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Effect of medial prefrontal cortex 6-OHDA lesions on behavioral and neurochemical responses to gustatory stimuli
Get PDFAppetitive sweet tastes increase dopamine (DA) in the nucleus accumbens (NAc) shell and core and in the medial prefrontal cortex (mPFC) in relation to their motivational valence, salience and novelty; the DA increase in the NAc shell is subjected to single trial habituation while in the NAc core and in the mPFC is not. Recently it was shown that sensitization to morphine can reverse these phenomena in the NAc shell and in the mPFC; abolishment of the habituation phenomenon was observed in the NAc shell while in the mPFC single trial habituation took place. Medial prefrontal cortex is an area well known to interact with subcortical areas such as the VTA and the NAc and it has been proposed that DA depletion in the mPFC can alter the mode of function of subcortical areas, including the NAc DAergic responses to pharmacological and environmental challenges of the system. In fact, 6-OHDA lesions of the mPFC have been shown to produce sensitization to the neurochemical and behavioral responses to cocaine and to alter the NAc DAergic transmission in response to natural reinforcers. In the present thesis it was studied the effect of 6-OHDA lesions in the mPFC in the NAc DAergic response to a taste stimulus (sweet chocolate) using in vivo microdialysis. Moreover, behavioral taste reactivity and motor behavior studies were held out to investigate whether the lesions influence this type of behaviors. As in sensitized to morphine animals, lesions produced abolishment of habituation in the NAc shell in the pre-exposed to taste animals, while in the NAc core produced a higher and delayed increase in DA in the naive animals. No differences between lesioned and sham operated animals where observed in naive and pre-exposed animals in the DAergic response of NAc shell and core, respectively. No differences were observed between the groups in taste reactivity test and in the motor activity studies. TH immunoreactivity studies were performed and tissue neurotransmitter levels were quantified in order to evaluate the extension and percentage of the lesions in the mPFC
Valutazione del rischio genetico di comportamento suicidario nel disturbo bipolare: analisi di 737 pedigrees
Get PDFSuicide is a significant cause of mortality in patients with major affective disorders(MAD). Suicidal acts are typically more lethal in MAD. A large contribution to the
suicide risk derives from the presence of family history of suicidal behavior. Other clinical factors, such as treatment with lithium can reduce the suicide risk in patients with MAD. In this work the results of the distribution of suicidal behavior in a large sample of families with bipolar-spectrum disorder, and its relation to family history of MAD and bipolar disorder (BD) are presented.
Methods: The lifetime prevalence of completed and attempted suicides was analyzed in 737 families of probands with MAD with 4,919 first-degree relatives (affected and unaffected). Cox proportional hazard regression models and logistic regression models were used to investigate the role of several clinical covariates on the risk of MAD, BD
and suicidal behavior.
Results: The lifetime prevalence of suicidal behavior (attempted and completed suicides) in 737 probands was at 38.4 ± 3.0%. Among the clinical variables, lithium
treatment was associated with a decreased risk of suicidal behavior in probands (p =0.007). Family history of suicidal behavior contributed significantly to the joint risk of
MAD and suicidal behavior (p = 0.0006) in first-degree relatives.
Conclusions: These findings suggest that the liability to suicidal behavior has significant contribution from partially overlapping genetic factors underlying MAD and
suicidal behavior itself. Even in the presence of high genetic risk for suicidal behavior, lithium treatment seems to decrease significantly the suicide rates
Hydrozincite bioprecipitation: a promising tool for bioremediation of waters contaminated by harmful metals. Hydrochemical factors and morphological features of the biomineralization process
Get PDFThe Ingurtosu Pb-Zn deposit (Sardinia, Italy) was exploited for about a century until 1968. Huge amounts of tailings were abandoned, resulting in long-term harmful metal dispersion processes in both soils and waters. The maximum Zn concentration in waters from the Naracauli stream catchment area attains several hundreds of mg per litre, whereas Cd and Pb concentrations are in the order of thousands of μg per litre, despite the near neutral to slightly alkaline pH values (6.2-8.4). Zn concentration in waters is positively correlated with Pb, Cd, Ni and Co
concentrations. The strongest correlation was observed between Zn and Cd, with a constant Zn/Cd ratio (close to 100) among samples that could suggest the weathering
of a relatively uniform composition of sphalerite from tailings and mine wastes. Waters from tributaries show the lowest concentrations of contaminants. The highest
contents in harmful and toxic elements were observed in waters that drain flotation tailings and mine wastes. Metals concentrations change under different seasonal
conditions. The highest concentrations were observed under high-flow condition (October-April), probably due to the high runoff through the tailings and to aqueous
transport of these metals in association with very fine particles, i.e. <0.4 μm. Zn, Pb, Cd, Cu and Ni concentrations in waters of the Naracauli stream, the main
stream of the area, are abated by the seasonal bioprecipitation of hydrozincite, Zn5(CO3)2(OH)6. Hydrozincite precipitation is promoted by a microbial community made up of a filamentous cyanobacterium (Scytonema sp.) and a microalga (Chlorella sp.). Hydrozincite could be used in a controlled process to attenuate metal pollution in mining waters. Information on environmental conditions that promote the biomineralization process is fundamental for the development of remediation
strategies. This work aims to investigate the variables
controlling the biomineralization process, and the hydrochemical factors that affect hydrozincite precipitation. According to field observations, correlated with speciation and equilibrium calculations, the optimum condition for hydrozincite precipitation occurs in late spring of rainy years, when the hydraulic regime in the stream reaches stationary conditions, and SI values with respect to hydrozincite and pH reach the highest values, in agreement with the higher stability of the hydrozincite solid phase in contact with slightly alkaline waters. Concomitantly, Zn 2+/CO32- molar ratio reaches values close to 1, indicating that kinetic processes have a role on the
hydrozincite biomineralization process. Conversely, heavy rain events occurring in late spring appear to inhibit biomineralization, likely due to the decrease in the SI
values resulting from the dilution effect of rain water.
Results from morphological analysis show that hydrozincite morphology varies, and depends on the environmental conditions. Changes were observed between samples
collected in late spring and samples collected in summer, and among samples precipitated under different water flow conditions. Hydrozincite samples collected in
summer are characterized by globules with a larger diameter than those collected in spring, this variation can be ascribed to a difference in the production of external
mucilage sheaths by cyanobacteria colonies in response to stress conditions. Considering influence of water flow, it was observed that hydrozincite sheaths precipitated under low flow condition have more or less a constant diameter, whereas under high flow conditions sheaths become thinner at the final ends. This particular morphology is due to the influence of hydrodynamics on the structure of the biofilm
and, consequently, on biomineral shape. Diel cycles in dissolved Zn, Co, Ni and Mn were found to occur in a selected station along the Naracauli stream. The highest change in concentration was observed for Zn: the difference between the minimum (3 mg/l) and maximum (4.7 mg/l) Zn
concentrations is 1.7 mg/l (about 35%). The minimum values occurred at h 17:00 and maxima between h 02:00 and h 05:00. The timing of diel cycles in Co and Ni is very similar to that for Zn, but the ranges of Co and Ni concentrations are much smaller than Zn. Increased nocturnal concentrations could result from a combination of geochemical and biological processes. Considering the relations among temperature, pH and Zn contents, temperature and pH would seem to be the parameters that control variations in Zn concentration. Water temperature shows a well defined
diurnal cycle. Maximum water temperature was observed between the h 13:00 and h 17:00. Water temperature varies due to change in air temperature and incident solar
radiation. The pH values vary between 7.7 and 8.1; the highest values were observed during the sunny hours and the lowest during the night or early morning. The diel pH
cycle derives from photosynthesis (predominant during the day) and respiration (predominant during the night). Obtained results may be explained by adsorption-desorption reactions (onto colloids, carbonates, bacterial surfaces and biofilms) and/or different rates of mineral precipitation between the morning and the night time. Diurnal metal cycles should be taken into account to evaluate environmental conditions, potential risks and cleanup of contaminated site
Cost accounting nelle cooperative vitivinicole: problematiche e aspetti metodologici
Get PDFThe knowledge of production costs represents an essential information for management in order to develop successful
business strategies. In the case of cooperatives, these data are even more relevant as they allow the measurement of a company’s performance in relation to its very purpose, that is to say management’s ability to remunerate products conferred by partners more than their market value. In reality, however, cost accounting tools aimed at improving business competitiveness are scarce. This is mainly due
to the high costs incurred for planning and managing such systems, the lack of specialist educational offer and executives’poor corporate culture, since the latter are more focused on technical functions rather than on managerial ones. The purpose of this research is to analyze the typical processes of a winery through the case study of a local cooperative, i.e. the Cantina Sociale di Dolianova. Understanding its processes and dyamics will be functional to the elaboration of a cost accounting pilot model aimed at calculating manufacturing costs. This pilot could serve as a guideline for cooperatives in the wine sector that want to improve their performance. This research brings innovation (to the relevant field of study) in two ways: in designing a cost accounting system based on the latest scholarly contributions, i.e. Time-Driven Activity Based Costing and in proposing the cooperatives a model targeted at determining an estimate of the minimum remuneration for their partners, which should be derived from sales revenues
Ecology, Ecophysiology and Morpho-colorimetric analysis of wild grapevines populations of Sardinia and relationships with some autochthonous cultivars
Get PDFSardinia, with a surface of 24.084 Km2, is the second largest island in the Mediterranean Sea and represents an interesting laboratory, from biological, historical and cultural perspectives, where studies on ecology, ecophysiology and morpho-colorimetric analysis of wild grapevines populations and relationships with some autochthonous cultivars can be carried out. The peculiar insular condition of Sardinia and the large population of wild grapevine coenosis distributed in the whole island, allowed the local inhabitants to develop independent
domestication processes. Infact, the wine heritage in Sardinia consists of 210 cultivars. Among these cultivars, 151 are considered as local true varieties and the result of different events, such as the direct domestication of wild grape, crosses between local varieties and the importation of agricultural techniques and cultivars from different ethnic groups that colonised the Island. The
remaining 69 varieties can be considered as false attributions (synonyms and/or homonyms) due to
the existence of different dialects within the same territory. The observations made in the field in order to detect the presence of young seedlings in the
various island populations confirm that the germination period ranges from February to May and at the same time, the germination phenology limits the species distribution, in Sardinia, along riverbanks or colluvial sites of hilly humid slopes (as in most wild grapevine populations found in
Europe) where seedlings can grow even during the dry summer conditions, suggesting a phenotypic adaptation to different microclimates. Through the measurement of 113 morpho-colorimetric discriminant parameters on seeds, of
which: 33 coming from morpho-colorimetric measurements and 80 coming from the EFDs method we have obtained some statistical classifiers capable to identify, classify the studied cultivars of Vitis vinifera L. subsp. vinifera and to compare them with some wild populations of Vitis vinifera L. subsp. sylvestris (C.C. Gmel) Hegi and some archaeological remains of seeds founded in Sardinia.
The use of 93 morphological parameters in the study of the archaeological seeds found in the prenuragic and nuragic site of Sa Osa has permitted their classification as white grapes for dessert wine, still today cultivated under the name of Vernaccia. Moreover, the image analysis technique has been used to investigate the various groups of
synonymy and homonymy previously proposed on the basis of the Simple Sequence Repeat (SSR) marker providing high percentage values of correct identification of each group and showing a certain correspondence to the phenotypic seed characters- This results simultaneously suggests some potential modifications to the proposed groupings
Organizzazioni Non Governative e Società Civile nel processo di transizione democratica in Kenya (1991 -2002)
Get PDFA new era of multiparty politics in Kenya began in December 1991, when President Daniel Arap Moi repealed the constitutional clause that enshrined the Kenya African
National Union (KANU) as the sole political party.
Despite widespread unpopularity, Moi won the presidential elections and his party secured a majority in parliament in the following two general elections, held in December 1992 and December 1997. This doctoral thesis is structured in five parts. The first part takes a historical perspective of African’s Civil Movements and seeks to put into context of African’s State. The second part takes a historical reconstruction of Kenya’s Political Transiction. The third part traces and analyses the rule of Civil Association and
particulary and examines and analyses NCEC's activities in its quest for constitutional reforms. The fourth part examines as aid donors played a central part not only in
initially advancing the cause of multipartyism. The last part analyses the political role of NGOs
Standard di crescita per la valutazione dello stato di salute della popolazione sarda
Get PDFThe assessment of growth is an important part of paediatrics and community child health. Among anthropometric measurements the height is measured in order to diagnose abnormal height growth rates and to monitor the results of any treatment for such conditions. Weight is another important growth parameter, which provides information about the individual’s nutritional status. The Body Mass Index (BMI = kg/m2) is used to identify cases of overweight or underweight and to monitor nutritional status. On regard cephalometric measures there exist few standards for circumference, length and breadth of head from childhood to adulthood in populations of European extraction. Moreover, the international standards are based on samples that cannot be appropriately used as references for all populations since they were taken from different ethnic groups and from different periods. The aims of this study were: (1) to test whether international or national standards can be used to assess the Sardinian population; and (2) to produce growth charts for stature, weight, BMI, head circumference, length and breadth for Sardinian males and females from 3 to 22 years of age. The cross sectional sample consisted of 9,721 subjects of Sardinian origin (4,884 males and 4,837 females), aged 3–22 years, measured from 1998 to 2008. Growth percentiles were produced with the LMS method. The results show that the international or even national standards are not appropriate for the assessment of Sardinian children. For the Sardinian population, specific regional growth charts should be used to correctly evaluate the normal range and the cut-off points of the extreme percentiles
Essays on fiscal policies and tax evasion
Get PDFBroadly speaking, this dissertation studies fiscal policy mechanisms governments set to retrieve the revenues needed for public expenditure. More concretely, the main question is if these asymmetrical information mechanisms lead to a “desired purpose” and whether they are indeed optimal
and fair for both governments and taxpayers. It appears that fiscal policies are among the main forces of unfairness and are an obstacle for new small businesses and practitioners and may also hamper the economic growth of
most (developing) countries. The first chapter discusses what we already know about tax evasion and the optimal choice of the latter. Although the scope of this thesis is to go beyond a comprehensive literature review, this initial phase builds an existing solid basis to the rest of the work. This first part presents the different processes of how a taxpayer faces the “evasion choice”, as well as the different analytical models which have been used in this field. The second chapter focuses on a widespread practice for governments, which is to gather observable and measurable characteristics of taxpayers and to group the population into homogeneous categories in order to better estimate their real gross income. Although it is common to keep income estimates hidden, in Italy these are announced to the taxpayers before the latter are asked to fill in their tax declarations. The mechanism used in Italy is called Sector Studies (in Italian “Studi di Settore”) and relies on taxpayers’ gathered information both to partition the population into fairly homogeneous clusters and to determine their presumed income that they ought to declare. The Sector Studies mechanism relies on a cut-off policy:
once the government choses and announces the estimated income, it is common knowledge that all taxpayers who declare less than this estimation are surely audited. Thus, it is an asymmetrical information mechanism where taxpayers enjoy the informational advantage. The problem that a taxpayer faces when deciding their declaration in such
a scenario is analyzed. The principal aim is to understand whether this cut-off policy is indeed optimal for the government and if it is fair to the taxpayers. Starting from what is happening in Italy - that is the greatest
part of the population declares its estimated income but there is always a group that declares differently - a theoretical model is constructed where the income distribution is fixed and audits are costly for both government and taxpayers. The main finding is the characterization of the solution to the taxpayer’s
problem. When taxpayers are risk-neutral and uniformly distributed in a given segment, the cut-off policy gives rise to three different groups into which taxpayers are endogenously divided. The lowest group is audited
with certainty, so that agents bear the audit cost and no individual dishonestly reports her income (Compliance Taxpayers). Reports in the middle group are equal to the estimated income (Over-Declaration) so that no one
is audited but individuals pay more taxes than due (Fake Congruous). Declarations in the highest group are equal to the estimated income so that no one is audited but since individuals’ real income is greater than the estimated one, they pay less taxes than due and so evade (Evaders). The third chapter addresses another fiscal mechanism concerning the exchange of information and revenue-sharing in tax-treaties. Basically, the situation where firms of a developed country can produce some revenues in a developing one is modeled and analyzed. In such a situation, worldwide income taxation in the country of residence is the legal dogma of international taxation commonly used. This dogma is questioned from the perspective of relations with developing countries from a legal and economic perspective,
and a modern and fair proposal for tax treaties is made. It is shown under which conditions a developing and a developed country will voluntarily sign a tax treaty where information is exchanged truthfully and whether they should share revenues. Moreover, it proves how the conclusion of a tax treaty can assist in the implementation of a tax audit system
Identification and mode of action studies of new potent inhibitors of the RNA viruses HCV, BVDV and RSV
Get PDFSeveral of worldwide emerging infections are caused by RNA viruses. For this reason, research in the antiviral chemotherapy field is directed toward the development of compounds that target various steps of the virus life cycle. In this work the antiviral activity of 5-Acetyl-2-
Arylbenzimidazoles and 2-[(benzotriazol-1/2 yl)methyl]benzimidazoles has been evaluated against
representatives of several virus families, including HCV BVDV, YFV, REO-1, CVB-5, Sb-1 and RSV. Some of the new derivatives turned out to be very interesting for their potency and selectivity against BVDV and HCV (the former), and RSV (the latter), and could be promising candidates for
the treatment of the related diseases
La politica navale della Spagna della Spagna nel fronte mediterraneo (1635-1678)
Get PDFDuring the XVI Century the warlike vocation of the reign of Castiglia, shaped during the centuries of the Reconquista, and the wars conducted by the Absburgs towards many frontlines, gave a great contribution for the creation of a strong burocratic structure which gave the opportunity made possible to Spain to give itself a modern country
dimension. Particularly, a great impulse for the empowerment of the administrative structure came from the development and the complex management of the military fleet, committed in the Mediterranean area in many naval activities against Turks. In the first half of the XVII century Spain was forced to display all its immense
military potential during the long conflict that interested the countries of half Europe between 1618 and 1648: the Thirty Years War. To sustain the expensive politics of intervention, all the reigns of the Crown were called to give their contribution. Among them, also Sardinia, in spite of her poverty and marginality, joined with conviction the politic project of the Unión de Armas.
The opening of the new front against France, in 1635, risked to bring the monarchy into collapse: insurrections and revolts exploded in Portugal, Catalogna and in the
Reigns of Naples and Sicily; in the Atlantic sea the Armada del Mar Océano had terrible defeats by nordish fleets; while in the mainland the tercios lost their primacy of
unbeatability. Only the Mediterranean fleets of galleys, even if strongly reduced, compared to the previous century, and technologically overtaken by the sail ships, even
if did not succeed in dominating could at least contrast the enemy and preserve in some kind the precious vital space of a power already in decline