474 research outputs found

    Doing Without Believing:Intellectualism, Knowledge-How, and Belief-Attribution

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    Combining Search, Social Media, and Traditional Data Sources to Improve Influenza Surveillance

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    We present a machine learning-based methodology capable of providing real-time ("nowcast") and forecast estimates of influenza activity in the US by leveraging data from multiple data sources including: Google searches, Twitter microblogs, nearly real-time hospital visit records, and data from a participatory surveillance system. Our main contribution consists of combining multiple influenza-like illnesses (ILI) activity estimates, generated independently with each data source, into a single prediction of ILI utilizing machine learning ensemble approaches. Our methodology exploits the information in each data source and produces accurate weekly ILI predictions for up to four weeks ahead of the release of CDC's ILI reports. We evaluate the predictive ability of our ensemble approach during the 2013-2014 (retrospective) and 2014-2015 (live) flu seasons for each of the four weekly time horizons. Our ensemble approach demonstrates several advantages: (1) our ensemble method's predictions outperform every prediction using each data source independently, (2) our methodology can produce predictions one week ahead of GFT's real-time estimates with comparable accuracy, and (3) our two and three week forecast estimates have comparable accuracy to real-time predictions using an autoregressive model. Moreover, our results show that considerable insight is gained from incorporating disparate data streams, in the form of social media and crowd sourced data, into influenza predictions in all time horizon

    The influence of modified gravitational fields on motions of Keplerian objects at the far-edge of the Solar System

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    We investigated the impact of three different modifications of Newtonian gravity on motions of Keplerian objects within the Solar System. These objects are located at distances of the order of the distance to the Oort cloud. With these three modifications we took into account a heliocentric Dark-Matter halo as was indicated by Diemand et al, Modified Newtonian Dynamics (MOND) and a vacuum-induced force due to a locally negative cosmological constant Λ−\Lambda_- derived by Fahr & Siewert. In gravitationally bound systems it turns out that all three modifications deliver the same qualitative results: Initially circular orbits for the pure Newtonian case are forced to convert into ellipses with perihelion migrations. The quantitative consideration, however, of the orbital parameters showed strong differences between MOND on the one side, and Dark-Matter and Λ−\Lambda_- effects on the other side.Comment: 9 pages, 16 figures, MNRAS accepte

    Biophotonic Tools in Cell and Tissue Diagnostics.

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    In order to maintain the rapid advance of biophotonics in the U.S. and enhance our competitiveness worldwide, key measurement tools must be in place. As part of a wide-reaching effort to improve the U.S. technology base, the National Institute of Standards and Technology sponsored a workshop titled "Biophotonic tools for cell and tissue diagnostics." The workshop focused on diagnostic techniques involving the interaction between biological systems and photons. Through invited presentations by industry representatives and panel discussion, near- and far-term measurement needs were evaluated. As a result of this workshop, this document has been prepared on the measurement tools needed for biophotonic cell and tissue diagnostics. This will become a part of the larger measurement road-mapping effort to be presented to the Nation as an assessment of the U.S. Measurement System. The information will be used to highlight measurement needs to the community and to facilitate solutions

    Safety and tolerability of SRX246, a vasopressin 1a antagonist, in irritable Huntington\u27s disease patients—A randomized phase 2 clinical trial

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    SRX246 is a vasopressin (AVP) 1a receptor antagonist that crosses the blood-brain barrier. It reduced impulsive aggression, fear, depression and anxiety in animal models, blocked the actions of intranasal AVP on aggression/fear circuits in an experimental medicine fMRI study and demonstrated excellent safety in Phase 1 multiple-ascending dose clinical trials. The present study was a 3-arm, multicenter, randomized, placebo-controlled, double-blind, 12-week, dose escalation study of SRX246 in early symptomatic Huntington\u27s disease (HD) patients with irritability. Our goal was to determine whether SRX246 was safe and well tolerated in these HD patients given its potential use for the treatment of problematic neuropsychiatric symptoms. Participants were randomized to receive placebo or to escalate to 120 mg twice daily or 160 mg twice daily doses of SRX246. Assessments included standard safety tests, the Unified Huntington\u27s Disease Rating Scale (UHDRS), and exploratory measures of problem behaviors. The groups had comparable demographics, features of HD and baseline irritability. Eighty-two out of 106 subjects randomized completed the trial on their assigned dose of drug. One-sided exact-method confidence interval tests were used to reject the null hypothesis of inferior tolerability or safety for each dose group vs. placebo. Apathy and suicidality were not affected by SRX246. Most adverse events in the active arms were considered unlikely to be related to SRX246. The compound was safe and well tolerated in HD patients and can be moved forward as a candidate to treat irritability and aggression

    The Azomethine Imine Route to Guanidines. Total Synthesis of (+)-Saxitoxin

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    Azomethine imines may be readily generated through the interaction of aldehyde aeetals with earboxylie acid hydrazides. These reaetions are most highly favored in pollar aprotie solvents and aeid eatalysis is required. With suitably funetionalized hydrazides these substanees undergo a faeile intramolecular addition to give fused-ring pyrazolidine derivati ves. As a part of these studies, (± )-Saxitoxin (7), the paralytie agent of the Alaska butter elam Saxidomas giganteus, has been synthesized in a totally stereospecific fashion through a sequenee involving as the key steps: (a) intramolecular 1,3-dipolar addition of an azomethine imine to a 2-imidazolone; (b) reductive cleavage of the resulting pyrazolidine ring followed by intramoleeular acylation; and (c) final elaboration of a bis-pseudourea to the requisite guanidine functionality
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