Ship ballast water as a main vector of marine introductions in the Mediterranean Sea

Marine invasive species are currently recognized as one of the most significant threats to global biodiversity. Marine bioinvasions are more likely in the Mediterranean Sea because of its wide temperature range, degraded habitats, historical and high volume of shipping traffic, and high occurrence of aquaculture. One of the main vectors of marine introductions globally and Mediterranean-wide is commercial shipping. Of the 3,000–4,000 species transferred around the world via commercial vessels, approximately 30% of these species may have been redistributed in the Mediterranean. Ships and marine invasive species arriving in the Mediterranean are mainly from temperate to cold-water regions. Standardized research and management approaches between countries are required to address the threat of ballast water borne marine invasives on a global scale. Regionally, a Mediterranean program involving the different states is currently needed to develop a common line of research and management operations.     

Number and phylogenetic affiliation of bacteria assimilating dimethylsulfoniopropionate and leucine in the ice-covered coastal Arctic Ocean

The ability of bacteria to assimilate sulfur from dimethylsulfoniopropionate (DMSP) was examined in the western Arctic Ocean by combining microautoradiography and fluorescence in situ hybridization (FISH). Assimilation of leucine was also measured for comparative purposes since leucine is considered a universal substrate for bacteria, which use it for protein synthesis. Samples were collected at 3 m depth, through a hole in the ice, in the CASES (Canadian Arctic Shelf Ecosystem Study) overwintering station in Franklin Bay (eastern Beaufort Sea) in March and May 2004 to compare two contrasting situations: winter and early spring. FISH counts indicated that the bacterial assemblage consisted of α- (up to 60% of the EUB positive cells), β- (up to 10%) and γ-proteobacteria (around 20%), and Bacteroidetes (up to 60%). The β-proteobacteria were not active with any of the two substrates tested. The remaining groups were much less efficient at assimilating DMSP-sulfur (5% of the cells) than leucine (20–35%) both in winter and in spring. Only the Roseobacter group of α-proteobacteria showed a similar assimilation of both substrates.     

煤的气化——清洁选择 煤合成气——天然气的竞争者，清洁、廉价的电厂燃料

作为燃料有几个优势，其中包括储量充足和价格低廉。但是没有“清洁煤”这种说法。除了煤烟、有毒化学品，以及金属外，燃煤电厂每千瓦小时放出的二氧化碳也比燃烧石油或天然气的电厂要多。煤在空气中燃烧时不可避免地产生二氧化碳。因此煤是一种问题燃料，不仅在于它引发气候变化，而且影响到人类健康和安全问题。     

Inter-temporal variation in the travel time and travel cost parameters of transport models

The parameters for travel time and travel cost are central in travel demand forecasting models. Since valuation of infrastructure investments requires prediction of travel demand for future evaluation years, inter-temporal variation of the travel time and travel cost parameters is a key issue in forecasting. Using two identical stated choice experiments conducted among Swedish drivers with an interval of 13 years, 1994 and 2007, this paper estimates the inter-temporal variation in travel time and cost parameters (under the assumption that the variance of the error components of the indirect utility function is equal across the two datasets). It is found that the travel time parameter has remained constant over time but that the travel cost parameter has declined in real terms. The trend decline in the cost parameter can be entirely explained by higher average income level in the 2007 sample compared to the 1994 sample. The results support the recommendation to keep the travel time parameter constant over time in forecast models, but to deflate the travel cost parameter with the forecasted income increase among travellers and the relevant income elasticity of the cost parameter. Evidence from this study further suggests that the inter-temporal and the cross-sectional income elasticities of the cost parameter are equal. The average elasticity is found to be ?0.8 to ?0.9 in the present sample of drivers, and the elasticity is found to increase with the real income level, both in the cross-section and over time.     

在不同水质地区实地进行海洋生物膜对SS UNS S32760不锈钢腐蚀行为研究（英文）

In the presence of biofilms, stainless steels(SS) exhibits an increase in corrosion potential, called ennoblement. In the present study, the corrosion potential(Ecorr) behavior of the duplex SS UNS S32760 was recorded simultaneously with the in situ marine biofilm formation in two areas at Arraial do Cabo,Southeastern Brazil. The biofilm at Forno Harbor(an anthropogenically disturbed area) was characterized by higher relative abundances of Bacteria at day 2, followed by diatoms(especially Navicula sp.) on day 10 and dinoflagellates on day 18,whereas no clear trend was recorded at Cabo Frio Island(an undisturbed area). The ennoblement of Ecorr values was site-dependent. In a complementary laboratory assay, biofilms were removed and the Ecorr values registered in sterile conditions for the subsequent 10 days and corroborated in situ results. Understanding biofilms and SS interactions has important implications for materials science and engineering decisions as well as helping to fill in important gaps in this knowledge.     

斯德哥尔摩的拥挤收费政策——政策实施5年后的效果、接受度及经验启示

根据2006年拥挤收费政策试运行结束后的公民投票结果,2007年,斯德哥尔摩正式实施了该政策。讨论了其至2011年6月首个5年内的政策实施效果。结果表明,受到外部因素影响,由收费引起的交通减少量随时间推移稍有增加。2008年的清洁汽车免税措施可显著提高销售量。结合最新研究成果和瑞典的经验,讨论了公众接受度和政治接受度。得到的结论是：拥挤收费对交通系统的主客观影响,以及环境和政治态度,是公众支持拥挤收费的基础;同时,为了获得政治支持,必须要进行体制改革、解决权力问题。最后,简要讨论了拥挤收费的实施对瑞典交通规划进程的可能影响。     

Economic efficiency in Spanish ports: some empirical evidence

In this study, a stochastic frontier cost function is used to estimate the econmic efficiency of Spanish ports through panel data. The sample covers annual data of 27 Spanish ports from 1985-1989. By comparing a Cobb-Douglas function with a translog, it is found that the latter best represents the technology according to the data. Analysing the efficiency indices obtained, it is found that the relatively larger ports are more economically inefficient. Moreover, the presence of large scale economies has been detected, as well as a lack of technical progress for the period considered.     

The value of time and external benefits in bicycle appraisal

We estimate the value of time savings, different cycling environments and additional benefits in cost-benefit analysis of cycling investments. Cyclists’ value of travel time savings turns out to be high, considerably higher than the value of time savings on alternative modes. Cyclists also value other improvements highly, such as separated bicycle lanes. As to additional benefits of cycling improvements in the form of health and reduced car traffic, our results do not support the notion that these will be a significant part in a cost-benefit analysis. Bicyclists seem to take health largely into account when making their travel choices, implying that it would be double-counting to add total health benefits to the analysis once the consumer surplus has been correctly calculated. As to reductions in car traffic, our results indicate that the cross-elasticity between car and cycle is low, and hence benefits from traffic reductions will be small. However, the valuations of improved cycling speeds and comfort are so high that it seems likely that improvements for cyclists are cost-effective compared to many other types of investments, without having to invoke second-order, indirect effects. In other words, our results suggest that bicycle should be viewed as a competitive mode of travel and not primarily as a means to achieve improved health or reduced car traffic.     

基于软计算的低于数据范围的半圆形防波堤波浪反射预报（英文）

Coastal defenses such as the breakwaters are important structures to maintain the navigation conditions in a harbor. The estimation of their hydrodynamic characteristics is conventionally done using physical models, subjecting to higher costs and prolonged procedures. Soft computing methods prove to be useful tools, in cases where the data availability from physical models is limited. The present paper employs adaptive neuro-fuzzy inference system(ANFIS) and artificial neural network(ANN) models to the data obtained from physical model studies to develop a novel methodology to predict the reflection coefficient(K_r) of seaside perforated semicircular breakwaters under low wave heights, for which no physical model data is available. The prediction was done using the input parameters viz., incident wave height(Hi), wave period(T), center-to-center spacing of perforations(S), diameter of perforations(D), radius of semicircular caisson(R), water depth(d), and semicircular breakwater structure height(h_s). The study shows the prediction below the available data range of wave heights is possible by ANFIS and ANN models. However, the ANFIS performed better with R~2= 0.9775 and the error reduced in comparison with the ANN model with R~2= 0.9751. Study includes conventional data segregation and prediction using ANN and ANFIS.     

The potential of mobility as a service bundles as a mobility management tool

Transportation - The Mobility as a Service (MaaS) concept has recently taken the transport industry by storm. However, as applications and research on it are limited, there is still little evidence...