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Estuary-to-bay water-quality coupling in Gwangyang Bay, Korea, was assessed based on observations collected at 12 freshwater inflows and 12 bay sampling points across three hydrological phases operationally classified by antecedent precipitation: immediate post-rain (May), lagged post-rain (July), and dry baseline (October). Concentrations of dissolved silicate (DSi), total nitrogen (TN), and total phosphorus (TP) in freshwater inflows differed significantly among these phases. Riverine nutrient loads exhibited a pronounced event-phase gradient (July > May > October). The Seomjin River contributed 67–91
This study compared Task-Based Language Teaching (TBLT) delivered in virtual reality (VR) and in traditional settings, examining learning gains, transfer, retention, and learner perceptions. 22 participants completed pretests, immediate posttests, transfer tests, and a questionnaire, while 10 of them, selected to balance proficiency across groups based on posttest scores, additionally completed a two-month delayed posttest and follow-up interviews. Wilcoxon signed-rank tests showed significant learning gains in both VR and traditional groups (p < .001; p = .006, in target discourse and p = .004; p = .008 in listening tests). ANCOVA indicated no immediate group difference in posttest scores (p = .205; p = .322) or in transfer measures (p = .608). After two months, a Mann-Whitney U test showed the VR group preserved target discourse significantly better than the traditional group (p = .036). Mann-Whitney U analyses ofLikert-scale responses revealed greater enjoyment (p = .008), perceived retention (p = .009), reported difficulty (p = .01), and motivation (p = .033) in the VR group. Interview analyses (in vivo coding) highlighted VR affordances that promote contextualized practice and positive emotional engagement. These results suggest VR-TBLT may enhance long-term retention and learner engagement compared with traditional TBLT.
The light scattering properties of fine particulate matter (PM2.5) were investigated in a megacity on the North China Plain during periods of substantial PM2.5 variation. The results revealed a non-linear reduction in the scattering efficient (sigma(sp)) relative to decreases in PM2.5 concentrations. Ammonium nitrate (NH4NO3) was the primary contributor to sigma(sp), accounting for 34.7 %-43.3 % at both high and low PM2.5 levels. However, primary organic aerosol (POA) became the largest contributor to sigma(sp) (31.5 %) at medium PM2.5 levels, with secondary organic aerosol (SOA) rising sharply by 13.9 %, collectively sustaining sigma(sp) and limiting its reduction. The scattering & Aring;ngstr & ouml;m exponent (SAE) decreased from 2.1 +/- 0.9 (high PM2.5 levels) by 31.1 %-50.5 % at medium and low levels, indicating a shift towards larger particle sizes as pollution levels declined. Strong negative correlations between SAE and the organic carbon/elemental carbon (OC/EC) ratio (r = -0.193, p < 0.01) at medium PM2.5 levels, as well as the mass scattering efficient (MSE) (r = -0.656, p < 0.01), testified the critical role of SOA formation in enhancing particle size and sigma(sp) under improved air quality conditions. Regression models based solely on aerosol components underestimated sigma(sp), likely due to the exclusion of particle growth and SOA formation. Incorporating POA, SOA and SAE into sigma(sp) calculations significantly improved predictive accuracy by 7 %-21 %. These findings demonstrate that enhanced SOA formation and particle size growth increase MSE and effectively counteract reductions in sigma(sp) despite declining PM2.5 levels, thereby further hindering improvements in atmospheric visibility.
The movement of organisms within river ecosystems has been understood mainly in terms of three dimensions: longitudinal, lateral, and vertical within the water column. However, little is known about the vertical extent of the aerosphere, which is utilised by adult aquatic insects. In this study, vertical adhesive traps were installed on a 59 m-high bridge spanning a mountain stream to investigate a community consisting of adult mayflies, stoneflies, and caddisflies that utilised the aerial zone directly above the river. The results showed that a single female Stenopsyche marmorata Nav & aacute;s, 1920 was captured at a height of 55 m, however, adult insects were concentrated within the zone up to 25 m above the water surface. These observations make a significant contribution to knowledge regarding the flight altitude of adult Ephemeroptera, Plecoptera, and Trichoptera in river ecosystems. Our findings thus indicate that the functional boundaries of river ecosystems can extend to aerosphere. Our article aims to provide new perspectives for re-evaluating conservation strategies for riverine ecosystems, including in relation to the dispersal ecology of aquatic insects and the fragmentation of 'aerial corridors' by artificial structures such as dams.
Surface and bottom water samples collected at 20 sampling points west of Jeju Island, Korea, in the northern East China Sea in July 2025 were analyzed using Temperature-Salinity diagrams and multivariate analyses to characterize water-quality features. A thermocline and halocline were observed within the upper 40 m throughout the study area, together with a west-to-east salinity gradient. In surface waters, Changjiang Diluted Water (CDW) was identified in the western and central parts of the study area, whereas the Taiwan Warm Current was identified in the eastern part. In contrast, bottom-water masses were not distinctly separated, and Yellow Sea Cold Water and Kuroshio-origin Water overlapped in the central part of the study area. Multivariate analyses showed that the southwestern part of the study area was characterized by potential CDW influence in surface water. The results highlight layer-specific clustering patterns, with surface water clustering mainly in relation to water-mass characteristics, whereas bottom waters clustered primarily along a water-depth gradient. CDW may also transport nutrient-imbalanced water characterized by excess nitrogen and relative phosphorus deficiency. This study delineates the summer extent of CDW influence west of Jeju Island and provides a basis for distinguishing potentially CDW-influenced zones in the study area under summer hydrographic conditions. These findings provide an observation-based basis for sustainable marine monitoring in the northern East China Sea, with implications for assessing nutrient imbalance and contaminant transport under summer hydrographic conditions.
