Ivermectin dissipation and movement from feces to soil under field conditions

The aim of this work was to evaluate the fate of ivermectin (IVM) at two concentrations in cattle feces and its movement to the nearby soil and plants. Feces were spiked with IVM at two levels: 3000 ng g^?1 (high group, HG) and 300 ng g^?1 (low group, LG). Artificial dung pats were prepared and deposited in an experimental field area. Feces and underlying soil were sampled up to 60 days post-deposition (dpd). As an additional analysis, grasses growing around the pats were sampled at 30 and 60 dpd. Ivermectin concentrations in all matrices were determined by HPLC. Mean IVM fecal concentrations were in the range between 3901.9 ng g^?1 and 2419.2 ng g^?1 (high group) and 375.3 ng g^?1 and 177.49 ng g^?1 (low group). Mean times for 50% and 90% dissipation were 88.23 and 293.03 days (HG) and 39.1 and 129.9 days (LG). Soil concentrations ranged from 26.1 ng g^?1 to 71.1 ng g^?1 (HG) and 3.4 to 5.9 ng g^?1 (LG); in plants, concentrations were between 71.4 and 380.8 ng g^?1 and 5.40 and 51.8 ng g^?1 in HG and LG, respectively. These results confirm that IVM moves from feces to the underlying soil as well as to nearby plants. The potential risk of detrimental effects on soil organisms and the impact on herbivorous animals should be further evaluated.     

长江经济带农业用水全局技术效率的空间效应研究

基于全局DEA方法测算了1997~2015年长江经济带11省市的农业用水全局技术效率,并运用 Moran’s I 指数和空间计量模型分析了农业用水效率的空间关联度和空间效应。研究表明：(1）长江经济带农业用水全局技术效率表现出整体稳定上升但地区间不平衡的特征,且地区之间存在显著的正空间自相关;(2）空间计量模型的估计结果表明地区之间农业用水全局技术效率存在显著的空间溢出效应,本地农业用水效率不仅受到邻接地区的影响,还会受到非邻接地区的影响;除了地理因素之外,经济发展和生产力水平相近也有利于地区间农业用水主体相互学习高效率的用水模式,从而引发农业用水效率的空间溢出效应,促进整体农业用水效率的提升;（3)总用水量中农业用水量所占的比例高,会使得农业用水效率显著降低;水利设施建设以及农业机械化程度都会对农业用水效率产生显著的正向促进效应。     

Land cover effects on water balance partitioning in the Colombian Andes: improved water availability in early stages of natural vegetation recovery

Regional Environmental Change - Vegetation actively affects different components of the water budget in multiple spatial and temporal scales. Changes in vegetation cover and structure—such as...     

中部3省城市建设用地功能时空演化特征

定量识别区域城市建设用地功能演化特征与模式,是推进可持续城市建设用地开发利用与管理、助力新型城镇化等国家战略的重要基础。从人口承载、生产与消费、公共服务3个方面构建了城市建设用地功能评价指标体系与模型,以地级市为研究单元探究了2000~2014年期间我国中部3省多尺度城市建设用地功能演化特征与模式。研究结果表明:(1)中部3省城市建设用地人口承载、生产与消费、公共服务和综合功能总体呈改善趋势,但演化过程复杂;(2)不同尺度尤其是城市群地区城市建设用地功能演化特征差异明显。沿长江和城市群地区城市建设用地功能演化强度高,但城市群地区空间异质性较强;(3)城市建设用地功能演化以复合型演化模式为主,演化格局复杂。其中,城市建设用地人口承载功能演化模式类型最多,且局部地区呈衰退型演化格局;城市建设用地生产与消费、公共服务功能和综合功能演化模式类型相对较少,且大多集中连片分布,武汉城市建设用地综合功能加速改善型演化特征显著。如何深入探究城市建设用地功能演化模式形成机理,并系统制定多级城市建设用地可持续利用管理策略,是实现我国新型城镇化和"美丽中国梦"等战略的重要任务。     

Genotoxicity assessment of human peripheral Lymphocytes induced by thallium(I) and thallium(III)

Thallium is a non-essential metal with a wide range of industrial uses. However, thallium is also a potential pollutant with high potential toxicity to humans. In the present study, we analyzed and compared the cellular and genotoxic effects of thallium in two main oxidation states by applying chromosome aberration assays to human peripheral lymphocytes. We observed that thallium(I) sulfate reduced the mitotic index at all tested concentrations (0.5, 1, 5, 50 and 100 μg/mL), whereas thallium(III) chloride was toxic at concentrations ≥1 μg/mL. Thallium(I) and thallium(III) treatment significantly increased structural chromosomal aberrations, with and without gaps, and increased the percentage of aberrant cells without gaps. Furthermore, satellite associations and numerical chromosomal aberration tests showed significant differences at a few of the tested concentrations. The satellite association test is related to aneuploidy. Thallium salts increased satellite associations when hyperploid cells were observed. Our results indicated that the two oxidation states of thallium induced toxicity in vitro – i.e. cyto/genotoxic (clastogenic and aneuploidogenic) effects.     

Distal impacts of aquarium trade: Exploring the emerging sandhopper (<Emphasis Type="Italic">Orchestoidea tuberculata</Emphasis>) artisanal shore gathering fishery in Chile

Artisanal fishery activities support the livelihoods of millions of people worldwide, particularly in developing countries. Within these fisheries, distal global drivers can promote switching between alternative target resources. These drivers can promote the rapid development of new, unregulated and previously unexploited fisheries that pose a threat to the sustainability of ecosystems. In this paper, we describe a new artisanal shore gathering activity that targets a previously unexploited resource: the sandhopper (Orchestoidea tuberculata). The activity is driven by aquarium trade demand for food. We used mixed methods to describe the activity, assessed basic socio-economic incentives, and estimated Catches per Unit Effort. Results show that the sandhopper plays an important role for the livelihoods of shore gatherers engaged in the activity. Gatherers have adapted and developed two main extraction methods with different degrees of investment and extraction rates. Furthermore, gatherers have developed local knowledge regarding the ecology and management of the resource. Results show that economic incentives can motivate a rapid expansion of this unregulated activity. Future research gaps and management options to address the development of this fishery are discussed in light of these findings.     

Achieving biodiversity benefits with offsets: Research gaps,challenges, and needs

Biodiversity offsets are becoming increasingly common across a portfolio of settings: national policy, voluntary programs, international lending, and corporate business structures. Given the diversity of ecological, political, and socio-economic systems where offsets may be applied, place-based information is likely to be most useful in designing and implementing offset programs, along with guiding principles that assure best practice. We reviewed the research on biodiversity offsets to explore gaps and needs. While the peer-reviewed literature on offsets is growing rapidly, it is heavily dominated by ecological theory, wetland ecosystems, and U.S.-based research. Given that majority of offset policies and programs are occurring in middle- and low-income countries, the research gaps we identified present a number of risks. They also present an opportunity to create regionally based learning platforms focused on pilot projects and institutional capacity building. Scientific research should diversify, both topically and geographically, in order to support the successful design, implementation, and monitoring of biodiversity offset programs.     

Are children playgrounds safe play areas? Inorganic analysis and lead isotope ratios for contamination assessment in recreational (Brazilian) parks

Environmental Science and Pollution Research - In city playgrounds, there is a potential risk of harming children’s health by contamination coming from anthropogenic activities. With the aim...     

可见光下氮掺杂罗丹明B分子印迹TiO_2的选择性光催化性能

采用溶胶-凝胶法和分子印迹技术,以尿素为氮源、罗丹明B为模板分子制备了氮掺杂罗丹明B分子印迹TiO_2粉末(N-TiO_2-RhB),并对样品进行了XRD、UV-Vis DRS和BET表征。表征结果显示:氮掺杂和分子印迹一定程度改善了样品的孔隙结构和孔径分布,N-TiO_2-RhB的比表面积和孔体积分别为TiO_2的1.9倍和1.5倍;氮掺杂使TiO_2的光吸收带边发生红移,而分子印迹不能改变催化剂的光吸收带边。N-TiO_2-RhB具有最佳的可见光活性和选择性,对罗丹明B的降解率高达92.7%。对罗丹明B、罗丹明6G、甲基紫和甲基绿的降解过程均符合一级反应动力学方程。     

多级孔ZSM-5分子筛对亚甲基蓝的吸附性能

以多级孔ZSM-5分子筛为吸附剂,吸附水中的亚甲基蓝（MB）,考察了吸附条件对吸附效果的影响,并探讨了吸附的热力学和动力学特征。实验结果表明：在溶液pH为11、分子筛加入量为800 mg/L、吸附温度为303.15 K、吸附时间为60 min、初始MB质量浓度为20 mg/L的条件下,该分子筛对MB的吸附率达97%;溶液pH为5~12时,吸附率均达89%以上,说明该分子筛具有宽的pH适应范围;该分子筛对MB的吸附热力学符合Langmuir和Freundlich方程,293.15~313.15 K的饱和吸附量达50.51~62.11 mg/g,吸附为吸热、自发过程;吸附动力学符合拟二级动力学方程。