Competition between evaporation and fragmentation in nuclear reactions at 15-20 AMeV beam energy

The reactions 32S+58,64Ni are studied at 14.5 AMeV. From this energy on, fragmentation begins to be a dominant process, although evaporation and fission are still present. After a selection of the collision mechanism, we show that important even-odd effects are present in the isotopic fragment distributions when the excitation energy is small. The staggering effect appears to be a universal feature of fragment production, slightly enhanced when the emission source is neutron poor. A closer look at the behavior of isotopic chains reveals that odd-even effects cannot be explained by pairing effects in the nuclear mass alone, but depend in a more complex way on the de-excitation chain.

Genotypic variation in Actinidia deliciosa fruit size and carbohydrate content

In a global and increasingly competitive fresh produce market, more attention is being given to fruit quality traits and consumer satisfaction. Kiwifruit occupies a niche position in the worldwide market, when compared to apples, oranges or bananas. It is a fruit with extraordinarily good nutritional traits, and its benefits to human health have been widely described. Until recently, international trade in kiwifruit was restricted to a single cultivar, but different types of kiwifruit are now becoming available in the market. Effective programmes of kiwifruit improvement start by considering the requirements of consumers, and recent surveys indicate that sweeter fruit with better flavour are generally preferred. There is a strong correlation between at-harvest dry matter and starch content, and soluble solid concentration and flavour when fruit are eating ripe. This suggests that carbon accumulation strongly influences the development of kiwifruit taste. The overall aim of the present study was to determine what factors affect carbon accumulation during Actinidia deliciosa berry development. One way of doing this is by comparing kiwifruit genotypes that differ greatly in their ability to accumulate dry matter in their fruit. Starch is the major component of dry matter content. It was hypothesized that genotypes were different in sink strength. Sink strength, by definition, is the effect of sink size and sink activity. Chapter 1 reviews fruit growth, kiwifruit growth and development and carbon metabolism. Chapter 2 describes the materials and methods used. Chapter 3, 4, 5 and 6 describes different types of experimental work. Chapter 7 contains the final discussions and the conclusions Three Actinidia deliciosa breeding populations were analysed in detail to confirm that observed differences in dry matter content were genetically determined. Fruit of the different genotypes differed in dry matter content mainly because of differences in starch concentrations and dry weight accumulation rates, irrespective of fruit size. More detailed experiments were therefore carried out on genotypes which varied most in fruit starch concentrations to determine why sink strengths were so different. The kiwifruit berry comprises three tissues which differ in dry matter content. It was initially hypothesised that observed differences in starch content could be due to a larger proportion of one or other of these tissues, for example, of the central core which is highest in dry matter content. The study results showed that this was not the case. Sink size, intended as cell number or cell size, was then investigated. The outer pericarp makes up about 60% of berry weight in ‘Hayward’ kiwifruit. The outer pericarp contains two types of parenchyma cells: large cells with low starch concentration, and small cells with high starch concentration. Large cell, small cell and total cell densities in the outer pericarp were shown to be not correlated with either dry matter content or fruit size but further investigation of volume proportion among cell types seemed justified. It was then shown that genotypes with fruit having higher dry matter contents also had a higher proportion of small cells. However, the higher proportion of small cell volume could only explain half of the observed differences in starch content. So, sink activity, intended as sucrose to starch metabolism, was investigated. In transiently starch storing sinks, such as tomato fruit and potato tubers, a pivotal role in carbon metabolism has been attributed to sucrose cleaving enzymes (mainly sucrose synthase and cell wall invertase) and to ADP-glucose pyrophosphorylase (the committed step in starch synthesis). Studies on tomato and potato genotypes differing in starch content or in final fruit soluble solid concentrations have demonstrated a strong link with either sucrose synthase or ADP-glucose pyrophosphorylase, at both enzyme activity and gene expression levels, depending on the case. Little is known about sucrose cleaving enzyme and ADP-glucose pyrophosphorylase isoforms. The HortResearch Actinidia EST database was then screened to identify sequences putatively encoding for sucrose synthase, invertase and ADP-glucose pyrophosphorylase isoforms and specific primers were designed. Sucrose synthase, invertase and ADP-glucose pyrophosphorylase isoform transcript levels were anlayzed throughout fruit development of a selection of four genotypes (two high dry matter and two low dry matter). High dry matter genotypes showed higher amounts of sucrose synthase transcripts (SUS1, SUS2 or both) and higher ADP-glucose pyrophosphorylase (AGPL4, large subunit 4) gene expression, mainly early in fruit development. SUS1- like gene expression has been linked with starch biosynthesis in several crop (tomato, potato and maize). An enhancement of its transcript level early in fruit development of high dry matter genotypes means that more activated glucose (UDP-glucose) is available for starch synthesis. This can be then correlated to the higher starch observed since soon after the onset of net starch accumulation. The higher expression level of AGPL4 observed in high dry matter genotypes suggests an involvement of this subunit in drive carbon flux into starch. Changes in both enzymes (SUSY and AGPse) are then responsible of higher starch concentrations. Low dry matter genotypes showed generally higher vacuolar invertase gene expression (and also enzyme activity), early in fruit development. This alternative cleavage strategy can possibly contribute to energy loss, in that invertases’ products are not adenylated, and further reactions and transport are needed to convert carbon into starch. Although these elements match well with observed differences in starch contents, other factors could be involved in carbon metabolism control. From the microarray experiment, in fact, several kinases and transcription factors have been found to be differentially expressed. Sink strength is known to be modified by application of regulators. In ‘Hayward’ kiwifruit, the synthetic cytokinin CPPU (N-(2-Chloro-4-Pyridyl)-N-Phenylurea) promotes a dramatic increase in fruit size, whereas dry matter content decreases. The behaviour of CPPU-treated ‘Hayward’ kiwifruit was similar to that of fruit from low dry matter genotypes: dry matter and starch concentrations were lower. However, the CPPU effect was strongly source limited, whereas in genotype variation it was not. Moreover, CPPU-treated fruit gene expression (at sucrose cleavage and AGPase levels) was similar to that in high dry matter genotypes. It was therefore concluded that CPPU promotes both sink size and sink activity, but at different “speeds” and this ends in the observed decrease in dry matter content and starch concentration. The lower “speed” in sink activity is probably due to a differential partitioning of activated glucose between starch storage and cell wall synthesis to sustain cell expansion. Starch is the main carbohydrate accumulated in growing Actinidia deliciosa fruit. Results obtained in the present study suggest that sucrose synthase and AGPase enzymes contribute to sucrose to starch conversion, and differences in their gene expression levels, mainly early in fruit development, strongly affect the rate at which starch is therefore accumulated. This results are interesting in that starch and Actinidia deliciosa fruit quality are tightly connected.

Mitochondrial dysfunction in hereditary optic neuropathies

MITOCHONDRIAL DYSFUNCTION IN HEREDITARY OPTIC NEUROPATHIES Mitochondrial pathologies are a heterogeneous group of clinical manifestations characterized by oxidative phosphorylation impairment. At the beginning of their recognition mitochondrial pathologies were regarded as rare disorders but indeed they are more frequent than originally thought. Due to the unique mitochondria peculiarities mitochondrial pathologies can be caused by mutations in both mitochondrial and nuclear genomes. The poor knowledge of pathologic mechanism of these disorders has not allowed a real development of the “mitochondrial medicine”, that is currently limited to symptoms mitigation. Leber hereditary optic neuropathy (LHON) was the first pathology to be linked to a point mutation in the mtDNA. The mechanism by which point mutations in mitochondrial gene encoding Complex I subunits leads to optic nerve degeneration is still unknown, although is well accepted that other genetic or environmental factors are involved in the modulation of pathology, where a pivotal role is certainly played by oxidative stress. We studied the relationship between the Ala16Val dimorphism in the mitochondrial targeting sequence of nuclear gene SOD2 and the 3460/ND1 LHON mutation. Our results show that, in control population, the heterozygous SOD2 genotype is associated to a higher activity and quantity of MnSOD, particularly with respect to Val homozygotes. Furthermore, we demonstrated that LHON patients harboring at least one Ala allele are characterized by an increased MnSOD activity with respect to relative control population. Since the ATP synthesis rate – severely reduced in LHON patients lymphocytes - is not affected by the SOD2 genotype, we concluded that SOD2 gene could modulate the pathogenicity of LHON mutations through a mechanism associated to an increase of reactive oxygen species production. Autosomal dominant optic atrophy (ADOA) is a pathology linked to mutations in nuclear gene encoding Opa1, a dynamin-related protein localized in the mitochondrial matrix. Although the clinical course is slightly different, the endpoint of ADOA is exactly the same of LHON: optic nerve degeneration with specific involvement of retinal ganglion cells. Opa1 is a relatively new protein, whose major role is the regulation of mitochondrial fusion. Mitochondrial morphology is the results of the equilibrium between two opposite force: fusion and fission, two processes that have to be finely regulated in order to preserve mitochondrial and cellular physiology. We studied fibroblasts deriving from ADOA patients characterized by a new deletion in the GTPase domain of the OPA1 gene. The biochemical characterization of ADOA and control fibroblasts has concerned the evaluation of ATP synthesis rate, mitochondrial membrane potential in different metabolic conditions and the morphological status of mitochondria. Regarding ATP synthesis rate we did not find significant differences between ADOA and control fibroblasts even though a trend toward increased reduction in ADOA samples is observed when fibroblasts are grown in absence of glucose or in the medium containing gramicidin. Furthermore, we found that also in ADOA fibroblasts membrane potential is actively maintained by proton pumping of fully functional respiratory chain complexes. Our results indicate that the mutation found in the pedigree analyzed acts primary impairing the mitochondrial fusion without affecting the energy production, supporting the notion that cell function is tightly linked to mitochondrial morphology. Mitochondrial dysfunctions are acquiring great attention because of their recognized relevance not only in aging but also in age-related pathologies including cancer, cardiovascular disease, type II diabetes, and neurodegenerative disorders. The involvement of mitochondria in such detrimental pathologies that, currently, have become so common enhances the necessity of standardization of therapeutic strategies capable of rescuing the normal mitochondrial function. In order to propose an alternative treatment for energy deficiency-disorders we tested the effect of substrates capable to stimulate the substrate-level phosphorylation on viability and energy availability in different experimental models grown under different metabolic conditions. In fibroblasts, the energy defect was achieved by culturing cells in presence of oligomycin, an inhibitor of ATP synthase complex. NARP cybrids have been used as model of mitochondrial pathology. Cell viability and ATP content have been considered as parameters to assay the capability of exogenous substrate to rescue energy failure. Our results suggest that patients suffering for some forms of ATP synthase deficiency, or characterized by a deficiency in energy production, might benefit from dietary or pharmacological treatment based on supplementation of α-ketoglutarate and aspartate.

Development discourse in Romania: from Socialism to EU Membership

With their accession to the European Union, twelve new countries - Romania among them - (re)entered the international community of international donors. In the history of development aid this can be seen as a unique event: it is for the first time in history that such a large number of countries become international donors, with such short notice and in such a particular context that sees some scholars announcing the ‘death’ of development. But in spite of what might be claimed regarding the ‘end’ of the development era, development discourse seems to be rather vigorous and in good health: it is able to extert an undeniable force of attraction over the twelve countries that, in a matter of years, have already convinced themselves of its validity and adhered to its main tenets. This thesis collects evidence for improving our understanding of this process that sees the co-optation of twelve new countries to the dominant theory and practice of development cooperation. The evidence collected seems to show that one of the tools employed by the promoters of this co-optation process is that of constructing the ‘new’ Member States as ‘new’, inexpert donors that need to learn from the ‘old’ ones. By taking a case-study approach, this thesis gathers data that suggests that conceiving of the ‘twelve’ as ‘new’ donors is both historically inaccurate and value-ladden. On one hand, Romania’s case-study illustrates how in the (socialist) past at least one in the group of the twelve was particularly conversant in the discourse of international development. On the other hand, the process of co-optation, while being presented as a knowledgeproducing process, can also be seen as an ignorance-producing procedure: Romania, along with its fellow new Member States, takes the opportunity of ‘building its capacity’ and ‘raising its awareness’ of development cooperation along the line drawn by the European Union, but at the same time it seems to un-learn and ‘lower’ its awareness of development experience in the (socialist) past. This is one possible reading of this thesis. At a different level, this thesis can also be seen as an attempt to account of almost five decades of international development discourse in one specific country – Romania – in three different socio-political contexts: the socialist years (up to the year 1989), the ‘transition years’ (from 1989 to the pre-accession years) and the membership to the European Union. In this second reading, the thesis seeks to illustrate how – contrary to widespread beliefs – before 1989 Romania’s international development discourse was particularly vivid: in the most varied national and international settings President Ceausescu unfolded an extensive discursive activity on issues pertaining to international development; generous media coverage of affairs concerning the developing countries and their fight for development was the rule rather than the exception; the political leadership wanted the Romanians not only to be familiarized with (or ‘aware of’ to use current terminology) matters of underdevelopment, but also to prove a sense of solidarity with these countries, as well as a sense of pride for the relations of ‘mutual help’ that were being built with them; finally, international development was object of academic attention and the Romanian scholars were able not only to reflect on major developments, but could also formulate critical positions towards the practices of development aid. Very little remains of all this during the transition years, while in the present those who are engaged in matters pertaining to international development do so with a view of building Romania as an EU-compliant donor.

L'accertamento dei reati di guida in stato di ebbrezza e alterazione da droghe

La tesi affronta le questioni processuali connesse alla verifica dei reati di guida in stato di ebbrezza e di alterazione da droghe. La ricerca si sviluppa in tre direzioni. La prima parte studia la disciplina tedesca. L’analisi parte dalle norme sostanziali che definiscono le fattispecie incriminatrici contemplate dall’ordinamento osservato; s’interessa, poi, degli equilibri tra gli strumenti di captazione della prova utili ai reati in discorso ed il principio nemo tenetur se detegere (l’ estensione del diritto di difesa tedesco copre anche le prove reali e non prevede obblighi di collaborazione all’alcoltest). Prosegue, infine, con l’esame delle metodologie di acquisizione della prova, dall’etilometro agli screening per le droghe, sino al prelievo ematico coattivo, indispensabile per l’accertamento penale. La seconda sezione esamina gli artt. 186 e 187 del codice della strada italiano, alla luce del principio di libertà personale e del diritto a non autoincriminarsi. Particolarmente delicati gli equilibri rispetto a quest’ultimo: l’obbligatorietà di un atto potenzialmente autoaccusatorio è evitabile solo a pena di una severa sanzione. Occorre definire se il diritto di difesa copra anche il mero facere o garantisca il solo silenzio. Se si ammette, infatti, che il nemo tenetur sia applicabile anche alle prove reali, la collaborazione obbligatoria imposta al conducente è scelta incompatibile con il diritto di difesa: la disciplina italiana presenta, dunque, profili d’illegittimità costituzionale. La terza parte riguarda le problematiche processuali poste dai controlli stradali che emergono dall’analisi della giurisprudenza. Si affrontano, così, le diverse vicende della formazione della prova: ci si interroga sull’istituto processuale cui ricondurre gli accertamenti, sulle garanzie di cui goda il guidatore durante e dopo l’espletamento dell’atto, sulle eventuali sanzioni processuali derivanti da una violazione delle predette garanzie. Si esaminano, infine, le regole di apprezzamento della prova che guidano il giudice nella delicata fase valutativa.

Attualità del divieto assoluto di procreazione medicalmente assistita eterologa in Italia e prospettive di superamento

La presente ricerca si fonda su un’attenta ed approfondita analisi della normativa vigente in Italia in materia di procreazione medicalmente assistita (P.M.A.), con particolare riferimento al divieto assoluto di P.M.A. eterologa, di cui all’art. 4, comma 3, L. 19 febbraio 2004, n. 40, consentita invece – sia pure con la previsione di limitazioni differenti – nella quasi totalità dei paesi europei. Dopo aver esaminato la “questione etica” del ricorso alle tecniche di fecondazione assistita e le normative vigenti in Europa in materia di P.M.A. eterologa, il presente lavoro analizza i profili civilistici della L. n. 40/2004 ed i conseguenti dubbi interpretativi che la normativa italiana pone in materia di fecondazione eterologa, con specifico riguardo al consenso prestato dai coniugi o conviventi, al divieto di disconoscimento di paternità e di anonimato della madre ed, infine, al diritto del nato da fecondazione eterologa di conoscere le proprie origini biologiche. Ne consegue che, in una materia che coinvolge la sfera più intima e personale della vita privata e familiare, quale quella della P.M.A., il legislatore avrebbe dovuto intervenire con misura, individuando soluzioni ragionevoli ed equilibrate nel rispetto della pluralità di etiche contrapposte ed interessi in conflitto. Attraverso una capillare analisi della recente giurisprudenza nazionale ed europea, la presente ricerca mira, dunque, a valutare possibili prospettive di superamento del divieto assoluto di P.M.A. eterologa previsto dalla L. n. 40/2004. I risultati a cui la presente indagine ha consentito di pervenire dimostrano quanto sia opportuna l’adozione in Italia di un “modello liberale”, in cui sia lecita anche la fecondazione eterologa (con la previsione di limiti e condizioni volti a tutelare primariamente il superiore interesse del nascituro), onde consentire l’adeguamento al nuovo concetto di “genitorialità” ormai prevalente e l’arresto del cd. “turismo procreativo”.

La cooperazione amministrativa tra stati membri in materia fiscale: verso una amministrazione finanziaria "europea"

L’armonizzazione fiscale è una importante sfida che l’Unione Europea si trova ad affrontare per la completa realizzazione del mercato interno. Le istituzioni comunitarie, tuttavia, non dispongono delle competenze legislative per intervenire direttamente negli ordinamenti tributari degli Stati membri. Svolgendo una analisi del contesto legislativo vigente, ed esaminando le prospettive de iure condendo della materia fiscale dell’Unione, il presente lavoro cerca di comprendere le prospettive di evoluzione del sistema, sia dal punto di vista della normativa fiscale sostanziale, che procedimentale. Mediante la disciplina elaborata a livello comunitario che regola la cooperazione amministrativa in materia fiscale, con particolare riferimento alle direttive relative allo scambio di informazioni e all’assistenza alla riscossione (dir. 2011/16/UE e dir. 2010/24/UE) si permette alle Amministrazioni degli Stati membri di avere accesso ai reciproci ordinamenti giuridici, e conoscerne i meccanismi. L’attuazione di tali norme fa sì che ciascun ordinamento abbia l’opportunità di importare le best practices implementate dagli altri Stati. L’obiettivo sarà quello di migliorare il proprio procedimento amministrativo tributario, da un lato, e di rendere più immediati gli scambi di informazione e la cooperazione alla riscossione, dall’altro. L’armonizzazione fiscale all’interno dell’Unione verrebbe perseguita, anziché mediante un intervento a livello europeo, attraverso un coordinamento “dal basso” degli ordinamenti fiscali, realizzato attraverso l’attività di cooperazione delle amministrazioni che opereranno su un substrato di regole condivise. La maggiore apertura delle amministrazioni fiscali dei Paesi membri e la maggiore spontaneità degli scambi di informazioni, ha una efficacia deterrente di fenomeni di evasione e di sottrazione di imposta posti in essere al fine di avvantaggiarsi delle differenze dei sistemi impositivi dei vari paesi. Nel lungo periodo ciò porterà verosimilmente, gli Stati membri a livellare i sistemi impositivi, dal momento che i medesimi non avranno più interesse ad utilizzare la leva fiscale per generare una concorrenza tra gli ordinamenti.

Advanced aspects of radiation protection in the use of particle accelerators in the medical field

In this work, the well-known MC code FLUKA was used to simulate the GE PETrace cyclotron (16.5 MeV) installed at “S. Orsola-Malpighi” University Hospital (Bologna, IT) and routinely used in the production of positron emitting radionuclides. Simulations yielded estimates of various quantities of interest, including: the effective dose distribution around the equipment; the effective number of neutron produced per incident proton and their spectral distribution; the activation of the structure of the cyclotron and the vault walls; the activation of the ambient air, in particular the production of 41Ar, the assessment of the saturation yield of radionuclides used in nuclear medicine. The simulations were validated against experimental measurements in terms of physical and transport parameters to be used at the energy range of interest in the medical field. The validated model was also extensively used in several practical applications uncluding the direct cyclotron production of non-standard radionuclides such as 99mTc, the production of medical radionuclides at TRIUMF (Vancouver, CA) TR13 cyclotron (13 MeV), the complete design of the new PET facility of “Sacro Cuore – Don Calabria” Hospital (Negrar, IT), including the ACSI TR19 (19 MeV) cyclotron, the dose field around the energy selection system (degrader) of a proton therapy cyclotron, the design of plug-doors for a new cyclotron facility, in which a 70 MeV cyclotron will be installed, and the partial decommissioning of a PET facility, including the replacement of a Scanditronix MC17 cyclotron with a new TR19 cyclotron.