Using latent transition analysis to identify effects of an intelligent tutoring system on reading comprehension of seventh-grade students

Latent transition analysis (LTA) was conducted on data from a recent cluster randomized controlled study of 1808 seventh-grade students’ use of a web-based intelligent tutoring system (ITSS). This analysis goes beyond traditional variable-centered methods to focus on profiles of learners and changes in reading class membership between pre- and post-tests for students with and without receiving ITSS intervention. A four-class model was obtained, consisting of poor readers (class 1), delayed readers (class 2), proficient readers (class 3), and readers with specific deficits in problem and solution (class 4). Analysis showed that students receiving the ITSS intervention were more likely than students without the intervention to transition into the proficient class regardless of their initial reading performance profiles. However, the odds ratio of transitioning into the proficient class (as opposed to staying in the same class) in the ITSS condition, compared to the control, was the highest (4.29) for initial readers with deficits in problem and solution, followed by initial poor readers (1.66) and initial delayed readers (1.50). Findings indicated that students in the ITSS condition had larger reading improvement than students in the control condition, particularly for readers with initial deficits in problem and solution.     

Diagnosis and treatment of reading disabilities based on the component model of reading: an alternative to the discrepancy model of LD

Currently, learning disabilities (LD) are diagnosed on the basis of the discrepancy between students' IQ and reading achievement scores. Students diagnosed with LD often receive remedial instruction in resource rooms. The available evidence suggests that the educational policy based on this discrepancy model has not yielded satisfactory results. This has led researchers to try other paradigms, such as the component model and response to intervention, for dealing with children with reading disabilities. The component model of reading (CMR) described in the present article identifies the reading component that is the source of reading difficulty and targets instruction at that component. Study 1 describes the CMR and reports on its validity. Study 2 describes the successful outcome of a 7-year CMR-based reading instruction program. Compared to the discrepancy model, the CMR has demonstrated several advantages.     

Evolutionary biology today

“For a biologist”, wrote Sir Peter Medawar, “the alternative to thinking in evolutionary terms is not to think at all”. Yet, at the end of an education in biology in most Indian universities, this is not quite the view of evolutionary biology that one is left with. Evolution is presented summarily, almost as a footnote, rather than as a vital branch of biology providing the conceptual foundation for our modern views about the living world. In this issue ofResonance, we remember Stephen Jay Gould, who wrote extensively and eloquently about evolution for a general audience. It seems fitting, then, to also briefly discuss why evolutionary biology is important, not only conceptually but also in terms of practical applications. In this first part of a series of articles on modern evolutionary biology, we examine why the idea of evolution is so important in our intellectual history, and also take a look at the domain of evolutionary biology as a discipline. Amitabh Joshi studies and teaches evolutionary genetics and population ecology at the Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore. His current research interests are in life-history, evolution, the evolutionary genetics of biological clocks, the evolution of ecological specialization dynamics. He also enjoys music (especially traditional qawali in Braj, Farsi, Punjabi and Urdu), history, philosophy, and reading and writing poetry in Urdu, Hindi and English.     

Hardy-Weinberg equilibrium and the foundations of evolutionary genetics 2. The inertial state in population genetics

The year 2008 marks the 100th anniversary of the enunciation of the principle defining the inertial state of populations from a genetic viewpoint through the independent publication of papers on the topic by G H Hardy and W Weinberg. In this part, we formally build up the model that underlies the Hardy-Weinberg Equilibrium, as well as its mathematical representation.     

Metabolic Syndrome in Childhood: Rare Case of Alstrom Syndrome with Blindness

Alstrom’s syndrome (AS) is a rare autosomal recessive ciliopathic condition affecting 1:10,00,000 children. It’s a single gene disorder of ALMS1 on chromosome 2 with multisystem involvement with cone-rod retinal dystrophy causing juvenile blindness, obesity, insulin resistance, type 2 Diabetes mellitus, hypogonadism and sensorineural hearing loss. Till now only 800 patients with this disorder has been identified so far. In this report, we describe the case of a 9-year old male boy from south India. He had been initially referred for polyphagia, polyuria, polydipsia, generalized weakness from 1 weeks. On examination he was demonstrated features suggestive of AS, including blindness, obesity, type 2 diabetes, altered lipid profile, hypogonadism, acanthosis nigricans, seborrheic dermatitis, right ear discharge and episodes of respiratory tract infections. So, diagnosis of AS is critical as it can easily be overlooked because of the many features associated with metabolic syndrome starting at age 7, a relatively early age.     

Session - 2 December 19, 2007 Lipid disorders and management of obesity

Serum ferroxidase and albumin levels were determined in 98 patients of tubercuiosis, of whom 49 were freshly diagnosed, sputum positive (group-I) & 49 were completely treated patients (group-II). Forty nine age and sex matched healthy individuals were taken as controls. Mean±SD of serum ferroxidase and albumin levels in controls, group-I and group-II was found to be 864.35±106.35 IU/L & 3.91±0.234 g/dL, 1603.76±222.65 IU/L & 3.24±0.518 g/dL and 1001.78±201.63 IU/L & 3.82±0.43 g/dL, respectively. Serum ferroxidase in group I was significantly higher as compared to controls and group-II (p<0.01). The decreased levels of serum albumin in group I, as compared to control and group-II was statistically significant (p<0.01). Serum ferroxidase: albumin ratio (Ferroxidase in International Unit per gram of albumin) in group I (50.47±10.36 IU/g) was significantly higher than controls (22.22±3.3 IU/g), (p<0.001) while in group II it was significantly lower (26.72±7.18 IU/g, p<0.001) than group-I and close to control values. Serum ferroxidase: albumin ratio (IU/g) can therefore be incorporated as a surrogate marker to assist in diagnosis and prognosis of pulmonary tuberculosis.     

Antral and duodenal disaccharidases in patients of duodenal ulcer and non-ulcer dyspepsia

Duodenal ulcer is a common disease and is considered acid-peptic disease. Duodenal ulcer patients are known to have higher incidence of antral gastritis and duodentitis than general population. Thus one can expect some alteration in the enzyme products of mucosal cells of antrum and duodenum in this condition. The present study was planned in 30 patients of duodenal ulcer and 30 of non-ulcer dyspepsia. After overnight fast, upper gastrointestinal endoscopy was done using forward viewing fibreoptic endoscope. Two pairs of biopsies were taken from the antrum and two from the descending duodenum using standard biopsy forceps. One pair of biopsy from each site was taken in 10% formal saline for histopathological examination. One pair of biopsies from each site was collected in saline for the measurement of disaccharidases by Dahlquist method. Activities of lactase, sucrase and maltase were significantly higher in descending duodenum mucosa as compared to antral mucosa in both groups. Activities of these enzymes in antrum and duodenum of both groups did not differ significantly. No significant difference was found in disaccharidases in antrum and descending duodenum in patients with or without histological gastritis. This study suggests that the disaccharidases do not change in antrum and duodenum of ulcer patients as compared to the patients with non-ulcer dyspepsia.