The story of my learning as a learner as a teacher

The presenter will share her experience as a non-native graduate student in the US. She and the participants will consider the challenges that international graduate students face. This workshop will give the participants a chance to think about how to help international students overcome their difficulties

Lactobacillus sakei suppresses collagen-induced arthritis and modulates the differentiation of T helper 17 cells and regulatory B cells

Abstract Background To evaluate the immunomodulatory effect of Lactobacillus sakei in a mouse model of rheumatoid arthritis (RA) and in human immune cells. Methods We evaluated whether L. sakei reduced the severity of collagen-induced arthritis (CIA) and modulated interleukin (IL)-17 and IL-10 levels, as well as whether it affected the differentiation of CD4+ T cells and regulatory B cells. We evaluated osteoclastogenesis after culturing bone marrow-derived mononuclear cells with L. sakei. Results The differentiation of T helper 17 cells and the serum level of IL-17 were suppressed by L. sakei in both human peripheral blood mononuclear cells and mouse splenocytes. The serum level of IL-10 was significantly increased in the L. sakei-treated group, whereas the regulatory T cell population was unchanged. The population of regulatory B cells significantly increased the in L. sakei-treated group. Oral administration of L. sakei reduced the arthritis incidence and score in mice with CIA. Finally, osteoclastogenesis and the mRNA levels of osteoclast-related genes were suppressed in the L. sakei-treated group. Conclusion L. sakei exerted an anti-inflammatory effect in an animal model of RA, regulated Th17 and regulatory B cell differentiation, and suppressed osteoclastogenesis. Our findings suggest that L. sakei has therapeutic potential for RA

Nitrogen and Sulfur Co-Doped Porous Carbon Derived from Thiourea and Calcium Citrate for Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries have shown a high theoretical specific capacity of 1675 mAh g−1. However, amongst the issues they have, the low electron conductivity of sulfur and its dissolution represent the biggest challenge limiting its practical applications. This contributes to the low utilization of the active sulfur at the cathode—a phenomenon known as the “shuttling effect.” To overcome these limitations, some strategies such as physical confinement (sulfur–carbon composite), chemical adsorption (N and/or S doping) electrolyte design, and separator design have already been proposed. Calcium citrate is the most attractive carbon source because no activation process is necessary and the fabrication process is very simple. In this experiment, we synthesized calcium citrate and sulfur (S) to conduct a charging–discharging test and compared them by adding thiourea (TU) as well as S in the carbonized calcium citrate (CaC). This effective and simple technique for material production can accommodate the charge/discharge reactions and preserve the structure over long cycles. A CaC/TU-S composite is acceptable for an initial discharge capacity of 1051.6 mAh g−1 over 100 cycles at 1 C. The results show that the CaC-S and CaC/TU-S composites have a good, stable specific capacity

교정

Asynchronous ranging is one practical method to implement a locating system that provides accurate results. However, a locating system utilizing asynchronous ranging generates a large number of messages that cause transmission delays or failures and degrades the system performance. This paper proposes a novel approach for efficient congestion control in an asynchronous rangebased locating system. The proposed method significantly reduces the number of messages generated during the reader discovery phase by eavesdropping on other transmissions and improves the efficiency of ranging by organizing the tags in a hierarchical fashion in the measurement phase. Our evaluation shows that the proposed method reduces the number of messages by 70% compared to the conventional method and significantly improves the success rate of ranging

Microsoft Word - 20120706_revised_hoonchoi.docx

An asynchronous ranging is one practical method to implement a locating system that provides accurate results. However, a locating system utilizing asynchronous ranging generates a large number of messages that cause transmission delays or failures, and degrades the system performance. This paper proposes a novel approach for efficient congestion control in asynchronous range based locating system. The proposed method significantly reduces the number of messages generated during the Reader Discovery phase by eavesdropping on other transmissions, and also improves the efficiency of ranging by organizing the tags in a hierarchical fashion in the Measurement phase. Our evaluation shows that the proposed method reduces the number of messages by 70% compared to the conventional method and significantly improves the success rate of ranging

Revising the Scope of Linguistic Relativity: Language Influences Perception in Non-linguistic Tasks

According to linguistic relativity, the structure of a language influences its speaker’s cognition. To examine the generalization to non-linguistic tasks, we compared Korean and German native speakers. In Korean, a grammatical distinction forces to discriminate between tight and loose spatial relations, while in German, this falls into one single semantic category. In visual priming and masking experiments, we found 1) direct and 2) indirect evidence for linguistic relativity. 1) Congruence effects in the discrimination of tight/loose spatial relations only for Korean speakers and 2) a reduced efficiency of metacontrast masking (which relies on spatial fit between stimulus and mask) for Korean speakers, as attention was automatically captured by varying distances, according to their grammar. With object-substitution masks (where tightness of fit does not play a role), Korean speakers no longer outperformed German speakers. In our study, the highly practiced characteristics of one’s mother tongue affected attention and, hence, perception

Molecular guest exchange and subsequent structural transformation in CH4-CO2 replacement occurring in sH hydrates as revealed by 13C NMR spectroscopy and molecular dynamic simulations

This study adopted experimental and computational approaches to investigate CH4 - CO2 replacement in the structure H (sH) CH4 + methylcyclopentane (MCP) hydrate for its dual functions of CH4 recovery and CO2 sequestration. Hydrate phase equilibria, 13C NMR spectra, and molecular dynamics (MD) simulations of CH4 + MCP - CO2 replacement were examined and compared with those of CH4 + neohexane (NH) - CO2 replacement to elucidate the molecular guest exchange behaviors in both systems. The structure I (sI) hydrates were ther-modynamically favored in CO2-rich gas mixtures (CH4 + CO2 + MCP systems), and a structural transformation from sH to sI occurred when CO2 composition in the feed gas was higher than 20 %. The 13C NMR spectra indicated that the CO2 molecules preferred to occupy the large (51262) cages of sI and the medium (435663) cages of sH compared to the small (512) cages of both sI and sH during replacement. Following CO2 injection into the sH CH4 + MCP hydrate, the initial sH hydrate transformed to the sI hydrate with CH4 recovery of approximately 78 %. The MD simulations also demonstrated that structural transformation in the CH4 + MCP - CO2 replace-ment would occur at the lower CO2 enclathration ratio compared to the CH4 + NH - CO2 replacement, thereby leading to a lower CO2 concentration in the newly formed sI hydrate. This is the first study to provide both experimental and computational evidence of guest-dependent structural transformation in sH CH4 + liquid hydrocarbons - CO2 replacement

Effect of polydopamine surface coating on polyethylene separators as a function of their porosity for high-power Li-ion batteries

This study demonstrates the effect of polydopamine coating on separator membranes used in liquid electrolyte batteries as a function of membrane porosity. We select two typical separators that differed only in porosity. High-porosity (16H) and low-porosity (16L) separators are coated with polydopamine by simple dip-coating. Their properties are evaluated via scanning electronic microscopy (SEM) and determining the water contact angle, Gurley number, ionic conductivity, and uptake volume of liquid electrolyte. In addition, the effect of polydopamine coating on electrochemical properties is tested using CR2032 coin-type half-cells (LiMn2O4/Li metal). With enhanced hydrophilic properties of surfaces as keeping pore structures, both of polydopamine coated high and low porous separators show enhanced rate capability and cell performance compared to uncoated versions. The effect of polydopamine coating is greatly enhanced in the low-porosity separators, with up to 40% increase in power capability (at 5 C rate) and a 290% increase in cycle performance (after 500 cycles, at C/2 rate), compared to the high-porosity type (13% increase in power capability, 43% increase in cycle performance).(C) 2013 Elsevier Ltd. All rights reserved.