Tadpoles with eyes in their tails see the light

Transplanted organs can distinguish between colors

By Tina Hesman Saey

Web edition: February 28, 2013

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SEEING WITHOUT EYES

A tadpole with no eyes in its head can nonetheless see from an eye transplanted to its tail, provided that nerves from the eye wire into the spinal cord.

Credit: D. Blackiston and M. Levin/Tufts University

If someone shouts ?look behind you,? tadpoles in Michael Levin?s laboratory may be ready. The tadpoles can see out of eyes growing from their tails, even though the organs aren?t directly wired to the animals? brains, Levin and Douglas Blackiston, both of Tufts University in Medford, Mass., report online February 27 in the Journal of Experimental Biology.

Levin and Blackiston?s findings may help scientists better understand how the brain and body communicate, including in humans, and could be important for regenerative medicine or designing prosthetic devices to replace missing body parts, says G?nther Zupanc, a neuroscientist at Northeastern University in Boston.

Researchers have transplanted frog eyes to other body parts for decades, but until now, no one had shown that those oddly placed eyes (called ?ectopic? eyes) actually worked. Ectopic eyes on tadpoles? tails allow the animals to distinguish blue light from red light, the Tufts team found.

Levin wanted to know whether the brain is hardwired to get visual information only from eyes in the head, or whether the brain could use data coming from elsewhere. To find out, he and Blackiston started with African clawed frog tadpoles (Xenopus laevis) and removed the normal eyes. They then transplanted cells that would grow into eyes onto the animals? tails.

The experiment seemed like a natural to test how well the brain can adapt, Levin says. ?There?s no way the tadpole?s brain is expecting an eye on its tail.?

Expected or not, some of the tadpoles managed to detect red and blue light from their tail eyes. The researchers placed tadpoles with transplanted eyes in chambers in which half of the chamber was illuminated in blue light and the other half in red light. A mild electric shock zapped the tadpole when it was in one half of the dish so that the animal learned to associate the color with the shock. The researchers periodically switched the colors in the chamber so that the tadpoles didn?t learn that staying still would save them.

Tadpoles in which nerves from the tail eye had grown to connect to the spinal column were able to learn the color-shock association and swim away from the light that accompanied a shock. Tadpoles whose tail eyes had connected to the stomach or some other part of the body did not learn the association. Neither did tadpoles with no eyes. The finding suggests that visual information from the eye travels up the spinal cord to the brain, which can process it, Levin says.

That result was a surprise, Zupanc says, because previous research had suggested eyes need to be directly connected to the brain to transmit visual information. Somehow the brain is able to distinguish the color messages from other data travelling through the spinal cord. All of those messages arrive as electrical signals that look alike to the experimenters, but Levin and Blackiston?s study suggests the brain can tell the difference.

Learning how the brain sorts visual information from other types of data may be important, Levin suggests, in designing artificial eyes or correcting some forms of blindness in which the brain doesn?t process visual information correctly.

Source: http://www.sciencenews.org/view/generic/id/348633/title/Tadpoles_with_eyes_in_their_tails_see_the_light

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Mayo Clinic finds steroids may shorten hospital stay for pneumonia patients

Public release date: 28-Feb-2013
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Contact: Robert Nellis
newsbureau@mayo.edu
507-284-5005
Mayo Clinic

ROCHESTER, Minn. Patients with pneumonia may spend fewer days in the hospital if they are given steroids along with antibiotics and supportive care. That's the finding of a Mayo Clinic analysis of eight randomized-controlled clinical trials involving more than 1,100 patients. The results appear in the March issue of the Journal of Hospital Medicine.

"Given that the average hospital stay for community-acquired pneumonia can range from nine to 23 days, the prospect of speeding recovery, even by a day or two, is helpful," says co-author M. Rizwan Sohail, M.D., a Mayo infectious disease specialist.

Pneumonia is a major health risk, especially in the elderly, the very young and those with chronic lung diseases. Five percent to 15 percent of pneumonia patients die from it, depending on its severity and the treatment administered, recent studies report.

Mayo researchers reviewed eight clinical trials conducted from 2000 to 2011. Most of the research studied patients between 60 and 80. While steroid use didn't prevent deaths, for those who survived the pneumonia, it reduced their hospital stays an average of 1.21 days.

The researchers say that while the findings are significant, the data were not strong enough for them to recommend routine use of steroids for pneumonia patients; more study is needed. They add that continuing any steroids patients may already be taking is reasonable.

The study was led by Majid Shafiq, M.D., a former Mayo Clinic researcher currently at Johns Hopkins University.

A similar, but unrelated study by A.R. Khan, M.D., involving researchers at Mayo Clinic and other institutions, found that use of certain lipid-lowering medicines, commonly referred to as statins, may have a role in reducing the risk of developing community-acquired pneumonia and associated mortality. That study, published last month in PLOS ONE, reviewed 18 clinical trials. The evidence was considered less reliable due to design issues, bias and other factors in the original studies.

Vaccination remains the most powerful tool in infection prevention, researchers say. The Centers for Disease Control and Prevention recommends that all adults 65 or older should receive the pneumonia vaccine and that anyone 19 or older with risk factors such as immune deficiency or chronic lung disease also should get it.

###

About Mayo Clinic

Mayo Clinic is a nonprofit worldwide leader in medical care, research and education for people from all walks of life. For more information, visit www.mayoclinic.com and www.mayoclinic.org/news.

Journalists can become a member of the Mayo Clinic News Network for the latest health, science and research news and access to video, audio, text and graphic elements that can be downloaded or embedded.

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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.

Public release date: 28-Feb-2013
[ | E-mail | Share ]

Contact: Robert Nellis
newsbureau@mayo.edu
507-284-5005
Mayo Clinic

ROCHESTER, Minn. Patients with pneumonia may spend fewer days in the hospital if they are given steroids along with antibiotics and supportive care. That's the finding of a Mayo Clinic analysis of eight randomized-controlled clinical trials involving more than 1,100 patients. The results appear in the March issue of the Journal of Hospital Medicine.

"Given that the average hospital stay for community-acquired pneumonia can range from nine to 23 days, the prospect of speeding recovery, even by a day or two, is helpful," says co-author M. Rizwan Sohail, M.D., a Mayo infectious disease specialist.

Pneumonia is a major health risk, especially in the elderly, the very young and those with chronic lung diseases. Five percent to 15 percent of pneumonia patients die from it, depending on its severity and the treatment administered, recent studies report.

Mayo researchers reviewed eight clinical trials conducted from 2000 to 2011. Most of the research studied patients between 60 and 80. While steroid use didn't prevent deaths, for those who survived the pneumonia, it reduced their hospital stays an average of 1.21 days.

The researchers say that while the findings are significant, the data were not strong enough for them to recommend routine use of steroids for pneumonia patients; more study is needed. They add that continuing any steroids patients may already be taking is reasonable.

The study was led by Majid Shafiq, M.D., a former Mayo Clinic researcher currently at Johns Hopkins University.

A similar, but unrelated study by A.R. Khan, M.D., involving researchers at Mayo Clinic and other institutions, found that use of certain lipid-lowering medicines, commonly referred to as statins, may have a role in reducing the risk of developing community-acquired pneumonia and associated mortality. That study, published last month in PLOS ONE, reviewed 18 clinical trials. The evidence was considered less reliable due to design issues, bias and other factors in the original studies.

Vaccination remains the most powerful tool in infection prevention, researchers say. The Centers for Disease Control and Prevention recommends that all adults 65 or older should receive the pneumonia vaccine and that anyone 19 or older with risk factors such as immune deficiency or chronic lung disease also should get it.

###

About Mayo Clinic

Mayo Clinic is a nonprofit worldwide leader in medical care, research and education for people from all walks of life. For more information, visit www.mayoclinic.com and www.mayoclinic.org/news.

Journalists can become a member of the Mayo Clinic News Network for the latest health, science and research news and access to video, audio, text and graphic elements that can be downloaded or embedded.

---

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?

AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.

Source: http://www.eurekalert.org/pub_releases/2013-02/mc-mcf022813.php

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New dinosaur species: First fossil evidence shows small crocs fed on baby dinosaurs

Feb. 28, 2013 ? A South Dakota School of Mines & Technology assistant professor and his team have discovered a new species of herbivorous dinosaur and today published the first fossil evidence of prehistoric crocodyliforms feeding on small dinosaurs.

Research by Clint Boyd, Ph.D., provides the first definitive evidence that plant-eating baby ornithopod dinosaurs were a food of choice for the crocodyliform, a now extinct relative of the crocodile family. While conducting their research, the team also discovered that this dinosaur prey was a previously unrecognized species of a small ornithopod dinosaur, which has yet to be named.

The evidence found in what is now known as the Grand Staircase Escalante-National Monument in southern Utah dates back to the late Cretaceous period, toward the end of the age of dinosaurs, and was published today in the online journal PLOS ONE. The complete research findings of Boyd and Stephanie K. Drumheller, of the University of Iowa and the University of Tennessee, and Terry A. Gates, of North Carolina State University and the Natural History Museum of Utah, can be accessed online (see journal reference below).

A large number of mostly tiny bits of dinosaur bones were recovered in groups at four locations within the Utah park -- which paleontologists and geologists know as the Upper Cretaceous (Campanian) Kaiparowits Formation -- leading paleontologists to believe that crocodyliforms had fed on baby dinosaurs 1-2 meters in total length.

Evidence shows bite marks on bone joints, as well as breakthrough proof of a crocodyliform tooth still embedded in a dinosaur femur.

The findings are significant because historically dinosaurs have been depicted as the dominant species. "The traditional ideas you see in popular literature are that when little baby dinosaurs are either coming out of a nesting grounds or out somewhere on their own, they are normally having to worry about the theropod dinosaurs, the things like raptors or, on bigger scales, the T. rex. So this kind of adds a new dimension," Boyd said. "You had your dominant riverine carnivores, the crocodyliforms, attacking these herbivores as well, so they kind of had it coming from all sides."

Based on teeth marks left on bones and the large amounts of fragments left behind, it is believed the crocodyliforms were also diminutive in size, perhaps no more than 2 meters long. A larger species of crocodyliform would have been more likely to gulp down its prey without leaving behind traces of "busted up" bone fragments.

Until now, paleontologists had direct evidence only of "very large crocodyliforms" interacting with "very large dinosaurs."

"It's not often that you get events from the fossil record that are action-related," Boyd explained. "While you generally assume there was probably a lot more interaction going on, we didn't have any of that preserved in the fossil record yet. This is the first time that we have definitive evidence that you had this kind of partitioning, of your smaller crocodyliforms attacking the smaller herbivorous dinosaurs," he said, adding that this is only the second published instance of a crocodyliform tooth embedded in any prey animal in the fossil record.

"A lot of times you find material in close association or you can find some feeding marks or traces on the outside of the bone and you can hypothesize that maybe it was a certain animal doing this, but this was only the second time we have really good definitive evidence of a crocodyliform feeding on a prey animal and in this case an ornithischian dinosaur," Boyd said.

The high concentrations of tiny dinosaur bones led researchers to conclude a type of selection occurred, that crocodyliforms were preferentially feeding on these miniature dinosaurs. "Maybe it was closer to a nesting ground where baby dinosaurs would have been more abundant, and so the smaller crocodyliforms were hanging out there getting a lunch," Boyd added.

"When we started looking at all the other bones, we starting finding marks that are known to be diagnostic for crocodyliform feeding traces, so all that evidence coming together suddenly started to make sense as to why we were not finding good complete specimens of these little ornithischian dinosaurs," Boyd explained. "Most of the bites marks are concentrated around the joints, which is where the crocodyliform would tend to bite, and then, when they do their pulling or the death roll that they tend to do, the ends of the bones tend to snap off more often than not in those actions. That's why we were finding these fragmentary bones."

In the process of their research, the team discovered through diagnostic cranial material that these baby prey are a new, as yet-to-be-named dinosaur species. Details on this new species will soon be published in another paper.

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The above story is reprinted from materials provided by South Dakota School of Mines and Technology.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Clint A. Boyd, Stephanie K. Drumheller, Terry A. Gates. Crocodyliform Feeding Traces on Juvenile Ornithischian Dinosaurs from the Upper Cretaceous (Campanian) Kaiparowits Formation, Utah. PLoS ONE, 2013; 8 (2): e57605 DOI: 10.1371/journal.pone.0057605

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/~3/F3jLe2V-sTc/130228171504.htm

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Silver nanoparticles may adversely affect environment

Thursday, February 28, 2013

In experiments mimicking a natural environment, Duke University researchers have demonstrated that the silver nanoparticles used in many consumer products can have an adverse effect on plants and microorganisms.

Fifty days after scientists applied a single low dose of silver nanoparticles, the experimental environments produced about a third less biomass in some plants and microbes.

These preliminary findings are important, the researchers said, because little is known about the environmental effects of silver nanoparticles, which are found in textiles, clothing, children's toys and pacifiers, disinfectants and toothpaste.

"No one really knows what the effects of these particles are in the environment," said Benjamin Colman, a post-doctoral fellow in Duke's biology department and a member of the Center for the Environmental Implications of Nanotechnology (CEINT).

"We're trying to come up with the data that can be used to help regulators determine the risks to the environment from silver nanoparticle exposures," Colman said. CEINT's research is funded by the National Science Foundation and the Environmental Protection Agency

Previous studies have involved high concentrations of the nanoparticles in a laboratory setting, which the researchers point out, doesn't represent "real-world" conditions.

"Results from laboratory studies are difficult to extrapolate to ecosystems, where exposures likely will be at low concentrations and there is a diversity of organisms," Colman said.

Silver nanoparticles are used in consumer products because they can kill bacteria, inhibiting unwanted odors. They work through a variety of mechanisms, including generating free radicals of oxygen which can cause DNA damage to microbial membranes without harming human cells.

The main route by which these particles enter the environment is as a by-product of sewage treatment plants. The nanoparticles are too small to be filtered out, so they and other materials end up in the resulting wastewater treatment "sludge," which is then spread on the land surface as a fertilizer.

For their studies, the researchers created mesocosms, which are small, man-made structures containing different plants and microorganisms meant to represent the environment. They applied sludge with low doses of silver nanoparticles in some of the mesocosms, then compared plants and microorganisms from treated and untreated mesocosms after 50 days.

The study appeared online Feb. 27 in the journal PLOS One.

The researchers found that one of the plants studied, a common annual grass known as Microstegium vimeneum, had 32 percent less biomass in the mesocosms treated with the nanoparticles. Microbes were also affected by the nanoparticles, Colman said. One enzyme associated with helping microbes deal with external stresses was 52 percent less active, while another enzyme that helps regulate processes within the cell was 27 percent less active. The overall biomass of the microbes was also 35 percent lower, he said.

"Our field studies show adverse responses of plants and microorganisms following a single low dose of silver nanoparticles applied by a sewage biosolid," Colman said. "An estimated 60 percent of the average 5.6 million tons of biosolids produced each year is applied to the land for various reasons, and this practice represents an important and understudied route of exposure of natural ecosystems to engineered nanoparticles."

"Our results show that silver nanoparticles in the biosolids, added at concentrations that would be expected, caused ecosystem-level impacts," Colman said. "Specifically, the nanoparticles led to an increase in nitrous oxide fluxes, changes in microbial community composition, biomass, and extracellular enzyme activity, as well as species-specific effects on the above-ground vegetation."

The researchers plan to continue to study longer-term effects of silver nanoparticles and to examine another ubiquitous nanoparticle ? titanium dioxide.

###

Duke University: http://www.duke.edu

Thanks to Duke University for this article.

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Source: http://www.labspaces.net/127060/Silver_nanoparticles_may_adversely_affect_environment

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This Is a Totally Free Coffeemaker For Trying Out Bougie Coffee

The Hario V60 is the coffeemaker you've seen at all manner of hipster coffeeshops. Although it's easy to be intimidated by its coffee credentials, once you get the hang of using it, it's a great way to make daily coffee. It's simple. It takes two minutes. It reliably and consistently makes a good cup of pourover coffee. Here's how you use it. More »

Source: http://feeds.gawker.com/~r/gizmodo/full/~3/vIuKxBQ2gTg/this-is-a-totally-free-coffeemaker-for-trying-out-bougie-coffee

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Calif. mayor puts lock-picking class in newsletter

OAKLAND, Calif. (AP) ? The mayor of a California city struggling with a spike in burglaries and other crimes is apologizing for promoting a class about how to pick locks in her newsletter.

Oakland Mayor Jean Quan said Wednesday she understood the reaction of people who were upset about a listing for the lock-picking class. She said she will do a better job reviewing listings in the future.

The Oakland Tribune reports (http://bit.ly/WsyCqq) that the class ? offered through the website, workshopweekend.net ? was geared toward people who misplace their keys. But it didn't go over well with some residents given the city's crime woes, including a more-than 40 percent jump in burglaries last year.

Associated Press

Source: http://hosted2.ap.org/APDEFAULT/aa9398e6757a46fa93ed5dea7bd3729e/Article_2013-02-28-US-ODD-Mayor-Lock-Picking-Class/id-caa3597580674c3e97a4602815300a31

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Duayne Samples Builds Little Free Library In Front Yard (VIDEO)

Duayne Samples, a Folsom, California man, has built a free library in his front yard.

Samples calls it the "Little Free Library," and built it so neighbors didn't have to go far to get good books. He was motivated to do this as part of an effort to promote literacy.

Samples also says, "A lot of times neighbors don't know neighbors any more, so hopefully this will help bring our community a little closer."

This isn't the first little free library. Samples was inspired by other examples of free homemade libraries that he'd seen.

The library is small; it looks like a homemade birdhouse. It also has a sign that reads "Take a book. Leave a book. Or do both."

Watch the whole video for more information!

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Source: http://www.huffingtonpost.com/2013/02/27/little-free-library-_n_2774016.html

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