• Title/Summary/Keyword: Z-Factor

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The Fish Fauna and Population of Zacco koreanus in the Upper Region of the Gapyeong Stream (가평천 상류역의 어류상과 참갈겨니의 개체군 특징)

  • Choi, Jun-Kil;Jang, Chang-Ryeol;Byeon, Hwa-Kun
    • Korean Journal of Environment and Ecology
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    • v.25 no.1
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    • pp.65-70
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    • 2011
  • The fish fauna and population of Zacco koreanus in the upper region of the Gapyeong Stream was investigation from April, 2005 to August, 2009. The collected species during the survey period were 16 species belonging to 6 families. Dominant species was Z. koreanus and subdominant species was Pungtungia herzi. korea endemic species were Pseudopungtungia tenuicorpa, Coreoleuciscus splendidus, Hemibarbus mylodon, Gobiobotia brevibarba, Microphysogobio longidorsalls, Z. koreanus, Koreocobitis rotundicaudata, Iksookimia koreensis, Silorus microdorsalis, Liobagrus andersoni, Coreoperca herzi and Odontobutis platycephala, which showed a ratio of 75 % in all collected species. The species of H. mylodon was identified as natural monument, and P. tenuicorpa and G. brevibarba were endangered species. Length-weight relationship in the population of Z. koreanus was 3.44, and condition factor in the popuation was 0.004. The spawning season of Zacco koreanus was May and June.

Solution for a semi-infinite plate with radial crack and radial crack emanating from circular hole under bi-axial loading by body force method

  • Manjunath, B.S.;Ramakrishna, D.S.
    • Interaction and multiscale mechanics
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    • v.2 no.2
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    • pp.177-187
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    • 2009
  • Machine or structural members subjected to fatigue loading will have a crack initiated during early part of their life. Therefore analysis of members with cracks and other discontinuities is very important. Finite element method has enjoyed widespread use in engineering, but it is not convenient for crack problems as the region very close to crack tip is to be discretized with very fine mesh. However, as the body force method (BFM), requires only the boundary of the discontinuity (crack or hole) to be discretized it is easy versatile technique to analyze such problems. In the present work fundamental solution for concentrated load x + iy acting in the semi-infinite plate at an arbitrary point $z_0=x_0+iy_0$ is considered. These fundamental solutions are in complex form ${\phi}(z)$ and ${\psi}(z)$ (England 1971). These potentials are known as Melan potentials (Ramakrishna 1994). A crack in the semi-infinite plate as shown in Fig. 1 is considered. This crack is divided into number of divisions. By applying pair of body forces on a division, the resultant forces on the remaining 'N'divisions are to be found for which ${\phi}_1(z)$ and ${\psi}_1(z)$ are derived. Body force method is applied to calculate stress intensity factor for crack in semi-infinite plate. Also for the case of crack emanating from circular hole in semi-infinite plate radial stress, hoop stress and shear stress are calculated around the hole and crack. Convergent results are obtained by body force method. These results are compared with FEM results.

Association between body mass index and hepatitis B antibody seropositivity in children

  • Kwon, Yoowon;Jeong, Su Jin
    • Clinical and Experimental Pediatrics
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    • v.62 no.11
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    • pp.416-421
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    • 2019
  • Background: The seropositivity rate of hepatitis B surface antigen (anti-HBs) antibodies is known to be ≥95% after hepatitis B virus vaccination during infancy. However, a low level or absence of anti-HBs in healthy children is discovered in many cases. Recent studies in adults reported that a reduced anti-HBs production rate is related to obesity. Purpose: To investigate whether body mass index (BMI) affects anti-HBs levels in healthy children following 3 serial dose vaccinations in infancy. Methods: We recruited 1,200 healthy volunteers aged 3, 5, 7, or 10 years from 4-day care centers and 4 elementary schools. All subjects completed a questionnaire including body weight, height, and vaccine type received. Levels of serum hepatitis B surface antigen (HBsAg) and anti-HBs in all subjects were analyzed using electrochemiluminescence immunoassay. The standardized scores (z score) for each sex and age were obtained using the lambda-mu-sigma method in the 2017 Korean National Growth Charts for children and adolescents. Results: Our subjects (n=1,200) comprised 750 males (62.5%) and 450 females (37.5%). The overall anti-HBs seropositivity rate was 57.9% (695 of 1,200). We identified significant differences in mean BMI values between seronegative and seropositive groups (17.45 vs. 16.62, respectively; P<0.001). The anti-HBs titer was significantly decreased as the BMI z score increased adjusting for age and sex (B=-15.725; standard error=5.494; P=0.004). The probability of anti-HBs seropositivity based on BMI z score was decreased to an OR of 0.820 after the control for confounding variables (95% confidence interval, 0.728-0.923; P=0.001). Conclusion: There was a significant association between anti-HBs titer and BMI z score after adjustment for age and sex. Our results indicate that BMI is a potential factor affecting anti-HBs titer in healthy children.

Thymosin Beta4 Regulates Cardiac Valve Formation Via Endothelial-Mesenchymal Transformation in Zebrafish Embryos

  • Shin, Sun-Hye;Lee, Sangkyu;Bae, Jong-Sup;Jee, Jun-Goo;Cha, Hee-Jae;Lee, You Mie
    • Molecules and Cells
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    • v.37 no.4
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    • pp.330-336
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    • 2014
  • Thymosin beta4 (TB4) has multiple functions in cellular response in processes as diverse as embryonic organ development and the pathogeneses of disease, especially those associated with cardiac coronary vessels. However, the specific roles played by TB4 during heart valve development in vertebrates are largely unknown. Here, we identified a novel function of TB4 in endothelial-mesenchymal transformation (EMT) in cardiac valve endocardial cushions in zebrafish. The expressions of thymosin family members in developing zebrafish embryos were determined by whole mount in situ hybridization. Of the thymosin family members only zTB4 was expressed in the developing heart region. Cardiac valve development at 48 h post fertilization was defected in zebrafish TB4 (zTB4) morpholino-injected embryos (morphants). In zTB4 morphants, abnormal linear heart tube development was observed. The expressions of bone morphogenetic protein (BMP) 4, notch1b, and hyaluronic acid synthase (HAS) 2 genes were also markedly reduced in atrio-ventricular canal (AVC). Endocardial cells in the AVC region were stained with anti-Zn5 antibody reactive against Dm-grasp (an EMT marker) to observe EMT in developing cardiac valves in zTB4 morphants. EMT marker expression in valve endothelial cells was confirmed after transfection with TB4 siRNA in the presence of transforming growth factor ${\beta}$ ($TGF{\beta}$) by RT-PCR and immunofluorescent assay. Zn5-positive endocardial AVC cells were not observed in zTB4 morphants, and knockdown of TB4 suppressed TGF-${\beta}$-induced EMT in ovine valve endothelial cells. Taken together, our results demonstrate that TB4 plays a pivotal role in cardiac valve formation by increasing EMT.

An Image Evaluation According to the Constituent Elements of Skirt Designs in Modern Men's Fashion - Focusing on Gwangju City's Generation Z Male and Female College Students - (현대 남성패션에 나타난 스커트 디자인의 구성적 요소에 따른 이미지 평가 - 광주광역시 Z세대 남녀 대학생을 중심으로 -)

  • Yang, Hyo-Jung
    • Fashion & Textile Research Journal
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    • v.23 no.2
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    • pp.159-173
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    • 2021
  • This study attempted to investigate the perspective of the skirts of male and female students by analyzing the differences in image evaluation according to the constituent elements (type, length, and wearing method) of men's skirt designs in modern fashion. The study included 109 male and female college students from Generation Z residing or whose life center was in Gwangju Metropolitan City, to evaluate 12 images depicting types of men's skirts. First, the constituent image evaluation factors according to the constituent design elements of men's skirts were analyzed. Second, the differences in each constituent image evaluation factor based on the constituent design elements of men's skirt designs were analyzed. Third, the gender-based differences in image evaluation by men and women concerning the constituent design elements of men's skirt designs were analyzed. The analysis included relatively more women than men. The results of the image recognition dimension included the following categories: "attractive image," "evaluable image," "gender image," and "personality image." In modern fashion, skirts are used to express the diverse personalities of men's fashion. Thus, they are used beyond the stereotype of women's clothing, toward expanding and diversifying the image of men's clothing through mixing and creating a dichotomous image of men and women. It can be used as a design that suggests a gender-fluid image.

Platycarya strobilacea S. et Z. Extract Has a High Antioxidant Capacity and Exhibits Hair Growth-promoting Effects in Male C57BL/6 Mice

  • Kim, Eun Jin;Choi, Joo Yeon;Park, Byung Cheol;Lee, Bog-Hieu
    • Preventive Nutrition and Food Science
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    • v.19 no.3
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    • pp.136-144
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    • 2014
  • This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. This study was conducted to evaluate the effects of Platycarya strobilacea S. et Z. (PSE) extract on mouse hair growth and to determine the mechanism of action of PSE. PSE was purchased and its antioxidant activities, such as electron donating ability, total polyphenol content, and flavonoid content were tested. Toxicity during topical treatment was determined by the CCK-8 assay, a cell viability test. Fifteen 4-week-old male C57BL/6 mice were assigned to receive one of three treatments: dimethyl sulfoxide (negative control), minoxidil (positive control) or PSE. Test materials were topically applied to the shaved dorsal skin of each mouse daily for 3 weeks. After 21 days, we observed skin tissue hair follicle morphology and length, mast cell number, and stem cell factor (SCF) expression using hematoxylin and eosin (H&E), toluidine blue, and immunohistochemical staining, respectively. Furthermore, the expression of cytokines involved in hair growth [i.e., insulin-like growth factor (IGF)-1, keratinocyte growth factor (KGF), and transforming growth factor (TGF)-${\beta}1$] was determined by PCR. PSE was found to have very high antioxidant activity. The cell viability rate of PSE-treated mice was markedly higher than that of mice in the control group. We also observed an increase in hair follicle length, strong SCF staining, and a decrease in mast cell number in the PSE group. In addition, PSE-treated mice had higher IGF-1 and KGF expression and lower TGF-${\beta}1$ expression than mice in the minoxidil-treated group. These results suggest that topical application of PSE promotes hair growth by intensifying SCF, suppressing mast cell production, and increasing hair growth-promoting cytokine expression.

Induction of Spontaneous Neutrophil Apoptosis by 4-O-Methyl-Ascochlorin, A Prenyl Phenol Compound (프레닐 페놀계 항생제인 4-O-methyl-ascochlorin에 의한 호중구 세포사멸의 유도)

  • Son Dong-Aoon;Lee Sun-Young;Lee Min-Jung;Park Joo-In;Hong Young-Seob;Lee Yong-Hwan;Chang Young-Chae;Kwak Jong-Young
    • Journal of Life Science
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    • v.16 no.1
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    • pp.30-36
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    • 2006
  • Neutrophils are short-lived leukocytes that play a vital role in immune responses to bacteria, yeast, and fungi. This study was performed to investigate the effect of 4-O-methyl-ascochlorin (MAC), an anti-tumor, antibiotic, and anti-fungal prenyl-phenol compound on the spontaneous apoptosis of human neutrophils. MAC time- and dose-dependently accelerated the spontaneous apoptosis of human neutrophils. The effect of MAC on neutrophil apoptosis was blocked by pre-treatment of the neutrophils with specific inhibitors of pancaspase (zVAD-fmk), caspase-8 (zIETD-fmk), or caspase-3 (zDEVD-fmk). The cleavage of procaspase-8 and procaspase-3 was increased by MAC. Mitochondrial permeability, which was measured by the retention of $DiOC_6(3)$, was dose-de-pendently increased by MAC but the change of mitochondrial permeability was not blocked by pretreatment of neutrophils with zIETD-fmk. These results suggest that MAC induces neutrophil apoptosis by caspase-8-dependent but mitochondria-independent manner.

The Analysis of the Ship's Maneuverability According to the Ship's Trim and Draft (선박 TRIM변화에 따른 조종성능의 분석)

  • PARK, Byung-Soo;KANG, Donghoon;KANG, Il-Kwon;KIM, Hyun-Mu
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.6
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    • pp.1865-1871
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    • 2015
  • Ship's trim is the one of the most important factor for safety at the sea. Turning circle test and Z-test were carried out to find the effect of ship's trim and draft changes. The results are as follows. 1. If the ship's draft and trim became large, turning circle would be wide. 2. If the ship's draft and trim became large, ship's drift angle would be small. Small drift angle made wide turning circle. 3. Trim by the head made slow ship's final speed when turning circle test. 4. By Z-test, the deeper draft and trim by the stern made small OSA. Small OSA means strong ship's stability. 5. Totally 2nd OSA is smaller than 1st OSA on Z-test. 6. There were small differences of 2nd OSA in trim by the stern, but there were large OSA in trim by the head. 7. The larger trim by the stern, the smaller OSW. The small OSW means better ship's stability and maneuverability.

Effects of the Essential Oil Components from Ligusticum chuanxiong on Proinflammatory Mediators of RAW264.7 Macrophage Cells

  • Lim, Hye-Rim;Shin, Seung-Won
    • Natural Product Sciences
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    • v.16 no.4
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    • pp.259-264
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    • 2010
  • The essential oil fraction was obtained from the underground parts o of Ligusticum chuanxiong (Umbelliferae) by steam distillation, and its main components, Z-ligustilide and butylidene phthalide, were isolated by column chromatography. Its essential oil fraction and the isolated main components were examined for effects on their anti-inflammatory properties in RAW 264.7 macrophage cells to develop a new natural anti-inflammatory drug. The results showed that the L. chuanxiong essential oil fraction and its main components, Z-ligustilide and butylidene phthalide, inhibited the production of nitric oxide significantly in lipopolysaccharide (LPS)-treated RAW 264.7 cells. LPS-induced interleukin-$1{\beta}$ (IL-$1{\beta}$), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-$\alpha$) production was also decreased in a dose-dependent manner. In addition, western blot analysis revealed that the L. chuanxiong essential oil fraction and also its main components, Z-ligustilide, and butylidene phthalide reduced the expression levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS).

INJECTIVE PROPERTY RELATIVE TO NONSINGULAR EXACT SEQUENCES

  • Arabi-Kakavand, Marzieh;Asgari, Shadi;Tolooei, Yaser
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.2
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    • pp.559-571
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    • 2017
  • We investigate modules M having the injective property relative to nonsingular modules. Such modules are called "$\mathcal{N}$-injective modules". It is shown that M is an $\mathcal{N}$-injective R-module if and only if the annihilator of $Z_2(R_R)$ in M is equal to the annihilator of $Z_2(R_R)$ in E(M). Every $\mathcal{N}$-injective R-module is injective precisely when R is a right nonsingular ring. We prove that the endomorphism ring of an $\mathcal{N}$-injective module has a von Neumann regular factor ring. Every (finitely generated, cyclic, free) R-module is $\mathcal{N}$-injective, if and only if $R^{(\mathbb{N})}$ is $\mathcal{N}$-injective, if and only if R is right t-semisimple. The $\mathcal{N}$-injective property is characterized for right extending rings, semilocal rings and rings of finite reduced rank. Using the $\mathcal{N}$-injective property, we determine the rings whose all nonsingular cyclic modules are injective.