206 research outputs found

    Role of Pumilio proteins during neural crest development

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    The neural crest (NC) is a multipotent stem cell‐like population, unique to vertebrates, that is characterized by its migratory behavior and broad ability to differentiate into many diverse derivatives including elements of the cardiovascular system, bone and cartilage of the face, the peripheral nervous system, and melanocytes. After neurulation, neural crest cells (NCC) delaminate, undergo EMT from the neural tube, and migrate both individually and collectively as chains. Various developmental diseases, including craniofacial abnormalities and neural crest‐derived cancers such as melanoma arise due to improper development of NC. While there has been much focus on transcriptional mechanisms in regulation of neural crest specification, the process of cell migration involves rapid changes that likely require post‐transcriptional regulation. In order to uncover novel proteins that might influence NC development, we have performed transcriptional profiling of migrating neural crest cells and found >300 genes that are upregulated in the migrating crest including the sequence specific RNA binding protein Pumilio1 (PUM1). PUM proteins are evolutionarily conserved translational regulators that play essential roles during germline development in both invertebrates and vertebrates. Here, we showed that pum1 and pum2 mRNA is present in both premigratory and migratory NC. Pum loss of function resulted in depletion of NC cells migrating neural tube. Conversely, over expression led to an increase in numbers of migrating cells. This led us to think about the potential role of PUM proteins in modulating the specification of NC cells. To identify potential NC targets of PUM, we carried out a bioinformatics screen focusing on NC relevant genes across multiple species that possessed a Pumilio Response Element (PRE) in their 3'UTR region. The PRE element, 5’‐UGUANAUA‐3,’ is a highly conserved consensus that PUM proteins recognize in the 3’UTRs of their targets. Interestingly, several neural crest markers possess a PRE, thus representing potential targets regulated by Pumilio during NC development. Investigation of the specific mechanism whereby PUM proteins regulate NC development is currently in progress

    Nanoscale resolution of microbial fiber degradation in action

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    The lives of microbes unfold at the micron scale, and their molecular machineries operate at the nanoscale. Their study at these resolutions is key toward achieving a better understanding of their ecology. We focus on cellulose degradation of the canonical Clostridium thermocellum system to comprehend how microbes build and use their cellulosomal machinery at these nanometer scales. Degradation of cellulose, the most abundant organic polymer on Earth, is instrumental to the global carbon cycle. We reveal that bacterial cells form 'cellulosome capsules' driven by catalytic product-dependent dynamics, which can increase the rate of hydrolysis. Biosynthesis of this energetically costly machinery and cell growth are decoupled at the single-cell level, hinting at a division-of-labor strategy through phenotypic heterogeneity. This novel observation highlights intrapopulation interactions as key to understanding rates of fiber degradation

    Spatial variability of precipitation regimes over Turkey

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    Turkish annual precipitation regimes are analysed to provide large-scale perspective and redefine precipitation regions. Monthly total precipitation data are employed for 107 stations (1963–2002). Precipitation regime shape (seasonality) and magnitude (size) are classified using a novel multivariate methodology. Six shape and five magnitude classes are identified, which exhibit clear spatial structure. A composite (shape and magnitude) regime classification reveals dominant controls on spatial variability of precipitation. Intra-annual timing and magnitude of precipitation is highly variable due to seasonal shifts in Polar and Subtropical zones and physiographic factors. Nonetheless, the classification methodology is shown to be a powerful tool that identifies physically-interpretable precipitation regions: (1) coastal regimes for Marmara, coastal Aegean, Mediterranean and Black Sea; (2) transitional regimes in continental Aegean and Southeast Anatolia; and (3) inland regimes across central and Eastern Anatolia. This research has practical implications for understanding water resources, which are under ever growing pressure in Turkey

    Fumonisin B1 Toxicity in Grower-Finisher Pigs: A Comparative Analysis of Genetically Engineered Bt Corn and non-Bt Corn by Using Quantitative Dietary Exposure Assessment Modeling

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    In this study, we investigate the long-term exposure (20 weeks) to fumonisin B1 (FB1) in grower-finisher pigs by conducting a quantitative exposure assessment (QEA). Our analytical approach involved both deterministic and semi-stochastic modeling for dietary comparative analyses of FB1 exposures originating from genetically engineered Bacillus thuringiensis (Bt)-corn, conventional non-Bt corn and distiller’s dried grains with solubles (DDGS) derived from Bt and/or non-Bt corn. Results from both deterministic and semi-stochastic demonstrated a distinct difference of FB1 toxicity in feed between Bt corn and non-Bt corn. Semi-stochastic results predicted the lowest FB1 exposure for Bt grain with a mean of 1.5 mg FB1/kg diet and the highest FB1 exposure for a diet consisting of non-Bt grain and non-Bt DDGS with a mean of 7.87 mg FB1/kg diet; the chronic toxicological incipient level of concern is 1.0 mg of FB1/kg of diet. Deterministic results closely mirrored but tended to slightly under predict the mean result for the semi-stochastic analysis. This novel comparative QEA model reveals that diet scenarios where the source of grain is derived from Bt corn presents less potential to induce FB1 toxicity than diets containing non-Bt corn

    Acute myocardial infarction, associated with the use of a synthetic adamantyl-cannabinoid: a case report

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    BACKGROUND: “Legal highs” are novel psychoactive substances that have evaded statutory control. Synthetic cannabinoid compounds with adamantane moieties have recently been identified, which have high potency at target receptors and are undetectable on conventional toxicology testing. However, little is known about any harmful effects, and their potential to cause serious ill health. We describe a case of myocardial infarction following the use of this class of drug. CASE PRESENTATION: We report the case of a 39-year-old man admitted after an out-of-hospital cardiac arrest, in whom ECG and elevated cardiac enzymes confirmed ST-elevation myocardial infarction. Normal coronary perfusion was restored after thrombectomy and coronary artery stenting. In the hours preceding his admission, the patient is known to have consumed the legal high product “Black Mamba”. Subsequent urine testing confirmed the presence of an adamantyl-group synthetic cannabinoid, whilst cannabis, cocaine, amphetamines and other drugs of abuse were not detected. CONCLUSION: The use of legal highs is being increasingly recognised, but the chemical compositions and physiological effects of these drugs are poorly characterised and are continually changing. Synthetic cannabinoids, rarely identified on toxicological testing, can be linked to serious adverse cardiovascular events. This case highlights the importance of testing for novel psychoactive compounds, and recognising their potential to cause life-threatening conditions

    Stenosis and Aneurysm of Coronary Arteries in A Patient with Behcet’s Disease

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    Coronary artery disease is extremely rare in patients with Behçet’s disease. We report the case of a patient with a history of Behçet’s disease who was admitted in our hospital with instable angina pectoris. The patient’s electrocardiogram was normal. Coronary angiography revealed aneurysm of the distal right coronary artery with a tight stenosis of the proximal part of the posterolateral branch. These two conditions were initially treated with immunosuppressive treatment. Three years later coronary angiography showed a total occlusion of the right coronary artery treated with medical therapy. More than fourteen cases of coronary involvement were reported in the literature but the etiopathogeny and the treatment are yet unknow

    Universities’ pursuit of inclusion and its effects on professional staff: the case of the United Kingdom

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    This paper explores the proliferation of non-academic professionals as a cultural response to universities’ mission of inclusion. Departing from a neo-institutionalist perspective, the author argues that the diffusion of highly rationalised models of institutional action shapes universities as formal organisations who engage with new levels of professional expertise in the pursuit of goals and missions. The United Kingdom (UK) offers an illustrative example, the emergence of statutory equality duties on public institutions (race equality duty 2001, disability equality duty 2006 and gender equality duty 2007) nurturing an image of universities as strategic for the pursuit of demographic inclusion. Using yearly longitudinal data on 109 UK universities from 2003 to 2011, the author shows that universities increase their professional staff in catering for demographic inclusion in terms of ethnicity and disability, revealing highly rationalised institutional responses to the aforementioned equality duties. The findings contribute to the neo-institutionalist literature drawing attention to the transformation of universities into organisational actors (i.e. highly integrated entities, strategically oriented towards the pursuit of formally articulated goals and targets), which contrasts with traditional conceptions of the university as an institution with a taken-for-granted societal role and loosely defined organisational backbone. The findings provide the impetuous for further empirical research into the role of professional staff as universities assimilate new goals and missions

    Reassembling difference? Rethinking inclusion through/as embodied ethics

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    This paper considers inclusion through the lens of embodied ethics. It does so by connecting feminist writing on recognition, ethics and embodiment to recent examples of political activism as instances of recognition-based organizing. In making these connections, the paper draws on insights from Judith Butler’s recent writing on the ethics and politics of assembly in order to re-think how inclusion might be understood and practiced. The paper has three inter-related aims: (i) to emphasize the importance of a critical reconsideration of the ethics and politics of inclusion given, on the one hand, its positioning as an organizational ‘good’ and on the other, the conditions attached to it; (ii) to develop a critique of inclusion, drawing on insights from recent feminist thinking on relational ethics, and (iii) to connect this theoretical critique of inclusion, re-considered here through the lens of embodied ethics, to assembly as a form of feminist activism. Each of these aims underpins the theoretical and empirical discussion developed in the paper, specifically its focus on the relationship between embodied ethics, the interplay between theory and practice, and a politics of assembly as the basis for a critical reconsideration of inclusion

    Antecedents and Outcomes of Managing Diversity in a UK Context: Test of a Mediation Model

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    Extant research on diversity management has primarily examined the main effects of diversity management practices on outcomes from an organizational perspective. Meta-analysis in this field corroborates the conclusion that this approach is unable to account for the outcomes of diversity management effectively. The current study extends the literature by examining organizational antecedents of diversity management practices (DMP). This study also examines the mediating influences of perception of overall justice (POJ) and social exchange with organization (SEWO) on the relationships between DMP and work outcomes of career satisfaction and turnover intention. Results of data obtained from a cross section of 191 minority employees in UK revealed: (i) the reasons why organisations adopted and implemented DMP influenced employees’ outcomes of turnover intention and career satisfaction; (ii) the relationship between diversity management and social exchange with organization is mediated by perception of overall justice; (iii) social exchange with organization relates to increased career satisfaction; and (iv) DMP related positively to career satisfaction through perception of overall justice and SEWO

    Stories from the field:Women's networking as gender capital in entrepreneurial ecosystems

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    Women are underrepresented in successful entrepreneurial ecosystems and the creation of women-only entrepreneurial networks has been a widespread policy response. We examine the entrepreneurial ecosystem construct and suggest that it, and the role networks play in entrepreneurial ecosystems, can be analysed in terms of Bourdieu's socio-analysis as field, habitus and capital. Specifically, we develop the notion of gender capital as the skill set associated with femininity or from simply being recognized as feminine. We apply this to the development of women's entrepreneurial networks as a gender capital enhancing initiative. Using data from qualitative interviews with network coordinators and women entrepreneurs we reflect on the extent to which formally established women-only networks generate gender capital for their members and improve their ability to participate in the entrepreneurial ecosystem. The paper concludes by drawing out the implications of our analysis for theory, entrepreneurial practice and economic development policy
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