4 research outputs found

    Winter Movements of Louisiana Pine Snakes (Pituophis ruthveni) in Texas and Louisiana

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    Despite concerns that the Louisiana Pine Snake (Pituophis ruthveni) has been extirpated from large portions of its historic range, only a limited number of studies on their movement patterns have been published. Winter movement patterns are of particular interest since it has been hypothesized that impacts of management practices would be reduced during the winter. Using radiotelemetry, we determined winter movement patterns of Louisiana Pine Snakes (11 males, 8 females) in 5 study areas (2 in Louisiana and 3 in Texas). Movements during winter (November–February) were greatly curtailed compared to the remainder of the year; however, snakes occasionally undertook substantial movements. Relocations were typically within the snake’s previous active-season home range, and movements were more frequent in the early portion of winter. All hibernation sites were within Baird’s Pocket Gopher (Geomys breviceps) burrow systems at depths ranging from 13–25 cm. Louisiana Pine Snakes did not use communal hibernacula, nor did individual snakes return to previously used sites in successive years

    Prey handling and diet of Louisiana pine snakes (Pituophis ruthveni) and black pine snakes (P. melanoleucus lodingi), with comparisons to other selected colubrid snakes

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    Diet and prey handling behavior were determined for Louisiana pine snakes (Pituophis ruthveni) and black pine snakes (P. melanoleucus lodingi). Louisiana pine snakes prey heavily on Baird\u27s pocket gophers (Geomys breviceps), with which they are sympatric, and exhibit specialized behaviors that facilitate handling this prey species within the confines of burrow systems. Black pine snakes, which are not sympatric with pocket gophers, did not exhibit these specialized behaviors. For comparative purposes, prey handling of P. sayi sayi and Elaphe obsoleta lindheimeri was also examined

    Biochemical and pharmacological role of A1adenosine receptors and their modulation as novel therapeutic strategy

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    Adenosine, the purine nucleoside, mediates its effects through activation of four G-protein coupled adenosine receptors (ARs) named as A1, A2A, A2Band A3. In particular, A1ARs are distributed through the body, primarily inhibitory in the regulation of adenylyl cyclase activity and able to reduce the cyclic AMP levels. Considerable advances have been made in the pharmacological and molecular characterization of A1ARs, which had been proposed as targets for the discovery and drug design of antagonists, agonists and allosteric enhancers. Several lines of evidence indicate that adenosine interacting with A1ARs may be an endogenous protective agent in the human body since it prevents the damage caused by various pathological conditions, such as in ischemia/hypoxia, epileptic seizures, excitotoxic neuronal injury and cardiac arrhythmias in cardiovascular system. It has also been reported that one of the most promising targets for the development of new anxiolytic drugs could be A1ARs, and that their activation may reduce pain signaling in the spinal cord. A1AR antagonists induce diuresis and natriuresis in various experimental models, mediating the inhibition of A1ARs in the proximal tubule which is primarily responsible for reabsorption and fluid uptake. In addition, the results of various studies indicate that adenosine is present within pancreatic islets and is implicated through A1ARs in the regulation of insulin secretion and in glucose concentrations. In the present paper it will become apparent that A1ARs could be implicated in the pharmacological treatment of several pathologies with an important influence on human health

    Chemical Composition of Icy Satellite Surfaces

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