Effect of previous-winter mortality on the association between summer temperature and mortality in South Korea.

BACKGROUND: It has recently been postulated that low mortality levels in the previous winter may increase the proportion of vulnerable individuals in the pool of people at risk of heat-related death during the summer months. OBJECTIVES: We explored the sensitivity of heat-related mortality in summer (June-August) to mortality in the previous winter (December-February) in Seoul, Daegu, and Incheon in South Korea, from 1992 through 2007, excluding the summer of 1994. METHODS: Poisson regression models adapted for time-series data were used to estimate associations between a 1 °C increase in average summer temperature (on the same day and the previous day) above thresholds specific for city, age, and cause of death, and daily mortality counts. Effects were estimated separately for summers preceded by winters with low and high mortality, with adjustment for secular trends. RESULTS: Temperatures above city-specific thresholds were associated with increased mortality in all three cities. Associations were stronger in summers preceded by winters with low versus high mortality levels for all nonaccidental deaths and, to a lesser extent, among persons ≥ 65 years of age. Effect modification by previous-winter mortality was not evident when we restricted deaths to cardiovascular disease outcomes in Seoul. CONCLUSIONS: Our results suggest that low winter all-cause mortality leads to higher mortality during the next summer. Evidence of a relation between increased summer heat-related mortality and previous wintertime deaths has the potential to inform public health efforts to mitigate effects of hot weather

Developing a Discipleship-training Model for Equipping the Laity with both Emotional and Spiritual Maturity in Korean Churches

There are a lot of discipleship training programs in South Korea, but there is no discipleship-training program that focuses on both emotional maturity and spiritual maturity at the same time for mature believers. By focusing so much on spiritual maturity, churches have neglected the parts of emotional maturity since the churches were planted in South Korea. Emotionally unhealthy believers cause conflicts in church and struggle with serious individual troubles. Therefore, Korean churches should have a discipleship program which focuses on the emotional aspects as Jesus came to the earth as a perfect human and an incontestable God. The purpose of this thesis project is to provide a discipleship-training program focused on the emotional maturity. In order to attain this goal, this study will explore the necessity of the balanced discipleship-training program through the biblical and theological studies on discipleship training with emotional maturity. Also, this study will examine strengths and weaknesses of current discipleship models. This project will survey the laities, who are potential small group leaders, to examine their perception of emotional maturity. Finally, this project will provide an integrative discipleship-training model for both emotional maturity and spiritual maturity based on the results of the survey and the research

The Effects of Blade Fillets on Aerodynamic Performance of a High Pressure Ratio Centrifugal Compressor

In most cases of aerodynamic design of centrifugal compressors, the effects of impeller blade fillets on performance are not considered in the process, but could be estimated later from some limited studies. As one of numerical investigations for the effects in centrifugal compressors, the Krain backswept impeller was modeled with and without blade fillets on the hub. A vaneless diffuser and impeller tip clearances were included in the steady state analysis using a commercial CFD code. Over the range of flows at design speed, the case with blade fillets showed a slight drop in the pressure ratio, the efficiency, the choke flow and the range of operation, relative to the case of clean blades. A more detailed look into three-dimensional flow structure inside the impeller shows that a small scraping vortex, developed in the case of clean blades at the corner of the hub pressure surface, disappears in the case with blade fillets due to a local flow acceleration produced by the fillet. As a result of balancing forces acting in the impeller passage, it was observed that the shroud passage vortex in the case with blade fillets grows toward the impeller exit with a higher vortex core than that in the case of clean blades, which means that there are more wake flows with blade fillets, leading to aerodynamic performance drops

Realization of Negative Group Delay Network Using Defected Microstrip Structure

A design of negative group delay (NGD) networks using a U-shaped defected microstrip structure (DMS) and lumped elements is presented in this paper. The signal attenuation characteristics of DMS were utilized to get NGD time. The group delay (GD) time and signal attenuation of the proposed networks are controlled by an external resistor connected across the DMS slot. For experimental validation, a single-stage and cascaded two-stage NGD networks were designed and fabricated. From experimental results, the GD of -8.24±1.1 ns with the maximum insertion loss of 37.84 dB was obtained over bandwidth of 40 MHz

Comparative Genomic and Phylogenomic Analyses Clarify Relationships Within and Between Bacillus cereus and Bacillus thuringiensis: Proposal for the Recognition of Two Bacillus thuringiensis Genomovars

The present study was designed to clarify the taxonomic status of two species classified as Bacillus cereus sensu lato, namely B. cereus sensu stricto and Bacillus thuringiensis. To this end, nearly 900 whole genome sequences of strains assigned to these taxa were the subject of comparative genomic and phylogenomic analyses. A phylogenomic tree based on core gene sequences showed that the type strains of B. cereus and B. thuringiensis formed a well-supported monophyletic clade that was clearly separated from corresponding clades composed of the remaining validly published species classified as B. cereus sensu lato. However, since average nucleotide identity and digital DNA-DNA hybridization similarities between the two types of Bacillus were slightly higher than the thresholds used to distinguish between closely related species we conclude that B. cereus and B. thuringiensis should continue to be recognized as validly published species. The B. thuringiensis strains were assigned to two genomically distinct groups, we propose that these taxa be recognized as genomovars, that is, as B. thuringiensis gv. thuringiensis and B. thuringiensis gv. cytolyticus. The extensive comparative genomic data clearly show that the distribution of pesticidal genes is irregular as strains identified as B. thuringiensis were assigned to several polyphyletic groups/subclades within the B. cereus-B. thuringiensis clade. Consequently, we recommend that genomic or equivalent molecular systematic features should be used to identify B. thuringiensis strains as the presence of pesticidal genes cannot be used as a diagnostic marker for this species. Comparative taxonomic studies are needed to find phenotypic properties that can be used to distinguish between the B. thuringiensis genomovars and between them and B. cereus.

Nanostructured thin films for solid oxide fuel cells

The goals of this work were to synthesize high performance perovskite based thin film solid oxide fuel cell (TF-SOFC) cathodes by pulsed laser deposition (PLD), to study the structural, electrical and electrochemical properties of these cathodes and to establish structure-property relations for these cathodes in order to further improve their properties and design new structures. Nanostructured cathode thin films with vertically-aligned nanopores (VANP) were processed using PLD. These VANP structures enhance the oxygen-gas phase diffusivity, thus improve the overall TF-SOFC performance. La0.5Sr0.5CoO3 (LSCO) and La0.4Sr0.6Co0.8Fe0.2O3 (LSCFO) were deposited on various substrates (YSZ, Si and pressed Ce0.9Gd0.1O1.95 (CGO) disks). Microstructures and properties of the nanostructured cathodes were characterized by transmission electron microscope (TEM), high resolution TEM (HRTEM), scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS) measurements. A thin layer of vertically-aligned nanocomposite (VAN) structure was deposited in between the CGO electrolyte and the thin film LSCO cathode layer for TF-SOFCs. The VAN structure consists of the electrolyte and the cathode materials in the composition of (CGO) 0.5 (LSCO) 0.5. The self-assembled VAN nanostructures contain highly ordered alternating vertical columns formed through a one-step thin film deposition using a PLD technique. These VAN structures significantly increase the interface area between the electrolyte and the cathode as well as the area of active triple phase boundary (TPB), thus improving the overall TF-SOFC performance at low temperatures, as low as 400oC, demonstrated by EIS measurements. In addition, the binary VAN interlayer could act as the transition layer that improves the adhesion and relieves the thermal stress and lattice strain between the cathode and the electrolyte. The microstructural properties and growth mechanisms of CGO thin film prepared by PLD technique were investigated. Thin film CGO electrolytes with different grain sizes and crystal structures were prepared on single crystal YSZ substrates under different deposition conditions. The effect of the deposition conditions such as substrate temperature and laser ablation energy on the microstructural properties of these films are examined using XRD, TEM, SEM, and optical microscope. CGO thin film deposited above 500 ºC starts to show epitaxial growth on YSZ substrates. The present study suggests that substrate temperature significantly influences the microstructure of the films especially film grain size

The analysis of oral microbial communities of wild-type and toll-like receptor 2-deficient mice using a 454 GS FLX Titanium pyrosequencer

Background: Although mice have long served as an animal model for periodontitis, information on the composition of their indigenous oral microbiota is limited. The aim of the current study was to characterize mouse oral bacterial flora by applying extensive parallel pyrosequencing using the latest model pyrosequencer, a Roche/454 Genome Sequencer FLX Titanium. In addition, the effect of Toll-like receptor (TLR) 2 deficiency on oral microbiota was evaluated. Results: Eight oral bacterial communities of wild-type (n = 4) and TLR2 knock-out (n = 4) C57BL/6 mice were characterized by analyzing 80,046 reads of 16S rRNA genes obtained by pyrosequencing. Excluding the PCR primers, the average length of each sequencing product was 443 bp. The average species richness of the murine oral bacterial communities was estimated to be about 200, but the communities were dominated by only two main phyla and several species. Therefore, the bacterial communities were relatively simple. The bacterial composition of the murine oral microbiota was significantly different from that of humans, and the lack of TLR2 had a negligible effect on the murine oral microbiota. Conclusion: Pyrosequencing using the Roche/454 FLX Titanium successfully characterized mouse oral bacterial communities. The relatively simple oral bacterial communities of mice were not affected by TLR2 deficiency. These findings will provide a basis for future studies on the role of periodontal pathogens in the murine model of periodontitis.This study was supported by grants R13-2008-008-01003-0 from the Korea Science and Engineering Foundation.

Exploring the impact of functional, symbolic, and experiential image on approach behaviors among state-park tourists from India, Korea, and the USA

This study provides insights into the influence of state park image, visitor emotions, and place identity on visitors’ revisit intentions by considering the moderating impact of national culture. A quantitative process with the data collected in India, Korea, and the US was used. Hierarchical regression analysis evidences the moderating role of national culture, which is hardly explored in the state park context. Results confirm that most hypotheses are fully or partially accepted, which suggests that brand image and national culture influence visitor intention. This study helps practitioners better understand the relevance of national culture in developing appropriate visitor attraction/retention strategies

A General Performance Model for Design-Build Highway Pavement

New challenges are revealed as more projects are delivered and contracted through innovative methods such as design-build project delivery and performance-based specifications. One challenge from the owner's perspective is lack of control, especially over design decisions and construction procedures. Due to this problem, highway agencies have adopted various additional contractual provisions, of which one is warranty. Warranty is intended to be a method of protecting the owner from possible quality defects and also of improving the initial and long-term performance of the facility.The research question is how warranty characteristics (i.e., warranty period) and other project characteristics impact the performance of highway pavement projects. To answer this question, a decision model was developed to simulate warranty impacts on project performance. Also, simulations were run to estimate the outcomes of projects with varying scope, contracting, and delivery methods in order to examine the impact of project characteristics on warranty decisions and project outcomes.A probabilistic decision-modeling technique, General Performance Model (GPM), is adopted for this warranty decision model. GPM is one method that is being used widely and has been proven to work for both alternative comparison and selection decision. Since GPM has been developed specifically for the purpose of comparing probable performance outcomes for various decision alternatives, it fits the purpose of this research.According to the simulation results, the contract price tends to increase as the warranty period becomes longer and higher-level performance is required. On the other hand, the agency's expected maintenance and repair costs tend to become less with longer and stricter warranty. Where the life-cycle cost (LCC) of a facility is concerned, the simulation shows that warranty is more beneficial for projects with certain characteristics such as sufficient contractor control, innovation opportunity, design-build delivery method, and performance-based specifications. The results of sensitivity analysis show that warranty period and required-performance level influence project outcomes significantly. Among intermediate factors, amount of warranty risk, motivation for quality improvement, and innovation effort were found to be more sensitive than others.A model is constructed to represent some aspects of the dynamic behavior of a real system. Therefore, a properly developed model can serve as a tool for investigating the behavior of the system and predict future outcomes with reasonable enough accuracy. In order to check the validity of the model, the process of requisite-model validation was applied, and a number of checkpoints were examined through expert interviews.Because of the representative nature of the model, a few assumptions had to be made. Also, the model has some limitations due to its method and scope. First, the project outcomes are measured in the form of life-cycle-cost (LCC) only. The performance measures other than LCC are not considered in the model. Also, the timing of warranty decision is limited to after-project development and prior bidding. Warranty decisions at different times, such as warranty option, which is practiced after construction, are not considered in this model. Finally, the model is limited to asphalt highway pavement projects. Although warranties are often used in other types of projects, such as concrete pavement, bridges, and ITS, they were not considered in this research. The model could be expanded to cover a wider range of project types, decision timing and performance measures in future research