368 research outputs found

    Online Bayesian Analysis

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    In the last few years, there has been active research on aggregating advanced statistical measures in multidimensional data cubes from partitioned subsets of data. In this paper, we propose an online compression and aggregation scheme to support Bayesian estimations in data cubes based on the asymptotic properties of Bayesian statistics. In the proposed approach, we compress each data segment by retaining only the model parameters and a small amount of auxiliary measures. We then develop an aggregation formula that allows us to reconstruct the Bayesian estimation from partitioned segments with a small approximation error. We show that the Bayesian estimates and the aggregated Bayesian estimates are asymptotically equivalent

    Editorial: Social cognition and mental health among children and youth

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    This editorial comment on “Social cognition and mental health among children and youth” aims to provide a forum to improve research in this field and its contribution to health psychology, the understanding of risk and protective factors, and the exploration of innovative psychosocial interventions to benefit children and youth's health and wellbeing. People's feelings and social experiences are very influenced by their social, cultural, educational and autobiographical contexts. Nota: Parte de texto retirado do corpo do artigo.info:eu-repo/semantics/publishedVersio

    Automatic thickness estimation for skeletal muscle in ultrasonography: evaluation of two enhancement methods

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    BACKGROUND: Ultrasonography is a convenient technique to investigate muscle properties and has been widely used to look into muscle functions since it is non-invasive and real-time. Muscle thickness, a quantification which can effectively reflect the muscle activities during muscle contraction, is an important measure for musculoskeletal studies using ultrasonography. The traditional manual operation to read muscle thickness is subjective and time-consuming, therefore a number of studies have focused on the automatic estimation of muscle fascicle orientation and muscle thickness, to which the speckle noises in ultrasound images could be the major obstacle. There have been two popular methods proposed to enhance the hyperechoic regions over the speckles in ultrasonography, namely Gabor Filtering and Multiscale Vessel Enhancement Filtering (MVEF). METHODS: A study on gastrocnemius muscle is conducted to quantitatively evaluate whether and how these two methods could help the automatic estimation of the muscle thickness based on Revoting Hough Transform (RVHT). The muscle thickness results obtained from each of the two methods are compared with the results from manual measurement, respectively. Data from an aged subject with cerebral infarction is also studied. RESULTS: It’s shown in the experiments that, Gabor Filtering and MVEF can both enable RVHT to generate comparable results of muscle thickness to those by manual drawing (mean ± SD, 1.45 ± 0.48 and 1.38 ± 0.56 mm respectively). However, the MVEF method requires much less computation than Gabor Filtering. CONCLUSIONS: Both methods, as preprocessing procedure can enable RVHT the automatic estimation of muscle thickness and MVEF is believed to be a better choice for real-time applications

    EXPERIMENTAL STUDY OF WELDING RESIDUAL STRESS OF HIGH-STRENGTH SHIPBUILDING STEEL

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    Ships are large welded structures. Welding residual stress (WRS) significantly impacts the mechanical properties of the structure. The plate and cylinder models welded by electrode welding (EW) and submerged arc welding (SAW) were designed to measure the WRS of high-strength shipbuilding steel. The WRS was measured by instrumented indentation method. The stress value of each measure point was proposed. The stress distribution patterns of different welding processes and models were analysed. This research can provide a reference for controlling the WRS of ships and improving shipbuilding quality

    Effects of Condylar Elastic Properties to Temporomandibular Joint Stress

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    Mandibular condyle plays an important role in the growth and reconstruction of the temporomandibular joint (TMJ). We aimed to obtain orthotropic elastic parameters of the condyle using a continuous-wave ultrasonic technique and to observe the effects of condylar elastic parameters on stress distribution of the TMJ using finite element analysis (FEA). Using the ultrasonic technique, all nine elastic parameters were obtained, which showed that the mandibular condyle was orthotropic. With the condyle defined as orthotropic, the occlusal stress was transferred fluently and uniformly from the mandible to the TMJ. The stress distribution in the isotropic model showed stepped variation among different anatomical structures with higher stress values in the cartilage and condyle than in the orthotropic model. We conclude that anisotropy has subtle yet significant effects on stress distribution of the TMJ and could improve the reality of simulations

    Editorial: Social cognition and mental health among children and youth

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    This editorial comment on 'Social cognition and mental health among children and youth' aims to provide a forum to improve research in this field and its contribution to health psychology, the understanding of risk and protective factors, and the exploration of innovative psychosocial interventions to benefit children and youth's health and wellbeing. People's feelings and social experiences are very influenced by their social, cultural, educational and autobiographical contexts

    Engineering yeast for high-level production of diterpenoid sclareol

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    The diterpenoid sclareol is an industrially important precursor for alternative sustainable supply of ambergris. However, its current production from plant extraction is neither economical nor environmental-friendly, since it requires laborious and cost-intensive purification procedures and plants cultivation is susceptible to environmental factors. Engineering cell factories for bio-manufacturing can enable sustainable production of natural products. However, stringent metabolic regulation poses challenges to rewire cellular metabolism for overproduction of compounds of interest. Here we used a modular approach to globally rewire the cellular metabolism for improving sclareol production to 11.4 g/L in budding yeast Saccharomyces cerevisiae, the highest reported diterpenoid titer in microbes. Metabolic flux analysis showed that modular balanced metabolism drove the metabolic flux toward the biosynthesis of targeted molecules, and transcriptomic analysis revealed that the expression of central metabolism genes was shaped for a new balanced metabolism, which laid a foundation in extensive metabolic engineering of other microbial species for sustainable bio-production
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