Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Every year 33,000 women die of cervical cancer in Latin American and the Caribbean. Cervical cancer has been the leading cause of potential years of life lost in Chile. Identifying factors that increase Pap test adherence will be extremely useful for developing interventions to increase the use of the Pap test and to reduce the prevalence of cervical cancer. The purpose of this study was to develop and validate a questionnaire to examine women's beliefs about cervical cancer and the Pap test in Chilean women. The questionnaire, developed following the guidelines by Robert de Vellis, is based on the Health Belief Model. The content validity index was 0.93 after 10 Chilean expert's review. A cross-sectional design was implemented to validate the questionnaire. The sample included 333 women recruited from a women's health care center in Santiago, Chile. Exploratory factor analysis was used to evaluate validity and coefficient alpha to evaluate reliability. After six models were computed, the questionnaire was reduced from 53 to 28 items. The new questionnaire,"CPC-28" includes six domains: the barriers domain to take a Pap test considers problems related with a health care center, lack of knowledge and time, being afraid, and embarrassment; the cues to action domain considers cues from family, the health care professional, friend and media; the severity domain considers cervical cancer as a serious problem, the possibility to have a hysterectomy, radiation and chemotherapy, and to die from this disease; the susceptibility domain to take a Pap test considers symptoms, having children, and intercourse; the susceptibility to cervical cancer domain considers the risk to have the disease, age, and possibility to die; and the benefit domain includes to save a life, feel good, and to take care of health. An unexpected salient factor "need to have a Pap test" was found as part of the susceptibility domain. This finding is an important topic for future research. The CPC-28 questionnaire explained 49% of the total variance, and the reliability was .735. It was concluded that the CPC-28 questionnaire will have important implications on research, educative, and administrative role of nursing.

Thesis (M.P.H.)--University of Hong Kong, 2006.

Yin Yang 1 (YY1) is a multifunctional transcription factor that is known mainly for its ability to activate or initiate transcription of a wide assortment of genes involved in cellular growth and differentiation. <i>Xenopus laevis </i>oocytes and embryos were used as a model to identify and characterize a potential developmental role for YY1. Northern and Western blots of oocyte and embryonic extracts showed YY1 mRNA and protein is expressed from the earliest stages of oocyte development through to tadpole stages. Examination of the transcriptional activity of YY1 in both oocytes and embryos using reporter gene constructs containing YY1-binding elements demonstrated that YY1 does not act as a repressor or activator of transcription either in oocytes or in embryos. Sub-cellular fractionation of oocytes and Western blot analysis showed YY1 is localized almost exclusively to the cytoplasm of oocytes and in cells of early embryos. Sequence analysis of YY1 revealed that it contains an established RNA binding motif located within the zinc fingers. A series of biochemical assays were performed to address the possibility that YY1 functions as a component of mRNPs in the oocyte cytoplasm. RNA gel mobility shift analyses using in vitro synthesized histone H2A transcripts and supershifts using YY1-specific antibodies suggested that YY1 or YY1-containing complexes in cytoplasmic extracts were able to bind RNA. Chromatographic analysis of oocyte lysates showed YY1 was specifically retained on oligo (dT) cellulose columns. Treatment of the same lysates with RNase abolished binding to oligo (dT), indicating that retention is dependent on the presence of intact polyadenylated RNAs. This suggested that YY1 may be a component of messenger ribonucleoprotein particles (mRNP). Separation of oocyte lysates by size exclusion chromatography (SEC) revealed that YY1 was present in large complexes with an approximate molecular mass of 480 kDa. RNase or phosphatase treatment of oocyte extracts released YY1 from high mass complexes. Analysis of phosphatase or RNase-treated extracts for DNA binding activity showed that monomeric YY1 was able to bind DNA with high affinity. Immunoprecipitation of YY1 complexes followed by cDNA synthesis and sequencing revealed that YY1 is associated with both ribosomal and messenger RNAs in the cytoplasm of the oocyte. These results indicate a novel function for YY1 as a component of messenger ribonucleoprotein particles.

Yin Yang 1 (YY1) is a multifunctional transcription factor that is known mainly for its ability to activate or initiate transcription of a wide assortment of genes involved in cellular growth and differentiation. <i>Xenopus laevis </i>oocytes and embryos were used as a model to identify and characterize a potential developmental role for YY1. Northern and Western blots of oocyte and embryonic extracts showed YY1 mRNA and protein is expressed from the earliest stages of oocyte development through to tadpole stages. Examination of the transcriptional activity of YY1 in both oocytes and embryos using reporter gene constructs containing YY1-binding elements demonstrated that YY1 does not act as a repressor or activator of transcription either in oocytes or in embryos. Sub-cellular fractionation of oocytes and Western blot analysis showed YY1 is localized almost exclusively to the cytoplasm of oocytes and in cells of early embryos. Sequence analysis of YY1 revealed that it contains an established RNA binding motif located within the zinc fingers. A series of biochemical assays were performed to address the possibility that YY1 functions as a component of mRNPs in the oocyte cytoplasm. RNA gel mobility shift analyses using in vitro synthesized histone H2A transcripts and supershifts using YY1-specific antibodies suggested that YY1 or YY1-containing complexes in cytoplasmic extracts were able to bind RNA. Chromatographic analysis of oocyte lysates showed YY1 was specifically retained on oligo (dT) cellulose columns. Treatment of the same lysates with RNase abolished binding to oligo (dT), indicating that retention is dependent on the presence of intact polyadenylated RNAs. This suggested that YY1 may be a component of messenger ribonucleoprotein particles (mRNP). Separation of oocyte lysates by size exclusion chromatography (SEC) revealed that YY1 was present in large complexes with an approximate molecular mass of 480 kDa. RNase or phosphatase treatment of oocyte extracts released YY1 from high mass complexes. Analysis of phosphatase or RNase-treated extracts for DNA binding activity showed that monomeric YY1 was able to bind DNA with high affinity. Immunoprecipitation of YY1 complexes followed by cDNA synthesis and sequencing revealed that YY1 is associated with both ribosomal and messenger RNAs in the cytoplasm of the oocyte. These results indicate a novel function for YY1 as a component of messenger ribonucleoprotein particles.

It is commonly known that coastal vegetation dissipates energy and aids in shoreline protection by damping incoming waves and depositing sediment in vegetated regions. However, this critical role of vegetation to dampen wave forces is not fully understood at present. A series of laboratory experiments were conducted in the Haynes Coastal Laboratory and 2-D flume at Texas A&M University to examine different vegetative scenarios and analyze the wave damping effects of incident wave height, stem density, wave period, plant type, and water depth with respect to stem length. In wetland regions vegetation is one of the main factors influencing hydraulic roughness. Traditional open-channel flow equations, including the Manning and Darcy- Weisbach friction factor approach, have been successfully applied to determine bottom friction coefficients for flows in the presence of vegetation. There have been numerous relationships derived relating the friction factor to different flow regime boundary layers to try and derive a wave friction factor for estimating energy dissipation due to bottom bed roughness. The boundary layer problem is fairly complex, and studies relating the wave friction factor to vegetation roughness elements are sparse. In this thesis the friction factor is being applied to estimate the energy dissipation under waves due to artificial vegetation. The friction factor is tuned to the laboratory experiments through the use of the numerical model COULWAVE so that the pipe flow formulation can be reasonably applied to wave problems. A numerical friction factor is found for each case through an iterative process and empirical relationships are derived relating the friction factor for submerged and emergent plant conditions to the Ursell number. These relationships can be used to reasonably estimate a wave friction factor for practical engineering purposes. This thesis quantitatively analyzes wave damping due to the effects of wave period, incident wave height, horizontal stem density, water depth relative to stem length, and plant type for a 6 m plant bed length. A friction factor is then determined numerically for each of the laboratory experiments, and a set of equations is derived for predicting a roughness coefficient for vegetation densities ranging between 97 stems/m2 and 162 stems/m2.

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This thesis mainly studies the active power factor correction circuit using a new AC/DC Single Ended Primary Inductance Converter (SEPIC). For power factor correction, inductor current is operated in the continuous conduction mode. First of all, the converter is analyzed by state space averaging method. Furthermore, the operational principle of PFC circuit with PI control law is analyzed. A good power factor system is then developed by time-domain and frequency-domain analysis. A classical PFC circuit with PI control law has low power factor when light load. In order to overcome problem, the thesis proposes a SEPIC circuit with robust performance. Compared with circuits using classical PI controller and PFC IC, the proposed system obtains higher power factor under the condition of the same light load.

During administer mobil source examine and control plan , we must estimate emission amount , curtail amount and curtail rate , to estimate the improve effection . But there has very few data of this aspect , especially real road driving pattern to calcul ate emission factory and amount . So it¡¦s necessary to proceed this aspect investigate. The investigate have two parts include driving pattern and emission factor . Determine item is CO , THC and NOx .The result of driving Ping-tung area have faster speed,longer navigate time and larger acceleration and deceleration . The result of emission factor¡GCO is 6.79 (¡Ó3.39) g/km , THC is 1.63 (¡Ó1.27) g/km and NOx is 0.13(¡Ó0.14) g/km . Idle emission CO is 1.03%(¡Ó1.19%)¡ATHC is 1400(¡Ó2138) ppm