Off-farm Work, Technical Efficiency, and Production Risk: Empirical Evidence from a National Farmer Survey in Taiwan

The objective of this paper is to investigate the differences in yield production, production efficiency, and yield risk for farmers with and without off-farm work. Using a nationwide survey of Taiwanese rice farmers, we estimate a stochastic production frontier model accommodating the technical inefficiency and the production risk simultaneously. Applying the stochastic dominance criterion to rank the estimated technical efficiency and yield risk between professional farmers and farmers with off-farm jobs, our empirical analysis shows that off-farm work is significantly associated with lower technical efficiency. Additionally, farmers with off-farm work face higher production risks. Comparing the marginal effects of input uses on technical inefficiency and yield risk between these groups of farmers, we found a substantial heterogeneity of input uses between these two groups of farmers.Off-farm work, technical efficiency, production risk, Taiwan, Crop Production/Industries, Farm Management,

Migration, Social Security, and Economic Growth

This paper studies the effect of population aging on economic performance in an overlapping-generations model with international migration. Fertility is endogenized so that immigrants and natives can have different fertility rates. Fertility is an important determinant to the tax burden of social security since it affects the quantity and quality of future tax payers. We find that introducing immigrants into the economy can reduce the tax burden of social security. If life expectancy (or the replacement ratio) is high enough, the growth rate of GDP per worker for an economy with international migration will be higher than for a closed economy. Regarding migration policies, our numerical results indicate that economic growth rate of GDP per worker will first decrease then increase as the flow of immigrants increases. Increasing the quality of immigrants will enhance economic growth.Economic growth; Fertility; Migration; Social security.

Governing carbon: China in global climate politics

The aim of this thesis is to examine the dynamics of China’s engagement with global climate change. After critically reviewing mainstream neo-realist and neo-liberal institutionalist approaches to International Relations and climate change, the thesis develops a revised governmentality framework based on a critical engagement with critical IPE and Foucauldian approaches. This provides the basis for an analytical framework focusing on four distinct ‘rationalities of government’ in China’s climate change politics and governance, which are sovereignty, development, market and the environment. The genealogical examination of these four governmental rationalities has demonstrated the dynamics among them and the relations of state/society/party in China. By applying this analytical framework, the thesis critically examines two distinctive fields of China’s climate change politics: international politics and the Clean Development Mechanism in China. The thesis argues that although neo-liberal governmentality appears dominant in global climate politics, the case study of China reveals different dynamics in which the rationalities of sovereignty and development have played the more influential roles. By contrast, the market rationality has been instrumentalised in China for the pursuit of economic growth and the environmental rationality has been marginalised. The thesis contends that the uneven relations among these rationalities have to be grasped through historical and contextual exploration. Different paths and mentalities of state formation and modernisation have had significant influences on China’s politics and governance of climate change in both international and domestic levels. The findings from this research help to explain the changes and continuities in China’s positions in international climate negotiations, in its regulation of the carbon market, and in the formation of climate knowledge and mentalities under the rule of the Communist Part

Roles of the Mother Centriole Appendage Protein Cenexin in Microtubule Organization during Cell Migration and Cell Division: A Dissertation

Epithelial cells are necessary building blocks of the organs they line. Their apicalbasolateral polarity, characterized by an asymmetric distribution of cell components along their apical-basal axis, is a requirement for normal organ function. Although the centrosome, also known as the microtubule organizing center, is important in establishing cell polarity the mechanisms through which it achieves this remain unclear. It has been suggested that the centrosome influences cell polarity through microtubule cytoskeleton organization and endosome trafficking. In the first chapter of this thesis, I summarize the current understanding of the mechanisms regulating cell polarity and review evidence for the role of centrosomes in this process. In the second chapter, I examine the roles of the mother centriole appendages in cell polarity during cell migration and cell division. Interestingly, the subdistal appendages, but not the distal appendages, are essential in both processes, a role they achieve through organizing centrosomal microtubules. Depletion of subdistal appendages disrupts microtubule organization at the centrosome and hence, affects microtubule stability. These microtubule defects affect centrosome reorientation and spindle orientation during cell migration and division, respectively. In addition, depletion of subdistal appendages affects the localization and dynamics of apical polarity proteins in relation to microtubule stability and endosome recycling. Taken together, our results suggest the mother centriole subdistal appendages play an essential role in regulating cell polarity. A discussion of the significance of these results is included in chapter three

Optical Torque from Enhanced Scattering by Multipolar Plasmonic Resonance

We present a theoretical study of the optical angular momentum transfer from a circularly polarized plane wave to thin metal nanoparticles of different rotational symmetries. While absorption has been regarded as the predominant mechanism of torque generation on the nanoscale, we demonstrate numerically how the contribution from scattering can be enhanced by using multipolar plasmon resonance. The multipolar modes in non-circular particles can convert the angular momentum carried by the scattered field, thereby producing scattering-dominant optical torque, while a circularly symmetric particle cannot. Our results show that the optical torque induced by resonant scattering can contribute to 80% of the total optical torque in gold particles. This scattering-dominant torque generation is extremely mode-specific, and deserves to be distinguished from the absorption-dominant mechanism. Our findings might have applications in optical manipulation on the nanoscale as well as new designs in plasmonics and metamaterials.Comment: main article 20 pages, 4 figures; supplementary material 6 pages, 2 figure

Responses of heat shock protein 70 and caspase-3/7 to dietary selenomethionine in juvenile white sturgeon.

An 8-week feeding trial was conducted to investigate the responses of juvenile white sturgeon (Acipenser transmontanus) to elevated dietary selenium (Se) based on the determination of the RNA/DNA ratio in muscle, heat shock protein 70 (Hsp70), and caspase-3/7 in muscle and/or liver tissues. Four semi-purified test diets were prepared by adding different levels of L-selenomethionine (0, 50, 100, and 200 mg/kg diet). The analytical determinations of total Se were 2.2, 19.7, 40.1, and 77.7 mg/kg diet. The sturgeon (initial body weight: 30 ± 2 g; mean ± SEM) were raised in indoor tanks provided with flow through freshwater (18-19 °C). There were three replicates for each dietary treatment with 25 fish per replicate. The liver and muscle tissues were collected at 4 and 8 weeks after feeding the test diets. A significant interaction between duration and levels of dietary Se exposures on RNA/DNA ratio in the muscle tissue was detected (P < 0.05). Although there was no significant main effect due to the duration of dietary Se exposures (i.e., 4 weeks versus 8 weeks) on muscle RNA/DNA ratio (P ≥ 0.05), the ratio was significantly decreased with increasing dietary Se levels. Significant main effects were caused by the duration and levels of dietary Se exposures on Hsp70 in both the muscle and liver tissues, with significant increases in Hsp70 due to a longer exposure (8 weeks) and higher levels (40.1 and 77.7 mg Se/kg diet) of dietary Se. The caspase-3/7 activity in the liver were significantly higher in fish fed the diets containing 40.1 and 77.7 mg Se/kg diet than those fed the other diets. The toxic thresholds of Se in the muscle were estimated to be 32.2 and 26.6 mg Se/kg for the depressed specific growth rate and the induced Hsp70 response in muscle, respectively. This result indicated that the Hsp70 response in muscle is a more sensitive biomarker than the SGR of sturgeon for evaluating Se toxicity in white sturgeon. Results of the current study suggest that a mechanism involved with the activation of stress protein production and apoptosis protects white sturgeon from the lethal effect of Se

Transformation Optics scheme for two-dimensional materials

Two dimensional optical materials, such as graphene can be characterized by a surface conductivity. So far, the transformation optics schemes have focused on three dimensional properties such as permittivity $\epsilon$ and permeability $\mu$. In this paper, we use a scheme for transforming surface currents to highlight that the surface conductivity transforms in a way different from $\epsilon$ and $\mu$. We use this surface conductivity transformation to demonstrate an example problem of reducing scattering of plasmon mode from sharp protrusions in graphene

Umbilic hypersurfaces of constant sigma-k curvature in the Heisenberg group

We study immersed, connected, umbilic hypersurfaces in the Heisenberg group $H_{n}$ with $n$ $\geq$ $2.$ We show that such a hypersurface, if closed, must be rotationally invariant up to a Heisenberg translation. Moreover, we prove that, among others, Pansu spheres are the only such spheres with positive constant sigma-k curvature up to Heisenberg translations.Comment: 28 pages, 6 figure

Electron-photon scattering mediated by localized plasmons: A quantitative analysis by eigen-response theory

We show that the scattering interaction between a high energy electron and a photon can be strongly enhanced by different types of localized plasmons in a non-trivial way. The scattering interaction is predicted by an eigen-response theory, numerically verified by finite-difference-time-domain simulation, and experimentally verified by cathodoluminescence spectroscopy. We find that the scattering interaction associated with dark plasmons can be as strong as that of bright plasmons. Such a strong interaction may offer new opportunities to improve single-plasmon detection and high-resolution characterization techniques for high quality plasmonic materials.Comment: 4 pages, 4 figures (excluding Supporting Information

Umbilicity and characterization of Pansu spheres in the Heisenberg group

For $n\geq 2$ we define a notion of umbilicity for hypersurfaces in the Heisenberg group $H_{n}$. We classify umbilic hypersurfaces in some cases, and prove that Pansu spheres are the only umbilic spheres with positive constant $p$(or horizontal)-mean curvature in $H_{n}$ up to Heisenberg translations.Comment: 32 pages, 2 figures; in Crelle's journal, 201