Costa A.R.,University of Evora |
Costa A.R.,Institute of Mediterranean Agricultural science ICAM |
Real J.,Center for Neuroscience and Cell Biology |
Antunes C.M.,University of Evora |
And 3 more authors.
In Vitro Cellular and Developmental Biology - Animal
It has been postulated that a decrease in Na,K-ATPase-mediated ion gradients may be a contributing mechanism to insulin secretion. However, the precise role of the Na,K-ATPase in pancreatic β-cell membrane depolarization and insulin secretion signalling have been difficult to evaluate, mostly because data reporting changes in enzymatic activity have been obtained in cell homogenates or membrane preparations, lacking intact intracellular signalling pathways. The aim of this work was to develop a method to characterize Na,K-ATPase activity in intact pancreatic β-cells that will allow the investigation of putative Na,K-ATPase activity regulation by glucose and its possible role in insulin secretion signalling. This work demonstrates for the first time that it is possible to determine Na,K-ATPase activity in intact pancreatic β-cells and that this is a suitable method for the study of the mechanisms involved in the Na,K-ATPase regulation and eventually its relevance for insulin secretion signalling. © 2009 The Society for In Vitro Biology. Source
Calado J.M.G.,University of Evora |
Calado J.M.G.,Institute of Mediterranean Agricultural science ICAM |
Basch G.,University of Evora |
Basch G.,Institute of Mediterranean Agricultural science ICAM |
And 2 more authors.
In general, effective weed control in no-tillage systems is based on the use of herbicides. However, the development of appropriate weed management strategies can help to reduce the amount of herbicides applied. In this study weed management in common wheat under no-till was analyzed. The experiment was carried out under Mediterranean conditions on a Luvisol, during two growing seasons (1996/1997 and 1999/2000). A split-plot design with four replications was used. The main plot was weed emergence before wheat sowing (with and without weed emergence) and the subplot was the post-emergence weed control (with and without post-emergence herbicide). The density of the weeds was significantly reduced when the wheat crop was sown after a considerable part of the weeds had emerged and controlled by a pre-sowing herbicide (non-selective, systemic and non-persistent). Without weed control in post-emergence treated plots, the number of grains and the yield was increased significantly, compared to sowing without weed emergence. It can be concluded that under Mediterranean conditions, it is possible to reduce or even avoid the application of post-emergence herbicides in wheat under no-till, as weeds can be efficiently controlled before sowing. © 2009 Elsevier Ltd. All rights reserved. Source