ABSTRACT
Introduced species offer unique opportunities to study evolution in new environments, and some provide opportunities for understanding the mechanisms underlying macroecological patterns. We sought to determine how introduction history impacted genetic diversity and differentiation of the house sparrow (Passer domesticus), one of the most broadly distributed bird species. We screened eight microsatellite loci in 316 individuals from 16 locations in the native and introduced ranges. Significant population structure occurred between native than introduced house sparrows. Introduced house sparrows were distinguished into one North American group and a highly differentiated Kenyan group. Genetic differentiation estimates identified a high magnitude of differentiation between Kenya and all other populations, but demonstrated that European and North American samples were differentiated too. Our results support previous claims that introduced North American populations likely had few source populations, and indicate house sparrows established populations after introduction. Genetic diversity also differed among native, introduced North American, and Kenyan populations with Kenyan birds being least diverse. In some cases, house sparrow populations appeared to maintain or recover genetic diversity relatively rapidly after range expansion (<50 years; Mexico and Panama), but in others (Kenya) the effect of introduction persisted over the same period. In both native and introduced populations, genetic diversity exhibited large-scale geographic patterns, increasing towards the equator. Such patterns of genetic diversity are concordant with two previously described models of genetic diversity, the latitudinal model and the species diversity model.
Subject(s)
Genetic Variation/genetics , Sparrows/genetics , Animals , Bayes Theorem , Microsatellite Repeats/genetics , Sparrows/classificationABSTRACT
This work reports on a preliminary study carried out in Nicaragua to build a profile of the contamination of cow's milk with 10 organochlorine pesticides and make recommendations based on the findings. Between December 1993 and March 1994, milk samples were collected from 48 different sites in the country. The samples were analyzed for residues of hexachlorobenzene (HCB), alpha-BHC, lindane, aldrin, dieldrin, oxychlordane, heptachlor epoxide, and the principal metabolites of DDT (p,p'-TDE, p,p'-DDE, and p,p'-DDT) by means of solid-phase extraction from milk fat, and the quantity of the residues was determined by gas chromatography with electron capture detection. Heptachlor epoxide was found in 1 milk sample, dieldrin in 1, lindane in 3, oxychlordane in 3, alpha-BHC in 3, aldrin in 6, HCB in 9, and metabolites of DDT in 39 (81% of the samples). The six samples most heavily contaminated with by-products of DDT came from the departments of León and Chinandega, in the Pacific region, where there used to be intensive cotton production. The highest concentration was found in the sample from Malpaisillo, with 1105 micrograms of pesticide per kg of milk fat. The authors recommend that studies should be done so that the risk of contamination of other food products can be estimated, and that the public's health should be protected through strict control of the production or importation, storage, sale, and use of organochlorine pesticides.
Subject(s)
Food Contamination , Hydrocarbons, Chlorinated , Insecticides/analysis , Milk/chemistry , Pesticide Residues/analysis , Animals , Global Health , Insect Control/legislation & jurisprudence , Nicaragua , Pilot ProjectsABSTRACT
En el presente estudio se informa acerca de las circunstancias en que son mordidos por can los niños que acuden a una consulta de urgencias de un hospital general. Se estudiaron 63 niños; el sexo masculino predominó en una relación 2:1, los escolares fueron los más afectados con 50 por ciento; la cabeza fue el sitio de la lesión en 38 por ciento; hubo un caso de una mordedura fatal y dos en los párpados. Se comenta la deficiente educación en el cuidado y manejo de los perros que se refleja en el elevado número de aplicaciones de vacuna antirrábica.
Subject(s)
Humans , Animals , Male , Female , Infant , Child, Preschool , Adolescent , Dogs , Wounds and Injuries/epidemiology , Dogs , Face , HeadABSTRACT
Se presentan las indicaciones y resultados de 1552 amniocentesis realizadas entre 1987 y 1992 en nuestro servicio de fisiopatología fetal. La indicación más frecuente es la edad materna avanzada (35 años) que supone un 61.40 por ciento de los casos. La mayoría de las amniocentesis se realizaron entre 14-16 semanas de gestación. Se encontraron 41 anomalias cromosómicas (2.64 por ciento): 32 aneuploidías y nueve alteraciones estructurales. Entre las aneuploidías destacan por orden de frecuencia, 15 casos de trisomía 21 y nueve casos de trisomía 18. Los grupos con mayor riesgo de alteración cromosómica son los portadores de translocación cromosómicas (91,23 por ciento) y el grupo de sospecha ecográfica de malformación (10,75 por ciento). El análisis citogenético resultó posible en el 95,74 por ciento de los casos. La tasa de fracasos de cultivo en 1992 resultó ser del 2,50 por ciento (AU)
Subject(s)
Humans , Female , Pregnancy , Amniocentesis/statistics & numerical data , Chromosome Aberrations , Prenatal Diagnosis/methods , Trisomy/diagnosis , Down Syndrome/diagnosis , Gestational Age , Treatment OutcomeABSTRACT
Se presentan las indicaciones y resultados de 1552 amniocentesis realizadas entre 1987 y 1992 en nuestro servicio de fisiopatología fetal. La indicación más frecuente es la edad materna avanzada (35 años) que supone un 61.40 por ciento de los casos. La mayoría de las amniocentesis se realizaron entre 14-16 semanas de gestación. Se encontraron 41 anomalias cromosómicas (2.64 por ciento): 32 aneuploidías y nueve alteraciones estructurales. Entre las aneuploidías destacan por orden de frecuencia, 15 casos de trisomía 21 y nueve casos de trisomía 18. Los grupos con mayor riesgo de alteración cromosómica son los portadores de translocación cromosómicas (91,23 por ciento) y el grupo de sospecha ecográfica de malformación (10,75 por ciento). El análisis citogenético resultó posible en el 95,74 por ciento de los casos. La tasa de fracasos de cultivo en 1992 resultó ser del 2,50 por ciento
