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71.
Book reviews     
Toward Sustainable Communities: resources for citizens and their governments. Mark Roseland with Maureen Cureton & Heather Wornell, 1998, Gabriola Island, New Society Publishers, ISBN 0 86571 374 X, $18.95

First Mover Advantage by Eco-efficiency: local incentives for environment and employment.. C. Erdmunger & S. Schreckenberger, 1998, Freiburg, ICLEI, DM30

Agendas for Sustainability: environment and development into the twenty-first century. Mary Macdonald, 1998, London, Routledge, ISBN 0 415 15491X, £55.00 (hbk)

Women, Population and Global Crisis: a political-economic analysis. Asoka Bandarage, 1997, London, Zed Books, ISBN 1 85649 428 4, £15.95 (pbk)

Spirit of the Environment: religion, value, and environmental concern. David Cooper & Joy Palmer (Eds), 1998, London, Routledge, ISBN 0 4151 4202 4, £12.99 (pbk)

Environmental Transition in Nordic and Baltic Countries. Hans Aage (Ed.), 1998, (New Horizons in Environmental Economics). Cheltenham, UK and Northampton, MA, USA, Edward Elgar, ISBN 1 85898 629 X

Sustainability Indicators: measuring the immeasurable. Simon Bell & Stephen Morse, 1999, London, Earthscan Publications, 175 pp. ISBN 1 85383 498 X, LE14.95 (pbk)

The Economics of Road Transport Regulation. Erik Verhoef, Cheltenham, Edward Elgar 1996, 265 pp. ISBN 1 85898 364 9, £55.00

The Water Crisis. Julie Stauffer, London, Earthscan, 1998, ISBN 185383 436X, £12.95 (pbk)  相似文献   
72.
Nitrogen (N) is a major control on primary productivity and hence on the productivity and diversity of secondary producers and consumers. As such, ecosystem structure and function cannot be understood without a comprehensive understanding of N cycling and dynamics. This overview describes the factors that govern N distribution and dynamics and the consequences that variable N dynamics have for structure, function and thresholds of potential concern (TPCs) for management of a semiarid southern African savanna. We focus on the Kruger National Park (KNP), a relatively intact savanna, noted for its wide array of animal and plant species and a prized tourist destination. KNP’s large size ensures integrity of most ecosystem processes and much can be learned about drivers of ecosystem structure and function using this park as a baseline. Our overview shows that large scale variability in substrates exists, but do not necessarily have predictable consequences for N cycling. The impact of major drivers such as fire is complex; at a landscape scale little differences in stocks and cycling were found, though at a smaller scale changes in woody cover can lead to concomitant changes in total N. Contrasting impacts of browsers and grazers on N turnover has been recorded. Due to the complexity of this ecosystem, we conclude that it will be complicated to draw up TPCs for most transformations and pools involved with the N cycle. However, we highlight in which cases the development of TPCs will be possible.  相似文献   
73.
Levels of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in paired human adipose tissue and liver samples (n=25) from Belgium. Average concentrations and standard deviation of sum PBDEs (congeners 28, 47, 99, 100, 153, 154 and 183) were 5.3+/-3.0 (range 1.4-13.2) and 3.6+/-2.1 (range 1.0-10.0)ngg(-1) lipid weight (lw) in adipose tissue and liver, respectively. These concentrations were similar to reported PBDE data from Belgium and were at the lower end of the concentration range reported elsewhere in the world. In both tissues under study, BDE 153 and BDE 47 were the most abundant PBDE congeners, contributing approximately 35% and 25% to the total PBDE content. Average concentrations and range of PCBs (sum of 23 congeners) were 490 (range 70-1130) and 380 (range 90-1140)ngg(-1)lw in adipose tissue and liver, respectively. No correlation between age and concentrations of PBDEs could be found (r=0.04), while PCB concentrations correlated significantly with age (r=0.62, p<0.01, for the sum PCBs; r=0.64, p<0.01 for PCB 153 alone). Factors, such as exposure pathways (food, dust and air), rates of bioaccumulation, metabolism and elimination, influence the concentrations of PBDEs differently than those of PCBs in humans.  相似文献   
74.
The photolysis of caffeine was studied in solutions of fulvic acid isolated from Suwannee River, GA (SRFA) and Old Woman Creek Natural Estuarine Research Reserve, OH (OWCFA) with different chemical amendments (nitrate and iron). Caffeine degrades slowly by direct photolysis (>170 h in artificial sunlight), but we observed enhanced photodegradation in waters containing the fulvic acids. At higher initial concentrations (10 μM) the indirect photolysis of caffeine occurs predominantly through reaction with the hydroxyl radical (OH) generated by irradiated fulvic acids. Both rate constant estimates based upon measured OH steady-state concentrations and quenching studies using isopropanol corroborate the importance of this pathway. Further, OH generated by irradiated nitrate at concentrations present in wastewater effluent plays an important role as a photosensitizer even in the presence of fulvic acids, while the photo-Fenton pathway does not at neutral or higher pH. At lower initial concentrations (0.1 μM) caffeine photolysis reactions proceed even more quickly in fulvic acid solutions and are influenced by both short- and long-lived reactive species. Studies conducted under suboxic conditions suggest that an oxygen dependent long-lived radical e.g., peroxyl radicals plays an important role in the degradation of caffeine at lower initial concentration.  相似文献   
75.
This study examines perceived risk data from the U.S., China, Japan, and South Korea. These data are then compared with similar results collected from previous studies. Psychometric scaling scores from Burkino Faso (a West African Country), France, Norway, and Hungary have been analyzed and compared with results from our study. The data reveal certain risk events like nuclear weapons, war, and AIDS to have high perceived risks in all countries. These data also show that many of the events have dissimilar perceived risks in different countries. The conclusions also show some countries have higher over all levels of perceive risk (South Korea) while others like the United States display generally lower values.  相似文献   
76.
The ability of social insects to discriminate against non-nestmates is vital for maintaining colony integrity, and in most social insect species, individuals act aggressively towards non-nestmates that intrude into their nest. Our experimental field data revealed that intra-colony aggression in the primitive bulldog ant Myrmecia nigriceps is negligible; our series of bioassays revealed no significant difference in the occurrence of aggression in trials involving workers from the same, a close (less than 300 m) or a far (more than 1.5 km) nest. Further, non-nestmate intruders were able to enter the nest in 60% of our trials; a similar level was observed in trials involving nestmates. These results suggest that workers of M. nigriceps are either unable to recognize alien conspecifics or that the costs of ignoring workers from foreign colonies are sufficiently low to favor low levels of inter-colony aggression in this species.  相似文献   
77.
78.
Large-scale, long-term change initiatives take time to unfold, which can be a source of uncertainty and strain. Investigating the initial 19 months of a large-scale change, we argue that during these stages, employees' change-related beliefs become more negative over time, which negatively affects their work engagement and, ultimately, increases their turnover intentions. Furthermore, we investigate the impact of a trait, Machiavellianism, on change reactions and propose that employees high in Machiavellianism react more negatively during change processes as they are especially susceptible to uncertainty and stress. We test our (cross-level) moderated mediation model in a three-wave longitudinal study among employees undergoing a large-scale change (T1: n = 1,602; T2: n = 1,113; T3: n = 759). We find that employees' beliefs about the impact and value of the change are indeed negatively related to change duration and that decreases in these perceptions come with a decline in engagement and increases in turnover intentions. Moreover, employees high in Machiavellianism react more strongly to a deterioration in change-related beliefs, showing stronger reductions in engagement and stronger increases in turnover intentions than employees low in Machiavellianism. Our study offers explanations for the negative effects of large-scale changes including an explanatory factor for disparate employee reactions to change over time.  相似文献   
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