VictorJuiz/thesis huggingface dataset:
Circadian organization of diving behaviour and respiratory chemoreflexes in birds

The circadian rhythm in diving behaviour of captive canvasback ducks Aythya valisineria was measured using radio-telemetry, and indirectly via analysis of underwater feeding activity. The asphyxic ventilatory response then was measured in awake unanesthetized ducks by closed-circuit plethysmography at the times corresponding to maximum and minimum dive activity. 76% of dives occurred at night and nocturnal dives were 37% longer than those performed in the light. The day-night differences in diving behaviour were apparently correlated with day-night differences in respiratory chemosensitivity. The ventilatory response to progressive asphyxia was non-linear, and consisted of an increase in tidal volume with no change in respiratory frequency. Respiratory sensitivity to asphyxia, as reflected by the exponential regression coefficient (the slope of lnV$\sb{\rm I}$ versus (CO$\sb2$)), was lower at night than during the day (P = 0.02). I suggest that underwater exercise performance is facilitated by reduced respiratory chemosensitivity and that the respiratory and behavioural control systems are synchronized by the circadian timing system.
Ultrashort optical pulse interaction with fibre gratings and device applications

The linear interaction between (coherent) ultrashort broadband optical and fibre gratings, referred to as the ultrashort pulse response of fibre gratings, is theoretically and experimentally investigated. The reflected and transmitted pulses of an ultrashort pulse incident upon a fibre grating are calculated using coupled-wave theory. The effects of different grating characteristics, such as grating strength, phase response (dispersion), chirp, and apodization on the ultrashort pulse response are examined. A symmetric transform-limited 1-ps Gaussian pulse is assumed as the ultrashort broadband input to the gratings; the reflected and transmitted pulses take on significantly different shapes and vary in duration. The prominent features observed are qualitatively explained in order to gain physical insight into the dynamics of the ultrashort pulse response. To experimentally verify the theoretical calculations, the temporal response of transform-limited picosecond pulses reflected and transmitted from a fibre Bragg grating is measured using a surface-emitting nonlinear semiconductor multi-layer waveguide as an optical correlator. The results of the theoretical study indicate that there is the potential for a new class of devices and applications for optical communications by combining ultrashort broadband pulses and fibre gratings. In particular, a multiple-grating fibre device structure that can decompose an ultrashort broadband pulse simultaneously in both wavelength and time domains is designed, demonstrated, and its uses in optical communications are outlined. Other applications, including temporal pulse shaping and the implementation of optical code-division multiple access are also discussed.
The relationships between dyspnea, physical activity, and fatigue in patients with chronic obstructive pulmonary disease

A descriptive-correlational design was used to examine the relationships between dyspnea, physical activity, and fatigue in patients with chronic obstructive pulmonary disease (COPD). Lazarus and Folkman's (1984) theory of stress, appraisal, and coping provided a framework to guide the study. Dyspnea was measured by a vertical visual analogue scale, fatigue by the Profile of Mood States-Fatigue subscale, and physical activity by the 6 minute walk (6MW) test and an open ended question. A convenience sample of 7 male and 15 female patients with COPD provided data for analysis. The sample was characterized by relatively high FEV1 indicating mild lung impairment, predominantly female, and high mean levels of fatigue and dyspnea. No significant gender difference was found in the ratings of dyspnea and fatigue and the 6MW distance. Controlling for FEV1, dyspnea, physical activities, and fatigue were all significantly interrelated (P $<$ 0.001). Results indicated that the higher the dyspnea scores, the shorter the 6MW distance walked, and the higher the fatigue scores. Limitations and suggestions for nursing practice and future research were presented.
The influence of nutrients on floc physicochemical properties and structure in activated sludge processes

The influence of nutrient levels (COD:N:P) on floc properties was studied using a laboratory sequencing batch reactor (SBR) system fed a glucose based synthetic waste. Floc physicochemical properties characterized included size settling velocity, density, porosity, and the compositions of extracellular polymeric substances (EPS). Floc structural analysis involved a minimal perturbation approach and correlative microscopy (CM). Various nutritional conditions were investigated: nutrient rich (Run 1), nutrient starved (Run 2), and nutrient limited (Run 3 and 4). Nutrient rich conditions (COD:N:P of 100:10:1, 100:5:2, 200:5:1) did not improve system performance and had no effect on floc sizes, settleability and floc morphology. Lack of N and P resulted in a deterioration of system performance. The deficiency in P resulted in an initial increase in floc sizes and settleability, but prolonged P-limited condition decreased settleability and density, although the floc sizes were still large and COD removal efficiency was good. The N-limited condition did not affect the system performance but affected floc settleability and size. Correlative microscopy (CM), including transmission electron microscopy (TEM), scanning confocal laser microscopy (SCLM) and conventional optical microscopy (COM), revealed heterogeneity in the EPS and distribution of the cellular and bioorganic components. The EPS in the flocs was shown to have differences in composition and spatial distribution. Total carbohydrates and protein were the major components of EPS. Under the P-starved condition, the concentrations of carbohydrates, protein and DNA of EPS increased. A similar trend was observed for the P-limited condition, but an increase in acidic polysaccharides was also detected. The N-limited condition resulted in a significant decrease of protein and DNA concentrations. The presence of Fe, S, and P within the EPS of flocs was detected by TEM and energy dispersive spectroscopy (EDS). (Abstract shortened by UMI.)
Development of an oral microspherical formulation for bimodal in vitro release of theophylline

In vitro drug release from TheoDur$\sp{\circler}$ tablets was studied in various environments and the effect of viscosity, initial drug concentration as well as the rate of agitation was investigated. Matrix microspheres, with high drug loading, based on copolymer of methyl methacrylate/methacrylic acid (MMA/MAA), have been produced by the solvent removal microencapsulation process. The effects of various processing parameters, including surfactant concentrations and compositions, drug particle size as well as stirring rate during the microencapsulation process were examined. The swelling kinetics, release kinetics and release mechanisms were studied. The microspheres underwent swelling and erosion upon solvent ingress. Drug release was controlled by swelling at earlier stage and diffusion at later stage. Several models for diffusional release were used to fit the data. Surface morphology by scanning electron microscopy revealed porous characteristics. The microspheres were incorporated into larger polymer beads composed of copolymer of acrylic and methacrylic acid esters with a low content of quaternary ammonium group (Eu-RL). In vitro release studies from such a system revealed bimodal drug release pattern. This pattern is proposed to be beneficial in adapting to the dynamic environment of the GI tract.
A thermodynamic analysis of evaporation waves in an expanding jet

In this work, a thermodynamic analysis of flashing evaporation waves was performed. Specifically, the analysis focused on the expansion of dodecane through a converging nozzle. Properties of the fluid were calculated using the modified Simonet-Behar-Rauzy equation of state. The flow model consisted of an isentropic expansion to a superheated liquid state, followed by evaporation across a cylindrical discontinuity. Sonic and subsonic flow conditions were alternately considered for the downstream, equilibrium state of the discontinuity. The outward flow from the discontinuity was modeled as radial and isentropic. In the sonic case, the model predicts overexpansion of the fluid to a normal shock wave and subsequent stagnation to the injection chamber pressure. Simple stagnation was proposed for the subsonic case. Model predictions for the mass flow rate, extent of evaporation across the discontinuity and shock location are compared to experimental evidence.
Gender differences in friendship selection and friendship quality of children with and without learning disabilities

This study was an investigation of gender differences in friendship selection and friendship quality in children with and without learning disabilities (LD). The participants were 110 children in grades 4 to 6, 55 of whom had identified learning disabilities. They participated in a structured individual interview about their best friends. Parents, teachers and friends were given an adapted version of this interview. Analyses revealed significant gender differences in friendship nominations which were corroborated by parents and/or reciprocated by peers. Boys with LD were more likely to nominate friends who were younger, family members, and outside of their school. Girls with LD were more likely to interact with their friends on the telephone and at home, while boys with LD were more likely to interact with their friends in the neighbourhood. The quality of friendships reported by children with and without LD differed on the dimensions of conflict and betrayal and conflict resolution, but no significant gender differences were found.
Enabling dependence analysis in C

Dependence analysis is a fundamental tool used in many compiler transformations which optimize and parallelize scientific code written for high-performance vector and parallel computer architectures. Implementing dependence analysis for the C programming language is difficult because of complications caused by nonstandard control flow and use of pointers to reference arrays. In order to enable dependence analysis in C, code can be preprocessed to convert loops which violate FORTRAN-like conventions into a canonical form which can be processed successfully by the dependence analyzer. We developed two algorithms to enable such processing. Loop control flow normalization (LCFN) normalizes loop control flow and array reference subscripts. Pointer array access normalization (PAN) recovers implicit array references through pointers. A prototype implementation of the LCFN and FAN methods was built using the Parafrase-2 compiler. Experimental results generated using the SPEC95 and NAS benchmark suites showed that these techniques can successfully enable dependence analysis.
Attentive object recognition in the selective tuning network

A hierarchical winner-take-all network derived from the selective tuning model (Tsot-sos et al., 1995) allows position-invariant object recognition via selective attention. A notion of cooperation between features is introduced into the selective tuning winner-take-all framework to consider the spatial relationship between features when selecting winners. The model is demonstrated with example recognition networks in which objects are represented as hierarchical conjunctions of parts and features culminating in the activity of one unit. It is shown that the attentional beam that follows from the selection of such an object unit tightly encompasses the object in the image. It is also shown that topdown inhibitory bias signals allow the selection of objects having particular low-level features. The robustness of the behaviour is investigated with a large number of images containing one or two automatically-generated figures.
The effect of inhibitors of oxidative phosphorylation on the Drosophila heat shock response

The heat shock response allows cells to cope, at molecular level, with environmental and pathophysiological stresses. It is a highly conserved and universal response. Inhibitors of oxidative respiration are but one class of chemicals that can induce the heat shock response. In order to gain insight into the mechanisms and pathways involved in activation of the heat shock response, different inhibitors of oxidative respiration: sodium salicylate, 2,4 dinitrophenol (DNP) and potassium cyanide (CN$\sp-$) were examined in detail. It was found that all of these drugs dramatically reduced the level of cellular ATP in Drosophila tissue culture cells, and that this decline in ATP correlated with the activation of the heat shock response as measured by HSF binding and heat shock gene induction. However, one of these agents, sodium inducing some aspects of the heat shock response did not induce heat shock gene transcription. It suggested that decreased ATP levels can, at least in part, serve as the cell's stress response machinery, and that this may be one of the means by which certain inducers of the heat shock response act.
Image processing for skin cancer detection: Malignant melanoma recognition

In order to achieve an effective way to identify malignant melanoma at an early stage without performing any unnecessary skin biopsies, digital image analysis of the images is investigated. For the detection of malignant melanoma, appropriate analyses are done on the tumor images according to the clinical characteristics that early melanoma possesses. In the last stage, classification is done based on the results obtained from the above mentioned analyses. The tumors are classified as either "potential malignant melanoma" or "non-melanoma". This can reduce the time spent and pain received by the patients in detecting early malignant melanoma. The major purpose of this thesis is to help in identifying early malignant melanoma and aid in early diagnosis to help to reduce the death rate caused by this deadliest disease.
Enzymatic conversion of 6-[¹§8F]-fluorodopamine to 6-[¹§8F]-fluoronorepinephrine by dopamine ß-hydroxylase

The visualization and investigation of the sympathetic innervation of the heart with positron emission tomograyphy has become a new and active area in nuclear cardiology. Potentially, it has been suggested that the use of 6- ($\sp{18}$F) -fluorodopamine (6-$\sp{18}$FDA) and ($-$)-6- ($\sp{18}$F) -fluoronorepinephrine (($-$)6-$\sp{18}$FNE) may provide quantitative kinetic information on the utilization of the native adrenergic neurotransmitter, norepinephrine. It was found in this study that 6-$\sp{18}$FDA could be converted into ($-$)-6-$\sp{18}$-FNE stereospecifically by the enzyme dopamine $\beta$-hydroxylase (D$\beta$H), which is responsible for the biosynthesis of endogenous norepinephrine from dopamine. The estimated K$\sb{\rm m}$ and V$\sb{\rm max}$ values for the enzymatic activity of D$\beta$H on dopamine were 1.4 $\pm$ 0.3 mM, and 0.079 $\pm$ 0.017 $\mu$moles/unit/min, and that on 6-$\sp{18}$FDA were 0.86 $\pm$ 0.06 mM, and 0.024 $\pm$ 0.003 $\mu$moles/unit/min, respectively. The differences between the K$\sb{\rm m}$ and V$\sb{\rm max}$ values of the two substrates were both statistically significant at P $<$ 0.05. The enzymatic conversion of 6-$\sp{18}$FDA into ($-$)-6-$\sp{18}$FNE may provide an alternative method for synthesizing ($-$)-6-$\sp{18}$FNE for clinical use.
An experimental and numerical study of exothermic dissolution in the nickel-aluminum system

The free dissolution behavior of nickel in aluminum is studied in the temperature range 750-900$\sp\circ$C using a combined experimental and numerical technique. This combined approach determines that mass transfer is solely diffusion controlled through the boundary layer, and the mass transfer coefficient follows an Arrhenius relationship with temperature. Exothermicity increases mass transfer by increasing liquid solubility at the moving boundary. Theoretically derived correlations for Sherwood and Nusselt numbers employing modified Grashof numbers are supported by experimental and numerical evidences.
Cost-effectiveness of strategies for the prophylaxis of Mycobacterium avium complex infection in patients with advanced human immunodeficiency virus disease

Background. Mycobacterium avium complex (MAC) is the commonest bacterial opportunistic infection in patients with Human Immunodeficiency Virus (HIV) infection. Objective. To determine the cost-effectiveness of strategies for MAC prophylaxis for patients with advanced HIV disease. Design. Decision analysis model of advanced HIV, with direct estimates of utilities. Measurements. Utilities were assessed with the standard gamble (SG) method and the time trade off (TTO) method, using standardized descriptors. Patients' own health was rated with the health utilities index (HUI). Results. SG and TTO methods gave similar results for utility estimates. HUI scores were higher and did not differentiate between health states. Azithromycin was the most cost-effective regimen for MAC prophylaxis, and may be cost-saving. The optimal time to initiate azithromycin is between a CD4 count of 100 and 75 cells/$\mu$L. Conclusions. Azithromycin, with sequential rifabutin, is the most cost-effective regimen for MAC prophylaxis in patients with advanced HIV disease.
Effect of viscosity modification by fiber dose and heat treatment on postprandial blood glucose response

The effect of modifying viscosity by psyllium dose and treatment methods on postprandial blood glucose response was tested in healthy individuals (4M + 4F, 33.6 $\pm$ 3.5 years) on 20 occasions. Meals, either untreated or heat-treated, were composed of glucose solution (25g or 50g CHO) with (test) or without (control) supplementation of either 3, 6, or 9g psylliun. Meal viscosity was determined by measuring hardness, which correlated with viscosity (r = 0.98, p = 0.0034). Log hardness of meals, which was directly proportional to dose (r = 0.99, p = 0.0056) and heat treatment of psyllium (p = 0.0002), was inversely proportional to incremental blood glucose area (AUC) at both 25g (r= $-$1.00, p = 0.0001) and 50g (r = $-$0.94, p = 0.0004) CHO levels. AUC of meals of two different nutrient levels only correlated to log hardness after adjusting for the grams of carbohydrate in meals (r = $-$0.94, p $<$ 0.0001). Viscosity of meals, with nutrient levels taken into consideration, is an important parameter in predicting postprandial blood glucose response.
Soil behaviour in the stability evaluation of a half-century-old hydraulic fill dyke

The purpose of this study is to analyze the impact that reservoir filling may have on a dyke known as Cacaria 2 which is owned and operated by Light SESA in Rio de Janeiro, Brazil. Dyke 2 was built in 1945 according to the hydraulic fill method to close off a low topographical area to create the "Lajes Reservoir," part of the Lajes Hydroelectric and Water Supply Project. Plans are being made to raise the reservoir level 3 meters above the existing operational level. The dyke is made up of thin interbedded clayey silt layers which cross the dyke's mass in an upstream-downstream direction. The focus of this study is to analyze the properties and behaviour of the soil in one of these layers. This layer, which has been above the reservoir level for over 50 years, will be subjected to the effects of reservoir filling and drawdown (wetting-drying). The main concern is in regard to internal erosion during reservoir filling, because the layer in study is susceptible to deflocculation when saturated by water with low total content of dissolved salts. The dominant clay mineral is Na-kaolinite, which is a residual clay derived from gneiss; and it ranges from dispersive to non-dispersive. (Abstract shortened by UMI.)
Clearance concepts in the kidney

The kidney is an important eliminating organ, capable of metabolism and excretion. The fractional excretion value (FE, unbound urinary clearance normalized to glomerular filtration rate) is typically used to determine whether a compound is net filtered (FE = 1), reabsorbed (FE $<$ 1) or secreted (FE $>$ 1) by the kidney. It was hypothesized that competing routes of elimination within the kidney will influence the clearance estimate of each other. The hypothesis was first tested with computer simulations based on a physiological model of the kidney and parameters describing the renal handling of enalapril, an angiotensin converting enzyme inhibitor that is both metabolized and excreted unchanged by the kidney. Since the location of enalapril metabolism was unknown, simulations were based on two possible models, one which incorporated intracellular metabolism of enalapril, and another which incorporated intraluminal metabolism of enalapril. Results of the simulation study showed that the excretory clearance estimate was decreased in the presence of luminal or cellular metabolism, while metabolic clearance was affected differentially, depending upon the site of renal metabolism. The renal metabolic clearance was predicted to decrease with excretion for the intracellular model, but would increase for the intraluminal model. Studies were then performed in the nonfiltering isolated perfused rat kidney to determine the site of renal enalapril metabolism with data obtained for enalapril and its metabolite, enalaprilat. The observations closely matched the predictions for intracellular metabolism. A final set of studies with enalapril and an esterase inhibitor, paraoxon, was performed in the renal S9 fraction and in the isolated perfused rat kidney preparation. The results demonstrated that urinary clearance estimates were indeed reduced by the presence of intrarenal metabolism. Since the urinary clearance estimate was affected by intrarenal metabolism, FE was not an accurate indicator for the net flux of drug through the kidney.
Researching with ordinary people, race and representation in participatory research discourse

This thesis interrogates participatory research discourse to reveal essentialized categories and modernist assumptions that have exclusionary and racist effects. Liberal humanist discourse that underpins such claims as listening to people's voices, validating their experience, and invoking their participation are examined from critical race and poststructural perspectives. The centrality of the 'autonomous individual' to the conceptualization of empowerment in participatory research is revealed. Autobiographical material, key participatory research texts, and interviews with four participatory researchers provide sites for exploring the discursive and material practices that keep systems of power and privilege intact. Essentialized and racialized identities like 'the researcher' and 'ordinary people' are shown to mask relations of power in the research context. I argue that discursively reproducing these relational identities secures a move to innocence for the participatory researcher. Strategies for resisting privilege and being vigilant about discursive practices are proposed in guidelines for anti-racist participatory research.