115 research outputs found

    Modeling meander morphodynamics over self-formed heterogeneous floodplains

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    This work addresses the signatures embedded in the planform geometry of meandering rivers consequent to the formation of floodplain heterogeneities as the river bends migrate. Two geomorphic features are specifically considered: scroll bars produced by lateral accretion of point bars at convex banks and oxbow lake fills consequent to neck cutoffs. The sedimentary architecture of these geomorphic units depends on the type and amount of sediment, and controls bank erodibility as the river impinges on them, favoring or contrasting the river migration. The geometry of numerically generated planforms obtained for different scenarios of floodplain heterogeneity is compared to that of natural meandering paths. Half meander metrics and spatial distribution of channel curvatures are used to disclose the complexity embedded in meandering geometry. Fourier Analysis, Principal Component Analysis, Singular Spectrum Analysis and Multivariate Singular Spectrum Analysis are used to emphasize the subtle but crucial differences which may emerge between apparently similar configurations. A closer similarity between observed and simulated planforms is attained when fully coupling flow and sediment dynamics (fully-coupled models) and when considering self-formed heterogeneities that are less erodible than the surrounding floodplain

    Social Interaction-Aware Dynamical Models and Decision Making for Autonomous Vehicles

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    Interaction-aware Autonomous Driving (IAAD) is a rapidly growing field of research that focuses on the development of autonomous vehicles (AVs) that are capable of interacting safely and efficiently with human road users. This is a challenging task, as it requires the autonomous vehicle to be able to understand and predict the behaviour of human road users. In this literature review, the current state of IAAD research is surveyed in this work. Commencing with an examination of terminology, attention is drawn to challenges and existing models employed for modelling the behaviour of drivers and pedestrians. Next, a comprehensive review is conducted on various techniques proposed for interaction modelling, encompassing cognitive methods, machine learning approaches, and game-theoretic methods. The conclusion is reached through a discussion of potential advantages and risks associated with IAAD, along with the illumination of pivotal research inquiries necessitating future exploration

    The utility of network analysis in the context of Indigenous Australian oral health literacy

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    The study of oral health literacy (OHL) is likely to gain new and interesting insights with the use of network analysis, a powerful analytical tool that allows the investigation of complex systems of relationships. Our aim was to investigate the relationships between oral health literacy and oral health-related factors in a sample of Indigenous Australian adults using a network analysis approach.Gustavo Hermes Soares, Pedro Henrique Ribeiro Santiago, Edgard Michel-Crosato, Lisa Jamieso

    Long-term effects of the new direct antiviral agents (DAAs) therapy for HCV-related mixed cryoglobulinaemia without renal involvement: a multicentre open-label study

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    Objective. To investigate the long-term effects and safety of new direct antiviral agents (DAAs) in patients with hepatitis C virus (HCV)-related mixed cryoglobulinaemia (MC) without renal involvement.Methods. The study enrolled 22 consecutive patients, 19 received sofosbuvir-based regimen and three patients received other DAAs, individually tailored according to latest guidelines. As of December 2016, the median length of follow-up was 17 months (range 13-21).Results. Extra-hepatic manifestations at enrollment were: purpura and arthralgia (12 cases), peripheral neuropathy (10 cases) and marginal zone Blymphomas (2 cases). After a four-week DAA therapy, all patients became HCV-negative. Moreover, after 48 weeks since the beginning of DAA treatment, sustained regression of purpura and arthralgias was observed respectively in eight and in nine cases; peripheral neuropathy improved in seven cases, and cryocrit median values decreased from three (1-20) at baseline to two (1-12) after 48 weeks. Two cases with indolent marginal zone lymphomas did not show any haematological response: size and number of the involved nodes remained unchanged. In addition, the monoclonal B-cell population found in the peripheral blood in four cases did not disappear after recovery from HCV-RNA. Mild side effects occurred in nine patients, but six patients developed ribavirin-related anaemia requiring reduction of ribavirin dose.Conclusion. DAA therapy is safe and effective to eradicate HCV in MC, but seems associated with satisfactory clinical response in mild or moderate cryoglobulinaemic vasculitis and no response in B-NHL

    Sediment Transport of Fine Sand to Fine Gravel on Transverse Bed Slopes in Rotating Annular Flume Experiments

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    Large‐scale morphology, in particular meander bend depth, bar dimensions, and bifurcation dynamics, are greatly affected by the deflection of sediment transport on transverse bed slopes due to gravity and by secondary flows. Overestimating the transverse bed slope effect in morphodynamic models leads to flattening of the morphology, while underestimating leads to unrealistically steep bars and banks and a higher braiding index downstream. However, existing transverse bed slope predictors are based on a small set of experiments with a minor range of flow conditions and sediment sizes, and in practice models are calibrated on measured morphology. The objective of this research is to experimentally quantify the transverse bed slope effect for a large range of near‐bed flow conditions with varying secondary flow intensity, sediment sizes (0.17–4 mm), sediment transport mode, and bed state to test existing predictors. We conducted over 200 experiments in a rotating annular flume with counterrotating floor, which allows control of the secondary flow intensity separate from the streamwise flow velocity. Flow velocity vectors were determined with a calibrated analytical model accounting for rough bed conditions. We isolated separate effects of all important parameters on the transverse slope. Resulting equilibrium transverse slopes show a clear trend with varying sediment mobilities and secondary flow intensities that deviate from known predictors depending on Shields number, and strongly depend on bed state and sediment transport mode. Fitted functions are provided for application in morphodynamic modelin

    Impact of the radiographic examination on diagnosis and treatment decision of caries lesions in primary teeth – the Caries Detection in Children (CARDEC-01) trial: study protocol for a randomized controlled trial

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    Background Although most clinical guidelines throughout the world indicate that clinicians take two bitewings for detecting caries lesions in primary molars of all children, evidence for this recommendation is essentially based on cross-sectional studies performed in laboratory settings or using convenience samples. The benefits and impact of performing radiographs on diagnosis and treatment decision of caries lesions in primary teeth, mainly considering relevant outcomes for patients, have not been evaluated yet. Thus, the aim of this randomized clinical trial will be to evaluate the impact of performing radiographic examination adjunct to the visual inspection for detecting and making treatment decision regarding caries lesions in primary teeth compared with visual inspection performed alone. We will consider different outcomes related to children's health and welfare. Methods/Design To reach this objective, 250 children ages 3 to 6 years who sought dental treatment in our dental school will be randomly allocated in two groups according to the diagnostic strategy used for caries detection: visual inspection performed alone or visual inspection associated to radiographic examination. Two trained and calibrated examiners will carry out the examinations and elaborate the treatment decision plan. Then, children will be treated and followed up for 2 years, with evaluations after 12 and 24 months after the inclusion of children in the study. Children will also return after 6 and 18 months to reinforce the preventive orientations. Primary outcome will be the number of dental surfaces in need of dental treatment at the follow-up. Secondary outcomes will be the components of the primary outcome separately, as well as, proportion of false-positive results, the oral health-related quality of life, cost-efficacy, cost-adjusted life years, and number of new lesions in the first permanent molars. Discussion Our working hypothesis is that radiographic examination would actually exert little influence on patient-centered outcomes, and visual inspection would be enough as diagnostic strategy for caries detection in primary teeth

    Significance of cutoff in meandering river dynamics

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    The occurrence of cutoff events, although sporadic, is a key component in the complex dynamics of meandering rivers. In the present work, we show that cutoff has a twofold role: (1) It removes older meanders, limiting the planform geometrical complexity (geometrical role), and (2) it generates an intermittent noise that is able to influence the spatiotemporal dynamics of the whole river (dynamical role). The geometrical role limits the spatial evolution of the meanders, sporadically eliminating portions of the river planimetry. In this way it stabilizes the mean river geometry around a statistically steady state. The dynamical role is due to the propagation of a noise wave that is triggered by cutoff events. Because of the spatial memory component which is present in the meandering dynamics, such waves propagate all along the river, thus affecting its meandering dynamic

    Social and dental status along the life course and oral health impacts in adolescents: a population-based birth cohort

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    <p>Abstract</p> <p>Background</p> <p>Harmful social conditions in early life might predispose individuals to dental status which in turn may impact on adolescents' quality of life.</p> <p>Aims</p> <p>To estimate the prevalence of oral health impacts among 12 yr-old Brazilian adolescents (<it>n </it>= 359) and its association with life course socioeconomic variables, dental status and dental services utilization in a population-based birth cohort in Southern Brazil.</p> <p>Methods</p> <p>Exploratory variables were collected at birth, at 6 and 12 yr of age. The Oral Impacts on Daily Performances index (OIDP) was collected in adolescence and it was analyzed as a ranked outcome (OIDP from 0 to 9). Unadjusted and adjusted multivariable Poisson regression with robust variance was performed guided by a theoretical determination model.</p> <p>Results</p> <p>The response rate was of 94.4% (<it>n </it>= 339). The prevalence of OIDP = 1 was 30.1% (CI95%25.2;35.0) and OIDP ≄ 2 was 28.0% (CI95%23.2;32.8). The most common daily activity affected was eating (44.8%), follow by cleaning the mouth and smiling (15.6%, and 15.0%, respectively). In the final model mother schooling and mother employment status in early cohort participant's life were associated with OIDP in adolescence. As higher untreated dental caries at age 6 and 12 years, and the presence of dental pain, gingival bleeding and incisal crowing in adolescence as higher the OIDP score. On the other hand, dental fluorosis was associated with low OIDP score.</p> <p>Conclusion</p> <p>Our findings highlight the importance of adolescent's early life social environmental as mother schooling and mother employment status and the early and later dental status on the adolescent's quality of life regardless family income and use of dental services.</p

    Language production impairments in patients with a first episode of psychosis

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