220 research outputs found

    Effect of naturally occurring bromophenols on sulfate reduction and ammonia oxidation in intertidal sediments

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    We examined the effect on ammonium oxidation and sulfate reduction of several brominated compounds [4-bromophenol, 2,4-dibromophenol (2,4-DBP), 2,6-dibromophenol and 2,4,6-tribromophenol] that occur naturally in enteropneusts. We compared rates of these processes with and without bromoorganics using bulk intertidal sediments and burrow wall sediments from 3 enteropneust species (2 containing 2,4-DBP and 1 containing 2,3,4-tribromopyrrole), a mollusc (Mya arenaria) and a polychaete (Nereis virens). Sulfate reduction in bulk sediment was unaffected by bromophenols at concentrations sediment, but was inhibited temporarily at 1 μmol cm-3. Sulfate reduction in burrow wall sediments differed from bulk sediments, but was not correlated with concentrations of naturally occurring bromophenols. Ammonium oxidation was inhibited in surface sediments by bromophenol concentrations as low as 1 nmol cm-3 sediment. Ammonium oxidation was enhanced in burrow wall sediments of N. virens, M. arenaria and the enteropneust Saccoglossus bromophenolosus relative to surface sediments, but was markedly lower and negatively correlated with ambient 2,4-DBP in burrow wall sediments of a second enteropneust, Protoglossus graveolens

    Energy related public environmental concerns and intra-firm pay gap in polluting enterprises: Evidence from China

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    YesThis study empirically investigates the impact of energy related public environmental concerns on the pay gap within polluting companies. It uses the extreme environmental event of the PM2.5 surge at the end of 2011, which led to an upsurge in energy related public environmental concerns in China, as a quasi-natural experiment. According to our findings, energy related public environmental concerns lead to a significant increase in the executive–employee pay gap of polluting companies compared to that of non-polluting companies, owing to a significant increase in executive compensation and no significant change in employee income. The effect of energy related public environmental concerns on increasing the pay gap within polluting companies is more significant in samples with high agency costs, poor information transparency, less analyst follow-up, and fewer institutional investors' shareholding. Furthermore, as energy related public environmental concerns exacerbate the polluting firms' internal pay gap, their total factor productivity and investment efficiency fall significantly. In summary, energy related public environmental concerns not only widen the wage gap within polluting enterprises but also worsen their operational and investment efficiency, which has important policy implications for emerging market economies seeking to balance environmental protection and economic development.The authors wew funded by NSFC number (71903199), Fujian Pro vincial Federation of Social Sciences (FJ2023BF045), Guangdong Phi losophy and Social Sciences Project (GD23XYJ08), the Innovation and Talent Base for Digital Technology and Finance (B21038), and "the Fundamental Research Funds for the Central Universities", Zhongnan Univeristy of Economics and Law (2722023EJ002)

    Chemical analysis of Cd12xZnxS/CdTe solar cells by plasma profiling TOFMS

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    Thin film CdTe photovoltaic (PV) devices and reference layers obtained by the atmospheric pressure metalorganic vapour deposition (AP-MOCVD) method have been studied for their chemical structure using plasma profiling time-of-flight-mass spectroscopy (PP-TOFMS, also called glow discharge TOFMS). Different levels of arsenic (As) dopant in CdTe films were measured by PP-TOFMS and compared to results obtained from a more conventional depth profiling method (secondary ion mass spectrometry or SIMS). This comparison showed that PPTOFMS has the sufficient sensitivity towards detection of the As dopant in CdTe and hence is suited as a rapid, low vacuum tool in controlling the large scale production of CdTe PV materials

    Cholesterol-recognition motifs in the transmembrane domain of the tyrosine kinase receptor family : The case of TRKB

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    Cholesterol is an essential constituent of cell membranes. The discovery of cholesterol-recognition amino acid consensus (CRAC) motif in proteins indicated a putative direct, non-covalent interaction between cholesterol and proteins. In the present study, we evaluated the presence of a CRAC motif and its inverted version (CARC) in the transmembrane region (TMR) of the tyrosine kinase receptor family (RTK) in several species using in silico methods. CRAC motifs were found across all species analyzed, while CARC was found only in vertebrates. The tropomyosin-related kinase B (TRKB), a member of the RTK family, through interaction with its endogenous ligand brain-derived neurotrophic factor (BDNF) is a core participant in the neuronal plasticity process and exhibits a CARC motif in its TMR. Upon identifying the conserved CARC motif in the TRKB, we performed molecular dynamics simulations of the mouse TRKB.TMR. The simulations indicated that cholesterol interaction with the TRKB CARC motif occurs mainly at the central Y433 residue. Our binding assay suggested a bell-shaped effect of cholesterol on BDNF interaction with TRKB receptors, and our results suggest that CARC/CRAC motifs may play a role in the function of the RTK family TMR.Peer reviewe

    An Experimental Analysis of RowHammer in HBM2 DRAM Chips

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    RowHammer (RH) is a significant and worsening security, safety, and reliability issue of modern DRAM chips that can be exploited to break memory isolation. Therefore, it is important to understand real DRAM chips' RH characteristics. Unfortunately, no prior work extensively studies the RH vulnerability of modern 3D-stacked high-bandwidth memory (HBM) chips, which are commonly used in modern GPUs. In this work, we experimentally characterize the RH vulnerability of a real HBM2 DRAM chip. We show that 1) different 3D-stacked channels of HBM2 memory exhibit significantly different levels of RH vulnerability (up to 79% difference in bit error rate), 2) the DRAM rows at the end of a DRAM bank (rows with the highest addresses) exhibit significantly fewer RH bitflips than other rows, and 3) a modern HBM2 DRAM chip implements undisclosed RH defenses that are triggered by periodic refresh operations. We describe the implications of our observations on future RH attacks and defenses and discuss future work for understanding RH in 3D-stacked memories.Comment: To appear at DSN Disrupt 202

    Lawmakers\u27 Use of Scientific Evidence Can Be Improved

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    Core to the goal of scientific exploration is the opportunity to guide future decision-making. Yet, elected officials often miss opportunities to use science in their policymaking. This work reports on an experiment with the US Congress-evaluating the effects of a randomized, dual-population (i.e., researchers and congressional offices) outreach model for supporting legislative use of research evidence regarding child and family policy issues. In this experiment, we found that congressional offices randomized to the intervention reported greater value of research for understanding issues than the control group following implementation. More research use was also observed in legislation introduced by the intervention group. Further, we found that researchers randomized to the intervention advanced their own policy knowledge and engagement as well as reported benefits for their research following implementation

    Fast Visuomotor Processing of Redundant Targets: The Role of the Right Temporo-Parietal Junction

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    Parallel processing of multiple sensory stimuli is critical for efficient, successful interaction with the environment. An experimental approach to studying parallel processing in sensorimotor integration is to examine reaction times to multiple copies of the same stimulus. Reaction times to bilateral copies of light flashes are faster than to single, unilateral light flashes. These faster responses may be due to ‘statistical facilitation’ between independent processing streams engaged by the two copies of the light flash. On some trials, however, reaction times are faster than predicted by statistical facilitation. This indicates that a neural ‘coactivation’ of the two processing streams must have occurred. Here we use fMRI to investigate the neural locus of this coactivation. Subjects responded manually to the detection of unilateral light flashes presented to the left or right visual hemifield, and to the detection of bilateral light flashes. We compared the bilateral trials where subjects' reaction times exceeded the limit predicted by statistical facilitation to bilateral trials that did not exceed the limit. Activity in the right temporo-parietal junction was higher in those bilateral trials that showed coactivation than in those that did not. These results suggest the neural coactivation observed in visuomotor integration occurs at a cognitive rather than sensory or motor stage of processing

    Impact of In-Situ Cd Saturation MOCVD Grown CdTe Solar Cells on As Doping and VOC

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    In-situ Cd-saturated growth of polycrystalline CdTe:As thin film was performed by metal organic chemical vapour deposition at a low temperature of 350 °C, to investigate the impact on As doping and device VOC. Device characterization showed conversion efficiency of ∼14%, and VOC of 772 mV, which is an improvement to the baseline device with CdTe:As absorber layer grown at 390 °C under non-saturated conditions. When the low temperature Cd-saturated growth was combined with chlorine heat treatment at a higher temperature of 440 °C (in contrast with the standard 420 °C) for 10 min, device efficiency improved to ∼17% with a high VOC of 877 mV. As a result, ∼100 mV boost in VOC from baseline is demonstrated with Cd-saturated CdTe:As device. Micro-photoluminescence and time-resolved photoluminescence measurements performed on these Cd-saturated CdTe:As devices confirmed that minority carrier lifetime significantly improved
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