VictorJuiz/thesis huggingface dataset:
Guidance-based rendezvous with moving objects in dynamic cluttered environments

The focus of this Thesis is on the following two autonomy aspects for intelligent and autonomous vehicles: (i) time-optimal interception and rendezvous with a moving object and (ii) obstacle avoidance. This Thesis presents two novel time-optimal on-line trajectory planning algorithms that allow a vehicle to navigate autonomously in dynamic cluttered environments, while avoiding other moving objects, in order to intercept and rendezvous with a moving target. The proposed trajectory planners are implemented in both computer simulations and experimentation. The results show that the proposed trajectory planner using velocity obstacles is able to achieve tangibly faster interceptions. The first algorithm implements static method of obstacle avoidance. A rendezvous-guidance technique is utilized in conjunction with a modified cell-decomposition method. The second algorithm implements a dynamic method of obstacle avoidance. Here, the problem is addressed by utilizing a modified version of the velocity obstacle approach, again augmented with a rendezvous-guidance algorithm.
Phenotypic plasticity to light competition and herbivory in Chenopodium album

Little is known about how the expression of plasticity affects subsequent plasticity in response to new environments. I addressed this question in two ways: first, by exposing plants to light competition and then subsequently challenging them with insect herbivory, and second, by exposing plants to herbivory and then subsequently challenging them with light competition. Since both light competition and herbivory affect resources available to plants, I also controlled for the effects of resource reduction when these factors are imposed. I found that an initial plant response to light competition attenuated the subsequent expression of induced resistance on whole plants but not on excised leaves. I also found that an initial response to herbivory did not affect subsequent response to light competition as measured by plant height. Therefore, I found that plants are able to express phenotypic plasticity following previous expression of plasticity to a different environmental factor.
Type I interferon receptor interactions

Type I interferon (IFNs) engage a common receptor complex to elicit the characteristic antiviral, anti proliferative and immunomodulatory responses associated with these cytokines. Due to the biological responses evoked by Type I IFNs, they have been useful in the treatment of viral infections and neoplasias. There is renewed interest in exploring the biology of Type I IFNs based on recent findings that implicate this family of cytokines in the regulation of responses that bridge innate and adaptive immunity. The primary objectives of this work are to further the understanding of Type I IFN interactions with the Type I IFN receptor complex and to create and evaluate the next generation of IFN molecules and IFN mimetics. ...

Keywords: Immunology
DNA double-strand break sensing and repair under continued hypoxia as a model for hypoxia-induced genetic instability

Incorrectly repaired DNA double-strand breaks (DNA-dsbs) are dangerous residual lesions that can result in cellular carcinogenesis. Tumour hypoxia is linked to genetic instability, although the effect of continual hypoxia on DNA-dsb processing is unknown. DNA-dsb sensing and repair can be tracked using quantitative microscopic imaging of nuclear repair foci. Using non-proliferating G0/G1-synchronized human fibroblasts, I tested whether sensing and repair of DNA-dsbs are altered in cells exposed to ionizing radiation (IR) while under continual oxic, hypoxic or anoxic conditions. I observed increased residual gamma-H2AX, 53BP1 and ATMSer1981 foci and defective DNA-dsb rejoining (assessed by neutral Comet assays) 24 hours post-IR in hypoxic cells. Residual DNA-dsbs did not lead to decreased clonogenic survival. The results in this thesis support the hypothesis that prolonged hypoxia may lead to decreased DNA-dsb repair. These findings are consistent with aberrant DNA-dsb repair being a potential factor for the observed genetic instability in hypoxic tumour cells.
Polyferrocenylsilanes: networks, microspheres, and molecular motions

The synthesis and characterization of a series of crosslinked polyferrocenylsilane (PFS) networks are reported. These crosslinked PFSs have improved thermal stability relative to their linear counterparts. The solubility parameter (δ) for the linear homopolymer was estimated to be 18.7(7) MPa 1/2 by swelling measurements. Reversible electrochemical oxidation of the gel was observed at oxidation potentials greater than 450 mV (vs Ag/AgCl), consistent with the oxidation potential of the linear homopolymer. The molecular motions in PFSs were investigated using variable temperature solid state 2H NMR. The 2H NMR spectra of the ferrocene deuterated polymers indicated that the cyclopentadienyl groups were static at temperatures below their particular mechanical Tg. At temperatures just above Tg the cyclopentadienyl rings underwent slow small-angle oscillations which increased in both rate and angle of excursion until undergoing a transition characterized by rapid isotropic motional averaging at 50–70°C above their Tg. The silicon side group motions were also examined over the same temperature range using the selectively labelled methyl- or methoxy deuterated PFSs. Increasing the temperature of the sample above their respective mechanical Tgs brought about spectral changes reflecting a superposition of backbone and side-chain motions. The synthesis of crosslinked PFS microspheres (PFSMS), formed under mild reaction conditions are reported. The effects of temperature, monomer ratio, solvent composition, catalyst concentration, and time on the observed morphology were investigated and were interpreted in terms of a mechanism for PFSMS formation. Chemical oxidation of the PFSMS led to positively charged particles that underwent electrostatically driven self-assembly with negatively charged silica spheres to form composite particles. Pyrolysis of the PFSMS led to spherical magnetic ceramic replicas with tunable magnetic properties that self-organize into ordered 2-D arrays at an air-water interface under the influence of a magnetic field. Thin films (25–500 nm) of the amorphous diblock copolymer poly(styrene-b-ferrocenylethylmethylsilane), spontaneously self-assemble into vertically oriented cylinders of PFS in a PS matrix on a variety of substrates by spin coating or dip-coating techniques. Remarkably, perpendicular domain orientation to the substrate was found to occur irrespective of the polarity of the substrate surface. Subsequent pyrolysis of PS crosslinked films afforded ordered ceramic nanoparticles on the substrate surface. The synthesis and characterization of two random copolymers poly[ferrocenyldimethylsilane- r-ferrocenyl(ethoxymethacrylate)methylsilane], and poly[ferrocenylethylmethylsilane- r-ferrocenyl(ethoxymethacrylate)methylsilane] are reported. Solutions of the soluble polymers in toluene with a photoinitiator (2,2-dimethoxy-2-phenylacetophenenone) produced an insoluble polymeric material that precipitated from solution upon exposure to sunlight.
Organizational resistance to community-based forest management in Forest Department, India

The major objective of this study is to examine suitability of the bureaucratic management principles to the community-based forest management (CBFM), and to conceptualize and investigate three different types of organizational resistance to the CBFM, in four Indian state Forest Departments (FD). Using perceptions of the foresters and structural modeling techniques, three theoretical models are tested and variations across the four states and three management levels are explored. In the first model, the construct of organizational bureaucracy is construed as comprising of hierarchical rigidity, centralization of powers, non-participatory decision-making, and organizational rigidity, while acceptability of CBFM is composed of structural acceptability, cultural acceptability, and organizational support. The results reveal a high degree of incongruity between these two constructs that varies across the states but is uniform across the management levels. These differences suggest that the uniform organizational reforms, across states, pursued by the Government of India may prove counter productive. The final model consists of two dimensions of resistance to change (structural resistance and cultural resistance) and four categories of resistance factors (organizational, service related, personal, and environmental factors). Empirical results confirm the existence of structural and cultural resistance, and reveal that the foresters perceive greater resistance in the organizational structure than in the organizational culture. The results indicate that organizational bureaucratization is the major causal factor of structural resistance, while innovative culture has the most mitigating influence on 'cultural' resistance. The second model examines two dimensions of attitudinal resistance---disapproval of the CBFM systems by the foresters at an individual level and at organizational level, and four categories of causal factors of resistance---personality traits, service related features, external environmental factors, and socialization factors. The study suggests that members of the four state FDs of India have less resistance at an individual level, but show high resistance to the implementation of CBFM by the organization. Results further suggest that fear of losing prestige and authority is a major cause of resistance at the personal level, while hierarchical attitude is a primary causal factor of resistance to organizational level implementation. Some of the causal factors of both kinds of resistance show dissimilar effects across the four states and also across the management levels.
5-Methylthioribose kinase: Structure, function and drug design

The crisis of rising antibiotic resistance in human pathogens calls for the development of new antibiotics. The methionine recycling enzyme, 5-methylthioribose (MTR) kinase, has been identified as a drug target because it is a key enzyme in bacterial methionine salvage and is absent in mammalian cells. As the first step of structure-based drug design, the structure of MTR kinase from B. subtilis was determined in several states in the reaction coordinate (apo, ADP, ADP-PO4, AMPPCP and AMPPCP-MTR), while the A. thaliana enzyme was determined in complex with ADP. These crystal structures represent the first structural studies of MTR kinases. The crystallographic phases were determined by a novel nucleotide-holmium derivative. The technique of holmium phasing can be a general strategy for determining the crystal structure of many medically relevant proteins that bind nucleotide and metal ions. MTR kinase exhibits structural features that include a glycine rich G-loop, a catalytic HGD-motif, a Mg(II)-binding DXE-motif, a semi-conserved W-loop and a MTR-binding RR-motif. Although MTR kinase related to eukaryotic protein kinases the enzyme reveals a unique mode of nucleotide binding, raising questions on the role of metal coordination in the protein kinase-like superfamily. MTR kinase does not appear to display inter-lobal motions during catalysis as in a protein kinase, shedding light on the link between inter-lobal conformational changes and regulation of enzyme activity. Finally, the analysis of MTR kinase structures in the ground states has so far favoured a dissociative mechanism of phosphate transfer.
Role of the angiopoietin/Tie2 system in a rodent model of hypoxia-induced pulmonary arterial hypertension

Introduction. The pulmonary microvasculature is incompletely muscularized, consisting mainly of an EC monolayer and scant matrix support. Thus, the distal pulmonary arterioles may be predisposed to regression on exposure to environmental stresses (hypoxia), and may be dependent on EC survival factors, like Ang1, to attenuate the development of PAH. Methods. Ang/Tie2 gene expression was assessed in rats exposed to hypoxia (10% O 2) for 1, 3, or 7 days. In a separate experiment, cell-based gene transfer of Ang1/Ang2 was performed and their effects evaluated in hypoxia-induced PAH. Results. Hypoxia induced significant early increases in RVSP and RV/(LV + S), with a significant decrease in Tie2 expression. Hypoxic rats receiving Ang1 demonstrated significant improvements in RVSP and RV/(LV + S), with a partial normalization in Tie2 protein levels. Conclusions . Decreased activity of the Tie2 pathway upon hypoxia may contribute to PAH, possibly by loss of EC survival signaling, which can be overcome by Ang1 gene transfer.
Dynamic response of architectural glazing subject to blast loading

In this thesis, the response of architectural glazing to blast loading is modelled using an explicit dynamic finite element model coded into a computer program. It allows for simulation of monolithic, laminated and insulated glazing and is capable of predicting glazing displacements and stresses up to cracking of the glass. Glass failure is defined using either a failure stress criterion or a probability-based glass failure prediction model. In addition, a variety of support conditions are available along with three different methods of specifying the blast load. The software is also capable of predicting the hazard level associated with a particular combination of glazing and blast load. A secondary goal of the research was the determination of the dynamic strength of window glass by testing the material with a Split Hopkinson Pressure Bar and comparing the results to those from static tests.
Software model-checking: Benchmarking and techniques for buffer overflow analysis

Software model-checking based on abstraction-refinement has recently achieved widespread success in verifying critical properties of real-world device drivers. We believe this success can be replicated for the problem of buffer overflow detection. This thesis presents two projects which contribute to this objective. First, it discusses the design and construction of a buffer overflow benchmark for software model-checkers. The benchmark consists of 298 code fragments of varying complexity capturing 22 buffer overflow vulnerabilities in 12 open source applications. We give a preliminary evaluation of the benchmark using the SatAbs model checker. Second, the thesis describes the implementation of several components for supporting buffer overflow analysis in the YASM software model-checker.
Introduction of structural perturbations into drug polymers: effect on enzyme hydrolysis

Antimicrobial agents have been incorporated into devices in an attempt to address bacterial infection. This thesis furthers the work done on the development of biodegradable polyurethanes with reduced hard segment packing and potential antimicrobial properties. Drug polymers having norfloxacin were synthesized with diisocyanates having pendant methyl (2,2,4-trimethyl-1-6-diisocyanatohexane) and ester (lysine diisocyanate) groups on their backbone and a polycarbonate/polyester soft segment. The surface and bulk properties of the polymers were characterized. Degradation studies, performed in the presence of the enzyme cholesterol esterase, were assessed by high performance liquid chromatography (HPLC) and mass spectrometry (MS). One of the polymers degraded to release drug without any other drug derived products in the presence of enzyme. The results indicate that the presence of diisocyanates with pendant groups alter the degradation profile of the drug polymer, suggesting that an ideal drug release profile can be achieved by modification of the polymer chemistry.
Community partnerships that include people with disabilities: power, culture and values

Partnerships have been proposed as an empowering method of addressing a variety of disability-related issues in fields such as health, research, technology design, and policy development. However, people with disabilities remain frustrated by a lack of power sharing. This study examined the involvement of people with disabilities in community partnerships. In particular, the impact of social constructions of disability (medical, charity and independent living) and beliefs regarding knowledge were investigated. Dominant power structures and how they were internalized, accepted or challenged were also examined. This study incorporated elements of both participatory action research and critical pedagogy. Two groups of multiple stakeholders were observed during their involvement in intensive 4.5 and 3-day workshops designed to explore and facilitate partnership development. Six participants from each of these workshops then engaged in an in-depth, semi-structured interview about their experience and ideas related to disability and partnership. Ten disability leaders involved in community partnerships across Canada were then brought together over a 4-day period to explore themes derived from the earlier interviews. Through creative methods including story telling, role play, and metaphor analysis, participants verified and elaborated upon these themes and tested their applicability within a variety of settings. These participants were involved in pre and post interviews and discussions were tape recorded. People with disabilities reported that they felt their capacities and contributions were often devalued and that their full participation was systematically hampered by commonly held beliefs about expertise, communication and work. The act of representing people with disabilities in a partnership was described as challenging because of the diverse nature of the group and internalized discriminatory practices. Benefits of partnerships and suggestions for supporting them were also documented. Partnerships were found to frequently replicate elements of oppressive relationships and on occasion, foster the development of innovative collaborative relationships. Without challenging the dominant relations of power and beliefs that affect the interactions and outcomes of partnerships, people with disabilities may experience partnerships as oppression. This study suggests a need for all partners to develop a greater awareness of power, accept responsibility for reducing barriers, and work to create new ways of relating.

Keywords: People with disabilities, Social conditions
People with disabilities, Services for
Community organization
Electrostatic collimation of aerosols and the enhancement of fine particle sampling

A multitude of inertial sampling methods currently permit the selection of nearly any size of particle from the gas phase of an aerosol. Despite their success and high efficiency, these systems are challenged by intrinsic restrictions on operating pressures and flow rates, which necessitate designs that are sometimes extreme in their complexity and physical requirements. This work proposes the use of electrostatic methods as a promising alternative, and presents several novel designs for charge-based selection. A series of recommendations for future applications of electrostatic selection methods is offered in conclusion. A pilot study developed and tested a prototype electrostatic aerosol concentrator with very promising initial results, including a highly desirable inversion of the performance curve, and strongly recommends the further development of additional novel applications of electrostatic selection methods. A novel design for a corona particle charger was coupled with an electrostatic lens to produce a prototype electrostatic aerosol collimator. This charge-based sampling system was used to generate an aerosol beam from airborne particles. The beam produced was more acute (less than 350 microns in diameter) than any inertial beam reported to date. Furthermore, the performance of the ES collimator reversed the size bias of the inertial collimator, and preferentially sampled smaller particles. Using ions as an analog for ultrafine particles, a novel electrostatic lens was produced to demonstrate the advantage electrostatic methods offer over inertial sampling. The lens also provided a 100-fold improvement over existing ion sampling technology and was used to collimate ion source currents ranging from 30 pA to 7 nA, increasing the ion signal strength at the target by factors of 20 to 130 times that of the unaided signal. The inertial collimator commonly used in online aerosol sampling displays the size-dependent particle selection characteristic of all mass-based sampling methods. In this work, a custom-built inertial aerosol collimator illustrated this inherent size bias using a procedure specially developed to visualise sampling behaviour. By this means, the inert ially-generated aerosol beam was found to display a highly size-dependent radial distribution of its constituent particles. The observed tendency for particles to retain their collimation was limited to those larger than one micron in diameter.
Nitric oxide inhibits stretch-induced MAPK activation in mesangial cells through RhoA inactivation

Glomerular capillary hypertension is an important determinant of glomerulosclerosis in chronic renal failure. Its simulation by cyclic mechanical strain in vitro activates Erk and induces actin stress fibers (ASF) in mesangial cells (MC). Nitric oxide (NO) limits glomerular injury and abrogates strain-induced Erk activation through cytoskeletal disassembly. In primary MC, strain activated RhoA, an important cytoskeletal regulator; Raf-1/Erk activation temporally followed. Rho-kinase inhibition prevented Raf-1/Erk activation and ASF formation. RhoA inhibition similarly inhibited Erk activation. NO and cGMP inhibited stretch-induced RhoA, Raf-1 and Erk activation, and ASF formation. MC infection with a NO-resistant RhoA mutant abrogated NO and cGMP effects on Erk activation and ASF formation. Early RhoA activation is thus essential for stretch-induced ASF formation and Raf-1-Erk activation, events prevented by NO and cGMP through their action on RhoA. Thus, RhoA inhibition may provide a new therapeutic approach to, hemodynamically-mediated glomerular injury.
Numerical simulation of the ejector flowfield in a ram rocket engine with multiple rockets

Analysis shows that evenly distributing the rocket exhaust throughout the entrained air enhances mixing, but does not assure sufficient energy transfer or air entrainment. Examination of the ejector performance from Case-to-Case allows an iterative enhancement process resulting in a performance-balanced ejector. Humanity's access to space is limited to the rocket, restricted by its massive onboard supplies of oxidizer. The ram rocket is a potential alternative. It offers enhanced performance and reduced takeoff weight. Performance is directly related to the amount of air entrained, mixing uniformity of rocket and air flows, and the transfer of energy between them. An ejector configuration by Sislian consisting of two "suspended" annular rockets in an annular ejector is examined. Several Cases are studied by modifying rocket locations and relative sizes. Held constant are the flow parameters and the relative size of total rocket exit area to ejector area. Comparisons are made to Etele and Daines.

Keywords: Combustion engineering, Mathematical models
Rocket engines
Fluid dynamics, Mathematical models