4,155 research outputs found
Gradient jump penalty stabilisation of spectral/hp element discretisation for under-resolved turbulence simulations
One of the strengths of the discontinuous Galerkin (DG) method has been its balance between accuracy and robustness, which stems from DG’s intrinsic (upwind) dissipation being biased towards high
frequencies/wavenumbers. This is particularly useful in high Reynolds-number flow simulations where
limitations on mesh resolution typically lead to potentially unstable under-resolved scales. In continuous Galerkin (CG) discretisations, similar properties are achievable through the addition of artificial
diffusion, such as spectral vanishing viscosity (SVV). The latter, although recognised as very useful in
CG-based high-fidelity turbulence simulations, has been observed to be sub-optimal when compared to
DG at intermediate polynomials orders (P ≈ 3). In this paper we explore an alternative stabilisation
approach by the introduction of a continuous interior penalty on the gradient discontinuity at elemental
boundaries, which we refer to as a gradient jump penalisation (GJP). Analogous to DG methods, this
introduces a penalisation at the elemental interfaces as opposed to the interior element stabilisation of
SVV. Detailed eigenanalysis of the GJP approach shows its potential as equivalent (sometimes superior)
to DG dissipation and hence superior to previous SVV approaches. Through eigenanalysis, a judicious
choice of GJP’s P-dependent scaling parameter is made and found to be consistent with previous apriori error analysis. The favourable properties of the GJP stabilisation approach are also supported by
turbulent flow simulations of the incompressible Navier-Stokes equation, as we achieve high-quality flow
solutions at P = 3 using GJP, whereas SVV performs marginally worse at P = 5 with twice as many
degrees of freedom in total
OS CONCEITOS DE MORTE E MORRER NA ENFERMAGEM E AS RELAÇÕES COM O ETHOS DO CUIDADO
In this study, we analyze the influence of the concepts of death and dying of the nursing staff on the practice of care given in some areas of hospitalization. The data was produced by from a questionnaire containing open ended questions. The subjects of the investigation nurses, technicians and nurses’ auxiliaries who act in the sectors of the medical clinic, the center of intensive care and emergency in public hospitals in the city of Rio de Janeiro, Brazil. After the analysis of the data, two categories emerged: the INFLUENCE and CONFLICT of the concepts about death in the CHOICE and DYNAMICS of ethos of care and death: BEGINNING a new life and END of everything. The results point that the concepts of do not change among the nursing professionals who work in the units studied, and also it seems not to have influenced them when they chose their ethos of care giving. It draws attention that professionals in these units relate a conflict when thinking of death and facing it in their daily care.En este estudio analizamos la influencia de los conceptos de muerte y morir del equipo de Enfermería sobre las prácticas de cuidados en algunos espacios de internación hospitalaria. Los datos se produjeron a partir de la aplicación de un formulario conteniendo preguntas abiertas, siendo los sujetos de la investigación Enfermeros, Técnicos y Auxiliares de Enfermería que actúan en los sectores de Clínica Médica, Unidad de Terapia Intensiva y Emergencia de hospitales de la red pública localizados en el municipio de Rio de Janeiro. Después del análisis de los datos, emergieron dos categorías: la INFLUENCIA y el CONFLICTO de los conceptos acerca de la muerte en la ELECCIÓN y en la DINÁMICA de del ethos del cuidado, y Muerte: INICIO de una nueva vida y FIN de todo. Los resultados apuntan que los conceptos de muerte no se alteran entre los profesionales de enfermería que actúan en esas unidades investigadas y también parece no haberles influenciado cuando eligieron sus ethos para cuidar. Llama la atención que los profesionales entrevistados relataron conflicto en el pensar la muerte y en encararla en su cotidianidad de cuidar.Neste estudo, analisamos a influência dos conceitos de morte e morrer da equipe de Enfermagem sobre as práticas de cuidar em alguns espaços de internação hospitalar. Os dados foram produzidos a partir da aplicação de um formulário contendo perguntas abertas, sendo os sujeitos da pesquisa, Enfermeiros, Técnicos e Auxiliares de Enfermagem que atuam nos setores de Clínica Médica, Unidade de Terapia Intensiva e Emergência de hospitais da rede pública localizados no município do Rio de Janeiro. Após a análise dos dados, emergiram duas categorias: A INFLUÊNCIA e o CONFLITO dos conceitos acerca da morte na ESCOLHA e na DINAMICA do ethos do cuidado; e Morte: INICIO de uma nova vida e FIM de tudo. Os resultados apontam que os conceitos de morte não se alteram entre os profissionais de enfermagem que atuam nessas unidades pesquisadas e também parece não ter os influenciado quando escolheram os seus ethos para cuidar. Chama atenção que os profissionais entrevistados relataram conflito no pensar a morte, e de encará-la em seu cotidiano de cuidar.
Sex and lifestyle dictate learning performance in a neotropical wasp
In contrast to extensive investigations on bee cognition, the cognitive capacities of wasps remain largely unexplored despite their key role as pollinators and predators of insect pests. Here we studied learning and memory in the neotropical wasp Mischocyttarus cerberus using a Pavlovian conditioning in which harnessed wasps respond with conditioned movements of their mouthparts to a learned odorant. We focused on the different castes, sexes, and ages coexisting within a nest and found that adults of M. cerberus learned and memorized efficiently the odor-sugar associations. In contrast, newly emerged females, but not males, were unable to learn odorants. This difference concurs with their different lifestyle as young males perform regular excursions outside the nest while young females remain in it until older age. Our results thus highlight the importance of socio-ecological constraints on wasp cognition and set the basis for mechanistic studies on learning differences across ages and castes
A comparison of research data management platforms: architecture, flexible metadata and interoperability
Research data management is rapidly becoming a regular concern for researchers, and institutions need to provide them with platforms to support data organization and preparation for publication. Some institutions have adopted institutional repositories as the basis for data deposit, whereas others are experimenting with richer environments for data description, in spite of the diversity of existing workflows. This paper is a synthetic overview of current platforms that can be used for data management purposes. Adopting a pragmatic view on data management, the paper focuses on solutions that can be adopted in the long tail of science, where investments in tools and manpower are modest. First, a broad set of data management platforms is presented-some designed for institutional repositories and digital libraries-to select a short list of the more promising ones for data management. These platforms are compared considering their architecture, support for metadata, existing programming interfaces, as well as their search mechanisms and community acceptance. In this process, the stakeholders' requirements are also taken into account. The results show that there is still plenty of room for improvement, mainly regarding the specificity of data description in different domains, as well as the potential for integration of the data management platforms with existing research management tools. Nevertheless, depending on the context, some platforms can meet all or part of the stakeholders' requirements
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24-Week β-alanine ingestion does not affect muscle taurine or clinical blood parameters in healthy males
Purpose: To investigate the effects of chronic beta-alanine (BA) supplementation on muscle taurine content, blood clinical markers and sensory side-effects.
Methods: Twenty-five healthy male participants (age 27±4 years, height 1.75±0.09 m, body mass 78.9±11.7 kg) were supplemented with 6.4 g day−1 of sustained-release BA (N=16; CarnoSyn™, NAI, USA) or placebo (PL; N=9; maltodextrin) for 24 weeks. Resting muscle biopsies of the m. vastus lateralis were taken at 0, 12 and 24 weeks and analysed for taurine content (BA, N=12; PL, N=6) using high-performance liquid chromatography. Resting venous blood samples were taken every 4 weeks and analysed for markers of renal, hepatic and muscle function (BA, N=15; PL, N=8; aspartate transaminase; alanine aminotransferase; alkaline phosphatase; lactate dehydrogenase; albumin; globulin; creatinine; estimated glomerular filtration rate and creatine kinase).
Results :There was a significant main effect of group (p=0.04) on muscle taurine, with overall lower values in PL, although there was no main effect of time or interaction effect (both p>0.05) and no differences between specific timepoints (week 0, BA: 33.67±8.18 mmol kg−1 dm, PL: 27.75±4.86 mmol kg−1 dm; week 12, BA: 35.93±8.79 mmol kg−1 dm, PL: 27.67±4.75 mmol kg−1 dm; week 24, BA: 35.42±6.16 mmol kg−1 dm, PL: 31.99±5.60 mmol kg−1 dm). There was no effect of treatment, time or any interaction effects on any blood marker (all p>0.05) and no self-reported side-effects in these participants throughout the study.
Conclusions: The current study showed that 24 weeks of BA supplementation at 6.4 g day−1 did not significantly affect muscle taurine content, clinical markers of renal, hepatic and muscle function, nor did it result in chronic sensory side-effects, in healthy individuals. Since athletes are likely to engage in chronic supplementation, these data provide important evidence to suggest that supplementation with BA at these doses for up to 24 weeks is safe for healthy individuals
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Twenty-four weeks of β-alanine supplementation on carnosine content, related genes, and exercise
Introduction: Skeletal muscle carnosine content can be increased through [beta]-alanine supplementation, but the maximum increase achievable with supplementation is unknown. No study has investigated the effects of prolonged supplementation on carnosine-related genes or exercise capacity.
Purpose: To investigate the effects of 24-weeks of [beta]-alanine supplementation on muscle carnosine content, gene expression and high-intensity cycling capacity (CCT110%).
Methods: Twenty-five active males were supplemented with 6.4 g[middle dot]day-1 of sustained release [beta]-alanine (BA) or placebo (PL) over a 24-week period. Every 4 weeks participants provided a muscle biopsy and performed the CCT110%. Biopsies were analysed for muscle carnosine content and gene expression (CARNS, TauT, ABAT, CNDP2, PHT1, PEPT2 and PAT1).
Results: Carnosine content was increased from baseline at every time point in BA (all P<0.0001; Week 4: +11.37+/-7.03 mmol[middle dot]kg-1dm, Week 8: +13.88+/-7.84 mmol[middle dot]kg-1dm, Week 12: +16.95+/-8.54 mmol[middle dot]kg-1dm, Week 16: +17.63+/-8.42 mmol[middle dot]kg-1dm, Week 20: +21.20+/-7.86 mmol[middle dot]kg-1dm, Week 24: +20.15+/-7.63 mmol[middle dot]kg-1dm), but not PL (all P=1.00). Maximal changes were +25.66+/-7.63 mmol[middle dot]kg-1dm (range: +17.13 to +41.32 mmol[middle dot]kg-1dm), and absolute maximal content was 48.03+/-8.97 mmol[middle dot]kg-1dm (range: 31.79 to 63.92 mmol[middle dot]kg-1dm). There was an effect of supplement (P=0.002) on TauT; no further differences in gene expression were shown. Exercise capacity was improved in BA (P=0.05) with possible to almost certain improvements across all weeks.
Conclusions: Twenty-four weeks of [beta]-alanine supplementation increased muscle carnosine content and improved high-intensity cycling capacity. Downregulation of TauT suggests it plays an important role in muscle carnosine accumulation with [beta]-alanine supplementation, while the variability in changes in muscle carnosine content between individuals suggests that other determinants other than the availability of [beta]-alanine may also bear a major influence on muscle carnosine content
Health assessment of the oyster Crassostrea rhizophorae on the southern coast of Bahia, northeastern Brazil
Genotyping of Toxoplasma gondii and Sarcocystis spp. in road-killed wild mammals from the Central Western Region of the State of São Paulo, Brazil
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