W269 Weed Control in Centipedegrass

Turfgrass Science factsheet Version 3.

W269 Weed Control in Centipedegrass

Turfgrass Science factshee

W269 Weed Control in Centipedegrass

Turfgrass Science factsheet Version 3.

Comparative Approaches to Studying Strategy: Towards an Evolutionary Account of Primate Decision Making

How do primates, humans included, deal with novel problems that arise in interactions with other group members? Despite much research regarding how animals and humans solve social problems, few studies have utilized comparable procedures, outcomes, or measures across different species. Thus, it is difficult to piece together the evolution of decision making, including the roots from which human economic decision making emerged. Recently, a comparative body of decision making research has emerged, relying largely on the methodology of experimental economics in order to address these questions in a cross-species fashion. Experimental economics is an ideal method of inquiry for this approach. It is a well-developed method for distilling complex decision making involving multiple conspecifics whose decisions are contingent upon one another into a series of simple decision choices. This allows these decisions to be compared across species and contexts. In particular, our group has used this approach to investigate coordination in New World monkeys, Old World monkeys, and great apes (including humans), using identical methods. We find that in some cases there are remarkable continuities of outcome, as when some pairs in all species solved a coordination game, the Assurance game. On the other hand, we also find that these similarities in outcomes are likely driven by differences in underlying cognitive mechanisms. New World monkeys required exogenous information about their partners’ choices in order to solve the task, indicating that they were using a matching strategy. Old World monkeys, on the other hand, solved the task without exogenous cues, leading to investigations into what mechanisms may be underpinning their responses (e.g., reward maximization, strategy formation, etc.). Great apes showed a strong experience effect, with cognitively enriched apes following what appears to be a strategy. Finally, humans were able to solve the task with or without exogenous cues. However, when given the chance to do so, they incorporated an additional mechanism unavailable to the other primates - language - to coordinate outcomes with their partner. We discuss how these results inform not only comparative psychology, but also evolutionary psychology, as they provide an understanding of the evolution of human economic behavior, and the evolution of decision making more broadly

Homocysteine Metabolism in ZDF (Type 2) Diabetic Rats

Mild hyperhomocysteinemia is a risk factor for many diseases, including cardiovascular disease. We determined the effects of insulin resistance and of type 2 diabetes on homocysteine (Hcy) metabolism using Zucker diabetic fatty rats (ZDF/Gmi fa/fa and ZDF/Gmi fa/?). Plasma total Hcy was reduced in ZDF fa/fa rats by 24% in the pre-diabetic insulin-resistant stage, while in the frank diabetic stage there was a 59% reduction. Hepatic activities of several enzymes that play a role in the removal of Hcy: cystathionine β-synthase (CBS), cystathionine γ-lyase, and betaine:Hcy methyltransferase (BHMT) were increased as was methionine adenosyltransferase. CBS and BHMT mRNA levels and the hepatic level of S-adenosylmethionine were also increased in the ZDF fa/fa rats. Studies with primary hepatocytes showed that Hcy export and the transsulfuration flux in cells from ZDF fa/fa rats were particularly sensitive to betaine. Interestingly, liver betaine concentration was found to be significantly lower in the ZDf fa/fa rats at both 5 and 11 weeks. These results emphasize the importance of betaine metabolism in determining plasma Hcy levels in type 2 diabetes