6,261 research outputs found

    Prediction of energy dissipation in violent sloshing flows simulated by Smoothed Particle Hydrodynamics

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    Prediction of energy dissipation in violent sloshing flows simulated by Smoothed Particle Hydrodynamic

    Extended computation of the viscous Rayleigh-Taylor instability in a horizontally confined flow

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    In this article, the classical Rayleigh-Taylor instability is extended to situations where the fluid is completely confined, in both the vertical and horizontal directions. This article starts with the two-dimensional (2D) viscous periodic case with finite height where the effect of adding surface tension to the interface is analyzed. This problem is simulated from a dual perspective: first, the linear stability analysis obtained when the Navier-Stokes equations are linearized and regularized in terms of density and viscosity; and second, looking at the weakly compressible version of a multiphase smoothed particle hydrodynamics (WCSPH) method. The evolution and growth rates of the different fluid variables during the linear regime of the SPH simulation are compared to the computation of the eigenvalues and eigenfunctions of the viscous version of the Rayleigh-Taylor stability (VRTI) analysis with and without surface tension. The most unstable mode, which has the maximal linear growth rate obtained with both approaches, as well as other less unstable modes with more complex structures are reported. The classical horizontally periodic (VRTI) case is now adapted to the case where two additional left and right walls are included in the problem, representing the cases where a two-phase flow is confined in a accelerated tank. This 2D case where no periodic assumptions are allowed is also solved using both techniques with tanks of different sizes and a wide range of Atwood numbers. The agreement with the linear stability analysis obtained by a Lagrangian method such as multiphase WCSPH is remarkable.The research leading to these results was undertaken as part of the SLOWD project, which has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant No. 815044. L.M.G. acknowledges the financial support from the Spanish Ministry for Science, Innovation and Universities (MCIU) under Grant No. RTI2018-096791-B-C21, Hidrodinámica de elementos de amortiguamiento del movimiento de aerogeneradores flotantes

    CP Violation in \tau ->\nu\pi K_S and D->\pi K_S: The Importance of K_S-K_L Interference

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    The BB-factories have measured CP asymmetries in the τπKSν\tau\to\pi K_S\nu and DKSπD\to K_S\pi modes. The KSK_S state is identified by its decay to two pions at a time that is close to the KSK_S lifetime. Within the Standard Model and many of its extensions, the asymmetries in these modes come from CP violation in K0Kˉ0K^0-\bar{K}^0 mixing. We emphasize that the interference between the amplitudes of intermediate KSK_S and KLK_L is as important as the pure KSK_S amplitude. Consequently, the measured asymmetries depend on the times over which the relevant decay rates are integrated and on features of the experiment.Comment: 4 pages, 4 figure

    At the southeast fringe of the Bantu expansion: genetic diversity and phylogenetic relationships to other sub-Saharan tribes

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    Here, we present 12 loci paternal haplotypes (Y-STR profiles) against the backdrop of the Y-SNP marker system of Bantu males from the Maputo Province of Southeast Africa, a region believed to represent the southeastern fringe of the Bantu expansion. Our Maputo Bantu group was analyzed within the context of 27 geographically relevant reference populations in order to ascertain its genetic relationship to other Bantu and non Bantu (Pygmy, Khoisan and Nilotic) sub-equatorial tribes from West and East Africa. This study entails statistical pair wise comparisons and multidimensional scaling based on YSTR Rst distances, network analyses of Bantu (B2a-M150) and Pygmy (B2b-M112) lineages as well as an assessment of Y-SNP distribution patterns. Several notable findings include the following: 1) the Maputo Province Bantu exhibits a relatively close paternal affinity with both east and west Bantu tribes due to high proportion of Bantu Y chromosomal markers, 2) only traces of Khoisan (1.3%) and Pygmy (1.3%) markers persist in the Maputo Province Bantu gene pool, 3) the occurrence of R1a1a-M17/M198, a member of the Eurasian R1a-M420 branch in the population of the Maputo Province, may represent back migration events and/or recent admixture events, 4) the shared presence of E1b1b1-M35 in all Tanzanian tribes examined, including Bantu and non-Bantu groups, in conjunction with its nearly complete absence in the West African populations indicate that, in addition to a shared linguistic, cultural and genetic heritage, geography (e.g., east vs. west) may have impacted the paternal landscape of sub-Saharan Africa, 5) the admixture and assimilation processes of Bantu elements were both highly complex and region-specific

    Cancer Survivors\u27 Self-Efficacy and Spirituality Outcomes Following a Holistic Integrative Intervention

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    Cancer treatments often negatively impact health-related quality of life (HR-QOL) for cancer survivors (CS), ignoring the multi-dimensional nature of the human experience of cancer and its impact on mental and spiritual domains. A holistic integrative approach was implemented on a heterogenous population of cancer survivors during the COVID epidemic with the goal of improving their overall well-being by looking beyond physical functioning. PURPOSE: To examine the relationship between spirituality and self-efficacy of cancer survivors of all types of cancer following a holistic intervention during the COVID-19 pandemic. METHODS: Subjects were recruited via network partners and self-referral. Subjects were eligible to participate if they were cancer survivors of any type at any stage of cancer treatment; subjects were ineligible to participate if they presented with any absolute contraindications to exercise testing as per ACSM guidelines. For 16 weeks, subjects were asked to participate in three 75-minute sessions of therapeutic yoga-based with loving kindness meditation per week. Psychosocial support text messages were sent daily to subjects based on their motivational state to encourage participation in these health enhancing behaviors. Data was collected through numerous channels including BlueJay Mobile Telehealth medicine application. RESULTS: A total of 29 survivors provided informed consent. The average age of the subjects was 58.9 years, 25 female survivors and 4 male survivors; 11 of the 29 self-reported as Latino/ Hispanic. The 29 subjects were survivors of the following primary cancers: breast cancer (n=21), cervical cancer (n=2), ovarian cancer (n=1), prostate cancer (n=1), sarcoma (n=1), lymphoma (n=1), thyroid cancer (n=1), or leukemia (n=1). There is a positive association between how confident a cancer survivor feels towards performing exercise in various situations and the amount of social support they receive from their family (p\u3c.001) and friends (p\u3c.001). The individual’s confidence to overcome the obstacle to exercise and their level of hope are associated with the support they receive from loved ones. CONCLUSION: The present study suggests that to improve exercise behavior in adult cancer survivors, one should incorporate social support to strengthen barriers self-efficacy to improve outcome expectations. To further understand these associations, longitudinal research is needed and should include more survivors

    Vertical Transmission of Pneumocystis jirovecii in Humans

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    This study is part of the project “Pneumocystis Pathogenomics: Unravelling the Colonization-to-Disease Shift,” a Coordination Action supported by the European Commission (ERANET PathoGenoMics). This study was partially supported by the Spanish Ministry of Health (FIS 03/1743). M.A.M.-C. and C.d.l.H. were supported by the Spanish Ministry of Health (FIS CP-04/217 and FIS CM-04/146).Ye

    AKT Signaling Mediates IGF-I Survival Actions on Otic Neural Progenitors

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    Background: Otic neurons and sensory cells derive from common progenitors whose transition into mature cells requires the coordination of cell survival, proliferation and differentiation programmes. Neurotrophic support and survival of post-mitotic otic neurons have been intensively studied, but the bases underlying the regulation of programmed cell death in immature proliferative otic neuroblasts remains poorly understood. The protein kinase AKT acts as a node, playing a critical role in controlling cell survival and cell cycle progression. AKT is activated by trophic factors, including insulin-like growth factor I (IGF-I), through the generation of the lipidic second messenger phosphatidylinositol 3-phosphate by phosphatidylinositol 3-kinase (PI3K). Here we have investigated the role of IGF-dependent activation of the PI3K-AKT pathway in maintenance of otic neuroblasts. Methodology/Principal Findings: By using a combination of organotypic cultures of chicken (Gallus gallus) otic vesicles and acoustic-vestibular ganglia, Western blotting, immunohistochemistry and in situ hybridization, we show that IGF-I-activation of AKT protects neural progenitors from programmed cell death. IGF-I maintains otic neuroblasts in an undifferentiated and proliferative state, which is characterised by the upregulation of the forkhead box M1 (FoxM1) transcription factor. By contrast, our results indicate that post-mitotic p27Kip-positive neurons become IGF-I independent as they extend their neuronal processes. Neurons gradually reduce their expression of the Igf1r, while they increase that of the neurotrophin receptor, TrkC. Conclusions/Significance: Proliferative otic neuroblasts are dependent on the activation of the PI3K-AKT pathway by IGF-I for survival during the otic neuronal progenitor phase of early inner ear development

    Mechanical Biosensors in Biological and Food Area: a Review

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    A review of state the art about the structure, classification and operation of biosensors applied in food and biological areas is presented. This review is focused to mechanical biosensors that use mill, micro and nanocantilevers. Basic concepts of atomic force microscopy and optical systems, used as testing platform of biosensors are described. The most funcionalized strategies and geometrical configurations are also explained. Mathematical methods for evaluating the performance in static and dynamic mode of the mechanical biosensors are reviewed and examples of application in biological and food areas are provided. An overall description of the operational effect of operation conditions and design variables on the sensitivity devices is also proposed. A brief description of the design processes and manufacturing of cantilevers based silicon technology as well as information about BioMEMS and BioNEMS are provided. Finally, overall tends in research, development and commercialization of biosensors are described briefly as well as probable areas of development in food biosensors. Thereby, this review provides an overall view of biosensors, as an exploratory guide to identify the most important aspects of this technology
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