Three-dimensional Molar Enamel Distribution And Thickness In Australopithecus And Paranthropus
Thick molar enamel is among the few diagnostic characters of hominins that are measurable in fossil specimens. Despite a long history of study and characterisation of Paranthropus molars as relatively "hyper-thick, " only a few tooth fragments and controlled planes of section (designed to be proxies of whole-crown thickness) have been measured.
Biological Switches And Clocks
To introduce this Special Issue on Biological Switches and Clocks, we review the historical development of mathematical models of bistability and oscillations in chemical reaction networks. In the 1960s and 70s, these models were limited to well-studied biochemical examples, such as glycolytic oscillations and cyclic AMP signaling.
News From The American Chemical Society, May 28, 2008
Lead leaching and faucet corrosion in PVC home plumbingScientists in Virginia are reporting that home plumbing systems constructed with polyvinyl chloride (PVC) plastic pipes may be more susceptible to leaching of lead and copper into drinking water than other types of piping - especially when PVC systems include brass fixtures and pipefittings.
Single-molecule Magnetic Tweezer Tests On DNA
Biomedical researchers stretch and twist single DNA molecules with magnetic tweezers. By making the molecule writhe into a plectoneme (ply), DNA parameters, such as its effective radius, are estimated. Adding untangling enzymes (topoisomerases) to the DNA's environment, their individual cuts are detected as jumps in extension.
Mitochondrial Sequence Divergence Among Antarctic Killer Whale Ecotypes Is Consistent With Multiple Species
Recently, three visually distinct forms of killer whales (Orcinus orca) were described from Antarctic waters and designated as types A, B and C. Based on consistent differences in prey selection and habitat preferences, morphological divergence and apparent lack of interbreeding among these broadly sympatric forms, it was suggested that they may represent separate species.
Population Divergence In Plant Species Reflects Latitudinal Biodiversity Gradients
The trend for increasing biodiversity from the poles to the tropics is one of the best-known patterns in nature. This latitudinal gradient has primarily been documented using extant species as the measure of biodiversity. Eo et al. (2008) evaluated this pattern by considering the magnitude of genetic divergence among populations within 45 species of plants.
An Analysis Of The Fixation Probability Of A Mutant On Special Classes Of Non-directed Graphs
Traditionally the modelling of evolution has assumed homogeneous populations, partly because modelling real populations with complex underlying structures mathematically is difficult. Recent investigations of structured models, represented by graphs, have shown that some structures are far more conducive to the process of evolution, indicated by the ability of initially rare mutants to invade, than others.
Potential Treatments From Cryptic Genes
Big pharma gave up on soil bacteria as a source of antibiotics too soon, according to research published in the June issue of Microbiology. Scientists have been mining microbial genomes for new natural products that may have applications in the treatment of MRSA and cancer and have made some exciting discoveries.
Scientists Move Forward To Set Up A European Network Of Biobanks
It is a fact that the European population is getting older and therefore has an increasing need, both social and economical, to live a healthier life and to find cures for devastating diseases such as cancer, Alzheimer or HIV. To accomplish that goal, sharing the access to samples of blood, tissue, DNA, proteins and other human and genetic materials will be essential.
The Largest Among The Smallest: The Body Mass Of The Giant Rodent Josephoartigasia Monesi
Body size is correlated with most physiological, ecological and evolutionary traits and is the most important character of an organism. Today, the largest living rodent is the 40 kg-capybara but rodents have been much bigger in the past. The recently described fossil rodent Josephoartigasia.