653 research outputs found

    How Korean K-12 Educators Adapted to Online Teaching and Promoted Digital Equity During COVID-19: A Mixed-Method Study on Practices and Perceptions

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    The abrupt transitions to online teaching during COVID-19 have exacerbated educational discrepancies worldwide. South Korean schools faced similar challenges primarily due to the insufficient infrastructure and pedagogical guidelines for online teaching. This mixed-method case study investigated how Korean K-12 teachers and administrators converted to online teaching and addressed related digital equity issues during their first semester of online teaching in response to the pandemic. Interviews, as well as survey responses at the beginning and end of the semester, were analyzed through Activity Theory (AT) and Technological Pedagogical Content Knowledge (TPACK) frameworks. The study's key insights were that the digital equity issue is related to quality teaching issues beyond infrastructural problems and that teachers took various strategies to maximize the effectiveness of their blended teaching. We aim to shed light on supporting equitable online learning and sustaining positive changes in the post-COVID era

    Carotid Intimal-Medial Thickness Is Not Increased in Women with Previous Gestational Diabetes Mellitus

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    BackgroundGestational diabetes mellitus (GDM) is known to increase the risk of cardiovascular diseases. Measuring the carotid artery intimal-medial thickness (CIMT) is a non-invasive technique used to evaluate early atherosclerosis and to predict future cardiovascular diseases. We examined the association between CIMT and cardiovascular risk factors in young Korean women with previous GDM.MethodsOne hundred one women with previous GDM and 19 women who had normal pregnancies (NP) were recruited between 1999 and 2002. At one year postpartum, CIMT was measured using high-resolution B-mode ultrasonography, and oral glucose tolerance tests were performed. Fasting glucose, glycated hemoglobin A1c (HbA1c), insulin levels and lipid profiles were also measured. CIMTs in the GDM and NP groups were compared, and the associations between CIMT and cardiovascular risk factors were analyzed in the GDM group.ResultsCIMT results of the GDM group were not significantly different from those of the NP group (GDM, 0.435±0.054 mm; NP, 0.460±0.046 mm; P=0.069). In the GDM group, a higher HbA1c was associated with an increase in CIMT after age adjustment (P=0.011). CIMT results in the group with HbA1c >6.0% were higher than those of the normal HbA1c (HbA1c ≤6.0%) (P=0.010). Nine of the patients who are type 2 diabetes mellitus converters within one year postpartum but showed no significant difference in CIMT results compared to NP group.ConclusionHigher HbA1c is associated with an increase in CIMT in women with previous GDM. However, CIMT at one year postpartum was not increased in these women compared to that in NP women

    A Feasibility Study on the Application of TVDI on Accessing Wildfire Danger in the Korean Peninsula

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    Wildfire is a major natural disaster affecting socioeconomics and ecology. Remote sensing data have been widely used to estimate the wildfire danger with an advantage of higher spatial resolution. Among the several wildfire related indices using remote sensing data, Temperature Vegetation Dryness Index (TVDI) assesses wildfire danger based on both Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST). Although TVDI has physical advantages by considering both weather and vegetation condition, previous studies have shown TVDI does not performed well compare to other wildfire related indices over the Korean Peninsula. In this study we have attempted multiple modification to improve TVDI performance over the study region. In-situ measured air temperature was employed to increase accuracy, regression line was generated using monthly data to include seasonal effect, and TVDI was calculated at each province level to consider vegetation type and local climate. The modified TVDI calculation method was evaluated in wildfire cases and showed significant improvement in wildfire danger estimation

    Eyelid Squamous Cell Carcinoma in a Dog

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    A 10-year-old, female, Yorkshire Terrier was presented with a left lower eyelid mass. No other abnormality was detected on affected eye in a general eye examination. The mass was surgically removed and histologically diagnosed as a squamous cell carcinoma. The advancement flap used in this case may be an appropriate therapeutic choice for eyelid squamous cell carcinoma in dogs

    Facile synthesis of hybrid graphene and carbon nanotubes as a metal-free electrocatalyst with active dual interfaces for efficient oxygen reduction reaction

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    We report metal-free electrocatalysts to enhance utilization of dissolved and gaseous oxygen during oxygen reduction reaction (ORR). Proper balance between hydrophobicity and hydrophilicity is achieved using reduced graphene oxide (rGO) and polyelectrolyte functionalized multiwalled carbon nanotubes (pMWNTs). In this unique architecture, both two- and three-phase reactions in ORR can be maximized with a quasi-four-electron pathway.close6

    Effect of Combination Therapy with Sodium Ozagrel and Panax Ginseng on Transient Cerebral Ischemia Model in Rats

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    Sodium ozagrel (SO) prevents platelet aggregation and vasoconstriction in the cerebral ischemia. It plays an important role in the prevention of brain damage induced by cerebral ischemia/reperfusion. Recently, many animal studies have suggested that the Panax ginseng (PG) has neuroprotective effects in the ischemic brain. In this study, we assessed the neuroprotective effects that come from a combination therapy of SO and PG in rat models with middle cerebral artery occlusion (MCAO). Animals with MCAO were assigned randomly to one of the following four groups: (1) control (Con) group, (2) SO group (3 mg/kg, intravenously), (3) PG group (200 mg/kg, oral feeding), and (4) SO + PG group. The rats were subjected to a neurobehavior test including adhesive removal test and rotarod test at 1, 3, 7, 10, and 15 days after MCAO. The cerebral ischemic volume was quantified by Metamorph imaging software after 2-3-5-triphenyltetrazolium (TTC) staining. The neuronal cell survival and astrocytes expansion were assessed by immunohistofluorescence staining. In the adhesive removal test, the rats of PG or SO + PG group showed significantly better performance than those of the control group (Con: 88.1 ± 24.8, PG: 43.6 ± 11, SO + PG: 11.8 ± 7, P < .05). Notably, the combination therapy group (SO + PG) showed better performance than the SO group alone (SO: 56 ± 12, SO + PG: 11.8 ± 7, P < .05). In TTC staining for infarct volume, cerebral ischemic areas were also significantly reduced in the PG group and SO + PG group (Con: 219 ± 32, PG: 117 ± 8, SO + PG: 99 ± 11, P < .05). Immunohistofluorescence staining results showed that the group which received SO + PG group therapy had neuron cells in the normal range. They also had a low number of astrocytes and apoptotic cells compared with the control or SO group in the peri-infarction area. During astrocytes staining, compared to the SO + PG group, the PG group showed only minor differences in the number of NeuN-positive cells and quantitative analysis of infarct volume. In conclusion, these studies showed that in MCAO rat models, the combination therapy with SO and PG may provide better neuroprotective effects such as higher neuronal cell survival and inhibition of astrocytes expansion than monotherapy with SO alone
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