The skull of a newly discovered 325-million-year-old shark-like species suggests that early cartilaginous and bony fishes have more to tell us about the early evolution of jawed vertebrates—including humans—than do modern sharks, as was previously thought. The new study, led by scientists at the American Museum of Natural History, shows that living sharks are actually quite advanced in evolutionary terms, despite having retained their basic "sharkiness" over millions of years. The research is published today in the journal Nature. "Sharks are traditionally thought to ...

ANN ARBOR, Mich. – As scientists catalog the trillions of bacteria found in every nook and cranny of the human body, a new look by the University of Michigan shows wide variation in the types of bacteria found in healthy people. Based on their findings in today's Nature, there is no single healthy microbiome. Rather each person harbors a unique and varied collection of bacteria that's the result of life history as well their interactions with the environment, diet and medication use. "Understanding the diversity of community types and the mechanisms that result ...

Researchers at the Wellcome Trust Sanger Institute have discovered interacting proteins on the surface of the sperm and the egg essential to begin mammalian life. These proteins, which allow the sperm and egg to recognize one another, offer new paths towards improved fertility treatments and the development of new contraceptives. Fertilisation occurs when an egg and a sperm recognise each other and fuse together to form an embryo. The Izumo protein displayed on the sperm that recognises the egg was identified in 2005 by Japanese researchers who named it Izumo, after a ...

A research team at the Biozentrum of the University of Basel has discovered an protein family that plays a central role in the fight against the bacterial pathogen Salmonella within the cells. The so called interferon-induced GTPases reveal and eliminate the bacterium's camouflage in the cell, enabling the cell to recognize the pathogen and to render it innocuous. The findings are published in the current issue of the science magazine Nature. Bacteria have developed countless strategies to hide themselves in order to evade attack by the immune system. In the body, Salmonella ...

Waves in your brain make smells stick to your memories and inner maps. When I was a child I used to sit in my grandfather's workshop, playing with wood shavings. Freshly shaven wood has a distinct smell of childhood happiness, and whenever I get a whiff of that scent my brain immediately conjures up images of my grandfather at his working bench, the heat from the fireplace and the dog next to it. Researchers at the Kavli Institute for Systems Neuroscience have recently discovered the process behind this phenomenon. The brain, it turns out, connects smells to memories ...

HOUSTON – (April 16, 2014) – As companies file their annual proxy statements with the U.S. Securities and Exchange Commission (SEC) this spring, a new study by Rice University and Cornell University shows just how S&P 500 companies have tied CEO compensation to performance. The study found large variations in the choice of performance measures, and the researchers said that companies tend to choose measures that are informative of CEO actions. "On average, firms rely mostly on accounting-based performance measures, among which they put heavier weights on income measures, ...

Scientists at Yale have confirmed a 50-year-old, previously untested theoretical prediction in physics and improved the energy storage time of a quantum switch by several orders of magnitude. They report their results in the April 17 issue of the journal Nature. High-quality quantum switches are essential for the development of quantum computers and the quantum internet — innovations that would offer vastly greater information processing power and speed than classical (digital) computers, as well as more secure information transmission. "Fighting dissipation is one ...

DURHAM, N.C. -- Maintaining an interest in the goals you pursue can improve your work and reduce burnout, according to research from Duke University. "Our research shows that interest is important in the process of pursuing goals. It allows us to perform at high levels without wearing out," said Paul O'Keefe, who conducted the studies as a doctoral student in Duke University's Department of Psychology & Neuroscience, along with associate professor Lisa Linnenbrink-Garcia. "This suggests that interest matters more than we suspected." The studies, which appear online ...

Changes in air temperature, not precipitation, drove the expansion and contraction of glaciers in Africa's Rwenzori Mountains at the height of the last ice age, according to a Dartmouth-led study funded by the National Geographic Society and the National Science Foundation. The results – along with a recent Dartmouth-led study that found air temperature also likely influenced the fluctuating size of South America's Quelccaya Ice Cap over the past millennium -- support many scientists' suspicions that today's tropical glaciers are rapidly shrinking primarily because of ...

SAN ANTONIO, Texas (April 16, 2014) — A team that includes scientists from the School of Medicine at The University of Texas Health Science Center at San Antonio, Johns Hopkins University and St. Mary's University reported the structure of a protein that helps a common fungus to infect the body. The fungal pathogen Candida albicans causes yeast infections, diaper rashes and oral thrush, and is the most common fungal pathogen to infect humans. It can also cause a life-threatening infection of the blood called disseminated candidiasis. "In this study, we determined the ...

The "brush border" – a densely packed array of finger-like projections called microvilli – covers the surfaces of the cells that line our intestines. Vanderbilt University researchers have now discovered how intestinal cells build this specialized structure, which is critical for absorbing nutrients and defending against pathogens. The findings, published April 10 in the journal Cell, reveal a role for adhesion molecules in brush border assembly and increase our understanding of intestinal pathologies associated with inherited and infectious diseases. Pathogens that destroy ...

DOWNERS GROVE, Ill. – April 16, 2014 – According to a new study, endoscopists' recommendations for timing of surveillance colonoscopy in average-risk patients with one to two small polyps are consistent with guideline recommendations in about 90 percent of cases. This may be an appropriate target for quality indicators. This is the first multicenter endoscopic database study to quantify adherence to guidelines for timing of repeat colonoscopy after one to two small polyps are found during screening colonoscopy in average-risk patients. The study appears in the April issue ...

A new study pins down a major factor behind the appearance of superconductivity—the ability to conduct electricity with 100 percent efficiency—in a promising copper-oxide material. Scientists used carefully timed pairs of laser pulses at SLAC National Accelerator Laboratory's Linac Coherent Light Source (LCLS) to trigger superconductivity in the material and immediately take x-ray snapshots of its atomic and electronic structure as superconductivity emerged. They discovered that so-called "charge stripes" of increased electrical charge melted away as superconductivity ...

Everything we do — all of our movements, thoughts and feelings – are the result of neurons talking with one another, and recent studies have suggested that some of the conversations might not be all that private. Brain cells known as astrocytes may be listening in on, or even participating in, some of those discussions. But a new mouse study suggests that astrocytes might only be tuning in part of the time — specifically, when the neurons get really excited about something. This research, published in Neuron, was supported by the National Institute of Neurological Disorders ...

Our ability to store memories improves during childhood, associated with structural changes in the hippocampus and its connections with prefrontal and parietal cortices. New research from UC Davis is exploring how these brain regions develop at this crucial time. Eventually, that could give insights into disorders that typically emerge in the transition into and during adolescence and affect memory, such as schizophrenia and depression. Located deep in the middle of the brain, the hippocampus plays a key role in forming memories. It looks something like two curving fingers ...

To reproduce or to conquer the world? Surprisingly, bacteria also face this problem. Theoretical biophysicists at Ludwig-Maximilians-Universitaet (LMU) in Munich have now shown how these organisms should decide how best to preserve their species. The bacterium Bacillus subtilis is quite adaptable. It moves about in liquids and on agar surfaces by means of flagella. Alternatively, it can stick to an underlying substrate. Actually, the bacteria proliferate most effectively in this stationary state, while motile bacteria reproduce at a notably lower rate. In order to sustain ...

RICHLAND, Wash. – Geologic and soil processes are to blame for significant baseline levels of arsenic in soil throughout Ohio, according to a study published recently in the Journal of Environmental Quality. The analysis of 842 soil samples from all corners of Ohio showed that every single sample had concentrations higher than the screening level of concern recommended by the U.S. Environmental Protection Agency. The findings should not alarm the public, say the authors, who note that regulatory levels typically are set far below those thought to be harmful. Rather, the ...

While it is well known that fertility treatments are the leading cause of increases in multiple gestations and that multiples are at elevated risk of premature birth, these results are not inevitable, concludes an article in Fertility and Sterility. The article identifies six changes in policy and practice that can reduce the odds of multiple births and prematurity, including expanding insurance coverage for in vitro fertilization (IVF) and improving doctor-patient communications about the risks associated with twins. Financial pressures provide a powerful incentive for ...

Prof. Dr. Dr. Klaus Aktories and Dr. Panagiotis Papatheodorou from the Institute of Experimental and Clinical Pharmacology and Toxicology of the University of Freiburg have discovered the receptor responsible for smuggling the toxin of the bacterium Clostridium perfringens into the cell. The TpeL toxin, which is formed by C. perfringens, a pathogen that causes gas gangrene and food poisoning. It is very similar to the toxins of many other hospital germs of the genus Clostridium. The toxins bind to surface molecules and creep into the body cell, where they lead to cell death. ...

LA JOLLA—Scientists at the Salk Institute have created a new model of memory that explains how neurons retain select memories a few hours after an event. This new framework provides a more complete picture of how memory works, which can inform research into disorders liked Parkinson's, Alzheimer's, post-traumatic stress and learning disabilities. "Previous models of memory were based on fast activity patterns," says Terry Sejnowski, holder of Salk's Francis Crick Chair and a Howard Hughes Medical Institute Investigator. "Our new model of memory makes it possible to ...

The proportion of land used to cultivate shade grown coffee, relative to the total land area of coffee cultivation, has fallen by nearly 20 percent globally since 1996, according to a new study by scientists from The University of Texas at Austin and five other institutions. The study's authors say the global shift toward a more intensive style of coffee farming is probably having a negative effect on the environment, communities and individual farmers. "The paradox is that there is greater public interest than ever in environmentally friendly coffee, but where coffee ...

This news release is available in German. Synapses are the points of contact at which information is transmitted between neurons. Without them, we would not be able to form thoughts or remember things. For memories to endure, synapses sometimes have to remain stable for very long periods. But how can a synapse last if its components have to be replaced regularly? Scientists from the Max Planck Institute of Neurobiology in Martinsried near Munich have taken a decisive step towards answering this question. They have succeeded in demonstrating that when a synapse is formed, ...

Boulder, Colo., USA – Haley M. Sapers and colleagues provide what may be the first report of biological activity preserved in impact glass. Recent research has suggested that impact events create novel within-rock microbial habitats. In their paper, "Enigmatic tubular features in impact glass," Sapers and colleagues analyze tubular features in hydrothermally altered impact glass from the Ries Impact Structure, Germany, that are remarkably similar to the bioalteration textures observed in volcanic glasses. The authors note that mineral-forming processes cannot easily ...

Irvine, Calif., April 16, 2014 — A class of drugs developed to treat immune-related conditions and cancer – including one currently in clinical trials for glioblastoma and other tumors – eliminates neural inflammation associated with dementia-linked diseases and brain injuries, according to UC Irvine researchers. In their study, assistant professor of neurobiology & behavior Kim Green and colleagues discovered that the drugs, which can be delivered orally, eradicated microglia, the primary immune cells of the brain. These cells exacerbate many neural diseases, including ...

A research group composed of Dr. Martin Prechtl, Leo Heim and their colleagues at the University of Cologne's Department of Chemistry has discovered a new method of generating hydrogen using water and formaldehyde. The generation of hydrogen from liquids is of particular interest when it comes to fuel cell technologies. The results of the project, entitled "Selective and mild hydrogen production using water and formaldehyde", have recently been published in the journal Nature Communications. Among other applications, the new approach can be used to recycle industrial ...