Antiracism defined as equitable sociocultural interactions in prekindergarten: Classroom racial composition makes a difference

This study used secondary data from the My Teaching Partner-Math/Science 2013–2016 randomized control trial to explore whether equitable sociocultural classroom interactions (see Curenton et al., 2019) were associated with the skills of 105 four- and five-year-olds (52% boys; drawn from 20 unique video recordings of preschool teachers/classrooms; 43% were Black, Latine, Asian, or other racially marginalized learners). Equitable interactions predicted children's skills with effect sizes ranging from small (0.01–0.44) to large (1.00). Moderation analyses revealed that when classrooms had more racially marginalized learners, teachers’ use of equitable disciplinary and personalized learning practices were associated with higher executive functioning gains across prekindergarten. Findings illustrate how classroom composition can be a key indicator between equitable classroom interactions and young children's early skills.     

Bond graphs for thermal energy transport and entropy flow

The transport of thermal energy in thermodynamics is described as the product of entropy flow and of the absolute temperature, in analogy to the volume flow and pressure in oil hydraulics and to electric charge flow (= current) and voltage in electronics. Bond graphs are shown to be especially suitable to describe the splitting of applied thermal energy into internal energy and external mechanical work. Transformers and the 0- and 1-junctions of Paynter can illustrate various entropy flow processes, including Carnot engines and heat exchangers. Entropy flow in heat conduction is distinguished from entropy convection, or transport by moving mass, where the entropy/temperature characteristic or equation of state is important. Irreversibilities are represented by impedance transformers reducing temperature and increasing entropy flow but conserving power.     

Feasibility of determination of fertile period in Indian women based on urinary hormone estimations

Baseline data available on the excretory profiles of estrone giucuronide (E₁G), pregnanediol glucuronide (PdG) and luteinising hormone (LH) on human menstrual cycles (n=104) was retrospectively analysed for identifying the limits of fertile period (FP) to be used as natural method of family planning. The limits of fertile period are suggested based on centile distribution of E₁G and PdG levels during defined phase of menstrual cycle. Two approaches, which do not involve any mathematical calculation are suggested. In approach A, fertile period is said to have started when E₁G value of 35 ng/ml is reached and is said to have ended when the PdG value of 2 μg/ml on two consecutive days is obtained. The criteria were applied to 30 test cycles in whom authentic fertile period was identified based on excretory profiles of E₁G, PdG and LH throughout the menstrual cycles. When approach A was followed the authentic fertile period was covered in 27 cycles giving an accuracy of 90% with a mean fertile period length of 9.11+1.9 days. In approach B, the cut off limit of E₁G value was increased to 55 ng/ml in order to reduce the days of abstinence. Though the length of the fertile period was reduced to 7.2+1.5 days the accuracy of the approach was 66.6%. Thus the approach A which has accuracy of 90% may appeal to determined couples who wish to practice family planning by periodic abstinence or restrict the use of barrier methods.     

The impact of education policy on economic development: Quantity,quality and earnings of labor

Education policy is viewed as affecting the content, and hence production functions, of different types of training and skill-formation. The relationship between skill type and level of education is considered. Optimal investment requires equating rates of return on the extensive and intensive margins, making endogenous the trade-offs between quantity and quality for each skill type. Selected education production functions are discussed with respect to implications for the distribution and levels of different skills and for skill-related earnings differentials. Equality of educational opportunity increases skill levels, upgrades the occupational structure and reduces relative earnings differentials.