Acid-sensing ion channel 3 mediates peripheral anti-hyperalgesia effects of acupuncture in mice inflammatory pain

Background  

Peripheral tissue inflammation initiates hyperalgesia accompanied by tissue acidosis, nociceptor activation, and inflammation mediators. Recent studies have suggested a significantly increased expression of acid-sensing ion channel 3 (ASIC3) in both carrageenan- and complete Freund's adjuvant (CFA)-induced inflammation. This study tested the hypothesis that acupuncture is curative for mechanical hyperalgesia induced by peripheral inflammation.     

Protein structure similarity from principle component correlation analysis

Background  

Owing to rapid expansion of protein structure databases in recent years, methods of structure comparison are becoming increasingly effective and important in revealing novel information on functional properties of proteins and their roles in the grand scheme of evolutionary biology. Currently, the structural similarity between two proteins is measured by the root-mean-square-deviation (RMSD) in their best-superimposed atomic coordinates. RMSD is the golden rule of measuring structural similarity when the structures are nearly identical; it, however, fails to detect the higher order topological similarities in proteins evolved into different shapes. We propose new algorithms for extracting geometrical invariants of proteins that can be effectively used to identify homologous protein structures or topologies in order to quantify both close and remote structural similarities.     

Note on Rashevsky's equation for cellular growth

The equation for growth by intussusception involves the product of the internal concentrations ofn metabolites. This products is shown, in general, to satisfy a certain algebraic equation of then-th degree. Approximate solutions are exhibited for a somewhat wider class of cases than are considered by Rashevsky.     

The kinetics of enzyme inactivation

The course of hydrolysis of β-glycerophosphate catalyzed by a group of different enzyme extracts, both with and without the addition of Mg, with and without preincubation of the enzyme, has been studied and the results discussed on the basis of a mathematical analysis. In all the extracts, it appears that two distinct and independently acting constituent enzymes—or perhaps “principles” of the same enzyme—are present, one acting much more rapidly but also more rapidly inactivated than the other. Storage in the refrigerator changes markedly the behavior of both constituents, though in different ways. There is evidence that in some cases an enzyme is limited in its hydrolytic “capacity” in the sense that after an enzyme molecule has decomposed a definite number of substrate molecules, it thereafter becomes entirely passive. Further, there is evidence, in the case of one extract, that the roles of catalytically more and less active constituents in the absence of Mg are reversed in its presence. Finally, a damped periodicity is found which indicates the presence of two factors of an unknown sort which influence and are influenced by the inactivation of the enzyme.     

A note on the horopter

By assuming the fixity (but not the symmetry) of corresponding points on the two retinae, it is possible to derive the equation of any horopter when one is known. In particular when, as experiment shows, one horopter is linear, then all horopters must be conics. These have the form given by Ogle, but whereas Ogle leaves one parameter undetermined at each fixation, on our assumption the only arbitrary parameter is determined by the position of the linear horopter.     

Conditional random pattern model for copy number aberration detection

Background  

DNA copy number aberration (CNA) is very important in the pathogenesis of tumors and other diseases. For example, CNAs may result in suppression of anti-oncogenes and activation of oncogenes, which would cause certain types of cancers. High density single nucleotide polymorphism (SNP) array data is widely used for the CNA detection. However, it is nontrivial to detect the CNA automatically because the signals obtained from high density SNP arrays often have low signal-to-noise ratio (SNR), which might be caused by whole genome amplification, mixtures of normal and tumor cells, experimental noise or other technical limitations. With the reduction in SNR, many false CNA regions are often detected and the true CNA regions are missed. Thus, more sophisticated statistical models are needed to make the CNAs detection, using the low SNR signals, more robust and reliable.     

An expert system model for mapping tropical wetlands and peatlands reveals South America as the largest contributor

Wetlands are important providers of ecosystem services and key regulators of climate change. They positively contribute to global warming through their greenhouse gas emissions, and negatively through the accumulation of organic material in histosols, particularly in peatlands. Our understanding of wetlands’ services is currently constrained by limited knowledge on their distribution, extent, volume, interannual flood variability and disturbance levels. We present an expert system approach to estimate wetland and peatland areas, depths and volumes, which relies on three biophysical indices related to wetland and peat formation: (1) long‐term water supply exceeding atmospheric water demand; (2) annually or seasonally water‐logged soils; and (3) a geomorphological position where water is supplied and retained. Tropical and subtropical wetlands estimates reach 4.7 million km² (Mkm²). In line with current understanding, the American continent is the major contributor (45%), and Brazil, with its Amazonian interfluvial region, contains the largest tropical wetland area (800,720 km²). Our model suggests, however, unprecedented extents and volumes of peatland in the tropics (1.7 Mkm² and 7,268 (6,076–7,368) km³), which more than threefold current estimates. Unlike current understanding, our estimates suggest that South America and not Asia contributes the most to tropical peatland area and volume (ca. 44% for both) partly related to some yet unaccounted extended deep deposits but mainly to extended but shallow peat in the Amazon Basin. Brazil leads the peatland area and volume contribution. Asia hosts 38% of both tropical peat area and volume with Indonesia as the main regional contributor and still the holder of the deepest and most extended peat areas in the tropics. Africa hosts more peat than previously reported but climatic and topographic contexts leave it as the least peat‐forming continent. Our results suggest large biases in our current understanding of the distribution, area and volumes of tropical peat and their continental contributions.     

A neural mechanism for discrimination: II. Discrimination of weights

A theoretical central mechanism for the discrimination of intensities as previously developed, together with plausible assumptions concerning the receptors, are employed for the derivation of the discriminable difference between lifted weights as a function of the smaller of these weights. The function so derived depends upon three parameters, one parameter being the weight of the supporting member. Some empirical data are compared with the theoretical predictions, and a few remarks are added to describe the physiological significance of the parameters.     

A note on the diffusion of electrolytes in cells

A somewhat simpler solution is given to the problem previously discussed by R. R. Williamson relating to the diffusion of a metabolized electrolyte whose ions have different mobilities.