450 research outputs found
Teleoperators for remote operations in space
The primary objective of the remote nuclear teleoperator study program was to define in detail a program plan which would provide a qualified operational space teleoperator system by about 1980. The concept and philosophy presented provides a product considered to be an advanced teleoperator when compared to today's state-of-the-art. The teleoperator concept is formulated to meet NERVA requirements
Prehospital ambulance 12-lead electrocardiograms reduce door to needle time for thrombolysis in the emergency room
Digitalitzat per Artypla
Ultrahigh Bandwidth Spin Noise Spectroscopy: Detection of Large g-Factor Fluctuations in Highly n-Doped GaAs
We advance all optical spin noise spectroscopy (SNS) in semiconductors to
detection bandwidths of several hundred gigahertz by employing an ingenious
scheme of pulse trains from ultrafast laser oscillators as an optical probe.
The ultrafast SNS technique avoids the need for optical pumping and enables
nearly perturbation free measurements of extremely short spin dephasing times.
We employ the technique to highly n-doped bulk GaAs where magnetic field
dependent measurements show unexpected large g-factor fluctuations.
Calculations suggest that such large g-factor fluctuations do not necessarily
result from extrinsic sample variations but are intrinsically present in every
doped semiconductor due to the stochastic nature of the dopant distribution.Comment: 5 pages, 3 figure
Routine HIV Screening in Portugal: Clinical Impact and Cost-Effectiveness
Objective: To compare the clinical outcomes and cost-effectiveness of routine HIV screening in Portugal to the current practice of targeted and on-demand screening. Design: We used Portuguese national clinical and economic data to conduct a model-based assessment. Methods: We compared current HIV detection practices to strategies of increasingly frequent routine HIV screening in Portuguese adults aged 18-69. We considered several subpopulations and geographic regions with varying levels of undetected HIV prevalence and incidence. Baseline inputs for the national case included undiagnosed HIV prevalence 0.16%, annual incidence 0.03%, mean population age 43 years, mean CD4 count at care initiation 292 cells/μL, 63% HIV test acceptance, 78% linkage to care, and HIV rapid test cost €6 under the proposed routine screening program. Outcomes included quality-adjusted survival, secondary HIV transmission, cost, and incremental cost-effectiveness. Results: One-time national HIV screening increased HIV-infected survival from 164.09 quality-adjusted life months (QALMs) to 166.83 QALMs compared to current practice and had an incremental cost-effectiveness ratio (ICER) of €28,000 per quality-adjusted life year (QALY). Screening more frequently in higher-risk groups was cost-effective: for example screening annually in men who have sex with men or screening every three years in regions with higher incidence and prevalence produced ICERs of €21,000/QALY and €34,000/QALY, respectively. Conclusions: One-time HIV screening in the Portuguese national population will increase survival and is cost-effective by international standards. More frequent screening in higher-risk regions and subpopulations is also justified. Given Portugal’s challenging economic priorities, we recommend prioritizing screening in higher-risk populations and geographic settings
Legumes as a Strategy for Reducing Greenhouse Gas Emissions of Forage-Livestock Systems
Incorporation of legumes into forage systems has been a widely adopted strategy to increase pasture productivity and forage nutritive value, while reducing N inputs. Considering the population growth, and the diminishing land resources for food production, the need to increase the food supply will have to be balanced with the environmental impact of these systems, particularly their carbon footprint. Enteric methane production represents the largest source of greenhouse gas emissions from livestock. Certain forage legumes have evolved plant secondary compounds, such as tannins and other polyphenols, which have been associated with reductions in enteric methane emissions. Studies were conducted at Utah State University (USU), and at the University of Florida, North Florida Research and Education Center (UF-NFREC) to assess in vivo methane emissions in grazing cattle, using the SF6 tracer technique. At USU, cattle grazing pastures of Birdsfoot trefoil (Lotus corniculatus; BFT) emitted less methane per unit of dry matter consumed when compared with cattle fed a totally mixed ration (50% barley grain, 25% alfalfa hay, and 25% corn silage) in ad libitum amounts. However, emissions in cattle grazing BFT did not differ from those grazing the legume Cicer milkvetch (Astragalus cicer), or a traditional pasture-finishing system based on Meadow brome (Bromus riparius). At UF-NFREC, three livestock-forage systems were tested during three consecutive years to determine the effects of including the legume Rhizoma peanut (Arachis glabrata Benth.; BHR) in bahiagrass pastures (Paspalum notatum Flügge) fertilized (BH) or not (BHF) with N during the warm season. No differences were observed in methane emissions (g d-1), or in methane emission intensity. From the legumes grazed in these experiments, only BFT contains significant concentrations of tannins. Thus, the potential to mitigate livestock enteric methane emissions by grazing legumes appears to be directly related to the presence of tannins
Nutrient Return from Plant Litter and Cattle Excretion Grazing on N-Fertilized Grass or Grass-Legume Pastures in North Florida
Nutrient recycling via plant litter and livestock excreta is an important ecosystem service provided by grasslands. This study determined nutrient return via these pathways in three grazing systems. The experiment was conducted from May to October (2016 and 2017) and treatments were: 1) Nitrogen fertilized bahiagrass (Paspalum notatum Flügge) pastures (112 kg N ha-1) during the warm-season, overseeded with a mixture (56 kg ha-1 of each) of ‘FL 401’ cereal rye (Secale cereale, L.) and ‘RAM’ oat (Avena sativa, L.) during the cool-season (BGN); 2) Ecoturf Rhizoma peanut (Arachis glabrata Benth.)/bahiagrass pastures during the warm-season, overseeded with similar rye/oat mixture fertilized with 34 kg N ha-1 plus a mixture of clovers (Trifolium incarnatum L., T. pretense L., and T. nigrescens L.) during the cool-season (BGRP); 3) unfertilized bahiagrass pastures during the warm-season, overseeded with similar rye/oat grass/clover mixture + 34 kg N ha-1 during the cool-season (BG). Litter mass was evaluated every 5wk. Litter decomposition was evaluated with incubation periods of 0, 2, 4, 8, 16, 32, 64, 128, and 256 days. Urine and fecal samples were collected for N concentration analysis. There was a net return of 47 kg N ha-1 season-1 via litter in all three systems without differing among them. In addition, litter decomposition rates were not different in the three systems. Conversely, N returned via excreta (urine and feces) was greater (63, 27, and 51 kg N ha-1 season-1) than that returned via litter (58.6, 41.6, and 41.2 kg ha-1 season-1). When assessing the proportions of N returning to the system via litter or excreta, no differences were observed among treatments, and on average 65.1 % of the N returned via excreta vs. 34.9 % returning via litter. The introduction of legumes could reduce the inputs from N fertilizers in grazing systems and keep the productivity similar because of more efficient N cycling
A Smartphone-based Decision Support Tool Improves Test Performance Concerning Application of the Guidelines for Managing Regional Anesthesia in the Patient Receiving Antithrombotic or Thrombolytic Therapy
BACKGROUND: The American Society of Regional Anesthesia and Pain Medicine (ASRA) consensus statement on regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy is the standard for evaluation and management of these patients. The authors hypothesized that an electronic decision support tool (eDST) would improve test performance compared with native physician behavior concerning the application of this guideline.
METHODS: Anesthesiology trainees and faculty at 8 institutions participated in a prospective, randomized trial in which they completed a 20-question test involving clinical scenarios related to the ASRA guidelines. The eDST group completed the test using an iOS app programmed to contain decision logic and content of the ASRA guidelines. The control group completed the test by using any resource in addition to the app. A generalized linear mixed-effects model was used to examine the effect of the intervention.
RESULTS: After obtaining institutional review board's approval and informed consent, 259 participants were enrolled and randomized (eDST = 122; control = 137). The mean score was 92.4 ± 6.6% in the eDST group and 68.0 ± 15.8% in the control group (P < 0.001). eDST use increased the odds of selecting correct answers (7.8; 95% CI, 5.7 to 10.7). Most control group participants (63%) used some cognitive aid during the test, and they scored higher than those who tested from memory alone (76 ± 15% vs. 57 ± 18%, P < 0.001). There was no difference in time to completion of the test (P = 0.15) and no effect of training level (P = 0.56).
CONCLUSIONS: eDST use improved application of the ASRA guidelines compared with the native clinician behavior in a testing environment
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