2,418 research outputs found

    Comments on "Limits on Dark Matter Using Ancient Mica"

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    To appear in Phys. Rev. Lett. together with the author's Reply.Comment: Compressed PostScript (filename.ps.Z), 3 pages, no figure

    Local ISM 3D Distribution and Soft X-ray Background Inferences for Nearby Hot Gas

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    Three-dimensional (3D) interstellar medium (ISM) maps can be used to locate not only interstellar (IS) clouds, but also IS bubbles between the clouds that are blown by stellar winds and supernovae, and are filled by hot gas. To demonstrate this, and to derive a clearer picture of the local ISM, we compare our recent 3D IS dust distribution maps to the ROSAT diffuse Xray background maps after removal of heliospheric emission. In the Galactic plane, there is a good correspondence between the locations and extents of the mapped nearby cavities and the soft (0.25 keV) background emission distribution, showing that most of these nearby cavities contribute to this soft X-ray emission. Assuming a constant dust to gas ratio and homogeneous 106 K hot gas filling the cavities, we modeled in a simple way the 0.25 keV surface brightness along the Galactic plane as seen from the Sun, taking into account the absorption by the mapped clouds. The data-model comparison favors the existence of hot gas in the solar neighborhood, the so-called Local Bubble (LB). The inferred mean pressure in the local cavities is found to be approx.9,400/cu cm K, in agreement with previous studies, providing a validation test for the method. On the other hand, the model overestimates the emission from the huge cavities located in the third quadrant. Using CaII absorption data, we show that the dust to CaII ratio is very small in those regions, implying the presence of a large quantity of lower temperature (non-X-ray emitting) ionized gas and as a consequence a reduction of the volume filled by hot gas, explaining at least part of the discrepancy. In the meridian plane, the two main brightness enhancements coincide well with the LB's most elongated parts and chimneys connecting the LB to the halo, but no particular nearby cavity is found towards the enhancement in the direction of the bright North Polar Spur (NPS) at high latitude. We searched in the 3D maps for the source regions of the higher energy (0.75 keV) enhancements in the fourth and first quadrants. Tunnels and cavities are found to coincide with the main bright areas, however no tunnel nor cavity is found to match the low-latitude b > or approx. 8deg, brightest part of the NPS. In addition, the comparison between the 3D maps and published spectral data favors a NPS central source region location beyond 230 pc, i.e. at larger distance than usually considered. Those examples illustrate the potential use of more detailed 3D distributions of the nearby ISM for the interpretation of the diffuse soft X-ray background

    Psychopathy and impulsivity: The relationship of psychopathy to different aspects of UPPS-P impulsivity

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    Impulsivity is thought to be a major component of psychopathy. However, impulsivity is a multi-faceted concept, and different facets may have differential relationships to psychopathy. We measured impulsivity via the UPPS-P in a sample of prisoners and in patients in a personality disorder service resident in secure psychiatric care. Psychopathy in the prison sample was measured via the clinician-rated Psychopathy Checklist: Screening Version and in the patients via the Psychopathy Checklist-Revised. We found that the Lifestyle/Antisocial factor (Factor 2) was associated with acting rashly when emotional (Negative Urgency and Positive Urgency). However, the Interpersonal/Affective factor (Factor 1) was associated with reduced impulsivity in the domains of premeditation and perseverance, and its unique variance was also associated with less rash behaviour. The Interpersonal facet (Facet 1) was particularly associated with reduced impulsivity. The results show that individuals with high Interpersonal traits of psychopathy can plan carefully and are persistent in their goals. This may underpin instrumental violence and criminal behaviour. Thus, a simple unitary understanding of the relationship between psychopathy and impulsivity may not be valid and may distort the multifaceted relationship between the two concepts that could assist in the assessment and management of psychopathic offenders

    Self-esteem, narcissism, and aggression: different types of self-esteem predict different types of aggression

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    The aim of this study was to examine the relationship between self-esteem, narcissism, and measures of proactive and reactive aggression in two large community samples of young adults from two countries (the United Kingdom and Malaysia). Self-esteem and narcissism were measured through the Multidimensional Self-Esteem Inventory and the Narcissistic Personality Inventory, whereas aggression was measured by the Reactive–Proactive Aggression Questionnaire in 501 young adults with approximately equal numbers of men and women. In both countries, low levels of self-esteem were associated with reactive aggression while high levels of narcissism were associated with proactive aggression. Although this pattern was similar for both genders, the associations between both types of self-evaluation and proactive aggression were greater for men. The results suggest that people with low self-esteem are prone to greater reactive aggression due to anger and hostility, whereas those with high levels of narcissism can act with deliberate, planned aggression to achieve a goal. These effects appear stable across gender and culture

    Psychopathy and impulsivity: The relationship of psychopathy to different aspects of UPPS-P impulsivity

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    Impulsivity is thought to be a major component of psychopathy. However, impulsivity is a multi-faceted concept, and different facets may have differential relationships to psychopathy. We measured impulsivity via the UPPS-P in a sample of prisoners and in patients in a personality disorder service resident in secure psychiatric care. Psychopathy in the prison sample was measured via the clinician-rated Psychopathy Checklist: Screening Version and in the patients via the Psychopathy Checklist-Revised. We found that the Lifestyle/Antisocial factor (Factor 2) was associated with acting rashly when emotional (Negative Urgency and Positive Urgency). However, the Interpersonal/Affective factor (Factor 1) was associated with reduced impulsivity in the domains of premeditation and perseverance, and its unique variance was also associated with less rash behaviour. The Interpersonal facet (Facet 1) was particularly associated with reduced impulsivity. The results show that individuals with high Interpersonal traits of psychopathy can plan carefully and are persistent in their goals. This may underpin instrumental violence and criminal behaviour. Thus, a simple unitary understanding of the relationship between psychopathy and impulsivity may not be valid and may distort the multifaceted relationship between the two concepts that could assist in the assessment and management of psychopathic offenders

    The Supergiant Shell LMC2: II. Physical Properties of the 10^6 K Gas

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    LMC2 has the highest X-ray surface brightness of all know supergiant shells in the Large Magellanic Cloud (LMC). The X-ray emission peaks within the ionized filaments that define the shell boundary, but also extends beyond the southern border of LMC2 as an X-ray bright spur. ROSAT HRI images reveal the X-ray emission from LMC2 and the spur to be truly diffuse, indicating a hot plasma origin. We have obtained ROSAT PSPC and ASCA SIS spectra to study the physical conditions of the hot gas interior to LMC2 and the spur. Raymond-Smith thermal plasma model fits to the X-ray spectra, constrained by HI 21-cm emission-line measurements of the column density, show the plasma temperature of the hot gas interior of LMC2 to be kT = 0.1 - 0.7 keV and of the spur to be kT = 0.1 - 0.5 keV. We have compared the physical conditions of the hot gas interior to LMC2 with those of other supergiant shells, superbubbles, and supernova remnants (SNRs) in the LMC. We find that our derived electron densities for the hot gas inside LMC2 is higher than the value determined for the supergiant shell LMC4, comparable to the value determined for the superbubble N11, and lower than the values determined for the superbubble N44 and a number of SNRs.Comment: 29 pages, 5 figures, to be published in Ap

    Enhanced emotional response to both negative and positive images in post-traumatic stress disorder: Evidence from pupillometry

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    Post-traumatic stress disorder (PTSD) is characterised by alterations in the function of the autonomic nervous system. However, it is unclear if this dysfunction is threat-related or related to arousing stimuli in general. Pupillometry offers a simple non-invasive measure of ANS activity that can separate parasympathetic and sympathetic arousal. Participants viewed images with emotional or neutral content: 20 met diagnostic criteria for PTSD, 28 were trauma-exposed (but with no PTSD), and 17 were controls. Initial pupil constriction (a marker of parasympathetic function) was reduced for the PTSD group, while dilation due to the emotional content of the image (a marker of sympathetic activity) was greater in the PTSD group. Individuals with PTSD demonstrated enhanced physiological arousal to both threat-related and positive images. The results suggest reduced parasympathetic arousal and increased sympathetic arousal in the autonomic nervous system, which has been linked to a range of adverse health outcomes in PTSD

    A review of hot-melt extrusion: process technology to pharmaceutical products [Review article]

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    Over the last three decades industrial adaptability has allowed hot-melt extrusion (HME) to gain wide acceptance and has already established its place in the broad spectrum of manufacturing operations and pharmaceutical research developments. HME has already been demonstrated as a robust, novel technique to make solid dispersions in order to provide time controlled, modified, extended, and targeted drug delivery resulting in improved bioavailability as well as taste masking of bitter active pharmaceutical ingredients (APIs). This paper reviews the innumerable benefits of HME, based on a holistic perspective of the equipment, processing technologies to the materials, novel formulation design and developments, and its varied applications in oral drug delivery systems

    X-ray observations of the galaxy cluster Abell 2029 to the virial radius

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    We present Suzaku observations of the galaxy cluster Abell 2029, which exploit Suzaku's low particle background to probe the ICM to radii beyond those possible with previous observations (reaching out to the virial radius), and with better azimuthal coverage. We find significant anisotropies in the temperature and entropy profiles, with a region of lower temperature and entropy occurring to the south east, possibly the result of accretion activity in this direction. Away from this cold feature, the thermodynamic properties are consistent with an entropy profile which rises, but less steeply than the predictions of purely gravitational hierarchical structure formation. Excess emission in the northern direction can be explained due to the overlap of the emission from the outskirts of Abell 2029 and nearby Abell 2033 (which is at slightly higher redshift). These observations suggest that the assumptions of spherical symmetry and hydrostatic equilibrium break down in the outskirts of galaxy clusters, which poses challenges for modelling cluster masses at large radii and presents opportunities for studying the formation and accretion history of clusters.Comment: 15 pages, 14 figures. Accepted for publication in the Monthly Notices of the Royal Astronomical Societ
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