In this thesis, we attempt to address some of these questions. First, we have devised a scheme to extract information of the plumes from simultaneous velocity and temperature measurements. Our method makes explicit use of the physical intuition that the velocity of the buoyant structures, e.g. plumes, should be related to the temperature fluctuation, in some apriori unknown manner as they are generated by buoyancy. Our scheme involves a decomposition of the local velocity measurement into two parts. The part that is correlated with some function of the temperature fluctuation measured at the same time is taken as the velocity of the plumes. Applying this scheme to measurements taken at the center and near the sidewall of the convection cell where the dominant buoyant structures are plumes, we have found the temperature dependence of the plume velocity at these two locations and understood our results from the equations of motion. Using these results of the temperature dependence of the plume velocity, we (i) conclude that heat is not mainly transported through the central region of the convection cell and (ii) obtain a relation between the scaling behavior of the plume velocity structure functions and the temperature structure functions that is different from what is implied by Bolgiano-Obukhov scaling. Then we have studied the possible effects of the large-scale mean circulation on the velocity and temperature statistics using simplified shell models of turbulent convection. We have introduced a large-scale mean flow into two shell models and found that its presence does not change the scaling behavior of velocity and temperature. / In turbulent thermal convection, velocity and temperature measurements taken at a point display complex fluctuations in time. On the other hand, visualization of the flow reveals recurring coherent structures. One prominent flow structure is a plume, which is generated from the thermal boundary layers by buoyancy. Another flow structure is a large-scale mean circulation that spans the entire convection cell. At least two strategies can be employed to study turbulent thermal convection or turbulent flows in general. One is to analyze and understand the fluctuations of the local measurements. The other is to characterize the coherent structures and study and understand their dynamics. These two approaches are not independent but provide complementary knowledge of the flows. Interesting questions hence include whether and how information about the ordered flow structures can be extracted from the fluctuating local measurements and how the presence of the ordered flow structures might affect the statistics of the fluctuations. / Guo, Hao = 热对流湍流中的统计特性与结构 / 郭昊. / "January 2007." / Source: Dissertation Abstracts International, Volume: 68-09, Section: B, page: 6036. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 62-66). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Title and abstract in English and Chinese. / School code: 1307. / Guo, Hao = Re dui liu tuan liu zhong de tong ji te xing yu jie gou / Guo Hao.

Among the officers sent to Tibet by the government of Republican China, fifteen were investigated in detail in this dissertation based on their significant influences on Han-Tibetan relations. I refer to them as the "special envoys on mission to Tibet". After examining the background of the envoys' mission, their activities in Tibet, their perception about Tibet and the Tibetans, and their roles in Tibetan affairs, the author argues that there was a substantial discrepancy between the information obtained by these envoys "on the spot" for their central government and the reality that was happening in Tibet. It was the strong Han nationalist historical context in which the envoys and their government perceived and dealt with Tibetan issues that resulted in a more complicated and delicate development of Han-Tibetan relationships. The historically formed inequality between the Han Chinese and non-Han minorities who scattered around the frontiers still has impacts upon contemporary China's ethic agendas. / This dissertation explores the problematic yet relatively unstudied topic of the relationship between Chinese government and Tibet during the Republican period, 1912-1949. Drawing on the abundant English and recently declassified Chinese archival materials, as well as plentiful travel records of some individuals who traveled to the Tibetan areas during that time, this dissertation firstly presents a historical narrative of officers whom the government of the Republican China sent to Tibet, and thus attempting to reconstruct an objective picture of the Republican China's relations with Tibet. / 朱麗双. / 呈交日期: 2006年10月. / 論文(哲學博士)--香港中文大學, 2007. / 參考文獻(p. 350-366)及索引. / Cheng jiao ri qi: 2006 nian 10 yue. / Source: Dissertation Abstracts International, Volume: 68-09, Section: A, page: 3907. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / School code: 1307. / Lun wen (zhe xue bo shi)--Xianggang Zhong wen da xue, 2007. / Can kao wen xian (p. 350-366) ji suo yin. / Zhu Lishuang.

Existing literature reports a puzzle about the forward foreign exchange rate premium over the spot foreign exchange rate. The premium is often negatively correlated with subsequent changes in the spot rate, which is considered to defy economic intuition and possibly violate market efficiency. Rational explanations include non-stationary risk premia and econometric misspecifications, and the puzzle as a guide to profitable trading. Actually, the puzzle consists of three aspects of anomalies: volatility, persistence, and unbiasedness. The puzzle has not yet solved fully thus far. / In the latter part of the thesis, we try to explore the behavioral aspects of the investors in the foreign currency markets (spot and forward markets). We discuss asset prices in an economy where investors derive direct utility from their consumption and adjust their utility based on the concept of habit formation and "catching up with Joneses", therefore explaining thus far the formidable unbiasedness anomaly to a certain extent. Simulation results exhibit properties similar to what has been observed in historical data. / This thesis suggests firstly that there may be no real puzzle. A simple model fits the data. Starting from examining the relations between the excess return of speculation in foreign currency forward markets and the change rates of the return rate on equity (stock) portfolio and the change rate of futures price on stock index as well as foreign currencies where the stock markets and futures market are active, publicly traded, and highly transparent markets, the source of the risk premia in the future change in spot rate has been analyzed in detail. We believe that the panel data analysis is in place for the puzzle based on its nature. In this thesis we find that the future change in spot foreign exchange rate correlate with both forward premium and especially the change rate in stock index or the change rate of futures settlement price on the stock index or on the currencies, which implies that the investors compare and employ the profitable opportunities across financial markets not just act in only one market such as just foreign exchange forward market, thus maximizing the utility or efficiency of their funds. In addition, the change rate of futures price has rather impacts on the excess return of speculation in forward currency markets, thus establishing the relation between OTC markets and publicly traded markets of foreign exchange. / Tan Yue. / "January 2007." / Adviser: Jia He. / Source: Dissertation Abstracts International, Volume: 68-09, Section: A, page: 4006. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest dissertations and theses, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

According to the literature, MRI has been applied to characterize the atherosclerosis in coronary and extracranial internal carotid artery. The cross-sections of MCA were scanned by Magnetic Resonance Imaging (MRI) to assess the accuracy of MRI in identifying MCA stenosis with histopathology as a golden standard, which was performed in the same post-mortem brains as in the second part. The sensitivity and specificity of MRI in detecting more than 30% MCA stenosis were 38.6% and 92.2%, with a positive predictive value of 87.2% and negative predictive value of 52.2%, and the corresponding values of MRI in identifying more than 50% MCA stenosis were 57.1%, 90.8%, 50% and 83.0%, respectively. Stenotic lesions >30% and >50% identified by MRI were found to be associated with infarctions in corresponding MCA territory. / After verification of potential relationship between ischemic stroke and intracranial artery calcification, the incidence of intracranial artery calcification was assessed in the ischemic stroke. One hundred and seventy-five ischemic stroke patients and 182 controls were enrolled. There was a higher prevalence of intracranial artery calcification in ischemic stroke patients than in controls. Hypertension, diabetes, smoking, intracranial artery calcification, hyperlipidemia, and atrial fibrillation were found to be independently associated with ischemic stroke. / Atherosclerotic stenosis is a heterogeneous disorder. The studies performed in extracranial carotid artery and coronary artery showed that the genes associated with lipoprotein metabolism may be associated with atherosclerosis. Thus, we speculated that the genes concerned with lipid metabolism may also be risk factors for MCA atherosclerotic stenosis. In the part of genetic analysis, clinical parameters and the genotypes of polymorphisms in the apolipoprotein E (ApoE), lipoprotein lipase (LPL), and paraoxonase (PON1) genes were compared in patients with and without MCA stenosis. Two hundred and ninety-four ischemic stroke patients were recruited, 136 cases with and 158 without MCA stenosis. Systolic blood pressure (SBP), rather than ApoE, LPL, and PON1 polymorphism was found to be a risk factor of MCA stenosis. / Calcification of intracranial artery, as a common complication of atherosclerosis, was investigated by multi-detector-row computed tomography (MDCT). By this advanced technique, the prevalence and location of calcification in intracranial arteries were determined, and its potential risk factors were also investigated. Four hundred and ninety patients were recruited. The incidence of intracranial artery calcification was 69.4%. The highest prevalence of intracranial artery calcification was seen in internal carotid artery (60%), followed by vertebral artery (20%), middle cerebral artery (5%) and basilar artery (5%). Age, a history of ischemic stroke, and white blood cell count were shown to be independently associated with intracranial artery calcification. / In the present study, genetic, pathological, imaging characterizations and prognosis of MCA stenosis were investigated. The effect of candidate genes has not been confirmed in the present study, but SBP and hypertension appears to contribute a lot to the occurrence of MCA stenosis among Chinese populations. As for the pathology of MCA atherosclerotic plaques, luminal stenosis and also the morphology of atherosclerotic plaque seem to play a cooperative role in leading to ischemic stroke. Imaging studies demonstrated the agreement between ex vivo MRI and histopathology in identifying MCA stenosis, and the correlation between the MCA stenosis identified by MRI and ischemic events. Calcification of intracranial artery, as a common complication of atherosclerosis, may be associated with age, history of ischemic stroke. High incidence of ischemic stroke has been demonstrated in Chinese type 2 diabetes patients. The presence of asymptomatic MCA stenosis plays an important role in the occurrence of ischemic stroke. / Lastly, using a cohort-study, we aimed to investigate stroke incidence of asymptomatic MCA stenosis and its risk factors in Chinese type II diabetic population. Transcranial Doppler was performed to define MCA stenosis. Incident strokes between 1996 and 2006 were ascertained by the database of Clinical Management System of the Hong Kong Hospital Authority. Anthropometric parameters (waist circumference and body mass index), blood pressure, and baseline plasma biochemical profile (lipid and glucose) were recorded to find the risk factors of ischemic stroke in asymptomatic MCA stenosis patients. Totally, 2,197 type II diabetic patients without symptoms of cerebrovascular disease were recruited. The evidence of MCA stenosis was identified in 272 subjects (12.4%), including 146 (53.7%) subjects with single-vessel involvement. Ischemic stroke occurred in one hundred and eighty-four (8.4%, 184/2197) patients. History of ischemic heart disease, MCA stenosis, the presence of retinopathy, lipid total cholesterol and age were independently associated with ischemic stroke. / Secondly, the pathological features of MCA stenosis and their relationship with cerebral infarcts were investigated in a series of post-mortem adults aged 45 years or above. The morphological features of the MCA atherosclerotic plaques were described in detail. The results demonstrated that the degree of luminal stenosis, the percentage of the plaques containing more than 40% lipid area, the values of cap-lipid, cap-lipid-stenosis, and the prevalence of intraplaque hemorrhage, neovasculature and thrombus were higher in the group of plaques associated with infarction. And the mean index of both CD45RO and CD68 were higher in the group of plaques associated with infarction. Binary logistic regression showed that stenosis, lipid area and presence of neovasculature were independent risk factors of MCA infarcts. / Stroke is one of the leading causes of death, disability, and dementia throughout the world. The stenosis of the intracranial large artery, especially the middle cerebral artery (MCA), is common in Chinese, Hispanic, and African populations. But MCA stenosis has been understudied due to its infrequency in the white population and its relative inaccessibility and invasiveness involved in its investigations. The purpose of the study was to investigate the genetic, pathological, imaging characteristics and prognosis of MCA atherosclerotic stenosis in Chinese population. / Chen Xiang-yan. / "September 2006." / Adviser: MH Ng. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1460. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 193-212). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

李林艷. / 論文(哲學博士)--香港中文大學, 2006. / 參考文獻(p. 251-269). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / Lun wen (zhe xue bo shi)--Xianggang Zhong wen da xue, 2006. / Can kao wen xian (p. 251-269). / Li Linyan.

Recurrent themes identified in the narratives of the research participants revealed their perceptions and experiences of the diverse forms of power in this setting, their understanding and interpretation of the meaning of empowerment, and the building of foundations for effective empowering practices. The research findings show how practitioners enhance their own reflexivity as well as those of service partners and users to create a favorable learning environment. They challenged the dominant discourses and produced alternative ones, thus enriching the meaning of education. They also engaged in different dimensions of empowerment, namely (1) the personal dimension as how service users recaptured a sense of competence to meet life challenges and fight for their own benefits; (2) the interpersonal dimension as how practitioners collaborated with school personnel to safeguard student rights and secure social justice; (3) the school and community dimensions as how practitioners initiated positive changes to school policies and mobilized community resources for student development; and (4) the institutional dimension as how practitioners played the advocacy role in the education sector. / The findings provide a knowledge base for an understanding of the significant aspects of power and empowerment in school social work service. The recommendations induced are put into policy, practice, and research categories. They serve as useful information for policy makers to revisit the existing school social work policy to improve the working conditions of practitioners. They give valuable reference materials for youth workers to apply the empowerment approach in actual practice. They also stimulate other intellectuals to explore future directions of social work research in general, as well as youth and school social work studies in particular. / The research findings suggest that empowerment can be generated through a number of ways and understood in terms of dialogical process, reflexive practice, discourse construction, localized actions, collective actions and multiple interventions. The synthesis of these domains opens up the possibility for developing a framework of empowerment-oriented school social work practice. This framework provides a "map" to guide practitioners to work with power in diverse, dynamic, creative, and contextual ways. / This thesis examines the field experiences of Hong Kong school social workers in encountering different forms of power and carrying out empowering practices. A critical social work perspective is adopted to theorize a conceptual framework to explicate the narratives collected through in-depth interviews with 15 frontline school social workers. These research participants were chosen with regard to their service experience, the agencies they belonged to, and the types of schools they served. Using discourse analysis as the research strategy adds a power and political dimension in analyzing their narratives in the Hong Kong context. It gives a comprehensive and detailed description of their reactions to the power relations, performances of flexible roles, generation of new discourses, and use of various strategies to initiate empowering practices. / To Su Ming. / "August 2006." / Adviser: Steven Sek-yum Ngai. / Source: Dissertation Abstracts International, Volume: 68-03, Section: A, page: 1163. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 416-452). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

With the case of Tiananmen Square in Beijing, this thesis intervenes into the contemporary discourse of "politics of space". It argues that the two theoretical perspectives provided by the contemporary spatial theorists---the structuralist approach and the phenomenological approach, have obvious inadequacy in understanding the phenomena of space in human society. For this regard, this thesis suggests to build up a political theory of space, which has its solid foundations in the spatial ideas in the classical political theories. The political perspective of space emphasizes the politics of space in the ideal-praxis processes. The perspective affirms the existence of the "autonomous sphere of political action", which is in contrary to the social theory, in which "the political" is subsumed under the macro social processes. The case of Tiananmen Square will demonstrate how space is related to human's collective action in pursuing the political and social utopia. / Lee Ka Kiu. / 論文(哲學博士)--香港中文大學, 2006. / 參考文獻(p. 232-263). / Adviser: Shu Yun Ma. / Source: Dissertation Abstracts International, Volume: 68-03, Section: A, page: 1144. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / School code: 1307. / Lun wen (zhe xue bo shi)--Xianggang Zhong wen da xue, 2006. / Can kao wen xian (p. 232-263). / Lee Ka Kiu.

張錦少. / 論文(哲學博士)--香港中文大學, 2007. / 參考文獻(p. 448-470). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / Lun wen (zhe xue bo shi)--Xianggang Zhong wen da xue, 2007. / Can kao wen xian (p. 448-470). / Zhang Jinshao.

Incorporation of heteroaromatic rings (pyridyl, pyrazinyl, pyrimidyl and thienyl) in the silver-ethynide supramolecular synthon led to a series of silver(I) double salts of various heterocyclic ethynide ligands. Through variation of the relative orientations between the ethynide moiety and heteroatom as well as between heteroatoms, different coordination networks were generated. / Synthetic and structural studies were carried out on a series of silver(I) complexes of phenylethynide and phenylethynide derivatives with alkyl substituents (methyl, tert- butyl, trifluoromethyl) at variable positions (p-, m-, o-) on the aromatic ring. The invariable appearance of the mu4- and mu5-ligation modes of the ethynide moiety in ten silver(I) complexes reaffirms the general utility of the silver-arylethynide supramolecular synthon Ar-C≡C⊃Agn( n = 4, 5) in coordination network assembly. / Systematic investigation on silver(I) tert-butylethynide complexes resulted in the establishment of the general utility of the silver-ethynide supramolecular synthon with an alkyl tail. Upon the addition of nitrile ligands from CH3CN, CH3CH2CN to (CH3) 3CCN, adjacent silver ethynide moieties tBu-C≡C⊃Ag 5 approach closer to each other, and the resulting crystal structure transforms from a 2-D hydrogen bonding network, through a 2-D network held by hydrogen bonding and coordination, to a 2-D coordination network. Employment of the multidentate dicarboxylate ligand O2CCF2CF 2CO2 and the dinitrile ligand NC(CH2)4CN led to the formation of higher-dimensional networks. / The above-mentioned structural studies of silver-ethynide complexes of aromatic or heteroaromatic ligands indicate that pi-pi stacking plays a pivotal role in the self-assembly of corresponding silver-ethynide synthons. Investigation of the silver(I) complexes of phenylethynide and its derivatives with different substituents (methyl, tert- butyl) in variable positions (o-, m-, p-) on the aromatic ring shows the relative position and the bulk of substituents both affect the pi-pi stacking between adjacent phenyl rings. Furthermore, a comparative study of pi-pi stacking in the nitrate complexes Ag2(m-C≡CC 6H4C≡C)] · 5AgNO3 · 3H 2O (38), [(3-AgC≡C)-py] · 3AgNO3 (45), 2[(2-AgC≡C)-pyraz] · 6AgNO3 3H 2O (50) and 2[2,3-(AgC≡C)2-thienyl] · 10AgNO3 (56) suggests that the pi-electron deficiency of the aromatic ring also weakens this non-covalent interaction. (Abstract shortened by UMI.) / The ensuing study of silver(I) phenylenediethynide complexes led to the recognition of another kind of supramolecular synthon, Agn⊂ C2---R---C2⊃Agn (R= p-, m-, o-C6H4; n = 4, 5). / The reaction of Li-C≡C-Ca≡C-Li (generated in situ from hexachloro-1,3-butadiene and nBuLi) with AgNO3 led to the generation of a new silver carbide, silver 1,3-butadiynediide (Ag2C4). A series of fifteen double and multiple salts of Ag2C4 were synthesized by dissolving this polymeric starting material Ag2C4 in a concentrated aqueous solution of soluble silver salts (e.g. AgNO3, AgCF 3CO2, AgC2F5CO2). The silver-ethynide interaction may be conceived as a new kind of supramolecular synthon for the construction of 1-D, 2-D and 3-D coordination polymers. The terminal silver-ethynide interactions that are assigned in diverse configurations can be conveniently classified into three types: sigma, pi and mixed (sigma,pi), and tuned by variation of ancillary anionic ligands. In addition, the controlled hydrolysis of hexafluorophosphate led to the generation of the second silver quadruple salt Ag2C4 · 4AgNO3 · AgPF 2O2 · Ag3PO4 (4). The (F)2(H2O)18 fluoride-water tape in Ag 2C4 · 2AgF · 10AgC2F5CO 2 · CH3CN · 12H2O (10) and the (C4)3 Ag18 aggregate in 3Ag 2C4 · 12AgC2F5CO2 · 5[BzMe3N)C2F5CO2] · 4H 2O (15) are both unprecedented among silver(I)complexes. / This thesis describes our effort to explore, develop and utilize the silver-ethynide interaction in new kinds of metal-ligand supramolecular synthons for the construction of silver(I) coordination networks. / Zhao, Liang. / Adviser: Thomas C. W. Mak. / Includes supplementary digital materials. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1011. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 208-228). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

All of the above findings demonstrated that eosinophil activation in allergic inflammation could be sensitively regulated by diverse stimuli. Besides, highly redundant functional effects and underlying signaling mechanisms were observed among different mediators. Elucidation of the mechanisms of eosinophil activation could improve our understanding of its complex and active role in the pathogenesis of allergic diseases, thereby providing biochemical basis for the development of more effective therapeutic strategies for treating the diseases. (Abstract shortened by UMI.) / Apart from the cytokines produced by T lymphoctyes, leptin, a cytokine produced by adipocytes, was also demonstrated to activate eosinophils. It was reported that the plasma levels of leptin were elevated in both obese and allergic patients. We found that leptin could activate eosinophils for survival enhancement, adhesion and migration, and secretion of cytokines and chemokines. Besides, we showed that the MAPKs and NF-kappaB pathways were involved in eosinophil adhesion, migration and mediator release induced by leptin, while Janus kinases (JAK)-signal transducers and activators of transcription (STAT) pathway was responsible for leptin-induced eosinophil survival. Our study indicated a potential correlation between obesity and exacerbation of allergic inflammation. / Eosinophilia is a hallmark pathological feature of allergic diseases and it has been targeted as a novel therapeutic strategy for allergic diseases. / In atopic dermatitis (AD), dermal infiltration of eosinophils is one of the pathological features of this disease. IL-31 is a novel Th2 cytokine reported to induce pruritus and skin dermatitis resembling human AD. Our study on the co-culture system of eosinophils and keratinocyte cell line HaCaT illustrated the production of pro-inflammatory cytokines and chemokines from the co-culture system of eosinophils and HaCaT cells, under the stimulation of IL-31. In co-culture system, surface expression of CD18 and intercellular adhesion molecule (ICAM)-1 on eosinophils and HaCaT cells was also up-regulated respectively, implying a direct interaction between the two cell types through their cell surface adhesion molecules. The interaction of eosinophils and HaCaT cells under IL-31 stimulation was shown to be mediated through MAPKs, NF-kappaB and PI3K pathways. These findings therefore elucidate the immunological roles of IL-31, eosinophils and keratinocytes in AD. / In the present study, we investigated the mechanisms of eosinophil activation induced by various stimuli including novel T helper type 2 (Th2) cytokines, adipokine, microbial products and direct interaction with tissue cells. The activation of eosinophils was studied in terms of survival enhancement, modulation of adhesion and migration, and the release of inflammatory mediators including cytokines, chemokines, granular proteins and superoxide. Using pharmacological and molecular approaches, we further investigated the intracellular signaling mechanisms regulating the eosinophil activation mediated by various stimuli. / Increasing evidence has indicated that bacterial and viral infections could intensify allergic responses. Our findings demonstrated that eosinophil activation could be elicited by microbes through toll-like receptors (TLRs), the recently discovered receptors for the recognition of conserved motifs in pathogens. We found that eosinophils could be activated by the ligands of TLR2, 5 and 7 in enhancing survival, adhesion and migration, release of pro-inflammatory cytokines, chemokines, granular proteins and superoxides. These stimulatory effects, mediated by TLR2, 5 and 7, were differentially regulated by MAPKs, NF-kappaB and phosphatidylinositol 3-kinase (PI3K) pathways. Moreover, an important finding of our study is the common involvement of focal adhesion kinase (FAK)-dependent extracellular-regulated protein kinase (ERK) phosphorylation in the signaling of TLR 2, 5 and 7, implying a special role of FAK in linking TLR signaling with MAPKs cascade in human eosinophils. Our study on microbe-induced eosinophil activation provided a potential explanation for linking infection with exacerbation of allergic diseases. / The interleukin (IL)-17 family is a newly discovered group of cytokines which was reported to be important in allergic inflammation. We studied the roles of two IL-17 family members, IL-175E/IL-25 and IL-17F on eosinophil activation. Both cytokines were found to induce the secretion of inflammatory cytokines and chemokines from eosinophils, in which IL-25 could also enhance eosinophil survival and adhesion. Besides, we found that the stimulatory effects induced by both IL-25 and IL-17F were mediated through mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-kappaB) pathways. The main source of IL-17F has recently been reported to be a novel T lymphocyte population, Th17, which is specifically driven by IL-23. An important finding of our present study was the synergistic effects of IL-17F and its potent inducer, IL-23, on cytokine release from eosinophils. Since IL-23 was produced by macrophages and dendritic cells upon microbial stimulation, the synergistic effect of IL-17F and IL-23 on eosinophil activation might imply a potential role in linking microbial infection and allergic inflammation. Our findings also provide further support to the crucial role of the IL-17 family and Th17 lymphocytes in the amplification of allergic diseases. / Cheung, Fung Yi. / Source: Dissertation Abstracts International, Volume: 69-03, Section: B, page: 1552. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 205-221). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.