Evaluation of ecological network analysis: Validation of output

Ecological network analysis (ENA) is a modeling approach increasingly being used to evaluate food webs and provide an ecosystem-based approach to resource management. Unfortunately, validation of ENA output is rarely performed. This study represents part of a larger effort to critically evaluate ENA. Here we validate ENA output using stable isotope analysis (SIA), and where validation is not met, determine the effects of modifying trophic networks to reflect validation.     

Applications of biosensors for bacteria and virus detection in food and water–A systematic review

Biosensors for sensitive and specific detection of foodborne and waterborne pathogens are particularly valued for their portability, usability, relatively low cost, and real-time or near real-time response. Their application is widespread in several domains, including environmental monitoring. The main limitation of currently developed biosensors is a lack of sensitivity and specificity in complex matrices. Due to increased interest in biosensor development, we conducted a systematic review, com...     

密封包装容器微环境温湿度模型的建立与仿真

目的建立温湿度模型和仿真软件,对贮存环境下一段时间内包装容器微环境温湿度进行预计,为提前预测容器内产品的性能变化情况提供技术支撑。方法分析微环境温湿度与密封包装材料、环境的关系,建立温湿度模型,用有限元方法进行仿真,并用实测数据对仿真模型进行对比和验证。结果与试验实测结果相比较,温度仿真结果的最大相对误差不超过8%,湿度仿真结果的最大相对误差不超过11%。结论微环境温湿度仿真软件能对贮存时间较长、不同规格的包装容器微环境温湿度进行准确预计,具有良好的应用前景。     

Response of balanced network models to large-scale perturbation: Implications for evaluating the role of small pelagics in the Gulf of Maine

Exploring the response of an ecosystem, and subsequent tradeoffs among its biological community, to human perturbations remains a key challenge for the implementation of an ecosystem approaches to fisheries (EAF). To address this and related issues, we developed two network (or energy budget) models, Ecopath and Econetwrk, for the Gulf of Maine ecosystem. These models included 31 network “nodes” or biomass state variables across a broad range of trophic levels, with the present emphasis to particularly elucidate the role of small pelagics. After initial network balancing, various perturbation scenarios were evaluated to explore how potential changes to different fish, fisheries and lower trophic levels can affect model outputs. Categorically across all scenarios and interpretations thereof, there was minimal change at the second trophic levels and most of the “rebalancing” after a perturbation occurred via alteration of the diet matrix. Yet the model results from perturbations to a balanced energy budget fall into one of three categories. First, some model results were intuitive and in obvious agreement with established ecological and fishing theory. Second, some model results were counter-intuitive upon initial observation, seemingly contradictory to known ecological and fishing theory; but upon further examination the results were explainable given the constraints of an equilibrium energy budget. Finally, some results were counter-intuitive and difficult to reconcile with theory or further examination of equilibrium constraints. A detailed accounting of biomass flows for example scenarios explores some of the non-intuitive results more rigorously. Collectively these results imply a need to carefully track biomass flows and results of any given perturbation and to critically evaluate the conditions under which a new equilibrium is obtained for these types of models, which has implications for dynamic simulations based off of them. Given these caveats, the role of small pelagics as a prominent component of this ecosystem remains a robust conclusion. We discuss how one might use this approach in the context of further developing an EAF, recognizing that a more holistic, integrated perspective will be required as we continue to evaluate tradeoffs among marine biological communities.     

Monitoring of environmental exposure to polycyclic aromatic hydrocarbons: a review

Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds with two or more fused aromatic rings. They have a relatively low solubility in water, but are highly lipophilic. Most of the PAHs with low vapour pressure in the air are adsorbed on particles. When dissolved in water or adsorbed on particulate matter, PAHs can undergo photodecomposition when exposed to ultraviolet light from solar radiation. In the atmosphere, PAHs can react with pollutants such as ozone, nitrogen oxides and sulfur dioxide, yielding diones, nitro- and dinitro-PAHs, and sulfonic acids, respectively. PAHs may also be degraded by some microorganisms in the soil. PAHs are widespread environmental contaminants resulting from incomplete combustion of organic materials. The occurrence is largely a result of anthropogenic emissions such as fossil fuel-burning, motor vehicle, waste incinerator, oil refining, coke and asphalt production, and aluminum production, etc. PAHs have received increased attention in recent years in air pollution studies because some of these compounds are highly carcinogenic or mutagenic. Eight PAHs (Car-PAHs) typically considered as possible carcinogens are: benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene (B(a)P), dibenzo(a,h)anthracene, indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene. In particular, benzo(a)pyrene has been identified as being highly carcinogenic. The US Environmental Protection Agency (EPA) has promulgated 16 unsubstituted PAHs (EPA-PAH) as priority pollutants. Thus, exposure assessments of PAHs in the developing world are important. The scope of this review will be to give an overview of PAH concentrations in various environmental samples and to discuss the advantages and limitations of applying these parameters in the assessment of environmental risks in ecosystems and human health. As it well known, there is an increasing trend to use the behavior of pollutants (i.e. bioaccumulation) as well as pollution-induced biological and biochemical effects on human organisms to evaluate or predict the impact of chemicals on ecosystems. Emphasis in this review will, therefore, be placed on the use of bioaccumulation and biomarker responses in air, soil, water and food, as monitoring tools for the assessment of the risks and hazards of PAH concentrations for the ecosystem, as well as on its limitations.     

The Spanish toxic oil syndrome: Some explanations for the pathology and an appraisal of the similarities with other episodes of food adulteration

In 1981 in Madrid, a new disease was identified, and attributed to the fraudulent sale of adulterated, industrial-quality oil as olive oil. The competing hypotheses for the clinical symptoms and tissue changes are reviewed but it is also important to note the general similarities between this epidemic and those other incidents where food adulteration has presented an acute hazard.     

Diversity of hydric soils in North Carolina,USA

Hydric soils are used as supportive evidence for wetland delineations by federal and state agencies and by the private sector in North Carolina, USA. An analysis of hydric soil distribution and hydric soil characteristics was conducted with county soil surveys and soil taxonomy of the USA. Approximately 100 hydric soils have been used for soil mapping in North Carolina, and they represent seven of the ten soil orders in soil taxonomy. An estimated 23% (2.9 million ha) of the land surface area in North Carolina supports hydric soils. Approximately 96% of the known hydric soil acreage was found in the coastal plain of North Carolina. Over one-third of the soils were hydric Ultisols, which represented close to 10% of the land surface area. The other soil orders with extensive hydric soil acreage included Histosols, Inceptisols, and Entisols. The soil orders were separated into great groups of soil taxonomy to discuss soil profile characteristics. Landscape positions and associated wetland communities were also presented. In North Carolina, a statewide inventory of wetlands does not exist and soil surveys offer a resource for a first approximation of wetland boundaries.     

循环经济视野下过度包装的立法思考

通过对国外包装立法的考察比较,提出限制过度包装必须由非理性的利益冲动行为回归到理智的法治轨道上来.应以促进循环经济发展,加快建设资源节约型和环境友好型社会,实现可持续发展为立法的终极价值目标.     

菜市场噪声对周围环境的影响

南方的菜场都有从凌晨开始即进行贸易的特点，以盐城市众多菜场中最具代表性的老虎桥露天菜场为例，对菜场噪声及其对环境的影响进行了监测与评价，并提出控制措施。