Made available in DSpace on 2014-06-11T19:35:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-07Bitstream added on 2014-06-13T20:26:16Z : No. of bitstreams: 1 piagentini_m_dr_botfmvz.pdf: 267759 bytes, checksum: c4056ececa2c37d7a0e0df2a9a4aefa2 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho teve por objetivo comparar a composição bioquímica e as concentrações de testosterona e progesterona no líquido amniótico de fetos bovino da raça Nelore produzidos por fecundação in vivo, fecundação in vivo com transferência de embrião (TE) e produção in vitro (PIV). Os problemas fetais observados ao momento do parto e pós-parto imediato em animais oriundos de PIV e a escassez de pesquisas que determinem a composição do líquido amniótico associada aos três sistemas de produção embrionária permitiram o desenvolvimento deste trabalho. Utilizaram-se 60 animais divididos em: grupo 01 - vacas Nelore gestando bezerros oriundos de inseminação artificial (IA) (n=20); grupo 02 - receptoras gestando bezerros Nelore provenientes de inovulações de embriões oriundos de doadoras superovuladas pelo método convencional (n=20); grupo 03 - receptoras de embriões gestando bezerros Nelore originados de inovulações de embriões oriundos de doadoras pelo método de aspiração folicular (n=20). No momento do parto, após a visualização das bolsas, colheram-se 15mL de líquido amniótico por punção da bolsa com agulha e seringa adequadas. As amostras foram processadas e analisadas no serviço de laboratório clínico do Departamento de Clínica Veterinária da FMVZ/UNESP de Botucatu-SP e no Laboratório de Endocrinologia do departamento de Reprodução Animal e Radiologia Veterinária. Para análise bioquímica foram utilizados Kits comerciais seguindo a técnica recomendada pelo fabricante. A dosagem hormonal de progesterona (P4) e testosterona (T) foi determinada por meio de radioimunoensaio em fase sólida com a leitura realizada em contador Gama Count Cobra II. Os dados obtidos na avaliação bioquímica e no perfil hormonal foram submetidos à análise de variância (ANOVA) e, uma vez demonstrada diferença estatística por 22 esse teste aplicou-se o Método de Tukey, com 5% de nível de significância. / The present work had for objective to compare the biochemical composition and the concentrations of testosterone and progesterone in the amniotic fluid of fetuses of the Nelore cows produced by in vivo fecundation, in vivo fecundation at embryo transfer (ET) and in vitro production (IVP). The fetal problems observed at the delivery moment and at the immediate post-partum in animals originating from IVP and the shortage of researches that determine the composition of the amniotic fluid associated to the three systems of embryonic production allowed the development of this work, adding results to the studies that are being done by other researchers with the placenta of IVP animals. Sixty animals were used divided into 3 groups: Group 1 - Nelore cows pregnant with calves conceived by artificial insemination (AI) (n=20); Group 2 – receptor cows pregnant with Nelore calves provement from superovulation of embryo donors (n=20); Group 3 – receptor cows pregnant with Nelore calves obtained by in vitro production after follicular aspiration (n=20). At the delivery moment, after the visualization of the sacs, 15mL of amniotic liquid were collected by puncture. The samples were processed and analyzed in the service of clinical laboratory of the Department of Veterinary Clinic of FMVZ/UNESP of Botucatu-SP and in the Laboratory of Endocrinology of the department of Animal Reproduction and Veterinary Radiology. For biochemical analysis commercial kits were used following the technique recommended by the manufacturer. The hormonal determinaton of progesterone (P4) and testosterone (T) was performed through radioimmunossay (RIA) in solid phase with the reading accomplished in accountant Gama Count Collects II. The data obtained in the biochemical evaluation and in the hormonal profile were submitted to the variance analysis (ANOVA) and, once demonstrated a statistic difference by that method the Tukey test was applied, with a 24 5% of level significancy.

No description available.

The concept that the renal excretion of water and electrolytes is partly governed by the volume in some fluid compartment of the body is one which has received some experimental verification. Attempts to define a mechanism sensitive to changes in some fluid compartment of the body have provided support both for and against the theory that stimulation of sensory nerve endings in the intrathoracic circulation sets up afferent impulses in the vagus nerves which diminish the release of antidiuretic hormone from the neurohypophysis and so cause diuresis. Evidence which supports the theory comes from experiments in which atrial distension has been associated with a reduction of antidiuretic activity in the circulating blood. Evidence which does not support the theory comes from experiments in which the diuretic response to left atrial distension has been demonstrated during infusion of vasopressin at rates adequate to completely inhibit water diuresis in conscious dogs (0.025 m-u./kg./min.). A series of experiments has been carried out in an attempt to define the role of antidiuretic hormone in the diuretic response to left atrial distension. In one series, experiments were designed to test the effects of different doses of vasopressin upon the diuretic response to left atrial distension. The results of this series showed that the diuretic response to left atrial distension was composed of an increase in solute excretion and an increase in water excretion. At a rate of infusion of vasopressin of 0.4 m-u./kg./min. or above the increase in water excretion was abolished while the increase in solute excretion was unaffected. In another series, experiments were designed to test the renal response to large changes in vasopressin concentration. The concentrations of vasopressin used (0.4 m-u./kg./min. and 0.04 m-u./kg./min.) completely inhibited water diuresis in conscious dogs. The results of this series indicated that in the hydrated anaesthetized dog, a change from the high concentration of vasopressin to the lower concentration may cause a transient dilute diuresis. These results support the view that a decrease in the circulating concentration of antidiuretic hormone is one mechanism which may produce a diuretic response to left atrial distension. The results will be reported in a condensed form (Mason and Ledsome, 1971; Ledsome and Mason, 1971). / Medicine, Faculty of / Cellular and Physiological Sciences, Department of / Graduate

Reverse osmosis (RO) desalination plants enable the production of high-quality freshwater from seawater, explaining the increasing global use of this technology. However, a major operational challenge for RO is biofouling, caused by excessive biomass accumulation. Membrane fouling simulators (MFSs), downsized membrane systems, were demonstrated to be suitable for biofouling studies using tap water. There is a need to investigate biofouling using natural seawater. The seawater MFS studies involved (i) an exploratory study to evaluate the MFS setup, (ii) long-term operation without feed water nutrient dosage, (iii) impact of nutrient concentration, and (iv) a comparison of biofouling development with freshwater. MFSs were operated parallel at constant feed flow (0.2 m/s), with feed spacer and RO membrane, at varying biodegradable organic nutrient concentrations (0, 50, and 200 µg C/L). The relative pressure drop (RPD) was monitored over time, and biofilm development was characterized through the MFS window applying optical coherence tomography (OCT). Results demonstrated for seawater that (i) the developed setup had a reliable operation and provided reproducible data, (ii) biofouling development presented a minimal effect when nutrient concentration was quadrupled, (iii) there was no correlation between the nutrient concentration and growth rate for seawater experiments, suggesting biofilm development under conditions close to the maximum growth rate. Compared to tap water at the same nutrient concentrations, seawater showed much faster biofilm development, pressure drop increase, and strongly different biofilm morphology. This research provides new insights, new research directions and underlines the importance of doing MFS research with natural seawater.

PhD Thesis / Morphogens (often acting as transcription activators or repressors) govern pattern formation and cell differentiation during early embryogenesis. Abnormal distributions of morphogens can result in developmental defects or even death. Oftentimes, thresholds of concentrations of morphogens behave like an ON/OFF switch for the activation or repression of downstream genes. Accurate measurements of morphogen concentration and mobility in space and time can help tackle the puzzle of how exactly cascades of hundreds of morphogens coordinate their targets precisely and promptly amidst crowded and complicated cellular environments. The research question at the centre of my thesis is that of the concentration and dynamics of two morphogens with opposite functions in the early fly embryo. In the work presented in this thesis, we use Fluorescence Correlation Spectroscopy (FCS) and confocal imaging to achieve extremely low ($\sim$ nM) concentration measurements in live \textit{Drosophila} embryos expressing recombinant fluorescent morphogens, by carefully taking into account background noise and photobleaching effects. The dynamics of both Bicoid (Bcd) and Capicua (Cic), an activator and a repressor morphogens, were further studied using FCS, Fluorescence Recovery After Photobleaching (FRAP) and Monte Carlo simulation. We found that both types of morphogens are very mobile in nuclei, explaining how they are able to turn on or off gene expression in only a few minutes. However, these two morphogens with opposite functions have drastically different nucleo-cytoplasmic transport behaviours, where the activator can pass through the nuclear envelop (NE) relatively freely while the repressor is jailed inside nuclei during interphase. These findings can provide clues to distinguish between several hypothetical models (including the newly proposed hub hypothesis) trying to explain the mechanisms of target gene search and transcription regulation. In this thesis, a background introduction on transcription factors and morphogens is given in Chapter 1, with a focus on the two transcription factors (the activator Bicoid and the repressor Capicua) studied in this thesis. Next, experimental details such as fruit fly maintenance, and fluorescent techniques used to measure concentration and mobility are described in Chapter 2. From Chapter 3 to Chapter 5, three manuscripts from the thesis author, either published or in preparation for submission are presented in sequence. Chapter 3 introduces a new method to accurately measure protein concentration in the presence of noise and photobleahing in early \textit{Drosophila} embryos using FCS. Chapter 4 contains the results of concentration and mobility measurements for Cic which contribute to the finding that Cic acts like a fast brake in transcription repression. Chapter 5 compares the similarities and differences of the dynamics of Bcd and Cic through multiple lenses. Finally, a conclusion and future outlook are given in Chapter 6. / Thesis / Doctor of Philosophy (PhD) / Have you ever wondered how a single fertilized egg turns miraculouly into a beautifully organized living being, be it an insect, a cat, or a human? It turns out that an important group of molecules called morphogens govern the formation of body pattern. These molecules (usually proteins) form concentration gradients along the different body axes of that organism and influence gene expression. Abnormal distribution of morphogen can result in defects in embryo development and even death. Thus knowing how much morphogen is present in the early developing embryo, as well as how it forms gradients and how the morphogen concentration is translated into a pattern can help us better understand early embryo development. My thesis focuses on accurate measurements of morphogen concentrations and dynamics using fluorescence techniques. We were able to obtain concentration maps for two morphogens, the activator Bicoid and the repressor Capicua, in early developing fruit fly embryos. We also found that despite having opposite functions, the activator and the repressor have similar intranuclear dynamics, but drastically different internuclear mobility. Our findings provide clues to distinguish between multiple hypothetical models scientists have put forward to explain the mechanisms of transcription regulation.

No description available.

This quasi-experimental field study examined the efficacy of an intervention to decrease alcohol abuse by college students. The harm reduction approach states that the ultimate goal when dealing with an unsafe behavior should be abstinence, but any change in behavior in the direction of less harm is supported. This approach was used as the basis of the current research, in combination with differential reinforcement in order to reduce alcohol consumption and its behavioral outcome, blood alcohol concentration (BAC). A total of 409 male and female college students participated while in the applied setting of four fraternity parties. The study took place at two separate fraternity houses, a control fraternity and an experimental fraternity. During the intervention phase, participants with a BAC below .05 were entered into a raffle to win a cash prize. Upon entry to the intervention party, participants were given flyers announcing the raffle and contingency, and gender-specific nomograms to aid in BAC self-monitoring. Dependent measures were blood alcohol concentration measured by hand-held breathalyzers, percentage of participants below criterion BAC levels (i.e., .05 and .08), accuracy of BAC self-estimation, number of negative outcomes due to excessive alcohol consumption, number of positive outcomes due to abstinence or moderate alcohol consumption, and amount of reported fun experienced at the party. Results showed the intervention did not significantly reduce the intoxication of participants or increase the percentage of participants below criterion BAC levels. These results are best explained by a floor effect, as the experimental fraternity had a relatively low baseline BAC. The use of nomograms at the intervention party increased the accuracy of students' BAC self-estimations. Implications for nomogram use and improvements for future implementation of the incentive/reward intervention are discussed. / Master of Science

Freeze concentration is a thermal separation process that is used to purify aqueous solutions. One application of recent interest is seawater desalination. For freeze concentration to be an effective desalination method, a high ice growth rate and product purity must be achieved with energy usage comparable to that of competing technologies. The purpose of this thesis is to develop a coupled heat and mass transfer model to predict the growth rate and purity of the solid phase for ice grown about a horizontal, immersed tube. By simultaneously solving the heat and mass transfer problems, this model improves upon previous attempts found in the literature. In addition, an experimental apparatus was constructed and a series of ten experiments was run, considering a range of cooling rates, process times, and saltwater concentrations. Average ice growth velocities ranged from 3.1-13.1 mm/h and the observed partition coefficient ranged from 0.42-0.71. The model was calibrated using experimental data, and the coefficients of variation for the fitted model's prediction of ice mass and capture concentration were 15.4% and 7.6% respectively. Based on insights from modeling and experimentation, a series of suggestions are made regarding future modeling and process design. / Master of Science / Freeze concentration is a thermal process that is used to purify a liquid containing dissolved solids. One application of recent interest is seawater desalination. For freeze concentration to effectively purify seawater, a high ice growth rate and product purity must be achieved with energy usage comparable to that of competing technologies. The purpose of this thesis is to develop a coupled heat and mass transfer model to predict the growth rate and purity of the solid phase for ice grown about a horizontal, immersed tube. By simultaneously solving the heat and mass transfer problems, this model improves upon previous attempts found in the literature. In addition, an experimental apparatus was constructed and a series of ten experiments was run, considering a range of cooling rates, process times, and saltwater concentrations. Average ice growth velocities ranged from 3.1-13.1 mm/h and the salinity of the ice ranged from 0.42-0.71% of the original concentration. Based on insights from modeling and experimentation, a series of suggestions are made regarding future modeling and process design.

Thesis (doctoral) - Universität, Hamburg, 2004. / Bibliographie p. 365-374. Index.

Concentration of microorganisms from a sample volume would increase the limits of detection of samples used for rapid-detection methods. Rapid detection methods are is advantageous for the food industry to rapidly test for bacteria in order release products on a timely basis. Ultrasonic concentration was considered a promising method for manipulation of microorganisms. An ultrasonic chamber consisting of parallel piezoceramic discs with a reticulated polyurethane foam mesh was used to concentrate Saccharomyces cerevisiae yeast and Escherichia coli bacteria. The concentration of yeast was seen to increase by 200% (from 8.0 x 104 cells mL-1 to 2.4 x 105 cells mL-1) while almost zero concentration of bacteria was observed. The poor concentration effect seen with the smaller microorganisms was explained by the volume dependent acoustic radiation force exerted on the particles; the concentration forces are 1,000 times smaller for a 1 μm bacteria cell versus a 10 μm yeast cell.