• Title/Summary/Keyword: biological phenomena

Search Result 203, Processing Time 0.031 seconds

STATISTICAL PHYSICS APPROACH TO BIOLOGICAL PHENOMENA

  • Sung, Wokyng
    • Proceedings of the Korean Biophysical Society Conference
    • /
    • 1996.07a
    • /
    • pp.7-7
    • /
    • 1996
  • A new trend that emerges at the turn of the century is the physical approach to biological phenomena. It is expected that biology provides novel materials for condensed matter physics and, most importantly, a revolutionary paradigm for physics at large. On the other hand, physics, if properly extended, is expected to provide systematic and quantitative understanding of biological phenomena, and multitude of biotechnological applications. (omitted)

  • PDF

A study on the Modeling of Nonlinear Properties of Biological Signal using Genetic Programming (유전자 프로그래밍을 이용한 생체 신호의 비선형 특성 모델링에 관한 연구)

  • Kim, Bo-Yeon;Park, Kwang-Suk
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1996 no.11
    • /
    • pp.70-73
    • /
    • 1996
  • Many researchers had considered biological systems as linear systems. In many cases of biological systems, the phenomena that show the regular and periodic dynamics are considered the normal state. However, some clinical experiments reported, in some cases, the periodic signals represented the abnormal state. We assume that signals from human body system are generated from deterministic, intrinsic mechanisms and can be represented a simple equation that show nonlinear dynamics dependent on control parameters. The objective of our study is to model a nonlinear dynamics correctly from the nonlinear time series using the genetic programming method; to find a simple equation of nonlinear dynamics using collected time series and its nonlinear characteristics. We applied genetic programming to model RR interval of ECG that shows chaotic phenomena. We used 4 statistic measures and 2 fractal measures to estimate fitness of each chromosome, and could obtain good solutions of which chaotic features are similar.

  • PDF

The Syncronization Phenomena and Its Model of Myocardial Cells (심근세포의 동기현상과 그 모델화)

  • 박민용;제승정남
    • Journal of Biomedical Engineering Research
    • /
    • v.3 no.2
    • /
    • pp.101-104
    • /
    • 1982
  • Even one embryonic myocardial cell exhibits a spontaneous, periodic beating phenomena. When these cells come in contact with each other, they beat synchronously with a certain period. In this paper, the mechanism of this phenomena is investigated, and the synchronization model is presented. The physiological experimental results are compared with the simulated results of the model.

  • PDF

Investigation of Corrosion Fatigue Phenomena in Transient Zone and Preventive Coating and Blade Design against Fouling and Corrosive Environment for Mechanical Drive Turbines

  • Hata, Satoshi;Nagai, Naoyuki;Yasui, Toyoaki;Tsukamoto, Hiroshi
    • International Journal of Fluid Machinery and Systems
    • /
    • v.1 no.1
    • /
    • pp.121-139
    • /
    • 2008
  • For mechanical drive steam turbines, the investigation results of corrosion fatigue phenomena in the transient zone are introduced, including basic phenomena on expansion line and actual design and damage experience. These results were analyzed from the standpoint of stress intensity during the start of cracking. In order to resolve such problems, preventive coating and blade design methods against fouling and corrosive environments are developed. Detailed evaluation test results are given for coating performance using a unique test procedure simulating fouling phenomena and washing conditions. Finally, the results of the successful modification of internals and on-line washing results on site are introduced.

Autophagy-Is it a preferred route for lifespan extension?

  • Dwivedi, Meenakshi;Ahnn, Joo-Hong
    • BMB Reports
    • /
    • v.42 no.2
    • /
    • pp.65-71
    • /
    • 2009
  • Autophagy, which is a process of self eating, has gained interest in the past decade due to its both beneficial and controversial roles in various biological phenomena. The discovery of autophagy genes (ATG) in yeast has led to focused research designed to elucidate the mechanism and regulation of this process. The role of autophagy in a variety of biological phenomena, including human disease, is still the subject of debate. However, recent findings suggest that autophagy is a highly regulated process with both beneficial and negative effects. Indeed, studies conducted using various model organisms have demonstrated that increased autophagy leads to an extended lifespan. Despite these findings, it is still unknown if all pathways leading to extended lifespan converge at the process of autophagy or not. Here, an overview of modern developments related to the process of autophagy, its regulation and the molecular machinery involved is presented. In addition, this review focuses on one of the beneficial aspects of autophagy, its role in lifespan regulation.

The Biologists' Boon Activation Patterns during the Generation of Scientific Questions on Biological Phenomena (생명현상에 관한 과학적 의문 생성 과정에서 나타나는 생물학자의 두뇌 활성 양상)

  • Kwon, Yong-Ju;Jeong, Jin-Su;Lee, Jun-Ki;Yang, Il-Ho
    • Journal of The Korean Association For Science Education
    • /
    • v.27 no.1
    • /
    • pp.84-92
    • /
    • 2007
  • The purpose of this study was to investigate biologists' brain activation patterns during the generation of scientific questions on biological phenomena. Eight right-handed healthy biologists volunteered to be participants in the present study. The question-generation tasks were presented in a block design. The BOLD signals of the biologists' brain were measured by 3.0T fMRI system and data were analyzed using Statistical Parametric Mapping (SPM2). According to our results, the left inferior and middle frontal gyri, the medial prefrontal cortex, the bilateral hippocampus, the occipito-parietal route, the fusiform gyrus, and the cerebellum were activated significantly during the generation of scientific questions. Therefore, we suggested that generating scientific question is associated with analyzing observed situations, using verbal strategy, retrieving episodic memories for comparisons, and feeling cognitive conflicts.

A Study of the Factors of Synchronization Model on Myocardial Cell Rhythms (심근세포의 동기리듬에 관한 공학적 연구)

  • 박민용
    • Journal of Biomedical Engineering Research
    • /
    • v.5 no.1
    • /
    • pp.33-38
    • /
    • 1984
  • Biological rhythms are very important phenomena to generate, grow a living thing. However, the origin of rhythms are not disclosed completely until now. Eack myocardial cell has a natural rhythm of itself, and synchronization is happened when two cells are come in contact with each other. In this research, a simple synchronization model has been proposed and studied, refering to the physiological model. The changes of the synchronization rhythms in experimental results are compared with that of the model.

  • PDF

Molt cycle in Neomysis awatschensis(Crustacea : Mysidacea) based on marsupial development

  • Ma, Chae-Woo;Oh, Chul-Woong;Kim, Jong-Chun
    • Proceedings of the Korean Society of Fisheries Technology Conference
    • /
    • 2001.10a
    • /
    • pp.317-318
    • /
    • 2001
  • In crustacea the molting cycle is the most important physiological process affecting growth, behaviour, reproduction and population dynamics through their life span. Particularly molt cycle is closely related to reproductive cycle, and it is important to determine the successive stages of molt cycle to understand reproductive phenomena including ovarian cycle and the development of the embryos in the marsupium. (omitted)

  • PDF

Concentration distributions during flow of confined flowing polymer solutions at finite concentration: slit and grooved channel

  • Hernandez-Ortiz, Juan P.;Ma, Hong-Bo;de Pablo, Juan J.;Graham, Michael D.
    • Korea-Australia Rheology Journal
    • /
    • v.20 no.3
    • /
    • pp.143-152
    • /
    • 2008
  • Simulations of solutions of flexible polymer molecules during flow in simple or complex confined geometries are performed. Concentrations from ultradilute up to near the overlap concentration are considered. As concentration increases, the hydrodynamic migration effects observed in dilute solution unidirectional flows (Couette flow, Poiseuille flow) become less prominent, virtually vanishing as the overlap concentration is approached. In a grooved channel geometry, the groove is almost completely depleted of polymer chains at high Weissenberg number in the dilute limit, but at finite concentration this depletion effect is dramatically reduced. Only upon inclusion of hydrodynamic interactions can these phenomena be properly captured.