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68,430,116 | https://en.wikipedia.org/wiki/First-fit%20bin%20packing | First-fit (FF) is an online algorithm for bin packing. Its input is a list of items of different sizes. Its output is a packing - a partition of the items into bins of fixed capacity, such that the sum of sizes of items in each bin is at most the capacity. Ideally, we would like to use as few bins as possible, but minimizing the number of bins is an NP-hard problem. The first-fit algorithm uses the following heuristic:
It keeps a list of open bins, which is initially empty.
When an item arrives, find the first bin into which the item can fit, if any.
If such a bin is found, the new item is placed inside it.
Otherwise, a new bin is opened and the coming item is placed inside it.
Approximation ratio
Denote by FF(L) the number of bins used by First-Fit, and by OPT(L) the optimal number of bins possible for the list L. The analysis of FF(L) was done in several steps.
The first upper bound of for FF was proven by Ullman in 1971.
In 1972, this upper bound was improved to by Garey, Graham and Ullman, Johnson and Demers.
In 1976, it was improved by Garey, Graham, Johnson, Yao and Chi-Chih to , which is equivalent to due to the integrality of and .
The next improvement, by Xia and Tan in 2010, lowered the bound to .
Finally, in 2013, this bound was improved to by Dósa and Sgall. They also present an example input list , for which matches this bound.
Below we explain the proof idea.
Asymptotic ratio at most 2
Here is a proof that the asymptotic ratio is at most 2. If there is an FF bin with sum less than 1/2, then the size of all remaining items is more than 1/2, so the sum of all following bins is more than 1/2. Therefore, all FF bins except at most one have sum at least 1/2. All optimal bins have sum at most 1, so the sum of all sizes is at most OPT. Therefore, number of FF bins is at most 1+OPT/(1/2) = 2*OPT+1
Asymptotic ratio at most 1.75
Consider first a special case in which all item sizes are at most 1/2. If there is an FF bin with sum less than 2/3, then the size of all remaining items is more than 1/3. Since the sizes are at most 1/2, all following bins (except maybe the last one) have at least two items, and sum larger than 2/3. Therefore, all FF bins except at most one have sum at least 2/3, and the number of FF bins is at most 2+OPT/(2/3) = 3/2*OPT+1.
The "problematic" items are those with size larger than 1/2. So, to improve the analysis, let's give every item larger than 1/2 a bonus of R. Define the weight of an item as its size plus its bonus. Define the weight of a set of items as the sum of weights of its contents.
Now, the weight of each FF bin with one item (except at most one) is at least 1/2+R, and the weight of each FF bin with two or more items (except at most one) is 2/3. Taking R=1/6 yields that the weight of all FF bins is at least 2/3.
On the other hand, the weight of every bin in the optimal packing is at most 1+R = 7/6, since each such bin has at most one item larger than 1/2. Therefore, the total weight of all items is at most 7/6*OPT, and the number of FF bins is at most 2+(7/6*OPT/(2/3)) = 7/4*OPT+2.
Asymptotic ratio at most 1.7
The following proof is adapted from. Define the weight of an input item as the item size x some bonus computed as follows:
.
The asymptotic approximation ratio follows from two claims:
In the optimal packing, the weight of each bin is at most 17/12;
In the First-Fit packing, the average weight of each bin is at least 5/6 = 10/12.
Therefore, asymptotically, the number of bins in the FF packing must be at most 17/10 * OPT.
For claim 1, it is sufficient to prove that, for any set B with sum at most 1, bonus(B) is at most 5/12. Indeed:
If B has no item larger than 1/2, then it has at most five items larger than 1/6, and the bonus of each of them is at most 1/12;
If B has an item larger than 1/2 but no item in [1/3,1/2], then it has room for at most two items in (1/6,1/3), and the sum of their bonuses is at most (1/2 / 2 - 1/6) = 1/12, so the total bonus is 4/12+1/12=5/12.
If B has an item larger than 1/2 and an item in [1/3,1/2], then it has no more room for items of size larger than 1/6, so the total bonus is again 4/12+1/12 = 5/12.
Therefore, the weight of B is at most 1+5/12 = 17/12.
For claim 2, consider first an FF bin B with a single item.
If sum(B)<1/2, then - by the way FF works - all items processed after B must be larger than 1/2 (otherwise they would have been inserted into B). Therefore, there is at most one FF bin with sum<1/2.
Consider now all other bins B with a single item with sum(B)>1/2. For all these bins, weight(B)>1/2+1/3 = 5/6.
Consider now the FF bins B with two or more items.
If sum(B)<2/3, then - by the way FF works - all items processed after B must be larger than 1/3 (otherwise they would have been inserted into B). Therefore, all following bins with two or more items are larger than 2/3. So there is at most one FF bin with two or more items and sum<2/3.
Consider now all other bins with two or more items and sum>2/3. Denote them by B[1],B[2],...B[k], by the order they are opened. For each i in 1,...,k, we prove that the sum of B[i] plus the bonus of B[i+1] is at least 5/6: sum(B[i])+bonus(B[i+1]) ≥ 5/6. Indeed, if sum(B[i]) ≥ 5/6 then the inequality is trivial. Otherwise, let sum(B[i]) := 1 - x. Note that x is between 1/6 and 2/6, since sum(B[i]) is between 2/3 and 5/6. Since B[i+1] is opened after B[i], B[i+1] contains at least two items, say c1 and c2, that do not fit into B[i], that is: c1,c2 > 1-sum(B[i]) = x > 1/6. Then the bonus of each of c1 and c2 is at least x/2 - 1/12. Therefore, the bonus of B[i+1] is at least x-1/6, so sum(B[i]) + bonus(B[i+1]) ≥ (1-x)+(x-1/6) = 5/6.
We can apply the above inequality to successive pairs, and get: sum(B[1]) + bonus(B[2]) + sum(B[2]) + bonus(B[3]) + ... + sum(B[k-1]) + bonus(B[k]) ≥ 5/6*(k-1).
Therefore, the total weight of all FF bins is at least 5/6*(FF - 3) (where we subtract 3 for the single one-item bin with sum<1/2, single two-item bin with sum<2/3, and the k-1 from the two-item bins with sum ≥ 2/3).
All in all, we get that 17/12*OPT ≥ 5/6*(FF-3), so FF ≤ 17/10*OPT+3.
Dósa and Sgall present a tighter analysis that gets rid of the 3, and get that FF ≤ 17/10*OPT.
Lower bound
There are instances on which the performance bound of 1.7OPT is tight. The following example is based on. The bin capacity is 101, and:
The sequence is: 6 (x7), 10 (x7), 16 (x3), 34 (x10), 51 (x10).
The optimal packing contains 10 bins: [51+34+16] (x3), [51+34+10+6] (x7). All bin sums are 101.
The First Fit packing contains 17 bins: [6 (x7) + 10 (x5)], [10 (x2) + 16 (x3)], [34+34] (x5), [51] (x10).
The bin sums are: 92, 68, 68 (x5), 51 (x10).
The rewards (normalized to 101) are 0, 0, 16.8 (x5), 33.7 (x10).
The total weights (normalized to 101) are 92, 68, 84.8 (x5), 84.7 (x10). It can be seen that almost all weights are close to 101*5/6=84.1.
Performance with divisible item sizes
An important special case of bin-packing is that which the item sizes form a divisible sequence (also called factored). A special case of divisible item sizes occurs in memory allocation in computer systems, where the item sizes are all powers of 2. If the item sizes are divisible, and in addition, the largest item sizes divides the bin size, then FF always finds an optimal packing.
Refined first-fit
Refined-First-Fit (RFF) is another online algorithm for bin packing, that improves on the previously developed FF algorithm. It was presented by Andrew Chi-Chih Yao.
The algorithm
The items are categorized in four classes, according to their sizes (where the bin capacity is 1):
-piece - size in .
-piece - size in .
-piece - size in .
-piece - size in .
Similarly, the bins are categorized into four classes: 1, 2, 3 and 4.
Let be a fixed integer. The next item is assigned into a bin in -
Class 1, if is an -piece,
Class 2, if is an -piece,
Class 3, if is an -piece, but not the th -piece seen so far, for any integer .
Class 1, if is the th -piece seen so far,
Class 4, if is an -piece.
Once the class of the item is selected, it is placed inside bins of that class using first-fit bin packing.
Note that RFF is not an Any-Fit algorithm since it may open a new bin despite the fact that the current item fits inside an open bin (from another class).
Approximation ratio
RFF has an approximation guarantee of . There exists a family of lists with for .
See also
First-Fit-Decreasing (FFD) is the offline variant of First-Fit: it accepts all input items, orders them by descending size, and calls First-Fit. Its asymptotic approximation ratio is much better: about 1.222 instead of 1.7.
Implementations
Python: The prtpy package contains an implementation of first-fit.
References
Bin packing | First-fit bin packing | [
"Mathematics"
] | 2,630 | [
"Bin packing",
"Mathematical problems",
"Packing problems"
] |
68,430,199 | https://en.wikipedia.org/wiki/Harmonic%20bin%20packing | Harmonic bin-packing is a family of online algorithms for bin packing. The input to such an algorithm is a list of items of different sizes. The output is a packing - a partition of the items into bins of fixed capacity, such that the sum of sizes of items in each bin is at most the capacity. Ideally, we would like to use as few bins as possible, but minimizing the number of bins is an NP-hard problem.
The harmonic bin-packing algorithms rely on partitioning the items into categories based on their sizes, following a Harmonic progression. There are several variants of this idea.
Harmonic-k
The Harmonic-k algorithm partitions the interval of sizes harmonically into pieces for and such that . An item is called an -item, if .
The algorithm divides the set of empty bins into infinite classes for , one bin type for each item type. A bin of type is only used for bins to pack items of type . Each bin of type for can contain exactly -items. The algorithm now acts as follows:
If the next item is an -item for , the item is placed in the first (only open) bin that contains fewer than pieces or opens a new one if no such bin exists.
If the next item is an -item, the algorithm places it into the bins of type using Next-Fit.
This algorithm was first described by Lee and Lee. It has a time complexity of where n is the number of input items. At each step, there are at most open bins that can be potentially used to place items, i.e., it is a k-bounded space algorithm.
Lee and Lee also studied the asymptotic approximation ratio. They defined a sequence , for and proved that for it holds that . For it holds that . Additionally, they presented a family of worst-case examples for that
Refined-Harmonic (RH)
The Refined-Harmonic combines ideas from the Harmonic-k algorithm with ideas from Refined-First-Fit. It places the items larger than similar as in Refined-First-Fit, while the smaller items are placed using Harmonic-k. The intuition for this strategy is to reduce the huge waste for bins containing pieces that are just larger than .
The algorithm classifies the items with regard to the following intervals: , , , , , for , and . The algorithm places the -items as in Harmonic-k, while it follows a different strategy for the items in and . There are four possibilities to pack -items and -items into bins.
An -bin contains only one -item.
An -bin contains only one -item.
An -bin contains one -item and one -item.
An -bin contains two -items.
An -bin denotes a bin that is designated to contain a second -item. The algorithm uses the numbers N_a, N_b, N_ab, N_bb, and N_b' to count the numbers of corresponding bins in the solution. Furthermore, N_c= N_b+N_ab
Algorithm Refined-Harmonic-k for a list L = (i_1, \dots i_n):
1. N_a = N_b = N_ab = N_bb = N_b' = N_c = 0
2. If i_j is an I_k-piece
then use algorithm Harmonic-k to pack it
3. else if i_j is an I_a-item
then if N_b != 1,
then pack i_j into any J_b-bin; N_b--; N_ab++;
else place i_j in a new (empty) bin; N_a++;
4. else if i_j is an I_b-item
then if N_b' = 1
then place i_j into the I_b'-bin; N_b' = 0; N_bb++;
5. else if N_bb <= 3N_c
then place i_j in a new bin and designate it as an I_b'-bin; N_b' = 1
else if N_a != 0
then place i_j into any I_a-bin; N_a--; N_ab++;N_c++
else place i_j in a new bin; N_b++;N_c++
This algorithm was first described by Lee and Lee. They proved that for it holds that .
Other variants
Modified Harmonic (MH) has asymptotic ratio .
Modified Harmonic 2 (MH2) has asymptotic ratio .
Harmonic + 1 (H+1) has asymptotic ratio .
Harmonic ++ (H++) has asymptotic ratio and .
References
Bin packing | Harmonic bin packing | [
"Mathematics"
] | 995 | [
"Bin packing",
"Mathematical problems",
"Packing problems"
] |
68,431,669 | https://en.wikipedia.org/wiki/First-fit-decreasing%20bin%20packing | First-fit-decreasing (FFD) is an algorithm for bin packing. Its input is a list of items of different sizes. Its output is a packing - a partition of the items into bins of fixed capacity, such that the sum of sizes of items in each bin is at most the capacity. Ideally, we would like to use as few bins as possible, but minimizing the number of bins is an NP-hard problem, so we use an approximately-optimal heuristic.
Description
The FFD algorithm works as follows.
Order the items from largest to smallest.
Open a new empty bin, bin #1.
For each item from largest to smallest, find the first bin into which the item fits, if any.
If such a bin is found, put the new item in it.
Otherwise, open a new empty bin put the new item in it.
In short: FFD orders the items by descending size, and then calls first-fit bin packing.
An equivalent description of the FFD algorithm is as follows.
Order the items from largest to smallest.
While there are remaining items:
Open a new empty bin.
For each item from largest to smallest:
If it can fit into the current bin, insert it.
In the standard description, we loop over the items once, but keep many open bins. In the equivalent description, we loop over the items many times, but keep only a single open bin each time.
Performance analysis
The performance of FFD was analyzed in several steps. Below, denotes the number of bins used by FFD for input set S and bin-capacity C.
In 1973, D.S. Johnson proved in his doctoral thesis that for any instance S and capacity C.
In 1985, B.S. Backer gave a slightly simpler proof and showed that the additive constant is not more than 3.
Yue Minyi proved that in 1991 and, in 1997, improved this analysis to together with Li Rongheng.
In 2007 György Dósa proved the tight bound and presented an example for which .
Worst-case example
The lower bound example given in by Dósa is the following: Consider the two bin configurations:
;
.
If there are 4 copies of and 2 copies of in the optimal solution, FFD will compute the following bins:
4 bins with configuration ,
1 bin with configuration ,
1 bin with configuration ,
1 bin with configuration ,
1 one final bin with configuration ,
That is, 8 bins total, while the optimum has only 6 bins. Therefore, the upper bound is tight, because .
This example can be extended to all sizes of : in the optimal configuration there are 9k+6 bins: 6k+4 of type B1 and 3k+2 of type B2. But FFD needs at least 11k+8 bins, which is .
Performance with divisible item sizes
An important special case of bin-packing is that which the item sizes form a divisible sequence (also called factored). A special case of divisible item sizes occurs in memory allocation in computer systems, where the item sizes are all powers of 2. In this case, FFD always finds the optimal packing.
Monotonicity properties
Contrary to intuition, is not a monotonic function of C. Similarly, is not a monotonic function of the sizes of items in S: it is possible that an item shrinks in size, but the number of bins increases.
However, the FFD algorithm has an "asymptotic monotonicity" property, defined as follows.
For every instance S and integer m, let MinCap(S,m) be the smallest capacity C such that
For every integer m, let MinRatio(m) be the infimum of the numbers r≥1 such that, for all input sets S, . This is the amount by which we need to "inflate" the bins such that FFD attains the optimal number of bins.
Then, for every input S and for every r ≥ MinRatio(m), . This shows, in particular, that the infimum in the above definition can be replaced by minimum.
Examples
For example, suppose the input is: 44, 24, 24, 22, 21, 17, 8, 8, 6, 6. With capacity 60, FFD packs 3 bins:
44, 8, 8;
24, 24, 6, 6;
22, 21, 17.
But with capacity 61, FFD packs 4 bins:
44, 17;
24, 24, 8;
22, 21, 8, 6;
6.
This is because, with capacity 61, the 17 fits into the first bin, and thus blocks the way to the following 8, 8.
As another example, suppose the inputs are: 51, 28, 28, 28, 27, 25, 12, 12, 10, 10, 10, 10, 10, 10, 10, 10. With capacity 75, FFD packs 4 bins:
51, 12, 12
28, 28, 10
28, 27, 10, 10
25, 10, 10, 10, 10, 10
But with capacity 76, it needs 5 bins:
51, 25
28, 28, 12
28, 27, 12
10, 10, 10, 10, 10, 10, 10
10
Consider the above example with capacity 60. If the 17 becomes 16, then the resulting packing is:
44, 16;
24, 24, 8;
22, 21, 8, 6;
6.
Modified first-fit-decreasing
Modified first fit decreasing (MFFD) improves on FFD for items larger than half a bin by classifying items by size into four size classes large, medium, small, and tiny, corresponding to items with size > 1/2 bin, > 1/3 bin, > 1/6 bin, and smaller items respectively. Then it proceeds through five phases:
Allot a bin for each large item, ordered largest to smallest.
Proceed forward through the bins. On each: If the smallest remaining medium item does not fit, skip this bin. Otherwise, place the largest remaining medium item that fits.
Proceed backward through those bins that do not contain a medium item. On each: If the two smallest remaining small items do not fit, skip this bin. Otherwise, place the smallest remaining small item and the largest remaining small item that fits.
Proceed forward through all bins. If the smallest remaining item of any size class does not fit, skip this bin. Otherwise, place the largest item that fits and stay on this bin.
Use FFD to pack the remaining items into new bins.
This algorithm was first studied by Johnson and Garey in 1985, where they proved that . This bound was improved in the year 1995 by Yue and Zhang who proved that .
Other variants
Best-fit-decreasing (BFD) is very similar to FFD, except that after the list is sorted, it is processed by best-fit bin packing. Its asymptotic approximation ratio is the same as FFD - 11/9.
Implementations
Python: The prtpy package contains an implementation of first-fit decreasing.
See also
Multifit algorithm - an algorithm for identical-machines scheduling, which uses FFD as a subroutine.
References
Bin packing | First-fit-decreasing bin packing | [
"Mathematics"
] | 1,495 | [
"Bin packing",
"Mathematical problems",
"Packing problems"
] |
68,432,209 | https://en.wikipedia.org/wiki/UGC%209128 | UGC 9128 is a dwarf irregular galaxy around 6.8–7.8 Mly (2.1–2.4 Mpc) away; it is thought to be in the Local Group, although its membership is not certain. The galaxy has a mass of about , around 100 million stars, and a diameter of around 3300 ly. It is therefore quite faint, and so was only discovered in the 20th century.
UGC 9128 is around 2.7 Mly from GR 8, which is its nearest neighbour.
UGC 9128 is a starburst galaxy, with the peak of star formation being 20–100 million years ago. It is thought to have both a halo and disc.
References
Dwarf irregular galaxies
Boötes
09128
50961 | UGC 9128 | [
"Astronomy"
] | 160 | [
"Galaxy stubs",
"Astronomy stubs",
"Constellations",
"Boötes"
] |
68,432,447 | https://en.wikipedia.org/wiki/Next-fit-decreasing%20bin%20packing | Next-fit-decreasing (NFD) is an algorithm for bin packing. Its input is a list of items of different sizes. Its output is a packing - a partition of the items into bins of fixed capacity, such that the sum of sizes of items in each bin is at most the capacity. Ideally, we would like to use as few bins as possible, but minimizing the number of bins is an NP-hard problem. The NFD algorithm uses the following heuristic:
Order the items from largest to smallest.
Initialize an empty bin and call it the "open bin".
For each item in order, check if it can fit into the open bin:
If it fits, then place the new item into it.
Otherwise, close the current bin, open a new bin, and put the current item inside it.
In short: NFD orders the items by descending size, and then calls next-fit bin packing.
Performance upper bound
Baker and Coffman proved that, for every integer r, when the size of all items is at most 1/r, the asymptotic approximation ratio of RFD satisfies,where is a sequence whose first elements are approximately 1.69103, 1.42312, 1.30238. In particular, taking r=1 implies that .
Later, NFD has also been analyzed probabilistically.
Variants
Next-Fit packs a list and its inverse into the same number of bins. Therefore, Next-Fit-Increasing has the same performance as Next-Fit-Decreasing.
However, Next-Fit-Increasing performs better when there are general cost structures.
References
Bin packing | Next-fit-decreasing bin packing | [
"Mathematics"
] | 347 | [
"Bin packing",
"Mathematical problems",
"Packing problems"
] |
68,433,977 | https://en.wikipedia.org/wiki/V723%20Monocerotis | V723 Monocerotis is a variable star in the constellation Monoceros. It was proposed in 2021 to be a binary system including a lower mass gap black hole candidate nicknamed "The Unicorn". Located 1,500 light years from Earth, it would be the closest black hole to our planet, and among the smallest ever found.
Located in the Monoceros constellation, V723 Monocerotis is an eighth-magnitude ellipsoidal variable yellow giant star roughly the mass of the Sun, but 25 times its radius. The accompanying black hole was proposed to have a mass 3 times the mass of the Sun, corresponding to a Schwarzschild radius of 9 kilometers.
Follow-up work in 2022 argued that V723 Monocerotis does not contain a black hole, but is a mass-transfer binary containing a red giant and a subgiant star that has been stripped of much of its mass.
See also
Stellar black hole
List of nearest known black holes
References
Further reading
Monoceros
G-type bright giants
Binary stars
Monocerotis, V723
030891
045762 | V723 Monocerotis | [
"Astronomy"
] | 233 | [
"Monoceros",
"Constellations"
] |
68,435,028 | https://en.wikipedia.org/wiki/Architextiles | Architextiles refers to a broad range of projects and approaches that combine architecture, textiles, and materials science. Architextiles explore textile-based approaches and inspirations for creating structures, spaces, surfaces, and textures. Architextiles contribute to the creation of adaptable, interactive, and process-oriented spaces. Awning is the most basic type of architectural textile. In Roman times, a velarium was used as an awning to cover the entire cavea, the seating area within amphitheaters, serving as a protection for the spectators against the sun.
Hylozoic Ground, on the other hand, is a modern and complex architextile example. Hylozoic Ground is an interactive architecture model presented in the 18th Biennale of Sydney. Olympiastadion is another example of modern architecture presented in an unusual way.
Etymology
Architextiles is a portmanteau word of textiles and architecture. 'Technology' and 'Textiles' both are derivation of a Latin language word that means 'construct' or 'weave'.Textiles is also among derivative words of the Ancestor of the Indo-European language word "tek" which is the root to architecture.
Architecture and textiles
Architectural textiles
Architextiles is the architecture that is inspired by characteristics, elements, and manufacturing techniques of textiles. It is a field that spans multiple disciplines. It is a combination of textile and architectural manufacturing techniques. Laser cutting, ultrasonic welding, thermoplastic setting, pultrusion, electrospinning, and other advanced textile manufacturing techniques are all included in architextiles. Architextiles integrate various fields like architecture, textile design, engineering, physics and materials science.
Textile inspirations
Architextiles exploits the sculptural potential of textile-based structures. Textiles motivate architects with their numerous features, enabling them to express ideas via design and create environmentally conscious buildings. Textiles also influence architecture in the following ways:
Characteristics
Textiles are adaptable, lightweight, and useful for a variety of structures, both temporary and permanent. Tensile surfaces composed of structural fabrics, such as canopies, roofs, and other types of shelter, are included in architectural textiles. If necessary, the subjected materials are given special purpose finishes, such as waterproofing, to make them suitable for outdoor use.
Coated fabrics
There is considerable use of coated materials in certain architectures, Pneumatic structures are made of teflon or PVC-coated synthetic materials. Coated fiberglass, coated polyethylene and coated polyester are the most common materials used in lightweight structural textiles. Lightweight fabric constructions accounted for 13.2 square yards of total usage in 2006, according to Industrial Fabrics Association International (IFAI) Chemically inert, Polytetrafluoroethylene fibreglass coating is capable of withstanding temperatures as low as -100 °F (-73 °C) and as high as +450 °F (232 °C).
Interactive textiles
Textiles that can sense stimuli are known as interactive textiles. They have the capability to adapt or react to the environment. Felecia Davis has designed interactive textiles such as parametric tents that are able to change size and shape in response to changes in light and the number of people underneath.
3D structures
Soundproof 3D woven walls with a ribbed structure that are suitable for soundproofing and interior designing. Aleksandra Gaca designed the furnishing of the concept car Renault Symbioz with a 3D fabric named 'boko'.
Origami-inspired textiles
Textiles inspired by origami impart novel properties to architecture. Architects try out origami and three-dimensional fabric structures when designing structures.
History
Examples of architextiles have been found dating back a long way. Over centuries, nomadic tribes in the Middle East, Africa, the Orient, and the Americas have developed textile structures.
Historical structures
Historical architextiles include yurts and tents, the great awnings of Colosseum in Rome, the tents of the Mongol Empire, and the Ziggurat Aquar Quf near Baghdad.
Present
Properties
Architextiles have a number of advantages; primarily, they are cost effective and can be used to construct temporary or transportable structures. The programming can be modified at any time.
Examples of architextiles
Muscle NSA
NSA Muscle, is a pressurized (Inflatable body) structure which is an interactive model. It is equipped with sensors and computing systems, the MUSCLE is programmed to respond to human visitors.
Carbon tower
The carbon tower is a prototype carbon fiber building.
Hylozoic Ground
Hylozoic Ground is an exemplar of live architecture, interactive model of architecture which is a kind of architextiles.
Textile growth monument
Textile growth monument ‘textielgroeimonument’ is a 3D 'woven' structure in the city Tilburg.
Pneumatrix
Pneumatrix, RCA Department of Architecture, London, a theatre which is deployable and flexible.
See also
3D textiles
Maison folie de Wazemmes
Lars Spuybroek
Tent
Wearable technology
References
Textiles
Architecture
Buildings and structures by type | Architextiles | [
"Engineering"
] | 1,059 | [
"Construction",
"Buildings and structures by type",
"Architecture"
] |
68,435,956 | https://en.wikipedia.org/wiki/Neptunium%20diarsenide | Neptunium diarsenide is a binary inorganic compound of neptunium and arsenic with the chemical formula . The compound forms crystals.
Synthesis
Heating stoichiometric amounts of neptunium hydride and arsenic:
Physical properties
Neptunium diarsenide forms crystals of the tetragonal system, space group P4/nmm, cell parameters a = 0.3958 nm, c = 0.8098 nm.
References
Neptunium(III) compounds
Arsenides
Inorganic compounds | Neptunium diarsenide | [
"Chemistry"
] | 110 | [
"Inorganic compounds"
] |
68,436,286 | https://en.wikipedia.org/wiki/Triazolium%20salt | Triazolium salts are chemical compounds based on the substituted triazole structural element. They are composed of a cation based on a heterocyclic five-membered ring with three nitrogen atoms, two of which are functionalized and a corresponding counterion (anion). Depending on the arrangement of the three nitrogen atoms the triazolium salts are divided into two isomers, namely 1,3,4-trisubstituted-1,2,3-triazolium salts as well as 1,2,4-triazolium salts. They are precursors for the preparation of N-heterocylcic carbenes.
1,3,4-trisubstituted-1,2,3-triazolium salts
1,3,4-trisubstituted-1,2,3-triaolium salts can be synthesized from 3,4-disubsituted-1,2,4-triazol molecule by quaternization of the 1 nitrogen. This quaternization can be done by reaction with alkyl iodides (or other alkyl halide, albeit less yield is generally observed due to less reactivity, alkyl fluoride are rarely seen as they are mostly unreactive) yielding the corresponding 1,3,4-trisubstituted 1,2,3-triazolium salt with iodine. Similarly 1,3,5-trisubstituted-1,2,3-triazolium salts can be obtained from 3,5-disubsituted-1,2,4-triazol.
1,4-disubstituted 1,2,4-triazolium salts
1,4-disubstituted 1,2,4-triaolium salts can be synthesized from 4-subsituted 1,2,4-triazol molecule by quaternization of the 1 nitrogen. This quaternization can be done by reaction with alkyl iodides (or other alkyl halide, albeit less yield is generally observed due to less reactivity, alkyl fluoride are rarely seen as they are mostly unreactive) yielding the corresponding 1,4-disubstituted 1,2,4-triazolium salt with iodine.
References
Triazoles
Heterocyclic compounds
Quaternary ammonium compounds | Triazolium salt | [
"Chemistry"
] | 510 | [
"Organic compounds",
"Heterocyclic compounds"
] |
68,436,355 | https://en.wikipedia.org/wiki/Limiting%20amplitude%20principle | In mathematics, the limiting amplitude principle is a concept from operator theory and scattering theory used for choosing a particular solution to the Helmholtz equation. The choice is made by considering a particular time-dependent problem of the forced oscillations due to the action of a periodic force.
The principle was introduced by Andrey Nikolayevich Tikhonov and Alexander Andreevich Samarskii.
It is closely related to the limiting absorption principle (1905) and the Sommerfeld radiation condition (1912).
The terminology -- both the limiting absorption principle and the limiting amplitude principle -- was introduced by Aleksei Sveshnikov.
Formulation
To find which solution to the Helmholz equation with nonzero right-hand side
with some fixed , corresponds to the outgoing waves,
one considers the wave equation with the source term,
with zero initial data . A particular solution to the Helmholtz equation corresponding to outgoing waves is obtained as the limit
for large times.
See also
Limiting absorption principle
Sommerfeld radiation condition
References
Linear operators
Operator theory
Scattering theory
Spectral theory | Limiting amplitude principle | [
"Chemistry",
"Mathematics"
] | 213 | [
"Functions and mappings",
"Scattering theory",
"Mathematical analysis",
"Mathematical analysis stubs",
"Scattering stubs",
"Mathematical objects",
"Linear operators",
"Scattering",
"Mathematical relations"
] |
69,718,146 | https://en.wikipedia.org/wiki/Berkelium%28III%29%20nitrate | Berkelium(III) nitrate is the berkelium salt of nitric acid with the formula Bk(NO3)3. It commonly forms the tetrahydrate, Bk(NO3)3·4H2O, which is a light green solid. If heated to 450 °C, it decomposes to berkelium(IV) oxide and 22 milligrams of the solution of this compound is reported to cost one million dollars.
Production and uses
Berkelium(III) nitrate is produced by the reaction of berkelium metal, the hydroxide, or chloride with nitric acid. This compound has no commercial uses, but was used to synthesize the element tennessine. The aqueous compound was painted onto a titanium foil and was bombarded with calcium-48 atoms to synthesize the element tennessine.
This compound is used as a pathway to pentavalent berkelium compounds by the collision-induced dissociation of this compound to produce BkO2(NO3)2– which contains berkelium in the +5 oxidation state.
References
Berkelium compounds
nitrates | Berkelium(III) nitrate | [
"Chemistry"
] | 234 | [
"Nitrates",
"Oxidizing agents",
"Salts"
] |
69,720,399 | https://en.wikipedia.org/wiki/Rig%20category | In category theory, a rig category (also known as bimonoidal category or 2-rig) is a category equipped with two monoidal structures, one distributing over the other.
Definition
A rig category is given by a category equipped with:
a symmetric monoidal structure
a monoidal structure
distributing natural isomorphisms: and
annihilating (or absorbing) natural isomorphisms: and
Those structures are required to satisfy a number of coherence conditions.
Examples
Set, the category of sets with the disjoint union as and the cartesian product as . Such categories where the multiplicative monoidal structure is the categorical product and the additive monoidal structure is the coproduct are called distributive categories.
Vect, the category of vector spaces over a field, with the direct sum as and the tensor product as .
Strictification
Requiring all isomorphisms involved in the definition of a rig category to be strict does not give a useful definition, as it implies an equality which signals a degenerate structure. However it is possible to turn most of the isomorphisms involved into equalities.
A rig category is semi-strict if the two monoidal structures involved are strict, both of its annihilators are equalities and one of its distributors is an equality. Any rig category is equivalent to a semi-strict one.
References
Monoidal categories | Rig category | [
"Mathematics"
] | 283 | [
"Monoidal categories",
"Mathematical structures",
"Category theory"
] |
69,720,530 | https://en.wikipedia.org/wiki/Dual%20input | Dual input or dual point user input are common terms describing the 'multiple touch input on two devices simultaneously' challenge.
When there are touch input commands from two touch monitors simultaneously this will require a technical solution to function. This is because some operating systems only allow one cursor to work. When there are two users, like in the picture example, the two simultaneous dual input actions would require two “cursors” in the operating system to function. If one of the users also has a mouse connected to their display there is a risk that the second user would interrupt the first user by moving the mouse cursor. In this example the second display user would normally interfere with the main screen user.
These technical solutions can for example be observed in patent applications in the dual input field.
End consumers sometimes need help and assistance to get this setup working with two touch monitors.
There are dedicated companies working with dual input solutions to other enterprise companies for example ID24 second displays. Another B2B example which required a technical solution was two 55" LCD TV's each with their own IR touch overlay. This required additional help to solve the dual input on two screens simultaneously.
Finally we also see web technology frameworks adding dual input support. One example is Smart client which released support for dual input in their software v. 12.
See also
Multi-monitor
Touchscreen
References
Multi-monitor
Electronic display devices
Display technology | Dual input | [
"Engineering"
] | 285 | [
"Electronic engineering",
"Display technology"
] |
69,722,529 | https://en.wikipedia.org/wiki/Hornet%20%28app%29 | Hornet is a location-based social networking and online dating application for gay, bisexual, and non-heterosexual men, as well as other men who have sex with men (MSM). In 2018, it was seen as "Grindr's chief competitor in the gay app market". As well as featuring other men, the app contains city guide books and LGBT-specific news.
The app is intended to be used in countries where coming out as LGBT is problematic (see LGBT rights by country or territory), but can be used in most countries in the world. Many users of Hornet also use another similar MSM apps, with Grindr, Scruff and Jack'd being the most popular in the United States.
References
External links
LGBTQ social networking services
LGBTQ online dating services
Geosocial networking
Social networking services
Mobile social software
Online dating services
Online dating services of the United States
Online dating applications
iOS software
Android (operating system) software
BlackBerry software | Hornet (app) | [
"Technology"
] | 194 | [
"Mobile software stubs",
"Mobile technology stubs"
] |
69,722,725 | https://en.wikipedia.org/wiki/Miriam%20Violet%20Griffith | Miriam Violet Griffith (11 October 1911 – 9 May 1989) was an electrical engineer, technical author and an early user of ground source heat pumps. She was an expert in the area of heat pumps and was elected a fellow of the Institute of Physics.
Early life
Miriam Violet Griffith was born on 11 October 1911 in Carlisle, England, eldest daughter of Sarah (née Pearce) and Rev. Leopold David Griffith. By 1921 she lived at The Rectory, Silvington, Cleobury Mortimer, Shropshire with her parents, two sisters, one brother and a 15-year-old servant.
Education
She attended Casterton School in Carnforth from 1921 - 1927 and then Cheltenham Ladies College for her final years of secondary education. Griffith obtained a degree in Physics from Bedford College, University of London. She was made a Fellow of the institute of Physics prior to 1949.
Career
In 1935 Griffith was working at the British Electrical and Allied Industries Research Association Laboratories as a junior technical assistant and a colleague of Winifred Hackett. The same year she joined the Women's Engineering Society.
In 1948 she undertook research in heat pumps particularly ground-source heat pumps, considering impacts of a lower soil temperature on a kitchen garden. Robert C. Webber is credited as developing and building the first ground heat pump in the same year.
Griffith is recognised as being one of the first researchers in the field of ground-source heat pumps and coined the terminology Performance Energy Ratio (PER) to describe the system performance of a heat pump. When presenting her research in 1957 she proposed that PER was adopted as a common standard but there was some disagreement as an audience member commented that engineers are used "to thinking in terms of coefficient of performance" and as such the term did not persist.
Miriam Violet Griffith died on 9 May 1989.
Bibliography
Pre-Arcing Phenomena in Fuse Wires with Direct Current; Authors: H W Baxter; Miriam Violet Griffith; British Electrical and Allied Industries Research Association. Technical Report. Reference G/T 152, London, 1944.
Voltage Distribution in Station Equipment subjected to High D.C. Test Voltages, Miriam Violet Griffith, British Electrical and Allied Industries Research Association. London, 1944.
The Transient Warming of Rooms. Author: Miriam Violet Griffith, British Electrical and Allied Industries Research Association. Technical Report. Reference Y/T5. London, 1946.
The Thermal Characteristics of a Concrete Floor Heated by Buried Cables. Miriam Violet Griffith, British Electrical and Allied Industries Research Association. Technical Report. London, 1947.
The Effect of Cold Inflow Rate, Orifice Design and Storage Water Temperature on Stratification in Domestic Hot Water Storage Vessels. [With diagrams.] by Miriam Violet Griffith, British Electrical and Allied Industries Research Association. London 1947.
The Calculation of Steady State Heat Flow through the Walls of Thermally-Insulated Bodies, with special reference to hot water storage vessels by Miriam Violet Griffith, British Electrical and Allied Industries Research Association. London 1947.
The effect of surface material, surface finish, temperature of operation and water composition on the deposition of carbonate scale on electric immersion heaters of high specific loading. Authors; Miriam Violet Griffith; Honor Mary Browning, British Electrical & Allied Industries Research Association, 1951.
The effect on electricity consumption of the layout of coal-electric water-heating systems. Miriam Violet Griffith, British Electrical & Allied Industries Research Association, 1951. Characteristics of a small heat pump installation. Authors: Miriam Violet Griffith; H J Eighteen, British Electrical and Allied Industries Research Association, 1952.
The Shinfield heat pump. Interim report. Authors: Miriam Violet Griffith; H J Eighteen, British Electrical & Allied Industries Research Association, Technical reports series; Y/T20, 1952.
Heat pump sources, and Heat transfer from soil to buried pipes. Miriam Violet Griffith, British Electrical & Allied Industries Research Association, 1952.
Heat pump operation in Great Britain, Miriam Violet Griffith, British Electrical & Allied Industries Research Association, 1958.
The Effect of Suspended Floor Structure on Off-Peak Floor Warming Performance. An electrical analogue study. [With plates.] Authors: B.G. Tunmore, and Miriam Violet Griffith, Publisher: British Electrical and Allied Industries Research Association, Leatherhead, 1962.
The effect of carpets on the performance of floor warming systems, Miriam Violet Griffith, Leatherhead, Surrey, Electrical Research Association, 1965. ERA report, no. 5108.
References
1911 births
1989 deaths
Women engineers
Electrical engineers
British electrical engineers
Women's Engineering Society
Alumni of Bedford College, London
People educated at Cheltenham Ladies' College | Miriam Violet Griffith | [
"Engineering"
] | 903 | [
"Electrical engineering",
"Electrical engineers"
] |
69,723,841 | https://en.wikipedia.org/wiki/Weather%20of%202017 | The following is a list of weather events that occurred in 2017.
Summary by weather type
Winter storms and cold waves
Winter weather in 2017 kicked off with a winter storm from January 4-8. This winter storm causes six fatalities. Around a week later, an ice storm causes 9 fatalities. Portland, Oregon saw the most snow in a single day in 20 years. Around a week after that, a nor'easter from the Tornado outbreak of January 21-23, 2017 caused a death in Philadelphia, It also resulted in 100 accidents in Quebec. After a lull in activity, winter weather resumed on February 9, which caused a man to die in Manhattan. New York City had record warmth the day before. Then, another winter storm rode up the East Coast a few days later, killing two. Six thousand power outages occur in Nova Scotia. A month later, a giant blizzard rode up the East Coast. At least 16 people were killed. A record no-snow streak in Chicago was ended. Another winter storm affected the Rocky Mountains in late April. Pueblo, Colorado saw 9200 power outages as a result, and portions of Interstate 70 in Kansas shut down. While mostly rain, a significant storm complex affected the Northeastern United States in late October. It caused over $100 million in damage, and 1.3 million power outages. Maine set a record number of power outages. However, the mountains of West Virginia record up to of snow. In early December, a winter storm results in 3 deaths and 400,000 power outages. The year ends with a record breaking cold wave. Flint, Michigan set a monthly record low.
Floods
Droughts, heat waves, and wildfires
Tornadoes
The year started with an intense tornado outbreak that became the 2nd largest and 2nd deadliest for January. The 81 tornadoes resulted in 20 deaths. An EF3 tornado in Mississippi caused 4 deaths, 57 injuries and $9.46 million in damage. The next day, an EF3 tornado in Georgia causes 11 deaths, 45 injuries and $2.5 million in damage. Another EF3 tornado in Georgia caused 5 deaths, 40 injuries and $310 million in damage. Total damage was $1.3 bilion in damages. Two weeks later, an EF3 tornado strikes New Orleans, causing 33 injuries, including 5-6 serious. It caused at least $2.7 million in damage. It was part of a small outbreak of 15 tornadoes that day. Total economic losses were estimated at $175 million. Another intense outbreak occurs in late February and early March. This included an EF4 tornado in Missouri and Illinois, causing 1 death, 12 injuries and $14.8 million in damage. Another EF3 in Illinois and Indiana causes 1 death, 2 injuries and $5.7 million in damage. As another tornado that day killed two in Illinois, the total death toll was four. Total damage is $1.3 billion. A week later, another tornado outbreak affected the Central United States. Nineteen people were injured, Damage totaled $2.5 billion. More tornadoes affect the US on April 2 and 3. The 59 tornadoes from the system cause 3 deaths. Less than a week later, two die due to a tornado in Paraguay. Another tornado outbreak affected the United States in late April and early May. The storm system resulted in $1.9 billion, and caused 20 total deaths. Five of those deaths are tornadic. Two fatal tornadoes strike Canton, Texas which cause a combined 4 fatalities, 49 injuries and $1.87 million. A tornado outbreak sequence in mid to late May results in 2 deaths, 39 injuries and $975 million. Significant tornadic activity slowed down after this. On August 6, a small outbreak of tornadoes occurred near Tulsa, Oklahoma. The tornadoes cause 30 injuries, all due to an EF2 in Tulsa, and $50.24 million, of which $50 million is due to the EF2 in Tulsa. Five days later, more tornadoes occur in China. The tornadoes cause 5 deaths and 58 injuries.
Tropical cyclones
The first tropical cyclone of the year was a tropical disturbance in the South Pacific, which formed on January 2 over the Solomon Islands. It was the first of 20 tropical cyclones in the South Pacific during the year, including Cyclone Donna, which became the strongest cyclone on record in the basin in the month of May, with 10 minute sustained winds of 205 km/h (125 mph). In the neighboring Australian basin, there were 28 tropical cyclones, most of them weak; however, Cyclone Ernie in April reached Category 5 intensity on the Australian tropical cyclone intensity scale, with 10 minute sustained winds of 220 km/h (140 mph). Cyclone Debbie struck Queensland in March, causing A$3.5 billion (US$2.67 billion) in damage and 14 deaths across Australia. In November, Cyclone Cempaka killed 41 people in Indonesia from heavy rainfall. The south-west Indian Ocean was quiet, with only six tropical cyclones during the year. Of these, Cyclone Dineo in February killed at least 258 people when it moved through Mozambique and Zimbabwe. Cyclone Enawo struck Madagascar in March, killing 78 people. There was also a subtropical cyclone – Guará – which formed off Brazil in December.
In the northern hemisphere, activity began on January 7, when a tropical depression formed and later moved across the Philippines, killing 11 people. It was the first of 41 tropical cyclones in the western Pacific Ocean in the year. The final two storms of the season – Kai-tak and Tembin – moved through the Philippines in December, together causing 406 deaths. The year's costliest typhoon was Hato, which left more than US$4.34 billion in damage when it moved ashore southern China near Hong Kong. In the north Indian Ocean, there were 10 tropical cyclones, which included several deadly storms. Cyclone Ockhi in December killed more than 137 people in Sri Lanka and southern India. There were 20 tropical cyclones in the eastern Pacific Ocean, including Tropical Storm Lidia, which killed 20 people when it struck western Mexico.
In the Atlantic Ocean, activity began in April and lasted until November, with 18 tropical cyclones, including several deadly and costly storms. In August, Hurricane Harvey struck southeastern Texas and subsequently stalled over the state, dropping 60.58 in (1,539 mm) of rainfall; this was the highest amount of precipitation associated with a tropical cyclone in the United States. The rains caused widespread flooding along the storm's path, particularly near Houston, resulting in more than 100 fatalities and US$125 billion in damage, tying Harvey with Hurricane Katrina in 2005 as the costliest United States hurricane. In September, Hurricane Irma struck the northern Lesser Antilles and later Cuba as a Category 5 hurricane, and later Florida at a lower intensity, causing more than US$50 billion in damage and 139 deaths. Two weeks after Irma, Hurricane Maria struck Dominica as a Category 5 hurricane and later Puerto Rico as a Category 4 hurricane, causing US$90 billion in damage and more than 3,000 deaths, mostly in Puerto Rico. Also during the season, Hurricane Nate produced damaging floods across Central America, killing 45 people.
In addition to the above cyclones, there was a Mediterranean tropical-like cyclone called Cyclone Numa, which killed 22 people when it struck Greece.
Timeline
This is a timeline of weather events during 2017. Please note that entries might cross between months, however, all entries are listed by the month they started.
January
January 2 – A tornado outbreak, across the Gulf Coast of the United States, killed four people (non-tornadic) and caused over $250 million (2017 USD) in damage from 36 tornadoes.
January 10–17 – An ice storm and tornado outbreak across North America killed nine people, injured two others (tornadic), and caused multiple states to declare a state of emergency. The storm produced 11 tornadoes in Texas.
January 21–24 – A tornado outbreak, windstorm, and nor'easter, across the Southeastern and Northeastern United States and Quebec, killed 22 people (20 tornadic and 2 non-tornadic), injured 204 others, and caused $1.3 billion (2017 USD) in damage from 81 tornadoes, becoming the second-largest January tornado outbreak and the third-largest winter tornado outbreak since 1950 as well as the largest outbreak on record in Georgia. The outbreak was also the second-deadliest outbreak in January since 1950.
January 21 – An EF3 tornado in Mississippi killed four people, injured 57 others, and caused $9 million (2017 USD) in damage, while tearing through William Carey University and Hattiesburg, Mississippi on its 31.3 mi (50.4 km) path.
January 22 – An EF3 tornado in Georgia killed 11 people and injured 45 others, while passing south of Adel, Georgia, along a 24.88 mi (40.04 km) path.
January 22 – An EF3 rain-wrapped wedge (2,200 yards wide) tornado in Georgia killed five people, injured 40 others, and caused $300 million (2017 USD) in damage along its 70.69 mi (113.76 km) path. The National Weather Service issued tornado emergency when it passed through Albany, Georgia.
February
February 7 – A tornado outbreak, across the Southeastern United States, killed one person, injured 40 others, and caused over $175 million (2017 USD) in damage from 15 tornadoes.
February 7 – An EF3 tornado in New Orleans, Louisiana injured 33 people and caused $2.7 million (2017 USD) in damage along its 10.09 mi (16.24 km) path.
February 23-24 - Record heat surges into the Northeastern United States. On February 24, New York City sees a February record warm low of . Boston saw a record monthly high of . Albany, which hit , saw its warmest temperature in meteorological winter on record. The day before, Syracuse tied a monthly record high, at .
February 25 – Five tornadoes touch down in Pennsylvania, Maryland, and Massachusetts, including an EF1, which became the first Massachusetts tornado on record during the month of February.
February 28–March 1 – A tornado outbreak, across the Central United States, Ohio Valley, Eastern United States and Southern United States, killed four people, injured 68 people (38 tornadic and 30 non-tornadic), and caused $1.3 billion (2017 USD) in damage.
March
March 6–7 – A tornado outbreak across the Central United States injured 19 people from 63 tornadoes.
March 9–18 – A blizzard across North America, unofficially named Winter Storm Stella, Blizzard Eugene, and Blizzard of 2017, killed 16-19 people and caused over 100,000 power outages. The storm system also spawned three tornadoes in Florida and wind gusts of were reported on Mount Washington, New Hampshire.
April
May
May 15-20 - A tornado outbreak sequence killed 2 people and injured 38 more from 134 tornadoes.
May 19 - Both LaGuardia Airport and Burlington, Vermont tie record high temperatures for the month of May, at and respectively.
June
July
July 15 – Flash floods near Payson, Arizona killed ten people and injured four others.
August
August 6 – Four tornadoes around Tulsa, Oklahoma injured 30 people and caused $50.24 million (2017 USD) in damage.
August 17 – September 2 – Hurricane Harvey kills 103 people due to extreme flooding in Texas. It also kills one in Guyana, two in Arkansas, one in Tennessee and one in Kentucky. Overall it causes 108 deaths and $125 billion in damages, tying it with Hurricane Katrina as the costliest hurricane.
August 30 - September 12 - Hurricane Irma strikes the Caribbean Sea and Southeastern United States, causing 134 deaths and over $77.8 billion.
September
September 16-30 - Hurricane Maria makes landfall in the Windward Islands and Puerto Rico, killing 3,059 and causing $91.6 billion in damages.
September 25-27 - Syracuse, New York experienced its latest in-year heat wave, with temperatures hitting on September 25 and 27 and on September 26.
October
October 28-29 - Tropical Storm Philippe caused 5 deaths and $100 million in damage across Central America and Florida.
October 28-31 - A storm complex causes $100 million and 1.3 million power outages.
November
December
December 23, 2017 – January 19, 2018 – A cold wave caused damaging low temperatures across eastern North America. The cold wave also caused Tallahassee, Florida to receive trace amounts of frozen precipitation for the first time in more than 30 years.
References
Weather by year
2017 meteorology | Weather of 2017 | [
"Physics"
] | 2,566 | [
"Weather",
"Physical phenomena",
"Weather by year"
] |
69,726,571 | https://en.wikipedia.org/wiki/%28Trimethylsilyl%29methyllithium | (Trimethylsilyl)methyllithium is classified both as an organolithium compound and an organosilicon compound. It has the empirical formula LiCH2Si(CH3)3, often abbreviated LiCH2TMS. It crystallizes as the hexagonal prismatic hexamer [LiCH2TMS]6, akin to some polymorphs of methyllithium. Many adducts have been characterized including the diethyl ether complexed cubane [Li4(μ3-CH2TMS)4(Et2O)2] and [Li2(μ-CH2TMS)2(TMEDA)2].
Preparation
(Trimethylsilyl)methyllithium, which is commercially available as a THF solution, is usually prepared by treatment of (trimethylsilyl)methyl chloride with butyllithium:
(CH3)3SiCH2Cl + BuLi → (CH3)3SiCH2Li + BuCl
(Trimethylsilyl)methylmagnesium chloride is often functionally equivalent to (trimethylsilyl)methyllithium. It is prepared by the Grignard reaction of (trimethylsilyl)methyl chloride.
Use in methylenations
In one example of the Peterson olefination, (trimethylsilyl)methyllithium reacts with aldehydes and ketones to give the terminal alkene (R1 = Me, R2 & R3 = H):
Metal derivatives
(Trimethylsilyl)methyllithium is widely used in organotransition metal chemistry to affix (trimethylsilyl)methyl ligands. Such complexes are usually produced by salt metathesis involving metal chlorides. These compounds are often highly soluble in nonpolar organic solvents, enjoying stability due to their steric bulk and resistance to beta-hydride elimination. In these regards, (trimethylsilyl)methyl is akin to neopentyl.
Bis(trimethylsilyl)methylmagnesium is used as an alternative to (trimethylsilyl)methyllithium.
Related compounds
bis(trimethylsilyl)methyllithium
tris(trimethylsilyl)methyllithium
References
Organolithium compounds
Trimethylsilyl compounds | (Trimethylsilyl)methyllithium | [
"Chemistry"
] | 500 | [
"Organolithium compounds",
"Functional groups",
"Trimethylsilyl compounds",
"Reagents for organic chemistry"
] |
69,726,724 | https://en.wikipedia.org/wiki/Gold%20in%20early%20Philippine%20history | The extensive use of gold during early Philippine history is well-documented, both in the archeological record and in the various written accounts from precolonial and early Spanish colonial times. Gold was used throughout the Philippine archipelago in various decorative and ceremonial items, as clothing, and also as currency.
Gold was readily available throughout the Philippine archipelago, and gold items were valued as symbols of power and markers of elite status, although studies of grave artifacts suggest that these items were not as valued in precolonial Philippines as traded ornaments were. Gold was plentiful enough that local elites did not feel the need to acquire large amounts of it, and only sought it as the need arose, by trading with settlements which produced it through low intensity mining.
Among the most prominent sites for gold mining in early Philippine history were Aringay-Tonglo-Balatok trade route covering the Cordillera Mountain Range and the Lingayen gulf towns of Agoo and Aringay; the mines of Paracale on the Bicol Peninsula which were a major source of gold for the trading centers of the Visayan islands, particularly Panay and Cebu; and the Butuan-Surigao area, particularly along the Agusan river on the island of Mindanao, which made Butuan (historical polity) an important trading center.
Sources and documentation
Scholarly information about the use of gold in early Philippine history comes mostly from artifacts that have been discovered in various sites in the Philippines, and from historical accounts from the early Spanish colonial period. Archeological excavation sites include ones in Batangas, Mindoro, Luzon, Samar, Butuan and Surigao.
Prominent gold mining sites
Gold mined from the Cordillera Mountain Range were brought down to the coast through the Aringay-Tonglo-Balatok gold trail, making commercial trade centers out of Aringay and the neighboring settlement of Agoo, whose coast at the time was shaped in such a way that it was a good harbor for foreign vessels coming into Lingayen Gulf. On the island of Mindanao, gold was mined along the Agusan River in the Butuan-Surigao area and extensively worked in the Butuan polity located at the mouth of the Agusan River.
Significant discoveries
Many discoveries of precolonial gold artifacts go unreported because the gold is found or stolen by treasure hunters, who simply melt the gold down for profit. Among the most important gold artifact discoveries are the "Surigao Treasure" found by construction worker Berto Morales in 1991, the Agusan image found by Manobo woman Belay Campos in 1917, the Bolinao Skull discovered by the National Museum of the Philippines at the Balingasay Archaeological Site in Bolinao, Pangasinan,and the Oton Death Mask excavated rom San Antonio, Iloilo on Panay Island by a team from the National Museum of the Philippines and the University of the Philippines Diliman in the 1960s.
Uses of Gold
Jewelry and Clothing
Upon first arriving in the Philippine archipelago, landing specifically in the visayas, Spanish colonizers noted astonishing amounts of gold in common use, including earrings, armbands legbands, gold chains, collars of beads, wristlets, armlets, finger rings, and so on. They were also integrated into clothing as sequins, as clasps or buttons for cloaks or as broaches.
Decorative dentistry
Goldwork used as decorative dentistry was referred to in the Visayas as "pusad," and was noted by some of the earliest colonial era chroniclers, including Antonio Pigafetta and Fray Andres de Urdaneta. The practice is also commonly referenced in Mindanaoan epic poetry such as the Ulahingan of the Manobo people. Pegs called Bansil were inserted into holes drilled into the tooth, with the visible tip being either simple dot-shape, designed as a collection of overlapping scales, or intricate designs reminiscent of filigree. They were made more visible in light of the practice of staining teeth either black or bright red.
Religious items
Numerous gold artifacts recovered in the Philippines are believed to have ceremonial purposes. Some of these figures indicate the Hindu and Buddhist influence which came to the Philippines through regional trade in maritime southeast asia, while others reflect nature-based religious beliefs.
A notable artifact reflecting indigenous beliefs depicts what has been described as "the large, triangular face of a woman drawn in sharp lines with little shoulders and arms raised in a gesture of worship."
Visayan indigenous healing beliefs are likewise reflected in a particular variant of kamagi necklaces known as "tunga," which were snake-like in shape and made of “half gold and half tumbaga” gears strung together. These were believed to protect the wearer from the "folk illness" known as pasma.
Other notable ceremonial artifacts include: the Agusan Image which depicts a female Hindu or Buddhist deity whose identity is disputed, and the gold kinnari, which shows a mythical half-human half-bird figure common in hindu and buddhist parts of Maritime Southeast Asia.
Death masks and burial goods
Aside from decorative dentistry which they wore in life and carried the grave with them, ranking datus were often buried with items of gold, either in the form of gold burial goods, or as specifically designed funerary art such as death masks.
Burial goods found in graves from early Philippine history includes various beads earrings rings pendants, combs, strips, and other ornaments.
Another gold feature commonly discovered in elite burials from early historic Philippines are death mask artifacts, meant to cover either part or all of the deceased's face in the grave
When this practice was discovered by the Spanish colonizers, they created a rule that a government representative should always be present whenever the Spanish settlers dug up a grave - so that the Spanish government could get its designated 1/5 of the dug up goods.
Burial goods are among the most common surviving gold artifacts in the Philippines because gold which was not buried was typically eventually reforged into other forms as the colonial period proceeded.
Other uses
Accounts of early Spanish colonizers also noted the use of gold as spear decorations in the visayas.
As currency
Aside from use as decorative or utilitarian objects, gold was used throughout the Philippine archipelago as currency, whether in the form of gold dust, small beads, or barter rings.
Piloncitos
Modern day antique collectors have since coined the term "Piloncitos" to describe the small "bead-like" pieces of gold which were used as currency in Precolonial Philippines, comparing the cone-shaped pieces to a pilon of sugar. Early historical descriptions of the term include the Spanish "granitas de oro" (small grains of gold), or simply by whatever local language terms were used to mean "gold" in those times, such as "bulawan."
See also
History of the Philippines (900–1565)
Barter rings
Piloncitos
References
Economic history of the Philippines
Gold
Archaeometallurgy | Gold in early Philippine history | [
"Chemistry",
"Materials_science"
] | 1,427 | [
"Archaeometallurgy",
"Metallurgy"
] |
69,726,840 | https://en.wikipedia.org/wiki/Brusa%20bezistan | Brusa bezistan with its 6 roof domes it is one of the historic buildings in Sarajevo's Baščaršija from the time of the Ottoman period in the history of Bosnia and Herzegovina. It has a rectangular base and has four entrances on all four sides, and connects the craft streets Kundurdžiluk, Veliki and Mali Čurčiluk with Abadžiluk and the Baščaršija. It was built by order of the Grand Vizier Rustem-pasha Opuković in 1551. Bezistan was named after the Turkish city of Bursa, from which silk was brought to Bezistan and sold. Unlike Gazi Husrev-beg's bezistan, where groceries were originally sold, Brusa bezistan sold household items and small furniture in addition to silk. Today it is one of the museums in the city, designated as the National monument of Bosnia and Herzegovina by the Commission to preserve national monuments of Bosnia and Herzegovina, and houses one of the departments of Museum of Sarajevo.
See also
Gazi Husrev Bey
References
External links
Brusa Bezistan - Muzej Sarajeva
Museums in Sarajevo
Stari Grad, Sarajevo
Buildings and structures in Sarajevo
National Monuments of Bosnia and Herzegovina | Brusa bezistan | [
"Engineering"
] | 256 | [
"Architecture stubs",
"Architecture"
] |
69,728,002 | https://en.wikipedia.org/wiki/Mona%20Canyon | Mona Canyon (Spanish: Cañón de la Mona), also known as the Mona Rift, is an submarine canyon located in the Mona Passage, between the islands of Hispaniola (particularly the Dominican Republic) and Puerto Rico, with steep walls measuring between in height from bottom to top. The Mona Canyon stretches from the Desecheo Island platform, specifically the Desecheo Ridge, in the south to the Puerto Rico Trench, which contains some of the deepest points in the Atlantic Ocean, in the north. The canyon is also particularly associated with earthquakes and subsequent tsunamis, with the 1918 Puerto Rico earthquake having its epicenter in the submarine canyon.
Geomorphology
The Mona submarine canyon geomorphology is highly complex yet unexplored. The complex seafloor is the result of oceanographic and tectonic forces that are actively forming and reshaping the landscape of the region. The canyon is located in an intricate and irregular tectonic region at the boundary between the Caribbean and North American plates, where the east–west transversing subduction Septentrional Fault ends in an approximately hole west of the landform.
See also
List of submarine canyons
References
Canyons and gorges of the United States
Geography of Puerto Rico
Landforms of Puerto Rico
Physical oceanography
Submarine canyons of the Atlantic Ocean | Mona Canyon | [
"Physics"
] | 270 | [
"Applied and interdisciplinary physics",
"Physical oceanography"
] |
69,728,897 | https://en.wikipedia.org/wiki/2022%20heat%20waves | In 2022, several areas of the world experienced heat waves. Heat waves were especially notable in East Asia, the Indian subcontinent, Australia, western Europe, the United States, and southern South America. 2022 heat waves accounted for record-breaking temperatures and, in some regions, heat-related deaths. Heat waves were worsened by the effects of climate change, and they exacerbated droughts and wildfires.
Background and effects
Due to climate change, heat waves and other extreme weather events are longer and more intense. In many places, heat waves were accompanied by droughts and wildfires.
Heat waves and droughts affected water supplies, rivers (along with shipping and nuclear reactor cooling), ecosystems, various global supply chains, health, and agriculture worldwide.
By region
Africa
Tunisia
On 13 July in Tunis, the capital city of Tunisia, the temperature reached , worsening wildfires in the country.
Australia
In 14 January in Onslow, Western Australia, the temperature hit . If verified, the temperature would be tied as the highest in the Southern Hemisphere. From 18 to 23 January, Perth experienced six consecutive days with temperatures exceeding . Perth had eleven days of temperatures over during the 2021–2022 summer, topping the previous record of seven days recorded in 2016–2017. In early March, a strong heat wave affected Northern Australia, and in particular North Queensland, with Townsville equalling or beating its previous March minimum temperature record five times in one week.
Asia
China
During 2022, China suffered several heat waves, starting 5 July. According to the China Meteorological Administration, Turpan was expected to reach between 25 and 31 July. China experienced large blackouts and experimented with cloud seeding among other measures, despite experts stating it would be "marginally effective" and possibly exacerbate problems.
India and Pakistan
Starting in late March, India and Pakistan began experiencing one of the hottest periods on record. At least 90 people were killed by the heat wave; 25 in India and 65 in Pakistan.
Japan
On 29 June 2022, Japan saw its worst heat wave in 150 years.
Europe
Heat waves affecting Europe began in June.
Spain
The Spanish heat wave began on 12 June. Spain restricted air conditioning to defined temperature ranges.
United Kingdom
In a heat wave beginning on 8 July, the United Kingdom saw its first ever red extreme heat warning, with a national emergency declared on 15 July. An unconfirmed report from the Met Office on 19 July indicated a new record temperature for the United Kingdom, . This is the first time the temperature exceeded in the United Kingdom.
North America
United States
From 8 to 11 February, multiple cities in central and southern California experienced a record-breaking heat wave. San Francisco recorded on 10 February, an all-time record for the city for meteorological winter. Palm Springs recorded on 11 February.
A historic heat wave affected the Midwest and Southeast in the second week of June. On 13 June, more than 125 million people under excessive heat warnings. Following a brief respite 18 June, the heat wave returned into the following days.
An intense, fatal heat wave swept through the United States in July. More than 100 million people were under heat alert, and over 85% of the country had temperatures at or above . This extreme heat severely intensified drought conditions. The heat wave was responsible for at least 19 deaths, including 12 in Maricopa County, Arizona.
Another heat wave moved across the United States in early August, with 80 million Americans under heat alerts.
The US Bureau of Reclamation said in June that those in the Colorado River Basin would have to create plans to reduce water usage. By the August 15 deadline, the mandate was not being followed and the federal government did not have plans to follow up. Also in August, the US federal government announced that Arizona, Nevada, and Mexico would have to reduce water usage, per a previously negotiated agreement. These cuts were much less than those prescribed by the Bureau of Reclamation.
A record-breaking heat wave broke numerous records across the Eastern United States from November 5-7. Several places set monthly high temperature records on November 7, including Bridgeport, Connecticut and Washington DC.
South America
Southern Cone
From 10 to 16 January, the Southern Cone had a severe heat wave. Argentina, Uruguay, Paraguay, and certain parts of Brazil experienced extreme temperatures, with Argentina suffering the worst impacts. According to the World Meteorological Organization, it affected water, energy supply, and agriculture. Buenos Aires reached and more than 700,000 people lost power. Parts of Argentina reached .
See also
Weather of 2022
2021 heat waves
References
2022-related lists
Weather-related lists | 2022 heat waves | [
"Physics"
] | 928 | [
"Weather",
"Physical phenomena",
"Weather-related lists"
] |
69,729,020 | https://en.wikipedia.org/wiki/NGC%205910 | NGC 5910 is an elliptical galaxy located about 540 million light-years away in the constellation Serpens. It was discovered by astronomer William Hershel on April 13, 1785. NGC 5910 is also a strong radio source with a conspicuous nuclear jet.
Physical characteristics
NGC 5910 appears to have a double nucleus, with a faint nuclear dust lane also being observed.
A pair of asymmetries in the isotopotal profile of NGC 5910 with one of them being brighter than the other, weaker asymmetry suggests a past merger and collision of one or more galaxies.
Group membership
NGC 5910 is the brightest and dominant member of a compact group of galaxies known as Hickson Compact Group 74. The group consists of 5 members in total, with a velocity dispersion of 537 km/s and a diameter of . The other members are 2MASX J15193179+2053005, PGC 54692, PGC 54694, and MCG+04-36-036. The other galaxies appear to be embedded within a common envelope that belongs to NGC 5910.
NGC 5910 appears to lie near the Hercules Superclusters.
Supernovae
Two supernovae have been discovered in NGC 5910: SN 2002ec, and PSN J15192497+2054024.
SN 2002ec
SN 2002ec was discovered in NGC 5910 in July 2002 via unfiltered KAIT CCD images by Li and Beutler. It was located 8.5" east and 12.9" south of the nucleus and was classified as Type la.
PSN J15192497+2054024
PSN J15192497+2054024 was discovered in NGC 5910 on 17 March 2013 by the Catalina Real-Time Transient Survey and Stan Howerton. It was located 2" west and 20" north of the center of NGC 5910 and classified as a type Ia.
See also
List of NGC objects (5001–6000)
NGC 6166
External links
References
5910
054689
Serpens
Astronomical objects discovered in 1785
Elliptical galaxies
Radio galaxies
Hickson 74 | NGC 5910 | [
"Astronomy"
] | 448 | [
"Constellations",
"Serpens"
] |
69,729,976 | https://en.wikipedia.org/wiki/Samarium%28III%29%20arsenide | Samarium(III) arsenide is a binary inorganic compound of samarium and arsenic with the chemical formula SmAs.
Synthesis
Samarium arsenide can be synthesised by heating of pure substances in vacuum:
Physical properties
Samarium arsenide forms crystals of a cubic system, space group Fm3m, cell parameters a = 0.5921 nm, Z = 4, of NaCl-structure.
The compound melts congruently at 2257 °C.
Uses
SmAs is used as a semiconductor and in photo optic applications.
References
Arsenides
Samarium(III) compounds
Semiconductor materials
Rock salt crystal structure | Samarium(III) arsenide | [
"Chemistry"
] | 127 | [
"Semiconductor materials"
] |
69,730,264 | https://en.wikipedia.org/wiki/Biofumigation | Biofumigation is a method of pest control in agriculture, a variant of fumigation where the gaseous active substance—fumigant—is produced by decomposition of plant material freshly chopped and buried in the soil for this purpose.
Plants from the Brassicaceae family (e.g., mustards, cauliflower, and broccoli) are primarily used due to their high glucosinolate content; in the process of decomposition, glucosinolates are broken down to volatile isothiocyanates which are toxic to soil organisms such as bacteria, fungi and nematodes, but less toxic and persistent in the environment than synthetic fumigants. Alternatively, grasses such as sorghum can be used, in which case hydrogen cyanide is produced to similar effect.
The method consists of mowing and chopping the plants during flowering to ensure maximum glucosinolate content and speed up decomposition. The ground needs to be irrigated to field capacity, after which the chopped material is incorporated into the top layer and covered with impermeable film to prevent the gas from escaping. After three or four weeks, the film is removed and the ground is ready for planting 24 hours later. Burying biofumigant crops after the growing season to plant cash crops normally next year may in theory lead to buildup of active substance in the soil after a few cycles of crop rotation, but direct short-term suppression of pests is not notable in this case.
The method can be used as a more sustainable and environment-friendly alternative to classic fumigation and other chemical pest control methods. Additionally, it can serve to replenish the nutrient content of the soil and promote growth of beneficial organisms. On the other hand, it requires changes in cultivation practice due to the time needed for the method to take effect, can be costly if biofumigant-producing plants need to be brought from elsewhere (i. e. if they are not used in crop rotation to be chopped and buried on site), and is difficult to standardize due to varying active substance content in different cultivars.
References
See also
biosolarization
Pest control techniques
Agricultural terminology
Soil science
Soil contamination
Biocides | Biofumigation | [
"Chemistry",
"Biology",
"Environmental_science"
] | 456 | [
"Environmental chemistry",
"Biocides",
"Soil contamination",
"Toxicology"
] |
69,730,341 | https://en.wikipedia.org/wiki/ACT-462206 | ACT-462206 is a dual orexin receptor antagonist (IC50 for OX1 = 60nM, OX2 = 11nM) which has been investigated for the treatment of insomnia. In human trials, ACT-462206 produced dose-dependent sedative effects and was generally well tolerated, with residual sleepiness and headache being the most common adverse events.
Pharmacology
In humans, the sedative effects of ACT-462206 began 45 minutes after oral administration, and dissipated within 8 hours - consistent with a favorable pharmacodynamic profile for the treatment of insomnia. However, the pharmacokinetic profile of ACT-462206 diverges significantly from what would be expected based on behavioral effects. Elevated plasma concentrations of ACT-462206 are sustained for over 24–36 hours after administration - despite behavioral measures of sedation disappearing within 8 hours of administration.
References
Orexin antagonists
Sulfonamides
Amides
4-Methoxyphenyl compounds
Pyrrolidines | ACT-462206 | [
"Chemistry"
] | 221 | [
"Amides",
"Functional groups"
] |
69,730,727 | https://en.wikipedia.org/wiki/Choreographic%20programming | In computer science, choreographic programming is a programming paradigm where programs are compositions of interactions among multiple concurrent participants.
Overview
Choreographies
In choreographic programming, developers use a choreographic programming language to define the intended communication behaviour of concurrent participants. Programs in this paradigm are called choreographies.
Choreographic languages are inspired by security protocol notation (also known as "Alice and Bob" notation). The key to these languages is the communication primitive, for example
Alice.expr -> Bob.x
reads "Alice communicates the result of evaluating the expression expr to Bob, which stores it in its local variable x".
Alice, Bob, etc. are typically called roles or processes.
The example below shows a choreography for a simplified single sign-on (SSO) protocol based on a Central Authentication Service (CAS) that involves three roles:
Client, which wishes to obtain an access token from CAS to interact with Service.
Service, which needs to know from CAS if the Client should be given access.
CAS, which is the Central Authentication Service responsible for checking the Client's credentials.
The choreography is:
Client.(credentials, serviceID) -> CAS.authRequest
if CAS.check(authRequest) then
CAS.token = genToken(authRequest)
CAS.Success(token) -> Client.result
CAS.Success(token) -> Service.result
else
CAS.Failure -> Client.result
CAS.Failure -> Service.result
The choreography starts in Line 1, where Client communicates a pair consisting of some credentials and the identifier of the service it wishes to access to CAS. CAS stores this pair in its local variable authRequest (for authentication request).
In Line 2, the CAS checks if the request is valid for obtaining an authentication token.
If so, it generates a token and communicates a Success message containing the token to both Client and Service (Lines 3–5).
Otherwise, the CAS informs Client and Service that authentication failed, by sending a Failure message (Lines 7–8). We refer to this choreography as the "SSO choreography" in the remainder.
Endpoint Projection
A key feature of choreographic programming is the capability of compiling choreographies to distributed implementations. These implementations can be libraries for software that needs to participate in a computer network by following a protocol, or standalone distributed programs.
The translation of a choreography into distributed programs is called endpoint projection (EPP for short).
Endpoint projection returns a program for each role described in the source choreography. For example, given the choreography above, endpoint projection would return three programs: one for Client, one for Service, and one for CAS. They are shown below in pseudocode form, where send and recv are primitives for sending and receiving messages to/from other roles.
For each role, its code contains the actions that the role should execute to implement the choreography correctly together with the others.
Development
The paradigm of choreographic programming originates from its titular PhD thesis.
The inspiration for the syntax of choreographic programming languages can be traced back to security protocol notation, also known as "Alice and Bob" notation. Choreographic programming has also been heavily influenced by standards for service choreography and interaction diagrams, as well as developments of the theory of process calculi.
Choreographic programming is an active area of research. The paradigm has been used in the study of information flow, parallel computing, cyber-physical systems, runtime adaptation, and system integration.
Languages
AIOCJ (website). A choreographic programming language for adaptable systems that produces code in Jolie.
Chor (website). A session-typed choreographic programming language that compiles to microservices in Jolie.
Choral (website). An object-oriented choreographic programming language that compiles to libraries in Java. Choral is the first choreographic programming language with decentralised data structures and higher-order parameters.
ChoRus (website). Library-level choreographic programming in Rust.
Core Choreographies. A core theoretical model for choreographic programming. A mechanised implementation is available in Coq.
HasChor (website). A library for choreographic programming in Haskell.
Kalas. A choreographic programming language with a verified compiler to CakeML.
Pirouette. A mechanised choreographic programming language theory with higher-order procedures.
See also
Security protocol notation
Sequence diagram
Service choreography
Structured concurrency
Multitier programming
References
External links
www.choral-lang.org
Concurrent computing
Programming paradigms | Choreographic programming | [
"Technology"
] | 954 | [
"Computing platforms",
"Concurrent computing",
"IT infrastructure"
] |
69,730,965 | https://en.wikipedia.org/wiki/Weyl%27s%20inequality%20%28number%20theory%29 | In number theory, Weyl's inequality, named for Hermann Weyl, states that if M, N, a and q are integers, with a and q coprime, q > 0, and f is a real polynomial of degree k whose leading coefficient c satisfies
for some t greater than or equal to 1, then for any positive real number one has
This inequality will only be useful when
for otherwise estimating the modulus of the exponential sum by means of the triangle inequality as provides a better bound.
References
Vinogradov, Ivan Matveevich (1954). The method of trigonometrical sums in the theory of numbers. Translated, revised and annotated by K. F. Roth and Anne Davenport, New York: Interscience Publishers Inc. X, 180 p.
Inequalities
Number theory | Weyl's inequality (number theory) | [
"Mathematics"
] | 172 | [
"Discrete mathematics",
"Binary relations",
"Mathematical relations",
"Inequalities (mathematics)",
"Mathematical problems",
"Mathematical theorems",
"Number theory"
] |
69,731,274 | https://en.wikipedia.org/wiki/De%20Bruijn%20factor | The de Bruijn factor is a measure of how much harder it is to write a formal mathematical proof instead of an informal one. It was created by the Dutch computer-proof pioneer Nicolaas Govert de Bruijn.
De Bruijn computed it as the size of the formal proof over the .
Freek Wiedijk refined the definition to use the compressed size of the formal proof over the compressed size of the informal proof. He called this the "intrinsic de Bruijin Factor". The compression removes the effect that the length of identifiers in the proofs might have.
References
Mathematical logic | De Bruijn factor | [
"Mathematics"
] | 126 | [
"Mathematical logic"
] |
69,732,690 | https://en.wikipedia.org/wiki/Quasimorphism | In group theory, given a group , a quasimorphism (or quasi-morphism) is a function which is additive up to bounded error, i.e. there exists a constant such that for all . The least positive value of for which this inequality is satisfied is called the defect of , written as . For a group , quasimorphisms form a subspace of the function space .
Examples
Group homomorphisms and bounded functions from to are quasimorphisms. The sum of a group homomorphism and a bounded function is also a quasimorphism, and functions of this form are sometimes referred to as "trivial" quasimorphisms.
Let be a free group over a set . For a reduced word in , we first define the big counting function , which returns for the number of copies of in the reduced representative of . Similarly, we define the little counting function , returning the maximum number of non-overlapping copies in the reduced representative of . For example, and . Then, a big counting quasimorphism (resp. little counting quasimorphism) is a function of the form (resp. .
The rotation number is a quasimorphism, where denotes the orientation-preserving homeomorphisms of the circle.
Homogeneous
A quasimorphism is homogeneous if for all . It turns out the study of quasimorphisms can be reduced to the study of homogeneous quasimorphisms, as every quasimorphism is a bounded distance away from a unique homogeneous quasimorphism , given by :
.
A homogeneous quasimorphism has the following properties:
It is constant on conjugacy classes, i.e. for all ,
If is abelian, then is a group homomorphism. The above remark implies that in this case all quasimorphisms are "trivial".
Integer-valued
One can also define quasimorphisms similarly in the case of a function . In this case, the above discussion about homogeneous quasimorphisms does not hold anymore, as the limit does not exist in in general.
For example, for , the map is a quasimorphism. There is a construction of the real numbers as a quotient of quasimorphisms by an appropriate equivalence relation, see Construction of the reals numbers from integers (Eudoxus reals).
Notes
References
Further reading
What is a Quasi-morphism? by D. Kotschick
Group theory
Additive functions | Quasimorphism | [
"Mathematics"
] | 474 | [
"Group theory",
"Fields of abstract algebra"
] |
71,304,143 | https://en.wikipedia.org/wiki/HD%20221420 | HD 221420 (HR 8935; Gliese 4340) is a likely binary star system in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.81, allowing it to be faintly seen with the naked eye. The object is relatively close at a distance of 102 light years but is receding with a heliocentric radial velocity of .
HD 221420 has a stellar classification of G2 IV-V, indicating a solar analogue with a luminosity class intermediate between a subgiant and a main sequence star. The object is also extremely chromospherically inactive. It has a comparable mass to the Sun and a diameter of . It shines with a luminosity of from its photosphere at an effective temperature of , giving a yellow glow. HD 221420 is younger than the Sun at 3.65 billion years. Despite this, the star is already beginning to evolve off the main sequence. Like most planetary hosts, HD 221420 has a metallicity over twice of that of the Sun and spins modestly with a projected rotational velocity .
There is a mid-M-dwarf star with a similar proper motion and parallax to HD 221420, which is likely gravitationally bound to it. The two stars are separated by 698 arcseconds, corresponding to a distance of .
Planetary system
In a 2019 doppler spectroscopy survey, an exoplanet was discovered orbiting the star. The planet was originally thought to be a super Jupiter, having a minimum mass of . However, later observations using Hipparcos and Gaia astrometry found it to be a brown dwarf with a high-inclination orbit, revealing a true mass of .
References
G-type main-sequence stars
G-type subgiants
Octans
Planetary systems with one confirmed planet
Brown dwarfs
221420
116250
8935
PD-78 01473
4340
Octantis, 83 | HD 221420 | [
"Astronomy"
] | 397 | [
"Octans",
"Constellations"
] |
71,306,402 | https://en.wikipedia.org/wiki/Aston%E2%80%93Greenburg%20rearrangement | The Aston–Greenburg rearrangement is a name reaction in organic chemistry. It allows for the generation of tertiary α-alkylesters from corresponding α-haloketones through a 1,2-rearrangement, with the use of an alkoxide.
References
Name reactions
Rearrangement reactions | Aston–Greenburg rearrangement | [
"Chemistry"
] | 64 | [
"Name reactions",
"Chemical reaction stubs",
"Rearrangement reactions",
"Organic reactions"
] |
71,307,426 | https://en.wikipedia.org/wiki/Jianguo%20Liu | Jianguo Liu (; born 1963) is a Chinese American ecologist and sustainability scientist specializing in the human-environment and sustainability studies. He is University Distinguished Professor at Michigan State University.
Early life and education
Liu was born in Hunan Province, Southern China, in 1963. He received a B.S. in plant protection at Hunan Agricultural University in 1983, an M.S. in ecology at the Chinese Academy of Sciences in Beijing in 1986, and a PhD in ecology (with focus on ecological economics) from the University of Georgia in 1992. He did his postdoctoral study at Harvard University during 1992-1994.
Career
Liu joined the faculty of Michigan State University in 1995. He has been the Rachel Carson Chair in Sustainability since 2004 and University Distinguished Professor since 2005. In 2004, he became the founding director of the Center for Systems Integration and Sustainability.
Liu was a visiting scholar (on sabbatical) at Stanford University (2001-2002), Harvard University (2008), and Princeton University (2009). He has also been a research affiliate with the Institute of Social Research at the University of Michigan – Ann Arbor since 2002.
Research
Liu has published approximately 400 journal articles, book chapters, and books, in collaboration with hundreds of students and scholars around the world. His publications cover a variety of topics, such as telecoupling, systems integration, sustainability, protected areas, biodiversity, ecosystem restoration, ecosystem services, forest dynamics, drivers of environmental change (e.g. divorce and household proliferation), coupled human and natural systems, ecology, ecological economics, conservation, environment, food systems, land use and land cover change, landscapes, metacoupling, climate change impact, nature-based climate solutions (e.g., natural carbon capture and sequestration), natural resources (e.g., bioenergy, forests, land, water), sociology (e.g., social norms), sustainable development goals, systems modeling, technology (e.g., AI, geographic information systems, machine learning, remote sensing), and wildlife. Below are a few highlights.
Selected publications
Liu, Jianguo (2023). "Leveraging the metacoupling framework for sustainability science and global sustainable development". National Science Review 10(7), nwad090.
Liu, Jianguo, Thomas Dietz, Stephen R. Carpenter, William W. Taylor, Marina Alberti, Peter Deadman, Charles Redman, Alice Pell, Carl Folke, Zhiyun Ouyang, and Jane Lubchenco (2021). "Coupled Human and Natural Systems: The evolution and applications of an integrated framework". Ambio''' 50:1778-1783.
Xu, Zhenci, Sophia N. Chau, Xiuzhi Chen, Jian Zhang, Yingjie Li, Thomas Dietz, Jinyan Wang, Julie A. Winkler, Fan Fan, Baorong Huang, Shuxin Li, Shaohua Wu, Anna Herzberger, Ying Tang, Dequ Hong, Yunkai Li and Jianguo Liu (2020)." Assessing progress towards sustainable development over space and time". Nature. 577 (7788): 74-78.
Liu, Jianguo (2020) Telecoupling. In: The International Encyclopedia of Geography: People, the Earth, Environment, and Technology. Edited by Douglas Richardson, Noel Castree, Michael F. Goodchild, Audrey Kobayashi, Weidong Liu, and Richard A. Marston. John Wiley & Sons, Ltd.
Liu, Jianguo, Vanessa Hull, H. Charles J. Godfray, David Tilman, Peter Gleick, Holger Hoff, Claudia Pahl-Wostl, Zhenci Xu, Min Gon Chung, Jing Sun and Shuxin Li (2018). "Nexus approaches to global sustainable development". Nature Sustainability 1(9):466–476.
Liu, Jianguo (2017). "Integration across a metacoupled world". Ecology and Society 22(4):29.
Liu, Jianguo; Mooney, Harold; Hull, Vanessa; Davis, Steven J.; Gaskell, Joanne; Hertel, Thomas; Lubchenco, Jane; Seto, Karen C.; Gleick, Peter; Kremen, Claire; Li, Shuxin (2015). "Systems integration for global sustainability". Science 347 (6225):1258832.
Liu, Jianguo, Vanessa Hull, Mateus Batistella, Ruth DeFries, Thomas Dietz, Feng Fu, Thomas W. Hertel, R. Cesar Izaurralde, Eric F. Lambin, Shuxin Li, Luiz A. Martinelli, William J. McConnell, Emilio F. Moran, Rosamond Naylor, Zhiyun Ouyang, Karen R. Polens (2013). "Framing sustainability in a telecoupled world". Ecology and Society 18(2):26.
Yu, Eunice and Jianguo Liu (2007). "Environmental Impacts of Divorce". PNAS 104(51):20629–20634.
Liu, Jianguo, Thomas Dietz, Stephen R. Carpenter, Marina Alberti, Carl Folke, Emilio Moran, Alice N. Pell, Peter Deadman, Timothy Kratz, Jane Lubchenco, Elinor Ostrom, Zhiyun Ouyang, William Provencher, Charles L. Redman, Stephen H. Schneider, William W. Taylor (2007). "Complexity of Coupled Human and Natural Systems". Science 317(5844):1513-1516.
Liu, Jianguo & Jared Diamond (2005). "China's environment in a globalizing world". Nature 435:1179-86.
Liu, Jianguo, Gretchen C. Daily, Paul R. Ehrlich and Gary W. Luck (2003). "Effects of household dynamics on resource consumption and biodiversity". Nature 421:(530–533).
Liu, Jianguo; Marc Linderman; Zhiyun Ouyang; Li An; Jian Yang; Hemin Zhang (2001). "Ecological degradation in protected areas: The Case of Wolong Nature Reserve for Giant Pandas" Science'' 292(5514):98-101.
Honors and awards
Top Cited Scholar according to Scilit
Highly Ranked Scholar according to ScholarGPS
Highly Cited Researcher according to Clarivate Analytics
Member, Royal Norwegian Society of Sciences and Letters, 2022
Eminent Ecologist Award, 2022
Gunnerus Award in Sustainability Science, 2021
World Sustainability Award (with John Elkington), 2021
Special Tribute, State of Michigan, 2021
Innovations in Sustainability Science Award, 2020
Fellow, American Academy of Arts and Sciences, 2018
Distinguished Landscape Ecologist Award, 2018
Fellow, Ecological Society of America, 2018
“Highly Cited Researcher”, Clarivate Analytics, 2018
Sustainability Science Award, 2017
Member, American Philosophical Society, 2015
Fellow, American Association for the Advancement of Science, 2010
Ralph H. Smuckler Award for Advancing International Studies and Programs, 2007
Guggenheim Fellowship, 2006
Distinguished Service Award, 2006
Distinguished Faculty Award, 2005
Teacher-Scholar Award, 2002
Aldo Leopold Leadership Fellow, 2001
National Science Foundation CAREER Award, 1997
References
1963 births
Living people
Michigan State University faculty
Fellows of the Ecological Society of America
Scientists from Hunan
Fellows of the American Association for the Advancement of Science
Fellows of the American Academy of Arts and Sciences
Hunan Agricultural University alumni
University of Georgia alumni
Sustainability scientists
Members of the American Philosophical Society
Chinese expatriates in the United States | Jianguo Liu | [
"Environmental_science"
] | 1,554 | [
"Sustainability scientists",
"Environmental scientists"
] |
71,307,448 | https://en.wikipedia.org/wiki/Garbhanga%20Wildlife%20Sanctuary | Garbhanga Wildlife Sanctuary (formerly Garbhanga and Rani Reserve Forest) is a wildlife sanctuary on the southwestern side of Guwahati City, bordering the state of Meghalaya, India. The forested area is the key urban wildlife site and catchment area near Guwahati City.
Located approximately 15 km (10 miles) away from Guwahati, Garbhanga Wildlife Sanctuary is situated in the southern part of Assam, bordering the foothills of Meghalaya. It is located very close to the Deepor Bill, and because of its location in an urban area it is considered a key wildlife area of Guwahati City.
Garbhanga Wildlife Sanctuary has a total land area of 117 km2 and lies between the Garbhanga and Rani ranges.
Etymology
The origin of wildlife sanctuary's name is unclear. However, some believe that the name comes from the Karbi people, who came from the Markang area of Sonapur and eventually entered the hilly forest for Jhum cultivation.
Garbhanga was declared a wildlife sanctuary by the second secretary to the government of Assam, Mr G.T. Lloyd. He was under the supervision of Major Briggs, who surveyed the forest in 1862.
Brief boundary description
The Garbhanga Wildlife Sanctuary is surrounded by Guwahati City and Dipor Bill in the South, the Meghalayan ranges on the east and north, and Rani Range on the west.
North
The northern boundary starts at BSF headquarters near the VIP Road, then runs along the foothills of Matia, Chakradeo, Dipor Bil, Mahua Para, Pamohi, and Mainakhurung up to Paschdhora River, which is the common boundary between Garbhanga Reserve Forest and Rani Reserve Forest. From there, the boundary runs along Phalbama, Nawagaon, and Nalapara, up to Lokhara Village and to the Siva Temple, which is situated in the northeast corner.
East
On the east side, the boundary runs along the Basistha river, up to the front side of the Government Art School and then follows the stream. Permanent boundary pillars are situated near the Basistha River, then the eastern boundary runs up to Umthana Forest Camp. The name of the river changes in different locations, such as Umsing, Umpani, Umrit etc. This entire stretch is the interstate boundary with Meghalaya.
South
The southern boundary starts at Doomati village, which is the joining point of Umrit and Umsopari rivers. From there, the boundary runs up to Pathar Khama, then up to Rangang River that runs out from Meghalaya.
West
The western boundary starts at Pathar Khama, then goes up Jeepable Fair Weather Road along the Umsang River. From this point the boundary runs along Naharpaham, Bhadiakhowa, where it meets Umtru River, and then the boundary follows the stream to where it meets Kapili river. The boundary then runs along Ganapati, Rani, Bahupara, Andherijuli, Rani Tea estate, Sajanpara, Patgaon, to where it meets at the starting point at the corner of BSF Headquarters.
Landscape and biodiversity
In earlier days, various NGOs and researchers witnessed rare animals such as serow, clouded leopard, and bison and wanted to study Garbhanga. Therefore, when the Working Plan of the Kamrup East Division was prepared, an attempt was made to document the faunal and flora diversity of Garbhanga and Rani Reserve Forest.
Flora
The wildlife sanctuary has diverse flora. A study has found 139 species of trees, 122 herbs and shrubs, 52 species of climbers, 11 species of orchids, and five species of bamboo and rattan were documented.
Fauna
The wildlife sanctuary is rich in fauna. A total of 36 species of mammals, 219 species of birds, 38 species of reptiles, 15 species of amphibians, 168 species of butterflies, and 15 species of spiders have been documented.
Disturbance and threats
In May 2005, at the 15th Annual Meeting of Early Bird, a local NGO warned the Assam government about the danger of losing the wildlife sanctuary in the future.
The main threats to wildlife are encroachment, dumping of garbage, and deforestation.
The NGO requested that the government prevent the encroachment on wild animals and also called for a ban on the dumping of garbage in the wetlands.
Present status
Groups have been constantly demanding the upgrading of Garbhanga-Rani Reserved Forests into a wildlife sanctuary for its better protection and care.
Hydrological considerations - Protection of the watershed areas of Guwahati city and its adjacent areas would regulate water flow, maintain water quality and nutrient cycles, and prevent soil erosion and sedimentation.
Genetic and species considerations - Protection of wild gene pools of flora and diverse avian, mammalian, reptilian, and other fauna.
Ethnobotanical considerations - Protection of medicinal plants traditionally used by tribal communities residing in and around the forested areas.
Economic considerations - Protection and maintenance of the areas with high scenic value for eco-tourism, which would provide economic opportunity to ethnic tribal inhabitants.
Declared a wildlife sanctuary
On 7 April 2022, in the Assam Gazette, the governor of Assam proposed that Garbangha Reserved Forest should be declared a wildlife sanctuary, which made it the 25th wildlife sanctuary in Assam.
References
Tourism in Northeast India
Tourism in Assam
Geography of Assam
Important Bird Areas of India
Biosphere reserves of India
Biodiversity | Garbhanga Wildlife Sanctuary | [
"Biology"
] | 1,126 | [
"Biodiversity"
] |
71,307,878 | https://en.wikipedia.org/wiki/Poisson-Dirichlet%20distribution | In probability theory, Poisson-Dirichlet distributions are probability distributions on the set of nonnegative, non-increasing sequences with sum 1, depending on two parameters and . It can be defined as follows. One considers independent random variables such that follows the beta distribution of parameters and . Then, the Poisson-Dirichlet distribution of parameters and is the law of the random decreasing sequence containing and the products . This definition is due to Jim Pitman and Marc Yor. It generalizes Kingman's law, which corresponds to the particular case .
Number theory
Patrick Billingsley has proven the following result: if is a uniform random integer in , if is a fixed integer, and if are the largest prime divisors of (with arbitrarily defined if has less than prime factors), then the joint distribution ofconverges to the law of the first elements of a distributed random sequence, when goes to infinity.
Random permutations and Ewens's sampling formula
The Poisson-Dirichlet distribution of parameters and is also the limiting distribution, for going to infinity, of the sequence , where is the length of the largest cycle of a uniformly distributed permutation of order . If for , one replaces the uniform distribution by the distribution on such that , where is the number of cycles of the permutation , then we get the Poisson-Dirichlet distribution of parameters and . The probability distribution is called Ewens's distribution, and comes from the Ewens's sampling formula, first introduced by Warren Ewens in population genetics, in order to describe the probabilities associated with counts of how many different alleles are observed a given number of times in the sample.
References
Probability distributions | Poisson-Dirichlet distribution | [
"Mathematics"
] | 355 | [
"Functions and mappings",
"Mathematical relations",
"Mathematical objects",
"Probability distributions"
] |
71,308,064 | https://en.wikipedia.org/wiki/Corundum%20%28structure%29 | Corundum is the name for a structure prototype in inorganic solids, derived from the namesake polymorph of aluminum oxide (α-Al2O3). Other compounds, especially among the inorganic solids, exist in corundum structure, either in ambient or other conditions. Corundum structures are associated with metal-insulator transition, ferroelectricity, polar magnetism, and magnetoelectric effects.
Structure
The corundum structure has the space group . It typically exists in binary compounds of the type A2B3, where A is metallic and B is nonmetallic, including sesquioxides (A2O3), sesquisulfides (A2S3), etc. When A is nonmetallic and B is metallic, the structure becomes the antiphase of corundum, called the anticorundum structure type, with examples including β-Ca3N2 and borates. Ternary and multinary compounds can also exists in the corundum structure. The corundum-like structure with the composition A2BB'O6 is called double corundum. A list of examples are tabulated below.
See also
Corundum
Ilmenite
Perovskite (structure)
References
Crystal structure types
Crystallography
Mineralogy | Corundum (structure) | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 277 | [
"Crystallography",
"Materials science",
"Condensed matter physics",
"Crystal structure types"
] |
71,308,572 | https://en.wikipedia.org/wiki/Britzelmayria%20multipedata | Britzelmayria multipedata is a species of mushroom producing fungus in the family Psathyrellaceae. It is commonly known as the clustered brittlestem.
Taxonomy
It was first described in 1905 by the American mycologist Charles Horton Peck who classified it as Psathyra multipedata. It was reclassified as Psathyrella multipedata in 1941 by the American mycologistAlexander H. Smith and remained known as such until recently. In 2020 the German mycologists Dieter Wächter & Andreas Melzer reclassified many species in the Psathyrellaceae family based on phylogenetic analysis and placed this species in the newly created genus Britzelmayria.
Many mushroom field guides and websites still refer to this species as Psathyrella multipedata.
Description
Britzelmayria multipedata is a small brittlestem mushroom with white flesh and a brown cap which is known for growing in dense clusters.
Cap: 1-3cm. Starts conical before flattening into a convex cap which may become campanulate or bell shaped with age. The smooth, brown cap becomes paler when dry. Gills: Adnate or adnexed. Crowded. Light grey or brown with white fringes maturing to dark brown. Stem: 7-12cm in height with a thickness of 3-6mm tapering slightly towards the cap. It often grows in a wavy fashion with the base fused together with other members of the cluster. Spore print: Dark purplish brown. Spores: Ellipsoid and smooth with a germ pore. 6.5-10 x 3.5-4 μm. Taste: Indistinct and mild. Smell: Faint and mushroomy.
Habitat and distribution
Britzelmayria multipedata is found on soil amongst grass and in open grassy spaces amongst woodland. It is saprotrophic and grows on buried fallen trees through the late Summer to Autumn. This species is widespread and found occasionally.
Observations of this species appear most common in the UK, West Europe and the East Coast of the United States.
References
multipedata
Fungus species | Britzelmayria multipedata | [
"Biology"
] | 430 | [
"Fungi",
"Fungus species"
] |
71,308,823 | https://en.wikipedia.org/wiki/Capability%20curve | Capability curve of an electrical generator describes the limits of the active (MW) and reactive power (MVAr) that the generator can provide. The curve represents a boundary of all operating points in the MW/MVAr plane; it is typically drawn with the real power on the horizontal axis, and, for the synchronous generator, resembles a letter D in shape, thus another name for the same curve, D-curve. In some sources the axes are switched, and the curve gets a dome-shaped appearance.
Synchronous generators
For a traditional synchronous generator the curve consists of multiple segments, each due to some physical constraint:
at the right part of the curve (close to the rated voltage), the generator is constrained by the heat dissipation in the armature (stator for large generators). The heating is proportional to the sum of squares of active and reactive currents, at the near-constant voltage it is closely proportional to the sum of squares of MW and MVAr, therefore this part of the curve (armature heating limit) resembles a section of a semicircle with the center at (0,0);
at the upper part of the curve (generator produces a lot of reactive power) operation requires higher voltage on the output of the generator and thus higher excitation field. The rotating excitation winding has its own field heating limit;
at the bottom of the curve (generator absorbs a lot of reactive power) the magnetic flux constraints in the stator cause heating of the magnetic core at the stator end (core end heating limit).
The corners between the sections of the curve define the limits of the power factor (PF) that the generator can sustain at its nameplate capacity (the illustration has the PF ticks placed at 0.85 lagging and 0.95 leading angles). In practice, the prime mover (a power source that drives the generator) is designed for less active power than the generator is capable of (due to the fact that in real life generator always has to deliver some reactive power), so a prime mover limit (a vertical dashed line on the illustration) changes the constraints somewhat (in the example, the leading PF limit, now at the intersection of the prime mover limit and core end heating limit, lowers to 0.93.
Due to high cost of a generator, a set of sensors and limiters will trigger the alarm when the generator approaches the capability-set boundary and, if no action is taken by the operator, will disconnect the generator from the grid.
The D-curve for a particular generator can be expanded by improved cooling. Hydrogen-cooled turbo generator's cooling can be improved by increasing the hydrogen pressure, larger generators, from 300 MVA, use more efficient water cooling.
The practical D-curve of a typical synchronous generator has one more limitation, minimum load. The minimum real power requirement means that the left-side of a D-curve is detached from the vertical axis. Although some generators are designed to be able to operate at zero load (as synchronous condensers), operation at real power levels between zero and the minimum is not possible even with these designs.
Wind and solar photovoltaics generators
The inverter-based resources (like solar photovoltaic (PV) generators, doubly-fed induction generators and full-converter wind generators, also known as "Type 3" and "Type 4" turbines) need to have reactive capabilities in order to contribute to the grid stability, yet their contribution is quite different from the synchronous generators and is limited by internal voltage, temperature, and current constraints. Due to flexibility allowed by the presence of the power converter, the doubly-fed and full-converter wind generators on the market have different shapes of the capability curve: "triangular", "rectangular", "D-shape" (the latter one resembles the D-curve of a synchronous generator). The rectangular and D-shapes of the curve theoretically allow using the generator to provide voltage regulation services even when the unit does not produce any active energy (due to low wind or no sun), essentially working as a STATCOM, but not all designs include this feature. The fixed speed wind turbines without a power converter (also known as "Type 1" and "Type 2") cannot be used for voltage control. They simply absorb the reactive power (like any typical induction machine), so a switched capacitor bank is usually used to correct the power factor to unity.
Older PV generators were intended for distribution networks. Since the current state of these networks does not include the voltage regulation, the inverters in these units were operating at the unity power factor. When the PV devices started to appear in the transmission networks, the inverters with reactive power capability appeared on the market. Since the power limit of an invertor is based on the maximum total current, the natural shape of the capability curve is similar to a semicircle, and at full capacity the real power always needs to be lowered if the reactive power is to be produced or absorbed. Theoretically the PV generators can be used as STATCOMs, although in practice the solar plants are disconnected at night.
Effects on electricity pricing
For a synchronous generator operating inside its D-curve, the marginal cost of providing reactive power is close to zero. However, once the generator's operating point reaches the corners of the D-curve, increasing the reactive power output will require reduction of the real (active) power. Since the electricity markets payments are typically based on real power, the generating company will have a disincentive to provide more reactive power if requested by the independent system operator. Therefore the reactive power management (voltage control) is separated into an ancillary service with its own tariffs, like the Reactive Supply and Voltage Control from Generation Sources (GSR) in the US.
References
Sources
Electrical generators | Capability curve | [
"Physics",
"Technology"
] | 1,227 | [
"Physical systems",
"Electrical generators",
"Machines"
] |
71,309,638 | https://en.wikipedia.org/wiki/Cystoagaricus%20strobilomyces | Cystoagaricus strobilomyces is a species of mushroom producing fungus in the family Psathyrellaceae and the type species of the Cystoagaricus genus
Taxonomy
It was first described in 1945 by the American mycologist William Murrill who discovered the species in Florida and classified it as Nolanea strobilomyces.
In 1947 the German mycologist Rolf Singer created the new genus Cystoagaricus and placed this species within it.
Etymology
The specific epithet strobilomyces derives from this mushroom's resemblance to members of the Strobilomyces genus as a result of the spiky squamules on the cap.
Description
Cystoagaricus strobilomyces is a small mushroom with grey flesh which possesses distinctive scales or spikes on the cap.
Cap: 4-30mm. Convex, umbonate or campanulate. Grey to brown in colour with squamules (spikes or scales) which contrast the cap. Gills: Start grey discolouring through pale blue and dark brown as it ages. Adnate or adnexed. Stem: 5-40 tall and 1-3mm in diameter. Grey and covered in scales or woolly tufts. Spore print: Dark brown. Spores: Phaeseoliform (bean shaped), mitriform. 6–7.5 x 5-6 μm.
References
strobilomyces
Fungi described in 1947
Fungus species | Cystoagaricus strobilomyces | [
"Biology"
] | 300 | [
"Fungi",
"Fungus species"
] |
71,309,809 | https://en.wikipedia.org/wiki/Heterostrain | The term heterostrain was proposed in 2018 in the context of materials science to simplify the designation of possible strain situations in van der Waals heterostructures where two (or more) two-dimensional materials are stacked on top of each other. These layers can experience the same deformation (homostrain) or different deformations (heterostrain). In addition to twist, heterostrain can have important consequences on the electronic and optical properties of the resulting structure. As such, the control of heterostrain is emerging as a sub-field of straintronics in which the properties of 2D materials are controlled by strain. Recent works have reported a deterministic control of heterostrain by sample processing or with the tip of an AFM of particular interest in twisted heterostructures. Heterostrain alone (without twist) has also been identified as a parameter to tune the electronic properties of van der Waals structures as for example in twisted graphene layers with biaxial heterostrain.
Etymology
Heterostrain is constructed from the Greek prefix hetero- (different) and the noun strain. It means that the two layers constituting the structure are subject to different strains. This is in contrast with homostrain in which the two layers as subject to the same strain. Heterostrain is designated as "relative strain" by some authors.
Manifestation and measurement of heterostrain
For simplicity, the case of two graphene layers is considered. The description can be generalized for the case of different 2D materials forming an heterostructure.
In nature, the two graphene layers usually stack with a shift of half a unit cell. This configuration is the most energetically favorable and is found in graphite. If one layer is strained while the other is left intact, a moiré pattern signaling the regions where the atomic lattices of the two layers are in or out of registry. The shape of the moiré pattern depends on the type of strain.
If the layer is deformed along one direction (uniaxial heterostrain), the moiré is one dimensional.
If the layer is strained in the same way along two directions (biaxial heterostrain), the moiré is a two-dimensional superstructure.
In General, a layer can be deformed by an arbitrary combination of both types of heterostrain.
Heterostrain can be measured by scanning tunneling microscope which provides images showing both the atomic lattice of the first layer and the moiré superlattice. Relating the atomic lattice to the moiré lattice allows to determine entirely the relative arrangement of the layers (biaxial, uniaxial heterostrain and twist). The method is immune to calibration artifacts which affect the image of the two layers identically which cancels out in the relative measurement. Alternatively, with a well calibrated microscope and if biaxial heterostrain is low enough, it is possible to determine twist and uniaxial heterostrain from the knowledge of the moiré period in all directions. On the contrary it is much more difficult to determine homostrain which necessitates a calibration sample.
Origin and impact of heterostrain
Heterostrain is generated during the fabrication of the 2D materials stack. It can result from a meta-stable configuration during bottom up assembly or from the layer manipulation in the tear and stack technique. It has been shown to be ubiquitous in twisted graphene layers near the magic twist angle and to be the main factor in the flat band width of those systems. Heterostrain has a much larger impact on electronic properties than homostrain. It explains some of the sample variability which had previously been puzzeling. Research is now moving towards understanding the impact of spatial fluctuations of heterostrain.
References
Deformation (mechanics)
Materials science | Heterostrain | [
"Physics",
"Materials_science",
"Engineering"
] | 778 | [
"Deformation (mechanics)",
"Applied and interdisciplinary physics",
"Materials science",
"nan"
] |
71,310,580 | https://en.wikipedia.org/wiki/Lucifera%20butyrica | Lucifera is a genus of bacteria in the Sporomusaceae family. Sanchez-Andrea et al. in 2018 described a novel species of a novel genus, for which they proposed the name Lucifera butyrica.
Etymology
The name Lucifera, Latin for "Light-bringing", refers to the bacterium's shape which is like a match, and the old term "Lucifer" for a match.
References
Taxa described in 2018
Negativicutes | Lucifera butyrica | [
"Biology"
] | 95 | [
"Bacteria stubs",
"Bacteria"
] |
71,313,162 | https://en.wikipedia.org/wiki/Redmi%2010C | The Redmi 10C is an Android-based smartphone as part of the Redmi series, a sub-brand of Xiaomi Inc. The phone was announced on March 21, 2022, and is marketed as a lite version of Redmi 10 being at the same time better in some specifications.
In India, the Redmi 10C was introduced as the Redmi 10 (not to be confused with the global Redmi 10 which is sold in India as Redmi 10 Prime) with a bigger battery. It succeeds the Indian version of the Redmi 9 (Redmi 9C NFC without NFC chip), which was released in August 2020.
Also, exclusively for was released the Redmi 10 Power which has more memory capacity than the Indian Redmi 10 and a different back.
Design
The front of the smartphones is made of Gorilla Glass 3. The back is made of plastic with a wavy texture on the Redmi 10C and Indian Redmi 10 and with a leather-like texture on the Redmi 10 Power.
The design of smartphones is similar to the realme narzo 50A with a camera unit merged with a fingerprint sensor.
On the bottom of the smartphones, there is a USB-C port, a loudspeaker, and a microphone. On the top is a 3.5mm audio jack. On the left, there is a dual SIM tray with microSD slot. On the right, there is the volume rocker and the power button.
The phones were sold in the following color options:
Specifications
Hardware
Platform
The smartphones feature the Qualcomm Snapdragon 680 4G with the Adreno 610, like the Redmi Note 11.
Battery
The smartphones use non-removable batteries with a capacity of 5000 mAh in the Redmi 10C and with a capacity of 6000 mAh in the Indian Redmi 10 and Redmi 10 Power. All models have 18 W fast charging support but in-box charger has a power of 10 W.
Camera
The smartphones have a dual rear camera with a 50 MP, wide camera and a 2 MP, depth sensor, and a 5 MP, front camera. The rear and front cameras can record video in 1080p@30 fps.
Display
The phones feature a 6.71-inch IPS LCD display with HD+ (1650 × 720; ~269 ppi) image resolution and a waterdrop notch.
Memory
The Redmi 10C was sold in 3/64, 4/64 or 4/128 GB configurations; the Indian Redmi 10 in 4/64 and 4/128 GB configurations; Redmi 10 Power in 8/128 GB configuration.
All models have LPDDR4X type RAM and UFS 2.2 type storage which could be extended by a microSD up to 1 TB.
Software
The smartphones were released with MIUI 13 custom skin based on Android 11 and later they were updated to MIUI 14 based on Android 13.
References
External links
Android (operating system) devices
Phablets
10C
Mobile phones introduced in 2022
Mobile phones with multiple rear cameras
Discontinued smartphones | Redmi 10C | [
"Technology"
] | 633 | [
"Crossover devices",
"Phablets"
] |
71,313,889 | https://en.wikipedia.org/wiki/Laplace%27s%20approximation | Laplace's approximation provides an analytical expression for a posterior probability distribution by fitting a Gaussian distribution with a mean equal to the MAP solution and precision equal to the observed Fisher information. The approximation is justified by the Bernstein–von Mises theorem, which states that, under regularity conditions, the error of the approximation tends to 0 as the number of data points tends to infinity.
For example, consider a regression or classification model with data set comprising inputs and outputs with (unknown) parameter vector of length . The likelihood is denoted and the parameter prior . Suppose one wants to approximate the joint density of outputs and parameters . Bayes' formula reads:
The joint is equal to the product of the likelihood and the prior and by Bayes' rule, equal to the product of the marginal likelihood and posterior . Seen as a function of the joint is an un-normalised density.
In Laplace's approximation, we approximate the joint by an un-normalised Gaussian , where we use to denote approximate density, for un-normalised density and the normalisation constant of (independent of ). Since the marginal likelihood doesn't depend on the parameter and the posterior normalises over we can immediately identify them with and of our approximation, respectively.
Laplace's approximation is
where we have defined
where is the location of a mode of the joint target density, also known as the maximum a posteriori or MAP point and is the positive definite matrix of second derivatives of the negative log joint target density at the mode . Thus, the Gaussian approximation matches the value and the log-curvature of the un-normalised target density at the mode. The value of is usually found using a gradient based method.
In summary, we have
for the approximate posterior over and the approximate log marginal likelihood respectively.
The main weaknesses of Laplace's approximation are that it is symmetric around the mode and that it is very local: the entire approximation is derived from properties at a single point of the target density. Laplace's method is widely used and was pioneered in the context of neural networks by David MacKay, and for Gaussian processes by Williams and Barber.
References
Further reading
Statistical approximations
Bayesian inference | Laplace's approximation | [
"Mathematics"
] | 447 | [
"Statistical approximations",
"Mathematical relations",
"Approximations"
] |
71,314,483 | https://en.wikipedia.org/wiki/Muellerella%20thalamita | Muellerella thalamita is a species of lichenicolous fungus in the family Verrucariaceae. It grows on the apothecia of Orcularia insperata, Baculifera micromera and Hafellia disciformis, which are lichens that grow on bark.
References
Verrucariales
Fungi described in 1877
Lichenicolous fungi
Taxa named by James Mascall Morrison Crombie
Fungus species | Muellerella thalamita | [
"Biology"
] | 94 | [
"Fungi",
"Fungus species"
] |
71,314,745 | https://en.wikipedia.org/wiki/Endococcus%20nanellus | Endococcus nanellus is a species of lichenicolous fungus in the order Dothideales. It is known from Alaska, Canada, Greenland, Hawaii, Japan, Russia, South-Korea, and Kazakhstan.
Host species
Endococcus nanellus is known to infect numerous species of the genus Stereocaulon, including the following species:
Stereocaulon alpinum
Stereocaulon botryosum
Stereocaulon glareosum
Stereocaulon grande
Stereocaulon myriocarpum
Stereocaulon nigrum
Stereocaulon paschale
Stereocaulon saxatile
Stereocaulon tomentosum
Stereocaulon vesuvianum
References
Fungi described in 1891
Fungi of Canada
Fungi of Greenland
Fungi of Japan
Fungi of Kazakhstan
Fungi of Russia
Fungi of South Korea
Fungi of the United States
Dothideales
Taxa named by Otto Ludwig Arnold Ohlert
Fungus species | Endococcus nanellus | [
"Biology"
] | 190 | [
"Fungi",
"Fungus species"
] |
71,314,972 | https://en.wikipedia.org/wiki/Cerberus%20Privy | The Cerberus Privy, at Gayhurst House, Buckinghamshire, England, is a communal lavatory built for the male servants of the house. It was constructed between 1859-1860 and was designed by William Burges. Now converted to a private home, it is a Grade II* listed building.
History
Gayhurst House was built in the early sixteenth-century on the site of a Roman villa and Norman manor. It was expanded in 1597 by William Moulsoe. The house was completed by his son-in-law, Sir Everard Digby, one of the conspirators involved in the Gunpowder Plot. In 1704 the estate was sold to Sir Nathan Wrighte.
The house was extensively refurbished, 1858–72, by William Burges for Robert Carrington, 2nd Baron Carrington, and his son. Lord Carrington was Burges' first significant patron. In total, some £30,000 was spent which did not include the costs of construction for Burges' planned main staircase that was never built. However, a minor stair, the Caliban Stair, was constructed.
The Cerberus Privy was built as a communal lavatory for the male servants of the house. Burges's biographer, J. Mordaunt Crook, considers it "one of Burges's happiest inventions." The Gayhurst estate was broken up in the twentieth century and the house was converted into flats, and the estate buildings including the privy were developed into houses, between 1971 and 1979. The estate is privately owned and is not open to the public, although the house can be seen from the footpath to the adjacent Church of St Peter.
Architecture and description
Nikolaus Pevsner and Elizabeth Williamson, in their 2003 revised edition, Buckinghamshire, of the Pevsner Buildings of England suggest Burges's main design influence for the privy was the Abbot's Kitchen, Glastonbury. The building is circular and consists of a main storey, with a dormer attic above. Atop this is a statue of Cerberus, which originally had eyes made of red glass. Crook calls it; "a picturesque convenience, dedicated to a cloacal demon with billiard ball eyes, for a patron with plumbing on the brain".
The Cerberus Privy is a Grade II* listed building.
Notes
References
Sources
External links
1860 establishments in England
Buildings and structures completed in 1860
1860 sculptures
Gothic Revival architecture in Buckinghamshire
Grade II* listed buildings in Buckinghamshire
Milton Keynes
William Burges buildings
Sculptures of Greek mythology
Cerberus
Toilets | Cerberus Privy | [
"Biology"
] | 523 | [
"Excretion",
"Toilets"
] |
71,315,000 | https://en.wikipedia.org/wiki/Coprinopsis%20pulchricaerulea | Coprinopsis pulchricaerulea is a species of mushroom-producing fungus in the family Psathyrellaceae.
Taxonomy
It was first described in 2022 by the mycologists Teresa Lebel, Tom May and Mahajabeen Padamsee and was classified as Coprinopsis pulchricaerulea based on genomics work done – which placed it close to Coprinopsis aesontiensis. Unlike C. aesontiensis, however, C. pulchricaerulea is blue.
Discovery
This species was first discovered by nature photographer Stephen Axford in 2012 growing in subtropical forests in northern New South Wales, Australia. Specimens were sent to the mycology team at the State Herbarium of South Australia where DNA analysis was performed. The species has been erroneously called Leratiomyces atrovirens, especially by many media sources covering the discovery. However the DNA results do not support this and Leratiomyces atrovirens has never been validly published.
Description
Coprinopsis pulchricaerulea is a small blue mushroom found rarely in Australia. It can appear to resemble a secotioid fungus due to the cap which may only partially open and the indistinct structure of the hymenium.
Cap: 8–28mm wide by 6–22mm tall. Starts spherical becoming ovate to convex with age. Pale or bright blue in colour discolouring with grey or green shades with age or when dry. Cap is fragile and covered in fine glistening white powdery warts which may wash off. Specimens collected in New Caledonia had fewer of these warts or were lacking them entirely. Gills: Start white or pale cream maturing to pale tan. Crowded. Stem: 5–20mm long and 3–7mm in diameter. Slightly bulbous base which tapers towards the cap. Has a stem ring towards the base. Spores: Ellipsoid to elongate without germ pore. Nondextrinoid.19–23 x 10–12.5 μm. Taste: Indistinct. Smell: Strong mushroom like smell.
Habitat and distribution
The specimens examined were found in a small areas of subtropical rainforest in New South Wales, New Caledonia and on Lord Howe Island in Australia. It grows solitary or in small groups in decaying leaf litter or wood in wet forests or rainforests.
Etymology
The specific epithet pulchricaerulea derives from the Latin pulcher meaning beautiful and caeruleus meaning blue, a reference to the spectacular blue colour of the mushrooms.
Similar species
DNA analysis shows that Coprinopsis aesontiensis is closely related. However this species has a grey cap as opposed to blue and is found in North Eastern Italy.
References
pulchricaerulea
Fungi described in 2022
Fungi of Australia
Fungi of New Caledonia
Fungus species | Coprinopsis pulchricaerulea | [
"Biology"
] | 582 | [
"Fungi",
"Fungus species"
] |
71,315,480 | https://en.wikipedia.org/wiki/Coprinopsis%20aesontiensis | Coprinopsis aesontiensis is a species of mushroom producing fungus in the family Psathyrellaceae.
Taxonomy
It was first described in 2016 by the Italian mycologists Andreas Melzer, Giuliano Ferisin & Francesco Dovana and classified as Coprinopsis aesontiensis based on DNA analysis.
Description
Coprinopsis aesontiensis is a small grey mushroom found rarely in North Eastern Italy.
Cap: Up to 30mm wide by 20mm tall. Campanulate (bell shaped) or conical. Grey with small white tufts or powdery scales. Gills: Start white maturing to dark brown. Crowded. Stem: 60-80mm long and 6-8mm in diameter. Slightly bulbous base. White with small hairs or downy tufts. Spores: Ellipsoid with a germ pore. 9.6-10.6 x 5-6 μm. Taste: Indistinct. Smell: Indistinct.
Habitat and distribution
The species was discovered in the North Eastern Friuli-Venezia Giulia region of Italy which borders Austria and Slovenia. Its distribution remains unclear.
Etymology
The specific epithet aesontiensis is named for the Aesontius river, a historical name for the Isonzo river in Slovenia.
Similar species
DNA analysis shows that Coprinopsis pulchricaerulea is closely related. However this species has a blue cap as opposed to grey and is found in the subtropical rainforests of Australia.
References
aesontiensis
Fungus species | Coprinopsis aesontiensis | [
"Biology"
] | 311 | [
"Fungi",
"Fungus species"
] |
71,316,163 | https://en.wikipedia.org/wiki/Coprinopsis%20martinii | Coprinopsis martinii is a species of mushroom producing fungus in the family Psathyrellaceae.
Taxonomy
It was first described in 1960 by the English mycologist Peter Darbishire Orton and classified as Coprinus martinii.
In 2001 phylogentic analysis restructured the Coprinus genus and it was reclassified as Coprinopsis martinii by the mycologists Scott Alan Redhead, Rytas J. Vilgalys & Jean-Marc Moncalvo.
Description
Coprinus martinii is a small inkcap mushroom which grows in wetland environments.
Cap: 0.5-2.2cm. Starts ovoid and expands to convex and then campanulate (bell shaped). Sometimes presenting as umbonate. Grey and covered in powdery fragments of the veil. Gills: Start white before turning black and deliquescing (dissolving into an ink-like black substance). Crowded. Stem: 3.2-6cm long and 1.5-2mm in diameter. Pale grey and tapering towards a slightly swollen base. Spore print: Black. Spores: Ellipsoid and smooth with a germ pore. 12.-16 x 6.5-8.5 μm. Taste: Indistinct. Smell: Indistinct.
Habitat and distribution
Grows trooping in small groups on rotting sedges and rushes belonging to the genera Carex, Scirpus and Juncus. Found in marshes and wetland environments spring through autumn. Widespread but seldom recorded.
References
martinii
Fungus species | Coprinopsis martinii | [
"Biology"
] | 321 | [
"Fungi",
"Fungus species"
] |
71,316,296 | https://en.wikipedia.org/wiki/Coprinopsis%20nivea | Coprinopsis nivea is a species of mushroom producing fungus in the family Psathyrellaceae. It is commonly known as the snowy inkcap.
Taxonomy
It was first described in 1801 by the German mycologist Christiaan Hendrik Persoon who classified it as Agaricus niveus.
In 1838 it was reclassified as Coprinus niveus by the Swedish mycologist Elias Magnus Fries.
In 2001 phylogentic analysis restructured the Coprinus genus and it was reclassified as Coprinopsis nivea by the mycologists Scott Alan Redhead, Rytas J. Vilgalys & Jean-Marc Moncalvo.
Description
Coprinopsis nivea is a small inkcap mushroom which grows in wetland environments.
Cap: 1.5–3 cm. Starts egg shaped expanding to become campanulate (bell shaped). Covered in white powdery fragments of the veil when young. Gills: Start white before turning grey and ultimately black and deliquescing (dissolving into an ink-like black substance). Crowded and adnate or free. Stem: 3–9 cm long and 4-7mm in diameter. White with a very slightly bulbous base which may present with white tufts similar to that of the cap. Spore print: Black. Spores: Flattened ellipsoid and smooth with a germ pore. 15-19 x 8.5-10.5 μm. Taste: Indistinct. Smell: Indistinct.
Etymology
The specific epithet nivea (originally niveus) is Latin for snowy or snow covered. This is a reference to the powdery white appearance of this mushroom.
Habitat and distribution
Grows in small trooping or tufting groups on old dung, especially that of cows and horses, Summer through late Autumn. Widespread and recorded quite regularly.
Similar species
Coprinopsis pseudonivea.
References
Psathyrellaceae
Coprinopsis
Fungus species | Coprinopsis nivea | [
"Biology"
] | 402 | [
"Fungi",
"Fungus species"
] |
72,817,650 | https://en.wikipedia.org/wiki/Rights%20of%20nature%20law | Rights of nature law is the codification and other implementations of the legal and jurisprudential theory of the rights of nature. This legal school of thought describes inherent rights as associated with ecosystems and species, similar to the concept of fundamental human rights.
The early 2000s saw a significant expansion of rights of nature law, in the form of constitutional provisions, treaty agreements, national and subnational statutes, local laws, and court decisions. As of 2022, nature's rights laws exist at the local to national levels in 39 countries, including in Canada, at least seven Tribal Nations in the U.S. and Canada, and over 60 cities and counties throughout the United States. The total number of initiatives was 409 as of June 2021 and 495 as of May 2024. The EcoJurisprudence Monitor lists over 540 as of early 2025.
Treaties
New Zealand
Legal standing for natural systems in New Zealand arose alongside new attention paid to long-ignored treaty agreements with the Indigenous Maori. In August 2012, a treaty agreement signed with the Maori iwi recognized the Whanganui River and tributaries as a legal entity, an "indivisible and living whole" with its own standing. The national Te Awa Tupua Act was enacted in March 2017 to further formalize this status.
In 2013, the Te Urewera Forest treaty agreement similarly recognized the legal personhood of the Forest, with the Te Urewera Act signed into law in 2014 to formalize this status. In 2017 a treaty settlement with the Maori was signed that recognized Mount Taranaki as "a legal personality, in its own right".
Each of these developments advanced the indigenous principle that the ecosystems are living, spiritual beings with intrinsic value, incapable of being owned in an absolute sense.
Constitutional law
Ecuador
In 2008, the people of Ecuador amended their Constitution to recognize the inherent rights of nature, or Pachamama. The new text arose in large part as a result of cosmologies of the indigenous rights movement and actions to protect the Amazon, consistent with the concept of sumak kawsay ("buen vivir" in Spanish, "good living" in English), or encapsulating a life in harmony with nature with humans as part of the ecosystem. Among other provisions, Article 71 states that "Nature or Pachamama, where life is reproduced and exists, has the right to exist, persist, maintain itself and regenerate its own vital cycles, structure, functions and its evolutionary processes." The Article adds enforcement language as well, stating that "Any person... may demand the observance of the rights of the natural environment before public bodies", and echoing Christopher Stone, Article 72 adds that “Nature has the right to be completely restored... independent of the obligation... to compensate people”.
Judicial decisions
Bangladesh
In 2019, the High Court of Bangladesh ruled on a case addressing pollution of and illegal development along the Turag River, an upper tributary of the Buriganga.
Among its findings, the high court recognized the river as a living entity with legal rights, and it further held that the same would apply to all rivers in Bangladesh. The court ordered the National River Protection Commission to serve as the guardian for the Turag and other rivers.
Colombia
Colombia has not adopted statutes or constitutional provisions addressing nature's rights (as of 2019). However, this has not prevented Colombian courts from finding nature's rights as inherent. In a 2016 case, the Colombia Constitutional Court ordered cleanup of the polluted Atrato River, stating that nature is a "true subject of rights that must be recognized by states and exercised... for example, by the communities that inhabit it or have a special relationship with it”. The court added that humans are “only one more event within a long evolutionary chain [and] in no way... owner of other species, biodiversity or natural resources, or the fate of the planet".
In 2018, the Colombia Supreme Court took up a climate change case by a group of children and young adults that also raised fundamental rights issues. In addition to making legal findings related to human rights, the court found that the Colombian Amazon is a "'subject of rights', entitled to protection, conservation, maintenance and restoration". It recognized the special role of Amazon deforestation in creating greenhouse gas emissions in Colombia, and as a remedy ordered the nation and its administrative agencies to ensure a halt to all deforestation by 2020. The court further allocated enforcement power to the plaintiffs and affected communities, requiring the agencies to report to the communities and empowering them to inform the court if the agencies were not meeting their deforestation targets.
Ecuador
A significant body of case law has been expanding in Ecuador to implement the nation's constitutional provisions regarding the rights of nature. Examples include lawsuits in the areas of biodigestor pollution, impaired flow in the Vilcabamba River, and hydropower.
Germany
In August 2024, the Regional Court (Landgericht) of Erfurt became the first German court to recognize rights of Nature under the EU Charter of Fundamental Rights in an important decision.
India
As in Colombia, as of 2019 no statutes or constitutional provisions in India specifically identified rights of nature. Nevertheless, the India Supreme Court in 2012 set the stage for cases to come before it on rights of nature, finding that "Environmental justice could be achieved only if we drift away from the principle of anthropocentric to ecocentric... humans are part of nature and non-human has intrinsic value."
The Uttarakhand High Court applied the principle of ecocentric law in 2017, recognizing the legal personhood of the Ganga and Yamuna rivers and ecosystems, and calling them "living human entities" and juridical and moral persons. The court quickly followed with similar judgments for the glaciers associated with the rivers, including the Gangotri and Yamunotri, and other natural systems. While the India Supreme Court stayed the Ganga and Yamuna judgment at the request of local authorities, those authorities supported the proposed legal status in concept, but were seeking "implementation guidance".
Peru
The Marañón River, one of the Amazon's largest tributaries, recognized as a legal entity with inherent rights. The Nauta court in Loreto has ruled that what is one of the country's most important rivers and water sources must now be considered a subject with real rights.
This decision was initiated by the Kukama indigenous community of Shapajilla, Loreto, led by women and supported by the Legal Defense Institute.
National, sub-national, and local law
Canada
Quebec
On February 23, 2021, the Alliance for the Protection of the Magpie/Muteshekau Shipu River (in Innu), in partnership with the International Observatory on Nature’s Rights, announced the recognition of legal personhood of the Magpie River.
The Magpie River is located in Nitassinan (ancestral territory of the Innu people), in eastern Quebec. Its Innu name, Muteshekau Shipu, means “the river where the water passes between square rocky cliffs”.
Bolivia
Following adoption of nature's rights language in its 2009 Constitution, in 2010 Bolivia's Legislature passed the Law of the Rights of Mother Earth, Act No. 071. Bolivia followed this broad outline of nature's rights with the 2012 Law of Mother Earth and Integral Development for Living Well, Act. No. 300, which provided some implementation details consistent with nature's rights. It states in part that the "violation of the rights of Mother Earth, as part of comprehensive development for Living Well, is a violation of public law and the collective and individual rights". While a step forward, this enforcement piece has not yet risen to the level of a specific enforcement mechanism.
Mexico
State, regional, and local laws and local constitutional provisions have been arising in Mexico, including adoption in the constitutions of the Mexican states of Colima and Guerrero, and that of Mexico City.
Spain
On September 30, 2022, Parliament passed Law 19/2022, recognizing the legal personhood of the Mar Menor and its basin, thus becoming the first ecosystem in Europe with its own rights
On March 31, 2023 the regulation concerning the application of the law on the legal personality of the Mar Menor was published for public comment.
Uganda
Part 1, Section 4 of Uganda's 2019 National Environment Act addresses the Rights of Nature, stating in part that "Nature has the right to exist, persist, maintain and regenerate its vital cycles, structure, functions and its processes in evolution." Advocates who had sought inclusion of such language observed that "Ugandans' right to a healthy environment cannot be realised unless the health of Nature herself is protected," and that the language adoption reflected "recent gains for the growing African movement for Earth Jurisprudence".
United States
At the local level dozens of ordinances with rights of nature provisions have been passed as of 2019 throughout the United States, and in tribal lands located within the U.S. boundaries. Most were passed in reaction to a specific threat to local well-being, such as threats posed by hydrofracking, groundwater extraction, gravel mining, and fossil fuel extraction. For example, Pittsburgh, Pennsylvania passed an anti-fracking law that included the following provision to buttress protections: "Natural communities and ecosystems... possess inalienable and fundamental rights to exist and flourish." The ordinance continues that "Residents... shall possess legal standing to enforce those rights."
California
Residents in Santa Monica, California proactively sought to recognize nature's rights in local law after the U.S. Supreme Court's expansion of corporate rights in Citizens United v. FEC. In 2013 the Santa Monica City Council adopted a "Sustainability Rights Ordinance", recognizing the "fundamental and inalienable rights" of "natural communities and ecosystems" in the city to "exist and flourish". The ordinance emphasized that "[c]orporate entities... do not enjoy special privileges or powers under the law that subordinate the community's rights to their private interests". It specifically defined "natural communities and ecosystems" to include "groundwater aquifers, atmospheric systems, marine waters, and native species". Santa Monica updated its Sustainable City Plan in 2014 to reinforce its codified commitment to nature's rights. In 2018, the city council adopted a Sustainable Groundwater Management Ordinance that specifically referenced the inherent rights of the local aquifer to flourish.
Florida
In November, 2020, voters in Orange County, Florida passed a charter amendment for the "right to clean water" by a margin of 89% that protects waterways in the county from pollution and enables citizens to bring lawsuits to defend against such pollution, becoming the largest community in the country to enact such a rights of nature initiative. It has prompted the Florida Right To Clean Water direct initiative to incorporate the principle into the state constitution, which is gathering petition signatures to have an amendment put onto the 2024 ballot for consideration by all Florida voters. In his January 2022 monthly newsletter, Jim Hightower identified the Florida initiative as, "the epicenter of today’s Rights of Nature political movement".
Ohio
During a special election in February, 2019, voters in Toledo, Ohio passed the "Lake Erie Bill of Rights" (LEBOR). The law was struck down by the Supreme Court of Ohio in 2020. BP North America spent almost $300,000 fighting the bill through a front group.
Tribal laws
Ho-Chunk Nation of Wisconsin
In 2015 the Ho-Chunk Nation of Wisconsin passed a resolution amending their constitution to include the rights of nature. By 2020 a working group was determining how to integrate the resolution into their constitution, laws, regulations, and processes.
Ponca
In 2017, the Ponca Nation enacted a rights of nature law which is a resolution that gives the Ponca Tribal Court the power to punish crimes against nature with prison and fines.
International bodies and soft law
United Nations
Advancements during the early twenty-first century in international "soft law" (quasi-legal instruments generally without legally binding force) have precipitated broader discussions about the potential for integrating nature's rights into legal systems. The United Nations has held nine "Harmony with Nature" General Assembly Dialogues as of 2019 on Earth-centered governance systems and philosophies, including discussions of rights of nature specifically. The companion United Nations Harmony with Nature initiative compiles rights of nature laws globally and offers a U.N. "Knowledge Network" of Earth Jurisprudence practitioners across disciplines. These U.N. Dialogues and the Harmony with Nature initiative may provide a foundation for development of a United Nations-adopted Universal Declaration of the Rights of Nature which, like the U.N.'s Universal Declaration of Human Rights, could form the foundation for rights-based laws worldwide. A model could be the 2010 UDRME, an informal, but widely-supported nature's rights agreement based on the UDHR.
International Union for Conservation of Nature
In 2012, the International Union for Conservation of Nature (IUCN, the only international observer organization to the U.N. General Assembly with expertise in the environment) adopted a resolution specifically calling for a Universal Declaration of the Rights of Nature. The IUCN reaffirmed its commitment to nature's rights at its next meeting in 2016, where the body voted to build rights of nature implementation into the upcoming, four-year IUCN Workplan. The IUCN's subgroup of legal experts, the World Commission on Environmental Law, later issued an "IUCN World Declaration on the Environmental Rule of Law" recognizing that "Nature has the inherent right to exist, thrive, and evolve".
Ongoing initiatives
Canada
Quebec
Since its creation in 2018, the International Observatory on Nature's Rights has been working for the recognition of the legal personality of the St. Lawrence River, one of Quebec's true jewels.
On May 5, 2022, a bill was jointly tabled in the House of Commons and the Quebec National Assembly to recognize the legal personality and rights of the St. Lawrence River, but was never passed.
On April 19, 2023, the Assembly of First Nations Quebec-Labrador recognizes the Legal Personhood of the Saint Lawrence River.
Following recognition of its legal personality by the First Nations, the St. Lawrence River is now waiting to be recognized by the Quebec government.
Ontario
Although it flows primarily through Quebec, the St. Lawrence River also has a portion in Ontario, where it serves as a natural boundary between that province and New York State in the United States.
Since its launch in November 2023, the Ontario Chapter of the International Observatory for the Rights of Nature has been working for the recognition of the St. Lawrence River in Ontario.
France
On July 29, 2021, a coalition of peoples including Tavignany Vivu, UMANI and Terre de Liens Corsica-Terra di u Cumunu launched a Declaration of the Rights of the Tavignanu River. This declaration, a first for France, is supported by citizens, local authorities and members of the European Parliament and aims to win support for a local referendum on the status of the Tavignanu River.
Initiated by POLAU in 2019, the Parliament of the Loire approach aims to recognize the rights of the Loire river.
For many years, a number of associations such as Les Gardien.ne.s de la Seine have been campaigning for recognition of the Seine's rights.
Switzerland
In 2020, the ID-EAU organization launched an initiative to give the Rhône a legal personhood.
Notable documents
Early legislation, treates, case law
Germany (2024). Erfurt Regional Court (8th Civil Chamber), judgment of 02.08.2024 - 8 O1373/21
Quebec (2021). Mirror resolutions of the Ekuanitshit Innu Council and the Minganie Regional County Municipality (MRC).
(First constitutional provisions recognizing nature's rights)
(Early national law recognizing nature's rights)
(Stating that the contaminated Atrato River is a “true subject of rights”)
(Recognition of the inherent rights of the Colombian Amazon to a healthy climate)
(Constitutional law case calling for a shift from anthropocentric to ecocentric principles of justice)
(Court decision recognizing the legal personhood of the Ganga and Yamuna rivers in India)
(Court decision recognizing the legal personhood of glaciers and associated natural systems in India)
(First national law recognizing a river as a legal person)
(National law recognizing a former national park as a legal person)
(First national law in Africa recognizing nature's rights)
(Constitutional provision recognizing “ecosystems and species as a collective entity subject of rights” in one of the world's largest cities)
(Largest U.S. city to recognize nature's rights in law, as of 2019)
(First local law on the U.S. West Coast recognizing nature's rights)
Other notable documents
(First worldwide declaration of nature's rights; modeled on Universal Declaration of Human Rights)
(Call for a Universal Declaration of the Rights of Nature by international experts organization that holds both observer and consultative status at the United Nations)
(Statement by IUCN legal experts recognizing that “Nature has the inherent right to exist, thrive, and evolve”)
Declaration of the Rights of the Moon (2021)
See also
Animal rights
Common heritage of humanity
Deep ecology (an environmental philosophy promoting the inherent worth of living beings regardless of their instrumental utility to human needs)
Earth jurisprudence
Ecocide (attempts to criminalize human activities that cause extensive damage to ecosystems)
Environmental personhood
Sumak kawsay (Buen Vivir, or "good living", rooted in the worldview of the Quechua peoples of the Andes)
Wild law (human laws that are consistent with Earth jurisprudence)
References
Further reading
Rights of nature | Rights of nature law | [
"Environmental_science"
] | 3,622 | [
"Environmental personhood",
"Environmental ethics"
] |
72,818,594 | https://en.wikipedia.org/wiki/HR%201099 | HR 1099 is a triple star system in the equatorial constellation of Taurus, positioned to the north of the star 10 Tauri. This system has the variable star designation V711 Tauri, while HR 1099 is the star's identifier from the Bright Star Catalogue. It ranges in brightness from a combined apparent visual magnitude of 5.71 down to 5.94, which is bright enough to be dimly visible to the naked eye. The distance to this system is 96.6 light years based on parallax measurements, but it is drifting closer with a radial velocity of about −15 km/s.
This system was discovered to be a double star by F. G. W. Struve in 1822, with the components A and B having an angular separation of . (The separation was measured at in 2016.) R. E. Wilson in 1953 determined that the brighter member of this pair, component A, has a variable radial velocity. In 1963, O. C. Wilson noted that the same component shows very high emission cores in the calcium H and K absorption lines. Follow-up observations by O. C. Wilson in 1964 showed that the hydrogen–α line of component A is fully in emission and it displays moderate broadening due to rotation. He found a stellar classification of K3 V for component B, matching an ordinary K-type main-sequence star.
Observations during 1974–1975 demonstrated that component A is a spectroscopic binary star system of the RS Canum Venaticorum variable class. Given its average magnitude of around 5.9, it is one of the brighter known variables of this type. No eclipses were observed, but an orbital period of 2.838 days was determined. Most of the emission was found to be coming from the more massive member of this pair. Radio emission from the binary was detected by F. N. Owen in 1976. It was shown to be a soft X-ray source in 1978 using the HEAO 1 satellite.
This double-lined spectroscopic binary system consists of an evolving K-type subgiant and an ordinary G-type main sequence star. The two stars are orbiting so close to each other that their tidal effects are giving them an elliptical shape. The subgiant is filling about 80% of its Roche lobe. The chromosphere of the subgiant is one of the most active known, with a deep convective zone powering the magnetic dynamo. The G-type companion has a shallow convection zone and is less active.
In 1980, significant variations were found in some spectral features related to surface temperature, suggesting the presence of starspots. Doppler imaging confirmed these starspots are associated with the K subgiant. (It was the first cool star to have its surface Doppler imaged.) The evidence suggests that the spots first appear at low latitude then migrated toward the poles. These spots are much larger than they are on the Sun. About 70% of all spots have been observed at latitudes higher than 50°, particularly around the polar region. A polar spot has persisted for at least twenty years.
The baseline apparent magnitudes of the two stars, after subtracting the effects of starspots, is 5.80 and 7.20. Long term monitoring indicates the subgiant has two activity cycles, similar to the 11-year solar cycle. A cycle is associated with symmetrical flip-flopping of the spotted area between hemispheres. The longer 15–16 year cycle is a periodic variation in the total spot area. The global magnetic field of the star may be precessing with respect to the axis of rotation.
See also
UX Arietis
References
Further reading
G-type main-sequence stars
K-type main-sequence stars
K-type subgiants
RS Canum Venaticorum variables
Triple star systems
Taurus (constellation)
1099
BD+00 0616
022468
016852
Tauri, V711 | HR 1099 | [
"Astronomy"
] | 815 | [
"Taurus (constellation)",
"Constellations"
] |
72,818,708 | https://en.wikipedia.org/wiki/12%20Cassiopeiae | 12 Cassiopeiae (12 Cas) is a white giant in the constellation Cassiopeia, about 860 light years away. It has an apparent magnitude of 5.4, so it faintly visible to the naked eye.
The spectrum of 12 Cassiopeiae is classified as a B9-type giant. About three times as massive as the Sun and 386 times as luminous, it has expanded away from the main sequence after exhausting its core hydrogen. It now has a radius of with an effective temperature of about , leading to a bolometric luminosity of .
References
Cassiopeia (constellation)
Cassiopeiae, 12
0093
002011
001960
BD+61 0069
B-type giants | 12 Cassiopeiae | [
"Astronomy"
] | 156 | [
"Cassiopeia (constellation)",
"Constellations"
] |
72,818,791 | https://en.wikipedia.org/wiki/Divina%20Frau-Meigs | Divina Frau-Meigs (born 9 June 1959) is a Moroccan-born sociologist of media and professor at the Sorbonne Nouvelle University Paris III (Paris III) in France where her areas of research include, cultural diversity, dynamic identities, human/children's rights, internet governance, media education, media matrices, media in English-speaking countries, and risky content. Her research has also included media content and risk behaviors, the reception and use of Information and communications technology, and American studies. She is the chair of "Savoir-devenir in sustainable digital development" for UNESCO and coordinator of "TRANSLIT" for the Agence nationale de la recherche.
Early life and education
Divina Frau-Meigs was born in Casablanca, Morocco, on 9 June 1959, to Spanish parents.
She graduated from the École normale supérieure de lettres et sciences humaines (English, 1980) and received her master's degree from Stanford University (Education and Communication, 1984). She then taught English at Sorbonne Paris North University (1985-1988), before returning to the U.S. to obtain a second master's degree from the Annenberg School for Communication at the University of Pennsylvania (Communication, 1991). In the 1980s, Frau-Meigs was a recipient of a Fulbright (1983-84), Ministry of Higher Education (1984-85), and "Lavoisier" (1988-189) scholarships.
Back in France, she taught high school (Aubervilliers, La Courneuve; 1991-1993) and completed a doctorate in 1993 in information and communication sciences at Paris-Panthéon-Assas University, writing a dissertation under the direction of Josette Poinssac on (International television flows: figures, analog systems and cultural transfers. A comparative analysis of the contents of television programs in nine countries of the world and the role of the USA in the production of these contents).
Career and research
In 1993, Frau-Meigs was elected Associate Professor at Paris III. In 1999, she obtained her habilitation to direct research at the Paris III with a dissertation entitled, (From television to screen subcultures: representation in all its states, in the United States). In 1999, she was promoted to professor at the University of Orléans, before returning to Paris III in 2004. In 2006, she held the information-communication chair at the Autonomous University of Barcelona, giving a doctoral course on cultural diversity in globalization.
Frau-Meigs is a specialist in media, content, and risky behaviors (violence, pornography, information, media panics) as well as in questions of reception and use of information and communication technologies (acculturation, education, regulation). She directs a research center, the "Center for Research on the English-Speaking World" (CREW, ÉA 4399) in Paris III. She also directs a professional master's degree entitled "Computer Applications: Management, Studies, Multimedia, eLearning" (AIGÉME) at the same university, with a double specialization: "Distance Learning Engineering" and "Media Literacy Engineering" (face-to-face and distance learning courses).
The author of more than 300 articles and approximately 30 books, Frau-Meigs has published on issues of cultural diversity and acculturation, as well as on e-learning, digital identity, and internet governance. Her collaborative works have included (The screens of violence) (with Sophie Jehel, published by Economica) and (Media and technology: the American example) (with Francis Bordat and John Dean, published by Ellipses). She has served as co-editor of (French journal of American studies). She has served as vice-president for international relations of the French Society for Information and Communication Sciences (1993-96) and vice-president of the International Association for Information and Communication Studies and Research (IAMCR) (2002-08). In 2000, she was a founding member of the European Consortium for Communications Research (ECCR). Frau-Meigs is a member of the Scientific Council of the Inter-Associative Collective "Enfance-Médias" (CIEM) (2003-). She sits on the board of the European Communication Research and Education Association (ECREA) (2008-).
Awards and honours
2006, E-Toile d'Or Civil Society Award, AUTRANS 2006, Grenoble
2016, Global Media and Information Literacy (MIL) Award
Selected works
Écrans de la violence, Economica, 1997 (with Sophie Jehel)
Médias et technologies : l’exemple des États-Unis, Ellipses, collection "Universités : anglais", 2001
Médiamorphoses américaines, Economica, 2001 (with Francis Bordat and John Dean)
Dossier de l’audiovisuel, number 108 "Les programmes jeunesse : réenchanter la télévision", March-April 2003 (director)
Jeunes, médias, violences, Economica, 2003 (public version of the report of the Interassociative Collective "Childhood and Media" - CIEM, Environnement médiatique : que transmettons-nous à nos enfants) (with Sophie Jehel)
Qui a détourné le 11 septembre ? Journalisme, information et démocratie aux États-Unis, Ina-de Boeck, collection "Médias recherches", 2006
Kit pour l’éducation aux médias à l’usage des enseignants, des parents et des professionnels, Unesco, 2007 (pdf) (director)
Mapping Media Education Policies in the World: Visions, Programmes and Challenges, Unesco, Alliance des civilisations, 2009 (pdf) (with Jordi Torrent)
Médias et cognition sociale : dépasser les paniques médiatiques, Érès, 2010
Media Matters in the cultural contradictions of the information society. Towards a human rights-based governance, Presses du Conseil de l’Europe, 2010
Penser la société de l'écran : dispositifs et usages, Presses Sorbonne nouvelle, collection "Les fondamentaux de la Sorbonne nouvelle", 2011
Socialisation des jeunes et éducation aux médias : du bon usage des contenus et comportements à risque, Érès, collection "Éducation et société", 2011
Faut-il avoir peur des fake news ?, Documentation française, 2019
References
External links
Personal website
1959 births
Living people
People from Casablanca
Moroccan academics
Information and communications technology
École Normale Supérieure alumni
Stanford University alumni
Annenberg School for Communication at the University of Pennsylvania alumni | Divina Frau-Meigs | [
"Technology"
] | 1,387 | [
"Information and communications technology"
] |
72,819,874 | https://en.wikipedia.org/wiki/List%20of%20basal%20eudicot%20families | The basal eudicots are a group of 13 related families of flowering plants in four orders: Buxales, Proteales, Ranunculales and Trochodendrales. Like the core eudicots (the rest of the eudicots), they have pollen grains with three colpi (grooves) or other derived structures, and usually have flowers with four or five petals (sometimes multiples of four or five, sometimes reduced or fused). Unlike other eudicots, they sometimes have flowers with petals in twos or multiples of two.
The basal eudicots include trees, shrubs, woody vines and herbaceous plants. Cultivars of Buxus are used for hedges and topiary, and the high-quality wood is commonly used for decorative carvings and musical instruments. The sacred lotus is the national flower of India and Vietnam, and the waratah is the floral emblem of the Australian state of New South Wales. The opium poppy, Papaver somniferum, a source of morphine, was cultivated thousands of years ago in Mesopotamia. Macadamia nuts are mainly grown in Hawaii and Australia.
The orders Dilleniales and Gunnerales are within the core eudicots. Species of Gunnerales often have serrate (serrated) leaves, with flowers similar to those of Buxales. The epidermis and hairs on species of Dilleniales are often full of silica.
Glossary
From the glossary of botanical terms:
annual: a plant species that completes its life cycle within a single year or growing season
basal: attached close to the base (of a plant or an evolutionary tree diagram)
climber: a vine that leans on, twines around or clings to other plants for vertical support
deciduous: shedding or falling seasonally, as with bark, leaves, or petals
glandular hair: a hair tipped with a secretory structure
herbaceous: not woody; usually green and soft in texture
perennial: lives for more than two years
unisexual: bearing only male or only female reproductive organs (i.e. not bisexual)
woody: hard and lignified; not herbaceous
The APG IV system is the fourth in a series of plant taxonomies from the Angiosperm Phylogeny Group.
Dilleniales and Gunnerales families
Basal eudicot families
See also
List of plant family names with etymologies
Notes
Citations
References
See the Creative Commons license.
See their terms-of-use license.
Systematic
Basal eudicot
Basal eudicot families
basal eudicot families
Eudicots | List of basal eudicot families | [
"Biology"
] | 529 | [
"Lists of biota",
"Lists of plants",
"Plants"
] |
72,819,916 | https://en.wikipedia.org/wiki/Omar%20Khayyam%20%281923%20film%29 | Omar Khayam is an American silent movie. It was widely distributed in Australia in 1923, where it was praised for its imaginative technical effects. It bears many similarities to the lost film A Lover's Oath, which was made in 1921 but not released until 1925.
Plot
The story, through which many images of Persian life and thought are interspersed, concerns three boyhood friends, Omar, Nizam and Hassan, who made a solemn pact that whichever became successful would share his good fortune with the others.
Nizam grew to become ruler of the country, and assisted Omar in his studies. Hassan became a scheming scoundrel whose lusting after the beautiful Shirin was cut short by his clever wife.
The film concludes with the lovers "beneath the boughs".
The film includes many scenes relating to verses from the Rubaiyat of Omar Khayyam, including the market places, the Sultan and his courtiers, the muezzin calling the faithful to prayer, the crowd clamoring at the tavern door, the potter molding his wet clay, gardens ablaze with roses, ruined temples and palaces, Heaven and Hell. Images of astronomical phenomena were especially praised. The film opened at Hoyts' cinemas in Sydney ("Australia" and "Apollo" theatres) on 17 February and Melbourne ("De Luxe") on 24 February 1923.
Cast
Frederick Warde as Omar
Edwin Stevens as Hassan
Paul Weigel as Sheik Rustan
B. Post (perhaps Guy Bates Post) as the Vizier
Kathleen Key as Shirin, daughter of the Sheik
Ramon Novarro (often cited as Raymond Navarro) as her lover
"and a cast of over 7,000 people"
Director was Ferdinand P. Earle, jun.
The film was presented throughout Australia by E. R. Chambers and E. O. Gurney of "Selected Super Films (Australasia Ltd)". Gurney has elsewhere been mentioned as an Australian film director who, like John Farrow, left for Hollywood.
The film was then taken to Hobart's Strand theatre and to Adelaide, where it was shown at the Town Hall and hailed as a "masterpiece" and the "last word in artistic achievement of motion picture history".
It went on to regional Victoria and New South Wales, where it was universally well received — "the picture magnificent, which no-one should miss"
It reached Perth in September.
Omar the Tentmaker
Richard Walton Tully's play Omar the Tentmaker, depicting illicit love in the harems, was in 1921 made into a film, directed by its author, and starring Virginia Brown Faire and Guy Bates Post. It was shown in Australia around the same time as Omar Khayyam. Australian publicity for the film referenced FitzGerald's Rubaiyat, though descriptions of the film seem remote from the poetry, or the life, of the historic Omar Khayyam, who despite his surname (which means "tentmaker"), was a renowned astronomer and mathematician.
Notes
References
1923 films
1923 lost films
1920s American films
American silent feature films
Lost American films
Cultural depictions of Omar Khayyam | Omar Khayyam (1923 film) | [
"Astronomy"
] | 628 | [
"Cultural depictions of Omar Khayyam",
"Cultural depictions of astronomers"
] |
72,822,609 | https://en.wikipedia.org/wiki/HD%20133880 | HD 133880, also known as HR 5624 and HR Lupi, is a Bp star about 340 light years from the Earth, in the constellation Lupus. It is a 5th magnitude star, and will be faintly visible to the naked eye of an observer far from city lights. It is an SX Arietis variable star, varying from magnitude 5.76 to 5.81 over a period of 21.0594 hours. HD 133880 is a member of the Upper Centaurus–Lupus association. It is a young star, estimated to have completed only percent of its projected main sequence lifetime. It is one of the few stars known to produce coherent pulsed radio radiation via electron cyclotron maser emission.
The spectrum of HD 133880 matches a B8 subgiant, but with unusually strong absorption lines of some metals, making it a member of the chemically peculiar Ap/Bp star class. For this particular star, silicon lines at are notably strong. Its rotation rate is unusually fast for a star of this type.
In 1985, Christoffel Waelkens found that HD 133880 is a variable star with a period of days, varying by 0.15, 0.10 and 0.06 magnitudes in the U, B and V bands respectively. In 1986, the star was given the variable star designation HR Lupi. Later measurements of the period varied significantly, and can only be reconciled if the period varies in time.
In 1990, John Landstreet found that HD 133880 has a very strong (several kG) magnetic field, with the unusual property that its quadrupole term is stronger than the dipole term. However a study in 2017 found the magnetic field was better described as a distorted asymmetric dipole, with a maximum strength of 12 kG, and an average strength of 4 kG.
Much of the research interest in HD 133880 arises from its radio emissions. Jeremy Lim et al. observed the star with the Australia Telescope Compact Array in 1995, and found that because the star's magnetic and rotation axes are not aligned, the 6 cm wavelength radiation they measured showed variation in both strength and polarization as the star rotated. In 2018 Barnali Das et al. detected electron cyclotron maser emission from the star at 610 MHz, using the GMRT. HD 133880 was the second star found to radiate in this way (after CU Virginis). The radiation was found to vary by an order of magnitude as the star rotated, and had roughly 100 percent right circular polarization when the emission peaked.
References
SX Arietis variables
Lupus (constellation)
74066
133880
Lupi, HR
5624
B-type subgiants
Ap stars | HD 133880 | [
"Astronomy"
] | 564 | [
"Constellations",
"Lupus (constellation)"
] |
72,824,417 | https://en.wikipedia.org/wiki/Silver%20laurate | Silver laurate is an inorganic compound, a salt of silver and lauric acid with the formula , colorless (white) crystals.
Physical properties
Silver laurate forms colorless (white) crystals of triclinic crystal system, cell parameters:
a = 0.5517 nm, b = 3.435 nm, c = 0.4097 nm, α = 91.18°, β = 124.45°, γ = 92.90°, Z = 2.
It does not dissolve in ethanol or in diethyl ether.
References
External links
Colloidal Silver Information
Laurates
Silver compounds | Silver laurate | [
"Chemistry"
] | 125 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
72,824,901 | https://en.wikipedia.org/wiki/Gauss%20composition%20law | In mathematics, in number theory, Gauss composition law is a rule, invented by Carl Friedrich Gauss, for performing a binary operation on integral binary quadratic forms (IBQFs). Gauss presented this rule in his Disquisitiones Arithmeticae, a textbook on number theory published in 1801, in Articles 234 - 244. Gauss composition law is one of the deepest results in the theory of IBQFs and Gauss's formulation of the law and the proofs its properties as given by Gauss are generally considered highly complicated and very difficult. Several later mathematicians have simplified the formulation of the composition law and have presented it in a format suitable for numerical computations. The concept has also found generalisations in several directions.
Integral binary quadratic forms
An expression of the form , where are all integers, is called an integral binary quadratic form (IBQF). The form is called a primitive IBQF if are relatively prime. The quantity is called the discriminant of the IBQF . An integer is the discriminant of some IBQF if and only if . is called a fundamental discriminant if and only if one of the following statements holds
and is square-free,
where and is square-free.
If and then is said to be positive definite; if and then is said to be negative definite; if then is said to be indefinite.
Equivalence of IBQFs
Two IBQFs and are said to be equivalent (or, properly equivalent) if there exist integers α, β, γ, δ such that
and
The notation is used to denote the fact that the two forms are equivalent. The relation "" is an equivalence relation in the set of all IBQFs. The equivalence class to which the IBQF belongs is denoted by .
Two IBQFs and are said to be improperly equivalent if
and
The relation in the set of IBQFs of being improperly equivalent is also an equivalence relation.
It can be easily seen that equivalent IBQFs (properly or improperly) have the same discriminant.
Gauss's formulation of the composition law
Historical context
The following identity, called Brahmagupta identity, was known to the Indian mathematician Brahmagupta (598–668) who used it to calculate successively better fractional approximations to square roots of positive integers:
Writing this identity can be put in the form
where .
Gauss's composition law of IBQFs generalises this identity to an identity of the form where are all IBQFs and are linear combinations of the products .
The composition law of IBQFs
Consider the following IBQFs:
If it is possible to find integers and such that the following six numbers
have no common divisors other than ±1, and such that if we let
the following relation is identically satisfied
,
then the form is said to be a composite of the forms and . It may be noted that the composite of two IBQFs, if it exists, is not unique.
Example
Consider the following binary quadratic forms:
Let
We have
.
These six numbers have no common divisors other than ±1.
Let
,
.
Then it can be verified that
.
Hence is a composite of and .
An algorithm to find the composite of two IBQFs
The following algorithm can be used to compute the composite of two IBQFs.
Algorithm
Given the following IBQFs having the same discriminant :
Compute
Compute
Compute such that
Compute
Compute
Compute
Compute
Compute
Then so that is a composite of and .
Properties of the composition law
Existence of the composite
The composite of two IBQFs exists if and only if they have the same discriminant.
Equivalent forms and the composition law
Let be IBQFs and let there be the following equivalences:
If is a composite of and , and is a composite of and , then
A binary operation
Let be a fixed integer and consider set of all possible primitive IBQFs of discriminant . Let be the set of equivalence classes in this set under the equivalence relation "". Let and be two elements of . Let be a composite of the IBQFs and in . Then the following equation
defines a well-defined binary operation "" in .
The group GD
The set is a finite abelian group under the binary operation .
The identity element in the group =
The inverse of in is .
Modern approach to the composition law
The following sketch of the modern approach to the composition law of IBQFs is based on a monograph by Duncan A. Buell. The book may be consulted for further details and for proofs of all the statements made hereunder.
Quadratic algebraic numbers and integers
Let be the set of integers. Hereafter, in this section, elements of will be referred as rational integers to distinguish them from algebraic integers to be defined below.
A complex number is called a quadratic algebraic number if it satisfies an equation of the form
where .
is called a quadratic algebraic integer if it satisfies an equation of the form
where
The quadratic algebraic numbers are numbers of the form
where and has no square factors other than .
The integer is called the radicand of the algebraic integer . The norm of the quadratic algebraic number is defined as
.
Let be the field of rational numbers. The smallest field containing and a quadratic algebraic number is the quadratic field containing and is denoted by . This field can be shown to be
The discriminant of the field is defined by
Let be a rational integer without square factors (except 1). The set of quadratic algebraic integers of radicand is denoted by . This set is given by
is a ring under ordinary addition and multiplication. If we let
then
.
Ideals in quadratic fields
Let be an ideal in the ring of integers ; that is, let be a nonempty subset of such that for any and any , . (An ideal as defined here is sometimes referred to as an integral ideal to distinguish from fractional ideal to be defined below.) If is an ideal in then one can find such any element in can be uniquely represented in the form with . Such a pair of elements in is called a basis of the ideal . This is indicated by writing . The norm of is defined as
.
The norm is independent of the choice of the basis.
Some special ideals
The product of two ideals and , denoted by , is the ideal generated by the -linear combinations of .
A fractional ideal is a subset of the quadratic field for which the following two properties hold:
For any and for any , .
There exists a fixed algebraic integer such that for every , .
An ideal is called a principal ideal if there exists an algebraic integer such that . This principal ideal is denoted by .
There is this important result: "Given any ideal (integral or fractional) , there exists an integral ideal such that the product ideal is a principal ideal."
An equivalence relation in the set of ideals
Two (integral or fractional) ideals and ares said to be equivalent, dented , if there is a principal ideal such that . These ideals are narrowly equivalent if the norm of is positive. The relation, in the set of ideals, of being equivalent or narrowly equivalent as defined here is indeed an equivalence relation.
The equivalence classes (respectively, narrow equivalence classes) of fractional ideals of a ring of quadratic algebraic integers form an abelian group under multiplication of ideals. The identity of the group is the class of all principal ideals (respectively, the class of all principal ideals with ). The groups of classes of ideals and of narrow classes of ideals are called the class group and the narrow class group of the .
Binary quadratic forms and classes of ideals
The main result that connects the IBQFs and classes of ideals can now be stated as follows:
"The group of classes of binary quadratic forms of discriminant is isomorphic to the narrow class group of the quadratic number field ."
Bhargava's approach to the composition law
Manjul Bhargava, a Canadian-American Fields Medal winning mathematician introduced a configuration, called a Bhargava cube, of eight integers (see figure) to study the composition laws of binary quadratic forms and other such forms. Defining matrices associated with the opposite faces of this cube as given below
,
Bhargava constructed three IBQFs as follows:
Bhargava established the following result connecting a Bhargava cube with the Gauss composition law:
"If a cube A gives rise to three primitive binary quadratic forms Q1, Q2, Q3, then Q1, Q2, Q3 have the same discriminant, and the product of these three forms is the identity in the group defined by Gauss composition. Conversely, if Q1, Q2, Q3 are any three primitive binary quadratic forms of the same discriminant whose product is the identity under Gauss composition, then there exists a cube A yielding Q1, Q2, Q3."
References
Carl Friedrich Gauss
Quadratic forms
Number theory | Gauss composition law | [
"Mathematics"
] | 1,846 | [
"Discrete mathematics",
"Quadratic forms",
"Number theory"
] |
72,825,536 | https://en.wikipedia.org/wiki/Lead%28II%29%20laurate | Lead(II) laurate is an metal-organic compound with the chemical formula . It is classified as a metallic soap, i.e. a metal derivative of a fatty acid. Like most soaps, it does not dissolve in water. Lead soaps have been used as stabilizers and plasticizers in PVC.
Preparation
Lead soaps are usually prepared by combining lead(II) oxide with molten fatty acid. An idealized equation is:
In reality, lead soaps have complex formulas.
References
Laurates
Lead(II) compounds | Lead(II) laurate | [
"Chemistry"
] | 111 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
72,825,844 | https://en.wikipedia.org/wiki/The%20Little%20Princess%20Trust | The Little Princess Trust is a UK children's charity based in Hereford.
The charity provides free, real hair wigs to children and young people up to the age of 24 who have lost their own hair due to cancer treatment or to other conditions such as Alopecia.
History
The charity was founded by Wendy and Simon Tarplee in memory of their daughter Hannah Tarplee. Hannah was diagnosed with cancer when she was four and lost her hair during chemotherapy.
The Tarplees had problems finding a suitable wig for Hannah before she died in 2005.
The charity is also a significant supporter of childhood cancer research in the UK and one study at Manchester University NHS Foundation Trust, funded by The Little Princess Trust, has revealed an innovative new treatment for children with acute myeloid leukaemia who were previously on a palliative care pathway.
The Little Princess Trust moved into its own headquarters in 2021 and the new premises is called The Hannah Tarplee Building.
References
Hair
Wigs
Cancer
Charities based in the United Kingdom | The Little Princess Trust | [
"Biology"
] | 206 | [
"Organ systems",
"Hair"
] |
72,826,727 | https://en.wikipedia.org/wiki/Cyclooctanone | Cyclooctanone is an organic compound with the formula . It is a waxy white solid.
Synthesis and reactions
It can be prepared by
Jones oxidation or Dess-Martin oxidation of cyclooctanol.
ketonization reaction starting with azelaic acid.
Among its many reactions, Baeyer-Villiger oxidation gives the nine-membered cyclic ester.
See also
Suberone
References
8
Eight-membered rings | Cyclooctanone | [
"Chemistry"
] | 93 | [
"Organic chemistry stubs"
] |
72,826,783 | https://en.wikipedia.org/wiki/Exploration | Exploration is the process of exploring, an activity which has some expectation of discovery. Organised exploration is largely a human activity, but exploratory activity is common to most organisms capable of directed locomotion and the ability to learn, and has been described in, amongst others, social insects foraging behaviour, where feedback from returning individuals affects the activity of other members of the group.
Types
Geographical
Geographical exploration, sometimes considered the default meaning for the more general term exploration, is the practice of discovering lands and regions of the planet Earth remote or relatively inaccessible from the origin of the explorer. The surface of the Earth not covered by water has been relatively comprehensively explored, as access is generally relatively straightforward, but underwater and subterranean areas are far less known, and even at the surface, much is still to be discovered in detail in the more remote and inaccessible wilderness areas.
Two major eras of geographical exploration occurred in human history: The first, covering most of Human history, saw people moving out of Africa, settling in new lands, and developing distinct cultures in relative isolation. Early explorers settled in Europe and Asia; about 14,000 years ago, some crossed the Ice Age land bridge from Siberia to Alaska, and moved southwards to settle in the Americas. For the most part, these cultures were ignorant of each other's existence. The second period of exploration, occurring over the last 10,000 years, saw increased cross-cultural exchange through trade and exploration, and marked a new era of cultural intermingling, and more recently, convergence.
Early writings about exploration date back to the 4th millennium B.C. in ancient Egypt. One of the earliest and most impactful thinkers on exploration was Ptolemy in the 2nd century AD. Between the 5th century and 15th century AD, most exploration was done by Chinese and Arab explorers. This was followed by the Age of Discovery after European scholars rediscovered the works of early Latin and Greek geographers. While the Age of Discovery was partly driven by land routes outside of Europe becoming unsafe, and a desire for conquest, the 17th century also saw exploration driven by nobler motives, including scientific discovery and the expansion of knowledge about the world. This broader knowledge of the world's geography meant that people were able to make world maps, depicting all land known. The first modern atlas was the , published by Abraham Ortelius, which included a world map that depicted all of Earth's continents.
Underwater
Underwater exploration is the exploration of any underwater environment, either by direct observation by the explorer, or by remote observation and measurement under the direction of the investigators. Systematic, targeted exploration, with simultaneous survey, and recording of data, followed by data processing, interpretation and publication, is the most effective method to increase understanding of the ocean and other underwater regions, so they can be effectively managed, conserved, regulated, and their resources discovered, accessed, and used. Less than 10% of the ocean has been mapped in any detail, even less has been visually observed, and the total diversity of life and distribution of populations is similarly incompletely known.
Space
Space exploration is the use of astronomy and space technology to explore outer space. While the exploration of space is currently carried out mainly by astronomers with telescopes, its physical exploration is conducted both by uncrewed robotic space probes and human spaceflight. Space exploration, like its classical form astronomy, is one of the main sources for space science.
While the observation of objects in space, known as astronomy, predates reliable recorded history, it was the development of large and relatively efficient rockets during the mid-twentieth century that allowed physical extraterrestrial exploration to become a reality. Common rationales for exploring space include advancing scientific research, national prestige, uniting different nations, ensuring the future survival of humanity, and developing military and strategic advantages against other countries.
Urban
Urban exploration is the exploration of manmade structures, usually abandoned ruins or hidden components of the manmade environment. Photography and historical interest/documentation are heavily featured in the hobby, sometimes involving trespassing onto private property.
The activity presents various risks, including physical danger and, if done illegally and/or without permission, the possibility of arrest and punishment. Some activities associated with urban exploration violate local or regional laws and certain broadly interpreted anti-terrorism laws, or can be considered trespassing or invasion of privacy.
Geological
Traditionally, mineral exploration relied on direct observation of mineralisation in rock outcrops or in sediments. More recently, however, mineral exploration also includes the use of geologic, geophysical, and geochemical tools to search for anomalies, which can narrow the search area. The area to be prospected should be covered sufficiently to minimize the risk of missing something important, but it can take into account previous experience that certain geological evidence correlates with a very low probability of finding the desired minerals. Other evidence indicates a high probability, making it efficient to concentrate on the areas of high probability when they are found, and for the skipping areas of very low probability. Once an anomaly has been identified and interpreted to be a prospect, more detailed exploration of the potential reserve can be done by soil sampling, drilling, seismic surveys, and similar methods to assess the most appropriate method and type of mining and the economic potential.
Modes
Systematic examination or investigation
Systematic investigation is done in an orderly and organised manner, generally following a plan, though it should be a flexible plan, which is amenable to rational adaptation to suit circumstances, as the concept of exploration accepts the possibility of the unexpected being encountered, and the plan must survive such encounters to remain useful.
Diagnostical examination
Diagnosis is the identification of the nature and cause of a given phenomenon. Diagnosis is used in many different disciplines, such as medicine, forensic science and engineering failure analysis, with variations in the use of logic, analytics, and experience, to determine causality. A diagnostic examination explores the available evidence to try to identify likely causes for observed effects, and may also investigate further with the intention to discover additional relevant evidence. This is an instance of inspective and extrinsic exploration.
To seek experience first hand
Exploration as the pursuit of first hand experience and knowledge is often an example of diversive and intrinsic exploration when done for personal satisfaction and entertainment, though it may also be for purposes of learning or verifying the information provided by others, which is an extrinsic motivation, and which is likely to be characterised by a relatively systematic approach. As the personal aspect of the experience is central to this type of exploration, the same region or range of experiences may be explored repeatedly by different people, for each can have a reasonable expectation of personal discovery.
Exploratory behavior in animals
Exploratory behavior has been defined as behavior directed toward getting information about the environment, or to locate things such as food or individuals. Exploration usually follows a sequence, in which four stages can be identified. The first phase is search, in which the subject moves around to contact relevant stimuli, to which the subject pays attention, and may approach and investigate. The sequence may be interrupted by flight if danger is recognised, or a return to search if the stimulus is not interesting or useful.
In all these definitions there is an implication of novelty, or unfamiliarity or the expectation of discovery in the exploration, whereas a survey implies directed examination, but not necessarily discovery of any previously unknown or unexpected information. The activities are not mutually exclusive, and often occur simultaneously to a variable extent. The same field of investigation or region may be explored at different times by different explorers with different motivations, who may make similar or different discoveries.
See also
Explorers:
References
Further reading
General
Baker, J. N. L. A History of Geographical Discovery and Exploration. Rev. ed. New York: Cooper Square Publishers, 1967.
Beaglehole, J. C. The Exploration of the Pacific. 3rd ed. Stanford, CA: Stanford University Press, 1966.
Boorstin, Daniel. The Discoverers. New York: Random House, 1983.
Brown, Lloyd A. The Story of Maps. New York: Dover Publications, 1979.
Bitterli, Urs. Cultures in Conflict: Encounters Between European and Non-European Cultures, 1492–1800. Translated by Ritchie Robertson. Stanford, CA: Stanford University Press, 1989.
Buisseret, David, ed. The Oxford Companion to World Exploration. Oxford: Oxford University Press, 2007.
Cannon, Michael. The Exploration of Australia. Sydney: Reader’s Digest Services, 1987.
Crosby, Alfred W. The Columbian Exchange: Biological and Social Consequences of 1492. Westport, CT: Greenwood Press, 1972.
Crosby, Alfred W. Ecological Imperialism: The Biological Expansion of Europe, 900–1900. 2nd ed. Cambridge: Cambridge University Press, 2004.
Fernández-Armesto, Felipe. 1492: The Year the World Began. New York: HarperOne, 2009.
Fernández-Armesto, Felipe. Pathfinders: A Global History of Exploration. New York: Norton, 2006.
Fernández-Armesto, Felipe, ed. The Times Atlas of World Exploration: 3,000 Years of Exploring, Explorers, and Mapmaking. New York: Times Books, 1991.
Fernlund, Kevin Jon. A Big History of North America, from Montezuma to Monroe. Columbia: University of Missouri Press, 2022.
Goetzmann, William H. New Lands, New Men: America and the Second Great Age of Discovery. New York: Viking Press, 1986.
Goetzmann, William H. and Glyndwr Williams. The Atlas of North American Exploration: From the Norse Voyages to the Race to the Pole. New York: Prentice Hall, 1992.
Hall, D. H. History of the Earth Sciences During the Scientific and Industrial Revolutions, with Special Emphasis on the Physical Geosciences. Amsterdam: Elsevier Scientific Publishing, 1976.
von Hagen, Victor Wolfgang. South America Called Them: Explorations of the Great Naturalists: La Condamine, Humboldt, Darwin, Spruce. New York: Alfred A. Knopf, 1945.
Hakluyt Society, Series I and II. Some 290 volumes of original accounts in English translation. See also its periodical, Journal of the Hakluyt Society.
Mann, Charles C. 1493: Uncovering the New World Columbus Created. New York: Alfred A. Knopf, 2011.
McNeill, William. Plagues and Peoples. New York: Knopf Doubleday, 1977.
Mountfield, David. A History of African Exploration. Northbrook, IL: Domus Books, 1976.
Mountfield, David. A History of Polar Exploration. New York: Dial Press, 1974.
Oxford University Press. Oxford Atlas of Exploration. 2nd ed. New York: Oxford University Press, 2008.
Parry, J. H. The Age of Reconnaissance: Discovery, Exploration and Settlement 1450–1650. Berkeley: University of California Press, 1963.
Parry, J. H. The Discovery of South America. New York: Taplinger, 1979.
Pyne, Stephen J. The Great Ages of Discovery: How Western Civilization Learned About a Wider World. Tucson: University of Arizona Press, 2021.
Reader’s Digest. Antarctica: Great Stories from the Frozen Continent. Surrey Hills, NSW: Reader’s Digest Services, 1985.
Richards, John F. The Unending Frontier: An Environmental History of the Early Modern World. Berkeley: University of California Press, 2003.
Pre-Renaissance
Fernández-Armesto, Felipe. Before Columbus: Exploration and Colonisation from the Mediterranean to the Atlantic, 1229–1492. London: Macmillan Education, 1987.
Haywood, John. Ocean: A History of the Atlantic Before Columbus. London: Head of Zeus, 2024.
Jones, Gwyn. The Norse Atlantic Saga. 2nd ed. New York: Oxford University Press, 1986.
Sauer, Carl O. Northern Mists. Berkeley: University of California Press, 1968.
Scammell, G. V. The World Encompassed: The First European Maritime Empires c. 800–1650. Berkeley: University of California Press, 1981.
Exploration and Empire
Aldrich, Robert. Greater France: A History of French Oversea Expansion. New York: St. Martin’s Press, 1996.
Bleichmar, Daniela, ed., Science in the Spanish and Portuguese Empires, 1500–1800. Stanford, CA: Stanford University Press, 2009.
Boxer, C. R. The Dutch Seaborne Empire 1600–1800. New York: Viking Penguin, 1965.
Boxer, C. R. The Portuguese Seaborne Empire 1415–1825. New York: Alfred A. Knopf, 1975.
Crowley, Roger. City of Fortune: How Venice Ruled the Seas. New York: Random House, 2013.
Cuyvers, Luc. Into the Rising Sun: Vasco da Gama and the Search for the Sea Route to the East. New York: TV Books, 1999.
DeVoto, Bernard. The Course of Empire. Boston: Houghton Mifflin, 1952.
Diffie, Bailey W., and George D. Winius. Foundations of the Portuguese Empire 1415–1580. Minneapolis: University of Minnesota Press, 1977.
Dreyer, Edward L. Zheng He: China and the Oceans in the Early Ming Dynasty, 1405–1433. New York: Pearson Longman, 2007.
Elliott, J. H. Imperial Spain 1469–1716. London: Penguin, 1963.
Engstrand, Iris H. W. Spanish Scientists in the New World: The Eighteenth-Century Expeditions. Seattle: University of Washington Press, 1981.
Fernández-Armesto, Felipe. The Canary Islands After the Conquest: The Making of a Colonial Society in the Early Sixteenth Century. Oxford: Clarendon Press, 1982.
Goetzmann, William H. Exploration and Empire: The Explorer and the Scientist in the Winning of the American West. New York: Alfred A. Knopf. (1967).
Grove, Richard H. Green Imperialism: Colonial Expansion, Tropical Island Edens, and the Origins of Environmentalism, 1600–1860. Cambridge: Cambridge University Press, 1995.
Jane, Cecil Jane, trans. and ed., The Four Voyages of Columbus. New York: Dover Publications, 1988.
Leonard, Irving A. Books of the Brave: Being an Account of Books and of Men in the Spanish Conquest and Settlement of the Sixteenth-Century New World. Berkeley: University of California Press, 1992.
Lloyd, T. O. The British Empire, 1558–1983. New York: Oxford University Press, 1984.
Lewis, Bernard. The Muslim Discovery of Europe. New York: W. W. Norton, 2001.
Moorehead, Alan. The Fatal Impact: The Invasion of the South Pacific 1767–1840. New York: Harper and Row, 1987.
Morison, Samuel Eliot. The European Discovery of America: The Northern Voyages, A.D. 500–1600. New York: Oxford University Press, 1971.
Morison, Samuel Eliot. The European Discovery of America: The Southern Voyages, 1492–1616. New York: Oxford University Press, 1971.
Morison, Samuel Eliot. The Great Explorers: The European Discovery of America. New York: Oxford University Press, 1978.
Newitt, Malyn. A History of Portuguese Overseas Expansion, 1400–1668. New York: Routledge, 2005.
Parry, J. H. The Establishment of the European Hegemony 1415–1715: Trade and Exploration in the Age of the Renaissance. 3rd ed., rev. New York: Harper Torchbooks, 1966.
Parry, J. H. The Spanish Seaborne Empire. Berkeley: University of California Press, 1990.
Penrose, Boies. Travel and Discovery in the Renaissance 1420–1640. New York: Atheneum, 1975.
Sauer, Carl O. The Early Spanish Main. Berkeley: University of California Press, 1966.
Sauer, Carl O. Seventeenth Century North America. Berkeley: Turtle Island, 1980.
Sauer, Carl O. Sixteenth Century North America. Berkeley: University of California Press, 1971.
The Continents
Alexander von Humboldt. Netzwerke des Wissens. Ostfildern: Hatje Cantz, 1999.
Bartlett, Richard W. Great Surveys of the American West. Norman: University of Oklahoma Press, 1980.
Becker, Peter. The Pathfinders: The Saga of Exploration in Southern Africa. Harmondsworth, UK: Penguin, 1985.
Bitterli, Urs. Cultures in Conflict: Encounters Between European and Non-European Cultures, 1492–1800. Translated by Ritchie Robertson. Stanford, Calif.: Stanford University Press, 1989.
Blainey, Geoffrey. A Land Half Won. South Melbourne: Macmillan Company of Australia, 1980.
Blunt, Wilfred. Linnaeus: The Compleat Naturalist. Princeton, N.J.: Princeton University Press, 2001.
Botting, Douglas. Humboldt and the Cosmos. New York: Harper and Row, 1973.
Bough, Barry M. First Across the Continent: Sir Alexander Mackenzie. Norman: University of Oklahoma Press, 1997.
Cannon, Michael. The Exploration of Australia. Sydney: Reader’s Digest Services, 1987.
de Terra, Helmut. Humboldt: The Life and Times of Alexander von Humboldt, 1769–1859. New York: Octagon Books, 1979.
DeVoto, Bernard. The Journals of Lewis and Clark. Boston: Houghton Mifflin, 1953.
Fernlund, Kevin J. William Henry Holmes and the Rediscovery of the American West. Albuquerque: University of New Mexico, 2000.
Ferreiro, Larrie D. Measure of the Earth: The Enlightenment Expedition That Reshaped Our World. New York: Basic Books, 2011.
Ford, Corey. Where the Sea Breaks its Back: The Epic Story of Early Naturalist Georg Steller and the Russian Exploration of Alaska. Boston: Little, Brown, 1966.
Goetzmann, William H. Army Exploration in the American West, 1803–1863. New Haven: Yale University Press, 1959.
Goetzmann, William H. "The Role of Discovery in American History," in American Civilization, ed. Daniel J. Boorstin. New York: McGraw-Hill, 1972.
Jeal, Tim. Stanley: The Impossible Life of Africa’s Greatest Explorer. New Haven, Conn.: Yale University Press, 2007.
McIntyre, Kenneth Gordon. The Secret Discovery of Australia: Portuguese Ventures 250 Years Before Captain Cook. Sydney: Picador, 1977.
Pyne, Stephen J. Grove Karl Gilbert: A Great Engine of Research. Iowa City: University of Iowa Press, 2007.
Pyne, Stephen J. How the Canyon Became Grand: A Short History. New York: Viking, 1998.
Rayfield, Donald. The Dream of Lhasa: The Life of Nikolay Przhevalsky (1839–88), Explorer of Central Asia. Athens: Ohio University Press, 1976.
Ronda, James. Finding the West: Explorations with Lewis and Clark. Norman: University of Oklahoma Press. 2001.
Ross, John F. The Promise of the Grand Canyon: John Wesley Powell's Perilous Journey and His Vision for the American West. New York: Viking, 2018.
Schullery, Paul, ed. The Grand Canyon: Early Impressions. Boulder: Colorado Associated University Press, 1981.
Stegner, Wallace. Beyond the Hundredth Meridian: John Wesley Powell and the Second Opening of the West. Boston: Houghton Mifflin and Company, 1953.
Vigil, Ralph H. "Spanish Exploration and the Great Plains in the Age of Discovery: Myth and Reality." Great Plains Quarterly 10, no. 1 (1990): 3–17.
Weber, David J. Richard H. Kern: Expeditionary Artist in the Far Southwest, 1848–1853. Fort Worth: Amon Carter Museum, 1985.
The Oceans
Ballard, Robert, with Will Hively. The Eternal Darkness: A Personal History of Deep-Sea Exploration. Princeton, N.J.: Princeton University Press, 2000.
Corfield, Richard. The Silent Landscape: The Scientific Voyage of HMS Challenger. Washington, D.C.: Joseph Henry Press, 2003.
Hamblin, Jacob Darwin. Oceanographers and the Cold War: Disciples of Marine Science. Seattle: University of Washington Press, 2005.
Hannigan, John. The Geopolitics of Deep Oceans. Cambridge: Polity Press, 2016.
Hellwarth, Ben. SEALAB: America’s Forgotten Quest to Live and Work on the Ocean Floor. New York: Simon and Schuster, 2012.
Hsü, Kenneth J. The Mediterranean Was a Desert: A Voyage of the Glomar Challenger. Princeton, N.J.: Princeton University Press, 1983.
Koslow, Tony. The Silent Deep: The Discovery, Ecology and Conservation of the Deep Sea. Chicago: University of Chicago Press, 2007.
Kroll, Gary. America’s Ocean Wilderness: A Cultural History of Twentieth-Century Exploration. Lawrence: University Press of Kansas, 2008.
Linklater, Eric. The Voyage of the Challenger. Garden City, N.Y.: Doubleday, 1972.
Menard, H. W. The Ocean of Truth: A Personal History of Plate Tectonics. Princeton, N.J.: Princeton University Press, 1986.
Parry, J. H. The Discovery of the Sea. Berkeley: University of California Press, 1974.
Rozwadowski, Helen M. Fathoming the Ocean: The Discovery and Exploration of the Deep Sea. Cambridge, MA: Harvard University Press, 2005.
Schlee, Susan. The Edge of an Unfamiliar World: A History of Oceanography. New York: E. P. Dutton, 1973.
The Poles
Beattie, Owen, and John Geiger. Frozen in Time: The Fate of the Franklin Expedition. Toronto: Greystone Books, 1998.
Belanger, Dian Olson. Deep Freeze: The United States, the International Geophysical Year, and the Origins of Antarctica’s Age of Science. Boulder: University Press of Colorado, 2006.
Joyner, Christopher C. Governing the Frozen Commons: The Antarctic Regime and Environmental Protection. Columbia: University of South Carolina Press, 1998.
Pyne, Stephen J. The Ice: A Journey to Antarctica. Iowa City: University of Iowa Press, 1986
Peterson, J. J. Managing the Frozen South: The Creation and Evolution of the Antarctic Treaty System. Berkeley: University of California Press, 1988.
Rose, Lisle E. Assault on Eternity: Richard E. Byrd and the Exploration of Antarctica, 1946–47. Annapolis, Md.: Naval Institute Press, 1980.
Sullivan, Walter. Assault on the Unknown: The International Geophysical Year. New York: McGraw-Hill, 1961.
Space
Burrows, William E. Exploring Space: Voyages in the Solar System and Beyond. New York: Random House, 1990.
Burrows, William E. This New Ocean: The Story of the First Space Age. New York: Modern Library, 1999.
Chaikin, Andrew. A Man on the Moon. New York: Penguin, 1994.
Cooper, Henry S. F., Jr. The Evening Star: Venus Observed. Baltimore, Md.: Johns Hopkins University Press, 1994.
Cooper, Henry S. F., Jr. Imaging Saturn: The Voyager Flights to Saturn. New York: Holt, Rinehart and Winston, 1982.
Cooper, Henry S. F., Jr. The Search for Life on Mars: Evolution of an Idea. New York: Holt, Rinehart, and Winston, 1981.
Hartmann, William K., et al, eds. In the Stream of Stars: The Soviet/American Space Art Book. New York: Workman, 1990.
Harvey, Brian. Russia in Space: The Failed Frontier? Chicheser, UK: Praxis, 2001.
Harvey, Brian. Russian Planetary Exploration: History, Development, Legacy and Prospects. Chichester, UK: Praxis, 2007.
Kilgore, De Witt Douglas. Astrofuturism: Science, Race, and Visions of Utopia in Space. Philadelphia: University of Pennsylvania Press, 2003.
Kraemer, Robert S. Beyond the Moon: A Golden Age of Planetary Exploration 1971–1978. Washington, D.C.: Smithsonian Institution Press, 2000.
Launius, Roger D. Apollo’s Legacy: Perspectives on the Moon Landings. Washington, D.C.: Smithsonian Books, 2019.
Launius, Roger D., and Howard E. McCurdy. Robots in Space: Technology, Evolution, and Interplanetary Travel. Baltimore, Md.: Johns Hopkins Press, 2008.
McDougall, Walter A. The Heavens and the Earth: A Political History of the Space Age. New York: Basic Books, 1985.
Miller, Ron. The Art of Space: The History of Space Art, from the Earliest Visions to the Graphics of the Modern Era. Minneapolis, Minn.: Zenith Press, 2014.
Murray, Bruce. Journey into Space: The First Thirty Years of Space Exploration. New York: W. W. Norton, 1989.
Poole, Robert. Earthrise: How Man First Saw the Earth. New Haven, Conn.: Yale University Press, 2008.
Pyne, Stephen J. Voyager: Seeking Newer Worlds in the Third Great Age of Discovery. New York: Viking, 2010.
Roland, Alex. A Spacefaring People: Perspectives on Early Spaceflight. Washington, D.C.: NASA, 1985.
Sagan, Carl. Pale Blue Dot: A Vision of the Human Future in Space. New York: Ballantine, 1994.
Westwick, Peter J. Into the Black: JPL and the American Space Program 1976–2004. New Haven, Conn.: Yale University Press, 2007.
Wilkins, Don E. To a Rocky Moon: A Geologist’s History of Lunar Exploration. Tucson: University of Arizona Press, 1993.
Wilson, J. Tuzo. IGY: The Year of the New Moons. New York: Alfred A. Knopf, 1961.
Human activities
Discoveries
Field research
Geography
History by topic
Types of travel | Exploration | [
"Biology"
] | 5,327 | [
"Human activities",
"Behavior",
"Human behavior"
] |
72,826,846 | https://en.wikipedia.org/wiki/Hydrogen-bonded%20organic%20framework | Hydrogen-bonded organic frameworks (HOFs) are a class of porous polymers formed by hydrogen bonds among molecular monomer units to afford porosity and structural flexibility. There are diverse hydrogen bonding pair choices that could be used in HOFs construction, including identical or nonidentical hydrogen bonding donors and acceptors. For organic groups acting as hydrogen bonding units, species like carboxylic acid, amide, 2,4-diaminotriazine, and imidazole, etc., are commonly used for the formation of hydrogen bonding interaction. Compared with other organic frameworks, like COF and MOF, the binding force of HOFs is relatively weaker, and the activation of HOFs is more difficult than other frameworks, while the reversibility of hydrogen bonds guarantees a high crystallinity of the materials. Though the stability and pore size expansion of HOFs has potential problems, HOFs still show strong potential for applications in different areas.
An important consequence of the natural porous architecture of hydrogen-bonded organic frameworks is to realize the adsorption of guest molecules. This character accelerates the emergence of various applications of different HOFs structures, including gas removal/storage/separation, molecule recognition, proton conduction, and biomedical applications, etc.
History
Reports of extended 2D hydrogen-bonding-based porous frameworks can be traced back to the 1960s. In 1969, Duchamp and Marsh reported a 2D interpenetrated nonporous crystal structure with a honeycomb network constructed by benzene-1,3,5-tricarboxylic acid (trimesic acid or TMA). Then Ermer reported an adamantane-1,3,5,7-tetracarboxylic acid (ADTA) based hydrogen-bonded network with interpenetrated diamond topology. Meanwhile diverse works of guest-induced hydrogen-bonded frameworks were reported successively, which gradually developed the concept of hydrogen-bonded organic frameworks. Another milestone in the evolution of hydrogen-bonded organic frameworks was set by Chen. In 2011, Chen reported a porous organic framework with hydrogen bonding as binding force and demonstrated its porosity by gas adsorption for the first time. Since then, numerous HOF structures have been designed and constructed, meanwhile various applications related to porous frameworks have been attempted and applied to HOFs, whose effectiveness has been proved.
Hydrogen bonding pairs in HOFs
Hydrogen bonds formed among various monomers guarantee the construction of hydrogen-bonded organic frameworks with different assembly architectures. The constitution of the hydrogen pairs is based on the structural and functional design of the HOFs, therefore different hydrogen bonding pairs should be selected following systematic requirements. The hydrogen bonding pairs generally include 2,4-diaminotriazine, carboxylic acid, amide, imide, imidazole, imidazolone and resorcinol, etc. Assorting with appropriate backbones, in every crystallization condition, the hydrogen-bonding pairs will exhibit specific assembly states, which means the morphologies with favored energy for this crystallization condition could be assembled by the monomers. In order to realize 2D or 3D HOFs, monomers with more than one hydrogen bonding pair are generally considered: the rigidity and directionality are also in favor of HOF construction.
Backbones of HOF monomer
Rigidity and directionality of the constructional units offer HOFs various pore structures, topologies, and further applications. Therefore, a proper choice of monomer backbones plays an important role in the construction of HOFs. These backbones not only can combine with different hydrogen bonding pairs mentioned above to realize stable HOF structural design and expand pore size, but also give opportunities to offer more topologies of HOFs. Also, by using backbones with similar geometry and same connection pattern to generate the monomers and HOFs, the isoreticular expansion of the frameworks becomes a reliable method to expand the pore size effectively. As mentioned, for the sake of constructing porous and stable HOFs, multiple aspects should be considered simultaneously, such as the rigidity of the backbones, the orientation and binding strength of the hydrogen pairs, and other intermolecular interactions for orderly stacking. Therefore, the design of HOF monomers should focus on their H-bonds orientations and structural rigidity, and consequent framework stability and porosity.
Synthetic methods
In principle, HOFs could be crystallized from solvents. However, the factors of solvent types, precursor concentration, crystallization time and temperature, etc., can have significant influence on HOFs crystallization process. Generally, the crystal products can correspond to kinetics through high concentration and short crystallization time, while slowing down the crystallization rate might yield thermodynamic crystals. One common method to produce HOF crystal is to slowly evaporate the solvent of the solution, which benefits the stacking of the monomers. Another widely used method is to diffuse low boiling point poor solvents into monomer solution with higher boiling point good solvents, in order to induce the assembly of the monomers. Depending on different crystallization systems, other methods have also been applied to HOF construction.
Characterization methods
There are various methods to characterize HOF materials and their monomers. Nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS) are generally used for characterizing the synthesis of monomers. Single crystal X-ray diffraction (SCXRD) is the powerful tool for determining the structure of the HOF crystal packing. Powder X-ray diffraction (PXRD) is also a supported technique to demonstrate the pure phase formation of HOFs. The gas adsorption and desorption study through Brunauer-Emmett-Teller (BET) method could reasonably demonstrate some key parameters of HOFs, like pore size, specific gas adsorption amount and surface area from the adsorption isotherms. Depending on application directions and study fields, diverse techniques have been applied to the characterization of HOFs.
Applications
The porous structures and unique properties guarantee HOFs good application performance in practical fields. The applications include but are not limited to gas adsorption, hydrocarbon separation, proton conductivity, and molecular recognition, etc.
Gas adsorption
As a kind of networks with tailorable pore size, HOFs could serve as storage containers for gas molecules with certain sizes and interactions. The relatively constrained pore size in HOFs could help to store, capture, or separate different small gas molecules, including H2, N2, CO2, CH4, C2H2, C2H4, C2H6 and so on. Mastalerz and Oppel reported a special 3D HOF with triptycene trisbenzimidazolone (TTBI) as constitutional monomers. Because of the molecular rigidity and stereo construction, 1D channels were formed through the frameworks and the surface area was largely enhanced, to the extent of 2796 m2/g as shown by BET. The HOF also presented good adsorption ability of H2 and CO2, as 243 and 80.7 cm3/g at 1 bar at 77 and 273 K, separately.
CO2 adsorption
As a typical greenhouse gas that could cause serious problems in many aspects, the capture of carbon dioxide is always under big concern. Meanwhile, carbon dioxide has also been widely used as a gas resource or emitted as waste gas in manufacturing and industry, therefore the storage and separation of CO2 have always been emphasized as an important application. Chen and co-workers reported a structural transformation HOF with high CO2 adsorption capacity in 2015. The N–H···N hydrogen bond is formed between the units to realize the assembly of the HOF architecture with binodal topology. The CO2 uptake capacity of the HOF could reach 117.1 cm3/g at 273 K.
Hydrocarbon separation
The hydrogen-bonded organic framework used for C2H2/C2H4 separation was reported by Chen and coworkers. In the structure of this HOF, each 4,4',4'',4'''-tetra(4,6-diamino-s-triazin-2-yl)tetraphenylmethane unit connected with eight other units by N–H···N hydrogen bonds. Due to certain structural flexibility, the framework was able to uptake C2H2 up to 63.2 cm3/g while the adsorption amount of C2H4 was 8.3 cm3/g at 273 K, showing effective C2H2/C2H4 separation.
Molecules recognition
The non-covalent interactions existing in the hydrogen-bonded organic frameworks, e.g., hydrogen bonding, π-π interaction and Van der Waals force, are considered as important intermolecular interactions for molecules recognition. Meanwhile, the multiple binding sites and adaptable structures also make HOFs good molecules recognition platform. By exploiting these features, so far different kinds of recognition have been realized, including gas molecules recognition, fullerene recognition, aniline recognition, pyridine recognition, etc.
Optical materials
Some luminescence molecules with large π conjugation structures are also used for HOFs construction. Therefore, various luminescent HOFs are designed and assembled in order to realize the non-covalent controlled luminescence adjustment which could introduce more functions to the HOF materials. For example, by using tetraphenylethylene (TPE) as backbones, a series of HOFs combined with solvents presenting different color emission have been reported.
Proton conduction
The hydrogen-bonded organic frameworks constructed with proton carriers have been widely used for proton conduction. The hydrogen bonds can also serve as proton sources in the frameworks to transfer protons. As an example, porphyrin-based structures and guanidinium sulfonate salt monomers have been studied and included in HOF design and construction for proton conduction since the certain conductivity they have.
Biological applications
As kinds of metal-free porous materials, hydrogen-bonded organic frameworks are also ideal platform for drug delivery and disease treatment. Meanwhile, with proper monomer selection and reasonable arrangement, Cao reported a robust HOF which could effectively encapsulate a cancer drug Doxorubicin and yield singlet oxygen by embedded photoactive pyrene moiety in order to realize dual functions of drug release and photodynamic therapy for cancer remedy.
References | Hydrogen-bonded organic framework | [
"Chemistry",
"Materials_science"
] | 2,175 | [
"Porous polymers",
"Hydrogen-bonded organic frameworks"
] |
72,827,238 | https://en.wikipedia.org/wiki/Branched%20pathways | Branched pathways, also known as branch points (not to be confused with the mathematical branch point), are a common pattern found in metabolism. This is where an intermediate species is chemically made or transformed by multiple enzymatic processes. linear pathways only have one enzymatic reaction producing a species and one enzymatic reaction consuming the species.
Branched pathways are present in numerous metabolic reactions, including glycolysis, the synthesis of lysine, glutamine, and penicillin, and in the production of the aromatic amino acids.
In general, a single branch may have producing branches and consuming branches. If the intermediate at the branch point is given by , then the rate of change of is given by:
At steady-state when the consumption and production rates must be equal:
Biochemical pathways can be investigated by computer simulation or by looking at the sensitivities, i.e. control coefficients for flux and species concentrations using metabolic control analysis.
Elementary properties
A simple branched pathway has one key property related to the conservation of mass. In general, the rate of change of the branch species based on the above figure is given by:
At steady-state the rate of change of is zero. This gives rise to a steady-state constraint among the branch reaction rates:
Such constraints are key to computational methods such as flux balance analysis.
Control properties of a branch pathway
Branched pathways have unique control properties compared to simple linear chain or cyclic pathways. These properties can be investigated using metabolic control analysis. The fluxes can be controlled by enzyme concentrations , , and respectively, described by the corresponding flux control coefficients. To do this the flux control coefficients with respect to one of the branch fluxes can be derived. The derivation is shown in a subsequent section. The flux control coefficient with respect to the upper branch flux, are given by:
where is the fraction of flux going through the upper arm, , and the fraction going through the lower arm, . and are the elasticities for with respect to and respectively.
For the following analysis, the flux will be the observed variable in response to changes in enzyme concentrations.
There are two possible extremes to consider, either most of the flux goes through the upper branch or most of the flux goes through the lower branch, . The former, depicted in panel a), is the least interesting as it converts the branch in to a simple linear pathway. Of more interest is when most of the flux goes through
If most of the flux goes through , then and (condition (b) in the figure), the flux control coefficients for with respect to and can be written:
That is, acquires proportional influence over its own flux, . Since only carries a very small amount of flux, any changes in will have little effect on . Hence the flux through is almost entirely governed by the activity of . Because of the flux summation theorem and the fact that , it means that the remaining two coefficients must be equal and opposite in value. Since is positive, must be negative. This also means that in this situation, there can be more than one Rate-limiting step (biochemistry) in a pathway.
Unlike a linear pathway, values for and are not bounded between zero and one. Depending on the values of the elasticities, it is possible for the control coefficients in a branched system to greatly exceed one. This has been termed the branchpoint effect by some in the literature.
Example
The following branch pathway model (in antimony format) illustrates the case and have very high flux control and step J2 has proportional control.
J1: $Xo -> S1; e1*k1*Xo
J2: S1 ->; e2*k3*S1/(Km1 + S1)
J3: S1 ->; e3*k4*S1/(Km2 + S1)
k1 = 2.5;
k3 = 5.9; k4 = 20.75
Km1 = 4; Km2 = 0.02
Xo =5;
e1 = 1; e2 = 1; e3 = 1
A simulation of this model yields the following values for the flux control coefficients with respect to flux
Branch point theorems
In a linear pathway, only two sets of theorems exist, the summation and connectivity theorems. Branched pathways have an additional set of branch centric summation theorems. When combined with the connectivity theorems and the summation theorem, it is possible to derive the control equations shown in the previous section. The deviation of the branch point theorems is as follows.
Define the fractional flux through and as and respectively.
Increase by . This will decrease and increase through relief of product inhibition.
Make a compensatory change in by decreasing such that is restored to its original concentration (hence ).
Since and have not changed, .
Following these assumptions two sets of equations can be derived: the flux branch point theorems and the concentration branch point theorems.
Derivation
From these assumptions, the following system equation can be produced:
Because and, assuming that the flux rates are directly related to the enzyme concentration thus, the elasticities, , equal one, the local equations are:
Substituting for in the system equation results in:
Conservation of mass dictates since then . Substitution eliminates the term from the system equation:
Dividing out results in:
and can be substituted by the fractional rates giving:
Rearrangement yields the final form of the first flux branch point theorem:
Similar derivations result in two more flux branch point theorems and the three concentration branch point theorems.
Flux branch point theorems
Concentration branch point theorems
Following the flux summation theorem and the connectivity theorem the following system of equations can be produced for the simple pathway.
Using these theorems plus flux summation and connectivity theorems values for the concentration and flux control coefficients can be determined using linear algebra.
See also
Control coefficient (biochemistry)
Elasticity coefficient
Metabolic control analysis
References
Metabolic pathways | Branched pathways | [
"Chemistry"
] | 1,208 | [
"Metabolic pathways",
"Metabolism"
] |
72,827,868 | https://en.wikipedia.org/wiki/List%20of%20malvid%20families | The malvids consist of eight orders of flowering plants: Brassicales, Crossosomatales, Geraniales, Huerteales, Malvales, Myrtales, Picramniales and Sapindales. This subgroup of the rosids is divided into 59 families of trees, shrubs, vines and herbaceous plants.
The cabbage family includes broccoli, turnips and radishes. The ornamental geraniums, and their many hybrids and cultivars, come from five species of Pelargonium. The mallow family includes the plants that yield cocoa beans, Cola nuts, cotton and jute. Pomegranates were cultivated by Bronze Age cultures, and wild water chestnuts were consumed in large quantities by prehistoric Europeans. Eucalyptus trees are the tallest known flowering plants, up to or more; they are grown for timber and for their oils, used in candy, perfumes and cough medicine. Mangos and cashews come from the same plant family as poison ivy, and can sometimes trigger allergic reactions. Canada produces most of the world's maple syrup, and the maple leaf is the country's national symbol. Citrus agriculture outranks other sweet-fruit industries in warm climates.
Glossary
From the glossary of botanical terms:
annual: a plant species that completes its life cycle within a single year or growing season
basal: attached close to the base (of a plant or an evolutionary tree diagram)
climber: a vine that leans on, twines around or clings to other plants for vertical support
deciduous: falling seasonally, as with bark, leaves, or petals
glandular hair: a hair tipped with a secretory structure
herbaceous: not woody; usually green and soft in texture
mangrove: any shrub or small tree growing in brackish or salt water
perennial: not an annual or biennial
succulent (adjective): juicy or fleshy
unisexual: of one sex; bearing only male or only female reproductive organs
woody: hard and lignified; not herbaceous
The APG IV system is the fourth in a series of plant taxonomies from the Angiosperm Phylogeny Group. In this system, Geraniales and Myrtales are basal within the malvids.
Families
See also
List of plant family names with etymologies
Notes
Citations
References
See the Creative Commons license.
See their terms-of-use license.
Systematic
Malvid
Malvid families
malvid families
Rosids | List of malvid families | [
"Biology"
] | 505 | [
"Lists of biota",
"Lists of plants",
"Plants"
] |
72,828,156 | https://en.wikipedia.org/wiki/Negative%20methane | Negative methane is the negative ion of methane, meaning that a neutral methane molecule captured an extra electron and became an ion with a total negative electric charge: CH4−. This kind of ion is also known as anion and are relevant in nature because negative ions have been observed to have important roles in several environments. For instance, they are confirmed in the interstellar space, in plasma, in the atmosphere of Earth and, in the ionosphere of Titan. Negative ions also hold the key for the radiocarbon dating method
Negative ions can not be described with conventional atomic theory. Quantum mechanical models, including more factors than solely Coulomb attraction, have to be considered to explain their stability. Such factors are Coulomb potential screening and electron correlation.
Relevance
Negative methane is important for fundamental science because methane was not expected to produce a stable negative state. It is also relevant because the existence of its negative ion demonstrates an extra property of this powerful greenhouse gas. It is also relevant for plasma science, specially for methane-based plasma. In addition, it may be important in some atmospheric environments, where there exists methane, like in the ionosphere of satellite Titan where negative ion species have been detected.
Negative ions are metastable because they decay over time, releasing the extra electron. Therefore, they can act as time-dependent-sources of thermal electrons (low energy) in plasma environments. Negative ion's ubiquitous presence in the interstellar medium, for example, prompts the question of an efficient formation mechanism since they are expected to decay over time. In addition, their extra electron is in general weakly attached to its neutral core and as a consequence, it is also expected to lose the additional electron with a large probability, prompting again the question of the mechanism of its formation.
History
Negative methane was not identified for at least two reasons. In mass spectrometers, its characteristic mark at m/q = -16 is similar to that of the well known anion of oxygen O−. Because, oxygen is present in most mass spectrometers as a very habitual contaminant from the atmosphere, detections of any signal at this particular mark of m/q = -16 were readily attributed to the anion of oxygen and not to methane's.
Second, in chemistry, methane is the molecular isoelectronic analogous to neon gas. Since neon does not have a known stable negative ion state, methane was not expected to support an extra electron either.
However, its molecular nature allows more degrees of freedom that allow for the formation of a negative ion. By a change of its nuclear configuration to form a Feshback negative ion resonance in which the electrons or nuclei of the molecule can re-arrange to form an excited state capable of supporting the extra electron.
Detection and structure
The existence of a stable state of negative methane was first reported in 2014. In this report, some of its properties were measured, like its very large average radius (3.5 Å), its long lifetime, and the electron detachment cross-section when interacting with molecules N2 and O2.
The findings of that report (an experiment) are consistent with a quantum chemistry model in which it was found that its stable configuration corresponds to a linear molecular exciplex (CH2:H2)− which showed stability in the timescale of hundreds of ps. However, the experiment of 2014 demonstrated stability over the larger timescale of μs, and therefore, perfectly fitted to be detected by standard mass spectrometry techniques.
The mechanism of formation of CH4− is not fully understood. However, it can be elucidated that it may form under high methane density conditions and, probably, a three body collision.
Electron Affinity of Methane
The electron affinity (Eea) of an atom or molecule (A) is the energy difference between the ground state energy of the corresponding neutral species (EA) and the ground state energy of the negative ion (EA−):
In the case of CH4−, dissociation into CH2− + H2 is more likely than releasing the extra electron, therefore, the conventional definition of Eea does not apply to methane. The energy difference between CH4− and CH2− + H2, is 0.85 kcal/mol according to the available theoretical model.
References
Methane
Anions | Negative methane | [
"Physics",
"Chemistry"
] | 880 | [
"Matter",
"Methane",
"Anions",
"Greenhouse gases",
"Ions"
] |
72,828,889 | https://en.wikipedia.org/wiki/Pseudogamma%20function | In mathematics, a pseudogamma function is a function that interpolates the factorial. The gamma function is the most famous solution to the problem of extending the notion of the factorial beyond the positive integers only. However, it is clearly not the only solution, as, for any set of points, an infinite number of curves can be drawn through those points. Such a curve, namely one which interpolates the factorial but is not equal to the gamma function, is known as a pseudogamma function. The two most famous pseudogamma functions are Hadamard's gamma function:
where is the Lerch zeta function. We also have the Luschny factorial:
where denotes the classical gamma function
and denotes the digamma function. Other related pseudo gamma functions are also known.
References
Functions and mappings
Factorial and binomial topics | Pseudogamma function | [
"Mathematics"
] | 177 | [
"Mathematical analysis",
"Functions and mappings",
"Factorial and binomial topics",
"Mathematical analysis stubs",
"Mathematical objects",
"Combinatorics",
"Mathematical relations"
] |
72,831,308 | https://en.wikipedia.org/wiki/Charentese%20amber | Charentese amber is a type of amber that is found in sediments in the Charente-Maritime area of France. It dates to the late Albian to early Cenomanian stages of the mid-Cretaceous, around 100 million years ago. Charentese amber has been known since the early 19th century and was originally referred to as succin, succinic resin, or retinasphalt. The amber is known for its high quality and preservation of inclusions, such as insects, plant debris and other organisms. It is a valuable resource for paleontologists and other scientists studying the biodiversity of ancient ecosystems. The amber is often, but not always, opaque, requiring the usage of X-ray microtomography in order to observe specimens.
Charentese amber has unique geochemical properties such as high content of succinic acid, and a unique ratio of stable isotopes C13/C12, which make it a valuable tool for geochemical and climatic reconstructions of Cretaceous period.
See also
List of types of amber
References
Amber
Nouvelle-Aquitaine
Cretaceous France | Charentese amber | [
"Physics"
] | 220 | [
"Amorphous solids",
"Unsolved problems in physics",
"Amber"
] |
77,249,289 | https://en.wikipedia.org/wiki/Gamithromycin | Gamithromycin, sold under the brand name Zactran, is a veterinary medication used for the treatment of cattle, pigs, and sheep. It is a macrolide antibacterial. It is a 7a-azalide.
It was approved for veterinary use in the European Union in 2008.
Veterinary uses
In the EU, gamithromycin is indicated for the treatment and prevention of bovine respiratory disease in cattle, swine respiratory disease in pigs, and infectious pododermatitis (foot rot) in sheep.
In the US, gamithromycin is indicated for the treatment of bovine respiratory disease in cattle.
References
External links
Veterinary medicine
Tetrahydropyrans
Methoxy compounds
Dimethylamino compounds
Heterocyclic compounds with 1 ring
Nitrogen heterocycles
Polyols
Oxygen heterocycles | Gamithromycin | [
"Chemistry"
] | 175 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
77,249,739 | https://en.wikipedia.org/wiki/Firmness%2C%20commodity%2C%20and%20delight | Firmness, commodity, and delight () are the three aspects of good architecture declared by the Roman architect Vitruvius in his book "De architectura" ("On architecture", 1st century BC) and are also known as Vitruvian virtues, Vitruvian Triad. The literal meaning of the Latin phrase is closer to "durability, convenience, and beauty", but the more familiar version is derived from Henry Wotton's liberal translation of Vitruvius, "The Elements of Architecture" (1624): "Well Building hath three Conditions; Commodity, Firmness, and Delight". The theory of architecture has always been concerned with this interrelated triad of structural integrity, proper use of space, and attractiveness. However, the relative importance of each component varied in time, and new elements had been introduced into the mix from time to time (cf. John Ruskin's "The Seven Lamps of Architecture" that include "sacrifice" and "obedience").
Evolution
The order of words chosen by Vitruvius, with structural integrity coming before the utility, can be explained in two ways. Either the emphasis on firmness was driven by an understanding of architecture as an "art of building", or by the fact that buildings frequently outlive their initial purpose, so "functions, customs, ... and fashions ... are only transitory" (Auguste Perret), and architecture's true impression is in the construction.
While popular again nowadays, the original order of words was modified in 15th century by Leon Battista Alberti who moved the commodity to the first place in the triad. This order was repeated in the 16th century by Andrea Palladio in his "I quattro libri dell'architettura" () which was apparently the source for Wotton's translation.
19th century brought the new materials and construction techniques that allowed architectural forms to be built seemingly defying the laws of gravity, and societal changes that forced a rethinking of proper spatial arrangements. This gave an additional momentum to the idea, first expressed in the late 18th century by Jacques-François Blondel, that beauty ("decoration") is the only worthy aspect of the architectural theory, while the space planning and structural analysis should be left to practitioners (and later, to other disciplines). These considerations had affected teaching of the architectural theory for a long time, but they eventually went out of fashion, and, since the 1960s, the education of architects returned to the synthesis of structural, spatial, and perceptual elements (postmodernism as envisioned by Robert Venturi) or architectural phenomenology of Christian Norberg-Schulz.
Venustas
( "of goddess Venus") carries strong association with the erotic love, so Alberti changed it to ("pleasure") in the 15th century. He also split the beauty into essential , the beauty of proportions, and superficial that only goes skin-deep ("auxiliary brightness"). Much later Le Corbusier held the view that beauty in architecture stems essentially from good mathematical proportions. The distinction between the two sides of beauty was watered down in the early 20th century when ornament started to be thought of as an integral part of the building; both were completely fused together by Bauhaus with its explicit "goal, ... the great building, in which the old dividing-line between monumental and decorative elements would have disappeared for ever" (Walter Gropius, 1935).
After introduction of aesthetics in the 18th century, the emotional impact of the buildings was thought to include not just the beauty, but sublimity, picturesqueness, even ugliness. The latter, for example, was proposed to express in architecture the virtue of manliness.
Utilitas
The purpose of buildings is to provide space for some functions, so the notion of the utility ("commodity") is the least controversial of the triad. The architectural form is influenced by the building's purpose, so frequently "form follows function". However, in many cases it is impossible to predict that proper spatial allocation for the future function and, in the real world, the buildings are often more durable than the need for their original function. When repurposing the building for, say, a social institution, the structure of that institution not infrequently is influenced by the layout of the building, a case of "function follows form". For example, the system of seating used in the UK House of Commons (government and opposition facing each other) has roots in the constraints of its original location, St Stephen's Chapel. French Legislative Assembly was originally seated in the Théâtre des Tuileries with audience addressed by orators. None of the two buildings was built for the democratic debates, instead, they had differently affected the legislative processes in the two countries.
Firmitas
The primacy of structural integrity ("firmness") declared by Vitruvius came under scrutiny in the 20th century. Some theorists are arguing that due to rapid obsolescence of the modern building, the architects should design temporary buildings that are easy to demolish after a few years of use. Since the economic efficiency of such construction are unknown, many practitioners, like Vitruvius, believe in permanency of buildings.
The subject of interplay between the external beauty of the building and its structural system is also a subject of debate. Since the Classic antiquity and until 18th century, the question on whether it is better to provide visual clues to the structural elements underlying an architectural form ("emphasize the structure") or "hide the structure" was considered unimportant, although Alberti in the 15th century recommended the building exterior to reflect the trabeated system regardless of the actual structural elements used. In general, in Italy the construction practice frequently involved building the structure with bricks and then covering it in marble or plaster for appearance, and the architects accepted the independence of the structure and appearance of the forms. In French Île-de-France, with its abundance of high-quality stone that did not need covering, the architectural theory suggested that the structural elements should stay visible. The architects were still expected to manifest the structural integrity of the building in its exterior, creating "apparent stability".
Gothic Revival architecture in the middle of 19th century upended this agreement and stated that flying buttress with its exposed structure is a much better expression of firmitas than the westwork that hides its structural role behind the bulky appearance. The Revivalist architects also declared the need for "truthfulness" in the buildings, both in the use of materials (foreboding the "truth to materials") and the use of structural elements. This new doctrine stimulated the rapid changes in architectural forms in the 20th century, when rapid progress in structural materials (like steel frame) made old architecture forms unusable.
Triad as a slogan
Firmness, commodity, and delight is one of the "great slogans" of architecture, along with form follows function, truth to materials, less is more, emphasize the structure. The triad is listed on the reverse side of the Pritzker Architecture Prize medal.
References
Sources
Architectural theory | Firmness, commodity, and delight | [
"Engineering"
] | 1,464 | [
"Architectural theory",
"Architecture"
] |
77,250,504 | https://en.wikipedia.org/wiki/African%20Adaptation%20Solutions%20Challenge | The African Youth Adaptation Solutions Challenge (YouthADAPT Challenge) is an annual competition and award. It was launched on 6th September 2021 that focuses on youth-led enterprises in Africa working on climate adaptation solutions. It is a collaborative effort between the Global Center on Adaptation, European Union and the Climate Investment Funds under the Africa Adaptation Acceleration Program's YouthADAPT flagship pillar.
The challenge aims to support and highlight innovative ideas and projects developed by young entrepreneurs who addressing climate change challenges and contributing to building resilience in African communities.
In 2021, Akinwumi Adesina, President, African Development Bank presented the awards and it was moderated by Alan Kasujja.
References
Awards established in 2021
2021 establishments in Africa | African Adaptation Solutions Challenge | [
"Technology"
] | 146 | [
"Science and technology awards",
"Science award stubs"
] |
77,250,718 | https://en.wikipedia.org/wiki/UGC%20711 | UGC 711 is a relatively nearby spiral galaxy located in the constellation of Cetus. Estimated to be located 77 million light-years from Earth, the galaxy's luminosity class is IV and it has a HI line width region. It belongs to the equatorial region of Eridanus Void with an arcsec approximation of ≈ 250.
Morphology
UGC 711 is considered a low-surface brightness galaxy (LSB) with a diffuse stellar disk.
With a surface brightness measurement found ~1 magnitude less illuminated compared to μ B,0 = 21.65 mag arcsec−2 according to K.C. Freeman, UGC 711 is one of best studied superthin galaxies defined by its atypical classification when seen edge-on. It has a flat structure with only a diameter estimating to be a = 40 arcsecs but has a major-to-minor axis ratio wider than 7 arcsecs.
The rotational velocity of UGC 711 is said to be only Vcirc = 92 km s−1 according to measurements from Hyperleda.
References
Cetus
Spiral galaxies
00711
Low surface brightness galaxies
+00-04-008
004063 | UGC 711 | [
"Astronomy"
] | 242 | [
"Cetus",
"Constellations"
] |
77,250,898 | https://en.wikipedia.org/wiki/Testsigma | Testsigma is a low-code, AI-driven automated testing platform for software testing, CI/CD, and agile teams. It provides testing products and solutions for web, mobile, and API applications and can be integrated with popular CI/CD tools.
About
Testsigma was founded by Rukmangada Kandyala in 2019. Testsigma has multiple products to let software testing teams test web apps, mobile apps, APIs and ERP applications like Salesforce.
Testsigma claims Nagra, Samsung, Cisco, Bosch, NTUC Fairprice as customers.
Funding
In 2022 Testsigma raised $4.6 Million in funding led by Accel and Strive. In June 2024 Testsigma raised $8.2M led by MassMutual Ventures.
Products
Testsigma offers many continuous testing capabilities as part of its cloud testing platform, including:
Mobile Testing
API Testing
Web Testing
Salesforce testing
References
External links
Official website
Cloud computing providers
Cloud computing
Software testing
Natural language processing | Testsigma | [
"Technology",
"Engineering"
] | 205 | [
"Software engineering",
"Natural language processing",
"Natural language and computing",
"Software testing"
] |
77,251,633 | https://en.wikipedia.org/wiki/Oryon | Oryon is an 8 to 12-core CPU implementing the ARMv8.7-A architecture featuring a custom microarchitecture designed by Qualcomm. It is used on the Snapdragon X Plus, Snapdragon X Elite and Snapdragon 8 Elite systems on chips, first released in June 2024.
It began development in 2021 when Nuvia was acquired by Qualcomm.
It is the first custom microarchitecture for smartphone SoCs released by Qualcomm since the original Kryo.
Models
1st generation
Development of the first generation of Oryon started in 2021 under Nuvia. This generation consists of Snapdragon X-series chips that are targeted at laptops.
2nd generation
The second generation consists only out of Snapdragon 8-series chips targeted at smartphones and tablets.
References
ARM processors
Qualcomm IP cores | Oryon | [
"Technology"
] | 181 | [
"Computing stubs",
"Computer hardware stubs"
] |
77,252,169 | https://en.wikipedia.org/wiki/Balanegra%20Aquifer | Balanegra Aquifer is an aquifer on a coastal plain in southern Spain. It lies in an area of dolomite rock. The aquifer have had problems of saltwater intrusion due to overexploitation but some areas are more protected from seawater intrusions than others since sediments of Neogene age locally separates dolomite from seawater.
References
Aquifers | Balanegra Aquifer | [
"Environmental_science"
] | 83 | [
"Hydrology",
"Aquifers"
] |
77,252,364 | https://en.wikipedia.org/wiki/2024%20Virudhunagar%20explosions | On 17 February 2024, a fire broke out following an explosion at a firecracker factory in Virudhunagar district, Tamil Nadu. Ten people were killed and more than seven were injured. On 29 June 2024, another explosion at a different fire cracker unit near Sattur, resulted in four deaths and one injury.
Background
Virudhunagar district is a major centre for fire cracker with nearly 90% of the fire cracker production of the country manufactured here. The firecracker units are located in rural areas, employ cheap local labour and often do not follow safety norms. Several accidents have been reported due to mishandling of chemicals and poor safety norms.
Incidents
At 12:30 IST 17 February 2024, an explosion at a fire cracker manufacturing unit at Ramuthevanpatti village in Virudhunagar district, Tamil Nadu. The factory was involved in the production of fire crackers and the inflammable chemicals, resulted in a fire and further explosions. The fire started in the chemical mixing room and spread to nearby areas, resulting in the explosion. Ten people were killed and more than seven were injured in the accident. On 29 June 2024, a similar explosion at a fire cracker unit near Sattur resulted in a fire, that killed four people and injured one. The fire started when chemicals used in the manufacture ignited.
Aftermath
National Disaster Response Force (NDRF), Tamil Nadu Disaster Response Force (TNDRF) and Tamil Nadu Fire and Rescue Services were involved in fire control, search and rescue operations. The injured were rescued and treated in nearby hospitals. Chief Minister of Tamil Nadu M. K. Stalin announced an ex-gratia of for the next of the kin who were killed.
References
2024 disasters in India
Disasters in Tamil Nadu
February 2024 events in India
June 2024 events in India
Fireworks accidents and incidents in India
Chemical disasters
Explosions in 2024
2024 industrial disasters
2020s in Tamil Nadu
2024 fires in Asia | 2024 Virudhunagar explosions | [
"Chemistry"
] | 407 | [
"Chemical accident",
"Chemical disasters"
] |
77,253,313 | https://en.wikipedia.org/wiki/Game%20form | In game theory and related fields, a game form, game frame, ruleset, or outcome function is the set of rules that govern a game and determine its outcome based on each player's choices. A game form differs from a game in that it does not stipulate the utilities or payoffs for each agent.
Mathematically, a game form can be defined as a mapping going from an action space—which describes all the possible moves a player can make—to an outcome space. The action space is also often called a message space when the actions consist of providing information about beliefs or preferences, in which case it is called a direct mechanism. For example, an electoral system is a game form mapping a message space consisting of ballots to a winning candidate (the outcome). Similarly, an auction is a game form that takes each bidder's price and maps them to both a winner and a set of payments by the bidders.
Often, a game form is a set of rules or institutions designed to implement some normative goal (called a social choice function), by motivating agents to act in a particular way through an appropriate choice of incentives. Then, the game form is called an implementation or mechanism. This approach is widely used in the study of auctions and electoral systems.
The social choice function represents the desired outcome or goal of the game, such as maximizing social welfare or achieving a fair allocation of resources. The mechanism designer's task is to design the game form in such a way that when each player plays their best response (i.e. behaves strategically), the resulting equilibrium implements the desired social choice function.
References
Game theory
Mechanism design
Social choice theory | Game form | [
"Mathematics"
] | 344 | [
"Game theory",
"Mechanism design"
] |
77,256,290 | https://en.wikipedia.org/wiki/Stef%20Tijs | Stef Tijs (August 31, 1937 – June 13, 2023), or Stephanus Hendrikus Tjis was a Dutch mathematician and a game theory pioneer in the Netherlands. He contributed to most subfields in game theory and particularly in cooperative game theory, where he introduced the Tijs value (later known as the τ value) in 1981 as a solution to n-person games alternative to the Shapley value and others.
Education and career
Tijs was born in Ginneken en Bavel. He studied at Utrecht University for a bachelor's degree in chemistry from 1954 to 1959, later he switched to mathematics, obtaining a MSc degree at the same university in 1963. Tijs was a research assistant in mathematics at Radboud University Nijmegen from 1963 to 1969 and an assistant professor in mathematics there from 1969. He received his PhD in mathematics for work on matrix games from the Radboud University Nijmegen under the supervision of Arnoud van Rooij and Freddy Delbaen (who was younger than Tijs) in 1975. He became an associate professor at Nijmegen in 1975 and gradually built up a Dutch school of game theory there with an international outlook. In 1982, Tijs initiated the game theory seminar in Nijmegen, which later prompted the Netherlands to join the European Meeting on Game Theory (also called SING) that is held annually from 2000. Tijs was promoted to full professor at Radboud University Nijmegen in 1985. In 1991, he moved to Tilburg University, where he became a professor at the Department of Econometrics and Operations Research and the Center of Economic Research. He stayed for the remainder of his career. Between 2003 and 2005, Tijs was also a professor of mathematics at University of Genoa in Italy.
Tijs received a honorary doctorate from the Miguel Hernández University of Elche in 2000. He was a fellow and a council member of the Game Theory Society. He became a Knight of the Order of the Netherlands Lion in 2003.
Bibliography
References
1937 births
2023 deaths
People from North Brabant
Game theorists
20th-century Dutch mathematicians
Utrecht University alumni
Radboud University Nijmegen alumni
Academic staff of Radboud University Nijmegen
Academic staff of Tilburg University
Knights of the Order of the Netherlands Lion
Academic staff of the University of Genoa | Stef Tijs | [
"Mathematics"
] | 479 | [
"Game theorists",
"Game theory"
] |
77,257,429 | https://en.wikipedia.org/wiki/Taipei-1%20%28supercomputer%29 | Taipei-1 is a supercomputer in Taiwan Kaohsiung Software Park owned by Nvidia. Taipei-1 is ranked 38th in the TOP500 released in June 2024.
Taipei-1 supercomputer 25% of its computing power will be allocated to academia and 75% for commercial use.
Technical specifications
Cores: 40,960
Linpack performance: 22.30 PFlop/s
Theoretical peak: 34.53 PFlop/s
References
See also
Semiconductor industry in Taiwan
Taiwania (supercomputer)
2023 establishments in Taiwan
Computer-related introductions in 2023
Science and technology in Taiwan
Supercomputers | Taipei-1 (supercomputer) | [
"Technology"
] | 132 | [
"Supercomputers",
"Supercomputing"
] |
77,259,262 | https://en.wikipedia.org/wiki/Career%20cushioning | In human resources, career cushioning refers to employees who discreetly upskill and network as a contingency plan in the event of job loss.
Career cushioning may involved getting certifications, expanding professional networks, updating resumes and profiles, and discretely applying to alternative jobs. The proactive approach provides a sense of security during uncertain economic times. Employers can combat career cushioning by improving their market competitiveness.
The term came to prominence in 2022 following the COVID-19 pandemic layoffs and stems from cushioning in dating, where partners have a backup plan and cushioning a fall.
References
Labor relations
2022 neologisms
Popular culture neologisms
Human resource management
Occupational stress
Motivation
Work
Labor | Career cushioning | [
"Biology"
] | 147 | [
"Ethology",
"Behavior",
"Motivation",
"Human behavior"
] |
77,260,009 | https://en.wikipedia.org/wiki/Job%20cuffing | In human resources, job cuffing refers to the reluctance of employees to leave an employer, typically due to economic uncertainty. Job cuffing typically occurs in the winter in the hopes that employment prospects will improve in the spring. Remote employees are less resistant to return to the office during job cuffing.
Job cuffing can negatively impact productivity as disengaged employees continue to work while waiting to resume the job search. Employers can counter job cuffing by improving their employee value proposition.
The term stems from cuffing season and being handcuffed to one's job.
References
Labor relations
2022 neologisms
Popular culture neologisms
Human resource management
Occupational stress
Motivation
Work
Labor | Job cuffing | [
"Biology"
] | 137 | [
"Ethology",
"Behavior",
"Motivation",
"Human behavior"
] |
78,617,944 | https://en.wikipedia.org/wiki/Flazalone | Flazalone is an anti-inflammatory drug that has not been approved as a medicine.
According to Shaomeng Wang and co-workers, replacement of the para-fluoro halogen with a meta,para-dichloro substitution resulted in dopamine reuptake inhibitors useful in treating cocaine addiction.
References
Ketones
Tertiary alcohols
Nonsteroidal anti-inflammatory drugs
Piperidines
4-Fluorophenyl compounds | Flazalone | [
"Chemistry"
] | 92 | [
"Pharmacology",
"Ketones",
"Functional groups",
"Medicinal chemistry stubs",
"Pharmacology stubs"
] |
78,619,897 | https://en.wikipedia.org/wiki/Capronia%20normandinae | Capronia normandinae is a species of lichenicolous (lichen-dwelling) fungus in the family Herpotrichiellaceae. The fungus was first formally described in 1990 by Rolf Santesson and David Hawksworth. The fungus has been recorded from Papua New Guinea, the Atlantic Ocean (Portugal, Madeira), Australasia (New Zealand), Europe (France, Ireland, Norway, Portugal, Spain, UK), and South America (Argentina, Chile, Colombia, Ecuador). The fungus parasitises the host lichen Normandina pulchella, after which it is named.
A characteristic feature of Capronia normandinae is the black, hair-like structures on its surface called setose perithecia. The fungus produces light olive-brown ascospores typically measuring 15–21 by 7.5–9.0 μm. These spores look like they have many internal divisions because they contain tiny fat droplets () and special cell walls (distosepta). Around the fungus's opening (the ostiole), there are simple (unbranched), unsegmented hair-like growths (setae).
References
Eurotiomycetes
Fungus species
Fungi described in 1990
Lichenicolous fungi
Fungi of New Guinea
Fungi of Europe
Fungi of New Zealand
Fungi of South America
Taxa named by Rolf Santesson
Taxa named by David Leslie Hawksworth | Capronia normandinae | [
"Biology"
] | 291 | [
"Fungi",
"Fungus species"
] |
78,620,367 | https://en.wikipedia.org/wiki/Bakuya%20Kofun | is a burial mound, located in the Umamikita neighborhood of the town of Kōryō, Nara Prefecture in the Kansai region of Japan. The tumulus was designated a National Historic Site of Japan in 1983. It is one of the burial mounds that make up the Umami Kofun cluster.
Overview
The Bakuya Kofun is a -style circular burial mound built on the tip of a small ridge in the center of the Umami Hills in western Nara Prefecture. The mound measures 48 to 60 meters in diameter and is 13 meters high. The burial mound is built in three tiers, but only the top tier (the third tier) is completely circular due to the tiering. Although fragments of haniwa clay figurines have been found on the outside of the mound, none remain in their original position, and it is assumed that they were taken from other kofun for the purpose of dressing up the outside of the mound. The burial facility is a double-sided horizontal-entry stone burial chamber with an opening facing south. It is one of the largest stone chambers in Nara Prefecture, measuring 17.1 meters in total length. The stone used is huge granite monoliths, although the Umami Hills are clay mountains that produce no stone, but the largest stone weighs nearly 60 tons, making it the second largest in Nara Prefecture after the ceiling stone of the Ishibutai Kofun. Inside the burial chamber were one hollowed-out house-shaped stone coffin and one combined house-shaped stone coffin (not extant) are placed inside the chamber. Both stone coffins have been extensively damaged by robbers; however in archaeological excavations starting in 1983, over 20,000 items of grave goods were found in the ground around the stone coffins and in the passageways. Among the ornaments excavated were gold rings and various beads (gilt bronze gardenia beads, small glass beads, and millet beads), while horse equipment included two sets of gilt bronze-plated stirrups made of iron, a fence with metal rims, a heart-shaped mirror panel, and apricot leaves. Weapons included a silver-plated iron sword and nearly 400 iron arrowheads, and among the containers concentrated in the passageway was a gilt bronze-plated wooden container and 58 pieces of Sue ware pottery, which indicate that the tomb was built between the second half and the end of the 6th century, during the late Kofun period.
It is one of the few burial mounds in the Umami Kofun Group that has a horizontal entry burial chamber. The identity of the buried person is uncertain, but from the size of the mound, the size of the burial chamber, and the abundance of grave goods the most likely theory is that this is the grave of Prince Osasakahikohito, eldest son of Emperor Bidatsu. Currently, the site has been developed as Bakuya Historical Site Park, and access to the burial chamber is restricted, but it is open to the public for a certain period of the year. It is approximately three kilometers northeast of Kashiba Station on the JR West Wakayama Line.
See also
List of Historic Sites of Japan (Nara)
References
External links
Nara Prefectural Library
Kashihara Institute of Archaeology home page
Kōryō Town home page
History of Nara Prefecture
Historic Sites of Japan
Round Kofun
Kōryō, Nara
Architecture | Bakuya Kofun | [
"Engineering"
] | 694 | [
"Construction",
"Architecture"
] |
78,620,422 | https://en.wikipedia.org/wiki/Jet%20disrupter | In mass spectrometry, jet disrupters are specialized electrodes within ion funnels that counteract the effects of directed gas flow. Acting as physical barriers to neutral molecules, they disperse gas molecules and charged droplets while improving ion transmission and reducing vacuum system demands.
Development and functionality
The development of the jet disrupter stemmed from the discovery that directed gas flow continued beyond both the capillary inlet and the ion funnel exit. This persistence caused inaccurate pressure readings, contamination of mass spectrometer components, increased background noise, and placed greater demand on downstream vacuum pumps. To address these challenges posed by non-uniform gas pressures within ion funnels, the jet disrupter was introduced.
The first jet disrupter was developed by Taeman Kim, consisting of a 9-mm brass disk positioned 22 mm downstream of the first ion funnel electrode. Operating at a higher voltage than the adjacent ring electrodes, this configuration enabled ions to be deflected around the electrode while causing neutral molecules and charged droplets to disperse and more efficiently be removed by vacuum pumps. Implementation of the jet disrupter in ion funnels yielded several improvements: downstream vacuum chamber pressure was reduced by a factor of 2-3, ion transmission improved by 15%, and MS/MS spectra demonstrated enhanced signal-to-noise ratios, increasing between 5.3 and 14.1-fold (depending on sample concentrations).
Furthermore, jet disrupters can function as ion valves. By modulating the applied voltage, it is possible to control the transmission efficiency of ions through the funnel. This capability is particularly valuable for reducing the relative intensity of highly abundant analyte ions, which can rapidly fill ion trap analyzers and cause unwanted space charging effects, which occur when excessive ion populations degrade mass analyzer performance. Their application into ion cyclotron resonance (ICR) cells helped maintain optimal ion populations, improving mass accuracy and sensitivity. The valve-like properties have also proven beneficial in dual-channel ion funnel designs, where a jet disrupter can modulate the flow of ions from one channel without affecting the ion transmission efficiency of the other.
Problems and alternative technologies
While jet disrupters effectively manage directed gas flow and improve ion transmission, they face several operational challenges. Over time, the electrode surface becomes contaminated through exposure to liquid droplets and neutral molecules. Moreover, since jet disrupters cannot completely block these particles, some inevitably pass through to downstream components of the mass spectrometer, gradually degrading signal quality and necessitating periodic maintenance or cleaning.
An alternative approach involves orthogonal ion injection, where the capillary input is orthogonally aligned with the ion funnel axis. Instead of using a physical barrier like a jet disrupter, this configuration allows the ion funnel to capture ions while naturally directing gas flow toward an outlet away from the funnel. This design effectively separates the gas dynamics from the ion path while maintaining ion transmission.
References
Ions | Jet disrupter | [
"Physics",
"Chemistry"
] | 581 | [
"Ions",
"Matter"
] |
78,621,414 | https://en.wikipedia.org/wiki/HD%20123 | HD 123 is a hierarchical triple star system in the deep northern constellation of Cassiopeia. It consists of a visual binary between HD 123A and B, of which component B is itself a spectroscopic binary (Ba & Bb). Through the use of a telescope, the visual pair can be resolved, with a separation that varies between 0.5 and 1.6 arcseconds. With a combined apparent magnitude of 5.98, it is faintly visible to the naked eye under dark skies as a yellow-hued star. The system is located approximately distant according to Hipparcos parallax measurements, while the Gaia EDR3 parallaxes for the individual stars point towards slightly closer distances of and , respectively. It is trending closer towards the Solar System at a heliocentric radial velocity of −13.79 km/s.
Designation
Its name, HD 123, denotes that it is the 123rd object in the Henry Draper Catalogue, included within the first volume published in 1918. Alternate designations include HR 5, ADS 61, as well as the variable-star designation V640 Cassiopeiae, which was given in 1985 after it was reported to fluctuate in brightness with a one-day period in 1983, but this was refuted in 1999 as the star was shown to be constant.
Properties
The visible components, A and Ba, are both G-type main-sequence stars like the Sun but slightly less massive, A being the brighter, hotter, and more massive of the two. Weber & Strassmeier (1998) assumed a radius of 0.87 for B, corresponding to a typical late G-type star. One of the G stars exhibit high chromospheric activity while the other is quiescent, an oddity seen in some other solar-like binaries such as HD 137763/HD 137778, 37 Ceti, and Zeta Reticuli. Bb, on the other hand, is thought to be a red dwarf, having approximately three-tenths the mass of the Sun.
The A and B components have an orbital period of 106.83 years spaced about 30 AU apart, while B itself consists of the pair Ba/Bb, which revolve around each other every 47.685 days in an eccentric orbit (eccentricity 0.610).
Observational history
On 25 May 1782, astronomer William Herschel discovered that HD 123 was a double star, which he designated H I 39. He remarked that the two stars appeared "red," referring to a late spectral type in modern terms. F. G. W. Struve was the second to observe the object from the 1820s through the 1830s, correctly noting that the stars bore a yellowish hue. Owing to the rapidly shifting position angle, a solution for the visual orbit was calculated as early as 1841, and had been refined to near-modern values by 1867, with an obtained period of 106.83 years and an eccentricity of ~0.45. The large proper motion of the star was noticed in 1869, which, even then, was seen as an indication of its relatively close distance from Earth. However, it took until the 1960s for a solid consensus to emerge on its parallax, which was determined to be close to 0.050 arcseconds.
Multiplicity of HR 5B
The possibility that HR 5 may be composed of more than two stars was raised by several authors such as Volet (1937), who suggested a 22-year secondary orbital period (though admitted it was unconvincing), and Dorrit Hoffleit, who noted in the 1982 edition of the Bright Star Catalogue that a 6.9-year period companion to B may exist. In 1951, H. Roth argued that component B was multiple, since the mass ratio indicated that B was apparently more massive despite being fainter. This was followed up by Lippincott (1963), refining the ratio MB/(MA+MB) to 0.546 ± 0.006, which meant B was about 20% more massive than A. This has been used in subsequent studies, such as Griffin (1999) who derived a total mass of the Ba/Bb pair of 1.17 .
Alleged variability
In 1983, Brettman et al. reported that HR 5 was a variable star with a period of 1.082 ± 0.002 days. They were unable to distinguish which of the visible components displayed this variability, but theorized that one of them could be either a rapidly rotating star with unevenly distributed starspots, or a spectroscopic binary with a 1.082-day period. Weber & Strassmeier (1998) additionally found radial velocity variations in HR 5B with a period of 1.026 days, and reasoned that Ba must be the variable component. In 1999, however, a comprehensive study by Griffin showed that the star exhibited no signs of photometric variability and that while the radial velocity variations of component B did exist, the reported one-day period was an alias of the true period of 47.685 days. The AAVSO lists HD 123 as a reflection variable (a binary system in which brightness variations are seen because one component reflects light from the other) with the small brightness range of magnitude 5.966 to 5.981.
Footnotes
References
G-type main-sequence stars
M-type main-sequence stars
Triple star systems
Cassiopeia (constellation)
Cassiopeiae, V640
000123
BD+57 02865
J00061575+5826128
000518
0005 | HD 123 | [
"Astronomy"
] | 1,153 | [
"Cassiopeia (constellation)",
"Constellations"
] |
78,621,642 | https://en.wikipedia.org/wiki/NNC2215 | NNC2215 is a bioengineered glucose-sensitive insulin. The drug is designed by a team of Novo Nordisk researchers.
NNC2215 can sense the glucose concentration presence in blood. The protein's sensitivity is reduced when low concentration of glucose, thus reducing the risk of hypoglycemia. In addition, it can effectively cover the risk of fluctuations of blood sugar levels.
The study was published on scientific journal Nature on October 16, 2024. This study demonstrated the ability of protein engineering in future medicine and a major advancement in treatment capabilities.
History
A glucose sensitive treatment method for diabetes have long been pursued by science since 1979. Such protein is expected to solve the problem of fluctuations of blood sugar levels. For diabetes patients, skipping meal alone could lead to hypoglycemia, which is a common complication could cause loss of consciousness or seizures.
There are several attempts to create such a medicine with various levels of success.
See also
Diabetes
Hyperglycemia
Hypoglycemia
References
Insulin receptor agonists | NNC2215 | [
"Chemistry"
] | 215 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
78,622,117 | https://en.wikipedia.org/wiki/Valerii%20Kublanovskyi | Valerii Semenovych Kublanovskyi (born 17 December 1936) is a Ukrainian electrochemist, Doctor of Chemical Sciences (1981), professor (1988), laureate of the National Prize of Ukraine named after Borys Paton (2021).
Biography
Kublanovskyi graduated from Odesa University in 1959. After graduation, he worked in Odesa at the Black Sea Shipping Company. In 1960-1961, he worked at the Odesa Hydrobiological Station of the Institute of Hydrobiology of the Academy of Sciences of the Ukrainian SSR. Since 1962, he has been working in Kyiv at the Institute of General and Inorganic Chemistry named after V. I. Vernadsky of National Academy of Sciences of Ukraine, where since 1983 he has held the position of Head of the Department of Electrochemical Materials Science and Electrocatalysis.
Researcher
His research focuses on the theory of electrode processes, electrochemical mass transfer, electrochemistry of coordination compounds, chemical current sources, electrocatalysis, theoretical and applied electroplating, and electrochemical ecology.
He is a member of the Academic Council of the Interdepartmental Department of Electrochemical Energy of the National Academy of Sciences of Ukraine, a member of the Academic Council of the Vernadsky Institute of General and Inorganic Chemistry of the National Academy of Sciences of Ukraine, member of the editorial board of the Ukrainian Chemical Journal].
Awards
Prize of the National Academy of Sciences of Ukraine named after A. I. Brodsky — for the series of works “Structure and reactivity of metal coordination compounds in electrodeposition and electrocatalysis” (2018)
National Prize of Ukraine named after Borys Paton — for the work “Electrochemistry of functional materials and systems” (2021)
Works
Among his main works:
Concentration changes in the near-electrode layers during electrolysis. Kyiv, 1978 (co-authored);
Pulse electrolysis. Kyiv, 1990 (co-author);
Mechanism of electrode reactions of coordination compounds // UHZh. 1993. No. 5;
Pulse electrolysis of alloys. Kyiv, 1996 (co-authored);
Scientific achievements and directions of work in the field of electrochemistry of aqueous solutions // UHZh. 2004. No. 7;
Sanitary-microbiological and hygienic assessment of water media treated with cold plasma. Dnipro, 2009 (co-authored);
Electrochemistry in Ukraine // Bulletin of the National Technical University “Kharkiv Polytechnic Institute”. 2010. No. 3.Серед основних праць:
References
External links
Kublanovskyi Valerii Semenovych // Encyclopedia of Modern Ukraine [Electronic resource] / Eds. Zhukovsky, M. Zheleznyak [and others] ; NAS of Ukraine, National Academy of Sciences of Ukraine, National Technical School of Ukraine.- Kyiv : Institute of Encyclopedic Research of the National Academy of Sciences of Ukraine, 2014.- Access mode : https://esu.com.ua/article-535. - Last updated: 2022
1936 births
Electrochemists
Ukrainian chemists
Living people
Odesa University alumni
People from Odesa | Valerii Kublanovskyi | [
"Chemistry"
] | 664 | [
"Electrochemistry",
"Electrochemists"
] |
78,623,224 | https://en.wikipedia.org/wiki/Vamicamide | Vamicamide, also known as FK-176 or Urocut, is a muscarinic acetylcholine receptor (mAChR) antagonist that was developed by Fujisawa (now part of Astellas Pharma) for the treatment of urinary incontinence and overactive bladder. This small molecule drug acts by blocking muscarinic receptors, which play a role in bladder function. Despite showing promise in preclinical studies for increasing bladder capacity without affecting other urinary parameters, vamicamide has never been approved for medical use. The drug's development was ultimately discontinued, with its highest research and development status reaching the New Drug Application (NDA) phase in Japan.
References
Muscarinic antagonists
Amides
Dimethylamino compounds
2-Pyridyl compounds
Abandoned drugs | Vamicamide | [
"Chemistry"
] | 175 | [
"Functional groups",
"Amides",
"Drug safety",
"Abandoned drugs"
] |
78,623,554 | https://en.wikipedia.org/wiki/RO5203648 | RO5203648 is a trace amine-associated receptor 1 (TAAR1) partial agonist. It is a potent and highly selective partial agonist of both rodent and primate TAAR1. The drug suppresses the effects of psychostimulants like cocaine and methamphetamine. It also produces a variety of other behavioral effects, such as antidepressant-like, antipsychotic-like, and antiaddictive effects. Research with RO5203648 has led to interest in TAAR1 agonists for potential treatment of drug addiction. RO5203648 itself was not developed for potential medical use due to poor expected human pharmacokinetics.
Pharmacology
Pharmacodynamics
Actions
RO5203648 binds to the mouse, rat, cynomolgus monkey, and human TAAR1 all with high affinity (Ki = 0.5–6.8nM). It is a potent partial agonist in all species ( = 4.0 to 31nM), with an efficacy of 48 to 73% relative to the endogenous TAAR1 agonists β-phenethylamine and tyramine and the TAAR1 full agonist RO5166017. RO5203648 is highly selective for the TAAR1, showing ≥130-fold selectivity for the mouse TAAR1 over 149other targets.
Effects
RO5203648 has been found to increase the firing rate of ventral tegmental area (VTA) dopaminergic neurons and dorsal raphe nucleus (DRN) serotonergic neurons in mouse brain slices ex vivo. This is in contrast to the TAAR1 full agonist RO5166017, which suppresses their firing rates, but is analogous to the TAAR1 antagonist EPPTB, which dramatically increases their firing rates. RO5203648 failed to show these effects in the neurons of TAAR1 knockout mice, indicating that its actions are mediated by interactions with the TAAR1. RO5203648 alone does not affect electrically evoked dopamine release or reuptake (as measured by tau) in rat nucleus accumbens (NAc) slices ex vivo. Conversely, RO5203648 prevented cocaine-induced dopamine elevations in this system without affecting the dopamine reuptake inhibition of cocaine. As such, its inhibition of cocaine's dopaminergic actions is likely to be independent of dopamine transporter (DAT) interactions. RO5203648 did not affect methamphetamine-induced dopamine efflux or reuptake inhibition in rat striatal synaptosomes in vitro. However, RO5203648 blunted and delayed methamphetamine-induced dopamine elevations in the NAc in rodents in vivo. Hence, as with cocaine, RO5203648's regulation of methamphetamine's actions appears to be independent of DAT interactions.
Some in-vitro studies have suggested that TAAR1 agonism by amphetamines and β-phenethylamine may mediate induction of monoamine release and reuptake inhibition by these agents. However, a subsequent study failed to replicate these findings under similar conditions. In addition, as previously described, RO5203648 did not affect methamphetamine-induced dopamine release and reuptake inhibition in synaptosomes in vitro. The dopamine elevations and psychostimulant-like effects of amphetamines are not only preserved but are actually augmented in TAAR1 knockout mice in vivo. Concordant in-vivo findings have been made with amphetamines combined with TAAR1 agonists and antagonists as well as with TAAR1 overexpression. It appears that TAAR1 agonism by amphetamines, such as amphetamine, methamphetamine, and MDMA, auto-inhibits their monoaminergic effects. Conversely, most cathinones lack TAAR1 agonism, and this might enhance their effects compared to amphetamines.
RO5203648 does not significantly affect basal locomotion. Conversely, the drug has been found to dose-dependently suppress cocaine-induced hyperlocomotion in mice and rats, whereas it only suppressed dextroamphetamine-induced hyperactivity at a high dose in rats and did not affect dextroamphetamine-induced hyperlocomotion in mice. RO5203648 reduced early but potentiated late hyperlocomotion induced by methamphetamine. With chronic administration of RO5203648 and methamphetamine, RO5203648 dose-dependently and progressively decreased methamphetamine-induced hyperlocomotion. TAAR1 full agonists like RO5166017 and RO5256390 also suppress psychostimulant-induced hyperlocomotion. RO5203648 suppressed spontaneous hyperactivity in a novel environment in dopamine transporter (DAT) knockout mice, similarly to antipsychotics like haloperidol and olanzapine. RO5203648 has also been found to suppress hyperlocomotion induced by the NMDA receptor antagonist L-687,414 or in genetically modified mice with a hypoactive NMDA receptor. The effects of RO5203648 on hyperdopaminergic- and hypoglutamatergic-mediated hyperlocomotion are similar to those of the TAAR1 full agonist RO5166017.
The drug has shown anti-cataleptic, pro-cognitive, antipsychotic-like, antidepressant-like, anxiolytic-like, anti-addictive, and wakefulness-promoting effects in animals. RO5203648, as well as the TAAR1 full agonist RO5256390, have been found to suppress cocaine and methamphetamine self-administration, and hence presumably their rewarding and reinforcing effects. RO5203648 also blocked methamphetamine-induced locomotor sensitization, but cross-sensitized with methamphetamine at the highest dose. RO5203648 by itself is not self-administered in animals, suggesting that it lacks reinforcing effects and misuse liability of its own.
Pharmacokinetics
RO5203648 showed favorable pharmacokinetics orally and intravenously in mice, rats, and monkeys. However, it was found to be very rapidly metabolized in human hepatocytes in vitro.
Chemistry
In terms of chemical structure, RO5203648 is a 2-aminooxazoline derivative. This group also includes a number of other selective TAAR1 ligands, including the near-full agonist RO5166017, the full agonist RO5256390, and the partial agonist RO5263397. RO5203648 is also very closely structurally related to the monoamine releasing agents and psychostimulants aminorex and clominorex.
History
RO5203648 was first described by 2012. It was the first selective TAAR1 partial agonist to be developed. The drug followed the first TAAR1 antagonist EPPTB and the first TAAR1 full agonist RO5166017. It was under investigation for potential clinical use in humans, but showed indication of very rapid human metabolism in vitro. As a result, it was deselected from development, and other compounds, such as the TAAR1 partial agonist RO5263397, were pursued instead.
See also
RO5073012 – TAAR1 weak partial agonist
RO5166017 – TAAR1 partial or full agonist
RO5256390 – TAAR1 partial or full agonist
RO5263397 – TAAR1 partial agonist
EPPTB – TAAR1 antagonist/inverse agonist
References
Amines
Chloroarenes
Oxazolines
TAAR1 agonists
TAAR1 antagonists | RO5203648 | [
"Chemistry"
] | 1,716 | [
"Amines",
"Bases (chemistry)",
"Functional groups"
] |
78,623,990 | https://en.wikipedia.org/wiki/GAARlandia | The Greater Antilles + Aves Ridge, also known as GAARlandia, is a hypothesized land bridge which is proposed to have connected the Greater Antilles to South America around 33 million years ago (mya). Animal and plant species are thought to have colonized the Caribbean Islands through dispersal and vicariance, and the most prominent vicariance hypothesis involves colonization via GAARlandia. Proponents of the hypothesis cite studies of individual lineages, while critics point to a lack of geological evidence.
Hypothesis
The GAARlandia hypothesis was introduced by Ross MacPhee and Manuel Iturralde-Vinent in 1994. It posits that the North American and South American plates compressed the Caribbean plate for 2 million years during the Eocene–Oligocene boundary (33 million years ago), which led the presently-submerged Aves Ridge in the eastern Caribbean Sea to rise and connect South America with Puerto Rico via an unbroken land bridge; Puerto Rico is posited to have been further connected via dry land to Hispaniola, Cuba and eastern Jamaica. During this period the ice sheet expanded on Antarctica, causing the global sea level to drop. MacPhee and Iturralde-Vinent proposed that the ancestors of the non-flying land vertebrates that inhabit, or used to inhabit, the Greater Antilles arrived from South America by walking along this bridge rather than through oceanic dispersal.
Debate
The GAARlandia hypothesis is controversial in the scientific community. It has been supported by studies of individual lineages, but simultaneous colonization by multiple lineages is yet to be proven. Alonso et al. (2011) firmly argued in favor of the hypothesis: they found out in a phylogenetic research that the common ancestor of the toads of the genus Peltophryne, which do not tolerate saltwater, arrived on the Greater Antilles 33 million years ago–exactly when GAARlandia is supposed to have connected the present-day islands to South America. Other taxa found to have arrived at the time GAARlandia is said to have existed include cichlids, Eleutherodactylus and Osteopilus frogs, butterflies, Polistinae wasps, spiders with limited dispersal ability, extinct primates and Megalocnidae sloths, multiple bat groups, and hystricognath rodents.
Ali & Hedges (2021) have found "weak and non-existent" support for GAARlandia, respectively, in the colonization record of land vertebrates and the geological and seismic data. They conclude that oceanic dispersal is "the best available explanation" for the origin of all Greater Antillean species, including plants and invertebrates.
Weaver et al. posit that GAARlandia might have enabled Limia, freshwater fish endemic to the islands, to reach the Antilles through a combination of dispersal, vicariance, and island hopping. Weaver et al. note, however, limias and all other native Antillean species are tolerant of saltwater, and conclude that intolerant species (such as primary division freshwater fish and caecilians) would have colonized the islands as well if a land bridge had been sufficient. Weaver et al. note that mammals which may have walked across GAARlandia, including megalonychid sloths, were capable of crossing short stretches of saltwater as well.
References
Biological hypotheses
Former landforms
Eocene South America
Oligocene South America
Natural history of the Greater Antilles
Natural history of South America
Biology controversies
Eocene Caribbean
Oligocene Caribbean | GAARlandia | [
"Biology"
] | 710 | [
"Biological hypotheses"
] |
78,624,574 | https://en.wikipedia.org/wiki/ZTF%20J0328-1219 | ZTF J032833.52−121945.27 (also called ZTF J0328-1219) is a white dwarf with two transiting debris clouds around it.
ZTF J0328-1219 was first discovered as a white dwarf with Gaia and the virtual observatory in 2018. At the time it was known by its Gaia identification number. In 2021 it was discovered that this white dwarf has transiting debris around it. This was discovered with the Zwicky Transient Facility (ZTF) and follow-up photometry with the McDonald Observatory. It was also shown with spectroscopy from the Lowell Discovery Telescope (LDT) that the white dwarf has deep calcium absorption lines.
A more detailed study was published in 2021. Photometry was obtained with the TESS, ZTF, McDonald Observatory, SAAO, HAO, and JBO. Spectroscopy was obtained with SOAR, Magellan and the archived LDT spectrum. From the photometry the researchers find two significant periods at 9.937 and 11.2 hours (A-period and B-period). The dips change on nightly, weekly and monthly timescales. The researchers detected calcium, sodium, both with circumstellar origin. The sodium line is blueshifted by 21.4 ±1.0 km/s compared to the atmospheric lines. The researchers also identified atmospheric Hydrogen-alpha absorption. Due to the low amount of hydrogen, the researchers assume a helium dominated atmosphere. The variability of ZTF J0328-1219 is similar to WD 1145+017, but with notable differences. ZTF J0328-1219 is continuously variable, suggesting dust clouds orbit the white dwarf. These dust clouds either orbit the white dwarf on their own, or they are emitted by one or more bodies.
The two dust clouds would have semi-major axes of 2.11 and 2.28 . An orbiting exocomet is less likely because it would completely evaporate at this orbit within a few years. An orbiting exoasteroid on the other hand would not evaporate at this orbit. At the 9.93 hour orbit a body would be heated to a temperature of 700 Kelvin (K), but most minerals of asteroids evaporate at 1500-2500 K. The researchers propose several solutions for this problem:
Fine material ejected during collisions from bodies orbiting in a dust ring
Volatiles below the surface are heated and eject overlaying material (similar to some active asteroids in the solar system)
An exocomet with deep pits that preserve volatiles for later times
An exocomet orbiting within a dusty disk, shielding the comet from radiation, lowering the temperature
An exoasteroid with an eccentric orbit that will peel off material during periastron passage
A cascade of collisions beginning with the collision of two bodies
Observations of ZTF J0328-1219 showed a long-term fading event. The white dwarf faded by around 0.3 mag between 2012 and 2014. This is interpreted as increased transit activity during this time. This discovery is based on observations with the Thai National Telescope.
See also
List of stars that have unusual dimming periods
List of exoplanets and planetary debris around white dwarfs
References
External links
J0328-1219 observations with the Hereford Arizona Observatory (HAO) by amateur Bruce L. Gary, page 1 (page 2 and season 3, 4 are chain-linked within page 1)
Press release by the Boston University white dwarf group
White dwarfs
Hypothetical planetary systems
Eridanus (constellation) | ZTF J0328-1219 | [
"Astronomy"
] | 729 | [
"Eridanus (constellation)",
"Constellations"
] |
78,625,218 | https://en.wikipedia.org/wiki/M.G.%206669 | M.G. 6669 is an antidepressant and central nervous system equilibrating agent.
See also
EXP-561
References
Amines
Experimental antidepressants
Stimulants
Experimental drugs
Cyclohexanes | M.G. 6669 | [
"Chemistry"
] | 52 | [
"Amines",
"Bases (chemistry)",
"Functional groups"
] |
78,625,358 | https://en.wikipedia.org/wiki/Nuno%20Martins | Nuno Martins is a Portuguese scientist, entrepreneur, investor, and neuroscientist known for his pioneering work on brain cloud interface, nanotechnology, neuroscience, and robotics.
Education
Martins graduated from the inaugural year of the Singularity University at NASA Ames Research Center, Moffett Field, California. He also earned a PhD with Honors from University of Minho, Portugal, with his PhD Thesis titled: "Neuronanorobotics: a proposed medical technology to preserve human brain information"
Career
Martins is a Visiting Research Scholar at CSTMS the Center for Science Technology and Medicine at the University of California Berkeley, USA. He was a research affiliate at the Lawrence Berkeley National Laboratory, California, USA.
Martins is the founder and CEO of Lux Premium a real estate company in Portugal. He is also the co-founder and CEO of Hanu Ventures which is focused on longevity, biotechnology, Healthcare and artificial intelligence.
Selected publications
• PhD Thesis: Neuronanorobotics: a proposed medical technology to preserve human brain information.
• Martins NRB, Angelica A, Chakravarthy K, Svidinenko Y, Boehm FJ, Opris I, Lebedev MA, Swan M, Garan SA, Rosenfeld JV, Hogg T and Freitas RA Jr (2019) Human Brain/Cloud Interface. Front. Neurosci. 13:112. doi: 10.3389/fnins.2019.00112
• Nuno R. B. Martins, Wolfram Erlhagen, Robert A. Freitas Jr., “Human connectome mapping and monitoring using neuronanorobots”, Journal of Evolution and Technology – Vol. 26 Issue 1 – January 2016 – pgs 1-24
• Nuno R. B. Martins, Wolfram Erlhagen, Robert A. Freitas Jr., “Action Potential Monitoring Using Neuronanorobots: Neuroelectric Nanosensors”, Intl. J. Nanomaterials and Nanostructures 1(June 2015):20-41.
• Research Paper: Nuno R. B. Martins, Wolfram Erlhagen, Robert A. Freitas Jr., “Non-destructive whole-brain monitoring using nanorobots: Neural electrical data rate requirements”, Intl. J. Machine Consciousness 4(June 2012):109-140.
• Research Paper: Talaei K, Garan SA, Quintela BdM, Olufsen MS, Cho J, Jahansooz JR, Bhullar PK, Suen EK, Piszker WJ, Martins NRB, Moreira de Paula MA, dos Santos RW and Lobosco M (2021) A Mathematical Model of the Dynamics of Cytokine Expression and Human Immune Cell Activation in Response to the Pathogen Staphylococcus aureus. Front. Cell. Infect. Microbiol. 11:711153. doi: 10.3389/fcimb.2021.711153
References
Portuguese computer scientists
Portuguese neuroscientists
Living people
Year of birth missing (living people) | Nuno Martins | [
"Materials_science"
] | 651 | [
"Nanotechnology",
"Nanotechnologists"
] |
78,626,541 | https://en.wikipedia.org/wiki/HPH-15 | HPH-15 is an antifibrotic drug with higher AMPK-activation activity than metformin.
References
Antifibrinolytics | HPH-15 | [
"Chemistry"
] | 32 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
78,626,621 | https://en.wikipedia.org/wiki/Intrinsic%20DNA%20fluorescence | The term intrinsic DNA fluorescence refers to the fluorescence emitted directly by DNA when it absorbs ultraviolet (UV) radiation. It contrasts to that stemming from fluorescent labels that are either simply bound to DNA or covalently attached to it, widely used in biological applications; such labels may be chemically modified, not naturally occurring, nucleobases.
The intrinsic DNA fluorescence was discovered in the 1960s by studying nucleic acids in low temperature glasses. Since the beginning of the 21st century, the much weaker emission of nucleic acids in fluid solutions is being studied at room temperature by means sophisticated spectroscopic techniques, using as UV source femtosecond laser pulses, and following the evolution of the emitted light from femtoseconds to nanoseconds. The development of specific experimental protocols has been crucial for obtaining reliable results.
Fluorescence studies combined to theoretical computations, bring information about the relaxation of the electronic excited states and, thus, contribute to understanding the very first steps of a complex series of events triggered by UV radiation, ultimately leading to DNA damage. The principles governing the behavior of the intrinsic RNA fluorescence, to which only a few studies have been dedicated,
are the same as those described for DNA.
The knowledge of the fundamental processes underlying the DNA fluorescence paves the way for the development of label-free biosensors. The development of such optoelectronic devices for certain applications would have the advantage of bypassing a step of chemical synthesis or avoiding the uncertainties due to non-covalent biding of fluorescent dyes to nucleic acids.
Conditions for measuring the intrinsic DNA fluorescence
Due to the weak intensity of the intrinsic DNA fluorescence, specific cautions are necessary in order to perform correct measurements and obtain reliable results. A first requirement concerns the purity of both the DNA samples and that of the chemicals and the water used to the preparation of the buffered solutions. The buffer emission must be systematically recorded and, in certain cases, subtracted in an appropriate way. A second requirement is associated with the DNA damage provoked by the exciting UV light which alters its fluorescence. In order to overcome these difficulties, continuous stirring of the solution is needed. For measurements using laser excitation, the circulation of the DNA solution by means of a peristaltic pump is recommended; the reproducibility of successive fluorescence signal needs to be checked.
Spectral shapes and quantum yields
The fluorescence spectra of the DNA monomeric chromophores (nucleobases, nucleosides or nucleotides) in neutral aqueous solution, obtained with excitation around 260 nm, peak in the near ultraviolet (300-400 nm); and a long tail, extending all over the visible domain is present in their emission spectrum. The spectra of the DNA multimers (composed of more than one nucleobase) are not the sum of the spectra of their monomeric constituents. In some cases, in addition to a main peak located in the UV, a second band is present at longer wavelengths; it is attributed to excimer or exciplex formation.
The duplex spectra are affected by their size and the viscosity of the solution, while those of G-Quadruplexes by the metal cations present in their central cavity. Due to the fluorescence dependence on the secondary structure, it is possible to follow the formation and the melting of G-Quadruplexes by monitoring their emission; and also to detect the occurrence of hairpin loops in these systems.
The fluorescence quantum yields Φ, that is the number of emitted photons over the number of absorbed photons, are typically in the range of 10−4-10−3. The highest values are encountered for G-quadruplexes. The DNA nucleoside thymidine (dT) was proposed as a reference for the determination of small fluorescence quantum yields.
A limited number of measurements were also performed with UVA excitation (330 nm), where DNA single and double strands, but not their monomeric units, absorb weakly. The UVA-induced fluorescence peaks between 415 and 430 nm; the corresponding Φ values are at least one order of magnitude higher compared to those determined with excitation around 260 nm.
The fluorescence of some minor, naturally occurring nucleobases, such as 5-methyl cytosine, N7-methylated guanosine or N6-methyladenine, has been studied both in monomeric form and in multimers. The emission spectra of these systems are red-shifted compared to those of the major nucleobases and give rise to exciplexes.
Time-resolved techniques
The specificity of the intrinsic DNA fluorescence is that, contrary to most fluorescent molecules, its time-evolution cannot be described by a constant decay rate (corresponding to a mono-exponential decay). For the monomeric units, the fluorescence lasts at most a few picoseconds, and the decay rate is not constant. In the case of multimers, the fluorescence continues over much longer times, lasting in some cases for several tens of nanoseconds. The time constants derived from fittings with multi-exponential functions depend of the probed time window.
In order to obtain a complete picture of this complex time evolution, a femtosecond laser is needed as excitation source. Time-resolved techniques employed to this end are fluorescence upconversion, Kerr-gated fluorescence spectroscopy and time-correlated single photon counting. In addition to the changes in the fluorescence intensity, all of them allow the recording of time-resolved fluorescent spectra and fluorescence anisotropies, which provide information about the relaxation of the excited electronic states and the type of the emitting excited states.
The early studies were performed using time-correlated single photon counting combined with nanosecond sources (synchrotron radiation or lasers). Although they discovered the key difference between the behavior of monomeric and multimeric nucleic acids, they failed to obtain a full picture of the fluorescence dynamics.
Emitting excited states and their lifetimes
Monomeric chromophores
Emission from the monomeric DNA chromophores arises from their lower in energy electronic excited states, that is the ππ* states of the nucleobases. These are bright states, in the sense that they are also responsible for photon absorption.
Their lifetimes are extremely short: they fully decay within, at most, a few ps. Such ultrafast decays are due to the existence of conical intersections connecting the excited state with the ground state. Therefore, the dominant deactivation pathway is non-radiative, leading to very low fluorescence quantum yields.
The evolution toward the conical intersection is accompanied by conformational movements. An important part of the photons is emitted while the system is moving along the potential energy surface of the excited state, before reaching a point of minimum energy. As motions on a low-dimensional surfaces do not follow exponential patterns, the fluorescence decays are not characterized by constant decay rates.
Multichromophoric systems
Due to their close proximity, nucleobases in DNA multimers may be electronically coupled. This leads to delocalization of the excited states responsible for photon absorption (Franck-Condon states) over more than one nucleobase (collective states). The electronic coupling depends on the geometrical arrangement of the chromophores. Therefore, the properties of the collective states are affected by factors that determine the relative position of the nucleobases. Among others, the conformational disorder characterizing the nucleic acids modulates the coupling values, giving rise to a large number of Franck-Condon states. Each one of them evolves along a specific energy surface.
One can distinguish two limiting types of emitting states in DNA. On the one hand, ππ* states, localized on single nucleobases or delocalized over several of them. And on the other, excited charge transfer states in which an important fraction of an atomic charge has been transferred from one nucleobase to another. The latter are weakly emissive. And between these two types, there is a multitude of emitting states, more or less delocalized, with different amounts of charge transfer. The properties of the emitting states may be modified during their lifetime under the effect of conformational motions of the nucleic acid, occurring on the same time-scale. Because of this complexity, the description of the fluorescence decays by multiexponential functions is only phenomenological.
Experimentally, the different types of emitting states can be differentiated through their fluorescence anisotropy. The charge transfer character of an excited state lowers the fluorescence anisotropy. The decrease of fluorescence anisotropy observed for all the DNA multimers on the femtosecond time-scale was explained by an ultrafast transfer of the excitation energy among the nucleobases.
A particular class of emitting states with mixed ππ*/charge transfer character was detected in all types of duplexes, including genomic DNA. Their specificity is that their emission appears at short wavelengths (λ<330 nm) and represents the longest-living components of the overall duplex fluorescence decaying on the nanosecond timescale. It contrasts with the excimer/exciplex emission, characterized by a pronounced charge transfer character, appearing at long wavelengths and decaying on the sub-nanosecond time-scale. The contribution of the high energy emitting states to the total fluorescence increases with the local rigidity of the duplex, depending on the number of the Watson-Crick hydrogen bonds or the size of the system.
Applications
The utilization of the intrinsic fluorescence of nucleic acids for sensing purposes started to be scrutinized just in 2019. The possibility of detecting target DNA, Pb2+ ions, or aptamer binding, the screening of a large number of sequences and the authentication of COVID-19 vaccines have been explored. Moreover, the possibility of detecting the DNA damage by probing its fluorescence at short wavelengths (300 nm) has been discussed. Due to their modulable structure, G-quadruplexes, are particularly promising for the development of label-free and dye-free biosensors.
References
Further reading
Reviews and Accounts
Book Chapters
Biochemistry
Chemistry
Fluorescence
DNA | Intrinsic DNA fluorescence | [
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"Biology"
] | 2,157 | [
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78,627,051 | https://en.wikipedia.org/wiki/MWC%20656 | MWC 656 is an X-ray binary star system in the northern constellation of Lacerta. It has the identifier HD 215227 from the Henry Draper Catalogue. With an apparent visual magnitude of 8.75, it is too faint to be viewed with the naked eye. Based on parallax measurements, it is located at a distance of approximately 6,700 light years from the Sun. At one time it was considered a member of the Lacerta OB1 association of co-moving stars, but the distance estimate places it well past that group.
Observations
On August 11, 1935, R. F. Sanford found a weak emission line of Hydrogen–β in the spectrum of this star, and it was included in the 1943 supplement to the Mount Wilson catalogue of similar stars with the identifier MWC 656. In 1964, it was assigned a stellar classification of B5:ne, where 'B5' indicates this is a B-type star, 'n' means it displays 'nebular' lines due to rapid rotation, and 'e' shows it has emission lines. The ':' suffix indicates some uncertainty about the classification. It was included in a catalogue of Be stars in 1982. In 2005 it was found to have high projected rotational velocity of .
In 2009, the AGILE satellite discovered a nearby source of gamma-ray emission above . This source was given the identifier AGL J2241+4454. HD 215227 is the only suitable optical counterpart to lay within the 0.6° error circle. Spectra from the star showed evidence of emission from a circumstellar disk, as well as absorption from a shell feature. Rapid changes in emission line variability suggest an orbiting companion that is tidally interacting with the disk. Hipparcos light curve data indicated an orbital period of . This was confirmed in 2012 via radial velocity measurements of helium lines in photosphere of the Be star.
Refined radial velocity measurements in 2014 indicated a massive companion in the range of , assuming the Be star has a mass of . A main sequence companion with a mass this high should be readily visible in the optical band. Likewise, a subdwarf or a stripped helium core from a massive progenitor star don't fit the observations. The mass is too high for a white dwarf or a neutron star, leaving a stellar mass black hole as the only viable candidate. A faint X-ray emission was detected later the same year with a total luminosity of ·s−1, making this a high mass X-ray binary system. This luminosity is consistent with a stellar black hole in quiescence – meaning very little material is being fed into the black hole from the primary star.
This was the first reported binary system combining a black hole with a Be star. However, many Be stars are now found to have subdwarf OC companions, and the properties of these appear similar to MWC 656. The 2022 discovery of tidal distortion of the disk orbiting the Be star invalidated the original radial velocity amplitude, which called into question the 2014 mass estimates. The correction for this probably rules out a black hole companion. Emission from ionized helium near the companion appears double-peaked, indicating there is an orbiting accretion disk being fed from the disk orbiting the Be star. Revised measurements reported in 2023 found a mass range of for the companion, which means this is instead a neutron star, a white dwarf, or a hot helium star.
The position of the star at a distance of below the galactic plane suggests this is a runaway star system, since it is a young star not located near any star forming region. This scenario favors the neutron star companion.
References
Further reading
Be stars
Black holes
Subdwarfs
Astronomical X-ray sources
Lacerta
Durchmusterung objects
215227
112148 | MWC 656 | [
"Physics",
"Astronomy"
] | 783 | [
"Black holes",
"Physical phenomena",
"Physical quantities",
"Lacerta",
"Unsolved problems in physics",
"Astrophysics",
"Constellations",
"Density",
"Astronomical X-ray sources",
"Stellar phenomena",
"Astronomical objects"
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78,627,057 | https://en.wikipedia.org/wiki/Pressure-wind%20relationship%20calculations%20for%20tropical%20cyclones | There are several different methods to derive pressure from wind speed and vice versa in tropical cyclones. Both information minimum pressure and wind speed have their utilities. Wind speed can describe the destructive potential of a tropical cyclone.
Method
According to Christopher Burt from Weather Underground, the most reliable method of estimating pressure from wind involves using the Dvorak Technique with an infrared image, which shows how cold cloud tops are. Joe Courtney and John Knaff noted that as several models are based on Atlantic data, it can lead to biases in other parts of the world.
Most pressure-wind models are in the form of:
Where vm is the maximum wind, Δp is the change in pressure from an external point to the center. a and x are constants. Ted Fujita was the first to modify the exponent; before then, it mostly stood at 0.5.
Models
Knaff-Zehr
Knaff and Zehr (2007) came up with the following formula to relate wind and pressure, taking into account movement, size, and latitude:
Where Vsrm is the max wind speed corrected for storm speed, phi is the latitude, and S is the size parameter. S is more specifically defined as the ratio of tangential wind at a radius of to its value under a Rankine vortex model.
Holland
In 2008, Greg Holland published his model to the Monthly Weather Review.
Knaff-Zehr-Courtney
Joe Courtney and John A. Knaff published in 2009 a correction to the previous Knaff-Zehr model. They noted that the Knaff-Zehr model had issues with calculating for storms at low latitudes.
Usage
The interchangeability of pressure and wind allows for the two to be used to give equivalencies for the public. Pressure-wind relations can be used when information is incomplete, forcing forecasters to rely on the Dvorak Technique.
Some storms may have particularly high or low pressures that do not match with their wind speed. For example, Hurricane Sandy had a lower pressure than expected with its associated wind speed.
See also
Proxy data
Saffir–Simpson scale
References
Tropical cyclone meteorology
Synoptic meteorology and weather
Physical modeling | Pressure-wind relationship calculations for tropical cyclones | [
"Physics"
] | 444 | [
"nan"
] |
78,628,044 | https://en.wikipedia.org/wiki/NGC%206754 | NGC6754 is a barred spiral galaxy in the constellation of Telescopium. Its velocity with respect to the cosmic microwave background is 3176 ± 11km/s, which corresponds to a Hubble distance of . Additionally, 10 non-redshift measurements give a distance of . It was discovered by British astronomer John Herschel on 8 July 1834.
According to the SIMBAD database, NGC 6754 is an Active Galaxy Nucleus Candidate, i.e. it has a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars.
Supernovae
Four supernovae have been observed in NGC 6754:
SN1998X (typeII, mag. 17) was discovered by the Perth Astronomical Research Group on 13 March 1998.
SN1998dq (typeIa, mag. 14.3) was discovered by Brett White on 23 August 1998.
SN2000do (typeIa, mag. 15.6) was discovered by Brett White on 30 September 2000.
SN2005cu (typeII, mag. 16.1) was discovered by Berto Monard on 10 July 2005.
See also
List of NGC objects (6001–7000)
References
External links
6754
062871
19075-5043
231- G 025
Telescopium
18340708
Discoveries by John Herschel
Barred spiral galaxies | NGC 6754 | [
"Astronomy"
] | 306 | [
"Telescopium",
"Constellations"
] |
78,630,019 | https://en.wikipedia.org/wiki/C22H30N2O | {{DISPLAYTITLE:C22H30N2O}}
The molecular formula C22H30N2O (molar mass: 338.50 g/mol) may refer to:
Secofentanyl
SR-16435
Molecular formulas | C22H30N2O | [
"Physics",
"Chemistry"
] | 55 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
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