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.     

The Exploration of Role Induction as a Potential Method for Improving Men's Perceptions of Career Counseling

The authors explored the influence of role induction on men's perceptions of career counseling and attitudes toward seeking professional help. Two separate role inductions were presented to 268 male college students; the first discussed holistic career counseling, and the second integrated a discussion of male gender role socialization. Results demonstrated that participants who viewed the holistic role induction reported greater valuing of career counseling when compared with a control group. However, results indicated no difference in perceptions of career counseling between a holistic career counseling role induction and one that included socialized male perceptions of counseling.     

Multicultural Career Counseling: A National Survey of Competencies and Practices

Career counselors' multicultural competence has not been widely investigated. In this study, a national sample of 230 career counselors completed an online survey that included measures of career counseling self‐efficacy and multicultural counseling competence. Beyond these self‐report instruments, counselors responded to open‐ended items that requested specific examples of their actual multicultural counseling practices. Results indicated that counselors rated themselves as multi‐culturally competent, but those ratings were more closely linked to general career counseling self‐efficacy than to external evaluations of their self‐reported multicultural counseling practices. Findings also reinforced the importance of training and experience in developing multicultural competence.     

A critical review of the developmental approach to disability in South Africa

The article describes the policies, legislation, institutional structures and programmes of the developmental welfare system for physically disabled people in South Africa that have developed since 1994. In so doing, it examines resources and constraints and suggests ways in which improvements might be made following the experiences in the first 12 years of social development in South Africa. The author believes that it is timely to pursue this topic given the barriers experienced on the ground where social developers are attempting to empower and improve the circumstances of physically disabled people. Thus, this article should be of interest to policy makers, social planners, practitioners, human rights activists and disabled people alike.     

Role Induction in Career Counseling

Many vocational psychologists advocate addressing career as well as personal concerns in career counseling. However, some clients may have inappropriate expectations toward career counseling and may not be prepared or want to discuss personal issues. This study examined whether perceptions of the career counseling process could be modified with the use of role induction. Results indicated that, whereas role induction was associated with perceptions of students' own career concerns, gender was a strong influence in perceptions of counseling overall and in the stigma associated with a holistic perspective on career counseling.     

Academic and Career Development of Undocumented College Students: The American Dream?

Little is known about the academic and career decision‐making process for college students with undocumented status. This study used a multiple case study approach to explore how academic and work‐related decisions were made for 2 college students with undocumented citizenship status. Participants responded to a series of questions about their academic and career development. Data collected from these interviews were analyzed by a research team. After cross‐case analysis, 6 themes emerged: (a) barriers; (b) emotional impact; (c) resiliency, supports, and coping; (d) discrimination; (e) familial and cultural influences; and (f) academic, work, and career factors. Findings suggest that counseling professionals should attend to systemic, academic, and work‐related barriers that directly affect the educational and career decisions of students with undocumented citizenship status. Future research could expand on the present study by further exploring systemic and contextual factors that influence how undocumented students make academic and career choices using varied qualitative and quantitative methodologies.     

A comparative study of the water budgets of lawns under three management scenarios

The fate of irrigation in urban ecosystems is highly uncertain, due to uncertainties in urban ecohydrology. We compared irrigation rates, soil moisture, evapotranspiration (ET), stomatal conductance, and water budgets of landscape ecosystems managed with different turfgrass species and irrigation technologies. The “Typical” landscape had a cool-season fescue and was irrigated by an automatic timer. The “Alternative1” landscape had a warm-season paspalum and a “smart” soil moisture sensor-based irrigation system. The “Alternative2” landscape had a cool-season native sedge and a “smart” weather station-based drip irrigation system. ET was measured with a portable closed chamber and modeled using a Penman-Monteith approach, and the two methods agreed well. The water applied to the Alternative1 was 54 % less than the water applied to the Typical landscape, and the water applied to the Alternative2 was 24 % less. Soil moisture was similar in the Typical and Alternative2, while Alternative1 was drier in spring. The stomatal conductance of sedge was lower than the other two species, but its ET was not lower due to higher leaf area. Irrigation efficiencies (ET/applied irrigation) were 57 - 58 %, 86 – 97 %, and 78 - 80 % for the Typical, Alternative1, and Alternative2 landscapes, respectively. Runoff was less than 2 % in each landscape, and excess irrigation primarily drained below the root zone. Differences in irrigation efficiency between landscapes were due mainly to irrigation application, which varied more than species water use. Smart irrigation systems provided substantial water savings relative to a timer-based system, and prevented significant drainage losses. The utilization of smart sensors was more important than the choice of turfgrass species for irrigation efficiency.     

Weighted Estimator for the Linear Transformation Models with Multivariate Failure Time Data

In this article, a simple and efficient weighted method is proposed to improve the estimation efficiency for the linear transformation models with multivariate failure time data. Asymptotic properties of the estimators with a closed-form variance-covariance matrix are established. In addition, a goodness-of-fit test is developed to evaluate the adequacy of the model. The performance of proposed method and the comparison on the efficiency between the proposed method and the working independence method (Lu, 2005) are conducted in finite-sample situation by simulation studies. Finally a real data set from the Busselton Population Health Surveys is illustrated to validate the proposed methodology. The related proofs of the theorems are given in the Appendix.