三门湾近海有机污染对浮游细菌群落的影响

近海污染问题日趋严重,因此亟需评价污染对海洋环境造成的潜在影响.微生物作为对环境变化的首要响应者,可能作为评价污染水平的指示生物.为此,本文采集三门湾和邻近鱼山保护区共21个站点的表层海水,利用Illumina技术测定细菌16S rRNA基因,对比研究有机污染对浮游细菌群落的影响.三门湾的有机污染(A)为4.57±2.41,显著(P0.001)高于鱼山保护区0.43±0.74.三门湾和鱼山保护区的浮游细菌多样性和群落结构差异显著,其中三门湾水域的放线菌门(Actinobacteria)、α-变形菌纲(α-Proteobacteria)、β-变形菌纲(β-Proteobacteria)、SAR406的相对丰度显著高于鱼山保护区,而拟杆菌门(Bacteroidetes)、蓝细菌门(Cyanobacteria)、浮霉菌门(Planctomycetes)的相对丰度低于鱼山保护区.多元回归树分析(multivariate regression tree,MRT)发现浮游细菌多样性主要受pH、有机污染和叶绿素a(Chl-a)的影响,分别控制了27.7%、15.6%和6.7%的多样性变异.冗余分析(redundancy analysis)结果表明驱动细菌群落变异环境因子为有机污染、pH和盐度(salinity),共解释了14.8%的群落变异.同时,空间距离与细菌群落组成显著相关,解释了4.42%的变异,表明浮游细菌的空间分布不是随机的.此外,本研究筛选到与有机污染状况显著相关的23个细菌科,各科相对丰度的变化与其已知的生态功能特征相吻合,因此可以作为潜在的有机污染指示种群.本实验结果表明近海有机污染显著地改变了浮游细菌群落结构,特别是潜在病原菌丰度的增加;此外,筛选到敏感指示种群用于评估有机污染程度.     

晋北地区1986~2010年土地利用/覆被变化的驱动力

为定量研究不同时期区域土地利用变化的不同驱动特征,以地处农牧交错带的晋北地区为例,采用非监督分类与人工目视解译相结合的方法,获取研究区1986~2010年间的土地利用/覆被变化（LUCC）状况,采用典范对应分析（CCA）方法定量分析了不同阶段LUCC的自然与人为驱动特征.结果表明：1）CCA在分析长时期序列LUCC驱动力上有较好的解释力,CCA排序可以很好地提取LUCC与自然、人为因素之间的关系,反映不同时期土地利用变化受到的驱动作用;2）研究区土地利用类型以耕地、草地、林地为主,土地利用变化类型以耕地与草地、林地与草地之间的互相转移为主;3）从不同时期LUCC的驱动因子来看,人口密度、人均国内生产总值（GDP）、降水、坡度和高程是研究区各时期LUCC的主要驱动力;研究区在1986~1995年间LUCC的主要驱动力来自于人口增长和经济发展的需求,而随着时间的推进,坡度和高程等地形因素的驱动作用也愈来愈重要;4）从不同地类变化的驱动因子来看,耕地、草地等地类向居民用地、工矿用地转移的主要驱动力是人口和经济的发展;而林地,草地等土地覆被类型之间的转移主要受到坡度,高程和降水等自然因素的驱动.     

热活化镁砂的表征、吸附性能及其对含油废水的处理效果研究

通过对镁砂进行改性试图提高其吸附性能,并用于处理含油废水。对镁砂进行热活化处理,并对处理前后的镁砂进行了X射线衍射分析、TG-DSC热分析及扫描电镜分析。再将热活化后的镁砂用于处理模拟含油废水,考察了焙烧温度、吸附剂用量、pH、温度等因素对模拟含油废水中COD去除效果的影响。根据实验结果,确定镁砂的热活化温度为500℃,利用热活化后的镁砂吸附去除模拟含油废水中的COD,处理后出水COD浓度可满足GB 8978—1996《污水综合排放标准》一级标准。     

基于DPSIRM框架的区域水资源承载力综合评价

综合考虑影响水资源系统的资源、生态、环境、经济、社会等因素,论文通过对水资源系统内在机理研究,构建基于驱动力-压力-状态-影响-响应-管理（DPSIRM）概念框架的水资源承载力DPSIRM评价指标体系,给出各子系统明确的含义,以反映系统内部各要素之间的关系。在此基础上,将模拟退火算法用于投影寻踪优化,构建耦合SA-PP模型。并将模型应用于2003—2012年云南省水资源承载力综合评价,并分析投影特征值的历年变化特征。研究结果表明：2003—2012年云南省水资源承载力呈逐步上升趋势,即在当前社会经济发展水平下,云南省水资源承载力逐步增强,社会经济发展的规模处于水资源可支撑的规模范围内。2006年以前,水资源承载力呈加速增长趋势,其增长潜力较大。2006年以后,水资源承载力波动幅度较大,而2009和2011年年增幅趋于零。最佳投影方向各分量的大小反映了各评价指标对水资源承载力的影响程度,值越大则对应的评价指标对水资源承载力的影响程度越大。对水资源承载力影响程度最大的5项指标依次为：生活污水排放量、“三废”治理投资、人均GDP、单位GDP水耗和森林覆盖率。压力子系统对水资源承载力影响比重为26.15%,表明压力子系统是影响云南省水资源承载力的最重要因子。研究表明此模型具有实用性,可为区域水资源规划与管理提供科学决策依据。     

Improved recovery of repeat intoxicated drivers using fingernails and blood spots to monitor alcohol and other substance abuse

Objectives: This study reports the results of a pilot program in Kenosha County that used a combination of direct biomarkers extracted from blood spots and nails to monitor repeat intoxicated drivers for their use of alcohol and drugs with a detection window spanning from 3 weeks to several months. The objectives were to test whether the direct biomarkers phosphatidylethanol (PEth), ethylglucuronide (EtG), and 5 drug metabolites would (1) help assessors obtain a more objective evaluation of repeat offenders during the assessment interview, (2) allow for timely identification of relapses and improve classification of drivers into risk categories, and (3) predict recidivism by identifying offenders most likely to obtain a subsequent operating while intoxicated (OWI) offense within 4 years of enrollment in the program.

Methods: All (N = 261) repeat offenders were tested using PEth obtained from blood spots and EtG obtained from fingernails; 159 participants were also tested for a 5 drugs of abuse nail panel. Drivers were tested immediately after the assessment interview (baseline) and at 3, 6, 9, and 12 months after baseline. Based on biomarker results and self-reports of abstinence, offenders were classified into different risk categories and required to follow specific testing timelines based on the program's decision tree.

Results: The baseline analysis shows that 60% of drivers tested positive for alcohol biomarkers (EtG, PEth, or both) at the assessment interview, with lower detection rates (0–11%) for the 5 drug metabolites. The comparison of biomarkers results to self-reports of abstinence identified 28% of all offenders as high risk and assigned them to more frequent testing and more intense monitoring. The longitudinal analysis shows that 56% (completers) of participants completed the program successfully and the remaining 44% (noncompliant) terminated prematurely. Two thirds (68%) of the completers were able to reduce or control their drinking and one third relapsed at least one time during their mandated monitoring periods. After a brief intervention by the assessors, 79% of relapsers tested negative for biomarkers in their repeat tests. The rearrest analysis showed that offenders classified in the noncompliant and relapsers groups were 7 times more likely to receive a new OWI 4 years after enrollment compared to drivers classified as abstainers or controllers. Refractory drivers were monitored the longest and reported no subsequent rearrests.

Conclusion: These findings demonstrate the benefits of more individualized interventions with repeat OWI offenders and calls for further development of multimodal approaches in traffic medicine including those that use direct alcohol biomarkers as evidence-based practices to reduce recidivism.     

Using alcohol intoxication goggles (Fatal Vision® goggles) to detect alcohol related impairment in simulated driving

Objective: Fatal vision goggles (FVGs) are image-distorting equipment used within driver education programs to simulate alcohol-related impairment. However, there is no empirical evidence comparing the behavioral effects associated with wearing FVGs to alcohol intoxication. The purpose of this study was to determine the validity of FVGs in producing alcohol-related impairment in simulated driving.

Methods: Twenty-two healthy males (age: 23 ± 3 years, mean ± SD) participated in a placebo-controlled crossover design study involving 4 experimental trials. In each trial, participants completed a baseline level simulated driving task followed by an experimental driving task, involving one of 4 treatments: (1) a dose of alcohol designed to elicit 0.080% breath alcohol concentration (BrAC; AB), (2) an alcohol placebo beverage (PB), (3) FVG (estimated % blood alcohol concentration [BAC] 0.070–0.100+), and (4) placebo goggles (PGs). The driving tasks included 3 separate scenarios lasting ～5 min each; these were a simple driving scenario, a complex driving scenario, and a hazard perception driving scenario. Selected lateral control parameters (standard deviation of lane position [SDLP]; total number of lane crossings [LCs]) and longitudinal control parameters (average speed; standard deviation of speed [SDSP]; distance headway; minimum distance headway) were monitored during the simple and complex driving scenarios. Latency to 2 different stimuli (choice reaction time [CRT]) was tested in the hazard perception driving scenario. Subjective ratings of mood and attitudes toward driving were also provided during each of the trials.

Results: Neither placebo treatment influenced simulated driving performance. Mean BrAC was 0.060 ± 0.010% at the time of driving on the AB trial. Lateral control: In the simple driving scenario, SDLP and LC were not affected under any of the experimental treatments. However, in the complex driving scenario, significantly greater SDLP was observed on both the FVG and AB trials compared to their respective baseline drives. LC increased significantly from baseline on the AB trial only. Longitudinal control: Speed was not affected by any of the experimental treatments; however, SDSP increased significantly from baseline on the FVG trial. A significant reduction in distance headway and minimum distance headway was detected on the FVG trial compared to baseline. Hazard perception: Neither AB nor FVG trials were influential on CRT. Subjective mood ratings were significantly altered on the AB and FVG trials compared to baseline and placebo conditions. Participants reported reduced willingness and ability to drive under the active treatments (AB and FVG) than the placebo treatments (PB and PG).

Conclusions: FVGs may have some utility in replicating alcohol-related impairment on specific driving performance measurements. Hence, the equipment may offer an alternative approach to researching the impact of alcohol intoxication on simulated driving performance among populations where the provision of alcohol would otherwise be unethical (e.g., prelicensed drivers).     

Transport company safety climate—The impact on truck driver behavior and crash involvement

Objective: The present study investigated the relationships between safety climate and driving behavior and crash involvement.

Methods: A total of 339 company-employed truck drivers completed a questionnaire that measured their perceptions of safety climate, crash record, speed choice, and aberrant driving behaviors (errors, lapses, and violations).

Results: Although there was no direct relationship between the drivers' perceptions of safety climate and crash involvement, safety climate was a significant predictor of engagement in risky driving behaviors, which were in turn predictive of crash involvement.

Conclusions: This research shows that safety climate may offer an important starting point for interventions aimed at reducing risky driving behavior and thus fewer vehicle collisions.     

Sensitivity evaluation of the visual,tactile, and auditory detection response task method while driving

Objectives: In this article, we evaluate the sensitivity to cognitive load of 3 versions of the Detection Response Task method (DRT), proposed in ISO Draft Standard DIS-17488.

Methods: We present a user study with 30 participants in which we compared the sensitivity to cognitive load of visual, audio, and tactile DRT in a simulated driving environment. The amount of cognitive load was manipulated with secondary n-back tasks at 2 levels of difficulty (0-back and 1-back). We also explored whether the DRT method is least sensitive to cognitive load when the stimuli and secondary task are of the same modality. For this purpose, we used 3 forms to present the n-back task stimuli: visual, audio, and tactile. Responses to the task were always vocal. The experiment was based on a between-subject design (the DRT modalities) with 2 levels of within-subject design study (modalities and difficulty of the secondary n-back tasks). The participants' primary task in the study was to drive safely, and a second priority was to answer to DRT stimuli and perform secondary tasks.

Results: The results indicate that all 3 versions of the DRT tested were sensitive to detecting the difference in cognitive load between the reference driving period and driving and engaging in the secondary tasks. Only the visual DRT discriminated between the 0-back and 1-back conditions on mean response time. Contrary to expectations, no interaction was observed between DRT modality and the stimuli modality used for presentation of the secondary tasks.

Conclusions: None of the 3 methods of presenting DRT stimuli showed a consistent advantage in sensitivity in differentiating multiple levels of cognitive load if all response times, hit rates, and secondary task performance are considered. If only response time is considered, the visual presentation of the DRT stimulus used in this study showed some advantages. In interpreting these data, it should be noted that the methods of DRT stimulus presentation varied somewhat from the currently proposed draft ISO standard and it is possible that the relative salience level of the visual DRT stimulus influenced the findings. It is further suggested that more than 2 levels of difficulty of the n-back task should be considered for further investigation of the relative sensitivity of different DRT stimuli modalities. Parameters that indicate change in cognitive load (response time, hit rate, task performance) should be analyzed together in assessing the overall impact on the driver and not individually, in order to obtain a fuller insight of the assessed cognitive load.     

Representativity and univocity of traffic signs and their effect on trajectory movement in a driving simulation task: Warning signs

Objective: The effect of traffic signs on the behavior of drivers is not completely understood. Knowing about how humans process the meaning of signs (not just by learning but instinctively) will improve reaction time and decision making when traveling. The economic, social, and psychological consequences of car accidents are well known.

Methods: This study sounds out which traffic signs are more ergonomic for participants, from a cognitive point of view, and determines, at the same time, their effect in participants' movement trajectories in a driving simulation task.

Results: Results point out that the signs least representative of their meaning produce a greater deviation from the center of the road than the most representative ones.

Conclusions: This study encourages both an in-depth analysis of the effect on movement of roadside signs and the study of how this effect can be modified by the context in which these signs are presented (with the aim to move the research closer to and analyze the data in real contexts). The goal is to achieve clarity of meaning and lack of counterproductive effects on the trajectory of representative signs (those that provoke fewer mistakes in the decision task).     

Are you okay to drive? Commuting behavior and blood alcohol concentrations among restaurant diners

Objective: Drink driving is widely recognized as a major road safety problem. In Australia, health promotion messages encourage monitoring the number of standard drinks consumed prior to driving. This pilot research aimed to investigate commuting behavior and blood alcohol concentration (BAC) of diners, including intended drivers, at Sunshine Coast restaurants.

Methods: Five hundred and forty-four diners (n = 260 males) consented to participate in a brief interview and to use a breathalyzer device to measure their BAC.

Results: Forty percent of participants advised they don't drink and drive (34% of males, 45% of females; 67.25% of <17–20 years, 30.5% of 50–59 years), and of the remaining participants, 75% advised they count the number of their drinks (69% of males, 84% of females; 32% of <17–20 years, 82% of 50–59 years), while 10% of participants monitored their BAC by how they were feeling (12% of males, 6% of females). Thirty-seven percent of participants said it was easy/very easy to estimate their BAC (41% of males; 33% of females; 21% of <17–20 years, 43% of 50–59 years). The actual BAC was less than expected for 56% of participants, with one-third underestimating BAC and some intended drivers having an actual BAC in excess of the 0.05 limit.

Conclusions: Given the proportion of diners who reported they count the number of drinks, or use feelings as a way to gauge BAC, coupled with the considerable proportion who underestimated their BAC, a safer public health message is to avoid driving if you intend to drink. In addition, targeted intervention for experienced drivers (and, arguably, drinkers) appears warranted, as every participant aged less than 21 years who stated he or she would drive home indeed had a zero BAC. Interestingly every female driver who stated she would be driving home also had a legal BAC, suggesting gender-specific intervention.