Posts Tagged ‘biology’

Chimpanzees prefer firm, stable beds

Main Point:

Chimps select tree branches for stable, comfortable, and safe beds.

Published in:

PLOS ONE

Study Further:

Chimpanzees may select a certain type of wood, Ugandan Ironwood, over other options for its firm, stable, and resilient properties to make their bed, according to a study published April 16, 2014 in the open-access journal PLOS ONE by David Samson from the University of Nevada and Kevin Hunt from Indiana University.

Chimpanzees use tree branches to build beds or nests in trees. They select certain tree species to sleep in more frequently than other, but the reason for selecting a particular tree is unclear. To determine whether the physical properties of trees influenced nesting site selection, scientists measured the physical characteristics of wood from common tree species at the Toro-Semliki Wildlife Reserve, Uganda. They measured the stiffness and bending strength of 326 branches from the seven tree species most commonly used by the chimps. Additionally, they measured leaf surface area and determined the structure or architecture of each of the seven species.

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Be the first to comment - What do you think?  Posted by saypeople - April 17, 2014 at 2:00 am

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New species discovery sheds light on herbivore evolution

Main Point:

Fossil extends knowledge on caseid eating habits and time period.

Published in:

PLOS ONE

Study Further:

A new fossil may provide evidence that large caseid herbivores, the largest known terrestrial vertebrates of their time, evolved from small non-herbivorous members of that group, according to a study published April 16, 2014 in the open-access journal PLOS ONE by Robert Reisz from University of Toronto and Jörg Fröbisch of the Museum für Naturkunde.

The origin and early evolution of vertebrates living on land led to major changes in the structure of terrestrial ecosystems. The first appearance of herbivores played a pivotal role in this transformation, and a newly discovered species, Eocasea martini, from Kansas, USA may provide information about early caseids. In this study, researchers describe and discuss the evolutionary and paleoecological implications of this new taxon.

The oldest caseid recorded, E. martini was from the Late Carboniferous, about 305-300 million years ago. The characteristics of the fossil indicate that it was likely a small carnivore. Caseids are characteristically herbivores, so this fossil may provide evidence that large caseid herbivores evolved from small carnivorous members of that group. This pattern is mirrored by three other groups, documenting multiple, independent, but temporally staggered, origins of herbivory and a possible increase in body size among early terrestrial tetrapods, leading to patterns consistent with modern terrestrial ecosystems.

“The evolution of herbivory was revolutionary to life on land because it meant terrestrial vertebrates could directly access the vast resources provided by terrestrial plants,” says paleontologist Robert Reisz, Department of Biology. “These herbivores in turn became a major food resource for large land predators.”

Reference:

Reisz RR, Fröbisch J (2014) The Oldest Caseid Synapsid from the Late Pennsylvanian of Kansas, and the Evolution of Herbivory in Terrestrial Vertebrates. PLoS ONE 9(4): e94518. doi:10.1371/journal.pone.0094518, http://dx.plos.org/10.1371/journal.pone.0094518

Financial Disclosure:

Funding provided by a Discovery Grant from Natural Sciences and Engineering Research Council (Canada) and an Alexander von Humboldt Visiting Fellowship (Germany) to RRR Sofja Kovalevskaja Award of the Alexander von Humboldt Foundation donated by the Federal Ministry of Education and Research (Germany) to JF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interest Statement:

The authors have declared that no competing interests exist.

Contact:

Robert Reisz, robert.reisz@utoronto.ca, ph: 905-828-3981; Nicolle Wahl (press officer), nicolle.wahl@utoronto.ca, 905-569-4656

Be the first to comment - What do you think?  Posted by saypeople - at 2:00 am

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Functional brain imaging reliably predicts which vegetative patients have potential to recover consciousness

Main Points:

A functional brain imaging technique known as positron emission tomography (PET) is a promising tool for determining which severely brain damaged individuals in vegetative states have the potential to recover consciousness, according to new research published in The Lancet.

Published in:

The Lancet

Study Further:

It is the first time that researchers have tested the diagnostic accuracy of functional brain imaging techniques in clinical practice.

“Our findings suggest that PET imaging can reveal cognitive processes that aren’t visible through traditional bedside tests, and could substantially complement standardbehavioural assessments to identify unresponsive or “vegetative” patients who have the potential for long-term recovery”, says study leader Professor Steven Laureys from the University of Liége in Belgium.*

In severely brain-damaged individuals, judging the level of consciousness has proved challenging. Traditionally, bedside clinical examinations have been used to decide whether patients are in a minimally conscious state (MCS), in which there is some evidence of awareness and response to stimuli, or are in a vegetative state (VS) also known as unresponsive wakefulness syndrome, where there is neither, and the chance of recovery is much lower. But up to 40% of patients are misdiagnosed using these examinations.

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Be the first to comment - What do you think?  Posted by saypeople - April 16, 2014 at 5:01 am

Categories: Medical   Tags: , , , , ,

Viewpoint Offers Details of BRAIN Initiative

Introduction:

JAMA Neurology is publishing online a Viewpoint written by Cornelia I. Bargmann, Ph.D., of Rockefeller University, New York, and William T. Newsome, Ph.D., of Stanford University, California, who are neuroscientists and co-chairs of the working group of the advisory committee to the National Institutes of Health director responsible for planning the scientific program of the BRAIN Initiative.

Published in:

JAMA Neurology Viewpoint

Excerpts of the article are highlighted below:

“On April 2, 2013, President Obama announced the Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative, a partnership between the National Institutes of Health (NIH), the National Science Foundation, the Defense Advanced Research Projects Agency, private foundations and researchers.”

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Be the first to comment - What do you think?  Posted by saypeople - April 8, 2014 at 1:00 am

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What bank voles can teach us about prion disease transmission and neurodegeneration

Bank Vole (Credit: Peter Trimming, Flickr, CC-BY)

Bank Vole (Credit: Peter Trimming, Flickr, CC-BY)

Main Points:

When cannibals ate brains of people who died from prion disease, many of them fell ill with the fatal neurodegenerative disease as well. Likewise, when cows were fed protein contaminated with bovine prions, many of them developed mad cow disease. On the other hand, transmission of prions between species, for example from cows, sheep, or deer to humans, is—fortunately—inefficient, and only a small proportion of exposed recipients become sick within their lifetimes.

Published in:

PLOS Pathogens

Study Further:

A study published on April 3rd in PLOS Pathogens takes a close look at one exception to this rule: bank voles appear to lack a species barrier for prion transmission, and their universal susceptibility turns out to be both informative and useful for the development of strategies to prevent prion transmission.

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Be the first to comment - What do you think?  Posted by saypeople - April 4, 2014 at 2:00 am

Categories: Medical   Tags: , , ,

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