An application of the Rasch model to reading comprehension measurement

An effective reading comprehension measurement demands robust psychometric tools that allow teachers and researchers to evaluate the educational practices and track changes in students’ performance. In this study, we illustrate how Rasch model can be used to attend such demands and improve reading comprehension measurement. We discuss the construction of two reading comprehension tests: TRC-n, with narrative texts, and TRC-e, with expository texts. Three vertically scaled forms were generated for each test (TRC-n-2, TRC-n-3, TRC-n-4; TRC-e-2, TRC-e-3 and TRC-e-4), each meant to assess Portuguese students in second, third and fourth grade of elementary school. The tests were constructed according to a nonequivalent groups with anchor test design and data were analyzed using the Rasch model. The results provided evidence for good psychometric qualities for each test form, including unidimensionality and local independence and adequate reliability. A critical view of this study and future researches are discussed.CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), PortugalThis research was supported by Grant FCOMP-01-0124-FEDER-010733 from Fundação para a Ciência e Tecnologia (FCT) and the European Regional Development Fund (FEDER) through the European program COMPETE (Operational Program for Competitiveness Factors) under the National Strategic Reference Framework (QREN).info:eu-repo/semantics/publishedVersio

Comparison of different treatments for isoniazid-resistant tuberculosis: an individual patient data meta-analysis

BACKGROUND: Isoniazid-resistant, rifampicin-susceptible (INH-R) tuberculosis is the most common form of drug resistance, and is associated with failure, relapse, and acquired rifampicin resistance if treated with first-line anti-tuberculosis drugs. The aim of the study was to compare success, mortality, and acquired rifampicin resistance in patients with INH-R pulmonary tuberculosis given different durations of rifampicin, ethambutol, and pyrazinamide (REZ); a fluoroquinolone plus 6 months or more of REZ; and streptomycin plus a core regimen of REZ. METHODS: Studies with regimens and outcomes known for individual patients with INH-R tuberculosis were eligible, irrespective of the number of patients if randomised trials, or with at least 20 participants if a cohort study. Studies were identified from two relevant systematic reviews, an updated search of one of the systematic reviews (for papers published between April 1, 2015, and Feb 10, 2016), and personal communications. Individual patient data were obtained from authors of eligible studies. The individual patient data meta-analysis was performed with propensity score matched logistic regression to estimate adjusted odds ratios (aOR) and risk differences of treatment success (cure or treatment completion), death during treatment, and acquired rifampicin resistance. Outcomes were measured across different treatment regimens to assess the effects of: different durations of REZ (≤6 months vs >6 months); addition of a fluoroquinolone to REZ (fluoroquinolone plus 6 months or more of REZ vs 6 months or more of REZ); and addition of streptomycin to REZ (streptomycin plus 6 months of rifampicin and ethambutol and 1–3 months of pyrazinamide vs 6 months or more of REZ). The overall quality of the evidence was assessed using GRADE methodology. FINDINGS: Individual patient data were requested for 57 cohort studies and 17 randomised trials including 8089 patients with INH-R tuberculosis. We received 33 datasets with 6424 patients, of which 3923 patients in 23 studies received regimens related to the study objectives. Compared with a daily regimen of 6 months of (H)REZ (REZ with or without isoniazid), extending the duration to 8–9 months had similar outcomes; as such, 6 months or more of (H)REZ was used for subsequent comparisons. Addition of a fluoroquinolone to 6 months or more of (H)REZ was associated with significantly greater treatment success (aOR 2·8, 95% CI 1·1–7·3), but no significant effect on mortality (aOR 0·7, 0·4–1·1) or acquired rifampicin resistance (aOR 0·1, 0·0–1·2). Compared with 6 months or more of (H)REZ, the standardised retreatment regimen (2 months of streptomycin, 3 months of pyrazinamide, and 8 months of isoniazid, rifampicin, and ethambutol) was associated with significantly worse treatment success (aOR 0·4, 0·2–0·7). The quality of the evidence was very low for all outcomes and treatment regimens assessed, owing to the observational nature of most of the data, the diverse settings, and the imprecision of estimates. INTERPRETATION: In patients with INH-R tuberculosis, compared with treatment with at least 6 months of daily REZ, addition of a fluoroquinolone was associated with better treatment success, whereas addition of streptomycin was associated with less treatment success; however, the quality of the evidence was very low. These results support the conduct of randomised trials to identify the optimum regimen for this important and common form of drug-resistant tuberculosis. FUNDING: World Health Organization and Canadian Institutes of Health Research

CAUSES OF UNCONTROLLED BLOOD PRESSURE IN THE OVER-65 POPULATION

Abstract&nbsp; INTRODUCTION: Hypertension is a major cause of cardiovascular disease and the prevalence of hypertension shows a linear increase with aging so that it increases by 10 percent every 10 years. This study was conducted to investigate the causes of uncontrolled blood pressure in people aged over 65 years. methods: This descriptive case-control study was conducted at Isfahan Amin Hospital in 2003 on two-hundred over-65 subjects diagnosed with hypertension through a routine travel check-up for Mecca pilgrimage. After medical examinations and blood pressure measurement according to WHO standards, the subjects were divided into a case group (controlled blood pressure) and a control group (uncontrolled blood pressure), respectively. A questionnaire was filled in for each subject and the data were analyzed with &chi;2 and t-student test. results: The case and control groups had mean ages of 70.7&plusmn;5.2 and 69.5&plusmn;4.9 years, respectively. In the case group, less than half of the subjects were taking their antihypertensive medications regularly and 12.5% engaged in self-therapy. Fifty-five percent of subjects in the case group expressed a lack of motivation as the reason for discontinuing therapy. Their knowledge and practice were also found to be significantly lower than the control group (P&lt;0.05). Discussion: In comparison with other studies, it was observed that the most common causes of uncontrolled blood pressure are poor knowledge, inappropriate practice in avoiding risk factors, and the discontinuation of pharmaceutical antihypertensive therapy.Keywords . Hypertension . Cardiovascular diseases . Antihypertensive agents . Diet therapy</p

The impact of acute and chronic aerobic and resistance exercise on stem cell mobilization: A review of effects in healthy and diseased individuals across different age groups

Stem cells (SCs) play a crucial role in tissue repair, regeneration, and maintaining physiological homeostasis. Exercise mobilizes and enhances the function of SCs. This review examines the effects of acute and chronic aerobic and resistance exercise on the population of SCs in healthy and diseased individuals across different age groups. Both acute intense exercise and moderate regular training increase circulating precursor cells CD34+ and, in particular, the subset of angiogenic progenitor cells (APCs) CD34+/KDR+. Conversely, chronic exercise training has conflicting effects on circulating CD34+ cells and their function, which are likely influenced by exercise dosage, the health status of the participants, and the methodologies employed. While acute activity promotes transient mobilization, regular exercise often leads to an increased number of progenitors and more sustainable functionality. Short interventions lasting 10–21 days mobilize CD34+/KDR + APCs in sedentary elderly individuals, indicating the inherent capacity of the body to rapidly activate tissue-reparative SCs during activity. However, further investigation is needed to determine the optimal exercise regimens for enhancing SC mobilization, elucidating the underlying mechanisms, and establishing functional benefits for health and disease prevention. Current evidence supports the integration of intense exercise with chronic training in exercise protocols aimed at activating the inherent regenerative potential through SC mobilization. The physical activity promotes endogenous repair processes, and research on exercise protocols that effectively mobilize SCs can provide innovative guidelines designed for lifelong tissue regeneration. An artificial neural network (ANN) was developed to estimate the effects of modifying elderly individuals and implementing chronic resistance exercise on stem cell mobilization and its impact on individuals and exercise. The network's predictions were validated using linear regression and found to be acceptable compared to experimental results

Assessing heat transfer and nanofluid laminar flow in the curved micro-mixers by adopting two-phase model

Micromixers are devices used for mixing fluids at the microscale level and are used for a variety of applications, including chemical reactions, mass transport, and heat transfer processes. In heat transfer processes, micromixers can enhance the heat transfer rate by creating a more homogeneous fluid mixture. In this research, the flow and heat transfer of a nanofluid are simulated in four different geometry of micromixers. The objective is to investigate which one has a better performance compared to a smooth microchannel with regard to the performance evaluation criterion (PEC), which proposes an evaluation with regard to the trade-off between heat transfer and pressure drop. For this purpose, the Ag/water nanofluid is simulated in micromixers of different geometries at Re numbers ranging from 200 to 800 and solid volume fractions (SVF) of 0, 2, and 4% using a finite volume method. The mixture model is adopted to simulate the nanofluid as a two-phase fluid, which is subjected to a laminar flow regime. The micromixers’ walls are exposed to constant heat flux. The effect of increasing the Re number and the SVF is assessed and compared in all geometries, and the results indicate that an increase in both these figures increases the PEC considerably. Moreover, the PEC for each case is assessed and compared, and the best and worst geometry in terms of heat transfer as well as pressure drop are presented. Specifically, in the best case with the highest PEC at the Re = 800 and SVF = 4%, the Nu number is increased by 2.3 fold while its pressure drop is increased by 1.42 fold compared to a smooth microchannel

Do metal artifact reduction algorithms influence the detection of implant-related injuries to the inferior alveolar canal in CBCT images?

Abstract Background The routine application of dental implants for replacing missing teeth has revolutionized restorative and prosthetic dentistry. However, cone beam computed tomography (CBCT) evaluations of structures adjacent to the implants are limited by metal artifacts. There are several methods for reducing metal artifacts, but this remains a challenging task. This study aimed to examine the effectiveness of metal artifact reduction (MAR) algorithms in identifying injuries of implants to the inferior alveolar canal in CBCT images. Method In this in vitro study, mono-cortical bone windows were created and the inferior alveolar canal was revealed. Using 36 implants, pilot drill and penetration damage of the implant tip into the canal was simulated and compared to the control implants with distance from the canal. CBCT images were evaluated by four experienced observers with and without the MAR algorithm and compared to direct vision as the gold standard. The values of accuracy, sensitivity, and specificity were obtained and compared by receiver operating characteristic (ROC) curve (α = 0.05). Result The area under the ROC curve values for detection of pilot drill injuries varied between 0.840–0.917 and 0.639–0.854 in the active and inactive MAR conditions, respectively. The increase in ROC area was only significant for one of the observers (P = 0.010). For diagnosing penetrative injuries, the area under the ROC curve values was between 0.990–1.000 and 0.722–1.000 in the active and inactive MAR conditions, respectively. The improvement of ROC curve values in active MAR mode was only significant for one of the observers (P = 0.006). Conclusion Activation of MAR improved the diagnostic values of CBCT images in detecting both types of implant-related injuries to the inferior alveolar canal. However, for most observers, this increase was not statistically significant

OBESITY AND ITS ASSOCIATION WITH OTHER CARDIOVASCULAR RISK FACTORS IN WOMEN IN CENTRAL IRAN - WOMEN'S HEALTHY HEART PROJECT

Abstract&nbsp; INTRODUCTION: Cardiovascular diseases (CVD) are considered the most important cause of death worldwide. Obesity is a major CVD risk factor. This study was conducted to evaluate the prevalence of obesity and its association with other CVD risk factors in Iranian women. methods: This cross-sectional study was conducted in 2001 as part of Isfahan Healthy Heart Program (IHHP) in three Central Iranian cities of Isfahan, Najaf-Abad and Arak. Being over 19 years of age, absence of pregnancy, absence of mental retardation and Iranian nationality were the criteria for inclusion in the study. A questionnaire on demographics characteristics, drug consumption, smoking status, and physical activity were filled out for every subject. Height, weight and blood pressure of all subjects were measured and fasting blood samples were taken to measure blood glucose and lipids. The data were analyzed with T-test, &chi;2 and multiple linear regression, using SPSS11. results: Of 6391 women aged 38.8&plusmn;14.5 years participating in the study, 79% lived in the urban areas and 21% in the rural areas. The prevalence of a higher BMI was greater in urban areas in all ages. Hypertension, diabetes, total cholesterol-triglyceride and LDL-C disorders and inadequate physical activity were more prevalent in obese women than normal ones, but no significant difference was seen in HDL-C disorder and smoking between the two groups (P&lt;0.05). There was a significant positive relationship between BMI and age, blood glucose and urban residence, and a negative relationship was observed between BMI and inadequate physical activity (P&lt;0.05). Discussion: The high prevalence of obesity and the major risk factors of cardiovascular diseases in urban areas is testament to unhealthy lifestyle and insufficient physical activity of women in areas studied.Keywords . Women . Obesity . Residence . Risk factor</p

Application of scaled boundary finite element method in failure probability estimation of square nanographene sheet

In recent years, so much attention has been drawn to the field of nano computational material science. Due to the extensive applications of nanographene sheets in various industries such as aerospace industry, fracture analysis of square nanographene sheets is of crucial importance. Stochastic analysis is widely applied in fracture mechanics because it helps the results to be more realistic. In the present work, probabilistic fracture analysis of nanographene sheets is done using scaled boundary finite element (SBFEM) that is a novel semi-analytical method. In order to apply the stochastic method, we need to select certain statistical parameters, the ones considered here include crack length and failure stress. The results using the stochastic response method are compared with those of the Monte Carlo, which shows good agreement. Average, variance, third and fourth moments of stress and the fracture probability are calculated for all the bonds in two states of crack angle 0°, 90°. The results indicate that the maximum crack-tip fracture probability for central crack θ = 90° is 95%, while for θ = 0° equals 58%. For central crack θ = 90°, the failure probability in crack tip bonds, bonds adjacent to the crack edge and other bonds equal 95%, 88% and 65%, respectively. For nanographene sheet having the central crack θ = 90°, probabilistic density function is Gaussian, which reaches the highest point at the displacement being 0.990 pm. The third moment of the stress turned out to be zero, which shows that the input uncertain variables are all normal. The results obtained from computing the failure probability of all the bonds indicates that the highest failure probability is in the tip and edges of the crack. The stochastic fracture sensitivity versus crack length is calculated which shows that the maximum sensitivity in central crack happens when θ = 90° and crack length ranges between 0.3 and 0.4