Water sources of urban trees in the Los Angeles metropolitan area

In semi-arid cities, urban trees are often irrigated, but may also utilize natural water sources such as groundwater. Consequently, the sources of water for urban tree transpiration may be uncertain, complicating efforts to efficiently manage water resources. We used a novel approach based on stable isotopes to determine tree water sources in the Los Angeles basin, where we hypothesized that trees would rely on irrigation water in the soil rather than develop deep roots to tap into groundwater. We evaluated the oxygen (δ¹⁸O) and hydrogen (δD) isotope ratios of xylem water, irrigation water, soil water, and groundwater in a study of temporal patterns in water sources at two urban sites, and a study of spatial patterns at nine urban sites and one “natural” riparian forest. Contrary to our hypothesis, we found that despite frequent irrigation, some trees tap into groundwater, although in most species this was a small water source. Some trees appeared to be using very shallow soil water at <30 cm depth, suggesting that these mature urban trees were quite shallowly rooted. In the natural site, trees appeared to be using urban runoff in addition to shallow soil water. We were able to identify tree uptake of precipitation at only 3 sites. The results show that some irrigated trees utilize groundwater and do not rely solely on irrigation water, which may make them able to withstand drought and/or water conservation measures. However, some irrigated trees may develop very shallow root systems, which may make them more susceptible.     

‘Closing the Gap’ in Indigenous life expectancies: what if we succeed?

In 2007–2008 the Council of Australian Governments agreed to six ambitious targets for addressing longstanding disparities between Indigenous and other Australians in health, education and employment outcomes. The ‘National Integrated Strategy for Closing the Gap on Indigenous Disadvantage’ (colloquially ‘Closing the Gap’) includes the goal of eliminating life expectancy gaps within a generation. This policy says nothing about what changes in the demographic structure of the population might be expected should there be even partial success towards this ambitious target. Information is required to analyse age and sex shifts for their effects on service demand and provision. In this study we apply cohort component projections modelling to the Northern Territory, the Australian jurisdiction with the largest Indigenous component in its population and the largest life expectancy gaps, to assess the demographic effects of closing the gap within a generation. Three scenarios are modelled: (1) No changes to Indigenous life expectancies from those estimated in 2010; (2) Complete success in closing the gap within a generation; and (3) A continuation of current forecasts about how Indigenous life expectancies will change into the future. Although closing the gap would only produce a small increase in the size of the next generation’s Indigenous population, over and above that projected with lower life expectancy scenarios, it would result in substantial changes in age compositions, with associated shifts in various demographic indices. These are pertinent to the planning and funding of core services into the future.     

Tweeting democracy? Examining Twitter as an online public relations strategy for congressional campaigns’

Considering the integral relationship between public relations and democracy (Martinelli, 2011) coupled with the growing use of social media for democratic aims (Smith, 2011) the current study examines the effectiveness of Twitter as a public relations communications tool for congressional campaigns. Specifically, as a means of testing Twitter's effectiveness in informing and engaging voters, congressional candidate and political party Twitter use for all 435 U.S. House of Representatives races (N = 1284) are compared with 2010 election outcomes. Results indicate that candidates’ Twitter use significantly increased their odds of winning, controlling for incumbency and Party ID. Additionally, significant differences between incumbents’ and challengers’ Twitter use during the election cycle emerged, which has important implications for public relations practices aimed at achieving democratic outcomes.     

When Infants Lose Exclusive Maternal Attention: Is It Jealousy?

To characterize infant reactions to jealousy evocation, 94 6‐month‐olds and their mothers were videotaped in an episode where the mothers directed positive attention toward a lifelike doll, and in 2 contrasting interactions: face‐to‐face play and a still‐face perturbation. Cross‐context comparisons of affects and behaviors revealed that jealousy evocation responses were distinguished by diminished joy and heightened anger and intensity of negative emotionality, comparable to levels displayed during the still‐face episode; heightened sadness, with durations exceeding those displayed during still‐face exposure; and an approach response consisting of interest, looks at mother, and diminished distancing, which was more pronounced than that demonstrated during play. Infants' heightened anger and sadness during jealousy evocation correlated with heightened maternal sensitivity and dyadic vocal turn‐taking, respectively, during play; and infants' diminished joy and interest during jealousy evocation were associated with heightened maternal withdrawal and intrusiveness, respectively, during play. Both fear and mother‐directed gaze were greater in girls. The discussion argues for interpreting the infant's mixed and agitated reaction to jealousy evocation as evidence of jealousy.     

Evidence-based Medicine and Child Mental Health Services

There is increased focus on using research evidence to guide clinical practice in the provision of child mental health services, to allocate resources and to make policy decisions. Emphasis has been placed on randomised controlled trials, which are clearly vital. However, given the complexity of children's lives and the multiple systems relevant to their care, it is important to consider alternative research designs and to think creatively about outcomes. In the context of difficulties with random allocation a number of quasi-experimental designs are described that may more closely reflect actual clinical work. In the context of ecological theory, the importance of taking a systems level approach to evaluation is highlighted, with examples from the US. Finally, the ways in which qualitative outcomes measures can be used to sensitively describe the effects of treatment are outlined, and their potential for giving voice to children and families as consumers of mental health services. These suggestions aim to lessen the tension between the requirements of the scientific investigations of treatment effectiveness and the realities of clinicians' daily experiences.     

Outcome Expectancies and Risk Behaviors in Maltreated Adolescents

This study examined positive and negative outcome expectancies for risk behaviors, and their association with engagement in risk behaviors, in a sample of 149 maltreated adolescents. “Outcome Expectancies” are evaluative social cognitions about what will occur as a consequence of one's actions. Risk behaviors and outcome expectancies for substance use, sexual behavior, and delinquency were assessed. In all regression models, positive expectancies were significantly related to risk behaviors while negative expectancies, with one exception, were not significantly related. In three of four regression models, significant interactions were found between positive and negative expectancies in predicting risk behaviors. The nature of the interaction differed by type of risk behavior. Beyond demonstrating associations between outcome expectancies and risk behaviors in a maltreated sample, this paper contributes to the study of social information processing by demonstrating significant interactions between positive and negative expectancies.     

Maternal Welfare and Employment Experiences and Adolescent Well-Being: Do Mothers' Human Capital Characteristics Matter?

Using a representative sample of over 900 low-income urban families from the Three-City Study, analyses assessed whether maternal human capital characteristics moderate relationships between mothers' welfare and employment experiences and young adolescents' well-being. Results indicate synergistic effects whereby greater maternal education and literacy skills enhanced positive links between mothers' new or sustained employment and improvements in adolescent cognitive and psychosocial functioning. Greater human capital also enhanced the negative links between loss of maternal employment and adolescent functioning. Mothers' entrances onto welfare appeared protective for adolescents of mothers with little education but predicted decreased psychosocial functioning among teens of more educated mothers. Results suggest that maternal human capital characteristics may alter the payback of welfare and work experiences for low-income families.