Lake Malawi is a great lake not only because of its size (30,800 km2) but also because of its unique fish diversity. The lake contains the highest number of freshwater fish species in the world. The fish species are hypothesized to have radiated within the lake, which is 1-2 million years old. The collapse of the capture fishery in Lake Malawi between the 1970s and 1990s led to the launch of cage culture of indigenous fish species in 2004 in the south east arm of the lake. While cage culture has been practiced for many years in temperate lakes and seas, the fish farm in Lake Malawi is the first in the African Great Lakes and, therefore, not much information currently exists that is relevant to the impact of cage culture on such a large, species-rich tropical lake. Consequently, a study was done between January and December, 2007, at the fish farm in Lake Malawi to determine potential impacts of cage wastes on the environment. The study found that, just like in temperate systems where 70-87% of C, N and P added through feed get dispersed into the environment, discharges from fish cages in Lake Malawi were between 71-88% of the nutrients added through feed. The discharges were proportional to the amount of feed added so that as production and feed supply increase over time, more cage wastes would be generated and released into the environment. The discharges were exacerbated by poor stocking and feeding regimes. Production periods were longer (mean of 376±42 days) than if recommended stocking and feeding rates were followed. Feed quality may also have affected production performance and waste generation in the cages, but was not studied. The cage wastes were incorporated into the food web and support the wild fishes in the vicinity of the fish farm. Impacts of the cage wastes on the water column and sediments in the vicinity of the cages were minimal during the study period, probably because of rapid and efficient dispersion of the wastes by strong water currents, that averaged 9.3 cm s-1, through the cages and high consumption of the cage wastes by large numbers of wild fishes which aggregated around the cages. The wild fishes also helped to disperse the cage wastes over a larger area through consumption, translocation and defecation. However, as production increases, the amount of cage wastes generated may overwhelm mitigation by dispersion by water currents and consumption by wild fishes, particularly if many cages are deployed close together and interfere with current flows. Based on my observations, a fish farm that produces 15,000 tonnes fish/yr in Lake Malawi would generate 1249, 113 and 21 megamoles/yr of C, N and P, respectively, that are comparable or higher than DOC, TDN and TDP loadings observed in the most disturbed large river systems draining into Lake Malawi. The impacts of these river systems in Lake Malawi have been well documented, particularly around river mouths and in the more densely populated and shallower southern portion of the lake, where algal communities and their sedimentation rates have begun to change. Cage culture discharges may accelerate these changes.

ID projects are characterized by a complex network of stakeholders that often lead to the tangledrelationships among various parties. Different stakeholders therefore can exert the influence overan ID project in different ways resulting in both constructive and counter-productive impacts tothe projects. The implementation stage, in many ways, is considered the most significantlyimportant phase in the project life cycle where all the project activities are materialized. Thus,understanding the intricacy of the stakeholders’ impacts to the project implementation is criticalto facilitate the project results. A multiple-case study of the two ID projects executed in Vietnam is undertaken with the aim toinvestigate the impacts of the key stakeholders on ID projects beyond the early phases of IDproject life cycle, focusing in particular on the implementation phase. In order to have the wholepicture of the key stakeholders’ impacts to the project implementation, this research alsoexplores the contributing factors of the identified impacts as well as examines how powerful thekey stakeholders are in controlling the decisions making and/or facilitating the projecti mplementation represented through their different degrees of influence. Results of the findings suggest both similarities and differences in which the reported impacts ofthe key stakeholders tend to be more counter-productive than constructive to the projectimplementation. The similarities of the findings indicate that the two distinctive projects facecommon issues in the implementation phase whilst the differences can be explained by thespecific circumstances that surround the projects. The representation of the counter-productiveaspects in the findings signify the risks associated with the key stakeholders which is worth while considering in terms of the risk mitigation in the implementation phase of an ID project.

Abstract Informationization has become the trend of global development. The information technology casts impacts on diverse aspects, including politics, economy, society, culture & all activities related to human beings. The implementation of information technology has been considered a necessary & effective strategy to meet the needs of new crime trend, combat crimes, & enhance the efficiency of the police. As far as law enforcement agents in 21st century are concerned, the obsolete crime probe mindset & the outdated equipment have not kept up with the rapid pace of crime detection in new era. Consequently, the aid of information technology becomes an indispensable part in crime detection & prevention. The police should be equipped with the knowledge of technology so that they are able to fight new trend crimes & burden the responsibility of crime detection. It is therefore imperative 1) to comprehend the current capacity & bottlenecks demonstrated by the police in crime detection, 2) to examine the introduction of information technology as a strategy to improve efficiency of the police, 3) further to prevent crimes, maintain social security, & safeguard the lives & property of citizens. This is a questionnaire-based study in which a total number of 700 hundred surveys were issued. The valid questionnaires & relevant data were collected for statistical regression analysis corresponding to each research hypothesis. The study found that there was a significantly positive relationship between information technology & efficiency of police. Information technology was divided into four factors ¡§information integration¡¨, ¡§information analysis¡¨, ¡§information exploration¡¨, & ¡§information support¡¨, while police¡¦s efficiency was categorized into ¡§the pearsonal traits of police¡¨, ¡§the behavior of police¡¦s duty, & ¡§the proficiency of police¡¨. The findings of this study showed that the implementation of information technology has cast positive impacts on the efficiency of police, & this was conducive to enhancement of crimes detection for law enforcement agents.

This dissertation investigates the dynamic economic structure transformation and its corresponding environmental consequences at the Austin-San Marcos Metropolitan Statistical Area (Austin MSA) from 1990 to 2008. Input-output (IO) analysis is the major methodology and environmental problems are defined as emissions of industrial point air pollutants. Both three-and seven-segment IO models of Austin MSA for the years of 1990, 1994, and 1999 are constructed. Direct and total pollution coefficients of six major pollutants are calculated, hypothe tical extraction measurement and structural decomposition analysis are implemented, and the quantity and pattern of pollutant emissions are simulated based on four major assumed development scenarios from 2000 to 2008. This study finds: 1) the digital economy has emerged in the Austin MSA during the 1990s, 2) the manufacturing process of Austin MSA tended to be more environmentally friendly, which supports the hypothesis of dematerialization and decarbonization, 3) consumption-driven and non-production segments related environmental problems becomes more significant in the emerging digital economy. This study predicts that industrial point air pollutant emissions will grow moderately from 2000 to 2008, assuming that the direct pollutant coefficients will change at the average rates of the 1990s and the final demand will grow at the half rates of the 1990s?? average. Pollution contribution from production segment will generally decrease and contribution from other segments such as ICT and Information will increase, however, emission contributions of the segments will vary in terms of pollutants as well as development scenarios. This study argues that the shift of the source and nature of environmental threats of in the digital economy mandates parallel reform of the current environmental policy. A new generation of policy should be cooperative rather than confrontational, integrated rather than fragmented, flexible rather than rigid. It should also facilitate innovative management initiatives to achieve sustainability. More fundamentally, it is expected to deal with environmental impacts of intangible information flows (bits) which are possibly more essential than flows of tangible goods and services (atoms) in the context of the digital economy and the information age.

Increasing demand on freeway facilities is a major challenge facing urban areas in the United States and throughout the world. Active Traffic Management (ATM) strategies can be used to increase the performance of these facilities through improved operations without the significant expenditure associated with adding capacity. One ATM strategy that has been widely deployed in the current state of practice is ramp metering, which controls the traffic demand placed on a freeway. Merge control strategies are less prevalent and largely undeveloped. This study examines the recurrently congested northbound section of Interstate Highway 35 that approaches downtown Austin, Texas. Using the VISSIM microsimulation platform, a model of this segment was developed and calibrated to reflect current peak-hour congestion. Within this model, ramp metering and merge control technologies were implemented. The impacts on traffic throughput, speed and travel time for each of these proposed systems are evaluated. / text

<p>The dynamics of impacting components is of particular interest to engineers due to concerns about noise and wear, but is particularly difficult to study due to impact's non-linear nature. To begin transferring concepts studied purely analytically to the world of physical mechanisms, four experiments are outlined, and important non-linear concepts highlighted with these systems. A linear oscillator with a kicked impact, an impacting forced pendulum, two impacting forced pendulums, and a cam follower pair are studied experimentally, with complementary numerical results.</p><p>Some important ideas highlighted are limit cycles, basins of attraction with many wells, grazing, various forms of coexistence, super-persistent chaotic transients, and liftoff. These concepts are explored using a variety of non-linear tools such as time lag embedding and stochastic interrogation, and discussions of their intricacies when used in non-smooth systems yield important observations for the experimentalist studying impacting systems. </p><p>The focus is on experimental results with numerical validation, and spends much time discussing identification of these concepts from an experiment-first mindset, rather than the more traditional analytical-first approach. As such a large volume of experimentally important information on topics such as transducers and forcing mechanism construction are included in the appendices.</p> / Dissertation

New, dated impacts discovered on Mars and the Moon provide direct observations of modern bombardment in the inner Solar System and the freshest available examples of recent craters. Their population, morphology, formation and modification processes relate to issues with secondaries and help calibrate cratering chronology models. I use a subset of the new impacts to measure the current production function at Mars. The resulting production function is a factor of approximately four lower than widely-used models, and the size frequency distribution has a shallower slope. This discrepancy between the measured current impact flux and model predictions could be due to many issues, so craters <~50m diameter should not be used for crater age dating unless the uncertainties are understood. I find that these new martian craters are only slightly deeper on average than the expected depth/diameter ratio (d/D) of ~0.2 for simple primaries; the majority would not be mistaken for secondaries based on d/D. A wide spread in d/D indicates that impact conditions or target properties might influence final crater morphologies at these sizes. Extended low-albedo features surround these new craters, presumed to have formed when the impact blast disturbed a surface coating of high-albedo dust, exposing a darker substrate. Some of these features changed drastically over a few Mars years, however, half of the sites show no changes at all. Estimated fading lifetimes cluster around ~7 Mars years. Controls on the amount and rates of fading have yet to be determined. These results show that the current impact production function is not under-sampling new impacts due to fading prior to detection. New craters have also been discovered on the Moon, using similar techniques. Five new impact craters were found that formed within the last ~40 years. Conclusions are unreliable with only these scant statistics, but preliminary comparisons indicate they follow the expected size frequency distribution predicted by the Neukum [1983; Neukum et al., 2001] production function and chronology. This also leads to a very preliminary measurement of the current Moon/Mars cratering ratio at a single diameter, which falls below models by only a factor of approximately six.

Reptile populations are suffering substantial global losses and roads are identified as one of the leading threats to their persistence. Currently, efforts to mitigate this threat are being implemented with various levels of success. I studied the effectiveness of exclusion structures (i.e., fencing) at preventing reptiles from gaining access to the road, and reducing road mortality. I also examined if population connectivity structures (i.e., ecopassages) were effective at reducing habitat and population fragmentation and allowing individuals to access habitats, resources, and mates on both sides of a major road (4 lane highway). I found that the fence was ineffective at preventing reptiles from gaining access to the road; however, reptiles were observed using the ecopassages to cross the road. Behavioural trials testing painted turtles’ (Chrysemys picta) willingness to use an ecopassage demonstrated that refusal was twice more likely than use of an ecopassage. I also examined the potential for roads to pose a physiological threat to roadside populations of reptiles by examining corticosterone (CORT), a stress hormone linked to negative health effects in cases of elevated levels over the long-term. To assess if individuals living near a major road had higher CORT levels than individuals from a less impacted population, I developed a novel means of measuring CORT from painted turtle claws in partnership with Dr. Gabriela Mastromonaco (Toronto Zoo). With long-term CORT levels considered as a proxy for chronic physiological stress, I did not find evidence that populations near roads had altered stress levels. However, this seminal study will provide the framework for further examination of more species, including species-at-risk, and a better understanding of effects of anthropogenic environments on wildlife health. As road ecologists strive to expand our understanding of the threats roads pose to reptiles, it is important that this field spans multiple disciplines, so that we can both understand the direct and indirect threats that roads cause and develop effective mitigation that preserves biodiversity within our anthropogenic landscape.

The overall objective of this research project was to assess whether fish populations in areas of potato cultivation responded to changes in environmental conditions. An effects-based assessment was conducted in the ‘potato belt’ of northwestern New Brunswick in the Little River catchment. From 1999-2001, the health and performance of slimy sculpin (Cottus cognatus) was monitored in agricultural and forested sections of the river. In the fall of 1999 and 2000, agricultural sites had fewer young-of-the-year (YOY) sculpin than the forested region. Adult sculpin were larger in the agricultural region, but had significantly smaller gonads, and female sculpin had smaller livers, and fewer and smaller eggs than the forested region. By the fall of 2001, only female gonad size showed a difference from the forested region. These results were used to design a follow-up study designed to investigate the relative importance of environmental factors influencing sculpin responses. <br><br> The second study investigated the relative influence of temperature and sediment deposition on slimy sculpin populations across 20 sites on 19 streams in forested and agricultural catchments in northwestern New Brunswick. YOY sculpin were present at all forested sites, but only at 2 of 11 agricultural sites. There were no relationships between body size or density and sediment deposition in either the agricultural or forested regions, but sculpin density decreased and median YOY size increased with increasing temperatures. The variability in density of YOY sculpin at agricultural sites suggested that additional factors beyond temperature might be contributing to responses. <br><br> A secondary overall objective was to evaluate the slimy sculpin as a sentinel and indicator of site-specific conditions. Stable isotopes of muscle tissues showed little variability in isotopic signatures, and significant differences between adjacent sites. Passive integrated transponder (PIT) tags implanted in 112 adult sculpin showed that 75% of sculpin captured over 10 months moved less than 30m. Both isotopes and PIT tags suggested high spatial and temporal residency of slimy sculpin. <br><br> This PhD project showed biological impacts on sculpin populations residing in streams influenced by non-point source agricultural stressors, and provided support for the ability of the slimy sculpin to reflect local environmental conditions.

No description available.