SUMMARY Thyroid hormones and their receptors in the ovaries are active regulators of reproductive function; both hyper-and hypo-thyroidism may result in estrous cycle disturbances. In addition, thyroid hormones elicit an extraordinary multiplicity of biochemical, cellular, and physiological responses, both in the simplest and the most complex organisms. On the other hand, glutamate, the main ex...

In this paper I address the general perception that agricultural activities are the principal threat to primate biodiversity in the tropics and argue that in Neotropical landscapes some agricultural practices may favor primate population persistence, and that this situation merits attention and investigation. To explore these issues, I examined three interrelated pressures upon tropical forests...

this research was conducted during 2009 at a regional scale in birjand and qaen counties, southern khorasan, as an attempt to develop a sustainability index (si) for quantifying the sustainability of saffron agroecosystem. the information of these agroecosystems, including socio-economic, agronomic and ecological indicators was collected using questionnaires and was subjected to statistical ana...

The presence of antibiotic drug residues, antibiotic resistant bacteria, and antibiotic resistance genes in agroecosystems has become a significant area of research in recent years and is a growing public health concern. While antibiotics are used in both human medicine and agricultural practices, the majority of their use occurs in animal production where historically they have been used for g...

Tropical highland regions are experiencing rapid climate change. In these regions the adaptation challenge is complicated by the fact that elevation contrasts and dissected topography produce diverse climatic conditions that are often accompanied by significant ecological and agricultural diversity within a relatively small region. Such is the case for the Choke Mountain watersheds, in the Blue...

Termites play important roles in organic matter decomposition, nutrient cycling, and soil structure in tropical rain forests. When forests are replaced by agriculture, termite species richness, abundance, and function often decline. We compared the termite assemblage of a primary forest site with that of a low plant diversity, palm-based agroforest (five plant species) and a high plant diversit...

Our knowledge of ecological interactions that bolster ecosystem function and productivity has broad applications to the management of agricultural systems. Studies suggest that the presence of generalist predators in agricultural landscapes leads to a decrease in the abundance of herbivorous pests, but our understanding of how these interactions vary across taxa and along gradients of managemen...