292 resultados para Dell, Richard


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Oxidative DNA damages determine the activation of cell repair processes. These processes originate repair products, including the most studied one, 8-hydroxy-2’-deoxyguanosine (8-OH-dG). Several analytical techniques have been applied to measure urinary 8-OH-dG, but a discrepancy in basal urinary 8-OH-dG levels has been noted when comparing chromatographic techniques with immunoenzymatic assays (ELISA). Our laboratory has developed a fully validated, liquid chromatography-tandem mass spectrometry method presenting high sensitivity and specificity, which has participated in an inter-laboratory validation of assays for the measurement of urinary 8-OH-dG (ESCULA project). Mass Spectrometric techniques showed more accuracy and specificity than immunoenzymatic methods. Human spot urine samples were analyzed in order to investigate the possibility to correct urinary lesion measurements for creatinine and to evaluate the intra- and inter-day variability of 8-OH-dG excretion in urine. Our results confirm the opportunity to delve into these issues. Finally, we measured urinary 8-OH-dG in workers exposed to antineoplastic drugs and in a group of unexposed subjects to evaluate the relationship between occupational exposure and oxidative damage related to the internal dose. We found higher levels of 8-OH-dG in exposed nurses, but, as compared to the non-exposed subjects, the difference was not statistically significant, probably do to the very low level of exposure. The scientific literature is rapidly developing on the topic of DNA damage and related repair capacity. Nevertheless, further studies are needed to achieve a better understanding of the sources of DNA lesions in urine and their significance, both in clinical and occupational medicine.

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The Ph.D. dissertation analyses the reasons for which political actors (governments, legislatures and political parties) decide consciously to give away a source of power by increasing the political significance of the courts. It focuses on a single case of particular significance: the passage of the Constitutional Reform Act 2005 in the United Kingdom. This Act has deeply changed the governance and the organization of the English judicial system, has provided a much clearer separation of powers and a stronger independence of the judiciary from the executive and the legislative. What’s more, this strengthening of the judicial independence has been decided in a period in which the political role of the English judges was evidently increasing. I argue that the reform can be interpreted as a «paradigm shift» (Hall 1993), that has changed the way in which the judicial power is considered. The most diffused conceptions in the sub-system of the English judicial policies are shifted, and a new paradigm has become dominant. The new paradigm includes: (i) stronger separation of powers, (ii) collective (as well as individual) conception of the independence of the judiciary, (iii) reduction of the political accountability of the judges, (iv) formalization of the guarantees of judicial independence, (v) principle-driven (instead of pragmatic) approach to the reforms, and (vi) transformation of a non-codified constitution in a codified one. Judicialization through political decisions represent an important, but not fully explored, field of research. The literature, in particular, has focused on factors unable to explain the English case: the competitiveness of the party system (Ramseyer 1994), the political uncertainty at the time of constitutional design (Ginsburg 2003), the cultural divisions within the polity (Hirschl 2004), federal institutions and division of powers (Shapiro 2002). All these contributes link the decision to enhance the political relevance of the judges to some kind of diffusion of political power. In the contemporary England, characterized by a relative high concentration of power in the government, the reasons for such a reform should be located elsewhere. I argue that the Constitutional Reform Act 2005 can be interpreted as a result of three different kinds of reasons: (i) the social and demographical transformations of the English judiciary, which have made inefficient most of the precedent mechanism of governance, (ii) the role played by the judges in the policy process and (iii) the cognitive and normative influences originated from the European context, as a consequence of the membership of the United Kingdom to the European Union and the Council of Europe. My thesis is that only a full analysis of all these three aspects can explain the decision to reform the judicial system and the content of the Constitutional Reform Act 2005. Only the cultural influences come from the European legal complex, above all, can explain the paradigm shift previously described.

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Il lavoro di ricerca tenta di inquadrare sotto nuove prospettive una problematica ormai classica all’interno della semiotica della pubblicità: l’analisi dello spot. I punti chiave del lavoro – e la pretesa di una certa differenza rispetto a lavori con oggetti affini – consistono sostanzialmente in tre aspetti. Innanzitutto, vi è un ritorno alle origini flochiane nella misura in cui non solo il contesto complessivo e le finalità che la ricerca si propone sono fortemente ancorati all’interno di obiettivi di marketing, ma tutto lo studio nella sua interezza nasce dal dialogo concreto tra metodologia di analisi semiotica e prassi concreta all’interno degli istituti di ricerca di mercato. La tesi non presenta quindi una collezione di analisi di testi pubblicitari condotte in modo autoriferito, quanto piuttosto di “messe alla prova” della metodologia, funzionali alla definizione di disegni di ricerca per la marketing research. Questo comporta un dialogo piuttosto stretto con metodologie affini (sociologia qualitativa e quantitativa, psicologia motivazionale, ecc.) nella convinzione che la priorità accordata all’oggetto di analisi sia sovraordinata rispetto all’ortodossia degli strumenti metodologici. In definitiva, lo spot è sempre e comunque analizzato all’interno di una prospettiva brand-centrica che ha ben in mente la semiotica della situazione di consumo rispetto alla quale lo spot agisce da leva di valorizzazione per l’acquisto. In secondo luogo, gli oggetti analizzati sono piuttosto vari e differenziati: non solo lo spot nella sua versione audiovisiva definitiva (il “girato”), ma anche storyboard, animatic, concept (di prodotto e di comunicazione). La prospettiva generativa greimasiana va a innestarsi su problematiche legate (anche) alla genesi dello spot, alla sua progettazione e riprogettazione/ottimizzazione. La tesi mostra quindi come una semiotica per le consulenze di marketing si diriga sul proprio oggetto ponendogli domande ben circoscritte e finalizzate a un obiettivo specifico, sostanzialmente derivato dal brief contenente le intenzioni comunicazionali del cliente-azienda. Infine, pur rimanendo all’interno di una teoria semiotica generativa (sostanzialmente greimasiana e post greimasiana), la ricerca adotta una prospettiva intrinsecamente multidisciplinare che se da un lato guarda a problematiche legate al marketing, al branding e alla comunicazione pubblicitaria e d’impresa tout court, dall’altro ritorna alle teorie dell’audiovisivo, mostrando affinità e differenze rispetto a forme audiovisive standard (il “film”) e a mutuazioni da nuove estetiche (la neotelevisione, il videoclip, ecc). La tesi si mostra solidamente convinta del fatto che per parlare di efficacia discorsiva sia imprescindibile approfondire le tematiche riguardanti il sincretismo espressivo e le specifiche modalità di manifestazione stilistica. In questo contesto, il lavoro si compone di quattro grandi aree tematiche. Dopo una breve introduzione sull’attualità del tema “spot” e sulla prospettiva analiticometodologica adottata (§ 1.), nel secondo capitolo si assume teoreticamente che i contenuti dello spot derivino da una specifica (e di volta in volta diversa) creolizzazione tra domini tematici derivanti dalla marca, dal prodotto (inteso tanto come concept di prodotto, quanto come prodotto già “vestito” di una confezione) e dalle tendenze socioculturali. Le tre dimensioni vengono valutate in relazione all’opposizione tra heritage, cioè continuità rispetto al passato e ai concorrenti e vision, cioè discontinuità rispetto alla propria storia comunicazionale e a quella dei concorrenti. Si esplorano inoltre altri fattori come il testimonial-endorser che, in quanto elemento già intrinsecamente foriero di elementi di valorizzazione, va a influire in modo rilevante sul complesso tematico e assiologico della pubblicità. Essendo la sezione della tesi che prende in considerazione il piano specificatamente contenutistico dello spot, questa parte diventa quindi anche l’occasione per ritornare sul modello delle assiologie del consumo di Jean-Marie Floch, approntando alcune critiche e difendendo invece un modello che – secondo la prospettiva qui esposta – contiene punti di attualità ineludibili rispetto a schematizzazioni che gli sono successive e in qualche modo debitrici. Segue una sezione (§ 3.) specificatamente dedicata allo svolgimento e dis-implicazione del sincretismo audiovisivo e quindi – specularmente alla precedente, dedicata alle forme e sostanze del contenuto – si concentra sulle dinamiche espressive. Lo spot viene quindi analizzato in quanto “forma testuale” dotata di alcune specificità, tra cui in primis la brevità. Inoltre vengono approfondite le problematiche legate all’apporto di ciascuna specifica sostanza: il rapporto tra visivo e sonoro, lo schermo e la sua multiprospetticità sempre più evidente, il “lavoro” di punteggiatura della musica, ecc. E su tutto il concetto dominante di montaggio, intrinsecamente unito a quello di ritmo. Il quarto capitolo ritorna in modo approfondito sul rapporto tra semiotica e ricerca di mercato, analizzando sia i rapporti di reciproca conoscenza (o non conoscenza), sia i nuovi spazi di intervento dell’analisi semiotica. Dopo aver argomentato contro un certo scetticismo circa l’utilità pragmatica dell’analisi semiotica, lo studio prende in esame i tradizionali modelli di valutazione e misurazione dell’efficacia pubblicitaria (pre- e post- test) cercando di semiotizzarne il portato. Ne consegue la proposta di disegni di ricerca semiotici modulari: integrabili tra loro e configurabili all’interno di progetti semio-quali-quantitativi. Dopo aver ridefinito le possibilità di un’indagine semiotica sui parametri di efficacia discorsiva, si procede con l’analisi di un caso concreto (§ 5.): dato uno spot che si è dimostrato efficace agli occhi dell’azienda committente, quali possono essere i modi per replicarne i fattori di successo? E come spiegare invece quelli di insuccesso delle campagne successive che – almeno teoricamente – erano pensate per capitalizzare l’efficacia della prima? Non si tratta quindi di una semiotica ingenuamente chiamata a “misurare” l’efficacia pubblicitaria, che evidentemente la marketing research analizza con strumenti quantitativi assodati e fondati su paradigmi di registrazione di determinati parametri sul consumatore (ricordo spontaneo e sollecitato, immagine di marca risultante nella mente di user e prospect consumer, intenzione d’acquisto stimolata). Piuttosto l’intervento qui esposto si preoccupa più funzionalmente a spiegare quali elementi espressivi, discorsivi, narrativi, siano stati responsabili (e quindi prospetticamente potranno condizionare in positivo o in negativo in futuro) la ricezione dello spot. L’analisi evidenzia come elementi apparentemente minimali, ancorati a differenti livelli di pertinenza siano in grado di determinare una notevole diversità negli effetti di senso. Si tratta quindi di un problema di mancata coerenza tra intenzioni comunicative e testo pubblicitario effettivamente realizzato. La risoluzione di tali questioni pragmatiche conduce ad approfondimenti teoricometodologici su alcuni versanti particolarmente interessanti. In primo luogo, ci si interroga sull’apporto della dimensione passionale nella costruzione dell’efficacia e nel coinvolgimento dello spettatore/consumatore. Inoltre – e qui risiede uno dei punti di maggior sintesi del lavoro di tesi – si intraprende una proficua discussione dei modelli di tipizzazione dei generi pubblicitari, intesi come forme discorsive. Si fanno quindi dialogare modelli diversi ma in qualche misura coestensivi e sovrapponibili come quelli di Jean Marie Floch, Guido Ferraro, Cosetta Saba e Chiara Giaccardi. Si perviene così alla costruzione di un nuovo modello sintetico, idealmente onnipervasivo e trasversale alle prospettive analizzate.

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Biomasses and their possible use as energy resource are of great interest today, and the general problem of energy resources as well. In the present study the key questions of the convenience, from both energy and economy standpoints, have been addressed without any bias: the problem has been handled starting from “philosophical” bases disregarding any pre-settled ideology or political trend, but simply using mathematical approaches as logical tools for defining balances in a right way. In this context quantitative indexes such as LCA and EROEI have been widely used, together with multicriteria methods (such as ELECTRE) as decision supporting tools. This approach permits to remove mythologies, such as the unrealistic concept of clean energy, or the strange idea of biomasses as a magic to solve every thing in the field of the energy. As a consequence the present study aims to find any relevant aspect potentially useful for the society, looking at any possible source of energy without prejudices but without unrealistic expectations too. For what concerns biomasses, we studied in great details four very different cases of study, in order to have a scenario as various as much we can. A relevant result is the need to use biomasses together with other more efficient sources, especially recovering by-products from silviculture activities: but attention should be paid to the transportation and environmental costs. Another relevant result is the very difficult possibility of reliable evaluation of dedicated cultures as sources for “biomasses for energy”: the problem has to be carefully evaluated case-by-case, because what seems useful in a context, becomes totally disruptive in another one. In any case the concept itself of convenience is not well defined at a level of macrosystem: it seems more appropriate to limit this very concept at a level of microsystem, considering that what sounds fine in a limited well defined microsystem may cause great damage in another slightly different, or even very similar, microsystem. This approach seems the right way to solve the controversy about the concept of convenience.

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Background: Almost 10-15% of patients with active Ulcerative Colitis are refractory to conventional therapy. Infliximab is a treatment of proven efficacy in this group of patients. Aims: To evaluate the role of Inliximab in inducing and maintaining remission in patients with chronically active moderate-severe Ulcerative Colitis. Materials and methods: 53 patients were enrolled, 47 patients entered the study and were treated with a dose of 5 mg/kg. The remission was evaluated through endoscopy and clinical criteria. (Mayo Score). The primary endpoint were clinical and endoscopic remission in moderate-severe Ulcerative Colitis refractory to standard therapy, the secondary out point was the maintenance of remission in the long period. Results: 47 patients started the study, 43 completed the study, 4 dropped out for worsening disease or adverse events; 27 patients were treated with 3 infusions, 9 patients with 4 infusions, 7 patients with > o = 5 infusions. 34 /47 patients (72.3%) were responders 12 (25.5%) improved their symptoms, 22 ( 46.8%) were in remission after the treatment. Among the responders, 21/34 (61.8%) stopped the steroid therapy after 3 infusions, the others reduced the dose or maintained just topic therapy. 13/47 patients (27.7%) were non responders (p <0.001). After 3 months all 22 patients which had reached remission maintained low Mayo Score; 10/12 (83.3%) patients with clinical response maintained their low score, 2 relapsed . Conclusions: Infliximab is a valid therapy for the treatment of Ulcerative Colitis and can avoid surgery in selected patients.

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A multidisciplinary study was carried out on the Late Quaternary-Holocene subsurface deposits of two Mediterranean coastal areas: Arno coastal plain (Northern Tyrrhenian Sea) and Modern Po Delta (Northern Adriatic Sea). Detailed facies analyses, including sedimentological and micropalaeontological (benthic foraminifers and ostracods) investigations, were performed on nine continuously-cored boreholes of variable depth (ca. from 30 meters to100 meters). Six cores were located in the Arno coastal plain and three cores in the Modern Po Delta. To provide an accurate chronological framework, twenty-four organic-rich samples were collected along the fossil successions for radiocarbon dating (AMS 14C). In order to reconstruct the depositional and palaeoenvironmental evolution of the study areas, core data were combined with selected well logs, provided by local companies, along several stratigraphic sections. These sections revealed the presence of a transgressive-regressive (T-R) sequence, composing of continental, coastal and shallow-marine deposits dated to the Late Pleistocene-Holocene period, beneath the Arno coastal plain and the Modern Po Delta. Above the alluvial deposits attributed to the last glacial period, the post-glacial transgressive succession (TST) consists of back-barrier, transgressive barrier and inner shelf deposits. Peak of transgression (MFS) took place around the Late-Middle Holocene transition and was identified by subtle micropalaeontological indicators within undifferentiated fine-grained deposits. Upward a thick prograding succession (HST) records the turnaround to regressive conditions that led to a rapid delta progradation in both study areas. Particularly, the outbuilding of modern-age Po Delta coincides with mud-belt formation during the late HST (ca. 600 cal yr BP), as evidenced by a fossil microfauna similar to the foraminiferal assemblage observed in the present Northern Adriatic mud-belt. A complex interaction between allocyclic and autocyclic factors controlled facies evolution during the highstand period. The presence of local parameters and the absence of a predominant factor prevent from discerning or quantifying consequences of the complex relationships between climate and deltaic evolution. On the contrary transgressive sedimentation seems to be mainly controlled by two allocyclic key factors, sea-level rise and climate variability, that minimized the effects of local parameters on coastal palaeoenvironments. TST depositional architecture recorded in both study areas reflects a well-known millennial-scale variability of sea-level rising trend and climate during the Late glacial-Holocene period. Repeated phases of backswamp development and infilling by crevasse processes (parasequences) were recorded in the subsurface of Modern Po Delta during the early stages of transgression (ca. 11,000-9,500 cal yr BP). In the Arno coastal plain the presence of a deep-incised valley system, probably formed at OSI 3/2 transition, led to the development of a thick (ca. 35-40 m) transgressive succession composed of coastal plain, bay-head delta and estuarine deposits dated to the Last glacial-Early Holocene period. Within the transgressive valley fill sequence, high-resolution facies analyses allowed the identification and lateral tracing of three parasequences of millennial duration. The parasequences, ca. 8-12 meters thick, are bounded by flooding surfaces and show a typical internal shallowing-upward trend evidenced by subtle micropalaeontological investigations. The vertical stacking pattern of parasequences shows a close affinity with the step-like sea-level rising trend occurred between 14,000-8,000 cal years BP. Episodes of rapid sea-level rise and subsequent stillstand phases were paralleled by changes in climatic conditions, as suggested by pollen analyses performed on a core drilled in the proximal section of the Arno palaeovalley (pollen analyses performed by Dr. Marianna Ricci Lucchi). Rapid shifts to warmer climate conditions accompanied episodes of rapid sea-level rise, in contrast stillstand phases occurred during temporary colder climate conditions. For the first time the palaeoclimatic signature of high frequency depositional cycles is clearly documented. Moreover, two of the three "regressive" pulsations, recorded at the top of parasequences by episodes of partial estuary infilling in the proximal and central portions of Arno palaeovalley, may be correlated with the most important cold events of the post-glacial period: Younger Dryas and 8,200 cal yr BP event. The stratigraphic and palaeoclimatic data of Arno coastal plain and Po Delta were compared with those reported for the most important deltaic and coastal systems in the worldwide literature. The depositional architecture of transgressive successions reflects the strong influence of millennial-scale eustatic and climatic variability on worldwide coastal sedimentation during the Late glacial-Holocene period (ca. 14,000-7,000 cal yr BP). The most complete and accurate record of high-frequency eustatic and climatic events are usually found within the transgressive succession of very high accommodation settings, such as incised-valley systems where exceptionally thick packages of Late glacial-Early Holocene deposits are preserved.

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Objectives: Human Herpesvirus 8 (HHV-8) is the etiological agent of Kaposi’s Sarcoma (KS) and it is also associated with two B cell lymphoproliferative diseases: primary effusion lymphoma (PEL), and the plasmablastic form of multicentric Castelman’s disease (MCD). HHV-8 establishes persistent infection in the host with tropism for multiple cell types. In KS patients, the virus is found in tumor-spindle cells, peripheral blood monocytes, endothelial progenitor circulating cells, T and B lymphocytes. Peripheral B cells represent one of the major virus reservoir, but the consequences of HHV-8 infection of these cells have been poorly characterized. Therefore, in this study the frequency, the immunophenotypic profile and the functional activity of different peripheral B cell subsets in patients with classic KS (cKS) was analysed in order to identify potential alterations of these cells. The classic variant of KS is ideal to perform such studies, as it lacks confounding factors such as HIV or EBV infection and immunosuppression. Methods: Whole-blood samples from patients with the classical form of KS (cKS) (n=62) and healthy age and sex-matched seronegative controls (HSN) (n=43) were analyzed by multiparametric flow-cytometry to determine the frequency of B cells and their subpopulations, as well as their surface expression of immunoglobulins and activation markers. Results: The frequency of circulating B cells was significantly higher in cKS patients than in controls. In particular, the analysis of the B cell subsets revealed a higher frequency of naïve B cells (CD19+CD27-), among which transitional CD19+CD38highCD5+ and pre-naïve (CD27-CD38intCD5+ ) B cells demonstrated an expansion. Memory B cells (CD19+CD27+) did not differ between the two study groups, except from a higher frequency of CD19+CD27+IgM+IgD+ B cells, the typical phenotype of marginal zone (MZ) B cells, in cKS patients. The characterization of membrane surface activation markers showed lower levels of the activation marker HLA-DR only on CD27- B cells, while CD80 and CD86 were less represented in all the the B cells from cKS patients. Moreover, B cells from cKS patients were smaller and with less granules than the ones from controls. Conclusion: Taken together, these results clearly indicate that circulating B cells are altered in patients with cKS, showing an expansion of the immature phenotypes. These B cell alterations may be due to an indirect viral effect rather than to a direct one: the cytokines expressed in the microenvironment typical of cKS may cause a faster release of immature cells from the bone marrow and a lower grade of peripheral differentiation, as already suggested for other chronic viral infections such as HIV and HCV. Further studies will be necessary to understand how these alterations contribute to the pathogenesis of KS and, eventually, to the different clinical evolution of the disease.

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The main aim of this thesis is strongly interdisciplinary: it involves and presumes a knowledge on Neurophysiology, to understand the mechanisms that undergo the studied phenomena, a knowledge and experience on Electronics, necessary during the hardware experimental set-up to acquire neuronal data, on Informatics and programming to write the code necessary to control the behaviours of the subjects during experiments and the visual presentation of stimuli. At last, neuronal and statistical models should be well known to help in interpreting data. The project started with an accurate bibliographic research: until now the mechanism of perception of heading (or direction of motion) are still poorly known. The main interest is to understand how the integration of visual information relative to our motion with eye position information happens. To investigate the cortical response to visual stimuli in motion and the integration with eye position, we decided to study an animal model, using Optic Flow expansion and contraction as visual stimuli. In the first chapter of the thesis, the basic aims of the research project are presented, together with the reasons why it’s interesting and important to study perception of motion. Moreover, this chapter describes the methods my research group thought to be more adequate to contribute to scientific community and underlines my personal contribute to the project. The second chapter presents an overview on useful knowledge to follow the main part of the thesis: it starts with a brief introduction on central nervous system, on cortical functions, then it presents more deeply associations areas, which are the main target of our study. Furthermore, it tries to explain why studies on animal models are necessary to understand mechanism at a cellular level, that could not be addressed on any other way. In the second part of the chapter, basics on electrophysiology and cellular communication are presented, together with traditional neuronal data analysis methods. The third chapter is intended to be a helpful resource for future works in the laboratory: it presents the hardware used for experimental sessions, how to control animal behaviour during the experiments by means of C routines and a software, and how to present visual stimuli on a screen. The forth chapter is the main core of the research project and the thesis. In the methods, experimental paradigms, visual stimuli and data analysis are presented. In the results, cellular response of area PEc to visual stimuli in motion combined with different eye positions are shown. In brief, this study led to the identification of different cellular behaviour in relation to focus of expansion (the direction of motion given by the optic flow pattern) and eye position. The originality and importance of the results are pointed out in the conclusions: this is the first study aimed to investigate perception of motion in this particular cortical area. In the last paragraph, a neuronal network model is presented: the aim is simulating cellular pre-saccadic and post-saccadic response of neuron in area PEc, during eye movement tasks. The same data presented in chapter four, are further analysed in chapter fifth. The analysis started from the observation of the neuronal responses during 1s time period in which the visual stimulation was the same. It was clear that cells activities showed oscillations in time, that had been neglected by the previous analysis based on mean firing frequency. Results distinguished two cellular behaviour by their response characteristics: some neurons showed oscillations that changed depending on eye and optic flow position, while others kept the same oscillations characteristics independent of the stimulus. The last chapter discusses the results of the research project, comments the originality and interdisciplinary of the study and proposes some future developments.