Category Archives: Life Science

Study Shows Why the Flu Likes Winter

Study Shows Why the Flu Likes Winter:

The answer, they say, has to do with the virus itself. It is more stable and stays in the air longer when air is cold and dry, the exact conditions for much of the flu season.

“Influenza virus is more likely to be transmitted during winter on the way to the subway than in a warm room,” said Peter Palese, a flu researcher who is professor and chairman of the microbiology department at Mount Sinai School of Medicine in New York and the lead author of the flu study. Dr. Palese published details of his findings in the Oct. 19 issue of PLoS Pathogens.

Reading a paper published in 1919 in the Journal of the American Medical Association on the flu epidemic at Camp Cody in New Mexico, he came upon a key passage: “It is interesting to note that very soon after the epidemic of influenza reached this camp, our laboratory guinea pigs began to die.”
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Dr. Palese bought some guinea pigs and exposed them to the flu virus. Just as the paper suggested, they got the flu and spread it among themselves. So Dr. Palese and his colleagues began their experiments. By varying air temperature and humidity in the guinea pigs’ quarters, they discovered that transmission was excellent at 41 degrees. It declined as the temperature rose until, by 86 degrees, the virus was not transmitted at all.

The virus was transmitted best at a low humidity, 20 percent, and not transmitted at all when the humidity reached 80 percent. The animals also released viruses nearly two days longer at 41 degrees than at a typical room temperature of 68 degrees.

Very interesting and you can read the actual paper since it is open access: Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature.

Related: I Support the Public Library of Science – New and Old Ways to Make Flu Vaccines – Open Access and PLoS – Drug-resistant Flu Virus

More on the Problems with Bisphenol-A

Milwaukee Journal-Sentinel: Bisphenol-A, that plasticizer, gets a media reaming

But few reports that The Tracker has seen match, in fury and conviction, the lambasting that a team of Milwaukee Journal Sentinel reporters, Susanne Rust, Meg Kissinger, and Cary Spivak, have given to these things, especially bisphenol-A, in the last two weeks. They say they reviewed 250 papers, interviewed more than 100 scientists, industry reps, and government regulators, read thousands of pages of additional documents. They give it a one-two punch, with that second one the roundhouse. They are going for a knockout.

The stories make The Tracker, a person with a tendency to say “on the other hand…”, a little nervous. There aren’t many maybes in here, not much calibration. The reporters appear fully convinced bisphenol-A is a menace. I’ve heard reports on the stuff too, and it does give one the jim jams. But one seldom sees, as here and without equivocation, declarations that a recent government review was flatly biased in its selection of which studies to give most weight, the gov’t used outdated methods, it looked mainly at chemical industry-funded studies, it ignored academic and presumably unbiased work.

The original articles: Are your products safe? You can’t tell. Labels often fail to list compounds that can disrupt biological development – WARNING: The chemical bisphenol A has been known to pose severe health risks to laboratory animals. AND THE CHEMICAL IS IN YOU.

In the first analysis of its kind by a newspaper, the Journal Sentinel reviewed 258 scientific studies of the chemical bisphenol A, a compound detected in the urine of 93% of Americans recently tested. An overwhelming majority of these studies show that the chemical is harmful – causing breast cancer, testicular cancer, diabetes, hyperactivity, obesity, low sperm counts, miscarriage and a host of other reproductive failures in laboratory animals.

Studies paid for by the chemical industry are much less likely to find damaging effects or disease. U.S. regulators so far have sided with industry by minimizing concern about the compound’s safety.

I believe in there are real risks that should be addressed. And I am not convinced the regulators are doing a good job, see my previous post in April, 2007 on Bisphenol A.

Related: Flushed Drugs Pollute Water – FDA May Make Decision That Will Speed Antibiotic Drug Resistance – The A to Z Guide to Political Interference in Science – Researcher Provides Undisclosed Data to FDA – Scientists Denounce Global Warming Report ‘Edits’

Dinosaur Remains Found with Intact Skin and Tissue

Hadrosaur Dinasaur

“Dinosaur Mummy” Found; Has Intact Skin, Tissue by John Roach, National Geographic News:

Scientists today announced the discovery of an extraordinarily preserved “dinosaur mummy” with much of its tissues and bones still encased in an uncollapsed envelope of skin. Preliminary studies of the 67-million-year-old hadrosaur, named Dakota, are already altering theories of what the ancient creatures’ skin looked like and how quickly they moved, project researchers say
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The hadrosaur, or duck-billed dinosaur, was discovered in 1999 by then-teenage paleontologist Tyler Lyson on his family’s North Dakota property.
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Plant-eating hadrosaurs are often called the “cows of the Cretaceous”—the geologic period that spanned 145 million to 65 million years ago—Manning said. They had horny, toothless beaks but hundreds of teeth in their cheeks and a long, stiff tail that was likely used for balance. Preliminary studies are revealing a surprising side to these reptiles, suggesting that Dakota—even though roughly 35 feet (12 meters) long and weighing some 35 tons—was no slowpoke.
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The preliminary calculations suggest Dakota could run 28 miles (45 kilometers) an hour. Tyrannosaurus rex tops out at about 20 miles (32 kilometers) an hour, according to the model

The dig and subsequent scanning are the subjects of Dino Autopsy, a National Geographic Channel special airing on December 9th.

Amazing find of dinosaur ‘mummy’, BBC:

this hadrosaur came complete with fossilised skin, ligaments, tendons and possibly some internal organs, according to researchers. “It’s unbelievable when you look at it for the first time,” said palaeontologist Phillip Manning from the University of Manchester, UK. “There is depth and structure to the skin. The level of detail expressed in the skin is just breathtaking.”

Related: Nigersaurus – T-rex Treasure – Most Dinosaurs Remain Undiscovered

People Have More Bacterial Cells than Human Cells

Humans Carry More Bacterial Cells than Human Ones

All the bacteria living inside you would fill a half-gallon jug; there are 10 times more bacterial cells in your body than human cells
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The infestation begins at birth: Babies ingest mouthfuls of bacteria during birthing and pick up plenty more from their mother’s skin and milk—during breast-feeding, the mammary glands become colonized with bacteria. “Our interaction with our mother is the biggest burst of microbes that we get,”
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there are estimated to be more than 500 species living at any one time in an adult intestine, the majority belong to two phyla, the Firmicutes (which include Streptococcus, Clostridium and Staphylococcus), and the Bacteroidetes (which include Flavobacterium).
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probiotics – dietary supplements containing potentially beneficial microbes – have been shown to boost immunity. Not only do gut bacteria “help protect against other disease-causing bacteria that might come from your food and water,” Huffnagle says, “they truly represent another arm of the immune system.”
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But the bacterial body has made another contribution to our humanity – genes. Soon after the Human Genome Project published its preliminary results in 2001, a group of scientists announced that a handful of human genes – the consensus today is around 40 – appear to be bacterial in origin.

How cool is science? Very, I think 🙂

Related: Tracking the Ecosystem Within Us – Beneficial Bacteria – Energy Efficiency of Digestion – Large Number of Bacteria on our Skin – Where Bacteria Get Their Genes – Amazing Science: Retroviruses

Fighting Tuberculosis

Signaling an End to TB by Kathleen M. Wong

Once routinely treated with cheap antibiotics, TB is poised to make a terrifying comeback. More and more, doctors in developing nations are finding patients infected with strains of TB invulnerable to all but a handful of extremely expensive, exotic drugs. Worldwide, TB already infects one in every three people and sickens one in ten. Without new methods to stop the spread of drug-resistant strains, the cost of treating this ancient human pathogen could bankrupt even the most prosperous economies.
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TB could, in theory, develop resistance to this new class of drugs, too. But Alber thinks he can skew the odds to favor humans. Identifying a drug capable of knocking out several TB enzymes at once could make it next to impossible for the bacterium to evolve resistance on multiple fronts.

Though TB is a daunting foe, Alber remains confident about the prospects of beating the disease. “As a bacterium, it should be easier to treat than HIV or malaria. Those kinds of diseases-caused by viruses and protozoans-we generally don’t know how to cure,” Alber says. “From a scientific perspective, TB is a simpler problem.”

Good luck, it may be easier but it still isn’t easy. Related: Tuberculosis Risk – ‘Virtually untreatable’ TB – Extensively Drug-resistant Tuberculosis (XDR TB) – TB Pandemic Threat

Amazing Science: Retroviruses

One of the great things about writing this blog is I find myself more focused on reading about interesting science. Retroviruses are very interesting and frankly amazing. Darwin’s Surprise by Michael Specter, The New Yorker:

A retrovirus stores its genetic information in a single-stranded molecule of RNA, instead of the more common double-stranded DNA. When it infects a cell, the virus deploys a special enzyme, called reverse transcriptase, that enables it to copy itself and then paste its own genes into the new cell’s DNA. It then becomes part of that cell forever; when the cell divides, the virus goes with it. Scientists have long suspected that if a retrovirus happens to infect a human sperm cell or egg, which is rare, and if that embryo survives – which is rarer still – the retrovirus could take its place in the blueprint of our species, passed from mother to child, and from one generation to the next, much like a gene for eye color or asthma.

When the sequence of the human genome was fully mapped, in 2003, researchers also discovered something they had not anticipated: our bodies are littered with the shards of such retroviruses, fragments of the chemical code from which all genetic material is made. It takes less than two per cent of our genome to create all the proteins necessary for us to live. Eight per cent, however, is composed of broken and disabled retroviruses, which, millions of years ago, managed to embed themselves in the DNA of our ancestors. They are called endogenous retroviruses, because once they infect the DNA of a species they become part of that species. One by one, though, after molecular battles that raged for thousands of generations, they have been defeated by evolution. Like dinosaur bones, these viral fragments are fossils. Instead of having been buried in sand, they reside within each of us, carrying a record that goes back millions of years. Because they no longer seem to serve a purpose or cause harm, these remnants have often been referred to as “junk DNA.” Many still manage to generate proteins, but scientists have never found one that functions properly in humans or that could make us sick.

How amazing is that? I mean really think about it: it is incredible. The whole article is great. Related: Old Viruses Resurrected Through DNA – DNA for once species found in another species’ Genes – New Understanding of Human DNA – Retrovirus overview (Tulane) – Cancer-Killing Virus
Continue reading →

Full Body 3-D CT Scan in Under a Minute

Pretty cool new gadget, though probably out of the range of most people’s budget – ‘Super’ scanner shows key detail

The new 256-slice CT machine takes large numbers of X-ray pictures, and combines them using computer technology to produce the final detailed images. It also generates images in a fraction of the time of other scanners: a full body scan takes less than a minute.
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Because the images are 3D they can be rotated and viewed from different directions – giving doctors the greatest possible help in looking for signs of abnormalities or disease.
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At present, it is only being used in one hospital: the Metro Health medical centre in Cleveland, Ohio, which has been using it for the past month.
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the first commercially viable CT scanner, which was invented by Sir Godfrey Newbold Hounsfield in Hayes, United Kingdom at the company’s laboratories and unveiled in 1972. At the same time, Allan McLeod Cormack of Tufts University independently invented a similar machine, and the two men shared the 1979 Nobel Prize in Medicine. “This is a quantum shift from the first CT scanners as it gives a lot more detail,” says Dr Keith Prowse, Chairman of the British Lung Foundation.

Evidence of Short DNA Segment Self Assembly

Tiny DNA Molecules Show Liquid Crystal Phases, Pointing Up New Scenario For First Life On Earth, University of Colorado:

CU-Boulder physics Professor Noel Clark said the team found that surprisingly short segments of DNA, life’s molecular carrier of genetic information, could assemble into several distinct liquid crystal phases that “self-orient” parallel to one another and stack into columns when placed in a water solution. Life is widely believed to have emerged as segments of DNA- or RNA-like molecules in a prebiotic “soup” solution of ancient organic molecules.
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Such DNA polynucleotides had previously been shown to organize into liquid crystal phases in which the chains spontaneously oriented parallel to each other, he said. Researchers understand the liquid crystal organization to be a result of DNA’s elongated molecular shape, making parallel alignment easier, much like spaghetti thrown in a box and shaken would be prone to line up in parallel, Clark said.

The CU-Boulder and University of Milan team began a series of experiments to see how short the DNA segments could be and still show liquid crystal ordering, said Clark. The team found that even a DNA segment as short as six bases, when paired with a complementary segment that together measured just two nanometers long and two nanometers in diameter, could still assemble itself into the liquid crystal phases, in spite of having almost no elongation in shape.

Structural analysis of the liquid crystal phases showed that they appeared because such short DNA duplex pairs were able to stick together “end-to-end,” forming rod-shaped aggregates that could then behave like much longer segments of DNA. The sticking was a result of small, oily patches found on the ends of the short DNA segments that help them adhere to each other in a reversible way — much like magnetic buttons — as they expelled water in between them, Clark said.
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“In essence, the liquid crystal phase condensation selects the appropriate molecular components, and with the right chemistry would evolve larger molecules tuned to stabilize the liquid crystal phase. If this is correct, the linear polymer shape of DNA itself is a vestige of formation by liquid crystal order.”

Related: One Species’ Genome Discovered Inside Another’s – Galactic Dust with the Ability to Reproduce? – DNA Repair Army – Old Viruses Resurrected Through DNA

New Triceratops Ancestor

Alberta palaeontologists discover new dino genus

Scientists from the Royal Tyrrell Museum and the Canadian Museum of Nature have [discovered]… Eotriceratops xerinsularis (pronounced EE-OH-try-sair-ah-tops ZEER-in-soo-lair-iss)… The dino may be an ancestor of the well-know triceratops, and at the very least, is the group’s earliest known member; researchers say the Eotriceratops lived in southern Alberta 68 million years ago.

It is the largest type of horned dinosaur ever discovered in Alberta, and possibly the world.

According to researchers, Eotriceratops likely reached eight or nine metres from nose to tail. It had a massive skull that featured a solid frill (this alone was three metres in length), and three horns – two above each eye, and another, shorter one, perched on its nose.
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Judging by its teeth, the Eotriceratops was a plant-eater, but one that would have been able to ward off predators.

Related: Nigersaurus – Most Dinosaurs Remain Undiscovered – 100 Dinosaur Eggs Found in India – Fossils of Sea Monster

Moringa Oleifera: The Miracle Tree

One thing I enjoy brought about by the web is finding interesting tidbits such as – Moringa Oleifera: The Miracle Tree:

For centuries, the natives of northern India and many parts of Africa have known of the many benefits of Moringa oleifera. Its uses are as unique as the names it is known by, such as clarifier tree, horseradish tree and drumstick tree (referring to the large drumstick shaped pods) and in East Africa it is called “mother’s best friend”. Virtually every part of the tree can be used. Native only to the foothills of the Himalayas, it is now widely cultivated in Africa, Central and South America, Sri Lanka, India, Malaysia and the Philippines. This tree, though little known in the Western world, is nutritional dynamite. There are literally hundreds of uses for this tree.

The immature pods are the most valued and widely used of all the tree parts. The pods are extremely nutritious, containing all the essential amino acids along with many vitamins and other nutrients. The immature pod can be eaten raw or prepared like green peas or green beans, while the mature pods are usually fried and possess a peanut-like flavor. The pods also yield 38 – 40% of non-drying, edible oil known as Ben Oil. This oil is clear, sweet and odorless, and never becomes rancid. Overall, its nutritional value most closely resembles olive oil. The thickened root is used as a substitute for horseradish although this is now discouraged as it contains alkaloids, especially moriginine, and a bacteriocide, spirochin, both of which can prove fatal following ingestion. The leaves are eaten as greens, in salads, in vegetable curries, as pickles and for seasoning. They can be pounded up and used for scrubbing utensils and for cleaning walls. Leaves and young branches are relished by livestock. The Bark can be used for tanning and also yields a coarse fiber. The flowers, which must be cooked, are eaten either mixed with other foods or fried in batter and have been shown to be rich in potassium and calcium.

More internet finds: Sarah, aged 3, Learns About Soap – Plumpynut, Miracle Food – The Avocado – More Nutritious Wheat – Cool Mechanical Simulation System – Aerogels – Weird Solids – Awesome Cat Cam