Caribbean frogs started with a single, ancient voyage on a raft from South America
...ral American frogs, the research also revealed and defined an unusually large and unpredicted group of species in South America. "The South American group may have more than 400 species and is mostly associated with the large Andes mountains of South America," Hedges said. "Until now, the entire group of...New findings challenge established views on human genome
...ce data to identify genes, which are traditionally defined as the parts of the genome that code for proteins. The protein-coding component of these genes makes up just a small fraction of the human genome – 1.5 percent to 2 percent. Evidence exists that other parts of the genome also have important function...Study identifies 5 genetic themes key to keeping stem cells in a primitive, flexible state
For more than 25 years, stem cells have been defined based on what they can become: more of themselves, as well as multiple different specialized cell types. But as genetic techniques have become increasingly powerful, many scientists have sought a more molecular definition of stem cells, based on the ...US control strategies may make flu epidemics worse, UCLA study shows
...evel and influenza prevalence, where prevalence is defined as the proportion of the population that is infected. The individual-level model was based on the human biological attributes of memory and adaptability. "We assume that the decision of each individual is based upon self-interest, that people wis...Legal ruling may put endangered species in danger
...rs protesting the ruling say that the original law defined an endangered species as one "at risk of extinction throughout all or a significant portion of its range." "It is clear that Congress intended 'range' to be the historic or former range of the animal," said John A.Vucetich, an assistant professor ......n time. The entirety of all possible networks of a defined dynamics resembles a complex figure in a multidimensional space. Here, every point on the surface specifies the data required to determine a network with the desired dynamics. Memmesheimer and Timme have now worked out a mathematical description for ...Pitt study notes decline in male births in the US and Japan
... out that examine sex ratio in smaller groups with defined exposures as a potential indicator of environmental contamination.? ...'Marathon mice' elucidate little-known muscle type
... activity of shorter duration. The fiber types are defined by which "myosin heavy chains" (MHCs) they contain and by their metabolic capacity, a feature largely determined by the number of energy-producing mitochondria they house. Myosins are motor proteins that consist of both "heavy" and "light" amino acid...Cocoa 'vitamin' health benefits could outshine penicillin
...does not currently meet the criteria. Vitamins are defined as essential to the normal functioning, metabolism, regulation and growth of cells and deficiency is usually linked to disease. At the moment, the science does not support epicatechin having an essential role. But, Fabricant, who is vice president sc...A new study of living cells could revolutionize the way we test drugs
.... "Probably, the most important outcome is that we defined an important goal. Cellular cardiograms can no longer be seen as absurd or science-fictional. If not us then someone else will soon develop a technique sensitive enough for such studies." ...ATR checkpoint-activating DNA structure
...e novel and valuable. The elucidation of the first defined DNA structure capable of eliciting the ATR checkpoint will aid researchers to further identify additional checkpoint proteins, as well as understand how checkpoint signals are generated and regulated inside the cell....'Night owls' report more insomnia-related symptoms
....? Insomnia, a classification of sleep disorders defined by difficulty falling asleep or staying asleep, waking up too early, or poor quality sleep, is the most common sleep complaint at any age. About 30 percent of adults have symptoms of insomnia. The amount of sleep a person gets affects his or her ...Stability of mRNA/DNA and DNA/DNA duplexes modulates mRNA transcription
...ns. However, nucleic acids are real molecules with defined physical characteristics, which can influence their biological functions." In this work the authors present a calculation of the thermodynamic stability of DNA/DNA and mRNA/DNA duplexes across the genomes of four species in the genus Saccharomyces...Is there a pilot in the insect?
...e visual field, creating an "optic flow", which is defined as the angular speed at which the ground contrasts move past. By definition, this angular speed is equal to the ratio of the horizontal speed and the altitude. What these authors call an "optic flow regulator" is a reflex that keeps the optic flow,...What recognizes what in plant disease resistance?
... show how one aspect of the plant immune system is defined by the gene-for-gene hypothesis: a plant Resistance (R) gene encodes a protein that specifically recognizes and protects against one pathogen or strain of a pathogen carrying a corresponding Avirulence (Avr) gene. In tobacco and its relatives, the...Genes and biomarkers that allow doctors to choose the right therapy for the right patient
...and CI-1040, a MEK enzyme inhibitor. These studies defined molecular signatures that predicted individual responses among the cell lines to the drugs. For Lapatinib, the strongest correlate of response was amplification and over expression of ErBB2, consistent with clinical experience. For CI-1040, changes...Scientists to track impact of Asian dust and pollution on clouds, weather, climate change
...ed by fiber optics delivering light to genetically defined populations of nerve cells....Common algae helps illustrate mammalian brain electrical circuitry
...ed by fiber optics delivering light to genetically defined populations of nerve cells....Antivirals effectively curb influenza virus
...ound a significant reduction in infectiousness, as defined by reductions in influenza illnesses in household contacts, when oseltamivir was used for treatment of ill persons, but not when zanamivir was administered. Although these results are of interest, the authors stress that the numbers were small and co......e to the different CNS structures. The regions are defined by the unique combination of regulatory genes expressed, which endow every type of neuron with a specific molecular fingerprint. Comparing the molecular fingerpint of Platynereis nerve cells with what is known about vertebrates revealed surprising si...