1,635 research outputs found
AN EXAMINATION OF IRANIAN EFL LEARNER TRANSLATORS' PROBLEMS IN TRANSLATION ACTIVITIES
The research reported here was an attempt to understand the nature of classroom translation problems of Iranian EFL learners. For this purpose, three cohorts of EFL learners taking introductory and advanced translation courses (from English to Persian and vice versa)participated in the study in order to identify the sources of their translation problems and offer solutions for the betterment of the situation. The content analysis of the samples of translationactivities of the participants revealed that translation is a more sophisticated skill than expected and that an inappropriate linguistic competence in English is responsible for the bulk of translation blunders faced by learner translators
Scalable rekeying algorithm in IEEE 802.16e
IEEE 802.16e standard provides wide coverage and high bandwidth for subscribers in a metropolitan area network. It introduces Multicast and Broadcast Rekeying Algorithm (MBRA) which is a multicasting scheme to communicate with many users concurrently. Although ELAPSE (for Efficient sub-Linear rekeying Algorithm with Perfect SEcrecy) improves on the deficiencies of MBRA, the algorithm poorly responds to scalability issue. This paper proposes a Scalable Rekeying Algorithm (SRA) based on a complete binary tree structure. SRA is introduced with linear linked list structure in order to make the system more scalable. Evaluation analysis shows that SRA manages to improve the scalability issue in MBRA for Mobile WiMAX
The Study of Abnormal Liver Ultrasound Findings in Candidate Patients Undergoing Renal Transplantation from Brain Dead Donors
BACKGROUND AND OBJECTIVE: Chronic kidney disease in addition to kidney involvement may cause abnormalities in various systems of the body, in which liver disorders are one of the most commonly encountered disorders. Failure to identify some of these disorders can cause a serious problem in transolant patient. This study was performed to determine the frequency and type of abnormal liver ultrasound findings in renal transplant patients.
METHODS: In this cross-sectional study, recorded data of 480 kidney failure patients who had received kidney transplant from brain death donors during the last 6 years in three Mashhad hospitals were investigated. Ultrasonography was considered before the transplant and abnormal liver findings were recorded in a checklist and were assesed.
FINDINGS: The mean age was 39.07±12.67 years of which 52.70% were male and 42.30% were female. Liver disorders were observed in 13.12% of patients. The highest prevalence was related to fatty liver grade I (2.5%), grade II (1.46%), gallstone (1.25%) and liver cysts (1.25%).
CONCLUSION: The results of the study showed that liver asymptomatic disorders in renal transplant patients have significant prevalence and because some of these disorders require treatment before transplantation, enough attention to screening before transplantation can help to prevent post-transplant complications
The application of predictive modelling for determining bio-environmental factors affecting the distribution of blackflies (Diptera: Simuliidae) in the Gilgel Gibe watershed in Southwest Ethiopia
Blackflies are important macroinvertebrate groups from a public health as well as ecological point of view. Determining the biological and environmental factors favouring or inhibiting the existence of blackflies could facilitate biomonitoring of rivers as well as control of disease vectors. The combined use of different predictive modelling techniques is known to improve identification of presence/absence and abundance of taxa in a given habitat. This approach enables better identification of the suitable habitat conditions or environmental constraints of a given taxon. Simuliidae larvae are important biological indicators as they are abundant in tropical aquatic ecosystems. Some of the blackfly groups are also important disease vectors in poor tropical countries. Our investigations aim to establish a combination of models able to identify the environmental factors and macroinvertebrate organisms that are favourable or inhibiting blackfly larvae existence in aquatic ecosystems. The models developed using macroinvertebrate predictors showed better performance than those based on environmental predictors. The identified environmental and macroinvertebrate parameters can be used to determine the distribution of blackflies, which in turn can help control river blindness in endemic tropical places. Through a combination of modelling techniques, a reliable method has been developed that explains environmental and biological relationships with the target organism, and, thus, can serve as a decision support tool for ecological management strategies
Graphical Markov models, unifying results and their interpretation
Graphical Markov models combine conditional independence constraints with
graphical representations of stepwise data generating processes.The models
started to be formulated about 40 years ago and vigorous development is
ongoing. Longitudinal observational studies as well as intervention studies are
best modeled via a subclass called regression graph models and, especially
traceable regressions. Regression graphs include two types of undirected graph
and directed acyclic graphs in ordered sequences of joint responses. Response
components may correspond to discrete or continuous random variables and may
depend exclusively on variables which have been generated earlier. These
aspects are essential when causal hypothesis are the motivation for the
planning of empirical studies.
To turn the graphs into useful tools for tracing developmental pathways and
for predicting structure in alternative models, the generated distributions
have to mimic some properties of joint Gaussian distributions. Here, relevant
results concerning these aspects are spelled out and illustrated by examples.
With regression graph models, it becomes feasible, for the first time, to
derive structural effects of (1) ignoring some of the variables, of (2)
selecting subpopulations via fixed levels of some other variables or of (3)
changing the order in which the variables might get generated. Thus, the most
important future applications of these models will aim at the best possible
integration of knowledge from related studies.Comment: 34 Pages, 11 figures, 1 tabl
Exploring the Impact of Electrode Microstructure on Redox Flow Battery Performance Using a Multiphysics Pore Network Model
The redox flow battery is a promising energy storage technology for managing the inherent uncertainty of renewable energy sources. At present, however, they are too expensive and thus economically unattractive. Optimizing flow batteries is thus an active area of research, with the aim of reducing cost by maximizing performance. This work addresses microstructural electrode optimizations by providing a modeling framework based on pore-networks to study the multiphysics involved in a flow battery, with a specific focus on pore-scale structure and its impact on transport processes. The proposed pore network approach was extremely cheap in computation cost (compared to direct numerical simulation) and therefore was used for parametric sweeps to search for optimum electrode structures in a reasonable time. It was found that that increasing porosity generally helps performance by increasing the permeability and flow rate at a given pressure drop, despite reducing reactive surface area per unit volume. As a more nuanced structural study, it was found that aligning fibers in the direction of flow helps performance by increasing permeability but showed diminishing returns beyond slight alignment. The proposed model was demonstrated in the context of a hydrogen bromine flow battery but could be applied to any system of interest
Common carotid intima media thickness and ankle-brachial pressure index correlate with local but not global atheroma burden:a cross sectional study using whole body magnetic resonance angiography
Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA).50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50-70%, 3 = 70-99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated.The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045), however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β -0.39, p = 0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45), while the correlation between ABPI and atheroma burden persisted (β -0.45 p = 0.005).ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral arterial disease. However this is primarily due to a strong correlation with ilio-femoral atheroma burden
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