Aim: Identifying how climate change, habitat loss, and corridors interact to influence species survival or extinction is critical to understanding macro-scale biodiversity dynamics under changing environments. In North America, the ice-free corridor was the only major pathway for northward migration by megafaunal species during the last deglaciation. However, the timing and interplay among the late Quaternary megafaunal extinctions, climate change, habitat structure, and the opening and reforestation of the ice-free corridor have been unclear. Location: North America. Time period: 15–10 ka. Major taxa studied: Woolly mammoth (Mammuthus primigenius). Methods: For central North America and the ice-free corridor between 15 and 10 ka, we used a series of models and continental-scale datasets to reconstruct habitat characteristics and assess habitat suitability. The models and datasets include biophysical and statistical niche models Niche Mapper and Maxent, downscaled climate simulations from CCSM3 SynTraCE, LPJ-GUESS simulations of net primary productivity (NPP) and woody cover, and woody cover based upon fossil pollen from Neotoma. Results: The ice-free corridor may have been of limited suitability for traversal by mammoths and other grazers due to persistently low productivity by herbaceous plants and quick reforestation after opening 14 ka. Simultaneously, rapid reforestation and decreased forage productivity may have led to declining habitat suitability in central North America. This was possibly amplified by a positive feedback loop driven by reduced herbivory pressures, as mammoth population decline led to the further loss of open habitat. Main conclusions: Declining habitat availability south of the Laurentide Ice Sheet and limited habitat availability in the ice-free corridor were contributing factors in North American extinctions of woolly mammoths and other large grazers that likely operated synergistically with anthropogenic pressures. The role of habitat loss and attenuated corridor suitability for the woolly mammoth extinction reinforce the critical importance of protected habitat connectivity during changing climates, particularly for large vertebrates.

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[pt] Esta dissertação desenvolve um modelo tratável de formação endógena de redes do mercado interbancário. Devido a choques de liquidez, bancos enfrentam um trade-off entre investir seus recursos num ativo líquido e num ativo ilíquido de alto retorno. O mercado interbancário é modelado como uma rede. Um link estendido por um banco a outro é interpretado como uma linha de crédito da qual o primeiro banco pode tomar emprestado ativos líquidos do segundo para cobrir fluxos de saída de recursos. O Banco Central, através de linhas financeiras, empresta recursos aos bancos com saldos negativos e toma emprestado de instituições com saldos positivos a taxas por ele estabelecidas. Essas taxas definem um corredor no qual a taxa cobrada em empréstimos interbancários deve estar contida. Nesse contexto, caracterizamos o equilíbrio (único) nas decisões de investimento dos bancos para qualquer rede. Em seguida, endogenizamos a rede, através da decisão dos bancos de linhas de crédito, e mostramos que toda rede em equilíbrio é uma rede de núcleo-periferia completa. Esse resultado é consistente com redes empiricamente observadas. Ademais, introduzimos um trade-off para Bancos Centrais ao decidir o corredor de juros: um corredor mais estreito dá mais controle ao Banco Central sobre a taxa interbancária, o que é importante para a condução de política monetária. No entanto, se considerarmos as decisões de links dos bancos, isso pode levar a um equilíbrio com uma rede mais esparsa, onde o investimento total no ativo líquido é maior, o que representa um custo implícito, já que esses recursos poderiam ser investidos no ativo mais produtivo. No geral, nossa análise ressalta o importante papel que redes endógenas têm na transmissão de política monetária. / [en] This paper develops a tractable endogenous network formation model of the interbank market. Due to liquidity shocks, banks face a trade-off between investing their resources in a liquid asset and a high-yield illiquid asset. The interbank market is modeled as a network. A link extended by one bank to another is interpreted as a credit line from which the former bank can borrow a share of the latter s liquid assets to cover liquidity outflows. The central bank, by means of its standing facilities, lends resources to banks that are short in liquidity and borrows from institutions with liquidity surpluses at predetermined rates. These rates establish a corridor in which the rate that banks charge for interbank loans must lie. In this setting, we characterize the unique equilibrium of banks liquidity holdings for any network. We then endogenize the network, via banks decision of credit lines, and provide a sharp equilibrium characterization: every equilibrium network is a complete core-periphery graph. This characterization is consistent with empirically observed networks. Moreover, we introduce a trade-off for central banks when choosing the corridor rate: a narrower corridor implies more precise targeting of the interbank rate, which is important for the conduct of monetary policy. However, if we account for banks linking decisions, this may lead to an equilibrium with a sparser network, where total liquidity holdings are higher, incurring an implicit cost since these funds could be invested in the more productive illiquid asset instead. More generally, our analysis highlights the important role that endogenous networks play in the transmission of monetary policy.

The intent of this thesis is to explore the design challenges and opportunities presented by the reintroduction of passenger rail to a small economically challenged New England city. Central to my thesis is that the advent of more efficient transportation options is not, in itself, enough: the infrastructure built to support those options must provide users with a comfortable, safe, and welcoming experience. The architecture of the rail station is critical in influencing that behavior and moving our society toward greater energy efficiency. Holyoke is a small mill city in western Massachusetts whose fortunes peaked in the early twentieth century and today struggles with decaying buildings and infrastructure, high unemployment, and significant poverty. The city also has many strengths, including relatively inexpensive hydro-electric power, sturdy adaptable mill buildings, an excellent location, strong neighborhood and civic pride, and a rich history on which to build. The city’s boosters feel that it is ripe for a renaissance already being driven by industry, the creative economy, telecommuters escaping the region’s major cities, and tourism. This research component of this thesis will explore: Current and historical demographic, industrial, and commercial context of the city and its passenger rail service, including usage projections, connections with various parts of the city, and Transit Oriented Design implications The needs of the adjacent Flats neighborhood for basic services and community space; strategies for attracting more consistent use of the station throughout its hours of operation by meeting the neighborhood residents’ needs Potential requirements for a station’s future capacity and adaptability – it will consider strategies for creating a flexible and adaptable building so as to meet the needs of the station and city as it changes over time Precedents that include rail stations and public buildings – it will investigate strategies used by effective public buildings The design component of this thesis incorporates the above research in developing site and program plans with a specific focus on design strategies that address accessibility, wayfinding, relevant services, and creating a welcoming gateway into the residential, industrial, and commercial heart of the city.

This thesis comprises two studies that investigated bike infrastructure safety in North America. The first study conducted a corridor-level analysis to quantify the safety of different bike infrastructure types and assess the influence of corridor-specific characteristics on their performance. Using a Poisson-lognormal Full Bayesian model, the study analyzed fatal and injury bike-vehicle collisions on over 7800 corridors in Toronto, Canada. The findings revealed that bike infrastructure effectively reduces bike collisions, with cycle tracks demonstrating superior safety benefits due to the physical separation of cyclists from vehicular traffic. Cycle tracks were found to be particularly effective on long corridors with fewer intersections as bike-vehicle interactions along the corridor are minimized. Signed routes were safe on low-volume and low-speed roads, while bike lanes are more suited for a short section of high-volume corridors with a high intersection density. The second study assessed the safety of parking-protected bike lanes (PPBL), a new concept that is rapidly growing in North America. Utilizing data from nineteen street sections in Vancouver and Ottawa, the study developed a Full Bayesian Before-and-after model to evaluate the safety impacts of converting traditional painted bike lanes to PPBLs. The results indicated a significant reduction of 31.2% in total collisions after PPBL implementation. However, the effects of PPBLs on cyclist safety were found to be sensitive to factors such as bike path opening density, intersection density, and intersection treatments. In roads where proper intersection treatments and minimal protection of PPBL openings can be provided, painted bike lanes can be converted into PPBLs, and significant safety benefits can be expected. The findings of this thesis offer practical guidance for city planners and policymakers regarding the safety implications of different bike infrastructure types and the most appropriate conditions to implement them, which supports bike safety enhancement initiatives and attracts more people to bike. / Thesis / Master of Applied Science (MASc) / This thesis presents two studies that offer valuable insights to improve bike safety. The first study examined the safety of various bike infrastructure types along with the impact of corridor characteristics on their performance. The findings emphasized the effectiveness of cycle tracks in reducing collisions on long corridors with fewer intersections. Signed routes were found to be effective on low-volume and low-speed roads, while bike lanes were ideal on short sections of high-volume roads with a high intersection density. The second study assessed the impacts of new designed concept, known as the parking-protected bike lanes (PPBLs). The study showed that converting painted bike lanes to PPBLs significantly reduced total collisions. However, proper treatment of intersection and bikeway openings is crucial for enhancing cyclist safety and reducing multi-vehicle rear-end collisions. Where proper intersection treatment and minimal protection of bikeway openings can be provided, bike lanes can be safely converted into PPBLs.

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<p dir="ltr">The Dorothy and Ray Garman Preserve is a 35.4 hectare tract of hydro-mesophytic forest that includes ephemeral pools and scrub-shrub wetlands with <i>Cephalanthus occidentalis</i> as the dominant species component, a previously farmed agricultural field (now planted with native trees), and areas within that field which have reverted into wetlands. Garman is located within the Cedar Creek Conservation Area of Allen County, a region of important biodiversity in northeast Indiana. To document the structure and composition of the plant communities at this property, I utilized random and systematic plot samping, as well as a meandering floristic survey. The focus of my efforts was to explore the forested portion of the property and its immediate margins. I counted 150 species, representing 53 genera and 50 families. Using the Floristic Quality Assessment (FQA) method, eleven species had coefficient of conservatism values of 8-10, ten of which were herbaceous and one arboreal species (<i>Populus heterophylla</i>). This indicates that Garman is a relatively high-quality site with some quality remnant components. The site has an FQA value of 46.4, and the mean coefficient of conservatism was 3.8. Furthermore, 95.3 percent of the total species documented were native, a relatively high mark for a fragment within a larger suburban area. Species potentially indicative of bog habitats such as <i>Sphagnum fimbriatum </i>(a non-vascular species of interest), <i>Ilex verticillata</i>, and <i>Viola nephrophylla</i>, as well as historical occurrences of other peatland communities in the area, indicate that Garman may have historically been a true bog that has since senesced into buttonbush wetland type due to anthropogenic impact. Overall, the vascular plant flora of Garman demonstrates that this site is of unique importance to the broader Cedar Creek Conservation Area, since it contains several plant species not present at other sites within this region, as well as intact natural plant communities.</p>

There has long been a recognition that efficient transport plays a key role in supporting a dynamic economy and a high quality of life. However, traffic increases along with population and income, and traffic congestion and accidents are negative results of this increase, as is environmental damage. There has been a need for a methodology to evaluate user, nonuser benefits and the environmental impacts of transportation investments and policies through rational, objective scientific analysis. This research aims to develop a methodology, termed the Transportation/Development Methodology, for evaluating transportation policies and projects, and also, to clarify the relationships between transportation investment and economic productivity. Transportation/Development Methodology, or TDM, conceptualizes the role of transportation in a broad socioeconomic and environmental context and enables scenario analysis. In addition to the development of the TDM, this research comprises a critique and discussion of the primary methodologies used for evaluating transportation effects. In both transportation and development management, policy processes tend to proceed in nearly total isolation from ongoing planning activities in estimating impacts induced by transportation investments and policies. To overcome that imbalance for current models, TDM uses a system dynamics approach and adopts concepts from other methodologies, such as Input-Output analysis, the Lowry Model, and the Urban Transportation Planning Process (UTPP). Finally, this research demonstrates the TDM by applying it in an analysis of a “real-life” situation, the Interstate 81 corridor, which goes through six states of the United States as a backbone of both passenger and freight transport. Development scenarios for improving regional economies, as well as for giving better service and reducing congestion, are analyzed by the TDM im order to evaluate their effectiveness. Application of the TDM to the I-81 corridor generates significant conclusions that would not have been possible using existing methodologies. / Ph. D.

The standard method for assessing traffic safety is to use the predictive method outlined in the Highway Safety Manual (HSM). This method is site-level, data-intensive, and does not account for interactions between sites, making it difficult to assess larger areas. This dissertation develops a corridor-level approach to traffic safety which uses less data than the HSM predictive method and views roadways holistically rather than combinations of individual, independent sites. First, a corridor definition is developed and applied to 10 urban Florida counties with a history of many crashes, resulting in the identification of 1,048 corridors. These corridors were primarily defined using context classification and lane count, with additional considerations for data availability and minimum length. From 2017–2021, these corridors experienced 459,603 unique crashes. After preliminary modeling and scope refinement, 559 corridors received supplemental data collection. Between the two datasets, a total of 11 models were developed using either negative binomial (NB) or random forest (RF) regression. NB models can be used for network screening purposes or identifying the impacts of potential safety improvements, while RF models can be used to identify variables important to the accuracy of the prediction. Potential safety improvements identified from the NB models include increasing proactive law enforcement patrols for dangerous driving behaviors and installing corridor lighting in corridors without lighting. While both NB and RF models were accurate, NB models were recommended due to resulting in a definite equation and overdispersion parameter that could be used with the empirical Bayes (EB) method to improve prediction accuracy. Overall, the corridor-level NB models outperformed the HSM models in terms of accuracy and statistical reliability. Using a corridor-level approach can help agencies quickly network screen their systems to identify high-risk corridors in need of safety improvements or supplement site-level analyses.