9 research outputs found
Hadronic Cross-sections in two photon Processes at a Future Linear Collider
In this note we address the issue of measurability of the hadronic
cross-sections at a future photon collider as well as for the two-photon
processes at a future high energy linear collider. We extend, to
higher energy, our previous estimates of the accuracy with which the \gamgam\
cross-section needs to be measured, in order to distinguish between different
theoretical models of energy dependence of the total cross-sections. We show
that the necessary precision to discriminate among these models is indeed
possible at future linear colliders in the Photon Collider option. Further we
note that even in the option a measurement of the hadron production
cross-section via \gamgam processes, with an accuracy necessary to allow
discrimination between different theoretical models, should be possible. We
also comment briefly on the implications of these predictions for hadronic
backgrounds at the future TeV energy collider CLIC.Comment: 20 pages, 5 figures, LaTeX. Added an acknowledgemen
The Electronics and Data Acquisition System of the DarkSide Dark Matter Search
It is generally inferred from astronomical measurements that Dark Matter (DM)
comprises approximately 27\% of the energy-density of the universe. If DM is a
subatomic particle, a possible candidate is a Weakly Interacting Massive
Particle (WIMP), and the DarkSide-50 (DS) experiment is a direct search for
evidence of WIMP-nuclear collisions. DS is located underground at the
Laboratori Nazionali del Gran Sasso (LNGS) in Italy, and consists of three
active, embedded components; an outer water veto (CTF), a liquid scintillator
veto (LSV), and a liquid argon (LAr) time projection chamber (TPC). This paper
describes the data acquisition and electronic systems of the DS detectors,
designed to detect the residual ionization from such collisions
Monitoring of Farm-Level Antimicrobial Use to Guide Stewardship: Overview of Existing Systems and Analysis of Key Components and Processes
peer-reviewedThe acknowledgment of antimicrobial resistance (AMR) as a major health challenge in humans, animals and plants, has led to increased efforts to reduce antimicrobial use (AMU). To better understand factors influencing AMR and implement and evaluate stewardship measures for reducing AMU, it is important to have sufficiently detailed information on the quantity of AMU, preferably at the level of the user (farmer, veterinarian) and/or prescriber or provider (veterinarian, feed mill). Recently, several countries have established or are developing systems for monitoring AMU in animals. The aim of this publication is to provide an overview of known systems for monitoring AMU at farm-level, with a descriptive analysis of their key components and processes. As of March 2020, 38 active farm-level AMU monitoring systems from 16 countries were identified. These systems differ in many ways, including which data are collected, the type of analyses conducted and their respective output. At the same time, they share key components (data collection, analysis, benchmarking, and reporting), resulting in similar challenges to be faced with similar decisions to be made. Suggestions are provided with respect to the different components and important aspects of various data types and methods are discussed. This overview should provide support for establishing or working with such a system and could lead to a better implementation of stewardship actions and a more uniform communication about and understanding of AMU data at farm-level. Harmonization of methods and processes could lead to an improved comparability of outcomes and less confusion when interpreting results across systems. However, it is important to note that the development of systems also depends on specific local needs, resources and aims
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
Liver Match, a prospective observational cohort study on liver transplantation in Italy: study design and current practice of donor-recipient matching
The Liver Match is an observational cohort study that prospectively enrolled liver transplantations performed at 20 out of 21 Italian Transplant Centres between June 2007 and May 2009. Aim of the study is to investigate the impact of donor/recipient matching on outcomes. In this report we describe the study methodology and provide a cross-sectional description of donor and recipient characteristics and of graft allocation
DarkSide-50, a background free experiment for dark matter searches
The existence of dark matter is inferred from gravitational effects, but its nature remains a deep mystery. One possibility, motivated by considerations in elementary particle physics, is that dark matter consists of elementary particles, such as the hypothesized Weakly Interacting Massive Particles (WIMPs), with mass ~ 100 GeV and cross-section ~ 10−47 cm2, that can be gravitationally trapped inside our galaxy and revealed by their scattering on nuclei. It should be possible to detect WIMPs directly, as the orbital motion of the WIMPs composing the dark matter halo pervading the galaxy should result in WIMP-nucleus collisions of sufficient energy to be observable in the laboratory. The DarkSide-50 experiment is a direct WIMP search using a Liquid Argon Time Projection Chamber (LAr-TPC) with an active mass of 50 kg with a high sensitivity and an ultra-low background detector
The Electronics and Data Acquisition System of the DarkSide Dark Matter Search
It is generally inferred from astronomical measurements th
at Dark
Matter (DM) comprises approximately 27% of the energy-dens
ity of the universe.
If DM is a subatomic particle, a possible candidate is a Weakl
y Interacting Mas-
sive Particle (WIMP), and the DarkSide-50 (DS) experiment i
s a direct search for
evidence of WIMP-nuclear collisions. DS is located undergr
ound at the Laboratori
Nazionali del Gran Sasso (LNGS) in Italy, and consists of thr
ee active, embedded
components; an outer water veto (CTF), a liquid scintillato
r veto (LSV), and
a liquid argon (LAr) time projection chamber (TPC). This pap
er describes the
data acquisition and electronic systems of the DS detectors
, designed to detect
the residual ionization from
First Results from the DarkSide-50 Dark Matter Experiment at Laboratori Nazionali del Gran Sasso
We report the first results of DarkSide-50, a direct search for dark matter operating in the un-
derground Laboratori Nazionali del Gran Sasso (LNGS) and searching for the rare nuclear recoils
possibly induced by weakly interacting massive particles (WIMPs). The dark matter detector is a
Liquid Argon Time Projection Chamber with a
(
46.4
0.7
)
kg active mass, operated inside a 30 t or-
ganic liquid scintillator neutron veto, which is in turn installed at the center of a 1 kt water Cherenkov
veto for the residual flux of cosmic rays. We report here the null results of a dark matter search for
a
(
1422
67
)
kg d exposure with an atmospheric argon fill. This is the most sensitive dark matter
search performed with an argon target, corresponding to a 90% CL upper limit on the WIMP-nucleon
spin-independent cross section of 6.1
1