173 research outputs found

    Setting the stage: social-environmental and motivational predictors of optimal training engagement

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    In this paper, we will firstly explore the central tenets of SDT. Research that has examined the social-environmental and motivation-related correlates of optimal training, performance and health-related engagement through the theoretical lens of SDT will be reviewed. Drawing from SDT-driven work undertaken in educational, sport and dance settings, we will draw conclusions and suggest future directions from a research and applied perspective

    Autonomy support, basic need satisfaction and the optimal functioning of adult male and female sport participants: A test of basic needs theory

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    Grounded in Basic Needs Theory (BNT; Ryan and Deci, American Psychologist, 55, 68–78, 2000a), the present study aimed to: (a) test a theoretically-based model of coach autonomy support, motivational processes and well-/ill being among a sample of adult sport participants, (b) discern which basic psychological need(s) mediate the link between autonomy support and well-/ill-being, and (c) explore gender invariance in the hypothesized model. Five hundred and thirty nine participants (Male = 271;Female = 268; Mage = 22.75) completed a multi-section questionnaire tapping the targeted variables. Structural Equation Modeling (SEM) analysis revealed that coach autonomy support predicted participants’ basic need satisfaction for autonomy, competence and relatedness. In turn, basic need satisfaction predicted greater subjective vitality when engaged in sport. Participants with low levels of autonomy were more susceptible to feeling emotionally and physically exhausted from their sport investment. Autonomy and competence partially mediated the path from autonomy support to subjective vitality. Lastly, the results supported partial invariance of the model with respect to gender

    Differential responses of plasmacytoid dendritic cells to influenza virus and distinct viral pathogens.

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    Plasmacytoid dendritic cells (pDCs) are key components of the innate immune response that are capable of synthesizing and rapidly releasing vast amounts of type I interferons (IFNs), particularly IFN-α. Here we investigated whether pDCs, often regarded as a mere source of IFN, discriminate between various functionally discrete stimuli and to what extent this reflects differences in pDC responses other than IFN-α release. To examine the ability of pDCs to differentially respond to various doses of intact and infectious HIV, hepatitis C virus, and H1N1 influenza virus, whole-genome gene expression analysis, enzyme-linked immunosorbent assays, and flow cytometry were used to investigate pDC responses at the transcriptional, protein, and cellular levels. Our data demonstrate that pDCs respond differentially to various viral stimuli with significant changes in gene expression, including those involved in pDC activation, migration, viral endocytosis, survival, or apoptosis. In some cases, the expression of these genes was induced even at levels comparable to that of IFN-α. Interestingly, we also found that depending on the viral entity and the viral titer used for stimulation, induction of IFN-α gene expression and the actual release of IFN-α are not necessarily temporally coordinated. In addition, our data suggest that high-titer influenza A (H1N1) virus infection can stimulate rapid pDC apoptosis. IMPORTANCE Plasmacytoid dendritic cells (pDCs) are key players in the viral immune response. With the host response to viral infection being dependent on specific virus characteristics, a thorough examination and comparison of pDC responses to various viruses at various titers is beneficial for the field of virology. Our study illustrates that pDC infection with influenza virus, HIV, or hepatitis C virus results in a unique and differential response to each virus. These results have implications for future virology research, vaccine development, and virology as a whole

    A Positive Feedback Synapse from Retinal Horizontal Cells to Cone Photoreceptors

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    Cone photoreceptors and horizontal cells (HCs) have a reciprocal synapse that underlies lateral inhibition and establishes the antagonistic center-surround organization of the visual system. Cones transmit to HCs through an excitatory synapse and HCs feed back to cones through an inhibitory synapse. Here we report that HCs also transmit to cone terminals a positive feedback signal that elevates intracellular Ca2+ and accelerates neurotransmitter release. Positive and negative feedback are both initiated by AMPA receptors on HCs, but positive feedback appears to be mediated by a change in HC Ca2+, whereas negative feedback is mediated by a change in HC membrane potential. Local uncaging of AMPA receptor agonists suggests that positive feedback is spatially constrained to active HC-cone synapses, whereas the negative feedback signal spreads through HCs to affect release from surrounding cones. By locally offsetting the effects of negative feedback, positive feedback may amplify photoreceptor synaptic release without sacrificing HC-mediated contrast enhancement

    Measuring psychological need states in sport: Theoretical considerations and a new measure

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    © 2019 Elsevier Ltd Objectives: Research guided by Self-determination Theory (Deci & Ryan, 1985; Ryan & Deci, 2017) has repeatedly demonstrated the importance of focusing on both the bright (satisfaction) and dark (frustration) sides of the three basic psychological needs. Recently, researchers have also argued for the utility of assessing a third need state, that of “unfulfillment”. In this paper, we outline an effort to develop and provide initial validity evidence for scores of a new multidimensional and sport-specific measure, the Psychological Need States in Sport-Scale (PNSS-S), to assess the satisfaction, frustration, and unfulfillment of all three needs. Method: In Study 1, we developed 46 candidate items, and tested evidence for the factorial structure of the responses to the newly developed items, internal consistency and discriminant validity of the subscale scores. Following refinement, the replication of the favored model was tested using an independent sample of athletes in Study 2. Evidence for the nomological network of the subscales of the new measure was also demonstrated in Study 2. Results: Factor models incorporating all three need states showed poor fit with the data. However, following post-hoc modifications, a six-factor model assessing the need states of satisfaction and frustration, separately for autonomy, competence, and relatedness, was found to have good fit to the data. After refinement, the 29-item six-factor model was found to demonstrate good fit, good standardized factor loadings, factor correlations in the expected directions, and acceptable estimates of internal consistency in Study 2. Tests of nomological networks showed that the six need states were significantly predicted by contextual autonomy, competence, and relatedness support/thwarts as expected. Autonomy and competence need satisfaction were significantly associated with engagement; and competence and relatedness need satisfaction were significantly associated with positive affect. In addition, autonomy and competence need frustration were significantly associated with exhaustion and all three need frustration states significantly predicted negative affect. Conclusions: A tripartite conceptualization of the need states was not empirically supported. Nevertheless, the PNSS-S makes a unique contribution to the sport literature, as it represents the first sport-specific measure of six distinct, yet, correlated states of the satisfaction and frustration of autonomy, competence, and relatedness needs

    The trans-contextual model: Perceived learning and performance motivational climates as analogues of perceived autonomy support

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    The trans-contextual model of motivation (TCM) proposes that perceived autonomy support in physical education (PE) predicts autonomous motivation within this context, which, in turn, is related to autonomous motivation and physical activity in leisure-time. According to achievement goal theory perceptions of learning and performance, motivational climate in PE can also affect autonomous motivation in PE. The purpose of the present study was to examine the influence of an integrated approach of perceptions of motivational climate in PE by incorporating aspects of perceptions of motivational climate from achievement goal frameworks on autonomous motivation in PE within the TCM. High school students (N = 274) completed self-report measures of perceived autonomy support, perceived learning, and performance motivational climate and autonomous motivation in PE. Follow-up measures of autonomous motivation in a leisure-time context were taken along with measures of attitudes, subjective norms, perceived behavioural control and intentions from the theory of planned behaviour 1 week later. Self-reported physical activity behaviour was measured 5 weeks later. The results of the path analyses indicated that perceived learning climate was the strongest predictor of autonomous motivation in PE and leisure-time contexts and mediated the effect of perceived autonomy support on autonomous motivation in PE. Perceived performance climate showed no significant effect on autonomous motivation in PE and leisure-time. Results also confirmed the premises of TCM regarding the effect of autonomous motivation in leisure-time on leisure-time physical activity and the mediating role of the planned behaviour theory variables

    Loss-of-function mutations in the X-linked biglycan gene cause a severe syndromic form of thoracic aortic aneurysms and dissections.

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    Thoracic aortic aneurysm and dissection (TAAD) is typically inherited in an autosomal dominant manner, but rare X-linked families have been described. So far, the only known X-linked gene is FLNA, which is associated with the periventricular nodular heterotopia type of Ehlers-Danlos syndrome. However, mutations in this gene explain only a small number of X-linked TAAD families. We performed targeted resequencing of 368 candidate genes in a cohort of 11 molecularly unexplained Marfan probands. Subsequently, Sanger sequencing of BGN in 360 male and 155 female molecularly unexplained TAAD probands was performed. We found five individuals with loss-of-function mutations in BGN encoding the small leucine-rich proteoglycan biglycan. The clinical phenotype is characterized by early-onset aortic aneurysm and dissection. Other recurrent findings include hypertelorism, pectus deformity, joint hypermobility, contractures, and mild skeletal dysplasia. Fluorescent staining revealed an increase in TGF-β signaling, evidenced by an increase in nuclear pSMAD2 in the aortic wall. Our results are in line with those of prior reports demonstrating that Bgn-deficient male BALB/cA mice die from aortic rupture. In conclusion, BGN gene defects in humans cause an X-linked syndromic form of severe TAAD that is associated with preservation of elastic fibers and increased TGF-β signaling.Genet Med 19 4, 386-395
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