16,009 research outputs found

    Considerations about effective dissemination of improved fish strains

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    Aquaculture production systems in developing countries are largely based on the use of unimproved species and strains. As knowledge and experience are accumulated in relation to the management, feeding and animal health issues of such production systems, the availability of genetically more productive stock becomes imperative in order to more effectively use resources. For instance, there is little point in providing ideal water conditions and optimum feed quality to fish that do not have the potential to grow faster and to be harvested on time, providing a product of the desired quality. Refinements in the production system and improvement of the stock used must progress hand in hand. In this paper we deal separately with genetic and non-genetic issues pertaining to the multiplication and dissemination of improved strains. The separation is somewhat arbitrary, and as will be evident from our discussion, there is frequent interaction between the two

    Functional Genomics Profiling of Bladder Urothelial Carcinoma MicroRNAome as a Potential Biomarker.

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    Though bladder urothelial carcinoma is the most common form of bladder cancer, advances in its diagnosis and treatment have been modest in the past few decades. To evaluate miRNAs as putative disease markers for bladder urothelial carcinoma, this study develops a process to identify dysregulated miRNAs in cancer patients and potentially stratify patients based on the association of their microRNAome phenotype to genomic alterations. Using RNA sequencing data for 409 patients from the Cancer Genome Atlas, we examined miRNA differential expression between cancer and normal tissues and associated differentially expressed miRNAs with patient survival and clinical variables. We then correlated miRNA expressions with genomic alterations using the Wilcoxon test and REVEALER. We found a panel of six miRNAs dysregulated in bladder cancer and exhibited correlations to patient survival. We also performed differential expression analysis and clinical variable correlations to identify miRNAs associated with tobacco smoking, the most important risk factor for bladder cancer. Two miRNAs, miR-323a and miR-431, were differentially expressed in smoking patients compared to nonsmoking patients and were associated with primary tumor size. Functional studies of these miRNAs and the genomic features we identified for potential stratification may reveal underlying mechanisms of bladder cancer carcinogenesis and further diagnosis and treatment methods for urothelial bladder carcinoma

    Pairing effects on the collectivity of quadrupole states around 32Mg

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    The first 2+ states in N=20 isotones including neutron-rich nuclei 32Mg and 30Ne are studied by the Hartree-Fock-Bogoliubov plus quasiparticle random phase approximation method based on the Green's function approach. The residual interaction between the quasiparticles is consistently derived from the hamiltonian density of Skyrme interactions with explicit velocity dependence. The B(E2) transition probabilities and the excitation energies of the first 2+ states are well described within a single framework. We conclude that pairing effects account largely for the anomalously large B(E2) value and the very low excitation energy in 32Mg.Comment: 14 pages, 9 figure

    Investigation of Prediction Accuracy, Sensitivity, and Parameter Stability of Large-Scale Propagation Path Loss Models for 5G Wireless Communications

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    This paper compares three candidate large-scale propagation path loss models for use over the entire microwave and millimeter-wave (mmWave) radio spectrum: the alpha-beta-gamma (ABG) model, the close-in (CI) free space reference distance model, and the CI model with a frequency-weighted path loss exponent (CIF). Each of these models have been recently studied for use in standards bodies such as 3GPP, and for use in the design of fifth generation (5G) wireless systems in urban macrocell, urban microcell, and indoor office and shopping mall scenarios. Here we compare the accuracy and sensitivity of these models using measured data from 30 propagation measurement datasets from 2 GHz to 73 GHz over distances ranging from 4 m to 1238 m. A series of sensitivity analyses of the three models show that the physically-based two-parameter CI model and three-parameter CIF model offer computational simplicity, have very similar goodness of fit (i.e., the shadow fading standard deviation), exhibit more stable model parameter behavior across frequencies and distances, and yield smaller prediction error in sensitivity testing across distances and frequencies, when compared to the four-parameter ABG model. Results show the CI model with a 1 m close-in reference distance is suitable for outdoor environments, while the CIF model is more appropriate for indoor modeling. The CI and CIF models are easily implemented in existing 3GPP models by making a very subtle modification -- by replacing a floating non-physically based constant with a frequency-dependent constant that represents free space path loss in the first meter of propagation.Comment: Open access available at: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=743465

    Investigation into Nanocomposites for Applications in Lightning Strike Protection

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    The United States Air Force is continually researching ways to reduce costs associated with aircraft maintenance and improve operational safety. This study focuses on creating a systems engineering process to develop an Integrated Structural Health Monitoring System (ISHMS). The overarching process was then applied to design a conceptual ISHMS for a real-world scenario involving the F-15. Sensor selection, integration and testing were explored in detail using frequency response methods to detect structural damage. Testing was accomplished using a simplified structural specimen with Monitoring & Evaluation Technology Integration System (METIS) disk nodes attached at various locations. Two different METIS disk operation modes were utilized; pulse-echo and pitch-catch. Simulated and actual damage were introduced to the specimen allowing comparison between baseline and damaged tests. Comparative analysis validated the capabilities of frequency response sensors to detect damage. This analysis demonstrates that structural health monitoring systems using frequency response methods may be promising in the aerospace sector

    A time multiscale based data-driven approach in cyclic elasto-plasticity

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    Within the framework of computational plasticity, recent advances show that the quasi-static response of an elasto-plastic structure under cyclic loadings may exhibit a time multiscale behaviour. In particular, the system response can be computed in terms of time microscale and macroscale modes using a weakly intrusive multi-time Proper Generalized Decomposition (MT-PGD). In this work, such micro-macro characterization of the time response is exploited to build a data-driven model of the elasto-plastic constitutive relation. This can be viewed as a predictor-corrector scheme where the prediction is driven by the macrotime evolution and the correction is performed via a sparse sampling in space. Once the nonlinear term is forecasted, the multi-time PGD algorithm allows the fast computation of the total strain. The algorithm shows considerable gains in terms of computational time, opening new perspectives in the numerical simulation of history-dependent problems defined in very large time intervals

    Survey of Occupational Therapy Students\u27 Attitudes, Knowledge and Preparedness for Treating LGBT Clients

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    Members of lesbian, gay, bisexual and transsexual (LGBT) populations are sexual and gender minorities and are at risk for significant health disparities compared to heterosexual populations. This study examined occupational therapy students’ and recent graduates’ (n=435) basic knowledge, clinical preparedness and attitudinal awareness for working with LGBT clients using the Lesbian, Gay, Bisexual, and Transgender Development of Clinical Skills Scale (LGBT-DOCSS; Bidell, 2017). Students in the study generally rated themselves low (between three and four on a seven-point scale) on questions related to clinical preparedness, indicating they felt they did not have adequate training relative to working with LGBT clients. Both basic knowledge and clinical preparedness for working with LGBT populations was positively influenced by hours of curriculum content related to sexual minority populations. However, 21% (n=91) of participants reported the topic was not covered in the curriculum, while an additional 68% (n=295) reported less than two hours of time developed to LGBT topics. It is suggested that education focus on terminology, health disparities, an examination of personal and societal attitudes that affect outcomes, important health and psychosocial needs, culturally sensitive communication, creating inclusive practice setting and clinical practice and communication unique to this population

    Age, physical activity motivation and perceived stress in minority girls

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    Background: Physical activity in childhood and adolescence helps support physical and emotional health. Purpose: The study aimed to investigate if age was related to motivation for physical activity in minority girls, and whether the relationship may be potentially mediated by psychological or physiological stress. Methods: This cross-sectional observational study recruited Latino and African American girls ages 8 – 12 years (n = 79) in Tanner stage 1 or 2 via purposive sampling. Intrinsic motivation and perceived stress were measured by self-report survey; morning salivary cortisol samples were taken to calculate cortisol awakening response to estimate biological stress reactivity. Results: Increased age was related to higher intrinsic motivation to engage in physical activity. Lower perceived stress and lower awakening cortisol response were associated with higher intrinsic motivation. Bootstrapped mediation results indicated perceived stress may be a pathway through which age impacts intrinsic motivation for physical activity. Conclusion: While motivation to engage in physical activity may increase with age, perceived stress may dampen this motivation, resulting in decreased physical activity. Interventions to help increase pre-adolescent girls’ engagement in active behaviors may benefit from reducing children’s perceptions of stress

    Survey of Occupational Therapy Students\u27 Attitudes, Knowledge and Preparedness for Treating LGBT Clients

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    Members of lesbian, gay, bisexual and transsexual (LGBT) populations are sexual and gender minorities and are at risk for significant health disparities compared to heterosexual populations. This study examined occupational therapy students’ and recent graduates’ (n=435) basic knowledge, clinical preparedness and attitudinal awareness for working with LGBT clients using the Lesbian, Gay, Bisexual, and Transgender Development of Clinical Skills Scale (LGBT-DOCSS; Bidell, 2017). Students in the study generally rated themselves low (between three and four on a seven-point scale) on questions related to clinical preparedness, indicating they felt they did not have adequate training relative to working with LGBT clients. Both basic knowledge and clinical preparedness for working with LGBT populations was positively influenced by hours of curriculum content related to sexual minority populations. However, 21% (n=91) of participants reported the topic was not covered in the curriculum, while an additional 68% (n=295) reported less than two hours of time developed to LGBT topics. It is suggested that education focus on terminology, health disparities, an examination of personal and societal attitudes that affect outcomes, important health and psychosocial needs, culturally sensitive communication, creating inclusive practice setting and clinical practice and communication unique to this population

    A time multiscale decomposition in cyclic elasto-plasticity

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    For the numerical simulation of time-dependent problems, recent works suggest the use of a time marching scheme based on a tensorial decomposition of the time axis. This time-separated representation is straightforwardly introduced in the framework of the Proper Generalized Decomposition (PGD). The time coordinate is transformed into a multi-dimensional time through new separated coordinates, the micro and the macro times. From a physical viewpoint, the time evolution of all the quantities involved in the problem can be followed along two time scales, the fast one (micro-scale) and the slow one (macro-scale). In this paper, the method is applied to compute the quasi-static response of an elasto-plastic structure under cyclic loadings. The study shows the existence of a physically consistent temporal decomposition in computational cyclic plasticity. Such micro-macro characterization may be particularly appealing in high-cycle loading analyses, such as aging and fatigue, addressed in a future work in progress
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