Processus advectifs et répartition du zooplancton dans un fjord

In order to study the influence of advective processes on the zooplankton distribution in a shallow sill-fjord, we examined the temporal variations (tidal and seasonal) of currents, density, abundance and composition of zooplankton in the Saguenay fjord, Québec, Canada, in August 1978 and October 1979. Our results demonstrate the existence of a regular exchange of water (every tidal cycle) between the St. Lawrence estuary and the two outer basins of the Saguenay fjord which is characterized by an important transport of mesoplankton from the estuary into the deep waters of the Saguenay during the rising tide and from the surface waters of the Saguenay to those of the estuary during falling tide. Variations of abundance and composition of zooplankton in the outer basin are therefore mainly controlled by advective processes. The plankton community of the downstream region of the fjord is strongly influenced by variations of abundance and composition taking place in the estuary, and the establishment and development of local populations of zooplankton are made difficult. In the upstream region of the fjord, the advective processes are less intense and endogeneous mesoplankton populations thrive under local temperature conditions.     

Studies on the biology of young grey mullet (Mugil cephalus) digestion

The effect of body size and salinity on the rate of digestion of young grey mullet, Mugil cephalus L., was studied using the sacrifice method. The rate of digestion was found to be salinity-dependent, being slower at lower salinities than at higher salinities. This is correlated to higher food intake at the lower salinities. Rate of digestion was also found to be dependent on body size, increasing with increasing body weight.     

Fe—C微电解法＋H2O2组合工艺处理对氯硝基苯废水

利用废铁屑对对氯硝基苯废水进行预处理 ,可以使废水中的对氯硝基苯转化为氨基氯苯 ,然后在废水中加入H2 O2 ,使H2 O2 与废水中的Fe2 + 构成Fenton试剂 ,反应生产OH·自由基 ,OH·自由基具有强烈的氧化性 ,将氨基氯苯和对氯硝基苯中的苯环打开 ,形成断链 ,再进一步将其矿化分解     

Integrated, sustainable touristic development of the karstic coastline of SW Sardinia

In the coastal karstic region of SW Sardinia, from Capo Pecora in the north to Nebida in the south, many interesting geological monuments, ecotopes and several places of social and cultural interest that deserve preservation and valorization can be found. This mostly rocky coastline is characterized by the presence of a Cambrian sequence prevalently composed of limestones and dolostones and only locally of phyllites. A correct use of the many environmental and cultural monuments is necessary both to preserve and to valorize them; therefore they have to be properly managed in order to preserve their original natural conditions. Here, we describe and classify these monuments with the aim to propose an integrated model of sustainable development of this exceptional coastal landscape. Our model is based on several thematic maps according to which we propose the establishment of a natural reserve with specific geological and geomorphologic sites and the creation of several touristic circuits that are the basis for a further valorization of this territory.     

Optimizing two- and three-stage designs for spatial inventories of natural resources by simulated annealing

This paper reviews design-based estimators for two- and three-stage sampling designs to estimate the mean of finite populations. This theory is then extended to spatial populations with continuous, infinite populations of sampling units at the latter stages. We then assume that the spatial pattern is the result of a spatial stochastic process, so the sampling variance of the estimators can be predicted from the variogram. A realistic cost function is then developed, based on several factors including laboratory analysis, time of fieldwork, and numbers of samples. Simulated annealing is used to find designs with minimum sampling variance for a fixed budget. The theory is illustrated with a real-world problem dealing with the volume of contaminated bed sediments in a network of watercourses. Primary sampling units are watercourses, secondary units are transects perpendicular to the axis of the watercourse, and tertiary units are points. Optimal designs had one point per transect, from one to three transects per watercourse, and the number of watercourses varied depending on the budget. However, if laboratory costs are reduced by grouping all samples within a watercourse into one composite sample, it appeared to be efficient to sample more transects within a watercourse.     

Foliar concentrations of volunteer willows growing on polluted sediment-derived sites versus sites with baseline contamination levels

Many alluvial soils along navigable waterways are affected by disposal of dredged sediments or overbank sedimentation and contain metal concentrations that are elevated compared to baseline levels. Uptake patterns for metals and other elements by several volunteer Salix species growing on these sites were determined during a growing season in field plots and compared with the same species growing on soils with baseline contamination levels. For Cd and Zn, foliar concentrations were clearly higher on dredged sediment landfills. Uptake patterns differed significantly between species. A high uptake of Mn and low uptake of Cu, K and S in S. cinerea was attributed to wetland soil chemistry. Site effects on metal uptake were evaluated in more detail for Salix cinerea and S. alba growing on different sediment-derived sites under field conditions. Foliar Cd concentrations were higher in S. cinerea than in S. alba. This appeared to be a genetic feature not influenced by soil chemical properties, as it was observed both on clean sites and polluted sediment-derived sites. For S. cinerea, soil chemistry was reflected in foliar concentrations, while foliar Cd concentrations and bioavailability were found to be independent of the thickness of the polluted horizon. Dredged sediment landfills and freshwater tidal marshes with comparable Cd soil pollution had significantly different foliar Cd concentrations.     

Decline of sacred fir (Abies religiosa) in a forest park south of Mexico City

Decline of sacred fir (Abies religiosa) trees in the high elevation forest park, Desierto de los Leones, located south of Mexico City, is described. Trees located in the windward zone (exposed to air masses from Mexico City) were the most severely affected, especially trees at the distal ends of ravines. Examination of tree growth rings indicated decreases in ring widths for the past 30 years. Polluted air from Mexico City may be an important causal factor in fir decline. Drought, due to excessive removal of soil water, insects, mites and pathogens, and poor forest management are possible contributing and interactive factors in fir decline.     

Mobile phone use while riding a motorcycle and crashes among university students

Objective: Motorcycle crashes are a significant road safety challenge, particularly in many low- and middle-income countries where motorcycles represent the vast majority of their vehicle fleet. Though risky riding behaviors, such as speeding and riding under the influence of alcohol, have been identified as important contributors to motorcycle crashes, little is understood about the effect of using a mobile phone while riding on motorcycle crash involvement. This article investigates crash involvement among motorcycle riders with risky riding behaviors, particularly using a mobile phone while riding.

Methods: Data were obtained from an online survey of university students’ risky riding behaviors in Vietnam administered between March and May 2016 (n?=?665).

Results: Results show that 40% of motorcycle riders reported to have experienced a crash/fall and nearly 24% of motorcycle riders indicated that they had been injured in a crash/fall. Effects of mobile phone use while riding on safety of motorcycle riders are highlighted. Specifically, more frequent use of a mobile phone for texting or searching for information while riding is associated with a higher chance of being involved in a crash/fall. The results also show that drink riding is associated with a higher chance of being injured.

Conclusions: Overall this article reveals significant safety issues of using a mobile phone while riding a motorcycle, providing valuable insight for designing education and publicity campaigns.     

贴面工艺对合成板材燃烧性能的影响

天然木材资源短缺,导致近年来合成板材使用量大大增加,为了了解不同贴面工艺对合成板材燃烧性能的影响。基于锥形量热仪法评定3种经过表面处理的合成板材（胶合板、中密度纤维板、刨花板）,探究表面处理技术对合成板材燃烧性能的影响。研究结果表明:贴薄木片与贴浸渍纸技术明显降低了胶合板的火灾危险性;贴薄木片技术明显降低了中密度板的火灾危险性;贴浸渍纸增加了刨花板与中密度板的火灾危险性。     

Environmental research in the environmental policy cycle

A recent article in this journal put forward an environmental research policy, organized around the environmental policy cycle The research policy concerned is flawed by a bias generally occurring in the philosophy of science, i e., the inability to include the normative science disciplines in the science and research concepts. This inability results in a biased environmental research effort. Almost all attention goes to physical science research in the problem-identification phase of the environmental policy cycle. Practice shows that it is wise to be more open-minded It may be more efficient to employ normative science research, directly productive for solving environmental problems, than to be able to identify these problems better and better This article describes and underpins a more comprehensive approach to environmental research and exemplifies typical research questions.