1,077 research outputs found

    Metabolic and cardiovascular adaptation, monkey. NASA SMD 3, project 76, experiment 44 conducted at NASA/JSC, 14-25 May 1977

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    The biomedical results from an experiment on a monkey subjected to space flight conditions are reported. A background history of the development and testing of an experiment system designed to permit measurement of physiological parameters in subhuman primates during continuous, comfortable, couch restraint for periods of up to 30 days is reviewed. Of major importance in the experimental design of the system was the use of a fiberglass pod, which could be sealed and subdivided into upper and lower parts, to monitor and control the physiological responses for various parts of the animal's body. The experiment was conducted within the Spacelab Simulator for a period of 11 days. Data recorded includes: Spacelab Simulator cabin temperature; ventilation rate; pod internal temperature; fraction percent oxygen; fraction percent carbon dioxide; oxygen consumption rate; carbon dioxide production rate; respiratory quotient; intrathoracic temperature; heart rate; mean aortic pressure; mean ventricular pressure; diurnal variation of parameters measured; comparison of mean preflight, flight, and postflight values of the parameters measured; and correlation matrix for the parameters measured

    Impact of Management on Endophyte Free and Endophyte Infected Tall Fescue Cultivars in Ohio

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    Ten cultivars of tall fescue (Festuca arundinacea, Schreb.) and one cultivar of orchardgrass (Dactylis glomerata L.) were part of a study to determine changes in endophyte levels of fescue under two different styles of forage management: intensive and extensive. Included in the study were two endophyte infected-cultivars of tall fescue to compare interactions with endophyte free and infected cultivars. After three years, the results demonstrate that under high levels of management and non-endophyte infected crops prior to seeding, introduction of the endophyte can be reduced or delayed. Under lower levels of management and a smother crop into endophyte infected fescue prior to seeding, high yielding endophyte free cultivars maintain the lowest percent of re-infection (25.0- 32.1% infected)

    Nitrogen Options to Increase Yields for Stockpiling Cool Season Grass in Eastern Ohio, USA

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    Stockpiling cool season grass for grazing in the fall and winter is an option to extend the grazing season. The purpose of this study was to determine the effects of yield and quality by adding urea, urea with Agrotain®, and ammonium sulfate to cool season grasses, primarily fescue and orchardgrass. This was the third year of the three location study in Southeast Ohio. Each location had a randomized complete block design with four treatments (control, 112 kg urea ha-1, 112 kg urea ha-1 plus Agrotain®, and 245.5 kg ammonium sulfate ha-1) and four replications of each treatment. The application date was August 6, 2018 and the plots were harvested on November 4, 2018. There were no statistical differences in crude protein, acid detergent fiber, and total digestible nutrients (CP, ADF, and TDN) (P \u3c 0.05). There were significant differences in yield between the control and all the treatments, but not within the treatments. The three-site average for the control was 2682 kg/ha-1; urea, 3431 kg/ha-1; urea+Agrotain®, 3855 kg/ha-1; and ammonium sulfate, 3468 kg/ha-1. Rainfall in the first 30 days from trial initiation in 2018 ranged from 8.15 to 9.47 cm, and the first significant rainfall (0.28-0.64 cm) was within 30 hours of initiation. This was the third and final year of this study and year three results continue to indicate that adding nitrogen increases yields

    Latent class analysis variable selection

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    We propose a method for selecting variables in latent class analysis, which is the most common model-based clustering method for discrete data. The method assesses a variable's usefulness for clustering by comparing two models, given the clustering variables already selected. In one model the variable contributes information about cluster allocation beyond that contained in the already selected variables, and in the other model it does not. A headlong search algorithm is used to explore the model space and select clustering variables. In simulated datasets we found that the method selected the correct clustering variables, and also led to improvements in classification performance and in accuracy of the choice of the number of classes. In two real datasets, our method discovered the same group structure with fewer variables. In a dataset from the International HapMap Project consisting of 639 single nucleotide polymorphisms (SNPs) from 210 members of different groups, our method discovered the same group structure with a much smaller number of SNP

    Environmental influences predominate in remission from alcohol use disorder in young adult twins

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    Background. Familial influences on remission from alcohol use disorder (AUD) have been studied using family history of AUD rather than family history of remission. The current study used a remission phenotype in a twin sample to examine the relative contributions of genetic and environmental influences to remission

    Optimal simultaneous measurements of incompatible observables of a single photon

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    The ultimate limits of measurement precision are dictated by the laws of quantum mechanics. One of the most fascinating results is that joint or simultaneous measurements of noncommuting quantum observables are possible at the cost of increased unsharpness or measurement uncertainty. Many different criteria exist for determining what an “optimal” joint measurement is, with corresponding different trade-off relations for the measurements. It is generally a nontrivial task to devise or implement a strategy that minimizes the joint-measurement uncertainty. Here, we implement the simplest possible technique for an optimal four-outcome joint measurement and demonstrate a type of optimal measurement that has not been realized before in a photonic setting. We experimentally investigate a joint-measurement uncertainty relation that is more fundamental in the sense that it refers only to probabilities and is independent of values assigned to measurement outcomes. Using a heralded single-photon source, we demonstrate quantum-limited performance of the scheme on single quanta. Since quantum measurements underpin many concepts in quantum information science, this study is both of fundamental interest and relevant for emerging photonic quantum technologies

    An Automated Method for the Detection and Extraction of HI Self-Absorption in High-Resolution 21cm Line Surveys

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    We describe algorithms that detect 21cm line HI self-absorption (HISA) in large data sets and extract it for analysis. Our search method identifies HISA as spatially and spectrally confined dark HI features that appear as negative residuals after removing larger-scale emission components with a modified CLEAN algorithm. Adjacent HISA volume-pixels (voxels) are grouped into features in (l,b,v) space, and the HI brightness of voxels outside the 3-D feature boundaries is smoothly interpolated to estimate the absorption amplitude and the unabsorbed HI emission brightness. The reliability and completeness of our HISA detection scheme have been tested extensively with model data. We detect most features over a wide range of sizes, linewidths, amplitudes, and background levels, with poor detection only where the absorption brightness temperature amplitude is weak, the absorption scale approaches that of the correlated noise, or the background level is too faint for HISA to be distinguished reliably from emission gaps. False detection rates are very low in all parts of the parameter space except at sizes and amplitudes approaching those of noise fluctuations. Absorption measurement biases introduced by the method are generally small and appear to arise from cases of incomplete HISA detection. This paper is the third in a series examining HISA at high angular resolution. A companion paper (Paper II) uses our HISA search and extraction method to investigate the cold atomic gas distribution in the Canadian Galactic Plane Survey.Comment: 39 pages, including 14 figure pages; to appear in June 10 ApJ, volume 626; figure quality significantly reduced for astro-ph; for full resolution, please see http://www.ras.ucalgary.ca/~gibson/hisa/cgps1_survey

    Attributional style, self-esteem, and celebrity worship

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    Two studies were carried out to investigate the relationship between attributional style (Study 1), self-esteem (Study 2), and different forms of celebrity worship. Entertainment social celebrity worship (the most normal form considered) was unrelated to attributional style or self-esteem; intense personal celebrity worship was related positively to self-esteem but also to a propensity toward stable and globalattributions; and borderline pathological celebrity worship (the most negative form considered) was related to external, stable, and global attributions. These results were independent of whether participants were located in Europe or North America, and are discussed in terms of whether celebrity worship should be regarded as positive or negative and as a unitary concept

    A Neutral Hydrogen Self-Absorption Cloud in the SGPS

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    Using data from the Southern Galactic Plane Survey (SGPS) we analyze an HI self-absorption cloud centered on l = 318.0 deg, b = -0.5 deg, and velocity, v = -1.1 km/s. The cloud was observed with the Australia Telescope Compact Array (ATCA) and the Parkes Radio Telescope, and is at a near kinematic distance of less than 400 pc with derived dimensions of less than 5 x 11 pc. We apply two different methods to find the optical depth and spin temperature. In both methods we find upper limit spin temperatures ranging from 20 K to 25 K and lower limit optical depths ~ 1. We look into the nature of the HI emission and find that 60-70% originates behind the cloud. We analyze a second cloud at the same velocity centered on l = 319 deg and b = 0.4 deg with an upper limit spin temperature of 20 K and a lower limit optical depth of 1.6. The similarities in spin temperature, optical depth, velocity, and spatial location are evidence the clouds are associated, possibly as one large cloud consisting of smaller clumps of gas. We compare HI emission data with 12CO emission and find a physical association of the HI self-absorption cloud with molecular gas.Comment: 33 pages, 17 figures, 5 tables; Accepted for publication in ApJ. A version with higher quality images availabe at http://www.astro.umn.edu/~dkavars/ms.p

    HI Narrow Self-Absorption in Dark Clouds: Correlations with Molecular Gas and Implications for Cloud Evolution and Star Formation

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    We present the results of a comparative study of HI narrow self-absorption (HINSA), OH, 13CO, and C18O in five dark clouds. The HINSA follows the distribution of the emission of the carbon monoxide isotopologues, and has a characteristic size close to that of 13CO. This confirms that the HINSA is produced by cold HI which is well mixed with molecular gas in well-shielded regions. The ratio of the atomic hydrogen density to total proton density for these sources is 5 to 27 x 10^{-4}. Using cloud temperatures and the density of HI, we set an upper limit to the cosmic ray ionization rate of 10^{-16} s^{-1}. Comparison of observed and modeled fractional HI abundances indicates ages for these clouds to be 10^{6.5} to 10^{7} yr. The low values of the HI density we have determined make it certain that the time scale for evolution from an atomic to an almost entirely molecular phase, must be a minimum of several million years. This clearly sets a lower limit to the overall time scale for star formation and the lifetime of molecular clouds
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