403 research outputs found

    Retinoic acid influences the timing and scaling of avian wing development

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    A fundamental question in biology is how embryonic development is timed between different species. To address this problem, we compared wing development in the quail and the larger chick. We reveal that pattern formation is faster in the quail as determined by the earlier activation of 5′Hox genes, termination of developmental organizers (Shh and Fgf8), and the laying down of the skeleton (Sox9). Using interspecies tissue grafts, we show that developmental timing can be reset during a critical window of retinoic acid signaling. Accordingly, extending the duration of retinoic acid signaling switches developmental timing between the quail and the chick and the chick and the larger turkey. However, the incremental growth rate is comparable between all three species, suggesting that the pace of development primarily governs differences in the expansion of the skeletal pattern. The widespread distribution of retinoic acid could coordinate developmental timing throughout the embryo

    Perturbed cholesterol and vesicular trafficking associated with dengue blocking in Wolbachia-infected Aedes aegypti cells

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    Wolbachia are intracellular maternally inherited bacteria that can spread through insect populations and block virus transmission by mosquitoes, providing an important approach to dengue control. To better understand the mechanisms of virus inhibition, we here perform proteomic quantification of the effects of Wolbachia in Aedes aegypti mosquito cells and midgut. Perturbations are observed in vesicular trafficking, lipid metabolism and in the endoplasmic reticulum that could impact viral entry and replication. Wolbachia-infected cells display a differential cholesterol profile, including elevated levels of esterified cholesterol, that is consistent with perturbed intracellular cholesterol trafficking. Cyclodextrins have been shown to reverse lipid accumulation defects in cells with disrupted cholesterol homeostasis. Treatment of Wolbachia-infected Ae. aegypti cells with 2-hydroxypropyl-β-cyclodextrin restores dengue replication in Wolbachia-carrying cells, suggesting dengue is inhibited in Wolbachia-infected cells by localised cholesterol accumulation. These results demonstrate parallels between the cellular Wolbachia viral inhibition phenotype and lipid storage genetic disorders

    Is procrastination related to sleep quality? Testing an application of the procrastination-health model

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    Despite a growing body of research on the consequences of procrastination for health and well-being, there is little research focused on testing or explaining the potential links between procrastination and sleep quality. Using the procrastination-health model as our guiding conceptual lens, we addressed this gap by examining how and why trait procrastination may be linked to various dimensions of sleep quality across two student samples. In Study 1, procrastination was associated with feeling unrested, but not sleep disturbance frequency, in a sample of Greek undergraduate students (N = 141). In Study 2, bootstrapping analysis of the indirect effects of procrastination on an index of sleep quality through perceived stress in a sample of Canadian students (N = 339) was significant supporting an extended procrastination-health model view of how chronic self-regulation failure may compromise sleep quality. Given the potential for dynamic and reciprocal relations among procrastination, stress, and sleep quality suggested by the current and other research, the ways in which procrastination may contribute to and be influenced by poor sleep quality warrants further investigation

    Q methodology and a Delphi poll: a useful approach to researching a narrative approach to therapy

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    Q methodology and a Delphi poll combined qualitative and quantitative methods to explore definitions of White and Epston's (1990) narrative approach to therapy among a group of UK practitioners. A Delphi poll was used to generate statements about narrative therapy. The piloting of statements by the Delphi panel identified agreement about theoretical ideas underpinning narrative therapy and certain key practices. A wider group of practitioners ranked the statements in a Q sort and made qualitative comments about their sorting. Quantitative methods (principal components analysis) were used to extract eight accounts of narrative therapy, five of which are qualitatively analysed in this paper. Agreement and differences were identified across a range of issues, including the social construction of narratives, privileging a political stance or narrative techniques and the relationship with other therapies, specifically systemic psychotherapy. Q methodology, combined with the Delphi poll, was a unique and innovative feature of this study

    The Social Construction of Conspiracy Beliefs: A Q-Methodology Study of How Ordinary People DefineThem and Judge Their Plausibility

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    Little is known about ordinary people’s understandings of conspiracy beliefs and how these understandings relate to the perspectives of researchers and scholars. Working within a social constructionist epistemological framework, we conducted a Q-methodology study aiming to identify a range of lay perspectives on two key topics: the defining features of conspiracy beliefs; and aspects considered important in judging their plausibility. Fifty-six people (32 men and 24 women), recruited via regional UK Facebook groups, sorted their agreement with a set of statements on each of the two topics. A principal component analysis, followed by varimax rotation, was performed on each data set. Five accounts about the defining features of conspiracy beliefs were identified: that they are false, illogical and harmful; that they are forms of political critique; that there are varied types; that they are entertaining but ineffectual; and that they are held by a self-reinforcing minority. Four accounts about their evaluation were identified: conventional realist criteria; the importance of personal judgement; skeptical realism; and the assessment of critical thinking. The findings are discussed in the context of the literature and limitations of the study are considered. Implications for research and educational and policy interventions are outlined

    A Pluralistic Theory of Wordhood

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    What are words and how should we individuate them? There are two main answers on the philosophical market. For some, words are bundles of structural-functional features defining a unique performance profile. For others, words are non-eternal continuants individuated by their causal-historical ancestry. These conceptions offer competing views of the nature of words, and it seems natural to assume that at most one of them can capture the essence of wordhood. This paper makes a case for pluralism about wordhood: the view that there is a plurality of acceptable conceptions of the nature of words, none of which is uniquely entitled to inform us as to what wordhood consists in

    Exploring the psychological rewards of a familiar semirural landscape: connecting to local nature through a mindful approach

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    This study analyses a 53,000 word diary of a year engaging with nature through over 200 trips to a semi-rural landscape. Thematic analysis revealed two themes; the transition from observer to nature connectedness and the ways in which the natural environment was experienced once a connection was made. These themes are discussed in relation to theories that seek to explain the positive effect of nature and nature connectedness. The findings are important as they suggest that repeated engagement with local semi-rural countryside can lead to a mindful approach and psychological rewards that do not require travel into the wilderness. The work informs further research into outcomes and processes of nature based interventions such as: trip frequency, duration and diary keeping

    Less Adaptive or More Maladaptive? A Meta-analytic Investigation of Procrastination and Coping

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    Despite the theoretical and empirical accounts of trait procrastination as reflecting avoidance of aversive tasks as a means of mood repair, research documenting its links to coping is scarce and inconsistent. There is also little if any research to date examining whether coping strategies might explain the procrastination-stress relationship. The current research aimed to address these issues by integrating current research on procrastination and coping with our own data into a first meta-analysis of the associations of procrastination with adaptive and maladaptive coping and then testing the potential role of coping for understanding the procrastination-stress relationship. In Study 1, a literature search yielded five published papers and three theses, which were supplemented by seven unpublished data sets comprising 15 samples (N=4357). Meta-analyses revealed that procrastination was positively associated with maladaptive coping (average r=.31) and negatively associated with adaptive coping (average r=-.24). In Study 2, a meta-analysis of the indirect effects through coping across four samples revealed that the average indirect effects for maladaptive but not adaptive coping explained the link between procrastination and stress. These findings expand the nomological network of procrastination and highlight the role of maladaptive coping for understanding procrastinators' stress

    Understanding nursing practice in stroke units: a Q-methodological study.

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    Abstract Purpose: Nurses represent the largest professional group working with stroke-survivors, but there is limited evidence regarding nurses' involvement in post-stroke rehabilitation. The purpose of this study was to identify and explore the perspectives of nurses and other multidisciplinary stroke team members on nurses' practice in stroke rehabilitation. Method: Q-methodological study with 63 multidisciplinary stroke unit team members and semi-structured interviews with 27 stroke unit team members. Results: Irrespective of their professional backgrounds, participants shared the view that nurses can make an active contribution to stroke rehabilitation and integrate rehabilitation principles in routine practice. Training in stroke rehabilitation skills was viewed as fundamental to effective stroke care, but nurses do not routinely receive such training. The view that integrating rehabilitation techniques can only occur when nursing staffing levels were high was rejected. There was also little support for the view that nurses are uniquely placed to co-ordinate care, or that nurses have an independent rehabilitation role. Conclusions: The contribution that nurses with stroke rehabilitation skills can make to effective stroke care was understood. However, realising the potential of nurses as full partners in stroke rehabilitation is unlikely to occur without introduction of structured competency-based multidisciplinary training in rehabilitation skills. Implications for Rehabilitation Multidisciplinary rehabilitation in stroke units is a cornerstone of effective stroke care. Views of stroke unit team members on nurses' involvement in rehabilitation have not been reported previously. Nurses can routinely incorporate rehabilitation principles in their care. Specialist competency-based stroke rehabilitation training needs to be provided for nurses as well as for allied health professionals

    Soft systems methodology: a context within a 50-year retrospective of OR/MS

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    Soft systems methodology (SSM) has been used in the practice of operations research and management science OR/MS) since the early 1970s. In the 1990s, it emerged as a viable academic discipline. Unfortunately, its proponents consider SSM and traditional systems thinking to be mutually exclusive. Despite the differences claimed by SSM proponents between the two, they have been complementary. An extensive sampling of the OR/MS literature over its entire lifetime demonstrates the richness with which the non-SSM literature has been addressing the very same issues as does SSM
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