4,679 research outputs found

    System and Method for Providing Model-Based Alerting of Spatial Disorientation to a Pilot

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    A system and method monitor aircraft state parameters, for example, aircraft movement and flight parameters, applies those inputs to a spatial disorientation model, and makes a prediction of when pilot may become spatially disoriented. Once the system predicts a potentially disoriented pilot, the sensitivity for alerting the pilot to conditions exceeding a threshold can be increased and allow for an earlier alert to mitigate the possibility of an incorrect control input

    Bar coding MS2 spectra for metabolite identification

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    [Image: see text] Metabolite identifications are most frequently achieved in untargeted metabolomics by matching precursor mass and full, high-resolution MS(2) spectra to metabolite databases and standards. Here we considered an alternative approach for establishing metabolite identifications that does not rely on full, high-resolution MS(2) spectra. First, we select mass-to-charge regions containing the most informative metabolite fragments and designate them as bins. We then translate each metabolite fragmentation pattern into a binary code by assigning 1’s to bins containing fragments and 0’s to bins without fragments. With 20 bins, this binary-code system is capable of distinguishing 96% of the compounds in the METLIN MS(2) library. A major advantage of the approach is that it extends untargeted metabolomics to low-resolution triple quadrupole (QqQ) instruments, which are typically less expensive and more robust than other types of mass spectrometers. We demonstrate a method of acquiring MS(2) data in which the third quadrupole of a QqQ instrument cycles over 20 wide isolation windows (coinciding with the location and width of our bins) for each precursor mass selected by the first quadrupole. Operating the QqQ instrument in this mode yields diagnostic bar codes for each precursor mass that can be matched to the bar codes of metabolite standards. Furthermore, our data suggest that using low-resolution bar codes enables QqQ instruments to make MS(2)-based identifications in untargeted metabolomics with a specificity and sensitivity that is competitive to high-resolution time-of-flight technologies

    Investigating the relationship between HIV testing and risk behaviour in Britain: National Survey of Sexual Attitudes and Lifestyles 2000.

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    OBJECTIVES: To estimate the prevalence of, and identify factors associated with, HIV testing in Britain. DESIGN: A large, stratified probability sample survey of sexual attitudes and lifestyles. METHODS: A total of 12,110 16-44 year olds completed a computer-assisted face-to-face interview and self-interview. Self-reports of HIV testing, i.e. the timing, reasons for and location of testing, were included. RESULTS: A total of 32.4% of men and 31.7% of women reported ever having had an HIV test, the majority of whom were tested through blood donation. When screening for blood donation and pregnancy were excluded, 9.0% of men and 4.6% of women had had a voluntary confidential HIV test (VCT) in the past 5 years. However, one third of injecting drug users and men who have sex with men had a VCT in the past 5 years. VCT in the past 5 years was significantly associated with age, residence, ethnicity, self-perceived HIV risk, reporting greater numbers of sexual partners, new sexual partners from abroad, previous sexually transmitted infection diagnosis, and injecting non-prescribed drugs for men and women, and same-sex partners (men only). Whereas sexually transmitted disease clinics were important sites for VCT, general practice accounted for almost a quarter of VCT. CONCLUSION: HIV testing is relatively common in Britain; however, it remains largely associated with population-based blood donation and antenatal screening programmes. In contrast, VCT remains highly associated with high-risk (sexual or drug-injecting) behaviours or population sub-groups at high risk. Strategies to reduce undiagnosed prevalent HIV infection will require further normalization and wider uptake of HIV testing

    Are You an Innovator or Adaptor? The Impact of Cognitive Propensity on Venture Expectations and Outcomes

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    In this study we confirm the often assumed but largely untested belief that entrepreneurs think and behave differently than others. We examine a group of more than 700 nascent entrepreneurs and 400 nonentrepreneurs. We determine the entrepreneurs’ cognitive style propensity for problem solving (Innovator versus Adaptor); we compare their expectations; and, we examine the outcomes (performance and start-up) of their ventures. We find that nascent entrepreneurs are more likely to be overly optimistic Innovators, most people are Adaptors, and one’s cognitive style can indeed play a role in the initial development and outcome for the venture, but not always as expected

    Nonlocalized modulation of periodic reaction diffusion waves: The Whitham equation

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    In a companion paper, we established nonlinear stability with detailed diffusive rates of decay of spectrally stable periodic traveling-wave solutions of reaction diffusion systems under small perturbations consisting of a nonlocalized modulation plus a localized perturbation. Here, we determine time-asymptotic behavior under such perturbations, showing that solutions consist to leading order of a modulation whose parameter evolution is governed by an associated Whitham averaged equation
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