Endocrine stress response in Oreochromis sp. from exposure to waterborne cadmium: the plasma cortisol analysis

Cadmium (Cd) is known as one of the most dangerous environmental and industrial pollutants. It has no biological function and accumulates mainly in metabolically active tissue even at low concentrations, which in turn may cause tissue damage. The effect of Cd on the endocrine systems of fish is not well known. To test the hypothesis that Cd is a chemical stressor, Oreochromis sp. were exposed to waterborne cadmium chloride and their endocrine stress response (plasma cortisol) was investigated after 4 days and 20 days. The plasma cortisol levels were analyzed using reverse-phase high performance liquid chromatography with UV detection (λ = 250 nm) after liquid–liquid extraction. The detection limit of the method was found to be 0.87 ng/mL plasma. This study provides evidence that Cd probably causes exhaustion of endocrine systems. Oreochromis sp. exposure to Cd resulted in a 15%–53% and 52%–91% suppression of cortisol release after 4 days and 20 days of exposure, respectively, in comparison with the control group. The results suggest that Cd still activates the endocrine system at 20 days and the interrenal cells of Oreochromis sp. were not impaired after 20 days of exposure to Cd.     

Human ecological effects of tropical storms in the coastal area of Ky Anh (Ha Tinh,Vietnam)

Vietnam is prone to tropical storms. Climate change effects contribute to sea level rise, floods, progression of the low water line and coastal erosion. This paper inventories the perception of local people, assesses and values main aspects of the livelihood damage caused by the tropical storms of the period 2008–2013 in three coastal communes of the Ky Anh District of the Ha Tinh Province in Central Vietnam. The communes were selected because the location of their coastal line is perpendicular to the storm itself, which made them prone to damage. The effects of increasingly extreme weather conditions on three communities in an area most affected by storms and floods on the local residents and their responses to these changing environmental conditions are analyzed and assessed. The results of questionnaires completed by randomly selected local inhabitants of these communes show that storms and related hazards such as flood, sea level rise and heavy rain are perceived as the most impacting climate change intensified phenomena on agriculture and aquaculture, livestock, household property and income. Opinions and measured data provided by the commune and district authorities allow estimating the total direct cost of the tropical storm at 1.56 million $US (The used conversion rate VND/$US is 21,730 when the research was conducted in 2014) during the period 2008–2013. The long-term costs of adaptation and social impact measures will be significantly higher. Details of the monetary figures allow identifying the physical and natural capital of the area as being most affected by the storm. Trend and cost analysis show that the total financial support for hazard prevention and management during 2014–2019 is estimated at 1.19 up to 1.32 million $US. Local stakeholders indicate that climate change adaptation should not be limited to technical measures such as strengthening dikes, but also should target planting protection forests and mangroves and land use planning. Financial support for the relocation policy, stakeholder involvement and integrating climate change adaptation in both the socioeconomic development master plan and local land use planning are also of importance.     

土地供给、房价与中国人口半城镇化

近十多年来,中国房价快速上涨,人口半城镇化率也随之迅速上升。针对这一现象,本文首次将土地供给、房价与人口半城镇化置于同一框架下进行系统分析,采用两阶段最小二乘法,以土地出让面积作为房价的工具变量,有效克服模型的内生性,从理论和实证两个方面研究了房价上涨对人口半城镇化的影响。结果发现:土地供给减少导致房价上涨,进而推升了人口半城镇化率,抑制了农村转移人口市民化。房价每上涨一个百分点,人口半城镇化率大约上升0.189 4个百分点。在未考虑内生性的情况下,房价对人口半城镇化的影响严重被低估。而2003年后土地供给政策收紧且向中西部地区偏移是导致东部房价上涨进而推升人口半城镇化率的重要根源。另外,还发现对外开放程度提高以及人力资本积累均有利于降低人口半城镇化率,相反,财政负担能力和户籍制度改革则产生了不利影响。因此,为了降低人口半城镇化率,有序促进农村转移人口市民化,提出如下三点政策建议:(1)调整土地供给政策,并且健全住房供应体系,防止房价上涨过快。为此,需要增加东部地区以及大城市的土地供给,使土地供给与人口流动方向以及经济发展需求相匹配,同时增加廉租房和保障房的供应。(2)大力发展工业、服务业,并提高对外开放程度,以创造更多就业机会,增加居民收入,进而促进地区人口城镇化。(3)深化户籍制度,切实放宽农村转移人口的落户条件,同时还需要深化财政制度改革,增加地方公共服务并努力促进公共服务均等化。     

Impact of metal stress on the production of secondary metabolites in <Emphasis Type="Italic">Pteris vittata</Emphasis> L. and associated rhizosphere bacterial communities

Plants adapt to metal stress by modifying their metabolism including the production of secondary metabolites in plant tissues. Such changes may impact the diversity and functions of plant associated microbial communities. Our study aimed to evaluate the influence of metals on the secondary metabolism of plants and the indirect impact on rhizosphere bacterial communities. We then compared the secondary metabolites of the hyperaccumulator Pteris vittata L. collected from a contaminated mining site to a non-contaminated site in Vietnam and identified the discriminant metabolites. Our data showed a significant increase in chlorogenic acid derivatives and A-type procyanidin in plant roots at the contaminated site. We hypothesized that the intensive production of these compounds could be part of the antioxidant defense mechanism in response to metals. In parallel, the structure and diversity of bulk soil and rhizosphere communities was studied using high-throughput sequencing. The results showed strong differences in bacterial composition, characterized by the dominance of Proteobacteria and Nitrospira in the contaminated bulk soil, and the enrichment of some potential human pathogens, i.e., Acinetobacter, Mycobacterium, and Cupriavidus in P. vittata’s rhizosphere at the mining site. Overall, metal pollution modified the production of P. vittata secondary metabolites and altered the diversity and structure of bacterial communities. Further investigations are needed to understand whether the plant recruits specific bacteria to adapt to metal stress.     

程序化的未确知测度模型用于水环境质量评价

未确知测度模型用于水环境质量评价具有合理性。为使模型更加完善,提出将未确知测度模型建立过程标准化,使其具有通用性。并针对水质评价指标众多致评价过程复杂、计算量大的情况,利用MATLAB软件将标准化后的未确知测度模型设计为既定的程序,依靠计算机模拟来实现水质评价。通过对浮桥河水库水质的评价结果及与其他多种方法的对比,表现出标准化模型的客观性、合理性,MATLAB程序的实用性、快捷性。程序化的未确知测度模型标准化后可进行推广。     

程序化的未确知测度模型用于水环境质量评价简

未确知测度模型用于水环境质量评价具有合理性。为使模型更加完善,提出将未确知测度模型建立过程标准化,使其具有通用性。并针对水质评价指标众多致评价过程复杂、计算量大的情况,利用MATLAB软件将标准化后的未确知测度模型设计为既定的程序,依靠计算机模拟来实现水质评价。通过对浮桥河水库水质的评价结果及与其他多种方法的对比,表现出标准化模型的客观性、合理性,MATLAB程序的实用性、快捷性。程序化的未确知测度模型标准化后可进行推广。     

Full-Scale Evaluation of the Thermal Stability-Based Hazardous Organic Waste Incinerability Ranking

De nombreuses études épidémiologiques ont observé dans des contextes différents une faible relation à court terme entre les particules et la mortalité cardio-pulmonaire, même quand les normes de qualité de l'air n'étaient pas dépassées. La causalité de cette relation est un enjeu de santé publique en raison de l'importance de la population exposée. Notre objectif est de faire l'inventaire critique des arguments utilisés dans 15 revues de la littérature publiées.

Nous expliquons l'importance de distinguer la validité de la causalité et analysons de façon systématique les différents critères de jugement dans le contexte des études écologiques temporelles. Notre conclusion est que la relation observée est valide et que la plupart des critères de causalité sont respectés. Diminuer le niveau d'exposition des populations aux particules est souhaitable. En Europe, en agissant à la source, notamment sur les émissions Diesel, on diminuera aussi d'autres polluants qui peuvent jouer un rôle sanitaire. Aux États-Unis, la situation est plus complexe car les particules sont surtout secondaires.

Il est également indispensable de poursuivre les recherches pour mieux connaître les déterminants des expositions globales des individus et mieux comprendre le rôle toxique des différents facteurs physico-chimiques des particules.     

Select indicators and prioritize solutions for desertification and drought in Binh Thuan,Vietnam

The link between climate change and desertification is an important global problem for the United Nations Framework Convention on Climate Change (UNFCCC) and the United Nations Convention to Combat Desertification (UNCCD). The coastal provinces in Southern Centre Vietnam are strongly influenced by desertification, which is further exacerbated by climate change. The Delphi method was used to select sustainability indicators and then a method of an analytical hierarchy process was applied to prioritize sustainable solutions in Binh Thuan experts to elicit the causes and effects of desertification. According to the panel of 23 experts, 27 cause (e.g. rainfall and sunshine duration) and 22 effect (e.g. rice and agriculture) indicators were of particular importance to desertification and drought in the province. The highest priorities for cause are given to emigration, followed by income from industry and water supply for household use. The highest priorities for effect in the area are given to socioeconomic criteria, and in particular to the sub-criteria resettlement due to development projects, building hydropower reservoirs, and implementing irrigation schemes. The system of indicators provides useful information for the future studies. This study provides a means to uncover the most important criteria perceived as major contributors to desertification and as such enables policy-makers to prioritize solutions for Binh Thuan (Vietnam) by 2015 and a vision in 2020.     

Long-term disruption of growth,reproduction, and behavior after embryonic exposure of zebrafish to PAH-spiked sediment

A natural sediment spiked with three individual polycyclic aromatic hydrocarbons (PAHs; pyrene, phenanthrene and benzo[a]pyrene) was used to expose zebrafish embryos and larvae during 4 days. The total PAH concentration was 4.4 μg g^?1 which is in the range found in sediment from contaminated areas. Quantification of metabolites in the larvae after exposure confirmed the actual contamination of the larvae and indicated an active metabolism especially for pyrene and benzo[a]pyrene. After a transfer in a clean medium, the larvae were reared to adulthood and evaluated for survival, growth, reproduction, and behavior. Measured endpoints revealed a late disruption of growth (appearing at 5 months) and a trend toward a lower reproductive ability. Adults of embryos exposed to sediment spiked with PAHs displayed lethargic and/or anxiety-like behaviors. This latter behavior was also identified in offspring at larval stage. All together, these effects could have detrimental consequences on fish performances and contribution to recruitment.