448 research outputs found

    Review: Object vision in a structured world

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    In natural vision, objects appear at typical locations, both with respect to visual space (e.g., an airplane in the upper part of a scene) and other objects (e.g., a lamp above a table). Recent studies have shown that object vision is strongly adapted to such positional regularities. In this review we synthesize these developments, highlighting that adaptations to positional regularities facilitate object detection and recognition, and sharpen the representations of objects in visual cortex. These effects are pervasive across various types of high-level content. We posit that adaptations to real-world structure collectively support optimal usage of limited cortical processing resources. Taking positional regularities into account will thus be essential for understanding efficient object vision in the real world

    double dissociation between the extrastriate body area and the posterior superior temporal sulcus during biological motion perception converging evidence from tms and fmri

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    Our brains engage numerous regions when exposed to biological motion, with the posterior superior temporal sulcus (pSTS) being the primary locus. The exact roles of hMT+ and the extrastriate body area (EBA) remain unclear. Here, we set out to determine the specific roles of pSTS and EBA during biological motion perception, focusing on walker orientation and walking direction. To obtain converging evidence, we conducted separate TMS and fMRI experiments within the same subjects (N = 12). Two separate tasks were used in the TMS study: walker orientation probing form processing and walking direction probing motion/sequence processing. Task performance was compared before and after applying repetitive offline TMS (1 Hz) over EBA and pSTS (based on fMRI-guided stereotaxy). In the fMRI study, EBA and pSTS were mapped in separate scans using standard localizers. Subsequently, runs with point-light walkers were subjected to MVPA, determining the amount of static (orientation) and dynamic (direction) information p..

    Nonstimulated early visual areas carry information about surrounding context

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    Even within the early sensory areas, the majority of the input to any given cortical neuron comes from other cortical neurons. To extend our knowledge of the contextual information that is transmitted by such lateral and feedback connections, we investigated how visually nonstimulated regions in primary visual cortex (V1) and visual area V2 are influenced by the surrounding context. We used functional magnetic resonance imaging (fMRI) and pattern-classification methods to show that the cortical representation of a nonstimulated quarter-field carries information that can discriminate the surrounding visual context. We show further that the activity patterns in these regions are significantly related to those observed with feed-forward stimulation and that these effects are driven primarily by V1. These results thus demonstrate that visual context strongly influences early visual areas even in the absence of differential feed-forward thalamic stimulation

    Validation of FEM models describing moisture transport in heated concrete by Magnetic Resonance Imaging

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    Fire safety of buildings and structures is an important issue, and has a great impact on human life and economy. One of the processes negatively affecting the strength of a concrete building or structure during fire is spalling. Many examples exists in which spalling of concrete during fire has caused severe damage to structures, such as in the Mont Blanc and Channel Tunnel. Especially newly developed dense types of concrete such as HPC and SCC, have shown to be sensitive to spalling, hampering the application of these new concrete types. To reduce risks and building costs, the processes behind spalling need to be understood. Increasing our knowledge allows us to reliably predict the behaviour and take effective and cost friendly preventive measures. Moisture present in concrete is one of the reasons for spalling. When concrete is heated water will evaporate, which results in a high gas pressure inside the pores of concrete. This high gas pressure can induce spalling. To attain a better understanding of this process, a first step was taken to develop a finite element model (FEM) describing this transport of moisture in heated concrete. However, the validity of all current models (including our own) is unknown because of debatable input parameters and lack of experimental techniques to follow the transport process in situ. In cooperation with the Eindhoven University of Technology moisture transport in heated concrete can now be investigated with a home built dedicated 1D Magnetic Resonance Imaging (MRI) setup. Using the results of the MRI experiments the validity of our FEM models has been assessed for the first time. A general correspondence is observed. The FEM model described in this paper is a simplified FEM model compared to literature models. Already this simplified model shows a good correspondence with the MRI measurements

    Object Vision in a Structured World

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    In natural vision, objects appear at typical locations, both with respect to visual space (e.g., an airplane in the upper part of a scene) and other objects (e.g., a lamp above a table). Recent studies have shown that object vision is strongly adapted to such positional regularities. In this review we synthesize these developments, highlighting that adaptations to positional regularities facilitate object detection and recognition, and sharpen the representations of objects in visual cortex. These effects are pervasive across various types of high-level content. We posit that adaptations to real-world structure collectively support optimal usage of limited cortical processing resources. Taking positional regularities into account will thus be essential for understanding efficient object vision in the real world

    Volume, outcome, and the organization of intensive care

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    Increasing evidence suggests that high case volume is associated with improved outcomes in the intensive care unit (ICU). Potential explanations for the volume–outcome relationship include selective referral, clinical experience and organizational factors common to high-volume ICUs. Distinguishing between these explanations has important health policy implications, because outcomes at low-volume ICUs could be improved either by exporting best practices found at high-volume centers or by regionalizing adult critical care – two very different care strategies. Future research efforts should be directed at better characterizing the process of care in high-volume ICUs and exploring the feasibility of creating a regionalized system of care

    Схема когенерации с размещением противодавленческой и гидропаровой турбин на общем валу с газопоршневой установкой

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    Показана перспективність використання когенераційних технологій для підвищення рентабельності вугільних підприємств. Розглянуто схему з розміщенням турбіни з противотиском і гідропарової турбіни на одному валу з газопоршневою установкою. Використання даної схеми для утилізації надлишкового тепла шахтних енергокомплексів дозволить отримати коефіцієнт корисної дії 64 % та зменшити витрати палива.In this paper the perspective use of cogeneration technology enhance the profitability of coal enterprises was discussed. The scheme with setting back-pressures and steam-water turbines on one shaft of gas engine was considered. Using this scheme for utilization of surplus heat mine energy complexes will provide efficiency of 64% and reduce fuel

    An exploratory study looking at the relationship marketing techniques used in the music festival industry

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    There are current issues and trends in the music festival market, which may affect the success of an event, and market saturation is at the forefront of these issues. Previous literature, maintaining the need for a marketing approach to festivals, identifi es the need for maintaining strong stakeholder relationships in order to succeed in a business environment; attention has been focused to the theory of relationship marketing (RM) because of the recognition that this practice is complementary to the marketing of festivals. The very nature of the music festival as an annual, usually, 4-day event means that effective marketing is needed to keep connections with the consumer throughout the year. This article focuses on the RM techniques utilised within the music festival industry from the viewpoint of the festival organiser in an attempt to establish how festival organisations value and monitor organisational relationships. This article explores the extent to which these relationships are valued and managed; furthermore, the variations between these intricate relationships are considered by focusing on those held with the organisation ’ s consumers and sponsors, the results of which have provided the ability to establish the importance and relevance of RM to the industry and further identify the marketing communication methods employed to establish and maintain such relationships. In-depth, convergent interviews have been conducted with a segment of music festival organisers from a range of events. The results have been integrated with the study of current literature to best exemplify these issues. It has been established that RM has a strong role in today ’ s commercial and independent music festival industry; technological advances are enabling the organiser to support online relationships further and increase consumer loyalty. There is a need to expand the research further because of the complexity of organisational relationships and the varying categories of festivals

    Prediction models for development of retinopathy in people with type 2 diabetes:systematic review and external validation in a Dutch primary care setting

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    Aims/hypothesis: The aims of this study were to identify all published prognostic models predicting retinopathy risk applicable to people with type 2 diabetes, to assess their quality and accuracy, and to validate their predictive accuracy in a head-to-head comparison using an independent type 2 diabetes cohort. Methods: A systematic search was performed in PubMed and Embase in December 2019. Studies that met the following criteria were included: (1) the model was applicable in type 2 diabetes; (2) the outcome was retinopathy; and (3) follow-up was more than 1 year. Screening, data extraction (using the checklist for critical appraisal and data extraction for systemic reviews of prediction modelling studies [CHARMS]) and risk of bias assessment (by prediction model risk of bias assessment tool [PROBAST]) were performed independently by two reviewers. Selected models were externally validated in the large Hoorn Diabetes Care System (DCS) cohort in the Netherlands. Retinopathy risk was calculated using baseline data and compared with retinopathy incidence over 5 years. Calibration after intercept adjustment and discrimination (Harrell’s C statistic) were assessed. Results: Twelve studies were included in the systematic review, reporting on 16 models. Outcomes ranged from referable retinopathy to blindness. Discrimination was reported in seven studies with C statistics ranging from 0.55 (95% CI 0.54, 0.56) to 0.84 (95% CI 0.78, 0.88). Five studies reported on calibration. Eight models could be compared head-to-head in the DCS cohort (N = 10,715). Most of the models underestimated retinopathy risk. Validating the models against different severities of retinopathy, C statistics ranged from 0.51 (95% CI 0.49, 0.53) to 0.89 (95% CI 0.88, 0.91). Conclusions/interpretation: Several prognostic models can accurately predict retinopathy risk in a population-based type 2 diabetes cohort. Most of the models include easy-to-measure predictors enhancing their applicability. Tailoring retinopathy screening frequency based on accurate risk predictions may increase the efficiency and cost-effectiveness of diabetic retinopathy care. Registration: PROSPERO registration ID CRD42018089122

    Liver function tests and risk prediction of incident type 2 diabetes:evaluation in two independent cohorts

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    BACKGROUND: Liver function tests might predict the risk of type 2 diabetes. An independent study evaluating utility of these markers compared with an existing prediction model is yet lacking. METHODS AND FINDINGS: We performed a case-cohort study, including random subcohort (6.5%) from 38,379 participants with 924 incident diabetes cases (the Dutch contribution to the European Prospective Investigation Into Cancer and Nutrition, EPIC-NL, the Netherlands), and another population-based cohort study including 7,952 participants with 503 incident cases (the Prevention of Renal and Vascular End-stage Disease, PREVEND, Groningen, the Netherlands). We examined predictive value of combination of the Liver function tests (gamma-glutamyltransferase, alanine aminotransferase, aspartate aminotransferase and albumin) above validated models for 7.5-year risk of diabetes (the Cooperative Health Research in the Region of Augsburg, the KORA study). Basic model includes age, sex, BMI, smoking, hypertension and parental diabetes. Clinical models additionally include glucose and uric acid (model1) and HbA1c (model2). In both studies, addition of Liver function tests to the basic model improved the prediction (C-statistic by~0.020; NRI by~9.0%; P<0.001). In the EPIC-NL case-cohort study, addition to clinical model1 resulted in statistically significant improvement in the overall population (C-statistic = +0.009; P<0.001; NRI = 8.8%; P<0.001), while addition to clinical model 2 yielded marginal improvement limited to men (C-statistic = +0.007; P = 0.06; NRI = 3.3%; P = 0.04). In the PREVEND cohort study, addition to clinical model 1 resulted in significant improvement in the overall population (C-statistic change = 0.008; P = 0.003; NRI = 3.6%; P = 0.03), with largest improvement in men (C-statistic change = 0.013; P = 0.01; NRI = 5.4%; P = 0.04). In PREVEND, improvement compared to clinical model 2 could not be tested because of lack of HbA1c data. CONCLUSIONS: Liver function tests modestly improve prediction for medium-term risk of incident diabetes above basic and extended clinical prediction models, only if no HbA1c is incorporated. If data on HbA1c are available, Liver function tests have little incremental predictive value, although a small benefit may be present in men
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