• 제목/요약/키워드: Physiological phenomena

검색결과 132건 처리시간 0.032초

핵의학 영상과 추적자 동력학 분석법을 이용한 생체기능 정량화 (Quantitation of In-Vivo Physiological Function using Nuclear Medicine Imaging and Tracer Kinetic Analysis Methods)

  • 김수진;김경민;이재성
    • Nuclear Medicine and Molecular Imaging
    • /
    • 제42권2호
    • /
    • pp.145-152
    • /
    • 2008
  • Nuclear medicine imaging has an unique advantage of absolute quantitation of radioactivity concentration in body. Tracer kinetic analysis has been known as an useful investigation methods in quantitative study of in-vivo physiological function. The use of nuclear medicine imaging and kinetic analysis together can provide more useful and powerful intuition in understanding biochemical and molecular phenomena in body. There have been many development and improvement in kinetic analysis methodologies, but the conventional basic concept of kinetic analysis is still essential and required for further advanced study using new radiopharmaceuticals and hybrid molecular imaging techniques. In this paper, the basic theory of kinetic analysis and imaging techniques for suppressing noise were summarized.

우리나라 잡초방제의 연구현황 (Status of Weed Control Research in Korea)

  • 이종훈;강병화
    • 한국작물학회지
    • /
    • 제23권3호
    • /
    • pp.5-11
    • /
    • 1978
  • Since 1970, herbicides have been widely used in the crop production, especially in paddy field in Korea. In 1978, both preemergence and postemergence type herbicides are applied in the approximately 70% of total paddy field and 15% of upland to control weeds. Most herbicides control annual weeds effectively, but perennials have been problems in the paddy field. Under upland conditions, effectiveness of herbicides varies depending on many environmental conditions (soil moisture, soil physical properties, temperature, etc.) as well as uniform application of appropriate amounts of herbicides. In Korea, many research works have been concentrated on the screening of new herbicides in terms of herbicide effectiveness and yield or phytotoxicity of crops, and especially on the paddy field. However, physiological aspects of herbicidal action in plant and interaction of herbicides with the environments have not been studied approximately. Therefore, researches on the uptake of herbicides and the influence of herbicides on the physiological phenomena such as photosynthesis, respiration, nutrient uptake etc., to control troublesome perennial weeds in the paddy field are needed in future. Also some researches are needed to improve effectiveness of herbicirdes under upland conditions.

  • PDF

The Centrifugal Influence on Gustatory Neurons in the Nucleus of the Solitary Tract

  • Cho, Young Kyung
    • International Journal of Oral Biology
    • /
    • 제40권4호
    • /
    • pp.161-166
    • /
    • 2015
  • Neuronal activities of taste-responsive cells in the nucleus of the solitary tract (NST) are affected by various physiological factors, such as blood glucose level or sodium imbalance. These phenomena suggest that NST taste neurons are under the influence of neural substrates that regulate nutritional homeostasis. In this study, we reviewed a series of in vivo electrophysiological investigations that demonstrate that forebrain nuclei, such as the lateral hypothalamus or central nucleus of the amygdala, send descending projections and modulate neuronal activity of gustatory neurons in the NST. These centrifugal modulations may mediate plasticity of taste response in the NST under different physiological conditions.

Saccharomyces cerevisiae의 물질대사에 미치는 중성자의 영향

  • 이민재
    • Journal of Plant Biology
    • /
    • 제7권4호
    • /
    • pp.9-14
    • /
    • 1964
  • According to the results measured the respiratory quotient of Saccharomyces cerevisiae with neutron radiation by manometric direct method, the respiratory quotient of them was stimulated at the dose(7$\times$106N/$\textrm{cm}^2$/sec) of neutron radiation for 60 seconds, and was inhibited in each group irradiated at the high dose (7$\times$108N/$\textrm{cm}^2$/sec) of neutron. Its physiological effects influenced on neutron had relations with respiratory quotient, reproductive rate and fermentation in the curve of normal logarithmic phase. The multiple reactions which appeared in yeast, indicated that a great deal of physiological function were closely correlated with the irradiated dosage of neutron. The kinds of free amino acid in yeast irradiated with neutron were different from those of unirradiated yeast. The activityof dehydrogenase system accelerated the metabolic function of yeast irradiated at some low dose of neutron. By this results, it may demonstrate that the fact which the phenomena obtained in the stimulation of neutron possess its character for several generation, is dependent on the theory of mutation. Subsequently, it seemed reasonable certain dominant type of microorganisms.

  • PDF

Rabbit의 당수치에 따른 모세혈관 혈류의 카오스적 분석에 대한 연구 (A Study of the Chaotic Analysis of Flow of Capillary Blood Vessel by glucose index)

  • 최준영;조승열;김덕훈;임종덕;임재중;남상희
    • 대한의용생체공학회:학술대회논문집
    • /
    • 대한의용생체공학회 1996년도 추계학술대회
    • /
    • pp.258-262
    • /
    • 1996
  • The physiological systems have nonlinear complex phenomena. Expecially, the flow of capillary blood vessel has a nonlinear dynamic system. Thus, this study analyzes nonlinear characteristics of the flow of capillary blood vessel in physiological systems using chaotic tools(phase space reconstruction, correlation dimension, largest lyapunov exponent). Experimental data have been acquired from examining 10 rabbits. The results of chaotic analysis showed a decreasing largest lyapunov exponent and correlation dimension according to increasement glocose index. And we also know the chaotic behavior.

  • PDF

An interpretation of intelligence based on mathematical integration of elementary mechanisms in biology

  • Chauvet, Gilbert A.
    • 한국지능시스템학회:학술대회논문집
    • /
    • 한국퍼지및지능시스템학회 2003년도 ISIS 2003
    • /
    • pp.353-357
    • /
    • 2003
  • Although it is more and more well accepted that modeling is a help for experimental biology, little is known about how to integrate physiological processes in general. The fact that no general theory exist in biology has big consequences, the most important being the difficulty to integrate biological phenomena. 1 will present a solution for the three dependent following issues: i) in an appropriate theoretical framework, integration consists in coupling models that each describe physiological mechanisms (formalization is a necessary condition to integration); ii) a biological theory with its own concepts leads to unifying principles in biology that are different from and complementary to physical principles; iii) such a formalized theory consists in a representation in terms of functional interactions and a specific formalism(S-Propagator). Hence a biological theory is of a topological and geometrical nature, in contrast to physical theories that are of a geometrical nature. An application to the interpretation of intelligence is proposed, based on the "intelligence"of movement.

  • PDF

이산 도트 자극에서 시각적 착시를 인식하는 시각 모델 (A Visual Model for the Perception of the Optical illusions from Discrete Dot Stimuli)

  • 정은화;홍경호
    • 정보처리학회논문지B
    • /
    • 제10B권6호
    • /
    • pp.639-646
    • /
    • 2003
  • 본 논문은 일련의 불연속적인 도트 자극으로부터 시각적 착시현상을 추출하는 신경회로망 모델을 제시한다. 제안된 모델은 시각 정보처리 경로에서 발견되는 시각 세포들의 특성을 근거로 한다. 본 연구는 일련의 이산 도트 자극들이 개별적인 도트들로 인식하지 않고 연속적인 가상의 윤곽으로 인식하는 시각적 착시 현상을 나타내는 생리심리학 실험을 기초로 하여 도트 자극의 시각적 착시를 구현한 것으로서 실험에서는 가상 다각형 형태로 배치된 6에서 10개의 도트자극들을 사용한다. 이 실험 데이터는 Smith & Vos가 생리심리학적 실험에서 다룬 데이터와 유사하다. 제안된 모델은 이산 도트자극으로부터 연속적인 착시 윤곽을 성공적으로 추출한다.

1/f 변동리듬 특성을 가지는 음이 쾌적감성에 미치는 영향 (Effect of 1/f Fluctuation Sound on Comfort Sensibility)

  • 전용웅;조암
    • 대한인간공학회지
    • /
    • 제25권4호
    • /
    • pp.9-22
    • /
    • 2006
  • 1/f fluctuation characteristics can be seen in various natural phenomena, such as breezes, streams, candle flames and the luminous patterns of fireflies. It is said that the 1/f fluctuation are comfortable for human beings. And they are introduced into many industrial products, such as an air conditioner, music, lighting, etc. This study focused on verifying the effects of 1/f fluctuation sound on comfort sensibility. Stimulus were divided into three groups(Group 1, 2, 3) by sound generation methodology. Fluctuation patterns of group 1, 2 were given by three types of fluctuation, 1/f0, 1/f1, 1/f2, and its of group 3 were given by two types of pure tone, 1/f1. In order to verify the effects, we measured the physiological responses of the subjects such as EEG(Electroencephalogram), ERP(Event-Related Potential), and these physiological responses were compared with subjective assessments, free answers. Consequently, we found that factor which had an effect on comfort sensibility was cognitive factor(for stimulus) rather than 1/f fluctuation sound pattern.

지능형 감정인식 모델설계 (Design of Intelligent Emotion Recognition Model)

  • 김이곤;김서영;하종필
    • 한국지능시스템학회:학술대회논문집
    • /
    • 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
    • /
    • pp.46-50
    • /
    • 2001
  • Voice is one of the most efficient communication media and it includes several kinds of factors about speaker, context emotion and so on. Human emotion is expressed in the speech, the gesture, the physiological phenomena (the breath, the beating of the pulse, etc). In this paper, the method to have cognizance of emotion from anyone's voice signals is presented and simulated by using neuro-fuzzy model.

  • PDF

Design of Intelligent Emotion Recognition Model

  • Kim, Yi-gon
    • 한국지능시스템학회논문지
    • /
    • 제11권7호
    • /
    • pp.611-614
    • /
    • 2001
  • Voice is one of the most efficient communication media and it includes several kinds of factors about speaker, context emotion and so on. Human emotion is expressed is expressed in the speech, the gesture, the physiological phenomena(the breath, the beating of the pulse, etc). In this paper, the emotion recognition method model using neuro-fuzzy in order to have cognizance of emotion from voice signal is presented and simulated.

  • PDF