7,258 research outputs found

    Cytohistological, Physiological, and Nutritional Effects of a Commercial Β-Mannanase Product in Ducklings 1-21 Days of Age

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    Nutritional formula is an economical key factor to raise poultry. β-mannanase breaks the non-starch polysaccharide (NSP) backbone chains in plant-based feed, then NSP is divided into mannose or mannan-oligosaccharide (MOS). Any study about the utilization of MOS or β-mannanase on the ducks was not conducted to our knowledge. This study was performed to evaluate effects of MOS and β-mannanase on the ducks. Effects of MOS supplementation on live performances started to show at d 21. There were no effects by additional YCW-MOS in intestine length, weight, index, and viscosity. However, YCW-MOS showed its effectiveness on gut morphology and cell formation. YCW-MOS only influenced cysteine, histamine, and tryptophan digestibility. β-mannanase showed its effect on live performance throughout the experiment. β-mannanase showed its effectiveness on organ length, viscosity, and gut morphology and cell formation. β-mannanase not only affected amino acid digestibility, but also affected body and bone composition. Titanium (IV) Oxide was used to test the effect of β-mannanase on digesta passage rate. β-mannanase was found to have a great effect on digesta passage rate. Addition of β-mannanase showed faster digesta passage rate because β-mannanase had influenced viscosity and pH of digestive tracts. In conclusion, the β-mannanase influence proved to be more effective than MOS to ducks. This result seems to be due to the fact that MOS is a derivative of β-mannanase. Therefore, the addition of β-mannanase can be an important factor that duck producers must take into account if they want to earn better profit

    Is Foreign Direct Investment Effective From The Perspective Of Tax Avoidance? An Analysis Of Tax Avoidance Through The International Transfer Pricing Behaviors Of Korean Corporations

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    This study examines whether multinational companies carry out tax avoidance through subsidiaries. An empirical analysis was conducted of 4,585 Korean firms from 2001 to 2010 by company and year. The results are as follows. First, MNCs that have become more internationally diversified through the establishment of overseas subsidiaries generally show a higher tendency to avoid tax. Thus, the analysis results show a positive correlation between globally diversified MNCs and corporate tax avoidance. This correlation is established due to the firms' active use of tax strategies (investment tax credits, tax cuts) applicable to the various countries in which they have expanded their businesses. Second, the analysis results showed that these firms actively avoided tax with overseas transfer pricing behaviors when compared to companies without overseas subsidiaries. Thus, the adjustment of sales prices and purchase value through actual transactions increased the propensity of the parent company to avoid tax.

    Statistical Analysis of the Metropolitan Seoul Subway System: Network Structure and Passenger Flows

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    The Metropolitan Seoul Subway system, consisting of 380 stations, provides the major transportation mode in the metropolitan Seoul area. Focusing on the network structure, we analyze statistical properties and topological consequences of the subway system. We further study the passenger flows on the system, and find that the flow weight distribution exhibits a power-law behavior. In addition, the degree distribution of the spanning tree of the flows also follows a power law.Comment: 10 pages, 4 figure

    Anti-aging activities of Pyrus pyrifolia var culta plant callus extract

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    Purpose: To investigate the anti-aging properties of callus extract from Pyrus pyrifolia var. culta with skin regeneration and lightening activities.Methods: Callus extract of P. pyrifolia var. culta was produced on Murashige and Skoog (MS) medium supplemented with picloram, followed by extraction of the callus biomass in phosphate-buffered saline. The anti-oxidant activity of the extract was assessed using the DPPH free radical-scavenging assay. Inhibition of skin pigmentation by callus extract was evaluated by measuring the melanogenesis of melanoma cells. The skin-regenerating efficacy of the extract was evaluated in terms of its ability to promote procollagen synthesis and fibroblast cell proliferation.Results: The callus extract, at 10 mg/mL, exhibited 78.7 % free radical-scavenging activity, equivalent to that exhibited by 500 μM ascorbic acid. The 1 mg/mL extract solution afforded a 1.4-fold greater reduction in melanocyte melanin than did a 1 mg/mL arbutin solution. Fibroblast cells treated with 5 mg/mL callus extract exhibited 127 % higher levels of proliferation and 2.0-fold higher levels of procollagen type I C-peptide synthesis, respectively, compared with the untreated controls.Conclusion: These findings suggest that the callus extract of P. pyrifolia var. culta may be useful as a source of anti-aging cosmetic components with skin lightening and regenerating activities.Keywords: P. pyrifolia var. culta, Anti-aging, Callus extract, Skin lightening, Anti-tyrosinase activity, Melanogenesis, Wound recovery, Procollagen type I C-peptide synthesi

    Proto-type installation of a double-station system for the optical-video-detection and orbital characterisation of a meteor/fireball in South Korea

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    We give a detailed description of the installation and operation of a double-station meteor detection system which formed part of a research & education project between Korea Astronomy Space Science Institute and Daejeon Science Highschool. A total of six light-sensitive CCD cameras were installed with three cameras at SOAO and three cameras at BOAO observatory. A double-station observation of a meteor event enables the determination of the three-dimensional orbit in space. This project was initiated in response to the Jinju fireball event in March 2014. The cameras were installed in October/November 2014. The two stations are identical in hardware as well as software. Each station employes sensitive Watec-902H2 cameras in combination with relatively fast f/1.2 lenses. Various fields of views were used for measuring differences in detection rates of meteor events. We employed the SonotaCo UFO software suite for meteor detection and their subsequent analysis. The system setup as well as installation/operation experience is described and first results are presented. We also give a brief overview of historic as well as recent meteor (fall) detections in South Korea. For more information please consult http://meteor.kasi.re.kr .Comment: Technical/instrumentation description of a professional meteor detection system, 23 pages, 20 figures (color/monochrome), 5 tables, submitted to the Journal of Korean Astronomical Society (JKAS, http://jkas.kas.org/, http://jkas.kas.org/history.html
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