Testing predictions of foraging theory for a sit-and-wait forager, Anolis gingivinus

Research in foraging theory has been dominated by studies ofactive foragers choosing among patches and among prey withina patch. Studies of central-place foraging have mainly focusedon loading decisions of an animal provisioning a central place.The problem faced by a sit-and-wait forager that encountersprey at a distance has received little attention. In this studywe tested foraging theory predictions for such foragers, Anolisgingivinus females in the West Indies island of Anguilla. Wepresented lizards with antlion larvae at various distances.Experiment 1 showed that an individual's probability of pursuingprey decreases with the prey's distance and is best describedby a sigmoidal function (which may be as steep as a step function).This function's inflection point defines a cutoff distance.Experiment 3 tested how cutoff distance changes as a functionof prey size. Cutoff distances were greater for larger prey,as predicted for an energy-maximizing forager. Experiments 2and 4 tested how cutoff distance changes as a function of preyabundance. As predicted, cutoff distance were greater at a sitewhere prey abundance was lower. Furthermore, cutoff distancesdecreased immediately following prey augmentation and returnedto previous values within one day of ending augmentation. Thus,moles' foraging behavior is a dynamic process, consistent withthe qualitative predictions of foraging theory. We attributethe success of this study in supporting fundamental foragingtheory predictions to the lizards exhibiting natural behaviorunder field conditions and to particular advantages of studyingsit-and-wait foragers.     

Proposed follow up programme after curative resection for lower third oesophageal cancer

Cyclins are indispensable elements of the cell cycle and derangement of their function can lead to cancer formation. Recent studies have also revealed more mechanisms through which cyclins can express their oncogenic potential. This review focuses on the aberrant expression of G1/S cyclins and especially cyclin D and cyclin E; the pathways through which they lead to tumour formation and their involvement in different types of cancer. These elements indicate the mechanisms that could act as targets for cancer therapy.