A test for correlation based on Kendall's tau

A consistent estimator for the variance of Kendall's tau is proposed which allows for testing the hypothesis of no correlation in a bivariate distribution. The null distribution of the test statistic is tabulated under independence, and the properties of the test are discussed.     

Single motherhood by choice: A parenting alternative

The experience of single motherhood by choice has become more prevalent in the last twenty years and yet the literature reveals a dirth of information about this parenting style. This article delineates the experience of choosing single motherhood utilizing artificial insemination by donor. Several issues are examined: (a) emotional factors and personality characteristics of the mother, (b) physiological factors related to artificial insemination, (c) ethical and legal considerations of artificial insemination and single motherhood, and (d) various economic concerns related to single motherhood.Ann Potter completed her Ph.D. in counseling psychology at the University of Nebraska-Lincoln and is Assistant Professor of Nursing at Clarkson College of Nursing, 333 South 44th Street, Omaha, NE 68131. Her current research interests are children and families of alcoholics, nontraditional families including single motherhood by choice, and incest survivors.Patricia Knaub is Associate Dean of the College of Home Economics and Associate Professor of Human Development and the Family at the University of Nebraska-Lincoln. Her address is 105 Home Economics, University of Nebraska-Lincoln, Lincoln, NE 68583-0800. She completed her Ph.D. at Nebraska and current research interests include stress and coping strategies of farm families, successful remarriages, and issues related to conception, including transference of myths and artificial insemination.     

Population momentum: A wider definition

Summary Keyfitz has derived an elegant formula for estimating the ultimate size of an initially stable, growing population that abruptly reduces its fertility to replacement level. Reduction of fertility is achieved by the rather unrealistic device of dividing the original age schedule nffertility rates by the net reproduction rate. Only the inertia of the age distribution is thus accounted for, but not that of the fertility schedule. The key idea of an abrupt imposition of a fixed regimen capable in the long run of generating zero population growth may be retained, but the regimen made more realistic. By elaborating the population setting, such disparate ZPG regimens as reduction of marital fertility by contraception, delayed and/or less universal marriage, raised mortality risks, or permanent net out-migration may be formulated. Convergence of the populaton to stationarity becomes a two-phase process: a primary adjustment period of changing fertility rates followed by a period of age adjustment. The present paper treats what happens when a fixed ZPG sterilization regimen, defined by a minimum age of sterilization γ and constant continuous risk φ of sterilization among unsterilized wives aged γ to β, is imposed abruptly (or else progressively over an interval T) upon an initially stable, growing population. Additional sources of residual growth are: (1) the nine-month lag in sterilization effect owing to pregnancy: (2) the more youthful pattern of child-bearing under sterilization: (3) the extra adjustment period (of length β-γ-0.75) of changing fertility rates; and (4) any delays in exposing elements of the population to the sterilization regimen. Two questions are pursued. First, how important are the additional sources of residual growth? Secondly, how do their relative sizes vary as a function of the characteristics of the initial population?     

Getting home on time: predicting timely permanence for young children

The timelines of the Adoption and Safe Families Act (ASFA) (P.L. 105-89) require increased attention to the timing of permanent placement, regardless of the type of placement outcome. This study examines the multivariate predictors of timely permanence for children served by Colorado's Expedited Permanency Planning (EPP) project. EPP has used an intensive concurrent planning model aimed at reaching permanency within 12 months of initial placement for children aged 6 and younger. The EPP requirement that children be living in the permanent home by 12 months postplacement is more stringent than the technical ASFA requirements. This article uses qualitative interviews with child welfare and court personnel to identify critical barriers to and supports for effective permanency planning.     

Age-related changes in maximal power and maximal heart rate recorded during a ramped test in 114 cyclists age 15-73 years

This study assessed age-related changes in power and heart rate in 114 competitive male cyclists age 15-73 years. Participants completed a maximal Kingcycle ergometer test with maximal ramped minute power (RMPmax, W) recorded as the highest average power during any 60 s and maximal heart rate (HRmax, beats/min) as the highest value during the test. From age 15 to 29 (n = 38) RMPmax increased by 7.2 W/year (r = .53, SE 49 W, p < .05). From age 30 to 73 (n = 78) RMPmax declined by 2.4 W/year (r = - .49, SE 49 W, p < .05). Heart rate decreased across the full age range by 0.66 beats . min( -1 ) . year( -1 ) (r = -.75, SE 9 beats/min, p < .05). Age accounted for only 25% of the variance in RMPmax but 56% in HRmax. RMPmax was shown to peak at age 30, then decline with age, whereas HRmax declined across the full age range.     

Epistemological inclusiveness in researching the African American community

Abstract

African American communities have experienced negative effects from a history of medical abuse, lack of proper research procedures, and misinterpretations of study findings because of racism. These past injustices have led to a mistrust of research and researchers. This paper focuses on how some methodological challenges, in a study funded by a National Institutes of Health grant on two low-income African American communities in Kentucky, were mediated through the collaboration of a multi-racial/ethnic team of researchers engaged in cross-disciplinary research. The information for this paper is based on the reflections of key members of the research team. The reflections show that having researchers with different epistemologies resulted in a culturally aware and sensitive study in which emic and etic research approaches were adopted. The inclusion of race-based epistemologies and close community ties were found to be particularly useful in building trust and getting the support of the two communities. However, these outcomes were only possible because research team members provided each other latitude for intellectual freedom and leadership.     

‘I accept my son for who he is – he has incredible character and personality’: fathers’ positive experiences of parenting children with autism

Literature in the field of autism is largely deficit driven, with a focus on the inabilities of individuals and the negative experiences of families, often characterised by reductive assumptions and tragedy model interpretations. In addition, family-orientated research has generally overlooked the views and contribution of fathers of disabled children, with positive paternal narratives especially scarce. This study explored 198 father perspectives on perceived benefits of parenting their children with autism, gained in response to an open-ended question in an online survey. Key themes relate to appreciating children’s individual qualities, valuing the strong emotional bond, fathers’ own nurturing role and their associated personal development. Findings will be discussed in relation to models of childhood disability and fatherhood.