1,437 research outputs found

    Retelling as an effective reading comprehension strategy for young ESL learners

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    Retelling is not a new strategy, but it has been underestimated for a long time. This study investigates the effectiveness of retelling as a reading strategy for elementary school students of English as a Second Language (ESL). Two first graders, three second graders, and three fifth graders participated in the study. They were divided into two groups (Group A and B) considering their English competence and other factors. Their retelling outcomes including oral, written and drawings during 2 months period were collected and analyzed. During the study, students were being read stories and asked to retell the stories orally and/ or in written and/ or in drawings. The results show a noticeable improvement in their story structure, length of the retelling, reading comprehension, and confidence. No major improvement in vocabulary growth was found, in spite of individual difference. Self-evaluations and observation results indicate that the participants enjoyed story readings, their attitude toward reading became more positive and they gained self-confidence. The results suggest that retelling could be a useful reading strategy for ESL learners with its potential

    Facile Method to Prepare for the Ni2P Nanostructures with Controlled Crystallinity and Morphology as Anode Materials of Lithium-Ion Batteries

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    Conversion reaction materials (transition metal oxides, sulfides, phosphides, etc.) are attractive in the field of lithium-ion batteries because of their high theoretical capacity and low cost. However, the realization of these materials in lithium-ion batteries is impeded by large voltage hysteresis, high polarization, inferior cycle stability, rate capability, irreversible capacity loss in first cycling, and dramatic volume change during redox reactions. One method to overcome these problems is the introduction of amorphous materials. This work introduces a facile method to synthesize amorphous and crystalline dinickel phosphide (Ni2P) nanoparticle clusters with identical morphology and presents a direct comparison of the two materials as anode materials for rechargeable lithium-ion batteries. To assess the effect of crystallinity and hierarchical structure of nanomaterials, it is crucial to conserve other factors including size, morphology, and ligand of nanoparticles. Although it is rarely studied about synthetic methods of well-controlled Ni2P nanomaterials to meet the above criteria, we synthesized amorphous, crystalline Ni2P, and self-assembled Ni2P nanoparticle clusters via thermal decomposition of nickel-surfactant complex. Interestingly, simple modulation of the quantity of nickel acetylacetonate produced amorphous, crystalline, and self-assembled Ni2P nanoparticles. A 0.357 M nickel-trioctylphosphine (TOP) solution leads to a reaction temperature limitation (similar to 315 degrees C) by the nickel precursor, and crystalline Ni2P (c-Ni2P) nanoparticles clusters are generated. On the contrary, a lower concentration (0.1 M) does not accompany a temperature limitation and hence high reaction temperature (330 degrees C) can be exploited for the self-assembly of Ni2P (s-Ni2P) nanoparticle clusters. Amorphous Ni2P (a-Ni2P) nanoparticle clusters are generated with a high concentration (0.714 M) of nickel-TOP solution and a temperature limitation (similar to 290 degrees C). The a-Ni2P nanoparticle cluster electrode exhibits higher capacities and Coulombic efficiency than the electrode based on c-Ni2P nanoparticle clusters. In addition, the amorphous structure of Ni2P can reduce irreversible capacity and voltage hysteresis upon cycling. The amorphous morphology of Ni2P also improves the rate capability, resulting in superior performance to those of c-Ni2P nanoparticle clusters in terms of electrode performance

    Endoplasmic reticulum stress and apoptosis induced by manganese trigger α-synuclein accumulation

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    Purpose: To explore whether α-synuclein aggregation is linked to endoplasmic reticulum (ER) stress and apoptosis induced by manganese (Mn) on CATH.a dopaminergic cell lines.Methods: Western blot analysis for the expression of 78 kDa glucose-regulated protein (GRP78), phosphorylated eukaryotic initiation factor 2α (p-eIF-2α), eIF2α, inositol requiring enzyme 1(IRE-1α), cleaved caspase-3, and C/EBP homologous protein (CHOP) was performed, including overexpression of recombinant adenovirus-mediated α-synuclein on CATH.a dopaminergic cell line.Results: It was observed that cell viability (p < 0.05) was significantly reduced by 250 μM exposed for 3h and 1,000 μM of MnCl2 exposed for 24 h. The expression of p-elF-2α, IRE-1α, and GRP78 was especially induced by 1,000 μM of MnCl2 exposed at 3, 6, and 12 h, respectively (p < 0.05). Twenty four-hour exposure of 250 uM of MnCl2 and the 3 h exposure of 1,000 uM of MnCl2 significantly induced CHOP, active caspase 3 and α-synuclein expression (p < 0.05). α-Synuclein combined with recombinant adenoviral transduction increased GRP78, IRE-1α and eIF2a, CHOP and caspase 3 expression at longer times and at higher concentrations of manganese exposure on CATH.a dopaminergic cells.Conclusion: Based on these findings, Mn is a risk factor for diseases associated with α-synuclein accumulation. Furthermore, α-synuclein accumulation is associated with apoptosis via ER stress induced by Mn.Keywords: Manganese (Mn), α- Synuclein, Endoplasmic reticulum (ER) stress, Apoptosi

    Avian species survey with citizen-science data in Janghang Wetland, Goyang, Republic of Korea

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    Monitoring of avian populations in Janghang Wetland, Goyang, Republic of Korea (ROK) is based on citizen science (also called community-based monitoring). This monitoring data can be used to track avian density, population status and waterbird census at local, national and regional levels. The Ministry of Environment (MoE) ROK has surveyed since 1999, including Odusan Unification Tower to Ilsan Bride, which connects the cities of Gimpo and Goyang along the Han River estuary. However, it has not covered Janghang Wetland, which is located in the Han River estuary at the transboundary between the two Koreas. The Janghang Wetland is a protected wetland in the Demilitarized Zone (DMZ) between the two Koreas. In 2019, Janghang Wetland was designated as a Flyway Network Site by Goyang City and the East Asian-Australasian Flyway Partnership. This Network site is a voluntary collaboration and includes many internationally significant wetlands for waterbirds that still lack formal national protection. In addition, it was designated as a Ramsar site in 2021. The wetland currently supports wintering population of White-naped Crane (Grus vipio), species listed as vulnerable and Tundra Bean Goose (Anser cygnoides), spring-autumn migration population of Swan Goose (Anser cygnoid), species listed as vulnerable and a breeding population of Black-faced Spoonbill (Platalea minor), species listed as endangered in summer.We provide data that the Janghang Wetland is a significant area for migration and breeding for waterbirds; and that Han River estuary is also internationally important for waterbirds during the migratory bird season. We observed 14 orders, 42 families and 132 species. The surveys also observed the critically-endangered Black-faced Spoonbill (Platalea minor), Swan Goose (Anser cygnoides), White-naped Crane (Grus vipio), Whooper Swan (Cygnus cygnus) and Peregrine Falcon (Falco peregrinus). We also observed the Black-faced Spoonbill, Great Egret, Little Egret, Great Cormorant, Eastern Spot-billed Duck, Pheasant and Brown-eared Bulbul at the sensor camera point and White-naped Crane, Hooded Crane, Bean Goose, White-fronted Goose, Snow Goose, Swan Goose, Great Cormorant and Eastern Spot-billed Duck at the closed-circuit television camera point from the camera-trap surveys. Based on the species recorded, the survey area is of clear importance for biodiversity conservation

    Effect of Hydraulic Activity on Crystallization of Precipitated Calcium Carbonate (PCC) for Eco-Friendly Paper

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    Wt% of aragonite, a CaCO3 polymorph, increased with higher hydraulic activity (°C) of limestone in precipitated calcium carbonate (PCC) from the lime-soda process (Ca(OH)2-NaOH-Na2CO3). Only calcite, the most stable polymorph, was crystallized at hydraulic activity under 10 °C, whereas aragonite also started to crystallize over 10 °C. The crystallization of PCC is more dependent on the hydraulic activity of limestone than CaO content, a factor commonly used to classify limestone ores according to quality. The results could be effectively applied to the determination of polymorphs in synthetic PCC for eco-friendly paper manufacture

    Microfluidic-integrated laser-controlled microactuators with on-chip microscopy imaging functionality

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    The fabrication of a novel microfluidic system, integrated with a set of laser-controlled microactuators on an ePetri on-chip microscopy platform, is presented in this paper. In the fully integrated microfluidic system, a set of novel thermally actuated paraffin-based microactuators, precisely controlled by programmed laser optics, was developed to regulate flow and to provide pumping of liquid solutions without external connections. The microfluidic chip was fabricated on a complementary metal–oxide–semiconductor (CMOS)-imaging sensor chip on an ePetri platform; this configuration provided real-time, wide field-of-view, high-resolution imaging using a sub-pixel sweeping microscopy technique. The system of microactuators, which consisted of microvalves and a micropump, operated well in the microfluidic channel with a focused near-infrared laser beam providing the actuation control. As a demonstration, we used our prototype to assess cell–drug interactions and to monitor cell growth directly within an incubator in real time. The powerful combination of laser-actuated microfluidics and chip-scale microscopy techniques represents a significant step forward in terms of a simple, robust, high-throughput, and highly compact analysis system for biomedical and bioscience applications
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