175,630 research outputs found
D. Antonii Mazza Historiarum epitome
No full textCors. ; rom.[10], 160, [16] p., 1 c. di tav. : antip. calcogr.Segn.: a⁶ A-Y⁴Antip. calcogr. disegnata da Francesco Solimena e incisa da Jacques BlondeauOcchietto: D. Antonii Mazza Historiarum epitomeIniz. e fregi xil
«Se per amore i morti rinascessero»: Enzo Mazza, un (grande) poeta in ombra
No full textIllustrazione della produzione di Enzo Mazza e focalizzazione della sua poetica: principali linee tematiche, principali stilemi
Neurotensin as Modulator of Glutamatergic Signalling: Relevance in Neurodegenerative Diseases
No full textRationale: Neurotensin (NT) is a tridecapeptide widely distributed in mammalian brain, where acts as a neurotransmitter or neuromodulator of classical neurotransmitters, mainly through the activation of its receptor NTS1. Several in vitro and in vivo studies have demonstrated the existence of close interactions between NT and dopamine (DA) systems both in limbic and striatal brain regions (Nemeroff CB., 1985; Binder EB., 2001; Caceda R., 2006). Because of the involvement of an over-activation of DA system in the development of neurological disorders such as schizophrenia, psychosis and dyskinesia, a strong attention was given to the study of complex interactions between NTS1 and D2 dopamine receptor, highlighting the existence of receptor-receptor interaction, potential target for developing new anti-schizophrenic drugs (Ferraro L., 2007). In addition, neurochemical and biochemical data indicate that NT plays a crucial role in regulating glutamatergic transmission, probably inducing an amplification of NMDA receptor signalling, even at threshold concentrations (lOnM) (Antonelli T., 2004).
Results I: The neuromodulatory function of NT on glutamatergic signalling was studied in an in vitro model of primary cortical cultures, highlighting a dose-dependent effect (NT 0.1-300 nM) on glutamate release. In addition, NT show the ability to amplify the NMDA-induced (lOOnM) increase of glutamate release. The use of the NTS1 receptor antagonists, SR48692 (lOOnM) and the NMDA receptor antagonist MK-801 (l[iM), in combination with an effective concentration of NT, made possible to hypothesize that the mechanism involved could be an NTSl/NMDA receptor-receptor interaction (Antonelli T., 2004; Ferraro L., 2008) both at striatal and cortical level. It has been postulated that the accumulation of extracellular glutamate level and the consequent excessive activation of NMDA receptors (excitotoxic mechanism) contributes to neuronal death associated with chronic and acute neurodegenerative diseases (Olney JW., 1978). Since the data obtained to date suggest a NT-mediated strengthening on several glutamatergic functions in the central nervous system, our work was intended to deepen its possible involvement in glutamate-induced neurodegenerative mechanisms. The in vitro model of cerebral ischemia obtained by oxygen and glucose deprivation (OGD) showed a significant increase in extracellular levels of glutamate. In addition, significant alterations of biochemical and morphological parameters measured were observed. Increase the release of LDH, reduction of mitochondrial oxidative capacity (MTT levels), increased activity of caspase-3, increased number of apoptotic (fragmented) nuclei, increasead level of AN(+)/PI(-) immunoreactive cells and MAP-2 dendritic aggregations was measured 24 hours after the ischemic insult. The addition of NT (lOOnM) to the culture medium showed a significant increase in the OGD-induced changes, while cells pre-exposure to the NTS1 antagonist SR48692 (lOOnM) blocked the effect of both the neuropeptide and OGD exposure, alone or in combination. The results obtained with this in vitro model of cerebral ischemia, stress the involvement of NT activity in the eziopathogenesis of an acute neurodegenerative disease (Antonelli T., 2008).
Results II: At basal ganglia level, NT induces an amplification of glutamate release, probably through a NTS1/D2 antagonistic interaction. This phenomenon could contribute to the degeneration of dopaminergic nigro-striatal neurons by the means of an excitotoxic mechanism, pathogenetic feature of Parkinson's disease (PD). In this contex, experiments were conducted with the in vivo microdialysis technique at striatal and cortical level, anatomical areas notoriously involved in PD. The results obtained again showed that a, potential, NTS1/NMDA receptor-receptor interaction induces a glutamatergic signalling amplification. The observed increase in glutamate extracellular levels induced by treatment with NMDA (100 and 500 uM) and NT (lO nM), showed once again to be partially blocked by treatment with NT antagonist SR48692 (Ferraro L., 2008). Given the potential neuroprotective role played SR48692, successive studies in an vivo model of PD achieved through unilateral lesion of the nigro-striatalpathway with the neurotoxin 6-idroxydopamine (6-OHDA) were done. Three experimental groups were tested for the turning rotation behaviour and by a challenge with NMDA lOOuM: lesioned rats, rats exposed only to vehicle and lesioned rats treated with the neurotensinergic antagonist. The animals exposed to SR48692 have shown a significant recovery for both the parameter of turning behaviour and responsiveness to pharmacological challenge with NMDA (Ferraro L., 2008). The results obtained can lead to the hypothesis that the use of selective NTS1 receptor antagonists, in combination with conventional drug treatments, could provide a new terapeutic approach for chronic and acute neurodegenerative diseases treatment, such as cerebral ischemia and Parkinson's disease
European Universities in Transition: Issues, Models and Cases
No full text'This attractively presented edited collection is a welcome analysis of issues facing universities. It consists of 14 chapters by experts who work in university management and economics' departments... this is an excellent collection. Its value stems from the fact that it enables comparisons to be made and to see that globally the traditional university system is being seriously challenged. The authors in this collection provide a range of perspectives on how the universities in their various locations can begin to respond to these challenges.' © Carmelo Mazza, Paolo Quattrone and Angelo Riccaboni, 2008. All rights reserved
Valutazione e localizzazione della criticità della risorsa idrica (dominio vulcanico laziale)
No full textLa disponibilità delle risorse idriche sotterranee nel dominio vulcanico laziale, è stata definita attraverso l’analisi del bilancio idrogeologico distribuito, la valutazione dell’entità dei prelievi per gli usi idropotabili, agricoli ed industriali e da considerazioni relative alle portate emergenti e ai deflussi sotterranei naturali. Gli elementi che sono stati presi in considerazione per la valutazione delle risorse disponibili sono: a) l’ambito territoriale di riferimento; b) i valori e la ciclicità della ricarica (risorse rinnovabili); c) i volumi idrici prelevati per diversi usi; d) i deflussi superficiali e sotterranei da mantenere nei diversi settori del sistema acquifero. Scendendo ancora di scala, all’interno dei bacini idrogeologici, risulta utile individuare le “aree critiche”, ovvero quei settori del corpo idrico sotterraneo in cui la concentrazione dei prelievi determina livelli di alterazione della circolazione idrica e dei livelli piezometrici significativamente superiori a quelli delle aree circostanti con rischio di compromissione in tempi brevi dell’approvvigionamento idrico delle attività che vi insistono. La criticità viene valutata tenendo conto delle caratteristiche fisiche dell’acquifero, delle evidenze di depauperamento della risorsa e delle differenti entità e destinazioni d’uso dei prelievi. Le aree critiche vengono definite in maniera oggettiva mediante una procedura di indicizzazione dei diversi fattori (7 indici), secondo una matrice di valutazione. Sono inoltre indicate come “aree di attenzione” quelle aree in cui viene evidenziata una criticità legata essenzialmente ad anomalie piezometriche, ma sulle quali il prelievo calcolato non risulta particolarmente elevato, comunque paragonabile ai valori medi riscontrati sull’acquifero (prelievo totale minore di 1.600 m3/anno/ha).The availability of groundwater resources in the volcanic domain of Latium region, has been defined taking into consideration: the distributed hydrological budget, the entity of the withdrawals for drinking industrial and agricultural water uses, and the discarge of the springs and of the basic flow of main rivers. The elements that have been taken into account to evaluate the resources are: a) the territorial reference, b)the amount of infiltration and its variability (renewable resources), c) the amount of withdrawals d ) the minimum discarge of surface water and groundwater of the aquifer system. Within the hydrological basins, it is useful to identify the "critical areas", which are areas of the aquifer in which the concentration of the samples has determined anomalies of water surface and of piezometric levels, these areas are those at risk of water supply. Critical areas are defined by a matrix calculation which considers different factors (7 ratios). The “attention areas” are defined like areas in which the criticality refers to the piezometric anomalies, but on which the withdrawal is not particularly high, similar to the average withdrawal of aquifer (total levy less than 1,600 m3 / year / ha)
On the storage capacity of nonlinear neural networks
No full textMazza, C.. (1994). On the storage capacity of nonlinear neural networks. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/2673
Possible influence of the δ13C variations on the Carnian/Norian conodonts diffusion.
No full textQuantitative analyses of the absolute abundances of the species belonging to the five most widespread Upper Carnian/Lower Norian conodont genera (Paragondolella, Carnepigondolella, Metapolygnathus, Epigondolella, and Norigondolella) from the Pizzo Mondello section (Monti Sicani, Western Sicily, Italy), GSSP candidate for the Norian stage (Balini et al., 2008), show potential ecological competition between these genera. Cross checks of the quantitative curves evidence the presence of three major assemblage changes, named T events: at T1 Carnepigondolella is replaced by its descendant Epigondolella in an evolutionary step; at T2 Epigondolella is substituted by the mass occurrence of Metapolygnathus and at T3 Metapolygnathus is succeeded by advanced Epigondolellae and by Norigondolella. A comparison between these quantitative curves and coeval δ18O and δ13C isotopic curves, obtained from the carbonate bulk of the section, shows a correspondence between higher13C/12C ratios and event T2 (and partially event T3), but not with T1. Thus, while the shifts in the C isotopic composition of seawater do not affect conodont evolution, they have an influence on the diffusion of the studied genera, which react differently to the δ13C variations. Epigondolella and Carnepigondolella proliferate in fact when seawater δ13C is lower than 2.5‰, Metapolygnathus is instead limited to environmental conditions related to δ13C values higher than 2.5‰ (Mazza et al., 2009). The rapid expansion of photosynthetically active organisms in the Upper Carnian may explain these perturbations in the carbon cycle and have influenced the trophic chain of the different conodont animal genera, producing thus mutual local migrations
Biextensions of 1-motives in Voevodsky's category of motives
No full textLet k be a perfect field. In this paper we prove that biextensions of 1-motives define multilinear morphisms between 1-motives in Voevodsky’s triangulated category DMeff
gm(k,Q) of effective geometrical motives over k with rational coefficients
"Mazza, Damiano"
No full textDamiano Mazza (Venice, c. 1550 - 25 ag. 1576) was a Venetian painter actif in the second half of 16th centurie. He frequented Titian's circle, to which he was perhaps introduced by Orsatto Giustinian. His most significant paintings include the "Ascension of Christ" with Saints Felice and Fortunato for the high altar of the Noale parish's church (1573) and the "Coronation of the Virgin" for the Ospedaletto of S. Maria della Pietà (1575)
Revision of the conodonts of key Upper Triassic Tethyan sections: A step forward in definition of the Carnian/Norian boundary and new correlation options
No full textThe need to find a biomarker to define the Carnian¬Norian boundary resulted in appreciable revision of the taxonomy of the Upper Triassic P1 conodont elements in recent years. Pizzo Mondello (Sicily, Italy) is a GSSP candidate for the Norian and provides the most continuous and valuable conodont record for the Tethys: in 2004 seven species were recognized for the Upper Carnian-Lower Norian interval at Pizzo Mondello, whereas today 42 have been identified. Among these, seven new species are defined here. Since the Pizzo Mondello record could make it the world reference for Late Triassic conodont biostratigraphy, its correlation potential with other sections is fundamental. For this purpose, the conodont faunas of the Tethyan key sections Silická Brezová (Slovakia), Bölücektasi Tepe and Erenkolu Mezarlik (Turkey) were revised. This revision enabled recording the occurrence of newly established species in much of the Tethys. Species that are potentially useful for definition of the C/N boundary were discriminated in all these sections: Epigondolella quadrata Orchard, E. rigoi Noyan & Kozur, Carnepigondolella gulloae Mazza & Rigo and species of the Metapolygnathus communisti Hayashi group. The same succession of conodont bioevents were identified in all investigated sections, confirming that the Pizzo Mondello conodont record is representative for the entire Tethys. These results open the possibility of new correlation options throughout the Tethyan realm, solving some biostratigraphic discrepancies raised in past years, and laying the groundwork for discriminating a truly reliable biovent for definition of the C/-N boundary
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