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81.
Cardiovascular disease has severe consequences for both individual betterment and organizational health. Yet, organization‐based cardiovascular research remains quite limited. This commentary addresses this void by integrating research dating from the famous Hawthorne experiments with current medical science. It then suggests future organizational research on cardiovascular health and recommends use of specific composite cardiovascular measures to advance our understanding of the organizational implications of cardiovascular disease. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
82.
83.
Amino acids constitute one of the largest inputs of organic nitrogen (N) to most polar soils and have been hypothesized to be important in regulating vegetational succession and productivity in Arctic ecosystems. Our understanding of amino acid cycling in these soils, however, is poor. The aim of this study was to investigate the size and rate of turnover of the amino acid pool in a range of Arctic and Antarctic soils. Our results indicate that in polar soils with either high or low ornithogenic inputs the amino acid pool is small in comparison to the inorganic N pool (NO3 and NH+4). The free amino acid pool constituted only a small proportion of the total dissolved organic nitrogen (DON) pool in these soils. Here we show that these low concentrations may be due to rapid use by the soil microbial community in both Arctic and Antarctic soils. The turnover of the amino acid pool in soil was extremely rapid, with a half-life ranging from 2 to 24 h, indicating that this N pool can be turned over many hundred times each summer when polar soils are frequently unfrozen. The implications of amino acids in N cycling and plant and microbial nutrition are discussed.  相似文献   
84.
Impact of Land Use on Soluble Organic Nitrogen in Soil   总被引:5,自引:0,他引:5  
Although it has been hypothesized that soluble organic nitrogen (SON) plays a central role in regulating productivity in some terrestrial ecosystems, the factors controlling the size of the SON pool in soil remain poorly understood. Therefore our principal aim in this work was to assess the impact of seven different land use systems (rough and managed grassland, deciduous and coniferous woodland, heathland, wetland and tilled land) on the size of the SON and inorganic N (NO 3 , NH 4 + ) pools in the surface soil layer (0–15 cm). After extraction with deionised water, we found that in most cases the size of the water extractable organic N (WEON) pool was similar in size to the inorganic N pool. In contrast, the KCl extractable organic N (KClEON) pool constituted the dominant form of soluble N in soils under all land uses, perhaps indicating that significant amounts were held on the soil exchange phase. In contrast to inorganic N, which varied significantly with land use, the size of the KClEON and WEON pool was similar for all land uses with the exception of KClEON in tilled land, where significantly lower amounts were observed. We conclude that SON constitutes an important soil N pool in a broad range of land uses, and that its role in microbial N assimilation, plant nutrition and ecosystem responses to atmospheric N deposition warrants further attention. SAFRD, University of Newcastle, Newcastle-upon-Tyne, NE1 7RU, U.K.  相似文献   
85.
86.
This paper presents the story of a project undertaken by researchers who are active participants in the national Australian debate over place and belonging. It arose from the desire to ground this debate, which brings issues of ecological sustainability, reconciliation and multiculturalism together, in more localised action aimed at building a 'place-responsive society'. The project was carried out as a case study in a region that combines part of the Sydney metropolitan area and the separate 'city' of the Blue Mountains, and involved a consultative committee and then a regional forum of conservationists, environmental educators and community workers. The researchers explored existing place-oriented initiatives in the region and developed practical projects for the future, most notably a proposal for 'totemic species' work within schools involving local Aboriginal people. The research demonstrated, more than anything else, that indigenous Australian approaches to 'place awareness' and nature conservation remain highly relevant in contemporary Australia. It also showed that bioregional awareness and the notion of place responsiveness can add value to more traditional approaches to nature conservation and environmental education. There are opportunities to galvanise local action that can integrate community and environmental work and revitalise professional practice in both areas, but the effort involves working constantly with difference and conflict.  相似文献   
87.
88.
Amino acids constitute one of the largest inputs of organic nitrogen (N) to most polar soils and have been hypothesized to be important in regulating vegetational succession and productivity in Arctic ecosystems. Our understanding of amino acid cycling in these soils, however, is poor. The aim of this study was to investigate the size and rate of turnover of the amino acid pool in a range of Arctic and Antarctic soils. Our results indicate that in polar soils with either high or low ornithogenic inputs the amino acid pool is small in comparison to the inorganic N pool (NO? 3 and NH+ 4). The free amino acid pool constituted only a small proportion of the total dissolved organic nitrogen (DON) pool in these soils. Here we show that these low concentrations may be due to rapid use by the soil microbial community in both Arctic and Antarctic soils. The turnover of the amino acid pool in soil was extremely rapid, with a half-life ranging from 2 to 24 h, indicating that this N pool can be turned over many hundred times each summer when polar soils are frequently unfrozen. The implications of amino acids in N cycling and plant and microbial nutrition are discussed.  相似文献   
89.
Hot Spots of Perforated Forest in the Eastern United States   总被引:1,自引:0,他引:1  
National assessments of forest fragmentation satisfy international biodiversity conventions, but they do not identify specific places where ecological impacts are likely. In this article, we identify geographic concentrations (hot spots) of forest located near holes in otherwise intact forest canopies (perforated forest) in the eastern United States, and we describe the proximate causes in terms of the nonforest land-cover types contained in those hot spots. Perforated forest, defined as a 0.09-ha unit of forest that is located at the center of a 7.29-ha neighborhood containing 60–99% forest with relatively low connectivity, was mapped over the eastern United States by using land-cover maps with roads superimposed. Statistically significant (P < 0.001) hot spots of high perforation rate (perforated area per unit area of forest) were then located by using a spatial scan statistic. Hot spots were widely distributed and covered 20.4% of the total area of the 10 ecological provinces examined, but 50.1% of the total hot-spot area was concentrated in only two provinces. In the central part of the study area, more than 90% of the forest edge in hot spots was attributed to anthropogenic land-cover types, whereas in the northern and southern parts it was more often associated with seminatural land cover such as herbaceous wetlands.  相似文献   
90.
Despite the critical role of government agencies in decentralizing natural resource governance, little work to date has focused on the organizational aspects of the responsible government bureaucracies. Based on a qualitative investigation of the perspectives of Forest Department employees involved in India's Joint Forest Management (JFM) program, this paper aims to provide an understanding of these internal dynamics. Elaborating on why bureaucracies with a learning orientation are essential if participatory natural resource management is to succeed, the paper underlines the constraints to transforming forest agencies' hierarchical work cultures. Foresters describe JFM as a radical departure from traditional forest governance, but suggest that corresponding transformation within the Forest Department has not occurred. Foresters cite as reasons: (1) a target-based incentive system that leaves little room for establishing the relationships with local people needed for collaborative management; (2) rigid rules and regulations that prevent the flexibility needed for adaptive, site-specific problem-solving; (3) a hierarchical, top-down style of communication that prevents the upper administration from learning what is happening on the ground and stifles initiative by field staff; (4) the need for a committed leadership to reverse this hierarchical culture. They point to the few such team-oriented leaders as the key to transforming the Forest Department and enabling participatory forest management to succeed. The authors also recommend accompanying changes in training and reward systems.  相似文献   
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