RESUMEN
Policy makers often must rely on the cumulative impact of independent actions taken by local landowners to achieve environmental goals. The connection between policy, regulation, and local action, however, is often not well understood and, thus, the impact of proposed policies may be difficult to predict. In this study we evaluate the effectiveness of alternative policy scenarios for agricultural set aside programs (e.g., the conservation reserve program administered by the United States Department of Agriculture) in reducing nonpoint pollution. Two alternative policy scenarios are developed and analyzed; one based on the erodibility index (detachment), the other sediment yield (transport). An estimate of the cumulative impact of associated land use change on nonpoint pollution is made using the AGNPS distributed parameter watershed model. This work is completed within the Cypress Creek watershed in southern Illinois. An analysis of the resulting data suggests that the most efficacious regulatory strategy for achieving nonpoint water pollution goals depends, in part, on place-specific land use patterns. This conclusion provides a solid argument for place-based regulatory strategies.
Asunto(s)
Conservación de los Recursos Naturales , Técnicas de Apoyo para la Decisión , Monitoreo del Ambiente/métodos , Contaminación Ambiental/análisis , Formulación de Políticas , Agricultura , Animales , Sedimentos Geológicos , Humanos , Evaluación de Programas y Proyectos de Salud , Política PúblicaRESUMEN
A semi-isolated cockroach heart preparation was used to rapidly determine the activity of cobra cardiotoxin, monitored as a direct response on heart rate. This preparation produced a dose-response curve in the presence of active cardiotoxin and demonstrated that cardiotoxin retained its biological activity after boiling, although cardiotoxin activity was destroyed by heating in the presence of dithiothreitol. Experiments that cross-linked radiolabeled cardiotoxin to solubilized cockroach heart membranes suggested that cardiotoxin bound specifically to a 59,000 mol. wt membrane protein in this tissue.
Asunto(s)
Bioensayo , Proteínas Cardiotóxicas de Elápidos/análisis , Cucarachas/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Animales , Proteínas Cardiotóxicas de Elápidos/metabolismo , Proteínas Cardiotóxicas de Elápidos/farmacología , Reactivos de Enlaces Cruzados , Proteínas de la Membrana/metabolismo , Peso Molecular , Miocardio/metabolismo , SuccinimidasRESUMEN
Histochemical techniques have been employed to characterize enzymatic activity in the mesocoxal muscles of the cockroach, Periplaneta americana. Through our studies of the enzymes myosin-ATPase, NADH reductase, succinic dehydrogenase (SDH), and lactic dehydrogenase (LDH), we were able to classify fibers within these muscles according to criteria established for muscle fibers of vertebrates. Many of the mesocoxal muscles possess two different and distinct populations of fibers, whereas the remaining muscles are homogeneous with respect to their constituent fibers. The data presented here indicate biochemical heterogeneity for muscles of differing structural and functional features and possible neurotrophic influences upon oxidative enzymes and myosin-ATPase isozymes.