Effects of uncertainty, transmission type, driver age and gender on brake reaction and movement time

PROBLEM: Braking time (BT) is a critical component in safe driving, and various approaches have been applied to minimize it. This study analyzed the components of BT in order to assess the effects of age, gender, vehicle transmission type, and event uncertainty, on its two primary components, perception-reaction time and brake-movement time. METHOD: Perception-reaction time and brake-movement time were measured at the onset of lights for 72 subjects in a simulator. The six experimental conditions were three levels of uncertainty conditions (none, some, and some + false alarms) and two types of transmission (manual and automatic). The 72 subjects, half male and half female, were further divided into three age groups (mean of 23, 30, and 62 years). Each subject had 10 trials in each of the three levels of uncertainty conditions. RESULTS: Transmission type did not significantly affect either perception-reaction time or brake-movement time. Perception-reaction time increased significantly from 0.32 to 0.42 s (P < .05) as uncertainty increased but brake-movement time did not change. Perception-reaction time increased (from 0.35 to 0.43 s) with age but brake-movement time did not change with age. Gender did not affect perception-reaction time but did affect brake-movement time (males 0.19 s vs. females 0.16 s). IMPACT ON INDUSTRY: At 90 km/h, a car travels 0.25 m in 0.01 s. Consequently, even such small effects multiplied by millions of vehicle-kilometers can contribute to significant savings in lives and damages.     

Age differences in safety attitudes and safety performance in Hong Kong construction workers

PROBLEM: Safety in the construction industry is a major issue in Hong Kong, representing about 46% of all occupational injuries in 1998. This study explored linear and curvilinear relations between age and safety performance (accident rates and occupational injuries), as well as safety attitudes, in construction workers in Hong Kong. METHOD: A Chinese version of the Safety Attitude Questionnaire (SAQ by Donald & Canter) was developed and administered to a sample of Chinese construction workers (N=374, 366 males, 8 females) from 27 construction sites. RESULTS: Accident rates were not related to age. Occupational injuries were related to age in a curvilinear manner, with injuries at first increasing with age, then decreasing. Two safety attitude scales were related to age with older workers exhibiting more positive attitudes to safety. If age and tenure are controlled, some attitude scales are predictors of safety performance. IMPACT ON INDUSTRY: Management/supervisors, team leaders, and workers are all responsible for safety, and any negative bias toward older construction workers is unfounded.     

渝东峡江区全新世环境考古与环境变迁研究现状

渝东峡江区全新世环境考古与环境变迁研究,目前的成果主要涉及部分遗址点的古环境复原、个别次流域环境变迁研究及初步建立的古洪水发生序列,在研究思路、方法和手段上仍需考虑区域特殊性并重视：①反映人地关系互动的环境考古研究,包括人类生存环境的生态条件、环境质量及人类对环境的影响能力方面;②遗址“次生堆积”的环境影响因素研究和“事件层”多成因分析;③遗址地层与自然地层的对比研究、区域环境考古及其比较研究;④区域古环境变化序列与全球变化区域响应研究;⑤确保获取高分辨率、满足多指标综合要求的沉积物样品。     

Crash rates over time among younger and older drivers in the SHRP 2 naturalistic driving study

Objective: To examine crash rates over time among 16–17-year-old drivers compared to older drivers. Methods: Data were from a random sample of 854 of the 3,500 study participants in SHRP 2, a U.S. national, naturalistic driving (instrumented vehicle) study. Crashes/10,000 miles by driver age group, 3-month period, and sex were examined within generalized linear mixed models. Results: Analyses of individual differences between age cohorts indicated higher incidence rates in the 16–17-year old cohort relative to older age groups each of the first four quarters (except the first quarter compared to 18–20 year old drivers) with incident rate ratios (IRR) ranging from 1.98 to 18.90, and for the full study period compared with drivers 18–20 (IRR = 1.69, CI = 1.00, 2.86), 21 to 25 (IRR = 2.27, CI = 1.31, 3.91), and 35 to 55 (IRR = 4.00, CI = 2.28, 7.03). Within the 16–17-year old cohort no differences were found in rates among males and females and the decline in rates over the 24-month study period was not significant. Conclusions: The prolonged period of elevated crash rates suggests the need to enhance novice young driver prevention approaches such as Graduated Driver’s Licensing limits, parent restrictions, and post-licensure supervision and monitoring. Practical Applications: Increases are needed in Graduated Driver’s Licensing limits, parent restrictions, and postlicensure supervision and monitoring.     

Crown condition dynamics of oak in southern Sweden 1988’999

Crown defoliation of oak (Quercus robur and Q. petraea) was analysed in 808 trees during three forest condition surveys (1988, 1993, and 1999) in the southern Sweden. From 1988 to 1999 crown defoliation increased by more than 20%. Changes in crown defoliation were related to the pH in the upper 20–30 cm of the mineral soils, which was closely connected to other measures of soil fertility (cation exchange capacity, CEC and C/N ratio). Trees growing on soils with a high pH (≥4.00, in BaCl₂ filtrate), high CEC and low C/N ratio had significantly lower crown defoliation than trees growing on more acid soils (pH <4.00), indicating that less favourable soil conditions may further enhance oak decline. Age did not differentiate trees with respect to crown defoliation, indicating that decline in crown condition was not due to an age-related increase in crown transparency. Considering only trees younger than 100 years, a significant interaction was observed between changes in crown defoliation and soil pH. Trees younger than 100 years old growing on more acidic soils had a greater increase in crown transparency than trees on more basic soils between 1988 and 1999. Trees ≥100 years old had significantly higher defoliation on more acidic than on more basic soils, however defoliation dynamics of these trees over 1988–99 was not related to soil acidity. Two biotic agents (insect and fungal leaf infections) evaluated in this study did not prove to be important drivers of defoliation dynamics.     

Slow growth of Empetrum nigrum in industrial barrens: combined effect of pollution and age of extant plants

We studied the impact of industrial pollution on population demography (age structure), growth and reproduction of crowberry, Empetrum nigrum L. Crowberry growing in severely polluted sites near non-ferrous smelters (at Harjavalta, Monchegorsk and Nikel) was on average twice as old as in unpolluted habitats, as indicated by the number of annual rings at root collar. Shoot length decreased both with plant ageing and due to pollution impact, while neither the proportion of generative plants nor berry production was affected by pollution or plant age. Our results suggest that death of the extant individuals of E. nigrum near the non-ferrous smelters is to a large extent explained by age-related damage of the main stem accelerated by pollution. Since vegetative propagation, seed germination and seedling establishment are hampered by soil toxicity, E. nigrum populations near the smelters continue to decline with ageing in spite of the gradual decline of emissions.     

Health, safety, self-regulation and the older driver: It's not just a matter of age

Problem

The purpose of this research was to examine the impact of age and health on patterns of driving and self-regulation among older adults who still drive.

Method

This analysis presents the results of a nationwide survey of drivers who are 50 + (N = 3,824, 53.11% response rate), focusing on questions about the impact of their self-reported health on attitudes toward and self-regulation of driving.

Results

The data indicate that as age increases, so too does reported self-regulation of driving, increasing sharply among those ages 70 and older. The data also indicate that respondent's reported confidence in driving and their enjoyment of driving decline as they age. Health status bears a significant relationship with all three of these variables, positively related to confidence in driving skills and to enjoyment in driving, but negatively related to self-regulation reports. As self-reported health declines, respondent's report engages in greater voluntary restrictions of their driving.

Discussion

All too often, the driving decision is linked primarily to chronological age. Analysis done here indicates that age alone is not the best indicator of self-regulation and how older adults change their driving behaviors.

Summary

This research presents the results of a nationwide survey of 50+ drivers and their self-reported driving, self-regulation behaviors, and health status. Strong support was found for the argument that chronological age is not an adequate measure of self-regulating behaviors and driver safety among those 50+. In particular, it was found that a person's health status and the interaction between age and health are essential considerations in the decisions around self-regulation and driving. People tend to self-regulate more with age, but the effect becomes much more pronounced as health status declines.

Impact on industry

In the coming years, if older adults can't get to where they want to go and continue to be viable consumers in our national fabric, all industries will eventually suffer. Transportation is a key component to the nation's social contract with older individuals and their families.     

A Dynamic model of Cs accumulation by fish of different age classes

A dynamic model of radionuclide accumulation in fish is developed. In the model, the fish population is represented by a set of discrete age classes. Each age class is characterized by a specific growth rate, diet and activity of metabolic processes. The model describes all known types of size effect in the contamination of fish with radiocaesium. The detailed dynamics of ¹³⁷Cs accumulation by fish are demonstrated using the results of the model's application to ichtiofauna in a water body which has a high level of contamination with radiocaesium — namely, the cooling pond of the Chernobyl NPP.     

Informational governance – A systematic literature review of governance for sustainability in the Information Age

The rapid developments in all kinds of new information technologies, information networks and social media are increasingly affecting societies around the world. The so termed Information Age not only influences social relationships, economy and science, but also governance. Against this background and in the specific field of sustainability, informational governance is an emerging concept. It addresses two interrelated processes: (1) new forms of governing through information, and (2) transformative changes in governance institutions due to the new information flows. The aim of this article is to gain more insights into ways in which the Information Age impacts sustainability, and to suggest a research agenda with relevance to the field of informational governance. A systematic literature review resulted in a selection of 39 articles, of which 23 and 16 articles were identified in two-parallel searches. The increased human interconnectedness through e-governance, self-organization, private governing and empowerments are identified as core informational governance trends dealing with sustainability in the Information Age, and essential to future research.     

矿井风流年龄与矿井空气品质分析

矿井空气品质是矿井通风理论的新思路，是人们认识矿井空气环境的一种科学方法。通过对矿井风流年龄与矿井空气品质分析，重点论述和讨论了矿井风流年龄的定义及其计算；矿井风流污染物的定义，通风分支均匀释放污染物时分支空气污染物浓度的计算，局部集中散发污染物的分支污染物浓度计算；矿井空气品质的定义，任意分支空气品质的计算，分支汇合点的空气品质计算；研究了矿井风流空气品质随时间、空间变化的动态性，分析了矿井空气品质与矿井风流年龄及污染物的关系。矿井空气品质是矿井通风设计和评价矿井风流质量的重要理论依据