Biodegradability of the anticancer drug etoposide and identification of the transformation products

Etoposide susceptibility to microbiological breakdown was studied in a batch biotransformation system, in the presence or absence of artificial wastewater containing nutrients, salts and activated sludge at two concentration levels. The primary focus of the present study was to study etoposide transformation products by ultra-high performance liquid chromatography coupled to high-resolution hybrid quadrupole-Orbitrap tandem mass spectrometry (MS/MS). Data-dependent experiments combining full-scan MS data with product ion spectra were acquired to identify the molecular ions of etoposide transformation products, to propose the molecular formulae and to elucidate their chemical structures. Due to the complexity of the matrix, visual inspection of the chromatograms showed no clear differences between the controls and the treated samples. Therefore, the software package MZmine was used to facilitate the identification of the transformation products and speed up the data analysis. In total, we propose five transformation products; among them, four are described as etoposide transformation products for the first time. Even though the chemical structures of these new compounds cannot be confirmed due to the lack of standards, their molecular formulae can be used to target them in monitoring studies.     

Influence of Al-oxide on pesticide sorption to woody biochars with different surface areas

Biochars’ properties will change after application in soil due to the interactions with soil constituents, which would then impact the performance of biochars as soil amendment. For a better understanding on these interactions, two woody biochars of different surface areas (SA) were physically treated with aluminum oxide (Al-oxide) to investigate its potential influence on biochars’ sorption property. Both the micropore area and mesopore (17～500 Å in diameter) area of the low-SA biochar were enhanced by at least 1.5 times after treatment with Al-oxide, whereas the same treatment did not change the surface characteristics of the high-SA biochar due partly to its well-developed porosity. The enhanced sorption of the pesticide isoproturon to the Al-oxide-treated low-SA biochar was observed and is positively related to the increased mesopore area. The desorption hysteresis of pesticide from the low-SA biochar was strengthened because of more pesticide molecules entrapped in the expanded pores by Al-oxide. However, no obvious change of pesticide sorption to the high-SA biochar after Al-oxide treatment was observed, corresponding to its unchanged porosity. The results suggest that the influence of Al-oxide on the biochars’ sorption property is dependent on their porosity. This study will provide valuable information on the use of biochars for reducing the bioavailability of pesticides.     

Fluoride in weathered rock aquifers of southern India: Managed Aquifer Recharge for mitigation

Climatic condition, geology, and geochemical processes in an area play a major role on groundwater quality. Impact of these on the fluoride content of groundwater was studied in three regions—part of Nalgonda district in Telangana, Pambar River basin, and Vaniyar River basin in Tamil Nadu, southern India, which experience semi-arid climate and are predominantly made of Precambrian rocks. High concentration of fluoride in groundwater above 4 mg/l was recorded. Human exposure dose for fluoride through groundwater was higher in Nalgonda than the other areas. With evaporation and rainfall being one of the major contributors for high fluoride apart from the weathering of fluoride rich minerals from rocks, the effect of increase in groundwater level on fluoride concentration was studied. This study reveals that groundwater in shallow environment of all three regions shows dilution effect due to rainfall recharge. Suitable managed aquifer recharge (MAR) methods can be adopted to dilute the fluoride rich groundwater in such regions which is explained with two case studies. However, in deep groundwater, increase in fluoride concentration with increase in groundwater level due to leaching of fluoride rich salts from the unsaturated zone was observed. Occurrence of fluoride above 1.5 mg/l was more in areas with deeper groundwater environment. Hence, practicing MAR in these regions will increase the fluoride content in groundwater and so physical or chemical treatment has to be adopted. This study brought out the fact that MAR cannot be practiced in all regions for dilution of ions in groundwater and that it is essential to analyze the fluctuation in groundwater level and the fluoride content before suggesting it as a suitable solution. Also, this study emphasizes that long-term monitoring of these factors is an important criterion for choosing the recharge areas.     

Evaluation of the efficacy of a portable LIBS system for detection of CWA on surfaces

Laser-induced breakdown spectroscopy (LIBS) is a laser-based optical technique particularly suited for in situ surface analysis. A portable LIBS instrument was tested to detect surface chemical contamination by chemical warfare agents (CWAs). Test of detection of surface contamination was carried out in a toxlab facility with four CWAs, sarin (GB), lewisite (L1), mustard gas (HD), and VX, which were deposited on different substrates, wood, concrete, military green paint, gloves, and ceramic. The CWAs were detected by means of the detection of atomic markers (As, P, F, Cl, and S). The LIBS instrument can give a direct response in terms of detection thanks to an integrated interface for non-expert users or so called end-users. We have evaluated the capability of automatic detection of the selected CWAs. The sensitivity of our portable LIBS instrument was confirmed for the detection of a CWA at surface concentrations above 15 μg/cm². The simultaneous detection of two markers may lead to a decrease of the number of false positive.     

Emissions from oil and gas operations in the United States and their air quality implications

The energy supply infrastructure in the United States has been changing dramatically over the past decade. Increased production of oil and natural gas, particularly from shale resources using horizontal drilling and hydraulic fracturing, made the United States the world’s largest producer of oil and natural gas in 2014. This review examines air quality impacts, specifically, changes in greenhouse gas, criteria air pollutant, and air toxics emissions from oil and gas production activities that are a result of these changes in energy supplies and use. National emission inventories indicate that volatile organic compound (VOC) and nitrogen oxide (NO_x) emissions from oil and gas supply chains in the United States have been increasing significantly, whereas emission inventories for greenhouse gases have seen slight declines over the past decade. These emission inventories are based on counts of equipment and operational activities (activity factors), multiplied by average emission factors, and therefore are subject to uncertainties in these factors. Although uncertainties associated with activity data and missing emission source types can be significant, multiple recent measurement studies indicate that the greatest uncertainties are associated with emission factors. In many source categories, small groups of devices or sites, referred to as super-emitters, contribute a large fraction of emissions. When super-emitters are accounted for, multiple measurement approaches, at multiple scales, produce similar results for estimated emissions. Challenges moving forward include identifying super-emitters and reducing their emission magnitudes. Work done to date suggests that both equipment malfunction and operational practices can be important. Finally, although most of this review focuses on emissions from energy supply infrastructures, the regional air quality implications of some coupled energy production and use scenarios are examined. These case studies suggest that both energy production and use should be considered in assessing air quality implications of changes in energy infrastructures, and that impacts are likely to vary among regions.

Implications: The energy supply infrastructure in the United States has been changing dramatically over the past decade, leading to changes in emissions from oil and natural gas supply chain sources. In many source categories along these supply chains, small groups of devices or sites, referred to as super-emitters, contribute a large fraction of emissions. Effective emission reductions will require technologies for both identifying super-emitters and reducing their emission magnitudes.     

Simulative governance: on the collaborative narrative of civil society participation in the CDM stakeholder framework

The Kyoto Protocol’s Clean Development Mechanism (CDM) is often cited as an exemplar of new, hybrid forms of global environmental governance operating at the public–private interface. Practically, enacting this arrangement involves a wide range of non-state actors. This broad involvement is here assumed to mark a shift towards more polycentric and networked modes of governance in which agents collaborate as ‘stakeholders’ in the process of consensual rule-setting and implementation. Using post-political critique, the depoliticising effects of the stakeholder framework on civil society actors are interrogated, using formal and informal participation opportunities to raise concerns regarding specific CDM projects. The analysis suggests that the CDM’s collaborative narrative of stakeholding structurally fails to stimulate public (re)engagement and is, instead, a prime example of simulative governance that struggles to achieve the simultaneity of two incompatibilities: the participatory revolution and the post-political turn.     

Religion and environmental politics in the US House of Representatives

Does religion affect legislators’ behavior on environmental policy in the US? Studies of environmental policy making have not examined this question, although the literature suggests that religion might affect legislative behavior on environmental policy. This study examines the relationship between US House members’ religion and roll-call voting on environmental legislation from 1973 to 2009. It finds significant differences across religious traditions. Legislators’ party and characteristics of constituencies relevant to environmental politics increasingly, but not entirely, mediate these differences.     

南方丘陵地区河谷城市用地时空演变与驱动分析——以上饶市城区为例

以揭示中国南方丘陵地区河谷城市的空间演变过程和特征为目的,以上饶市城区为例,在遥感与GIS技术的支持下,对1988~2013年间上饶市城区城市用地的时空演变过程、特征及驱动影响因素进行了研究。结果表明,1988~2013年的25 a间,上饶市城区城市用地呈现出快速增长的态势,城市形态的演变具有明显的时空特征:时间序列上,不论扩展幅度还是扩展速度,2001~2013年间的值均高于1988~2001年间的值,前后两个时段的扩展特征呈现出明显的差异性;空间格局上,上饶市城区以老城区的中心广场为中心向四周扩展,先后经历了放射性扩展、组团式分散扩展两个阶段,同时呈现出明显的方向分异性,西南和西为其主要扩展方向,而其东南方向的扩展速度最为缓慢。自然环境中的地貌对上饶市城区城市用地的扩展起到很大的限制作用,经济社会的发展、政策规划等因素成为城市用地扩张与时空演化的外在驱动因素。     

Effect of fires on the functioning of phytocenoses of peat bogs in the Middle-Amur lowland

The dynamics and structure of the phytomass and production of an undisturbed mesotrophic dwarf shrub–sphagnum phytocenosis and one burned by fire have been compared. The net primary production (NPP) of both sites of phytocenoses in the postpyrogenic period is estimated by direct field determination of the productivity parameters, and C emission from the fire is assessed. The obtained data on emission (0.7 kg/m²) differ from the results obtained in the peatlands of western Canada (3.2 kg/m²).