2,230 research outputs found

    Impact of vegetation on the simulation of seasonal monsoon rainfall over the Indian subcontinent using a regional model

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    The change in the type of vegetation fraction can induce major changes in the local effects such as local evaporation, surface radiation, etc., that in turn induces changes in the model simulated outputs. The present study deals with the effects of vegetation in climate modeling over the Indian region using the MM5 mesoscale model. The main objective of the present study is to investigate the impact of vegetation dataset derived from SPOT satellite by ISRO (Indian Space Research Organization) versus that of USGS (United States Geological Survey) vegetation dataset on the simulation of the Indian summer monsoon. The present study has been conducted for five monsoon seasons (1998-2002), giving emphasis over the two contrasting southwest monsoon seasons of 1998 (normal) and 2002 (deficient). The study reveals mixed results on the impact of vegetation datasets generated by ISRO and USGS on the simulations of the monsoon. Results indicate that the ISRO data has a positive impact on the simulations of the monsoon over northeastern India and along the western coast. The MM5- USGS has greater tendency of overestimation of rainfall. It has higher standard deviation indicating that it induces a dispersive effect on the rainfall simulation. Among the five years of study, it is seen that the RMSE of July and JJAS (June-July-August-September) for All India Rainfall is mostly lower for MM5-ISRO. Also, the bias of July and JJAS rainfall is mostly closer to unity for MM5-ISRO. The wind fields at 850 hPa and 200 hPa are also better simulated by MM5 using ISRO vegetation. The synoptic features like Somali jet and Tibetan anticyclone are simulated closer to the verification analysis by ISRO vegetation. The 2 m air temperature is also better simulated by ISRO vegetation over the northeastern India, showing greater spatial variability over the region. However, the JJAS total rainfall over north India and Deccan coast is better simulated using the USGS vegetation. Sensible heat flux over north-west India is also better simulated by MM5-USGS

    Chiral Polymerization in Open Systems From Chiral-Selective Reaction Rates

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    We investigate the possibility that prebiotic homochirality can be achieved exclusively through chiral-selective reaction rate parameters without any other explicit mechanism for chiral bias. Specifically, we examine an open network of polymerization reactions, where the reaction rates can have chiral-selective values. The reactions are neither autocatalytic nor do they contain explicit enantiomeric cross-inhibition terms. We are thus investigating how rare a set of chiral-selective reaction rates needs to be in order to generate a reasonable amount of chiral bias. We quantify our results adopting a statistical approach: varying both the mean value and the rms dispersion of the relevant reaction rates, we show that moderate to high levels of chiral excess can be achieved with fairly small chiral bias, below 10%. Considering the various unknowns related to prebiotic chemical networks in early Earth and the dependence of reaction rates to environmental properties such as temperature and pressure variations, we argue that homochirality could have been achieved from moderate amounts of chiral selectivity in the reaction rates.Comment: 15 pages, 6 figures, accepted for publication in Origins of Life and Evolution of Biosphere

    Cell cycle progression or translation control is not essential for vesicular stomatitis virus oncolysis of hepatocellular carcinoma.

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    The intrinsic oncolytic specificity of vesicular stomatitis virus (VSV) is currently being exploited to develop alternative therapeutic strategies for hepatocellular carcinoma (HCC). Identifying key regulators in diverse transduction pathways that define VSV oncolysis in cancer cells represents a fundamental prerequisite to engineering more effective oncolytic viral vectors and adjusting combination therapies. After having identified defects in the signalling cascade of type I interferon induction, responsible for attenuated antiviral responses in human HCC cell lines, we have now investigated the role of cell proliferation and translation initiation. Cell cycle progression and translation initiation factors eIF4E and eIF2Bepsilon have been recently identified as key regulators of VSV permissiveness in T-lymphocytes and immortalized mouse embryonic fibroblasts, respectively. Here, we show that in HCC, decrease of cell proliferation by cell cycle inhibitors or siRNA-mediated reduction of G(1) cyclin-dependent kinase activities (CDK4) or cyclin D1 protein expression, do not significantly alter viral growth. Additionally, we demonstrate that translation initiation factors eIF4E and eIF2Bepsilon are negligible in sustaining VSV replication in HCC. Taken together, these results indicate that cellular proliferation and the initiation phase of cellular protein synthesis are not essential for successful VSV oncolysis of HCC. Moreover, our observations indicate the importance of cell-type specificity for VSV oncolysis, an important aspect to be considered in virotherapy applications in the future

    An overview of anthropogenic electromagnetic radiations as risk to pollinators and pollination

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    Pollinators play a key functional role in most terrestrial ecosystems and provide important ecosystem service to maintain wild plant communities and agricultural productivity. The decline in pollinators has been related to anthropogenic disturbances such as habitat loss, alterations in land use, and climate change. The surge in mobile telephony has led to a marked increase in electromagnetic fields in the atmosphere, which may affect pollinator and pollination. Several laboratory studies have reported negative effects of electromagnetic radiation on reproduction, development, and navigation in insects. The abundance of insects such as the beetle, wasp, and hoverfly, decreased with electromagnetic radiation(EMR), whereas the abundance of underground-nesting wild bees and bee fly unexpectedly increased with EMR. Potential risks for pollinators and biodiversity are anthropogenic radiofrequency electromagnetic radiation (AREMR) (light, radiofrequency). Artificial light at night (ALAN) can alter the function and abundance of pollinator. Evidence of impacts of AREMR is not adequate due to a lack of high quality, field-realistic studies. Whether pollinators experiencing a threat of ALAN or AREMR, while major knowledge gap exists. In this review, the effects of EMR on wild pollinator groups such as wild bees, hoverflies, bee flies, beetles, butterflies, and wasps etc. have been highlighted. Researchers are also recommended for further study on the effects of EMR on insects. This study will be significant to conserve pollinators and other important insects.

    A review of stochastic dynamic method of weather prediction

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    The stochastic dynamic method of weather prediction (SDP) has been suggested recently for better understanding of the numerical weather prediction. The SDP is described using a simple one-dimensional advection equation. The salient features of the method, its scope and limitations, are discussed

    Risk factors for mortality and injury: post-tsunami epidemiological findings from Tamil Nadu

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    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Cultures of entitlement and social protection: Evidence from flood prone Bahraich, Uttar Pradesh, India

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    Sen’s entitlement thesis rooted in social contract theory has been used to explain access to food, and is used by states to design social protection programs as transfer entitlements to diffuse food insecurities. Social protection programs have now burgeoned in several countries as a strategy to enable the poor to overcome risks, vulnerabilities and poverty. These social protection programs have inclusion and exclusion errors, which current theorization attributes mainly to political clientalism, social vulnerability, elite capture, targeting inefficiency, leakages and corruption, lack of information transparency and improper designing of social protection programs. This paper argues that the errors are due to a more fundamental assumption made in application of social contract and entitlement-based approach to social protection programing. It identifies an uncritical application of Sen’s entitlement thesis to social protection programs, as leading to inclusion and exclusion errors. The main problematic, the paper shows is that the social contract-led entitlement thesis works within the domain of formal rights situated within the state-citizen relations, and as such, misses out on the non-formal entitlements and non-state influences that impact materialization of social protection programs in practice. Evidences from flood prone Bahraich, Uttar Pradesh, India indicate that non-state rules linked with clientele and patronage relations, moral and local political economies trump over formal rights to mediate social protection entitlement outcomes. Rather than abstract state-citizen social contract, it is the moral contracts of reciprocal exchanges with influential patrons embedded in the moral economy of the villages that ultimately ground the social protection entitlement claims of poor villagers. Conceptualizing this process of access as cultures of entitlement, the paper builds a framework for reinterpretation of entitlements and their outcomes, suggesting a recalibration of application of Sen’s entitlement thesis to social protection programs. In conclusion it argues that Sen’s entitlement thesis which is pitched at transfer of economic resources through social protection from the state to the poor is inadequate. Learning from social movements currently leading the transparency and accountability struggles in India, it calls for an instituting and recognition of accountability as new cultural resource and entitlement. In conclusion it argues that information, and accountability as new cultural entitlements, when mobilized through collective agency of the poor can potentially challenge the current cultures of entitlements evidenced in this paper that presently underlie social protection outcomes
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