1,349 research outputs found

    Oxygen-induced regulation of the intracellular glutathione levels in erythrocytes

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    How should the respiration rate be counted in cattle?

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    Respiration rate (RR) is a proficient indicator to measure the health status of cattle. The common method of measurement is to count the number of respiratory cycles each minute based on flank movements. However, there is no consistent method of execution. In previous studies, various methods have been described, including counting flank movements for 15 s, 30 s or 60 s as well as stopping the time for 5 or 10 breaths. We assume that the accuracy of the aforementioned methods differs. Therefore, we compared their precision with an RR sensor, which was used as the reference method in this study. Five scientists from the fields of agricultural science and veterinary medicine quantified the flank movement according to each of the five methods mentioned above. The results showed that with an average RR of 30 breaths per minute (bpm), all methods showed a high correlation to the values of the RR sensor. However, counting breaths for 60 s had the highest level of conformity with the RR sensor (Lin`s concordance correlation coefficient: 0.96) regardless of the level of RR. With rising RR, the inaccuracy increased significantly for the other four investigated methods, especially when counting 5 and 10 breaths. Therefore, we would recommend that counting for 60 s should be used as the standard method for future studies due to its high precision regardless of the level of RR

    Time resolved fission in metal clusters

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    We explore from a theoretical point of view pump and probe (P&P) analysis for fission of metal clusters where probe pulses are generalized to allow for scanning various frequencies. We show that it is possible to measure the time the system needs to develop to scission. This is achieved by a proper choice of both delay and frequency of the probe pulse. A more detailed analysis even allows to access the various intermediate stages of the fission process.Comment: 4 pages, 4 figure

    Einstein-aether theory, violation of Lorentz invariance, and metric-affine gravity

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    We show that the Einstein-aether theory of Jacobson and Mattingly (J&M) can be understood in the framework of the metric-affine (gauge theory of) gravity (MAG). We achieve this by relating the aether vector field of J&M to certain post-Riemannian nonmetricity pieces contained in an independent linear connection of spacetime. Then, for the aether, a corresponding geometrical curvature-square Lagrangian with a massive piece can be formulated straightforwardly. We find an exact spherically symmetric solution of our model.Comment: Revtex4, 38 pages, 1 figur

    Rotating Black Holes in Metric-Affine Gravity

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    Within the framework of metric-affine gravity (MAG, metric and an independent linear connection constitute spacetime), we find, for a specific gravitational Lagrangian and by using {\it prolongation} techniques, a stationary axially symmetric exact solution of the vacuum field equations. This black hole solution embodies a Kerr-deSitter metric and the post-Riemannian structures of torsion and nonmetricity. The solution is characterized by mass, angular momentum, and shear charge, the latter of which is a measure for violating Lorentz invariance.Comment: 32 pages latex, 3 table

    Synthesis and properties of zwitterionic phosphonioglycolates

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    Reaction of diphenylphosphane with glyoxylic acid hydrate in diethyl ether furnished diphenylphosphanylglycolic acid 1 and in a 1:2 molar ratio almost quantitatively the zwitterionic phosphonioglycolic acid glycolate 2. Tertiary phosphanes with aryl or alkyl groups (phenyl, m/p-tolyl, p-anisyl, n-butyl, tert-butyl) react similarly to triorganylphosphonioglycolates 3a-h, which like 2 precipitate from the etheral solutions of the reactants. Tri-n- butylphosphonioglycolate (3e) forms an ionic liquid and tri-tert- butylphosphonioglycolate (3f) a viscous product whereas the other phosphonioglycolates are solids. Yields and stabilities of 3a-e increase with the P-basicity of the starting phosphane whereas bulky groups like tert-butyl cause destabilization. Compound 2 is the most stable phosphonioglycolate with only minor amounts of 1 in the solvolysis equilibrium in D2O. The triaryl and tributylphosphonioglycolates 3a-f decompose in protic solvents with recovery of tertiary phosphanes. On heating at 100 C the compounds decompose to the corresponding phosphine oxides, minor amounts of glycolic acid and unidentified products. © 2013 Elsevier Ltd. All rights reserved

    The Cotton tensor in Riemannian spacetimes

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    Recently, the study of three-dimensional spaces is becoming of great interest. In these dimensions the Cotton tensor is prominent as the substitute for the Weyl tensor. It is conformally invariant and its vanishing is equivalent to conformal flatness. However, the Cotton tensor arises in the context of the Bianchi identities and is present in any dimension. We present a systematic derivation of the Cotton tensor. We perform its irreducible decomposition and determine its number of independent components for the first time. Subsequently, we exhibit its characteristic properties and perform a classification of the Cotton tensor in three dimensions. We investigate some solutions of Einstein's field equations in three dimensions and of the topologically massive gravity model of Deser, Jackiw, and Templeton. For each class examples are given. Finally we investigate the relation between the Cotton tensor and the energy-momentum in Einstein's theory and derive a conformally flat perfect fluid solution of Einstein's field equations in three dimensions.Comment: 27 pages, revtex

    Regional action plan for the conservation of western chimpanzees (Pan troglodytes verus) 2020–2030

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    This is the final version. Available from IUCN via the DOI in this recordIn 2016, IUCN uplisted the western chimpanzee, Pan troglodytes verus, from “Endangered” to “Critically Endangered”, reflecting the subspecies’ increasingly dire conservation status. Of the four recognised chimpanzee subspecies, Pan troglodytes verus is under the greatest threat. The current plan presents the status and threats to P. t. verus, based on expert evaluation of the best scientific knowledge available to date. A considerable amount of new data has improved our knowledge of the distribution and status patterns of this subspecies since the first action plan was published in 2003, and an analysis of the threats to chimpanzee populations highlights the need to address these threats and their drivers. This action plan highlights how concerned stakeholders can harmonise their efforts, emphasising the critical role of regional coordination and inter- and multidisciplinary approaches in conserving the western chimpanzee. Finally, this plan also seeks to be dynamic, embedded in a monitoring and evaluation framework that will keep priorities and strategies relevant, updating objectives and information on threats as anthropogenic and ecological pressures evolve across West Africa.Arcus FoundationUnited States Fish & Wildlife Servic

    Разработка технологии изготовления червяка двухзаходного симметричного

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    Выпускная квалификационная работа на тему: Разработка технологии изготовления детали "Червяк двухзаходный симметричный" включает в себя разработанную операционную технологию механической обработки, размерный анализ детали, расчет режимов резания и норм времени. В конструкторском разделе спроектировано две разрезные втулки для фрезерной и токарной операций. Так же рассмотрены вопросы профессиональной и экологической безопасности и безопасность при ЧС. Выполнены оценки экономических аспектов разработки технологии изготовления.The final qualifying work on the topic: Development of the technology for the manufacture of the part "Double-start symmetric worm" includes the developed operating technology of machining, dimensional analysis of the part, calculation of cutting conditions and time norms. In the design section, two split bushings have been designed for milling and turning operations. The issues of professional and environmental safety and safety in case of emergency are also considered. Estimates of the economic aspects of the development of manufacturing technology have been carried out

    Haemoglobin mass and running time trial performance after recombinant human erythropoietin administration in trained men

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    <p>Recombinant human erythropoietin (rHuEpo) increases haemoglobin mass (Hbmass) and maximal oxygen uptake (v˙ O2 max).</p> <p>Purpose: This study defined the time course of changes in Hbmass, v˙ O2 max as well as running time trial performance following 4 weeks of rHuEpo administration to determine whether the laboratory observations would translate into actual improvements in running performance in the field.</p> <p>Methods: 19 trained men received rHuEpo injections of 50 IUNkg21 body mass every two days for 4 weeks. Hbmass was determined weekly using the optimized carbon monoxide rebreathing method until 4 weeks after administration. v˙ O2 max and 3,000 m time trial performance were measured pre, post administration and at the end of the study.</p> <p>Results: Relative to baseline, running performance significantly improved by ,6% after administration (10:3061:07 min:sec vs. 11:0861:15 min:sec, p,0.001) and remained significantly enhanced by ,3% 4 weeks after administration (10:4661:13 min:sec, p,0.001), while v˙ O2 max was also significantly increased post administration (60.765.8 mLNmin21Nkg21 vs. 56.066.2 mLNmin21Nkg21, p,0.001) and remained significantly increased 4 weeks after rHuEpo (58.065.6 mLNmin21Nkg21, p = 0.021). Hbmass was significantly increased at the end of administration compared to baseline (15.261.5 gNkg21 vs. 12.761.2 gNkg21, p,0.001). The rate of decrease in Hbmass toward baseline values post rHuEpo was similar to that of the increase during administration (20.53 gNkg21Nwk21, 95% confidence interval (CI) (20.68, 20.38) vs. 0.54 gNkg21Nwk21, CI (0.46, 0.63)) but Hbmass was still significantly elevated 4 weeks after administration compared to baseline (13.761.1 gNkg21, p<0.001).</p> <p>Conclusion: Running performance was improved following 4 weeks of rHuEpo and remained elevated 4 weeks after administration compared to baseline. These field performance effects coincided with rHuEpo-induced elevated v˙ O2 max and Hbmass.</p&gt
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