• Title/Summary/Keyword: biological function

Search Result 2,143, Processing Time 0.024 seconds

AtHAP3b Plays a Crucial Role in the Regulation of Flowering Time in Arabidopsis during Osmotic Stress

  • Chen, Nai-Zhi;Zhang, Xiu-Qing;Wei, Peng-Cheng;Chen, Qi-Jun;Ren, Fei;Chen, Jia;Wang, Xue-Chen
    • BMB Reports
    • /
    • v.40 no.6
    • /
    • pp.1083-1089
    • /
    • 2007
  • The HAP complex has been found in many eukaryotic organisms. HAP recognizes the CCAAT box present in the promoters of 30% of all eukaryotic genes. The HAP complex consists of three subunits - HAP2, HAP3 and HAP5. In this paper, we report the biological function of the AtHAP3b gene that encodes one of the HAP3 subunits in Arabidopsis. Compared with wild-type plants, hap3b-1 and hap3b-2 mutants exhibited a delayed flowering time under long-day photoperiod conditions. Moreover, the transcription levels of FT were substantially lower in the mutants than in the wild-type plants. These results imply that AtHAP3b may function in the control of flowering time by regulating the expression of FT in Arabidopsis. In a subsequent study, AtHAP3b was found to be induced by osmotic stress. Under osmotic stress conditions, the hap3b- 1 and hap3b-2 mutants flowered considerably later than the wild-type plants. These results suggest that the AtHAP3b gene plays more important roles in the control of flowering under osmotic stress in Arabidopsis.

Application of the H Infinity Control Principle to the Sodium Ion Selective Gating Channel on Biological Excitable Membranes

  • Hirayama, Hirohumi
    • International Journal of Control, Automation, and Systems
    • /
    • v.2 no.1
    • /
    • pp.23-38
    • /
    • 2004
  • We proposed the infinity control principle to evaluate the Biological function. The H infinity control was applied to the Sodium (Na) ion selective gating channel on the excitable cellular membrane of the neural system. The channel opening, closing and inactivation processes were expressed by movements of three gates and one inactivation blocking particle in the channel pore. The rate constants of the channel state transition were set to be voltage dependent. The temporal changes in amounts per unit membrane area of the channel states were expressed by means of eight differential equations. The biochemical mimetic used to complete the Na ion selective channel was regarded as noise. The control inputs for ejecting the blocking particle with plugging in the channel pore were set for the active transition from inactivated states to a closed or open state. By applying the H infinity control, we computed temporal changes in the channel states, observers, control inputs and the worst case noises. The present paper will be available for evaluating the noise filtering function of the biological signal transmission system.

Estimation of Relative Biological Effectiveness for Carbon Beam

  • Onizuka, Y.;Endo, S.;Takada, M.;Ishikawa, M.;Hoshi, M.;Uehara, S.;Hayabuchi, N.;Maeda, N.;Shizuma, K.
    • Proceedings of the Korean Society of Medical Physics Conference
    • /
    • 2002.09a
    • /
    • pp.219-221
    • /
    • 2002
  • In this work, single event spectra were measured in order to gain the microdosimetric parameters of some heavy ion radiotherapy fields at HIMAC. Microdosimetry is now a well-established technique for the investigation of complex mixed radiation field. Changes in frequency mean lineal energy y$\_$F/ as a function of thickness of A150 phantom were obtained. The absorbed dose was obtained by using y$\_$F/. A direct relation between this single event probability distribution and relative biological effectiveness (RBE) was assumed in order to estimate RBE using the response function.

  • PDF

Psychiatric Implication of Synaptic Adhesion Molecules and Scaffold Proteins (시냅스 접착 단백질과 구조 단백질의 정신과적 의의)

  • Oh, Daeyoung
    • Korean Journal of Biological Psychiatry
    • /
    • v.17 no.3
    • /
    • pp.119-126
    • /
    • 2010
  • Synaptic adhesion molecules mediate synapse formation, maturation and maintenance. These proteins are localized at synaptic sites in neuronal axons and dendrites. These proteins function as a bridge of synaptic cleft via interaction with another synaptic adhesion molecules in the opposite side. They can interact with scaffold proteins via intracellular domain and recruit many synaptic proteins, signaling proteins and synaptic vesicles. Scaffold proteins function as a platform in dendritic spines or axonal terminals. Recently, many genetic studies have revealed that synaptic adhesion molecules and scaffold proteins are important in neurodevelopmental disorders, psychotic disorders, mood disorders and anxiety disorders. In this review, fundamental mechanisms of synapse formation and maturation related with synaptic adhesion molecules and scaffold proteins are introduced and their psychiatric implications addressed.

Cell type-specific gene expression profiling in brain tissue: comparison between TRAP, LCM and RNA-seq

  • Kim, TaeHyun;Lim, Chae-Seok;Kaang, Bong-Kiun
    • BMB Reports
    • /
    • v.48 no.7
    • /
    • pp.388-394
    • /
    • 2015
  • The brain is an organ that consists of various cell types. As our knowledge of the structure and function of the brain progresses, cell type-specific research is gaining importance. Together with advances in sequencing technology and bioinformatics, cell type-specific transcriptome studies are providing important insights into brain cell function. In this review, we discuss 3 different cell type-specific transcriptome analyses i.e., Laser Capture Microdissection (LCM), Translating Ribosome Affinity Purification (TRAP)/RiboTag, and single cell RNA-Seq, that are widely used in the field of neuroscience. [BMB Reports 2015; 48(7): 388-394]

Electrochemical Regeneration of FAD by Catalytic Electrode Without Electron Mediator and Biochemical Reducing Power

  • JEON SUNG JIN;SHIN IN HO;SANG BYUNG IN;PARK DOO HYUN
    • Journal of Microbiology and Biotechnology
    • /
    • v.15 no.2
    • /
    • pp.281-286
    • /
    • 2005
  • We created a new graphite-Cu(II) electrode and found that the electrode could catalyze FADH$_2$ oxidation and FAD reduction coupled to electricity production and consumption, respectively. In a fuel cell with graphite-Cu(II) anode and graphite-Fe(III) cathode, the electricity was produced by coupling to the spontaneous oxidation of FADH$_2$ Fumarate and xylose were not produced from the enzymatic oxidation of succinate and xylitol without FAD, respectively, but produced with FAD. The production of fumarate and xylose in the reactor with FAD electrochemically regenerated was maximally 2- 5 times higher than that in the reactor with FAD. By using this new electrode with catalytic function, a bioelectrocatalysts can be engineered; namely, oxidoreductase (e.g., lactate dehydrogenase) and FAD can function for biotransformation without an electron mediator and second oxidoreductase for cofactors recycling.

Implementation of Biological Information System Using Microprocessor(I)-Scanconverter- (마이크로프로세서를 이용한 생체정보시스템의 구성에 관한 연구(I)-환자감시 장치용 Scanconverter를 중심으로)

  • 박상희;김원기
    • Journal of Biomedical Engineering Research
    • /
    • v.7 no.1
    • /
    • pp.3-10
    • /
    • 1986
  • In this paper, a scanconverter which displays the biological signals of low frequency on CRT for the purpose of easy read-out is attempted to design for using the CRTC, and it stows some good effectivenesses The results obtained in this experiment are as follows : (1) Using only one chip, CRT controller, it can display both waveforms and characters simultaneously. (2) The flexibility of CPU program can be obtained using the sub-microproce ssor function of CRTC chip. (3) The trend of digital data is possible through the graphic function (4) The vibration of displayed waveform can be prevented using the chip simplification and the trigger signal of one chip. (5) Operation with microprocessor malies the expansion and interface easy.

  • PDF

Chemical Genetics and Chemical Genomics: High Throughput Profiling of Drugs, Therapeutic Genes and Disease Networks

  • Kim, Tae-Kook
    • Proceedings of the PSK Conference
    • /
    • 2003.10a
    • /
    • pp.97-99
    • /
    • 2003
  • With advances in determining the entire DNA sequence of the human genome, it is now critical to systematically identify the function of a number of genes in the human genome. These biological problems, especially those in human diseases including cancer, should be addressed in human cells in which genetic approaches have been extremely difficult to implement. To overcome this, my efforts have focused on the development of a novel “chemical genetic/genomic approach” that uses small molecules to “probe and identify” the function of genes in specific biological process or pathway in human cells. (omitted)

  • PDF

The Coupling Effects of Excitatory and Inhibitory Connections Between Chaotic Neurons Having Gaussian-shaped Refractory Function With Hysteresis

  • Park, Changkyu;Lee, Ju-Jang
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1998.10a
    • /
    • pp.356-361
    • /
    • 1998
  • Neural Networks, modeled succinctly from the real nervous system of a living body, can be categorized into two folds; artificial neural network(ANN) and biological neural network(BNN). While the former has been developed to solve practical problems using function approximation capability, pattern classification) clustering algorithm, etc, the latter has been focused on verifying the information processing capability to which brain research gives an impetus, by mimicking real biological systems. However, BNN suffers Iron severe nonlinearities dealt with. A bridge between two neural networks is chaotic neural network(CNN), which simply delineate the real nor-vous system and comprises almost all the ANN structures by selecting parameters. Main research theme of this area is to develop an explanation tool to clarify the information processing mechanism in biological systems and its extension to engineering applications. The CNN has a Gaussian-shaped refractory function with hysteresis effect and the chaotic responses of it have been observed fur a wide range of parameter space. Through the examination of the coupling effects of excitatory and inhibitory connections, the secrets of information processing and memory structure will appear.

  • PDF