Contrasting strategies for tree species to cope with heat and dry conditions at urban sites

Street trees planted at tree pits with impermeable pavements are exposed to a high level of both, atmospheric and edaphic stress. For many species tree physiology, optimal growth, and consequently long-term vitality may be hampered under these harsh conditions. Therefore, maintaining the vitality and promoting the ecosystem services provided by urban trees, for example aesthetic values and microclimatic benefits, it is important to establish trees with a high tolerance to stressful urban environments. Measurements of leaf gas exchange, leaf water potential, leaf surface temperature and chlorophyll-fluorescence were used for identification of specific response of Corylus corluna L., Ginkgo biloba L., Liriodendron tulipifera L., and Tilia cordata Mill. ‘Greenspire’. The summer months in 2013 with a period of heat and drought over eight weeks only interrupted by two rainy days were appropriate to access tree’s strategies to cope with low water availability. During the measurement period, the influence of high temperatures, high values of vapor pressure deficit (VPD) and low soil water availability on stomatal conductance, water-use efficiency (WUE) and leaf water potential (Ψmin, Ψmax ) was highest for Liriodendron followed by Ginkgo. These species showed high reductions in WUE in case of higher air temperatures and high values of VPD. Results indicate an avoidance strategy under increasing heat and VPD. In contrast, Corylus and Tilia followed a tolerance strategy indicated by decreasing values of Ψmin and lower reductions of WUE. In conclusion, wide species-specific variation in response to high temperatures and high VPD indicates that substantial potential exists in the selection for dry and hot urban places.     

A Community Response to Tragedy: Individualized Services for Families

The murder of a 13-year-old young woman mobilized one community to initiate a wraparound service model for their most hard-to-reach families. These families struggled with parental substance abuse, youth at high risk, and associated complex needs cutting across existing categorical programs. The strength and empowerment based program, in which interventions were designed specific to each family, presented challenges in evaluating outcomes with traditional standardized instruments. This paper describes the project, its outcomes for families and youth, and the evaluation design that evolved to measure outcomes in a strength-based program with no uniform intervention.     

6 Three Perspectives on Team Learning

Abstract

The emergence of a research literature on team learning has been driven by at least two factors. First, longstanding interest in what makes organizational work teams effective leads naturally to questions about how members of newly formed teams learn to work together and how existing teams improve or adapt. Second, some have argued that teams play a crucial role in organizational learning. These interests have produced a growing and heterogeneous literature. Empirical studies of learning by small groups or teams present a variety of terms, concepts, and methods. This heterogeneity is both generative and occasionally confusing. We identify three distinct areas of research that provide insight into how teams learn to stimulate cross-area discussion and future research. We find that scholars have made progress in understanding how teams in general learn, and propose that future work should develop more precise and context-specific theories to help guide research and practice in disparate task and industry domains.     

Problems of points of inflection in trend functions as described by a model for the forecast of brand shares

Trends often have special points of uncertainty (surprises) which make forecasts by trend extrapolation impossible. Such points of uncertainty are found especially at points of inflection of functions. In many cases it will be possible to decompose the trend to be forecast into two or more (causal) time series which have no points of inflection. By extrapolating these individual time series it will then be possible to predict the trajectory of the trend function inclusive of the point of inflection. This method is represented and critically discussed by means of an example for the forecast of a brand share.Werner Kroeber-Riel, Dr. rer. pol., is full professor of business and head of the Institute for Research in Consumption and Behavior at the University of the Saar in Saarbrücken.Sighard Roloff is a certified mathematician and assistant at the Institute for Research in Consumption and Behavior at the University of the Saar in Saarbrücken.This contribution first appeared under the title: Zur Problematik von Wendepunkten in Trendfunktionen, dargestellt an einem Modell zur Prognose von Marktanteilen, Zeitschrift für betriebswirtschaftliche Forschung 24 (1972) 294–300.     

Church suppers,pony tails and mentors: Developing a program for street kids

Increasing number of teens are leaving their homes to live on the street, and communities are often confused as to how best to provide services for them. This article describes one community's response to this and the lessons learned. The program, its development, the services and the communication with other agencies are described.This research was funded in part by grants from the Juvenile Justice Delinquency Prevention Funds.Ms. Roloff is affiliated with the program, Crosswalk.     

“A Geography of Disparate Spirits”: Pathology as Oppression in “A Woman is Talking to Death” and “Mental”

This article foregrounds Judy Grahn's commitment to social justice and chiefly considers her nine-part poems: “A Woman is Talking to Death” and “Mental.” These poems illuminate the socially constructed nature of mental illness and challenge readers to consider how and why the characters within them are deemed mentally ill. Little, if any, scholarship has been devoted to using Grahn's poetry, and particularly “Mental,” as a framework for analyzing the pathologization of people, especially women, relative to the system of mental health. Her work remains relevant to critical conversations that illuminate contemporary issues of oppression that still haunt us today.