Dissertationen: „Maternal physiology“

1

McAllister, Kelli. „Effect of maternal care on maternal responsiveness and astrocyte plasticity in the medial amygdala and medial preoptic nucleus in the rat“. Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112541.

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Estrogen acts on maternal circuitry to establish maternal behaviour in otherwise non-maternal rats. The precise mechanisms by which estrogen primes maternal circuitry are unknown; however, the medial preoptic area (MPOA) stimulates maternal behaviour whilst the medial amygdala (MeA) inhibits it. This thesis aimed to address the link between estrogen sensitivity, astroglia and maternal behaviour. Maternal care influences maternal behaviour of female offspring. One mechanism underlying this influence is differential estrogen sensitivity within the MPOA. Estrogen receptor alpha (ERalpha) expression was examined in offspring of High and Low licking/grooming (LG) dams within the MPOA. Enhanced expression ERalpha was limited to the medial preoptic nucleus in offspring of High LG dams and the anteroventral periventricular nucleus in Low LG dams. Adult nulliparous offspring of High and Low LG dams were assessed for maternal responsiveness using the pup sensitization paradigm. Offspring of Highs showed maternal behaviour significantly earlier than offspring of Lows. Brains of pup-exposed and pup-naive High and Low offspring were analyzed for astroglial markers glial fibrillary acidic protein (GFAP) and glutamine synthetase. Pup-naive animals showed more GFAP positive cells within the posteroventral MeA, with no differences within the MPOA and no effect of maternal care. Glutamine synthetase, a glial-derived enzyme necessary for glutamate production, showed greater expression within the MeA of High LG pup-naive animals; with no maternal care differences observed in pup-experienced animals. Thus, long-lasting changes within maternal circuitry established in early life are reflected in regionally specific enhanced estrogen sensitivity and latency to display maternal behaviour, but the effects are less clear with respect to astroglia.

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2

Doherty, N. Nicola. „Neurobehavioural effects of maternal diabetes on the fetus“. Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388050.

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3

Robertson, Anthony J. „Hormonally mediated maternal effects in birds“. Thesis, University of Glasgow, 2009. http://theses.gla.ac.uk/803/.

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The main aim of this thesis was to investigate the effects of environmental conditions, particularly unpredictable or potentially negative ones, on the maternal transmission of the primary avian stress hormone, corticosterone, to developing embryos. We currently lack information on the extent to which conditions in the maternal environment are transmitted to the offspring in birds via egg compositional changes. It is possible that maternally derived hormonal signals communicate information about the external environment to developing embryos and directly influence the fitness of their offspring in a negative or positive way. I found, using captive zebra finches, that the experimental stressor of unpredictable food availability (as these birds are used to ad libitum food) experienced by mothers can elevate yolk CORT concentrations, but only when combined with the additional demand of laying a replacement clutch (potentially a buffering system to prevent mild stressors impacting on CORT transmission to the embryo). I then looked at yolk CORT concentrations in two populations of gulls (herring and lesser black-backed gulls) in which the population trajectories differed depending on environmental conditions (potentially a reflection of different exposures to stressful stimuli). The results however did not support this hypothesis, as there were no differences according to habitat type or between species (where they coexist). This would suggest that the different environmental circumstances (harsher for the herring gull) experienced by these two species are not reflected in differences in their eggs (at least in terms of CORT). This could be the result of the eggs being buffered from the maternal CORT environment or it may be that the difficult environmental conditions are not occurring during the breeding season. We also identified that experimental human disturbance during the laying period does not appear to elevate yolk CORT concentrations, although there was a trend for concentrations to be higher following the loss of the first clutch in the herring gull (as seen in the zebra finches). I also measured yolk CORT concentrations in Common Eider eggs and looked for differences according to the degree of nest shelter. I found no relationship between shelter and yolk CORT, but birds that laid in more sheltered sites had, on average, smaller eggs. This may indicate lesser quality birds are nesting in the sheltered sites and that yolk CORT is not affected by maternal condition. Finally, I looked at another mechanism through which information relating to the maternal environment could be transferred to the embryo. I investigated whether there were any links between maternally derived immunity and CORT by comparing the anti-microbial lysozyme and CORT concentrations in the albumen. I found no correlation between CORT and lysozyme, suggesting that CORT may not affect lysozyme production. It may be that other factors such as colony density and ‘cleanliness’ are more important in determining the concentrations of lysozyme deposited in the egg or that lysozyme production is not sufficiently costly to be influenced by the maternal stress state. The overall theme of my findings is that CORT concentrations in eggs do not appear to vary much with maternal environments. I will discuss these findings in their broader ecological and evolutionary context and discuss if stress hormones are indeed being used as adaptive signals for preparing the embryo for its postnatal environment.

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4

Woo, Chit-shing Jackson, und 胡哲誠. „Ochratoxin A: endocrine disruption potential,transplacental kinetics and maternal exposure assessment“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B4979954X.

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Mycotoxin contamination in food commodities is an age-old problem. Due to the detrimental impact of mycotoxins on human health, exposure to mycotoxins and their health implications have been increasingly recognized. Ochratoxin A (OTA), one of the mycotoxins, has been found to cause diverse toxicities in animals, with potential impact on human health. OTA has been reported to be teratogenic and interfere with steroidogenesis in vivo. Chronic exposure of pregnant women to OTA may be hazardous for the human foetus, especially when endocrine and developmental toxicities are taken into consideration. Accordingly, in the first part of this project, I hypothesized that OTA may interfere with enzymes involved in human placental steroidogenesis. By evaluation of human placental 3β–hydroxysteroid dehydrogenase/isomerase (3β-HSD) at both mRNA and protein (hormonal) levels, my results showed that OTA could up-regulate 3β-HSD1 expression in human placental cells with concentration relevant to human exposure. This study is the first to report the endocrine disruption potential of OTA in human placental cells. As several mycotoxins have been demonstrated previously to cross human placental barrier and OTA has been associated with developmental toxicity in vivo, I further hypothesized that OTA may be transferred through human placenta and accumulate in foetal compartment. In the second part of this project, human perfused placenta was used to investigate the placental toxicokinetics of OTA using concentrations found in serum of pregnant women. Findings from this study clearly showed that the transfer of OTA through term human placenta was minimal, contradicting the existing epidemiological studies reporting higher foetal OTA levels than maternal. This is the first study where transplacental kinetics of OTA has been studied in human perfused placenta. To assess the relevance of the study findings, it is very important to provide information on maternal OTA exposure during pregnancy. Currently there is limited information regarding OTA exposure of pregnant women. The third part of this project aimed at evaluating the frequency and level of exposure to OTA in pregnant women from Egypt, where exposure to dietary mycotoxins is common due to the environmental conditions. Biomonitoring of both serum and urinary OTA levels showed that more than 70% of pregnant women were exposed to OTA with a geometric mean of 0.27 ng/ml in serum and 37.21 pg/mg creatinine in urine indicating frequent exposure of this subpopulation. As an ultimate aim, maternal-foetal risk assessment served as a conclusive part of this project to predict and evaluate both maternal and foetal risk of exposure to OTA during pregnancy. Data from the exposure of pregnant women in Egypt to OTA were further ultilized to conduct maternal-foetal risk assessment in relation to OTA exposure. Based on the refined Klaassen equation for exposure estimation during pregnancy and the benchmark dose approach for risk assessment, this subpopulation of pregnant women generally was not exposed to OTA in a high-risk manner. However, considering the suspected chronic exposure beginning from early pregnancy with high foetal susceptibility and diverse toxic effects, and in particular the potential endocrine disruption of OTA, keeping OTA exposure to a minimum is recommended.
published_or_final_version
Biological Sciences
Doctoral
Doctor of Philosophy

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5

Bagot, Catherine Nancy. „An investigation of the role of maternal hoxiao in embryonic implantation“. Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250192.

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6

Burton, Nicholas O. (Nicholas Oscar). „Maternal environment and offspring physiology : the inheritance of information across a generation“. Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111294.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biology, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references.
From the 4th century BC until the late 19th century AD philosophers and biologists ranging from Hippocrates to Charles Darwin hypothesized that information about the environment could be passed from parents to progeny. However, in 1893, German biologist August Weismann tested these hypotheses and based on his observations concluded that information about the environment could not be transmitted from parents to progeny. Weismann's hypothesis became known as the Weismann barrier and served as one of the founding pillars of modern evolutionary synthesis, which postulates that genetic and phenotypic variability in plant and animal populations are brought about by genetic recombination resulting from sexual reproduction and random mutations. Nonetheless, throughout the 20th century there have been several observations of plants and animals where parental exposure to environmental stress modified offspring physiology. These changes in progeny physiology sometimes enhanced progeny survival in response to repeated environmental stress, suggesting that information about the environment might be passed from parent to progeny. The mechanisms by which parental environment can alter progeny physiology to enhance survival remain unknown. To explore such mechanisms I investigated how parental exposure of the nematode C. elegans to osmotic stress affects its progeny's response to continued osmotic stress. First, I found that C. elegans arrests its development during periods of osmotic stress to enhance survival and that this developmental arrest is caused by a loss of insulin-like signaling to the intestine. I then discovered that exposure of parents to mild osmotic stress enhances progeny resistance to osmotic stress and determined that this adaptation is the result of a loss of insulin-like signaling to the maternal germline, which results in increased expression of the glycerol biosynthetic enzyme GPDH-2 in embryos; the increased GPDH-2 expression results in increased glycerol production, which in turn protects progeny from osmotic stress. These results indicate that insulin can cross the Weismann barrier and suggest that changes in maternal insulin signaling might be responsible for effects of the maternal environment on human diseases that involve insulin signalling, such as obesity and type-2 diabetes. From a screen for mutants that fail to arrest development in response to osmotic stress I identified the cytosolic sulfotransferase SSU-1 and found that SSU-1 functions in the ASJ sensory neurons to control development and insulin-sensitivity in response to osmotic stress.
by Nicholas O. Burton.
Ph. D.

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Dakin, Rachel Sarah. „Effects of postnatal and maternal diet-induced obesity on physiology and vascular function“. Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/8256.

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In recent years there has been an explosion in the rates of obesity, defined as a body mass index greater than 30kg/ m2, and associated cardiovascular disease. Alterations in peripheral glucocorticoid metabolism have been suggested to play a role in the development of obesity. Obesity occurs in both sexes, but the risk of associated metabolic disturbance and vascular dysfunction is greater in men. Although there is no accepted definition of obesity in rodents, the term is used to describe animals with a significant increase in fat pad mass often achieved by feeding a high fat diet. Although animal models of obesity have been useful in delineating potential mechanisms linking obesity with its metabolic and vascular sequelae, most studies have been in male animals and, thus, have not addressed sex differences. Additionally, emerging evidence shows that obesity during pregnancy is associated with increased cardio-metabolic and vascular disease in offspring, although the processes underlying such ‘programming’ effects are unclear. This thesis addresses the hypothesis that exposure to postnatal, or maternal obesity will alter both metabolism and vascular function in mice. Male and female mice maintained on a high fat and sugar diet from 5 weeks of age had increased adipose tissue deposition in adulthood. However there were striking sex differences in glucose homeostasis, mRNA levels and glucocorticoid metabolism, with males being more severely affected. Treatment of male mice with 17β-estradiol ameliorated a number of the effects of the high fat diet, including weight gain and altered glucose homeostasis; additionally estradiol altered glucocorticoid metabolism in the adipose so that it resembled that of females. Suprisingly, given the changes in metabolism, obesity in adult mice produced only small changes in vascular function and did not alter vascular remodelling following injury. The effects of maternal obesity were studied using male offspring aged 3 and 6 months. The offspring of obese mothers had similar body weight, adiposity, plasma lipid and plasma hormone concentrations to controls. In contrast, exposure to obesity in utero was associated with receptor specific changes in agonist-mediated contraction and decreased endothelium-dependent relaxation in male offspring. Despite these changes in vascular function, no alterations in blood pressure or vascular remodelling following injury were present. These results demonstrate that the more profound changes in glucose-insulin homeostasis associated with obesity in male humans can be recapitulated in rodent models and imply that estradiol plays a role in protecting the metabolism of female mice, potentially by alteration of glucocorticoid metabolism. Despite altered metabolism in postnatal obesity vascular function remained normal suggesting metabolic and vascular dysfunction are not intrinsically linked. Conversely, maternal obesity did not cause any overt changes in offspring metabolism but caused vascular dysfunction implying these parameters can be programmed independently.

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Calley, John Nels 1961. „The Drosophila maternal-effect mutantcappuccino and its interactors“. Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/288825.

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cappuccino (capu) is a Drosophila melanogaster gene required for establishing the dorsal-ventral and anterior-posterior axes of the developing egg and embryo. Egg chambers mutant for capu exhibit cytoplasmic streaming during mid-oogenesis that does not normally occur until late oogenesis. All known capu alleles stream at the same speed. Since capu alleles do differ in their effects on the dorsal-ventral axis, it is unlikely that premature streaming is a cause of the dorsal-ventral defects. Premature streaming may, however, cause the posterior defects. Streaming occurs at the same speed if isolated egg chambers are treated with the actin depolymerizing drug cytochalasin D, which suggests that CAPU may act in the actin cytoskeleton. A screen for proteins which physically interact with CAPU identified profilin, a regulator of the actin cytoskeleton as a probable partner of CAPU. This again suggests that CAPU acts in the actin cytoskeleton. CAPU is a member of the formin homology (FH) family of proteins. Sequence analysis of this family makes it possible to multiply align all family members throughout their carboxy-terminal halves. This makes possible better predictions of secondary structure, phylogenetic analysis, and identification of novel regions of conserved sequence. Analysis of the amino-terminal halves suggests that significant alignment is also possible in these more highly divergent regions. Members of the rho family of small GTPases have been implicated in the regulation of the actin cytoskeleton. They physically associate with members of the FH family, including CAPU. All four rho-like proteins tested associate with CAPU in the Interaction Trap system. There are also indications of genetic interactions between capu and the rho-like genes dcdc42 and drac1.

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9

Astbury, Stuart M. „The influence of maternal diet on intestinal adaptation in the mother and offspring“. Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/31390/.

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The effect of maternal nutrition on fetal and offspring growth and risk of disease in later life is well established. Animal models have shown that the small intestine can be preferentially affected by growth restriction compared with other organs, yet the effect of maternal diet on gastrointestinal (GI) development has not been well studied. Furthermore, both the maternal GI tract and microbiome undergo significant adaptations during pregnancy in response to the increased nutritional demands of the growing fetus, which may be further modulated by the maternal diet. Inadequate development of the GI tract may result in an increase in intestinal permeability, as demonstrated in inflammatory bowel diseases. Compromised gut barrier function has been linked to the development of obesity through the passage of endotoxin on Gram-negative bacteria leading to low-level inflammation of the liver and adipose tissue. The aim of this thesis was to use two animal models of maternal dietary manipulation that are representative of suboptimal nutrition characterised by the nutritional excess of macronutrients found in many Western diets. The effect of either fat in the form of palm oil and carbohydrate in the form of fructose were therefore examined with particular focus on the gut. This was undertaken in a pig model to examine the effects around the time of birth and in the juvenile offspring, whilst in a rat model both the mothers and offspring were studied. Addition of 10% fructose to drinking water in two generations of pregnant Wistar rats induced impaired glucose tolerance and raised serum triglycerides, but only in the second generation. Sequencing of the maternal microbiome in first generation dams through pregnancy revealed significant changes in microbial diversity from pre-mating to late pregnancy, both between and within dams. Consumption of the fructose diet led to further changes in microbial diversity. Offspring of fructose-fed mothers were growth restricted and had significantly shorter small intestines compared to controls. Changes in gene expression in the ileum and jejunum were indicative of raised intestinal permeability in second-generation dams, and included the epithelial tight junction genes occludin (OCLN), claudin (CLDN) and junctional adhesion molecule (JAM). In both generations the fructose diet significantly upregulated glucose transporters 2 and 5, and sodium-glucose linked transporter 1 in the ileum and jejunum suggesting that a relatively low level supplementation of fructose gradually increases the absorptive capacity of the small intestine for both glucose and fructose. This may explain the significantly impaired glucose tolerance and insulin resistance observed in second-generation offspring. To study maternal fat supplementation, sows were fed a standard commercial diet supplemented with palm oil (6.6% added to commercial feed) throughout gestation. Median birth weight offspring born to fat supplemented mothers sampled at 7 days demonstrated no growth restriction, but significant downregulation in OCLN, CLDN and JAMA expression, suggesting increased intestinal permeability. No changes in offspring body composition were observed at either time point, and effects on gene expression did not persist up to 6 months of age. In conclusion, a suboptimal diet through pregnancy in which macronutrient composition is raised has the potential to compromise gut function in the mother and offspring. The magnitude of effect can however be temporary and dependent on the animal model used as well as the macronutrient targeted.

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10

Girsén, A. (Anna). „Preeclampsia and maternal type-1 diabetes: new insights into maternal and fetal pathophysiology“. Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514291104.

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Abstract Abnormal placentation is associated with preeclampsia and placental insufficiency, both of which increase the risk for fetal growth restriction. So far the early recognition of the risk population for preeclampsia has been problematic. The first hypothesis of this study was that in preeclampsia, the maternal serum proteomic profile is different from that in uncomplicated pregnancies, and this difference is detectable already in early pregnancy. The findings of this study demonstrate that in clinical preeclampsia the maternal serum proteomic profile is different from that in uncomplicated pregnancies with increased levels of placental proteins and antiangiogenic factors in pregnancies with clinical preeclampsia. Furthermore, the early pregnancy maternal serum proteomic profile in women who later develop preeclampsia revealed a distinct and different pattern compared with the profile in clinical preeclampsia. In early pregnancy, the differentially expressed proteins belong to placental proteins, vascular and/or transport proteins and matrix and/or acute phase proteins, while angiogenic and antiangiogenic proteins were not significantly expressed in early pregnancy. Preeclampsia, placental insufficiency, fetal growth restriction and type-1 diabetes may have an impact on fetal cardiovascular hemodynamics. The second hypothesis in this thesis was that in placental insufficiency, abnormalities in fetal cardiovascular status correlate with biochemical markers of cardiac dysfunction and chronic hypoxia. In placental insufficiency, increases in fetal N-terminal pro-atrial (NT-proANP) and pro-B-type natriuretic peptide (NT-proBNP) and in fetal erythropoietin concentrations were related to increased pulsatility in the fetal umbilical artery and descending aorta. In addition, these fetuses demonstrated increased pulsatility in their systemic venous blood velocity waveforms. Thus, in placental insufficiency, biochemical markers of cardiac dysfunction and chronic hypoxia are associated with signs of increased fetal cardiac afterload and systemic venous pressure. Increased NT-proANP and NT-proBNP levels were also detected in fetuses of type-1 diabetic mothers with normal umbilical artery velocimetry. In these pregnancies, NT-proANP and NT-proBNP levels were related to poor maternal glycemic control during early pregnancy.

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Larsen, Caroline, und n/a. „Pheromones, prolactin and maternal behavior : (male pheromones initiate prolactin-induced neurogenesis, decrease anxiety and advance maternal behavior in virgin female mice)“. University of Otago. Department of Anatomy & Structural Biology, 2007. http://adt.otago.ac.nz./public/adt-NZDU20071019.134553.

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Maternal behavior in rodents is dependent, at least in part, on prolactin acting in the brain. Pheromones carried by male mouse major urinary proteins lower serum prolactin levels in female mice. Therefore, we hypothesized that virgin female C57BL/6J mice housed in split cages, where they had pheromonal but not physical contact with a male, would show suppressed maternal behavior. Contrary to our hypothesis, we found split-cage housed females were significantly faster to retrieve 3 foster pups on the first and second day of maternal behavior testing compared to mice housed in individual cages. The advancement in maternal behavior was replicated when virgin females were simply exposed to male mouse urine-soaked bedding. Ovariectomising the mice, to remove the influence of steroid hormones, prior to placement in the split cages, prevented the pheromonal advancement of maternal behavior. The data infer that an ovarian steroid-dependent action of male mouse pheromones primes virgin female mice to express maternal behavior more rapidly when mouse pups are introduced. This effect required greater than 14 days exposure to male pheromones. Male mouse pheromones are reported to suppress prolactin secretion. However, serum prolactin levels in split-caged housed females, where they had pheromonal but not physical contact with a male, were only briefly lowered and became significantly elevated from 24 hours until 72 hours of pheromonal contact. Despite the early increases in prolactin after pheromone exposure, levels were significantly lower in the pheromone-exposed females when maternal behavior was tested after 21 days. It has been previously reported that prolactin is important in the onset of maternal behavior, but is not required for the ongoing maintenance of maternal behavior. We hypothesised that the hyperprolactinemia observed in the first 24-72 hours of pheromonai exposure had subsequently led to the enhanced maternal behavior. To test this we injected a group of individually-housed mice with slow release prolactin for 48 hours to simulate the period of hyperprolactinemia, and blocked prolactin secretion in a group of split-caged housed females with bromocriptine, and tested their maternal behavior 18 days later. The mice injected with prolactin had enhanced maternal behavior, compared to controls injected with a placebo. By contrast, bromocriptine inhibition of prolactin secretion completely prevented the pheromonal enhancement of maternal behavior. This suggests that the pheromonal advancement of maternal behavior is specifically mediated by a 48-hour period of sustained hyperprolactinemia. It has been previously shown that pregnancy increases neurogenesis in the subventricular zone in a prolactin-dependent manner. Therefore, as the male pheromone-induced advancement of maternal behavior is prolactin-dependent and takes some time to occur, we hypothesized that long-term pheromonal contact initiates mitogenesis in the subventricular zone. Split-caged housed mice showed a significant increase in BrdU-labeled cells in the subventricular zone after 7 days of contact which reduced to baseline levels by 14 days of contact. The mice injected with BrdU on day 7 of contact and killed 21 days later showed a significant increase in labeled cells in the accessory olfactory bulb compared to controls. The data suggest that male mouse pheromones initiate mitogenesis in the subventricular zone of virgin C57B6 mice, in an exposure-dependent manner, and that these cells travel via the rostral migratory stream to the accessory olfactory bulb. As with the effect on maternal behavior, the pheromone-induced increase in neurogenesis was steroid- and prolactin-dependent. During pregnancy and lactation in rodents, prolactin receptor expression is increased in the MPOA, an adaptive change, which could lead to an increased neuronal response to serum prolactin levels, which are high just prior to parturition, and consequently could underlie the enhanced maternal responses seen in late pregnancy and after parturition. It is known that systemic prolactin can access the brain, but it is also possible that there could be local synthesis of brain prolactin acting in an autocrine or paracrine manner. Therefore we hypothesized that the pheromonal-induced changes in maternal behavior are being mediated by altered prolactin receptor expression/sensitivity and/or increased production of brain prolactin. Using RT-PCR to measure levels of prolactin receptor and prolactin mRNA, we found changed expression of the 3 short forms and the long form of prolactin receptor mRNA in the arcuate nucleus, paraventricular nucleus, bed nucleus of the stria terminalis, and MPOA with either exposure to male pheromones or pups. We also found changes in prolactin mRNA in the MPOA and paraventricular nucleus after exposure to pups or male pheromones. The data suggest that altered levels of expression of the receptor, coupled with local production of brain prolactin acting in an autocrine or paracrine manner, may cause a net change in prolactin cell signaling, which leads to adaptive responses which ensure reproductive success. There is extensive evidence that dopamine is a key neurotransmitter mediating maternal behavior. In addition, there is some evidence that serotonin may also be involved in regulating maternal behavior. Therefore, we hypothesised that the pheromonal-induced changes in maternal behavior would be associated with increased dopaminergic and/or serotonergic neuronal activity in the MPOA and other areas of the brain implicated in maternal behavior expression. Using HPLC to measure levels of dopamine and serotonin and their respective metabolites, we found a significant increase in serotonergic and dopaminergic neuronal activity in the MPOA of virgin female C57BL/6J mice after 24 hours of pheromonal contact. The neuronal activity returned to basal levels after exposure to pups. The data suggest that male mouse pheromones increase serotonergic and dopaminergic neuronal activity in the MPOA, but that dopamine and serotonin levels are tightly regulated within strict parameters dependent on what physical stimuli the female is receiving. Changes in prolactin levels are associated with altered responses to anxiety. There is an increased risk of anxiety and depression with sustained periods of hyperprolactinemia, and in the postpartum period, where there are fluctuations in prolactin levels, there is an increased risk of mood disorders. As pheromones change both serum and brain prolactin levels and prolactin modulates anxiety, we hypothesised that female mice exposed to pheromones would show altered behavioral responses to a standardized test of anxiety. We found that male pheromone-exposed mice showed decreased levels of anxiety on an elevated plus maze compared to individually housed controls. Female mice exposed to female pheromones displayed 2 disparate responses to the plus maze. One female from each cage showed increased anxiety, while her cage-mate showed decreased anxiety, yet both groups of female mice showed impaired maternal behavior. We infer, that in this model, male pheromones decrease anxiety, but anxiety and expression of maternal behavior are not directly correlated. The major signal transduction pathway activated by prolactin binding to its receptors in the brain is the JAK/STAT signalling pathway, and in some neurons, in particular, the STAT5B pathway. The expression of prolactin and its receptor affect maternal behavior in mice. Therefore, we hypothesised that if the JAK/STAT STAT5B pathway is involved in maternal behavior, then STAT5B-deficient mice would have altered maternal behavior. We found that there were no significant differences in expression of full maternal behavior between the STAT5B-deficient mice and wild-type controls. The data suggest that STAT5B is not required for normal expression of maternal behavior. We propose that the prolactin-mediated pheromonal increase in neurogenesis, alteration in monoamine synthesis, and alteration of prolactin and prolactin receptor mRNA levels facilitate expression of enhanced maternal behavior. We further propose that the pheromonal decrease in anxiety does not mediate enhanced maternal behavior. In addition, we propose that prolactin does not mediate maternal behavior through STAT5B. While pheromones have previously been reported to exert powerful actions on the reproductive system, these results demonstrate for the first time that male pheromones potentially complement the prolactin-mediated establishment of maternal behavior.

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12

Creighton, J. A. „Prenatal maternal stress in Mus musculus : effects on the offspring and the role of the mother“. Thesis, Keele University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355591.

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13

Chura, Lindsay R. „The effect of chronic and acute maternal stress on expression of placental barrier genes in the rat /“. Connect to online version, 2006. http://ada.mtholyoke.edu/setr/websrc/pdfs/mhc/2006/143.pdf.

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14

Johnston, Zoë Claire. „The human fetal adrenal gland and the influence of maternal smoking“. Thesis, University of Glasgow, 2018. http://theses.gla.ac.uk/38978/.

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The human fetal adrenal cortex is highly active, producing large amounts of Δ5 androgens. Together with the placenta, the fetal adrenal cortex regulates circulating progesterone, estrogen and corticosteroids in the fetus and has a major effect on maternal steroid levels. At birth, production of adequate aldosterone and cortisol are essential for survival, and shortly after birth in the human the cortex undergoes rapid remodelling. Catecholamines, produced by the adrenal medulla are also vital to the body’s ability to respond to stress, and regulate metabolic processes and blood pressure. Normal development of both the cortex and medulla of the human fetal adrenal are therefore critical for post-natal human endocrinology and health. Despite this, adrenal development and function during fetal life is poorly understood due both to the inherent difficulties in obtaining and studying human samples and to the unique nature of human adrenal/endocrine developmental which means animal models are of limited value. While poorly understood, the processes involved in fetal development are highly regulated although they can be disrupted by exposure to environmental chemicals or endocrine disruptors. Exposure to maternal smoking, for example, can disrupt normal fetal programming and has been linked with an altered postnatal stress response in the offspring, as well as a higher risk of developing cardiovascular disease, diabetes, and metabolic syndrome in adult life. These programming effects point to the possible involvement of the human fetal adrenal gland in the post-natal pathologies associated with maternal smoking. The aims of the studies described here were to develop a method to measure 26 steroids by liquid chromatography mass spectrometry (LC/MS) from samples, from which RNA and protein were also extracted, in order to make optimal use of small amounts of human tissue and use this method, and others, to examine the development and steroidogenic capacity of the human fetal adrenal cortex as well as the migration and development of the pheochromoblast cells which will go on to form the adrenal medulla. The influence of maternal smoke-exposure was also examined in these tissues. Additional aims of a set of in vitro studies were to examine the effects of cigarette smoke extract (CSE) and its components on the steroidogenic capacity of a human pluripotent adrenocortical cell line, as well as the influence of placental steroids and their withdrawal. 109 human fetal adrenals were obtained from elective terminations (REC 04/S0802/21) of second trimester fetuses between 11-21 weeks of gestation. Fetuses were grouped according to sex, gestational age and maternal smoking. Cortical steroids extracted from these adrenals were quantified by LC/MS. Cortical and medulla development was examined by measurement of key elements of the steroidogenic, catecholaminergic, and angiogenic pathways using real-time PCR (RT-qPCR), western blot and immunohistochemistry. Statistical analysis of the data was carried out using generalised linear models with age, sex and maternal smoking status as covariates. For in vitro smoke-exposure experiments, H295R cells were cultured for 3 full days in the presence of cotinine, nicotine, or CSE, and stimulated with forskolin. For examinations of the effects of placental steroids, cells were cultured in the presence of estrogen and/or progesterone for 4 days followed by an additional 4 days of culture without added steroids. Steroids and mRNA transcript levels from cells were measured by ELISA, LC/MS and RT-qPCR. Data was analysed using mixed-effects general linear models. The most abundant steroid (ng/mg of tissue) in the human fetal adrenal was pregnenolone, followed by dehydroepiandrosterone-sulphate and 17-hydroxyprogesterone and levels of these steroids were similar between male and female fetuses. Cortisol was present in all adrenals examined although aldosterone was undetected. This data suggests adrenal regulation of circulating fetal ACTH remains a factor in development of congenital adrenal hyperplasia during the 2nd trimester while lack of aldosterone probably explains salt-wasting disorders frequently seen in extreme preterm neonates. Fetal plasma levels of ACTH, intra-adrenal levels of progesterone, 17α-hydroxyprogesterone and 16α-hydroxyprogesterone and adrenal transcript levels of the transcription factors GATA-6 and NR5A1 were increased by maternal smoking. However, plasma and intra-adrenal cortisol, and intra-adrenal DHEAS were unaffected. The enzymes involved in catecholamine biosynthesis were all highly expressed in the developing medulla. Migrating prechromoblast cells were clearly visible in the adrenal fetal zone through H&E staining and could be categorised into noradrenaline- and adrenaline-producing cells by immunohistochemistry for tyrosine hydroxylase and phenylethanolamine-N-methyl transferase. Maternal smoking was also associated with increased levels of PHOX2B transcript, a transcription factor involved in the maturation of chromaffin cells. In cell culture experiments, levels of CYP11A1, CYP17A1, CYP21A2, HSD3B, PGR and ESR2 transcripts were all significantly reduced in cells exposed to CSE. The effects of CSE-exposure on steroid production was variable but pregnenolone and progesterone production was highly stimulated under basal conditions, indicating that CSE has both cell-stimulatory and cell-inhibitory effects. Estrogen and progesterone exposure also had variable effects on steroid production by the cells, depending on other stimulatory factors, and results indicate that other placental factors, in addition to placental steroids, are likely to play a role in cortical remodelling after birth. In conclusion, the studies described here have comprehensively examined the steroidogenic capacity of the human fetal adrenal cortex during the second trimester and have begun to characterise the development and migration of the pheochromoblasts. The results described here provide an understanding of normal development of the steroidogenic capacity of the human fetal adrenal during the second trimester, as well as some of the pathologies associated with abnormal adrenal development. The effects of maternal smoking on the processes examined were not marked, however the disruption of steroid production or dysregulation of transcription factors may lead to changes in adrenal function in postnatal life.

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15

D'Asti, Esterina 1984. „Maternal dietary fat intake alters the neonatal stress response and metabolic profile in the offspring : participation of the endocannabinoid system?“ Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111554.

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Endocannabinoids are products of phospholipid-derived arachidonic acid that regulate hypothalamus-pituitary-adrenal axis activity. We hypothesize that differences in the quality and quantity of maternal dietary fat will modulate the neonatal phospholipid arachidonic acid content of the brain affecting the stress response via differences in endocannabinoid concentration of stress-activated brain areas. Dams were fed a 5% (C) or 300.10 fat diet rich in either n-6 (C, HF) or n-3 (HFF) fat during the perinatal period. PND4-5 HFF milk displays a reduced n-6/n-3 ratio compared to C and HF milk. PND10 hypothalamic and hippocampal PL AA levels are reduced in HFF pups relative to C and HF offspring; and predict endocannabinoid levels in a region-specific manner. In all pups pre-treated with an endocannabinoid receptor antagonist (AM251) or an inhibitor of the endocannabinoid degradative enzyme (URB597), basal and stress-induced ACTH secretion dose-dependently increased. Moreover, HFF pups exhibited a tendency towards reduced AM251 sensitivity under stressful conditions. These data suggest that the nature of perinatal dietary fat can differentially influence neonatal brain arachidonic acid levels and their endocannabinoid derivatives; and endocannabinoid signaling may be altered between diet groups since pups exhibit differences in sensitivity to endocannabinoid receptor blockade.

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16

Aaron, Elizabeth Mae. „Maternal and Child Characteristics Predicting Protective Parenting: Cognition as a Mechanism“. Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1624378278091593.

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17

Howdeshell, Kembra L. „Effects of exposure to environmentally-relevant levels of bisphenol A on mouse reproductive physiology and maternal behavior /“. free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3060107.

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18

Courant, Geneviève Thérèse. „The effect of exercise during pregnancy and lactation on maternal food intake, body weight and body composition, and on lactation performance in rats“. Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26193.

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During pregnancy, body fat stores increase in part to subsidize the high energy cost of lactation. One effect of exercise, on the other hand, is to lower percent body fat. The effect of exercise during pregnancy and lactation on body fat, and on body composition in general, is not well documented. There is also a paucity of data on the effect of exercise during these physiological states on food intake and body weight. If exercise during pregnancy decreases body fat stores, would lactation performance subsequently be compromised? This study was designed to determine the effect of moderately strenuous aerobic exercise, during rat pregnancy and lactation, on food intake, body weight, body composition and lactation performance. Virgin female Sprague-Dawley rats were divided into exercised (n=40) and sedentary (n=40) groups. Exercising rats were trained over three weeks to run on a treadmill at 30 m/min, 2 hours/day, 5 days/week. Within each group, two subgroups were then mated and three subgroups remained as virgin age controls (n=8 per subgroup). Of the mated subgroups, one was terminated within 24 hours of parturition and the other on day 14 of lactation. Subgroups of virgin sedentary and exercising controls were terminated at times corresponding to each of mating, parturition and day 14 of lactation of mated animals. Carcasses were assayed for fat, water, ash and protein. Ad libitum food intake and body weight were monitored throughout the study, as was the weight gain of pups of lactating dams. MANOVA showed the effect of activity to be significant on food intake at week three of training and during the pregnancy period (p<0.00l) and at week one (p<0.0l) and two (p<0.05) of lactation. The effect of activity was highly significant (p<0.00l) on body weight from week three of training and throughout the pregnancy and lactation periods, as well as on the percent fat, water and ash of the rat carcasses. Post hoc multimean comparisons (Scheffe) at the p<0.05 level revealed that exercise resulted in a significant increase in the food intake of virgin rats, and nonsignificant increases in the food intake of pregnant and lactating rats. Body weights of virgin, pregnant and lactating exercising rats were significantly greater than their respective sedentary controls. Despite their heavier body weights and greater food intake, the estimated carcass energy content of exercising animals was lower than that of sedentary animals. This finding was reflected in the carcass composition whereby exercising rats, whether virgin, pregnant or lactating, contained consistently less fat and more water than sedentary controls. At parturition, pregnant animals contained significantly less fat, more water and more ash than sedentary pregnant controls. After 14 days of lactation, there were no significant differences in carcass composition between exercising and sedentary dams. However, lactating rats, whether exercising or sedentary, catabolized approximately 50 percent of the body fat present at parturition. Pup weight gains were not significantly different between exercising and sedentary dams. From these findings it was concluded that the effect of exercise during pregnancy and lactation on food intake, body weight and body composition was comparable to its effect in non-gravid rats. Moderately strenuous exercise during pregnancy prevented the increase in body fat deposition normally present at this time. Despite these depleted fat stores, the energy supplied by the mobilization of the remaining fat and the increase in food intake was adequate to support normal pup growth.
Land and Food Systems, Faculty of
Graduate

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19

Dowdall-Smith, Shannon M. „Feeding practices of mothers : the process of learning and perceptions of health : a dissertation /“. San Antonio : UTHSC, 2007. http://proquest.umi.com/pqdweb?did=1324383501&sid=1&Fmt=2&clientId=70986&RQT=309&VName=PQD.

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20

Sivakumar, Kavitha. „The impact of maternal obesity and gestational diabetes mellitus on adipose tissue and placental derived adipocytokines“. Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/58490/.

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Pregnancy; a natural insulin resistant state; becomes exaggerated when complicated by obesity and gestational diabetes (GDM). Both obesity and GDM are associated with severe maternal and fetal complications as well as with increased risks of obesity in the offspring later in life. Little work has been performed on the levels of adipokines in lean, obese and diabetic pregnancy. This study aimed to explore the roles of three adipokines; namely, Adipsin, Acylation stimulating protein and Fibroblast Growth Factor-21, all of which are involved in insulin resistant and dysmetabolic states such as obesity and type 2 DM. We hypothesized that these adipokines might play a role in pregnancy. A cohort of Caucasian pregnant women undergoing elective caesarean section was studied. Clinical parameters were assayed as well as circulating maternal and fetal levels of adipsin, ASP and FGF21. Paired samples of fat and placental tissue were taken for explant studies to measure secreted Adipsin, ASP and FGF21 levels. Cord levels of adipsin and ASP were significantly elevated in the offspring of obese and diabetic mothers compared to their lean controls. Plasma FGF21 levels were significantly higher in GDM compared to lean controls. FGF21 levels in cerebrospinal fluid (CSF) were also measured and a CSF/Plasma ratio calculated. I have identified the human placenta as a source of adipsin, ASP and FGF21. More specifically, I have shown that placental Hofbauer cells (macrophages) produce adipsin and ASP. This is the first time secretion of adipsin and ASP by Hofbauer cells has been demonstrated. I conjecture a role of these macrophages in lipid metabolism at the materno-fetal interface. Also, I describe that GDM mothers have higher CSF FGF21 as compared to controls but the CSF:plasma ratio of FGF21 was lower in GDM mothers, potentially suggesting an alternative reason for and contributing to hyperglycaemia in GDM.

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21

Smith, Gordon C. S. „The expression of prostanoid receptor genes in uterine and fetal tissues : studies in the maternal and fetal baboon and the fetal and neonatal lamb“. Thesis, University of Glasgow, 2000. http://theses.gla.ac.uk/40962/.

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1. The aim of this project was to determine whether advancing gestational age and parturition were associated with alteration in the relative level of expression of genes encoding prostanoid receptors in key uterine and fetal tissues. I also sought to determine whether advancing gestational age and parturition were associated with alteration in the expression of genes encoding lipoxygenase (LOX) enzymes in key intra-uterine tissues. 2. Caesarean hysterectomy was performed on 15 pregnant baboons in the last third of pregnancy. Samples of myometrium (from multiple uterine sites), cervix, decidua and chorion were obtained. In addition, the ductus arteriosus was obtained from nine fetal baboons, 28 fetal lambs and 4 neonatal lambs. Expression of genes was studied using Northern blot analysis and in situ hybridization. Expression of genes was quantified by Northern analysis as a ratio of the signal for the gene of interest to each of three housekeeping genes (glyceraldehyde-3-phosphate dehydrogenase [GAPDH], beta-actin and cyclophilin). Statistical comparison of the effects of gestational age and labour was performed using linear regression. Student's t-test, repeated measures analysis of variance and analysis of covariance, as appropriate. 3 Initial studies of animals not in labour using cDNA probes demonstrated transcripts of similar size to the human genes for prostanoid EP2, EP3, EP4, and FP receptor mRNA using Northern blot in myometrium. Myometrium from the lower uterine segment (LUS) had greater expression of EP2 receptor mRNA and less expression of EP3 mRNA compared with the fundus and corpus. However, similar levels of EP4 and FP receptor mRNA were observed comparing the fundus and LUS. Expression of EP2, EP3 and EP4 receptor mRNA were also detected in cervix, decidua and chorion. EP2 mRNA was most abundant in cervix, EP3 was most abimdant in myometrium and EP4 mRNA was most abundant in decidua. The variation in myometrial expression of genes encoding EP receptor sub-types paralleled the contractile responses of paired samples (reported elsewhere). 4 When expression of prostanoid receptor genes was studied in myometrium obtained from animals both in labour and not in labour and the techniques employed were optimized (principally the use of riboprobes), transcripts of similar size to the human genes were detected for prostanoid EP1, EP2, EP3, EP4, IP, FP and TP receptor mRNA using Northern blot. There were no gestational age related changes in expression of these genes. Expression of EP1, EP3 and IP receptor mRNA was significantly higher in myometrium from the fundus (compared with lower segment) whereas EP2 gene expression was significantly lower in the fundus. Labor was associated with a reduction in the regional variation of both EP2 and IP receptor gene expression, but not EP1 and EP3 expression. Labor was also associated with an overall lower level of expression of EP2 receptor mRNA. 5 When expression of prostanoid receptor genes was studied in cervix obtained from animals both in labour and not in labour, clear signals which were similar in estimated size to the human genes were detected by Northern analysis for EP1, EP2, EP3, EP4, FP, IP and TP receptors. Expression of the gene encoding the prostanoid EP? receptor increased with advancing gestational age prior to labor. Expression of the EP2, FP and TP receptor genes was much lower in animals that were delivered during spontaneous labor than in animals which were not in labor. 6 When expression of prostanoid receptor genes was studied in decidua and chorion obtained from animals both in labour and not in labour, expression of the genes encoding the EP1 and FP receptor in decidua and the EP4 receptor in chorion was lower with advancing gestational age. Expression of the EP? receptor gene was lower in labour in decidua, whereas expression of the IP receptor gene was higher in labour in both decidua (2-fold) and chorion (4-fold).

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22

Ho, Dao H. „Morphological and physiological developmental consequences of parental effects in the chicken embryo (Gallus gallus domesticus) and the zebrafish larva (Danio rerio)“. Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9086/.

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Cardiac, metabolic and growth response of early-stage chicken embryos to perturbations in yolk environment was investigated. Also, effects of parental hypoxia exposure on hypoxia resistance, thermal tolerance and body length of zebrafish larvae were investigated. In the first study, thyroxine, triiodothyronine and testosterone produced differential effects on heart rate and development rate of chicken embryos during the first 4 days of development. Triiodothyronine caused a dose-dependent increase in heart rate when applied at 40 or 70 hours of age, while thyroxine caused a dose-dependent increase in heart rate when applied at 40 hours only. Testosterone and propyl-thiouracil (deiodinase antagonist) did not have an effect on heart rate. Development rate was not changed by thyroxine, triiodothyronine, testosterone or propyl-thiouracil, which suggested that heart rate changes did not result from changes in embryo maturity. In the second study, chicken embryos exposed to yolks of different bird species during early-stage embryonic development showed changes in heart rate, mass-specific oxygen consumption and body mass that scaled with the egg mass, incubation period length, and yolk triiodothyronine and testosterone levels of the species from which yolk was derived. In the third study, this phenomenon was investigated between layer and broiler chickens. Heart rate, oxygen consumption and body mass of broiler and layer embryos were significantly changed by a breed-specific change in yolk environment. Yolk triiodothyronine and testosterone concentrations of broiler and layer eggs did not suggest that these hormones were responsible for physiological and morphological changes observed. The final study demonstrated that hypoxia resistance and body lengths, but not thermal tolerance of zebrafish larvae was increased by parental hypoxia exposure.

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23

Rojas-Rodriguez, Raziel. „Adaptations of Adipose Tissue Expandability in Gestation are Associated with Maternal Glucose Metabolism“. eScholarship@UMMS, 2019. https://escholarship.umassmed.edu/gsbs_diss/1048.

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Pregnancy induces maternal metabolic adaptations including mild glucose intolerance and weight gain in order to support fetal development and lactation. Adipose tissue (AT) function in gestation is featured by reduced insulin sensitivity and fat mass accrual which partly accounts for the weight gain in pregnant women and adaptation of glucose metabolism. A common metabolic pregnancy complication is gestational diabetes mellitus (GDM), a disease characterized by impaired glucose tolerance with onset in gestation. However, the relationship between AT expandability and glucose metabolism in gestation is not well understood. The goal of this thesis was to investigate the adaptations of human AT expansion induced by pregnancy, how these changes are reflected in pregnancies complicated with GDM and characterize a mouse model to study the mechanisms underlying this disease. This dissertation illustrates that pregnancy promotes AT expandability by a signaling mechanism between placental pregnancy-associated plasma protein-A (PAPP-A) and AT- insulin-like growth factor binding protein-5 (IGFBP5). In addition, gravidas with GDM showed impaired AT expansion. Studies investigating the relationship between PAPP-A and glycemic state demonstrated that low levels of PAPP-A in the 1sttrimester are highly associated with the development of GDM. Moreover, PAPP-A knockout mice exhibit reduced insulin sensitivity and impaired AT growth exclusively in gestation. These results expand the knowledge of AT biology in gestation and have the potential to improve maternal care by proposing PAPP-A as an early biomarker and possible therapeutic for GDM. It also introduces a new mouse model to study the etiology of gestational diabetes.

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Caldji, Christian. „Early environmental regulation of neural systems mediating fearfulness“. Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103367.

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Postnatal handling of rat litters during the first week of life greatly decreases behavioural fearfulness to novelty in the adult offspring. Our first question was to what extent the Benzodiazepine/GABAA receptor complex, a system critical for the expression of fear, might be involved in mediating the observed reduced fearfulness in handled animals (H). Benzodiazepine receptor (BZ) binding was reduced in the amygdala and locus coeruleus (LC), regions important for the expression of fear in non-handled (NH) and maternally separated animals (MS). Moreover, levels of the mRNA for the gamma2 sub-unit of the GABAA receptor complex, which confers high affinity BZ binding, were higher in the amygdaloid nuclei as well as in the LC of handled compared with both NH and MS animals.
Studies with the handling paradigm have lead to the idea that variations mother-pup interactions may actually be the cause of the handling effects. As adults, the offspring of mothers which exhibited high levels of licking/grooming and arched-back nursing (LG-ABN) showed substantially reduced behavioral fearfulness in response to novelty compared to the offspring of low LG-ABN mothers. In addition, the adult offspring of the high and low LGABN mothers showed the same receptor and molecular profiles as H and NH adult offspring. Corticotropin releasing factor (CRF) and alpha2 norepinephrine receptor levels, additional receptor systems thought to be important in the expression of fearfulness, differed in these animals too. Adoption studies give further support to the maternal hypothesis in the finding that the expression mRNA for the gamma2 sub-unit of the GABAA receptor complex can be differentially expressed as a result of different offspring to mother combinations.
Taken together, these findings suggest that early life events (ie: naturally occurring differences in maternal care) during the first few days of life have long-term effects on the development of central neurotransmitter systems, which mediate the expression of fearfulness to novelty.

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25

Pace, Brian A. „Maternal effects on multiple generations of Helianthus annuus crop-wild hybrid seed: overwinter germination, dormancy and survival“. The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354696610.

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26

Jeffrey, Jennifer D. „The Roles of Social Status, Maternal Stress, and Parental Investment in Modulation of Hypothalamic-Pituitary-Interrenal Axis Function in Teleost Fish“. Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31628.

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In teleost fish, the main glucocorticoid stress hormone, cortisol, is released via the hypothalamic-pituitary-interrenal (HPI) axis. This thesis examined the premise that social status, maternal experience, and reproductive status affect HPI axis function in fish. Social stress in juvenile rainbow trout (Oncorhynchus mykiss) chronically elevates circulating cortisol levels. In this thesis, social subordinance as well as exogenous cortisol treatment resulted in decreased plasma adrenocorticotropic hormone (ACTH) levels, consistent with a negative feedback role of cortisol in modulating HPI axis activity. At the target tissue level, liver glucocorticoid receptor 2 (GR2) mRNA and total GR protein levels were lower in subordinate fish. Although subordinate fish exhibited elevated resting cortisol levels, cortisol and glucose responses to an acute stressor were attenuated. Using an in vitro head kidney preparation, this attenuated cortisol response was attributed to lower ACTH-stimulated production of cortisol. By contrast, dominant status regulated genes associated with cortisol biosynthesis. The consequences of maternal social status on offspring HPI axis function were investigated in zebrafish (Danio rerio). At 48 hours post-fertilization (hpf), when de novo cortisol synthesis becomes possible, larvae of dominant females exhibited lower baseline cortisol levels accompanied by lower mRNA levels of corticotropin-releasing factor and cytochrome P450 side chain cleavage enzyme. Offspring of subordinate females exhibited attenuated stress-induced levels of cortisol at 144 hpf, perhaps as an adaptive response to maternal stress experience. Finally, modulation of HPI axis function was explored as a mechanism underlying attenuation of the stress response during early paternal care in smallmouth bass (Micropterus dolomieu). In response to a stressor, males guarding free-swimming fry but not eggs elevated plasma ACTH and cortisol as well as mRNA levels of key HPI axis genes. These results point to a hypoactive HPI axis in males during early parental care as a mechanism for resistance to stress in these fish. Collectively, the results of this thesis emphasize the adaptive plasticity of the HPI axis. Activity of the HPI axis in teleost fish can be modulated by the individual’s experience (e.g., social status) or circumstances (e.g., parental care), as well as by maternal stress.

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27

Comstock, Sarah Michelle. „Examining the Effect of Maternal High-Fat Diet Consumption on the Physiology and Pancreas Development of Fetal and Juvenile Nonhuman Primate Offspring“. PDXScholar, 2012. https://pdxscholar.library.pdx.edu/open_access_etds/551.

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The purpose of these studies was to investigate the impact of high-fat diet (HFD) exposure during pregnancy and the early post-natal period on fetal and post-natal development of the endocrine pancreas of the Japanese macaque. Specifically I hypothesized that the HFD would alter islet morphology and lead to disturbances in glucose homeostasis in these animals. Adult female Japanese macaques were placed on either a control (CTR) or HFD diet for 4 years. Fetuses were collected at gestational day 130 (G130), while other offspring from the CTR and HFD mothers were carried to term. After birth, infant animals were maintained with their mothers on the same diet then weaned onto either the CTR or HFD diet for five months. Animals were studied up to 13 months of age, yielding 4 postnatal groups: CTR/CTR, CTR/HFD, HFD/CTR and HFD/HFD. Pancreata were collected from these offspring for gene expression and immunohistochemical analysis. Physiological measurements, including body weight, body fat percentage, fasting glucose, insulin, glucagon and response to intravenous glucose tolerance tests (IVGTTs) and an intravenous insulin tolerance test (IVITT) were collected from the post-natal offspring. Total fetal islet mass and β cell mass were not changed, but α cell mass was significantly decreased in HFD fetuses, leading to a significant increase in the β cell to α cell ratio in HFD fetal offspring. The HFD offspring displayed a significant change from CTR offspring in expression of genes involved in glucose homeostasis and islet neogenesis, including PDX1, NeuroD, Glucokinase and Glut2. Postnatal HFD animals were significantly heavier than CTR offspring and had increased adiposity by 6-7 months of age. There was no significant effect on fasting or stimulated insulin secretion at this time point, but HFD offspring were significantly insulin resistant just prior to weaning. At 13 months of age, basal and glucose-stimulated insulin secretion were elevated in HFD/HFD animals and the CTR/HFD group displayed moderate insulin resistance. There was also a significant sex effect, with males from the HFD/CTR and HFD/HFD group having increased body weight and elevated fasting glucose. Although pancreata from both the HFD/HFD and CTR/HFD animals displayed significant changes in expression of genes involved in glucose homeostasis, the pattern was distinct for the two groups. Islet mass was also elevated in both of these groups; yet, HFD/HFD only displayed an increase in β cell area, while CTR/HFD had a concomitant increase in α cell area, which served to normalize the β cell to α cell ratio to control levels. In contrast, the HFD/HFD group exhibited a 40% increase in the β cell to α cell ratio. These studies demonstrate that in-utero exposure to a HFD leads to decreased α cell plasticity in response to chronic post-natal HFD consumption. Animals exposed to the HFD during pregnancy and the early post-natal period become insulin resistant, but remain normoglycemic. HFD consumption during the post-weaning period causes similar complications in glucose homeostasis and islet mass in both the CTR/HFD and HFD/HFD animals. However, there are distinct differences in the molecular and cellular adaptive response between these two groups.

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28

Erkinaro, T. (Tiina). „Fetal and placental haemodynamic responses to hypoxaemia, maternal hypotension and vasopressor therapy in a chronic sheep model“. Doctoral thesis, University of Oulu, 2006. http://urn.fi/urn:isbn:9514281659.

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Abstract Knowledge of the effects of maternally administered vasopressors on human fetal and placental haemodynamics is sparse and limited to elective Caesarean deliveries in uncomplicated pregnancies. We hypothesized that, after short-term fetal hypoxaemia, which activates fetal cardiovascular compensatory mechanisms, treatment of maternal hypotension with ephedrine or phenylephrine results in divergent responses in fetal and placental haemodynamics. Chronically instrumented near-term sheep fetuses with either normal placental function or increased placental vascular resistance following placental embolization were exposed to two subsequent periods of decreased fetal oxygenation caused by maternal hypoxaemia and epidural-induced hypotension. The fetuses that underwent placental embolization were also chronically hypoxaemic. Fetal and placental haemodynamics were assessed by invasive techniques and by noninvasive Doppler ultrasonography. Our results show that umbilical artery blood flow velocity waveforms cannot be used to derive information of fetal cardiac function. Furthermore, the changes in placental volume blood flows and vascular resistances caused by maternal vasopressor treatment cannot be reliably recognized based on uterine and umbilical artery pulsatility index values. In response to acute hypoxaemia, a fetus with normal placental function redistributes its right ventricular cardiac output from the pulmonary to the systemic circulation and is able to increase its combined cardiac output, with a concomitant relative decrease in the net forward flow through the aortic isthmus. However, fetal haemodynamic responses to subsequent hypoxaemic insults may vary. Furthermore, the compensatory responses of fetuses with increased placental vascular resistance differ from those of normal fetuses. In these fetuses, repeated episodes of a further decrease in oxygenation lead to lactataemia. The effects of ephedrine on uteroplacental and umbilicoplacental circulations were more favourable than those of phenylephrine. Ephedrine restored the changes in fetal cardiovascular haemodynamics caused by maternal hypotension to the baseline conditions in both embolized and nonembolized fetuses. Phenylephrine did not reverse fetal pulmonary vasoconstriction or the relative decrease in the net forward flow through the aortic isthmus. Moreover, fetal left ventricular function was impaired by phenylephrine. Although no significant differences in fetal acid-base status were observed in fetuses with normal placental function, the lactate concentrations of the embolized fetuses increased further when maternal hypotension was treated with phenylephrine.

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29

Novak, Matthew S. „A model experimental system for studying prenatal stress in pigtailed macaque monkeys (Macaca nemestrina) /“. Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/9093.

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30

Nesbitt, Catherine. „Variations in maternal lickinggrooming influences both dam and offspring's hypothalamic-pituitary-adrenal hormone profile“. Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111562.

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Pup directed maternal licking and grooming (LG) increases with corticosterone (CORT) supplimentation (Rees et al 2004). Increases in LG lead to an attenuation of the adult offspring's HPA response to stress (Liu et aI1997). Similarly, Neonatal increases in glucocorticoids lead, in adulthood, to the same attenuation of the HPA stress response (Catalani et aI1993). We hypothesize that dams exhibiting increased LG will have increased circulating CORT, and this increase will be reflected in their offspring. This thesis characterizes the HPA hormone profile adrenocorticotropic hormone (ACTH), CORT & Corticosterone Binding Globulin (CBG) in High LG (H) and Low LG (L) litters, 5 days postpartum (P4). Furthermore pup plasma CORT levels are determined at (P) 3,4,6,10 & 14. Finally P10 Hand L LG ACTH, CORT & CBG will be assessed after stress. RESULTS: H compared to L LG dams have significantly increased plasma CORT (p=0.03). At P4, H LG offspring have significantly increased plasma CORT (p=0.03) and significantly decreased plasma ACTH (p=0.04) as compared to L LG offspring. Plasma CBG levels are significantly lower in H compared to L LG offspring (p=0.01) at the same age. Across the Stress Hyporesponsive Period (SHRP) H LG offspring had significantly increased plasma CORT (p= 0.00) compared to L LG offspring at P3. Challenged with a stressor at P10, H LG offspring have an exaggerated plasma CORT response (p=0.00). This data suggests increases in plasma CORT in the dams leads to increased CORT in the high offspring, contributing perhaps to a more mature stress response at P10.
Key word abbreviation: (1) CORT - CORTicosterone, (2) ACTH - AdrenoCorticoTropin releasing Hormone, (3) CBG - Corticosteroid Binding Globulin, (4) SHRP - Stress Hypo-Responsive Period, (5) P - Post-natal day, (6) HPA - Hypothalamic-Pituitary-Adrenal, (7) LG - Licking/Grooming, (8) ADX/OVX - ADrenalectomized/OVarectomized.

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31

Marais, Lelanie. „The potential of exercise to reverse stress induced abnormalities in the rat brain“. Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/3188.

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Thesis (PhD (Biomedical Sciences. Medical Physiology.))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: Adverse experiences during early life causes alterations in the development of the central nervous system structures that may result in abnormal functioning of the brain. It is well known that, in humans, adverse early-life experiences such as social separation, deprivation, maternal neglect and abuse increase the risk of developing psychiatric disorders, such as depression, later in life. We used maternal separation in the rat as a model for early life stress to firstly determine how different brain systems are dysregulated by this stressful experience and additional chronic or acute stress during adulthood. Rat pups were separated from their mothers on postnatal day 2-14 for 3 hours per day while control rats were normally reared. The behavior, stress response, neurotrophin, apoptotic marker and serotonin levels in the ventral hippocampus, striatum and frontal cortex were measured during adulthood. A different group of maternally separated rats were allowed chronic voluntary exercise and similar measurements were done to determine whether exercise was able to normalize the deficits caused by early life stress. Differentially expressed cytosolic proteins of the ventral hippocampus of maternally separated rats versus normally reared rats were also identified. Protein expression levels of maternally separated rats that received chronic voluntary exercise or escitalopram treatment were subsequently determined to unravel the mechanism of therapeutic action for these two interventions. We found that maternal separation increased the baseline corticosterone response of rats and induced a blunted adrenocorticotropin hormone after acute restraint stress. Baseline neurotrophin levels were significantly decreased in the ventral hippocampus. Maternal separation followed by chronic restraint stress during adulthood resulted in increased depressive-like behavior compared to control rats. Maternal separation alone or followed by acute restraint stress during adulthood induced changes in apoptotic marker expression in the striatum and frontal cortex. In rats subjected to maternal separation and chronic restraint stress during adulthood, we found that chronic voluntary exercise decreased their depressive-like behavior and increased brain derived neurotrophin levels in the striatum. Serotonin levels were not affected by maternal separation, but chronic voluntary exercise increased serotonin in the ventral hippocampus of normally reared rats. Maternal separation induced a number of changes in the expression of cytosolic proteins and these stress-induced changes were identified in proteins relating to cytoskeletal structure, neuroplasticity, oxidative stress, energy metabolism, protein metabolism, and cell signaling. Chronic voluntary exercise was able to restore the expression levels of a number of proteins affected by maternal separation that increased the risk for neuronal death. When comparing the efficacy of exercise to that of escitalopram treatment it was evident that, in contrast to exercise, escitalopram targets a different subset of proteins affected by maternal separation, except for a few involved in energy metabolism pathways and neuroprotection. In this study we have shown that chronic voluntary exercise has therapeutic effects in maternally separated rats, decreasing depressive-like behavior, increasing neurotrophin expression and restoring cytosolic protein expression that were dysregulated by early life stress.
AFRIKAANSE OPSOMMING: Negatiewe stresvolle ervarings gedurende die vroeë stadium van ‘n mens se lewe veroorsaak veranderinge in die ontwikkeling van breinstrukture en het ‘n nadelige uitwerking op die funksionering van die brein. Dit is bekend dat stresvolle ervarings in kinders, byvoorbeeld sosiale afsondering, verwaarlosing en mishandeling, die risiko vir die ontwikkeling van psigiatriese steurings soos depressie gedurende volwassenheid kan verhoog. In hierdie studie gebruik ons moederlike skeiding van neonatale rotte as ‘n model vir vroeë lewensstres om te bepaal hoe dit verskillende sisteme in die brein negatief beinvloed, en dan ook die effek van addisionele kroniese of akute stres gedurende volwassenheid. Die neonatale rotte is weggeneem van hulle moeders af vanaf dag 2 tot 14 vir 3 ure elke dag terwyl kontrole rotte by hulle moeders gebly het. Die gedrag, stres respons, neurotrofiene, apoptotiese merkers en serotonien vlakke is gemeet in die ventrale hippokampus, frontale korteks en striatum gedurende volwassenheid. Rotte wat van hulle moeders geskei is, is dan toegelaat om vir ses weke in wiele te hardloop om te bepaal of kroniese vrywillige oefening die negatiewe effekte wat veroorsaak is deur stres kan ophef. ‘n Bepaling van sitosoliese proteien uitdrukking in die ventrale hippokampus is ook gedoen om die uitwerking van moederlike skeiding op proteienvlak vas te stel. Hierdie protein data is dan vergelyk met die van gestresde rotte wat kroniese oefening of escitalopram behandeling ontvang het om die meganisme van werking van beide behandelings te bepaal. Ons het gevind dat moederlike skeiding die rustende kortikosteroon vlakke van rotte verhoog terwyl dit adrenokortikotropien vlakke na akute stres inhibeer. Moederlike skeiding het ook die neurotrofien vlakke in die ventrale hippokampus verlaag en addisionele kroniese stres gedurende volwassenheid het ‘n verhoging in depressie-agtige gedrag veroorsaak. Moederlike skeiding alleen, sowel as gevolg deur akute stress gedurende volwassenheid het ook veranderinge in die uitdrukking van apoptotiese merkers in die striatum en frontale korteks veroorsaak. Kroniese vrywillige oefening na moederlike skeiding en addisionele stres gedurende volwassenheid kon depressie-agtige gedrag verlaag en neurotrofienvlakke in die striatum verhoog. Serotonien vlakke was nie beinvloed deur moederlike skeiding nie, maar oefening in kontrole rotte het serotonien verhoog in die ventrale hippokampus. Moederlike skeiding het heelwat veranderinge in die uitdrukking van sitosoliese proteiene van die ventrale hippokampus veroorsaak wat ingedeel kan word in die volgende funksionele kategorieë: sitoskelet, neuroplastisiteit, oksidatiewe stres, energiemetabolisme, proteinmetabolisme en seintransduksie. Oefening kon die uitdrukking van verskeie stres-geïnduseerde veranderinge in proteiene weer herstel terwyl dit wou bleik asof escitalopram se meganisme van werking op ‘n ander vlak geskied. Ons bevindinge bewys dat kroniese vrywillige oefening ‘n goeie behandeling is na vroeë lewenstres en dat dit depressiewe gedrag verminder, neurotrofien vlakke verhoog en sitosoliese proteien skeiding alleen, sowel as gevolg deur akute stress gedurende volwassenheid het ook veranderinge in die uitdrukking van apoptotiese merkers in die striatum en frontale korteks veroorsaak. Kroniese vrywillige oefening na moederlike skeiding en addisionele stres gedurende volwassenheid kon depressie-agtige gedrag verlaag en neurotrofienvlakke in die striatum verhoog. Serotonien vlakke was nie beinvloed deur moederlike skeiding nie, maar oefening in kontrole rotte het serotonien verhoog in die ventrale hippokampus. Moederlike skeiding het heelwat veranderinge in die uitdrukking van sitosoliese proteiene van die ventrale hippokampus veroorsaak wat ingedeel kan word in die volgende funksionele kategorieë: sitoskelet, neuroplastisiteit, oksidatiewe stres, energiemetabolisme, proteinmetabolisme en seintransduksie. Oefening kon die uitdrukking van verskeie stres-geïnduseerde veranderinge in proteiene weer herstel terwyl dit wou bleik asof escitalopram se meganisme van werking op ‘n ander vlak geskied. Ons bevindinge bewys dat kroniese vrywillige oefening ‘n goeie behandeling is na vroeë lewenstres en dat dit depressiewe gedrag verminder, neurotrofien vlakke verhoog en sitosoliese proteien vlakke kan herstel.

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Vlachava, Maria. „Salmon In Pregnancy Study (SIPS): the effects of increased oily fish intake during pregnancy on maternal and cord blood fatty acid composition, cord blood immunity and atopy outcomes in infants at 6 months of age“. Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/199377/.

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Parallel increases in many inflammatory diseases including atopy over the last 40 years suggest that common environmental changes may be promoting inflammatory immune responses. Modern diets have become increasingly rich in n-6 polyunsaturated fatty acids (PUFAs) and relatively deficient in n-3 PUFAs. These dietary changes are believed to promote a pro-sensitisation, pro-allergic and pro-inflammatory environment. Exposure to such an environment during pregnancy and in the very early life period is considered to influence subsequent patterns of the immature and developing neonatal immune system, and this may contribute to the increase in allergic disease in early life. As allergic diseases often first manifest in infancy, prevention strategies need to be targeted early, even in utero. Epidemiologic and experimental data provide a plausible link between dietary changes and increased incidence of childhood atopic disease. Although there have been studies examining the potential benefits of giving n-3 PUFA-rich fish oil supplements during pregnancy, there are no studies examining the effects of increased consumption of oily fish in pregnancy on neonatal immune responses and subsequent clinical outcomes. The Salmon in Pregnancy Study (SIPS) is the first randomised controlled trial of oily fish intervention during pregnancy. The hypotheses being investigated in SIPS is that increased intake of salmon, a source of long chain (LC) n-3 PUFAs (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), in pregnancy will a) increase maternal LC n-3 PUFA intake, b) increase maternal and infant blood LC n-3 PUFA status, c) modulate fetal/neonatal immune responses and d) lower the risk of infant atopy determined at 6 months of age. The primary outcome measures of SIPS were the clinical signs of atopy in the offspring. Pregnant women (n=123) at high risk of having atopic offspring, and with low habitual intake of oily fish (≤ 2/month) were randomised at 20 weeks of pregnancy to either consuming 2 portions/week of farmed salmon (n=62) or continuing their habitual diet (n=61) until the end of pregnancy. The woman attended a clinic at 20 (n=123), 34 (n=110) and 38 (n=91) weeks of gestation at which fasting blood was collected and a food frequency questionnaire (FFQ) was administered (at 20 and 34 weeks). At delivery umbilical cord blood was collected (n=101) for fatty acid and immunological analysis. Infants attended a clinic at 6 months of age (n=86) for assessment of allergic sensitisation by skin prick testing (SPT) using various allergen extracts and of atopic dermatitis (SCORAD index). Maternal and cord plasma and cord blood mononuclear cell (CBMC) fatty acid compositions were determined by gas chromatography. Neonatal (cord) immune cell subsets were identified by flow cytometry. Ex-vivo cytokine production by CBMC in response to stimulants (allergen, mitogen, and toll-like receptor (TLR) ligands) was determined by cytometric bead array and flow cytometry. Ex-vivo prostaglandin E2 production by CBMC was determined by enzyme-linked immunosorbent assay. Immunoglobin E concentration was measured in cord blood plasma and in 6 month infant blood plasma. Eating oily fish twice a week during pregnancy resulted in a higher maternal intake of LC n-3 PUFAs (both EPA and DHA) and in higher maternal and cord blood plasma status of LC n-3 PUFAs (both EPA and DHA). LC n-3 PUFA content of CBMC was not significantly affected. CBMC production of interleukins-2, -4, -5, and -10 and tumour necrosis factor-α was lower in the salmon group. There was no effect of salmon on the atopic outcomes assessed at 6 months.

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King, Summer Hayes. „Maternal High-Salt Diet During Pregnancy in Sprague Dawley Rats Programs Exaggerated Stress-Induced Blood Pressure and Heart Rate Responses in Adult Female Offspring“. Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2061.pdf.

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Ruhland, Fanny. „Étude comportementale des interactions entre une mère lycose errante, Pardosa saltans (Araneae), et son cocon“. Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1B019/document.

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Les soins parentaux sont observés dans de nombreux taxons et sont exprimés de façon plus ou moins complexe. L’étude de ces comportements chez les arthropodes, en particulier chez les araignées, nous permet de mieux comprendre comment les soins à la progéniture se sont mis en place au cours de l’évolution. Au cours de cette thèse nous avons étudié le comportement d’une espèce errante Pardosa saltans (Lycosidae) vis-à-vis de son cocon, puis de ses jeunes. Nous avons décrit les comportements manifestés par la mère pendant toute la période de soin au cocon (période de développement embryonnaire et postembryonnaire des jeunes). Notre étude a permis de mettre en évidence qu’il existe une ontogenèse comportementale dans le cadre des soins parentaux chez cette espèce. Elle a permis également d’évaluer les dépenses énergétiques subies par la mère pendant cette période. Et enfin nous avons identifié, pour la première fois, les composés chimiques présents à la surface du cocon. Nos expériences montrent que ces composés chimiques associés aux vibrations émises par les juvéniles à l’intérieur du cocon sont utilisés par la mère détecter l’état de développement de sa progéniture
Parental care is widespread among animal kingdom and is more or less expressed. Thus, the study of these behaviours among primitive species, can let us understand how parental behaviours were implemented during evolution. In this thesis we studied maternal behaviour in a wandering spider Pardosa saltans (Lycosidae) with her egg-sac and her young which she actively transports. We have described maternal behaviour towards the egg-sac and highlighted the presence of ontogeny of maternal behavior in this species. Furthermore, we were able to evaluate some of the physiological and ecological investment associated with maternal care of the egg-sac and young. Finally, we have, for the first time, identify chemical compounds on the surface of the silk egg-sac, and placed in evidence the presence of a chemical and vibrational communication between the mother and her cocoon

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Nickelson, Joyce E. „A modified obesity proneness model in the prediction of weight status among high school students“. [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002410.

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Tickle, Jacqueline Amanda. „Engineering neural cells in implantable materials“. Thesis, Keele University, 2017. http://eprints.keele.ac.uk/3774/.

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A key goal in regenerative therapy is to improve outcomes following the devastating consequences of spinal cord injury. Yearly, between 250,000 to 500,000 people suffer permanent injury to the spinal cord. The cost to the individual, their families and society is substantial. Modest success in clinical trials has offered hope. However, there remain a number of challenges still to be met in respect of a combinatorial approach that offers safe delivery of grafts, to promote recovery and regeneration in the injured spinal cord. In this context astrocytes have shown promise as a cell transplant population. This project aimed to develop strategies to engineer astrocytes to improve their repair capacity as a cell transplant population for regenerative applications. Specifically, methods were attempted using applied magnetic fields to i) enhance magnetic nanoparticle mediated gene delivery in primary-derived cortical astrocytes, and ii) achieve high levels of magnetic particle loading and long term retention in cells by tailoring particle magnetite content, improving utility for non-invasive imaging applications. Further, high cell loss during surgical delivery of transplant cells has prompted the need to develop protective cell delivery systems for neural cells. Use of a 3-dimensional collagen hydrogel was investigated for this purpose, and the capacity to image particle labelled intra-gel astrocytes evaluated. The findings show that a tailored combination of magnetic field parameters increased transfection efficiency, and enhanced transgene expression in astrocytes. Second, astrocytes showed rapid, highly efficient but safe accumulation and long term retention of high magnetite content particles. Third, collagen hydrogels offered a protective environment conducive to cell transplant delivery. Finally, within the hydrogel, magnetic particle labelled astrocytes retained their utility for cell tracking by MRI over an extended time frame.

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Senko, Alexander W. (Alexander William). „Transgene-free strategies for wireless control of animal physiology using magnetite nanoparticles“. Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122538.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2019
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 130-141).
Bioelectronic medicines are emerging therapies designed to control human physiology using electrically actuated stimuli instead of drugs. The most famous example is deep brain stimulation (DBS) for Parkinson's disease, in which electrodes are used to control brain activity and prevent tremors. An idealized version of this therapy would use soft materials and be wireless in order to be minimally invasive and cause minimal damage to brain tissue. Magnetic fields are an appealing candidate for wireless therapies because at many frequencies and amplitudes, the human body is similar enough in its magnetic response to vacuum that magnetic fields can penetrate arbitrarily deep. When combined with magnetic nanoparticles of biocompatible iron oxide, which can dissipate heat or produce forces when subjected to applied magnetic fields, magnetic fields can be applied from outside the body and evoke a physiological response within. This thesis describes the synthesis of large disc-shaped magnetic particles which undergo mechanical motion under lower frequency alternating magnetic fields. This mechanical motion enables a new paradigm of activating mechanosensitive ion channels, with increased scalability of the magnetic field apparatuses compared to the high-frequency fields needed to produce heat from magnetic nanoparticles. Wireless magnetic nanoparticle-mediated stimulation has often relied on transgenes, but by choosing tissues that endogenously express the proteins required to detect the physical stimuli (like heat or force) produced by the nanoparticles, it is possible to avoid the need for transgenes. Not relying on transgenes significantly lowers the barrier to clinical translation of this therapy platform.
by Alexander W. Senko.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Materials Science and Engineering

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Mathieson, I. C. „The physiology of plants as influenced by the incorporation into rooting media of refuse materials“. Thesis, Open University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383661.

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Gedi, Mohamed Abdulkadir. „Nutrient composition and digestibility of chloroplast rich fractions from green leaf materials“. Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/43285/.

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Green leaf material is recognized as a good source of many valuable nutrients including vitamins, fatty acids and minerals. Chloroplast-rich-fractions (CRFs) were prepared from green plant species and their nutrient composition compared with the whole leaf materials (WLMs). Digestibility of CRFs from spinach was also compared with the WLM using simulated in vitro oral, stomach and small intestinal conditions. The impact of pancreatic lipase-related protein 2 from guinea pig (gPLRP2) on the hydrolysis of galactolipids compared to neutral lipid, Tributyrin was subsequently determined in vitro. Porcine pancreatic lipase was also used against the same substrates compared to gPLRP2. Furthermore, spinach CRFs and WLMs were fed to zebrafish and the impact of CRFs and WLMs on growth performance and transition of certain compounds into zebrafish body was evaluated. Results indicated that compared with the WLM, the CRFs were enriched in more lipids and fatty acids, and more proteins and amino acids. Spinach CRFs possessed the highest α-tocopherol (62 mg 100 g-1 , dry weight (DW)), β-carotene (336 mg 100 g-1 DW) and lutein (341 mg 100 g-1 DW) contents, whilst grass CRFs had the highest alpha-linolenic acid (ALA) concentration (69.5 mg g-1). Of the minerals, iron was most notably concentrated in CRF. The digestive conditions caused changes in the structure and composition of the material providing some indication of its digestibility and bioaccessibility. Whilst PLRP2 was more active on galactolipids, with moderate reaction against the neutral lipid, pancreatin indicated higher activity on Tributyrin with almost no activity against MGDG. Diets with 10% zebrafish meal reduction improved growth rate with significant reduction in feed conversion ratio (FCR) compared to the control. CRFs diets showed greater ALA content and distinct pigmentation of zebrafish egg and flesh due to the CRF carotenoids. Overall, the results indicated that CRF is a potential digestible source of vital nutrients.

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Brickman, Raredon Micha Sam. „Design and fabrication of physiologic tissue scaffolds using projection-micro-stereolithography“. Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90086.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2014.
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Cataloged from PDF version of thesis.
Includes bibliographical references (pages 65-67).
Recent advances in material processing are presenting groundbreaking opportunities for biomedical engineers. Projection-micro-stereolithography, or PuSL, is an additive manufacturing technique in which complex parts are built out of UV-curable resins using ultraviolet light. The primary strength of PuSL is its capacity to translate CAD files into three-dimensional parts with unusually small feature sizes (~0.5 microns). It is an ideal candidate, therefore, for making tissue scaffolds with sophisticated microscopic architecture. Nearly all multicellular biological tissues display a hierarchy of scale. In human tissues, this means that the mechanics and function of an organ are defined by structural organization on multiple levels. Macroscopically, a branching blood supply creates a patent network for nutrient delivery and gas exchange. Microscopically, these vessels spread into capillary beds shaped in an organ-specific orientation and organization, helping to define the functional unit of a given tissue. On a nano-scale, the walls of these capillaries have a tissue-specific structure that selectively mediates the diffusion of nutrients and proteins. To craft a histologically accurate tissue, each of these length scales must be considered and mimicked in a space-filling fashion. In this project, I sought to generate a cellular, degradable tissue scaffolds that mimicked native extracellular matrix across length scales. The research described here lays the groundwork for the generation of degradable, vascularized cell scaffolds that might be used to build architecturally complex multi-cellular tissues suitable for both pharmacological modeling and regenerative medicine.
by Micha Sam Brickman Raredon.
S.M.

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Edens, Kolbi. „Effects of Evidence-Based Materials and Access to Local Resources on Physical Activity during Pregnancy“. TopSCHOLAR®, 2019. https://digitalcommons.wku.edu/theses/3101.

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Wesso, Iona. „Science text: Facilitating access to physiology through cognition-based reading intervention“. University of the Western Cape, 1995. http://hdl.handle.net/11394/8485.

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Philosophiae Doctor - PhD
Reading and understanding science text is the principal means by which students at tertiary level access scientific information and attain scientific literacy. However, understanding and learning from science texts require cognitive processing abilities which students mayor may not have. If students fail to understand scientific text, their acquisition of subject knowledge and expertise will be impeded and they will fail to develop into thinking and independent learners, so crucial for academic progress and achievement. A major assumption in this study is thus that in order to increase access to science subjects there is a need to explicitly teach the thinking abilities involved in learning science from text. A review of the literature showed that while reading to learn from scientific text poses special challenges to students faced with this unfamiliar genre, little is known about reading (and thinking) for science learning. A synthesis of current research which describes the neglected interface between science learning, science reading and cognition is given in the literature review of this study. This synthesis highlights, in particular, the parallel developments in research into science learning and reading; the lack of integration of research in these areas; the absence of investigations on science reading located within the cognitive domain; and the absence of research into reading as it affects cognition and cognition as it affects reading in subject-specific areas such as physiology Possibilities for improving students' cognitive performance in reading to learn through intervention were considered from a cognitive perspective. From this perspective, students' observable intellectual performance can be attributed to their underlying knowledge, behaviour, and thought processes. Accordingly, the mental processes involved in comprehending scientific concepts from text and the cognitive processes which the students bring to the learning situation become highly relevant to efforts to improve cognitive skills for learning science Key questions which were identified to serve as a basis for intervention included: a) What cognitive abilities are needed for competent reading comprehension as demanded by physiology text?; b) How adequate is the cognitive repertoire of students in dealing with physiology text? With regard to these questions a catalogue of cognitive functions as formulated by Feuerstein et al (1980) was identified as optimally suited for establishing the cognitive match between reading tasks and students. Micro-analyses of the cognitive demands of students' textbook material and the cognitive make-up of second-year university students revealed a profound mismatch between students and their learning material. Students lacked both comprehension fostering and comprehension monitoring abilities appropriate to the demands of the learning task. The explication of the cognitive requirements which physiology text demands served as a basis for systematically designing instruction whereby appropriate intellectual performance for scientific comprehension from text may be attained Subsequent intervention was based on the explicit teaching of thinking abilities within the context of domain-specific (physiology) knowledge. An instructional framework was developed that integrated cognitive learning theories and instructional prescriptions to achieve an effective learning environment and improve students' cognitive abilities to employ and extend their knowledge. The objective was that the instructional model and resultant instructional methods would ensure that students learn not only the desired kinds of knowledge by conceptual change, but also the thought processes embedded and required by reading scientific material for appropriate conceptual change to take place. Micro-analysis of the cognitive processes intrinsic to understanding physiology text illuminated cognitive demands such as, for example, the ability to: transform linearly presented material into structural patterns which illuminate physiological relationships; analyse conceptually dense text rich in "paradoxical jargon"; activate and retrieve extensive amounts of topic-specific and subject-specific prior knowledge; to visualise events; and contextualise concepts by establishing an application for it. Within the above instructional setting, the study shows that the notion of explicitly teaching the cognitive processes intrinsic to physiology text is possible. By translating the cognitive processes into cognitive strategies such as assessing the situation, planning, processing, organisation, elaboration, monitoring and reflective responses, the heuristic approach effectively served to guide students through various phases of learning from text. Systematic and deliberate methods of thought that would enhance students problem-solving and thinking abilities were taught. One very successful strategy for learning from physiology text was the ability to reorganise the linearly presented information into a different text structure by means of the construction of graphic organisers. The latter allowed students to read systematically, establish relationships between concepts, identify important ideas, summarise passages, readily retrieve information from memory, go beyond the given textual information and very effectively monitor and evaluate their understanding In addition to teaching appropriate cognitive strategies as demanded by physiology text, this programme also facilitated an awareness of expository text conventions, the nature of physiological understanding, the value of active strategic involvement in constructing knowledge and the value of metacognitive awareness. Also, since the intervention was executed within the context of physiology content, the acquisition of content-specific information took place quite readily. This overcame the problem of transfer, so often experienced with "content-free" programmes. In conclusion, this study makes specific recommendations to improve science education. Inparticular, the notion of teaching the appropriate cognitive behaviour and thought processes as demanded by academic tasks such as reading to learn physiology seems to be a particularly fruitful area into which science educational research should develop and be encouraged.

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Mossor, Angela. „A Horse of a Different Color?: Material Strength and Elasticity of Bones and Tendons in Sloth Limbs“. Youngstown State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1597166028044999.

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Garrison, Elizabeth F. „Nanotoxicity of oxide-derived engineered nanomaterials : impact on cell viability and function, with conventional assays and evaluation of novel eicosanoid profiling“. Thesis, University of the Highlands and Islands, 2016. https://pure.uhi.ac.uk/portal/en/studentthesis/nanotoxicity-of-oxidederived-engineered-nanomaterials(2ac60c4a-f766-404e-81e9-77354afa20bc).html.

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Epidemiological studies highlight a direct association between the decline in respiratory health of the human population and increased environmental ultrafine particulate (UFP) exposure. This evidence, coupled with research identifying shared characteristics and toxicity between UFP and engineered nanomaterial (ENM), suggests that increased levels of ENM associated with the nanotechnology revolution could have a detrimental effect on human health. Although the link between respiratory disease and air pollution is well-established, toxicological data for ENM is limited. Current methods for the assessment of particle toxicity utilise a combination of both in vitro assays and in vivo animal testing. In some cases, these conventional assays provide unreliable results on account of nanoparticle interference. In this thesis, assays were undertaken to more fully understand the impact of a panel of ENMs on alveolar epithelial cell function and survival, as well as to assess the potential value of an alternative method for nanotoxicological screening. Eicosanoid profiling was used to assess both toxicity and inflammatory markers associated with a panel of ENMs, this technique is novel for the use in testing of ENM and the results show it has potential to be introduced/applied as an effective tool to predict a broad spectrum of detrimental effects of ENM in lung function. Submerged A549 cells, were used as a model of lung epithelial cells throughout. The secondary cell line is commonly used in in vitro research to examine the effect of toxins on respiratory health, specifically the alveolar region. A panel of ENM (SiO2, TiO2, NiO, ZnO and CuO) were selected to span from the benign to the highly toxic. ENM prepared in suspension were applied to the cells at 100cm2/mL for 24 h. This doctoral thesis focused on addressing the following aims: 1. To assess whether metallic ENM of differing chemical composition damage the cell membrane and/or mitochondria. 2. To determine whether ENM induce mitochondrial dysfunction through delivery or over-production of harmful reactive oxygen species (ROS) and, if so, to determine whether mitochondrial dysfunction results in activation of apoptosis. 3. To ascertain whether ENM alter the release of lipid inflammatory mediators using eicosanoid profiling. Mitochondrial function and membrane integrity assays revealed that CuO and ZnO induced mitochondrial dysfunction (~ 100% reduction in mitochondrial function), and promoted cell death (85 ± 7.5% cell lysis, ***P<0.001), respectively, when compared to control. In addition, superoxide production was increased by TiO2 alone (~ 100% increase, 0.0394 ± 0.0081 AU, **P<0.01), creating a discrepancy between assays. Analysis also revealed that metallic ENMs, specifically ZnO and CuO, significantly increased the production of prostaglandin E2 (~ 50%, 828 ± 119pg/sample, **P<0.01) and ~ 100%, 1439 ± 248pg/sample, ***P< 0.001), a pro-inflammatory eicosanoid, and elevated generation of a range of hydroxy-eicosatetraenoic acids (HETEs), suggesting induction of lipid peroxidation by these oxide derived ENMs. In conclusion, through the use of in vitro assays and eicosanoid analysis it was determined that ZnO and CuO ENM induce cell damage and death. However, although traditional in vitro assays are able to identify highly toxic ENM from the rest, they lack the ability to identify more subtle changes and, in some cases, are unreliable. By contrast, eicosanoid profiling has the ability to provide more detailed information regarding generation of both pro- and anti-inflammatory mediators, as well as oxidative stress, whilst avoiding the issues that are encountered through the use of current in vitro tests.

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Norton, E. R., und H. Borrego. „Evaluation of Various Materials for Harvest Preparation and Defoliation in Southeastern Arizona“. College of Agriculture, University of Arizona (Tucson, AZ), 2005. http://hdl.handle.net/10150/198172.

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A single defoliation experiment was conducted during the 2004 growing season in an effort to evaluate the effectiveness of commercially available harvest preparation materials in the higher elevation areas of southeastern Arizona. Many growers will not employ a defoliation regime but will let the crop naturally senesce with the cooler temperatures and frost. This evaluation compared a standard treatment of Ginstar with some additional tank mix ethephon based products from DuPont and BASF. These treatments were compared to the common Na chlorate treatment employed by many growers in this region of the state. Treatments included a base rate of 8 oz/acre Ginstar with three different rates of both CottonQuick and Prep. Treatments were applied on 15 October in a randomized complete block design with four replications. Data collected included observations of percent defoliation, percent regrowth control, and percent open boll on two separate dates after treatment (27 October and 4 November). Yield data was also collected at the end of the season by harvesting the center two rows of each plot. Sub samples were collected for fiber quality analysis. Results showed significant differences among treatments with respect to defoliation parameters measured. Treatments including Ginstar and higher rates of both CottonQuick and Prep performed well. The treatment consisting of Na chlorate alone was also effective. The Ginstar + CottonQuick treatment did appear to have a slight advantage in final percent open boll counts. No significant differences among treatments were detected with respect to yield and fiber quality. However, lint yield for the control treatment was lower than the other defoliation treatments. This would indicate that some type of defoliation regime does provide benefit in terms of increased yield.

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Norton, E. R., und D. L. Hatch. „2006 Evaluation of Commercial Harvest Aid Materials in Arizona Cotton Production Systems“. College of Agriculture, University of Arizona (Tucson, AZ), 2007. http://hdl.handle.net/10150/198216.

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A defoliation experiment was conducted during the 2006 growing season in an effort to evaluate the effectiveness of Ginstar® and FreeFall® defoliant alone and in combination with CottonQuik®. This study was conducted at the University of Arizona Safford Agricultural Center on Upland (cultivar DP655BR). Plots were planted on 20 April. Treatments were arranged in a randomized complete block design with four replications and treatments included Ginstar® at 6 and 8 oz./acre rates and Ginstar® at the 6 and 8 oz./acre rates in combination with various rates of CottonQuik® (1.5, 2, 3, and 4 pts/acre). We also evaluated a new product from DuPont, FreeFall® SC at different rates (3.2, 4.8, 6.4 oz./acre) in combination with CottonQuik® (2 pts./acre). The standard defoliation protocol among growers in southeastern Arizona is sodium chlorate plus Gramoxone®, so this treatment combination was also included. A control, not receiving any harvest prep material was also included for a total of fifteen treatments. Treatments were imposed on 13 October and evaluations were made on 20 October and 1 November. Estimations on percent leaf drop, regrowth control, and open boll were made. Lint yield was estimated by harvesting the center two rows of each plot and sub-samples were collected for fiber quality analysis. Plots were harvested on 2 November directly after the second evaluation date in an attempt to evaluate the boll opening effectiveness of the CottonQuik® material. Results indicated higher effectiveness of leaf drop or defoliation in the plots that included CottonQuik® as opposed to Ginstar® alone. The treatments performed much better that the standard sodium chlorate treatment. Percent leaf drop also increased at the higher rates of FreeFall® (4.8, 6.4 oz./acre). The percentage of open boll was also improved with the addition of CottonQuik® to the all of the treatments. However, very little significant differences were observed in lint yield and fiber quality. A trend of increased yield with the addition of CottonQuik® was observed when compared to Ginstar® alone or the standard sodium chlorate treatment. All aspects of harvest preparation including percent defoliation and boll opening appear to be significantly enhanced with the use of CottonQuik® when compared to standard Ginstar® rates alone.

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Huling, Kelsey Rose Stark. „Tubules to Tracebacks: Animating sensation through material“. The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555451814841903.

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Hosseini, Ghazaleh. „Computational simulation of urinary system“. Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/25855.

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The aim of the present study is to create a computational model of the ureteral system that accurately mimics its dynamic functionality. This model will be able to replicate the peristaltic movement of the ureter for a variety of physiological conditions. The objective of this research was met using our in-house fluid solid interaction model, known as coupled Cgles-Y-code in which the moving boundaries between the solid and fluid domain were replicated using a novel immersed boundary method. First, a comprehensive literature review on ureteral physiology was conducted with a focus on the anatomy of the ureter and theories behind mechanisms of ureteral peristaltic function in various physiological and pathological conditions. Next, the nonlinear tensile properties of the ureteral wall were integrated into the Y-code using the equivalent strain method and the resulting model was compared with a model with linear tensile properties. It was shown that the implementation of nonlinear tensile properties was more accurate and more closely matched the behaviour of the native ureteral wall. Next, the development of more anatomically accurate ureter model geometry was presented along with a variety of approaches to optimise the mesh resolution for this complex model. A new algorithm was then developed in order to model the Intra-Abdominal Pressure (IAP) into the Y-code. Next, two separate contraction models, constant radial and time-window-frame, were introduced. It was observed that a use of the time-window-frame contraction model coupled with the IAP algorithm exhibited a better agreement with the existing clinical data than the constant radial contraction model. Finally, a comprehensive study was conducted on the urodynamic responses when different pathological conditions are modelled. The results from using a linear tensile model, replicating an unhealthy condition, showed a high level of shear stress around the contraction lumen and a higher urine velocity in vicinity of the contraction region. In another scenario, a highly depressed amplitude of peristalsis, known to be a consequence of taking vasodilators, was simulated. It was shown that an inefficient contraction can increase the possibility of continuous reflux during the propagation of peristalsis.

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Dupont, Sophie. „Influence des conditions de développement sur le phénotype des oiseaux, de l’éclosion à l’âge adulte“. Thesis, La Rochelle, 2019. http://www.theses.fr/2019LAROS019.

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Le développement post-natal est une étape cruciale pour le reste de la vie d’un individu car c’est à ce moment que sont finalisées et maturées les fonctions physiologiques et comportementales individuelles et que la morphologie finale est acquise. Toute contrainte ou tout stress perçu par la progéniture pendant cette période peut avoir des conséquences morphologiques, physiologiques et/ou comportementales non négligeables à court mais aussi à long terme. In fine, c’est alors sa fitness qui peut être affectée par la qualité des conditions de développement subies. Ce doctorat vise à améliorer notre compréhension de l’importance des conditions environnementales abiotiques (climat, dérangement anthropique et exposition à un pesticide) et des soins parentaux rencontrés durant la croissance sur la qualité des poussins produits. Grâce à l’étude des marqueurs du stress et de l’allostasie (réponse au stress et longueur des télomères) chez des poussins d’Albatros à sourcils noirs et de Pétrel des neiges, nous avons pu démontrer, dans un premier temps, qu’à court terme, la qualité des soins parentaux – approximée par l’âge des individus reproducteurs – était un facteur très important pour la mise en place du phénotype du poussin. Dans un second temps, la manipulation des taux de corticostérone durant le développement chez des poussins de Moineau domestique (mimant une contrainte développementale) semble impacter à long terme les performances individuelles. En effet, à l’âge adulte, une réduction du métabolisme et des dépenses énergétiques, une réduction de l’attractivité sexuelle et une augmentation de l’investissement parental ont été mis en évidence. Au vu des résultats obtenus dans le cadre de ce doctorat, nous discutons de l’influence des conditions de développement sur la fitness des individus en s’appuyant sur les hypothèses évolutives détaillées dans la littérature scientifique
Post-natal development is a crucial step for the rest of life. Indeed, individual physiological and behavioral functions are set-up and matured during that life-stage and final morphology is acquired at that time. Any stress or constraint perceived by the offspring during this period can have significant morphological, physiological and/or behavioral consequences in the short but also in the long term. In fine, an individual’s fitness can be affected by the quality of its developmental conditions. This PhD aims to improve our understanding of the impact of abiotic developmental conditions (climate, human disturbance and exposure to a pesticide) and parental care on the quality of the produced chicks. Firstly, through the study of markers of stress and allostasis (stress response and telomere length) in Black-browed albatross and Snow petrel’s chicks, we demonstrated that in the short term, the quality of parental care - approximated by the age of the breeding individuals - was a major factor determining a chick’s phenotype. Secondly, the manipulation of corticosterone levels during development in House sparrow chicks (mimicking a developmental constraint) seems to have long-term impacts on individual performance. More precisely, in adulthood, I found that this experimental manipulation of developmental conditions was associated with a reduced metabolism, a reduced sexual attractiveness, and an increased parental investment during adulthood. Using the results obtained during this PhD, I discuss the influence of developmental conditions on individual fitness in an evolutionary context

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Norton, E. R., H. Borrego und R. Coleman. „Effects of Synergistic Additives to Standard Defoliation Materials in Both Upland and Pima Cotton“. College of Agriculture, University of Arizona (Tucson, AZ), 2005. http://hdl.handle.net/10150/198161.

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Two separate defoliation experiments were conducted during the 2004 growing season in an effort to evaluate the effectiveness of commercially available harvest preparation materials alone at full label rates and to also evaluate these materials at reduced rates with the addition of various synergistic chemicals designed to enhance the effectiveness of commercially available harvest prep materials. The studies were conducted at the University of Arizona Safford Agricultural Center on both Upland (cultivar DP555BR) and Pima (cultivar DP340) cotton. Plots were planted on 20 April and 27 April for the Upland and Pima, respectively. Plots were arranged in a randomized complete block design with four replications and treatments included Ginstar at recommended rates and Ginstar at reduced rates with the addition of three chemical enhancement materials (A, B, and C). Sodium chlorate was also included at a full rate and at reduced rates with the three enhancement materials. A control, not receiving any harvest prep material was also included for a total of eleven treatments. Treatments were imposed on 15 October and evaluations were made on 27 October and 4 November. Estimations on percent leaf drop, regrowth control, and open boll were made. Lint yield was estimated by harvesting the center two rows of each plot and sub-samples were collected for fiber quality analysis. Results indicated that the most effective treatment for both Upland and Pima trials was Ginstar at the full rate. Reduced rates of Ginstar in combination with the enhancement chemicals of B and C also provided good defoliation results. The chemicals that were designed to enhance the efficacy of the commercial harvest prep materials appeared to have an antagonistic affect with the sodium chlorate. Defoliation effectiveness decreased with the addition of chemicals A, B, and C to sodium chlorate. No statistical differences were detected among lint yield or any of the fiber quality parameters in any of the treatments of both the Upland and Pima trials.

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Dissertationen zum Thema „Maternal physiology“

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