976 resultados para Vanni (Francesco)
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A combined strategy based on the computation of absorption energies, using the ZINDO/S semiempirical method, for a statistically relevant number of thermally sampled configurations extracted from QM/MM trajectories is used to establish a one-to-one correspondence between the structures of the different early intermediates (dark, batho, BSI, lumi) involved in the initial steps of the rhodopsin photoactivation mechanism and their optical spectra. A systematic analysis of the results based on a correlation-based feature selection algorithm shows that the origin of the color shifts among these intermediates can be mainly ascribed to alterations in intrinsic properties of the chromophore structure, which are tuned by several residues located in the protein binding pocket. In addition to the expected electrostatic and dipolar effects caused by the charged residues (Glu113, Glu181) and to strong hydrogen bonding with Glu113, other interactions such as π-stacking with Ala117 and Thr118 backbone atoms, van der Waals contacts with Gly114 and Ala292, and CH/π weak interactions with Tyr268, Ala117, Thr118, and Ser186 side chains are found to make non-negligible contributions to the modulation of the color tuning among the different rhodopsin photointermediates.
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Référence bibliographique : Weigert, 570
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Référence bibliographique : Weigert, 571
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Référence bibliographique : Weigert, 568
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BACKGROUND & AIMS: Steatosis is a prominent feature of hepatitis C, especially in patients infected with genotype 3. The analysis of genetic polymorphisms influencing steatosis in chronic hepatitis C has been limited by the studies' small sample size, and important single nucleotide polymorphisms (SNPs), such as those in the patatin-like phospholipase family 3 protein (PNPLA3), were never evaluated. METHODS: We analyzed the role of SNPs, from 19 systematically selected candidate genes, on steatosis in 626 Caucasian hepatitis C virus (HCV) infected patients. SNPs were extracted from a genome-wide association-generated dataset. Associations of alleles with the presence and/or different severity of steatosis were evaluated by univariate and multivariate logistic regression, accounting for all relevant covariates. RESULTS: The risk of steatosis was increased by carriage of I148M in PNPLA3, but only in patients with HCV genotypes non-3 (odds ratio [OR]=1.9, 95% confidence interval [CI]=1.6-2.3, p<0.001) and similar, albeit weaker associations were found for SNPs in peroxisome proliferator-activated receptor-γ (PPARG) and interleukin-28B (IL28B). Carriage of a SNP in the microsomal triglyceride transfer protein (MTTP) increased the risk of steatosis, but only in patients with HCV genotype 3 (rs1800803, OR=3.4, 95% CI=2.4-4.9, p=0.001). CONCLUSIONS: The rs738409 SNP in PNPLA3 is associated with an increased risk of steatosis in patients infected with HCV genotypes non-3. Host genes affect steatosis depending on the infecting HCV genotype, suggesting their interaction with viral factors.
Life Markers of the transition to adulthood. A first investigation of Traces LifeCourse Events data.
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The field of mobility studies examines social phenomena through the lens of movement. In this perspective, societies are regarded as being constantly reconfigured as they are shaped by a series of mobile entities (capital, people, information). This book engages critically with many of the claims and challenges of mobility studies by providing empirically rich reports of mobilities and their limitations. Instead of assuming a seamless world of flows, the volume foregrounds questions of power, inequality, and moorings as integral to the movement of capital, goods, images, practices, or people. It brings together the work of several internationally renowned scholars, who engage with these movements at critical sites. This is the first book to provide a critical and interdisciplinary view of mobilities covering a broad range of issues rather than a single domain. The chapters deal with current and important issues, such as organ transplants, illegal migrations, urban globalization, international policies of higher education institutions, and scientific diasporas. As a whole, the book provides new insights into how power relations shape mobilities and societies.
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Reflexionem amb en Frato és un projecte d'innovació que s'ha portat a terme a la Facultat de Formació del Professorat de la Universitat de Barcelona, en l'assignatura de Didàctica de la llengua IIdels estudis de Mestre en l'especialitat d'Educació Infantil, durant quatre cursos lectius en horari de matí i tarda. La tasca forma part d'un projecte del grup d'innovació docent consolidat de la Universitat de Barcelona GIDC-DLL, al qual pertanyen les dues professores. La innovació té la voluntat d'iniciar la transformació de l'ensenyament i aprenentatge a la universitat en el marc de l'Espai Europeu d'Educació Superior com a context general i, més específicament, dins la matèria de Didàctica de la llengua II delsestudis de Mestre en l'especialitat d'Educació Infantil. El projecte neix arran de la publicació del llibreFrato: 40 anys amb ulls d'infant, de Francesco Tonucci, a partir del qual es planteja una seqüènciaformativa competencial per als estudiants fàcilment transferible i amb valoracions molts positives.
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The accumulation of the widely-used antibacterial and antifungal compound triclosan (TCS) in freshwaters raises concerns about the impact of this harmful chemical on the biofilms that are the dominant life style of microorganisms in aquatic systems. However, investigations to-date rarely go beyond effects at the cellular, physiological or morphological level. The present paper focuses on bacterial biofilms addressing the possible chemical impairment of their functionality, while also examining their substratum stabilization potential as one example of an important ecosystem service. The development of a bacterial assemblage of natural composition – isolated from sediments of the Eden Estuary (Scotland, UK) – on non-cohesive glass beads (,63 mm) and exposed to a range of triclosan concentrations (control, 2 – 100 mg L21) was monitored over time by Magnetic Particle Induction (MagPI). In parallel, bacterial cell numbers, division rate, community composition (DGGE) and EPS (extracellular polymeric substances: carbohydrates and proteins) secretion were determined. While the triclosan exposure did not prevent bacterial settlement, biofilm development was increasingly inhibited by increasing TCS levels. The surface binding capacity (MagPI) of the assemblages was positively correlated to the microbial secreted EPS matrix. The EPS concentrations and composition (quantity and quality) were closely linked to bacterial growth, which was affected by enhanced TCS exposure. Furthermore, TCS induced significant changes in bacterial community composition as well as a significant decrease in bacterial diversity. The impairment of the stabilization potential of bacterial biofilm under even low, environmentally relevant TCS levels is of concern since the resistance of sediments to erosive forces has large implications for the dynamics of sediments and associated pollutant dispersal. In addition, the surface adhesive capacity of the biofilm acts as a sensitive measure of ecosystem effects
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Role reversal, whereby a child attempts to meet her parent's adult needs for parenting, intimacy, or companionship, has been identified as a risk factor for developmental disturbances. It has been defined from diverse perspectives as a child attachment strategy, a parent - toddler relational disturbance, and a boundary disturbance between parents and child. The recently discovered infant's triangular capacity, namely the sharing of her attention and affects with both parents, allows one to analyse the infant's contribution to early family dynamics. Role reversal was detected in 4 out of 45 father - mother - infant interactions observed in trilogue play from pregnancy to toddlerhood. The developmental trajectories towards role reversal are explored by means of case analyses. Results are compared with cases of problematic triangulation encountered in the same sample. In role reversal, family interactions are rigidly organized around a "two against one" coalition, whereby the normative hierarchy between parents and child is reversed. The child's triangular capacity is overactivated, controlling the tension between her parents by provocation - animation strategies
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Although the performance of the Swiss health system is high, one out of ten patients in general practitioner's (GP) office declares having foregone care in the previous twelve months for economic reasons. Reasons for foregoing care are several and include a lack of knowledge of existing social aids in getting health insurance, unavailability of GPs and long waiting lists for various types of care. Although long term knowledge of patients or a psychosocial history of deprivation or poverty may help identify individuals at risk of foregoing care, many may remain undetected. We propose then a few instruments to help GPs to identify, in a simple and structured approach, patients at risk of forgoing care for economic reasons; these patients are frequently deprived and sometimes poor.
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By means of computer simulations and solution of the equations of the mode coupling theory (MCT),we investigate the role of the intramolecular barriers on several dynamic aspects of nonentangled polymers. The investigated dynamic range extends from the caging regime characteristic of glass-formers to the relaxation of the chain Rouse modes. We review our recent work on this question,provide new results, and critically discuss the limitations of the theory. Solutions of the MCT for the structural relaxation reproduce qualitative trends of simulations for weak and moderate barriers. However, a progressive discrepancy is revealed as the limit of stiff chains is approached. This dis-agreement does not seem related with dynamic heterogeneities, which indeed are not enhanced by increasing barrier strength. It is not connected either with the breakdown of the convolution approximation for three-point static correlations, which retains its validity for stiff chains. These findings suggest the need of an improvement of the MCT equations for polymer melts. Concerning the relaxation of the chain degrees of freedom, MCT provides a microscopic basis for time scales from chain reorientation down to the caging regime. It rationalizes, from first principles, the observed deviations from the Rouse model on increasing the barrier strength. These include anomalous scaling of relaxation times, long-time plateaux, and nonmonotonous wavelength dependence of the mode correlators.