The genetic diversity and geographical separation study of Oncomelania hupensis populations in mainland China using microsatellite loci

© 2016 Guan et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article.NHM Repositor

The cascade structure of linear instability in collapsible channel flows

This paper studies the unsteady behaviour and linear stability of the flow in a collapsible channel using a fluid–beam model. The solid mechanics is analysed in a plane strain configuration, in which the principal stretch is defined with a zero initial strain. Two approaches are employed: unsteady numerical simulations solving the nonlinear fully coupled fluid–structure interaction problem; and the corresponding linearized eigenvalue approach solving the Orr–Sommerfeld equations modified by the beam. The two approaches give good agreement with each other in predicting the frequencies and growth rates of the perturbation modes, close to the neutral curves. For a given Reynolds number in the range of 200–600, a cascade of instabilities is discovered as the wall stiffness (or effective tension) is reduced. Under small perturbation to steady solutions for the same Reynolds number, the system loses stability by passing through a succession of unstable zones, with mode number increasing as the wall stiffness is decreased. It is found that this cascade structure can, in principle, be extended to many modes, depending on the parameters. A puzzling ‘tongue’ shaped stable zone in the wall stiffness–Re space turns out to be the zone sandwiched by the mode-2 and mode-3 instabilities. Self-excited oscillations dominated by modes 2–4 are found near their corresponding neutral curves. These modes can also interact and form period-doubling oscillations. Extensive comparisons of the results with existing analytical models are made, and a physical explanation for the cascade structure is proposed

A comparison of the physical demands of a one-day cricket game and the training sessions of provincial cricket players using Global Positioning System tracking software

Background: Cricket is a highly technical skills-based game and coaches consequently focus on the improvement of skills during training sessions. However, a certain level of physical fitness is required to execute these skills optimally. Coaches tend to give little focused attention to the development of physical fitness during training, which could lead to players being physically unprepared for the demands of a game.  Objective: The purpose of this study was to assess and compare the physical demands of a one-day cricket game and a training session of provincial cricket players, using Global Positioning System units.  Methods: Nineteen male provincial cricketers participated in the research. The participants were classified into five sub-disciplines, namely, batting, fast bowling, spin bowling, fielding and wicketkeeping. The study employed a descriptive and comparative design as it essentially collected numerical data from Global Positioning System units to describe and compare the physical demands of a one-day game of cricket and a training session preceding these games. The variables used in the study included total distances travelled in the game which were divided into five movement categories, i.e. walking, jogging, running, striding and sprinting. Also included were average and maximum heart rates, number of sprints and average sprint distances.  Results: There were significant differences across all sub-disciplines and movement categories during training and the one-day game for provincial cricket players. Batsmen showed the greatest discrepancies between training and the game for all high-intensity movements (p<0.05).  Conclusion: The findings of this study highlight the different physical and physiological demands placed on players in the various sub-disciplines during training and the one-day game. The current study found the major disparity between training and the one-day game was amongst the batsmen.&nbsp

A comparison of the physical demands of a one-day cricket game and the training sessions of provincial cricket players using Global Positioning System tracking software

Background: Cricket is a highly technical skills-based game and coaches consequently focus on the improvement of skills during training sessions. However, a certain level of physical fitness is required to execute these skills optimally. Coaches tend to give little focused attention to the development of physical fitness during training, which could lead to players being physically unprepared for the demands of a game.  Objective: The purpose of this study was to assess and compare the physical demands of a one-day cricket game and a training session of provincial cricket players, using Global Positioning System units.  Methods: Nineteen male provincial cricketers participated in the research. The participants were classified into five sub-disciplines, namely, batting, fast bowling, spin bowling, fielding and wicketkeeping. The study employed a descriptive and comparative design as it essentially collected numerical data from Global Positioning System units to describe and compare the physical demands of a one-day game of cricket and a training session preceding these games. The variables used in the study included total distances travelled in the game which were divided into five movement categories, i.e. walking, jogging, running, striding and sprinting. Also included were average and maximum heart rates, number of sprints and average sprint distances.  Results: There were significant differences across all sub-disciplines and movement categories during training and the one-day game for provincial cricket players. Batsmen showed the greatest discrepancies between training and the game for all high-intensity movements (p<0.05).  Conclusion: The findings of this study highlight the different physical and physiological demands placed on players in the various sub-disciplines during training and the one-day game. The current study found the major disparity between training and the one-day game was amongst the batsmen.&nbsp

A comparison of the physical demands of a one-day cricket game and the training sessions of provincial cricket players using Global Positioning System tracking software

Background: Cricket is a highly technical skills-based game and coaches consequently focus on the improvement of skills during training sessions. However, a certain level of physical fitness is required to execute these skills optimally. Coaches tend to give little focused attention to the development of physical fitness during training, which could lead to players being physically unprepared for the demands of a game.  Objective: The purpose of this study was to assess and compare the physical demands of a one-day cricket game and a training session of provincial cricket players, using Global Positioning System units.  Methods: Nineteen male provincial cricketers participated in the research. The participants were classified into five sub-disciplines, namely, batting, fast bowling, spin bowling, fielding and wicketkeeping. The study employed a descriptive and comparative design as it essentially collected numerical data from Global Positioning System units to describe and compare the physical demands of a one-day game of cricket and a training session preceding these games. The variables used in the study included total distances travelled in the game which were divided into five movement categories, i.e. walking, jogging, running, striding and sprinting. Also included were average and maximum heart rates, number of sprints and average sprint distances.  Results: There were significant differences across all sub-disciplines and movement categories during training and the one-day game for provincial cricket players. Batsmen showed the greatest discrepancies between training and the game for all high-intensity movements (p<0.05).  Conclusion: The findings of this study highlight the different physical and physiological demands placed on players in the various sub-disciplines during training and the one-day game. The current study found the major disparity between training and the one-day game was amongst the batsmen.&nbsp

A comparison of the physical demands of a one-day cricket game and the training sessions of provincial cricket players using Global Positioning System tracking software

Background: Cricket is a highly technical skills-based game and coaches consequently focus on the improvement of skills during training sessions. However, a certain level of physical fitness is required to execute these skills optimally. Coaches tend to give little focused attention to the development of physical fitness during training, which could lead to players being physically unprepared for the demands of a game.  Objective: The purpose of this study was to assess and compare the physical demands of a one-day cricket game and a training session of provincial cricket players, using Global Positioning System units.  Methods: Nineteen male provincial cricketers participated in the research. The participants were classified into five sub-disciplines, namely, batting, fast bowling, spin bowling, fielding and wicketkeeping. The study employed a descriptive and comparative design as it essentially collected numerical data from Global Positioning System units to describe and compare the physical demands of a one-day game of cricket and a training session preceding these games. The variables used in the study included total distances travelled in the game which were divided into five movement categories, i.e. walking, jogging, running, striding and sprinting. Also included were average and maximum heart rates, number of sprints and average sprint distances.  Results: There were significant differences across all sub-disciplines and movement categories during training and the one-day game for provincial cricket players. Batsmen showed the greatest discrepancies between training and the game for all high-intensity movements (p<0.05).  Conclusion: The findings of this study highlight the different physical and physiological demands placed on players in the various sub-disciplines during training and the one-day game. The current study found the major disparity between training and the one-day game was amongst the batsmen.&nbsp

Activation of SGK1 in endometrial epithelial cells in response to PI3K/AKT inhibition impairs embryo implantation

Background: Serum & Glucocorticoid Regulated Kinase 1 (SGK1) plays a fundamental role in ion and solute transport processes in epithelia. In the endometrium, down-regulation of SGK1 during the window of receptivity facilitates embryo implantation whereas expression of a constitutively active mutant in the murine uterus blocks implantation. Methods/Results: Here, we report that treatment of endometrial epithelial cells with specific inhibitors of the phosphoinositide 3-kinase (PI3K)/AKT activity pathway results in reciprocal activation of SGK1. Flushing of the uterine lumen of mice with a cell permeable, substrate competitive phosphatidylinositol analogue that inhibits AKT activation (AKT inhibitor III) resulted in Sgk1 phosphorylation, down-regulation of the E3 ubiquitin-protein ligase Nedd4-2, and increased expression of epithelial Na+ channels (ENaC). Furthermore, exposure of the uterine lumen to AKT inhibitor III prior to embryo transfer induced a spectrum of early pregnancy defects, ranging from implantation failure to aberrant spacing of implantation sites. Conclusion: Taken together, our data indicate that the balanced activities of two related serine/threonine kinases, AKT and SGK1, critically govern the implantation process

Genesis and pathogenesis of the 1918 pandemic H1N1 influenza A virus

The source, timing, and geographical origin of the 1918–1920 pandemic influenza A virus have remained tenaciously obscure for nearly a century, as have the reasons for its unusual severity among young adults. Here, we reconstruct the origins of the pandemic virus and the classic swine influenza and (postpandemic) seasonal H1N1 lineages using a host-specific molecular clock approach that is demonstrably more accurate than previous methods. Our results suggest that the 1918 pandemic virus originated shortly before 1918 when a human H1 virus, which we infer emerged before ∼1907, acquired avian N1 neuraminidase and internal protein genes. We find that the resulting pandemic virus jumped directly to swine but was likely displaced in humans by ∼1922 by a reassortant with an antigenically distinct H1 HA. Hence, although the swine lineage was a direct descendent of the pandemic virus, the post-1918 seasonal H1N1 lineage evidently was not, at least for HA. These findings help resolve several seemingly disparate observations from 20th century influenza epidemiology, seroarcheology, and immunology. The phylogenetic results, combined with these other lines of evidence, suggest that the highmortality in 1918 among adults aged ∼20 to ∼40 y may have been due primarily to their childhood exposure to a doubly heterosubtypic putative H3N8 virus, which we estimate circulated from ∼1889–1900. All other age groups (except immunologically naive infants) were likely partially protected by childhood exposure to N1 and/or H1-related antigens. Similar processes may underlie age-specific mortality differences between seasonal H1N1 vs. H3N2 and human H5N1 vs. H7N9 infections