864 research outputs found

    Transformation of 17a-methyltestosterone in aquatic-sediment systems

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    Two sediment samples that differed with respect to total organic carbon and texture (“sand” and “clay”) were exposed to radio inert 17a-methyltestosterone (MT) or [14C]-radiolabeled 17a-methyltestosterone (14C-MT), under both aerobic and anaerobic conditions, for up to 56 days, to characterize the fate of MT in the aquatic environment. Radio inert MT was quantified by a highly sensitive liquid chromatography/mass spectrometry (LCMS) method and radioactive MT was quantified by HPLC using an in-line flow liquid scintillation counter (LSC). Thedata suggest that MT entering the aquatic environment is converted into metabolites that become tightly associated with the sediment. Half-lives for MT dissipation in the sediment systems ranged from 2-9 days, depending on the sediment type and the presence of oxygen. Sediment type had little effect on MT dissipation. The mineralization of MT under aerobic conditions was low (<9% conversion of MT to CO2)

    Development and validation of a High performance liquid chromatography- Mass spectrometry method for 17a-methyltestosterone in Aquatic water systems

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    17a-Methyltestosterone is used as feed additive to manipulate the gender of fish for aquaculture. Earlier a simple, yet specific and robust validated high performance liquid chromatographic method has been developed for the determination of 17a-methyltestosterone in fish feed. The present work describes a highly sensitive and robust Liquid Chromatography-Mass Spectrometry method for the quantitation of 17a-methyltestosterone in aquatic water systems using 17â-hydroxy-3â-methoxyandrost-5-en-7-one as internal standard. The method was validated in the concentration range of 0.2 to 25 ng of 17a-methyltestosterone on column leading to a limit of quantitation of 0.08 ppb or 0.08 mg/L in water, and has potential to increase the limit of detection and quantitation by an order of magnitude, if required

    Lack of growth enhancement by exogenous growth hormone treatment in yellow perch (Perca flavescens) in four separate experiments

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    Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B. V. for personal use, not for redistribution. The definitive version was published in Aquaculture 250 (2005): 471-479, doi:10.1016/j.aquaculture.2005.03.019.The effect of exogenous growth hormone (GH) treatment on the growth of juvenile yellow perch (Perca flavescens) was investigated in four experiments. In the first two experiments, juvenile yellow perch were reared at either 13°C or 21°C, and injected weekly with bovine GH (bGH) at 0.1, 1.0 or 10.0 μg/g body weight for 84 days. No significant growth enhancement in GH-treated fish was measured in fish in either of the experiments. In the third experiment, juvenile yellow perch were treated with estradiol-17β (E2, 15 μg/g of diet), bGH (1.0 μg/g body weight) injected weekly or both hormones for 70 days at 21°C. E2 alone stimulated growth, but no further growth stimulation occurred in the E2 + bGH-treated fish. In addition, no growth enhancement was found in fish treated with bGH alone. We measured no difference in serum insulin-like growth factor-I (IGF-I) levels between the treatment groups at 12 and 24 h after the final injection of GH; however, a drop in IGF-I levels after 24 h was observed. In a fourth study, the effect of recombinant yellow perch GH (rypGH, 0.2 or 1.0 μg/g body weight) injected weekly was evaluated in yellow perch juveniles. The fish were reared for 42 days at 18°C. Neither GH dosages improved growth compared to control-injected and non-injected fish. Taken together, the lack of effect of mammalian GH or rypGH in our experiments suggests (1) low binding affinity between these hormones and the GH receptor in yellow perch, (2) that the endogenous GH levels were already at biologically maximal levels or (3) that other endocrine factors are needed in order for GH to promote yellow perch growth. The reduction in IGF-I levels 24 h after handling suggests a negative effect of handling stress on the GH-IGF-I axis in yellow perch.This work was supported by the University of Wisconsin-Madison College of Agricultural and Life Sciences and School of Natural Resources; the Wisconsin Department of Natural Resources; the University of Wisconsin Sea Grant College Program, National Oceanic and Atmospheric Administration, US Department of Commerce; the State of Wisconsin (Federal Grant NA46RG0481, Project No. R/AQ-38); and the USDA NOAA Project R/A-05-99, grant #NA86RG0048 to FG and SR. This study was also funded by the Norwegian Research Council (NFR)

    Attitudes and Performance: An Analysis of Russian Workers

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    This paper investigates the relationship between locus of control and performance among Russian employees, using survey data collected at 28 workplaces in 2002 in Taganrog and at 47 workplaces in 2003 in Ekaterinburg. We develop a measure that allows us to categorize the Russian employees participating in our survey as exhibiting an internal or external locus of control. We then assess the extent to which there are significant differences between “internals” and “externals” in work-related attitudes that may affect performance. In particular, we focus on (1) attitudes about outcomes associated with hard work, (2) level of job satisfaction, (3) expectation of receiving a desired reward, and (4) loyalty to and involvement with one’s organization. In each case we identify where gender and generational differences emerge. Our main objective is to determine whether Russian employees who exhibit an internal locus of control perform better than employees with an external locus of control. Our performance measures include earnings, expected promotions, and assessments of the quantity and quality of work in comparison to others at the same organization doing a similar job. Controlling for a variety of worker characteristics, we find that (1) individuals who exhibit an internal locus of control perform better, but this result is not always statistically significant; (2) even among “internals,” women earn significantly less than men and have a much lower expectation of promotion; (3) even among “internals,” experience with unemployment has a negative influence on performance.http://deepblue.lib.umich.edu/bitstream/2027.42/40144/3/wp758.pd

    Statin use is not associated with future long-term care admission - extended follow-up of two randomised controlled trials

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    Background: Statins have been associated with later life, long-term care admission in observational studies. However, by preventing vascular events, statins may also prevent or delay admission. We wished to determine statin and long-term care admission associations in a randomised controlled trial context, and describe associations between long-term care admission and other clinical and demographic factors. Methods: We used extended follow-up of two randomised trial populations, using national data to assign the long-term care admission outcome, and included individuals screened or recruited to two large randomised trials of pravastatin 40 mg daily—the West of Scotland Coronary Prevention Study (WOSCOPS) and the pravastatin in elderly individuals at risk of vascular disease (PROSPER) study. We described univariable and multivariable analyses of potential predictors of long-term care admission with corresponding survival curves of incident long-term care admission and analyses adjusted for competing risk. Results: In total 11,015 (10%) of the trial participants were admitted to long-term care. There was no difference between participants in the statin or placebo arms of either trial in regard to admissions to long-term care. On multivariable analyses, independent associations with incident long-term care admission in the PROSPER trial were age (hazard ratio [HR] 1.06 per year, 95% confidence interval [CI] 1.03–1.09) and male sex (HR 0.72, 95% CI 0.53–0.99). In the WOSCOPS, age (HR 1.12 per year, 95% CI 1.10–1.13) and increasing social deprivation (HR 1.05, 95% CI 1.03–1.08) were associated with incident long-term care admission. Conclusion: We did not demonstrate an association between historical statin use and future long-term care admission. The strongest associations with incident long-term care admission were non-modifiable factors of age, sex and socioeconomic deprivation

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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