Korean EFL Learners Metadiscourse Use as an Index of L2 Writing Proficiency

The current research investigated the correlation between L2 writing proficiency and metadiscourse use in argumentative texts. Metadiscourse is recognized as one of the key strategies for building interaction between a writer and an audience in written discourse. In order to explore the effect of proficiency on the use of metadiscourse markers, the study analyzed two corpora of argumentative essays written by three different proficiency groups of Korean EFL learners and native speakers of English. The focus of analysis was the frequency and range of two main subcategories of metadiscourse, i.e., interactive and interactional resources. The findings revealed marked variations in both quantitative and qualitative aspects of metadiscourse use across different proficiency levels. As proficiency develops, writers showed less reliance on the interactive resources, more balanced use of interactional resources (i.e., hedges and boosters), and expansion in the range of metadiscourse markers used. The findings provide some useful insights into teaching and learning of metadiscourse in persuasive writing which serve to increase a dialogic sense of interaction and audience involvement

MicroRNA clustering on the biogenesis of suboptimal microRNAs

Most microRNAs (miRNAs) are processed by two ribonuclease III enzymes. The first cleavage is performed by Microprocessor that is composed of RNase III enzyme Drosha and DGCR8, and the second by another RNase III enzyme Dicer. There are many examples of miRNAs that are poor substrates for Drosha and Dicer, owing to their suboptimal structures. However, a number of these suboptimal miRNAs are known to be expressed at the same or higher level as their neighboring structurally-optimal miRNAs. Recent studies suggest that the clustered orientation of these suboptimal miRNAs is the explanation for this phenomenon. It has been observed that the biogenesis of these suboptimal miRNAs can be affected by the expression of their neighboring optimal miRNAs. This principle is expected to apply more broadly, as it has been shown that a large percentage of suboptimal miRNAs reside within operons.This work was supported by Cooperative Research Program for Agriculture Science and Technology Development (Project No. PJ01577601) Rural Development Administration, Republic of Korea. This work was also supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2021R1A5A1032428)

A preliminary assessment of the wildlife trade in badgers (Meles leucurus and Arctonyx spp.) (Carnivora: Mustelidae) in South Korea

We provide a preliminary assessment of a previously overlooked wildlife trade, the legal trade in badgers (Meles leucurus and Arctonyx spp.) and badger-derived products in South Korea. A new phase of the trade emerged in the 1990s with the establishment of wildlife farms to supply demand for badger as an edible and medicinal resource, including as a substitute for Asiatic black bear (Ursus thibetanus), a CITES Appendix I species. We trace the continued existence of badger farms to supply trade between 2001-2020, supplemented by imported badger-derived products and some apparent illegal harvesting of wild Meles leucurus in South Korea. The range of badger-derived products available to consumers has diversified during the last two decades and now encompasses human food, traditional medicine, cosmetics, dietary supplements and accessories. We recommend improved monitoring and regulation of the trade, given that legal farming, and potential illegal wild harvest, may present important risks to: (i) wild Meles leucurus populations in South Korea and Arctonyx spp. populations in Asia, which are currently poorly monitored; (ii) the welfare of traded badgers, as territorial mammals with specific social and housing needs; (iii) human health, with mustelid farms now in greater focus as potential sources of novel zoonotic diseases

Effects of HA and NA glycosylation pattern changes on the transmission of avian influenza A(H7N9) virus in guinea pigs

AbstractAvian influenza H7N9 virus has posed a concern of potential human-to-human transmission by resulting in seasonal virus-like human infection cases. To address the issue of sustained human infection with the H7N9 virus, here we investigated the effects of hemagglutinin (HA) and neuraminidase (NA) N-linked glycosylation (NLG) patterns on influenza virus transmission in a guinea pig model. Based on the NLG signatures identified in the HA and NA genetic sequences of H7N9 viruses, we generated NLG mutant viruses using either HA or NA gene of a H7N9 virus, A/Anhui/01/2013, by reverse genetics on the 2009 pandemic H1N1 virus backbone. For the H7 HA NLG mutant viruses, NLG pattern changes appeared to reduce viral transmissibility in guinea pigs. Intriguingly, however, the NLG changes in the N9 NA protein, such as a removal from residue 42 or 66 or an addition at residue 266, increased transmissibility of the mutant viruses by more than 33%, 50%, and 16%, respectively, compared with a parental N9 virus. Given the effects of HA-NA NLG changes with regard to viral transmission, we then generated the HA-NA NLG mutant viruses harboring the H7 HA of double NLG addition and the N9 NA of various NLG patterns. As seen in the HA NLG mutants above, the double NLG-added H7 HA decreased viral transmissibility. However, when the NA NLG changes occurred by a removal of residue 66 and an addition at 266 were additionally accompanied, the HA-NA NLG mutant virus recovered the transmissibility of its parental virus. These demonstrate the effects of specific HA-NA NLG changes on the H7N9 virus transmission by highlighting the importance of a HA-NA functional balance

Cellular and Tissue Selectivity of AAV Serotypes for Gene Delivery to Chondrocytes and Cartilage

Background: Despite several studies on the effect of adeno-associated virus (AAV)-based therapeutics on osteoarthritis (OA), information on the transduction efficiency and applicable profiles of different AAV serotypes to chondrocytes in hard cartilage tissue is still limited. Moreover, the recent discovery of additional AAV serotypes makes it necessary to screen for more suitable AAV serotypes for specific tissues. Here, we compared the transduction efficiencies of 14 conventional AAV serotypes in human chondrocytes, mouse OA models, and human cartilage explants obtained from OA patients. Methods: To compare the transduction efficiency of individual AAV serotypes, green fluorescent protein (GFP) expression was detected by fluorescence microscopy or western blotting. Likewise, to compare the transduction efficiencies of individual AAV serotypes in cartilage tissues, GFP expression was determined using fluorescence microscopy or immunohistochemistry, and GFP-positive cells were counted. Results: Only AAV2, 5, 6, and 6.2 exhibited substantial transduction efficiencies in both normal and OA chondrocytes. All AAV serotypes except AAV6 and rh43 could effectively transduce human bone marrow mesenchymal stem cells. In human and mouse OA cartilage tissues, AAV2, AAV5, AAV6.2, AAV8, and AAV rh39 showed excellent tissue specificity based on transduction efficiency. These results indicate the differences in transduction efficiencies of AAV serotypes between cellular and tissue models. Conclusions: Our findings indicate that AAV2 and AAV6.2 may be the best choices for AAV-mediated gene delivery into intra-articular cartilage tissue. These AAV vectors hold the potential to be of use in clinical applications to prevent OA progression if appropriate therapeutic genes are inserted into the vector

Nanoparticle tracking analysis of gold nanoparticles in aqueous media through an inter-laboratory comparison

In the field of nanotechnology, analytical characterization plays a vital role in understanding the behavior and toxicity of nanomaterials (NMs). Characterization needs to be thorough and the technique chosen should be well-suited to the property to be determined, the material being analyzed and the medium in which it is present. Furthermore, the instrument operation and methodology need to be well-developed and clearly understood by the user to avoid data collection errors. Any discrepancies in the applied method or procedure can lead to differences and poor reproducibility of obtained data. This paper aims to clarify the method to measure the hydrodynamic diameter of gold nanoparticles by means of Nanoparticle Tracking Analysis (NTA). This study was carried out as an inter-laboratory comparison (ILC) amongst seven different laboratories to validate the standard operating procedure’s performance and reproducibility. The results obtained from this ILC study reveal the importance and benefits of detailed standard operating procedures (SOPs), best practice updates, user knowledge, and measurement automation

Distribution of Corynebacterium Species and Comparative Results of Diagnostic Methods for Identifying Corynebacterium in Experimental Mice in Korea

The genus Corynebacterium, composed of Gram-positive diphtheroid rod-shaped bacteria, induces severe diseases, such as Corynebacterium-associated hyperkeratosis and pseudotuberculosis, in immunodeficient mice. We isolated and identified a total of 165 strains of Corynebacterium species from experimental mice in Korean laboratories, diagnosed using several methods. When identified based on molecular methods, namely, 16S rRNA and rpoB gene sequence analysis, the main Corynebacterium species isolated in Korean laboratory mice were C. mastitidis (44.8%, n = 74), C. bovis (25.5%, n = 42), C. lowii (21.2%, n = 35), and C. amycolatum (8.5%, n = 14). Diagnoses were also performed using matrix-assisted laser desorption/ionization–time of flight mass spectrometry (MALDI-TOF MS) and biochemical methods. MALDI-TOF MS yielded results that were 77.9% identical to the molecular identification results, whereas biochemical methods showed only 15.5% identical to molecular identification, partly owing to difficulties in distinguishing among C. mastitidis strains. Collectively, our findings indicate that molecular biological methods are better suited for detecting and identifying Corynebacterium species candidates isolated from mice than biochemical methods. Because of limitations associated with the use of MALDI-TOF MS, more precise results will be obtained by complementing this approach with other methods when used for rapid identification testing

Off-Target Editing by CRISPR-Guided DNA Base Editors

Base editing is a genome editing strategy that induces specific single-nucleotide changes within genomic DNA. Two major DNA base editors, cytosine base editors and adenine base editors, that consist of a Cas9 protein linked to a deaminase enzyme that catalyzes targeted base conversion directed by a single-guide RNA have been developed. This strategy has been used widely for precise genome editing because, unlike CRISPR-Cas nuclease-based genome editing systems, this strategy does not create double-strand DNA breaks that often result in high levels of undesirable indels. However, recent papers have reported that DNA base editors can cause substantial off-target editing in both genomic DNA and RNA. The off-target editing described in these studies is primarily independent of guide RNA and arises from the promiscuous reactivity of the deaminase enzymes used in DNA base editors. In this Perspective, we discuss the development of DNA base editors, the guide RNA-independent off-target activity reported in recent studies, and strategies that improve the selectivity of DNA base editors

Transit Ridership Evaluation Using Aggregate-Level Causal Analyses of Subway Mode Shares in Seoul, South Korea

Adequate evaluations of transit system efficiency in direct connection with environmental concerns and the economic aspects of the city are critical for development of a better system. This paper presents an evaluation framework by comparing the subway mode shares of 25 districts in Seoul, South Korea. In this effort, causal relationships between the inherent conditions of the district and the resultant mode shares were identified on the basis of regression models with independent variables indicating the system supply level. The expected mode shares from the regression model and the actual shares were then compared as a way to identify districts displaying relatively higher or lower subway mode shares. These processes revealed key influential factors affecting subway mode share and suggest that the system supply level is strongly related to mode share and that ridership increases may be achieved by providing convenient access to stations. The implications of this study are expected to shed light on potential policy actions to improve transit ridership, particularly for those districts with relatively lower levels of ridership