安捷伦液相/离子阱(XCT)质谱检测虾仁及家禽中的硝基呋喃代谢物

在液相/离子阱质谱上,利用液相/质谱/质谱方法对鸡肉及虾仁中硝基呋喃代谢物残留进行了定性定量分析.对于四种硝基呋喃代谢物,其定量限在0125到05μg·kg-1的范围内,分析结果完全满足欧盟的1μg·kg-1的最低检测限量的要求.     

Antecedents and consequences of empowering leadership: Leader power distance,leader perception of team capability,and team innovation

The evidence that empowering leadership is an effective form of team leadership brings the question on what the antecedents of empowering leadership are into focus. We propose that empowering leadership is driven by considerations of the normative and situational appropriateness of empowering leadership that are associated with leader power distance value and leader perception of team capability. We propose that leader power distance and perceived team capability interact such that the influence of leader power distance on empowering leadership is stronger with higher perceived team capability. We extend our model to show that by affecting empowering leadership, the interaction of leader power distance and perceived team capability indirectly influences team innovation, an important team outcome associated with empowered teamwork. We tested our model in two multisource surveys in China: Study 1 of 84 technical teams and Study 2 of 83 financial service teams. We discuss how our study contributes to empowering leadership theory by providing a theoretical perspective that lends itself well to identifying other trait and situational antecedents of empowering leadership.     

Modeling emissions for three-dimensional atmospheric chemistry transport models

Poor air quality is still a threat for human health in many parts of the world. In order to assess measures for emission reductions and improved air quality, three-dimensional atmospheric chemistry transport modeling systems are used in numerous research institutions and public authorities. These models need accurate emission data in appropriate spatial and temporal resolution as input. This paper reviews the most widely used emission inventories on global and regional scales and looks into the methods used to make the inventory data model ready. Shortcomings of using standard temporal profiles for each emission sector are discussed, and new methods to improve the spatiotemporal distribution of the emissions are presented. These methods are often neither top-down nor bottom-up approaches but can be seen as hybrid methods that use detailed information about the emission process to derive spatially varying temporal emission profiles. These profiles are subsequently used to distribute bulk emissions such as national totals on appropriate grids. The wide area of natural emissions is also summarized, and the calculation methods are described. Almost all types of natural emissions depend on meteorological information, which is why they are highly variable in time and space and frequently calculated within the chemistry transport models themselves. The paper closes with an outlook for new ways to improve model ready emission data, for example, by using external databases about road traffic flow or satellite data to determine actual land use or leaf area. In a world where emission patterns change rapidly, it seems appropriate to use new types of statistical and observational data to create detailed emission data sets and keep emission inventories up-to-date.

Implications: Emission data are probably the most important input for chemistry transport model (CTM) systems. They need to be provided in high spatial and temporal resolution and on a grid that is in agreement with the CTM grid. Simple methods to distribute the emissions in time and space need to be replaced by sophisticated emission models in order to improve the CTM results. New methods, e.g., for ammonia emissions, provide grid cell–dependent temporal profiles. In the future, large data fields from traffic observations or satellite observations could be used for more detailed emission data.     

Acute toxicity of chlorpyrifos to embryo and larvae of banded gourami Trichogaster fasciata

This study elucidated the acute toxicity of chlorpyrifos on the early life stages of banded gourami (Trichogaster fasciata). To determine the acute effects of chlorpyrifos on their survival and development, we exposedthe embryos and two-day-old larvae to six concentrations (0, 0.01, 0.10, 1.0, 10 and 100 µg L^?1) of chlorpyrifos in plastic bowls. Log-logistic regression was used to calculate LC10 and LC50 values. Results showed that embryo mortality significantly increased with increasing chlorpyrifos concentrations. The 24-h LC10 and LC50 values (with 95% confidence limits) of chlorpyrifos for embryos were 0.89 (0.50–1.58) and 11.8 (9.12–15.4) µg L^?1, respectively. Hatching success decreased and mortality of larvae significantly increased with increasing concentrations of chlorpyrifos. The 24-h LC10 and LC50 values (with 95% confidence limits) of chlorpyrifos for larvae were 0.53 (0.27–1.06) and 21.7 (15.9–29.4) µg L^?1, respectively; the 48-h LC10 and LC50 for larvae were 0.04 (0.02–0.09) and 5.47 (3.77–7.94) µg L^?1, respectively. The results of this study suggest that 1 µg L^?1 of chlorpyrifos in the aquatic environment may adversely affect the development and the reproduction of banded gourami. Our study also suggests that banded gourami fish can serve as an ideal model species for evaluating developmental toxicity of environmental contaminants.     

Relating to nature,food and community in community gardens

This paper sheds critical light on the motivations and practices of community gardeners in relatively affluent neighbourhoods. The paper engages with community garden, alternative food and domestic garden literatures, to understand how people fit food production into their everyday lives, how they develop relationships to plants and how these in turn shape relations between people in a community group. The paper draws on participant observation and semi-structured walking interviews conducted at three community gardens in Sydney, Australia. The paper concludes that to fit community gardening into busy lives, people strategically choose plants with biophysical qualities that suit personal as well as communal circumstances and objectives. The paper shows how community is relationally constituted through the practices of growing and sharing food. Tensions might arise through the practices of growing food on communal and private plots and the taking and giving of food, but it can also encourage people to reflect on community food production and on their roles as individuals in a community group.     

An expanded conceptual framework for solution-focused management of chemical pollution in European waters

Background

This paper describes a conceptual framework for solutions-focused management of chemical contaminants built on novel and systematic approaches for identifying, quantifying and reducing risks of these substances.

Methods

The conceptual framework was developed in interaction with stakeholders representing relevant authorities and organisations responsible for managing environmental quality of water bodies. Stakeholder needs were compiled via a survey and dialogue. The content of the conceptual framework was thereafter developed with inputs from relevant scientific disciplines.

Results

The conceptual framework consists of four access points: Chemicals, Environment, Abatement and Society, representing different aspects and approaches to engaging in the issue of chemical contamination of surface waters. It widens the scope for assessment and management of chemicals in comparison to a traditional (mostly) perchemical risk assessment approaches by including abatement- and societal approaches as optional solutions. The solution-focused approach implies an identification of abatement- and policy options upfront in the risk assessment process. The conceptual framework was designed for use in current and future chemical pollution assessments for the aquatic environment, including the specific challenges encountered in prioritising individual chemicals and mixtures, and is applicable for the development of approaches for safe chemical management in a broader sense. The four access points of the conceptual framework are interlinked by four key topics representing the main scientific challenges that need to be addressed, i.e.: identifying and prioritising hazardous chemicals at different scales; selecting relevant and efficient abatement options; providing regulatory support for chemicals management; predicting and prioritising future chemical risks. The conceptual framework aligns current challenges in the safe production and use of chemicals. The current state of knowledge and implementation of these challenges is described.

Conclusions

The use of the conceptual framework, and addressing the challenges, is intended to support: (1) forwarding sustainable use of chemicals, (2) identification of pollutants of priority concern for cost-effective management, (3) the selection of optimal abatement options and (4) the development and use of optimised legal and policy instruments.

     

Differentiating the effects of climate and land use change on European biodiversity: A scenario analysis

Current observed as well as projected changes in biodiversity are the result of multiple interacting factors, with land use and climate change often marked as most important drivers. We aimed to disentangle the separate impacts of these two for sets of vascular plant, bird, butterfly and dragonfly species listed as characteristic for European dry grasslands and wetlands, two habitats of high and threatened biodiversity. We combined articulations of the four frequently used SRES climate scenarios and associated land use change projections for 2030, and assessed their impact on population trends in species (i.e. whether they would probably be declining, stable or increasing). We used the BIOSCORE database tool, which allows assessment of the effects of a range of environmental pressures including climate change as well as land use change. We updated the species lists included in this tool for our two habitat types. We projected species change for two spatial scales: the EU27 covering most of Europe, and the more restricted biogeographic region of ‘Continental Europe’. Other environmental pressures modelled for the four scenarios than land use and climate change generally did not explain a significant part of the variance in species richness change. Changes in characteristic bird and dragonfly species were least pronounced. Land use change was the most important driver for vascular plants in both habitats and spatial scales, leading to a decline in 50–100% of the species included, whereas climate change was more important for wetland dragonflies and birds (40–50 %). Patterns of species decline were similar in continental Europe and the EU27 for wetlands but differed for dry grasslands, where a substantially lower proportion of butterflies and birds declined in continental Europe, and 50 % of bird species increased, probably linked to a projected increase in semi-natural vegetation. In line with the literature using climate envelope models, we found little divergence among the four scenarios. Our findings suggest targeted policies depending on habitat and species group. These are, for dry grasslands, to reduce land use change or its effects and to enhance connectivity, and for wetlands to mitigate climate change effects.     

Exploring future agricultural development and biodiversity in Uganda,Rwanda and Burundi: a spatially explicit scenario-based assessment

Regional Environmental Change - Competition for land is increasing as a consequence of the growing demands for food and other commodities and the need to conserve biodiversity and ecosystem...     

Communication Practices and Political Engagement with Climate Change: A Research Agenda

In this article, we call for a refocusing of research on citizens’ political engagement with climate change. In doing so, we argue that communication practices not only help create the conditions for political engagement but they also comprise the modes of such engagement. Our argument proceeds in four steps. First, we review the literature on public engagement with climate change, concluding that there is a lack of attention to issues regarding the political. Consequently, we make the case for a refocusing of research on political engagement. Second, we explain how the notion of political subjectivity helps us to understand the relation between communication practices and engagement with the politics of climate change. Third, we discuss examples of dominant communication practices that constrain citizen political engagement by depoliticizing climate change, and alternative communication practices that have the potential to politicize. We end by outlining the many research questions that relate to the study of political engagement with climate change.     

Behaviour of horses and cattle at two stocking densities in a coastal salt marsh

Livestock grazing has been practiced in salt marshes in the Wadden Sea area since 600 B.C. Currently livestock grazing is also applied for conservation management. However, effects of such grazing management on salt marshes are likely to vary depending on the species of livestock and stocking density due to differences in the behaviour of the animals. Yet, little is known about the behaviour of different livestock species and stocking densities grazing in salt marshes. We studied the grazing behaviour of horses and cattle by focal observation in an experiment with four different grazing treatments on a coastal salt marsh. In all treatments we recorded diet choice, movement and grazing activity, and spatial distribution. Livestock species shared an overlap in diet choice. Yet, horses more often foraged on the short grass Puccinellia maritima, while the cattle diet contained a higher amount of Aster tripolium. Horses travelled longer distances per day and spent more time grazing than cattle. Spatial distribution of cattle was significantly clustered, while horses showed a random distribution utilizing the whole area. Animal behaviour differs between livestock species and stocking densities with respect to diet choice, activity and spatial distribution.