1,721,035 research outputs found
Il monitoraggio della Fauna. Progetto di Monitoraggio Ambientale della Tenuta di Castelporziano.
No full textRapporto 199
Metapleural glands in Crematogaster clariventris Mayr and C. depressa Latr. (Formicidae Myrmicinae).
No full textProblemi Attuali di Scienza e di Cultura
Ricerche Biologiche in Sierra Leone (parteIV
Dati sulla biologia di due specie di formiche mietitrici (Messor wasmanni e M.minor) nella Tenuta presidenziale di Castelporziano
No full textGlandole delle Ponerine e ricerche sulle glandole del gastro di Megaponera foetens (Fabr.) (Hymenoptera Formicidae).
No full textProblemi di Scienza e di Cultura. Sez.: Missioni ed Esplorazioni
Le glandole metatoraciche di Crematogaster striatula Emery (Hymenoptera Formicidae Myrmicinae).
No full text
Effects of corticosteroids on oxidative damage and circulating carotenoids in captive adult kestrels (Falco tinnunculus)
No full textBirds control body homeostasis through the secretion of corticosterone. This hormone is the end-product of the hypothalamic-pituitary-adrenal (HPA) axis response to stressors. High levels of corticosterone may be associated with low individual fitness and may affect balance between pro-oxidants and antioxidants. Given these points, chronic stress modulated by hormones could undermine individual fitness by increasing oxidative tissue damage. In this study, we administered corticosteroids by diet (20 mg/kg of diet) to captive adult kestrels (Falco tinnunculus) over a 14-day period to evaluate the effects of a simulated chronic stress modulated by corticosteroids. We found that dietary administration of corticosterone caused a 32% increase of reactive oxygen metabolites, but did not impair total serum antioxidant capacity, serum carotenoids or body mass. Oxidative stress had a 64% increase in treated birds compared to 30% in controls. The two groups did not differ in the total serum antioxidant capacity, which showed a significant decrease over the study period. In contrast, circulating carotenoids and body mass increased in both groups. These results suggest that stress hormones, such as corticosterone, may also act as modulators of oxidative stress in birds
Carotenoid availability does not limit the capability of nestling kestrels (Falco tinnunculus) to cope with oxidative stress
No full textIt is recognized that carotenoids are useful anti-oxidants in embryo and hatchling avian models. However, recent evidence suggests that the anti-oxidant role of carotenoids in nestling or adult birds may not be as important as previously thought. The aim of the present work was to investigate if supplemental carotenoids decreased the level of oxidative damage (by reactive oxygen metabolites, ROMs) and increased the serum anti-oxidant capacity (OXY) in nestling Eurasian kestrels Falco tinnunculus. Circulating carotenoids in supplemented nestlings increased about 1.5-fold compared to the control and pretreatment levels at the end of the supplementation period. There was no effect on ROMs, OXY or the level of oxidative stress (ratio between ROMs and OXY), however, or on body mass or body condition of nestlings. ROMs and OXY decreased with age, but this pattern varied across the nests. Our results show that (i) in general, younger nestlings actually have to cope with a high free radical production, and (ii) the ability of wild nestling kestrels to cope with oxidative stress is not affected by carotenoid availability
Fenologia, uso dell'habitat e riproduzione del Gheppio Falco tinnunculus nella Tenuta Presidenziale di Castelporziano (Italia centrale)
No full textnumero speciale, Falconiformes della Tenuta Presidenziale di Castelporzian
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