1998年厄尔尼诺后珊瑚礁的侵蚀与恢复:印度洋查戈斯礁群

在印度洋中部查戈斯礁群的大多数珊瑚死亡之后3年,对30m水深以浅珊瑚的侵蚀和恢复情况进行了研究.北部环礁15m水深以浅、中部和南部环礁＞35m处的珊瑚差不多全部死亡.由于密集珊瑚丛的损失,一些礁体"表面"下降了1 5m.珊瑚的生物侵蚀情况严重,减少了三维礁体"结构"并形成松散的碎石.幼年珊瑚数量众多,尽管大部分是在侵蚀的或不稳定的基底上,并且稳定种较少.在15m的深度,礁体间鱼类丰度和多样性仍旧较高;依赖于珊瑚生存的物种减少,而一些食草动物和食碎屑动物则增加.一个新的海面温度(SST)数据集表明,平均SST自1950年以来升高了0.65℃.造成查戈斯珊瑚礁死亡的临界SST是29.9℃.     

Sleepiness among night-time drivers: relationship to blood alcohol concentration and other factors

OBJECTIVE: The study aimed to explore the distribution and correlates of subjective sleepiness among the general night-time driving population. METHODS: The survey took place in three British Columbia communities in June 2003 between 21:00 hours to 03:00 hours. Sites and vehicles were selected randomly. Surveyors obtained information on several demographic and situational variables including self-assessed degree of sleepiness and self-reported hours asleep and awake, as well as an objective measure of blood alcohol concentration obtained from a hand-held breath-testing device. RESULTS: The total compliance rate among intercepted drivers was 85%. Among the 2335 drivers responding to the questionnaire, 68.4% indicated that they were wide awake, 27.6% were somewhat sleepy, and 4.1% were very sleepy. Logistic regression quantified the independent contributions of the various factors to subjective sleepiness. Male drivers with positive blood alcohol concentrations under 50 mg% were more likely to report feeling sleepy than those with either higher or with zero blood alcohol concentration. Greater relative risk of sleepiness was also associated with being female, being under age 55, and advanced hour of night. Driving with passengers of the same gender was associated with lower reported sleepiness. CONCLUSIONS: A substantial proportion of night-time drivers are driving while sleepy, especially at late night and early morning hours. The combination of alcohol and sleepiness compounds impairment in experimental studies and deserves greater attention in crash risk studies and as a topic for public education and awareness.     

Development and implementation of eco-genomic tools for aquatic ecosystem biomonitoring: the SYNAQUA French-Swiss program

The effectiveness of environmental protection measures is based on the early identification and diagnosis of anthropogenic pressures. Similarly, restoration actions require precise monitoring of changes in the ecological quality of ecosystems, in order to highlight their effectiveness. Monitoring the ecological quality relies on bioindicators, which are organisms revealing the pressures exerted on the environment through the composition of their communities. Their implementation, based on the morphological identification of species, is expensive because it requires time and experts in taxonomy. Recent genomic tools should provide access to reliable and high-throughput environmental monitoring by directly inferring the composition of bioindicators’ communities from their DNA (metabarcoding). The French-Swiss program SYNAQUA (INTERREG France-Switzerland 2017–2019) proposes to use and validate the tools of environmental genomic for biomonitoring and aims ultimately at their implementation in the regulatory bio-surveillance. SYNAQUA will test the metabarcoding approach focusing on two bioindicators, diatoms, and aquatic oligochaetes, which are used in freshwater biomonitoring in France and Switzerland. To go towards the renewal of current biomonitoring practices, SYNAQUA will (1) bring together different actors: scientists, environmental managers, consulting firms, and biotechnological companies, (2) apply this approach on a large scale to demonstrate its relevance, (3) propose robust and reliable tools, and (4) raise public awareness and train the various actors likely to use these new tools. Biomonitoring approaches based on such environmental genomic tools should address the European need for reliable, higher-throughput monitoring to improve the protection of aquatic environments under multiple pressures, guide their restoration, and follow their evolution.     

Molecular tools for bathing water assessment in Europe: Balancing social science research with a rapidly developing environmental science evidence-base

The use of molecular tools, principally qPCR, versus traditional culture-based methods for quantifying microbial parameters (e.g., Fecal Indicator Organisms) in bathing waters generates considerable ongoing debate at the science–policy interface. Advances in science have allowed the development and application of molecular biological methods for rapid (~2 h) quantification of microbial pollution in bathing and recreational waters. In contrast, culture-based methods can take between 18 and 96 h for sample processing. Thus, molecular tools offer an opportunity to provide a more meaningful statement of microbial risk to water-users by providing near-real-time information enabling potentially more informed decision-making with regard to water-based activities. However, complementary studies concerning the potential costs and benefits of adopting rapid methods as a regulatory tool are in short supply. We report on findings from an international Working Group that examined the breadth of social impacts, challenges, and research opportunities associated with the application of molecular tools to bathing water regulations.     

The Effect of Fuel Composition on Atmospheric Aerosol Due to Auto Exhaust

Aerosols attributable to automobile exhaust can be classified as two types—primary aerosol (initially present in the exhaust) and secondary aerosol (generated photochemically from hydrocarbons and nitrogen oxides in the exhaust). In this study, investigation was made of possible effects of motor-fuel composition on the formation of these aerosols. Secondary aerosol, of principal interest in this work, was produced by irradiating auto exhaust in Battelle-Columbus’ 610 ft³ environmental chamber. A limited number of determinations of primary aerosol in diluted auto exhaust was made at the exit of a 36 ft dilution runnel. Determination of both primary and secondary aerosol was based on light-scattering measurements.

Exhaust was generated with seven full-boiling motor gasolines, both leaded and nonleaded, in a 1967 Chevrolet which was not equipped with exhaust-emission control devices. Changes in fuel composition produced a maximum factor of three difference in light scattering due to primary aerosol. Aerosol yields, for consecutive driving cycles on the same fuel, vary considerably; as a result, ranking the fuels on the basis of average primary aerosol yield was not very meaningful. In addition to fuel composition, the more important independent variables are initial SO₂ concentration, relative humidity and initial hydrocarbon concentration. Statistical analysis of the data indicates that the seven test fuels can be divided into two arbitrary groups with regard to secondary aerosol-forming potential. The fuels in the lower light-scattering group had aromatic contents of 15 and 21%, while those in the higher light-scattering group had aromatic contents of 25, 48, and 55%. Although the fuels can be grouped on the basis of a compositional factor, the grouping of fuels with aromatic content ranging from 25 to 55% indicates that this compositional factor cannot be equated simply with aromatic content. In an associated study of the aerosol-forming potential of individual hydrocarbons prominent in auto exhaust, it was observed that aromatics produce substantially more photochemical aerosol than olefins and paraffins. However, experiments with binar/hydrocarbon mixtures containing aromatjcs, as well as in these exhaust experiments, a strong dependence of aerosol yield on the aromatic components is is not observed. Thus, the data indicate that the dependence of secondary aerosol formation on fuel factors is a complex one and cannot be predicted solely on the basis of a sirigle hydrocarbon component reactivity scale.

The two types of automobile aerosol did not have the same dependence on fuel, composition. The variation in total light scattering attributable to primary plus secondary aerosol was less than that due to either component alone. It therefore was concluded that the light scattering due to automobile exhaust emissions in these experiments was not significantly affected by changing fuel composition.     

Investigation of Child Restraint System (CRS) Compatibility in the Vehicle Seat Environment

Objective: Child restraint system (CRS) misuse is common and can have serious consequences to child safety. Physical incompatibilities between CRS and vehicles can complicate the installation process and may worsen CRS misuse rates. This study aims to identify the most common sources of incompatibility between representative groups of CRS and vehicles.

Methods: Detailed dimensional data were collected from 59 currently marketed CRS and 61 late model vehicles. Key dimensions were compared across all 3,599 theoretical CRS/vehicle combinations and the most common predicted incompatibilities were determined. A subset of 34 physical installations was analyzed to validate the results.

Results: Only 58.2% of rear-facing (RF) CRS/vehicle combinations were predicted to have proper agreement between the vehicle's seat pan angle and the CRS manufacturers’ required base angle. The width of the base of the CRS was predicted to fit snugly between the vehicle's seat pan bolsters in 63.3% of RF CRS/vehicle combinations and 62.2% of forward-facing (FF) CRS/vehicle combinations. FF CRS were predicted to be free of interaction with the vehicle's head restraint in 66.4% of combinations. Roughly 90.0% of RF CRS/vehicle combinations were predicted to have enough horizontal clearance space to set the front seat in the middle its fore/aft slider track. Compatibility rates were above 98% regarding the length of the CRS base compared to the length of the vehicle seat pan and the ability of the top tether to reach the tether anchor. Validation studies revealed that the predictions of RF CRS base angle range vs. seat pan angle compatibility were accurate within 6%, and head restraint interference and front row clearance incompatibilities may be more common than the dimensional analysis approach has predicted.

Conclusions: The results of this study indicate that RF CRS base angles and front row clearance space, as well as FF CRS head restraint interference, are frequent compatibility concerns. These results enable manufacturers, researchers, and consumers to focus their attention on the most relevant CRS/vehicle incompatibility issues in today's market.     

Detection and Phylogenetic Analysis of the Hepatitis E Virus in a Canadian Swine Production Network

Viral contamination along the production chain is a significant concern in both food safety and livestock health. Pigs have been reported to act as a reservoir for zoonotic viruses, sometimes emerging ones, and epidemiological studies have shown direct links between the consumption of uncooked pork offal and cases of hepatitis caused by the hepatitis E virus (HEV) genotype 3 in humans. The presence of HEV in swine herds has been reported, but its dissemination in pork production environments is still unknown. To investigate viral contamination sources in the swine industry, 452 environment and fecal samples, including samples from livestock transportation vehicles, were collected over a period of 11 months from ten farms and one slaughterhouse that together represent a single production network. Hepatitis E virus RNA was detected by nested RT-PCR in 32 samples from both inside and outside farm buildings, on trucks, and, mostly, from fomites collected in the slaughterhouse yard, such as on a utility vehicle. Phylogenetic analysis showed a wide diversity of HEV genotype 3 strains, similar to human and swine strains previously found. According to the results of this study, the movements of trucks and utility vehicles might play an important role in HEV dissemination on a slaughterhouse site and throughout an entire network.     

Review of LCA studies of solid waste management systems – Part II: Methodological guidance for a better practice

Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of the provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs.