• Title/Summary/Keyword: Biological factors

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Classification of Korean Benthic Macroinvertebrate Types Using the TWINSPAN Clustering and Discriminant Analysis of Environmental Factors Affecting the Distribution of the Types (TWINSPAN 기법을 이용한 한국의 저서성 대형무척추동물의 유형분류 및 유형분포에 영향을 미치는 환경요인에 대한 판별분석)

  • Min, Jeong-Ki;Kim, Dong-Hee;Moon, Jeong-Suk;Kim, Jin-Young;Kong, Dongsoo
    • Journal of Korean Society on Water Environment
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    • v.34 no.6
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    • pp.602-620
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    • 2018
  • Korean benthic macroinvertebrate community from 959 sites and 14 environmental factors that could affect the biological distribution were surveyed and analyzed. The 438 taxa were divided into six groups according to TWINSPAN. Based on the environmental factor values corresponding to each taxon, the average and range of environmental factors for each biological group tended to increase or decrease in eight environmental factors (altitude, slope, current velocity, fraction of fine particles in substrates, turbidity, $BOD_5$, T-N and T-P). As a result of discriminant analysis (hit ratio: 69.6 %), environmental factors that significantly influence the distribution of each biological group were $BOD_5$, altitude, catchment area, T-N, T-P and fraction of fine particles in substrates. The discriminant functions 1 and 2 classified the existing six biological groups (clustered by TWINSPAN) into five (group 1: highland highly sensitive group; group 2: lowland sensitive group, group; 3 and 4: lowland slightly tolerant group; group 5: lowland tolerant group; group 6: lowland highly tolerant group). Most of the benthic macroinvertebrates were identified in the species level. However, a few others were identified in genus or family level, too. Even the organisms belonging to the same genus or family may prefer different environmental factors in the species level, the identification of characteristic of the habitat environment preferred by organism and species level identification of these organisms are utmost. The results of this study may be used as basic information on environmental factors which can be considered in preservation and restoration research for biodiversity.

The Relationships between Benthic Macroinvertebrate and Environmental Factors in Iancheon and Bukcheon Streams, Korea

  • Bae, Mi-Jung;Park, Seon-Min;Kim, Ja-Kyung;Hong, Jeong-Gi;Ryu, Shi Hyun
    • Korean Journal of Ecology and Environment
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    • v.53 no.1
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    • pp.22-30
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    • 2020
  • In this study, we investigated the relationships between benthic macroinvertebrate assemblages and various environmental factors in Iancheon (NIA) and Bukcheon (NBC) streams, Korea. We collected benthic macroinvertebrates and 33 environmental factors in April 2017 at 9 sites (5 sites in NIA and 4 sites in NBC). We identified 93 species(5 phyla, 9 classes, 16 orders, and 53 families) and 69 species(5 phyla, 9 classes, 17 orders, and 47 families) in NIA and NBC streams, respectively. Considering benthic macroinvertebrate index (BMI), NIA (88.2) and NBC (80.2) streams were in "very good" status. Upstream areas showed the highest scores, 95.5 (NIA1) and 94.2 (NBC1), whereas BMI score was the lowest in downstream areas of both streams, especially in NBC4 (51.0 "bad" status). Cluster analysis and non-metric multidimensional scaling analysis represented the differences of benthic macroinvertebrate assemblages according to spatial and anthropogenic gradients. Our findings provide reference data and highlight the need for the continued monitoring to maintain the good status and manage macroinvertebrate diversity in these two streams, in Sangju-si, Korea.

Signaling Molecules at the Conceptus-Uterine Interface during Early Pregnancy in Pigs

  • Seo, Heewon;Choi, Yohan;Shim, Jangsoo;Kim, Mingoo;Ka, Hakhyun
    • Journal of Embryo Transfer
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    • v.27 no.4
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    • pp.211-221
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    • 2012
  • The process of embryo implantation requires physical contact and physiological communication between the conceptus trophectoderm and the maternal uterine endometrium. During the peri-implantation period in pigs, the conceptus undergoes significant morphological changes and secretes estrogens, the signal for maternal recognition of pregnancy. Estrogens secreted from the conceptus act on uterine epithelia to redirect $PGF_2{\alpha}$, luteolysin, secretion from the uterine vasculature to the uterine lumen to prevent luteolysis as well as to induce expression of endometrial genes that support implantation and conceptus development. In addition, conceptuses secrete cytokines, interferons, growth factors, and proteases, and in response to these signals, the uterine endometrium produces hormones, protease inhibitors, growth factors, transport proteins, adhesion molecules, lipid molecules, and calcium regulatory molecules. Coordinated interactions of these factors derived from the conceptus and the uterus play important roles in the process of implantation in pigs. To better understand mechanism of implantation process in pigs, this review provides information on signaling molecules at the conceptus-uterine interface during early pregnancy, including recently reported data reported.

Construction of the Structural Model on Woman Adolescents' Suicidal Ideation based on Developmental Approach Theory of Risk Behavior (위험행동 발달적 접근이론을 적용한 여자 청소년의 자살생각 구조모형 구축)

  • Kwon, Yunhee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.8
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    • pp.3804-3814
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    • 2013
  • This study examined the fitness of a structural model on the relationship among biological risk disposition, sociocultural risk factors, self-control, social support, and suicidal ideation for woman adolescents. Data were collected from December 3, 2012 to March 28, 2013 by questionnaires from 343 middle and high school students in the D metropolitan city. The data was analyzed by the SPSS and AMOS programs. Biological risk disposition, sociocultural risk factors, self-control, and social support showed a direct effect on suicidal ideation for woman adolescents, while biological risk disposition and sociocultural risk factors showed an indirect effect on suicidal ideation for woman adolescents. Biological risk disposition and sociocultural risk factors showed a direct effect on self-control and social support for woman adolescents. Based on the outcomes of this study, it is necessary to design an intervention program that emphasizes the reducement of biological risk disposition, sociocultural risk factors and enhancement self-control and social support in order to prevention woman adolescents' suicidal ideation.

Seasonal Growth Chrateristics of Perennial ryegrass varieties II. Varietal differences in summer growth (Perennial Ryegrass 품종의 계절적 생육특성 II. 여름철 생육의 품종간 차이)

  • 김성규;이주삼;조익환
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.12 no.1
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    • pp.6-11
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    • 1992
  • This experiment was carried out to study the biological yields(BY) of varieties by the developmental growth stages and shoot weight(SHW), leaf area(LA), root dry weight(RW), number of tillers(NT), shoot and root ratio(S/R), weight of a tiller(WT) as factors of yield components with 5 varieties of perennial ryegrass. The results are summarized as follows; 1. The biological yields in summer were about 115 of spring yield. 2. The biological yields of Manhattan were the highest until1 third developmental growth stage among perennial ryegrasses, and those for Maprima and P-2 varieties were the highest in the following stages. In terms of shoot dry weight, the similarly tendency appeared in the fifth developmental growth stage. 3. The shoot dry weight increased highly with the root dry weight. 4. The Tempo variety of biological yield was generally low but the weight of a tiller was the highest. 5. The highest increasing stage of biological yields was between fifth and sixth developmental growth stage, but the lowest increasing stage of biological yields was between first and second developmental growth stage, respectively. The dominant factors of biological yields were influenced to shoot and root dry weight.

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Mechanical and biological complication rates of the modified lateral-screw-retained implant prosthesis in the posterior region: an alternative to the conventional Implant prosthetic system

  • Lee, Jae-Hong;Lee, Jong-Bin;Kim, Man-Yong;Yoon, Joon-Ho;Choi, Seong-Ho;Kim, Young-Taek
    • The Journal of Advanced Prosthodontics
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    • v.8 no.2
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    • pp.150-157
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    • 2016
  • PURPOSE. The modified lateral-screw-retained implant prosthesis (LSP) is designed to combine the advantages of screw- and cement-retained implant prostheses. This retrospective study evaluated the mechanical and biological complication rates of implant-supported single crowns (ISSCs) inserted with the modified LSP in the posterior region, and determined how these complication rates are affected by clinical factors. MATERIALS AND METHODS. Mechanical complications (i.e., lateral screw loosening [LSL], abutment screw loosening, lateral screw fracture, and ceramic fracture) and biological complications (i.e., peri-implant mucositis [PM] and peri-implantitis) were identified from the patients' treatment records, clinical photographs, periapical radiographs, panoramic radiographs, and clinical indices. The correlations between complication rates and the following clinical factors were determined: gender, age, position in the jaw, placement location, functional duration, clinical crown-to-implant length ratio, crown height space, and the use of a submerged or nonsubmerged placement procedure. RESULTS. Mechanical and biological complications were present in 25 of 73 ISSCs with the modified LSP. LSL (n=11) and PM (n=11) were the most common complications. The incidence of mechanical complications was significantly related to gender (P=.018). The other clinical factors were not significantly associated with mechanical and biological complication rates. CONCLUSION. Within the limitations of this study, the incidence of mechanical and biological complications in the posterior region was similar for both modified LSP and conventional implant prosthetic systems. In addition, the modified LSP is amenable to maintenance care, which facilitates the prevention and treatment of mechanical and biological complications.

Creating a Workplace Handbook of Biologically Hazardous Agents (사업장의 생물학적 유해인자 편람 작성 연구)

  • Rim, Kyung-Taek
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.24 no.1
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    • pp.14-37
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    • 2014
  • Objectives: Since information on biological factors in the workplace are currently lacking, I wanted to create a handbook of these factors that would be viewable at a glance as a means to more effectively prevent occupationally-infected diseases. Proper information on biological hazards in the workplace allowing the appropriate recognition of the harmful factors is desperately needed. Methods and Results: In this study, I intended to create a high-utility handbook of biologically hazardous agents in the workplace. To ensure its effectiveness, information and references about biologically hazardous agents in the workplace were analyzed and classified and pathogen safety data sheets(PSDS) sourced from the Public Health Agency of Canada were included. I intended to make it accessible from the point of view of workers and their employers. A more effective classification system of occupational infectious diseases is presented, and biologically hazardous agents were classified according to occupations, industries, infectious diseases, and so on. The handbook consists of 60 major kinds of biologically infectious occupational factors that are expected to be generated in workplaces in Korea, and are focused on practical utility. The pathogen safety data sheets(PSDS) of 192 species were also included. To allow more effective management, domestic and foreign laws and regulations are presented. Conclusions: This case report presents general information on the history and contents of the handbook and PSDS, it will also be useful in workplaces if download from the homepage of OSHRI, KOSHA(oshri.kosha.or.kr/bridge?menuID=901).

Efficient Cloning of the Genes for RNA Polymerase Sigma-like Factors from Actinomycetes

  • Kim, Soon-Ok;Hyun, Chang-Gu;Suh, Joo-Won
    • Journal of Microbiology and Biotechnology
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    • v.8 no.3
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    • pp.280-283
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    • 1998
  • We have cloned the RNA polymerase sigma-like factors from a wide range of actinomycetes by using specific primers with the polymerase chain reaction (PCR). The specific oligonucleotide primers were designed on the basis of amino acid sequences of conserved regions from HrdA, B, D of Streptomyces griseus as well as from the rpoD box of many eubacteria. The consensus sequences were from the rpoD box and helix-turn-helix motif involved in -35 recognition. The designed primers were successfully applied to amplify the DNA fragments of the hrd homolog genes from 8 different strains of actinomycetes which produce a wide variety of important antibiotics. The 480 bp of the DNA fragment was amplified from all 8 strains, and it was identified as a part of hrdA and hrdB as we designed. The deduced amino acid sequence of PCR-amplified DNA fragments were highly homologous to those of other known RNA polymerase sigma factors of S. griseus and Streptomyces aureofaciens. Therefore, this study with specifically designed primers will support rapid cloning of the RNA polymerase sigma factors which recognize different classes of promoters from actinomycetes, and it will also be helpful in understanding the relationship of promoters and sigma factors leading to heterogeneity of RNA polymerases in actinomycetes.

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Theoretical Models of Causative Factors in Depression : A Review of the Literature for Nursing (우울 발생요인에 관한 이론적 고찰)

  • 김수지;고성희
    • Journal of Korean Academy of Nursing
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    • v.19 no.2
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    • pp.173-190
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    • 1989
  • This literature review was undertaken to explore theoretical models of depression for their potential usefulness in nursing research and practice. Depression has bean accounted for by numerous theories or models of causation ; 11 theories selected from psychology, medicine and psychoanalysis and supported by empirical or experimental research were reviewed. These theories identify a variety of precipitating and predisposing factors that may affect the individual's depression. Aggression - turned - inward theory, object loss theory, ego functioning theory, personality organization theory, behavioral theory, learned helplessness theory, cognitive theory, genetic factors, and biological theories conceptualize predisposing factors. Only life stressors theory identifies precipitating facotrs. Each of these theories contributes to an understanding of depression, but many of them use overlapping and interrelated factors. It is also evident from recent. research that there are multiple causes for depression involving an interactive effect among predisposing and precipitating factors that are both biological and psychological in origin. That is, a single theory is not useful, but perhaps a unified theory could be developed that would be helpful to nursing. This review points to the need for continuing development and testing of theories that would integrate the multiple conceptualizations of depression.

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