35 research outputs found

    Flexible Scheduling in Multimedia Kernels: an Overview

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    Current Hard Real-Time (HRT) kernels have their timely behaviour guaranteed on the cost of a rather restrictive use of the available resources. This makes current HRT scheduling techniques inadequate for use in a multimedia environment where we can make a considerable profit by a better and more flexible use of the resources. We will show that we can improve the flexibility and efficiency of multimedia kernels. Therefore we introduce Real Time Transactions (RTT) with Deadline Inheritance policies for a small class of scheduling algorithms and we will evaluate these algorithms for use in a multimedia environmen

    Non-steroidal anti-inflammatory drugs and the risk of psychosis

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    The objective of the current research was to examine the relation between nonsteroidal anti-inflammatory drugs (NSAID) use and risk of psychosis. To this end we performed a longitudinal case-control study using prescription data from a Dutch health insurance company. Men aged 25 years or over and women aged 30 years or over were excluded to prevent inclusion of non-incident cases. This resulted in eighty-two cases and 359 randomly selected controls from the same population. The overall relative risk of incident antipsychotic use for NSAID users, adjusted for age and prescription frequency, was 0.80 (95% CI: 0.48-1.33). After stratification for gender the risk of psychosis was significantly lower (59%) in male NSAID users only. The relative risks for male and female subjects were 0.41 (95% CI: 0.17-0.97) and 1.31 (95% CI: 0.65-2.64), respectively. These results suggest that in men NSAIDs may lower the risk of psychosis. (c) 2006 Elsevier B.V. and ECNP. All rights reserved

    Meta-analysis of 701 published cases of sinonasal neuroendocrine carcinoma:The importance of differentiation grade in determining treatment strategy

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    AbstractThe aim of this meta-analysis was to provide treatment guidelines for sinonasal neuroendocrine carcinoma (SNC) by combining all available data in the literature.A literature search for all studies concerning SNC was performed against the MEDLINE and EMBASE databases. Available clinical data was normalized, pooled, and statistically analyzed.A total of 701 cases of SNC were available for analysis, comprising 127 well or moderately differentiated sinonasal neuroendocrine carcinomas (SNEC), 459 sinonasal undifferentiated carcinoma (SNUC) and 115 sinonasal small cell carcinoma (SmCC). Tumor type was the most important predictor of survival, with a 5-year disease-specific survival (DSS) of 70.2% for SNEC, 35.9% for SNUC and 46.1% for SmCC. Tumor stage on presentation was of limited value in predicting survival or response to treatment. Overall, the application of surgery yielded significantly better results (5-year DSS 52.2% versus 30.1%, p<0.001). In SNUC, radiotherapy was a beneficial supplement to surgery (5-year DSS 54.7% versus 15.7%, p=0.027), while radiotherapy as monotherapy performed poorly (5-year DSS 17.9%). Chemotherapy did not appear to contribute to survival.Based on these findings, we can conclude that the most important predictors of survival in SNC are differentiation grade and the associated choice of treatment modality. In contrast to other head and neck cancers, tumor staging appears of limited value in predicting survival or deciding on a treatment strategy. Surgery should be the cornerstone of treatment, supplemented by radiotherapy in poorly differentiated subtypes (SNUC, SmCC). Chemotherapy does not appear to contribute to survival

    Predictors for distant metastasis in head and neck cancer, with emphasis on age

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    PURPOSE: Distant metastasis (DM) in patients with head and neck squamous cell carcinoma (HNSCC) is uncommon, but strongly deteriorates prognosis. Controversy exists regarding age as a predictor for the presence and development of DM. The aim of this study was to investigate age and other predictors for DM in HNSCC patients. METHODS: From 1413 patients diagnosed with a primary HNSCC between 1999 and 2010 in a tertiary referral centre, patient, disease and pathological characteristics were extracted from patient files. Uni- and multivariable Cox regression analyses were performed to identify risk factors for DM as primary outcome. RESULTS: DM occurred in 131 (9.3%) patients, of which 27 (1.9%) were diagnosed simultaneously with the primary tumour, 27 (1.9%) were diagnosed synchronous, and 77 (5.4%) were diagnosed metachronous. The most common site of DM was lung (51.1%), followed by bone (19.1%) and liver (11.5%). Multivariable analysis identified male gender (HR = 1.95, 95% CI 1.23-3.10) hypopharyngeal tumours (HR = 3.28, 95% CI 1.75-6.14), advanced T-stage (HR = 1.61, 95% CI 1.09-2.38), poor differentiation grade (HR = 2.49, 95% CI 1.07-5.78), regional lymph node metastasis (HR = 5.35, 95% CI 3.25-8.79) and extranodal extension of regional lymph nodes metastasis (HR = 3.06, 95% CI 1.39-6.72) as independent prognostic factors for the presence or development of DM. No relation with age was found. CONCLUSION: Age is not related to the presence or development of DM. This study emphasizes the importance of screening for DM, especially in males, patients with hypopharyngeal tumours, advanced T-stage, histopathological poor differentiation grade, regional lymph node metastasis and extranodal extension

    Patterns of long-term swallowing dysfunction after definitive radiotherapy or chemoradiation

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    Objectives: To identify patterns of long-term, radiation-induced swallowing dysfunction after definitive radiotherapy with or without chemotherapy (RT or CHRT) and to determine which factors may explain these patterns over time.Material and methods: The study population consisted of 238 consecutive head and neck cancer patients treated with RT or CHRT. The primary endpoint was &gt;= grade 2 swallowing dysfunction at 6, 12, 18 and 24 months after treatment. Cluster analysis was used to identify different patterns over time. The differences between the mean dose to the swallowing organs at risk for each pattern were determined by using dose maps.Results: The cluster analysis revealed five patterns of swallowing dysfunction: low persistent, intermediate persistent, severe persistent, transient and progressive. Patients with high dose to the upper pharyngeal, laryngeal and lower pharyngeal region had the highest risk of severe persistent swallowing dysfunction. Transient problems mainly occurred after high dose to the laryngeal and lower pharyngeal regions, combined with moderate dose to the upper pharyngeal region. The progressive pattern was mainly seen after moderate dose to the upper pharyngeal region.Conclusions: Various patterns of swallowing dysfunction after definitive RT or CHRT can be identified over time. This could reflect different underlying biological processes. (C) 2015 The Authors. Published by Elsevier Ireland Ltd.</p

    Development and validation of a prediction model for tube feeding dependence after curative (chemo-) radiation in head and neck cancer

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    BACKGROUND: Curative radiotherapy or chemoradiation for head and neck cancer (HNC) may result in severe acute and late side effects, including tube feeding dependence. The purpose of this prospective cohort study was to develop a prediction model for tube feeding dependence 6 months (TUBEM6) after curative (chemo-) radiotherapy in HNC patients. PATIENTS AND METHODS: Tube feeding dependence was scored prospectively. To develop the multivariable model, a group LASSO analysis was carried out, with TUBEM6 as the primary endpoint (n = 427). The model was then validated in a test cohort (n = 183). The training cohort was divided into three groups based on the risk of TUBEM6 to test whether the model could be extrapolated to later time points (12, 18 and 24 months). RESULTS: Most important predictors for TUBEM6 were weight loss prior to treatment, advanced T-stage, positive N-stage, bilateral neck irradiation, accelerated radiotherapy and chemoradiation. Model performance was good, with an Area under the Curve of 0.86 in the training cohort and 0.82 in the test cohort. The TUBEM6-based risk groups were significantly associated with tube feeding dependence at later time points (p<0.001). CONCLUSION: We established an externally validated predictive model for tube feeding dependence after curative radiotherapy or chemoradiation, which can be used to predict TUBEM6

    The normalized Banzhaf value and the Banzhaf share function The Normalized Banzhaf Value and the Banzhaf Share Function THE NORMALIZED BANZHAF VALLTE AND THE BANZHAF SHARE FUNCTION

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    Abstract A cooperative game with transferable utilities -or simply a TU-game-describes a situation in which players can obtain certain payoffs by cooperation. A value function for these games is a function which assigns to every such a game a distribution of payoffs over the players in the game. A famous solution concept for TU-games is the Banzhaf value. This Banzhaf value is not efficient, i.e., in general it does not distribute the payoff that can be obtained by the &apos;grand coalition&apos; consisting of all players cooperating together. In this paper we consider the normalized Banzhaf value which distributes the payoff that can be obtained by the &apos;grand coalition&apos; proportional to the Banzhaf values of the players. This value does not satisfy certain axioms underlying the Banzhaf value. In this paper we discuss some characterizations of the normalized Banzhaf value and compare these with other solution concepts such as, for example, the (non-normalized) Banzhaf value and the Shapley value. Another approach to analyze efficient V&apos;cl,lue functions is to consider share functions being functions which assign to every player in a TU-game its share in the worth of the &apos;grand coalition&apos;. We discuss the characterization of a class of such share functions containing the Banzhaf and Shapley share functions. Finally, we generalize the concept of the potential function of a game as introduced by Hart and Mas-Colell to a class of potential functions and characterize any element of the class of share functions by the normalized marginal function of the corresponding potential function
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