On electrophysiological activity of the normal heart

The heart is divided into eleven components, each being modeled by a dipole of known and fixed location and direction; these dipoles are shown to result from the propagation of the transmembrane potentials over the surface of the myocardial cells. The components of the left ventricular wall are composed of “Durrer layers”, and these in combination with the “contiguity effect” result in a positive ventricular gradient and T-wave. Electrocardiograms generated by the eleven dipoles yield high-fidelity 12-lead ECG's.     

Risk of mother-reported child abuse in the first 3 years of life

OBJECTIVE: The purpose of this research was to investigate, within an at-risk population, parent and child characteristics associated with a mother's self-reports of severe physical assault and assault on the self-esteem of the child in the first 3 years of life. DESIGN: The study population consisted of a community-based sample of mothers of newborns identified as at-risk for child maltreatment (n=595). Families were assessed annually from the child's birth through age 3 using instruments with established psychometric properties. Independent variables investigated included: family socio-demographics, parity, mother's social support, maternal depression, maternal problem drug or alcohol use, partner violence, child's age, child's sex, low birth weight/small for gestational age (SGA), and mother's perception of child's demand level. Associations with maltreatment were examined using multivariable methods for longitudinal data. RESULTS: Child severe physical assault was significantly associated with parent characteristics (maternal depression and partner violence); and child characteristics (SGA). Assault to the child's self-esteem was significantly associated with maternal depression, maternal illicit drug use, partner violence and mother's perception of child's demand level. Controlling for family sociodemographic characteristics did not change the associations. Likewise, while mother's perception of child demand level had an independent association with self-esteem assault, the associations described above persisted while demand level was held constant. In this high-risk sample, abuse was not associated with mother's age, education, race, parity, or household income level. CONCLUSIONS: While characteristics such as SGA can serve as markers for increased abuse risk, they are not amenable to intervention after the child is born. However, certain other risk factors, such as maternal depression and domestic violence are malleable and should be targeted for intervention with the goal of preventing child maltreatment.     

Reference

INSIDE U.S. BUSINESS: A CONCISE ENCYCLOPEDIA OF LEADING INDUSTRIES by Philip Mattera (Homewood, IL: Dow Jones-Irwin, 1987—price not given)

DICTIONARY OF COMPUTERS, INFORMATION PROCESSING & TELECOMMUNICATIONS by Jerry Rosenberg (New York: John Wiley, 1987—$18.95, paper, with a hardback available as well)     

Book Reviews

Current legal issues in publishing A. Bruce Strauch (Editor), Hayworth Press Inc. July 1996, 144pp, $29.95 (outside USA/Canada/Mexico $36.00), ISBN: 1-56024-804-1 Publishing and Book Development in Sub-Saharan Africa: an annotated bibliography by Hans M. Zell & Cécile Lomer, London Hans Zell Publishers 1996, 409pp £60, ISBN 1-873836-46-5 The Scholar's Courtesy by Blaise Cronin. London: Taylor Graham, 1995, 124pp, £25 Society of Freelance Editors and Proofreaders, Directory of Members' Services 1997, Published by SFEP, Mermaid House, 1 Mermaid Court, London SE1 1HR, 198pp, £10, including p+p, ISSN 0960-5533     

Psychological factors capable of preventing the inhibition of antibody responses in separated infant monkeys

The capacity of infant squirrel monkeys to mount an antibody response to viral challenge was evaluated after removal from their mothers in several social and physical environments. Control and separated infants were injected with a benign virus, the bacteriophage X174, and levels of neutralizing antibody were assessed for 3 weeks. Infants separated alone in an unfamiliar environment showed a significant reduction in antibody levels as compared to control infants. Allowing infants to remain in the home environment, either alone or with peers, prevented this inhibition of antibody responses from occurring. Similarly, providing familiar peers in the novel environment facilitated the normal expression of antibody responses. These results indicate that the trauma of maternal separation is significantly reduced when infants are familiar with the separation environment or familiar social companions are available. The reduced antibody response was associated with the highest level of adrenal activation induced by the unfamiliar separation condition, but antibody titers and plasma cortisol levels could not be specifically correlated in individual infants.     

作为技术研究者的马克思

本文主旨在于讨论马克思的社会变革理论中技术和科学的地位与作用.文中强调了技术与经济间的相互作用和反馈关系,同时驳斥了将马克思当作技术决定论者的粗浅观点.马克思把技术看做人类和外部物质世界之间的媒介.通过对科学与技术的区分,指出机器生产的出现和科学在生产中的运用对于资本主义生产方式的重大意义.马克思还分析了资本品部门的特殊作用和资本主义趋向大规模生产的必然性,以及在资本主义条件下技术创新的各种形式.     

Making Sense of Uncertainty in the Science Classroom

Science & Education - Uncertainty is ubiquitous in science, but scientific knowledge is often represented to the public and in educational contexts as certain and immutable. This contrast can...     

Cable and Educational Media

Mary Louise Hollowell, ed, The Cable/Broadband Communications Book, 1977-1978 (Washington: Communications Press [1346 Connecticut Ave. N.W., 20036], 1977—$16.25 including postage, paper)

1976 NCTA Cable Services Directory (National Cable Television Association, 918 Sixteenth St. NW, Washington D.C. 20006—$4.00, paper)

Regulatinzfable Television Subscriber Rates: A Guide for Local Officials (Cable Television Information Center, Yrban Institute, 2100 M St. NW, Washington, D.C. 20037—$17.50 including postage, paper)

Alan Hancock Planning for Educational Mass Media (London and New York: Longman, 1977—$20.00)

Kenyon C. Rosenberg and John S. Doskey Media Equipment: A Guide and Dictionary (Littleton, Colo.: Libraries Unlimited, 1976—$11.50)     

Leisure Time Physical Activity and Job Performance

In this study, the dual-task paradigm was used to determine peak attentional demand during the free-throw process. Thirty participants completed 40 free-throw trials. The free throw was the primary task, but participants also verbally responded to a tone administered at one of four probe positions (PP). Repeated measures analysis of variance showed no significant difference in free-throw performance across PPs, indicating participants were able to keep the free throw as the primary task. Repeated measures analysis of response time (RT) showed significant differences, with RT at PP1 (preshot routine) and PP2 (first upward motion of the ball) significantly higher than baseline RT. These results suggest that PP1 requires the greatest attentional demand, followed by PP2.