Calculating the density and distribution function for the singly and doubly noncentral F

Simple, closed form saddlepoint approximations for the distribution and density of the singly and doubly noncentral F distributions are presented. Their overwhelming accuracy is demonstrated numerically using a variety of parameter values. The approximations are shown to be uniform in the right tail and the associated limitating relative error is derived. Difficulties associated with some algorithms used for exact computation of the singly noncentral F are noted.     

Beliefs and social norms about codeine and promethazine hydrochloride cough syrup (CPHCS) onset and perceived addiction among urban Houstonian adolescents: an addiction trend in the city of lean

In the current study, we used a qualitative approach to investigate relevant beliefs and norms associated with codeine and promethazine hydrochloride cough syrup (CPHCS) consumption, initiation, and perceived addiction among 48 alternative school students who identified themselves as current CPHCS users. In general, both boys and girls believed that CPHCS addiction started during an individual's initial consumption. A majority of both groups reported that their second CPHCS event was initiated during the same or next day after their first event. Our findings suggest that friends and an innovative form of hip-hop music called "screw" are strong reinforcers of CPHCS use.     

Germline genomes--a biological fountain of youth?

The fusion of male- and female-derived gametes initiates the phenomenal process of producing a highly complex mammalian organism. Successful reproduction is so important that mammals invoke a battery of protective mechanisms for the germ cell lineages that function to maximize genetic integrity while still allowing genetic diversity and adaptation. Protective mechanisms likely include, but are not limited to, robust DNA repair to safeguard genetic integrity and apoptosis to remove cells with intolerable levels of DNA damage. Analyses of spontaneous mutant frequencies are generally consistent with germline DNA being stringently maintained relative to somatic tissues. Despite the rigorous protection afforded germ cells, genetic integrity is observed to decline with increased maternal and paternal age. It is not yet clear whether cells in the germ line truly age or whether other processes decline or become dysfunctional with age. For example, in a younger animal, the differentiation and/or utilization of germ cells with lower genetic integrity might be disallowed, whereas in an older animal, such cells might slip past these quality-control mechanisms.     

Relationships Between Parenting Styles and the Academic Performance of Adolescents

Relationships between parenting styles, academic performance, and the mediating effects of motivation, goal orientation, and self-efficacy were examined. One hundred forty-eight high school students participated, including 58 males and 90 females. The Parenting Style/Parental Involvement Questionnaire was used to measure students' perceptions of their parents' parenting styles. The Intrinsic-Extrinsic Orientation Scale measured students' motivation. The Patterns of Adapted Learning Survey measured participants' goal orientation and academic self-efficacy. Adolescents who reported their parents as having a more authoritative parenting style were found to demonstrate more intrinsic motivation in their academic pursuits. Future implications for intervention and research are discussed.     

The association between job skill discretion, decision authority and burnout

This paper reports on the relationship between dimensions of control (skill discretion and decision authority) and burnout (emotional exhaustion, depersonalization, and reduced personal accomplishment) among 164 human service workers. It examines the differential influence of job demands, control (skill discretion and decision authority) and social support (supervisor, co-workers, others) on each burnout dimension. Then it examines the moderating effects of higher skill discretion, higher decision authority, and higher social support on burnout. Low skill discretion was found to be associated with high emotional exhaustion and depersonalization and low personal accomplishment. The effects of decision authority were not statistically significant. High job demands were associated with high emotional exhaustion only. Social support (supervisor, co-worker, and others) was not associated with burnout when demographic variables and job characteristics were controlled for. Neither dimension of control moderated the impact of high job demands on burnout. Social support did not moderate the impact of high demands, low skill discretion, or low decision authority on any burnout dimension. The full model explained 44% of the variance in emotional exhaustion, 25% in depersonalization, and 42% in personal accomplishment. Despite its limitations, the study suggests that the Job Demand-Control model may provide a useful theoretical foundation for the study of burnout, but that the control dimensions need to be evaluated independently since they appear to be differentially related to the burnout dimensions.     

Seeing poor children: Three artists' views

This essay explores representations of poverty in art. In so doing, the visual arts are offered as a supplement to traditional textual studies of poverty. The depiction of poor children in particular is rare before the modern period, and reasons for this are explored. Significant literary and artistic treatments of children in poverty, which begin to appear in the 19th century, are considered in the context of philosophical, political, and economic developments of the time. The New York painter of street children J. G. Brown represents Victorian era painters of poor children in that he distanced himself and his images from reality. More involved in the lives of the poor was the early 20th-century German printmaker Ka¨the Kollwitz, who steered away from the impetus to abstraction of that period in favor of an emotionally charged, politicized, activist approach which focused on the topic of children in misery. Finally, the use of photographs to document poor children is briefly summarized to set the stage for a consideration of the work of Wendy Ewald. This artist's novel approach of giving poor children the means to depict themselves and their own world breaks down the barrier between artist and subject and unifies them in a common purpose.     

Innovations to Make Markets More Inclusive for the Poor

Market failures, government failures and some of the characteristics of both the poor and business actors as well as their environment can act as barriers preventing the poor from participating more actively in markets, both as consumers and as producers. Private actors ‐ including for‐profit and not‐for‐profit entities, often in partnership with the public sector ‐ have been able to mitigate some of these constraints through innovations that have helped to make markets more inclusive for the poor, enabling them not just to gain access, but also to participate in ways that enhance their economic empowerment and human development. This article identifies the strategies and innovations used and devises a possible typology for them.     

Criteria for Welfare: Needs or Earnings?

The Report of the Poverty Commission followed Australian practice and recommended that payments to pensioners and beneficiaries be based on their needs. Two other recent reports, the Woodhouse Report on compensation for accidents and sickness, and the Hancock Report on National Superannuation, suggest an entirely different set of criteria—earnings and earnings-related contributions. It is argued that the latter proposals would discriminate inequitably between different groups of beneficiaries and that Australia should continue on a needs basis moving forward to a guaranteed minimum income scheme.