Bosonic and fermionic Weinberg-Joos (j,0)+ (0,j) states of arbitrary spins as Lorentz-tensors or tensor-spinors and second order theory

We propose a general method for the description of arbitrary single spin-j states transforming according to (j,0)+(0,j) carrier spaces of the Lorentz algebra in terms of Lorentz-tensors for bosons, and tensor-spinors for fermions, and by means of second order Lagrangians. The method allows to avoid the cumbersome matrix calculus and higher \partial^{2j} order wave equations inherent to the Weinberg-Joos approach. We start with reducible Lorentz-tensor (tensor-spinor) representation spaces hosting one sole (j,0)+(0,j) irreducible sector and design there a representation reduction algorithm based on one of the Casimir invariants of the Lorentz algebra. This algorithm allows us to separate neatly the pure spin-j sector of interest from the rest, while preserving the separate Lorentz- and Dirac indexes. However, the Lorentz invariants are momentum independent and do not provide wave equations. Genuine wave equations are obtained by conditioning the Lorentz-tensors under consideration to satisfy the Klein-Gordon equation. In so doing, one always ends up with wave equations and associated Lagrangians that are second order in the momenta. Specifically, a spin-3/2 particle transforming as (3/2,0)+ (0,3/2) is comfortably described by a second order Lagrangian in the basis of the totally antisymmetric Lorentz tensor-spinor of second rank, \Psi_[ \mu\nu]. Moreover, the particle is shown to propagate causally within an electromagnetic background. In our study of (3/2,0)+(0,3/2) as part of \Psi_[\mu\nu] we reproduce the electromagnetic multipole moments known from the Weinberg-Joos theory. We also find a Compton differential cross section that satisfies unitarity in forward direction. The suggested tensor calculus presents itself very computer friendly with respect to the symbolic software FeynCalc.Comment: LaTex 34 pages, 1 table, 8 figures. arXiv admin note: text overlap with arXiv:1312.581

The bias-extension test for the analysis of in-plane shear properties of textile composite reinforcements and prepregs: a review

The bias-extension test is a rather simple experiment aiming to determine in-plane shear properties of textile composite reinforcements. However the mechanics during the test involves fibrous material at large shear strains and large rotations of the fibres. Several aspects are still being studied and are not yet modeled in a consensual manner. The standard analysis of the test is based on two assumptions: inextensibility of the fibers and rotations at the yarn crossovers without slippage. They lead to the development of zones with constant fibre orientations proper to the bias-extension test. Beyond the analysis of the test within these basic assumptions, the paper presents studies that have been carried out on the lack of verification of these hypothesis (slippage, tension in the yarns, effects of fibre bending). The effects of temperature, mesoscopic modeling and tension locking are also considered in the case of the bias-extension test

Globular clusters and dwarf galaxies in Fornax - I. Kinematics in the cluster core from multi-object spectroscopy

We acquired radial velocities of a significant number of globular clusters (GCs) on wide fields between galaxies in the nearby Fornax cluster of galaxies, in order to derive their velocity dispersion radial profile and to probe the dynamics of the cluster. We used FLAMES on the VLT to obtain accurate velocities for 149 GCs, within a ~500x150 kpc strip centered on NGC 1399, the Fornax central galaxy. These objects are at the very bright tail (M_V < -9.5) of the GC luminosity function, overlapping the so-called ``ultra-compact dwarfs'' magnitude range. Eight of the brightest FLAMES-confirmed members indeed show hints of resolution in the subarcsecond pre-imaging data we used for selecting the ~500 targets for FLAMES spectroscopy. Ignoring the GCs around galaxies by applying 3d_25 diameter masks, we find 61 GCs of 20.0 < V < 22.2 lying in the intra-cluster (IC) medium. The velocity dispersion of the population of ICGCs is 200 km/s at ~150 kpc from the central NGC 1399 and rises to nearly 400 km/s at 200 kpc, a value which compares with the velocity dispersion of the population of dwarf galaxies, thought to be infalling from the surroundings of the cluster.Comment: To be published in A&A Letters. 4 pages, 3 figures, 3 table

Molecular Requirements for Ethanol Differential Allosteric Modulation of Ligand-Gated Ion Channels Based on Selective G Beta Gamma Modulation

It is now believed that the allosteric modulation produced by ethanol in glycine receptors (GlyRs) depends on alcohol binding to discrete sites within the protein structure. Thus, the differential ethanol sensitivity of diverse GlyR isoforms and mutants was explained by the presence of specific residues in putative alcohol pockets. Here, we demonstrate that ethanol sensitivity in two LGIC members, the GlyR adult alpha1 and embryonic alpha2 subunits, can be modified through selective mutations that rescued or impaired Gbetagamma modulation. Even though that both isoforms were able to physically interact with Gbetagamma, only the alpha1 GlyR was functionally modulated by Gbetagamma and pharmacological ethanol concentrations. Remarkably, the simultaneous switching of two transmembrane and a single extracellular residue in alpha2 GlyRs was enough to generate GlyRs modulated by Gbetagamma and low ethanol concentrations. Interestingly, while we found that these TM residues were different to those in the alcohol binding site, the extracellular residue was recently implicated in conformational changes important to generate a pre-open activated state that precedes ion channel gating. Thus, these results support the idea that the differential ethanol sensitivity of these two GlyR isoforms rests on conformational changes in transmembrane and extracellular residues within the ion channel structure rather than in differences in alcohol binding pockets. Our results describe the molecular basis for the differential ethanol sensitivity of two LGIC members based on selective Gbetagamma modulation and provide a new mechanistic framework for allosteric modulations of abuse drugs

Probing the Super Star Cluster Environment of NGC 1569 Using FISICA

We present near-IR JH spectra of the central regions of the dwarf starburst galaxy NGC 1569 using the Florida Image Slicer for Infrared Cosmology and Astrophysics (FISICA). The dust-penetrating properties and available spectral features of the near-IR, combined with the integral field unit (IFU) capability to take spectra of a field, make FISICA an ideal tool for this work. We use the prominent [He I] (1.083\mu m) and Pa\beta (1.282 \mu m) lines to probe the dense star forming regions as well as characterize the general star forming environment around the super star clusters (SSCs) in NGC 1569. We find [He I] coincident with CO clouds to the north and west of the SSCs, which provides the first, conclusive evidence for embedded star clusters here.Comment: 6 pages, 3 figures, accepted for publication in the MNRA

Galaxy Halo Masses from Galaxy-Galaxy Lensing

We present measurements of the extended dark halo profiles of bright early type galaxies at redshifts 0.1 to 0.9 obtained via galaxy-galaxy lensing analysis of images taken at the CFHT using the UH8K CCD mosaic camera. Six half degree fields were observed for a total of 2 hours each in I and V, resulting in catalogs containing ~20 000 galaxies per field. We used V-I color and I magnitude to select bright early type galaxies as the lens galaxies, yielding a sample of massive lenses with fairly well determined redshifts and absolute magnitudes M ~ M_* \pm 1. We paired these with faint galaxies lying at angular distances 20" to 60", corresponding to physical radii of 26 to 77 kpc (z = 0.1) and 105 to 315 kpc (z = 0.9), and computed the mean tangential shear of the faint galaxies. The shear falls off with radius roughly as expected for flat rotation curve halos. The shear values were weighted in proportion to the square root of the luminosity of the lens galaxy. Our results give a value for the average mean rotation velocity of an L_* galaxy halo at r~50-200 kpc of v_* = 238^{+27}_{-30} km per sec for a flat lambda (Omega_m0 = 0.3, Omega_l0 = 0.7) cosmology (v_* = 269^{+34}_{-39} km per sec for Einstein-de Sitter), and with little evidence for evolution with redshift. We compare to halo masses measured by other groups/techniques. We find a mass-to-light ratio of ~121\pm28h(r/100 kpc) and these halos constitute Omega ~0.04 \pm 0.01(r/100 kpc) of closure density. (abridged)Comment: Accepted for publication in ApJ (minor modifications) - 32 pages, 11 figs, 5 table

The contribution of ultracompact dark matter minihalos to the isotropic radio background

The ultracompact minihalos could be formed during the earlier epoch of the universe. The dark matter annihilation within them is very strong due to the steep density profile, $\rho \sim r^{-2.25}$. The high energy electrons and positrons from the dark matter annihilation can inverse Compton scatter (ICS) with the background photons, such as CMB photons, to acquire higher energy. On the other hand, the synchrotron radiation can also be produced when they meet the magnetic field. In this paper, we study the signals from the UCMHs due to the dark matter annihilation for the radio, X-ray and $\gamma$-ray band. We found that for the radio emission the UCMHs can provide one kind of source for the radio excess observed by ARCADE 2. But the X-ray signals due to the ICS effect or the $\gamma$-ray signals mainly due to the prompt emission from dark matter would exceed the present observations, such as Fermi, COMPTEL and CHANDRA. We found that the strongest limits on the fraction of UCMHs come from the X-ray observations and the constraints from the radio data are the weakest.Comment: 6 pages, 8 figures, Comments Welcome! Some Refs. are added, some presentation have been corrected. The conclusions remain unchanged. One important reference has been corrected. Some presentations are changed and added according to the referee's comments. Accepted for publication in PR

Construction and testing of the optical bench for LISA pathfinder

eLISA is a space mission designed to measure gravitational radiation over a frequency range of 0.1–100 mHz (European Space Agency LISA Assessment Study Report 2011). It uses laser interferometry to measure changes of order $10\,{\rm pm /\sqrt{Hz}}$ in the separation of inertial test masses housed in spacecraft separated by 1 million km. LISA Pathfinder (LPF) is a technology demonstrator mission that will test the key eLISA technologies of inertial test masses monitored by laser interferometry in a drag-free spacecraft. The optical bench that provides the interferometry for LPF must meet a number of stringent requirements: the optical path must be stable at the few ${\rm pm /\sqrt{Hz}}$ level; it must direct the optical beams onto the inertial masses with an accuracy of better than ±25 μm, and it must be robust enough not only to survive launch vibrations but to achieve full performance after launch. In this paper we describe the construction and testing of the flight optical bench for LISA Pathfinder that meets all the design requirements

Development of a Soil Carbon Index for Iowa Mineral Soils

A carbon index (Cl) is one of many soil quality indicators that depends on organic carbon concentration. One of the values of a soil carbon index is in determining the impact of agriculture practices (i.e., tillage, crop rotation, N management, etc.) on soil organic matter status of mineral soils. Interactions of climate, parent material, topography, time, and organisms including human activities influence soil organic carbon (SOC). This study developed a soil carbon index for mineral soil map units in Iowa using data collected by the Iowa Cooperative Soil Survey Laboratory and the USDA Soil Survey Laboratory for over 2,300 soil map units across the state in the past 20-30 years. The results show that the soil CI is highly influenced by soil forming factors. The highest soil carbon index was associated with soil map units of soils that are poorly drained, have moderately fine textures, and are on relatively flat topography as in the Clarion-Nicollet-Webster soils association area in north-central Iowa. Additionally, there was a negative correlation between the number of hectares of soils formed under deciduous forest vegetation and CI values within a county. The CI is also related to soil productivity in the state. Fifty five percent of the variability of the corn suitability ratings was explained by the CI. The CI is a valuable tool in evaluating soil organic matter status, productivity of Iowa soils, and land valu

Differential Disease Susceptibilities in Experimentally Reptarenavirus-Infected Boa Constrictors and Ball Pythons.

Inclusion body disease (IBD) is an infectious disease originally described in captive snakes. It has traditionally been diagnosed by the presence of large eosinophilic cytoplasmic inclusions and is associated with neurological, gastrointestinal, and lymphoproliferative disorders. Previously, we identified and established a culture system for a novel lineage of arenaviruses isolated from boa constrictors diagnosed with IBD. Although ample circumstantial evidence suggested that these viruses, now known as reptarenaviruses, cause IBD, there has been no formal demonstration of disease causality since their discovery. We therefore conducted a long-term challenge experiment to test the hypothesis that reptarenaviruses cause IBD. We infected boa constrictors and ball pythons by cardiac injection of purified virus. We monitored the progression of viral growth in tissues, blood, and environmental samples. Infection produced dramatically different disease outcomes in snakes of the two species. Ball pythons infected with Golden Gate virus (GoGV) and with another reptarenavirus displayed severe neurological signs within 2 months, and viral replication was detected only in central nervous system tissues. In contrast, GoGV-infected boa constrictors remained free of clinical signs for 2 years, despite high viral loads and the accumulation of large intracellular inclusions in multiple tissues, including the brain. Inflammation was associated with infection in ball pythons but not in boa constrictors. Thus, reptarenavirus infection produces inclusions and inclusion body disease, although inclusions per se are neither necessarily associated with nor required for disease. Although the natural distribution of reptarenaviruses has yet to be described, the different outcomes of infection may reflect differences in geographical origin.IMPORTANCE New DNA sequencing technologies have made it easier than ever to identify the sequences of microorganisms in diseased tissues, i.e., to identify organisms that appear to cause disease, but to be certain that a candidate pathogen actually causes disease, it is necessary to provide additional evidence of causality. We have done this to demonstrate that reptarenaviruses cause inclusion body disease (IBD), a serious transmissible disease of snakes. We infected boa constrictors and ball pythons with purified reptarenavirus. Ball pythons fell ill within 2 months of infection and displayed signs of neurological disease typical of IBD. In contrast, boa constrictors remained healthy over 2 years, despite high levels of virus throughout their bodies. This difference matches previous reports that pythons are more susceptible to IBD than boas and could reflect the possibility that boas are natural hosts of these viruses in the wild