The role of age in temporal polyethism in a primitively eusocial wasp

The relation of age to division of labor was assessed in a primitively eusocial wasp, Ropalidia marginata. The performance of four functionally significant tasks was analyzed. It was found that age has a definite correlation with division of labor, since wasps performed tasks in a distinct sequence in their life with successive tasks being initiated at significantly older ages. Age of a wasp was measured in absolute terms and also relative to other individuals in the colony. Probability of performance of a given task relative to other tasks (PTP) and absolute rates at which tasks were performed per unit time (FTP) both showed clear age-dependent patterns, confirming the association of age with division of labor. The proportion of variance explained for both PTP and FTP was significantly higher with relative age than with absolute age. Interindividual interactions were found to be a potential mechanism through which wasps can determine their relative age. The advantages of work organization depending on relative age and the constraints imposed by absolute age are discussed. Received: 2 April 1997 / Accepted after revision: 20 July 1997     

微板吸光法测定9种农药对斜生栅藻的抑制毒性

以斜生栅藻(Scenedesmus obliquus)为指示生物,96微孔板为暴露反应载体,SpectraMax M5酶标仪为吸光度测试设备,建立了测定毒物对藻生长抑制毒性的微板吸光法.论文系统研究了微板吸光法中斜生栅藻的可见吸收光谱和生长曲线以及pH和暴露时间对藻生长的影响,同时应用该方法成功测定了环嗪酮、阿特拉津、西草净、扑灭通、苯嗪草酮、敌草快、草甘膦7种除草剂和磷胺、甲胺磷2种杀虫剂对斜生栅藻的剂量-效应曲线(DRC).通过对剂量-效应数据进行非线性最小二乘模拟,获得了这些农药的半数效应浓度EC50及置信区间.对比标准锥形瓶栅藻毒性试验,微板吸光法具有测试简便快速,所需样品体积少,便于多次平行毒性测试等优点.     

Earth stewardship: Shaping a sustainable future through interacting policy and norm shifts

Transformation toward a sustainable future requires an earth stewardship approach to shift society from its current goal of increasing material wealth to a vision of sustaining built, natural, human, and social capital—equitably distributed across society, within and among nations. Widespread concern about earth’s current trajectory and support for actions that would foster more sustainable pathways suggests potential social tipping points in public demand for an earth stewardship vision. Here, we draw on empirical studies and theory to show that movement toward a stewardship vision can be facilitated by changes in either policy incentives or social norms. Our novel contribution is to point out that both norms and incentives must change and can do so interactively. This can be facilitated through leverage points and complementarities across policy areas, based on values, system design, and agency. Potential catalysts include novel democratic institutions and engagement of non-governmental actors, such as businesses, civic leaders, and social movements as agents for redistribution of power. Because no single intervention will transform the world, a key challenge is to align actions to be synergistic, persistent, and scalable.     

Coal mining and the resource community cycle: A longitudinal assessment of the social impacts of the Coppabella coal mine

Two social impact assessment (SIA) studies of Central Queensland's Coppabella coal mine were undertaken in 2002–2003 and 2006–2007. As ex post studies of actual change, these provide a reference point for predictive assessments of proposed resource extraction projects at other sites, while the longitudinal element added by the second study illustrates how impacts associated with one mine may vary over time due to changing economic and social conditions. It was found that the traditional coupling of local economic vitality and community development to the life cycle of resource projects—the resource community cycle—was mediated by labour recruitment and social infrastructure policies that reduced the emphasis on localised employment and investment strategies, and by the cumulative impacts of multiple mining projects within relative proximity to each other. The resource community cycle was accelerated and local communities forced to consider ways of attracting secondary investment and/or alternative industries early in the operational life of the Coppabella mine in order to secure significant economic benefits and to guard against the erosion of social capital and the ability to cope with future downturns in the mining sector.     

Testing the limits of social resilience in ant colonies

Social resilience is the ability of Leptothorax ant colonies to re-assemble after dissociation, as caused, for example, by an emigration to a new nest site. Through social resilience individual workers re-adopt their spatial positions relative to one another and resume their tasks without any time being wasted in worker respecialisation. Social resilience can explain how an efficient division of labour can be maintained throughout the trials and tribulations of colony ontogeny including the, often substantial, period after the queen dies when the ability to conserve worker social relationships may be essential for efficiency to be maintained. The mechanism underlying social resilience is, therefore, expected to be robust even in the absence of many of the colony’s components, such as the queen, the brood and even a large proportion of the workers. Such losses are likely, given the ecology of this genus. Using sociotomy experiments, we found that social resilience can occur in the absence of the queen. Furthermore, the spatial component of social resilience can occur even when the queen, the brood, as well as a large proportion of the workers, are all absent simultaneously and hence many of the tasks are missing. We conclude, therefore, that social resilience is indeed robust. This does not, however, preclude worker flexibility in response to changes in task supply and demand. We propose a possible sorting mechanism based on worker mobility levels which might explain the robustness underlying this phenomenon. Received: 25 October 1999 / Accepted: 1 April 2000     

Interdemic variation in mixed-species association patterns: common diurnal primates of Kibale National Park, Uganda

We used interdemic variation in the tendency to form mixed-species groups to examine the costs and benefits of association among the primates of Kibale National Park, Uganda. A year-long survey of six sites revealed that the amount of time that the five common diurnal primates [red colobus (Procolobus tephrosceles), black-and-white colobus (Colobus guereza), redtail monkeys (Cercopithecus ascanius), blue monkeys (Cercopithecus mitis), and grey-cheeked mangabeys (Lophocebus albigena)] spent in mixed-species groups varied dramatically among sites. In many cases, the proportion of time that species associated was positively related to their densities. By using detailed behavioral observations of redtail monkeys and red colobus made over 4 years (2660 h) at four sites, we were able to reject the null hypothesis that associations occur by chance for only one of four sites. However, a correlative approach exploring the costs and benefits of association suggests that ecological variables do influence association patterns. We found that redtail monkeys and red colobus overlapped in diet (19.2% of their foraging effort) and traveled further when in mixed-species groups than when alone. Having demonstrated this, we examined the applicability of the ecological constraints model for predicting the proportion of the time spent in mixed-species groups based on food availability. For this analysis we concentrated on red colobus from the site with 35 months of observation and demonstrated that their tendency to be in mixed- species groups was related to food availability. We used two methods to examine if mixed-species associations function to decrease predation risk. First, chimpanzees are known to prey heavily on red colobus, but rarely kill other primates. The time red colobus spent in mixed-species groups was correlated to chimpanzee density, but it was not for the other monkey species, suggesting that mixed-species groups serve to decrease predation risk. Second, when red colobus groups contain more infants and are presumably at the greatest risk of predation, they form mixed-species groups most often. These results demonstrate that the costs and benefits of mixed-species associations vary dramatically over small spatial and temporal scales. If such variation is generally the case, then studies conducted at different locations or different times could easily highlight the importance of difference selective agents in favoring mixed-species associations. Received: 10 February 1999 / Received in revised form: 16 September 1999 / Accepted: 2 October 1999     

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     

城市公交车厢内噪声监测与分析

主要对城市公交车厢内的噪声进行监测分析,用等效连续A声级和室内噪声评价指标对监测数据进行分析,评估车厢内的声音品质。结果表明,单纯用A声级不能准确反映公交车厢内的噪声污染状况,用室内噪声标准NCB曲线分析的结果与乘客的主观感受相关性良好,建议用A声级和NCB标准曲线综合考虑制定公交车厢内的噪声标准。     

Impacts of Nomad Sedentarization on Social and Ecological Systems at Multiple Scales in Xinjiang Uyghur Autonomous Region,China

China’s government is now promoting the Nomad Sedentarization Project (NSP) in large areas of grassland as a solution for ecological restoration and poverty alleviation. To examine the effects of this policy, we conducted in-depth interviews at two of the project’s sites and examined the social and ecological systems at village, county, and catchment scales in Jinghe County of Xinjiang. We found that (1) the NSP in one village greatly improved the household standard of living and changed their resource utilization modes; (2) the success in this village can be attributed to resources imported from the social and ecological systems at larger scales, and could not be repeated in a second nearby village with different constraints; and (3) the NSP is poorly adapted to local ecosystem characteristics, and may therefore have negative impacts at larger scales. To avoid these problems, holistic assessments are necessary to judge the NSP’s impacts on social and ecological systems at multiple scales, and the program must be implemented cautiously to account for the potential risks in ecologically vulnerable areas.     

Systematic analysis of corporate environmental responsibility: elements,structure, function,and principles

Corporate Environmental Responsibility (CER) is the subsystem of Corporate Social Responsibility (CSR), which continues to increase prominence in the global economy. Nowadays, CER becomes more important in corporate sustainable development. Based on Carroll’s pyramid mode of CSR, this article explores the systematic feature of CER. From a systematic perspective, it sorts out its elements, structure, function, and principles of CER. And the four levels of economic, legal, ethical, and charitable structure are emphasized. With these considerations interpreted into practice, success will be achieved in potential cost savings, technological innovation, increased public acceptance, and better relations with governments.