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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

The origin and physiological significance of high plasma buffering in brown bullhead (Ameiurus nebulosus) /

Szebedinszky, Cheryl January 1900 (has links)
Thesis (M.Sc.) - Carleton University, 2001. / Includes bibliographical references (p. 94-112). Also available in electronic format on the Internet.
42

Resting hemodynamic function and reactivity to acute stress the influence of hydration on cardiac function and plasma volume /

Rochette, Lynne M. January 2004 (has links)
Thesis (M.S.)--Ohio University, November, 2004. / Title from PDF t.p. Includes bibliographical references (p. 83-90)
43

The isolation, identification and exploration of the biophysiological significance of plasma biliverdin in the ballan wrasse (Labrus bergylta)

Clark, William D. January 2016 (has links)
Labrus bergylta (ballan wrasse) have recently emerged as a key resource to aquaculture through proven efficacy in controlling infestations of sea lice (Leclercq et al., 2014a). However, due to complex ecology, and a complete lack of sexual dimorphism gender identification endures as a key restriction to optimising broodstock management therefore male selection and establishing optimal sex ratios is difficult (Talbot et al., 2012). L. bergylta, are noted to demonstrate unusually coloured plasma ranging in hue from green to blue with the haem catabolite biliverdin established as the causal pigment in the majority of cases (Abolins, 1961). As most vertebrates excrete biliverdin, or rapidly metabolise it to prevent toxicity, accumulation to such excess is a phenomenon which merits attention. Notably, correlation between plasma biliverdin and gender has been reported in some Labridae. Although patterns vary between species, the abundance or characteristics were such that sexual identity could be established (Gagnon, 2006). Pigment analysis was therefore proposed as a potential sex-marker in L. bergylta. In the initial experimental phase (Chapter 3), the ultimate aim was to isolate and identify the blue pigment from L. bergylta plasma, and to develop a method of quantification. The initial phase confirmed the target pigment was biliverdin IXα by visible spectroscopy, TLC, HPLC, MSMS, and a series of reactions. Following this, a protocol was developed (Chapter 2) to quantify the pigment. This method was applied accross plasma sampled from four geographically distinct wild populations with established biometrics including age, mass, length, gender and external phenotype. Subsequent analysis revealed that although pigment abundance did not vary relative to ontogeny, and there was no difference in concentration between the binary genders, plasma biliverdin was depleted in individuals undergoing sex change. Although this conclusion was complicated by significant biliverdin variation relative to origin and phenotype, which were interrelated based on relative distributions across populations, further analysis of plasma pigment in related species identified that biliverdin accumulation was associated with protogynous species. Considering the anti-oxidant capacity of biliverdin and other potentially relevant functions, this was indicative of association with the tissue remodelling processes which accompany inversion. During Chapter 3 it was noted that the biliverdin appeared tightly bound to a protein moiety. Based on the hypothesis that the pigment was actively managed and accumulated in L. bergylta plasma by this association, the next phase of experiments (Chapter 4) was an exploration of biliverdin and its binding protein in L. bergylta. The experiments revealed plasma biliverdin comigrated with the protein such that it was depleted from solution at the same rate indicating that all of the pigment was associated. Subsequent electrophoretic experiments using the fractionation products supported this, and UV fluourescence identified fragments of interest in the 25-28 kDa region. To confirm observations from the previous cross species comparison, the study was similarly expanded to include other Labrini. This revealed that although the 25 kDa band was common to all species, and genders, the 28 kDa band was collocated with the protogynous, and as such hyperbiliverdinaemic species. The 28 kDa band was sequenced using MSMS, and was identified as similar to the lipocalin Apolipoprotein A1. In combination with the properties of biliverdin, and considering that ApoA1 is analogous to serum albumin in many telesots, this supported the chromoprotein association as the main mechanism of biliverdin accumulation in such species. Further to the proposed function of biliverdin with inversion processes, and considering relevant literature, the active properties of ApoA1 suggested additional associations with prolonged altered states of metabolism which considering the ecology of L. bergylta would include gender transition, overwintering torpor and prolonged micronutrient limitation, all of which occur simultaneously. Other potential roles include modulating inflammatory responses, inhibiting pathogenic incursions and acting as an external point of contact innate immune response. From this, it was concluded that the data fully supported the previous assertions of biliverdins relevance in protogynous species, and identified a number of properties which could be of great interest to the industry in terms of welfare. The final experimental phase (Chapter 5) had two main aims. The first was to establish whether protogynous inversion could be artificially induced in L. bergylta as a means of generating male fish, and whether size had any effect on the process. The second was then to utilise controlled induction for tracking biliverdin mobilisation across the process to test the previous hypothesis. The preliminary trial demonstrated that both androgen inhibition and non-aromatisable testosterone could stimulate inversion in female L. bergylta. From this, the second trial then determined that although there was a dose dependant effect in that high androgen dosages appeared to compress the inversion process, relative size was not a factor. Gonad histology was used to create a unified scale of protogynous transition which could be expressed as a gradient to structure the biliverdin analysis. Although the biliverdin data demonstrated cryptic trends at the higher resolution gender scales, when the endpoint was condensed back to the binary gender scale employed previously (Chapter 3), the prior assertion of depletion during transition, and therefore the association with sex change associated tissue remodelling was supported. Ultimately this thesis revealed links between the biliverdin macromolecule and the highly unusual metabolic and physiological demands of gender transition in sequentially protogynous hermaphroditic temperate wrasse species.
44

Lactate turnover in fast-moving vertebrates : the control of plasma metabolite fluxes

Weber, Jean-Michel January 1987 (has links)
During sustained exercise, working muscles must be supplied with adequate kinds and amounts of exogenous fuels, and the delivery rates of oxygen and oxidizable substrates should be matched. The study of metabolite fluxes and their regulation is therefore critical to the understanding of exercise metabolism. Lactate has received renewed attention from physiologists and biochemists with the realization that it is not only an end product of glycolysis, but also an important fuel for aerobic work. As an oxidizable fuel, this substrate may provide some performance advantage over other fuels such as glucose and free fatty acids. The goals of this thesis were: 1) to determine whether endurance-adapted animals can support higher plasma lactate turnover rates than sedentary animals; and 2) to investigate the major factors involved in the regulation of plasma metabolite turnover at the whole-organism level - using lactate as a model. Lactate turnover rates were measured by bolus injection of [U-¹⁴C]lactate in skipjack tuna, Katsuwonus pelamis, and in thoroughbred racehorses, Equus caballus. In tuna, turnover rates ranged from 112 to 431 umol min⁻¹ kg⁻¹ and they were positively correlated with lactate concentration (slope = 15.1, r = 0.92). This teleost is able to support higher plasma lactate turnover rates than expected for a mammalian lower temperature, and lactate is probably an important oxidizable fuel in this species. For comparative purposes, resting turnover rates of lactate and glucose were plotted versus body mass on a log-log scale for a wide range of mammalian species. These plots were linear, and they showed the same slope as the classic body mass vs metabolic rate relationship. Thoroughbred horses are likely to have an aerobic scope of 40-fold or more. One of their main physiological adaptations to exercise is the ability to increase hematocrit by more than one and a half-fold in response to exercise. In the present study, this adjustment allowed them to reach an A-V difference in 0₂ content of more than 23 vol% during maximal exercise, a much higher value than other mammals. Their lactate turnover rate and cardiac output were measured at rest and two levels of submaximal exercise (45 and 55 V0₂ max) to investigate the relationship between cardiovascular adjustments on plasma lactate turnover rate. Cardiac output ranged from 106 to 571 ml min⁻¹ kg⁻¹, and mean lactate turnover rate from 9.3 at rest, to 75.9 umol min⁻¹ kg⁻¹ at 55% V0₂ max. In contrast with the situation found in tuna, the lactate turnover rates of thoroughbreds were not elevated compared with other mammals, showing that the metabolic adaptations of these outstanding athletes do not include the ability to sustain higher lactate fluxes than sedentary animals. In horses, the contribution of plasma lactate oxidation to V0₂ is minimal, and this substrate is not an important oxidative fuel; lipid oxidation may represent their major pathway for aerobic energy production during exercise. The ability to oxidize plasma lactate at high rates is therefore not necessarily required for the "elite" performance of endurance exercise. This study also shows that both, plasma lactate concentration and cardiac output are positively correlated with turnover rate. The correlation between cardiac output and lactate turnover rate is independent of the relationship between plasma lactate concentration and turnover rate. Plasma metabolite concentration and cardiac output can be regulators of plasma metabolite turnover rate. It is proposed that these two variables are, respectively, the fine and coarse controls for flux rate adjustments during exercise. / Science, Faculty of / Zoology, Department of / Graduate
45

The Sensitivity of Human Blood Plasma to the Coagulase Enzyme Secreted by Members of the Genus Micrococcus

Coultas, John T. January 1950 (has links)
The problem in this investigation consisted of, first, the isolation from human sources and identification of thirteen cultures of typical micrococci to be used as test organisms; second, the acquisition of blood plasma from thirty different human beings; and third, the determination of the possibility of individual variation in sensitivity of blood plasma to the micrococci used as test organisms as revealed by the coagulase test.
46

Association of Childhood Physical and Sexual Abuse with Intimate Partner Violence, Poor General Health and Depressive Symptoms among Pregnant Women

Yasmin V. Barrios, Bizu Gelaye, Zhong, Qiu-Yue, Christina Nicolaidis, Marta B. Rondon, Pedro J. Garcia, Pedro A. Mascaro Sanchez 02 February 2015 (has links)
This research was supported by an award from the National Institutes of Health (NIH), the Eunice Kennedy Shriver Institute of Child Health and Human Development (R01-HD- 059835). The NIH had no further role in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication. The authors wish to thank the dedicated staff members of Asociacion Civil Proyectos en Salud (PROESA), Peru and Instituto Materno Perinatal, Peru for their expert technical assistance with this research. / Objective We examined associations of childhood physical and sexual abuse with risk of intimate partner violence (IPV). We also evaluated the extent to which childhood abuse was associated with self-reported general health status and symptoms of antepartum depression in a cohort of pregnant Peruvian women. Methods In-person interviews were conducted to collect information regarding history of childhood abuse and IPV from 1,521 women during early pregnancy. Antepartum depressive symptomatology was evaluated using the Patient Health Questionnaire-9. Multivariable logistic regression procedures were used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (95%CI). Results Any childhood abuse was associated with 2.2-fold increased odds of lifetime IPV (95%CI: 1.72–2.83). Compared with women who reported no childhood abuse, those who reported both, childhood physical and sexual abuse had a 7.14-fold lifetime risk of physical and sexual IPV (95%CI: 4.15–12.26). The odds of experiencing physical and sexual abuse by an intimate partner in the past year was 3.33-fold higher among women with a history of childhood physical and sexual abuse as compared to women who were not abused as children (95%CI 1.60–6.89). Childhood abuse was associated with higher odds of self-reported poor health status during early pregnancy (aOR = 1.32, 95%CI: 1.04–1.68) and with symptoms of antepartum depression (aOR = 2.07, 95%CI: 1.58–2.71). Conclusion These data indicate that childhood sexual and physical abuse is associated with IPV, poor general health and depressive symptoms in early pregnancy. The high prevalence of childhood trauma and its enduring effects of on women’s health warrant concerted global health efforts in preventing violence. / : This research was supported by an award from the National Institutes of Health (NIH), the Eunice Kennedy Shriver Institute of Child Health and Human Development (R01-HD-059835). The NIH had no further role in study design; in the collection, / Revisión por pares
47

Identification of Possible Potential Protein Biomarkers for Stroke Using Different Chromatographic and Mass Spectrometric Methods

Kodali, Phanichand, Ph.D. 24 September 2013 (has links)
No description available.
48

The Relationship and Seasonal Changes of Hydration Measures in Collegiate Wrestlers

Borden, Emily C. 23 August 2018 (has links)
No description available.
49

I. Methods for digoxin and metabolite determination in urine, feces and plasma application to detection of Ṟ-dihydrodigoxin in humans and ; II. A theoretical examination of the kinetics of enterohepatic cycling /

Shepard, Theresa A. January 1983 (has links)
No description available.
50

Methionine, lysine, and phenylalanine infusion and the effect on plasma amino acid concentrations and mammary uptake

Norman, Alfred W. 02 June 2010 (has links)
Ten cows were used in 4 x 4 Latin squares with an extra period for estimation of carry-over effects to study plasma amino acid responses to jugular infusion of amino acids at early, mid, and late lactation. Methionine (M), methionine + lysine (ML), and methionine + lysine + phenylalanine (MLP) in a balance with glutamic acid (C) were infused at 25% of the amino acid content of pretreatment milk via the jugular vein. Rations were formulated at 16, 15, and 14% crude protein and 15, 18, and 21% crude fiber for 30, 120, and 240 day lactational groups. Carry-over effects were present only in arterial blood at 240 days. Differences in milk production were not significant, although production increased on M, ML, and MLP at 30 days. Plasma amino acid responses of nonruminants were utilized to aid in evaluation. Arterial and venous plasma amino acid concentrations were lowest on ML at 30 days, while amino acid uptake was significantly increased by M. At 120 days plasma responses were inconclusive and non-significant. The amino acid uptake trend followed that observed at 30 days. At 240 days plasma amino acid concentrations were lowest with ML, while uptake was increased on MLP. Essential amino acids were ranked in potential orders of limitation by amino acid extraction and utilization for milk protein by the mammary gland. Order of limitation differed between calculation methods but was similar for all three stage.s of lactation. Orders of limitation were as follows: Amino acid extraction - methionine~ lysine, arginine, leucine, phenylalanine, isoleucine, threonine, valine, and histidine. Amino acid utilization - phenylalanine, threonine or histidine, valine, leucine, methionine, lysine, isoleucine, and arginine. Since there was no substantial change in order of limitation with infusion, either protein intakes were above requirements or amino acids not infused are candidates for limitation. However, among amino acids infused, the parameters observed suggested lysine or methionine at 30 days, methionine at 120 days, and no apparent choice at 240 days. / Master of Science

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