Supersymmetric near-horizon geometry and Einstein-Cartan-Weyl spaces

We show that the horizon geometry for supersymmetric black hole solutions of minimal five-dimensional gauged supergravity is that of a particular Einstein-Cartan-Weyl (ECW) structure in three dimensions, involving the trace and traceless part of both torsion and nonmetricity, and obeying some precise constraints. In the limit of zero cosmological constant, the set of nonlinear partial differential equations characterizing this ECW structure reduces correctly to that of a hyper-CR Einstein-Weyl structure in the Gauduchon gauge, which was shown by Dunajski, Gutowski and Sabra to be the horizon geometry in the ungauged BPS case.Comment: 15 page

Schr\"odinger connection with selfdual nonmetricity vector in 2+1 dimensions

We present a three-dimensional metric affine theory of gravity whose field equations lead to a connection introduced by Schr\"odinger many decades ago. Although involving nonmetricity, the Schr\"odinger connection preserves the length of vectors under parallel transport, and appears thus to be more physical than the one proposed by Weyl. By considering solutions with constant scalar curvature, we obtain a self-duality relation for the nonmetricity vector which implies a Proca equation that may also be interpreted in terms of inhomogeneous Maxwell equations emerging from affine geometry.Comment: 5 page

On SIR-type epidemiological models and population heterogeneity effects

In this paper we elaborate on homogeneous and heterogeneous SIR-type epidemiological models. We find an unexpected correspondence between the epidemic trajectory of a transmissible disease in a homogeneous SIR-type model and radial null geodesics in the Schwarzschild spacetime. We also discuss modeling of population heterogeneity effects by considering both a one- and two-parameter gamma-distributed function for the initial susceptibility distribution, and deriving the associated herd immunity threshold. We furthermore describe how mitigation measures can be taken into account by model fitting.Comment: 16 pages, 6 figure

Rotating black holes with Nil or SL(2, R\,\mathbb{R}) horizons

We construct rotating black holes in $N=2$, $D=5$ minimal and matter-coupled gauged supergravity, with horizons that are homogeneous but not isotropic. Such spaces belong to the eight Thurston model geometries, out of which we consider the cases Nil and SL$(2,\mathbb{R})$. In the former, we use the recipe of arXiv:hep-th/0304064 to directly rederive the solution that was obtained by Gutowski and Reall in arXiv:hep-th/0401042 as a scaling limit from a spherical black hole. With the same techniques, the first example of a black hole with SL$(2,\mathbb{R})$ horizon is constructed, which is rotating and one quarter BPS. The physical properties of this solution are discussed, and it is shown that in the near-horizon limit it boils down to the geometry of arXiv:hep-th/0401042, with a supersymmetry enhancement to one half. Dimensional reduction to $D=4$ gives a new solution with hyperbolic horizon to the t$^3$ model that carries both electric and magnetic charges. Moreover, we show how to get a nonextremal rotating Nil black hole by applying a certain scaling limit to Kerr-AdS$_5$ with two equal rotation parameters, which consists in zooming onto the north pole of the S$^2$ over which the S$^3$ is fibered, while boosting the horizon velocity effectively to the speed of light.Comment: 24 page

Intentions and barriers to help-seeking in adolescents and young adults differing in depression severity: cross-sectional results from a school-based mental health project.

BACKGROUND Mental health problems, such as depression, have a high prevalence in young people. However, the majority of youths suffering from depression do not seek professional help. This study aimed to compare help-seeking behavior, intentions and perceived barriers between youthswith different levels of depressive symptoms. METHODS This cross-sectional study is part of a large-scale, multi-center project. Participants were n = 9509 youths who were recruited in German schools and completed a baseline screening questionnaire. Based on their depressive symptoms, youths were allocated to the following three subgroups: (a) without depressive symptoms, (b) with subclinical symptoms, (c) with clinical symptoms (measured by PHQ-A). Quantitative analyses compared previous help-seeking behavior, help-seeking intentions and perceived barriers (Barriers questionnaire) between these subgroups. An additional exploratory qualitative content analysis examined text answers on other perceived barriers to help-seeking. RESULTS Participants were mostly female (n = 5575, 58.6%) and 12 to 24 years old (M = 15.09, SD 2.37). Participants with different levels of depressive symptoms differed significantly in help-seeking behavior, intentions and perceived barriers. Specifically, participants with clinical depressive symptoms reported more previous help-seeking, but lower intentions to seek help compared to participants without symptoms (all p < 0.05). Participants with subclinical depressive symptoms reported a similar frequency of previous help-seeking, but higher intentions to seek help compared to participants without symptoms (all p < 0.05). Perception of barriers was different across subgroups: participants with clinical and subclinical depressive symptoms perceived the majority of barriers such as stigma, difficulties in accessibility, and family-related barriers as more relevant than participants without depressive symptoms. Across all subgroups, participants frequently mentioned intrapersonal reasons, a high need for autonomy, and a lack of mental health literacy as barriers to help-seeking. CONCLUSIONS Youths with higher levels of depressive symptoms are more reluctant to seek professional help and perceive higher barriers. This underlines the need for effective and low-threshold interventions to tackle barriers, increase help-seeking, and lower depressive symptoms in adolescents and young adults differing in depression severity. TRIAL REGISTRATION DRKS00014685

Impaired working speed and executive functions as frontal lobe dysfunctions in young first-degree relatives of schizophrenic patients

The aim of the investigation was to detect neuropsychological markers, such as sustained and selective attention and executive functions, which contribute to the vulnerability to schizophrenia especially in young persons. Performance was assessed in 32 siblings and children of schizophrenic patients and 32 matched controls using Wisconsin Card Sorting Test, Colour-Word-Interference-Test, Trail Making Test, and d2-Concentration-Test. The first-degree relatives showed certain impairments on all four tests, in particular, slower times on all time-limited tests. These results suggest the need for more time when completing neuropsychological tasks involving selected and focused attention, as well as cognitive flexibility, as a possible indicator of genetic vulnerability to schizophrenia