WalkSafe: a school-based pedestrian safety intervention program

OBJECTIVE: To evaluate the effectiveness of the WalkSafe program, an elementary school-based pedestrian safety program in a single high-risk district in Miami-Dade County. METHODS: Sixteen elementary schools were identified in a single high-risk district and enrolled in a one-year study. All schools implemented the WalkSafe program on the last week of January 2003. A pre, post, and three-month post testing of pedestrian safety knowledge was conducted. An observational component was also implemented at four schools that were randomly chosen. Engineering recommendations and law enforcement initiatives were also performed. RESULTS: A total of 6467 children from K-5th grade from 16 elementary schools participated in the program. Of these 5762 tests were collected over three different testing times. A significant difference (p-value < 0.001) was found between the pre and post testing conditions across all grade levels. There was no significant difference found between the post and three-month post testing conditions across all grade levels (p-value > 0.05). The observational data collected at four schools across the different testing times demonstrated a significant difference found between pre and post testing conditions for Group A (stop at the curb and look left, right, left) and also for Group B (midstreet crossing and darting out) (p-value < 0.05). There was no difference found between comparing the pre-test or post-test condition with the three-month post-test time. There were many environmental modifications that were recommended and actually performed. CONCLUSION: The WalkSafe program implemented in a single high-risk district was shown to improve the pedestrian safety knowledge of elementary school children. The observational data demonstrated improved crossing behaviors from pre-test to post-testing conditions. Future research will focus on sustaining the program in this district and expanding the program throughout our county.     

Assessing interactions,predicting function,and increasing degradation potential of a PAH-degrading bacterial consortium by effect of an inoculant strain

Environmental Science and Pollution Research - A natural phenanthrene-degrading consortium CON was inoculated with an exogenous strain Sphingobium sp. (ex Sp. paucimobilis) 20006FA yielding the...     

Gypsum Waste Disposal: Land vs Sea or Recycling

The disposal of waste gypsum wallboard at landfill sites in British Columbia (B.C.), Canada, resulted in the generation of hydrogen sulphide gas and toxic leachates. Although some remedial measures were taken to reduce or eliminate problems resulting from past dumping practices, many landfill operators refused to accept new waste for fear of litigation over the pollution of nearby streams and rivers. with the availability of legitimate disposal sites greatly reduced, a serious waste management problem arose. the two most promising options for reducing the accumulating waste appeared to be recycling and ocean disposal.

Agricultural use of the waste for soil conditioning would account for only a small portion of the waste generated annually. Manufacturing plants were reluctant to accept waste gypsum with a high paper fibre content for fear it would lower the quality of the new wallboard product or interfere with the existing equipment and processes in the plants. the technology for economically removing and separating the paper from the used or substandard wallboard had yet to be developed.

The environmental implications of disposal at sea were assessed by a government advisory committee under the provisions of the Canadian Environmental Protection Act. Although results of a test dump in internal waters of B.C. were positive, the committee felt that valuable amenities of nearshore waters would only be assured by restricting dumping to a remote offshore location. an acceptable disposal method with minimal impact on the marine environment was eventually found with appropriate pretreatment of the waste and the use of remotely controlled bottom dump scows. Recent progress in the processing of waste wallboard to make it acceptable to the manufacturing industry should significantly reduce if not eliminate the need to dispose of gypsum wallboard wastes at sea.     

Ambient ozone (O3) in three Class I wilderness areas in the northeastern USA: measurements with Ogawa passive samplers

Ambient ozone (O(3)) was measured in two Class I wilderness areas, one within the White Mountain National Forest in north central New Hampshire (NH) and one within the Green Mountain National Forest in southwestern Vermont (VT), for six weeks between 5 July and 16 August 1994, using Ogawa passive nitrite-coated filter samplers and a one week exposure period each time. Results for 7-day mean ambient O(3) concentrations from the passive samplers were compared to results from a co-located continuous ultraviolet photometric O(3) analyzer both in NH and VT. Although the size of the data set was small, agreement through simple linear regression between mean 7-day O(3) concentrations determined by the continuous monitors, and those obtained from the passive samplers was generally very good (adjusted R(2) = 0.759; p = 0.0003). Overall, excluding the one outlier value, any observed differences in the results obtained by the two methods when comparing co-located passive samplers to the continuous monitor within a given study location, appeared to be solely due to experimental error.     

Evidence of the involvement of plant ligno-cellulosic structure in the sequestration of Pb: an X-ray spectroscopy-based analysis

European walnut (Juglans regia) plants were grown in pots, on peat soil contaminated with lead (Pb), for four years. European walnut was chosen because it grows in Mediterranean climates, it yields a high biomass, and a fine quality wood. In the above ground parts Pb concentration was 1000 times lower than in roots: in 50 g roots there was 450 mg of Pb. Microanalysis of roots found in periderm more than 50% of the total root Pb. Pb L(III) EXAFS spectroscopy was performed on: root powder from Pb-exposed plants, Pb-impregnated cellulose and lignin. Comparison of plant material with lignin and cellulose helped to envisage a plant disposal strategy for Pb. This may consist in establishing links with large organic molecules, which are abundant constituents of cell walls. EXAFS spectroscopy evidenced the presence of Pb-O bindings within the ligno-cellulosic structure in roots. Lead was scantly conveyed to the shoots, giving to walnut plants an added asset in Pb phytostabilization.     

Diel movement patterns of the scalloped hammerhead shark (Sphyrna lewini) in relation to El Bajo Espiritu Santo: a refuging central-position social system

Summary Movement patterns of scalloped hammerhead sharks in the vicinity of El Bajo Espiritu Santo, a seamount in the Gulf of California, were determined by tracking by ultrasonic telemetry 13 sharks and marking 100 sharks. The 13 tracked sharks swam back and forth along the seamount ridge throughout the day. They did not swim in different directions to reduce swimming effort when currents changed from a parallel to a perpendicular orientation to the ridge. Sharks tracked up to 8 km away into the pelagic environment soon returned to the seamount. From such trackings and repeated observations of marked sharks over periods of several weeks, it is believed that most sharks disperse and return to the seamount in a rhythmical fashion. The separate departures of individual hammerheads in five paired trackings indicated that the sharks left the seamount either in small groups or singly. For these reasons, we argue that the social system of the scalloped hammerhead shark can be described as a refuging system.     

Optimisation algorithms for spatially constrained forest planning

We compared genetic algorithms, simulated annealing and hill climbing algorithms on spatially constrained, integrated forest planning problems. There has been growing interest in algorithms that mimic natural processes, such as genetic algorithms and simulated annealing. These algorithms use random moves to generate new solutions, and employ a probabilistic acceptance/rejection criterion that allows inferior moves within the search space. Algorithms for a genetic algorithm, simulated annealing, and random hill climbing are formulated and tested on a same-sample forest-planning problem where the adjacency rule is strictly enforced. Each method was randomly started 20 times and allowed to run for 10,000 iterations. All three algorithms identified good solutions (within 3% of the highest found), however, simulated annealing consistently produced superior solutions. Simulated annealing and random hill climbing were approximately 10 times faster than the genetic algorithm because only one solution needs to be modified at each iteration. Performance of simulated annealing was essentially independent of the starting point, giving it an important advantage over random hill climbing. The genetic algorithm was not well suited to the strict adjacency problem because considerable computation time was necessary to repair the damage caused during crossover.     

Book reviews

The Economics of Art and Culture: An American Perspective

James Heilbrun & Charles M. Gray

New York, Cambridge University Press, 1993, 378 pp., £14.95 pb

Building Cities that Work

Edmund Fowler

Montreal & Kingston, McGill‐Queen's University Press, 1992, 315 pp.

Interactive Decision Making: The Graph Model for Conflict Resolution

Liping Fang, Keith W. Hipel & D. Marc Kilgour

New York, Wiley, 1993, 221 pp., £49.50

The Politics of Nature: Explorations in Green Political Theory

Andrew Dobson & Paul Lucardie (Eds)

London, Routledge, 1993, 240 pp. + xv, £37.50

Urban Transport in Asia: An Operational Agenda for the 1990s, World Bank

Technical Paper No. 224

Peter Midgley

Washington, DC, The World Bank, 1994, 98 pp.

Landscape Ecology: Theory and Application, 2nd edition

Zev Naveh & Arthur Lieberman

New York, Springer‐Verlag, £34.50