Relative Shock Effects in Mixed Powders of Calcite, Gypsum, and Quartz: A Calibration Scheme from Shock Experiments

The shock behavior of calcite and gypsum is important in understanding the Cretaceous/Tertiary event and other terrestrial impacts that contain evaporite sediments in their targets. Most interest focuses on issues of devolatilization to quantify the production of CO2 or SO2 to better understand their role in generating a temporary atmosphere and its effects on climate and biota [e.g., papers in 1,2,3,4]. Devolatilization of carbonate is also important because the dispersion and fragmentation of ejecta is strongly controlled by the expansion of large volumes of gas during the impact process as well [5,6]. Shock recovery experiments for calcite yield seemingly conflicting results: early experimental devolatilization studies [7,8,9] suggested that calcite was substantially outgassed at 30 GPa (> 50%). However, the recent petrographic work of [10,11,12] presented evidence that essentially intact calcite is recovered from 60 GPa experiments. [13] reported results of shock experiments on anhydrite, gypsum, and mixtures of those phases with silica. Their observations indicate little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another (preliminary) report of shock experiments on calcite, anhydrite, and gypsum, [14] observe calcite recrystallization when shock loaded at 61 GPa, only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa. [15] shock loaded anhydrite and quartz to a peak pressure of 60 GPa. All of the quartz grains were trans-formed to glass and the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggest that recrystallization of anhydrite grains is the result of a solid state transformation. [16] reanalyzed the calcite and anhydrite shock wave experiments of [17] using improved equations of state of porous materials and vaporized products. They determined the pressures for incipient and complete vaporization to be 32.5 and 122 GPa for anhydrite and 17.8 and 54.1 GPa for calcite, respectively, a factor of 2 to 3 lower than reported earlier by [17]

J.S. Bell's Concept of Local Causality

John Stewart Bell's famous 1964 theorem is widely regarded as one of the most important developments in the foundations of physics. It has even been described as "the most profound discovery of science." Yet even as we approach the 50th anniversary of Bell's discovery, its meaning and implications remain controversial. Many textbooks and commentators report that Bell's theorem refutes the possibility (suggested especially by Einstein, Podolsky, and Rosen in 1935) of supplementing ordinary quantum theory with additional ("hidden") variables that might restore determinism and/or some notion of an observer-independent reality. On this view, Bell's theorem supports the orthodox Copenhagen interpretation. Bell's own view of his theorem, however, was quite different. He instead took the theorem as establishing an "essential conflict" between the now well-tested empirical predictions of quantum theory and relativistic \emph{local causality}. The goal of the present paper is, in general, to make Bell's own views more widely known and, in particular, to explain in detail Bell's little-known mathematical formulation of the concept of relativistic local causality on which his theorem rests. We thus collect and organize many of Bell's crucial statements on these topics, which are scattered throughout his writings, into a self-contained, pedagogical discussion including elaborations of the concepts "beable", "completeness", and "causality" which figure in the formulation. We also show how local causality (as formulated by Bell) can be used to derive an empirically testable Bell-type inequality, and how it can be used to recapitulate the EPR argument.Comment: 19 pages, 4 figure

Experimental Shock Transformation of Gypsum to Anhydrite: A New Low Pressure Regime Shock Indicator

The shock behavior of gypsum is important in understanding the Cretaceous/Paleogene event and other terrestrial impacts that contain evaporite sediments in their targets (e.g., Mars Exploration Rover Spirit detected sulfate at Gusev crater, [1]). Most interest focuses on issues of devolatilization to quantify the production of SO2 to better understand its role in generating a temporary atmosphere and its effects on climate and biota [2,3]. Kondo and Ahrens [4] measured induced radiation emitted from single crystal gypsum shocked to 30 and 40 GPa. They observed greybody emission spectra corresponding to temperatures in the range of 3,000 to 4,000 K that are a factor of 2 to 10 times greater than calculated pressure-density energy equation of state temperatures (Hugoniot) and are high enough to melt gypsum. Chen et al. [5] reported results of shock experiments on anhydrite, gypsum, and mixtures of these phases with silica. Their observations indicated little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another report of shock experiments on calcite, anhydrite, and gypsum, Badjukov et al. [6] observed only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa but have not experimentally shocked gypsum in a step-wise manner to constrain possible incipient transformation effects. Schmitt and Hornemann [7] shock loaded anhydrite and quartz to a peak pressure of 60 GPa and report the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggested that recrystallization of anhydrite grains is the result of a solid-state transformation. They concluded that significant decomposition of anhydrite requires shock pressures higher than 60 GPa. Gupta et al. [8] reanalyzed the calcite and anhydrite shock wave experiments of Yang [9] using improved equations of state of porous materials and vaporized products. They determined the pressures for incipient and complete vaporization to be 32.5 and 122 GPa for anhydrite GPa which is a factor of 2 to 3 lower than reported earlier by Yang [9]. These studies are not in agreement regarding the onset of sulfate decomposition and documentation of shock effects in gypsum is incomplete

A Family Day program enhances knowledge about medical school culture and necessary supports

BACKGROUND: A Family Day program was implemented at Indiana University School of Medicine to educate the families and friends of in-coming medical students about the rigors of medical school and the factors that contribute to stress. METHODS: Surveys that assessed knowledge, beliefs, and attitudes about medical school were administered to participants before and after the program. RESULTS: After the program, participants showed a significant improvement in their understanding of medical school culture and the importance of support systems for medical students. Post-test scores improved by an average of 29% (P < 0.001) in each of the two years this program was administered. CONCLUSIONS: The inclusion of family members and other loved ones in pre-matriculation educational programs may serve to mitigate the stress associated with medical school by enhancing the students' social support systems

Robotic Sample Manipulator for Handling Astromaterials Inside the Geolab Microgravity Glovebox

Future human and robotic sample return missions will require isolation containment systems with strict protocols and procedures for reducing inorganic and organic contamination. Robotic handling and manipulation of astromaterials may be required for preliminary examination inside such an isolation containment system. In addition, examination of astromaterials in microgravity will require constant contact to secure samples during manipulation. The National Space Grant Foundation exploration habitat (XHab) academic innovative challenge 2012 administered through the NASA advanced exploration systems (AES) deep space habitat (DSH) project awarded funding to the University of Bridgeport team to develop an engineering design for tools to facilitate holding and handling geological samples for analysis in a microgravity glovebox environment. The Bridgeport XHab team developed a robotic arm system with a three-finger gripper that could manipulate geologic samples within the existing GeoLab glovebox integrated into NASA's DSH called the GeoLab Robotic Sample Manipulator (see fig. 1 and 2). This hardware was deployed and tested during the 2012 DSH mission operations tests [1]

A Familty Day Program Enhances Knowledge about Medical School Culture and Necessary Supports

Background. A Family Day Program was implemented at Indiana University School of Medicine to educate the families and friends of in-coming medical students about the rigors of medical school and the factors that contribute to stress. Methods. Surveys that assessed knowledge, beliefs, and attitudes about medical school were administered to participants before and after the program. Results. After the program, participants showed a significant improvement in their understanding of medical school culture and the importance of support systems for medical students. Post-test scores improved by an average of 29% (P < 0.001) in each of the two years this program was administered. Conclusions. The inclusion of family members and other loved ones in pre-matriculation educational programs may serve to mitigate the stress associated with medical school by enhancing the students' social support systems

What is unique about quality of life in Motor Neurone Disease?: A qualitative analysis.

Background: Quality of Life (QoL) is an important consequence in neurological clinical care. The debate about generic and disease specific measures of quality of life reflects uncertainty about whether there are unique aspects to understanding QoL in different diseases. If there are commonalities to different disabling neurological diseases, it may be credible to extrapolate from more common and better-studied conditions, like multiple sclerosis (MS) to rarer diseases like motor neurone disease (MND). Distinctions across neurological conditions would suggest that strategies to maximise QoL must be disease specific. Objectives: In this analysis our aim was to explore psychosocial factors affecting QoL in MND in comparison with MS. Methods: The study employed both semi-structured interviews and focus groups. Each focus group was consisted of either MND or MS. All interviews and group discussions were audio recorded and transcribed verbatim for a thematic analysis. Themes were inductively developed within a condition before they were compared across the two conditions for cross-sectional exploration. Results: Data was collected from 40 people with MND: 26 interviews (male=14; mean age= 64yrs; mean illness duration=1.6yrs); 14 in focus groups (male=9; mean age=62yrs; mean illness duration=3.5yrs); and from 61 people with MS: 43 interviews (male=16; mean age=52yrs; mean illness duration=15yrs); 18 in focus groups (male=6; mean age=47yrs; mean illness duration=9yrs). A codebook for each condition was developed for the analysis and saturation was achieved in both MND and MS. Whilst the analysis identified the same psychosocial domains to be important for QoL irrespective of disease, there was an aspect unique to MND of it being a terminal condition. Both MS and MND patients valued their lives, but MND patients recognised their shorter life expectancy and differed from MS patients because thoughts of imminent death adversely impacted QoL. Participant’s concerns about their death were not restricted to themselves, but extended to impact on significant others. The differences between MND and MS were further observed with regard to factors that were beneficial to QoL. Although the positive influence of environmental factors and spirituality were found in both conditions, additional implications of these factors were found amongst the MND group: it was found that the importance of environment included the place of death, and spirituality was described to provide hope even beyond death. Discussion and conclusions: The current study reveals complexity in ascertaining QoL across neurological diseases. Despite distinct illness trajectories, the same psychosocial factors were identified to be important for QoL in MND and MS. Nevertheless, MND as a terminal condition was found to further challenge patient’s QoL. The findings confirm the importance of addressing this aspect of the condition in addition to commonly investigated psychosocial factors

CD25+CD4+ Regulatory T Cells from the Peripheral Blood of Asymptomatic HIV-infected Individuals Regulate CD4+ and CD8+ HIV-specific T Cell Immune Responses In Vitro and Are Associated with Favorable Clinical Markers of Disease Status

Human immunodeficiency virus (HIV) disease is associated with loss of CD4+ T cells, chronic immune activation, and progressive immune dysfunction. HIV-specific responses, particularly those of CD4+ T cells, become impaired early after infection, before the loss of responses directed against other antigens; the basis for this diminution has not been elucidated fully. The potential role of CD25+CD4+ regulatory T cells (T reg cells), previously shown to inhibit immune responses directed against numerous pathogens, as suppressors of HIV-specific T cell responses was investigated. In the majority of healthy HIV-infected individuals, CD25+CD4+ T cells significantly suppressed cellular proliferation and cytokine production by CD4+ and CD8+ T cells in response to HIV antigens/peptides in vitro; these effects were cell contact dependent and IL-10 and TGF-β independent. Individuals with strong HIV-specific CD25+ T reg cell function in vitro had significantly lower levels of plasma viremia and higher CD4+: CD8+ T cell ratios than did those individuals in whom this activity could not be detected. These in vitro data suggest that CD25+CD4+ T reg cells may contribute to the diminution of HIV-specific T cell immune responses in vivo in the early stages of HIV disease