VictorJuiz/thesis huggingface dataset:
Control of esophageal body and lower esophageal sphincter contractility: regional differences in esophageal smooth muscle

Peristaltic contractions are considered to be the result of the local muscle responding passively to neural signals. However, when adequately stimulated in the face of neural blockade (with tetrodotoxin), single or repetitive contractions can traverse the smooth muscle (SM) esophagus at velocities similar to primary peristalsis. Therefore in the esophagus, myogenic properties are present that could contribute to the regulation of muscle contraction patterns. This thesis explored the hypothesis that in the cat esophagus, muscle properties, especially if regional differences exist, hold the potential to impact on the nature of esophageal contractions and the responses of the muscle to its innervation. Within the LES there are regional differences in muscle biomechanical properties, calcium handling and ion channel expression. LES CM develops greater spontaneous tension than sling, yet sling muscle demonstrates a much greater response to cholinergic excitation. Maintenance of LES tone and tension development in response to cholinergic stimulation in both muscles is due to release of calcium from intracellular stores. The level of tone is in large part regulated by extracellular calcium entry. These studies are the first to identify L Ca in LES circular and sling muscle electrophysiologically and the channel protein expression in these tissues. LCa current density and channel protein is greater in the CM and is consistent with the dominance of L Ca influx pathways for contraction in circular but not sling muscle. Along the length of the circular SM esophageal body (EB), there are regional differences in muscle biomechanical properties and ion channel expression and ion channel modulation by acetylcholine (ACh). Muscle from the proximal region develops greater tension with stretch and cholinergic stimulation than the distal region. L-type calcium channel (LCa) current density and protein expression is greater in proximal cells and these differences are shown to impact on contraction amplitude. Novel modulation of LCa with the SNARE protein SNAP-25 is examined. This study also demonstrates that ACh-induced activation of large conductance calcium activated potassium channel (BKCa) current in the EB is greater in cells from distal SM esophagus. Taken together, these regional differences are consistent with aboral propulsion of the bolus.
Diversification of C4 photosynthesis in the eudicots: Anatomical, biochemical and physiological perspectives

C4 photosynthesis is a means evolved to suppress photorespiration by concentrating CO2 around Rubisco. It occurs in 19 angiosperm families, three monocot and 16 eudicot. Compared with C4 monocots, C4 photosynthesis is rare and phylogenetically sporadic in eudicots reflecting repeated origins for numerous C4 eudicot lineages. Anatomical, biochemical, and physiological patterns for many C4 species of these lineages are enigmatic. The present thesis resolved three main research topics:1. The diversity of Kranz anatomy and biochemistry in a total of 33 C4 eudicot species, including 13 previously uncharacterized taxa, representing 13 families and belonging to a range of taxonomic groups, was explored. Four Kranz types and two biochemical subtypes occurring in various combinations were found. The frequency of these combinations occurred in the order: Atriplicoid NADP-ME> Atriplicoid NAD-ME> Salsoloid NAD-ME = Salsoloid NAD-ME> Kochioid NADP-ME = Kochioid NAD-ME> Suaedoid NAD-ME. A quantitative anatomical study comparing the C4 groups with a C3 group of 21 related species showed insignificant differences between C4 and C 3 types in vein density and leaf thickness, but significant differences in: the proportions of mesophyll, bundle sheath, and epidermis tissues, intercellular airspace, mesophyll to bundle sheath ratio, bundle sheath surface area to volume ratio, and proportion of bundle sheath surface area exposed to intercellular airspace. No significant differences between the C4 biochemical subtypes were found. A multivariate canonical discriminant analysis segregated the C4 subtypes from the C3 type by mesophyll to bundle sheath ratio and exposure of the bundle sheath surface to intercellular space. Discrimination between the C4 subtypes was insignificant. This study expanded knowledge of Kranz anatomy and biochemistry in C4 eudicots and presented striking examples of convergence and divergence in C4 evolution.2. Investigation of convergent evolution of Kranz anatomy in two unrelated woody C4 eudicot lineages (Calligonum vs. Haloxylon). These lineages diverged in the C4 biochemistry and CO2 response despite the convergence on similar life form, growth habit, and pattern of Kranz anatomy.3. Leaf anatomical and GDC localization studies with eight Heliotropium species (Boraginaceae; section Orthostachys) revealed that C3-C4 intermediates exist in the genus. The species exhibited Kranz-like anatomy accompanied by GDC confinement to the bundle sheath. The work with Heliotropium identifies novel C3-C4 intermediates, thereby providing a new "model" genus for the study of C4 evolution.
Bacterially synthesized folate and supplemental folic acid are absorbed across the large intestine of piglets

The objective of this study was to see if bacterially synthesized folate and supplemental folic acid are absorbed across the large intestine of piglets. [3H] folic acid or [3H] PABA was injected into the cecum of piglets. In piglets injected with [3H] folic acid the feces, liver, urine and kidneys accounted for 82.1, 12.3, 3.9 and 1.7% of the total recovered [3H] folate, respectively. In piglets injected with [3H] PABA, the amount of bacterially synthesized folate found in the feces, liver and urine accounted for 85.1, 0.4 and 14.6% of the recovered amount. Our results indicated that both bacterially synthesized folate and supplemental folic acid are absorbed across the colon and incorporated in the host's tissues. The amount and form of folate present could potentially impact whole body status as well as colonic health.
How elementary principals assist teachers in implementing computer technology in mathematics

The purpose of the research was to explore how elementary principals assist teachers in implementing computer technology in mathematics. The research was an in-depth qualitative study utilizing the case study method. The study was conducted in three elementary schools in a large urban school board over four-months. The main participants were principals, vice principals, teachers, support staff, and a superintendent. Interviews, observations, and field notes were the main data collection tools. For principals there are several implications. The integration of computer technology into mathematics requires more than an infrastructure including hardware and software. Principals, together with their staff, have to envision the potential of computer technology for the teaching and learning of mathematics. They need to have a common understanding of what is meant by computer technology integration and understand how computer technology can be used to support constructivist teaching in mathematics. It is beneficial for principals to have a full understanding of the levels of technology integration and how they can assist teachers as they progress through the various stages. In addition to creating supportive conditions, principals need to cooperatively plan with teachers for mathematics and determine how computer technology can effectively support instruction. The five major findings suggest important considerations for an elementary school principal in the implementation of computer technology in mathematics. (1) The role of the elementary school principal was found to be central in assisting and supporting teachers in the integration of computer technology in mathematics. (2) Principals create supportive conditions, which foster the use of computer technology for mathematics. (3) The study suggests principals are advocates for new computer technology initiatives to support the mathematics curriculum. (4) This research identified that principals need to know, understand, and be able to apply appropriate assessment and evaluation strategies for assessing the use of computer technology for the teaching and learning of mathematics. (5) The superintendent of schools was found to model and directly influence curriculum management processes for principals for the implementation of computer technology in mathematics.

Keywords: Mathematics, Computer-assisted instruction
Teacher-principal relationships
Elementary school principals
Optimization procedure for rating calculations of unequally loaded power cables

This thesis addresses the problem of finding ampacities of underground cables. Although standard methods in the literature for solving this problem provide satisfactory results, however, these values are not always optimal and the algorithms are not always convergent. This thesis takes these standard methods as a starting point and formulates the ampacity calculations as an optimization problem. The solution to this optimization problem gives required ampacities, and is determined by utilizing the barrier method algorithm. This algorithm is implemented in FORTRAN-77 and used to obtain ampacity solutions for various cable configurations. The results are compared with ampacities obtained with standard methods, implemented in the CYMCAP commercial software package. The comparisons show that ampacity solutions obtained with the proposed method are at least equal and up to 10% greater than those obtained with the latter. Such an increase in total current loadings greatly improves the utilization efficiency of power cables.
Clinical teaching and clinical outcomes

The focus of this thesis is to test for a difference in clinical outcome for patients treated by high rated clinician teachers compared to those patients treated by low rated clinician teachers. The hypothesis is that patients cared for by better clinician teachers have better clinical outcomes. We performed a retrospective cross sectional study to explore the association between Teaching Effectiveness Scores of 40 clinician teachers at the University of Toronto and the clinical outcomes of 4377 of their patients over a 3 year period. The main analysis compared mean hospital length of stay for patients cared for by physicians above and below the mean Teaching Effectiveness Score. We looked at four of the most common admission diagnoses to a General Internal Medicine ward and our overall findings show no major difference in outcomes. The conclusion is that there is no large correlation between Teaching Effectiveness Scores and clinical outcomes.
Multigrid methods for forward and inverse resistivity problems in geophysics

In forward resistivity modelling, conventional multigrid solvers have difficulty in representing the physics of an arbitrary distribution of electrical conductivity on very coarse grids. In general, traditional coarsening methods for discrete conductivity models cannot represent, at a coarse grid level, the effective structural conductivity anisotropy, which results from fine structure in the model. These coarse grid limitations are particularly damaging to multigrid solvers when a coarse cell is obliged to represent fine structure containing high conductivity contrasts. I have developed a variation of the usual resistive-network representation of the 2D continuum which avoids these problems, and have compared it to the traditional resistive-network currently used. In this variation, the usual five-point Laplacian stencil used on a finite-difference grid was replaced with a nine-point stencil, and the conductivity scalar was replaced with a 6 parameter conductivity parameterization. In addition to resistivity forward modelling, I examined two methods for solving the inverse resistivity problem. In the first method, both forward and inverse solutions are obtained simultaneously by relaxing the conductivity model parameters in tandem with the potentials. Implementing such an inverse solver in a multigrid method could, in principle, obtain a solution to the inverse problem in time that is linearly proportional to the number of model parameters. However, this approach suffers from convergence problems which were not resolved. The second approach to the inverse problem uses a multilevel method in which approximate solutions for both the forward and inverse problems are obtained on a coarse grid and gradually refined until a desired fine grid is reached. The inverse portion of this algorithm utilizes the standard iterative damped least-squares method that is solved with a bi-conjugate gradient method. Results are presented for three standard geophysical models and compared with the results obtained from a standard single grid inversion method. In addition to a substantial speed-up over the single grid inversion method, the multilevel inversion method distributes the model over a greater depth range, without coercion by weight functions. This gives more realistic solutions to the inverse problem than the unweighted single grid inversion method which tends to concentrate the solutions near the surface.
Successful strategies to generate community involvement in solid waste management: Three case studies in the Philippines

This thesis presents three success stories in solid waste management in the Philippines which focused on approaches toward community participation. Two cases highlighted the local government efforts in the conversion of the open garbage dumpsites into a waste processing zone i.e. the Controlled Waste Disposal Facility in Payatas, Quezon City, Metro Manila, and the Eco-Waste Processing Center in Los Banos, Laguna. The other case was an information, education and communication-based project of the author in Barangay Masili, City of Calamba, also in Laguna, with emphasis on community consciousness in solid waste segregation for a cleaner environment. Solid waste is one of the country's major issues confronting the community and the local government units. The legislation of RA 9003, the Ecological Solid Waste Management Act in 2001, addressed this phenomenon by calling for the involvement of all sectors, primarily the local authorities together with the community. This research examines the commonality and uniqueness of the strategies employed to encourage people's mobilization in managing solid waste. It was found that participation starts from a deepening awareness of people about the problems affecting them, getting involved, and becoming responsive when they understand its potential benefits. Participation is deeply anchored in political mobilization where leaders take the initiative and the will to make a difference in the community. Strong advocacy in the furtherance of community awareness and consciousness in relevant programs together with the stakeholders' partnership and networking play a very important role.

Keywords: Refuse and refuse disposal, Management
Refuse and refuse disposal, Philippines
Refuse and refuse disposal, Management
Refuse and refuse disposal, Philippines
Bayesian model checking: prior-data conflict

In this thesis we study model checking procedures in statistical analysis. To validate any inferences drawn in a statistical analysis it is essential that the inputs chosen by the analyst be deemed appropriate for the data. In the Bayesian context these inputs consist of both the sampling model and the prior. We thus distinguish between two possibilities of failure of the Bayesian model: the data may have not arisen from the sampling model, or the prior may place most of its mass on parameter values that are not feasible in light of the data. We refer to the latter here as prior-data conflict. We examine how to assess whether or not a prior-data conflict exists and how to assess when its effects can be ignored for inferences. We developed a method for checking for prior-data conflict that works for a wide variety of models and priors. Further, we developed some diagnostic tools for ignoring prior-data conflict. In addition we consider method for checking for the source of any prior-data conflict in cases where the priors are specified component-wise. The concept of prior-data conflict is seen to lead to a number of new developments, including a role of ancillary statistics in Bayesian analysis, and for a partial characterization of noninformativity of a prior or a sequence of priors. The methods presented in this thesis leads to a factorization of the joint distribution of the data and the parameter that suggests a logical separation between the activities of checking the sampling model, checking for prior-data conflict and inference about the model parameters.
Current density imaging at the tip of a catheter

Low Frequency Current Density Imaging was done at high resolution about the tip of an electric dipole constructed from a rigid coaxial cable. Artifacts were present because the method proved sensitive to misalignments smaller than the available precision. Furthermore, large local current densities occurred and exceeded safe specific absorption ratios. The dipole was turned into a loopless receive coil so that its electrodes could be used to deliver current and receive magnetic resonance signal simultaneously. This setup suffered signal reception voids that made doing Current Density Imaging impossible. Imaging using the dipole as a loopless receive coil did enable the calculation of the current density that would emanate from the dipole if a radio frequency current were applied to across its terminals. This was done using Reciprocity Current Density Imaging which is derived here for the first time and presented alongside experiment results.
Temporal and spatial patterns of zooplankton abundance and productivity in Lake Erie using an Optical Plankton Counter

Distributions of crustacean zooplankton in Lake Erie were examined in 1998 and 1999 with an Optical Plankton Counter (OPC). Chapter 1 provides a new calibration of the OPC for use in freshwater and contrasts it with a previously developed calibration. Chapter 2 provides the first ever reported use of an OPC to examine seasonal dynamics of freshwater zooplankton. I found higher crustacean abundance and biomass (2–3x) in the central basin than the eastern basin during both years. Seasonal peak abundance and biomass occurred during June 1998 in both basins however during 1999 the east basin peak was not observed until July. Spring samples were dominated by cyclopoid copepods which gave way to large numbers of cladocerans in June which were in turn replaced by copepods, mostly calanoid copepods, in the summer and fall in both basins. Although the early season cladoceran peak in abundance and biomass is consistent with historical patterns in the lake it appears that there has been a shift to smaller Bosmina species from the large Daphnia species that were common during 1983–1987. Seasonal production estimates derived from the OPC samples are consistent with independent estimates using the egg ratio technique and indicate much greater production in the central basin than in the east basin during 1998 and 1999. Chapter 3 provides an overview of three commonly used techniques for spatial data analysis (Autocorrelation, Spectral Analysis, Wavelets) and one new technique (Principal Coordinates of Neighbour Matrices). I tested each technique on simulated data sets consisting of simple known spatial structure, complex known spatial structure, and real data with unknown spatial structure. All methods were able to identify the simple structures when presented in isolation, however the autocorrelation technique was unable to identify small-scale structure when present along with larger scale structure. Chapter 4 examines spatial structure in crustacean zooplankton of Lake Erie. Zooplankton showed patchy distributions at all spatial scales ranging from 7.5m to 10 000m. Principal Coordinates of Neighbour Matrices (PCNM) analyses revealed that most predictable repeating structure in both zooplankton biomass and chlorophyll biomass was restricted to spatial scales in excess of 504m regardless of the time of year. At these scales structuring mechanisms are likely physical in nature and relate to broadscale circulation patterns. The ability of the PCNM model to describe spatial structure varied seasonally with the lowest amount of variability being explained during mid-summer (July cruises) in both years. Total variance increased with depth as zooplankton distributions became patchier. (Abstract shortened by UMI.)
The effects of milk proteins on the regulation of short-term food intake and appetite in young men

The hypothesis tested was that milk proteins differ in their capacity to suppress subjective appetite and short-term food intake in young men and these differences associate with their effect on plasma amino acid, glucose and insulin concentrations. Two experiments were conducted. Casein, whey and complete milk protein were given at 0.7g protein/kg weight. Subjective appetite was measured and blood samples collected for analysis of amino acid, glucose and insulin concentrations until pizza meals were provided at 90 (Exp1) or 150 min (Exp2). It is concluded that milk proteins suppress short-term food intake and they differ in their capacity to do so over time. Protein treatments decreased test meal intake at both 90 and 150 min. Food intake was similar among protein treatments at 90 min, but at 150 min casein suppressed food intake more than whey. Food intake was not associated with subjective appetite, amino acid, glucose or insulin concentrations.
Proteomics in an animal model of insulin resistance and metabolic dyslipidemia

Dyslipidemia results from the hepatic overproduction of apoB-100-containing very-low-density lipoprotein (VLDL) and apoB-48-containing chylomicrons from enterocytes. Here, a fructose-fed hamster model of insulin resistance is used to develop a proteomic profile of protein factors in the secretory pathway that are altered in response to the onset of insulin resistance. Lipoproteins are assembled in the ER and Golgi apparatus of hepatocytes and enterocytes. We have profiled ER- and Golgi-associated proteins from insulin resistant and control hepatocytes and enterocytes, with the intention of identifying proteins involved in insulin signaling attenuation and lipoprotein overproduction. Differentially expressed in the hepatic secretory pathway with fructose-feeding, were cellular chaperones and proteins involved in oxidative stress. In the enteric ER, fructose-feeding caused the differential expression of proteins involved in glucose metabolism. These findings have increased our understanding cellular responses accompanying the onset of insulin resistance and metabolic dyslipidemia.
Combined concentration gradients of neurotrophic factors act in synergy to guide neurite outgrowth

Neurotrophic factors present as concentration gradients are neurotropic cues that direct axonal growth toward their targets. Multiple factors work together to ensure axons reach the proper targets, likely interacting with one another via intracellular signalling pathways. Nerve growth factor (NGF) and neurotrophin-3 (NT-3) are neurotrophins known to guide axons as well as to promote axonal growth following injury to the spinal cord or peripheral nerve. The receptors for these growth factors were shown to be co-localized on E10 chick dorsal root ganglion (DRG) cells, providing an opportunity for synergism. Gradients of NGF and NT-3 were immobilized in a cell-invasive, cell-adhesive scaffold made from 15% poly(2-hydroxyethylmethacrylate) [p(HEMA)]. A minimum NGF concentration gradient of 310ng/ml/mm was required to guide chick DRG neurites, which was consistent with previous results. A lower concentration gradient of 200ng/ml/mm of NGF was shown to elicit guidance when an NT-3 concentration gradient of 200ng/ml/mm was also present, indicating a synergistic response.