170 research outputs found

    Machine-Learning Enhanced Photometric Analysis of the Extremely Bright GRB 210822A

    Full text link
    We present analytical and numerical models of the bright long GRB 210822A at z=1.736z=1.736. The intrinsic extreme brightness exhibited in the optical, which is very similar to other bright GRBs (e.g., GRBs 080319B, 130427A, 160625A 190114C, and 221009A), makes GRB 210822A an ideal case for studying the evolution of this particular kind of GRB. We use optical data from the RATIR instrument starting at T+315.9T+315.9 s, with publicly available optical data from other ground-based observatories, as well as X-ray data from the Swift/X-ray Telescope (XRT) and data from the Swift/Ultraviolet/Optical Telescope (UVOT). The temporal profiles and spectral properties during the late stages align consistently with the conventional forward shock model, complemented by a reverse shock element that dominates optical emissions during the initial phases (T<300T<300 s). Furthermore, we observe a break at T=80000T=80000 s that we interpreted as evidence of a jet break, which constrains the opening angle to be about θj=(35)\theta_\mathrm{j}=(3-5) degrees. Finally, we apply a machine-learning technique to model the multi-wavelength light curve of GRB 210822A using the AFTERGLOWPY library. We estimate the angle of sight θobs=(6.4±0.1)×101\theta_{obs}=(6.4 \pm 0.1) \times 10^{-1} degrees, the energy E0=(7.9±1.6)×1053E_0= (7.9 \pm 1.6)\times 10^{53} ergs, the electron index p=2.54±0.10p=2.54 \pm 0.10, the thermal energy fraction in electrons ϵe=(4.63±0.91)×105\epsilon_e=(4.63 \pm 0.91) \times 10^{-5} and in the magnetic field ϵB=(8.66±1.01)×106\epsilon_B= (8.66 \pm 1.01) \times 10^{-6}, the efficiency χ=0.89±0.01\chi = 0.89 \pm 0.01, and the density of the surrounding medium n0=0.85±0.01n_\mathrm{0} = 0.85 \pm 0.01.Comment: Submitted to MNRAS, 11 pages, 6 figures. Fixed typo

    Efeito da época de preparo do camalhão no desenvolvimento de plantas de soja em terras baixas/ Effect of the time of preparing the camalhão on the development of soybean plants

    Get PDF
    Objetivou-se com o presente estudo avaliar o estabelecimento e o desempenho de crescimento de plantas de soja, quando cultivadas em sistema de sulco-camalhão, preparado antecipadamente ou na hora da semeadura, em terras baixas de clima temperado. O experimento foi conduzido a campo, na área experimental da Embrapa Clima Temperado, Estação Experimental Terras Baixas, no município do Capão do Leão-RS, em delineamento experimental em blocos casualizados, com parcelas dispostas em faixas, com seis repetições. Os tratamentos constaram da época de preparo do camalhão. Os camalhões antecipados (tratamento 1 - TCA), foram construídos em abril de 2018, com camalhoeira, sendo imediatamente semeado a lanço o azevém cv. BRS Ponteio, na densidade de 15 kg ha?1 de sementes. Previamente a semeadura da soja, a área foi dessecada com 1440 ge.a. ha?1 de glyphosate, e a semeadura foi realizada com semeadeira Vence Tudo. Os camalhões confeccionados concomitantemente ao plantio (tratamento 2 - TCFH), foram feitos pela própria semeadeira, que possuía pé de pato específicos para tal operação. Foram avaliadas a área foliar, diâmetro do caule, altura de planta e conteúdo de água das plantas de soja em função dos dias após emergência (DAE). As avaliações foram efetuadas quinzenalmente da emergência à maturação dos grãos. A soja semeada no camalhão feito concomitante à semeadura apresentou melhor desenvolvimento vegetativo, comparativamente ao plantio sobre sulco-camalhão antecipado, principalmente aumentando a área foliar e diâmetro de caule. Supõe-se que condições diferenciais de adensamento e fertilidade do solo e consequente desenvolvimento radicular possam ter contribuído para esse resultado, mas isso deve ser investigado em maiores detalhes futuramente para confirmar ou refutar esses resultados

    Persistent symptoms and decreased health-related quality of life after symptomatic pediatric COVID-19: A prospective study in a Latin American tertiary hospital

    Get PDF
    OBJECTIVES: To prospectively evaluate demographic, anthropometric and health-related quality of life (HRQoL) in pediatric patients with laboratory-confirmed coronavirus disease 2019 (COVID-19) METHODS: This was a longitudinal observational study of surviving pediatric post-COVID-19 patients (n=53) and pediatric subjects without laboratory-confirmed COVID-19 included as controls (n=52) was performed. RESULTS: The median duration between COVID-19 diagnosis (n=53) and follow-up was 4.4 months (0.8-10.7). Twenty-three of 53 (43%) patients reported at least one persistent symptom at the longitudinal follow-up visit and 12/53 (23%) had long COVID-19, with at least one symptom lasting for &gt;12 weeks. The most frequently reported symptoms at the longitudinal follow-up visit were headache (19%), severe recurrent headache (9%), tiredness (9%), dyspnea (8%), and concentration difficulty (4%). At the longitudinal follow-up visit, the frequencies of anemia (11%&nbsp;versus&nbsp;0%,&nbsp;p=0.030), lymphopenia (42%&nbsp;versus&nbsp;18%,&nbsp;p=0.020), C-reactive protein level of &gt;30 mg/L (35%&nbsp;versus&nbsp;0%,&nbsp;p=0.0001), and D-dimer level of &gt;1000 ng/mL (43%&nbsp;versus&nbsp;6%,&nbsp;p=0.0004) significantly reduced compared with baseline values. Chest X-ray abnormalities (11%&nbsp;versus&nbsp;2%,&nbsp;p=0.178) and cardiac alterations on echocardiogram (33%&nbsp;versus&nbsp;22%,&nbsp;p=0.462) were similar at both visits. Comparison of characteristic data between patients with COVID-19 at the longitudinal follow-up visit and controls showed similar age (p=0.962), proportion of male sex (p=0.907), ethnicity (p=0.566), family minimum monthly wage (p=0.664), body mass index (p=0.601), and pediatric pre-existing chronic conditions (p=1.000). The Pediatric Quality of Live Inventory 4.0 scores, median physical score (69 [0-100]&nbsp;versus&nbsp;81 [34-100],&nbsp;p=0.012), and school score (60 [15-100]&nbsp;versus&nbsp;70 [15-95],&nbsp;p=0.028) were significantly lower in pediatric patients with COVID-19 at the longitudinal follow-up visit than in controls. CONCLUSIONS: Pediatric patients with COVID-19 showed a longitudinal impact on HRQoL parameters, particularly in physical/school domains, reinforcing the need for a prospective multidisciplinary approach for these patients. These data highlight the importance of closer monitoring of children and adolescents by the clinical team after COVID-19

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Virulence in Murine Model Shows the Existence of Two Distinct Populations of Brazilian Vaccinia virus Strains

    Get PDF
    Brazilian Vaccinia virus had been isolated from sentinel mice, rodents and recently from humans, cows and calves during outbreaks on dairy farms in several rural areas in Brazil, leading to high economic and social impact. Some phylogenetic studies have demonstrated the existence of two different populations of Brazilian Vaccinia virus strains circulating in nature, but little is known about their biological characteristics. Therefore, our goal was to study the virulence pattern of seven Brazilian Vaccinia virus strains. Infected BALB/c mice were monitored for morbidity, mortality and viral replication in organs as trachea, lungs, heart, kidneys, liver, brain and spleen. Based on the virulence potential, the Brazilian Vaccinia virus strains were grouped into two groups. One group contained GP1V, VBH, SAV and BAV which caused disease and death in infected mice and the second one included ARAV, GP2V and PSTV which did not cause any clinical signals or death in infected BALB/c mice. The subdivision of Brazilian Vaccinia virus strains into two groups is in agreement with previous genetic studies. Those data reinforce the existence of different populations circulating in Brazil regarding the genetic and virulence characteristics

    Genetic Evidence Supporting the Association of Protease and Protease Inhibitor Genes with Inflammatory Bowel Disease: A Systematic Review

    Get PDF
    As part of the European research consortium IBDase, we addressed the role of proteases and protease inhibitors (P/PIs) in inflammatory bowel disease (IBD), characterized by chronic mucosal inflammation of the gastrointestinal tract, which affects 2.2 million people in Europe and 1.4 million people in North America. We systematically reviewed all published genetic studies on populations of European ancestry (67 studies on Crohn's disease [CD] and 37 studies on ulcerative colitis [UC]) to identify critical genomic regions associated with IBD. We developed a computer algorithm to map the 807 P/PI genes with exact genomic locations listed in the MEROPS database of peptidases onto these critical regions and to rank P/PI genes according to the accumulated evidence for their association with CD and UC. 82 P/PI genes (75 coding for proteases and 7 coding for protease inhibitors) were retained for CD based on the accumulated evidence. The cylindromatosis/turban tumor syndrome gene (CYLD) on chromosome 16 ranked highest, followed by acylaminoacyl-peptidase (APEH), dystroglycan (DAG1), macrophage-stimulating protein (MST1) and ubiquitin-specific peptidase 4 (USP4), all located on chromosome 3. For UC, 18 P/PI genes were retained (14 proteases and 4protease inhibitors), with a considerably lower amount of accumulated evidence. The ranking of P/PI genes as established in this systematic review is currently used to guide validation studies of candidate P/PI genes, and their functional characterization in interdisciplinary mechanistic studies in vitro and in vivo as part of IBDase. The approach used here overcomes some of the problems encountered when subjectively selecting genes for further evaluation and could be applied to any complex disease and gene family

    Prospective cohort study of patients with COVID-19 hospitalized in the Internal Medicine ward of Hospital Durand: study protocol

    Get PDF
    Fil: Melendi, Santiago E. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Pérez, María M. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Salas, Cintia E. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Aguirre, Camila. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Baleta, María L. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Balsano, Facundo J. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Caldano, Mariano G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Colignon, María G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Oliveira Brasil, Thayana De. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Wolodimeroff, Nicolás de. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Déramo Aquino, Andrea I. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Fernández de Córdova, Ana G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Fontan, María B. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Galvagno, Florencia I. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Haedo, Mariana F. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Iturrieta Araya, Noelia S. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Mollinedo Cruz,Volga S. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Olivero, Agustín. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Pestalardo, Ignacio. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Ricciardi, María. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Saltos Navarrete, Jandry D. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Vera Rueda, María L. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Villaverde, María C. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Xavier, Franco B. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Lauko, Marcela. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Ujeda, Carlos. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Leis, Rocío. Hospital General de Agudos Carlos G. Durand; Argentina.INTRODUCCIÓN: Conocer los predictores de mala evolución en pacientes con Enfermedad por Coronavirus 2019 (COVID-19) permite identificar de forma temprana a los pacientes con peor pronóstico, aportando mejores herramientas a la hora de tomar decisiones clínicas. Se presenta el protocolo de un estudio de cohorte cuyo objetivo principal es identificar factores de riesgo de infección severa, critica y mortalidad en pacientes con COVID-19 internados en el Servicio de Clínica Médica del Hospital Durand (Buenos Aires, Argentina). MÉTODOS: Estudio de cohorte prospectivo con base en un único centro. Se incluirá a todos los pacientes que ingresen al servicio de Clínica Médica con diagnóstico de COVID-19 durante el periodo de estudio. Se recolectarán las características epidemiológicas, clínicas, de laboratorio, radiológicas y los datos de tratamiento, al ingreso y al momento del alta o muerte hospitalaria. El evento final primario es la muerte en la internación; los eventos secundarios son el desarrollo de enfermedad grave y enfermedad crítica, la internación en unidad cerrada y el requerimiento de asistencia respiratoria mecánica
    corecore