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1.
PLoS One ; 3(8): e3052, 2008 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-18725962

RESUMEN

BACKGROUND: A key argument in favor of conserving biodiversity is that as yet undiscovered biodiversity will yield products of great use to humans. However, the link between undiscovered biodiversity and useful products is largely conjectural. Here we provide direct evidence from bioassays of endophytes isolated from tropical plants and bioinformatic analyses that novel biology will indeed yield novel chemistry of potential value. METHODOLOGY/PRINCIPAL FINDINGS: We isolated and cultured 135 endophytic fungi and bacteria from plants collected in Peru. nrDNAs were compared to samples deposited in GenBank to ascertain the genetic novelty of cultured specimens. Ten endophytes were found to be as much as 15-30% different than any sequence in GenBank. Phylogenetic trees, using the most similar sequences in GenBank, were constructed for each endophyte to measure phylogenetic distance. Assays were also conducted on each cultured endophyte to record bioactivity, of which 65 were found to be bioactive. CONCLUSIONS/SIGNIFICANCE: The novelty of our contribution is that we have combined bioinformatic analyses that document the diversity found in environmental samples with culturing and bioassays. These results highlight the hidden hyperdiversity of endophytic fungi and the urgent need to explore and conserve hidden microbial diversity. This study also showcases how undergraduate students can obtain data of great scientific significance.


Asunto(s)
Fenómenos Fisiológicos Bacterianos , Conservación de los Recursos Naturales , Hongos/genética , Bacterias/clasificación , Biodiversidad , Evolución Molecular , Hongos/clasificación , Paraguay , Perú , Filogenia , Plantas/microbiología , ARN Bacteriano/genética , ARN Bacteriano/aislamiento & purificación , ARN de Hongos/genética , ARN de Hongos/aislamiento & purificación
2.
Environ Monit Assess ; 76(1): 19-41, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12125748

RESUMEN

Resource exploitation in lowland tropical forests is increasing and causing loss of biodiversity. Effective evaluation and management of the impacts of development on tropical forests requires appropriate assessment and monitoring tools. We propose the use of 0.1-ha multi-scale, modified Whittaker plots (MWPs) to assess and monitor vegetation in lowland tropical rainforests. We established MWPs at 4 sites to: (1) describe and compare composition and structure of the sites using MWPs, (2) compare these results to those of 1-ha permanent vegetation plots (BDPs), and (3) evaluate the ability of MWPs to detect changes in populations (statistical power). We recorded more than 400 species at each site. Species composition among the sites was distinctive, while mean abundance and basal area was similar. Comparisons between MWPs and BDPs show that they record similar species composition and abundance and that both perform equally well at detecting rare species. However, MWPs tend to record more species, and power analysis studies show that MWPs were more effective at detecting changes in the mean number of species of trees > or = 10 cm in diameter at breast height (dbh) and in herbaceous plants. Ten MWPs were sufficient to detect a change of 11% in the mean number of herb species, and they were able to detect a 14% change in the mean number of species of trees > or =10 cm dbh. The value of MWPs for assessment and monitoring is discussed, along with recommendations for improving the sampling design to increase power.


Asunto(s)
Monitoreo del Ambiente/métodos , Desarrollo de la Planta , Árboles/crecimiento & desarrollo , Clima Tropical , Conservación de los Recursos Naturales/métodos , Conservación de los Recursos Naturales/estadística & datos numéricos , Recolección de Datos/métodos , Monitoreo del Ambiente/estadística & datos numéricos , Cooperación Internacional , Perú , Proyectos de Investigación
3.
Science ; 295(5555): 666-9, 2002 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-11809969

RESUMEN

The high alpha-diversity of tropical forests has been amply documented, but beta-diversity-how species composition changes with distance-has seldom been studied. We present quantitative estimates of beta-diversity for tropical trees by comparing species composition of plots in lowland terra firme forest in Panama, Ecuador, and Peru. We compare observations with predictions derived from a neutral model in which habitat is uniform and only dispersal and speciation influence species turnover. We find that beta-diversity is higher in Panama than in western Amazonia and that patterns in both areas are inconsistent with the neutral model. In Panama, habitat variation appears to increase species turnover relative to Amazonia, where unexpectedly low turnover over great distances suggests that population densities of some species are bounded by as yet unidentified processes. At intermediate scales in both regions, observations can be matched by theory, suggesting that dispersal limitation, with speciation, influences species turnover.


Asunto(s)
Ecosistema , Árboles , Clima Tropical , Ecuador , Ambiente , Análisis de Fourier , Modelos Biológicos , Panamá , Perú , Probabilidad , Árboles/clasificación , Árboles/crecimiento & desarrollo
4.
Rev. costarric. cardiol ; 2(3): 19-28, sept.-dic. 2000. ilus
Artículo en Español | LILACS | ID: lil-297362

RESUMEN

En los últimos años se han redoblado los esfuerzos para disminuir y en el mejor de los casos evitar el daño al músculo cardíaco durante el infarto agudo. Las drogas trombolíticas han contribuido positivamente al respecto. Sin embargo, nace la necesidad de buscar formas alternas de tratamiento que proporcionen un más rápido y efectivo restablecimiento de la circulación coronaria. Nos referimos a la Angioplastía Primaria como tratamiento inicial del infarto agudo. Presentamos los primeros 16 casos con infarto agudo al miocardio en curso, tratados con Angioplastía Primaria, 15 de 16 pacientes evolucionaron en forma satisfactoria, sin complicaciones del infarto que al procedimiento de angioplastía per-se. De esta manaera reafirmamos la utilidad de esta nueva forma de tratamiento, planteando una alternativa terapéutica adicional en beneficio de los pacientes que están sufriendo un infarto agudo al miocardio.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Angioplastia , Infarto del Miocardio , Panamá
7.
Rev. costarric. cardiol ; 1(1): 22-8, sept. 1999. ilus
Artículo en Español | LILACS | ID: lil-297350

RESUMEN

El papel de las plaquetes en la protegénesis de los síndromes coronarios agudos es cada vez más evidente. El manejo farmacológico de los mismos era inicialmente orientado a contrarestar un proceso trombotico fibrino-específico sin considerarse la importante participación de las plaquetas en la fisiopatología de los mismos. Desde 1994 se integran al tratamiento los inhibidores de las glicoproteínas IIb IIIa como antiplaquetarios específicos, obteniéndose una discriminación significativa en la morbi-mortalidad cardio vascular. Queremos presentar nuestra experincia preliminar con el uso de estos fármacos en pacientes de alto riesgo


Asunto(s)
Humanos , Persona de Mediana Edad , Plaquetas/patología , Enfermedad Coronaria , Heparina/uso terapéutico , Inhibidores de Agregación Plaquetaria/análisis , Recuento de Plaquetas , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria , Factores de Riesgo , Panamá
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