Evaluation of fluid transport processes in dental enamel. Methods to assess the relevance of enamel permeability in caries prevention and etching treatments.

This thesis evaluated in vivo and in vitro enamel permeability in different physiological and clinical conditions by means of SEM inspection of replicas of enamel surface obtained from polyvinyl siloxane impressions subsequently later cast in polyether impression ma-terial. This technique, not invasive and risk-free, allows the evaluation of fluid outflow from enamel surface and is able to detect the presence of small quantities of fluid, visu-alized as droplets. Fluid outflow on enamel surface represents enamel permeability. This property has a paramount importance in enamel physiolgy and pathology although its ef-fective role in adhesion, caries pathogenesis and prevention today is still not fully under-stood. The aim of the studies proposed was to evaluate enamel permeability changes in differ-ent conditions and to correlate the findings with the actual knowledge about enamel physiology, caries pathogenesis, fluoride and etchinhg treatments. To obtain confirmed data the replica technique has been supported by others specific techniques such as Ra-man and IR spectroscopy and EDX analysis. The first study carried out visualized fluid movement through dental enamel in vivo con-firmed that enamel is a permeable substrate and demonstrated that age and enamel per-meability are closely related. Examined samples from subjects of different ages showed a decreasing number and size of droplets with increasing age: freshly erupted permanent teeth showed many droplets covering the entire enamel surface. Droplets in permanent teeth were prominent along enamel perikymata. These results obtained through SEM inspection of replicas allowed innovative remarks in enamel physiology. An analogous testing has been developed for evaluation of enamel permeability in primary enamel. The results of this second study showed that primary enamel revealed a substantive permeability with droplets covering the entire enamel sur-face without any specific localization accordingly with histological features, without changes during aging signs of post-eruptive maturation. These results confirmed clinical data that showed a higher caries susceptibility for primary enamel and suggested a strong relationship between this one and enamel permeability. Topical fluoride application represents the gold standard for caries prevention although the mechanism of cariostatic effect of fluoride still needs to be clarified. The effects of topical fluoride application on enamel permeability were evaluated. Particularly two dif-ferent treatments (NaF and APF), with different pH, were examined. The major product of topical fluoride application was the deposition of CaF2-like globules. Replicas inspec-tion before and after both treatments at different times intervals and after specific addi-tional clinical interventions showed that such globule formed in vivo could be removed by professional toothbrushing, sonically and chemically by KOH. The results obtained in relation to enamel permeability showed that fluoride treatments temporarily reduced enamel water permeability when CaF2-like globules were removed. The in vivo perma-nence of decreased enamel permeability after CaF2 globules removal has been demon-strated for 1 h for NaF treated teeth and for at least 7 days for APF treated teeth. Important clinical consideration moved from these results. In fact the caries-preventing action of fluoride application may be due, in part, to its ability to decrease enamel water permeability and CaF2 like-globules seem to be indirectly involved in enamel protection over time maintaining low permeability. Others results obtained by metallographic microscope and SEM/EDX analyses of or-thodontic resins fluoride releasing and not demonstrated the relevance of topical fluo-ride application in decreasing the demineralization marks and modifying the chemical composition of the enamel in the treated area. These data obtained in both the experiments confirmed the efficacy of fluoride in caries prevention and contribute to clarify its mechanism of action. Adhesive dentistry is the gold standard for caries treatment and tooth rehabilitation and is founded on important chemical and physical principles involving both enamel and dentine substrates. Particularly acid etching of dental enamel enamel has usually employed in bonding pro-cedures increasing microscopic roughness. Different acids have been tested in the litera-ture suggesting several etching procedures. The acid-induced structural transformations in enamel after different etching treatments by means of Raman and IR spectroscopy analysis were evaluated and these findings were correlated with enamel permeability. Conventional etching with 37% phosphoric acid gel (H3PO4) for 30 s and etching with 15 % HCl for 120 s were investigated. Raman and IR spectroscopy showed that the treatment with both hydrochloric and phosphoric acids induced a decrease in the carbonate content of the enamel apatite. At the same time, both acids induced the formation of HPO42- ions. After H3PO4 treatment the bands due to the organic component of enamel decreased in intensity, while in-creased after HCl treatment. Replicas of H3PO4 treated enamel showed a strongly reduced permeability while replicas of HCl 15% treated samples showed a maintained permeability. A decrease of the enamel organic component, as resulted after H3PO4 treatment, involves a decrease in enamel permeability, while the increase of the organic matter (achieved by HCl treat-ment) still maintains enamel permeability. These results suggested a correlation between the amount of the organic matter, enamel permeability and caries. The results of the different studies carried out in this thesis contributed to clarify and improve the knowledge about enamel properties with important rebounds in theoretical and clinical aspects of Dentistry.

Strategies and procedures for the development of intermodal freight transport in Europe: the role of motorways of the sea services and railway terminals

Since the birth of the European Union on 1957, the development of a single market through the integration of national freight transport networks has been one of the most important points in the European Union agenda. Increasingly congested motorways, rising oil prices and concerns about environment and climate change require the optimization of transport systems and transport processes. The best solution should be the intermodal transport, in which the most efficient transport options are used for the different legs of transport. This thesis examines the problem of defining innovative strategies and procedures for the sustainable development of intermodal freight transport in Europe. In particular, the role of maritime transport and railway transport in the intermodal chain are examined in depth, as these modes are recognized to be environmentally friendly and energy efficient. Maritime transport is the only mode that has kept pace with the fast growth in road transport, but it is necessary to promote the full exploitation of it by involving short sea shipping as an integrated service in the intermodal door-to-door supply chain and by improving port accessibility. The role of Motorways of the Sea services as part of the Trans-European Transport Network is is taken into account: a picture of the European policy and a state of the art of the Italian Motorways of the Sea system are reported. Afterwards, the focus shifts from line to node problems: the role of intermodal railway terminals in the transport chain is discussed. In particular, the last mile process is taken into account, as it is crucial in order to exploit the full capacity of an intermodal terminal. The difference between the present last mile planning models of Bologna Interporto and Verona Quadrante Europa is described and discussed. Finally, a new approach to railway intermodal terminal planning and management is introduced, by describing the case of "Terminal Gate" at Verona Quadrante Europa. Some proposals to favour the integrate management of "Terminal Gate" and the allocation of its capacity are drawn up.

Business Clusters in Eastern Europe: Policy Analysis and Cluster Performance

Clusters have increasingly become an essential part of policy discourses at all levels, EU, national, regional, dealing with regional development, competitiveness, innovation, entrepreneurship, SMEs. These impressive efforts in promoting the concept of clusters on the policy-making arena have been accompanied by much less academic and scientific research work investigating the actual economic performance of firms in clusters, the design and execution of cluster policies and going beyond singular case studies to a more methodologically integrated and comparative approach to the study of clusters and their real-world impact. The theoretical background is far from being consolidated and there is a variety of methodologies and approaches for studying and interpreting this phenomenon while at the same time little comparability among studies on actual cluster performances. The conceptual framework of clustering suggests that they affect performance but theory makes little prediction as to the ultimate distribution of the value being created by clusters. This thesis takes the case of Eastern European countries for two reasons. One is that clusters, as coopetitive environments, are a new phenomenon as the previous centrally-based system did not allow for such types of firm organizations. The other is that, as new EU member states, they have been subject to the increased popularization of the cluster policy approach by the European Commission, especially in the framework of the National Reform Programmes related to the Lisbon objectives. The originality of the work lays in the fact that starting from an overview of theoretical contributions on clustering, it offers a comparative empirical study of clusters in transition countries. There have been very few examples in the literature that attempt to examine cluster performance in a comparative cross-country perspective. It adds to this an analysis of cluster policies and their implementation or lack of such as a way to analyse the way the cluster concept has been introduced to transition economies. Our findings show that the implementation of cluster policies does vary across countries with some countries which have embraced it more than others. The specific modes of implementation, however, are very similar, based mostly on soft measures such as funding for cluster initiatives, usually directed towards the creation of cluster management structures or cluster facilitators. They are essentially founded on a common assumption that the added values of clusters is in the creation of linkages among firms, human capital, skills and knowledge at the local level, most often perceived as the regional level. Often times geographical proximity is not a necessary element in the application process and cluster application are very similar to network membership. Cluster mapping is rarely a factor in the selection of cluster initiatives for funding and the relative question about critical mass and expected outcomes is not considered. In fact, monitoring and evaluation are not elements of the cluster policy cycle which have received a lot of attention. Bulgaria and the Czech Republic are the countries which have implemented cluster policies most decisively, Hungary and Poland have made significant efforts, while Slovakia and Romania have only sporadically and not systematically used cluster initiatives. When examining whether, in fact, firms located within regional clusters perform better and are more efficient than similar firms outside clusters, we do find positive results across countries and across sectors. The only country with negative impact from being located in a cluster is the Czech Republic.

From fall-risk assessment to fall detection: inertial sensors in the clinical routine and daily life

Falls are caused by complex interaction between multiple risk factors which may be modified by age, disease and environment. A variety of methods and tools for fall risk assessment have been proposed, but none of which is universally accepted. Existing tools are generally not capable of providing a quantitative predictive assessment of fall risk. The need for objective, cost-effective and clinically applicable methods would enable quantitative assessment of fall risk on a subject-specific basis. Tracking objectively falls risk could provide timely feedback about the effectiveness of administered interventions enabling intervention strategies to be modified or changed if found to be ineffective. Moreover, some of the fundamental factors leading to falls and what actually happens during a fall remain unclear. Objectively documented and measured falls are needed to improve knowledge of fall in order to develop more effective prevention strategies and prolong independent living. In the last decade, several research groups have developed sensor-based automatic or semi-automatic fall risk assessment tools using wearable inertial sensors. This approach may also serve to detect falls. At the moment, i) several fall-risk assessment studies based on inertial sensors, even if promising, lack of a biomechanical model-based approach which could provide accurate and more detailed measurements of interests (e.g., joint moments, forces) and ii) the number of published real-world fall data of older people in a real-world environment is minimal since most authors have used simulations with healthy volunteers as a surrogate for real-world falls. With these limitations in mind, this thesis aims i) to suggest a novel method for the kinematics and dynamics evaluation of functional motor tasks, often used in clinics for the fall-risk evaluation, through a body sensor network and a biomechanical approach and ii) to define the guidelines for a fall detection algorithm based on a real-world fall database availability.

New associations between native parasitoids and exotic insects introduced in Italy and in Europe

The introduction of exotic species is one of the most important threats to biodiversity.This phenomenon may cause economic and environmental damage. To prevent these invasions there are institutions like EPPO. Nevertheless, the introduction of exotic pests is an increasing issue, difficult to control. Classic biological control, based on importation of natural enemies from the country of origin, has been successfully used for over 120 years, but it has also raised some criticism. My research work has focused on the study of the new associations occurring between indigenous parasitoids and three exotic pests introduced in Italy and Europe. The three target insects considered were: Cacyreus marshalli Butler (Lepidoptera: Lycaenidae), a pest of Geranium plants; Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), a plague of Castanea sp. and Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). This ladybug has been introduced as a biological control agent, but since some years it considered as an invasive species. For C. marshalli I performed laboratory tests on acceptance and suitability of immature stages of this butterfly by Exorista larvarum (Diptera: Tachinidae) and Brachymeria tibialis (Hymenoptera: Chalcidicae). The experiments showed that these two parasitoids could be used to contain this pest. For D. kuriphilus I performed field samplings in an infested chestnut area, the samples were maintained in rearing chamber until gall wasp or parasitoids emergence. In the 3-year research many parasitoids of gall wasps were found; one of these, Torymus flavipes (Walker), was found in large number. For H. axyridis the research work included a first phase of field sampling, during which I searched indigenous parasitoids which had adapted to this new host; the only species found was Dinocampus coccinellae (Schrank) (Hymenoptera: Braconidae). Laboratory tests were performed on the wasp rearing, biology and capacity to contain H. axyridis.

Sanctions and public enforcement of insider trading laws in Europe

The recent financial crisis triggered an increasing demand for financial regulation to counteract the potential negative economic effects of the evermore complex operations and instruments available on financial markets. As a result, insider trading regulation counts amongst the relatively recent but particularly active regulation battles in Europe and overseas. Claims for more transparency and equitable securities markets proliferate, ranging from concerns about investor protection to global market stability. The internationalization of the world’s securities market has challenged traditional notions of regulation and enforcement. Considering that insider trading is currently forbidden all over Europe, this study follows a law and economics approach in identifying how this prohibition should be enforced. More precisely, the study investigates first whether criminal law is necessary under all circumstances to enforce insider trading; second, if it should be introduced at EU level. This study provides evidence of law and economics theoretical logic underlying the legal mechanisms that guide sanctioning and public enforcement of the insider trading prohibition by identifying optimal forms, natures and types of sanctions that effectively induce insider trading deterrence. The analysis further aims to reveal the economic rationality that drives the potential need for harmonization of criminal enforcement of insider trading laws within the European environment by proceeding to a comparative analysis of the current legislations of height selected Member States. This work also assesses the European Union’s most recent initiative through a critical analysis of the proposal for a Directive on criminal sanctions for Market Abuse. Based on the conclusions drawn from its close analysis, the study takes on the challenge of analyzing whether or not the actual European public enforcement of the laws prohibiting insider trading is coherent with the theoretical law and economics recommendations, and how these enforcement practices could be improved.