1,721,131 research outputs found
Nitric oxide in follicle development and oocyte competence
Full text linkApart from its well-known role in regulating endothelial function, in mammals, nitric oxide (NO) is an important signaling molecule involved in many processes, regulating different biological functions. It has been demonstrated that NO plays a role in the physiology of the reproductive system, where it acts in controlling the activity of reproductive organs in both sexes. In the female of several animal species, experimental data suggest the presence of an intraovarian NO-generating system, which could be involved in the control of follicular development. The role of NO in regulating follicular atresia by apoptosis is still controversial, as a dual action depending mostly on its concentration has been documented. NO also displays positive effects on follicle development and selection related to angiogenic events and it could also play a modulatory role in steroidogenesis in ovarian cells. Both in monovulatory and poliovulatory species, the increase in PGE2 production induced by NO via a stimulatory effect on COX-2 activity appears to be a common ovulatory mechanism. Considerable evidence also exists to support an involvement of the NO/NO synthase system in the control of meiotic maturation of cumulus-oocyte complexes
L'Analisi e la Previsione delle Insolvenze: Lo Studio del Caso Italiano
No full textA causa delle conseguenze che il fenomeno comporta, sia sul piano finanziario sia sul fronte dell'economia reale, l'analisi e la previsione delle insolvenze societarie continua a rappresentare un argomento attuale nell'ambito della ricerca economica. I recenti sforzi condotti dal Comitato di Basilea verso la diffusione di criteri di valutazione del rischio di credito più precisi ed oggettivi, hanno ulteriormente accresciuto l'importanza della materia.
L'obiettivo del presente studio è l'analisi del fenomeno del fallimento sul territorio italiano, al fine di valutare quali variabili sono più efficaci nell'individuazione di una situazione di dissesto dell'impresa.
Per l'analisi si sono sviluppati dei modelli di previsione delle insolvenze in grado di individuare i segnali early warning di dissesto finanziario. L'analisi econometrica è basata su un campione ampio ed originale di fallimenti rilevati negli anni 2003 e 2004: a tal fine sono stati costituiti dei campioni comparabili di imprese fallite e non fallite ed è stato verificato, mediante l'applicazione di una metodologia logit, il potere previsivo di diversi indici di bilancio e di variabili di tipo non finanziario. I risultati ottenuti sono stati validati su un campione hold-out.
L'analisi si evidenzia l'importanza delle caratteristiche del settore di attività nel determinare la forma del processo di fallimento: i modelli sector specific ottengono risultati migliori rispetto ai modelli generali stimati. Inoltre, alcuni fattori comuni ai diversi settori di attività si dimostrano particolarmente efficaci nella previsione dei dissesti aziendali: l'età, il livello di leverage e la composizione del debito d'impresa, così come la sua redditività.Due to the consequences that the phenomenon entails both on the financial and real sides of the economy, the analysis and prediction of corporate failures continue to be a current topic in economic research. The recent efforts laid by the Basel Committee towards the diffusion of more precise and objective ways of assessing credit risk have further increased the importance of this matter.
The purpose of the study is to analyse the bankruptcy phenomenon among Italian firms, in order to assess what firm-specific and industry variables are more important in determining corporate failure events.
We develop a bankruptcy prediction model that aims at detecting early signals of financial distress. The econometric analysis is based on a wide and unique sample of recent failure events: comparable sets of bankrupt and non-bankrupt firms are identified and several prior balance-sheet and economic indicators are tested for their power in predicting failure probabilities in a logit modelling framework; model performances are cross-validated on hold-out samples.
The analyses provide evidence of the importance of industry membership in determining and shaping corporate failure processes: sector-specific models produce a better assessment of financial distress than general ones. Also, some common factors emerge as important predictors of corporate collapse across different industries: age, gearing and the composition of a firm's debt, as well as its capability of generating profits
Melatonin role in ovarian function
No full textMelatonin is a hormone mainly produced by the pineal gland in the absence of light stimuli. The light, in fact, hits the retina, which sends a signal to the suprachiasmatic nucleus which inhibits the synthesis of the hormone by the epiphysis. Mostly by interacting with MT1/MT2 membrane receptors, melatonin performs various physiological actions, among which the regulation of the sleep-wake cycle and the control of the immune system. One of its best known functions is the non-enzymatic antioxidant action, which is independent from binding with receptors and occurs by electron donation. The hormone also represents an indicator of the photoperiod in seasonally reproducing mammals, which are divided into long days and short days breeders according to the time of year in which they are sexually active and fertile. It is known that melatonin acts at hy-pothalamic pituitary gonadal axis level in many species. In particular, it inhibits the hypothalamic release of GnRH with consequent alteration of FSH and LH levels. Present paper is mainly ad-dressed to review the ovarian effect of melatonin
Ethology and Veterinary Medicine
No full textThe Authors present a brief review of the historical background of contemporary
ethology and its applied branches, which may help in understanding which questions this area seeks to answer. it is argued that ethological concepts, together with
anatomy and physiology, give a comprehensive and complete picture of the biology of an animal. Finally, this review explains how ethology and animal protection
became examination subjects from academic year 1985/86 in the italian Veterinary
Medicine curriculum
Sanguinarine inhibits VEGF-induced endothelial cell growth in a three dimensional fibrin gel matrix.
No full textOvarian activity and PRL plasma levels in ewes subjected to an artificial photoperiod followed by melatonin treatment
No full textProfilo ematico della PRL ed attività ovarica in pecore e capre trattate con melatonina mediante impianti biodegradabili.
No full textEffects of gonadal steroids on tonic LH release and LHRH-induced LH release from bovine pituitary cells cultured in vitro.
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