T cell activation
Courtesy NIH
Vitamin D necessary to fight disease
When members of our body's immune system called T cells encounter germs and viruses they change into "killer cells" and "helper cells".
A new study published today in Nature Immunology explains why Vitamin D is so important to our health.
"When a T cell is exposed to a foreign pathogen, it extends a signaling device of 'antenna' known as a vitamin D receptor, with which it searches for vitamin D," ...If there is an inadequate vitamin D level, they won't even begin to mobilize."
Most people lack enough Vitamin D
According to a recent study in the Archives of Internal Medicine, found that "77 percent of U.S. adults and teenagers surveyed did not have the estimated minimum healthful level of 30 nanograms per milliliter in their blood. And just three percent of blacks in the survey were getting enough of the vitamin."
Cod liver oil
While living with my parents, I was given a table spoon of cod liver oil, a bowl of oatmeal, and a half of an orange for breakfast each day. I might have to consider adding cod liver oil to my diet again (most people think it tastes nasty).
Tags : Asteroid found guilty of killing dinosaurs!!
in Earth and Space Science, Life Science, and Biological Populations Change Over Time
What sent the dinosaurs packing?: The number one suspect, a gigantic asteroid, has finally been convicted of the crime.
Courtesy Mark RyanAfter studying all available evidence and listening to alternative theories (and despite no eyewitnesses), a panel of 45 international scientists has decided it was a huge asteroid that killed all the non-avian dinosaurs some 65 million years ago.
The asteroid, described as a 7 mile-in-diameter chunk of space rock, has been the prime suspect in the ruling reptile’s demise ever since scientists Luis Alvarez and his son Walter first identified a one-inch layer of iridium in Late Cretaceous-age rock exposures throughout the world. The layer was located exactly at the point in the rock record where the Cretaceous period ended, and the Tertiary period began (K-T boundary). 
Smoking gun for dinosaurs' demise: K-T Boundary with 1-inch iridium layer (arrow) exposed 10 miles west of Trinidad, Colorado. The element iridium is very rare on Earth but concentrated in meteors and comets. The same iridium layer is found in several exposures around the world, and corresponds in age with the Chicxulub meteor crater in Mexico's Yucatan Peninsula. The layer marks the end of the Cretaceous era, and no non-avian dinosaur remains have ever been found above the boundary. The coal layers above and below the iridium suggests a swampy environment when the layer was laid down in this area of Colorado.
Courtesy Mark RyanThey predicted a meteor impact crater of the same age would be found as the source of the iridium since the element is rare on Earth but common in outer space. Then in 1990 their predictions were verified when the Chicxulub impact crater was discovered in Mexico.
Although the impact site was mostly submerged off the north coast of the Yucatan Peninsula, samples taken from it dated to the end of the Cretaceous period. This and other corroborating evidence helped bolster the killer asteroid hypothesis as the primary theory for the extinction event that wiped out 70-75 percent of life on Earth including non-avian dinosaurs, and other large reptiles. The asteroid is estimated to have slammed into Earth traveling 10 times faster than a rifle bullet, and released the energy of a billion atomic bombs. The impact instantly vaporized a large area of terrain, and sent an explosion of dust and rocky debris up into space, much of which fell back into the atmosphere in a fiery rain. It left a crater 110 miles across, and a cloud of dust circling the planet for weeks. The diminished sunlight would have disrupted the environment severely, including the food chain. Mammals and other smaller creatures were able to survive across the boundary and flourish in later periods.
But not everyone was convinced by the evidence. Other causes for the mass extinction, such as extreme volcanism in India, falling sea levels, disease epidemics, and even fungal infection were all tossed around as possible culprits.
But in the end it seems the evidence implicating the asteroid in the K-T* extinction event was just too strong, and after much deliberation, the impact has been determined as the official cause of death. The panel published its decision in the latest issue of Science.
*“K-T” stands for Cretaceous-Tertiary, however, use of the term Tertiary is being discouraged now, and the time span it occupied has been replaced with the Paleogene and Neogene periods. So a more proper, up-to-date term would be Cretaceous-Paleogene or K-Pg extinction event.
LINKS AND SOURCES
More about dinosaur extinction
BBC story
Impact theory counterview
Missing Link - Not
Darwinius masillae
Courtesy University of OsloPerhaps taking advantage of the Darwin publicity last year (200th birthday), a scientific paper was published revealing Ida, a 47 million year old fossil classified Darwinius masillae.
The study's lead author, Jørn Hurum of the University of Oslo, variously called the fossil the holy grail of paleontology and the lost ark of archeology. A two-hour documentary called "The Link" was on the History Channel and a book with the same title hit bookstores.
One million dollars
How big money became mixed with science is described in the Guardian post titled Deal in Hamburg bar led scientist to Ida fossil, the 'eighth wonder of the world'.
Now that money has been made, it is time for the scientific process (peer review).
John Fleagle, a professor at Stony Brook University, in New York state, who reviewed the paper for the journal, agrees that the fossil is not a lemur. But Ida's full significance would not be known until other scientists had seen the paper. "That will be sorted out, or at least debated extensively, in the coming years."
Confirmed: Fossil Ida is not a human ancestor
In a paper in the Journal of Human Evolution, Chris Kirk strongly argue(d) that Darwinius is not one of our ancestors. Science blogger, Brian Switek, also explains why ... That "Ida" is Not Our Great-Great-Great-Great-Etc. Grandmother. Dissenting scientists are awaiting a response from Jørn Hurum.
How science should be done
I am reminded of another case where the media was used to hype a story before it was properly reviewed by others. I wrote about it here: Jesus and family found in tomb? What moral is to be learned here?
Don't announce discoveries through the media, but through the tried and tested peer-review process.
Athletes like those who won medals at the recent Winter Olympics train intensely for their sport. When most of us think of training, we probably think only of physical exercise, but winning athletes also need to master the mental challenges of competition, which can be especially intense during the Olympic games. After all, the world is watching and nothing short of national pride is on the line.
Listen to the short sound pieces in this New York Times interactive graphic and you'll realize that the distance between winners and losers at the Olympic games is often less than an instant. Being mentally focused and prepared can make all the difference. To help them train, many athletes (including all of the US team) work with Sports Psychologists, mental health experts who help them to prepare for the distraction of crowds and the pressure of the moment. What does mental training involve? Athletes complete exercises in visualization, breathing, body control, and energy management to help them focus so they don't choke under pressure.
What about the mental implications of winning and losing? Psychologists (and economists!) who are interested in knowing more about what makes people happy have used the Olympic games as a kind of laboratory - looking at athletes who take first place and comparing them to those who don't.
As you might guess, winning a Gold medal feels pretty good, and athletes who take first seem to be pretty happy about it. But scientists found an unexpected result in their study on winning, losing, and happiness when they compared silver and bronze medalists - it seems that third place finishers are, on average, happier than those who come in second. Researchers learned this by watching interviews with Olympic athletes at the 1992 summer games and recording words and phrases that they used to describe how they were feeling. They also watched recordings of the facial expressions of the athletes on the podium, and concluded that while most Bronze medalists looked giddy, Silver medalists often seemed disappointed.
Why would you be happier with a third place title than second? Researchers point to a phenomenon called "counterfactual thinking" - in short, it means those in second place are plagued by thoughts of "what might have been" while bronze medalists are relieved that they placed at all. Second place finishers are thinking of the one tiny mistake that cost them first place, while third place finishers are relieved that they didn't make one mistake too many.
This phenomenon is not exclusive to Olympic athletes. We all compete in one sense or another, and have all probably dealt with moments of winning and losing, which is probably part of why we enjoy watching sports games.
Click here for more Buzz stories on science and the Winter Olympics.
Frozen in time: Unique fossil shows snake coiled among nest of dinosaur eggs and titanosaur hatchling.
Courtesy PLoS Biology
Diagram of fossil
Courtesy PLoS BiologyCheck out this amazing fossil showing the remains of a snake coiled around a nest of dinosaur eggs, including a nearby titanosaur hatchling. The fossil was found 26 years ago in northwestern India, and was originally thought to contain remains of eggs and baby dinosaur bones. But recent re-evalutions revealed some of the bones were actually those of a new species of snake named Sanajeh indicus. The incredible 67 million-year-old fossil is the first of its kind, and suggests that snakes preyed on dinosaurs, just as they prey on birds today. A newly hatched titanosaur would have been easy pickings for the 11.5 foot S. indicus, but an adult titanosaur - which grew to more than 100 feet in length - would have been another story. Scientists think the unique Cretaceous fossil resulted from an ancient landslide that buried the snake just when it was about to go after its next meal. Here's a photo of the incredible fossil and along with a diagram of what it contains. You can read the whole story at PLoS Biology where the research has been published.
Don't Leaf Me Behind!
in Diversity of Organisms and Biological Populations Change Over Time
An Instant Classic: Hey, Aesop, what if I told you Mr. Hare won the race?
Courtesy Milo Winter
You’re probably familiar with Aesop’s classic fable The Tortoise and the Hare: Mr. Hare challenges Mr. Tortoise to a foot race. Mr. Tortoise accepts. Mr. Hare dashes from the start line, but stops just before the finish line to take a nap. In the meantime, Mr. Tortoise plods along to win the race!! The moral of the story? University of Minnesota professor and Institute on the Environment resident fellow, Dr. Peter Reich’s award-winning take on the fable may surprise you.
Dr. Peter Reich: This guy studies leaves for a living.
Courtesy Regents of the University of Minnesota
Dr. Reich studies leaves. In particular, Dr. Reich has discovered three characteristics of leaves that allow researchers to identify where and how plants live: longevity, productivity, and nitrogen content. Longevity measures how old a leaf lives. Did you know leaves in the tropics live only 5-6 weeks whereas Canadian spruce leaves can live up to 18 years old? Productivity measures how much sugar the leaf makes (yes, leaves make sugar called “glucose,” which nearly every animal uses to fuel their body – that’s why your momma tells you to eat your vegetables!). Finally, nitrogen is like a vitamin for plants: they need it to grow big and strong. How much nitrogen a leaf has is important because it determines how much energy a plant can make.
Canadian Spruce: If these leaves were human, they could be legal adults!
Courtesy Steven J. Baskauf
Tropical Leaves: These guys may look BIG, but they are not going to be around for long.
Courtesy Flickr
What about the moral of The Tortoise and the Hare? Dr. Reich’s research says there are basically two types of leaves: ones that are like Mr. Tortoise and ones like Mr. Hare. Tortoise-like leaves work slowly, but steadily. They’re the marathon runners of the leaf world. Hare-like leaves work really fast! But they can’t keep it up for long. They’re sprinters. Could you run a marathon at your top sprinting speed? Probably not, and neither can leaves be both ultra-fast and long-lasting at the same time. Instead, leaves “tradeoff” speed for endurance. Like human runners, leaves don’t have to be all fast and short-lived or all slow and long-lived; they can fall somewhere inbetween and be medium speed and medium-lived.
So who cares about marathon and sprinting leaves anyway? Lots of people! Dr. Reich just won the BBVA Frontiers of Knowledge Award in recognition of this important research. Being able to group the thousands of plants out in the world into a handful of groups is allowing scientists to do incredible research that can be used around the world.
For example, Dr. Reich’s newest research is looking at the different responses of tortoise-leaves versus hare-leaves to changing environments, such as higher levels of carbon dioxide in the air caused by climate change. As each generation of leaves reproduces, new genetic combinations are created. New genetic traits that are helpful to the plant’s survival are passed on to the next generation. The more genetic combinations created, the better chance a species has of “finding” the right traits in a changing environment. This is where Dr. Reich’s interpretation of the moral of The Tortoise and the Hare may surprise you: because hare-leaves have fast, short lives, they reproduce more genetic combinations and are better able to deal with change. Tortoise-leaves will struggle more to adapt. That is, for leaves, slow and steady does not always win the race!
Want to know more?? Dr. Reich recently gave a lecture as part of the Institute on the Environment’s Frontiers on the Environment series. You can hear it here.
There's lots of buzz (normal buzz, not our patented Science Buzz) on the 'net today about the "Bloom Box" featured on 60 Minutes this weekend.
It seemed to me to be a pretty junky interview and feature, but I'm intrigued nonetheless; the Bloom Box is supposed to be an efficient new fuel cell that would allow electricity to be produced at the site where it will be used, eliminating transmission losses, and efficiently converting fuel to energy.
It runs on hydrocarbons, but it sounds like it's pretty omnivorous as to the kinds it can use (so natural gas works, but so would carbon-neutral biogas, etc), and it presumably emits CO2, only much less of it than traditional power generation. (The interview was extremely fuzzy on that aspect, but the Atlantic's article about Bloom from a month ago says that the device does release CO2.)
Something like 20 companies in California are already testing Bloom Box units, and the people making them to have attracted a ton of money, so the technology doesn't look quite so pie in the sky as a lot of other energy inventions we're supposed to get excited about.
The guy behind the Bloom Box believes that, inside of a decade, you'll be able to have one in your basement for something like $3000 dollars. More expensive than a used Super Nintendo, but, as far as major appliances go, pretty darn cheap. We'll see about that, sir... The featured skeptic seems to think that, if we see it at all, we'll see it coming from a company like GE, not Bloom Energy.
Here's the 60 Minutes piece:
The whole operation has been kept pretty secret until recently, and supposedly there will be more details coming soon.
But until then... What do you think? Ho-hum? Hoax? Or is this something to be excited about?
Nike's new prototype- the retro model: The running foot is soooo 2 million years ago, but you wait long enough and everything comes back.
Courtesy perpetualplumHave you ever run barefoot? It’s great! I’ve never really thought about why I like it, but some really cool biomechanics research coming out of Harvard suggests that there may be some evolutionary reasons for my enjoyment. Homo sapiens and our early ancestors have engaged in endurance running for more than a million years, and have done so with no shoes, or with minimal footwear (sandals, moccasins, etc.). The researchers wanted to know how these early humans (and some humans today, let’s not forget) were able to run comfortably and safely sans shoes. Daniel Lieberman, professor of human evolutionary biology at Harvard, and his crew found that barefoot runners land either on the balls of their feet or mid-foot (the balls of their foot and heel at the same time), while shod runners land on their heels, or heel-strike, to use the lingo. This makes sense when you look at the structure of our feet; our strong, high arch acts like a spring when we run, and this spring can only be loaded when we first land on our forefoot. It wasn’t until the 1970’s when running shoes came equipped with highly cushioned heels that it began to seem normal to run heel-to-toe. (Some research even suggests that not just running shoes, but all shoes are detrimental to our foot health)
With some super advanced equipment (Harvard undergrads are so lucky), Lieberman saw how much of an impact heel-striking causes. When you heel-strike, your foot comes to a dead stop, causing your foot and leg to have to absorb all of that kinetic energy (a force which is 2-3 times your body weight). When you land on your forefoot, however, some of that kinetic energy is converted into rotational energy as your foot goes from toe to heel. This is obviously much less jolting. The researchers hypothesize that heel-striking is the cause of a lot of running-related repetitive stress injuries, and by avoiding heel-striking, more runners could see less of these types of injuries.
If you want to try running barefoot (and I recommend), Lieberman cautions that you shouldn’t just jump into it (especially if it is February in Minnesota), but rather start slowly. Running barefoot uses different muscles and it takes a little while for your feet to get used to it if you’ve been a shod runner your whole life. Who knows, your feet may be your new favorite shoes.
Rex in the hen house
Courtesy Mark RyanA new study came out last week that appeared destined to shake up the current line of thought that birds descended from dinosaurs. Birds share common traits with some dinosaurs, including furculas (wishbones), hollow bones, and other skeletal features, which scientists have interpreted to mean the former descended from the latter. But now a new study by researchers at Oregon State University, it may have happened just the opposite way.
"We think the evidence is finally showing that these animals which are usually considered dinosaurs were actually descended from birds, not the other way around," said John Ruben, a professor of zoology at OSU, and the study’s lead author.
The study involved the fossil of a Microraptor, a dromaeosaurid dinosaur with evidence of feathers on both its arms and legs. Studying the skeletal remains, Ruben and his colleagues constructed 3-dimensional models that they tested for flight capabilities. Their study showed Microraptor’s structure better suited to be glider rather than a flyer. From this Ruben extrapolated that it made more sense that Microraptor descendents came down from the trees and eventually evolved into flightless birds we call dromaeosaurs or raptors.
"Raptors look quite a bit like dinosaurs but they have much more in common with birds than they do with other theropod dinosaurs such as Tyrannosaurus," he said. The study appears in the journal for the Proceedings of the National Academy of Science (PNAS).
Sounds good at first, and I have to admit I was smitten with the idea. But not everyone feels the same way.
Over at the Smithsonian’s Dinosaur Tracking blog, freelance science writer Brian Switek has pointed out that Ruben’s proclamation is “actually only a commentary, or the equivalent of an opinion piece.”
He then goes on to point out some of the flaws in Ruben’s argument, particularly the uncertainty surrounding Microraptor’s place in the evolution of flight, and the lack of reasonable evidence that Velociraptor wasn’t a dinosaur. Switek doesn’t think Ruben’s claim stands up to scrutiny.
But what annoys Switek most is how the media inundates the various outlets with this kind of science news, giving it wide distribution and often, undeserved credibility.
“In this increasingly fragmented media landscape, knowledgeable science writers who recognize a fishy story when they see one are getting outnumbered. More often, websites and newspapers simply reprint press releases issued by universities and museums (science writers call this “churnalism”), and this policy sometimes lets questionable science slip through the cracks.” – Brian Switek
One of the reasons for this is the internet. There's just a huge amount of time and space that requires constant feedings of content now. It does make things difficult to sort through. There have been times I’ve begun researching some new science story to post on Science Buzz only to become frustrated with details that don’t seem to add up, confusing statements, info that counters other info, and outright misinformation. Some of it may be due to the writer(s) not being able to properly articulate or distill a particular idea or hypothesis for the general reader (I know I suffer from this occasionally). Sometimes it’s due to the fact that many science writers lack access to the papers themselves (most science journals require paid subscriptions to access anything beyond an abstract of the story), so writers are left with relying on press releases and abstracts or another writer’s thoughts on the subject (like I’m doing here). But other times it ends up being that there’s no real story at all, just a rehash of something from months or years ago that somebody figures needed to be in the headlines again.
To this end, paleontologist Dave Hone over at his Archosaur Musings blog recently posted “A guide for journalists reporting on dinosaur stories” that deals with some of issues raised here. It’s worth reading.
Science Buzz has also covered science writing issues in previous posts.
How to read/write science news
Bad Science Journalism
SOURCE and MORE INFO
ScienceDaily.com story
Microraptor gui: Bird or Dinosaur
Origin and Evolution of Birds
What is it?: It's... ah... you know, whatever.
Courtesy ReytanRoll up your sleeves and prepare a glass of filtered water, Buzzketeers, because it’s time to learn about the Guinea worm. It’s time to learn about the Guinea worm… hard!
In case the title of this post didn’t spoil it for you already, or if your mother printed out the page but cut off the title, or in case your eyes just don’t read letters that big, the Guinea worm grows to be up to three feet long. Inside you. And even though everything that enters my body must first pass through flame, it still freaks me out.
The parasitic guinea worm, or dracunculiasis (which means “afflicted with little dragons”—you’ll see why in a second), was once found in 20 countries across Asia and Africa, but improved sanitary conditions have reduced its range to just 4 countries in Sub-Saharan Africa. Which is cool, because the Guinea worm is super gross and bad, but not good enough, because the Guinea worm is super gross and bad.
The worm works like this: little worm larvae swim around in puddles and ponds until they get eaten by teeny, tiny crustaceans called copepods (sort of like little shrimp). They live and grow inside the copepods until the copepods get swallowed by people drinking unfiltered water. (Just to be clear, this isn’t just any unfiltered water. If you’ve got electricity to power a computer to read this, there’s pretty much zero chance that there are any worm-carrying copepods in your water. If it came from a tap and not a puddle, you’re probably cool. And even if it came from a puddle, you’re probably still cool.) The copepods get dissolved in the drinkers’ stomach acid, but not the baby worms, which then move from the stomach to the abdominal cavity. There, the worms mate. The male worms die and get absorbed, but the female worms wriggle their way deeper into the body, and grow. And grow and grow. Until they’re about three feet long. They live inside their human host for a year, and then they form a blister somewhere on the surface of the person’s body. When the blister bursts, the female worm emerges just a little bit. The worm releases chemicals that cause the blister to have a very painful burning sensation, and when the host puts the affected area in water to cool it, the worm releases hundreds of thousands of worm larvae into the water, where the cycle can begin again.
As if that whole experience weren’t uncomfortable enough, the treatment isn’t a whole lot better. Because there’s no medicine for Guinea worm infection, the adult worm itself must be removed. The way to do that is to grab the exposed bit of the worm and wrap it around a twig or a piece of cloth, and then twisting the twig. But it has to be done slooooowly so as to not break the worm while it’s still inside your muscles—the process, which is said to be extremely painful, can take up to a month before the worm is fully removed. It’s thought that the ancient for medicine, a snake wrapped around a rod may have been inspired by this procedure.
So, you know… ouch, blech, ouch.
Becoming infected once confers no protection from getting infected again, so people can get Guinea worms over and over again, and in addition to being painful, the blister the worm creates can make the sufferer vulnerable to more dangerous infections.
The good news is that preventing infection is relatively simple; infected people shouldn’t wash in water that will be used for drinking, and simple filters can keep people from ingesting the copepods that carry the worm larvae.
President Jimmy “Billy who?” Carter’s non-profit organization, The Carter Center, has been working for the last 20 years to eradicate the parasite. Despite some pretty significant barriers, it is expected that dracunculialisis will be the second disease, after smallpox, to be completely eradicated through human efforts. (Here’s a recent article on that.)
From what I’ve read (and what the Carter Center says), it looks like humans are the Guinea worm’s only host. So it seems to me that eradicating the infection would cause the extinction of the species. Think about that for a second. Usually sciencey types are pretty much completely against driving other organisms to extinction. But it seems like this one… considering how it pretty much only makes life worse for people who are already dealing with some serious challenges… should maybe… maybe… go extinct? I mean, obviously, right? But try that one on for size; I bet you haven’t often said to yourself that you’re cool with something going extinct. It’s a strange experience.
(If you just can’t deal with it, Here’s a website devoted to saving the Guinea worm. It’s satire, but subtle enough that you could probably play along. But, um, remember that sometimes the Guinea worm emerges from the eyes or genitals of its host. Just saying.)
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