911 resultados para Page and stage


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This paper proposes a hybrid transmission technique based on adaptive code-to-user allocation and linear precoding for the downlink of phase shift keying (PSK) based multi-carrier code division multiple access (MC-CDMA) systems. The proposed scheme is based on the separation of the instantaneous multiple access interference (MAI) into constructive and destructive components taking into account the dependency on both the channel variation and the instantaneous symbol values of the active users. The first stage of the proposed technique is to adaptively distribute the available spreading sequences to the users on a symbol-by-symbol basis in the form of codehopping with the objective to steer the users' instantaneous crosscorrelations to yield a favourable constructive to destructive MAI ratio. The second stage is to employ a partial transmitter based zero forcing (ZF) scheme specifically designed for the exploitation of constructive MAI. The partial ZF processing decorrelates destructive interferers, while users that interfere constructively remain correlated. This results in a signal to interference-plus-noise ratio (SINR) enhancement without the need for additional power-per-user investment. It will be shown in the results section that significant bit error rate (BER) performance benefits can be achieved with this technique.

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Purpose: Current prognostic factors are poor at identifying patients at risk of disease recurrence after surgery for stage II colon cancer. Here we describe a DNA microarray-based prognostic assay using clinically relevant formalin-fixed paraffin-embedded (FFPE) samples. Patients and Methods: A gene signature was developed from a balanced set of 73 patients with recurrent disease (high risk) and 142 patients with no recurrence (low risk) within 5 years of surgery. Results: The 634-probe set signature identified high-risk patients with a hazard ratio (HR) of 2.62 (P <.001) during cross validation of the training set. In an independent validation set of 144 samples, the signature identified high-risk patients with an HR of 2.53 (P <.001) for recurrence and an HR of 2.21 (P = .0084) for cancer-related death. Additionally, the signature was shown to perform independently from known prognostic factors (P <.001). Conclusion: This gene signature represents a novel prognostic biomarker for patients with stage II colon cancer that can be applied to FFPE tumor samples. © 2011 by American Society of Clinical Oncology.

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The development of methods providing reliable estimates of demographic parameters (e. g., survival rates, fecundity) for wild populations is essential to better understand the ecology and conservation requirements of individual species. A number of methods exist for estimating the demographics of stage-structured populations, but inherent mathematical complexity often limits their uptake by conservation practitioners. Estimating survival rates for pond-breeding amphibians is further complicated by their complex migratory and reproductive behaviours, often resulting in nonobservable states and successive cohorts of eggs and tadpoles. Here we used comprehensive data on 11 distinct breeding toad populations (Bufo calamita) to clarify and assess the suitability of a relatively simple method [the Kiritani-Nakasuji-Manly (KNM) method] to estimate the survival rates of stage-structured populations with overlapping life stages. The study shows that the KNM method is robust and provides realistic estimates of amphibian egg and larval survival rates for species in which breeding can occur as a single pulse or over a period of several weeks. The study also provides estimates of fecundity for seven distinct toad populations and indicates that it is essential to use reliable estimates of fecundity to limit the risk of under- or overestimating the survival rates when using the KNM method. Survival and fecundity rates for B. calamita populations were then used to define population matrices and make a limited exploration of their growth and viability. The findings of the study recently led to the implementation of practical conservation measures at the sites where populations were most vulnerable to extinction. © 2010 The Society of Population Ecology and Springer.

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Purpose: In ischemic retinopathies, the misdirection of reparative angiogenesis away from the hypoxic retina leads to pathologic neovascularization. Thus, therapeutic strategies that reverse this trend would be extremely beneficial. Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) is an important mediator of vascular endothelial growth factor (VEGF) function facilitating vascular growth and maturation. However, in addition to NO, eNOS can also produce superoxide (O), exacerbating pathology. Here, our aim was to investigate the effect of eNOS overexpression on vascular closure and subsequent recovery of the ischemic retina.

Methods: Mice overexpressing eNOS-GFP were subjected to oxygen-induced retinopathy (OIR) and changes in retinal vascularization quantified. Background angiogenic drive was assessed during vascular development and in aortic rings. NOS activity was measured by Griess assay or conversion of radiolabeled arginine to citrulline, nitrotyrosine (NT), and superoxide by immunolabeling and dihydroethidium fluorescence and VEGF by ELISA.

Results: In response to hyperoxia, enhanced eNOS expression led to increased NOS-derived superoxide and dysfunctional NO production, NT accumulation, and exacerbated vessel closure associated with tetrahydrobiopterin (BH) insufficiency. Despite worse vaso-obliteration, eNOS overexpression resulted in elevated hypoxia-induced angiogenic drive, independent of VEGF production. This correlated with increased vascular branching similar to that observed in isolated aortas and during development. Enhanced recovery was also associated with neovascular tuft formation, which showed defective NO production and increased eNOS-derived superoxide and NT levels.

Conclusions: In hyperoxia, reduced BH bioavailability causes overexpressed eNOS to become dysfunctional, exacerbating vaso-obliteration. In the proliferative phase, however, eNOS has important prorepair functions enhancing angiogenic growth potential and recovery in ischemia. © 2012 The Association for Research in Vision and Ophthalmology, Inc.

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Esophageal adenocarcinoma (EA) is increasingly common among patients with Barrett's esophagus (BE). We aimed to provide consensus recommendations based on the medical literature that clinicians could use to manage patients with BE and low-grade dysplasia, high-grade dysplasia (HGD), or early-stage EA.

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EUROCHIP (European Cancer Health Indicators Project) focuses on understanding inequalities in the cancer burden, care and survival by the indicators "stage at diagnosis," "cancer treatment delay" and "compliance with cancer guidelines" as the most important indicators. Our study aims at providing insight in whether cancer registries collect well-defined variables to determine these indicators in a comparative way. Eighty-six general European population-based cancer registries (PBCR) from 32 countries responded to the questionnaire, which was developed by EUROCHIP in collaboration with ENCR (European Network of Cancer Registries) and EUROCOURSE. Only 15% of all the PBCR in EU had all three indicators available. The indicator "stage at diagnosis" was gathered for at least one cancer site by 81% (using TNM in 39%). Variables for the indicator "cancer treatment delay" were collected by 37%. Availability of type of treatment (30%), surgery date (36%), starting date of radiotherapy (26%) and starting date of chemotherapy (23%) resulted in 15% of the PBCRs to be able to gather the indicator "compliance to guidelines". Lack of data source access and qualified staff were the major reasons for not collecting all the variables. In conclusion, based on self-reporting, a few of the participating PBCRs had data available which could be used for clinical audits, evaluation of cancer care projects, survival and for monitoring national cancer control strategies. Extra efforts should be made to improve this very efficient tool to compare cancer burden and the effects of the national cancer plans over Europe and to learn from each other. © 2012 UICC.

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This essay investigates an intricate drama of cultural identity in performances of Shakespeare on the nineteenth-century Melbourne stage. It considers the rivalry between Charles and Ellen Kean and their competitor, Barry Sullivan, for the two-month period in 1863 during which their Australian tours overlapped. This Melbourne Shakespeare war was anticipated,augmented, and richly documented in Melbourne’s papers: The Age, The Argus and Melbourne Punch. This essay pursues two seams of inquiry. The first is an investigation of the discourses of cultural and aesthetic value laced through the language of reviews of their Shakespearean roles.The essay identifies how reviewers register affective engagement with the performers in these roles, and suggests how the roles themselves reflected, by accident or design, the terms of the dispute. The second is concerned with the national identity of the actors. Kean, although born in Waterford, Ireland, had held the post of Queen Victoria’s Master of the Revels and identified himself as English. Sullivan, although born in Birmingham, was of Cork parentage and was identified as Irish by both his supporters and his detractors. This essay tracks the development of the actors’ national and artistic identities established prior to Melbourne and ask how they played out on in the context of the particularities of Australian reception. It shows that, in this instance, these actors were implicated in complex debates over national authority and cultural ownership.

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Objective: The purpose of this study was to estimate costs and quality of life (QoL) of late-stage glaucoma patients in 4 European countries. Methods: Retrospective review of medical charts of patients with POAG who were followed in a low-vision or vision rehabilitation center in one of 4 countries for at least 1 year was used to determine patient characteristics, health status, and health care resource use. Visual impairment was measured by best-corrected visual acuity (Snellen score). Patients were also interviewed over the telephone in order to assess their health-related QoL (using EuroQol EQ-5D) and use of resources including: the number of visits to rehabilitation centers, visits to hospital and non-hospital specialists, the use of low-vision devices, medication, tests, and the use of hired home help. The costs associated with resource use were calculated from the perspective of a third-party payer of health and social care based on resource usage and unit costs in each country. Results: Patients undergoing visual rehabilitation in France (n=21), Denmark (n=59), Germany (n=60), and the United Kingdom (n=22) were identified, interviewed and had their medical charts reviewed. Annual maintenance costs of late-stage glaucoma amounted to €830 (±445) on average. Average home help costs were more than 3 times higher. QoL, on average, was 0.65 (±0.28). QoL was positively correlated with the level of visual acuity in the patients' best eye. On the other hand, visual acuity was also positively correlated to health care costs, but negatively correlated to costs of home help. Conclusions: The study was limited by its observational, uncontrolled design. The finding that late-stage glaucoma is associated with higher home help costs than health care maintenance costs suggests that potential savings from a better preventive treatment are to be found for social care payers rather than health care payers. © 2008 Informa UK Ltd All rights reserved.

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Introduction: Cachexia is a major cause of morbidity and mortality in people who have end-stage renal disease (ESRD). The majority of research into cachexia in ESRD has focused on the biological aspects of the syndrome and potential treatment modalities. While this research is necessary, it predominately focuses on the physical impact of cachexia in ESRD. The multi-dimensional psychosocial ramifications of this syndrome have been highlighted in other end-stage illness trajectories, but have not been systematically explored in persons who have ESRD. Aim: This paper discusses why this research is necessary, alongside further studies to help define the pathophysiology of this syndrome. Conclusion: The rich insightful data gained from understanding the patients' illness experience will positively contribute to the limited knowledge base available and inform future holistic patient-centred care delivery which recognises and responds to not only the biological but also the psychosocial impact of cachexia. © 2013 European Dialysis and Transplant Nurses Association/European Renal Care Association.

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