2,414 research outputs found
Battleground Southeast Asia
Southeast Asia, while still a reservoir of goodwill for the US, has in recent years come increasingly under China's umbrella. In this Strategic Update, Charles Dunst analyzes China's expansion there, discusses Southeast Asians' American predeliction, and offers steps the US can take to "win back" the region
Systematic characterization of Rab GTPase cell type expression and subcellular localization in Drosophila melanogaster
The Rab family of small GTPases orchestrates intracellular endomembrane transport through the recruitment of diverse effector proteins. Since its first discovery in 1987, almost 70 Rab proteins have been identified in humans to date and their perturbed function is implicated in several hereditary and acquired diseases.
In this Ph.D. thesis, I systematically characterize cell type expression and subcellular localization of all Rab proteins present in Drosophila melanogaster utilizing a genetic resource that represents a major advance for studying membrane trafficking in vivo: the ’Drosophila YRab library’. This collection comprises 27 different D. melanogaster knock-in lines that harbor YFPMyc fusions to each Rab protein, referred to as YRab.
For each YRab, I present a comprehensive data set of quantitative and qualitative expression profiles across six larval and adult tissues that include 23 annotated cell types. The whole image data set, along with its annotations, is publicly accessible through the FLYtRAB database that links to CATMAID for online browsing of tissues.
I exploit this data set to address basic cell biological questions. i) How do differentiating cells reorganize their transport machinery to perform cell type-specific functions? My data indicates that qualitative and quantitative changes in YRab protein expression facilitate the functional specialization of differentiated cells. I show that about half of the YRab complement is ubiquitously expressed across D. melanogaster tissues, while others are missing from some cell types or reflect strongly restricted cell type expression, e.g. in the nervous system. I also depict that relative YRab expression levels change as cells differentiate. ii) Are specific Rab proteins dedicated to apical or basolateral protein transport in all epithelia? My data suggests that the endomembrane architecture reflects specific tasks performed by particular epithelial tissues, rather than a generalized apicobasal organization. I demonstrate that there is no single YRab that is similarly polarized in all epithelia. Rather, different epithelial tissues dynamically polarize the subcellular localization of many YRab compartments, producing membrane trafficking architectures that are tissue- and stage-specific.
I further discuss YRab cell type expression and subcellular localization in the context of Rab family evolution. I report that the conservation of YRab protein expression across D. melanogaster cell types reflects their evolutionary conservation in eukaryotes. In addition, my data supports the assumption that the flexible deployment of an expanded Rab family triggered cell differentiation in metazoans.
The FLYtRAB database and the ’Drosophila Rab Library’ are complementary resources that facilitate functional predictions based on YRab cell type expression and subcellular localization, and to subsequently test them by genetic loss-of-function experiments. I demonstrate the power of this approach by revealing new and redundant functions for Rab23 and Rab35 in wing vein patterning.
My data collectively highlight that in vivo studies of endomembrane transport pathways in different D. melanogaster cell types is a valuable approach to elucidate functions of Rab family proteins and their potential implications for human disease
Book review: The war on the Uyghurs: China’s campaign against Xinjiang’s Muslims by Sean R. Roberts
In The War on the Uyghurs: China’s Campaign Against Xinjiang’s Muslims, Sean R. Roberts offers a new account exploring how the US-led Global War on Terror has been used by China as a cover for the persecution of the predominantly Muslim Uyghur population. Giving a voice to the Uyghurs themselves and providing detail that only an expert can offer, this book is an empathetic and deeply informative work for those hoping to understand the humanitarian crisis in Xinjiang, writes Charles Dunst. The War on the Uyghurs: China’s Campaign Against Xinjiang’s Muslims. Sean R. Roberts. Manchester University Press. 2020
A meta-analytic investigation of the relationships between different dimensions of family strengths and personal and family well-being
Objective: Evaluate the relationships between five family strengths dimensions (commitment, communication, cohesion, coping & competence) and personal and family well-being. Background: Noted family strengths experts contend that families who describe themselves as strong share a number of broad qualities or traits. Family strengths are viewed as internal resources that are hypothesized to be related to enhanced personal and family well-being. Method: Meta-analysis was used to determine the effect sizes between different family strengths dimensions and both parent and family well-being. The meta-analysis included 14 studies (N = 3,491 participants) conducted in 10 countries. The focus of analysis was the sizes of effects between each family strengths dimension and both parent and family well-being and whether the strengths of relations between family strengths and well-being differed for each family strength dimension. Results: Publication bias analysis indicated no differences in the sizes of effects for peer-reviewed and non-peer-reviewed research reports. Each of the family strengths dimensions was significantly related to both personal and family well-being. The size of effect for the relationship between family strengths and family well-being was larger than that for personal well-being. The between type of family strengths dimension analyses showed that the size of effect between family competence and personal and family well-being was smaller than those for each of the other family strengths dimensions. Conclusion: The findings support the hypothesis that different dimensions of family strengths are important predictors of personal and family well-being. Results also indicated the strength of the relationship between family strengths and well-being differed between the five family strengths dimensions
Child studies through the lens of applied family social systems theory
The foundations of an applied family social systems theory for explaining the multiple determinants of child well-being, learning, and development, parenting beliefs, behavior and practices, and family well-being are described. The theory is derived from tenets of Bronfenbrenner’s ecological systems theory and other social, family, and contextualized theories. The applied theory was used to develop an activity setting model of young children’s everyday learning opportunities and a family systems intervention practices model for ensuring parents and other caregivers have the time and psychological energy to provide young children with development-instigating and development-enhancing learning opportunities in the contexts of everyday family and community life. Results from three different lines of research are described which provide support for the applied systems model and the two associated intervention models. Results showed that different child characteristics, setting characteristics, parenting behavior and practices, family and social systems variables, and practitioner measures were empirically related to variations in child, parent, and family outcomes. There were also discernable pathways of influence between family systems intervention model practices, parenting practices, and child outcomes mediated by parent self-efficacy beliefs and parent well-being. The contributions of the theory, models, and research findings to child studies are described.Neste artigo descrevem-se os fundamentos de uma teoria aplicada dos sistemas sociais da família para explicar as múltiplas variáveis do bem-estar infantil, da aprendizagem e do desenvolvimento, das crenças parentais, do comportamento e das práticas e bem-estar familiar. A teoria deriva de princípios dos sistemas ecológicos de Bronfenbrenner e outras teorias sociais, familiares e contextualizadas. A teoria aplicada foi usada para desenvolver um modelo de configuração de atividades das oportunidades de aprendizagem quotidianas de crianças pequenas e um modelo de práticas de intervenção de sistemas familiares para garantir que os pais e outros cuidadores tenham tempo e energia psicológica para fornecer às crianças oportunidades de aprendizagem que estimulam e melhoram o seu desenvolvimento nos contextos da vida quotidiana da família e da comunidade. O artigo inclui resultados de três diferentes linhas de investigação que sustentam o modelo de sistemas aplicados e os dois modelos de intervenção associados. Os resultados mostram que as diferentes características da criança, assim como as do meio, os comportamento e as práticas parentais, as variáveis dos sistemas familiares e sociais e as ações do profissional estão empiricamente relacionados com as variações nos resultados da criança, dos pais e da família. Foram igualmente identificadas vias de influência entre as práticas do modelo de intervenção dos sistemas familiares, as práticas parentais e os resultados da criança mediados pelas conceções de autoeficácia dos pais e pelo seu bem-estar. Descrevem-se as contribuições da teoria, dos modelos e dos resultados da investigação para os Estudos da Criança
Caregivers' experiences with the new family‐centred paediatric physiotherapy programme COPCA : a qualitative study
Caregivers' experiences during early intervention of their infant with special needs have consequences for their participation in the intervention. Hence, it is vital to understand caregivers' view. This study explored caregivers' experiences with the family-centred early intervention programme "COPing with and CAring for infants with special needs" (COPCA)
A Novel Approach of Modelling and Predicting Track Cycling Sprint Performance
In cycling, performance models are used to investigate factors that determine performance and to optimise competition results. We present an innovative and easily applicable mathematical model describing time-resolved approaches for both the physical aspects of tractional resistance and the physiological side of propelling force generated by muscular activity and test its validity to reproduce and forecast time trials in track cycling. Six elite track cyclists completed a special preparation and two sprint time trials in an official velodrome under continuous measurement of crank force and cadence. Fatigue-free force-velocity profiles were calculated, and their fatigue-induced changes were determined by non-linear regression analysis using a monoexponential equation at a constant slope. Model parameters were calibrated based on pre-exercise performance testing and the first of the two time-trials and then used to predict the performance of the second sprint. Measured values for power output and cycling velocity were compared to the modelled data. The modelled results were highly correlated to the measured values (R2>0.99) without any difference between runs (p>0.05; d<0.1). Our mathematical model can accurately describe sprint track cycling time trial performance. It is simple enough to be used in practice yet sufficiently accurate to predict highly dynamic maximal sprint performances. It can be employed for the evaluation of completed runs, to forecast expected results with different setups, and to study various contributing factors and quantify their effect on sprint cycling performance
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