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Media and academic debates about the environment have increasingly made reference to the so-called 'eco-preneur' ('green entrepreneur' or 'environmental entrepreneur'). These discussions encourage us to see the potential of such figures to act as drivers of environmental innovation. Their combination of entrepreneurial zeal and green motivations is seen as providing them with the ability to transcend the usual tensions between business and the environment. In academic circles a new literature is beginning to emerge around this perspective, 'eco-preneurship'. In this paper we investigate the usefulness of eco-preneurship for understanding environmental innovation. In particular we ask where this literature, supported by popular images in the media, fixes our gaze when we think about environmental innovation in society. And, crucially, what might we be missing by concentrating our attention on these eco-preneurs? The paper concludes by suggesting that environmental innovation is better understood as an inherently messy and complex institutional process, which cannot be reduced to the psychology of entrepreneurial personalities. 相似文献
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A quantitative PCR(q PCR) assay was used to quantify Ancylostoma caninum ova in wastewater and sludge samples.We estimated the average gene copy numbers for a single ovum using a mixed population of ova.The average gene copy numbers derived from the mixed population were used to estimate numbers of hookworm ova in A.caninum seeded and unseeded wastewater and sludge samples.The newly developed qP CR assay estimated an average of3.7 × 10~3 gene copies per ovum,which was then validated by seeding known numbers of hookworm ova into treated wastewater.The qP CR estimated an average of(1.1 ± 0.1),(8.6 ± 2.9)and(67.3 ± 10.4) ova for treated wastewater that was seeded with(1 ± 0),(10 ± 2) and(100 ± 21)ova,respectively.The further application of the q PCR assay for the quantification of A.caninum ova was determined by seeding a known numbers of ova into the wastewater matrices.The qP CR results indicated that 50%,90% and 67% of treated wastewater(1 L),raw wastewater(1 L)and sludge(~4 g) samples had variable numbers of A.caninum gene copies.After conversion of the q PCR estimated gene copy numbers to ova for treated wastewater,raw wastewater,and sludge samples,had an average of 0.02,1.24 and 67 ova,respectively.The result of this study indicated that qP CR can be used for the quantification of hookworm ova from wastewater and sludge samples;however,caution is advised in interpreting qP CR generated data for health risk assessment. 相似文献
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Coupled cycles of dissolved oxygen and nitrous oxide in rivers along a trophic gradient in southern Ontario, Canada 总被引:1,自引:0,他引:1
Diel (24-h) cycling of dissolved O2 (DO) in rivers is well documented, but evidence for coupled diel changes in DO and nitrogen cycling has only been demonstrated in hypereutrophic systems where DO approaches zero at night. Here, we show diel changes in N2O and DO concentration at several sites across a trophic gradient. Nitrous oxide concentration increased at night at all but one site in spring and summer, even when gas exchange was rapid and minimum water column DO was well above hypoxic conditions. Diel N2O curves were not mirror images of DO curves and were not symmetrical about the mean. Although inter- and intrasite variation was high, N2O peaked around the time of lowest DO at most of the sites. These results suggest that N2O must be measured several times per diel period to characterize curve shape and timing. Nitrous oxide concentration was not significantly correlated with NO3- concentration, contrary to studies in agricultural streams and to the current United Nations Intergovernmental Panel for Climate Change protocols for N2O emission estimation. The strong negative correlation between N2O concentration and daily minimum DO concentration suggested that N2O production was limited by DO. This is consistent with N2O produced by nitrite reduction. The ubiquity of diel N2O cycling suggests that most DO and N2O sampling strategies used in rivers are insufficient to capture natural variability. Ecosystem-level effects of microbial processes, such as denitrification, are sensitive to small changes in redox conditions in the water column even in low-nutrient oxic rivers, suggesting diel cycling of redox-sensitive compounds may exist in many aquatic systems. 相似文献
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Luciana Möller Fernanda Pedone Valdez Simon Allen Kerstin Bilgmann Shannon Corrigan Luciano B. Beheregaray 《Marine Biology》2011,158(1):113-126
Oceanographic processes play a significant role in shaping the genetic structure of marine populations, but it is less clear
whether they affect genetic differentiation of highly mobile vertebrates. We used microsatellite markers and mtDNA control
region sequences to investigate the spatial genetic structure of short-beaked common dolphins (Delphinus delphis) in southeastern Australia, a region characterised by complex oceanographic conditions associated with the East Australian
Current (EAC). A total of 115 biopsy samples of dolphins were collected from six localities spanning approximately 1,000 km
of the New South Wales (NSW) coastline. We found evidence for contrasting genetic diversity and fine-scale genetic structure,
characterised by three genetically differentiated populations with varying levels of admixture. Spatial genetic structure
was not explained by a model of isolation by distance, instead it coincides with main patterns of oceanographic variation
along the EAC. We propose that common dolphins along the EAC may be adapted to three water masses recently characterised in
this region. 相似文献