O efeito de borda influencia a estrutura da comunidade vegetal em uma floresta tropical seca?

Efeitos de borda são considerados fator-chave na regulação da estrutura de comunidades vegetais em diferentes ecossistemas. Entretanto, apesar dos poucos estudos relacionados, o efeito de borda parece não ser determinante em regiões semiáridas, como a floresta tropical seca brasileira, conhecida como Caatinga. Este estudo testou a hipótese nula de que a comunidade vegetal arbustivo-arbórea não sofre alterações em sua estrutura, riqueza e composição devido ao efeito de borda. Foram instaladas 24 parcelas (20 x 20 m) em um fragmento de Caatinga arbórea, sendo 12 parcelas na borda do fragmento e 12 parcelas no seu interior. A riqueza, abundância e composição das espécies não diferiram estatisticamente entre as parcelas de borda e interior. Os resultados deste estudo corroboram um possível padrão de ambientes semiáridos e contrastam com resultados anteriores de diferentes ambientes, como florestas tropicais úmidas, cerrado e floresta de araucária. Indicam diferenças abruptas entre comunidades vegetais da borda e do interior de fragmentos florestais, sugerindo que a comunidade arbustivo-arbórea da Caatinga não é ecologicamente afetada pela presença de bordas._________________________________________________________________________________________ ABSTRACT: Edge effects are considered a key factor in regulating the structure of plant communities in different ecosystems. However, regardless to few studies, edge influence does not seem to be decisive in semiarid regions such as the Brazilian tropical dry forest known as Caatinga but this issue remains inconclusive. The present study tests the null hypothesis that the plant community of shrubs and trees does not change in its structure due to edge effects. Twenty-four plots (20 x 20 m) were set up in a fragment of Caatinga, in which 12 plots were in the forest edges and 12 plots were inside the fragment. Tree richness, abundance and species composition did not differ between edge and interior plots. The results of this study are in agreement with the pattern previously found for semiarid environments and contrasts with previous results obtained in different environments such as Rainforests, Savanna and Forest of Araucaria, which indicate abrupt differences between the border and interior of the plant communities in these ecosystems, and suggest that the community of woody plants of the Caatinga is not ecologically affected by the presence of edges

Chemical and biological additives in high moisture triticale silages: Nutritional value and ingestive behavior in sheep

El ensilaje de triticale de grano con alto contenido de humedad es una excelente opción para las dietas de rumiantes. Sin embargo, falta información sobre el control de pérdidas durante el proceso de fermentación. Se hizo una evaluación sobre los efectos de los aditivos químicos y biológicos a ensilajes de triticale de alta humedad en la composición química-bromatológica, la estabilidad aeróbica, la digestibilidad in vivo y el comportamiento de ingesta en ovinos. Se evaluaron cuatro tratamientos: ensilaje de triticale sin aditivo (control); ensilaje con un inoculante enzimático-bacteriano; ensilaje con 0.5% de urea en materia natural; y ensilaje con benzoato de sodio al 1.5% en materia natural. El comportamiento de ingesta se evaluó con cuatro ovejas macho en jaulas metabólicas. La adición de urea como aditivo proporcionó un aumento en el contenido de la proteína cruda (189.7 g kg MS-1) y el nitrógeno amoniacal (106.2 g kg MS-1), pero no afectó la digestibilidad (699.6 g kg MS-1 en tratamiento con urea, promedio = 687.5 g kg MS-1) ni el comportamiento de ingesta. El consumo de fibra aumentó con la adición del aditivo enzimático-bacteriano (431.87 vs 388.06 g d-1 fibra detergente neutra en el control). Todos los aditivos ayudaron a preservar el contenido de proteína cruda después de la apertura del silo, pero ninguno interfirió en el tiempo de estabilidad aeróbica del ensilado.Triticale high moisture grain triticale silage is an excellent option for ruminant diets, but loss control during its fermentation process should be further investigated. Thus, the objective of this study was to evaluate the effects of chemical and biological additives on high moisture triticale silages under chemical-bromatological composition, aerobic stability, and in vivo digestibility and ingestive behavior in sheep. The treatments were: high moisture triticale silage without additive (HMTC); high moisture triticale silage with enzyme-bacterial inoculant (HMTEB); high moisture triticale silage with 0.5 % urea in natural matter (HMTU); and high moisture triticale silage with 1.5 % sodium benzoate in natural matter (HMTSB). Four sheep were housed in appropriate metabolic cages according to the ethical principles of animal experimentation. The addition of urea as additive to high moisture triticale silage provided an increase in crude protein and ammoniacal silage (189.7 and 106.2 g kg MS-1, respectively) but did not affect digestibility (699.6 g kg MS-1 for HMTU, with a general average of treatments of 687.5 g kg MS-1) and ingestive behavior of sheep. Fiber consumption by sheep increased with the addition of the enzyme-bacterial additive in the silage (431.87 versus 388.06 g d-1 of FDN for HMTEB and HMTC, respectively). All additives helped to preserve crude protein contents after silo opening, but none interfered in aerobic stability time of silage

Papain-cyclodextrin complexes as an intestinal permeation enhancer: Permeability and in vitro safety evaluation

Oral drug delivery is the main route for drugs administration. However, some drugs have poor permeability across the intestinal barrier. Papain has been widely used in pharmaceutical applications due to its debridement properties and the ability to promote skin permeation of drugs. It is known that papain complexation with cyclodextrins improves its biological stability. In this paper, the ability of the native papain-cyclodextrin complexes is shown be an oral permeation enhancer to furosemide, using a Caco-2 monolayer system to evaluate drug permeability and apparent permeability coefficient. Analysis of the in vitro cytotoxicity over CHO–K1, Hep G2 and Caco-2 cell lines and genotoxicity over CHO–K1 and Hep G2 cell lines were also performed. Papain-cyclodextrins complexes did not show any cytotoxicity above 31 μg/mL. No significant genotoxic damage was observed. Papain and cyclodextrin complexes induced almost 2.5-fold increase in furosemide permeation compared to controls, and maintenance of the paracellular integrity of the Caco-2 cells monolayer was confirmed. The papain complexes may be safely applied in pharmaceutical formulations, not only as a therapeutic agent but also as a strategic pharmaceutical adjuvant, promoting permeation of low oral permeability drugs