Living arrangements and children's development in low-income White, Black, and Latino families

This article uses longitudinal data from approximately 2,000 low-income families participating in the national evaluation of the Comprehensive Child Development Program to examine the associations between preschool children's living arrangements and their cognitive achievement and emotional adjustment. The analysis distinguishes families in which children live only with their mothers from children who live in biological father, blended, and multigenerational households. Linkages are examined separately for White, Black, and Latino children. Fixed effects regression techniques reveal few significant associations between living arrangements and child development. These findings suggest that substantial diversity exists in the developmental contexts among children living in the same family structure. Policies seeking to change the living arrangements of low-income children may do little to improve child well-being.     

Quantification of the specific membrane capacitance of single cells using a microfluidic device and impedance spectroscopy measurement

The specific membrane capacitance (SMC) is an electrical parameter that correlates with both the electrical activity and morphology of the plasma membrane, which are physiological markers for cellular phenotype and health. We have developed a microfluidic device that enables impedance spectroscopy measurements of the SMC of single biological cells. Impedance spectra induced by single cells aspirated into the device are captured over a moderate frequency range (5 kHz–1 MHz). Maximum impedance sensitivity is achieved using a tapered microfluidic channel, which effectively routes electric fields across the cell membranes. The SMC is extracted by curve-fitting impedance spectra to an equivalent circuit model. From our measurement, acute myeloid leukemia (AML) cells are found to exhibit larger SMC values in hypertonic solutions as compared with those in isotonic solutions. In addition, AML cell phenotypes (AML2 and NB4) exhibiting varying metastatic potential yield distinct SMC values (AML2: 16.9 ± 1.9 mF/m² (n = 23); NB4: 22.5 ± 4.7 mF/m² (n = 23)). Three-dimensional finite element simulations of the microfluidic device confirm the feasibility of this approach.     

Characterising the impact performance of field hockey sticks

Published research on field hockey equipment is scarce. The aim of this research was to investigate methods for characterising the impact performance of field hockey sticks. Three sticks were used with fundamental frequencies in the range 74?C154?Hz. Striking an initially still ball with a stick was identified as the preferred method for characterising performance. Impacts were simulated at mean velocities of 19?m/s at toe and 16?m/s at the shaft. The mean apparent coefficient of restitution and standard deviation were ?0.32?±?0.05 at the toe and ?0.18?±?0.02 at the shaft. The foundation work presented here provides the foundations for developing a methodology for characterising the impact performance of field hockey sticks.     

Teacher effects on student attrition and performance in mass-market tertiary education

Tertiary education is now accessible even to those who appear unlikely ex ante to succeed in jobs requiring post-high school education. Institutions that have broadened access to their programs must rely on two things to protect the quality of the degrees they award: selection mechanisms operating during students’ tenure, and effective teaching. This paper explores the relative strength of these two forces in a broad-spectrum, first-year undergraduate course. Using detailed data from the University of South Australia on student background, tutors, performance, and enrollment across 15 weeks in a first-year core course, I explore the extent to which teachers impact upon the success of their students directly (through effective teaching) and indirectly (through facilitating the dropping out of more poorly-prepared students). Results indicate that teachers vary widely in their influence on attrition and performance, and that none is robustly effective in facilitating both the disproportionate out-selection of students with poor initial preparation, and the disproportionate achievement of this group. Performance at neither of these tasks is predictable based on teachers’ formal university affiliation.     

Library development and the joint commission on accreditation of hospitals standards.

The author traces the historical development of standards for library services prepared by the Joint Commission on Accreditation of Hospitals, emphasizing those elements of the present standards that auger well for the development of libraries in hospitals. Then examined are the role of librarians and new roles for libraries, stressing sound management practices that ensure continued development.     

Doing a science project: Gender differences during childhood

By adolescence, men's participation and achievement in science exceeds women's. This article reports a case study that examined the beginnings of this gender differentiation during a naturally occurring academic activity that was designed to support and guide young children's interest in doing science. Data were collected during 2 successive years of a science fair for children in Grades 1–6 of a progressive private school. A total of 268 projects were characterized in terms of achievement and area of science. Parents provided information about the way children selected and created projects. In both years and in all grade levels, boys tended to choose to work in the physical sciences, and girls in the biological and social sciences. Peer collaborations were exclusively same sex. Achievement and parental involvement were not gender related. Factors are discussed that might lead to an early divergence of boys' and girls' interests in science within a context that promotes its exploration. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 845–857, 1998.     

Factors associated with physical activity referral uptake and participation

The aim of this study was to examine participant and scheme characteristics in relation to access, uptake, and participation in a physical activity referral scheme (PARS) using a prospective population-based longitudinal design. Participants (n = 3762) were recruited over a 3-year period. Logistic regression analyses identified the factors associated with the outcomes of referral uptake, participation, and completion (> or = 80% attendance). Participant's age, sex, referral reason, referring health professional, and type of leisure provider were the independent variables. Based on binary logistic regression analysis (n = 2631), only primary referral reason was associated with the PARS coordinator making contact with the participants. In addition to the influence of referral reason, females were also more likely (odds ratio 1.250, 95% confidence interval 1.003-1.559, P = 0.047) to agree to be assigned to a leisure provider. Referral reason and referring health professional were associated with taking up a referral opportunity. Older participants (1.016, 1.010-1.023, P < 0.001) and males were more likely to complete the referral. In conclusion, the PARS format may be less appropriate for those more constrained by time (women, young adults) and those with certain referral reasons (overweight/obesity, mental health conditions). More appropriate targeting at the point of referral could improve participation rates by revealing or addressing barriers that might later result in dropout.