• Title/Summary/Keyword: Biological aspects

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Spatial and Temporal Distribution of Zooplankton in Gwangyang and Sachon Bay, Korea

  • Kim Saywa
    • Korean Journal of Environmental Biology
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    • v.23 no.2 s.58
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    • pp.93-97
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    • 2005
  • Zooplankton dynamics were investigated based on samples collected monthly during the period between November 1998 and October 1999 at 15 stations in Gwangyang and Sachon Bay. Zooplankters were quantitatively collected with horizontal towing through the surface and oblique hauling from the bottom to surface at each station, simultaneously. A total of 88 taxa of zooplankton were distributed and 60 taxa were identified to species. Copepods showed the prosperity in species number of 52 species. Number of taxa occurred in samples hauled obliquely always showed $2\~5$ more species than those captured in the surface except for stations near the Namhae bridge. In waters near Namhae bridge, fast current seemed to mix waters vertically. Seasonally these differences were more distinct in the spring and summer than those in other seasons possibly due to the stratification in warmer seasons. In quantitative aspects, differences between two layers seemed to be obscure. Spatial and temporal variations in species diversity of copepods showed more prosperity in pelagic realm than those in the surface. Our collection carrying out in day time might be one of the important reason to cause these differences in zooplankton dynamics between two layers.

Comparison of interpretation methods for large amplitude oscillatory shear response

  • Kim Hyung-Sup;Hyun Kyu;Kim Dae-Jin;Cho Kwang-Soo
    • Korea-Australia Rheology Journal
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    • v.18 no.2
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    • pp.91-98
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    • 2006
  • We compare FT (Fourier Transform) and SD (Stress Decomposition), the interpretation methods for LAOS (Large Amplitude Oscillatory Shear). Although the two methods are equivalent in mathematics. they are significantly different in numerical procedures. Precision of FT greatly depends on sampling rate and length of data because FT of experimental data is the discrete version of Fourier integral theorem. FT inevitably involves unnecessary frequencies which must not appear in LAOS. On the other hand, SD is free from the problems from which FT suffers, because SD involves only odd harmonics of primary frequency. SD is based on two axioms on shear stress: [1] shear stress is a sufficiently smooth function of strain and its time derivatives; [2] shear stress satisfies macroscopic time-reversal symmetry. In this paper, we compared numerical aspects of the two interpretation methods for LAOS.

Endocrine - Mimicking Phytoestrogens: Health Effects and Signaling

  • Ahn, Hae Sun;Gye, Myung Chan
    • Korean Journal of Environmental Biology
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    • v.22 no.4
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    • pp.479-486
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    • 2004
  • Phytoestrogens display estrogen-like activity because of their structural similarity to human estrogens and exhibit high affinity binding for the estrogen receptors (ERs). The prevalence of phytoestrogens in our diets and the biological effects that they may cause need to be fully examined. ER is the ancestral receptor from which all other steroid receptors have evolved. Although phytoestrogens serve specific signaling functions between the plants and insects, fungi, and bacteria, many chemical signals are often misinterpreted as estrogenic signals in non-target organisms such as vertebrates. There are no ERs in plants or in their most common partners, insects. However, Rhizobium soil bacteria have NodD proteins which is an intended target of phytoestrogen signaling and share genetic homology with the ER. These two evolutionarily distant receptors both recognize and respond to a shared group of chemical signals and ligands, including both agonists and antagonists. This review briefly summarizes estrogen and estrogen receptors, kinds of important phytoestrogens, their health effects as well as some of the evolutionary aspects of mechanism by which phytoestrogen mimics the endogenous ER signaling in our body.

Characteristics of Depression in the Aged People (노년기 우울증의 특징)

  • Park, Jong-Han
    • The Journal of the Korean life insurance medical association
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    • v.20
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    • pp.70-77
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    • 2001
  • Some characteristics of depression in the aged were elucidated. Compared with the previous thoughts, much more attention was given to the biological aspects of depression. However, we have to face up to and solve a variety of enigmas about depression in the aged people. They are:locations and underlying mechanisms in the cerebrum responsible for depression;relationship of senile depression to the presenile one;possible difference(s) between depression with and without psychotic features;possible neurotransmitter differences between senile and presenile depressions. New insights into these areas could bring some lights in the under standing and treatment of depresseion in the aged.

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On a New Evolutionary Algorithm for Network Optimization Problems (네트워크 문제를 위한 새로운 진화 알고리즘에 대하여)

  • Soak, Sang-Moon
    • Journal of the Korean Operations Research and Management Science Society
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    • v.32 no.2
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    • pp.109-121
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    • 2007
  • This paper focuses on algorithms based on the evolution, which is applied to various optimization problems. Especially, among these algorithms based on the evolution, we investigate the simple genetic algorithm based on Darwin's evolution, the Lamarckian algorithm based on Lamark's evolution and the Baldwin algorithm based on the Baldwin effect and also Investigate the difference among them in the biological and engineering aspects. Finally, through this comparison, we suggest a new algorithm to find more various solutions changing the genotype or phenotype search space and show the performance of the proposed method. Conclusively, the proposed method showed superior performance to the previous method which was applied to the constrained minimum spanning tree problem and known as the best algorithm.

Classification of rural villages based on Landscape Indices - Focusing on Landscape Ecological Aspects - (경관지수를 활용한 농촌마을 유형분류: 경관생태학적 접근)

  • Kim, Han-Soo;Oh, Choong-Hyeon
    • Journal of Korean Society of Rural Planning
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    • v.17 no.3
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    • pp.1-13
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    • 2011
  • This study aims to analyse the landscape ecological characteristics of 39 rural villages in Korea and classify them according to their characteristics. After producing a land-use map of rural villages, this study quantified the landscape ecological characteristics of the subject sites as 18 landscape indexes using Fragstats. By applying the landscape index as a variable, selecting 4 factor through principal component analysis and conducting a cluster analysis, it classified them into 3 groups. Rural villages of Korea have their unique types of land-use due to the influence of physical environment such as geography, climate and ecology as well as the social and cultural influence, and the characteristics of land-use can be analysed and classified using the landscape index, the quantified landscape ecological characteristics.

Quantitative Analysis of Nucleic Acids - the Last Few Years of Progress

  • Ding, Chunming;Cantor, Charles R.
    • BMB Reports
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    • v.37 no.1
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    • pp.1-10
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    • 2004
  • DNA and RNA quantifications are widely used in biological and biomedical research. In the last ten years, many technologies have been developed to enable automated and high-throughput analyses. In this review, we first give a brief overview of how DNA and RNA quantifications are carried out. Then, five technologies (microarrays, SAGE, differential display, real time PCR and real competitive PCR) are introduced, with an emphasis on how these technologies can be applied and what their limitations are. The technologies are also evaluated in terms of a few key aspects of nucleic acids quantification such as accuracy, sensitivity, specificity, cost and throughput.

Roles of SUMO in Plants

  • Park, Bong-Soo;Seo, Hak-Soo
    • Journal of Crop Science and Biotechnology
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    • v.11 no.1
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    • pp.1-6
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    • 2008
  • The covalent conjugation of SUMO(Small Ubiquitin-related MOdifier) protein to its substrates regulates numerous cellular processes, including protein stability and activity in eukaryotes as well as in plants. In this present review, we summarize biochemical aspects of SUMO conjugation and deconjugation and the functions of SUMO and sumoylation-related proteins in Arabidopsis and other plants. In particular, we provide an overview of the roles of the SUMO in widely different biological processes including the ABA response, floral induction, pathogen defense, abiotic stresses and hormone signaling. Furthermore, we explore the possible roles of SUMO in embryo and seed development.

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Psychological Factors Affecting Gastrointestinal Disorders : Functional GI Disorders (위장관장애에 영향을 미치는 심리적 요인)

  • Song, Ji-Young
    • Korean Journal of Psychosomatic Medicine
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    • v.6 no.2
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    • pp.210-220
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    • 1998
  • The relationships between emotion, stress and gastro-intestinal dysfunction were briefly reviewed. Until now, several kinds of theories on about pathophysiology, such as motility dysfunction, changes of pain perception on the lumen, dysregulations on the central nervous system associated with psychosocial factors were reported. However, none of those factors could'nt give any clues for the causes of the functional bowel disorders. For understanding the meaning of the symptoms and for the treatment approach, clinicians should give attention to the comprehensive point of view, i.e., not only biological but also psychological aspects of the patients with non-organic bowel dysfunctions. Giving warm and kind explanations to the patient about symptom formation and progression and understanding the patient's illness behaviors, and good and strong doctor-patient relationship is essentials for the treatment.

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A Study on the Characteristics of Tuberculosis Control System Using Markov Processes (마르코프 과정을 이용한 결핵 관리 특성에 관한 연구)

  • Chong, Hyeng-Hwan;Joo, Soo-Won;Kim, Hae-Jae
    • Journal of Biomedical Engineering Research
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    • v.9 no.2
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    • pp.159-164
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    • 1988
  • This thesis investigates the Quantitative aspect of epidemic phenomena utilizing the analytical method of discrete time systeMs based on the theory of Markov processes. In particular, the pattern on the epidemic character of turberculosis controlled by prophylaxis and BCG vaccinatioll was analyzed by the markovian model of tuberculosis system which is derived according to the ecologic relationship between nine epidemiologic states of individuals. The quantitative aspects of the model were characterized by digital computer simulations.

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