Vegetation type alters water and nitrogen budgets in a controlled,replicated experiment on residential-sized rain gardens planted with prairie,shrub, and turfgrass

Vegetation type alters surface hydrology and nitrogen (N) cycling by partitioning evapotranspiration (ET) and drainage, but has not been fully utilized for this purpose in the design of urban rain gardens. Replicated treatments of three vegetation types (prairie, shrub, and turfgrass) commonly planted in rain gardens, as well as bare soil (control), were evaluated 1 year after establishment in 12, free-drainage bioretention cells designed to specifications for residential rain gardens in the Midwestern United States. Water and N budgets were calculated to assess differences in ET, drainage, soil moisture, and N transport following three stormwater applications in July, August, and October of 2006. Evaporative demand was also estimated as potential or reference ET during the study period using Hamon, Priestley-Taylor, and FAO Penman-Monteith models. Results show that after 1 year of establishment, vegetation type changed the water budgets of rain gardens thus altering their provisioning of ecosystem services via observed tradeoffs between daytime evaporative cooling (ET), stormwater storage, N-load reduction, soil and plant N retention, and groundwater recharge (drainage). Vegetation effects on hydrology and N transport were most significant when evaporative demand was high during the middle of the growing season. Observed changes in ET, drainage, soil moisture, and N transport support the incorporation of different vegetation types into conceptual and numerical models of rain gardens to assess ecological outcomes and tradeoffs at a variety of spatiotemporal scales.     

Investigating the effects of trauma-related research on well-being

Using an experimental design, we investigated the impact of participation in trauma-related research on well-being in a sample of 219 higher education students. We created five conditions that exposed participants to questions about life events. A sixth condition represented a control condition. Exposure conditions varied according to whether they contained yes/no questions about events that entailed stress, stigma, trauma, or sexual violation. We operationalized well-being by measuring positive and negative affect, state anxiety, and positive reactions to research. Across exposure conditions, participants reported low levels of negative affect and generally positive reactions immediately after participation. The most negative and least positive responses followed exposure conditions that contained questions about stressful events and sexual violation. We discuss implications of our findings for ethics review board practices.     

Investigating the Effects of Trauma-Related Research on Well-Being

Using an experimental design, we investigated the impact of participation in trauma-related research on well-being in a sample of 219 higher education students. We created five conditions that exposed participants to questions about life events. A sixth condition represented a control condition. Exposure conditions varied according to whether they contained yes/no questions about events that entailed stress, stigma, trauma, or sexual violation. We operationalized well-being by measuring positive and negative affect, state anxiety, and positive reactions to research. Across exposure conditions, participants reported low levels of negative affect and generally positive reactions immediately after participation. The most negative and least positive responses followed exposure conditions that contained questions about stressful events and sexual violation. We discuss implications of our findings for ethics review board practices.     

Low‐Income Students and College Attendance: An Exploration of Income Expectations*

Objectives. Some have hypothesized that unrealistic expectations regarding their futures may explain the weak link between expectations and realizations among low‐income (particularly minority) youth. Unfortunately, there is little evidence characterizing students' expectations around the time that they make college decisions that would allow one to study this hypothesis. Methods. In this exploratory article, I analyze data on income expectations from a small sample of low‐income minority high school seniors in Baltimore City, MD; and use data from Dominitz and Manski's sample of higher‐income white students in Madison, WI, and the NELS88 for comparisons. Results. I find little evidence that the income expectations of lower‐income minority students are so different from those of higher‐income students. Rather, the expected returns to postsecondary education appear similar between the two samples of high school seniors. Analysis of a nationally representative sample of high school seniors suggests that lower‐income students do not place less weight on expected economic returns to college when making their plans than do more advantaged students, although low‐income students are less able to translate their college plans into actual college attendance. Conclusions. These results suggest that differing income expectations do not explain the weaker relationship between expectations and educational attainment among low‐income students.     

Where do underage college students get alcohol?

Alcohol consumption and related problems are common among underage college students, yet qualitative, in-depth information on how/where these students obtain alcohol is limited. We conducted focus groups pertaining to access to alcohol and related issues with 19 underage college students. They reported that alcohol is easy to obtain from a variety of sources, with friends/acquaintances who are of legal age or those with a false ID being the most common. Parties were also common sources, but "shoulder tapping" (i.e., asking a stranger to purchase alcohol) was not common. Disagreement arose over whether underage fraternity/sorority members have greater access to alcohol than non-Greeks. Our results provide updated information on the various sources of alcohol and associated issues among underage college students.     

Adapting sample size calculations to repeated measurements in clinical trials

Many of the repeated-measures sample size calculation methods presented in the literature are not suitable when: •the different treatments are assumed to be equal on average at baseline time due to randomization, •and the experimenters are interested in a pre-specified difference to be detected after a specific time period. The method presented here has been developed for those cases where a multivariate normal distribution can reasonably be assumed. It is likelihood-based and has been designed to be flexible enough to handle repeated-measures models, including a non-linear change in time, and an arbitrary correlation structure.     

A Preliminary Investigation of the Reinforcement Function of Signal Detections in Simulated Baggage Screening: Further Support for the Vigilance Reinforcement Hypothesis

The vigilance reinforcement hypothesis (VRH) asserts that errors in signal detection tasks are partially explained by operant reinforcement and extinction processes. VRH predictions were tested with a computerized baggage screening task. Our experiment evaluated the effects of signal schedule (extinction vs. variable interval 6 min) and visual field complexity (dial vs. baggage x-ray) on search behavior rates. There was a main effect for signal schedule [F (1, 20) = 14.0, p = .001, p_rep = 0.99], but no effects for field complexity or interaction. The VRH suggests that performance errors in visual screening work may be reduced through operant conditioning of search behaviors by intensive management of artificially planted signals.     

Foster family care review by judicial-citizen panels: an evaluation

The findings of this study are mixed. In general, after one year of judicial-citizen review, there is no clear indication that this alternative to internal case review has led to more positive outcomes for children in foster care. This finding should be heartening to public child welfare agency personnel whose motivation for accountability has been called into question by proponents of external foster care review. At least when compared with a new citizen review system, the already existing internal review system measured up quite well. Although the study did not indicate a clear pattern of more positive outcomes for the study group, there is evidence of some favorable characteristics of CRPs that may show promise for the future. With additional training in developing behaviorally measurable and time-limited parental objectives, citizen panels may be able to maintain some of their initial strength in this area. Increased involvement of juvenile court judges in cases where little or no progress is made could motivate some parents to meet specified objectives and speed up the process of terminating parental rights when no progress has been demonstrated within specified time periods. The data also indicate a need for some adjustment to the process used to involve parents in case reviews. Another potentially positive outcome was highlighted during interviews with the juvenile court judges and the DFCS staff in the three study counties. Many of these respondents believed that the process had the potential for moving children out of foster care more quickly than does the internal review process. In addition to this primary goal, however, respondents were excited about the potential for heightened community awareness and education as citizens come to understand more about the plight of foster children and family conditions that can lead to placement. Interviews with panel members themselves indicated a definite belief that the community needed to accept more responsibility for children in foster care. One panel member's comment reflects the general sentiment expressed by other respondents: "These are kids we used to call 'those kids,' but now they are 'our kids'." It is hoped that the judicial-citizen review process will help to create a community environment in which needed resources can be developed both to prevent placement and to provide more support for families and children when placement occurs. This is the sentiment of the three juvenile court judges and almost all DFCS staff members who were interviewed, when they asserted that they felt the CRP process should be continued and expanded statewide.(ABSTRACT TRUNCATED AT 400 WORDS)     

‘Kids who Smoke Think that They Can Be Adults as Well’: Children's Smoking and Transitions to Adulthood

This article aims to explore the ways in which preadolescents associate smoking with transitions to adulthood, in the context of sociological theories of childhood, using data from the Liverpool Longitudinal Study of Smoking. The research found that at age 9 many of the cohort argued that smoking was more acceptable for adults because they had bigger bodies than children. Some children also suggested that smoking was appropriate for adults because adults were competent to make important decisions and to balance risks. By age 11, when several of the cohort had actually tried smoking, children's views about the risks smoking posed to their bodies had altered, and many children were aware of smoking‐related disease among adults. The cohort also suggested that some children might take up smoking to demonstrate that they are ‘grown up’ too. In the UK, legal restrictions on the age of tobacco purchase are reinforced by social norms that construct smoking as an activity that is only suitable for adults. The goal of legal restrictions that ban the sale of cigarettes to children is to protect their health. The unintended outcome, however, is that for many young people smoking is a way of demonstrating maturity and adult status.     

Detecting covariates with non-random missing values in a survey of primary education in Madagascar

A major survey of the determinants of access to primary education in Madagascar was carried out in 1994. The probability of enrolment, probability of admission, delay before beginning school, probability of repeating a year and probability of dropping out were studied. The results of the survey are briefly described. In the analysis, one major problem was non-random missing values in the covariates. Some simple methods were developed for detecting whether a response variable depends on the missingness of a given covariate and whether eliminating the missing values would distort the resulting model. A way of incorporating covariates with randomly missing values was used such that the individuals having the missing values did not need to be eliminated. These methods are described and examples are given on how they were applied for one of the key covariates that had a large number of non-random missing values and for one for which the values appear to be randomly missing.