Stories tagged Life Science

Apr
17
2014

Virus Filter - The fibers of the filter are white and the virus green.
Virus Filter - The fibers of the filter are white and the virus green.Courtesy Björn Syse

Scientists have developed a paper made of cellulose nanofibers that can be used to filter out harmful viruses.

The new filter paper is made with cellulose fibers, a natural component of green plants that gives wood its strength. Cellulose is the main component of plant cell walls, and the basic building block for many textiles and for paper. Cellulose works well for filters because it is inexpensive, disposable, inert, and non-toxic; cellulose is also mechanically strong and stable in a wide range of acid and alkaline conditions.

But normal filter paper can't trap viruses. A virus is tiny, about a thousand times smaller than a human hair. Normal filter paper has pores that are too large to remove tiny viruses. The new nano fiber filter paper is made with cellulose fibers with diameters of less than 100 nanometers. Viruses range in size from 30-50 nanometers, and can be trapped in the nano fiber filter paper.

The research has been conducted at two Swedish universities, Uppsala University and Swedish University of Agricultural Sciences/Swedish National Veterinary Institute.

To read more about this research visit:
http://www.uu.se/en/media/press-release-document/?id=2271&area=3,8&typ=p...

To learn more about nanotechnology, science, and engineering, visit:
www.whatisnano.org

To see other nano stories on Science Buzz tagged #nano visit:
http://www.sciencebuzz.org/buzz_tags/nano

Apr
13
2014

Tiktaalik roseae: Field Museum of Natural History
Tiktaalik roseae: Field Museum of Natural HistoryCourtesy Eduard Solà via Wikipedia
If you missed last week's PBS broadcast of Your Inner Fish, the documentary based on paleontologist-anatomist Neil Shubin's book by the same name, you have another chance to catch up on the first of three segments on the web. It's an excellent opening segment of the 3-part series, but is only available (for free!) right here through April 23, 2014.

The series deals with Shubin's search for the connections we all have with our fishy and reptilian ancestors. His discovery of the remarkable transitional fossil named Tiktaalik roseae on Ellesmere Island in the Canadian Arctic has added great evidence of our ties with our distant piscean relatives. The flat-headed, 375 million year-old Tiktaalik possessed the exact features - such as both lungs and gills, a wrist and neck - that you'd hope to find in a transitional form between swimming fish and land-walking tetrapods.

The next episode, titled Your Inner Reptile airs Wednesday, April 16th on your local PBS station. It's on here in the Twin Cities at 9pm but check your local listing for times in your area.

In the meantime, watch the first episode, and read about some of the reaction to Shubin's find here, here, and here.

LINKS
University of Chicago Tiktaalik roseae page

Mar
05
2014

Virus: Giant viruses are genetically more complex and about 25 percent larger.
Virus: Giant viruses are genetically more complex and about 25 percent larger.Courtesy jiparis
A husband-and-wife-led research team has announced finding an ancient virus laying dormant in Siberian permafrost for more than 30,000 years!

Jean-Michel Claverie and Chantal Abergel of Aix-Marseille University in France and their colleagues cut up pieces of permafrost samples - supplied by scientists from the Russian Academy of Science - and added them to petri dishes of amoebae only to see the one-celled animals ripped apart by unknown viruses. They isolated the attacking, larger-than-usual virus and named it Pithovirus sibericum, because of its resemblance to an earthenware jar. The permafrost samples had been collected from a frozen riverbank in Siberia in 2000.

The discovery brings the total number of known "giant viruses" to three. The extra-large viruses are about 25 percent larger than normal, genetically more complex, and composed of hardier stock.

"Among known viruses, the giant viruses tend to be very tough, almost impossible to break open," said Claverie and Abergel. "Special environments such as deep ocean sediments and permafrost are very good preservers of microbes because they are cold, anoxic and in the dark."

Two other giant viruses Mimivirus and Pandoravirus were also discovered by Claverle and Abergel in the last decade. The latter, in my opinion, is a disturbingly great name for this type of thing. But so far only the pithovirus has been observed in the laboratory infecting contemporary life forms. Luckily, none of them pose a threat to humans, but that's not to say future giant viruses thawed out of frozen environments or released by retreating ice caps won't be.

"I don't see why they wouldn't be able to survive under the same conditions," said Claverie.

Results of the research appear in the Proceedings of the National Academy of Sciences.

SOURCES and LINKS
National Geographic story
Sydney Morning Herald
More about giant viruses

Feb
21
2014

Is obesity in this baby's future?: It could depend on the yogurt's fat content.
Is obesity in this baby's future?: It could depend on the yogurt's fat content.Courtesy Clover_1
Last Christmas, my son's girlfriend introduced me to honey-flavored yogurt, a delicious concoction of creamy sweetness. I've never been a fan of yogurt, but I immediately fell in love with this stuff, and try to keep a container of it on-hand in the fridge at all times. I can't seem to get enough of it.

One of the reasons it's so tasty is because it's made with whole milk which makes it high in fat, and therefore will make anyone who ingests it high in fat, too. Right? Maybe not.

Two new studies seem to point to just the opposite. Several middle-aged men who participated in a Swedish study and consumed high-fat dairy products, were tracked over a 12 year period and showed much less propensity of becoming obese when compared to men who followed a low or no high-fat diet in the same study. The research appeared in the journal Scandinavian Journal of Primary Health Care.

In the second study involving the meta-analysis of 16 empirical studies showed that - despite working under the hypothesis that a diet of high-fat foods leads to higher heart disease risk and contributes to obesity - no evidence supporting the claim was found. Actually, according to the study which appeared in the European Journal of Nutrition, consumption of high-fat dairy products were instead associated with a lower obesity risk.

Non-fat and low-fat yogurts still command a larger portion of the market but on the organic side of the things products with higher saturated fat content is, surprisingly, on the upswing. It's unclear why that is. A previous study involving children also showed that a low-fat diet was more likely to lead to obesity.

"There may be bio-active substances in the milk fat that may be altering our metabolism in a way that helps us utilize the fat and burn it for energy, rather than storing it in our bodies," said Greg Miller, of the National Dairy Council.

Besides the newly associated weight benefits, whole organic milk also contains higher levels of omega-3 fatty acids which help reduce the risk of cardiovascular diseases. It's also speculated that consumption of higher fat content may lead to a greater and faster feeling of being satisfied and full, and lead to a sooner cessation of the urge to eat.

For purely scientific reasons I'll be heading for the refrigerator in a moment to see if that's the case.

SOURCE
NPR story

Feb
14
2014

The Canadian Rockies: Source of a new treasure trove of amazing Cambrian fossils
The Canadian Rockies: Source of a new treasure trove of amazing Cambrian fossilsCourtesy Mark Ryan
Just over a century ago, paleontologist Charles Doolittle Walcott discovered a truly remarkable fossil quarry in British Columbia. The site, known as the Burgess Shale, was found on Mt. Field in Yoho National Park, and contained an abundant amount of fossilized remains of soft-bodied creatures - several new to science - from the Cambrian Period around 505 million years ago. In 1989, paleontologist Stephen Jay Gould detailed the spectacular find and its implications in a book titled, "Wonderful Life: The Burgess Shale and the Nature of History".

Burgess Shale trilobite: Science Museum of Minnesota collection.
Burgess Shale trilobite: Science Museum of Minnesota collection.Courtesy Mark Ryan
This week, a newly discovered fossil site, located in the same shale formation high in the Canadian Rockies but 26 miles southeast of Walcott's quarry, was announced in the journal Nature Communications. The new location, named Marble Canyon, is proving to be another Lagerstätte, a sedimentary deposit of extraordinary and exceptionally preserved fossils. The discoverers report that of the 3000 specimens found so far and representing 55 species, about half are invertebrates also found at the Walcott Quarry, and in some cases are more abundant and better preserved.

"[T]here is a high possibility that we'll eventually find more species here than at the original Yoho National Park site, and potentially more than from anywhere else in the world," said lead author Jean-Bernard Caron, an invertebrate paleontologist at Toronto's Royal Ontario Museum.

So far twenty-two percent of the species discovered at Marble Canyon are new to science. The formation is estimated to be about 100,000 years younger than the original site. China's Chengjiang fossil beds have produced some of the same kinds of animals found at Marble Canyon and is about 10 million years older.

Arthropods (e.g. trilobites) are the most common animals found in the Burgess Shale, and finely preserved fossils from the new site provide remarkable views of neural tissues, retinas, corneas, some internal organs.

Back in 2012, Gaines and his colleagues followed the Burgess shale exposures on foot, trekking across the mountainsides in hopes of finding new fossils sites. What they discovered at Marble Canyon is far more than they could have wished for.

"I think the most profound implication is that the Burgess Shale can't just be the only one that there is," Gaines said. "There's a lot more out there in the Canadian Rockies and other places."

Any fossil remains uncovered at Marble Canyon and at similar sites will only add to our understanding of evolution and how complex life developed during the Cambrian Explosion.

Gallery of new Burgess Shale fossils

SOURCES and LINKS
Nature Communications
ScienceDaily story
"Wonderful Life" by Stephen Jay Gould
LiveScience story
Previous Burgess Shale Buzz story
More about the Burgess Shale

Jan
03
2014

Aging in reverse gracefully: Scientists are successfully changing old lab mice into young ones.
Aging in reverse gracefully: Scientists are successfully changing old lab mice into young ones.Courtesy Andreas-photography
Bob Dylan first sang about it in the chorus of his 1964 song "My Back Pages" when he wrote ""Ah, but I was so much older then/I'm younger than that now"." He reinforced the notion ten years later when he released "Forever Young" in 1974.

It's all about staying young and not growing old - not ageism mind you - but anti-aging.

In a study appearing in a recent issue of the journal Cell, researchers have successfully reversed the aging process by turning a 2 year-old into one that resembles one that's a mere 6 months old. In human terms this would be equivalent to turning a 60 year-old back into a 20 year-old.

Dr. David Sinclair, professor of genetics at Harvard Medical School, and his team of researchers injected aging mice for a week with a compound known as nicotinamide adenine dinucleotide (NAD+), a natural chemical made from young cells. As mammalian cells age, NAD+ production drops by half causing mitochondrial dysfunction, and the processing of oxygen to fall off. Cells then become vulnerable to the various ailments that aging attracts. But in the treated older mice the cells began to take on the vitality and appearance of young mice.

Sinclair will next try administering NAD+via the drinking water used by lab mice to see how things go . If it has the same effect on the mice's cells, someone call Ponce de Leon because we could be talking about an actual Fountain of Youth!

Since NAD+ is a naturally produced compound, the concern for harmful after-effects is slight. Human trials could begin as early as next year - but it's not going to be cheap - somewhere in the neighborhood of $50,000 a day!

If I win the lottery in the next few months, I'll be first in line to become 20 years-old again, but only if I can retain my experience and any wisdom I may have acquired along the way. But if not, I guess I'll just start humming Dylan's "Knocking on Heaven's Door."

Time magazine story
Guardian story
BBC Health News

Dec
28
2013

Restoration of Haplocanthosaurus: a Late Jurassic sauropod whose remains are found in Colorado, Utah, and Wyoming.
Restoration of Haplocanthosaurus: a Late Jurassic sauropod whose remains are found in Colorado, Utah, and Wyoming.Courtesy FunkMonk via Wikimedia Commons
The partial remains of a somewhat rare sauropod dinosaur have been discovered in Old Snowmass, near Aspen, Colorado. Paleontologist John Foster of the Museum of Western Colorado in Grand Junction said that fossils of a Haplocanthosaurus were found by college student Mike Gordon in 2005 on land owned by his mom and stepfather. If you remember, Snowmass was the site near Aspen where a large collection of mammoths, mastodons, and other Ice Age mammals were uncovered back in 2010. This latest discovery is about six miles from the other site but in a much, much older rock layer. Foster said the Lower Morrison Formation, from where Haplocanthosaurus remains were collected dates back to the Late Jurassic, about 155-152 million years ago.

It's a very exciting find because few specimens of Haplocanthosaurus exist. The first were also found in Colorado, in Garden Park near Canon City, by Carnegie Museum of Natural History paleontologists William H. Utterback and John Bell Hatcher in 1901. The type specimens (H. priscus and H. utterbacki) were described by Hatcher in 1903. The fossils were prepared under the direction of chief preparator, Arthur S. Coggeshall.

Mounted skeleton of Haplocanthosaurus delfsi: Cleveland Museum of Natural History
Mounted skeleton of Haplocanthosaurus delfsi: Cleveland Museum of Natural HistoryCourtesy ScottRobertAnselmo via Wikimedia Commons
Compared to its larger and heavier long-necked, small-headed cousins such as Apatosaurus and Diplodocus, the Haplocanthosaurus was a relatively small-sized sauropod dinosaur with a length of 35 to 40 feet and weighing maybe 14 tons. While most sauropods have hollow spaces in their backbones, a distinguishing characteristic of Haplocanthosaurus is the solidness of its vertebrae which Foster confirmed by doing a scan of the fossil bones at a local hospital in Grand Junction.

Haplocanthosaurus hindlimb: Science Museum of Minnesota
Haplocanthosaurus hindlimb: Science Museum of MinnesotaCourtesy Mark Ryan
The only mounted specimen of Haplocanthosaurus is the referred species (H. delphsi) on exhibit at the Cleveland Museum of Natural History in Ohio. No skull of the sauropod has ever been found so the head is just a fabricated guess. Other post-cranial remains exist, including some here at the Science Museum of Minnesota that were collected in Wyoming, but in general fossils of the dinosaur are rare. Material from only 10 individuals are known.

So far the Old Snowmass site has provided some vertebrae, ribs and a pelvis. but the landowners have been very accommodating in allowing the museum access to the dig site, and Foster hopes to find more Haplocanthosaurus bones - maybe even some skull material - in the coming summer season.

SOURCES and LINKS
Aspen Times story
More Haplocanthosaurus info
Osteology of Haplocanthosaurus by John Bell Hatcher
Jurrassic West: The Dinosaurs of the Morrison Formation and Their World by John Foster

Dec
09
2013

Charlie Darwin: The schoolbook victory in Texas obviously makes him feel like Charlie Sheen.
Charlie Darwin: The schoolbook victory in Texas obviously makes him feel like Charlie Sheen.Courtesy National Portrait Gallery
Last month, on November 22nd, while many people in the country were observing the 50th anniversary of president John F. Kennedy's assassination by shots fired from the Texas School Book Depository, there was another significant event happening that day involving Texas schoolbooks. That same Friday, despite objections and obstructionist tactics by creationists, the Texas Board of Education approved several public school science textbooks that included full coverage of evolution and climate change. The vote came late in the day and although the creationist faction did manage to make the adoption of two biology books contingent on a committee ruling regarding some alleged "flaws" in the text, the Texas Freedom Network (TFN), a watchdog group instrumental in countering the irrational creationist attacks, expects the passage to stand.

“It’s hard to overstate the importance of today’s vote, which is a huge win for science education and public school students in Texas,” said Kathy Miller, TFN's president. “Four years ago this board passed controversial curriculum standards some members hoped would force textbooks to water down instruction on evolution and climate change. But that strategy has failed because publishers refused to lie to students and parents demanded that their children get a 21st-century education based on established, mainstream science.”

SOURCES
Dallas Morning News story
Evolution is True article

Dec
06
2013

Victim of mass extinction: Will current species suffer a similar fate due to current environmental trends?
Victim of mass extinction: Will current species suffer a similar fate due to current environmental trends?Courtesy Mark Ryan
A new and troubling paper from the Committee on Understanding and Monitoring Abrupt Climate Change and its Impacts predicts possible and somewhat grim outcomes for some of Earth's natural systems from climate change that could rival the extinction event of the non-avian dinosaurs at the end of the Cretaceous Period 65 million years ago.

The abrupt impact could be coming faster than previously expected and would negatively affect human and physical climate systems as well. The document warns that the abruptness of the changes could be unanticipated and could find us unprepared to deal with them

Records of past climate preserved in tree rings, ice cores, and ocean sediments show that the atmosphere contains higher levels of carbon dioxide than it has in a very long time. Carbon emissions from human activity continue to add to this rising concentration. Other activities including deforestation and resource extraction place additional environmental pressures on our climate and other natural systems.

At the end of the Cretaceous, all species of non-avian dinosaurs, along with the megafauna of flying and swimming reptiles were wiped off the face of the Earth. Many dinosaur species showed signs of decline even before the Chicxlub asteroid delivered the final kibosh on their existence.

Dr. James W.C. White, a professor of Geological Sciences and of Environmental Studies at the University of Colorado at Boulder chaired the committee which included more than a dozen earth scientists and ocean researchers from universities in both Canada and the United States, and from the National Academy of Science.

A prepublication copy of the entire 201-page paper is available to read without charge on the National Academies Press page. You can also download it for free although it was a little tricky getting it to my computer.

SOURCE
MinnPost story

Dec
01
2013

Three shiitake mushrooms: Some fungi create their own breeze to disperse spores.
Three shiitake mushrooms: Some fungi create their own breeze to disperse spores.Courtesy apc33
According to a new study presented at the recent Annual Meeting of the American Physical Society's Division of Fluid Dynamicsin Pittsburgh, Pennsylvania, many species of mushrooms create their own breezes to help disperse their spores. Most times, mushrooms rely on wind to spread their offspring around the environment. But using indirect measurements, along with high-speed video and scaling analysis of fluid mechanics, researchers from Trinity College and UCLA have shown that before releasing their spores, some fungi create their own air movement through the release of water vapor that produces a convective dynamic to cool the air and get it moving. As slight as the breeze may seem, it's enough to move the spores to an adequate distance away from the mushroom parent.

SOURCE
Scientific American story