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261.
本文主要介绍俄罗斯远东地区的森林破坏现状和木材贸易的情况。以期让更多的人士了解和关心俄罗斯的森林生态环境。  相似文献   
262.
Human security, particularly in the Arctic, is being stressed by climate change and other factors. Science and technology provide one instrument for the development of strategies that will protect those living in the Arctic from threats to environmental, social and economic conditions, namely human security, incurred by climate change. This paper explores a public good approach to Canada’s Science and Technology (S&T) strategy. Investigated in particular is the role of science and technology in addressing Arctic human security needs, using evolving Organisation for Economic Co-operation and Development (OECD) quality-of-life indicators to measure the ability of Canada’s S&T strategy to meet these needs.  相似文献   
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264.
Measurements have been made of oxygen consumption rates O2 of 10 specimens of the mesopelagic deep-sea fangtooth fish Anoplogaster cornuta. Determinations were made at 1 atm pressure, at temperatures of 3°, 7°, and 10°C, at dissolved oxygen concentrations ranging from near saturation to zero, with the fish swimming at low, controlled speeds. Weight-specific O2 were uniformly low. They showed Q10's of 2.5 and 1.3, respectively, in the temperature ranges 3° to 7°C, and 7° to 10°C, at dissolved oxygen concentrations above 2 ml (standard temperature and presusure, STP)/1. Measurable O2 continued in these fish at dissolved oxygen concentrations down to the lowest levels detectable with our instruments. At 7°C the average critical oxygen tension (P c ) for the entire group was near 35 mm Hg. However, there is a statistically significant positive slope to the regression line relating O2 to P c for individual fish. The physiological and ecological significance of these results is discussed, particularly with reference to thermal effects and to the basis for survival by A. cornuta in the oxygen minimum layers of the eastern Pacific Ocean.  相似文献   
265.
Recent perspectives on public responses to environmental and risk communication have emphasised the interpretation, judgement and 'sense-making' that takes place when lay audiences receive information and advice. In this paper we consider the public reception given to air-quality information in the UK as one example of a government information and communication initiative. Drawing on elements of a wider research project undertaken in the city of Birmingham in the UK, involving a survey and in-depth interviews with members of the public, it examines the extent of awareness and use of information services, attitudes towards information and the role of information in behaviour change. The objective of the paper is to assess in practical terms the impact of air-quality information available through the media and other sources, as well as to provide empirical evidence with which to reflect on debates over the practice of environmental communication and the stimulation of pro-environmental behaviour. Conclusions are drawn which point to both problems with air quality information provision and the possibilities of more effective and appropriate interventions through local-level initiatives.  相似文献   
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267.
This paper describes an individual-based stochastic model of eastern king prawn migration along the eastern Australian coast. Migration is treated as one-dimensional diffusion with drift. Capture of a prawn is seen as a failure event driven by movement through a spatially and temporally variable fishing mortality hazard. This hazard is combined with a uniform natural mortality hazard. We use a Monte Carlo method to estimate parameters by comparing expected numbers of tag-returns predicted from the model with previously published tag-release data. As the previous study used a discrete compartmental model, with compartments corresponding to zones of constant fishing effort, we used the same zones and fishing effort in our comparison. The marginal distribution of yield in each zone per single recruit is determined, providing more information compared with the deterministic approach to yield-per-recruit. Using our model we also derive the constant fishing mortality rate equivalent to a spatially variable fishing mortality rate in its impact on the proportion of prawns surviving the migration to reach spawning grounds. Determination of this proportion could contribute significantly to a sustainability assessment of the fishery. It is demonstrated using the AIC that better fits to the data of the previous study and greater parsimony are obtained using our model than were found in the deterministic compartmental analysis of that study. This improvement results from the ability of our model to account separately for average speed of movement and average dispersal rate, whereas in the previous deterministic compartmental model, movement is governed by just one parameter. Our individual-based model includes a parameter that explicitly accounts for dispersal of prawns in migration, so it can distinguish between speed effects and dispersal effects in the data. It also models both types of mortality as processes distinct from those of movement. This enables it to better separate movement and mortality effects compared to the compartmental approach, in which movement and mortality are treated as similar departure processes from a compartment. This separation reduces confounding of movement and mortality effects when parameters are estimated.  相似文献   
268.
It is well documented that micronutrient malnutrition is of increasing concern in the developing world, resulting in poor health and high rates of mortality and morbidity. During pregnancy, deficiency of iron and zinc can produce cognitive and growth impairment of the foetus, which may continue into infancy. Iron and zinc are essential micronutrients for both plant growth and human nutrition. Despite significant work in the areas of soil fertility, crop biofortification and dietary interventions, the problems of micronutrient deficiencies persist in Africa. There is a need to examine why communities have not embraced intervention strategies which may offer health benefits. Bottom-up, interdisciplinary approaches are required to effectively study the relationships between local communities and their environment, and to assess the impact their behaviour has on the cycling of micronutrients within the soil–plant–human system. From a detailed consideration of diverse influencing factors, a methodological model is suggested for studying the barriers to improving micronutrient uptake within rural communities. It combines environmental understanding with health and social factors, emphasising the need for and potential benefits of understanding and coherence in true interdisciplinary working.  相似文献   
269.
Multimodal signals may compensate for environmental constraints on communication, as signals in different modalities vary in efficacy. We examined the influence of complex microhabitats on transmission of vibratory and visual signals of courting male Schizocosa ocreata wolf spiders (Araneae: Lycosidae) with laser Doppler vibrometry (LDV) and behavioral observations in lab and field. We measured maximum potential detection distance of visual and vibratory signals by females in laboratory mesocosms, recorded vibration signal attenuation on different substrates, and estimated transmission distances for male vibration signals in the field. We also determined effective line-of-sight visual detection distances in the field with laser distance measures. Together, these data were used to estimate the potential and effective active space of multimodal signals. LDV measures show leaves are highly conductive substrates for wolf spider vibratory signals compared to others (soil, wood, rock). For both visual and vibratory modes, lab estimates of maximum potential distance for signal transmission and detection (behavior studies) exceeded estimates of effective active space (signal attenuation, “vanishing point,” and “line-of-sight” measures). Field estimates of transmission distance for signal modes overlap, such that in close range (<20 cm), vibratory signals are more likely to be detected, while farther away, visual signals are more likely to be seen. These findings thus support current hypotheses regarding how multimodal communication might extend the range of overall signal active space or compensate for environmental constraints.  相似文献   
270.
The terrorist attacks of 11 September 2001 (9/11) left workplaces in pressing need of a mental health response capability. Unaddressed emotional sequelae may be devastating to the productivity and economic stability of a company's workforce. In the second year after the attacks, 85 employees of five highly affected agencies participated in 12 focus groups to discuss workplace mental health issues. Managers felt ill prepared to manage the magnitude and the intensity of employees' emotional responses. Rapid return to work, provision of workplace mental health services, and peer support were viewed as contributory to emotional recovery. Formal mental health services provided were perceived as insufficient. Drawing on their post‐9/11 workplace experience, members of these groups identified practical measures that they found helpful in promoting healing outside of professional mental health services. These measures, consistent with many principles of psychological first aid, may be applied by workplace leaders who are not mental health professionals.  相似文献   
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