We report on a search for particle dark matter with the XENON100 experiment, operated at the Laboratori Nazionali del Gran Sasso for 13 months during 2011 and 2012. XENON100 features an ultralow ...electromagnetic background of (5.3 ± 0.6) × 10(-3) events/(keV(ee) × kg × day) in the energy region of interest. A blind analysis of 224.6 live days × 34 kg exposure has yielded no evidence for dark matter interactions. The two candidate events observed in the predefined nuclear recoil energy range of 6.6-30.5 keV(nr) are consistent with the background expectation of (1.0 ± 0.2) events. A profile likelihood analysis using a 6.6-43.3 keV(nr) energy range sets the most stringent limit on the spin-independent elastic weakly interacting massive particle-nucleon scattering cross section for weakly interacting massive particle masses above 8 GeV/c(2), with a minimum of 2 × 10(-45) cm(2) at 55 GeV/c(2) and 90% confidence level.
We present new experimental constraints on the elastic, spin-dependent WIMP-nucleon cross section using recent data from the XENON100 experiment, operated in the Laboratori Nazionali del Gran Sasso ...in Italy. An analysis of 224.6 live days×34 kg of exposure acquired during 2011 and 2012 revealed no excess signal due to axial-vector WIMP interactions with 129Xe and 131Xe nuclei. This leads to the most stringent upper limits on WIMP-neutron cross sections for WIMP masses above 6 GeV/c², with a minimum cross section of 3.5×10(-40) cm² at a WIMP mass of 45 GeV/c², at 90% confidence level.
We present the achievements of the last years of the experimental and theoretical groups working on hadronic cross section measurements at the low-energy
e
+
e
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colliders in Beijing, Frascati, ...Ithaca, Novosibirsk, Stanford and Tsukuba and on
τ
decays. We sketch the prospects in these fields for the years to come. We emphasise the status and the precision of the Monte Carlo generators used to analyse the hadronic cross section measurements obtained as well with energy scans as with radiative return, to determine luminosities and
τ
decays. The radiative corrections fully or approximately implemented in the various codes and the contribution of the vacuum polarisation are discussed.
We present systematic case studies to investigate the sensitivity of axion searches by liquid xenon detectors, using the axio-electric effect (analogue of the photoelectric effect) on xenon atoms. ...Liquid xenon is widely considered to be one of the best target media for detection of WIMPs (Weakly Interacting Massive Particles which may form the galactic dark matter) using nuclear recoils. Since these detectors also provide an extremely low radioactivity environment for electron recoils, very weakly-interacting low-mass particles (< 100keV/c2), such as the hypothetical axion, could be detected as well – in this case using the axio-electric effect. Future ton-scale liquid Xe detectors will be limited in sensitivity only by irreducible neutrino background (pp-chain solar neutrino and the double beta decay of 136Xe) in the mass range between 1 and 100keV/c2. Assuming one ton-year of exposure, galactic axions (as non-relativistic dark matter) could be detected if the axio-electric coupling gAe is greater than 10−14 at 1keV/c2 axion mass (or 10−13 at 100keV/c2). Below a few keV/c2, and independent of the mass, a solar axion search would be sensitive to a coupling gAe∼10-12. This limit will set a stringent upper bound on axion mass for the DFSZ and KSVZ models for the mass ranges mA<0.1 eV/c2 and <10eV/c2, respectively. Vector-boson dark matter could also be detected for a coupling constant α′/α>10-33 (for mass 1keV/c2) or >10-27 (for mass 100keV/c2).
Aims. Since the CGRO operation in 1991–2000, one of the primary unresolved questions about the blazar γ-ray emission has been its possible correlation with the low-energy (in particular optical) ...emission. To help answer this problem, the Whole Earth Blazar Telescope (WEBT) consortium has organized the GLAST-AGILE Support Program (GASP) to provide the optical-to-radio monitoring data to be compared with the γ-ray detections by the AGILE and GLAST satellites. This new WEBT project started in early September 2007, just before a strong γ-ray detection of 0716+714 by AGILE. Methods. We present the GASP-WEBT optical and radio light curves of this blazar obtained in July–November 2007, about various AGILE pointings at the source. We construct NIR-to-UV spectral energy distributions (SEDs), by assembling GASP-WEBT data together with UV data from the Swift ToO observations of late October. Results. We observe a contemporaneous optical-radio outburst, which is a rare and interesting phenomenon in blazars. The shape of the SEDs during the outburst appears peculiarly wavy because of an optical excess and a UV drop-and-rise. The optical light curve is well sampled during the AGILE pointings, showing prominent and sharp flares. A future cross-correlation analysis of the optical and AGILE data will shed light on the expected relationship between these flares and the γ-ray events.
Bone marrow-derived stem cells (BMDSCs) play an essential role in organ repair and regeneration. The molecular mechanisms by which hormones control BMDSCs proliferation and differentiation are ...unclear. Our aim in this study was to investigate how a lack of ovarian or/and thyroid hormones affects stem cell number in bone marrow lineage. To examine the effect of thyroid or/and ovarian hormones on the proliferative activity of BMDSCs, we removed the thyroid or/and the ovaries of adult female rats. An absence of ovarian and thyroid hormones was confirmed by Pap staining and Thyroid Stimulating Hormone (TSH) measurement, respectively. To obtain the stem cells from the bone marrow, we punctured the iliac crest, and aspirated and isolated cells by using a density gradient. Specific markers were used by cytometry to identify the different BMDSCs types: endothelial progenitor cells (EPCs), precursor B cells/pro-B cells, and mesenchymal stem cells (MSCs). Interestingly, our results showed that hypothyroidism caused a significant increase in the percentage of EPCs, whereas a lack of ovarian hormones significantly increased the precursor B cells/pro-B cells. Moreover, the removal of both glands led to increased MSCs. In conclusion, both ovarian and thyroid hormones appear to have key and diverse roles in regulating the proliferation of cells populations of the bone marrow.
Results from the nuclear recoil calibration of the XENON100 dark matter detector installed underground at the Laboratori Nazionali del Gran Sasso, Italy are presented. Data from measurements with an ...external AmB super(241)e neutron source are compared with a detailed Monte Carlo simulation which is used to extract the energy-dependent charge-yield I sub(y) and relative scintillation efficiency Lagrangian (script capital L) sub(eff). A very good level of absolute spectral matching is achieved in both observable signal channels-scintillation S1 and ionization S2-along with agreement in the two-dimensional particle discrimination space. The results confirm the validity of the derived signal acceptance in earlier reported dark matter searches of the XENON100 experiment.
To satisfy the requirements of the next generation of dark matter detectors based on the dual phase TPC, Hamamatsu, in close collaboration with UCLA, has developed the R11410-10 photomultiplier tube. ...In this work, we present the detailed tests performed on this device. High QE (∼30%) accompanied by a low dark count rate (50Hz at 0.3 PE) and high gain (1×107) with good single PE resolution have been observed. A comprehensive screening measurement campaign is ongoing while the manufacturer quotes a radioactivity of 20mBq/PMT. These characteristics show the R11410-10 to be particularly suitable for the forthcoming zero background liquid xenon detectors.
► Requirements needed of PMTs for dark matter searches. ► Systematic tests of 3-in. Hamamatsu R11410-PMT for dark matter detectors. ► Results show high quantum efficiency, low radioactivity, and low noise properties. ► PMT demonstrates suitable qualities necessary for rare event searches.
Flow cytometry has become an increasingly important tool in the clinical laboratory for the diagnosis and monitoring of many hematopoietic neoplasms. This method is ideal for immunophenotypic ...identification of cellular subpopulations in complex samples, such as bone marrow and peripheral blood. In general, 4-color panels appear to be adequate, depending on the assay. In acute leukemias (ALs), it is necessary identify and characterize the population of abnormal cells in order to recognize the compromised lineage and classify leukemia according to the WHO criteria. Although the use of eight- to ten-color immunophenotyping panels is wellestablished, many laboratories do not have access to this technology.
In 2015, the Brazilian Group of Flow Cytometry (Grupo Brasileiro de Citometria de Fluxo, GBCFLUX) proposed antibody panels designed to allow the precise diagnosis and characterization of AL within available resources. As many Brazilian flow cytometry laboratories use four-color immunophenotyping, the GBCFLUX has updated that document, according to current leukemia knowledge and after a forum of discussion and validation of antibody panels.
Recommendations for morphological analysis of bone marrow smears and performing screening panel for lineage (s) identification of AL were maintained from the previous publication. The lineage-oriented proposed panels for B and T cell acute lymphoblastic leukemia (ALL) and for acute myeloid leukemia (AML) were constructed for an appropriate leukemia classification.
Three levels of recommendations (i.e., mandatory, recommended, and optional) were established to enable an accurate diagnosis with some flexibility, considering local laboratory resources and patient-specific needs.
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