Dual condensates at finite isospin chemical potential

The dual observables as order parameters for center symmetry are tested at finite isospin chemical potential $\mu_I$ in a Polyakov-loop enhanced chiral model of QCD with physical quark masses. As a counterpart of the dressed Polyakov-loop, the first Fourier moment of pion condensate is introduced for $\mu_I>{m_\pi}/{2}$ under the temporal twisted boundary conditions for quarks. We demonstrate that this dual condensate exhibits the similar temperature dependence as the conventional Polyakov-loop. We confirm that its rapid increase with $T$ is driven by the evaporating of pion condensation. On the other hand, the dressed Polyakov-loop shows abnormal thermal behavior, which even decreases with $T$ at low temperatures due to the influence of pion condensate. We thus argue that in QCD the critical temperature extracting from a dual observable may have nothing to do with the quark confinement-deconfinement transition if the quark mass is very small.Comment: 8 pages, 6 figure

Towards an exact treatment of exchange and correlation in materials: Application to the "CO adsorption puzzle" and other systems

It is shown that the errors of present-day exchange-correlation (xc) functionals are rather short ranged. For extended systems the correction can therefore be evaluated by analyzing properly chosen clusters and employing highest-quality quantum chemistry methods. The xc correction rapidly approaches a universal dependence with cluster size. The method is applicable to bulk systems as well as to defects in the bulk and at surfaces. It is demonstrated here for CO adsorption at transition-metal surfaces, where present-day xc functionals dramatically fail to predict the correct adsorption site, and for the crystal bulk cohesive energy.Comment: slightly revised version: 4 pages including 3 figures; related publications can be found at http://www.fhi-berlin.mpg.de/th/th.htm

A Genome-Wide Characterization of Differentially Expressed Genes Encoding mRNAs and miRNAs and Methylation Analysis of Phytochrome Genes in a Cotton Phytochrome A1 RNAi line

Silencing phytochrome A1 gene (PHYA1) by RNA interference in upland cotton (Gossypium hirsutum L. cv. Coker 312) had generated PHYA1 RNAi lines with increased fiber length, strength and low micronair (finer fiber). In order to identify and characterize mRNAs and miRNAs that are differentially expressed in the RNAi plants, transcriptome and miRNAome analyses via high-throughput RNA sequencing were performed. Total RNA isolated from 10-DPA (days post anthesis) fibers and small RNAs isolated from 5-, 10-, and 15-DPA fibers of RNAi and Coker 312 lines were used to construct 6 RNA libraries and 18 small RNA libraries, respectively, which were sequenced using the Illumina HiSeq system. A total of 142 differentially expressed genes (DEGs) were identified in PHYA1 RNAi compared to Coker 312. GO analysis showed that these DEGs were mainly involved in metabolic pathways, binding and regulating enzymes (hydrolase, transferase, and oxidoreductase activities), and cell structures which were reported to play important roles in fiber development. Twenty-eight KEGG pathways were mapped for 142 DEGs, and the pathways related to glycolysis/gluconeogenesis and pyruvate metabolism were the most abundant, followed by cytochrome P450-involved pathways. Sixty-one conserved miRNA families and thirtyive novel miRNAs were identified in upland cotton. The targets of 6 conserved miRNAs, which expressed differentially in the RNAi line, were reported to participate in primary cell wall synthesis and phytohormone signaling pathways. The 35 novel miRNAs were identified in cotton for the first time, and their target genes were predicted. Nine novel miRNAs were identified to target cytochrome P450 TBP. Together, the results imply that miRNAs involved in fine-tune gene regulation might confer to the phenotype of the RNAi line with improved fiber quality. Besides characterizing mRNAs and miRNAs, the CpG site methylation status within coding regions of phytochrome genes in RNAi line in leaves and 10-DPA fibers was determined using bisulfite genomic sequencing. The PHYA1, PHYC and PHYE in RNAi line had higher methylation levels in leaves than those in Coker 312, but PHYB had lower methylation levels. In fibers, the methylation levels of PHYB also decreased in RNAi plants. However, the methylation of other phytochrome genes showed no significant changes

Measuring the Value of Time in Highway Freight Transportation

This research investigated several aspects of the value of time (VOT) in the trucking industry. This included examining the marginal monetary benefits and costs of reduced and prolonged freight transportation time on highways. First, a comprehensive survey estimated truckers’ perceived VOT by combining stated preference, utility theory, conditional logit modeling, and maximum likelihood function. From the data collected around major cities in Texas and Wisconsin, the truckers’ perceived VOT was estimated to be $54.98/vehicle/hour. Second, scenario-based simulation examined urban truckload operations, the purpose of which was to examine the fleet effect of individual vehicle delay on the carrier’s operation. Two of the most congested highway segments in Houston were used for the simulation, together with constrained delivery windows. The result showed that the scenario-based vehicle VOT varied from$79.81/vehicle/hour to $120.89/vehicle/hour. Third, VOT based on commodity delay only was examined in relationship to inventory management by assuming prolonged transportation time or freight delay. Delay of chemical products was ranked as the highest VOT at$13.89/truckload/hour, followed by food products at $7.24/truckload/hour. Finally, a continuous approximation technique was developed for fleet operations in the context of less-than-truckload deliveries. The trade-offs between travel time and roadway transportation cost were derived analytically and results were used to estimate fleet value of time. Ignoring time windows, the vehicle VOT for major distribution companies in Texas was estimated to be$15.50/vehicle/hour for highway trips and $22.00/vehicle/hour for local trips. To summarize, freight VOT is not only directly due to vehicles and drivers, but depends on fleet operations and supply chain management. The several approaches adopted in this research represent possible perspectives that need to be further examined. They each reveal a component of the entire shipping process that can be appropriately utilized to calculate the overall freight VOT in future studies. For example, an urgent delivery carrying chemical products can be estimated at a total congestion cost of$162.86/vehicle/hour. However, trips with different characteristics need to be treated individually andcarefully to avoid overestimation. It remains challenging tocombineall these different elements adequately to reach valid VOT for the trucking industry

Eigenvalues for a Neumann Boundary Problem Involving the p

We study the existence of weak solutions to the following Neumann problem involving the p(x)-Laplacian operator:  -Δp(x)u+e(x)|u|p(x)-2u=λa(x)f(u), in  Ω, ∂u/∂ν=0, on  ∂Ω. Under some appropriate conditions on the functions p,  e,  a, and  f, we prove that there exists λ¯>0 such that any λ∈(0,λ¯) is an eigenvalue of the above problem. Our analysis mainly relies on variational arguments based on Ekeland’s variational principle

CLIMATE CHANGE ADAPTATION, NATURAL HAZARD MITIGATION, AND INNOVATIVE RESPONSES

This dissertation is comprised of three essays which examine innovation, both technological and institutional, as a response aimed to adapting to climate change and natural disasters. Specifically, the first two papers seek to understand the drivers and implications of adaptation-related technological innovations. The third paper draws on the policy innovation theory to examine factors that shape the decision of state governments to engage in comprehensive climate adaptation planning. In Chapter 1, I examine the drivers of technical innovation as an important form of adaptation by investigating the impact of three types of natural disasters—floods, droughts and earthquakes—on the patenting activities of their respective mitigation technologies. Using patent and disaster damage data, this study is the first to empirically examine adaptation responses across multiple sectors at the country level. My empirical analysis, using a panel of 28 countries over a period of 25 years, shows that a country’s risk-mitigating innovations increase significantly with the severity of disasters it has recently experienced, while the degree of impact varies across different types of disasters and technologies. In Chapter 2, I evaluate the effectiveness of the risk-mitigating innovations in reducing disaster impacts in the case of earthquakes. By conceptualizing adaptation as a learning process, I examine the effect of technical knowledge stocks, constructed by patent counts in quake-proof building technologies, and informal knowledge, measured by prior earthquake experiences, on reducing earthquake-related losses. Using a global cross section, I find that countries with more earthquake-mitigation technical innovations and more earthquake exposure in the past suffer fewer fatalities. This “learning-by-doing” effect is much larger in high-income countries, which suggests their stronger adaptive capacity. Finally, Chapter 3 focuses on climate adaptation planning in the U.S. by examining the factors that drive state governments to develop comprehensive adaptation plans. I use an event history analysis to examine both internal factors (states’ climate risks, adaptive capacity and political interests in climate change) and policy diffusion among states within the same climate regions. This study finds that the state-level adaptation decision is highly driven by the extreme weather events the state has recently experienced, and also associated with the state’s potential exposure to climate risks, income level, civic engagement and environmental preferences. By examining the motivation for and barriers to subnational adaptation responses, this research has important implications for environmental federalism and governance. From the innovation perspective, my dissertation contributes to a deeper understanding of adaptation as a dynamic social-learning process, and sheds light on what drives society to adapt to environmental changes and shocks. It also informs an integrated policy approach to facilitating efficient climate adaptation and natural hazard mitigation