255 research outputs found

    Male depression risk, psychological distress, and psychotherapy uptake: Validation of the German version of the male depression risk scale

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    Background Screening for depressive disorders in men may be complicated by traditional male role norms. The Male Depression Risk Scale (MDRS) was developed to aid screening for depression in men adhering to traditional male role norms and to facilitate identification of depression in men in general and to promote treatment uptake. Aims Validation of a German version of the MDRS and examination of its potential to predict clinical characteristics. Methods In an anonymous online survey comprising of 1605 participants (male: N = 671; 42%), information was obtained on psychological distress, diagnosed psychological disorders, psychotherapy and psychopharmacological treatment. Additional measures included a German version of the MDRS as further mental-health-related constructs. Results The German version of the MDRS showed good validity and reliability. The previously identified 6-factor structure could be replicated for the German version. Compared to the Patient Health Questionnaire 9, the MDRS showed similar detection performance in identifying men who self-reported psychological distress, psychological disorders, depression, psychotherapy usage, or usage of psychopharmacological therapy. Conclusions The German version of the MDRS shows good psychometric validity and represents a valid screening instrument for the identification of psychological distress specifically in men

    Maximal LpL^p-regularity for stochastic evolution equations

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    We prove maximal LpL^p-regularity for the stochastic evolution equation \{{aligned} dU(t) + A U(t)\, dt& = F(t,U(t))\,dt + B(t,U(t))\,dW_H(t), \qquad t\in [0,T], U(0) & = u_0, {aligned}. under the assumption that AA is a sectorial operator with a bounded HH^\infty-calculus of angle less than 12π\frac12\pi on a space Lq(O,μ)L^q(\mathcal{O},\mu). The driving process WHW_H is a cylindrical Brownian motion in an abstract Hilbert space HH. For p(2,)p\in (2,\infty) and q[2,)q\in [2,\infty) and initial conditions u0u_0 in the real interpolation space \XAp we prove existence of unique strong solution with trajectories in L^p(0,T;\Dom(A))\cap C([0,T];\XAp), provided the non-linearities F:[0,T]\times \Dom(A)\to L^q(\mathcal{O},\mu) and B:[0,T]\times \Dom(A) \to \g(H,\Dom(A^{\frac12})) are of linear growth and Lipschitz continuous in their second variables with small enough Lipschitz constants. Extensions to the case where AA is an adapted operator-valued process are considered as well. Various applications to stochastic partial differential equations are worked out in detail. These include higher-order and time-dependent parabolic equations and the Navier-Stokes equation on a smooth bounded domain \OO\subseteq \R^d with d2d\ge 2. For the latter, the existence of a unique strong local solution with values in (H^{1,q}(\OO))^d is shown.Comment: Accepted for publication in SIAM Journal on Mathematical Analysi

    Non-autonomous stochastic evolution equations and applications to stochastic partial differential equations

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    In this paper we study the following non-autonomous stochastic evolution equation on a UMD Banach space EE with type 2, {equation}\label{eq:SEab}\tag{SE} {{aligned} dU(t) & = (A(t)U(t) + F(t,U(t))) dt + B(t,U(t)) dW_H(t), \quad t\in [0,T], U(0) & = u_0. {aligned}. {equation} Here (A(t))t[0,T](A(t))_{t\in [0,T]} are unbounded operators with domains (D(A(t)))t[0,T](D(A(t)))_{t\in [0,T]} which may be time dependent. We assume that (A(t))t[0,T](A(t))_{t\in [0,T]} satisfies the conditions of Acquistapace and Terreni. The functions FF and BB are nonlinear functions defined on certain interpolation spaces and u0Eu_0\in E is the initial value. WHW_H is a cylindrical Brownian motion on a separable Hilbert space HH. Under Lipschitz and linear growth conditions we show that there exists a unique mild solution of \eqref{eq:SEab}. Under assumptions on the interpolation spaces we extend the factorization method of Da Prato, Kwapie\'n, and Zabczyk, to obtain space-time regularity results for the solution UU of \eqref{eq:SEab}. For Hilbert spaces EE we obtain a maximal regularity result. The results improve several previous results from the literature. The theory is applied to a second order stochastic partial differential equation which has been studied by Sanz-Sol\'e and Vuillermot. This leads to several improvements of their result.Comment: Accepted for publication in Journal of Evolution Equation

    Inertial Mass of a Vortex in Cuprate Superconductors

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    We present here a calculation of the inertial mass of a moving vortex in cuprate superconductors. This is a poorly known basic quantity of obvious interest in vortex dynamics. The motion of a vortex causes a dipolar density distortion and an associated electric field which is screened. The energy cost of the density distortion as well as the related screened electric field contribute to the vortex mass, which is small because of efficient screening. As a preliminary, we present a discussion and calculation of the vortex mass using a microscopically derivable phase-only action functional for the far region which shows that the contribution from the far region is negligible, and that most of it arises from the (small) core region of the vortex. A calculation based on a phenomenological Ginzburg-Landau functional is performed in the core region. Unfortunately such a calculation is unreliable, the reasons for it are discussed. A credible calculation of the vortex mass thus requires a fully microscopic, non-coarse grained theory. This is developed, and results are presented for a s-wave BCS like gap, with parameters appropriate to the cuprates. The mass, about 0.5 mem_e per layer, for magnetic field along the cc axis, arises from deformation of quasiparticle states bound in the core, and screening effects mentioned above. We discuss earlier results, possible extensions to d-wave symmetry, and observability of effects dependent on the inertial mass.Comment: 27 pages, Latex, 3 figures available on request, to appear in Physical Review

    Prime beef cuts : culinary images for thinking 'men'

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    The paper contributes to scholarship theorising the sociality of the brand in terms of subject positions it makes possible through drawing upon the generative context of circulating discourses, in this case of masculinity, cuisine and celebrity. Specifically, it discusses masculinity as a socially constructed gender practice (Bristor and Fischer, 1993), examining materialisations of such practice in the form of visualisations of social relations as resources for 'thinking gender' or 'doing gender'. The transformative potential of the visualisations is illuminated by exploring the narrative content choreographed within a series of photographic images positioning the market appeal of a celebrity chef through the medium of a contemporary lifestyle cookery book. We consider how images of men 'doing masculinity'are not only channelled into reproducing existing gender hierarchy and compulsory heterosexuality in the service of commercial ends, but also into disrupting such enduring stereotyping through subtle reframing. We acknowledge that masculinity is already inscribed within conventionalised representations of culinary culture. In this case we consider how traces of masculinity are exploited and reinscribed through contemporary images that generate resources for rethinking masculine roles and identities, especially when viewed through the lens of stereotypically feminised pursuits such as shopping, food preparation, cooking, and the communal intimacy of food sharing. We identify unsettling tensions within the compositions, arguing that they relate to discursive spaces between the gendered positions written into the images and the popular imagination they feed off. Set against landscapes of culinary culture, we argue that the images invoke a brand of naively roughish "laddishness" or "blokishness", rendering it in domesticated form not only as benign and containable, but fashionable, pliable and, importantly, desirable. We conclude that although the images draw on stereotypical premeditated notions of a feral, boisterous and untamed heterosexual masculinity, they also set in motion gender-blending narratives

    Resistance and Resistance Fluctuations in Random Resistor Networks Under Biased Percolation

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    We consider a two-dimensional random resistor network (RRN) in the presence of two competing biased percolations consisting of the breaking and recovering of elementary resistors. These two processes are driven by the joint effects of an electrical bias and of the heat exchange with a thermal bath. The electrical bias is set up by applying a constant voltage or, alternatively, a constant current. Monte Carlo simulations are performed to analyze the network evolution in the full range of bias values. Depending on the bias strength, electrical failure or steady state are achieved. Here we investigate the steady-state of the RRN focusing on the properties of the non-Ohmic regime. In constant voltage conditions, a scaling relation is found between /0/_0 and V/V0V/V_0, where is the average network resistance, 0_0 the linear regime resistance and V0V_0 the threshold value for the onset of nonlinearity. A similar relation is found in constant current conditions. The relative variance of resistance fluctuations also exhibits a strong nonlinearity whose properties are investigated. The power spectral density of resistance fluctuations presents a Lorentzian spectrum and the amplitude of fluctuations shows a significant non-Gaussian behavior in the pre-breakdown region. These results compare well with electrical breakdown measurements in thin films of composites and of other conducting materials.Comment: 15 figures, 23 page

    Experiments in vortex avalanches

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    Avalanche dynamics is found in many phenomena spanning from earthquakes to the evolution of species. It can be also found in vortex matter when a type II superconductor is externally driven, for example, by increasing the magnetic field. Vortex avalanches associated with thermal instabilities can be an undesirable effect for applications, but "dynamically driven" avalanches emerging from the competition between intervortex interactions and quenched disorder constitute an interesting scenario to test theoretical ideas related with non-equilibrium dynamics. However, differently from the equilibrium phases of vortex matter in type II superconductors, the study of the corresponding dynamical phases - in which avalanches can play a role - is still in its infancy. In this paper we critically review relevant experiments performed in the last decade or so, emphasizing the ability of different experimental techniques to establish the nature and statistical properties of the observed avalanche behavior.Comment: To be published in Reviews of Modern Physics April 2004. 17 page

    Hsp90 governs dispersion and drug resistance of fungal biofilms

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    Fungal biofilms are a major cause of human mortality and are recalcitrant to most treatments due to intrinsic drug resistance. These complex communities of multiple cell types form on indwelling medical devices and their eradication often requires surgical removal of infected devices. Here we implicate the molecular chaperone Hsp90 as a key regulator of biofilm dispersion and drug resistance. We previously established that in the leading human fungal pathogen, Candida albicans, Hsp90 enables the emergence and maintenance of drug resistance in planktonic conditions by stabilizing the protein phosphatase calcineurin and MAPK Mkc1. Hsp90 also regulates temperature-dependent C. albicans morphogenesis through repression of cAMP-PKA signalling. Here we demonstrate that genetic depletion of Hsp90 reduced C. albicans biofilm growth and maturation in vitro and impaired dispersal of biofilm cells. Further, compromising Hsp90 function in vitro abrogated resistance of C. albicans biofilms to the most widely deployed class of antifungal drugs, the azoles. Depletion of Hsp90 led to reduction of calcineurin and Mkc1 in planktonic but not biofilm conditions, suggesting that Hsp90 regulates drug resistance through different mechanisms in these distinct cellular states. Reduction of Hsp90 levels led to a marked decrease in matrix glucan levels, providing a compelling mechanism through which Hsp90 might regulate biofilm azole resistance. Impairment of Hsp90 function genetically or pharmacologically transformed fluconazole from ineffectual to highly effective in eradicating biofilms in a rat venous catheter infection model. Finally, inhibition of Hsp90 reduced resistance of biofilms of the most lethal mould, Aspergillus fumigatus, to the newest class of antifungals to reach the clinic, the echinocandins. Thus, we establish a novel mechanism regulating biofilm drug resistance and dispersion and that targeting Hsp90 provides a much-needed strategy for improving clinical outcome in the treatment of biofilm infections

    Atomic structures of TDP-43 LCD segments and insights into reversible or pathogenic aggregation.

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    The normally soluble TAR DNA-binding protein 43 (TDP-43) is found aggregated both in reversible stress granules and in irreversible pathogenic amyloid. In TDP-43, the low-complexity domain (LCD) is believed to be involved in both types of aggregation. To uncover the structural origins of these two modes of β-sheet-rich aggregation, we have determined ten structures of segments of the LCD of human TDP-43. Six of these segments form steric zippers characteristic of the spines of pathogenic amyloid fibrils; four others form LARKS, the labile amyloid-like interactions characteristic of protein hydrogels and proteins found in membraneless organelles, including stress granules. Supporting a hypothetical pathway from reversible to irreversible amyloid aggregation, we found that familial ALS variants of TDP-43 convert LARKS to irreversible aggregates. Our structures suggest how TDP-43 adopts both reversible and irreversible β-sheet aggregates and the role of mutation in the possible transition of reversible to irreversible pathogenic aggregation
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