The Egyptian Cardiothoracic Surgeon (ECTS - E-Journal)
Not a member yet
46902 research outputs found
Sort by
Hybrid Overlay/Underlay Cognitive Radio Network with MC-CDMA
No full textCognitive radio (CR) allows secondary users (SUs) to exploit the under-utilized radio spectrum of the primary networks. To fully utilize the primary spectrum and maximize the spectral efficiency, overlay and underlay transmissions, which exploit the white and grey spaces respectively, should be used together. However for underlay, the SUs need to transmit at low power to avoid causing harmful interference to the PUs, whereas the PUs will cause high interference to the SUs. Thus interference mitigation is a major issue in underlay spectrum utilization. In this paper, a hybrid transmission system that exploits both overlay and underlay is proposed using MC-CDMA due to its interference rejection and diversity exploitation capabilities. Unlike existing approaches, which separate the use of overlay and underlay spectrum, the proposed schemes utilize the entire spectrum for underlay transmission to minimize the PU interference while using the spectrum holes for overlay transmission to maximize data rate. Two techniques that operates at full-load and overload scenarios are proposed. The overload system is then extended to the multi-user underlay case to further improve the spectrum utilization
A third-person perspective on co-speech action gestures in Parkinson's disease.
No full textA combination of impaired motor and cognitive function in Parkinson's disease (PD) can impact on language and communication, with patients exhibiting a particular difficulty processing action verbs. Co-speech gestures embody a link between action and language and contribute significantly to communication in healthy people. Here, we investigated how co-speech gestures depicting actions are affected in PD, in particular with respect to the visual perspective-or the viewpoint - they depict. Gestures are closely related to mental imagery and motor simulations, but people with PD may be impaired in the way they simulate actions from a first-person perspective and may compensate for this by relying more on third-person visual features. We analysed the action-depicting gestures produced by mild-moderate PD patients and age-matched controls on an action description task and examined the relationship between gesture viewpoint, action naming, and performance on an action observation task (weight judgement). Healthy controls produced the majority of their action gestures from a first-person perspective, whereas PD patients produced a greater proportion of gestures produced from a third-person perspective. We propose that this reflects a compensatory reliance on third-person visual features in the simulation of actions in PD. Performance was also impaired in action naming and weight judgement, although this was unrelated to gesture viewpoint. Our findings provide a more comprehensive understanding of how action-language impairments in PD impact on action communication, on the cognitive underpinnings of this impairment, as well as elucidating the role of action simulation in gesture production
An analytical study of the electrochemical degradation of methyl orange using a novel polymer disk electrode
No full textThis study presents the degrdn. of methyl orange in a synthetic soln. using an electro-oxidn. technique. A novel polymer disk electrode was fabricated in this work using injection molding. Such an electrode is low cost, mass produced, and efficient to achieve a complete decolorization of methyl orange in the synthetic soln. The performance of the electrode was studied comprehensively. The degrdn. of methyl orange was accomplished in only 800 s. at optimum operating conditions of 0.1 M KCl electrolyte soln. and const. applied current of 5 mA. The results revealed that the degrdn. of dye follows an indirect electro oxidn. mechanism. It was also found that stirring is a crucial requirement to improve the mass transfer and to enhance the decolorization rate. The effect of changing the applied current, supporting electrolyte, electrolyte concn., and initial dye concn. were also investigated. [on SciFinder(R)
The longitudinal course of physical function in people with symptomatic knee osteoarthritis: Data from the MOST study and the OAI.
No full textBACKGROUND: Pain and functional decline are hallmarks of knee osteoarthritis (OA). Despite this, longitudinal studies unexpectedly reveal stable or improved physical function. The aim of this study was to impute missing and pre-total knee replacement (TKR) values to describe physical function over time among people with symptomatic knee OA. METHODS: We included participants from the Multicenter Osteoarthritis Study (MOST) and the Osteoarthritis Initiative (OAI) with incident symptomatic knee OA observed during the first 30 months in MOST and 36 months in OAI. WOMAC physical function (pf), the Five Times Sit To Stand Test, and the 20-Meter Walk Test were assessed over 4,5 and 6 years, respectively. We used a multiple imputation method for missing visits, and estimated pre-TKR values close to the time of TKR using a fitted local regression smoothing curve. In mixed effect models we investigated the physical function change over time using data before and after imputation and prediction of pre-TKR values. RESULTS: In MOST, 225 (8%) had incident knee OA, with corresponding 577 (12.7%) in OAI. After adjusting for pre-TKR values and imputing missing values, we found that WOMAC-pf values remained stable or slightly declined over time, and the 20-Meter Walk test results changed from stable in nonimputed analyses to worsening using imputed data. CONCLUSION: Data from the MOST Study and the OAI showed stable to worsening physical function over time in people with incident symptomatic knee OA after imputing missing values and adjusting pre-TKR values. This article is protected by copyright. All rights reserved
Actor-Network Theory Research:Four Volume Set
No full textActor Network Theory has grown into one of the most innovative and influential approaches for social science research. Originating in the field of science and technology studies with scholars Michel Callon, Bruno Latour and John Law, it is now used widely across the social sciences and beyond. In this four-volume collection, Richie Nimmo brings together defining research articles on Actor-Network Theory to chart its emergence, development and transformation over time, as well as its application in multiple fields
F-Split and F-Regular Varieties with a Diagonalizable Group Action
No full textLet H be a diagonalizable group over an algebraically closed fieldk of positive characteristic, and X a normal k-variety with an H-action. Undera mild hypothesis, e.g. H a torus or X quasiprojective, we construct a certainquotient log pair (Y,Δ) and show that X is F-split (F-regular) if and onlyif the pair (Y,Δ) if F-split (F-regular). We relate splittings of X compatiblewith H-invariant subvarieties to compatible splittings of (Y,Δ), as well asdiscussing diagonal splittings of X. We apply this machinery to analyze theF-splitting and F-regularity of complexity-one T-varieties and toric vectorbundles, among other example
Everolimus for the treatment of advanced, non-functional neuroendocrine tumours of the lung or gastrointestinal tract (RADIANT-4):a randomised, placebo-controlled, phase 3 study
No full textBACKGROUND: Effective systemic therapies for patients with advanced, progressive neuroendocrine tumours of the lung or gastrointestinal tract are scarce. We aimed to assess the efficacy and safety of everolimus compared with placebo in this patient population.METHODS: In the randomised, double-blind, placebo-controlled, phase 3 RADIANT-4 trial, adult patients (aged ≥18 years) with advanced, progressive, well-differentiated, non-functional neuroendocrine tumours of lung or gastrointestinal origin were enrolled from 97 centres in 25 countries worldwide. Eligible patients were randomly assigned in a 2:1 ratio by an interactive voice response system to receive everolimus 10 mg per day orally or identical placebo, both with supportive care. Patients were stratified by tumour origin, performance status, and previous somatostatin analogue treatment. Patients, investigators, and the study sponsor were masked to treatment assignment. The primary endpoint was progression-free survival assessed by central radiology review, analysed by intention to treat. Overall survival was a key secondary endpoint. This trial is registered with ClinicalTrials.gov, number NCT01524783.FINDINGS: Between April 3, 2012, and Aug 23, 2013, a total of 302 patients were enrolled, of whom 205 were allocated to everolimus 10 mg per day and 97 to placebo. Median progression-free survival was 11·0 months (95% CI 9·2-13·3) in the everolimus group and 3·9 months (3·6-7·4) in the placebo group. Everolimus was associated with a 52% reduction in the estimated risk of progression or death (hazard ratio [HR] 0·48 [95% CI 0·35-0·67], p<0·00001). Although not statistically significant, the results of the first pre-planned interim overall survival analysis indicated that everolimus might be associated with a reduction in the risk of death (HR 0·64 [95% CI 0·40-1·05], one-sided p=0·037, whereas the boundary for statistical significance was 0·0002). Grade 3 or 4 drug-related adverse events were infrequent and included stomatitis (in 18 [9%] of 202 patients in the everolimus group vs 0 of 98 in the placebo group), diarrhoea (15 [7%] vs 2 [2%]), infections (14 [7%] vs 0), anaemia (8 [4%] vs 1 [1%]), fatigue (7 [3%] vs 1 [1%]), and hyperglycaemia (7 [3%] vs 0).INTERPRETATION: Treatment with everolimus was associated with significant improvement in progression-free survival in patients with progressive lung or gastrointestinal neuroendocrine tumours. The safety findings were consistent with the known side-effect profile of everolimus. Everolimus is the first targeted agent to show robust anti-tumour activity with acceptable tolerability across a broad range of neuroendocrine tumours, including those arising from the pancreas, lung, and gastrointestinal tract.FUNDING: Novartis Pharmaceuticals Corporation.</p