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关键词： Coronary heart disease   Prediction   Risk assessment chart  

摘要： Background Cardiovascular disease is the leading cause of death and disability in Egypt. An appropriate estimation of risk is important to improve cardiovascular outcomes and ensure efficient allocation of resources used to support disease prevention. Risk prediction charts have been developed to provide clinicians with a simple tool to estimate the absolute risk of developing coronary heart disease (CHD). Objectives To test the accuracy of the World Health Organization/International Society of Hypertension (WHO/ISH) risk prediction charts in predicting and identifying people at risk of developing CHD and to propose an alternative risk assessment instrument based on simple laboratory tests, routine examination, and reported personal and medical data. Methods A cross-sectional screening survey was conducted at an emergency department of a health insurance hospital in Alexandria, Egypt. A total of 350 enrolled patients were evaluated clinically. We applied the WHO/ISH risk assessment chart for the Eastern Mediterranean region to test its accuracy in predicting CHD. Results The validation statistics indicated that the WHO/ISH risk prediction charts identified cases with CHD with 60.0% sensitivity and 93.2% specificity. At least nine risk factors for developing CHD were detected in all patients in the study cohort. Hypertension was the strongest predictor of CHD [odds ratio (OR) (95% confidence interval (CI)): 20.8 (5.6-76.9)]. Silent cardiovascular risk factors were ascertained in about 30% of the studied population, a finding that did not differ significantly by sex. We propose a different risk assessment model for general practice that incorporates standard cardiovascular risk factors, with or without laboratory tests. Conclusions Standard cardiovascular risk factors included in a simple risk prediction algorithm can predict multivariate CHD risk in apparently healthy individuals. Non-laboratory-based risk assessment models have no superior advantage over those emplo

关键词： Triangulated category   Self-injective   Brauer tree   Differential graded algebra  

摘要： Let A be a finite-dimensional, self-injective algebra, graded in non-positive degree. We define A -dgstab, the differential graded stable category of A, to be the Verdier quotient of the bounded derived category of dg-modules by the thick subcategory of perfect dg-modules. We express A -dgstab as the triangulated hull of the orbit category A -grstab /omega(1), reducing computations in the dg-stable category to those in the graded stable category. We provide a sufficient condition for the orbit category to be equivalent to A -dgstab and show this condition is satisfied by Nakayama algebras and Brauer tree algebras. We also provide a detailed description of the dgstable category of the Brauer tree algebra corresponding to the star with n edges. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://***/licenses/by/4.0/).

关键词： beverage demand   beverage prices   milk consumption   nonprice competition   price competition   vector autoregressive model (VAR)  

摘要： US per capita milk consumption has been falling since the 1940s and falling at an accelerated rate in recent years. One possible reason is competition between it and other types of beverages. In this study, we determine whether changes in beverage prices are in a direction and of a sufficient magnitude for consumption trends to be explained by price competition between milk and other beverages. They are not. We also estimate a vector autoregressive model using data on households' average weekly purchases of milk and four other, major beverage categories for a very general test of whether any increase in sales of those other beverages would come at milk's expense. Results again suggest that competition between milk and the identified other major beverages is not responsible for milk's accelerated decline, and there is a need for the research community to investigate other possible explanations. [EconLit Citations: D12, Q11, Q18].

关键词： Cortex   Learning and memory   Sensory processing   Visual system   Biomedicine   general   Neurosciences   Behavioral Sciences   Biological Techniques   Neurobiology   Animal Genetics and Genomics  

摘要： Goltstein et al. investigate the role of mouse visual cortical areas in information-integration category learning. They report widespread changes in neuronal response properties, most prominently in a higher visual area, the postrhinal cortex. Associative memories are stored in distributed networks extending across multiple brain regions. However, it is unclear to what extent sensory cortical areas are part of these networks. Using a paradigm for visual category learning in mice, we investigated whether perceptual and semantic features of learned category associations are already represented at the first stages of visual information processing in the neocortex. Mice learned categorizing visual stimuli, discriminating between categories and generalizing within categories. Inactivation experiments showed that categorization performance was contingent on neuronal activity in the visual cortex. Long-term calcium imaging in nine areas of the visual cortex identified changes in feature tuning and category tuning that occurred during this learning process, most prominently in the postrhinal area (POR). These results provide evidence for the view that associative memories form a brain-wide distributed network, with learning in early stages shaping perceptual representations and supporting semantic content downstream.

关键词： Dialectica Categories   Axiom of Choice   Partition Principle   cardinal invariants of the continuum  

摘要： The method of morphisms is a well-known application of Dialectica categories to set theory (more precisely, to the theory of cardinal invariants of the continuum). In a previous work, Valeria de Paiva and the author have asked how much of the Axiom of Choice is needed in order to carry out the referred applications of such method. In this paper, we show that, when considered in their full generality, those applications of Dialectica categories give rise to equivalents (within ZF) of either the Axiom of Choice (AC) or Partition Principle (PP)-which is a consequence of AC whose precise status of its relationship with AC itself is an open problem for more than a hundred years.

关键词： Ensemble learning   Feature selection   Error rate   Classification ability   Classification accuracy  

摘要： Adaptive boosting (Adaboost) is a typical ensemble learning algorithm, which has been studied and widely used in classification tasks. Traditional Adaboost algorithms ignore the sample weights while selecting the most useful features, and most of them ignore the fact that the performances of weak classifiers on each category are always different. On this basis, a weighted feature selection and category classification confidence based Adaboost algorithm is proposed in this paper. The first contribution, is that we propose a weighted feature selection to select the most useful features, which can both distinguish the majority of all samples and the previous misclassified samples. The second contribution, is that we improve the traditional error rate calculation method and propose a category based error rate calculation method to combine the classification abilities of Adaboost on different categories. A detailed performances comparison of various Adaboost algorithms are carried out on eight typical datasets. The experimental results show that the proposed algorithm obtains significant improvement on classification accuracy compared to typical Adaboost algorithms when different datasets especially the unbalanced datasets are used.

关键词： Crowdsourcing systems   Mechanism design  

摘要： Crowdsourcing harnesses human effort to solve computer-hard problems such as photo tagging, entity resolution and sentiment analysis. Such tasks often have different levels of difficulty and workers have varying levels of skill at completing them. With a limited budget, it is important to wisely allocate the spend among the tasks and workers such that the overall outcome is as good as possible. Most existing work addresses this budget allocation problem by assuming that workers have a single level of ability for all tasks and each task involves a choice between just two alternatives. However, this neglects the fact that many crowdsourcing applications ask workers to choose between multiple alternatives and that different tasks can belong to a variety of diverse categories. Moreover, workers may have varying abilities across these categories. For example, a science enthusiast is likely to do better than a cinephile when answering a question such as "selecting the melting point of Copper from 1) 327 degrees Celcius, 2) 1085 degrees Celcius and 3) 1495 degrees Celcius". And a cinephile is likely to perform better in tasks related to movies such as "how many episodes of Fooly Cooly were ever made? 1) 6 2) 7 and 3) 8". To incorporate such category-aware crowdsourcing of multiple-choice tasks, we model the interaction between the crowdsource campaign initiator and the workers as a procurement auction and propose a computationally efficient mechanism, INCARE, to achieve high-quality outcomes given a limited budget. We prove that INCARE is budget feasible, incentive compatible and individually rational. We also prove that INCARE can achieve a bounded approximation ratio for the optimal budget allocation mechanism with full knowledge of workers' true costs. Finally, our numerical simulations, on both real and synthetic data, show that, compared to the state of the art, INCARE: (i) can improve the accuracy by up to 98%, given a limited budget;and (ii) is significantly more ro

关键词： Quantum group   Unitary easy quantum group   Unitary group   Half-liberation   Tensor category   Two-colored partition   Partition of a set   Category of partitions   Brauer algebra  

摘要： This article is part of a series with the aim of classifying all non-hyperoctahedral categories of two-colored partitions. Those constitute by some Tannaka-Krein type result the representation categories of a specific class of quantum groups. In Part I we introduced a class of parameters which gave rise to many new non-hyperoctahedral categories of partitions. In the present article we show that this class actually contains all possible parameter values of all non-hyperoctahedral categories of partitions. This is an important step towards the classification of all non-hyperoctahedral categories.

关键词： behavioural responses   event-related potentials (ERPs)   levels of object categorisation   N170   task-related information  

摘要： What do we perceive in a glance of an object? If we are questioned about it, will our perception be affected? How does the task demand influence visual processing in the brain and, consequently, our behaviour? To address these questions, we conducted an object categorisation experiment with three tasks, one at the superordinate level ('animate/inanimate') and two at the basic levels ('face/body' and 'animal/human face') along with a passive task in which participants were not required to categorise objects. To control bottom-up information and eliminate the effect of sensory-driven dissimilarity, we used a particular set of animal face images as the identical target stimuli across all tasks. We then investigated the impact of top-down task demands on behaviour and brain representations. Behavioural results demonstrated a superordinate advantage in the reaction time, while the accuracy was similar for all categorisation levels. The event-related potentials (ERPs) for all categorisation levels were highly similar except for about 170 ms and after 300 ms from stimulus onset. In these time windows, the animal/human face categorisation, which required fine-scale discrimination, elicited a differential ERP response. Similarly, decoding analysis over all electrodes showed the highest peak value of task decoding around 170 ms, followed by a few significant timepoints, generally after 300 ms. Moreover, brain responses revealed task-related neural modulation during categorisation tasks compared with the passive task. Overall, these findings demonstrate different task-related effects on the behavioural response and brain representations. The early and late components of neural modulation could be linked to perceptual and top-down processing of object categories, respectively.

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摘要： Background This study was designed to investigate the association between Liver Imaging Reporting and Data System (LI-RADS) category and recurrence of hepatocellular carcinoma (HCC) after primary liver transplantation (LT) within the Milan criteria. Methods This multicenter, retrospective study included 140 recipients who underwent living donor LT (LDLT) for treatment-naive HCC and pretransplant contrast-enhanced magnetic resonance imaging (MRI) between 2009 and 2013. LI-RADS categories were assigned using LI-RADS version 2018. Recurrence-free survival (RFS) and associated factors were evaluated using Cox proportional hazards regression analysis, Kaplan-Meier analysis, and log-rank test. Histological grading and microvascular invasion (MVI) were analyzed on the pathologic examinations of explanted livers. Results The overall 1-, 3-, 5-, and 7-year RFS rates were 95.6%, 92.6%, 90.2%, and 89.3%, respectively. In the multivariable analysis, independent predictors of recurrence included HCCs categorized as LR-M (hazard ratio [HR], 18.68;95% confidence interval [CI], 5.79-60.23;P < 0.001) and the largest tumor size of >= 3 cm on MRI (HR, 4.18;95% CI, 1.42-12.37;P = 0.010). The 5-year RFS rate was significantly lower in patients with HCCs categorized as LR-M than in those with HCCs categorized as LR-5 or 4 (LR-5/4) (36.9% vs. 95.8%, respectively;P < 0.001). HCCs categorized as LR-M exhibited significantly more MVI than HCCs categorized as LR-5/4 (57.1% vs. 17.5%, respectively;P = 0.002). Conclusions Patients with HCCs categorized as LR-M using LI-RADS version 2018 may have a worse prognosis after primary LT within the Milan criteria than those with HCCs categorized as LR-5/4.