57 research outputs found
Potential Tetany Hazard of N-Fertilized Bromegrass as Indicated by Chemical Composition
The objective of this field experiment was to determine
the effect of N fertilization on yield and chemical composition
of smooth bromegrass (Bromus inermis L.) and
the potential for grass tetany hazard in the northern
Great Plains as indicated by chemical composition of
bromegrass forage. Chemical components of forage considered
in relation to the hazard of tetany (a metabolic
disorder of ruminants resulting from forage with low Mg
availability) were inorganic cations, organic anions, aconitate,
and % total N/% total water-soluble carbohydrate
ratio (N/TWSC). Soil was Parshall fine sandy loam, a
pachic haploborall. Yields and chemical composition of
oven dried forage from plots not previously harvested
were determined at approximately 3-week intervals beginning
May 9. Differences between the sum (in meq/kg)
of inorganic cations (Na+, K+, Ca²+, Mg²+) and inorganic
anions (Cl-, No?-, H?PO?-, SO?²-) in forage was defined
as the concentration of organic anions (C-A).
Mature forage yield obtained from the unfertilized
check plot treatment on July 29 was only 29 and 22%
of yields obtained from plot treatments fertilized with 90
and 270 kg N/ha, respectively. The K/(Ca+Mg) ratios
and K concentrations increased during May and early
June, resulting in a K/(Ca+Mg) ratio near or above 2.2
during June and early June in oven dried forage from
fertilized treatments. Potassium, expressed as a fraction
K/C of the total cations (C), accounted for 35 to 74%
of the cationic charge. Fertilization with N increased total
N and K concentration and K/C in the forage. As K/C
increased, Mg/C and Ca/C decreased and K/(Ca+Mg) increased.
Aconitate and C-A concentration correlated
highly with K concentration and were increased by N
fertilization. Aconitate levels exceeded 1% on May 28;
the 270 kg N-treatment remained above 1% through July.
Nitrogen fertilizer increased N/TWSC in spring-harvested
forage, compared to unfertilized forage, and greatly accentuated
the peak N/TWSC values occurring in late
spring samples.
This study indicated that although potential for increased
forage and livestock-carrying capacity with N
fertilization is tremendous, N-fertilization may result in
a potential tetany hazard to ruminants. Therefore,
management practices are needed which minimize tetany
hazard while bromegrass yields are increased by N fertilization
Nitrogen Efects on Crested Wheatgrass as Related to Forage Quality Indices of Grass Tetany
Nitrogen fertilization of forage is often accompanied by
an increased incidence of grass tetany. A field experiment
was established on two calcareous soils to evaluate
the effects of N fertilizer on forage quality indices of
grass tetany. Nitrogen, as NH?NO?, was applied at 0 and
150 kg N/ha in each of 2 years to separate plots. The
crested wheatgrass [Agropyron desertorum (Fisch.) Schult]
forage was harvested at regular intervals in the Spring
tetany period during 1968 through 1971. Forage was
analyzed for inorganic cations, N, total water-soluble carbohydrates
(TWSC), aconitic acid, higher fatty acids
(HFA), dry matter, and ash alkalinity — a measure of
total organic acids.
Nitrogen fertilizer increased the concentrations (equiv.
basis) of forage Mg and Ca more than the increase in K,
thus slightly reducing the K/(Ca + Mg) values when
compared to the unfertilized forage. However, forage
K/(Ca + Mg) values were usually less than the 2.2 value
above which the incidence of grass tetany increases rapidly.
The potential dietary benefits from the higher Mg
concentrations may have been offset by increased concentrations
of K, N, HFA, N/TWSC, and aconitic acid, since
these parameters are associated with decreased Mg availability
to cattle.
Low values for hypothetical blood serum Mg (calculated
from forage N, Mg, and K concentrations) coincided
with the occurrence of grass tetany in the field. The calculated
serum Mg values were lower in the N-fertilized
forage than in the control.
The aforementioned effects of N fertilization should
not deter the judicious use of N for optimizing forage
yields on semiarid ranges, since other research workers
have found that grass tetany losses can be reduced by
supplementing animals with Mg
Design and construction of the MicroBooNE detector
This paper describes the design and construction of the MicroBooNE liquid
argon time projection chamber and associated systems. MicroBooNE is the first
phase of the Short Baseline Neutrino program, located at Fermilab, and will
utilize the capabilities of liquid argon detectors to examine a rich assortment
of physics topics. In this document details of design specifications, assembly
procedures, and acceptance tests are reported
Volume I. Introduction to DUNE
The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE\u27s physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology
Supernova neutrino detection in NOvA
The NOvA long-baseline neutrino experiment uses a pair of large, segmented, liquid-scintillator calorimeters to study neutrino oscillations, using GeV-scale neutrinos from the Fermilab NuMI beam. These detectors are also sensitive to the flux of neutrinos which are emitted during a core-collapse supernova through inverse beta decay interactions on carbon at energies of O(10 MeV). This signature provides a means to study the dominant mode of energy release for a core-collapse supernova occurring in our galaxy. We describe the data-driven software trigger system developed and employed by the NOvA experiment to identify and record neutrino data from nearby galactic supernovae. This technique has been used by NOvA to self-trigger on potential core-collapse supernovae in our galaxy, with an estimated sensitivity reaching out to 10 kpc distance while achieving a detection efficiency of 23% to 49% for supernovae from progenitor stars with masses of 9.6 M☉ to 27 M☉, respectively
The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set
Background
Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables.
Methods
Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set.
Results
Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001).
Conclusions
The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy
Highly-parallelized simulation of a pixelated LArTPC on a GPU
The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype
The DUNE far detector vertical drift technology. Technical design report
DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals
Deep Underground Neutrino Experiment (DUNE), far detector technical design report, volume III: DUNE far detector technical coordination
The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume III of this TDR describes how the activities required to design, construct, fabricate, install, and commission the DUNE far detector modules are organized and managed. This volume details the organizational structures that will carry out and/or oversee the planned far detector activities safely, successfully, on time, and on budget. It presents overviews of the facilities, supporting infrastructure, and detectors for context, and it outlines the project-related functions and methodologies used by the DUNE technical coordination organization, focusing on the areas of integration engineering, technical reviews, quality assurance and control, and safety oversight. Because of its more advanced stage of development, functional examples presented in this volume focus primarily on the single-phase (SP) detector module
Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF
The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
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