2,488 research outputs found

    <theoretical studies on the relationship between the thermionic work function of re- fractory intermetallic compounds and their electronic and crystal structures< progress report letter, 1 jul. - 31 dec. 1964

    Get PDF
    Thermionic work function of refractory metallic compounds and electronic and crystal structure - emissivity measurement and diode fabricatio

    The Relationship Among the Contributing Factors to Anorexia Nervosa

    Get PDF
    Anorexia nervosa is now being viewed as a multidimensional disorder in terms of predisposing factors such as genetics, biology, and environment. Results from twin studies suggest that part of a susceptibility to AN may lie in genetic factors (Holland et al., 1984, 1988; Treasure and Holland, 1991). However, the nature of a genetic contribution, if any, remains unclear. Neurochemical alterations have been found to be associated with AN, but it is difficult to assess what role these neurochemical changes play in the etiology of the disorder since they may precipitate, accompany, or follow weight loss (Fava et al., 1989). Abnormal family interactions (Humphrey et al., 1986; Kog and Vandereycken, 1989) and cultural practices of diet and exercise (Epling and Pierce, 1988) have also been implicated as contributing factors to AN. The cultural and familial models are deficient, however, in that they do not account for individual susceptibility (Treasure and Campbell, 1994). Further, issues of nature versus nurture have not been fully examined in family models. The lack of understanding in the exact nature and role of the contribution of these factors to the development of AN, and the further complex relationship among these factors present a problem for researchers in understanding the aetiology of the disorder

    Three-dimensional coronal slow modes: toward three-dimensional seismology

    Get PDF
    On 2008 January 10, the twin Solar Terrestrial Relations Observatory (STEREO) A and B spacecraft conducted a high time cadence study of the solar corona with the Extreme UltraViolet Imager (EUVI) instruments with the aim of investigating coronal dynamics. Observations of the three-dimensional propagation of waves within active region coronal loops and a measurement of the true coronal slow mode speed are obtained. Intensity oscillations with a period of approximately 12 minutes are observed to propagate outwards from the base of a loop system, consistent with the slow magnetoacoustic mode. A novel analysis technique is applied to measure the wave phase velocity in the observations of the A and B spacecraft. These stereoscopic observations are used to infer the three-dimensional velocity vector of the wave propagation, with an inclination of 37 +- 6 deg to the local normal and a magnitude of 132 +- 9 and 132 +- 11 km s-1, giving the first measurement of the true coronal longitudinal slow mode speed, and an inferred temperature of 0.84 +- 12 MK and 0.84 +- 15 MK

    The Wages of Crying Life: What States Must Do to Protect Children After the Fall of Roe

    Get PDF
    In the post-Roe world, can a state rationally claim that the value of human life justifies the imposition of abortion bans but does not demand that a state protect the vulnerable young who are “born human beings”—commonly called “minors” or “children”—and are entitled to protection under a state’s laws? This essay advances the claim that it cannot. This essay asks that those who say they are “Pro-life” in politics and law demonstrate that they protect vulnerable life beyond the abortion context, and that they do so in the most minimal fashion: through a demonstrated commitment to protecting the basic welfare of the most vulnerable children. The proposed “wage for crying life” (a play on John Hart Ely’s famous phrase) is a set of remedies for the sake of rationality and for other obvious public ends to be paid by multiple stakeholders. These stakeholders, both public and private, must participate in measuring and meeting basic standards for ensuring the protection of children from child abuse and neglect in a jurisdiction before that jurisdiction may rationally ban abortion. Using the authors’ home state of New Hampshire as a case study, this essay offers an initial application of the proposed broad framework to show how one state’s record of permitting massive child abuse prevents it from rationally claiming the “Pro-Life” status it claims its abortion ban achieves

    A Search for Ultra-High Energy Counterparts to Gamma-Ray Bursts

    Get PDF
    A small air shower array operating over many years has been used to search for ultra-high energy (UHE) gamma radiation (50\geq 50 TeV) associated with gamma-ray bursts (GRBs) detected by the BATSE instrument on the Compton Gamma-Ray Observatory (CGRO). Upper limits for a one minute interval after each burst are presented for seven GRBs located with zenith angles θ<20\theta < 20^{\circ}. A 4.3σ4.3\sigma excess over background was observed between 10 and 20 minutes following the onset of a GRB on 11 May 1991. The confidence level that this is due to a real effect and not a background fluctuation is 99.8\%. If this effect is real then cosmological models are excluded for this burst because of absorption of UHE gamma rays by the intergalactic radiation fields.Comment: 4 pages LaTeX with one postscript figure. This version does not use kluwer.sty and will allow automatic postscript generatio

    Bioreactors in Tissue Engineering

    Get PDF

    Evolution of virulence: triggering host inflammation allows invading pathogens to exclude competitors.

    Get PDF
    Virulence is generally considered to benefit parasites by enhancing resource-transfer from host to pathogen. Here, we offer an alternative framework where virulent immune-provoking behaviours and enhanced immune resistance are joint tactics of invading pathogens to eliminate resident competitors (transferring resources from resident to invading pathogen). The pathogen wins by creating a novel immunological challenge to which it is already adapted. We analyse a general ecological model of 'proactive invasion' where invaders not adapted to a local environment can succeed by changing it to one where they are better adapted than residents. However, the two-trait nature of the 'proactive' strategy (provocation of, and adaptation to environmental change) presents an evolutionary conundrum, as neither trait alone is favoured in a homogenous host population. We show that this conundrum can be resolved by allowing for host heterogeneity. We relate our model to emerging empirical findings on immunological mediation of parasite competition

    Comprehensive Observations of a Solar Minimum CME with STEREO

    Full text link
    We perform the first kinematic analysis of a CME observed by both imaging and in situ instruments on board STEREO, namely the SECCHI, PLASTIC, and IMPACT experiments. Launched on 2008 February 4, the CME is tracked continuously from initiation to 1 AU using the SECCHI imagers on both STEREO spacecraft, and is then detected by the PLASTIC and IMPACT particle and field detectors on board STEREO-B. The CME is also detected in situ by ACE and SOHO/CELIAS at Earth's L1 Lagrangian point. The CME hits STEREO-B, ACE, and SOHO on 2008 February 7, but misses STEREO-A entirely. This event provides a good example of just how different the same event can look when viewed from different perspectives. We also demonstrate many ways in which the comprehensive and continuous coverage of this CME by STEREO improves confidence in our assessment of its kinematic behavior, with potential ramifications for space weather forecasting. The observations provide several lines of evidence in favor of the observable part of the CME being narrow in angular extent, a determination crucial for deciding how best to convert observed CME elongation angles from Sun-center to actual Sun-center distances.Comment: 27 pages, 10 figures, AASTEX v5.2, accepted by Ap
    corecore