• 제목/요약/키워드: Bursa

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순무 모자이크 바이러스(TuMV)의 새로운 기주식물 탐색 (New Host Plants of Turnip Mosaic Potyvirus in Korea)

  • 최준근;윤주연;이세원;최장경
    • 한국식물병리학회지
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    • 제14권6호
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    • pp.625-629
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    • 1998
  • Turnip mosaic potyviruses (TuMV) were isolated from Rorippa indica and Armoracia lapathifolia showing mosaic symptoms in field. Identification of the TuMVs were carried out by host reactions of indicator plants, electron micrograph, serological properties and reverse transcription-poly-merase chain reaction (RT-PCR). Both viruses systemically infected Chenopodium quinoa, Nicotiana clevelandii, Brassica rapa, B. campestris subsp. pekinensis, B. juncea and Raphanus sativus, and developed local infection on inoculated leaves of C. quinoa, C. amaranticola, C. album, N. tabacum cv. Xanthi nc and Gomphrena grobosa. However, the viruses did not infect on N. glutinosa, Cucumis sativus and Vigna unguiculata. The filamentous particles, about 720 nm in length, and inclusion bodies were observed from the infected leaf tissues by dipping on electron microscopy. Crude sap of leaf infected with the viruses was reacted positively with an antiserum of TuMV in agar gel double diffusion. For detection of the viruses, RT-PCR was carried out with TuMV--specfic oligonucleotide primer. The RT-PCR products, a 1,092 bp DNA fragment, were obtained from naturally infected leaves of R. indica and A. lapathifolia. In inoculation test to seven cruciferous weeds with TuMV, infection occurred in Arabis glabra, Barbarea orthoceras, Capsella bursa-pastoris, Draba nomorosa var. hebecarpa, Rorippa cantoniensis and Thlaspi arvense.

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Investigation on the Functional Properties of Chestnut Flours and Their Potential Utilization in Low-fat Cookies

  • Inkaya, Ayse N.;Gocmen, Duygu;Ozturk, Serpil;Koksel, Hamit
    • Food Science and Biotechnology
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    • 제18권6호
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    • pp.1404-1410
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    • 2009
  • Chestnut flours (CFs) were produced from 3 chestnut samples (Aydin, Kutahya, and Bursa) by 2 different methods (boiled and oven-dried: BOD-CF and freeze-dried: FD-CF). Functional properties and effects of CF addition (10, 20, and 30%) on the qualities of regular and low-fat cookie were investigated. The freeze drying significantly increased water solubility of CFs but decreased their water binding capacity. The emulsion capacity and stability of FD-CFs were higher than those of BOD-CFs. At pH 4, 6, 8, and 10 FD-CFs had better gelation properties. Spread ratio (SR) values of BOD-CF supplemented regular or low-fat cookies decreased with increasing CF levels. Hardness values of CF supplemented regular cookies were generally lower compared to control. SR and hardness values of FD-CF supplemented cookies were higher than those of BOD-CF supplemented ones. Surface colors of the cookies were darker with FD-CF addition as compared to BODCF addition. In low-fat cookies, the sample supplemented with 10% Kutahya FD-CF had the highest taste-flavor value. FDCF supplementation generally resulted in higher appearance and taste-flavor scores than BOD-CF supplementation in cookies.

Intestinal Flukes Recovered from a Herring Gull, Larus argentatus, in the Republic of Korea

  • Lee, Young-Il;Seo, Min;Chai, Jong-Yil
    • Parasites, Hosts and Diseases
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    • 제58권1호
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    • pp.81-86
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    • 2020
  • Trematode specimens were collected from the intestine of a herring gull, Larus argentatus, which was found in a critical condition on the shore of a small island (Yubu-do, Seocheon-gun, Chungcheongnam-do) located at the western coast of the Korean peninsula. Total 11 specimens of intestinal flukes, including 3 Cryptocotyle lingua (Heterophyidae), 1 Himasthla alincia (Echinostomatidae), 5 Cardiocephaloides medioconiger (Strigeidae), and 2 Diplostomum spathaceum (Diplostomidae), were recovered. C. lingua was morphologically characterized by the presence of a large ventrogenital apparatus and 2 obliquely tandem testes. H. alincia had an elongated body and a head collar equipped with 31 collar spines. C. medioconiger had a bisegmented body and a voluminous copulatory bursa containing the seminal vesicle and ejaculatory duct. D. spathaceum also had a bisegmented body and its vitellaria extended up to the anterior border of the tribocytic organ. It is of note that C. lingua is potentially zoonotic that can occur in birds and humans. Three of them, i.e., C. lingua, C. medioconiger, and D. spathaceum, are new trematode fauna in Korea. Studies on trematode fauna of migratory birds should be continued in Korea.

백서에서 Serine Protease 억제제가 난포성숙에 미치는 영향에 대한 연구 (Effect of Serine Protease Inhibitor on Follicular Development in the Rat Ovary)

  • 윤병구;이진용
    • Clinical and Experimental Reproductive Medicine
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    • 제20권1호
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    • pp.19-29
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    • 1993
  • Plasminogen activator (PA)-plasmin system in follicular fluid is involved in the process leading to follicular rupture at ovulation. It is well known that PA is closely associated with cellular differentiation and tissue remodeling on evidences from the study of normal and malignant tissues. This study was designed to ascertain a potential role of PA in the ovarian folliculogenesis. Immature Sprague-Dawley rats were injected with pregnant mare serum gonadotropin, followed by injection of serine protease inhibitor (SPI; mixture of 1 mol/L benzamidine and 1 mol/L amino-caproic acid) into the unilateral ovarian bursa. In the control study, mechanical effect of bursal injection and contralateral ovarian effect SPI were ruled out. Total antral follicular areas relative to total ovarian cross-sectional areas was siginificantly lower in SPI-injected ovary than in saline-injected ovary. SPI injection decreased the relative antral follicular area by 33 % respectively. Electron microscopic finding of granulosa cell in the atretic follicle showed the presence of pyknotic nucleus, blurring of neucleolemma, degeneration of mitochondria and dilation of endoplasmic reticulum. After induction of ovulation with hCG, the number of oocytes released was significantly decreased in SPI-injected oviduct than in saline-injected oviduct. From above results, author discussed that PA may play a role not only in ovulation but also in some processes of folliculogenesis.

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Analytical solutions for static bending of edge cracked micro beams

  • Akbas, Seref Doguscan
    • Structural Engineering and Mechanics
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    • 제59권3호
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    • pp.579-599
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    • 2016
  • In this study, static bending of edge cracked micro beams is studied analytically under uniformly distributed transverse loading based on modified couple stress theory. The cracked beam is modelled using a proper modification of the classical cracked-beam theory consisting of two sub-beams connected through a massless elastic rotational spring. The deflection curve expressions of the edge cracked microbeam segments separated by the rotational spring are determined by the Integration method. The elastic curve functions of the edge cracked micro beams are obtained in explicit form for cantilever and simply supported beams. In order to establish the accuracy of the present formulation and results, the deflections are obtained, and compared with the published results available in the literature. Good agreement is observed. In the numerical study, the elastic deflections of the edge cracked micro beams are calculated and discussed for different crack positions, different lengths of the beam, different length scale parameter, different crack depths, and some typical boundary conditions. Also, the difference between the classical beam theory and modified couple stress theory is investigated for static bending of edge cracked microbeams. It is believed that the tabulated results will be a reference with which other researchers can compare their results.

Involvement of Board Chairmen in Audit Committees and Earnings Management: Evidence from Malaysia

  • AL-ABSY, Mujeeb Saif Mohsen;ISMAIL, Ku Nor Izah Ku;CHANDREN, Sitraselvi;AL-DUBAI, Shehabaddin Abdullah A.
    • The Journal of Asian Finance, Economics and Business
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    • 제7권8호
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    • pp.233-246
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    • 2020
  • This paper investigates the effect of the involvement of the board chairman in the audit committee (AC) on earnings management (EM). It examines Bursa Malaysia-listed companies with the lowest positive earnings for the years 2013 to 2015. The Modified Jones Model by Kasznik (1999) was used to determine discretionary accruals. An AC that includes its board chairman as an ordinary member is associated with greater discretionary accruals. However, a board chairman who is also the chairman of the AC does not seem to influence discretionary accruals. This paper supports the agency theory and policy-makers' efforts to prevent board chairmen from sitting on ACs. It is the first study that uses the agency theory to describe the association between the board chairman's involvement in the both AC and EM. This study alerts policy-makers, stakeholders and researchers to the influence of a board chairman serving on the AC in curbing EM. Furthermore, it provides empirical evidence that the majority of Malaysian companies whose board chairmen are involved in the AC appoint the chairman as an ordinary member of the AC. This indicates that executive directors may affect such actions. Hence, more policies are needed to improve AC independence.

전염성 F낭병에 대한 혈청학적 연구 (The serological studies on infectious bursal disease)

  • 정영미;서석열;도홍기;조정곤;노수일
    • 한국동물위생학회지
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    • 제23권3호
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    • pp.271-279
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    • 2000
  • This study was carried out to provide the fundamental information for development of proper vaccination program against infectious bursal disease(IBD) to the local chicken farms. The antigen detection was peformed from 8 samples of bursa of Fabricius with agar gel precipitation(AGP) and indirect immunofluorescent assay(IFA), And also, the antibodies in serum samples were detected by the various serological methods such as commercial ELISA assay, AGP and virus neutralization(VN) test. 1. The antigen detection rates were 25% for AGP which is 2 out of 8 farms and 10 out of 40 bursas, and 25% which Is 2 out of 8 farms and 20% 8 out of 40 bursas for IFA, respectively. 2. The mean titer of maternal antibody (>3,000) existed until 10 days of the age with ELISA-GMT. 3. The antibody positive rates which are over 80% showed until 5 days of the age with ELISA and at 10 days of the age with AGP except one, but none of them showed from 1 day of the age. This report came to conclusions that both the protective maternal antibody titers and the antigen positive rates were significant until at the 10 days of the age.

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Large deflection analysis of edge cracked simple supported beams

  • Akbas, Seref Doguscan
    • Structural Engineering and Mechanics
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    • 제54권3호
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    • pp.433-451
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    • 2015
  • This paper focuses on large deflection static behavior of edge cracked simple supported beams subjected to a non-follower transversal point load at the midpoint of the beam by using the total Lagrangian Timoshenko beam element approximation. The cross section of the beam is circular. The cracked beam is modeled as an assembly of two sub-beams connected through a massless elastic rotational spring. It is known that large deflection problems are geometrically nonlinear problems. The considered highly nonlinear problem is solved considering full geometric non-linearity by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. There is no restriction on the magnitudes of deflections and rotations in contradistinction to von-Karman strain displacement relations of the beam. The beams considered in numerical examples are made of Aluminum. In the study, the effects of the location of crack and the depth of the crack on the non-linear static response of the beam are investigated in detail. The relationships between deflections, end rotational angles, end constraint forces, deflection configuration, Cauchy stresses of the edge-cracked beams and load rising are illustrated in detail in nonlinear case. Also, the difference between the geometrically linear and nonlinear analysis of edge-cracked beam is investigated in detail.

Analysis of R/C frames considering cracking effect and plastic hinge formation

  • Kara, Ilker Fatih;Ashour, Ashraf F.;Dundar, Cengiz
    • Structural Engineering and Mechanics
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    • 제63권5호
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    • pp.669-681
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    • 2017
  • The design of reinforced concrete buildings must satisfy the serviceability stiffness criteria in terms of maximum lateral deflections and inter story drift in order to prevent both structural and non-structural damages. Consideration of plastic hinge formation is also important to obtain accurate failure mechanism and ultimate strength of reinforced concrete frames. In the present study, an iterative procedure has been developed for the analysis of reinforced concrete frames with cracked elements and consideration of plastic hinge formation. The ACI and probability-based effective stiffness models are used for the effective moment of inertia of cracked members. Shear deformation effect is also considered, and the variation of shear stiffness due to cracking is evaluated by reduced shear stiffness models available in the literature. The analytical procedure has been demonstrated through the application to three reinforced concrete frame examples available in the literature. It has been shown that the iterative analytical procedure can provide accurate and efficient predictions of deflections and ultimate strength of the frames studied under lateral and vertical loads. The proposed procedure is also efficient from the viewpoint of computational time and convergence rate. The developed technique was able to accurately predict the locations and sequential development of plastic hinges in frames. The results also show that shear deformation can contribute significantly to frame deflections.

Damped dynamic responses of a layered functionally graded thick beam under a pulse load

  • Asiri, Saeed A.;Akbas, Seref D.;Eltaher, Mohamed A.
    • Structural Engineering and Mechanics
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    • 제75권6호
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    • pp.713-722
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    • 2020
  • This article aims to illustrate the damped dynamic responses of layered functionally graded (FG) thick 2D beam under dynamic pulse sinusoidal load by using finite element method, for the first time. To investigate the response of thick beam accurately, two-dimensional plane stress problem is assumed to describe the constitutive behavior of thick beam structure. The material is distributed gradually through the thickness of each layer by generalized power law function. The Kelvin-Voigt viscoelastic constitutive model is exploited to include the material internal damping effect. The governing equations are obtained by using Lagrange's equations and solved by using finite element method with twelve -node 2D plane element. The dynamic equation of motion is solved numerically by Newmark implicit time integration procedure. Numerical studies are presented to illustrate stacking sequence and material gradation index on the displacement-time response of cantilever beam structure. It is found that, the number of waves increases by increasing the graduation distribution parameter. The presented mathematical model is useful in analysis and design of nuclear, marine, vehicle and aerospace structures those manufactured from functionally graded materials (FGM).