We present the results of a search for dark matter weakly interacting massive particles (WIMPs) in the mass range below 20 GeV/c^{2} using a target of low-radioactivity argon with a 6786.0 kg d ...exposure. The data were obtained using the DarkSide-50 apparatus at Laboratori Nazionali del Gran Sasso. The analysis is based on the ionization signal, for which the DarkSide-50 time projection chamber is fully efficient at 0.1 keVee. The observed rate in the detector at 0.5 keVee is about 1.5 event/keVee/kg/d and is almost entirely accounted for by known background sources. We obtain a 90% C.L. exclusion limit above 1.8 GeV/c^{2} for the spin-independent cross section of dark matter WIMPs on nucleons, extending the exclusion region for dark matter below previous limits in the range 1.8-6 GeV/c^{2}.
We present a novel approach for the search of dark matter in the DarkSide-50 experiment, relying on Bayesian Networks. This method incorporates the detector response model into the likelihood ...function, explicitly maintaining the connection with the quantity of interest. No assumptions about the linearity of the problem or the shape of the probability distribution functions are required, and there is no need to morph signal and background spectra as a function of nuisance parameters. By expressing the problem in terms of Bayesian Networks, we have developed an inference algorithm based on a Markov Chain Monte Carlo to calculate the posterior probability. A clever description of the detector response model in terms of parametric matrices allows us to study the impact of systematic variations of any parameter on the final results. Our approach not only provides the desired information on the parameter of interest, but also potential constraints on the response model. Our results are consistent with recent published analyses and further refine the parameters of the detector response model.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The last bending section of a proton therapy beam line may be mounted on a rotating gantry to target the cancerous cells of patients from all possible angles. To gain such capability, it is sensible ...to use superconducting magnets because of their high energy density providing a large reduction in weight. In the following work, a configuration of combined function magnets for rotating gantries is presented. It includes two conventional electromagnets and three superconducting magnets using Nb 3 Sn conduction-cooled at around 4.2 K. For such assembly, an alignment procedure is proposed to ensure that a large beam momentum acceptance can be achieved. Besides this proposal, additional 3D mechanical Finite Element analyses were conducted to check that the structural support of the most critical superconducting magnets made of Nb 3 Sn wires and their coil thermal shields could handle their weight as well as the momentum due to the rotation.
A double-phase argon Time Projection Chamber (TPC), with an active mass of 185 g, has been designed and constructed for the Recoil Directionality (ReD) experiment. The aim of the ReD project is to ...investigate the directional sensitivity of argon-based TPCs via columnar recombination to nuclear recoils in the energy range of interest (20–
200
keV
nr
) for direct dark matter searches. The key novel feature of the ReD TPC is a readout system based on cryogenic Silicon Photomultipliers (SiPMs), which are employed and operated continuously for the first time in an argon TPC. Over the course of 6 months, the ReD TPC was commissioned and characterised under various operating conditions using
γ
-ray and neutron sources, demonstrating remarkable stability of the optical sensors and reproducibility of the results. The scintillation gain and ionisation amplification of the TPC were measured to be
g
1
=
(
0.194
±
0.013
)
photoelectrons/photon and
g
2
=
(
20.0
±
0.9
)
photoelectrons/electron, respectively. The ratio of the ionisation to scintillation signals (S2/S1), instrumental for the positive identification of a candidate directional signal induced by WIMPs, has been investigated for both nuclear and electron recoils. At a drift field of 183 V/cm, an S2/S1 dispersion of 12% was measured for nuclear recoils of approximately 60–
90
keV
nr
, as compared to 18% for electron recoils depositing 60 keV of energy. The detector performance reported here meets the requirements needed to achieve the principal scientific goals of the ReD experiment in the search for a directional effect due to columnar recombination. A phenomenological parameterisation of the recombination probability in LAr is presented and employed for modeling the dependence of scintillation quenching and charge yield on the drift field for electron recoils between 50–500 keV and fields up to 1000 V/cm.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This textbook provides a comprehensive review of all the common and less often encountered pediatric and adolescent gynecology problems in daily practice, both in the ambulatory as well as in the ...surgical setting. This new edition has been updated to keep it closely aligned to what general gynecologists or family physicians will want to know when dealing with a paediatric or adolescent patient, with accompanying videos.
Joseph S Sanfilippo, MD, MBA : Professor, Department of Obstetrics, Gynecology & Reproductive Sciences, and Academic Division Director, Reproductive Endocrinology and Infertility, Magee-Womens Hospital of UPMC, University of Pittsburgh Medical Center, Pittsburgh, Philadelphia, USA
Eduardo Lara-Torre, MD, FACOG: Vice Chair for Academic Affairs and Section Chief, Academic Specialists in General Obstetrics & Gynecology, Carilion Clinic; Professor, Department of Obstetrics & Gynecology and Pediatrics, Virginia Tech-Carilion School of Medicine, Roanoke, Virginia, USA
Veronica Gomez-Lobo, MD: Director of Pediatric and Adolescent Obstetrics & Gynecology, MedStar Washington Hospital Center/Children’s National; Professor of Obstetrics & Gynecology, Georgetown University, Washington, DC, USA
Normal pubertal development and the menstrual cycle as a vital sign. Communication strategies with the adolescent patient. The physical exam in the pediatric and adolescent patient. Adolescent sexual development and sexuality education. Pubertal abnormalities: Precocious and delayed. Congenital anomalies of the reproductive tract. Variation of sex differentiation. Common vulvar and vaginal complaints. Genital injuries in children and adolescents. Basic dermatology in children and adolescents. Pediatric urology. Adnexal masses in the neonate, child, and adolescent. Breast disorders in children and adolescents. Menstrual disorders and blood dyscrasias in adolescents. Polycystic ovary syndrome and hyperandrogenism in adolescents. Adolescent contraception. Sexually transmitted infections in adolescents. Chronic pelvic pain and endometriosis. Perioperative care of the pediatric and adolescent gynecology patient. Adolescent pregnancy. Nutrition and eating disorders. Reproductive effects of obesity in adolescents. Transgender care in adolescents. Reproductive health care for adolescents with developmental delay. Sexual abuse. Fertility preservation in pediatric and adolescent girls. Confidential care issues. Family and cultural factors in pediatric gynecology. Health-care transition. Legal considerations in pediatric and adolescent obstetrics and gynecology. Appendix 1: Additional video resources. Appendix 2: Establishing a pediatric and adolescent gynecology clinical and educational program. Index.
Abstract Introduction We have previously shown that miRNAs produced from the Chromosome 19 MiRNA Cluster (C19MC), which are expressed almost exclusively in primate trophoblasts and are released into ...the maternal circulation, reduce viral replication in non-placental cells and can modulate migratory behavior of extravillous trophoblast. We sought to define the expression pattern of C19MC miRNA in early pregnancy and in response to viral infection in vitro and in vivo. Methods We prospectively followed women undergoing in vitro fertilization (IVF) and determined their blood level of C19MC miRNA using RT-qPCR. To examine the effect of viral exposure on C19MC miRNAs expression, we used three systems: (1) a transgenic mouse overexpressing the C19MC cluster and exposed to Togaviridae during pregnancy, (2) cultured primary human trophoblasts exposed to Vesicular Stomatitis Virus in vitro , and (3) amniotic fluid from women exposed to cytomegalovirus during pregnancy. Results In 27 IVF pregnancies, C19MC miRNAs were detected as early as 2 weeks after implantation, and their levels increased thereafter. There was no change in C19MC miRNA expression levels in the mouse placenta in response to viral exposure. Similarly, Vesicular Stomatitis Virus infection of primary human trophoblast did not selectively increase C19MC miRNA expression. C19MC miRNA expression in the amniotic fluid was not affected by vertical transmission of cytomegalovirus. Discussion The expression of C19MC miRNAs in maternal circulation very early in pregnancy suggests a role in the establishment of the maternal-fetal interface. The levels of C19MC miRNA are not influenced by diverse types of viral infection.
We report on the performance of commercial SiPM-based photo-detector Multi-Pixel Photon Counter (MPPC) S13360-6075CS by Hamamatsu Photonics from room temperature down to -50 °C at INFN - Sezione di ...Roma Tre. The work presented here is focused on the realization of 10 m
2
SiPM surface for the Taishan Antineutrino Observatory (TAO) near detector in the framework of the Jiangmen Underground Neutrino Observatory (JUNO) neutrino experiment.
In this work we present a low noise high speed readout electronics for large area Silicon Photomultipiers (SiPMs) to be used in a cryogenic environment. The board is able to manage the signals coming ...from a 25 cm
2
SiPM tile, showing ¡10% SPE resolution and wide dynamic. The sub-nanosecond timing properties make them suitable to work with the typical mixtures of Liquid Scintillators currently being used in particle and astroparticle physics experiments. The boards have been tested with several types of SiPMs from room temperature down to -70 C showing excellent single photo-electron resolution in all the enviroments. The board’s PCBs have been developed with ultra low background material in order to be used in rare event searches.
A Geant4-based Monte Carlo package named G4DS has been developed to simulate the response of DarkSide-50, an experiment operating since 2013 at LNGS, designed to detect WIMP interactions in liquid ...argon. In the process of WIMP searches, DarkSide-50 has achieved two fundamental milestones: the rejection of electron recoil background with a power of ∼107, using the pulse shape discrimination technique, and the measurement of the residual 39Ar contamination in underground argon, ∼3 orders of magnitude lower with respect to atmospheric argon. These results rely on the accurate simulation of the detector response to the liquid argon scintillation, its ionization, and electron-ion recombination processes. This work provides a complete overview of the DarkSide Monte Carlo and of its performance, with a particular focus on PARIS, the custom-made liquid argon response model.
In this article, we attempt to summarize the 5-year long involvement of PSI through the CHART MagDev program with R&D on the Canted Cosine Theta (CCT) technology as a candidate for an FCC-hh main ...dipole magnet. We present the test results of the Canted Dipole 1 (CD1) 1-m-long 10-T Nb<inline-formula><tex-math notation="LaTeX">_{3}</tex-math></inline-formula>Sn demonstrator magnet, as well as a subjective list of 'pros and cons' of CCT for the FCC-hh that we compiled along the way. By sharing our conclusions, we hope to contribute to an ongoing discussion, while maintaining our utmost respect to the community of CCT developers. The presented findings and conclusions are not final, and we remain open to arguments and discussions, as well as technical exchanges on the topic.
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