368 research outputs found

    The Neurological Ecology of Fear: Insights Neuroscientists and Ecologists Have to Offer one Another

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    That the fear and stress of life-threatening experiences can leave an indelible trace on the brain is most clearly exemplified by post-traumatic stress disorder (PTSD). Many researchers studying the animal model of PTSD have adopted utilizing exposure to a predator as a life-threatening psychological stressor, to emulate the experience in humans, and the resulting body of literature has demonstrated numerous long-lasting neurological effects paralleling those in PTSD patients. Even though much more extreme, predator-induced fear and stress in animals in the wild was, until the 1990s, not thought to have any lasting effects, whereas recent experiments have demonstrated that the effects on free-living animals are sufficiently long-lasting to even affect reproduction, though the lasting neurological effects remain unexplored. We suggest neuroscientists and ecologists both have much to gain from collaborating in studying the neurological effects of predator-induced fear and stress in animals in the wild. We outline the approaches taken in the lab that appear most readily translatable to the field, and detail the advantages that studying animals in the wild can offer researchers investigating the “predator model of PTSD.

    Cytotoxic Hydrogen Bridged Ruthenium Quinaldamide Complexes Showing Induced Cancer Cell Death by Apoptosis

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    This report presents the first known p-cymene ruthenium quinaldamide complexes which are stablized by a hydrogenbridging atom, [[{(p-cym)RuIIX(N,N)}{H+ }{(N,N)XRuII(p-cym)}][PF6] (N,N = functionalised quinaldamide and X = Cl or Br). These complexes are formed by a reaction of [p-cymRu(-X)2]2 with a functionalised quinaldamide ligand. When filtered over NH4PF6, and under aerobic conditions the equilibrium of NH4PF6 NH3 + HPF6 enables incorporation of HPF6 and the stabilisation of two monomeric ruthenium complexes by a bridging H+ , which are counter-balanced by a PF6 counterion. Xray crystallographic analysis is presented for six new structures with O···O distances of 2.430(3)-2.444(17) Å, which is significant for strong hydrogen bonds. Chemosensitivity studies against HCT116, A2780 and cisplatin-resistant A2780cis human cancer cells showed the ruthenium complexes with a bromide ancillary ligand to be more potent than those with a chloride ligand. The 4'-fluoro compounds show a reduction in potency for both chloride and bromide complexes against all cell lines, but an increase in selectivity towards cancer cells compared to non-cancer ARPE-19 cells, with a selectivity index > 1. Mechanistic studies showed a clear correlation between IC50 values and induction of cell death by apoptosis

    Promoter-Wide Hypermethylation of the Ribosomal RNA Gene Promoter in the Suicide Brain

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    BACKGROUND: Alterations in gene expression in the suicide brain have been reported and for several genes DNA methylation as an epigenetic regulator is thought to play a role. rRNA genes, that encode ribosomal RNA, are the backbone of the protein synthesis machinery and levels of rRNA gene promoter methylation determine rRNA transcription. METHODOLOGY/PRINCIPAL FINDINGS: We test here by sodium bisulfite mapping of the rRNA promoter and quantitative real-time PCR of rRNA expression the hypothesis that epigenetic differences in critical loci in the brain are involved in the pathophysiology of suicide. Suicide subjects in this study were selected for a history of early childhood neglect/abuse, which is associated with decreased hippocampal volume and cognitive impairments. rRNA was significantly hypermethylated throughout the promoter and 5' regulatory region in the brain of suicide subjects, consistent with reduced rRNA expression in the hippocampus. This difference in rRNA methylation was not evident in the cerebellum and occurred in the absence of genome-wide changes in methylation, as assessed by nearest neighbor. CONCLUSIONS/SIGNIFICANCE: This is the first study to show aberrant regulation of the protein synthesis machinery in the suicide brain. The data implicate the epigenetic modulation of rRNA in the pathophysiology of suicide

    Data to support study of Heteroleptic Iron(II) Complexes of Chiral 2,6-Bis(oxazolin-2-yl)-pyridine (PyBox) and 2,6-Bis(thiazolin-2-yl)pyridine Ligands ‒ the Interplay of Two Different Ligands on the Metal Ion Spin State

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    The spin-crossover properties of [Fe(LR)L][ClO4]2 (LR = a chiral PyBox {L1R} or ThioPyBox {L2R} derivative) show subtle differences depending on the tridentate ‘L’ co-ligand

    Single neutral pion production by charged-current νˉμ\bar{\nu}_\mu interactions on hydrocarbon at ⟨Eν⟩=\langle E_\nu \rangle = 3.6 GeV

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    Single neutral pion production via muon antineutrino charged-current interactions in plastic scintillator (CH) is studied using the \minerva detector exposed to the NuMI low-energy, wideband antineutrino beam at Fermilab. Measurement of this process constrains models of neutral pion production in nuclei, which is important because the neutral-current analog is a background for νˉe\bar{\nu}_e appearance oscillation experiments. The differential cross sections for π0\pi^0 momentum and production angle, for events with a single observed π0\pi^0 and no charged pions, are presented and compared to model predictions. These results comprise the first measurement of the π0\pi^0 kinematics for this process.Comment: 6 pages, 5 figures, submitted to Physics Letters

    Data to support study of The Spin States of Diastereomeric Iron(II)/Bis[2,6-Di(thiazolin-2-yl)-pyridine] (ThioPyBox) Complexes, and a Comparison with the Corresponding PyBox Derivatives

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    Diastereomeric [Fe(L1R)2][ClO4]2 (R = Ph, iPr) iron(II)/ThioPyBox derivatives show a larger discrimination of their spin states than the corresponding [Fe(L2R)2][ClO4]2 PyBox complexe

    MINERvA neutrino detector response measured with test beam data

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    The MINERvA collaboration operated a scaled-down replica of the solid scintillator tracking and sampling calorimeter regions of the MINERvA detector in a hadron test beam at the Fermilab Test Beam Facility. This article reports measurements with samples of protons, pions, and electrons from 0.35 to 2.0 GeV/c momentum. The calorimetric response to protons, pions, and electrons are obtained from these data. A measurement of the parameter in Birks' law and an estimate of the tracking efficiency are extracted from the proton sample. Overall the data are well described by a Geant4-based Monte Carlo simulation of the detector and particle interactions with agreements better than 4%, though some features of the data are not precisely modeled. These measurements are used to tune the MINERvA detector simulation and evaluate systematic uncertainties in support of the MINERvA neutrino cross section measurement program.Comment: as accepted by NIM
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