STAyING ALIVE: STREET TREE SURVIVAL IN THE INNER-CITy1

A study was conducted from 1978 to late 1984 of the survival of inner-city street trees planted by the Oakland, California urban forestry program. The tree survival rate of approximately 60 to 70 percent from the trees planted in neighborhood parkways through urban forestry sponsored block parties contrasted sharply with less than one percent survival of trees planted earlier by the Model Cities program without community participation or ceremonial plantings. Explanations for the high tree survival were tested using participant observation, interviews with residents, and a small panel. Tree survival was not found to be related to the explanations provided by urban forestry ideology; namely, that residents had been educated to hold both instrumental and expressive values toward trees. Rather, the explanation appeared to be the function of an unintended solution to the issue of parkway ownership. The tree planting process which included species selection meetings and tree planting ceremonies tended to define the parkway trees as a resident's property, thus decreasing the significance of the parkway-property barrier. The generality of the Oakland illustration is discussed.     

CITIZEN PARTICIPATION: Project Renewal in Israel

ABSTRACT: This study on the development of citizen participation in Israel is based on the findings of a case study of Israel's Project Renewal, a comprehensive community renewal and development program which resembles Urban Renewal, Model Cities, and the War on Poverty programs in the US. The author reviews the characteristics of the Israeli political system which traditionally have denied a meaningful role for citizen participation. He compares the practice with the intent of Project Renewal to foster the participation of neighborhood residents. Finally, he comments on the unique v. the universal character of the Israeli experience with citizen participation: Will Israel follow the US pattern of increased citizen participation in community development programs?     

INTROGRESSING PHEROMONE QTL BETWEEN SPECIES: TOWARDS AN EVOLUTIONARY UNDERSTANDING OF DIFFERENTIATION IN SEXUAL COMMUNICATION

As a first step toward understanding how noctuid moths evolve species-specific pheromone communication systems, we hybridized and backcrossed two closely related moth species, Heliothis virescens (Hv) and H. subflexa (Hs), which differ qualitatively and quantitatively in their multi-component sex pheromone blends. We used amplified fragment length polymorphism (AFLP) marker-based mapping of backcross families to determine which of the 30 autosomes in these moths contained quantitative trait loci (QTL) controlling the percentages of specific chemical components in the pheromone blends. In two previous backcrosses to Hs, we found a strong depressive effect of Hv-chromosome 22 on the percentage of three acetate components in the pheromone gland. These acetates are present in Hs and absent in Hv. Here, we describe how we introgressed Hv-chromosome 22 into the genomic background of Hs. Selection for Hv-chromosome 22 started from backcross 3 (BC₃) females. All females that had Hv-chromosome 22 and a low percentage of acetates (< 3% of the total amount of pheromone components present) were backcrossed to Hs males. In BC₅ to BC₈, we determined whether Hv-chromosome 22 was present by a) running only the primer pairs that would yield the markers for that chromosome, and/or b) determining the relative percentages of acetates in the pheromone glands. Either or both genotype and phenotype were used as a criterion to continue to backcross these females to Hs males. In BC₉, we confirmed the isolation of Hv-chromosome 22 in the Hs genomic background, and backcrossed the males to Hs females to eliminate the Hv-sex chromosome as well as mitochondrial DNA. The pheromone composition was determined in BC₃, BC₅, and BC₁₁ females with and without Hv-chromosome 22. All backcross females with Hv-chromosome 22 contained significantly less acetates than females without this chromosome. In addition, BC₃ females with Hv-chromosome 22 contained significantly more Z11-16:OH than BC₃ females without Hv-chromosome 22. However, in BC₅ and BC₁₁ females, the correlation between Z11-16:OH and Hv-chromosome 22 was lost, suggesting that there are separate QTL for the acetates and for Z11-16:OH, and that the relative amount of the alcohol component is only affected in epistasis with other (minor) QTL. Now that we have succeeded in isolating the chromosome that has a major effect on acetate production, we can test in behavioral experiments whether the presence of acetates may have been a driving force for a shift in pheromone composition. Such tests are necessary to move towards an evolutionary understanding of the differentiation in sexual communication in Heliothis spp. moths.     

A QFT-type design methodology for a parallel plant structure and its application in idle speed control

Developed in this paper is a frequency domain design methodology for disturbance rejection in a MISO plant which has a special parallel structure. Shown in this paper is that it is not necessary to close all the parallel loops in order to achieve the hard time domain constraints. The proposed methodology is applied to the idle speed control of a fuel-injected engine.     

Analysis of robot positioning error

Positioning errors of robots used for material handling and assembly can be sufficiently large to cause problems. These errors are due to imperfect repeatability of the robots, and their effects can be ameliorated or exacerbated by tolerances on the workpieces and on the jigs and fixtures. In this paper, a model for characterizing the positioning errors of robots is developed. A statistical analysis of positioning error data is performed to make inferences about the stochastic nature of the robotic system. The basic issue is whether the positioning errors of the robot are state dependent or state invariant.     

Time dependent upward frequency shifts in the Orbitron MASER

In our experiments with the pulsed Oribtron MASER, we have noted that there is an upward chirp in frequency even though the anode voltage is decreasing. We have found theoretically that this is a natural consequence of the negative-mass instability and the chirp rate can be predicted from this theory. Experimental data we have obtained is also in good agreement with these predictions.     

Control Requirements for Control Systems: Matching Surety To Risk

Abstract

Auditing Software Development: A Manual With Case Studies, by S. Rao Vallabhaneni. John Wiley and Sons (605 Third Avenue, New York, 10158-0012), 1990, 439 pp. Includes a glossary and bibliography. Price: $75.00, plus shipping and handling charges.

Computer Crime: Techniques For Preventing And Detecting Crime In Financial Institutions, by Gregory Wold and Robert Shriver. Bankers Publishing (60 Gould Center, Rolling Meadows IL 60008), 1989, 255 pp. Includes a glossary. Price: $49, with a discount for BAI members.     

Optimal specialization of a maintenance workforce

This article develops an analytical method for determining an optimal specialization strategy for a maintenance workforce. The method assumes that maintenance tasks are generated by a system of statistically identical machines that experience random malfunctions and require periodic service. The impact of alternative workforce structures on system performance is evaluated with a queueing network model. Markov decision analysis is employed to determine an optimal assignment of maintenance personnel to pending tasks as the network status varies over time. A linear programming algorithm is derived to enable simultaneous optimization of specific assignment decisions and the overall workforce structure. A manufacturing example demonstrates the applicability of the method to many industrial contexts. The method is also applied to the problem of maximizing military aircraft sortie generation subject to a constraint on maintenance personnel expenditure.