VictorJuiz/thesis huggingface dataset:
Origin of the Boléo Cu-Co-Zn deposit, Baja California Sur, Mexico: implications for the interaction of magmatic-hydrothermal fluids in a low-temperature hydrothermal system

Boléo is a stratiform Cu-Co-Zn deposit that surrounds the town of Santa Rosalía on the eastern side of the Baja Peninsula. Mineralization consists of finely disseminated sulfides within marine claystones and tectonically triggered debris flow sediments that occur at the base of episodic fan-delta cycles of the Miocene Boléo Formation, which comprise the initial rift-fill sediments within the Santa Rosalía basin. Rifting and hydrothermal activity is related to the formation of the Proto-Gulf of California. Mineralization occurs as eight mineralized ore beds, or mantos, that are recognized over 90 km2 and yield a 464 Mt resource grading 0.70% Cu, 0.06% Co, and 0.71% Zn. A red-bed model has been used previously to explain ore genesis. However, this research presents an exhalative origin, in which low temperature metalliferous brines (<120°C as constrained by oxygen isotope geothermometry) discharged onto the basin floor and infiltrated down into the sedimentary pile. The model is supported by the following evidence: (i) the abundant replacement of diagenetic pyrite; (ii) occurrence of mineralized rip-up clasts in the breccias; (iii) the concentric decrease in Cu/Zn ratio towards the basin margins; (iv) the vertical decrease in Cu/Zn within the mantos; (v) K-Ar ages of Mn oxide mineralization, where the most reliable age of 7.0 ± 0.2 Ma is within the range of published ages for the Boléo Formation; (vi) sulfur isotopes, which range from ∼−30‰ to 0‰ and indicate sulfur from diagenetic sulfides and from high temperature bacterial sulfate reduction; and, (vii) covariations in δ 13C and δ18O of carbonate alteration, which are consistent with the replacement of marine calcite by hydrothermal calcite-siderite. C, O and Sr isotopes also show that brine interacted with pore fluids/seawater that was highly depleted in 13C due to a component of fluvial waters introduced during conglomerate and debris flow deposition. Potential metal sources were also investigated. Leaching of red-bed conglomerates or basement plutonic and volcanic rocks would have provided an insufficient quantity of metals, although the Pb isotopic compositions of the sulfides indicate that some leaching of basement did occur. Unique trace element relationships have led to the suggestion that a magmatic fluid derived from Cerro San Lucas magmas could have supplied the metals.
The rejection of endocrine disrupting and pharmaceutically active compounds by membrane filtration

This research examined the rejection of multiple endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PhACs) by membranes from various water matrices including laboratory-grade water, laboratory-prepared waters, Lake Ontario water and membrane bioreactor (MBR) effluent. The overall objective was to examine rejection as a function of compound properties, membrane properties and feed water characteristics in order to gain a better understanding of rejection mechanisms.

Keywords: Environmental engineering
Evaluating user preferences for public transit technologies in the Greater Toronto Area

There are many different factors that affect the ridership potential of public transit technologies, many of which are difficult to quantify. Some of these effects include reliability, comfort, safety, and accessibility. In addition to these effects, it is often hypothesized that travelers have inherent preferences for certain public transit technologies independent of their actual service characteristics. In light of these uncertainties, the goal of this research is to quantify these technology preferences and to discover whether there are modal biases in the Greater Toronto Area (GTA) that are independent from mode level of service characteristics. This study uses travel survey data to build discrete choice models incorporating transit technology specific variables to quantify existing preferences in the GTA. The results show that a preference for rail (Subway and Streetcar) exists, but the magnitude of this effect cannot be quantified due to difficulties isolating the technology preference from other service characteristics.

Keywords: Local transit, Public opinion
Local transit, Ontario
Consumers' preferences, Ontario
Obosom Tigare of Nsiakrom: a study of an indigenous religious movement among the Akan of Ghana

There is a Sankofa voice being raised as a signal to search for the knowledge and wisdom of African ancestors/ancestresses. This study is a contribution to search for African identity and culture—something we have almost lost due to foreign influences. But these foreign influences are eating us up, making us bitter and frustrated. The Obosom Tigare was brought from Niapala in the Upper Region to Nsiakrom as an agricultural cult but today it has become one of the “African indigenous religious movement” striving for the African “discovery and recovery” of cultural values. In retaining the Akan cultural and religious traditions, it is one of the most powerful African cults in Ghana expressing the Akan practical needs. Also, it deals with new social problems. In order to preserve continuity and cohesion the cult has retained part of the old Akan traditions and added modern traditions to them. The pattern of religious behaviour involved in Obosom Tigare cult is similar many respects to that of the ancestral spirits and natural deities of the Akan. It has become a tool for Akan cultural survival and explains that religion goes beyond mere relation between human beings and super human beings. This study emphasizes an “insider” methodology which I define as auditory, visual, and kinesthetic. In the auditory method, the researcher does not only listen but becomes part of the religious community. The visual method enables me to look at religion in the “raw” that is, to look at what people do as well as what people say, and thus to come terms with religion as it is lived. The kinesthetic method allows me to participate in the ceremonies through drumming, dancing, and singing. Sometimes I accompanied Okomfo Afua Nsiah to the bush to search for herbal medicines. Through these and other methodologies I tried, as much as possible to adopt the indigenes' point of view. Written by someone who is an indigenous speaker, a Christian minister, as well as an anthropologist, this is a unique exploration of how Obosom Tigare acts, speaks, and responds to human needs. Using the Obosom Tigare of Nsiakrom as a case study, this work shows how indigenous healers have important advantages as biomedical healers and that Ghana is tapping some of these advantages in order to solve some of her medical problems.
Effects of asynchronous CMC and face-to-face discussion on oral production

Recent research suggests that there are many aspects of online discussion that may make it better for language learning than face-to-face discussion. In this quasi-experimental study, equality of participation and individual output in face-to-face discussion were measured after treatment. Treatment consisted of ten female university students non-randomly placed into two groups of five students each. The first group participated in an online discussion board for seven weeks. The second group discussed the same issues face-to-face for seven weeks. Pre-study and post-study measures of variables were taken and analyzed. Results showed; (a) no increase in equality of participation; (b) an increase in subsequent oral production of the target language by the face-to-face group but a decrease in production of target language by the ACMC group; (c) an increase of TOEIC scores in both groups, and (d) an increase in the use of the L1 (Japanese) in subsequent oral discussion by the ACMC group. Based on the results of this study, ACMC discussion appears to have an overall negative effect on oral production of the L2.
Canadian nationals and NAFTA: extending equality in treatment to nationals adversely affected by state measures

In this paper, I explore the effect of the North American Free Trade Agreement ('NAFTA") on Canadian nationals that are similarly situated to foreign investors in Canada, but do not qualify as 'investors" for the purpose of the treaty protections in NAFTA Chapter 11. When Canada implemented NAFTA into domestic law, it precluded the agreement from having direct effect. As a consequence, the operation of NAFTA Chapter 11 in Canada, which confers rights on foreign investors to challenge state measures in accordance with the treaty terms, places similarly situated Canadian nationals at a disadvantage. I argue that that the substantive rights conferred by Chapter 11 on foreign investors operating within Canada should be extended to Canadian nationals either through application of the doctrine of direct effect, or alternatively through the implementation of appropriate targeted national measures. In light of Canada's existing position on the effect of NAFTA Chapter 11 in domestic law, I discuss options open to Canadian nationals. First, I discuss possible use of international mechanisms to access the Chapter 11 substantive protections and process. Second, I discuss possible Canadian domestic remedies where similarly situated Canadians are adversely affected by a state measure for which there is no (or inadequate) domestic remedy, but a remedy is available to foreign investors under NAFTA Chapter 11.
Reactions at the air-aqueous interface

A glancing-angle laser-induced fluorescence technique has been used to investigate three unique reactions at the air-aqueous interface:The rate of the reaction of bromide with ozone depends upon the bulk bromide concentration in a way which implies a surface reaction. The rate is enhanced by an octanol coating, as expected if the presence of ozone at the surface is required for reaction. The surface hydrolysis reactions of some atmospherically relevant acids and bases are suppressed when the interface is coated with 1-octanol. The degree of suppression depends on the amount of octanol present. Results are related to the amount of available water at the interface, and are supported by a computational study. The surface reaction of ozone with chlorophyll is well described by a Langmuir-Hinshelwood model. However, when sea-salt solutions are illuminated in the visible, the reaction rate is significantly photo-enhanced by some unknown mechanism.
Investigating the sensitization of AML cells to arsenic trioxide: A three-pronged approach

Arsenic trioxide (As2O3) is currently used as the second-line therapy for Acute Promyelocytic Leukemia (APL), a subtype of Acute Myeloid Leukemia (AML). Despite the success of As2O 3 as treatment for APL, it is ineffective in the treatment of non-APL AML. The identification of molecules that increase the cytotoxicty of As 2O3 has prompted the investigation for novel, more effective As2O3 sensitizers. We used a three-pronged approach to investigate the potential sensitization of various AML cell lines. First, we used a mechanism-base approach, targeting one of the known mechanisms of action of As2O3. Second, we investigated clinical evidence that As2O3 enhances the effects of ara-c. Finally, we performed a high-throughput screen to identify As2O3 sensitizers present in compound libraries composed of off-patent drugs and natural compounds.
Characterization of minimalist fusion hybrids of Arnt in a yeast one-hybrid system

Minimalist hybrids comprising the DNA-binding domain of bHLH/PAS protein Arnt and leucine zipper of bZIP protein C/EBP were designed to bind E-box (5'CACGTG). Swapping of the Arnt PAS domain for C/EBP leucine zipper generates the hybrid ArntbHLH-C/EBP, which binds to E-box modestly in the yeast one-hybrid system. Positive binding was also observed when ArntbHLH is fused to the Max leucine zipper; therefore, leucine zippers from different protein families can replace the Arnt PAS domain for effecting homodimerization. Removal of the Arnt HLH domain or the nonnative leucine zipper yields nonfunctional proteins, suggesting that two dimerization domains work in conjunction of each other and are essential for DNA-binding. Additionally, random mutants of our fusion hybrids of Arnt were screened for improved E-box binding function in a modified yeast one-hybrid system. Our minimalist design strategy successfully reduced the size and structural complexity of native Arnt bHLH/PAS to a functional bHLH/ZIP-like structure.
Interaction between intracortical inhibitory circuits in the motor cortex of Parkinson's disease patients

Abnormal cortical inhibition in the motor cortex of Parkinson's Disease (PD) patients may be responsible for hypokinetic movements. Transcranial magnetic stimulation (TMS) can be used to non-invasively evaluate different cortical inhibitory circuits. These include short interval intracortical inhibition (SICI), mediated by GABAA receptors, and long interval intracortical inhibition (LICI), mediated by GABAB receptors. In PD, SICI has been suggested to be decreased while LICI is increased. A possible explanation is that LICI inhibits SICI through a presynaptic GABAB mechanism. This thesis focused on testing this hypothesis and we characterized how LICI influences SICI in PD patients. Our observations demonstrate that the inhibitory effect of LICI on SICI was reduced in PD when compared to controls and was not corrected by dopaminergic medication. This suggests there is abnormal presynaptic inhibition in PD. Additionally, our results also suggest that the time course for presynaptic GABAB inhibition is different from that of postsynaptic GABAB inhibition.
Optimal bus service design in competitive contracting

The objective of this research is to revisit some of the transit planning tasks in view of such evolving transit market and regulatory arrangements. The paper investigates the implications of an evolving market arrangement, namely competitive contracting, on mass transit service design. Competitive tendering elements that relate to determining the size of the contract to be tendered as well as allocation of routes among bid packages (also known as Service Design) are addressed. The Modelling framework used in this research includes Optimal Frequency Determination of the bus routes, Transit assignment and Genetic Algorithm-based Optimal Bid Packaging components. The proposed methodology has been applied to a case study of the City of Mississauga, Ontario. Transit planning has traditionally been approached from the point of view of a single, public operator that dominates transit service provision. Evolving transit market arrangements that have seen a larger potential role for the private sector in providing transit services in a competitive environment are bound to necessitate a transformation in the traditional transit planning approaches.
Molecular and phenotypic analysis of a new allele of ABSCISIC ACID-INSENSITIVE3 (ABI3)

Plants have the ability to enter a quiescent stage in their lifecycle by forming seeds. During maturation, the embryo acquires dormancy, storage reserves, and products related to desiccation tolerance. The best characterized regulator of these processes is the plant hormone abscisic acid (ABA). Genes involved in these responses have been identified, but little is known about how they contribute to maturation. This study analyzed an ABA-insensitive mutant isolated from a population of Arabidopsis seeds transformed with a T-DNA library. This mutant was named helmethead (helm) because cotyledons remained white and unexpanded so that only the root and hypocotyl emerge from the seed coat after germination. Because this defect has not been reported for other ABA-insensitive mutants, helm was the subject of characterization. Many lines of evidence support that the helm mutation is a new allele of ABA-INSENSITIVE3 (ABI3). Although the ABI3 coding region is unaffected, the majority of its promoter is not in tandem to this sequence. Defects similar to helm were observed in lines predicted to alter ABI3 expression including those with T-DNA insertions in the ABI3 promoter, ABI3 antisense lines and the severe abi3-6 mutant. Mutant abi3 alleles failed to genetically complement helm defects but over-expression of ABI3 was sufficient to confer normal ABA responsiveness and cotyledon growth. Relative to weak and severe abi3 mutants, helm defects are moderate. helm tissues were analyzed to determine the properties of the cotyledons that were defective. These observations support that embryonic storage functions are normal while post-germination functions likely prevent seedling growth of helm. Finally, as ABI3 is a transcriptional regulator, microarray analysis was performed. In addition to previously-reported ABI3- and ABA-regulated genes, those associated with desiccation tolerance and stress responses showed reduced expression in helm. Together, these results suggest that ABI3 regulates processes differently across embryonic tissues and that seed maturation is sensitive to ABI3 levels. As such, this study has contributed to our understanding of ABI3 function and extended the ABI3 allelic series to provide a more complete set of tools for studying seed development.
Investigation into factors that allow performance enhancement using widely linear receivers for space-time block code transmission

Transmit diversity has been proven to provide performance gains over conventional wireless communications systems, but the number of transmit antennas cannot be infinite. To further enhance performance, a detection technique called widely linear (WL) processing is proposed for space-time block coding and its effectiveness has been shown to be occasional under a limited number of test cases. The focus of this thesis is to define the system settings that would allow WL processing to benefit transmit diversity systems using space-time block codes (STBCs). In this thesis, Alamouti's STBC and the Lindskog-Paulraj STBC are tested with receivers that are designed for different channel characteristics with known or unknown channel state information. For the latter scheme, three MLSE receivers are invented for testing with time-varying channels. Their performance is found to be comparable to the original MLSE receiver for quasi-static channels, and one of them does not require any increase in complexity. Simulation results under different system settings established the main factors that influenced the system's favourability for WL processing.
Diabetes induced glycation of collagen inhibits the binding step of collagen phagocytosis

As physiological collagen turnover is mediated by the intracellular phagocytic pathway, we studied the impact of diabetes-induced glycation of collagen on the binding step of phagocytosis. Collagen glycation was modeled with methylglyoxal, a glucose metabolite that modifies arginine and lysine residues. Glycation was authenticated by fluorescence photometry, solubility and cross-linking. The proportion of phagocytic cells was estimated by flow cytometry. Glycation inhibited collagen binding in a time and concentration-dependent manner. Inhibition of binding was reversed by aminoguanidine. Glycation inhibited collagen binding strength and intracellular calcium signaling. MGO glycation of triple helical collagen peptides mimicking the α2β1 integrin binding site of collagen induced modification of arginine in the critical GFOGER integrin recognition sequence of collagen. MGO-induced cross-linking of lysines played only a small rote in binding inhibition. Conclusion: diabetes-induced loss of connective tissue homeostasis may involve glycation-mediated modifications of collagen that are required for recognition and binding in the intracellular, phagocytic pathway.
Cardiovascular response to functional electrical stimulation and passive stepping to improve orthostatic tolerance

Functional electrical stimulation has been used to attenuate the haemodynamic response to orthostatic stress in patients with autonomic disorders. It is believed that involuntary skeletal muscle pump activation increases the venous return and thereby mediates the effects of orthostatic stress. This theory has not been studied extensively in healthy individuals and thus the haemodynamic effect of involuntary stimulation is not well characterized. This study investigated the hemodynamic response from upright tilt during involuntary skeletal muscle pump activity using functional electrical stimulation (FES) and passive mobilization movement. The subjects experience orthostatic stress for 15 minute durations during which blood pressure, heart rate, and blood volume changes were recorded. During head-up tilt, application of FES to the lower limb muscles while the legs were not moving (isometric FES) was found to significantly increase heart rate, whereas the combination of FES with passive mobilization movements of the lower limb (dynamic FES) increased blood flow and cardiac output. Since dynamic FES may be better able to improve orthostatic tolerance, this modality should be further investigated as a potential therapy to prevent orthostatic intolerance.
1kW 10V to 400V converter for a solid oxide fuel cell

A new industry solid oxide fuel cell outputs 10V instead of 25V at 5kW, the power level intended for residential use. A 5kW 10V to 400V converter is designed using a simple cost-efficiency optimized approach. Power loss is modeled based on ideal waveforms allowing independent optimization for each component. Four topologies are analysed at a switching frequency of 20kHz and $0.9CDN per Watt: the voltage-fed H-bridge and push-pull prove to have a much lower cost function than their current-fed forms. A 1kW voltage-fed H-bridge prototype is built, working up to 417W output with 86.3% efficiency and 292V output. Projections to the desired 1kW load indicate the converter would output 350V with 89% efficiency. A conservative estimate for the cost of the high volume production of the prototype was sim;$153 USD. The estimate for the high-volume production of the 5kW unit was sim;$115 USD/kW.