6,493 research outputs found

    Killing without collateral damage: new hope for sepsis therapy.

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    Dr Proudfoot is a Wellcome Trust Clinical Research Training Fellow and Dr Summers is a Wellcome Trust Postdoctoral Clinical Training Fellow.This is the accepted manuscript version. The final version is available from NPG at http://www.nature.com/icb/journal/v92/n9/full/icb201473a.html

    Poisson-de Rham homology of hypertoric varieties and nilpotent cones

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    We prove a conjecture of Etingof and the second author for hypertoric varieties, that the Poisson-de Rham homology of a unimodular hypertoric cone is isomorphic to the de Rham cohomology of its hypertoric resolution. More generally, we prove that this conjecture holds for an arbitrary conical variety admitting a symplectic resolution if and only if it holds in degree zero for all normal slices to symplectic leaves. The Poisson-de Rham homology of a Poisson cone inherits a second grading. In the hypertoric case, we compute the resulting 2-variable Poisson-de Rham-Poincare polynomial, and prove that it is equal to a specialization of an enrichment of the Tutte polynomial of a matroid that was introduced by Denham. We also compute this polynomial for S3-varieties of type A in terms of Kostka polynomials, modulo a previous conjecture of the first author, and we give a conjectural answer for nilpotent cones in arbitrary type, which we prove in rank less than or equal to 2.Comment: 25 page

    The hypertoric intersection cohomology ring

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    We present a functorial computation of the equivariant intersection cohomology of a hypertoric variety, and endow it with a natural ring structure. When the hyperplane arrangement associated with the hypertoric variety is unimodular, we show that this ring structure is induced by a ring structure on the equivariant intersection cohomology sheaf in the equivariant derived category. The computation is given in terms of a localization functor which takes equivariant sheaves on a sufficiently nice stratified space to sheaves on a poset.Comment: Significant revisions in Section 5, with several corrected proof

    Measuring Hacking Ability Using a Conceptual Expertise Task

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    Hackers pose a continuous and unrelenting threat to organizations. Industry and academic researchers alike can benefit from a greater understanding of how hackers engage in criminal behavior. A limiting factor of hacker research is the inability to verify that self-proclaimed hackers participating in research actually possess their purported knowledge and skills. This paper presents current work in developing and validating a conceptual-expertise based tool that can be used to discriminate between novice and expert hackers. The implications of this work are promising since behavioral information systems researchers operating in the information security space will directly benefit from the validation of this tool. Keywords: hacker ability, conceptual expertise, skill measuremen

    Noninvasive vagus nerve stimulation alters neural response and physiological autonomic tone to noxious thermal challenge.

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    The mechanisms by which noninvasive vagal nerve stimulation (nVNS) affect central and peripheral neural circuits that subserve pain and autonomic physiology are not clear, and thus remain an area of intense investigation. Effects of nVNS vs sham stimulation on subject responses to five noxious thermal stimuli (applied to left lower extremity), were measured in 30 healthy subjects (n = 15 sham and n = 15 nVNS), with fMRI and physiological galvanic skin response (GSR). With repeated noxious thermal stimuli a group × time analysis showed a significantly (p < .001) decreased response with nVNS in bilateral primary and secondary somatosensory cortices (SI and SII), left dorsoposterior insular cortex, bilateral paracentral lobule, bilateral medial dorsal thalamus, right anterior cingulate cortex, and right orbitofrontal cortex. A group × time × GSR analysis showed a significantly decreased response in the nVNS group (p < .0005) bilaterally in SI, lower and mid medullary brainstem, and inferior occipital cortex. Finally, nVNS treatment showed decreased activity in pronociceptive brainstem nuclei (e.g. the reticular nucleus and rostral ventromedial medulla) and key autonomic integration nuclei (e.g. the rostroventrolateral medulla, nucleus ambiguous, and dorsal motor nucleus of the vagus nerve). In aggregate, noninvasive vagal nerve stimulation reduced the physiological response to noxious thermal stimuli and impacted neural circuits important for pain processing and autonomic output

    Sleight of Hand: Identifying Concealed Information by Monitoring Mouse-Cursor Movements

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    Organizational members who conceal information about adverse behaviors present a substantial risk to that organization. Yet the task of identifying who is concealing information is extremely difficult, expensive, error-prone, and time-consuming. We propose a unique methodology for identifying concealed information: measuring people’s mouse-cursor movements in online screening questionnaires. We theoretically explain how mouse-cursor movements captured during a screening questionnaire differ between people concealing information and truth tellers. We empirically evaluate our hypotheses using an experiment during which people conceal information about a questionable act. While people completed the screening questionnaire, we simultaneously collected mouse-cursor movements and electrodermal activity—the primary sensor used for polygraph examinations—as an additional validation of our methodology. We found that mouse-cursor movements can significantly differentiate between people concealing information and people telling the truth. Mouse-cursor movements can also differentiate between people concealing information and truth tellers on a broader set of comparisons relative to electrodermal activity. Both mouse-cursor movements and electrodermal activity have the potential to identify concealed information, yet mouse-cursor movements yielded significantly fewer false positives. Our results demonstrate that analyzing mouse-cursor movements has promise for identifying concealed information. This methodology can be automated and deployed online for mass screening of individuals in a natural setting without the need for human facilitators. Our approach further demonstrates that mouse-cursor movements can provide insight into the cognitive state of computer users

    Providing healthcare for people with chronic illness: the views of Australian GPs

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    The document attached has been archived with permission from the editor of the Medical Journal of Australia (26 April 2007). An external link to the publisher’s copy is included.OBJECTIVES: To explore general practitioners' views on chronic-disease care: the difficulties and rewards, the needs of patients, the impact of government incentive payments, and the changes needed to improve chronic-disease management. DESIGN: Qualitative study, involving semi-structured questions administered to 10 focus groups of GPs, conducted from April to October 2002. PARTICIPANTS AND SETTING: 54 GPs from both urban and rural practices in New South Wales and South Australia. RESULTS: Consistent themes emerged about the complex nature of chronic-disease management, the tension between patients' and GPs' goals for care, the time-consuming aspects of care (exacerbated by federal government requirements), and the conflicting pressures that prevent GPs engaging in structured multidisciplinary care (ie, team-based care involving systems for patient monitoring, recall, and care planning). CONCLUSIONS: Structured multidisciplinary care for people with chronic conditions can be difficult to provide. Barriers include the lack of fit between systems oriented towards acute care and the requirements of chronic-disease care, and between bureaucratic, inflexible structures and the complex, dynamic nature of GP–patient relationships. These problems are exacerbated by administrative pressures associated with federal government initiatives to improve chronic-illness management. Changes are needed in both policies and attitudes to enable GPs to move from episodic care to providing structured long-term care as part of a multidisciplinary team.John Oldroyd, Judith Proudfoot, Fernando A Infante, Gawaine Powell Davies, Tanya Bubner, Chris Holton, Justin J Beilby and Mark F Harri

    A New Scintillator Tile/Fiber Preshower Detector for the CDF Central Calorimeter

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    A detector designed to measure early particle showers has been installed in front of the central CDF calorimeter at the Tevatron. This new preshower detector is based on scintillator tiles coupled to wavelength-shifting fibers read out by multi-anode photomultipliers and has a total of 3,072 readout channels. The replacement of the old gas detector was required due to an expected increase in instantaneous luminosity of the Tevatron collider in the next few years. Calorimeter coverage, jet energy resolution, and electron and photon identification are among the expected improvements. The final detector design, together with the R&D studies that led to the choice of scintillator and fiber, mechanical assembly, and quality control are presented. The detector was installed in the fall 2004 Tevatron shutdown and started collecting colliding beam data by the end of the same year. First measurements indicate a light yield of 12 photoelectrons/MIP, a more than two-fold increase over the design goals.Comment: 5 pages, 10 figures (changes are minor; this is the final version published in IEEE-Trans.Nucl.Sci.
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