Trade Linkages and Output-Multiplier Effects: A Structural VAR Approach with a Focus on Asia

This paper develops a structural VAR model to measure how a shock to one country can affect the GDP of other countries. It uses trade linkages to estimate the multiplier effects of a shock as it is transmitted through other countries' output fluctuations. The paper introduces a new specification strategy that significantly reduces the number of unknowns and allows cross-country relationships to vary over time. Then it uses this model to examine the impact of shocks to 11 Asian countries, the U.S. and the rest of the OECD. The model produces reasonably good short-term forecasts. Impulse-response matrices suggest that these multiplier effects are large and significant and can transmit shocks in very different patterns than predicted from a bilateral-trade matrix. For example, due to these output-multiplier effects, a shock to one country can have a large impact on countries that are relatively minor bilateral trading partners.

Stabilising selection in populations of drosophila

1. The work presented in this thesis is concerned with the study of stabilising selection for body size in D.melanogaster. 2. The method followed in this study was to create differences in body size through selection and observe the changes in fitness associated with these differences. Also, once the differences were created, we observed the effects of natural selection on the selected lines when selection was relaxed. 3. The consideration of this problem involves the choice of a suitable estimate of fitness as well as the definition of a suitable ecological system in which fitness should be measured. We decided that the best indicator of fitness available is the biomass produced per unit of time in competition with a standard competitor, in a live -yeast system. 4. The physiological changes responsible for the changes in body size may or may not affect fitness, tinder the conditions described. Given hypothetical differences in physiological parameters like feeding rate, efficiency of food conversion and critical size we were able to simulate in a computer the outcome of competition between strains differing in one or more of these parameters. This allowed us to make predictions of the changes in competitive ability and the productivity of the cultures. Therefore we were able to analyse our results in terms of a system rather than in terms of individual characters. 5. It was found that the physiological changes responsible for the changes in body size of the selected lines were probably changes in feeding rate associated with changes in the critical size. However, the "nature" of growth is affected in this case since we can detect differences in body size in flies exhibiting the same development time. This change in the "nature" of growth can be explained if we postulate an unbalance of growth in the selected lines. 6. Although the changes iñ body size obtained by selection are quite sùbstantial, it was difficult to detect a consistent change in compeitive ability measured against a standard competitor. It is suggested that this difficulty might be due to changes in the variance of the growth parameters correlated with changes in their mean. Within the range of deviations of body size from the unselected value these changes in variance would counteract the possible changes in fitness which are a consequence of selection. 7. Relaxation of selection for lines selected for large and small body size had little effect in bringing the mean fialue of the character back to the unselected level. One possible exception was verified when selection was relaxed in a population cage. Back selection had an immediate response, similar to that of forward selection. The experiments which tested the competitive ability of the back selected lines were not conclusive. Selection for short development time in the selected lines did not affect body size;,the changes in competitive ability were not well defined. Selection for fast and slow development had some response when development time was measured under pure culture conditions. Under competitive conditions the apparent advantage of the fast line disappeared but the disadvantage of the slow line persisted. The response to selection for fast and slow development was accompanied by a reduction in body size below the unselected level in the fast line and an increase in the slow line above the same level. 8. Selection for large and small body size under competitive conditions showed some response in both directions though less well marked than when selection was carried out under optimal conditions. 9. Inbreeding caused a proportionally equal decrease in body size in all the lines. This decrease was more accentuated when body size was measured under competitive conditions. Competitive ability was affected differentially in the 1st generation of inbreeding, but this difference disappeared subsequently. Viability was reduced below the non -inbred level. 10. The experiments on egg production of the selected and unselected flies grown under different conditions in the larval stage fed different amounts of food in the adult stage revealed a superiority of the unselected over the selected lines. 11. The crosses between the Pacific and the Kaduna populations showed no breakdown or improvement in competitive ability in the Fl or the F2, suggesting that the genes controlling the growth ability which is correlated with competitive ability are the same in the two populations

Harnessing Marine Renewable Energy from Poole Harbour: Case Study

Global warming and its impact on our environment, society, economies and security is one of the fundamental concerns of our time. In response, the United Kingdom government has put in place a legally binding target of an 80% reduction in greenhouse gas emissions on 1990 levels by 2050. The United Kingdom will need to achieve a tenfold expansion of energy supply from renewable sources by 2020 to meet its share of the European Union renewable energy target. The marine and coastal environment’s renewable energy potential in Britain is high. It is estimated that it has 50% of the tidal energy, 35% of wave and 40% of wind resources in the European Union. Use of geothermal resources using heat pump technology is the least evolved sector, but in 2010 contributed to 0.7 TWh of energy and it is believed that non domestic heat pumps could contribute up to 22 TWh by 2020. In the Southwest of England, Poole Harbour has been recognised as a potential, highly predictable source of tidal and heat energy. Local groups are embarking on a feasibility study for harnessing this energy for the benefit of the community. The purpose of this article is to examine the potential conflict of interest between the laudable aims of promoting the use of renewable energy and of safeguarding ecosystems and their biodiversity. Using Poole Harbour as a case study, it will consider the environmental and economic costs and benefits of a Community Renewable Energy project (the Poole Tidal Energy Partnership) in the context of an area subject to a number of statutory and non-statutory designations to protect nationally and internationally important habitats and species. The paper identifies key environmental legislation, including spatial planning law and policy, which will facilitate exploring whether there is potential for reconciling what may be perceived as competing objectives for sustainable development

Monitoring wild animal communities with arrays of motion sensitive camera traps

Studying animal movement and distribution is of critical importance to addressing environmental challenges including invasive species, infectious diseases, climate and land-use change. Motion sensitive camera traps offer a visual sensor to record the presence of a broad range of species providing location -specific information on movement and behavior. Modern digital camera traps that record video present new analytical opportunities, but also new data management challenges. This paper describes our experience with a terrestrial animal monitoring system at Barro Colorado Island, Panama. Our camera network captured the spatio-temporal dynamics of terrestrial bird and mammal activity at the site - data relevant to immediate science questions, and long-term conservation issues. We believe that the experience gained and lessons learned during our year long deployment and testing of the camera traps as well as the developed solutions are applicable to broader sensor network applications and are valuable for the advancement of the sensor network research. We suggest that the continued development of these hardware, software, and analytical tools, in concert, offer an exciting sensor-network solution to monitoring of animal populations which could realistically scale over larger areas and time spans

Communicating Information on Nature-Related Topics: Preferred Information Channels and Trust in Sources

How information is communicated influences the public’s environmental perceptions and behaviors. Information channels and sources both play an important role in the dissemination of information. Trust in a source is often used as a proxy for whether a particular piece of information is credible. To determine preferences for information channels and trust in various sources for information on nature-related topics, a mail-out survey was sent to randomly selected U.S. addresses (n = 1,030). Diverse groups of people may have differing communication preferences. Therefore, we explored differences in channel preferences and trust by demographics using regression models. Overall, the most preferred channels were personal experience, reading online content, and watching visual media online. The most trusted sources were science organizations, universities, and friends/family. Channel preferences varied the most by education level and age, while source trust was most influenced by education, race, age, and size of current residence (rural-urban). The influence of demographics varied depending on the individual channel and source, with some groups preferring certain channels or sources but not others. Results are useful to consider when disseminating information on nature-related topics to a general public audience. More broadly, results also suggest spreading information using different channels and sources depending on the specific audience being targeted

Validation of Alternating Kernel Mixture Method: Application to Tissue Segmentation of Cortical and Subcortical Structures

This paper describes the application of the alternating Kernel mixture (AKM) segmentation algorithm to high resolution MRI subvolumes acquired from a 1.5T scanner (hippocampus, n = 10 and prefrontal cortex, n = 9) and a 3T scanner (hippocampus, n = 10 and occipital lobe, n = 10). Segmentation of the subvolumes into cerebrospinal fluid, gray matter, and white matter tissue is validated by comparison with manual segmentation. When compared with other segmentation methods that use traditional Bayesian segmentation, AKM yields smaller errors (P < .005, exact Wilcoxon signed rank test) demonstrating the robustness and wide applicability of AKM across different structures. By generating multiple mixtures for each tissue compartment, AKM mimics the increased variation of manual segmentation in partial volumes due to the highly folded tissues. AKM's superior performance makes it useful for tissue segmentation of subcortical and cortical structures in large-scale neuroimaging studies

Clearing the Air: An Analysis of Atmospheric Protections and Pollutant Regulation in the United Kingdom Before, During, and After the EU

Air pollution is a severe issue in the United Kingdom. Legal and scientific efforts to combat the deleterious health effects arising from polluted air are wide-ranging but suffer a lack of enforcement. The issue of enforcement is a central theme within this paper; the most stringent or ambitious limits are meaningless without enforcement. Legal responses to specific pollutants and polluting industries are first explored to establish a narrative of the United Kingdom’s approach to air quality protection throughout the Industrial Revolution. Legal issues and regulatory methods during the United Kingdom’s membership of the European Union are then discussed in juxtaposition to domestic historical approaches, acknowledging the United Kingdom’s utilisation of displacement methods and general failures to adhere to European Union law. Beyond 2020, the retention and function of EU-derived and domestic legislation is considered in light of Brexit. The United Kingdom faces – post-Brexit – an opportunity for improvement in its atmospheric quality. However, without the enforcement capabilities of the Court of Justice of the European Union there is a real possibility that atmospheric quality in the United Kingdom will face a severe and dangerous regression – becoming, once again, the “dirty man of Europe”