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Interazione Etanolo-Stress nel modello dell'isolamento sociale nei topi C57 BL/6 J. Valutazione elettrofisiologica degli effetti dell'assunzione volontaria di etanolo sulla funzione delle sinapsi inibitorie GABAergiche dell'ippocampo di topi isolati.
Get PDFLo stress è ritenuto un fattore rilevante per l’abuso e la dipendenza da alcol. Il modello di isolamento sociale nei roditori è un modello di stress cronico, col quale è possibile valutare l’interazione fra stress ed EtOH. In topi C57 BL/6 J isolati socialmente per 6 settimane, dal Post Natal Day (PND) 21, sono stati valutati mediante tecniche elettrofisiologiche gli effetti dell’EtOH, sulla funzione delle sinapsi inibitorie GABAergiche in diverse popolazioni neuronali dell’ippocampo e del giro dentato. In seguito all’ esposizione cronica di EtOH, tramite inalazione di vapori, è stata valutata la variazione delle correnti post sinaptiche inibitorie spontanee potenziale d’azione dipendenti (sIPSCs) in cellule granulari del giro dentato dell’ippocampo e in cellule piramidali del nucleo centrale dell’ amigdala di topi di controllo e di topi sottoposti a 45 giorni di isolamento sociale. Nei differenti gruppi sperimentali è stato studiato anche l’effetto dell’agonista parziale THIP sulla corrente tonica registrata nei neuroni granulari del giro dentato dell’ippocampo. L’inalazione di EtOH induce nell’ippocampo e nell’amigdala dei topi isolati un marcato aumento della frequenza degli eventi. Al fine di valutare se in condizioni stressanti vi sia un aumento del consumo di etanolo, abbiamo utilizzato il protocollo dell’isolamento sociale dei topi per 45 giorni durante i quali gli animali erano liberi di assumere EtOH per 2h al giorno. L’isolamento sociale determina un aumento del consumo di EtOH. La frequenza delle correnti anche in questo caso, risulta aumentata in ippocampo e amigdala. L’Aumento della corrente tonica indotto dal THIP, osservato nei topi isolati che bevono acqua, non è più apprezzabile nei topi isolati che consumano etanolo.
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Stress is considered a relevant factor for alcohol addiction. Social isolation in rodents is a model of chronic stress used to study the interaction between stress and alcohol. The effects of EtOH on GABAergic inibitory synaptic transmission in different neuronal population, have been studied in C57 BL/6 J mice, socially isolated for 6 weeks from Post Natal Day (PND) 21. Following chronic exposure to EtOH using inhalation chambers, spontaneous inhibitory postsynaptic currents (sIPSCs) were measured in hippocampal dentate gyrus granule cells (DGGC )and in pyramidal cell of the amygdala central nucleus in group housed and in socially isolated mice. We also studied the effect of THIP, a partial agonist of extrasynaptic GABA receptors, on tonic currents registrated on DGGC. EtOH inhalation causes in hippocampus and in amygdala an increase of the event frequency. In order to evaluate if in stressful conditions there is a increase of the EtOH consumption, we applied the paradigm of mice social isolation (SI). The animals were free to choose EtOH or water, for 2h per day. SI caused an increase of EtOH consumption. The frequency of currents increases in hippocampus and in amygdala. We also found an increase of tonic current induced by THIP in SI mice that drank water. However, this increase was not detected in SI mice that drank EtOH
Nucleotide pirofosfatasi/fosfodiesterasi dal lattice di Euphorbia characias e dai frutti di Opuntia ficus indica: purificazione e caratterizzazione
Get PDFThesis reports on two metallo-proteins nucleotide pyrophosphatase/phosphodiesterase purified from Euphorbia characias latex (ELNPP) and from prickly pear (Opuntia ficus indica) fruits (ONPP).
ELNPP has a molecular mass of 80 kDa and is formed by two apparently identical subunits, each containing 1 Ca²⁺ and 1 Mg²⁺ ion. ONPP is a homodimeric protein displaying a molecular mass of 105 kDa. In this enzyme also is present 1 Ca²⁺ and 1 Mg²⁺ ion in each subunit. Both ELNPP and ONPP are glycosylated proteins, with an optimum pH of 10.0, are stable at high temperatures and are inhibited by AMP and by EDTA. At the moment we are not able to suggest the exact physiological role of ELNPP and ONPP, however, the high catalytic efficiency of hydrolysis of NAD (P) (H), compared to very low activity of other natural substrates tested, suggesting that these enzymes may modulate the activity of dehydrogenase. In addition, it is observed an increase in the enzymatic activity of ONPP from June to August correlated with the possible modulation of the activity of dehydrogenase, leading us to hypothesize that the ONPP may be one of the factors that influence the ripening of fruits.
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La tesi di dottorato riporta la purificazione e caratterizzazione di nucleotide pirofosfatasi/fosfodiesterasi dal lattice di Euphorbia characias (ELNPP) e dai frutti di Opuntia ficus indica (ONPP).
La ELNPP è una metallo proteina con una massa molecolare di 80 kDa, formata da due identiche subunità ognuna contenente uno ione Ca²⁺ e uno ione Mg²⁺. La ONPP è una proteina omodimerica che mostra una massa molecolare di 105 kDa. Anche in questo enzima in ogni subunità è presente uno ione Ca²⁺ e uno ione Mg²⁺. Sia la ELNPP che la ONPP sono proteine glicosilate, hanno un optimum di pH a 10.0, sono stabili ad alte temperature e sono inibite dall’EDTA e dall’AMP. Attualmente non siamo in grado di suggerire l’esatto ruolo fisiologico della ELNPP e della ONPP, tuttavia l'alta efficienza catalitica di idrolisi di NAD(P)(H), rispetto all'attività molto bassa verso gli altri substrati naturali saggiati, suggerisce che questi enzimi possano modulare l’attività delle deidrogenasi. Inoltre, è stato osservato un aumento dell’attività enzimatica della ONPP da giugno ad agosto che, correlato con la possibile modulazione dell’attività delle deidrogenasi, ci porta ad ipotizzare che la ONPP possa essere uno dei fattori che influenzano la maturazione dei frutt
La meteorologia: cammino storico-epistemologico e studio del suo stato attuale di diffusione
Get PDFThe widespread interest in meteorology is mostly driven by the fact that
weather affects our daily life, extending its influence beyond the mere
economical impact.
Despite this strong attention to meteorology it is seen quite differently from
other scientific activities like, for instance, classical physics to which it is
generally, although often unappropriately, associated. This work tries to
highlight the peculiar epistemologic approach to modern meteorology,
through the analysis of the phylosophical and historical paths that have
brought about that approach.
The perception of meteorology as an atypical science it is also due to an
uncomplete, and in some cases even wrong, communication process of
weather forecasts. In this study the main criticalities regarding this
communication process are highlighted through two case studies: the
hurricane Charley twhich hit Florida in 2004 and the intense precipitation that
affected the southern part of Sardinia in 2008.
The evidences drawn from the two case studies are then supported by an
extensive analysis that has involved professional forecasters of 19 different
public Meteorological Offices in Italy and a significant sample of italian and
spanish users. The two groups were surveyed on the meaning they associate
to the typical expressions used in the wetaher reports, about the
comprehension of non categorical, i.e. probabilistic, forecasts and, finally, on
the role of media in the communication process.
The results clearly show the issues and problems still open and help to lay
down some proposals to improve the quality of the communication
techniques, in order to make weather forecasts more effective for the users
Muslim Sardinia in Mediterranean Context
Get PDFDuring the Seventh and the Eighth century A.D., a new cultural and political
presence began to expand in the Mediterranean. The Muslim Empire
extended his influence to many lands, from the Middle East to the West,
then continues in North Africa and ended its march in Europe. Sometimes,
the transitions between different ages entail a complex analysis of facts and
historical dynamics. If a study concerning the Late Antiquity and the Dark
Age, is geographically limited (e.g. only to the West or to the East Mediterranean
sea) or is restricted to an analysis of only one of cultural aspects (e.g.
Christians Romanized or Muslim World), it is known that it is highly influenced
by fields of sectorial studies: the final result is a lack of a far-reaching
perspective. In addition, many ideal barriers between East and West do not
correspond with historic reality: they belong to preconceived and stereotyped
categories. On the other side, the course of history shows that interactions
between cultures are the main instrument for the development of Countries
and communities. Following the common history, we can observe as insular
areas from Western Mediterranean bring a rich research field. Sardinia, for
example, was a part of geographical environment of the new Muslim Empire.
At the beginning, Arabs tried to expand their territory: when this
action failed, they created bases in the island, especially where major cities
and harbours were located. New settlements constituted a useful bridge for
commercial trades and migration fluxes with North Africa. The Arabs were
interested in occupancy of other insular areas (Malta, Sicilia, Pantelleria,
Crete, Cyprus, Rhodes). In this case, evidences connected to Arab and Muslim
culture, should be included in a ’pan-Mediterranean’ context that would
include West and East in a common history
Movements of People for Movements of Goods?
Get PDFWhile it is well established to think of international tourism as a type of exports, namely ‘home’ exports, the potential of tourism flows as an engine for fostering trade among countries is a poorly studied topic. In this paper we show that this relationship can be studied at a very detailed level by exploiting the disaggregation of existing information on international trade and inbound tourism. We consider a sample of 25 countries belonging to the European Union, a region which has been interested by common shocks such as the establishment of the Euro as the new currency for many countries and the liberalization in the air transport market. We carry out a panel data analysis by means of which we assess whether international tourist arrivals by a given country activate additional exports towards the same country. We find not only that tourism can promote exports, but also that this effect displays important differences depending on whether or not consumption goods are considered. This finding is consistent with the idea that the experience of tourists in a given destination reduces the fixed costs of trade, thus facilitating access to the advantages of international trade for more peripheral economies