47 research outputs found
BREEDING BEHAVIOR OF A REINTRODUCED PAIR OF ANDEAN CONDOR (VULTUR GRYPHUS) IN THE CENTRAL ANDES OF COLOMBIA
Abstract · Between 1989–2013, 69 Andean Condors (Vultur gryphus) were reintroduced in eight sites in the Andes of Colombia. Due to the lack of monitoring programs, little is known about the ecology and biology of these reintroduced populations. We present the first observations on a reintroduced breeding pair. For 36 months, we examined the breeding behavior of a pair of condors in a nest cave in the central Andes of Colombia. In June 2013, we observed a chick of about 6–7 months of age in the nest cave. The most remarkable outcomes of these observations are (1) that females spend more time guarding the chick whereas (2) males focus on guarding the nest cave. While the chick was in the nest cave (80 h of observations), the female was present in the vicinity of the nest cave and attended the chick for a longer time period than the male. However, in the absence of a chick or eggs (880 h of observations), the male was observed more often in the vicinity of the nest cave than the female. Nevertheless, we found no significant differences in vigilance patterns between the sexes. Intraspecific interactions of the Andean Condor with other raptors in the area were recorded during the observation period of this study. We make some predictions on the timing of reproduction of condors based on this reintroduced pair in Colombia and compare them with those reported elsewhere. Tracking released populations of condors is essential to ensure the positive impact of reintroduction efforts. Resumen · Comportamiento reproductivo de una pareja reintroducida de Cóndor Andino (Vultur gryphus) en la cordillera Central de Colombia Entre 1989–2013, 69 individuos de Cóndor Andino (Vultur gryphus) fueron liberados en ocho núcleos de repoblación en la región andina de Colombia. Debido a la falta de seguimiento de estas liberaciones, se conoce poco sobre la biología y ecología de la especie en esos núcleos de repoblación. Presentamos la primera información de seguimiento del comportamiento reproductivo de una pareja en los núcleos de repoblación. Por un periodo de 36 meses examinamos el comportamiento reproductivo de esa pareja en un nido encontrado en la cordillera Central de Colombia. En junio de 2013 registramos la presencia de un polluelo de aproximadamente seis a siete meses de edad en el nido. Mientras el polluelo estuvo en el nido (80 h de observación), la hembra permaneció dentro de la vecindad e interactuó por más tiempo con el polluelo en comparación con el macho. En ausencia de polluelo o postura (880 h de observación), el macho permaneció dentro del territorio por un mayor número de horas en comparación con la hembra, aunque estas diferencias no fueron estadísticamente significativas. Registramos interacciones interespecíficas directas entre el Cóndor Andino y rapaces que ingresaron a su área de anidación. El seguimiento de las poblaciones de cóndor liberadas es clave para garantizar el impacto positivo de los esfuerzos de reintroducción como herramienta para la conservación
Cytotoxicity and potential antiviral evaluation of violacein produced by Chromobacterium violaceum
¿Qué hay de nuevo en la evaluación de moléculas con actividad biológica-combretastatinas?
¿Qué hay de nuevo en la evaluación de moléculas con actividad biológica-combretastatinas?
Antitumor and Antiviral Activity of Colombian Medicinal Plant Extracts
Extracts of nine species of plants traditionally used in Colombia for
the treatment of a variety of diseases were tested in vitro for their
potential antitumor (cytotoxicity) and antiherpetic activity. MTT
(Tetrazolium blue) and Neutral Red colorimetric assays were used to
evaluate the reduction of viability of cell cultures in presence and
absence of the extracts. MTT was also used to evaluate the effects of
the extracts on the lytic activity of herpes simplex virus type 2
(HSV-2). The 50% cytotoxic concentration (CC50) and the 50% inhibitory
concentration of the viral effect (EC50) for each extract were
calculated by linear regression analysis. Extracts from Annona
muricata, A. cherimolia and Rollinia membranacea, known for their
cytotoxicity were used as positive controls. Likewise, acyclovir and
heparin were used as positive controls of antiherpetic activity.
Methanolic extract from Annona sp. on HEp-2 cells presented a CC50
value at 72 hr of 49.6x103μg/ml. Neither of the other extracts
examined showed a significant cytotoxicity. The aqueous extract from
Beta vulgaris, the ethanol extract from Callisia grasilis and the
methanol extract Annona sp. showed some antiherpetic activity with
acceptable therapeutic indexes (the ratio of CC50 to EC50). These
species are good candidates for further activity-monitored
fractionation to identify active principles
Cytotoxic and Antiviral Activities of Colombian Medicinal Plant Extracts of the Euphorbia genus
Forty-seven plant extracts of 10 species of the genus Euphorbia
( Euphorbia ceae) used by Colombian traditional healers for the
treatment of ulcers, cancers, tumors, warts, and other diseases, were
tested in vitro for their potential antitumour (antiproliferative and
cytotoxic) and antiherpetic activity. To evaluate the capacity of the
extracts to inhibit the lytic activity of herpes simplex virus type 2
(HSV-2) and the reduction of viability of infected or uninfected cell
cultures, the end-point titration technique (EPTT) and the MTT
[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]
colorimetric assay were used, respectively. The therapeutic index of
the positive extracts for the antiviral activity was determined by
calculating the ratio CC 50 (50% cytotoxic concentration) over IC 50
(50% inhibitory concentration of the viral effect). Five of the 47
extracts (11%) representing 3 out of 10 Euphorbia species (30%)
exhibited antiherpetic action; the highest activity was found in the
leaf/stem water-methanol extracts from E. cotinifolia and E.
tirucalli . The therapeutic indexes of these two plant species
were > 7.1; these extracts exhibited no cytotoxicity. Six extracts
(13%) representing 4 plant species (40%) showed cytotoxic activity. The
highest cytotoxicity was found in the dichloromethane extract obtained
from E. cotinifolia leaves and the CC 50 values for the most
susceptible cell lines, HEp-2 and CHO, were 35.1 and 18.1 mg/ml,
respectively