Dynamics of Electron Localization in Warm vs. Cold Water Clusters

The process of electron localization on a cluster of 32 water molecules at 20, 50, and 300~K is unraveled using ab initio molecular dynamics simulations. In warm, liquid clusters, the excess electron relaxes from an initial diffuse and weakly bound structure to an equilibrated, strongly bound species within 1.5 ps. In contrast, on cold, glassy clusters the relaxation processes is not completed and the electron becomes trapped in a metastable surface state with an intermediate binding energy. These results question the validity of extrapolations of the properties of solvated electrons from cold clusters of increasing size to the liquid bulk

The SIRT1 promoter polymorphic site rs12778366 increases IL-6 related human mortality in the prospective study “Treviso Longeva (TRELONG)”

Studies on sirtuins (SIRT), a family of proteins with deacetylase activity, have provided convergent evidence of the key role of these enzymes in aging-linked physiological functions. The link between SIRT1 and longevity has emerged in model organism but few data are available in humans, in particular relying on longitudinal studies. Here, we assessed whether a genetic variant within SIRT1 gene promoter (rs12778366) was associated to human longevity. We analyzed 586 genomic DNA (gDNA) collected in the study "Treviso Longeva" (TRELONG), including elderly over 70 years of age from the municipality of Treviso, a town in the Northeast of Italy, with a 11-year follow-up. We genotyped SIRT1 rs12778366 by real-time polymerase chain reaction (RT-PCR) allelic discrimination assay. A cross-sectional analysis performed by comparing people over and under 85 years of age did not evidence association between rs12778366 and longevity. When we performed a longitudinal analysis considering mortality as dependent variable, we did not observe an association of rs12778366 with longevity in the whole population (corrected P-value = 0.33). However, when we stratified the TRELONG subjects according to circulating level of interleukin-6 (IL-6), a predictor of disability and mortality, we found that rs12778366 (TC+CC) carriers were at increased risk of mortality in comparison to the TT reference group (corrected P-value = 0.03, HR 1.47). Our data do not support a major role of rs12778366 in human longevity, but the stratified analysis on IL-6 suggests that this variant may be involved in the detrimental effect of high circulating IL-6 in the elderly

A Blind Circadian Clock in Cavefish Reveals that Opsins Mediate Peripheral Clock Photoreception

Evolution during millions of years in perpetual darkness leads to mutations in non-visual opsin genes (Melanopsin and TMT opsin) and an aberrant, blind circadian clock in cavefish

An ab initio and AIM investigation into the hydration of 2-thioxanthine

<p>Abstract</p> <p>Background</p> <p>Hydration is a universal phenomenon in nature. The interactions between biomolecules and water of hydration play a pivotal role in molecular biology. 2-Thioxanthine (2TX), a thio-modified nucleic acid base, is of significant interest as a DNA inhibitor yet its interactions with hydration water have not been investigated either computationally or experimentally. Here in, we reported an <it>ab initio </it>study of the hydration of 2TX, revealing water can form seven hydrated complexes.</p> <p>Results</p> <p>Hydrogen-bond (H-bond) interactions in 1:1 complexes of 2TX with water are studied at the MP2/6-311G(d, p) and B3LYP/6-311G(d, p) levels. Seven 2TX^...H₂O hydrogen bonded complexes have been theoretically identified and reported for the first time. The proton affinities (PAs) of the O, S, and N atoms and deprotonantion enthalpies (DPEs) of different N-H bonds in 2TX are calculated, factors surrounding why the seven complexes have different hydrogen bond energies are discussed. The theoretical infrared and NMR spectra of hydrated 2TX complexes are reported to probe the characteristics of the proposed H-bonds. An improper blue-shifting H-bond with a shortened C-H bond was found in one case. NBO and AIM analysis were carried out to explain the formation of improper blue-shifting H-bonds, and the H-bonding characteristics are discussed.</p> <p>Conclusion</p> <p>2TX can interact with water by five different H-bonding regimes, N-H^...O, O-H^...N, O-H^...O, O-H^...S and C-H^...O, all of which are medium strength hydrogen bonds. The most stable H-bond complex has a closed structure with two hydrogen bonds (N(7)-H^...O and O-H^...O), whereas the least stable one has an open structure with one H-bond. The interaction energies of the studied complexes are correlated to the PA and DPE involved in H-bond formation. After formation of H-bonds, the calculated IR and NMR spectra of the 2TX-water complexes change greatly, which serves to identify the hydration of 2TX.</p

A Fear-Inducing Odor Alters PER2 and c-Fos Expression in Brain Regions Involved in Fear Memory

Evidence demonstrates that rodents learn to associate a foot shock with time of day, indicating the formation of a fear related time-stamp memory, even in the absence of a functioning SCN. In addition, mice acquire and retain fear memory better during the early day compared to the early night. This type of memory may be regulated by circadian pacemakers outside of the SCN. As a first step in testing the hypothesis that clock genes are involved in the formation of a time-stamp fear memory, we exposed one group of mice to fox feces derived odor (TMT) at ZT 0 and one group at ZT 12 for 4 successive days. A separate group with no exposure to TMT was also included as a control. Animals were sacrificed one day after the last exposure to TMT, and PER2 and c-Fos protein were quantified in the SCN, amygdala, hippocampus, and piriform cortex. Exposure to TMT had a strong effect at ZT 0, decreasing PER2 expression at this time point in most regions except the SCN, and reversing the normal rhythm of PER2 expression in the amygdala and piriform cortex. These changes were accompanied by increased c-Fos expression at ZT0. In contrast, exposure to TMT at ZT 12 abolished the rhythm of PER2 expression in the amygdala. In addition, increased c-Fos expression at ZT 12 was only detected in the central nucleus of the amygdala in the TMT12 group. TMT exposure at either time point did not affect PER2 or c-Fos in the SCN, indicating that under a light-dark cycle, the SCN rhythm is stable in the presence of repeated exposure to a fear-inducing stimulus. Taken together, these results indicate that entrainment to a fear-inducing stimulus leads to changes in PER2 and c-Fos expression that are detected 24 hours following the last exposure to TMT, indicating entrainment of endogenous oscillators in these regions. The observed effects on PER2 expression and c-Fos were stronger during the early day than during the early night, possibly to prepare appropriate systems at ZT 0 to respond to a fear-inducing stimulus

A distributed model of interconnected simulators to control the supply chain in a stochastic configuration

When changes are made in a final assembly, they normally occur in response to schedule variations, which are magnified throughout the line and the supply chain. Making the smallest possible adjustments and setting a fixed monthly production plan, for which the output rate remains constant, usually solves the problem. A possible approach to manage production lines, inventories and the supply-chain in dynamic condition is possible by using a network of on-line interconnected simulators able to react quickly to variations in requests, focusing on long-term partnerships with suppliers and customers. Modular interconnected models attempt to devise solutions by involving all supplier networks, seeking information and focusing on virtual vertical integration. Simulation models concentrate on strategic planning instead of operating control. In this paper architecture specifications will be showed to define the overarching framework in terms of the construction and execution