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Based on a widely held belief that immersion provides the best language learning opportunities, a large number of Asian students go to English-speaking countries to improve their English language skills. These strongly motivated learners arrive in a new country with a bag of expectations, learner beliefs, and imaginations about the new community they are about to enter. However, learners are often faced with a set of challenges with respect to language learning opportunities and identity negotiations in the new community. Against this background, the present study examined three cases of Korean learners enrolled in an intensive English program (IEP) in the U.S. The aim of the study was to understand distinct struggles experienced by this learner population. The study found that the participants had certain motivations and imaginations about the new communities, but they experienced numerous challenges and struggles particularly with regard to opportunities for authentic communications in English and identity conflicts. The paper discusses pedagogical implications for an effective IEP curriculum to allow students more opportunities for legitimate periphery participation in the target language communities of practice.

Learning to use English articles appropriately has been considered a challenging task for L2 learners of English, especially when their L1s do not have a similar article system. Much research has been conducted in this area, but little has been studied about the effects of discourse types (i.e., spoken discourse versus written discourse) on the accurate production of English articles by L2 learners. The present study examined how Korean learners of English at distinct proficiency levels employed articles in oral narratives compared to written narratives. The results showed that the cognitive and performance constraints associated with spontaneous oral speech hindered learners from producing articles accurately. Furthermore, the effects of discourse types were found to be greater on the indefinite article, whose usage is considered more complex than the definite article. Concerning the proficiency levels, the intermediate learners exhibited patterns that are indicative of a considerable gap between implicit and explicit knowledge of English articles while the advanced learners seem to have stabilized in their use of articles. The findings of this study suggest that writing activities can be beneficial for learners at the beginning levels to increase the awareness of the English article system. For more proficient learners, speaking activities can be used to promote a more accurate production of articles in both speech and writing by utilizing their explicit knowledge of English articles.

Therapeutic electrical stimulation, such as transcranial cortical stimulation and peripheral somatosensory stimulation, is used to improve motor function in patients with stroke. We hypothesized that these stimulations exert neuroprotective effects during the subacute phase of ischemic stroke by regulating novel common signaling pathways. Male C57BL/6J mouse models of ischemic stroke were treated with high-definition (HD)-transcranial alternating current stimulation (tACS; 20 Hz, 89.1 A/mm2), HD-transcranial direct current stimulation (tDCS; intensity, 55 A/mm2; charge density, 66,000 C/m2), or electroacupuncture (EA, 2 Hz, 1 mA) in the early stages of stroke. The therapeutic effects were assessed using behavioral motor function tests. The underlying mechanisms were determined using transcriptomic and other biomedical analyses. All therapeutic electrical tools alleviated the motor dysfunction caused by ischemic stroke insults. We focused on electrically stimulating common genes involved in apoptosis and cell death using transcriptome analysis and chose 11 of the most potent targets (Trem2, S100a9, Lgals3, Tlr4, Myd88, NF-kB, STAT1, IL-6, IL-1β, TNF-α, and Iba1). Subsequent investigations revealed that electrical stimulation modulated inflammatory cytokines, including IL-1β and TNF-α, by regulating STAT1 and NF-kB activation, especially in amoeboid microglia; moreover, electrical stimulation enhanced neuronal survival by activating neurotrophic factors, including BDNF and FGF9. Therapeutic electrical stimulation applied to the transcranial cortical- or periphery-nerve level to promote functional recovery may improve neuroprotection by modulating a common neuronal death pathway and upregulating neurotrophic factors. Therefore, combining transcranial cortical and peripheral somatosensory stimulation may exert a synergistic neuroprotective effect, further enhancing the beneficial effects on motor deficits in patients with ischemic stroke. [ABSTRACT FROM AUTHOR]

With the increasing use of unmanned aerial vehicles (UAVs) in various fields, achieving the precise localization of UAV images is crucial for enhancing their utility. Photogrammetry-based techniques, particularly bundle adjustment, serve as foundational methods for accurately determining the spatial coordinates of UAV images. The effectiveness of bundle adjustment is significantly influenced by the selection of input data, particularly the composition of overlapping image sets. The selection process of overlapping images significantly impacts both the accuracy of spatial coordinate determination and the computational efficiency of UAV image localization. Therefore, a strategic approach to this selection is crucial for optimizing the performance of bundle adjustment in UAV image processing. In this context, we propose an efficient methodology for determining overlapping image sets. The proposed method selects overlapping images based on image similarity, leveraging the complementary strengths of the bag of visual words and number of matches techniques. Essentially, our method achieves both high accuracy and high speed by utilizing a Bag of Visual Words for candidate selection and the number of matches for additional similarity assessment for overlapping image-set determination. We compared the performance of our proposed methodology with the conventional number of matches and bag-of-visual word-based methods for overlapping image-set determination. In the comparative evaluation, the proposed method demonstrated an average precision of 96%, comparable to that of the number of matches-based approach, while surpassing the 62% precision achieved by both bag-of-visual-word methods. Moreover, the processing time decreased by approximately 0.11 times compared with the number of matches-based methods, demonstrating relatively high efficiency. Furthermore, in the bundle adjustment results using image sets, the proposed method, along with the number of matches-based methods, showed reprojection error values of less than 1, indicating relatively high accuracy and contributing to the improvement in accuracy in estimating image positions. [ABSTRACT FROM AUTHOR]