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.     

可持续建筑的驱动力

对可持续建筑进行变革的潜在影响关系到建筑产业的权利、需要的驱动力,也关系到对可持续性理念的接受.这些影响务国之间会有关别.本文对主流部门的辞海进行了思考(从日渐广阔的角度),号召那里的建筑产业要有所不同:在基础设施、商业财产和提供住房方面.这个产业面临的挑战是要确定--发达国家和发展中国家都有份--能够实际操作的可持续建筑的概念,以及能为夺取可持续性做出巨大贡献的行动领域.客户越来越认可可持续性作为投资决策驱驱动力的积极经济成果.     

可持续建筑的驱动力

对可持续建筑进行变革的潜在影响关系到建筑产业的权利、需要的驱动力,也关系到对可持续性理念的接受.这些影响务国之间会有关别.本文对主流部门的辞海进行了思考(从日渐广阔的角度),号召那里的建筑产业要有所不同:在基础设施、商业财产和提供住房方面.这个产业面临的挑战是要确定--发达国家和发展中国家都有份--能够实际操作的可持续建筑的概念,以及能为夺取可持续性做出巨大贡献的行动领域.客户越来越认可可持续性作为投资决策驱驱动力的积极经济成果.     

Temporal changes in soil partitioning and bioaccessibility of arsenic, chromium, and lead

The hazard imposed by trace element contaminants within soils is dependent on their ability to migrate into water systems and their availability for biological uptake. The degree to which a contaminant may dissociate from soil solids and become available to a target organism (i.e., bioaccessibility) is therefore a determining risk factor. We used a physiologically based extraction test (PBET) to estimate the bioaccessible fraction of arsenic-, chromium-, and lead-amended soil. We investigated soils from the A and B horizons of the Melton Valley series, obtained from Oak Ridge National Laboratory site, to address temporal changes in bioaccessibility. Additionally, common extractions that seek to define reactive pools of metals were employed and their correlation to PBET levels evaluated. With the exception of Pb amended to the A horizon, all other treatments exhibited an exponential decrease in bioaccessibility with incubation time. The bioaccessible fraction was less than 0.2 mg kg(-1) within 30 d of incubation for As and Cr in the A horizon and for As and Pb within the B horizon; Cr in the B horizon declined to nearly 0.3 mg kg(-1) within 100 d of aging. The exchangeable fraction declined with incubation period and, with the exception of Pb, was highly correlated with the decline in bioaccessibility. Our results demonstrate limited bioaccessibility in all but one case and the need to address both short-term temporal changes and, most importantly, the soil physiochemical properties. They further reveal the importance of incubation time on the reactivity of such trace elements.     

Sociodemographic effects on place bonding

Patterns of amenity migration and recreational home development in much of the USA since the 1990s are changing the local sociodemographic make-up and the relationships formed among people and place. We use the psychological constructs of place attachment, place identity, and place dependence to assess differences in these relationships among new and long-time residents and absentee and local residents in three rural counties in the Inland Northwest. We measured place bonding using data from a mail survey of local (n = 531) and absentee (n = 239) property owners. We compared structural models suggested in the literature on the psychology of place, and found that a two-dimensional model representing place attachment and place identity was appropriate for both local and absentee property owners. Local owners exhibited stronger place attachment and place identity than absentee owners. Place bonding constructs were also substantially less impacted by the total number of years a property owner had resided on his or her property than by the number of months per year they lived on the property. The findings indicate that sociodemographic changes such as those manifested in second-home development may lead to a population that is less emotionally, behaviorally, and cognitively connected to the places in question, while sociodemographic changes from permanent in-migration may have a substantially smaller effect on place bonding.     

不锈钢导管挤压扩口工艺与模具设计

介绍了飞机不锈钢导管原位挤压扩口工艺和模具设计.该模具具有结构简单、易于加工、更换方便等特点,该工艺不仅适用于飞机导管修理,而且还可供其它设备导管修理时参考.     

Pediatric pedestrian trauma study: a pilot project

OBJECTIVE: To evaluate the implementation of the WalkSafe Program, a school based educational injury prevention program for children grades Kindergarten through 5. METHODS: A randomized comparative design was used for this study. The study was conducted in two high-risk urban school districts, which were chosen based on the geographic areas with the highest pedestrian injury and fatality rates. Four elementary schools (two in each district) were identified as potential study sites. Two intervention schools, one in each school district, were randomly chosen to receive the WalkSafe program; the other two schools served as controls, and received no intervention. The data was collected within the classroom setting for both the intervention and control schools. All elementary school children were administered the same pedestrian safety questionnaire as a pre-test, post-test and at three months following the intervention. RESULTS: A total of 2300 children participated in the WalkSafe program. The intervention (I) schools showed significant improvement in post-test scores then the control (C) schools (p = 0.012), and the (I) schools were able to maintain their test scores as reflected in a three-month follow-up evaluation (p = 0.47). Grades 3-5 of the (I) schools showed significant improvement in their test scores over grades K-2 (p < 0.0001). CONCLUSION: The WalkSafe program was shown to improve the pedestrian safety knowledge of elementary school children. Future research will include implementing the WalkSafe program at each elementary school within a single high-risk district.