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GHRH/PACAP-GH-IGF axis in the ovary of zebrafish, Danio rerio. / CUHK electronic theses & dissertations collectionJanuary 2012 (has links)
生長和繁殖這兩個最主要的生理過程在脊椎動物中是密切相關的。生長主要是由腦-垂體-肝軸,即促生長激素釋放激素/垂體腺苷酸環化酶激活肽(GHRH/ PACAP-生長激素(GH)-胰島素樣生長因子(IGFs)軸所控制。值得一提的是,所有與這個神經內分泌軸相關的基因在卵巢中都有表達。這表明一個有功能的微型軸很可能存在於卵巢中。我們著重研究PACAP,該軸的上游因子,來揭示卵巢中這個微型軸的存在和功能。 / PACAP是一種最初從羊的下丘腦純化出來的夠能刺激cAMP分泌的神經肽,研究表明它也存在於如卵巢在內的其它各種外圍組織中。在斑馬魚中,兩種形式的PACAP(PACAP38-1,adcyap1a; PACAP38-2,adcyap1b)和三個 PACAP受體(PAC1-R,adcyap1r1; VPAC1-R,vipr1和VPAC2-R,vipr2)均在卵巢中表達。為了確定PACAP系統在斑馬魚的卵巢中有重要作用,我們首先對 PACAP的配體和三個受體在濾泡中的空間分佈進行了研究。此外,為了研究PACAP系統的潛在作用,我們還分析了PACAP的配體和受體在濾泡發育和成熟時期的表達情況。PACAP系統在濾泡細胞中時空表達的數據顯示,PACAP可能在調節濾泡發育和成熟中發揮雙重作用,這雙重作用是通過PACAP作用於不同的受體上完成的。卵母細胞體外成熟實驗的結果顯示PACAP可以促進完整的濾泡卵母細胞的成熟,但抑制裸露的卵母細胞體外自發成熟,這也進一步支持了我們的假說。 / 我們以前的研究表明,在原代培養的斑馬魚濾泡細胞中,垂體促性腺激素(HCG)可以顯著提高PACAP(PACAP38-2)的表達。因此,PACAP很可能是垂體促性腺激素控制卵巢功能的下游調節者。我們從幾個方面來驗證我們的假設。首先,由於激活素/結合蛋白系統是公認的垂體促性腺激素(HCG)的下游調節者,我們研究了PACAP對該系統表達的調控。研究結果表明,PACAP不僅能模仿促性腺激素對激活素/結合蛋白系統表達的調控,同時也刺激激活素介導的卵母細胞的成熟。PACAP和hCG選擇同樣的信號通路對激活素/結合蛋白系統進行調控進一步證實 PACAP的下游調節作用。其次,卵巢內源性生長因子,表皮生長因子EGF對PACAP調控激活素/結合蛋白系統表達的影響和其對hCG調控該系統表達的影響是一樣的。表皮生長因子可以作用於其膜上的受體並且使用MEK途徑來調節PACAP對激活素/結合蛋白系統的表達的調控。第三,我們研究了PACAP對激素生成的影響。芳香化酶是激素生成中一個十分重要的酶,它可以將睾酮轉化成雌激素E2。PACAP能刺激斑馬魚濾泡細胞中芳香化酶的表達。cAMP類似物,如forskolin和dbCAMP都可以模仿PACAP對芳香化酶的表達。PKA抑製劑 H89,可以完全抑制 PACAP誘導的芳香化酶的表達,這表明PACAP通過cAMP-PKA依賴性途徑調節芳香化酶的表達。由於促性腺激素也使用相同的cAMP-PKA途徑調節芳香化酶的表達,這進一步證實了PACAP是促性腺激素的下游調節者。 / 我們還研究了PACAP對該軸的其他因子調控,以便確定卵巢中是否存在一個有功能的GHRH/PACAP-GH-IGF軸。我們使用斑馬魚原代培養的濾泡細胞作為研究體系進行了一系列的基因調控的研究。PACA可以刺激gh及其受體 ghra和ghrb的表達。此外,它還增加了igf1表達,但對igf2a和igf2b的表達沒有明顯的影響。鑑於之前的工作證明重組zfGH可以刺激igf1的表達,我們有理由相信,在斑馬魚卵巢中存在一個有功能的GHRH/PACAP-GH-IGF軸。PACAP對此軸的調節作用也主要是通過cAMP-PKA途徑。 / 本研究不僅增加了我們對GHRH/PACAP-GH-IGF軸在卵巢中功能的了解,而且還提供了關於魚類生長和繁殖的協調方面有價值的信息,這必將有利於水產養殖。魚脊椎動物中最原始,最多元化的群體,目前的研究結果為其他生物的研究也提供了重要的參考。 / Growth and reproduction are two major physiological processes, which have been proven to be closely related in vertebrates. The process of growth is governed by the brain-pituitary-liver axis involving growth hormone releasing hormone/ pituitary adenylate cyclase-activating polypeptide (GHRH/PACAP), growth hormone (GH) and insulin-like growth factors (IGFs). Interestingly, the expression of all the genes involved in this axis has been reported in the ovary, which indicates that a functional mini-axis might exist in the ovary. In this study, we focus on the characterization of PACAP, the upstream element of the axis, to reveal the existence and functional roles of this intraovarian mini-axis. / PACAP is a neuropeptide originally purified from ovine hypothalamus for its potent activity to stimulate cAMP production. However, its presence and actions have also been demonstrated in various peripheral tissues including the ovary. In the zebrafish, two forms of PACAP (PACAP₃₈-1, adcyap1a; and PACAP₃₈-2, adcyap1b) and three PACAP receptors (PAC1-R, adcyap1r1; VPAC1-R, vipr1 and VPAC2-R, vipr2) were all expressed in the ovary. To provide clues to the importance of the PACAP system in the function of zebrafish ovary, we first investigated the spatial distribution of both PACAP ligands and the three potential receptors in the somatic follicle layer and denuded oocytes. We also analyzed the temporal expression profiles of PACAP ligands and receptors during follicle growth and maturation. Spatiotemporal expression data of PACAP system suggested that PACAP might play dual roles in regulating follicle growth and maturation through different receptors located in different compartments. This hypothesis was further supported by the observation that PACAP promoted maturation of follicle-enclosed oocytes but suppressed spontaneous maturation of denuded oocytes in vitro. / As the expression of PACAP (PACAP₃₈-2) was significantly stimulated by pituitary gonadotropins (hCG) in cultured zebrafish follicle cells, PACAP is therefore likely a downstream mediator or modulator of pituitary gonadotropins in controlling ovarian functions. We illustrated from several aspects to verify our hypothesis. Firstly, we tested the regulation of PACAP on the expression of activin/follistatin system for its well characterized roles in mediating pituitary gonadotropins (hCG). According to our results, PACAP could not only mimic gonadotropin-regulated expression of the activin/follistatin system, but also stimulated activin-mediated oocyte maturation. The same cAMP-dependent signal pathways PACAP and hCG chose towards the differential regulation of activin/follistatin system further confirm PACAP’s role as a mediator or even an amplifier. Secondly, EGF, the ovary-derived growth factor, was administrated to study its effects on PACAP regulated expression of activin/follistatin system. Similar with its influences on hCG regulated genes expression of activin system, EGF could work on its membrane receptors using a MEK pathway to regulate the effects of PACAP. Thirdly, the effect of PACAP on steroidogenesis was also studied. PACAP could stimulate the expression of aromatase, one of the steroidogenic enzymes that could convert testosterone to E2, in cultured zebrafish follicle cells. Its effect on aromatase expression could be mimicked by drugs that increase intracellular cAMP levels such as forskolin and db-cAMP. PACAP induced aromatase expression was totally abolished by a PKA inhibitor H89, which indicated that PACAP worked through a cAMP-PKA dependent pathway to regulate aromatase expression. As gonadotropins also use the same cAMP-PKA pathway to regulate the expression of aromatase, it was further confirmed that PACAP could mediate or amplify the effects of gonadotropins, even in steroidogenesis. / We also studied the regulatory effects of PACAP on other components of this mini-axis to find out whether this hypothetical GHRH/PACAP-GH-IGF axis in the ovary work the same way as the systemic somatotrophic one. We carried out a series of regulatory studies using the primary zebrafish follicle cell culture system. Interestingly, PACAP up-regulated the expression of gh and its receptors ghra and ghrb. In addition, it also increased the expression of igf1 but not igf2a and igf2b. Accompanied with the fact that recombinant zfGH could stimulate the expression of igf1, we have reason to believe that a functional intraovarian axis exited in zebrafish ovary. It seems that the regulatory effects of PACAP on this axis also mediated through a cAMP-PKA pathway. / The present study not only increases our understanding of the GHRH/PACAP- GH-IGFs axis and its actions in the ovary, but also provides valuable information on the coordination of growth and reproduction in fish, which will surely benefit the manipulation of fish growth and breeding in aquaculture. Since fish represent the most primitive and diverse group of vertebrates, the information obtained from the present study will serve as important reference for the studies in other organisms. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhou, Rui. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 127-157). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract in English --- p.i / Abstract in Chinese --- p.iv / Acknowledgement --- p.vi / Table of content --- p.viii / List of figures and tables --- p.xiii / Symbols and abbreviation --- p.xvi / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Ovary --- p.1 / Chapter 1.1.1 --- Folliculogenesis --- p.1 / Chapter 1.1.2 --- Steroidogenesis --- p.7 / Chapter 1.1.3 --- Endocrine, paracrine and autocrine network of ovarian follicles --- p.8 / Chapter 1.2 --- GHRH/PACAP-GH-IGF axis --- p.11 / Chapter 1.2.1 --- GHRH/PACAP-GH-IGF axis in growth --- p.11 / Chapter 1.2.2 --- GHRH/PACAP-GH-IGF axis in reproduction --- p.13 / Chapter 1.3 --- Pituitary adenylate cyclase-activating polypeptide (PACAP) family --- p.15 / Chapter 1.3.1 --- PACAP ligands --- p.15 / Chapter 1.3.2 --- PACAP receptors --- p.17 / Chapter 1.3.3 --- Function of PACAP system --- p.21 / Chapter 1.4 --- Objective of present study --- p.23 / Chapter Chapter 2 --- Pituitary Adenylate Cyclase-activating Polypeptide (PACAP) and Its Receptors in the Zebrafish Ovary - Evidence for Potential Dual Roles of PACAP in Controlling Final Oocyte Maturation / Chapter 2.1 --- Introduction --- p.27 / Chapter 2.2 --- Materials and method --- p.30 / Chapter 2.2.1 --- Animals and chemicals --- p.30 / Chapter 2.2.2 --- Isolation of ovarian follicles --- p.31 / Chapter 2.2.3 --- Separation of oocyte and follicle layer --- p.32 / Chapter 2.2.4 --- Follicle incubation and oocyte maturation assay --- p.32 / Chapter 2.2.5 --- Primary follicle cell culture --- p.33 / Chapter 2.2.6 --- RNA extraction and reverse transcription --- p.33 / Chapter 2.2.7 --- Semi- quantitative RT-PCR and real-time qPCR --- p.33 / Chapter 2.2.8 --- Data analysis --- p.34 / Chapter 2.3 --- Results --- p.34 / Chapter 2.3.1 --- Spatial distribution of PACAP system within the follicle --- p.34 / Chapter 2.3.2 --- Temporal expression profiles of the PACAP system during folliculogenesis --- p.35 / Chapter 2.3.3 --- Expression profiles of PACAP system in peri-ovulatory period in vivo --- p.35 / Chapter 2.3.4 --- Expression mark change of the PACAP system during in vivo and in vitro maturation --- p.37 / Chapter 2.3.5 --- Effects of PACAP on final maturation of intact follicles and denuded oocytes --- p.38 / Chapter 2.4 --- Discussion --- p.39 / Chapter Chapter 3 --- PACAP Mimics Pituitary Gonadotropin(s) in Regulating Ovarian Activin/Inhibin/Follistatin System / Chapter 3.1 --- Introduction --- p.54 / Chapter 3.2 --- Materials and method --- p.57 / Chapter 3.2.1 --- Animals and chemicals --- p.57 / Chapter 3.2.2 --- Primary culture of ovarian follicle cells --- p.57 / Chapter 3.2.3 --- Total RNA isolation and reverse transcription --- p.58 / Chapter 3.2.4 --- Real-time polymerase chain reaction --- p.58 / Chapter 3.2.5 --- Isolation and incubation of follicles --- p.59 / Chapter 3.2.6 --- Data analysis --- p.59 / Chapter 3.3 --- Result --- p.61 / Chapter 3.3.1 --- PACAP regulation of the expression of activin/inhibin/follistatin system in cultured zebrafish ovarian follicle cells --- p.61 / Chapter 3.3.2 --- Involvement of protein kinase A (PKA) in the differential regulation of activin subunits and follistatin by PACAP --- p.61 / Chapter 3.3.3 --- Potential role of activin in PACAP-induced oocyte maturation --- p.62 / Chapter 3.3.4 --- Interactive effects of EGF and PACAP on the expression of activin subunits and follistatin in the follicle cells --- p.62 / Chapter 3.3.5 --- Potential involvement of EGF-EGFR signaling in PACAP-regulated expression of activin subunits and follistatin in the follicle cells --- p.62 / Chapter 3.4 --- Discussion --- p.63 / Chapter Chapter 4 --- PACAP Regulation of Ovarian GH-IGF System / Chapter 4.1 --- Introduction --- p.78 / Chapter 4.2 --- Materials and methods --- p.81 / Chapter 4.2.1 --- Animals and chemicals --- p.81 / Chapter 4.2.2 --- Primary culture of ovarian follicle cells --- p.81 / Chapter 4.2.3 --- Total RNA isolation and reverse transcription --- p.82 / Chapter 4.2.4 --- Real-time polymerase chain reaction --- p.82 / Chapter 4.2.5 --- Follicle incubation --- p.82 / Chapter 4.2.6 --- Data analysis --- p.83 / Chapter 4.3 --- Result --- p.83 / Chapter 4.3.1 --- PACAP regulation of the expression of growth hormone and growth hormone receptors in cultured zebrafish ovarian follicle cells --- p.83 / Chapter 4.3.2 --- PACAP regulation of the expression of insulin-like growth factors and their receptors in cultured zebrafish ovarian follicle cells --- p.84 / Chapter 4.3.3 --- Self-regulation of PACAP expression in cultured zebrafish ovarian follicle cells --- p.85 / Chapter 4.3.4 --- Evaluation of protein kinase A (PKA) involvement in the PACAP-regulated expression of GH and IGFs family --- p.85 / Chapter 4.3.5 --- Interactive effects of PACAP and EGF on expression of zebrafish GH-IGF axis in cultured follicle cells --- p.86 / Chapter 4.4 --- Discussion --- p.87 / Chapter Chapter 5 --- PACAP regulation of cytochrome P450 aromatase expression in cultured zebrafish ovarian follicle cells / Chapter 5.1 --- Introduction --- p.103 / Chapter 5.2 --- Materials and methods --- p.106 / Chapter 5.2.1 --- Animals and chemicals --- p.106 / Chapter 5.2.2 --- Primary culture of ovarian follicle cells --- p.106 / Chapter 5.2.3 --- Total RNA isolation and reverse transcription --- p.107 / Chapter 5.2.4 --- Real-time polymerase chain reaction --- p.107 / Chapter 5.2.5 --- Data analysis --- p.108 / Chapter 5.3 --- Results --- p.108 / Chapter 5.3.1 --- PACAP regulation of cyp19a1a expression in cultured zebrafish ovarian follicle cells --- p.108 / Chapter 5.3.2 --- Effects of forskolin and db-cAMP on cyp19a1a expression --- p.109 / Chapter 5.3.3 --- Involvement of protein kinase A (PKA) in the regulation of cyp19a1a expression by PACAP --- p.109 / Chapter 5.4 --- Discussion --- p.109 / Chapter Chapter 6 --- General Discussion / Chapter 6.1 --- Potential roles of PACAP in folliculogenesis --- p.120 / Chapter 6.2 --- PACAP mediates gonadotropins’ signaling through activin/follistatin system --- p.123 / Chapter 6.3 --- PACAP regulation of steroidogenesis --- p.124 / Chapter 6.4 --- PACAP regulation of ovarian PACAP-GH-IGF axis --- p.127 / Reference
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Is English language causing a dichotomy between economic growth and inclusive growth in India?Bedi, Jaskiran Kaur January 2018 (has links)
India's colonial legacy and linguistic diversity has given English language a prominent role in the country. This research, through a historical analysis, first understands the factors behind the persistent prevalence of the language in India. The reasons go beyond colonial legacy and globalisation, and enters the domain of economics. Particularly, India’s reliance on the service sector plays a role in accrediting the language with a superior status. Having entered the economic arena, the research, using India Human Development Survey Round 2, conceptualises and quantifies the impact of English language on economic indicators including wage rates and GDP. The results reflect a significantly positive relationship between the language and income. A fluent English speaker earns 34 percent more than a non-English speaker. Furthermore, the empirical results highlight that the response of growth to investment in a state is greater the higher the number of English speakers. The substantiation of the importance of language’s perpetuation from service-based growth is further embedded by the fact that there exists a positive and statistically significant relationship between the number of fluent English speakers in a state and the growth rate of the Gross State Domestic Product of services. The thesis further investigates the relationship between the language and the inclusivity of growth. The results highlight that the likelihood of fluent English speakers moving out of the ‘deprived’ income strata by earning INR 1.5 lakh or more annually is 33 percentage points higher than that of non-English speakers. The research thus, empirically proves that though English is helping economic growth, it is simultaneously hindering development in terms of inclusivity, hence paving way for a dichotomy that policy makers need to resolve. Finally, the research aims to suggest a solution to the dichotomy through an analysis of the education system in India. Particularly, using primary data collection in Delhi, Chandigarh and Shimla, the research evaluates the pedagogy of English Language, and its impact on the learning levels. It highlights that the pedagogy of the language within the CBSE framework requires editions to lead to an inclusive learning of the language.
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Essays on Trade and GrowthHou, Yulin 06 June 2018 (has links)
This dissertation is composed of three essays on international trade and economic growth. The first essay investigates whether the content of what economies export matters for human capital accumulation. I construct a small open economy model and find that expansion of primary exports can harm human capital accumulation if the economy is initially allocating significant resources to primary goods production. Then I test this prediction empirically using Latin American data over the period from 1965 to 2010 and find robust evidence in support of the hypothesis that a shift towards primary exports reduces human capital accumulation.
In the second essay, I investigate the effects of gravity variables (distance, common border, colony relationship, free trade agreement, or language) on preference and trade costs. This essay models the imports of the U.S. at the individual good level and uses the three-stage least square regression approach by focusing on the trade elasticities. Using actual data on trade costs, this essay decomposes the overall effects of gravity variables on trade into those through gravity channels: duties/tariffs, transportation costs, and dyadic-preference. The results imply that gravity variables mainly capture the effect of preference rather than trade costs (as implied by the existing literature).
In the final essay, I examine the effects of increased demand from China on economic growth of the Latin American and the Caribbean (LAC) countries. This essay views the increased Chinese demand in the early 2000s as a quasi-natural experiment and considers it as a “treatment” to which a part of the LAC region was subjected. I adopt a difference-in-difference framework and find that China's demand did deliver significantly higher growth rates to LAC exporters over the last decade and a half.
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Mechanims of lactose crystallisationDincer, Tuna January 2000 (has links)
Lactose is the major carbohydrate in milk. The presence of lactose in whey constitutes a significant pollution problem for dairy factories. At the same time, there is an increasing market for high quality crystalline lactose. The main problem of lactose crystallisation, compared to sucrose, which is also a disaccharide, is that it is very slow, unpredictable and cannot easily be controlled. Compared to sucrose crystallisation, which has been extensively studied, lactose crystallisation lacks the fundamental research to identify the mechanisms of growth and effect of additives. An important difference from most other crystal growth systems is that ([alpha]-lactose hydrate crystals never grow from a pure environment; their growth environment always contains beta lactose. [alpha]-lactose monohydrate crystallises much more slowly because of the presence of [beta]- lactose in all solutions. Although there have been some studies on growth rates and the effect of additives, there has not been any reported work on the fundamentals of lactose crystallisation and the mechanisms that operate on the molecular level. The aim of this thesis is to gain a greater understanding at the fundamental processes, which occur at the molecular level during the crystallisation of lactose, in order to improve control at a macroscopic level. / The growth rates of the dominant crystallographic faces have been measured in situ, at three temperatures and over a wide range of supersaturation. The mean growth rates of faces were proportional to the power of between 2.5-3.1 of the relative supersaturation. The rate constants and the activation energies were calculated for four faces. The [alpha]-lactose monohydrate crystals grown in aqueous solutions exhibited growth rate dispersion. Crystals of similar size displayed almost 10 fold difference in the growth rate grown under identical conditions for all the faces. Growth rate dispersion increases with increasing growth rate and supersaturation for all the faces. The variance in the GRD for the (0 10) face is twice the variance of the GRD of the (110) and (100) faces and ten times higher than the (0 11) face at different supersaturations and temperatures. The influence of [beta]-lactose on the morphology of [alpha]-lactose monohydrate crystals has been investigated by crystallising [alpha]-lactose monohydrate from supersaturated DMSO ethanol solutions. The slowness of mutarotation in DMSO allowed preparation of saturated solutions with a fixed, chosen [beta]-lactose content. It was found that [beta]-lactose significantly influences the morphology of [alpha]- lactose monohydrate crystals grown from DMSO solution. At low concentrations of [beta]-lactose, the fastest growing face is the (011) face resulting in long thin prismatic crystals. At higher [beta]-lactose concentrations, the main growth occurs in the b direction and the (020) face becomes the fastest growing face (since the (011) face is blocked by [beta]-lactose), producing pyramid and tomahawk shaped crystals. / Molecular modeling was used to calculate morphologies of lactose crystals, thereby defining the surface energies of specific faces, and to calculate the energies of interactions between these faces and [beta]-lactose molecules. It was found that as the replacement energy of [beta]-lactose increased, the likelihood of [beta]-lactose to dock onto faces decreased and therefore the growth rate increased. The attachment energy of a new layer of [alpha]-lactose monohydrate to the faces containing [beta]-lactose was calculated for the (010) and (011) faces. For the (0 10) face, the attachment energy of a new layer was found to be lower than the attachment energy onto a pure lactose surface, meaning slower growth rates when [beta]-lactose was incorporated into the surface. For the (011) face, attachment energy calculations failed to predict the slower growth rates of this face in the presence of [beta]-lactose. AFM investigation of [alpha]-lactose monohydrate crystals produced very useful information about the surface characteristics of the different faces of the [alpha]-lactose monohydrate crystal. The growth of the (010) face of the crystal occurs by the lateral addition of growth layers. Steps are 2 nm high (unit cell height in the b direction) and emanate from double spirals, which usually occurred at the centre of the face. Double spirals rotate clockwise on the (010) face, while the direction of spirals is counterclockwise on the (010) face. A polygonised double spiral, showing anisotropy in the velocity of stepswas observed at the centre of the prism-shaped a-lactose monohydrate crystals grown in the presence of 5 and 10 % [beta]-lactose. / The mean spacing of the steps parallel to the (011) face is larger than those parallel to the (100) face, indicating higher growth rates of the (011 )face. The edge free energy of the (011) face is 6.6 times larger than the (100) face in the presence of 5% [beta]-lactose. Increase of [beta]-lactose content from 5% to 10 % decreases the edge free energy of the growth unit on a step parallel to the (011) face by 10 %. Tomahawk-shaped [alpha]-lactose monohydrate crystals produced from aqueous solutions where the [beta]-lactose content of the growth solution is about 60 % have shown clockwise double spirals as the source of unit cell high steps on the (010) face of the crystal. However , the spirals are more circular than polygonised, unlike the prism shaped crystals and the mean step spacing of the (011) face is less than the steps parallel to the (110) face, indicating the growth rate reducing effect of [beta]-lactose on the (011) face. The (100) face of the [alpha]-lactose monohydrate crystal grows by step advancement in relative supersaturations of up to 3.1. Steps are 0.8 nm high and parallel to the c rection. Above this supersaturation, rectangular shaped two-dimensional nuclei, 10 nm high, were observed. The (011) face of the crystal grown at low supersaturations (s= 2.1) displayed a very rough surface with no steps, covered by 4-10nm high and 100-200[micro]m wide formations. Triangular shaped macrosteps were observed when the crystal was grown in solutions with s=3.1. In situ AFM investigation of the (010) face (T = 20[degree]C and s = 1.18) has shown that growth occurs by lateral addition of growth units into steps emanated by double spirals. / The growth rate of the (010) face from in situ AFM growth experiments was calculated to be 1.25 gm/min. The growth rate of crystals grown in the in situ optical growth cell under identical conditions was 0.69 pm/min. The difference in growth rates can be attributed to the size difference of seed c stals used. The (010) face of a [alpha]-lactosemonohydrate crystal grown at 22.4 C and s=1.31 displayed triangular-shaped growth fronts parallel to the (011) face. The steps parallel to the (O11) face grow in a triangular shape, and spaces between triangles are filled by growth units until the end of the macrosteps is reached. No such formations were observed on steps parallel to the (110) face. Formation of macrosteps, 4-6 nm high, emanating from another spiral present on the surface was also observed on the (010) face of a crystal grown under these conditions.
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An investigation of leg pain ('Growing pains') in children aged four to six yearsEvans, Angela M January 2005 (has links)
Growing pains has been reported in the medical literature since 1823 with frequent, subsequent and ongoing inclusion ever since. Suffering from ill definition, unknown aetiology and being the subject of many poorly conducted studies, growing pains has endured the gamut of being associated with endocarditis to being dismissed as nebulous and even mythical. Management of this condition, which has been reported to occupy 1-2 % of visits to health professionals, is ad hoc and limited and best evidence not usually implemented. / Thesis (PhD)--University of South Australia, 2005
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Maternal overnutrition and the regulation of energy balance and appetite before and after birthMuhlhausler, Beverly Sara January 2006 (has links)
Based on a large series of epidemiological studies, it has been proposed that exposure to an increased nutrient supply before birth increases the risk of developing obesity in postnatal life. The physiological mechanisms underlying the association between increased nutrition before birth and later obesity are, however, poorly understood. This thesis has investigated the impact of an increased fetal nutrient supply on the programming of key systems within the appetite - regulating network and / or the adipocytes before and after birth. The studies in this thesis have demonstrated that plasma concentrations of the adipostatic hormone leptin are directly related to adiposity and the size of adipose cells in fetuses of ewes fed at or above maintenance energy requirements, which suggests that leptin may act as a peripheral signal of fat mass before birth. It has also been demonstrated that the components of the central network for appetite regulation are expressed in the hypothalamus of the fetal sheep from at least 110 d gestation ( term = 150 ± 3 d gestation ), and that the expression of the appetite - regulating neuropeptides is responsive to signals of increased nutrient supply before birth. This thesis has also demonstrated that an increase in maternal nutrition in late pregnancy results in increases in both food intake and glucose concentrations in the lamb in early postnatal life and in a significant increase in subcutaneous adiposity on postnatal day 30. Importantly, increased maternal nutrition resulted in an altered relationship between signals of increased fat mass and nutrition and expression of a central appetiteinhibitory neuropeptide, CART, in the lamb hypothalamus. It was also demonstrated that there was an interaction between the prenatal and postnatal nutritional environments in the determination of lipogenesis in the early postnatal period. The findings presented in this thesis provide evidence that programmed changes to the sensitivity of the appetite - regulating neuropeptides to signals of increased adiposity and nutritional status in early postnatal life are an important part of the physiological pathway through which exposure to an increased nutrient supply before birth may lead to an increased risk of obesity in later life. / Thesis (Ph.D.)--School of Molecular and Biomedical Science, 2006.
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Effective strategies for healthy church growth in the Hap Dong Jung Tong Presbyterian denomination in KoreaHan, Manoh. January 2007 (has links)
Thesis (D.Min.)--Liberty Theological Seminary and Graduate School, 2007.
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Growth characteristics and site potentials of perennial grass speciesBorman, Michael M. 13 June 1989 (has links)
In this study I assessed the potentials of selected,
established perennial grasses to maintain site occupancy in
the foothills ecosystem of the Rogue River Valley of
southwest Oregon which is currently dominated by a variety
of annual plants.
The first evaluation compared growth curves of the
perennial grasses and contrasted them to growth patterns of
residual annual plants. Periods of growth varied among the
perennial grasses studied. Of the perennial grasses, Idaho
fescue (Festuca idahoensis), a native, and Berber
orchardgrass (Dactylis glomerata var. 'Berber'),
introduced, most closely emulated the growth patterns of
the majority of the annual plants. Relative to the other
perenial grasses tested, they initiated growth earlier,
continued some growth through the winter and matured
earlier. Once established, they should be able to
effectively compete with the resident annuals for resources
and maintain their populatiOhs.
To assess the potential for competition for available
moisture, the second evaluation considered timing and
extent of soil moisture extraction by the perennial grasses
and the resident annual community through the periods of
active growth. This verified growth analysis results.
Idaho fescue and Berber orchardgrass extracted moisture
earlier than the other perennial grasses. Perennial grass
plots and plots dominated by yellow starthistle (Centaurea
solstitialis) end of season residual soil moisture levels
were similar. Resident annual grasses left considerably
more soil moisture. In years with an early summer drought,
the earlier growing perennial grasses should be able to
satisfy growth requirements and persist.
An assessment was also made of the abilities of
several selected established perennial grasses to resist
reinvasion by resident annual plants. Earlier growing
perennial grasses such as Berber orchardgrass and Idaho
fescue suppressed the annuals more effectively than the
later growing perennial grasses.
Of the perennial grasses studied, those emulating the
growth patterns of the annuals have been the Most
competitive and have maintained the most vigorous stands. / Graduation date: 1990
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A Natural Resource Curse: Does it Exist Within the United States?Gerard, Bryce 01 January 2011 (has links)
In this paper, we examine data on U.S. GDP/Capita and natural resource share of GDP by state. We then run growth regressions and build on a previous model of dynamic equations to account for the spatial equilibrium that exists between U.S. states. Our results show that there exists evidence that overinvestment in oil and mining sectors has negative effects on state TFP growth, thus giving positive evidence for the existence of a natural resource curse between U.S. states.
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The functional crosstalk between MT1-MMP and ADAMs in craniofacial & vascular developmentWong, Hoi-leong, Xavier, 王凱亮 January 2013 (has links)
abstract / Biochemistry / Doctoral / Doctor of Philosophy
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