Investigations of the urban street tree forest of Mendoza, Argentina

The investigation of the urban street trees was undertaken in the oasis city Mendoza, Argentina. The analysis included 1,680 urban street trees in their structure (species, age, and spatial structure), vitality and irrigation conditions. A questioning of 120 residents analysed the perception and acceptance of the urban trees by urban dwellers. Different urban structures, residential, commercial and residential mixed structures and the city centre were investigated. The results show clearly the insufficient maintenance of the trees (composition, aging, irrigation, pruning etc.) and damaged irrigation system with leads to a loss of vitality. The questioning showed that easily recognisable problems (insufficient pruning etc.) are more reflected by people than long term problems (irrigation). There is a different reflection of urban street tree problems in the different urban areas, related to status, information level and management. The maintenance and relation to urban street trees was best in the residential area. Not only better maintenance of the trees but also a clearer recognition of street tree problems by residents and by the responsible municipal institutions is urgently needed. A public-private partnership and more environmental education could help to overcome the problems.     

The Missing Link: Deficits of Country-Level Studies. A Review of 22 Articles Explaining Life Satisfaction

To explain country differences in an analytical or structural dependent variable, the application of a macro–micro-model containing contextual hypotheses is necessary. Our methodological study examines whether empirical studies apply such a model. We propose that a theoretical base for country differences is well described in multilevel studies, but aggregate and individual data analyses fail to specify contextual hypotheses ex ante (in the theory section of an article) and instead elaborate on macro–micro explanations ex post (in the discussion section). To test our assumptions, we analyzed 22 studies published in journals cited in the Social Science Citation Index between 2007 and 2010, which compare countries with respect to life satisfaction. Results are in accordance with our expectations. We conclude that cross-country comparisons should apply a macro–micro-model theoretically and empirically, if possible, and include the meso level, if appropriate. In case of insufficient data (i. e. only individual level or aggregate level data), applying a macro–micro-model theoretically may prevent premature conclusions.     

Quadratic estimation in mixed linear models with two variance components

Explicit expressions for Bayes invariant quadratic estimates, biased and unbiased, are presented and proved to cover the entire class of admissible estimates in the considered classes. An unbalanced genetic model is studied for demonstration.     

Room assignment-rent division: A market approach

A group of friends consider renting a house but they shall first agree on how to allocate its rooms and share the rent. We propose an auction mechanism for room assignment-rent division problems which mimics the market mechanism. Our auction mechanism is efficient, envy-free, individually-rational and it yields a non-negative price to each room whenever that is possible with envy-freeness.We would like to thank seminar participants at Barcelona, Boston College, Duke, Koç, Málaga, MIT, Michigan, NYU, conference participants at the First Brazilian Workshop of Game Theory Society (Sao Paulo 2002), SED 2002-Conference on Economic Design (New York City 2002), The Sixth International Meeting of the Society for Social Choice and Welfare (Pasadena 2002), an anonymous referee for their comments and Ahmet Alkan, Selçuk Karabati, Bari Tan, nsan Tunali for insightful discussions. Sönmez gratefully acknowledges the research support of KoçBank via the KoçBank scholar program and Turkish Academy of Sciences in the framework of the Young Scientist Award Program via grant TS/TÜBA-GEBP/2002-1-19. Any errors are our own responsibility.     

Effects of multicomponent training on functional fitness in older adults

The purpose of this study was to evaluate the effects of a 9-week supervised multicomponent exercise program on functional fitness and body composition in independent older adults. Forty-two adults age 60-86 years were randomly assigned to an exercise or a control group and were evaluated before and after training. The training program consisted of 3 sessions of walking, strengthening, and flexibility exercises per week. The multicomponent training program resulted in significant (p < .005) improvements on the chair stand, arm curl, 6-min walk, and up-and-go tests. The findings of this study indicate that a 9-week training program increased upper and lower body strength, aerobic endurance, and agility/dynamic balance in older adults. The most affected components of functional fitness were lower body strength and aerobic endurance. There was no effect of the 9-week training on body composition.