2,976 research outputs found

    Low-threshold analysis of CDMS shallow-site data

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    Data taken during the final shallow-site run of the first tower of the Cryogenic Dark Matter Search (CDMS II) detectors have been reanalyzed with improved sensitivity to small energy depositions. Four ~224 g germanium and two ~105 g silicon detectors were operated at the Stanford Underground Facility (SUF) between December 2001 and June 2002, yielding 118 live days of raw exposure. Three of the germanium and both silicon detectors were analyzed with a new low-threshold technique, making it possible to lower the germanium and silicon analysis thresholds down to the actual trigger thresholds of ~1 and ~2 keV, respectively. Limits on the spin-independent cross section for weakly interacting massive particles (WIMPs) to elastically scatter from nuclei based on these data exclude interesting parameter space for WIMPs with masses below 9 GeV/c^2. Under standard halo assumptions, these data partially exclude parameter space favored by interpretations of the DAMA/LIBRA and CoGeNT experiments’ data as WIMP signals, and exclude new parameter space for WIMP masses between 3 and 4 GeV/c^2

    Combined limits on WIMPs from the CDMS and EDELWEISS experiments

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    The CDMS and EDELWEISS collaborations have combined the results of their direct searches for dark matter using cryogenic germanium detectors. The total data set represents 614  kg·days equivalent exposure. A straightforward method of combination was chosen for its simplicity before data were exchanged between experiments. The results are interpreted in terms of limits on spin-independent weakly interacting, massive particle (WIMP)-nucleon cross section. For a WIMP mass of 90  GeV/c^2, where this analysis is most sensitive, a cross section of 3.3×10^(-44)  cm^2 is excluded at 90% C.L. At higher WIMP masses, the combination improves the individual limits, by a factor 1.6 above 700  GeV/c^2. Alternative methods of combining the data provide stronger constraints for some ranges of WIMP masses and weaker constraints for others

    Search for inelastic dark matter with the CDMS II experiment

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    Results are presented from a reanalysis of the entire five-tower data set acquired with the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory, with an exposure of 969 kg-days. The analysis window was extended to a recoil energy of 150 keV, and an improved surface-event background-rejection cut was defined to increase the sensitivity of the experiment to the inelastic dark matter (iDM) model. Three dark matter candidates were found between 25 keV and 150 keV. The probability to observe three or more background events in this energy range is 11%. Because of the occurrence of these events, the constraints on the iDM parameter space are slightly less stringent than those from our previous analysis, which used an energy window of 10–100 keV

    Cancer microenvironment and endoplasmic reticulum stress response

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    Different stressful conditions such as hypoxia, nutrient deprivation, pH changes, or reduced vascularization, potentially able to act as growth-limiting factors for tumor cells, activate the unfolded protein response (UPR). UPR is therefore involved in tumor growth and adaptation to severe environments and is generally cytoprotective in cancer. The present review describes the molecular mechanisms underlying UPR and able to promote survival and proliferation in cancer. The critical role of UPR activation in tumor growth promotion is discussed in detail for a few paradigmatic tumors such as prostate cancer and melanoma

    The role of statistical significance testing in public law and health risk assessment

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    Following a fundamental statement made in 2016 by the American Statistical Associations and broad and consistent changes in data analysis and interpretation methodology in public health and other sciences, statistical significance/null hypothesis testing is being increasingly criticized and abandoned in the reporting and interpretation of the results of biomedical research. This shift in favor of a more comprehensive and non-dichotomous approach in the assessment of causal relationships may have a major impact on human health risk assessment. It is interesting to see, however, that authoritative opinions by the Supreme Court of the United States and European regulatory agencies have somehow anticipated this tide of criticism of statistical significance testing, thus providing additional support to its demise. Current methodological evidence further warrants abandoning this approach in both the biomedical and public law contexts, in favor of a more comprehensive and flexible method of assessing the effects of toxicological exposure on human and environmental health

    Assessment of multiaxial fatigue life prediction methodologies for Inconel 718

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    Abstract Fatigue life prediction methodologies for the assessment of the structural integrity of safety critical components in modern turbine engines require a close integration of advanced multiaxial fatigue life prediction procedures and of specific multiaxial tests, representative of the service conditions of turbine engine components and materials. The objective of the research work presented in this paper is to extend currently employed methodologies for the assessment of fatigue strength of turbine engines disks by integrating suitable multiaxial fatigue criteria and test results of multiaxial fatigue experiments conducted on Inconel 718 material at temperatures similar to those experienced by the disc materials during service. Smooth tubular specimens of Inconel 718 have been employed for conducting tension/torsion strain controlled high temperature fatigue tests. Specimens have been cut out from forged parts utilised for the production of engine discs, thus preserving the typical properties of disc materials (microstructure, basic mechanical properties, etc.). Different models/criteria have been evaluated by comparing fatigue life predictions and multiaxial fatigue experiments. It's well known that agreement of life predictions with experimental life is strongly affected not only by the choice of the multiaxial fatigue criteria but also by the way the reference fatigue data are integrated in the criteria. Therefore, specific multiaxial fatigue tests have been carried out, in order to validate and to improve the assessment capabilities of the lifing procedures. Moreover, multiaxial fatigue tests permit advances in the basic understanding of materials behaviour that might be utilised in the processes of declaring component service lives

    Measurement-based Energy Consumption Profiling of Mobile Radio Networks

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    Abstract —The exponential growth of mobile traffic is forcing operators to increase quickly the capacity of their network and extend it with new technologies and improved topologies, such as heterogeneous layouts with small cells. However, since revenues cannot grow at the same rate of traffic, the main challenge is to manage capacity expansion with reduced costs. In addi- tion to fixed costs for the new network infrastructures, operational costs are becoming critical, mainly for en- ergy bill component. Moreover, the carbon footprint of mobile access networks is considered one of the largest of the whole ICT (Information and Communications Technology) sector and its reduction is fundamental for the environmental sustainability of the Internet economy. Due to these reasons, improving the energy efficiency of the access network is crucial for mobile operators. In order to do that, monitoring the energy consumption of the network components and defining models of energy profile are valuable approaches for es- timating energy costs and identifying the most efficient configurations. In this paper, we present an energy consumption monitoring system that has been designed and im- plemented in three different countries using separate sensors for the radio and base-band components of second, third and fourth generation systems. We also propose an energy profiling approach that simplifies the characterization of the different components and allows the estimation of the energy efficiency based on traffic statistics

    Granulocyte transfusions in children and adults with hematological malignancies: benefits and controversies

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    Bacterial and fungal infections continue to pose a major clinical challenge in patients with prolonged severe neutropenia after chemotherapy or hematopoietic stem cell transplantation (HSCT). With the advent of granulocyte colony-stimulating factor (G-CSF) to mobilize neutrophils in healthy donors, granulocyte transfusions have been broadly used to prevent and/or treat life-threatening infections in patients with severe febrile neutropenia and/or neutrophil dysfunction. Although the results of randomized controlled trials are inconclusive, there are suggestions from pilot and retrospective studies that granulocyte transfusions may benefit selected categories of patients. We will critically appraise the evidence related to the use of therapeutic granulocyte transfusions in children and adults, highlighting current controversies in the field and discussing complementary approaches to modulate phagocyte function in the host
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