Doctor of Philosophy

dissertationThe use of multicarrier techniques has allowed the rapid expansion of broadband wireless communications. Orthogonal frequency division multiplexing (OFDM) has been the most dominant technology in the past decade. It has been deployed in both indoor Wi-Fi and cellular environments, and has been researched for use in underwater acoustic channels. Recent works in wireless communications include the extension of OFDM to multiple access applications. Multiple access OFDM, or orthogonal frequency division multiple access (OFDMA), has been implemented in the third generation partnership project (3GPP) long- term evolution (LTE) downlink. In order to reduce the intercarrier interference (ICI) when user's synchronization is relaxed, filterbank multicarrier communication (FBMC) systems have been proposed. The first contribution made in this dissertation is a novel study of the classical FBMC systems that were presented in 1960s. We note that two distinct methods were presented then. We show that these methods are closely related through a modulation and a time/frequency scaling step. For cellular channels, OFDM also has the weakness of relatively large peak-to-average power ratios (PAPR). A special form of OFDM for the uplink of multiple access networks, called single carrier frequency division multiple access (SC-FDMA), has been developed to mitigate this issue. In this regard, this dissertation makes two contributions. First, we develop an optimization method for designing an effective precoding method for SC-FDMA systems. Second, we show how an equivalent to SC-FDMA can be developed for systems that are based on FBMC. In underwater acoustic communications applications, researchers are investigating the use of multicarrier communication systems like OFDM in underwater channels. The movement of the communicating vehicles scales the received signal along the time axis, which is often referred to as Doppler scaling. To undo the signal degradation, researchers have investigated methods to estimate the Doppler scaling factor and restore the original signal using resampling. We investigate a method called nonuniform fast Fourier transform (NUFFT) and apply that to increase the precision in the detection and correction of the Doppler scaling factor. NUFFT is applied to both OFDM and FBMC and its performance over the experimental data obtained from at sea experiments is investigated

The Guangdong Model of Urbanisation

In some parts of China – and especially in Guangdong Province in southern China – rural communities have retained ownership of much of their land when its use is converted into urban neighbourhoods or industrial zones. In these areas, the rural collectives, rather than disappearing, have converted themselves into property companies and have been re-energised and strengthened as rental income pours into their coffers. The native residents, rather than being relocated, usually remain in the village’s old residential area. As beneficiaries of the profits generated by their village collective, they have become a new propertied class, often living in middle-class comfort on their dividends and rents. How this operates – and the major economic and social ramifications – is examined through onsite research in four communities: an industrialised village in the Pearl River delta; an urban neighbourhood in Shenzhen with its own subway station, whose land is still owned and administered by rural collectives; and two villages-in-the-city in Guangzhou’s new downtown districts, where fancy housing estates and high-rise office blocks owned by village collectives are springing up alongside newly rebuilt village temples and lineage halls

The Guangdong Model of Urbanisation

In some parts of China – and especially in Guangdong Province in southern China – rural communities have retained ownership of much of their land when its use is converted into urban neighbourhoods or industrial zones. In these areas, the rural collectives, rather than disappearing, have converted themselves into property companies and have been re-energised and strengthened as rental income pours into their coffers. The native residents, rather than being relocated, usually remain in the village’s old residential area. As beneficiaries of the profits generated by their village collective, they have become a new propertied class, often living in middle-class comfort on their dividends and rents. How this operates – and the major economic and social ramifications – is examined through onsite research in four communities: an industrialised village in the Pearl River delta; an urban neighbourhood in Shenzhen with its own subway station, whose land is still owned and administered by rural collectives; and two villages-in-the-city in Guangzhou’s new downtown districts, where fancy housing estates and high-rise office blocks owned by village collectives are springing up alongside newly rebuilt village temples and lineage halls

Le modèle d’urbanisation du Guangdong

Dans certaines parties de la Chine, et particulièrement au sud, dans la province du Guangdong, les communautés rurales ont conservé la propriété de la plupart de leurs terres après que leur usage a été converti en quartiers urbains ou zones industrielles. Dans ces zones, les comités villageois n’ont pas complètement disparu mais se sont transformés en sociétés collectives de gestion foncière, se renforçant grâce aux revenus locatifs ainsi générés. Au lieu d’être relogés, les résidents d’origine demeurent généralement dans l’ancienne zone résidentielle du village. Bénéficiant des revenus engendrés par leur société de gestion foncière, ils sont devenus une nouvelle classe de propriétaires vivant de dividendes et de loyers, et se sont hissés au niveau de confort de la classe moyenne. Nous avons analysé le fonctionnement de ce système ainsi que ses principales ramifications économiques et sociales dans le cadre d’une recherche de terrain menée dans quatre communautés : un village industriel dans le delta de la rivière des Perles, un quartier urbain de Shenzhen possédant sa propre station de métro et dont le terrain est toujours détenu et administré collectivement par les anciens villageois, et deux « villages-dans-la-ville » situés dans les nouveaux districts centraux de Canton où des lotissements chics et des tours de bureaux appartenant aux sociétés de gestion foncière poussent aux côtés de temples de villages et de temples lignagers récemment reconstruits

Le modèle d’urbanisation du Guangdong

Dans certaines parties de la Chine, et particulièrement au sud, dans la province du Guangdong, les communautés rurales ont conservé la propriété de la plupart de leurs terres après que leur usage a été converti en quartiers urbains ou zones industrielles. Dans ces zones, les comités villageois n’ont pas complètement disparu mais se sont transformés en sociétés collectives de gestion foncière, se renforçant grâce aux revenus locatifs ainsi générés. Au lieu d’être relogés, les résidents d’origine demeurent généralement dans l’ancienne zone résidentielle du village. Bénéficiant des revenus engendrés par leur société de gestion foncière, ils sont devenus une nouvelle classe de propriétaires vivant de dividendes et de loyers, et se sont hissés au niveau de confort de la classe moyenne. Nous avons analysé le fonctionnement de ce système ainsi que ses principales ramifications économiques et sociales dans le cadre d’une recherche de terrain menée dans quatre communautés : un village industriel dans le delta de la rivière des Perles, un quartier urbain de Shenzhen possédant sa propre station de métro et dont le terrain est toujours détenu et administré collectivement par les anciens villageois, et deux « villages-dans-la-ville » situés dans les nouveaux districts centraux de Canton où des lotissements chics et des tours de bureaux appartenant aux sociétés de gestion foncière poussent aux côtés de temples de villages et de temples lignagers récemment reconstruits

The in vivo Therapeutic Effect of Free Wanderer Powder (逍 遙 散 xiāo yáo sǎn, Xiaoyaosan) on Mice with 4T1 Cell Induced Breast Cancer Model

ABSTRACTIn the present study, we investigated the therapeutic effect of a classical TCM formula, Free Wanderer Powder (逍遙散 xiāo yáo sǎn), in a breast cancer mouse model induced with estrogen-insensitive breast cancer 4T1 cells. Ovariectomized Balb/c mice (6-8 weeks) or sham mice were injected into the fourth mammary fat pad with 4T1 cells in which tumors were palpable 7days after injection. On the eighth day, the mice were divided into 4 groups and tubefed daily with vehicle, Free Wanderer Powder (逍遙散 xiāo yáo sǎn) formula or tamoxifen for 28days. Tumor growth inhibition and the decrease of the average tumor mass were most evident in mice treated with Free Wanderer Powder (逍遙散 xiāo yáo sǎn). Free Wanderer Powder (逍遙散 xiāo yáo sǎn) treatment significantly reduced Bcl-2 and elevated Bax and p53 protein expressions in breast cancer tumor. These results were further confirmed by immunohistochemisty. Tamoxifen could decrease spleen mass and Bcl-2 protein expression, increase the Bax protein expression as well as exert uterotrophic effects by increasing uterus index and inducing the gene expressions in the uterus. Taken together, these results show that Free Wanderer Powder (逍遙散 xiāo yáo sǎn) treatment induced apoptosis at protein level and inhibited the tumor growth in 4T1-induced ovariectomized Balb/c female mice, indicating the possibility of its future use for treatment of estrogen-insensitive breast caner

Genome-Wide Association Study of Hepatocellular Carcinoma in Southern Chinese Patients with Chronic Hepatitis B Virus Infection

One of the most relevant risk factors for hepatocellular carcinoma (HCC) development is chronic hepatitis B virus (HBV) infection, but only a fraction of chronic HBV carriers develop HCC, indicating that complex interactions among viral, environmental and genetic factors lead to HCC in HBV-infected patients. So far, host genetic factors have incompletely been characterized. Therefore, we performed a genome-wide association (GWA) study in a Southern Chinese cohort consisting of 95 HBV-infected HCC patients (cases) and 97 HBV-infected patients without HCC (controls) using the Illumina Human610-Quad BeadChips. The top single nucleotide polymorphisms (SNPs) were then validated in an independent cohort of 500 cases and 728 controls. 4 SNPs (rs12682266, rs7821974, rs2275959, rs1573266) at chromosome 8p12 showed consistent association in both the GWA and replication phases (ORcombined = 1.31–1.39; pcombined = 2.71×10−5–5.19×10−4; PARcombined = 26–31%). We found a 2.3-kb expressed sequence tag (EST) in the region using in-silico data mining and verified the existence of the full-length EST experimentally. The expression level of the EST was significantly reduced in human HCC tumors in comparison to the corresponding non-tumorous liver tissues (P<0.001). Results from sequence analysis and in-vitro protein translation study suggest that the transcript might function as a long non-coding RNA. In summary, our study suggests that variations at chromosome 8p12 may promote HCC in patients with HBV. Further functional studies of this region may help understand HBV-associated hepatocarcinogenesis