General self‐efficacy and self‐esteem: toward theoretical and empirical distinction between correlated self‐evaluations

To test whether general self‐efficacy and self‐esteem relate differently to motivational and affective constructs, we collected data from samples in academic and work settings. Results suggest that general self‐efficacy is more highly related to motivational variables than is self‐esteem, whereas self‐esteem is more highly related to affective variables than is general self‐efficacy, as hypothesized. Furthermore, results support the notion that motivational and affective states differentially mediate the relationships of general self‐efficacy and self‐esteem with task performance. These results confirm the theoretical distinction between general self‐efficacy and self‐esteem and suggest that failure to distinguish between them might exact a price in terms of precision, validity, and understanding of determinants of performance. Implications for research and practice in organizations are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

δ<Superscript>15</Superscript>N as a natural tracer of particulate nitrogen effluents released from marine aquaculture

The flow of particulate nitrogen from marine net pen fish farm effluents to the surrounding biofouling community was quantified by means of stable isotopes of nitrogen. Plastic mesh substrates were deployed at 8 m depth near a sea bream fish farm and at a nearby reference site in the northern Gulf of Aqaba (Red Sea) to assess whether natural fouling organisms could sequester substantial quantities of farm-derived particulate nitrogen waste. A mixing equation, incorporating differences in nitrogen stable isotope composition, δ¹⁵N, between particulate organic matter (“source”) and fouling organisms (“sink”) at the fish farm and reference site, was used to estimate the amount of farm-derived nitrogen that was incorporated by the fouling community. Among the conspicuous fouling organisms examined, sponges, tunicates and polychaetes showed greatest uptake of fish farm N, where the mean fractions of farm-derived N estimated over the 2-year period of observation were 19±7, 22±6 and 31±8% of total organisms’ N content, respectively, with maximal recorded seasonal values of 68, 85 and 57%, respectively. Mean N uptake by mixed fouling communities (conspicuous + cryptic organisms) was as much as fivefold higher than that calculated for the sum of conspicuous taxa, suggesting that the retention efficiency is greater in mixed than in mono-specific biofouling communities.     

The justice perspective of job stress

The study presents a new variable, role justice, pertaining to the perceived fairness of role senders reaction when the focal individual is under conflict, ambiguity, overload, or restricted latitude. The effect of this variable on symptoms of strain was explored, with the expectation of finding either additive or interactive effects vis-à-vis the above four role stressors. Using hierarchical multiple regression, the data supported the additive model which suggested that role injustice constitutes an additional source of stress. The study was conducted with a sample of hospital nurses, known to have significant levels of job stress. The results suggest that the role stress model ought to be expanded to include social appraisal constructs because of the social origin of the stressor variables it deals with.     

Book reviews

Ecological Politics in an Age of Risk. Ulrich Beck, translated by Amos Weisz, 1995 Cambridge, Polity Press, first published Germany 1988. ISBN 0 7456 077632, hb £39.50; ISBN 0 7456 13772, pk £12.95

Environmentally Sustainable Business: a local and regional perspective. Peter Roberts, 1995, London, Paul Chapman. ISBN 1 85396 240 6, price not given

Methods of Environmental Impact Assessment. Peter Morris & Riki Therivel (Eds) 1995, London, UCL Press, 378 pp. ISBN 1 85728 117 9, hb £45.00; 1 85728 118 7, pb £14.95

A Guide to Local Environmental Auditing. Hugh Barton & Noel Bruder, 1995, London, Earthscan, 370 pp. ISBN 1 85 383 2340, pb £18.95

Household Waste Recycling. Richard Waite, 1995, London, Earthscan, ISBN 1 8538 3 2421, hb £29.95

A Seed in Time: Proceedings of the 3rd International Conference on Urban and Community Forestry. Forestry Commission, 1994. ISBN 0 885 38 328 3, £9.50 inc p&p (Copies available from: Marcus Sangster, Forestry Commission, 231 Corstorphine Road, Edinburgh EH12 7AT)

Environmental Policy in New Zealand: the politics of clean and green? Tom Buhrs & Robert Bartlett, 1993, Auckland, Oxford University Press viii + 192 pp.

Green Politics. Stephen Rainbow, 1993, Auckland, Oxford University Press xv + 106 pp.

The Future of Community Lands: human resources. E. Ndione, P. DeLeener, M. Ndiaye, P. Jacolin & J.-P. Perier, 1995, London, Intermediate Technology, 236 pp. ISBN 1 339 2480, £14.95     

Parent-offspring aggression in moorhens

Summary Colonial orb-weaving spiders from Mexico were studied to test predictions of risksensitive foraging theory: 1. group foraging increases prey capture/individual, and reduces prey variance; 2. spiders should be expected to exhibit risk-averse behavior (forage in groups) when the average level of prey exceeds individual needs, and exhibit risk-prone behavior (forage solitarily) when prey are searce. Laboratory and field studies show that group foraging increases capture efficiency and reduces variability in prey captured per spider. In desert/mesquite grassland habitat, where prey availability is low, M. atascadero forage solitarily in most cases. In tropical rainforest/agriculture sites, M. increassata forage in large colonies of thousands of webs. In intermediate habitats, M. spinipes forages solitarily or in groups, depending on prey availability. Over a range of sites with varying levels of prey, M. spinipes shifts from a risk-prone to a risk-averse group foraging strategy as prey increases.Group foraging behavior observed in colonial Metepeira fits the predictions of risk-sensitive foraging models. These findings explain why spiders tend to group webs together only in areas of superabundant prey. The role of risk-sensitivity in the evolution of coloniality in spiders is discussed.     

Science guides search and rescue after the 2006 Philippine landslide

A rockslide-debris avalanche destroyed the remote village of Guinsaugon in Southern Leyte, Philippines, on 17 February 2006. Although search and rescue procedures were implemented immediately, the scale of the landslide and a lack of information about its nature resulted in unfocused and imprecise efforts in the early days of the operation. Technical support was only introduced five days after the event, provided by a team of volunteer geologists, geophysicists, and meteorologists. By the time search and rescue operations were transferred to specific target sites, however, the chances of finding survivors trapped under the rubble had diminished. In such critical situations, speed, accuracy, and the maximum appropriation of resources are crucial. We emphasise here the need for a systematic and technically informed approach to search and rescue missions in large-scale landslide disaster contexts, and the formulation of better disaster management policies in general. Standard procedures must be developed and enforced to improve how civil authorities respond to natural calamities.     

The backward incidence of pollution control in a rigid-wage economy

The backward incidence of pollution controls onto the polluting and nonpolluting industries is examined in a two-sector, rigid-wage economy characterized by unemployment in both the short run and the long run. As expected, more restrictive pollution controls result in contraction in the polluting sector and expansion in the nonpolluting sector. Somewhat unexpectedly, national income may rise with stronger pollution controls, if the polluting industry is relatively capital intensive.     

An empirical assessment of the loose–tight leadership model: quantitative and qualitative analyses

Using questionnaire and interview data, this study attempted to find out whether the organizational loose (participative) and tight (directive) practices are compatible with or contradict each other. Using the theoretical framework of Sagie's ( 1997 ) loose–tight leadership approach, our hypotheses concerned the effects of both practices on the employee's work‐related attitudes, and the mediating role of two variables, cognitive (information sharing) and motivational (exerting effort), in these effects. Data were analysed using two methodological approaches, quantitative and qualitative. Based on a quantitative analysis of the questionnaires given to 101 professional employees of a textile company, partial support was provided for the study hypotheses. A qualitative analysis of in‐depth, semi‐structured interviews with all the employees (n = 20) in one of the company divisions led to similar conclusions. Specifically, we found that although the loose and tight practices affected work attitudes, the interviewees attributed more impact to the tight practice. In addition, none of the study variables mediated the loose impact on attitudes, whereas information sharing (but not exerting effort) mediated the influence of tight practice. Finally, the qualitative analysis revealed a deeper insight into the nature of both leader practices and their possible integration in the decision‐making processes in organizations. Copyright © 2002 John Wiley & Sons, Ltd.