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Sustained cultivation of Bacillus thuringiensis (Bt) transgenic crops requires stable transgene expression under variable abiotic conditions. We studied the interactions of Bt toxin production and chronic ozone exposure in Bt cry1Ac-transgenic oilseed rape and found that the insect resistance trait is robust under ozone elevations. Bt Cry1Ac concentrations were higher in the leaves of Bt oilseed rape grown under elevated ozone compared to control treatment, measured either per leaf fresh weight or per total soluble protein of leaves. The mean relative growth rate of a Bt target herbivore, Plutella xylostella L. larvae was negative on Bt plants in all ozone treatments. On the non-transgenic plants, larval feeding damage was reduced under elevated ozone. Our results indicate the need for monitoring fluctuations in Bt toxin concentrations to reveal the potential of ozone exposure for altering dosing of Bt proteins to target and non-target herbivores in field environments experiencing increasing ozone pollution.  相似文献   
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The ‘Perfect Storm’ metaphor describes a combination of events that causes a surprising or dramatic impact. It lends an evolutionary perspective to how social-ecological interactions change. Thus, we argue that an improved understanding of how social-ecological systems have evolved up to the present is necessary for the modelling, understanding and anticipation of current and future social-ecological systems. Here we consider the implications of an evolutionary perspective for designing research approaches. One desirable approach is the creation of multi-decadal records produced by integrating palaeoenvironmental, instrument and documentary sources at multiple spatial scales. We also consider the potential for improved analytical and modelling approaches by developing system dynamical, cellular and agent-based models, observing complex behaviour in social-ecological systems against which to test systems dynamical theory, and drawing better lessons from history. Alongside these is the need to find more appropriate ways to communicate complex systems, risk and uncertainty to the public and to policy-makers.  相似文献   
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The COVID-19 pandemic has highlighted weaknesses in global food systems, as well as opening windows of opportunity for innovation and transformation. While the nature and extent of this crisis is rare, extreme climatic events will increase in magnitude and frequency, threatening similar societal impacts. It is therefore critical to identify mechanisms for developing food systems that are resilient to such impacts. We examine impacts of the crisis on UK food systems and how these further entrenched social inequalities. We present data on the experiences and actions of producers, consumers, and community organisers. The data were collected by adapting ongoing research to include surveys, interviews and online workshops focused on the pandemic. Actors’ responses to the pandemic foreshadow how enduring change to food systems can be achieved. We identify support required to enable these transformations and argue that it is vital that these opportunities are embedded in food justice principles which promote people-centred approaches to avoid exacerbating injustices prevalent pre-crisis. Learning from these experiences therefore provides insights for how to make food systems elsewhere more resilient and just.  相似文献   
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Trio exome sequencing was performed on a fetus presenting with severe hydrops fetalis at 21 + 0 weeks gestation. A novel de novo BICD2 missense variant was identified in the fetus. Pathogenic variants in the BICD2 gene are associated with lower extremity-predominant spinal muscular atrophy. The variant was initially classified as a variant of uncertain clinical significance (VUS) as at the time of analysis and initial report, pathogenic variants in the BICD2 gene specifically had not been associated with fetal hydrops and no other abnormalities had been detected. It was agreed in multidisciplinary team discussions to include the variant in the report as a VUS recommending phenotypic follow-up. The pregnancy was terminated and post-mortem findings were in keeping with a BICD2-pathogenic variant. In addition, a paper was published reporting another case with a pathogenic BICD2 variant presenting with fetal hydrops. The variant classification was then upgraded to class 4 likely pathogenic and reported as consistent with the diagnosis. This case demonstrates the importance of reporting these new gene/phenotypes in enabling others in the classification of variants, staying up-to-date with literature and following up phenotype for class 3 variants of interest.  相似文献   
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The anemone Phymactis clematis exhibits intraspecific agression. An investigation into dominance relationships amongst the 3 colour morphs collected from Vna del Mar, Chile, during June, 1980, revealed them to be equally aggressive. The outcomes of experimental contests appeared to reside solely with size-dependent differences in the threshold for the release of agression. Contests were asymmetric and larger individuals displayed aggression earlier against smaller opponents, and won encounters. An analysis of times for the onset of aggression in contests showed that they were highly variable and were not a good indicator of the absolute aggressive ability of individuals as denoted by dominance rankings. It provided, however, evidence indicating a lack of assessment of opponent size during initial contact. This is discussed in relation to the evolution of aggression in anemones and to the concept of evolutionarily stable strategies in contest behaviour. It is concluded that future work on the apparent size-dependent threshold will most instructively be conducted at the neurophysiological level.  相似文献   
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A study of the sea anemone Actinia equina L. displaying red to brown column coloration was conducted on British shores in 1981 and 1982 in order to assess the ecological significance of discontinuous variation in pedal disc colour. Two ecologically distinct morphs have been revealed. One is characterised by having a red/pink pedal disc, and by being homozygous slow or heterozygous at a hexokinase locus, whilst the other has a grey/green disc and is homozygous fast. The former is relatively more common on the upper-mid shore and on vertical rock faces, whereas individuals of the latter occur more frequently at lower levels, and are relatively more abundant on horizontal surfaces. Correlated with this is a dichotomy in the strength of attachment of the disc to the substratum; anemones having red/pink discs adhere relatively more firmly. Evidence from brood size analysis suggest that the morphs are subject to differential selection; the commoner one at many site examined had a larger median brood size. At present, none of our data on gene-enzyme variation suggests that red to brown anemones in Britain comprise more than one species. Nevertheless, it is argued that local speciation is potentially likely to occur as a result of disruptive selection.  相似文献   
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Book reviews     
Factor Four: Doubling Wealth, Halving Resource Use. Ernst von Weizacker, Amory Lovins & L. Hunter Lovins, 1997, London, Earthscan, ISBN 1 85383 407 6, £15.99 (hbk)

Local and Global: Management of Cities in the Information Age,. Jordi Borja & Manuel Castells, 1997, London, Earthscan, 277pp. ISBN 1 85383 441 6, £19.95 (pbk)

Wasted: counting the costs of global consumption. Michael Redclift, 1996, Earthscan, London, 173pp. ISBN 1 85383 360 6, £32.50(hbk), 1 85383 355 X, £12.95(pbk)

Eco-feminist Natures: race, gender, feminist theory and political action. Noel Sturgeon, 1997, New York, Routledge, ISBN 0 415 912504, £12.99 (pbk)

Global Warming and Global Politics. Matthew Paterson, 1996, London and New York, Routledge, ISBN 0 415 13871 X, US$85.00, UK£50.00, (hbk) ISBN 0 415 13872 8, US$20.99, UK£12.88, (pbk)

Managing for Local Sustainability: policy, problem-solving, practice and place. Valerie M. Brown (Ed.), 1997, Commonwealth of Australia, 314 pp. ISBN 0642 26464 3, Copies of the report can be obtained from: National Office of Local Government Commonwealth Department of the Environment, Sports and Territories, GPO Box 9834, Canberra ACT 2601. Tel: (06) 289 2222; fax (06) 289 2436.

Local Agenda 21, Local Authorities and Tourism: a United Kingdom perspective. David Leslie & Fiona Muir, 1996, Glasgow, Caledonian University, ISBN 0 948255 52 8, £9.00

Straws in the Wind: medieval urban environmental law — the case of Northern Italy. Ronald E. Zupko & Robert A. Laures, 1996, Boulder, CO, Westview Press, 152 pp. ISBN 0 8133 2972 8, £10.00 (pbk)  相似文献   
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