Using Logistic Regression and the Mantel-Haenszel With Multiple Ability Estimates to Detect Differential Item Functioning

Logistic regression has recently been advanced as a viable procedure for detecting differential item functioning (DIF). One of the advantages of this procedure is the considerable flexibility it offers in the specification of the regression equation. This article describes incorporating two ability estimates into a single regression analysis, with the result that substantially fewer items exhibit DIF. A comparable analysis is conducted using the Mantel-Haenszel with similar results. It is argued that by simultaneously conditioning on two relevant ability estimates, more accurate matching of examinees in the reference and focal groups is obtained, and thus multidimensional item impact is not mistakenly identified as DIF.     

Effect of antioxidants and antibiotics on levels of seminal oxidative stress in leukocytospermic infertile men

Defective sperm function is the most common cause of infertility. A prospective study was carried out to correlate the concentration of nitrite (the stable metabolite of nitric oxide) in seminal plasma with leukocytospermia, and sperm membrane integrity. Total Fifty-seven normozoospermic subjects with and without leukocytospermia visiting the Infertility clinic at KH and MRC, Karad, were included in the present study. Semen samples were checked for sperm concentration, total sperm count, sperm motility, seminal leukocyte concentration and sperm membrane integrity as Hypoosmotic Swelling Test. Similarly the concentration of nitrite in seminal plasma was measured by Griess reaction and total antioxidant power measured as ferric reducing ability of plasma. The concentration of nitrite in seminal plasma was found to be raised with significantly increased leukocyte concentration in semen. Also significantly lowered levels of total antioxidant power along with defective sperm function was observed. Our results suggest that supplementary treatment of antioxidants with antibiotic for leukocytospermic infertile male patients may improve the sperm membrane integrity.     

Lipid peroxidation and the levels of antioxidant enzymes in coronary artery disease

Coronary Artery Disease is the major cause of mortality and morbidity worldwide. Traditional risk factors account for only half of the morbidity and mortality from coronary artery disease. There is substantial evidence that oxidative stress plays the major role in the atherosclerotic process. The present study was undertaken to evaluate the level of lipid peroxidation (by measuring malondialdehyde) and antioxidant enzymes (ceruloplasmin, glutathione, superoxide dismutase) in coronary artery disease. Serum malondialdehyde levels and serum ceruloplasmin levels were significantly raised in all the subgroups of study group as compared to control group (p<0.001). Whole blood glutathione levels and hemolysate superoxide dismutase activity was significantly decreased in all the subgroups of study group as compared to control group (p<0.001). Above results suggests that the patients of coronary artery disease show increased oxidative stress and decreased levels of antioxidant enzymes. So it is recommended that the management protocol for coronary artery disease patients should include antioxidant supplementation along with simultaneous lowering of lipid peroxidation.     

Sex hormone binding globulin in breast cancer

The present study was undertaken to determine the significance of sex hormone binding globulin, the major and specific binding protein for testosterone and estradiol, in breast cancer. Among breast cancer patients, lower serum levels of Sex hormone binding globulin and higher levels of testosterone were observed. Sex hormone binding globulin showed an inverse relationship with testosterone and total cholesterol, and a direct relation with HDL-cholesterol. By the western blot analyses, Sex hormone binding globulin was detected in all biological samples that we examined. In the breast tumor tissue sections, immuno-staining for Sex hormone binding globulin was confined in cell cytoplasm and 29% cases were positive, which showed no association with the investigated prognostic markers of breast cancer such as ER and HER-2/neu over-expression. In this study, decreased circulating levels of Sex hormone binding globulin in breast cancer patients possibly indicate higher bioavailable estrogens.     

Acoustic communication in birds

The article highlights the biological significance of songs and calls in birds. The structural diversity of songs and its relevance for social behaviour are described. Acoustic communication plays an important role in the life of birds and has proven useful in establishing phylogenetic and evolutionary relationships among species.     

Michigan Citizens' Knowledge and Perceptions About Groundwater

Abstract

Knowledge and perceptions of Michigan residents about groundwater were assessed so that a comprehensive educational program could be developed and baseline information established to document the program's impact over time. Data were collected from 663 residents in urban, rural, and farm households. Results indicated that knowledge about groundwater was moderate and that a statewide educational campaign on facts about groundwater was necessary. People perceived that land use practices affected groundwater quality at the national, state, and county levels but not at their household level. Significant differences were found among urban, rural, and farm residents and between farmers and nonfarmers in their perceptions of the effects of land use on groundwater quality.     

Evaluating E-resource Collections in a Business School Library: A Comparative Study of Aggregator Packages at Indian Institute of Management Ahmedabad Library

The need to continuously evaluate resource usage, whether in print or online, has been a challenge for libraries for a long time. The shift in resources to digital formats has made gauging the utility of resources more convenient as well as enabling cross database comparisons on various parameters. In this context, the article explores the aggregator databases subscribed by Indian Institute of Management Ahmedabad library. The study compares EBSCO's Business Source Complete, EBSCO's Academic Search Premier, Proquest's ABI INFORM Complete, JSTOR, and Project Muse packages in terms of the features available, usage, and the most used journals in these packages.     

Networked Learning and Learning Analytics: A Study on the Employment of Facebook in a Virtual Training Program

The growing popularity of Social Networking Sites (SNS) that are embedded with networked infrastructures serves as an ideal platform for developing a networked learning environment connecting geographically dispersed learners. Unlike the traditional learning systems which provide only limited sources of data, the learners engaged in virtual networked social environments tend to produce huge volumes of digital footprints that cannot be analyzed using conventional analytical techniques. Two new branches of analytical sciences – Educational Data Mining (EDM) and Learning Analytics (LA) – are being employed for processing digital data derived from online educational platforms in order to obtain meaningful inferences and data-driven insights.

Hence, the present experimental study involving a small group of geographically dispersed learners intend to examine the engagement level and interaction patterns that occur within a feminist networked learning environment created in Facebook using popular EDM and learning analytical techniques such as K-means Clustering, Social network analysis and correlation mining. Upon analysis, it was found that the peer network influence played a vital role in activating passive learners, eventually leading to the development of a closely bound networked learning community over time.