Each individual cell is a highly dynamic and complex system. Characterizing dynamics of gene expression and signal transduction is essential to understand what underlie the behavior of the cell and has stimulated much interest in systems biology. However, traditional techniques based on population averages 'wash out' crucial dynamics that are either out of phase among cells or are driven by stochastic cellular components[34]. In this work, we combined time-lapse microscopy, quantitative image analysis and fluorescent protein reporters, which allowed us to directly observe multiple cellular components over time in individual cells. In conjunction with mathematical models, we have investigated three dynamical systems, two of which are based on a long-term genealogical tracking method. First, we found that stochastic switching between different gene expression states in budding yeast is heritable[29]. This striking behavior only became evident using genealogical information from growing colonies. Our model based on burst induced correlation can explain the bulk of our results. In the next system investigated, we explored the interaction between biological oscillators. Especially, we used an abstract model to describe and predict the synchronization of cell cycles by the circadian clock. Simultaneous measurement of both circadian dynamics and cell cycle dynamics in individual cyanobacteria cells revealed the direct relationships between these two biological clocks and thus provided a clear evidence of 'circadian gating', in which circadian rhythms regulate the timing of cell divisions. Lastly, we studied the robustness of the network dynamics to the sequence changes and the changes of gene expression levels of embedding proteins by characterizing dynamic response of the well-conserved mitogen-activated protein kinase (MAPK) cascade to osmotic shock, combining experimental measurements and theoretical models.

Right Heart Catheterization (RHC) is a common procedure applied in critically ill patients. In US, over 1 million cases of RHC procedures are conducted annually at present. In particular, patients with low blood pressure, lung water, hearts abnormalities, kidney abnormalities are usually the targeted group to receive theprocedure. Although there is no absolute clinical contradiction with the use of RHC, its effect has not been statistically validated using randomized controlled trials due to the lack of randomized data. Instead, studies on RHC have been using observational data to quantify its causal effect, which should be taken with caution because of the issues in estimating true causal effect in observational studies.In my study, I reinvestigate the causal effect of RHC on subsequent survival using observational data and several multivariate matching schemes including nearest neighbor matching, optimal matching, full matching and genetic matching. Data for the study is from the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT), with a total of 5735 subjects.Our study has three main findings. First, RHC increased the risk of dth30, after controlling for the observed confounders under each of the four matching schemes, which coincides with earlier studies using SUPPORT data. Second, theMonte Carlo simulation experiment conducted in our analysis suggests that our conclusion on the causal effect of RHC is robust because: 1) The bias, defined by the difference between true and estimated causal effect, is small with acceptable variance; 2) Our simulation results are robust to a variety of specifications on additivity and/or linearity in the relationship between confounders and the treatment indicator. However, for the case where strong nonlinearity is present, the model performance is not as good as in other scenarios. Third, this negative causal effect is sensitive to the possible hidden bias identified by sensitivity analysis. However, the performances of these four matching schemes are different confronting hiddenbias. Full matching gives the most robust result compared to other three matching schemes.

Science has long been an inseparable part of life, but the idea of science has been developed only in recent centuries. In China, the term “science” became known only in the last century. Science education, the discourse of science, and popular imagination of science emerged only during the past hundred and twenty years, over which time they gradually gained recognition. This dissertation investigates how science appeared in literature and other cultural works. It examines fictional and nonfictional literary works, as well as films, that are representative of their times. Through textual analysis, comparison, and discussion of historical contexts, the dissertation reveals the complexity of the understanding of science in the Chinese popular imagination. The four chapters of the body of the dissertation discuss the change in meaning of the term science, how Chinese scientists understood science as a way to “save” China, the changing image of the scientist, and the encounter of “East” and “West” in popular cultural products concerning science. The dissertation argues that nationalism and politics has accompanied the reception of science in China in the popular cultural realm, and that in recent decades, its reception has become more diversified. Although cultural images of science changed over time, a positive and optimistic understanding of science has been a consistent thread in the Chinese cultural discourse.

Abstract: This thesis analyzes the fictional works of Gu Junzheng (1902-1980), an important writer and editor of Chinese science fiction and scientific essays. As a representative writer of science fiction of his time, Gu Junzheng's works provide a chance for us to take a glance into a particular moment in the history of Chinese science fiction--the late 1930s and early 1940s, a period that has not been sufficiently studied. Because science is such an important concept in the modern world--C.P. Snow (1959) argues that there is a "scientific culture" in industrialized societies--examining literary representations of science can be helpful for understanding how science gradually yet profoundly changed people's view of the world. My study sets Gu's work in the genealogy of Chinese science fiction, which flourished in the late Qing period into early Republican period, fell into a low tide in the 1930s, experienced another round of peak and valley between the 1960s and 1980s, and then has prospered again from the 1990s to the present. Ever since its beginning in China, the genre has been highly political, because science, conceived as a progressive force, was always intertwined with the national discourse. Yet there were also other perspectives in science fiction, and Gu's works, in particular, brought many new elements to the genre.

With rapid technological advances in the second half of last century, the increasing dependence on science-based agriculture has placed greater importance on the fast and efficient transfer of the advanced knowledge to farmers. For most of countries, without an efficient agricultural sector, a country is severely constrained in its ability to feed itself and in consuming other goods and its development.Agricultural extension is one of the most common forms of public support to enhance the agricultural productivity. With costs rising, limited resources available, decreasing proportion of agricultural sector in the economy and changes in the prevailing philosophy of the appropriate extent of government intervention, it becomes more imperative to improve the performance of agricultural extension.Our research focuses on quantifying these changes brought up by agricultural extension. Existing literature on this quantification work on agricultural extension is scarce and inconclusive. Measuring the technical efficiency in a variety of fields has achieved rapid progress via the newly adopted econometric toolboxes; however, the corresponding work in agricultural extension failed to keep in pace. One particular aspect that has been overlooked in agricultural extension literature is the possibility of sample selectivity.Given the public goods nature of agricultural extension, one should distinguish between the two production processes that are involved. In the first stage, an intermediate output is produced using only discretionary inputs (i.e.,variable and controllable by the decision making unit). In the second stage, final outcomes are determined by the level of the intermediate output and by environmental (i.e.,fixed) variables.In quantifying the technical efficiency levels present at the farm level, we extend the existing framework on measuring technical efficiency to account for sample selectivity. Stochastic production frontier approach with accommodations for sample selectivity is used to measure technical efficiency and technical efficiency scores of individual farm. In addition, we test for sample selectivity from the statistical causal effect perspective.An empirical study is conducted based on this extended framework and some hypothesis testing of our interest will be done as well. Our study confirms the existence of sample selectivity from both econometrical and statistical approaches. Efficiency scores are calculated based on our econometrical estimation procedure. Comparisons between farms receiving and those not receiving extension visits are made. We find that there is no significant difference in the level of technical efficiency between these two types of farms. However, farms receiving the extension services have higher productivity level than those not receiving extension services. This finding is consistent with the existence of sample selection. Farms' herd behavior, debt/asset ratio and education level are identified as possible sources of sample selectivity. We also reinforce the conclusion of the existence of sample selectivity following causal inference approach. Several matching algorithms are conducted. Similar conclusions are drawn as in the econometric approach.At the macro level, a static game theoretic model with incomplete information adapted from mechanism design is developed to characterize the interactions among all participants in the two production processes. Extension agents are assumed to have up to three different types characterized by productivity levels. The government's objective is to maximize social welfare by setting up a truth-telling mechanism subject to a set of constraints. Equilibrium results and policy implications are discussed. To our knowledge, this is the first attempt to analyze the interactions of the government, extension agents and farms using game theoretic model. A simulation study is conducted to learn the comparative statics, which is based on the two nonlinear equation systems provides us insight into the impact of productivity difference among agents on economic variables of our interest.Based on our study, policy implications can be multi-fold. At the micro level, policy makers should alleviate the possible influence of sample selection in farm's choices of extension services. Several instruments identified in our analysis including educational level, debt status can serve for such a purpose. At the macro level, we establish a solid foundation that government should be less involved in specific production process of extension service. Our findings are consistent with the decreasing resource allocation to agricultural sector and the increasing financial, human resource input by nongovernment organization and many other private sectors. In addition, the different reaction patterns to the changes in relative productivity may guide policy makers to design mechanisms suitable to different types of extension agencies. In particular, the different price reaction curves to the change in relative productivity may be studied so that extension agencies charger different prices to different farm types. In this case, the true demand rather than the demand distorted by sample selectivity can be more accurately identified.Following future research is of our particular interest. Our estimation of stochastic production frontier function is limited due to data availability in several aspects. In particular, farm types are classified as receiving and not receiving extension services. The exploration may go deeper if we can further distinguish between private and public extension service provision. Increasing the number of individual farms in our data set would make it possible to compare the performance of private extension services to that of public extension services.

As the fast development of the electronic portable devices and drastic fading of fossil energy sources. The need for portable secondary energy sources is increasingly urgent. As a result, lithium ion batteries are being investigated intensely to meet the performance requirements. Among various electrode materials, the most expensive and capacity limiting component is the positive materials. Based on this, researches have been mostly focused on the development of novel cathode materials with high capacity and energy density and the lithium transition metal orthosilicates have been identified as possible high performance cathodes. Here in, we report the synthesis of a kind of lithium transition metal orthosilicates electrode lithium manganese silicate. Lithium manganese silicate has the advantage of high theoretical capacity, low cost raw material and safety. In this thesis, lithium manganese silicate are prepared using different silicon sources. The structure of silicon sources preferred are examined. Nonionic block copolymers surfactant, P123, is tried as carbon source and mophology directing agent. Lithium manganese silicate's performances are improved by adding P123.