Cosmological constraints from COMBO-17 using 3D weak lensing

We present the first application of the 3D cosmic shear method developed in Heavens et al. (2006) and the geometric shear-ratio analysis developed in Taylor et al. (2006), to the COMBO-17 data set. 3D cosmic shear has been used to analyse galaxies with redshift estimates from two random COMBO-17 fields covering 0.52 square degrees in total, providing a conditional constraint in the (sigma_8, Omega_m) plane as well as a conditional constraint on the equation of state of dark energy, parameterised by a constant w= p/rho c^2. The (sigma_8, Omega_m) plane analysis constrained the relation between sigma_8 and Omega_m to be sigma_8(Omega_m/0.3)^{0.57 +- 0.19}=1.06 +0.17 -0.16, in agreement with a 2D cosmic shear analysis of COMBO-17. The 3D cosmic shear conditional constraint on w using the two random fields is w=-1.27 +0.64 -0.70. The geometric shear-ratio analysis has been applied to the A901/2 field, which contains three small galaxy clusters. Combining the analysis from the A901/2 field, using the geometric shear-ratio analysis, and the two random fields, using 3D cosmic shear, w is conditionally constrained to w=-1.08 +0.63 -0.58. The errors presented in this paper are shown to agree with Fisher matrix predictions made in Heavens et al. (2006) and Taylor et al. (2006). When these methods are applied to large datasets, as expected soon from surveys such as Pan-STARRS and VST-KIDS, the dark energy equation of state could be constrained to an unprecedented degree of accuracy.Comment: 10 pages, 4 figures. Accepted to MNRA

A Note on Transfinite M Theory and the Fine Structure Constant

In this short note, using notions from $p$-Adic QFT and $p$-branes, we derive the transfinite M $theoretical$ corrections $(\alpha_M)^{-1} = 100 + 61 \phi$ to El Naschie's inverse fine structure constant value $(\alpha_{HS})^{-1}= 100 + 60\phi$ which was based on a transfinite Heterotic string theory ormalism . $\phi$ is the Golden Mean $0.6180339...$. Our results are consistent with recent Astrophysical observations of he Boomerang and Maxima experiments, with previous results based on the four dimensional gravitational conformal anomaly calculations and with an enhanced hierarchy of the number of lines on Del Pezzo surfaces.Comment: 11 pages,LaTe

Abnormal connectional fingerprint in schizophrenia: a novel network analysis of diffusion tensor imaging data

The graph theoretical analysis of structural magnetic resonance imaging (MRI) data has received a great deal of interest in recent years to characterize the organizational principles of brain networks and their alterations in psychiatric disorders, such as schizophrenia. However, the characterization of networks in clinical populations can be challenging, since the comparison of connectivity between groups is influenced by several factors, such as the overall number of connections and the structural abnormalities of the seed regions. To overcome these limitations, the current study employed the whole-brain analysis of connectional fingerprints in diffusion tensor imaging data obtained at 3 T of chronic schizophrenia patients (n = 16) and healthy, age-matched control participants (n = 17). Probabilistic tractography was performed to quantify the connectivity of 110 brain areas. The connectional fingerprint of a brain area represents the set of relative connection probabilities to all its target areas and is, hence, less affected by overall white and gray matter changes than absolute connectivity measures. After detecting brain regions with abnormal connectional fingerprints through similarity measures, we tested each of its relative connection probability between groups. We found altered connectional fingerprints in schizophrenia patients consistent with a dysconnectivity syndrome. While the medial frontal gyrus showed only reduced connectivity, the connectional fingerprints of the inferior frontal gyrus and the putamen mainly contained relatively increased connection probabilities to areas in the frontal, limbic, and subcortical areas. These findings are in line with previous studies that reported abnormalities in striatal–frontal circuits in the pathophysiology of schizophrenia, highlighting the potential utility of connectional fingerprints for the analysis of anatomical networks in the disorder

Electromagnetic inertia, reactive energy, and energy flow velocity

In a recent paper titled "Coherent electromagnetic wavelets and their twisting null congruences," I defined the local inertia density (I), reactive energy density (R), and energy flow velocity (v) of an electromagnetic field. These are the field equivalents of the mass, rest energy, and velocity of a relativistic particle. Thus R and I are Lorentz-invariant and |v|<=c, with equality if and only if R=0. The exceptional fields with |v|=c were called "coherent" because their energy moves in complete harmony with the field, leaving no inertia or reactive energy behind. Generic electromagnetic fields become coherent only in the far zone. Elsewhere, their energy flows at speeds |v|<c. The purpose of this paper is to confirm and clarify this statement by studying the local energy flow in several common systems: a time-harmonic electric dipole field, a time-dependent electric dipole field, and a standing plane wave. For these fields, the energy current (Poynting vector) is too weak to carry away all of the energy, thus leaving reactive energy in its wake. For the time-dependent dipole field, we find that the energy can flow both transversally and inwards, back to the source. Neither of these phenomena show up in the usual computation of the energy transport velocity which considers only averages over one period in the time-harmonic case.Comment: 20 pages, 7 figure

Steigerung des Nachhaltigkeitsbewusstseins von Konsument/innen

Konsument/innen lassen sich nicht gleichermaßen für nachhaltiges Handeln begeistern. Ist es Unternehmen daher möglich, auf das Nachhaltigkeitsbewusstsein von Konsumierenden positiven Einfluss zu nehmen? Das Konzept zeigt auf, welche Maßnahmen aus Unternehmenssicht bezüglich der Steigerung des Nachhaltigkeitsbewusstseins getroffen werden können und wie sich diese umsetzen lassen

Flexibilisierung von Arbeitszeiten und Arbeitsformen in Bibliotheken

Die vorliegende, von Studierenden der Fachhochschule für Bibliothekswesen in Frankfurt am Main erstellte Projektarbeit befaßt sich mit Fragen, Aspekten und Möglichkeiten der Flexibilisierung von Arbeitszeiten und Arbeitsformen in Bibliotheken. Im ersten Teil der Arbeit werden die wichtigsten Arbeitsteilzeitmodelle vorgestellt und deren Vorteile für Arbeitgeber und nehmer herausgearbeitet. Anschließend erfolgt eine durch Graphiken und Tabellen veranschaulichte Untersuchung von drei ausgewählte Universitätsbibliotheken (Gießen, Marburg, Mainz) in bezug auf bereits existierende Arbeitszeitflexibilisierung. Ein Ausblick geht der Frage nach, ob die dargestellten Teilzeitmodelle für Bibliotheken notwendig und ausreichend sind. Der zweite Themenkomplex befaßt sich mit der Telearbeit als einer innovativen Arbeitsform in Bibliotheken. Ausgehend von einer Begriffsbestimung werden verschiedene Formen der Telearbeit sowie deren Vor und Nachteile geschildert. Es wird erläutert, welche Bedingungen an den Telearbeiter und seinen Arbeitsplatz geknüpft sind, welche rechtlichen Voraussetzungen erfüllt werden müssen, welche finanziellen Aspekte eine Rolle spielen und welche Anwendungsmöglichkeiten für Telearbeit in Bibliotheken bestehen. An drei konkreten Beispielen wird dann geschildert, wie Telearbeit in Bibliotheken bereits verwirklicht wurde. Abschließend wird der Frage nachgegangen, welche Perspektiven der Einsatz von Telearbeit in Bibliotheken hat. Der dritte Abschnitt der Ausarbeitung stellt das bibliothekarische Call Center als neue Form einer benutzerorientierten Einrichtung vor. Zielsetzungen und Dienstleistungsformen des Call Centers werden ebenso abgehandelt wie Aspekte der Planung, Einrichtung und Arbeitsplatzergonomie sowie des Einsatzes von Telearbeit. Anhand des Beispiels der Zentral und Landesbibliothek Berlin wird schließlich dokumentiert, wie sich ein bibliothekarisches Call Center in der Praxis bereits bewährt hat

Mapping the 3-D dark matter with weak lensing in COMBO-17

We present a 3-dimensional lensing analysis of the z=0.16 supercluster A901/2, resulting in a 3-D map of the dark matter distribution within a 3 X 10^{5} [Mpc]^3 volume from the COMBO-17 survey. We perform a chi^2-fit of isothermal spheres to the tangential shear pattern around each cluster as a function of redshift to estimate the 3-D positions and masses of the main clusters in the supercluster from lensing alone. We then present the first 3-D map of the dark matter gravitational potential field, Phi, using the Kaiser-Squires (1993) and Taylor (2001) inversion methods. These maps clearly show the potential wells of the main supercluster components, including a new cluster behind A902, and demonstrates the applicability of 3-D dark matter mapping and projection free-mass-selected cluster finding to current data. Finally, we develop the halo model of dark matter and galaxy clustering and compare this with the auto-and cross-correlation functions of the 3-D gravitational potential, galaxy number densities and galaxy luminosity densities measured in the A901/2 field. We find significant anti-correlations between the gravitational potential field and the galaxy number density and luminosities, as expected due to baryonic infall into dark matter concentrations. We find good agreement with the halo model for the number densities and luminosity correlation functions.Comment: Submitted to MNRAS; 21 pages, 18 figure