Weak lensing detection of intra-cluster filaments with ground based data

According to the current standard model of Cosmology, matter in the Universe arranges itself along a network of filamentary structure. These filaments connect the main nodes of this so-called 'Cosmic Web', which are clusters of galaxies. Although its large-scale distribution is clearly characterized by numerical simulations, constraining the dark matter content of the cosmic web in reality turns out to be difficult. The natural method of choice is gravitational lensing. However, the direct detection and mapping of the elusive filament signal is challenging and in this work we present two methods,specifically tailored to achieve this task. A linear matched filter aims at the detection of the smooth mass component of filaments and is optimized to perform a shear decomposition that follows the anisotropic component of the lensing signal. Filaments clearly inherit this property due to their morphology. At the same time, the contamination arising from the central massive cluster is controlled in a natural way. The filament 1 {\sigma} detection is of about {\kappa} ~ 0.01-0.005 according to the filter's template width and length, enabling the detection of structures out of reach with other approaches. The second, complementary method seeks to detect the clumpy component of filaments. The detection is determined by the number density of sub-clump identifications in an area enclosing the potential filament, as it was found within the observed field with the filter approach. We test both methods against Mock observations based on realistic N-Body simulations of filamentary structure and prove the feasibility of detecting filaments with ground-based data.Comment: 9 pages, 7 figures. Submitted to A&A. Comments very welcom

Improving education outcomes: in colleges, universities, and beyond

While most of the attention of the public, the policymakers, and this conference is on improving our K -12 education system, our higher education also needs attention. Higher education is undergoing dramatic changes that have to be considered in conjunction with the demands on and the changes in the K -12 system. Similarly, there are common needs of the two systems, and lessons from higher education should be considered in any K -12 reform proposal.Education

Research note: an analytical perspective on market decisions and asymmetric cost behavior

Asymmetric cost behavior has attracted the interest of many (empirical) researchers in the last years. Prior research determines several sources of this behavior such as resource adjustment costs, uncertainties and related beliefs, agency problems, and fixed costs. Empirical studies measure firms’ cost behavior using total firm costs and sales. In imperfect markets, firms react to changing market conditions by adapting output prices and quantities so that both total firm costs and sales are affected. However, changing output prices only directly affects sales and not costs. Based on an economic model, we identify market decisions (output quantity and pricing decisions) as an additional source of measured asymmetric cost behavior

Bilder als historische Quellen: Eine Interpretation der Moskauer Bilderchronik "Licevoj Letopisnij Svod" (16. Jahrhundert)

1. Bild und Geschichte – grundsätzliche Überlegungen 2. Geschichtsbild und Ikonographie 3. Bildwirkung und politisches Handeln 4. Bibliographi

Non-uptake of HIV testing in children at risk in two urban and rural settings in Zambia: a mixed-methods study

This article investigates reasons why children who were considered at risk of HIV were not taken for HIV testing by their caregivers. Qualitative and quantitative data collected in Zambia from 2010-11 revealed that twelve percent of caregivers who stated that they had been suspecting an HIV infection in a child in their custody had not had the child tested. Fears of negative reactions from the family were the most often stated reason for not testing a child. Experience of pre-existing conflicts between the couple or within the family (aOR 1.35, 95% CI 1.00-1.82) and observed stigmatisation of seropositive children in one's own neighbourhood (aOR 1.69, 95% CI1.20-2.39) showed significant associations for not testing a child perceived at risk of HIV. Although services for HIV testing and treatment of children have been made available through national policies and programmes, some women and children were denied access leading to delayed diagnosis and treatment-not on the side of the health system, but on the household level. Social norms, such as assigning the male household head the power to decide over the use of healthcare services by his wife and children, jeopardize women's bargaining power to claim their rights to healthcare, especially in a conflict-affected relationship. Social norms and customary and statutory regulations that disadvantage women and their children must be addressed at every level-including the community and household-in order to effectively decrease barriers to HIV related care

Semileptonic decays of baryons in a relativistic quark model

We calculate semileptonic decays of light and heavy baryons in a relativistically covariant constituent quark model. The model is based on the Bethe-Salpeter-equation in instantaneous approximation. It generates satisfactory mass spectra for mesons and baryons up to the highest observable energies. Without introducing additional free parameters we compute on this basis helicity amplitudes of electronic and muonic semileptonic decays of baryons. We thus obtain form factor ratios and decay rates in good agreement with experiment.Comment: 8 pages, 10 figures, 2 tables, typos remove

A Relativistic Quark Model for Mesons with an Instanton-Induced Interaction

We present new results of a relativistic quark model based on the Bethe-Salpeter equation in its instantaneous approximation. Assuming a linearly rising confinement potential with an appropriate spinorial structure in Dirac space and adopting a residual interaction based on instanton effects, we can compute masses of the light mesons up to highest observed angular momenta with a natural solution of the $U_A(1)$ problem. The calculated ground states masses and the radial excitations describe the experimental results well. In this paper, we will also discuss our results concerning numerous meson decay properties. For processes like $\pi^+/K^+\to e^+\nu_e\gamma$ and $0^-\to\gamma\gamma$ at various photon virtualities, we find a good agreement with experimental data. We will also comment on the form factors of the $K_{\ell 3}$ decay and on the decay constants of the $\pi$, $K$ and $\eta$ mesons. For the sake of completeness, we will furthermore present the electromagnetic form factors of the charged $\pi$ and $K$ mesons as well as a comparison of the radiative meson decay widths with the most recent experimental data.Comment: 30 pages including 10 tables and 16 figures; submitted to Eur. Phys. J. A; misprints correcte

Electromagnetic form factors of hyperons in a relativistic quark model

The relativistically covariant constituent quark model developed by the Bonn group is used to compute the EM form factors of strange baryons. We present form-factor results for the ground-state and some excited hyperons. The computed magnetic moments agree well with the experimental values and the magnetic form factors follow a dipole $Q^2$ dependence.Comment: 4 pages, 1 figure, Proceedings for NSTAR '04 conference in Grenoble, France, March 24-27, 2004 (World Scientific