68 research outputs found

    Monitoring of the Fall Armyworm (Spodoptera frugiperda Walker) Moth for the Determination of Efficient Chemical Control in Zea mays L.

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    Objective: To determine the population dynamics of the fall armyworm (FAW), identify the critical period of highest infestation and to determine the number of agrochemicals applications for its control. Design/methodology/approach: A monitoring and capture of male FAW moths was conducted using plastic traps with sexual attraction pheromones. A daily count of captured moths was performed during the crop season, the data were plotted to determine the period of highest infestation and the optimal timing for chemical control. Additionally, the number of insecticide applications for FAW control was evaluated, with treatments including none (T0), one (T1), two (T2), three (T3), and four (T4) applications. A randomized complete block design with nine repetitions was used. Before each application, the number of plants with visible damage and its intensity were counted using the Davis visual scale. Statistical analysis of the measured variables was conducted. Results: The results showed that moths were evenly distributed across the planted surface, and two periods of higher infestation were identified: between 32 to 35 and 70 to 76 days after planting, respectively. The biological cycle of the FAW was between 38 to 41 days. The analysis of variance showed statistical differences (p ≤ 0.001) among the treatments. Findings/conclusions: Using plastic traps with sexual attraction pheromones is an efficient method for capturing, monitoring, reducing the population, estimate the length of the biological cycle, and identifying the highest infestation period of the FAW. Moreover, two insecticide applications during the periods of highest infestation resulted in optimal control of FAW

    Efecto de la capacidad visoespacial en el rendimiento académico de estudiantes de anatomía médica

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    Visuospatial ability is associated with clinical skills in medical education, as it predicts the academic performance of anatomy students. Objective: To determine whether visuospatial processing generates changes in the teaching of medical anatomy and predicts academic performance in that subject. Methods: 140 students were evaluated at the beginning of the semester and before final exams with the Rey Complex Figure Test (CRFT).  Student's t-tests were performed to contrast pre- and post-test differences, Cohen's d to measure effect size, and linear regression to evaluate prediction with final grades. Results: Mean age 20.22 years (SD=1.12), mean grade point average 4.96 (SD=1.20). Seventy percent of the students passed the course. The t-test reports significant differences of TFCR (Memory recall: t=-17.383; p<0.001; Delayed recall: t=-16.547, p<0.001) with a medium effect size (d=0.59 and d=0.56), respectively. The scores obtained in the post-test on the TFCR deferred recall task explained up to 90% of the students' academic performance. Conclusions: The instrument's deferred memory predicted academic performance and anatomy learning improved students' visuospatial function performance.La capacidad visoespacial se asocia con habilidades clínicas en la educación médica, ya que predice el desempeño académico de los estudiantes de anatomía. Objetivo: Determinar si el procesamiento visoespacial genera cambios en la enseñanza de la anatomía médica y predice el desempeño académico en esa asignatura. Método: 140 estudiantes evaluados al inicio de semestre y antes de exámenes finales con el Test de la Figura Compleja de Rey.  Se realizaron análisis t de Student para contrastar las diferencias pre y pos-test, d de Cohen para medir el tamaño de efecto y regresión lineal para evaluar la predicción con las notas finales. Resultados: Edad promedio 20.22 años (DE=1.12), media de calificaciones 4.96 (DE=1.20). El 70% de los estudiantes aprobó la asignatura. La prueba t reporta diferencias significativas del TFCR (Evocación de Memoria: t=-17.383; p<0.001; Evocación diferida: t=-16.547, p<0.001) con un tamaño del efecto mediano (d=0.59 y d=0.56), respectivamente. Las puntuaciones obtenidas en el post-test en la tarea de memoria diferida del TFCR, explicaron hasta en un 90% el desempeño académico de los estudiantes. Conclusiones: La memoria diferida del instrumento predijo el rendimiento académico y el aprendizaje de anatomía mejoró el desempeño en la función visoespacial de los estudiantes

    Molecular characterization of occult hepatitis B virus infection in patients with end-stage liver disease in Colombia.

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    ABSTARCT: Hepatitis B virus (HBV) occult infection (OBI) is a risk factor to be taken into account in transfusion, hemodialysis and organ transplantation. The aim of this study was to identify and characterize at the molecular level OBI cases in patients with end-stage liver disease. METHODS: Sixty-six liver samples were obtained from patients with diagnosis of end-stage liver disease submitted to liver transplantation in Medellin (North West, Colombia). Samples obtained from patients who were negative for the surface antigen of HBV (n = 50) were tested for viral DNA detection by nested PCR for ORFs S, C, and X and confirmed by Southern-Blot. OBI cases were analyzed by sequencing the viral genome to determine the genotype and mutations; additionally, viral genome integration events were examined by the Alu-PCR technique. RESULTS: In five cases out of 50 patients (10%) the criteria for OBI was confirmed. HBV genotype F (subgenotypes F1 and F3), genotype A and genotype D were characterized in liver samples. Three integration events in chromosomes 5q14.1, 16p13 and 20q12 affecting Receptor-type tyrosine-protein phosphatase T, Ras Protein Specific Guanine Nucleotide Releasing Factor 2, and the zinc finger 263 genes were identified in two OBI cases. Sequence analysis of the viral genome of the 5 OBI cases showed several punctual missense and nonsense mutations affecting ORFs S, P, Core and X. CONCLUSIONS: This is the first characterization of OBI in patients with end-stage liver disease in Colombia. The OBI cases were identified in patients with HCV infection or cryptogenic cirrhosis. The integration events (5q14.1, 16p13 and 20q12) described in this study have not been previously reported. Further studies are required to validate the role of mutations and integration events in OBI pathogenesis

    Estimating the global conservation status of more than 15,000 Amazonian tree species

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    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

    Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

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    Caracterização da matéria orgânica fornecida por liteira fina em matas ciliares do rio Gaira (Sierra Nevada de Santa Marta - Colômbia)

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    The objective of this research was to characterize the production of fine litter provided by five abundant species on a stretch of the middle basin of the Gaira river. The study was carried out for six months, with bimonthly collections in 87 fall traps distributed systematically every 10 m for a total of 10 transects. The collected material was separated by fractions and it was determined and their contribution in terms of dry mass, resulting in a yearly production of 3764 kg ha- 1, that the extrapolated a year represented 7529 kg ha-1, intermediate value than those in other studies in tropical rainforests. The production of fine litter was dominated by the leaf fraction (65% ), followed by the woody material (17.7% ), reproductive material (9.4 %) and other debris (7.6% ). The highest production of leaf litter was recorded for Nectandra cf. turbacensis (152.27 kg ha-1) and the lower production was for the Pouteria arguacoensium (9.66 kg ha-1). The Nectandra cf. turbacensis and the Zygia longifolia species presented the major leaf litter contributions, which were categorized as potential species for inclusion in activities for the restoration of coastal areas by water currents.El objetivo de esta investigación fue caracterizar la producción de hojarasca fina aportada por cinco especies abundantes en un tramo de la cuenca media del rio Gaira. El estudio se realizó durante seis meses, con recolecciones bimensuales en 87 trampas de caída distribuidas sistemáticamente cada 10 m en un total de 10 transectos. El material colectado se separó por fracciones y se determinó su aporte en términos de masa seca, dando como resultado una producción semestral de 3764 kg ha-1, que extrapolada a un ano represento 7529 kg ha-1, valor intermedio a los registrados en otros estudios realizados en bosques húmedos tropicales. La producción de hojarasca fina estuvo dominada por la fracción foliar (65%), seguida del material lenoso (17,7%), material reproductivo (9,4%) y otros restos (7,6%). La mayor producción de hojarasca foliar se registró para Nectandra cf. turbacensis (152,27 kgha-1)y la menor producción la obtuvo Pouteria arguacoensium (9,66 kgha-1). Las especies Nectandra cf. turbacensis y Zygia longifolia presentaron los mayores aportes de hojarasca foliar, tipificándolas como especies potenciales para su inclusión en actividades de restauración de zonas riberenas de corrientes de agua.O objetivo deste estudo foi caracterizar a producao de serapilheira fina de cinco especies abundantes fornecidas num tramo da bacia media do rio Gaira. O estudo foi realizado ao longo de seis meses, com coletas bimestrais em 87 armadilhas de queda a cada 10 m distribuidas sistematicamente em um total de 10 transeptos. O material coletado foi separado por fracoes e sua contribuicao foi determinada em termos de massa seca, resultando em uma producao semestral de 3764 kg ha-1, extrapolados para um ano foi responsavel por 7529 kg ha-1, valor dentro da media dos registrados em outros estudos em florestas tropicais. Producao da serapilheira fina foi dominada pela fracao foliar (65%), seguido por material lenhoso (17,7%), material reprodutivo (9,4%) e outros residuos (7,6%). A maior producao de serapilheira foliar foi para Nectandra cf. turbacensis (152,27 kgha-1) e a menor obtida em Pouteriaarguacoensium (9,66 kg ha-1). As especies Nectandra cf. Turbacensis e Zygialongifolia tiveram a maior contribuicao da serapilheira, tipificando-as como especies potenciais para inclusao em atividades de restauracao em locais ribeirinhos de corregos de agu

    A Simplified Method for Left Heart Catheterization including Coronary Arteriography

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    A simplified method for performing retrograde left heart catheterization is described which utilizes a family of preshaped catheters via brachial artery cut-down. A single closed-tip catheter was the sole catheter utilized to accomplish complete left heart studies including coronarv artery cineangiography, ventriculography and aortography in 50 or our last 100 cases. A second, specially shaped, open-tip catheter was used in an additional 46 cases, and a third in four. The aortic valve could be crossed readily, and ventriculography was accomplished with a minimum of premature ventricular contractions. Coronary arteriography could be performed safely with a closed-tip catheter in the majority of our patients. Left heart study with these catheters caused minimal arterial trauma, a low incidence of complications, and shortened catheterization times

    Sleep Quality, Insomnia, and Perceived Stress among Colombian Healthcare Workers during the COVID-19 Pandemic

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    +Q4Q3Trabajadores de la salud del Hospital Universitario San IgnacioObjective: The COVID-19 pandemic has imposed a great burden on healthcare workers worldwide. The aim of the present study was to assess sleep quality, insomnia, and perceived stress in healthcare workers of a high complexity hospital located in Bogota, Colombia. Methods: Cross-sectional study in which 1,155 healthcare workers at the Hospital Universitario San Ignacio in Bogotá, Colombia were included, between September and October 2020. Using an online-based survey, self-reported variables were assessed including demographics, Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and 10 item Perceived Stress Scale (PSS-10). Associations between these variables were evaluated. Results: Fifty percent of the respondents were between 31 and 45 years old, and 76 percent were women. Most of the surveyed were the nursing staff. Poor sleep quality, insomnia, and high perceived stress was found in 74.9, 12.4, and 13.2%, respectively. Poor sleep quality was predominantly found in females, in the 31 to 45 years old group and in married personnel. Also, poor sleep quality was found in relation to a moderate to high perceived risk of COVID-19 infection by the family of the workers surveyed. Discussion: Poor sleep quality, moderate rates of insomnia, and perceived stress were found among healthcare workers committed to COVID-19 infected patients in Colombia. The identification of workers at greater risk and the implementation of targeted interventions are called upon as the results.https://orcid.org/0000-0001-5426-4579https://orcid.org/0000-0002-8244-2958https://orcid.org/0000-0001-8859-1711https://orcid.org/0000-0002-3885-5448https://orcid.org/0000-0001-6528-4268https://orcid.org/0000-0002-2536-4471https://orcid.org/0000-0001-5576-9341Revista Internacional - IndexadaA2N
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