Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R2>0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region.
RESUMEN.Se analizaron aspectos reproductivos de la raya eléctrica Narcine bancroftii, capturada como bycatch con una red playera de cerco en dos playas del sector de El Rodadero, Santa Marta, Caribe colombiano. Los ejemplares fueron sexados, pesados y medidos, se identificó su estado de desarrollo gonadal mediante características morfológicas externas e internas. Se evaluó la condición reproductiva con el comportamiento de los índices biológicos (gonadosomático IGS y hepatosomático IHS) y la talla a la madurez sexual (l 50% ). Los resultados obtenidos mostraron que el IGS tiene un máximo anual entre septiembre y diciembre cuando probablemente ocurre la cópula. El IHS presentó su mayor valor en enero, cuando termina su periodo reproductivo. La talla media de madurez en hembras fue de 32,2 cm y en machos de 20,2 a 22,9 cm. El período de gestación es de cuatro meses y las crías nacen de febrero a abril. Palabras clave: raya eléctrica, reproducción, fecundidad, mar Caribe, Colombia.Reproduction of the electric ray Narcine bancroftii (Torpediniformes: Narcinidae) in Santa Marta, Colombian Caribbean ABSTRACT. This paper provides information about reproductive aspects of the electric ray Narcine bancroftii, caught as bycatch with beach seines in two beaches of El Rodadero, Santa Marta, Colombian Caribbean, between August (2005) and October (2006). The electric rays obtained were separate by sex, weighed and measured; the development of reproductive stage was identified by external and internal characteristics. The reproductive condition was determinate by (gonadosomatic GSI and hepatosomatic HSI) indexes and the size at sexual maturity (l 50% ). The results showed that the GSI has one peak at year between September and December when probably the copulation carried out, the HSI presented its highest value in January, which corresponds to the end of the reproductive period. The size at sexual maturity was 32.2 cm in females and it was between 20.2 and 22.9 cm in males. We propose that the gestation period extends during four months, starting with the birth of individuals in February and finishing in April.
RESUMEN.Se presentan los resultados de la condición reproductiva y espectro trófico de cuatro batoideos capturados incidentalmente en la pesca artesanal de dos sectores del mar Caribe colombiano, entre agosto 2005 y septiembre 2006. Se evaluó un total 570 lances en Playa Salguero y 149 en Don Jaca, efectuándose entre 12 y 26 días de muestreo mensuales. Se obtuvo abundancias totales y relativas de los batoideos capturados y se estableció la proporción sexual, así como la representatividad de cada estado de desarrollo gonadal. De Narcine bancroffti se evaluó 176 ejemplares (127 hembras y 49 machos); 167 Rhinobatos percellens (83 hembras y 84 machos); 237 Urotrygon venezuelae (126 hembras y 111 machos) y para Dasyatis guttata se evaluó 119 individuos (58 hembras y 61 machos). A pesar que los ejemplares capturados de las cuatro especies mostraron representatividad de todos los estadios de desarrollo gonadal, las etapas inmaduro (I) y maduro (III), fueron las mejor representadas. Adicionalmente, por la proporción sexual obtenida, parece no haber segregación espacio-temporal marcada. La dieta en general estuvo constituida por crustáceos, anélidos y teleósteos, evidenciando preferencias alimentarias únicas, lo cual les permite evitar competencia interespecífica entre batoideos. Palabras clave: pesca artesanal, biología reproductiva, hábitos tróficos, Batoideos, mar Caribe, Colombia. Trophic and reproductive aspects of some batoids caught at Santa Marta in the Colombian Caribbean SeaABSTRACT. This paper presents the reproductive condition and feeding spectrum of four batoid species caught as bycatch by artisanal fishermen in two sectors of the Colombian Caribbean Sea between August 2005 and September 2006. Specimens were evaluated from a total of 570 hauls done off Salguero beach and 149 off Don Jaca, with sampling periods of 12 to 26 days per month. The total and relative abundance of the batoids caught were determined, as were the sexual proportion and representativity of each sexual maturity stage. Specimens sampled were: 176 Narcine bancroftii (127 females, 49 males); 167 Rhinobatos percellens (83 females, 84 males); 237 Urotrygon venezuelae (126 females, 111 males), and 119 Dasyatis guttata (58 females, 61 males). Although specimens from all stages of maturity were caught, the immature (I) and mature (III) stages were dominant. Based on the sexual proportion obtained, no marked spatial-temporal segregation was observed. The overall diet consisted of crustaceans, annelids, and teleosts, with unique food preferences that allow the sampled species to avoid interspecific competition.
As for most batoid species, little is known about the basic biology of the Venezuela round stingray Urotrygon venezuelae (Urotrygonidae). This study presents information about the reproductive biology of the species, including fecundity, embryonic development stage, relationship between maternal size and fecundity, gonadosomatic (GSI) and hepatosomatic (HSI) indices, sex ratios, maturity size and size at birth. With all this information, a preliminary reproductive cycle is proposed. A total of 269 specimens were caught with beach seine in Salguero beach, Colombian Caribbean Sea, between August 2005 and October 2006. We propose for U. venezuelae a biological cycle with three reproductive peaks: November-December, March-April and August. Size at sexual maturity was calculated in 176 mm (total length) for females and 227 mm for males; fecundity ranged between one and six embryos per female. We found that cloacal diameter and liver weight were better predictors for fecundity than total length for U. venezuelae.
There is an urgent need for the development of new antibiotics. Here, we describe the inhibitory activity of new quinone compounds against methicillin-resistant Staphylococcus aureus (ATCC® 43300), methicillin-sensitive S. aureus (ATCC® 29213), and two clinical isolates from Chile (ISP-213 and ISP-214). We observed 99.9% reduction in viability within 2 h of exposure without the cultures exhibiting any post-antibiotic effect, which was twice the kinetics to that observed with vancomycin. These clinical isolates did not acquire resistance to these quinone derivatives during the course of our study. We found that these compounds protected larvae of the greater wax moth, sp. Galleria mellonella, from infection by these MRSA clinical strains as effectively as vancomycin. These quinone derivatives are potential drug candidates worth further development.
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