159 research outputs found

    A layered abduction model of perception: Integrating bottom-up and top-down processing in a multi-sense agent

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    A layered-abduction model of perception is presented which unifies bottom-up and top-down processing in a single logical and information-processing framework. The process of interpreting the input from each sense is broken down into discrete layers of interpretation, where at each layer a best explanation hypothesis is formed of the data presented by the layer or layers below, with the help of information available laterally and from above. The formation of this hypothesis is treated as a problem of abductive inference, similar to diagnosis and theory formation. Thus this model brings a knowledge-based problem-solving approach to the analysis of perception, treating perception as a kind of compiled cognition. The bottom-up passing of information from layer to layer defines channels of information flow, which separate and converge in a specific way for any specific sense modality. Multi-modal perception occurs where channels converge from more than one sense. This model has not yet been implemented, though it is based on systems which have been successful in medical and mechanical diagnosis and medical test interpretation

    Reducing uncertainty by using explanatory relationships

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    Explanatory relationships can be used effectively to reduce the uncertainty that remains after diagnostic hypotheses have been scored using local matching

    Response of thin-film SQUIDs to applied fields and vortex fields: Linear SQUIDs

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    In this paper we analyze the properties of a dc SQUID when the London penetration depth \lambda is larger than the superconducting film thickness d. We present equations that govern the static behavior for arbitrary values of \Lambda = \lambda^2/d relative to the linear dimensions of the SQUID. The SQUID's critical current I_c depends upon the effective flux \Phi, the magnetic flux through a contour surrounding the central hole plus a term proportional to the line integral of the current density around this contour. While it is well known that the SQUID inductance depends upon \Lambda, we show here that the focusing of magnetic flux from applied fields and vortex-generated fields into the central hole of the SQUID also depends upon \Lambda. We apply this formalism to the simplest case of a linear SQUID of width 2w, consisting of a coplanar pair of long superconducting strips of separation 2a, connected by two small Josephson junctions to a superconducting current-input lead at one end and by a superconducting lead at the other end. The central region of this SQUID shares many properties with a superconducting coplanar stripline. We calculate magnetic-field and current-density profiles, the inductance (including both geometric and kinetic inductances), magnetic moments, and the effective area as a function of \Lambda/w and a/w.Comment: 18 pages, 20 figures, revised for Phys. Rev. B, the main revisions being to denote the effective flux by \Phi rather than

    Microwave Spectroscopy

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    Contains reports on four research projects

    Correspondence: Are Cognitive Functions Localizable? Colin Camerer et al. versus Marieke van Rooij and John G. Holden

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    The Fall 2011 issue of this journal published a two-paper section on “Neuroeconomics.” One paper, by Ernst Fehr and Antonio Rangel, clearly and concisely summarized a small part of the fast-growing literature. The second paper, “It’s about Space, It’s about Time, Neuroeconomics, and the Brain Sublime,” by Marieke van Rooij and Guy Van Orden, is beautifully written and enjoyable to read, but misleading in many critical ways. A number of economists and neuroscientists working at the intersection of the two fields shared our reaction and have signed this letter, as shown below. Some of the paper’s descriptions of empirical findings and methods in neuroeconomics are incomplete, badly out of date, or flatly wrong. In studies the authors describe in detail, their skeptical interpretations have often been refuted by published data, old and new, that they overlook

    ACC/AHA/SCAI/AMA–Convened PCPI/NCQA 2013 Performance Measures for Adults Undergoing Percutaneous Coronary Intervention A Report of the American College of Cardiology/American Heart Association Task Force on Performance Measures, the Society for Cardiovascular Angiography and Interventions, the American Medical Association–Convened Physician Consortium for Performance Improvement, and the National Committee for Quality Assurance

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    Journal of the American College of Cardiology Ó 2014 by the American College of Cardiology Foundation, American Heart Association, Inc., American Medical Association, and National Committee for Quality Assurance Published by Elsevier Inc. Vol. 63, No. 7, 2014 ISSN 0735-1097/$36.00 http://dx.doi.org/10.1016/j.jacc.2013.12.003 PERFORMANCE MEASURES ACC/AHA/SCAI/AMA–Convened PCPI/NCQA 2013 Performance Measures for Adults Undergoing Percutaneous Coronary Intervention A Report of the American College of Cardiology/American Heart Association Task Force on Performance Measures, the Society for Cardiovascular Angiography and Interventions, the American Medical Association–Convened Physician Consortium for Performance Improvement, and the National Committee for Quality Assurance Developed in Collaboration With the American Association of Cardiovascular and Pulmonary Rehabilitation and Mended Hearts Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation and Mended Hearts WRITING COMMITTEE MEMBERS Brahmajee K. Nallamothu, MD, MPH, FACC, FAHA, Co-Chair*; Carl L. Tommaso, MD, FACC, FAHA, FSCAI, Co-Chairy; H. Vernon Anderson, MD, FACC, FAHA, FSCAI*; Jeffrey L. Anderson, MD, FACC, FAHA, MACP*; Joseph C. Cleveland, J R , MDz; R. Adams Dudley, MD, MBA; Peter Louis Duffy, MD, MMM, FACC, FSCAIy; David P. Faxon, MD, FACC, FAHA*; Hitinder S. Gurm, MD, FACC; Lawrence A. Hamilton, Neil C. Jensen, MHA, MBA; Richard A. Josephson, MD, MS, FACC, FAHA, FAACVPRx; David J. Malenka, MD, FACC, FAHA*; Calin V. Maniu, MD, FACC, FAHA, FSCAIy; Kevin W. McCabe, MD; James D. Mortimer, Manesh R. Patel, MD, FACC*; Stephen D. Persell, MD, MPH; John S. Rumsfeld, MD, PhD, FACC, FAHAjj; Kendrick A. Shunk, MD, PhD, FACC, FAHA, FSCAI*; Sidney C. Smith, J R , MD, FACC, FAHA, FACP{; Stephen J. Stanko, MBA, BA, AA#; Brook Watts, MD, MS *ACC/AHA Representative. ySociety of Cardiovascular Angiography and Interventions Representative. zSociety of Thoracic Surgeons Representative. xAmerican Association of Cardiovascular and Pulmonary Rehabilitation Representative. kACC/AHA Task Force on Performance Measures Liaison. {National Heart Lung and Blood Institute Representative. #Mended Hearts Representative. The measure speciïŹcations were approved by the American College of Cardiology Board of Trustees, American Heart Association Science Advisory and Coordinating Committee, in January 2013 and the American Medical Association–Physician Consortium for Performance Improvement in February 2013. This document was approved by the American College of Cardiology Board of Trustees and the American Heart Association Science Advisory and Coordinating Committee in October 2013, and the Society of Cardiovascular Angiography and Interventions in December 2013. The American College of Cardiology requests that this document be cited as follows: Nallamothu BK, Tommaso CL, Anderson HV, Anderson JL, Cleveland JC, Dudley RA, Duffy PL, Faxon DP, Gurm HS, Hamilton LA, Jensen NC, Josephson RA, Malenka DJ, Maniu CV, McCabe KW, Mortimer JD, Patel MR, Persell SD, Rumsfeld JS, Shunk KA, Smith SC, Stanko SJ, Watts B. ACC/AHA/SCAI/AMA–Convened PCPI/NCQA 2013 perfor- mance measures for adults undergoing percutaneous coronary intervention: a report of the American College of Cardiology/American Heart Association Task Force on Performance Measures, the Society for Cardiovascular Angiography and Interventions, the American Medical Association–Convened Physician Consortium for Performance Improvement, and the National Committee for Quality Assurance. J Am Coll Cardiol 2014;63:722–45. This article has been copublished in Circulation. Copies: This document is available on the World Wide Web sites of the American College of Cardiology (www.cardiosource.org) and the American Heart Asso- ciation (http://my.americanheart.org). For copies of this document, please contact Elsevier Inc. Reprint Department, fax (212) 633-3820, e-mail [email protected]. Permissions: Multiple copies, modiïŹcation, alteration, enhancement, and/or distribution of this document are not permitted without the express permission of the American College of Cardiology. Requests may be completed online via the Elsevier site (http://www.elsevier.com/authors/obtaining- permission-to-re-use-elsevier-material). This Physician Performance Measurement Set (PPMS) and related data speciïŹcations were developed by the Physician Consortium for Performance Improvement (the Consortium), including the American College of Cardiology (ACC), the American Heart Association (AHA), and the American Medical Association (AMA), to facilitate quality-improvement activities by physicians. The performance measures contained in this PPMS are not clinical guidelines, do not establish a standard of medical care, and have not been tested for all potential applications. Although copyrighted, they can be reproduced and distributed, without modiïŹcation, for noncommercial purposesdfor example, use by health care pro

    The Demise of Islet Allotransplantation in the US: A Call for an Urgent Regulatory Update The ISLETS FOR US Collaborative

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    Islet allotransplantation in the United States (US) is facing an imminent demise. Despite nearly three decades of progress in the field, an archaic regulatory framework has stymied US clinical practice. Current regulations do not reflect the state-of-the-art in clinical or technical practices. In the US, islets are considered biologic drugs and more than minimally manipulated human cell and tissue products (HCT/Ps). Across the world, human islets are appropriately defined as minimally manipulated tissue which has led to islet transplantation becoming a standard-of-care procedure for patients with type 1 diabetes mellitus and problematic hypoglycemia. As a result of the outdated US regulations, only eleven patients underwent allo-ITx in the US between 2011-2016 and all in the setting of a clinical trial. Herein, we describe the current regulations pertaining to islet transplantation in the United States. We explore the progress which has been made in the field and demonstrate why the regulatory framework must be updated to both, better reflect our current clinical practice and to deal with upcoming challenges. We propose specific updates to current regulations which are required for the renaissance of ethical, safe, effective, and affordable allo-ITx in the United States

    Magnesia-Based Cements: A Journey of 150 Years, and Cements for the Future?

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    This review examines the detailed chemical insights that have been generated through 150 years of work worldwide on magnesium-based inorganic cements, with a focus on both scientific and patent literature. Magnesium carbonate, phosphate, silicate-hydrate, and oxysalt (both chloride and sulfate) cements are all assessed. Many such cements are ideally suited to specialist applications in precast construction, road repair, and other fields including nuclear waste immobilization. The majority of MgO-based cements are more costly to produce than Portland cement because of the relatively high cost of reactive sources of MgO and do not have a sufficiently high internal pH to passivate mild steel reinforcing bars. This precludes MgO-based cements from providing a large-scale replacement for Portland cement in the production of steel-reinforced concretes for civil engineering applications, despite the potential for CO2 emissions reductions offered by some such systems. Nonetheless, in uses that do not require steel reinforcement, and in locations where the MgO can be sourced at a competitive price, a detailed understanding of these systems enables their specification, design, and selection as advanced engineering materials with a strongly defined chemical basis

    Cardiac electrophysiologic interactions of bepridil, a new calcium antagonist, with enflurane, halothane, and isoflurane

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    Bepridil is an investigational calcium antagonist that also has fast sodium channel blocking and antidysrhythmic properties. In the present study, the potential interactions of bepridil with volatile anesthetics on cardiac electrophysiologic parameters were evaluated ] in open-chest dogs. Twenty-four dogs anesthetized with enflurane (n = 6), halothane (n = 6), isoflurane (n = 6), or chloralose (n = 6) received 2.5 mg/kg of bepridil intravenously (IV). Twenty-five additional dogs anesthetized with enflurane (n = 7), halothane (n = 6), isoflurane (n = 6), or chloralose (n = 6), received bepridil, 5.0 mg/kg, IV. Dogs anesthetized with cloralose served as controls. Cardiac electrophysiologic parameters were measured after the dogs were anesthetized and were repeated 5, 15, 30, 45, and 60 minutes after bepridil infusion. Plasma bepridil concentrations were also determined at the above time points. Synergy between bepridil and enflurane was demonstrated in the following cardiac electrophysiologic parameters: depression of sinus node function as evidenced by severe depression of sinus node automaticity and conduction; depression of atrioventricular function as evidenced by prolongation of the atrial--His bundle interval and the Wenckebach R-R interval; and, prolongation of the atrial effective refractory period. No synergy was demonstrated between bepridil and halothane or isoflurane when compared to bepridil's effects during chloralose anesthesia. It is concluded that significant synergistic cardiac electrophysiologic effects exist between bepridil and enflurane in dogs. It is recommended that caution be used when anesthetizing patients receiving bepridil with enflurane until human data on the use of this combination of pharmacologic agents is available.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27283/1/0000299.pd

    Food Insecurity Prevalence Across Diverse Sites During COVID-19: A Year of Comprehensive Data

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    Key Findings NFACT includes 18 study sites in 15 states as well as a national poll, collectively representing a sample size of more than 26,000 people. Some sites have implemented multiple survey rounds, here we report results from 22 separate surveys conducted during the year since the COVID-19 pandemic began in March 2020. 18 out of 19 surveys in 14 sites with data for before and since the pandemic began found an increase in food insecurity since the start of the COVID-19 pandemic as compared to before the pandemic. In nearly all surveys (18/19) that measured food insecurity both before and during the pandemic, more Black, Indigenous, and People of Color (BIPOC) were classified as food insecure during the pandemic as compared to before it began. Prevalence of food insecurity for BIPOC respondents was higher than the overall population in the majority of surveys (19/20) sampling a general population. In almost all surveys (21/22), the prevalence of food insecurity for households with children was higher than the overall prevalence of food insecurity. Food insecurity prevalence was higher for households experiencing a negative job impact during the pandemic (i.e. job loss, furlough, reduction in hours) in nearly all surveys and study sites (21/22). Food insecurity prevalence in most sites was significantly higher before COVID-19 than estimates from that time period. Reporting a percent change between pre and during COVID-19 prevalence may provide additional information about the rate of change in food insecurity since the start of the pandemic, which absolute prevalence of food insecurity may not capture. Results highlight consistent trends in food insecurity outcomes since the start of the COVID-19 pandemic, across diverse study sites, methodological approaches, and time
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