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151.
Bacteria play important roles in plant–herbivore interactions and communicate with each other with chemical signals, often N-acylhomoserine lactones (AHL). Plant responses to these signals may influence resistance to microbial attack, but the effects of these signals on herbivore defense are unstudied. To determine whether AHL influence jasmonate (JA)-mediated herbivore resistance in Nicotiana attenuata, we treated wild-type (WT) and JA-deficient genotypes (antisense expression of NaLOX3) with N-hexanoyl-dl-homoserine lactone (C6-HSL) and measured the performance of Manduca sexta larvae. Larval mass gain on C6-HSL-treated WT plants was equivalent to that on non-treated NaLOX3-silenced plants, but significantly 4.1-fold larger than on untreated WT plants. Mass gain was unaffected by C6-HSL treatment of NaLOX3-silenced plants. Microarray analysis of the plants elicited with C6-HSL and JA inducing fatty acid–amino acid conjugates revealed a down-regulation of a proteinase inhibitor in the C6-HSL-treated WT plants. The results therefore suggest that the increased performance of M. sexta was due to direct or indirect effect of C6-HSL on JA-mediated defenses.  相似文献   
152.
Journal of Material Cycles and Waste Management - The goal of this paper was to synthesize eco-humidity-conditioned Al-MCM-41 mesoporous molecular sieves (CHCMs) from liquid–crystal-display...  相似文献   
153.
Cities, regional governments and their local utilities are taking leading roles in programmes to reduce greenhouse gas emissions. Agenda 21 highlighted the need for such local action to achieve the goals of the 1992 Earth Summit and the United Nations Framework Convention on Climate Change. This trend of increasing local action was demonstrated dramatically in Canada in 2006 when the newly elected federal government cancelled many of the previous government's climate change programmes. The EnerGuide for Houses Program illustrates the growing importance of local decisions where the federal government developed a home energy rating system that was delivered through a range of partnerships across the country. Despite all political parties voting to increase funding for the programme in 2005, the Conservative government cancelled it in May 2006. The response by provincial and local governments was immediate. Their actions revealed the ability and desire among lower-tier governments to sustain popular climate change initiatives. Both the political responses and financial implications are included in the examination of the shift in environmental responsibility from the national to the local sphere.  相似文献   
154.
155.
Predation is often considered as one of the most important biotic factor determining the success of exotic species. The freshwater amphipod Gammarus roeseli has widely colonized Western Europe, where it is frequently found in sympatry with the native species (Gammarus pulex). Previous laboratory experiments revealed that G. roeseli may have an advantage over G. pulex through differential predation by native fish (brown trout). Morphological anti-predator defences (spines) were found responsible for lower rates of predation on the invasive G. roeseli. Here, using both field surveys and laboratory experiments, we tested if a differential of predation exists with other fish predators naturally encountered by gammarids. The main predators present in our field site were nocturnal benthic feeders (mainly bullheads, Cottus gobio). Fish diet analysis showed that, compared to its global availability in the river, G. roeseli was less consumed than G. pulex. In the field, however, G. roeseli was found mainly in the aquatic vegetation whereas G. pulex was found in all habitat types. Laboratory experiments in microcosms revealed that G. roeseli was less prone to predation by C. gobio only when vegetation was present. Depending on the type of predator, the differential of predation could therefore be mediated by antipredator behaviour, and a better usage of refuges, rather than by morphological defences.  相似文献   
156.
This paper recommends a revision of watershed development policy in India in relation to the planning of development interventions involving agricultural intensification and rainwater harvesting following biophysical and societal impact studies carried out on two watershed development projects in Karnataka. A need for changes in policy has arisen in response to progressive catchments closure at the basin level and declining volumes of water flowing into village level reservoirs (known locally as tanks). Flow reductions have occurred largely as a result of increased agricultural intensification over the past 10–15 years. Field levelling, field bund construction, soil water conservation measures, farm ponds, the increase in areas under horticulture and forestry and the increased abstraction and use of groundwater for irrigation are all contributing factors to reduced flows. Planning methodologies and approaches, which may have been appropriate 20 years ago for planning water harvesting within watershed development projects, are no longer appropriate today. New planning approaches are required which (1) take account of these changed flow conditions and (2) are also able to take account of externalities, which occur when actions of some affect the livelihoods of others who have no control or influence over such activities and which (3) contribute to the maintenance of agreed minimum downstream flows for environmental and other purposes.
Ian CalderEmail:
  相似文献   
157.
Developing robust species distribution models is important as model outputs are increasingly being incorporated into conservation policy and management decisions. A largely overlooked component of model assessment and refinement is whether to include historic species occurrence data in distribution models to increase the data sample size. Data of different temporal provenance often differ in spatial accuracy and precision. We test the effect of inclusion of historic coarse-resolution occurrence data on distribution model outputs for 187 species of birds in Australian tropical savannas. Models using only recent (after 1990), fine-resolution data had significantly higher model performance scores measured with area under the receiver operating characteristic curve (AUC) than models incorporating both fine- and coarse-resolution data. The drop in AUC score is positively correlated with the total area predicted to be suitable for the species (R2 = 0.163-0.187, depending on the environmental predictors in the model), as coarser data generally leads to greater predicted areas. The remaining unexplained variation is likely to be due to the covariate errors resulting from resolution mismatch between species records and environmental predictors. We conclude that decisions regarding data use in species distribution models must be conscious of the variation in predictions that mixed-scale datasets might cause.  相似文献   
158.
The main purpose for this study is to observe the seasonal and month variations for particulates-bound mercury Hg(p) in total suspended particulates (TSP) concentration, dry deposition at five characteristic sampling sites during years of 2009-2010 in central Taiwan. The results show that the highest and lowest monthly average particulates-bound mercury Hg(p) concentrations in TSP were occurred in Dec. and Oct. at Gao-mei (wetland), Chang-hua (downtown) and He-mei (residential) sampling site. In addition, the results show that the highest and lowest monthly average particulates-bound mercury Hg(p) dry deposition was occurred in Feb. and Oct. at Quan-xing (industrial) sampling site. This study reflected that the mean highest particulates-bound mercury Hg(p) concentrations in TSP and mean highest particulates-bound mercury Hg(p) dry deposition were occurred at Gao-mei (wetland) and Quan-xing (industrial). However, the mean lowest particulates-bound mercury Hg(p) concentrations in TSP and mean lowest particulates-bound mercury Hg(p) dry deposition were also occurred at Gao-mei (wetland). Regarding seasonal variation, the order of mean-particulates-bound mercury Hg(p) concentrations in TSP in winter and spring were Gao-mei (wetland) > Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential). Finally, the order of mean-particulates-bound mercury Hg(p) dry deposition in fall, spring and summer were Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential) > Gao-mei (wetland).  相似文献   
159.

Introduction

Falls in older Australians are a significant public health issue with one in three older people falling one or more times each year.

Method

Many fall prevention randomized controlled trials have been conducted in Australia as well as across the world.

Results

The findings of these studies now constitute a substantial evidence base that can provide direction for health and lifestyle interventions for preventing falls in older people. This research evidence has contributed to health policy in Australia to some extent, but is yet to be widely implemented into practice. This opinion piece overviews previous policy initiatives and describes a new Partnership research program funded by the Australian National Health and Medical Research Council (NHMRC), which seeks to further influence health policy and address the ongoing research-practice gap.  相似文献   
160.
A passive sampler (the polar organic chemical integrative sampler; POCIS) was assessed for its ability to sample natural estrogens (17β-estradiol, E2; estrone, E1 and estriol, E3) and the synthetic estrogen (17α-ethynylestradiol, EE2) in the outlet of a sewage treatment works over several weeks. The performance of the POCIS was investigated and optimised in the laboratory before field deployment with high recoveries (66-99%) were achieved for all estrogens. Moreover, it was shown that POCIS does not exhibit any preferential selectivity towards any of the target compounds. The sampling rates of E1, E2 and E3 were 0.018 ± 0.009, 0.025 ± 0.014 and 0.033 ± 0.019 L d(-1), respectively. Following field deployments of 28 days in the discharge of a sewage works, POCIS was shown to enhance the sensitivity of estrogen detection, especially for E3, and provide time-weighted average (TWA) concentrations of E1, E2 and E3, ranging from undetectable to 12 ng L(-1) upstream of the outflow of a sewage treatment works, 13 to 91 ng L(-1) at the outflow and 8 to 39 ng L(-1) downstream of the outflow. This revealed that E1, E2 and E3 are not completely removed during sewage treatment, with concentrations most likely being maintained by contributions from conjugated estrogen analogues. Grab water samples showed considerable variation in the concentrations of estrogens over a longer period (6 months). The results confirm that POCIS is an effective and non-discriminatory method for the detection of low concentrations of estrogens in the aquatic environment.  相似文献   
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