不同形态P对Cu、Zn、Cd联合生物毒性效应的影响

运用水潘趋光行为的抑制试验研究了水体中不同磷形态和重金属(Cu、Zn、Cd)共同存在时的联合生物毒性效应.结果表明,水体中重金属的生物毒性不仅取决于它们的种类和浓度,也与溶液中共存的P形态有关.重金属对水溞的生物毒性由强至弱依次为Cu2 ＞Zn2 ＞Cd2 ;当溶液中存在不同形态的P时,重金属的生物毒性发生了改变.中等P营养水平(TP为0.05mg·L-1)时,不同形态P的存在可显著降低Cu、Zn、Cd的生物毒性,在某种程度上减轻重金属对生物的伤害.不同形态P对重金属生物毒性的拮抗作用顺序为H2PO-4≈HPO24-＞PO34-.因此,重金属污染与富营养化双重胁迫水体的生物毒性,将可能因水体中P形态的不同而产生差异.     

利用水溞的趋光行为监测水质

以隆线溞(Daphniacarinata)单克隆Dc42为生物监测器,利用趋光指数变化监测水质.在不同水质样品中,水溞趋光指数随污染程度的提高而降低,根据趋光指数计算得到的污染指数能较好地反映水样的污染程度.在重铬酸钾标准毒物溶液中,趋光指数(Ip)与Cr⁶⁺的浓度呈极显著负相关,Cr⁶⁺浓度的检测下限为0.056mg/L,平均精度达到15.30%.     

Cleaner-client interactions on a Caribbean reef: influence of correlates of parasitism

We investigated the influence of known correlates of parasitism, namely fish density, body size and social behaviour, on three highly variable aspects of the interactions between cleaning gobies (Elacatinus spp.) and their clients, on a Barbadian coral reef. We specifically considered (1) variability in client visit rate to cleaning stations, (2) cleaning goby preference for specific clients and (3) variation in the time spent cleaning by cleaners. Using phylogenetically independent contrasts, we found that client species that were abundant on the reef visited cleaning stations more often than rarer client species. This could be due to the positive relationship between ectoparasite load and client density, or alternatively may simply reflect the frequency of contact between cleaners and clients. Cleaning gobies spent more time cleaning large-bodied clients, which usually have higher ectoparasite loads, although cleaning goby preference for clients was influenced by none of the correlates of client parasitism. Overall, factors assumed to correlate with ectoparasite load had a limited influence on the variability observed in the interactions between cleaning gobies and their clients. Received: 27 October 1999 / Received in revised form: 11 January 2000 / Accepted: 24 January 2000     

The social psychology of biodiversity conservation in agriculture

We investigate farmers’ intentions to apply biodiversity conservation practices from a psychological perspective, using an adapted version of the theory of planned behaviour (TPB), including group norms and putting emphasis on moral norms and self-identity. The study is based on a quantitative survey (n = 99) in Belgium, analysed using confirmatory factor analyses and path analysis. Results suggest that the impact of attitudes, social norms and perceived behavioural control on intentions is almost fully mediated through moral norms and self-identity. To have a sustained impact, change actions should strive to embed biodiversity conservation into the social norms and into the good farmer identity of the farming community. While acknowledging the explanatory nature of this study, the findings could suggest another view on how to induce behavioural change.     

Modelling pheromone anemotaxis for biosecurity surveillance: Moth movement patterns reveal a downwind component of anemotaxis

Insect pheromone traps are becoming an increasingly important tool in biosecurity and pest surveillance, alerting managers to the presence of unwanted organisms. To expand the role of these traps beyond their present sentinel role, it is necessary to develop reliable operational models of local insect dispersal. Following the detection of an insect incursion using a pheromone trap, such models could simulate the dispersal of the insect from its emergence site to the point of detection, enabling biosecurity managers to estimate the most likely proximal source of the incursion. An individual-based moth movement model was developed to simulate observed patterns of moth movement in response to the presence or absence of a pheromone. Using parameters derived from a genetic algorithm, it was possible to fit a model based on the three behavioural components (upwind, upwind with zigzags and casting) described in insect anemotaxis theory to a subset of observed movement patterns (0-135° to the wind), but not to the whole spectrum of movement patterns. It appears that current insect anemotaxis theory is missing a downwind flight component. Whilst the frequency of downwind movements is small; their ground speed could lead to significant downwind displacement, having a disproportionately strong influence on a moth movement model, and hence projections of the likely source or target locations.     

Ecological economics: themes, approaches, and differences with environmental economics

This article provides a short overview of the main themes of ecological economics (EE). It is argued that EE provides a platform that fosters multidisciplinary environmental research by bringing together the core contributing disciplines – economics and ecology. In addition, EE is regarded as a pluralistic approach to environmental research that can be set opposite to, and has indeed developed as a response to, traditional environmental and resource economics. A comparison of the two fields is presented to clarify the essential differences between them. In addition, specific themes are examined in more detail. These include: sustainable development; the growth debate; international trade; dynamic processes; and behaviour and policy. Electronic Publication     

Role of organic and black carbon in the chemical composition of atmospheric aerosol at European background sites

The mass concentrations of inorganic ions, water-soluble organic carbon, water-insoluble organic carbon and black carbon were determined in atmospheric aerosol collected at three European background sites: (i) the Jungfraujoch, Switzerland (high-alpine, PM_2.5 aerosol); (ii) K-puszta, Hungary (rural, PM_1.0 aerosol); (iii) Mace Head, Ireland (marine, total particulate matter). At the Jungfraujoch and K-puszta the contribution of carbonaceous compounds to the aerosol mass was higher than that of inorganic ions by 33% and 94%, respectively. At these continental sites about 60% of the organic carbon was water soluble, 55–75% of the total carbon proved to be refractory and a considerable portion of the water soluble, refractory organic matter was composed of humic-like substances. At Mace Head the mass concentration of organic matter was found to be about twice than that of nonsea-salt ions, 40% of the organic carbon was water soluble and the amount of highly refractory carbon was low. Humic-like substances were not detected but instead low molecular weight carboxylic acids were responsible for about one-fifth of the water-soluble organic mass. These results imply that the influence of carbonaceous compounds on aerosol properties (e.g. hygroscopic, optical) might be significant.     

The Behaviour of Selenium in Geological Processes

Selenium contents were analyzed from a total of 244 soil samples collected over different rock types at a sampling density of one sample per 4km² around Geita gold mining areas, Northwestern Tanzania. Comparisons using literature survey contents of selenium in geological materials and some implications on the selenium in soils are compiled and discussed. Most selenium occurs as simple selenides in small quantities in low temperature hydrothermal deposits devoid of sulphur. It has been observed that to a large extent selenium content is increased more than most trace elements in the upper parts of the Earth perhaps through extraterrestrial deposition. In deep-seated rocks selenium is associated with sulphur but being volatile selenium and sulphur do not behave according to the crystallochemical law. Due to the higher stability of S⁶⁺, Se⁴⁺ and Se⁰ separate during migration. Thus, selenium is especially found in deep-seated plutonic rocks where large magma bodies cooled slowly and sulphur is available to precipitate sulphides. Selenium, which occurs with sulphides, is inhomogeneously deposited into continental margins. It is increased during magmatic differentiation and is highest in basic rocks. In magmatic and metamorphic conditions, selenium is found in the crystal structures of sulphides while in pneumatolytic and hydrothermal processes, it is relatively enriched into the late differentiates compared to sulphur. In metamorphic rocks selenium is more widely distributed. Selenium content in soils in the investigated area varies from (0.3–0.5gg^–1) in laterite and in black cotton soil 0.4gg^–1. Of all volcanic rocks selenium is highest in volcanogenic rocks especially the basalts. Surface waters are enriched in selenium, which they leach from volcanic materials. Selenium in sediments containing clay and organic matter is elevated but the content decreases with increased metamorphism. Selenium in volcanic areas can be used as a pathfinder in prospecting for volcanogenic ore deposits. S/Se ratios are distinct in different rock types and can thus be used to elucidate the origin of rocks, ores, and sediments.     

Post‐acquisition integration processes in publicly owned professional service companies: Senior professional behaviour and company performance

The client relationships and tacit knowledge of professionals are professional service firms' (PSFs') major value creating resources producing challenges in generating post‐merger and acquisition value and risks of reducing the productivity or losing key professionals and their clients. The recent emergence of publicly owned PSFs and rapid growth through consolidating smaller privately owned firms potentially increases this risk by integrating small firms and their professionals into large public companies that may be governed very differently. This study explores post‐acquisition integration processes: professional behaviours and associated performance implications in two highly acquisitive publicly owned accounting companies. In one company, the integration process was rapid and heavily directed by senior management, while in the second company, integration was more gradual, initially undirected but then facilitated by senior management. The findings suggest that integration processes can impact the behaviour of professionals and acquiring firm performance. This research contributes to the understanding of post‐acquisition integration processes in PSFs and decision‐making and professional behaviour in recently emerged publicly owned PSFs. The study contributes to knowledge‐based theory by identifying factors that can affect the decision authority of executives and how organisational behaviour can constrain the implementation of executive integration decisions. Copyright © 2017 John Wiley & Sons, Ltd.     

Household waste behaviours among a community sample in Iran: An application of the theory of planned behaviour

Understanding the factors influencing recycling behaviour can lead to better and more effective recycling programs in a community. The goal of this study was to examine factors associated with household waste behaviours in the context of the theory of planned behaviour (TPB) among a community sample of Iranians that included data collection at time 1 and at follow-up one year later at time 2. Study participants were sampled from households under the coverage of eight urban health centers in the city of Qazvin. Of 2000 invited households, 1782 agreed to participate in the study. A self-reported questionnaire was used for assessing socio-demographic factors and the TPB constructs (i.e. attitude, subjective norms, perceived behavioural control, and intention). Furthermore, questions regarding moral obligation, self-identity, action planning, and past recycling behaviour were asked, creating an extended TPB. At time 2, participants were asked to complete a follow-up questionnaire on self-reported recycling behaviours. All TPB constructs had positive and significant correlations with each other. Recycling behaviour at time 1 (past behaviour) significantly related to household waste behaviour at time 2. The extended TPB explained 47% of the variance in household waste behaviour at time 2. Attitude, perceived behavioural control, intention, moral obligation, self-identity, action planning, and past recycling behaviour were significant predictors of household waste behaviour at time 2 in all models. The fact that the expanded TPB constructs significantly predicted household waste behaviours holds great promise for developing effective public campaigns and behaviour-changing interventions in a region where overall rates of household waste reduction behaviours are low. Our results indicate that educational materials which target moral obligation and action planning may be particularly effective.