186 research outputs found

    Limits on Dark Matter Effective Field Theory Parameters with CRESST-II

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    CRESST is a direct dark matter search experiment, aiming for an observation of nuclear recoils induced by the interaction of dark matter particles with cryogenic scintillating calcium tungstate crystals. Instead of confining ourselves to standard spin-independent and spin-dependent searches, we re-analyze data from CRESST-II using a more general effective field theory (EFT) framework. On many of the EFT coupling constants, improved exclusion limits in the low-mass region (< 3-4 GeV) are presented.Comment: 7 pages, 9 figure

    First results from the CRESST-III low-mass dark matter program

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    The CRESST experiment is a direct dark matter search which aims to measure interactions of potential dark matter particles in an earth-bound detector. With the current stage, CRESST-III, we focus on a low energy threshold for increased sensitivity towards light dark matter particles. In this manuscript we describe the analysis of one detector operated in the first run of CRESST-III (05/2016-02/2018) achieving a nuclear recoil threshold of 30.1eV. This result was obtained with a 23.6g CaWO4_4 crystal operated as a cryogenic scintillating calorimeter in the CRESST setup at the Laboratori Nazionali del Gran Sasso (LNGS). Both the primary phonon/heat signal and the simultaneously emitted scintillation light, which is absorbed in a separate silicon-on-sapphire light absorber, are measured with highly sensitive transition edge sensors operated at ~15mK. The unique combination of these sensors with the light element oxygen present in our target yields sensitivity to dark matter particle masses as low as 160MeV/c2^2.Comment: 9 pages, 9 figure

    Functional Characterization of a Newly Identified Group B Streptococcus Pullulanase Eliciting Antibodies Able to Prevent Alpha-Glucans Degradation

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    Streptococcal pullulanases have been recently proposed as key components of the metabolic machinery involved in bacterial adaptation to host niches. By sequence analysis of the Group B Streptococcus (GBS) genome we found a novel putative surface exposed protein with pullulanase activity. We named such a protein SAP. The sap gene is highly conserved among GBS strains and homologous genes, such as PulA and SpuA, have been described in other pathogenic streptococci. The SAP protein contains two N-terminal carbohydrate-binding motifs, followed by a catalytic domain and a C-terminal LPXTG cell wall-anchoring domain. In vitro analysis revealed that the recombinant form of SAP is able to degrade α-glucan polysaccharides, such as pullulan, glycogen and starch. Moreover, NMR analysis showed that SAP acts as a type I pullulanase. Studies performed on whole bacteria indicated that the presence of α-glucan polysaccharides in culture medium up-regulated the expression of SAP on bacterial surface as confirmed by FACS analysis and confocal imaging. Deletion of the sap gene resulted in a reduced capacity of bacteria to grow in medium containing pullulan or glycogen, but not glucose or maltose, confirming the pivotal role of SAP in GBS metabolism of α-glucans. As reported for other streptococcal pullulanases, we found specific anti-SAP antibodies in human sera from healthy volunteers. Investigation of the functional role of anti-SAP antibodies revealed that incubation of GBS in the presence of sera from animals immunized with SAP reduced the capacity of the bacterium to degrade pullulan. Of interest, anti-SAP sera, although to a lower extent, also inhibited Group A Streptococcus pullulanase activity. These data open new perspectives on the possibility to use SAP as a potential vaccine component inducing functional cross-reacting antibodies interfering with streptococcal infections

    Probabilistic integration of large Brazilian socioeconomic and clinical databases

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    The integration of disparate large and heterogeneous socioeconomic and clinical databases is considered essential to capture and model longitudinal and social aspects of diseases. However, such integration is challenging: databases are stored in disparate locations, make use of different identifiers, have variable data quality, record information in bespoke purpose-specific formats and have different levels of metadata. Novel computational methods are required to integrate them and enable their statistical analyses for epidemiological research purposes. In this paper, we describe a probabilistic approach for constructing a very large population-based cohort comprised of 114 million individuals using linkages between clinical databases from the National Health System and administrative databases from governmental social programmes. We present our data integration model for creating data marts (epidemiological data) and discuss our evaluation results in controlled and uncontrolled scenarios, which demonstrate that our model and tools achieve high accuracy (minimum of 91%) in different probabilistic data integration scenarios

    Environmental Monitoring Plan, Revision 6

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    The purpose of environmental monitoring is to promote the early identification of, and response to, potential adverse environmental impacts associated with Lawrence Livermore National Laboratory (LLNL) operations. Environmental monitoring supports the Integrated Safety Management System (ISMS), International Organization for Standardization (ISO) 14001 Environmental Management Systems standard, and U. S. Department of Energy (DOE) Order 458.1, Radiation Protection of the Public and the Environment. Specifically, environmental monitoring enables LLNL to detect, characterize, and respond to releases from LLNL activities; assess impacts; estimate dispersal patterns in the environment; characterize the pathways of exposure to members of the public; characterize the exposures and doses to individuals and to the population; and to evaluate the potential impacts to the biota in the vicinity of LLNL. Environmental monitoring is also a major component of compliance demonstration for permits and other regulatory requirements. The Environmental Monitoring Plan (EMP) addresses the sample collection and analytical work supporting environmental monitoring to ensure the following: (1) A consistent system for collecting, assessing, and documenting environmental data of known and documented quality; (2) A validated and consistent approach for sampling and analysis of samples to ensure laboratory data meets program-specific needs and requirements within the framework of a performance-based approach for analytical laboratory work; and (3) An integrated sampling approach to avoid duplicative data collection. LLNL prepares the EMP because it provides an organizational framework for ensuring that environmental monitoring work, which is integral to the implementation of LLNL's Environmental Management System, is conducted appropriately. Furthermore, the Environmental Monitoring Plan helps LLNL ensure compliance with DOE Order 231.1 Change 2, Environment, Safety and Health Reporting, which require the publication of an annual report that characterizes the site's environmental management performance. To summarize, the general regulatory drivers for this environmental monitoring plan are ISO 14001, DOE Order 458.1, and DOE Order 231.1. The environmental monitoring addressed by this plan includes preoperational characterization and assessment, effluent and surveillance monitoring, and permit and regulatory compliance monitoring. Additional environmental monitoring is conducted at LLNL as part of compliance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, also known as Superfund). LLNL coordinates its ground water surveillance monitoring program with the CERCLA monitoring program to gain sampling efficiencies

    BRE modulates granulosa cell death to affect ovarian follicle development and atresia in the mouse

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    The BRE (brain and reproductive expression) gene, highly expressed in nervous and reproductive system organs, plays an important role in modulating DNA damage repair under stress response and pathological conditions. Folliculogenesis, a process that ovarian follicle develops into maturation, is closely associated with the interaction between somatic granulosa cell and oocyte. However, the regulatory role of BRE in follicular development remains undetermined. In this context, we found that BRE is normally expressed in the oocytes and granulosa cells from the primordial follicle stage. There was a reduction in follicles number of BRE mutant (BRE(−/−)) mice. It was attributed to increase the follicular atresia in ovaries, as a result of retarded follicular development. We established that cell proliferation was inhibited, while apoptosis was markedly increased in the granulosa cells in the absence of BRE. In addition, expressions of γ-H2AX (marker for showing DNA double-strand breaks) and DNA damage-relevant genes are both upregulated in BRE(−/−) mice. In sum, these results suggest that the absence of BRE, deficiency in DNA damage repair, causes increased apoptosis in granulosa cells, which in turn induces follicular atresia in BRE(−/−) mice
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