Spatial variation in soil inorganic nitrogen across an arid urban ecosystem

We explored variations in inorganic soil nitrogen (N) concentrations across metropolitan Phoenix, Arizona, and the surrounding desert using a probability-based synoptic survey. Data were examined using spatial statistics on the entire region, as well as for the desert and urban sites separately. Concentrations of both NO₃-N and NH₄-N were markedly higher and more heterogeneous amongst urban compared to desert soils. Regional variation in soil NO₃-N concentration was best explained by latitude, land use history, population density, along with percent cover of impervious surfaces and lawn, whereas soil NH₄-N concentrations were related to only latitude and population density. Within the urban area, patterns in both soil NO₃-N and NH₄-N were best predicted by elevation, population density and type of irrigation in the surrounding neighborhood. Spatial autocorrelation of soil NO₃-N concentrations explained 49% of variation among desert sites but was absent between urban sites. We suggest that inorganic soil N concentrations are controlled by a number of ‘local’ or ‘neighborhood’ human-related drivers in the city, rather than factors related to an urban-rural gradient.     

A semi-parametric approach to robust parameter design

Parameter design or robust parameter design (RPD) is an engineering methodology intended as a cost-effective approach for improving the quality of products and processes. The goal of parameter design is to choose the levels of the control variables that optimize a defined quality characteristic. An essential component of RPD involves the assumption of well estimated models for the process mean and variance. Traditionally, the modeling of the mean and variance has been done parametrically. It is often the case, particularly when modeling the variance, that nonparametric techniques are more appropriate due to the nature of the curvature in the underlying function. Most response surface experiments involve sparse data. In sparse data situations with unusual curvature in the underlying function, nonparametric techniques often result in estimates with problematic variation whereas their parametric counterparts may result in estimates with problematic bias. We propose the use of semi-parametric modeling within the robust design setting, combining parametric and nonparametric functions to improve the quality of both mean and variance model estimation. The proposed method will be illustrated with an example and simulations.     

Parent‐Adolescent Communication About Sex: Retrospective Reports by Latino College Students

Latina female (n= 97) and Latino male (n= 69) college students (M age = 21.4 years) completed self‐report surveys regarding family of origin experiences, including sexual communication with parents while growing up. Latino parents of this comparatively highly educated sample tended to use direct rather than indirect strategies for communicating about sexuality with their children. Young women reported higher levels of sexual communication with mothers while growing up than did young men, and respondents reported less communication with fathers than mothers. Among young women, sexual communication with mother was positively associated with non‐Mexican origin and negatively associated with having older brothers living at home. In contrast, maternal education was positively associated with mother‐son communication about sex. Paternal education and the absence of older brothers positively predicted communication with both sons and daughters. The analyses provide novel information regarding sexual communication in Latino families and suggest directions for future research.     

Statistics for weighing benefits and harms in a proposed genetic substudy of a randomized cancer prevention trial

Summary.  When evaluating potential interventions for cancer prevention, it is necessary to compare benefits and harms. With new study designs, new statistical approaches may be needed to facilitate this comparison. A case in point arose in a proposed genetic substudy of a randomized trial of tamoxifen versus placebo in asymptomatic women who were at high risk for breast cancer. Although the randomized trial showed that tamoxifen substantially reduced the risk of breast cancer, the harms from tamoxifen were serious and some were life threaten-ing. In hopes of finding a subset of women with inherited risk genes who derive greater bene-fits from tamoxifen, we proposed a nested case–control study to test some trial subjects for various genes and new statistical methods to extrapolate benefits and harms to the general population. An important design question is whether or not the study should target common low penetrance genes. Our calculations show that useful results are only likely with rare high penetrance genes.     

More than Myth: The Developmental Significance of Romantic Relationships During Adolescence

Adolescents' romantic relationships have attracted popular interest, but, until recently, little scientific curiosity. Research has been impeded by erroneous assumptions that adolescent relationships are trivial and transitory, that they provide little information beyond measures of the influence of parent‐child and peer relationships, and that their impact is primarily associated with problems of behavior and adjustment. This article proposes that distinguishing five features of romantic relationships (involvement, partner selection, relationship content, quality, and cognitive and emotional processes) is essential to describing adolescents' relationships and their developmental significance. These distinctions also help to clarify the role of context, age‐related variations, and individual differences in the impact of romantic experiences. Research is needed to illuminate questions of how and under what conditions romantic relationships affect individual development and how romantic and other close relationships jointly influence developmental trajectories during adolescence.     

The Effects of E-journal Management Tools and Services on Serials Cataloging

E-journal management tools and services such as MARC record services, A-to-Z lists, and link resolvers are changing e-journal cataloging. This column explores these changes in the academic environment through interviews with ten librarians representing eight universities. Three areas of change in serials cataloging are explored: (1) changes to the MARC record, including how libraries are adding/creating MARC records for their catalogs, the number and type of MARC records being created and linking within MARC bibliographic and holdings records; (2) the manner in which serials catalogers are being informed of changes; and (3) the evolving role of the serials cataloger. Future trends and advice for evolving workflow practices conclude the discussion.     

Glass ceilings or sticky floors? A model of high-income law graduates

Minorities and females are underrepresented in the top-income quintile of law school graduates. Employing a binary logistic regression model, I examine whether this is due to a“glass ceiling” (an invisible barrier erected by third parties) or a“sticky floor” (self-imposed limitations regarding employment). My major finding is that being female, a minority, or disabled did not significantly reduce one's probability of making the top-income quintile once hours of work, experience, and other factors are taken into account. My findings directly contradict the large body of glass-ceiling literature and support the sticky-floor model. I thank the Law School Admission Council for funding this research. Helpful comments and suggestions were received from Robert Nelson of Northwestern University and the American Bar Foundation, Steven Conroy of the University of West Florida, and R. Kim Craft and Douglas Bonzo of Southern Utah University. The views expressed here are solely those of the author and do not necessarily reflect those of the institutions or persons listed above.     

A sea change on the island continent: frameworks for risk assessment,prevention and intervention in child health in Australia

This article overviews prevention and early intervention approaches focusing specifically on their relevance to the health of children and young people in Australia. Australian public health has a sound track record although concealed within the aggregate profile are a number of sub-populations with poorer health indicators. Recognition of this has increased efforts to improve the health of children and young people especially in exploring the impact of social environments within the communities where children are raised. This paper examines emerging research in this area drawing out key lessons and learning from Australian experience in the field of early intervention and prevention in community settings.     

Minimal treatments and problem gamblers: A preliminary investigation

In view of the increasing popularity of minimal intervention treatments for problem drinking, a self-help manual for people who wish to reduce or stop gambling was prepared. Twenty-nine (ACT residents) who responded to advertisements for help with problem gambling were allocated to either of two minimal treatments, Manual (only) and Manual & Interview. On average, clients from both groups reduced the frequency of their gambling sessions, frequency of overspending, and amount spent per week in the first three months and next three months after first contact, but expenditure per session increased from three to six months, after an initial improvement. There was no evidence that a single in-depth interview added to the effectiveness of the manual.This project was funded by a grant from the Australian National University Faculties Research Fund.