393 research outputs found

    Analysis On Runoff Characteristics Of Decentralized Rainwater Management System Using XP-SWMM Simulation

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    In recent years, impervious areas are increasing in residential zone as well as unsettled area with rapid urbanization and land use. Consequently, this phenomenon influences weak urban environmental compositions about climate change including urban flooding accidents. Therefore, a new paradigm on rainwater management is needed for sound and sustainable restoration of hydrological circulation. Recently, a novel rainwater management system has been developed and recommended for irrigation and flood control in Korea. Especially, P city is now planning a new rainwater management system adopting LID (Low Impact Development) techniques on a small scale development area. In this study, XP-SWMM was used to simulate effects on runoff characteristics by installation of 8 kinds of rainwater management facilities on small scale development area (4.2 ha) of P city in Korea. Also, flood control safety analysis under the condition of localized torrential downpour event was carried out and effects of rainwater recycling facility was evaluated to measure annual water resource amount and water cost reduction. Peak rate runoff was reduced 11.8% and 36.4% in restrict A and B, respectively. Total amount of annual water source substitution was estimated 3,000㎡/yr with LID adoption in land use planning. Acknowledgement : This research was supported by a grant (12-TI-C01) from Advanced Water Management Research Program funded by Ministry of Land , Infrastructure, and Transport of Korean government

    Comparison of air pollution and the prevalence of allergy-related diseases in Incheon and Jeju City

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    PurposeA high level of air pollutants can increase the number of patients with allergy-related diseases such as asthma and allergic rhinitis (AR). To analyze the association between air pollution and allergic disease, we investigated 2 areas in Korea: Incheon, an industrial area, and Jeju, a non-industrialized area.MethodsSecond grade students at elementary schools (11 schools in Incheon and 45 schools in Jeju) were examined in a cross-sectional study. A questionnaire was used and a skin prick test was performed. The levels of NO2, CO2, O3, particulate matter (PM) PM10/2.5, formaldehyde, tVOCs, and dust mites in the classrooms and grounds were determined.ResultsThe levels of outdoor CO, PM10, and PM2.5 were significantly higher in Incheon (P<0.01). The levels of indoor CO, CO2, PM10, PM2.5 were significantly higher in Incheon (P<0.01). The prevalence rates of AR symptoms at any time, AR symptoms during the last 12 months, diagnosis of rhinitis at any time, and AR treatment during the last 12 months were significantly higher in Incheon (P<0.01). The prevalence rate of wheezing or whistling at any time, and wheezing during the last 12 months were significantly higher in Incheon (P<0.01).ConclusionWe found that the children living in Incheon, which was more polluted than Jeju, had a higher rate of AR and asthma symptoms compared to children in Jeju. To determine the effect of air pollution on the development of the AR and asthma, further studies are needed

    Akt regulates the expression of MafK, synaptotagmin I, and syntenin-1, which play roles in neuronal function

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    <p>Abstract</p> <p>Background</p> <p>Akt regulates various cellular processes, including cell growth, survival, and metabolism. Recently, Akt's role in neurite outgrowth has also emerged. We thus aimed to identify neuronal function-related genes that are regulated by Akt.</p> <p>Methods</p> <p>We performed suppression subtractive hybridization on two previously established PC12 sublines, one of which overexpresses the wild-type (WT) form and the other, the dominant-negative (DN) form of Akt. These sublines respond differently to NGF's neuronal differentiation effect.</p> <p>Results</p> <p>A variety of genes was identified and could be classified into several functional groups, one of which was developmental processes. Two genes involved in neuronal differentiation and function were found in this group. v-Maf musculoaponeurotic fibrosarcoma oncogene homolog K (MafK) induces the neuronal differentiation of PC12 cells and immature telencephalon neurons, and synaptotagmin I (SytI) is essential for neurotransmitter release. Another gene, <it>syntenin-1 </it>(<it>Syn-1</it>) was also recognized in the same functional group into which <it>MafK </it>and <it>SytI </it>were classified. Syn-1 has been reported to promote the formation of membrane varicosities in neurons. Quantitative reverse transcription polymerase chain reaction analyses show that the transcript levels of these three genes were lower in PC12 (WT-Akt) cells than in parental PC12 and PC12 (DN-Akt) cells. Furthermore, treatment of PC12 (WT-Akt) cells with an Akt inhibitor resulted in the increase of the expression of these genes and the improvement of neurite outgrowth. These results indicate that dominant-negative or pharmacological inhibition of Akt increases the expression of <it>MafK</it>, <it>SytI</it>, and <it>Syn-1 </it>genes. Using lentiviral shRNA to knock down endogenous Syn-1 expression, we demonstrated that Syn-1 promotes an increase in the numbers of neurites and branches.</p> <p>Conclusions</p> <p>Taken together, these results indicate that Akt negatively regulates the expression of <it>MafK</it>, <it>SytI</it>, and <it>Syn-1 </it>genes that all participate in regulating neuronal integrity in some way or another.</p

    Synergistic effect of Indium and Gallium co-doping on growth behavior and physical properties of hydrothermally grown ZnO nanorods

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    We synthesized ZnO nanorods (NRs) using simple hydrothermal method, with the simultaneous incorporation of gallium (Ga) and indium (In), in addition, investigated the co-doping effect on the morphology, microstructure, electronic structure, and electrical/optical properties. The growth behavior of the doped NRs was affected by the nuclei density and polarity of the (001) plane. The c-axis parameter of the co-doped NRs was similar to that of undoped NRs due to the compensated lattice distortion caused by the presence of dopants that are both larger (In3+) and smaller (Ga3+) than the host Zn2+ cations. Red shifts in the ultraviolet emission peaks were observed in all doped NRs, owing to the combined effects of NR size, band gap renormalization, and the presence of stacking faults created by the dopant-induced lattice distortions. In addition, the NR/p-GaN diodes using co-doped NRs exhibited superior electrical conductivity compared to the other specimens due to the increase in the charge carrier density of NRs and the relatively large effective contact area of (001) planes. The simultaneous doping of In and Ga is therefore anticipated to provide a broader range of optical, physical, and electrical properties of ZnO NRs for a variety of opto-electronic applications

    Association between physical activity and episodic memory and the moderating effects of the apolipoprotein E Δ4 allele and age

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    BackgroundAn abundance of evidence indicates that physical activity may protect against Alzheimer’s disease (AD) and related cognitive decline. However, little is known about the association between physical activity and AD-related cognitive decline according to age and the apolipoprotein E (APOE) Δ4 allele (APOE4) as major risk factors. Therefore, we examined whether age and APOE4 status modulate the effects of physical activity on episodic memory as AD-related cognition in non-demented older adults.MethodsWe enrolled 196 adults aged between 65 and 90 years, with no dementia. All participants underwent comprehensive clinical assessments including physical activity evaluation and APOE genotyping. The AD-related cognitive domain was assessed by the episodic memory, as the earliest cognitive change in AD, and non-memory cognition for comparative purposes. Overall cognition was assessed by the total score (TS) of the Consortium to Establish a Registry for Alzheimer’s Disease neuropsychological battery.ResultsWe found significant physical activity × age and physical activity × APOE4 interaction effects on episodic memory. Subgroup analyses indicated that an association between physical activity and increased episodic memory was apparent only in subjects aged &gt; 70 years, and in APOE4-positive subjects.ConclusionOur findings suggest that physical activity has beneficial effects on episodic memory, as an AD-related cognitive domain, in individuals aged &gt; 70 years and in APOE4-positive individuals. Physicians should take age and APOE4 status account into when recommending physical activity to prevent AD-related cognitive decline
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