886 research outputs found
Characterizing patterns of genomic variation in the threatened Utah prairie dog: Implications for conservation and management
Utah prairie dogs (Cynomys parvidens) are federally threatened due to eradication campaigns, habitat destruction, and outbreaks of plague. Today, Utah prairie dogs exist in small, isolated populations, making them less demographically stable and more susceptible to erosion of genetic variation by genetic drift. We characterized patterns of genetic structure at neutral and putatively adaptive loci in order to evaluate the relative effects of genetic drift and local adaptation on population divergence. We sampled individuals across the Utah prairie dog species range and generated 2,955 single nucleotide polymorphisms (SNPs) using double digest restriction site associated DNA sequencing (ddRAD). Genetic diversity was lower in low elevation sites compared to high elevation sites. Population divergence was high among sites and followed an isolation-by-distance (IBD) model. Our results indicate that genetic drift plays a substantial role in the population divergence of the Utah prairie dog, and colonies would likely benefit from translocation of individuals between recovery units, which are characterized by distinct elevations, despite the detection of environmental associations with outlier loci. By understanding the processes that shape genetic structure, better informed decisions can be made with respect to the management of threatened species to ensure that adaptation is not stymied
Zika Virus, Elevation, and Transmission Risk
Introduction: Zika virus has appeared in the Americas in the form of a major outbreak, and is now known to cause birth defects when pregnant women are infected. As a result, the Centers for Disease Control and Prevention issued travel guidelines, in the form of an elevational risk definition: destinations below 2000m are considered as at-risk.
Methods: We explored the distribution of known Zika virus vector mosquito species in relation to climatic conditions, elevation, latitude, and air traffic connections to the United States.
Results: In view of the tropical and subtropical nature of the mosquito species that are the primary Zika virus vectors, we point out that climate varies rather dramatically with respect to elevation and latitude, such that a single elevational criterion will be a poor predictor of potential for transmission.
Discussion: We suggest an initial adjustment would consider latitude in addition to elevation; a more definitive, quantitative analysis of risk would consider variables of ecology, climate, human condition, and connectivity of areas
Potential effect of prior raccoonpox virus infection in raccoons on vaccinia-based rabies immunization
<p>Abstract</p> <p>Background</p> <p>The USDA, Wildlife Services cooperative oral rabies vaccination (ORV) program uses a live vaccinia virus-vectored (genus <it>Orthopoxvirus</it>) vaccine, Raboral V-RG<sup>® </sup>(V-RG), to vaccinate specific wildlife species against rabies virus in several regions of the U.S. Several naturally occurring orthopoxviruses have been found in North America, including one isolated from asymptomatic raccoons (<it>Procyon lotor</it>). The effect of naturally occurring antibodies to orthopoxviruses on successful V-RG vaccination in raccoons is the focus of this study.</p> <p>Results</p> <p>Overall, raccoons pre-immunized (n = 10) with a recombinant raccoonpox virus vaccine (RCN-F1) responded to vaccination with V-RG with lower rabies virus neutralizing antibody (VNA) titers than those which were not pre-immunized (n = 10) and some failed to seroconvert for rabies VNA to detectable levels.</p> <p>Conclusion</p> <p>These results suggest that the success of some ORV campaigns may be hindered where raccoonpox virus or possibly other orthopoxvirus antibodies are common in wildlife species targeted for ORV. If these areas are identified, different vaccination strategies may be warranted.</p
Lulo la selva.
Se describe el proceso de obtención de la variedad la Selva de lulo, Solanum quitoense, su origen y el proceso de fitomejoramiento de la variedad, las características botánicas y agronómicas relevantes, las condiciones agroindustriales de adaptación, el rendimiento y ciclo biológico de la planta. Se indica el manejo agronómico del cultivo, el control de enfermedades y plagas, las operaciones de cosecha, postcosecha y la utilización del productoLulo La Selva, primer lulo mejorado para Colombi
Fluorescent biomarkers demonstrate prospects for spreadable vaccines to control disease transmission in wild bats
Vaccines that autonomously transfer among individuals have been proposed as a strategy to control infectious diseases within inaccessible wildlife populations. However, rates of vaccine spread and epidemiological efficacy in real-world systems remain elusive. Here, we investigate whether topical vaccines that transfer among individuals through social contacts can control vampire bat rabies—a medically and economically important zoonosis in Latin America. Field experiments in three Peruvian bat colonies, which used fluorescent biomarkers as a proxy for the bat-to-bat transfer and ingestion of an oral vaccine, revealed that vaccine transfer would increase population-level immunity up to 2.6 times beyond the same effort using conventional, non-spreadable vaccines. Mathematical models showed that observed levels of vaccine transfer would reduce the probability, size and duration of rabies outbreaks, even at low but realistically achievable levels of vaccine application. Models further predicted that existing vaccines provide substantial advantages over culling bats—the policy currently implemented in North, Central and South America. Linking field studies with biomarkers to mathematical models can inform how spreadable vaccines may combat pathogens of health and conservation concern before costly investments in vaccine design and testing
Murine Typhus in Child, Yucatan, Mexico
A case of murine typhus in Yucatan was diagnosed in a child with nonspecific signs and symptoms. The finding of Rickettsia typhi increases the number of Rickettsia species identified in Yucatan and shows that studies are needed to determine the prevalence and incidence of rickettsioses in Mexico
Supervivencia en niños de muy bajo peso al nacimiento, 1996-2004
El objetivo de esta investigación fue establecer la probabilidad de supervivencia y la morbilidad de los neonatos con muy bajo peso al nacimiento, en un hospital de tercer nivel de Colombia. Para este fin se evaluaron todos los neonatos nacidos vivos con peso inferior a 1500g en el Hospital General de Medellín, entre 1996 y 2004. Resultados: durante el período de estudio ingresaron 1443 neonatos. 54% de las madres recibió esteroides antenatales y 17.1% de los neonatos recibió surfactante pulmonar. La media del tiempo de supervivencia de los neonatos con peso inferior a 1000g fue menor a un día. Ningún neonato de 23 semanas o menos egresó vivo. La probabilidad de ingresar a la Unidad de Cuidado Intensivo Neonatal fue significativamente menor entre los neonatos menores de 1000g, que entre los neonatos de 1000 a 1490 g, y el RR = 0.54 (IC95%: 0.44-0.65). La mortalidad de este grupo fue mayor de manera estadísticamente significativa, que entre los de 1000 a 1490 g, y el RR = 3.8 (IC 95%=3.3-4.3). La fracción atribuible en la población (RAP%) debida al extremo bajo peso al nacer fue de 47.8%. AbstractThe aim of this trial was to measure the neonatal survival rate and the morbidity of the very low birth weight infants in a third level hospital in Colombia. In the Hospital General of Medellín were evaluated all the neonates born between 1996 and 2004 with a birth weight less than 1500g. Results: 1443 neonates were enrolled to this cohorte-study 54% of the mothers got antenatal steroids and 17.1% of the neonates got pulmonary surfactant. The neonates with a birth weight less than 1000g had a survival time median less than one day. No one neonate with 23 weeks or less of gestational age went away live. The likelihood of enter to the neonatal intensive care unit was significant lower in neonates with a birth weight less than 1000g that in the neonates with a birth weight between 1000 to 1490 g, RR = 0.54 (CI95%: 0.44-0.65), the mortality in the first group was greater than in the second group, RR = 3.8 (CI95%: 3.3-4.3). The percentage of attributable risk in the population (%PAR) was 47.8% caused to have a birth weigh lower than 1000 g. Conclusions: There is a lower risk to enter at the neonatal intensive care unit in those neonates with a birth weight less than 1000g, and the survival rate of this population is diminished because of this. The high likelihood of dying due to the extreme low birth weight must call the attention of the sanitary authorities, because this evaluates of indirect way the quality of attention that receive the obstetrical patients. Cohort studies should to carry out in this population for evaluating the long time prognosis and would allow design policies of maternal and neonatal health.Keywords: very low birth weight infant, neonatal intensive care unit, neonatal mortality, survival rate, pulmonary surfactant, neonatal respiratory distress syndrome, bronchopulmonary dysplasia
Competitividad de la fruta fresca de exportación: el caso de uvas de mesa, manzanas y peras.
Resumen (Spanish, English)131 p.Este estudio presenta un análisis de la competitividad alcanzada en los principales mercados de destino por las exportaciones nacionales de uva de mesa, manzanas y peras frescas. La metodología utilizada se basa en el programa computacional “Competitive Analysis of Nation” (CAN), creado por CEPAL, la cual permite obtener una visión dinámica de las situaciones de competitividad de los productos en los mercados estudiados. En el desarrollo del estudio, se expone información necesaria para entender la estructura mundial de comercio, tanto en lo referido a los mercados importadores de estos productos, como a los principales países abastecedores, entre ellos Chile. Se presenta, además, los antecedentes necesarios para entender la situación comercial de la fruticultura chilena durante la última década, profundizando esta información para la estructura exportadora de los productos estudiados. Con esta información y mediante la metodología utilizada, se determina la competitividad de cada producto en cada mercado. De esta manera, al conocer la situación competitiva en cada caso (producto-mercado), se sugieren posibles estrategias comerciales a seguir con el fin de mejorar la competitividad de la industria. En uva de mesa, destaca la competitividad medida en las exportaciones a los mercados de Holanda y Brasil. Las exportaciones
destinadas a los EUA (70% de lo exportado anualmente por Chile) son poco competitivas. En manzanas y peras, las exportaciones hacia Arabia Saudita resultan competitivas, a la vez, para ambos productos, se están perdiendo oportunidades competitivas en el mercado holandés
Frequency and Clinical Features of Dengue Infection in a Schoolchildren Cohort from Medellin, Colombia
To determine the incidence of dengue infection, we established active surveillance of febrile episodes in a cohort of schoolchildren from three schools in Medellin, Colombia. We followed a cohort of 2,379 schoolchildren in 2010 and followed 1,840 of these children the following year. During the follow-up time, 264 schoolchildren displayed 297 febrile episodes; of these, 23 episodes (7.7%) were caused by acute dengue infection. All four dengue serotypes were found, and all of the cases were mild. The most common symptoms in the dengue cases compared with those in other febrile illness were asthenia (96% versus 87%), anorexia (78% versus 57%), rhinorrhea (65.2% versus 58%), abdominal pain (56.5% versus 47.8%), arthralgia (43% versus 33%), and positive tourniquet test (13% versus 3%). This difference was not statistically significant. Pulse was elevated, and systolic arterial pressure was lower in dengue cases compared with other febrile illness (P<0.05). Mosquito indexes were determined in 8 children’s houses and in the schools. Aedes aegypti adults were found in both households and in schools, whereas Aedes aegypti larvae were found only in schools. These results showed an elevated dengue frequency in children, with symptoms similar to those of other febrile illness and transmission risk in households and schools
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