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关键词： Bus driver   Crash involvement   Safety climate   Fleet-level   Individual characteristics   Random-effects two-level logit model   BEHAVIOR QUESTIONNAIRE   DRIVING ANGER   AT-FAULT   ACCIDENTS   POPULATION   VALIDATION   PREDICTOR   FATIGUE   ANXIETY   STRESS  

摘要： Although traffic crashes involving buses are less frequent than those involving other vehicle types, the consequences of bus crashes are high due to the potential for multiple injuries and casualties. As driver error is a primary factor affecting bus crashes, driver safety education is one of the main countermeasures used to mitigate crash risk. In China, however, safety education is not as focused as it should be, largely due to the limited research identifying the specific driver behaviors, and potential influences on those behaviors, that are correlated with crashes. The aim of this study is, therefore, to explore the fleet- and driver-level risk factors underlying bus drivers? self-reported crash involvement, including analyzing the effect of psychological distress on the most influential driver-level factors. A survey was conducted of 725 drivers from a large Shanghai bus company, and a random-effects two-level logit model was developed to integrate fleet and individual variables. Results showed that: 1) the fleet-level safety climate explained about 8.5% of the model?s variance, indicating it was a valid predictor of self-reported crash involvement; 2) the driver-level factors of drivers? age, seniority, marital status, positive behavior, and driving anger influenced drivers? self-reported crash involvement, but ordinary violations, lapses, aggressive violations, and insomnia were the most influential variables; 3) psychological distress appeared to associate with the high frequency of risky driving behavior and the high severity of driving anger. This study?s findings will help bus companies to give more attention to their safety climate and implement more targeted improvements to their driver safety education programs.

关键词： Regional scale   Environmental factors   Biological soil crusts   Cover distribution   Development characteristics  

摘要： Biological soil crusts (biocrusts) are widely distributed in arid and semiarid ecosystems and provide critical ecological functions. Understanding how biocrusts change across broad regional scales allows us to manage them more effectively under changing climates and land-use pressures. Based on field surveys, we used boosted regression trees and correlation analysis to examine the changes in cover, distribution and developmental characteristics of biocrust mosses and cyanobacteria, and environmental factors at 40 sites in the Mu Us Sandland in northwestern China. We found that higher elevation sites (similar to 1342 m) were the most suitable for biocrust distribution, and preferred sites were characterized by greater vegetation cover (>43%), values of the aridity index (>0.34), slope (>6.61, soil pH (>8.85) and soil organic carbon (>0.50%). Increasing levels of disturbance (>1.15 kg dung ha(-1)) suppressed biocrusts. Moss crust development (e.g., biomass, thickness, bulk density) was significantly positively related to vegetation cover, aridity index, and soil organic carbon, and moss crusts tended to prefer shady shrub communities at low elevations. Shady and steep (5 - 15 degrees) slopes and higher soil nutrient contents were positively correlated with cyanobacteria development. Reduced rainfall and increasing disturbance intensity would reduce the distribution and development of biocrusts. Our study provides a basis for informed decision making about how to manage moss and cyanobacterial crusts in the Mu Us Sandland as the region becomes hotter and drier.

关键词： Sleep apnea   Sleep-disordered breathing   Sleepiness   Professional drivers   Excessive daytime sleepiness   Epidemiology   MOTOR-VEHICLE CRASH   POSITIVE AIRWAY PRESSURE   WAKEFULNESS TEST   RISK   MAINTENANCE   POPULATION   EPIDEMIOLOGY   ASSOCIATION   PERFORMANCE   ACCIDENTS  

摘要： Introduction: The prevalence of obstructive sleep apnea (OSA) among professional truck drivers has varied from 28 to 78% in previous studies. In this study we wanted to estimate the prevalence of OSA and OSA with both subjectively measured sleepiness and objectively measured ability to stay awake (ie obstructive sleep apnea syndrome, OSAS) among professional truck drivers in Finland. Subjects and methods: Altogether 2066 professional truck drivers received a structured questionnaire. 175 drivers had a clinical examination and sleep laboratory studies, which included respiratory polyg-raphy (RP) and maintenance of wakefulness test (MWT). Three groups were formed: 75 subjects with suspected sleep apnea, 75 healthy controls and a random sample of 25 subjects. Results: 1095 drivers answered the questionnaire. RP was performed on 172 drivers and 167 drivers participated in MWT. The mean age was 40.7 years and the mean BMI was 27.7 kgm(-2). The prevalence of sleep apnea in professional truck drivers using various criteria were: AHI >= 5: 40.1%, AHI >= 15: 16.2% and, AHI >= 30: 7.2%. The prevalence depended on clinical history. Prevalence of AHI >= 5 varied between 20 and 56.9% and prevalence of AHI >= 15 was 4.3-25%. Altogether 4.8% of subjects with AHI >= 15 had abnormally short sleep latency in MWT (<19.4 min). Conclusions: Moderate sleep apnea is common among professional truck drivers but significant inability to stay awake, defined as MWT <19.4 min, is found in about one of twenty professional drivers. (C) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://***/licenses/by/4.0/).