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201.
Lesser sandeel (Ammodytes tobianus) is abundant in near-shore areas where it is a key prey. It exhibits the behaviour of alternating between swimming in schools and lying buried in the sediment. We first determined the species’ standard metabolic rate (SMR), critical partial pressure of oxygen and maximal oxygen uptake The sandeel were then exposed to an acute stepwise decline in water oxygen pressure (18.4, 13.8, 9.8, 7.5, 5.8, 4.0, and 3.1 kPa ). Swimming speed and routine- and post-experimental blood lactate levels were measured, in addition to levels associated with strenuous exercise. The SMR was 69.0 ± 8.4 mg O2 kg−1 h−1 and the about seven times as high. The was found to be 4.1 kPa. A rapid decrease (within 1 h) in from 18.4 to 3.1 kPa had no significant effect on routine swimming speed (0.9 ± 0.06 bl s−1), but steady levels at the lowest (3.1 kPa) gradually reduced the swimming speed by 95% after 40 min. The routine blood lactate levels were 2.2 ± 0.6 mmol l−1, while the levels in the strenuously exercised groups were significantly higher with 5.4 ± 1.6 and 5.8 ± 1.3 mmol l−1. The highest levels were observed in post-experimental fish with 7.5 ± 2.7 mmol l−1. We argue that, as sandeel showed no decrease in swimming speed (to offset stress) nor an increased speed to escape the hypoxia, the fish either rely on a low SMR and being a reasonable strong oxygen regulator as a mean to cope when exposed to acute hypoxia, or that the hypoxia simply developed too fast for the fish to decide on an appropriate strategy. Not showing a behavioural response may in the present case be maladaptive, as the consequence was major physiological stress which the fish however appears tolerant towards. The high routine blood lactate levels suggest that anaerobic metabolism is associated with swimming in sandeel, which may be related to the specific lifestyle of the fish where they regularly bury in the sediment.  相似文献   
202.
Environment, Development and Sustainability - Indigenous knowledge about climate change that makes adaptability necessary by coping strategies leads to the sustainability of nomadic livelihoods....  相似文献   
203.
Objective: Although most research on drugs and driving has focused on the use of alcohol and cannabis, research that has been conducted on cigarette smoking and collisions has found that smokers have an increased collision involvement. Studies dating from 1967 through 2013 have shown a crude relative risk of about 1.5 among smokers compared to nonsmokers. In Canada, the association between smoking and collisions has not been recently investigated. Studies that have examined the association between smoking and collisions often did not control for all confounding factors, such as alcohol use and driving exposure, which have been associated with increased collision rates. Additionally, a number of these studies were examined in countries and at times when prevalence of smoking was much higher than is currently the case in Canada. The purpose of this research is to examine the association between self-reported current smoking and past-year collision involvement, controlling for confounding factors, in a large representative sample of adult drivers in Ontario, Canada, from 2002 and 2014.

Method: Data are based on the Centre for Addiction and Mental Health (CAMH) Monitor, an ongoing, rolling telephone survey of Ontario adults that provides epidemiological surveillance of indicators related to alcohol, tobacco, and other drug use, as well as physical and mental health. The survey uses random-digit-dialing methods via Computer-Assisted Telephone Interview, with response rates over 50%.

Results: Prevalence of self-reported collision involvement within the past year for 2002–2014 was 8.6% among those who currently smoke compared to 6.5% of nonsmokers. Logistic regression analysis, controlling for the potential confounding effects of sociodemographics, driving exposure measures, drinking frequency, and hazardous alcohol use, found that the overall odds for collision involvement in the preceding year among current smokers for 2002–2014 was 1.27 (95% confidence interval [CI], 1.06–1.53) times that of nonsmokers.

Conclusions: These findings indicate that despite a substantial reduction in overall prevalence of smoking in Canada, smokers still have a significantly increased odds of collision involvement, even when controlling for alcohol and exposure. Additionally, the results are consistent with the increased odds/risks of motor vehicle collisions found in other countries.  相似文献   

204.
South Africa, a main food exporter in SADC, is characterised by a dual agricultural economy consisting of a well-developed commercial sector and smallholder, often subsistence, farming. Using the Ricardian cross-sectional framework, we examine the impact of climate change on a nationwide sample of crop, horticulture, livestock and mixed commercial farming systems. We find that a simultaneous decrease in precipitation and an increase in temperature will reduce productivity; and that an increase in temperature alone negatively affects farm output more than a decrease in precipitation. One of the most robust findings is the difference in the extent to which different commercial production systems will be impacted. That is, the results indicate that the strongest impact will be amongst specialised commercial crop farming system. In contrast, mixed farming systems appear to be the least vulnerable. This finding is consistent with studies on small-holder farms in sub-Saharan Africa. Hence, it appears that despite the likely benefits derived from economies of scale, commercial farms are, somewhat, equally vulnerable to climate change. Further, a province-wise assessment revealed that areas that already face disadvantageous climatic conditions will become even less productive. Overall, the findings suggest that practicing mixed farming methods will strengthen the resilience of commercial farms to climate change and that access to extensions—insurance and irrigation—is likely to reduce the risks.  相似文献   
205.
Climate change impacts are no longer just a future issue for communities in the Mediterranean climate regions. This comparative study offers insights on climate change risk perceptions and attitudes among environmental, economic and social stakeholders in coastal areas in northeastern Spain and South Australia, as well as compares interviewed stakeholders’ risk perceptions with available documentary data and participant observation. Using a community risk assessment approach, the results show that some stakeholders perceive that climate change is already and/or may further continue to affect their employment, mostly in a predominantly negative way. Interestingly, some other interviewed stakeholders consider that climate change creates opportunities through new and additional areas of work. The findings also suggest that climate change may influence relocation of coastal residential populations in both case studies, which is likely to be an acceptable option among the stakeholders. This acceptance can be linked to the fact that in both areas there is a significant percentage of resident population with migrant background. This study calls for a need to understand better the personal experience of climate change in industrialized countries, as well as to consider coastal relocation in the integrated coastal planning and other territorial and population policies.  相似文献   
206.
Rangeland Fire Protection Associations (RFPAs) are volunteer-based groups of trained private landowners who are authorised to respond to events in partnership with governmental agencies. This study analysed the functioning and structure of RFPAs in Idaho and Oregon in the western United States to characterise this under-researched model of disaster response. RFPAs represent an expanding type of disaster response organisation that interfaces with established fire suppression entities, yet ‘emergent behaviour’ manifested in some RFPA response actions. This appeared to lessen and mediate with time, as well as due to recognition of the issues, increased experience of fires, and training that fostered new mutual understandings. There is a need for continued examination of the effect of repeat experience in developing the characteristics of disaster response organisations. In addition, it is crucial to know how the interface between established and other types of organisations may be enhanced to make cooperative disaster response more effective.  相似文献   
207.
The purpose of this study was to help to inform policy development for the Australian rangelands, and provide a proof of concept for application of a multi-criteria analysis approach to assessment of competing resource use at continental scale. The study aimed to identify and locate key natural resource and agricultural production assets in the rangelands, define a number of measures of potentially threatening processes, and use a multi-criteria approach to identify areas where threatening processes, agricultural production problems, or valuable natural resources coincided. The analysis used 35 readily available, continental spatial data layers at 5-km pixel resolution ranked from 1 (low) to 5 (high) under three themed groupings: natural resource base, production base, and threatening processes. These measures were aggregated into composite indicators to define attributes such as environmental sensitivity and total grazing pressure. The composites were then compared in a two-way analysis to explore particular interactions between threatening processes such as pastoralism and mining, and the condition of production and natural resource assets. These interactions were defined as “tensions” for purposes of this analysis. Example “tensions” included the association of high grazing intensity with areas of high environmental sensitivity, indicating a risk of land degradation under adverse climatic conditions. A summary of patterns of tension was obtained by extracting area proportions of high-tension classes for selected Natural Heritage Trust Regions, which are a basis for Australian Government funding of improved environmental management. The study provides a basis for further examination of trade-offs in the use of natural assets, opportunities for improved productivity and sustainability, and social and economic implications.  相似文献   
208.

Purpose  

Feral oilseed rape has become widespread in Europe on waysides and waste ground. Its potential as a source of GM impurity in oilseed rape harvests is quantified, for the first time, by a consistent analysis applied over a wide range of study areas in Europe.  相似文献   
209.
The aim of this work is to investigate atmospheric flow and dispersion of contaminants in the vicinity of single buildings under different stability conditions. The mathematical model used is based on the solution of equations of conservation of mass, linear momentum and energy with the use of a non-standard κ? turbulence model. The modifications proposed in the κ? model are the inclusion of the Kato and Launder correction in the production of turbulent kinetic energy and the use of a modified wall function. Results are presented of numerical simulations of dispersion around a cubical obstacle, under neutral, stable and unstable atmospheric conditions. Experimental data from wind tunnel and field trials obtained by previous authors are used to validate the numerical results. The numerical simulation results show a reasonable level of agreement with field and wind tunnel concentration data. The deviation between model results and field experimental data is of the same order as the deviation between field and wind tunnel data.  相似文献   
210.
A high-throughput screening method using selective pressurized liquid extraction (SPLE) and enzyme-linked immunosorbent assay (ELISA) for monitoring dioxins in sediment and soil is described. SPLE conditions were developed by extracting sediment or soil together with alumina, 10% AgNO3 in silica, and sulfuric acid impregnated silica (acid silica) using dichloromethane (DCM) as the solvent at 100 °C and 2000 psi. Post-extraction cleanups were not required for ELISA. Two reference sediments (National Institute of Standards and Technology SRM 1944 and Wellington Laboratories WMS01) were analyzed by the SPLE–ELISA method. The ELISA utilized a polyclonal antibody and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as the calibrant. Recoveries of ELISA-derived TCDD equivalents (EQ) relative to the expected gas chromatography/high resolution mass spectrometry (GC/HRMS) derived dioxin toxic equivalent (TEQ) values were 116 ± 11% for SRM 1944 and 102 ± 13% for WMS01. ELISA TCDD EQs were consistent with the dioxin TEQs as measured by GC/HRMS for 25 soil/sediment samples from seven different contaminated sites. The ELISA had an approximate method detection limit of 10 pg g−1 with a precision of 2.6–29% based on the relative percentage difference (%RPD) for duplicate samples. Estimated sample throughput for the SPLE–ELISA was three times or more than that of the GC/HRMS method employing PLE with a multi-column cleanup.  相似文献   
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