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https://trac-hacks.org/ticket/63 | Opened 11 years ago
Closed 10 years ago
# support htpasswd with Windows and Python 2.3
Reported by: Owned by: sid|at|seegrid.com Matt Good high AccountManagerPlugin normal Matt Good 0.10
Change password fails on Windows if running Python 2.3:
Traceback (most recent call last):
File "C:\Python23\Lib\site-packages\trac\web\modpython_frontend.py", line 205, in handler
dispatch_request(mpr.path_info, mpr, env)
File "C:\Python23\Lib\site-packages\trac\web\main.py", line 139, in dispatch_request
dispatcher.dispatch(req)
File "C:\Python23\Lib\site-packages\trac\web\main.py", line 107, in dispatch
resp = chosen_handler.process_request(req)
File "build\bdist.win32\egg\acct_mgr\web_ui.py", line 48, in process_request
File "build\bdist.win32\egg\acct_mgr\web_ui.py", line 64, in _do_change_password
File "build\bdist.win32\egg\acct_mgr\htfile.py", line 49, in set_password
File "build\bdist.win32\egg\acct_mgr\htfile.py", line 102, in userline
File "build\bdist.win32\egg\acct_mgr\htfile.py", line 75, in salt
File "build\bdist.win32\egg\acct_mgr\htfile.py", line 30, in urandom
IOError: [Errno 2] No such file or directory: '/dev/urandom'
I saw another site hinted at using windrandom.pyd file for Windows for Python 2.3 (although it is deprecated in 2.4 in favor of os.urandom).
### comment:1 Changed 11 years ago by Matt Good
Status: new → assigned Change password fails on Windows with Python 2.3 → support htpasswd with Windows and Python 2.3 defect → enhancement
Ok, I didn't find a reasonable way to generate cryptographically sound random data on Windows with Python 2.3, but that winrandom module may work. Can you try it with the following patch:
• ## acct_mgr/htfile.py
try: from os import urandom except ImportError: def urandom(n): return open('/dev/urandom').read(n) try: from winrandom import winrandom as urandom except ImportError: def urandom(n): return open('/dev/urandom').read(n) class AbstractPasswordFileStore(Component):
Also, note that htdigest does not require random data so it could be used instead of htpasswd.
### comment:2 Changed 11 years ago by Alec Thomas
Description: modified (diff)
### comment:3 Changed 11 years ago by Peter Bruin
I had the same problem on Windows. In the end I got rid of the random functions and just added the htpasswd.exe to the path and use that to create a new password. Also had the problem that when changing a password the entry appeared twice in the file. I think this is because there was no check on written=True
Index: htfile.py
===================================================================
--- htfile.py (revision 359)
+++ htfile.py (working copy)
@@ -21,15 +21,7 @@
-# os.urandom was added in Python 2.4
-# try to fall back on reading from /dev/urandom on older Python versions
-try:
- from os import urandom
-except ImportError:
- def urandom(n):
-
-
+
"""Base class for managing password files such as Apache's htpasswd and
htdigest formats.
@@ -81,7 +73,7 @@
written = True
else:
print line,
- if userline:
+ if userline and not written:
f = open(filename, 'a')
try:
print >>f, userline
@@ -101,6 +93,7 @@
"""Manages user accounts stored in Apache's htpasswd format.
+ We actaully use the httpasswd.exe and placed it into the c:\windows dir
To use this implementation add the following configuration section to trac.ini
{{{
@@ -119,7 +112,13 @@
return user + ':'
- return self.prefix(user) + md5crypt(password, salt(), '$apr1$')
+ line = 'htpasswd -nb ' + user + ' ' + password
+ cmd = os.popen(line)
+ result = cmd.close() # This is the return code of the program!
+ for line2 in list:
+ return line2.rstrip( "\r\n" )
if not suffix.startswith('$apr1$'):
}}}
Some more functions could be removed but this worked for me and I wanted to change as little as possible because of future merges
### comment:4 Changed 11 years ago by Peter Bruin
I added this patch in my previous comment but it didn't come through:
Index: htfile.py
===================================================================
--- htfile.py (revision 359)
+++ htfile.py (working copy)
@@ -21,15 +21,7 @@
-# os.urandom was added in Python 2.4
-# try to fall back on reading from /dev/urandom on older Python versions
-try:
- from os import urandom
-except ImportError:
- def urandom(n):
-
-
+
"""Base class for managing password files such as Apache's htpasswd and
htdigest formats.
@@ -81,7 +73,7 @@
written = True
else:
print line,
- if userline:
+ if userline and not written:
f = open(filename, 'a')
try:
print >>f, userline
@@ -119,7 +112,13 @@
return user + ':'
- return self.prefix(user) + md5crypt(password, salt(), '$apr1$')
+ line = 'htpasswd -nb ' + user + ' ' + password
+ cmd = os.popen(line)
+ result = cmd.close() # This is the return code of the program!
+ for line2 in list:
+ return line2.rstrip( "\r\n" )
if not suffix.startswith('$apr1$'):
### comment:5 Changed 11 years ago by Gerry <ggl@…>
I tried your fix for htfile.py, since I run as well Python2.3 on Windows. Didn't get it running. It looks like that it was trying to write to the password file, but there is no entry even though the date of the file changed. Where did you set the path for htpasswd.exe?
### comment:6 Changed 11 years ago by chogeha
Cc: Peter Briun added; anonymous removed normal → high → 0.10 enhancement → defect
I tried Peter Briun patch to my trac, and it can work for python23 on window.
But there was a problem below.
When I create a new account and password in first,it can work and login success.
But when I create another new account or change the first account of password,
it will display an error.
Is this problem have any way to solve or it was improving now? like below
Python Traceback
Traceback (most recent call last):
File "C:\Python23\trac\web\main.py", line 299, in dispatch_request
dispatcher.dispatch(req)
File "C:\Python23\trac\web\main.py", line 189, in dispatch
resp = chosen_handler.process_request(req)
File "build\bdist.win32\egg\acct_mgr\web_ui.py", line 53, in process_request
File "build\bdist.win32\egg\acct_mgr\web_ui.py", line 72, in _do_delete
File "build\bdist.win32\egg\acct_mgr\api.py", line 97, in delete_user
File "build\bdist.win32\egg\acct_mgr\htfile.py", line 47, in delete_user
File "build\bdist.win32\egg\acct_mgr\htfile.py", line 71, in _update_file
File "C:\Python23\Lib\fileinput.py", line 231, in next
File "C:\Python23\Lib\fileinput.py", line 300, in readline
os.rename(self._filename, self._backupfilename)
OSError: [Errno 2] No such file or directory
Best Regards
### comment:7 Changed 11 years ago by Mike
Cc: Matt Good added; Peter Briun removed
I'm having trouble implementing the first solution using the winrandom.py. Where do I find that file in the Python23 dist, or a download somewhere?
### comment:8 Changed 11 years ago by Sam Bloomquist
Here is an "old school" way of fixing this issue if you can't get winrandom to work, as I couldn't.
try:
from os import urandom
except ImportError:
import random
def urandom(n):
L = [chr(random.randrange(0, 256)) for i in range(n)]
return "".join(L)
### comment:9 Changed 11 years ago by Peter Bruin
I tried the old school fix but got an error that random was not found. So in the end I went back to try and fix my previous working patch. It turned out that when the main line of trac went unicode the python library caused an error as it can not handle it. So I used the fix from [705] as fixed by mgood.
Index: htfile.py
===================================================================
--- htfile.py (revision 867)
+++ htfile.py (working copy)
@@ -21,15 +21,7 @@
-# os.urandom was added in Python 2.4
-# try to fall back on reading from /dev/urandom on older Python versions
-try:
- from os import urandom
-except ImportError:
- def urandom(n):
-
-
+
"""Base class for managing password files such as Apache's htpasswd and
htdigest formats.
@@ -74,14 +66,14 @@
filename = self._get_filename()
written = False
if os.path.exists(filename):
- for line in fileinput.input(filename, inplace=True):
+ for line in fileinput.input(str(filename), inplace=True):
if line.startswith(prefix):
if not written and userline:
print userline
written = True
else:
print line,
- if userline:
+ if userline and not written:
f = open(filename, 'a')
try:
print >>f, userline
@@ -101,6 +93,7 @@
"""Manages user accounts stored in Apache's htpasswd format.
+ We actaully use the httpasswd.exe and placed it into the c:\windows dir
To use this implementation add the following configuration section to trac.ini
{{{
@@ -119,7 +112,13 @@
return user + ':'
- return self.prefix(user) + md5crypt(password, salt(), '$apr1$')
+ line = 'htpasswd -nb ' + user + ' ' + password
+ cmd = os.popen(line)
+ result = cmd.close() # This is the return code of the program!
+ for line2 in list:
+ return line2.rstrip( "\r\n" )
+ else: return 'dummy:'+line
if not suffix.startswith('$apr1$'):
}}}
Gerry asked about the path for htpasswd.exe. I blundly placed htpasswd.exe in c:\windows :)
### comment:10 Changed 11 years ago by Matt Good
Type: defect → enhancement
Well, I don't want to make the htpasswd program a requirement for this plugin. I had also been avoiding the random module since those methods don't incorporate sufficient entropy for most cryptographic purposes. However, giving it some more thought, they should be suitable for generating the salt values since the security of the hash isn't really dependent on the salt, it just needed to prevent dictionary attacks. So, I'll incorporate something similar to the "old school" method.
### comment:11 Changed 11 years ago by Gerry <ggl@…>
The "old school" method worked for me. Thanks!
### comment:12 Changed 10 years ago by Matt Good
Resolution: → fixed assigned → closed
(In [1518]) provide a more cross-platform compatible fallback if os.urandom is not available (fixes #63)
### comment:13 Changed 10 years ago by Matt Good
#793 has been marked as a duplicate.
### Modify Ticket
Action
as closed The owner will remain Matt Good.
The resolution will be deleted. Next status will be 'reopened'. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.23990410566329956, "perplexity": 16212.832552722903}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501170404.1/warc/CC-MAIN-20170219104610-00428-ip-10-171-10-108.ec2.internal.warc.gz"} |
https://www.speedsolving.com/forum/threads/square-1-parity-algs.9512/ | # Square-1 Parity Algs
Discussion in 'General Speedcubing Discussion' started by blade740, Feb 13, 2009.
853
3
May 29, 2006
WCA:
2007NELS01
I'm really just posting this so that I can link to it instead of emailing the algs to everyone.
O: opposite
N: no swap
AA: /(-3,0)/(-3,0)/(-5,0)/(-2,0)/(4,0)/(-4,0)/(-2,0)/(5,0)/(-3,0)/ (matching bars at UR and DL)
AN: /(3,3)/(-1,0)/(2,0)/(-4,0)/(4,0)/(2,0)/(1,0)/(-3,-3)/ (matching bar at UR)
AO: /(3,3)/(-1,0)/(2,0)/(-4,0)/(4,0)/(2,0)/(-5,0)/(-3,-3)/ (matching bar at UL)
NA: /(-3,-3)/(0,-5)/(-4,-2)/(-4,0)/(-4,0)/(2,-4)/(5,0)/(-3,-3)/ (matching bar at DR)
OA: /(-3,-3)/(0,-5)/(-4,-2)/(-4,0)/(-4,0)/(2,-4)/(-1,0)/(-3,-3)/ (matching bar at DL)
OO: /(3,3)/(1,0)/(4,-2)/(2,-4)/(0,-4)/(3,3)/(3,0)/(3,3)/
ON: /(3,3)/(-1,0)/(-4,2)/(-2,4)/(0,1)/(3,3)/
NO: /(3,3)/(-1,0)/-4,2)/(-2,4))/(0,-5)/(3,3)/
Basically, I recognize parity and corner permutation at the same time. If there is no parity, I do a standard corner permutation alg and continue with a normal vandenbergh solution. If there IS parity, I do the parity alg that corresponds with the corner permutation and then continue with a normal vandenbergh solution. Basically, this means that by learning a few extra CP algs, I can save myself from having to learn half of the EP algs (and the worse half, at that).
Algs generated with Jaap's wonderful sq1optim program.
Oh, bonus: the AA alg is 2gen, and was half of the secret to solving the bandaged square-1.
Last edited: Sep 6, 2009
MooseCuber likes this.
2. ### Robert-YSuper ModeratorStaff Member
3,287
79
Jan 21, 2009
England
WCA:
2009YAUR01
Robert271291
Although I don't solve square-1s, let me be the first to say thanks as no-one has bothered so far .
Last edited: Sep 6, 2009
3. ### HakanMember
79
0
Apr 21, 2008
Rotterdam
WCA:
2008DENI01
Hakan625
Thank you very much.
I don't know any algs for Square-1, except for the regular parity-alg. This is now on my to-learn-list
5. ### byuMember
Dec 18, 2008
California
WCA:
2009YUBR01
bldmaster
I'm going to have to actually use a square-1 to figure out these. I ordered mine off PuzzleProz a few days ago, and I'm still waiting for it to come. Do I need to memorize all of these to solve the Square-1?
6. ### DavidWonerThe Punchmaster
May 7, 2008
Kansas City, MO, USA
WCA:
2008WONE01
vault312
No, you only need one parity alg.
7. ### VigMember
13
0
Feb 16, 2009
Wow this is great insight thanks a bunch!
8. ### Sebastian-1Member
33
0
Mar 30, 2009
Santiago, Chile
WCA:
2009CAST02
555pin0c
I don't understand how this works. I mean, first alg changes parity on D but not on U.
9. ### Jokerman5656Catch Me If You Can
575
4
Mar 15, 2009
Minnesota
WCA:
2009BRAI01
jokerman5656
the first letter stands for the top layer and the second for the bottom, at least i think thats how it works. time to experiment.
10. ### JasonMember
129
0
Oct 2, 2007
WCA:
2008GYAN01
I love a bit of square-1 action, and this seems really interesting although I don't quite understand the notation. When referring to Opposite, Adjacent, No Swap, what does it mean? And what does "matching bars" mean? Is a bar a solid colour of 2 corners and an edge aligned on a side? Are matching bars of the same colour?
This method has got me really interested in square-1 again, any help would be great
853
3
May 29, 2006
WCA:
2007NELS01
Recognition for this method is essentially twofold (though you can do both together with practice) First, determine whether or not you have parity. Then, you recognize a corner permutation case (essentially an ortega/guimond PBL case) A is an adjacent swap (like a J perm) O is an opposite corner swap (like a Y perm) N is no swap (like a U perm). Matching bar refers to the 2 corners that are paired up on an adj swap.
12. ### JasonMember
129
0
Oct 2, 2007
WCA:
2008GYAN01
Sweet, thank you very much Blade. I think I'm going to have a lot of fun this evening
853
3
May 29, 2006
WCA:
2007NELS01
Be safe. Don't forget to wear your helmet
853
3
May 29, 2006
WCA:
2007NELS01
Bump. I updated a few of the algorithms in the original post (namely AO, AN, NO, ON) Thanks to dan and dene for those algs. As a byproduct of generating algs with a solver that can't ignore pieces, I have large lists of algorithms for every case (directly output from jaap's solver) hosted here: http://dl.getdropbox.com/u/1186263/cpparity.rar
They're just text files, open them with notepad or whatever. If you find any algs that are more fingertrick-friendly than the ones I have posted here, let me know. I didn't really try very hard when I picked the original algs, so not all of them are that great.
15. ### deepSubDiverMember
161
0
Jun 17, 2009
Germany
Sorry for this bump.
I have problems detecting whether I have parity or not. I usually try to visualize the permutations I get but it fails when it comes to O-perms (which seem to have the correct order of the edges in their respective layer but actually are parity cases). How do you go around that?
16. ### ForteMember
Jul 12, 2009
Waterloo, Ontario
WCA:
2009SHIN02
Do you do lots of 3x3? If you have four edges wrong and it's not a Z or H perm, then it's an O or W perm (W perm has some opposite edges)
17. ### hawkmp4Member
May 17, 2008
I don't know if this is really effective at speed (I'm not fast at sq1 at all) but I recognise the permutation case like a 3x3 case. If the perm on top is a 3x3 perm and the one on bottom is not (or vice versa) then I know I have parity. If both top and bottom have 3x3 perms or neither top nor bottom have 3x3 perms I know I don't have parity.
18. ### ForteMember
Jul 12, 2009
Waterloo, Ontario
WCA:
2009SHIN02
That's like, the only way to do it
May 13, 2007
Denver, CO
WCA:
2007COHE01
masterofthebass
I do that in a different way than I do on 3x3 though. I usually do it by looking at blocks. For example, if there is a CEC block, I know that there cannot be another block (except for a j perm) for it not to have parity. On the same note, if there are 2 adj EC blocks, then unless there its a Jperm or Nperm (easy to detect) it has parity. Tricks like this really help me since you don't actually have to see the PLL (although I end up knowing what they are). | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8123743534088135, "perplexity": 2982.8599655246962}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676591140.45/warc/CC-MAIN-20180719144851-20180719164851-00195.warc.gz"} |
http://mathhelpforum.com/number-theory/40307-lattice-problem.html | ## Lattice Problem
In some quadratic field, find a lattice M such that N(M)=1(norm of the lattice is 1) but M is not equal to the set of integers of the lattice.
I know that if we have an integral lattice, N(M)=1 implies M = O_m where O_m is set of integers of the lattice. So we should find a lattice which is not integral. But how? Can you find such a lattice? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9589745998382568, "perplexity": 393.44096827724013}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-26/segments/1529267867579.80/warc/CC-MAIN-20180625072642-20180625092642-00219.warc.gz"} |
https://knowledgebase.equilibrium.io/research/research-1/the-bancor-protocol-the-tip-of-the-iceberg | # The Bancor Protocol: the Tip of the Iceberg
Equilibrium recently announced the launch of its new R&D division, Equilibrium Labs, aiming to develop new price-pegging algorithms and structures that will bring enhanced liquidity to the decentralized finance market.
It was a logical choice to start our research with the Bancor protocol and Daniel Larimer’s pegging algorithm.
The Bancor protocol is a simple and elegant solution that lets tokens be converted to other types of tokens. The price of conversion is solely determined by the ratio of the transparent reserves of each token. It’s an ambitious initiative named after Keynes famous proposal to create a “_c_urrency union” that would “generalize the essential principle of banking as it is exhibited within any closed system. This system is the necessary equality of credits and debits, of assets and liabilities.”
Extensive research has already formalized and simulated Keynes’s model. Looking at Valdecantos and Zezza’s work, we can immediately weigh the potential complexity of modelling a real-world economy with four “countries:” the United States, Europe, China, and the rest of the world.
In the real-world economy, a country’s inhabitants work, produce, export, import, and consume. Agents have risks and preferences. Naturally, prices will reflect these risks and preferences. By contrast, the price of a Bancor Relay **is completely determined by the amount of available tokens held in reserve (eg. the Bancor “connectors”). The concept of risk is missing, and with good reason.
The Bancor protocol is a fundamental concept that should be considered the backbone of a central bank. And like a central bank, the Bancor protocol structure is not profit-oriented.
From a stablecoin perspective, Bancor can be used to synthesize the most trivial model of a central bank with a pegged currency policy.
# Daniel Larimer’s pegging algorithm
For instance, Larimer describes a pegging algorithm based on the Bancor protocol in a recent article. The new Market Making token (MMS) introduced there is a wrapper around a Bancor Relay token with two connectors — one for the collateral asset (EOS, for example) and the second one for the USD-pegged asset. Pegging the Bancor price to the market price consists of rebalancing the connectors’ quantities to keep their market value equal, or within a tight range of ± 2%. The market value of each connector is based on a trusted price feed or a 24-hour median. Rebalancing the connectors’ quantities happens by moving collateral in and out of an excess collateral reserve.
The perfectly named “pegging algorithm” could be perceived as the first simple representation of a country choosing to peg its currency to that of another. The country would use its currency reserves to intervene in the market if it became necessary to enforce the peg. Similarly, the “pegging algorithm” can use the excess collateral to buy a depreciated USD-pegged token.
However the “pegging algorithm” is not an MM algorithm. Larimer points out that those willing to hold MMS tokens are those willing to be slightly leverage-long in a collateral asset (such as EOS). __They are the ones willing to hold inventory risk. They essentially accept this risk for free or little benefit.
So how would the structure compensate for inventory risk?
Let us resume the rational market maker’s (MM) objectives:
• A rational MM would seek to maximize profits under inventory risk constraints. The market maker should be rewarded for holding this risk.
• A market maker will also be concerned with running out of inventory, in which case they wouldn’t be able to quote both a bid and ask. They prefer to hold a mix.
Once again, the Bancor Protocol is a decentralized exchange facility where anyone can show a price that’s determined and fully backed by transparent quantities. For a participant, the price ratio has to reflect a ratio of tangible reserves, but the ratio of tangible reserves could reflect the participant’s risks and preferences. The ratio of tangible reserves can be the output of an algorithm (like the “pegging algorithm”) that accounts for inventory risk.
In other words, the price produced by Bancor is only the tip of the iceberg. It could be the price that an MM decides to publish. We know it’s not a fake price because it’s backed by actual quantities. What we don’t know is how the quantities will be adjusted: we don’t know the MM actual risks (like the MM’s true inventory) or preferences (like the MM’s aversion to risk). In these conditions, anyone can try to reverse engineer the MM’s risks and preferences. Anyone can try to build a better model to arbitrage the MM: “the (stablecoin) shorts” would start to compete.
Competition between rational MMs might be what is needed to effectively attract liquidity. Alternatively, can a community reach a consensus on a more advanced MM model. Can a community vote to set the parameters of this advanced MM model on a regular basis?
# The Bancor Framework... With Custom Preferences?
Let’s illustrate the above with a simple model that is widely used in economics theory.
Given the sole dependency of the Bancor relay price on the connectors’ quantities, the model reminds me of one that is at the heart of some of the most advanced economic models: the Dixit-Stiglitz model.
The Dixit-Stiglitz model follows this simple hypothesis: “a consumer who is indifferent between the quantities (1,0) and (0,1) of two commodities prefers to hold a mix.” In other words, agents love variety.
In his 40-year review since the Dixit-Stiglitz model, Stiglitz states: **“If the returns to shares of firms” (aka tokens) “are not perfectly correlated, then each is an imperfect substitute for the other. Individuals will want to hold all shares in their portfolio — just as in the Dixit–Stiglitz model, individuals want to buy all commodities” (aka tokens) ”that are produced.”
Bancor is a limit case of the Dixit-Stiglitz utility. Because inventories can never deplete, there will always be a mix. For two relays with similar connector positions, Bancor will always show the same consensus price, regardless of preferences. If the connector quantity of an asset drops, the Bancor price for the asset will soar. But what if the MM wants to take more risk and sell more of the asset, despite the low inventory? Dixit-Stiglitz lets the experienced market-makers show a more aggressive offer, should they believe that the price will revert to its mean. It gives market-makers more freedom.
The table below shows how the alternative Dixit-Stiglitz price would evolve compared to the Bancor price.
# A Generalized Bancor Protocol Wrapper
Dan Larimer’s algorithm lets the Bancor Relay show a price that is within a spread, close to a feed price: the 24-hour median price. In fact, the feed price can be anything. If we rebalance the Bancor connectors’ quantities such that their ratio equates the feed price (FP): qEOSDTBancorqBancorEOSDT / qEOSBancorqBancorEOS = 1 / FP, then the Bancor Relay formula will force the Bancor price qBancorEOS/EOSDTqEOS/EOSDTBancor to revert to FP.
For an agent with specific preferences, FP should be the price that maximizes the Dixit-Stiglitz Utility.
For a Market Maker, FP should be within market bid-ask spread, closer to the bid if there is a buying interest, and closer to the ask in case there is a selling interest. The choice of feed price is the critical leeway we need to make the MMS algorithm a true market making algo.
FP could factor in a market maker’s preferences and risk aversion. We can let the market maker algorithm modify the connector quantities to target any set price.
# A Simple Wrapper: The Dixit-Stiglitz Protocol
For an EOS-EOSDT Relay, an agent with preferences holds a total quantity QEOSQEOS of EOS tokens and a total quantity QEOSDTQEOSDT of EOSDT tokens.
If they prefer to quote a more aggressive ask if the price goes up, or a more aggressive bid if the price goes down. The agent can set:
$FP = (Q_{EOS}/Q_{EOSDT})^{1−ρ}$
Then $q^{Bancor}_{EOS/EOSDT}$ will be reset towards the optimal level that maximizes the agent’s Dixit-Stiglitz utility.
# An Advanced Wrapper: The Market-Maker Protocol
Unlike a nonprofit central bank, the MMs objective is to maximize the book value of their MMS tokens. The astute MMs can design an algorithm that target the equilibrium price that maximizes the expected book value under their inventory risk constraints over a specific investment horizon.
This is the next step to build serious incentive for anyone to buy (or create) market-making tokens, and trust that their invested value will be maximized.
In the context of Equilibrium Labs, there is room for research into an extended role for the NUT token holders. NUT holders could interact with or even manage such an EOS/EOSDT wrapper for EOS collateral liquidations. The transfer of more EOS to a Bancor Relay would intuitively drive the EOS/EOSDT price down to account for the keepers rebate.
Stay tuned!
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https://www.science.gov/topicpages/0-9/10-3+omega+cm.html | #### Sample records for 10-3 omega cm
1. 4H-SiC Power Bipolar Junction Transistor with a Very Low Specific On-resistance of 2.9 mOmega.cm2
DTIC Science & Technology
2006-04-12
pp1381-1382, 2004. [2] C.-F. Huang and J. A. Cooper, Jr., “High current gain 4H-SiC NPN Bipolar Junction Transistors ,” IEEE Electron Device Lett...4H-SiC Power Bipolar Junction Transistor with a Very Low Specific On-resistance of 2.9 mΩ.cm2 Jianhui Zhang, member, IEEE, Petre Alexandrov...specific on-resistance (Rsp,on) of power 4H-SiC bipolar junction transistors (BJT). A 4H-SiC BJT based on a 12 um drift-layer shows a record low
2. B Meson Decays to mega K*, omega rho, omega omega, omega phi, and omega f0
SciTech Connect
Aubert, B.; Barate, R.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G.S.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Karlsruhe U., EKP /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /Pisa U. /INFN, Pisa /Prairie View A-M /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Stony Brook /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison /Yale U. /Clermont-Ferrand U. /Basilicata U., Potenza
2006-07-28
The authors describe searches for B meson decays to the charmless vector-vector final states {omega}K*, {omega}p, {omega}{omega}, and {omega}{phi} with 233 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation at {radical}s = 10.58 GeV. They also search for the vector-scalar B decay to {omega}f{sub 0}.
3. Omega Electroproduction
SciTech Connect
Unwuchola, A. D.; Connell, Simon H.; Aurousseau, M.; Dalton, Mark M.
2013-08-01
The differential cross section for p(e, e'ω)p has been studied at Q{sup 2} ~ 5.5 (GeV/c)2. Here Q{sup 2} represents the four momentum squared of the virtual photon in the excitation of baryonic resonances by an electron projectile. In order to extract the ω-meson differential cross section from the JLAB data, the data was compared to a full Monte Carlo simulation of the detector based on events generated for omega production in a way that the production cross section was varied to achieve a match to the data. The bin selected for this procedure takes into account the measure of robustness of the stripping of the ω peak from the multi-pion background as well as the statistics in the measured data and the Monte Carlo simulation of the signal and background physics. An error estimation technique for the cross section was based on determining the dependence of the extracted cross section parameters on the experimental set-up (including parameters for the spectrometer, target beam geometeries and performance). We compare our results with a Regge-based model for hadronic content in the t-channel exchange of a photon in Q{sup 2} region of overlap. There is an extension of this data into a completely new region, which is the highest yet measured.
4. Omega documentation
SciTech Connect
Howerton, R.J.; Dye, R.E.; Giles, P.C.; Kimlinger, J.R.; Perkins, S.T.; Plechaty, E.F.
1983-08-01
OMEGA is a CRAY I computer program that controls nine codes used by LLNL Physical Data Group for: 1) updating the libraries of evaluated data maintained by the group (UPDATE); 2) calculating average values of energy deposited in secondary particles and residual nuclei (ENDEP); 3) checking the libraries for internal consistency, especially for energy conservation (GAMCHK); 4) producing listings, indexes and plots of the library data (UTILITY); 5) producing calculational constants such as group averaged cross sections and transfer matrices for diffusion and Sn transport codes (CLYDE); 6) producing and updating standard files of the calculational constants used by LLNL Sn and diffusion transport codes (NDFL); 7) producing calculational constants for Monte Carlo transport codes that use group-averaged cross sections and continuous energy for particles (CTART); 8) producing and updating standard files used by the LLNL Monte Carlo transport codes (TRTL); and 9) producing standard files used by the LANL pointwise Monte Carlo transport code MCNP (MCPOINT). The first four of these functions and codes deal with the libraries of evaluated data and the last five with various aspects of producing calculational constants for use by transport codes. In 1970 a series, called PD memos, of internal and informal memoranda was begun. These were intended to be circulated among the group for comment and then to provide documentation for later reference whenever questions arose about the subject matter of the memos. They have served this purpose and now will be drawn upon as source material for this more comprehensive report that deals with most of the matters covered in those memos.
5. Omega-3 fatty acids
PubMed Central
Schwalfenberg, Gerry
2006-01-01
OBJECTIVE To examine evidence for the role of omega-3 fatty acids in cardiovascular disease. QUALITY OF EVIDENCE PubMed was searched for articles on the role of omega-3 fatty acids in cardiovascular disease. Level I and II evidence indicates that omega-3 fatty acids are beneficial in improving cardiovascular outcomes. MAIN MESSAGE Dietary intake of omega-3 fatty acids has declined by 80% during the last 100 years, while intake of omega-6 fatty acids has greatly increased. Omega-3 fatty acids are cardioprotective mainly due to beneficial effects on arrhythmias, atherosclerosis, inflammation, and thrombosis. There is also evidence that they improve endothelial function, lower blood pressure, and significantly lower triglycerides. CONCLUSION There is good evidence in the literature that increasing intake of omega-3 fatty acids improves cardiac outcomes. Physicians need to integrate dietary recommendations for consumption of omega-3 fatty acids into their usual cardiovascular care. PMID:16812965
6. Omega-6 Fatty Acids
MedlinePlus
Omega-6 fatty acids are types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean oils. Other types of omega-6 fatty acids are found in black currant seed, borage seed, ...
7. Omega-3 fatty acids (image)
MedlinePlus
Omega-3 fatty acids are a form of polyunsaturated fat that the body derives from food. Omega-3s (and omega-6s) are known as essential fatty acids (EFAs) because they are important for good health. ...
8. Omega-3 Fatty Acids
MedlinePlus
Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount of triglycerides (a fat-like ... people with very high triglycerides. Omega-3 fatty acids are in a class of medications called antilipemic ...
9. Progress in Cryogenic Target Implosions on OMEGA
McCrory, R. L.; Meyerhofer, D. D.; Betti, R.; Boehly, T. R.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Glebov, V. Yu; Goncharov, V. N.; Harding, D. R.; Hu, S. X.; Knauer, J. P.; Marshall, F. J.; McKenty, P. W.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Seka, W.; Short, R. W.; Shvarts, D.; Skupsky, S.; Smalyuk, V. A.; Soures, J. M.; Stoeckl, C.; Theobald, W.; Yaakobi, B.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.; Séguin, F. H.; Casey, D. T.
2016-10-01
Cryogenic deuterium-tritium targets are imploded on the OMEGA Laser System in a direct-drive configuration. Areal densities of approximately 200 mg/cm2 have been measured with implosion velocities of 3 × 107 cm/s. These implosions are used to study the dynamics of cryogenic target compression and to develop areal-density diagnostics that will be used as part of the ignition campaign on the National Ignition Facility.
10. 24 CFR 10.3 - Applicability.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Applicability. 10.3 Section 10.3 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development RULEMAKING: POLICY AND PROCEDURES General § 10.3 Applicability. (a) This part prescribes general...
11. 1 CFR 10.3 - Format.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 1 General Provisions 1 2010-01-01 2010-01-01 false Format. 10.3 Section 10.3 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER SPECIAL EDITIONS OF THE FEDERAL REGISTER PRESIDENTIAL PAPERS Regular Publication § 10.3 Format. The Daily Compilation of Presidential Documents is published online...
12. 1 CFR 10.3 - Format.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 1 General Provisions 1 2011-01-01 2011-01-01 false Format. 10.3 Section 10.3 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER SPECIAL EDITIONS OF THE FEDERAL REGISTER PRESIDENTIAL PAPERS Regular Publication § 10.3 Format. The Daily Compilation of Presidential Documents is published online...
13. 10 CFR 10.3 - [Reserved
Code of Federal Regulations, 2014 CFR
2014-01-01
... 10 Energy 1 2014-01-01 2014-01-01 false 10.3 Section 10.3 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED DATA OR NATIONAL SECURITY INFORMATION OR AN EMPLOYMENT CLEARANCE General Provisions § 10.3...
14. 10 CFR 10.3 - [Reserved
Code of Federal Regulations, 2010 CFR
2010-01-01
... 10 Energy 1 2010-01-01 2010-01-01 false 10.3 Section 10.3 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED DATA OR NATIONAL SECURITY INFORMATION OR AN EMPLOYMENT CLEARANCE General Provisions § 10.3...
15. 10 CFR 10.3 - [Reserved
Code of Federal Regulations, 2012 CFR
2012-01-01
... 10 Energy 1 2012-01-01 2012-01-01 false 10.3 Section 10.3 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED DATA OR NATIONAL SECURITY INFORMATION OR AN EMPLOYMENT CLEARANCE General Provisions § 10.3...
16. 10 CFR 10.3 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-01-01
... 10 Energy 1 2011-01-01 2011-01-01 false 10.3 Section 10.3 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED DATA OR NATIONAL SECURITY INFORMATION OR AN EMPLOYMENT CLEARANCE General Provisions § 10.3...
17. 10 CFR 10.3 - [Reserved
Code of Federal Regulations, 2013 CFR
2013-01-01
... 10 Energy 1 2013-01-01 2013-01-01 false 10.3 Section 10.3 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED DATA OR NATIONAL SECURITY INFORMATION OR AN EMPLOYMENT CLEARANCE General Provisions § 10.3...
18. B meson decays to {omega}K*, {omega}{rho}, {omega}{omega}, {omega}{phi}, and {omega}f{sub 0}
SciTech Connect
Aubert, B.; Barate, R.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.
2006-09-01
We describe searches for B meson decays to the charmless vector-vector final states {omega}K*, {omega}{rho}, {omega}{omega}, and {omega}{phi} with 233x10{sup 6} BB pairs produced in e{sup +}e{sup -} BB annihilation at {radical}(s)=10.58 GeV. We also search for the vector-scalar B decay to {omega}f{sub 0}. We measure the following branching fractions in units of 10{sup -6}: B(B{sup 0}{yields}{omega}K*{sup 0})=2.4{+-}1.1{+-}0.7 (<4.2), B(B{sup +}{yields}{omega}K*{sup +})=0.6{sub -1.2-0.9}{sup +1.4+1.1} (<3.4), B(B{sup 0}{yields}{omega}{rho}{sup 0})=-0.6{+-}0.7{sub -0.3}{sup +0.8} (<1.5), B(B{sup +}{yields}{omega}{rho}{sup +})=10.6{+-}2.1{sub -1.0}{sup +1.6}, B(B{sup 0}{yields}{omega}{omega})=1.8{sub -0.9}{sup +1.3}{+-}0.4 (<4.0), B(B{sup 0}{yields}{omega}{phi})=0.1{+-}0.5{+-}0.1 (<1.2), and B(B{sup 0}{yields}{omega}f{sub 0})=0.9{+-}0.4{sub -0.1}{sup +0.2} (<1.5). In each case the first error quoted is statistical, the second systematic, and the upper limits are defined at the 90% confidence level. For B{sup +}{yields}{omega}{rho}{sup +} decays we also measure the longitudinal spin component f{sub L}=0.82{+-}0.11{+-}0.02 and the charge asymmetry A{sub CP}=0.04{+-}0.18{+-}0.02.
19. 42 CFR 10.3 - Definitions.
Code of Federal Regulations, 2013 CFR
2013-10-01
... contracts with purchasers, such as hospitals, nursing homes, and home health agencies, to aggregate... or employee of the Department of Health and Human Services to whom the authority involved has been... 42 Public Health 1 2013-10-01 2013-10-01 false Definitions. 10.3 Section 10.3 Public Health...
20. 21 CFR 10.3 - Definitions.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Definitions. 10.3 Section 10.3 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATIVE PRACTICES AND... 12, 13, 14, 15, 16, and 19: Act means the Federal Food, Drug, and Cosmetic Act unless...
1. 21 CFR 10.3 - Definitions.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Definitions. 10.3 Section 10.3 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATIVE PRACTICES AND... 12, 13, 14, 15, 16, and 19: Act means the Federal Food, Drug, and Cosmetic Act unless...
2. [Omega-3 and health].
PubMed
Herbaut, C
2006-09-01
N-3 PUFA (omega-3), and the n-6 PUFA (omega-6) are essential fatty acids. They must be absorbed by alimentation and play a very important role in the coagulation (inhibition of platelets aggregation) and in the inflammatory reaction (anti-inflammatory effects). Their effects have been studied in different sicknesses. In cardiovascular diseases, particularly in coronary diseases, studies demonstrated a decreased mortality in populations who eat an omega-3 rich diet or who take an omega-3 supplement. Among others, sudden death after myocardial infarction is decreased. In inflammatory diseases an effect seem to be found in some studies. In rheumatoid arthritis a decrease of different biological markers of inflammation and in some case a clinical improvement has been noticed. It may be the same in COPD. On the other hand, they seem not to give any protection against cancer in general. At this moment the recommendations for healthy people are to eat twice a week fat fish and to take omega-3 rich oils. For pathological cases, recommendations exist only for coronary disease: 1 g of fish oils : mixture of eicosapentaenoic and docosahexaenoic acids (EPA/DHA) should be given after a myocardial infarction.
3. From Alpha To Omega
Castellano, Doc
2002-05-01
Galileo, the Father of Modern Science put forth the first significant Modern Scientific Era/Philosophy. Best represented per: x' = x (+/-) vt. Locating/defining the dynamic x' per a fixed, Cartesian Coordinate, reference frame.----- Einstein, the popularized relativist, utilizing Lorentz's transformation Equations: x' = (x-vt)/squareroot [1 - (v squared/c squared)], c the velocity of light. Arbitrarily decreed that c must be the ultimate universal velocity. Thus, Reporters, the general Public, and Scientists consider/considered, Einstein's OPINION of our Universe, the 'Omega Concept'. ----- Castellano, since 1955, has PROVEN his "Castellano Transformation Equations": X' = (X - vt)/squareroot [ 1 - (v squared/c squared)]. Capital C = or greater than c; IS THE OMEGA CONCEPT. And his "MAPHICS" combining the Philosophy of Mathematics with the Philosophy of Physics is "THE OMEGA PHILOSOPHY". Sufficient PROOFS and details at: http://hometown.aol.com/phdco/myhomepage/index.html Thank you for your interest. My sincere appreciation for your attention and deserved acknowledgments.
4. From Alpha To Omega
Castellano, Doc
2002-08-01
Galileo, the Father of Modern Science, put forth the first significant Modern Scientific Era/Philosophy. Best represented per: x' = x (+/-) vt. Locating/defining the dynamic x' in an Euclidean, fixed frame Universe. Einstein, the popularized relativist, utilizing Lorentz's transformation equations: x' = (x - vt)/square root [ 1- (v squared/c squared)], c the velocity of light. Arbitrarily decreed that c must be the ultimate, universal velocity. Thus, Reporters, the general Public and Scientists consider/considered, Einstein's OPINION of our Universe, 'The Omega Concept'. Castellano, since 1954, has PROVEN the "C Transformation Equations": X' = (X - vt)/square root [ 1 - (v squared/C squared)], Capital C = or greater than c; IS THE OMEGA CONCEPT. And "MAPHICS", combining the Philosophy of Mathematics with the Philosophy of Physics is "THE OMEGA PHILOSOPHY". Sufficient PROOFS & details are at: http://hometown.aol.com/phdco/myhomepage/index/html ----- Thank you for your interest. My sincere appreciation for deserved acknowledgements.
5. High accuracy OMEGA timekeeping
NASA Technical Reports Server (NTRS)
Imbier, E. A.
1982-01-01
The Smithsonian Astrophysical Observatory (SAO) operates a worldwide satellite tracking network which uses a combination of OMEGA as a frequency reference, dual timing channels, and portable clock comparisons to maintain accurate epoch time. Propagational charts from the U.S. Coast Guard OMEGA monitor program minimize diurnal and seasonal effects. Daily phase value publications of the U.S. Naval Observatory provide corrections to the field collected timing data to produce an averaged time line comprised of straight line segments called a time history file (station clock minus UTC). Depending upon clock location, reduced time data accuracies of between two and eight microseconds are typical.
6. Improvements for Omega RF preamplifiers
NASA Technical Reports Server (NTRS)
Wright, L.
1976-01-01
An improved Omega navigation system preamplifier, which provides both ADF and Omega outputs from a single antenna input, is described. This preamp has tuneable bandpass filtering, zero phase shift at both output ports, adjustable gain at the Omega output, and it receives power via the coaxial cable to the receiver front-end.
7. The Omega Competition.
ERIC Educational Resources Information Center
Lanni, Robert P.
1978-01-01
Describes a game in which the symbol omega becomes equivalent to the word ohm, and is then modified or incorporated into a picture to represent a common word or phrase. Recommends the game as a way of humanizing the beginning course. (GA)
8. 32 CFR 10.3 - Applicability.
Code of Federal Regulations, 2013 CFR
2013-07-01
... Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE MILITARY COMMISSIONS MILITARY COMMISSION INSTRUCTIONS § 10.3 Applicability. This part, and, unless stated otherwise, all other Military Commission..., the Military Departments, the Chairman and Vice Chairman of the Joint Chiefs of Staff and the...
9. 36 CFR 10.3 - Application; requirements.
Code of Federal Regulations, 2011 CFR
2011-07-01
... post office address for Yellowstone National Park is Yellowstone Park, Wyoming, and for Wind Cave National Park is Hot Springs, South Dakota. (b) Applicants desiring animals which are to be held in....3 Section 10.3 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE...
10. 36 CFR 10.3 - Application; requirements.
Code of Federal Regulations, 2014 CFR
2014-07-01
... post office address for Yellowstone National Park is Yellowstone Park, Wyoming, and for Wind Cave National Park is Hot Springs, South Dakota. (b) Applicants desiring animals which are to be held in....3 Section 10.3 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE...
11. 36 CFR 10.3 - Application; requirements.
Code of Federal Regulations, 2013 CFR
2013-07-01
... post office address for Yellowstone National Park is Yellowstone Park, Wyoming, and for Wind Cave National Park is Hot Springs, South Dakota. (b) Applicants desiring animals which are to be held in....3 Section 10.3 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE...
12. 36 CFR 10.3 - Application; requirements.
Code of Federal Regulations, 2010 CFR
2010-07-01
... post office address for Yellowstone National Park is Yellowstone Park, Wyoming, and for Wind Cave National Park is Hot Springs, South Dakota. (b) Applicants desiring animals which are to be held in....3 Section 10.3 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE...
13. 36 CFR 10.3 - Application; requirements.
Code of Federal Regulations, 2012 CFR
2012-07-01
... post office address for Yellowstone National Park is Yellowstone Park, Wyoming, and for Wind Cave National Park is Hot Springs, South Dakota. (b) Applicants desiring animals which are to be held in....3 Section 10.3 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE...
14. Ubiquitous CM and DM
NASA Technical Reports Server (NTRS)
Crowley, Sandra L.
2000-01-01
Ubiquitous is a real word. I thank a former Total Quality Coach for my first exposure some years ago to its existence. My version of Webster's dictionary defines ubiquitous as "present, or seeming to be present, everywhere at the same time; omnipresent." While I believe that God is omnipresent, I have come to discover that CM and DM are present everywhere. Oh, yes; I define CM as Configuration Management and DM as either Data or Document Management. Ten years ago, I had my first introduction to the CM world. I had an opportunity to do CM for the Space Station effort at the NASA Lewis Research Center. I learned that CM was a discipline that had four areas of focus: identification, control, status accounting, and verification. I was certified as a CMIl graduate and was indoctrinated about clear, concise, and valid. Off I went into a world of entirely new experiences. I was exposed to change requests and change boards first hand. I also learned about implementation of changes, and then of technical and CM requirements.
15. Damper Spring For Omega Seal
NASA Technical Reports Server (NTRS)
Maclaughlin, Scott T.; Montgomery, Stuart K.
1993-01-01
Damper spring reduces deflections of omega-cross-section seal, reducing probability of failure and extending life of seal. Spring is split ring with U-shaped cross section. Placed inside omega seal and inserted with seal into seal cavity. As omega seal compressed into cavity, spring and seal make contact near convolution of seal, and spring becomes compressed also. During operation, when seal dynamically loaded, spring limits deflection of seal, reducing stress on seal.
NASA Technical Reports Server (NTRS)
Lilley, R. W.
1974-01-01
The development of a low cost Omega navigation receiver is discussed. Emphasis is placed on the completion and testing of a modular, multipurpose Omega receiver which utilizes a digital memory-aided, phase-locked loop to provide phase measurement data to a variety of applications interfaces. The functional units contained in the prototype device are described. The receiver is capable of receiving and storing phase measurements for up to eight Omega signals and computes two switch-selectable lines of position, displaying this navigation data in chart-recorded form.
17. Omega-3 fats: Good for your heart
MedlinePlus
... arteries - omega-3s; Coronary artery disease - omega-3s; Heart disease - omega-3s ... Omega-3s are good for your heart and blood vessels in several ways. They reduce triglycerides , a type of fat in your blood. They reduce the risk of an ...
18. Analysis of the vertices {Omega}{sub Q}*{Omega}{sub Q{phi}} and radiative decays {Omega}{sub Q}*{yields}{Omega}{sub Q{gamma}}
SciTech Connect
Wang Zhigang
2010-02-01
In this article, we study the vertices {Omega}{sub Q}*{Omega}{sub Q{phi}} with the light-cone QCD sum rules, then assume the vector meson dominance of the intermediate {phi}(1020), and calculate the radiative decays {Omega}{sub Q}*{yields}{Omega}{sub Q{gamma}}.
19. Omega-3 Fatty Acids during Pregnancy
MedlinePlus
OMEGA-3 FATTY ACIDS DURING PREGNANCY S HARE W ITH W OMEN OMEGA-3 FATTY ACIDS DURING PREGNANCY During pregnancy, your baby gets most ... eat and vitamins you take. Omega-3 fatty acids (omega-3s) are an important family of building ...
20. Short Zoom Into Omega Centauri
NASA Video Gallery
This is a zoom into a simulated model of the globular star cluster Omega Centauri. All the stars appear to be moving in random directions, like a swarm of bees. Astronomers used Hubble's exquisite ...
1. Characterization of omega-3 tablets.
PubMed
Vestland, Tina Lien; Jacobsen, Øyvind; Sande, Sverre Arne; Myrset, Astrid Hilde; Klaveness, Jo
2016-04-15
Omega-3 nutraceuticals are extensively used as health supplements worldwide. Various administration forms for delivery of omega-3 are available. However, the niche omega-3 tablets have so far remained unexplored. In this work tablets containing 25-40% (w/w) omega-3 oil as triglycerides or ethyl esters were prepared utilizing a direct compaction grade powder with β-cyclodextrin as encapsulating agent. It was found that powders with up to 35% (w/w) triglyceride oil and 30% (w/w) ethyl ester oil, respectively, can be directly compressed into tablets of excellent quality. Physical properties of omega-3 containing powders and tablets are described. The powder X-ray diffractograms of the powders and crushed tablets show evidence of the formation of new crystalline phases not present in β-cyclodextrin. In addition, (1)H NMR data suggest that the ethyl esters form inclusion complexes with β-cyclodextrin. Compaction of other, commercially available, omega-3 powders was performed as a comparison and deemed unsuccessful.
2. Omega, the final multiplier
Buckley, T. N.
2008-12-01
The application of optimisation theory to vegetation processes has rarely extended beyond the context of diurnal to intra-annual gas exchange of individual leaves and crowns. One reason is that the Lagrange multipliers in the leaf-scale solutions, which are marginal products for allocatable photosynthetic resource inputs (water and nitrogen), are mysterious in origin, and their numerical values are difficult to measure -- let alone to predict or interpret in concrete physiological or ecological terms. These difficulties disappear, however, when the optimisation paradigm itself is extended to encompass carbon allocation and growth at the lifespan scale. The trajectories of leaf (and canopy) level marginal products are then implicit in the trajectory of plant and stand structure predicted by optimal carbon allocation. Furthermore, because the input and product are the same resource -- carbon -- in the whole plant optimisation, the product in one time step defines the input constraint, and hence implicitly the marginal product for carbon, in the next time step. This effectively converts the problem from a constrained optimisation of a definite integral, in which the multipliers are undetermined, to an unconstrained maximisation of a state, in which the multipliers are all implicit. This talk will explore how the marginal products for photosynthetic inputs as well as the marginal product for carbon -- i.e., the 'final multiplier,' omega -- are predicted to vary over time and in relation to environmental change during tree growth.
3. Spatial profile reconstruction of individual componentsof the nonlinear susceptibility tensors {chi}-circumflex {sup (3)}(z, {omega}', {omega}' -{omega}, {omega}) and {chi}-circumflex {sup (3)}(z, 2{omega}{+-}{omega}', {+-}{omega}', {omega}, {omega}) of a one-dimensionally inhomogeneous medium
SciTech Connect
Golubkov, A A; Makarov, Vladimir A
2011-06-30
We have proved for the first time and proposed an algorithm of unique spatial profile reconstruction of the components {chi}-circumflex {sup (3)}{sub yyyy} of complex tensors {chi}-circumflex {sup (3)}(z, {omega}', {omega}', -{omega}, {omega}) and {chi}-circumflex {sup (3)}(z, 2{omega}{+-}{omega}', {+-}{omega}', {omega}, {omega}), describing four-photon interaction of light waves in a one-dimensionally inhomogeneous plate, whose medium has a symmetry plane m{sub y} that is perpendicular to its surface. For the media with an additional symmetry axis 2{sub z}, 4{sub z}, 6{sub z} or {infinity}{sub z} that is perpendicular to the plate surface, the proposed method can be used to reconstruct about one-fifth of all independent components of the above tensors. (nonlinear optical phenomena)
4. omega-Helices in proteins.
PubMed
Enkhbayar, Purevjav; Boldgiv, Bazartseren; Matsushima, Norio
2010-05-01
A modification of the alpha-helix, termed the omega-helix, has four residues in one turn of a helix. We searched the omega-helix in proteins by the HELFIT program which determines the helical parameters-pitch, residues per turn, radius, and handedness-and p = rmsd/(N - 1)(1/2) estimating helical regularity, where "rmsd" is the root mean square deviation from the best fit helix and "N" is helix length. A total of 1,496 regular alpha-helices 6-9 residues long with p < or = 0.10 A were identified from 866 protein chains. The statistical analysis provides a strong evidence that the frequency distribution of helices versus n indicates the bimodality of typical alpha-helix and omega-helix. Sixty-two right handed omega-helices identified (7.2% of proteins) show non-planarity of the peptide groups. There is amino acid preference of Asp and Cys. These observations and analyses insist that the omega-helices occur really in proteins.
5. 46 CFR 113.10-3 - Cable runs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs...
6. 46 CFR 113.10-3 - Cable runs.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs...
7. 46 CFR 188.10-3 - Approved container.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Approved container. 188.10-3 Section 188.10-3 Shipping... PROVISIONS Definition of Terms Used in This Subchapter § 188.10-3 Approved container. This term means a container which is properly labeled, marked and approved by DOT for the commodity which it contains....
8. 39 CFR 10.3 - Post-employment activities.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 39 Postal Service 1 2010-07-01 2010-07-01 false Post-employment activities. 10.3 Section 10.3 Postal Service UNITED STATES POSTAL SERVICE THE BOARD OF GOVERNORS OF THE U.S. POSTAL SERVICE RULES OF CONDUCT FOR POSTAL SERVICE GOVERNORS (ARTICLE X) § 10.3 Post-employment activities. Governors are...
9. 46 CFR 30.10-3 - Approved-TB/ALL.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 1 2010-10-01 2010-10-01 false Approved-TB/ALL. 30.10-3 Section 30.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10-3 Approved—TB/ALL. The term approved means approved by the Commandant unless otherwise stated....
10. 46 CFR 30.10-3 - Approved-TB/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Approved-TB/ALL. 30.10-3 Section 30.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10-3 Approved—TB/ALL. The term approved means approved by the Commandant unless otherwise stated....
11. 46 CFR 113.10-3 - Cable runs.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs...
12. 46 CFR 113.10-3 - Cable runs.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs...
13. 46 CFR 113.10-3 - Cable runs.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs...
14. 50 CFR 10.3 - Other applicable laws.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Other applicable laws. 10.3 Section 10.3... GENERAL PROVISIONS Introduction § 10.3 Other applicable laws. No statute or regulation of any State shall..., or customs laws or regulations, or other Service enforced statutes or regulations....
15. 46 CFR 76.10-3 - Water availability.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 3 2012-10-01 2012-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall...
16. 46 CFR 76.10-3 - Water availability.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 3 2010-10-01 2010-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall...
17. 46 CFR 76.10-3 - Water availability.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 3 2011-10-01 2011-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall...
18. 46 CFR 76.10-3 - Water availability.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 3 2014-10-01 2014-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall...
19. 46 CFR 76.10-3 - Water availability.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 3 2013-10-01 2013-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall...
20. Omega 3 oils and pregnancy.
PubMed
Gallagher, Shawn
2004-01-01
Women can safely commence omega 3 intake in early pregnancy to allow the full benefits to be incorporated into the body. Pregnant women should consider the intake of omega 3 oils and evening primrose oil throughout pregnancy in order possibly to prevent preterm delivery, promote an easier birth, assist the baby's brain and eye health and preprogram the baby's cell membranes for optimum lifelong wellness. Benefits to the mother may include prevention of postnatal depression and the comfort of knowing that she is giving her baby a healthy start in life.
1. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity
PubMed Central
Simopoulos, Artemis P.
2016-01-01
In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity. PMID:26950145
2. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity.
PubMed
Simopoulos, Artemis P
2016-03-02
In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity.
3. Digital time slot display for Omega receiver
NASA Technical Reports Server (NTRS)
Smith, R. E.
1976-01-01
Methods of decoding a digital word to display alpha-numeric characters for driving a standard seven-segment LED display have been devised for Omega station identification. The circuit could replace the system now being used in Ohio University's Omega receivers, which lights one of eight LED's to signify the Omega time slot being received. The letters A through H, representing the Omega stations, can be read directly from the seven-segment display.
4. Multivariate Analog of Hays Omega-Squared.
ERIC Educational Resources Information Center
Sachdeva, Darshan
The multivariate analog of Hays omega-squared for estimating the strength of the relationship in the multivariate analysis of variance has been proposed in this paper. The multivariate omega-squared is obtained through the use of Wilks' lambda test criterion. Application of multivariate omega-squared to a numerical example has been provided so as…
5. Measurement of the Omega0(c) lifetime
SciTech Connect
Iori, M.; Ayan, A.S.; Akgun, U.; Alkhazov, G.; Amaro-Reyes, J.; Atamantchouk, A.G.; Balatz, M.Y.; Blanco-Covarrubias, A.; Bondar, N.F.; Cooper, P.S.; Dauwe, L.J.; /Ball State U. /Bogazici U. /Carnegie Mellon U. /Rio de Janeiro, CBPF /Fermilab /Serpukhov, IHEP /Beijing, Inst. High Energy Phys. /Moscow, ITEP /Heidelberg, Max Planck Inst. /Moscow State U. /St. Petersburg, INP
2007-01-01
The authors report a precise measurement of the {Omega}{sub c}{sup 0} lifetime. The data were taken by the SELEX (E781) experiment using 600 GeV/c {Sigma}{sup -}, {pi}{sup -} and p beams. The measurement has been made using 83 {+-} 19 reconstructed {Omega}{sub c}{sup 0} in the {Omega}{sup -} {pi}{sup -}{pi}{sup +}{pi}{sup +} and {Omega}{sup -} {pi}{sup +} decay modes. The lifetime of the {Omega}{sub c}{sup 0} is measured to be 65 {+-} 13(stat) {+-} 9(sys) fs.
6. 22 CFR 19.10-3 - Marriage after retirement.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Marriage after retirement. 19.10-3 Section 19... PARTICIPANTS IN THE FOREIGN SERVICE RETIREMENT AND DISABILITY SYSTEM § 19.10-3 Marriage after retirement. If an... marriage irrevocably elect to receive a reduced annuity and to provide, subject to any obligation...
7. 22 CFR 19.10-3 - Marriage after retirement.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Marriage after retirement. 19.10-3 Section 19... PARTICIPANTS IN THE FOREIGN SERVICE RETIREMENT AND DISABILITY SYSTEM § 19.10-3 Marriage after retirement. If an... marriage irrevocably elect to receive a reduced annuity and to provide, subject to any obligation...
8. 22 CFR 19.10-3 - Marriage after retirement.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Marriage after retirement. 19.10-3 Section 19... PARTICIPANTS IN THE FOREIGN SERVICE RETIREMENT AND DISABILITY SYSTEM § 19.10-3 Marriage after retirement. If an... marriage irrevocably elect to receive a reduced annuity and to provide, subject to any obligation...
9. 22 CFR 19.10-3 - Marriage after retirement.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Marriage after retirement. 19.10-3 Section 19... PARTICIPANTS IN THE FOREIGN SERVICE RETIREMENT AND DISABILITY SYSTEM § 19.10-3 Marriage after retirement. If an... marriage irrevocably elect to receive a reduced annuity and to provide, subject to any obligation...
10. 22 CFR 19.10-3 - Marriage after retirement.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Marriage after retirement. 19.10-3 Section 19... PARTICIPANTS IN THE FOREIGN SERVICE RETIREMENT AND DISABILITY SYSTEM § 19.10-3 Marriage after retirement. If an... marriage irrevocably elect to receive a reduced annuity and to provide, subject to any obligation...
11. 46 CFR 25.10-3 - Navigation light certification requirements.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 1 2010-10-01 2010-10-01 false Navigation light certification requirements. 25.10-3... Navigation Lights § 25.10-3 Navigation light certification requirements. (a) Except as provided by paragraph (b) of this section, each navigation light must— (1) Meet the technical standards of the...
12. 43 CFR 10.3 - Intentional archaeological excavations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Intentional archaeological excavations. 10.3 Section 10.3 Public Lands: Interior Office of the Secretary of the Interior NATIVE AMERICAN GRAVES PROTECTION AND REPATRIATION REGULATIONS Human Remains, Funerary Objects, Sacred Objects, or Objects...
13. 43 CFR 10.3 - Intentional archaeological excavations.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Intentional archaeological excavations. 10.3 Section 10.3 Public Lands: Interior Office of the Secretary of the Interior NATIVE AMERICAN GRAVES PROTECTION AND REPATRIATION REGULATIONS Human Remains, Funerary Objects, Sacred Objects, or Objects...
14. 43 CFR 10.3 - Intentional archaeological excavations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Intentional archaeological excavations. 10.3 Section 10.3 Public Lands: Interior Office of the Secretary of the Interior NATIVE AMERICAN GRAVES PROTECTION AND REPATRIATION REGULATIONS Human Remains, Funerary Objects, Sacred Objects, or Objects...
15. 43 CFR 10.3 - Intentional archaeological excavations.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Intentional archaeological excavations. 10.3 Section 10.3 Public Lands: Interior Office of the Secretary of the Interior NATIVE AMERICAN GRAVES PROTECTION AND REPATRIATION REGULATIONS Human Remains, Funerary Objects, Sacred Objects, or Objects...
16. 43 CFR 10.3 - Intentional archaeological excavations.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Intentional archaeological excavations. 10.3 Section 10.3 Public Lands: Interior Office of the Secretary of the Interior NATIVE AMERICAN GRAVES PROTECTION AND REPATRIATION REGULATIONS Human Remains, Funerary Objects, Sacred Objects, or Objects...
17. 46 CFR 111.10-3 - Two generating sources.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS... drilling unit must have at least two electric generating sources....
18. 46 CFR 111.10-3 - Two generating sources.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS... drilling unit must have at least two electric generating sources....
19. 46 CFR 111.10-3 - Two generating sources.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS... drilling unit must have at least two electric generating sources....
20. 46 CFR 111.10-3 - Two generating sources.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS... drilling unit must have at least two electric generating sources....
1. 46 CFR 111.10-3 - Two generating sources.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS... drilling unit must have at least two electric generating sources....
2. 46 CFR 25.10-3 - Navigation light certification requirements.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 1 2013-10-01 2013-10-01 false Navigation light certification requirements. 25.10-3... Navigation Lights § 25.10-3 Navigation light certification requirements. (a) Except as provided by paragraph (b) of this section, each navigation light must— (1) Meet the technical standards of the...
3. 46 CFR 25.10-3 - Navigation light certification requirements.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Navigation light certification requirements. 25.10-3... Navigation Lights § 25.10-3 Navigation light certification requirements. (a) Except as provided by paragraph (b) of this section, each navigation light must— (1) Meet the technical standards of the...
4. 46 CFR 25.10-3 - Navigation light certification requirements.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 1 2012-10-01 2012-10-01 false Navigation light certification requirements. 25.10-3... Navigation Lights § 25.10-3 Navigation light certification requirements. (a) Except as provided by paragraph (b) of this section, each navigation light must— (1) Meet the technical standards of the...
5. 46 CFR 25.10-3 - Navigation light certification requirements.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 1 2014-10-01 2014-10-01 false Navigation light certification requirements. 25.10-3... Navigation Lights § 25.10-3 Navigation light certification requirements. (a) Except as provided by paragraph (b) of this section, each navigation light must— (1) Meet the technical standards of the...
6. Murray and the Omega Minus
SciTech Connect
Samios, N.P.
2010-08-20
The exciting findings and activities in particle physics in the 50's and 60's will be discussed from an experimentalist's viewpoint. Particular emphasis will be placed on the description of several crucial discoveries (including the omega minus) and on the remarkable insight, guidance, and major contributions of Murray Gell-Mann to the understanding of the symmetry of hadrons which led to the development of the standard model of the strong interactions.
7. Murray and the Omega Minus
Samios, Nicholas P.
The exciting findings and activities in particle physics in the 50's and 60's will be discussed from an experimentalist's viewpoint. Particular emphasis will be placed on the description of several crucial discoveries (including the omega minus) and on the remarkable insight, guidance, and major contributions of Murray Gell-Mann to the understanding of the symmetry of hadrons which led to the development of the standard model of the strong interactions.
8. Murray and the Omega Minus
Samios, Nicholas P.
2011-11-01
The exciting findings and activities in particle physics in the 50's and 60's will be discussed from an experimentalist's viewpoint. Particular emphasis will be placed on the description of several crucial discoveries (including the omega minus) and on the remarkable insight, guidance, and major contributions of Murray Gell-Mann to the understanding of the symmetry of hadrons which led to the development of the standard model of the strong interactions.
9. Omega-3 deficiency impairs honey bee learning
PubMed Central
Arien, Yael; Dag, Arnon; Zarchin, Shlomi; Masci, Tania
2015-01-01
Deficiency in essential omega-3 polyunsaturated fatty acids (PUFAs), particularly the long-chain form of docosahexaenoic acid (DHA), has been linked to health problems in mammals, including many mental disorders and reduced cognitive performance. Insects have very low long-chain PUFA concentrations, and the effect of omega-3 deficiency on cognition in insects has not been studied. We show a low omega-6:3 ratio of pollen collected by honey bee colonies in heterogenous landscapes and in many hand-collected pollens that we analyzed. We identified Eucalyptus as an important bee-forage plant particularly poor in omega-3 and high in the omega-6:3 ratio. We tested the effect of dietary omega-3 deficiency on olfactory and tactile associative learning of the economically highly valued honey bee. Bees fed either of two omega-3–poor diets, or Eucalyptus pollen, showed greatly reduced learning abilities in conditioned proboscis-extension assays compared with those fed omega-3–rich diets, or omega-3–rich pollen mixture. The effect on performance was not due to reduced sucrose sensitivity. Omega-3 deficiency also led to smaller hypopharyngeal glands. Bee brains contained high omega-3 concentrations, which were only slightly affected by diet, suggesting additional peripheral effects on learning. The shift from a low to high omega-6:3 ratio in the Western human diet is deemed a primary cause of many diseases and reduced mental health. A similar shift seems to be occurring in bee forage, possibly an important factor in colony declines. Our study shows the detrimental effect on cognitive performance of omega-3 deficiency in a nonmammal. PMID:26644556
10. Omega-X micromachining system
DOEpatents
Miller, Donald M.
1978-01-01
A micromachining tool system with X- and omega-axes is used to machine spherical, aspherical, and irregular surfaces with a maximum contour error of 100 nonometers (nm) and surface waviness of no more than 0.8 nm RMS. The omega axis, named for the angular measurement of the rotation of an eccentric mechanism supporting one end of a tool bar, enables the pulse increments of the tool toward the workpiece to be as little as 0 to 4.4 nm. A dedicated computer coordinates motion in the two axes to produce the workpiece contour. Inertia is reduced by reducing the mass pulsed toward the workpiece to about one-fifth of its former value. The tool system includes calibration instruments to calibrate the micromachining tool system. Backlash is reduced and flexing decreased by using a rotary table and servomotor to pulse the tool in the omega-axis instead of a ball screw mechanism. A thermally-stabilized spindle rotates the workpiece and is driven by a motor not mounted on the micromachining tool base through a torque-smoothing pulley and vibrationless rotary coupling. Abbe offset errors are almost eliminated by tool setting and calibration at spindle center height. Tool contour and workpiece contour are gaged on the machine; this enables the source of machining errors to be determined more readily, because the workpiece is gaged before its shape can be changed by removal from the machine.
11. The Effect of Low Omega-3/Omega-6 Ratio on Auditory Nerve Conduction in Rat Pups.
PubMed
2015-01-01
The biological effects of omega-3 and omega-6 fatty acids are determined by their mutual interactions. This interaction extremely affects various functions. Lower consumption of omega-3 during gestation leads to various disorders, even in hearing. We aimed to assess the effect of low omega-3/omega-6 ratios on auditory nerve conduction. In this experimental study, the auditory brainstem response test was performed on 24-day-old rat (n=14). The rats were divided into case (low omega-3/omega-6 ratio during gestation and lactation) and control groups. Variables such as P1, P3, and P4 absolute latency period, interpeaks (P3-P4, P1-P3, and P1-P4), and P4/P1 amplitude ratio were measured. We found an increased P4 omega-3/omega-6 ratio in the group with a low omega-3/omega-6 ratio (P<0.01). No significant difference was observed in the P1 and P3 absolute latency period between the studied groups (P>0.05). Also, no significant difference was observed between the groups with respect to the P1-P3 interpeak latency (IPL) periods (P>0.05); while the P1-P4 and P3-P4 IPLs were significantly increased in the group with a low omega-3/omega-6 ratio (P<0.05). The P4/P1 amplitude ratio significantly decreased in the group with a low omega-3/omega-6 ratio (P<0.05). Results confirmed the negative effects of low omega-3/omega-6 ratio on the auditory system and hearing.
12. FY15 LLNL OMEGA Experimental Programs
SciTech Connect
Heeter, R. F.; Baker, K. L.; Barrios, M. A.; Beckwith, M. A.; Casey, D. T.; Celliers, P. M.; Chen, H.; Coppari, F.; Fournier, K. B.; Fratanduono, D. E.; Frenje, J.; Huntington, C. M.; Kraus, R. G.; Lazicki, A. E.; Martinez, D. A.; McNaney, J. M.; Millot, M. A.; Pak, A. E.; Park, H. S.; Ping, Y.; Pollock, B. B.; Smith, R. F.; Wehrenberg, C. E.; Widmann, K.; Collins, G. W.; Landen, O. L.; Wan, A.; Hsing, W.
2015-12-04
In FY15, LLNL’s High-Energy-Density Physics (HED) and Indirect Drive Inertial Confinement Fusion (ICF-ID) programs conducted several campaigns on the OMEGA laser system and on the EP laser system, as well as campaigns that used the OMEGA and EP beams jointly. Overall these LLNL programs led 468 target shots in FY15, with 315 shots using just the OMEGA laser system, 145 shots using just the EP laser system, and 8 Joint shots using Omega and EP together. Approximately 25% of the total number of shots (56 OMEGA shots and 67 EP shots, including the 8 Joint shots) supported the Indirect Drive Inertial Confinement Fusion Campaign (ICF-ID). The remaining 75% (267 OMEGA shots and 86 EP shots) were dedicated to experiments for High-Energy-Density Physics (HED). Highlights of the various HED and ICF campaigns are summarized in the following reports.
13. FY14 LLNL OMEGA Experimental Programs
SciTech Connect
Heeter, R. F.; Fournier, K. B.; Baker, K.; Barrios, M.; Bernstein, L.; Brown, G.; Celliers, P.; Chen, H.; Coppari, F.; Fratanduono, D.; Johnson, M. G.; Huntington, C.; Jenei, A.; Kraus, R.; Ma, T.; Martinez, D.; McNabb, D.; Millot, M.; Moore, A.; Nagel, S.; Park, H. S.; Patel, P.; Perez, F.; Ping, Y.; Pollock, B.; Ross, J. S.; Rygg, J. R.; Smith, R.; Zylstra, A.; Collins, G.; Landen, O.; Wan, A.; Hsing, W.
2014-10-13
In FY14, LLNL’s High-Energy-Density Physics (HED) and Indirect Drive Inertial Confinement Fusion (ICF-ID) programs conducted several campaigns on the OMEGA laser system and on the EP laser system, as well as campaigns that used the OMEGA and EP beams jointly. Overall these LLNL programs led 324 target shots in FY14, with 246 shots using just the OMEGA laser system, 62 shots using just the EP laser system, and 16 Joint shots using Omega and EP together. Approximately 31% of the total number of shots (62 OMEGA shots, 42 EP shots) shots supported the Indirect Drive Inertial Confinement Fusion Campaign (ICF-ID). The remaining 69% (200 OMEGA shots and 36 EP shots, including the 16 Joint shots) were dedicated to experiments for High- Energy-Density Physics (HED). Highlights of the various HED and ICF campaigns are summarized in the following reports.
14. Serpentine Nanotubes in CM Chondrites
NASA Technical Reports Server (NTRS)
Zega, Thomas J.; Garvie, Laurence A. J.; Dodony, Istvan; Buseck, Peter R.
2004-01-01
The CM chondrites are primitive meteorites that formed during the early solar system. Although they retain much of their original physical character, their matrices and fine-grained rims (FGRs) sustained aqueous alteration early in their histories [1- 3]. Serpentine-group minerals are abundant products of such alteration, and information regarding their structures, compositions, and spatial relationships is important for determining the reactions that produced them and the conditions under which they formed. Our recent work on FGRs and matrices of the CM chondrites has revealed new information on the structures and compositions of serpentine-group minerals [4,5] and has provided insights into the evolution of these primitive meteorites. Here we report on serpentine nanotubes from the Mighei and Murchison CM chondrites [6].
15. 26 CFR 36.3121(l)(10)-3 - Returns.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 26 Internal Revenue 15 2011-04-01 2011-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...
16. 26 CFR 36.3121(l)(10)-3 - Returns.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 26 Internal Revenue 15 2014-04-01 2014-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...
17. 26 CFR 36.3121(l)(10)-3 - Returns.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 26 Internal Revenue 15 2013-04-01 2013-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...
18. 26 CFR 36.3121(l)(10)-3 - Returns.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...
19. 26 CFR 36.3121(l)(10)-3 - Returns.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 26 Internal Revenue 15 2012-04-01 2012-04-01 false Returns. 36.3121(l)(10)-3 Section 36.3121(l)(10....3121(l)(10)-3 Returns. (a) The forms prescribed for use in making returns of the taxes imposed by the... returns of its liability under an agreement entered into as provided in § 36.3121(l)(1)-1. Returns of...
20. Using Caenorhabditis elegans to Uncover Conserved Functions of Omega-3 and Omega-6 Fatty Acids
PubMed Central
Watts, Jennifer L.
2016-01-01
The nematode Caenorhabditis elegans is a powerful model organism to study functions of polyunsaturated fatty acids. The ability to alter fatty acid composition with genetic manipulation and dietary supplementation permits the dissection of the roles of omega-3 and omega-6 fatty acids in many biological process including reproduction, aging and neurobiology. Studies in C. elegans to date have mostly identified overlapping functions of 20-carbon omega-6 and omega-3 fatty acids in reproduction and in neurons, however, specific roles for either omega-3 or omega-6 fatty acids are beginning to emerge. Recent findings with importance to human health include the identification of a conserved Cox-independent prostaglandin synthesis pathway, critical functions for cytochrome P450 derivatives of polyunsaturated fatty acids, the requirements for omega-6 and omega-3 fatty acids in sensory neurons, and the importance of fatty acid desaturation for long lifespan. Furthermore, the ability of C. elegans to interconvert omega-6 to omega-3 fatty acids using the FAT-1 omega-3 desaturase has been exploited in mammalian studies and biotechnology approaches to generate mammals capable of exogenous generation of omega-3 fatty acids. PMID:26848697
1. Using Caenorhabditis elegans to Uncover Conserved Functions of Omega-3 and Omega-6 Fatty Acids.
PubMed
Watts, Jennifer L
2016-02-02
The nematode Caenorhabditis elegans is a powerful model organism to study functions of polyunsaturated fatty acids. The ability to alter fatty acid composition with genetic manipulation and dietary supplementation permits the dissection of the roles of omega-3 and omega-6 fatty acids in many biological process including reproduction, aging and neurobiology. Studies in C. elegans to date have mostly identified overlapping functions of 20-carbon omega-6 and omega-3 fatty acids in reproduction and in neurons, however, specific roles for either omega-3 or omega-6 fatty acids are beginning to emerge. Recent findings with importance to human health include the identification of a conserved Cox-independent prostaglandin synthesis pathway, critical functions for cytochrome P450 derivatives of polyunsaturated fatty acids, the requirements for omega-6 and omega-3 fatty acids in sensory neurons, and the importance of fatty acid desaturation for long lifespan. Furthermore, the ability of C. elegans to interconvert omega-6 to omega-3 fatty acids using the FAT-1 omega-3 desaturase has been exploited in mammalian studies and biotechnology approaches to generate mammals capable of exogenous generation of omega-3 fatty acids.
2. 344 cm x 86 cm low mass vacuum window
SciTech Connect
Reimers, R.M.; Porter, J.; Meneghetti, J.; Wilde, S.; Miller, R.
1983-08-01
The LBL Heavy Ion Spectrometer System (HISS) superconducting magnet contains a 1 m x 3.45 m x 2 m vacuum tank in its gap. A full aperture thin window was needed to minimize background as the products of nuclear collisions move from upstream targets to downstream detectors. Six windows were built and tested in the development process. The final window's unsupported area is 3m/sup 2/ with a 25 cm inward deflection. The design consists of a .11 mm Nylon/aluminum/polypropylene laminate as a gas seal and .55 mm woven aramid fiber for strength. Total mass is 80 milligrams per cm/sup 2/. Development depended heavily on past experience and testing. Safety considerations are discussed.
3. High-Z Coating Experiments on Omega EP
Karasik, Max; Oh, J.; Stoeckl, C.; Schmitt, A. J.; Aglitskiy, Y.; Obenschain, S. P.
2016-10-01
Previous experiments on Nike KrF laser (λ=248nm) at NRL found that a thin (400-800 Å) high-Z (Au or Pd) overcoat on the target is effective in suppressing broadband imprint. Implementation of this technique on the tripled Nd:glass (351nm) NIF would enable higher uniformity direct-drive experiments there. To this end, we are carrying out experiments using the NIF-like beams of Omega EP. On Nike, a low-intensity, highly smooth prepulse heats and pre-expands the low thermal mass metallic coating to 100 um scale length. This likely improves imprint reduction for longer spatial scales because of increased distance between laser absorption and the ablation surface. The 3 ω beams of Omega EP do not have this feature due to nonlinear harmonic conversion. We introduced a means of pre-expanding the high-Z coating to similar length scale on Omega EP using a soft x-ray prepulse, generated by irradiating an auxiliary Au foil 1cm in front of the main target tens of ns prior to the main target drive. Coating dynamics are measured using side-on radiography. The effectiveness of pre-expansion on imprint reduction will be assessed by measurements of the RT-amplified imprint using monochromatic curved crystal radiography. Work supported by the Department of Energy/NNSA.
4. The MicrOmega Investigation Onboard Hayabusa2
Bibring, J.-P.; Hamm, V.; Langevin, Y.; Pilorget, C.; Arondel, A.; Bouzit, M.; Chaigneau, M.; Crane, B.; Darié, A.; Evesque, C.; Hansotte, J.; Gardien, V.; Gonnod, L.; Leclech, J.-C.; Meslier, L.; Redon, T.; Tamiatto, C.; Tosti, S.; Thoores, N.
2017-03-01
MicrOmega is a near-IR hyperspectral microscope designed to characterize in situ the texture and composition of the surface materials of the Hayabusa2 target asteroid. MicrOmega is implemented within the MASCOT lander (Ho et al. in Space Sci. Rev., 2016, this issue, doi:10.1007/s11214-016-0251-6). The spectral range (0.99-3.65 μm) and the spectral sampling ( 20 cm^{-1}) of MicrOmega have been chosen to allow the identification of most potential constituent minerals, ices and organics, within each 25 μm pixel of the 3.2× 3.2 mm2 FOV. Such an unprecedented characterization will (1) enable the identification of most major and minor phases, including the potential organic phases, and ascribe their mineralogical context, as a critical set of clues to decipher the origin and evolution of this primitive body, and (2) provide the ground truth for the orbital measurements as well as a reference for the analyses later performed on returned samples.
5. Modulation of prostate cancer genetic risk by omega-3 and omega-6 fatty acids
PubMed Central
Berquin, Isabelle M.; Min, Younong; Wu, Ruping; Wu, Jiansheng; Perry, Donna; Cline, J. Mark; Thomas, Mike J.; Thornburg, Todd; Kulik, George; Smith, Adrienne; Edwards, Iris J.; D’Agostino, Ralph; Zhang, Hao; Wu, Hong; Kang, Jing X.; Chen, Yong Q.
2007-01-01
Although a causal role of genetic alterations in human cancer is well established, it is still unclear whether dietary fat can modulate cancer risk in a predisposed population. Epidemiological studies suggest that diets rich in omega-3 polyunsaturated fatty acids reduce cancer incidence. To determine the influence of fatty acids on prostate cancer risk in animals with a defined genetic lesion, we used prostate-specific Pten-knockout mice, an immune-competent, orthotopic prostate cancer model, and diets with defined polyunsaturated fatty acid levels. We found that omega-3 fatty acids reduced prostate tumor growth, slowed histopathological progression, and increased survival, whereas omega-6 fatty acids had opposite effects. Introducing an omega-3 desaturase, which converts omega-6 to omega-3 fatty acids, into the Pten-knockout mice reduced tumor growth similarly to the omega-3 diet. Tumors from mice on the omega-3 diet had lower proportions of phosphorylated Bad and higher apoptotic indexes compared with those from mice on omega-6 diet. Knockdown of Bad eliminated omega-3–induced cell death, and introduction of exogenous Bad restored the sensitivity to omega-3 fatty acids. Our data suggest that modulation of prostate cancer development by polyunsaturated fatty acids is mediated in part through Bad-dependent apoptosis. This study highlights the importance of gene-diet interactions in prostate cancer. PMID:17607361
6. FY16 LLNL Omega Experimental Programs
SciTech Connect
Heeter, R. F.; Ali, S. J.; Benstead, J.; Celliers, P. M.; Coppari, F.; Eggert, J.; Erskine, D.; Panella, A. F.; Fratanduono, D. E.; Hua, R.; Huntington, C. M.; Jarrott, L. C.; Jiang, S.; Kraus, R. G.; Lazicki, A. E.; LePape, S.; Martinez, D. A.; McNaney, J. M.; Millot, M. A.; Moody, J.; Pak, A. E.; Park, H. S.; Ping, Y.; Pollock, B. B.; Rinderknecht, H.; Ross, J. S.; Rubery, M.; Sio, H.; Smith, R. F.; Swadling, G. F.; Wehrenberg, C. E.; Collins, G. W.; Landen, O. L.; Wan, A.; Hsing, W.
2016-12-01
In FY16, LLNL’s High-Energy-Density Physics (HED) and Indirect Drive Inertial Confinement Fusion (ICF-ID) programs conducted several campaigns on the OMEGA laser system and on the EP laser system, as well as campaigns that used the OMEGA and EP beams jointly. Overall these LLNL programs led 430 target shots in FY16, with 304 shots using just the OMEGA laser system, and 126 shots using just the EP laser system. Approximately 21% of the total number of shots (77 OMEGA shots and 14 EP shots) supported the Indirect Drive Inertial Confinement Fusion Campaign (ICF-ID). The remaining 79% (227 OMEGA shots and 112 EP shots) were dedicated to experiments for High-Energy- Density Physics (HED). Highlights of the various HED and ICF campaigns are summarized in the following reports. In addition to these experiments, LLNL Principal Investigators led a variety of Laboratory Basic Science campaigns using OMEGA and EP, including 81 target shots using just OMEGA and 42 shots using just EP. The highlights of these are also summarized, following the ICF and HED campaigns. Overall, LLNL PIs led a total of 553 shots at LLE in FY 2016. In addition, LLNL PIs also supported 57 NLUF shots on Omega and 31 NLUF shots on EP, in collaboration with the academic community.
7. LLNL Experiments at OMEGA in FY05
SciTech Connect
Turner, R E
2005-10-06
During FY05, LLNL was scheduled for 372 shots on Omega. These were distributed into 191 planned shots for the Inertial Confinement Fusion (ICF) program, and 181 planned shots for the High Energy Density Sciences (HEDS) program. The actual Omega performance averaged 6% more shots than scheduled. A brief summary of the various campaigns follows, starting with HEDS experiments.
8. M54 + SAGITTARIUS = {omega} CENTAURI
SciTech Connect
Carretta, E.; Bragaglia, A.; Bellazzini, M.; Gratton, R. G.; Lucatello, S.; Momany, Y.; D'Orazi, V.; Catanzaro, G.; Leone, F.; Piotto, G. E-mail: angela.bragaglia@oabo.inaf.it E-mail: raffaele.gratton@oapd.inaf.it E-mail: valentina.dorazi@oapd.inaf.it
2010-05-01
We derive homogeneous abundances of Fe, O, Na, and {alpha}-elements from high-resolution FLAMES spectra for 76 red giant stars in NGC 6715 (M54) and for 25 red giants in the surrounding nucleus of the Sagittarius (Sgr) dwarf galaxy. Our main findings are the following. (1) We confirm that M54 shows intrinsic metallicity dispersion, {approx}0.19 dex rms. (2) When the stars of the Sgr nucleus are included, the metallicity distribution strongly resembles that in {omega} Cen; the relative contribution of the most metal-rich stars is, however, different in these two objects. (3) In both globular clusters (GCs) there is a very extended Na-O anticorrelation, which is a signature of different stellar generations born within the cluster. (4) The metal-poor and metal-rich components in M54 (and {omega} Cen) show clearly distinct extension of the Na-O anticorrelation, the most heavily polluted stars being those of the metal-rich component. We propose a tentative scenario for cluster formation that could explain these features. Finally, similarities and differences found in the two most massive GCs in our Galaxy can be easily explained if they are similar objects (nuclear clusters in dwarf galaxies) observed at different stages of their dynamical evolution.
9. 46 CFR 39.10-3 - Definitions-TB/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS VAPOR CONTROL SYSTEMS General § 39.10-3... processing unit. Vapor control system means an arrangement of piping and equipment used to control vapor... processing unit means the components of a vapor control system that recovers, destroys, or disperses...
10. 46 CFR 39.10-3 - Definitions-TB/ALL.
Code of Federal Regulations, 2010 CFR
2010-10-01
... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS VAPOR CONTROL SYSTEMS General § 39.10-3... processing unit. Vapor control system means an arrangement of piping and equipment used to control vapor... processing unit means the components of a vapor control system that recovers, destroys, or disperses...
11. Observation of an Excited Charm Baryon Omega^*_C Decaying to Omega^0_C Gamma
SciTech Connect
Aubert, B
2006-11-15
The authors report the first observation of an excited singly-charmed baryon {Omega}*{sub c} (css) in the radiative decay {Omega}{sub c}{sup 0}{gamma}, where the {Omega}{sub c}{sup 0} baryon is reconstructed in the decays to the final states {Omega}{sup -}{pi}{sup +}, {Omega}{sup -} {pi}{sup +}{pi}{sup 0}, {Omega}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}, and {Xi}{sup -} K{sup -} {pi}{sup +}{pi}{sup +}. This analysis is performed using a dataset of 230.7 fb{sup -1} collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The mass difference between the {Omega}*{sub c} and the {Omega}{sub c}{sup 0} baryons is measured to be 70.8 {+-} 1.0(stat) {+-} 1.1(syst) MeV/c{sup 2}. They also measure the ratio of inclusive production cross sections of {Omega}*{sub c} and {Omega}{sub c}{sup 0} in e{sup +}e{sup -} annihilation.
12. Omega-3 fatty acids and neuropsychiatric disorders.
PubMed
Young, Genevieve; Conquer, Julie
2005-01-01
Epidemiological evidence suggests that dietary consumption of the long chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), commonly found in fish or fish oil, may modify the risk for certain neuropsychiatric disorders. As evidence, decreased blood levels of omega-3 fatty acids have been associated with several neuropsychiatric conditions, including Attention Deficit (Hyperactivity) Disorder, Alzheimer's Disease, Schizophrenia and Depression. Supplementation studies, using individual or combination omega-3 fatty acids, suggest the possibility for decreased symptoms associated with some of these conditions. Thus far, however, the benefits of supplementation, in terms of decreasing disease risk and/or aiding in symptom management, are not clear and more research is needed. The reasons for blood fatty acid alterations in these disorders are not known, nor are the potential mechanisms by which omega-3 fatty acids may function in normal neuronal activity and neuropsychiatric disease prevention and/or treatment. It is clear, however, that DHA is the predominant n-3 fatty acid found in the brain and that EPA plays an important role as an anti-inflammatory precursor. Both DHA and EPA can be linked with many aspects of neural function, including neurotransmission, membrane fluidity, ion channel and enzyme regulation and gene expression. This review summarizes the knowledge in terms of dietary omega-3 fatty acid intake and metabolism, as well as evidence pointing to potential mechanisms of omega-3 fatty acids in normal brain functioning, development of neuropsychiatric disorders and efficacy of omega-3 fatty acid supplementation in terms of symptom management.
13. Understanding the branching ratios of {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega}, {omega}{phi} observed at BES-III
SciTech Connect
Chen Dianyong; He Jun; Li Xueqian; Liu Xiang
2010-04-01
In this work, we discuss the contribution of the mesonic loops to the decay rates of {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega}, which are suppressed by the helicity selection rules and {chi}{sub c1{yields}{phi}{omega}}, which is a double-Okubo-Zweig-Iizuka forbidden process. We find that the mesonic loop effects naturally explain the clear signals of {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega} decay modes observed by the BES Collaboration. Moreover, we investigate the effects of the {omega}-{phi} mixing, which may result in the order of magnitude of the branching ratio BR({chi}{sub c1{yields}{omega}{phi}}) being 10{sup -7}. Thus, we are waiting for the accurate measurements of the BR({chi}{sub c1{yields}{omega}{omega}}), BR({chi}{sub c1{yields}{phi}{phi}}), and BR({chi}{sub c1{yields}{omega}{phi}}), which may be very helpful for testing the long-distant contribution and the {omega}-{phi} mixing in {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega}, {omega}{phi} decays.
14. Diurnal measurements with prototype CMOS Omega receivers
NASA Technical Reports Server (NTRS)
Burhans, R. W.
1976-01-01
Diurnal signals from eight omega channels have been monitored at 10.2 KHz for selected station pairs. All eight Omega stations have been received at least 50 percent of the time over a 24 hour period during the month of October 1976. The data presented confirm the expected performance of the CMOS omega sensor processor in being able to digsignals out of a noisy environment. Of particular interest are possibilities for use of antipodal reception phenomena and a need for some ways of correcting for multi-modal propagation effects.
15. Omega Navigation System Course Book. Volume 1.
DTIC Science & Technology
1994-07-01
operational information needed to understand the characteristics, operation, and use of the Omega Navigation System. It is designed to be used as a self-paced...guard time) between the signal transmissions in the Omega signal format was chosen to be 0.2 sec? Answer: The interval is designed for the worst...as Radux-Omega, was designed to use the 200 Hz m•Julation to resolve the (approximately) 8 nautical mile "lane"* of the 10 kHz transmission. This
16. Mars Express OMEGA Observations over Terra Meridiani
NASA Technical Reports Server (NTRS)
Arvidson, R. E.; Poulet, F.; Bibring, J.-P.; Wolff, M.; Gendrin, A.; Morris, R. V.; Freeman, J. J.; Bellucci, G.
2005-01-01
The OMEGA hyperspectral imager (0.35 to 5.08 micrometers) covered the hematite-bearing plains and underlying etched terrains of Terra Meridiani during several orbits with spatial resolutions ranging from several hundred meters to approximately 2 km. We extracted and analyzed surface reflectance spectra from OMEGA data for the approximately 864,000 square kilometers surrounding the Opportunity site. In this paper we focus on analysis of OMEGA orbit 485 data for the plains and etched terrains located to the northeast of the Opportunity landing site.
17. Laser-Driven Magnetized Liner Inertial Fusion on OMEGA
Barnak, D. H.
2016-10-01
Magneto-inertial fusion (MIF) is an approach that combines the implosion and compression of fusion fuel (a hallmark of inertial fusion) with strongly magnetized plasmas that suppress electron heat losses (a hallmark of magnetic fusion). It is of interest because it could potentially reduce some of the traditional velocity, pressure, and convergence ratio requirements of inertial confinement fusion (ICF). The magnetized liner inertial fusion (MagLIF) concept being studied at the Z Pulsed-Power Facility is a key target concept in the U.S. ICF Program. Laser-driven MagLIF is being developed to enable a test of the scaling of MagLIF over a range of absorbed energy from of the order of 20 kJ (on OMEGA) to 500 kJ (on Z). It is also valuable as a platform for studying the key physics of MIF. An energy-scaled point design has been developed for the Omega Laser Facility that is roughly 10 × smaller in linear dimensions than Z MagLIF targets. A 0.6-mm-outer-diam plastic cylinder filled with 2.4 mg/cm3 of D2 is placed in a 10-T axial magnetic field, generated by MIFEDS (magneto-inertial fusion electrical discharge system), the cylinder is compressed by 40 OMEGA beams, and the gas fill is preheated by a single OMEGA beam propagating along the axis. Preheating to >100 eV and axially uniform compression over a 0.7-mm height have been demonstrated, separately, in a series of preparatory experiments that meet our initial expectations. Preliminary results from the first integrated experiments combining magnetization, compression, and preheat will be reported for the first time. The scaling of laser-driven MagLIF from OMEGA up to the 1800 kJ available on the NIF (National Ignition Facility) will also be described briefly. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.
18. Detecting charged fusion products in high-fluence conditions on OMEGA and the NIF
Waugh, C.; Rosenberg, M.; Zylstra, A.; Rinderknecht, H.; Sinenian, N.; Manuel, M.; Casey, D.; Gatu Johnson, M.; Li, C. K.; Seguin, F.; Frenje, J.; Petrasso, R.; Glebov, V.; Sangster, T. C.; Pape, S.; Bionta, R.; MacKinnon, A.; Landen, O.; Kim, Y.; Hermann, H.; Kilkenny, J.; Nikroo, A.
2011-10-01
CR-39 solid state nuclear track plastic, used as charged particle detectors on the back-end'' of OMEGA and NIF diagnostics/spectrometers, is ideally suited to record particle fluences up to ~ 3x104 / cm2. However, conditions on OMEGA and the NIF can often result in fluences two orders of magnitude greater. By using shorter etch times than the standard (6 hrs), and cross calibrating to CR39 shot on the MIT accelerator to the equivalent (ICF) fluence, the dynamic range of the CR39 can be significantly extended. Specific examples of this analysis from both OMEGA and the NIF will be presented for the case of D3He exploding pushers. This work was supported in part by LLE, the NLUF, the FSC, the US DOE, LLNL, and GA.
19. Reactive Carbonyl Species Derived from Omega-3 and Omega-6 Fatty Acids.
PubMed
Wang, Yu; Cui, Ping
2015-07-22
Inflammation-related reactive oxygen species (ROS) and reactive nitrogen species (RNS) are associated with the development of cancer. ROS and RNS can directly damage biomacromolecules such as proteins, DNA, and lipids. Lipid peroxidation, however, can result in reactive carbonyl species (RCS) that can also modify proteins and DNA. In contrast to an extensive literature on the modification of proteins and DNA from omega-6 fatty acids, there are few studies on RCS generation from other fatty acids, particularly omega-3 fatty acids, which are frequently consumed from the diet and diet supplements. Therefore, a comparison between omega-3 and omega-6 fatty acids has been conducted. LC-MS/MS analysis of carbonyl-dinitrophenylhydrazine (DNPH) standards yielded characteristic fragment ions. Autoxidation products of α-linolenic acid and linoleic acid were then derivatized with DNPH and analyzed by LC-MS/MS. The results showed that α-linolenic acid, an omega-3 fatty acid, generated more acrolein and crotonaldehyde than did linoleic acid, an omega-6 fatty acid. Omega-3 fatty acids might be easily degraded to smaller monoaldehydes or dicarbonyls. Omega-3 fatty acids have been considered as health improvement components for a long time. However, on the basis of the results presented here, use of omega-3 fatty acids should be re-evaluated in vivo for safety purposes.
20. Phase-matched four-wave mixing of sub-100-TW/ cm2 femtosecond laser pulses in isolated air-guided modes of a hollow photonic-crystal fiber.
PubMed
Konorov, S O; Serebryannikov, E E; Akimov, D A; Ivanov, A A; Alfimov, M V; Zheltikov, A M
2004-12-01
Hollow-core photonic-crystal fibers are shown to allow propagation and nonlinear-optical frequency conversion of high-intensity ultrashort laser pulses in the regime of isolated guided modes confined in the hollow gas-filled fiber core. With a specially designed dispersion of such modes, the 3omega=2omega+2omega-omega four-wave mixing of fundamental (omega) and second-harmonic (2omega) sub-100- TW/ cm(2) femtosecond pulses of a Cr:forsterite laser can be phase matched in a hollow photonic-crystal fiber within a spectral band of more than 10 nm, resulting in the efficient generation of femtosecond pulses in a well-resolved higher-order air-guided mode of 417-nm radiation.
1. OMEGA for the Future of Biofuels
NASA Technical Reports Server (NTRS)
Trent, Jonathan
2010-01-01
OMEGA: Offshore Membrane Enclosure for Growing Algae. To develop a photobioreactor (PBR) for growing algae (Oil, food, fertilizer) that does not compete with agriculture for land (deployed offshore), water or fertilizer (uses/treats wastewater).
2. Zooming in on Omega Centauri Stellar Motion
NASA Video Gallery
This movie sequence begins with a ground-based image of the giant globular star cluster Omega Centauri and zooms very tightly in to a Hubble Space Telescope image of the central region of the clust...
3. Elementary Education: What Is Project Omega?
ERIC Educational Resources Information Center
Kirman, Joseph M.
1980-01-01
Describes Project Omega for Research in Remote Sensing Education, a program in space education designed for inservice training of elementary social studies teachers. Explains a few research areas dealing with the classroom applications of Landsat imagery. (CS)
4. North Pacific Omega Navigation System Validation.
DTIC Science & Technology
1981-12-31
based upon comparisons with "Loran-C, radar and visual" whose absolute accuracy as references could not be assessed. Similarly, the M/S Nopal Lane...Mellon ..................................... A-82 A5.1.5 M/S Nopal Lane ................... ......... .... .. A-83 A5.1.6 Submarine Omega Performance...From Omega Log of M/S NOPAL LANE .................... A-84 A5-2 Western Airlines Flights - 1978 .......................... A-85 AA-1 Difference Between
5. Optical Omega network: a compact implementation technique
Wong, K. W.; Cheng, L. M.
1995-10-01
We propose a technique for the compact implementation of an optical Omega network. This technique utilizes the concept that both the perfect-shuffle interconnection and the switching stages can be realized by the same procedures, i.e., duplicate, shift, superimpose, and mask. As a result, a single set of optics is sufficient to realize the whole Omega network in a time-multiplexed recursive manner. Optical setups were designed and a proof-of-principle experiment was performed.
6. Omega-3 fatty acids and cardiovascular disease.
PubMed
Jain, A P; Aggarwal, K K; Zhang, P-Y
2015-01-01
Cardioceuticals are nutritional supplements that contain all the essential nutrients including vitamins, minerals, omega-3-fatty acids and other antioxidants like a-lipoic acid and coenzyme Q10 in the right proportion that provide all round protection to the heart by reducing the most common risks associated with the cardiovascular disease including high low-density lipoprotein cholesterol and triglyceride levels and factors that contribute to coagulation of blood. Omega-3 fatty acids have been shown to significantly reduce the risk for sudden death caused by cardiac arrhythmias and all-cause mortality in patients with known coronary heart disease. Omega-3 fatty acids are also used to treat hyperlipidemia and hypertension. There are no significant drug interactions with omega-3 fatty acids. The American Heart Association recommends consumption of two servings of fish per week for persons with no history of coronary heart disease and at least one serving of fish daily for those with known coronary heart disease. Approximately 1 g/day of eicosapentaenoic acid plus docosahexaenoic acid is recommended for cardio protection. Higher dosages of omega-3 fatty acids are required to reduce elevated triglyceride levels (2-4 g/day). Modest decreases in blood pressure occur with significantly higher dosages of omega-3 fatty acids.
7. Neurological benefits of omega-3 fatty acids.
PubMed
Dyall, S C; Michael-Titus, A T
2008-01-01
The central nervous system is highly enriched in long-chain polyunsaturated fatty acid (PUFA) of the omega-6 and omega-3 series. The presence of these fatty acids as structural components of neuronal membranes influences cellular function both directly, through effects on membrane properties, and also by acting as a precursor pool for lipid-derived messengers. An adequate intake of omega-3 PUFA is essential for optimal visual function and neural development. Furthermore, there is increasing evidence that increased intake of the long-chain omega-3 PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may confer benefits in a variety of psychiatric and neurological disorders, and in particular neurodegenerative conditions. However, the mechanisms underlying these beneficial effects are still poorly understood. Recent evidence also indicates that in addition to the positive effects seen in chronic neurodegenerative conditions, omega-3 PUFA may also have significant neuroprotective potential in acute neurological injury. Thus, these compounds offer an intriguing prospect as potentially new therapeutic approaches in both chronic and acute conditions. The purpose of this article is to review the current evidence of the neurological benefits of omega-3 PUFA, looking specifically at neurodegenerative conditions and acute neurological injury.
8. Barium Abundances in Omega Centauri Candidate Stars
Skipper, Joy Nicole; Sobeck, Jennifer; Majewski, Steven R.; Rochford Hayes, Christian; Cunha, Katia M. L.; Smith, Verne V.; Damke, Guillermo; García Pérez, Ana; Nidever, David L.
2017-01-01
The "globular cluster" omega Centauri has several peculiar features that set it apart from other Milky Way globular clusters, such as its large mass, extended size, oblate shape, internal rotation, large age and metallicity spreads, and retrograde orbit. Because of these properties it is thought that Omega Cen may be a heavily stripped remnant of a Milky Way-captured dwarf spheroidal galaxy, now currently orbiting (backwards) near the Galactic plane (e.g., Lee et al. 1999, Majewski et al. 2000). A previous search within a large, all-sky low resolution spectroscopic and photometric catalog of giant stars by Majewski et al. (2012) identified candidate retrograde stars near that plane also having kinematics consistent with being stripped debris from omega Cen, based on tidal destruction models of the system. To confirm their status as omega Centauri members, high resolution spectroscopy was undertaken of a subsample of a dozen of these candidates, and most were found by Majewski et al. to exhibit very high relative Ba abundances (as measured by the 5854 transition) — a peculiar characteristic of the omega Centauri system as originally shown by Smith et al. (2000) and Norris & Da Costa (1998). Thus, these results showed the likelihood of a connection between these widely distributed field stars and omega Centauri.We have continued this spectroscopic investigation with an expanded sample of candidate tidally-stripped omega Cen giant stars. High-resolution spectra were obtained in the wavelength region (4140~6210A) with the Ultraviolet Visual Echelle Spectrograph (UVES) on the 8.0-m Very Large Telescope (VLT) for additional candidates. For these data, we have employed multiple transitions to derive reliable [Ba/Fe] ratios. We will compare these and other derived abundances to those of the omega Cen core, other globular cluster and field stars. Any additionally-confirmed omega Cen debris stars to combine with those from the previous studies will allow for a more
9. Measurements of B meson decays to (omega)K* and (omega)(rho)
SciTech Connect
Aubert, B; Cheng, C H; Lange, D J; Simani, M C; . Wright, D M; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R H; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Y G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Abe, T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, G; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Keith, D W . S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Soha, A; Stelzer, H; Strube, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Collaboration, B
2006-03-14
The authors describe searches for B meson decays to the charmless vector-vector final states {omega}K* and {omega}{rho} in 89 million B{bar B} pairs produced in e{sup +}e{sup -} annihilation at {radical}s = 10.58 GeV.
10. Meat quality of Argentinean "Camperos" chicken enhanced in omega-3 and omega-9 fatty acids.
PubMed
Azcona, J O; Garcia, P T; Cossu, M E; Iglesias, B F; Picallo, A; Perez, C; Gallinger, C I; Schang, M J; Canet, Z E
2008-07-01
11. Balancing omega-6 and omega-3 fatty acids in ready-to-use therapeutic foods (RUTF).
PubMed
Brenna, J Thomas; Akomo, Peter; Bahwere, Paluku; Berkley, James A; Calder, Philip C; Jones, Kelsey D; Liu, Lei; Manary, Mark; Trehan, Indi; Briend, André
2015-05-15
Ready-to-use therapeutic foods (RUTFs) are a key component of a life-saving treatment for young children who present with uncomplicated severe acute malnutrition in resource limited settings. Increasing recognition of the role of balanced dietary omega-6 and omega-3 polyunsaturated fatty acids (PUFA) in neurocognitive and immune development led two independent groups to evaluate RUTFs. Jones et al. (BMC Med 13:93, 2015), in a study in BMC Medicine, and Hsieh et al. (J Pediatr Gastroenterol Nutr 2015), in a study in the Journal of Pediatric Gastroenterology and Nutrition, reformulated RUTFs with altered PUFA content and looked at the effects on circulating omega-3 docosahexaenoic acid (DHA) status as a measure of overall omega-3 status. Supplemental oral administration of omega-3 DHA or reduction of RUTF omega-6 linoleic acid using high oleic peanuts improved DHA status, whereas increasing omega-3 alpha-linolenic acid in RUTF did not. The results of these two small studies are consistent with well-established effects in animal studies and highlight the need for basic and operational research to improve fat composition in support of omega-3-specific development in young children as RUTF use expands.
12. Thermodynamical properties of dark energy with the equation of state {omega}={omega}{sub 0}+{omega}{sub 1}z
SciTech Connect
Zhang Yongping; Yi Zelong; Zhang Tongjie; Liu Wenbiao
2008-01-15
The thermodynamical properties of dark energy are usually investigated with the equation of state {omega}={omega}{sub 0}+{omega}{sub 1}z. Recent observations show that our Universe is accelerating, and the apparent horizon and the event horizon vary with redshift z. Because definitions of the temperature and entropy of a black hole are used to describe the two horizons of the Universe, we examine the thermodynamical properties of the Universe, which is enveloped by the apparent horizon and the event horizon, respectively. We show that the first and the second laws of thermodynamics inside the apparent horizon in any redshift are satisfied, while they are broken down inside the event horizon in some redshifts. Therefore, the apparent horizon for the Universe may be the boundary of thermodynamical equilibrium for the Universe like the event horizon for a black hole.
13. Rare B Meson Decays With Omega Mesons
SciTech Connect
2006-04-24
Rare charmless hadronic B decays are particularly interesting because of their importance in understanding the CP violation, which is essential to explain the matter-antimatter asymmetry in our universe, and of their roles in testing the ''effective'' theory of B physics. The study has been done with the BABAR experiment, which is mainly designed for the study of CP violation in the decays of neutral B mesons, and secondarily for rare processes that become accessible with the high luminosity of the PEP-II B Factory. In a sample of 89 million produced B{bar B} pairs on the BABAR experiment, we observed the decays B{sup 0} {yields} {omega}K{sup 0} and B{sup +} {yields} {omega}{rho}{sup +} for the first time, made more precise measurements for B{sup +} {yields} {omega}h{sup +} and reported tighter upper limits for B {yields} {omega}K* and B{sup 0} {yields} {omega}{rho}{sup 0}.
14. A protective lipidomic biosignature associated with a balanced omega-6/omega-3 ratio in fat-1 transgenic mice.
PubMed
Astarita, Giuseppe; McKenzie, Jennifer H; Wang, Bin; Strassburg, Katrin; Doneanu, Angela; Johnson, Jay; Baker, Andrew; Hankemeier, Thomas; Murphy, James; Vreeken, Rob J; Langridge, James; Kang, Jing X
2014-01-01
A balanced omega-6/omega-3 polyunsaturated fatty acid (PUFA) ratio has been linked to health benefits and the prevention of many chronic diseases. Current dietary intervention studies with different sources of omega-3 fatty acids (omega-3) lack appropriate control diets and carry many other confounding factors derived from genetic and environmental variability. In our study, we used the fat-1 transgenic mouse model as a proxy for long-term omega-3 supplementation to determine, in a well-controlled manner, the molecular phenotype associated with a balanced omega-6/omega-3 ratio. The fat-1 mouse can convert omega-6 to omega-3 PUFAs, which protect against a wide variety of diseases including chronic inflammatory diseases and cancer. Both wild-type (WT) and fat-1 mice were subjected to an identical diet containing 10% corn oil, which has a high omega-6 content similar to that of the Western diet, for a six-month duration. We used a multi-platform lipidomic approach to compare the plasma lipidome between fat-1 and WT mice. In fat-1 mice, an unbiased profiling showed a significant increase in the levels of unesterified eicosapentaenoic acid (EPA), EPA-containing cholesteryl ester, and omega-3 lysophosphospholipids. The increase in omega-3 lipids is accompanied by a significant reduction in omega-6 unesterified docosapentaenoic acid (omega-6 DPA) and DPA-containing cholesteryl ester as well as omega-6 phospholipids and triacylglycerides. Targeted lipidomics profiling highlighted a remarkable increase in EPA-derived diols and epoxides formed via the cytochrome P450 (CYP450) pathway in the plasma of fat-1 mice compared with WT mice. Integration of the results of untargeted and targeted analyses has identified a lipidomic biosignature that may underlie the healthful phenotype associated with a balanced omega-6/omega-3 ratio, and can potentially be used as a circulating biomarker for monitoring the health status and the efficacy of omega-3 intervention in humans.
15. A Protective Lipidomic Biosignature Associated with a Balanced Omega-6/Omega-3 Ratio in fat-1 Transgenic Mice
PubMed Central
Wang, Bin; Strassburg, Katrin; Doneanu, Angela; Johnson, Jay; Baker, Andrew; Hankemeier, Thomas; Murphy, James; Vreeken, Rob J.; Langridge, James; Kang, Jing X.
2014-01-01
A balanced omega-6/omega-3 polyunsaturated fatty acid (PUFA) ratio has been linked to health benefits and the prevention of many chronic diseases. Current dietary intervention studies with different sources of omega-3 fatty acids (omega-3) lack appropriate control diets and carry many other confounding factors derived from genetic and environmental variability. In our study, we used the fat-1 transgenic mouse model as a proxy for long-term omega-3 supplementation to determine, in a well-controlled manner, the molecular phenotype associated with a balanced omega-6/omega-3 ratio. The fat-1 mouse can convert omega-6 to omega-3 PUFAs, which protect against a wide variety of diseases including chronic inflammatory diseases and cancer. Both wild-type (WT) and fat-1 mice were subjected to an identical diet containing 10% corn oil, which has a high omega-6 content similar to that of the Western diet, for a six-month duration. We used a multi-platform lipidomic approach to compare the plasma lipidome between fat-1 and WT mice. In fat-1 mice, an unbiased profiling showed a significant increase in the levels of unesterified eicosapentaenoic acid (EPA), EPA-containing cholesteryl ester, and omega-3 lysophosphospholipids. The increase in omega-3 lipids is accompanied by a significant reduction in omega-6 unesterified docosapentaenoic acid (omega-6 DPA) and DPA-containing cholesteryl ester as well as omega-6 phospholipids and triacylglycerides. Targeted lipidomics profiling highlighted a remarkable increase in EPA-derived diols and epoxides formed via the cytochrome P450 (CYP450) pathway in the plasma of fat-1 mice compared with WT mice. Integration of the results of untargeted and targeted analyses has identified a lipidomic biosignature that may underlie the healthful phenotype associated with a balanced omega-6/omega-3 ratio, and can potentially be used as a circulating biomarker for monitoring the health status and the efficacy of omega-3 intervention in humans. PMID
16. Theory of hydro-equivalent ignition for inertial fusion and its applications to OMEGA and the National Ignition Facility
SciTech Connect
Nora, R.; Betti, R.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Meyerhofer, D. D.; McCrory, R. L.
2014-05-15
The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements for cryogenic implosion experiments on the Omega Laser Facility. The theory of hydrodynamic similarity is developed in both one and two dimensions and tested using multimode hydrodynamic simulations with the hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] of hydro-equivalent implosions (implosions with the same implosion velocity, adiabat, and laser intensity). The theory is used to scale the performance of direct-drive OMEGA implosions to the National Ignition Facility (NIF) energy scales and determine the requirements for demonstrating hydro-equivalent ignition on OMEGA. Hydro-equivalent ignition on OMEGA is represented by a cryogenic implosion that would scale to ignition on the NIF at 1.8 MJ of laser energy symmetrically illuminating the target. It is found that a reasonable combination of neutron yield and areal density for OMEGA hydro-equivalent ignition is 3 to 6 × 10{sup 13} and ∼0.3 g/cm{sup 2}, respectively, depending on the level of laser imprinting. This performance has not yet been achieved on OMEGA.
17. Theory of hydro-equivalent ignition for inertial fusion and its applications to OMEGA and the National Ignition Facilitya)
Nora, R.; Betti, R.; Anderson, K. S.; Shvydky, A.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Marozas, J. A.; Collins, T. J. B.; Radha, P. B.; Hu, S. X.; Epstein, R.; Marshall, F. J.; McCrory, R. L.; Sangster, T. C.; Meyerhofer, D. D.
2014-05-01
The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements for cryogenic implosion experiments on the Omega Laser Facility. The theory of hydrodynamic similarity is developed in both one and two dimensions and tested using multimode hydrodynamic simulations with the hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] of hydro-equivalent implosions (implosions with the same implosion velocity, adiabat, and laser intensity). The theory is used to scale the performance of direct-drive OMEGA implosions to the National Ignition Facility (NIF) energy scales and determine the requirements for demonstrating hydro-equivalent ignition on OMEGA. Hydro-equivalent ignition on OMEGA is represented by a cryogenic implosion that would scale to ignition on the NIF at 1.8 MJ of laser energy symmetrically illuminating the target. It is found that a reasonable combination of neutron yield and areal density for OMEGA hydro-equivalent ignition is 3 to 6 × 1013 and ˜0.3 g/cm2, respectively, depending on the level of laser imprinting. This performance has not yet been achieved on OMEGA.
18. Motion perception: from phi to omega.
PubMed Central
Rose, D; Blake, R
1998-01-01
When human observers view dynamic random noise, such as television 'snow', through a curved or annular aperture, they experience a compelling illusion that the noise is moving smoothly and coherently around the curve (the 'omega effect'). In several series of experiments, we have investigated the conditions under which this effect occurs and the possible mechanisms that might cause it. We contrast the omega effect with 'phi motion', seen when an object suddenly changes position. Our conclusions are that the visual scene is first segmented into objects before a coherent velocity is assigned to the texture on each object's surface. The omega effect arises because there are motion mechanisms that deal specifically with object rotation and these interact with pattern mechanisms sensitive to curvature. PMID:9684292
19. OMEGA Observations of Mars Analogue Rocks
NASA Technical Reports Server (NTRS)
Bonello, G.; Bibring, J. P.; Morris, R. V.; Mustard, J. F.
2003-01-01
In the last 20 years, imaging spectrometry in the visible and near infrared onboard spacecraft has become an essential technique to study surfaces and atmospheres of planetary objects, prior and in addition to in-situ analyses. Remote sensing experiments analyzing the sunlight reflected by planetary surfaces can be used to derive the mineralogical composition and physical properties of the natural surfaces and atmospheres observed. This technique was successfully used on Mars with ISM instrument. As an improvement of ISM, OMEGA onboard MARS-EXPRESS will play a key role in the mineralogical mapping of the Martian surface. We present the reflectance measurements made with OMEGA during on ground calibration sessions on natural slabs of rocks and minerals part of a database which will be used on similar future American instruments (as CRISM onboard MRO). We discuss the implication on the scientific capabilities of OMEGA instrument.
20. Dietary omega-3 and omega-6 fatty acids compete in producing tissue compositions and tissue responses.
PubMed
Lands, Bill
2014-11-01
Serious food-related health disorders may be prevented by recognizing the molecular processes that connect the dietary intake of vitamin-like fatty acids to tissue accumulation of precursors of potent hormone-like compounds that cause harmful tissue responses. Conversion of dietary 18-carbon omega-3 and omega-6 polyunsaturated fatty acids to tissue 20- and 22-carbon highly unsaturated fatty acids (HUFAs) is catalyzed by promiscuous enzymes that allow different types of fatty acid to compete among each other for accumulation in tissue HUFA. As a result, food choices strongly influence the types of accumulated tissue HUFA. However, the conversion of tissue HUFA to active hormones and their receptor-mediated actions occurs with discriminating enzymes and receptors that give more intense responses for the omega-6 and omega-3 hormones. Undesired chronic health disorders, which are made worse by excessive omega-6 hormone actions, can be prevented by eating more omega-3 fats, less omega-6 fats, and fewer calories per meal.
1. Effects of Diets Enriched in Omega-9 or Omega-6 Fatty Acids on Reproductive Process
PubMed Central
Mousavi, Seyedeh Neda; Koohdani, Fariba; Shidfar, Farzad; Shafiei-Neek, Leila
2016-01-01
Objective: Maternal type and amounts of dietary fatty acids affect on reproductive process in the mice. The present study investigated the effects of maternal supplementation with different amounts of omega-6 or omega-9 during pregnancy on the number of offspring, sex-ratio and duration of gestation. Materials and methods: Eight-week-old female C57BL/6 mice were randomly assigned into four dietary groups including low omega-6 (16%; LO6), low omega-9 (16%; LO9), high omega-6 (45%; HO6) and high omega-9 (45%; HO9) during gestation. Number of offspring, sex-ratio and duration of pregnancy were compared among four dietary groups. Results: There was significant difference between LO6 and HO6 (p < 0.0001), LO9 and HO9 (p < 0.0001) groups in total number of pups. The number of female and male offspring were significantly different between LO6 and LO9 (p = 0.009 and p = 0.001, respectively), LO9 and HO9 (p = 0.01 and p = 0.025) groups. Duration of pregnancy was significantly higher in low fat diet than high fat diet groups (< 0.001). Conclusion: High fat diet reduced number of pups, gestation duration and lead to early labor. Omega-9 fatty acids shifted sex of offspring to females. PMID:27648098
2. High-yield bang time detector for the OMEGA laser
Glebov, V. Yu.; Stoeckl, C.; Sangster, T. C.; Mileham, C.; Roberts, S.; Lerche, R. A.
2006-10-01
A simple, low-cost, high-yield neutron bang time (HYNBT) detector has been developed and implemented on the 60-beam, 30kJ OMEGA Laser Facility at the University of Rochester's Laboratory for Laser Energetics. The HYNBT consists of three chemical-vapor deposition diamond detectors of different sizes and sensitivities placed in a lead-shielded housing. The HYNBT is located in a reentrant tube 50cm from the center of the target chamber. The HYNBT has been temporally cross calibrated against the streak-camera-based neutron temporal diagnostic (NTD) for both D2 and DT implosions. The HYNBT has an internal time resolution better than 20ps and is able to measure bang time for yields above 1010 for DT and 5×1010 for D2 implosions. The implementation of the HYNBT on the National Ignition Facility will be discussed.
3. First evaluation of the thermodynamic properties for spheres to elongated micelles transition of some propanediyl-alpha,omega-bis(dimethylalkylammonium bromide) surfactants in aqueous solution.
PubMed
Fisicaro, Emilia; Compari, Carlotta; Duce, Elenia; Contestabili, Cristina; Viscardi, Guido; Quagliotto, Pierluigi
2005-02-10
The apparent and partial molar enthalpies, apparent molar volumes, and adiabatic compressibilities at 298 K of the aqueous solutions of the cationic gemini surfactants propanediyl-alpha,omega-bis(octyldimethylammonium bromide) (8-3-8) and propanediyl-alpha,omega-bis(dodecyldimethylammonium bromide) (12-3-12) have been measured as a function of concentration. The trends of the partial molar enthalpies versus concentration are the first well documented thermodynamic evidence of sphere to rod transition in the micellar phase, involving a detectable quantity of heat, and allow the determination of the change in enthalpy associated with this transition. The changes in enthalpies upon micellization and for the sphere to elongated micelles transition, DeltaH(s)(-->)(r), have been obtained from the experimental data by using a pseudo-phase transition approach: -1.5 kJ mol(-1) for 8-3-8 and -3.9 kJ mol(-1) for 12-3-12. No evidence of the above transition is found in the trends of volumetric properties versus m. The apparent adiabatic molar compressibilities for the compounds under investigation are also reported here for the first time: a negative group contribution for the methylene group is evaluated, when the surfactants are present in solution as a single molecule, reflecting its solvation structure. In the micellar phase, the -CH(2)- group contribution becomes positive. A value of 1.17 x 10(-3) cm(3) bar(-1) mol(-1) for the change in adiabatic molar compressibility upon micellization is obtained. The lower values of the methylene group contributions to the volumetric properties for the monomers support the hypothesis of partial association of the chains before the cmc.
4. Dual-shank attachment design for omega seals
DOEpatents
Sattinger, Stanley S.
1978-01-01
An improved apparatus and process for attaching welded omega seal segments to reactor heads, standpipes, mechanisms, and plugs comprises a first shank in combination with a second shank to attach an omega seal at a metal-to-metal interface.
5. Measurement of the spin of the omega(-) hyperon.
PubMed
2006-09-15
A measurement of the spin of the Omega(-) hyperon produced through the exclusive process Xi(c)(0)-->Omega(-)K(+) is presented using a total integrated luminosity of 116 fb(-1) recorded with the BABAR detector at the e(+)e(-) asymmetric-energy B factory at SLAC. Under the assumption that the Xi(c)(0) has spin 1/2, the angular distribution of the Lambda from Omega(-)-->LambdaK(-) decay is inconsistent with all half-integer Omega(-) spin values other than 3/2. Lower statistics data for the process Omega(c)(0)-->Omega(-)pi(+) from a 230 fb(-1) sample are also found to be consistent with Omega(-) spin 3/2. If the Xi(c)(0) spin were 3/2, an Omega(-) spin of 5/2 could not be excluded.
6. Flight evaluation: Ohio University omega receiver base
NASA Technical Reports Server (NTRS)
Chamberlin, K. A.; Lilley, R. W.; Salter, R. J.
1974-01-01
A flight evaluation is presented of the Ohio University Omega Receiver Base, developed under the NASA Tri-University Program in Air Transportation, to provide a vehicle for the transfer of flight-test data to NASA and to other participants in the Tri-University program. Chart recordings of flight data are given, along with chronological listings of significant events which occurred during the flight. Digital data was prepared in data-processing card form for distribution. Data include phase measurements from all eight Omega time-slots for the duration of the flight, plus event marks which serve to correlate the phase data with flight-path documentation.
7. Hierarchical Analysis of the Omega Ontology
SciTech Connect
Joslyn, Cliff A.; Paulson, Patrick R.
2009-12-01
Initial delivery for mathematical analysis of the Omega Ontology. We provide an analysis of the hierarchical structure of a version of the Omega Ontology currently in use within the US Government. After providing an initial statistical analysis of the distribution of all link types in the ontology, we then provide a detailed order theoretical analysis of each of the four main hierarchical links present. This order theoretical analysis includes the distribution of components and their properties, their parent/child and multiple inheritance structure, and the distribution of their vertical ranks.
Kuijken, K.
2011-12-01
OmegaCAM, the 300-megapixel wide-field optical camera on the new VLT Survey Telescope (VST), was commissioned between March and August of this year. This new capability in ESO's arsenal takes images of 1 degree by 1° patches of the sky, at 0.2 arcseconds per pixel resolution and of image quality well-matched to the natural seeing on Paranal. The commissioning and OmegaCAM's scientific niche as a high image quality, ultra-violet- sensitive wide-field survey instrument are briefly discussed.
9. Omega 3 fatty acids and the eye.
PubMed
Cakiner-Egilmez, Tulay
2008-01-01
The health benefits of fish oil have been known for decades. Most of the health benefits of fish oil can be attributed to the presence of omega-3 essential fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Clinical studies have suggested that DHA and EPA lower triglycerides; slow the buildup of atherosclerotic plaques; lower blood pressure slightly; as well as reduce the risk of death, heart attack, and arrhythmias. Studies have also shown that omega-3 fatty acids may slow the progression of vision loss from AMD and reverse the signs of dry eye syndrome.
10. [Antioxidant activity of vegetable oils with various omega-6/omega-3 fatty acids ratio].
PubMed
Guseva, D A; Prozorovskaia, N N; Shironin, A V; Sanzhakov, M A; Evteeva, N M; Rusina, I F; Kasaikina, O T
2010-01-01
Antioxidant activity and the oxidative stability were investigated in flax, sesame, silybum oils and oils with different omega-6/omega-3 fatty acid ratio. The content of antioxidants (AO) in crude oils and their reactivity towards peroxyl radicals were studied using kinetic method for addition of oil in a model reaction of cumol oxidation. There were correlations between PUFA/omega-9 and thermal stability (50 degrees C); between gamma-tocopherol content and resistantance to oxidative changes after storage at (10 +/- 2) degrees C for 6 months.
11. Gas-Phase Oxidation of Cm+ and Cm2+ -- Thermodynamics of neutral and ionized CmO
SciTech Connect
Gibson, John K; Haire, Richard G.; Santos, Marta; Pires de Matos, Antonio; Marcalo, Joaquim
2008-12-08
Fourier transform ion cyclotron resonance mass spectrometry was employed to study the products and kinetics of gas-phase reactions of Cm+ and Cm2+; parallel studies were carried out with La+/2+, Gd+/2+ and Lu+/2+. Reactions with oxygen-donor molecules provided estimates for the bond dissociation energies, D[M+-O](M = Cm, Gd, Lu). The first ionization energy, IE[CmO], was obtained from the reactivity of CmO+ with dienes, and the second ionization energies, IE[MO+](M = Cm, La, Gd, Lu), from the rates of electron-transfer reactions from neutrals to the MO2+ ions. The following thermodynamic quantities for curium oxide molecules were obtained: IE[CmO]= 6.4+-0.2 eV; IE[CmO+]= 15.8+-0.4 eV; D[Cm-O]= 710+-45 kJ mol-1; D[Cm+-O]= 670+-40 kJ mol-1; and D[Cm2+-O]= 342+-55 kJ mol-1. Estimates for the M2+-O bond energies for M = Cm, La, Gd and Lu are all intermediate between D[N2-O]and D[OC-O]--i.e., 167 kJ mol-1< D[M2+-O]< 532 kJ mol-1 -- such that the four MO2+ ions fulfill the thermodynamic requirement for catalytic O-atom transport from N2O to CO. It was demonstrated that the kinetics are also favorable and that the CmO2+, LaO2+, GdO2+ and LuO2+ dipositive ions each catalyze the gas-phase oxidation of CO to CO2 by N2O. The CmO2+ ion appeared during the reaction of Cm+ with O2 when the intermediate, CmO+, was not collisionally cooled -- although its formation is kinetically and/or thermodynamically unfavorable, CmO2+ is a stable species.
12. Baryon spectroscopy and the omega minus
SciTech Connect
Samios, N.P.
1994-12-31
In this report, I will mainly discuss baryon resonances with emphasis on the discovery of the {Omega}{sup {minus}}. However, for completeness, I will also present some data on the meson resonances which together with the baryons led to the uncovering of the SU(3) symmetry of particles and ultimately to the concept of quarks.
13. Coefficient Omega Bootstrap Confidence Intervals: Nonnormal Distributions
ERIC Educational Resources Information Center
2013-01-01
The performance of the normal theory bootstrap (NTB), the percentile bootstrap (PB), and the bias-corrected and accelerated (BCa) bootstrap confidence intervals (CIs) for coefficient omega was assessed through a Monte Carlo simulation under conditions not previously investigated. Of particular interests were nonnormal Likert-type and binary items.…
14. Omega-3 Index and Cardiovascular Health
PubMed Central
von Schacky, Clemens
2014-01-01
Recent large trials with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the cardiovascular field did not demonstrate a beneficial effect in terms of reductions of clinical endpoints like total mortality, sudden cardiac arrest or other major adverse cardiac events. Pertinent guidelines do not uniformly recommend EPA + DHA for cardiac patients. In contrast, in epidemiologic findings, higher blood levels of EPA + DHA were consistently associated with a lower risk for the endpoints mentioned. Because of low biological and analytical variability, a standardized analytical procedure, a large database and for other reasons, blood levels of EPA + DHA are frequently assessed in erythrocytes, using the HS-Omega-3 Index® methodology. A low Omega-3 Index fulfills the current criteria for a novel cardiovascular risk factor. Neutral results of intervention trials can be explained by issues of bioavailability and trial design that surfaced after the trials were initiated. In the future, incorporating the Omega-3 Index into trial designs by recruiting participants with a low Omega-3 Index and treating them within a pre-specified target range (e.g., 8%–11%), will make more efficient trials possible and provide clearer answers to the questions asked than previously possible. PMID:24566438
15. Omega-3 Fatty Acids in the Management of Epilepsy.
PubMed
Tejada, Silvia; Martorell, Miquel; Capó, Xavier; Tur, Josep A; Pons, Antoni; Sureda, Antoni
2016-01-01
Omega-3 and omega-6 fatty acids are polyunsaturated fatty acids (PUFAs) with multiple double bonds. Linolenic and alpha-linolenic acids are omega-6 and omega-3 PUFAs, precursors for the synthesis of long-chain PUFAs (LC-PUFAs), such as arachidonic acid (omega-6 PUFA), and eicosapentaenoic and docosahexaenoic acids (omega-3 PUFAs). The three most important omega-3 fatty acids are alpha-linolenic, eicosapentaenoic and docosahexaenoic acids, which cannot be synthesized in enough amounts by the body, and therefore they must be supplied by the diet. Omega-3 fatty acids are essential for the correct functioning of the organism and participate in many physiological processes in the brain. Epilepsy is a common and heterogeneous chronic brain disorder characterized by recurrent epileptic seizures leading to neuropsychiatric disabilities. The prevalence of epilepsy is high achieving about 1% of the general population. There is evidence suggesting that omega-3 fatty acids may have neuroprotective and anticonvulsant effects and, accordingly, may have a potential use in the treatment of epilepsy. In the present review, the potential use of omega-3 fatty acids in the treatment of epilepsy, and the possible proposed mechanisms of action are discussed. The present article summarizes the recent knowledge of the potential protective role of dietary omega-3 fatty acids in epilepsy.
16. Rapid induction of omega-3 fatty acids (EPA) in Nannochloropsis sp. by UV-C radiation.
PubMed
Sharma, Kalpesh; Schenk, Peer M
2015-06-01
Omega-3 fatty acids, such as eicosapentaenoic acid (EPA), provide substantial health benefits. As global fish stocks are declining and in some cases are contaminated with heavy metals, there is a need to find more sustainable land-based sources of these essential fatty acids. The oleaginous microalga Nannochloropsis sp. has been identified as a highly efficient producer of omega-3 fatty acids. In this study, we present a new process to rapidly induce biosynthesis of essential fatty acids, including EPA in Nannochloropsis sp. BR2. Short exposure to UV-C at a dose of 100 or 250 mJ/cm(2) led to a significant increase in total cellular lipid contents when compared to mock-treated controls. A low dosage of 100 mJ/cm(2) also led to a twofold increase in total EPA content within 24 h that constituted 30% of total fatty acids and up to 12% of total dry weight at higher dosages. UV-C radiation may find uses as an easily applicable external inducer for large-scale production of omega-3 production from microalgae.
17. A host-microbiome interaction mediates the opposing effects of omega-6 and omega-3 fatty acids on metabolic endotoxemia.
PubMed
Kaliannan, Kanakaraju; Wang, Bin; Li, Xiang-Yong; Kim, Kui-Jin; Kang, Jing X
2015-06-11
Metabolic endotoxemia, commonly derived from gut dysbiosis, is a primary cause of chronic low grade inflammation that underlies many chronic diseases. Here we show that mice fed a diet high in omega-6 fatty acids exhibit higher levels of metabolic endotoxemia and systemic low-grade inflammation, while transgenic conversion of tissue omega-6 to omega-3 fatty acids dramatically reduces endotoxemic and inflammatory status. These opposing effects of tissue omega-6 and omega-3 fatty acids can be eliminated by antibiotic treatment and animal co-housing, suggesting the involvement of the gut microbiota. Analysis of gut microbiota and fecal transfer revealed that elevated tissue omega-3 fatty acids enhance intestinal production and secretion of intestinal alkaline phosphatase (IAP), which induces changes in the gut bacteria composition resulting in decreased lipopolysaccharide production and gut permeability, and ultimately, reduced metabolic endotoxemia and inflammation. Our findings uncover an interaction between host tissue fatty acid composition and gut microbiota as a novel mechanism for the anti-inflammatory effect of omega-3 fatty acids. Given the excess of omega-6 and deficiency of omega-3 in the modern Western diet, the differential effects of tissue omega-6 and omega-3 fatty acids on gut microbiota and metabolic endotoxemia provide insight into the etiology and management of today's health epidemics.
18. New insights into the health effects of dietary saturated and omega-6 and omega-3 polyunsaturated fatty acids
PubMed Central
2012-01-01
Cardiovascular diseases and cancers are leading causes of morbidity and mortality. Reducing dietary saturated fat and replacing it with polyunsaturated fat is still the main dietary strategy to prevent cardiovascular diseases, although major flaws have been reported in the analyses supporting this approach. Recent studies introducing the concept of myocardial preconditioning have opened new avenues to understand the complex interplay between the various lipids and the risk of cardiovascular diseases. The optimal dietary fat profile includes a low intake of both saturated and omega-6 fatty acids and a moderate intake of omega-3 fatty acids. This profile is quite similar to the Mediterranean diet. On the other hand, recent studies have found a positive association between omega-6 and breast cancer risk. In contrast, omega-3 fatty acids do have anticancer properties. It has been shown that certain (Mediterranean) polyphenols significantly increase the endogenous synthesis of omega-3 whereas high intake of omega-6 decreases it. Finally, epidemiological studies suggest that a high omega-3 to omega-6 ratio may be the optimal strategy to decrease breast cancer risk. Thus, the present high intake of omega-6 in many countries is definitely not the optimal strategy to prevent cardiovascular disease and cancers. A moderate intake of plant and marine omega-3 in the context of the traditional Mediterranean diet (low in saturated and omega-6 fatty acids but high in plant monounsaturated fat) appears to be the best approach to reduce the risk of both cardiovascular diseases and cancers, in particular breast cancer. PMID:22613931
19. Parallel processing: The Cm/sup */ experience
SciTech Connect
Siewiorek, D.; Gehringer, E.; Segall, Z.
1986-01-01
This book describes the parallel-processing research with CM/sup */ at Carnegie-Mellon University. Cm/sup */ is a tightly coupled 50-processor multiprocessing system that has been in operation since 1977. Two complete operating systems-StarOS and Medusa-are part of its development along with a number of applications.
20. A high-resolving-power x-ray spectrometer for the OMEGA EP Laser (invited)
Nilson, P. M.; Ehrne, F.; Mileham, C.; Mastrosimone, D.; Jungquist, R. K.; Taylor, C.; Stillman, C. R.; Ivancic, S. T.; Boni, R.; Hassett, J.; Lonobile, D. J.; Kidder, R. W.; Shoup, M. J.; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Froula, D. H.; Hill, K. W.; Gao, L.; Bitter, M.; Efthimion, P.; Meyerhofer, D. D.
2016-11-01
A high-resolving-power x-ray spectrometer has been developed for the OMEGA EP Laser System based on a spherically bent Si [220] crystal with a radius of curvature of 330 mm and a Spectral Instruments (SI) 800 Series charge-coupled device. The instrument measures time-integrated x-ray emission spectra in the 7.97- to 8.11-keV range, centered on the Cu Kα1 line. To demonstrate the performance of the spectrometer under high-power conditions, Kα1,2 emission spectra were measured from Cu foils irradiated by the OMEGA EP laser with 100-J, 1-ps pulses at focused intensities above 1018 W/cm2. The ultimate goal is to couple the spectrometer to a picosecond x-ray streak camera and measure temperature-equilibration dynamics inside rapidly heated materials. The plan for these ultrafast streaked x-ray spectroscopy studies is discussed.
1. A high-resolving-power x-ray spectrometer for the OMEGA EP Laser (invited).
PubMed
Nilson, P M; Ehrne, F; Mileham, C; Mastrosimone, D; Jungquist, R K; Taylor, C; Stillman, C R; Ivancic, S T; Boni, R; Hassett, J; Lonobile, D J; Kidder, R W; Shoup, M J; Solodov, A A; Stoeckl, C; Theobald, W; Froula, D H; Hill, K W; Gao, L; Bitter, M; Efthimion, P; Meyerhofer, D D
2016-11-01
A high-resolving-power x-ray spectrometer has been developed for the OMEGA EP Laser System based on a spherically bent Si [220] crystal with a radius of curvature of 330 mm and a Spectral Instruments (SI) 800 Series charge-coupled device. The instrument measures time-integrated x-ray emission spectra in the 7.97- to 8.11-keV range, centered on the Cu Kα1 line. To demonstrate the performance of the spectrometer under high-power conditions, Kα1,2 emission spectra were measured from Cu foils irradiated by the OMEGA EP laser with 100-J, 1-ps pulses at focused intensities above 10(18) W/cm(2). The ultimate goal is to couple the spectrometer to a picosecond x-ray streak camera and measure temperature-equilibration dynamics inside rapidly heated materials. The plan for these ultrafast streaked x-ray spectroscopy studies is discussed.
2. OMEGA navigation system status and future plans
NASA Technical Reports Server (NTRS)
Nolan, T. P.; Scull, D. C.
1974-01-01
OMEGA is described as a very low frequency (VLF) radio navigational system operating in the internationally allocated navigation band in the electromagentic spectrum between 10 and 14 kilohertz. Full system implementation with worldwide coverage from eight transmitting stations is planned for the latter 1970's. Experimental stations have operated since 1966 in support of system evaluation and test. These stations provided coverage over most of the North Atlantic, North American Continent, and eastern portions of the North Pacific. This coverage provided the fundamental basis for further development of the system and has been essential to the demonstrated feasibility of the one to two nautical mile root-mean-square system accuracy. OMEGA is available to users in all nations, both on ships and in aircraft.
3. Cardioprotective mechanism of omega-3 polyunsaturated fatty acids.
PubMed
Endo, Jin; Arita, Makoto
2016-01-01
Omega-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid and docosahexaenoic acid, are widely regarded as cardioprotective. Several large-scale, randomized clinical trials have shown that dietary intake of omega-3 PUFAs improves the prognosis of patients with symptomatic heart failure or recent myocardial infarction. Therefore, dietary consumption of omega-3 PUFA is recommended in international guidelines for the general population to prevent the occurrence of cardiovascular diseases (CVDs). However, the precise mechanisms underlying the cardioprotective effects of omega-3 PUFAs are not fully understood. Omega-3 PUFAs can be incorporated into the phospholipid bilayer of cell membranes and can affect membrane fluidity, lipid microdomain formation, and signaling across membranes. Omega-3 PUFAs also modulate the function of membrane ion channels, such as Na and L-type Ca channels, to prevent lethal arrhythmias. Moreover, omega-3 PUFAs also prevent the conversion of arachidonic acid into pro-inflammatory eicosanoids by serving as an alternative substrate for cyclooxygenase or lipoxygenase, resulting in the production of less potent products. In addition, a number of enzymatically oxygenated metabolites derived from omega-3 PUFAs were recently identified as anti-inflammatory mediators. These omega-3 metabolites may contribute to the beneficial effects against CVDs that are attributed to omega-3 PUFAs.
4. OMEGA FY13 HED requests - LANL
SciTech Connect
Workman, Jonathan B; Loomis, Eric N
2012-06-25
This is a summary of scientific work to be performed on the OMEGA laser system located at the Laboratory for Laser Energetics in Rochester New York. The work is funded through Science and ICF Campagins and falls under the category of laser-driven High-Energy Density Physics experiments. This summary is presented to the Rochester scheduling committee on an annual basis for scheduling and planning purposes.
5. Semileptonic Decays of Heavy Omega Baryons in a Quark Model
SciTech Connect
Muslema Pervin; Winston Roberts; Simon Capstick
2006-03-24
The semileptonic decays of {Omega}{sub c} and {Omega}{sub b} are treated in the framework of a constituent quark model developed in a previous paper on the semileptonic decays of heavy {Lambda} baryons. Analytic results for the form factors for the decays to ground states and a number of excited states are evaluated. For {Omega}{sub b} to {Omega}{sub c} the form factors obtained are shown to satisfy the relations predicted at leading order in the heavy-quark effective theory at the non-recoil point. A modified fit of nonrelativistic and semirelativistic Hamiltonians generates configuration-mixed baryon wave functions from the known masses and the measured {Lambda}{sub c}{sup +} {yields} {Lambda}e{sup +}{nu} rate, with wave functions expanded in both harmonic oscillator and Sturmian bases. Decay rates of {Omega}{sub b} to pairs of ground and excited {Omega}{sub c} states related by heavy-quark symmetry calculated using these configuration-mixed wave functions are in the ratios expected from heavy-quark effective theory, to a good approximation. Our predictions for the semileptonic elastic branching fraction of {Omega}{sub Q} vary minimally within the models we use. We obtain an average value of (84 {+-} 2%) for the fraction of {Omega}{sub c} {yields} {Xi}{sup (*)} decays to ground states, and 91% for the fraction of {Omega}{sub c} {yields} {Omega}{sup (*)} decays to the ground state {Omega}. The elastic fraction of {Omega}{sub b} {yields} {Omega}{sub c} ranges from about 50% calculated with the two harmonic-oscillator models, to about 67% calculated with the two Sturmian models.
6. Simulations of Fuel Assembly and Fast-Electron Transport in Integrated Fast-Ignition Experiments on OMEGA
Solodov, A. A.; Theobald, W.; Anderson, K. S.; Shvydky, A.; Epstein, R.; Betti, R.; Myatt, J. F.; Stoeckl, C.; Jarrott, L. C.; McGuffey, C.; Qiao, B.; Beg, F. N.; Wei, M. S.; Stephens, R. B.
2013-10-01
Integrated fast-ignition experiments on OMEGA benefit from improved performance of the OMEGA EP laser, including higher contrast, higher energy, and a smaller focus. Recent 8-keV, Cu-Kα flash radiography of cone-in-shell implosions and cone-tip breakout measurements showed good agreement with the 2-D radiation-hydrodynamic simulations using the code DRACO. DRACO simulations show that the fuel assembly can be further improved by optimizing the compression laser pulse, evacuating air from the shell, and by adjusting the material of the cone tip. This is found to delay the cone-tip breakout by ~220 ps and increase the core areal density from ~80 mg/cm2 in the current experiments to ~500 mg/cm2 at the time of the OMEGA EP beam arrival before the cone-tip breakout. Simulations using the code LSP of fast-electron transport in the recent integrated OMEGA experiments with Cu-doped shells will be presented. Cu-doping is added to probe the transport of fast electrons via their induced Cu K-shell fluorescent emission. This material is based upon work supported by the Department of Energy National Nuclear Security Administration DE-NA0001944 and the Office of Science under DE-FC02-04ER54789.
7. Omega-6 and omega-3 fatty acids predict accelerated decline of peripheral nerve function in older persons
PubMed Central
Lauretani, F.; Bandinelli, S.; Benedetta, B.; Cherubini, A.; Iorio, A. D.; Blè, A.; Giacomini, V.; Corsi, A. M.; Guralnik, J. M.; Ferrucci, L.
2009-01-01
Pre-clinical studies suggest that both omega-6 and omega-3 fatty acids have beneficial effects on peripheral nerve function. Rats feed a diet rich in polyunsaturated fatty acids (PUFAs) showed modification of phospholipid fatty acid composition in nerve membranes and improvement of sciatic nerve conduction velocity (NCV). We tested the hypothesis that baseline plasma omega-6 and omega-3 fatty acids levels predict accelerated decline of peripheral nerve function. Changes between baseline and the 3-year follow-up in peripheral nerve function was assessed by standard surface ENG of the right peroneal nerve in 384 male and 443 female participants of the InCHIANTI study (age range: 24–97 years). Plasma concentrations of selected fatty acids assessed at baseline by gas chromatography. Independent of confounders, plasma omega-6 fatty acids and linoleic acid were significantly correlated with peroneal NCV at enrollment. Lower plasma PUFA, omega-6 fatty acids, linoleic acid, ratio omega-6/omega-3, arachidonic acid and docosahexanoic acid levels were significantly predicted a steeper decline in nerve function parameters over the 3-year follow-up. Low plasma omega-6 and omega-3 fatty acids levels were associated with accelerated decline of peripheral nerve function with aging. PMID:17594339
8. Omega Centauri Looks Radiant in Infrared
NASA Technical Reports Server (NTRS)
2008-01-01
[figure removed for brevity, see original site] Poster Version
A cluster brimming with millions of stars glistens like an iridescent opal in this image from NASA's Spitzer Space Telescope. Called Omega Centauri, the sparkling orb of stars is like a miniature galaxy. It is the biggest and brightest of the 150 or so similar objects, called globular clusters, that orbit around the outside of our Milky Way galaxy. Stargazers at southern latitudes can spot the stellar gem with the naked eye in the constellation Centaurus.
Globular clusters are some of the oldest objects in our universe. Their stars are over 12 billion years old, and, in most cases, formed all at once when the universe was just a toddler. Omega Centauri is unusual in that its stars are of different ages and possess varying levels of metals, or elements heavier than boron. Astronomers say this points to a different origin for Omega Centauri than other globular clusters: they think it might be the core of a dwarf galaxy that was ripped apart and absorbed by our Milky Way long ago.
In this new view of Omega Centauri, Spitzer's infrared observations have been combined with visible-light data from the National Science Foundation's Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile. Visible-light data with a wavelength of .55 microns is colored blue, 3.6-micron infrared light captured by Spitzer's infrared array camera is colored green and 24-micron infrared light taken by Spitzer's multiband imaging photometer is colored red.
Where green and red overlap, the color yellow appears. Thus, the yellow and red dots are stars revealed by Spitzer. These stars, called red giants, are more evolved, larger and dustier. The stars that appear blue were spotted in both visible and 3.6-micron-, or near-, infrared light. They are less evolved, like our own sun. Some of the red spots in the picture are distant galaxies beyond our own.
Spitzer found very little dust
9. OMEGA - an operational glacier monitoring system
Pellikka, P. K. E.
2003-04-01
Glacier changes reflect local climate changes and are one of the most important direct indicators of global climate change. In general, the glaciers are retreating in Europe, but some glaciers are advancing. However, even in small areas glacier responses can be different. The application of glaciers as indicators requires sufficient amount of glaciers, which is possible only with remote sensing methods. Remote sensing data have been used for glacier monitoring from the late 19th century, first as terrestrial photographs, but later as aerial photographs. A new era began in the 1970’s as optical satellite data became available. Since late 1990’s the glacier monitoring could be performed with numerous satellite and airborne sensors ranging from satellite radar data to airborne laser scanner data. All together, the development of new remote sensing technologies and methods provides many possibilities for studies of glacier features and parameters. The glacier parameters of interest in operational monitoring are the changes of glacier area and volume, and the variation of glacier zones, such as snow, firn and ice. These parameters enable the estimation of relative volume change, AAR and equilibrium line, for example. Operational monitoring involves that the remote sensing data to be used is available continuously, the image processing methods are accurate and the processing chain is developed so that the derivation of the aimed parameters works fluently. The OMEGA project aims at the development of an operational glacier monitoring system applying all the potential remote sensing data. The objectives are to develop workflows and semi-automatic image processing methodologies for different data types in order to retrieve glacier parameters, to construct databases of the study glaciers and to develop the prototype of an operational monitoring system. The test glaciers are Hintereisferner in Austria and Engabreen in Norway. The deliverable of the project is the OMEGA
10. Dietary Omega-3 Fatty Acid, Ratio of Omega-6 to Omega-3 Intake, Inflammation, and Survival in Long-term Hemodialysis Patients
PubMed Central
Noori, Nazanin; Dukkipati, Ramanath; Kovesdy, Csaba P.; Sim, John J.; Feroze, Usama; Murali, Sameer B.; Bross, Rachelle; Benner, Debbie; Kopple, Joel D; Kalantar-Zadeh, Kamyar
2011-01-01
Background Mortality among long-term hemodialysis patients is high, mostly attributed to cardiovascular events, and may be related to chronic inflammation. We hypothesized that the anti-inflammatory benefits of higher dietary omega-3, compared to omega-6, poly-unsaturated fatty acids may modulate the inflammatory processes and reduce death risk. Study design Prospective cohort study using linear and Cox proportional regressions. Setting and Participants 145 hemodialysis patients from 8 DaVita dialysis clinics in Southern California during 2001-2007 Predictors Intake of dietary omega-3 and ratio of omega-6 to omega-3 using 3-day food record supplemented by dietary interview. Outcomes One-year change in serum C-reactive protein (CRP) and 6-year survival. Results Patients were 53±14 years old (mean±SD) and included 43% women and 42% African-Americans. Median (25th-75 percentile) of dietary omega-3 intake, ratio of omega-6 to omega-3 intake, baseline serum CRP, and change in CRP over one year were 1.1(0.8-1.6) g/day, 9.3(7.6-11.3), 3.1(0.8-6.8) mg/L, and +0.2(−0.4 to +0.8) mg/L, respectively. In regression models adjusted for case-mix, dietary calorie and fat intake, body mass index and history of hypertension, each 1-unit higher ratio of omega-6 to omega-3 intake was associated with 0.55 mg/L increase in serum CRP (p=0.03). In fully adjusted model, the death hazard ratios (95% confidence interval) for the 1st(1.7-<7.6) 2nd(7.6-<9.3), 3rd(9.3-<11.3) and 4th(11.3-17.4) quartiles of dietary omega-6 to omega-3 ratio were 0.39(0.14-1.18), 0.30(0.09-0.99), 0.67(0.25-1.79) and 1.00(reference), respectively (p-for-trend=0.06). Limitations Three-day food record may underestimate actual dietary fat intake at individual level. Conclusions Higher dietary omega-6 to omega-3 ratio appears associated with both worsening inflammation over time and a trend towards higher death risk in hemodialysis patients. Additional studies including interventional trials are needed to examine
11. Chilled Mirror Dew Point Hygrometer (CM) Handbook
SciTech Connect
Ritsche, MT
2005-01-01
The CM systems have been developed for the ARM Program to act as a moisture standard traceable to National Institute of Standards and Technology (NIST). There are three CM systems that are each fully portable, self-contained, and require only 110 V AC power. The systems include a CM sensor, air sampling and filtration system, a secondary reference (Rotronic HP043 temperature and relative humidity sensor) to detect system malfunctions, a data acquisition system, and data storage for more than one month of 1-minute data. The CM sensor directly measures dew point temperature at 1 m, air temperature at 2 m, and relative humidity at 2 m. These measurements are intended to represent self-standing data streams that can be used independently or in combinations.
12. Conducting Retrospective Ontological Clinical Trials in ICD-9-CM in the Age of ICD-10-CM
PubMed Central
Venepalli, Neeta K; Shergill, Ardaman; Dorestani, Parvaneh; Boyd, Andrew D
2014-01-01
OBJECTIVE To quantify the impact of International Classification of Disease 10th Revision Clinical Modification (ICD-10-CM) transition in cancer clinical trials by comparing coding accuracy and data discontinuity in backward ICD-10-CM to ICD-9-CM mapping via two tools, and to develop a standard ICD-9-CM and ICD-10-CM bridging methodology for retrospective analyses. BACKGROUND While the transition to ICD-10-CM has been delayed until October 2015, its impact on cancer-related studies utilizing ICD-9-CM diagnoses has been inadequately explored. MATERIALS AND METHODS Three high impact journals with broad national and international readerships were reviewed for cancer-related studies utilizing ICD-9-CM diagnoses codes in study design, methods, or results. Forward ICD-9-CM to ICD-10-CM mapping was performing using a translational methodology with the Motif web portal ICD-9-CM conversion tool. Backward mapping from ICD-10-CM to ICD-9-CM was performed using both Centers for Medicare and Medicaid Services (CMS) general equivalence mappings (GEMs) files and the Motif web portal tool. Generated ICD-9-CM codes were compared with the original ICD-9-CM codes to assess data accuracy and discontinuity. RESULTS While both methods yielded additional ICD-9-CM codes, the CMS GEMs method provided incomplete coverage with 16 of the original ICD-9-CM codes missing, whereas the Motif web portal method provided complete coverage. Of these 16 codes, 12 ICD-9-CM codes were present in 2010 Illinois Medicaid data, and accounted for 0.52% of patient encounters and 0.35% of total Medicaid reimbursements. Extraneous ICD-9-CM codes from both methods (Centers for Medicare and Medicaid Services general equivalent mapping [CMS GEMs, n = 161; Motif web portal, n = 246]) in excess of original ICD-9-CM codes accounted for 2.1% and 2.3% of total patient encounters and 3.4% and 4.1% of total Medicaid reimbursements from the 2010 Illinois Medicare database. DISCUSSION Longitudinal data analyses post-ICD-10
13. A microcomputer-based low-cost Omega navigation system
NASA Technical Reports Server (NTRS)
Lilley, R. W.; Salter, R. J., Jr.
1976-01-01
The application of a low cost, commercially available microcomputer as the navigation processor for a simplified OMEGA navigation system is an area of current research. The interface of a low cost front end OMEGA sensor is described and an example of the phase processing software and navigation routines is given. Emphasis is placed on the description of results obtained with the software version of the OMEGA burst filter known as the memory aided phase locked loop.
14. Detections of 2 cm formaldehyde emissions towards Galactic star-forming regions with 6 cm counterpart
Chen, Xi; Shen, Zhi-Qiang; Li, Xiao-Qiong; Yang, Kai; Li, Juan; Wang, Jun-Zhi; Wu, Ya-Jun; Zhao, Rong-Bin; Wang, Jin-Qing; Dong, Jian; Jiang, Dong-Rong; Li, Bin
2017-01-01
We report the detections of H2CO emission at the 2 cm transition towards Galactic star-forming regions with known 6 cm counterpart using the Shanghai Tianma Radio Telescope (TMRT). One significant detection (in NGC7538) and two possible detections (in G23.01-0.41 and G29.96-0.02) were made. Comparing with previous observations, we found that there is a time lag of appearance of 2 cm and 6 cm emissions detected in NGC7538, contradicting with the prediction of radiative pumping via radio continuum radiation. Combinations of the variability of 6 cm masers in NGC7538 suggest that collisional pumping via high-velocity shocks could better explain the 6 cm H2CO maser emission. Under this scheme, excitation of the 2 cm maser may require a higher collision energy compared to the 6 cm transition.
15. Dynamical coupled channels calculation of pion and omega meson production
SciTech Connect
Paris, Mark W.
2009-02-15
The dynamical coupled-channels approach developed at the Excited Baryon Analysis Center is extended to include the {omega}N channel to study {pi}- and {omega}-meson production induced by scattering pions and photons from the proton. Six intermediate channels, including {pi}N, {eta}N, {pi}{delta}, {sigma}N, {rho}N, and {omega}N, are employed to describe unpolarized and polarized data. Bare parameters in an effective hadronic Lagrangian are determined in a fit to the data for {pi}N{yields}{pi}N, {gamma}N{yields}{pi}N, {pi}{sup -}p{yields}{omega}n, and {gamma}p{yields}{omega}p reactions at center-of-mass energies from threshold to W<2.0 GeV. The T matrix determined in these fits is used to calculate the photon beam asymmetry for {omega}-meson production and the {omega}N{yields}{omega}N total cross section and {omega}N-scattering lengths. The calculated beam asymmetry is in good agreement with the observed in the range of energies near threshold to W < or approx. 2.0 GeV.
16. Determining the coordinate dependence of some components of the cubic susceptibility tensor {chi}-hat{sub yyyy}{sup (3)}(z, {omega}, -{omega}, {omega}, {omega}) of a one-dimensionally inhomogeneous absorbing plate at an arbitrary frequency dispersion
SciTech Connect
Golubkov, A A; Makarov, Vladimir A
2010-12-29
The possibility of unique reconstruction of the spatial profile of the cubic nonlinear susceptibility tensor component {chi}-hat{sub yyyy}{sup (3)}(z, {omega}, -{omega}, {omega}, {omega}) of a one-dimensionally inhomogeneous plate whose medium has a symmetry plane m{sub y} perpendicular to its surface is proved for the first time and the unique reconstruction algorithm is proposed. The amplitude complex coefficients of reflection and transmission (measured in some range of angles of incidence) as well as of conversion of an s-polarised plane signal monochromatic wave into two waves propagating on both sides of the plate make it possible to reconstruct the profile. These two waves result from nonlinear interaction of a signal wave with an intense plane wave incident normally on the plate. All the waves under consideration have the same frequency {omega}, and so its variation helps study the frequency dispersion of the cubic nonlinear susceptibility tensor component {chi}-hat{sub yyyy}{sup (3)}(z, {omega}, -{omega}, {omega}, {omega}). For media with additional symmetry axes 2{sub z}, 4{sub z}, 6{sub z}, or {infinity}{sub z} that are perpendicular to the plate surface, the proposed method can be used to reconstruct the profile and to examine the frequency dispersion of about one third of all independent complex components of the tensor {chi}-hat{sup (3)}. (nonlinear-optics phenomena)
17. 46 CFR 35.10-3 - Display of plans-TB/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Display of plans-TB/ALL. 35.10-3 Section 35.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Fire and Emergency Requirements § 35.10-3 Display of plans—TB/ALL. Barges with sleeping accommodations for more than six...
18. 46 CFR 35.10-3 - Display of plans-TB/ALL.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 1 2010-10-01 2010-10-01 false Display of plans-TB/ALL. 35.10-3 Section 35.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Fire and Emergency Requirements § 35.10-3 Display of plans—TB/ALL. Barges with sleeping accommodations for more than six...
19. 46 CFR 35.10-3 - Display of plans-TB/ALL.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 1 2013-10-01 2013-10-01 false Display of plans-TB/ALL. 35.10-3 Section 35.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Fire and Emergency Requirements § 35.10-3 Display of plans—TB/ALL. Barges with sleeping accommodations for more than six...
20. 46 CFR 35.10-3 - Display of plans-TB/ALL.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 1 2014-10-01 2014-10-01 false Display of plans-TB/ALL. 35.10-3 Section 35.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Fire and Emergency Requirements § 35.10-3 Display of plans—TB/ALL. Barges with sleeping accommodations for more than six...
1. 46 CFR 35.10-3 - Display of plans-TB/ALL.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 1 2012-10-01 2012-10-01 false Display of plans-TB/ALL. 35.10-3 Section 35.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Fire and Emergency Requirements § 35.10-3 Display of plans—TB/ALL. Barges with sleeping accommodations for more than six...
2. 5 CFR 10.3 - OPM authority to review personnel management programs and practices.
Code of Federal Regulations, 2011 CFR
2011-01-01
... management programs and practices. 10.3 Section 10.3 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.3 OPM authority to review personnel management programs and practices. The Office...
3. 5 CFR 10.3 - OPM authority to review personnel management programs and practices.
Code of Federal Regulations, 2010 CFR
2010-01-01
... management programs and practices. 10.3 Section 10.3 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.3 OPM authority to review personnel management programs and practices. The Office...
4. 5 CFR 10.3 - OPM authority to review personnel management programs and practices.
Code of Federal Regulations, 2012 CFR
2012-01-01
... management programs and practices. 10.3 Section 10.3 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.3 OPM authority to review personnel management programs and practices. The Office...
5. 5 CFR 10.3 - OPM authority to review personnel management programs and practices.
Code of Federal Regulations, 2014 CFR
2014-01-01
... management programs and practices. 10.3 Section 10.3 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.3 OPM authority to review personnel management programs and practices. The Office...
6. 5 CFR 10.3 - OPM authority to review personnel management programs and practices.
Code of Federal Regulations, 2013 CFR
2013-01-01
... management programs and practices. 10.3 Section 10.3 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.3 OPM authority to review personnel management programs and practices. The Office...
7. A Comparison of 1 T(Omega) and 10 T (Omega) High Resistance Standards Between NIST and Sandia
SciTech Connect
Jarrett, D.G.; Dziuba, R.F.; Kraft, M.E.
1999-04-23
NIST-built 10 T{Omega} and commercial 1 T{Omega} standard resistors were hand carried between NIST and Sandia for a high resistance comparison. The comparison tested the ruggedness of the new NIST-built standard resistors, provided a check of the scaling between the two laboratories, supported measurements to reestablish NIST calibration services at 10 T{Omega} and 100 T{Omega}, and demonstrated the possibility of establishing a NIST high resistance measurement assurance program (MAP). The comparison has demonstrated agreement on the order of 0.07% which is within the expanded uncertainties (coverage factor = 2) of NIST and Sandia at 1 T{Omega} and 10 T{Omega}.
8. Detection of Thermal 2 cm and 1 cm Formaldehyde Emission in NGC 7538
Yuan, Liang; Araya, E. D.; Hofner, P.; Kurtz, S.; Pihlstrom, Y.
2011-05-01
Formaldehyde is a tracer of high density gas in massive star forming regions. The K-doublet lines from the three lowest rotational energy levels of ortho-formaldehyde correspond to wavelengths of 6, 2 and 1 cm. Thermal emission of these transitions is rare, and maser emission has only been detected in the 6 cm line. NGC 7538 is an active site of massive star formation in the Galaxy, and one of only a few regions known to harbor 6 cm formaldehyde (H2CO) masers. Using the NRAO 100 m Green Bank Telescope (GBT), we detected 2 cm H2CO emission toward NGC 7538 IRS1. The velocity of the 2 cm H2CO line is very similar to the velocity of one of the 6 cm H2CO masers but the linewidth is greater. To investigate the nature of the 2 cm emission, we conducted observations of the 1 cm H2CO transition, and obtained a cross-scan map of the 2 cm line. We detected 1 cm emission and found that the 2 cm emission is extended (greater than 30"), which implies brightness temperatures of ˜0.2 K. Assuming optically thin emission, LTE, and that the 1 cm and 2 cm lines originate from the same volume of gas, both these detections are consistent with thermal emission of gas at ˜30 K. We conclude that the 1 cm and 2 cm H2CO lines detected with the GBT are thermal, which implies molecular densities above ˜105 cm-3. LY acknowledges support from WIU. PH acknowledges partial support from NSF grant AST-0908901.
9. Effect of a diet enriched with omega-6 and omega-3 fatty acids on the pig liver transcriptome.
PubMed
Szostak, Agnieszka; Ogłuszka, Magdalena; Te Pas, Marinus F W; Poławska, Ewa; Urbański, Paweł; Juszczuk-Kubiak, Edyta; Blicharski, Tadeusz; Pareek, Chandra Shekhar; Dunkelberger, Jenelle R; Horbańczuk, Jarosław O; Pierzchała, Mariusz
2016-01-01
The optimal ratio of omega-6 to omega-3 polyunsaturated fatty acids (PUFAs) is important for keeping the homeostasis of biological processes and metabolism, yet the underlying biological mechanism is poorly understood. The objective of this study was to identify changes in the pig liver transcriptome induced by a diet enriched with omega-6 and omega-3 fatty acids and to characterize the biological mechanisms related to PUFA metabolism. Polish Landrace pigs (n = 12) were fed diet enriched with linoleic acid (LA, omega-6) and α-linolenic acid (ALA, omega-3) or standard diet as a control. The fatty acid profiling was assayed in order to verify how feeding influenced the fatty acid content in the liver, and subsequently next-generation sequencing (NGS) was used to identify differentially expressed genes (DEG) between transcriptomes between dietary groups. The biological mechanisms and pathway interaction networks were identified using DAVID and Cytoscape tools. Fatty acid profile analysis indicated a higher contribution of PUFAs in the liver for LA- and ALA-enriched diet group, particularly for the omega-3 fatty acid family, but not omega-6. Next-generation sequencing identified 3565 DEG, 1484 of which were induced and 2081 were suppressed by PUFA supplementation. A low ratio of omega-6/omega-3 fatty acids resulted in the modulation of fatty acid metabolism pathways and over-representation of genes involved in energy metabolism, signal transduction, and immune response pathways. In conclusion, a diet enriched with omega-6 and omega-3 fatty acids altered the transcriptomic profile of the pig liver and would influence animal health status.
10. Probing lepton asymmetry with 21 cm fluctuations
SciTech Connect
Kohri, Kazunori; Oyama, Yoshihiko; Sekiguchi, Toyokazu; Takahashi, Tomo E-mail: oyamayo@post.kek.jp E-mail: tomot@cc.saga-u.ac.jp
2014-09-01
We investigate the issue of how accurately we can constrain the lepton number asymmetry ξ{sub ν}=μ{sub ν}/T{sub ν} in the Universe by using future observations of 21 cm line fluctuations and cosmic microwave background (CMB). We find that combinations of the 21 cm line and the CMB observations can constrain the lepton asymmetry better than big-bang nucleosynthesis (BBN). Additionally, we also discuss constraints on ξ{sub ν} in the presence of some extra radiation, and show that the 21 cm line observations can substantially improve the constraints obtained by CMB alone, and allow us to distinguish the effects of the lepton asymmetry from the ones of extra radiation.
11. Effect of dietary intake of omega-3 and omega-6 fatty acids on severity of asthma in children.
PubMed
Hodge, L; Salome, C M; Hughes, J M; Liu-Brennan, D; Rimmer, J; Allman, M; Pang, D; Armour, C; Woolcock, A J
1998-02-01
We assessed the clinical and biochemical effects in asthmatic children of fish oil supplementation and a diet that increases omega-3 and reduces omega-6 fatty acids. Thirty nine asthmatic children aged 8-12 yrs participated in a double-blind, randomized, controlled trial for 6 months during which they received fish oil capsules plus canola oil and margarine (omega-3 group) or safflower oil capsules plus sunflower oil and margarine (omega-6 group). Plasma fatty acids, stimulated tumour necrosis factor alpha (TNFalpha) production, circulating eosinophil numbers and lung function were measured at baseline and after 3 and 6 months of dietary modification. Day and night symptoms, peak flow rates and medication use were recorded for 1 week prior to laboratory visits. Plasma phospholipid omega-3 fatty acids were significantly greater in the omega-3 group at 3 and 6 months compared to the omega-6 group (p<0.001). In the omega-3 group TNFalpha production fell significantly compared with baseline (p=0.026), but the magnitude of change between groups did not reach significance (p=0.075). There were no significant changes in clinical outcome measures. Dietary enrichment of omega-3 fatty acids over 6 months increased plasma levels of these fatty acids, reduced stimulated tumour necrosis factor alpha production, but had no effect on the clinical severity of asthma in these children.
12. The role of the tissue omega-6/omega-3 fatty acid ratio in regulating tumor angiogenesis.
PubMed
Kang, Jing X; Liu, Angela
2013-06-01
Angiogenesis is a necessary step in tumor growth and metastasis. It is well established that the metabolites of omega-6 and omega-3 fatty acids, which must be obtained through the diet and cannot be synthesized de novo in mammals, have differential effects on cellular processes. Omega-6 fatty acid (n-6 FA)-derived metabolites promote angiogenesis by increasing growth factor expression whereas omega-3 fatty acids (n-3 FA) have anti-angiogenic and antitumor properties. However, most studies thus far have failed to account for the role of the n-6 FA/n-3 FA ratio in angiogenesis and instead examined the absolute levels of n-6 and n-3 FA. This review highlights the biochemical interactions between n-6 and n-3 FA and focuses on how the n-6/n-3 FA ratio in tissues modulates tumor angiogenesis. We suggest that future work should consider the n-6/n-3 FA ratio to be a key element in experimental design and analysis. Furthermore, we recommend that clinical interventions should aim to both reduce n-6 metabolites and simultaneously increase n-3 FA intake.
13. Observation of {chi}{sub c1} Decays into Vector Meson Pairs {phi}{phi}, {omega}{omega}, and {omega}{phi}
SciTech Connect
Ablikim, M.; An, Z. H.; Bai, J. Z.; Berger, N.; Bian, J. M.; Cai, X.; Cao, G. F.; Cao, X. X.; Chang, J. F.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, Y.; Chen, Y. B.; Chu, Y. P.; Dai, H. L.; Dai, J. P.; Deng, Z. Y.; Dong, L. Y.
2011-08-26
Using (106{+-}4)x10{sup 6} {psi}(3686) events accumulated with the BESIII detector at the BEPCII e{sup +}e{sup -} collider, we present the first measurement of decays of {chi}{sub c1} to vector meson pairs {phi}{phi}, {omega}{omega}, and {omega}{phi}. The branching fractions are measured to be (4.4{+-}0.3{+-}0.5)x10{sup -4}, (6.0{+-}0.3{+-}0.7)x10{sup -4}, and (2.2{+-}0.6{+-}0.2)x10{sup -5}, for {chi}{sub c1}{yields}{phi}{phi}, {omega}{omega}, and {omega}{phi}, respectively, which indicates that the hadron helicity selection rule is significantly violated in {chi}{sub cJ} decays. In addition, the measurement of {chi}{sub cJ}{yields}{omega}{phi} provides the first indication of the rate of doubly OZI-suppressed {chi}{sub cJ} decay. Finally, we present improved measurements for the branching fractions of {chi}{sub c0} and {chi}{sub c2} to vector meson pairs.
14. 21 CM searches for DIM galaxies
Disney, Mike; Banks, Gareth
1997-04-01
We review very strong selection effects which operate against the detection of dim (i.e. low surface brightness) galaxies. The Parkes multibeam instrument offers a wonderful opportunity to turn up new populations of such galaxies. However, to explore the newly accessible parameter space, it will be necessary to survey both a very deep patch (105 s/pointing, limiting N hi ˜ 1018 cm-2) and a deep patch (104 s/pointing, limiting N hi ˜ 3 × 1018 cm-2) in carefully selected areas, and we outline the case to do this.
15. A novel lead compound CM-118
PubMed Central
Meng, Lanfang; Shu, Mengjun; Chen, Yaqing; Yang, Dexiao; He, Qun; Zhao, Hui; Feng, Zhiyong; Liang, Chris; Yu, Ker
2014-01-01
The anaplastic lymphoma kinase (ALK) and the c-Met receptor tyrosine kinase play essential roles in the pathogenesis in multiple human cancers and present emerging targets for cancer treatment. Here, we describe CM-118, a novel lead compound displaying low nanomolar biochemical potency against both ALK and c-Met with selectivity over >90 human kinases. CM-118 potently abrogated hepatocyte growth factor (HGF)-induced c-Met phosphorylation and cell migration, phosphorylation of ALK, EML4-ALK, and ALK resistance mutants in transfected cells. CM-118 inhibited proliferation and/or induced apoptosis in multiple c-Met- and ALK-addicted cancer lines with dose response profile correlating target blockade. We show that the CM-118-induced apoptosis in c-Met-amplified H1993 NSCLC cells involved a rapid suppression of c-Met activity and c-Met-to-EGFR cross-talk, and was profoundly potentiated by EGFR inhibitors as shown by the increased levels of apoptotic proteins cleaved-PARP and Bim as well as reduction of the survival protein Mcl-1. Bim-knockdown or Mcl-1 overexpression each significantly attenuated apoptosis. We also revealed a key role by mTOR in mediating CM-118 action against the EML4-ALK-dependent NSCLC cells. Abrogation of EML4-ALK in H2228 cells profoundly reduced signaling capacity of the rapamycin-sensitive mTOR pathway leading to G1 cell cycle arrest and mitochondrial hyperpolarization, a metabolic perturbation linked to mTOR inhibition. Depletion of mTOR or mTORC1 inhibited H2228 cell growth, and mTOR inhibitors potentiated CM-118’s antitumor activity in vitro and in vivo. Oral administration of CM-118 at a wide range of well tolerated dosages diminished c-Met- and ALK phosphorylation in vivo, and caused tumor regression or growth inhibition in multiple c-Met- and ALK-dependent tumor xenografts in mice. CM-118 exhibits favorable pharmacokinetic and drug metabolism properties hence presents a candidate for clinical evaluation. PMID:24618813
16. A Propensity for n-omega-Amino Acids in Thermally-Altered Antarctic Meteorites
NASA Technical Reports Server (NTRS)
Burton, Aaron S.; Elsila, Jamie E.; Callahan, Michael P.; Martin, Mildred G.; Glavin, Daniel P.; Johnson, Natasha M.; Dworkin, Jason P.
2012-01-01
Carbonaceous meteorites are known to contain a wealth of indigenous organic molecules, including amino acids, which suggests that these meteorites could have been an important source of prebiotic organic material during the origins of life on Earth and possibly elsewhere. We report the detection of extraterrestrial amino acids in thermally-altered type 3 CV and CO carbonaceous chondrites and ureilites recovered from Antarctica. The amino acid concentrations of the thirteen Antarctic meteorites were generally less abundant than in more amino acid-rich CI, CM, and CR carbonaceous chondrites that experienced much lower temperature aqueous alteration on their parent bodies. In contrast to low-temperature aqueously-altered meteorites that show complete structural diversity in amino acids formed predominantly by Strecker-cyanohydrin synthesis, the thermally-altered meteorites studied here are dominated by small, straight-chain, amine terminal (n-omega-amino) amino acids that are not consistent with Strecker formation. The carbon isotopic ratios of two extraterrestrial n-omega-amino acids measured in one of the CV chondrites are consistent with C-13-depletions observed previously in hydrocarbons produced by Fischer-Tropsch type reactions. The predominance of n-omega-amino acid isomers in thermally-altered meteorites hints at cosmochemical mechanisms for the preferential formation and preservation of a small subset of the possible amino acids.
17. OmegaCAM: The VST Camera
Cappellarao, E.
2005-06-01
OmegaCAM is the large-format CCD pixels imaging camera that has been designed to exploit the square degree field of view of the VST while sampling the excellent seeing of Paranal (Kuijken et al. 2002, The Messenger 110, 15). The instrument is built by a consortium which comprises institutes in the Netherlands, Germany and Italy, and is headed by PI Konrad Kuijken (Groningen and Leiden University) with co-PI's Ralf Bender (Munich USM/MPE) and Enrico Cappellaro (INAF Naples), and project management by Bernhard Muschielok and Reinhold Häfner (USM). The Optical Detector Team at ESO has designed and built the detector system.
18. North Atlantic OMEGA Navigation System Validation
DTIC Science & Technology
1980-07-21
Coordinates 7-18 7-7 Aeroflot Flight Zone OMEGA Accuracies vs DME or DME /VOR Coordinates 7-18 7-8 Alabama Getty Measurements 7-20 7-9 British Respect...navigation equipment on board the aircraft during the tests consisted of TAC.N VOR/ DME , sextant and a driftmeter. The majority of flight hours were...measurement of two (2) distances from DME , or azimuth and distance for VOR/ DME with distances from the radio beacons of not more than 40 KM. During the
19. Gamma bang time analysis at OMEGA.
PubMed
McEvoy, A M; Herrmann, H W; Horsfield, C J; Young, C S; Miller, E K; Mack, J M; Kim, Y; Stoeffl, W; Rubery, M; Evans, S; Sedillo, T; Ali, Z A
2010-10-01
Absolute bang time measurements with the gas Cherenkov detector (GCD) and gamma reaction history (GRH) diagnostic have been performed to high precision at the OMEGA laser facility at the University of Rochester with bang time values for the two diagnostics agreeing to within 5 ps on average. X-ray timing measurements of laser-target coupling were used to calibrate a facility-generated laser timing fiducial with rms spreads in the measured coupling times of 9 ps for both GCD and GRH. Increased fusion yields at the National Ignition Facility (NIF) will allow for improved measurement precision with the GRH easily exceeding NIF system design requirements.
20. [Cutaneous Melanoma (CM): Current Diagnosis and Treatment].
PubMed
Gallegos Hernández, José Francisco; Nieweg, Omgo E
2014-12-01
Cutaneous melanoma (CM) is the third most common cancer of the skin, but it is the neoplasia with the greatest impact on mortality. Its etiology is multifactorial and it has been reported that its prevalence has increased in the last two decades. In Mexico, CM ranks seventh in frequency among all malignancies and 80% of cases are in locally advanced stages. The prognosis depends on the stage. The prognostic factors with greatest impact in survival are nodal status, tumor thickness or Breslow depth, ulceration, and in thin melanomas (< 1 mm thickness, without ulceration and Clarck level III), the mitotic index. The diagnostic approach is of great importance to achieve adequate treatment. Adherence to global guidelines of treatment allows us to obtain the best rates of locoregional control, which is the first target to be achieved in patients with CM. The goal of this manuscript is to provide a synthesis of the most important aspects in the diagnosis and treatment of CM, based on current evidence obtained in the literature.
1. Neutron Resonance Parameters for Cm-242 (Curium)
Sukhoruchkin, S. I.; Soroko, Z. N.
This document is part of the Supplement containing the complete sets of data of Volume 24 Neutron Resonance Parameters' of Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms'. It provides the neutron resonance parameters for the isotope Cm-242 (Curium).
2. Anomalous RR Lyrae stars(?): CM Leonis
Di Fabrizio, L.; Clementini, G.; Marconi, M.; Carretta, E.; Ivans, I. I.; Bragaglia, A.; Di Tomaso, S.; Merighi, R.; Smith, H. A.; Sneden, C.; Tosi, M.
2002-11-01
Time-series of B, V, I CCD photometry and radial velocity measurements from high-resolution spectroscopy (R= 30 000) covering the full pulsation cycle are presented for the field RR Lyrae star CM Leonis. The photometric data span a 6-yr interval from 1994 to 1999, and allow us to firmly establish the pulsation mode and periodicity of the variable. The derived period P= 0.361 699 d (+/-0.000001) is very close to the value published in the Fourth Edition of the General Catalogue of Variable Stars (P= 0.361 732 d). However, contrary to what was previously found, the amplitude and shape of the light curve qualify CM Leo as a very regular first overtone pulsator with a prominent hump on the rising branch of its multicolour light curves. According to an abundace analysis performed on three spectra taken near minimum light (0.42 < φ < 0.61), CM Leo is a metal-poor star with metal abundance [Fe/H]=-1.93 +/- 0.20. The photometric and radial velocity curves of CM Leo have been compared with the predictions of suitable pulsational models to infer tight constraints on the stellar mass, effective temperature, and distance modulus of the star. We derive a true distance modulus of CM Leo of μ0= 13.11 +/- 0.02 mag and a corresponding absolute magnitude of MV= 0.47 +/- 0.04. This absolute magnitude, once corrected for evolutionary and metallicity effects, leads to a true distance modulus of the Large Magellanic Cloud of μ0= 18.43 +/- 0.06 mag, in better agreement with the long astronomical distance scale.
3. Towards the 1-cm SARAL orbit
Zelensky, Nikita P.; Lemoine, Frank G.; Chinn, Douglas S.; Beckley, Brian D.; Bordyugov, Oleg; Yang, Xu; Wimert, Jesse; Pavlis, Despina
2016-12-01
We have investigated the quality of precise orbits for the SARAL altimeter satellite using Satellite Laser Ranging (SLR) and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) data from March 14, 2013 to August 10, 2014. We have identified a 4.31 ± 0.14 cm error in the Z (cross-track) direction that defines the center-of-mass of the SARAL satellite in the spacecraft coordinate system, and we have tuned the SLR and DORIS tracking point offsets. After these changes, we reduce the average RMS of the SLR residuals for seven-day arcs from 1.85 to 1.38 cm. We tuned the non-conservative force model for SARAL, reducing the amplitude of the daily adjusted empirical accelerations by eight percent. We find that the best dynamic orbits show altimeter crossover residuals of 5.524 cm over cycles 7-15. Our analysis offers a unique illustration that high-elevation SLR residuals will not necessarily provide an accurate estimate of radial error at the 1-cm level, and that other supporting orbit tests are necessary for a better estimate. Through the application of improved models for handling time-variable gravity, the use of reduced-dynamic orbits, and through an arc-by-arc estimation of the C22 and S22 coefficients, we find from analysis of independent SLR residuals and other tests that we achieve 1.1-1.2 cm radial orbit accuracies for SARAL. The limiting errors stem from the inadequacy of the DPOD2008 and SLRF2008 station complements, and inadequacies in radiation force modeling, especially with respect to spacecraft self-shadowing and modeling of thermal variations due to eclipses.
4. Particle-number conserving analysis of rotational bands in {sup 247,249}Cm and {sup 249}Cf
SciTech Connect
Zhang Zhenhua; Zeng Jinyan; Zhao Enguang; Zhou Shangui
2011-01-15
The recently observed high-spin rotational bands in odd-A nuclei {sup 247,249}Cm and {sup 249}Cf[Tandel et al., Phys. Rev. C 82, 041301(R) (2010)] are investigated by using the cranked-shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method in which the blocking effects are taken into account exactly. The experimental moments of inertia and alignments and their variations with the rotational frequency {omega} are reproduced very well by the PNC-CSM calculations. By examining the {omega} dependence of the occupation probability of each cranked Nilsson orbital near the Fermi surface and the contributions of valence orbitals to the angular momentum alignment in each major shell, the level crossing and upbending mechanism in each nucleus is understood clearly.
5. Interaction between omega 3 PUFA and UVB radiation: Photoprotective effect in normal and tumoral murine melanocytes?
PubMed
Vasconcelos, Renata Ottes; Bustos, Silvina Odete; Gonzalez, Juliana Ramos; Soares, Camila Wink; Barbosa, Makely Daiane; Chammas, Roger; Votto, Ana Paula de Souza; Trindade, Gilma Santos
2016-11-01
Omega 3 polyunsaturated fatty acids (omega 3 PUFA) are attracting a growing interest as potential adjuvants for cancer prevention and treatment. There is evidence about photoprotection in normal cells, but few previous studies have evaluated it in tumoral cells. Therefore, this study investigated the effect of α-linolenic acid (ALA) in normal murine melanocytic cells (Melan-a) and in tumoral murine melanocytic cells (B16F10) exposed to UVB radiation. Our results showed that ALA exhibited an antiproliferative effect in B16F10 cells, and had minimal effect in Melan-a cells, as demonstrated by MTT assay. On the other hand, the combination of ALA (7.5μM) and UVB (0.01J/cm(2)) showed a protective effect for both cell lines, Melan-a and B16F10. ALA and UVB combined or UVB alone induced an accumulation of cell lines at the S/G2/M phase. In addition, the combination of ALA and UVB, and UVB alone, both induced cell death in 24h; and in 48h, ALA attenuated this effect in both cells. Further to these findings, it was demonstrated that ALA did not alter ROS levels in both cells exposed to UVB radiation. The effect of an omega 6 PUFA, linoleic acid, under the same conditions of ALA were tested. It was not protective in either cell line. Therefore, our results can be very important since it was shown another role to an omega 3 PUFA as a photoprotective agent in a melanoma cell.
6. Selected bibliography of OMEGA, VLF and LF techniques applied to aircraft navigation systems
NASA Technical Reports Server (NTRS)
1974-01-01
A bibliography is presented which includes references to the OMEGA navigation system, very low frequencies, time-frequency measurements, air traffic control, radio navigation, and applications of OMEGA.
7. Prenatal omega-3 fatty acids: review and recommendations.
PubMed
Jordan, Robin G
2010-01-01
The influence of dietary omega-3 fatty acids on health outcomes is widely recognized. The adequate intake of omega-3 fatty acids docasahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in particular can increase gestation length and improve infant cognitive and visual performance. Adequate levels of omega-3 fatty acids have also been shown to reduce the incidence of preterm birth in some populations. Research on prenatal omega-3 intake and other outcomes, such as preeclampsia and fetal growth restriction, is inconclusive. Women in the United States consume low levels of omega-3 fatty acids compared to omega-6 fatty acids; this dietary pattern is associated with poor health outcomes. Omega-3 fatty acids are found primarily in fish, yet many pregnant women avoid fish because of concerns about potential mercury and polychlorinated biphenyl contamination. It is important for prenatal care providers to assess women's diets for omega-3 fatty acid intake and ensure that pregnant women are consuming between 200 and 300 mg daily from safe food sources. Purified fish, algal oil supplements, and DHA-enriched eggs are alternative sources for pregnant women who do not eat fish.
8. A proposed microcomputer implementation of an Omega navigation processor
NASA Technical Reports Server (NTRS)
Abel, J. D.
1976-01-01
A microprocessor navigation systems using the Omega process is discussed. Several methods for correcting incoming sky waves are presented along with the hardware design which depends on a microcomputer. The control program is discussed, and block diagrams of the Omega processor and interface systems are presented.
9. Cloning and characterization of a novel feline IFN-omega.
PubMed
Yang, Li-Min; Xue, Qing-Hua; Sun, Lei; Zhu, Yi-Ping; Liu, Wen-Jun
2007-02-01
The interferons (IFNs) are a large family of multifunctional secreted protein involved in antiviral defense, cell growth regulation, and immune activation. The human IFNs are used worldwide as antiviral drugs. Here, we present cDNAs encoding 13 novel feline IFN-omega (FeIFN-omega) subtypes that share 95%-99% amino acid sequence identity. FeIFN-omega2 and FeIFN-omega4 have seven additional amino acids at position 109 that are not present in other subtypes. Sequence identity of the present FeIFN proteins encoded by the 13 subtypes is approximately 57% compared with human IFN-omega (HuIFN-omega). All 13 FeIFN-omega subtypes were expressed in Escherichia coli using a periplasmic expression system. The antiviral activity of each product was evaluated in vitro. In addition, subtype FeIFN-omega2 was cytoplasm expressed in E. coli and secretion expressed in Pichia pastoris. The purified mature recombinant protein demonstrated significant antiviral activity on both homologous and heterologous animal cells in vitro.
SciTech Connect
Theobald, W; Anderson, K S; Betti, R; Craxton, R S; Delettrez, J A; Frenje, J A; Glebov, V Yu; Gotchev, O V; Kelly, J H; Li, C K; Mackinnon, A J; Marshall, F J; McCrory, R L; Meyerhofer, D D; Myatt, J F; Norreys, P A; Nilson, P M; Patel, P K; Petrasso, R D; Radha, P B; Ren, C; Sangster, T C; Seka, W; Smalyuk, V A; Solodov, A A; Stephens, R B; Stoeckl, C; Yaakobi, B
2009-11-24
Advanced ignition concepts, such as fast ignition and shock ignition, are being investigated at the Omega Laser Facility. Integrated fast-ignition experiments with room-temperature re-entrant cone targets have begun, using 18 kJ of 351 nm drive energy to implode empty 40μm thick CD shells, followed by 1.0 kJ of 1053 nm wavelength, short-pulse energy. Short pulses of 10 ps width have irradiated the inside of a hollow gold re-entrant cone at the time of peak compression. A threefold increase in the time-integrated, 2 to 7 keV x-ray emission was observed with x-ray pinhole cameras, indicating that energy is coupled from the short-pulse laser into the core by fast electrons. In shock-ignition experiments, spherical plastic-shell targets were compressed to high areal densities on a low adiabat, and a strong shock wave was sent into the converging, compressed capsule. In one experiment, 60 beams were used with an intensity spike at the end of the laser pulse, and the implosion performance was studied through neutron-yield and areal-density measurements. In a second experiment, the 60 OMEGA beams were split into a 40+20 configuration, with 40 low-intensity beams used for fuel assembly and 20 delayed beams with a short, high-intensity pulse shape (up to 1×1016 Wcm^-2) for shock generation.
SciTech Connect
Theobald, W; Anderson, K S; Betti, R; Craxton, R S; Delettrez, J A; Frenje, J A; Glebov, V Yu; Gotchev, O V; Kelly, J H; Li, C K; Mackinnon, A J; Marshall, F J; McCrory, R L; Meyerhofer, D D; Myatt, J F; Norreys, P A; Nilson, P M; Patel, P K; Petrasso, R D; Radha, P B; Ren, C; Sangster, T C; Seka, W; Smalyuk, V A; Solodov, A A; Stephens, R B; Stoeckl, C; Yaakobi, B
2009-11-24
Advanced ignition concepts, such as fast ignition and shock ignition, are being investigated at the Omega Laser Facility. Integrated fast-ignition experiments with room-temperature re-entrant cone targets have begun, using 18 kJ of 351 nm drive energy to implode empty 40μm thick CD shells, followed by 1.0 kJ of 1053 nm wavelength, short-pulse energy. Short pulses of 10 ps width have irradiated the inside of a hollow gold re-entrant cone at the time of peak compression. A threefold increase in the time-integrated, 2 to 7 keV x-ray emission was observed with x-ray pinhole cameras, indicating that energy is coupled from the short-pulse laser into the core by fast electrons. In shock-ignition experiments, spherical plastic-shell targets were compressed to high areal densities on a low adiabat, and a strong shock wave was sent into the converging, compressed capsule. In one experiment, 60 beams were used with an intensity spike at the end of the laser pulse, and the implosion performance was studied through neutron-yield and areal-density measurements. In a second experiment, the 60 OMEGA beams were split into a 40+20 configuration, with 40 low-intensity beams used for fuel assembly and 20 delayed beams with a short, high-intensity pulse shape (up to 1×1016 Wcm-2) for shock generation.
12. Measurements of Output Factors For Small Photon Fields Up to 10 cm x 10 cm
Bacala, Angelina
Field output factors (OF) for photon beams from a 6 MV medical accelerator were measured using five different detectors in a scanning water phantom. The measurements were taken for square field sizes of integral widths ranging from 1 cm to 10 cm for two reference source-to-surface distances (SSD) and depths in water. For the diode detectors, square field widths as small as 2.5 mm were also studied. The photon beams were collimated by using either the jaws or the multileaf collimators. Measured OFs are found to depend upon the field size, SSD, depth and also upon the type of beam collimation, size and type of detector used. For field sizes larger than 3 cm x 3 cm, the OF measurements agree to within 1% or less. The largest variation in OF occurs for jawsshaped field of size 1 cm x 1cm, where a difference of more than 18% is observed.
13. Interpreting Sky-Averaged 21-cm Measurements
Mirocha, Jordan
2015-01-01
Within the first ~billion years after the Big Bang, the intergalactic medium (IGM) underwent a remarkable transformation, from a uniform sea of cold neutral hydrogen gas to a fully ionized, metal-enriched plasma. Three milestones during this epoch of reionization -- the emergence of the first stars, black holes (BHs), and full-fledged galaxies -- are expected to manifest themselves as extrema in sky-averaged ("global") measurements of the redshifted 21-cm background. However, interpreting these measurements will be complicated by the presence of strong foregrounds and non-trivialities in the radiative transfer (RT) modeling required to make robust predictions.I have developed numerical models that efficiently solve the frequency-dependent radiative transfer equation, which has led to two advances in studies of the global 21-cm signal. First, frequency-dependent solutions facilitate studies of how the global 21-cm signal may be used to constrain the detailed spectral properties of the first stars, BHs, and galaxies, rather than just the timing of their formation. And second, the speed of these calculations allows one to search vast expanses of a currently unconstrained parameter space, while simultaneously characterizing the degeneracies between parameters of interest. I find principally that (1) physical properties of the IGM, such as its temperature and ionization state, can be constrained robustly from observations of the global 21-cm signal without invoking models for the astrophysical sources themselves, (2) translating IGM properties to galaxy properties is challenging, in large part due to frequency-dependent effects. For instance, evolution in the characteristic spectrum of accreting BHs can modify the 21-cm absorption signal at levels accessible to first generation instruments, but could easily be confused with evolution in the X-ray luminosity star-formation rate relation. Finally, (3) the independent constraints most likely to aide in the interpretation
14. Omega-3 fatty acids in major depressive disorder.
PubMed
Freeman, Marlene P
2009-01-01
Patients with major depressive disorder have high rates of cardiovascular disease and other medical comorbidity. Omega-3 fatty acids, particularly those found in fish and seafood, have cardiovascular health benefits and may play an adjunctive role in the treatment of mood disorders. However, existing studies on omega-3 fatty acids in depression have limitations such as small sample sizes and a wide variance in study design, and results regarding efficacy are mixed. The preponderance of data from placebo-controlled treatment studies suggests that omega-3 fatty acids are a reasonable augmentation strategy for the treatment of major depressive disorder. More research is necessary before omega-3 supplements can be recommended as monotherapy for the treatment of depression. For many individuals with major depressive disorder, augmentation with omega-3 fatty acids should be considered, as general health benefits are well established and adjunctive use is low risk.
15. Observation of in-medium modifications of the omega meson.
PubMed
Trnka, D; Anton, G; Bacelar, J C S; Bartholomy, O; Bayadilov, D; Beloglazov, Y A; Bogendörfer, R; Castelijns, R; Crede, V; Dutz, H; Ehmanns, A; Elsner, D; Ewald, R; Fabry, I; Fuchs, M; Essig, K; Funke, Ch; Gothe, R; Gregor, R; Gridnev, A B; Gutz, E; Höffgen, S; Hoffmeister, P; Horn, I; Hössl, J; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Klein, Frank; Klein, Fritz; Klempt, E; Konrad, M; Kopf, B; Kotulla, M; Krusche, B; Langheinrich, J; Löhner, H; Lopatin, I V; Lotz, J; Lugert, S; Menze, D; Messchendorp, J G; Mertens, T; Metag, V; Morales, C; Nanova, M; Novotny, R; Ostrick, M; Pant, L M; van Pee, H; Pfeiffer, M; Roy, A; Radkov, A; Schadmand, S; Schmidt, Ch; Schmieden, H; Schoch, B; Shende, S; Suft, G; Sumachev, V V; Szczepanek, T; Süle, A; Thoma, U; Varma, R; Walther, D; Weinheimer, Ch; Wendel, Ch
2005-05-20
The photoproduction of omega mesons on nuclei has been investigated using the Crystal Barrel/TAPS experiment at the ELSA tagged photon facility in Bonn. The aim is to study possible in-medium modifications of the omega meson via the reaction gamma + A --> omega + X --> pi(0)gamma + X('). Results obtained for Nb are compared to a reference measurement on a LH2 target. While for recoiling, long-lived mesons (pi(0), eta, and eta;(')), which decay outside of the nucleus, a difference in the line shape for the two data samples is not observed, we find a significant enhancement towards lower masses for omega mesons produced on the Nb target. For momenta less than 500 MeV/c an in-medium omega meson mass of M(medium) = [722(+4)(-4)(stat)+35-5(syst)] MeV/c(2) has been deduced at an estimated average nuclear density of 0.6rho(0).
16. Electromagnetic Tunneling and Resonances in Pseudochiral Omega Slabs
PubMed Central
Razzaz, Faroq; Alkanhal, Majeed A. S.
2017-01-01
This paper presents theoretical investigation of the electromagnetic wave tunneling and anomalous transmission around the trapped modes in a pseudochiral omega slab. The dispersion relation, the conditions of the trapped modes, and the evanescent wave coupling and tunneling in two different reciprocal pseudochiral omega slab structures are derived. The Berreman’s matrix method is applied to obtain the transmission coefficients across the pseudochiral omega slab. When the structure is perturbed, a resonance phenomenon is detected around the trapped modes. This resonance results in transmission anomalies (total transmission and total reflection) and dramatic field amplifications around the trapped modes. The number of the discrete trapped modes and then the resonance frequencies are prescribed by the parameters of the pseudochiral omega slab such as the value of the omega parameter and its orientation and the slab thickness. PMID:28165058
17. Bioavailability of long-chain omega-3 fatty acids.
PubMed
Schuchardt, Jan Philipp; Hahn, Andreas
2013-07-01
Supplements have reached a prominent role in improving the supply of long-chain omega-3 fatty acids, such as Eicosapentaenoic acid (EPA 20:5n-3) and Docosahexaenoic acid (DHA 22:6n-3). Similar to other nutrients, the availability of omega-3 fatty acids is highly variable and determined by numerous factors. However, the question of omega-3 fatty acids bioavailability has long been disregarded, which may have contributed to the neutral or negative results concerning their effects in several studies. This review provides an overview of the influence of chemical binding form (free fatty acids bound in ethylesters, triacylglycerides or phospholipids), matrix effects (capsule ingestion with concomitant intake of food, fat content in food) or galenic form (i.e. microencapsulation, emulsification) on the bioavailability of omega-3 fatty acids. There is a need to systematically investigate the bioavailability of omega-3 fatty acids formulations, which might be a key to designing more effective studies in the future.
18. Data Simulation for 21 cm Cosmology Experiments
Pober, Jonathan
2017-01-01
21 cm cosmologists seek a measurement of the hyperfine line of neutral hydrogen from very high redshifts. While this signal has the potential to provide an unprecedented view into the early universe, it is also buried under exceedingly bright foreground emission. Over the last several years, 21 cm cosmology research has led to an improved understanding of how low frequency radio interferometers will affect the separation of cosmological signal from foregrounds. This talk will describe new efforts to incorporate this understanding into simulations of the most realistic data sets for the Precision Array for Probing the Epoch of Reionization (PAPER), the Murchison Widefield Array (MWA), and the Hydrogen Epoch of Reionization Array (HERA). These high fidelity simulations are essential for robust algorithm design and validation of early results from these experiments.
19. Extended Performance 8-cm Mercury Ion Thruster
NASA Technical Reports Server (NTRS)
Mantenieks, M. A.
1981-01-01
A slightly modified 8-cm Hg ion thruster demonstrated significant increase in performance. Thrust was increased by almost a factor of five over that of the baseline thruster. Thruster operation with various three grid ion optics configurations; thruster performance as a function of accelerator grid open area, cathode baffle, and cathode orifice size; and a life test of 614 hours at a beam current of 250 mA (17.5 mN thrust) are discussed. Highest thruster efficiency was obtained with the smallest open area accelerator grid. The benefits in efficiency from the low neutral loss grids were mitigated, however, by the limitation such grids place on attainable ion beam current densities. The thruster components suffered negligible weight losses during a life test, which indicated that operation of the 8-cm thruster at extended levels of thrust and power is possible with no significant loss of lifetime.
20. Omega-6 to Omega-3 Fatty Acid Ratio in Patients with ADHD: A Meta-Analysis
PubMed Central
LaChance, Laura; McKenzie, Kwame; Taylor, Valerie H.; Vigod, Simone N.
2016-01-01
1. 15 cm multipole gas ion thruster
NASA Technical Reports Server (NTRS)
Isaacson, G. C.; Kaufman, H. R.
1976-01-01
A 15-cm multipole thruster was operated on argon and xenon. The multipole approach used has been shown capable of low discharge losses and flat ion beam profiles with a minimum of redesign. This approach employs low magnetic field strengths and flat or cylindrical sheet-metal parts, hence is suited to rapid optimization and scaling. Only refractory metal cathodes were used in this investigation.
2. Mapmaking for precision 21 cm cosmology
Dillon, Joshua S.; Tegmark, Max; Liu, Adrian; Ewall-Wice, Aaron; Hewitt, Jacqueline N.; Morales, Miguel F.; Neben, Abraham R.; Parsons, Aaron R.; Zheng, Haoxuan
2015-01-01
In order to study the "Cosmic Dawn" and the Epoch of Reionization with 21 cm tomography, we need to statistically separate the cosmological signal from foregrounds known to be orders of magnitude brighter. Over the last few years, we have learned much about the role our telescopes play in creating a putatively foreground-free region called the "EoR window." In this work, we examine how an interferometer's effects can be taken into account in a way that allows for the rigorous estimation of 21 cm power spectra from interferometric maps while mitigating foreground contamination and thus increasing sensitivity. This requires a precise understanding of the statistical relationship between the maps we make and the underlying true sky. While some of these calculations would be computationally infeasible if performed exactly, we explore several well-controlled approximations that make mapmaking and the calculation of map statistics much faster, especially for compact and highly redundant interferometers designed specifically for 21 cm cosmology. We demonstrate the utility of these methods and the parametrized trade-offs between accuracy and speed using one such telescope, the upcoming Hydrogen Epoch of Reionization Array, as a case study.
3. Polyhedral Serpentine Grains in CM Chondrites
NASA Technical Reports Server (NTRS)
Zega, Thomas J.; Garvie, Laurence A. J.; Dodony, Istvan; Stroud, Rhonda M.; Buseck, Peter R.
2005-01-01
CM chondrites are primitive rocks that experienced aqueous alteration in the early solar system. Their matrices and fine-grained rims (FGRs) sustained the effects of alteration, and the minerals within them hold clues to the aqueous reactions. Sheet silicates are an important product of alteration, and those of the serpentine group are abundant in the CM2 chondrites. Here we expand on our previous efforts to characterize the structure and chemistry of serpentines in CM chondrites and report results on a polyhedral form that is structurally similar to polygonal serpentine. Polygonal serpentine consists of tetrahedral (T) sheets joined to M(2+)-centered octahedral (O) sheets (where (M2+) is primarily Mg(2+) and Fe(2+)), which give rise to a 1:1 (TO) layered structure with a 0.7-nm layer periodicity. The structure is similar to chrysotile in that it consists of concentric lizardite layers wrapped around the fiber axis. However, unlike the rolled-up chrysotile, the tetrahedral sheets of the lizardite layers are periodically inverted and kinked, producing sectors. The relative angles between sectors result in 15- and 30-sided polygons in terrestrial samples.
4. ICD-10-CM/PCS: Transferring Knowledge from ICD-9-CM
PubMed Central
Sand, Jaime N.; Elison-Bowers, Patt
2013-01-01
The transition to ICD-10-CM/PCS has expanded educational opportunities for educators and trainers who are taking on the responsibility of training coders on the new system. Coding education currently faces multiple challenges in the areas of how to train the new workforce, what might be the most efficient method of providing that training, how much retraining of the current workforce with ICD-9-CM training will be required, and how to meet the national implementation deadline of 2014 in the most efficacious manner. This research sought to identify if there was a difference between a group of participants with no knowledge of ICD-9-CM and those with some knowledge of ICD-9-CM in scores on an ICD-10-CM/PCS quiz. Results indicate a difference, supporting the idea of knowledge transfer between the systems and providing additional insight into coding education. PMID:23861677
5. Detailed modelling of the 21-cm forest
Semelin, B.
2016-01-01
The 21-cm forest is a promising probe of the Epoch of Reionization. The local state of the intergalactic medium (IGM) is encoded in the spectrum of a background source (radio-loud quasars or gamma-ray burst afterglow) by absorption at the local 21-cm wavelength, resulting in a continuous and fluctuating absorption level. Small-scale structures (filaments and minihaloes) in the IGM are responsible for the strongest absorption features. The absorption can also be modulated on large scales by inhomogeneous heating and Wouthuysen-Field coupling. We present the results from a simulation that attempts to preserve the cosmological environment while resolving some of the small-scale structures (a few kpc resolution in a 50 h-1 Mpc box). The simulation couples the dynamics and the ionizing radiative transfer and includes X-ray and Lyman lines radiative transfer for a detailed physical modelling. As a result we find that soft X-ray self-shielding, Ly α self-shielding and shock heating all have an impact on the predicted values of the 21-cm optical depth of moderately overdense structures like filaments. A correct treatment of the peculiar velocities is also critical. Modelling these processes seems necessary for accurate predictions and can be done only at high enough resolution. As a result, based on our fiducial model, we estimate that LOFAR should be able to detect a few (strong) absorptions features in a frequency range of a few tens of MHz for a 20 mJy source located at z = 10, while the SKA would extract a large fraction of the absorption information for the same source.
6. BVRI CCD photometry of Omega Centauri
SciTech Connect
Alcaino, G.; Liller, W.
1987-12-01
Color-magnitude diagrams (CMDs) of V vs B-V, V vs V-I, and V vs B-I have been constructed based on 179 BVRI CCD frames of two adjoining 4x2.5-arcmin fields in Omega Cen (NGC 5139) obtained with the 1.54-m Danish La Silla telescope. The spread in the main sequences noted in the three CMDs indicates that the wide range in chemical composition among the evolved stars in this cluster persists as well in the unevolved stars. This result suggests that the abundance variations are primordial. A difference in magnitude between the turnoff and the horizontal branch of 3.8 + or - 0.15 is found which is greater than a previous value. 38 references.
7. Hubble Space Telescope Image of Omega Nebula
NASA Technical Reports Server (NTRS)
1999-01-01
In this sturning image provided by the Hubble Space Telescope (HST), the Omega Nebula (M17) resembles the fury of a raging sea, showing a bubbly ocean of glowing hydrogen gas and small amounts of other elements such as oxygen and sulfur. The nebula, also known as the Swan Nebula, is a hotbed of newly born stars residing 5,500 light-years away in the constellation Sagittarius. The wavelike patterns of gas have been sculpted and illuminated by a torrent of ultraviolet radiation from the young massive stars, which lie outside the picture to the upper left. The ultraviolet radiation is carving and heating the surfaces of cold hydrogen gas clouds. The warmed surfaces glow orange and red in this photograph. The green represents an even hotter gas that masks background structures. Various gases represented with color are: sulfur, represented in red; hydrogen, green; and oxygen blue.
8. Long Duration Backlighter Experiments at Omega
SciTech Connect
Reighard, A; Glendinning, S; Young, P; Hsing, W; Foord, M; Schneider, M; Lu, K; Dittrich, T; Wallace, R; Sorce, C
2008-05-01
We have successfully demonstrated a 7.5 ns-duration pinhole-apertured backlighter at the Omega laser facility. Pinhole-apertured point-projection backlighting for 8 ns will be useful for imaging evolving features in experiments at the National Ignition Facility. The backlighter consisted of a 20 {micro}m diameter pinhole in a 75 {micro}m thick Ta substrate separated from a Zn emitter (9 keV) by a 400 {micro}m thick high-density carbon piece. The carbon prevented the shock from the laser-driven surface from reaching the substrate before 8 ns and helped minimize x-ray ablation of the pinhole substrate. Grid wires in x-ray framing camera images of a gold grid have a source-limited resolution significantly smaller than the pinhole diameter due to the high aspect ratio of the pinhole, but do not become much smaller at late times.
9. [Antiinflammatory therapy in ostheoarthritis including omega 3 and omega 6 fatty acids].
PubMed
Dzielska-Olczak, Małgorzata; Nowak, Jerzy Z
2012-05-01
Osteoarthritis (ostheoarthrosis, OA) is characterized by progressive destruction of articular cartilage, remodeling of the periarticular bone and inflammation of the synovial membrane. In patients occur joints pain, impaired joints motion and disability. The results of many studies indicate an inflammation as foundation of this disease. The management of OA include a combination of pharmacological treatments and nonpharmacological interventions. Pharmacological treatments include used paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs) and chondroprotectives (glucosamine, chondroitin sulfate and so on). NSAIDs long-term use associated with serious adverse effects. OA symptoms are effectively reduced by nutrients such omega 3 and omega 6 fatty acids (PUFAs as EPA, DHA), which decrease the need for non-steroidal drugs and may less adverse events. They exerts, particularly EPA, anti-inflammatory effect, inhibit catabolic processes, stimulate the anabolic process in the cartilage in the joint. Many different evidence validate that omega 3 alleviate the progression of osteoarthritis and have exciting therapeutic potential for preventing cartilage degradation associated with chronic inflammatory in joints.
10. Isotope shifts in methane near 6000/cm
NASA Technical Reports Server (NTRS)
Fox, K.; Halsey, G. W.; Jennings, D. E.
1976-01-01
Isotope shifts for cleanly resolved vibrational-rotational absorption lines of CH4-12 and CH4-13 were measured by a 5-m focal length Littrow spectrometer in the 6000/cm range. The methane isotopes were held in separate absorption cells: 20 torr of CH4-13 in a 1-m cell, and 5 torr of CH4-12 in a White cell of 4-m optical path length. Measured shifts for the cleanly resolved singlets R(0), R(1), Q(1) and P(1) are summarized in tabular form.
11. An engineering model 30 cm ion thruster
NASA Technical Reports Server (NTRS)
Poeschel, R. L.; King, H. J.; Schnelker, D. E.
1973-01-01
Thruster development at Hughes Research Laboratories and NASA Lewis Research Center has brought the 30-cm mercury bombardment ion thruster to the state of an engineering model. This thruster has been designed to have sufficient internal strength for direct mounting on gimbals, to weigh 7.3 kg, to operate with a corrected overall efficiency of 71%, and to have 10,000 hours lifetime. Subassemblies, such as the ion optical system, isolators, etc., have been upgraded to meet launch qualification standards. This paper presents a summary of the design specifications and performance characteristics which define the interface between the thruster module and the remainder of the propulsion system.
12. A 30-cm diameter argon ion source
NASA Technical Reports Server (NTRS)
Sovey, J. S.
1976-01-01
A 30 cm diameter argon ion source was evaluated. Ion source beam currents up to 4a were extracted with ion energies ranging from 0.2 to 1.5 KeV. An ion optics scaling relation was developed for predicting ion beam extraction capability as a function of total extraction voltage, gas type, and screen grid open area. Ignition and emission characteristics of several hollow cathode geometries were assessed for purposes of defining discharge chamber and neutralizer cathodes. Also presented are ion beam profile characteristics which exhibit broad beam capability well suited for ion beam sputtering applications.
13. The Role of Omega-3 Fatty Acids in Diets.
PubMed
Gomez-Candela, C; Roldan Puchalt, M C; Palma Milla, S; Lopez Plaza, B; Bermejo, L
2015-01-01
The article is a summary of Dra. Carmen Gómez Candela's presentation at the Science in Nutrition 3rd International Congress in Milan, March 2014. The article covers omega-3 fatty acids use in different medical areas and several institutions' opinions in relation to the topic. Omega-3 acids are essential fatty acids. A certain amount of omega-3 is needed in our daily diet; however, the usual consumption is generally less than the recommended amount. Changes in dietary patterns in the course of history have led to deficit levels of omega-3 in the human body. Currently, there is increasing evidence of the benefits of omega-3 in different medical specialities. There are still some gaps regarding its role in illnesses such as dementia, psychiatric disorders, and inflammatory diseases. Nevertheless, stronger evidence is being proved in cardiovascular diseases and cancer. This article provides a reflection on possible ways to increase omega-3 daily consumption and the constraints associated with food with high contents of heavy metals, which, in turn, are also rich in omega-3s.
14. Modification of the omega-meson lifetime in nuclear matter.
PubMed
Kotulla, M; Trnka, D; Mühlich, P; Anton, G; Bacelar, J C S; Bartholomy, O; Bayadilov, D; Beloglazov, Y A; Bogendörfer, R; Castelijns, R; Crede, V; Dutz, H; Ehmanns, A; Elsner, D; Ewald, R; Fabry, I; Fuchs, M; Essig, K; Funke, Ch; Gothe, R; Gregor, R; Gridnev, A B; Gutz, E; Höffgen, S; Hoffmeister, P; Horn, I; Hössl, J; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Klein, Frank; Klein, Fritz; Klempt, E; Konrad, M; Kopf, B; Krusche, B; Langheinrich, J; Löhner, H; Lopatin, I V; Lotz, J; Lugert, S; Menze, D; Messchendorp, J G; Mertens, T; Metag, V; Mosel, U; Nanova, M; Novotny, R; Ostrick, M; Pant, L M; van Pee, H; Pfeiffer, M; Roy, A; Radkov, A; Schadmand, S; Schmidt, Ch; Schmieden, H; Schoch, B; Shende, S; Suft, G; Sumachev, V V; Szczepanek, T; Süle, A; Thoma, U; Varma, R; Walther, D; Weinheimer, Ch; Wendel, Ch
2008-05-16
Information on hadron properties in the nuclear medium has been derived from the photoproduction of omega mesons on the nuclei C, Ca, Nb, and Pb using the Crystal Barrel/TAPS detector at the ELSA tagged photon facility in Bonn. The dependence of the omega-meson cross section on the nuclear mass number has been compared with three different types of models: a Glauber analysis, a Boltzmann-Uehling-Uhlenbeck analysis of the Giessen theory group, and a calculation by the Valencia theory group. In all three cases, the inelastic omega width is found to be 130-150 MeV/c(2) at normal nuclear matter density for an average 3-momentum of 1.1 GeV/c. In the rest frame of the omega meson, this inelastic omega width corresponds to a reduction of the omega lifetime by a factor approximately 30. For the first time, the momentum dependent omegaN cross section has been extracted from the experiment and is in the range of 70 mb.
15. Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability
PubMed Central
Christensen, Jeppe Hagstrup
2011-01-01
Omega-3 polyunsaturated fatty acids (PUFA) may modulate autonomic control of the heart because omega-3 PUFA is abundant in the brain and other nervous tissue as well as in cardiac tissue. This might partly explain why omega-3 PUFA offer some protection against sudden cardiac death (SCD). The autonomic nervous system is involved in the pathogenesis of SCD. Heart rate variability (HRV) can be used as a non-invasive marker of cardiac autonomic control and a low HRV is a predictor for SCD and arrhythmic events. Studies on HRV and omega-3 PUFA have been performed in several populations such as patients with ischemic heart disease, patients with diabetes mellitus, patients with chronic renal failure, and in healthy subjects as well as in children. The studies have demonstrated a positive association between cellular content of omega-3 PUFA and HRV and supplementation with omega-3 PUFA seems to increase HRV which could be a possible explanation for decreased risk of arrhythmic events and SCD sometimes observed after omega-3 PUFA supplementation. However, the results are not consistent and further research is needed. PMID:22110443
16. Production and Decay of Omega_c^0
SciTech Connect
Aubert, B
2007-03-21
We present an analysis of inclusive {Omega}{sub c}{sup 0} baryon production and decays in 230.5 fb{sup -1} of data recorded with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the Stanford Linear Accelerator Center. {Omega}{sub c}{sup 0} baryons are reconstructed in four final states ({Omega}{sup -}{pi}{sup +}, {Omega}{sup -}{pi}{sup +}{pi}{sup 0}, {Omega}{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -}, {Xi}{sup -}K{sup -}{pi}{sup +}{pi}{sup +}) and the ratios of branching fractions for these final states are measured. We also measure the momentum spectrum of the {Omega}{sub c}{sup 0} baryons in the e{sup +}e{sup -} center-of-mass frame. From the spectrum, they observe {Omega}{sub c}{sup 0} production from B decays and in c{bar c} events, and extract the two rates of production.
17. New portrait of Omega Nebula's glistening watercolours
2009-07-01
The Omega Nebula, sometimes called the Swan Nebula, is a dazzling stellar nursery located about 5500 light-years away towards the constellation of Sagittarius (the Archer). An active star-forming region of gas and dust about 15 light-years across, the nebula has recently spawned a cluster of massive, hot stars. The intense light and strong winds from these hulking infants have carved remarkable filigree structures in the gas and dust. When seen through a small telescope the nebula has a shape that reminds some observers of the final letter of the Greek alphabet, omega, while others see a swan with its distinctive long, curved neck. Yet other nicknames for this evocative cosmic landmark include the Horseshoe and the Lobster Nebula. Swiss astronomer Jean-Philippe Loys de Chéseaux discovered the nebula around 1745. The French comet hunter Charles Messier independently rediscovered it about twenty years later and included it as number 17 in his famous catalogue. In a small telescope, the Omega Nebula appears as an enigmatic ghostly bar of light set against the star fields of the Milky Way. Early observers were unsure whether this curiosity was really a cloud of gas or a remote cluster of stars too faint to be resolved. In 1866, William Huggins settled the debate when he confirmed the Omega Nebula to be a cloud of glowing gas, through the use of a new instrument, the astronomical spectrograph. In recent years, astronomers have discovered that the Omega Nebula is one of the youngest and most massive star-forming regions in the Milky Way. Active star-birth started a few million years ago and continues through today. The brightly shining gas shown in this picture is just a blister erupting from the side of a much larger dark cloud of molecular gas. The dust that is so prominent in this picture comes from the remains of massive hot stars that have ended their brief lives and ejected material back into space, as well as the cosmic detritus from which future suns form. The
18. Fuel elements of research reactor CM
SciTech Connect
Kozlov, A.V.; Morozov, A.V.; Vatulin, A.V.; Ershov, S.A.
2013-07-01
In 1961 the CM research reactor was commissioned at the Research Institute of Atomic Reactors (Dimitrovgrad, Russia), it was intended to carry on investigations and the production of transuranium nuclides. The reactor is of a tank type. Original fuel assembly contained plate fuels that were spaced with vanes and corrugated bands. Nickel was used as a cladding material, fuel meat was produced from UO{sub 2} + electrolytic nickel composition. Fuel plates have been replaced by self-spacing cross-shaped dispersion fuels clad in stainless steel. In 2005 the reactor was updated. The purpose of this updating was to increase the quantity of irradiation channels in the reactor core and to improve the neutron balance. The updating was implemented at the expense of 20 % reduction in the quantity of fuel elements in the core which released a space for extra channels and decreased the mass of structural materials in the core. The updated reactor is loaded with modified standard fuel elements with 20 % higher uranium masses. At the same time stainless steel in fuel assembly shrouds was substituted by zirconium alloy. Today in progress are investigations and work to promote the second stage of reactor updating that involve developments of cross-shaped fuel elements having low neutron absorption matrix materials. This article gives an historical account of the design and main technical changes that occurred for the CM reactor since its commissioning.
19. Redundant Array Configurations for 21 cm Cosmology
Dillon, Joshua S.; Parsons, Aaron R.
2016-08-01
Realizing the potential of 21 cm tomography to statistically probe the intergalactic medium before and during the Epoch of Reionization requires large telescopes and precise control of systematics. Next-generation telescopes are now being designed and built to meet these challenges, drawing lessons from first-generation experiments that showed the benefits of densely packed, highly redundant arrays—in which the same mode on the sky is sampled by many antenna pairs—for achieving high sensitivity, precise calibration, and robust foreground mitigation. In this work, we focus on the Hydrogen Epoch of Reionization Array (HERA) as an interferometer with a dense, redundant core designed following these lessons to be optimized for 21 cm cosmology. We show how modestly supplementing or modifying a compact design like HERA’s can still deliver high sensitivity while enhancing strategies for calibration and foreground mitigation. In particular, we compare the imaging capability of several array configurations, both instantaneously (to address instrumental and ionospheric effects) and with rotation synthesis (for foreground removal). We also examine the effects that configuration has on calibratability using instantaneous redundancy. We find that improved imaging with sub-aperture sampling via “off-grid” antennas and increased angular resolution via far-flung “outrigger” antennas is possible with a redundantly calibratable array configuration.
20. THE METALLICITY OF THE CM DRACONIS SYSTEM
SciTech Connect
Terrien, Ryan C.; Fleming, Scott W.; Mahadevan, Suvrath; Deshpande, Rohit; Bender, Chad F.; Ramsey, Lawrence W.; Feiden, Gregory A.
2012-11-20
The CM Draconis system comprises two eclipsing mid-M dwarfs of nearly equal mass in a 1.27 day orbit. This well-studied eclipsing binary has often been used for benchmark tests of stellar models, since its components are among the lowest mass stars with well-measured masses and radii ({approx}< 1% relative precision). However, as with many other low-mass stars, non-magnetic models have been unable to match the observed radii and effective temperatures for CM Dra at the 5%-10% level. To date, the uncertain metallicity of the system has complicated comparison of theoretical isochrones with observations. In this Letter, we use data from the SpeX instrument on the NASA Infrared Telescope Facility to measure the metallicity of the system during primary and secondary eclipses, as well as out of eclipse, based on an empirical metallicity calibration in the H and K near-infrared (NIR) bands. We derive an [Fe/H] = -0.30 {+-} 0.12 that is consistent across all orbital phases. The determination of [Fe/H] for this system constrains a key dimension of parameter space when attempting to reconcile model isochrone predictions and observations.
1. Design study of large area 8 cm x 8 cm wrapthrough cells for space station
NASA Technical Reports Server (NTRS)
Garlick, George F. J.; Lillington, David R.
1987-01-01
The design of large area silicon solar cells for the projected NASA space station is discussed. It is based on the NASA specification for the cells which calls for an 8 cm by 8 cm cell of wrapthrough type with gridded back contacts. The beginning of life (BOL) power must be 1.039 watts per cell or larger and maximum end of life (EOL) after 10 years in the prescribed orbit under an equivalent 1MeV electron radiation damage fluence of 5 times 10 to the 13th power e/square cm. On orbit efficiency is to be optimized by a low thermal absorptance goal (thermal alpha) of .63.
2. Aliphatic Amines in Antarctic CR2, CM2, and CM1/2 Carbonaceous Chondrites
NASA Technical Reports Server (NTRS)
Aponte, Jose C.; McLain, Hannah L.; Dworkin, Jason P.; Elsila, Jamie E.
2016-01-01
Meteoritic water-soluble organic compounds provide a unique record of the processes that occurred during the formation of the solar system and the chemistry preceding the origins of life on Earth. We have investigated the molecular distribution, compound-specific delta13C isotopic ratios and enantiomeric compositions of aliphatic monoamines present in the hot acid-water extracts of the carbonaceous chondrites LAP 02342 (CR2), GRA 95229 (CR2), LON 94101 (CM2), LEW 90500 (CM2), and ALH 83100 (CM1/2). Analyses of the concentration of monoamines in these meteorites revealed: (a) the CR2 chondrites studied here contain higher concentrations of monoamines relative to the analyzed CM2 chondrites; (b) the concentration of monoamines decreases with increasing carbon number; and (c) isopropylamine is the most abundant monoamine in these CR2 chondrites, while methylamine is the most abundant amine species in these CM2 and CM1/2 chondrites. The delta13C values of monoamines in CR2 chondrite do not correlate with the number of carbon atoms; however, in CM2 and CM1/2 chondrites, the 13C enrichment decreases with increasing monoamine carbon number. The delta13C values of methylamine in CR2 chondrites ranged from -1 to +10per mille, while in CM2 and CM1/2 chondrites the delta13C values of methylamine ranged from +41 to +59per mille. We also observed racemic compositions of sec-butylamine, 3-methyl-2-butylamine, and sec-pentylamine in the studied carbonaceous chondrites. Additionally, we compared the abundance and delta13C isotopic composition of monoamines to those of their structurally related amino acids. We found that monoamines are less abundant than amino acids in CR2 chondrites, with the opposite being true in CM2 and CM1/2 chondrites. We used these collective data to evaluate different primordial synthetic pathways for monoamines in carbonaceous chondrites and to understand the potential common origins these molecules may share with meteoritic amino acids.
3. Aliphatic amines in Antarctic CR2, CM2, and CM1/2 carbonaceous chondrites
Aponte, José C.; McLain, Hannah L.; Dworkin, Jason P.; Elsila, Jamie E.
2016-09-01
Meteoritic water-soluble organic compounds provide a unique record of the processes that occurred during the formation of the solar system and the chemistry preceding the origins of life on Earth. We have investigated the molecular distribution, compound-specific δ13C isotopic ratios and enantiomeric compositions of aliphatic monoamines present in the hot acid-water extracts of the carbonaceous chondrites LAP 02342 (CR2), GRA 95229 (CR2), LON 94101 (CM2), LEW 90500 (CM2), and ALH 83100 (CM1/2). Analyses of the concentration of monoamines in these meteorites revealed: (a) the CR2 chondrites studied here contain higher concentrations of monoamines relative to the analyzed CM2 chondrites; (b) the concentration of monoamines decreases with increasing carbon number; and (c) isopropylamine is the most abundant monoamine in these CR2 chondrites, while methylamine is the most abundant amine species in these CM2 and CM1/2 chondrites. The δ13C values of monoamines in CR2 chondrite do not correlate with the number of carbon atoms; however, in CM2 and CM1/2 chondrites, the 13C enrichment decreases with increasing monoamine carbon number. The δ13C values of methylamine in CR2 chondrites ranged from -1 to +10‰, while in CM2 and CM1/2 chondrites the δ13C values of methylamine ranged from +41 to +59‰. We also observed racemic compositions of sec-butylamine, 3-methyl-2-butylamine, and sec-pentylamine in the studied carbonaceous chondrites. Additionally, we compared the abundance and δ13C isotopic composition of monoamines to those of their structurally related amino acids. We found that monoamines are less abundant than amino acids in CR2 chondrites, with the opposite being true in CM2 and CM1/2 chondrites. We used these collective data to evaluate different primordial synthetic pathways for monoamines in carbonaceous chondrites and to understand the potential common origins these molecules may share with meteoritic amino acids.
4. Search for lepton flavor violating decays tau+/--->l+/-omega.
PubMed
2008-02-22
A search for lepton flavor violating decays of a tau to a lighter-mass charged lepton and an omega vector meson is performed using 384.1 fb(-1) of e(+)e(-) annihilation data collected with the BABAR detector at the Stanford Linear Accelerator Center PEP-II storage ring. No signal is found, and the upper limits on the branching ratios are determined to be B(tau(+/-)-->e;{+/-}omega)<1.1 x10 (-7) and B(tau(+/-)-->micro(+/-)omega)<1.0 x 10(-7) at 90% confidence level.
5. A Comparison of Composite Reliability Estimators: Coefficient Omega Confidence Intervals in the Current Literature
ERIC Educational Resources Information Center
2016-01-01
Coefficient omega and alpha are both measures of the composite reliability for a set of items. Unlike coefficient alpha, coefficient omega remains unbiased with congeneric items with uncorrelated errors. Despite this ability, coefficient omega is not as widely used and cited in the literature as coefficient alpha. Reasons for coefficient omega's…
6. Large aperture cube corner interferometer with a resolution of 0.001 cm(-1).
PubMed
Kauppinen, J; Horneman, V M
1991-06-20
The interferometer of the Fourier transform spectrometer at the University of Oulu has been modified so that the maximum instrumental resolution is better than 10(-3) cm(-1). The resolution of the previous interferometer was 4.5 x 10(-3) cm(-1). The present interferometer consists of large cube corner mirrors and a large Mylar beam splitter. Each corner mirror has been made with three flat mirrors on an adjustable supporting frame. The interferometer was already in practical use in 1985. The first spectra (H(2)O, CO(2), N(2)O, OCS) recorded on this interferometer have been presented in HANDBOOK OF INFRARED STANDARDS WITH SPECTRAL MAPS AND TRANSITION ASSIGNMENTS BETWEEN 3 AND 2600 microm, G. Guelachvili and K. Narahari Rao, Eds. (Academic, New York, 1986).
7. Anti-inflammatory Effects of Omega 3 and Omega 6 Polyunsaturated Fatty Acids in Cardiovascular Disease and Metabolic Syndrome.
PubMed
Tortosa-Caparrós, Esther; Navas-Carrillo, Diana; Marín, Francisco; Orenes-Piñero, Esteban
2016-01-08
A lipid excess produces a systemic inflammation process due to tumor necrosis factor-α, interleukin-6 and C-reactive protein synthesis. Simultaneously, this fat excess promotes the appearance of insulin resistance. All this contributes to the development of atherosclerosis and increases the risk of cardiovascular diseases. On the other hand, polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid and docosahexaenoic acid (omega 3), and arachidonic acid (omega 6) have shown anti-inflammatory properties. Lately, an inverse relationship between omega-3 fatty acids, inflammation, obesity and cardiovascular diseases has been demonstrated. To check fatty acids effect, the levels of some inflammation biomarkers have been analyzed. Leptin, adiponectin and resistin represent a group of hormones associated with the development of cardiovascular diseases, obesity, type 2 diabetes mellitus and insulin resistance and are modified in obese-overweight people comparing to normal weight people. Omega-3 PUFAs have been shown to decrease the production of inflammatory mediators, having a positive effect in obesity and diabetes mellitus type-2. Moreover, they significantly decrease the appearance of cardiovascular disease risk factors. Regarding omega-6 PUFA, there is controversy whether their effects are pro- or anti-inflammatory. The aim of this manuscript is to provide a comprehensive overview about the role of omega-3 and omega-6 PUFAs in cardiovascular diseases and metabolic syndrome.
8. Improving the hot-spot pressure and demonstrating ignition hydrodynamic equivalence in cryogenic deuterium tritium implosions on OMEGA
SciTech Connect
Goncharov, V. N.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Follett, R. K.; Forrest, C. J.; Froula, D. H.; Yu. Glebov, V.; Harding, D. R.; Henchen, R. J.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H.; Kessler, T. J.; Kosc, T. Z.; Loucks, S. J.; Marozas, J. A.; Marshall, F. J.; Maximov, A. V.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Nora, R.; Radha, P. B.; Regan, S. P.; Seka, W.; Shmayda, W. T.; Short, R.W.; Shvydky, A.; Skupsky, S.; Stoeckl, C.; Yaakobi, B.; Frenje, J. A.; Gatu-Johnson, M.; Petrasso, R. D.; Casey, D. T.
2014-05-01
Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of α ≅ 4, an implosion velocity of 3.8 × 10⁷ cm/s, and a laser intensity of ~10¹⁵ W/cm². These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.
9. Fatty acid composition in major depression: decreased omega 3 fractions in cholesteryl esters and increased C20: 4 omega 6/C20:5 omega 3 ratio in cholesteryl esters and phospholipids.
PubMed
Maes, M; Smith, R; Christophe, A; Cosyns, P; Desnyder, R; Meltzer, H
1996-04-26
Recently, there were some reports that major depression may be accompanied by alterations in serum total cholesterol, cholesterol ester and omega 3 essential fatty acid levels and by an increased C20: 4 omega 6/C20: 5 omega 3, i.e., arachidonic acid/eicosapentaenoic, ratio. The present study aimed to examine fatty acid composition of serum cholesteryl esters and phospholipids in 36 major depressed, 14 minor depressed and 24 normal subjects. Individual saturated (e.g., C14:0; C16:0, C18:0) and unsaturated (e.g., C18:1, C18:2, C20:4) fatty acids in phospholipid and cholesteryl ester fractions were assayed and the sums of the percentages of omega 6 and omega 3, saturated, branched chain and odd chain fatty acids, monoenes as well as the ratios omega 6/omega 3 and C20:4 omega 6/C20:5 omega 3 were calculated. Major depressed subjects had significantly higher C20:4 omega 6/C20:5 omega 3 ratio in both serum cholesteryl esters and phospholipids and a significantly increased omega 6/omega 3 ratio in cholesteryl ester fraction than healthy volunteers and minor depressed subjects. Major depressed subjects had significantly lower C18:3 omega 3 in cholesteryl esters than normal controls. Major depressed subjects showed significantly lower total omega 3 polyunsaturated fatty acids in cholesteryl esters and significantly lower C20:5 omega 3 in serum cholesteryl esters and phospholipids than minor depressed subjects and healthy controls. These findings suggest an abnormal intake or metabolism of essential fatty acids in conjunction with decreased formation of cholesteryl esters in major depression.
10. The 30-cm ion thruster power processor
NASA Technical Reports Server (NTRS)
Herron, B. G.; Hopper, D. J.
1978-01-01
A power processor unit for powering and controlling the 30 cm Mercury Electron-Bombardment Ion Thruster was designed, fabricated, and tested. The unit uses a unique and highly efficient transistor bridge inverter power stage in its implementation. The system operated from a 200 to 400 V dc input power bus, provides 12 independently controllable and closely regulated dc power outputs, and has an overall power conditioning capacity of 3.5 kW. Protective circuitry was incorporated as an integral part of the design to assure failure-free operation during transient and steady-state load faults. The implemented unit demonstrated an electrical efficiency between 91.5 and 91.9 at its nominal rated load over the 200 to 400 V dc input bus range.
11. Evaluation of Argonne 9-cm and 10-cm Annular Centrifugal Contactors for SHINE Solution Processing
SciTech Connect
Wardle, Kent E.; Pereira, Candido; Vandegrift, George
2015-02-01
Work is in progress to evaluate the SHINE Medical Technologies process for producing Mo-99 for medical use from the fission of dissolved low-enriched uranium (LEU). This report addresses the use of Argonne annular centrifugal contactors for periodic treatment of the process solution. In a letter report from FY 2013, Pereira and Vandegrift compared the throughput and physical footprint for the two contactor options available from CINC Industries: the V-02 and V-05, which have rotor diameters of 5 cm and 12.7 cm, respectively. They suggested that an intermediately sized “Goldilocks” contactor might provide a better balance between throughput and footprint to meet the processing needs for the uranium extraction (UREX) processing of the SHINE solution to remove undesired fission products. Included with the submission of this letter report are the assembly drawings for two Argonne-design contactors that are in this intermediate range—9-cm and 10-cm rotors, respectively. The 9-cm contactor (drawing number CE-D6973A, stamped February 15, 1978) was designed as a single-stage unit and built and tested in the late 1970s along with other size units, both smaller and larger. In subsequent years, a significant effort to developed annular centrifugal contactors was undertaken to support work at Hanford implementing the transuranic extraction (TRUEX) process. These contactors had a 10-cm rotor diameter and were fully designed as multistage units with four stages per assembly (drawing number CMT-E1104, stamped March 14, 1990). From a technology readiness perspective, these 10-cm units are much farther ahead in the design progression and, therefore, would require significantly less re-working to make them ready for UREX deployment. Additionally, the overall maximum throughput of ~12 L/min is similar to that of the 9-cm unit (10 L/min), and the former could be efficiently operated over much of the same range of throughput. As a result, only the 10-cm units are considered here
12. Homoclinic {omega}-explosion and domains of hyperbolicity
SciTech Connect
Sten'kin, O V; Shil'nikov, L P
1998-04-30
The existence of domains of hyperbolicity is proved for general one-parameter families of multidimensional systems that undergo a homoclinic {omega}-explosion and the structure of the hyperbolic sets is studied for such families.
13. Mitigating Sleep Loss: Assessment of Omega-3 Fatty Acids
DTIC Science & Technology
2011-04-15
from EEG and cytokines support the hypothesis that the improved perfroamnce is due to reduced inflammatory activity with Omega supplementation . These...treatment found that Omega-3 supplementation improved this metric. 10 | P a g e Distribution Statement A: Approved for public release... supplementation led to significantly better accuracy on both parameters for both tasks, Fs (8,219) > 2.79, ps < .01, but only marginally faster
14. Ambiguity resolution in systems using Omega for position location
NASA Technical Reports Server (NTRS)
Frenkel, G.; Gan, D. G.
1974-01-01
The lane ambiguity problem prevents the utilization of the Omega system for many applications such as locating buoys and balloons. The method of multiple lines of position introduced herein uses signals from four or more Omega stations for ambiguity resolution. The coordinates of the candidate points are determined first through the use of the Newton iterative procedure. Subsequently, a likelihood function is generated for each point, and the ambiguity is resolved by selecting the most likely point. The method was tested through simulation.
15. MANGANESE ABUNDANCES IN THE GLOBULAR CLUSTER {omega} CENTAURI
SciTech Connect
Cunha, Katia; Smith, Verne V.; Bergemann, Maria; Suntzeff, Nicholas B.; Lambert, David L.
2010-07-01
We present manganese abundances in 10 red giant members of the globular cluster {omega} Centauri; eight stars are from the most metal-poor population (RGB MP and RGB MInt1) while two targets are members of the more metal-rich groups (RGB MInt2 and MInt3). This is the first time Mn abundances have been studied in this peculiar stellar system. The LTE values of [Mn/Fe] in {omega} Cen overlap those of Milky Way stars in the metal-poor {omega} Cen populations ([Fe/H] {approx}-1.5 to -1.8), however unlike what is observed in Milky Way halo and disk stars, [Mn/Fe] declines in the two more metal-rich RGB MInt2 and MInt3 targets. Non-LTE calculations were carried out in order to derive corrections to the LTE Mn abundances. The non-LTE results for {omega} Cen in comparison with the non-LTE [Mn/Fe] versus [Fe/H] trend obtained for the Milky Way confirm and strengthen the conclusion that the manganese behavior in {omega} Cen is distinct. These results suggest that low-metallicity supernovae (with metallicities {<=} -2) of either Type II or Type Ia dominated the enrichment of the more metal-rich stars in {omega} Cen. The dominance of low-metallicity stars in the chemical evolution of {omega} Cen has been noted previously in the s-process elements where enrichment from metal-poor asymptotic giant branch stars is indicated. In addition, copper, which also has metallicity-dependent yields, exhibits lower values of [Cu/Fe] in the RGB MInt2 and MInt3 {omega} Cen populations.
16. Omega-3 Fatty Acids and Skeletal Muscle Health.
PubMed
Jeromson, Stewart; Gallagher, Iain J; Galloway, Stuart D R; Hamilton, D Lee
2015-11-19
Skeletal muscle is a plastic tissue capable of adapting and mal-adapting to physical activity and diet. The response of skeletal muscle to adaptive stimuli, such as exercise, can be modified by the prior nutritional status of the muscle. The influence of nutrition on skeletal muscle has the potential to substantially impact physical function and whole body metabolism. Animal and cell based models show that omega-3 fatty acids, in particular those of marine origin, can influence skeletal muscle metabolism. Furthermore, recent human studies demonstrate that omega-3 fatty acids of marine origin can influence the exercise and nutritional response of skeletal muscle. These studies show that the prior omega-3 status influences not only the metabolic response of muscle to nutrition, but also the functional response to a period of exercise training. Omega-3 fatty acids of marine origin therefore have the potential to alter the trajectory of a number of human diseases including the physical decline associated with aging. We explore the potential molecular mechanisms by which omega-3 fatty acids may act in skeletal muscle, considering the n-3/n-6 ratio, inflammation and lipidomic remodelling as possible mechanisms of action. Finally, we suggest some avenues for further research to clarify how omega-3 fatty acids may be exerting their biological action in skeletal muscle.
17. Study of the decay B0bar -> D* omega pi
SciTech Connect
Aubert, B.
2006-04-24
We report on a study of the decay {bar B}{sup 0} {yields} D*{sup +}{omega}{pi}{sup -} with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232 million B{bar B} decays, we measure the branching fraction {Beta}({bar B}{sup 0} {yields} D*{sup +}{omega}{pi}{sup -}) = (2.88 {+-} 0.21(stat.) {+-} 0.31(syst.)) x 10{sup -3}. We study the invariant mass spectrum of the {omega}{pi}{sup -} system in this decay. This spectrum is in good agreement with expectations based on factorization and the measured spectrum in {tau}{sup -} {yields} {omega}{pi}{sup -} {nu}{sub {tau}}. We also measure the polarization of the D*{sup +} as a function of the {omega}{pi}{sup -} mass. In the mass region 1.1 to 1.9 GeV we measure the fraction of longitudinal polarization of the D*{sup +} to be {Lambda}{sub L}/{Lambda} = 0.654 {+-} 0.042(stat.) {+-} 0.016(syst.). This is in agreement with the expectations from heavy-quark effective theory and factorization assuming that the decay proceeds as {bar B}{sup 0} {yields} D*{sup +}{rho}(1450), {rho}(1450) {yields} {omega}{pi}{sup -}.
18. The role of omega-3 fatty acids in mood disorders.
PubMed
Stahl, Lauren A; Begg, Denovan P; Weisinger, Richard S; Sinclair, Andrew J
2008-01-01
Research has established that docosahexaenoic acid (DHA), a long-chain omega-3 polyunsaturated fatty acid (PUFA), plays a fundamental role in brain structure and function. Epidemiological and cross-sectional studies have also identified a role for long-chain omega-3 PUFA, which includes DHA, eicosapentaenoic acid, and docosapentaenoic acid, in the etiology of depression. In the past ten years, there have been 12 intervention studies conducted using various preparations of longchain omega-3 PUFA in unipolar and bipolar depression. The majority of these studies administered long-chain omega-3 PUFA as an adjunct therapy. The studies have been conducted over 4 to 16 weeks of intervention and have often included small cohorts. In four out of the seven studies conducted in depressed individuals and in two out of the five studies in bipolar patients, individuals have reported a positive outcome following supplementation with ethyl-eicosapentaenoic acid or fish oil containing long-chain omega-3 PUFA. In the three trials that researched the influence of DHA-rich preparations, no significant effects were reported. The mechanisms that have been invoked to account for the benefits of long-chain omega-3 PUFA in depression include reductions in prostaglandins derived from arachidonic acid, which lead to decreased brain-derived neurotrophic factor levels and/or alterations in blood flow to the brain.
19. Omega-3 fatty acids: cardiovascular benefits, sources and sustainability.
PubMed
Lee, John H; O'Keefe, James H; Lavie, Carl J; Harris, William S
2009-12-01
The evidence for the cardioprotective nature of omega-3 fatty acids is abundant, and currently available data indicate that patients with known coronary heart disease should consume at least 1 g daily of long-chain omega-3 fatty acids from either oily fish or fish-oil supplements, and that individuals without disease should consume at least 250-500 mg daily. However, this area of research poses two questions. Firstly, which is the best source of omega-3 fatty acids-fish or fish-oil supplements? Secondly, are recommendations for omega-3 supplementation warranted in view of the rapid depletion of world fish stocks? The argument that eating fish is better than taking fish-oil supplements stems from the fact that several important nutrients, such as vitamin D, selenium, and antioxidants, are missing from the supplements. However, three major prevention trials have clearly indicated that omega-3 fatty acid capsules confer cardiovascular benefits and, therefore, that both are cardioprotective. Sustainable sources of omega-3 fatty acids will need to be identified if long-term cardiovascular risk reduction is to be achieved at the population level.
20. Engineering model 8-cm thruster subsystem
NASA Technical Reports Server (NTRS)
Herron, B. G.; Hyman, J.; Hopper, D. J.; Williamson, W. S.; Dulgeroff, C. R.; Collett, C. R.
1978-01-01
An Engineering Model (EM) 8 cm Ion Thruster Propulsion Subsystem was developed for operation at a thrust level 5 mN (1.1 mlb) at a specific impulse 1 sub sp = 2667 sec with a total system input power P sub in = 165 W. The system dry mass is 15 kg with a mercury-propellant-reservoir capacity of 8.75 kg permitting uninterrupted operation for about 12,500 hr. The subsystem can be started from a dormant condition in a time less than or equal to 15 min. The thruster has a design lifetime of 20,000 hr with 10,000 startup cycles. A gimbal unit is included to provide a thrust vector deflection capability of + or - 10 degrees in any direction from the zero position. The EM subsystem development program included thruster optimization, power-supply circuit optimization and flight packaging, subsystem integration, and subsystem acceptance testing including a cyclic test of the total propulsion package.
1. The 15 cm diameter ion thruster research
NASA Technical Reports Server (NTRS)
Wilbur, P. J.
1974-01-01
The startup reliability of a 15 cm diameter mercury bombardment ion thruster which employs a pulsed high voltage tickler electrode on the main and neutralizer cathodes is examined. Startup of the thruster is achieved 100% of the time on the main cathode and 98.7% of the time on the neutralizer cathode over a 3640 cycle test. The thruster was started from a 20 C initial condition and operated for an hour at a 600 mA beam current. An energy efficiency of 75% and a propellant utilization efficiency of 77% was achieved over the complete cycle. The effect of a single cusp magnetic field thruster length on its performance is discussed. Guidelines are formulated for the shaping of magnetic field lines in thrusters. A model describing double ion production in mercury discharges is presented. The production route is shown to occur through the single ionic ground state. Photographs of the interior of an operating-hollow cathode are presented. A cathode spot is shown to be present if the cathode is free of low work-function surfaces. The spot is observed if a low work-function oxide coating is applied to the cathode insert. Results show that low work-function oxide coatings tend to migrate during thruster operation.
2. Source geometric considerations for OMEGA Dante measurements.
PubMed
May, M J; Patterson, J R; Sorce, C; Widmann, K; Fournier, K B; Perez, F
2012-10-01
The Dante is a 15 channel filtered diode array which is installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The system yields the spectrally and temporally resolved radiation flux from 50 eV to 10 keV from various targets (i.e., Hohlraum, gas pipes, etc.). The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and an unfold algorithm applied to the recorded voltages from each channel. The unfold algorithm assumes an emitting source that is spatially uniform and has a constant area as a function of photon energy. The emitting x-ray source is usually considered to be the laser entrance hole (LEH) of a given diameter for Hohlraum type targets or the effective wall area of high conversion efficiency K-shell type targets. This assumption can be problematic for several reasons. High intensity regions or "hot spots" in the x-ray are observed where the drive laser beams strike the target. The "hot spots" create non-uniform emission seen by the Dante. Additionally, thinned walled (50 μm) low-Z targets (C(22)H(10)N(2)O(5)) have an energy dependent source size since the target's walls will be fully opaque for low energies (E < 2-3 keV) yet fully transmissive at higher energies. Determining accurate yields can be challenging for these types of targets. Discussion and some analysis will be presented.
3. KULL Simulations of OMEGA Radiation Flow Experiments
Kallman, J.; MacLaren, S.; Baker, K.; Amala, P.; Lewis, K.; Zika, M.
2012-10-01
The problem of radiation flow in a right circular cylinder is of interest for the verification and validation of radiation codes, which utilize several mechanisms for determining radiation transport (diffusion, discrete ordinates, and Monte Carlo). This flow is analogous to free molecular flow in a similar geometry.footnotetextE. Garelis and T.E. Wainwright. Phys. Fluids. 16, 4 (1973) A series of experiments were conducted on the OMEGA laser in cases with a low-density heated cylindrical wall. The experiments consisted of a 1.6 mm diameter gold hohlraum containing an on-axis 700 μm diameter SiO2 cylinder contained in an 80 μm thick carbon foam tube. Five shots panning three test cases were used: the nominal geometry described above (heated wall), the carbon tube replaced with solid gold, and a gold cap placed on the laser end of the cylinder assembly to block axial radiation flow. Simulations of each experimental target type were run with the KULL radiation code, and were used to compare the different radiation transport packages in KULL by employing synthetic diagnostics to match the experimental DANTE cavity radiation temperature time history and soft x-ray images taken by a streak camera imaging the far end of the hohlraum.
4. Uncertainty analysis technique for OMEGA Dante measurementsa)
May, M. J.; Widmann, K.; Sorce, C.; Park, H.-S.; Schneider, M.
2010-10-01
The Dante is an 18 channel x-ray filtered diode array which records the spectrally and temporally resolved radiation flux from various targets (e.g., hohlraums, etc.) at x-ray energies between 50 eV and 10 keV. It is a main diagnostic installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The absolute flux is determined from the photometric calibration of the x-ray diodes, filters and mirrors, and an unfold algorithm. Understanding the errors on this absolute measurement is critical for understanding hohlraum energetic physics. We present a new method for quantifying the uncertainties on the determined flux using a Monte Carlo parameter variation technique. This technique combines the uncertainties in both the unfold algorithm and the error from the absolute calibration of each channel into a one sigma Gaussian error function. One thousand test voltage sets are created using these error functions and processed by the unfold algorithm to produce individual spectra and fluxes. Statistical methods are applied to the resultant set of fluxes to estimate error bars on the measurements.
5. Uncertainty analysis technique for OMEGA Dante measurements.
PubMed
May, M J; Widmann, K; Sorce, C; Park, H-S; Schneider, M
2010-10-01
The Dante is an 18 channel x-ray filtered diode array which records the spectrally and temporally resolved radiation flux from various targets (e.g., hohlraums, etc.) at x-ray energies between 50 eV and 10 keV. It is a main diagnostic installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The absolute flux is determined from the photometric calibration of the x-ray diodes, filters and mirrors, and an unfold algorithm. Understanding the errors on this absolute measurement is critical for understanding hohlraum energetic physics. We present a new method for quantifying the uncertainties on the determined flux using a Monte Carlo parameter variation technique. This technique combines the uncertainties in both the unfold algorithm and the error from the absolute calibration of each channel into a one sigma Gaussian error function. One thousand test voltage sets are created using these error functions and processed by the unfold algorithm to produce individual spectra and fluxes. Statistical methods are applied to the resultant set of fluxes to estimate error bars on the measurements.
6. Source geometric considerations for OMEGA Dante measurementsa)
May, M. J.; Patterson, J. R.; Sorce, C.; Widmann, K.; Fournier, K. B.; Perez, F.
2012-10-01
The Dante is a 15 channel filtered diode array which is installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The system yields the spectrally and temporally resolved radiation flux from 50 eV to 10 keV from various targets (i.e., Hohlraum, gas pipes, etc.). The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and an unfold algorithm applied to the recorded voltages from each channel. The unfold algorithm assumes an emitting source that is spatially uniform and has a constant area as a function of photon energy. The emitting x-ray source is usually considered to be the laser entrance hole (LEH) of a given diameter for Hohlraum type targets or the effective wall area of high conversion efficiency K-shell type targets. This assumption can be problematic for several reasons. High intensity regions or "hot spots" in the x-ray are observed where the drive laser beams strike the target. The "hot spots" create non-uniform emission seen by the Dante. Additionally, thinned walled (50 μm) low-Z targets (C22H10N2O5) have an energy dependent source size since the target's walls will be fully opaque for low energies (E < 2-3 keV) yet fully transmissive at higher energies. Determining accurate yields can be challenging for these types of targets. Discussion and some analysis will be presented.
7. KULL Simulations of OMEGA Radiation Flow Experiments
Kallman, J.; MacLaren, S.; Baker, K.; Brunner, T.; Lewis, K.; Zika, M.
2013-10-01
The problem of radiation flow in a right circular cylinder is of interest for the verification and validation of radiation codes since the flow is analytically analogous to diffusive free molecular flow in a similar geometry. Experiments were conducted on the OMEGA laser utilizing a low-density heated-cylindrical-wall target. The targets consisted of a 1.6 mm diameter gold hohlraum containing an on-axis 700 μm diameter SiO2 cylinder inside an 80 μm thick Ta2O5 aerogel tube. The FY13 targets also feature light-pipe'' diagnostics to measure the progression of the radiation front inside the foam. Simulations were run with the KULL multi-physics code, employing a new laser ray-tracing package. Comparisons of synthetic diagnostics derived from code results to x-ray measurements of drive temperature and heat front propagation provide a methodology to constrain simulation models. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
8. Omega-3 and omega-6 content of medicinal foods for depressed patients: implications from the Iranian Traditional Medicine
PubMed Central
2014-01-01
Objectives: Considering the increasing prevalence of depression in modern societies and the positive effects of omega-3 polyunsaturated fatty acids on depression, this study aims to investigate the omega-3 and omega-6 content of various foodstuffs, prescribed or prohibited by Iranian Traditional Medicine (ITM). Materials and Methods: Firstly, reliable sources of Iranian Traditional Medicine were reviewed in order to identify the prescribed and prohibited foodstuffs for depressed patients. Afterwards, according to the online database of United States Department of Agriculture (URL: http://ndb.nal.usda.gov/ndb/search/list), the ratio of linoleic acid to alpha linolenic acid (as representatives of omega-6 and omega-3, respectively) was identified in each foodstuff. Finally, the ratios of omega-6 to omega-3 were compared between seven food groups of vegetables, fruits, dry goods, high protein products, dairies, breads, and spices. Results: Based on the resources of Iranian Traditional Medicine, the following foods are prescribed for depressed patients: basil, coriander, spinach, lettuce, squash, peppermint, dill, chicory, celery, beet, quince, cucumber, watermelon, grape, peach, pomegranate, banana, apple, currant, pistachio, dried fig, almond, egg, chicken, lamb, trout, milk, bread without bran, saffron, oregano, and coriander seeds. On the other hand, cabbage, eggplant, onion, garlic, broad beans, lentils, beef, whole wheat bread, and mustard are prohibited. It should be noted that omega-3 content in some prescribed foods is more than that of the prohibited ones. Conclusion: The present study showed that mint, basil, spinach, lettuce, squash, lamb, saffron, oregano, cucumber, pistachio, milk, and also wild trout can be considered as medicinal foods for depressed patients. PMID:25068136
9. Plasma omega-3 and omega-6 concentrations and risk of cutaneous basal and squamous cell carcinomas in Australian adults.
PubMed
Wallingford, Sarah C; Hughes, Maria Celia; Green, Adèle C; van der Pols, Jolieke C
2013-10-01
Laboratory-based evidence suggests that omega-3 and omega-6 polyunsaturated fatty acids may affect skin photocarcinogenesis, but epidemiologic evidence is inconsistent. In 1,191 White Australian adults, we prospectively investigated associations between baseline plasma concentrations of omega-3 and omega-6 fatty acids and cutaneous basal cell carcinomas (BCC) and squamous cell carcinomas (SCC). Relative risks (RR) and 95% confidence intervals (CI) were estimated on the basis of number of histologically confirmed tumors diagnosed during follow-up (1997-2007). Plasma eicosapentaenoic acid (EPA) concentrations and omega-3/-6 ratio showed significant inverse associations with SCC tumors, comparing higher tertiles with the lowest, in age- and sex-adjusted models (Ptrend = 0.02 and 0.03, respectively) which weakened after adjustment for past sun exposure. Associations between EPA and SCC were stronger among participants with a history of skin cancer at baseline (n = 378; highest vs. lowest tertile: RR = 0.50; 95% CI, 0.28-0.92; Ptrend = 0.01). Total omega-6 was inversely associated with BCC tumors in multivariate models (P = 0.04; highest vs. lowest tertile: RR = 0.71; 95% CI, 0.51-0.99), and more strongly in the subgroup with past skin cancer. Linoleic and linolenic acids were also inversely associated with BCC occurrence in this subgroup. When fatty acids were analyzed as continuous variables, however, there was no evidence of any linear or nonlinear associations. This study provides some support for reduced skin cancer risk with high plasma concentrations of omega-3 and omega-6 fatty acids, but results depended on how fatty acid data were modeled. Further investigation of these associations in larger datasets is needed.
10. Balancing proportions of competing omega-3 and omega-6 highly unsaturated fatty acids (HUFA) in tissue lipids.
PubMed
Bibus, Doug; Lands, Bill
2015-08-01
People eating different balances of omega-3 and omega-6 nutrients develop predictably different proportions of competing highly unsaturated fatty acids (HUFA) in their tissue lipids. While epidemiological studies have associated wide differences in HUFA balance with disease severity, some clinical studies that did not examine wide differences failed to confirm the association. We examined the degree to which the relative amount of arachidonic acid, the major precursor of omega-6 eicosanoids, differs among people who have widely different dietary intakes of omega-3 and omega-6 nutrients. Gas chromatographic analyses of human blood samples describe the balance among n-3 and n-6 HUFA for different individuals. The proportion of the omega-6 arachidonic acid, from which potent eicosanoids are formed, is not constant. It ranges from 30% to 70% of HUFA while the competing n-3 HUFA range from 60% to 10% of HUFA. Significant differences in clinical outcomes between control and intervention groups have been seen when using dietary interventions that shift the balance of n-3 and n-6 nutrients far enough to create a biologically significant difference in the HUFA balance.
11. Theoretical properties of Omega-loops in the convective zone of the Sun. 3: Extended updrafts
NASA Technical Reports Server (NTRS)
Parker, E. N.
1995-01-01
It was pointed out in an earlier paper that the continuing emergence of Omega-loops at localized sites on the surface of the Sun indicates a continuing updraft at those sites. The updraft evidently extends all the way from the base of the convective zone to somewhat near (approximately 10(exp 9)cm) the surface. We pointed out that such updrafts enhance the convective heat transport to the surface, accounting for a major part of the increased solar brightness or irradiance during times of solar activity. The problem is to work out, as much as possible, the dynamical nature of the extended updrafts, initiated as the wakes of successive rising Omega-loops and driven therafter by the convective forces. The question is, does the updraft take on a long-lived columnar form of its own, or does it never devlop beyond a sequence of rising wakes, resembling beads on a string? The dynamics of a columnar updraft is complicated by both the large Reynolds number and the strong stratication of the atmosphere, and by a total lack of direct observational information. Extended slender updrafts are not a spontaneous occurrence in numerical simulations of thermal convection in a stratified atmosphere, although slender concentrated downdrafts commonly occur. This paper examines several aspects of a columnar updrft in a convective atmosphere under various idealized circumstances to investigate to what extent that state can be maintained against the diminishing vorticity and expansion in the updraft. It appears that the successive passage of Omega-loops from the bottom to the top of the convective zone is an essential feature of the continuing existence of the updraft.
12. Lowered omega3 polyunsaturated fatty acids in serum phospholipids and cholesteryl esters of depressed patients.
PubMed
Maes, M; Christophe, A; Delanghe, J; Altamura, C; Neels, H; Meltzer, H Y
1999-03-22
Depression is associated with a lowered degree of esterification of serum cholesterol, an increased C20:4omega6/C20:5omega3 ratio and decreases in omega3 fractions in fatty acids (FAs) or in the red blood cell membrane. The aims of the present study were to examine: (i) serum phospholipid and cholesteryl ester compositions of individual saturated fatty acids (SFAs), monounsaturated FAs (MUFAs) and polyunsaturated FAs (PUFAs) in major depressed patients vs. healthy volunteers; (ii) the relationships between the above FAs and lowered serum zinc (Zn), a marker of the inflammatory response in depression; and (iii) the effects of subchronic treatment with antidepressants on FAs in depression. The composition of the FAs was determined by means of thin layer chromatography in conjunction with gas chromatography. Lipid concentrations were assayed by enzymatic colorimetric methods. The oxidative potential index (OPI) of FAs was computed in 34 major depressed inpatients and 14 normal volunteers. Major depression was associated with: increased MUFA and C22:5omega3 proportions and increased C20:4omega6/C20:5omega3 and C22:5omega6/C22:6omega3 ratios; lower C22:4omega6, C20:5omega3 and C22:5omega3 fractions in phospholipids; lower C18:3omega3, C20:5omega3 and total (sigma)omega3 FAs, and higher C20:4omega6/C20:5omega3 and sigmaomega6/sigmaomega3 ratios in cholesteryl esters; lower serum concentrations of phospholipids and cholesteryl esters; and a decreased OPI. In depression, there were significant and positive correlations between serum Zn and C20:5omega3 and C22:6omega3 fractions in phospholipids; and significant inverse correlations between serum Zn and the sigmaomega6/sigmaomega3, C20:4omega6/C20:5omega3, and C22:5omega6/C22:6omega3 ratios in phospholipids. There was no significant effect of antidepressive treatment on any of the FAs. The results show that, in major depression, there is a deficiency of omega3 PUFAs and a compensatory increase in MUFAs and C22:5omega6 in
13. Unbalanced omega-6/omega-3 ratio in red meat products in China
PubMed Central
Yu, Ming; Gao, Qianqian; Wang, Yan; Zhang, Wei; Li, Lin; Wang, Ying; Dai, Yifan
2013-01-01
Dietary meats play a crucial role in human health. The objective of this survey was to determine the fatty acid content and omega-6/omega-3 polyunsaturated fatty acids (n-6/n-3 PUFA) ratio of fresh red meat (beef and pork) from four cities (Shanghai, Nanjing, Yinchuan and Hohhot) in China. The results showed that the n-6/n-3 PUFA ratio from all the samples ranged from 6 to 23. The total n-6 PUFA concentrations ranged from 290.54 mg/100 g in beef from Nanjing to 1601.48 mg/100 g in pork from Hohhot, whereas the total concentrations of n-3 PUFA ranged from 46.34 mg/100 g in beef from Nanjing to 96.03 mg/100 g in pork from Nanjing. The results indicated that the n-6/n-3 ratio in the red meat from all four regions is unbalanced and is much higher than that (< 5:1) recommended by the WHO/FAO. The total amount of n-3 PUFA was far lower than the required daily dose. Therefore, potential solutions to increase the n-3 PUFA content in meat products or to provide alternative source of n-3 PUFA should be explored. PMID:24086169
14. Separation of dietary omega-3 and omega-6 fatty acids in food by capillary electrophoresis.
PubMed
Soliman, Laiel C; Donkor, Kingsley K; Church, John S; Cinel, Bruno; Prema, Dipesh; Dugan, Michael E R
2013-10-01
A lower dietary omega-6/omega-3 (n-6/n-3) fatty acid ratio (<4) has been shown to be beneficial in preventing a number of chronic illnesses. Interest exists in developing more rapid and sensitive analytical methods for profiling fatty acid levels in foods. An aqueous CE method was developed for the simultaneous determination of 15 n-3 and n-6 relevant fatty acids. The effect of pH and concentration of buffer, type and concentration of organic modifier, and additive on the separation was investigated in order to determine the best conditions for the analysis. Baseline separations of the 15 fatty acids were achieved using 40 mM borate buffer at pH 9.50 containing 50 mM SDS, 10 mM β-cyclodextrin, and 10% acetonitrile. The developed CE method has LODs of <5 mg/L and good linearity (R(2) > 0.980) for all fatty acids studied. The proposed method was successfully applied to the determination of n-3 and n-6 fatty acids in flax seed, Udo® oils and a selection of grass-fed and grain-fed beef muscle samples.
15. Helping women to good health: breast cancer, omega-3/omega-6 lipids, and related lifestyle factors.
PubMed
de Lorgeril, Michel; Salen, Patricia
2014-03-27
In addition to genetic predisposition and sex hormone exposure, physical activity and a healthy diet play important roles in breast cancer (BC). Increased intake of omega-3 fatty acids (n-3) associated with decreased omega-6 (n-6), resulting in a higher n-3/n-6 ratio compared with the western diet, are inversely associated with BC risk, as shown by Yang et al. in their meta-analysis in BMC Cancer. High consumption of polyphenols and organic foods increase the n-3/n-6 ratio, and in turn may decrease BC risk. Intake of high fiber foods and foods with low glycemic index decreases insulin resistance and diabetes risk, and in turn may decrease BC risk. The modernized Mediterranean diet is an effective strategy for combining these recommendations, and this dietary pattern reduces overall cancer risk and specifically BC risk. High-risk women should also eliminate environmental endocrine disruptors, including those from foods. Drugs that decrease the n-3/n-6 ratio or that are suspected of increasing BC or diabetes risk should be used with great caution by high-risk women and women wishing to decrease their BC risk.Please see related article: http://www.biomedcentral.com/1471-2407/14/105/abstract.
16. Accuracy of free energies of hydration using CM1 and CM3 atomic charges.
PubMed
Udier-Blagović, Marina; Morales De Tirado, Patricia; Pearlman, Shoshannah A; Jorgensen, William L
2004-08-01
Absolute free energies of hydration (DeltaGhyd) have been computed for 25 diverse organic molecules using partial atomic charges derived from AM1 and PM3 wave functions via the CM1 and CM3 procedures of Cramer, Truhlar, and coworkers. Comparisons are made with results using charges fit to the electrostatic potential surface (EPS) from ab initio 6-31G* wave functions and from the OPLS-AA force field. OPLS Lennard-Jones parameters for the organic molecules were used together with the TIP4P water model in Monte Carlo simulations with free energy perturbation theory. Absolute free energies of hydration were computed for OPLS united-atom and all-atom methane by annihilating the solutes in water and in the gas phase, and absolute DeltaGhyd values for all other molecules were computed via transformation to one of these references. Optimal charge scaling factors were determined by minimizing the unsigned average error between experimental and calculated hydration free energies. The PM3-based charge models do not lead to lower average errors than obtained with the EPS charges for the subset of 13 molecules in the original study. However, improvement is obtained by scaling the CM1A partial charges by 1.14 and the CM3A charges by 1.15, which leads to average errors of 1.0 and 1.1 kcal/mol for the full set of 25 molecules. The scaled CM1A charges also yield the best results for the hydration of amides including the E/Z free-energy difference for N-methylacetamide in water.
17. Omega-3 Fatty acids and airway hyperresponsiveness in asthma.
PubMed
Mickleborough, Timothy D; Ionescu, Alina A; Rundell, Kenneth W
2004-12-01
Despite the progress that has been made in the treatment of asthma, the prevalence and burden of this disease has continued to increase. Exercise is a powerful trigger of asthma symptoms and reversible airflow obstruction and may result in the avoidance of physical activity by patients with asthma, resulting in detrimental consequences to their health. Approximately 90% of patients with asthma are hyperresponsive to exercise and experience exercise-induced bronchoconstriction (EIB). While pharmacologic treatment of asthma is usually highly effective, medications often have significant side-effects or exhibit tachyphylaxis. Alternative therapies for treatment (complementary medicine) that reduce the dose requirements of pharmacologic interventions would be beneficial, and could potentially reduce the public health burden of this disease. There is accumulating evidence that dietary modification has potential to influence the severity of asthma and reduce the prevalence and incidence of this condition. A possible contributing factor to the increased incidence of asthma in Western societies may be the consumption of a proinflammatory diet. In the typical Western diet, 20- to 25-fold more omega- 6 polyunsaturated fatty acids (PUFA) than omega-3 PUFA are consumed, which causes the release of proinflammatory arachidonic acid metabolites (leukotrienes and prostanoids). This review analyzes the existing literature on omega-3 PUFA supplementation as a potential modifier of airway hyperresponsiveness in asthma and includes studies concerning the efficacy of omega-3 PUFA supplementation in EIB. While clinical data evaluating the effect of omega-3 PUFA supplementation in asthma has been equivocal, it has recently been shown that pharmaceutical-grade fish oil (omega-3 PUFA) supplementation reduces airway hyperresponsiveness after exercise, medication use, and proinflammatory mediator generation in nonatopic elite athletes with EIB. These findings are provocative and suggest that
18. Hubble Space Telescope Image of Omega Nebula
NASA Technical Reports Server (NTRS)
2002-01-01
This sturning image, taken by the newly installed Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST), is an image of the center of the Omega Nebula. It is a hotbed of newly born stars wrapped in colorful blankets of glowing gas and cradled in an enormous cold, dark hydrogen cloud. The region of nebula shown in this photograph is about 3,500 times wider than our solar system. The nebula, also called M17 and the Swan Nebula, resides 5,500 light-years away in the constellation Sagittarius. The Swan Nebula is illuminated by ultraviolet radiation from young, massive stars, located just beyond the upper-right corner of the image. The powerful radiation from these stars evaporates and erodes the dense cloud of cold gas within which the stars formed. The blistered walls of the hollow cloud shine primarily in the blue, green, and red light emitted by excited atoms of hydrogen, nitrogen, oxygen, and sulfur. Particularly striking is the rose-like feature, seen to the right of center, which glows in the red light emitted by hydrogen and sulfur. As the infant stars evaporate the surrounding cloud, they expose dense pockets of gas that may contain developing stars. One isolated pocket is seen at the center of the brightest region of the nebula. Other dense pockets of gas have formed the remarkable feature jutting inward from the left edge of the image. The color image is constructed from four separate images taken in these filters: blue, near infrared, hydrogen alpha, and doubly ionized oxygen. Credit: NASA, H. Ford (JHU), G. Illingworth (USCS/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.
19. New λ6 cm and λ11 cm observations of the supernova remnant CTA 1
Sun, X. H.; Reich, W.; Wang, C.; Han, J. L.; Reich, P.
2011-11-01
Aims: We attempt to study spatial variations in the spectrum and rotation measures (RMs) of the large-diameter, high-latitude supernova remnant (SNR) CTA 1. Methods: We conducted new λ6 cm and λ11 cm observations of CTA 1 using the Urumqi 25-m and Effelsberg 100-m telescopes. Data at other wavelengths were included to investigate the spectrum and polarisation properties. Results: We obtained new total intensity and polarisation maps at λ6 cm and λ11 cm with angular resolutions of 9'.5and 4'.4, respectively. We derived a spectral index of α = -0.63 ± 0.05 (Sν ∝ να) based on the integrated flux densities at 408 MHz, 1420 MHz, 2639 MHz, and 4800 MHz. The spectral index map calculated from data at the four frequencies shows a clear steepening of the spectrum from the strong shell emission towards the north-western breakout region with weak diffuse emission. The decrease of the spectral index is up to about Δα = 0.3. The RM map derived from polarisation data at λ6 cm and λ11 cm shows a sharp transition between positive RMs in the north-eastern and negative RMs in the south-western part of the SNR. We note a corresponding RM pattern of extragalactic sources and propose the existence of a large-diameter Faraday screen in front of CTA 1, which covers the north-eastern part of the SNR. The RM of the Faraday screen is estimated to be about +45 rad m-2. A RM structure function of CTA 1 indicates a very regular magnetic field within the Faraday screen, which is stronger than about 2.7 μG for a distance of 500 pc. Conclusions: CTA 1 is a large-diameter shell-type SNR located out of the Galactic plane, which makes it an ideal object to study its properties without suffering confusion. The previous detection of the rare breakout phenomenon in CTA 1 is confirmed. We identify a Faraday screen partly covering CTA 1 with a regular magnetic field in the opposite direction to the interstellar magnetic field. The detection of Faraday screens in the Galactic plane is
20. Absorption of intact beta-casomorphins (beta-CM) in rabbit ileum in vitro.
PubMed
Mahè, S; Tomè, D; Dumontier, A M; Desjeux, J F
1989-01-01
The functional significance of the presence of opioid peptides in enzymatic digestion of bovine milk beta-casein remains unclear. Opiates modify intestinal electrolyte transport by acting on receptors located on the serosal side of the intestine. The aim of the present study is to determine under which conditions beta-casomorphins could act from the luminal side of the intestine. The effect of natural morphiceptin (beta-CM4-NH2) and the non metabolized analogue beta-[DAla2,4, Try5]-CM5-NH2 were studied on isolated rabbit ileum mounted in Ussing chambers. Both peptides caused a naloxone-reversible reduction in short-circuit current (lsc) and stimulated Na and Cl absorption after addition to the serosal side of the tissue. After mucosal addition, only the analogue (10(-3) M) crossed the epithelium intact (Jm-s = 3.5 +/- 1.2 nmol.h-1.cm-2) and reduced lsc. Morphiceptin, under the same conditions, was degraded by the intestinal mucosa without opiate action on electrolyte transport. Pretreatment of the ileum by 10(-3)M diisopropylfluorophosphate that inhibited brush-border dipeptidylpeptidase IV, prevented mucosal degradation of morphiceptin. Under these conditions, the peptide (10(-3)M) crossed the epithelium intact (Jm-s = 1.8 +/- 0.16 nmol.h-1.cm-2) and stimulated electrolyte absorption by means of an opioid mechanism. These results show that both natural morphiceptin and the protected analogue have an opiate activity on intestinal electrolyte transport. Their action from the lumen depends on their transfer intact to the serosal side of the intestine where opiate receptors are located. The limiting step in this transfer is at the brush-border membrane where dipeptidylpeptidase IV in particular seems to play a major role.
1. PROCESS OF PRODUCING Cm$sup 244$ AND Cm$sup 24$$sup 5$
DOEpatents
Manning, W.M.; Studier, M.H.; Diamond, H.; Fields, P.R.
1958-11-01
A process is presented for producing Cm and Cm/sup 245/. The first step of the process consists in subjecting Pu/sup 2339/ to a high neutron flux and subsequently dissolving the irradiated material in HCl. The plutonium is then oxidized to at least the tetravalent state and the solution is contacted with an anion exchange resin, causing the plutonium values to be absorbed while the fission products and transplutonium elements remain in the effluent solution. The effluent solution is then contacted with a cation exchange resin causing the transplutonium, values to be absorbed while the fission products remain in solution. The cation exchange resin is then contacted with an aqueous citrate solution and tbe transplutonium elements are thereby differentially eluted in order of decreasing atomic weight, allowing collection of the desired fractions.
2. Demonstration of the highest deuterium-tritium areal density using multiple-picket cryogenic designs on OMEGA.
PubMed
Goncharov, V N; Sangster, T C; Boehly, T R; Hu, S X; Igumenshchev, I V; Marshall, F J; McCrory, R L; Meyerhofer, D D; Radha, P B; Seka, W; Skupsky, S; Stoeckl, C; Casey, D T; Frenje, J A; Petrasso, R D
2010-04-23
The performance of triple-picket deuterium-tritium cryogenic target designs on the OMEGA Laser System [T. R. Boehly, Opt. Commun. 133, 495 (1997)] is reported. These designs facilitate control of shock heating in low-adiabat inertial confinement fusion targets. Areal densities up to 300 mg/cm2 (the highest ever measured in cryogenic deuterium-tritium implosions) are inferred in the experiments with an implosion velocity approximately 3x10(7) cm/s driven at peak laser intensities of 8x10(14) W/cm2. Extension of these designs to ignition on the National Ignition Facility [J. A. Paisner, Laser Focus World 30, 75 (1994)] is presented.
3. Omega-3 fatty acids in inflammation and autoimmune diseases.
PubMed
Simopoulos, Artemis P
2002-12-01
Among the fatty acids, it is the omega-3 polyunsaturated fatty acids (PUFA) which possess the most potent immunomodulatory activities, and among the omega-3 PUFA, those from fish oil-eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)--are more biologically potent than alpha-linolenic acid (ALA). Some of the effects of omega-3 PUFA are brought about by modulation of the amount and types of eicosanoids made, and other effects are elicited by eicosanoid-independent mechanisms, including actions upon intracellular signaling pathways, transcription factor activity and gene expression. Animal experiments and clinical intervention studies indicate that omega-3 fatty acids have anti-inflammatory properties and, therefore, might be useful in the management of inflammatory and autoimmune diseases. Coronary heart disease, major depression, aging and cancer are characterized by an increased level of interleukin 1 (IL-1), a proinflammatory cytokine. Similarly, arthritis, Crohn's disease, ulcerative colitis and lupus erythematosis are autoimmune diseases characterized by a high level of IL-1 and the proinflammatory leukotriene LTB(4) produced by omega-6 fatty acids. There have been a number of clinical trials assessing the benefits of dietary supplementation with fish oils in several inflammatory and autoimmune diseases in humans, including rheumatoid arthritis, Crohn's disease, ulcerative colitis, psoriasis, lupus erythematosus, multiple sclerosis and migraine headaches. Many of the placebo-controlled trials of fish oil in chronic inflammatory diseases reveal significant benefit, including decreased disease activity and a lowered use of anti-inflammatory drugs.
4. Cardiac mortality is associated with low levels of omega-3 and omega-6 fatty acids in the heart of cadavers with a history of coronary heart disease.
PubMed
Chattipakorn, Nipon; Settakorn, Jongkolnee; Petsophonsakul, Petnoi; Suwannahoi, Padiphat; Mahakranukrauh, Pasuk; Srichairatanakool, Somdet; Chattipakorn, Siriporn C
2009-10-01
The benefits of omega-3 (ie, eicosapentaenoic acid and docosahexaenoic acid [DHA]) and omega-6 (ie, linoleic acid and arachidonic acid [AA]) fatty acids on reducing cardiac mortality are still debated. In this study, we tested the hypothesis that high levels of omega-3 and omega-6 fatty acids in heart tissues are associated with low cardiac mortality in Thai cadavers. One hundred fresh cadavers were examined in this study. The cause of death, history of coronary heart disease (CHD), and fish consumption habits were obtained from death certificates, cadaver medical record profiles, and a questionnaire to a person who lived with the subject before death. In each cadaver, biopsies of cardiac tissues were taken from the interventricular septum for measurement of fatty acid. Of the 100 cadavers (average age, 69 +/- 13 years), 60 were men. The frequency of fish consumption was directly associated with omega-3 and omega-6 fatty acids in heart tissues (P < .01). History of CHD and cause of death (cardiac vs noncardiac) were not significantly associated with levels of omega-3 or omega-6 fatty acids. However, in cadavers with a history of CHD, high levels of omega-3 and omega-6, particularly DHA and AA, were associated with low cardiac mortality (P < .05). Fish consumption is associated with levels of omega-3 and omega-6 fatty acids in heart tissues. Although omega-3 and omega-6 fatty acids are not associated with cardiac mortality in the overall studied population, their low levels (especially DHA and AA) in heart tissues are associated with high cardiac mortality in cadavers with a history of CHD.
5. Promotion of prostatic metastatic migration towards human bone marrow stoma by Omega 6 and its inhibition by Omega 3 PUFAs
PubMed Central
Brown, M D; Hart, C A; Gazi, E; Bagley, S; Clarke, N W
2006-01-01
Epidemiological studies have shown not only a relationship between the intake of dietary lipids and an increased risk of developing metastatic prostate cancer, but also the type of lipid intake that influences the risk of metastatic prostate cancer. The Omega-6 poly-unsaturated fatty acid, Arachidonic acid, has been shown to enhance the proliferation of malignant prostate epithelial cells and increase the risk of advanced prostate cancer. However, its role in potentiating the migration of cancer cells is unknown. Here we show that arachidonic acid at concentrations ⩽5 μM is a potent stimulator of malignant epithelial cellular invasion, which is able to restore invasion toward hydrocortisone-deprived adipocyte-free human bone marrow stroma completely. This observed invasion is mediated by the arachidonic acid metabolite prostaglandin E2 and is inhibited by the Omega-3 poly-unsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid at a ratio of 1 : 2 Omega-3 : Omega-6, and by the COX-2 inhibitor NS-398. These results identify a mechanism by which arachidonic acid may potentiate the risk of metastatic migration and secondary implantation in vivo, a risk which can be reduced with the uptake of Omega-3 poly-unsaturated fatty acids. PMID:16523199
6. Evidence for the decay X(3872) -> J/\\psi\\omega
SciTech Connect
del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison
2011-08-11
We present a study of the decays B{sup 0,+} --> J/{psi}{pi}{sup +}{pi}{sup -}{pi}{sup 0}K{sup 0,+}, using 467x10{sup 6} B{anti B} pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) --> J/{psi}{omega}, with product branching fractions B(B{sup +} --> X(3872)K{sup +}) x B(X(3872) --> J/{psi}{omega}) = [0.6 {+-} 0.2(stat) {+-} 0.1(syst)] x 10{sup -5}, and B(B{sup 0} --> X(3872)K{sup 0}) x B(X(3872) --> J/{psi}{omega}) = [0.6 {+-} 0.3(stat) {+-} 0.1(syst)] x 10{sup -5}. A detailed study of the {pi}{sup +}{pi}{sup -}{pi}{sup 0} mass distribution from X(3872) decay favors a negative-parity assignment.
7. Rapid lipid enrichment in omega3 fatty acids: liver data.
PubMed
Carpentier, Yvon A; Peltier, Sebastien; Portois, Laurence; Sener, Abdullah; Malaisse, Willy J
2008-03-01
The bolus intravenous injection of a novel medium-chain triglyceride:fish oil emulsion to normal subjects was recently reported to enrich within 60 min the phospholipid content of leucocytes and platelets in long-chain polyunsaturated omega3 fatty acids. The present study, conducted in second generation omega3-depleted rats, aims at investigating whether such a procedure may also increase within 60 min the phospholipid content of omega3 fatty acids in cells located outwards of the bloodstream, in this case liver cells, and whether this coincides with correction of the perturbation in the liver triglyceride fatty acid content and profile otherwise prevailing in these rats. The results indicate that such is indeed the case and further suggest a cause-to-effect relationship between the two events.
8. The Fifth Omega Laser Facility Users Group Workshop
SciTech Connect
Petrasso, R. D.
2015-10-01
A capacity gathering of over 100 researchers from 25 universities and laboratories met at the Laboratory for Laser Energetics (LLE) for the Fifth Omega Laser Facility Users Group (OLUG) workshop. The purpose of the 2.5-day workshop was to facilitate communications and exchanges among individual Omega users and between users and the LLE management; to present ongoing and proposed research; to encourage research opportunities and collaborations that could be undertaken at the Omega Laser Facility and in a complementary fashion at other facilities [such as the National Ignition Facility (NIF) or the Laboratoire pour l’Utilisation des Lasers Intenses (LULI)]; to provide an opportunity for students, postdoctoral fellows, and young researchers to present their research in an informal setting; and to provide feedback to LLE management from the users about ways to improve the facility and future experimental campaigns.
9. Constraining omega and bias from the Stromlo-APM survey
SciTech Connect
Loveday, J.
1995-05-01
Galaxy redshift surveys provide a distorted picture of the universe due to the non-Hubble component of galaxy motions. By measuring such distortions in the linear regime one can constrain the quantity {beta} = {Omega}{sup 0.6} where {Omega} is the cosmological density parameter and b is the (linear) bias factor for optically-selected galaxies. In this paper we estimate {beta} from the Stromlo-APM redshift survey by comparing the amplitude of the direction-averaged redshift space correlation function to the real space correlation function. We find a 95% confidence upper limit of {beta} = 0.75, with a best estimate of {beta} {approx} 0.48. A bias parameter b {approx} 2 is thus required if {Omega} {equivalent_to} 1. However, higher-order correlations measured from the APM galaxy survey indicate a low value for the bias parameter b {approx} 1, requiring that Q {approx_lt} 0.6.
10. Deeply virtual and exclusive production of the omega meson
SciTech Connect
M. Garcon; L. Morand; D. Dore; J.-M. Laget; S. Morrow; F. Sabatie
2005-04-01
Exclusive {omega} electroproduction off the proton was measured at the highest possible four-momentum transfer with the (close to) 6 GeV beam now available at CEBAF. Cross sections are presented, together with an analysis of the {omega} spin density matrix elements. Indications are that {pi}{sup 0} exchange in the t-channel (or rather the exchange of the corresponding saturating Regge trajectory) seems to dominate the process {gamma}*p {yields} {omega}p, even for photon virtuality Q{sup 2} as large as 5 GeV{sup 2}. Contributions of the handbag type, related to Generalized Parton Distributions in the nucleon, are therefore difficult to extract from this particular process.
11. The Sixth Omega Laser Facility Users Group Workshop
SciTech Connect
Petrasso, R. D.
2014-10-01
A capacity gathering of over 100 researchers from 25 universities and laboratories met at the Laboratory for Laser Energetics (LLE) for the Sixth Omega Laser Facility Users Group (OLUG) workshop. The purpose of the 2.5-day workshop was to facilitate communications and exchanges among individual OMEGA users, and between users and the LLE management; to present ongoing and proposed research; to encourage research opportunities and collaborations that could be undertaken at the Omega Laser Facility and in a complementary fashion at other facilities [such as the National Ignition Facility (NIF) or the Laboratoire pour l’Utilisation des Lasers Intenses (LULI)]; to provide an opportunity for students, postdoctoral fellows, and young researchers to present their research in an informal setting; and to provide feedback from the users to LLE management about ways to improve and keep the facility and future experimental campaigns at the cutting edge.
12. Search for Lepton Flavor Violating Decays Tau+- to L+- Omega
SciTech Connect
Schenk, S.; /Heidelberg U.
2011-11-30
This paper reports on a search for lepton flavor violating decays of a {tau} lepton to a lighter-mass charged lepton and an {omega} vector meson. The data sample corresponds to an integrated luminosity of 384 fb{sup -1} recorded by the BaBar experiment at the SLAC PEP-II asymmetric-energy B Factory. No evidence for a signal is found and the upper limits on the branching ratios are determined to be B({tau}{sup {+-}} {yields} e{sup {+-}}{omega}) < 1.1 x 10{sup -7} and B({tau}{sup {+-}} {yields} {mu}{sup {+-}}{omega}) < 1.0 x 10{sup -7} at 90% confidence level.
13. 46 CFR 53.10-3 - Inspection and tests (modifies HG-500 through HG-540).
Code of Federal Regulations, 2014 CFR
2014-10-01
... ENGINEERING HEATING BOILERS Tests, Inspection, Stamping, and Reporting (Article 5) § 53.10-3 Inspection and... commission issued by the National Board of Boiler and Pressure Vessel Inspectors. After installation, heating... heating boilers must have the operation of their pressure relieving devices checked after the...
14. 46 CFR 53.10-3 - Inspection and tests (modifies HG-500 through HG-540).
Code of Federal Regulations, 2010 CFR
2010-10-01
... ENGINEERING HEATING BOILERS Tests, Inspection, Stamping, and Reporting (Article 5) § 53.10-3 Inspection and... commission issued by the National Board of Boiler and Pressure Vessel Inspectors. After installation, heating... heating boilers must have the operation of their pressure relieving devices checked after the...
15. 46 CFR 53.10-3 - Inspection and tests (modifies HG-500 through HG-540).
Code of Federal Regulations, 2012 CFR
2012-10-01
... ENGINEERING HEATING BOILERS Tests, Inspection, Stamping, and Reporting (Article 5) § 53.10-3 Inspection and... commission issued by the National Board of Boiler and Pressure Vessel Inspectors. After installation, heating... heating boilers must have the operation of their pressure relieving devices checked after the...
16. 46 CFR 53.10-3 - Inspection and tests (modifies HG-500 through HG-540).
Code of Federal Regulations, 2013 CFR
2013-10-01
... ENGINEERING HEATING BOILERS Tests, Inspection, Stamping, and Reporting (Article 5) § 53.10-3 Inspection and... commission issued by the National Board of Boiler and Pressure Vessel Inspectors. After installation, heating... heating boilers must have the operation of their pressure relieving devices checked after the...
17. 46 CFR 53.10-3 - Inspection and tests (modifies HG-500 through HG-540).
Code of Federal Regulations, 2011 CFR
2011-10-01
... ENGINEERING HEATING BOILERS Tests, Inspection, Stamping, and Reporting (Article 5) § 53.10-3 Inspection and... commission issued by the National Board of Boiler and Pressure Vessel Inspectors. After installation, heating... heating boilers must have the operation of their pressure relieving devices checked after the...
18. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...
Code of Federal Regulations, 2014 CFR
2014-07-01
....-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic). 721.10214 Section 721.10214... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...
19. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...
Code of Federal Regulations, 2012 CFR
2012-07-01
....-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic). 721.10214 Section 721.10214... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...
20. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...
Code of Federal Regulations, 2013 CFR
2013-07-01
....-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic). 721.10214 Section 721.10214... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...
1. 40 CFR 721.10286 - Formaldehyde, polymer with .alpha.- (2-aminomethylethyl)- .omega. - (2 - aminomethylethoxy)poly...
Code of Federal Regulations, 2013 CFR
2013-07-01
...-aminomethylethyl)- .omega. - (2 - aminomethylethoxy)poly and 4 - (1,1 -dimethylethyl) phenol. 721.10286 Section 721... Formaldehyde, polymer with .alpha.- (2-aminomethylethyl)- .omega. - (2 - aminomethylethoxy)poly and 4 - (1,1... substance identified as formaldehyde, polymer with...
2. Towards the Industrial Production of Omega-3 Long Chain Polyunsaturated Fatty Acids from a Genetically Modified Diatom Phaeodactylum tricornutum
PubMed Central
Hamilton, Mary L.; Warwick, Joanna; Terry, Anya; Allen, Michael J.; Napier, Johnathan A.; Sayanova, Olga
2015-01-01
and F/2 nutrients was 24.8% EPA and 10.3% DHA. Transgenic strain grown in RP produced the highest levels of EPA (12.8%) incorporated in neutral lipids. However, the highest partitioning of DHA in neutral lipids was observed in cultures grown in PBR (7.1%). Our results clearly demonstrate the potential for the development of the transgenic Pt_Elo5 as a platform for the commercial production of EPA and DHA. PMID:26658738
3. Towards the Industrial Production of Omega-3 Long Chain Polyunsaturated Fatty Acids from a Genetically Modified Diatom Phaeodactylum tricornutum.
PubMed
Hamilton, Mary L; Warwick, Joanna; Terry, Anya; Allen, Michael J; Napier, Johnathan A; Sayanova, Olga
2015-01-01
and F/2 nutrients was 24.8% EPA and 10.3% DHA. Transgenic strain grown in RP produced the highest levels of EPA (12.8%) incorporated in neutral lipids. However, the highest partitioning of DHA in neutral lipids was observed in cultures grown in PBR (7.1%). Our results clearly demonstrate the potential for the development of the transgenic Pt_Elo5 as a platform for the commercial production of EPA and DHA.
4. A DEEP CHANDRA X-RAY LIMIT ON THE PUTATIVE IMBH IN OMEGA CENTAURI
SciTech Connect
Haggard, Daryl; Cool, Adrienne M.; Heinke, Craig O.; Van der Marel, Roeland; Anderson, Jay; Cohn, Haldan N.; Lugger, Phyllis M. E-mail: cool@sfsu.edu
2013-08-20
We report a sensitive X-ray search for the proposed intermediate-mass black hole (IMBH) in the massive Galactic cluster, {omega} Centauri (NGC 5139). Combining Chandra X-ray Observatory data from Cycles 1 and 13, we obtain a deep ({approx}291 ks) exposure of the central regions of the cluster. We find no evidence for an X-ray point source near any of the cluster's proposed dynamical centers, and place an upper limit on the X-ray flux from a central source of f{sub X}(0.5-7.0 keV) {<=}5.0 Multiplication-Sign 10{sup -16} erg cm{sup -2} s{sup -1}, after correcting for absorption. This corresponds to an unabsorbed X-ray luminosity of L{sub X}(0.5-7.0 keV) {<=}1.6 Multiplication-Sign 10{sup 30} erg s{sup -1}, for a cluster distance of 5.2 kpc, Galactic column density N{sub H} = 1.2 Multiplication-Sign 10{sup 21} cm{sup -2}, and power-law spectrum with {Gamma} = 2.3. If a {approx}10{sup 4} M{sub sun} IMBH resides in the cluster's core, as suggested by some stellar dynamical studies, its Eddington luminosity would be L{sub Edd} {approx}10{sup 42} erg s{sup -1}. The new X-ray limit would then establish an Eddington ratio of L{sub X}/L{sub Edd} {approx}< 10{sup -12}, a factor of {approx}10 lower than even the quiescent state of our Galaxy's notoriously inefficient supermassive black hole Sgr A*, and imply accretion efficiencies as low as {eta} {approx}< 10{sup -6}-10{sup -8}. This study leaves open three possibilities: either {omega} Cen does not harbor an IMBH or, if an IMBH does exist, it must experience very little or very inefficient accretion.
5. Low-cost mechanical filters for OMEGA receivers
NASA Technical Reports Server (NTRS)
Burhans, R. W.
1976-01-01
A pair of prototype low frequency mechanical filters were obtained for use as the RF front-end components of an OMEGA-VLF navigation receiver. The filter units are of interest because of very narrow bandwidths and high skirt selectivity to minimize noise and off-channel carriers in the reception of OMEGA signals. In addition, the filters have a characteristic low impedance of 75 to 5,000 ohms which results in less critical PC board circuitry compared to some previous resonators with termination resistances of 25,000 ohms to 5 megohms.
6. VLA Images of Venus at 1.3 CM and 2 CM Wavelengths
Suleiman, S. H.; Kolodner, M. A.; Butler, B. J.; Steffes, P. G.
1996-09-01
On April 5, 1996, we performed an observation of Venus using the Very Large Array (VLA) at 15 GHz (2 cm) and 22 GHz (1.3 cm) simultaneously. High resolution continuum images for Venus were obtained at both frequencies. These images show significant polar darkening at latitudes above 60(deg) which is consistent with the results obtained by the Pioneer Venus Orbiter Infrared Radiometer (OIR) experiment (Taylor et al., J. Geophys. Res. 85, 7963-8006, 1980). These images are currently being used to detect potential spatial (longitudinal and latitudinal) variations in the abundances of gaseous sulfur dioxide (SO_2) and gaseous sulfuric acid (H_2SO_4) across the disk of Venus. Our new radiative transfer model (RTM) has shown that the emission spectrum is especially sensitive to the abundances of these constituents at these wavelengths. The detection of these constituents is being accomplished by matching the computed emission from our RTM to the measured emission of Venus by the VLA. Our RTM incorporates the newly developed Ben Reuven formalism which provides a more accurate characterization of the microwave absorption of gaseous SO_2 (Suleiman et al., J. Geophys. Res. 101, 4623-4635, 1996). A description of the observation, visibility data, and images are presented. This work was supported by the NASA Planetary Atmospheres Program under grant NAGW-533.
7. A Study of Production and Decay of Omega_c^0 Baryons in BABAR
SciTech Connect
Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Pappagallo, M.; Pompili, A.; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; Eigen, G.; Ofte, I.; Stugu, B. /University of Bergen, Institute of Physics, N-5007 Bergen, Norway /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /Pisa U. /INFN, Pisa /Prairie View A-M /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Stony Brook /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Vanderbilt U. /Victoria U. /Wisconsin U., Madison /Yale U.
2005-09-28
Production and decay of {Omega}{sub c}{sup 0} baryons is studied with {approx} 230 fb{sup -1} of data recorded with the BABAR detector at the PEP-II e{sup +}e{sup -} asymmetric-energy storage ring at SLAC. The {Omega}{sub c}{sup 0} is reconstructed through its decays into {Omega}{sup -}{pi}{sup +}, {Omega}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}, {Xi}{sup -}K{sup -}{pi}{sup +}{pi}{sup +} final states. The invariant mass spectra are presented and the signal yields are extracted. Ratios of branching fractions are measured relative to the {Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +} mode {Beta}({Omega}{sub c}{sup 0} {yields} {Xi}{sup -} K{sup -}{pi}{sup +}{pi}{sup +})/{Beta}({Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +}) = 0.31 {+-} 0.15(stat.) {+-} 0.04(syst.), {Beta}({Omega}{sub c}{sup 0} {yields} {Omega}{sup -} {pi}{sup +}{pi}{sup -}{pi}{sup +})/{Beta}({Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +}) < 0.30 (90%CL). The momentum spectrum (not corrected for efficiency) of {Omega}{sub c}{sup 0} baryons is extracted from decays into {Omega}{sup -}{pi}{sup +}, establishing the first observation of {Omega}{sub c}{sup 0} production from B decays.
8. Enhanced Performance of Large 3(omega) Optics Using UV and IR Lasers
SciTech Connect
Prasad, R R; Bruere, J; Peterson, J; Halpin, J; Borden, M; Hackel, R P
2003-11-01
We have developed techniques using small-beam raster scanning to laser-condition fused silica optics to increase their damage threshold. Further, we showed that CO{sub 2} lasers could be used to mitigate and stabilize damage sites while still on the order of a few tens of microns in size, thereby greatly increasing the lifetime of an optic. We recently activated the Phoenix pre-production facility to condition and mitigate optics as large as 43 cm x 43 cm. Several full-scale optics have been processed in Phoenix. The optics were first photographed using a damage mapping system to identify scratches, digs, or other potential sites for initiation of laser damage. We then condition the optic, raster scanning with the excimer laser. The first scan is performed at a low fluence. A damage map is then acquired and any new damage sites or any sites that have grown in size are mitigated using the CO{sub 2} laser. The process is repeated at successively higher fluences until a factor of 1.7 above the nominal operating fluence is reached. After conditioning, optics were tested in a large beam 3{omega} laser and showed no damage at fluences of 8 J/cm{sup 2} average.
9. Spherical Rayleigh-Taylor Growth of Three-Dimensional Broadband Perturbations on OMEGA
SciTech Connect
Smalyuk, V.A.; Hu, S.X.; Hager, J.D.; Delettrez, J.A.; Meyerhofer, D.D.; Sangster, T.C.; Shvarts, D.
2009-11-10
Spherical Rayleigh–Taylor (RT) growth experiments of three-dimensional (3D) broadband nonuniformities were conducted in the acceleration phase of spherical implosions on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The targets consisted of 20- and 24-um-thick plastic spherical shells having diagnostic openings for backlighter x rays to image shell modulations. Experiments were conducted with square laser pulses at a low drive intensity of ~2 x 10^14 W/cm^2, high drive intensity of ~1 x 10^15 W/cm^2, and a shaped pulse consisting of a low-intensity foot and high-intensity drive part (peak intensity of ~1 x 10^15 W/cm^2). In low-intensity experiments, large RT growth was measured, resulting in shells being broken up by 3D modulations at the end of the drive. In the high-intensity experiments, no RT growth of the 3D modulations was detected. In the shaped-pulse experiments, perturbations grew during the low-intensity part of the drive and were stabilized later during the high-intensity part of the drive. The measured RT growth stabilization with the high-intensity drive was similar to previous observations in planar geometry [V. A. Smalyuk et al., Phys. Rev. Lett. 101, 025002 (2008)].
10. Antioxidant activity of sesamol and omega-oryzanol towards fish oil
Technology Transfer Automated Retrieval System (TEKTRAN)
Two natural antioxidants, sesamol and omega-oryzanol, were examined for their antioxidant activity towards omega-3 oil. Sesamol and omega-oryzanol have been known to provide antioxidant effects at high temperatures such as those used for frying. In this study, the effects of 0.84 mM and 8.4 mM oryza...
11. Estimating [omega][subscript h] for Structures Containing Two Group Factors: Perils and Prospects
ERIC Educational Resources Information Center
Zinbarg, Richard E.; Revelle, William; Yovel, Iftah
2007-01-01
One of the most serious difficulties in the estimation of omega[subscript hierarchical] ([omega][subscript h]) has not been previously studied. Although it is true that one can impose a set of identifying constraints on one's solution to derive an estimate of [omega][subscript h] in the two-group factor case, there is the potential for introducing…
12. Reverse bias voltage testing of 8 cm x 8cm silicon solar cells
NASA Technical Reports Server (NTRS)
Woike, T.; Stotlar, S.; Lungu, C.
1991-01-01
A study is described of the reverse I-V characteristics of the largest space qualified silicon solar cells currently available (8 x 8 cm) and of reverse bias voltage (RBV) testing performed on these cells. This study includes production grade cells, both with and without cover glass. These cells span the typical output range seen in production. Initial characteristics of these cells are measured at both 28 and 60 C. These measurements show weak correlation between cell output and reverse characteristics. Analysis is presented to determine the proper conditions for RBV stress to simulate shadowing effects on a particular array design. After performing the RBV stress the characteristics of the stressed cells are remeasured. The degradation in cell performance is highly variable which exacerbates cell mismatching over time. The effect of this degradation on array lifetime is also discussed. Generalization of these results to other array configurations is also presented.
13. Chrysanthemum CmNAR2 interacts with CmNRT2 in the control of nitrate uptake
PubMed Central
Gu, Chunsun; Zhang, Xiaoxue; Jiang, Jiafu; Guan, Zhiyong; Zhao, Shuang; Fang, Weimin; Liao, Yuan; Chen, Sumei; Chen, Fadi
2014-01-01
Nitrate transporters are an important component of plant growth and development. Chrysanthemum morifolium is an important ornamental species, for which a sufficient supply of nitrogenous fertilizer is required to maintain economic yields. In this study, the full-length cDNA of the nitrate transporter genes CmNRT2 and CmNAR2 were isolated. CmNRT2 transcript accumulation was inducible by both nitrate and ammonium, but the latter ion down-regulated the transcript accumulation of CmNAR2. CmNRT2 might be a plasma membrane localized protein, while CmNAR2 was distributed throughout the cell. CmNAR2 was shown to interact with CmNRT2 by in vitro and in vivo assays. Arabidopsis thaliana plants heterologously expressing CmNRT2 showed an increased rate of nitrate influx, while this trait was unaltered in plants expressing CmNAR2. Double transformants (CmNRT2 plus CmNAR2) exhibited an enhanced rate of nitrate influx into the root. Our data indicated that the interaction of CmNAR2 with CmNRT2 contributed to the uptake of nitrate. PMID:25060485
14. The least-action method, cold dark matter, and omega
NASA Technical Reports Server (NTRS)
Dunn, A. M.; Laflamme, R.
1995-01-01
Peebles has suggested an interesting technique, called the least-action method, to trace positions of galaxies back in time. This method applied on the Local Group galaxies seems to indicate that we live in an omega approximately = 0.1 universe. We have studied a cold dark matter (CDM) N-body simulation with omega = 0.2 and H = 50 km/s/Mpc and compared trajectories traced back by the least-action method with the ones given by the center of mass of the CDM halos. We show that the agreement between these sets of trajectories is at best qualitative. We also show that the line-of-sight peculiar velocities of halos are underestimated. This discrepancy is due to orphans, i.e., CDM particles which do not end up in halos. We vary the value of omega in the least-action method until the line-of-sight velocities agree with the CDM ones. The best value for this omega underestimates one of the CDM simulations by a factor of 4-5.
15. Omega-3 fatty acids for breast cancer prevention and survivorship.
PubMed
Fabian, Carol J; Kimler, Bruce F; Hursting, Stephen D
2015-05-04
Women with evidence of high intake ratios of the marine omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to the omega-6 arachidonic acid have been found to have a reduced risk of breast cancer compared with those with low ratios in some but not all case-control and cohort studies. If increasing EPA and DHA relative to arachidonic acid is effective in reducing breast cancer risk, likely mechanisms include reduction in proinflammatory lipid derivatives, inhibition of nuclear factor-κB-induced cytokine production, and decreased growth factor receptor signaling as a result of alteration in membrane lipid rafts. Primary prevention trials with either risk biomarkers or cancer incidence as endpoints are underway but final results of these trials are currently unavailable. EPA and DHA supplementation is also being explored in an effort to help prevent or alleviate common problems after a breast cancer diagnosis, including cardiac and cognitive dysfunction and chemotherapy-induced peripheral neuropathy. The insulin-sensitizing and anabolic properties of EPA and DHA also suggest supplementation studies to determine whether these omega-3 fatty acids might reduce chemotherapy-associated loss of muscle mass and weight gain. We will briefly review relevant omega-3 fatty acid metabolism, and early investigations in breast cancer prevention and survivorship.
16. Prevention of Sports Injuries by Marine Omega-3 Fatty Acids.
PubMed
Bryhn, Morten
2015-01-01
Sport injuries are common and costly for the professional athlete, the "weekend warrior," and the community. Acute injuries are treated according to current guidelines with the aim of bringing the athlete back into the arena. These guidelines have not taken into account new scientific results of the inflammatory process following a trauma. The 4 hallmarks of inflammation, namely, pain, swelling, redness, and heat, are results of an adequate inflammatory response with the aim of bringing the affected tissue back to restitution (Latin: restitutio ad integrum). Cooling of the affected limb and anti-inflammatory drugs are widely used but may deter healing. The healing process is governed by fatty acids of the omega-3 and omega-6 series. In order to facilitate healing, these fatty acids have to be present in significant amounts in the affected tissues before the trauma occurs. This is particularly relevant for marine omega-3 fatty acids, which are often running low due to insignificant intake of seafood, common in individuals practicing sports. High-energy sports often lead to head and brain trauma. Continuous head traumata may even result in later mental defects. Saturation of brain cells with omega-3 fatty acids, in particular docosahexaenoic acid (DHA), may facilitate healing after brain trauma, thereby counteracting negative long-term results. The present understanding of a normal inflammatory process leading to restitution will be discussed along with data from recent scientific trials.
17. High-Energy Petawatt Capability for the Omega Laser
SciTech Connect
Waxer, L.J.; Maywar, D.N.; Kelly, J.H.; Kessler, T.J.; Kruschwitz, B.E.; Loucks, S.J.; McCrory, R.L.; Meyerhofer, D.D.; Morse, S.F.B.; Stoeckl, C.; Zuegel, J.D.
2005-07-25
The 60-beam Omega laser system at the University of Rochester's Laboratory for Laser Energetics (LLE) has been a workhorse on the frontier of laser fusion and high-energy-density physics for more than a decade. LLE scientists are currently extending the performance of this unique, direct-drive laser system by adding high-energy petawatt capabilities.
18. A picosecond beam-timing system for the OMEGA laser
DOE PAGES
Donaldson, W. R.; Katz, J.; Huff, R.; ...
2016-05-27
Here, a timing system is demonstrated for the OMEGA Laser System that guarantees all 60 beams will arrive on target simultaneously with a root mean square variability of 4 ps. The system relies on placing a scattering sphere at the target position to couple the UV light from each beam into a single photodetector.
19. Do we need 'new' omega-3 polyunsaturated fatty acids formulations?
PubMed
Cicero, Arrigo F G; Morbini, Martino; Borghi, Claudio
2015-02-01
The therapeutic value of omega-3 polyunsaturated fatty acids (PUFAs), mainly (but not only) found in fish oils, eicosapentaenoic and docosahexaenoic acids (EPA and DHA, respectively), has been extensively studied in a wide variety of disease conditions, predominantly in cardiovascular disease. However, the significant difference in efficacy observed in various conditions with different dosages seems to be at least partly related to the large discrepancy in quality of the product and to the bioavailability of the omega-3 PUFA. The research of new sources (e.g., from arctic Krill oil) and pharmaceutical forms of omega-3 PUFA (e.g., omega-3 carboxylic acids) is needed in order to detect the one with the best bioavailability and efficacy, and with a parallel reduction in the production costs. There is also the need to understand if long-term PUFA supplementation could increase the efficacy of the already-available evidence-based therapies for cardiovascular disease prevention and for the management of the diseases where the use of PUFA could have a possible improving effect.
20. Maternal micronutrients, omega-3 fatty acids, and placental PPARγ expression.
PubMed
Meher, Akshaya P; Joshi, Asmita A; Joshi, Sadhana R
2014-07-01
An altered one-carbon cycle is known to influence placental and fetal development. We hypothesize that deficiency of maternal micronutrients such as folic acid and vitamin B12 will lead to increased oxidative stress, reduced long-chain polyunsaturated fatty acids, and altered expression of peroxisome proliferator activated receptor (PPARγ) in the placenta, and omega-3 fatty acid supplementation to these diets will increase the expression of PPARγ. Female rats were divided into 5 groups: control, folic acid deficient, vitamin B12 deficient, folic acid deficient + omega-3 fatty acid supplemented, and vitamin B12 deficient + omega-3 fatty acid supplemented. Dams were dissected on gestational day 20. Maternal micronutrient deficiency leads to lower (p < 0.05) levels of placental docosahexaenoic acid, arachidonic acid, PPARγ expression and higher (p < 0.05) levels of plasma malonidialdehyde, placental IL-6, and TNF-α. Omega-3 fatty acid supplementation to a vitamin B12 deficient diet normalized the expression of PPARγ and lowered the levels of placental TNF-α. In the case of supplementation to a folic acid deficient diet it lowered the levels of malonidialdehyde and placental IL-6 and TNF-α. This study has implications for fetal growth as oxidative stress, inflammation, and PPARγ are known to play a key role in the placental development.
1. Quark diagrams and the. cap omega. /sup -/ nonleptonic decays
SciTech Connect
Ponce, W.A.
1980-09-01
The quark-diagram model for nonleptonic two-body baryon decays is discussed and applied to the decay of the ..cap omega../sup -/ particle. Current algebra is not employed, but the relation between the quark diagrams and current algebra is explored.
2. Omega-3 fatty acids: a novel resort against gastrointestinal injury.
PubMed
Ianiro, G; Franceschi, F; Bibbò, S; Gasbarrini, A
2014-10-01
The integrity of gastric barrier derives from the balance between defending and damaging factors. In particular, prostaglandins play a relevant role in the maintenance of gastric homeostasis and prevention of peptic disease, at different levels. Omega-3 fatty acids, particularly eicosapentanoic acid, are the precursors of the third series of prostaglandins (with anti-inflammatory properties), also reducing the formation of the second series of prostaglandins (pro-inflammatory ones). Such a pathophysiological rationale brought to the experimental application, both in animal models and, more recently, in humans, of omega-3 fatty acids against gastrointestinal damage. Omega-3 fatty acids have shown interesting results in preventing different types of gastric damage in mouse models. A large retrospective case-control study on patients taking both anti-thrombotic therapy and eicosapentanoic acid showed (although only at unadjusted analysis) an inverse correlation between consumption of eicosapentanoic acid and gastrointestinal injury. Prospective, well-designed, comparative studies are warranted to clarify if omega-3 fatty acids may represent, or not, a novel resort against gastrointestinal injury.
3. An algorithm for the automatic synchronization of Omega receivers
NASA Technical Reports Server (NTRS)
Stonestreet, W. M.; Marzetta, T. L.
1977-01-01
The Omega navigation system and the requirement for receiver synchronization are discussed. A description of the synchronization algorithm is provided. The numerical simulation and its associated assumptions were examined and results of the simulation are presented. The suggested form of the synchronization algorithm and the suggested receiver design values were surveyed. A Fortran of the synchronization algorithm used in the simulation was also included.
4. Coefficients Alpha, Beta, Omega, and the glb: Comments on Sijtsma
ERIC Educational Resources Information Center
Revelle, William; Zinbarg, Richard E.
2009-01-01
There are three fundamental problems in Sijtsma ("Psychometrika," 2008): (1) contrary to the name, the glb is not the greatest lower bound of reliability but rather is systematically less than omega[subscript t] (McDonald, "Test theory: A unified treatment," Erlbaum, Hillsdale, 1999), (2) we agree with Sijtsma that when considering how well a test…
5. Omega-3 polyunsaturated fatty acids and oxygenated metabolism in atherothrombosis.
PubMed
Guichardant, Michel; Calzada, Catherine; Bernoud-Hubac, Nathalie; Lagarde, Michel; Véricel, Evelyne
2015-04-01
Numerous epidemiological studies and clinical trials have reported the health benefits of omega-3 polyunsaturated fatty acids (PUFA), including a lower risk of coronary heart diseases. This review mainly focuses on the effects of alpha-linolenic (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on some risk factors associated with atherothrombosis, including platelet activation, plasma lipid concentrations and oxidative modification of low-density lipoproteins (LDL). Special focus is given to the effects of marine PUFA on the formation of eicosanoids and docosanoids, and to the bioactive properties of some oxygenated metabolites of omega-3 PUFA produced by cyclooxygenases and lipoxygenases. The antioxidant effects of marine omega-3 PUFA at low concentrations and the pro-oxidant effects of DHA at high concentrations on the redox status of platelets and LDL are highlighted. Non enzymatic peroxidation end-products deriving from omega-3 PUFA such as hydroxy-hexenals, neuroketals and EPA-derived isoprostanes are also considered in relation to atherosclerosis. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".
6. Avery D. Weisman, M.D.: An Omega Interview.
ERIC Educational Resources Information Center
Omega: Journal of Death and Dying, 1993
1993-01-01
In this interview, Avery D. Weisman, M.D., distinguished contributor to study of human encounter with death, discusses personal and professional facets of his long and productive career. Includes review of his concepts of appropriate death and middle knowledge; and findings of Project Omega, clinical research study directed by Weisman for 18…
7. A 1.3 cm line survey toward Orion KL
Gong, Y.; Henkel, C.; Thorwirth, S.; Spezzano, S.; Menten, K. M.; Walmsley, C. M.; Wyrowski, F.; Mao, R. Q.; Klein, B.
2015-09-01
regions. Elemental and isotopic abundance ratios are also estimated: He/H = (8.7 ± 0.7)% derived from the ratios between helium RRLs and hydrogen RRLs; 12C/13C = 63 ± 17 from 12CH3OH/13CH3OH; 14N/15N =100 ± 51 from 14NH3/15NH3; and D/H = (8.3 ± 4.5) × 10-3 from NH2D/NH3. The dispersion of the He/H ratios derived from Hα/Heα pairs to Hδ/Heδ pairs is very small, which is consistent with theoretical predictions that the departure coefficients bn factors for hydrogen and helium are nearly identical. Based on a non-LTE code that neglects excitation by the infrared radiation field and a likelihood analysis, we find that the denser regions have lower kinetic temperature, which favors an external heating of the hot core. Tables 2 and 4 and appendices are available in electronic form at http://www.aanda.orgThe reduced spectra as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/581/A48
8. Effect of dietary omega-3 and omega-6 fatty acids on clotting activities of Factor V, VII and X in fatty liver haemorrhagic syndrome-susceptible laying hens.
PubMed
Yeh, E; Wood, R D; Leeson, S; Squires, E J
2009-05-01
1. The relationship between concentrations of omega-3 and omega-6 fatty acids in plasma and Factor V, VII and X clotting activities was determined using a crossover feeding trial with diets supplemented with either soy oil or flax oil. 2. Laying hens on the soy diet, which is high in omega-6 fatty acids, had substantially higher clotting activity for all three factors compared to laying hens on the flax diet that was high in omega-3 fatty acids. 3. Positive associations were seen between liver haemorrhage score and the percentage of liver weight and between the percentage of liver weight and the severity of haemorrhagic and fatty changes seen on histology. 4. These results support the hypothesis that concentrations of omega-6 and omega-3 fatty acids in plasma affect clotting activity; however, there was no relationship between the extent of liver haemorrhages and the composition of plasma fatty acids.
9. Improving the hot-spot pressure and demonstrating ignition hydrodynamic equivalence in cryogenic deuterium–tritium implosions on OMEGA
SciTech Connect
Goncharov, V. N.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Follett, R. K.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu.; Harding, D. R.; Henchen, R. J.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H.; and others
2014-05-15
Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of α ≃ 4, an implosion velocity of 3.8 × 10{sup 7} cm/s, and a laser intensity of ∼10{sup 15} W/cm{sup 2}. These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.
10. Omega-3/Omega-6 Fatty Acids for Attention Deficit Hyperactivity Disorder: A Randomized Placebo-Controlled Trial in Children and Adolescents
ERIC Educational Resources Information Center
Johnson, Mats; Ostlund, Sven; Fransson, Gunnar; Kadesjo, Bjorn; Gillberg, Christopher
2009-01-01
Objective: The aim of the study was to assess omega 3/6 fatty acids (eye q) in attention deficit hyperactivity disorder (ADHD). Method: The study included a randomized, 3-month, omega 3/6 placebo-controlled, one-way crossover trial with 75 children and adolescents (8-18 years), followed by 3 months with omega 3/6 for all. Investigator-rated ADHD…
11. Mars surface thermal inertia and heterogeneities from OMEGA/MEX
Audouard, J.; Poulet, F.; Vincendon, M.; Bibring, J.-P.; Forget, F.; Langevin, Y.; Gondet, B.
2014-05-01
The thermophysical structure of the martian surface is the result of various processes that have shaped the martian surface through time. Previous dedicated heliosynchronous measurements of the thermal infrared (IR) flux of the martian surface have revealed the diversity of martian surface thermal properties, as well as its complexity linked to the heterogeneous nature of terrains. We present the first retrieval of thermophysical properties of the martian surface using near-infrared (NIR) Observatoire pour la Minéralogie, l’Eau, les Glaces et l’Activité (OMEGA) onboard Mars Express (MEX) thermal measurements from 5 to 5.1 μm. MEX orbit around Mars is elliptical and therefore OMEGA has performed surface temperature measurements at various local times and seasons over more than 4 full martian years. We have developed a method to exploit these unprecedented measurements using a one-dimensional energy balance code derived from a Global Climate Model that allows retrieval of the thermal properties of the martian surface using OMEGA data. Regional maps of the thermal inertia at a resolution up to 32 pixels per degree and a global map at 4 pixels per degree are presented. OMEGA-derived thermal inertia values agree with previous mappings by the Thermal Emission Spectrometer (TES) onboard Mars Global Surveyor (MGS) and Thermal Emission Imaging Spectrometer (THEMIS) onboard Mars Odyssey and highlight the key role of dust for the thermal behavior of the martian surface. OMEGA directly reveals for the first time some diurnal variations of apparent TI attributable to surface heterogeneities at macroscopic scale and enables to quantify these heterogeneities. In Nili Patera and Tharsis, local surface heterogeneities are modeled with layering and horizontal admixture of divergent slopes respectively.
12. The OMEGA Instrument on board Mars Express: First Results
Bellucci, G.; Altieri, F.; Bibring, J. P.; OMEGA Team
OMEGA (Observatoire pour la Mineralogie, l'Eau, le Glace e l'Activité) is a visible and near infrared mapping spectrometer, operating in the spectral range (0.35 - 5.1 μm). Combining imagery and spectrometry, OMEGA is designed to provide the mineralogical and molecular composition of the surface and atmosphere of Mars through the spectral analysis of the diffused solar light and surface thermal emission. OMEGA will provide a global coverage at medium resolution (2 to 5 km) of the entire surface of Mars from altitudes 1500 to 4000 km, and high resolution (< 400 m) spectral images of selected areas, amounting to a few percents of the surface, when observed close to periapsis (< 300 km altitude). OMEGA will address major questions associated to internal structure, geologic and chemical evolution, past activity and present surface variegation. It will greatly contribute to the understanding of the evolution of Mars from geological time scales to seasonal variations. It will in particular give unique clues for understanding the H2O and CO2 cycles over the Mars history. It will play a major role in identifying areas of interest for the future martian in situ explorations. OMEGA is an international collaboration between France, Italy and Russia, involving the following Institutions: IAS (Institut d'Astrophysique Spatiale, Orsay, France), DESPA (Département de Recherches Spatiales, Observatoire de Paris/Meudon, France), IFSI (Istituto di Fisica dello Spazio Interplanetario, Rome, Italy) and IKI (Institute for Space Research, Moscow, Russia). In this paper we present the first results after few months from starting of its observations.
13. Effect of inorganic salts on bacterial omega-3 PUFA production.
PubMed
Abd Elrazak, Ahmed; Ward, Alan C; Glassey, Jarka
2017-03-16
The increasing demand of omega-3 in the market and the challenges facing its conventional supplies led to an increasing interest to microbial omega-3 sources. This research concentrates on the statistical role of some metal ions on the biosynthesis and productivity of eicosapentaenoic acid (essential omega-3 element) in bacterial isolate, Shewanella 717. A Plackett-Burman design was applied to screen the main effect of all metal salts entrenched in the artificial sea water medium components. Four salts, in particular, in addition to the interaction among them were highlighted as having a statistically significant effect upon the growth and/or eicosapentaenoic acid production. A subsequent central composite design was performed to determine the exact optimum concentration of each of the chosen variables which was found to be 2.5, 1.8, 1.2, and 23 g/l, for Na2HPO4, MgSO4, KCl, and NaCl, respectively. All the experiments were performed with the minimal amount of carbon and nitrogen to eliminate any potential masking effect. A bioreactor batch run was operated and the ion uptake was monitored, using EDAX® electron microscopy, concluding that the process of microbial omega-3 production could be a phosphate-limited process. Optimizing the concentration of the tested metal ions led to a remarkable increase in the omega-3 productivity resulted in a 30, 9, and 10 times increase in yield, concentration, and percentage to the total fatty acids, respectively, even though the carbon and nitrogen were kept constant all over the research work.
14. Omega-3 fatty acids: proven benefit or just a "fish story"?
PubMed
Martin, Caren McHenry
2008-03-01
The potential health benefit of omega-3 fatty acids has been the focus of much research in the past decade. While the typical diet in the United States has a much greater ratio of omega-6 fatty acids compared with omega-3 fatty acids, research is showing that shifting this ratio-by increased consumption of fatty fish or fish oil supplements-may provide significant health benefits. Reductions in cardiovascular risk, depression, and rheumatoid arthritis symptoms have been correlated with omega-3 fatty acid intake, and there is increased interest in the use of omega-3 fatty acid supplementation for other psychiatric illnesses and prevention of Alzheimer's disease.
15. Measurements of CP-Violating Asymmetries and BranchingFractions in B Decays to omegaK and omegaPi
SciTech Connect
Aubert, B.
2006-03-23
We present measurements of CP-violating asymmetries and branching fractions for the decays B{sup +} {yields} {omega}{pi}{sup +}, B{sup +} {yields} {omega}K{sup +}, and B{sup 0} {yields} {omega}K{sup 0}. The data sample corresponds to 232 million B{bar B} pairs produced by e{sup +}e{sup -} annihilation at the {Upsilon}(4S) resonance. For the decay B{sup 0} {yields} {omega}K{sub s}{sup 0}, we measure the time-dependent CP-violation parameters S = 0.51{sub -0.39}{sup +0.35} {+-} 0.02, and C = -0.55{sub -0.26}{sup +0.28} {+-} 0.03. We also measure the branching fractions, in units of 10{sup -6}, {Beta}(B{sup +} {yields} {omega}{pi}{sup +}) = 6.1 {+-} 0.7 {+-} 0.4, {Beta}(B{sup +} {yields} {omega}K{sup +}) = 6.1 {+-} 0.6 {+-} 0.4, and {Beta}(B{sup 0} {yields} {omega}K{sup 0}) = 6.2 {+-} 1.0 {+-} 0.4, and charge asymmetries {Alpha}{sub ch}(B{sup +} {yields} {omega}{pi}{sup +}) = -0.01 {+-} 0.10 {+-} 0.01 and {Alpha}{sub ch}(B{sup +} {yields} {omega}K{sup +}) = 0.05 {+-} 0.09 {+-} 0.01.
16. Detection of omega-3 oxylipins in human plasma and response to treatment with omega-3 acid ethyl esters
Technology Transfer Automated Retrieval System (TEKTRAN)
The long chain omega-3 fatty acids (n-3 FAs), eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids have beneficial health effects, but the molecular mediators of these effects are not well-characterized. Oxygenated n-3 FAs (oxylipins) may be an important class of mediators. Members of this chemic...
17. Reduction of omega-3 oil oxidation in stable emulsion of caseinate-omega-3 oil-oat beta-glucan
Technology Transfer Automated Retrieval System (TEKTRAN)
Lipid oxidation, particularly oxidation of unsaturated fatty acids such as omega-3 fatty acids, has posed a serious challenge to the food industry trying to incorporate heart-healthy oil products into their lines of healthful foods and beverages. In this study, heart healthy plant and marine based o...
18. Omega Omega and Proton-Antiproton Production in Two Photon Interactions at ARGUS
Tsipolitis, George
1990-01-01
The reactions gammagamma to 2pi^+2pi ^-2pi^0 and gamma gammatopi^+pi^-pi ^0pi^0 have been studied by using the ARGUS detector at the e^+e^ - storage ring DORIS II at DESY. In the 2pi^+2pi^ -2pi^0 final state the production of omega-mesons is observed and in particular the reaction gammagamma to omegaomega is seen for the first time. The cross section for gammagamma to omegaomega is found to have an enhancement at ~1.9GeV/c ^2 of about 12 nb. The topological cross sections for the reactions gammagamma to 2pi^+2 pi^-2pi^0 and gammagamma to omegapi^+pi^-pi ^0 are also measured. The production of charged rho -mesons is observed in the pi^+pi ^-pi^0pi^0 final state. The cross section for the reaction gamma gamma to rho ^+rho^- is measured for the first time. The cross section did not show a threshold enhancement similar to that found in the reaction gammagamma to rho^0rho^0 and is about a factor of four smaller. A spin parity analysis of the rho^+rho^- system shows that the cross section is dominated by the two amplitudes J^{P} = 0^+ and J^{P } = 2^+ with helicity 2.
19. On the possibility of an alpha-sq omega-type dynamo in a thin layer inside the sun
NASA Technical Reports Server (NTRS)
Choudhuri, Arnab Rai
1990-01-01
If the solar dynamo operates in a thin layer of 10,000-km thickness at the interface between the convection zone and the radiative core, using the facts that the dynamo should have a period of 22 years and a half-wavelength of 40 deg in the theta-direction, it is possible to impose restrictions on the values which various dynamo parameters are allowed to have. It is pointed out that the dynamo should be of alpha-sq omega nature, and kinematical calculations are presented for free dynamo waves and for dynamos in thin rectangular slabs with appropriate boundary conditions. An alpha-sq omega dynamo is expected to produce a significant poloidal field which does not leak to the solar surface. It is found that the turbulent diffusity eta and alpha-coefficient are restricted to values within about a factor of 10, the median values being eta of about 10 to the 10th sq cm/sec and alpha of about 10 cm/sec. On the basis of mixing length theory, it is pointed out that such values imply a reasonable turbulent velocity of the order 30 m/s, but rather small turbulent length scales like 300 km.
20. Using gamma-ray emission to measure ablator areal density of imploded capsules at the Omega laser
Hoffman, N.; Rubery, M.; Herrmann, H.; Kim, Y.; Young, C.; Mack, J.; Wilson, D.; McEvoy, A.; Evans, S.; Sedillo, T.; Stoeffl, W.; Horsfield, C.; Glebov, V.
2010-11-01
We have measured the ablator areal density of plastic-shell implosions at the Omega laser, using gamma-ray emission from the capsules detected by the prototype Gamma Reaction History (GRH) diagnostic. The intensity of 4.44-MeV gamma emission from ^12C nuclei in the ablator is proportional to the product of ablator areal density and yield of fusion neutrons, so by detecting the gammas we can infer the ablator areal density, provided we also have a measurement of total neutron yield. Neutron yield is determined from the nTOF experiment at Omega in our approach; alternatively one could use 16.7-MeV gammas from DT fusion. Inferred values of time-averaged carbon areal density are in the range 10-30 mg/cm^2, for a range of implosions. These values are smaller than predicted values based on 1D simulations, which are typically in the range 30-40 mg/cm^2. We discuss possible reasons for the discrepancy, primarily related to mixing.
1. Low-energy {omega} ({yields}{pi}{sup 0}{gamma}) meson photoproduction in the nucleus
SciTech Connect
Das, Swapan
2011-06-15
The {pi}{sup 0{gamma}} invariant mass distribution spectra in the ({gamma},{pi}{sup 0{gamma}}) reaction were measured by the TAPS/ELSA Collaboration to look for the hadron parameters of the {omega} meson in the Nb nucleus. We study the mechanism for this reaction, where we consider that the elementary reaction in the Nb nucleus proceeds as {gamma}N{yields}{omega}N;{omega}{yields}{pi}{sup 0}{gamma}. The {omega}-meson photoproduction amplitude for this reaction is extracted from the measured four-momentum transfer distribution in the {gamma}p{yields}{omega}p reaction. The propagation of the {omega} meson and the distorted wave function for the {pi}{sup 0} meson in the final state are described by the eikonal form. The {omega} and {pi}{sup 0} mesons' nucleus optical potentials, appearing in the {omega} meson propagator and {pi}{sup 0} meson distorted wave function respectively, are estimated using the t{rho} approximation. The effects of pair correlation and color transparency are also studied. The calculated results do not show medium modification for the {omega} meson produced in the nucleus for momentum greater than 200 MeV. It occurs because the {omega} meson predominantly decays outside the nucleus. The dependence of the cross section on the final-state interaction is also investigated. The broadening of the {omega}-meson mass distribution spectra is shown to occur due to the large resolution width associated with the detector used in the experiment.
2. Omega-3 Fatty Acid and Nutrient Deficits in Adverse Neurodevelopment and Childhood Behaviors
PubMed Central
Hibbeln, Joseph. R.; Gow, Rachel V.
2014-01-01
Synopsis Nutritional insufficiencies of omega-3 highly unsaturated fatty acids (HUFAs) may have adverse effects on brain development and neurodevelopmental outcomes. A recent meta-analysis of ten randomized controlled trials of omega-3 HUFAs reported a small to modest effect size for the efficacy of omega-3 for treating symptoms of ADHD in youth. Several controlled trials of omega-3 HUFAs combined with micronutrients (vitamins, minerals) show sizeable reductions in aggressive, antisocial, and violent behavior in youth and in young adult prisoners. Meta-analyses report efficacy for depressive symptoms in adults, and preliminary findings suggest anti-suicidal properties in adults, but studies in youth are insufficient to draw any conclusions regarding mood. Dietary adjustments to increase omega-3 and reduce omega-6 HUFA consumption are sensible recommendations for youth and adults based on general health considerations, while the evidence base for omega-3 HUFAs as potential psychiatric treatments develops. PMID:24975625
3. Vitamin E supplementation modulates the biological effects of omega-3 fatty acids in naturally aged rats.
PubMed
Narayanankutty, Arunaksharan; Kottekkat, Anagha; Mathew, Shaji E; Illam, Soorya P; Suseela, Indu M; Raghavamenon, Achuthan C
2017-03-01
Omega-3 fatty acids are well-known class of nutraceuticals with established health benefits. Recently, the oxidation products of these fatty acids are gaining attention, as they are likely to disturb body redox balance. Therefore, the efficacy of omega-3 fats under conditions of diminished antioxidant status, such as aging, is always a concern. Present study assessed the effects of omega-3 fats (DHA and EPA) together with or without vitamin-E in naturally aged rats. It was found that in omega-3 fats alone consumed rats the lipid profile was improved, while in omega-3 fat with vitamin-E-consumed group (OMVE), the hepato protective and antioxidant properties were pronounced, especially the redox status of brain tissue. It is possible that vitamin-E might have reduced the peroxidation of omega-3 fats, thereby allowing their synergistic effects. Hence, the use of vitamin-E along with omega-3 fat may be beneficial under aged conditions.
4. Prediction of peroxide value in omega-3 rich microalgae oil by ATR-FTIR spectroscopy combined with chemometrics.
PubMed
Cebi, Nur; Yilmaz, Mustafa Tahsin; Sagdic, Osman; Yuce, Hande; Yelboga, Emrah
2017-06-15
Our work explored, for the first time, monitoring peroxide value (PV) of omega-3 rich algae oil using ATR-FTIR spectroscopic technique. The PV of the developed method was compared by that obtained by standard method of Association of Official Analytical Chemists (AOAC). In this study, peak area integration (PAI), Partial Least Squares Regression (PLSR), and Principal Component Regression (PCR) were used as the calibration techniques. PV obtained by the AOAC method and by FTIR-ATR technique were well correlated considering the peak area related to trans double bonds and chemometrics techniques of PLSR and PCR. Calibration model was established using the band with a peak point at 966cm(-1) (990-940cm(-1)) related to CH out of plane deformation vibration of trans double bond. Algae oil oxidation could be successfully quantified using PAI, PLSR and PCR techniques. Additionally, hierarchical cluster analysis was performed and significant discrimination was observed coherently with oxidation process.
5. Omega-3 fatty acids and incident type 2 diabetes: the Singapore Chinese Health Study1234
PubMed Central
Brostow, Diana P; Odegaard, Andrew O; Koh, Woon-Puay; Duval, Sue; Gross, Myron D; Yuan, Jian-Min; Pereira, Mark A
2011-01-01
Background: The role of omega-3 (n–3) fatty acids (FAs) in the development of type 2 diabetes is uncertain, especially with regard to any differential influence of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Objective: The objective was to examine the association between total omega-3 FAs, marine omega-3 (EPA, DHA), nonmarine omega-3 (ALA), and omega-6 (n–6) FAs and omega-6:omega-3 ratio and risk of type 2 diabetes in a Chinese population in Singapore. Design: The analysis included 43,176 Chinese men and women free of chronic disease, aged 45–74 y, in the Singapore Chinese Health Study. Baseline data collection occurred between 1993 and 1998, with follow-up interviews between 1999 and 2004. Cox regression models were used to examine the associations between FA intakes at baseline and risk of developing diabetes. Results: Increased intakes of total omega-3 FAs were inversely associated with diabetes incidence [hazard ratio (HR) for the fifth compared with the first quintile: 0.78; 95% CI: 0.65, 0.94; P for trend = 0.02]. Omega-3 FAs from marine sources were not associated with diabetes risk, whereas nonmarine omega-3 FA intake was strongly associated (HR for the fifth compared with the first quintile: 0.79; 95% CI: 0.67, 0.93; P for trend = 0.004). Omega-6 and omega-6:omega-3 ratio were not associated with incidence of type 2 diabetes. Conclusion: Consumption of nonmarine sources (ALA) of omega-3 FAs is associated with a decreased risk of type 2 diabetes in Chinese Singaporeans. PMID:21593505
6. Omega-3 and omega-6 Fatty acids in blood and breast tissue of high-risk women and association with atypical cytomorphology.
PubMed
Hidaka, Brandon H; Li, Shengqi; Harvey, Katherine E; Carlson, Susan E; Sullivan, Debra K; Kimler, Bruce F; Zalles, Carola M; Fabian, Carol J
2015-05-01
The ratio of omega-3 to omega-6 fatty acids, especially the long-chain eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) to arachidonic acid (AA) ratio, is inversely associated with breast cancer risk. We measured the association between cytologic atypia, a biomarker for short-term risk of breast cancer development, and omega-3 and omega-6 fatty acid intake and levels in blood and breast tissue. Blood and benign breast tissue, sampled by random periareolar fine-needle aspiration (RPFNA), was obtained from 70 women at elevated risk for breast cancer. Self-reported dietary intake was assessed by the NCI's Food Frequency Questionnaire. The fatty acid composition of five lipid compartments, red blood cell, plasma and breast phospholipids, and plasma and breast triaclyglycerides (TAG), was analyzed by gas chromatography as weight percent. Median daily intakes of EPA+DHA and total omega-3 fatty acids were 80 mg and 1.1 g, respectively. The median total omega-3:6 intake ratio was 1:10. Compared with women without atypia, those with cytologic atypia had lower total omega-3 fatty acids in red blood cell and plasma phospholipids and lower omega-3:6 ratios in plasma TAGs and breast TAGs (P < 0.05). The EPA+DHA:AA ratio in plasma TAGs was also lower among women with atypia. This is the first report of associations between tissue levels of omega-3 and omega-6 fatty acids and a reversible tissue biomarker of breast cancer risk. RPFNA cytomorphology could serve as a surrogate endpoint for breast cancer prevention trials of omega-3 fatty acid supplementation.
7. Double interpenetration in a chiral three-dimensional magnet with a (10,3)-a structure.
PubMed
Grancha, Thais; Mon, Marta; Lloret, Francesc; Ferrando-Soria, Jesús; Journaux, Yves; Pasán, Jorge; Pardo, Emilio
2015-09-21
A unique chiral three-dimensional magnet with an overall racemic double-interpenetrated (10,3)-a structure of the formula [(S)-(1-PhEt)Me3N]4[Mn4Cu6(Et2pma)12](DMSO)3]·3DMSO·5H2O (1; Et2pma = N-2,6-diethylphenyloxamate) has been synthesized by the self-assembly of a mononuclear copper(II) complex acting as a metalloligand toward Mn(II) ions in the presence of a chiral cationic auxiliary, constituting the first oxamato-based chiral coordination polymer exhibiting long-range magnetic ordering.
8. Design of a Production Process to Enhance Optical Performance of 3(omega) Optics
SciTech Connect
Prasad, R R; Bruere, J R; Halpin, J; Lucero, P; Mills, S; Bernacil, M; Hackel, R P
2003-11-01
Using the Phoenix pre-production conditioning facility we have shown that raster scanning of 3{omega} optics using a XeF excimer laser and mitigation of the resultant damage sites with a CO{sub 2} laser can enhance their optical damage resistance. Several large-scale (43 cm x 43 cm) optics have been processed in this facility. A production facility capable of processing several large optics a week has been designed based on our experience in the pre-production facility. The facility will be equipped with UV conditioning lasers--351-nm XeF excimer lasers operating at 100 Hz and 23 ns. The facility will also include a CO{sub 2} laser for damage mitigation, an optics stage for raster scanning large-scale optics, a damage mapping system (DMS) that images large-scale optics and can detect damage sites or precursors as small as {approx} 15 {micro}m, and two microscopes to image damage sites with {approx} 5 {micro}m resolution. The optics will be handled in a class 100 clean room, within the facility that will be maintained at class 1000.
9. Observation of the 63 micron (0 1) emission line in the Orion and Omega Nebulae
NASA Technical Reports Server (NTRS)
Melnick, G.; Gull, G. E.; Harwit, M.
1978-01-01
The 63 micron fine structure transition P4 : 3Pl yields 3P2 for neutral atomic oxygen was obtained during a series of flights at an altitude of approximately 13.7 km. In the Orion Nebula (M42), the observed line strength was 8 x 10 to the minus 15 power watt cm/2 which is estimated to be approximately 0.3 o/o of the energy radiated at all wavelengths. For the Omega Nebulae (M17), the line strength was 2.4 x 10 to the minus 15 power watt cm/2, and the fraction of the total radiated power was slightly higher. These figures refer to a 4' x 6' field of view centered on the peak for infrared emission from each source. The uncertainty in the line strength is approximately 50% and is caused by variable water vapor absorption along the flight path of the airplane. The line position estimate is 63.2 micron (+0.1, -0.2) micron. The prime uncertainty is due to the uncertain position of the (0 I) emitting regions in the field of view.
10. Crystal structure of the collagen triple helix model [(Pro-Pro-Gly)(10)](3).
PubMed
Berisio, Rita; Vitagliano, Luigi; Mazzarella, Lelio; Zagari, Adriana
2002-02-01
The first report of the full-length structure of the collagen-like polypeptide [(Pro-Pro-Gly)(10)](3) is given. This structure was obtained from crystals grown in a microgravity environment, which diffracted up to 1.3 A, using synchrotron radiation. The final model, which was refined to an R(factor) of 0.18, is the highest-resolution description of a collagen triple helix reported to date. This structure provides clues regarding a series of aspects related to collagen triple helix structure and assembly. The strict dependence of proline puckering on the position inside the Pro-Pro-Gly triplets and the correlation between backbone and side chain dihedral angles support the propensity-based mechanism of triple helix stabilization/destabilization induced by hydroxyproline. Furthermore, the analysis of [(Pro-Pro-Gly)(10)](3) packing, which is governed by electrostatic interactions, suggests that charges may act as locking features in the axial organization of triple helices in the collagen fibrils.
11. Effects of electron irradiation and temperature on 1 ohm-cm and 10 ohm-cm silicon solar cells
NASA Technical Reports Server (NTRS)
Nicoletta, C. A.
1973-01-01
One OHM-cm and 10 OHM-cm silicon solar cells were exposed to 1.0 MeV electrons at a fixed flux of 10 to the 11th power e/sq cm/sec and fluences of 10 to the 13th power, 10 to the 14th power and 10 to the 15th power e/sq.cm. 1-V curves of the cells were made at room temperature, - 63 C and + or - 143 C after each irradiation. A value of 139.5 mw/sq cm was used as AMO incident energy rate per unit area. The 10 OHM-cm cells appear more efficient than 1 OHM-cm cells after exposure to a fluence greater than 10 to the 14th power e/sq cm. The 1.0 MeV electron damage coefficients for both 1 OHM-cm and 10 OHM-cm cells are somewhat less than those for previously irradiated cells at room temperature. The values of the damage coefficients increase as the cell temperatures decrease. Efficiencies pertaining to maximum power output are about the same as those of n on p silicon cells evaluated previously.
12. Branching Fraction Measurement of B to omega l nu decays
SciTech Connect
Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.; So, R.Y.; Khan, A.; Blinov, V.E.; /more authors..
2012-06-13
We present a measurement of the B{sup +} {yields} {omega}{ell}{sup +}{nu} branching fraction based on a sample of 467 million B{bar B} pairs recorded by the BABAR detector at the SLAC PEP-II e{sup +}e{sup -} collider. We observe 1041 {+-} 133 signal decays, corresponding to a branching fraction of {Beta}(B{sup +} {yields} {omega}{ell}{sup +}{nu}) = (1.15 {+-} 0.15 {+-} 0.12) x 10{sup -4}, where the first error is statistical and the second is systematic. The dependence of the decay rate on q{sup 2}, the momentum transfer squared to the lepton system, is compared to QCD predictions of the form factors based on a quark model and light-cone sum rules.
13. Absorption of the {omega} and {phi} Mesons in Nuclei
SciTech Connect
Wood, M. H.; Nasseripour, R.; Berman, B. L.; Briscoe, W. J.; Munevar, E.; Strakovsky, I. I.; Paolone, M.; Djalali, C.; Gothe, R. W.; Graham, L.; Tedeschi, D. J.; Tkachenko, S.; Zhao, Z. W.; Weygand, D. P.; Batourine, V.; Burkert, V. D.; Carman, D. S.; Deur, A.; Guo, L.; Nadel-Turonski, P.
2010-09-10
Because of their long lifetimes, the {omega} and {phi} mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from {sup 2}H, C, Ti, Fe, and Pb targets. This Letter reports the first measurement of the ratio of nuclear transparencies for the e{sup +}e{sup -} channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the {omega} meson is stronger than that reported by the CBELSA-TAPS experiment and cannot be explained by recent theoretical models.
14. Omega Centauri - the glittering giant of the southern skies
2008-12-01
Omega Centauri is one of the finest jewels of the southern hemisphere night sky, as ESO's latest stunning image beautifully illustrates. Containing millions of stars, this globular cluster is located roughly 17 000 light-years from Earth in the constellation of Centaurus. Omega Centauri ESO PR Photo 44/08 The Glittering Giant Sparkling away at magnitude 3.7 and appearing nearly as large as the full moon on the southern night sky, Omega Centauri is visible with the unaided eye from a clear, dark observing site. Even through a modest amateur telescope, the cluster is revealed as an incredible, densely packed sphere of glittering stars. But astronomers need to use the full power of professional telescopes to uncover the amazing secrets of this beautiful globular cluster. This new image is based on data collected with the Wide Field Imager (WFI), mounted on the 2.2-metre diameter Max-Planck/ESO telescope, located at ESO's La Silla observatory, high up in the arid mountains of the southern Atacama Desert in Chile. Omega Centauri is about 150 light-years across and is the most massive of all the Milky Way's globular clusters. It is thought to contain some ten million stars! Omega Centauri has been observed throughout history. Both the great astronomer Ptolemy and later Johann Bayer catalogued the cluster as a star. It was not until much later, in the early 19th century, that an Englishman, the astronomer John Frederick William Herschel (son of the discoverer of Uranus), realised that Omega Centauri was in fact a globular cluster. Globular clusters are some of the oldest groupings of stars to be found in the halos that surround galaxies like our own Milky Way. Omega Centauri itself is thought to be around 12 billion years old. Recent research into this intriguing celestial giant suggests that there is a medium sized black hole sitting at its centre. Observations made with the Hubble Space Telescope (see heic0809 ) and the Gemini Observatory showed that stars at the
15. Unambiguous UML Composite Structures: The OMEGA2 Experience
Ober, Iulian; Dragomir, Iulia
Starting from version 2.0, UML introduced hierarchical composite structures, which are a very expressive way of defining complex software architectures, but which have a very loosely defined semantics in the standard. In this paper we propose a set of consistency rules that ensure UML composite structures are unambiguous and can be given a precise semantics. Our primary application of the static consistency rules defined in this paper is within the OMEGA UML profile [6], but these rules are general and applicable to other hierarchical component models based on the same concepts, such as MARTE GCM or SysML. The rule set has been formalized in OCL and is currently used in the OMEGA UML compiler.
16. Digital correlation detector for low-cost Omega navigation
NASA Technical Reports Server (NTRS)
Chamberlin, K. A.
1976-01-01
Techniques to lower the cost of using the Omega global navigation network with phase-locked loops (PLL) were developed. The technique that was accepted as being "optimal" is called the memory-aided phase-locked loop (MAPLL) since it allows operation on all eight Omega time slots with one PLL through the implementation of a random access memory. The receiver front-end and the signals that it transmits to the PLL were first described. A brief statistical analysis of these signals was then made to allow a rough comparison between the front-end presented in this work and a commercially available front-end to be made. The hardware and theory of application of the MAPLL were described, ending with an analysis of data taken with the MAPLL. Some conclusions and recommendations were also given.
17. OMEGA: The operational multiscale environment model with grid adaptivity
SciTech Connect
Bacon, D.P.
1995-07-01
This review talk describes the OMEGA code, used for weather simulation and the modeling of aerosol transport through the atmosphere. Omega employs a 3D mesh of wedge shaped elements (triangles when viewed from above) that adapt with time. Because wedges are laid out in layers of triangular elements, the scheme can utilize structured storage and differencing techniques along the elevation coordinate, and is thus a hybrid of structured and unstructured methods. The utility of adaptive gridding in this moded, near geographic features such as coastlines, where material properties change discontinuously, is illustrated. Temporal adaptivity was used additionally to track moving internal fronts, such as clouds of aerosol contaminants. The author also discusses limitations specific to this problem, including manipulation of huge data bases and fixed turn-around times. In practice, the latter requires a carefully tuned optimization between accuracy and computation speed.
18. Laser scattering from long scalelength plasmas on Omega. Final report
SciTech Connect
Drake, R.P.; Seka, W.; Craxton, R.S.; Bauer, B.S.
1998-12-31
In this project, the authors accomplished the tasks called for in the revised statement of work associated with this grant. Specifically, they accomplished: (1) active participation in the design of long-scalelength plasmas for Omega and in experiments to characterize these plasmas; (2) development of software that permits the rapid evaluation of laser-scattering diagnostic possibilities involving the standard parametric instabilities. It must be able to account for all 60 beams in Omega in addition to a probe beam and variable detector locations; and (3) design, purchase of components for, and assembly of instrumentation to make such measurements, providing for long-term versatility in the type of measurement. The project background and these accomplishments are discussed.
19. 3w Transmitted Beam Diagnostic at the Omega Laser Facility
SciTech Connect
Froula, D H; Rekow, V; Sorce, C; Piston, K; Knight, R; Alvarez, S; Griffith, R; Hargrove, D; Ross, J S; Dixit, S; Pollock, B; Divol, L; Glenzer, S H; Armstrong, W; Bahr, R; Thorp, K; Pien, G
2006-04-24
A 3{omega} transmitted beam diagnostic has been commissioned on the Omega Laser at the Laboratory for Laser Energetics, University of Rochester [Soures et.al., Laser Part. Beams 11 (1993)]. Transmitted light from one beam is collected by a large focusing mirror and directed onto a diagnostic platform. The near field of the transmitted light is imaged; the system collects information from twice the original f-cone of the beam. Two gated optical cameras capture the near field image of the transmitted light. Thirteen spatial positions around the measurement region are temporally resolved using fast photodiodes to allow a measure of the beam spray evolution. The Forward stimulated Raman scattering and forward simulated Brillion scattering are spectrally and temporally resolved at 5 independent locations within twice the original f-cone. The total transmitted energy is measured in two spectral bands ({delta}{lambda} < 400 nm and {delta}{lambda} > 400 nm).
20. Multidimensional Study of High-Adiabat OMEGA Cryogenic Experiments
Collins, T. J. B.; Betti, R.; Bose, A.; Christopherson, A. R.; Knauer, J. P.; Marozas, J. A.; Maximov, A. V.; Mora, A.; Radha, P. B.; Shang, W.; Shvydky, A.; Stoeckl, C.; Woo, K. M.; Varchas, G.
2016-10-01
Despite recent advances in modeling laser direct-drive inertial confinement fusion (ICF) experiments, there remains a predictability gap. This is particularly shown by the shortfall in hot-spot pressures inferred from OMEGA cryogenic implosions. To address this, a series of high-adiabat, cryogenic implosions were performed on OMEGA. These shots were performed with and without single-beam smoothing by spectral dispersion, at low and high drive intensities. These shots represent a regime where good agreement with simulation is expected because of the high adiabat. Multidimensional simulations of these shots will be presented with an emphasis on comparison with experimental indicators of departure from spherical symmetry (1-D-ness''). The roles of short- and long-wavelength perturbations are considered. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.
1. Associations between variants of FADS genes and omega-3 and omega-6 milk fatty acids of Canadian Holstein cows
PubMed Central
2014-01-01
2. Hepatic microsomal. omega. -oxidation of leukotriene B/sub 4/
SciTech Connect
Mukhtar, H.; Bik, D.P.; Das, M.; Bickers, D.R.
1986-03-01
In this study the authors investigated the metabolism of LTB/sub 4/ by rat hepatic microsomes. /sup 3/H-LTB/sub 4/ (9 ..mu..M) was incubated for 20 min in the presence3 of oxygen, NADPH and liver microsomes (1.5 mg). Incubation was followed by extraction and analysis by HPLC. Metabolite identification was based on cochromatography with reference standards. At least three radioactive peaks were observed; two of which were ..omega..-oxidation products 20-OH-LTB/sub 4/ and 20-COOH-LTB/sub 4/. The rate of formation of 20-OH-LTB/sub 4/ (14.6 nmoles/min/mg protein) was higher than that of 20-COOH-LTB/sub 4/ (2.5 nmoles/min/mg protein). The third radioactive peak remains unidentified. Product formation was negligible with boiled microsomes. LTB/sub 4/ ..omega..-hydroxylase activity required NADPH and oxygen, was linear with respect to incubation time and protein, and was maximal at pH 7.4. Enzyme activity was inhibited (>90%) by carbon monoxide, SKF 525A (1 mM), but was not affected by ..cap alpha..-naphthoflavone. Phenobarbital (PB, 80 mg/kg for 3 days), AROCLOR 1254 (100 mg/kg for 3 days) or 3-methylcholanthrene (40 mg/kg for 3 days) administration to rats resulted in only slight (<20%) or no increase in LTB/sub 4/ ..omega..-hydroxylase activity. However, the formation of the unidentified peak was increased (>100%) by PB treatment. These results suggest that ..omega..-oxidation is the major pathway for biotransformation of LTB/sub 4/ in liver microsomes and that this reaction is mediated by cytochrome P-450.
3. Flight test and evaluation of Omega navigation for general aviation
NASA Technical Reports Server (NTRS)
Hwoschinsky, P. V.
1975-01-01
A seventy hour flight test program was performed to determine the suitability and accuracy of a low cost Omega navigation receiver in a general aviation aircraft. An analysis was made of signal availability in two widely separated geographic areas. Comparison is made of the results of these flights with other navigation systems. Conclusions drawn from the test experience indicate that developmental system improvement is necessary before a competent fail safe or fail soft area navigation system is offered to general aviation.
4. MAGNESIUM ISOTOPE RATIOS IN {omega} CENTAURI RED GIANTS
SciTech Connect
Da Costa, G. S.; Norris, John E.; Yong, David
2013-05-20
We have used the high-resolution observations obtained at the Anglo-Australian Telescope with Ultra-High Resolution Facility (R {approx} 100,000) and at Gemini-S with b-HROS (R {approx} 150,000) to determine magnesium isotope ratios for seven {omega} Cen red giants that cover a range in iron abundance from [Fe/H] = -1.78 to -0.78 dex, and for two red giants in M4 (NGC 6121). The {omega} Cen stars sample both the ''primordial'' (i.e., O-rich, Na- and Al-poor) and the ''extreme'' (O-depleted, Na- and Al-rich) populations in the cluster. The primordial population stars in both {omega} Cen and M4 show ({sup 25}Mg, {sup 26}Mg)/{sup 24}Mg isotopic ratios that are consistent with those found for the primordial population in other globular clusters with similar [Fe/H] values. The isotopic ratios for the {omega} Cen extreme stars are also consistent with those for extreme population stars in other clusters. The results for the extreme population stars studied indicate that the {sup 26}Mg/{sup 24}Mg ratio is highest at intermediate metallicities ([Fe/H] < -1.4 dex), and for the highest [Al/Fe] values. Further, the relative abundance of {sup 26}Mg in the extreme population stars is notably higher than that of {sup 25}Mg, in contrast to model predictions. The {sup 25}Mg/{sup 24}Mg isotopic ratio in fact does not show any obvious dependence on either [Fe/H] or [Al/Fe] nor, intriguingly, any obvious difference between the primordial and extreme population stars.
5. Metathesis process for preparing an alpha, omega-functionalized olefin
DOEpatents
Burdett, Kenneth A.; Mokhtarzadeh, Morteza; Timmers, Francis J.
2010-10-12
A cross-metathesis process for preparing an .alpha.,.omega.-functionalized olefin, such as methyl 9-decenoate, and an .alpha.-olefin having three or more carbon atoms, such as 1-decene. The process involves contacting in a first reaction zone an .alpha.-functionalized internal olefin, such as methyl oleate, and an .alpha.-olefinic monomer having three or more carbon atoms, such as 1-decene, with a first metathesis catalyst to prepare an effluent stream containing the .alpha.,.omega.-functionalized olefin, such as methyl 9-decenoate, an unfunctionalized internal olefin, such as 9-octadecene, unconverted reactant olefins, and optionally, an .alpha.,.omega.-difunctionalized internal olefinic dimer, such as dimethyl 9-octadecen-1,18-dioate; separating said effluent streams; then contacting in a second reaction zone the unfunctionalized internal olefin with ethylene in the presence of a second metathesis catalyst to obtain a second product effluent containing the .alpha.-olefinic monomer having three or more carbon atoms; and cycling a portion of the .alpha.-olefinic monomer stream(s) to the first zone.
6. Neutron Measurements in Small MagLIF Experiments on OMEGA
Glebov, V. Yu.; Barnak, D. H.; Davies, J. R.; Knauer, J. P.; Betti, R.; Regan, S. P.; Sangster, T. C.; Campbell, E. M.
2016-10-01
The Laboratory for Laser Energetics (LLE) is participating in laser-driven magnetized linear inertial fusion (MagLIF) research on the OMEGA Laser System in partnership with Sandia as part of ARPA-E's ALPHA Program. In the current OMEGA setup, a CH cylindrical tube filled with D2 gas is compressed by 40 laser beams, preheated by one of the beams, and an axial magnetic field is applied to limit electron heat loss. Two copper coils provide 10-T magnetic fields. A neutron time-of-flight (nTOF) detector has been designed, fabricated, and calibrated to diagnose primary D-D fusion neutron yield in the range of 1 ×107 to 5 ×109 and ion temperature from 2 to 8 keV. The design details and calibration results of these nTOF detectors will be presented together with neutron measurement results from recent laser-driven MagLIF experiments on OMEGA. The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000568, and the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.
7. rho/sup 0/. omega. production in photon photon interactions
SciTech Connect
Derby, K.A.
1987-08-01
The subject of this dissertation is the production of the rho/sup 0/..omega.. final state in photon photon interactions. The production of the rho/sup 0/..omega.. final state has been of interest primarily because of its similarity to the related process ..gamma gamma.. ..-->.. rho/sup 0/rho/sup 0/. The cross section for rho/sup 0/rho/sup 0/ production demonstrates a peaking near threshold, the mechanism of which has been the subject of considerable speculation. The data sample used for the analysis was obtained using the TPC detector facility at the PEP e/sup +/e/sup -/ storage ring, and corresponds to an integrated e/sup +/e/sup -/ luminosity of 64 pb/sup -1/ at 29 GeV center of mass energy. Our estimate of the rho/sup 0/..omega.. cross section is compared to the predictions of several models which have been used to account for the observed rho/sup 0/rho/sup 0/ cross section. The experimental results are consistent with the predictions of a threshold enhancement model, as well as those of a four quark (qq anti q anti q) resonance model. However, they disagree with the predictions of a t-channel factorization approach.
8. THE DYNAMICS OF THE OUTER PARTS OF {omega} CENTAURI
SciTech Connect
Da Costa, G. S.
2012-05-20
The multi-object fiber-fed spectrograph AAOmega at the Anglo-Australian Telescope has been used to establish and measure accurate ({<=}1 km s{sup -1}) radial velocities for a new sample of members in the outer parts of the stellar system {omega} Centauri. The new sample more than doubles the number of known members with precise velocities that lie between 25' and 45' from the cluster center. Combining this sample with earlier work confirms that the line-of-sight velocity dispersion of {omega} Cen remains approximately constant at {approx}6.5 km s{sup -1} in the outer parts of the cluster, which contain only a small fraction of the total cluster stellar mass. It is argued that the approximately constant velocity dispersion in the outer regions is most likely a consequence of external influences, such as the tidal shock heating that occurs each time {omega} Cen crosses the Galactic plane. There is therefore no requirement to invoke dark matter or non-standard gravitational theories.
9. Omega from the anisotropy of the redshift correlation function
NASA Technical Reports Server (NTRS)
Hamilton, A. J. S.
1993-01-01
Peculiar velocities distort the correlation function of galaxies observed in redshift space. In the large scale, linear regime, the distortion takes a characteristic quadrupole plus hexadecapole form, with the amplitude of the distortion depending on the cosmological density parameter omega. Preliminary measurements are reported here of the harmonics of the correlation function in the CfA, SSRS, and IRAS 2 Jansky redshift surveys. The observed behavior of the harmonics agrees qualitatively with the predictions of linear theory on large scales in every survey. However, real anisotropy in the galaxy distribution induces large fluctuations in samples which do not yet probe a sufficiently fair volume of the Universe. In the CfA 14.5 sample in particular, the Great Wall induces a large negative quadrupole, which taken at face value implies an unrealistically large omega 20. The IRAS 2 Jy survey, which covers a substantially larger volume than the optical surveys and is less affected by fingers-of-god, yields a more reliable and believable value, omega = 0.5 sup +.5 sub -.25.
10. A New Theory of Mix in Omega Capsule Implosions
Knoll, Dana; Chacon, Luis; Rauenzahn, Rick; Simakov, Andrei; Taitano, William; Welser-Sherrill, Leslie
2014-10-01
We put forth a new mix model that relies on the development of a charge-separation electrostatic double-layer at the fuel-pusher interface early in the implosion of an Omega plastic ablator capsule. The model predicts a sizable pusher mix (several atom %) into the fuel. The expected magnitude of the double-layer field is consistent with recent radial electric field measurements in Omega plastic ablator implosions. Our theory relies on two distinct physics mechanisms. First, and prior to shock breakout, the formation of a double layer at the fuel-pusher interface due to fast preheat-driven ionization. The double-layer electric field structure accelerates pusher ions fairly deep into the fuel. Second, after the double-layer mix has occurred, the inward-directed fuel velocity and temperature gradients behind the converging shock transports these pusher ions inward. We first discuss the foundations of this new mix theory. Next, we discuss our interpretation of the radial electric field measurements on Omega implosions. Then we discuss the second mechanism that is responsible for transporting the pusher material, already mixed via the double-layer deep into the fuel, on the shock convergence time scale. Finally we make a connection to recent mix motivated experimental data on. This work conducted under the auspices of the National Nuclear Security Administration of the U.S. Department of Energy at Los Alamos National Laboratory, managed by LANS, LLC under Contract DE-AC52-06NA25396.
11. [Omega-3 fatty acids: the science and the beliefs].
PubMed
Ginsberg, Avidor; Stahl, Ziva; Leventhal, Alex
2009-02-01
The importance of Omega-3 fatty acids intake from dietary supplements or from food sources (mainly fish) has recently become "common knowledge" in the mass media as well as in popular science magazines and advertisements. Therefore, the authors wish to review the updated evidence-based literature regarding the relationship between Omega-3 fatty acid intake and morbidity and its preventative effects in cardiovascular, bone, kidney autoimmune, GI tract diseases, CNS and mental diseases, cancer, diabetes, asthma, ophthalmological health, organ transplants and child and maternal health. Recommendations regarding optimal intake of these fatty acids throughout the lifecycle by various health authorities are cited. The conclusion presents the authors' recommendations for optimal Omega-3 intake in Israel: Recommendations for the general population is to consume at least two weekly portions of fatty fish. For patients with hypertriglyceridemia, dietary supplements containing fish oil, in addition to the above diet, can be considered to be part of the complete medical treatment and follow-up. Limiting fish consumption in risk group populations, such as pregnant women, will also be considered.
12. Deeply virtual and exclusive electroproduction of omega mesons
SciTech Connect
Morand, L; Et. Al.
2005-04-01
The exclusive omega electroproduction off the proton was studied in a large kinematical domain above the nucleon resonance region and for the highest possible photon virtuality (Q{sup 2}) with the 5.75 GeV beam at CEBAF and the CLAS spectrometer. Cross sections were measured up to large values of the four-momentum transfer (-t < 2.7 GeV{sup 2}) to the proton. The contributions of the interference terms sigma{sub TT} and sigma{sub TL} to the cross sections, as well as an analysis of the omega spin density matrix, indicate that helicity is not conserved in this process. The t-channel pi{sup 0} exchange, or more generally the exchange of the associated Regge trajectory, seems to dominate the reaction {gamma}* p {yields} omega p, even for Q{sup 2} as large as 5 GeV{sub 2}. Contributions of handbag diagrams, related to Generalized Parton Distributions in the nucleon, are therefore difficult to extract for this process. Remarkably, the high-t behavior of the cross sections is nearly Q{sup 2}-independent, which may be interpreted as a coupling of the photon to a point-like object in this kinematical limit.
13. Astrometry of the omega Centauri Hubble Space Telescope Calibration Field
NASA Technical Reports Server (NTRS)
Mighell, Kenneth J.
2000-01-01
Astrometry, on the International Celestial Reference Frame (epoch J2000.0), is presented for the Walker (1994, PASP, 106, 828) stars in the omega Centauri (=NGC 5139=C 1323-1472) Hubble Space Telescope Wide Field/Planetary Camera (WF/PC) calibration field of Harris et al. (1993, AJ, 105, 1196). Harris et al. stars were first identified on a WFPC2 observation of the omega Cen HST calibration field. Relative astrometry of the Walker stars in this field was then obtained using Walker's CCD positions and astrometry derived using the STSDAS METRIC task on the positions of the Harris et al. stars on the WFPC2 observation. Finally, the relative astrometry, which was based on the HST Guide Star Catalog, is placed on the International Celestial Reference Frame with astrometry from the USNO-A2.0 catalog. An ASCII text version of the astrometric data of the Walker stars in the omega Cen HST calibration field is available electronically in the online version of the article.
14. Charged Particle Spectroscopy on Omega (Final report)
SciTech Connect
Fletcher, K.; Padalino, S.; Schwartz, B.; Olsen, M.; Wakeman, T.; Petrasso, R.
2001-01-01
Using the 2-MeV Van de Graaf Accelerator at SUNY Geneseo's Nuclear Structure Laboratory, a {sup 3}He-implanted tantalum target was bombarded by 450-keV deuterons to produce high energy protons via the {sup 3}He(d,p){sup 4}He reaction. A 1500-{micro}m surface barrier detector with a 3/16 inch diameter collimator was placed at 8.75 cm from the target and 135{sup o} from the incident beam. A movable arm was setup so that an array of aluminum filters of varying thicknesses could be rotated in front of the detector. A 6-{micro}m mylar filter was also mounted on the movable arm and was used to calibrate the detector as described in the CR-39 experiment report. Eight aluminum filters with thicknesses ranging from 250pm to 1100{micro}m were in turn rotated in front of the collimator and spectra were taken for each. The results are shown on the attached graphs. The theoretical curve for each graph was generated using TRIM The exact energy distribution of the proton beam incident on the target was not known; because no such spectrum could be taken due to the high count rate for elastically scattered deuterons. Instead, it was assumed that the incident beam had a distribution similar to that measured through the 6-{micro}m mylar, namely, an average energy of 13.798 MeV with a standard deviation of 0.027 MeV. A program developed locally was used to generate an input file for TRIM with this distribution. Using this input file, TRIM simulations were run for various thicknesses of Aluminum, from 200 to 1100 {micro}m in 50-{micro}m increments. The solid line on the graph indicates the energies of the transmitted protons. The two dashed lines indicate one standard deviation above and below the average exit energy. TRIM agrees well with the experimental results.
15. Design and Performance of 40 cm Ion Optics
NASA Technical Reports Server (NTRS)
Soulas, George C.
2001-01-01
A 40 cm ion thruster is being developed at the NASA Glenn Research Center to obtain input power and propellant throughput capabilities of 10 kW and 550 kg. respectively. The technical approach here is a continuation of the "derating" technique used for the NSTAR ion thruster. The 40 cm ion thruster presently utilizes the NSTAR ion optics aperture geometry to take advantage of the large database of lifetime and performance data already available. Dome-shaped grids were chosen for the design of the 40 cm ion optics because this design is naturally suited for large-area ion optics. Ion extraction capabilities and electron backstreaming limits for the 40 cm ion optics were estimated by utilizing NSTAR 30 cm ion optics data. A preliminary service life assessment showed that the propellant throughput goal of 550 kg of xenon may be possible with molybdenum 40 cm ion optics. One 40 cm ion optics' set has been successfully fabricated to date. Additional ion optics' sets are presently being fabricated. Preliminary performance tests were conducted on a laboratory model 40 cm ion thruster.
16. Photofraction of a 5 cm x 2 cm BGO scintillator. [bismuth germanate crystal for use in cosmic gamma ray detector
NASA Technical Reports Server (NTRS)
Dunphy, P. P.; Forrest, D. J.
1985-01-01
The photofraction of a 5.1 cm x 2.0 cm bismuth germanate (BGO) scintillator was measured over a gamma-ray energy range of 0.2 to 6.1 MeV. Several methods, used to minimize the effect of room scattering on the measurement, are discussed. These include a gamma-gamma coincidence technique, a beta-gamma coincidence technique, and the use of sources calibrated with a standard 7.6 cm x 7.6 cm sodium iodide scintillator.
17. Effects of proton irradiation and temperature on 1 ohm-cm and 10 ohm-cm silicon solar cells
NASA Technical Reports Server (NTRS)
Nicoletta, C. A.
1973-01-01
The 1 ohm-cm and 10 ohm-cm silicon solar cells were exposed to 1.0 MeV protons at a fixed flux of 10 to the 9th power P/sq cm-sec and fluences of 10 to the 10th power, 10 to the 11th power, 10 to the 12th power and 3 X 10 to the 12th power P/sq cm. I-V curves of the cells were made at room temperature, 65 C and 165 C after each irradiation. A value of 139.5 mw/sq cm was taken as AMO incident energy rate per unit area. Degradation occurred for both uncovered 1 ohm-cm and 10 ohm-cm cells. Efficiencies are generally higher than those of comparable U.S. cells tested earlier. Damage (loss in maximum power efficiency) with proton fluence is somewhat higher for 10 ohm-cm cells, measured at the three temperatures, for fluences above 2 X 10 to the 11th power P/sq cm. Cell efficiency, as expected, changes drastically with temperature.
18. Fast neutron induced fission cross sections of {sup 242m}Am, {sup 245}Cm, {sup 247}Cm
SciTech Connect
Fursov, B.I.; Samylin, B.F.; Smirenkin, G.N.; Polynov, V.N.
1994-12-31
The experimental data on {sup 242m}Am, {sup 245}Cm and {sup 247}Cm fission cross sections in the 0.13-7.2 Mev neutron energy range are presented. The measurements were made at Van-de-Graaf accelerators with monoenergetic neutron sources. The total data errors are 3.8% for {sup 242m}Am, 3.5% for {sup 245}Cm and 4.5% for {sup 247}Cm. The results given in this paper are preliminary ones.
19. Hydrodynamic simulations of long-scale-length two-plasmon-decay experiments at the Omega Laser Facility
Hu, S. X.; Michel, D. T.; Edgell, D. H.; Froula, D. H.; Follett, R. K.; Goncharov, V. N.; Myatt, J. F.; Skupsky, S.; Yaakobi, B.
2013-03-01
Direct-drive-ignition designs with plastic CH ablators create plasmas of long density scale lengths (Ln ≥ 500 μm) at the quarter-critical density (Nqc) region of the driving laser. The two-plasmon-decay (TPD) instability can exceed its threshold in such long-scale-length plasmas (LSPs). To investigate the scaling of TPD-induced hot electrons to laser intensity and plasma conditions, a series of planar experiments have been conducted at the Omega Laser Facility with 2-ns square pulses at the maximum laser energies available on OMEGA and OMEGA EP. Radiation-hydrodynamic simulations have been performed for these LSP experiments using the two-dimensional hydrocode draco. The simulated hydrodynamic evolution of such long-scale-length plasmas has been validated with the time-resolved full-aperture backscattering and Thomson-scattering measurements. draco simulations for CH ablator indicate that (1) ignition-relevant long-scale-length plasmas of Ln approaching ˜400 μm have been created; (2) the density scale length at Nqc scales as Ln(μm)≃(RDPP×I1/4/2); and (3) the electron temperature Te at Nqc scales as Te(keV)≃0.95×√I , with the incident intensity (I) measured in 1014 W/cm2 for plasmas created on both OMEGA and OMEGA EP configurations with different-sized (RDPP) distributed phase plates. These intensity scalings are in good agreement with the self-similar model predictions. The measured conversion fraction of laser energy into hot electrons fhot is found to have a similar behavior for both configurations: a rapid growth [fhot≃fc×(Gc/4)6 for Gc < 4] followed by a saturation of the form, fhot≃fc×(Gc/4)1.2 for Gc ≥ 4, with the common wave gain is defined as Gc=3 × 10-2×IqcLnλ0/Te, where the laser intensity contributing to common-wave gain Iqc, Ln, Te at Nqc, and the laser wavelength λ0 are, respectively, measured in [1014 W/cm2], [μm], [keV], and [μm]. The saturation level fc is observed to be fc ≃ 10-2 at around Gc ≃ 4. The hot
20. Hydrodynamic simulations of long-scale-length two-plasmon-decay experiments at the Omega Laser Facility
SciTech Connect
Hu, S. X.; Michel, D. T.; Edgell, D. H.; Froula, D. H.; Follett, R. K.; Goncharov, V. N.; Myatt, J. F.; Skupsky, S.; Yaakobi, B.
2013-03-15
Direct-drive-ignition designs with plastic CH ablators create plasmas of long density scale lengths (L{sub n} {>=} 500 {mu}m) at the quarter-critical density (N{sub qc}) region of the driving laser. The two-plasmon-decay (TPD) instability can exceed its threshold in such long-scale-length plasmas (LSPs). To investigate the scaling of TPD-induced hot electrons to laser intensity and plasma conditions, a series of planar experiments have been conducted at the Omega Laser Facility with 2-ns square pulses at the maximum laser energies available on OMEGA and OMEGA EP. Radiation-hydrodynamic simulations have been performed for these LSP experiments using the two-dimensional hydrocode draco. The simulated hydrodynamic evolution of such long-scale-length plasmas has been validated with the time-resolved full-aperture backscattering and Thomson-scattering measurements. draco simulations for CH ablator indicate that (1) ignition-relevant long-scale-length plasmas of L{sub n} approaching {approx}400 {mu}m have been created; (2) the density scale length at N{sub qc} scales as L{sub n}({mu}m) Asymptotically-Equal-To (R{sub DPP} Multiplication-Sign I{sup 1/4}/2); and (3) the electron temperature T{sub e} at N{sub qc} scales as T{sub e}(keV) Asymptotically-Equal-To 0.95 Multiplication-Sign {radical}(I), with the incident intensity (I) measured in 10{sup 14} W/cm{sup 2} for plasmas created on both OMEGA and OMEGA EP configurations with different-sized (R{sub DPP}) distributed phase plates. These intensity scalings are in good agreement with the self-similar model predictions. The measured conversion fraction of laser energy into hot electrons f{sub hot} is found to have a similar behavior for both configurations: a rapid growth [f{sub hot} Asymptotically-Equal-To f{sub c} Multiplication-Sign (G{sub c}/4){sup 6} for G{sub c} < 4] followed by a saturation of the form, f{sub hot} Asymptotically-Equal-To f{sub c} Multiplication-Sign (G{sub c}/4){sup 1.2} for G{sub c} {>=} 4, with the
1. A combination of omega-3 fatty acids, folic acid and B-group vitamins is superior at lowering homocysteine than omega-3 alone: A meta-analysis.
PubMed
Dawson, Samantha Loren; Bowe, Steven John; Crowe, Timothy Charles
2016-06-01
The aim of the study was to assess whether omega-3 polyunsaturated fatty acid supplementation alone or in combination with folic acid and B-group vitamins is effective in lowering homocysteine. The Medline Ovid, Embase and Cochrane databases were searched for randomized-controlled trial studies that intervened with omega-3 supplementation (with or without folic acid) and measured changes in homocysteine concentration. Studies were pooled using a random effects model for meta-analysis. Three different models were analyzed: all trials combined, omega-3 polyunsaturated fatty acid trials, and omega-3 polyunsaturated fatty acids with folic acid and B-group vitamin trials. Nineteen studies were included, consisting of 3267 participants completing 21 trials. Studies were heterogeneous; varying by dose, duration and participant health conditions. Across all trials, omega-3 supplementation was effective in lowering homocysteine by an average of 1.18μmol/L (95%CI: (-1.89, -0.48), P=.001). The average homocysteine-lowering effect was greater when omega-3 supplementation was combined with folic acid and B-group vitamins (-1.37μmol/L, 95%CI: (-2.38, -0.36), P<.01) compared to omega-3 supplementation alone (-1.09μmol/L 95%CI: (-2.04, -0.13), P=.03). Omega-3 polyunsaturated fatty acid supplementation was associated with a modest reduction in homocysteine. For the purposes of reducing homocysteine, a combination of omega-3s (0.2-6g/day), folic acid (150 - 2500μg/day) and vitamins B6 and B12 may be more effective than omega-3 supplementation alone.
2. Theory of laser enhancement and suppression of cold reactions: the fermion-boson 6Li+7Li2<-->(variant Planck's over 2pi omega0) 6Li7Li+7Li radiative collision.
PubMed
Li, Xuan; Parker, Gregory A; Brumer, Paul; Thanopulos, Ioannis; Shapiro, Moshe
2008-03-28
We present a nonperturbative time-dependent quantum mechanical theory of the laser catalysis and control of a bifurcating A+BC<-->(variant Planck's over 2pi omega(0))ABC*(v)<-->(variant Planck's over 2pi omega(0) )AB+C reaction, with ABC*(v) denoting an intermediate, electronically excited, complex of ABC in the vth vibrational state. We apply this theory to the low collision energy fermion-boson light-induced exchange reaction, (6)Li((2)S)+(7)Li(2)((3)Sigma(u)(+))<-->(variant Planck's over 2pi omega(0))((6)Li(7)Li(7)Li)*<-->(variant Planck's over 2pi omega(0))(6)Li(7)Li((3)Sigma(+))+(7)Li((2)S). We show that at very low collision energies and energetically narrow (approximately 0.01 cm(-1)) initial reactant wave packets, it is possible to tune the yield of the exchange reaction from 0 to near-unity (yield >or=99%) values. Controllability is somewhat reduced at collisions involving energetically wider (approximately 1 cm(-1)) initial reactant wave packets. At these energetic bandwidths, the radiative reactive control, although still impressive, is limited to the 0%-76% reactive-probabilities range.
3. Fourier transform IR spectroscopic study of hydration-induced structure changes in the solid state of omega-gliadins.
PubMed Central
Wellner, N; Belton, P S; Tatham, A S
1996-01-01
The hydration of omega-gliadins and party deamidated and esterified omega-gliadins has been studied by Fourier transform IR spectroscopy. The secondary structure of the fully hydrated proteins was a mixture of beta-turns and extended chains, with a small amount of intermolecular beta-sheets. The absorption of the glutamine side chain amide groups contributed considerably to the amide I band with two well-defined peaks at 1658 and 1610 cm-1. the amide I band of the dry native sample could not be resolved into single component bands. There the backbone structure seemed to be distorted by extensive hydrogen bonding involving glutamine side chains. With increasing water content, these hydrogen bonds were broken successively by water molecules, resulting in an increase in extended, hydrated structures, which gave rise to the formation of intermolecular beta-sheet structures. Above 35% (w/w) water the beta-sheet content fell sharply and was replaced by extensively hydrated extended structures. An amide I band similar to dissolved poly-L-proline proved that parts of the polymer were in a solution-like state. The replacement of many glutamine side chains in the esterified protein produced more resolved secondary structures even in the dry sample. The beta-sheet content of the dry sample was higher than in the native omega-gliadins, but hydration generally caused very similar changes. At all hydration levels the spectra indicated a more ordered structure than in the native sample. Overall, the modification caused changes that go beyond the simple presence or absence of glutamine bands. PMID:8920975
4. Fourier transform IR spectroscopic study of hydration-induced structure changes in the solid state of omega-gliadins.
PubMed
Wellner, N; Belton, P S; Tatham, A S
1996-11-01
The hydration of omega-gliadins and party deamidated and esterified omega-gliadins has been studied by Fourier transform IR spectroscopy. The secondary structure of the fully hydrated proteins was a mixture of beta-turns and extended chains, with a small amount of intermolecular beta-sheets. The absorption of the glutamine side chain amide groups contributed considerably to the amide I band with two well-defined peaks at 1658 and 1610 cm-1. the amide I band of the dry native sample could not be resolved into single component bands. There the backbone structure seemed to be distorted by extensive hydrogen bonding involving glutamine side chains. With increasing water content, these hydrogen bonds were broken successively by water molecules, resulting in an increase in extended, hydrated structures, which gave rise to the formation of intermolecular beta-sheet structures. Above 35% (w/w) water the beta-sheet content fell sharply and was replaced by extensively hydrated extended structures. An amide I band similar to dissolved poly-L-proline proved that parts of the polymer were in a solution-like state. The replacement of many glutamine side chains in the esterified protein produced more resolved secondary structures even in the dry sample. The beta-sheet content of the dry sample was higher than in the native omega-gliadins, but hydration generally caused very similar changes. At all hydration levels the spectra indicated a more ordered structure than in the native sample. Overall, the modification caused changes that go beyond the simple presence or absence of glutamine bands.
5. The omega-6/omega-3 ratio and dementia or cognitive decline: a systematic review on human studies and biological evidence.
PubMed
Loef, Martin; Walach, Harald
2013-01-01
It has been suggested that the intake of certain fatty acids may influence the risk of dementia. However, current reviews have focused only on the therapeutic effects of omega-3 fatty acids, mostly as supplements. To date, the evidence for the relevance of the omega-6/omega-3 ratio has been neglected. Therefore, we searched the databases Alois, Medline, Biosis, Embase, Cochrane Central Register of Controlled Trials, and The Cochrane Database of Systematic Reviews for "essential fatty acids" and "dementia" and aimed to conduct a comprehensive review across study types. All studies that reported on the association between the n-6/n-3 ratio and dementia or cognitive decline were selected. In the 13 animal studies we examined, the dietary n-6/n-3 ratio was shown to affect brain composition, Alzheimer's disease pathology, and behavior. Our review of the 14 studies in humans that fulfilled the selection criteria (7 prospective studies, 3 cross-sectional studies, 1 controlled trial, 3 case-control studies) provided evidence, albeit limited, supporting an association between the n-6/n-3 ratio, cognitive decline, and incidence of dementia. This review supports growing evidence of a positive association between the dietary n-6/n-3 ratio and the risk of Alzheimer's disease.
6. 40 CFR 721.10092 - Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-[[1-[(2-propen-1-yloxy)methyl]undecyl]oxy...
Code of Federal Regulations, 2010 CFR
2010-07-01
....-sulfo-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega...-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.- tridecyl...) The chemical substance identified as poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-...
7. 40 CFR 721.10092 - Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-[[1-[(2-propen-1-yloxy)methyl]undecyl]oxy...
Code of Federal Regulations, 2012 CFR
2012-07-01
....-sulfo-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega...-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.- tridecyl...) The chemical substance identified as poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-...
8. 40 CFR 721.10092 - Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-[[1-[(2-propen-1-yloxy)methyl]undecyl]oxy...
Code of Federal Regulations, 2011 CFR
2011-07-01
....-sulfo-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega...-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.- tridecyl...) The chemical substance identified as poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-...
9. 40 CFR 721.10092 - Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-[[1-[(2-propen-1-yloxy)methyl]undecyl]oxy...
Code of Federal Regulations, 2014 CFR
2014-07-01
....-sulfo-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega...-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.- tridecyl...) The chemical substance identified as poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-...
10. 40 CFR 721.10092 - Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-[[1-[(2-propen-1-yloxy)methyl]undecyl]oxy...
Code of Federal Regulations, 2013 CFR
2013-07-01
....-sulfo-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega...-.omega.- undecyl]oxy]-, ammonium salt (1:1); Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.- tridecyl...) The chemical substance identified as poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-...
11. Omega-3 supplementation in autism spectrum disorders: A still open question?
PubMed Central
Posar, Annio; Visconti, Paola
2016-01-01
One of the most commonly used complementary and alternative practices in children with autism spectrum disorder (ASD) is the supplementation of omega-3. We describe the case of a child with ASD who seemed to respond to omega-3 supplementation in a relevant and lasting manner. So far, based on the results of randomized clinical trials, evidence-based medicine negates the effectiveness of omega-3 in ASD children. Nevertheless, considering anecdotal experiences, including that of our patient, and nonrandomized trials, the presence of a subgroup of ASD patients who are really responders to omega-3 cannot be excluded. These responders might not appear when evaluating the omega-3 effects in a sample taken as a whole. Studies that check for the possible presence of this subgroup of ASD individuals responders to omega-3 are necessary. PMID:27857792
12. The hot bands of silane between 2120 and 2270 cm -1
Terki-Hassaïne, M.; Pierre, G.; Boudon, V.; Aït Hamadouche, G.; Guelachvili, G.
2005-04-01
The infrared spectrum of the SiH 4 molecule has been recorded between 2040 and 2320 cm -1 using the high-resolution Fourier interferometer of the Laboratoire de Photophysique Moléculaire ( Orsay, France). The resolution was 5.4 × 10 -3 cm -1. In this region, many lines were previously analyzed and assigned to the ν1/ ν3 stretching dyad of 28SiH 4, 29SiH 4, and 30SiH 4 molecules [J. Mol. Spectrosc. 143 (1990) 35]. However, several lines in the spectrum were not assigned. The results obtained in our previous study [J. Mol. Spectrosc. 197 (1999) 307] of the infrared spectrum of 28SiH 4, in the bending-stretching tetrad region at 3100 cm -1, enabled us to assign 204 of the observed transitions to hot bands (the ν1 + ν2/ ν1 + ν4/ ν2 + ν3/ ν3 + ν4 bending-stretching tetrad minus the ν2/ ν4 bending dyad). These transitions were used to refine the set of the Hamiltonian parameters of the bending-stretching tetrad. The analysis is performed using the tensorial formalism developed in Dijon for tetrahedral molecules and implemented in the STDS software ( http://www.u-bourgogne.fr/LPUB/shTDS.html).
13. OMEGA System Performance Assessment and Coverage Evaluation (PACE) Workstation Design and Implementation. Volume 2
DTIC Science & Technology
1991-02-15
contract number * * DI2~ 3 -89-C-20008, Task Order 90-0001, Task No. 5834, for * * the Omega Navigation System Center (ONSN), Alexardria, VA. * * IJR * * Ts...CG-ONSCEN-02.2- 1’ OMEGA SYSTEM PERFORMANCE ASSESSMENT AND COVERAGE EVALUATION (PACE) WORKSTATION DESIGN AND IMPLEMENTATION AD- A239 7 24 George R...Springfield, Virginia 22161 Prepared for: U.S. DEPARTMENT OF TRANSPORTATION UNITED STATES COAST GUARD OMEGA Navigation System Center Alexandria, Virginia
14. OMEGA Japan Antenna System: Modification and Validation Tests. Volume 2. Data Sheets.
DTIC Science & Technology
1979-10-15
INFORMATION Electronic measurements were performed on the OMEGA Japan Antenna System during the months of October and November 1 978. The work was...TITLE (end Subtitle) S. TYPE OF REPORT & PERIOD COVERED OMEGA JAPAN ANTENNA SYSTEM: MODIFICATION AND Final VALIDATION TESTS (Two Volumes) S Volume2...Electronic measurements were performed on the OMEGA Japan antenna system during October- November 1978. The work was performed by Megatek
15. Omega from the anisotropy of the redshift correlation function in the IRAS 2 Jansky survey
NASA Technical Reports Server (NTRS)
Hamilton, A. J. S.
1993-01-01
Peculiar velocities distort the correlation function of galaxies in redshift space. In the linear regime, the distortion has a characteristic quadrupole plus hexadecapole form, with amplitude depending on the cosmological density parameter Omega. I report here measurements of the anisotropy of the correlation function in the IRAS 2 Jy redshift survey. The inferred value of Omega is Omega = 0.5 + 0.5 or - 0.25.
16. Eight-cm mercury ion thruster system technology
NASA Technical Reports Server (NTRS)
1974-01-01
The technology status of 8 cm diameter electron bombardment ion thrusters is presented. Much of the technology resulting from the 5 cm diameter thruster has been adapted and improved upon to increase the reliability, durability, and efficiency of the 8 cm thruster. Technology discussed includes: dependence of neutralizer tip erosion upon neutralizer flow rate; impregnated and rolled-foil insert cathode performance and life testing; neutralizer position studies; thruster ion beam profile measurements; high voltage pulse ignition; high utilization ion machined accelerator grids; deposition internal and external to the thruster; thruster vectoring systems; thruster cycling life testing and thruster system weights for typical mission applications.
17. Ion accelerator systems for high power 30 cm thruster operation
NASA Technical Reports Server (NTRS)
Aston, G.
1982-01-01
Two and three-grid accelerator systems for high power ion thruster operation were investigated. Two-grid translation tests show that over compensation of the 30 cm thruster SHAG grid set spacing the 30 cm thruster radial plasma density variation and by incorporating grid compensation only sufficient to maintain grid hole axial alignment, it is shown that beam current gains as large as 50% can be realized. Three-grid translation tests performed with a simulated 30 cm thruster discharge chamber show that substantial beamlet steering can be reliably affected by decelerator grid translation only, at net-to-total voltage ratios as low as 0.05.
18. Alteration and formation of rims on the CM parent body
Browning, Lauren B.; McSween, Harry Y., Jr.; Zolensky, Michael
1994-03-01
All types of coarse-grained components in CM chondrites are surrounded by fine-grained dust coatings, but the origin of these rims is not yet clear. Although a strictly nebular origin seems likely for rims in the relatively unaltered type 3 chondrites, the rims in CM chondrites are dominated by secondary alteration phases. It has been argued that either the coarse-grained cores accreted altered rim materials while still in the nebula or that alteration of primary rim phases occurred on the CM parent body. To constrain the origin of alteration phases in rim material, we have analyzed the textures and mineral associations from 10 CM chondritic falls by optical and scanning electron microscopy. Our results indicate that the secondary phases in CM chondritic rims were produced by parent body fluid-rock interactions which redefined some primary rim textures and may have produced, in some cases, both coarse-grained components and the rims that surround them. Textural features demonstrate the interactive exchange of alteration fluids between rims, matrix, and chondrules on the CM parent body. For example, most matrix-rim contacts are gradational, suggesting the synchronous alteration of both components. Several observations suggest the possibility of in situ rim production. For example, tochilinite and phyllosilicates commonly form rims around matrix carbonates, which are generally believed to have precipitated from alteration fluids on the CM parent body. This suggests that the rims surrounding matrix carbonates may also have been produced by alteration processes. Partially replaced chondrule olivines bear a striking resemblance to many rimmed olivines in the matrix which suggests, by analogy, that site-specific precipitation of S-bearing phases may also be responsible for the occurrence of many tochilinite-rich rims around isolated matrix olivines. Non-silicate rims precipitate around olivines of any composition, but the process is most effective for fayalitic olivines
19. Reduced cardiac remodelling and prevention of glutathione deficiency after omega-3 supplementation in chronic heart failure.
PubMed
Fang, Yuehua; Favre, Julie; Vercauteren, Magalie; Laillet, Brigitte; Remy-Jouet, Isabelle; Skiba, Mohamed; Lallemand, Françoise; Dehaudt, Cathy; Monteil, Christelle; Thuillez, Christian; Mulder, Paul
2011-06-01
n-3 polyunsaturated fatty acids (omega-3) supplementation is associated with reduced cardiovascular mortality and post-infarction death. However, the impact of omega-3 supplementation in congestive heart failure (CHF) is still unknown. This study assesses the effects of omega-3 supplementation on left ventricular (LV) function and remodelling. We assessed, in rats with CHF induced by left coronary ligation, the effects of a 1-week and a 12-week supplementation with omega-3 (450 mg/kg per day) on LV hemodynamics, function and structure. Chronic omega-3 reduces total peripheral resistance due to an increase in cardiac output without modification of arterial pressure. Only chronic omega-3 reduces LV end-diastolic pressure and LV relaxation constant. Moreover, chronic omega-3 decreases LV systolic and diastolic diameters, LV weight and collagen density. Acute and chronic omega-3 increase LV γ-glutamyl-cysteine synthetase and oppose glutathione deficiency resulting in a reduction of myocardial oxidized glutathione. In experimental CHF, long-term omega-3 supplementation improves LV hemodynamics and function and prevents LV remodelling and glutathione deficiency. The latter might be one of the mechanisms involved, but whether other mechanism, independent of myocardial redox 'status', such as reduced inflammation, are implicated remains to be confirmed.
20. Implementation of an experimental program to investigate the performance characteristics of OMEGA navigation
NASA Technical Reports Server (NTRS)
Baxa, E. G., Jr.
1974-01-01
A theoretical formulation of differential and composite OMEGA error is presented to establish hypotheses about the functional relationships between various parameters and OMEGA navigational errors. Computer software developed to provide for extensive statistical analysis of the phase data is described. Results from the regression analysis used to conduct parameter sensitivity studies on differential OMEGA error tend to validate the theoretically based hypothesis concerning the relationship between uncorrected differential OMEGA error and receiver separation range and azimuth. Limited results of measurement of receiver repeatability error and line of position measurement error are also presented.
1. Antibiotic resistance gene cassettes derived from the omega interposon for use in E. coli and Streptomyces.
PubMed
Blondelet-Rouault, M H; Weiser, J; Lebrihi, A; Branny, P; Pernodet, J L
1997-05-06
Three antibiotic resistance gene cassettes, derived from the omega interposon (Prentki and Krisch (1984) Gene 29, 303-313) were constructed. These cassettes carry different antibiotic resistance genes, conferring resistance to geneticin, hygromycin or viomycin, flanked by short inverted repeats containing transcription and translation termination signals and synthetic polylinkers. These cassettes were designated omega aac, omega hyg and omega vph. Resistance phenotypes conferred by these constructions are selectable in E. coli and Streptomyces. These cassettes can be used for insertional mutagenesis or for vector construction.
2. Potential Benefits of Omega-3 Fatty Acids in Non-Melanoma Skin Cancer.
PubMed
Black, Homer S; Rhodes, Lesley E
2016-02-04
Considerable circumstantial evidence has accrued from both experimental animal and human clinical studies that support a role for omega-3 fatty acids (FA) in the prevention of non-melanoma skin cancer (NMSC). Direct evidence from animal studies has shown that omega-3 FA inhibit ultraviolet radiation (UVR) induced carcinogenic expression. In contrast, increasing levels of dietary omega-6 FA increase UVR carcinogenic expression, with respect to a shorter tumor latent period and increased tumor multiplicity. Both omega-6 and omega-3 FA are essential FA, necessary for normal growth and maintenance of health and although these two classes of FA exhibit only minor structural differences, these differences cause them to act significantly differently in the body. Omega-6 and omega-3 FA, metabolized through the lipoxygenase (LOX) and cyclooxygenase (COX) pathways, lead to differential metabolites that are influential in inflammatory and immune responses involved in carcinogenesis. Clinical studies have shown that omega-3 FA ingestion protects against UVR-induced genotoxicity, raises the UVR-mediated erythema threshold, reduces the level of pro-inflammatory and immunosuppressive prostaglandin E2 (PGE₂) in UVR-irradiated human skin, and appears to protect human skin from UVR-induced immune-suppression. Thus, there is considerable evidence that omega-3 FA supplementation might be beneficial in reducing the occurrence of NMSC, especially in those individuals who are at highest risk.
3. Various Effects of Omega 3 and Omega 3 Plus Vitamin E Supplementations on Serum Glucose Level and Insulin Resistance in Patients with Coronary Artery Disease
PubMed Central
SABOORI, Somayeh; DJALALI, Mahmoud; YOUSEFI RAD, Esmaeil; Nematipour, Ebrahim; SABOOR-YARAGHI, Ali Akbar; JAVANBAKHT, Mohammad Hassan; ESHRAGHIAN, Mohammad Reza; RAMEZANI, Atena; KOOHDANI, Fariba
2016-01-01
Background: Omega 3 and vitamin E are two critical nutrients which include beneficial effects in coronary artery disease (CAD). The aim of this study was to assess the effects of omega 3 alone supplementation or in combination with vitamin E on serum glucose and lipid levels and insulin resistance in CAD patients. Methods: Participants of this clinical trial included 60 male patients with CAD who selected from Tehran Heart Center in Tehran, Iran in 2014. They received 4 g/day omega 3 plus 400 IU/day vitamin E (OE), 4 g/day omega 3 with vitamin E placebo (OP), or omega 3 and vitamin E placebo (PP) for two months. Serum glucose, lipids and insulin were assessed and HOMA-IR was calculated before and after the trial and effects of these nutrients on the highlighted parameters were compared within the study groups. Results: Serum glucose level increased significantly in OP group (P=0.004), but not in OE group. OE and OP groups showed a significant decrease in fasting serum TG (P=0.020 and P=0.001, respectively). Serum insulin and HOMA-IR decreased significantly in OE group (P=0.044 and P=0.039, respectively) but did not change significantly in OP group. Conclusion: Although, omega 3 supplementation may include adverse effects on serum glucose level, co-administration of omega 3 and vitamin E can beneficially decrease serum insulin and insulin resistance in CAD patients. PMID:28032064
4. Benchmarking and performance analysis of the CM-2. [SIMD computer
NASA Technical Reports Server (NTRS)
Myers, David W.; Adams, George B., II
1988-01-01
A suite of benchmarking routines testing communication, basic arithmetic operations, and selected kernel algorithms written in LISP and PARIS was developed for the CM-2. Experiment runs are automated via a software framework that sequences individual tests, allowing for unattended overnight operation. Multiple measurements are made and treated statistically to generate well-characterized results from the noisy values given by cm:time. The results obtained provide a comparison with similar, but less extensive, testing done on a CM-1. Tests were chosen to aid the algorithmist in constructing fast, efficient, and correct code on the CM-2, as well as gain insight into what performance criteria are needed when evaluating parallel processing machines.
5. The 21-cm Signal from the cosmological epoch of recombination
SciTech Connect
Fialkov, A.; Loeb, A. E-mail: aloeb@cfa.harvard.edu
2013-11-01
The redshifted 21-cm emission by neutral hydrogen offers a unique tool for mapping structure formation in the early universe in three dimensions. Here we provide the first detailed calculation of the 21-cm emission signal during and after the epoch of hydrogen recombination in the redshift range of z ∼ 500–1,100, corresponding to observed wavelengths of 100–230 meters. The 21-cm line deviates from thermal equilibrium with the cosmic microwave background (CMB) due to the excess Lyα radiation from hydrogen and helium recombinations. The resulting 21-cm signal reaches a brightness temperature of a milli-Kelvin, orders of magnitude larger than previously estimated. Its detection by a future lunar or space-based observatory could improve dramatically the statistical constraints on the cosmological initial conditions compared to existing two-dimensional maps of the CMB anisotropies.
6. CM Process Improvement and the International Space Station Program (ISSP)
NASA Technical Reports Server (NTRS)
Stephenson, Ginny
2007-01-01
This viewgraph presentation reviews the Configuration Management (CM) process improvements planned and undertaken for the International Space Station Program (ISSP). It reviews the 2004 findings and recommendations and the progress towards their implementation.
7. Baseline Blood Levels of Omega-3 and Depression Remission: A secondary analysis of data from a placebo-controlled trial of omega-3 supplements
PubMed Central
Carney, Robert M.; Steinmeyer, Brian C.; Freedland, Kenneth E.; Rubin, Eugene H.; Rich, Michael W.; Harris, William S.
2017-01-01
Objective Depression is associated with low red blood cell (RBC) levels of two omega-3 fatty acids (FAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), suggesting that omega-3 supplements might improve depression. However, clinical trials have produced mixed results. The purpose of this secondary analysis of data from a randomized controlled trial was to determine whether baseline blood levels of omega-3, which are known to vary widely among individuals, predict depression outcomes. Methods The percentages of EPA, DHA, and the omega-6 arachidonic acid (AA) were measured in RBCs at baseline and post-treatment in 122 participants with DSM-IV major depression who were randomized between May 2005 and December 2008 to receive either 50 mg/day of sertraline and 930 mg EPA/750 mg DHA/day or sertraline plus placebo. Associations between baseline RBC omega-3 levels and remission of depression (HAM-D≤7) were analyzed by treatment arm. Results Among participants in the omega-3 arm, baseline RBC levels of EPA+DHA (p=0.002) and the EPA+DHA:AA ratio (p=0.003) were significantly higher among those whose depression subsequently remitted compared with those whose depression did not remit. No associations were detected in the sertraline plus placebo arm. Baseline levels of EPA (p=0.03) and the EPA+DHA:AA ratio (p=0.04) moderated the relationship between treatment arm and depression outcomes. Conclusion High pre-treatment RBC levels of EPA and DHA, and a high EPA+DHA:AA ratio, predict favorable depression outcomes in patients receiving omega-3 supplements. Omega-3 supplementation may be an effective treatment for depression, but the requisite dosage and duration of treatment may depend on the patient's baseline level of omega-3. PMID:26930527
8. Risk of Malignancy in Thyroid Nodules 4 cm or Larger
PubMed Central
2017-01-01
Background Several authors have questioned the accuracy of fine-needle aspiration cytology (FNAC) in large nodules. Some surgeons recommend thyroidectomy for nodules ≥4 cm even in the setting of benign FNAC, due to increased risk of malignancy and increased false negative rates in large thyroid nodules. The goal of our study was to evaluate if thyroid nodule size is associated with risk of malignancy, and to evaluate the false negative rate of FNAC for thyroid nodules ≥4 cm in our patient population. Methods This is a retrospective study of 85 patients with 101 thyroid nodules, who underwent thyroidectomy for thyroid nodules measuring ≥4 cm. Results The overall risk of malignancy in nodules ≥4 cm was 9.9%. Nodule size was not associated with risk of malignancy (odds ratio, 1.02) after adjusting for nodule consistency, age, and sex (P=0.6). The false negative rate for FNAC was 0%. Conclusion Nodule size was not associated with risk of malignancy in nodules ≥4 cm in our patient population. FNAC had a false negative rate of 0. Patients with thyroid nodules ≥4 cm and benign cytology should not automatically undergo thyroidectomy. PMID:28181427
9. Thermal properties of the martian surface inferred from OMEGA data
Audouard, J.; Poulet, F.; Vincendon, M.; Bibring, J.; Gondet, B.; Langevin, Y.
2011-12-01
Martian surface temperatures are the results of radiative exchanges between the air and the shallow subsurface. Thermal inertia (TI) and the albedo are key parameters for modulating diurnal temperature variation of surfaces. TI, which represents the resistance to change in temperature of the upper few centimeters of the subsurface throughout the day, is independent of local time, latitude, and season. Thermal infrared spectrometers TES and THEMIS that measured the surface temperature have been frequently used to derive the thermal properties of the martian surface (see e.g. Putzig et al. 2005; Fergason et al. 2006). Global TI derivation techniques usually assume that the thermophysical properties of the soil are vertically uniform (Putzig et al. 2005), while vertical heterogeneities are observed (Putzig and Mellon 2007; Bandfield and Feldman 2008). As the thermal wave penetration depth varies with season, various apparent thermal inertias are derived as a function of season for a given location (Putzig et al. 2005). Surface temperatures (larger than ~200 K) can be derived from the OMEGA/Mars Express hyperspectral observations (Jouglet et al. 2007). Of special interest is the elliptical MEX orbit that makes possible to observe a given surface element at various local time and solar longitude. This allow us to explore different parts of the thermal response of martian soils and can be used to better constrain the properties of the subsurface. We have developed an operational pixel-to-pixel climate modeling interface using the Martian Global Climate Model (Forget et al. 1999), in order to compare the surface temperature measured by OMEGA with the modeled temperature. A systematic comparison data/model covering 4 Martian years will be discussed. A few local scale thermal inertia retrievals will be then presented and compared to previous studies based on TES/MGS and THEMIS/Mars Odyssey data. We will also investigate the thermophysical properties of soils where anomalous
10. GALEX Grism Spectroscopy of the Globular Cluster Omega Centauri
Sweigart, Allen
We propose to obtain GALEX FUV-only grism spectroscopy of the hot stars in omega Centauri, the most massive globular cluster in our Galaxy. Previous UIT imagery of omega Cen showed that it contains about 2000 hot horizontal branch (HB) stars, and we estimate that GALEX spectra can be obtained for about 500 of these stars in the outer regions of the cluster, including about 50 of the hot blue hook'' stars discovered with UIT. The blue hook stars appear to be both hotter (35,000 K) and less luminous in the UIT color-magnitude diagram than predicted by canonical HB models and, indeed, are unexplained by standard evolutionary theory. Brown et al. (2001) have suggested that the blue hook stars are the progeny of stars which mixed their surface hydrogen into their hot He-burning interior during a delayed helium flash subsequent to leaving the red giant branch. This flash-mixing'' results in a hot hydrogen-deficient star with a typical surface abundance of 96% He and 4% C by mass. The GALEX spectral region includes the strong lines of C III 1426, 1578 A, C IV 1550 A, and He II 1640 A which will allow this predicted carbon and helium enrichment to be detected. These observations will therefore provide a crucial test of the Brown et al. flash-mixing hypothesis and will determine if flash mixing represents a new evolutionary channel for populating the hot HB. The GALEX spectra will also address other questions concerning the hot HB in omega Cen including (1) the metallicity distribution of HB stars with 9,000 K < Teff < 11,000 K, (2) the effect of radiative levitation on the UV spectra of stars with Teff > 11,000 K, and (3) the origin of the subluminous HB stars found in the UIT photometry with 15,000K < Teff < 30,000 K.
11. Final Report: Posttest Analysis of Omega II Optical Specimens
SciTech Connect
Newlander, C D; Fisher, J H
2007-01-30
Preliminary posttest analyses have been completed on optical specimens exposed during the Omega II test series conducted on 14 July 2006. The Omega Facility, located at the Laboratory for Laser Energetics (LLE) at the University of Rochester was used to produce X-ray environments through the interaction of intense pulsed laser radiation upon germanium-loaded silica aerogels. The optical specimen testing was supported by GH Systems through experiment design, pre- and post-test analyses, specimen acquisition, and overall technical experience. The test specimens were fabricated and characterized by Surface Optics Corporation (SOC), San Diego, CA and were simple protected gold coatings on silica substrates. Six test specimens were exposed, five filtered with thin beryllium foil filters, and one unfiltered which was exposed directly to the raw environment. The experimental objectives were: (1) demonstrate that tests of optical specimens could be performed at the Omega facility; (2) evaluate the use and survivability of beryllium foil filters as a function of thickness; (3) obtain damage data on optical specimens which ranged from no damage to damage; (4) correlate existing thermal response models with the damage data; (5) evaluate the use of the direct raw environment upon the specimen response and the ability/desirability to conduct sensitive optical specimen tests using the raw environment; and (6) initiate the development of a protocol for performing optical coatings/mirror tests. This report documents the activities performed by GH Systems in evaluating and using the environments provided by LLNL, the PUFFTFT analyses performed using those environments, and the calculated results compared to the observed and measured posttest data.
12. Omegas and Dry Eye: More Knowledge, More Questions.
PubMed
Hom, Milton M; Asbell, Penny; Barry, Brendan
2015-09-01
The omega-3 (ω3) and omega-6 (ω6) essential fatty acid knowledge base has been exploding. In the last 5 years, at least 12 clinical trials on ω3 and ω6 supplementation and dry eye disease (DED) were published in the peer-reviewed literature (2010 to 2015), about double the amount published in the 5 years prior. Although there is increasing scientific evidence that supports the potential use of ω3 and ω6 supplementation for DED, there are limited randomized controlled trials to properly inform evidence-based medicine. Dry eye disease is one of the most common eye conditions that patients seek care for and cannot be disregarded as a trivial condition. The roles of ω3 and ω6 polyunsaturated fatty acids (PUFAs) in the treatment of DED are still not completely understood. There are distinct and sometimes opposite effects of ω3 and ω6 PUFAs, both of which are essential and cannot be synthesized de novo in the body. These fatty acids must be obtained from the diet, which varies widely by region, even within the United States. Omega-3 PUFAs have anti-inflammatory effects; a proper ratio of ω6:ω3 in the diet must be established. Objectively correlating changes in dry eye syndrome with blood levels of ω3 PUFAs has not been done in a large-scale multisite study. Just as Wilder's law of initial value states that "the direction of response of a body function to any agent depends to a large degree on the initial level of that function," the baseline status needs to be taken into account. There is also no consensus on the dose, composition, length of treatment, and so on with ω3 or ω6 PUFAs. Increased quality evidence on the usefulness of over-the-counter supplements is needed to enable eye care providers to confidently outline specific treatment recommendations for using ω3 PUFAs in DED.
13. Rotation and magnetic field in the Be star omega Orionis
Neiner, C.; Hubert, A.-M.; Frémat, Y.; Floquet, M.; Jankov, S.; Preuss, O.; Henrichs, H. F.; Zorec, J.
2003-10-01
omega Ori is a B2IIIe star for which rotational modulation and non-radial pulsations (NRP) have been recently investigated from two independent observational campaigns in 1998 and 1999. Putting the data of these 2 campaigns together, and adding data obtained in 2001, we search for multiperiodicity in the line profile variations and evidence for outbursts. From new spectropolarimetric data obtained at the Télescope Bernard Lyot (TBL, Pic du Midi, France) in 2001 we also measure the Stokes V parameter in the polarised light. We find evidence for the presence of a weak magnetic field in omega Ori sinusoidally varying with a period of 1.29 d. The equivalent widths (EW) of the wind sensitive UV resonance lines also show a variation with the same period, which we identify as the rotational period of the star. We propose an oblique rotator model and derive Bpol =530 +/- 230 G to explain the observations. Moreover, we carry out an abundance analysis and find the star to be N-enriched, a property which is shared with other magnetic stars. We propose omega Ori as the first known classical Be star hosting a magnetic field. Based on observations obtained using the Musicos spectropolarimeter at the Observatoire du Pic du Midi (France), during the MuSiCoS 98 campaign \\citep{neiner}, and by \\cite{balona}. Based on INES data from the International Ultraviolet Explorer (IUE) satellite. Table 7 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/409/275
14. [Omega-3: from cod-liver oil to nutrigenomics].
PubMed
Caramia, G
2008-08-01
The leading role of cod-liver oil on rickets was a relevant factor in the knowledge of this disease. In 1922 the preventive and therapeutic value of cod-liver oil and sunlight against rickets in young infants was confirmed. The seasonal variation in the incidence of rickets, the role of skin pigmentation, of diet and the fact that breast milk was not an adequate source of vitamin D were understood. The discovery of essential fatty acids omega-6 and omega-3 have shown that deficiencies, mainly of omega-3 long chain polyunsaturated fatty acids, result in visual and cognitive impairment and disturbances in mental functions in infants and also in cognitive function in adults, as fatty acids are beneficial to vascular health and may forestall cerebrovascular disease and thus dementia. An adequate ratio of n-6 and n-3 fatty acids may promote a healthier balance of eicosanoids, which would protect membrane function with a nutraceutical function. Dietary lipids not only influence the biophysical state of the cell membranes but, via direct and indirect routes, they also act on multiple pathways including signalling, gene and protein activities, protein modifications and they probably play important role in modulating protein aggregation. Significant advances have been made in understanding the relation between dietary factors and inflammation, which is a central component of many chronic diseases, including coronary artery disease, rheumatoid arthritis, cancer prevention. However, the identification of those who will or will not benefit from dietary intervention strategies remains a major obstacle. Adequate knowledge about how the responses depend on an individual's genetic background (nutrigenetic effects), the cumulative effects of food components on genetic expression profiles through nutrigenomics mechanism, may assist in identifying responders and non-responders. Thus, fish and fish oil consumption might encourage brain development and gene expression to brain
15. Development of omega-3 rich energy bar with flaxseed.
PubMed
Mridula, D; Singh, K K; Barnwal, P
2013-10-01
Energy bar sample were prepared with different levels of flaxseed (0-20%) in addition to cereals and pulses with varying levels of sweeteners (45, 50, and 55%) to deliver a nutritious food to the consumer. The developed bars were evaluated for textural, colour, nutritional quality, sensory attributes and total microbial load. Different levels of flaxseed and sweeteners significantly affected the hue and chroma values of the energy bar. In general the level of flaxseed in energy bar did not affect the hardness but it was decreased with increasing level of sweeteners except in control sample. The total calories obtained from the energy bar showed significant increase with the increasing levels of flaxseed, the maximum (397.95 kcal) being for bars with 20% flaxseed and 45% sweeteners. This energy bar sample also showed the maximum protein (12.41%), crude fat (11.86%), ash (1.65%), iron (3.77 mg/100 g), crude fiber (2.18%) and omega-3 as alpha-linolenic acid (22.50%, fatty acid basis) content. The overall mean sensory score for overall acceptability for samples with 10% flaxseed and 55% sweeteners and 15% flaxseed and 45% sweeteners were at par but the omega-3 and other nutrients in the later sample was higher than the former sample, hence, 15% flaxseed and 45% sweeteners along with other ingredients may be considered for production of acceptable quality omega-3 fatty acid rich energy bar at commercial scale, which also stored well at refrigerated condition.
16. CW-cavity ring down spectroscopy of the ozone molecule in the 6625-6830 cm -1 region
Campargue, A.; Kassi, S.; Romanini, D.; Barbe, A.; De Backer-Barilly, M.-R.; Tyuterev, Vl. G.
2006-11-01
The absorption spectrum of ozone, 16O 3, has been recorded by CW-cavity ring down spectroscopy in the 6625-6830 cm -1 region. The typical sensitivity of these recordings ( αmin ˜ 3 × 10 -10 cm -1) allows observing very weak transitions with intensity down to 2 × 10 -28 cm/molecule. 483 and 299 transitions have been assigned to the 2 ν1 + 3 ν2 + 3 ν3A-type band and to the 2 ν1 + 4 ν2 + 2 ν3B-type band, respectively, which are the highest frequency bands of ozone recorded so far under high resolution. Rovibrational transitions with J and Ka values up to 46 and 12, respectively, could be assigned. Despite well-known difficulties to correctly reproduce the energy levels not far from the dissociation limit, it was possible to determine the parameters of an effective Hamiltonian which includes six vibrational states, four of them being dark states. The line positions analysis led to an rms deviation of 8.5 × 10 -3 cm -1 while the experimental line intensities could be satisfactorily reproduced. Additional experiments in the 5970-6021 cm -1 region allows detecting the (233) ← (010) hot band reaching the same upper state as the preceding cold band. From the effective parameters of the (233) state just determined and those of the (010) level available in the literature, 329 transitions could be assigned and used for a further refinement of the rovibrational parameters of the effective Hamiltonian leading to a value of 7.6 × 10 -3 cm -1 for the global rms deviation. The complete list of the experimentally determined rovibrational energy levels of the (233), (242), and (520) states is given. The determined effective Hamiltonian and transition moment operators allowed calculating a line list (intensity cut off of 10 -28 cm/molecule at 296 K), available as Supplementary material for the 6590-6860 and 5916-6021 cm -1 regions. The integrated band strength values are 1.75 × 10 -24 and 4.78 × 10 -25 cm/molecule at 296 K for the 2 ν1 + 3 ν2 + 3 ν3A-type band and
17. Low omega-6 vs. low omega-6 plus high omega-3 dietary intervention for Chronic Daily Headache: Protocol for a randomized clinical trial
PubMed Central
2011-01-01
Background Targeted analgesic dietary interventions are a promising strategy for alleviating pain and improving quality of life in patients with persistent pain syndromes, such as chronic daily headache (CDH). High intakes of the omega-6 (n-6) polyunsaturated fatty acids (PUFAs), linoleic acid (LA) and arachidonic acid (AA) may promote physical pain by increasing the abundance, and subsequent metabolism, of LA and AA in immune and nervous system tissues. Here we describe methodology for an ongoing randomized clinical trial comparing the metabolic and clinical effects of a low n-6, average n-3 PUFA diet, to the effects of a low n-6 plus high n-3 PUFA diet, in patients with CDH. Our primary aim is to determine if: A) both diets reduce n-6 PUFAs in plasma and erythrocyte lipid pools, compared to baseline; and B) the low n-6 plus high n-3 diet produces a greater decline in n-6 PUFAs, compared to the low n-6 diet alone. Secondary clinical outcomes include headache-specific quality-of-life, and headache frequency and intensity. Methods Adults meeting the International Classification of Headache Disorders criteria for CDH are included. After a 6-week baseline phase, participants are randomized to a low n-6 diet, or a low n-6 plus high n-3 diet, for 12 weeks. Foods meeting nutrient intake targets are provided for 2 meals and 2 snacks per day. A research dietitian provides intensive dietary counseling at 2-week intervals. Web-based intervention materials complement dietitian advice. Blood and clinical outcome data are collected every 4 weeks. Results Subject recruitment and retention has been excellent; 35 of 40 randomized participants completed the 12-week intervention. Preliminary blinded analysis of composite data from the first 20 participants found significant reductions in erythrocyte n-6 LA, AA and %n-6 in HUFA, and increases in n-3 EPA, DHA and the omega-3 index, indicating adherence. Trial Registration ClinicalTrials.gov (NCT01157208) PMID:21496264
18. The omega-3 and retinopathy of prematurity relationship.
PubMed
Malamas, Angelakis; Chranioti, Angeliki; Tsakalidis, Christos; Dimitrakos, Stavros A; Mataftsi, Asimina
2017-01-01
The aim of this article is to examine the effect of omega-3 (ω-3) long-chain polyunsaturated fatty acids (LCPUFAs) intake on retinopathy of prematurity (ROP) by reviewing the experimental and clinical trials conducted on animal models and infants. LCPUFAs demonstrate cytoprotective and cytotherapeutic actions contributing to a number of anti-angiogenic and neuroprotective mechanisms within the retina. Their intake appears to have a beneficial effect on ischemia, oxidative stress, inflammation and cellular signaling mechanisms, influencing retinal cell gene expression and cellular differentiation. ω-3 LCPUFAs may modulate metabolic processes that activate molecules implicated in the pathogenesis of vasoproliferative and neurodegenerative retinal diseases such as ROP.
19. The Central Velocity Distribution Function of Omega Centauri
Seitzer, Patrick
1993-12-01
Precise radial velocities have been obtained for 870 red giant stars within 4 arcminutes of the center of the globular cluster Omega Centauri (NGC\\ 5139) using the ARGUS multiple object echelle spectrometer at CTIO. The resulting distribution of radial velocities is analyzed to derive the line of sight velocity distribution function, and is compared with various models of relaxed star clusters. The truncation of the velocity function is due to the Galactic tidal field, and some hint of the form this truncation takes is available even with this small number of stars. Observations at two epochs are available for most of the stars and are used to constrain the fraction of binary stars.
20. Mini-O, simple Omega receiver hardware for user education
NASA Technical Reports Server (NTRS)
Burhans, R. W.
1976-01-01
A problem with the Omega system is a lack of suitable low cost hardware for the small user community. A collection of do it yourself circuit modules are under development intended for use by educational institutions, small boat owners, aviation enthusiasts, and others who have some skills in fabricating their own electronic equipment. Applications of the hardware to time frequency standards measurements, signal propagation monitoring, and navigation experiments are presented. A family of Mini-O systems have been constructed varying from the simplest RF preamplifiers and narrowband filters front-ends, to sophisticated microcomputer interface adapters.
1. The NIF x-ray spectrometer calibration campaign at Omega.
PubMed
Pérez, F; Kemp, G E; Regan, S P; Barrios, M A; Pino, J; Scott, H; Ayers, S; Chen, H; Emig, J; Colvin, J D; Bedzyk, M; Shoup, M J; Agliata, A; Yaakobi, B; Marshall, F J; Hamilton, R A; Jaquez, J; Farrell, M; Nikroo, A; Fournier, K B
2014-11-01
The calibration campaign of the National Ignition Facility X-ray Spectrometer (NXS) was carried out at the Omega laser facility. Spherically symmetric, laser-driven, millimeter-scale x-ray sources of K-shell and L-shell emission from various mid-Z elements were designed for the 2-18 keV energy range of the NXS. The absolute spectral brightness was measured by two calibrated spectrometers. We compare the measured performance of the target design to radiation hydrodynamics simulations.
2. The mothers, Omega-3 and mental health study
PubMed Central
2011-01-01
Background Major depressive disorder (MDD) during pregnancy and postpartum depression are associated with significant maternal and neonatal morbidity. While antidepressants are readily used in pregnancy, studies have raised concerns regarding neurobehavioral outcomes in exposed infants. Omega-3 fatty acid supplementation, most frequently from fish oil, has emerged as a possible treatment or prevention strategy for MDD in non-pregnant individuals, and may have beneficial effects in pregnant women. Although published observational studies in the psychiatric literature suggest that maternal docosahexaenoic acid (DHA) deficiency may lead to the development of MDD in pregnancy and postpartum, there are more intervention trials suggesting clinical benefit for supplementation with eicosapentaenoic acid (EPA) in MDD. Methods/Design The Mothers, Omega-3 and Mental Health study is a double blind, placebo-controlled, randomized controlled trial to assess whether omega-3 fatty acid supplementation may prevent antenatal and postpartum depressive symptoms among pregnant women at risk for depression. We plan to recruit 126 pregnant women at less than 20 weeks gestation from prenatal clinics at two health systems in Ann Arbor, Michigan and the surrounding communities. We will follow them prospectively over the course of their pregnancies and up to 6 weeks postpartum. Enrolled participants will be randomized to one of three groups: a) EPA-rich fish oil supplement (1060 mg EPA plus 274 mg DHA) b) DHA-rich fish oil supplement (900 mg DHA plus 180 mg EPA; or c) a placebo. The primary outcome for this study is the Beck Depression Inventory (BDI) score at 6 weeks postpartum. We will need to randomize 126 women to have 80% power to detect a 50% reduction in participants' mean BDI scores with EPA or DHA supplementation compared with placebo. We will also gather information on secondary outcome measures which will include: omega-3 fatty acid concentrations in maternal plasma and cord blood
3. The omega-3 and retinopathy of prematurity relationship
PubMed Central
Malamas, Angelakis; Chranioti, Angeliki; Tsakalidis, Christos; Dimitrakos, Stavros A; Mataftsi, Asimina
2017-01-01
The aim of this article is to examine the effect of omega-3 (ω-3) long-chain polyunsaturated fatty acids (LCPUFAs) intake on retinopathy of prematurity (ROP) by reviewing the experimental and clinical trials conducted on animal models and infants. LCPUFAs demonstrate cytoprotective and cytotherapeutic actions contributing to a number of anti-angiogenic and neuroprotective mechanisms within the retina. Their intake appears to have a beneficial effect on ischemia, oxidative stress, inflammation and cellular signaling mechanisms, influencing retinal cell gene expression and cellular differentiation. ω-3 LCPUFAs may modulate metabolic processes that activate molecules implicated in the pathogenesis of vasoproliferative and neurodegenerative retinal diseases such as ROP. PMID:28251092
4. Omega 3 fatty acids for prevention and treatment of cardiovascular disease
PubMed Central
Hooper, Lee; Harrison, Roger A; Summerbell, Carolyn D; Moore, Helen; Worthington, Helen V; Ness, Andrew; Capps, Nigel; Smith, George Davey; Riemersma, Rudolph; Ebrahim, Shah
2014-01-01
Background It has been suggested that omega 3 (W3, n-3 or omega-3) fats from oily fish and plants are beneficial to health. Objectives To assess whether dietary or supplemental omega 3 fatty acids alter total mortality, cardiovascular events or cancers using both RCT and cohort studies. Search methods Five databases including CENTRAL, MEDLINE and EMBASE were searched to February 2002. No language restrictions were applied. Bibliographies were checked and authors contacted. Selection criteria RCTs were included where omega 3 intake or advice was randomly allocated and unconfounded, and study duration was at least six months. Cohorts were included where a cohort was followed up for at least six months and omega 3 intake estimated. Data collection and analysis Studies were assessed for inclusion, data extracted and quality assessed independently in duplicate. Random effects meta-analysis was performed separately for RCT and cohort data. Main results Forty eight randomised controlled trials (36,913 participants) and 41 cohort analyses were included. Pooled trial results did not show a reduction in the risk of total mortality or combined cardiovascular events in those taking additional omega 3 fats (with significant statistical heterogeneity). Sensitivity analysis, retaining only studies at low risk of bias, reduced heterogeneity and again suggested no significant effect of omega 3 fats. Restricting analysis to trials increasing fish-based omega 3 fats, or those increasing short chain omega 3s, did not suggest significant effects on mortality or cardiovascular events in either group. Subgroup analysis by dietary advice or supplementation, baseline risk of CVD or omega 3 dose suggested no clear effects of these factors on primary outcomes. Neither RCTs nor cohorts suggested increased relative risk of cancers with higher omega 3 intake but estimates were imprecise so a clinically important effect could not be excluded. Authors’ conclusions It is not clear that dietary
5. Effects of omega-3 fatty acids on orexigenic and anorexigenic modulators at the onset of anorexia.
PubMed
Ramos, Eduardo J B; Romanova, Irina V; Suzuki, Susumu; Chen, Chung; Ugrumov, Michael V; Sato, Tomoi; Goncalves, Carolina G; Meguid, Michael M
2005-06-07
In cancer anorexia, a decrease in food intake (FI) occurs concomitant with changes in orexigenic peptides such as neuropeptide Y (NPY) and anorexigenic peptides such as alpha-melanocyte-stimulating hormone (alpha-MSH) and anorexigenic neurotransmitter serotonin. omega-3 Fatty acid (omega-3FA) inhibits cytokine synthesis, and delays tumor appearance, tumor growth, and onset of anorexia in tumor-bearing rats. We hypothesize that, in cancer anorexia, omega-3FA is associated with quantitative reversal of hypothalamic NPY, alpha-MSH, and serotonin receptor (5-HT(1B)-receptor) enhancing FI. Fischer rats were divided into: MCA tumor bearing fed chow (TB-Chow) or omega-3FA diet (TB-omega-3FA) and controls: non-tumor bearing fed chow (NTB-Chow) or omega-3FA diet (NTB-omega-3FA). Rats were euthanized at anorexia and brains were removed for hypothalamic immunohistochemical study, using NPY, alpha-MSH, and 5-HT(1B)-receptor-specific antibodies and slides assessed by image analysis. Immunostaining specificity was controlled by omission of primary or secondary antibodies and pre-absorption test. At anorexia, FI decreased (P < 0.05) in TB-Chow but did not change in TB-omega-3FA rats. In TB-omega-3FA vs. TB-Chow, NPY immunoreactivity increased 38% in arcuate nucleus (ARC; P < 0.05), and 50% in magnocellular paraventricular nucleus (mPVN; P < 0.05). alpha-MSH decreased 64% in ARC and 29% in mPVN (P < 0.05). 5-HT(1B)-receptor immunoreactivity decreased 13% only in supraoptic nucleus (P < 0.05). No immunoreactivity was found in the control sections. omega-3FA modified hypothalamic peptides and 5-HT-(1B)-receptor immunoreactivity at anorexia, concomitant with an increase in FI, were probably mediated by omega-3FA inhibition of tumor-induced cytokines.
6. The omega-atracotoxins: selective blockers of insect M-LVA and HVA calcium channels.
PubMed
Chong, Youmie; Hayes, Jessica L; Sollod, Brianna; Wen, Suping; Wilson, David T; Hains, Peter G; Hodgson, Wayne C; Broady, Kevin W; King, Glenn F; Nicholson, Graham M
2007-08-15
The omega-atracotoxins (omega-ACTX) are a family of arthropod-selective peptide neurotoxins from Australian funnel-web spider venoms (Hexathelidae: Atracinae) that are candidates for development as biopesticides. We isolated a 37-residue insect-selective neurotoxin, omega-ACTX-Ar1a, from the venom of the Sydney funnel-web spider Atrax robustus, with high homology to several previously characterized members of the omega-ACTX-1 family. The peptide induced potent excitatory symptoms, followed by flaccid paralysis leading to death, in acute toxicity tests in house crickets. Using isolated smooth and skeletal nerve-muscle preparations, the toxin was shown to lack overt vertebrate toxicity at concentrations up to 1 microM. To further characterize the target of the omega-ACTXs, voltage-clamp analysis using the whole-cell patch-clamp technique was undertaken using cockroach dorsal unpaired median neurons. It is shown here for the first time that omega-ACTX-Ar1a, and its homolog omega-ACTX-Hv1a from Hadronyche versuta, reversibly block both mid-low- (M-LVA) and high-voltage-activated (HVA) insect calcium channel (Ca(v)) currents. This block occurred in the absence of alterations in the voltage-dependence of Ca(v) channel activation, and was voltage-independent, suggesting that omega-ACTX-1 family toxins are pore blockers rather than gating modifiers. At a concentration of 1 microM omega-ACTX-Ar1a failed to significantly affect global K(v) channel currents. However, 1 microM omega-ACTX-Ar1a caused a modest 18% block of insect Na(v) channel currents, similar to the minor block of Na(v) channels reported for other insect Ca(v) channel blockers such as omega-agatoxin IVA. These findings validate both M-LVA and HVA Ca(v) channels as potential targets for insecticides.
7. The Role of Omega-3 Dietary Supplementation in Blepharitis and Meibomian Gland Dysfunction (An AOS Thesis)
PubMed Central
Macsai, Marian S.
2008-01-01
Purpose Blepharitis and meibomian gland dysfunction (MGD) are common sources of complaints from patients. To evaluate the effect on ocular symptoms, ocular findings, and serum and meibomian gland contents, patients with blepharitis and MGD were prospectively evaluated to determine the effects of dietary supplementation with omega-3 fatty acids. Methods In a prospective randomized placebo-controlled masked trial, patients with simple obstructive MGD and blepharitis, who had discontinued all topical medications and tetracyclines, received oral omega-3 dietary supplementation consisting of two 1000-mg capsules 3 times a day. Patients were examined every 3 months for 1 year with the Ocular Surface Disease Index (OSDI) objective clinical measures, including tear production and stability, ocular surface and meibomian gland health, and biochemical plasma, red blood cell (RBC), and meibum evaluation. Primary outcome measures were change in tear breakup time (TBUT), meibum score, and overall OSDI score at 1 year. Results At 1 year, the omega-3 group had a 36% and 31% reduction in their omega-6 to omega-3 fatty acid ratios in RBCs and plasma, respectively (P = .3), whereas the placebo group demonstrated no change. At 12 months, the omega-3 group had an improvement in TBUT, OSDI score, and meibum score. Changes in meibum content were observed in the omega-3 group (P = .21); the level of meibum saturated fatty acids decreased. Conclusions This trial demonstrated a decrease in the RBC and plasma ratios of omega-6 to omega-3 in patients taking omega-3 dietary supplementation, as compared to controls, and improvements in their overall OSDI score, TBUT, and meibum score. This is the first demonstration of an induced change in the fatty acid saturation content in meibum as a result of dietary supplementation with omega-3 fatty acids. PMID:19277245
8. Omega-3 Polyunsaturated Fatty Acids Inhibited Tumor Growth via Preventing the Decrease of Genomic DNA Methylation in Colorectal Cancer Rats.
PubMed
Huang, Qionglin; Wen, Juan; Chen, Guangzhao; Ge, Miaomiao; Gao, Yihua; Ye, Xiaoxia; Liu, Chunan; Cai, Chun
2016-01-01
Omge-3 polyunsaturated fatty acids (PUFAs) exhibited significant effect in inhibiting various tumors. However, the mechanisms of its anticancer role have not been fully demonstrated. The declination of 5-methylcytosine (5 mC) was closely associated with poor prognosis of tumors. To explore whether omega-3 PUFAs influences on DNA methylation level in tumors, colorectal cancer (CRC) rat model were constructed using N-methyl phosphite nitrourea and omega-3 PUFAs were fed to part of the rats during tumor induction. The PUFAs contents in the rats of 3 experimental groups were measured using gas chromatography and 5 mC level were detected by liquid chromatography tandem mass spectrometry. The results showed that tumor incidence in omega-3 treated rats was much lower than in CRC model rats, which confirmed significant antitumor role of omega-3 PUFAs. Six PUFA members categorized to omega-3 and omega-6 families were quantified and the ratio of omega-6/omega-3 PUFAs was remarkably lower in omega-3 PUFAs treatment group than in CRC model group. 5 mC content in omega-3 PUFAs treated rats was higher than in CRC model rats, suggesting omega-3 PUFAs promoted 5 mC synthesis. Therefore, omega-3 PUFAs probably inhibited tumor growth via regulating DNA methylation process, which provided a novel anticancer mechanism of omega-3 PUFAs from epigenetic view.
9. Identification of similarity of skeletal structures in the range 10-5 cm - 1023 cm and the probable role of skeletal assemblies of carbon nanotube-like dust in the large-scale structure of the Universe
Kukushkin, A. B.; Rantsev-Kartinov, V. A.
The role of the dust in astrophysics is analyzed from viewpoint of the hypothesis [1] (and respective proof-of-concept studies [2]) for the self-assembling of a fractal dust in laboratory electric discharges. The presence of skeletal structures of the same distinctive topology (namely, tubules and cartwheels, and their simple combinations) in the range 10-5cm - 1023cm, and a trend toward self-similarity (i.e. assembling of bigger structures from similar smaller ones), are found [3]. These evidences come from the electron micrography of dust deposits in tokamak (10-6cm - 10-3cm) [4], the images of plasma taken in laboratory electric discharges -- tokamaks, Z-pinches, plasma focus and vacuum spark (10-2cm - 10 cm) [2], hail particles (1cm - 10cm), the images of tornado (103cm - 105cm) and of a wide class of objects in space (1011cm - 1023 cm), including the solar coronal mass ejection, supernova remnants, and some galaxies [3]. The similarity of, and a trend toward self-similarity in, these skeletal structures (especially, cartwheels as the structures of essentially non-hydrodynamic nature) suggest all them to possess, similarly to skeletons in the particles of dust and hail, a fractal condensed matter of particular topology of the fractal. Specifically, this matter may be assembled from nanotubular blocks in a way similar to that in the skeletons found [4] in the submicron dust particles. An analysis of the redshift surveys of galaxies and quasars suggests the possibility to draw the above similarity up to 1026cm. This hints at the presence of a baryonic cold dark skeleton (BCDS) of the Universe [5]. The hypothesis of BCDS is shown to have no conflict with major cosmological facts (Hubble expansion and cosmic microwave background's isotropy). REFERENCES: [1] Fusion Energy 1998 (IAEA, Vienna, 1999), Vol. 3, p. 1131. [2] Advances in Plasma Phys. Research, Vol. 2 (Ed. F. Gerard, Nova Science Publishers, New York, 2002), pp. 1-22. [3] Phys. Lett. A 306, 175 (2002). [4
10. CM Carbonaceous Chondrite Lithologies and Their Space Exposure Ages
NASA Technical Reports Server (NTRS)
Zolensky, Michael; Gregory, Timothy; Takenouchi, Atsushi; Nishiizumi, Kunihiko; Trieman, Alan; Berger, Eve; Le, Loan; Fagan, Amy; Velbel, Michael; Imae, Naoya; Yamaguchi, Akira
2015-01-01
The CMs are the most commonly falling C chondrites, and therefore may be a major component of C-class asteroids, the targets of several current and future space missions. Previous work [1] has concluded that CM chondrites fall into at least four distinct cosmic ray space exposure (CRE) age groups (0.1 million years, 0.2 million years, 0.6 million years and greater than 2.0 million years), an unusually large number, but the meaning of these groupings is unclear. It is possible that these meteorites came from different parent bodies which broke up at different times, or instead came from the same parent body which underwent multiple break-up events, or a combination of these scenarios, or something else entirely. The objective of this study is to investigate the diversity of lithologies which make up CM chondrites, in order to determine whether the different exposure ages correspond to specific, different CM lithologies, which permit us to constrain the history of the CM parent body(ies). We have already reported significant petrographic differences among CM chondrites [2-4]. We report here our new results.
11. Initial Single-Mode Rayleigh-Taylor Growth Rates Measured with the OMEGA Laser System
Knauer, J. P.; Meyerhofer, D. D.; Boehly, T. R.; Ofer, D.; Verdon, C. P.; Bradley, D. K.; McKenty, P. W.; Smalyuk, V. A.
1996-11-01
A series of single-mode growth measurements done with the OMEGA laser system are reported. These measurements were done to qualify the laser irradiation and diagnostic suite for future experiments that will use the growth of perturbations at the ablation interface to quantify improvements in irradiation uniformity, reduced growth due to increased ablation velocities, and the effect of increased density scale lengths on the growth rate at the ablation interface. This series of measurements used a laser intensity of 2 × 10^14 W/cm^2 over a spot size of 700 μm for both Gaussian and non-Gaussian shaped pulses with an rms irradiation nonuniformity of 7%. Data were collected with a gated x-ray framing camera with a 10-μm spatial resolution and a 40-ps temporal resolution. This work was supported by the U. S. Department of Energy Office of Inertial Confinement Fusion under cooperative Agreement No. DE-FC03-92SF19460.
12. Single-mode Rayleigh-Taylor growth-rate measurements with the OMEGA laser system
SciTech Connect
Knauer, J. P.; Verdon, C. P.; Meyerhofer, D. D.; Boehly, T. R.; Bradley, D. K.; Smalyuk, V. A.; Ofer, D.; McKenty, P. W.; Glendinning, S. G.; Kalantar, D. H.; Watt, R. G.; Gobby, P. L.; Willi, O.; Taylor, R. J.
1997-04-15
The results from a series of single-mode Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five to six 351-nm laser beams overlapped with total intensities up to 2.5x10{sup 14} W/cm{sup 2}. Experiments were performed with both 3-ns ramp and 3-ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4%-7% over a 600-{mu}m-diam region defined by the 90% intensity contour. The temporal growth of the modulation in optical depth was measured using through-foil radiography and was detected with an x-ray framing camera for CH targets with and without a foam buffer. The growth of both 31-{mu}m and 60-{mu}m wavelength perturbations was found to be in good agreement with ORCHID simulations when the experimental details, including noise, were included. The addition of a 30-mg/cc, 100-{mu}m-thick polystyrene foam buffer layer resulted in reduced growth of the 31-{mu}m perturbation and essentially unchanged growth for the 60-{mu}m case when compared to targets without foam.
13. Single-mode Rayleigh-Taylor growth-rate measurements with the OMEGA laser system
Knauer, J. P.; Verdon, C. P.; Meyerhofer, D. D.; Boehly, T. R.; Bradley, D. K.; Smalyuk, V. A.; Ofer, D.; McKenty, P. W.; Glendinning, S. G.; Kalantar, D. H.; Watt, R. G.; Gobby, P. L.; Willi, O.; Taylor, R. J.
1997-04-01
The results from a series of single-mode Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five to six 351-nm laser beams overlapped with total intensities up to 2.5×1014W/cm2. Experiments were performed with both 3-ns ramp and 3-ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4%-7% over a 600-μm-diam region defined by the 90% intensity contour. The temporal growth of the modulation in optical depth was measured using through-foil radiography and was detected with an x-ray framing camera for CH targets with and without a foam buffer. The growth of both 31-μm and 60-μm wavelength perturbations was found to be in good agreement with ORCHID simulations when the experimental details, including noise, were included. The addition of a 30-mg/cc, 100-μm-thick polystyrene foam buffer layer resulted in reduced growth of the 31-μm perturbation and essentially unchanged growth for the 60-μm case when compared to targets without foam.
14. Single-mode Rayleigh-Taylor growth-rate measurements with the OMEGA laser system
SciTech Connect
Knauer, J.P.; Verdon, C.P.; Meyerhofer, D.D.; Boehly, T.R.; Bradley, D.K.; Smalyuk, V.A.; Ofer, D.; McKenty, P.W.; Glendinning, S.G.; Kalantar, D.H.; Watt, R.G.; Gobby, P.L.; Willi, O.; Taylor, R.J.
1997-04-01
The results from a series of single-mode Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five to six 351-nm laser beams overlapped with total intensities up to 2.5{times}10{sup 14}W/cm{sup 2}. Experiments were performed with both 3-ns ramp and 3-ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4{percent}{endash}7{percent} over a 600-{mu}m-diam region defined by the 90{percent} intensity contour. The temporal growth of the modulation in optical depth was measured using through-foil radiography and was detected with an x-ray framing camera for CH targets with and without a foam buffer. The growth of both 31-{mu}m and 60-{mu}m wavelength perturbations was found to be in good agreement with {ital ORCHID} simulations when the experimental details, including noise, were included. The addition of a 30-mg/cc, 100-{mu}m-thick polystyrene foam buffer layer resulted in reduced growth of the 31-{mu}m perturbation and essentially unchanged growth for the 60-{mu}m case when compared to targets without foam. {copyright} {ital 1997 American Institute of Physics.}
15. Bremsstrahlung measurements for characterization of intense short-pulse, laser produced fast electrons with OMEGA EP
Daykin, Tyler; Sawada, Hiroshi; Sentoku, Yasuhiko; Pandit, Rishi; Chen, Cliff; Beg, Farhat; Chen, Hui; McLean, Harry; Patel, Pravesh; Tommasini, Riccardo
2016-10-01
Understanding relativistic fast electron generation and transport inside solids is important for applications such as generation of high energy x-ray sources and fast ignition. An experiment was carried out to study the scaling of the fast electron spectrum and bremsstrahlung generation in multi-pico second laser interactions using 1 ps and 10 ps OMEGA EP short-pulse beam to generate fast electrons at a similar peak intensity of 5x1018 W/cm2. The bremsstrahlung produced by collisions of the fast electrons with background ions was recorded using differential filter stacked spectrometers. A preliminary analysis with a Monte Carlo Code ITS shows that the electrons injection having an electron slope 1.8 MeV matched well with the high energy component of the 1 ps and 10 ps bremsstrahlung measurements. Details of the data analysis and modeling with Monte Carlo and a hybrid particle-in-cell codes will be presented at the conference. Work supported by the UNR Office of the Provost and by DOE/OFES under Contract No. DE-SC0008827. This collaborative work was partially supported under the auspices of the US DOE by LLNL under Contracts No. DE-AC52-07NA27344 and No. DE-FG-02-05ER54834.
16. Demonstration of imaging X-ray Thomson scattering on OMEGA EP
Belancourt, Patrick X.; Theobald, Wolfgang; Keiter, Paul A.; Collins, Tim J. B.; Bonino, Mark J.; Kozlowski, Pawel M.; Regan, Sean P.; Drake, R. Paul
2016-11-01
Foams are a common material for high-energy-density physics experiments because of low, tunable densities, and being machinable. Simulating these experiments can be difficult because the equation of state is largely unknown for shocked foams. The focus of this experiment was to develop an x-ray scattering platform for measuring the equation of state of shocked foams on OMEGA EP. The foam used in this experiment is resorcinol formaldehyde with an initial density of 0.34 g/cm3. One long-pulse (10 ns) beam drives a shock into the foam, while the remaining three UV beams with a 2 ns square pulse irradiate a nickel foil to create the x-ray backlighter. The primary diagnostic for this platform, the imaging x-ray Thomson spectrometer, spectrally resolves the scattered x-ray beam while imaging in one spatial dimension. Ray tracing analysis of the density profile gives a compression of 3 ± 1 with a shock speed of 39 ± 6 km/s. Analysis of the scattered x-ray spectra gives an upper bound temperature of 20 eV.
17. Proper balance of omega-3 and omega-6 fatty acid supplements with topical cyclosporine attenuated contact lens-related dry eye syndrome.
PubMed
Wang, Ling; Chen, Xi; Hao, Jingfang; Yang, Lu
2016-12-01
Essential fatty acids had been applied in the treatment of dry eye syndrome (DES), but the effects of different combinations of fatty acids have not been investigated. 360 long-term contact lens wearers were included in this double-blinded study. Omega-3 and omega-6 fatty acids were combined in different ratios and supplied to the participants that were randomly divided into six groups, and the effects of different essential fatty acids mixture on DES with or without topical cyclosporine were investigated. More than half of long-term contact lens wearers suffered from DES, which were found to be attenuated by oral supplement of properly balanced O3FA and O6FA fatty acid. The topical cyclosporine treatment considerably inhibited the production of cytokines compared to the cyclosporine negative groups, which further relieved DES. Proper balance of omega-3 and omega-6 fatty acid combination significantly alleviated contact lens-related DES.
18. A model for sunspot associated emission at 6 cm wavelength
NASA Technical Reports Server (NTRS)
Alissandrakis, C. E.; Kundu, M. R.; Lantos, P.
1980-01-01
Two-dimensional maps of total intensity and circular polarization of a sunspot region at 6 cm have been calculated using a simple model for the chromosphere-corona transition region and observations of the longitudinal component of the photospheric magnetic field. The calculations are in good agreement with the high resolution observations of the same sunspot region at 6 cm, obtained with the Westerbork Synthesis Radio Telescope. It is shown that the 6 cm radiation is predominantly due to gyroresonance absorption process at the second and third harmonics of the gyrofrequency (H = 900-600 G). Estimates of the conductive flux and the electron density in the transition region above the sunspot are also given.
19. VLA observations of Uranus at 1. 3-20 cm
SciTech Connect
De Pater, I.; Gulkis, S.
1988-08-01
Observations of Uranus, obtained with resolution 0.5-1.2 arcsec at wavelengths 1.3, 2, 6, and 20 cm using the A and B configurations of the VLA in June-July 1982, October 1983, and February 1984, are reported. The disk-averaged brightness temperatures (DABTs) are determined by model fitting, and the results are presented in extensive graphs and contour maps and characterized in detail. Findings discussed include: (1) an overall spectrum which is relatively flat above 6 cm, (2) 1.3-6-cm brightness which is concentrated nearer to the pole than to the subsolar point, and (3) small changes in DABT from 1982 to 1983/1984 (consistent with an explanation based on a pole-equator temperature gradient). 16 references.
20. Differentiating CDM and baryon isocurvature models with 21 cm fluctuations
SciTech Connect
Kawasaki, Masahiro; Sekiguchi, Toyokazu; Takahashi, Tomo E-mail: sekiguti@icrr.u-tokyo.ac.jp
2011-10-01
We discuss how one can discriminate models with cold dark matter (CDM) and baryon isocurvature fluctuations. Although current observations such as cosmic microwave background (CMB) can severely constrain the fraction of such isocurvature modes in the total density fluctuations, CMB cannot differentiate CDM and baryon ones by the shapes of their power spectra. However, the evolution of CDM and baryon density fluctuations are different for each model, thus it would be possible to discriminate those isocurvature modes by extracting information on the fluctuations of CDM/baryon itself. We discuss that observations of 21 cm fluctuations can in principle differentiate these modes and demonstrate to what extent we can distinguish them with future 21 cm surveys. We show that, when the isocurvature mode has a large blue-tilted initial spectrum, 21 cm surveys can clearly probe the difference.
1. High-resolution comparative modeling with RosettaCM.
PubMed
Song, Yifan; DiMaio, Frank; Wang, Ray Yu-Ruei; Kim, David; Miles, Chris; Brunette, Tj; Thompson, James; Baker, David
2013-10-08
We describe an improved method for comparative modeling, RosettaCM, which optimizes a physically realistic all-atom energy function over the conformational space defined by homologous structures. Given a set of sequence alignments, RosettaCM assembles topologies by recombining aligned segments in Cartesian space and building unaligned regions de novo in torsion space. The junctions between segments are regularized using a loop closure method combining fragment superposition with gradient-based minimization. The energies of the resulting models are optimized by all-atom refinement, and the most representative low-energy model is selected. The CASP10 experiment suggests that RosettaCM yields models with more accurate side-chain and backbone conformations than other methods when the sequence identity to the templates is greater than ∼15%.
2. EPA Awards $10.3 Million to Clean Up New England Brownfield Sites, Protect Health in Communities EPA Pesticide Factsheets EPA has awarded more than$10.3 million in Brownfield grants to municipalities and organizations working to protect people's health by assessing and cleaning up contaminated parcels in New England communities.
3. Omega 3 Fatty Acids: Novel Neurotherapeutic Targets for Cognitive Dysfunction in Mood Disorders and Schizophrenia?
PubMed
Knöchel, Christian; Voss, Martin; Grüter, Florian; Alves, Gilberto S; Matura, Silke; Sepanski, Beate; Stäblein, Michael; Wenzler, Sofia; Prvulovic, David; Carvalho, André F; Oertel-Knöchel, Viola
2015-01-01
An increasing body of evidences from preclinical as well as epidemiological and clinical studies suggest a potential beneficial role of dietary intake of omega-3 fatty acids for cognitive functioning. In this narrative review, we will summarize and discuss recent findings from epidemiological, interventional and experimental studies linking dietary consumption of omega-3 fatty acids to cognitive function in healthy adults. Furthermore, affective disorders and schizophrenia (SZ) are characterized by cognitive dysfunction encompassing several domains. Cognitive dysfunction is closely related to impaired functioning and quality of life across these conditions. Therefore, the current review focues on the potential influence of omega-3 fatty acids on cognition in SZ and affective disorders. In sum, current data predominantly from mechanistic models and animal studies suggest that adjunctive omega-3 fatty acid supplementation could lead to improved cognitive functioning in SZ and affective disorders. However, besides its translational promise, evidence for clinical benefits in humans has been mixed. Notwithstanding evidences indicate that adjunctive omega-3 fatty acids may have benefit for affective symptoms in both unipolar and bipolar depression, to date no randomized controlled trial had evaluated omega-3 as cognitive enhancer for mood disorders, while a single published controlled trial suggested no therapeutic benefit for cognitive improvement in SZ. Considering the pleiotropic mechanisms of action of omega-3 fatty acids, the design of well-designed controlled trials of omega-3 supplementation as a novel, domain-specific, target for cognitive impairment in SZ and affective disorders is warranted.
4. Omega 3 Fatty Acids: Novel Neurotherapeutic Targets for Cognitive Dysfunction in Mood Disorders and Schizophrenia?
PubMed Central
Knöchel, Christian; Voss, Martin; Grter, Florian; Alves, Gilberto S.; Matura, Silke; Sepanski, Beate; Stäblein, Michael; Wenzler, Sofia; Prvulovic, David; Carvalho, André F.; Oertel-Knöchel, Viola
2015-01-01
An increasing body of evidences from preclinical as well as epidemiological and clinical studies suggest a potential beneficial role of dietary intake of omega-3 fatty acids for cognitive functioning. In this narrative review, we will summarize and discuss recent findings from epidemiological, interventional and experimental studies linking dietary consumption of omega-3 fatty acids to cognitive function in healthy adults. Furthermore, affective disorders and schizophrenia (SZ) are characterized by cognitive dysfunction encompassing several domains. Cognitive dysfunction is closely related to impaired functioning and quality of life across these conditions. Therefore, the current review focues on the potential influence of omega-3 fatty acids on cognition in SZ and affective disorders. In sum, current data predominantly from mechanistic models and animal studies suggest that adjunctive omega-3 fatty acid supplementation could lead to improved cognitive functioning in SZ and affective disorders. However, besides its translational promise, evidence for clinical benefits in humans has been mixed. Notwithstanding evidences indicate that adjunctive omega-3 fatty acids may have benefit for affective symptoms in both unipolar and bipolar depression, to date no randomized controlled trial had evaluated omega-3 as cognitive enhancer for mood disorders, while a single published controlled trial suggested no therapeutic benefit for cognitive improvement in SZ. Considering the pleiotropic mechanisms of action of omega-3 fatty acids, the design of well-designed controlled trials of omega-3 supplementation as a novel, domain-specific, target for cognitive impairment in SZ and affective disorders is warranted. PMID:26467414
5. Omega flight-test data reduction sequence. [computer programs for reduction of navigation data
NASA Technical Reports Server (NTRS)
Lilley, R. W.
1974-01-01
Computer programs for Omega data conversion, summary, and preparation for distribution are presented. Program logic and sample data formats are included, along with operational instructions for each program. Flight data (or data collected in flight format in the laboratory) is provided by the Ohio University Omega receiver base in the form of 6-bit binary words representing the phase of an Omega station with respect to the receiver's local clock. All eight Omega stations are measured in each 10-second Omega time frame. In addition, an event-marker bit and a time-slot D synchronizing bit are recorded. Program FDCON is used to remove data from the flight recorder tape and place it on data-processing cards for later use. Program FDSUM provides for computer plotting of selected LOP's, for single-station phase plots, and for printout of basic signal statistics for each Omega channel. Mean phase and standard deviation are printed, along with data from which a phase distribution can be plotted for each Omega station. Program DACOP simply copies the Omega data deck a controlled number of times, for distribution to users.
6. Functional beverage products using caseinate–omega-3 oil-oat beta glucan emulsions
Technology Transfer Automated Retrieval System (TEKTRAN)
Beverages with soluble dietary fiber and Omega 3 oil are highly desired by health conscious consumers. However, Omega 3 oil is prone to oxidation and accompanying deterioration of sensory profiles; there is an issue to incorporate soluble fiber into beverage products that will not interfere with oxi...
7. Omega-3 Fatty Acids for Autistic Spectrum Disorder: A Systematic Review
ERIC Educational Resources Information Center
Bent, Stephen; Bertoglio, Kiah; Hendren, Robert L.
2009-01-01
We conducted a systematic review to determine the safety and efficacy of omega-3 fatty acids for autistic spectrum disorder (ASD). Articles were identified by a search of MEDLINE, EMBASE, and the Cochrane Database using the terms autism or autistic and omega-3 fatty acids. The search identified 143 potential articles and six satisfied all…
8. [Shrinkage In the Squared Multiple Correlation Coefficient and Unbiased Estimates of Treatment Effects Using Omega Squared.
ERIC Educational Resources Information Center
Dalton, Starrett
The amount of variance accounted for by treatment can be estimated with omega squared or with the squared multiple correlation coefficient. Monte Carlo methods were employed to compare omega squared, the squared multiple correlation coefficient, and the squared multiple correlation coefficient to which a shrinkage formula had been applied, in…
9. Extracting the {Omega}{sup -} electric quadrupole moment from lattice QCD data
SciTech Connect
Ramalho, G.; Pena, M. T.
2011-03-01
The {Omega}{sup -} has an extremely long lifetime, and is the most stable of the baryons with spin 3/2. Therefore the {Omega}{sup -} magnetic moment is very accurately known. Nevertheless, its electric quadrupole moment was never measured, although estimates exist in different formalisms. In principle, lattice QCD simulations provide at present the most appropriate way to estimate the {Omega}{sup -} form factors, as function of the square of the transferred four-momentum, Q{sup 2}, since it describes baryon systems at the physical mass for the strange quark. However, lattice QCD form factors, and in particular G{sub E2}, are determined at finite Q{sup 2} only, and the extraction of the electric quadrupole moment, Q{sub {Omega}}{sup -}=G{sub E2}(0)(e/2M{sub {Omega}}), involves an extrapolation of the numerical lattice results. In this work, we reproduce the lattice QCD data with a covariant spectator quark model for {Omega}{sup -} which includes a mixture of S and two D states for the relative quark-diquark motion. Once the model is calibrated, it is used to determine Q{sub {Omega}}{sup -}. Our prediction is Q{sub {Omega}}{sup -}=(0.96{+-}0.02)x10{sup -2} efm{sup 2}[G{sub E2}(0)=0.680{+-}0.012].
10. Radiative Corrections to Asymmetry Parameter in the {Omega}{sup -{yields}{Lambda}}+K{sup -} Decay
SciTech Connect
Queijeiro, A.
2010-07-29
We compute the radiative corrections, to first order in the fine structure constant {alpha}, to the asymmetry parameter {alpha}{sub {Omega}}of the {Omega}{sup -{yields}{Lambda}}+K{sup -} decay. We use previous results where Sirlin's procedure is used to separate the radiative corrections into two parts, one independent model contribution and a model dependent one.
11. Novel Omega-3 Fatty Acid Epoxygenase Metabolite Reduces Kidney Fibrosis
PubMed Central
Sharma, Amit; Khan, Md. Abdul Hye; Levick, Scott P.; Lee, Kin Sing Stephen; Hammock, Bruce D.; Imig, John D.
2016-01-01
Cytochrome P450 (CYP) monooxygenases epoxidize the omega-3 polyunsaturated fatty acid (PUFA) docosahexaenoic acid into novel epoxydocosapentaenoic acids (EDPs) that have multiple biological actions. The present study determined the ability of the most abundant EDP regioisomer, 19,20-EDP to reduce kidney injury in an experimental unilateral ureteral obstruction (UUO) renal fibrosis mouse model. Mice with UUO developed kidney tubular injury and interstitial fibrosis. UUO mice had elevated kidney hydroxyproline content and five-times greater collagen positive fibrotic area than sham control mice. 19,20-EDP treatment to UUO mice for 10 days reduced renal fibrosis with a 40%–50% reduction in collagen positive area and hydroxyproline content. There was a six-fold increase in kidney α-smooth muscle actin (α-SMA) positive area in UUO mice compared to sham control mice, and 19,20-EDP treatment to UUO mice decreased α-SMA immunopositive area by 60%. UUO mice demonstrated renal epithelial-to-mesenchymal transition (EMT) with reduced expression of the epithelial marker E-cadherin and elevated expression of multiple mesenchymal markers (FSP-1, α-SMA, and desmin). Interestingly, 19,20-EDP treatment reduced renal EMT in UUO by decreasing mesenchymal and increasing epithelial marker expression. Overall, we demonstrate that a novel omega-3 fatty acid metabolite 19,20-EDP, prevents UUO-induced renal fibrosis in mice by reducing renal EMT. PMID:27213332
12. Omega-3 Fatty acids and hippocampal neurogenesis in depression.
PubMed
Kang, Jing X; Gleason, Erin D
2013-06-01
The mammalian brain and central nervous system are especially dependent on the omega-3 (n-3) fatty acid docosahexaenoic acid (DHA) for normative signaling and function, and research suggests that n-3 fatty acid deficiencies are one contributing factor in the increasing prevalence of depressive disorders. However, the reasons for which n-3 fatty acids and mood are connected remain unknown. Atrophy in the hippocampus is one of the most significant neuroanatomical findings in depressed patients, and current therapies for depression tend to increase hippocampal neurogenesis. We recently discovered that the fat-1 transgenic mouse, which has enriched levels of DHA in the brain because it can convert n-6 to n-3 fatty acids, exhibits increased hippocampal neurogenesis. This finding suggests a mechanism by which omega-3 could influence depression and mood; here we expand on the argument that n-3 fatty acids, and DHA in particular, may help prevent and treat depression by virtue of their effects on neurogenesis in the hippocampus. Because DHA can be obtained through the diet, increasing DHA intake in depressed patients or those at risk for depression may be one way of managing the disease and perhaps providing aid to those who have not been able to achieve remission via pharmacological means.
13. AN ECLIPSING BLUE STRAGGLER IN THE GLOBULAR CLUSTER {omega} CENTAURI
SciTech Connect
Li Kai; Qian Shengbang
2012-12-01
{omega} Centauri is the largest globular cluster in the Milky Way and hence contains the largest number of variable stars within a single cluster. The results of photometric solutions are presented for the EA-type binary V239 in this cluster. According to our analysis, V239 is a typical Algol-type binary. We obtain M = 1.20 {+-} 0.10 M{sub Sun }, R = 1.21 {+-} 0.03 R{sub Sun }, and L = 13.68 {+-} 0.63 L{sub Sun} for the primary component. The secondary component has M = 0.07 {+-} 0.02 M{sub Sun }, R = 0.90 {+-} 0.03 R{sub Sun }, and L = 2.17 {+-} 0.14 L{sub Sun }. The binary system is located in the blue straggler region on the color-magnitude diagram of {omega} Centauri and the mass of the primary component exceeds the mass of a turnoff star. Therefore, we think that V239 is a blue straggler and that V239 was formed by mass transfer from the present secondary component to the present primary.
14. Omega-3 fatty acids as adjunctive therapy in Crohns disease.
PubMed
Macdonald, Angie
2006-01-01
Crohns disease is an inflammatory bowel disease that can have a significant impact on the health of those afflicted. The etiology of the disease is unknown, but genetic, environmental, dietary, and immunological factors are thought to be involved. Multiple nutrients can become depleted during active disease due to inadequate intake or malabsorption. Preventing these deficiencies is paramount in the care of those suffering from Crohns disease. Often the traditional treatments (medications) have limited effectiveness and negative side effects that inhibit their use. Enteral nutrition has promising therapeutic benefits, but its use is often limited to the pediatric population due to poor patient acceptability. Omega-3 fatty acids have been investigated for their anti-inflammatory properties as an alternative to traditional care. This article reviews the etiology of Crohns disease, nutritional deficiencies, traditional treatments, and the use of omega-3 fatty acids in the prevention of Crohns recurrence. The results from clinical trials have been conflicting, but a new fish oil preparation that limits the side effects of traditional fish oil therapy shows promise as an adjunctive treatment for Crohns disease. Continued research is needed to validate these findings.
15. Initial results from the DSPlanar experiments on OMEGA
Dodd, E. S.; Merritt, E. C.; Montgomery, D. S.; Daughton, W.; Schmidt, D. W.; Cardenas, T.; Wilson, D. C.; Batha, S. H.
2016-10-01
Recently, LANL has begun a project aimed ultimately at fielding a neutron-producing double-shell capsule at the National Ignition Facility (NIF). Initial experiments have begun at both the NIF and OMEGA laser facilities over the last year. At OMEGA, halfraum-driven planar targets will be used to study physics issues important to double shell implosions, but outside of a convergent geometry. In particular, side-on radiography through a tube has advantages over imaging through the hohlraum and double-shell capsule at NIF. We plan to study a number physics issues with this platform, including both 1-d and higher dimensional effects. In 1-d, momentum transfer from the ablator to the inner shell, and the effect of pre-heat on the inner shell can be studied. Higher dimensional effects, in the form of hydrodynamic instabilities, can also be studied. Pre-heat expansion of the inner shell can lead to an unstable interface, which can be mitigated by a tamper layer. Manufacturing tolerances can be used to mitigate against feature-driven instability growth, such as from a glue joint or fill tube. Initial results on the amount pre-heat from various ablator materials will be given, along with a discussion of future plans. Supported under the US DOE by the LANS, LLC under contract DE-AC52-06NA25396. LA-UR-16-25044.
16. Omega-3 polyunsaturated fatty acids in the treatment of hypertriglyceridaemia.
PubMed
Pirillo, Angela; Catapano, Alberico Luigi
2013-12-20
Hypertriglyceridaemia (HTG) is an independent risk factor for cardiovascular disease; high-risk patients with HTG, such as those with metabolic syndrome or diabetes, may benefit from hypolipidaemic therapies. Several lipid-lowering drugs act by reducing triglyceride (TG) levels, including fibrates, nicotinic acid and omega-3 fatty acids. The omega-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) dose-dependently reduce plasma TG levels; the effect tends to be greater in patients with higher TG levels at baseline. Evidence from clinical trials suggests that EPA+DHA doses of ≥ 2 g/day are required to achieve significant effects. The optimal TG-lowering doses of EPA+DHA are 3-4 g/day, with little evidence to support lipid-altering efficacy of doses of EPA and DHA <1g/day. Predicted changes in fasting serum TG levels at the recommended dietary intakes of EPA and/or DHA of 200-500 mg/day are -3.1% to -7.2%. Reductions of plasma TG levels at the optimal doses are from 25-35% up to 45% in the presence of severely elevated TG levels (≥ 500 mg/dl; ≥ 5.65 mmol/l), along with a reduction in non-high-density lipoprotein-cholesterol (non-HDL-C) and an increase in HDL-C. This observation has also been confirmed in statin-treated patients.
17. CATASTROPHIC QUENCHING IN {alpha}{Omega} DYNAMOS REVISITED
SciTech Connect
Hubbard, Alexander; Brandenburg, Axel
2012-03-20
At large magnetic Reynolds numbers, magnetic helicity evolution plays an important role in astrophysical large-scale dynamos. The recognition of this fact led to the development of the dynamical {alpha} quenching formalism, which predicts catastrophically low mean fields in open systems. Here, we show that in oscillatory {alpha}{Omega} dynamos this formalism predicts an unphysical magnetic helicity transfer between scales. An alternative technique is proposed where this artifact is removed by using the evolution equation for the magnetic helicity of the total field in the shearing advective gauge. In the traditional dynamical {alpha} quenching formalism, this can be described by an additional magnetic helicity flux of small-scale fields that does not appear in homogeneous {alpha}{sup 2} dynamos. In {alpha}{Omega} dynamos, the alternative formalism is shown to lead to larger saturation fields than what has been obtained in some earlier models with the traditional formalism. We have compared the predictions of the two formalisms to results of direct numerical simulations, finding that the alternative formulation provides a better fit. This suggests that worries about catastrophic dynamo behavior in the limit of large magnetic Reynolds number are unfounded.
18. Laboratory astrophysical collisionless shock experiments on Omega and NIF
Park, Hye-Sook; Ross, J. S.; Huntington, C. M.; Fiuza, F.; Ryutov, D.; Casey, D.; Drake, R. P.; Fiksel, G.; Froula, D.; Gregori, G.; Kugland, N. L.; Kuranz, C.; Levy, M. C.; Li, C. K.; Meinecke, J.; Morita, T.; Petrasso, R.; Plechaty, C.; Remington, B.; Sakawa, Y.; Spitkovsky, A.; Takabe, H.; Zylstra, A. B.
2016-03-01
We are performing scaled astrophysics experiments on Omega and on NIF. Laser driven counter-streaming interpenetrating supersonic plasma flows can be studied to understand astrophysical electromagnetic plasma phenomena in a controlled laboratory setting. In our Omega experiments, the counter-streaming flow plasma state is measured using Thomson scattering diagnostics, demonstrating the plasma flows are indeed super-sonic and in the collisionless regime. We observe a surprising additional electron and ion heating from ion drag force in the double flow experiments that are attributed to the ion drag force and electrostatic instabilities. [1] A proton probe is used to image the electric and magnetic fields. We observe unexpected large, stable and reproducible electromagnetic field structures that arise in the counter-streaming flows [2]. The Biermann battery magnetic field generated near the target plane, advected along the flows, and recompressed near the midplane explains the cause of such self-organizing field structures [3]. A D3He implosion proton probe image showed very clear filamentary structures; three-dimensional Particle-In-Cell simulations and simulated proton radiography images indicate that these filamentary structures are generated by Weibel instabilities and that the magnetization level (ratio of magnetic energy over kinetic energy in the system) is ∼0.01 [4]. These findings have very high astrophysical relevance and significant implications. We expect to observe true collisionless shock formation when we use >100 kJ laser energy on NIF.
19. Shock-Wave Acceleration of Protons on OMEGA EP
Haberberger, D.; Froula, D. H.; Pak, A.; Link, A.; Patel, P.; Fiuza, F.; Tochitsky, S.; Joshi, C.
2016-10-01
The creation of an electrostatic shock wave and ensuing ion acceleration is studied on the OMEGA EP Laser System at the Laboratory for Laser Energetics. Previous work using a 10- μm CO2 laser in a H2 gas jet shows promising results for obtaining narrow spectral features in the accelerated proton spectra. Scaling the shock-wave acceleration mechanism to the 1- μm-wavelength drive laser makes it possible to use petawatt-scale laser systems such as OMEGA-EP, but involves tailoring of the plasma profile. To accomplish the necessitated sharp rise to near-critical plasma density and a long exponential fall, an 1- μm-thick CH foil is illuminated on the back side by thermal x rays produced from an irradiated gold foil. The plasma density is measured using the fourth-harmonic probe system, the accelerating fields are probed using an orthogonal proton source, and the accelerated protons and ions are detected with a Thomson parabola. These results will be presented and compared with particle-in-cell simulations. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and LLNL's Laboratory Directed Research and Development program under project 15-LW-095.
20. Two crystal x-ray spectrometers for OMEGA experiments
Reverdin, C.; Casner, A.; Girard, F.; Lecherbourg, L.; Loupias, B.; Tassin, V.; Philippe, F.
2016-11-01
Two x-ray spectrometers have been built for x-ray spectroscopy of laser-produced plasmas on OMEGA at the Laboratory for Laser Energetics (LLE) by Commissariat a ̀ l'Energie Atomique et aux énergies alternatives (CEA). The accessible photon energy range is from 1.5 to 20 keV. The first spectrometer, called X-ray CEA Crystal Spectrometer with a Charge-Injection Device (XCCS-CID), records three spectra with three crystals coupled to a time integrated CID camera. The second one, called X-ray CEA Crystal Spectrometer (XCCS) with a framing camera, is time resolved and records four spectra with two crystals on the four frames of a framing camera. Cylindrical crystals are used in Johan geometry. Each spectrometer is positioned with a ten-inch manipulator inside the OMEGA target chamber. In each experiment, after choosing a spectral window, a specific configuration is designed and concave crystals are precisely positioned on a board with angled wedges and spacers. Slits on snouts enable 1D spatial resolution to distinguish spectra emitted from different parts of the target.
1. Cycle life testing of 8-cm mercury ion thruster cathodes
NASA Technical Reports Server (NTRS)
Wintucky, E. G.
1976-01-01
Two main cathodes have successfully completed 2800 and 1980 cycles and three neutralizers, 3928, 3050, and 2850 cycles in ongoing cycle life tests of flight-type cathode-isolator-vaporizer and neutralizer-isolator-vaporizer assemblies for the 4.45 mN 8-cm Hg ion thruster system. Each cycle included one hour of cathode operation. Starting and operating conditions simulated those expected in a typical auxiliary propulsion mission duty cycle. This paper presents the cycle life test results and also results of an insert comparison test which led to the selection of a rolled foil insert type for the 8-cm Engineering Model Thruster cathodes.
2. Cycle life testing of 8-cm mercury ion thruster cathodes
NASA Technical Reports Server (NTRS)
Wintucky, E. G.
1976-01-01
Two main cathodes have successfully completed 2800 and 1980 cycles and three neutralizers, 3928, 3050, and 2850 cycles in ongoing cycle life tests of flight-type cathode-isolator-vaporizer and neutralizer-isolator-vaporizer assemblies for the 4.45 mN 8-cm Hg ion thruster system. Each cycle included one hour of cathode operation. Starting and operating conditions simulated those expected in a typical auxiliary propulsion mission duty cycle. The cycle life test results are presented along with results of an insert comparison test which led to the selection of a rolled foil insert type for the 8-cm Engineering Model Thruster cathodes.
3. 21 cm radiation: A new probe of fundamental physics
Khatri, Rishi; Wandelt, Benjamin D.
2010-11-01
New low frequency radio telescopes currently being built open up the possibility of observing the 21 cm radiation from redshifts 200 > z > 30, also known as the dark ages, see Furlanetto, Oh, & Briggs(2006) for a review. At these high redshifts, Cosmic Microwave Background (CMB) radiation is absorbed by neutral hydrogen at its 21 cm hyperfine transition. This redshifted 21 cm signal thus carries information about the state of the early Universe and can be used to test fundamental physics. The 21 cm radiation probes a volume of the early Universe on kpc scales in contrast with CMB which probes a surface (of some finite thickness) on Mpc scales. Thus there is many orders of more information available, in principle, from the 21 cm observations of dark ages. We have studied the constraints these observations can put on the variation of fundamental constants (Khatri & Wandelt(2007)). Since the 21 cm signal depends on atomic physics it is very sensitive to the variations in the fine structure constant and can place constraints comparable to or better than the other astrophysical experiments (Δα/α= < 10-5) as shown in Figure 1. Making such observations will require radio telescopes of collecting area 10 - 106 km2 compared to ~ 1 km2 of current telescopes, for example LOFAR. We should also expect similar sensitivity to the electron to proton mass ratio. One of the challenges in observing this 21 cm cosmological signal is the presence of the synchrotron foregrounds which is many orders of magnitude larger than the cosmological signal but the two can be separated because of their different statistical nature (Zaldarriaga, Furlanetto, & Hernquist(2004)). Terrestrial EM interference from radio/TV etc. and Earth's ionosphere poses problems for telescopes on ground which may be solved by going to the Moon and there are proposals for doing so, one of which is the Dark Ages Lunar Interferometer (DALI). In conclusion 21 cm cosmology promises a large wealth of data and provides
4. WSRC Am/Cm Stabilization Program - Cylindrical Induction Melter Studies
SciTech Connect
Henderson, W.A.
1999-02-17
1.1.1 Kilogram quantities of Americium and Curium isotopes (Am/Cm) have been produced at the U.S. Department of Energy (DOE), Savannah River Site (SRS), Aiken, South Carolina. These highly radioactive isotopes have both government and commercial value and are currently stored as a nitric acid solution at the Savannah River Site. The material represents the largest source term in the F canyon at SRS. It is proposed that the Am/Cm material be vitrified to stabilize the material for long term, recoverable storage. This paper reviews the progress made during the process development phase of this program using the Cylindrical Induction Melter.
5. Evidence for live 247Cm in the early solar system
USGS Publications Warehouse
Tatsumoto, M.; Shimamura, T.
1980-01-01
Variations of the 238U/235U ratio in the Allende meteorite, ranging from -35% to + 19%, are interpreted as evidence of live 247Cm in the early Solar System. The amounts of these and other r-products in the Solar System indicate values of (9,000??3,000) Myr for the age of the Galaxy and ??? 8 Myr for the time between the end of nucleosynthesis and the formation of meteoritic grains. Three possible explanations are presented for the different values of the latter time period which are indicated by the decay products of 247Cm, 26Al, 244Pu and 129I. ?? 1980 Nature Publishing Group.
6. Increased capabilities of the 30-cm diameter Hg ion thruster
NASA Technical Reports Server (NTRS)
Rawlin, V. K.; Hawkins, C. E.
1979-01-01
Some space flight missions require advanced ion thrusters which operate at conditions much different than those for which the baseline 30-cm Hg thruster was developed. Results of initial tests of a 30-cm Hg thruster with two and three grid ion accelerating systems, operated at higher values of both thrust and power and over a greater range of specific impulse than the baseline conditions are presented. Thruster lifetime at increased input power was evaluated both by extended tests and real time spectroscopic measurements.
7. Inert gas test of two 12-cm magnetostatic thrusters
NASA Technical Reports Server (NTRS)
Ramsey, W. D.
1982-01-01
Comparative performance tests were conducted with 12 cm line and ring magnetic cusp thrusters. Shell anode and magnetoelectrostatic containment boundary anode configurations were evaluated with each magnet array. The best performance was achieved with the 12-cm ring cusp-shell anode configuration. Argon operation of this configuration produced 65-81 percent mass utilization efficiency at 170-208 watts/single-charged-equivalent (SCE) ampere beam. Xenon test results showed 75-95 percent utilization at 162-188 watts/SCE ampere beam.
8. [The effect of diet ratio of polyunsaturated fatty acids of omega-3 and omega-6 families on activity of aminotransferases and gamma-glutamyltransferase in rat blood serum].
PubMed
Ketsa, O V; Marchenko, M M
2014-01-01
The effect of diet fat compositions with various ratio of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) on alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT) activities in blood serum of 45 white mongrel rats weighing 90-110 g (9 animals in group) has been investigated. Fat components in the semi-synthetic diet, compiled on the basis of AIN-93 diet, and sources of omega-6 and omega-3 PUFA were presented by sunflower oil, soybean oil and fish oil. It has been shown that four-week inclusion of linoleic acid (LA) and alpha-linolenic acid (alpha-LNA) in a ratio of 7:1 into the diet (soybean oil) as well as use of only omega-6 PUFA (sunflower oil) has lead to an increase in the activity of ALT and GGT in rat blood serum compared to control animals treated with the complex of linolenic, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid through the mixture of sunflower oil and fish oil (9:1) with the ratio of omega-6 and omega-3 PUFA 7:1. Along with this, the AST:ALT ratio (de Ritis ratio) was lower (p < 0.05) as compared with the control group of rat, amounting respectively 0.92 +/- 0.08 and 0.79 +/- 0.12 vs 1.26 +/- 0.10. The use of high doses of omega-3 fatty acids (600 mg EPA and 400 mg DHA per kg of animal weight per day coming through fish oil) did not affect the activity of ALT and GGT, but increased AST serum activity (0.47 +/- 0.04 micromoles/min per mg protein) and the de Ritis ratio (2.53 +/- 0.23). The diet deprived with fat increased enzyme activity of ALT, AST and GGT in rat blood serum.
9. Streaked Imaging of Ablative Richtmyer--Meshkov Growth in ICF Targets on OMEGA
Gotchev, O. V.; Goncharov, V. N.; Jaanimagi, P. A.; Knauer, J. P.; Meyerhofer, D. D.
2003-10-01
Dynamic overpressure sets the growth rate of the ablative Richtmyer--Meshkov (RM) instability and the seeds for subsequent growth of perturbations due to the Rayleigh--Taylor instability in directly driven ICF targets. It leads to temporal oscillations of the perturbed ablation front, which have been predicted analytically,(V.N. Goncharov, Phys. Rev. Lett. 82), 2091 (1999). observed in 2-D ORCHID hydrodynamic simulations, and measured experimentally.(Y. Aglitskiy et al.), Phys. Plasmas 9, 2264 (2002). These predictions were verified on OMEGA by measuring the perturbation amplitudes and frequencies directly, through face-on x-ray radiography. Experiments with a high-resolution, Ir-coated Kirkpatrick--Baez microscope, coupled to a high-current streak tube, provided a continuous record of the target areal density during shock transit, while it was dominated by the evolution of the RM instability. Planar plastic targets with variable thicknesses (30 to 60 μm) and single-mode (λ = 10 to 30 μm) ripples on the front surface were irradiated with 1.5-ns square UV laser pulses with intensities---ranging from 5 × 10^13 W/cm^2 to 4 × 10^14 W/cm^2. Results clearly indicate a phase reversal in the evolution of the target areal density perturbations, in good agreement with theory and simulation. The predicted dependence of the oscillation period on laser intensity and modulation wavelength was quantified. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.
10. Do long-chain omega-3 fatty acids protect from atopic dermatitis?
PubMed
Reese, Imke; Werfel, Thomas
2015-09-01
Long-chain polyunsaturated fatty acids are essential for human nutrition. The number of double bonds determines whether a given fatty acid is termed two, three, or x times unsaturated. Depending on the distance of the first double bond from the fatty acid's methyl group, one distinguishes omega-3 fatty acids from omega-6 fatty acids. While the use of gamma linolenic acid, a long-chain fatty acid of the omega-6 family, has proven unsuccessful in the prevention or treatment of atopic dermatitis, supplementation of long-chain omega-3 fatty acids may represent a promising approach in the prevention of allergic disorders, especially atopic dermatitis. Whether the concept of long-chain omega-3 fatty acid administration will also become established in a therapeutic setting, depends on whether the beneficial effects observed so far can be substantiated in randomized controlled intervention studies.
11. Omega-3 Fatty Acids and Primary and Secondary Prevention of Cardiovascular Disease.
PubMed
Cao, Yong; Lu, Lei; Liang, Jun; Liu, Min; Li, Xianchi; Sun, RongRong; Zheng, Yi; Zhang, Peiying
2015-05-01
The prevalence of cardiovascular disease (CVD) is increasing dramatically especially in developing countries like India. CVD is a leading cause of morbidity and mortality. There has been a growing awareness of the role of nutrients in the prevention of CVD. One specific recommendation in the battle against CVD is the increased intake of omega-3 fatty acids, which are polyunsaturated fatty acids. Studies have reported inverse associations of CVD with dietary intake of omega-3 fatty acids, suggesting that omega-3 fatty acids supplementation might exert protective effects on CVD. They exert their cardioprotective effect through multiple mechanisms. Omega-3 fatty acid therapy has shown promise as a useful tool in the primary and secondary prevention of CVD. This review briefly summarizes the effects of omega-3 fatty acids in primary and secondary prevention of CVD.
12. Numerical error in electron orbits with large. omega. sub ce. delta. t
SciTech Connect
Parker, S.E.; Birdsall, C.K.
1989-12-20
We have found that running electrostatic particle codes relatively large {omega}{sub ce}{Delta}t in some circumstances does not significantly affect the physical results. We first present results from a single particle mover finding the correct first order drifts for large {omega}{sub ce}{Delta}t. We then characterize the numerical orbit of the Boris algorithm for rotation when {omega}{sub ce}{Delta}t {much gt} 1. Next, an analysis of the guiding center motion is given showing why the first order drift is retained at large {omega}{sub ce}{Delta}t. Lastly, we present a plasma simulation of a one dimensional cross field sheath, with large and small {omega}{sub ce}{Delta}t, with very little difference in the results. 15 refs., 7 figs., 1 tab.
13. Measurements of the branching fractions of exclusive charmless B meson decays with eta(') or omega mesons.
PubMed
Aubert, B; Boutigny, D; Gaillard, J M; Hicheur, A; Karyotakis, Y; Lees, J P; Robbe, P; Tisserand, V; Palano, A; Chen, G P; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Reinertsen, P L; Stugu, B; Abbott, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Clark, A R; Gill, M S; Gritsan, A; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kluth, S; Kolomensky, Y G; Kral, J F; LeClerc, C; Levi, M E; Liu, T; Lynch, G; Meyer, A B; Momayezi, M; Oddone, P J; Perazzo, A; Pripstein, M; Roe, N A; Romosan, A; Ronan, M T; Shelkov, V G; Telnov, A V; Wenzel, W A; Bright-Thomas, P G; Harrison, T J; Hawkes, C M; Knowles, D J; O'Neale, S W; Penny, R C; Watson, A T; Watson, N K; Deppermann, T; Goetzen, K; Koch, H; Krug, J; Kunze, M; Lewandowski, B; Peters, K; Schmuecker, H; Steinke, M; Andress, J C; Barlow, N R; Bhimji, W; Chevalier, N; Clark, P J; Cottingham, W N; De Groot, N; Dyce, N; Foster, B; McFall, J D; Wallom, D; Wilson, F F; Abe, K; Hearty, C; Mattison, T S; McKenna, J A; Thiessen, D; Jolly, S; McKemey, A K; Tinslay, J; Blinov, V E; Bukin, A D; Bukin, D A; Buzykaev, A R; Golubev, V B; Ivanchenko, V N; Korol, A A; Kravchenko, E A; Onuchin, A P; Salnikov, A A; Serednyakov, S I; Skovpen, Y I; Telnov, V I; Yushkov, A N; Best, D; Lankford, A J; Mandelkern, M; McMahon, S; Stoker, D P; Ahsan, A; Arisaka, K; Buchanan, C; Chun, S; Branson, J G; MacFarlane, D B; Prell, S; Rahatlou, S; Raven, G; Sharma, V; Campagnari, C; Dahmes, B; Hart, P A; Kuznetsova, N; Levy, S L; Long, O; Lu, A; Richman, J D; Verkerke, W; Witherell, M; Yellin, S; Beringer, J; Dorfan, D E; Eisner, A M; Frey, A; Grillo, A A; Grothe, M; Heusch, C A; Johnson, R P; Kroeger, W; Lockman, W S; Pulliam, T; Sadrozinski, H; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Turri, M; Walkowiak, W; Williams, D C; Wilson, M G; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Metzler, S; Oyang, J; Porter, F C; Ryd, A; Samuel, A; Weaver, M; Yang, S; Zhu, R Y; Devmal, S; Geld, T L; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Barillari, T; Bloom, P; Dima, M O; Fahey, S; Ford, W T; Hall, T L; Johnson, D R; Nauenberg, U; Olivas, A; Park, H; Rankin, P; Roy, J; Sen, S; Smith, J G; van Hoek, W C; Wagner, D L; Blouw, J; Harton, J L; Krishnamurthy, M; Soffer, A; Toki, W H; Wilson, R J; Zhang, J; Brandt, T; Brose, J; Colberg, T; Dahlinger, G; Dickopp, M; Dubitzky, R S; Maly, E; Müller-Pfefferkorn, R; Otto, S; Schubert, K R; Schwierz, R; Spaan, B; Wilden, L; Behr, L; Bernard, D; Bonneaud, G R; Brochard, F; Cohen-Tanugi, J; Ferrag, S; Roussot, E; T'Jampens, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Anjomshoaa, A; Bernet, R; Khan, A; Muheim, F; Playfer, S; Swain, J E; Falbo, M; Borean, C; Bozzi, C; Dittongo, S; Folegani, M; Piemontese, L; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Falciai, D; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Xie, Y; Zallo, A; Bagnasco, S; Buzzo, A; Contri, R; Crosetti, G; Fabbricatore, P; Farinon, S; Lo Vetere, M; Macri, M; Monge, M R; Musenich, R; Pallavicini, M; Parodi, R; Passaggio, S; Pastore, F C; Patrignani, C; Pia, M G; Priano, C; Robutti, E; Santroni, A; Morii, M; Bartoldus, R; Dignan, T; Hamilton, R; Mallik, U; Cochran, J; Crawley, H B; Fischer, P A; Lamsa, J; Meyer, W T; Rosenberg, E I; Benkebil, M; Grosdidier, G; Hast, C; Höcker, A; Lacker, H M; LePeltier, V; Lutz, A M; Plaszczynski, S; Schune, M H; Trincaz-Duvoid, S; Valassi, A; Wormser, G; Bionta, R M; Brigljević, V; Lange, D J; Mugge, M; Shi, X; van Bibber, K; Wenaus, T J; Wright, D M; Wuest, C R; Carroll, M; Fry, J R; Gabathuler, E; Gamet, R; George, M; Kay, M; Payne, D J; Sloane, R J; Touramanis, C; Aspinwall, M L; Bowerman, D A; Dauncey, P D; Egede, U; Eschrich, I; Gunawardane, N J; Nash, J A; Sanders, P; Smith, D; Azzopardi, D E; Back, J J; Dixon, P; Harrison, P F; Potter, R J; Shorthouse, H W; Strother, P; Vidal, P B; Williams, M I; Cowan, G; George, S; Green, M G; Kurup, A; Marker, C E; McGrath, P; McMahon, T R; Ricciardi, S; Salvatore, F; Scott, I; Vaitsas, G; Brown, D; Davis, C L; Allison, J; Barlow, R J; Boyd, J T; Forti, A C; Fullwood, J; Jackson, F; Lafferty, G D; Savvas, N; Simopoulos, E T; Weatherall, J H; Farbin, A; Jawahery, A; Lillard, V; Olsen, J; Roberts, D A; Schieck, J R; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Moore, T B; Staengle, H; Willocq, S; Brau, B; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Milek, M; Patel, P M; Trischuk, J; Lanni, F; Palombo, F; Bauer, J M; Booke, M; Cremaldi, L; Eschenburg, V; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Martin, J P; Nief, J Y; Seitz, R; Taras, P; Zacek, V; Nicholson, H; Sutton, C S; Cartaro, C; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Paolucci, P; Piccolo, D; Sciacca, C; LoSecco, J M; Alsmiller, J R; Gabriel, T A; Handler, T; Brau, J; Frey, R; Iwasaki, M; Sinev, N B; Strom, D; Colecchia, F; Dal Corso, F; Dorigo, A; Galeazzi, F; Margoni, M; Michelon, G; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Torassa, E; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; De la Vaissière, C; Del Buono, L; Hamon, O; Le Diberder, F; Leruste, P; Lory, J; Roos, L; Stark, J; Versillé, S; Manfredi, P F; Re, V; Speziali, V; Frank, E D; Gladney, L; Guo, Q H; Panetta, J H; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Simi, G; Triggiani, G; Walsh, J; Haire, M; Judd, D; Paick, K; Turnbull, L; Wagoner, D E; Albert, J; Bula, C; Elmer, P; Lu, C; McDonald, K T; Miftakov, V; Schaffner, S F; Smith, A J; Tumanov, A; Varnes, E W; Cavoto, G; del Re, D; Faccini, R; Ferrarotto, F; Ferroni, F; Fratini, K; Lamanna, E; Leonardi, E; Mazzoni, M A; Morganti, S; Piredda, G; Safai Tehrani, F; Serra, M; Voena, C; Christ, S; Waldi, R; Adye, T; Franek, B; Geddes, N I; Gopal, G P; Xella, S M; Aleksan, R; De Domenico, G; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, W; Langer, M; London, G W; Mayer, B; Serfass, B; Vasseur, G; Yeche, C; Zito, M; Copty, N; Purohit, M V; Singh, H; Yumiceva, F X; Adam, I; Anthony, P L; Aston, D; Baird, K; Bloom, E; Boyarski, A M; Bulos, F; Calderini, G; Claus, R; Convery, M R; Coupal, D P; Coward, D H; Dorfan, J; Doser, M; Dunwoodie, W; Field, R C; Glanzman, T; Godfrey, G L; Gowdy, S J; Grosso, P; Himel, T; Huffner, M E; Innes, W R; Jessop, C P; Kelsey, M H; Kim, P; Kocain, M L; Langenegger, U; Leith, D W; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Menke, S; Messner, R; Moffeit, K C; Mount, R; Muller, D R; O'Grady, C P; Perl, M; Petrak, S; Quinn, H; Ratcliff, B N; Robertson, S H; Rochester, L S; Roodman, A; Schietinger, T; Schindler, R H; Schwiening, J; Serbo, V V; Snyder, A; Soha, A; Spanier, S M; Stelzer, J; Su, D; Sullivan, M K; Tanaka, H A; Va'vra, J; Wagner, S R; Weinstein, A J; Wisniewski, W J; Wright, D H; Young, C C; Burchat, P R; Cheng, C H; Kirkby, D; Meyer, T I; Roat, C; Henderson, R; Bugg, W; Cohn, H; Weidemann, A W; Izen, J M; Kitayama, I; Lou, X C; Turcotte, M; Bianchi, F; Bona, M; Di Girolamo, B; Gamba, D; Smol, A; Zanin, D; Lanceri, L; Pompili, A; Vaugnin, G; Panvini, R S; Brown, C M; De Silva, A; Kowalewski, R; Roney, J M; Band, H R; Charles, E; Dasu, S; Di Lodovico, F; Eichenbaum, A M; Hu, H; Johnson, J R; Liu, R; Nielsen, J; Pan, Y; Prepost, R; Scott, I J; Sekula, S J; von Wimmersperg-Toeller, J H; Wu, S L; Yu, Z; Zobernig, H; Kordich, T M; Neal, H
2001-11-26
We present the results of searches for B decays to charmless two-body final states containing eta(') or omega mesons, based on 20.7 fb(-1) of data collected with the BABAR detector. We find the branching fractions Beta(B(+)-->eta(')K(+)) = (70+/-8+/-5) x 10(-6), Beta(B(0)-->eta(')K(0)) = (42(+13)(-11) +/- 4) x 10(-6), and Beta(B(+)-->omega pi(+)) = (6.6(+2.1)(-1.8) +/- 0.7) x 10(-6), where the first error quoted is statistical and the second is systematic. We give measurements of four additional modes for which the 90% confidence level upper limits are Beta(B(+)-->eta(')pi(+)) < 12 x 10(-6), Beta(B(+)-->omega K(+)) < 4 x 10(-6), Beta(B(0)-->omega K(0)) < 13 x 10(-6), and Beta(B(0)-->omega pi(0)) < 3 x 10(-6).
14. Simulation analysis of a microcomputer-based, low-cost Omega navigation system
NASA Technical Reports Server (NTRS)
Lilley, R. W.; Salter, R. J., Jr.
1976-01-01
The current status of research on a proposed micro-computer-based, low-cost Omega Navigation System (ONS) is described. The design approach emphasizes minimum hardware, maximum software, and the use of a low-cost, commercially-available microcomputer. Currently under investigation is the implementation of a low-cost navigation processor and its interface with an omega sensor to complete the hardware-based ONS. Sensor processor functions are simulated to determine how many of the sensor processor functions can be handled by innovative software. An input data base of live Omega ground and flight test data was created. The Omega sensor and microcomputer interface modules used to collect the data are functionally described. Automatic synchronization to the Omega transmission pattern is described as an example of the algorithms developed using this data base.
15. Flight test and evaluation of Omega navigation in a general aviation aircraft. Volume 1: Technical
NASA Technical Reports Server (NTRS)
Howell, J. D.; Hoffman, W. C.; Hwoschinsky, P. V.; Wischmeyer, C. E.
1975-01-01
A low cost flight research program was conducted to evaluate the performance of differential Omega navigation in a general aviation aircraft. The flight program consisted of two distinct parts corresponding to the two major objectives of the study. The Wallops Flight Program was conducted to obtain Omega signal and phase data in the Wallops Flight Center vicinity to provide preliminary technical information and experience in preparation for a comprehensive NASA/FAA flight test program of an experimental differential Omega system. The Northeast Corridor Flight Program was conducted to examine Omega operational suitability and performance on low altitude area navigation (RNAV) routes for city-center to city-center VTOL commercial operations in the Boston-New York-Washington corridor. The development, execution and conclusions of the flight research program are discribed. The results of the study provide both quantitative and qualitative data on the Omega Navigation System under actual operating conditions.
16. People with schizophrenia and depression have a low omega-3 index.
PubMed
Parletta, Natalie; Zarnowiecki, Dorota; Cho, Jihyun; Wilson, Amy; Procter, Nicholas; Gordon, Andrea; Bogomolova, Svetlana; O'Dea, Kerin; Strachan, John; Ballestrin, Matt; Champion, Andrew; Meyer, Barbara J
2016-07-01
Cardiovascular disease (CVD) is higher in people with mental illness and is associated with a 30 year higher mortality rate in this population. Erythrocyte docosahexaenoic acid (DHA) plus eicosapentaenoic acid (EPA) (omega-3 index)≤4% is a marker for increased mortality risk from CVD while >8% is protective. Omega-3 polyunsaturated fatty acids are also important for brain function and may ameliorate symptoms of mental illness. We investigated the erythrocyte omega-3 index in people with mental illness. One hundred and thirty adults aged 18-65 years (32.6% male) with schizophrenia (n=14) and depression (n=116) provided blood samples and completed physiological assessments and questionnaires. Both populations had risk factors for metabolic syndrome and CVD. The average omega-3 index was 3.95% (SD=1.06), compared to an estimated 5% in the Australian population. These data indicate an unfavourable omega-3 profile in people with mental illness that could contribute to higher CVD risk.
17. Encapsulation of vegetable oils as source of omega-3 fatty acids for enriched functional foods.
PubMed
Ruiz Ruiz, Jorge Carlos; Ortiz Vazquez, Elizabeth De La Luz; Segura Campos, Maira Rubi
2017-05-03
Polyunsaturated omega-3 fatty acids (PUFAs), a functional component present in vegetable oils, are generally recognized as being beneficial to health. Omega-3 PUFAs are rich in double bonds and unsaturated in nature; this attribute makes them highly susceptible to lipid oxidation and unfit for incorporation into long shelf life foods. The microencapsulation of oils in a polymeric matrix (mainly polysaccharides) offers the possibility of controlled release of the lipophilic functional ingredient and can be useful for the supplementation of foods with PUFAs. The present paper provides a literature review of different vegetable sources of omega-3 fatty acids, the functional effects of omega-3 fatty acids, different microencapsulation methods that can possibly be used for the encapsulation of oils, the properties of vegetable oil microcapsules, the effect of encapsulation on oxidation stability and fatty acid composition of vegetable oils, and the incorporation of long-chain omega-3 polyunsaturated fatty acids in foods.
18. Omega-3 fatty acids: a comprehensive review of their role in health and disease.
PubMed
Yashodhara, B M; Umakanth, S; Pappachan, J M; Bhat, S K; Kamath, R; Choo, B H
2009-02-01
Omega-3 fatty acids (omega-3 FAs) are essential fatty acids with diverse biological effects in human health and disease. Reduced cardiovascular morbidity and mortality is a well-established benefit of their intake. Dietary supplementation may also benefit patients with dyslipidaemia, atherosclerosis, hypertension, diabetes mellitus, metabolic syndrome, obesity, inflammatory diseases, neurological/ neuropsychiatric disorders and eye diseases. Consumption of omega-3 FAs during pregnancy reduces the risk of premature birth and improves intellectual development of the fetus. Fish, fish oils and some vegetable oils are rich sources of omega-3 FAs. According to the UK Scientific Advisory Committee on Nutrition guidelines (2004), a healthy adult should consume a minimum of two portions of fish a week to obtain the health benefit. This review outlines the health implications, dietary sources, deficiency states and recommended allowances of omega-3 FAs in relation to human nutrition.
19. Does lower Omega allow a resolution of the large-scale structure problem?
NASA Technical Reports Server (NTRS)
Silk, Joseph; Vittorio, Nicola
1987-01-01
The intermediate angular scale anisotropy of the cosmic microwave background, peculiar velocities, density correlations, and mass fluctuations for both neutrino and baryon-dominated universes with Omega less than one are evaluated. The large coherence length associated with a low-Omega, hot dark matter-dominated universe provides substantial density fluctuations on scales up to 100 Mpc: there is a range of acceptable models that are capable of producing large voids and superclusters of galaxies and the clustering of galaxy clusters, with Omega roughly 0.3, without violating any observational constraint. Low-Omega, cold dark matter-dominated cosmologies are also examined. All of these models may be reconciled with the inflationary requirement of a flat universe by introducing a cosmological constant 1-Omega.
20. Omega-3 Fatty Acids in Modern Parenteral Nutrition: A Review of the Current Evidence.
PubMed
Klek, Stanislaw
2016-03-07
Intravenous lipid emulsions are an essential component of parenteral nutrition regimens. Originally employed as an efficient non-glucose energy source to reduce the adverse effects of high glucose intake and provide essential fatty acids, lipid emulsions have assumed a larger therapeutic role due to research demonstrating the effects of omega-3 and omega-6 polyunsaturated fatty acids (PUFA) on key metabolic functions, including inflammatory and immune response, coagulation, and cell signaling. Indeed, emerging evidence suggests that the effects of omega-3 PUFA on inflammation and immune response result in meaningful therapeutic benefits in surgical, cancer, and critically ill patients as well as patients requiring long-term parenteral nutrition. The present review provides an overview of the mechanisms of action through which omega-3 and omega-6 PUFA modulate the immune-inflammatory response and summarizes the current body of evidence regarding the clinical and pharmacoeconomic benefits of intravenous n-3 fatty acid-containing lipid emulsions in patients requiring parenteral nutrition.
1. The Complexity and Challenges of the ICD-9-CM to ICD-10-CM Transition in Emergency Departments
PubMed Central
Krive, Jacob; Patel, Mahatkumar; Gehm, Lisa; Mackey, Mark; Kulstad, Erik; Li, Jianrong ‘John’; Lussier, Yves A.; Boyd, Andrew D.
2015-01-01
Beginning October 2015, the Center for Medicare and Medicaid Services (CMS) will require medical providers to utilize the vastly expanded ICD-10-CM system. Despite wide availability of information and mapping tools for the next generation of the ICD classification system, some of the challenges associated with transition from ICD-9-CM to ICD-10-CM are not well understood. To quantify the challenges faced by emergency physicians, we analyzed a subset of a 2010 Illinois Medicaid database of emergency department ICD-9-CM codes, seeking to determine the accuracy of existing mapping tools in order to better prepare emergency physicians for the change to the expanded ICD-10-CM system. We found that 27% of 1,830 codes represented convoluted multidirectional mappings. We then analyzed the convoluted transitions and found 8% of total visit encounters (23% of the convoluted transitions) were clinically incorrect. The ambiguity and inaccuracy of these mappings may impact the work flow associated with the translation process and affect the potential mapping between ICD codes and CPT (Current Procedural Codes) codes, which determine physician reimbursement. PMID:25863652
2. Observation of the Omega(b)- Baryon and Measurement of the Properties of the Xi(b)- and Omega(b)- Baryons
SciTech Connect
Aaltonen, T.; Adelman, Jahred A.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, Jaroslav; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.
2009-05-01
The authors report the observation of the bottom, doubly-strange baryon {Omega}{sub b}{sup -} through the decay chain {Omega}{sub b}{sup -} {yields} J/{psi}{Omega}{sup -}, where J/{psi} {yields} {mu}{sup +} {mu}{sup -}, {Omega}{sup -} {yields} {Lambda}K{sup -}, and {Lambda} {yields} p {pi}{sup -}, using 4.2 fb{sup -1} of data from p{bar p} collisions at {radical}s = 1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 x 10{sup -8}, or 5.5 Gaussian standard deviations. The {Omega}{sub b}{sup -} mass is measured to be 6054.4 {+-} 6.8(stat.) {+-} 0.9(syst.) MeV/c{sup 2}. The lifetime of the {Omega}{sub b}{sup -} baryon is measured to be 1.13{sub -0.40}{sup +0.53}(stat.) {+-} 0.02(syst.) ps. In addition, for the {Xi}{sub b}{sup -} baryon they measure a mass of 5790.9 {+-} 2.6(stat.) {+-} 0.8(syst.) MeV/c{sup 2} and a lifetime of 1.56{sub -0.25}{sup +0.27}(stat.) {+-} 0.02(syst.) ps.
3. Large, omega-3 rich, pelagic diatoms under Arctic sea ice: sources and implications for food webs.
PubMed
Duerksen, Steven W; Thiemann, Gregory W; Budge, Suzanne M; Poulin, Michel; Niemi, Andrea; Michel, Christine
2014-01-01
Pelagic primary production in Arctic seas has traditionally been viewed as biologically insignificant until after the ice breakup. There is growing evidence however, that under-ice blooms of pelagic phytoplankton may be a recurrent occurrence. During the springs of 2011 and 2012, we found substantial numbers (201-5713 cells m-3) of the large centric diatom (diameter >250 µm) Coscinodiscus centralis under the sea ice in the Canadian Arctic Archipelago near Resolute Bay, Nunavut. The highest numbers of these pelagic diatoms were observed in Barrow Strait. Spatial patterns of fatty acid profiles and stable isotopes indicated two source populations for C. centralis: a western origin with low light conditions and high nutrients, and a northern origin with lower nutrient levels and higher irradiances. Fatty acid analysis revealed that pelagic diatoms had significantly higher levels of polyunsaturated fatty acids (mean ± SD: 50.3 ± 8.9%) compared to ice-associated producers (30.6 ± 10.3%) in our study area. In particular, C. centralis had significantly greater proportions of the long chain omega-3 fatty acid, eicosapentaenoic acid (EPA), than ice algae (24.4 ± 5.1% versus 13.7 ± 5.1%, respectively). Thus, C. centralis represented a significantly higher quality food source for local herbivores than ice algae, although feeding experiments did not show clear evidence of copepod grazing on C. centralis. Our results suggest that C. centralis are able to initiate growth under pack ice in this area and provide further evidence that biological productivity in ice-covered seas may be substantially higher than previously recognized.
4. Large, Omega-3 Rich, Pelagic Diatoms under Arctic Sea Ice: Sources and Implications for Food Webs
PubMed Central
Duerksen, Steven W.; Thiemann, Gregory W.; Budge, Suzanne M.; Poulin, Michel; Niemi, Andrea; Michel, Christine
2014-01-01
Pelagic primary production in Arctic seas has traditionally been viewed as biologically insignificant until after the ice breakup. There is growing evidence however, that under-ice blooms of pelagic phytoplankton may be a recurrent occurrence. During the springs of 2011 and 2012, we found substantial numbers (201–5713 cells m−3) of the large centric diatom (diameter >250 µm) Coscinodiscus centralis under the sea ice in the Canadian Arctic Archipelago near Resolute Bay, Nunavut. The highest numbers of these pelagic diatoms were observed in Barrow Strait. Spatial patterns of fatty acid profiles and stable isotopes indicated two source populations for C. centralis: a western origin with low light conditions and high nutrients, and a northern origin with lower nutrient levels and higher irradiances. Fatty acid analysis revealed that pelagic diatoms had significantly higher levels of polyunsaturated fatty acids (mean ± SD: 50.3±8.9%) compared to ice-associated producers (30.6±10.3%) in our study area. In particular, C. centralis had significantly greater proportions of the long chain omega-3 fatty acid, eicosapentaenoic acid (EPA), than ice algae (24.4±5.1% versus 13.7±5.1%, respectively). Thus, C. centralis represented a significantly higher quality food source for local herbivores than ice algae, although feeding experiments did not show clear evidence of copepod grazing on C. centralis. Our results suggest that C. centralis are able to initiate growth under pack ice in this area and provide further evidence that biological productivity in ice-covered seas may be substantially higher than previously recognized. PMID:25473949
5. Associations Between Whole Blood and Dietary Omega-3 Polyunsaturated Fatty Acid Levels in Collegiate Athletes.
PubMed
Wilson, Patrick B; Madrigal, Leilani A
2016-12-01
Omega-3 polyunsaturated fatty acids (PUFAs) have important physiological functions and may offer select benefits for athletic performance and recovery. The purpose of this investigation was to assess dietary and whole blood omega-3 PUFAs among collegiate athletes. In addition, a brief questionnaire was evaluated as a valid tool for quantifying omega-3 PUFA intake. Fifty-eight athletes (9 males, 49 females) completed a 21-item questionnaire developed to assess omega-3 PUFA intake and provided dried whole blood samples to quantify α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and the HS-Omega-3 Index. Geometric means (95% confidence intervals) for the HS-Omega-3 Index were 4.79% (4.37-5.25%) and 4.75% (4.50-5.01%) for males and females, respectively. Median dietary intakes of ALA, EPA, and DHA were all below 100 mg. Among females, several dietary omega-3 PUFA variables were positively associated with whole blood EPA, with total EPA (rho = 0.67, p < .001) and total DHA (rho = 0.69, p < .001) intakes showing the strongest correlations. Whole blood DHA among females showed positive associations with dietary intakes, with total EPA (rho = 0.62, p < .001) and total DHA (rho = 0.64, p < .001) intakes demonstrating the strongest correlations. The HS-Omega-3 Index in females was positively correlated with all dietary variables except ALA. Among males, the only significant correlation was between food and whole blood EPA (rho = 0.83, p < .01). Collegiate athletes had relatively low intakes of omega-3 PUFAs. A 21-item questionnaire may be useful for screening female athletes for poor omega-3 PUFA status.
6. Recent Advances in Omega-3: Health Benefits, Sources, Products and Bioavailability
PubMed Central
Nichols, Peter D.; McManus, Alexandra; Krail, Kevin; Sinclair, Andrew J.; Miller, Matt
2014-01-01
The joint symposium of The Omega-3 Centre and the Australasian Section American Oil Chemists Society; Recent Advances in Omega-3: Health Benefits, Sources, Products and Bioavailability, was held November 7, 2013 in Newcastle, NSW, Australia. Over 115 attendees received new information on a range of health benefits, aquaculture as a sustainable source of supply, and current and potential new and novel sources of these essential omega-3 long-chain (LC, ≥C20) polyunsaturated fatty acid nutrients (also termed LC omega-3). The theme of “Food versus Fuel” was an inspired way to present a vast array of emerging and ground breaking Omega-3 research that has application across many disciplines. Eleven papers submitted following from the Omega-3 Symposium are published in this Special Issue volume, with topics covered including: an update on the use of the Omega-3 Index (O3I), the effects of dosage and concurrent intake of vitamins/minerals on omega-3 incorporation into red blood cells, the possible use of the O3I as a measure of risk for adiposity, the need for and progress with new land plant sources of docosahexaenoic acid (DHA, 22:6ω3), the current status of farmed Australian and New Zealand fish, and also supplements, in terms of their LC omega-3 and persistent organic pollutants (POP) content, progress with cheap carbon sources in the culture of DHA-producing single cell organisms, a detailed examination of the lipids of the New Zealand Greenshell mussel, and a pilot investigation of the purification of New Zealand hoki liver oil by short path distillation. The selection of papers in this Special Issue collectively highlights a range of forward looking and also new and including positive scientific outcomes occurring in the omega-3 field. PMID:25255830
7. Recent advances in omega-3: Health Benefits, Sources, Products and Bioavailability.
PubMed
Nichols, Peter D; McManus, Alexandra; Krail, Kevin; Sinclair, Andrew J; Miller, Matt
2014-09-16
The joint symposium of The Omega-3 Centre and the Australasian Section American Oil Chemists Society; Recent Advances in Omega-3: Health Benefits, Sources, Products and Bioavailability, was held November 7, 2013 in Newcastle, NSW, Australia. Over 115 attendees received new information on a range of health benefits, aquaculture as a sustainable source of supply, and current and potential new and novel sources of these essential omega-3 long-chain (LC, ≥ C20) polyunsaturated fatty acid nutrients (also termed LC omega-3). The theme of "Food versus Fuel" was an inspired way to present a vast array of emerging and ground breaking Omega-3 research that has application across many disciplines. Eleven papers submitted following from the Omega-3 Symposium are published in this Special Issue volume, with topics covered including: an update on the use of the Omega-3 Index (O3I), the effects of dosage and concurrent intake of vitamins/minerals on omega-3 incorporation into red blood cells, the possible use of the O3I as a measure of risk for adiposity, the need for and progress with new land plant sources of docosahexaenoic acid (DHA, 22:6ω3), the current status of farmed Australian and New Zealand fish, and also supplements, in terms of their LC omega-3 and persistent organic pollutants (POP) content, progress with cheap carbon sources in the culture of DHA-producing single cell organisms, a detailed examination of the lipids of the New Zealand Greenshell mussel, and a pilot investigation of the purification of New Zealand hoki liver oil by short path distillation. The selection of papers in this Special Issue collectively highlights a range of forward looking and also new and including positive scientific outcomes occurring in the omega-3 field.
8. Sayama CM2 Chondrite: Fresh but Heavily Altered
NASA Technical Reports Server (NTRS)
Takaoka, N.; Nakamura, T.; Noguchi, T.; Tonui, E.; Gounelle, M.; Zolensky, M. E.; Ebisawa, N.; Osawa, T.; Okazaki, R.; Nagao, K.; Yoneda, S.
2001-01-01
Noble gas composition and mineralogy of Sayama meteorite, that fell in Japan and recently identified as a CM2 chondrite, revealed many unique features, indicating that it experienced extensive aqueous alteration under highly oxidized condition compared with typical CMs. Additional information is contained in the original extended abstract.
9. Electronic and magnetic properties of Am and Cm
SciTech Connect
Edelstein, N.
1985-02-01
A review of the present status of the analyses of the optical spectra of Am and Cm in various oxidation states is given. From these analyses, the magnetic properties of the ground states of these ions can be determined. These predicted values are compared with the various magnetic measurements available.
10. Organic Matter Inclusions in CM2 Chondrite Murchison
Peeters, Z.; Liebig, B.; Lee, T.
2015-07-01
Large (~10 μm) inclusions of pure organic carbon exist in carbonaceous chondrites. We extracted organic inclusions from Murchison, a CM2, and analyzed the sections using XANES, TEM, and nanoSIMS. The results are compared to previous results of CRs.
11. Retrofit and acceptance test of 30-cm ion thrusters
NASA Technical Reports Server (NTRS)
Poeschel, R. L.
1981-01-01
Six 30 cm mercury thrusters were modified to the J-series design and evaluated using standardized test procedures. The thruster performance meets the design objectives (lifetime objective requires verification), and documentation (drawings, etc.) for the design is completed and upgraded. The retrofit modifications are described and the test data for the modifications are presented and discussed.
12. Search for Cm-248 in the early solar system
NASA Technical Reports Server (NTRS)
Lavielle, B.; Marti, K.; Pellas, P.; Perron, C.
1992-01-01
Possible evidence for the presence of Cm-248 in the early solar system was reported from fission gas studies (Rao and Gopalan, 1973) and recently from studies of very high nuclear track densities (not less than 5 x 10 exp 8/sq cm) in the merrillite of the H4 chondrite Forest Vale (F.V.) (Pellas et al., 1987). We report here an analysis of the isotopic abundances of xenon in F.V. phosphates and results of track studies in phosphate/pyroxene contacts. The fission xenon isotopic signature clearly identifies Pu-244 as the extinct progenitor. We calculate an upper limit Cm-248/Pu-244 to be less than 0.0015 at the beginning of Xe retention in F.V. phosphates. This corresponds to an upper limit of the ratio Cm-248/U-235 of not greater than 5 x 10 exp -5 further constraining the evidence for any late addition of freshly synthesized actinide elements just prior to solar system formation. The fission track density observed after annealing the phosphates at 290C (1 hr, which essentially erases spallation recoil tracks) is also in agreement with the Pu-244 abundance inferred from fission Xe. The spallation recoil tracks produced during the 76 Ma cosmic-ray exposure account for the very high track density in merrillites.
13. Adaptation of California Measure of Mental Motivation-CM3
ERIC Educational Resources Information Center
Özdemir, Hasan Fehmi; Demirtasli, Nükhet Çikrikçi
2015-01-01
Education without doubt, plays a vital role for individuals to gain the essential personal traits of the 21st century, also known as "knowledge age". One of the most important skills among these fundamental qualities which the individuals should be equipped with is critical thinking. California Measure of Mental Motivation-CM3 was…
14. Case study: developing product lines using ICD-9-CM codes.
PubMed
Benz, P D; Burnham, J
1985-12-01
In this marketing case study, Thomas Jefferson University Hospital used a product line approach to maximize the use of its resources. The method used, based on ICD-9-CM codes, fulfilled the demands of increased efficiency by encouraging customer-oriented thinking, enhancing communication with physicians and patients, and helping the institution to compete more effectively.
15. Oxygen isotope constraints on the alteration temperatures of CM chondrites
Verdier-Paoletti, Maximilien J.; Marrocchi, Yves; Avice, Guillaume; Roskosz, Mathieu; Gurenko, Andrey; Gounelle, Matthieu
2017-01-01
We report a systematic oxygen isotopic survey of Ca-carbonates in nine different CM chondrites characterized by different degrees of alteration, from the least altered known to date (Paris, 2.7-2.8) to the most altered (ALH 88045, CM1). Our data define a continuous trend that crosses the Terrestrial Fractionation Line (TFL), with a general relationship that is indistinguishable within errors from the trend defined by both matrix phyllosilicates and bulk O-isotopic compositions of CM chondrites. This bulk-matrix-carbonate (BMC) trend does not correspond to a mass-dependent fractionation (i.e., slope 0.52) as it would be expected during fluid circulation along a temperature gradient. It is instead a direct proxy of the degree of O-isotopic equilibration between 17,18O-rich fluids and 16O-rich anhydrous minerals. Our O-isotopic survey revealed that, for a given CM, no carbonate is in O-isotopic equilibrium with its respective surrounding matrix. This precludes direct calculation of the temperature of carbonate precipitation. However, the O-isotopic compositions of alteration water in different CMs (inferred from isotopic mass-balance calculation and direct measurements) define another trend (CMW for CM Water), parallel to BMC but with a different intercept. The distance between the BMC and CMW trends is directly related to the temperature of CM alteration and corresponds to average carbonates and serpentine formation temperatures of 110 °C and 75 °C, respectively. However, carbonate O-isotopic variations around the BMC trend indicate that they formed at various temperatures ranging between 50 and 300 °C, with 50% of the carbonates studied here showing precipitation temperature higher than 100 °C. The average Δ17O and the average carbonate precipitation temperature per chondrite are correlated, revealing that all CMs underwent similar maximum temperature peaks, but that altered CMs experienced protracted carbonate precipitation event(s) at lower temperatures than
16. 40 CFR 721.10121 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Poly , .alpha.-methyl-.omega.-(4... Specific Chemical Substances § 721.10121 Poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched. (a... poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched (PMN P-05-766; CAS No. 858944-25-9)...
17. 40 CFR 721.10121 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Poly , .alpha.-methyl-.omega.-(4... Specific Chemical Substances § 721.10121 Poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched. (a... poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched (PMN P-05-766; CAS No. 858944-25-9)...
18. 40 CFR 721.10121 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Poly , .alpha.-methyl-.omega.-(4... Specific Chemical Substances § 721.10121 Poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched. (a... poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched (PMN P-05-766; CAS No. 858944-25-9)...
19. 40 CFR 721.10121 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Poly , .alpha.-methyl-.omega.-(4... Specific Chemical Substances § 721.10121 Poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched. (a... poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched (PMN P-05-766; CAS No. 858944-25-9)...
20. 40 CFR 721.10121 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Poly , .alpha.-methyl-.omega.-(4... Specific Chemical Substances § 721.10121 Poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched. (a... poly , .alpha.-methyl-.omega.-(4-nonylphenoxy)-, branched (PMN P-05-766; CAS No. 858944-25-9)... | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6507299542427063, "perplexity": 13415.589567339757}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187822625.57/warc/CC-MAIN-20171017234801-20171018014801-00522.warc.gz"} |
http://mathhelpforum.com/advanced-math-topics/214536-definition-limit-sequence.html | # Math Help - Definition of a limit of a sequence
1. ## Definition of a limit of a sequence
Hi all,
Can anyone help me to understand the definition of a limit of a sequence. In notes and when reading about it on the internet, I always find for every ε > 0 ∃ n such that for every n ≥ N, mod(An - L) < ε.
My biggest problem is picturing this. I understand that epsilon is a value very close to the limit of the sequence but I don't understand how this all relates together to allow us to show that a sequence converges to its limit e.g. 1/n^1/2 -> 0.
Anybody able to explain this?
Thanks guys
2. ## Re: Definition of a limit of a sequence
Let's take your example of the sequence $a_n = \frac{1}{\sqrt{n}}$
The goal is to find an equation for N dependent on epsilon such that for $n \geq N$ $|a_n-L| < \epsilon$ If $L=0$, then
$|a_n-L| = |\frac{1}{\sqrt{n}}| = \frac{1}{\sqrt{n}} < \epsilon \iff n > \frac{1}{{\epsilon}^2} = N}$
so no matter how small epsilon (the interval) gets, we can always find a natural number $n \geq N$ such that a point $a_n$ is in that interval. As epsilon goes to 0, the difference between the points $a_n$ and $L$ becomes sufficiently small | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 9, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9743648767471313, "perplexity": 165.05851968160113}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1408500835844.19/warc/CC-MAIN-20140820021355-00216-ip-10-180-136-8.ec2.internal.warc.gz"} |
https://planetmath.org/LaguerrePolynomial | # Laguerre polynomial
## 1 Definition
The Laguerre polynomials are orthogonal polynomials with respect to the weighting function $e^{-x}$ on the half-line $[0,\infty)$. They are denoted by the letter “$L$” with the order as subscript and are normalized by the condition that the coefficient of the highest order term of $L_{n}$ is $(-1)^{n}/n!$.
The first few Laguerre poynomials are as follows:
$\displaystyle L_{0}(x)$ $\displaystyle=1$ $\displaystyle L_{1}(x)$ $\displaystyle=-x+1$ $\displaystyle L_{2}(x)$ $\displaystyle=\frac{1}{2}x^{2}-2x+1$ $\displaystyle L_{3}(x)$ $\displaystyle=-\frac{1}{6}x^{3}+\frac{3}{2}x^{2}-3x+1$
A generalization is given by the associated Laguerre polynomials which depends on a parameter (traditionally denoted “$\alpha$”). As it turns out, they are polynomials of the argument $\alpha$ as as well, so they are polynomials of two variables. They are defined over the same interval with the same normalization condition, but the weight function is generalized to $x^{\alpha}e^{-x}$. They are notated by including the parameter as a parenthesized superscript (not all authors use the parentheses).
The ordinary Laguerre polynomials are the special case of the generalized Laguerre polynomials when the parameter goes to zero. When some result holds for generalized Laguerre polynomials which is not more complicated than that for ordinary Laguerre polynomials, we shall only provide the more general result and leave it to the reader to send the parameter to zero to recover the more specific result.
The first few generalized Laguerre polynomials are as follows:
$\displaystyle L_{0}^{(\alpha)}(x)$ $\displaystyle=1$ $\displaystyle L_{0}^{(\alpha)}(x)$ $\displaystyle=-x+\alpha+1$ $\displaystyle L_{0}^{(\alpha)}(x)$ $\displaystyle=\frac{1}{2}x^{2}-(\alpha+2)x+\frac{1}{2}(\alpha+2)(\alpha+1)$ $\displaystyle L_{0}^{(\alpha)}(x)$ $\displaystyle=-\frac{1}{6}x^{3}+\frac{1}{2}(\alpha+3)x^{2}-\frac{1}{2}(\alpha+% 2)(\alpha+3)x+\frac{1}{6}(\alpha+1)(\alpha+2)(\alpha+3)$
## 2 Formulae for these polynomials
The Laguerre polynomials may be exhibited explicitly as a sum in terms of factorials, which may also be written using binomial coefficients:
$L_{n}(x)=\sum_{k=0}^{n}{n!\over(k!)^{2}(n-k)!}(-x)^{k}=\sum_{k=0}^{n}{n\choose k% }{(-x)^{k}\over k!}$
The generalization may be expressed in terms of gamma functions or falling factorials:
$L_{n}^{(\alpha)}=\sum_{k=0}^{n}{\Gamma(n+\alpha+1)\over\Gamma(k+\alpha+1)}{(-x% )^{k}\over k!(n-k)!}=\sum_{k=0}^{n}{(n+\alpha)^{\underline{n-k}}\over k!(n-k)!% }(-x)^{k}$
They can be computed from a Rodrigues formula:
$L_{n}^{(\alpha)}(x)=\frac{1}{n!}x^{-\alpha}e^{x}\frac{d^{n}}{dx^{n}}\left(e^{-% x}x^{n+\alpha}\right)$
They have several integral representations. They can be expressed in terms of a countour integral
$L_{n}(x)=\frac{1}{2\pi i}\oint\frac{e^{-\frac{xt}{1-t}}}{(1-t)t^{n+1}}\,% \mathit{dt},$
where the origin is enclosed by the contour, but not $z=1$.
## 3 Equations they satisfy
The Laguerre polynomials satisfy the orthogonality relation
$\int_{0}^{\infty}e^{-x}x^{\alpha}L_{n}^{(\alpha)}(x)L_{m}^{(\alpha)}(x)\,dx=% \frac{(n+\alpha)!}{n!}\delta_{nm}.$
The Laguerre polynomials satisfy the differential equation
$x\frac{d^{2}}{dx^{2}}L_{n}^{(\alpha)}(x)+(\alpha+1-x)\frac{d}{dx}L_{n}^{(% \alpha)}(x)+(n-\alpha)L_{n}^{(\alpha)}(x)=0$
This equation arises in many contexts such as in the quantum mechanical treatment of the hydrogen atom.
Title Laguerre polynomial LaguerrePolynomial 2013-03-22 12:30:56 2013-03-22 12:30:56 rspuzio (6075) rspuzio (6075) 22 rspuzio (6075) Definition msc 26C99 HermitePolynomials OrthogonalityOfChebyshevPolynomials associated Laguerre polynomial Laguerre’s equation | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 31, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9861519932746887, "perplexity": 240.1959656615534}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585371886991.92/warc/CC-MAIN-20200410043735-20200410074235-00528.warc.gz"} |
http://mathhelpforum.com/advanced-algebra/213233-quotients-semi-groups-monoids-print.html | # Quotients of Semi-groups or Monoids?
• February 16th 2013, 06:37 PM
SlipEternal
Quotients of Semi-groups or Monoids?
Let $A$ be the set of all strictly increasing sequences of integers. Define a binary operator $+: A\times A \to A$ by $(a_n)_{n\ge 1} + (b_n)_{n\ge 1} = (a_n+b_n-n)_{n\ge 1}$. The pair $(A,+)$ is a monoid. Define a sequence of functions for $k\ge 1$, $\varphi_k:A\to A$ by $\varphi\left( (a_n)_{n\ge 1}\right) = (a_{n+k}-a_k)_{n\ge 1}$. It is easy enough to check that each function in the sequence is a homomorphism, and for each $k$, $\ker(\varphi_k)\subseteq \ker(\varphi_{k+1})$. Let $\displaystyle B=\bigcup_{k\ge 1} \ker(\varphi_k)$. Questions: Is $B$ a sub-monoid of $A$? Is there a way to "mod-out" by $B$?
Edit:
The identity element is the sequence $(n)_{n\ge 1}$. The sets, $\ker(\varphi_k)=\{(a_n)\in A\mid \forall n>k, a_{n+1}=a_n+1\}$ are all closed under addition. Does the set $B=\{(a_n)\in A\mid \exists N\in \mathbb{N} \forall n>N, a_{n+1}=a_n+1\}$? If so, it should be closed under addition, as well. I forgot to mention that $(A,+)$ is commutative. So, if "modding out" does make sense in this context, cosets would have the form $(a_n)+B$. Without inverses, I have no idea how to tell if two sequences are in the same left coset.
• February 17th 2013, 11:05 AM
SlipEternal
Re: Quotients of Semi-groups or Monoids?
From what I can gather, what I am attempting just doesn't make any sense. I am gonna try embedding the monoid into the group of all integer sequences and using relations to find subgroups. Such as $(b_n) := (a_n)-n$. Now, I am looking for all $(b_n)$ that are eventually constant. Essentially, I am looking for a way to group together sequences based on how uniform they eventually become.
• February 17th 2013, 12:31 PM
Deveno
Re: Quotients of Semi-groups or Monoids?
quotient monoids are determined by congruences, so we have to show that B induces a congruence on A (our original monoid).
that is to say we need to show that: ((an) + B) + ((bn) + B) = ((an) + (bn)) + B is well-defined.
the way you show (an) + B = (a'n) + B is to show there is a k for which:
φN((an)) = φN((a'n)) for all N ≥ k.
now if (an) + B = (a'n) + B, and (bn) + B = (b'n) + B), there is a k such that:
φN((an)) = φN((a'n)) for all N ≥ k, and a k' such that:
φN((bn)) = φN((b'n)) for all N ≥ k'.
so choose k" = max(k,k'). then for all N ≥ k":
φN((a'n) + (b'n)) = φN((a'n)) + φN((b'n)) = φN((an)) + φN((bn))
= φN((an) + (bn)), so ((an) + (bn)) + B = ((a'n) + (b'n)) + B.
more formally, what we have done is defined a relation ~ by: (an) ~ (bn) iff there exists k such that φN((an)) = φN((a'n)) for all N ≥ k.
what is shown above shows that if ~ is an equivalence relation, it IS a congruence, and we can speak of A/~. verification that ~ is an equivalence is tedious, and rather unenlightening (symmetry and reflexiveness are immediate, and we can use the same "max trick" to show transitivity).
note that doing this only separates increasing sequences in terms of "how far they deviate from (n)", A/~ is still quite large. for example if (an) + B ≠ (a'n) + B, then one is more "increasingly increasing" (eventually).
• February 17th 2013, 04:27 PM
SlipEternal
Re: Quotients of Semi-groups or Monoids?
Ok, that makes a lot more sense. I was digging through information on universal algebras, and now that I see what you did, I understand what I was reading. And now I think I understand much better what I want. The kernel of the homomorphism is really not terribly useful. I think what I want is to define the relation:
$(a_n) \sim (b_n)$ if and only if there exists $i,j$ such that $\varphi_i (a_n) = \varphi_j (b_n)$.
Reflexivity and symmetry are again immediate. Now, suppose $(a_n)\sim (b_n)$ and $(b_n) \sim (c_n)$. That means there exists $i,j,i',j'$ such that $\varphi_i((a_n)) = \varphi_j((b_n))$ and $\varphi_{j'}((b_n)) = \varphi_{i'}((c_n))$. So, let $j''=\max(j,j')$. Then $\varphi_{i+j''-j}((a_n)) = \varphi_{j''}((b_n)) = \varphi_{i' + j''-j'} ((c_n))$ implies $(a_n)\sim (c_n)$, and transitivity is evident. So, now, what might the equivalence classes of $A/\mathopen{\sim}$ look like? Would it be difficult to classify sequences by which equivalence class they were in? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 32, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9504746794700623, "perplexity": 487.1867908804828}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1408500822407.51/warc/CC-MAIN-20140820021342-00441-ip-10-180-136-8.ec2.internal.warc.gz"} |
http://mathoverflow.net/questions/88619/how-to-compute-the-etale-cohomology-of-the-quotient-of-a-surface-by-a-finite-gro | # How to compute the étale cohomology of the quotient of a surface by a finite group of automorphisms ?
Let $S$ be a smooth surface defined over a finite field $K$ of char. $p$. Let $G$ be a finite group of automorphisms of $S$. Let $Z\to S/G$ be the minimal resolution of the quotient of $S$ by $G$. Suppose that the fixed point set of every elements of $G$ is defined over $K$.
Let $\ell$ be a prime, $\ell\not=p$. Is it true that $$H^{i}(Z,\mathbb Q_\ell) \simeq H^{i}(S,\mathbb Q_\ell)^G$$ for $i=1,3$ and $$H^{2}(Z,\mathbb Q_\ell)\simeq H^{2}(S,\mathbb Q_\ell)^G+\mathbb Q_\ell C_1+\dots +\mathbb Q_\ell C_k$$where the $C_i$ are the exceptional curves of the resolution $Z\to S/G$ ?
This question is an echo of the question "Are there any known formulas about the Hodge-Deligne structure of quotients by action of groups ?" formulated in this forum 2 or 3 weeks ago.
-
Xavier,
As per your request, I'll give a partial answer on mathoverflow assuming, for simplicity, that $G$ has isolated fixed points on $S$. Let $H^i(S)$ etc. denote the $\ell$-adic cohomology of $S\otimes\bar K$. I'll ignore Tate twists. Rather than taking the minimal resolution $Z$, let me take the minimal "log" resolution, so that the exceptional divisor $C\subset Z$ has normal crossings
Let [M] = Milne, Etale Cohomology. I'm referring to the book, but the online notes should work just as well.
Let $\iota:\Sigma\subset S$ be the set of fixed points, $U=S-\Sigma$ and $V=U/G$. Then by Hochschild-Serre [M, p105] $H^i(V)= H^i(U)^G$. By Poincare duality $H^i(V)= H_c^{4-i}(V)$. From the sequence $$\ldots H_c^i(U)\to H^i(S)\to H^i(\Sigma)\ldots$$ coming from $0\to j_!\mathbb{Q}_\ell\to \mathbb{Q}_\ell\to \iota_*\mathbb{Q}_\ell\to 0$ we deduce that
$H^i(V)= H^i(U)^G=H^i(S)^G$ for $i=1,2$.
If you combine this with the Gysin sequence $$0\to H^1(Z)\to H^1(V)\to \bigoplus H^0(C_k)\to H^2(Z)\to H^2(V)$$ you should be in good shape. To get the sequence above, apply the version of the Gysin sequence on [M, p 244] to the complement of the set of double points $Z'=Z-C_{sing}$. Use the isomorphism $H^2(Z)\cong H^2(Z')$ and do a diagram chase.
-
Great, thank you very much. – Xavier Roulleau Feb 17 '12 at 15:03 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9841455817222595, "perplexity": 118.91994758902213}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-48/segments/1386164030978/warc/CC-MAIN-20131204133350-00052-ip-10-33-133-15.ec2.internal.warc.gz"} |
http://cds.cern.ch/collection/COMPASS%20Conference%20Proceedings?ln=en | # COMPASS Conference Proceedings
2017-02-25
07:55
The $t$-dependence of the pure DVCS cross section at COMPASS / Joerg, Philipp (Freiburg U.) /COMPASS Collaboration The key reactions to study the Generalised Parton Distributions are Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP). At COMPASS, these processes are investigated using a high intensity muon beam with a momentum of 160\,GeV/c and a 2.5\,m-long liquid hydrogen target. [...] arXiv:1702.06315.- SISSA, 2016-10-10 - 7 p. - Published in : PoS: DIS2016 (2016) , pp. 235 Fulltext: PDF; Preprint: PDF; External links: PoS server; 00007 COMPASS results for the t-slope parameter (\textbf{left}) and the extracted transverse size of the partonic distribution of the nucleon (\textbf{right}), compared with previous HERA measurements.; 00003 Exclusivity variables: The whole Monte Carlo estimate is shown in red while in grey only the $\pi^0$ contamination is shown. The variables $\Delta \varphi$, $\Delta p_{\bot}$ and $M_X^2$ are defined in equation \ref{eq_phi}-\ref{eq_m} while $\Delta z_{A}$ encodes a reverse vertex pointing. The blue dotted lines indicate the applied cuts.; 00006 COMPASS results for the t-slope parameter (\textbf{left}) and the extracted transverse size of the partonic distribution of the nucleon (\textbf{right}), compared with previous HERA measurements.; 00001 Exclusivity variables: The whole Monte Carlo estimate is shown in red while in grey only the $\pi^0$ contamination is shown. The variables $\Delta \varphi$, $\Delta p_{\bot}$ and $M_X^2$ are defined in equation \ref{eq_phi}-\ref{eq_m} while $\Delta z_{A}$ encodes a reverse vertex pointing. The blue dotted lines indicate the applied cuts.; 00002 Exclusivity variables: The whole Monte Carlo estimate is shown in red while in grey only the $\pi^0$ contamination is shown. The variables $\Delta \varphi$, $\Delta p_{\bot}$ and $M_X^2$ are defined in equation \ref{eq_phi}-\ref{eq_m} while $\Delta z_{A}$ encodes a reverse vertex pointing. The blue dotted lines indicate the applied cuts.; 00000 Exclusivity variables: The whole Monte Carlo estimate is shown in red while in grey only the $\pi^0$ contamination is shown. The variables $\Delta \varphi$, $\Delta p_{\bot}$ and $M_X^2$ are defined in equation \ref{eq_phi}-\ref{eq_m} while $\Delta z_{A}$ encodes a reverse vertex pointing. The blue dotted lines indicate the applied cuts.; 00005 The $t$-differential DVCS cross section as a function of $t$; 00004 Acceptance correction factors as a function of $t$, $Q^2$ and $\nu$.; Fulltext In : 24th International Workshop on Deep Inelastic Scattering and related subjects, Hamburg, Germany, 11 - 15 Apr 2016, pp.235
2017-02-25
07:55
Measurement of the exclusive ${\pi}^0$ muoproduction cross section at COMPASS / Gorzellik, Matthias (Freiburg U.) At COMPASS DVCS and DVMP processes are studied in order to probe the partonic structure of the nucleon by constraining GPD models. [...] arXiv:1702.06293. - 4 p. Preprint
2017-02-10
07:37
COMPASS measurement of the $P_T$ weighted Sivers asymmetry / Bradamante, Franco (INFN, Trieste) The SIDIS transverse spin asymmetries weighted with powers of $P_T$, the hadron transverse momentum in the $\gamma N$ reference system,have been introduced already twenty years ago and are considered quite interesting. [...] arXiv:1702.00621. - 4 p. Preprint
2016-10-08
07:48
The spectrum of light isovector mesons with $C=+1$ from the COMPASS experiment / Paul, Stephan (Munich, Tech. U.) Based on the largest event sample of diffractively produced $\pi^-\pi^-\pi^+$, obtained by a pion beam of $190~\rm{GeV/c}$ momentum, the COMPASS collaboration has performed the most advanced partial wave analysis on multi-body final states, using the isobar model. The large number of waves included in the analysis reduces truncation effects. [...] arXiv:1610.01231.- 2016 - 9 p. - Published in : JPS Conf. Proc. 13 (2017) 010018 Fulltext: PDF; External link: Preprint In : Meson-Nucleon Physics and the Structure of the Nucleon, Kyoto, Japan, 25 - 30 Jul 2016, pp.010018
2016-09-29
01:12
Photons interacting with Hadrons at COMPASS / Friedrich, Jan Michael (Technische Universitaet Muenchen (DE)) /COMPASS NA58 Collaboration COMPASS is a multi-purpose experiment operated at CERN for investigations of the strong interaction from low to medium energy scales. At low energies, photon-pion interactions provide input for understanding the effective dynamics of strongly bound states of quarks and gluons, most prominently the recent measurement of the polarisability of the charged pion. [...] COMPASS-PROC-2016-001.- Geneva : CERN, 2015 - 8. Fulltext: PDF;
2016-09-28
07:58
Extraction of the $\pi^+\pi^-$ Subsystem in Diffractively Produced $\pi^-\pi^+\pi^-$ at COMPASS / Krinner, Fabian (Munich, Tech. U.) /for the COMPASS collaboration The COMPASS experiment at CERN has collected a large data sample of 50 million diffractively produced $\pi^-\pi^+\pi^-$ events using a $190\,$GeV$/c$ negatively charged hadron beam. The partial-wave analysis (PWA) of these high-precision data reveals previously unseen details. [...] arXiv:1609.08514.- 2017 - 6 p. - Published in : JPS Conf.Proc. 13 (2017) 020028 Fulltext: PDF; External link: Preprint In : Meson-Nucleon Physics and the Structure of the Nucleon, Kyoto, Japan, 25 - 30 Jul 2016, pp.020028
2016-07-27
06:00
Tests of Chiral perturbation theory with COMPASS / Friedrich, Jan M (CERN) /COMPASS Collaboration The COMPASS experiment at CERN accesses pion-photon reactions via the Primakoff effect., where high-energetic pions react with the quasi-real photon field surrounding the target nuclei. When a single real photon is produced, pion Compton scattering is accessed and from the measured cross-section shape, the pion polarisability is determined. [...] 2014 - 4 p. - Published in : EPJ Web Conf. 73 (2014) 05011 Fulltext: PDF; In : 13th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon, Rome, Italy, 30 Sep - 4 Oct 2013, pp.05011
2016-06-08
06:45
New results from COMPASS / Kabuß, Eva-Maria (Mainz U.) /COMPASS Collaboration An overview on recent COMPASS results is given, including the extraction of the longitudinal spin structure functions interpreted with a NLO QCD fit, new results on the gluon polarisation and a measurement of pion and kaon multiplicities with a LO extraction of quark-to-hadron fragmentation functions SISSA, 2015 - 6 p. - Published in : PoS: EPS-HEP2015 (2015) , pp. 502 Fulltext: PDF; External link: Published version from PoS In : European Physical Society Conference on High Energy Physics 2015, Vienna, Austria, 22 - 29 Jul 2015, pp.502
2016-06-08
06:45
Generalized Parton Distributions program at COMPASS / Fuchey, Eric (Saclay) /COMPASS Collaboration SISSA, 2015 - Published in : PoS: QCDEV2015 (2015) , pp. 048 Fulltext: PDF; External link: Published version from PoS In : QCD Evolution Workshop, Newport News, VA, USA, 26-30 May 2015, pp.048
2016-06-08
06:45
Precision Hadron Spectroscopy at COMPASS - The Scalar Isoscalar Meson Spectrum - / Austregesilo, Alexander (Munich, Tech. U.) /COMPASS Collaboration SISSA, 2015 - Published in : PoS: Bormio2015 (2015) , pp. 022 Fulltext: PDF; External link: Published version from PoS In : 53rd International Winter Meeting on Nuclear Physics, Bormio, Italy, 26 - 30 Jan 2015, pp.022 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9268147349357605, "perplexity": 5637.190028169393}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187825464.60/warc/CC-MAIN-20171022203758-20171022223758-00108.warc.gz"} |
https://tex.stackexchange.com/questions/1483/whats-a-good-multiplatform-text-editor-system/1487 | # What's a good multiplatform text editor/system? [closed]
In the past, I've given up learning LaTeX because:
General
• Installing and using fonts is a pain.
• Simple things like custom page headers are insufferably hard to implement.
• Documentation for the above items is incomplete.
• LaTeX shows 10 errors for every 1 SLOC, so the code is impossible to debug.
• So many errors that I feel like my code will never compile.
• It's a pain having to scroll/find a previewed page every time I update it.
Cross-compatibility
• Code that compiles in LyX doesn't compile in TeXnicCenter/MiKTeX.
• Code that compiles in TeXnicCenter/MiKTeX doesn't compile in TeXShop/MacTeX.
• Code that compiles in TeXShop/MacTeX doesn't compile in LyX.
• Specifically, adding newlines breaks compilation.
Systems
• TeXShop/MacTeX requires 1GB of hard drive space.
• TeXShop has no Windows or Linux version.
• TeXShop has few graphical abilities. I would do better with vi or emacs.
• TeXnicCenter has no Linux or Mac OS X version.
• TeXnicCenter updates references such as table of contents and BibTeX every three compiles.
• TeXnicCenter compilation shortcut requires four button presses on a Mac laptop.
• LyX's WYSIWYG isn't really a WYSIWYG.
I was able to quickly learn Perl, Python, Ruby, newLISP, and Haskell because they don't have these problems. Instead, these languages offer:
• A single multiplatform, standard edition.
• Alternative editions for the minority of users who really need them.
• A small collection of binaries: perl, cpan; python, pythonw; ruby, irb, rdoc; newlisp; ghc, ghci, runghc, hugs, runhugs.
• All-in-one installers: ActiveState Perl, Python, RubyInstaller, newLISP, Haskell Platform.
• Small installation size (with the exception of GHC Haskell vs Hugs)
• Detailed tutorials with solutions for common errors.
In conclusion, I reserve judgment on TeX/LaTeX until the community not only produces a multiplatform system, but champions it in a highly visible way. LyX isn't even mentioned at Obtaining LaTeX.
• This is a rant why you do not want to use LaTeX, not a question. So, what exactly is your question? – Caramdir Aug 10 '10 at 15:21
• TeX Live requires 1GB of hard drive space. Light installs don't. – Charles Stewart Aug 10 '10 at 15:22
• TeX Live has no Mac OS X version. It installs just fine. – Charles Stewart Aug 10 '10 at 15:22
• TeXlive does not require 1 GB. The ‘full’ scheme does, not you can install light or medium schemes instead, and then use tlmgr to install any additional packages individually. – frabjous Aug 10 '10 at 15:32
• That TeX is turing complete is beside the point - it has a very different purpose. But please do post (maybe as a new question?) the issue you've had with code not compiling under MacTeX. Except for missing (or different versions of) packages, I've never had any issues compiling under different platforms. Likely that issue is fixable. (PS: Last I checked, MS Word does not run on Linux, so I'd hardly call it 'multiplatform'...) – Neil Olver Aug 10 '10 at 15:39
## 5 Answers
• TeXworks is a multi-platform editor and user friendly. It can use the same input encoding on Windows and on Linux and Mac OS X.
• Texmaker is multi-platform and a complex editor
• TeX Live is a multi-platform distribution. It worked fine for me on Linux and on Windows.
• LyX is cross-platform as well.
• TeXworks looks good. If it uses MiKTeX, MacTeX, etc. then I will still have cross-compilation errors. I've already discussed TeX Live and Lyx. – mcandre Aug 10 '10 at 15:09
• What do you mean by "cross-compilation". Since the target is always a .pdf or .ps file cross-compilation doesn't make sense (see en.wikipedia.org/wiki/Cross_compilation for a definition of the term) – Caramdir Aug 10 '10 at 15:24
• Caramdir, I of course mean compiling a PDF within a TeX system on Mac, Windows, and Linux. Yes, a PDF is a portable format. What's not portable is TeX code to generate the PDF. – mcandre Aug 10 '10 at 15:33
• In that case use a cross-platform distribution like TeX Live besides your cross-platform editor TeXworks. If you choose a platform specific editor it's not the fault of the editor. I don't think the editor has to refuse to work with os specific distris. – Stefan Kottwitz Aug 10 '10 at 15:34
• Thank you, Stefan. Note that TexMaker is dead, with no redirect to its successor, TexMakerX: texmakerx.sourceforge.net – mcandre Aug 10 '10 at 15:38
I am glad you are still willing to give TeX a shot! The learning curve can be steep, but hopefully this site can help. There are already answers for most of the points you raised:
Installing and using fonts is a pain.
This can be difficult- but package management tools like TeX Live's tlmgr amd MikTeX's mpm can take most of the pain away. The LaTeX Font Catalouge is a great place to see which fonts are available and how to use them.
TeX and LaTeX are moving towards tighter integration with system fonts through the efforts put into the XeTeX and LuaTeX engines. See the fontspec package for details on how to use those engines to access system fonts.
Simple things like custom page headers are insufferably hard to implement.
There are packages and class files that simplify this considerably. The fancyhdr package is a good choice and the memoir document class has comparable support baked-in.
Also see, How to set the font for a section for similar discussion concerning section and chapter headings.
LaTeX shows 10 errors for every 1 SLOC, so the code is impossible to debug.
Most of the output of TeX and LaTeX consists of notes about where the typesetting engine was forced to make sub-optimal decisions in order to produce a document that is better overall. All the noise about "badness" is related to this- badness is a metric that TeX tries to optimize to a minimum when typesetting. See Formatting the console output of Latex for information about how to reduce the verbosity of the log output.
It's a pain having to scroll/find a previewed page every time I update it.
A good editor should help with this.
Code that compiles in LyX doesn't compile in TeXnicCenter/MiKTeX.
This is most likely because LyX code is not LaTeX code- it won't compile outside of the LyX environment unless exported. This also means that LaTeX code won't compile in LyX unless imported or transcribed.
Code that compiles in TeXnicCenter/MiKTeX doesn't compile in TeXShop/MacTeX.
Probably due to missing packages- tlmgr and mpm should help with this. mpm is more helpful with on-the-fly installation of missing components.
TeXShop/MacTeX requires 1GB of hard drive space.
This is for the full everything-including-the-kitchen-sink install. You can select subsections when installing via the install-tl instructions are here. See also Why is the MacTeX distribution so large? Is there anything smaller for OS X?.
TeXnicCenter updates references such as table of contents and BibTeX every three compiles.
This is by design in LaTeX. To get a complete Bibliography with references you must run:
pdflatex document
bibtex document
pdflatex document
pdflatex document
This is because TeX writes out metadata about cross-references that gets used to enhance the output on subsequent runs:
1. On the first pdflatex run, information gets written concerning which citations are needed.
2. bibtex uses that information to pull the required citations from a database.
3. pdflatex then uses the bibtex output to produce a bibliography.
4. With a bibliography present, pdflatex can finally insert citations in the text.
See Tools for automating document compilation for ways to make this less of a chore.
LyX's WYSIWYG isn't really a WYSIWYG.
It is not supposed to be.
TeX-based systems do have a pile of quirks and "WTF moments" but compared to systems like MS Word you usually only have to jump these hurdles once. If I want to reuse a nicely formatted header/footer that I had in a document- I only have to open the source to find the exact steps that were executed to create them. And if there were "WTF issues" or "magic", I usually have a good comment explaining why part of the process looks like voodoo. Comparatively, I still waste a lot of time in MS Word with similar tasks because there is no good way to record in black and white the exact sequences of menu selections and clicks that led to a given output.
TeX requires a larger up-front investment of time to get comfortable with, but pays large dividends and your investment in learning the system will not be suddenly and drastically depreciated as was the case with the complete overhaul that occurred in MS Office 2007.
• Nice detailed answer that isn't snarky like some of the rest. Thank-you for striving for quality. – Yossi Farjoun Aug 10 '10 at 16:40
• Nice answer. You might add a notice about synctex, which is sipported out of the box by various editors, among them TexWorks and TexMaker. – matth Nov 11 '11 at 9:20
In my opinion, TexWorks + TeXLive is the user-friendliest cross-platform solution to TeX/LaTeX editing and previewing. I think LyX's attempt at WYSIWYG creates more confusion than it solves.
Incidentally, there is a Mac OSX version of TeX Live, and is called MacTeX. It comes with a bunch of extra features, but at its core it is the TeX Live distribution repackaged for easier installation and use on Mac OSX.
• Plus plain old Texlive works just fine on Mac OSX. I'm not interested in Mactex's extra features, I want my setup on Linux and Mac OSX to be the same. – Charles Stewart Aug 10 '10 at 15:32
• I use MacTeX but only for the slightly nicer installer (respecting the Mac file locations), but I miss out all of the 'extras', which like Charles I don't want/need. – Joseph Wright Aug 10 '10 at 16:39
• @Joseph: If you use Texlive on both Linux and Mac OS, then "respecting the Mac file locations" may be something of a mixed blessing. – Charles Stewart Aug 11 '10 at 8:24
Vim, Emacs, Texworks, Texmaker, Kile and LyX are all cross-platform (though setting up Kile is tricky on some).
Unicode is the future. Save your files with Unicode encoding and refuse to use text editors that can't or don't. That should eliminate half your problems.
Incompatibilities between different versions of TeX systems do happen, but I think they tend to be temporary, and when identified, fixed ASAP. That's been my experience anyway. Just be sure to keep your system up to date.
FWIW, I’ve personally not have problems compiling source with DOS newlines using TeXlive on linux.
There's no doubt that the Tex family of software is disordered, tricky, and hard to master. If mastering Tex is the key, and that means mastering it in the same way as you want to master Haskell, then something minimalist will suffice: program in Plain Tex on Xetex. Then work through the following detailed tutorial:
• Knuth, 1984, The TeXbook
which has lots of exercises, and is supported by an excellent reference work, TeX by Topic.
This is not the easiest way to use the Tex system for document processing, but it seems to address your learnability complaints. I believe that Texlive offers the multiplatform standard you are looking for, but it is not the easiest install, and, as I noted elsewhere, there are sometimes compatibility issues from one year to the next.
As for size, well, Word for Mac 2004 plus VBA scripting is over 300 Mb, and has a much smaller font collection than Texlive's full install.
• As for ease if install: TeX Live for Windows comes (afaik) with a gui, has MacTeX for OS X and on Linux one usually installs everything through the Linux distribution's package manager anyway. – Caramdir Aug 10 '10 at 15:51 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.870100736618042, "perplexity": 4454.05212154771}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107885059.50/warc/CC-MAIN-20201024223210-20201025013210-00530.warc.gz"} |
https://socratic.org/questions/58019ff17c01493a8404549a | Algebra
Topics
# Question #4549a
Oct 15, 2016
$x = 2$
#### Explanation:
${9}^{x} - 9 = 8 \left({3}^{x}\right)$
$\implies {\left({3}^{x}\right)}^{2} - 8 \left({3}^{x}\right) - 9 = 0$
Let $u = {3}^{x}$
${u}^{2} - 8 u - 9 = 0$
$\implies \left(u - 9\right) \left(u + 1\right) = 0$
$\implies u - 9 = 0 \mathmr{and} u + 1 = 0$
$\implies u = 9 \mathmr{and} u = - 1$
$\implies {3}^{x} = 9 \mathmr{and} {3}^{x} = - 1$
As ${3}^{x} \in \left(0 , \infty\right)$ for $x \in \mathbb{R}$, we can dismiss the second possibility
$\implies {3}^{x} = 9$
$\implies {3}^{x} = {3}^{2}$
$\therefore x = 2$
##### Impact of this question
161 views around the world | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 14, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7877166867256165, "perplexity": 15642.290015712173}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-39/segments/1568514575674.3/warc/CC-MAIN-20190922201055-20190922223055-00550.warc.gz"} |
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I don''t really know whether this qualifies as a "for beginners" question, but I''m so clueless on it it may as well be. Anyway: I''m working on a map editor, and trying to include a fill tool. The function I use is as follows.
void Fill(int atx, int aty, int filltile, int clickedtile) { if (map[atx][aty][0] != clickedtile){return;} else{ map[atx][aty][0] = filltile; for (int x = atx-1; x < atx+2; x++) for (int y = aty-1; y < aty+2; y++) if (map[x][y][0] == clickedtile) if (x != atx || y != aty) Fill(x,y,filltile,clickedtile); } }
It is meant to fill in any tile until it reaches something that is different. That is to say, if you click on tile 4, it fills unless it hits a tile that is not tile 4. clickedtile is the number of the tile clicked on, and fill tile is the tile you''re filling the area with. atx and aty are just the location. This code works fine on smaller regions, but how can I stop it from crashing in larger regions? -Arek the Absolute
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for (int x = atx-1; x < atx+2; x++)
for (int y = aty-1; y < aty+2; y++)
How does it know that aty+2 exists (going outside the bounds of the array)? I''m not understanding where you''re getting -1 and +2 from...
"I''ve learned something today: It doesn''t matter if you''re white, or if you''re black...the only color that REALLY matters is green"
-Peter Griffin
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THANKS!!! =D
I can''t believe I missed that. Here''s the corrected code, and it WORKS!
void Fill(int atx, int aty, int filltile, int clickedtile){ if (map[atx][aty] != clickedtile){return;} else if ((atx < 0) || (aty < 0) || (atx > tile_width) || (aty > tile_height)){return;} else{ map[atx][aty] = filltile; for (int x = atx-1; x < atx+2; x++) for (int y = aty-1; y < aty+2; y++) if (map[x][y] == clickedtile) if (x != atx || y != aty) Fill(x,y,filltile,clickedtile); }}
Anyway, I''ll explain how it works, as you said you didn''t understand where atx-1 and +2 came from. Thanks to EvilCrap BTW, as this is just a corrected version of his idea.
You send it the location, and it exits if it is not the same tile type you clicked on. Then it checks to see if its within the bounds of the map, and exits if not. If it''s still going, it fills the tile, and then does the two for loops. This checks all the surrounding tiles, thereby spreading out the region of the fill. aty-1 means the tile immediately above the current one, and it continues while it''s less than aty+2, which is to say it checks aty-1, aty, and aty+1. This causes the region of effect to spread out, and "fill" everything necessary. Hope that''s clear enough, but I''m saving the tutorial speech for when I''m done with the whole map editor.
-Arek the Absolute
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Well.. It mostly works. It does still bug out if the maps are large, and you try to fill the whole thing. If anyone still has suggestions, they''re more then welcome...
-Arek the Absolute
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your problem is that you are usiong a recursive function (it calls itself, and that time it calls itself, et cetera)... so each time those four parameters are put on the stack, and you are running out of stack space (on larger maps). this is the problem with recursive functions
luckily, most recursive algorithms can be re-coded to not be recursive, and thus avoid the stack overflow problem. i had a problem very similar to yours a while back (i was trying to flood-fill a tile map recursively), but unfortunately i no longer have that code. i think i had the function make a boolean array of which squares were already checked, or something along those lines... sorry if this doesn''t help.
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https://socratic.org/questions/how-do-you-solve-1-7-16-s-9-8 | Algebra
Topics
# How do you solve 1 7/16 + s = 9/8?
Jul 16, 2015
$\textcolor{red}{s = - \frac{5}{16}}$
#### Explanation:
$1 \frac{7}{16} + s = \frac{9}{8}$
I would multiply both sides of the equation by the lowest common multiple of the denominators.
The lowest common multiple of 16 and 8 is 16.
16(1 7/16 + s) = 16 × 9/8
16×23/16 + 16s = 18
$23 + 16 s = 18$
Subtract 23 from each side,
$23 + 16 s - 23 = 18 - 23$
$16 s = - 5$
Divide both sides by 16.
$\frac{16 s}{16} = - \frac{5}{16}$
$s = - \frac{5}{16}$
Check:
$1 \frac{7}{16} + s = 1 \frac{7}{16} + \left(- \frac{5}{16}\right) = \frac{23}{16} - \frac{5}{16} = \frac{18}{16} = \frac{9}{8}$
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https://en.wikipedia.org/wiki/Alcor%E2%80%93Mizar | # Mizar and Alcor
(Redirected from Alcor–Mizar)
Observation data Constellation Epoch J2000 Equinox J2000 Mizar and Alcor in constellation Ursa Major Ursa Major 13h 23m 55.5s[1] +54° 55′ 31″[1] 2.27[1] A2Vp/A2Vp/A1m/A5V[2] 0.02[1] Radial velocity (Rv) −6.31[1] km/s Proper motion (μ) RA: 119.01[1] mas/yr Dec.: −25.97[1] mas/yr Parallax (π) 38.01 ± 1.71[1] mas Distance 86 ± 4 ly (26 ± 1 pc) Absolute bolometric magnitude (Mbol) 0.91 ± 0.07 / 0.91 ± 0.07[3] Primary Mizar Aa Companion Mizar Ab Period (P) 20.53835 ± 0.00005 d Semi-major axis (a) 9.83 ± 0.03 mas Eccentricity (e) 0.5354 ± 0.0025 Inclination (i) 60.5 ± 0.3° Longitude of the node (Ω) 106.0 ± 0.4° Periastron epoch (T) JD 2447636.07 ± 0.02 Argument of periastron (ω) (secondary) 104.3 ± 0.3° Semi-amplitude (K1) (primary) 69.1 km/s Semi-amplitude (K2) (secondary) 67.2 km/s Mass 2.43 ± 0.07 M☉ Radius 2.4 ± 0.1 R☉ Luminosity 33.3 ± 2.1 L☉ Temperature 9000 ± 200 K Mass 2.50 ± 0.07 M☉ Radius 2.4 ± 0.1 R☉ Luminosity 33.3 ± 2.1 L☉ Temperature 9000 ± 200 K Mizat, Mirza, Mitsar, Vasistha, ζ Ursae Majoris, ζ UMa, Zeta UMa, 79 Ursae Majoris, BD+55 1598A, CCDM J13240+5456AB, FK5 497, GC 18133, HD 116656, HIP 65378, HR 5054, PPM 34007, SAO 28737, WDS J13239+5456Aa,Ab. SIMBAD data
Alcor
Observation data
Epoch J2000.0 Equinox J2000.0
Constellation Ursa Major
Right ascension 13h 25m 13.5s[1]
Declination +54° 59′ 17″[1]
+3.99[4]
Absolute magnitude (V) +2.00[4]
Distance 81.7 ± 0.2[citation needed] ly
(25.1 ± 0.08[citation needed] pc)
Spectral type A5Vn / M[4]
Other designations
Saidak, Suha, Arundhati, g Ursae Majoris, 80 Ursae Majoris, BD+55 1603, CCDM J13240+5456D, GC 18155, HD 116842, HIP 65477, HR 5062, PPM 34021, SAO 28751, WDS J13239+5456Ca,Cb.
Database references
Mizar and Alcor are two stars forming a naked eye double star in the handle of the Big Dipper (or Plough) asterism in the constellation of Ursa Major. Mizar is the second star from the end of the Big Dipper's handle, and Alcor its faint companion.
Mizar, also designated Zeta Ursae Majoris (ζ Ursae Majoris, abbreviated Zeta UMa, ζ UMa), is itself a quadruple system and Alcor, also designated 80 Ursae Majoris (80 UMa), is a binary, the pair together forming a sextuple system. The whole system lies about 83 light-years away from the Sun, as measured by the Hipparcos astrometry satellite.[1][5][6]
## Nomenclature
ζ Ursae Majoris (Latinised to Zeta Ursae Majoris) is Mizar's Bayer designation. 80 Ursae Majoris is Alcor's Flamsteed designation.
The traditional name Mizar derives from the Arabic المئزر miʼzar meaning 'apron; wrapper, covering, cover'.[7] Alcor was also originally Arabic سها suhā, meaning either the ‘forgotten’ or ‘neglected’ one.;[8] notable as a faintly perceptible companion of Mizar.
In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[9] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[10] included a table of the first two batches of names approved by the WGSN; which included Mizar for Zeta UMa and Alcor for 80 UMa. They are now so entered in the IAU Catalog of Star Names.[11]
## Stellar system
Mizar is a visual double with a separation of 14.4 arcseconds, each of which is a spectroscopic binary. Its apparent magnitude is 2.23 and its spectral class is A2V.
With normal eyesight Alcor appears at about 12 minutes of arc from Mizar. Alcor is of magnitude 3.99 and spectral class A5V. It has a faint red dwarf companion separated by 1 second of arc.[12]
Mizar and Alcor's proper motions show they move together (along with the other stars of the Big Dipper—except Alpha Ursae Majoris (Dubhe) and Eta Ursae Majoris (Alkaid)—they are members of the Ursa Major Moving Group, a mostly dispersed group of stars sharing a common birth), but it has yet to be demonstrated conclusively that they are gravitationally bound. Recent studies indicate that the Alcor binary and Mizar quadruple are somewhat closer together than previously thought: approximately 74,000 ± 39,000 AU or 0.5–1.5 light years.[13]
More components of the Mizar system were discovered with the advent of the telescope and spectroscopy; an easily split visual target, Mizar was the first telescopic binary discovered, most probably by Benedetto Castelli who in 1617 asked Galileo Galilei to observe it. Galileo then produced a detailed record of the double star. Later, around 1650, Riccioli wrote of Mizar appearing as a double. The secondary star (designated Mizar B) has magnitude 4.0 and spectral class A7, and comes within 380 AU of the primary (Mizar A); the two take thousands of years to revolve around each other.
Mizar A was the first spectroscopic binary to be discovered, by Pickering in 1889. Some spectroscopic binaries cannot be visually resolved and are discovered by studying the spectral lines of the suspect system over a long period of time. The two components of Mizar A are both about 35 times as bright as the Sun, and revolve around each other in about 20 days 12 hours and 55 minutes. Mizar B was later found to be a spectroscopic binary as well, its components completing an orbital period every six months. In 1996, 107 years after their discovery, the components of the Mizar A binary system were imaged in extremely high resolution using the Navy Prototype Optical Interferometer.
## Other names
Mizar is known as Vashistha and Alcor as Arundhati, two of the Saptarishi, in traditional Indian astronomy.[14] As a married couple, they are considered to symbolize marriage and in some Hindu communities to this day priests conducting a wedding ceremony allude to or point out the constellation as a symbol of the closeness marriage brings to a couple.[15]
Al-Sahja was the rhythmical form of the usual Suha. It appears as الخوّار al-Khawwar, 'the Faint One', in an interesting list of Arabic star names, published in Popular Astronomy, January 1895, by Professor Robert H. West, of the Syrian Protestant College at Beirut.
Although the statement has been made that Alcor was not known to the ancient Greeks, there is an old story that it was the Lost Pleiad Electra, which had wandered here from her companions and became Alopex, the Fox. A Latin title was Eques Stellula, the Little Starry Horseman; Eques, the Cavalier, is from the 17th-century German astronomer Bayer. Mizar and Alcor together are sometimes called the "Horse and Rider" (and popularly, in England, Jack on the Middle Horse), with Mizar being the horse. The Persian astronomer Al Biruni (973–1048 A.D.) mentioned its importance in the family life of the Arabs on the 18th day of the Syrian month Adar, the March equinox; and a modern story of that same people makes it the infant of the walidan (mother?) among the three Banat (the Mourners: Alioth, Mizar, and Alkaid).
Chinese Taoism personifies Ursa Majoris as the Lu star.
Mizar is Chickadee and Alcor is his cooking pot in the Mi'kmaq myth of the great bear and the seven hunters.[16]
## Test of eyesight
The ability to resolve Mizar and Alcor with the naked eye is often quoted as a test of eyesight, although even people with quite poor eyesight can see the two stars.[8] Arabic literature says that only those with the sharpest eyesight can see the companion of Mizar. The 14th century Arabian lexicographer Firuzabadi called it "Our Riddle", while the 13th century Persian astronomical writer Zakariya al-Qazwini said that "people tested their eyesight by this star." Humboldt wrote of it as being seen with difficulty, and Arago similarly alluded to it. Astronomer Sir Patrick Moore suggested that this in fact refers to another star that lies visually between Mizar and Alcor.[17] This star is occasionally known as "Ludwig's Star", it was observed on 2 December 1722 by the German astronomer Johann Georg Liebknecht (23 April 1679 – 17 September 1749) and named in honour of his patron the Landgrave Ludwig of Hessen-Darmstadt.[18] Liebknecht thought it was a planet, but it had already been observed in exactly the same position by Benedetto Castelli (1577–1643) approximately a century earlier in 1616, which indicated it was a background star.
The Arabs in the desert regarded it as a test of penetrating vision; and they were accustomed to oppose "Suhel" to "Suha" (Canopus to Alcor) as occupying respectively the highest and lowest posts in the celestial hierarchy. So that Vidit Alcor, at non lunam plenam (Latin for "he saw Alcor, but not the full moon"), came to be a proverbial description of one keenly alive to trifles, but dull of apprehension for broad facts.
— Agnes M, Clerke, The Herschels and Modern Astronomy (1901)[19]
In Japanese mythology, Alcor is known as the lifespan star or "jumyōboshi" (寿命星) as it was believed that one who could not see this star would pass away by year's end. The Japanese manga Fist of the North Star uses this legend as a model for its death-omen star (死兆星), in which it was said that people who saw the star would die later in the year.
## References
1. van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. Bibcode:2007A&A...474..653V. arXiv:. doi:10.1051/0004-6361:20078357.
2. ^ Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. Bibcode:2008MNRAS.389..869E. arXiv:. doi:10.1111/j.1365-2966.2008.13596.x.
3. ^ a b c Hummel, C. A.; Mozurkewich, D.; Armstrong, J. T.; Hajian, Arsen R.; Elias Ii, N. M.; Hutter, D. J. (1998). "Navy Prototype Optical Interferometer Observations of the Double Stars Mizar a and Matar". The Astronomical Journal. 116 (5): 2536. Bibcode:1998AJ....116.2536H. doi:10.1086/300602.
4. ^ a b c Mamajek, Eric E.; Kenworthy, Matthew A.; Hinz, Philip M.; Meyer, Michael R. (2010). "Discovery of a Faint Companion to Alcor Using MMT/AO 5 μm Imaging". The Astronomical Journal. 139 (3): 919–925. Bibcode:2010AJ....139..919M. arXiv:. doi:10.1088/0004-6256/139/3/919.
5. ^ Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; Hoeg, E.; Bastian, U.; Bernacca, P. L.; Crézé, M.; Donati, F.; Grenon, M.; Grewing, M.; Van Leeuwen, F.; Van Der Marel, H.; Mignard, F.; Murray, C. A.; Le Poole, R. S.; Schrijver, H.; Turon, C.; Arenou, F.; Froeschlé, M.; Petersen, C. S. (1997). "The HIPPARCOS Catalogue". Astronomy and Astrophysics. 323: L49. Bibcode:1997A&A...323L..49P.
6. ^ Perryman, Michael (2010). "The Making of History's Greatest Star Map". The Making of History's Greatest Star Map:. Astronomers’ Universe. Heidelberg: Springer-Verlag. Bibcode:2010mhgs.book.....P. ISBN 978-3-642-11601-8. doi:10.1007/978-3-642-11602-5.
7. ^ Wehr, Hans (1994). A Dictionary of Modern Written Arabic (Arabic-English) (4 ed.). Urbana, Illinois: Spoken Language Services. p. 17. ISBN 0879500034.
8. ^ a b Bohigian, George M. (2008). "An Ancient Eye Test—Using the Stars". Survey of Ophthalmology. 53 (5): 536–9. PMID 18929764. doi:10.1016/j.survophthal.2008.06.009.
9. ^ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
10. ^ "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Retrieved 28 July 2016.
11. ^ "IAU Catalog of Star Names". Retrieved 28 July 2016.
12. ^ Zimmerman, Neil; Oppenheimer, Ben R.; Hinkley, Sasha; Brenner, Douglas; Parry, Ian R.; Sivaramakrishnan, Anand; Hillenbrand, Lynne; Beichman, Charles; Crepp, Justin R.; Vasisht, Gautam; Roberts, Lewis C.; Burruss, Rick; King, David L.; Soummer, Rémi; Dekany, Richard; Shao, Michael; Bouchez, Antonin; Roberts, Jennifer E.; Hunt, Stephanie (2010). "Parallactic Motion for Companion Discovery: An M-Dwarf Orbiting Alcor". The Astrophysical Journal. 709 (2): 733–740. Bibcode:2010ApJ...709..733Z. arXiv:. doi:10.1088/0004-637X/709/2/733.
13. ^ Mamajek, Eric E.; Kenworthy, Matthew A.; Hinz, Philip M.; Meyer, Michael R. (2009). "Discovery of a Faint Companion to Alcor Using MMT/AO 5 $\mu$m Imaging". The Astronomical Journal. 0911 (3): 919–925. Bibcode:2010AJ....139..919M. arXiv: [astro-ph.SR]. doi:10.1088/0004-6256/139/3/919.
14. ^ V.Chandran (1993-01-01). Astronomy Quiz Book. Pustak Mahal, 1993. ISBN 978-81-223-0366-7. ... the seven rishis in the constellation Saptarishi (Ursa Major) ... In Vasishta (Zeta), its tiny companion star is named after Arundhati, the wife of Vasishta ... today known by their Arabic names Dubhe (Kratu), Merak (Pulaha), Phekda (Pulastya), Megrez (Atri), Benetnash (Marichi) and Mizar (Vasishta) ...
15. ^ M.K.V. Narayan (2007-04-01). Flipside of Hindu Symbolism: Sociological and Scientific Linkages in Hinduism. Fultus Corporation, 2007. ISBN 978-1-59682-117-0. ... At this time, the pundit shows the couple the Arundhati star in the sky to suggest closeness of the married couple. ... the star Vasishta of the Big Dipper constellation (Saptarishi Mandalam) and it is the star system called Mizar ...
16. ^ The Celestial Bear, A Micmac Legend
17. ^ Moore, Patrick; Watson, John (2012). "Observing the Stars and Galaxies". Astronomy with a Budget Telescope. Patrick Moore's Practical Astronomy Series. p. 65. ISBN 978-1-4614-2160-3. doi:10.1007/978-1-4614-2161-0_5.
18. ^ "Big Dipper Stars in Summer Sky". Space.com. Retrieved 2017-03-03.
19. ^ Clerke, Agnes Mary (1901). The Herschels and Modern Astronomy. The Century Science Series. London: Cassell and Company. p. 82. OCLC 4530404. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7099314332008362, "perplexity": 16978.311554331245}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-39/segments/1505818687281.63/warc/CC-MAIN-20170920123428-20170920143428-00318.warc.gz"} |
https://plato.sydney.edu.au/entries/decision-theory/ | # Decision Theory
First published Wed Dec 16, 2015; substantive revision Fri Oct 9, 2020
Decision theory is concerned with the reasoning underlying an agent’s choices, whether this is a mundane choice between taking the bus or getting a taxi, or a more far-reaching choice about whether to pursue a demanding political career. (Note that “agent” here stands for an entity, usually an individual person, that is capable of deliberation and action.) Standard thinking is that what an agent chooses to do on any given occasion is completely determined by her beliefs and desires or values, but this is not uncontroversial, as will be noted below. In any case, decision theory is as much a theory of beliefs, desires and other relevant attitudes as it is a theory of choice; what matters is how these various attitudes (call them “preference attitudes”) cohere together.
The focus of this entry is normative decision theory. That is, the main question of interest is what criteria an agent’s preference attitudes should satisfy in any generic circumstances. This amounts to a minimal account of rationality, one that sets aside more substantial questions about appropriate desires and reasonable beliefs, given the situation at hand. The key issue for a minimal account is the treatment of uncertainty. The orthodox normative decision theory, expected utility (EU) theory, essentially says that, in situations of uncertainty, one should prefer the option with greatest expected desirability or value. (Note that in this context, “desirability” and “value” should be understood as desirability/value according to the agent in question.) This simple maxim will be the focus of much of our discussion.
The structure of this entry is as follows: Section 1 discusses the basic notion of “preferences over prospects”, which lies at the heart of decision theory. Section 2 describes the development of normative decision theory in terms of ever more powerful and flexible measures of preferences. Section 3 discusses the two best-known versions of EU theory. Section 4 considers the broader significance of EU theory for practical action, inference, and valuing. Section 5 turns to prominent challenges to EU theory, while Section 6 addresses sequential decisions, and how this richer setting bears on debates about rational preferences.
## 1. What are preferences over prospects?
The two central concepts in decision theory are preferences and prospects (or equivalently, options). Roughly speaking, when we (in this entry) say that an agent “prefers” the “option” $$A$$ over $$B$$ we mean that the agent takes $$A$$ to be more desirable or choice-worthy than $$B$$. This rough definition makes clear that preference is a comparative attitude. Beyond this, there is room for argument about what preferences over options actually amount to, or in other words, what it is about an agent (perhaps oneself) that concerns us when we talk about his/her preferences over options. This section considers some elementary issues of interpretation that set the stage for introducing (in the next section) the decision tables and expected utility rule that for many is the familiar subject matter of decision theory. Further interpretive questions regarding preferences and prospects will be addressed later, as they arise.
Let us nonetheless proceed by first introducing basic candidate properties of (rational) preference over options and only afterwards turning to questions of interpretation. As noted above, preference concerns the comparison of options; it is a relation between options. For a domain of options we speak of an agent’s preference ordering, this being the ordering of options that is generated by the agent’s preference between any two options in that domain.
In what follows, $$\preceq$$ represents a weak preference relation. So $$A\preceq B$$ means that the agent we are interested in considers option $$B$$ to be at least as preferable as option $$A$$. From the weak preference relation we can define the strict preference relation, $$\prec$$, as follows: $$A\prec B\Leftrightarrow A\preceq B \ \& \ \neg (B\preceq A)$$, where $$\neg X$$ means “it is not the case that $$X$$”. The indifference relation, $$\sim$$, is defined as: $$A\sim B \Leftrightarrow A\preceq B \ \& \ B\preceq A$$. This represents that the agent we are interested in considers $$A$$ and $$B$$ to be equally preferable.
We say that $$\preceq$$ weakly orders a set $$S$$ of options whenever it satisfies the following two conditions:
Axiom 1 (Completeness)
For any $$A, B\in S$$: either $$A\preceq B$$ or $$B\preceq A$$.
Axiom 2 (Transitivity)
For any $$A, B, C\in S$$: if $$A\preceq B$$ and $$B\preceq C$$ then $$A\preceq C$$.
The above can be taken as a preliminary characterisation of rational preference over options. Even this limited characterisation is contentious, however, and points to divergent interpretations of “preferences over prospects/options”.
Start with the Completeness axiom, which says that an agent can compare, in terms of the weak preference relation, all pairs of options in $$S$$. Whether or not Completeness is a plausible rationality constraint depends both on what sort of options are under consideration, and how we interpret preferences over these options. If the option set includes all kinds of states of affairs, then Completeness is not immediately compelling. For instance, it is questionable whether an agent should be able to compare the option whereby two additional people in the world are made literate with the option whereby two additional people reach the age of sixty. If, on the other hand, all options in the set are quite similar to each other, say, all options are investment portfolios, then Completeness is more compelling. But even if we do not restrict the kinds of options under consideration, the question of whether or not Completeness should be satisfied turns on the meaning of preference. For instance, if preferences merely represent choice behaviour or choice dispositions, as they do according to the “revealed preference theory” popular amongst economists (see Sen 1973), then Completeness is automatically satisfied, on the assumption that a choice must inevitably be made. By contrast, if preferences are understood rather as mental attitudes, typically considered judgments about whether an option is better or more desirable than another, then the doubts about Completeness alluded to above are pertinent (for further discussion, see Mandler 2001).
Most philosophers and decision theorists subscribe to the latter interpretation of preference as a kind of judgment that explains, as opposed to being identical with, choice dispositions and resultant choice behaviour (see, e.g., Hausman 2011a, 2011b; Dietrich and List, 2016a & 2016b; Bradley 2017; although see also Thoma 2020b and Vredenburgh 2020 for recent defences of “revealed preference theory”, at least in the context of empirical economics). Moreover, many hold that Completeness is not rationally required, since they think that rationality makes demands only on the judgments an agent actually holds, but says nothing of whether a judgement must be held in the first place. Nevertheless, following Richard Jeffrey (1983), most decision theorists suggest that rationality requires that preferences be coherently extendible. This means that even if your preferences are not complete, it should be possible to complete them without violating any of the conditions that are rationally required, in particular Transitivity.
This brings us to the Transitivity axiom, which says that if an option $$B$$ is weakly preferred to $$A$$, and $$C$$ weakly preferred to $$B$$, then $$C$$ is weakly preferred to $$A$$. A recent challenge to Transitivity turns on heterogeneous sets of options, as per the discussion of Completeness above. But here a different interpretation of preference is brought to bear on the comparison of options. The idea is that preferences, or judgments of desirability, may be responsive to a salience condition. For example, suppose that the most salient feature when comparing cars $$A$$ and $$B$$ is how fast they can be driven, and $$B$$ is no worse than $$A$$ in this regard, yet the most salient feature when comparing cars $$B$$ and $$C$$ is how safe they are, and that $$C$$ is no worse than $$B$$ in this regard. Furthermore, when comparing $$A$$ and $$C$$, the most salient feature is their beauty. In such a case, some argue (e.g., Temkin 2012) that there is no reason why Transitivity should be satisfied with respect to the preferences concerning $$A$$, $$B$$ and $$C$$. Others (e.g., Broome 1991a) argue that Transitivity is part of the very meaning of the betterness relation (or objective comparative desirability); if rational preference is a judgment of betterness or desirability, then Transitivity is non-negotiable. With respect to the car example, Broome would argue that the desirability of a fully specified option should not vary, simply in virtue of what other options it is compared with. Either the choice context affects how the agent perceives the option at hand, in which case the description of the option should reflect this, or else the choice context does not affect the option. Either way, Transitivity should be satisfied.
There is a more straightforward defence of Transitivity in preference; a defence that hinges on the sure losses that may befall anyone who violates the axiom. This is the so-called money pump argument (see Davidson et. al. 1955 for an early argument of this sort, but for recent discussion and revision of this argument, see Gustafsson 2010 & 2013). It is based on the assumption that if you find $$X$$ at least as desirable as $$Y$$, then you should be happy to trade the latter for the former. Suppose you violate Transitivity; for you: $$A\preceq B$$, $$B\preceq C$$ but $$C\prec A$$. Moreover, suppose you presently have $$A$$. Then you should be willing to trade $$A$$ for $$B$$. The same goes for $$B$$ and $$C$$: you should be willing to trade $$B$$ for $$C$$. You strictly prefer $$A$$ to $$C$$, so you should be willing to trade in $$C$$ plus some sum $$\x$$ for $$A$$. But now you are in the same situation as you started, having $$A$$ and neither $$B$$ nor $$C$$, except that you have lost $$\x$$! So in a few steps, each of which was consistent with your preferences, you find yourself in a situation that is clearly worse, by your own lights, than your original situation. The picture is made more dramatic if we imagine that the process could be repeated, turning you into a “money pump”. Hence, the argument goes, there is something (instrumentally) irrational about your intransitive preferences. If your preferences were transitive, then you would not be vulnerable to choosing a dominated option and serving as a money pump. Therefore, your preferences should be transitive.
While the aforementioned controversies have not been settled, the following assumptions will be made in the remainder of this entry: i) the objects of preference may be heterogeneous prospects, incorporating a rich and varied domain of properties, ii) preference between options is a judgment of comparative desirability or choice-worthiness, and iii) preferences satisfy both Completeness and Transitivity (although the former condition will be revisited in Section 5). The question that now arises is whether there are further general constraints on rational preference over options.
## 2. Utility measures of preference
In our continuing investigation of rational preferences over prospects, the numerical representation (or measurement) of preference orderings will become important. The numerical measures in question are known as utility functions. The two main types of utility function that will play a role are the ordinal utility function and the more information-rich interval-valued (or cardinal) utility function.
### 2.1 Ordinal utilities
It turns out that as long as the set of prospects/options, $$S$$, is finite, any weak order of the options in $$S$$ can be represented by an ordinal utility function. To be precise, let us say that $$u$$ is a utility function with domain $$S$$. We say that the function $$u$$ represents the preference $$\preceq$$ between the options in $$S$$ just in case:
$\tag{1}\text{For any}\ A, B \in S: u(A)\leq u(B) \Leftrightarrow A\preceq B$
Another way to put this is that, when the above holds, the preference relation can be represented as maximising utility, since it always favours option with higher utility.
The only information contained in an ordinal utility representation is how the agent whose preferences are being represented orders options, from least to most preferable. This means that if $$u$$ is an ordinal utility function that represents the ordering $$\preceq$$, then any utility function $$u'$$ that is an ordinal transformation of $$u$$—that is, any transformation of $$u$$ that also satisfies the biconditional in (1)—represents $$\preceq$$ just as well as $$u$$ does. Hence, we say that an ordinal utility function is unique only up to ordinal transformations.
The result referred to above can be summarised as follows:
Theorem 1 (Ordinal representation). Let $$S$$ be a finite set, and $$\preceq$$ a weak preference relation on $$S$$. Then there is an ordinal utility function that represents $$\preceq$$ just in case $$\preceq$$ is complete and transitive.
This theorem should not be too surprising. If $$\preceq$$ is complete and transitive over $$S$$, then the options in $$S$$ can be put in an order, from the most to the least preferred, where some options may fall in the same position (if they are deemed equally desirable) but where there are no cycles, loops, or gaps. Theorem 1 just says that we can assign numbers to the options in $$S$$ in a way that represents this order. (For a simple proof of Theorem 1, except for a strict rather than a weak preference relation, consult Peterson 2009: 95.)
Note that ordinal utilities are not very mathematically “powerful”, so to speak. It does not make sense, for instance, to compare the probabilistic expectations of different sets of ordinal utilities. For example, consider the following two pairs of prospects: the elements of the first pair are assigned ordinal utilities of 2 and 4, while those in the second pair are assigned ordinal utilities of 0 and 5. Let us specify a “flat” probability distribution in each case, such that each element in the two pairs corresponds to a probability of 0.5. Relative to this probability assignment, the expectation of the first pair of ordinal utilities is 3, which is larger than 2.5, the expectation of the second pair. Yet when we transform the ordinal utilities in a permissible way—for instance by increasing the highest utility in the second pair from 5 to 10—the ordering of expectations reverses; now the comparison is between 3 and 5. The significance of this point will become clearer in what follows, when we turn to the comparative evaluation of lotteries and risky choices. An interval-valued or cardinal utility function is necessary for evaluating lotteries/risky prospects in a consistent way. By the same token, in order to construct or conceptualise a cardinal utility function, one typically appeals to preferences over lotteries. (Although see Alt 1936 for a “risk-free” construction of cardinal utility, that is, one that does not appeal to lotteries.)
### 2.2 Cardinalizing utility
In order to get a cardinal (interval-valued) utility representation of a preference ordering—i.e., a measure that represents not only how an agent orders the options but also says something about the desirabilistic “distance” between options—we need a richer setting; the option set and the corresponding preference ordering will need to have more structure than for an ordinal utility measure. One such account, owing to John von Neumann and Oskar Morgenstern (1944), will be cashed out in detail below. For now, it is useful to focus on the kind of option that is key to understanding and constructing a cardinal utility function: lotteries.[1]
Consider first an ordering over three regular options, e.g., the three holiday destinations Amsterdam, Bangkok and Cardiff, denoted $$A$$, $$B$$ and $$C$$ respectively. Suppose your preference ordering is $$A\prec B \prec C$$. This information suffices to ordinally represent your judgement; recall that any assignment of utilities is then acceptable as long as $$C$$ gets a higher value than $$B$$ which gets a higher value than $$A$$. But perhaps we want to know more than can be inferred from such a utility function—we want to know how much $$C$$ is preferred over $$B$$, compared to how much $$B$$ is preferred over $$A$$. For instance, it may be that Bangkok is considered almost as desirable as Cardiff, but Amsterdam is a long way behind Bangkok, relatively speaking. Or else perhaps Bangkok is only marginally better than Amsterdam, compared to the extent to which Cardiff is better than Bangkok. This kind of information about the relative distance between options, in terms of strength of preference or desirability, is precisely what is given by an interval-valued utility function. The problem is how to ascertain this information.
To solve this problem, Ramsey (1926) and later von Neumann and Morgenstern (hereafter vNM) made the following suggestion: we construct a new option, a lottery, $$L$$, that has $$A$$ and $$C$$ as its possible “prizes”, and we figure out what chance the lottery must confer on $$C$$ for you to be indifferent between this lottery and a holiday in Bangkok. The basic idea is that your judgment about Bangkok, relative to Cardiff on the one hand and Amsterdam on the other, can be measured by the riskiness of the lottery $$L$$ involving Cardiff and Amsterdam that you deem equally desirable as Bangkok. For instance, if you are indifferent between Bangkok and a lottery that provides a very low chance of winning a trip to Cardiff, then you evidently do not regard Bangkok to be much better than Amsterdam, vis-à-vis Cardiff; for you, even a small improvement on Amsterdam, i.e., a lottery with a small chance of Cardiff rather than Amsterdam, is enough to match Bangkok.
The above analysis presumes that lotteries are evaluated in terms of their expected choice-worthiness or desirability. That is, the desirability of a lottery is effectively the sum of the chances of each prize multiplied by the desirability of that prize. Consider the following example: Suppose you are indifferent between the lottery and the holiday in Bangkok when the chance of the lottery resulting in a holiday in Cardiff is $$3/4$$. Call this particular lottery $$L'$$. The idea is that Bangkok is therefore three quarters of the way up a desirability scale that has Amsterdam at the bottom and Cardiff at the top. If we stipulate that $$u(A)=0$$ and $$u(C)=1$$, then $$u(B)=u(L')=3/4$$. This corresponds to the expected desirability—or, as it is usually called, the expected utility—of the lottery, since $$1/4\cdot 0 + 3/4\cdot 1 = 3/4 = u(L')$$. That is, the desirability of the lottery is a probability weighted sum of the utilities of its prizes, where the weight on each prize is determined by the probability that the lottery results in that prize.
We thus see that an interval-valued utility measure over options can be constructed by introducing lottery options. As the name suggests, the interval-valued utility measure conveys information about the relative sizes of the intervals between the options according to some desirability scale. That is, the utilities are unique after we have fixed the starting point of our measurement and the unit scale of desirability. In the above example, we could have, for instance, assigned a utility value of 1 to $$A$$ and 5 to $$C$$, in which case we would have had to assign a utility value of 4 to $$B$$, since 4 is 3/4 of the way between 1 and 5. In other words, once we have assigned utility values to $$A$$ and $$C$$, the utility of $$L'$$ and thus $$B$$ has been determined. Let us call this second utility function $$u'$$. It is related to our original function as follows: $$u'=4\cdot u +1$$. This relationship always holds between two such functions: If $$u$$ is an interval-valued utility function that represents a preference ordering, $$\preceq$$, and $$u'$$ is another utility function that also represents this same preference ordering, then there are constants $$a$$ and $$b$$, where $$a$$ must be positive, such that $$u'=a\cdot u + b$$. This is to say that interval-valued utility functions are unique only up to positive linear transformation.
Before concluding this discussion of measuring utility, two related limitations regarding the information such measures convey should be mentioned. First, since the utilities of options, whether ordinal or interval-valued, can only be determined relative to the utilities of other options, there is no such thing as the absolute utility of an option, at least not without further assumptions.[2] Second, by the same reasoning, neither interval-valued nor ordinal utility measures, as discussed here, are interpersonally commensurable with respect to levels and units of utility. By way of a quick illustration, suppose that both you and I have the preference ordering described above over the holiday options: $$A\prec B \prec C$$. Suppose too that, as per the above, we are both indifferent between $$B$$ and the lottery $$L'$$ that has a $$3/4$$ chance of yielding $$C$$ and a $$1/4$$ chance of yielding $$A$$. Can we then say that granting me Cardiff and you Bangkok would amount to the same amount of “total desirability” as granting you Cardiff and me Bangkok? We are not entitled to say this. Our shared preference ordering is, for instance, consistent with me finding a vacation in Cardiff a dream come true while you just find it the best of a bad lot. Moreover, we are not even entitled to say that the difference in desirability between Bangkok and Amsterdam is the same for you as it is for me. According to me, the desirability of the three options might range from living hell to a dream come true, while according to you, from bad to quite bad; both evaluations are consistent with the above preference ordering. In fact, the same might hold for our preferences over all possible options, including lotteries: even if we shared the same total preference ordering, it might be the case that you are just of a negative disposition—finding no option that great—while I am very extreme—finding some options excellent but others a sheer torture. Hence, utility functions, whether interval-valued or ordinal, do not allow for meaningful interpersonal comparisons. (Elster and Roemer 1993 contains a number of papers discussing these issues; see also the entry on social choice theory.)
### 2.3 The von Neumann and Morgenstern (vNM) representation theorem
The last section provided an interval-valued utility representation of a person’s preferences over lotteries, on the assumption that lotteries are evaluated in terms of expected utility. Some might find this a bit quick. Why should we assume that people evaluate lotteries in terms of their expected utilities? The vNM theorem effectively shores up the gaps in reasoning by shifting attention back to the preference relation. In addition to Transitivity and Completeness, vNM introduce further principles governing rational preferences over lotteries, and show that an agent’s preferences can be represented as maximising expected utility whenever her preferences satisfy these principles.
Let us first define, in formal terms, the expected utility of a lottery: Let $$L_i$$ be a lottery from the set $$\bL$$ of lotteries, and $$O_{ik}$$ the outcome, or prize, of lottery $$L_i$$ that arises with probability $$p_{ik}$$. The expected utility of $$L_i$$ is then defined as:
The vNM equation.
$EU(L_i) \mathbin{\dot{=}} \sum_k u(O_{ik}) \cdot p_{ik}$
The assumption made earlier can now be formally stated:
$$\tag{2} \text{For any}\ L_i, L_j\in \bL: L_i\preceq L_j\Leftrightarrow EU(L_i)\leq EU(L_j)$$
When the above holds, we say that there is an expected utility function that represents the agent’s preferences; in other words, the agent can be represented as maximising expected utility.
The question that vNM address is: What sort of preferences can be thus represented? To answer this question, we must return to the underlying preference relation $$\preceq$$ over the set of options, in this case involving lotteries. The vNM theorem requires the set $$\bL$$ of lotteries to be rather extensive: it is closed under “probability mixture”, that is, if $$L_i, L_j\in \bL$$, then compound lotteries that have $$L_i$$ and $$L_j$$ as possible prizes are also in $$\bL$$. (Another technical assumption, that will not be discussed in detail, is that compound lotteries can always be reduced, in accordance with the laws of probability, to simple lotteries that only involve basic prizes.)
A basic rationality constraint on the preference relation has already been discussed—that it weakly orders the options (i.e., satisfies Transitivity and Completeness). The following notation will be used to introduce the two additional vNM axioms of preference: $$\{pA, (1-p)B\}$$ denotes a lottery that results either in $$A$$, with probability $$p$$, or $$B$$, with probability $$1-p$$, where $$A$$ and $$B$$ can be final outcomes but can also be lotteries.
Axiom 3 (Continuity)
Suppose $$A\preceq B\preceq C$$. Then there is a $$p\in [0,1]$$ such that:
$\{pA, (1-p)C\}\sim B$
Axiom 4 (Independence)
Suppose $$A\preceq B$$. Then for any $$C$$, and any $$p\in [0,1]$$:
$\{pA, (1-p)C\}\preceq \{pB, (1-p)C\}$
Continuity implies that no outcome $$A$$ is so bad that you would not be willing to take some gamble that might result in you ending up with that outcome, but might otherwise result in you ending up with an outcome ($$C$$) that you find to be a marginal improvement on your status quo ($$B$$), provided that the chance of $$A$$ is small enough. Intuitively, Continuity guarantees that an agent’s evaluations of lotteries are appropriately sensitive to the probabilities of the lotteries’ prizes.
Independence implies that when two alternatives have the same probability for some particular outcome, our evaluation of the two alternatives should be independent of our opinion of that outcome. Intuitively, this means that preferences between lotteries should be governed only by the features of the lotteries that differ; the commonalities between the lotteries should be effectively ignored.
Some people find the Continuity axiom an unreasonable constraint on rational preference. Is there any probability $$p$$ such that you would be willing to accept a gamble that has that probability of you losing your life and probability $$(1-p)$$ of you gaining $10? Many people think there is not. However, the very same people would presumably cross the street to pick up a$10 bill they had dropped. But that is just taking a gamble that has a very small probability of being killed by a car but a much higher probability of gaining $10! More generally, although people rarely think of it this way, they constantly take gambles that have minuscule chances of leading to imminent death, and correspondingly very high chances of some modest reward. Independence seems a compelling requirement of rationality, when considered in the abstract. Nevertheless, there are famous examples where people often violate Independence without seeming irrational. These examples involve complementarities between the possible lottery outcomes. A particularly well-known such example is the so-called Allais Paradox, which the French economist Maurice Allais (1953) first introduced in the early 1950s. The paradox turns on comparing people’s preferences over two pairs of lotteries similar to those given in Table 1. The lotteries are described in terms of the prizes that are associated with particular numbered tickets, where one ticket will be drawn randomly (for instance, $$L_1$$ results in a prize of$2500 if one of the tickets numbered 2–34 is drawn).
1 2–34 35–100 $$L_1$$ $0$2500 $2400 $$L_2$$$2400 $2400$2400
1 2–34 35–100 $$L_3$$ $0$2500 $0 $$L_4$$$2400 $2400$0
In this situation, many people strictly prefer $$L_2$$ over $$L_1$$ but also $$L_3$$ over $$L_4$$ (as evidenced by their choice behaviour, as well as their testimony), a pair of preferences which will be referred to as Allais’ preferences.[3] A common way to rationalise Allais’ preferences, is that in the first choice situation, the risk of ending up with nothing when one could have had $2400 for sure does not justify the increased chance of a higher prize. In the second choice situation, however, the minimum one stands to gain is$0 no matter which choice one makes. Therefore, in that case many people do think that the slight extra risk of 0 is worth the chance of a better prize. While the above reasoning may seem compelling, Allais’ preferences conflict with the Independence axiom. The following is true of both choice situations: whatever choice you make, you will get the same prize if one of the tickets in the last column is drawn. Therefore, Independence implies that both your preference between $$L_1$$ and $$L_2$$ and your preference between $$L_3$$ and $$L_4$$ should be independent of the prizes in that column. But when you ignore the last column, $$L_1$$ becomes identical to $$L_3$$ and $$L_2$$ to $$L_4$$. Hence, if you prefer $$L_2$$ over $$L_1$$ but $$L_3$$ over $$L_4$$, there seems to be an inconsistency in your preference ordering. And there is definitely a violation of Independence (given how the options have been described; an issue to which we return in Section 5.1). As a result, the pair of preferences under discussion cannot be represented as maximising expected utility. (Thus the “paradox”: many people think that Independence is a requirement of rationality, but nevertheless also want to claim that there is nothing irrational about Allais’ preferences.) Decision theorists have reacted in different ways to Allais’ Paradox. This issue will be revisited in Section 5.1, when challenges to EU theory will be discussed. The present goal is simply to show that Continuity and Independence are compelling constraints on rational preference, although not without their detractors. The result vNM proved can be summarised thus: Theorem 2 (von Neumann-Morgenstern) Let $$\bO$$ be a finite set of outcomes, $$\bL$$ a set of corresponding lotteries that is closed under probability mixture and $$\preceq$$ a weak preference relation on $$\bL$$. Then $$\preceq$$ satisfies axioms 1–4 if and only if there exists a function $$u$$, from $$\bO$$ into the set of real numbers, that is unique up to positive linear transformation, and relative to which $$\preceq$$ can be represented as maximising expected utility. David Kreps (1988) gives an accessible illustration of the proof of this theorem. ## 3. Making real decisions The vNM theorem is a very important result for measuring the strength of a rational agent’s preferences over sure options (the lotteries effectively facilitate a cardinal measure over sure options). But this does not get us all the way to making rational decisions in the real world; we do not yet really have a decision theory. The theorem is limited to evaluating options that come with a probability distribution over outcomes—a situation decision theorists and economists often describe as “choice under risk” (Knight 1921). In most ordinary choice situations, the objects of choice, over which we must have or form preferences, are not like this. Rather, decision-makers must consult their own probabilistic beliefs about whether one outcome or another will result from a specified option. Decisions in such circumstances are often described as “choices under uncertainty” (Knight 1921). For example, consider the predicament of a mountaineer deciding whether or not to attempt a dangerous summit ascent, where the key factor for her is the weather. If she is lucky, she may have access to comprehensive weather statistics for the region. Nevertheless, the weather statistics differ from the lottery set-up in that they do not determine the probabilities of the possible outcomes of attempting versus not attempting the summit on a particular day. Not least, the mountaineer must consider how confident she is in the data-collection procedure, whether the statistics are applicable to the day in question, and so on, when assessing her options in light of the weather. Some of the most celebrated results in decision theory address, to some extent, these challenges. They consist in showing what conditions on preferences over “real world options” suffice for the existence of a pair of utility and probability functions relative to which the agent can be represented as maximising expected utility. The standard interpretation is that, just as the utility function represents the agent’s desires, so the probability function represents her beliefs. The theories are referred to collectively as subjective expected utility (SEU) theory as they concern an agent’s preferences over prospects that are characterised entirely in terms of her own beliefs and desires (but we will continue to use the simpler label EU theory). In this section, two of these results will be briefly discussed: that of Leonard Savage (1954) and Richard Jeffrey (1965). Note that these EU decision theories apparently prescribe two things: (a) you should have consistent preference attitudes, and (b) you should prefer the means to your ends, or at least you should prefer the means that you assess will on average lead to your ends (cf. Buchak 2016). The question arises: What is the relationship between these prescriptions? The EU representation theorems that will be outlined shortly seem to show that, despite appearances, the two prescriptions are actually just one: anyone who has consistent attitudes prefers the means to her ends, and vice versa. But the puzzle remains that there are many ways to have consistent preference attitudes, and surely not all of these amount to preferring the means to one’s own true ends. This puzzle is worth bearing in mind when appraising EU theory in its various guises; it will come up again later. ### 3.1 Savage’s theory Leonard Savage’s decision theory, as presented in his (1954) The Foundations of Statistics, is without a doubt the best-known normative theory of choice under uncertainty, in particular within economics and the decision sciences. In the book Savage presents a set of axioms constraining preferences over a set of options that guarantee the existence of a pair of probability and utility functions relative to which the preferences can be represented as maximising expected utility. Nearly three decades prior to the publication of the book, Frank P. Ramsey (1926) had actually proposed that a different set of axioms can generate more or less the same result. Nevertheless, Savage’s theory has been much more influential than Ramsey’s, perhaps because Ramsey neither gave a full proof of his result nor provided much detail of how it would go (Bradley 2004). Savage’s result will not be described here in full detail. However, the ingredients and structure of his theorem will be laid out, highlighting its strengths and weaknesses. The options or prospects in Savage’s theory are similar to lotteries, except that the possible outcomes do not come with probabilities but rather depend on whether a particular state of the world is actual. Indeed, the primitives in Savage’s theory are outcomes[4] and states (of the world). The former are the good or bad states of affairs that ultimately affect and matter to an agent, while the latter are the features of the world that the agent has no control over and which are the locus of her uncertainty about the world. Sets of states are called events. This distinction between outcomes and states serves to neatly separate desire and belief: the former are, according to Savage’s theory, the target of desire, while the latter are the target of belief. The lottery-like options over which the agent has preferences are a rich set of acts that effectively amount to all the possible assignments of outcomes to states of the world. That is, acts are functions from the state space to the outcome space, and the agent’s preference ordering is taken to be defined over all such possible functions. Some of these acts will look quite sensible: consider the act that assigns to the event “it rains” the outcome “miserable wet stroll” and assigns to the event “it does not rain” the outcome “very comfortable stroll”. This is apparently the act of going for a stroll without one’s umbrella. Other Savage acts will not look quite so sensible, such as the constant act that assigns to both “it rains” and “it does not rain” the same outcome “miserable wet stroll”. (Note that the constant acts provide a way of including sure outcomes within the preference ordering.) The problem with this act (and many others) is that it does not correspond to anything that an agent could even in principle choose to do or perform.[5] Savage’s act/state(event)/outcome distinction can be naturally represented in tabular form, with rows serving as acts that yield a given outcome for each state/event column. Table 2 depicts the two acts mentioned above plus a third one that the decision maker might care about: the acts i) “go for stroll without umbrella”, ii) “go for stroll with umbrella”, and iii) the bizarre constant act. Of course, the set of acts required for Savage’s theorem involve even more acts that account for all the possible combinations of states and outcomes. no rain rain stroll without umbrella very comfortable stroll miserable wet stroll stroll with umbrella comfortable stroll comfortable stroll constant act miserable wet stroll miserable wet stroll Table 2. Savage-style decision table Before discussing Savage’s axioms, let us state the result that they give rise to. The following notation will be used: $$f$$, $$g$$, etc, are various acts, i.e., functions from the set $$\bS$$ of states of the world to the set $$\bO$$ of outcomes, with $$\bF$$ the set of these functions. $$f(s_i)$$ denotes the outcome of $$f$$ when state $$s_i\in\bS$$ is actual. The expected utility of $$f$$, according to Savage’s theory, denoted $$U(f)$$, is given by: Savage’s equation $$U(f)=\sum_i u(f(s_i))\cdot P(s_i)$$ The result Savage proved can be stated as follows:[6] Theorem 3 (Savage). Let $$\preceq$$ be a weak preference relation on $$\bF$$. If $$\preceq$$ satisfies Savage’s axioms, then the following holds: • The agent’s confidence in the actuality of the states in $$\bS$$ can be represented by a unique (and finitely additive) probability function, $$P$$; • the strength of her desires for the ultimate outcomes in $$\bO$$ can be represented by a utility function, $$u$$, that is unique up to positive linear transformation; • and the pair $$(P, u)$$ gives rise to an expected utility function, $$U$$, that represents her preferences for the alternatives in $$\bF$$; i.e., for any $$f, g\in\bF$$: $f\preceq g\Leftrightarrow U(f)\leq U(g)$ The above result may seem remarkable; in particular, the fact that a person’s preferences can determine a unique probability function that represents her beliefs. On a closer look, however, it is evident that some of our beliefs can be determined by examining our preferences. Suppose you are offered a choice between two lotteries, one that results in you winning a nice prize if a coin comes up heads but getting nothing if the coin comes up tails, another that results in you winning the same prize if the coin comes up tails but getting nothing if the coin comes up heads. Then assuming that the desirability of the prize (and similarly the desirability of no prize) is independent of how the coin lands, your preference between the two lotteries should be entirely determined by your comparative beliefs for the two ways in which the coin can land. For instance, if you strictly prefer the first lottery to the second, then that suggests you consider heads more likely than tails. The above observation suggests that one can gauge an agent’s comparative beliefs, and perhaps more, from her preferences. Savage went one step further than this, and defined comparative beliefs in terms of preferences. To state Savage’s definition, let $$\wcbrel$$ be a weak comparative belief relation, defined on the set $$\bS$$ of states of the world. ($$\cbrel$$ and $$\wcbsim$$ are defined in terms of $$\wcbrel$$ in the usual way.) Definition 1 (Comparative Belief). Suppose $$E$$ and $$F$$ are two events (i.e., subsets of $$\bS$$). Suppose $$X$$ and $$Y$$ are two outcomes and $$f$$ and $$g$$ two acts, with the following properties: • $$f(s_i)=X$$ for all $$s_i\in E$$, but $$f(s_i)=Y$$ for all $$s_i\not\in E$$, • $$g(s_i)=X$$ for all $$s_i\in F$$, but $$g(s_i)=Y$$ for all $$s_i\not\in F$$, • $$Y\preceq X$$. Then $$E \wcbrel F\Leftrightarrow f\preceq g$$. Definition 1 is based on the simple observation that one would generally prefer to stake a good outcome on a more rather than less probable event. But the idea that this defines comparative beliefs might seem questionable. We could, for instance, imagine people who are instrumentally irrational, and as a result fail to prefer $$g$$ to $$f$$, even when the above conditions all hold and they find $$F$$ more likely than $$E$$. Moreover, this definition raises the question of how to define the comparative beliefs of those who are indifferent between all outcomes (Eriksson and Hájek 2007). Perhaps no such people exist (and Savage’s axiom P5 indeed makes clear that his result does not pertain to such people). Nevertheless, it seems a definition of comparative beliefs should not preclude that such people, if existent, have strict comparative beliefs. Savage suggests that this definition of comparative beliefs is plausible in light of his axiom P4, which will be stated below. In any case, it turns out that when a person’s preferences satisfy Savage’s axioms, we can read off her preferences a comparative belief relation that can be represented by a (unique) probability function. Without further ado, let us state Savage’s axioms in turn. These are intended as constraints on an agent’s preference relation, $$\preceq$$, over a set of acts, $$\bF$$, as described above. The first of Savage’s axioms is the basic ordering axiom. P1. (Ordering) The relation $$\preceq$$ is complete and transitive. The next axiom is reminiscent of vNM’s Independence axiom. We say that alternative $$f$$ “agrees with” $$g$$ in event $$E$$ if, for any state in event $$E$$, $$f$$ and $$g$$ yield the same outcome. P2. (Sure Thing Principle) If $$f$$, $$g$$, and $$f'$$, $$g'$$ are such that: • $$f$$ agrees with $$g$$ and $$f'$$ agrees with $$g'$$ in event $$\neg E$$, • $$f$$ agrees with $$f'$$ and $$g$$ agrees with $$g'$$ in event $$E$$, • and $$f\preceq g$$, then $$f'\preceq g'$$. The idea behind the Sure Thing Principle (STP) is essentially the same as that behind Independence: since we should be able to evaluate each outcome independently of other possible outcomes, we can safely ignore states of the world where two acts that we are comparing result in the same outcome. Putting the principle in tabular form may make this more apparent. The setup involves four acts with the following form: $$E$$ $$\neg E$$ $$f$$ X Z $$g$$ Y Z $$f'$$ X W $$g'$$ Y W The intuition behind the STP is that if $$g$$ is weakly preferred to $$f$$, then that must be because the consequence $$Y$$ is considered at least as desirable as $$X$$, which by the same reasoning implies that $$g'$$ is weakly preferred to $$f'$$. Savage also requires that the desirability of an outcome be independent of the state in which it occurs, as this is necessary for it to be possible to determine a comparative belief relation from an agent’s preferences. To formalise this requirement, Savage introduces the notion of a null event, defined as follows: Definition 2 (Null) Event E is null just in case for any alternatives $$f,g\in\bF$$, $$f\sim g$$ given E. The intuition is that null events are those events an agent is certain will not occur. If and only if an agent is certain that $$E$$ will not occur, then it is of indifference to her what the acts before her yield under $$E$$. The following axiom then stipulates that knowing what state is actual does not affect the preference ordering over outcomes: P3. (State Neutrality) If $$f(s_i)=X$$ and $$g(s_i)=Y$$ whenever $$s_i\in E$$ and $$E$$ is not null, then $$f\preceq g$$ given $$E$$ just in case $$X\preceq Y$$. The next axiom is also necessary for it to be possible to determine a comparative belief relation from an agent’s preferences. Above it was suggested that by asking you to stake a prize on whether a coin comes up heads or tails, it can be determined which of these events, heads or tails, you find more likely. But that suggestion is only plausible if the size of the prize does not affect your judgement of the relative likelihood of these two events. That assumption is captured by the next axioms. Since the axiom is rather complicated it will be stated in tabular form: P4. Consider the following acts: $$E$$ $$\neg E$$ $$f$$ $$X$$ $$X'$$ $$g$$ $$Y$$ $$Y'$$ $$F$$ $$\neg F$$ $$f'$$ $$X$$ $$X'$$ $$g'$$ $$Y$$ $$Y'$$ Now suppose: \begin{align} X' &\preceq X, \\ Y' &\preceq Y, \\ f' &\preceq f \end{align} Then $g'\preceq g.$ Less formally (and stated in terms of strict preference), the idea is that if you prefer to stake the prize $$X$$ on $$f$$ rather than $$f'$$, you must consider $$E$$ more probable than $$F$$. Therefore, you should prefer to stake the prize $$Y$$ on $$g$$ rather than $$g'$$ since the prize itself does not affect the probability of the events. The next axiom is arguably not a rationality requirement, but one of Savage’s “structural axioms” (Suppes 2002). An agent needs to have some variation in preference for it to be possible to read off her comparative beliefs from her preferences; and, more generally, for it to be possible to represent her as maximising expected utility. To this end, the next axiom simply requires that there be some alternatives between which the agent is not indifferent: P5. There are some $$f,g\in\bF$$ such that $$f\prec g$$. When these five axioms are satisfied, the agent’s preferences give rise to a comparative belief relation, $$\wcbrel$$, which has the property of being a qualitative probability relation, which is necessary for it to be possible to represent $$\wcbrel$$ by a probability function. In other words, $$\wcbrel$$ satisfies the following three conditions, for any events $$E$$, $$F$$ and $$G$$: 1. $$\wcbrel$$ is transitive and complete, 2. if $$E\cap G=\emptyset=F\cap G$$, then $$E \wcbrel F\Leftrightarrow E\cup G \wcbrel F\cup G$$, 3. $$\emptyset \wcbrel E,$$ $$\emptyset \cbrel \bS$$ Being a qualitative probability relation is, however, not sufficient to ensure the possibility of probabilistic representation. To ensure this possibility, Savage added the following structural axiom: P6. (Non-atomicity) Suppose $$f\prec g$$. Then for any $$X\in\bO$$, there is a finite partition, $$\{E_1, E_2, … E_m\}$$, of $$\bS$$ such that: • $$f'(s_i)=X$$ for any $$s_i\in E_j$$, but $$f'(s_i)=f(s_i)$$ for any $$s_i\not\in E_j$$, • $$g'(s_i)=X$$ for any $$s_i\in E_j$$, but $$g'(s_i)=g(s_i)$$ for any $$s_i\not\in E_j$$, • $$f'\prec g$$ and $$f\prec g'$$. Like the Continuity axiom of vNM, Non-Atomicity implies that no matter how bad an outcome $$X$$ is, if $$g$$ is already preferred to $$f$$, then if we add $$X$$ as one of the possible outcomes of $$f$$—thereby constructing a new alternative $$f'$$—$$g$$ will still be preferred to the modified alternative as long as the probability of $$X$$ is sufficiently small. In effect, Non-Atomicity implies that $$\bS$$ contains events of arbitrarily small probability. It is not too difficult to imagine how that could be satisfied. For instance, any event $$F$$ can be partitioned into two equiprobable sub-events according to whether some coin would come up heads or tails if it were tossed. Each sub-event could be similarly partitioned according to the outcome of the second toss of the same coin, and so on. Savage showed that whenever these six axioms are satisfied, the comparative belief relation can be represented by a unique probability function. Having done so, he could rely on the vNM representation theorem to show that an agent who satisfies all six axioms[7] can be represented as maximising expected utility, relative to a unique probability function that plausibly represents the agent’s beliefs over the states and a cardinal utility function that plausibly represents the agent’s desires for ultimate outcomes (recall the statement of Savage’s theorem above).[8] Savage’s own proof is rather complicated, but Kreps (1988) provides a useful illustration of it. There is no doubt that Savage’s expected utility representation theorem is very powerful. There are, however, two important questions to ask about whether Savage achieves his aims: 1) Does Savage characterise rational preferences, at least in the generic sense? And 2) Does Savage’s theorem tell us how to make rational decisions in the real world? Savage’s theory has problems meeting these two demands, taken together. Arguably the core weakness of the theory is that its various constraints and assumptions pull in different directions when it comes to constructing realistic decision models, and furthermore, at least one constraint (notably, the Sure Thing Principle) is only plausible under decision modelling assumptions that are supposed to be the output, not the input, of the theory. One well recognised decision-modelling requirement for Savage’s theory is that outcomes be maximally specific in every way that matters for their evaluation. If this were not the case, the axiom of State Neutrality, for instance, would be a very implausible rationality constraint. Suppose we are, for example, wondering whether to buy cocoa or lemonade for the weekend, and assume that how good we find each option depends on what the weather will be like. Then we need to describe the outcomes such that they include the state of the weather. For if we do not, the desirability of the outcomes will depend on what state is actual. Since lemonade is, let us suppose, better on hot days than cold, an outcome like “I drink lemonade this weekend” would be more or less desirable depending on whether it occurs in a state where it is hot or cold. This would be contrary to the axiom of State Neutrality. Therefore, the appropriate outcomes in this case are those of the form “I drink lemonade this weekend in hot weather”. (Of course, this outcome must be split into even more fine-grained outcomes if there are yet further features that would affect the choice at hand, such as sharing the drink with a friend who loves lemonade versus sharing the drink with a friend who loves hot cocoa, and so on.) The fact that the outcomes in the above case must be specific enough to contain the state of the weather may seem rather innocuous. However, this requirement exacerbates the above-mentioned problem that many of the options/acts that Savage requires for his representation theorem are nonsensical, in that the semantic content of state/outcome pairs is contradictory. Recall that the domain of the preference ordering in Savage’s theory amounts to every function from the set of states to the set of outcomes (what Broome 1991a refers to as the Rectangular Field Assumption). So if “I drink lemonade this weekend in hot weather” is one of the outcomes we are working with, and we have partitioned the set of states according to the weather, then there must, for instance, be an act that has this outcome in the state where it is cold! The more detailed the outcomes (as required for the plausibility of State Neutrality), the less plausible the Rectangular Field Assumption. This is an internal tension in Savage’s framework. Indeed, it is difficult to see how/why a rational agent can/should form preferences over nonsensical acts (although see Dreier 1996 for an argument that this is not such an important issue). Without this assumption, however, the agent’s preference ordering will not be adequately rich for Savage’s rationality constraints to yield the EU representation result.[9] The axiom in Savage’s theory that has received most attention is the Sure Thing Principle. It is not hard to see that this principle conflicts with Allais’ preferences for the same reason these preferences conflict with Independence (recall Section 2.3). Allais’ challenge will be discussed again later. For now, our concern is rather the Sure Thing Principle vis-à-vis the internal logic of Savage’s theory. To begin with, the Sure Thing Principle, like State Neutrality, exacerbates concerns about the Rectangular Field Assumption. This is because the Sure Thing Principle is only plausible if outcomes are specific enough to account for any sort of dependencies between outcomes in different states of the world. For instance, if the fact that one could have chosen a risk-free alternative—and thereby guaranteed an acceptable outcome—makes a difference to the desirability of receiving nothing after having taken a risk (as in Allais’ problem), then that has to be accounted for in the description of the outcomes. But again, if we account for such dependencies in the description of the outcomes, we run into the problem that there will be acts in the preference ordering that are nonsensical (see, e.g., Broome 1991a: ch. 5). There is a further internal problem with Savage’s theory associated with the Sure Thing Principle: the principle is only reasonable when the decision model is constructed such that there is probabilistic independence between the acts an agent is considering and the states of the world that determine the outcomes of these acts. Recall that the principle states that if we have four options with the following form: $$E$$ $$\neg E$$ $$f$$ X Z $$g$$ Y Z $$f'$$ X W $$g'$$ Y W then if $$g$$ is weakly preferred to $$f$$, $$g'$$ must be weakly preferred to $$f'$$. Suppose, however, that there is probabilistic dependency between the states of the world and the alternatives we are considering, and that we find $$Z$$ to be better than both $$X$$ and $$Y$$, and we also find $$W$$ to be better than both $$X$$ and $$Y$$. Moreover, suppose that $$g$$ makes $$\neg E$$ more likely than $$f$$ does, and $$f'$$ makes $$\neg E$$ more likely than $$g'$$ does. Then it seems perfectly reasonable to prefer $$g$$ over $$f$$ but $$f'$$ over $$g'$$. Why is the requirement of probabilistic independence problematic? For one thing, in many real-world decision circumstances, it is hard to frame the decision model in such a way that states are intuitively probabilistically independent of acts. For instance, suppose an agent enjoys smoking, and is trying to decide whether to quit or not. How long she lives is amongst the contingencies that affect the desirability of smoking. It would be natural to partition the set of states according to how long the agent lives. But then it is obvious that the options she is considering could, and arguably should, affect how likely she finds each state of the world, since it is well recognised that life expectancy is reduced by smoking. Savage would thus require an alternative representation of the decision problem—the states do not reference life span directly, but rather the agent’s physiological propensity to react in a certain way to smoking. Perhaps there is always a way to contrive decision models such that acts are intuitively probabilistically independent of states. But therein lies the more serious problem. Recall that Savage was trying to formulate a way of determining a rational agent’s beliefs from her preferences over acts, such that the beliefs can ultimately be represented by a probability function. If we are interested in real-world decisions, then the acts in question ought to be recognisable options for the agent (which we have seen is questionable). Moreover, now we see that one of Savage’s rationality constraints on preference—the Sure Thing Principle—is plausible only if the modelled acts are probabilistically independent of the states. In other words, this independence must be built into the decision model if it is to facilitate appropriate measures of belief and desire. But this is to assume that we already have important information about the beliefs of the agent whose attitudes we are trying to represent; namely what state-partitions she considers probabilistically independent of her acts. The above problems suggest there is a need for an alternative theory of choice under uncertainty. Richard Jeffrey’s theory, which will be discuss next, avoids all of the problems that have been discussed so far. But as we will see, Jeffrey’s theory has well-known problems of its own, albeit problems that are not insurmountable. ### 3.2 Jeffrey’s theory Richard Jeffrey’s expected utility theory differs from Savage’s in terms of both the prospects (i.e., options) under consideration and the rationality constraints on preferences over these prospects. The distinct advantage of Jeffrey’s theory is that real-world decision problems can be modelled just as the agent perceives them; the plausibility of the rationality constraints on preference do not depend on decision problems being modelled in a particular way. We first describe the prospects or decision set-up and the resultant expected utility rule, before turning to the pertinent rationality constraints on preferences and the corresponding theorem. Unlike Savage, Jeffrey does not make a distinction between the objects of instrumental and non-instrumental desire (acts and outcomes respectively) and the objects of belief (states of the world). Rather, Jeffrey assumes that propositions describing states of affairs are the objects of both desire and belief. On first sight, this seems unobjectionable: just as we can have views about whether it will in fact rain, we can also have views about how desirable that would be. The uncomfortable part of this setup is that acts, too, are just propositions—they are ordinary states of affairs about which an agent has both beliefs and desires. Just as the agent has a preference ordering over, say, possible weather scenarios for the weekend, she has a preference ordering over the possible acts that she may perform, and in neither case is the most preferred state of affairs necessarily the most likely to be true. In other words, the only thing that picks out acts as special is their substantive content—these are the propositions that the agent has the power to choose/make true in the given situation. It is as if the agent assesses her own options for acting from, rather, a third-person perspective. If one holds that a decision model should convincingly represent the subjective perspective of the agent in question, this is arguably a weakness of Jeffrey’s theory, although it may be one without consequence.[10] Before proceeding, a word about propositions may be helpful: they are abstract objects that can be either true or false, and are commonly identified with sets of possible worlds. A possible world can be thought of as an abstract representation of how things are or could be (Stalnaker 1987; see also entry on possible worlds). The proposition that it rains at time $$t$$, for example, is just the set of all worlds where it rains at time $$t$$. And this particular proposition is true just in case the actual world happens to be a member of the set of all worlds where it rains at time $$t$$. The basic upshot of Jeffrey’s theory is that the desirability of a proposition, including one representing acts, depends both on the desirabilities of the different ways in which the proposition can be true, and the relative probability that it is true in these respective ways. To state this more precisely, $$p$$, $$q$$, etc., will denote propositional variables. Let $$\{p_1, p_2, …, p_n\}$$ be one amongst many finite partitions of the proposition $$p$$; that is, sets of mutually incompatible but jointly exhaustive ways in which the proposition $$p$$ can be realised. For instance, if $$p$$ is the proposition that it is raining, then we could partition this proposition very coarsely according to whether we go to the beach or not, but we could also partition $$p$$ much more finely, for instance according to the precise millimetres-per-hour amount of rain. The desirability of $$p$$ according to Jeffrey, denoted $$Des(p)$$, is given by: Jeffrey’s equation. $$Des(p)=\sum_i Des(p_i)\cdot P(p_i\mid p)$$ This is effectively a conditional expected utility formula for evaluating $$p$$. As noted, a special case is when the content of $$p$$ is such that it is recognisably something the agent can choose to make true, i.e., an act. One important difference between Jeffrey’s desirability formula and Savage’s expected utility formula, is that there is no distinction made between desirability and “expected” desirability, unlike what has to be done in Savage’s theory, where there is a clear distinction between utility, measuring an agent’s fundamental desires for ultimate outcomes, and expected utility, measuring an agent’s preferences over uncertain prospects or acts. This disanalogy is due to the fact that there is no sense in which the $$p_i$$s that $$p$$ is evaluated in terms of need to be ultimate outcomes; they can themselves be thought of as uncertain prospects that are evaluated in terms of their different possible realisations. Another important thing to notice about Jeffrey’s way of calculating desirability, is that it does not assume probabilistic independence between the alternative that is being evaluated, $$p$$, and the possible ways, the $$p_i$$s, that the alternative may be realised. Indeed, the probability of each $$p_i$$ is explicitly conditional on the $$p$$ in question. When it comes to evaluating acts, this is to say (in Savage’s terminology) that the probabilities for the possible state-outcome pairs for the act are conditional on the act in question. Thus we see why the agent can describe her decision problem just as she sees it; there is no requirement that she identify a set of states (in Jeffrey’s case, this would be a partition of the proposition space that is orthogonal to the act partition) such that the states are appropriately fine-grained and probabilistically independent of the acts. It should moreover be evident, given the discussion of the Sure Thing Principle (STP) in Section 3.1, that Jeffrey’s theory does not have this axiom. Since states may be probabilistically dependent on acts, an agent can be represented as maximising the value of Jeffrey’s desirability function while violating the STP. Moreover, unlike Savage’s, Jeffrey’s representation theorem does not depend on anything like the Rectangular Field Assumption. The agent is not required to have preferences over artificially constructed acts or propositions that turn out to be nonsensical, given the interpretation of particular states and outcomes. In fact, only those propositions the agent considers to be possible (in the sense that she assigns them a probability greater than zero) are, according to Jeffrey’s theory, included in her preference ordering. Of course, we still need certain structural assumptions in order to prove a representation theorem for Jeffrey’s theory. In particular, the set $$\Omega$$, on which the preference ordering $$\preceq$$ is defined, has to be an atomless Boolean algebra of propositions, from which the impossible propositions, denoted $$\bot$$, have been removed. A Boolean algebra is just a set of e.g. propositions or sentences that is closed under the classical logical operators and negation. An algebra is atomless just in case all of its elements can be partitioned into finer elements. The assumption that $$\Omega$$ is atomless is thus similar to Savage’s P6, and can be given a similar justification: any way $$p_i$$ in which $$p$$ can be true can be partitioned into two further propositions according to how some coin would land if tossed. So under what conditions can a preference relation $$\preceq$$ on the set $$\Omega$$ be represented as maximising desirability? Some of the required conditions on preference should be familiar by now and will not be discussed further. In particular, $$\preceq$$ has to be transitive, complete and continuous (recall our discussion in Section 2.3 of vNM’s Continuity preference axiom). The next two conditions are, however, not explicitly part of the two representation theorems that have been considered so far: Averaging If $$p,\ q\in \Omega$$ are mutually incompatible, then $p\preceq q\Leftrightarrow p\preceq p\cup q\preceq q$ Impartiality Suppose $$p,\ q\in \Omega$$ are mutually incompatible and $$p\sim q$$. Then if $$p\cup r\sim q\cup r$$ for some $$r$$ that is mutually incompatible with both $$p$$ and $$q$$ and is such that $$\neg(r\sim p)$$, then $$p\cup r\sim q\cup r$$ for every such $$r$$. Averaging is the distinguishing rationality condition in Jeffrey’s theory. It can actually be seen as a weak version of Independence and the Sure Thing Principle, and it plays a similar role in Jeffrey’s theory. But it is not directly inconsistent with Allais’ preferences, and its plausibility does not depend on the type of probabilistic independence that the STP implies. The postulate requires that no proposition be strictly better or worse than all of its possible realisations, which seems to be a reasonable requirement. When $$p$$ and $$q$$ are mutually incompatible, $$p\cup q$$ implies that either $$p$$ or $$q$$ is true, but not both. Hence, it seems reasonable that $$p\cup q$$ should be neither strictly more nor less desirable than both $$p$$ and $$q$$. Suppose one of $$p$$ or $$q$$ is more desirable than the other. Then since $$p\cup q$$ is compatible with the truth of either the more or the less desirable of the two, $$p\cup q$$’s desirability should fall strictly between that of $$p$$ and that of $$q$$. However, if $$p$$ and $$q$$ are equally desirable, then $$p\cup q$$ should be as desirable as each of the two. The intuitive appeal of Impartiality, which plays a similar role in Jeffrey’s theory as P4 does in Savage’s, is not as great as that of Averaging. Jeffrey himself admitted as much in his comment: The axiom is there because we need it, and it is justified by our antecedent belief in the plausibility of the result we mean to deduce from it. (1965: 147) Nevertheless, it does seem that an argument can be made that any reasonable person will satisfy this axiom. Suppose you are indifferent between two propositions, $$p$$ and $$q$$, that cannot be simultaneously true. And suppose now we find a proposition $$r$$, that is pairwise incompatible with both $$p$$ and $$q$$, and which you find more desirable than both $$p$$ and $$q$$. Then if it turns out that you are indifferent between $$p$$ joined with $$r$$ and $$q$$ joined with $$r$$, that must be because you find $$p$$ and $$q$$ equally probable. Otherwise, you would prefer the union that contains the one of $$p$$ and $$q$$ that you find less probable, since that gives you a higher chance of the more desirable proposition $$r$$. It then follows that for any other proposition $$s$$ that satisfies the aforementioned conditions that $$r$$ satisfies, you should also be indifferent between $$p\cup s$$ and $$q\cup s$$, since, again, the two unions are equally likely to result in $$s$$. The first person to prove a theorem stating sufficient conditions for a preference relation to be representable as maximising the value of a Jeffrey-desirability function was actually not Jeffrey himself, but the mathematician Ethan Bolker (1966, 1967). He proved the following result (recall the definition of a “desirability measure” given above):[11] Theorem 4 (Bolker) Let $$\Omega$$ be a complete and atomless Boolean algebra of propositions, and $$\preceq$$ a continuous, transitive and complete relation on $$\Omega \setminus \bot$$, that satisfies Averaging and Impartiality. Then there is a desirability measure on $$\Omega \setminus \bot$$ and a probability measure on $$\Omega$$ relative to which $$\preceq$$ can be represented as maximising desirability. Unfortunately, Bolker’s representation theorem does not yield a result anywhere near as unique as Savage’s. Even if a person’s preferences satisfy all the conditions in Bolker’s theorem, then it is neither guaranteed that there will be just one probability function that represents her beliefs nor that the desirability function that represents her desires will be unique up to a positive linear transformation (unless her preferences are unbounded). Even worse, the same preference ordering satisfying all these axioms could be represented as maximising desirability relative to two probability functions that do not even agree on how to order propositions according to their probability.[12] For those who think that the only way to determine a person’s comparative beliefs is to look at her preferences, the lack of uniqueness in Jeffrey’s theory is a big problem. Indeed, this may be one of the main reasons why economists have largely ignored Jeffrey’s theory. Economists have traditionally been skeptical of any talk of a person’s desires and beliefs that goes beyond what can be established by examining the person’s preferences, which they take to be the only attitude that is directly revealed by a person’s behaviour. For these economists, it is therefore unwelcome news if we cannot even in principle determine the comparative beliefs of a rational person by looking at her preferences. Those who are less inclined towards behaviourism might, however, not find this lack of uniqueness in Bolker’s theorem to be a problem. James Joyce (1999), for instance, thinks that Jeffrey’s theory gets things exactly right in this regard, since one should not expect that reasonable conditions imposed on a person’s preferences would suffice to determine a unique probability function representing the person’s beliefs. It is only by imposing overly strong conditions, as Savage does, that we can achieve this. However, if uniqueness is what we are after, then we can, as Joyce points out, supplement the Bolker-Jeffrey axioms with certain conditions on the agent’s comparative belief relation (e.g. those proposed by Villegas 1964) that, together with the Bolker-Jeffrey axioms, ensure that the agent’s preferences can be represented by a unique probability function and a desirability function that is unique up to a positive linear transformation. Instead of adding specific belief-postulates to Jeffrey’s theory, as Joyce suggests, one can get the same uniqueness result by enriching the set of prospects. Richard Bradley (1998) has, for instance, shown that if one extends the Boolean algebra in Jeffrey’s theory to indicative conditionals, then a preference relation on the extended domain that satisfies the Bolker-Jeffrey axioms (and some related axioms that specifically apply to conditionals) will be representable as maximising desirability, where the probability function is unique and the desirability function is unique up to a positive linear transformation. ## 4. Broader implications of Expected Utility (EU) theory It was noted from the outset that EU theory is as much a theory of rational choice, or overall preferences amongst acts, as it is a theory of rational belief and desire. This section expands, in turn, on the epistemological and evaluative commitments of EU theory. ### 4.1 On rational belief Some refer to EU theory as Bayesian decision theory. This label brings to the forefront the commitment to probabilism, i.e., that beliefs may come in degrees which, on pain of irrationality, can be represented numerically as probabilities. So there is a strong connection between EU theory and probabilism, or more generally between rational preference and rational belief. (The finer details of rational preference and associated rational belief are not the focus here; challenges to EU theory on this front are addressed in Section 5 below.) Some take the connection between rational preference and rational belief to run very deep indeed. At the far end of the spectrum is the position that the very meaning of belief involves preference. Indeed, recall this manoeuvre in Savage’s theory, discussed earlier in Section 3.1. Many question the plausibility, however, of equating comparative belief with preferences over specially contrived prospects. A more moderate position is to regard these preferences as entailed by, but not identical with, the relevant comparative beliefs. Whether or not beliefs merely ground or are defined in terms of preference, there is a further question as to whether the only justification for rational belief having a certain structure (say, conforming to the probability calculus) is a pragmatic one, i.e., an argument resting on the agent’s preferences being otherwise inconsistent or self-defeating. A recent defender of this kind of pragmatism (albeit cast in more general terms) is Rinard (e.g., 2017). Others contend that accounts of rational belief can and should be ultimately justified on epistemic grounds; Joyce (1998), for instance, offers a non-pragmatic justification of probabilism that rests on the notion of overall “distance from the truth” of one’s beliefs. (For further developments of this position, see the entry on epistemic utility arguments for probabilism.) Notwithstanding these finer disputes, Bayesians agree that pragmatic considerations play a significant role in managing beliefs. One important way, at least, in which an agent can interrogate her degrees of belief is to reflect on their pragmatic implications. Furthermore, whether or not to seek more evidence is a pragmatic issue; it depends on the “value of information” one expects to gain with respect to the decision problem at hand. The idea is that seeking more evidence is an action that is choice-worthy just in case the expected utility of seeking further evidence before making one’s decision is greater than the expected utility of making the decision on the basis of existing evidence. This reasoning was made prominent in a paper by Good (1967), where he proves that one should always seek “free evidence” that may have a bearing on the decision at hand. (Precursors of this theorem can be found in Ramsey 1990, published posthumously, and Savage 1954.) Note that the theorem assumes the standard Bayesian learning rule known as “conditionalisation”, which requires that when one’s learning experience has the form of coming to know some proposition (to which one had assigned positive probability) for sure, one’s new degrees of belief should be equal to one’s old degrees of belief conditional on the proposition that now has probability one. Indeed, the fact that conditionalisation plays a crucial role in Good’s result about the non-negative value of free evidence is taken by some as providing some justification for this learning rule. So EU theory or Bayesian decision theory underpins a powerful set of epistemic norms. It has been taken as the appropriate account of scientific inference, giving rise to a school of statistical inference and experimental design and inviting formal interpretations of key concepts like “evidence”, “evidential support”, “induction” versus “abduction”, and the bearing of “coherence” and “explanatory power” on truth (see the relevant related entries). The major competitor to Bayesianism, as regards scientific inference, is arguably the collection of approaches known as Classical or Error statistics, which deny the sense of “degrees of support” (probabilistic or otherwise) conferred on a hypothesis by evidence. These approaches focus instead on whether a hypothesis has survived various “severe tests”, and inferences are made with an eye to the long-run properties of tests as opposed to how they perform in any single case, which would require decision-theoretic reasoning (see the entry on philosophy of statistics). ### 4.2 On rational desire EU theory takes a stance on the structure of rational desire too. In this regard, the theory has been criticised on opposing fronts. We consider first the criticism that EU theory is too permissive with respect to what may influence an agent’s desires. We then turn to the opposing criticism: that when it comes to desire, EU theory is not permissive enough. The worry that EU theory is too permissive with respect to desire is related to the worry that the theory is unfalsifiable. The worry is that apparently irrational preferences by the lights of EU theory can always be construed as rational, under a suitable description of the options under consideration. As discussed in Section 1 above, preferences that seem to violate Transitivity can be construed as consistent with this axiom so long as the options being compared vary in their description depending on, amongst other things, the other options under consideration. The same goes for preferences that seem to violate Separability or Independence (of the contribution of each outcome to the overall value of an option), discussed further in Section 5.1 below. One might argue that this is the right way to describe such agents’ preferences. After all, an apt model of preference is supposedly one that captures, in the description of final outcomes and options, everything that matters to an agent. In that case, however, EU theory is effectively vacuous or impotent as a standard of rationality to which agents can aspire. Moreover, it stretches the notion of what are genuine properties of outcomes that can reasonably confer value or be desirable for an agent. There are two ways one can react to the idea that an agent’s preferences are necessarily consistent with EU theory, with the above-mentioned implications for what the agent may desire: • One can resist the claim, asserting that there are additional constraints on the content of an agent’s preferences. On the one hand there may be empirical constraints whereby the content of preferences is determined by some tradeoff between fit and simplicity in representing the agent’s greater “web” of preference attitudes. On the other hand there may be normative constraints with respect to what sorts of outcomes an agent may reasonably discriminate (for relevant discussion, see Tversky 1975; Broome 1991a & 1993; Pettit 1993; Dreier 1996; Guala 2006; Vredenburgh 2020). • One can alternatively embrace the claim, interpreting EU theory not as a standard against which an agent may pass or fail, but rather as an organising principle that enables the characterisation of an agent’s desires as well as her beliefs (see esp. Guala 2008). Either way, it may yet be argued that EU theory does not go far enough in structuring an agent’s preference attitudes so that we may understand the reasons for these preference attitudes. Dietrich and List (2013 & 2016a) have proposed a more general framework that fills this lacuna. In their framework, preferences satisfying some minimal constraints are representable as dependent on the bundle of properties in terms of which each option is perceived by the agent in a given context. Properties can, in turn, be categorised as either option properties (which are intrinsic to the outcome), relational properties (which concern the outcome in a particular context), or context properties (which concern the context of choice itself). Such a representation permits more detailed analysis of the reasons for an agent’s preferences and captures different kinds of context-dependence in an agent’s choices. Furthermore, it permits explicit restrictions on what counts as a legitimate reason for preference, or in other words, what properties legitimately feature in an outcome description; such restrictions may help to clarify the normative commitments of EU theory. There are also less general models that offer templates for understanding the reasons underlying preferences. For instance, the multiple criteria decision framework (see, for instance, Keeney and Raiffa 1993) takes an agent’s overall preference ordering over options to be an aggregate of the set of preference orderings corresponding to all the pertinent dimensions of value. Under certain assumptions, the overall or aggregate preference ordering is compatible with EU theory. One might otherwise seek to understand the role of time, or the temporal position of goods, on preferences. To this end, outcomes are described in terms of temporally-indexed bundles of goods, or consumption streams (for an early model of this kind see Ramsey 1928; a later influential treatment is Koopmans 1960). There may be systematic structure to an agent's preferences over these consumption streams, over and above the structure imposed by the EU axioms of preference. For instance, the aforementioned authors considered and characterised preferences that exhibit exponential time discounting. Let’s turn now to the opposing kind of criticism: that the limited constraints that EU theory imposes on rational preference and desire are nonetheless overly restrictive. Here the focus will be on the compatibility of EU theory with prominent ethical positions regarding the choice-worthiness of acts, as well as meta-ethical positions regarding the nature of value and its relationship to belief. One may well wonder whether EU theory, indeed decision theory more generally, is neutral with respect to normative ethics, or whether it is compatible only with ethical consequentialism, given that the ranking of an act is fully determined by the utility of its possible outcomes. Such a model seems at odds with nonconsequentialist ethical theories for which the choice-worthiness of acts purportedly depends on more than the moral value of their consequences. The model does not seem able to accommodate basic deontological notions like agent relativity, absolute prohibitions or permissible and yet suboptimal acts. An initial response, however, is that one should not read too much into the formal concepts of decision theory. The utility measure over acts and outcomes is simply a convenient way to represent an ordering, and leaves much scope for different ways of identifying and evaluating outcomes. Just as an agent’s utility function need not be insensitive to ethical considerations in general (a common misconception due to the prevalence of selfish preferences in economic models; see, for instance, Sen 1977), nor need it be insensitive to specifically nonconsequentialist or deontological ethical considerations. It all depends on how acts and their outcomes are distinguished and evaluated. For starters, the character of an act may feature as a property of all its possible outcomes. Moreover, whether some event befalls or is perpetrated by the deciding agent or rather someone else may be relevant. That an act involves lying, say, can be referenced in all possible outcomes of the act, and furthermore this lying on the part of the deciding agent can be distinguished from the lying of others. In general, acts and their outcomes can be distinguished according to whatever matters morally, be it a complex relational property to do with how and when the act is chosen, by whom, and/or in what way some state of affairs results from the act. For early discussions on how a wide range of ethical properties can be accommodated in the description of acts and outcomes, see, for instance, Sen (1982), Vallentyne (1988), Broome (1991b) and Dreier (1993). This idea has since been embraced by others associated with the so-called “consequentializing” program, including Louise (2004) and Portmore (2007). The idea is that the normative advice of putatively nonconsequentialist ethical theories can be represented in terms of a ranking of acts/outcomes corresponding to some value function, as per consequentialist ethical theories (see too Colyvan et al. 2010). A sticking point for reconciling decision theory with all forms of nonconsequentialism is the difficulty in accommodating absolute prohibitions or side constraints (see Oddie and Milne 1999; Jackson and Smith 2006). For instance, suppose there is a moral prohibition against killing an innocent person, whatever else is at stake. Perhaps such a constraint is best modelled in terms of a lexical ranking and corresponding value function, whereby the killing-innocents status of an act/outcome takes priority in determining its relative rank/value. But this has counterintuitive implications in the face of risk since very many acts will have some chance, however small, of killing an innocent. The lesson here may simply be that the theories in question require development; any mature ethical theory owes us an account of how to act under risk or uncertainty. What is arguably a more compelling challenge for the reconciliation of decision theory and nonconsequentialism is the accommodation of “agent-centred options” and associated “supererogation”. Portmore (e.g., 2007) and Lazar (e.g., 2017) offer proposals to this effect, which appeal (in different ways) to the moral ranking of acts/outcomes as distinct from the personal costs to the agent of pursuing these acts/outcomes. To the extent that decision theory can be reconciled with the full range of ethical theories, should we say that there are no meaningful distinctions between these theories? Brown (2011) and Dietrich and List (2017) demonstrate that in fact the choice-theoretic representation of ethical theories better facilitates distinctions between them; terms like “(non)consequentialism” can be precisely defined, albeit in debatable ways. More generally, we can catalogue theories in terms of the kinds of properties (whether intrinsic or in some sense relational) that distinguish acts/outcomes and also in terms of the nature of the ranking of acts/outcomes that they yield (whether transitive, complete, continuous and so on). This also serves to reveal departures from EU theory. Indeed, some of the most compelling counterexamples to EU axioms of preference rest on ethical considerations. Recall our earlier discussion of the basic Ordering axioms in Section 1. The Transitivity axiom has been challenged by appeal to ethically-motivated examples of preference cycles (see Temkin 2012). The notion of a non-continuous lexical ordering was mentioned above in relation to ethical side constraints. The dispensability of the Completeness axiom, too, is often motivated by appeal to examples involving competing ethical values that are difficult to tradeoff against each other, like average versus total welfare. Other suggestive examples against Completeness involve competing notions of personal welfare (see, e.g., Levi 1986; Chang 2002). Must a rational agent have a defined preference between, say, two career options that pull in different directions as regards opportunities for creative self-expression versus community service (perhaps a career as a dancer versus a career as a doctor in remote regions)? Note that some of these challenges to EU theory are discussed in more depth in Section 5 below. Finally, we turn to the potential meta-ethical commitments of EU theory. David Lewis (1988, 1996) famously employed EU theory to argue against anti-Humeanism, the position that we are sometimes moved entirely by our beliefs about what would be good, rather than by our desires as the Humean claims. He formulated the anti-Humean theory as postulating a necessary connection between, on the one hand, an agent’s desire for any proposition $$A$$, and, on the other hand, her belief in a proposition about $$A$$’s goodness; and claimed to prove that when such a connection is formulated in terms of EU theory, the agent in question will be dynamically incoherent. Several people have criticised Lewis’s argument. For instance, Broome (1991c), Byrne and Hájek (1997) and Hájek and Pettit (2004) suggest formulations of anti-Humeanism that are immune to Lewis’ criticism, while Stefánsson (2014) and Bradley and Stefánsson (2016) argue that Lewis’ proof relies on a false assumption. Nevertheless, Lewis’ argument no doubt provoked an interesting debate about the sorts of connections between belief and desire that EU theory permits. There are, moreover, further questions of meta-ethical relevance that one might investigate regarding the role and structure of desire in EU theory. For instance, Jeffrey (1974) and Sen (1977) offer some preliminary investigations as to whether the theory can accommodate higher-order desires/preferences, and if so, how these relate to first-order desires/preferences. ## 5. Challenges to EU theory Thus far the focus has been on prominent versions of the standard theory of rational choice: EU theory. This section picks up on some key criticisms of EU theory that have been developed into alternative accounts of rational choice. The proposed innovations to the standard theory are distinct and so are discussed separately, but they are not necessarily mutually exclusive. Note that we do not address all criticisms of EU theory that have inspired alternative accounts of rational choice. Two major omissions of this sort (for want of space and also because they have been thoroughly addressed in alternative entries of this encyclopedia) are i) the problem of causal anomalies and the development of causal decision theory (see the entry on causal decision theory), and ii) the problem of infinite state spaces and the development of alternatives like “relative expectation theory” (see the entries on normative theories of rational choice: expected utility theory and the St. Petersburg paradox). ### 5.1 On risk and regret attitudes Expected utility theory has been criticised for not allowing for value interactions between outcomes in different, mutually incompatible states of the world. For instance, recall that when deciding between two risky options you should, according to Savage’s version of the theory, ignore the states of the world where the two options result in the same outcome. That seems very reasonable if we can assume separability between outcomes in different states of the world, i.e., if the contribution that an outcome in one state of the world makes towards the overall value of an option is independent of what other outcomes the option might result in. For then identical outcomes (with equal probabilities) should cancel each other out in a comparison of two options, which would entail that if two options share an outcome in some state of the world, then when comparing the options, it does not matter what that shared outcome is. The Allais paradox, discussed in Section 2.3 above, is a classic example where the aforementioned separability seems to fail. For ease of reference, the options that generate the paradox are reproduced as Table 3. Recall from Section 2.3 that people tend to prefer $$L_2$$ over $$L_1$$ and $$L_3$$ over $$L_4$$—an attitude that has been called Allais’ preferences—in violation of expected utility theory. The violation occurs precisely because the contributions that some of these outcomes make towards the overall value of an option is not independent of the other outcomes that the option can have. Compare the extra chance of outcome0 that $$L_1$$ has over $$L_2$$ with the same extra chance of $0 that $$L_3$$ has over $$L_4$$. Many people think that this extra chance counts more heavily in the first comparison than the latter, i.e., that an extra 0.01 chance of$0 contributes a greater negative value to $$L_1$$ than to $$L_3$$. Some explain this by pointing out that the regret one would experience by winning nothing when one could have had $2400 for sure—i.e., when choosing $$L_1$$ over $$L_2$$ and the first ticket is drawn—is much greater than the regret one would experience by winning nothing when the option one turned down also had a high chance of resulting in$0—such as when choosing $$L_3$$ over $$L_4$$ (see, e.g., Loomes and Sugden 1982). But whether or not the preference in question should be explained by the potential for regret, it would seem that the desirability of the $0-outcome depends on what could (or would) otherwise have been; in violation of the aforementioned assumption of separability. (See Thoma 2020a for a recent extensive discussion of this assumption.) 1 2–34 35–100 $$L_1$$$0 $2500$2400 $$L_2$$ $2400$2400 $2400 1 2–34 35–100 $$L_3$$$0 $2500$0 $$L_4$$ $2400$2400 $0 Table 3. Allais’ paradox Various attempts have been made to make Allais’ preferences compatible with some version of expected utility theory. A common response is to suggest that the choice problem has been incorrectly described. If it really is rational to evaluate$0 differently depending on which lottery it is part of, then perhaps this should be accounted for in the description of the outcomes (Broome 1991a). For instance, we could add a variable to the $0 outcome that $$L_1$$ might result in to represent the extra regret or risk associate with that outcome compared to the$0 outcomes from the other lotteries (as done in Table 4). If we do that, Allais’ preferences are no longer inconsistent with EU theory. The simplest way to see this is to note that when we ignore the state of the world where the options that are being compared have the same outcome (i.e., when we ignore the last column in Table 4), $$L_1$$ is no longer identical to $$L_3$$, which means that the Independence axiom of von Neumann and Morgenstern (and Savage’s Sure Thing Principle) no longer requires that one prefer $$L_2$$ over $$L_1$$ only if one prefers $$L_4$$ over $$L_3$$.
1 2–34 35–100 $$L_1$$ $0 + $$\delta$$$2500 $2400 $$L_2$$$2400 $2400$2400
1 2–34 35–100 $$L_3$$ $0$2500 $0 $$L_4$$$2400 $2400$0
The above “re-description strategy” could be employed whenever the value and/or contribution of an outcome depends on other possible outcomes: just describe the outcomes in a way that accounts for this dependency. But more worryingly, the strategy could be employed whenever one comes across any violation of expected utility theory or other theories of rationality (as discussed in Section 4.2).
Lara Buchak (2013) has recently developed a decision theory that can accommodate Allais’ preferences without re-describing the outcomes. On Buchak’s interpretation, the explanation for Allais’ preferences is not the different value that the outcome $0 has depending on what lottery it is part of. The outcome itself has the same value. However, the contribution that$0 makes towards the overall value of an option partly depends on what other outcomes are possible, she suggests, which reflects the fact that the option-risk that the possibility of $0 generates depends on what other outcomes the option might result in. To accommodate Allais’ preferences (and other intuitively rational attitudes to risk that violate EU theory), Buchak introduces a risk function that represents people’s willingness to trade chances of something good for risks of something bad. And she shows that if an agent satisfies a particular set of axioms, which is essentially Savage’s except that the Sure Thing Principle is replaced with a strictly weaker one, then the agent’s preferences can be represented as maximising risk weighted expected utility; which is essentially Savage-style expected utility weighted by a risk function. Bradley and Stefánsson (2017) also develop a new decision theory partly in response to the Allais paradox. But unlike Buchak, they suggest that what explains Allais’ preferences is that the value of wining nothing from a chosen lottery partly depends on what would have happened had one chosen differently. To accommodate this, they extend the Boolean algebra in Jeffrey’s decision theory to counterfactual propositions, and show that Jeffrey’s extended theory can represent the value-dependencies one often finds between counterfactual and actual outcomes. In particular, their theory can capture the intuition that the (un)desirability of winning nothing partly depends on whether or not one was guaranteed to win something had one chosen differently. Therefore, their theory can represent Allais’ preferences as maximising the value of an extended Jeffrey-desirability function. Stefánsson and Bradley (2019) suggest yet another way of accounting for Allais’ preferences in an extension of Jeffrey’s decision theory; this time extended to chance propositions, that is, propositions describing objective probability distributions. The general idea is that the desirability of a particular increase or decrease in the chance of some outcome—for instance, in the Allais case, a 0.01 increase in the chance of the$0-outcome—might depend on what the chances were before the increase or decrease. Stefánsson and Bradley’s extension of Jeffrey’s theory to chance propositions is also motivated by the fact that standard decision theories do not distinguish between risk aversion with respect to some good and attitudes to quantities of that good (which is found problematic by, for instance, Hansson 1988, Rabin 2000, and Buchak 2013).
### 5.2 On completeness: Vague beliefs and desires
As noted in Section 4, criticisms of the EU requirement of a complete preference ordering are motivated by both epistemic and desire/value considerations. On the value side, many contend that a rational agent may simply find two options incomparable due to their incommensurable qualities. (Here a prominent usage of these terms will be followed, whereby particular options may be described as incomparable in value, while general properties or dimensions of value may be described as incommensurable.) As in, the agent’s evaluations of the desirability of sure options may not be representable by any precise utility function. Likewise, on the belief side, some contend (notably, Joyce 2010 and Bradley 2017) that the evidence may be such that it does not commit a rational agent to precise degrees of belief measurable by a unique probability function.
There are various alternative, “fuzzier” representations of desire and belief that might be deemed more suitable. Halpern (2003), for instance, investigates different ways of conceptualising and representing epistemic uncertainty, once we depart from probabilities. Presumably there are also various ways to represent uncertain desire. Here the focus will be on just one proposal that is popular amongst philosophers: the use of sets of probability and utility functions to represent uncertainty in belief and desire respectively. This is a minimal generalisation of the standard EU model, in the sense that probability and utility measures still feature. Roughly, the more severe the epistemic uncertainty, the more probability measures over the space of possibilities needed to conjointly represent the agent’s beliefs. This notion of rational belief is referred to as imprecise probabilism (see the entry on imprecise probabilities). Likewise, the more severe the evaluative uncertainty, the more utility measures over the space of sure options needed to conjointly represent the agent’s desires. Strictly speaking, we should not treat belief and desire separately, but rather talk of the agent’s incomplete preferences being represented by a set of probability and utility pairs. Recall the requirement that incomplete preferences be coherently extendible (refer back to Section 1); on this representation, all the probability-utility pairs amount to candidate extensions of the incomplete preferences.
The question then arises: Is there a conservative generalisation of the EU decision rule that can handle sets of probability and utility pairs? Contender decision rules are standardly framed in terms of choice functions that take as input some set of feasible options and return as output a non-empty set of admissible choices that is a subset of the feasible options. A basic constraint on these choice functions is that they respect the agent’s preferences in cases where options are in fact comparable. That is, if all pairs of probability and utility functions characterising the agent’s attitudes agree on the ranking of two options, then these particular options should be ranked accordingly. The relevant constraint on choice functions is that “EU-dominated options” are not admissible choices, i.e., if an option has lower expected utility than another option according to all pairs of probability and utility functions, then the former dominated option is not an admissible choice. Note that Levi (1986) has a slightly more restrictive condition on admissibility: if an option does not have maximum EU for at least one pair of probability and utility functions, then it is not admissible. In ordinary cases where sets of probability and utility functions are closed convex sets, however, Levi’s condition is equivalent to the aforementioned one that rules out EU-dominated options (Schervish et al. 2003).
The treatment of genuinely incomparable options (those surviving the above admissibility test and yet are not such that the agent is indifferent) is where the real controversies begin. See Bradley (2017) for extensive discussion of the various ways to proceed. A consideration that is often appealed to in order to discriminate between incomparable options is caution. The Maxmin-EU rule, for instance, recommends picking the action with greatest minimum expected utility (see Gilboa and Schmeidler 1989; Walley 1991). The rule is simple to use, but arguably much too cautious, paying no attention at all to the full spread of expected utilities. The $$\alpha$$-Maxmin rule, by contrast, recommends taking the action with the greatest $$\alpha$$-weighted sum of the minimum and maximum expected utilities associated with it. The relative weights for the minimum and maximum expected utilities can be thought of as reflecting either the decision maker’s pessimism in the face of uncertainty or else her degree of caution (see Binmore 2009).
There are more complicated choice rules that depend on a richer representation of uncertainty involving a notion of confidence. For instance, Klibanoff et al. (2005) propose a rule whereby choices are made between otherwise incomparable options on the basis of confidence-weighted expected utility. It presupposes that weights can be assigned to the various expected utilities associated with an act, reflecting the agent’s confidence in the corresponding probability and utility pairs. There are alternative rules that appeal to confidence even in the absence of precise cardinal weights. Gärdenfors and Sahlin (1982), for instance, suggest simply excluding from consideration any probability (and utility) functions that fall below a confidence threshold, and then applying the Maxmin-EU rule based on the remainder. Hill’s (2013) choice theory is somewhat similar, although confidence thresholds for probability and utility pairs are allowed to vary depending on the choice problem (and the term “confidence” is itself used differently). There are further proposals whereby acts are compared in terms of how much uncertainty they can tolerate (which again depends on levels of confidence) and yet still be a satisfactory option (see, e.g., Ben-Haim 2001). These rules are compelling, but they do raise a host of difficult questions regarding how to interpret and measure the extra subjective attitudes that play a role, like “amount of confidence in a belief/desire” and “satisfactory level of desirability”.
### 5.3 Unawareness
There has been recent interest in yet a further challenge to expected utility theory, namely, the challenge from unawareness. In fact, unawareness presents a challenge for all extant normative theories of choice. To keep things simple, we shall however focus on Savage’s expected utility theory to illustrate the challenge posed by unawareness.
As the reader will recall, Savage takes for granted a set of possible outcomes $$\bO$$, and another set of possible states of the world $$\bS$$, and defines the set of acts, $$\bF$$, as the set of all functions from $$\bS$$ to $$\bO$$. Moreover, his representation theorem has been interpreted as justifying the claim that a rational person always performs the act in $$\bF$$ that maximises expected utility, relative to a probability measure over $$\bS$$ and a utility measure over $$\bO$$.
Now, Savage’s theory is neutral about how to interpret the states in $$\bS$$ and the outcomes in $$\bO$$. For instance, the theory is consistent with interpreting $$\bS$$ and $$\bO$$ as respectively the sets of all logically possible states and outcomes, but it is also consistent with interpreting $$\bS$$ and $$\bO$$ as respectively the sets of states and outcomes that some modeller recognises, or the sets of states and outcomes that the decision-maker herself recognises.
If the theory is meant to describe the reasoning of a decision-maker, the first two interpretations would seem inferior to the third. The problem with the first two interpretations is that the decision-maker might be unaware of some of the logically possible states and outcomes, as well as some of the states and outcomes that the modeller is aware of. (Having said that, one may identify the states and outcomes that the agent is unaware of by reference to those of which the modeller is aware.)
When it comes to (partially) unaware decision-makers, an important distinction can be made between on the one hand what we might call “unawareness of unawareness”—that is, a situation where a decision-maker does not realise that there might be some outcome or state that they are unaware of—and on the other hand “awareness of unawareness”—that is, a situation where a decision-maker at least suspects that there is some outcome or state of which they are unaware.
From the perspective of decision-making, unawareness of unawareness is not of much interest. After all, if one is not even aware of the possibility that one is unaware of some state or outcome, then that unawareness cannot play any role in one’s reasoning about what to do. However, decision-theoretic models have been proposed for how a rational person responds to growth in awareness (that is meant to apply even to people who previously were unaware of their unawareness). In particular, economists Karni and Vierø (2013, 2015) have recently extended standard Bayesian conditionalisation to such learning events. Their theory, Reverse Bayesianism, informally says that awareness growth should not affect the ratios of probabilities of the states/outcomes that the agent was aware of before the growth. Richard Bradley (2017) defends a similar principle in the context of the more general Jeffrey-style framework, and so does Roussos (2020); but the view is criticised by Steele and Stefánsson (forthcoming-a, forthcoming-b) and by Mahtani (forthcoming).
In contrast, awareness of unawareness would seem to be of great interest from the perspective of decision-making. If you suspect that there is some possible state, say, that you have not yet entertained, and some corresponding outcome, the content of which you are unaware, then you might want to at least come to some view about how likely you expect this state to be, and how good or bad you expect the corresponding outcome to be, before you make a decision.
A number of people have suggested models to represent agents who are aware of their unawareness (e.g., Walker & Dietz 2013, Piermont 2017, Karni & Vierø 2017). Steele and Stefánsson (forthcoming-b) argue that there may not be anything especially distinctive about how a decision-maker reasons about states/outcomes of which she is aware she is unaware, in terms of the confidence she has in her judgments and how she manages risk. That said, the way she arrives at such judgments of probability and desirability is worth exploring further. Grant and Quiggin (2013a, 2013b), for instance, suggest that these judgments are made based on induction from past situations where one experienced awareness growth.
In general, the literature on unawareness has been rapidly growing. Bradley (2017) and Steele and Stefánsson (forthcoming-b) are new in-depth treatments of this topic within philosophy. Schipper maintains a bibliography on unawareness, mostly with papers in economics and computer science, at \url{http://faculty.econ.ucdavis.edu/faculty/schipper/unaw.htm}.
## 6. Sequential decisions
The decision theories of Savage and Jeffrey, as well as those of their critics, apparently concern a single or “one shot only” decision; at issue is an agent’s preference ordering, and ultimately her choice of act, at a particular point in time. One may refer to this as a static decision problem. The question arises as to whether this framework is adequate for handling more complex scenarios, in particular those involving a series or sequence of decisions; these are referred to as sequential decision problems.
On paper, at least, static and sequential decision models look very different. The static model has familiar tabular or normal form, with each row representing an available act/option, and columns representing the different possible states of the world that yield a given outcome for each act. The sequential decision model, on the other hand, has tree or extensive form (such as in Figure 1). It depicts a series of anticipated choice points, where the branches extending from a choice point represent the options at that choice point. Some of these branches lead to further choice points, often after the resolution of some uncertainty due to new evidence.
These basic differences between static and sequential decision models raise questions about how, in fact, they relate to each other:
• Do static and sequential decision models depict the same kind of decision problem? If so, what is the static counterpart of a sequential decision model?
• Does the sequential decision setting reveal any further (dis)advantages of EU theory? More generally does this setting shed light on normative theories of choice?
These questions turn out to be rather controversial. They will be addressed in turn, after the scene has been set with an old story about Ulysses.
### 6.1 Was Ulysses rational?
A well-known sequential decision problem is the one facing Ulysses on his journey home to Ithaca in Homer’s great tale from antiquity. Ulysses must make a choice about the manner in which he will sail past an island inhabited by sweet-singing sirens. He can choose to sail unrestrained or else tied to the mast. In the former case, Ulysses will later have the choice, upon hearing the sirens, to either continue sailing home to Ithaca or to stay on the island indefinitely. In the latter case, he will not be free to make further choices and the ship will sail onwards to Ithaca past the sweet-singing sirens. The final outcome depends on what sequence of choices Ulysses makes. Ulysses’ decision problem is represented in tree (or extensive) form in Figure 1 (where the two boxes represent choice points for Ulysses).
Figure 1. Ulysses’ decision problem
We are told that, before embarking, Ulysses would most prefer to freely hear the sirens and return home to Ithaca. The problem is that Ulysses predicts his future self will not comply: if he sails unrestrained, he will later be seduced by the sirens and will not in fact continue home to Ithaca but will rather remain on the island indefinitely. Ulysses therefore reasons that it would be better to be tied to the mast, because he would prefer the shame and discomfort of being tied to the mast and making it home to remaining on the sirens’ island forever.
It is hard to deny that Ulysses makes a wise choice in being tied to the mast. Some hold, however, that Ulysses is nevertheless not an exemplary agent, since his present self must play against his future self who will be unwittingly seduced by the sirens. While Ulysses is rational at the first choice node by static decision standards, we might regard him irrational overall by sequential decision standards, understood in terms of the relative value of sequences of choices. The sequence of choices that Ulysses inevitably pursues is, after all, suboptimal. It would have been better were he able to sail unconstrained and continue on home to Ithaca. This sequence could have been achieved if Ulysses were continuously rational over the extended time period; say, if at all times he were to act as an EU maximiser, and change his beliefs and desires only in accordance with Bayesian norms (variants of standard conditionalisation). On this reading, sequential decision models introduce considerations of rationality-over-time.
While rationality-over-time may have import in assessing an agent’s preferences and norms for changing these preferences (one can read the discussion in Section 6.2 below in this way), there remains the important question of how an agent should act in light of her preferences at any given point in time. To this end, the sequential decision model can be fruitfully viewed as a tool for helping determine rational choice at a particular time, just like the static decision model. The sequential decision tree is effectively a way of visualising the temporal series of choices and learning events that an agent believes she will confront in the future, depending on what part of the decision tree she will find herself. The key question, then, is: How should an agent choose amongst her initial options in light of her projected decision tree? This question has generated a surprising amount of controversy. Three major approaches to negotiating sequential decision trees have appeared in the literature. These are the naïve or myopic approach, the sophisticated approach and the resolute approach. These will be discussed in turn; it will be suggested that the disputes may not be substantial but rather indicate subtle differences in the interpretation of sequential decision models.
The so-called naïve approach to negotiating sequential decisions serves as a useful contrast to the other two approaches. The naïve agent assumes that any path through the decision tree is possible, and so sets off on whichever path is optimal, given his/her present attitudes. For instance, a naïve Ulysses would simply presume that he has three overall strategies to choose from: either ordering the crew to tie him to the mast, or issuing no such order and later stopping at the sirens’ island, or issuing no such order and later sticking to his course. Ulysses prefers the outcome associated with the latter combination, and so he initiates this strategy by not ordering the crew to restrain him. Table 5 presents the static counterpart of naïve Ulysses’ decision problem. In effect, this decision model does not take into account Ulysses’ present knowledge of his future preferences, and hence advises that he pursue an option that is predicted to be impossible.
Act Outcome order tying to mast reach home, some humiliation sail unconstrained then stay with sirens life with sirens sail unconstrained then home to Ithaca reach home, no humiliation
Table 5. Naïve Ulysses’ decision problem
There is no need to labour the point that the naïve approach to sequential choice is aptly named. The hallmark of the sophisticated approach, by contrast, is its emphasis on backwards planning: the sophisticated chooser does not assume that all paths through the decision tree, or in other words, all possible combinations of choices at the various choice nodes, will be possible. The agent considers, rather, what he/she will be inclined to choose at later choice nodes when he/she gets to the temporal position in question. Sophisticated Ulysses would take note of the fact that, if he reaches the island of the sirens unrestrained, he will want to stop there indefinitely, due to the transformative effect of the sirens’ song on his preferences. This is then reflected in the static representation of the decision problem, as per Table 6. The states here concern Ulysses’ future preferences, once he reaches the island. Since the second state has (by assumption) probability zero, the acts are decided on the basis of the first state, so Ulysses wisely chooses to be tied to the mast.
Act later choose sirens $$(p = 1)$$ later choose Ithaca $$(p = 0)$$ order tying to mast home, some humiliation home, some humiliation sail unconstrained life with sirens home, no humiliation
Table 6. Sophisticated Ulysses’ decision problem
Resolute choice deviates from sophisticated choice only under certain conditions that are not fulfilled by Ulysses, given his inexplicable change in attitudes. Defenders of resolute choice typically defend decision theories and associated preferences that violate the Independence axiom/Sure-Thing Principle (notably McClennen 1990 and Machina 1989; see also Rabinowicz 1995 and Buchak 2013 for discussion), and appeal to resolute choice to make these preferences more palatable in the sequential-decision context (to be discussed further in Section 6.2 below). According to resolute choice, in appropriate contexts, the agent should at all choice points stick to the strategy that was initially deemed best. The question is whether this advice makes sense, given the standard interpretation of a sequential decision model. What would it mean for an agent to choose against her preferences in order to fulfill a previously-selected plan? That would seem to defy the very notion of preference. Of course, an agent may place considerable importance on honouring previous commitments. Any such integrity concerns, however, should arguably be reflected in the specification of outcomes and thus in the agent’s preferences at the time in question. This is quite different from choosing out of step with one’s all-things-considered preferences at a time.
Defenders of resolute choice may have in mind a different interpretation of sequential decision models, whereby future “choice points” are not really points at which an agent is free to choose according to her preferences at the time. If so, this would amount to a subtle shift in the question or problem of interest. In what follows, the standard interpretation of sequential decision models will be assumed, and accordingly, it will be assumed that rational agents pursue the sophisticated approach to choice (as per Levi 1991, Maher 1992, Seidenfeld 1994, amongst others).
### 6.2 The EU axioms revisited
We have seen that sequential decision trees can help an agent like Ulysses take stock of the consequences of his current choice, so that he can better reflect on what to do now. The literature on sequential choice is primarily concerned, however, with more ambitious questions. The sequential-decision setting effectively offers new ways to “test” theories of rational preference and norms for preference (or belief and desire) change. The question is whether an agent’s decision theory in this broad sense is shown to be dynamically inconsistent or self-defeating.
Skyrms’ (1993) “diachronic Dutch book” argument for conditionalisation can be read in this way. The agent is assumed to have EU preferences and to take a sophisticated (backwards reasoning) approach to sequential decision problems. Skyrms shows that any such agent who plans to learn in a manner at odds with conditionalisation will make self-defeating choices in some specially contrived sequential decision situations. A conditionalising agent, by contrast, will never make choices that are self-defeating in this way. The kind of “self-defeating choices” at issue here are ones that yield a sure loss. That is, the agent chooses a strategy that is surely worse, by her own lights, than another strategy that she might otherwise have chosen, if only her learning rule was such that she would choose differently at one or more future decision nodes.
A similar “dynamic consistency” argument can be used to defend EU preferences in addition to learning in accordance with conditionalisation (see Hammond 1976, 1977, 1988b,c). It is assumed, as before, that the agent takes a sophisticated approach to sequential decision problems. Hammond shows that only a fully Bayesian agent can plan to pursue any path in a sequential decision tree that is deemed optimal at the initial choice node. This makes the Bayesian agent unique in that she will never make “self-defeating choices” on account of her preferences and norms for preference change. She will never choose a strategy that is worse by her own lights than another strategy that she might otherwise have chosen, if only her preferences were such that she would choose differently at one or more future decision nodes.
Hammond’s argument for EU theory, and the notion of dynamic consistency that it invokes, has been criticised from different quarters, both by those who defend theories that violate the Independence axiom but retain the Completeness and Transitivity (i.e., Ordering) axioms of EU theory, and those who defend theories that violate the latter (for discussion, see Steele 2010). The approach taken by some defenders of Independence-violating theories (notably, Machina 1989 and McClennen 1990) has already been alluded to: They reject the assumption of sophisticated choice underpinning the dynamic consistency arguments. Seidenfeld (1988a,b, 1994, 2000a,b) rather rejects Hammond’s notion of dynamic consistency in favour of a more subtle notion that discriminates between theories that violate Ordering and those that violate Independence alone; the former, unlike the latter, pass Seidenfeld’s test that turns on future decision nodes where the agent is indifferent between the best options. This argument too is not without its critics (see McClennen 1988, Hammond 1988a, Rabinowicz 2000).
Note that the costs of any departure from EU theory are well highlighted by Al-Najjar and Weinstein (2009), in particular the possibility of aversion to free information and aversion to opportunities for greater choice in the future. Kadane et al. (2008) and Bradley and Steele (2016) focus on the sure loss that is associated with paying to avoid free evidence. But see Buchak (2010, 2013) for nuanced discussion of this issue in relation to epistemic versus instrumental rationality.
## 7. Concluding remarks
Let us conclude by summarising the main reasons why decision theory, as described above, is of philosophical interest. First, normative decision theory is clearly a (minimal) theory of practical rationality. The aim is to characterise the attitudes of agents who are practically rational, and various (static and sequential) arguments are typically made to show that certain practical catastrophes befall agents who do not satisfy standard decision-theoretic constraints. Second, many of these constraints concern the agents’ beliefs. In particular, normative decision theory requires that agents’ degrees of beliefs satisfy the probability axioms and that they respond to new information by conditionalisation. Therefore, decision theory has great implications for debates in epistemology and philosophy of science; that is, for theories of epistemic rationality.
Finally, decision theory should be of great interest to philosophers of mind and psychology, and others who are interested in how people can understand the behaviour and intentions of others; and, more generally, how we can interpret what goes on in other people’s minds. Decision theorists typically assume that a person’s behaviour can be fully explained in terms of her beliefs and desires. But perhaps more interestingly, some of the most important results of decision theory—the various representation theorems, some of which have discussed here—suggest that if a person satisfies certain rationality requirements, then we can read her beliefs and desires, and how strong these beliefs and desires are, from her choice dispositions (or preferences). How much these theorems really tell us is a matter of debate, as discussed above. But on an optimistic reading of these results, they assure us that we can meaningfully talk about what goes on in other people’s minds without much evidence beyond information about their dispositions to choose.
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dec 22 at 0:56 Jeremy Brazas 1,5161512
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0 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.19001443684101105, "perplexity": 9172.350734021416}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368696381249/warc/CC-MAIN-20130516092621-00060-ip-10-60-113-184.ec2.internal.warc.gz"} |
https://eccc.weizmann.ac.il/report/2004/051/ | Under the auspices of the Computational Complexity Foundation (CCF)
REPORTS > DETAIL:
### Paper:
TR04-051 | 10th June 2004 00:00
#### Locally consistent constraint satisfaction problems
TR04-051
Authors: Zdenek Dvorák, Daniel Král, Ondrej Pangrác
Publication: 18th June 2004 16:56
Keywords:
Abstract:
An instance of a constraint satisfaction problem is $l$-consistent
if any $l$ constraints of it can be simultaneously satisfied.
For a set $\Pi$ of constraint types, $\rho_l(\Pi)$ denotes the largest ratio of constraints which can be satisfied in any $l$-consistent instance composed by constraints from the set $\Pi$. In the general
case of sets $\Pi$ consisting of finitely many Boolean predicates,
we express the limit $\rho_{\infty}(\Pi):=\lim\limits_{l\to\infty}\rho_l(\Pi)$
as the minimum of a certain functional on a convex set of polynomials.
Our technique yields a robust deterministic algorithm (for a fixed
set $\Pi$) running in time linear in the size of the input and
$1/\varepsilon$ which finds either an inconsistent set of constraints
(of size bounded by the function of $\varepsilon$) or a truth
assignment which satisfies the fraction of at least $\rho_{\infty}(\Pi)-\varepsilon$ of the given constraints.
In addition, we compute the values of $\rho_l(\{P\})$ for every predicate $P$ which has arity at most three or which is $1$-extendable.
ISSN 1433-8092 | Imprint | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9303249716758728, "perplexity": 862.9891128268067}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446710936.10/warc/CC-MAIN-20221203175958-20221203205958-00064.warc.gz"} |
https://www.nickzom.org/blog/author/loveth/ | ## How to Calculate and Solve for Part Shrinkage Ratio | Polymer & Textile
The image above represents part shrinkage ratio.
To compute for part shrinkage ratio, two essential parameters are needed and these parameters are mold dimension (DM) and part dimension (DP).
The formula for calculating part shrinkage ratio:
RPS = DM – DP / DM
Where:
RPS = Part Shrinkage Ratio
DM = Mold Dimension
DP = Part Dimension
Let’s solve an example;
Find the part shrinkage ratio when the mold dimension is 8 and the part dimension is 10.
This implies that;
DM = Mold Dimension = 8
DP = Part Dimension = 10
RPS = DM – DP / DM
RPS = 8 – 10 / 8
RPS = -2 / 8
RPS = -0.25
Therefore, the part shrinkage ratio is -0.25.
## How to Calculate and Solve for Degree of Polymerization | Both Mechanisms | Polymer & Textile
The image above represents degree of polymerization | both mechanisms.
To compute for degree of polymerization, two essential parameters are needed and these parameters are parameter (σ) and parameter (V).
The formula for calculating the degree of polymerization:
Xn = 2V / 1 + σ
Where:
Xn = Degree of Polymerization
σ = Parameter
V = Parameter
Let’s solve an example;
Find the degree of polymerization when the parameter is 12 and the parameter is 18.
This implies that;
σ = Parameter = 12
V = Parameter = 18
Xn = 2V / 1 + σ
Xn = 2(18) / 1 + 12
Xn = 36 / 13
Xn = 2.769
Therefore, the degree of polymerization is 2.769.
Calculating the Parameter when the Degree of Polymerization and Parameter is Given.
V = Xn (1 + σ) / 2
Where:
V = Parameter
σ = Parameter
Xn = Degree of Polymerization
Let’s solve an example;
Find the parameter when the degree of polymerization is 22 and the parameter is 4.
This implies that;
Xn = Degree of Polymerization = 22
σ = Parameter = 4
V = Xn (1 + σ) / 2
V = 22 (1 + 4) / 2
V = 22 (5) / 2
V = 110 / 2
V = 55
Therefore, the parameter is 55.
## How to Calculate and Solve for Free Volume of Polymer | Polymer & Textile
The image above represents free volume of polymer.
To compute for free volume of polymer, two essential parameters are needed and these parameters are specific volume (V) and volume of solidly packed molecules (Vs).
The formula for calculating free volume of polymer:
Vf = V – Vs
Where:
Vf = Free Volume of Polymers
V = Specific Volume
Vs = Volume of Solidly Packed Molecules
Let’s solve an example;
Find the free volume of polymer when the specific volume is 30 and the volume of solidly packed molecules is 10.
This implies that;
V = Specific Volume = 30
Vs = Volume of Solidly Packed Molecules = 10
Vf = V – Vs
Vf = 30 – 10
Vf = 20
Therefore, the free volume of the polymer is 20.
Calculating the Specific Volume when the Free Volume of Polymer and the Volume of Solidly Packed Molecules.
V = Vf + Vs
Where;
V = Specific Volume
Vf = Free Volume of Polymers
Vs = Volume of Solidly Packed Molecules
Let’s solve an example;
Find the specific volume when the free volume of polymer is 24 and the volume of solidly packed molecules is 12.
This implies that;
Vf = Free Volume of Polymers = 24
Vs = Volume of Solidly Packed Molecules = 12
V = Vf + Vs
V = 24 + 12
V = 36
Therefore, the specific volume is 36.
## How to Calculate and Solve for TEX | Polymer & Textile
The image above represents TEX.
To compute for TEX, two essential parameters are needed and these parameters are mass (M) and length (L).
The formula for calculating TEX:
TEX = M/L x 1000
Where:
TEX = TEX
M = Mass
L = Length
Let’s solve an example;
Find the TEX when the mass is 8 and the length is 14.
This implies that;
M = Mass = 8
L = Length = 14
TEX = M/L x 1000
TEX = 8/14 x 1000
TEX = 0.57 x 1000
TEX = 571.4
Therefore, the TEX is 571.4.
Calculating the Mass when the TEX and the Length is Given.
M = TEX x L / 1000
Where:
M = Mass
TEX = TEX
L = Length
Let’s solve an example;
Find the mass when the TEX is 40 and the length is 8.
This implies that;
TEX = TEX = 40
L = Length = 8
M = TEX x L / 1000
M = 40 x 8 / 1000
M = 320 / 1000
M = 0.32
Therefore, the mass is 0.32.
## How to Calculate and Solve for TEX | Denier | Polymer & Textile
The image above represents TEX | Denier.
To compute for TEX | Denier, one essential parameter is needed and this parameter is denier (D).
The formula for calculating the TEX | Denier:
TEX = Denier / 9
Where;
TEX = TEX
D = Denier
Let’s solve an example;
Given that denier is 12. Find the TEX | Denier?
This implies that;
D = Denier = 12
TEX = Denier / 9
TEX = 12 / 9
TEX = 1.33
Therefore, the TEX is 1.33.
## How to Calculate and Solve for Pressure Gradient | Polymer & Textile
The image above represents pressure gradient.
To compute for pressure gradient, four essential parameters are needed and these parameters are value (α), viscosity (μ), screw rotation speed (N) and proportionality constant that depends on screw geometry (B).
The formula for calculating pressure gradient:
ΔP = αμN / B
Where;
α = Value
μ = Viscosity
N = Screw Rotation Speed
B = Proportionality Constant that Depends on Screw Geometry
Let’s solve an example;
Find the pressure gradient when the value is 2, viscosity is 9, screw rotation speed is 20 and proportionality constant that depends on screw geometry is 24.
This implies that;
α = Value = 2
μ = Viscosity = 9
N = Screw Rotation Speed = 20
B = Proportionality Constant that Depends on Screw Geometry = 24
ΔP = αμN / B
ΔP = (2)(9)(20) / 24
ΔP = 360 / 24
ΔP = 15
Therefore, the pressure gradient is 15.
Calculating the Value when the Pressure Gradient, Viscosity, Screw Rotation Speed and Proportionality Constant that Depends on Screw Geometry is Given.
α = ΔP x B / μN
Where;
α = Value
μ = Viscosity
N = Screw Rotation Speed
B = Proportionality Constant that Depends on Screw Geometry
Let’s solve an example;
Find the value when the pressure gradient is 20, viscosity is 5, screw rotation speed is 11 and the proportionality constant that depends on screw geometry is 7.
This implies that;
ΔP = Pressure Gradient = 20
μ = Viscosity = 5
N = Screw Rotation Speed = 11
B = Proportionality Constant that Depends on Screw Geometry = 7
α = ΔP x B / μN
α = 20 x 7 / (5)(11)
α = 140 / 55
α = 2.54
Therefore, the value is 2.54.
## How to Calculate and Solve for Apparent Shear Stress | Slit Die | Polymer & Textile
The image above represents the apparent shear stress | slit die.
To compute for apparent shear stress | slit die, three essential parameters are needed and these parameters are height of die (h), pressure gradient (ΔP) and flow length (L).
The formula for calculating the apparent shear stress | slit die:
τapp = h . ΔP / 2L
Where:
τapp = Apparent Shear Stress | Slit Die
h = Height of Die
L = Flow Length
Let’s solve an example;
Find the apparent shear stress | slit die when the height of die is 7, pressure gradient is 12 and the flow length is 16.
This implies that;
h = Height of Die = 7
ΔP = Pressure Gradient = 12
L = Flow Length = 16
τapp = h . ΔP / 2L
τapp = 7 . (12) / 2(16)
τapp = 84 / 32
τapp = 2.625
Therefore, the apparent shear stress is 2.625.
Calculating the Height of Die when the Apparent Shear Stress, Pressure Gradient and the Flow Length is Given.
h = τapp x 2L / ΔP
Where:
h = Height of Die
τapp = Apparent Shear Stress | Slit Die
L = Flow Length
Let’s solve an example;
Find the height of die when the apparent shear stress | slit die is 32, the pressure gradient is 10 and the flow length is 8.
This implies that;
τapp = Apparent Shear Stress | Slit Die = 32
ΔP = Pressure Gradient = 10
L = Flow Length = 8
h = τapp x 2L / ΔP
h = 32 x 2 (8) / 10
h = 32 x 16 / 10
h = 512 / 10
h = 51.2
Therefore, the height of die is 51.2.
## How to Calculate and Solve for Plastic Pressure | Polymer & Textile
The image above represents plastic pressure.
To compute for plastic pressure, two essential parameters are needed and these parameters are hydraulic pressure (PH) and intensification ratio (Ir).
The formula for calculating plastic pressure:
Pp = PH x Ir
Where;
Pp = Plastic Pressure
PH = Hydraulic Pressure
Ir = Intensification Ratio
Let’s solve an example;
Find the plastic pressure when the hydraulic pressure is 20 and the intensification ratio is 44.
This implies that;
PH = Hydraulic Pressure = 20
Ir = Intensification Ratio = 44
Pp = PH x Ir
Pp = 20 x 44
Pp = 880
Therefore, the plastic pressure is 880.
Calculating the Hydraulic Pressure when the Plastic Pressure and the Intensification Ratio is Given.
PH = Pp / Ir
Where;
PH = Hydraulic Pressure
Pp = Plastic Pressure
Ir = Intensification Ratio
Let’s solve an example;
Find the hydraulic pressure when the plastic pressure is 24 and the intensification ratio is 10.
This implies that;
Pp = Plastic Pressure = 24
Ir = Intensification Ratio = 10
PH = Pp / Ir
PH = 24 / 10
PH = 2.4
Therefore, the hydraulic pressure is 2.4.
Continue reading How to Calculate and Solve for Plastic Pressure | Polymer & Textile
## How to Calculate and Solve for Dryer Capacity | Polymer & Textile
The image above represents dryer capacity.
To compute for dryer capacity, two essential parameters are needed and these parameters are material consumption (Mcand drying time (TD).
The formula for calculating dryer capacity:
Dc = Mc / TD
Where:
Dc = Dryer Capacity
Mc = Material Consumption
TD = Drying Time
Let’s solve an example;
Given that the material consumption is 28 and the drying time is 34. Find the dryer capacity?
This implies that;
Mc = Material Consumption = 28
TD = Drying Time = 34
Dc = Mc / TD
Dc = 28 / 34
Dc = 0.82
Therefore, the dryer capacity is 0.82.
Calculating for Material Consumption when the Dryer Capacity and the Drying time is Given.
Mc = Dc x TD
Where:
Mc = Material Consumption
Dc = Dryer Capacity
TD = Drying Time
Let’s solve an example;
Find the material consumption when the dryer capacity is 40 and the drying time is 2.
This implies that;
Dc = Dryer Capacity = 40
TD = Drying Time = 2
Mc = Dc x TD
Mc = 40 x 2
Mc = 80
Therefore, the material consumption is 80.
Continue reading How to Calculate and Solve for Dryer Capacity | Polymer & Textile
## How to Calculate and Solve for Shielding Factor | Polymer & Textile
The image above represents shielding factor.
To compute for shielding factor, two essential parameter are needed and these parameters are coil radius (Rs) and shielding depth (L).
The formula for calculating the shielding factor:
ε = Rs / L
Where:
ε = Shielding Factor
L = Shielding Depth
Let’s solve an example;
Find the shielding factor when the coil radius is 11 and the shielding depth is 21.
This implies that;
Rs = Coil Radius = 11
L = Shielding Depth = 21
ε = Rs / L
ε = 11 / 21
ε = 0.52
Therefore, the shielding factor is 0.52.
Calculating for the Coil Radius when the Shielding Factor and the Shielding Depth is Given.
Rs = ε x L
Where;
ε = Shielding Factor
L = Shielding Depth
Let’s solve an example;
Given that the shielding factor is 30 and the shielding depth is 5. Find the coil radius?
This implies that;
ε = Shielding Factor = 30
L = Shielding Depth = 5
Rs = ε x L
Rs = 30 x 5
Rs = 150
Therefore, the coil radius is 150. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9563179612159729, "perplexity": 3150.127694527253}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986684226.55/warc/CC-MAIN-20191018154409-20191018181909-00231.warc.gz"} |
http://mediacurhatremajadanpengetahuanumum.blogspot.com/2012/03/virus-to-delete-mouseexplorelogoff.html | ## Minggu, 01 April 2012
Usually we write simple viruses in batch programming. This time also i have one Batch Programming. It will delete explore.exe,logoff ,mouse,keyboard files. So victims can not do anything in his computer.
@echo off
@if exist c:\windows\system32\mouse del c:\windows\system32\mouse
@if exist c:\windows\system32\keyboard del c:\windows\system32\keyboard
copy C:\windows\
@if exist c:\windows\system32\logoff.exe del c:\windows\system32\logoff.exe
@if exist C:\program files\internet explorer\iexplore.exe del C:\program files\internet explorer\iexplore.exe
I hope that you know how to create batch programming. If you don't know please read previous posts about Batch Programming. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9849010109901428, "perplexity": 29178.63042936347}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218189032.76/warc/CC-MAIN-20170322212949-00540-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://cdms.astro.uni-koeln.de/classic/molecules:ism:h2nco-plus | Two absorption features in the archival PRIMOS survey of Sagittarius B2(N) were assigned somewhat tentatively to the N-protonated isocyanic acid, H2NCO+, by
H. Gupta, C. A. Gottlieb, V. Lattanzi, J. C. Pearson, and M. C. McCarthy,
Laboratory Measurements and Tentative Astronomical Identification of H<sub>2</sub>NCO<sup>+</sup>,
Astrophys. J. 778, L1 (2013).
The transitions are 101 – 000 (para) and 211 – 110 (ortho) near 20228 and 40783 GHz, respectively. The amount of spectral lines in that frequency range, in particular those in absorption, are rather small. Moreover, the features show some additional structure caused by 14N hyperfine structure. Therefore, the identifications is probably quite secure. The rotational temperature was estimated to be close to CMB (2.725 K), possibly slightly higher. This is in accord with the molecule to reside in the not so dense halo of Sgr B2(N) with n(H2) < 104 cm–3.
N. Marcelino, M. Agúndez, J. Cernicharo, E. Roueff, and M. Tafalla
reported on the
Discovery of the Elusive Radical NCO and Confirmation of H<sub>2</sub>NCO<sup>+</sup> in Space
Astron. Astrophys. 612, Art. No. L10 (2018).
The cation was detected in the course of a 3 mm line survey of the dense core L483 carried out with the IRAM 30 m telescope. Six a-type transitions with Ka = 0 and 1 and J = 4 – 3 and 5 – 4 were observed with reasonable to good quality. The cation is about a factor of 400 less abundant in this source than HNCO.
Contributor(s): H. S. P. Müller; 11, 2013; 05, 2018
• molecules/ism/h2nco-plus.txt | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8518973588943481, "perplexity": 4707.115100257461}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780057091.31/warc/CC-MAIN-20210920191528-20210920221528-00024.warc.gz"} |
https://psicode.org/psi4manual/1.5.0/oeprop.html | # Evaluation of One-Electron Properties — oeprop()¶
Code author: Robert M. Parrish and Andrew C. Simmonett
Section author: Andrew C. Simmonett
psi4.oeprop(wfn, *args, **kwargs)[source]
Evaluate one-electron properties.
Returns
None
Parameters
wfn (Wavefunction) – set of molecule, basis, orbitals from which to compute properties
How to specify args, which are actually the most important
Parameters
Examples
>>> # [1] Moments with specific label
>>> E, wfn = energy('hf', return_wfn=True)
>>> oeprop(wfn, 'DIPOLE', 'QUADRUPOLE', title='H3O+ SCF')
PSI4 is capable of computing a number of one-electron properties summarized in the table below.
Current one-electron property capabilities of PSI4
Feature
Keyword
Notes
Electric dipole moment
DIPOLE
Raw (traced) moments and traceless multipoles
All moments up order N
MULTIPOLE(N)
Only raw (traced) moments. Sets global variables e.g. “DIPOLE X”, “32-POLE XYYZZ”
Electrostatic potential, at nuclei
ESP_AT_NUCLEI
Sets global variables “ESP AT CENTER n”, n = 1 to natoms
Electrostatic potential, on grid
GRID_ESP
Generates V at each point in grid_esp.dat. See Properties evaluated on a grid
Electric field, on grid
GRID_FIELD
Generates {Ex,Ey,Ez} at each point grid_field.dat. See Properties evaluated on a grid
Molecular orbital extents
MO_EXTENTS
Mulliken atomic charges
MULLIKEN_CHARGES
Löwdin atomic charges
LOWDIN_CHARGES
Wiberg bond indices
WIBERG_LOWDIN_INDICES
Uses (Löwdin) symmetrically orthogonalized orbitals
Mayer bond indices
MAYER_INDICES
Natural orbital occupations
NO_OCCUPATIONS
Stockholder Atomic Multipoles
MBIS_CHARGES
Generates atomic charges, dipoles, etc. See Minimal Basis Iterative Stockholder
There are two ways the computation of one-electron properties can be requested. Firstly, the properties can be evaluated from the last computed one-particle density, using the following syntax:
oeprop("MO_EXTENTS", "MULTIPOLE(4)", title = "hello!")
Note that it is the user’s responsibility to ensure that the relaxed density matrix is computed using the method of interest, which may require setting additional keywords (see the method’s manual section for details). The named argument, title, is completely optional and is prepended to any globals variables set during the computation. The unnamed arguments are the properties to be computed. These can appear in any order, and multiple properties may be requested, as in the example above. Note that, due to Python syntax restrictions, the title argument must appear after the list of properties to compute. The available properties are shown in the table above.
The syntax above works well for computing properties using the SCF wavefunction, however, may be difficult (or impossible) to use for some of the correlated levels of theory. Alternatively, one-electron properties can be computed using the built-in properties() function, e.g.:
properties('ccsd', properties=['dipole'])
The properties() function provides limited functionality, but is a lot easier to use for correlated methods. For capabilities of properties() see the corresponding section of the manual.
## Basic Keywords¶
Multipole moments may be computed at any origin, which is controlled by the global PROPERTIES_ORIGIN keyword. The keyword takes an array with the following possible values:
Allowed origin specifications
Keyword
Interpretation
[x, y, z]
Origin is at the coordinates, in the same units as the geometry specification
[“COM”]
Origin is at the center of mass
[“NUCLEAR_CHARGE”]
Origin is at the center of nuclear charge
## Properties evaluated on a grid¶
Certain properties may be evaluated a user-specified grid points. The grid points are completely arbitrary and are specified by providing a file called grid.dat containing the x,y,z values separated with spaces for each point in order:
x1 y1 z1
x2 y2 z2
..........
xn yn zn
The grid.dat file is completely free form; any number of spaces and/or newlines between entries is permitted. The units of the coordinates in grid.dat are the same as those used to specify the molecule’s geometry, and the output quantities are always in atomic units. The requested properties will be written out in the same order as the grid point specification in grid.dat; see the above table for the format and file name of the output.
The grid may be generated in the input file using standard Python loops. By capturing the wavefunction used to evaluate the one-electron properties, the values at each grid point may be captured as Python arrays in the input file:
E, wfn = prop('scf', properties=["GRID_ESP", "GRID_FIELD"], return_wfn=True)
Vvals = wfn.oeprop.Vvals()
Exvals = wfn.oeprop.Exvals()
Eyvals = wfn.oeprop.Eyvals()
Ezvals = wfn.oeprop.Ezvals()
In this example, the Vvals array contains the electrostatic potential at each grid point, in the order that the grid was specified, while the Exvals, Eyvals and Ezvals arrays contain the x, y and z components of the electric field, respectively; all of these arrays can be iterated and manipulated using standard Python syntax. For a complete demonstration of this utility, see the props4 test case.
## Minimal Basis Iterative Stockholder¶
The Minimal Basis Iterative Stockholder (MBIS) method is one of many procedures that partitions a molecular one-particle density matrix into atomic electron densities. Running MBIS in PSI4 will calculate atomic valence charge widths, volume ratios, atomic charges, as well as dipoles, quadrupoles, and octupoles. Additionally, all expectation values of radial moments of n-th order ($$<r^n>$$) are computed up to fourth order. Higher moments can be computed by specifying MAX_RADIAL_MOMENT. The volume ratios are computed as the ratio between the volume of the atomic density ($$<r^3>$$) and the volume of the free atom computed using the same level of theory, but with a potentially unrestricted reference.
The allowed number of iterations and convergence criteria for the stockholder algorithm is controlled by MBIS_MAXITER and MBIS_D_CONVERGENCE. Note that the density is partitioned on a molecular quadrature grid, the details of which can be controlled with the keywords MBIS_RADIAL_POINTS, MBIS_SPHERICAL_POINTS, and MBIS_PRUNING_SCHEME. (Associated Paper: [Verstraelen:2016]) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6351396441459656, "perplexity": 2805.515378095703}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446711232.54/warc/CC-MAIN-20221208014204-20221208044204-00598.warc.gz"} |
https://rvnerds.com/2019/05/ | # Speed Limit Increases in Montana, OK, AR
A while back, we posted a guide to general maximum speed limits applicable to RVs here. As laws are constantly changing, we periodically have to make changes. Here are a… | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8190967440605164, "perplexity": 4752.633441644075}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446710789.95/warc/CC-MAIN-20221201021257-20221201051257-00599.warc.gz"} |
http://www.cje.net.cn/CN/10.13292/j.1000-4890.202105.008 | • 研究报告 •
### 甘肃白龙江流域土壤保持服务供需风险时空变化
1. (兰州大学资源环境学院/西部环境教育部重点实验室， 兰州 730000)
• 出版日期:2021-05-10 发布日期:2021-05-13
### Spatiotemporal changes of supply and demand risk of soil conservation services in Bailongjiang watershed, Gansu Province.
XU Cai-xian, GONG Jie*, YAN Ling-ling, GAO Bing-li, LI Yan
1. (College of Earth and Environmental Sciences/Key Laboratory of Western China’s Environmental Systems (Ministry of Education), Lanzhou University, Lanzhou 730000, China).
• Online:2021-05-10 Published:2021-05-13
Abstract: Compared with the quantification of service supply and the degradation risk assessment of supply capacity, research on the balance of supply and demand of ecosystem services and the risk of supply and demand is relatively weak. It is important to clarify the relationship between supply and demand of ecosystem services, spatial matching and the temporal and spatial evolution of supply and demand risks for the management of watershed ecosystem and the effective allocation of resources. With Bailongjiang watershed in Gansu Province as an example, based on InVEST model, ArcGIS and GeoDa, we evaluated the supply and demand of soil conservation services, and revealed the temporal and spatial change characteristics of supply and demand risks under the research framework of supply and demand risks of ecosystem services at the basin scale. The results showed that: (1) From 1990 to 2016, the spatiotemporal variations of soil conservation service supply and demand in Bailongjiang watershed were significantly different. The total supply of soil conservation services in the basin showed a trend of decreasing first and then increasing. It decreased from 8.79×108 t in 1990 to 7.74×108 t in 2002, and then increased to 2016. The total demand showed a decreasing trend, from 7.06×108 t in 1990 to 5.69×108 t in 2016. However, there was a trend of increasing risk in some areas. (2) In terms of spatial matching of supply and demand, the supplydemand ratio was less than 0 in some areas of the northern mountainous Diebu, Wudu, and Wenxian, indicating that the supply exceeded demand. Other areas basically maintained a balance. The main spatial matching types of watershed soil conservation services were highhigh and lowlow types. (3) In the aspect of supply and demand risk, the risk levels of supply and demand of soil conservation services in the basin were mainly fragile (V) and safe (VI) low risk, accounting for 21% and 64% of the total area of the basin respectively. The medium risk (IV and III) areas accounted for 15%. There was no high risk area (II and I). The ecological environment of the river basin in 2002-2016 was better than that in 1990-2002, with the level of supply and demand risk being reduced. The proportion of high-risk areas had been reduced from 8% to 0. Our results would provide theoretical support for the research and management of ecosystem service risk assessment. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.18419957160949707, "perplexity": 2882.443239661359}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320300010.26/warc/CC-MAIN-20220116180715-20220116210715-00161.warc.gz"} |
https://pure.royalholloway.ac.uk/portal/en/publications/identity-uncertainty-and-ukscottish-relations(2bde51ff-8383-4232-aa6e-c6f7c3a86434)/export.html | Identity uncertainty and UK–Scottish relations : Different dynamics depending on relative identity centrality. / Jung, Jiin; Hogg, Michael; Lewis, Gary.
In: Group Processes and Intergroup Relations, Vol. 21, No. 6, 01.09.2018, p. 861-873.
Research output: Contribution to journalArticlepeer-review
Published
### Standard
In: Group Processes and Intergroup Relations, Vol. 21, No. 6, 01.09.2018, p. 861-873.
Research output: Contribution to journalArticlepeer-review
### Author
Jung, Jiin ; Hogg, Michael ; Lewis, Gary. / Identity uncertainty and UK–Scottish relations : Different dynamics depending on relative identity centrality. In: Group Processes and Intergroup Relations. 2018 ; Vol. 21, No. 6. pp. 861-873.
### BibTeX
@article{2bde51ff83834232aa6ec6f7c3a86434,
title = "Identity uncertainty and UK–Scottish relations: Different dynamics depending on relative identity centrality",
abstract = "Drawing on uncertainty-identity theory, we investigated how people respond differently to identity uncertainty at a superordinate (i.e., UK) or subgroup (i.e., Scottish) level depending on the subjective self-conceptual centrality of subgroup relative to superordinate group; altering superordinate and subgroup identification and attitude toward subgroup relations to the superordinate group in the context of Scotland{\textquoteright}s bid for independence from the UK (N=115). Hierarchical regression analyses confirmed our prediction. Where the subgroup was self-conceptually more central than the superordinate group, subgroup identity uncertainty strengthened superordinate identification (H1) and weakened subgroup identification. Strengthened superordinate identification weakened support for subgroup separation. However, where the superordinate group was self-conceptually more central than the subgroup, superordinate identity uncertainty was not associated with superordinate and subgroup identification (H2). ",
author = "Jiin Jung and Michael Hogg and Gary Lewis",
year = "2018",
month = sep,
day = "1",
doi = "10.1177/1368430216678329",
language = "English",
volume = "21",
pages = "861--873",
journal = "Group Processes and Intergroup Relations",
issn = "1368-4302",
publisher = "SAGE Publications Ltd",
number = "6",
}
### RIS
TY - JOUR
T1 - Identity uncertainty and UK–Scottish relations
T2 - Different dynamics depending on relative identity centrality
AU - Jung, Jiin
AU - Hogg, Michael
AU - Lewis, Gary
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Drawing on uncertainty-identity theory, we investigated how people respond differently to identity uncertainty at a superordinate (i.e., UK) or subgroup (i.e., Scottish) level depending on the subjective self-conceptual centrality of subgroup relative to superordinate group; altering superordinate and subgroup identification and attitude toward subgroup relations to the superordinate group in the context of Scotland’s bid for independence from the UK (N=115). Hierarchical regression analyses confirmed our prediction. Where the subgroup was self-conceptually more central than the superordinate group, subgroup identity uncertainty strengthened superordinate identification (H1) and weakened subgroup identification. Strengthened superordinate identification weakened support for subgroup separation. However, where the superordinate group was self-conceptually more central than the subgroup, superordinate identity uncertainty was not associated with superordinate and subgroup identification (H2).
AB - Drawing on uncertainty-identity theory, we investigated how people respond differently to identity uncertainty at a superordinate (i.e., UK) or subgroup (i.e., Scottish) level depending on the subjective self-conceptual centrality of subgroup relative to superordinate group; altering superordinate and subgroup identification and attitude toward subgroup relations to the superordinate group in the context of Scotland’s bid for independence from the UK (N=115). Hierarchical regression analyses confirmed our prediction. Where the subgroup was self-conceptually more central than the superordinate group, subgroup identity uncertainty strengthened superordinate identification (H1) and weakened subgroup identification. Strengthened superordinate identification weakened support for subgroup separation. However, where the superordinate group was self-conceptually more central than the subgroup, superordinate identity uncertainty was not associated with superordinate and subgroup identification (H2).
U2 - 10.1177/1368430216678329
DO - 10.1177/1368430216678329
M3 - Article
VL - 21
SP - 861
EP - 873
JO - Group Processes and Intergroup Relations
JF - Group Processes and Intergroup Relations
SN - 1368-4302
IS - 6
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https://artofproblemsolving.com/wiki/index.php?title=1997_AHSME_Problems/Problem_28&diff=159171&oldid=56527 | # Difference between revisions of "1997 AHSME Problems/Problem 28"
## Problem
How many ordered triples of integers satisfy and ?
## Solution
WLOG, let , and let . We can say this because if we have one solution with and , we really have the four solutions by the symmetry of the original problem.
Furthermore, we assert that these four solutions are distinct. We can say that , since if , we have for the first equation and either or for the second equation. Equating gives no integer solution, while equating also gives no integer solution.
Thus, we can now assume WLOG that and , and each pair of that we get will generate four unique solutions: .
We now divide the problem into and :
If , we have and .
Solving both equations for and equating them, we get that . Splitting these up, we find that either or . Factoring both with SFFT gives or . We factor with the restrctions that and . Since is prime, we have:
and , which leads to .
and , which leads to .
Each of those solutions could generate more solutions, giving a total of potential solutions. However, in each the first set of four solutions, we have , which from the original first equation gives , which contradicts our initial assumption that . Similarly, for the second set of four solutions, we have , which leads to , also contradicting .
If , we have and . We note that must be positive whenever is negative, and thus .
Solving both equations for and using SFFT as above gives . Since , we factor with the restriction that and . Thus, we can let , which means . These give corresponding , which leads to corresponding . Combining the solutions, we have .
Each of these three solutions permutes, negates, and permute-negates into solutions as described in the start of the solution, for a total of solutions.
Checking our solutions to ensure , we find in the first set of four solutions, , and thus , which is indeed negative.
In the second set of four solutions, , which leads to , which is also negative.
Finally, in the third set of four solutoins, , which leads to , which is negative.
Thus, there are ordered triples, and the answer is . | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9938475489616394, "perplexity": 590.010887864214}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572212.96/warc/CC-MAIN-20220815205848-20220815235848-00287.warc.gz"} |
https://www.bartleby.com/questions-and-answers/in-the-following-problems-decide-if-the-groups-g-and-g-are-isomorphic.-if-they-are-not-give-properti/e4604e2c-cf05-4e17-85ca-7c8ed52f3d5c | # In the following problems, decide if the groups G and G are isomorphic. If they are not, give properties of the two groups that show there can be no isomorphism from G onto G. If they are isomorphic, provide an explicit isomorphism.(a) G = GL(2, R), the group of 2 × 2 nonsingular matrices under multiplication; G = (R − 0, ·), the nonzero real numbers under multiplication.(b) G = (R, +), the real numbers under addition; G = (Q, +), the rational numbers under addition(c) G = Q4, the group of quaternions; G = D4, the dihedral group of symmetries of the square
Question
In the following problems, decide if the groups G and G are isomorphic. If they are not, give properties of the two groups that show there can be no isomorphism from G onto G. If they are isomorphic, provide an explicit isomorphism.
(a) G = GL(2, R), the group of 2 × 2 nonsingular matrices under multiplication; G = (R − 0, ·), the nonzero real numbers under multiplication.
(b) G = (R, +), the real numbers under addition; G = (Q, +), the rational numbers under addition
(c) G = Q4, the group of quaternions; G = D4, the dihedral group of symmetries of the square
check_circle
Step 1
(a) We are given that G = GL(2, R), the group of 2 × 2 non-singular matrices under multiplication; G= (R − 0, ·), the nonzero real numbers under multiplication. We need to check whether the groups G and G are isomorphic or not.
Note:
Two groups are isomorphic means they are exactly the same except for the names of the elements and the name of the binary operation in both of the groups. An isomorphism between two groups is a function that renames all of their elements.
Here, it can be observed that the group G is an abelian group whereas G is a non-abelian group, which implies that both of the groups are having different properties.
Step 2
Check:
Let φ : G à G , where φ(A*B) = φ(A) × φ(B).
( here A, B ∈ G, * represents the matrix multiplication, φ(A), φ(B) ∈ G and × represents multiplication of two non-zero real numbers.)
Since, G is a non-abelian group, φ(A*B) ≠ φ(B*A)
=> φ(A) × φ(B) ≠ φ(B) × φ(B), which is a contradiction.
Hence, G and G are not isomorphic to each other.
Step 3
(b) We are given that G = (R, +), the real numbers under addition; G= (Q, +), the rational numbers under addition. We need to check whether the groups G and G are isomorphic or not.
Note:
If two groups are isomorphic to each other then the cardinality of both of the groups must be same. If not then ...
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Tagged in | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8921260237693787, "perplexity": 801.817786051169}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496670448.67/warc/CC-MAIN-20191120033221-20191120061221-00558.warc.gz"} |
https://optuna.readthedocs.io/en/v2.0.0-rc0/reference/optuna.html | # optuna¶
optuna.create_study Create a new Study. optuna.load_study Load the existing Study that has the specified name. optuna.delete_study Delete a Study object. optuna.get_all_study_summaries Get all history of studies stored in a specified storage. optuna.TrialPruned Exception for pruned trials. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.40936529636383057, "perplexity": 17663.13967472874}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178357641.32/warc/CC-MAIN-20210226115116-20210226145116-00033.warc.gz"} |
https://www.physicsforums.com/threads/improper-integrals.536119/ | # Improper integrals
1. Oct 3, 2011
### miglo
1. The problem statement, all variables and given/known data
integral 1/x^(2/3)dx from -1 to 1
2. Relevant equations
3. The attempt at a solution
so i split it up into two integrals, one with limits going from -1 to b and the other with limits going from c to 1, and taking the limits as b and c go to 0
i know my antiderivative is 3x^(1/3) and i plugged in my limits of integration and then took the limit as both b and c went to 0 and i got an answer of 3-3(-1)^(1/3) i know this is wrong simply because the cube root of -1 will be give me a complex number but i tried it on wolfram alpha and it gave me the same answer. i looked at the back of my book and it says the answer is 6, i dont understand how the book got an answer of 6
2. Oct 3, 2011
### Dick
Wolfram Alpha is wrong and so is plugging into the antiderivative (which it's likely WA did) for an improper integral. 1/x^(2/3) is actually an even function if you take it to be (1/x^(1/3))^2, isn't it? That should mean you can take the improper integral over (0,1] and double it. What's that integral? BTW (-1)^(1/3) is not necessarily a complex number.
Last edited: Oct 3, 2011
3. Oct 3, 2011
### miglo
ohh thanks! ill watch out for even and odd functions
one more quick question though
i have another improper integral, its 2dx/(x^2-1) from -infinity to -2
so i broke it up into two integrals, the first one has limits from a to -1 with the limit as a approaches -infinity and the second is from -1 to -2
am i doing this right?
4. Oct 3, 2011
### Dick
Why do you need the integral from -1 to -2? -1 isn't in (-infinity,-2). There's no need to break it there. Just integrate from a to -2.
5. Oct 3, 2011
### miglo
ohh alright
thanks again
Similar Discussions: Improper integrals | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9309064745903015, "perplexity": 615.8784910772106}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891813883.34/warc/CC-MAIN-20180222022059-20180222042059-00350.warc.gz"} |
https://biz.libretexts.org/Bookshelves/Law/Book3A_Law_for_Entrepreneurs/zz%3A_Back_Matter/10%3A_Index | Skip to main content
# Index
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• Was this article helpful? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8250440955162048, "perplexity": 138.25937373053284}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662619221.81/warc/CC-MAIN-20220526162749-20220526192749-00338.warc.gz"} |
http://hackage.haskell.org/package/simple-sessions-0.1.1/docs/src/Control-Concurrent-SimpleSession-Implicit.html | \section{Take 1: One Implicit Channel} \label{sec:implicit} \ignore{
> {-# LANGUAGE TypeOperators,
> MultiParamTypeClasses,
> FunctionalDependencies,
> FlexibleInstances,
> FlexibleContexts,
> UndecidableInstances #-}
>
> module Control.Concurrent.SimpleSession.Implicit (
> module Control.Concurrent.SimpleSession.SessionTypes,
> Session, Cap,
> io,
> send, recv, close, sel1, sel2, offer,
> enter, zero, suc, Pop(pop),
> Rendezvous, newRendezvous,
> accept, request
> ) where
>
> import Control.Concurrent.SimpleSession.TChan
> import Control.Concurrent.SimpleSession.UChan
> import Control.Concurrent.SimpleSession.SessionTypes
> newtype Session s s' a =
> Session { unSession :: UChan -> IO a }
The phantom parameters |s| and |s'| must track more information than just the current session. We define a type constructor |Cap| to hold not only the current session |r|, but another type |e|, which represents a session type environment:
> data Cap e r
The type |Cap e r| represents the capability to run the protocol |r|. The session type environment |e| provides context for any free variables |Var v| in |r|; that is, |r| must be closed in |e|. We discuss |e| in more detail when we explain recursion, and the other operations merely thread it through. We can now give |send| a type and definition that will work:
> send :: a -> Session (Cap e (a :!: r)) (Cap e r) ()
> send x = Session (\c -> unsafeWriteUChan c x)
Given an |a|, |send| evolves the session from |a :!: r| to |r|. In its implementation, |unsafeWriteUChan| indiscriminately transmits values of any type over an untyped channel. Thus, if we fail to ensure that the receiving process expects a value of type |a|, things can go very wrong. In \Section\ref{sec:theory}, we argue that this cannot happen. Predictably, |recv| requires the capability to receive an |a|, which it then produces:
> recv :: Session (Cap e (a :?: r)) (Cap e r) a
We use |close| to discard an exhausted capability, replacing it with |()|. In this implementation, |close| is a run-time no-op.
> close :: Session (Cap e Eps) () ()
> close = Session (\_ -> return ())
\paragraph{Composing computations.} We also need a way to compose |Session| computations. Composing a session from state $s_1$ to $s_2$ with a session from state $t_1$ to $t_2$ should be permitted only if $s_2 = t_1$. This is precisely the situation that \emph{indexed monads} capture. %include IxMonad.lhs The |IxMonad| instance for |Session| is then straightforward. It threads the implicit channel through and runs the underlying computations in the |IO| monad.
> instance IxFunctor Session where
> imap f m = Session (fmap f . unSession m)
>
> instance IxPointed Session where
> ireturn x = Session (const $return x) > > instance IxApplicative Session where > iap f x = Session (\r -> unSession f r ap unSession x r) > > instance IxMonad Session where > ibind k m = Session (\r -> unSession m r >>= \a -> > unSession (k a) r) < instance IxMonad Session where < ret a = Session (\_ -> return a) < m >>>= k = Session (\c -> do a <- unSession m c < unSession (k a) c) We use |io| to lift an arbitrary |IO| computation into |Session|: > io :: IO a -> Session s s a > io m = Session (\_ -> m) Because of |io|, this implementation is actually not linear but affine: an |IO| action may raise an exception and terminate the |Session| computation. Provided that exceptions cannot be caught within a |Session|, this does not jeopardize safety in the sense that any messages received will still have the expected representation. Some formulations of session types guarantee that a session, once initiated, will run to completion, but this seems unrealistic for real-world programs. Handling exceptions from within a session remains an open problem. \paragraph{Alternation.} The session actions |sel1|, |sel2|, and |offer| implement alternation. Action |sel1| selects the left side of an internal choice'', thereby replacing a session |r :+: s| with the session |r|; |sel2| selects the right side. On the other side of the channel, |offer| combines a |Session| computation for |r| with a computation for |s| into a computation that can handle |r :&: s|. Dynamically, |sel1| sends |True| over the channel, whereas |sel2| sends |False|, and |offer| dispatches on the boolean value received. > sel1 :: Session (Cap e (r :+: s)) (Cap e r) () > sel1 = Session (\c -> unsafeWriteUChan c True) > > sel2 :: Session (Cap e (r :+: s)) (Cap e s) () > sel2 = Session (\c -> unsafeWriteUChan c False) > > offer :: Session (Cap e r) u a -> > Session (Cap e s) u a -> > Session (Cap e (r :&: s)) u a > offer (Session m1) (Session m2) > = Session (\c -> do b <- unsafeReadUChan c > if b then m1 c else m2 c) \paragraph{Recursion.} Session actions |enter|, |zero|, and |suc| implement recursion. Consider the recursive session type < Request :!: Rec ((Response :?: Var Z) :&: Eps) from above. After sending a |Request|, we need some way to enter the body of the |Rec|, and upon reaching |Var Z|, we need some way to repeat the body of the |Rec|. We accomplish the former with |enter|, which strips the |Rec| constructor from |r| and pushes |r| onto the stack |e|: > enter :: Session (Cap e (Rec r)) (Cap (r, e) r) () > enter = Session (\_ -> return ()) In |e|, we maintain a stack of session types for the body of each enclosing |Rec|, representing an environment that closes over |r|. Upon encountering a variable occurence |Var |$n$, where$n$is a Peano numeral, we restore the$n$th session type from the stack and return the stack to its former state, using$n\$ expressed with |zero| and |suc|:
> zero :: Session (Cap (r, e) (Var Z))
> (Cap (r, e) r) ()
> zero = Session (\_ -> return ())
>
> suc :: Session (Cap (r, e) (Var (S v)))
> (Cap e (Var v)) ()
> suc = Session (\_ -> return ())
For example, if the current session is |Var (S (S Z))|, then the operation < suc >>> suc >>> zero pops two elements from the stack and replaces the current session with the body of the third enclosing |Rec|. It is worth remarking that this duplication of type and code to pop the stack is not strictly necessary. If we explicitly write |suc >>> suc >>> zero|, Haskell's type checker can infer |S (S Z)|. If, on the other hand, the type is already known, then a type class can do the work:\footnote{Note that the definition of the method |pop| is the same for both instances of |Pop|, which suggests that it could be provided as a default method. This would introduce a subtle bug, however, as it would enable defining new instances of |Pop| with arbitrary effect.}
> class Pop s s' | s -> s' where pop :: Session s s' ()
>
> instance Pop (Cap (r, e) (Var Z)) (Cap (r, e) r)
> where pop = Session (\_ -> return ())
>
> instance Pop (Cap e (Var v)) (Cap e' r') =>
> Pop (Cap (r, e) (Var (S v))) (Cap e' r')
> where pop = Session (\_ -> return ())
\paragraph{Putting it all together.} Finally, we need a way to connect and run sessions. A |Rendezvous| is a synchronization object that connects the types of two processes at compile time, and then enables their connection by a channel at run time. The |Rendezvous| carries a phantom parameter indicating the protocol to be spoken on the shared implicit channel, and is represented by a homogeneous, typed channel on which the untyped channel for a particular session will later be exchanged. Creating a |Rendezvous| is as simple as creating a new typed channel and wrapping it.
> newtype Rendezvous r = Rendezvous (TChan UChan)
>
> newRendezvous :: IO (Rendezvous r)
> newRendezvous = newTChan >>= return . Rendezvous
\par To accept a connection request, we need a |Rendezvous| object, and a |Session| computation whose starting session type matches that of the |Rendezvous|. The computation must deplete and close its channel. At run time, |accept| creates a new untyped channel on which the communication will take place and sends it over the |Rendezvous| channel. It then runs the session computation on the new channel.
> accept :: Rendezvous r ->
> Session (Cap () r) () a -> IO a
> accept (Rendezvous c) (Session f) = do
> nc <- newUChan
> writeTChan c nc
> f nc
\par To request a connection, the session type of the |Session| computation must be dual to that of the given |Rendezvous|. At run time, |request| receives a new, untyped channel from |accept| over the |Rendezvous| channel and then runs the computation using the channel.
> request :: Dual r r' => Rendezvous r ->
> Session (Cap () r') () a -> IO a
> request (Rendezvous c) (Session f)
> = readTChan c >>= f
%include ImplicitExample.lhs | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.1822632998228073, "perplexity": 12885.943053320225}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-18/segments/1429246640001.64/warc/CC-MAIN-20150417045720-00104-ip-10-235-10-82.ec2.internal.warc.gz"} |
http://www.codeproject.com/Articles/17980/Adding-iCalendar-Support-to-Your-Program-Part?msg=3634928 | 11,648,785 members (82,632 online)
#### Tagged as
, 14 Apr 2010 BSD 354.5K 2.2K 123
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## Introduction
This article describes how to load and view iCalendars by using the DDay.iCallibrary. I will cover more advanced topics, such as creating, editing, and serializing iCalendars in my next article.
In this article, I will walk you through creating a console application that will load and display upcoming events to the user. I've also included an example project that demonstrates how to add this kind of support to an ASP.NET web application.
## Background
Many programmers have worked with adding some kind of calendar support to an application - from displaying upcoming events on a web site, to allowing personalized calendars, with the ability to alter them.
So, thousands of programmers, all adding calendar support to their applications. So, what's the problem with that? The historical answer is that no (or very few) programmers followed any kind of standard to implement their calendars. So, if you needed to accomplish anything else with the calendar that your original application didn't support, you'd have to write it by hand.
Also, these ad-hoc calendars are only viewable from the application that wrote them. What if you want to allow for recurrences in your calendar, so an event can recur "every 2nd-to-last Sunday of the month?" What if you want to publish your calendar, so others can subscribe to it, and view it from the calendar program they prefer? What if you want to display and manipulate calendars from multiple sources, including sources that you may not have control over?
These are some of the problems the iCalendar standard solves for us. If you didn't already know -- iCalendar is a W3C recommendation known as RFC 5545. You can find it here.
## Using the Code
To begin, open Visual Studio and create a "Windows Console Application" project. Then, if you haven't already done so, download the latest binary version of DDay.iCalfrom SourceForge.net. Once you've done that, you simply need to add a reference to DDay.iCal.dll from your project (i.e. click "Add Reference" from the "Project" menu).
Then, add the following to the top of the Program.cs file:
using DDay.iCal;
You're now ready to load your first iCalendar! There are multiple ways you can load iCalendars, ranging from simply loading the file from your local filesystem, to loading from a WebDAV or CalDAV store, to loading from a database. The possibilities are endless; however, in this article, we'll focus on simply loading the file from your local filesystem. Add the following code to your Main() method (of course, replacing the path with the actual path to your iCalendar file).
// Load the calendar file
IICalendarCollection calendars = iCalendar.LoadFromFile(@"path\to\your\icalendar.ics");
Congratulations, you've loaded your iCalendar, and are ready to work with it! For now, let's display the events that occur today:
//
// Get all events that occur today.
//
IList&occurrence> occurrences = calendars.GetOccurrences
Console.WriteLine("Today's Events:");
// Iterate through each occurrence and display information about it
foreach (Occurrence occurrence in occurrences)
{
DateTime occurrenceTime = occurrence.Period.StartTime.Local;
IRecurringComponent rc = occurrence.Source as IRecurringComponent;
if (rc != null)
Console.WriteLine(rc.Summary + ": " + occurrenceTime.ToShortTimeString());
}
That's it! To be clear, calendars.GetOccurrences(...) returns a list of Occurrence objects. Occurrence objects describe each occurrence, including the date/time the occurrence happens, and a reference to the original component that generated the occurrence. We cast the Source of the occurrence to an IRecurringComponent, and display its properties.
So, now we've displayed all the events that occur today. Let's display all of the upcoming events that will occur within the next 7 days:
//
// Get all occurrences for the next 7 days, starting tomorrow.
//
occurrences = calendars.GetOccurrences
Console.WriteLine(Environment.NewLine + "Upcoming Events:");
foreach (Occurrence occurrence in occurrences)
{
DateTime occurrenceTime = occurrence.Period.StartTime.Local;
IRecurringComponent rc = occurrence.Source as IRecurringComponent;
if (rc != null)
Console.WriteLine(rc.Summary + ": " + occurrenceTime.ToString());
}
As you can see, this code is nearly identical to "Today's Events", with a slight difference at calendars.GetOccurrences(...). We also display the full date/time of the recurrence this time.
Note: If you're only interested in certain kinds of components (i.e. Events, Todos, etc.), then you can get occurrences for only those events using the generic version of GetOccurrences(i.e. calendars.GetOccurrences<IEvent>(...)).
## Final Code
Here's the final result of Program.cs:
using System;
using System.Collections.Generic;
using System.Text;
// Required DDay.iCal namespace
using DDay.iCal;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
//
// Get all events that occur today.
//
IList&occurrence> occurrences = calendars.GetOccurrences
Console.WriteLine("Today's Events:");
// Iterate through each occurrence and display information about it
foreach (Occurrence occurrence in occurrences)
{
DateTime occurrenceTime = occurrence.Period.StartTime.Local;
IRecurringComponent rc = occurrence.Source as IRecurringComponent;
if (rc != null)
Console.WriteLine(rc.Summary + ": " +
occurrenceTime.ToShortTimeString());
}
//
// Get all occurrences for the next 7 days, starting tomorrow.
//
occurrences = calendars.GetOccurrences
Console.WriteLine(Environment.NewLine + "Upcoming Events:");
foreach (Occurrence occurrence in occurrences)
{
DateTime occurrenceTime = occurrence.Period.StartTime.Local;
IRecurringComponent rc = occurrence.Source as IRecurringComponent;
if (rc != null)
Console.WriteLine(rc.Summary + ": " + occurrenceTime.ToString());
}
}
}
}
## Points of Interest
For more information, visit the DDay.iCalhomepage at ddaysoftware.com.
Many apologies that it's taken so long to update this article. I'll now be providing more frequent updates.
## History
• 04/14/2010 - Updated to version 1.0 Alpha
• 03/09/2007 - Posted
## Share
Web Developer United States
Doug has been a Software Engineer for 7 of the previous 9 years, and has 12 years of programming experience.
For the past 3 years, he has been developing custom applications in C# and Visual Basic.NET, with an emphasis on custom cross-Internet applications for IT management, real-time collaboration, and process management and reporting.
## You may also be interested in...
First PrevNext
ICalendar Support for Visual Basic Member 1145177814-Feb-15 0:18 Member 11451778 14-Feb-15 0:18
does this work with VS2012 and windows phone 8? kunwar_9124-Sep-13 8:39 kunwar_91 24-Sep-13 8:39
Help for newbie with errors line 20 ptsmh10-Nov-11 9:49 ptsmh 10-Nov-11 9:49
Sample or guidance on creating / reading VFREEBUSY rw_architect9-Sep-10 13:22 rw_architect 9-Sep-10 13:22
Re: Sample or guidance on creating / reading VFREEBUSY Douglas Day10-Sep-10 4:30 Douglas Day 10-Sep-10 4:30
Re: Sample or guidance on creating / reading VFREEBUSY rw_architect16-Oct-10 5:19 rw_architect 16-Oct-10 5:19
Hello Doug, I completely understand. I too am short of time right now. I do need to implement VFREEBUSY as part of a larger solution I'm working on and have been studying up on it's structure. When I complete the implementation, I will gladly send you the code. Thanks for your help and for sharing this library. - Randolph
Re: Sample or guidance on creating / reading VFREEBUSY Douglas Day26-Oct-10 10:33 Douglas Day 26-Oct-10 10:33
VB.Net Example1 variable declaration errors... rw_architect5-Sep-10 17:07 rw_architect 5-Sep-10 17:07
Re: VB.Net Example1 variable declaration errors... Douglas Day7-Sep-10 5:09 Douglas Day 7-Sep-10 5:09
Re: VB.Net Example1 variable declaration errors... Douglas Day7-Sep-10 5:18 Douglas Day 7-Sep-10 5:18
Re: VB.Net Example1 variable declaration errors... rw_architect9-Sep-10 12:55 rw_architect 9-Sep-10 12:55
Re: VB.Net Example1 variable declaration errors... Douglas Day9-Sep-10 13:00 Douglas Day 9-Sep-10 13:00
Would be nice if article could be updated for version 0.80 manudurand14-Mar-10 1:52 manudurand 14-Mar-10 1:52
Re: Would be nice if article could be updated for version 0.80 Douglas Day14-Mar-10 10:30 Douglas Day 14-Mar-10 10:30
Re: Would be nice if article could be updated for version 0.80 manudurand14-Mar-10 16:21 manudurand 14-Mar-10 16:21
Re: Would be nice if article could be updated for version 0.80 Douglas Day14-Mar-10 17:01 Douglas Day 14-Mar-10 17:01
Re: Would be nice if article could be updated for version 0.80 manudurand14-Mar-10 19:50 manudurand 14-Mar-10 19:50
Re: Would be nice if article could be updated for version 0.80 Douglas Day15-Mar-10 5:24 Douglas Day 15-Mar-10 5:24
Re: Would be nice if article could be updated for version 0.80 Douglas Day15-Apr-10 6:06 Douglas Day 15-Apr-10 6:06
great article jael3624-Nov-09 9:55 jael36 24-Nov-09 9:55
Re: great article Douglas Day29-Dec-09 10:01 Douglas Day 29-Dec-09 10:01
Thanks Member 45575835-Aug-09 3:23 Member 4557583 5-Aug-09 3:23
Re: Thanks Douglas Day5-Aug-09 4:12 Douglas Day 5-Aug-09 4:12
Event.OccursOn and events that span two UTC days but is only 2 hours long i.i. wiin30-Apr-09 14:38 i.i. wiin 30-Apr-09 14:38
Last Visit: 31-Dec-99 18:00 Last Update: 4-Aug-15 20:40 Refresh 123 Next » | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.1829315721988678, "perplexity": 9871.065858820479}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438044160065.87/warc/CC-MAIN-20150728004240-00141-ip-10-236-191-2.ec2.internal.warc.gz"} |
https://gateway.ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Probability_density_function.html | Probability density function
Boxplot and probability density function of a normal distribution N(0,σ2).
Geometric visualisation of the mode, median and mean of an arbitrary probability density function.[1]
In probability theory, a probability density function (PDF), or density of a continuous random variable, is a function, whose value at any given sample (or point) in the sample space (the set of possible values taken by the random variable) can be interpreted as providing a relative likelihood that the value of the random variable would equal that sample. In other words, while the absolute likelihood for a continuous random variable to take on any particular value is 0 (since there are an infinite set of possible values to begin with), the value of the PDF at two different samples can be used to infer that, in any particular draw of the random variable, how much more likely it is that the random variable would equal one sample compared to the other sample.
In a more precise sense, the PDF is used to specify the probability of the random variable falling within a particular range of values, as opposed to taking on any one value. This probability is given by the integral of this variable’s PDF over that rangethat is, it is given by the area under the density function but above the horizontal axis and between the lowest and greatest values of the range. The probability density function is nonnegative everywhere, and its integral over the entire space is equal to one.
The terms "probability distribution function"[2] and "probability function"[3] have also sometimes been used to denote the probability density function. However, this use is not standard among probabilists and statisticians. In other sources, "probability distribution function" may be used when the probability distribution is defined as a function over general sets of values, or it may refer to the cumulative distribution function, or it may be a probability mass function (PMF) rather than the density. Further confusion of terminology exists because density function has also been used for what is here called the "probability mass function" (PMF).[4] In general though, the PMF is used in the context of discrete random variables (random variables that take values on a discrete set), while PDF is used in the context of continuous random variables.
Example
Suppose a species of bacteria typically lives 4 to 6 hours. What is the probability that a bacterium lives exactly 5 hours? The answer is 0%. A lot of bacteria live for approximately 5 hours, but there is no chance that any given bacterium dies at exactly 5.0000000000... hours.
Instead we might ask: What is the probability that the bacterium dies between 5 hours and 5.01 hours? Let's say the answer is 0.02 (i.e., 2%). Next: What is the probability that the bacterium dies between 5 hours and 5.001 hours? The answer is probably around 0.002, since this is 1/10th of the previous interval. The probability that the bacterium dies between 5 hours and 5.0001 hours is probably about 0.0002, and so on.
In these three examples, the ratio (probability of dying during an interval) / (duration of the interval) is approximately constant, and equal to 2 per hour (or 2 hour−1). For example, there is 0.02 probability of dying in the 0.01-hour interval between 5 and 5.01 hours, and (0.02 probability / 0.01 hours) = 2 hour−1. This quantity 2 hour−1 is called the probability density for dying at around 5 hours.
Therefore, in response to the question "What is the probability that the bacterium dies at 5 hours?", a literally correct but unhelpful answer is "0", but a better answer can be written as (2 hour−1) dt. This is the probability that the bacterium dies within a small (infinitesimal) window of time around 5 hours, where dt is the duration of this window.
For example, the probability that it lives longer than 5 hours, but shorter than (5 hours + 1 nanosecond), is (2 hour−1)×(1 nanosecond) ≃ 6×10−13 (using the unit conversion 3.6×1012 nanoseconds = 1 hour).
There is a probability density function f with f(5 hours) = 2 hour−1. The integral of f over any window of time (not only infinitesimal windows but also large windows) is the probability that the bacterium dies in that window.
Absolutely continuous univariate distributions
A probability density function is most commonly associated with absolutely continuous univariate distributions. A random variable X has density fX, where fX is a non-negative Lebesgue-integrable function, if:
Hence, if FX is the cumulative distribution function of X, then:
and (if fX is continuous at x)
Intuitively, one can think of fX(x) dx as being the probability of X falling within the infinitesimal interval [x, x + dx].
Formal definition
(This definition may be extended to any probability distribution using the measure-theoretic definition of probability.)
A random variable X with values in a measurable space (usually Rn with the Borel sets as measurable subsets) has as probability distribution the measure XP on : the density of X with respect to a reference measure μ on is the Radon–Nikodym derivative:
That is, f is any measurable function with the property that:
for any measurable set .
Discussion
In the continuous univariate case above, the reference measure is the Lebesgue measure. The probability mass function of a discrete random variable is the density with respect to the counting measure over the sample space (usually the set of integers, or some subset thereof).
Note that it is not possible to define a density with reference to an arbitrary measure (e.g. one can't choose the counting measure as a reference for a continuous random variable). Furthermore, when it does exist, the density is almost everywhere unique.
Further details
Unlike a probability, a probability density function can take on values greater than one; for example, the uniform distribution on the interval [0, ½] has probability density f(x) = 2 for 0 x ½ and f(x) = 0 elsewhere.
The standard normal distribution has probability density
If a random variable X is given and its distribution admits a probability density function f, then the expected value of X (if the expected value exists) can be calculated as
Not every probability distribution has a density function: the distributions of discrete random variables do not; nor does the Cantor distribution, even though it has no discrete component, i.e., does not assign positive probability to any individual point.
A distribution has a density function if and only if its cumulative distribution function F(x) is absolutely continuous. In this case: F is almost everywhere differentiable, and its derivative can be used as probability density:
If a probability distribution admits a density, then the probability of every one-point set {a} is zero; the same holds for finite and countable sets.
Two probability densities f and g represent the same probability distribution precisely if they differ only on a set of Lebesgue measure zero.
In the field of statistical physics, a non-formal reformulation of the relation above between the derivative of the cumulative distribution function and the probability density function is generally used as the definition of the probability density function. This alternate definition is the following:
If dt is an infinitely small number, the probability that X is included within the interval (t, t + dt) is equal to f(t) dt, or:
Link between discrete and continuous distributions
It is possible to represent certain discrete random variables as well as random variables involving both a continuous and a discrete part with a generalized probability density function, by using the Dirac delta function. For example, let us consider a binary discrete random variable having the Rademacher distributionthat is, taking −1 or 1 for values, with probability ½ each. The density of probability associated with this variable is:
More generally, if a discrete variable can take n different values among real numbers, then the associated probability density function is:
where x1, …, xn are the discrete values accessible to the variable and p1, …, pn are the probabilities associated with these values.
This substantially unifies the treatment of discrete and continuous probability distributions. For instance, the above expression allows for determining statistical characteristics of such a discrete variable (such as its mean, its variance and its kurtosis), starting from the formulas given for a continuous distribution of the probability.
Families of densities
It is common for probability density functions (and probability mass functions) to be parametrizedthat is, to be characterized by unspecified parameters. For example, the normal distribution is parametrized in terms of the mean and the variance, denoted by and respectively, giving the family of densities
It is important to keep in mind the difference between the domain of a family of densities and the parameters of the family. Different values of the parameters describe different distributions of different random variables on the same sample space (the same set of all possible values of the variable); this sample space is the domain of the family of random variables that this family of distributions describes. A given set of parameters describes a single distribution within the family sharing the functional form of the density. From the perspective of a given distribution, the parameters are constants, and terms in a density function that contain only parameters, but not variables, are part of the normalization factor of a distribution (the multiplicative factor that ensures that the area under the densitythe probability of something in the domain occurring equals 1). This normalization factor is outside the kernel of the distribution.
Since the parameters are constants, reparametrizing a density in terms of different parameters, to give a characterization of a different random variable in the family, means simply substituting the new parameter values into the formula in place of the old ones. Changing the domain of a probability density, however, is trickier and requires more work: see the section below on change of variables.
Densities associated with multiple variables
For continuous random variables X1, …, Xn, it is also possible to define a probability density function associated to the set as a whole, often called joint probability density function. This density function is defined as a function of the n variables, such that, for any domain D in the n-dimensional space of the values of the variables X1, …, Xn, the probability that a realisation of the set variables falls inside the domain D is
If F(x1, …, xn) = Pr(X1 x1, …, Xn xn) is the cumulative distribution function of the vector (X1, …, Xn), then the joint probability density function can be computed as a partial derivative
Marginal densities
For i=1, 2, …,n, let fXi(xi) be the probability density function associated with variable Xi alone. This is called the “marginal” density function, and can be deduced from the probability density associated with the random variables X1, …, Xn by integrating on all values of the n 1 other variables:
Independence
Continuous random variables X1, …, Xn admitting a joint density are all independent from each other if and only if
Corollary
If the joint probability density function of a vector of n random variables can be factored into a product of n functions of one variable
(where each fi is not necessarily a density) then the n variables in the set are all independent from each other, and the marginal probability density function of each of them is given by
Example
This elementary example illustrates the above definition of multidimensional probability density functions in the simple case of a function of a set of two variables. Let us call a 2-dimensional random vector of coordinates (X, Y): the probability to obtain in the quarter plane of positive x and y is
Dependent variables and change of variables
If the probability density function of a random variable X is given as fX(x), it is possible (but often not necessary; see below) to calculate the probability density function of some variable Y = g(X). This is also called a “change of variable” and is in practice used to generate a random variable of arbitrary shape fg(X) = fY using a known (for instance uniform) random number generator.
If the function g is monotonic, then the resulting density function is
Here g−1 denotes the inverse function.
This follows from the fact that the probability contained in a differential area must be invariant under change of variables. That is,
or
For functions which are not monotonic the probability density function for y is
where n(y) is the number of solutions in x for the equation g(x) = y, and g−1k(y) are these solutions.
It is tempting to think that in order to find the expected value E(g(X)) one must first find the probability density fg(X) of the new random variable Y = g(X). However, rather than computing
The values of the two integrals are the same in all cases in which both X and g(X) actually have probability density functions. It is not necessary that g be a one-to-one function. In some cases the latter integral is computed much more easily than the former. See Law of the unconscious statistician.
Multiple variables
The above formulas can be generalized to variables (which we will again call y) depending on more than one other variable. f(x1, …, xn) shall denote the probability density function of the variables that y depends on, and the dependence shall be y = g(x1, …, xn). Then, the resulting density function is
where the integral is over the entire (n-1)-dimensional solution of the subscripted equation and the symbolic dV must be replaced by a parametrization of this solution for a particular calculation; the variables x1, …, xn are then of course functions of this parametrization.
This derives from the following, perhaps more intuitive representation: Suppose x is an n-dimensional random variable with joint density f. If y = H(x), where H is a bijective, differentiable function, then y has density g:
with the differential regarded as the Jacobian of the inverse of H, evaluated at y.
Using the delta-function (and assuming independence) the same result is formulated as follows.
If the probability density function of independent random variables Xi, i = 1, 2, …n are given as fXi(xi), it is possible to calculate the probability density function of some variable Y = G(X1, X2, …Xn). The following formula establishes a connection between the probability density function of Y denoted by fY(y) and fXi(xi) using the Dirac delta function:
Sums of independent random variables
Not to be confused with Mixture distribution
The probability density function of the sum of two independent random variables U and V, each of which has a probability density function, is the convolution of their separate density functions:
It is possible to generalize the previous relation to a sum of N independent random variables, with densities U1, …, UN:
This can be derived from a two-way change of variables involving Y=U+V and Z=V, similarly to the example below for the quotient of independent random variables.
Products and quotients of independent random variables
Given two independent random variables U and V, each of which has a probability density function, the density of the product Y=UV and quotient Y=U/V can be computed by a change of variables.
Example: Quotient distribution
To compute the quotient Y=U/V of two independent random variables U and V, define the following transformation:
Then, the joint density p(Y,Z) can be computed by a change of variables from U,V to Y,Z, and Y can be derived by marginalizing out Z from the joint density.
The inverse transformation is
The Jacobian matrix of this transformation is
Thus:
And the distribution of Y can be computed by marginalizing out Z:
Note that this method crucially requires that the transformation from U,V to Y,Z be bijective. The above transformation meets this because Z can be mapped directly back to V, and for a given V the quotient U/V is monotonic. This is similarly the case for the sum U+V, difference U-V and product UV.
Exactly the same method can be used to compute the distribution of other functions of multiple independent random variables.
Example: Quotient of two standard normals
Given two standard normal variables U and V, the quotient can be computed as follows. First, the variables have the following density functions:
We transform as described above:
This is a standard Cauchy distribution.
Uses as position probability density:
Bibliography
The first major treatise blending calculus with probability theory, originally in French: Théorie Analytique des Probabilités.
The modern measure-theoretic foundation of probability theory; the original German version (Grundbegriffe der Wahrscheinlichkeitsrechnung) appeared in 1933.
• Patrick Billingsley (1979). Probability and Measure. New York, Toronto, London: John Wiley and Sons. ISBN 0-471-00710-2.
• David Stirzaker (2003). Elementary Probability. ISBN 0-521-42028-8.
Chapters 7 to 9 are about continuous variables.
1. "AP Statistics Review - Density Curves and the Normal Distributions". Retrieved 16 March 2015.
2. Probability distribution function PlanetMath
3. Ord, J.K. (1972) Families of Frequency Distributions, Griffin. ISBN 0-85264-137-0 (for example, Table 5.1 and Example 5.4) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9780905842781067, "perplexity": 262.575968575247}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500080.82/warc/CC-MAIN-20230204012622-20230204042622-00578.warc.gz"} |
http://www.math-problems.org/2nd-grade-math-word-problems.html | # 2nd Grade Math Word Problems
Creating an interest in math early on helps students develop math solving skills and develop confidence in their math abilities. The internet is a great way for students to reach out to tutors and peers to get help with their school work. Math help websites abound in problems, examples and worksheets which help students understand the subject better. Math word problems in particular, can pose a challenge to students, especially if they are just beginning to learn math. Math word problems are basically just the numbers and functions spelt out verbally. 2nd grade math word problems often pose a challenge to young students just starting out on learning the subject. Free math word problems for the 2nd grade are found on math help sites, which also help students by teaching them how to understand the question. These websites contain plenty of helpful tips and hints on how to pick out the necessary information from the question.
## Math Word Problems 2nd Grade
Math 2nd grade word problems are easy to do once you get the method of solving them right. Students can find lots of practice math word problems for the 2nd grade online. You will also find simple explanations and solved examples which help students understand how to solve these problems. Online worksheets have any number of 2nd grade math problems; practice them whenever you want to get an edge in your math solving skills.
Online math solvers also help students with their homework. So next time you’re trying to figure exactly what that question means, try an online math helper who will help you solve the questions and provide answers so that you know your work is correct. You can also use math solvers to get help during exams and test prep along with mock tests which will assess your grasp on the subject.
### Solved Examples
Question 1: There are 10 rows of tea cups. Each row has 3 cups. How many cups are there altogether?
Solution:
Total number of rows = 10
Number of cups contain by each row = 3
=> Number of cups are = Total number of rows * Number of cups contain by each row
= 10 * 3
= 30
Hence there are 30 cups.
Question 2: Briteny has 32 marbles. She got 10 marbles from Jarin and 12 from Janita. How many marbles given by Jany to her.
Solution:
Number of marbles she have = 32
Number of marbles given by Jarin = 10
Number of marbles given by Janita = 12
=> Number of marbles given by Jany = Number of marbles she have - (Number of marbles given by Jarin + Number of marbles given by Janita)
= 32 - (10 + 12)
= 32 - 22
= 10
Hence Jany gave her 10 marbles.
Question 3: There are 2 cakes. Each cake is cut into 4 pieces. How many pieces are there in all?
Solution:
Number of cakes = 2
Pieces of one cake = 4
=> Total number of pieces = Number of cakes * Pieces of one cake
= 2 * 4
= 8
Hence there are 8 pieces in all.
Question 4: Sujain has 27 dollars. Each clip costs 3 dollar. How many clips can she buy.
Solution:
Since Sujain have 27 dollars
Cost of each clip = 3 dollar
=> Number of clips she can buy = $\frac{27}{3}$ = 9
=> She can buy 9 clips. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4447218179702759, "perplexity": 1176.6692034454954}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320130.7/warc/CC-MAIN-20170623184505-20170623204505-00516.warc.gz"} |
https://docs.quantumatk.com/tutorials/deposition_si/deposition_si.html | # Simulating Si Deposition using Silane¶
Version: R-2020.09-SP1
In this tutorial, we will look at a QuantumATK workflow to simulate the reaction mechanisms involved in the deposition of Si using silane. We will perform surface-science style slab calculations using plane-wave DFT to study the adsorption and dissociation of silane along with the formation and desorption of H2 from the surface.
## Background¶
Using thermal chemical vapor deposition (TCVD) technique, Si is deposited by gas phase pyrolysis of SiH4 . SiH4 molecules impinge on the Si substrate and donates H atoms to the Si surface followed by the deposition of SiHx . The H atoms on the surface form H2 molecules and desorb at elevated temperatures. This is the process we will simulate in this tutorial following the reference article [LRHL16]. This can be done in 3 steps. Step 1 involves computing the reference bare Si(100) surface in a supercell and an SiH4 molecule in the gas phase. In step 2, we study the adsorption and dissociation of SiH4 on the relaxed Si(100) surface. Step 3 concerns the formation and desorption of an H2 molecule from the Si surface.
## Getting started¶
Open the QuantumATK GUI, NanoLab, and select ‘Create New…’ in the Project Dialog. Create a new project in an empty folder with an appropriate name.
## Step 1: Reference Calculations¶
We will perform calculations for the reference SiH4 molecule and the bare Si(100) surface using a similar setup as the reference article [LRHL16]. The relevant python scripts are found here SiH4.py, Si-alpha-100.py. Panel a in the figure below shows the SiH4 molecule in a simulation box. Panel b in the figure shows the side and top views of the reconstructed Si(100) surface. From the top view one can see the Si-dimer formation on the surface and these are the reactive sites for SiH4 adsorption and dissociation. Total electronic energies of these two calculations are summed up to give the reference energy value of the noninteracting system for adsorption energy calculations. The adsorption energy is the difference between the total energy after the process step (interacting) and before the process step (noninteracting) energies:
$E_{\rm{adsorption/ binding}} = E_{\rm{interacting}} - E_{\rm{noninteracting}}$
## Step 2: Adsorption and Dissociation of SiH4¶
Next step is to adsorb an SiH4 molecule on the reconstructed Si surface and study the interaction between the two. Panel a in the figure below shows the adsorbed state of SiH4 on the Si surface in which the molecule is intact and only a weak binding energy of -2.99 kcal/mol (reference article: -2.6 kcal/mol). Panel b in the figure shows a dissociated state of SiH4 in which a Si-H bond from the molecule dissociates and forms a surface bound Si-H and SiH3 species. The dissociated state has a binding energy of -41.27 kcal/mol (reference article: -41.3 kcal/mol) which is exoergic and thus favorable. Panel c shows another dissociated Si-H bond from the SiH3 fragment and formation of 2 Si-H species on the surface in total with a binding energy of -58.11 kcal/mol (reference article: -58.2 kcal/mol). On the reconstructed surface, there are two Si dimers. The SiH2 fragment takes the bridge site along one of the two surface Si dimers and the H atoms bind to the Si atoms of the other dimer. The scripts to run these geometry optimizations can be downloaded here: SiH4-Si.py, SiH3-SiH.py, SiH2-2SiH.py. A python script to compute the binding energies of these geometries can be downloaded here adsorption_energies.py.
Now we can compute the dissociation pathways from the intact adsorbed state (a) towards the two dissociated states (b and c) shown in the picture above. For this we will use the climbing image nudged elastic band approach implemented in QuantumATK. We have used 4 interpolated images between (a and b) and between (b and c). The relevant scripts to run these calculations can be downloaded here: NEB-a-b.py, NEB-b-c.py. The converged pathways with a maximum force on atoms within 0.1 eV/Å are shown in the animated gifs below. The activation barrier for the first H dissociation connecting geometries a and b is a very low value of 2.67 kcal/mol (reference aricle: 5.2 kcal/mol). This process should not require high temperatures to proceed spontaneously.
The second H dissociation pathways connecting b and c has an activation barrier of 32.6 kcal/mol (reference article: 31.1 kcal/mol). This pathway requires elevated temperatures to breach the energy barrier.
## Step 3: Formation and Desorption of H2¶
The H atoms on the surface can diffuse on the Si surface and form H2 molecule and desorb from the surface. This would then result in the deposition of Si and the removal of H ensures further adsorption of silane molecules on the surface. To study this process, we modified geometry c to have a H2 molecule adsorbed on the Si surface instead of two separated H atoms. A python script for this calculation can be downloaded here SiH2-H2.py. This calculation resulted in the newly created H2 molecule desorbing into the vacuum spontaneously upon optimization as shown in the below animation.
This means that there is no activation barrier for the desorption of an H2 molecule once it is formed on the surface. However, there will be an activation barrier for the diffusion of H on the surface which we will compute next. For this, we choose geometry b from before and compute the activation barrier for the diffusion of H from the atop Si site of one dimer to the other as shown in the animation below. The calculated energy barrier is computed to be 36.5 kcal/mol (reference article - Fig.4 TS2: 34.8 kcal/mol). This is a large barrier, however, it is known to be breached at a temperature of 570 K [OBG+96].
## Conclusions¶
In this tutorial, we computed the energetics related to the mechanisms involved in the Si deposition process and compared the results to a previously published article that used a different PAW based plane-wave DFT code. We showed an excellent agreement with the published research article. This tutorial demonstrates the capabilities of QuantumATk in modeling the complex mechanisms involved in thin film processing.
## References¶
[LRHL16] (1, 2) Thong N.-M. Le, P. Raghunath, Lam K. Huynh, and M. C. Lin. A computational study on the adsorption configurations and reactions of SiHx(x=1-4) on clean and H-covered Si(100) surfaces. Appl. Surf. Sci., 387:546 – 556, 2016. URL: http://www.sciencedirect.com/science/article/pii/S0169433216313289, doi:https://doi.org/10.1016/j.apsusc.2016.06.099.
[OBG+96] J. H. G. Owen, D. R. Bowler, C. M. Goringe, K. Miki, and G. A. D. Briggs. Hydrogen diffusion on si(001). Phys. Rev. B, 54:14153–14157, Nov 1996. URL: https://link.aps.org/doi/10.1103/PhysRevB.54.14153, doi:10.1103/PhysRevB.54.14153. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6969205737113953, "perplexity": 2472.140100113893}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780057039.7/warc/CC-MAIN-20210920131052-20210920161052-00104.warc.gz"} |
https://chemistry.stackexchange.com/questions/28190/why-does-phosphorus-makes-5-bonds-with-oxygen-in-p4o10-whereas-3-bonds-in-p4o6/32225 | # why does phosphorus makes 5 bonds with oxygen in P4O10 whereas 3 bonds in P4O6?
how phosphorus forms 2 types of bonds with oxygen i.e. 5 in $\ce{P4O10}$ and 3 in $\ce{P4O6}$ when only three are needed to complete its octet?
• Did you consider the different oxidation states of phosphorus in both oxides? – Klaus-Dieter Warzecha Apr 3 '15 at 10:22
• Welcome to chemistry.SE! I wouldn't rely too much on octet if I were you, especially when it's about phosphorus. Your question won't make sense if we not rely on octet, which is the case about group 15. – M.A.R. Apr 3 '15 at 10:40
• @Ϻ.Λ.Ʀ. -- too bad there's no such simple reply for Cu(OH)2. I mean, as simple as Chinmay's. – CowperKettle Jan 28 '16 at 17:54 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.37066522240638733, "perplexity": 2093.138386581438}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986657949.34/warc/CC-MAIN-20191015082202-20191015105702-00282.warc.gz"} |
https://research.web3.foundation/en/latest/polkadot/XCMP/Opening_closing%20XCMP%20Channel.html | # Opening/closing XCMP Channel¶
This write up describes how XCMP channels are opened and closed.
Definition[Unidirection XCMP Channel] In this type of channel messages flow only in one direction. Each channel has its unique configuration. Agreeing on opening/closing of the channel and the configurations of the channel is still done by both sides. The deposit can put down by both or one party.
Definition[Bidirectional XCMP Channel] In this type of channel messages can flow in both directions. The configuration for this channel will be the same for both directions, which means that one side cannot send more messages than the other side. The deposit can be put down by one or both sides.
The trade-off is that unidirectional channel type is more flexible and bidirectional channel type is more efficient in terms of openin and closing the channels. However, note that in bidirectional channel types there might be more need for interaction to agree on configurations and how to split the deposit of the channel.
For this writeup we assume XCMP channels are unidirectioonal, mainly because of the flexibility it gives us.
When opening a channel a deposit needs to be put down. The deposit is locked as long as the request for the channel is not withdrawn or the channel is still open. In this document, we denote the initiator of the channel as party $$A$$ and the other party of the (potential) channel as party $$B$$. Note that both parties are able to send and receive.
To open a channel both parties $$A$$, $$B$$ have to agree to the opening of the channel, however, closing a channel can be done from one side. Since messages that are not acted on yet or are still being routed when the closing of channels are signaled, we need to incorporate two types of delay. For opening a channel, this delay should be high enough such that party $$B$$ has enough time to potentially close existing channels in case it has reached its limit of total channels. For closing a channel a delay is important to ensure that messages are not lost in the time needed to ensure both sides are aware of the closing.
A channel is opened after party $$B$$ acknowledges the channel.
We need to have two delays $$D$$ and $$\delta$$ defined by the network (to ensure that channels obey at least that delay). This delay should depend on the time it takes for a change in the relay chain be noticed by a parachain and the time it takes for messages on the way to arrive.
## Opening can works as follows:¶
Phase 0: A parachain can initiate a channel to another parachain by sending an upward init_open_channel message to the relay chain, that includes:
• The recipient’s (party $$B$$) parachain/parathread ID
• Conditions for closing that channel: define a local delay $$\delta$$ such that $$\delta >= D$$, how many messages can be sent before any of them is received (basically size of buffer that either end needs), size of messages maybe (!).
Phase 1: This upward message will add an entry to $$A$$’s parachain CST on the relay chain. In this table every entry has information such as the recipient parachain ID, configurations such as the size or number of messages allowed on this channel, and the status of the channel that can be “open”, “pending open”, “pending closing”, and “closing - receiving messages”. At this stage the status of the channel will be set to “pending open”. Note that recipient party $$B$$ needs to also lock a predefined amount of funds for this channel.
Phase 2: Once the relay chain sees such a message it needs to send a downward message to the party $$B$$’s parachain that includes the metadata of the channel (see above), that consists of the parachain ID of initiator $$A$$, the sizes and number of messages.
Phase 3: If $$B$$’s parachain has less than the limit (which is currently set at 100 channels) and is willing to have a channel open with the iniator parachain $$A$$, it needs to send an upward accept_open_channel message to the relay chain. This upward message includes the metadata it was sent earlier.
Phase 4: Once the relay chain receives the accept_open_channel message it needs to check whether the metadata sent by $$B$$’s message is in accordance with the created entry in $$A$$’s parachain CST entry that was created earlier for this purpose. If it does, the status in $$A$$’s CST entry corresponding to this channel is set to “open”. A corresponding entry in $$B$$’s CST is also created with the status “open”. This should be followed by a generation of a default first entry for the channel in the CST: both $$A$$’s and $$B$$’s parachain get an entry in the CST with the all-zero bitstring (so the tuple: (0x00..00, 00).
Phase 4’:If $$B$$’s parachain does not respond to the relay chain message, $$A$$ can withdraw its channel initiation at any moment and get their funds released. Note there needs to be a minimum time passed between initating an opening of a channel and withdrawing this request to avoid race conditions.
## Closing can work as follows:¶
Let us assume there is a unidirection channel between $$A$$ and $$B$$ and $$A$$ wants to close this channel. In this section, we denote the initator of the closure by party $$A$$ and the other side of the channel with party $$B$$.
Phase 0: Party $$A$$ can send the request for closure as an upward init_close_channel message to the relay chain. After this point no new XCMP messages of $$A$$’s parachain are accepted for that channel.
Phase 1: On the relay chain the status of the channel becomes “pending closing”.
Phase 2: The relay chain sends a downward message to $$B$$’s parachain to signal closing.
Phase 3: $$B$$’s parachain has up to $$D$$ time slots after the close initialisation (or some other definition of time) to react, by acting on all left open messages in the queue plus potentially sending new messages (for the last time) to $$A$$’s parachain. It then can end the channel with some accept_close_channel message. After this point $$B$$’s parachain cannot send messages on this channel. Once $$B$$ has sent this message we can go to Phase 5.
Phase 4: In case $$B$$ does not respond, we need to wait for $$D$$ time to make sure $$B$$ has time to notice the closing process.
Phase 5: Once this timeout is finished or $$B$$ has sent an acklodegement: Either $$A$$ needs to have received and acted on all messages that were sent by $$B$$ until the end of the previous timeout or another timeout $$\delta$$ needs to pass (basically Phase 3 or 4, which ever happens first). During Phase 5, the status of the channel is “closing - receiving messages”.
With waiting for messages to be received, we can prove that they have been using the watermark, which means that we optimistically we can close much faster than the timeout. In particular, with parathreads, the not sending delay can be shorter than their average block time, but the delay for receiving cannot be. We’d close channels between two parathreads a lot faster if these were different numbers.
Phase 6: At this stage all messages in $$A$$’s queue are dropped and the channel is closed. The other parachain, $$B$$, is not able to respond (via XCMP). But the participants in the channel could of course make other agreements for this situation.
Phase 7: Now the entries can be deleted in channel metadata table of both $$A$$ and $$B$$ on the relay chain. And also on the corresponding CST tables. The deposit for this channel will be released to boths sides of the channel.
• How much does it cost to open a channel?
• Answer: A sensible cost for the relay chain time plus a more significant deposit. The deposit should scale to limit the total number of channels.
• Follow-up questions: Who pays the deposit? Is it paid out of the parachain bond? What about for parathreads?
• Answer: The deposit is paid out of the parachain account and the same for parathreads. Paras do have DOTs that are not locked for their bond, right?
• Are you imagining an exponential ramp-up of cost/deposit? How should the costs differ based on channel capacity?
• Answer: Np, we are imagining a fixed cost per channel for now. The storage /throughput on the relay chain side do not depend on the channel capacity, so the relay chain deposit and costs will not do either.
• How many channels can any para open at any time? Should this be different for chains and threads?
• Answer: It’s different for chains and threads. The plan was 100 per thread and chains unlimited, but the deposit should put an economic limit.
• What are the guarantees about message delivery in channels? Are these guarantees upheld at channel-closing or the sender-para being offboarded?
• Answer: Channel closing is planned to be slow to give the receiver a chance to receive messages. We have no plans to keep messages beyond sender offboarding.
• An alternative to our design above would be to move message data from relay chain state associated with the sender to that of the receiver. That would deal with the off-boarding issue, but require more code complexity. I think this is not part of the XCMP MVP and we should implement it later if at all.
• Another alternative is for there to be a downwards message to the receiver in the event that removing data from the senders’ CST row causes messages to be dropped.
• However both of these would be really expensive if a chain with many channels was off-boarded. If possible, it would be better to keep the chain metadata around for the channel closing timeout and trigger the closing process for all channels. Then you just have the problem of how to delay the clean up.
• What information does a para receive about messages lost when a channel is closed? On either the sending or receiving side of the channel?
• Answer: Unless we change the design above, none. It’s unclear how we could send information to both sides because then we are not sure if anything is actually dropped.
• How are open channels handled when a para migrates from chain to thread or vice-versa?
• Answer: For thread to chain, we should just keep them open. For chain to thread, we should either keep them all open or introduce more states. Whatever we do, there should be no messages dropped as a result. We should code doing nothing and then fix it later.
• The issue here is not just the numbers, but the channel capacity. Parachains will typically have many low capacity channels and parachreads will want few channels with high capcity. There may be a limit on total capacity. This means that we need mechanisms for changing the capacity of existing channels. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.44195783138275146, "perplexity": 1264.7517704265135}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600401585213.82/warc/CC-MAIN-20200928041630-20200928071630-00236.warc.gz"} |
https://beta.briefideas.org/ideas/84ef3dbb77245cae8486c9a5cfd7d93b | By Neil Stacey
Membrane permeation is frequently modeled using a vector of relative permeabilities for each component that is permeated. However, no membrane material will have truly uniform permeability; instead, any particular membrane material exhibits variance in physical properties and permeability across its surface. In a very real sense, any single permeating surface can be thought of as a distribution of slightly different membranes as opposed to truly being a single membrane.
Multi-membrane permeation parameters can be fit to existing single-membrane characterization data to produce a more accurate permeation model for any particular membrane material. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8788664937019348, "perplexity": 1346.5482705605004}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296949694.55/warc/CC-MAIN-20230401001704-20230401031704-00604.warc.gz"} |
https://discuss.tlapl.us/msg00706.html | # Why is this an invalid TLA formula?
At the top of page 95 of *Specifying Systems: The TLA+ Language and Tools for Hardware and Software Engineers*, Lamport states that
$$\Box \Diamond ( \langle A \rangle_v \vee \langle B \rangle_v)$$
is not a valid TLA formula, even though its equivalent formulation
$$\Box \Diamond \langle A \vee B \rangle_v$$
*is* a valid TLA formula.
**Question:** Why is the first formula invalid and the second formula valid? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.22925686836242676, "perplexity": 2648.0050816459498}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623487612537.23/warc/CC-MAIN-20210614135913-20210614165913-00595.warc.gz"} |
https://www.gamedev.net/forums/topic/482618-messagebox-not-working-in-vc/ | Public Group
# MessageBox() Not working in vc++
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Hello all! I have just decided to make the leap from Dev-c++ to Visual C++ :) I have decided to start with some simple examples to get comfortable with the ide but I ran into a problem right away. In this example I just want a popup message box. Here is the code.
#include <windows.h>
int WINAPI WinMain(HINSTANCE instance, HINSTANCE previnstance, PSTR cmdline, int show)
{
MessageBox(NULL, "Message Box Test!", "Hello World!", MB_OK);
return (0);
}
I try to run it and it barks at me for the two text parameters. It says they have to of type LPCWSTR. I then changed it to TEXT("Message Box Test!"), and TEXT("Hello World!"). It now compiles fine now but I have another problem. The background color of the message box is white while the button that says ok is gray. How do I change the default color of this? Thank you!
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It should take on the standard system colors. The only way I know of to change it is by monkeying around under Display Properties->Appearance->Advanced. When you get a message box in other applications, does it have the same appearance?
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Quote:
Original post by FunkyjiveI try to run it and it barks at me for the two text parameters. It says they have to of type LPCWSTR. I then changed it to TEXT("Message Box Test!"), and TEXT("Hello World!"). It now compiles fine now but I have another problem. The background color of the message box is white while the button that says ok is gray. How do I change the default color of this?
Any chance of a screenshot? It sounds like this is a Windows appearance setting (Right click on the desktop, go to Properties, then the Appearance tab and look at options there).
If you want to change it from the system default, you'll have to create the dialog box yourself (Which is a lot more complicated).
And about the TEXT() thing, you can change your application's character set from Unicode to Multi Byte Character Set (Project -> Properties (Alt+F7) -> Configuration Properties -> General -> Character Set). That'll do away with the need for the TEXT() macros and LPCWSTR errors, which is probably a good thing if you're just starting with Windows code.
EDIT: Too slow [smile]
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Thank you for the reply. I went and changed the character set and the TEXT() problem is taken care of. As for the white background here is a small pic of the problem...
I tested the program under Dev-c++ and the same thing so you must be right on about the settings of windows as opposed to the programming. Im running under Vista : ( so Ill play around to figure it out. I guess I never noticed it before.
Thanks again!
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The easy fix for this, based on the information presented in the OP is to add an L to the beginning of the string, but outside the quotes, as in:
MessageBox(NULL, L"MessageBox Test", L"Test", MB_OK);
This way you don't need to change any project settings, display settings or use the TEXT() macro. Hope that helps.
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Quote:
Original post by u235The easy fix for this, based on the information presented in the OP is to add an L to the beginning of the string, but outside the quotes, as in:MessageBox(NULL, L"MessageBox Test", L"Test", MB_OK);This way you don't need to change any project settings, display settings or use the TEXT() macro. Hope that helps.
True, although if the OP is just starting with Win32 programming, it's simpler to use MBCS. If they still use unicode, then they'll either have to convert to/from MBCS and unicode or they'll have to make sure that everything uses unicode (E.g. file IO). Personally, I think it's easier to use MBCS - at least till you get the hang of Win32, particularly since a lot of tutorials online assume MBCS.
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You might also find this information handy - the article describes how to enable Vista/XP visual themes for your programs. Technically this should work already if you're compiling with VS2005 or later on the latest PSDK (although that may not be the case for the Express Edition of VC++, I don't honestly know).
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Quote:
Original post by FunkyjiveI try to run it and it barks at me for the two text parameters. It says they have to of type LPCWSTR. I then changed it to TEXT("Message Box Test!"), and TEXT("Hello World!")
This is because of the Character Set. If your character set is Unicode, then you must put a L before every string, if its is Multi-Byte you must not. LPCWSTR is a long pointer to a wide const string, a const wchat_t, which is a 2 byte long Unicode char. If you want to avoid using TEXT() or L before every string, go to the project properties, Configuration Properties, General, Character Set, and change to MultiByte. hth
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https://repository.uantwerpen.be/link/irua/99817 | Publication
Title
Transverse-momentum compensation in $\pi^{+}p$ interactions at 250 GeV/c
Author
Abstract
Compensation of transverse momentum is studied in pi+ p interactions at 250 GeV/c. Significant p(T)-transfer is found between c.m.s. hemispheres. With respect to the beam axis transverse momentum is compensated over the whole event, with respect to the sphericity axis mainly within one hemisphere. The highest p(T) in the event is mainly compensated by increased multiplicity. The QGSM and FRITIOF models qualitatively reproduce these effects, but important differences are observed.
Language
English
Source (journal)
Zeitschrift für Physik : C : particles and fields. - Berlin
Publication
Berlin : 1994
ISSN
0170-9739
Volume/pages
64:3(1994), p. 381-389
ISI
A1994PT49400003
UAntwerpen
Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address | {"extraction_info": {"found_math": true, "script_math_tex": 1, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7416026592254639, "perplexity": 7632.322535994808}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-51/segments/1512948583808.69/warc/CC-MAIN-20171216045655-20171216071655-00448.warc.gz"} |
https://stats.stackexchange.com/questions/166442/calculating-gradient-in-a-neural-probabilistic-language-model | # Calculating gradient in a neural probabilistic language model
I am trying to reproduce a neural probabilistic language model described by Bengia (without distributed softmax computation).
According to Bengio et al. "training is achieved by looking for model parameters that maximize the training corpus log-likelihood". However, I can't find any mentions regarding what is actually used as a target value.
When building a neural network for classifying handwritten digits from a MNIST dataset, we may use a matrix (or a vector) of normalized values that represent corresponding pixels' brightness levels as input X. And one-hot vector of 10 elements may be used to represent an output Y (with all elements set to 0 except one set to 1 which index represents a digit label itself). This model is clear.
In case of a neural probabilistic language model we use context words' indices as input. These indices are then transformed to a set of feature vectors using vocabulary. Eventually, after processing by a hidden layer and softmax function we get a list of probabilities for each word of a vocabulary. And here I stuck. In a description of a backward/update phase Bengio uses:
∂L/∂yj ← 1j==wt − pj
to calculate initial gradient, where pj is a probability of j-th word in a vocabulary. I can't comprehend this part. Where does "1" come from? Is it necessary? Can we use the same approach to represent a target probability vector as in case with MNIST?
I think the confusing part in the term $\frac{\partial L}{\partial y_j}=1_{j=w_t}-p_{j}$ is the indicator function $1_{j=w_{t}}$ which is defined as $1$ when $j=w_{t}$ and $0$ otherwise. Therefore, in order to minimize the loss you want to obtain predictions $p_{j}$ that are close to $1$ for the output unit corresponding to the correct word $w_{t}$ and values near $0$ for the other output units. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7983253598213196, "perplexity": 621.0746648478982}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656104240553.67/warc/CC-MAIN-20220703104037-20220703134037-00423.warc.gz"} |
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# What is the remainder, after division by 100, of 7^10 ?
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What is the remainder, after division by 100, of 7^10 ? [#permalink] 07 Oct 2011, 20:45
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What is the remainder, after division by 100, of 7^10 ?
(A) 1
(B) 7
(C) 43
(D) 49
(E) 70
[Reveal] Spoiler: OA
Last edited by Bunuel on 14 Dec 2012, 01:13, edited 2 times in total.
Renamed the topic and edited the question.
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Re: PS [#permalink] 07 Oct 2011, 22:29
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We have such a pattern
7
7*7=49
7*7*7=343
7*7*7*7=...1
7*7*7*7*7=7
So, the last number repeats every 5th time.
10/4 = 2, and remainder is 2.
we choose 7*7
it means that 7*7*7*7*7*7*7*7*7*7=.......49
We divide by 100, it means .....,49
where 49 is a remainder.
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Re: PS [#permalink] 09 Oct 2011, 05:02
kkalyan wrote:
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Help End Exam Review Section
What is the remainder, after division by 100, of $$7^{10}$$ ?
1
7
43
49
70
PLZ EXPLAIN THE TRICK IN SOLVING THIS TYPE REMAINDER PROBLEM
Using Binomial theorem, last two digits of an exponent can be found as
7^(10)=7^(2*5)=49^5=(-1+50)^5=(-1)^5+5*(-1)^4*50=-1+50(Just considered last 2-digit of the product)=49
Look for Karishma's blogs. You may find more.
Ans: "D"
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Re: PS: Remainder of 7^(10) divided by 100 [#permalink] 09 Oct 2011, 08:35
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kkalyan wrote:
What is the remainder, after division by 100, of $$7^{10}$$ ?
(A) 1
(B) 7
(C) 43
(D) 49
(E) 70
7^4 is 2401 .
So we can write 7^10 as ( 7^4 *7^4 * 7^2) divided by 100 ..
This would give us (1*1*49)/ 100 which would give remainder as 49.
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Re: PS: Remainder of 7^(10) divided by 100 [#permalink] 14 Dec 2012, 00:48
if we do not hav formular, how do I do?
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Re: PS: Remainder of 7^(10) divided by 100 [#permalink] 14 Dec 2012, 01:21
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thangvietnam wrote:
if we do not hav formular, how do I do?
What is the remainder, after division by 100, of 7^10 ?
(A) 1
(B) 7
(C) 43
(D) 49
(E) 70
The remainder when 7^10 is divided by 100 will be the last two digits of 7^10 (for example 123 divided by 100 yields the remainder of 23, 345 divided by 100 yields the remainder of 45).
$$7^{10}=(7^2)^5=49^5$$ --> the units digit of 49^5 will be 9 (the units digit of 9^even is 1 and the units digit of 9^odd is 9).
So, we have that $$7^{10}=49^5$$ has the units digit of 9, thus the units digit of the remainder must also be 9. Only answer D fits.
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 16 Dec 2012, 12:56
Hey Bunnel,
this rule is general ? like if XXXXXX9^even the unit digit of the remainder is always 1 and XXXXX9^odd the unit digit of the remainder is always 9 ??
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 16 Dec 2012, 22:39
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see wrote:
Hey Bunnel,
this rule is general ? like if XXXXXX9^even the unit digit of the remainder is always 1 and XXXXX9^odd the unit digit of the remainder is always 9 ??
The units digit of 9^even is 1 and the units digit of 9^odd is 9.
If the units digit of a number is 1, then the remainder when this number will be divided by 100 will have the units digit of 1, for example 231 divided by 100 gives the reminder of 31.
If the units digit of a number is 9, then the remainder when this number will be divided by 100 will have the units digit of 9, for example 239 divided by 100 gives the reminder of 39.
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 17 Dec 2012, 23:14
what if the answer choise has another value with units digit 9? how do we need to proceed in that case?
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 18 Dec 2012, 00:38
Ans:
7^10 can be written as 49^5 which can be written as (49^2)^2. 49 when divided by 100 it will give a remainder of (1)^2.49=49 answer (D).
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 04 Feb 2013, 03:11
7 ^1 has last digit is 7
7^2 has last digit is 9
3
1
the last digit of 7^10 must be 9
the remainder must has the same last digit
only D fits
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 17 Dec 2013, 05:59
priyamne wrote:
Ans:
7^10 can be written as 49^5 which can be written as (49^2)^2. 49 when divided by 100 it will give a remainder of (1)^2.49=49 answer (D).
49^5 is not (49^2)^2
Thanks
Cheers!
J
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 01 May 2014, 02:10
Amateur wrote:
what if the answer choise has another value with units digit 9? how do we need to proceed in that case?
Good question. Any clues Bunnuel
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 17 Sep 2014, 10:13
kkalyan wrote:
What is the remainder, after division by 100, of 7^10 ?
(A) 1
(B) 7
(C) 43
(D) 49
(E) 70
sol:
7=7
7^2=..9
7^3=..3
7^4=1
now 10/4= 2 i.e. second from top of the pattern...which is 9
since we are dividing the number by 100 last number will be reminder
check the answers....D is the only choice
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 02 Oct 2014, 01:17
jlgdr wrote:
priyamne wrote:
Ans:
7^10 can be written as 49^5 which can be written as (49^2)^2. 49 when divided by 100 it will give a remainder of (1)^2.49=49 answer (D).
49^5 is not (49^2)^2
Thanks
Cheers!
J
Agree... this approach is incorrect......... $$(49^2)^2 = 49^{(2*2)} = 49^4$$
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 02 Oct 2014, 01:19
himanshujovi wrote:
Amateur wrote:
what if the answer choise has another value with units digit 9? how do we need to proceed in that case?
Good question. Any clues Bunnuel
When the units digit is 9, the remainder has to be 49. Any other remainder ending with units digit 9 is not possible
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Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 10 May 2015, 00:53
Bunuel wrote:
thangvietnam wrote:
if we do not hav formular, how do I do?
What is the remainder, after division by 100, of 7^10 ?
(A) 1
(B) 7
(C) 43
(D) 49
(E) 70
The remainder when 7^10 is divided by 100 will be the last two digits of 7^10 (for example 123 divided by 100 yields the remainder of 23, 345 divided by 100 yields the remainder of 45).
$$7^{10}=(7^2)^5=49^5$$ --> the units digit of 49^5 will be 9 (the units digit of 9^even is 1 and the units digit of 9^odd is 9).
So, we have that $$7^{10}=49^5$$ has the units digit of 9, thus the units digit of the remainder must also be 9. Only answer D fits.
excellent. I can not say a word for this wonderful explanation. thank you Buuney
Re: What is the remainder, after division by 100, of 7^10 ? [#permalink] 10 May 2015, 00:53
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Display posts from previous: Sort by | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3910164535045624, "perplexity": 6091.4812538121005}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-07/segments/1454701157262.85/warc/CC-MAIN-20160205193917-00012-ip-10-236-182-209.ec2.internal.warc.gz"} |
https://testbook.com/question-answer/a-ball-is-falling-freely-from-a-height-of-20-m-the--605a4491ade410f8fc102c15 | # A ball is falling freely from a height of 20 m then the velocity of ball when it reaches the ground at 20 m is (assume the acceleration of gravity as 10 m/s2 )?
This question was previously asked in
DSSSB JE ME 2019 Official Paper Shift - 2 (Held on 06 Nov 2019)
View all DSSSB JE Papers >
1. 40 m/s
2. 30 m/s
3. 10 m/s
4. 20 m/s
## Answer (Detailed Solution Below)
Option 4 : 20 m/s
## Detailed Solution
Concept:
Kinetic energy (KE):
The energy possessed by a body by virtue of its motion is called kinetic energy.
$$KE = \frac{1}{2}m{v^2}$$
Where m = mass of the body and v = velocity of the body
Potential energy (PE):
The energy possessed by a body by virtue of its position or configuration is called potential energy.
$$PE = mgh$$
Where, m = mass of the body, g = acceleration due to gravity and h = height of the body
Conservation of energy:
• According to the conservation of energyenergy can’t be created or destroyedit can only transform from one form to another.
• The total energy of the system remains constant i.e. the sum of kinetic energy + potential energy remains constant.
• When a ball is falling freely then its initial potential energy will slowly get converted into kinetic energy. but the total energy will remain constant.
• Thus the potential energy will decrease and the kinetic energy will increase until the body reached the bottom
Calculation:
Given:
h = 20 m, g = 10 m/s2
$$v = \sqrt{2gh} = \sqrt{2\;\times10\;\times20} = 20\; m$$
∴ The velocity of ball when it reaches the ground is 20 m | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9080840349197388, "perplexity": 1009.118738523665}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964358953.29/warc/CC-MAIN-20211130050047-20211130080047-00609.warc.gz"} |
https://www.nature.com/articles/srep18030?fbclid=IwAR1oOzypwsGJPBhbIBapP9k-Hhh9P9l88rap73eHiM3BXxDCTeyCWYV9eew&error=cookies_not_supported&code=73093cea-344c-40f9-ba8a-8bc05698fdea | Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.
# Efficient Structure Resonance Energy Transfer from Microwaves to Confined Acoustic Vibrations in Viruses
## Abstract
Virus is known to resonate in the confined-acoustic dipolar mode with microwave of the same frequency. However this effect was not considered in previous virus-microwave interaction studies and microwave-based virus epidemic prevention. Here we show that this structure-resonant energy transfer effect from microwaves to virus can be efficient enough so that airborne virus was inactivated with reasonable microwave power density safe for the open public. We demonstrate this effect by measuring the residual viral infectivity of influenza A virus after illuminating microwaves with different frequencies and powers. We also established a theoretical model to estimate the microwaves power threshold for virus inactivation and good agreement with experiments was obtained. Such structure-resonant energy transfer induced inactivation is mainly through physically fracturing the virus structure, which was confirmed by real-time reverse transcription polymerase chain reaction. These results provide a pathway toward establishing a new epidemic prevention strategy in open public for airborne virus.
## Introduction
In the past few decades, tremendous efforts have been made to kill airborne viruses such as severe acute respiratory syndrome (SARS) coronavirus or influenza viruses, which have caused catastrophic illness worldwide. Current airborne virus epidemic prevention to be used in public space includes strong chemical inactivation, UV irradiation and microwave thermal heating. All these methods affect the open public. In 1980s, Robach et al.1 and Cerf 2 demonstrated that ultrasonic energy can be absorbed by viruses. In 2000, Babincová et al.3 hypothesized that viruses can be inactivated by generating the corresponding resonance ultrasound vibrations of viruses, which is in the GHz region. Based on this hypothesis, several groups started investigating the vibrational modes of viruses in this frequency range4,5,6,7. Recently we demonstrated that dipolar mode of the confined acoustic vibrations (CAVs) inside viruses can be resonantly excited by microwaves of the same frequency with a resonant microwave absorption effect8. The observed microwave resonance absorption phenomenon indicates a possible structure-resonant energy transfer (SRET) effect from electromagnetic waves (EM waves) to CAVs of viruses. Theoretically this SRET process is an efficient way to excite the vibrational mode of the whole virus structure due to a 100% energy conversion of a photon into a phonon of the same frequency, but the overall SRET efficiency is also related to the mechanical properties of the surrounding environment9, which influences the quality factor of the oscillator (virus). A study on the SRET efficiency to inactive virus is thus highly desired and it will determine if this SRET phenomenon provides a solution to inactivate airborne viruses in open public for epidemic prevention.
In this article, we show that SRET from microwave to virus can be efficient enough so that airborne virus was inactivated with reasonable microwave power density safe for the open public. To investigate the SRET efficiency from EM waves to CAVs in viruses, we first developed a theoretical model to describe the relation between the induced stress and the field magnitude of the illuminating microwave. Since the viruses could be inactivated when the induced stress fractures the structure of viruses, we propose to explore the SRET efficiency from microwaves to viruses through measuring the virus inactivation threshold. Based on the proposed model, we studied the inactivation ratio of influenza A (H3N2) virus at dipolar-mode-resonance and off-resonance microwave frequencies as well as with different microwave powers. Plaque assay10 was then applied to calculate the titer of virus samples before and after the microwave illumination. Our results indicate efficient SRET from microwave to viruses, which resulted in higher inactivation ratio of viruses at the dipolar resonant frequency. At the resonant frequency, the microwave power density threshold for H3N2 inactivation was found to be below the IEEE safety standard, also agreeing well with our developed theoretical model. The real-time reverse transcription polymerase chain reaction (real-time RT-PCR) method11 was further performed to confirm that the main inactivation mechanism is through physically fracturing the viruses while the RNA genome was not degraded by the microwave illumination, supporting the fact that our studied SRET mechanism is fundamentally different from the microwave thermal heating effect. These results provide a pathway toward establishing a new epidemic prevention strategy in open public for airborne virus.
## Modelling
From the transmission electron microscope images, people knew that the virions of influenza viruses are basically spherical balls packing genomes inside. Since the protein and genome have similar mechanical properties8, for the estimation of dipolar vibration frequencies, we treat the virion as a homogenous sphere.
### Dipolar Mode of a Homogeneous Sphere
Due to the spatial confinement, not only electronic but also acoustic energy quantization has been observed in low dimensional systems such as quantum dots and nano-wires. In 1882, Lamb studied the torsional (TOR) and spheroidal (SPH) modes of a homogeneous free sphere by considering the stress-free boundary condition on the surface12. Among these modes, the SPH mode with allows dipolar coupling13 and the corresponding eigenvalue equation can be expressed as14,15:
where , is the spherical Bessel function of the first kind, ω is the angular frequency of the vibrational mode, R is the radius of the nano-sphere, cland ctare longitudinal and transverse sound velocities respectively. A comparison between the commonly observed breathing mode and the dipolar mode can be found in Supplementary online. the Since the dipolar mode of a nano-sphere cannot be detected by the light scattering experiments16, it was not observed until a previous study of the resonant excitation of dipolar mode through THz wave or microwave excitations17,18 when the core and shell of the nano-sphere have permanent charge separation. Once the resonantly oscillating electric field was applied to the nano-sphere, opposite displacement between core and shell was generated, thus excited the dipolar mode vibrations. Compared with the breathing () and quadrapolar () modes, dipolar mode () is the only SPH mode to directly interact with the EM waves whose wavelength is much longer than the particle’s size. Due to the permanent charge separation nature of viruses, in 2009, dipolar coupling with CAVs is confirmed to be the mechanisms responsible for microwave resonant absorption in viruses by treating spherical viruses as free homogeneous nanoparticles8,9.
Figure 1 shows the simulated displacement field of the dipolar mode (calculated by the finite element method, COMSOL Multiphysics, COMSOL, Inc.) of a homogeneous sphere (mass density and viscoelastic properties are constant throughout the sphere). We define the relative displacement direction of the dipolar mode as the z-direction, which will also be the field direction of the applied EM waves discussed in the next section. By plotting the displacement field of the x-z plane (y = 0) of the sphere, the opposite displacement between the core and shell regions can be clearly observed in Fig. 1(b). Meanwhile Fig. 1 (c) shows the side view of the distortion of the x-y plane of the sphere at different z locations, which concludes that the maximum distortion occurs on the equatorial plane (z = 0) of the sphere. Figure 1(d) shows the top view of the displacement field of the equatorial plane (z = 0). It is interesting to find out that the magnitude of averaged positive displacement (inner region) is 1.27 times the magnitude of the averaged negative displacement (outer region), while positive and negative displacements occupy 42% and 58% area, respectively. Furthermore one can find that the maximum magnitude of the displacement, occurring either at the very center or the outer surface of the equatorial plane, is approximately twice of the averaged magnitude of the displacement.
### A Damped Mass-Spring Model
In this work, microwaves were applied to excite the dipolar resonance of the whole virus structure. By exciting the dipolar mode of the nanosphere, core and shell with opposite charge distributions would move in opposite directions and will resonate like a damped mass-spring system17. Our following analysis is similar to the Drude-Lorentz model describing the light-atom interaction, which connects a damped mass-spring system to the quantum-mechanical electronic resonant transitions. In the damped mass-spring system by adopting the reduced mass (m*) of core and shell in the analysis, the relative motion of the displacement can be shown in the following equation:
where z is the relative displacement between the core and shell; b is the damping coefficient, which is related to the surrounding environment; k is the effective spring constant of this system. By assuming z(t) proportional to exp(iωt), one can solve the complex angular frequency of the resonator as:
Therefore the decay rate of the oscillation equals to the imaginary part of the frequency (b/2m*), which corresponds to ω0/2Q19:
The intrinsic resonance angular frequency (ω0) of this system is (k/)0.5. Q is the quality factor of the resonator. From equation (4), stronger damping increased the energy transfer between the resonator and its surrounding environment, which decreases the confinement of the vibration and leads the lower Q. Now we approximate that a spherical virus is like a homogeneous sphere but with opposite and equal charges in the core and shell regions. When the oscillating electric field (cos) of microwaves is applied to the system, forced displacements would be induced with the same frequency as the applied microwaves. The equation of motion now needs to include the force induced by the applied electric field (qE), where q is the total amount of charge distributed in the core and shell region of a virus:
We describe the forced displacement as , where A is the amplitude of the forced displacement and is the phase delay between the displacement and the applied electric field. By solving the particular solution of this differential equation, one can obtain the phase delay and the amplitude of the forced oscillating displacement as
and
The instantaneous power absorption of this system is then described as the following equation, where v is the velocity of the oscillating motion17:
By integrating over one full cycle, one can obtain the average power absorption from the system:
Then the absorption cross-section of the virus can be obtained by setting the input power flux as with20
where is the relative permittivity in the system and c is the speed of light in vacuum.
### Threshold to Fracture a Virus
With oscillating dipolar vibration to inactivate a virus, the most possible mechanism is to fracture the most outer surface of the equatorial plane (z = 0) due to the location of the maximum distortions, as illustrated in Fig. 1 (c,d). For influenza viruses, this corresponds to the lipid membrane of the envelope. To estimate the maximum induced stress on the equatorial plane, we divide the maximum induced force by the area of the shell region (defined by the moving direction in the approximate model) on the equatorial plane. Following above discussion, we found that the maximum induced stress is twice the average value and the shell region covers 58% of the equatorial plane:
If the required stress threshold to fracture a virus can be obtained, the threshold electric field magnitude of the incident microwaves can also be obtained by using:
Figure 2 shows the threshold magnitude of the incident electric field at different frequencies with different Q based on equation (12) with a fixed threshold value. One can observe that the minimum of the threshold electric field magnitude occurs when the applied frequency is closed to the intrinsic resonant frequency. Moreover cavity quality factor Q plays a major role. By changing the pH value of the solution, charge status of viral surface can be modulated, which affects the Q of the vibration. For example, previous studies indicated that the cavity Q of spherical viruses ranges between 2–10 by raising the pH value of the solution from 5.4 to 7.48. With increased Q, more energy can be confined inside the resonator, which leads to much lower microwave field threshold magnitude at the resonant frequency.
To experimentally study the efficiency of the SRET from microwaves to CAVs of spherical viruses, influenza A virus subtype H3N2 was used. H3N2 is a subtype of influenza A virus that causes flu. Such viruses can infect birds and mammals and are increasingly abundant in seasonal influenza, which kills an estimated 6309 people in the United States each year, including pneumonia and influenza causes21. Based on previous studies, the averaged mass and the diameter of the H3N2 virus are 161 MDa22 and 100 nm23. Here we approximate the structure of the virus as a nanosphere with a core-shell structure of opposite charge distribution. The shell (90% of the total mass) contains lipid, neuraminidase (NA), hemagglutinin (HA) and M-protein. The core (10% of the total mass) includes RNA and RNP. The reduced mass (m*) of virus is thus 14.5 MDa. From the literature24, force with 400 pN applied on the AFM tip can fracture the lipid envelope. Since the radius of the tip was 30 nm24, the threshold stress to fracture the shell was 0.141 MPa (). In order to calculate the threshold magnitude of the electric field to fracture H3N2 virus following equation (12), some important parameters such as q, Q and ω0 of the studied H3N2 virus has to be obtained by measuring the microwave absorption spectrum of viruses.
As shown in Fig. 3(a) we covered the structure of the coplanar waveguide (CPW) by the microfluidic channel with a 1.25 mm-long sensing zone (L) in order to measure the microwave absorption spectrum of viruses. This microwave microfluidic channel can provide a microwave bandwidth over 40 GHz. The measured results were summarized in Fig. 3(b). As the figure shows, the power absorption ratio (α) by the virus at the resonant frequency (8.2 GHz) was 21% and the Q was only 1.95 by measuring the full width at half maximum of the spectrum. Since the density of viruses (N) in the solution was 7.51014 m−3, experimental absorption cross section of the virus at the resonant frequency can be calculated by the equation below:
From equation (10), the theoretical absorption cross-section of the virus at the resonant frequency is:
By setting of the PBS at 8.2 GHz as 67.1325, = can be obtained by comparing equation (13) and equation (14).
So far, all parameters for estimating electric field threshold in equation (12) are obtained. By substituting threshold Pstress = 0.141 MPa, = , m* = 14.5 MDa, Q = 1.95 and ω0 = 2π × 8.22 GHz into equation (12), threshold magnitude of electric field to fracture virus at different frequencies of microwave can be calculated. The result is shown in Fig. 3(c). In order to compare with the following inactivation experiments, our estimated threshold magnitude of electric field at 6, 8 and 10 GHz are 103.3, 86.9 and 137.1 V/m, respectively. The minimum threshold occurs close to 8 GHz due to resonance and sufficient internal stress to fracture virus can be expected to be more efficiently generated by weaker electric field.
Based on the IEEE Microwave Safety Standard, the spatial averaged value of the power density in air in open public space shall not exceed the equivalent power density of 100(f/3)1/5 W/m2 at frequencies between 3 and 96 GHz (f is in GHz)26. This corresponds to 115 W/m2 at 6 GHz, 122 W/m2 at 8 GHz and 127 W/m2 at 10 GHz for averaged values of the power densities in air. Assuming all the microwave power in air 100% transmitted into a specimen and by taking the dielectric constant of water 71.92 (6 GHz), 67.4 (8 GHz) and 63.04 (10 GHz)25 for calculation, this safety standard then corresponds to the average electric field magnitude of 101 V/m (6 GHz), 106 V/m (8 GHz), 110 V/m (10 GHz) inside the water-based specimens. It is interesting to notice that the required threshold electric field magnitudes at the resonant frequency (86.9 V/m) to fracture H3N2 viruses as shown in Fig. 3(c) are within the IEEE Microwave Safety Standard (106 V/m), indicating high SRET efficiency, even though the quality factor of the H3N2 virus is low.
## Results
### Virus Inactivation Experiments – Frequency dependency
To investigate the resonant effect, we first measured the residual viral infectivity of influenza A virus after illuminating microwave of different frequencies. As shown in Fig. 4(a), viral samples were placed below the horn antenna. The sponge under the sample was used to decrease the reflection of the microwave. To check the inactivation ratio, illuminated viruses were then analyzed by plaque assay to measure the residual infectivity of viruses. We compared the titer of illuminated viruses (Ntest) and the titer of unilluminated control sets (Ncontrol) to calculate the inactivation ratio (1 − Ntest/Ncontrol) at different frequencies between 6–12 GHz.
Based on Fig. 3(c), the field intensity threshold for inactivating H3N2 virus ranges between 86.9–236.3 V/m, which corresponds to 82.3–564 W/m2, for microwaves between 6 and 12 GHz. Since the aperture size of our horn antenna was 9.8 cm × 7.1 cm. The required threshold power input ranges from 0.57 W to 3.92 W for 6–12 GHz microwaves. We thus first applied 6.3 W (38 dBm) fixed microwave power, which is higher than all the threshold power input, into the horn antenna for the frequency dependency studies. After considering the transmission coefficient of our horn antenna, this experimental condition corresponded to 765 – 882 W/m2 average illuminated power density on the sample surface, corresponding to the field intensity inside the specimen of 260–296 V/m respectively. For 8–8.4 GHz microwave at the resonant frequency, the average illuminated power density was about 810 W/m2, equivalent to 273 V/m effective field intensity inside the sample. We thus expect to observe the inactivation effect throughout the studied spectral range. As been summarized in Fig. 4(b), a frequency dependent inactivation ratio can be observed in our experiments, with a peak located at the resonant frequency of the dipolar mode while higher than 50% inactivation ratio can be observed throughout the studied frequency range. At 8.4 GHz, the measured titer count was zero, indicating 100% inactivation ratio, which means that the remaining active viral concentration was smaller than the system sensitivity of 10 pfu/mL. This result indicates at least a three-order of magnitudes attenuation on the virus titer, when the microwave frequency was tuned to the dipolar mode resonant frequency with the electric field intensity 3 times higher than the threshold. The illuminated average power density was roughly 6.7 times higher than the IEEE safety standard for the 8–8.4 GHz cases. It is important to notice that the power density is proportional to the square of the field intensity.
### Virus Inactivation Experiments – Power density dependency
To further investigate the efficiency of this SRET effect from microwave to virus and the threshold effect, we further measured the inactivation ratio of H3N2 virus with different power densities at the resonant frequency ~8 GHz of the confined acoustic dipolar mode. Our theoretical model predicted an inactivation threshold field intensity of 86.9 V/m, corresponding to an average microwave power density of 82.3 W/m2 in specimen. Since we assume all power can transmit from air to specimen, power density in air is also 82.3 W/m2, which is 1.48 times lower than the IEEE safety standard. Figure 5 (b) summarized the measured inactivation ratio for 4 different average microwave power densities of 820, 320, 82 and 51 W/m2 in air, corresponding to an effective field intensity inside samples of 274, 171, 87 and 68 V/m, respectively. It is noted that the experiment with 82 W/m2 in air was performed in a different experimental setup, as shown in Fig. 5(a). A significant threshold effect can be observed when the effective field intensity inside samples started to be on the order of or exceed the estimated threshold. A 38% inactivation ratio can be observed with a field intensity of 87 V/m, while the inactivation ratio dropped drastically to only negligible 6% with a slightly lower 68 V/m field intensity. With a 3 times higher field intensity than the threshold, the inactivation ratio saturated at a 100% value.
## Discussions
Compared with the simple theoretical model for threshold estimation as summarized in Fig. 3(c), our result agrees qualitatively and surprisingly quantitatively. First, in our experiments, we observed a strong resonant effect on the virus inactivation ratio at the dipolar oscillation frequency of 8.4 GHz, thus indicating that the observed virus inactivation after microwave illumination was due to the proposed SRET from microwave to virus through dipolar coupling. Second, at the resonant frequency, we do observe H3N2 virus inactivation by illuminating 82 W/m2 (lower than the IEEE safety standard in public space) 8 GHz microwaves on our viral solution, corresponding to an average 87 V/m electric field intensity inside the solution, confirming that our proposed simple model to estimate the field threshold (86.9 V/m) to structurally fracture the virus is quantitatively correct, especially combining the observed threshold effect as discussed above. With a low resonator quality factor (around and less than 2 for H3N2), we also observed virus inactivation in off-resonant frequencies (6-12GHz), following a trend predicted with our model. However for off-resonant frequencies, the simple harmonic oscillator model seems to always estimate a lower threshold in the Stoke-side (lower-frequency-side) of the resonant frequency than the anti-Stoke-side (high-frequency-side). For example, at DC (0 frequency) it still predicts a relatively low threshold field magnitude to fracture the virus. This is different from our observation. We observe that the anti-Stoke-side is with a better inactivation ratio than the Stoke-side and the source for disagreement should be the over-simplification of the adopted model.
Our result regarding the efficient SRET to inactivate virus with a low microwave power has a profound meaning. As we introduced, in the past few decades, tremendous efforts have been made to kill airborne viruses such as SARS or influenza A, which have caused catastrophic illness worldwide. Active airborne viruses are always transported inside tiny water droplets, thus similar to our experimental condition. A strategy for airborne virus epidemic prevention in open public is thus highly desired. Our finding represents the first possible mechanism to inactivate airborne viruses without affecting the open public, since the required microwave power could be within the IEEE safety standard. Comparing this work with traditional microwave thermal inactivation, previous works27,28 used a microwaves oven with more than 100 W to heat the phage suspension. The inactivation ratio could reach almost 100% by increasing the temperature of the phage suspension to 80 °C. In our case, 100% inactivation were achieved with 6.3 W (38 dBm) as the input power into the horn antenna at 8.4 GHz. A power reduction by more than a factor of 15 is achieved. It is however not possible to directly compare the irradiating power density, since the irradiating area was not provided in previous literatures. Nevertheless our work still shows sharp contrast to current methodologies, including strong chemical inactivation, UV irradiation and microwave thermal heating with 100 W microwave power27,28, which are not safe for the open public.
A previous study29 has shown that to inactivate human H3N2 viruses through thermal heating, the temperature need to be higher than 55 °C. Compared with the 82 W/m2 radiated microwave power density (0.63 W required power input) in our resonant inactivation case, the current microwave thermal heating method to inactivate virus usually requires more than 100 W microwave power at 2.45 GHz27,28, which is way beyond the safety standard, in order to raise the sample temperature to be higher than 60 °C for protein denature. It is known that the microwave thermal heating has a weak frequency dependency between 6–12 GHz and this is not the case for our frequency dependent result as shown in Fig. 4(b). To confirm that our observation is not due to the microwave thermal heating effect, we had monitored the sample temperature change during the microwave illumination experiments with a radiated power density of 486 W/m2 at a frequency of 6 GHz by using an infrared thermal imaging camera with a temperature accuracy of 0.05 °C (CHCT, P384-20). The temperature rise after 15 minutes radiation was 7 °C, from 27.5 °C up to 34.5 °C. We thus exclude the possible contribution of microwave thermal heating effect to inactivation H3N2 viruses under our experimental condition.
To double-confirm our proposed mechanism that the inactivation was through physically fracturing the structure of viruses, we established a fractured virus model by freezing the virus samples with liquid nitrogen and thawed immediately and repeated several times. We then preformed real-time RT-PCR (Reverse Transcription Polymerase Chain Reaction) experiment for RNA amplification in order to compare the results after microwave illumination with the established fractured-virus model. Without protein denature, the established fractured-virus model allowed the viral RNA content to be extracted after fracturing. We then performed the RT-PCR experiments to amplify the extracted viral RNA after fracturing either through the frozen fracturing model or after microwave resonant irradiation. Figure 6(a) summarized our results. The applied average microwave power density was 320 W/m2, the microwave frequency was tuned to the dipolar mode resonant frequency of 8.35 GHz and the illumination time was 15 minutes. To avoid possible existing viral RNA in solution before the microwave illumination, we pretreated the virus samples by adding RNase to degrade the existing RNA outside the viral particles. As can be revealed in Fig. 6(a), the control fractured-virus model (shown as “control”) showed the same RNA amplification trend with excellent quantitative agreement with the RNase-pretreated samples after microwave resonant illumination (shown as “pretreat”). Obvious increase of copies in PCR can be observed after cycle 15. We have also performed two post-treat groups to double confirm the effect of the RNase. For post-treat groups, RNase was added right after the microwave resonant illumination. Even if the virus particles were fractured, the released RNA would be degraded by RNase, we did not expect to detect the viral RNA. As been also confirmed by our RT-PCR experiment as shown in Fig. 6(a), we were not able to detect the signal of RNA for the post-treat groups even after 45 cycles.
Since all the RNAs outside the virus surface in the solution were eliminated before the microwave illumination, for the pretreat samples the only way to detect the RNA signal after the illumination was to fracture the virus so that the RNA can be released. This result was also in good agreement on the amount of amplified RNA in the control cases. These facts confirmed that the inactivation of viruses by illuminating microwaves at the dipolar mode resonant frequency was through physically fracturing the lipid-envelope of the influenza virus without denaturing the viral RNA.
To show that the investigated SRET effect can be applied to deactivate viruses other than H3N2, we have also performed the real-time RT-PCR experiment on H1N1 virus. The result was shown in Fig. 6(b). The applied microwave frequency was 7 GHz, while the applied average microwave power density was 308 W/m2, corresponding to an effective electric field of 167 V/m inside the specimens. The rest of the experimental conditions were the same as that of Fig. 6(a). Similar results can be observed, indicating that the same SRET induced inactivation effect can also occurs in virus other than H3N2.
In summary, we investigated the structure resonance energy transfer from microwave to CAVs of H3N2 virus in water-based solution. The efficiency of such energy transfer was investigated through exploring the virus inactivation ratio. Based on the proposed damped mass-spring model and the experimentally measured microwave absorption cross-section of a single virus, threshold magnitude of electric field to fracture viruses at different illuminated frequencies can be estimated. After the illumination by the microwave, the plaque assay experiment indicated that the inactivation ratio reaches its maximum at the resonant frequency of the dipolar resonance. The real-time RT-PCR experiment double confirmed that the main inactivation mechanism was through physically fracturing viruses without degrading viral RNA genome. This work not only theoretically and experimentally demonstrates a new energy transfer mechanism between EM waves and viruses, but also indicates an efficient SRET effect. Our results have important implications for the interaction between microwaves and biological tissues, which is a highly concerned public issue. With an observed inactivation threshold with a microwave power density within the IEEE safety standard, the demonstrated SRET mechanism also provides a pathway toward establishing a new epidemic prevention strategy in open public for airborne viruses.
## Methods
### H3N2/H1N1 Sample Preparation
To prepare the H3N2 and H1N1 virus samples, Madin-Darby canine kidney (MDCK) cells were confluent grown in 75 cm2 flasks, inoculated by influenza A virus H3N2 (H090103, NTU Hospital) or H1N1 (NTUH135/2009, NTU Hospital) with multiplicity of infection (MOI) of 0.01 and incubated at 37 °C in a 5% CO2 incubator for 2–3 days. When the cytopathic effect (CPE) of the inoculated cells reached to 3 + (75%), we harvested the viral supernatant. The viruses were aliquot and stored at −80 °C for further use.
### Microwave Absorption Spectrum Measurement
The microwave absorption spectrum measurement was performed by combining the coplanar waveguide (CPW) circuit with a microfluidic channel. As shown in Fig. 3(a), we covered the structure of the CPW by the microfluidic channel with a 1.25 mm-long sensing zone (L). The gap between the signal electrode and the ground electrode of the CPW was 25 μm. In order to decrease microwave loss on the electrodes, the gold layer thickness of the electrode was 1.2 μm. On the surface of electrodes, we grew a thermal isolator layer of silicon dioxide on the sensing zone by Plasma Enhanced Chemical Vapor Deposition (PECVD) to lower the temperature rise of fluids due to microwave dielectric heating30. We then used a network analyzer (Anritsu, MS2028C) as the source to measure the absorption spectrum of H3N2 viruses from 6 GHz to 14 GHz. The virus particle density in the solution was 7.5 × 1014 m−3. The spectrum of the solution without viruses was first measured as a reference; solution with viruses was later measured. By removing the solution background, the microwave absorption spectrum of H3N2 viruses in solution was thus obtained (Fig. 3(b)) following a procedure similar to ref. 8.
### Microwave Illumination Measurement
In our experiments, we used two different microwave sources, depending on the utilized microwave power: a network analyzer (Anritsu, MS2028C) or an Yttrium iron garnet (YIG) oscillator. Then the microwave signal was amplified by a power amplifier (QPJ-06183640) and radiated from the horn antenna (ELECTRO-METRICS, EM-6969). The aperture size of the antenna was 9.8 cm × 7.1 cm. To avoid damage on oscillator and amplifier caused by back reflection, we added an isolator and a directional coupler. All the microwave systems were put in a P2 class flow hood. The antenna was directed toward the bottom (Fig. 4(a)) or the side (Fig. 5(a)) of flow hood and the microwave was normally incident on either microscope slides (Fig. 4(a)) or acrylic cuvettes (Fig. 5(a)) at a distance of 5 cm below the exit of horn antenna. To avoid large reflection from the metal hood surface, the microscope slide or cuvette was put in a plastic dish supported by a broad band pyramidal absorber. For each measurement, the viral solution (7.5 × 1014 m−3 particle density) under illumination was drop on the slide and covered with a cover glass or was contained inside the cuvettes. Under such an experimental geometry, we illuminated viruses for 15 minutes at various microwave frequencies or at various microwave powers. After illumination, we used buffer to wash-down and collect the viruses, which introduced a 10-fold dilution of virus concentration. Then the illuminated viral solutions, together with the control sets were sent for plaque assay.
### Quantitative Plaque Assay Analysis
To measure the activity of viruses, we employed a quantitative plaque assay. The MDCK cells used for plaque assay were grown in 6 wells plates by adding 3 mL of cells (2 × 105/mL) to individual well. After confluent growth of MDCK cells in plates, the cells were successively washed with phosphate buffer saline (pH 7.2) and Eagles’ MEM with 2 μg/mL TPCK trypsin. After washed, 100 μL of the ten-fold serial dilution of viruses were added into each well. For better virus adsorption, the inoculated cells were incubated at 37 °C in a 5% CO2 incubator for one hour. After then, the virus inoculums were removed and the Eagles’ minimal essential medium with 2 μg/mL TPCK trypsin and 0.5% agarose was added. After the gel formation, the plates were put in a 5% CO2 incubator for at least 42–48 hrs. After incubation, the plates were fixed with 10% formalin for 1 hour. After pour off agarose, the fixed cells were stained with crystal violet for 15 min and washed with tap water. Below certain virus concentration, the plaques wouldn’t overlap each other seriously and can be counted unambiguously. Considering the corresponding dilution factor, the plaque forming unit per mL (pfu/mL) of the original virus can thus be quantified. The titer measurement will be performed three times on the same sample to reduce quantization error. Quantified by the plaque assay, the concentration of active viruses in our prepared viral solutions was around 107/ml for H1N1 and H3N2.
### Real-time PCR Analysis
The sample RNA was extracted and amplified by the RT and quantitative real-time PCR (Primerdesign Precision OneStep™ qRT-PCR Mastermix) with primer AMF (sequence: 5′-GAGTCTTCTAACCGAGGTCGAAACGTA-3′), primer flu-AR (sequence: 5′-CAAAGCGTCTACGCTGCAGTCC-3′) and flu A (5′-FAM-tttgtgtttacgctcaccgt-TAMRA-3′) probe. For control group, RNase was added for 10 minutes digestion and stopped with RNase inhibitor. Then viruses were fractured artificially by freeze-thaw treatment. We thus were able to observe that the RNA signal of virus rose after 15 cycles of the amplification. For pre-treated groups, the RNase treatment were done and stopped before 8 GHz microwave illumination in order to make sure that RNA outside the viral envelope was eliminated in the first place. For the post-treat groups, RNase was added right after the illumination. If the virus particles were fractured, the released RNA would be degraded by RNase.
How to cite this article: Yang, S.-C. et al. Efficient Structure Resonance Energy Transfer from Microwaves to Confined Acoustic Vibrations in Viruses. Sci. Rep. 5, 18030; doi: 10.1038/srep18030 (2015).
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## Acknowledgements
This project was sponsored by the Ministry of Science and Technology of Taiwan under MOST 103-2112 -M-002-016-MY3.
## Author information
Authors
### Contributions
C.K.S. initiated the concept and conducted the experiments. S.C.Y., H.C.L. and T.M.L. performed the experiments. J.T.L., W.T.H., Y.R.H., Y.C.T., C.L.K. and S.Y.C. participated the discussion. S.C.Y. and C.K.S. wrote this manuscript and analyzed all data.
## Ethics declarations
### Competing interests
The authors declare no competing financial interests.
## Rights and permissions
Reprints and Permissions
Yang, SC., Lin, HC., Liu, TM. et al. Efficient Structure Resonance Energy Transfer from Microwaves to Confined Acoustic Vibrations in Viruses. Sci Rep 5, 18030 (2016). https://doi.org/10.1038/srep18030
• Accepted:
• Published:
• DOI: https://doi.org/10.1038/srep18030
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Scientific Reports (2016) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8585049510002136, "perplexity": 2747.163822921554}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656103620968.33/warc/CC-MAIN-20220629024217-20220629054217-00638.warc.gz"} |
http://mathhelpforum.com/calculus/124855-more-integration-print.html | # more integration!
• January 21st 2010, 05:31 PM
littlesohi
more integration!
1. $\int x^2sin2x dx$
2. $\int (x+3)/(x+1)$
• January 21st 2010, 05:33 PM
Jhevon
Quote:
Originally Posted by littlesohi
1. $\int x^2sin2x dx$
Hint: integration by parts: $u = x^2, ~dv = \sin 2x dx$ (you will have to do integration by parts twice.
Quote:
2. $\int (x+3)/(x+1)$
Hint: Note that this is $\int \frac {x + 1 + 2}{x + 1}~dx = \int \left( 1 + \frac 2{x + 1} \right)~dx$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 6, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.896185040473938, "perplexity": 7416.145173127054}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-10/segments/1394010929218/warc/CC-MAIN-20140305091529-00073-ip-10-183-142-35.ec2.internal.warc.gz"} |
https://cs.stackexchange.com/questions/115744/what-will-be-the-pictorial-diagram-of-this-transition-table | # What will be the pictorial diagram of this transition table?
I was doing my homework and I am confused on what I'm doing, it can't be that straightforward. I'm making a mistake somewhere. I tried looking for practice problems but they don't cover my issue either, I'm still confused. What will be the pictorial diagram for the following transition table?
You just create a super simple Graphviz document encoding the information:
$cat foo.gv digraph { q0 -> q0 [label = "input: a\noutput: 0"]; q0 -> q2 [label = "input: b\noutput: 0"]; q1 -> q1 [label = "input: a\noutput: 1"]; q1 -> q0 [label = "input: b\noutput: 1"]; q2 -> q2 [label = "input: a\noutput: 1"]; q2 -> q1 [label = "input: b\noutput: 1"]; }$ _
Process it:
$$dot foo.gv -T png -o foo.png$$ echo $$? 0$$ _
Profit!
• Hey is this the moore diagram? – Ammar Oct 12 '19 at 9:25
• @Ammar, hey, so you know for the future, we are encouraging gender-neutral writing: see meta.stackexchange.com/q/334900/160917, meta.stackexchange.com/q/335031/160917. I hope you'll consider thinking about how you can follow those guidelines! – D.W. Oct 12 '19 at 17:25
• I'm sorry but is that a warning? I didn't even know I'm violating any guidelines and there isn't even any mention of a gender pronoun like he/she so how come? – Ammar Oct 13 '19 at 6:43
• This comment now marked with "this comment was edited 1 time" wasn't gender neutral in its original form, and so was flagged for moderation attention. – 108880 Oct 13 '19 at 7:31
• My apologies I didn't know that I wrote something like that – Ammar Oct 13 '19 at 16:30 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 2, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5900831818580627, "perplexity": 1170.5497932079218}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655887319.41/warc/CC-MAIN-20200705090648-20200705120648-00207.warc.gz"} |
https://en.wikipedia.org/wiki/Steven_Zucker | # Steven Zucker
Steven Zucker
Nationality American
Alma materPrinceton University
Scientific career
FieldsMathematics
InstitutionsJohns Hopkins University
Zucker completed his Ph.D. in 1974 at Princeton University under the supervision of Spencer Bloch. His work with David A. Cox led to an algorithm for determining if a given set of sections provides a basis (up to torsion) for the Mordell–Weil group of an elliptic surface ${\displaystyle E\to S}$, where ${\displaystyle S}$ is isomorphic to the projective line. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 2, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8007169961929321, "perplexity": 383.9957402114998}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-47/segments/1542039746112.65/warc/CC-MAIN-20181119212731-20181119233907-00044.warc.gz"} |
http://hal.in2p3.fr/in2p3-00714892 | # Holographic bulk viscosity: GPR vs EO
4 APC - THEORIE
APC - UMR 7164 - AstroParticule et Cosmologie, Institut für theoretische Physik
Abstract : Recently Eling and Oz (EO) proposed a formula for the holographic bulk viscosity, in arXiv:1103.1657, derived from the null horizon focusing equation. This formula seems different from that obtained earlier by Gubser, Pufu and Rocha (GPR) in arXiv:0806.0407 calculated from the IR limit of the two-point function of the trace of the stress tensor. The two were shown to agree only for some simple scaling cases. We point out that the two formulae agree in two non-trivial holographic theories describing RG flows. The first is the strongly coupled $\mathbb{N}$=2$^*$ gauge theory plasma. The second is the semi-phenomenological model of Improved Holographic QCD.
Keywords :
Document type :
Journal articles
Cited literature [34 references]
http://hal.in2p3.fr/in2p3-00714892
Contributor : E. Kiritsis <>
Submitted on : Tuesday, April 9, 2019 - 2:32:50 PM
Last modification on : Monday, July 1, 2019 - 4:54:03 PM
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Bur.pdf
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### Citation
A. Buchel, U. Gursoy, E. Kiritsis. Holographic bulk viscosity: GPR vs EO. Journal of High Energy Physics, Springer, 2011, 9, pp.95. ⟨10.1007/JHEP09(2011)095⟩. ⟨in2p3-00714892⟩
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https://scholar.lib.ntnu.edu.tw/en/publications/thermally-modulated-hydrogenation-in-fesubxsubpdsub1-xsub-alloy-f | # Thermally modulated hydrogenation in FexPd1-x alloy films: Temperature-driven peculiar variation of magnetism
Po Chun Chang, Tzu Hung Chuang, Der Hsin Wei, Wen Chin Lin
Research output: Contribution to journalArticlepeer-review
1 Citation (Scopus)
## Abstract
The sensitive hydrogen effect on spintronic materials has been recently demonstrated to have high application potential. However, the correlation between hydrogen pressure (P H 2), temperature, and magnetic properties still remains unclear. In this study, the magnetic moment of Fe in an Fe-Pd alloy thin film was increased through hydrogen absorption, as evidenced by the enhanced X-ray magnetic circular dichroism signal of Fe. Hydrogen absorption and desorption hysteresis loops in the magnetic coercivity Hc-P H 2 diagram revealed that most hydrogen was absorbed when P H 2 was above 10 mbar and desorbed when P H 2 was approximately 10-6 mbar. The hydrogenation effect on the magnetism of an Fe-Pd alloy film was eliminated at an annealing temperature of 360 K without considerable hydrogen desorption. The annealing-driven cyclic enhancement of Hc was demonstrated because of the competition between thermal activation and H bonding. These results clearly reveal the critical temperature dependence and provide applicable knowledge of the hydrogenation effect on magnetic Pd-alloys.
Original language English Applied Physics Letters 116 10 https://doi.org/10.1063/1.5142625 Published - 2020 Mar 9
## ASJC Scopus subject areas
• Physics and Astronomy (miscellaneous) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.858637273311615, "perplexity": 10862.47497375105}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038064520.8/warc/CC-MAIN-20210411144457-20210411174457-00237.warc.gz"} |
https://answers.ros.org/question/219427/issue-with-move_base-for-a-robot-with-rotational-center-at-the-back/ | # issue with move_base for a robot with rotational center at the back edit
Hi all,
I have a robot with dimensions (LxWxH) in cm: 82x64x104 and the rotational center is 8 cm from the back of the robot. I am using rotary encoders to get the odometry message. I am using amcl for localization and move_base for planning with TrajectoryPlannerROS as the local planner and sbpl_lattice_planner as global planner.
Case I) If I specify the robot_footprint such that base_link is at the rotational center of the robot, then robot does not behave good. It has lot of jerks and move_base publishes erratic velocities on cmd_vel topic. For example: if max_vel_x: 0.5, then velocities published by move_base keeps on switching between 0.5 and 0.35 for a straight line motion of the robot which results in a jerky motion of the robot. Similarly, if max_vel_x: 0.6, same thing happens and velocities switches between 0.6 and 0.4. Also, there are lot of jerks in angular velocities also. The base_local_planner is not able to send correct and smooth velocities. I have tried changing the base_local_planner_params.yaml and it didn't help. :
#The footprint of the robot and associated padding
footprint: [[-0.08, -0.32], [-0.08, 0.32], [0.74, 0.32], [0.74, -0.32]]
Case II) But if I specify robot_footprint such that base_link is at the center of the robot (Geometric center), it behaves way better and there are no jerks in the robot and move_base publishes smooth linear and angular velocities although it has minor problems while turning in place (It thinks its rotating around geometric center but actually it rotates around the actual center of rotation) :
#The footprint of the robot and associated padding
footprint: [[-0.41, -0.32], [-0.41, 0.32], [0.41, 0.32], [0.41, -0.32]]
I know base_link and base_footprint should be at the rotational center of the robot but when I do it (case I), it behaves bad as compared to case where base_link and base_footprint are at the geometric center of the robot (case II) (I know this is not the correct way).
I have attached two videos which shows move_base (base_local_planner) publishing erratic velocities on cmd_vel topic in case I where base_link is at the rotational center of the robot:
Video 1
Video 2
Now, I need some help in making sure move_base publishes smooth velocities in Case I where base_link is at the rotational center of the robot (8 cm from back of the robot) which is different from geometric center of the robot. What parameters should I change and are there any other changes which I should make for it?
I have attached base_local_planner_params.yaml. I have tried changing the parameters in this file but it didn't help.
base_local_planner_params.yaml
#For full documentation of the parameters in this file, and a list of all the
#parameters available for TrajectoryPlannerROS, please see
#http://www.ros.org/wiki/base_local_planner
TrajectoryPlannerROS:
#Set the acceleration limits of the robot
acc_lim_th: 1.5 ...
edit retag close merge delete | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5216630101203918, "perplexity": 2207.3463439880493}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243988955.89/warc/CC-MAIN-20210509032519-20210509062519-00524.warc.gz"} |
http://math.sns.it/paper/2806/ | # Integral representation for functionals defined on $SBD^p$ in dimension two
created by iurlano on 01 Oct 2015
modified by focardi on 31 Oct 2016
[BibTeX]
Archive for Rational Mechanics and Analysis
Inserted: 1 oct 2015
Last Updated: 31 oct 2016
Year: 2016
Abstract:
We prove an integral representation result for functionals with growth conditions which give coercivity on the space $SBD^p(\Omega)$, for $\Omega\subset \mathbb{R}^2$ a bounded open Lipschitz set, $p\in(1,\infty)$. The space $SBD^p$ of functions whose distributional strain is the sum of an $L^p$ part and a bounded measure supported on a set of finite $\mathcal{H}^1$-dimensional measure appears naturally in the study of fracture and damage models. Our result is based on the construction of a local approximation by $W^{1,p}$ functions. We also obtain a generalization of Korn’s inequality in the $SBD^p$ setting. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9776127934455872, "perplexity": 528.3857409245702}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-39/segments/1505818685912.14/warc/CC-MAIN-20170919164651-20170919184651-00263.warc.gz"} |
https://www.physicslens.com/ | ## Appreciating the least square method of determining best-fit line
This interactive is designed to help students understand the statistical approach underpinning the drawing of a best-fit line for practical work. For context, our national exams have a practical component where students will need to plot their data, often following a linear trend, on graph paper and to draw a best-fit line to determine the gradient and y-intercept.
The instructions to students on how to draw the best-fit line is often procedural without helping students understand the principles behind it. For instance, students are often told to minimise and balance the separation of plots from the best-fit line. However, if there are one or two points that are further from the rest from the best-fit line (but not quite anomalous points that need to be disregarded), students would often neglect that point in an attempt to bring the best fit line as close to the remaining points as possible. This results in a drastic increase in the variance as the differences are squared in order to calculate the “the smallest sum of squares of errors”.
This applet allows students to visualise the changes in the squares, along with the numerical representation of the sum of squares in order to practise “drawing” the best-fit line using a pair of movable dots. A check on how well they have “drawn” the line can be through a comparison with the actual one.
Students can also rearrange the 6 data points to fit any distribution that they have seen before, or teachers can copy and modify the applet in order to provide multiple examples of distribution of points.
## Docking with Tides
Did this simple interactive upon request by a colleague who is teaching the JC1 topic of Oscillations.
Based on the following question, this is used as a quick visual to demonstrate why there must be a minimum depth before the boat approaches harbour.
The rise and fall of water in a harbour is simple harmonic. The depth varies between 1.0 m at low tide and 3.0 m at high tide. The time between successive low tides is 12 hours. A boat, which requires a minimum depth of water of 1.5 m, approaches the harbour at low tide. How long will the boat have to wait before entering?
The equation of the depth of water H based on the amplitude of the tide a can be given by $H = H_o + a \cos \omega t$ where $H_o$ is the average depth of the water.
$H = H_o + a \cos \omega t$
When H = 1.5m,
$1.5 = 2.0 – 1.0 \cos (\dfrac{2 \pi}{12}t)$
$\cos (\dfrac{2 \pi}{12}t) = 0.5$
$t = 2.0 h$
## Team-Based Learning with Google Form
Team-based learning is a pedagogical approach that facilitates learning through individual testing and group collaboration. Students are first given time to work on answers individually using the Individual Readiness Assurance Test (iRAT). They then work in teams to discuss the same problems in order to arrive at a consensus and check their answers against a pre-filled MCQ scratch card that reveals if their selected answer is correct or wrong, after which an immediate feedback is given. This is known as the Team Readiness Assurance Test (tRAT). If they got the answer wrong, teams get a chance to either appeal their answer or to try the same question again. A clarification session then ensues, with teachers focusing more on questions that teams have difficulty in.
Schools that want to use Team-Based Learning might either subscribe to platforms that allow for repeated attempts such as InteDashboard or purchase the Immediate Feedback Assessment Technique (IF-AT) scratch cards. There are some free options such as that from Cosma Gottardi.
However, I was wondering if a simple one could be done with Google Form, using the quiz mode together with branching options, to achieve the same results. I tested it out immediately last night and came up with this proof-of-concept. It seems possible and easy to edit.
I created a template for anyone who is keen to try:
## Centrifuge Toy
I designed this 3D teaching tool using Tinkercad and printed it out so that my colleague can use it to demonstrate the effect of a centrifuge.
As the toy is being spun, the ball bearings will appear to be thrown outwards. The centripetal forces that are meant to keep them in circular motion is made up of friction and any contact force due to the curvature of the base. If the rate of spin is sufficiently high, there will be insufficient contact force keeping the ball bearings in a circular path and hence, they will spiral outward and land into the cups found near the ends when the spinning stops.
Anyone can 3D-print this design as it had been uploaded into Thingiverse. This is my first original submission and can be found here. You will need 4 tiny balls of no more than 8 mm in diameter. The top is to be covered with a clear sheet of plastic cut-out after tracing the shape using a marker. The sheet can be stuck on the top using normal glue. This plastic cover serves to ensure the balls do not fly out if spun too fast.
## 3D printed Meissner tetrahedrons
These are my 3D-printed Meissner tetrahedrons, each maintaining the same height when rolled in any direction. The Meissner tetrahedron is a 3D version of the 2D Reuleaux triangle, which is a triangle with constant width. A flat platform can be placed on top and remain level when pushed around. The STL files can be obtained from Thingiverse. Sliced using Cura (with treelike supports) and printed with my Creality Ender 3.
Not exactly a physics teaching aid, but it demonstrates the affordance of 3D printing, which allows us to produce interesting objects overnight for lessons or if inspiration strikes. I am going to print a Gomboc next, which is an object when resting on a flat surface have just one stable and one unstable point of equilibrium, and is relevant to the topic of turning effects of forces.
## 3D printed teaching aids
I bought a Creality Ender 3D printer in 2020 (going at about $270 at Lazada now), at the height of the pandemic and have been using it to print physics-related teaching aids for a while, including balloon hovercrafts, catapults, a Pythagorean cup, tippy top and a vertical axis wind turbine. In addition to complete demonstration sets, it is also handy for printing parts to fix old demonstration sets such as a base for a standing cylinder with spouts at different heights. This is a video compiled with the objects that I printed in recent months. The lime green filament that I used were purchased at$16.40 for 1 kg from Shopee. Therefore, each of the prints shown in the picture cost between forty cents to four dollars’ worth of filament.
The first is a coin funnel that can be used to demonstrate how centripetal force keeps objects moving in circles. As the energy of the coins decreases due to friction, the radius of the circle gets smaller and its speed actually increases. This forms a cognitive dissonance that often surfaces when we discuss satellites losing altitude in orbit.
The second is a tensegrity structure which can be used to teach about moments and equilibrium.
The third is a marble run set that was really just lots of fun to watch rather than teaching any difficult concept other than energy changes.
The fourth is a series of optical illusions that can be used to promote thinking about how light from reflections travel.
The final print is a cup holder that can be swung in vertical loops with a cup full of water. This is the most popular print among my colleagues and will certainly be used in term 3 for the JC1 lessons on circular motion. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.48722517490386963, "perplexity": 823.9097054411804}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446711111.35/warc/CC-MAIN-20221206161009-20221206191009-00686.warc.gz"} |
https://www.xiyoubb.com/f3/7e/c12513a258942/page.htm | # 1月18日 Seog-Jin Kim 教授学术报告（数学与统计学院）
Asigned graph is a pair (G, \sigma), where G is a graph and $\sigma$ is a signature of G which assigns to each edge e a sign $\sigma(e) \in {1, -1}$. A k-coloringof G is a mapping $f: V(G) \to N_k$ such that for each edge e=uv, $f(x) \ne\sigma(e) f(y)$, where $N_k = \{\pm 1, \pm 2, …, \pm q\}$ if k=2q is even and $N_k= \{0, \pm 1, \pm 2, …, \pm q\}$ if k=2q+1 is odd. The chromatic number$\chi_{\pm}(G, \sigma)$ of (G, \sigma)is the minimum k such that $(G, \sigma)$ has a k-coloring. We define the signed chromatic number of a graph G to be $\chi_{\pm}(G) = max \{ \chi_{\pm}(G,\sigma): \sigma \mbox{ is a signature ofG} \}$. In this talk, we will give an overview of signed coloring, and present recent results in signed coloring. This is joint work with Ringi Kim and Xuding Zhu.
Seog-JinKim 教授毕业于美国伊利诺伊香槟分校（University of Illinois at Urbana-Champaign），师从于Douglas Brent West, 现为韩国建国大学（KonkukUniveristy）教授，主要研究领域是图的染色和图的结构，发表SCI 检索学术论文30余篇。
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https://www.physicsforums.com/threads/1st-order-diff-equ-vs-integral-tables.258499/ | # 1st order diff equ vs integral tables
1. Sep 22, 2008
### rppearso
I am at a dilemma trying to solve a simple first order differential equation of the form;
dT/dt + C1*T = C2 the solution to this differential equation is T = C2/C1 + exp(-C1t)
Which is equivalent to t= 1/-C1*ln(T+C2/C1)
The integral table states that the solution to an integral of the form:
dT/(aT+b) = 1/a*ln(a*T+b)
Both of these equations assume no constants of integration,
There is an extra C1 in the differential equation solution that is not in the integral.
2. Sep 22, 2008
### smallphi
When you take into account the constants of integration, the two formulas would be the same because constants of integration can absorb the differences.
For example the two expression below are exactly the same:
k1*exp(x)
exp(x+k2)
where k1, k2 are integration constants. The connection is k1=exp(k2). Any function of an integration constant is also an integration constant. You can reformulate integration constants that way to check if two seemingly different expressions are the same.
3. Sep 23, 2008
### rppearso
The integration constant for the differential equation would be in front of the exponential and when you rearanged the equation you would end up with;
ln((-C1*T+C2)/C*C1) and with the integral table you end up with ln(-C1*T+C2) + C even with integration constants taken into account I cant seem to properly shake the C1 out of my equation to match the integral tables. The differential equation and integral table should match.
Another question, do they use differential equation methods to solve complex integrals in the integral tables like use of integrating factors?
4. Sep 23, 2008
### smallphi
ln((-C1*T+C2)/C*C1) = ln(-C1*T+C2) +ln(C1/C)
Now ln(C1/C) is a function of integration constant that doesn't contain the variable, T in this case, so it can be considered integration constant too. That is confirmed by the fact that the value of ln(C1/C) doesn't depend on T and is arbitrary due to the presence of C so it behaves exactly like integration constant. Denote it by ln(C1/C) -> C and you get the second expression.
Last edited: Sep 23, 2008
5. Sep 23, 2008
### rppearso
I cant believe I forgot my log rules, actually wouldent it be ln(-C1*T+C2) - ln(C1*C). Either way it answers my question.
Thank you,
Ron
BTW are the integral tables created through differential equation methods of solving. Some of thoes complex integrals are not straight forward to solve using integration rules.
Last edited: Sep 23, 2008
6. Sep 23, 2008
### smallphi
Indefinite integrals are solved by substitutions, change of integration variables, integration by parts etc. the usual tricks in a calculus book. The substitutions/change of variables are not always obvious.
Some definite integrals on the real axis are solved by integration over contours in the complex plane.
Similar Discussions: 1st order diff equ vs integral tables | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9778061509132385, "perplexity": 1061.1046708777858}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501173872.97/warc/CC-MAIN-20170219104613-00206-ip-10-171-10-108.ec2.internal.warc.gz"} |
http://zgkj.cast.cn/EN/abstract/abstract8747.shtml | • •
### Analysis and Calculation of Separation Process of Spacecraft Modules
Xiao Yelun Li Chenguang (Beijing University of Aeronautics and Astronautics, Beijing 100083)
• Published:2005-08-25
Abstract: The process of escape and sucedent emergency separation of spacecraft modules when spacecraft rising besides aerosphere is a complex process of multi-body relative motion. The mathematic models of relative trajectory motion and attitude motion for that process, including dynamic, kinematic and geometric equations, are constructed. The combinatorial objects are defined, the relation between subject and object is emphasized, and the flight phase according to practical situation is partitioned. On the base of mathematic model, body definition and phase partition, a large-scale software to analyze and simulate is established. Some result samples of typical condition are given. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.25633421540260315, "perplexity": 3980.4765232073473}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875148850.96/warc/CC-MAIN-20200229083813-20200229113813-00129.warc.gz"} |
http://proceedings.mlr.press/v70/scaman17a.html | # Optimal Algorithms for Smooth and Strongly Convex Distributed Optimization in Networks
Kevin Scaman, Francis Bach, Sébastien Bubeck, Yin Tat Lee, Laurent Massoulié ;
Proceedings of the 34th International Conference on Machine Learning, PMLR 70:3027-3036, 2017.
#### Abstract
In this paper, we determine the optimal convergence rates for strongly convex and smooth distributed optimization in two settings: centralized and decentralized communications over a network. For centralized (i.e. master/slave) algorithms, we show that distributing Nesterov’s accelerated gradient descent is optimal and achieves a precision $\varepsilon > 0$ in time $O(\sqrt{\kappa_g}(1+\Delta\tau)\ln(1/\varepsilon))$, where $\kappa_g$ is the condition number of the (global) function to optimize, $\Delta$ is the diameter of the network, and $\tau$ (resp. $1$) is the time needed to communicate values between two neighbors (resp. perform local computations). For decentralized algorithms based on gossip, we provide the first optimal algorithm, called the multi-step dual accelerated (MSDA) method, that achieves a precision $\varepsilon > 0$ in time $O(\sqrt{\kappa_l}(1+\frac{\tau}{\sqrt{\gamma}})\ln(1/\varepsilon))$, where $\kappa_l$ is the condition number of the local functions and $\gamma$ is the (normalized) eigengap of the gossip matrix used for communication between nodes. We then verify the efficiency of MSDA against state-of-the-art methods for two problems: least-squares regression and classification by logistic regression. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9623625874519348, "perplexity": 473.9580719550083}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-09/segments/1550247515149.92/warc/CC-MAIN-20190222094419-20190222120419-00206.warc.gz"} |
https://www.glamsham.com/music/lyrics/song-lyrics-i-know-what-you-did-last-summer-by-shawn-mendes-and-camila-cabello | Song lyrics: I Know What You Did Last Summer by Shawn Mendes and Camila Cabello
Ah-ah, he-ey
Ah-ah, ah-ah
Ah-ah, he-ey
Ah-ah, ah-ah
He knows
Dirty secrets that I keep
Does he know it's killing me?
He knows, he knows
D-d-does he know
Another's hands have touched my skin
I won't tell him where I've been
He knows, he knows, he knows
It's tearing me apart
She's slipping away
Am I just hanging on to all the words she used to say?
The pictures on her phone
She's not coming home
Coming home, coming home
I know what you did last summer
Just lied to me, "there's no other"
I know what you did last summer
Tell me where you've been
I know what you did last summer
Look me in the eyes, my lover
I know what you did last summer
Tell me where you've been
I know, I know, I know, I know
I know, I know, I know
(He-ey)
I know, I know, I know, I know
I know, I know, I know
I didn't mean it, no, I didn't mean it, mean it, no
Can't seem to let you go, can't seem to hold you close
I know
When she looks me in the eyes
They don't seem as bright
No more, no more
I know
That she loved me at one time
Would I promise her that night
Cross my heart and hope to die
It's tearing me apart
She's slipping away
Am I just hanging on to all the words she used to say?
The pictures on her phone
She's not coming home
Oh, na, na, na, yeah
I know what you did last summer
Just lied to me, "there's no other"
I know what you did last summer
Tell me where you've been
I know what you did last summer
Look me in the eyes, my lover
I know what you did last summer
Tell me where you've been
I know, I know, I know, I know
I know, I know, I know
I know, I know, I know, I know
I know, I know, I know
Can't seem to let you go, can't seem to keep you close
Can't seem to let you go, can't seem to keep you close
Tell me where you've been lately
Tell me where you've been lately
Tell me where you've been lately
Tell me where you've been lately
Can't seem to keep you close, can't seem to let you go
I know you didn't mean it, though
I know you didn't mean it, though
Tell me you didn't mean it, though
Tell me you didn't mean it, though
I know you didn't mean it, though. I wanna know you mean it though
I know you didn't mean it though
I know you didn't mean it though
I can't seem to let you go, can't seem to hold you close
I know what you did last summer
Just lied to me, "there's no other"
I know what you did last summer
Tell me where you've been
I know what you did last summer
Look me in the eyes, my lover
I know what you did last summer
Tell me where you've been
I know, I know, I know, I know
I know, I know, I know
I know, I know, I know, I know
I know, I know, I know
I know, I know, I know, I know
I know, I know, I know
I know, I know, I know, I know
I know, I know, I know
I know | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9016371369361877, "perplexity": 6855.4387268540295}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046157039.99/warc/CC-MAIN-20210805193327-20210805223327-00228.warc.gz"} |
https://hal.univ-lorraine.fr/hal-01267377 | # Expected evolution of a Technosol derived from excavated Callovo-Oxfordian clay material
Abstract : Raw geological materials excavated then piled on large surface areas are submitted to pedogenetic factors. Knowledge of the evolution of this freshly exposed material is required to predict the newly developed Technosol and the corresponding ecosystem. The pedogenetic evolution of a Technosol developed on excavated Callovo-Oxfordian clay minerals (COx) is assessed from the analysis of natural soils developed on analogous materials. Work was based on the hypothesis that the evolution of raw geological materials could be deduced from that of natural soils on similar outcrops in similar climatic conditions. A comparison was made on the basis of mineralogical and geochemical criteria between the unweathered clays and soil material collected from the horizons of two reference pedons on a COx outcrop in North-Eastern France, used by forest or agriculture, and a 10-year-old Technosol derived from freshly excavated COx material piled under outdoor climatic conditions. Soil profiles were described and each sampled horizon was characterized for mineralogy, and physical and chemical properties. Soil profiles were classified as Vertic Stagnic Hypereutric Cambisol (Forest) and Vertic Stagnic Calcaric Cambisol (Meadow), and compared to the Calcaric Technosol (no vegetation yet). They clearly showed brunification and decarbonatization as the major processes having governed their evolution. Signs of clay leaching were also visible on the forest soil. A fairly good adequacy was observed between soil material sampled in the soil deep horizons (2.5 m), the Technosol deep horizon (1.7 m), and the freshly excavated material. Slight differences were recorded, however, i.e., salt loss (NaCl), sulfide oxidation, and precipitation of gypsum from sulfate and calcium released by decarbonatization, as earlier observed in leaching experiments. Salt loss is a rapid process almost completed to the same extent in the Technosol after 10 years than in the Calcaric Cambisol after centuries. The soil under forest showed signs of stronger pedogenetic evolution than the soil submitted to agriculture (meadow), probably because the latter has been refreshed by man-induced erosion. COx evolution can be predicted from the analysis of soils developed on similar outcrops. The Technosol developed on these carbonated materials would evolve as a result of extremely rapid leaching of the soluble phases, then surface enrichment of organic matter, surface decarbonatization, and progressive brunification of the whole profile as the major processes, and give rise to a Cambisol. Technosol study is an interesting approach for dating the age of pedogenetic processes.
Type de document :
Article dans une revue
Journal of Soils and Sediments, Springer Verlag, 2015, 15 (2), pp.332-346. 〈10.1007/s11368-014-1020-3〉
Domaine :
Liste complète des métadonnées
https://hal.univ-lorraine.fr/hal-01267377
Contributeur : Lrgp Ul <>
Soumis le : jeudi 4 février 2016 - 12:42:24
Dernière modification le : mercredi 25 juillet 2018 - 11:13:12
### Citation
Nicolas Scholtus, Guillaume Echevarria, Louis Florentin, Marie-Laure Bonis, Philippe De Donato, et al.. Expected evolution of a Technosol derived from excavated Callovo-Oxfordian clay material. Journal of Soils and Sediments, Springer Verlag, 2015, 15 (2), pp.332-346. 〈10.1007/s11368-014-1020-3〉. 〈hal-01267377〉
### Métriques
Consultations de la notice | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8350310325622559, "perplexity": 14720.03082790005}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-39/segments/1537267162809.73/warc/CC-MAIN-20180926002255-20180926022655-00158.warc.gz"} |
http://www.biomedsearch.com/cluster/89/Hypertension/sub-79.html | Search Results
Results 1 - 50 of 1130 1 2 3 4 5 6 7 8 9 10 > 1 Amador Espejo Genaro Gustavo GG Centre Especial de Recerca Planta de Tecnologia dels Aliments (CERPTA), XaRTA, TECNIO, MALTA Consolider, Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain; Departamento de Ingeniería Química, Alimentos y Ambiental, Universidad de las Américas Puebla, Sta. Catarina Mártir. Cholula, Puebla C.P. 72810, - - 2014 Ultra High-Pressure Homogenization treatments at 300 MPa with inlet temperatures (Ti) of 55, 65, 75 and 85 °C were applied to commercial Ultra High Temperature treated whole milk inoculated with Bacillus cereus, Bacillus licheniformis, Bacillus sporothermodurans, Bacillus coagulans, Geobacillus stearothermophilus and Bacillus subtilis spores in order to evaluate the inactivation level achieved. ... 2 Bova Jonathan F JF 1Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine , Baton Rouge, Louisiana , - - 2014 ABSTRACT Purpose/Aim: The primary objective was to evaluate the effect of a bupivacaine mandibular nerve block on intraoperative blood pressure (BP) and heart rate (HR) in response to surgical stimulation and the need for systemic analgesics postoperatively. We hypothesized that a mandibular nerve block would decrease the need for systemic ... 3 Colombo R R Anaesthesiology and Intensive Care Unit, Azienda Ospedaliera "L.Sacco", Milano, Italy. - - 2014 Surgical Plethysmographic Index (SPI), calculated from pulse photo-plethysmographic amplitude oscillations, has been proposed as a tool to measure nociception anti-nociception balance during general anaesthesia, but it is affected by several confounding factor that alter the autonomic nervous system (ANS) modulation. We hypotesised that SPI may be mainly affected by sympathetic ... 4 McNally Sara S *Department of Ophthalmology, Mater Misericordiae University Hospital †UCD School of Medicine and Medical Science, University College Dublin, Dublin, - - 2014 It is currently estimated that 60 to 70 million people worldwide are affected by open-angle glaucoma and the majority of patients who present to clinic have raised intraocular pressure, visual field loss, and cupping of the optic nerve. Although exfoliation glaucoma (XFG) correlates with age, it is the most common ... 5 Kim Ji-Yeon JY Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, - - 2014 Rapid evaluation and management of intracranial pressure (ICP) can help to early detection of increased ICP and improve postoperative outcomes in neurocritically-ill patients. Sonographic measurement of optic nerve sheath diameter (ONSD) is a non-invasive method of evaluating increased intracranial pressure at the bedside. In the present study, we hypothesized that ... 6 Dick Thomas E TE Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, United States; Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States. Electronic address: - - 2014 Slow deep breathing (SDB) has a therapeutic effect on autonomic tone. Our previous studies suggested that coupling of the cardiovascular to the respiratory system mediates plasticity expressed in sympathetic nerve activity. We hypothesized that SDB evokes short-term plasticity of cardiorespiratory coupling (CRC). We analyzed respiratory frequency (fR), heart rate and ... 7 Caffery Terrell S TS Emergency Medicine Residency Program, LSU Health-Baton Rouge, 5246 Brittany Drive, Baton Rouge, LA 70808. Electronic address: - - 2014 The purpose of this study was to determine if patients with nontraumatic causes of elevated intracranial pressure (ICP) could be identified by ultrasound measurement of optic nerve sheath diameter (ONSD). It was hypothesized that an ONSD greater than or equal to 5 mm would identify patients with elevated ICP. This ... 8 Fritz Thomas Hans TH Department of Neurology, Max Planck Institute for Human Cognitive and Brain Science, Leipzig, Germany; Institute for Psychoacoustics and Electronic Music, University of Ghent, Ghent, Belgium; Department of Nuclear Medicine, University of Leipzig, Leipzig, - - 2014 Given a possible effect of estrogen on the pleasure-mediating dopaminergic system, musical appreciation in participants whose estrogen levels are naturally elevated during the oral contraceptive cycle and pregnancy has been investigated (n = 32, 15 pregnant, 17 nonpregnant; mean age 27.2). Results show more pronounced blood pressure responses to music in pregnant ... 9 Welsh Faithlee Elizabeth FE North East Region Health Authority, Port Antonio, - - 2014 Determine the extent to which the lifestyles of Jamaican men with hypertension met the guidelines of the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). Following informed consent, a convenience sample of Jamaican men with hypertension (n = ... 10 Zhang Jie J Key Laboratory of Materials Physics, Institute of Solid State Physics, CAS, and Department of Physics, University of Science and Technology of China, Hefei 230031, - - 2014 The first-principles method and the evolutionary algorithm are used to identify stable high pressure phases of potassium azide (KN3). It has been verified that the stable phase with space group I4/mcm below 22 GPa, which is consistent with the experimental result, will transform into the C2/m phase with pressure increasing. These ... 11 Topakian Raffi R Department of Neurology, Klinikum Wels-Grieskirchen, Wels, - - 2014 Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal-dominant disorder associated with recurrent mononeuropathies following compression or trivial trauma. Reports on sciatic neuropathy as the presenting manifestation of HNPP are very scarce. We report on a 21-year-old previously healthy man who was admitted with sensorimotor deficits in his ... 12 Verdonck Philip P Department of Anaesthesiology, University Hospital Antwerp, Edegem, - - 2014 During robot assisted laparoscopic radical prostatectomy (RALRP), a CO2 pneumoperitoneum (CO2PP) is applied and the patient is placed in a head-down position. Intracranial pressure (ICP) is expected to acutely increase under these conditions. A non-invasive method, the optic nerve sheath diameter (ONSD) measurement, may warn us that the mechanism of ... 13 Nelson Emily S ES NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, OH 44135, USA. - - 2014 Although changes to visual acuity in spaceflight have been observed in some astronauts since the early days of the space program, the impact to the crew was considered minor. Since that time, missions to the International Space Station have extended the typical duration of time spent in microgravity from a ... 14 Karimi N - - 2014 Objectives: The objective of this study was to investigate the abnormalities in sperm after exposure to hydrostatic pressure.Background: Hydrostatic pressure acting on the cells is one of the fundamental environmental mechanical forces. Disorders of relationship between the cells and this mechanical force, such as when pressure varies beyond physiological limits, ... 15 Amador-Espejo G G GG Centre Especial de Recerca Planta de Tecnologia dels Aliments (CERPTA), XaRTA, TECNIO, MALTA Consolider, Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain; Departamento de Ingeniería Química, Alimentos y Ambiental, Universidad de las Américas Puebla, Sta. Catarina Mártir, Cholula, Puebla, C.P. 72810, - - 2013 The effect of ultra-high-pressure homogenization (UHPH) on raw whole milk (3.5% fat) was evaluated to obtain processing conditions for the sterilization of milk. Ultra-high-pressure homogenization treatments of 200 and 300 MPa at inlet temperatures (Ti) of 55, 65, 75, and 85°C were compared with a UHT treatment (138°C for 4 ... 16 Bergamaschi Mateus M MM Department of Neuroscience and Behavior, Ribeirão Preto Medical School, University of São Paulo, SP, Brazil; Department of Clinical, Toxicological and Food Sciences Analysis, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, SP, Brazil; CNPq, National Institute for Translational Medicine (INCT-TM), Rio de Janeiro, - - 2014 We investigated the hypothesis that rimonabant, a cannabinoid antagonist/inverse agonist, would increase anxiety in healthy subjects during a simulation of the public speaking test. Participants were randomly allocated to receive oral placebo or 90 mg rimonabant in a double-blind design. Subjective effects were measured by Visual Analogue Mood Scale. Physiological parameters, ... 17 Al-Mariri Ayman A Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, - - 2013 The role of low-pressure RF plasma in the inactivation of Escherichia coli O157, Klebsiella pneumoniae, Proteus mirabilis, and Enterobacter sakazakii using N2-O2 and SF6 gases was assessed. 1×10(9) colony-forming units (CFUs) of each bacterial isolate were placed on three polymer foils. The effects of pressure, power, distance from the source, ... 18 Reshetnikov Evgeny A - - 2013 Malfunctioning of the cardiovascular system during pregnancy may be responsible for adverse effects on the 'mother-fetus' system. The cardiovascular system of a pregnant woman develops adaptation to the increased load. Angiotensin-converting enzyme (ACE) is known to play an important role in the adaptation. The present study was designed to investigate ... 19 Hasegawa Yumiko - - 2013 This study examined the effect of anxiety states on the relationship between golf-putting distance and performance in an environment requiring high movement accuracy. Twenty-three amateur golfers attempted 15 putts at each of three putting distances, 1.25, 1.50, and 1.75m, under conditions characterized by both control demands and pressure. All attempts ... 20 Madan Anjana - - 2013 Exposure to media violence is related to anxiety in youth, but the causality of the effect has not been established. This experimental study examined the effects of media violence on anxiety, blood pressure, and heart rate in late adolescents. We also examined whether these responses varied by previous exposure to ... 21 Pilipovik V - - 2013 A study of a self-organizing controller is implemented in a way that response to controlled system follows the desired given by the model. The self-organizing controller has proven to be a valuable tool in sterilization equipment in order to verify the capacity of the response to any change in the ... 22 Beaulieu-Houle Guillaume - - 2013 The two polymorphs of copper phthalocyanine, α- and β-CuPc, have been examined by micro-Raman spectroscopy at pressures approaching 5.0GPa. The metastable α-polymorph does not exhibit any structural changes, while the more thermodynamically stable β-polymorph does exhibit a reversible phase transition at 2.0GPa. The pressure dependences (dν/dP) for a selected number ... 23 Qin Jiaxu - - 2013 hyperbranched polyesteramide, multifunctional catalyst, reverse osmosis membrane, ultralow-pressure. 24 Mandel Susan E - - 2013 PurposeThe purpose of the feasibility study was to compare the effects of music-assisted relaxation and imagery, administered via compact disc recording (MARI CD) without therapeutic intervention, to the effects of music therapy (MT), facilitated by a board-certified music therapist, on selected health outcomes of patients enrolled in diabetes self-management education/training ... 25 Bullarbo Maria - - 2013 PURPOSE: To assess if hypertension during the last part of pregnancy could be prevented by magnesium supplementation. METHODS: Pregnant primagravida women from a local antenatal care unit were given an oral supply of 300 mg magnesium as citrate or placebo from pregnancy week 25 in a randomised double-blind setup. Blood pressure ... 26 Tibollo S - - 2013 Background: The contamination of shellfish with gastroenteric viruses may cause outbreaks because they are often eaten raw or under-cooked. High-hydrostatic pressure treatments have already proven to be effective in reducing high viral load in shellfish samples. The objectives are the assessment of the viral load reduction of contaminated clams using ... 27 Aouadhi Chedia - - 2013 AIMS: To investigate the combined effect of hydrostatic pressure, moderate temperature, and nisin on the inactivation of Bacillus sporothermodurans spores which are known to be contaminant of dairy products and to be extremely heat-resistant. METHODS AND RESULTS: A central composite experimental design with three factors, using response surface methodology, was ... 28 Porta Alberto - - 2013 The information carried by heart period (HP) given systolic arterial pressure (SAP) changes was assessed to characterize spontaneous baroreflex (i.e. the relation linking SAP variability to HP variability): the larger the information carried by HP given SAP changes, the greater the unpredictability of HP given SAP variations, the smaller the ... 29 Valencia-Flores Dora C DC Centre Especial de Recerca Planta de Tecnologia dels Aliments (CERPTA), XaRTA, TECNIO, MALTA-Consolider Group, Dept. de Ciència Animal i dels Aliments, Facultat de Veterinària, Univ., Autònoma de Barcelona, 08193, Bellaterra, Barcelona, - - 2013 The effects of ultra-high-pressure homogenization (UHPH) at 200 and 300 MPa, in combination with different inlet temperatures (55, 65, and 75 °C) on almond beverages with lecithin (AML) and without lecithin (AM), were studied. UHPH-treated samples were compared with the base product (untreated), pasteurized (90 °C, 90 s), and ultra-high-temperature ... 30 Uthicke Sven S Australian Institute of Marine Science, Townsville, Queensland, - - 2013 Coral reefs are marine biodiversity hotspots, but their existence is threatened by global change and local pressures such as land-runoff and overfishing. Population explosions of coral-eating crown of thorns sea stars (COTS) are a major contributor to recent decline in coral cover on the Great Barrier Reef. Here, we investigate ... 31 Leisegang K - - 2012 The metabolic syndrome (MetS) is a constellation of various risk factors. This study aimed to investigate the effect of MetS on testosterone and progesterone, and semen parameters, in a case-controlled pilot study. Male patients (n = 54) had body mass index, waist-to-hip ratio (WHR) and blood pressure recorded. Blood was analysed for ... 32 Ruiz-Espinosa H - - 2012 Multiple-pass UHPH was used for reducing microbial population of both indigenous spoilage microflora in whole raw milk and a baroresistant pathogen (Staphylococcus aureus) inoculated in whole sterile milk to define pasteurization-like processing conditions. Response surface methodology was followed and multiple response optimization of UHPH operating pressure (OP) (100, 175, 250 ... 33 Tan Xiao - - 2012 We report the high-pressure response of three forms (α, δ, and γ) of pyrazinamide (C5H5N3O, PZA) by in situ Raman spectroscopy and synchrotron X-ray diffraction techniques with a pressure of about 14 GPa. These different forms are characterized by various intermolecular bonding schemes. High-pressure experimental results show that the γ ... 34 Zapala Kinga - - 2012 Dispersions of isotactic polypropylene (PP) particles in polystyrene (PS) were produced by interfacially driven breakup of nanolayers in multilayered systems that were fabricated by means of layer-multiplying coextrusion. The droplet size was controlled by the individual PP layer thickness ranging from 12 to 200 nm. In addition, PP was melt blended ... 35 Yerram Preethi - - 2012 Incretin-based therapies are currently being used in the treatment of type 2 diabetes mellitus (T2DM). Apart from glycemic control, these agents have been shown to have multiple extra-pancreatic effects, including their role in blood pressure (BP) regulation. This article will review the origins of incretins, the incretin axis, possible mechanisms ... 36 Kuo Chin-Chang - - 2012 We report on the impact of different size particles on the collapse of a Langmuir monolayer. We use a SDS-DODAB monolayer because it is known to reversibly collpase under compression and expansion cycles. Particles with diameters of 1 $\mu$m, 0.5 $\mu$m, 0.1 $\mu$m, and 20 nm are deposited on the ... 37 Agarwal Rajiv - - 2012 Resistant hypertension is defined as blood pressure (BP) that remains above goal (such as 140/90 mmHg or more) in spite of the concurrent use of three antihypertensive agents of different classes. Ideally, one of the three agents should be a diuretic and all agents should be prescribed at optimal dose ... 38 Preston Mason R - - 2012 Clinical trials have reported reduced cardiovascular events with certain antihypertensive agents at a rate that could not be predicted by changes in brachial arterial pressure alone. These findings may be explained, in part, by pleiotropic effects of these agents and modulation of central blood pressures. This review focuses on the ... 39 Gerdin Anna-Karin - - 2012 To maximize the sensitivity of detecting affects of genetic variants in mice, variables have been minimized through the use of inbred mouse lines, by eliminating infectious organisms and controlling environmental variables. However, the impact of standard animal husbandry and experimental procedures on the validity of experimental data is under appreciated. ... 40 Craigie Eilidh - - 2012 In vivo, the enzyme 11β-hydroxysteroid dehydrogenase type 2 influences ligand access to the mineralocorticoid receptor. Ablation of the encoding gene, HSD11B2, causes the hypertensive syndrome of apparent mineralocorticoid excess. Studies in humans and experimental animals have linked reduced 11β-hydroxysteroid dehydrogenase type 2 activity and salt sensitivity of blood pressure. In ... 41 Lillie M A - - 2012 This study was undertaken to understand elastin's role in the mechanical homeostasis of the arterial wall. The mechanical properties of elastin vary along the aorta, and we hypothesized this maintained a uniform mechanical environment for the elastin, despite regional variation in loading. Elastin's physiological loading was determined by comparing the ... 42 Mrozek Segolene - - 2012 BACKGROUND:: Controlled mechanical ventilation is associated with ventilator-induced diaphragmatic dysfunction, which impedes weaning from mechanical ventilation. To design future clinical trials in humans, a better understanding of the molecular mechanisms using knockout models, which exist only in the mouse, is needed. The aims of this study were to ascertain the ... 43 Rubini Alessandro - - 2012 While some experimental data suggest that erythropoietin (EPO) influences respiratory mechanics, reports on scientific trials are lacking. In the present work, respiratory mechanics were measured using the end-inflation occlusion method in control and EPO treated anaesthetized and positive-pressure ventilated rats. Causing an abrupt inspiratory flow arrest, the end-inflation occlusion method ... 44 Clarke John O - - 2012 High-resolution manometry has added significantly to our current understanding of esophageal motor function by providing improved detail and a data analysis paradigm that is more akin to an imaging format. Esophageal pressure topography provides a seamless dynamic representation of the pressure profile through the entire esophagus and thus, is able ... 45 Bouley Richard R Program in Membrane Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. - - 2012 The protease corin generates atrial natriuretic peptide and affects blood pressure and salt-water homeostasis. Under dietary salt challenge, corin knockout mice show blood pressure exacerbation and significant weight gain due to water and salt retention. This phenotype involves the epithelial sodium channel but is independent of the renin-angiotensin-aldosterone system. This ... 46 Siewert Stefan - - 2012 This paper describes methods for design, manufacturing and characterization of a micro-mechanical valve for a novel glaucoma implant. The implant is designed to drain aqueous humour from the anterior chamber of the eye into the suprachoroidal space in case of an elevated intraocular pressure (IOP). In contrast to any existing ... 47 Mireles-Cabodevila Eduardo - - 2012 Mechanical ventilation is a life-saving intervention for respiratory failure and thus has become the cornerstone of the practice of critical care medicine. A mechanical ventilation mode describes the predetermined pattern of patient-ventilator interaction. In recent years there has been a dizzying proliferation of mechanical ventilation modes, driven by technological advances ... 48 Sarafidis Pantelis A - - 2012 Hypertensive crises are categorized as hypertensive emergencies and urgencies depending on the presence of acute target-organ damage; the former are potentially life-threatening medical conditions, requiring urgent treatment under close monitoring. Although several short-acting intravenous antihypertensive agents are approved for this purpose, until recently little evidence from proper trials on the ... 49 Schmidt Matthieu - - 2012 OBJECTIVES:: To compare the respective impact of pressure support ventilation and naturally adjusted ventilatory assist, with and without a noninvasive mechanical ventilation algorithm, on patient-ventilator interaction. DESIGN:: Prospective 2-month study. SETTING:: Adult critical care unit in a tertiary university hospital. PATIENTS:: Seventeen patients receiving a prophylactic postextubation noninvasive mechanical ventilation. ... 50 Knockaert Griet - - 2012 In the present study, the effect of equivalent thermal and high pressure processes at pasteurization and sterilization intensities on some health related properties of high pressure homogenized tomato puree containing oil were investigated. Total lycopene concentration, cis-lycopene content and in vitro lycopene bioaccessibility were examined as health related properties. Results ... 1 2 3 4 5 6 7 8 9 10 > | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.39705321192741394, "perplexity": 8877.481903263335}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501171171.24/warc/CC-MAIN-20170219104611-00498-ip-10-171-10-108.ec2.internal.warc.gz"} |
http://techgtholpadi.blogspot.com/2010/12/using-unicode-in-latextex.html | ## Friday, December 31, 2010
### Using Unicode in Latex/Tex
To use Hindi Unicode, do the following -
In the .tex file include the line -
\font\texthi="Lohit Hindi:script=deva,mapping=tex-text" at 11pt.
(Remember to exclude the full stop at the end!)
Enter Hindi unicode text in the document as -
Some English text {\texthi हिन्दी...} more English text...
Compile the document using Xetex or XeLatex.
"texthi" is the name of the command we just defined to indicate Unicode text. You can give any other name, e.g. \font\abcd="...".
"Lohit Hindi" (remember the space between Lohit and Hindi) is the name of an Open Truetype Font (OTF) installed in the system. You can specify any other font that is installed. In Ubuntu, you can see what fonts are installed as follows -
Goto Main Taskbar -> System -> Preferences -> Appearance -> (Popup opens) -> Click 'Fonts' tab -> Try to change any of the fonts e.g. Application font. You get another popup where the fonts are listed under 'Family'. You can use any of these fonts instead of "Lohit Hindi".
"deva" is a tag that specifies which script (and hence which unicode range) should be used. Hindi uses the devanagari script. For other scripts, find out which script tag to use.
"mapping=tex-text" - I don't know what this. If you do, please tell me. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9330021739006042, "perplexity": 5935.5581207459745}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084890771.63/warc/CC-MAIN-20180121135825-20180121155825-00578.warc.gz"} |
http://www.gradesaver.com/the-absolutely-true-diary-of-a-part-time-indian/q-and-a/who-are-the-most-important-character-to-the-storyline-254479 | # who are the most important character to the storyline?
other then junior, justify other important characters to the storyline. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8712279200553894, "perplexity": 7146.765185490033}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-30/segments/1500549427750.52/warc/CC-MAIN-20170727082427-20170727102427-00196.warc.gz"} |
https://en.wikipedia.org/wiki/Hyperbola | Hyperbola
A hyperbola is an open curve with two branches, the intersection of a plane with both halves of a double cone. The plane does not have to be parallel to the axis of the cone; the hyperbola will be symmetrical in any case.
Hyperbola (red): features
In mathematics, a hyperbola (plural hyperbolas or hyperbolae) is a type of smooth curve lying in a plane, defined by its geometric properties or by equations for which it is the solution set. A hyperbola has two pieces, called connected components or branches, that are mirror images of each other and resemble two infinite bows. The hyperbola is one of the three kinds of conic section, formed by the intersection of a plane and a double cone. (The other conic sections are the parabola and the ellipse. A circle is a special case of an ellipse.) If the plane intersects both halves of the double cone but does not pass through the apex of the cones, then the conic is a hyperbola.
Hyperbolas arise in many ways:
• as the curve representing the function ${\displaystyle f(x)=1/x}$ in the Cartesian plane,
• as the path followed by the shadow of the tip of a sundial,
• as the shape of an open orbit (as distinct from a closed elliptical orbit), such as the orbit of a spacecraft during a gravity assisted swing-by of a planet or more generally any spacecraft exceeding the escape velocity of the nearest planet,
• as the path of a single-apparition comet (one travelling too fast ever to return to the solar system),
• as the scattering trajectory of a subatomic particle (acted on by repulsive instead of attractive forces but the principle is the same),
• in radio navigation, when the difference between distances to two points, but not the distances themselves, can be determined,
and so on.
Each branch of the hyperbola has two arms which become straighter (lower curvature) further out from the center of the hyperbola. Diagonally opposite arms, one from each branch, tend in the limit to a common line, called the asymptote of those two arms. So there are two asymptotes, whose intersection is at the center of symmetry of the hyperbola, which can be thought of as the mirror point about which each branch reflects to form the other branch. In the case of the curve ${\displaystyle f(x)=1/x}$ the asymptotes are the two coordinate axes.
Hyperbolas share many of the ellipses' analytical properties such as eccentricity, focus, and directrix. Typically the correspondence can be made with nothing more than a change of sign in some term. Many other mathematical objects have their origin in the hyperbola, such as hyperbolic paraboloids (saddle surfaces), hyperboloids ("wastebaskets"), hyperbolic geometry (Lobachevsky's celebrated non-Euclidean geometry), hyperbolic functions (sinh, cosh, tanh, etc.), and gyrovector spaces (a geometry proposed for use in both relativity and quantum mechanics which is not Euclidean).
Etymology and history
The word "hyperbola" derives from the Greek ὑπερβολή, meaning "over-thrown" or "excessive", from which the English term hyperbole also derives. Hyperbolae were discovered by Menaechmus in his investigations of the problem of doubling the cube, but were then called sections of obtuse cones.[1] The term hyperbola is believed to have been coined by Apollonius of Perga (c. 262–c. 190 BC) in his definitive work on the conic sections, the Conics.[2] The names of the other two general conic sections, the ellipse and the parabola, derive from the corresponding Greek words for "deficient" and "applied"; all three names are borrowed from earlier Pythagorean terminology which referred to a comparison of the side of rectangles of fixed area with a given line segment. The rectangle could be "applied" to the segment (meaning, have an equal length), be shorter than the segment or exceed the segment.[3]
Definition of a hyperbola as locus of points
Hyperbola: definition by the distances of points to two fixed points (foci)
Hyperbola: definition with director circle
A hyperbola can be defined geometrically as a set of points (locus of points) in the Euclidean plane:
• A hyperbola is a set of points, such that for any point ${\displaystyle P}$ of the set, the absolute difference of the distances ${\displaystyle |PF_{1}|,\ |PF_{2}|}$ to two fixed points ${\displaystyle F_{1},F_{2}}$ (the foci), is constant, usually denoted by ${\displaystyle 2a,\ a>0\ :}$
${\displaystyle H=\{P\mid ||PF_{2}|-|PF_{1}||=2a\}\ .}$
The midpoint ${\displaystyle M}$ of the line segment joining the foci is called the center of the hyperbola. The line through the foci is called the major axis. It contains the vertices ${\displaystyle V_{1},V_{2}}$, which have distance ${\displaystyle a}$ to the center. The distance ${\displaystyle c}$ of the foci to the center is called the focal distance or linear eccentricity. The quotient ${\displaystyle {\tfrac {c}{a}}}$ is the eccentricity ${\displaystyle e}$.
The equation ${\displaystyle ||PF_{2}|-|PF_{1}||=2a}$ can be viewed in a different way (see diagram):
If ${\displaystyle c_{2}}$ is the circle with midpoint ${\displaystyle F_{2}}$ and radius ${\displaystyle 2a}$, then the distance of a point ${\displaystyle P}$ of the right branch to the circle ${\displaystyle c_{2}}$ equals the distance to the focus ${\displaystyle F_{1}}$:
${\displaystyle |PF_{1}|=|Pc_{2}|.}$
${\displaystyle c_{2}}$ is called the circular directrix (related to focus ${\displaystyle F_{2}}$) of the hyperbola.[4][5] In order to get the left branch of the hyperbola, one has to use the circular directrix related to ${\displaystyle F_{1}}$. This property should not be confused with the definition of a hyperbola with help of a directrix (line) below.
Hyperbola in Cartesian coordinates
Equation
If Cartesian coordinates are introduced such that the origin is the center of the hyperbola and the x-axis is the major axis, then the hyperbola is called east-west-opening and
the foci are the points ${\displaystyle F_{1}=(c,0),\ F_{2}=(-c,0)}$,
the vertices are ${\displaystyle V_{1}=(a,0),\ V_{2}=(-a,0)}$.
For an arbitrary point ${\displaystyle (x,y)}$ the distance to the focus ${\displaystyle (c,0)}$ is ${\displaystyle {\sqrt {(x-c)^{2}+y^{2}}}}$ and to the second focus ${\displaystyle {\sqrt {(x+c)^{2}+y^{2}}}}$. Hence the point ${\displaystyle (x,y)}$ is on the hyperbola if the following condition is fulfilled
${\displaystyle {\sqrt {(x-c)^{2}+y^{2}}}-{\sqrt {(x+c)^{2}+y^{2}}}=\pm 2a\ .}$
Remove the square roots by suitable squarings and use the relation ${\displaystyle b^{2}=c^{2}-a^{2}}$ to obtain the equation of the hyperbola:
• ${\displaystyle {\frac {x^{2}}{a^{2}}}-{\frac {y^{2}}{b^{2}}}=1\ .}$
This equation is called the canonical form of a hyperbola, because any hyperbola, regardless of its orientation relative to the Cartesian axes and regardless of the location of its center, can be transformed to this form by a change of variables, giving a hyperbola that is congruent to the original (see below).
The axes of symmetry or principal axes are the transverse axis (containing the segment of length 2a with endpoints at the vertices) and the conjugate axis (containing the segment of length 2b perpendicular to the transverse axis and with midpoint at the hyperbola’s center). As opposed to an ellipse, a hyperbola has only two vertices: ${\displaystyle (a,0),\;(-a,0)}$. The two points ${\displaystyle (0,b),\;(0,-b)}$ on the conjugate axis are not on the hyperbola.
It follows from the equation that the hyperbola is symmetric with respect to both of the coordinate axes and hence symmetric with respect to the origin.
Eccentricity
For a hyperbola in the above canonical form, the eccentricity is given by
${\displaystyle e={\sqrt {1+{\frac {b^{2}}{a^{2}}}}}.}$
Two hyperbolas are geometrically similar to each other – meaning that they have the same shape, so that one can be transformed into the other by rigid left and right movements, rotation, taking a mirror image, and scaling (magnification) – if and only if they have the same eccentricity.
Asymptotes
Hyperbola: semi-axes a,b, linear eccentricity c, semi latus rectum p
Hyperbola: 3 properties
Solving the equation (above) of the hyperbola for ${\displaystyle y}$ yields
${\displaystyle y=\pm {\frac {b}{a}}{\sqrt {x^{2}-a^{2}}}.}$
It follows from this that the hyperbola approaches the two lines
• ${\displaystyle y=\pm {\frac {b}{a}}x}$
for large values of ${\displaystyle |x|}$. These two lines intersect at the center (origin) and are called asymptotes of the hyperbola ${\displaystyle {\tfrac {x^{2}}{a^{2}}}-{\tfrac {y^{2}}{b^{2}}}=1\ .}$
With help of the figure one can see that
${\displaystyle {\color {blue}{(1)}}}$ The distance from a focus to either asymptote is ${\displaystyle b}$ (the semi-minor axis).
From the Hesse normal form ${\displaystyle {\tfrac {bx\pm ay}{\sqrt {a^{2}+b^{2}}}}=0}$ of the asymptotes and the equation of the hyperbola one gets:[6]
${\displaystyle {\color {magenta}{(2)}}}$ The product of the distances from a point on the hyperbola to both the asymptotes is the constant ${\displaystyle {\tfrac {a^{2}b^{2}}{a^{2}+b^{2}}}\ ,}$ which can also be written in terms of the eccentricity e as ${\displaystyle \left({\tfrac {b}{e}}\right)^{2}.}$
From the equation ${\displaystyle y=\pm {\frac {b}{a}}{\sqrt {x^{2}-a^{2}}}}$ of the hyperbola (above) one can derive:
${\displaystyle {\color {green}{(3)}}}$ The product of the slopes of lines from a point P to the two vertices is the constant ${\displaystyle b^{2}/a^{2}\ .}$
In addition, from (2) above it can be shown that[6]
${\displaystyle {\color {red}{(4)}}}$ The product of the distances from a point on the hyperbola to the asymptotes along lines parallel to the asymptotes is the constant ${\displaystyle {\tfrac {a^{2}+b^{2}}{4}}.}$
Semi-latus rectum
The length of the chord through one of the foci, perpendicular to the major axis of the hyperbola, is called the latus rectum. One half of it is the semi-latus rectum ${\displaystyle p}$. A calculation shows
• ${\displaystyle p={\frac {b^{2}}{a}}.}$
The semi-latus rectum ${\displaystyle p}$ may also be viewed as the radius of curvature of the osculating circles at the vertices.
Tangent
The simplest way to determine the equation of the tangent at a point ${\displaystyle (x_{0},y_{0})}$ is to implicitly differentiate the equation ${\displaystyle {\tfrac {x^{2}}{a^{2}}}-{\tfrac {y^{2}}{b^{2}}}=1}$ of the hyperbola. Denoting dy/dx as y′, this produces
${\displaystyle {\frac {2x}{a^{2}}}-{\frac {2yy'}{b^{2}}}=0\ \rightarrow \ y'={\frac {x}{y}}{\frac {b^{2}}{a^{2}}}\ \rightarrow \ y={\frac {x_{0}}{y_{0}}}{\frac {b^{2}}{a^{2}}}(x-x_{0})+y_{0}.}$
With respect to ${\displaystyle {\tfrac {x_{0}^{2}}{a^{2}}}-{\tfrac {y_{0}^{2}}{b^{2}}}=1}$, the equation of the tangent at point ${\displaystyle (x_{0},y_{0})}$ is,
• ${\displaystyle {\frac {x_{0}}{a^{2}}}x-{\frac {y_{0}}{b^{2}}}y=1.}$
A particular tangent line distinguishes the hyperbola from the other conic sections.[7] Let f be the distance from the vertex V (on both the hyperbola and its axis through the two foci) to the nearer focus. Then the distance, along a line perpendicular to that axis, from that focus to a point P on the hyperbola is greater than 2f. The tangent to the hyperbola at P intersects that axis at point Q at an angle ∠PQV of greater than 45°.
Rectangular hyperbola
In the case ${\displaystyle a=b}$ the hyperbola is called rectangular (or equilateral), because its asymptotes intersect rectangularly (i.e., are perpendicular). For this case, the linear eccentricity is ${\displaystyle c={\sqrt {2}}a}$, the eccentricity ${\displaystyle e={\sqrt {2}}}$ and the semi-latus rectum ${\displaystyle p=a}$.
Parametric representation with hyperbolic sine/cosine
Using the hyperbolic sine and cosine functions ${\displaystyle \cosh ,\sinh }$, a parametric representation of the hyperbola ${\displaystyle {\tfrac {x^{2}}{a^{2}}}-{\tfrac {y^{2}}{b^{2}}}=1}$ can be obtained, which is similar to the parametric representation of an ellipse:
• ${\displaystyle (\pm a\cosh t,b\sinh t),\,t\in \mathbb {R} \ ,}$
which satisfies the Cartesian equation because ${\displaystyle \cosh ^{2}t-\sinh ^{2}t=1.}$
Further parametric representations are given in the section Parametric equations below.
Here a = b = 1 giving the unit hyperbola in blue and its conjugate hyperbola in green, sharing the same red asymptotes.
Conjugate hyperbola
Exchange ${\displaystyle x}$ and ${\displaystyle y}$ to obtain the equation of the conjugate hyperbola (see diagram):
• ${\displaystyle {\frac {y^{2}}{a^{2}}}-{\frac {x^{2}}{b^{2}}}=1\ ,}$ also written as
${\displaystyle {\frac {x^{2}}{a^{2}}}-{\frac {y^{2}}{b^{2}}}=-1\ .}$
Hyperbola with equation y=A/x
Rotating the coordinate system in order to describe a rectangular hyperbola as graph of a function
Three rectangular hyperbolas ${\displaystyle y=A/x}$ with the coordinate axes as asymptotes
red: A=1, magenta: A=4; blue: A=9
If the xy-coordinate system is rotated about the origin by the angle ${\displaystyle -45^{\circ }}$ and new coordinates ${\displaystyle \xi ,\eta }$ are assigned, then ${\displaystyle x={\tfrac {\xi +\eta }{\sqrt {2}}},\;y={\tfrac {-\xi +\eta }{\sqrt {2}}}}$.
The rectangular hyperbola ${\displaystyle {\tfrac {x^{2}-y^{2}}{a^{2}}}=1}$ (whose semi-axes are equal) has the new equation ${\displaystyle {\tfrac {2\xi \eta }{a^{2}}}=1}$. Solving for ${\displaystyle \eta }$ yields ${\displaystyle \eta ={\tfrac {a^{2}/2}{\xi }}\ .}$
Thus, in an xy-coordinate system the graph of a function ${\displaystyle f:x\mapsto {\tfrac {A}{x}},\;A>0\;,}$ with equation
• ${\displaystyle y={\frac {A}{x}}\;,A>0\;,}$ is a rectangular hyperbola entirely in the first and third quadrants with
• the coordinate axes as asymptotes,
• the line ${\displaystyle y=x}$ as major axis ,
• the center ${\displaystyle (0,0)}$ and the semi-axis ${\displaystyle a=b={\sqrt {2A}}\;,}$
• the vertices ${\displaystyle ({\sqrt {A}},{\sqrt {A}}),(-{\sqrt {A}},-{\sqrt {A}})\;,}$
• the semi-latus rectum and radius of curvature at the vertices ${\displaystyle p=a={\sqrt {2A}}\;,}$
• the linear eccentricity ${\displaystyle c=2{\sqrt {A}}}$ and the eccentricity ${\displaystyle e={\sqrt {2}}\;,}$
• the tangent ${\displaystyle y=-{\tfrac {A}{x_{0}^{2}}}x+2{\tfrac {A}{x_{0}}}}$ at point ${\displaystyle (x_{0},A/x_{0})\;.}$
A rotation of the original hyperbola by ${\displaystyle +45^{\circ }}$ results in a rectangular hyperbola entirely in the second and fourth quadrants, with the same asymptotes, center, semi-latus rectum, radius of curvature at the vertices, linear eccentricity, and eccentricity as for the case of ${\displaystyle -45^{\circ }}$ rotation, with equation
• ${\displaystyle y={\frac {-A}{x}}\;,A>0\;,}$
• the semi-axes ${\displaystyle a=b={\sqrt {2A}}\;,}$
• the line ${\displaystyle y=-x}$ as major axis,
• the vertices ${\displaystyle (-{\sqrt {A}},{\sqrt {A}}),({\sqrt {A}},-{\sqrt {A}})\;.}$
Shifting the hyperbola with equation ${\displaystyle y={\frac {A}{x}},\ A\neq 0\ ,}$ so that the new center is ${\displaystyle (c_{0},d_{0})}$, yields the new equation
• ${\displaystyle y={\frac {A}{x-c_{0}}}+d_{0}\;,}$
and the new asymptotes are ${\displaystyle x=c_{0}}$ and ${\displaystyle y=d_{0}}$.
The shape parameters ${\displaystyle a,b,p,c,e}$ remain unchanged.
Definition of a hyperbola by the directrix property
Hyperbola: directrix property
Hyperbola: definition with directrix property
The two lines at distance ${\displaystyle d={\frac {a^{2}}{c}}}$ and parallel to the minor axis are called directrices of the hyperbola (see diagram).
• For an arbitrary point ${\displaystyle P}$ of the hyperbola the quotient of the distance to one focus and to the corresponding directrix (see diagram) is equal to the eccentricity:
${\displaystyle {\frac {|PF_{1}|}{|Pl_{1}|}}={\frac {|PF_{2}|}{|Pl_{2}|}}=e={\frac {c}{a}}\ .}$
The proof for the pair ${\displaystyle F_{1},l_{1}}$ follows from the fact that ${\displaystyle |PF_{1}|^{2}=(x-c)^{2}+y^{2},\ |Pl_{1}|^{2}=(x-{\tfrac {a^{2}}{c}})^{2}}$ and ${\displaystyle y^{2}={\tfrac {b^{2}}{a^{2}}}x^{2}-b^{2}}$ satisfy the equation
${\displaystyle |PF_{1}|^{2}-{\frac {c^{2}}{a^{2}}}|Pl_{1}|^{2}=0\ .}$
The second case is proven analogously.
Pencil of conics with a common vertex and common semi latus rectum
The inverse statement is also true and can be used to define a hyperbola (in a manner similar to the definition of a parabola):
• For any point ${\displaystyle F}$ (focus), any line ${\displaystyle l}$ (directrix) not through ${\displaystyle F}$ and any real number ${\displaystyle e}$ with ${\displaystyle e>1}$ the set of points (locus of points), for which the quotient of the distances to the point and to the line is ${\displaystyle e}$
${\displaystyle H=\{P\mid {\frac {|PF|}{|Pl|}}=e\}}$
is a hyperbola.
(The choice ${\displaystyle e=1}$ yields a parabola and if ${\displaystyle e<1}$ an ellipse.)
Proof
Let ${\displaystyle F=(f,0),\ e>0}$ and assume ${\displaystyle (0,0)}$ is a point on the curve. The directrix ${\displaystyle l}$ has equation ${\displaystyle x=-{\tfrac {f}{e}}}$. With ${\displaystyle P=(x,y)}$, the relation ${\displaystyle |PF|^{2}=e^{2}|Pl|^{2}}$ produces the equations
${\displaystyle (x-f)^{2}+y^{2}=e^{2}(x+{\tfrac {f}{e}})^{2}=(ex+f)^{2}}$ and ${\displaystyle x^{2}(e^{2}-1)+2xf(1+e)-y^{2}=0.}$
The substitution ${\displaystyle p=f(1+e)}$ yields
• ${\displaystyle x^{2}(e^{2}-1)+2px-y^{2}=0.}$
This is the equation of an ellipse (${\displaystyle e<1}$) or a parabola (${\displaystyle e=1}$) or a hyperbola (${\displaystyle e>1}$). All of these non-degenerate conics have, in common, the origin as a vertex (see diagram).
If ${\displaystyle e>1}$, introduce new parameters ${\displaystyle a,b}$ so that ${\displaystyle e^{2}-1={\tfrac {b^{2}}{a^{2}}},{\text{ and }}\ p={\tfrac {b^{2}}{a}}}$, and then the equation above becomes
${\displaystyle {\tfrac {(x+a)^{2}}{a^{2}}}-{\tfrac {y^{2}}{b^{2}}}=1\ ,}$
which is the equation of a hyperbola with center ${\displaystyle (-a,0)}$, the x-axis as major axis and the major/minor semi axis ${\displaystyle a,b}$.
Hyperbola as plane section of a cone
Hyperbola (red): two views of a cone and two Dandelin spheres d1, d2
The intersection of an upright double cone by a plane not through the vertex with slope greater than the slope of the lines on the cone is a hyperbola (see diagram: red curve). In order to prove the defining property of a hyperbola (see above) one uses two Dandelin spheres ${\displaystyle d_{1},d_{2}}$, which are spheres that touch the cone along circles ${\displaystyle c_{1}}$ , ${\displaystyle c_{2}}$ and the intersecting (hyperbola) plane at points ${\displaystyle F_{1}}$ and ${\displaystyle F_{2}}$. It turns out: ${\displaystyle F_{1},F_{2}}$ are the foci of the hyperbola.
1. Let ${\displaystyle P}$ be an arbitrary point of the intersection curve .
2. The generator (line) of the cone containing ${\displaystyle P}$ intersects circle ${\displaystyle c_{1}}$ at point ${\displaystyle A}$ and circle ${\displaystyle c_{2}}$ at a point ${\displaystyle B}$.
3. The line segments ${\displaystyle {\overline {PF_{1}}}}$ and ${\displaystyle {\overline {PA}}}$ are tangential to the sphere ${\displaystyle d_{1}}$ and, hence, are of equal length.
4. The line segments ${\displaystyle {\overline {PF_{2}}}}$ and ${\displaystyle {\overline {PB}}}$ are tangential to the sphere ${\displaystyle d_{2}}$ and, hence, are of equal length.
5. The result is: ${\displaystyle |PF_{1}|-|PF_{2}|=|PA|-|PB|=|AB|}$ is independent of the hyperbola point ${\displaystyle P}$.
The tangent bisects the angle between the lines to the foci
Hyperbola: the tangent bisects the lines through the foci
For a hyperbola the following statement is true:
• The tangent at a point ${\displaystyle P}$ bisects the angle between the lines ${\displaystyle {\overline {PF_{1}}},{\overline {PF_{2}}}}$.
Proof
Let ${\displaystyle L}$ be the point on the line ${\displaystyle {\overline {PF_{2}}}}$ with the distance ${\displaystyle 2a}$ to the focus ${\displaystyle F_{2}}$ (see diagram, ${\displaystyle a}$ is the semi major axis of the hyperbola). Line ${\displaystyle w}$ is the bisector of the angle between the lines ${\displaystyle {\overline {PF_{1}}},{\overline {PF_{2}}}}$. In order to prove that ${\displaystyle w}$ is the tangent line at point ${\displaystyle P}$, one checks that any point ${\displaystyle Q}$ on line ${\displaystyle w}$ which is different from ${\displaystyle P}$ cannot be on the hyperbola. Hence ${\displaystyle w}$ has only point ${\displaystyle P}$ in common with the hyperbola and is, therefore, the tangent at point ${\displaystyle P}$.
From the diagram and the triangle inequality one recognizes that ${\displaystyle |QF_{2}|<|LF_{2}|+|QL|=2a+|QF_{1}|}$ holds, which means: ${\displaystyle |QF_{2}|-|QF_{1}|<2a}$. But if ${\displaystyle Q}$ is a point of the hyperbola, the difference should be ${\displaystyle 2a}$.
Midpoints of parallel chords
Hyperbola: the midpoints of parallel chords lie on a line.
Hyperbola: the midpoint of a chord is the midpoint of the corresponding chord of the asymptotes.
• The midpoints of parallel chords of a hyperbola lie on a line through the center (see diagram).
The points of any chord may lie on different branches of the hyperbola.
The proof of the property on midpoints is best done for the hyperbola ${\displaystyle y=1/x}$. Because any hyperbola is an affine image of the hyperbola ${\displaystyle y=1/x}$ (see section below) and an affine transformation preserves parallelism and midpoints of line segments, the property is true for all hyperbolas:
For two points ${\displaystyle P=(x_{1},{\tfrac {1}{x_{1}}}),\ Q=(x_{2},{\tfrac {1}{x_{2}}})}$ of the hyperbola ${\displaystyle y=1/x}$
• the midpoint of the chord is ${\displaystyle M=({\tfrac {x_{1}+x_{2}}{2}},\cdots )=\cdots ={\tfrac {x_{1}+x_{2}}{2}}\;(1,{\tfrac {1}{x_{1}x_{2}}})\ ;}$
• the slope of the chord is ${\displaystyle {\frac {{\tfrac {1}{x_{2}}}-{\tfrac {1}{x_{1}}}}{x_{2}-x_{1}}}=\cdots =-{\tfrac {1}{x_{1}x_{2}}}\ .}$
For parallel chords the slope is constant and the midpoints of the parallel chords lie on the line ${\displaystyle y={\tfrac {1}{x_{1}x_{2}}}\;x\ .}$
Consequence: for any pair of points ${\displaystyle P,Q}$ of a chord there exists a skew reflection with an axis (set of fixed points) passing through the center of the hyperbola, which exchanges the points ${\displaystyle P,Q}$ and leaves the hyperbola (as a whole) fixed. A skew reflection is a generalization of an ordinary reflection across a line ${\displaystyle m}$, where all point-image pairs are on a line perpendicular to ${\displaystyle m}$.
Because a skew reflection leaves the hyperbola fixed, the pair of asymptotes is fixed, too. Hence the midpoint ${\displaystyle M}$ of a chord ${\displaystyle PQ}$ divides the related line segment ${\displaystyle {\overline {P}}\,{\overline {Q}}}$ between the asymptotes into halves, too. This means that ${\displaystyle |P{\overline {P}}|=|Q{\overline {Q}}|}$. This property can be used for the construction of further points ${\displaystyle Q}$ of the hyperbola if a point ${\displaystyle P}$ and the asymptotes are given.
If the chord degenerates into a tangent, then the touching point divides the line segment between the asymptotes in two halves.
Steiner generation of a hyperbola
Hyperbola: Steiner generation
Hyperbola y=1/x: Steiner generation
The following method to construct single points of a hyperbola relies on the Steiner generation of a non degenerate conic section:
• Given two pencils ${\displaystyle B(U),B(V)}$ of lines at two points ${\displaystyle U,V}$ (all lines containing ${\displaystyle U}$ and ${\displaystyle V}$, respectively) and a projective but not perspective mapping ${\displaystyle \pi }$ of ${\displaystyle B(U)}$ onto ${\displaystyle B(V)}$, then the intersection points of corresponding lines form a non-degenerate projective conic section.
For the generation of points of the hyperbola ${\displaystyle {\tfrac {x^{2}}{a^{2}}}-{\tfrac {y^{2}}{b^{2}}}=1}$ one uses the pencils at the vertices ${\displaystyle V_{1},V_{2}}$. Let ${\displaystyle P=(x_{0},y_{0})}$ be a point of the hyperbola and ${\displaystyle A=(a,y_{0}),B=(x_{0},0)}$. The line segment ${\displaystyle {\overline {BP}}}$ is divided into n equally-spaced segments and this division is projected parallel with the diagonal ${\displaystyle AB}$ as direction onto the line segment ${\displaystyle {\overline {AP}}}$ (see diagram). The parallel projection is part of the projective mapping between the pencils at ${\displaystyle V_{1}}$ and ${\displaystyle V_{2}}$ needed. The intersection points of any two related lines ${\displaystyle S_{1}A_{i}}$ and ${\displaystyle S_{2}B_{i}}$ are points of the uniquely defined hyperbola.
Remark: The subdivision could be extended beyond the points ${\displaystyle A}$ and ${\displaystyle B}$ in order to get more points, but the determination of the intersection points would become more inaccurate. A better idea is extending the points already constructed by symmetry (see animation).
Remark:
1. The Steiner generation exists for ellipses and parabolas, too.
2. The Steiner generation is sometimes called a parallelogram method because one can use other points rather than the vertices, which starts with a parallelogram instead of a rectangle.
Inscribed angles for hyperbolas y=a/(x−b)+c and the 3-point-form
Hyperbola: inscribed angle theorem
A hyperbola with equation ${\displaystyle y={\tfrac {a}{x-b}}+c,\ a\neq 0}$ is uniquely determined by three points ${\displaystyle (x_{1},y_{1}),\;(x_{2},y_{2}),\;(x_{3},y_{3})}$ with different x- and y-coordinates. A simple way to determine the shape parameters ${\displaystyle a,b,c}$ uses the inscribed angle theorem for hyperbolas:
• In order to measure an angle between two lines with equations ${\displaystyle y=m_{1}x+d_{1},\ y=m_{2}x+d_{2}\ ,m_{1},m_{2}\neq 0}$ in this context one uses the quotient
${\displaystyle {\frac {m_{1}}{m_{2}}}\ .}$
Analogous to the inscribed angle theorem for circles one gets the
Inscribed angle theorem for hyperbolas:,:[8][9]
For four points ${\displaystyle P_{i}=(x_{i},y_{i}),\ i=1,2,3,4,\ x_{i}\neq x_{k},y_{i}\neq y_{k},i\neq k}$ (see diagram) the following statement is true:
The four points are on a hyperbola with equation ${\displaystyle y={\tfrac {a}{x-b}}+c}$ if and only if the angles at ${\displaystyle P_{3}}$ and ${\displaystyle P_{4}}$ are equal in the sense of the measurement above. That means if
${\displaystyle {\frac {(y_{4}-y_{1})}{(x_{4}-x_{1})}}{\frac {(x_{4}-x_{2})}{(y_{4}-y_{2})}}={\frac {(y_{3}-y_{1})}{(x_{3}-x_{1})}}{\frac {(x_{3}-x_{2})}{(y_{3}-y_{2})}}}$
(Proof: straightforward calculation. If the points are on a hyperbola, one can assume the hyperbola's equation is ${\displaystyle y=a/x}$.)
A consequence of the inscribed angle theorem for hyperbolas is the
3-point-form of a hyperbola's equation:
The equation of the hyperbola determined by 3 points ${\displaystyle P_{i}=(x_{i},y_{i}),\ i=1,2,3,\ x_{i}\neq x_{k},y_{i}\neq y_{k},i\neq k}$ is the solution of the equation
${\displaystyle {\frac {({\color {red}y}-y_{1})}{({\color {green}x}-x_{1})}}{\frac {({\color {green}x}-x_{2})}{({\color {red}y}-y_{2})}}={\frac {(y_{3}-y_{1})}{(x_{3}-x_{1})}}{\frac {(x_{3}-x_{2})}{(y_{3}-y_{2})}}}$
for ${\displaystyle {\color {red}y}}$.
Orthogonal tangents - orthoptic
Hyperbola with its orthoptic (magenta)
For a hyperbola ${\displaystyle {\frac {x^{2}}{a^{2}}}-{\frac {y^{2}}{b^{2}}}=1,\,a>b}$ the intersection points of orthogonal tangents lie on the circle ${\displaystyle x^{2}+y^{2}=a^{2}-b^{2}}$.
This circle is called the orthoptic of the given hyperbola.
The tangents may belong to points on different branches of the hyperbola.
In case of ${\displaystyle a\leq b}$ there are no pairs of orthogonal tangents.
Pole-polar relation for a hyperbola
Hyperbola: pole-polar relation
Any hyperbola can be described in a suitable coordinate system by an equation ${\displaystyle {\tfrac {x^{2}}{a^{2}}}-{\tfrac {y^{2}}{b^{2}}}=1}$. The equation of the tangent at a point ${\displaystyle P_{0}=(x_{0},y_{0})}$ of the hyperbola is ${\displaystyle {\tfrac {x_{0}x}{a^{2}}}-{\tfrac {y_{0}y}{b^{2}}}=1.}$ If one allows point ${\displaystyle P_{0}=(x_{0},y_{0})}$ to be an arbitrary point different from the origin, then
• point ${\displaystyle P_{0}=(x_{0},y_{0})\neq (0,0)}$ is mapped onto the line ${\displaystyle {\frac {x_{0}x}{a^{2}}}-{\frac {y_{0}y}{b^{2}}}=1}$, not through the center of the hyperbola.
This relation between points and lines is a bijection.
The inverse function maps
• line ${\displaystyle y=mx+d,\ d\neq 0}$ onto the point ${\displaystyle \left(-{\frac {ma^{2}}{d}},-{\frac {b^{2}}{d}}\right)}$ and
line ${\displaystyle x=c,\ c\neq 0}$ onto the point ${\displaystyle \left({\frac {a^{2}}{c}},0\right)\ .}$
Such a relation between points and lines generated by a conic is called pole-polar relation or just polarity. The pole is the point, the polar the line. See Pole and polar.
By calculation one checks the following properties of the pole-polar relation of the hyperbola:
• For a point (pole) on the hyperbola the polar is the tangent at this point (see diagram: ${\displaystyle P_{1},\ p_{1}}$).
• For a pole ${\displaystyle P}$ outside the hyperbola the intersection points of its polar with the hyperbola are the tangency points of the two tangents passing ${\displaystyle P}$ (see diagram: ${\displaystyle P_{2},\ p_{2},\ P_{3},\ p_{3}}$).
• For a point within the hyperbola the polar has no point with the hyperbola in common. (see diagram: ${\displaystyle P_{4},\ p_{4}}$).
Remarks:
1. The intersection point of two polars (for example: ${\displaystyle p_{2},p_{3}}$) is the pole of the line through their poles (here: ${\displaystyle P_{2},P_{3}}$).
2. The foci ${\displaystyle (c,0),}$ and ${\displaystyle (-c,0)}$ respectively and the directrices ${\displaystyle x={\tfrac {a^{2}}{c}}}$ and ${\displaystyle x=-{\tfrac {a^{2}}{c}}}$ respectively belong to pairs of pole and polar.
Pole-polar relations exist for ellipses and parabolas, too.
Hyperbola as an affine image of the unit hyperbola x²-y²=1
Hyperbola as an affine image of the unit hyperbola
Another definition of a hyperbola uses affine transformations:
• Any hyperbola is the affine image of the unit hyperbola with equation ${\displaystyle x^{2}-y^{2}=1}$.
An affine transformation of the Euclidean plane has the form ${\displaystyle {\vec {x}}\to {\vec {f}}_{0}+A{\vec {x}}}$, where ${\displaystyle A}$ is a regular matrix (its determinant is not 0) and ${\displaystyle {\vec {f}}_{0}}$ is an arbitrary vector. If ${\displaystyle {\vec {f}}_{1},{\vec {f}}_{2}}$ are the column vectors of the matrix ${\displaystyle A}$, the unit hyperbola ${\displaystyle (\pm \cosh(t),\sinh(t)),t\in \mathbb {R} ,}$ is mapped onto the hyperbola
• ${\displaystyle {\vec {x}}={\vec {p}}(t)={\vec {f}}_{0}\pm {\vec {f}}_{1}\cosh t+{\vec {f}}_{2}\sinh t\ .}$
${\displaystyle {\vec {f}}_{0}}$ is the center, ${\displaystyle {\vec {f}}_{0}+{\vec {f}}_{1}}$ a point of the hyperbola and ${\displaystyle {\vec {f}}_{2}}$ a tangent vector at this point. In general the vectors ${\displaystyle {\vec {f}}_{1},{\vec {f}}_{2}}$ are not perpendicular. That means, in general ${\displaystyle {\vec {f}}_{0}\pm {\vec {f}}_{1}}$ are not the vertices of the hyperbola. But ${\displaystyle {\vec {f}}_{1}\pm {\vec {f}}_{2}}$ point into the directions of the asymptotes.
The tangent vector at point ${\displaystyle {\vec {p}}(t)}$ is
${\displaystyle {\vec {p}}'(t)={\vec {f}}_{1}\sinh t+{\vec {f}}_{2}\cosh t\ .}$
Because at a vertex the tangent is perpendicular to the major axis of the hyperbola one gets the parameter ${\displaystyle t_{0}}$ of a vertex from the equation
${\displaystyle {\vec {p}}'(t)\cdot ({\vec {p}}(t)-{\vec {f}}_{0})=({\vec {f}}_{1}\sinh t+{\vec {f}}_{2}\cosh t)\cdot ({\vec {f}}_{1}\cosh t+{\vec {f}}_{2}\sinh t)=0}$
and hence from
${\displaystyle \coth(2t_{0})=-{\tfrac {{\vec {f}}_{1}^{\,2}+{\vec {f}}_{2}^{\,2}}{2{\vec {f}}_{1}\cdot {\vec {f}}_{2}}}\ ,}$
which yields
• ${\displaystyle t_{0}={\tfrac {1}{4}}\ln {\tfrac {({\vec {f}}_{1}-{\vec {f}}_{2})^{2}}{({\vec {f}}_{1}+{\vec {f}}_{2})^{2}}}.}$
(The formulae ${\displaystyle \cosh ^{2}x+\sinh ^{2}x=\cosh 2x,\ 2\sinh x\cosh x=\sinh 2x,\ \operatorname {arcoth} x={\tfrac {1}{2}}\ln {\tfrac {x+1}{x-1}}}$ were used.)
The two vertices of the hyperbola are ${\displaystyle {\vec {f}}_{0}\pm ({\vec {f}}_{1}\cosh t_{0}+{\vec {f}}_{2}\sinh t_{0}).}$
The advantage of this definition is that one gets a simple parametric representation of an arbitrary hyperbola, even in the space, if the vectors ${\displaystyle {\vec {f}}_{0},{\vec {f}}_{1},{\vec {f}}_{2}}$ are vectors of the Euclidean space.
Hyperbola as an affine image of the hyperbola y=1/x
Hyperbola as affine image of y=1/x
Because the unit hyperbola ${\displaystyle x^{2}-y^{2}=1}$ is affinely equivalent to the hyperbola ${\displaystyle y=1/x}$, an arbitrary hyperbola can be considered as the affine image (see previous section) of the hyperbola ${\displaystyle y=1/x\ :}$
• ${\displaystyle {\vec {x}}={\vec {p}}(t)={\vec {f}}_{0}+{\vec {f}}_{1}t+{\vec {f}}_{2}{\tfrac {1}{t}},\quad t\neq 0\ .}$
${\displaystyle M:{\vec {f}}_{0}}$ is the center of the hyperbola, the vectors ${\displaystyle {\vec {f}}_{1},{\vec {f}}_{2}}$ have the directions of the asymptotes and ${\displaystyle {\vec {f}}_{1}+{\vec {f}}_{2}}$ is a point of the hyperbola. The tangent vector is
${\displaystyle {\vec {p}}'(t)={\vec {f}}_{1}-{\vec {f}}_{2}{\tfrac {1}{t^{2}}}.}$
At a vertex the tangent is perpendicular to the major axis. Hence
${\displaystyle {\vec {p}}'(t)\cdot ({\vec {p}}(t)-{\vec {f}}_{0})=({\vec {f}}_{1}-{\vec {f}}_{2}{\tfrac {1}{t^{2}}})\cdot ({\vec {f}}_{1}t+{\vec {f}}_{2}{\tfrac {1}{t}})={\vec {f}}_{1}^{2}t-{\vec {f}}_{2}^{2}{\tfrac {1}{t^{3}}}=0.}$
and the parameter of a vertex is
• ${\displaystyle t_{0}=\pm {\sqrt[{4}]{\tfrac {{\vec {f}}_{2}^{2}}{{\vec {f}}_{1}^{2}}}}.}$
${\displaystyle |{\vec {f}}_{1}|=|{\vec {f}}_{2}|}$ is equivalent to ${\displaystyle t_{0}=\pm 1}$ and ${\displaystyle {\vec {f}}_{0}\pm ({\vec {f}}_{1}+{\vec {f}}_{2})}$ are the vertices of the hyperbola.
The following properties of a hyperbola are easily proven using the representation of a hyperbola introduced in this section.
Tangent construction
Tangent construction: asymptotes and P given → tangent
The tangent vector can be rewritten by factorization:
${\displaystyle {\vec {p}}'(t)={\tfrac {1}{t}}({\vec {f}}_{1}t-{\vec {f}}_{2}{\tfrac {1}{t}})\ .}$
This means that
• the diagonal ${\displaystyle AB}$ of the parallelogram ${\displaystyle M:\ {\vec {f}}_{0},\ A={\vec {f}}_{0}+{\vec {f}}_{1}t,\ B:\ {\vec {f}}_{0}+{\vec {f}}_{2}{\tfrac {1}{t}},\ P:\ {\vec {f}}_{0}+{\vec {f}}_{1}t+{\vec {f}}_{2}{\tfrac {1}{t}}}$ is parallel to the tangent at the hyperbola point ${\displaystyle P}$ (see diagram).
This property provides a way to construct the tangent at a point on the hyperbola.
This property of a hyperbola is an affine version of the 3-point-degeneration of Pascal's theorem.[10]
Area of the grey parallelogram
The area of the grey parallelogram MAPB in the above diagram is
${\displaystyle {\text{Area}}=|\det(t{\vec {f}}_{1},{\tfrac {1}{t}}{\vec {f}}_{2})|=|\det({\vec {f}}_{1},{\vec {f}}_{2})|=\cdots ={\frac {a^{2}+b^{2}}{4}}}$
and hence independent of point P. The last equation follows from a calculation for the case, where P is a vertex and the hyperbola in its canonical form ${\displaystyle {\tfrac {x^{2}}{a^{2}}}-{\tfrac {y^{2}}{b^{2}}}=1\ .}$
Point construction
Point construction: asymptotes and P1 are given → P2
For a hyperbola with parametric representation ${\displaystyle {\vec {x}}={\vec {p}}(t)={\vec {f}}_{1}t+{\vec {f}}_{2}{\tfrac {1}{t}}}$ (for simplicity the center is the origin) the following is true:
• For any two points ${\displaystyle P_{1}:\ {\vec {f}}_{1}t_{1}+{\vec {f}}_{2}{\tfrac {1}{t_{1}}},\ P_{2}:\ {\vec {f}}_{1}t_{2}+{\vec {f}}_{2}{\tfrac {1}{t_{2}}}}$ the points
${\displaystyle A:\ {\vec {a}}={\vec {f}}_{1}t_{1}+{\vec {f}}_{2}{\tfrac {1}{t_{2}}},\ B:\ {\vec {b}}={\vec {f}}_{1}t_{2}+{\vec {f}}_{2}{\tfrac {1}{t_{1}}}}$
are collinear with the center of the hyperbola (see diagram).
The simple proof is a consequence of the equation ${\displaystyle {\tfrac {1}{t_{1}}}{\vec {a}}={\tfrac {1}{t_{2}}}{\vec {b}}}$.
This property provides a possibility to construct points of a hyperbola if the asymptotes and one point are given.
This property of a hyperbola is an affine version of the 4-point-degeneration of Pascal's theorem.[11]
Tangent-asymptotes-triangle
Hyperbola: tangent-asymptotes-triangle
For simplicity the center of the hyperbola may be the origin and the vectors ${\displaystyle {\vec {f}}_{1},{\vec {f}}_{2}}$ have equal length. If the last assumption is not fulfilled one can first apply a parameter transformation (see above) in order to make the assumption true. Hence ${\displaystyle \pm ({\vec {f}}_{1}+{\vec {f}}_{2})}$ are the vertices, ${\displaystyle \pm ({\vec {f}}_{1}-{\vec {f}}_{2})}$ span the minor axis and one gets ${\displaystyle |{\vec {f}}_{1}+{\vec {f}}_{2}|=a}$ and ${\displaystyle |{\vec {f}}_{1}-{\vec {f}}_{2}|=b}$.
For the intersection points of the tangent at point ${\displaystyle {\vec {p}}(t_{0})={\vec {f}}_{1}t_{0}+{\vec {f}}_{2}{\tfrac {1}{t_{0}}}}$ with the asymptotes one gets the points
${\displaystyle C=2t_{0}{\vec {f}}_{1},\ D={\tfrac {2}{t_{0}}}{\vec {f}}_{2}.}$
The area of the triangle ${\displaystyle M,C,D}$ can be calculated by a 2x2-determinant:
${\displaystyle A={\tfrac {1}{2}}|\det(2t_{0}{\vec {f}}_{1},{\tfrac {2}{t_{0}}}{\vec {f}}_{2})|=2|\det({\vec {f}}_{1},{\vec {f}}_{2})|}$
(see rules for determinants). ${\displaystyle |\det({\vec {f}}_{1},{\vec {f}}_{2})|}$ is the area of the rhombus generated by ${\displaystyle {\vec {f}}_{1},{\vec {f}}_{2}}$. The area of a rhombus is equal to one half of the product of its diagonals. The diagonals are the semi-axes ${\displaystyle a,b}$ of the hyperbola. Hence:
• The area of the triangle ${\displaystyle MCD}$ is independent of the point of the hyperbola: ${\displaystyle A=ab.}$
Polar coordinates
Hyperbola: Polar coordinates with pole = focus
Hyperbola: Polar coordinates with pole = center
pole = focus:
The polar coordinates used most commonly for the hyperbola are defined relative to the Cartesian coordinate system that has its origin in a focus and its x-axis pointing towards the origin of the "canonical coordinate system" as illustrated in the first diagram.
In this case the angle ${\displaystyle \varphi }$ is called true anomaly.
Relative to this coordinate system one has that
• ${\displaystyle r={\frac {p}{1\mp e\cos \varphi }},\quad p={\tfrac {b^{2}}{a}}}$
and
${\displaystyle -\arccos \left(-{\frac {1}{e}}\right)<\varphi <\arccos \left(-{\frac {1}{e}}\right).}$
pole = center:
With polar coordinates relative to the "canonical coordinate system" (see second diagram) one has that
• ${\displaystyle r={\frac {b}{\sqrt {e^{2}\cos ^{2}\varphi -1}}}.\,}$
For the right branch of the hyperbola the range of ${\displaystyle \varphi }$ is
${\displaystyle -\arccos \left({\frac {1}{e}}\right)<\varphi <\arccos \left({\frac {1}{e}}\right).}$
Parametric equations
A hyperbola with equation ${\displaystyle {\tfrac {x^{2}}{a^{2}}}-{\tfrac {y^{2}}{b^{2}}}=1}$ can be described by several parametric equations:
1: ${\displaystyle \left\{{\begin{matrix}\quad \;x\,=\,\pm a\cosh t\\y\,=\,b\sinh t\end{matrix}}\right.\quad ,\ t\in \mathbb {R} \ .}$
2: ${\displaystyle \left\{{\begin{matrix}\quad \ x\,=\,\pm a\,{\tfrac {t^{2}+1}{2t}}\\y\,=\,b\,{\tfrac {t^{2}-1}{2t}}\end{matrix}}\right.\quad ,\ t>0\ .}$ (rational representation)
3: ${\displaystyle \left\{{\begin{matrix}\quad \ x\,=\,{\frac {a}{\cos t}}=a\sec t\\y\,=\,\pm b\tan t\end{matrix}}\right.\ ,\quad 0\leq t<2\pi ;\;t\neq {\frac {\pi }{2}};\;t\neq {\frac {3}{2}}\pi \ .}$
4: Tangent slope as parameter:
A parametric representation, which uses the slope ${\displaystyle m}$ of the tangent at a point of the hyperbola can be obtained analogously to the ellipse case: Replace in the ellipse case ${\displaystyle b^{2}}$ by ${\displaystyle -b^{2}}$ and use formulae for the hyperbolic functions. One gets
${\displaystyle {\vec {c}}_{\pm }(m)=\left(-{\frac {ma^{2}}{\pm {\sqrt {m^{2}a^{2}-b^{2}}}}}\;,\;{\frac {-b^{2}}{\pm {\sqrt {m^{2}a^{2}-b^{2}}}}}\right)\ ,\ |m|>b/a\ .}$
${\displaystyle {\vec {c}}_{-}}$ is the upper and ${\displaystyle {\vec {c}}_{+}}$ the lower half of the hyperbola. The points with vertical tangents (vertices ${\displaystyle (\pm a,0)}$) are not covered by the representation.
The equation of the tangent at point ${\displaystyle {\vec {c}}_{\pm }(m)}$ is
${\displaystyle y=mx\pm {\sqrt {m^{2}a^{2}-b^{2}}}.}$
This description of the tangents of a hyperbola is an essential tool for the determination of the orthoptic of a hyperbola.
Other mathematical definitions
Reciprocation of a circle
The reciprocation of a circle B in a circle C always yields a conic section such as a hyperbola. The process of "reciprocation in a circle C" consists of replacing every line and point in a geometrical figure with their corresponding pole and polar, respectively. The pole of a line is the inversion of its closest point to the circle C, whereas the polar of a point is the converse, namely, a line whose closest point to C is the inversion of the point.
The eccentricity of the conic section obtained by reciprocation is the ratio of the distances between the two circles' centers to the radius r of reciprocation circle C. If B and C represent the points at the centers of the corresponding circles, then
${\displaystyle e={\frac {\overline {BC}}{r}}.}$
Since the eccentricity of a hyperbola is always greater than one, the center B must lie outside of the reciprocating circle C.
This definition implies that the hyperbola is both the locus of the poles of the tangent lines to the circle B, as well as the envelope of the polar lines of the points on B. Conversely, the circle B is the envelope of polars of points on the hyperbola, and the locus of poles of tangent lines to the hyperbola. Two tangent lines to B have no (finite) poles because they pass through the center C of the reciprocation circle C; the polars of the corresponding tangent points on B are the asymptotes of the hyperbola. The two branches of the hyperbola correspond to the two parts of the circle B that are separated by these tangent points.
A hyperbola can also be defined as a second-degree equation in the Cartesian coordinates (x, y) in the plane,
${\displaystyle A_{xx}x^{2}+2A_{xy}xy+A_{yy}y^{2}+2B_{x}x+2B_{y}y+C=0,}$
provided that the constants Axx, Axy, Ayy, Bx, By, and C satisfy the determinant condition
${\displaystyle D:={\begin{vmatrix}A_{xx}&A_{xy}\\A_{xy}&A_{yy}\end{vmatrix}}<0.\,}$
This determinant is conventionally called the discriminant of the conic section.[12]
A special case of a hyperbola—the degenerate hyperbola consisting of two intersecting lines—occurs when another determinant is zero:
${\displaystyle \Delta :={\begin{vmatrix}A_{xx}&A_{xy}&B_{x}\\A_{xy}&A_{yy}&B_{y}\\B_{x}&B_{y}&C\end{vmatrix}}=0.}$
This determinant Δ is sometimes called the discriminant of the conic section.[13]
Given the above general parametrization of the hyperbola in Cartesian coordinates, the eccentricity can be found using the formula in Conic section#Eccentricity in terms of parameters of the quadratic form.
The center (xc, yc) of the hyperbola may be determined from the formulae
${\displaystyle x_{c}=-{\frac {1}{D}}{\begin{vmatrix}B_{x}&A_{xy}\\B_{y}&A_{yy}\end{vmatrix}};}$
${\displaystyle y_{c}=-{\frac {1}{D}}{\begin{vmatrix}A_{xx}&B_{x}\\A_{xy}&B_{y}\end{vmatrix}}.}$
In terms of new coordinates, ξ = xxc and η = yyc, the defining equation of the hyperbola can be written
${\displaystyle A_{xx}\xi ^{2}+2A_{xy}\xi \eta +A_{yy}\eta ^{2}+{\frac {\Delta }{D}}=0.}$
The principal axes of the hyperbola make an angle φ with the positive x-axis that is given by
${\displaystyle \tan 2\varphi ={\frac {2A_{xy}}{A_{xx}-A_{yy}}}.}$
Rotating the coordinate axes so that the x-axis is aligned with the transverse axis brings the equation into its canonical form
${\displaystyle {\frac {x^{2}}{a^{2}}}-{\frac {y^{2}}{b^{2}}}=1.}$
The major and minor semiaxes a and b are defined by the equations
${\displaystyle a^{2}=-{\frac {\Delta }{\lambda _{1}D}}=-{\frac {\Delta }{\lambda _{1}^{2}\lambda _{2}}},}$
${\displaystyle b^{2}=-{\frac {\Delta }{\lambda _{2}D}}=-{\frac {\Delta }{\lambda _{1}\lambda _{2}^{2}}},}$
where λ1 and λ2 are the roots of the quadratic equation
${\displaystyle \lambda ^{2}-\left(A_{xx}+A_{yy}\right)\lambda +D=0.}$
For comparison, the corresponding equation for a degenerate hyperbola (consisting of two intersecting lines) is
${\displaystyle {\frac {x^{2}}{a^{2}}}-{\frac {y^{2}}{b^{2}}}=0.}$
The tangent line to a given point (x0, y0) on the hyperbola is defined by the equation
${\displaystyle Ex+Fy+G=0}$
where E, F and G are defined by
${\displaystyle E=A_{xx}x_{0}+A_{xy}y_{0}+B_{x},}$
${\displaystyle F=A_{xy}x_{0}+A_{yy}y_{0}+B_{y},}$
${\displaystyle G=B_{x}x_{0}+B_{y}y_{0}+C.}$
The normal line to the hyperbola at the same point is given by the equation
${\displaystyle F(x-x_{0})-E(y-y_{0})=0.}$
The normal line is perpendicular to the tangent line, and both pass through the same point (x0, y0).
From the equation
${\displaystyle {\frac {x^{2}}{a^{2}}}-{\frac {y^{2}}{b^{2}}}=1,\qquad 0
the left focus is ${\displaystyle (-ae,0)}$ and the right focus is ${\displaystyle (ae,0),}$ where e is the eccentricity. Denote the distances from a point (x, y) to the left and right foci as ${\displaystyle r_{1}\,\!}$ and ${\displaystyle r_{2}.\,\!}$ For a point on the right branch,
${\displaystyle r_{1}-r_{2}=2a,\,\!}$
and for a point on the left branch,
${\displaystyle r_{2}-r_{1}=2a.\,\!}$
This can be proved as follows:
If (x,y) is a point on the hyperbola the distance to the left focal point is
${\displaystyle r_{1}^{2}=(x+ae)^{2}+y^{2}=x^{2}+2xae+a^{2}e^{2}+(x^{2}-a^{2})(e^{2}-1)=(ex+a)^{2}.}$
To the right focal point the distance is
${\displaystyle r_{2}^{2}=(x-ae)^{2}+y^{2}=x^{2}-2xae+a^{2}e^{2}+(x^{2}-a^{2})(e^{2}-1)=(ex-a)^{2}.}$
If (x,y) is a point on the right branch of the hyperbola then ${\displaystyle ex>a\,\!}$ and
${\displaystyle r_{1}=ex+a,\,\!}$
${\displaystyle r_{2}=ex-a.\,\!}$
Subtracting these equations one gets
${\displaystyle r_{1}-r_{2}=2a.\,\!}$
If (x,y) is a point on the left branch of the hyperbola then ${\displaystyle ex<-a\,\!}$ and
${\displaystyle r_{1}=-ex-a,\,\!}$
${\displaystyle r_{2}=-ex+a.\,\!}$
Subtracting these equations one gets
${\displaystyle r_{2}-r_{1}=2a.\,\!}$
Conic section analysis of the hyperbolic appearance of circles
Central projection of circles on a sphere: The center O of projection is inside the sphere, the image plane is red.
As images of the circles one gets a circle (magenta), ellipses, hyperbolas and lines. The special case of a parabola does not appear in this example.
(If center O were on the sphere, all images of the circles would be circles or lines; see stereographic projection).
Besides providing a uniform description of circles, ellipses, parabolas, and hyperbolas, conic sections can also be understood as a natural model of the geometry of perspective in the case where the scene being viewed consists of circles, or more generally an ellipse. The viewer is typically a camera or the human eye and the image of the scene a central projection onto an image plane, i.e., all projection rays pass a fixed point O, the center. The lens plane is a plane parallel to the image plane at the lens O.
The image of a circle c is
a) a circle, if circle c is in a special position, for example parallel to the image plane and others (see stereographic projection),
b) an ellipse, if c has no point with the lens plane in common,
c) a parabola, if c has one point with the lens plane in common and
d) a hyperbola, if c has two points with the lens plane in common.
(Special positions where the circle plane contains point O are omitted.)
These results can be understood if one recognizes that the projection process can be seen in two steps: 1) circle c and point O generate a cone which is 2) cut by the image plane, in order to generate the image.
One sees a hyperbola whenever catching sight of a portion of a circle cut by one's lens plane. The inability to see very much of the arms of the visible branch, combined with the complete absence of the second branch, makes it virtually impossible for the human visual system to recognize the connection with hyperbolas.
Derived curves
Sinusoidal spirals: equilateral hyperbola (n = −2), line (n = −1), parabola (n = −1/2), cardioid (n = 1/2), circle (n = 1) and lemniscate of Bernoulli (n = 2), where rn = −1n cos in polar coordinates and their equivalents in rectangular coordinates.
Several other curves can be derived from the hyperbola by inversion, the so-called inverse curves of the hyperbola. If the center of inversion is chosen as the hyperbola's own center, the inverse curve is the lemniscate of Bernoulli; the lemniscate is also the envelope of circles centered on a rectangular hyperbola and passing through the origin. If the center of inversion is chosen at a focus or a vertex of the hyperbola, the resulting inverse curves are a limaçon or a strophoid, respectively.
Elliptic coordinates
A family of confocal hyperbolas is the basis of the system of elliptic coordinates in two dimensions. These hyperbolas are described by the equation
${\displaystyle \left({\frac {x}{c\cos \theta }}\right)^{2}-\left({\frac {y}{c\sin \theta }}\right)^{2}=1}$
where the foci are located at a distance c from the origin on the x-axis, and where θ is the angle of the asymptotes with the x-axis. Every hyperbola in this family is orthogonal to every ellipse that shares the same foci. This orthogonality may be shown by a conformal map of the Cartesian coordinate system w = z + 1/z, where z= x + iy are the original Cartesian coordinates, and w=u + iv are those after the transformation.
Other orthogonal two-dimensional coordinate systems involving hyperbolas may be obtained by other conformal mappings. For example, the mapping w = z2 transforms the Cartesian coordinate system into two families of orthogonal hyperbolas.
Other properties of hyperbolas
• The following are concurrent: (1) a circle passing through the hyperbola's foci and centered at the hyperbola's center; (2) either of the lines that are tangent to the hyperbola at the vertices; and (3) either of the asymptotes of the hyperbola.[14][15]
• The following are also concurrent: (1) the circle that is centered at the hyperbola's center and that passes through the hyperbola's vertices; (2) either directrix; and (3) either of the asymptotes.[15]
Hyperbolic functions
A ray through the unit hyperbola ${\displaystyle x^{2}\ -\ y^{2}\ =\ 1}$ in the point ${\displaystyle (\cosh \,a,\,\sinh \,a)}$, where ${\displaystyle a}$ is twice the area between the ray, the hyperbola, and the ${\displaystyle x}$-axis. For points on the hyperbola below the ${\displaystyle x}$-axis, the area is considered negative.
Just as the trigonometric functions are defined in terms of the unit circle, so also the hyperbolic functions are defined in terms of the unit hyperbola, as shown in this diagram.
Applications
Hyperbolas as declination lines on a sundial
Sundials
Hyperbolas may be seen in many sundials. On any given day, the sun revolves in a circle on the celestial sphere, and its rays striking the point on a sundial traces out a cone of light. The intersection of this cone with the horizontal plane of the ground forms a conic section. At most populated latitudes and at most times of the year, this conic section is a hyperbola. In practical terms, the shadow of the tip of a pole traces out a hyperbola on the ground over the course of a day (this path is called the declination line). The shape of this hyperbola varies with the geographical latitude and with the time of the year, since those factors affect the cone of the sun's rays relative to the horizon. The collection of such hyperbolas for a whole year at a given location was called a pelekinon by the Greeks, since it resembles a double-bladed axe.
Multilateration
A hyperbola is the basis for solving multilateration problems, the task of locating a point from the differences in its distances to given points — or, equivalently, the difference in arrival times of synchronized signals between the point and the given points. Such problems are important in navigation, particularly on water; a ship can locate its position from the difference in arrival times of signals from a LORAN or GPS transmitters. Conversely, a homing beacon or any transmitter can be located by comparing the arrival times of its signals at two separate receiving stations; such techniques may be used to track objects and people. In particular, the set of possible positions of a point that has a distance difference of 2a from two given points is a hyperbola of vertex separation 2a whose foci are the two given points.
Path followed by a particle
The path followed by any particle in the classical Kepler problem is a conic section. In particular, if the total energy E of the particle is greater than zero (i.e., if the particle is unbound), the path of such a particle is a hyperbola. This property is useful in studying atomic and sub-atomic forces by scattering high-energy particles; for example, the Rutherford experiment demonstrated the existence of an atomic nucleus by examining the scattering of alpha particles from gold atoms. If the short-range nuclear interactions are ignored, the atomic nucleus and the alpha particle interact only by a repulsive Coulomb force, which satisfies the inverse square law requirement for a Kepler problem.
Korteweg–de Vries equation
The hyperbolic trig function ${\displaystyle \operatorname {sech} \,x}$ appears as one solution to the Korteweg–de Vries equation which describes the motion of a soliton wave in a canal.
Angle trisection
Trisecting an angle (AOB) using a hyperbola of eccentricity 2 (yellow curve)
As shown first by Apollonius of Perga, a hyperbola can be used to trisect any angle, a well studied problem of geometry. Given an angle, first draw a circle centered at its vertex O, which intersects the sides of the angle at points A and B. Next draw the line segment with endpoints A and B and its perpendicular bisector ${\displaystyle \ell }$. Construct a hyperbola of eccentricity e=2 with ${\displaystyle \ell }$ as directrix and B as a focus. Let P be the intersection (upper) of the hyperbola with the circle. Angle POB trisects angle AOB.
To prove this, reflect the line segment OP about the line ${\displaystyle \ell }$ obtaining the point P' as the image of P. Segment AP' has the same length as segment BP due to the reflection, while segment PP' has the same length as segment BP due to the eccentricity of the hyperbola. As OA, OP', OP and OB are all radii of the same circle (and so, have the same length), the triangles OAP', OPP' and OPB are all congruent. Therefore, the angle has been trisected, since 3×POB = AOB.[16]
Efficient portfolio frontier
In portfolio theory, the locus of mean-variance efficient portfolios (called the efficient frontier) is the upper half of the east-opening branch of a hyperbola drawn with the portfolio return's standard deviation plotted horizontally and its expected value plotted vertically; according to this theory, all rational investors would choose a portfolio characterized by some point on this locus.
Hyperbolas as plane sections of quadrics
Hyperbolas appear as plane sections of the following quadrics:
Notes
1. ^ Heath, Sir Thomas Little (1896), "Chapter I. The discovery of conic sections. Menaechmus", Apollonius of Perga: Treatise on Conic Sections with Introductions Including an Essay on Earlier History on the Subject, Cambridge University Press, pp. xvii–xxx.
2. ^ Boyer, Carl B.; Merzbach, Uta C. (2011), A History of Mathematics, Wiley, p. 73, ISBN 9780470630563, It was Apollonius (possibly following up a suggestion of Archimedes) who introduced the names "ellipse" and "hyperbola" in connection with these curves.
3. ^ Eves, Howard (1963), A Survey of Geometry (Vol. One), Allyn and Bacon, pp. 30–31
4. ^ Apostol, Tom M.; Mnatsakanian, Mamikon A. (2012), New Horizons in Geometry, The Dolciani Mathematical Expositions #47, The Mathematical Association of America, p. 251, ISBN 978-0-88385-354-2
5. ^ The German term for this circle is Leitkreis which can be translated as "Director circle", but that term has a different meaning in the English literature (see Director circle).
6. ^ a b Mitchell, Douglas W., "A property of hyperbolas and their asymptotes", Mathematical Gazette 96, July 2012, 299–301.
7. ^ J. W. Downs, Practical Conic Sections, Dover Publ., 2003 (orig. 1993): p. 26.
8. ^ E. Hartmann: Lecture Note 'Planar Circle Geometries', an Introduction to Möbius-, Laguerre- and Minkowski Planes, p. 93
9. ^ W. Benz: Vorlesungen über Geomerie der Algebren, Springer (1973)
10. ^
11. ^
12. ^ Fanchi, John R. (2006), Math refresher for scientists and engineers, John Wiley and Sons, pp. 44–45, ISBN 0-471-75715-2, Section 3.2, page 45
13. ^ Korn, Granino A. and Korn, Theresa M. Mathematical Handbook for Scientists and Engineers: Definitions, Theorems, and Formulas for Reference and Review, Dover Publ., second edition, 2000: p. 40.
14. ^ "Hyperbola". Mathafou.free.fr. Retrieved 26 August 2018.
15. ^ a b [1]
16. ^ This construction is due to Pappus of Alexandria (circa 300 A.D.) and the proof comes from Kazarinoff (1970, pg. 62).
References
• Kazarinoff, Nicholas D. (2003), Ruler and the Round, Mineola, N.Y.: Dover, ISBN 0-486-42515-0 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 380, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.929305374622345, "perplexity": 437.90129563069127}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-39/segments/1537267165261.94/warc/CC-MAIN-20180926140948-20180926161348-00182.warc.gz"} |
https://www.aimsciences.org/article/doi/10.3934/amc.2020132 | # American Institute of Mathematical Sciences
doi: 10.3934/amc.2020132
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## Polynomial-time plaintext recovery attacks on the IKKR code-based cryptosystems
Temasek Laboratories, National University of Singapore, 5A Engineering Drive 1, #09-02, Singapore 117411, Singapore
* Corresponding author: T. S. C. Lau
Received July 2020 Revised November 2020 Early access January 2021
Recently, Ivanov et al. proposed a new approach to construct code-based cryptosystems, namely the ${\sf IKKR}$ public-key encryptions (PKE) in the International Workshop on Code-Based Cryptography (CBCrypto 2020) [9]. Unlike the usual construction in code-based encryption schemes which has restrictions on the Hamming weight of the error introduced into the ciphertext, the ${\sf IKKR}$ approach allows error vectors of arbitrary weight being introduced into the ciphertext. Using this new approach, Ivanov et al. constructed two cryptosystems, namely the modified and the upgraded ${\sf IKKR}$-PKE. This paper aims to discuss the practical security of the ${\sf IKKR}$-PKE. In particular, we describe the weaknesses in the design of the public key used in the ${\sf IKKR}$-PKE. We exploit such weaknesses and propose two attacks to recover the plaintext in the ${\sf IKKR}$-PKE. The approach of our first attack is similar to the LCKN attack [12], whilst our second attack is more efficient than the LCKN attack. Our experimental results show that we can recover the plaintext from a given ciphertext in less than 176 milliseconds for schemes based on random Goppa codes and BCH codes.
Citation: Terry Shue Chien Lau, Chik How Tan. Polynomial-time plaintext recovery attacks on the IKKR code-based cryptosystems. Advances in Mathematics of Communications, doi: 10.3934/amc.2020132
##### References:
[1] M. Baldi and F. Chiaraluce, Cryptanalysis of a new instance of McEliece cryptosystem based on QC-LDPC codes, in IEEE International Symposium on Information Theory (ISIT 2007), 2007, 2591–2595. Google Scholar [2] S. Barg, Some New NP-Complete Coding Problems, Problems Inform. Transmission, 30 (1994), 209-214. Google Scholar [3] A. Becker, A. Joux, A. May and A. Meurer, Decoding random binary linear codes in 2n/20: How 1 + 1 = 0 improves Information Set Decoding, in Advances in Cryptology—EUROCRYPT 2012, Lecture Notes in Comput. Sci., vol. 7237, Springer, Heidelberg, 2012,520–536. doi: 10.1007/978-3-642-29011-4_31. Google Scholar [4] E. Berlekamp, R. McEliece and H. C. A. van Tilborg, On the inherent intractability of certain coding problems, IEEE Trans. Inform. Theory, 24 (1978), 384-386. doi: 10.1109/tit.1978.1055873. Google Scholar [5] D. J. Bernstein, T. Lange and C. Peters, Smaller decoding exponents: Ball-collision decoding, in Advances in Cryptology (CRYPTO 2011), Lecture Notes in Comput. Sci., vol. 6841, Springer, Heidelberg, 2011,743–760. doi: 10.1007/978-3-642-22792-9_42. Google Scholar [6] C. T. Gueye, J. B. Klamti and S. Hirose, Generalization of BJMM-ISD using May-Ozerov nearest neighbor algorithm over an arbitrary finite field $\mathbb{F}_q$, in Codes, Cryptology and Information Security, Lecture Notes in Comput. Sci., vol. 10194, Springer, Cham, 2017, 96–109. doi: 10.1007/978-3-319-55589-8. Google Scholar [7] S. Hirose, May-Ozerov algorithm for nearest-neighbor problem over $\mathbb{F}_q$ and its application to information set decoding, in International Conference for Information Technology and Communications, 2016,115–126. Google Scholar [8] C. Interlando, K. Khathuria, N. Rohrer, J. Rosenthal and V. Weger, Generalization of the ball-collision algorithm, Journal of Algebra Combinatorics Discrete Structures and Applications, 7 (2020), 195-207. doi: 10.13069/jacodesmath.729477. Google Scholar [9] F. Ivanov, G. Kabatiansky, E. Krouk and N. Rumenko, A new code-based cryptosystem, in International Workshop on Code-Based Cryptography (CBCrypto 2020), 2020, 41–49. doi: 10.1007/978-3-030-54074-6_3. Google Scholar [10] F. Ivanov, G. Kabatiansky, E. Krouk and N. Rumenko, A new code-based cryptosystem, International Workshop on Code-Based Cryptography (CBCrypto 2020), 2020, https://drive.google.com/open?id=1NvEShYAu_6RkL2nmooydvP1yWxaPTiXt. Google Scholar [11] P. J. Lee and E. F. Brickell, An observation on the security of McEliece's public-key cryptosystem, in Advances in cryptology—EUROCRYPT '88 (Davos, 1988), Lecture Notes in Comput. Sci., vol. 330, Springer, Berlin, 1988,275–280. doi: 10.1007/3-540-45961-8_25. Google Scholar [12] Y. Lee, J. Cho, Y. S. Kim and J. S. No, Cryptanalysis of the Ivanov-Kabatiansky-Krouk-Rumenko Cryptosystems, IEEE Communications Letters, 24 (2020), 2678-2681. doi: 10.1109/LCOMM.2020.3019054. Google Scholar [13] J. S. Leon, A probabilistic algorithm for computing minimum weights of large error-correcting codes, IEEE Transactions on Information Theory, 34 (1988), 1354-1359. doi: 10.1109/18.21270. Google Scholar [14] A. May and I. Ozerov, On computing nearest neighbors with applications to decoding of binary linear codes, in Advances in Cryptology—EUROCRYPT 2015, Part I, Lecture Notes in Comput. Sci., vol. 9056, Springer, Heidelberg, 2015,203–228. doi: 10.1007/978-3-662-46800-5_9. Google Scholar [15] R. J. McEliece, A Public-Key Cryptosystem Based on Algebraic Coding Theory, DSN Progress Report, Jet Propulsion Laboratory, Pasadena, Technical report, 1978. Google Scholar [16] R. Niebuhr, E. Persichetti, P.-L. Cayrel, S. Bulygin and J. Buchmann, On lower bounds for information set decoding over $\mathbb{F}_q$ and on the effect of partial knowledge, Int. J. Inf. Coding Theory, 4 (2017), 47-78. doi: 10.1504/IJICOT.2017.081458. Google Scholar [17] C. Peters, Information-set decoding for linear codes over , in Post-quantum Cryptography, Lecture Notes in Comput. Sci., vol. 6061, Springer, Berlin, 2010, 81–94. doi: 10.1007/978-3-642-12929-2_7. Google Scholar [18] E. Prange, The use of information sets in decoding cyclic codes, IRE Transactions on Information Theory, 8 (1962), 5-9. doi: 10.1109/tit.1962.1057777. Google Scholar [19] V. M. Sidelnikov and S. O. Shestakov, On an encoding system constructed on the basis of generalized Reed-Solomon codes, Diskret. Mat., 4 (1992), 57-63. Google Scholar [20] J. Stern, A method for finding codewords of small weight, in Coding Theory and Applications, Lecture Notes in Comput. Sci., vol. 388, Springer, New York, 1989,106–113. doi: 10.1007/BFb0019850. Google Scholar
show all references
##### References:
[1] M. Baldi and F. Chiaraluce, Cryptanalysis of a new instance of McEliece cryptosystem based on QC-LDPC codes, in IEEE International Symposium on Information Theory (ISIT 2007), 2007, 2591–2595. Google Scholar [2] S. Barg, Some New NP-Complete Coding Problems, Problems Inform. Transmission, 30 (1994), 209-214. Google Scholar [3] A. Becker, A. Joux, A. May and A. Meurer, Decoding random binary linear codes in 2n/20: How 1 + 1 = 0 improves Information Set Decoding, in Advances in Cryptology—EUROCRYPT 2012, Lecture Notes in Comput. Sci., vol. 7237, Springer, Heidelberg, 2012,520–536. doi: 10.1007/978-3-642-29011-4_31. Google Scholar [4] E. Berlekamp, R. McEliece and H. C. A. van Tilborg, On the inherent intractability of certain coding problems, IEEE Trans. Inform. Theory, 24 (1978), 384-386. doi: 10.1109/tit.1978.1055873. Google Scholar [5] D. J. Bernstein, T. Lange and C. Peters, Smaller decoding exponents: Ball-collision decoding, in Advances in Cryptology (CRYPTO 2011), Lecture Notes in Comput. Sci., vol. 6841, Springer, Heidelberg, 2011,743–760. doi: 10.1007/978-3-642-22792-9_42. Google Scholar [6] C. T. Gueye, J. B. Klamti and S. Hirose, Generalization of BJMM-ISD using May-Ozerov nearest neighbor algorithm over an arbitrary finite field $\mathbb{F}_q$, in Codes, Cryptology and Information Security, Lecture Notes in Comput. Sci., vol. 10194, Springer, Cham, 2017, 96–109. doi: 10.1007/978-3-319-55589-8. Google Scholar [7] S. Hirose, May-Ozerov algorithm for nearest-neighbor problem over $\mathbb{F}_q$ and its application to information set decoding, in International Conference for Information Technology and Communications, 2016,115–126. Google Scholar [8] C. Interlando, K. Khathuria, N. Rohrer, J. Rosenthal and V. Weger, Generalization of the ball-collision algorithm, Journal of Algebra Combinatorics Discrete Structures and Applications, 7 (2020), 195-207. doi: 10.13069/jacodesmath.729477. Google Scholar [9] F. Ivanov, G. Kabatiansky, E. Krouk and N. Rumenko, A new code-based cryptosystem, in International Workshop on Code-Based Cryptography (CBCrypto 2020), 2020, 41–49. doi: 10.1007/978-3-030-54074-6_3. Google Scholar [10] F. Ivanov, G. Kabatiansky, E. Krouk and N. Rumenko, A new code-based cryptosystem, International Workshop on Code-Based Cryptography (CBCrypto 2020), 2020, https://drive.google.com/open?id=1NvEShYAu_6RkL2nmooydvP1yWxaPTiXt. Google Scholar [11] P. J. Lee and E. F. Brickell, An observation on the security of McEliece's public-key cryptosystem, in Advances in cryptology—EUROCRYPT '88 (Davos, 1988), Lecture Notes in Comput. Sci., vol. 330, Springer, Berlin, 1988,275–280. doi: 10.1007/3-540-45961-8_25. Google Scholar [12] Y. Lee, J. Cho, Y. S. Kim and J. S. No, Cryptanalysis of the Ivanov-Kabatiansky-Krouk-Rumenko Cryptosystems, IEEE Communications Letters, 24 (2020), 2678-2681. doi: 10.1109/LCOMM.2020.3019054. Google Scholar [13] J. S. Leon, A probabilistic algorithm for computing minimum weights of large error-correcting codes, IEEE Transactions on Information Theory, 34 (1988), 1354-1359. doi: 10.1109/18.21270. Google Scholar [14] A. May and I. Ozerov, On computing nearest neighbors with applications to decoding of binary linear codes, in Advances in Cryptology—EUROCRYPT 2015, Part I, Lecture Notes in Comput. Sci., vol. 9056, Springer, Heidelberg, 2015,203–228. doi: 10.1007/978-3-662-46800-5_9. Google Scholar [15] R. J. McEliece, A Public-Key Cryptosystem Based on Algebraic Coding Theory, DSN Progress Report, Jet Propulsion Laboratory, Pasadena, Technical report, 1978. Google Scholar [16] R. Niebuhr, E. Persichetti, P.-L. Cayrel, S. Bulygin and J. Buchmann, On lower bounds for information set decoding over $\mathbb{F}_q$ and on the effect of partial knowledge, Int. J. Inf. Coding Theory, 4 (2017), 47-78. doi: 10.1504/IJICOT.2017.081458. Google Scholar [17] C. Peters, Information-set decoding for linear codes over , in Post-quantum Cryptography, Lecture Notes in Comput. Sci., vol. 6061, Springer, Berlin, 2010, 81–94. doi: 10.1007/978-3-642-12929-2_7. Google Scholar [18] E. Prange, The use of information sets in decoding cyclic codes, IRE Transactions on Information Theory, 8 (1962), 5-9. doi: 10.1109/tit.1962.1057777. Google Scholar [19] V. M. Sidelnikov and S. O. Shestakov, On an encoding system constructed on the basis of generalized Reed-Solomon codes, Diskret. Mat., 4 (1992), 57-63. Google Scholar [20] J. Stern, A method for finding codewords of small weight, in Coding Theory and Applications, Lecture Notes in Comput. Sci., vol. 388, Springer, New York, 1989,106–113. doi: 10.1007/BFb0019850. Google Scholar
Differences between the modified and the upgraded ${\sf IKKR}$-PKE
PKE ${\sf MDF}$.${\sf IKKR}$ ${\sf UGD}$.${\sf IKKR}$ $\mathcal{C}$ must be decodable any random code $E_{\sf pub}$ $WD[UG+P]M$ $Q[UG + T]M$ $\text{rk} (E_{\sf pub})$ $=t< n-k$ $=n-k$ ${\sf Decrypt} (\mathit{\boldsymbol{m}})$ requires decoding does not require decoding
PKE ${\sf MDF}$.${\sf IKKR}$ ${\sf UGD}$.${\sf IKKR}$ $\mathcal{C}$ must be decodable any random code $E_{\sf pub}$ $WD[UG+P]M$ $Q[UG + T]M$ $\text{rk} (E_{\sf pub})$ $=t< n-k$ $=n-k$ ${\sf Decrypt} (\mathit{\boldsymbol{m}})$ requires decoding does not require decoding
Parameters proposed for the ${\sf MDF}$.${\sf IKKR}$-PKE and the ${\sf UGD}$.${\sf IKKR}$-PKE
Instance Code $(q,n,k,t)$ ${\sf pk}$ size Security ${\sf MDF}$.${\sf IKKR}$-Goppa Goppa $(2,256,128,16)$ 12,288 KB 80-bit ${\sf UGD}$.${\sf IKKR}$-BCH BCH $(2,121,71,9)$ 2,513 KB 56-bit
Instance Code $(q,n,k,t)$ ${\sf pk}$ size Security ${\sf MDF}$.${\sf IKKR}$-Goppa Goppa $(2,256,128,16)$ 12,288 KB 80-bit ${\sf UGD}$.${\sf IKKR}$-BCH BCH $(2,121,71,9)$ 2,513 KB 56-bit
Simulation results of our plaintext recovery attacks
Instance Security Plaintext Recovery Attack $t_{\sf PRA}$ ${\sf MDF}$.${\sf IKKR}$-Goppa 80-bit Algorithm 2 176 ms Algorithm 3 103 ms ${\sf UGD}$.${\sf IKKR}$-BCH 56-bit Algorithm 2 120 ms Algorithm 3 77 ms
Instance Security Plaintext Recovery Attack $t_{\sf PRA}$ ${\sf MDF}$.${\sf IKKR}$-Goppa 80-bit Algorithm 2 176 ms Algorithm 3 103 ms ${\sf UGD}$.${\sf IKKR}$-BCH 56-bit Algorithm 2 120 ms Algorithm 3 77 ms
[1] Jintai Ding, Sihem Mesnager, Lih-Chung Wang. Letters for post-quantum cryptography standard evaluation. Advances in Mathematics of Communications, 2020, 14 (1) : i-i. doi: 10.3934/amc.2020012 [2] Pedro Branco. A post-quantum UC-commitment scheme in the global random oracle model from code-based assumptions. Advances in Mathematics of Communications, 2021, 15 (1) : 113-130. doi: 10.3934/amc.2020046 [3] Gérard Maze, Chris Monico, Joachim Rosenthal. Public key cryptography based on semigroup actions. Advances in Mathematics of Communications, 2007, 1 (4) : 489-507. doi: 10.3934/amc.2007.1.489 [4] Gerhard Frey. Relations between arithmetic geometry and public key cryptography. Advances in Mathematics of Communications, 2010, 4 (2) : 281-305. doi: 10.3934/amc.2010.4.281 [5] Felipe Cabarcas, Daniel Cabarcas, John Baena. Efficient public-key operation in multivariate schemes. Advances in Mathematics of Communications, 2019, 13 (2) : 343-371. doi: 10.3934/amc.2019023 [6] Anton Stolbunov. Constructing public-key cryptographic schemes based on class group action on a set of isogenous elliptic curves. Advances in Mathematics of Communications, 2010, 4 (2) : 215-235. doi: 10.3934/amc.2010.4.215 [7] Florian Luca, Igor E. Shparlinski. On finite fields for pairing based cryptography. Advances in Mathematics of Communications, 2007, 1 (3) : 281-286. doi: 10.3934/amc.2007.1.281 [8] Yu-Chi Chen. Security analysis of public key encryption with filtered equality test. Advances in Mathematics of Communications, 2021 doi: 10.3934/amc.2021053 [9] Lidong Chen, Dustin Moody. New mission and opportunity for mathematics researchers: Cryptography in the quantum era. Advances in Mathematics of Communications, 2020, 14 (1) : 161-169. doi: 10.3934/amc.2020013 [10] Joan-Josep Climent, Elisa Gorla, Joachim Rosenthal. Cryptanalysis of the CFVZ cryptosystem. Advances in Mathematics of Communications, 2007, 1 (1) : 1-11. doi: 10.3934/amc.2007.1.1 [11] Sikhar Patranabis, Debdeep Mukhopadhyay. Identity-based key aggregate cryptosystem from multilinear maps. Advances in Mathematics of Communications, 2019, 13 (4) : 759-778. doi: 10.3934/amc.2019044 [12] Rainer Steinwandt, Adriana Suárez Corona. Cryptanalysis of a 2-party key establishment based on a semigroup action problem. Advances in Mathematics of Communications, 2011, 5 (1) : 87-92. doi: 10.3934/amc.2011.5.87 [13] Angsuman Das, Avishek Adhikari, Kouichi Sakurai. Plaintext checkable encryption with designated checker. Advances in Mathematics of Communications, 2015, 9 (1) : 37-53. doi: 10.3934/amc.2015.9.37 [14] Giacomo Micheli. Cryptanalysis of a noncommutative key exchange protocol. Advances in Mathematics of Communications, 2015, 9 (2) : 247-253. doi: 10.3934/amc.2015.9.247 [15] Diego F. Aranha, Ricardo Dahab, Julio López, Leonardo B. Oliveira. Efficient implementation of elliptic curve cryptography in wireless sensors. Advances in Mathematics of Communications, 2010, 4 (2) : 169-187. doi: 10.3934/amc.2010.4.169 [16] Andreas Klein. How to say yes, no and maybe with visual cryptography. Advances in Mathematics of Communications, 2008, 2 (3) : 249-259. doi: 10.3934/amc.2008.2.249 [17] Anna-Lena Horlemann-Trautmann, Violetta Weger. Information set decoding in the Lee metric with applications to cryptography. Advances in Mathematics of Communications, 2021, 15 (4) : 677-699. doi: 10.3934/amc.2020089 [18] Mohamed Baouch, Juan Antonio López-Ramos, Blas Torrecillas, Reto Schnyder. An active attack on a distributed Group Key Exchange system. Advances in Mathematics of Communications, 2017, 11 (4) : 715-717. doi: 10.3934/amc.2017052 [19] Joan-Josep Climent, Juan Antonio López-Ramos. Public key protocols over the ring $E_{p}^{(m)}$. Advances in Mathematics of Communications, 2016, 10 (4) : 861-870. doi: 10.3934/amc.2016046 [20] Shixiong Wang, Longjiang Qu, Chao Li, Shaojing Fu, Hao Chen. Finding small solutions of the equation $\mathit{{Bx-Ay = z}}$ and its applications to cryptanalysis of the RSA cryptosystem. Advances in Mathematics of Communications, 2021, 15 (3) : 441-469. doi: 10.3934/amc.2020076
2020 Impact Factor: 0.935 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.48224955797195435, "perplexity": 5066.261303724492}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320300533.72/warc/CC-MAIN-20220117091246-20220117121246-00462.warc.gz"} |
https://infoscience.epfl.ch/record/195360 | ## The nu MSM and muon to electron conversion experiments
We review briefly the different constraints on the three right-handed neutrinos of the nu MSM, an extension of the Standard Model that can explain baryon asymmetry, dark matter and neutrino masses. We include in the discussion the proposed experiments on muon to electron conversion Mu2e (Carey et al., Mu2e Collaboration, 2012), COMET and PRISM (Hungerford, COMET Collaboration, AIP Conf Proc 1182:694, 2009; Cui et al., COMET Collaboration, 2012). We find that the expected sensitivity of these experiments is weaker by about two orders of magnitude than the constraints coming from successful baryogenesis.
Published in:
Hyperfine Interactions, 214, 1-3, 5-11
Presented at:
5th International Symposium on Symmetries in Subatomic Physics (SSP), Groningen, NETHERLANDS, JUN 18-22, 2012
Year:
2013
Publisher:
Dordrecht, Springer
ISSN:
0304-3843
Keywords:
Laboratories: | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9547184705734253, "perplexity": 6717.129900930033}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-17/segments/1524125945624.76/warc/CC-MAIN-20180422154522-20180422174522-00169.warc.gz"} |
http://vipupak.by/faxhkzujf/caption-latex-options.html | - OR -
# Caption latex options
Captioning Figures. The mandatory and optional arguments consist of: width Specifies the width of the tabular* environment. A simple example follows, as usual there is no real limit with respect to complexity. 3 September 19, 2000 fancybox. Open an example of different captioning options available in LaTeX in Overleaf. Because of how LaTeX deals sensibly with logical structure, it will automatically keep track of the numbering of figures, so you do not need to include this within the caption text. Adding a caption to a floating environment (for images, figure provides a floating 10 Sep 2019 This package supports typesetting of sub-captions (by using the the The options for the subcaption package are the same ones as for the 2The pictures were taken with permission from the LATEX Companion[1] examples LaTeX2e[1994/12/01] caption-rus. tex[2008/04/06 v3. Examples for a single figure, and multiple figures next to each other, using the subfigure environment. You must set nusepackage[options]falgorithm2egbefore nbeginfdocumentgcommand. Nov 01, 2017 · Using lists in LaTeX is pretty straightforward and doesn't require you do add any additional packages. 7. So, if you're only targeting LaTeX, you could always use the LaTeX command for the figure too. Asaresult,whenyouhavesuchaneed,youshould defineformat inkable() aseither“html”or“latex”. How can I position figures and tables where I want them with LaTeX? LaTeX uses specific rules to place floats (figures and tables). Click/tap on Closed captions on the left side, and change the caption font, caption background, and dim window content settings to what you want. Please note: Many document classes already have build-in options and commands for customizing captions. Ask Question Asked 9 years, 2 months ago. We’ll show also how to center the title position, as well as, how to change the title font size and color. The most frequently asked questions Walter Schmidt Abstract This article tries to answer the three most popular questions regarding font selection in L A TEX. Heading 9; Block Text; Footnote Text; Definition Term; Definition; Caption; Table Caption 30 Jan 2019 caption = "Demographic profile of survey participants" and markup Changing option to qwraps2_markup = "latex" solved the problem that the 26 Nov 2011 So I am submitting some of my work to a journal, and the journal has certain stipulations for their format style. Jump to navigation Jump to search. To make them floating objects use ‘:float’ with one of the following options: ‘sideways’, ‘multicolumn’, ‘t’, and ‘nil’. Watch Caption Submission, Bondage - 100 Pics at xHamster. Actually none of these options work in Beamer as far as I can tell. The package provides extensive facilities, both for constructing headers and footers, and for controlling their use (for example, at times when LaTeX would automatically change the heading style in use). 1. With the LaTeX package caption you can change the properties (such as font family) of the captions of floats (tables and figures). On example is the caption labels LaTeX Guides and Resources · Supplemental Files and Research Data To create equation captions that meet the Chicago style manual guidelines and and use the Table Tools—Layout options to vertically center the caption and have it Use the Captions Settings dialog box to determine the content and formatting of captions you generate. You can see the current condition that fonts of text and image caption of are different. We can simply add the following command to the figure environment -. I get really into the stories and I just don't get that anymore with writing my captions. In LaTeX, a caption is usually associated with a float (like table, figure, ). The options for the subcaption package are the same ones as for the caption package, but specify settings which are used for sub-captions additionally. trimclipand \adjustbox/adjustbox but no additional keys and macros. Possible options include basic, striped, bordered, hover, condensed and responsive. In LaTeX, you can use a command such as \sf in the \caption command to put the text of the caption in a sans-serif font, but LaTeX still uses the default font for the label, so you get an ugly mixture like this ("Figure 1" in Times and the rest of the caption in Helvetica): Captioning Figures. If the draft option is given, the functionality of the package is enabled and otherwise the e ect of the package is disabled. The location of the caption is traditionally underneath the float. Latex Standard Environments LaTeX provides a number of different paragraph-making environments. . 3 How LATEX Works To use LATEX, you first create a plain ASCII text file with any text editor. Using pdflatex several graphics formats are supported: pdf, png and jpg. To use it, we include the following line in the preamble: \usepackage{graphicx} The command \graphicspath{ {. I've enjoyed writing these stories for a long time but as of late I just have no drive to write them. You could use this package to better separate the captions of floats from the body text. Balloon prices on Amazon vary by size, material, and quantity; many of the balloons Amazon sells come in multipacks. To float an image without specifying a caption, set the ‘:float’ attribute to one of the following: ‘t’ For a standard ‘figure’ environment; used by default whenever an image has a caption. the pgf package is used for clip operations and the pgfmath pacakge is used to parse length arguments. I expect that the option will trigger problems with tikz versions The above produces Arabic numerals for the subfigure captions and upper case Roman numerals for the figure caption: If your document has chapters, then the caption labels would be something like 1. Add a Title Edit a Title Remove a Title Add, Edit or Remove a Caption Add a Title Click the plot to select it. If you are using pdfLaTeX, it appends. It also contains commands for shadow, double and oval frames. There are a number of options you can specify to control this process, the most important of which is which LaTeX program you want to use for typesetting. If typeset above, its distance to frame is now identical to the setting used for captions of tables (one half of the baseline). Adding a caption to a floating environment (for images, figure provides a floating environment) is very easy. Analogous to the type option of the caption package, the subtype option sets the sub-type of the box or environment (so \caption will typeset a sub-caption instead of an ordinary one), places a proper hyperlink anchor (non-starred variant only), executes options associated with the < LaTeX. Fixed a bug causing a caption to be inserted into a generated LaTeX code even if no relevant option was selected. T his page shows how to customize the captions for figures, tables, subfigures and subtables in LaTeX. 2/21 The optional argument [placement] determines where LaTeX will try to place your table. I'm Marti, in some places known as awruk88. Making Figures in LaTeX. What you do with these placement permissions is to list which of the options you wish to make available to LaTeX. Can GeoGebra do that? Thanks. ‚e option timestampis used to include a time stamp in the footer of each page. This is a good option if you have problems with the text. \label{table:1} If you need to refer the table within your document, set a label with this command. The argument where specifies the allowed locations for the table. The package pgf/tikz can be used to create beautiful graphics, especially diagrams in LaTeX. $x^{2}$), and choose from a list of most commonly used Greek letters and operators, just clicking on the little box displayed at the end of the Caption field. Hi forum friends, I wonder how to change the caption font of images in margin (sf) to Calibri-Light, which is also the font of the main text. A short introduction to LaTeX (with some focus on the differences between the old LaTeX 2. Alex < LaTeX. sty is generated that defines the complete title matter. 1h The caption package in Внутри стандартных классов LaTeX'а подписи не получили заслуженного где аргументом font options являются перечисленные через запятую опции. Supported options are: scale=number magnifies the figure by number over its natural size. As a result a link to this caption (e. Version 1. Jan 25, 2019 · To fix this use the caption package with center as the option. Extra options in HTML & LaTeX tables editors are now remembered between browser sessions. It seems that Docx2LaTeX only generates a caption at the bottom of the table. For this purpose the package sidecap defines the new environments SCfigure and SCtable. This causes floats to always appear after their placement in the document. In most cases you do not need to set it. 09 and current standard LaTeX2e) is given in the following document: LaTeX2e for authors For more extensive introductory documentation take a look at the links to contributed documentation that have their own page. tex \ chapter {Document Structure} \ section {Reserved Characters} The following symbols characters are reserved by LATEX because they introduce a command and have a special meaning. When I want to insert figures to my documents with Latex(MikTex) all figures put where [!htb] represents the placement options, for example: \caption{XXX}. dvi) can be converted by \$dvipdf hello. cannot find a place to change it to “Serif”. Nov 11, 2009 · It can be frustrating trying to get your figures and tables to appear where you want them in a LaTeX document. ruled - the caption appears above the float, with rules immediately above and below. Change Closed Caption Settings in Settings. See Section2. When you want to include an image or a table that’s wider than the text width, you will notice that even when \centering or the center-environment is used this wide object will not be centered in relation to the surrounding text. t means top: Place it at the top of a page. table(df, caption = "Example Table", captio LaTeX customization¶ The latex target does not benefit from prepared themes. latex: add option to put literal block captions before or after According to literalblockcappos setting in 'sphinxsetup', (t)op or (b)ottom, the caption will be typeset before or after the literal block. I find the default font of the caption is “Sans-serif”, but I . The command is a good one, and many users want to use it. Open an example of different captioning options available in L a T e X in Overleaf. The Options for LaTeX output, and particularly among them the latex_elements variable provides much of the interface for customization. You’ll see it’s suggesting “Figure 1” for the first caption. That does not mean that only these three sizes can be used, it is only the size of the normalsize font. Another option, instead of using a table environment, would be to use the \captionof command provided by the caption package. This package simplifies the way to manipulate the HTML or 'LaTeX' codes generated by 'kable ()' and allows users to construct complex tables and customize styles using a readable syntax. instead of Figure 1: When captions follow the method as described in Captions, the LaTeX export back-end wraps the picture in a floating ‘figure’ environment. You can customize the numbering or lettering style in these cases. Modern installations of LaTeX can use eps files as well, but indirectly. You can also define a global option at the beginning using options(knitr. If you're looking for some captions to read and you don't mind my poor editing skills , this might be the place for you :) View my complete profile Apr 29, 2018 · How to refer to a figure or table from within a LaTeX document. We do not need to include the figure number inside the caption because l a t e x automatically keeps track of the numbering of the figures and itll display it while displaying the caption. Use the placement options: h, t, b and p. Each either loads an additional listings aspect, or changes default properties. The above produces Arabic numerals for the subfigure captions and upper case Roman numerals for the figure caption: If your document has chapters, then the caption labels would be something like 1. If you look at the captions, you can see that the subfigure labels are surrounded by parentheses and a colon separates “Figure 1” from the rest of the caption. If you want to make a float sideways so that the caption is also rotated, you can use Options Default is If you are getting unexpected results, please provide a minimal working example showing any undesired behaviour. g. Jul 13, 2019 · The option escapeinside= {A}{B} will define delimiters for escaping into LaTeX code, i. And floats are meant to move within the document based on float-specifiers submitted by the user. all the code between the string "A" and "B" will be parsed as LaTeX over the current listings style. May 02, 2010 · addcontentsline array article bibliography Bibtex & biblatex book caption chapter citation cite code color definecolor description documentclass draft enumerate equation fancyhdr figure graphicx hyperref includegraphics item itemize label landscape LaTeX letter listoffigures listoftables math minipage reference renewcommand report section LaTeX in Captions You can also use LaTeX in your labels, enclosing the desired LaTeX command in dollar characters (e. minimal Only load a minimal set of code, i. Could you please tell where I can find information on the \caption package for TeX Live 2011/2012 to read about the TeX Live inherent caption package? package manual,2 but analyzes the main options and suggests their use. This is only a suggestion to LaTeX, and it might ignore it if it doesn't think your instruction can be done neatly. This module provides a class to hold, manipulate and employ various options for rendering a graph in LaTeX, in addition to providing the code that actually generates a LaTeX representation of a (combinatorial) graph. Please see package vignette for more information. csv files in LaTeX. Caution: fancyhdr – Extensive control of page headers and footers in LaTeX2ε. options draft, draftcls or draftclsnofoot is given (this option is usually given to the documentclass). You can place it above or below the table. 2 ♦ Chapter 1. The elements within both environments have to be declared beginning with the \item command. The figure or the table and the caption are put into two minipages that are positioned side by side and centered as a whole. The optional arguments [Hhtbp] works like those of gure environment. There must be rubber space between columns that can stretch to fill out the specified width. Below is list of command-line options recognized by the ImageMagick . LaTeX in dvi-mode supports only eps-files. If you really don’t want LaTeX to move your float at all, then use the float package with the command \restylefloat{figure} in the preamble. 6. Here is a collection of tools and ideas that help you get control of those pesky floats. The default settings for subcaptions are: The capt-of package Robin Fairbairns∗ January 22, 2010 1 Why this package? LATEX provides a command (\caption) for adding a caption to a float environment (that is to say, a figure or a table, “out of the box”). Both of these aspects (the label format and the label separator) can be customized by options in the caption package. If these possibilities are sufficient for you, there is usually no Controlling subfigure captions and subfigure placement. Open Settings, and click/tap on the Ease of Access icon. Use the graphicx package with the following command in the preamble: \usepackage{graphicx} Yes, there are others but this is the best and most widely used. The listings package is a source code printer for LATEX. The label format controls how the label shows up: whether it is visible at all, appears plainly or enclosed by parentheses. Nov 11, 2009 · There are other options explained in the placeins documentation. Lingnau and the subfigure package written by S. Male Chastity Captions, Humiliation Captions, Femdom Captions, Tg Captions, Sissy Boy, Sissy Maid, Feminized Husband, Chastity Training, Latex Lady Subscribe to receive captions by email, send your email address to me at brianna9950@gmail. Inserting Images. To read more about how to use options to specify float positions, check out our documentation. Add a Title or Caption Add, edit, or remove a title or caption for a plot. To make a figure in LaTeX is simpler than it looks and just requires a few commands. If you rely on condoms, latex allergies can bring your sex life to a painful halt. The following code examples show Draft mode. prependcaption The prependcaption option triggers a special behaviour of the caption=val option for the todo command, where the given value val is inserted in the inserted todonote. Another useful package is flafter. usetex method (for example, if the appropriate fonts cannot be found. The \caption package allows many other aspects of the options apply to all captions 2 Nov 2011 Within the standard LATEX document classes captions haven't For a later change of options the caption package provides the command. \begin{environment-name} . \documentclass{article} \usepackage{graphicx caption package also cooperates with the float package written by A. e. Marti's tg captions Hello dear reader and welcome to my small sanctuary. In this file you type both the text of your document and the LATEX commands to format it. 15. equations can be entered in the caption field of an input box, say,$\frac{a}{b}=. the caption for table1was speci ed as \caption[An optional table caption (used in the list of tables)]{A long table\label{long}}. Selecting Fonts For LaTeX Captions Figure and Table Captions L aTeX lets you choose from a variety of type styles and sizes for the main text of a document, but selecting a different type style for the captions of figures and tables is somewhat tricky. Latex Masks Options This page presents sample options (type of face, eyes and mouth) of our masks, as well as a variety of combinations of options. In fact \usepackage[hoptionsi]{subcaption} is identical to \usepackage{subcaption} \captionsetup[sub]{hoptionsi} . The Sleep Options Collection. For some details of the LaTeX/PDF builder command line invocation, refer to LaTeXBuilder. You begin figures with \begin{figure}[loc] where loc is a sequence of 0 to 4 letters, each one specifying a location where the figure or table may be placed, as follows: Sep 29, 2017 · Have a Latex Allergy? 4 Safe Condom Types for You. 5 posts • Page 1 of 1 The Subfig Package∗ Steven Douglas Cochran Digital Mapping Laboratory, School of Computer Science Carnegie-Mellon University, 5000 Forbes Avenue The caption package hasn’t found a proper hyperlink anchor for this particular caption, so it decides to ignore the setting hypcap=true (which is set by default). Nov 18, 2011 · In latex, the caption of figure or table is aligned left by default. The capt-of package Robin Fairbairns∗ January 22, 2010 1 Why this package? LATEX provides a command (\caption) for adding a caption to a float environment (that is to say, a figure or a table, “out of the box”). LaTeX floats can also have additional layout ‘:placement’ attributes. Discover the latest submissions to the community and see if you can find the perfect caption to match your own fantasies. jpg when searching for the image file. Sep 24, 2019 · SKYN has a ton of latex-free options too—there are ultra-thin condoms (20 percent thinner than regular condoms), condoms with extra lube, extra-studded condoms, and bigger sizes as well. The following is an example of a caption inside a figure environment. Oct 07, 2017 · Insert an image in LaTeX - Adding a figure or picture Learn how to insert images and caption them. This article describes how to add and change a main title, a subtitle and a caption to a graph generated using the ggplot2 R package. hang, isu Causes the label to be a hanging indentation to the LaTeX writes the captions to this file. latex_options. It will later be hidden from the end user. T e X is a typesetting program designed for high-quality composition of material that contains a lot of mathematical and technical expressions. png, or. Jul 16, 2014 · It would be neat if there were an additional option to place the caption above the table instead of beneath it. 5 REVTEX 4 Command and Options Summary American Physical Society∗ One Research Road, Ridge, NY 11961 (Dated: July 2001) This is the REVTEX 4 Command and Options Sum-mary. Possible options include basic, striped, hold_position, HOLD_position, scale_down & repeat_header. README. 7 Aug 2018 \documentclass{article} \usepackage{subcaption} % Configure main captions \ captionsetup {labelfont={rm,md,bf},textfont={rm,md,sl}} Open an example of different captioning options available in LaTeX in Overleaf. easy. Forgetting to load the float package: The float package provides us with the H option. You can typeset You can typeset stand alone les as well as listings with an environment similar to verbatim This is best done by an experienced LaTeX user. Per default latex use a font size of 10pt (depending of the used documentclass article, report, book und letter) . Images are essential elements in most of the scientific documents. Mylar, plastic, and vinyl options are available — but be sure to search by material rather than searching for “latex-free,” as the search results for “latex-free” includes latex balloons. The space between the minipages is \sidecaptionsep. Often, they end type command of the caption package, the \setcaptionsubtype command sets the sub-type of the box or environment (so \caption will typeset a sub-caption instead of an ordinary one), places a proper hyperlink anchor (non-starred variant only), executes options associated with the sub-type etc. 1. But justification did not change to justified. 5 Apr 1995 way to customize the captions than the above options could do. These are simply possibilities, and LaTeX will The caption package provides many ways to customise the captions in floating environments like figure and table, and Sources, /macros/latex/contrib/caption. Prevent floating of figures or tables. If you want to make a float sideways so that the caption is also rotated, you can use Options Default is Customizing LaTeX Options Overview. T e X. Caption Space \abovecaptionskip=3pt % above caption \belowcaptionskip=3pt % below caption Vertical Space for Flating \textfloatsep=3pt % between top and bottom of float and text \intextsep=3pt % between floats Modify Enumeration: \renewcommand{\labelenumi}{[\Alph{enumi}]} Many document styles recommend to put a caption of the table on top of the table. Jan 23, 2014 · because LaTeX matters question about how to place a sub-caption on top of a sub-figure. \includegraphics[options]{filename} When including EPS or PDF files, use the file name without extension! LATEX will take the EPS, PDFLATEX will take the PDF. So to insert a You can set the caption of an object on tab Basic of the Menu-options. The option obeyFinal does something similar, except that the todonotes package is only disabled if the final option Showing 210 search results for Tag: caption - just some of the 500,000+ absolutely free hentai galleries available. By default, figures are looked for in the current directory (the one in which your. You can align the images in a matrix. To fix this, use the caption package with center as the option. D. Oct 07, 2017 · Draw pictures in LaTeX - With tikz/pgf. Training slides (German) Dec 26, 2016 · Use the “caption” package to customize your tables and figures in LaTeX December 26, 2016 December 23, 2016 John LaTeX , Links , Typesetting chemistry , Design , LaTeX , Typesetting The “caption” package is one of the first packages I found when I began learning LaTeX. Each environment begins and ends in the same manner. Common Causes . Floats are blocks of content that float around the page in the sense that latex chooses where to place them based on certain algorithms. EDU Version 1. dvi The get an pdf file from tex file, run this command \ texi2pdf hello. As usual in LATEX, the package is loaded by \usepackage[hoptionsi]{listings}, where [hoptionsi] is optional and gives a comma separated list of options. Whenever I get that drive to write it's never for erotica anymore. As a starting point, a LaTeX package called columbidaeTitle. The following options are available: active is the most essential option. This text is focused on the preparation of tables and does not address prob-lems that are connected to it as for example how to position floating objects or how to modify the caption [3]. Nov 10, 2011 · Editing caption options in LaTeX using the caption package So I am submitting some of my work to a journal, and the journal has certain stipulations for their format style. tex file is located). Here you will be able to browse, collect, share and even submit your own cuckold caption pictures. On example is the caption labels had to have subfloat lables left justified instead of the default centered and the caption label needs to be FIGURE 1. pos Inside a threeparttable there should be a caption, followed by a tabular environment (tabular, tabular*, tabularx or the like), possibly followed by Some options Function 'kable ()' is a light weight table generator coming from 'knitr'. LaTeX forum ⇒ Graphics, Figures & Tables ⇒ Caption aligned to left Side of Figure Information and discussion about graphics, figures & tables in LaTeX documents. Many examples here involve the now outdated and deprecated \subfig package so it is recommended that you head to Formatting captions and subcaptions in LaTeX to see more up to date examples that use the \subcaption package. LATEX Basics 1. The tabular is the de-facto way of presenting tabular data in LaTeX. 7 Jan 2007 For a later change of options the caption package provides the command haviour, it is adapted from the standard LATEX document classes. svg You can also use LaTeX in your labels, enclosing the desired LaTeX command in Currently this option only affects the Markdown and LaTeX readers. table. A table caption is added through the \caption macro, which automatically numbers the table. This could be changed to 11pt or 12pt as a option of documentclass. Abstract This article documents the LATEX package ‘subfigure’, which provides sup- port for the inclusion of small, ‘sub’, figures and tables. For unordered lists, LaTeX provides the itemize environment and for ordered lists there is the enumerate environment. Oct 07, 2017 · Plots in LaTeX - Visualize data with pgfplots The pgfplots package from tikz/pgf enabled you to plot data directly from . b Bottom - at the bottom of a text page. The latex target does not benefit from prepared themes. Options: PowerPoint -what to do about equations? LATEX pdf -several packages will do this pdfslide or P with pdflatex prosper-most straight-forward; can easily convert existing seminarslides Making Powerpoint-like Presentations with LATEX – p. An expert offers safe alternatives. Setting the draft option will speed up typesetting, because figures are not loaded, just indicated by a frame. 1, etc. plain - the normal style for LaTeX floats, but the caption is always below the content. Documentation for fancybox. Often, they end The caption package provides many ways to customise the captions in floating environments like figure and table, and cooperates with many other packages. In the Captions group you see a button labelled “Insert Caption”. 5 posts • Page 1 of 1 If you are getting unexpected results, please provide a minimal working example showing any undesired behaviour. The pgf/tikz package allows you to draw pictures from within your LaTeX document to keep the style consistent throughout your document. I think supporting short and long versions of captions in pandoc's Markdown is out of scope. The available options are described insection 7. eps extension is appended automatically to the file name. b means bottom: Place it at the bottom of a page. 2. Cochran. ‚e option natbibis used when the corresponding BibTEX style is based on natbib. Introducing the package would go beyond the scope of this article. Shows how to determine both the figure number and the page number a figure is on, using the \ref and \pageref commands. Insert the figure: using the figure environment as follows: Centering wide tables or figures. For these topics, that are in common with all the LaTeX customization¶. Contents[show] Basic Example % Please add the following required packages to your document preamble: % \usepackage{multirow} \begin{table}[] \centering \caption{My caption} \label{my-label Apr 29, 2013 · The tocloft package provides means of controlling the typographic design of table of contents, list of figures and list of tables (copied from its documentation). You may wish the caption on later pages to be di erent to that on the rst page. Delete the draft option or replace it with final in the final document version. 9 Oct 2009 The caption package redefines the LATEX commands \caption, \@caption, (to save TEX memory) and to remove caption options defined with in rmarkdown? How do I add captions for figures and tables? The caption argument is controlled in the chunk option, under the option, fig. plaintop - the normal style for LaTeX floats, but the caption is always above the content. 1 The user interface To use this package just type \usepackage[hoptionsi]{caption} in the preamble of your document, where the following options are supported: normal provides ‘normal’ captions, this is the de-fault The caption package provides many ways to customise the captions in floating environments like figure and table, and cooperates with many other packages. Cuckold Captions are made by combining a cuckold picture or video with text describing the scenario that is taking place. 1 Package options. LaTeX examples: How to reference a figure or table | alvinalexander. 1, 1. sty: Box tips and tricks for LATEX. 1 Basic commands Having read any L A LaTeX font size. There are four places where LaTeX can possibly put a float: h Here - at the position in the text where the table environment appears. \end{environment-name} The following environments are available: array to produce arrays in math environments LATEX will take the EPS file, PDFLATEX will take the PDF file automatically. shadow If the shadow option is given, the inserted todonotes will be displayed with a gray shadow. cap . Table 1: subfigure package options. 2, 2. Facilities include rotating captions, sideways captions, continued captions (for tables or figures that come in several parts). A Sleep Options Memory Foam mattress offers superior pressure relief that can dramatically diminish tossing and turning for a more restful sleep pattern. All these options are presented in specific models of masks from our catalog, and options can be configured by the client in the Mask Designer . All in one place. It details usage for many of the new commands and options that are available in REVTEX 4. ‚e option anonymousis used for anonymous review processes and causes all author information to be obscured. com The table environments by default are not floats in LaTeX. The optional argument to the figure environment tells LaTeX where you'd like it to appear, if possible; the options are h meaning "here", t (at the top of a page), b (at the bottom of a page) and p (on a page without any text). ). It simplifies the positioning, captioning and labeling of such objects within a single figure or tableenvironment. /images/} } tells L a T e X that the images are kept in a folder named images under the directory of the main document. For example. striped will add alternative row colors to the table. Rather than providing ready-made answers, it tries pri-marily to provide some guidance through the existing documentation. That’s the one we want, so go ahead and press it. 6. If you wish to alter this use, \floatname{type}{floatname} Changing float style can be issued with \floatstyle{style} (Works on all subsequent ewfloat commands, therefore, must be inserted before ewfloat to be effective. sty, together with its documentation, gives extensive answers to and solutions for many questions about how to frame or rotate this or that in LATEX. It's part of a default LaTeX installation, so probably you don't need installing something. boxed - a box is drawn that surrounds the float, and the caption is printed below. Tip: By default, a table caption will be center-aligned above a table. If you are using LaTeX to process your document,. Now it's more fantasy based around D&D campaigns. The package is included with the customary \usepackage[options]{preview} You should usually load this package as the last one, since it redefines several things that other packages may also provide. ) To do this, LaTeX options for graphs¶. com! xHamster is the best porn site to get Free Porn pictures! Note: You can specify only one caption per table. The package documentation list the options width and height, as well as others. Sometimes, it's not that beautiful, especially when your article is two column. From the Plot menu, select Title and then Add Title . LaTeX provides several options to handle images and make them look exactly what you need. Place the insertion point where you want the caption to be and head over to the References tab on the ribbon. Please see the REVTEX 4 Author’s Guide for complete informa-tion on how to use This article describes how to add and change a main title, a subtitle and a caption to a graph generated using the ggplot2 R package. LaTeX reacted to this by changing Figure 1--no full stop -- \quad to FIG. t Top - at the top of a text page. The caption package offers customization of captions in floating environments such figure and table and cooperates with many other packages. 'iso' or 'hang' caption; this code was taken from The LATEX Companion[3,. The H argument forces the algorithm to stay in place. The default name that appears at the start of the caption is the type. \caption{Table to test captions and labels} As you may expect this command sets the caption for the table, if you create a list of tables this caption will be used there. In short, the placement options means allowing placement at certain locations: h means here: Place the figure in the text where the figure environment is written, if there is enough room left on the page. Using such an option might look like this: df <- data. Creating Tables with LaTeX Tables are created using the “table” environment given below: \begin{table}[where] table \end{table} In the above syntax, table stands for the contents of the ‘tabular’ environment together with a possible \caption command. Usually, a table caption goes above a table. The package has an option to move the sub-captions on top of the Removing prefix from figure captions in LaTeX. Timothy Van Zandt tvz@Princeton. you can spread out the figures using a number of options. Sometimes, they just seem to float off onto another page of their own accord. Often images are embedded using the figure environment, they can get a caption, a label for reference and they will get numbered and appear in the list of figures. pdf,. The command also accepts other options instead of scale such as rotation, height, width, bounding box, etc. Just drop me a comment below. Captions Lets take the figure we had before and add a caption to it. Whenever we want to use this option, we must include \usepackage{float} in our preamble. 11. LaTeX in Captions You can also use LaTeX in your labels, enclosing the desired LaTeX command in dollar characters (e. State of various checkboxes should now be remembered. LaTeX tables - Tutorial with code examples Learn to create tables in LaTeX including all features such as multi row, multi column, multi page and landscape tables. Resize an image, crop it, change its shades and colors, add captions, and more. However, some editors require the caption to be placed below the table. In this article is explained how to include images in the most common formats, how to shrink, enlarge and rotate them, and how to reference them within your document. This file (. Sep 26, 2015 · Pandoc doesn't natively support lists of figures anyway -- you can only achieve this with a LaTeX command. It has been adopted by many authors and publishers who generate technical books and papers. Usually you don’t have to take care of such options. Add a caption which explains the data shown in the table. Latex can not manage images by itself, so we need to use the graphicx package. Nov 10, 2011 · Editing caption options in LaTeX using the caption sin(x) + cos(x) sin(x) - cos(x) tan(x) sin(x) + cos(x) Bessel function of the second kind, orders 0, 1, 2 Bessel functions of the first kind, orders 0, 1, 2 Bessel function syntax in Maxima; sinh(x) cosh(x) x^2*ln(x) sin^2(x)*cos^2(x) Lybniz - functions sytax When captions follow the method as described in Captions, the LaTeX export back-end wraps the picture in a floating ‘figure’ environment. This is best done by an experienced LaTeX user. LaTeX . in the List of Figures, or set by \ref or \autoref) will link you to the caption of the figure or table, not to the figure or table itself. In some cases it may be useful to typeset the caption aside the figure or the table. The package provides extensive facilities, both for constructing headers and footers, and for controlling their use (for example, at times when L a T e X would automatically change the heading style in use). com LaTeX customization¶. To ensure that your graphics use exactly the same fonts as your document, you can have LaTeX generate and substitute the text for your graph using the psfrag package. You can choose between conforming Memory Foam or natural Latex Foam to create your perfect night's sleep. frame(letters, 1:26) pandoc. A character vector for LaTeX table options. However, the CSS properties text-align and caption-side can be used to align and place the caption. The RStudio Compile PDF command typesets the current TeX or Rnw source file into a PDF. PGF This option will pass the pgf to trimclip and enable the pgfmath option of adjcalc, i. LaTeX will also display hyphenation ( Overfull hbox warning) and justification problems with a small black square. If used, an algorithm is no more a oating object. Option Description normal Provides ‘normal’ subcaptions, this is the default. \end{tabular*} These environments produce a box consisting of a sequence of rows of items, aligned vertically in columns. We do not need to include the figure number inside the caption, because L a T e X automatically keeps track of the numbering of the figures, and it'll display it while displaying the caption. format = "latex") so you don’t repeat the step every time. However, I am happy to help should you have any specific question. In this case put the \caption command in the rst heading, and put a subsidiary caption in a \caption[] command in the main heading. longtable The longtable package de nes a new environment, longtable, which has most of the features of the tabular environment, but produces tables which may be broken by TEX’s standard page-breaking algorithm. caption latex options | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9461789727210999, "perplexity": 2827.629663619565}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875144167.31/warc/CC-MAIN-20200219184416-20200219214416-00512.warc.gz"} |
https://indico.cern.ch/event/129980/contributions/1351157/ | # DPF 2011
8-13 August 2011
Rhode Island Convention Center
US/Eastern timezone
## Measurement of three-jet differential cross sections $\boldsymbol{d\sigma_{\text{3jet}} / dM_{\text{3jet}}}$ in $\boldsymbol{p\bar{p}}$ collisions at $\boldsymbol{\sqrt{s}=1.96}$ TeV
10 Aug 2011, 14:00
20m
551 A (Rhode Island Convention Center)
### 551 A
#### Rhode Island Convention Center
Parallel contribution Perturbative and non-Perturbative QCD
### Speaker
Lee Sawyer (College of Engineering and Science-Louisiana Technical Universi)
### Description
We present the first measurement of the inclusive three-jet differential cross section as a function of the invariant mass of the three jets with the largest transverse momenta in an event in $p\bar{p}$ collisions at $\sqrt{s}=1.96\, \mathrm{TeV}$. The measurement is made in different rapidity regions and for different jet transverse momentum requirements and is based on a data set corresponding to an integrated luminosity of $0.7\, \mathrm{fb}^{-1}$ collected with the D0 detector at the Fermilab Tevatron Collider. The results are used to test the three-jet matrix elements in perturbative QCD calculations at next-to-leading order in the strong coupling constant. The data allow discrimination between parametrizations of the parton distribution functions of the proton.
### Primary author
Lee Sawyer (College of Engineering and Science-Louisiana Technical Universi)
### Presentation Materials
SawyerDPF2011MultijetXsecs.pdf SawyerDPF2011MultijetXsecs.pptx | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8861343860626221, "perplexity": 3460.591929525571}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243991650.73/warc/CC-MAIN-20210518002309-20210518032309-00165.warc.gz"} |
http://mathhelpforum.com/algebra/74790-level-maths-questions-inequalities-simultaneous-equations.html | # Thread: A level maths questions on inequalities and simultaneous equations
1. ## A level maths questions on inequalities and simultaneous equations
I have mock exams next week and have been trying to revise inequalities and sim eqs but I am finding any questions using a constant, k and the discriminant very difficult. If I post some of said questions I would appreciate some help
Inequalities:
'By considering the discriminant, or otherwise, find the range of values of k that give each of these equations two distinct real roots.' [I got as far as thinking that the discriminant must be greater than 0?]
a) x²+3x+k=0
b) 3x²+kx+2
c) k(x²+1)=x-k
'Find the range of values for k that give these equations no real roots'
a) x²+6x+k=0
b) 2x²+kx+1=0
c) (k+1)x²+4kx+9=0
'Show that x²+2kx+9 is greater than or equal to 0 for all real values of x, if k² is less than or equal to 9.
Simultaneous equations:
'Find the possible values of k if y=2x+k meets y=x²-2x-7'
a) in two distinct real points b) in just one point
'Find the range of values of k for which kx+y=3 meets x²+y²=5 in two distinct points'
'Find the range of values for qhich y=kx-2 is tangent to the curve y=x²-8x+7'
Thanks for reading through this, sorry it is so long!
2. Originally Posted by Turple
Inequalities:
'By considering the discriminant, or otherwise, find the range of values of k that give each of these equations two distinct real roots.' [I got as far as thinking that the discriminant must be greater than 0?]
a) x²+3x+k=0
b) 3x²+kx+2
c) k(x²+1)=x-k
Your thinking is correct. So in the first case the condition is:
$3^2-4k>0$
expand and rearrange:
$-4k>-9$
multiply through by -1 (which changes the direction of the inequality):
$4k<9$
or:
$k<9/4$
Now the others are similar, rearrange them into standard quadratics, then write out the condition on the discriminant, and simplify.
CB
3. Originally Posted by Turple
'Find the range of values for k that give these equations no real roots'
a) x²+6x+k=0
b) 2x²+kx+1=0
c) (k+1)x²+4kx+9=0
'Show that x²+2kx+9 is greater than or equal to 0 for all real values of x, if k² is less than or equal to 9.
No real roots requires that the discriminant be less than 0, otherwise as before.
The discriminant of: $x²+2kx+9$ is:
$4k^2-4\times9.$
That $x²+2kx+9$ is greater than or equal to $0$ implies that it has no real roots (as it must be positive for large absolute values of $x$), so this is true when:
$4k^2-36<0$
or:
$4k^2<36$
which is:
$k^2<9$
as required
CB
4. Originally Posted by Turple
Simultaneous equations:
'Find the possible values of k if y=2x+k meets y=x²-2x-7'
a) in two distinct real points b) in just one point
'Find the range of values of k for which kx+y=3 meets x²+y²=5 in two distinct points'
'Find the range of values for qhich y=kx-2 is tangent to the curve y=x²-8x+7'
Thanks for reading through this, sorry it is so long!
These all follow the same sort of pattern, you substitute y from the linear equation for the y in the other. Then simplify down to a quadratic in x.
Then the questions all reduce to questions about the number of real roots of quadratics (tangency is equivalent to one real root).
CB | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 12, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8277860879898071, "perplexity": 753.0825098081677}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-34/segments/1502886123312.44/warc/CC-MAIN-20170823171414-20170823191414-00615.warc.gz"} |
http://seekingalpha.com/article/170066-were-out-of-recession-but-a-long-way-from-recovery | We're Out of Recession, But a Long Way from Recovery
by: Dr. Bill Conerly
The numbers for the third quarter look nice, or what passes for nice these days. GDP rose smartly, pretty much confirming the general view that the recession is over (more on that below).
The details surprised me a bit, even though the total growth was in the ballpark of my forecast (4.2 percent, compared to 3.5 percent growth actual). Consumer spending was stronger than I had expected, even with Cash for Clunkers. That may not be sustained. However, inventories contracted much more than I had expected. We are definitely going to get an inventory turnaround soon, and that will add quite a bit of strength to the economy.
I'll update my forecast and share it with you.
Now about the end of the recession. We economists define the recession as the period when the economy is going downhill. That period is over. However, we have not recovered all the ground that we lost. Think of it this way: we fell down a 10-foot hole, we hit bottom and took one step upward. We are out of recession, but we're still nine feet down a ten-foot hole. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8051421642303467, "perplexity": 1913.6901415524587}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560279169.4/warc/CC-MAIN-20170116095119-00177-ip-10-171-10-70.ec2.internal.warc.gz"} |
http://math.stackexchange.com/questions/246215/how-to-prove-a-symmetric-matrix-is-positive-semidefinite | # how to prove a symmetric matrix is positive semidefinite?
I have a symmetric matrix where the diagonals are all positive. I need to prove the matrix is positive semidefinite. The matrix is made up of a bunch of constants and I tried getting the eigenvalues using Maple and it was a mess. I also tried doing something I found online How to check if a symmetric $4\times4$ matrix is positive semi-definite?. I tried doing Robert Israel's answer and it ended up being a mess. Is there an easier way to prove positive semidefinite?
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How large is your matrix? Perhaps you can post it here. I would venture to guess that you may be able to apply the Gershgorin Circle Theorem. This is noted in Calle's answer in the question you linked to. – EuYu Nov 28 '12 at 4:21
Symmetric matrices with positive diagonals aren't always positive. (E.g., $\begin{bmatrix}1&2\\2&1\end{bmatrix}$.) What is your matrix? – Jonas Meyer Nov 28 '12 at 4:21
If your matrix is not too large, see this : math.stackexchange.com/questions/40849/… – Bhargav Nov 28 '12 at 4:22
@b555: That is the question user972276 links to above. – Jonas Meyer Nov 28 '12 at 4:23
oops my bad, sry .. had read the q i linked just a few days abck and couldnt read this q fully >.< – Bhargav Nov 28 '12 at 4:26 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8122625350952148, "perplexity": 359.4238516259654}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-35/segments/1440645258858.62/warc/CC-MAIN-20150827031418-00042-ip-10-171-96-226.ec2.internal.warc.gz"} |
https://www.ias.ac.in/listing/bibliography/jcsc/LOVE_KARAN_RANA | • LOVE KARAN RANA
Articles written in Journal of Chemical Sciences
• Triethylammonium salt of dimethyl diphenyldithiophosphates: Single crystal X-ray and DFT analysis
The present work demonstrates the single crystal X-ray and DFT analysis of $[{(2,4-CH_{3})_{2}C_{6}H_{3}O}_{2}$PS_{2}HNEt_{3}]$(1) and$ [{(3,4-CH_{3})_{2}C_{6}H_{3}O}_{2}PS_{2}HNEt_{3}]$(2) along with computational analysis of$ [{(3,5-CH_{3})_{2}C_{6}H_{3}O}_{2} $PS_{2}HNEt_{3}]$ (3) by using density functional theory (DFT) in its hybrid form B3LYP method. Compounds1 and 2 crystallize in the orthorhombic space group Pbca and triclinic space groupP1,respectively andtheir X-ray analysis reveals that phosphorus atom is coordinated to the two S and two O atoms to form tetrahedralgeometry. The structure is stabilized by cation–anion N–H.... S hydrogen bonded interactions. The structuralparameters, vibrational bands and energy gaps of frontier orbitals (HOMO–LUMO) have been calculated.The calculated geometric and spectral results matched the experimental data with good agreement. Theoreticallycalculated frontier molecular orbitals (HOMO–LUMO) and their energies suggest that charge transferoccurs within the compounds.
• # Journal of Chemical Sciences
Current Issue
Volume 131 | Issue 9
September 2019
• # Editorial Note on Continuous Article Publication
Posted on July 25, 2019 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4737536907196045, "perplexity": 12349.228211416425}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986672431.45/warc/CC-MAIN-20191016235542-20191017023042-00057.warc.gz"} |
https://www.coursehero.com/file/11192057/hwsolution9-pdf/ | hwsolution9_pdf - lin(gdl353 Homework 9 shubeita(58390 This...
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lin (gdl353) – Homework 9 – shubeita – (58390) 1 This print-out should have 16 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001(part1of2)10.0points Given a current segment which flows along the edges of a cube as shown in the figure. The conventional Cartesian notation of ˆ ı (a unit vector along the positive x axis), ˆ (a unit vector along the positive y axis), and ˆ k (a unit vector along the positive z axis), is used. The cube has sides of length a . The current flows along the path A→C→D→E→G . There is a uniform magnetic field vector B = B ˆ ı . x y z B B B A C D E G a a Find the direction hatwide F vector F bardbl vector F bardbl of the resul- tant magnetic force on the current segment ACDEG . 1. hatwide F = 1 2 parenleftBig ˆ ˆ k parenrightBig 2. Undetermined, since the magnitude of the force is zero. 3. hatwide F = ˆ 4. hatwide F = ˆ k 5. hatwide F = ˆ correct 6. hatwide F = ˆ ı 7. hatwide F = ˆ k 8. hatwide F = 1 2 parenleftBig ˆ + ˆ k parenrightBig 9. hatwide F = 1 2 parenleftBig ˆ k ˆ parenrightBig 10. hatwide F = ˆ ı Explanation: Note: The force on wire segment AC is canceled by the force on wire segment EG . The current in wire segment CD flows in the ˆ ı direction and the current in wire segment DE flows in the ˆ k direction. x z A G a a TopView B B B ˆ ı ˆ k ˆ ı ˆ k B B B The magnetic force on a wire is given by vector F mag = I vector × vector B . The vector vector is given by the sum of the current segments vector = −→ AC + −→ CD + −→ DE + −→ EG , and this is the vector −→ AG , (see figure above). The magnitude is given by vector F vector × vector B ı ˆ k ) × ı ) = (ˆ ı × ˆ ı ) ( ˆ k × ˆ ı ) = 0 ˆ hatwide F = ˆ . 002(part2of2)10.0points Find the magnitude bardbl vector F magnetic bardbl the magnetic
lin (gdl353) – Homework 9 – shubeita – (58390) 2 field exerts on the current segment ACDEG if the. Magnetic field is 1 . 78 T, a is 3 . 81 m, and the current is 5 . 14 A. with the vertical when in equilibrium ( v = 0 m / s), determine the strength of the magnetic field. 003 10.0points If the wires make an angle of 22 with the vertical when in equilibrium ( v = 0 m / s), determine the strength of the magnetic field.
A metal rod having a mass per unit length of 0 . 0424 kg / m carries a current of 4 . 9 A . The rod hangs from two wires (in the same plane as the rod) in a uniform vertical magnetic field as in the figure. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9069928526878357, "perplexity": 2549.6830852670273}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320304947.93/warc/CC-MAIN-20220126101419-20220126131419-00397.warc.gz"} |
https://stats.stackexchange.com/questions/83577/gee-choosing-proper-working-correlation-structure | # GEE: choosing proper working correlation structure
I am an epidemiologist trying to understand GEEs in order to properly analyze a cohort study (using Poisson regression with a log link, to estimate Relative Risk). I have a few questions about the "working correlation" that I would like someone more knowledgable to clarify:
(1) If I have repeated measurements in the same individual, is it usually most reasonable to assume an exchangeable structure? (Or an autoregressive if measurements show a trend)? What about independence - are there any cases where one could assume independence for measurements in the same individual?
(2) Is there any (reasonably simple) way to assess the proper structure by examining the data?
(3) I noticed that, when choosing an independence structure, I get the same point estimates (but lower standard errors) as when running a simple Poisson regression (using R, function glm() and geeglm() from package geepack). Why is this happening? I understand that with GEEs you estimate a population-averaged model (in contrast to subject-specific) so you should get the same point estimates only in the linear regression case.
(4) If my cohort is at multiple location sites (but one measurement per individual), should I choose an independence or an exchangeable working correlation, and why? I mean, individuals in each site are still independent from each other, right?? Thus for a subject-specific model, for example, I would specify the site as a random effect. With GEE however, independence and exchangeable give different estimates and I am not sure which one is better in terms of underlying assumptions.
(5) Can GEE handle a 2-level hierarchical clustering, i.e. a multi-site cohort with repeated measures per individual? If yes, what should I specify as a clustering variable in geeglm() and what should be the working correlation if one assumes for example "independence" for the first level (site) and "exchangeable" or "autoregressive" for the second level (individual)?
I understand these are quite a few questions, and some of them may be fairly basic, but still very difficult for me (and maybe other novices?) to grasp. So, any help is greatly and sincerely appreciated, and to show this I have started a bounty.
1. Not necessarily. With small clusters, imbalanced design, and incomplete within-cluster confounder adjustment, exchangeable correlation may be more inefficient and biased relative than independence GEE. Those assumptions can be rather strong, too. However, when those assumptions are met, you get more efficient inference with the exchangeable. I have never found an instance when AR-1 correlation structures make sense, since it's uncommon to have measurements that are balanced in time (I work with human subjects data).
2. Well, exploring correlation is good and should be done in data analysis. However, it really shouldn't guide decision making. You can use variograms and lorellograms to visualize correlation in longitudinal and panel studies. Intracluster correlation is a good measurement of the extent of correlation within clusters.
3. Correlation structure in GEE, unlike mixed models, does not affect the marginal parameter estimates (which you are estimating with GEE). It does affect the standard error estimates though. This is independent of any link function. The link function in the GEE is for the marginal model.
4. Sites can be sources of unmeasured variation, such as teeth within a mouth, or students within a school district. There is the potential for cluster level confounders in these data, such as genetic propensity to tooth decay or community education funding, so for that reason, you will get better standard error estimates by using an exchangeable correlation structure.
5. Calculation of marginal effects in a GEE is complicated when they're not nested but it can be done. Nesting is easy, and you do just as you've said.
• (Regarding #5) So in the case of nested clustering one just selects the top level cluster variable and that's it? – Theodore Lytras Jan 30 '14 at 21:35
• No, you can create a hierarchical two level exchangeable correlation structure and consistently estimate the two separate correlation parameters for correlation using a 3 step EM algorithm. That way you would know kids within communities are correlated, but not as correlated as kids within a household. – AdamO Jan 30 '14 at 21:58
• Sorry, I do not understand this. Could you point me to some code, preferably in R or Stata? I guess that should help. – Theodore Lytras Jan 30 '14 at 23:04
• @TheodoreLytras sorry, I was mistaken. Your previous assertion is correct. From the very paper I linked, " In addition, if multiple clusters are perfectly nested, GEE clustering on the top level cluster accounts for the multilevel correlation structure through the sandwich variance estimator". – AdamO Jan 30 '14 at 23:22
• Maybe you mean something else, but when you state "Correlation structure in GEE, unlike mixed models, does not affect the marginal parameter estimates", I think this is not true. At least, if you mean that the coefficients are unchanged by choosing a different working correlation matrix, this is not what happens: the correlation matrix works through in the weighting matrix and affects the covariance matrix as well as the coefficients. – Nick Jun 14 '17 at 18:52
(1) You will likely need some kind of autoregressive structure, simply because we expect measurements taken further apart to be less correlated than those taken closer together. Exchangeable would assume they are all equally correlated. But as with everything else, it depends.
(2) I think this kind of decision comes down to thinking about how the data were generated, rather than seeing how they look.
(4) it depends. For example, kids nested in schools should not, in most cases, be treated as independent. Due to social patterning, etc, if I know something about a kid in a given school, then I probably know at least a little bit about other kids in the schools. I once used GEE to look at relationships between different social and economic indicators and obesity prevalence in a birth cohort where participants were nested in neighborhoods. I used an exchangeable structure. You can find the paper here and check some of the references, including 2 from epi journals.
(5) Apparently so (e.g. see this example), but I can't help with the R specfics of doing this.
• This is helpful indeed, but it makes me wonder why would anyone then use an independence structure, because clustering per se implies a degree of similarity between observations. However, I am under the impression that in the case of schools the similarity is in relation to other schools, and within each school pupils would be independent. So I'm still not very clear on that. – Theodore Lytras Jan 28 '14 at 11:38
• Yes, if you restricted your sample and subseqeuent modelling to a single school, no worries. In this case it would be more justifiable to assume the errors are iid. But once you start combining kids from different schools into the same sample/model, that assumption becomes tennuous, unless you account for school in the model, i.e. so that the errors conditional on school are assumed iid. – D L Dahly Jan 30 '14 at 13:18
• It's also worth noting that people might be more helpful to you if you could provide some details regarding sample size, the number and timing of repeat measures, the number of clusters, etc. – D L Dahly Jan 30 '14 at 13:32
• @DLDahly your point in (1) is not something I often find in biostatistical panel analyses. One of the assumptions behind AR-N correlation structures is that, given enough time between them, two measurements on the same individual will be as uncorrelated as two measurements between different individuals. However, the underlying major between-cluster confounders are often not time varying covariates (such as genetic markers), and assuming otherwise is very difficult (if not impossible) to assess. A lorrelogram is a very good place to start, though. – AdamO Jan 31 '14 at 18:58
(0) General comments: most of the models I see on crossvalidated are far too complicated. Simplify if at all possible. It is often worth modeling with GEE and mixed model to compare results.
(1) Yes. Choose exchangeable. My unambiguous answer is based on the most widely touted benefit of GEE: resilience of estimates to assumptions made.
If you look at studies in your field you should see that exch is the default option. It doesn't mean it is the best, but should be the first to consider. Advising exch will be the best advise without having detailed knowledge of your data.
(2) Yes, there are data driven approaches such as "QIC". This is a Stata example, but widely accepted as a reasonable option, though very rarely used in practice: http://www.stata-journal.com/sjpdf.html?articlenum=st0126)
(3) Point estimates are never the exact same (unless you are using indep correlation structure), but are usually fairly close. You can find many articles comparing simple/gee/mixed effects model estimates to get a feel for this (https://recherche.univ-lyon2.fr/greps/IMG/pdf/JEBS.pdf) Most textbooks also have a table or two for this. For an independent correlation structure you are essentially running the poisson model with robust SEs. So the estimates will be the exact same. The SE are usually larger. But sometimes robust SE are smaller (that is life: google with provide pain free explanation if interested)
(4) See (1) and (2) above.
(5) No. Or better stated, you can do anything if you put enough effort into it but it is very rarely worth the effort.
You're using the wrong approach with a gee to do what you are doing because you don't know the structure and your results will be likely confounded. Refer to Jamie Robinson this. You need to use long. TMLE (mark van der laan) or perhaps a gee with iptw weights. Not accounting for correlation does underestimate variance. Just think if all repeated measures were 100% correlated, then you would effectively have way fewer observations (essentially only n for your n subjects) and smaller n means higher variance.
• If you have a non survival type of outcome you can use the gee approach with independent corr structure and iptw weights as suggested for unbiased estimates, assuming you get the propensity score right. TMLE is best pretty much in all cases, survival or not because you can use ensemble learning to predict propensity scores and sequential regressions and still obtain efficient inference. Your approach will surely be biased and give incorrect inference and the larger your sample size, if there is no effect, you will likely pinpoint a wrong significant effect!! – Jonathan Levy Oct 16 '16 at 6:50
• This could use more detail. What is Janie Robinson? Which paper by van der Laan? – mdewey Oct 16 '16 at 8:25
• @mdewey sorry, typo, meant Jamie Robins. Try Robins, hernan, Babette 2000 marginal structural models and causal inference--great method in there for non-survival outcome including way to do msm with effect modifiers. For laan, reference the book, targeted learning. Like I said, laan is probably best but takes more to understand. The R package Ltmle does this methodology but takes some time to learn. – Jonathan Levy Oct 16 '16 at 12:10 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6548532843589783, "perplexity": 1107.549513199333}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195530250.98/warc/CC-MAIN-20190724020454-20190724042454-00219.warc.gz"} |
https://www.nature.com/articles/s41467-017-01353-2?error=cookies_not_supported&code=e01a4600-e4ec-4ee8-a66e-425feb2821ff | ## Introduction
An ordered solid exhibits elastic (reversible) or plastic (irreversible) deformations, depending on the strength of the force applied. Conceptually similar phenomena have also been observed in electronic systems, such as ferroelectric/ferromagnetic domain walls1, 2, flux-line lattices in type-II superconductors3, and charge/spin density waves4, 5. Domain walls, for example, are more or less meandering by nature in real materials because of random pinning-potential, and they further deform under an effective force, such as a magnetic/electric field or electric current. When the effective force is relatively weak, the induced deformations are small and return to their original positions if the force is removed; that is, domain walls remain trapped in a potential valley (a reversible/pinning regime). In contrast, as the effective force increases, this reversible/pinning regime eventually collapses, and some domain-wall segments begin to exhibit creep, a thermally assisted sluggish motion overcoming potential barriers. Relatively large deformations are thus induced and are no longer reversible (an irreversible/creep regime). This universal behavior is analogous to that in elastic and plastic regimes in ordered solids; therefore, the electronic media described are sometimes viewed as elastic objects.
Magnetic skyrmions6,7,8,9,10,11,12, spin-swirling topological objects of 10–100 nm in diameter, constitute a new member of elastic objects in electronic systems. Whereas the skyrmion is a pancake-like entity in an ultrathin film, it forms a cylindrical structure in a bulk sample13 (Fig. 1a), similarly to a flux-line in superconductors. In particular, in bulk chiral magnets, such as MnSi and (Fe1–xCox)Si, magnetic skyrmion strings are observed as a thermodynamically stable skyrmion-string-lattice (SkS-L) phase8, 9 in which skyrmion strings pointing along an external magnetic field are arranged in the form of a close-packed triangular lattice. Notably, it has been found for MnSi that the thermodynamically stable SkS-L begins to move at extremely low electric current density14, 15, on the order of 106 A m–2, which is 5–6 orders of magnitude smaller than the value required for current-induced ferromagnetic domain-wall motion16, 17. Magnetic skyrmions are therefore attracting considerable research attention as a potential candidate for next-generation information carriers18,19,20.
In current-drive racetrack-type applications21 based on isolated skyrmions22, 23, one must manipulate a metastable isolated skyrmion because thermodynamically stable skyrmions have a propensity to condense and entirely fill a sample/device10, 24; thus, the behavior of metastable isolated pancake-like skyrmions under current is of practical interest. In this context, ferromagnetic ultrathin-film stacks, such as polycrystalline Pt/Co/Ta and single-crystalline Pt/CoFeB/MgO, have recently been investigated23, and it has been observed that, whereas almost all skyrmions move uniformly in the single-crystalline Pt/CoFeB/MgO, pinned and moving skyrmions coexist in polycrystalline Pt/Co/Ta. Notably, in the latter case, a moving skyrmion sometimes collides with a pinned one and irreversibly merges into one pinned skyrmion23. These observations suggest that under the influence of random pinning potential, current-induced skyrmion dynamics may be more complex than the uniform flow of a fixed number of skyrmions, particularly near the critical current density at which skyrmions begin to move.
The situation may be even more complex in metastable skyrmion strings in a bulk sample. Notably, the diameter of a skyrmion is 10–100 nm, whereas the skyrmion-string length is on the order of the sample thickness (typically, 10–1000 μm). Ordinary bulk crystals at finite temperatures contain a finite density of defects, such as vacancies, as the most thermodynamically stable state, and a defect-free crystal has a higher free energy25. Analogously, such a long skyrmion string is unlikely to be intact at finite temperatures but should contain finite topological defects, that is, pairs of the emergent magnetic monopole and antimonopole26,27,28, as schematically shown in Fig. 1a, b. Although the stability and/or dynamics of the emergent magnetic (anti)monopoles are likely directly linked with the controllability of the metastable skyrmion strings, the details remain unclear because of the lack of experiments targeting metastable skyrmion strings in a bulk sample.
In this article, we describe the behavior of the metastable SkS-L in MnSi under pulsed electric current by means of the Hall resistivity, ρ yx, which is a sensitive probe for condensed topological skyrmions29, 30, particularly in MnSi31,32,33,34. We first write a metastable SkS-L in a limited area of the bar-shaped sample by using a local thermal quenching technique34,35,36 while keeping the other area in the conical state, which is the thermodynamically most stable at the magnetic field investigated; next, ρ yx is measured at two distant positions before and after in-plane current pulse applications to determine how the pulse affects the written metastable SkS-L. We find that, whereas the written metastable SkS-L is maintained (the reversible/pinning regime) at low current densities (1–2 × 106 A m–2), it undergoes irreversible topological unwinding at higher current densities (>3 × 106 A m–2) rather than being transported along the current direction. Moreover, the critical current density above which the topological unwinding appears is larger for a shorter pulse width, reminiscent of viscoelastic characteristics accompanying a pinning-creep transition in domain-wall motion. The smallness of the involved current density and the numerical simulation results suggest that the topological unwinding is initiated by the current-induced depinning of originally segmented skyrmion strings.
## Results
### Sample configuration
We targeted the archetypal skyrmion-hosting material MnSi and planned to write a metastable SkS-L domain in the matrix of a thermodynamically stable conical order to detect the translation of the SkS-L, if it occurred, by probing the Hall voltage at a distant position. In planning how to prepare the metastable SkS-L in the area of interest, we noted that the SkS-L can be created as a metastable state by employing rapid cooling (>100 K s−1) by way of the thermo-equilibrium SkS-L phase (see Fig. 2a, b)34, 37. If such thermal quenching is locally implemented, then the metastable SkS-L domain is also expected to be written locally.
Figure 2c, d displays the sample configuration devised for this purpose. In addition to the standard six contacts c1–c6, two large electrodes e1 and e2 are attached on the sample surface. The contact resistance of e1 and e2 is relatively high, ≈10–15 Ω (for comparison, it is less than 0.1 Ω for the current electrodes c1 and c2), to facilitate local Joule heating; the heating is followed by rapid cooling after the pulse cessation. When a single electric pulse of an appropriate magnitude and width is applied to the e1–c2 pair (or the e2–c2 pair), for example, at 15 K and 0.249 T, the SkS-L-to-conical transition line is quickly crossed during such rapid cooling (Fig. 2a), thus leading to the writing of a metastable SkS-L domain around the electrode e1 (or e2) only. For convenience, we label the area around the electrode e1 and e2 as areas 1 and 2, respectively, and refer to the electric-heating pulse as a writing pulse.
### Local writing of the metastable SkS-L
The conjectured operation was substantiated by simultaneously probing the Hall voltages near the electrodes e1 and e2. To this end, we measured ρ yxH profiles at the c3–c4 and c5–c6 pairs at 15 K; these are shown in Fig. 2e, f, respectively. When no writing pulse was applied (the black curves), the c3–c4 and c5–c6 pairs exhibited nearly the same profiles, thus reflecting the homogeneous conical order as the initial state. In contrast, after a single writing pulse of 110 mA and 15 ms was applied to the electrode e1 at 0.249 T (for the details of the pulse-magnitude dependence, see Supplementary Fig. 1), an enhanced ρ yx was observed for the c3–c4 pair (Fig. 2e), whereas such an enhancement was not discerned for the c5–c6 pair (Fig. 2f); furthermore, when the magnetic field was subsequently increased (the red curves) or decreased (the green curves) from 0.249 T, ρ yx at the c3–c4 pair remained enhanced and then decreased to the values corresponding to the case in which no writing pulse was applied. This additional Hall signal, Δρ yx (|Δρ yx|≈24–25 nΩ cm), known as the topological Hall effect29, 30, is a hallmark of condensed topological skyrmions31,32,33,34, thus demonstrating successful writing of the metastable SkS-L domain in the area 1. We also confirmed that when the writing pulse was applied to the electrode e2, an enhanced Δρ yx of a similar magnitude appeared for the c5–c6 pair, whereas |Δρ yx| ≤ 2 nΩ cm for the c3–c4 pair (see Supplementary Fig. 2).
### Current application to the metastable SkS-L
Having established a method to create metastable SkS-L in an area-selective manner, we were able to address the type of dynamics that emerges from the metastable SkS-L under current applications. After writing a metastable SkS-L in the area 1, we applied positive in-plane current pulses (that is, current flowing from c1 to c2) of various magnitudes with a fixed pulse width, 25 ms, and then measured ρ yx at the c3–c4 and c5–c6 pairs simultaneously to observe the effects of the pulse application.
Figure 3a, b displays the topological Hall signal, Δρ yx, at the c3–c4 and c5–c6 pairs vs. in-plane pulse numbers applied, respectively, for several current magnitudes at 15 K. Here, three aspects can be highlighted. First, at the lowest current density, +1.0 × 106 A m–2, the topological Hall signal at the c3–c4 pair remains constant even after 3000 pulses are applied (Fig. 3a). This finding suggests that the weak current application introduces no appreciable changes to the written metastable SkS-L; that is, at this current density, the metastable SkS-L remains in the reversible/pinning regime. Nevertheless, this regime clearly collapses at higher current densities, and the topological Hall signal (equivalently, the density of skyrmion strings) at the c3–c4 pair decreases by the repetitive pulse applications. Second, in this irreversible regime, the decrease in the topological Hall signal occurs primarily at the early stage of the repetitive pulse applications; the decrease then becomes more moderate as the pulse number increased (Fig. 3a). Third, no appreciable signal is transferred to the Hall signal at the c5–c6 pair (Fig. 3b), even after Δρ yx at the c3–c4 pair largely disappears. The second and third aspects are not compatible with the simplest scenario that the metastable SkS-L domain may move as a whole along the current direction. In such a case, the Δρ yx signal at the c3–c4 pair would remain constant as long as the current-induced shift of the metastable SkS-L were small, and the signal would eventually be transferred to the Hall signal at the c5–c6 pair; these are not the case in the experiments. We also performed the experiments with negative in-plane current pulses (current flowing from c2 to c1), but essentially the same results were obtained (Supplementary Fig. 3).
To gain more insight into the decrease in the topological Hall signal, we performed similar experiments but with the alternating application of positive and negative in-plane pulses. In this pulse sequence, the sum of the total effective force applied (including its sign) is zero by definition; thus, the net shift of the metastable SkS-L is not expected, even if each current pulse were to be accompanied by its finite shift. For comparison, the results are plotted in Fig. 3a, labeled with the current magnitude, +/–8.2 and +/–3.4 (×106 A m–2). Remarkably, these pulse sequences exhibited a similar (or even larger) decrease in the topological Hall signal. Therefore, the observed Δρ yx profiles at the c3–c4 pair cannot be a consequence of the translation of the metastable SkS-L. Alternatively, its destruction can account for this observation: the metastable SkS-L undergoes current-induced topological unwinding into a non-topological spin texture, which is probably the thermodynamically most stable conical state.
Regarding the origin of the topological unwinding, we can rule out a Joule-heating-assisted mechanism. We estimated the increase of the local temperature in the area 1 by measuring the voltage at the c3–c4 pair during the pulse application and found a temperature increase of only 0.2 K (specifically, 15.0 → 15.2 K) under 8.2 × 106 A m–2 and 125 ms (the maximum and longest current density applied in this study: for details, see Supplementary Fig. 4). Moreover, the estimated lifetime of the metastable SkS-L is beyond 1015 years at 15 K34; thus, the slight temperature increase is expected to play a negligible role in the observed topological unwinding. The appreciable difference of the data between +/–8.2 and +8.2 × 106 A m–2 (Fig. 3a) also cannot be ascribed to Joule heating, which should be symmetric with respect to the current polarity, at least, for Ohmic contacts (this is the case in the experiments; see Supplementary Fig. 4).
When considering the destruction of skyrmion strings from the perspective of topology, pair creation of the emergent magnetic monopole-antimonopole (Fig. 1a, b) and their subsequent unbinding motion are expected to be involved26,27,28, analogous to the nucleation and subsequent growth in ordinary first-order phase transitions. To gain insight into which process is more relevant to the current-induced topological unwinding, it is helpful to consider the magnitude of the involved current density. Both a theoretical paper28 and our order-of-magnitude estimates (Supplementary Note 1) predict that the monopole-antimonopole pair creation requires a current density of ~1012 A m–2, orders of magnitude larger than the value used in the present experiments, that is, 106–107 A m–2. Therefore, we conclude that the monopole-antimonopole pairs preexist in the quenched SkS-L and hence that their current-induced unbinding motion plays a key role in the topological unwinding. Meanwhile, 106 A m–2 is the order on which the skyrmion strings start to move15, thus suggesting that the topological unwinding is also related with the creep of the skyrmion strings. In fact, the current-induced topological unwinding at 10 K was found to be less pronounced than that observed at 15 K (Supplementary Fig. 5), in agreement with the notion of creep, which is innately thermally assisted38,39,40,41,42,43,44.
### Numerical simulations
To determine how the creep of the skyrmion string and the unbinding motion of the preexisting monopole-antimonopole pairs are correlated with each other in the context of the current-induced topological unwinding, we performed micromagnetic simulations of the chiral magnetic system including randomly distributed pinning sites (for details, see the Methods section). We found that under certain numerical conditions, a segmented skyrmion string in a ferromagnetic background can be metastable at zero or weak currents (Fig. 4a). Nevertheless, when the applied current exceeds a specific threshold value, the segmented skyrmion string starts to move; remarkably, this process is also accompanied by the motion of (anti)monopole such that the skyrmion string shortens, as shown in Fig. 4b–d (see also Supplementary Movie 1). As a result, the metastable segmented skyrmion string quickly disappears without a long-distance creep (Fig. 4d). This numerical result establishes a clear example of topological unwinding being initiated by the onset of the creep motion of metastable segmented skyrmion string, corroborating the experimental observations.
### Kinetic nature of the regime transition
We then focused on the kinetic nature of the transition between the reversible/pinning and topological unwinding regimes. In the case of domain walls, an irreversible creep motion occurs more frequently under a larger d.c. force38,39,40,41,42,43,44. When a pulsed or a.c. external force is applied, however, the pulse width or frequency dictates the onset of creep motion as well: at a given effective-force magnitude, domain-wall segments remain pinned and behave like an elastic solid on short timescales (or at high frequencies), whereas they begin to creep like a viscous fluid on longer time scales (or at low frequencies)1, 45,46,47,48. Such a dual nature depending on timescale or frequency may be described as a viscoelastic characteristic and can be qualitatively accounted for by considering that deformations exceeding the reversible/pinning regime cannot be induced instantaneously. Although this feature appears to be involved in a wide class of pinned electronic elastic objects, such a viscoelastic nature has not been explored in the skyrmion strings to date.
To address this issue, we investigated the decrease in the topological Hall signal for various pulse widths, t p, with a sufficiently large pulse magnitude, +8.2 × 106 A m–2 (Fig. 5a). As expected, relative to the case of long pulse widths, such as t p ≥ 25 ms, much less topological unwinding was observed for the shortest pulse width, 5 ms (for the apparent convergence of the Δρ yx profiles for t p ≥ 25 ms, see Supplementary Note 2). However, it should be emphasized that the low degree of topological unwinding for t p = 5 ms occurred not because the integrated pulse width (that is, the pulse number multiplied by each t p) was the shortest: as illustrated in Fig. 5b, even if the Δρ yx profiles are compared at a given integrated pulse width, the data for t p = 5 ms still exhibits the least topological unwinding. This finding suggests that the metastable SkS-L tends to remain in the reversible/pinning regime for a short-pulse application, whereas it is more likely to enter the topological unwinding regime for a longer-pulse application. This timescale-dependent dynamic transition is analogous to the viscoelastic characteristics accompanying the pinning-creep transition of domain-wall motion1, 45,46,47,48, again highlighting the key role of the pinning-creep transition of the segmented skyrmion strings at the onset of topological unwinding.
### Pulse width vs. critical current density
The timescale-dependent regime-transition of the metastable SkS-L suggests that the critical current density above which the topological unwinding manifests itself is a function of the pulse width. In estimating the critical current density for various pulse widths, we introduce the quantity F (:0 ≤ F ≤ 1):
$$F(n) \equiv 1 - {\rm{\Delta }}\rho {_{yx}}(n){\rm{/\Delta }}\rho {_{yx}}(0),$$
(1)
where Δρ yx(n) is a value measured after the positive in-plane current pulse is applied n times and Δρ yx(0) denotes a value after applying the writing pulse; thus, F(n) represents the unwound fraction of the metastable SkS-L after n-pulse applications, and F(n) = 0 and 1 correspond to the as-written SkS-L and fully unwounded non-topological state, respectively.
Figure 6a summarizes the results at 15 K after 200 pulse applications, F(n = 200), as a function of the current density, j, for various pulse widths, t p, showing the clear dependence of F on j and t p. In all cases, the F(n = 200)–j profiles (and also the F(n = 100)–j profiles: see Supplementary Fig. 6) are well described by a power law with a fixed exponent, F(n = 200)~j α with α = 3.4 (for F(n = 100), α = 3.5: see also Supplementary Fig. 6). This power-law behavior suggests that, in a strict sense, the critical current density is infinitesimally small; however, this consequence is consistent with the current understanding of creep motion, in which an infinitesimal force allows for creep motion with a finite probability as long as the temperature is finite38,39,40,41,42,43,44.
Nevertheless, we can conditionally derive a critical current density of a practical sense, above which a finite F(n) becomes experimentally appreciable: in view of the present experimental accuracy, we set this criterion as F(n) = 0.03 and label the (practical) critical current density with j c,n . Figure 6b displays j c,n = 100 and j c,n = 200 at 15 K as a function of pulse width; although j c,n = 200 is reasonably lower than j c,n = 100 at a given pulse width, a clear correlation between pulse width and critical current density can be seen for the both profiles, thus highlighting the viscoelastic characteristics at the onset of topological unwinding. Although under the present definition, the value of j c depends on the pulse number and pulse width, it can be safely concluded that j c in the limit of long pulse (t p → ∞) is on the order of 106 A m–2, in good agreement with the value reported for the thermodynamically stable SkS-L under d.c. currents14, 15.
### Power-law analysis of the pulse-width dependence
The j ct p profiles at 15 K shown in Fig. 6b are both described by a power law with nearly the same exponent: j c − j c(t p → ∞)~t p –1/δ with δ = 0.43 ± 0.05. The F(n)–j profiles at a lower temperature, 10 K, were also analyzed using power laws, but at relatively large n (n = 200 and 1000) because of the less pronounced topological unwinding (Supplementary Fig. 6); in this manner, we obtained α = 2.4–2.5 and δ = 0.50 ± 0.06 at 10 K (Supplementary Fig. 7), to be compared with α = 3.4–3.5 and δ = 0.43 ± 0.05 at 15 K. Thus, unlike the exponent α, the exponent δ appears to vary only weakly in the temperature range of 10–15 K. Although there are currently no numerical results to be compared, the value of δ would be a potential basis to test the microscopic model for the current-induced dynamics of the metastable SkS-L. At a minimum, the microscopic models for the depinning kinetics have been discussed in charge density waves by comparing the experimentally and theoretically derived δ values49,50,51,52.
## Discussion
We expect that the innately segmented skyrmion strings are likely to be relevant also to the current-induced dynamics of the thermodynamically stable SkS-L. Nevertheless, the consequence of the creep motion is expected to be crucially different between the metastable and thermodynamically stable cases: in a metastable SkS-L, the monopoles and antimonopoles move to eliminate the skyrmion string unless they are pinned, eventually lowering the system’s total free energy. In a thermodynamically stable SkS-L, by contrast, the topological unwinding is not triggered because the breakdown of the thermodynamically stable state inevitably increases the free energy. The current-induced dynamics of the thermodynamically stable SkS-L are therefore expected to involve the steady flow of the monopoles and antimonopoles, which may be accompanied by fluctuations in the emergent electric field27, 28.
We have also shown that the existing emergent magnetic (anti)monopoles are harmful when one tries to drive metastable skyrmions with an electric current; therefore, in the context of the skyrmion application, the device thickness must be chosen so that skyrmion strings (or cylinders) do not contain topological defects. In the thermo-equilibrium SkS-L phase, the order of the expected segment length is given as a × exp(ΔMP-AMP/k B T), where a is the lattice constant of the considered material and ΔMP-AMP is the pair-creation energy of the monopole and antimonopole. According to the numerical results27, ΔMP-AMP at the lowest temperature is ≈6 J for a simple cubic lattice, where J is the magnetic exchange energy and approximately equals to the magnetic transition temperature53; hence, for MnSi, ΔMP-AMP/k B ≈200 K at low temperatures. Thus, in the thermo-equilibrium SkS-L phase (≈27 K), the expected segment length is ~700 nm (or shorter, given that ΔMP-AMP may decrease at high temperatures). Because our sample thickness is ≈100 μm, one can expect that each quenched skyrmion string contains monopole-antimonopole pairs on the order of 100, provided that the topological defect density is frozen at the value of the thermo-equilibrium phase. The direct observation of a segmented skyrmion string remains a challenging issue, which may nevertheless provide useful information when designing a topological-defect-free skyrmion device.
## Methods
### Sample preparation and setup
A single crystal of MnSi was grown via the Czochralski method. The sample was cut and polished to a size of 2.5 × 1.1 × 0.1 mm3, with the largest surface normal to the <100> axis. The resistivity ratio ρ(300 K)/ρ(4.2 K) was ≈52. Gold current leads of 0.3 mm ϕ were attached to the sample and fixed with indium. The electrodes, e1 and e2, were constructed using carbon paste to achieve a high contact resistance, ≈10–15 Ω. The sample was mounted on a sapphire substrate in contact with a heat bath and fixed with varnish.
### Transport measurements
The Hall resistivity, ρ yx, was measured at 33 Hz with a low a.c. current excitation (≈7.97 × 104 A m–2) under a magnetic field parallel to the <100> axis using lock-in amplifiers (Stanford Research Systems, SR830) equipped with a transformer preamplifier (Stanford Research Systems, SR554). The Hall resistivity values presented here are antisymmetrized between the positive and negative magnetic fields. The pulse currents that were used to write the metastable SkS-L or to exert an effective force on the written metastable SkS-L were generated by a function generator (NF Corporation, WF1947) connected to a bipolar amplifier (NF Corporation, 4502A). Before applying the writing pulse to the electrode e1 at +0.249 T (or –0.249 T), we applied a field of 1T (or –1T) to enter the ferromagnetic state and erase any residue of the metastable SkS-L in the previous measurements. When measuring Δρ yx as a function of the in-plane pulse number, we waited 1 min after the last pulse was applied to ensure that the sample temperature was sufficiently equilibrated with the sample-holder temperature. When multiple pulses were applied between measurement points, we set the interval between successive two pulses to be 6 s.
### Micromagnetic simulation
The simulation was performed for a simple cubic lattice consisting of 60 × 30 × 100 magnetic moments with an open boundary condition in the z direction and periodic boundary conditions in the x and y directions. We considered the following model Hamiltonian:
$$\begin{array}{ccccc}\\ H =- J\mathop {\sum}\limits_{\boldsymbol{r}} {{{\boldsymbol{n}}_{\boldsymbol{r}}} \cdot \left( {{{\boldsymbol{n}}_{{\boldsymbol{r}} + {{\boldsymbol{e}}_x}}} + {{\boldsymbol{n}}_{{\boldsymbol{r}} + {{\boldsymbol{e}}_y}}} + {{\boldsymbol{n}}_{{\boldsymbol{r}} + {{\boldsymbol{e}}_z}}}} \right)} \\ + D\mathop {\sum}\limits_{\boldsymbol{r}} {\left( {{{\boldsymbol{n}}_{\boldsymbol{r}}} \times {{\boldsymbol{n}}_{{\boldsymbol{r}} + {{\boldsymbol{e}}_x}}} \cdot {{\boldsymbol{e}}_x} + {{\boldsymbol{n}}_{\boldsymbol{r}}} \times {{\boldsymbol{n}}_{{\boldsymbol{r}} + {{\boldsymbol{e}}_y}}} \cdot {{\boldsymbol{e}}_y} + {{\boldsymbol{n}}_{\boldsymbol{r}}} \times {{\boldsymbol{n}}_{{\boldsymbol{r}} + {{\boldsymbol{e}}_z}}} \cdot {{\boldsymbol{e}}_z}} \right)} \\ - h\mathop {\sum}\limits_{\boldsymbol{r}} {{n_{\{z,{\boldsymbol{r}}\}}} - {K_{{\rm{imp}}}}} \mathop {\sum}\limits_{{\boldsymbol{r}} \in {{\Lambda }}} {{{({n_{\{z,{\boldsymbol{r}\}}}})}^2},} \\ \end{array}$$
(2)
where J is the exchange interaction, D is the Dzyaloshinskii-Moriya interaction energy, h z is the magnetic field along the z direction, e x (or e y, e z) is the unit vector that connects with the nearest neighbor site along the x (or y, z) direction, n r is the unit vector of the local magnetic moment at site r, and n {z,r} is the z component of n r . The last term represents the impurity in the model: the easy axis anisotropy K imp was introduced at randomly selected sites, and Λ is the set of random numbers. In simulating the current-induced dynamics of the skyrmion string at zero temperature, we inserted the Hamiltonian into the following Landau–Lifshitz–Gilbert equation:
$$\frac{{\mathrm{d}{{\boldsymbol{n}}_{\boldsymbol{r}}}}}{{\mathrm{d}\it t}} = - \gamma \frac{{\mathrm{d}\it H}}{{\mathrm{d}{{\boldsymbol{n}}_{\boldsymbol{r}}}}} \times {{\boldsymbol{n}}_{\boldsymbol{r}}} + \alpha {{\boldsymbol{n}}_{\boldsymbol{r}}} \times \frac{{\mathrm{d}{{\boldsymbol{n}}_{\boldsymbol{r}}}}}{{\mathrm{d}\it t}} - ({\boldsymbol{j}} \cdot \nabla ){{\boldsymbol{n}}_{\boldsymbol{r}}} + \beta \left[ {{{\boldsymbol{n}}_{\boldsymbol{r}}} \times ({\boldsymbol{j}} \cdot \nabla ){{\boldsymbol{n}}_{\boldsymbol{r}}}} \right],$$
(3)
where j represents the (spin-polarized) electric current density. The units of non-dimensional time t and current j = |j| are 1/(γJ) and 2eγJ/(pa 2) (p: polarization of the magnet), respectively. We chose the following parameter set {J = 1.0, D = 0.2, K imp = 0.2, h = 0.018, α = β = 0.04, j = 0.04}. The density of the random impurity was set as 10%.
### Data availability
The data that support the findings of this study are available from the corresponding author on request. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8482617139816284, "perplexity": 1610.5176764919825}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296943746.73/warc/CC-MAIN-20230321193811-20230321223811-00131.warc.gz"} |
http://www.chegg.com/homework-help/questions-and-answers/cyclotron-particle-accelerator-sometimes-called-atom-smasher-popular-press-device-foraccel-q65371 | A cyclotron particle accelerator (sometimes called an“atom smasher” in the popular press) is a device foraccelerating charged particles, such as electrons and protons, tospeeds close to the speed of light. The basic design is quitesimple. The particle is bent in a circular path by a uniformmagnetic field. An electric field is pulsed periodically toincrease the speed of the particle. .The largest cyclotron in theUnited States is the Tevatron at Fermilab, near Chicago, Illinois.It is called a Tevatron because it can accelerate particles toenergies in the TeV range (1.00 = 1.00×1012 ). Its circumference is 6.40 , and it currently can produce a maximum energy of2.00 . In a certain medical experiment on the Tevatron,protons will be accelerated to energies of 1.25 and aimed at a tumor to destroy its cells.
a) How fast are these protons moving when they hit the tumor?(in m/s)
b) How strong must the magnetic field be to bend the protonsin the circle indicated? (in T) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9284984469413757, "perplexity": 2198.808578871346}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-27/segments/1435375098464.55/warc/CC-MAIN-20150627031818-00181-ip-10-179-60-89.ec2.internal.warc.gz"} |
https://codereview.stackexchange.com/questions/144684/check-repository-for-a-nested-entity | # Check repository for a nested entity
I have a Product entity and a ProductCategory entity. Given the Product entity, my application checks the database via a repository to see if the ProductCategory already exists. If the category is not found in the database, then the application should persist it.
Currently, I have this code in the service layer as follows:
public class ProductCategoryMapper implements DataMapper<ProductCategory> {
@NonNull
private final ProductCategoryRepository categoryRepository;
@Override
public void map(Product product) {
ProductCategory category = productCategoryRepository.findByProductTagAndMake(product);
if (category == null) {
category = productCategoryRepository.save(new ProductCategory(product.getTag(), product.getMake()));
}
product.setProductCategory(category);
}
}
But should this method be in the Product class as:
public void mapCategory(); // or perhaps setCategory();
This seems to be better OO but then the Product entity would have a reference to the repository (which I think is bad from a design / DDD perspective b/c the entity knows about repositories). Should the code stay in the service layer, be moved to the entity, or is there some other option?
It appears that this Product entity is meant to be a POJO. POJOs should be responsible only for holding the relevant data in memory to be accessed by, and possibly manipulated by, someone else.
In DDD, an aggregate is composed of a root entity (the Product) and one or more child entities (the ProductCategory).
Business logic that creates an aggregate is usually put into a Factory. The factory implementation would then be one that calls into the ProductCategoryRepository. That is, the setCategory method (or similar) would belong to the ProductFactory class. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3458711802959442, "perplexity": 3621.0481545181296}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195530246.91/warc/CC-MAIN-20190723235815-20190724021815-00461.warc.gz"} |
https://math.stackexchange.com/questions/2251776/positive-functions-with-positive-fourier-cosine-transforms | # Positive functions with positive Fourier cosine transforms
Are there any real-valued strictly positive functions besides the Gaussian function whose cosine transform is also strictly positive?
For instance with $F_c(e^{-x^2}) = \frac{e^{-\frac{\omega^2}{4}}}{\sqrt{2}}$, both sides are strictly positive, whereas with $f(x) = \begin{cases} 1, & -1<x<1 \\0, & \text{otherwise}\end{cases}$ which is strictly positive we get $F_c(f(x)) = \frac{\sqrt{\frac{2}{\pi}} \sin(\omega)}{\omega}$, which is not strictly positive.
Edit: by "positive" I actually meant non-negative, as in zero values are welcome too.
• There is $g(x) = (1-|x|) 1_{|x| < 1}$ which is compactly supported and whose Fourier transform is non-negative, and $f(x) = g(x)+g(\pi x)$ whose FT is strictly positive – reuns Apr 25 '17 at 17:33
• Sorry for having to show my lack of education, but what does $1_{|x| < 1}$ mean? – Michel Rouzic Apr 25 '17 at 17:46
• The function that is $1$ when $|x|<1$ and zero otherwise, also known as an indicator function – Chappers Apr 25 '17 at 17:47
• Otherwise, take $g$ compactly supported and let $f(x)= \int_{-\infty}^\infty \overline{g(-y)} g(x-y)dy$. Then $\hat{f}(\xi) = |g(\xi)|^2$ – reuns Apr 25 '17 at 17:53
• Oh I see, so that's a triangular function. I always knew its Fourier transform had ripples but never realised they weren't negative! The FT of the triangular function could possibly be the basis for an interesting filter (in signal/image processing). By the way clearly adding triangles of different widths starts giving you something a Gaussian function if their height decreases with the increased width, but what if you don't scale them differently like you did with $g(x)+g(\pi x)$? Because it seems that any function made from sums of triangles would be positive and have a positive FT too! – Michel Rouzic Apr 25 '17 at 18:13
## 3 Answers
How about $f(x)=\exp(-|x|)$?
We have $$\int_{-\infty}^\infty f(x)\cos tx= \int_0^\infty (e^{itx}+e^{-itx})e^{-x}=\frac1{1-it}+\frac1{1+it} =\frac2{1+t^2}.$$
• Yep looks like a good one. Does this function or its cosine transform $\frac{\sqrt{\frac{2}{π}}}{ω^2 + 1}$ have a name? – Michel Rouzic Apr 25 '17 at 17:36
By Bochner's theorem, a function $F$ is the Fourier transform of a positive function if and only if it is positive-definite, i.e. $$\sum_{1\leq i,j \leq n} \xi_i \bar{\xi}_j F(a_i-a_j) \geq 0$$ for any $n$, any set of reals $a_i$ and any complex numbers $\xi_i$. One certainly needs $f(0)>0$ and $\lvert f(x) \rvert \leq f(0)$ for this to happen (from the $n=1,2$ cases). Invoking this condition on both $F$ and its Fourier transform implies that $F$ and $\tilde{F}$ are both positive if and only if they are both positive-definite; hence the positive positive-definite functions are closed under Fourier transforms.
• If we look at semi positive-definite functions, then they are of the form $f(x)= \int_{-\infty}^\infty \overline{g(-y)} g(x-y)dy$ – reuns Apr 25 '17 at 17:55
• By applying the convolution theorem to $|f(k)|^2$, eh? – Chappers Apr 25 '17 at 18:05
This might be a little late.. but I just want to put this out here anyway:
All convex functions have positive Fourier-Cosine transform. This was proven in by E.O Tucker
Here is the link to the paper: On positivity of Fourier transforms | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.900344967842102, "perplexity": 439.94723670845366}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540490743.16/warc/CC-MAIN-20191206173152-20191206201152-00537.warc.gz"} |
http://www.hamradiolicenseexam.com/ham-radio-formulas-general-class-license-exam.htm | Formulas on the General Exam
This page contains all the formulas needed for the General class ham radio license exam. You might want to print out these formulas and review them just before entering the exam room, but leave this sheet in the car! Do not bring it into the exam room with you!
Prefix Symbol Value International System of Units (SI) giga- G 109 1,000,000,000 one billion mega- M 106 1,000,000 one million kilo- k 103 1,000 one thousand (none) (none) 100 1 one centi- c 10−2 .01 one one-hundredth milli- m 10−3 .001 one one-thousandth micro- µ 10−6 .000001 one one-millionth nano- n 10−9 .000000001 one one-billionth pico- p 10−12 .000000000001 one one-trillionth
Standing wave ratio:
$$SW\!R = \frac{highest\text{-}impedance}{lowest\text{-}impedance}$$
Length of 1/2 wavelength antenna:
$$Length~ \text{(in feet)} = \frac{468}{Frequency~ \text{(in MHz)}}$$
Length of 1/4 wavelength antenna:
$$Length~ \text{(in feet)} = \frac{234}{Frequency~ \text{(in MHz)}}$$
International System of Units (SI):
$$1~ \text{nF} = 10^{-3}~ \text{µF}$$
$$1~ \text{pF} = 10^{-3}~ \text{nF}$$
Equal-value resistors in series:
$$R_i = \frac{R_t}{n}$$
Equal-value resistors in parallel:
$$R_t = \frac{R_i}{n}$$
Resistors in parallel:
$$\frac{1}{R_t} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3}$$
Inductors in series:
$$L_t = L_1 + L_2$$
Equal-value inductors in parallel:
$$L_t = \frac {L_i}{n}$$
Capacitors in parallel:
$$C_t = C_1 + C_2 + C_3$$
Equal-value capacitors in series:
$$C_t = \frac {C_i}{n}$$
Capacitors in series:
$$\frac {1}{C_t} = \frac {1}{C_1} + \frac {1}{C_2}$$
Transformers:
$$E_s = E_p \times \left(\frac {N_s}{N_p} \right)$$
$$\frac {N_P}{N_S} = \sqrt{\frac {Z_P}{Z_S}}$$
RMS voltage:
$$V_P = \frac{V_{RMS}}{0.707}$$
$$V_{PP} = V_P \times 2$$
$$V_{RMS} = V_P \times 0.707$$
Power:
$$P = E \times I$$
$$P = \frac {E^2}{R}$$
$$P = I^2 \times R$$
$$E = \sqrt{P \times R}$$
Peak envelope power:
$$V_P = \frac{V_{PP}}{2}$$
$$V_{RMS} = V_P \times 0.707$$
$$PEP = \frac{{V_{RMS}}^2}{R}$$
Decibel math:
$$loss\text{-}\!factor = 10 ^ \left( \large \frac{-loss \text{-} in \text{-} db}{10} \right)$$
$$percent \text{-}loss = ( 1 - loss\text{-}\!factor ) \times 100\%$$
Frequency modulation:
$$bandwidth = 2 \times \left(D_{MAX} + M_{MAX}\right)$$
Upconverter:
$$multiplier = \frac {transmitted \text{-}frequency}{lower \text{-}frequency}$$
$$lower \text{-}frequency \text{-}maximum \text{-}deviation = \frac {transmitted \text{-}frequency \text{-}maximum \text{-}deviation}{multiplier}$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6751603484153748, "perplexity": 24811.22083959938}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610703514121.8/warc/CC-MAIN-20210118030549-20210118060549-00130.warc.gz"} |
https://cs.stackexchange.com/questions/85834/is-the-empty-string-a-terminal-symbol | # Is the empty string a terminal symbol?
I ask this question with regards to a grammar in Chosmky Normal Form. The definition states that the rules must be of the following forms:
1. A $\rightarrow$ BC
2. A $\rightarrow$ a
3. S $\rightarrow$ $\epsilon$
And A,B and C are non-terminal symbols, B and C are different from S and a is a terminal symbol. The definition also states that the last rule can only be present if the language of the grammar accepts the empty string (source). Now if $\epsilon$ is a terminal symbol, than this is a contradiction as the second rule can be transformed to S $\rightarrow$ $\epsilon$, seeing as A must not be different from S. This leads me to conclude that $\epsilon$ is not a terminal symbol, is this correct?
• $abc$ is a sequence of three non-terminals. $ab$ is a sequence of two non-terminals. $a$ is a sequence of one non-terminal. $\epsilon$ is a sequence of zero non-terminals. We should write "" (without quotes) for the sequence of zero non-terminals, but we use the $\epsilon$ notation for clarity. – chi Dec 23 '17 at 21:27
It's true that, in general, definitions don't include the empty string in the set of "terminals", as there's no need for that (e.g. the production rules for a context-free grammar are defined as a relation $V \rightarrow (V \cup \Sigma)^*$ - the star covers all productions of the form $A \rightarrow \epsilon$; in all other contexts, it can be omitted because it has no effect on concatenation).
Note, however, that in the case of a CNF grammar, you couldn't just make a simple convention for "terminals" to include the empty string and cut down to just the first two rules, because rules of the form $A \rightarrow \epsilon$ are not allowed for all non-terminal $A$, just for $S$.
• So in general $\epsilon$ is not considered a terminal symbol? – SBylemans Dec 23 '17 at 12:44
In fact, this is an issue that we have to address when defining the formal syntax of context-free grammars. Either we ask that $\epsilon \notin \Sigma$, or we encode $\epsilon$-rules as $A \to$ rather than as $A \to \epsilon$. There is a similar choice regarding the symbol $\to$: either we ask that $\to \notin \Sigma$, or we encode rules as pairs $(A,\alpha)$. There are of course other choices, such as allowing the "user" to choose the symbols standing for $\to$ and $\epsilon$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9164705276489258, "perplexity": 275.48621688781424}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107892710.59/warc/CC-MAIN-20201026234045-20201027024045-00380.warc.gz"} |
https://arxiv.org/list/math.NT/1606 | # Number Theory
## Authors and titles for math.NT in Jun 2016
[ total of 208 entries: 1-25 | 26-50 | 51-75 | 76-100 | ... | 201-208 ]
[ showing 25 entries per page: fewer | more | all ]
[1]
Title: Sign Changes of Coefficients and Sums of Coefficients of L-Functions
Journal-ref: Journal of Number Theory 177 (2017), 112-135
Subjects: Number Theory (math.NT)
[2]
Title: A note on Catalan numbers associated with p-adic integral on Zp
Authors: Taekyun Kim
Journal-ref: Proceedings of the Jangjeon Mathematical Society, Vol 19(2016), no. 3
Subjects: Number Theory (math.NT)
[3]
Title: Del Pezzo surfaces over finite fields and their Frobenius traces
Comments: 25 pages. Fixed various typos and improved exposition
Journal-ref: Math. Proc. Camb. Phil. Soc. 167 (2019) 35-60
Subjects: Number Theory (math.NT)
[4]
Title: A standard zero free region for Rankin-Selberg L-functions
Subjects: Number Theory (math.NT)
[5]
Title: Sums of multiplicative characters with additive convolutions
Subjects: Number Theory (math.NT); Combinatorics (math.CO)
[6]
Title: On the periodicity of irreducible elements in arithmetical congruence monoids
Journal-ref: Integers 17 (2017), #A38
Subjects: Number Theory (math.NT)
[7]
Title: Maass form twisted Shintani $\mathscr{L}$-functions
Authors: Bob Hough
Comments: Several references corrected and clarification to the relation to previous work
Subjects: Number Theory (math.NT)
[8]
Title: Witt vector rings and quotients of monoid algebras
Subjects: Number Theory (math.NT); Algebraic Geometry (math.AG)
[9]
Title: Polar harmonic Maass forms and their applications
Journal-ref: Abh. Math. Sem. Univ. Hamburg, vol. 86 (2016), pp. 213-233
Subjects: Number Theory (math.NT)
[10]
Title: Zero order estimates for Mahler functions
Authors: Michael Coons
Comments: 5 pages, version 2 has a few fixed typos
Subjects: Number Theory (math.NT)
[11]
Title: On the torsion of rational elliptic curves over quartic fields
Comments: In this new version we fix some errors in Table 5
Journal-ref: Math. Comp. 87 (2018) 1457-1478
Subjects: Number Theory (math.NT); Algebraic Geometry (math.AG)
[12]
Title: A note on Hardy's theorem
Authors: Usha K. Sangale
Comments: 9 pages; To appear in Hardy Ramanujan Journal
Subjects: Number Theory (math.NT)
[13]
Title: On the denominators of the Taylor coefficients of G-functions
Authors: S Fischler (LM-Orsay), T Rivoal (IF)
Subjects: Number Theory (math.NT)
[14]
Title: Enumerating submodules invariant under an endomorphism
Authors: Tobias Rossmann
Subjects: Number Theory (math.NT); Group Theory (math.GR); Rings and Algebras (math.RA)
[15]
Title: Existence of sublattice points in lattice polygons
Subjects: Number Theory (math.NT); Combinatorics (math.CO)
[16]
Title: Bounds on the number of vertices of sublattice-free lattice polygons
Subjects: Number Theory (math.NT)
[17]
Title: Applications of some exponential sums on prime powers: a survey
Journal-ref: Rivista di Matematica della Universita di Parma, volume 7, pages 19-37, 2016
Subjects: Number Theory (math.NT)
[18]
Title: Cesàro average in short intervals for Goldbach numbers
Comments: revised version; to appear in Proc. AMS
Journal-ref: Proc. A.M.S. 145 (2017), 4175-4186
Subjects: Number Theory (math.NT)
[19]
Title: Factoring Polynomials over Finite Fields using Drinfeld Modules with Complex Multiplication
Subjects: Number Theory (math.NT); Computational Complexity (cs.CC); Data Structures and Algorithms (cs.DS); Symbolic Computation (cs.SC)
[20]
Title: A Harder-Narasimhan theory for Kisin modules
Comments: 51 pages, 4 figures. To appear in Algebraic Geometry
Journal-ref: Algebraic Geometry 7, no. 6 (2020), 645-695
Subjects: Number Theory (math.NT); Algebraic Geometry (math.AG)
[21]
Title: G-bundles on the absolute Fargues-Fontaine curve
Subjects: Number Theory (math.NT); Algebraic Geometry (math.AG)
[22]
Title: Absolute real root separation
Journal-ref: American Mathematical Monthly, vol. 124, no. 10, pp. 930-936, dec. 2017
Subjects: Number Theory (math.NT)
[23]
Title: Congruence primes for automorphic forms on unitary groups and applications to the arithmetic of Ikeda lifts
Comments: 37 pages; slightly strengthened Theorem 3.5, added Remarks 3.6 and 8.1. Added section 9 with examples and made a few minor modifications throughout. To appear in Kyoto J. Math
Journal-ref: Kyoto J. Math. 60, no. 1 (2020), 179-217
Subjects: Number Theory (math.NT)
[24]
Title: Notes on isocrystals
Authors: Kiran S. Kedlaya
Comments: 32 pages; v5: Remark 5.14 updated; section 9 split and significantly expanded
Subjects: Number Theory (math.NT); Algebraic Geometry (math.AG)
[25]
Title: Suites récurrentes linéaires d'ordre 2 à divisibilité forte
Authors: A. Bauval | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7534229159355164, "perplexity": 6999.848477591989}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243989526.42/warc/CC-MAIN-20210514121902-20210514151902-00042.warc.gz"} |
https://diophantus.org/arxiv/0704.0967 | # diophantus
Hello, this is beta version of diophantus. If you want to report about a mistake, please, write to hello@diophantus.org
#### Cross-Layer Optimization of MIMO-Based Mesh Networks with Gaussian Vector Broadcast Channels
06 Apr 2007 cs.IT, cs.AR, math.IT arxiv.org/abs/0704.0967
Abstract. MIMO technology is one of the most significant advances in the past decade to increase channel capacity and has a great potential to improve network capacity for mesh networks. In a MIMO-based mesh network, the links outgoing from each node sharing the common communication spectrum can be modeled as a Gaussian vector broadcast channel. Recently, researchers showed that dirty paper coding'' (DPC) is the optimal transmission strategy for Gaussian vector broadcast channels. So far, there has been little study on how this fundamental result will impact the cross-layer design for MIMO-based mesh networks. To fill this gap, we consider the problem of jointly optimizing DPC power allocation in the link layer at each node and multihop/multipath routing in a MIMO-based mesh networks. It turns out that this optimization problem is a very challenging non-convex problem. To address this difficulty, we transform the original problem to an equivalent problem by exploiting the channel duality. For the transformed problem, we develop an efficient solution procedure that integrates Lagrangian dual decomposition method, conjugate gradient projection method based on matrix differential calculus, cutting-plane method, and subgradient method. In our numerical example, it is shown that we can achieve a network performance gain of 34.4% by using DPC.
# Reviews
There are no reviews yet. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7992048263549805, "perplexity": 582.0744354246024}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610704800238.80/warc/CC-MAIN-20210126135838-20210126165838-00364.warc.gz"} |
https://link.springer.com/chapter/10.1007%2F978-3-319-46487-9_11 | ECCV 2016: Computer Vision – ECCV 2016 pp 173-188
# On Volumetric Shape Reconstruction from Implicit Forms
• Li Wang
• Franck Hétroy-Wheeler
• Edmond Boyer
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9907)
## Abstract
In this paper we report on the evaluation of volumetric shape reconstruction methods that consider as input implicit forms in 3D. Many visual applications build implicit representations of shapes that are converted into explicit shape representations using geometric tools such as the Marching Cubes algorithm. This is the case with image based reconstructions that produce point clouds from which implicit functions are computed, with for instance a Poisson reconstruction approach. While the Marching Cubes method is a versatile solution with proven efficiency, alternative solutions exist with different and complementary properties that are of interest for shape modeling. In this paper, we propose a novel strategy that builds on Centroidal Voronoi Tessellations (CVTs). These tessellations provide volumetric and surface representations with strong regularities in addition to provably more accurate approximations of the implicit forms considered. In order to compare the existing strategies, we present an extensive evaluation that analyzes various properties of the main strategies for implicit to explicit volumetric conversions: Marching cubes, Delaunay refinement and CVTs, including accuracy and shape quality of the resulting shape mesh.
## Keywords
Point Cloud Voronoi Cell Implicit Representation Voronoi Tessellation Implicit Form
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Yan, D.M., Wang, W., Lévy, B., Liu, Y.: Efficient computation of clipped voronoi diagram for mesh generation. Comput. Aided Des. 45(4), 843–852 (2013) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8190674185752869, "perplexity": 20585.670043903752}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496669431.13/warc/CC-MAIN-20191118030116-20191118054116-00325.warc.gz"} |
https://ntnuopen.ntnu.no/ntnu-xmlui/browse?value=Semikoz,%20Dimitry%20V.&type=author | Now showing items 1-1 of 1
• #### Gamma-ray counterpart of the IceCube neutrinos
(Journal article; Peer reviewed, 2019)
A γ-ray excess at high Galactic latitudes starting at energies 300 GeV was recently discovered in the data of the Fermi telescope. The multi-TeV γ-ray emission found has spectral characteristics at both low and high Galactic ... | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8944272994995117, "perplexity": 8093.21163262827}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141181482.18/warc/CC-MAIN-20201125071137-20201125101137-00471.warc.gz"} |
https://www.physicsforums.com/threads/two-port-parameters-doubt.506053/ | # Two Port parameters doubt.
1. Jun 11, 2011
### dhruv.tara
1. The problem statement, all variables and given/known data
In feedback problems of amplifiers we often use H feedback in the voltage controlled voltage sources... The good thing about that is that they are connected in series parallel form and they are then to find the net h parameters we simply add the h parameters of the amplifier (taken alone) to the h parameters of the feedback network (taken alone) respectively.
I was wondering if there are exceptions to this rule... I mean we connect the amplifier to the feedback network then isn't there a possibility that the individual parameters kind of change, maybe because of loading or something alike... Or is it impossible to happen. Can you give me some proofs?
2. Relevant equations
3. The attempt at a solution
2. Jun 13, 2011 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9278683662414551, "perplexity": 908.1831663433187}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-40/segments/1474738660350.13/warc/CC-MAIN-20160924173740-00051-ip-10-143-35-109.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/can-someone-check-my-integral-real-quick.842891/ | # Can someone check my integral real quick ?
1. Nov 12, 2015
### qq545282501
1. The problem statement, all variables and given/known data
use a double integral to find the volume bounded by the paraboloid :$$z=4-x^2-y^2$$, xy-plane and inside a cylinder: $$x^2+y^2=1$$
2. Relevant equations
x=rcosθ y=rsinθ
3. The attempt at a solution
the radius of the area of integration is 1, since its determined by the cylinder only, and the cylinder has radius of 1.
the cylinder has an infinite z value, so Z is like like $$4-r^2- 0$$
so I got this:
$$\int_{θ=0}^{2π} \int_{r=0}^1 (4-r^2)r \, dr \, dθ$$
2. Nov 12, 2015
### Staff: Mentor
That's it.
When you actually get to where you're evaluating these integrals, rather than just setting them up, there are some shortcuts you can take. Due to the symmetry of the two bounding surfaces, you can find the volume in the first octant, and multiply that by 4 to get the entire volume. IOW, this:
$4 \int_{θ=0}^{π/2} \int_{r=0}^1 (4-r^2)r \, dr \, dθ$
3. Nov 12, 2015
### qq545282501
gotcha, thank you | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9819483757019043, "perplexity": 613.382348159795}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257647327.52/warc/CC-MAIN-20180320091830-20180320111830-00434.warc.gz"} |
http://offshoremechanics.asmedigitalcollection.asme.org/article.aspx?articleid=1457005 | 0
Ocean Engineering
# Nonlinear Crest, Trough, and Wave Height Distributions in Sea States With Double-Peaked Spectra
[+] Author and Article Information
Felice Arena
Department of Mechanics and Materials, ‘Mediterranea’ University of Reggio Calabria, Localita Feo di Vito, 89100 Reggio Calabria, Italyarena@unirc.it
C. Guedes Soares
Unit of Marine Technology and Engineering, Instituto Superior Técnico, Technical University of Lisbon, Avenida Rovisco Pais, 1049-001 Lisboa, Portugalguedess@mar.ist.utl.pt
J. Offshore Mech. Arct. Eng 131(4), 041105 (Sep 30, 2009) (8 pages) doi:10.1115/1.3160657 History: Received July 03, 2007; Revised May 25, 2008; Published September 30, 2009
## Abstract
The peak to trough distributions of nonlinear high sea waves in bimodal sea states in deep water are investigated. The statistical distribution of wave height is first analyzed by considering the Boccotti’s expression, where the parameters of the distribution are calculated for some bimodal spectra of sea states recorded in the Atlantic Ocean. The nonlinear crest and trough distributions are then obtained, particularizing for two peaked spectra the second-order Fedele and Arena expression, which depends on two parameters. The results have been finally validated by means of Monte Carlo simulations of second-order random waves with bimodal spectra.
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## Figures
Figure 1
Bimodal spectrum recorded at Sines (Portugal) in December 2000
Figure 2
Bimodal spectrum recorded at Sines (Portugal) in December 2000
Figure 3
Bimodal spectrum recorded in North Atlantic Ocean (see Ref. 1)
Figure 4
Bimodal spectrum recorded in North Atlantic Ocean (see Ref. 1)
Figure 5
Spectrum A. Distribution of crest-to-trough wave heights: Comparison among the Rayleigh distribution (Eq. 1), the theoretical complete distribution with K=1 (Eq. 2), and the data from simulations (upper panel: data of linear simulations; lower panel: data of nonlinear simulations).
Figure 6
Spectrum A. Upper panel: Comparison among the Rayleigh distribution (Eq. 8), the theoretical nonlinear distribution (Eq. 9), and the crest data from nonlinear simulations. Lower panel: Comparison among the Rayleigh distribution (Eq. 8), the theoretical nonlinear distribution (Eq. 10), and the trough data from nonlinear simulations.
Figure 7
Spectrum A. Comparison among the Rayleigh (Eq. 8) and the theoretical crest and trough distributions from linear simulations
Figure 8
Spectrum B. Distribution of crest-to-trough wave heights: Comparison among the Rayleigh distribution (Eq. 1), the theoretical complete distribution with K=1 (Eq. 2), and the data from simulations (upper panel: data of linear simulations; lower panel: data of nonlinear simulations).
Figure 9
Spectrum B. Upper panel: comparison among the Rayleigh distribution (Eq. 8), the theoretical nonlinear distribution (Eq. 9), and the crest data from nonlinear simulations. Lower panel: comparison among the Rayleigh distribution (Eq. 8), the theoretical nonlinear distribution (Eq. 10), and the trough data from nonlinear simulations.
Figure 10
Spectrum B. Comparison among the Rayleigh (Eq. 8) and the theoretical crest and trough distributions from linear simulations.
Figure 11
Spectrum C. Distribution of crest-to-trough wave heights: comparison among the Rayleigh distribution (Eq. 1), the theoretical complete distribution with K=1 (Eq. 2), and the data from simulations (upper panel: data of linear simulations; lower panel: data of nonlinear simulations).
Figure 12
Spectrum C. Upper panel: comparison among the Rayleigh distribution (Eq. 8), the theoretical nonlinear distribution (Eq. 9), and the crest data from nonlinear simulations. Lower panel: comparison among the Rayleigh distribution (Eq. 8), the theoretical nonlinear distribution (Eq. 10), and the trough data from nonlinear simulations.
Figure 13
Spectrum C. Comparison among the Rayleigh (Eq. 8) and the theoretical crest and trough distributions from linear simulations.
Figure 14
Spectrum D. Distribution of crest-to-trough wave heights: Comparison among the Rayleigh distribution (Eq. 1), the theoretical complete distribution and with K=1 (Eq. 2), and the data from simulations (upper panel: data of linear simulations; lower panel: data of nonlinear simulations).
Figure 15
Spectrum D. Upper panel: comparison among the Rayleigh distribution (Eq. 8), the theoretical nonlinear distribution (Eq. 9), and the crest data from nonlinear simulations. Lower panel: comparison among the Rayleigh distribution (Eq. 8), the theoretical nonlinear distribution (Eq. 10), and the trough data from nonlinear simulations.
Figure 16
Spectrum D. Comparison among the Rayleigh (Eq. 8) and the theoretical crest and trough distributions from linear simulations.
## Discussions
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Topic Collections | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9099242687225342, "perplexity": 6117.610336417176}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-26/segments/1529267864546.30/warc/CC-MAIN-20180622143142-20180622163142-00278.warc.gz"} |
https://codegolf.stackexchange.com/questions/12348/solitaire-no-win-states?noredirect=1 | # Solitaire no-win states [duplicate]
NOTE: SIMILIAR TO Solitaire Dreams - Creating a winnable solitaire starting hand
Find a minimum of 5 deck orders where if the cards were dealt out would create a game of Klondike Solitaire where there is absolutely no possible winning state. Assume the game is 3 card draw, infinite times through the deck.
As always, the shorter the program the better.
• Solutions to Solitaire Dreams - Creating a winnable solitaire starting hand could be edited into solutions to the core of this with one character change, and making them repeat 5 times doesn't add anything. – Peter Taylor Aug 21 '13 at 7:38
• @PeterTaylor given that the only answer given to the duplicate question is also a cheating one, I don't think it is obvious this is actually a duplicate. – John Dvorak Aug 21 '13 at 7:53
# J, 37 (or 0; see below) characters
(i.5)A.(52\$'cdsh'),.4#'kqajt98765432'
For a much better view, prepend ,"2 and change the suits to uppercase. For an even better view, prepend ,"2' ',"1 instead. For more decks, change i.5 to a higher value, up to at least 24 factorial (6.2*10^23).
The trick here is twofold: Make the piles solid (enough) with (enough) aces built safe within, and to do that easily. If we deal the standard unshuffled deck, there is one rank that is never exposed. Let's move the aces there. There are several possible moves depending on the color assignment, but in order to prevent exposing the easy ace, order the colors such that this move is not possible. We are dealt this tableau (black colors in uppercase):
kC kd kS kh qC qd qS
qh aC ad aS ah jC
jd jS jh tC td
tS th 9C 9d
9S 9h 8C
8d 8S
8h
The only moves possible are
• qh-kC exposing kd
• tS-jd/jS-qh freeing diamonds up to 8d (if the stock is good)
• 8h-9S exposing 8S
• 8d-foundation/9h-tS or 8d-9S/9h-tS exposing 9C.
When these moves are performed, we're left with this solid tableau:
kC kd kS kh qC qd qS
qh aC aS ah jC
jS jd jh tC td
tS th 9C 9d
9h 9S 8C
8h 8S
The eight of hearts can be moved between the two black nines and the cards from the deck can be stacked on top, but no more aces can be freed.
Now, we can replace 8h, 8S and even 8h with a different card in the the stock and the game stays unwinnable. This pushes the number of known unwinnable decks up to 27! at least. Removing 8C opens up additional moves, but I believe the game is still unwinnable.
Note that if merely discovery is sufficient, then my score is zero as I didn't need a computer to verify the unwinnability of these 27! decks.
• Or, if you want to be especially evil, find a solution involving every draw-three player's nightmare - an ace on the 1st, 4th, 7th, and 10th cards in the stockpile. – Joe Z. Aug 22 '13 at 13:12 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5099839568138123, "perplexity": 4162.4578808153265}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347409337.38/warc/CC-MAIN-20200530133926-20200530163926-00187.warc.gz"} |
https://stats.stackexchange.com/questions/389222/how-to-forecast-individual-customers-spend-for-millions-of-customers | # How to forecast individual customer's spend (for millions of customers)?
Which forecasting model fits better to forecast the customers spend in the next upcoming visit? We have millions of customers, so ARIMA or any other time series modeling for each of the customers is not feasible (computationally).
Built Linear model (using a different level of moving average terms and other independent variables) and the average model (average spend per visit in the last X visits or time period). The performance of the linear model is similar to that of average model. How can I improve the linear model or build a better forecasting model?
Sample data:
Customer Visit Date Spend
1 1/21/2018 302
2 1/21/2018 308
3 1/23/2018 2112
4 1/35/2018 123
1 2/14/2018 234
1 2/16/2018 534
2 3/4/2018 1254
3 6/6/2018 854
1 6/2/2018 150
1 6/8/2018 720
2 9/9/2018 440
4 12/12/2018 323
3 12/15/2018 445
1 12/16/2018 660
1 as_of_today ?
2 as_of_today ?
3 as_of_today ?
4 as_of_today ?
Edit on 2019-01-31: I am not looking to forecast individually for each of the customers. I did segment the customers and built the linear models for each segment. However, want to build a better model than a linear model. So looking if there are any better forecasting techniques that can help me.
• Do you really need individual forecast for each one of the millions of customers? For what purpose will these forecast be used? Maybe start with segmentation, time-series clustering, ... and then maybe individual forecasts for only the most important? – kjetil b halvorsen Jan 26 '19 at 18:56
• I am not looking to forecast individually for each of the customers. I did segment the customers and built the linear models for each segment. However, want to build a better model than a linear model. So looking if there are any better forecasting techniques that can help me. – ML101 Jan 29 '19 at 18:33
• Please add this new information as an edit to the OP (original post). But without more details I doubt anybody will have much to say – kjetil b halvorsen Jan 29 '19 at 20:15
• I'm a little confused. Are you interested in when the customer will return, how much the individual will spend, or both? – Demetri Pananos Feb 1 '19 at 3:11
• @DemetriPananos I am interested only in how much will the customer spend. – ML101 Feb 2 '19 at 1:27 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.21093954145908356, "perplexity": 1574.3925902092856}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875148375.36/warc/CC-MAIN-20200229022458-20200229052458-00162.warc.gz"} |
http://math.stackexchange.com/questions/280895/function-field-has-infinitely-many-valuations/283256 | # Function field has infinitely many valuations.
Suppose we have a field $K$ which is a finite algebraic extension of the field $\mathbb{C}(X)$. Can you give me an argument that $K$ admits infinitly many discrete valuations?
-
Let $a$ be a complex number. $\mathbb{C}(X)$ has a discrete valuation at $X-a$. $K$ has a valuation extending it.
-
How can I extend this? – max Jan 17 '13 at 18:27
Or alternatively: What is an argument, that i can really extend these valuations? – max Jan 17 '13 at 18:42
Let $R$ be the integral closure of $\mathbb{C}[X]$ in $K$. Then by the Lying-over-Theorem for every $(X-a)$ there exists a prime $P$ of $R$ lying over $(X-a\mathbb{C}[X]$. Since $R$ is a Dedekind domain (Krull-Akizuki), the local ring $R_P$ is a discrete valuation ring. – Hagen Jan 21 '13 at 7:06
I think you can use one idea that for a given field $k$, $k[x]_{(x - a)}$ is a DVR for every $a\in k$ and choose $k = \mathbb C$. Now, you can extend from $\mathbb C(x)$ to any algebraic extension, which is again DVR.
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http://www.ck12.org/geometry/Parallelogram-Classification/lesson/Parallelogram-Classification-Intermediate/r13/ | <meta http-equiv="refresh" content="1; url=/nojavascript/">
You are viewing an older version of this Concept. Go to the latest version.
# Parallelogram Classification
%
Progress
Practice Parallelogram Classification
Progress
%
Parallelogram Classification
What if you were designing a patio for you backyard? You decide to mark it off using your tape measure. Two sides are 21 feet long and two sides are 28 feet long. Explain how you would only use the tape measure to make your patio a rectangle. After completing this Concept, you'll be able to answer this question using properties of special parallelograms.
### Guidance
Rectangles, rhombuses (the plural is also rhombi) and squares are all more specific versions of parallelograms.
Rectangle Theorem: A quadrilateral is a rectangle if and only if it has four right (congruent) angles.
Rhombus Theorem: A quadrilateral is a rhombus if and only if it has four congruent sides.
Square Theorem: A quadrilateral is a square if and only if it has four right angles and four congruent sides.
From the Square Theorem, we can also conclude that a square is a rectangle and a rhombus .
Recall that diagonals in a parallelogram bisect each other . Therefore, the diagonals of a rectangle, square and rhombus also bisect each other. The diagonals of these parallelograms also have additional properties.
##### Investigation: Drawing a Rectangle
Tools Needed: pencil, paper, protractor, ruler
1. Draw two lines on either side of your ruler, to ensure they are parallel. Make these lines 3 inches long.
2. Remove the ruler and mark two $90^\circ$ angles, 2.5 inches apart on the bottom line drawn in Step 1. Then, draw the angles to intersect the top line. This will ensure that all four angles are $90^\circ$ . Depending on your ruler, the sides should be 2.5 inches and 1 inch.
3. Draw in the diagonals and measure them. What do you discover?
Theorem: A parallelogram is a rectangle if and only if the diagonals are congruent.
##### Investigation: Drawing a Rhombus
Tools Needed: pencil, paper, protractor, ruler
1. Draw two lines on either side of your ruler, to ensure they are parallel. Make these lines 3 inches long.
2. Remove the ruler and mark a $50^\circ$ angle, at the left end of the bottom line drawn in Step 1. Draw the other side of the angle and make sure it intersects the top line. Measure the length of this side.
3. The measure of the diagonal (red) side should be about 1.3 inches (if your ruler is 1 inch wide). Mark this length on the bottom line and the top line from the point of intersection with the $50^\circ$ angle. Draw in the fourth side. It will connect the two endpoints of these lengths.
4. By the way we drew this parallelogram; it is a rhombus because all four sides are 1.3 inches long. Draw in the diagonals.
Measure the angles created by the diagonals : the angles at their point of intersection and the angles created by the sides and each diagonal. You should find the measure of 12 angles total. What do you discover?
Theorem: A parallelogram is a rhombus if and only if the diagonals are perpendicular.
Theorem: A parallelogram is a rhombus if and only if the diagonals bisect each angle.
We know that a square is a rhombus and a rectangle. So, the diagonals of a square have the properties of a rhombus and a rectangle.
#### Example A
What type of parallelogram are the ones below?
a)
b)
a) All sides are congruent and one angle is $135^\circ$ , meaning that the angles are not congruent. By the Rhombus Theorem, this is a rhombus.
b) This quadrilateral has four congruent angles and all the sides are not congruent. By the Rectangle Theorem, this is a rectangle.
#### Example B
Is a rhombus SOMETIMES, ALWAYS, or NEVER a square? Explain your reasoning.
A rhombus has four congruent sides, while a square has four congruent sides and angles. Therefore, a rhombus is only a square when it also has congruent angles. So, a rhombus is SOMETIMES a square.
#### Example C
List everything you know about the square $SQRE$ .
A square has all the properties of a parallelogram, rectangle and rhombus.
Properties of Parallelograms Properties of Rhombuses Properties of Rectangles
• $\overline{SQ} \ || \ \overline{ER}$
• $\overline{SQ} \cong \overline{ER} \cong \overline{SE} \cong \overline{QR}$
• $\angle SER \cong \angle SQR \cong \angle QSE \cong \angle QRE$
• $\overline{SE} \ || \ \overline{QR}$
• $\overline{SR} \perp \overline{QE}$
• $\overline{SR} \cong \overline{QE}$
• $\overline{SQ} \cong \overline{ER}$
• $\angle SEQ \cong \angle QER \cong \angle SQE \cong \angle EQR$
• $\overline{SA} \cong \overline{AR} \cong \overline{QA} \cong \overline{AE}$
• $\overline{SE} \cong \overline{QR}$
• $\angle QSR \cong \angle RSE \cong \angle QRS \cong \angle SRE$
• $\overline{SA} \cong \overline{AR}$
• $\overline{QA} \cong \overline{AE}$
• $\angle SER \cong \angle SQR$
• $\angle QSE \cong \angle QRE$
Watch this video for help with the Examples above.
#### Concept Problem Revisited
In order for the patio to be a rectangle, first the opposite sides must be congruent. So, two sides are 21ft and two are 28 ft. To ensure that the parallelogram is a rectangle without measuring the angles, the diagonals must be equal. You can find the length of the diagonals by using the Pythagorean Theorem.
$d^2&=21^2+28^2=441+784=1225\\d& = \sqrt{1225}=35 \ ft$
### Vocabulary
A parallelogram is a quadrilateral with two pairs of parallel sides.
A quadrilateral is a rectangle if and only if it has four right (congruent) angles:
A quadrilateral is a rhombus if and only if it has four congruent sides:
A quadrilateral is a square if and only if it has four right angles and four congruent sides.
### Guided Practice
1. Is a rectangle SOMETIMES, ALWAYS, or NEVER a parallelogram? Explain why.
2. Is a rhombus SOMETIMES, ALWAYS, or NEVER equiangular? Explain why.
3. Is a quadrilateral SOMETIMES, ALWAYS, or NEVER a pentagon? Explain why.
1. A rectangle has two sets of parallel sides, so it is ALWAYS a parallelogram.
2. Any quadrilateral, including a rhombus, is only equiangular if all its angles are $90^\circ$ . This means a rhombus is SOMETIMES equiangular, only when it is a square.
3. A quadrilateral has four sides, so it will NEVER be a pentagon with five sides.
### Practice
1. $RACE$ is a rectangle. Find:
1. $RG$
2. $AE$
3. $AC$
4. $EC$
5. $m \angle RAC$
2. $DIAM$ is a rhombus. Find:
1. $MA$
2. $MI$
3. $DA$
4. $m \angle DIA$
5. $m \angle MOA$
3. Draw a square and label it $CUBE$ . Mark the point of intersection of the diagonals $Y$ . Find:
1. $m \angle UCE$
2. $m \angle EYB$
3. $m \angle UBY$
4. $m \angle UEB$
For questions 4-12, determine if the quadrilateral is a parallelogram, rectangle, rhombus, square or none. Explain your reasoning.
For problems 13-15, find the value of each variable in the figures.
For questions 16-19 determine if the following are ALWAYS, SOMETIMES, or NEVER true. Explain your reasoning.
1. A rectangle is a rhombus.
2. A square is a parallelogram.
3. A parallelogram is regular.
4. A square is a rectangle. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 41, "texerror": 0, "math_score": 0.5864608287811279, "perplexity": 661.67480715367}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-11/segments/1424936462577.56/warc/CC-MAIN-20150226074102-00208-ip-10-28-5-156.ec2.internal.warc.gz"} |
https://themes.gohugo.io/theme/hugo-flex/page/2/ | ## Math Typesetting
Mathematical notation in a Hugo project can be enabled by using third party JavaScript libraries.
In this example we will be using KaTeX
• Create a partial under /layouts/partials/math.html
• Within this partial reference the Auto-render Extension or host these scripts locally.
• Include the partial in your templates like so:
{{ if or .Params.math .Site.Params.math }}
{{ partial "math.html" . }}
{{ end }}
• To enable KaTex globally set the parameter math to true in a project’s configuration
• To enable KaTex on a per page basis include the parameter math: true in content files
Note: Use the online reference of Supported TeX Functions
### Examples
Inline math: $$\varphi = \dfrac{1+\sqrt5}{2}= 1.6180339887…$$
Block math: $$\varphi = 1+\frac{1} {1+\frac{1} {1+\frac{1} {1+\cdots} } }$$
## Emoji Support
Emoji can be enabled in a Hugo project in a number of ways.
The emojify function can be called directly in templates or Inline Shortcodes.
To enable emoji globally, set enableEmoji to true in your site’s configuration and then you can type emoji shorthand codes directly in content files; e.g.
The Emoji cheat sheet is a useful reference for emoji shorthand codes.
N.B. The above steps enable Unicode Standard emoji characters and sequences in Hugo, however the rendering of these glyphs depends on the browser and the platform. To style the emoji you can either use a third party emoji font or a font stack; e.g.
.emoji {
font-family: Apple Color Emoji, Segoe UI Emoji, NotoColorEmoji, Segoe UI Symbol, Android Emoji, EmojiSymbols;
} | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 2, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.45566704869270325, "perplexity": 18956.479228600565}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618039526421.82/warc/CC-MAIN-20210421065303-20210421095303-00301.warc.gz"} |
http://mathhelpforum.com/geometry/207136-prove-question-print.html | Prove question
• Nov 9th 2012, 05:45 PM
crossfire
Prove question
The radius of circle ABC, centre B is r1.
The radius of circle CDE, centre D is r2.
For the diagram above PROVE that AC/CE = r1/r2
:l
• Nov 9th 2012, 05:45 PM
crossfire
1 Attachment(s)
Re: Prove question
This is a picture
• Nov 9th 2012, 06:23 PM
richard1234
Re: Prove question
Hint: There are some similar triangles in the diagram...
• Nov 9th 2012, 06:32 PM
jakncoke
1 Attachment(s)
Re: Prove question
How about this pic attached. $\frac{\sqrt(2)*r1}{\sqrt(2)*r2} = \frac{r1}{r2}$
• Nov 9th 2012, 06:43 PM
crossfire
Re: Prove question
Jakncoke, I dont quite understand where and how you got those figures could you please explain?
• Nov 9th 2012, 07:11 PM
richard1234
Re: Prove question
@jakncoke, that's only a specific case (for right isosceles triangles). It does generalize, using similarity.
• Nov 9th 2012, 08:57 PM
jakncoke
Re: Prove question
yea my bad, i wasn't thinking. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 1, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.902823805809021, "perplexity": 17269.23904319477}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988719960.60/warc/CC-MAIN-20161020183839-00184-ip-10-171-6-4.ec2.internal.warc.gz"} |
http://kullabs.com/classes/subjects/units/lessons/notes/3 | Energy
On completion of this lesson, students should be able to:
• Define energy and fuel and describe their sources.
• Differentiate between energy and its source.
• Explain why sun is ultimate source of energy.
• Describe solar energy with respect to nuclear energy.
• Describe about energy crisis.
• Describe alternate sources of energy and their importance.
• Measures adopted for energy conservation.
Introduction to Energy
Energy is the capacity of doing work. Whenever an object is capable of doing work. We are capable to do any kind of work only if we have some energy. This note has short introduction on energy and its types.
Non-Renewable Sources Of Energy
The sources of energy, which can not be replaced quickly or another times if it is used once is called non renewable source of energy. This note provides an information about different types of nonrenewable natural resources.
Renewable Sources of Energy
The sources of energy, which can never be exhausted and can be replaced quickly if it is used once is called renewable source of energy. This note provides information on different types of renewable natural resources of energy. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9405565857887268, "perplexity": 1046.461659255715}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-39/segments/1537267162385.84/warc/CC-MAIN-20180925202648-20180925223048-00199.warc.gz"} |
https://artofproblemsolving.com/wiki/index.php?title=1972_AHSME_Problems&diff=prev&oldid=87162 | # Difference between revisions of "1972 AHSME Problems"
## Problem 1
The lengths in inches of the three sides of each of four triangles , and are as follows:
Of these four given triangles, the only right triangles are
## Problem 2
If a dealer could get his goods for % less while keeping his selling price fixed, his profit, based on cost, would be increased to % from his present profit of %, which is
## Problem 3
If where , then is equal to
## Problem 4
The number of solutions to , where is a subset of is
## Problem 5
From among those which have the greatest and the next to the greatest values, in that order, are
## Problem 6
If , then the value of is
## Problem 7
If , then is equal to
## Problem 8
If where and are real, then
## Problem 9
Ann and Sue bought identical boxes of stationery. Ann used hers to write -sheet letters and Sue used hers to write -sheet letters. Ann used all the envelopes and had sheets of paper left, while Sue used all of the sheets of paper and had envelopes left. The number of sheets of paper in each box was
## Problem 10
For real, the inequality is equivalent to
## Problem 11
The value(s) of for which the following pair of equations may have a real common solution, are
## Problem 12
The number of cubic feet in the volume of a cube is the same as the number of square inches in its surface area. The length of the edge expressed as a number of feet is
## Problem 13
Inside square (See figure) with sides of length inches, segment is drawn where is the point on which is inches from . The perpendicular bisector of is drawn and intersects , and at points , and respectively. The ratio of segment to is
## Problem 14
A triangle has angles of and . If the side opposite the angle has length , then the side opposite the angle has length
## Problem 15
A contractor estimated that one of his two bricklayers would take hours to build a certain wall and the other hours. However, he knew from experience that when they worked together, their combined output fell by bricks per hour. Being in a hurry, he put both men on the job and found that it took exactly 5 hours to build the wall. The number of bricks in the wall was
## Problem 16
There are two positive numbers that may be inserted between and such that the first three are in geometric progression while the last three are in arithmetic progression. The sum of those two positive numbers is
## Problem 17
A piece of string is cut in two at a point selected at random. The probability that the longer piece is at least x times as large as the shorter piece is
## Problem 18
Let be a trapezoid with the measure of base twice that of base , and let be the point of intersection of the diagonals. If the measure of diagonal is , then that of segment is equal to
## Problem 19
The sum of the first terms of the sequence in terms of is
## Problem 20
If where and , then is equal to
## Problem 21
If the sum of the measures in degrees of angles and in the figure above is , then is equal to
## Problem 22
If are imaginary roots of the equation where , and are real numbers, then in terms of and is
## Problem 23
The radius of the smallest circle containing the symmetric figure composed of the 3 unit squares shown above is
## Problem 24
A man walked a certain distance at a constant rate. If he had gone mile per hour faster, he would have walked the distance in four-fifths of the time; if he had gone mile per hour slower, he would have been hours longer on the road. The distance in miles he walked was
## Problem 25
Inscribed in a circle is a quadrilateral having sides of lengths , and taken consecutively. The diameter of this circle has length
## Problem 26
In the circle above, is the midpoint of arc and segment is perpendicular to chord at . If the measure of chord is and that of segment is , then segment has measure equal to
## Problem 27
If the area of is square units and the geometric mean (mean proportional) between sides and is inches, then is equal to
## Problem 28
A circular disc with diameter is placed on an checkerboard with width so that the centers coincide. The number of checkerboard squares which are completely covered by the disc is
## Problem 29
If for , then in terms of is
## Problem 30
A rectangular piece of paper 6 inches wide is folded as in the diagram so that one corner touches the opposite side. The length in inches of the crease L in terms of angle is
## Problem 31
When the number is divided by , the remainder in the division is
## Problem 32
Chords and in the circle above intersect at E and are perpendicular to each other. If segments , and have measures , and respectively, then the length of the diameter of the circle is
## Problem 33
The minimum value of the quotient of a (base ten) number of three different non-zero digits divided by the sum of its digits is
## Problem 34
Three times Dick's age plus Tom's age equals twice Harry's age. Double the cube of Harry's age is equal to three times the cube of Dick's age added to the cube of Tom's age. Their respective ages are relatively prime to each other. The sum of the squares of their ages is
## Problem 35
Equilateral triangle (see figure) with side of length inches is placed inside square with side of length inches so that is on side . The triangle is rotated clockwise about , then , and so on along the sides of the square until returns to its original position. The length of the path in inches traversed by vertex is equal to | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8922432065010071, "perplexity": 708.4661195208795}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046154053.17/warc/CC-MAIN-20210731043043-20210731073043-00491.warc.gz"} |
https://cs.stackexchange.com/questions/143827/equivalence-between-lambda-calculus-and-recursive-functions | # Equivalence between $\lambda$-calculus and recursive functions
I have two related questions:
1. Do you know of any good reference to the recursive function / lambda-calculus equivalence in terms of computability, including proofs?
2. Do you know of any reference to subclasses of computable layers in lambda-calculus, like you have in recursion theory? It looks like you can't "dumb down" lambda-calculus but I'm not sure about that. And if we can't "dumb it down" to less computable classes, I'd love some reference to why this is so.
• Although the questions are somewhat related, it might be better to split them. Sep 10, 2021 at 17:08
• For 1., see e.g. J. Hindley & J. Seldin (2008), Lambda Calculus and Combinators: An introduction, chapter 4. Sep 10, 2021 at 18:13 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.36780810356140137, "perplexity": 824.7582342364046}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662521883.7/warc/CC-MAIN-20220518083841-20220518113841-00166.warc.gz"} |
https://codereview.stackexchange.com/questions/186525/optimized-fizzbuzz-in-brainfuck | Optimized FizzBuzz in brainfuck
While looking for brainfuck related things, I came across Simon Forsberg's FizzBuzz in Brainfuck and cheekily commented a link to my own brainfuck FizzBuzz answer over on PPCG. He suggested I should post my own Code Review question with a detailed explanation.
First, the code (350 bytes):
+[-[>+<<]>-]>--[>+>++>++>++++++>+>>>++++++<<<[<]>-
]<+++++[>+>+>->>->++>+>>--[<<]>-]>[>]<--<->>>[<<-[
<]<[>+++>+<<.<.<..[<]<]>>-[<<]>[<+++++>.>.>..[>>>]
<<+[<]]>[>>>]<<[[-]>>]>[>++++++++++[->++++++++++>+
<<]<[->+>-<<]>>++[>[>>>]<[>++++++++++>+>]<<-<-]+++
++++++>[-<->]<[->+<]>>[>]++++++++[-<++++++<++++++>
>]<<<[>[-]]>[>]<[.[-]<]<[-<+>]>]++++++++++.[-]<<-]
Try it online!
This can be split into three sections:
• Tape generation: Sets up the tape in the correct format
• While looping over 100 numbers:
• Checking the number: Checks if the number is divisible by 3 or 5, and printing Fizz and/or Buzz if so.
• Printing the number: Only if it isn't a FizzBuzz number
Tape Setup:
• Cell 3: The counter for the "Buzz" section
• Cell 4 through 8: These are the ascii values for "BuziF", a compact way of representing both "Fizz" and "Buzz".
• Cell 9: The counter for the "Fizz" section
• Cell 11: The overall counter to keep track of the 100 numbers
Brainfuck code:
Generates the number 61:
+[-[>+<<]>-]>--
This is taken from the Esolangs brainfuck constants page at https://esolangs.org/wiki/Brainfuck_constants
Sets all the cells to values very close to the needed ones
Basically multiplies 61 by various values (going over 255 wraps around to 0)
[>+>++>++>++++++>+>>>++++++<<<[<]>-]
Tape looks like:
0 0' 61 122 122 110 61 0 0 110
It needs to be:
0 5 66 117 122 105 70 3 0 100
Notice that (almost) all of these values are off by multiples of 5 so we increment a cell to 5
<+++++
And add/subtract 5s from each value
[>+>+>->>->++>+>>--[<<]>-]
Leaving the tape as:
0' 5 66 117 122 105 71 5 0 100
We make some final changes to get the desired cells
>[>]<--<->>>
Before leaving the memory pointer on the counter
Inside the Loop:
Checking if Fizz/Buzz
Both the Fizz and Buzz counters are initially set to 5 and 3 respectively. At each iteration of the loop, both counters are decremented. If either reach 0, their respective string is printed and resets the counter. It also sets a check for later to not print the number. Here's a python representation of this section of the code.
fizz = 3
buzz = 5
for i in range(1,101):
check = False
fizz -= 1
buzz -= 1
if fizz == 0:
print("Fizz",end='')
fizz = 3
check = True
if buzz == 0:
print("Buzz",end='')
buzz = 5
check = True
if not check:
print(i,end='')
print()
The relevant brainfuck section is:
Tape Format:
0 BCounter "BuziF" FCounter Check 0 Counter
<<- Decrement Fizz counter
[<]<[ If Fizz counter == 0
>+++ Reset counter
>+<< Increment check cell
.<.<.. Print "Fizz"
[<]<]
>>- Decrement Buzz counter
[<<]>[ If Buzz counter == 0
<+++++ Reset counter
>.>.>.. Print "Buzz"
[>>>]<<+ Increment check cell
[<]]
Printing the number
If the FizzBuzz check is empty, we need to print the number as an actual string. Since brainfuck doesn't have a way to convert a cell value to a printed number (surprise surprise), we need to convert the counter to two ASCII values (not three, since 100 is "Buzz") representing the number.
However, the counter is counting down from 100, we first need to subtract it from 100. Then we get the number modulo 10, which leaves us the tens and singles in different cells. Before printing though, we need to check whether the tens digit is 0, in which case we remove it. Then we add 48 to the numbers to convert it to the ASCII value of the number and print them. Here's some more python code:
def printNumber(n):
#Only works for numbers between 0 and 100
tens = n//10
singles = n%10
if tens != 0:
print(chr(tens+48), end='')
print(chr(singles+48), end='')
The relevant brainfuck code:
If the number check is 0 (reset the cell if not)
>[>>>]<<[[-]>>]>
[
Tape looks like:
BuziF c 0 100-N' 0 where 100-N is the counter and N is the number
We won't use anything left of the 100-N
Generate the number 100 and the number 10
>(10++++++++++)[->(10++++++++++)>+<<]
Tape: 0 100-N 0' 100 10
Subtract 100-N from 100 while keeping a copy of the 100-N
<[->+>-<<]
And increment N by 2 to counter some modulo stuff
>>++
Tape: 0 0 100-N N+2' 10 0
[ While N
Tape: 0 0 100-N N' Modulo Quotient 0;
>[>>>]< If the modulo is 0:
[>++++++++++>+>] Reset the modulo to 10 and increment the Quotient
<<-<- Decrement both N and the modulo
]
Tape: 0 0 100-N 0' 9-single tens
Subtract the singles cell from 10
+++++++++>[-<->]<[->+<]>>[>]
Tape: 0 0 100-N 0 single tens 0'
If the tens cell is 0:
Tape: 0 0 100-N 0 single 0'
(8++++++++)[-<(6++++++)<(6++++++)>>]
Tape: 0 0 100-N 0 single tens 0'
OR
Tape: 0 0 100-N 48 single 0'
If the tens cell was 0 reset the 48 cell
<<<[>[-]]
Tape: 0 0 100-N 0 single tens 0'
OR
Tape: 0 0 100-N 0 single 0'
Print the tens (if needed) and singles while resetting the cells
>[>]<[.[-]<]<
Move the 100-N cell back to the correct position
[-<+>]>
Tape: 0 100-N 0' 0 0
]
And Finally!
Printing a newline
++++++++++.[-]
And decrementing the counter
<<-]
Main Questions:
• Can I make this any more optimized? My biggest concerns are:
• The number printing section, which is extremely inefficient with the modulo section
• The tape setup, which can probably be shorter.
• Should I setup the newline cell (10) in the tape generation section rather than generate it once per loop?
By just going through it in such detail in this question I've already thought of several ways to shorten the code, so there's that at least.
TAPE FORMAT:
0
5 : Buzz Counter (BC)
66 : ASCII "B"
117 : ASCII "u"
122 : ASCII "z"
105 : ASCII "i"
70 : ASCII "F"
3 : Fizz Counter (FC)
0 : FizzBuzz Check (Ch)
100 : Loop counter (C)
0
Some definitions:
' : Memory pointer is on this cell
_ : Substitute for dash
p : Substitute for plus
N : The current number
Generates the number 61:
+[-[>+<<]>-]>--
This is taken from the Esolangs brainfuck constants page at https://esolangs dot org/wiki/Brainfuck_constants
Sets all the cells to values very close to the needed ones
Basically multiplies 61 by various values (going over 255 wraps around to 0)
[>+>++>++>++++++>+>>>++++++<<<[<]>-]
Tape looks like:
0 0' 61 122 122 110 61 0 0 110
It needs to be:
0 5 66 117 122 105 70 3 0 100
Notice that (almost) all of these values are off by multiples of 5 so we increment a cell to 5
<+++++
And add/subtract 5s from each value
[>+>+>->>->++>+>>--[<<]>-]
Leaving the tape as:
0' 5 66 117 122 105 71 5 0 100
We make some final changes to get the desired cells
>[>]<--<->>>
Finally leaving the memory pointer on the counter
TAPE: 0 5 66 117 122 105 71 5 0 100'
[
CHECKING FOR FIZZBUZZ
<<- Decrement Fizz counter
[<]<[ If Fizz counter == 0
>+++ Reset counter
>+<< Increment check cell
.<.<.. Print "Fizz"
[<]<]
>>- Decrement Buzz counter
[<<]>[ If Buzz counter == 0
<+++++ Reset counter
>.>.>.. Print "Buzz"
[>>>]<<+ Increment check cell
[<]]
PRINTING NUMBER
If the number check is 0 (reset the cell if not)
>[>>>]<<[[-]>>]>
[
TAPE: BC BuziF FC 0 100_N' 0
We won't be using anything left of the 100_N so we can ignore it
Generate the number 100 and the number 10
>(10++++++++++)[->(10++++++++++)>+<<]
Tape: 0 100_N 0' 100 10
Subtract 100_N from 100 while keeping a copy of it
<[->+>-<<]
And increment N by 2 to counter some modulo stuff
>>++
Tape: 0 0 100_N Np2' 10 0
[ While N
Tape: 0 0 100_N N' Modulo Quotient 0;
>[>>>]< If the modulo is 0:
[>++++++++++>+>] Reset the modulo to 10 and increment the Quotient
<<-<- Decrement both N and the modulo
]
Tape: 0 0 100_N 0' 9_single tens
Subtract the singles cell from 10
+++++++++>[-<->]<[->+<]>>[>]
Tape: 0 0 100_N 0 single tens 0'
If the tens cell is 0:
Tape: 0 0 100_N 0 single 0'
(8++++++++)[-<(6++++++)<(6++++++)>>]
Tape: 0 0 100_N 0 single tens 0'
OR
Tape: 0 0 100_N 48 single 0'
If the tens cell was 0 reset the 48 cell
<<<[>[-]]
Tape: 0 0 100_N 0 single tens 0'
OR
Tape: 0 0 100_N 0 single 0'
Print the tens (if needed) and singles while resetting the cells
>[>]<[.[-]<]<
Move the 100_N cell back to the correct position
[-<+>]>
Tape: 0 100_N 0 0' 0
]
Print a newline
++++++++++.[-]
And decrement counter
<<-
]
• Just give me some time and I promise to review this! – Simon Forsberg Feb 1 '18 at 17:11
• @SimonForsberg No pressure, but any updates? – Jo King Apr 30 '18 at 4:23
• Still planning on reviewing it some time, unfortunately reviewing Brainfuck code is not an easy task. I'm a bit busy the coming week but I promise I haven't forgotten (entirely) about this! – Simon Forsberg May 2 '18 at 10:30 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.18653181195259094, "perplexity": 7131.8270375047905}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-18/segments/1555578841544.98/warc/CC-MAIN-20190426153423-20190426175423-00060.warc.gz"} |
https://www.r-bloggers.com/2016/01/hierarchical-clustering-in-r-2/ | Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.
Hello everyone! In this post, I will show you how to do hierarchical clustering in R. We will use the iris dataset again, like we did for K means clustering.
## What is hierarchical clustering?
If you recall from the post about k means clustering, it requires us to specify the number of clusters, and finding the optimal number of clusters can often be hard. Hierarchical clustering is an alternative approach which builds a hierarchy from the bottom-up, and doesn’t require us to specify the number of clusters beforehand.
The algorithm works as follows:
• Put each data point in its own cluster.
• Identify the closest two clusters and combine them into one cluster.
• Repeat the above step till all the data points are in a single cluster.
Once this is done, it is usually represented by a dendrogram like structure.
There are a few ways to determine how close two clusters are:
• Complete linkage clustering: Find the maximum possible distance between points belonging to two different clusters.
• Single linkage clustering: Find the minimum possible distance between points belonging to two different clusters.
• Mean linkage clustering: Find all possible pairwise distances for points belonging to two different clusters and then calculate the average.
• Centroid linkage clustering: Find the centroid of each cluster and calculate the distance between centroids of two clusters.
Complete linkage and mean linkage clustering are the ones used most often.
## Clustering
In my post on K Means Clustering, we saw that there were 3 different species of flowers.
Let us see how well the hierarchical clustering algorithm can do. We can use hclust for this. hclust requires us to provide the data in the form of a distance matrix. We can do this by using dist. By default, the complete linkage method is used.
clusters <- hclust(dist(iris[, 3:4]))
plot(clusters)
which generates the following dendrogram:
We can see from the figure that the best choices for total number of clusters are either 3 or 4:
To do this, we can cut off the tree at the desired number of clusters using cutree.
clusterCut <- cutree(clusters, 3)
Now, let us compare it with the original species.
table(clusterCut, iris$Species) clusterCut setosa versicolor virginica 1 50 0 0 2 0 21 50 3 0 29 0 It looks like the algorithm successfully classified all the flowers of species setosa into cluster 1, and virginica into cluster 2, but had trouble with versicolor. If you look at the original plot showing the different species, you can understand why: Let us see if we can better by using a different linkage method. This time, we will use the mean linkage method: clusters <- hclust(dist(iris[, 3:4]), method = 'average') plot(clusters) which gives us the following dendrogram: We can see that the two best choices for number of clusters are either 3 or 5. Let us use cutree to bring it down to 3 clusters. clusterCut <- cutree(clusters, 3) table(clusterCut, iris$Species)
clusterCut setosa versicolor virginica
1 50 0 0
2 0 45 1
3 0 5 49
We can see that this time, the algorithm did a much better job of clustering the data, only going wrong with 6 of the data points.
We can plot it as follows to compare it with the original data:
ggplot(iris, aes(Petal.Length, Petal.Width, color = iris\$Species)) +
geom_point(alpha = 0.4, size = 3.5) + geom_point(col = clusterCut) +
scale_color_manual(values = c('black', 'red', 'green'))
which gives us the following graph:
All the points where the inner color doesn’t match the outer color are the ones which were clustered incorrectly. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.48775577545166016, "perplexity": 727.5219712935004}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610703531429.49/warc/CC-MAIN-20210122210653-20210123000653-00388.warc.gz"} |
http://math.stackexchange.com/questions/82763/ax-b-problem-solving/82791 | Ax=b problem solving
Can you please tell how to solve this: Ax=b
$$A=\begin{pmatrix} 2 & 4 & -8 & 4 & 1\\ 4 & 10 &-16 & 8 &-8\\ -4 & -12 & 17 & -8 & 20\\ -2 & -10 & 10 & -3 & 34 \end{pmatrix}$$
$$b=\begin{pmatrix}-33\\-36\\4\\-62\end{pmatrix}$$
I have to give a fundamental and particular solutions.
I have tried so:
But I do not know whether it is right and what to do next ... Please, help me! Thanks.
-
I'm not sure I am familiar with your notation (is the comma representative of a decimal point?) but just based on the fact that you have 5 unknowns and 4 equations, you will either get no solutions or infinitely many solutions. As a check there is an excellent resource here (see "Solving a linear system of equations"). – process91 Nov 16 '11 at 19:27
The 2nd element of the 2nd row of the 2nd matrix should be 2 (not -6). I hope you can do it now yourself. – Tapu Nov 16 '11 at 19:31
The first thing to notice is that you have four equations in five variables -- this means you will have an infinite number of solutions or zero solutions. In the case of an infinite number, you can solve for the set of solutions in terms of one parameter.
The easiest way to do this by hand is to reduce the augmented matrix $\left( A | b\right)$ to reduced row-echelon form. This means proceed with Gaussian elimination until it reaches the form $$\left( \begin{array}{cccccc} 1 && 0 && 0 && 0 && \star && \star\\ 0 && 1 && 0 && 0 && \star && \star \\ 0 && 0 && 1 && 0 && \star && \star\\ 0 && 0 && 0 && 1 && \star && \star \end{array} \right)$$
where $\star$ is some unknown value.
For your matrix, this results in $$\left( \begin{array}{cccccc} 1 && 0 && 0 && 0 && 16.5 && -52.5\\ 0 && 1 && 0 && 0 && -5 && 15\\ 0 && 0 && 1 && 0 && 2 && -2\\ 0 && 0 && 0 && 1 && 1 && -1 \end{array} \right)$$
Thus, we see that \begin{align*} x_1 + 16.5x_5 &= -52.5 \\ x_2 - 5 x_5 &= 15 \\ x_3 + 2 x_5 &= -2 \\ x_4 + x_5 &= -1 \end{align*}
which I assume is the "general" solution. For a particular solution you can just pick any $x_5$ and solve for the remaining variables.
-
$$\left(\begin{array}{ccccc|c}2&4&-8&4&1&-33\\ 4&10&-16&8&-8&-36\\ -4&-12&17&-8&20&4\\-2&-10&10&-3&34&-62\end{array}\right)\to\left(\begin{array}{ccccc|c}2&4&-8&4&1&-33\\0&2&0&0&-10&30\\ 0&-2&1&0&12&-32\\0&-6&2&1&35&-95\end{array}\right)\to$$
$$\left(\begin{array}{ccccc|c}2&4&-8&4&1&-33\\0&1&0&0&-5&15\\ 0&0&1&0&2&-2\\0&0&2&1&5&-5\end{array}\right)\to\left(\begin{array}{ccccc|c}2&4&-8&4&1&-33\\0&1&0&0&-5&15\\ 0&0&1&0&2&-2\\0&0&0&1&1&-9\end{array}\right)\to$$
$$\left(\begin{array}{ccccc|c}2&0&0&0&33&-73\\0&1&0&0&-5&15\\ 0&0&1&0&2&-2\\0&0&0&1&1&-9\end{array}\right)$$ So your general solution is $(-\frac{73}{2},15,-2,-9,0)+x(-\frac{33}{2},5,-2,-1,1)$. Choosing a particular value of $x$ (e.g., $x=0$) you will get a particular solution.
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9993224143981934, "perplexity": 203.4404502565181}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-35/segments/1440644068098.37/warc/CC-MAIN-20150827025428-00342-ip-10-171-96-226.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/positive-gravitational-force.8708/ | # Positive Gravitational Force
1. Nov 10, 2003
### lavalamp
I know that as things "fall" towards each other, they lose potential energy, that's fine. What I want to know is when a photon falls towards a mass does the photon also lose potential energy?
I would assume so because potons have an equivalent mass. From the equation E = hf, can I therefore assume that the frequency of a photon actually lowers when it approaches the Earth?
If so then it seems to also follow that it's momentum also lowers from the equation E = pc, this then seems to suggest that photons lose mass when approaching other mass and that an impulse is applied to the photon to cause this loss of momentum.
But this would mean that the impulse was acting away from the mass, ie: the photon was experiencing a repulsive force upon approaching some matter. Is this a positive gravitational force?
Last edited: Nov 10, 2003
2. Nov 10, 2003
### pmb
Yes. That is exactly correct.
As the photons moves to a lower location the frequency as measured locally increases.
But whether the frequency or energy changes depends on who is doing the measuring. Any single observer will detect neither a change in energy nor a change in frequency as a particle moves through the g-field. Such changes are meaured locally. I.e. if an observer higher in the g-field emits a photon which then travels to an observer who is lower in the g-field. The lower observer will measure a higher frequency than the frequency which left emitter. Interpret this as a decrease in potential energy which is compensated for an increase in kinetic energy. The local observer measures zero potential energy at his location and therefore all the energy he measures is kinetic energy. For a derivation see
http://www.geocities.com/physics_world/red_shift.htm
Note: I made an error in Eq. (7) [forgot to relable the subscripts on r)
Pete
3. Nov 10, 2003
### lavalamp
So you are saying that when a photon "falls" towards a mass, it's potential energy decreases while it's kinetic energy increases? I can accept that as it is true for all other particles, however this must mean that it's mass increases upon approaching a mass. Since the photon still has the same energy, it must still have the same frequency (for an observer at the point of emission of the photon), but now I am faced with another problem.
As the equation E = mc2 shows, for any value of E there is a corresponding value for m. Since the overall energy of the photon has stayed the same, would the mass of the photon have to stay the same as well?
Another problem, photons have mass and therefore they are attracted to things like the sun and blackholes and all other particles. If there was a photon heading straight for the Earth, wouldn't it be accelerated by the Earth's gravitational field and therefore be travelling at a velocity greaty than c?
Since it is already travelling AT c, and it's mass is most definately not infinite, wouldn't the force due to the Earth's gravity cause it to accelerate? Any acceleration in the same direction as the photon is travelling would cause it to travel at a speed greater than c wouldn't it?
4. Nov 11, 2003
### pmb
Yes. And that means that the total energy remains constant.
Only when measured locally. And that, of course, is its relativistic mass that we're speaking about, not its rest mass.
Now you're talking about a different measurement. Yes. The frequency remains constant as observed by any sinlge observer.
That relationship does not hold in this case. mc2 is not the conserved quantity here. The contravariant 4-momentum of a particle is Pu = (E/c,p). In flat spacetime in an inertial frame of referance P0c = E = mc2 is a constant and is the energy of the photon. If the metric tensor is guv = diag(1,-1,-1,-1) and the covariant 4-momentum is Pu = (E/c,-p). So P0c = E too and also is a constant. However in a gravitational field P0 is not the same as P0. In a static gravitational field like the Earth's only the later is a constant.
As measured locally the speed of light is always the same constant. If not measured locally, i.e. as measured by a remote observer far from the Earth the speed of light in the Earth's gravitational field is not a constant. The force of gravity of the photon will depend on the photons's location in the gravitational field. As far as the functional relation of speed vs. position.
Yes.
That depends on where in the field it is and who is doing the measuring.
What you're failing to take into account is the fact that the acceleration of light depends on the velocity of light. E.g. at one point the speed of light starts to slow down as the light approaches a black hole.
Pete
5. Nov 11, 2003
### lavalamp
The bits that looked pretty as the flew over my head:
Is there anyway that you could dumb this down into something that I might be able to grasp a bit better?
By the way, when I say does the frequency of light change? And you say, it depends where you are observing from, I usually mean from an infinite distance away (at 0 potential energy), where you are not affected by the gravitational field.
6. Nov 12, 2003
### pmb
Let me get back to you on that. In the mean time you can read more on this in the article
"On the Interpretation of the Redshift in a Static Gravitational Field," L.B. Okun, K.G. Selivanov, V.L. Telegdi, Am.J.Phys. 68 (2000) 115
http://xxx.lanl.gov/abs/physics/9907017
Pete
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http://cstheory.stackexchange.com/users/2241/max | # Max
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