260 research outputs found

    Stillbirth differences according to regions of origin: an analysis of the German perinatal database, 2004-2007

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    Reeske A, Kutschmann M, Razum O, Spallek J. Stillbirth differences according to regions of origin: an analysis of the German perinatal database, 2004-2007. BMC Pregnancy and Childbirth. 2011;11(1): 63.Background: Stillbirth is a sensitive indicator for access to, and quality of health care and social services in a society. If a particular population group e. g. migrants experiences higher rates of stillbirth, this might be an indication of social deprivation or barriers to health care. This study examines differences in risk of stillbirth for women of different regions of origin compared to women from Germany in order to identify high risk groups/target groups for prevention strategies. Methods: We used the BQS dataset routinely compiled to examine perinatal outcomes in Germany nationwide. Participation of hospitals and completeness of data has been about 98% in recent years. Data on all live births and stillbirths were obtained for the period 2004 to 2007 (N = 2,670,048). We calculated crude and stratified mortality rates as well as corresponding relative mortality risks. Results: A significantly elevated stillbirth rate was found for women from the Middle East and North Africa (incl. Turkey) (RR 1.34, CI 1.22-1.55). The risk was slightly attenuated for low SES. An elevated risk was also found for women from Asia (RR 1.18, CI 1.02-1.65) and from Mediterranean countries (RR 1.14, CI 0.93-1.28). No considerable differences either in use and timing of antenatal care or preterm birth and low birthweight were observed between migrant and non-migrant women. After stratification for light for gestational age, the relative risk of stillbirth for women from the Middle East/North Africa increased to 1.63 (95% CI 1.25-2.13). When adjusted for preterm births with low birthweight, women from Eastern Europe and the Middle East/North Africa experienced a 26% (43%) higher risk compared with women from Germany. Conclusions: We found differences in risk of stillbirth among women from Middle East/North Africa, especially in association with low SES and low birthweight for gestational age. Our findings suggest a need for developing and evaluating socially and culturally sensitive health promotion and prevention programmes for this group. The findings should also stimulate discussion about the quality and appropriateness of antenatal and perinatal care of pregnant women and newborns with migrant backgrounds

    Law in social work education: reviewing the evidence on teaching, learning and assessment

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    This paper presents the findings from a systemic review of knowledge relating to current practice in the teaching, learning and assessment of law in social work education. The research comprised an internationally conducted systematic review of the literature, together with a survey of current education practice in the four countries of the UK. Two consultation events sought the views of a range of stakeholders, including the perspectives of service users and carers. Set in the context of debates about the relationship between law and social work practice, this paper identifies the common themes emerging from the review and offers an analysis of key findings, together with priorities for future directions in education practice

    Low-energy Calibration of XENON1T with an Internal 37^{37}Ar Source

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    A low-energy electronic recoil calibration of XENON1T, a dual-phase xenontime projection chamber, with an internal 37^{37}Ar source was performed. Thiscalibration source features a 35-day half-life and provides two mono-energeticlines at 2.82 keV and 0.27 keV. The photon yield and electron yield at 2.82 keVare measured to be (32.3±\pm0.3) photons/keV and (40.6±\pm0.5) electrons/keV,respectively, in agreement with other measurements and with NEST predictions.The electron yield at 0.27 keV is also measured and it is(68.0−3.7+6.3^{+6.3}_{-3.7}) electrons/keV. The 37^{37}Ar calibration confirms thatthe detector is well-understood in the energy region close to the detectionthreshold, with the 2.82 keV line reconstructed at (2.83±\pm0.02) keV, whichfurther validates the model used to interpret the low-energy electronic recoilexcess previously reported by XENON1T. The ability to efficiently remove argonwith cryogenic distillation after the calibration proves that 37^{37}Ar can beconsidered as a regular calibration source for multi-tonne xenon detectors.<br

    Effective Field Theory and Inelastic Dark Matter Results from XENON1T

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    In this work, we expand on the XENON1T nuclear recoil searches to study theindividual signals of dark matter interactions from operators up todimension-eight in a Chiral Effective Field Theory (ChEFT) and a model ofinelastic dark matter (iDM). We analyze data from two science runs of theXENON1T detector totaling 1\,tonne×\timesyear exposure. For these analyses, weextended the region of interest from [4.9, 40.9] \,keVNR_{\text{NR}} to [4.9,54.4] \,keVNR_{\text{NR}} to enhance our sensitivity for signals that peak atnonzero energies. We show that the data is consistent with the background-onlyhypothesis, with a small background over-fluctuation observed peaking between20 and 50 \,keVNR_{\text{NR}}, resulting in a maximum local discoverysignificance of 1.7\,σ\sigma for the Vector⊗\otimesVectorstrange_{\text{strange}}(VVsVV_s) ChEFT channel for a dark matter particle of 70 \,GeV/c2^2, and1.8 σ1.8\,\sigma for an iDM particle of 50 \,GeV/c2^2 with a mass splitting of100 \,keV/c2^2. For each model, we report 90\,\% confidence level (CL) upperlimits. We also report upper limits on three benchmark models of dark matterinteraction using ChEFT where we investigate the effect of isospin-breakinginteractions. We observe rate-driven cancellations in regions of theisospin-breaking couplings, leading to up to 6 orders of magnitude weaker upperlimits with respect to the isospin-conserving case.<br

    Low-energy calibration of XENON1T with an internal 37^{{\textbf {37}}}Ar source

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    A low-energy electronic recoil calibration of XENON1T, a dual-phase xenon time projection chamber, with an internal 37Ar source was performed. This calibration source features a 35-day half-life and provides two mono-energetic lines at 2.82 keV and 0.27 keV. The photon yield and electron yield at 2.82 keV are measured to be (32.3±0.3) photons/keV and (40.6±0.5) electrons/keV, respectively, in agreement with other measurements and with NEST predictions. The electron yield at 0.27 keV is also measured and it is (68.0+6.3−3.7) electrons/keV. The 37Ar calibration confirms that the detector is well-understood in the energy region close to the detection threshold, with the 2.82 keV line reconstructed at (2.83±0.02) keV, which further validates the model used to interpret the low-energy electronic recoil excess previously reported by XENON1T. The ability to efficiently remove argon with cryogenic distillation after the calibration proves that 37Ar can be considered as a regular calibration source for multi-tonne xenon detectors

    Emission of single and few electrons in XENON1T and limits on light dark matter

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    Delayed single- and few-electron emissions plague dual-phase time projection chambers, limiting their potential to search for light-mass dark matter. This paper examines the origins of these events in the XENON1T experiment. Characterization of the intensity of delayed electron backgrounds shows that the resulting emissions are correlated, in time and position, with high-energy events and can effectively be vetoed. In this work we extend previous S2-only analyses down to a single electron. From this analysis, after removing the correlated backgrounds, we observe rates <30 events/(electron×kg×day) in the region of interest spanning 1 to 5 electrons. We derive 90% confidence upper limits for dark matter-electron scattering, first direct limits on the electric dipole, magnetic dipole, and anapole interactions, and bosonic dark matter models, where we exclude new parameter space for dark photons and solar dark photons

    Low-energy Calibration of XENON1T with an Internal 37^{37}Ar Source

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    A low-energy electronic recoil calibration of XENON1T, a dual-phase xenon time projection chamber, with an internal 37^{37}Ar source was performed. This calibration source features a 35-day half-life and provides two mono-energetic lines at 2.82 keV and 0.27 keV. The photon yield and electron yield at 2.82 keV are measured to be (32.3±\pm0.3) photons/keV and (40.6±\pm0.5) electrons/keV, respectively, in agreement with other measurements and with NEST predictions. The electron yield at 0.27 keV is also measured and it is (68.0−3.7+6.3^{+6.3}_{-3.7}) electrons/keV. The 37^{37}Ar calibration confirms that the detector is well-understood in the energy region close to the detection threshold, with the 2.82 keV line reconstructed at (2.83±\pm0.02) keV, which further validates the model used to interpret the low-energy electronic recoil excess previously reported by XENON1T. The ability to efficiently remove argon with cryogenic distillation after the calibration proves that 37^{37}Ar can be considered as a regular calibration source for multi-tonne xenon detectors

    Searching for Heavy Dark Matter near the Planck Mass with XENON1T

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    Multiple viable theoretical models predict heavy dark matter particles with a mass close to the Planck mass, a range relatively unexplored by current experimental measurements. We use 219.4 days of data collected with the XENON1T experiment to conduct a blind search for signals from multiply interacting massive particles (MIMPs). Their unique track signature allows a targeted analysis with only 0.05 expected background events from muons. Following unblinding, we observe no signal candidate events. This Letter places strong constraints on spin-independent interactions of dark matter particles with a mass between 1×1012^{12} and 2×1017^{17}  GeV/c2^2. In addition, we present the first exclusion limits on spin-dependent MIMP-neutron and MIMP-proton cross sections for dark matter particles with masses close to the Planck scale

    Double-weak decays of 124^{124}Xe and 136^{136}Xe in the XENON1T and XENONnT experiments

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