79,461 research outputs found

    Turing Pattern Formation in Reaction-Cross-Diffusion Systems with a Bilayer Geometry

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    Conditions for self-organisation via Turing’s mechanism in biological systems represented by reaction-diffusion or reaction-cross-diffusion models have been extensively studied. Nonetheless, the impact of tissue stratification in such systems is under-explored, despite its ubiquity in the context of a thin epithelium overlying connective tissue, for instance the epidermis and underlying dermal mesenchyme of embryonic skin. In particular, each layer can be subject to extensively different biochemical reactions and transport processes, with chemotaxis - a special case of cross-diffusion - often present in the mesenchyme, contrasting the solely molecular transport typically found in the epidermal layer. We study Turing patterning conditions for a class of reaction-cross-diffusion systems in bilayered regions, with a thin upper layer and coupled by a linear transport law. In particular, the role of differential transport through the interface is explored together with the presence of asymmetry between the homogeneous equilibria of the two layers. A linear stability analysis is carried out around a spatially homogeneous equilibrium state in the asymptotic limit of weak and strong coupling strengths, where quantitative approximations of the bifurcation curve can be computed. Our theoretical findings, for an arbitrary number of reacting species, reveal quantitative Turing conditions, highlighting when the coupling mechanism between the layered regions can either trigger patterning or stabilize a spatially homogeneous equilibrium regardless of the independent patterning state of each layer. We support our theoretical results through direct numerical simulations, and provide an open source code to explore such systems further

    ‘They are doing it because they love it’: U.S. and English fan perceptions of women footballers as ‘role models’

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    We draw from 102 interviews with American and English adults who attended the 2019 Women’s World Cup to examine how fans perceive women footballers as ‘role models’, with attention to the operations of gender ideology. Despite the recent professionalization and commercialization of women’s football, there is a dearth of research on fan perspectives of players as role models. Our findings show that most fans perceive role modelling as women’s accessibility and authenticity in interaction. Fans naturalize women’s often uncompensated labor as role models through a supposed love for their sport and desire to see its future growth, endorsing a gender essentialist view of women as notably caring and giving in comparison to men. However, a minority of fans embrace a more critical view by identifying role modelling as an expectation placed disproportionately on women within an already unequal resource environment. We conclude that role modelling is a gendered expectation for elite women footballers and that fans can be a source of pressure towards its enactment

    An ALMA Spectroscopic Survey of the Brightest Submillimeter Galaxies in the SCUBA-2-COSMOS Field (AS2COSPEC): Physical Properties of z = 2–5 Ultra- and Hyperluminous Infrared Galaxies

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    We report the physical properties of the 18 brightest (S 870 ÎŒm = 12.4–19.2 mJy) and not strongly lensed 870 ÎŒm–selected dusty star-forming galaxies (DSFGs), also known as submillimeter galaxies (SMGs), in the COSMOS field. This sample is part of an ALMA band 3 spectroscopic survey (AS2COSPEC), and spectroscopic redshifts are measured in 17 of them at z = 2–5. We perform spectral energy distribution analyses and deduce a median total infrared luminosity of L IR = (1.3 ± 0.1) × 1013 L ⊙, infrared-based star formation rate (SFR) of SFRIR = 1390 ± 150 M ⊙ yr−1, stellar mass of M * = (1.4 ± 0.6) × 1011 M ⊙, dust mass of M dust = (3.7 ± 0.5) × 109 M ⊙, and molecular gas mass of M gas = (α CO/0.8)(1.2 ± 0.1) × 1011 M ⊙, suggesting that they are one of the most massive, ISM-enriched, and actively star-forming systems at z = 2–5. In addition, compared to less massive and less active galaxies at similar epochs, SMGs have comparable gas fractions; however, they have a much shorter depletion time, possibly caused by more active dynamical interactions. We determine a median dust emissivity index of ÎČ = 2.1 ± 0.1 for our sample, and by combining our results with those from other DSFG samples, we find no correlation of ÎČ with redshift or infrared luminosity, indicating similar dust grain compositions across cosmic time for infrared luminous galaxies. We also find that AS2COSPEC SMGs have one of the highest dust-to-stellar mass ratios, with a median of 0.02 ± 0.01, significantly higher than model predictions, possibly due to too-strong active galactic nucleus feedback implemented in the model. Finally, our complete and uniform survey enables us to put constraints on the most massive end of the dust and molecular gas mass functions

    Harping on patriotism: female education meets OrlĂ©anist ambition in Jean-Antoine-ThĂ©odore Giroust’s The Harp Lesson (1791)

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    One of the largest and most striking submissions to the 1791 Salon, The Harp Lesson by Jean-Antoine-ThĂ©odore Giroust was an ambitious but spectacularly ill-timed intervention in revolutionary politics. It emerged from FĂ©licitĂ© de Genlis’ remarkable educational project for the children of the duc d’OrlĂ©ans, especially Princess AdĂ©laĂŻde, which mixed bold ideas about gender and civic virtue with specific political ambition. This article situates the painting within the experimental politics and sentimental crises of the OrlĂ©ans household. It argues that Giroust, an intimate of this household, sought to exemplify some of Genlis’ boldest claims for the capacities and potential of the royal children in her care, especially at the expense of their biological mother. It demonstrates how Giroust engaged with the visual languages of recent Salon painting to create a domestic scene of female accomplishment that was also freighted with national purpose. The failure of the painting to resonate with the public illuminates the desperate gamble of different figures in the OrlĂ©anist camp as well as the unfulfilled possibilities of summer 1791

    Unified framework for choice-based facility location problem

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    The Effects of Lockdown during the COVID-19 Pandemic on Fetal Movement Profiles

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    Dead and dying bodies

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    Training to be a Primary School Teacher: The CCF and Beyond

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    The Impact of Intersectional Racial and Gender Biases on Minority Female Leadership Over Two Centuries

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    This study scrutinizes the enduring effects of racial and gender biases that contribute to the consistent underrepresentation of minority women in leadership roles within American private, public, and third sector organizations. We adopt a cultural situatedness approach, merging psychological schema theory with sociological intersectionality theory, to evaluate the enduring implications of these biases on female leadership development. Our examination is concentrated on Black female leaders, employing an extensive analysis of leadership rhetoric data spanning 200 years across the aforementioned sectors. We shed light on the continued scarcity of minority female representation in leadership roles, highlighting the role of intersectionality dynamics. Despite Black female leaders frequently embracing higher risks to counter intersectional invisibility compared to their White counterparts, their aspirations are not realized and problems not solved generation after generation, forcing Black female leaders to concentrate on the same issues for dozens and, sometimes, hundreds of years. Our findings suggest that the compound influence of racial and gender biases hinders the advancement of minority female leadership by perpetuating stereotypical behavioral schemas, leading to persistent discriminatory outcomes. We argue for the necessity of organizations to initiate a cultural transformation that fosters positive experiences for future generations of female leaders, recommending a shift in focus from improving outcomes for specific groups to creating an inclusive leadership culture

    How founders harness tensions in hybrid venture development

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    Although the simultaneous presence of multiple ambitions is inherent in hybrid venturing, pursuing social and/or environmental missions while securing commercial viability can generate ambivalence amongst stakeholders. In this study, we draw on the notion of ‘holism’ to show how venture founders both embrace tensioned ambitions and sustain hybridity during critical venture development phases. Based on six years of data on The People’s Supermarket in the UK, we identify three distinct practices––fantasising, bartering, and conjuring––used by founders to harness tensions productively, without compromising their venture’s multiple ambitions. These practices demonstrate founders’ ability to maintain a venture’s hybrid nature throughout the ideation, organisational, and scale-up phases, thereby shedding light on the application of ‘holism’ within the realm of hybrid venturing
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