Difficulty-Focused Contrastive Learning for Knowledge Tracing with a Large Language Model-Based Difficulty Prediction

This paper presents novel techniques for enhancing the performance of knowledge tracing (KT) models by focusing on the crucial factor of question and concept difficulty level. Despite the acknowledged significance of difficulty, previous KT research has yet to exploit its potential for model optimization and has struggled to predict difficulty from unseen data. To address these problems, we propose a difficulty-centered contrastive learning method for KT models and a Large Language Model (LLM)-based framework for difficulty prediction. These innovative methods seek to improve the performance of KT models and provide accurate difficulty estimates for unseen data. Our ablation study demonstrates the efficacy of these techniques by demonstrating enhanced KT model performance. Nonetheless, the complex relationship between language and difficulty merits further investigation.Comment: 10 pages, 4 figures, 2 table

Clinical effectiveness of the sequential 4-channel NMES compared with that of the conventional 2-channel NMES for the treatment of dysphagia in a prospective double-blind randomized controlled study

Background To date, conventional swallowing therapies and 2-channel neuromuscular electrical stimulation (NMES) are standard treatments for dysphagia. The precise mechanism of 2-channel NMES treatment has not been determined, and there are controversies regarding the efficacy of this therapy. The sequential 4-channel NMES was recently developed and its action is based on the normal contractile sequence of swallowing-related muscles. Objective To evaluate and compare the rehabilitative effectiveness of the sequential 4-channel NMES with that of conventional 2-channel NMES. Methods In this prospective randomized case–control study, 26 subjects with dysphagia were enrolled. All participants received 2- or 4-channel NMES for 2–3weeks (minimal session: 7 times, treatment duration: 300–800min). Twelve subjects in the 4-channel NMES group and eleven subjects in the 2-channel NMES group completed the intervention. Initial and follow-up evaluations were performed using the videofluoroscopic dysphagia scale (VDS), the penetration-aspiration scale (PAS), the MD Anderson dysphagia inventory (MDADI), the functional oral intake scale (FOIS), and the Likert scale. Results The sequential 4-channel NMES group experienced significant improvement in their VDS (oral, pharyngeal, and total), PAS, FOIS, and MDADI (emotional, functional, and physical subsets) scores, based on their pretreatment data. VDS (oral, pharyngeal, and total) and MDADI (emotional and physical subsets) scores, but not PAS and FOIS scores, significantly improved in the 2-channel NMES group posttreatment. When the two groups were directly compared, the 4-channel NMES group showed significant improvement in oral and total VDS scores. Conclusions The sequential 4-channel NMES, through its activation of the suprahyoid and thyrohyoid muscles, and other infrahyoid muscles mimicking physiological activation, may be a new effective treatment for dysphagia. Trial registration: clinicaltrial.gov, registration number: NCT03670498, registered 13 September 2018, https://clinicaltrials.gov/ct2/show/NCT03670498?term=NCT03670498&draw=2&rank=1 .This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (Grant Number: HI18C1169). This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Min‑ istry of Science, ICT and Future Planning (NRF- NRF-2016R1D1A1B03935130)

Crystal structure and pyridoxal 5-phosphate binding property of lysine decarboxylase from Selenomonas ruminantium

Lysine decarboxylase (LDC) is a crucial enzyme for acid stress resistance and is also utilized for the biosynthesis of cadaverine, a promising building block for bio-based polyamides. We determined the crystal structure of LDC from Selenomonas ruminantium (SrLDC). SrLDC functions as a dimer and each monomer consists of two distinct domains; a PLPbinding barrel domain and a sheet domain. We also determined the structure of SrLDC in complex with PLP and cadaverine and elucidated the binding mode of cofactor and substrate. Interestingly, compared with the apo-form of SrLDC, the SrLDC in complex with PLP and cadaverine showed a remarkable structural change at the PLP binding site. The PLP binding site of SrLDC contains the highly flexible loops with high b-factors and showed an open-closed conformational change upon the binding of PLP. In fact, SrLDC showed no LDC activity without PLP supplement, and we suggest that highly flexible PLP binding site results in low PLP affinity of SrLDC. In addition, other structurally homologous enzymes also contain the flexible PLP binding site, which indicates that high flexibility at the PLP binding site and low PLP affinity seems to be a common feature of these enzyme family.close0

Compositional Effect of Thin Electrode Functional Layers on the Performance of Solid Oxide Fuel Cells

Anode supported solid oxide fuel cells (SOFC) were fabricated by addition of various metal oxides such as Fe2O3, Co 3O4 and TiO2 to thin anode functional layers between the electrolyte (yttria-stabilized zirconia, YSZ) and electrode materials (anode support: YSZ-NiO). Effect of the additives on the power density and impedance spectra of SOFC was studied. It was found that addition of Co3O4 to anode functional layer was most effective towards improvement of power densities and reduction of the total ohmic resistance as well as the area specific resistance of the cells, while addition of TiO 2 to anode functional layer resulted in lower power densities. Possible mechanisms on the relationship between the additives in electrode functional layers and the cell performance were briefly discussed

KONTRIBUSI BIMBINGAN ORANG TUA DAN GURU TERHADAP PERILAKU SOSIAL EMOSIONAL ANAK USIA DINI :Studi Deskriptif Analitik terhadap Perilaku Sosial-Emosional Anak Taman Kanak-Kanak Kelompok B di Kecamatan Sindang Kabupaten Indramayu Tahun ajaran 2008/2009

Penelitian ini bertitik tolak dari permasalahan umum yaitu bagaimana kontribusi bimbingan orang tua dan guru terhadap perilaku sosial-emosional anak usia dini di lembaga pendidikan Taman Kanak-Kanak di-Kecamatan Sindang Kabupaten Indramayu. Adapun batasan masalah dimuat dengan beberapa pertanyaan yaitu bagaimana aktivitas bimbingan orang tua, guru, dan perilaku sosial emosional anak serta kontribusi masing-masing dari variabel-variabel orang tua dan guru terhadap perilaku anak. Metode dalam penelitian ini yaitu menggunakan metode deskriptif analitik dengan teknik survey, metode deskriptif adalah metode yang memusatkan perhatiannya terhadap fenomena yang terjadi pada saat ini dan dalam penelitian ini menggambarkan fenomena yang diselidiki. Adapun pendekatan penelitian ini menggunakan pendekatan kuantitatif korelasional, yaitu pendekatan yang memungkinkan dilakukan pencatatan data hasil penelitian secara nyata dalam bentuk angka sehingga memudahkan proses analisis data dan penafsirannya. Analisis yang dipakai adalah analisis korelasional, regresi dan kontribusi. Menurut Casey (2000) Perkembangan anak usia dini (early child development, ECD) adalah periode perkembangan yang paling cepat pada kehidupan manusia. Pada masa ini, pertumbuhan anak berlangsung dengan cepat. Selain itu kompetisi kognitif, emosi, dan sosial mulai dibentuk dan diperluas. Orang tua adalah guru yang pertama dan utama sekaligus sumber kasih sayang yang paling tulus bagi anak. di sekolah figure guru sebagai kunci. Gurulah panutan utama bagi anak didik, semua sikap dan perilaku guru akan dilihat, didengar dan ditiru oleh anak didik. Anak membutuhkan bimbingan orang dewasa untuk mengetahui apa yang perlu dipelajarinya dan membutuhkan dorongan untuk menguatkan apa yang telah berhasil di pelajarinya. Lingkungan yang kondusip dan dukungan orang tua akan sangat banyak membantu memperlancar rangkaian proses pembelajaran. Dari hasil temuan bahwa bimbingan orang tua, guru dan perilaku sosial emosional anak termasuk dalam kategori baik. Adapun kontribusi yang diberikan, untuk bimbingan orang tua dalam membentuk perilaku sosial emosional anak sebesar 43, guru 31%, dan kalau bersama-sama sebesar 55%. Berdasarkan temuan di atas direkomendasikan baik untuk orang tua atau guru disarankan untuk mempertahankan bimbingan yang telah dilakukan dan untuk mencapai hasil yang lebih baik lagi secara masing-masing harus terus meningkatkan bimbinganya dan juga mengadakan kerja sama antara orang tua dan guru dalam membentuk perilaku sosial emosional anak, sehingga dalam menghadapi persoalan anak dapat diatasi dengan mudah

Peanut-induced acute oxalate nephropathy with acute kidney injury

Oxalate nephropathy is commonly caused by ethylene glycol, vitamin C, and foods like star fruit that contain a lot of oxalate. Peanuts also have high oxalate contents. However, case reports of peanut-induced oxalate nephropathy are not common. Here, we describe a case of peanut-induced acute oxalate nephropathy with acute kidney injury and intend to demonstrate the conditions under which peanut-induced oxalate nephropathy is likely to occur

Structural insight into bi-functional malonyl-CoA reductase

The bi-functional malonyl-CoA reductase is a key enzyme of the 3-hydroxypropionate bi-cycle for bacterial CO2 fixation, catalysing the reduction of malonyl-CoA to malonate semialdehyde and further reduction to 3-hydroxypropionate. Here, we report the crystal structure and the full-length architecture of malonyl-CoA reductase from Porphyrobacter dokdonensis. The malonyl-CoA reductase monomer of 1230 amino acids consists of four tandemly arranged short-chain dehydrogenases/reductases, with two catalytic and two non-catalytic short-chain dehydrogenases/reductases, and forms a homodimer through paring contact of two malonyl-CoA reductase monomers. The complex structures with its cofactors and substrates revealed that the malonyl-CoA substrate site is formed by the cooperation of two short-chain dehydrogenases/reductases and one novel extra domain, while only one catalytic short-chain dehydrogenase/reductase contributes to the formation of the malonic semialdehyde-binding site. The phylogenetic and structural analyses also suggest that the bacterial bi-functional malonyl-CoA has a structural origin that is completely different from the archaeal mono-functional malonyl-CoA and malonic semialdehyde reductase, and thereby constitute an efficient enzyme

Kirigami-inspired gas sensors for strain-insensitive operation

Wearable electronics for the Internet of Things (IoT) have spurred interest in optimizing stretchable substrates, electrodes, and sensing materials. Specifically, wearable gas sensors are valuable for real-time monitoring of hazardous chemicals. For wearable gas sensors, a stable operation under mechanical deformation is required. Here, we introduce strain-insensitive Kirigami-structured gas sensors decorated with titanium dioxide (TiO2) functionalized carbon nanotubes (CNTs) for NO2 sensing. The Kirigami-shaped substrate is used to ensure mechanical stability when stretched. The developed device shows only a 1.3 % change in base resistance under 80 % strain. In addition, the impact of electro-thermal properties at various strain levels is analyzed to aid the understanding of the device's performance. The CNT-TiO2 composite induced alterations in p-n heterojunctions, improving the measurement sensitivity by approximately 250 % compared to a bare CNT sensor. Additionally, the sensors exhibited a 10-fold faster desorption rate due to the enhanced photocatalytic effect of TiO2 under UV exposure. Remarkably, the Kirigami-structured gas sensors maintained stable and repetitive sensing operation even under 80 % strain, which would be enough to be used in various wearable applications