168 research outputs found

    An augmented filled function for global nonlinear integer optimization

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    The problem of finding global minima of nonlinear discrete functions arises in many fields of practical matters. In recent years, methods based on discrete filled functions have become popular as ways of solving these sort of problems. However, they rely on the steepest descent method for local searches. Here, we present an approach that does not depend on a particular local optimization method, and a new discrete filled function with the useful property that a good continuous global optimization algorithm applied to it leads to an approximation of the solution of the nonlinear discrete problem (Theorem 4). Numerical results are given showing the efficiency of the new approach.Fil: Di Mauro Aparicio, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; ArgentinaFil: Scolnik, Hugo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; Argentin

    Racial Disparities in Intravenous Recombinant Tissue Plasminogen Activator Use Persist at Primary Stroke Centers.

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    BACKGROUND: Primary stroke centers (PSCs) utilize more recombinant tissue plasminogen activator (rt-PA) than non-PSCs. The impact of PSCs on racial disparities in rt-PA use is unknown. METHODS AND RESULTS: We used data from the Nationwide Inpatient Sample from 2004 to 2010, limited to states that publicly reported hospital identity and race. Hospitals certified as PSCs by The Joint Commission were identified. Adults with a diagnosis of ischemic stroke were analyzed. Rt-PA use was defined by the International Classification of Diseases, 9th Revision procedure code 99.10. Discharges (304 152 patients) from 26 states met eligibility criteria, and of these 71.5% were white, 15.0% black, 7.9% Hispanic, and 5.6% other. Overall, 24.7% of white, 27.4% of black, 16.2% of Hispanic, and 29.8% of other patients presented to PSCs. A higher proportion received rt-PA at PSCs than non-PSCs in all race/ethnic groups (white 7.6% versus 2.6%, black 4.8% versus 2.0%, Hispanic 7.1% versus 2.4%, other 7.2% versus 2.5%, all P CONCLUSIONS: Racial disparities in intravenous rt-PA use were not reduced by presentation to PSCs. Black patients were less likely to receive thrombolytic treatment than white patients at both non-PSCs and PSCs. Hispanic patients were less likely to be seen at PSCs relative to white patients and were less likely to receive intravenous rt-PA in the fully adjusted model

    Illicit drug use and cerebral microbleeds in stroke and transient ischemic attack patients

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    Background: Cerebral microbleeds (CMB) signal cerebral small vessel disease and are associated with ischemic stroke (IS) incidence, recurrence, and complications. While illicit drug use (IDU) is associated with cerebral small vessel disease, the association between CMB and IDU is understudied. We sought to delineate differences in vascular risk factors between IDU and CMB and determine the effect of this relationship on outcomes in IS/transient ischemic attack (TIA) patients. Methods: We included 2001 consecutive IS and TIA patients (years 2009-2018) with a readable T2*gradient-echo MRI sequence. CMB rating followed standardized guidelines and CMB were grouped topographically into lobar, deep or infratentorial. IDU data (history and/or urine toxicology) was available for 1746 patients. The adverse composite outcome included pneumonia, urinary tract infection, deep venous thrombosis or death during hospitalization. Good functional outcome was defined as modified Rankin scale score < 3 and ambulatory on discharge. Univariate analysis was used to assess vascular risk factors and multivariable logistic regression was used to characterize the IDU/CMB relationship on outcomes. Results: We observed IDU in 13.8 % (n=241), and CMB in 32.9% (n=575, 53.8% lobar, 27.3% deep and 18.8% infratentorial). Patients with IDU and at least one CMB were older (53.6±10.5 vs. 56.9±11.5, p=0.04), had a lower BMI (28.1±5.9 vs. 26.6±4.4, p=0.04), and were more likely to have had a previous IS/TIA (25.1% vs. 41.9%, p=0.01). IDU trended higher for those with severe CMB (10+) compared with those without CMB and 1-9 CMB (25% [n=9] vs 14.3% [n=1171] and 12.1% [n=65] respectively; p=0.07) without individual drug deviations from this pattern. Adverse and good functional outcomes were observed in 177 and 905 total patients, respectively. No significant interaction was observed between IDU and CMB with either adverse or functional composite outcomes. Conclusion: IDU prevalence was high in our urban study population, and showed a borderline association with increasing CMB burden. Patients with CMB and IDU history were older and more likely to have had a previous IS/TIA. Further studies are required to clarify the clinical consequences related to the relationship between IDU and CMB.Author Disclosures: B. Petrie: None. H. Lau: None. F. Cajiga-Pena: None. S. Abbas: None. B. Finn: None. K. Dam: None. A. Cervantes-Arslanian: None. T.N. Nguyen: None. H. Aparicio: None. D. Greer: None. J.R. Romero: Speakers' Bureau; Modest; Received speaker honoraria from Ferrer Group

    Uso indebido del keterolac en la práctica médica habitual

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    El uso de antinflamatorios no esteroideos (AINEs) es muy frecuente en la práctica médica habitual. Los AINEs juegan un papel importante en el tratamiento del dolor en diversas condiciones clínicas. Se ha calculado que un argentino consume aproximadamente cinco cajas de Aines al año, sin supervisión médica. Uno de los AINEs más consumidos y prescriptos en nuestro país es el keterolac. El mismo, ha sido restringido en Europa a uso estrictamente hospitalario, por el riesgo de efectos adversos graves como hemorragias digestivas e insuficiencia renal, entre otros. Se plantea entonces la siguiente pregunta de investigación: ¿En la población en general con dolor agudo, El uso de keterolac, comparado con otros aines, es más efectivo y seguro? Objetivo: analizar la eficacia y seguridad del keterolac en la práctica clínica habitual.Facultad de Ciencias Médica

    CD200R1 contributes to successful functional reinnervation after a sciatic nerve injury

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    Activating and inhibitory immune receptors play a critical role in regulating systemic and central nervous system (CNS) immune and inflammatory processes. The CD200R1 immunoreceptor induces a restraining signal modulating inflammation and phagocytosis in the CNS under different inflammatory conditions. However, it remains unknown whether CD200R1 has a role in modulating the inflammatory response after a peripheral nerve injury, an essential component of the successful regeneration. Expression of CD200R1 and its ligand CD200 was analyzed during homeostasis and after a sciatic nerve crush injury in C57Bl/6 mice. The role of CD200R1 inWallerian Degeneration (WD) and nerve regeneration was studied using a specific antibody against CD200R1 injected into the nerve at the time of injury. We found an upregulation of CD200R1 mRNA after injury whereas CD200 was downregulated acutely after nerve injury. Blockade of CD200R1 significantly reduced the acute entrance of both neutrophils and monocytes from blood after nerve injury. When long term regeneration and functional recovery were evaluated, we found that blockade of CD200R1 had a significant effect impairing the spontaneous functional recovery. Taken together, these results show that CD200R1 has a role in mounting a successful acute inflammatory reaction after injury, and contributes to an effective functional recovery

    Sewershed surveillance as a tool for smart management of a pandemic in threshold countries. Case study: Tracking SARS-CoV-2 during COVID-19 pandemic in a major urban metropolis in northwestern Argentina

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    Wastewater-based epidemiology is an economical and effective tool for monitoring the COVID-19 pandemic. In this study we proposed sampling campaigns that addressed spatial-temporal trends within a metropolitan area. This is a local study of detection and quantification of SARS-CoV-2 in wastewater during the onset, rise, and decline of COVID-19 cases in Salta city (Argentina) over the course of a twenty-one-week period (13 Aug to 30 Dec) in 2020. Wastewater samples were gathered from 13 sewer manholes specific to each sewershed catchment, prior to convergence or mixing with other sewer lines, resulting in samples specific to individual catchments with defined areas. The 13 sewershed catchments selected comprise 118,832 connections to the network throughout the city, representing 84.7 % (534,747 individuals) of the total population. The number of COVID19-related exposure and symptoms cases in each area were registered using an application developed for smartphones by the provincial government. Geographical coordinates provided by the devices were recorded, and consequently, it was possible to geolocalise all app-cases and track them down to which of the 13 sampling catchments belonged. RNA fragments of SARS-CoV-2 were detected in every site since the beginning of the monitoring, anticipating viral circulation in the population. Over the course of the 21-week study, the concentrations of SARS-CoV-2 ranged between 1.77 × 104 and 4.35 × 107 genome copies/L. There was a correspondence with the highest viral load in wastewater and the peak number of cases reported by the app for each catchment. The associations were evaluated with correlation analysis. The viral loads of SARS-CoV-2 in wastewater were a feasible means to describe the trends of COVID-19 infections. Surveillance at sewershed scale, provided reliable and strategic information that could be used by local health stakeholders to manage the COVID-19 pandemic.Fil: Cruz, Mercedes Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Sanguino Jorquera, Diego Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Aparicio González, Mónica Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Irazusta, Verónica Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Naturales; ArgentinaFil: Poma, Hugo Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Cristobal, Hector Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Naturales; ArgentinaFil: Rajal, Verónica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Nanyang Technological University; Singapu

    Neutral Hydrogen and Star Formation in the Irregular Galaxy NGC 2366

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    We present UBVJHKHalpha and HI data of the irregular galaxy NGC 2366. It is a normal boxy-shaped disk seen at high inclination angle. We do not see any unambiguous observational signature of a bar. There is an asymmetrical extension of stars along one end of the major axis of the galaxy, and this is where the furthest star-forming regions are found, at 1.3R_Holmberg. The HI is normal in many respects but shows some anomalies: 1) The integrated HI shows two ridges running parallel to the major axis that deproject to a large ring. 2) The velocity field exhibits several large-scale anomalies superposed on a rotating disk. 3) The inclination and position angles derived from the kinematics differ from those dervied from the optical and HI mor- phology. 4) There are regions in the HI of unusually high velocity dispersion that correlate with deficits of HI emission in a manner suggestive of long-range, turbulent pressure equilibrium. Star-forming regions are found where the gas densities locally exceed 6 Msolar/pc^2. NGC 2366, like other irregulars, has low gas densities relative to the critical gas densities of gravitational instability models. Because of the lack of shear in the optical galaxy, there is little competition to the slow gravitational contraction that follows energy dissipation. However, the peak gas densities in the star-forming regions are equal to the local tidal densities for gravitational self-binding of a rotating cloud. Evidently the large scale gas concentrations are marginally bound against background galactic tidal forces. This condition for self-binding may be more fundamental than the instability condition because it is local, three-dimensional, and does not involve spiral arm generation as an intermediate step toward star formation.Comment: To be published in ApJ; better figures available ftp.lowell.edu, cd pub/dah/n2366pape

    Knowledge-defined networking

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    The research community has considered in the past the application of Artificial Intelligence (AI) techniques to control and operate networks. A notable example is the Knowledge Plane proposed by D.Clark et al. However, such techniques have not been extensively prototyped or deployed in the field yet. In this paper, we explore the reasons for the lack of adoption and posit that the rise of two recent paradigms: Software-Defined Networking (SDN) and Network Analytics (NA), will facilitate the adoption of AI techniques in the context of network operation and control. We describe a new paradigm that accommodates and exploits SDN, NA and AI, and provide use-cases that illustrate its applicability and benefits. We also present simple experimental results that support, for some relevant use-cases, its feasibility. We refer to this new paradigm as Knowledge-Defined Networking (KDN).Peer ReviewedPostprint (author's final draft
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