Posts tagged science
Articles and news from the latest research reports.
'Tree of life' constructed for all living bird species
Scientists have mapped the evolutionary relationships among all 9,993 of the world’s known living bird species. The study, published today in Nature, is an ambitious project that uses DNA-sequence data to create a phylogenetic tree — a branching map of evolutionary relationships among species — that also links global bird speciation rates across space and time.
“This is the first dated tree of life for a class of species this size to be put on a global map,” says study co-author Walter Jetz, an evolutionary biologist at Yale University in New Haven, Connecticut.
UC Santa Barbara Scientists Learn How to Unlock the Destiny of a Cell: A Gift for the Tin Man?
Scientists have discovered that breaking a biological signaling system in an embryo allows them to change the destiny of a cell. The findings could lead to new ways of making replacement organs.
The discovery was made in the laboratory of Joel H. Rothman, a professor in the Department of Molecular, Cellular, and Developmental Biology at UC Santa Barbara. The studies were reported in the interdisciplinary journal Genes and Development, and were carried out by Ph.D student Nareg Djabrayan, in collaboration with Rothman and two other members of the laboratory, Ph.D student Erica Sommermann and postdoctoral fellow Nathaniel Dudley.
"At some point along the way toward becoming part of a complete individual, cells become destined to choose a particular identity and long-term profession," Rothman noted. "Once a cell chooses who it will be, it locks onto that identity for the remainder of its life."
A cell that is destined to become a heart cell functions exclusively in the heart until it dies, and never chooses later to change jobs by becoming, for example, a brain cell. “If Oz’s wizard possessed the powers he claimed, and had a spare brain lying around, he could switch it to a heart as a gift for the Tin Man. And he could reverse the trick for the Scarecrow,” Rothman said.
Similarly, the researchers have found a way to unlock cells’ destinies and lead them to take on a new profession.
An elephant that speaks Korean
An Asian elephant named Koshik can imitate human speech, speaking words in Korean that can be readily understood by those who know the language. The elephant accomplishes this in a most unusual way: he vocalizes with his trunk in his mouth.
The elephant’s vocabulary consists of exactly five words, researchers report on November 1 in Current Biology, a Cell Press publication. Those include “annyong” (“hello”), “anja” (“sit down”), “aniya” (“no”), “nuo” (“lie down”), and “choah” (“good”). Ultimately, Koshik’s language skills may provide important insights into the biology and evolution of complex vocal learning, an ability that is critical for human speech and music, the researchers say.
"Human speech basically has two important aspects, pitch and timbre," says Angela Stoeger of the University of Vienna. "Intriguingly, the elephant Koshik is capable of matching both pitch and timbre patterns: he accurately imitates human formants as well as the voice pitch of his trainers. This is remarkable considering the huge size, the long vocal tract, and other anatomical differences between an elephant and a human."
Virtual reality ‘beaming’ technology transforms human-animal interaction
Using cutting-edge virtual reality technology, researchers have ‘beamed’ a person into a rat facility allowing the rat and human to interact with each other on the same scale.
Published in PLOS ONE, the research enables the rat to interact with a rat-sized robot controlled by a human participant in a different location. At the same time, the human participant (who is in a virtual environment) interacts with a human-sized avatar that is controlled by the movements of the distant rat. The authors hope the new technology will be used to study animal behaviour in a completely new way.
Computer scientists at UCL and the University of Barcelona have been working on the idea of ‘beaming’ for some time now, having last year digitally beamed a scientist in Barcelona to London to be interviewed by a journalist.
The researchers define ‘beaming’ as digitally transporting a representation of yourself to a distant place, where you can interact with the people there as if you were there. This is achieved through a combination of virtual reality and teleoperator systems. The visitor to the remote place (the destination) is represented there ideally by a physical robot.
Caffeine’s effect on the brain’s adenosine receptors visualized for the first time
Scans allow researchers to study the link between caffeine and neurodegenerative disorders.
Molecular imaging with positron emission tomography (PET) has enabled scientists for the first time to visualize binding sites of caffeine in the living human brain to explore possible positive and negative effects of caffeine consumption. According to research published in the November issue of The Journal of Nuclear Medicine, PET imaging with F-18-8-cyclopentyl-3-(3-fluoropropyl)-1-propylxanthine (F-18-CPFPX) shows that repeated intake of caffeinated beverages throughout a day results in up to 50 percent occupancy of the brain’s A1 adenosine receptors.
"The effects of caffeine to the human body are generally attributed to the cerebral adenosine receptors. In the human brain the A1 adenosine receptor is the most abundant," said David Elmenhorst, MD, lead author of "Caffeine Occupancy of Human Cerebral A1 Adenosine Receptors: In Vivo Quantification with F-18-CPFPX and PET." "In vitro studies have shown that commonly consumed quantities of caffeine have led to a high A1 adenosine occupancy. Our study aimed to measure the A1 adenosine receptor occupancy with in vivo imaging."
This is your brain on politics
With the U.S. presidential election just days away, new research from the University of South Carolina provides fresh evidence that choosing a candidate may depend more on our biological make-up than a careful analysis of issues.
That’s because the brains of self-identified Democrats and Republicans are hard-wired differently and may be naturally inclined to hold varying, if not opposing, perceptions and values. The USC study, which analyzed MRI scans of 24 USC students, builds on existing research in the emerging field of political neuroscience.
“The differences are significant and real,” said lead researcher Roger D. Newman-Norlund, an assistant professor of exercise science in the Arnold School of Public Health and the director of USC’s new Brain Simulation Laboratory.
The study focused on the mirror neuron system, a network of brain areas linked to a host of social and emotional abilities. After declaring their political affiliation, The subjects were given questionnaires designed to gauge their attitudes on a range of select political issues. Next, they were given “resting state” MRIs which made it possible to analyze the strength of connections within the mirror neuron system in both the left and right hemispheres of their brains; specifically the inferior frontal gyrus, supramarginal gyrus and angular gyrus.
The results found more neural activity in areas believed to be linked with broad social connectedness in Democrats (friends, the world at-large) and more activity in areas linked with tight social connectedness in the Republicans (family, country). In some ways the study confirms a stereotype about members of the two parties — Democrats tend to be more global and Republicans more America-centric — but it actually runs counter to other recent research indicating Democrats enjoyed a virtual lock on caring for others.
Biology and ideology: The anatomy of politics
An increasing number of studies suggest that biology can exert a significant influence on political beliefs and behaviours. Biological factors including genes, hormone levels and neurotransmitter systems may partly shape people’s attitudes on political issues such as welfare, immigration, same-sex marriage and war. And shrewd politicians might be able to take advantage of those biological levers through clever advertisements aimed at voters’ primal emotions.
Many of the studies linking biology to politics remain controversial and unreplicated. But the overall body of evidence is growing and might alter how people think about their own and others’ political attitudes.
“People are proud of their political beliefs,” says John Hibbing, a political scientist at the University of Nebraska–Lincoln. “We tend to think they’re the result of some rational responses to the world around us.” But in fact, a combination of genes and early experiences may predispose people to perceive and respond to political issues in certain ways. Recognizing that could help the public and politicians to develop more respect for those with opposing viewpoints.
Brain May ‘See’ More Than the Eyes, Study Indicates
Vision may be less important to “seeing” than is the brain’s ability to process points of light into complex images, according to a new study of the fruit fly visual system currently published in the online journal Nature Communications.
University of Virginia researchers have found that the very simple eyes of fruit fly larvae, with only 24 total photoreceptors (the human eye contains more than 125 million), provide just enough light or visual input to allow the animal’s relatively large brain to assemble that input into images.
“It blows open how we think about vision,” said Barry Condron, a neurobiologist in U.Va.’s College of Arts & Sciences, who oversaw the study. “This tells us that visual input may not be as important to sight as the brain working behind it. In this case, the brain apparently is able to compensate for the minimal visual input.”
Condron’s graduate students, Elizabeth Daubert, Nick Macedonia and Catherine Hamilton, conducted a series of experiments to test the vision of fruit fly larvae after they noticed an interesting behavior of the animals during a different study of the nervous system. They found that when a larva was tethered to the bottom of a petri dish, other larvae were attracted to it as it wiggled attempting to free itself.
The animals apparently saw the writhing motion and were attracted to it, willingly traveling toward it. After several further experiments to understand how they sensed the motion, the researchers learned that the nearly blind animals likely were seeing the action, by wagging their heads side-to-side in a scanning motion to detect it, rather than by only hearing it or feeling vibration or by smelling the trapped larva. This was a surprise because of the very simple and limited vision of fruit fly larvae.
A US man who lost his right leg in a motorcycle accident is to attempt history by using a thought-controlled bionic leg to reach the top of one of the world’s tallest skyscrapers simply by thinking: “Climb stairs”.
Advanced exoskeleton promises more independence for people with paraplegia
The dream of regaining the ability to stand up and walk has come closer to reality for people paralyzed below the waist who thought they would never take another step.
A team of engineers at Vanderbilt University’s Center for Intelligent Mechatronics has developed a powered exoskeleton that enables people with severe spinal cord injuries to stand, walk, sit and climb stairs. Its light weight, compact size and modular design promise to provide users with an unprecedented degree of independence.
The university has several patents pending on the design and Parker Hannifin Corporation – a global leader in motion and control technologies – has signed an exclusive licensing agreement to develop a commercial version of the device, which it plans on introducing in 2014.