The role of cognitive maps in spatial decisions

The traveling salesman's problem, in which one decides which order between n locations minimizes total travel distance, was used as a laboratory analogue of spatial decisions in large-scale environments. In an experiment in which university students were observed while solving this problem, a group who received numerical information about distances between locations was found to minimize local distances rather than total distance, that is, to choose first the closest location from the starting location, then the closest location from that chosen, and so forth. However, if a picture of the locations was presented, total distance was minimized more frequently than local distances, presumably because subjects changed their decisions which minimized local distances when they discovered spatial patterns indicating that a shorter path existed. It was also found that a picture did not always have to be presented because subjects mentally constructed a functionally equivalent spatial representation from pieces of direction and distance or only direction information. This finding was even clearer when subjects were allowed to draw pictures of the locations.     

可持续力的制度框架:俄罗斯和波罗的海国家林业部门的比较分析

苏维埃体系解体之后,原苏维埃共和国之间森林管理的分歧变得明显.在波罗的海国家的林业部门已经发生根本变化的时候,俄罗斯却没能形成一个能适应社会-生态恢复力先决条件的制度框架.本文认为,可持续发展需要一种能够具有适应和学习能力,因而能够以实验的方式对政策不断地进行评估和再调整的制度框架.但是,这需要有参与机制,我们相信波罗的海国家在这方面正在走出一条更有希望的路子.最后,得出结论,只有建立了可持续的制度框架,社会-生态恢复力才能成为前共产主义国家自然资源管理的重要特征.     

Memory for the spatial layout of the everyday physical environment: Factors affecting rate of acquisition

That a memory representation of the spatial layout of a large-scale environment may be acquired very fast was shown in two experiments in which subjects (48 undergraduates and high-school students) were taken on tours through a residential area with which they were unfamiliar. Memory for the path traversed was almost perfect after the first trial, as indicated by almost perfect recall of the order in which a number of designated landmarks had been passed. Memory for the locations of the same landmarks appeared to reach an asymptotic level after the second of three trials. The memory representation of the locations were however not perfectly accurate, thus the asymptotic level might have been an acquisition plateau. The rate of acquisition was slightly faster for subjects driven in a car slowly through the area than for those who walked the same path. Men tended to improve slightly faster than women if they were driven by car but there were no other sex differences. Finally, the acquired memory representation appeared to be resistant to forgetting. Re-learning after a one-week retention interval was faster and rate of learning was not negatively affected whether the trials were massed or distributed with one week in between. The results are discussed in terms of hypotheses concerning the order in which different types of information about spatial layouts (landmarks, paths, and locations) are acquired. The bearing of the results on the question of why memory representations of the spatial layout are often found to be distorted is also discussed.     

CURRENT USE OF WATER SURFACE ZONING FOR RECREATION1

ABSTRACT: As the many recreational uses of waterways have intensified, management agencies have increasingly turned to water surface zoning techniques to provide safe, equitable opportunities while also protecting aquatic habitats. Other publications have described the concept of water surface zoning; the study reported on was conducted to determine its current use nationwide. Depending on jurisdiction of the water surface in question and state legislation to zone water surfaces, nonfederal zoning regulations sometimes emanate directly from state government, and sometimes involve direct state and local government cooperation. Results of a national survey show that water surface zoning techniques employed by state and local governments in 1976–77 fall into five broad categories: restrictions on boat speed and horsepower, special use zoning, time zoining, protective space zoning, and limited density zoning. Examples of each are reported on in this paper.     

Phosphorus removal from livestock effluents: recent technologies and new perspectives on low-cost strategies

Environmental Science and Pollution Research - Phosphorus is an essential element in the food production chain, even though it is a non-renewable and limited natural resource, which is going to run...     

Chemical and microbiological hazards associated with recycling of anaerobic digested residue intended for agricultural use

In the present study, three full-scale biogas plants (BGP) were investigated for the concentration of heavy metals, organic pollutants, pesticides and the pathogenic bacteria Bacillus cereus and Escherichia coli in the anaerobically digested residues (ADR). The BGPs mainly utilize source-separated organic wastes and industrial food waste as energy sources and separate the ADR into an ADR-liquid and an ADR-solid fraction by centrifugation at the BGP. According to the Norwegian standard for organic fertilizers, the ADR were classified as quality 1 mainly because of high zinc (132-422 mg kg(-1) DM) and copper (23-93 mg kg(-1) DM) concentrations, but also because of high cadmium (0.21-0.60 mg kg(-1) DM) concentrations in the liquid-ADR. In the screening of organic pollutants, only DEHP (9.7-62.1 mg kg(-1)) and ∑ PAH 16 (0.2-1.98 mg kg(-1) DM) were detected in high concentrations according to international regulations. Of the 250 pesticides analyzed, 11 were detected, but only imazalil (<0.30-5.77 mg kg(-1) DM) and thiabendazol (<0.14-0.73 mg kg(-1) DM) were frequently detected in the ADR-fiber. Concentrations of imazalil and thiabendazol were highest during the winter months, due to a high consumption of citrus fruits in Norway in this period. Ten percent of the ADR-liquid samples contained cereulide-producing B. cereus, whereas no verotoxigenic E. coli was detected. The authors conclude that the risk of chemical and bacterial contamination of the food chain or the environment from agricultural use of ADR seems low.     

Policy design for a multifunctional landscape

Landscapes consisting of several elements, such as wetlands and forests, are multifunctional in nature and produce both market and non-market goods. The need for policies arises from the existence of non-market ecosystem services that are not traded and thereby generally not subject to economic trade-offs in landowner decision making. An efficient incentive scheme for producing both types of goods would require policy designed for each non-market good. However, this may result in high transaction costs, possibly giving second-best solutions a comparative advantage when only one non-market good is regulated. This paper demonstrates that in the Hovran catchment area in mid Sweden, which produces the non-market goods water quality, biodiversity, and scenic beauty, compensation payments for biodiversity production alone provide almost maximum total net value of all market and non-market goods. On the other hand, payments for providing scenic beauty in the form of open landscape may result in lower total net value than no compensation payment at all, due to a negative impact on water quality.