Heat stress (HS) increases the death of intestinal cells in pigs, which, in turn, may elevate the endogenous intestinal loss (EIL) of proteins and AA. An experiment was conducted to analyze the effect of HS on the AA composition of intestinal endogenous proteins and the EIL of AA in pigs. Eight pigs (25.2 ± 1.2 kg initial BW) were surgically implanted with T-type cannulas at the end of the small intestine. After surgery recovery, during the subsequent 7 d, all pigs were adapted to a protein- and AA-free diet and trained to consume the same amount of feed twice a day. All pigs were housed under thermoneutral (TN) conditions (22 ± 2°C) during this time. The following day, all pigs were still under TN conditions and ileal content was collected during 12 consecutive hours, at the end of which and for the following 8 d the pigs were exposed to natural HS conditions (31 to 37°C). Ileal content was collected again on d 2 (HS at d 2 [HSd2]) and 8 (HS at d 8 [HSd8]). Body temperature (BT) was measured in another group of 8 pigs every 15 min during the whole study. The average BT at HSd2 (39.6°C) was higher ( < 0.05) compared with both TN conditions (38.6°C) and HSd8 (38.8°C), but it did not differ between TN conditions and HSd8. The AA composition of endogenous intestinal protein was not affected by HS. The EIL of Arg and His were greater ( < 0.05) and the EIL of Thr and Phe tended to be greater ( ≤ 0.10) at HSd2 than in TN conditions; the EIL of Pro was greater ( = 0.01) at HSd8. The EIL of the remaining AA was not affected by HS. Although HS increased the EIL of Arg and His within the first 2 d, it appeared that normal EIL was shortly reestablished. These data show that acute HS does not affect the AA composition of intestinal endogenous proteins in growing pigs and that the EIL of AA may not be critical in growing pigs acclimated to high ambient temperature. Nevertheless, the increased EIL of Arg and Thr at HSd2 indicate that HS might affect the integrity of the intestinal epithelium of pigs during the first day of their exposure to high ambient temperature.

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Forty-one isolates obtained from apple fruit exhibiting the typical symptoms of bitter rot in Uruguay were characterized based on molecular, phenotypic and pathogenicity data. Four species were identified based on the analysis of ITS, GAPDH and BTUB2 genes. The dominant species was Colletotrichum fructicola (33/41 isolates) followed by C. theobromicola (6/41 isolates), both belonging to the C. gloeosporioides species complex. The other species, with one isolate each, were C. melonis and Colletotrichum sp. both belonging to the C. acutatum species complex. Surprisingly, C. gloeosporioides and C. acutatum, commonly reported as the cause of bitter rot, were not found. Phenotypical traits were useful to assign the isolates to a species complex, but not to identify phylogenetic species. Isolates of all four species were able to cause the typical bitter rot disease, but the two species of the C. gloeosporioides species complex were the most aggressive based on lesion size.

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Este documento tiene como objetivo destacar la función que realizan los directores y equipos directivos de instituciones educativas de nivel medio superior en el plano específico de la gestión del clima organizacional y la convivencia con los diferentes actores que coinciden en la escuela. Para ello, se han tomado en cuenta las apreciaciones valorativas delos profesores de dichos centros educativos en torno al desempeño de sus directivos. La metodología empleada se sustentó en la investigación cualitativa, pues se procuró recabar información sobre el tema de estudio a través de un cuestionario y unas escalas de tipo Likert. Los principales resultados indican que el profesorado está en desacuerdo con la manera en que sus directivos ejercen su liderazgo y los trabajos de gestión institucional, lo que se vincula con negativos resultados de aprendizaje en los estudiantes. En conclusión, se considera importante que los directivos impulsen el trabajo colaborativo y la comunicación dinámica y abierta en las instituciones de educación media superior para resolver sus problemascontextuales más apremiantes.