412 research outputs found

    3DQ: Compact Quantized Neural Networks for Volumetric Whole Brain Segmentation

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    Model architectures have been dramatically increasing in size, improving performance at the cost of resource requirements. In this paper we propose 3DQ, a ternary quantization method, applied for the first time to 3D Fully Convolutional Neural Networks (F-CNNs), enabling 16x model compression while maintaining performance on par with full precision models. We extensively evaluate 3DQ on two datasets for the challenging task of whole brain segmentation. Additionally, we showcase our method's ability to generalize on two common 3D architectures, namely 3D U-Net and V-Net. Outperforming a variety of baselines, the proposed method is capable of compressing large 3D models to a few MBytes, alleviating the storage needs in space critical applications.Comment: Accepted to MICCAI 201

    Inequalities in residential nature and nature-based recreation are not universal: A country-level analysis in Austria

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    This is the final version. Available from Elsevier via the DOI in this record. Evidence suggests that residential nature, e.g., greenness around the home, and nature-based recreation, e.g., visits to specific natural locations, are beneficial for health and well-being. However, several studies report that residential access is lower among socio-economically disadvantaged communities, potentially exacerbating health inequalities. We explored this issue in Austria, a relatively rural and mountainous country that also contains several cities, including the capital Vienna with around 2 million citizens. Data were drawn from a representative survey of the adult population across all nine Austrian regions (N = 2258) and explored sociodemographic predictors of residential green and blue space (using satellite data on surrounding greenness and distance to rivers and lakes), and visit frequencies to 12 different urban and rural green/blue environments. In contrast to most findings elsewhere, which usually focus on relatively specific locations (e.g., cities), we found little evidence of socio-economic inequalities in residential green/blue space at the whole country level. Further, although frequent visits to specific environments were less likely among, e.g., people with lower vs. higher education, other typically disadvantaged groups, e.g., those self-identifying as belonging vs. not belonging to an ethnic minority, reported more visits to e.g., urban parks and rivers. Findings suggest that inequalities in nature exposure may not be universal when considered at a country level.European Union’s Horizon 2020Vienna Science and Technology Fund (WWTF

    Energy end-use flexibility of the next generation of decision-makers in a smart grid setting: an exploratory study

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    Demand Response (DR) mechanisms have been developed to reshape consumption patterns in face of price signals, enabling to deal with the increasing penetration of intermittent renewable resources and balance electricity demand and supply. Although DR mechanisms have been in place for some time, it is still unclear to what extent end-users are ready, or willing, to embrace DR programs that can be complex and imply adjustments of daily routines. This work aims to understand how the next generation of Portuguese decision makers, namely young adults in higher education, are prepared to deal with energy decisions in the context of the challenges brought by the smart grids. Results demonstrate that cost savings and the contribution to environmental protection are found to be important motivating factors to enroll into DR programs, which should be further exploited in future actions for the promotion of end-user engagement. Moreover, DR solutions are well-accepted by higher education students, although with limited flexibility levels. In addition, there is room to exploit the willingness to adopt time-differentiated tariffs, yet savings should be clearer and more attractive to end-users. Also, the framing effect should be considered when promoting this type of time-differentiated tariffs.This work was partially supported by project grants UID/MULTI/00308/2013 and UID/CEC/00319/2013 and by the European Regional Development Fund through the COMPETE 2020 Programme, FCT—Portuguese Foundation for Science and Technology with in projects ESGRIDS (POCI-01-0145-FEDER-016434), Learn2Behave (02/SAICT/2016-023651), MAnAGER (POCI-01-0145-FEDER-028040), and POCI-01-0145-FEDER-007043, as well as by the Energy for Sustainability Initiative of the University of Coimbra

    Risk, Unexpected Uncertainty, and Estimation Uncertainty: Bayesian Learning in Unstable Settings

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    Recently, evidence has emerged that humans approach learning using Bayesian updating rather than (model-free) reinforcement algorithms in a six-arm restless bandit problem. Here, we investigate what this implies for human appreciation of uncertainty. In our task, a Bayesian learner distinguishes three equally salient levels of uncertainty. First, the Bayesian perceives irreducible uncertainty or risk: even knowing the payoff probabilities of a given arm, the outcome remains uncertain. Second, there is (parameter) estimation uncertainty or ambiguity: payoff probabilities are unknown and need to be estimated. Third, the outcome probabilities of the arms change: the sudden jumps are referred to as unexpected uncertainty. We document how the three levels of uncertainty evolved during the course of our experiment and how it affected the learning rate. We then zoom in on estimation uncertainty, which has been suggested to be a driving force in exploration, in spite of evidence of widespread aversion to ambiguity. Our data corroborate the latter. We discuss neural evidence that foreshadowed the ability of humans to distinguish between the three levels of uncertainty. Finally, we investigate the boundaries of human capacity to implement Bayesian learning. We repeat the experiment with different instructions, reflecting varying levels of structural uncertainty. Under this fourth notion of uncertainty, choices were no better explained by Bayesian updating than by (model-free) reinforcement learning. Exit questionnaires revealed that participants remained unaware of the presence of unexpected uncertainty and failed to acquire the right model with which to implement Bayesian updating

    ArteFill® Permanent Injectable for Soft Tissue Augmentation: II. Indications and Applications

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    Patients ask for procedures with long-lasting effects. ArteFill is the first permanent injectable approved in 2006 by the FDA for nasolabial folds. It consists of cleaned microspheres of polymethylmethacrylate (PMMA) suspended in bovine collagen. Over the development period of 20 years most of its side effects have been eliminated to achieve the same safety standard as today’s hyaluronic acid products. A 5-year follow-up study in U.S. clinical trial patients has shown the same wrinkle improvement as seen at 6 months. Long-term follow-up in European Artecoll patients has shown successful wrinkle correction lasting up to 15 years. A wide variety of off-label indications and applications have been developed that help the physician meet the individual needs of his/her patients. Serious complications after ArteFill injections, such as granuloma formation, have not been reported due to the reduction of PMMA microspheres smaller than 20 μm to less than 1% “by the number.” Minor technique-related side effects, however, may occur during the initial learning curve. Patient and physician satisfaction with ArteFill has been shown to be greater than 90%

    A Treatment-Oriented Typology of Self-Identified Hypersexuality Referrals

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    Men and women have been seeking professional assistance to help control hypersexual urges and behaviors since the nineteenth century. Despite that the literature emphasizes that cases of hypersexuality are highly diverse with regard to clinical presentation and comorbid features, the major models for understanding and treating hypersexuality employ a “one size fits all” approach. That is, rather than identify which problematic behaviors might respond best to which interventions, existing approaches presume or assert without evidence that all cases of hypersexuality (however termed or defined) represent the same underlying problem and merit the same approach to intervention. The present article instead provides a typology of hypersexuality referrals that links individual clinical profiles or symptom clusters to individual treatment suggestions. Case vignettes are provided to illustrate the most common profiles of hypersexuality referral that presented to a large, hospital-based sexual behaviors clinic, including: (1) Paraphilic Hypersexuality, (2) Avoidant Masturbation, (3) Chronic Adultery, (4) Sexual Guilt, (5) the Designated Patient, and (6) better accounted for as a symptom of another condition

    From Plants to Birds: Higher Avian Predation Rates in Trees Responding to Insect Herbivory

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    BACKGROUND: An understanding of the evolution of potential signals from plants to the predators of their herbivores may provide exciting examples of co-evolution among multiple trophic levels. Understanding the mechanism behind the attraction of predators to plants is crucial to conclusions about co-evolution. For example, insectivorous birds are attracted to herbivore-damaged trees without seeing the herbivores or the defoliated parts, but it is not known whether birds use cues from herbivore-damaged plants with a specific adaptation of plants for this purpose. METHODOLOGY: We examined whether signals from damaged trees attract avian predators in the wild and whether birds could use volatile organic compound (VOC) emissions or net photosynthesis of leaves as cues to detect herbivore-rich trees. We conducted a field experiment with mountain birches (Betula pubescens ssp. czerepanovii), their main herbivore (Epirrita autumnata) and insectivorous birds. Half of the trees had herbivore larvae defoliating trees hidden inside branch bags and half had empty bags as controls. We measured predation rate of birds towards artificial larvae on tree branches, and VOC emissions and net photosynthesis of leaves. PRINCIPAL FINDINGS AND SIGNIFICANCE: The predation rate was higher in the herbivore trees than in the control trees. This confirms that birds use cues from trees to locate insect-rich trees in the wild. The herbivore trees had decreased photosynthesis and elevated emissions of many VOCs, which suggests that birds could use either one, or both, as cues. There was, however, large variation in how the VOC emission correlated with predation rate. Emissions of (E)-DMNT [(E)-4,8-dimethyl-1,3,7-nonatriene], beta-ocimene and linalool were positively correlated with predation rate, while those of highly inducible green leaf volatiles were not. These three VOCs are also involved in the attraction of insect parasitoids and predatory mites to herbivore-damaged plants, which suggests that plants may not have specific adaptations to signal only to birds
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