124 research outputs found
Psychologische Prädiktoren für das Auftreten einer Major Depression und einer PTBS nach schweren Unfällen
Theoretischer Hintergrund/Fragestellung: Ziel unserer prospektiven Studie war die Identifikation von Prädiktoren für das Auftreten einer Depression im ersten halben Jahr nach einem Unfall.
Methode: Es wurden 52 Unfallpatienten untersucht. Die Ersterhebung erfolgte innerhalb der ersten sechs Wochen nach dem Unfall.
Ergebnisse: Depressive Patienten gaben kurz nach dem Unfall eine geringere Lebenszufriedenheit und soziale Unterstützung an und berichteten häufiger über psychische Störungen und traumatische Erlebnisse vor dem Unfall als Nicht-Depressive. Außerdem litten sie zum Zeitpunkt der Ersterhebung häufiger unter psychischen Störungen und fühlten sich durch die psychischen Symptome stärker beeinträchtigt.
Schlussfolgerung: Die Ergebnisse legen nahe, dass Patienten mit einem Risiko für die Entwicklung einer Depression bereits kurz nach einem Unfall identifiziert werden können
Water Intake in Growing Beef Cattle
Water is an essential part of livestock and human diets and is often thought of as an inexpensive, readily available renewable natural resource. However, the amount of competition between humans, wildlife, feed production, and livestock for high-quality water is increasing, not only from the effects of drought but from the pressure of a growing global population (Nardone et al., 2010). With limited resources available for production agriculture, there is a need to identify and select for efficient animals that can produce more product with fewer inputs. Although some work has been done in dairy cattle, very little data is available on individual animal water intake in modern beef cattle (Brew et al., 2011). The majority of the water intake data available in growing beef cattle is derived from dividing the total amount of water drunk in a pen divided by the number of animals in that pen (Sexson et al., 2010; Mader and Davis, 2004). Data derived from groups are not generally useful for the purposes of genetic evaluation, which aims to quantify individual animal variation in a trait for selection. However, in order to practice selection on a large scale, parameters for collecting phenotypic data must be established. The objectives of this study were to measure daily water intake on a large number of beef steers and to estimate the number of test days necessary to collect accurate water intake phenotypes
Resonant Enhancement of Inelastic Light Scattering in the Fractional Quantum Hall Regime at
Strong resonant enhancements of inelastic light scattering from the long
wavelength inter-Landau level magnetoplasmon and the intra-Landau level spin
wave excitations are seen for the fractional quantum Hall state at .
The energies of the sharp peaks (FWHM ) in the profiles of
resonant enhancement of inelastic light scattering intensities coincide with
the energies of photoluminescence bands assigned to negatively charged exciton
recombination. To interpret the observed enhancement profiles, we propose
three-step light scattering mechanisms in which the intermediate resonant
transitions are to states with charged excitonic excitations.Comment: 5 pages, 5 figure
Shake-up Processes in a Low-Density Two-Dimensional Electron Gas: Spin-Dependent Transitions to Higher Hole Landau Levels
A theory of shake-up processes in photoabsorption of an interacting
low-density two-dimensional electron gas (2DEG) in strong magnetic fields is
presented. In these processes, an incident photon creates an electron-hole pair
and, because of Coulomb interactions, simultaneously excites one particle to
higher Landau levels (LL's). In this work, the spectra of correlated charged
spin-singlet and spin-triplet electron-hole states in the first hole LL and
optical transitions to these states (i.e., shake-ups to the first hole LL) are
studied. Our results indicate, in particular, the presence of optically-active
three-particle quasi-discrete states in the exciton continuum that may give
rise to surprisingly sharp Fano resonances in strong magnetic fields. The
relation between shake-ups in photoabsorption of the 2DEG and in the 2D hole
gas (2DHG), and shake-ups of isolated negative X^- and positive X^+ trions are
discussed.Comment: 8 pages, 8 figures. References updated, one figure added (Fig. 6).
Accepted in Phys. Rev.
Environmental effects on water intake and water intake prediction in growing beef cattle
Water is an essential nutrient, but there are few recent studies that evaluate how much water individual beef cattle consume and how environmental factors affect an individual’s water intake (WI). Most studies have focused on WI of whole pens rather than WI of individual animals. Thus, the objective of this study was to evaluate the impact of environmental parameters on individual-animal WI across different seasons and develop prediction equations to estimate WI, including within different environments and management protocols. Individual daily feed intake and WI records were collected on 579 crossbred steers for a 70-d period following a 21-d acclimation period for feed and water bunk training. Steers were fed in 5 separate groups over a 3-yr period from May 2014 to March 2017. Individual weights were collected every 14 d and weather data were retrieved from the Oklahoma Mesonet’s Stillwater station. Differences in WI as a percent of body weight (WI%) were analyzed accounting for average temperature (TAVG), relative humidity (HAVG), solar radiation (SRAD), and wind speed (WSPD). Seasonal (summer vs. winter) and management differences (ad libitum vs. slick bunk) were examined. Regression analysis was utilized to generate 5 WI prediction equations (overall, summer, winter, slick, and ad libitum). There were significant (P \u3c 0.05) differences in WI between all groups when no environmental parameters were included in the model. Although performance was more similar after accounting for all differences in weather variables, significant (P \u3c 0.05) seasonal and feed management differences were still observed for WI%, but were less than 0.75% of steer body weight. The best linear predictors of daily WI (DWI) were dry mater intake (DMI), metabolic body weights (MWTS), TAVG, SRAD, HAVG, and WSPD. Slight differences in the coefficient of determinations for the various models were observed for the summer (0.34), winter (0.39), ad libitum (0.385), slick bunk (0.41), and overall models (0.40). Based on the moderate R2 values for the WI prediction equations, individual DWI can be predicted with reasonable accuracy based on the environmental conditions that are present, MWTS, and DMI consumed, but substantial variation exists in individual animal WI that is not accounted for by these models
Trionic Optical Potential for Electrons in Semiconductors
Laser-induced optical potentials for atoms have led to remarkable advances in
precision measurement, quantum information, and towards addressing fundamental
questions in condensed matter physics. Here, we describe analogous optical
potentials for electrons in quantum wells and wires that can be generated by
optically driving the transition between a single electron and a three-body
electron-exciton bound state, known as a trion. The existence of a bound trion
state adds a term to the ac Stark shift of the material proportional to the
light intensity at the position of the electron. According to our theoretical
calculations, this shift can be large relative to the thermal equilibrium
temperature of the electron, resulting in a relatively strong optical potential
that could be used to trap, guide, and manipulate individual electrons within a
semiconductor quantum well or wire. These potentials can be thought of as
artificial nano-structures on the scale of 100 nm that can be spin-dependent
and reconfigurable in real-time. Our results suggest the possibility of
integrating ultrafast optics and gate voltages in new resolved-carrier
semiconductor opto-electronic devices, with potential applications in fields
such as nano-electronics, spintronics, and quantum information processingComment: Article and Supplemental Materials; This is a preprint of the
original submission to Nature Physic
A Robust Ensemble Algorithm for Ischemic Stroke Lesion Segmentation: Generalizability and Clinical Utility Beyond the ISLES Challenge
Diffusion-weighted MRI (DWI) is essential for stroke diagnosis, treatment
decisions, and prognosis. However, image and disease variability hinder the
development of generalizable AI algorithms with clinical value. We address this
gap by presenting a novel ensemble algorithm derived from the 2022 Ischemic
Stroke Lesion Segmentation (ISLES) challenge. ISLES'22 provided 400 patient
scans with ischemic stroke from various medical centers, facilitating the
development of a wide range of cutting-edge segmentation algorithms by the
research community. Through collaboration with leading teams, we combined
top-performing algorithms into an ensemble model that overcomes the limitations
of individual solutions. Our ensemble model achieved superior ischemic lesion
detection and segmentation accuracy on our internal test set compared to
individual algorithms. This accuracy generalized well across diverse image and
disease variables. Furthermore, the model excelled in extracting clinical
biomarkers. Notably, in a Turing-like test, neuroradiologists consistently
preferred the algorithm's segmentations over manual expert efforts,
highlighting increased comprehensiveness and precision. Validation using a
real-world external dataset (N=1686) confirmed the model's generalizability.
The algorithm's outputs also demonstrated strong correlations with clinical
scores (admission NIHSS and 90-day mRS) on par with or exceeding expert-derived
results, underlining its clinical relevance. This study offers two key
findings. First, we present an ensemble algorithm
(https://github.com/Tabrisrei/ISLES22_Ensemble) that detects and segments
ischemic stroke lesions on DWI across diverse scenarios on par with expert
(neuro)radiologists. Second, we show the potential for biomedical challenge
outputs to extend beyond the challenge's initial objectives, demonstrating
their real-world clinical applicability
Penumbral Rescue by normobaric O = O administration in patients with ischemic stroke and target mismatch proFile (PROOF): Study protocol of a phase IIb trial.
Oxygen is essential for cellular energy metabolism. Neurons are particularly vulnerable to hypoxia. Increasing oxygen supply shortly after stroke onset could preserve the ischemic penumbra until revascularization occurs.
PROOF investigates the use of normobaric oxygen (NBO) therapy within 6 h of symptom onset/notice for brain-protective bridging until endovascular revascularization of acute intracranial anterior-circulation occlusion.
Randomized (1:1), standard treatment-controlled, open-label, blinded endpoint, multicenter adaptive phase IIb trial.
Primary outcome is ischemic core growth (mL) from baseline to 24 h (intention-to-treat analysis). Secondary efficacy outcomes include change in NIHSS from baseline to 24 h, mRS at 90 days, cognitive and emotional function, and quality of life. Safety outcomes include mortality, intracranial hemorrhage, and respiratory failure. Exploratory analyses of imaging and blood biomarkers will be conducted.
Using an adaptive design with interim analysis at 80 patients per arm, up to 456 participants (228 per arm) would be needed for 80% power (one-sided alpha 0.05) to detect a mean reduction of ischemic core growth by 6.68 mL, assuming 21.4 mL standard deviation.
By enrolling endovascular thrombectomy candidates in an early time window, the trial replicates insights from preclinical studies in which NBO showed beneficial effects, namely early initiation of near 100% inspired oxygen during short temporary ischemia. Primary outcome assessment at 24 h on follow-up imaging reduces variability due to withdrawal of care and early clinical confounders such as delayed extubation and aspiration pneumonia.
ClinicalTrials.gov: NCT03500939; EudraCT: 2017-001355-31
Does diet affect breast cancer risk?
The role of specific dietary factors in breast cancer causation is not completely resolved. Results from prospective studies do not support the concept that fat intake in middle life has a major relation to breast cancer risk. However, weight gain in middle life contributes substantially to breast cancer risk. Alcohol is the best established dietary risk factor, probably by increasing endogenous estrogen levels. Hypotheses relating diet during youth to risk decades later will be difficult to test. Nevertheless, available evidence is strong that breast cancer risk can be reduced by avoiding weight gain during adult years, and by limiting alcohol consumption
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