168 research outputs found

    Quick-Tune: Quickly Learning Which Pretrained Model to Finetune and How

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    With the ever-increasing number of pretrained models, machine learning practitioners are continuously faced with which pretrained model to use, and how to finetune it for a new dataset. In this paper, we propose a methodology that jointly searches for the optimal pretrained model and the hyperparameters for finetuning it. Our method transfers knowledge about the performance of many pretrained models with multiple hyperparameter configurations on a series of datasets. To this aim, we evaluated over 20k hyperparameter configurations for finetuning 24 pretrained image classification models on 87 datasets to generate a large-scale meta-dataset. We meta-learn a multi-fidelity performance predictor on the learning curves of this meta-dataset and use it for fast hyperparameter optimization on new datasets. We empirically demonstrate that our resulting approach can quickly select an accurate pretrained model for a new dataset together with its optimal hyperparameters

    Calidad del seguimiento a la exposición perinatal al HIV y observancia de las estrategias reconocidas para disminuir su transmisión en un centro de referencia de Medellín

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    Introduction: Prevention of mother-to-child transmission of the human immunodeficiency virus (HIV) is essential to limit the spread of the disease. Colombian data about HIV infection in pregnancy are scarce, as well as on the results of the strategies used worldwide to reduce perinatal transmission.Objective: To describe the characteristics and outcomes of pregnant women infected with HIV and their children in a reference center in Medellín.Materials and methods: We conducted a retrospective observational study for the 2012-2015 period by studying the clinical records of newborns exposed to HIV and their mothers. We evaluated the characteristics of prenatal care, deliveries, and infant postnatal care, as well as the follow-up data to confirm or exclude HIV transmission.Results: We included 106 infants and their mothers. We found that 39,6% of mothers knew about the HIV diagnosis before pregnancy and 58,5% were diagnosed during pregnancy; 95.3% of them attended prenatal controls, but only 46.5% as of the first trimester; 95% of them received antiretrovirals, but 23.9% started therapy just during the third trimester. Only 63% of women had a viral load for HIV after 34 weeks of gestation. None of the 103 children with follow up had confirmed presence for HIV and in 88% of them, it was discarded.Conclusions: No cases of perinatal HIV transmission were found in the study. However, difficulties and delays persist in prenatal care, in timely maternal follow-up to confirm or discard HIV, and for early detection of maternal co-infections and their effects on newborns.Introducción. La prevención de la transmisión materno-infantil del virus de la inmunodeficiencia humana (Human Immunodeficiency Virus, HIV) es una estrategia fundamental para evitar la infección en niños. A nivel local, se desconoce la situación de las mujeres gestantes infectadas por HIV y el grado de observancia de las estrategias reconocidas mundialmente para disminuir la transmisión perinatal.Objetivo. Describir las características sociodemográficas y clínicas de las mujeres gestantes con HIV y de sus hijos en un centro de referencia de Medellín.Materiales y métodos. Se hizo un estudio descriptivo retrospectivo entre 2012 y 2015 mediante la revisión de las historias clínicas de las mujeres gestantes con HIV y de sus neonatos habidos en partos atendidos en el Hospital San Vicente Fundación. Se describieron las variables de atención prenatal, parto, recién nacido y seguimiento de los neonatos.Resultados. Se analizaron 106 madres y sus hijos expuestos al HIV. El 39,6 % de las mujeres gestantes conocía el diagnóstico antes del embarazo y al 58,5 % se le diagnosticó durante este. El 95,3 % de las mujeres gestantes asistió a control prenatal, 46,5 % de ellas a partir del primer trimestre. Si bien el 95 % recibió antirretrovirales, el 23,9 % comenzó a tomarlos tardíamente en el tercer trimestre. Solo el 63 % de las mujeres registró carga viral para el HIV después de la semana 34 de gestación. El 90,6 % de los partos fueron por cesárea, y el virus del papiloma humano y la sífilis fueron las principales infecciones concomitantes. Se hizo seguimiento de 103 niños (no fue posible localizar a tres de ellos para el seguimiento), a ninguno se le confirmó la presencia del HIV y, en el 88 %, se descartó.Conclusiones. En este estudio, no se registraron casos de transmisión perinatal. Sin embargo, siguen presentándose fallas y retrasos en la atención prenatal y en la oportunidad del seguimiento materno para confirmar oportunamente el HIV y para detectar tempranamente infecciones maternas concomitantes que eviten la morbilidad y las secuelas en los neonatos

    Temas Socio-Jurídicos. Volumen 14 No. 30 Agosto de 1996

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    La Revista Temas Socio-Jurídicos en su edición número 30, desea anunciar a sus lectores, poniéndola a disposición de la comunidad científica nacional la adquisición de la obra completa de Galileo Galilei en su primera edición florentina de 1842.The Socio-Legal Issues Magazine, in its 30th edition, wishes to announce to its readers, making it available to the national scientific community the acquisition of the complete works of Galileo Galilei in its first Florentine edition of 1842

    T Helper 1–Inducing Adjuvant Protects against Experimental Paracoccidioidomycosis

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    Immunostimulatory therapy is a promising approach to improving the treatment of systemic fungal infections such as paracoccidioidomycosis (PCM), whose drug therapy is usually prolonged and associated with toxic side effects and relapses. The current study was undertaken to determine if the injection of a T helper (Th) 1–stimulating adjuvant in P. brasiliensis–infected mice could have a beneficial effect on the course of experimental PCM. For this purpose, mice were infected and treated with complete Freund's adjuvant (CFA), a well-established Th1 experimental inductor, or incomplete Freund's adjuvant (IFA - control group) on day 20 postinfection. Four weeks after treatment, the CFA-treated mice presented a mild infection in the lungs characterized by absence of epithelioid cell granulomas and yeast cells, whereas the control mice presented multiple sites of focal epithelioid granulomas with lymphomonocytic halos circumscribing a high number of viable and nonviable yeast cells. In addition, CFA administration induced a 2.4 log reduction (>99%) in the fungal burden when compared to the control group, and led to an improvement of immune response, reversing the immunosuppression observed in the control group. The immunotherapy with Th1-inducing adjuvant, approved to be used in humans, might be a valuable tool in the treatment of PCM and potentially useful to improve the clinical cure rate in humans

    Global Patterns and Controls of Nutrient Immobilization On Decomposing Cellulose In Riverine Ecosystems

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    Microbes play a critical role in plant litter decomposition and influence the fate of carbon in rivers and riparian zones. When decomposing low-nutrient plant litter, microbes acquire nitrogen (N) and phosphorus (P) from the environment (i.e., nutrient immobilization), and this process is potentially sensitive to nutrient loading and changing climate. Nonetheless, environmental controls on immobilization are poorly understood because rates are also influenced by plant litter chemistry, which is coupled to the same environmental factors. Here we used a standardized, low-nutrient organic matter substrate (cotton strips) to quantify nutrient immobilization at 100 paired stream and riparian sites representing 11 biomes worldwide. Immobilization rates varied by three orders of magnitude, were greater in rivers than riparian zones, and were strongly correlated to decomposition rates. In rivers, P immobilization rates were controlled by surface water phosphate concentrations, but N immobilization rates were not related to inorganic N. The N:P of immobilized nutrients was tightly constrained to a molar ratio of 10:1 despite wide variation in surface water N:P. Immobilization rates were temperature-dependent in riparian zones but not related to temperature in rivers. However, in rivers nutrient supply ultimately controlled whether microbes could achieve the maximum expected decomposition rate at a given temperature

    Global patterns and drivers of ecosystem functioning in rivers and riparian zones

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    River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.peerReviewe

    Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

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    BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
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