Prevalence of chagas disease in Colombia : a systematic review and meta-analysis

Q2Artículo de investigación1-18Background Despite the adoption of campaigns to interrupt the main vector and to detect Trypanosoma cruzi in blood banks, millions of people are still chronically infected; however, the prevalence data are limited, and the epidemiology of Chagas disease has not been systematically evaluated. This study aimed to estimate the prevalence of Chagas disease in Colombia. Methods A systematic literature review and meta-analysis was conducted to select all observational studies reporting the prevalence of Chagas disease in Colombia, based on serological diagnosis in participants of any age and published between January 2007 and November 2017. Pooled estimates and 95% confidence intervals (95% CIs) were calculated using randomeffects models. In addition, the I 2 statistic was calculated. Results The literature search yielded a total of 1,510 studies; sixteen articles with relevant prevalence data were included in the systematic review. Of these, only 12 articles were included for entry in the meta-analysis. The pooled prevalence of Chagas disease across studies was 2.0% (95% CI: 1.0–4.0). A high degree of heterogeneity was found among studies (I2 > 75%; p < 0.001). The publication bias was not statistically significant (Egger’s test, p = 0.078). The highest pooled prevalences were found in the adult population (3.0%, 95% CI: 1.0–4.0), pregnant women (3.0%, 95% CI: 3.0–4.0) and the Orinoco region (7.0%, 95% CI: 2.2–12.6). Conclusions The results indicate that the T. cruzi-infected population is aging, the adult population, pregnant women and that the Orinoco region (department of Casanare) have the highest prevalences. These results highlight the need to maintain screening and surveillance programs to identify people with chronic T. cruzi infections

Designing a minimal reactive goalie for the RoboCup SPL

This paper presents the basic design and implementation of a goalkeeper made according to the regulations of the two-legged Standard Platform League of the RoboCup Federation. The paper describes the perceptive schemas created using the architecture of the TeamChaos-URJC team as well as the action schemes designed to create a minimal reactive goalie. This player was tested in the 2009 German Open international competition. The results obtained there are analyzed and the future works derived from that analysis are presente

Efectos del entrenamiento de fuerza integrado dos veces por semana en jóvenes

La aptitud física es uno de los factores más importante para prevenir las enfermedades cardiovasculares La fuerza es uno de los componentes más influyentes sobre la aptitud física. Objetivo: Se estudió un grupo de 21 varones (V) y 11 mujeres (M) jóvenes, al cual se aplicó un programa de entrenamiento de fuerza integrado durante 7 semanas, con una frecuencia de 2 días semanales. Método: Se evaluó la fuerza máxima a través de una repetición máxima (1RM) en los ejercicios de press de banca (PB) y ¿ sentadilla (SEN). El entrenamiento consistió en aplicar intensidades del 45 al 90% y volúmenes de 10 a 18 repeticiones por ejercicio, saltos y pliometría. Resultados: Se encontraron diferencias significativas p< 0.01 pre y post entrenamiento, PB en V 57.9 + 7.2 vs 65 + 8.2 Kg; SEN en V 84.1 + 15.3 vs 101.1 + 16.1 Kg; PB en M 38.5 + 8.6 vs 47.4 + 6.7 Kg SEN en M 61.8 + 15.1 vs 80.3 + 13.7 Kg. Conclusión: El entrenamiento de dos veces a la semana con un programa de fuerza integrado, durante 7 semanas incrementa la fuerza en forma significativa en jóvenes sanos de ambos

EFECTO DE LA APLICACIÓN CONJUNTA DE RADIACIONES Y ACEITES ESENCIALES SOBRE LA SUPERFICIE DE CARNES BOVINAS REFRIGERADAS

La carne bovina es un alimento que puede contaminarse fácilmente con microorganismos favoreciendo el desarrollo de agentes patógenos. El almacenamiento a bajas temperaturas es uno de los métodos más comunes de preservación de este alimento, pero al combinarlo con otros tratamientos (luz UVC, aceites esenciales, envasado) aumenta su eficiencia significativamente, reduciendo el crecimiento microbiano casi por completo. El objetivo principal de este trabajo fue estudiar el efecto de la aplicación conjunta de dichos tratamientos sobre la superficie de carnes bovinas, con énfasis en su efecto sobre la calidad microbiana y la aceptabilidad sensorial. Se realizaron estudios microbiológicos (EM), determinación de la evolución del color superficial (CS), predicción de vida útil (VU) y ensayos de evaluación sensorial. Para los EM se obtuvieron muestras a partir de bife y nalga, separadas en dos grupos: control (C, sin tratar) y tratadas (Tir, irradiadas con luz UVC y rociadas con solución de aceite esencial de romero y ácido láctico). Fueron envasadas en bolsas de polietileno y almacenadas a 0, 4 y 8°C. A diferentes tiempos se realizaron recuentos de Microorganismos Aerobios Totales, Pseudomonas sp y Enterobacterias, (37°C, 24-48 h). Las cinéticas microbianas se analizaron mediante modelos matemáticos. La determinación del CS se realizó mediante un sistema de visión computacional. En este caso se evaluaron también los tratamientos con luz UVC (Ti) y aceite de romero (Tr) por separado. Mediante el análisis de la cinética de evolución del CS de las carnes y la apreciación visual (AV) del consumidor se determinó un valor límite de variación de color que permitió estimar la VU sensorial. Con respecto a los resultados de los EM, en ambos cortes los recuentos finales fueron menores en las muestras Tir que en las C, con buen ajuste de los datos experimentales a los modelos. Se consideró fin de la VU microbiológica al tiempo en que Pseudomonas sp alcanzó un desarrollo de 107 UFC/cm2, con lo cual se determinó que las muestras C tuvieron una VU de 5, 14 y más de 15 días, a 8, 4 y 0°C, respectivamente. Para las muestras Tir, se logró aumentar estos tiempos, con valores de 8, más de 16 y 20 días. En cuanto a los cambios de CS, todas las muestras mostraron decoloración durante el almacenamiento, siendo ésta más rápida en el caso del bife. Las muestras Ti no presentaron diferencias significativas con las muestras C y las muestras Tr y Tir mostraron menores variaciones de color con respecto a las C. Mediante la AV de las muestras se cuantificó el límite de CS aceptable por el consumidor, el cual fue ΔE=8. A partir de este valor y de las cinéticas de cambio de color, la VU sensorial resultó de 3, 6 y 10 días para las muestras C y 3, 8 y 14 días para las muestras Tir a 8, 4 y 0°C, respectivamente. Concluimos que la aplicación combinada de los tratamientos utilizados permitió extender la VU del producto en términos de aceptabilidad sensorial, color y estabilidad microbiana. &nbsp

Identification of a non-host semiochemical from tick-resistant donkeys (Equus asinus) against Amblyomma sculptum ticks

Amblyomma sculptum is a tick affecting animal and human health across Argentina, Bolivia, Paraguay and Brazil. Donkeys, Equus asinus, are known to be resistant to A. sculptum, suggesting that they can produce non-host tick semiochemicals (allomones), as already demonstrated for some other vertebrate host/pest interactions, whereas horses, Equus caballus, are considered as susceptible hosts. In this study, we tested the hypothesis that donkeys produce natural repellents against A. sculptum, by collecting sebum from donkeys and horses, collecting the odour from sebum extracts, and identifying donkey-specific volatile compounds by gas chromatography (GC) and coupled GC-mass spectrometry (GC–MS). From the complex collected blends, five main compounds were identified in both species. Hexanal, heptanal and (E)-2-decenal were found predominantly in donkey extracts, whilst ethyl octanoate and ethyl decanoate were found predominantly in horse extracts. One compound, (E)-2-octenal, was detected exclusively in donkey extracts. In Y-tube olfactometer bioassays 36 different A. sculptum nymphs were tested for each extract, compound and concentration. The dry sebum extracts and the compounds identified in both species induced neither attraction nor repellency. Only (E)-2-octenal, the donkey-specific compound, displayed repellency, with more nymphs preferring the arm containing the solvent control when the compound was presented in the test arm across four concentrations tested (p < 0.05, Chi-square test). A combination of a tick attractant (ammonia) and (E)-2-octenal at 0.25M also resulted in preference for the control arm (p < 0.05, Chi-square test). The use of semiochemicals (allomones) identified from less-preferred hosts in tick management has been successful for repelling brown dog ticks, Rhipicephalus sanguineus sensu lato from dog hosts. These results indicate that (E)-2-octenal could be used similarly to interfere in tick host location and be developed for use in reducing A. sculptum numbers on animal and human hosts

Environmental Modeling and Exposure Assessment of Sediment-Associated Pyrethroids in an Agricultural Watershed

Synthetic pyrethroid insecticides have generated public concerns due to their increasing use and potential effects on aquatic ecosystems. A modeling system was developed in this study for simulating the transport processes and associated sediment toxicity of pyrethroids at coupled field/watershed scales. The model was tested in the Orestimba Creek watershed, an agriculturally intensive area in California' Central Valley. Model predictions were satisfactory when compared with measured suspended solid concentration (R2 = 0.536), pyrethroid toxic unit (0.576), and cumulative mortality of Hyalella azteca (0.570). The results indicated that sediment toxicity in the study area was strongly related to the concentration of pyrethroids in bed sediment. Bifenthrin was identified as the dominant contributor to the sediment toxicity in recent years, accounting for 50–85% of predicted toxicity units. In addition, more than 90% of the variation on the annual maximum toxic unit of pyrethroids was attributed to precipitation and prior application of bifenthrin in the late irrigation season. As one of the first studies simulating the dynamics and spatial variability of pyrethroids in fields and instreams, the modeling results provided useful information on new policies to be considered with respect to pyrethroid regulation. This study suggested two potential measures to efficiently reduce sediment toxicity by pyrethroids in the study area: [1] limiting bifenthrin use immediately before rainfall season; and [2] implementing conservation practices to retain soil on cropland

Frustration - how it can be measured

A misfit parameter is used to characterize the degree of frustration of ordered and disordered systems. It measures the increase of the ground-state energy due to frustration in comparison with that of a relevant reference state. The misfit parameter is calculated for various spin-glass models. It allows one to compare these models with each other. The extension of this concept to other combinatorial optimization problems with frustration, e.g. p-state Potts glasses, graph-partitioning problems and coloring problems is given.Comment: 10 pages, 1 table, no figures, uses revtex.st