Search

Aneuploidy is defined as a state of having an abnormal number of chromosomes within a cell. In human, congenital aneuploidy is the leading cause of developmental abnormality and mental retardation. Somatically acquired aneuploidy has long been known as a hallmark of cancer genome. While multiple studies have focused on dissecting the molecular mechanisms leading to aneuploidy, little has been done to address its consequences. Using budding yeast Saccharomyces cerevisiae as model organism, we first asked whether and how aneuploidy could bring about phenotypic variation. We monitored the growth of a panel of 38 isogenic and relative stable aneuploid strains under various conditions including a panel of chemotherapeutic and antifungal drugs. We found that some aneuploid strains grew significantly faster than euploid control strains in various conditions. Using quantitative proteomic, we showed that aneuploidy could induce large change to the cellular proteome and the levels of protein expression largely scale with chromosome copy numbers. Together, these findings suggest that aneuploidy, through its effect on proteome, could underlie phenotypic variation.

The aim of this study was to evaluate the growth supporting value of DE derived from gut fermentation in growing pigs. Unmolassed sugar beet pulp (SBP) was selected as a model material for fermentation. For a reference material which would be digested in the small intestine by the endogenous enzymes, maize starch (MS) was selected. A cereal-based control diet was formulated to fulfil the needs of pigs for all essential nutrients apart from energy. To this control diet, either SBP (150 & 300 g/kg) or MS (100 & 200 g/kg) were added. The study consisted of two phases. The first phase (digestion trial and growth trial) was devoted to studying the digestion of these diets and to comparing the effects on growth of pigs of the two DE sources (SBP and MS). The second phase was to determine the production of VFA resulting from the fermentation of SBP. Methods used included stoichiometric calculations based on measurements of the molar proportions of VFA combined with CH4 production, and a direct assessment of the true fermented materials using antibiotics to suppress fermentation. The results of the first phase showed that the energy in SBP and MS had an apparent digestibility of 0.74 and 0.98. The DE from SBP was used for supporting carcass gain with an efficiency of 0.57 of the DE from MS. The results of the second phase indicated that measurements of methane production alone or even with inclusion of free hydrogen could underestimate the extent of fermentation in the gut of pigs. The results also suggest that with the cereal-based control diet, fermentation could supply up to 13.6% of the dietary DE in the form of VFA or 18.0% in the form of fermented energy. For this control diet incorporating 30% SBP, the respective values were 25.4% and 33.4%. The absorbed VFA resulting from the fermentation of SBP had a growth supporting value of 0.763 of that of absorbed glucose from MS.

The rapid development of enantioselective allylic or propargylic C − H functionalization methods offers great opportunities for introducing functional groups to readily available starting materials in a stereodefined manner. In this dissertation, we synthesized N-heterocyclic molecules from simple alkynes with good regioselectivity utilizing stoichiometric Fe intermediates. The achievement of highly enantioselective allylic functionalization of non-activated alkenes was realized through the synergistic combination of Fe and Ir catalysts. In addition, we systematically investigated the enantioselective propargylic functionalization with Ir catalysis, thereby expanding the scope pf propargylic functionalization. A wide range of alkynes underwent successful propargylic allylation and silylation, enabling the formation of 1,5-dienes, propargylsilanes and allenylsilanes with good enantioselective and stereoselective control.

Against a global backdrop of growing concerns on housing crises, Chinese megacities have earned unwelcome distinction as among the world’s least affordable housing markets. Spatial planning, as a supply-side institutional component of housing systems, has formed a prime focus of contestation on factors influencing housing outcomes, especially in Anglosphere nations. Rarely, however, have such debates been conducted regarding housing markets in China. Crucially, while spatial planning in some advanced economies has weathered trenchant criticism informed by a neo-liberal mentality, planning in China is prioritised by local governments as a vital tool of pro-growth governance. Focusing on Shanghai, as representative of Chinese megacities, this thesis explores how a pro-growth planning regime has contributed to housing outcomes in this urban context. It is guided by three questions: How has developable land supply affected housing affordability? How are residential property values influenced by local plans? How has the planning regime contributed to housing outcomes for low-income groups? To address them, both qualitative and quantitative techniques are employed. Research findings confirm that planning policy contributes to sub-optimal housing system performance. Specifically, while serving state interests and fulfilling diverse policy aspirations, restrictive land release stimulates market speculation; amenity distribution and zoning regulations reinforce metropolitan mono-centricity and house price dynamics which induce socio-spatial sifting of low-income groups into the least favourable locations. Moreover, the inadequate arrangement of public housing for hukou populations and rising clearance of informal housing accommodating non-local hukou populations undermine their wellbeing. As a governmental toolset mainly acting to promote state accumulation and authority, Shanghai’s pro-growth planning regime accords little priority to the social needs of low-income populations. In cities like Shanghai, resulting housing outcomes are compounding inequality, damaging socio-political stability and impairing urban productivity. The planning paradigm calls for a transition from state-interests-driven to social-needs-driven approaches for equitably distributed prosperity, social cohesion and wellbeing. Albeit that public landownership and a positive planning regime could contribute to these objectives, achievement of such a transition calls for strong political willpower.

The cornea is consisted with continuous and smooth epithelial cells in the center and limbal stem cells in the edge. Their transparency plays important role in maintaining our vision. Any deficiency in cornea epithelial cells (CECs) or limbal stem cells (LSCs) will lead to transparency lost and blindness. In our study, we successfully developed a protocol for cell culture to expand LSCs from human donors and animal tissues. Enabling us to generate a homogenous cell population to study key factors involved in LSCs fate determination and CEC differentiation. Through the genome-wide gene expression analysis, we found WNT7A and PAX6 were highly involved in LSCs and CECs, which gave us a insight of these two genes regulation for limbal stem cell fate determination.