Los países miembros de la OMC discuten medidas en respuesta al COVID-19 y hacen un llamado a mejorar la transparencia en el comercio agrícola

En la 77ª reunión del Comité de Medidas Sanitarias y Fitosanitarias se abordaron experiencias COVID-19 de los países miembros, se evaluó el Acuerdo de Medidas Sanitarias y Fitosanitarias (Acuerdo MFS) y se examinó una posible declaración de medidas sanitarias y fitosanitarias para la duodécima Reunión Ministeria

Detecting the effects of hydrocarbon pollution in the Amazon forest using hyperspectral satellite images

The global demand for fossil energy is triggering oil exploration and production projects in remote areas of the world. During the last few decades hydrocarbon production has caused pollution in the Amazon forest inflicting considerable environmental impact. Until now it is not clear how hydrocarbon pollution affects the health of the tropical forest flora. During a field campaign in polluted and pristine forest, more than 1100 leaf samples were collected and analysed for biophysical and biochemical parameters. The results revealed that tropical forests exposed to hydrocarbon pollution show reduced levels of chlorophyll content, higher levels of foliar water content and leaf structural changes. In order to map this impact over wider geographical areas, vegetation indices were applied to hyperspectral Hyperion satellite imagery. Three vegetation indices (SR, NDVI and NDVI705) were found to be the most appropriate indices to detect the effects of petroleum pollution in the Amazon forest

Changes in tree and liana communities along successional gradient in a tropical dry forest in south-eastern Brazil

We investigated changes in species composition and structure of tree and liana communities along a successional gradient in a seasonally dry tropical forest. There was a progressive increase in tree richness and all tree structural traits from early to late stages, as well as marked changes in tree species composition and dominance. This pattern is probably related to pasture management practices such as ploughing, which remove tree roots and preclude regeneration by resprouting. On the other hand, liana density decreased from intermediate to late stages, showing a negative correlation with tree density. The higher liana abundance in intermediate stage is probably due to a balanced availability of support and light availability, since these variables may show opposite trends during forest growth. Predicted succession models may represent extremes in a continuum of possible successional pathways strongly influenced by land use history, climate, soil type, and by the outcomes of tree–liana interactions

Primary Congenital Glaucoma: A Novel Single-Nucleotide Deletion and Varying Phenotypic Expression for the 1546-1555dup Mutation in the GLC3A (CYP1B1) Gene in 2 Families of Different Ethnic Origin

Artículo científico -- Universidad de Costa Rica, Instituto de Investigaciones en Salud. 2003. Este documento es privado debido a limitaciones de derechos de autor.Purpose: To present new molecular genetic data on primary congenital glaucoma from 2 families, 1 isolated case and 3 familial cases due to mutations in the cytochrome P-450 1B1 (CYP1B1) gene. Methods: All diagnoses were made by slit-lamp biomicroscopy, gonioscopy, cornea and optic disk measurements, ultrasound-biometry, and automated static threshold perimetry where possible. Mutation screening was performed by direct sequence analysis of DNA extracted from peripheral blood of the patients and their relatives. Results: For the isolated case, a child of 4 years, a homozygous nucleotide deletion within a tetrad of cytosines (nt622–625, 622delC) was found leading to a predicted nonsense codon 93 truncating the protein by 450 amino acids. For the familial cases, the 3 affected members showed a homozygous mutation 1546–1555dupTCATGCCACC for which 9 healthy relatives proved to be heterozygous. The phenotypic expression of these 3 patients varied widely. Conclusion: Our results confirm the crucial role of CYP1B1 mutations for congenital glaucoma.Universidad de Costa Rica. Instituto de Investigaciones en SaludUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Proyecto de Desarrollo Rural de la Comunidad de los Ángeles. Asentamiento Maryland

Este documento presenta un diagnóstico participativo y una propuesta de desarrollo rural para la comunidad de los Ángeles, Asentamiento Maryland que tuvo como objetivo el de conocer la realidad agrosocieconómica de un grupo de agricultores parceleros ubicados en la comunidad

Epithelial WNT Ligands Are Essential Drivers of Intestinal Stem Cell Activation

Intestinal stem cells (ISCs) maintain and repair the intestinal epithelium. While regeneration after ISC-targeted damage is increasingly understood, injury-repair mechanisms that direct regeneration following injuries to differentiated cells remain uncharacterized. The enteric pathogen, rotavirus, infects and damages differentiated cells while sparing all ISC populations, thus allowing the unique examination of the response of intact ISC compartments during injury-repair. Upon rotavirus infection in mice, ISC compartments robustly expand and proliferating cells rapidly migrate. Infection results specifically in stimulation of the active crypt-based columnar ISCs, but not alternative reserve ISC populations, as is observed after ISC-targeted damage. Conditional ablation of epithelial WNT secretion diminishes crypt expansion and ISC activation, demonstrating a previously unknown function of epithelial-secreted WNT during injury-repair. These findings indicate a hierarchical preference of crypt-based columnar cells (CBCs) over other potential ISC populations during epithelial restitution and the importance of epithelial-derived signals in regulating ISC behavior

Novel Mutations in the MYOC/GLC1A Gene in a Large Group of Glaucoma Patients

Artículo científico -- Universidad de Costa Rica. Instituto de Investigaciones en Salud, 2002. Por políticas de la revista en la que el artículo fue publicado no es posible descargar la versión del editor/PDF; no obstante, se pone a disposición el enlace de la publicación original.Mutations at the myocflin (MYOC) gene within the GLC1A locus have been revealed in 2- 4% of patients suffering primary open angle glaucoma (POAG) worldwide. In our ongoing glaucoma study sixhundred eighty two persons have been screend for MYOC mutations. The first group consisted of 453 patients from a long-term clinical study diagnosed either with juvenile OAG (JOAG), POAG, ocular hypertension (OHT) or normal tension glaucoma (NTG) plus 22 cases of secondary glaucoma. This group, and additional 83 healthy controls, is part of a long term study with repeated clinical examinations at the University of Erlangen-Nurnberg. An additional sample of 124 glaucoma patients or at risk persons referred from other sources were included in the mutation screening. Five novel mutations, namely Gly434Ser, Asn450Asp, Va1251Ala, 11e345Met and Ser393Asn, could he identified as cause of preperimetrk POAG, JOAG, normal tension POAG and POAG. Myocilln mutations were identified similar with previous reports with other ethnic populations at the rate of 11/341 (3.2%) probandsUniversidad de Costa Rica. Instituto de Investigaciones en SaludUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA