UniCA Eprints

    A meteo-hydrological forecasting chain: performance of the downscaling and rainfall-runoff steps in a small catchment

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    Forecasting ground effects of severe meteorological events with an adequate lead time is fundamental for civil protection scopes and is therefore an important challenge for the scientific community. The paper focuses on the performance of some steps of a meteo-hydrological forecasting chain that can be applied in small watersheds to assess hydrological risk deriving by an intense storm predicted at the large meteorological scale. The proposed procedure integrates large-scale rainfall fields, as those produced by numerical weather prediction (NWP) models, with statistical rainfall downscaling and hydrological modelling. More in details, assuming a large scale rain rate as the input of the process, the forecasting chain produces an ensemble of hydrographs that are post-processed in order to give a probabilistic representation of mean streamflow maxima for different time windows. The outcome of this procedure can be thus applied to assess the risk that some critical streamflow thresholds may be exceeded. The procedure has been tested on more than one thousand recorded events in the Araxisi catchment in Sardinia, Italy. Results and performances are presented and discussed

    What determines entrepreneurial clusters?

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    We contrast two potential explanations of the substantial differences in entrepreneurial activity observed across geographical areas: entry costs and external effects. We extend the Lucas model of entrepreneurship to allow for heterogeneous entry costs and for externalities that shift the distribution of entrepreneurial talents. We show that these assumptions have opposite predictions on the relation between entrepreneurial activity and firm level TFP: with different entry costs, in areas with more entrepreneurs firms’ average productivity should be lower and vice versa. We test these implications on a sample of Italian firms and unambiguously reject the entry costs explanation in favor of the externalities one. We also investigate the sources of external effects, finding robust evidence that learning externalities are an important determinant of cross-sectional differences in entrepreneurial activit

    Variazione di alcuni indici fitoclimatici osservati a Cagliari dal 1892 al 2002

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    Analyzing the thermopluviometric data of Cagliari from 1892 to 2002, have been processed the most important phytoclimatic indices reported both to whole time and to five equivalent periods. The achieved results, confirmed by the all calculated indices, point out a shifting towards conditions of greater dryness, more obvious in the last years, determining in the local floras an increase of annual species

    Convergence clubs and the role of human capital in spanish regional growth

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    This paper estimates returns to schooling at Spanish regional level. We identify two different convergence clubs of rich/educated and poor/uneducated regions. Overall our results stress the importance of the relationship existing between the level of development of an economy and returns to different levels of education. In particular, the Spanish evidence suggests that, while primary schooling seems to contribute to growth in poorly developed areas, more skilled human capital has a stronger growth-enhancing effect in more developed economies. In other words, our evidence emphasizes that there is likely to be heterogeneity in rates of returns to education across economies since the effect of schooling in growth regressions is influenced by the level of development of an economy. Failing to take this heterogeneity into account in empirical analysis may produce misleading result

    Patti Territoriali e specializzazione produttiva nel Mezzogiorno

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    I patti territoriali rappresentano uno strumento della programmazione negoziata capace, nelle intenzioni, di cogliere le istanze provenienti dal territorio. Analizzando la composizione territoriale e la specializzazione settoriale dei patti operanti nelle regioni meridionali il lavoro si domanda in quale misura questo obiettivo sia stato conseguito. Sulla base di una prima analisi ancora parziale a causa dell'incompletezza dei dati disponibili, l'articolazione territoriale dei patti appare molto influenzata dalle sfere di competenza dei soggetti istituzionali promotori ma raramente riflette la geografia delle aree sistema presenti nel Mezzogiorno e le loro interdipendenze. Anche dal punto di vista della specializzazione settoriale i risultati dell'analisi suggeriscono che i sistemi produttivi locali meridionali hanno svolto un ruolo limitato nella determinazione della composizione settoriale degli investimenti previsti nei patti

    Invidia e imprenditorialità. Alcune note sul ruolo delle emozioni nello sviluppo economico

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    The main hypothesis of this paper is that envy may play a role, although hardly quantifible, in the explanation of economic backwardness. Its main effect is to stimulate social reaction and opposition against entrepreneurial effort and innovative behavior which inhibit the development of a diffused entrepreneurial attitude in the population. This is more likely to happen in the transition phase from an agrarian economy to industrial development when income distribution becomes more uneven and envy still acts as a control device against social differentiation in a subsistence economy. More generally the paper argues that extending the framework of rational choice to include emotions may help to go deeper into the social mechanics of economic development

    Interazioni trofiche tra Condroitti in Mediterraneo

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    Chondrichthyans play an important ecological role, they tend to be high in the food web being very often predators at the top of marine food webs (Cortés, 1999; Ebert e Bizzarro, 2007). Sharks and rays appear to be particularly vulnerable to over-exploitation because of their K-selected life-history strategy (Cailliet et al., 2005). Therefore, given that the consequences of their intense exploitation could be very dangerous, many authors have stressed their vulnerability (Bonfil, 1994; Cahmi et al., 1998; Stevens et al., 2000; Fowler & Cavanagh, 2005) and the importance of their protection (Fowler & Cavanagh, 2005), unfortunately not so effective (Cavanagh e Gibson, 2004). Currently, many efforts are made in order to clarify and to better understand the functioning of marine ecosystems, for the purpose of an enhanced management. An exhaustive study of feeding habits and trophic interactions between species is required to obtain this information (Stevens et al., 2005), nevertheless data from literature regard a limited number of species. All that has provided the opportunity to undertake the analysis of feeding habits and trophic relationships between all the Chondrichthyans caught in Sardinian waters by trawler, in order to provide an overall view about the interactions that rule the funtcioning of marine ecosystems and energetic exchanges. Moreover, for the purpose of a better management, we have assessed the fishing impact on this important taxonomic group. All of these aims were obtained through stomach content analysis of all the species caught in the course of three years of study, taking into account some important factors as sex, size and depth that could influence the diet. Intraspecific and interspecific niche overlap, Trophic index and its trend were also determined in order to assess state of exploitation of Chondrichthyans. We analyzed the diet of 27 species M. punctulatus and D. nidarosiensis are new records for Sardinian waters and Mediterranean Sea respectively.,Among these, 14 species were caught occasionally or presented a high percentage of empty stomachs, so it was possible to provide only a preys list. Generally, some similarities could be noticed between all the species. The niche breadth was larger in the specimens caught at the deepest strata, likely due to their adaptation to oligotrophic conditions, characteristic of the deepest habitats. With variable proportions species prey on Crustaceans, Teleosts and Cephalopods, and minorly on Chondrichthyans too. Two distinct way of feeding, deeply influenced by body morphology. Batoids prey mainly on benthopelagic and benthic organisms, while shark-like species prefer nectonic preys or organisms more swimming prone. A few number of preys, characterized by a great abundance in the habitats that inhabit, represent the core of the diet of all the analyzed species. Mysids, like Gastrosaccus sanctus and Lophogaster typicus, Brachyurans of the genus Liocarcinus sp, Natantians as Solenocera membranacea, Pasiphaea multidentata and P. sivado, the euphausiid Meganyctiphanes norvegica and the Cefalopods belonging to the family Sepiolidae (mainly Heteroteuthis dispar) are the most representative. Moreover, teleostes like Gymnammodytes cicerelus and Glossanodon leioglossus are exploited by some species. Ontogenetic variation in feeding habits were noticed: in general small specimens eat small preys, especially benthic ones (crustaceans, small teleosts and sepiolids). With the growth preys bigger and more swimming prone become more important in the diet of all the species. Similarly, trophic index values increase with the growth, maintaining low levels of competition between species and improving survival rate of juveniles. Speaking generally, trophic level increase for species that prefer pelagic preys. No differences in trophic spectrum were observed among sexes that, in fact, are characterized by a high value of niche overlap. The analysis of the diet in function of depth does not show any significant difference, except for species that present a different bathymetric segregation. Niche overlaps analysis points out a greater interspecific competition between specimens of the deepest strata. These environments are characterized by oligotrophic conditions that lead to an intensive exploitation of a limited number of preys, thus maximizing the overlap between diets. Marine trophic index, estimated for MEDITS target species from 1994 to 2010, showed an increasing trend, probably related to the change in the Sardinian fishing fleet occurred at the beginning of the nineties. Marine trophic index for Chondrichthyans remained stable until 2001, then oscillated and, finally, tended do decrease slightly. The study allowed to discover a complex web of trophic interactions. Some results disagree with those reported in literature, indicating the existence of a big variety, also within the same species, related to geographical differences. More studies would be necessary to extend knowledge about the interactions that control the functioning of the ecosystems and to prevent the decline of this taxon, avoiding the negative effects of its loss. The final aim will be to provide appropriate management measures very soon, in order to ensure the protection of Chondrichthyans

    I sistemi di controllo interno negli enti locali: i casi tedesco e italiano a confronto

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    The research analyses the development of internal control systems in German and Italian municipalities. The modernization process of public administrations promoted by the New Public Management movement has implied worldwide the adoption of private sector derived techniques and tools in order to improve public management. According to the literature, the adoption of internal control systems, together with the improvement of accounting and auditing techniques, can help to increase the level of efficiency, effectiveness, accountability and transparency of public sector organizations. Moreover, internal control systems are a useful tool for the ethical execution of operations and for corruption prevention, which are two keystone for public sector. The reform trajectories followed by the countries have been different. In particular, the reform process was slow in “Rechtsstaat” or legal state countries, like Germany and Italy. The reform process in these two countries, which are the object of this study, started later as in the other OECD countries and implied the adaptation of the proposed tool and techniques to the existing administrative system. Moreover, in the two countries the process of innovation started and has been more advanced at the local government level. The municipality level was therefore chosen as the object of the study. A second reason for this choice lies in the fact that the municipality level allowed a homogeneous comparison between the two countries. Indeed, they have a different state structure, Italy is a unitary state and Germany is a federal republic; the lowest level of government is the one that allows a homogeneous comparison. The study is aimed at: a) describing the characteristics (objectives and components) of internal control systems in German and Italian municipalities, compared to private sector standards concerning internal control systems; b) comparing the internal control systems of the two countries in order to identify their similarities and differences. Considering that the ethical execution of operations and the prevention of corruption are two keystones for public sector, one additional purpose was to ascertain if these need produce effects on the internal control system adopted. The research is mainly based on the analysis of the laws and regulations issued on this topic and uses an internationally accepted standard – the CoSO model for internal control systems – as a framework for the analysis and the comparison between the two countries. As in both countries the municipalities have a high level of autonomy, two case study, two towns, were selected to complete the general analysis and to deal with the third objective of the research. The selected towns, one Italian and one German, have in fact undergone a process of restructuring and of improvement of their administration, which is aimed at dealing with the problem of ethics (Italian town) and corruption (German town). The analysis conducted shows that both countries are with different approaches and different solutions moving towards the international standards

    Sindromi drepanocitiche: studio di fattibilità di strategie di prevenzione e rimodellamento della rete assistenziale in un contesto in evoluzione

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    Sickle cell disease (SCD) is the first genetic disease in the world and remains largely ignored by the population but also by health professionals. SCD is characterized by a variable clinical expression; however most of the patients are at risk to develop acute and severe complications conducting to a fatal issue. Reliable and accurate epidemiological data is a prerequisite for a cost effective prevention program for inherited disorders, which however, is lacking in a number of developing countries. Here we report the first detailed population study in the Piedmont region, north-west Italy, designed to estimate the frequency and distribution of patients with sickle cell disease, annual number of patients newly diagnosed as having SCD, proportion of the patients receiving a regular care in a comprehensive care setting. This study analyzes the adequacy between the services offered for these patients and the real need in this Italian country. OBJECTIVE: The purpose is to estimate the prevalence of sickle cell disease in the Piedmont region and the need for prevention strategies, to evaluate the feasibility of neonatal screening and to propose a realistic healthcare program. METHODS: The estimate of the SCD prevalence changes between January 1978 and December 2011 in the Piedmont region was based on three regional data sources. All consecutive patients with SCD laboratoristic diagnosis were included and specialistic care was offered. For all patients, the demographic and clinical features and the circumstances of SCD diagnosis were described. The next step was to analyse the current prevention and healthcare program in this country and to evaluate the feasibility of a new specific cost effective program and to improve management of sickle cell disease through early parental education and the institution of prophylaxis against infection. RESULTS: According to information obtained from the regional sources, our results indicate that the prevalence of SCD population was 0,022/1000 in 2011 versus 0,008/1000 in 1991; the SCD distribution is heterogeneous in the region. In the next 10 years, the annual incidence was augmented and the changing patterns of immigration, in particular recent African immigration, led to significant numbers of neonates at risk of sickle cell disease (70% of SCD population has not Italian origin or ethnicity). The current healthcare program assures a good survival and quality of life; the prevention program is not complete and neonatal newborn screening is not available but feasible. CONCLUSIONS: Our results are consistent with a changing of the sickle cell disease epidemiology in the Piedmont region with a specific regional distribution; a paucity of high-quality data limits appropriate estimation. The management of SCD requires a dedicated approach; this study support the notion that the healthcare for hemoglobinopathies can benefit from a specific prevention program as neonatal haemoglobinopathies newborn screening despite the logistic problems and economic constraints. The development of prevention as the same time as specific clinical program is pivotal to improving SCD healthcare in this Italian region

    Politiche e strumenti per la reinterpretazione dei paesaggi produttivi estrattivi in ambito costiero: la Sardegna come caso di studio nel contesto euro-mediterraneo

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    The research deals with the subject of protection, development and reuse of disused extraction landscapes; the overall aim is to develop policies and tools for the reinterpretation of these areas through proposals which are able to take the opportunities arising from a systemic and interdisciplinary approach. The study analyzes both ancient and modern quarries, in accordance with the definition suggested by the research and highlights, through context analysis, the different methodological approaches aimed at tackling the main issues of the disused quarry sites. The sphere of analysis is that of coastal areas, with particular reference to the situation in Sardinia. The regional case of study, and the specific case of the city of Cagliari, allow to contextualise the planning scenario, offering the opportunity to verify the effectiveness of policies and tools which are already in place and to define new operational proposals. The experiences analysed provide the elements needed to set up guidelines, designed as support instruments for the policies for reinterpretation of the quarry areas. The guidelines are put together using a multi-criteria evaluation model based on the Analytic Hierarchy Process (AHP) (Saaty, 1980, 1988, 2001); this experimentation uses a scientific method and guarantees the identification of functional criteria for the definition of intervention priorities and long-term policies to be implemented in disused areas. The sites under examination are characterized by the presence of features related to the extractive history which deserve to be valued even if the quarries have ceased their activity in recent years. The research codifies existing policies and tools which support the reinterpretation of the quarry areas, the critical issues related to the processes, the opportunities arising from the scenario which has been analysed, and missed opportunities. The problematic issues which are found are addressed by proposals aimed at encouraging the paths of intervention in quarry sites and formulating policies and tools in structured paths. These proposals are aimed at outlining scenarios which are compatible with the territorial dynamics in place, and with renewed principles of protection and enhancement of the landscape, in order to overcome the fragmentation of the planning framework that emerges clearly from the performed context analysis
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