Altitud del límite superior de bosque en el Eje Neovolcánico Mexicano, un referente climático de la alta montaña en México

The upper limit of continuous and discontinuous forest in mountains higher than 4000 meters above sea level in Mexico was identified. This study was based on the normalized difference vegetation index and by means of principal component analysis. For the first case, it was found that in each slope the forest limit reaches a different altitude; however, on average the continuous forest (timberline) ends at 4019 and the discontinuous forest (treeline) at 4072 masl. On the other hand, the statistical analysis made it possible to determine that precipitation, soil type and the rate of solar radiation at the surface level are the main factors that govern its altitude. Finally, it was found that the temperature regime found on this limit approximates the standard values of the intertropical zone.Se identificó el límite superior de bosque continuo y discontinuo en las montañas superiores a 4000 metros sobre el nivel del mar en México. El estudio se basó en el índice de vegetación de diferencia normalizada y mediante el análisis de componentes principales. Para el primer caso, se encontró que en cada vertiente el límite de bosque alcanza una altitud distinta; sin embargo, en promedio el bosque continuo culmina a 4019 y el discontinuo a 4072 msnm. Por su parte, el análisis estadístico permitió determinar que la precipitación, el tipo de suelo y la tasa de radiación solar a nivel de superficie son los principales factores que rigen su altitud. Finalmente se halló que el régimen de temperatura encontrado en esta frontera se aproxima a los valores estándares de la zona intertropical

Uso e Integración Curricular de las TICs en la Facultad de Ciencias Biológicas y Agropecuarias de la Universidad Veracruzana.

Documento del 3er. Foro de Investigación Educativ

Active Surveillance of Antimicrobial Resistance and Carbapenemase-Encoding Genes According to Sites of Care and Age Groups in Mexico: Results from the INVIFAR Network

We analyzed the antimicrobial resistance (AMR) data of 6519 clinical isolates of Escherichia coli (n = 3985), Klebsiella pneumoniae (n = 775), Acinetobacter baumannii (n = 163), Pseudomonas aeruginosa (n = 781), Enterococcus faecium (n = 124), and Staphylococcus aureus (n = 691) from 43 centers in Mexico. AMR assays were performed using commercial microdilution systems (37/43) and the disk diffusion susceptibility method (6/43). The presence of carbapenemase-encoding genes was assessed using PCR. Data from centers regarding site of care, patient age, and clinical specimen were collected. According to the site of care, the highest AMR was observed in E. coli, K. pneumoniae, and P. aeruginosa isolates from ICU patients. In contrast, in A. baumannii, higher AMR was observed in isolates from hospitalized non-ICU patients. According to age group, the highest AMR was observed in the ≥60 years age group for E. coli, E. faecium, and S. aureus, and in the 19–59 years age group for A. baumannii and P. aeruginosa. According to clinical specimen type, a higher AMR was observed in E. coli, K. pneumoniae, and P. aeruginosa isolates from blood specimens. The most frequently detected carbapenemase-encoding gene in E. coli was blaNDM (84%)