Lee Shapiro to James Meredith (2 October 1962)

https://egrove.olemiss.edu/mercorr_pro/1550/thumbnail.jp

The relationship between job characteristics, decent work, and well-being in South Africa's private security sector

South Africa's private security sector has become amongst the largest in the world. Research has shown that for the largest category of private security employees - security guards – employment tends to be insecure, wages low, working hours long and few have access to social benefits, such as pay for sick leave, unemployment, retirement, housing, education or family circumstances. This study aimed to investigate if job characteristics should be considered as an aspect relevant for creating decent work for security guards, thus allowing security guards to have a considerable degree of well-being through their work. Specifically, this study asked: Does adding meaningfulness created through a job's content as an indicator of decent work strengthen the relationship among decent work and well-being compared to current decent work indicators? Security guards around South Africa were asked to respond to a questionnaire which assessed job characteristics, decent work, and well-being levels. Analysis of the 98 response sets demonstrated that the job characteristics of security guards appear to have no influence on their perception of decent work nor their well-being, except for task identity which predicted well-being. Managers of private security companies may increase task identity by involving security guards in more aspects of work by enabling them take part in the planning, reporting, and evaluation of projects. This could be including the security guards in meetings with community forums so that they understand crime trends. Future research in the private security sector in South Africa is needed to create awareness of the unfavourable working conditions that many low-level security guards experience and how these can be ameliorated. This would allow private security companies to incorporate socially responsible practices regarding their employees' working conditions which are likely to increase security guards' job productivity at the same time

Localization Length Exponent, Critical Conductance Distribution and Multifractality in Hierarchical Network Models for the Quantum Hall Effect

We study hierarchical network models which have recently been introduced to approximate the Chalker-Coddington model for the integer quantum Hall effect (A.G. Galstyan and M.E. Raikh, PRB 56 1422 (1997); Arovas et al., PRB 56, 4751 (1997)). The hierarchical structure is due to a recursive method starting from a finite elementary cell. The localization-delocalization transition occurring in these models is displayed in the flow of the conductance distribution under increasing system size. We numerically determine this flow, calculate the critical conductance distribution, the critical exponent of the localization length, and the multifractal exponents of critical eigenstates.Comment: 6 pages REVTeX, 9 postscript figures and 1 postscript tabl

Polarized beam operation of the Hybrid Spectrometer at the pulsed Spallation Neutron Source

The concept of a neutron Hybrid Spectrometer (HYSPEC) combines the time-of-flight spectroscopy with the focusing Bragg optics and incorporates a polarized beam option. Here we describe the polarization analysis scheme proposed for HYSPEC and quantify its performance via the Monte-Carlo simulations. We find that the broadband supermirror-bender transmission polarizers provide reasonably good polarization analysis capability within about 8-10 meV energy window for scattered neutron energies in the thermal range up to about 25 meV.Comment: Preprint, to appear in Physica B. 10 pages, 4 figure

Newly born dentate granule neurons after pilocarpine-induced epilepsy have hilar basal dendrites with immature synapses.

Neurogenesis in the subgranular zone of the dentate gyrus persists throughout the lifespan of mammals, and the resulting newly born neurons are incorporated into existing hippocampal circuitry. Seizures increase the rate of neurogenesis in the adult rodent brain and result in granule cells in the dentate gyrus with basal dendrites. Using doublecortin (DCX) immunocytochemistry to label newly generated neurons the current study focuses on the electron microscopic features of DCX-labeled cell bodies and dendritic processes in the dentate gyrus of rats with pilocarpine-induced epilepsy. At the base of the granule cell layer clusters of cells that include up to six DCX-labeled cell bodies were observed. The cell bodies in these clusters lacked a one-to-one association with an astrocyte cell body and its processes, a relationship that is typical for newly born granule cells in control rats. Also, DCX-labeled basal dendrites in the hilus had immature synapses while those in control rats lacked synapses. These results indicate that increased neurogenesis after seizures alters the one-to-one relationship between astrocytes and DCX-labeled newly generated neurons at the base of the granule cell layer. The data also suggest that the synapses on DCX-labeled hilar basal dendrites contribute to the persistence of hilar basal dendrites on neurons born after pilocarpine-induced seizures

Transforming floundering into success

We show how logic programs with "delays" can be transformed to programs without delays in a way which preserves information concerning floundering (also known as deadlock). This allows a declarative (model-theoretic), bottom-up or goal independent approach to be used for analysis and debugging of properties related to floundering. We rely on some previously introduced restrictions on delay primitives and a key observation which allows properties such as groundness to be analysed by approximating the (ground) success set. This paper is to appear in Theory and Practice of Logic Programming (TPLP). Keywords: Floundering, delays, coroutining, program analysis, abstract interpretation, program transformation, declarative debuggingComment: Number of pages: 24 Number of figures: 9 Number of tables: non

Energy Gaps and Kohn Anomalies in Elemental Superconductors

The momentum and temperature dependence of the lifetimes of acoustic phonons in the elemental superconductors Pb and Nb was determined by resonant spin-echo spectroscopy with neutrons. In both elements, the superconducting energy gap extracted from these measurements was found to converge with sharp anomalies originating from Fermi-surface nesting (Kohn anomalies) at low temperatures. The results indicate electron many-body correlations beyond the standard theoretical framework for conventional superconductivity. A possible mechanism is the interplay between superconductivity and spin- or charge-density-wave fluctuations, which may induce dynamical nesting of the Fermi surface

Nanoscale Heat Transfer from Magnetic Nanoparticles and Ferritin in an Alternating Magnetic Field

Recent suggestions of nanoscale heat confinement on the surface of synthetic and biogenic magnetic nanoparticles during heating by radio frequency-alternating magnetic fields have generated intense interest because of the potential utility of this phenomenon for noninvasive control of biomolecular and cellular function. However, such confinement would represent a significant departure from the classical heat transfer theory. Here, we report an experimental investigation of nanoscale heat confinement on the surface of several types of iron oxide nanoparticles commonly used in biological research, using an all-optical method devoid of the potential artifacts present in previous studies. By simultaneously measuring the fluorescence of distinct thermochromic dyes attached to the particle surface or dissolved in the surrounding fluid during radio frequency magnetic stimulation, we found no measurable difference between the nanoparticle surface temperature and that of the surrounding fluid for three distinct nanoparticle types. Furthermore, the metalloprotein ferritin produced no temperature increase on the protein surface nor in the surrounding fluid. Experiments mimicking the designs of previous studies revealed potential sources of the artifacts. These findings inform the use of magnetic nanoparticle hyperthermia in engineered cellular and molecular systems