Sampling In Everyday Life in Nigeria

This article describes a means of introducing the elementary concepts of sampling with practical class based discussions to a group of first year students in a four year degree programme in Statistics and in other Science courses at the University of Ilorin, Nigeria. This class is equivalent to the Advanced level course and the students are usually of ages between 17 and 19 years.     

Creating a Developmental Scale to Account for Heterotypic Continuity in Development: A Simulation Study

Many psychological constructs show heterotypic continuity—their behavioral manifestations change with development but their meaning remains the same. However, research has paid little attention to how to account for heterotypic continuity. A promising approach to account for heterotypic continuity is creating a developmental scale using vertical scaling. A simulation was conducted to compare creating a developmental scale using vertical scaling to traditional approaches of longitudinal assessment. Traditional approaches that failed to account for heterotypic continuity resulted in less accurate growth estimates, at the person- and group level. Findings suggest that ignoring heterotypic continuity may result in faulty developmental inferences. Creating a developmental scale with vertical scaling is recommended to link different measures across time and account for heterotypic continuity.     

Book reviews

The Light That Shines: Chapel Hill, 1912–1916. Robert B. House. (Chapel Hill: University of North Carolina Press, 1964. Pp. 216. $5.00.)

Psychology of Adolescence for Teachers. Glenn Myers Blair and R. Stewart Jones. (New York: Macmillan, 1964. Pp. 118. $1.50, paper.)

Psychology of the Child in the Classroom. Don C. Charles. (New York: Macmillan, 1964. Pp. 86. $1.25, paper.)

Reading Instruction for Today's Children. Nila Banton Smith. (Engle‐wood Cliffs, New Jersey: Prentice‐Hall, 1963. Pp. 594. $7.50.)

Religion and the Schools, The Great Controversy. Paul Blanchard. (Boston: Beacon Press, 1963. Pp. 265. $4.95.)

School Business Administration in the Smaller Community. Fredrick W. Hill and James W. Colmey. (Minneapolis: T. S. Denison and Company, 1964. Pp. 324. $7.95.)

Sociology of Childhood. Oscar W. Ritchie and Marvin R. Koller. (New York: Appleton‐Century‐Crofts, 1964. Pp. 333. $5.00.)

The Teaching of Mathematics. Roy Dubisch. (New York: John Wiley and Sons, 1963. Pp. 124. $2.95, paper.)

Vignettes on the Theory and Practice of School Administration. Finis E. Engleman, Shirley Cooper, and William J. Ellena. (New York: The Macmillan Company, 1963. Pp. 237. $4.80.)     

An Educational Intervention Designed to Increase Women's Leadership Self-Efficacy

Women are sparsely represented in leadership in academic science, technology, engineering, mathematics, and medicine (STEMM). Cultural stereotypes about men, women, and leaders influence the attitudes, judgments, and decisions that others make about women and the choices women make for themselves. Multilevel interventions are needed to counteract the impact of these pervasive and easily activated stereotypes, which conspire in multiple ways to constrain women's entry, persistence, and advancement in academic STEMM. We describe an individual-level educational intervention. Using the transtheoretical model of behavioral change as a framework, we assessed the success of a semester course on increasing women's leadership self-efficacy for the first three cohorts of course participants (n = 30). Pre/post questionnaires showed gains in leadership self-efficacy, personal mastery, and self-esteem, and decreases in perceived constraints. Qualitative text analysis of weekly journals indicated increasing leadership self-efficacy as course participants applied course information and integrated strategies to mitigate the impact of societal stereotypes into their own leadership practices. Follow-up queries of the first two cohorts supported the enduring value of course participation. We conclude that providing strategies to recognize and mitigate the impact of gender stereotypes is effective in increasing leadership self-efficacy in women at early stages of academic STEMM careers.     

Counting cells with a low-cost integrated microfluidics-waveguide sensor

The capability to count cells from biofluids at low cost has important diagnostic implications in resource-poor settings. Many approaches have been developed to address this important need, and while most envision a low per-test cost, the detector instrument can be quite expensive. In this report, we present a novel device that enables low-cost and rapid counting of cells from a drop of blood. We demonstrate a shallow, buried, planar waveguide fabricated by ion exchange in glass that underlies a microfluidic structure for capturing cells. Laser light transmitted through the waveguide was attenuated by the number of metal nanoparticles tagged to the cells because of the interaction of the metal particles with the evanescent field of the waveguide. Calibration of the sensor using bead-tagged lymphocytes captured from human blood showed that the sensor could semi-quantitatively count as few as 100 cells/μL of blood. This technology enables the enumeration of specifically captured cells, allowing for a point-of-care, hand-held device for fast and affordable cell counting in screening, remote, or resource-poor settings.