24 research outputs found

    Learning Minimal and Maximal Rules from Observations of Graph Transformations

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    Graph transformations have been used to model services and systems where rules describe pre and post conditions of operations changing a complex state. However, despite their intuitive nature, creating such models is a time-consuming and error-prone process. In this paper we investigate the possibility of extracting rules from observations of transformations, i.e., pairs of input and output graphs resulting from successful transformations and individual input graphs were they have failed. From such positive and negative examples, minimal rules are extracted, to be extended by context that is present in all positive examples and missing in at least one negative example. The result is are a maximal and a required rule, jointly with the minimal rule deïŹning the range of possible rules that could have created the observed transformations. We report on an implementation of the approach, evaluate its accuracy, scalability and limitations, and discuss applications to reverse engineering visual constructs from observations of object states of components under test

    Insomnia in chronic renal patients on dialysis in Saudi Arabia

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    <p>Abstract</p> <p>Background</p> <p>Studies have shown that insomnia is a common sleep disorder among patients with end-stage renal disease (ESRD). This study aimed to assess the prevalence of insomnia in Saudi patients with ESRD who are on maintenance dialysis.</p> <p>Methods</p> <p>This was an observational cross-sectional study carried out over a period of five months in two hemodialysis centers in Saudi Arabia. To assess the prevalence of insomnia, we used the ICSD-2 definition. We also examined the association between insomnia and other sleep disorders, the underlying causes of renal failure, dialysis duration, dialysis shift, and other demographic data.</p> <p>Results</p> <p>Out of 227 enrolled patients, insomnia was reported by 60.8%. The mean patient age was 55.7 ± 17.2 years; 53.7% were male and 46.3% were female. Insomnia was significantly associated with female gender, afternoon hemodialysis, Restless Legs Syndrome, high risk for obstructive Sleep Apnea Syndrome and excessive daytime sleepiness (<it><b>P-values: </b></it>0.05, 0.01, < 0.0001, < 0.0001, and < 0.0001, respectively). No significant association was found between insomnia and other variables, including BMI, smoking habits, underlying etiology of renal failure, dialysis duration, association with hemoglobin, ferritin, and phosphorus or dialysis adequacy as measured by the Kt/V index.</p> <p>Conclusion</p> <p>Insomnia is common in dialysis patients and was significantly associated with other sleep disorders. Greater attention needs to be given to the care of dialysis patients with regard to the diagnosis and management of insomnia and associated sleep disorders.</p

    Loss-of-function mutations in UDP-Glucose 6-Dehydrogenase cause recessive developmental epileptic encephalopathy

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    AbstractDevelopmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids. Consistent with being loss-of-function alleles, we show using patients’ primary fibroblasts and biochemical assays, that these mutations either impair UGDH stability, oligomerization, or enzymatic activity. In vitro, patient-derived cerebral organoids are smaller with a reduced number of proliferating neuronal progenitors while mutant ugdh zebrafish do not phenocopy the human disease. Our study defines UGDH as a key player for the production of extracellular matrix components that are essential for human brain development. Based on the incidence of variants observed, UGDH mutations are likely to be a frequent cause of recessive epileptic encephalopathy.</jats:p

    Loss-of-function mutations in UDP-Glucose 6-Dehydrogenase cause recessive developmental epileptic encephalopathy

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    Developmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids. Consistent with being loss-of-function alleles, we show using patients’ primary fibroblasts and biochemical assays, that these mutations either impair UGDH stability, oligomerization, or enzymatic activity. In vitro, patient-derived cerebral organoids are smaller with a reduced number of proliferating neuronal progenitors while mutant ugdh zebrafish do not phenocopy the human disease. Our study defines UGDH as a key player for the production of extracellular matrix components that are essential for human brain development. Based on the incidence of variants observed, UGDH mutations are likely to be a frequent cause of recessive epileptic encephalopathy

    Impact of empirical antimicrobial therapy on the outcome of critically ill patients with Acinetobacter bacteremia

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    Rationale: Empirical antimicrobial therapy (EAT) for Acinetobacter infections may not be appropriate as it tends to be multidrug-resistant. This study evaluated the relationship between appropriate EAT and the outcomes of Intensive Care Unit (ICU) patients with Acinetobacter bacteremia. Methods: This is a retrospective study of patients admitted to a medical-surgical ICU (2005-2010) and developed Acinetobacter bacteremia during the stay. Patients were categorized according to EAT appropriateness, defined as administration of at least one antimicrobial agent to which the Acinetobacter was susceptible before susceptibility results were known. The relation between EAT appropriateness and outcomes was evaluated. Results: Sixty patients developed Acinetobacter bacteremia in the 6-year period (age = 50 ± 19 years; 62% males; Acute Physiology and Chronic Health Evaluation II score = 28 ± 9; 98.3% with central lines; 67% in shock and 59% mechanically ventilated) on average on day 23 of ICU and day 38 of hospital stay. All isolates were resistant to at least three of the tested antimicrobials. Appropriate EAT was administered to 60% of patients, mostly as intravenous colistin. Appropriate EAT was associated with lower ICU mortality risk (odds ratio: 0.15; 95% confidence interval: 0.03-0.96) on multivariate analysis. Conclusions: In this 6-year cohort, Acinetobacter bacteremia was related to multidrug-resistant strains. Appropriate EAT was associated with decreased ICU mortality risk

    Constructing a question bank based on script concordance approach as a novel assessment methodology in surgical education

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    Abstract Background Script Concordance Test (SCT) is a new assessment tool that reliably assesses clinical reasoning skills. Previous descriptions of developing SCT-question banks were merely subjective. This study addresses two gaps in the literature: 1) conducting the first phase of a multistep validation process of SCT in Plastic Surgery, and 2) providing an objective methodology to construct a question bank based on SCT. Methods After developing a test blueprint, 52 test items were written. Five validation questions were developed and a validation survey was established online. Seven reviewers were asked to answer this survey. They were recruited from two countries, Saudi Arabia and Canada, to improve the test’s external validity. Their ratings were transformed into percentages. Analysis was performed to compare reviewers’ ratings by looking at correlations, ranges, means, medians, and overall scores. Results Scores of reviewers’ ratings were between 76% and 95% (mean 86% ± 5). We found poor correlations between reviewers (Pearson’s: +0.38 to −0.22). Ratings of individual validation questions ranged between 0 and 4 (on a scale 1–5). Means and medians of these ranges were computed for each test item (mean: 0.8 to 2.4; median: 1 to 3). A subset of test items comprising 27 items was generated based on a set of inclusion and exclusion criteria. Conclusion This study proposes an objective methodology for validation of SCT-question bank. Analysis of validation survey is done from all angles, i.e., reviewers, validation questions, and test items. Finally, a subset of test items is generated based on a set of criteria.</p

    Constructing a question bank based on script concordance approach as a novel assessment methodology in surgical education

    No full text
    Abstract Background Script Concordance Test (SCT) is a new assessment tool that reliably assesses clinical reasoning skills. Previous descriptions of developing SCT-question banks were merely subjective. This study addresses two gaps in the literature: 1) conducting the first phase of a multistep validation process of SCT in Plastic Surgery, and 2) providing an objective methodology to construct a question bank based on SCT. Methods After developing a test blueprint, 52 test items were written. Five validation questions were developed and a validation survey was established online. Seven reviewers were asked to answer this survey. They were recruited from two countries, Saudi Arabia and Canada, to improve the test’s external validity. Their ratings were transformed into percentages. Analysis was performed to compare reviewers’ ratings by looking at correlations, ranges, means, medians, and overall scores. Results Scores of reviewers’ ratings were between 76% and 95% (mean 86% ± 5). We found poor correlations between reviewers (Pearson’s: +0.38 to −0.22). Ratings of individual validation questions ranged between 0 and 4 (on a scale 1–5). Means and medians of these ranges were computed for each test item (mean: 0.8 to 2.4; median: 1 to 3). A subset of test items comprising 27 items was generated based on a set of inclusion and exclusion criteria. Conclusion This study proposes an objective methodology for validation of SCT-question bank. Analysis of validation survey is done from all angles, i.e., reviewers, validation questions, and test items. Finally, a subset of test items is generated based on a set of criteria

    Determinants of COVID-19 vaccine acceptance and hesitancy: a cross-sectional study in Saudi Arabia

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    Several COVID-19 vaccines have been developed in unprecedented time by research centers and pharmaceutical companies. This study aimed to determine COVID-19 vaccine acceptance and hesitancy rates and investigated the factors that influence vaccine acceptance and hesitancy. A cross-sectional research was conducted among adults in Saudi Arabia between January and March 2021 to determine willingness to receive a COVID-19 vaccine. A self-administered questionnaire was designed to explore the participants’ COVID-19 vaccine acceptance and hesitancy. Categorical variables are described by frequency and percentage. A cross-tabulation analysis using the chi-squared test was performed to find associations between sociodemographic characteristics and vaccine acceptance and hesitancy. Logistic regression analysis was performed for variables that were found to be significant by the chi-squared test. A descriptive analysis of the 531 participants showed that 61.8% were willing to get the COVID-19 vaccine, while 38.2% were not. COVID-19 vaccine hesitancy was higher among women (44.9%), those 34–49 years of age (47.9%), those who were married (41.9%), employed (39.7%), had lower educational attainment (40%), and urban dwellers (40.8%). The main reason for COVID-19 vaccine acceptance was to protect oneself and others, while concerns about vaccine safety were the main reason for vaccine hesitancy. Statically significant associations were found between vaccine acceptance and age (p = .002) and gender (p = .03). Our study revealed a high prevalence of COVID-19 vaccine hesitancy (38.2%). Several sociodemographic characteristics were related to hesitancy, which may hinder the promotion of vaccine uptake. Public health campaigns is recommended to promote COVID-19 vaccine uptake
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