Thyroidal regulation of substrate kinetics properties of cytochrome oxidase in rat liver mitochondria

Effects of thyroidectomy (T_x) and subsequent treatment with 3,5,3’-triiodothyronine (T₃), and combined treatment (T_R) with T₃ + thyroxine (T₄) on substrate kinetics properties of cytochrome oxidase of rat liver mitochondria were examined. T_x resulted in lowering of cytochromes content with decrease in the enzyme activity, and K_m and V_max. T₃ and T_R regimens restored the cytochromes contents and the V_max values to normal. In control, T₃ and T_R groups the enzyme activity resolved in two kinetic components; in T_x group three kinetic components were evident. The K_m values for all components decreased significantly in the experimental groups with concomitant increase in catalytic efficiency, K_cat/K_m. Significant alterations in the contents of total phospholipid and of cholesterol were noted while the changes in the phospholipids composition were only of restricted nature. Regression analysis revealed that total phospholipid, cholesterol and phosphatidylcholine, phosphatidylethanolamine play significant role in fine tuning the enzyme activity.     

Effect of L-carnitine Supplementation on Nutritional Status and Physical Performance Under Calorie Restriction

L-carnitine is popular as a potential ergogenic aid because of its role in the conversion of fat into energy. The present study was undertaken to investigate the effect of short term supplementation of L-carnitine on metabolic markers and physical efficiency tests under short term calorie restriction. Male albino rats were divided into four groups (n = 12 in each)—control, calorie restricted (CR for 5 days, 25 % of basal food intake), L-carnitine supplemented (CAR, given orally for 5 days at a dose of 100 mg/kg), CR with L-carnitine supplementation (CR + CAR). Food intake and body weight of the rats were measured along with biochemical variables like blood glucose, tissue glycogen, plasma and muscle protein and enzymatic activities of CPT-1 (carnitine palmitoyl transferase-1) and AMP kinase. Results demonstrated that L-carnitine caused marked increase in muscle glycogen, plasma protein, CPT-1 activity and swim time of rats (P < 0.05) on short term supplementation. In addition to the substantive effects caused by CR alone, L-carnitine under CR significantly affected muscle glycogen, plasma protein, CPT-1 activity and AMP kinase (P < 0.05). Short term CR along with L-carnitine also resulted in increased swim time of rats than control, CR and L-carnitine treated rats (P < 0.05). The present study was an attempt towards developing an approach for better adherence to dietary restriction regimen, with the use of L-carnitine.     

Classroom interaction in regular and special education middle primary classrooms in the United Arab Emirates

Samir Dukmak is an assistant professor in the Department of Special Education in the Faculty of Education at the United Arab Emirates University. The research reported in this article investigated the frequency, types of and reasons for student-initiated interactions in both regular and special education classrooms in the United Arab Emirates (UAE). These interactions were studied in relation to various variables, including levels of students' academic achievement, their gender, special educational needs and disability. Teacher-initiated interactions were also examined in the study. Eighteen boys and girls from two regular and two special education classrooms were observed. Various types of interaction were identified among students and the results reveal that boys in all groups initiated more interactions than girls, and that high-achieving boys and girls initiated more interactions than their low-achieving counterparts. The findings also reveal that teachers interacted differently with boys versus girls. The reasons prompting students to initiate classroom interaction are highlighted in this research.     

The role of pre-school education on learning achievement at primary level in Bangladesh

This paper examines the impact of pre-school education on learning achievement at primary level in Bangladesh. Evidence from learning achievement test and household and school-related data were obtained from 7093 pupils attending 440 primary schools in Bangladesh. Findings suggest that a small proportion (15.3%) of primary school pupils attended pre-school. Pupils from educated parents and well-off families were more likely to attend. In principle, however, attendance at pre-school did not predict later learning achievement at primary level, but a range of socio-demographic, school-related and additional educational factors did have an impact. It is concluded that further research is warranted to examine the quality of pre-school provision offered in Bangladesh and the qualifications of professionals working with young children in these centres.     

An Investigation of Counselor Educators' Attitudes Toward Evidence‐Based Practices

Evidence‐based practices (EBPs) receive little attention in counselor education curricula despite the ethical obligation for counselor educators to teach EBPs to counseling students. This study investigates counselor educators’ attitudes toward EBPs along with perceived barriers to the inclusion of EBPs in counselor education curricula.     

Dust in space

Dust grains in space, which absorb and redden starlight, were once considered to be a nuisance for astronomers, but the study of dust has become important in modern astrophysics. A few interesting characteristics of these dust grains are discussed here.