Snowflake chemistry


This video says about itself:

The Chemistry of Snowflakes – Bytesize Science

The video tracks formation of snowflakes from their origins in bits of dust in clouds that become droplets of water falling to Earth. When the droplets cool, six crystal faces form because water molecules bond in hexagonal networks when they freeze.

It explains that ice crystals grow fastest at the corners between the faces, fostering development of the six branches that exist in most snowflakes. As snowflakes continue to develop, the branches can spread, grow long and pointy, or branch off into new arms. As each snowflake rises and falls through warmer and cooler air, it thus develops its own distinctive shape.

Produced by the American Chemical Society.

Triassic wildlife after mass extinction


This video is called Excavating Triassic Fossils in Antarctica.

From ANI news agency:

Ups and downs of biodiversity after mass extinction unveiled

Saturday 22nd December, 2012

Marine animal groups like ammonoids and conodonts already peaked three or four million years earlier, namely still during the Early Triassic, researchers say.

The climate after the largest mass extinction so far 252 million years ago was cool, later very warm and cool again. Thanks to the cooler temperatures, the diversity of marine fauna ballooned, as paleontologists from the University of Zurich have reconstructed.

The warmer climate, coupled with a high CO2 level in the atmosphere, initially gave rise to new, short-lived species. In the longer term, however, this climate change had an adverse effect on biodiversity and caused species to become extinct.

Until now, it was always assumed that it took flora and fauna a long time to recover from the vast mass extinction at the end of the Permian geological period 252 million years ago.

According to the scientific consensus, complex ecological communities only began to reappear in the Middle Triassic, so 247 million years ago.

However, a Swiss team headed by paleontologist Hugo Bucher from the University of Zurich chart the temperature curves, demonstrating that the climate and the carbon dioxide level in the atmosphere fluctuated greatly during the Early Triassic and what impact this had on marine biodiversity and terrestrial plants.

For their climate reconstruction, Bucher and his colleagues analyzed the composition of the oxygen isotopes in conodonts, the remains of chordates that once lived in the sea. According to the study, the climate at the beginning of the Triassic 249 million years ago was cool.

This cooler phase was followed by a brief very warm climate phase. At the end of the Early Triassic, namely between 247.9 and 245.9 million years ago, cooler conditions had resumed.

The scientists then examined the impact of the climate on the development of flora and fauna.

“Biodiversity increased most in the cooler phases,” Bucher said.

“The subsequent extremely warm phase, however, led to great changes in the marine fauna and a major ecological shift in the flora,” he said.

Bucher and his team can reveal that this decline in biodiversity in the warm phases correlates with strong fluctuations in the carbon isotope composition of the atmosphere.

These, in turn, were directly related to carbon dioxide gases, which stemmed from volcanic eruptions in the Siberian Large Igneous Province.

Through the climatic changes, conodont and ammonoid faunae were initially able to recover very quickly during the Early Triassic as unusually short-lived species emerged. However, the removal of excess CO2 by primary producers such as algae and terrestrial plants had adverse effects in the long run: The removal of these vast amounts of organic matter used up the majority of the oxygen in the water. Due to the lack of oxygen in the oceans, many marine species died out.

“Our studies reveal that greater climatic changes can lead to both the emergence and extinction of species. Thus, it is important to consider both extinction rates and the rate at which new species emerged,” Bucher added.

The study has been published in Nature Geoscience.

More than 200 million years ago, a massive extinction decimated 76 percent of marine and terrestrial species, marking the end of the Triassic period and the onset of the Jurassic. The event cleared the way for dinosaurs to dominate Earth for the next 135 million years, taking over ecological niches formerly occupied by other marine and terrestrial species: here.

United States military bear abuse


This video is called HIMALAYAN BLACK BEAR.

From the Daily Mirror in Britain:

By David Collins

Grizzly end: Bears were fired out of US supersonic jet in ejector seat tests

21 Dec 2012 21:00

The animals were drugged before the flights and were ejected at various speeds and altitudes to determine how well the system worked

He was one of six Himalayan and American Black bears used in testing of the pilot ejection systems of the Convair B-58 Hustler – only to be later put down so the impact on their bodies could be determined by postmortem.

The animals, seen here in a US Air Force video, were drugged before the flights and were ejected at various speeds and altitudes to determine how well the system worked.

A white paper by the National Academy of Sciences National Research Council, which ran the tests, said: “None of the bears received any internal injuries and no spinal fractures occurred on any test.

“One American Black bear was discovered on autopsy to have a laceration of the liver which was attributed partially to an overdose of anaesthesia.”

The four-engined B-58 Hustler flew at Mach 2 – twice the speed of sound – and was created at the height of the Cold War to drop bombs in case of a nuclear war with the Soviet Union.

The animals were ejected at speeds up to Mach 1.6 at 45,000 feet in the tests, which took place in 1961 at Brooks Air Force Base in Texas.

The bear in the video can be seen with its jaws tied shut being unfastened from a capsule by airmen after it landed and being stretchered away.

US Air Force use bears to test their ejector seats for their fighter pilots during the Cold War.

Science writer Ed Grabianowski, of i09.com, said: “On one hand, using bears for these tests was an extremely practical solution to the problem.

“The Air Force was working on a fix for something that had already caused human deaths.

“On the other hand, it’s hard not to cringe when you imagine the terror and confusion these animals experienced.

“Luckily, the testing programme didn’t last very long.”

Though this particular abuse may be over, NATO is still abusing pigs, monkeys and other animals in Britain and elsewhere.

Mistletoe, myth and reality


This video is called American Mistletoe, Phoradendron leucarpum.

From eNature Blog in the USA:

Is Holiday Mistletoe Really The “Kiss of Death”?

Posted on Monday, December 17, 2012 by eNature

Almost all of us have come across American Mistletoe, the white or green-berried parasitic plant hung in doorways during the holiday season to elicit kisses from those standing beneath it.

Reputed to be the “kiss of death,” Mistletoe (the Phoradendron species is found in North America) is said by some to be so poisonous that humans can be killed if they ingest the leaves or berries.

This myth has been endlessly repeated throughout the years, reappearing every December in countless holiday safety reports on television and in print.

Is it true? Is American Mistletoe a holiday killer?

What The Research Says

Two physicians and researchers from Pittsburgh decided to find out. Dr. Edward P. Krenzelok of the Children’s Hospital of Pittsburgh) and Dr. Terry Jacobson from Carnegie Mellon University examined data from the American Association of Poison Control Centers and found 1,754 reports of mistletoe exposure over a seven-year span.

Curiously, not only had no one died of mistletoe poisoning, in the overwhelming majority of the cases (approximately 90 percent), the patient experienced no effects at all.

Those patients who did have effects suffered only minor discomfort. Treatment at a poison control center or at home made no discernible difference in patients’ recovery or outcome. Most mistletoe ingestion is reported in children, often those under two, who finding a couple of berries or leaves that have dropped to the floor will put them in their mouths.

What To Do If You Ingest Mistletoe

Drs. Krenzelok and Jacobson found that most, if not all, exposure to Mistletoe was not dangerous. That said, children who ingest the plant or its berries should be observed and treated for poisoning symptoms, such as nausea or diarrhea, at home if they do arise. They suggest that parents call their local poison control center and follow the advice given. The study did not indicate whether ingestion of large quantities of mistletoe might be more toxic, nor did it address the degree of exposure that might be toxic in pets (who might be inclined to eat a larger quantity than a child).

Causing at most only minor discomfort, American Mistletoe does not seem to have earned its reputation as the “kiss of death.” Its European cousin, Viscum album, sometimes used in herbal remedies, is more toxic, but is not sold commercially in North America and is thus rarely encountered.

A Bit More About Mistletoe

Mistletoe is an interesting plant— it’s a semi-parasitic shrub which grows on other trees. Although able to photosynthesize its own nutrients, mistletoe relies on its host for most of its nutrients. The plant draws its mineral and water needs, and some of its energy needs, from the host tree using a specialized root called a haustorium, which grows into the stem of the host. …

It’s also quite easy to harvest, provided you’re comfortable climbing trees. Your editor and his high school friends funded many camping trips by harvesting mistletoe in the local woods and selling it to classmates during the Holidays!

And now that we know it’s safe to have around the house, go ahead and hang it from a convenient doorway.

Do you have any mistletoe stories to share? We always enjoy hearing them.

Good English squirrel news


This video from England is called Red squirrel DaresburyCheshire Mammal Group.

From Wildlife Extra:

Red squirrel sighted in Cheshire for the first time since 1980s

Has a Lancashire squirrel gone wandering?

December 2012. A red squirrel has been sighted in Cheshire for the first time since 1980s. Cheshire Wildlife Trust has described the sighting of a wild red squirrel in a Daresbury garden between Runcorn and Warrington as ‘extremely exciting’.

The rare mammal, which is mostly confined to Scotland and small populations scattered elsewhere across the UK, was last seen in the Cheshire region during the 1980s. The sighting was confirmed by members of the Warrington Conservation Forum and Cheshire Mammal Group, after a video was captured of the furry visitor making the most of local bird feeders.

A captive population of red squirrels is kept at Walton Gardens, but the nearest wild population is on the Sefton Coast, Lancashire. This group of red squirrels suffered a devastating recent drop in numbers after the squirrels succumbed to an infection of pox.

Adult squirrel

Expert Paul Hill of the local Mammal Group said that it was typical for young squirrels to explore beyond their usual territories during the autumn and winter, however the footage appeared to show an adult which was particularly interesting.

Special nut feeders

A team has now installed specialised nut feeders in the area which allow red squirrels to feed, but exclude the larger grey squirrel. Motion detection cameras will also be inspected over the coming weeks to see if the red squirrels return and to determine if there may be more than one.

Tom Marshall from Cheshire Wildlife Trust said: “This is a fantastic good news story and we really hope this visiting red squirrel is not alone. Our colleagues at Lancashire Wildlife Trust have worked hard on the recovery of red squirrels on the Sefton Coast, and to know that the squirrels are potentially exploring beyond this territory could be amazing for the Cheshire region.”

Red squirrels are continuing to suffer from the intrusion of their larger, non-native American cousins into their historical haunts in northern Britain. Bolder and more aggressive, grey squirrels are also able to exploit many nuts earlier in the season, reducing supplies for red squirrels.

Recent conservation strategies have included culling the non-native greys across a ‘firewall’ in parts of Scotland and northern England to try and minimise the northern spread in efforts to safeguard remaining populations of red squirrels.

If you think you have seen a red squirrel please try and capture a photograph or video to aid identification and share it via the Facebook pages of Cheshire Wildlife Trust or Warrington Conservation Forum. You can also e-mail info@cheshirewt.org.uk

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