957 resultados para F6 - Economic Impacts of Globalization
Resumo:
Transportation accounts for 22% of greenhouse gas emissions in the UK, and increases to 25% in Northern Ireland. Surface transport carbon dioxide emissions, consisting of road and rail, are dominated by cars. Demand for mobility is rising rapidly and vehicle numbers are expected to more than double by 2050. Car manufacturers are working towards reducing their carbon footprint through improving fuel efficiency and controlling exhaust emissions. Fuel efficiency is now a key consideration of consumers purchasing a new vehicle. While measures have been taken to help to reduce pollutants, in the future, alternative technologies will have to be used in the transportation industry to achieve sustainability. There are currently many alternatives to the market leader, the internal combustion engine. These alternatives include hydrogen fuel cell vehicles and electric vehicles, a term which is widely used to cover battery electric vehicles, plug-in hybrid electric vehicles and extended-range electric vehicles. This study draws direct comparisons measuring the differing performance in terms of fuel consumption, carbon emissions and range of a typical family saloon car using different fuel types. These comparisons will then be analysed to see what effect switching from a conventionally fuelled vehicle to a range extended electric vehicle would have not only on the end user, but also the UK government.
Resumo:
Predicting the ecological impacts of damaging invasive species under relevant environmental contexts is a major challenge, for which comparative functional responses (the relationship between resource availability and consumer uptake rate) have great potential. Here, the functional responses of Gammarus pulex, an ecologically damaging invader in freshwaters in Ireland and other islands, were compared with those of a native trophic equivalent Gammarus duebeni celticus. Experiments were conducted at two dissolved oxygen concentrations (80 and 50 % saturation), representative of anthropogenic water quality changes, using two larval prey, blackfly (Simuliidae spp.) and mayfly (Baetis rhodani). Overall, G. pulex had higher Type II functional responses and hence predatory impacts than G. d. celticus and the functional responses of both predators were reduced by lowered oxygen concentration. However, this reduction was of lower magnitude for the invader as compared to the native. Further, the invader functional response at low oxygen was comparable to that of the native at high oxygen. Attack rates of the two predators were similar, with low oxygen reducing these attack rates, but this effect occurred more strongly for blackfly than mayfly prey. Handling times were significantly lower for the invader compared with the native, and significantly higher at low oxygen, however, the effect of lowered oxygen on handling times was minimal for the invader and pronounced for the native. Maximum feeding rates were significantly greater for the invader compared with the native, and significantly reduced at low oxygen, with this effect again lesser for the invader as compared to the native. The greater functional responses of the invader corroborate with its impacts on recipient macroinvertebrate communities when it replaces the native. Further, our experiments predict that the impact of the invader will be less affected than the native under altered oxygen regimes driven by anthropogenic influences.
Resumo:
Introduced browsing animals negatively impact New Zealand's indigenous ecosystems. Eradicating introduced browsers is currently unfeasible at large scales, but culling since the 1960s has successfully reduced populations to a fraction of their earlier sizes. Here we ask whether culling of ungulates has allowed populations of woody plant species to recover across New Zealand forests. Using 73 pairs of permanent fenced exclosure and unfenced control plots, we found rapid increases in sapling densities within exclosures located in disturbed forests, particularly if a seedling bank was already present. Recovery was slower in thinning stands and hampered by dense fern cover. We inferred ungulate diet preference from species recovery rates inside exclosures to test whether culling increased abundance of preferred species across a national network of 574 unfenced permanent forest plots. Across this network, saplings were observed irrespective of their preference to ungulates in the 1970s, but preferred species were rarer within disturbed sites in the 1990s after long-term culling and despite nationwide increases in sapling densities. This indicates that preferred species are relatively heavily affected by browsing after culling, presumably because remaining animals will increase consumption of preferred species as competition is reduced. Our results clearly suggest that culling will not return preferred plants to the landscape immediately, even given suitable conditions for regeneration. Complete removal of ungulates rather than simply reducing their densities may be required for recovery in heavily browsed temperate forests, but since this is only feasible at small spatial scales, management efforts must target sites of high conservation value. © 2012 Elsevier Ltd.
Resumo:
Background/Question/Methods
Assessing the large scale impact of deer populations on forest structure and composition is important because of their increasing abundance in many temperate forests. Deer are invasive animals and sometimes thought to be responsible for immense damage to New Zealand’s forests. We report demographic changes taking place among 40 widespread indigenous tree species over 20 years, following a period of record deer numbers in the 1950s and a period of extensive hunting and depletion of deer populations during the 1960s and 1970s.
Results/Conclusions
Across a network of 578 plots there was an overall 13% reduction in sapling density of our study species with most remaining constant and a few declining dramatically. The effect of suppressed recruitment when deer populations were high was evident in the small tree size class (30 – 80 mm dbh). Stem density decreased by 15% and species with the greatest annual decreases in small tree density were those which have the highest rates of sapling recovery in exclosures indicating that deer were responsible. Densities of large canopy trees have remained relatively stable. There were imbalances between mortality and recruitment rates for 23 of the 40 species, 7 increasing and 16 in decline. These changes were again linked with sapling recovery in exclosures; species which recovered most rapidly following deer exclusion had the greatest net recruitment deficit across the wider landscape, indicating recruitment suppression by deer as opposed to mortality induced by disturbance and other herbivores. Species are not declining uniformly across all populations and no species are in decline across their entire range. Therefore we predict that with continued deer presence some forests will undergo compositional changes but that none of the species tested will become nationally extinct.
Impacts of invasive browsers on demographic rates and forest structure in New Zealand. Available from: http://www.researchgate.net/publication/267285500_Impacts_of_invasive_browsers_on_demographic_rates_and_forest_structure_in_New_Zealand [accessed Oct 9, 2015].
Resumo:
Milk in its natural form has a high food value, since it is comprised of a wide variety of nutrients which are essential for proper growth and maintenance of the human body. In recent decades, there has been an upsurge in milk consumption worldwide, especially in developing countries, and it is now forming a significant part of the diet for a high proportion of the global population. As a result of the increased demand, in addition to the growth in competition in the dairy market and the increasing complexity of the supply chain, some unscrupulous producers are indulging in milk fraud. This malpractice has become a common problem in the developing countries, which lack strict vigilance by food safety authorities. Milk is often subjected to fraud (by means of adulteration) for financial gain, but it can also be adulterated due to ill-informed attempts to improve hygiene conditions. Water is the most common adulterant used, which decreases the nutritional value of milk. If the water is contaminated, for example, with chemicals or pathogens, this poses a serious health risk for consumers. To the diluted milk, inferior cheaper materials may be added such as reconstituted milk powder, urea, and cane sugar, even more hazardous chemicals including melamine, formalin, caustic soda, and detergents. These additions have the potential to cause serious health-related problems. This review aims to investigate the impacts of milk fraud on nutrition and food safety, and it points out the potential adverse human health effects associated with the consumption of adulterated milk.
Resumo:
Purpose
The Strengths and Difficulties Questionnaire (SDQ) is a behavioural screening tool for children. The SDQ is increasingly used as the primary outcome measure in population health interventions involving children, but it is not preference based; therefore, its role in allocative economic evaluation is limited. The Child Health Utility 9D (CHU9D) is a generic preference-based health-related quality of-life measure. This study investigates the applicability of the SDQ outcome measure for use in economic evaluations and examines its relationship with the CHU9D by testing previously published mapping algorithms. The aim of the paper is to explore the feasibility of using the SDQ within economic evaluations of school-based population health interventions.
Methods
Data were available from children participating in a cluster randomised controlled trial of the school-based roots of empathy programme in Northern Ireland. Utility was calculated using the original and alternative CHU9D tariffs along with two SDQ mapping algorithms. t tests were performed for pairwise differences in utility values from the preference-based tariffs and mapping algorithms.
Results
Mean (standard deviation) SDQ total difficulties and prosocial scores were 12 (3.2) and 8.3 (2.1). Utility values obtained from the original tariff, alternative tariff, and mapping algorithms using five and three SDQ subscales were 0.84 (0.11), 0.80 (0.13), 0.84 (0.05), and 0.83 (0.04), respectively. Each method for calculating utility produced statistically significantly different values except the original tariff and five SDQ subscale algorithm.
Conclusion
Initial evidence suggests the SDQ and CHU9D are related in some of their measurement properties. The mapping algorithm using five SDQ subscales was found to be optimal in predicting mean child health utility. Future research valuing changes in the SDQ scores would contribute to this research.
Resumo:
Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in “100 of the World's Worst Invasive Alien Species”; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest “attack rates” a, shortest “handling times” h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach.