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where emissions, waste, toxins, and sprawl are legal is a race to the bottom. New thinking about the environment perceives it as an opportunity to use sustainability for competitive advantage, a tool to make a business leaner, cleaner, and less wasteful, beyond anything that regulations require — a race to |
the top. - Burst the bubble, embrace the critics: When secretive, insular Wal-Mart decided to throw open its doors to critics, inviting environmentalists and activists inside the infamous “Bentonville Bubble,” organizations like the environmental Defense Fund, Conservation international, and the natural resources Defen... |
for free. - Don’t wait for the market, lead it: Wal-Mart decided to get out in front of consumer demand on sustainability and found that it served the bottom line anyway — it pays to be green. But today’s sustainability eff orts mean the company will be ready when consumer |
After God dramatically delivered Israel from slavery in Egypt, He brought them to Mount Sinai. There, He joined them to Himself in a sacred covenant. Among all the varied instructions He gave them there, how was beauty included? Exod. 25:1–9.1 The first half of the book of Exodus details the miraculous deliverance of I... |
includes extensive details of artistry. This collection of details is tedious reading to many modern Christians. But it pleased God not only to present these many instructions to the newly-freed slaves but also to include them in Scripture. There are almost fifty chapters in the first five books of the Bible that recor... |
He provides not only the architectural blueprints but also the exact directions for the furnishings. It is significant that on Mount Sinai God gave not only the Decalogue, His instructions for obedience within the covenant, but also specific directions of how to fashion a lavish structure involving almost every type of... |
inspiring the artisans to craft the minute details of decoration. Nothing was left to human devising. There are more chapters regarding the plans for, and consequent building of, this sanctuary and its furnishings than for any other subject in the first five books of Moses. If the earthly sanctuary was only a “shadow” ... |
to imagine the kind of beauty that must exist in the real sanctuary, the one that God Himself made. Why do you think it was important for the sanctuary to be so beautiful? Perhaps to give the people a sense of awe before the power and grandeur of God? Maybe to help them sense their own need before such grandeur? |
In Python, for a binary file, I can write this: buf_size=1024*64 # this is an important size... with open(file, "rb") as f: while True: data=f.read(buf_size) if not data: break # |
deal with the data.... With a text file that I want to read line-by-line, I can write this: with open(file, "r") as file: for line in file: # deal with |
each line.... Which is shorthand for: with open(file, "r") as file: for line in iter(file.readline, ""): # deal with each line.... This idiom is documented in PEP 234 but I |
30 MB file, i==1 means read in one go... I tried putting iter(f.read(buf_size),'') but that is a syntax error because of the parens after the callable in iter(). I know |
I could write a function, but is there way with the default idiom of for chunk in file: where I can use a buffer size versus a line oriented? Thanks |
Update: If you’re reading these words the peak of the Quadrantid Meteor Shower has passed. But if you missed it, you can check out this slideshow or check out the video embedded below the jump. Earlier: If you didn’t see any fireworks on New Year’s Eve, you might want to |
look to the skies tonight (well, technically very early tomorrow). That’s when the Quadrantid Meteor Shower will reach its peek visibility for the year. Between 3 a.m. and sunrise Thursday morning, as many as 120 meteors an hour fall to earth in the shower. That could make for quite a |
show, but there’s a problem for people who want to watch in Texas. Actually, there are two of them. Many parts of the state are expecting cloudy weather. That alone could be a Quandrantid killer for a lot of stargazers, specifically those in Central and East Texas. And even if |
you’re under clear skies tonight, the moon could get between you and the shooting stars. It will be in a bright gibbous phase, and all that light could overpower the view of weaker meteors. For those who are not likely to catch the show outdoors there is one final option, |
and it doesn’t involve stepping into the cold winter air. NASA will be live streaming a video of the shower from a camera mounted at its Marshall Space Flight Center in Huntsville, Alabama. It’s set to begin streaming at approximately 5 p.m. Central Time. If you still want to check |
the showers the old fashioned way, NASA has a few simple tips. To view Quadrantids, go outside and allow your eyes 30-45 minutes to adjust to the dark. Look straight up, allowing your eyes to take in as much of the sky as possible. It couldn’t get much more simple |
|Evolution of plants ferns The oldest Four very old plants Parka Myriapods Crock Hey (Seed) ferns Scorpion Lepidodendron Sigillaria Calamites Wood of Calamites Cordaites The leaf of Neuropteris Little animals |
Graissessac Psaronius Permian of Lodève Bayreuth Yorkshire Gymnosperm wood Tree fern Tempskya Palm wood Hardwood Manosque Links Eight fossils A concise report of the development of the flora I. Silurian |
and Devonian Carboniferous and Early Permian III. Permian - Early Cretaceous IV. Cretaceous - present | The oldest fossils of land plants visible with the naked eye are about 425 |
million years old. They are miniscule plants from the Mid-Silurian of Ireland en are called Cooksonia. Cooksonia plants had dichotomously divided little stems with small knobs at the end. These |
knobs were sporangia and they were filled with spores. During about 20 or 30 millions of years these were the most common plants. They became extinct at the end of |
the Early Devonian. In the photo on the left my finest specimen of Cooksonia. It comes from South Wales and measures 3.5 cm. Click on the photos for enlargement. Click |
here for more information Recently microscopic remains have been found in Oman indicating that land plants existed already 475 million years ago. Probably land plants have developed from green algae |
living in the sea. | During the Early Devonian, from about 410 million years ago, more variation came into the flora. New groups of plants came into existence, but still |
the plants were small (up to 50 cm). Flowers developed only 250 millions of years later. Leaves didn't exist either, except for the scalelike leaves, like those of the clubmosses |
(click the photo on the right). Several plants had spines (click photo on the left). These were not for defending the plant, for animal life on the land was still |
minimal and the land animals were very small (millipedes, collembolans, trigonotarbids ('spiders'), very small crustaceans, etc.). Probably the function of the spines was to enlarge the green surface and so |
to enhance the assimilation. Furthermore the spines could have given more hold to the plants in forming small bushes of plants of the same species, hanging more or less on |
each other. All plants of that period were cryptogams (plants with spores), like at present the mosses, the ferns, the clubmosses and the horsetails. But they are so different from |
the living plants, that in nearly all cases it is impossible to identify to which group of recent plants they belong. All those ancient plants have become extinct. Relatively little |
is known about these primitive plants, because only a small number of complete and well preserved plants have been found. In most cases the plants have been transported by rivers |
before they ended up in the mud and could fossilize. Therefore the plants were mostly cut to small pieces before getting fossil. There are only a limited number of places |
where plants from the Silurian, the Lower and Middle Devonian have been well preserved. | A huge source of information on the oldest land plants is the so called Rhynie |
chert. About 400 million years ago there was a kind of Yellowstone Park near the place where Rhynie is now situated (click on the photo on the left). There were |
erupting vulcanos and geysers belching boiling water, saturated with silicium. That is how a complete silicified marsh came into existence with exceptionally well preserved plants, even showing their cell structure. |
Many animals have also been found in the chert. The photo on the right shows a stem of the plant Rhynia (1.3 mm in diameter). Click here for a more |
extensive description of the Rhynie chert. |During the Middle Devonian the plants became taller and little trees arose, sized up to a couple of meters. Recently a trunk with attached |
crown has been discovered in the State of New York. This tree is called Eospermatopteris and it could be sized up to 8 m. It lived in the late Middle |
Devonian. Read more about this subject. From the Late Devonian, Archaeopteris (don't confuse it with the ancient bird Archaeopterix) is the most well-known tree. It was possibly a predecessor of |
the conifers and this tree could reach a height of 18 m. The drawing on the left is a reconstruction from the fine website Devonian Times. Especially in Belgium quite |
a number of plants from the Upper Devonian are found. An example is Rhacophyton, occurring in the region of Liège (click photo on the right), which could very well be |
a precursor of the ferns. It lacks still leaves, but it has small hooks at the end of the branches. |At the end of the Devonian the first plants with |
seeds came into being. The oldest seed plant of Europe has been found in Belgium and it is has got its name after the village of Moresnet: Moresnetia (click photo |
on the left). This plant has primitive seeds: they are not yet entirely enveloped, like modern seeds. Recently a precursor of this plant has been discovered in Belgium with still |
more primitive 'seeds'. Click here for the original paper. The seed plants have become more ande more important in the course of the hundreds of million years. It appeared to |
be a successful formula because nowadays by far most plants are seed plants. The free-sporing plants have been pushed into the background. Click here for a more extensive description of |
Steeped in historical significance. And pretty to look at, too.. History As most would guess by the name alone, the Old Courthouse has moved on from its once pivotal role as the federal court in the city of St. Louis to being a charming historical landmark. Just two blocks from the Gateway Arch, the Courthouse has long... |
landscape, though its 150-year-plus history makes it much more than just eye candy. Inside the building, you can tour two restored courtrooms and several galleries dedicated to the rich history of St. Louis. Judgments Built in 1828, the Old Courthouse played host to some of the most important cases of the 19th century.... |
here in 1847 and 1850, pivotal events that set the stage for the Civil War. A plaque on the west side of the courthouse commemorates the Dred Scott decisions and their importance. Also, in the 1870s, Virginia Minor sued for her right to vote in this courthouse. |
New study details lethal impacts of a fungicide commonly used on golf courses around the world By Summit Voice SUMMIT COUNTY — Despite the lessons learned from the effects of DDT, people continue to use chemicals in the same organochlorine family, to the detriment of natural ecosystems. Now, University of |
South Florida researchers have shown that one of the world’s most common fungicides is lethal to a wide variety of freshwater organisms and essentially crashes ecosystems from the bottom up. Biologists Taegan McMahon and Jason Rohr tested the effects of Chlorothalonil, a common fungicides used pervasively on food crops... |
golf courses. Even at levels below those deemed safe by the EPA, the chemical killed amphibians, snails, zooplankton, algae, and aquatic plants The loss of these herbivores and plants freed the algae from predation and competition, which eventually resulted in algal blooms that were similar to the effects of eutrophica... |
“Some species were able to recover from the chemical assault, but the ecosystem was fundamentally changed after its exposure to chlorothalonil,” Rohr said. The four-week study was conducted in a series of 300-gallon tanks used to mimic pond conditions. It follows a 2011 laboratory study conducted by McMahon and Rohr |
that found that ecologically-relevant concentrations of chlorothalonil killed four species of amphibians. “Although our new study is the only reported community- and ecosystem-level experiment on chlorothalonil, our results are consistent with several direct toxicity studies conducted in the laboratory and with observa... |
and fungus by disrupting cellular respiration, an essential process for most multicellular organisms on the planet. Like the infamous DDT, chlorothalonil is a member of the organochlorine chemical family. “In addition, to reducing biodiversity and altering ecosystem functions, chlorothalonil reduced the decomposition o... |
provide to humans,” McMahon added. “Interest in the relationship between biodiversity and ecosystem functions stems at least partly from the concern that anthropogenically-driven declines in biodiversity will reduce or alter the benefits offered by ecosystems,” Rohr said. “Surprisingly, however, this is one of the firs... |
anthropogenic factor and link it to changes in ecosystem functions mediated by declines in biodiversity.” “This is important because many species in ecosystems might contribute little to ecosystem functions or are functionally redundant with other species, and thus declines in biodiversity do not always affect the func... |
ecosystems,” Rohr said. McMahon and Rohr encourage further research on effects of anthropogenic factors on ecosystem functions in systems with complex food webs and the re-evaluation of the safety of chlorothalonil. |
The 1st Octet already specify the network class (1-127: A, 128-191: B, 192-223: C etc.). A, B, or C implies the number of octets for network (respectively, 255.0.0.0, 255.255.0.0, 255.255.255.0), which automatically tells you how many hosts is allowed for each class of While this was historically true. This hasn't |
been true for years. Years ago 188.8.131.52/8 was given out in pieces to various ISPs. (I believe this was mostly to cable providers.) Even when it was true for network assignments, netmasks were necessary for internal networks to simplify routing. Efficient routing of a network like 10.0.0.0/8 requires subdivision int... |
is routed directly from the device, while other addresses are passed through a router. Hosts with multiple interfaces may be connected to networks of different sizes. For sub-nets without multi-homed hosts a /24 contains more addresses than is required. Most routers I have worked with have 24, 48, or 96 |
need a subnet mask? Many devices use a default netmask of /24 which in many cases matches the size of the local subnet (localnet) assigned to the router. This is equally applicable to classes A, B, and C. Unless the subnet size matches the default subnet a netmask is required. |
If addresses are specified using CIDR format, the netmask and network can be calculated from the address. If not the network can be calculated from the address and netmask. It is not possible to reliably calculate the netmask from the address and network. Providing a gateway (router) address for a |
Select the product you need help with - Internet Explorer - Windows Phone - More products Detailed Explanation of FAT Boot Sector Article ID: 140418 - View products that this article applies to. This article was previously published under Q140418 Understanding the content and function of a file system "boot sector" can... |
corruption. From time to time, usually due to hardware failure or virus infection, a boot sector may become corrupted. If the partition is the active primary partition, or a partition containing operating system files, this can prevent the system from starting. Otherwise, it may simply prevent access to data on the dri... |
best to use commercial anti- virus or disk recovery software. In some cases, however, detailed knowledge of the boot sector can come in handy. This article explains the various fields of a FAT boot sector. Using the following information, it may be possible to manually repair a damaged FAT boot sector. In order to atte... |
tools capable of editing raw disk sectors are required. This article does not discuss specific tools which can be used to perform such a repair operations. While every effort has been made to ensure the accuracy of the following information, different operating systems, including future versions of Microsoft operating ... |
of the following information at your own risk. Background and TerminologyIn this document, a "file system boot sector" is the first physical sector on a logical volume. A logical volume might be a primary partition, a logical drive in an extended partition, or a composite of two or more partitions, as is the case with ... |
sets. On floppy disks, the boot sector is the first sector on the disk. In the case of hard drives, the first sector is referred to as the "Master Boot Record" or "MBR." This MBR is different from a file system boot sector and contains a partition table, which describes the layout of logical partitions on that hard dri... |
file system boot sector would be the first sector in one of those partitions. The Boot ProcessThe boot process of 80x86-based personal computers (as opposed to RISC- based systems) makes direct use of a file system boot sector for executing instructions. The initial boot process can be summarized as follows: In the cas... |
installed, the FAT boot sector is responsible for identifying the location of the file "NTLDR" on the volume, loading it into memory, and transferring control to it. Inside the FAT Boot SectorBecause the MBR transfers CPU execution to the boot sector, the first few bytes of the FAT boot sector must be valid executable ... |
practice these first instructions constitute a "jump" instruction and occupy the first 3 bytes of the boot sector. This jump serves to skip over the next several bytes which are not "executable." Following the jump instruction is an 8 byte "OEM ID". This is typically a string of characters that identifies the operating... |
OEM ID is a structure known as the BIOS Parameter Block, or "BPB." Taken as a whole, the BPB provides enough information for the executable portion of the boot sector to be able to locate the NTLDR file. Because the BPB always starts at the same offset, standard parameters are always in a known location. Because the fi... |
the boot sector is a jump, the BPB can be extended in the future, provided new information is appended to the end. In such a case, the jump instruction would only need a minor adjustment. Also, the actual executable code can be fairly generic. All the variability associated with running on disks of different sizes and ... |
the BPB. The BPB is stored in a packed (that is, unaligned) format. The following table lists the byte offset of each field in the BPB. A description of each field follows the table. Bytes Per Sector: This is the size of a hardware sector and for most disks in use in the United States, the value of this field |
will be 512. Field Offset Length ----- ------ ------ Bytes Per Sector 11 2 Sectors Per Cluster 13 1 Reserved Sectors 14 2 FATs 16 1 Root Entries 17 2 Small Sectors 19 2 Media Descriptor 21 1 Sectors Per FAT 22 2 Sectors Per Track 24 2 Heads 26 2 Hidden Sectors 28 4 Large Sectors 32 4 Sectors |
Per Cluster: Because FAT is limited in the number of clusters (or "allocation units") that it can track, large volumes are supported by increasing the number of sectors per cluster. The cluster factor for a FAT volume is entirely dependent on the size of the volume. Valid values for this field are 1, 2, 4, 8, 16, 32, 6... |
128. Query in the Microsoft Knowledge Base for the term "Default Cluster Size" for more information on this subject. Reserved Sectors: This represents the number of sectors preceding the start of the first FAT, including the boot sector itself. It should always have a value of at least 1. FATs: This is the number of co... |
stored on the disk. Typically, the value of this field is 2. Root Entries: This is the total number of file name entries that can be stored in the root directory of the volume. On a typical hard drive, the value of this field is 512. Note, however, that one entry is always used as a Volume Label, and that |
files with long file names will use up multiple entries per file. This means the largest number of files in the root directory is typically 511, but that you will run out of entries before that if long file names are used. Small Sectors: This field is used to store the number of sectors on the disk if the size |
of the volume is small enough. For larger volumes, this field has a value of 0, and we refer instead to the "Large Sectors" value which comes later. Media Descriptor: This byte provides information about the media being used. The following table lists some of the recognized media descriptor values and their associated ... |
may be associated with more than one disk capacity. Sectors Per FAT: This is the number of sectors occupied by each of the FATs on the volume. Given this information, together with the number of FATs and reserved sectors listed above, we can compute where the root directory begins. Given the number of entries in the ro... |
also compute where the user data area of the disk begins. Byte Capacity Media Size and Type F0 2.88 MB 3.5-inch, 2-sided, 36-sector F0 1.44 MB 3.5-inch, 2-sided, 18-sector F9 720 KB 3.5-inch, 2-sided, 9-sector F9 1.2 MB 5.25-inch, 2-sided, 15-sector FD 360 KB 5.25-inch, 2-sided, 9-sector FF 320 KB 5.25-inch, 2-sided, 8... |
160 KB 5.25-inch, 1-sided, 8-sector F8 ----- Fixed disk Sectors Per Track and Heads: These values are a part of the apparent disk geometry in use when the disk was formatted. Hidden Sectors: This is the number of sectors on the physical disk preceding the start of the volume. (that is, before the boot sector itself) It... |
the boot sequence in order to calculate the absolute offset to the root directory and data areas. Large Sectors: If the Small Sectors field is zero, this field contains the total number of sectors used by the FAT volume. Some additional fields follow the standard BIOS Parameter Block and constitute an "extended BIOS Pa... |
Drive Number: This is related to the BIOS physical drive number. Floppy drives are numbered starting with 0x00 for the A: drive, while physical hard disks are numbered starting with 0x80. Typically, you would set this value prior to issuing an INT 13 BIOS call in order to specify the device to access. The on-disk value... |
is typically 0x00 for floppies and 0x80 for hard disks, regardless of how many physical disk drives exist, because the value is only relevant if the device is a boot device. Field Offset Length ----- ------ ------ Physical Drive Number 36 1 Current Head 37 1 Signature 38 1 ID 39 4 Volume Label 43 11 System ID 54 8 |
Current Head: This is another field typically used when doing INT13 BIOS calls. The value would originally have been used to store the track on which the boot record was located, but the value stored on disk is not currently used as such. Therefore, Windows NT uses this field to store two flags: ID: The ID is a random ... |
number assigned at format time in order to aid in distinguishing one disk from another. Volume Label: This field was used to store the volume label, but the volume label is now stored as a special file in the root directory. System ID: This field is either "FAT12" or "FAT16," depending on the format of the disk. On a b... |
volume, the area following the Extended BIOS Parameter Block is typically executable boot code. This code is responsible for performing whatever actions are necessary to continue the boot-strap process. On Windows NT systems, this boot code will identify the location of the NTLDR file, load it into memory, and transfer... |
there is executable code in this area. The code necessary to print the familiar message, "Non-system disk or disk error" is found on most standard, MS-DOS formatted floppy disks that were not formatted with the "system" option. Finally, the last two bytes in any boot sector always have the hexidecimal values: 0x55 0xAA... |
sector is corrupt, you can check several of the fields listed above to see whether the values listed there make sense. For example, BytesPerSector will be 512 in the vast majority of cases. You would also expect to see text strings in the executable code section of the boot sector that are appropriate for the operating... |
disk. Typical text strings on FAT volumes formatted by MS-DOS include: "Invalid system disk."; "Disk I/O error."; "Replace the disk, and then press any key"; "Non-System disk or disk error"; "Replace and press any key when ready."; and "Disk Boot failure." Text strings on FAT volumes formatted by Windows NT include: "B... |
"Please insert another disk." You should not regard this list as being all-inclusive. If you find other messages in the boot sector, this does not necessarily indicate that there is a problem with the boot sector. Different versions of MS-DOS and Windows NT will sometimes have slightly different message strings in thei... |
find no text whatsoever, or if the text is clearly not related to MS-DOS or Windows NT, you should consider the possibility that your boot sector may have been infected by a virus or that some other form of data corruption may have taken place. To recover from a boot sector that has been infected by a virus, it is |
usually best to use a commercial anti-virus program. Many viruses will do much more than just write data to the boot sector, so manual repair of the boot sector is not recommended, as it may not completely eliminate the virus and in some cases, may do more harm than good. If you suspect that the boot sector was damaged... |
some other reason, it is usually best to use commercial disk recovery tools. While it may be possible to recover from boot sector damage without resorting to reformatting the drive by manually modifying the fields described above, manual editing of boot sectors should only be attempted as a last resort and cannot be gu... |
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