1,758 research outputs found

    Influential factors in the out-of-class activities of Korean college students

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    This study aimed to explore who participates in what kinds of out-of-class activities in Korea\u27s universities. Therefore, the researchers examine whether differences exist in the pattern of out-of-class experiences according to the individual characteristics of the students, including gender, grade, household income level, high school performance and major. The researchers also aimed to examine the empirical evidence to determine the relationships between the patterns in out-of-class activities and the institutional characteristics of the university that the student attends. In terms of the institutional characteristics, this study is concerned with the location and size of the university. To explore these questions, the researchers analyzed K-NSSE data with hierarchical linear modeling. In sum, the findings of the statistical analysis of this study support the results of the preceding research in which different personal and institutional characteristics are related to five types of out-of-class activities. (DIPF/Orig.

    The relationship between participation in out-of-class activities and cognitive and social outcomes of Korean college students

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    In the era of the 4th Industrial Revolution, higher education institutions should change practices of educational programs and services, which are mainly based on traditional classroom-based instructions, to allow students to have more diverse experiences. Since college students spend relatively more time engaged in out-of-class activities than attending regular courses, it is necessary to examine how participating in out-of-class programs is related to cultivation of the competencies that the future demands. This study explores the relationship between out-of-class activity participation and perceived change in cognitive and social outcomes of Korean college students. Five out-of-class activities were examined: learning community, undergraduate research, service learning, internship, and residential college programs. K-NSSE (Korea-National Survey of Student Engagement) data were analyzed using hierarchical linear model analysis. The study findings are consistent with the results of previous research that demonstrated a positive association between participating in out-of-class activities and students\u27 cognitive and social outcomes. (DIPF/Orig.

    Global gene-expression profiles of intracellular survival of the BruAb2_1031 gene mutated Brucella abortus in professional phagocytes, RAW 264.7 cells

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    Background Since recognizing the interaction between Brucella and host cells is crucial to the elucidation of the infectious process, Brucella researches have prioritized the investigation of genes related to pathogenicity. To demonstrate the roles of Brucella genes, RAW 264.7 cells were infected with the Brucella abortus wild-type and mutant strains (generated using transposon mutagenesis), after which the different transcriptional responses of the infected cells were determined using microarray. Results Following infection, enhanced strategies for intracellular survival, such as down-regulation of genes associated with cytokine responses and apoptosis, were observed in RAW 264.7 cells infected with C3 mutant strain when compared to the transcriptional responses of wild-type infected cells. Using sequence analysis, we determined the mutation site of a C3 mutant strain as the ATP-binding cassette transporter permease (BruAb2_1031). These results were evidenced by an increased level of intracellular survival of the C3 mutant strain. Conclusions Characteristics of each mutant strain including bacterial growth rate, abilities to induce cytokine production in macrophages after infection, internalization, and levels of intracellular survival and replication, were investigated by performing RAW 264.7 cell infection experiments. Our results indicate that the BruAb2_1031 gene might be closely related with intracellular survival of B. abortus in RAW 264.7 cells.This work was supported by NRF grant of MSIP (No. 2014R1A2A2A01007291), Korea Health Industry Development Institute (HI16C2130), BK21 PLUS and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea. The funders had no role in study design, data collection and interpretation, writing the manuscript and the decision to submit the work for publication

    Mapping 49 quantitative trait loci at high resolution through sequencing-based genotyping of rice recombinant inbred lines

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    Mapping chromosome regions responsible for quantitative phenotypic variation in recombinant populations provides an effective means to characterize the genetic basis of complex traits. We conducted a quantitative trait loci (QTL) analysis of 150 rice recombinant inbred lines (RILs) derived from a cross between two cultivars, Oryza sativa ssp. indica cv. 93-11 and Oryza sativa ssp. japonica cv. Nipponbare. The RILs were genotyped through next-generation sequencing, which accurately determined the recombination breakpoints and provided a new type of genetic markers, recombination bins, for QTL analysis. We detected 49 QTL with phenotypic effect ranging from 3.2 to 46.0% for 14 agronomics traits. Five QTL of relatively large effect (14.6–46.0%) were located on small genomic regions, where strong candidate genes were found. The analysis using sequencing-based genotyping thus offers a powerful solution to map QTL with high resolution. Moreover, the RILs developed in this study serve as an excellent system for mapping and studying genetic basis of agricultural and biological traits of rice. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00122-010-1449-8) contains supplementary material, which is available to authorized users

    Uncertainty-reduction or reciprocity? Understanding the effects of a platform-initiated reviewer incentive program on regular review generation

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    To stimulate product reviews, many e-commerce platforms have launched reviewer incentive programs in which free product samples are provided to reviewers in exchange for their ratings of the samples. This study focuses on an unexplored aspect of reviewer incentive programs—the impact of participating in such programs on reviewers’ ratings of products they purchased normally (i.e., regular ratings). We find that after reviewers join the program and receive free product samples, their average regular rating increases by 2.25% (i.e., 0.093 more stars on the five-star scale). Our follow-up analyses indicate that the observed regular-rating increase can be attributed to an uncertainty-reduction effect evoked by the free product samples, as opposed to a reciprocity effect. We further delve into the underlying mechanism by analyzing the reviewers’ regular ratings at a granular, product-category level. Consistent with our theorization of the uncertainty-reduction effect, our findings reveal that reviewers’ regular-rating increase is driven by improved assessment and knowledge about products sharing common attributes with the sampled products, resulting in better post-purchase outcomes. Our results demonstrate that apart from motivating the feedback for the sampled products, free product sampling can reduce reviewers’ product uncertainty and trigger evident change in their regular ratings for the purchased products.First author draf

    Enzymatic analysis of the effect of naturally occurring Leu138Pro mutation identified in SHV β-lactamase on hydrolysis of penicillin and ampicillin

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to analyze the significance of leucine to proline substitution at position 138(Leu138Pro) on the hydrolysis of penicillin and ampicillin that we identified in the <it>bla</it><sub>SHV </sub>gene of clinical <it>Escherichia coli </it>swine isolate.</p> <p>Results</p> <p>Kinetic analysis of the mutant proteins showed that <it>K</it><sub><it>m </it></sub>value of the purified L138P mutant was comparatively higher than SHV-1, SHV-33 and SHV-33(L138P) enzyme for penicillin and ampicillin. Docking simulation of the SHV-1 and SHV-(L138P) enzymes also confirmed that β-lactamases preferred penicillin to ampicillin and the SHV-1 had a higher binding affinity for antibiotics compared to the SHV-(L138P) and other mutants.</p> <p>Conclusions</p> <p>Our result demonstrated that L138P has a reduced role in penicillin and ampicillin hydrolyzing properties of SHV β-lactamases. These naturally occurring mutations rendering reduced function of the existing protein could trigger the emergence or acquisition of more effective alternative mechanisms for β-lactam hydrolysis.</p

    Combination of Dexmedetomidine and Ketamine for Magnetic Resonance Imaging Sedation

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    Objectives: The use of dexmedetomidine and ketamine (DEX–KET) combination for magnetic resonance imaging (MRI) sedation has not been evaluated. We investigated the efficacy and safety of DEX–KET for sedation of patients undergoing MRI of the brain.Methods: This quasi-experimental study was conducted to compare the DEX–KET combination and midazolam for MRI sedation. We included 72 patients undergoing brain MRI following bolus injection of midazolam or DEX–KET. In August 1, 2016 a new MRI sedation protocol was implemented. After protocol implementation, bolus doses of DEX–KET were administered (DEX–KET group). Thirty-six patients from the MIDA group and 36 patients from the DEX–KET group underwent MRI sequences and were compared regarding the MRI scan time and sedation-related complications (desaturation, hypotension, cardiorespiratory arrest, and aspiration pneumonia).Results: All MRI sequences were completed for 30 patients (83.3%) from the MIDA group and for 33 patients (91.7%) from the DEX–KET group (P = 0.476). The median MRI scan time was 100.0 min (interquartile range, 87.0–111.5 min) in the MIDA group and 53.5 min (interquartile range, 45.0–60.5 min) in the DEX–KET group (P &lt; 0.001). Complications occurred in 24 (66.7%) and 8 (22.2%) patients of the MIDA and DEX–KET group, respectively (P &lt; 0.001).Conclusions: The efficacy of DEX–KET sedation was comparable to that of midazolam for MRI examination. DEX–KET was related to shorter scan time and lower occurrence of complications compared to midazolam

    Multilayered Composites with Modulus Gradient for Enhanced Pressure???Temperature Sensing Performance

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    Highly sensitive and flexible composite sensors with pressure and temperature sensing abilities are of great importance in human motion monitoring, robotic skins, and automobile seats when checking the boarding status. Several studies have been conducted to improve the temperature-pressure sensitivity; however, they require a complex fabrication process for micro-nanostructures, which are material-dependent. Therefore, there is a need to develop the structural designs to improve the sensing abilities. Herein, we demonstrate a flexible composite with an enhanced pressure and temperature sensing performance. Its structural design consists of a multilayered composite construction with an elastic modulus gradient. Controlled stress concentration and distribution induced by a micropatterned structure between the layers improves its pressure and temperature sensing performance. The proposed composite sensor can monitor a wide range of pressure and temperature stimuli and also has potential applications as an automotive seat sensor for simultaneous human temperature detection and occupant weight sensing
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