• Title/Summary/Keyword: maximal function

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Regulation of Chilling Tolerance in Rice Seedlings by Plant Hormones

  • Chu, Chun;Lee, Tse-Min
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.3
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    • pp.288-298
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    • 1992
  • Since the major important factors limiting plant growth and crop productivity are environmental stresses, of which low temperature is the most serious. It has been well known that many physiological processes are alterant in response to the environmental stress. With regard to the relationship between plant hormones and the regulation of chilling tolerance in rice seedlings, the major physiological roles of plant hormones: abscisic acid, ethylene and polyamines are evaluated and discussed in this paper. Rice seedlings were grown in culture solution to examine the effect of such plant hormones on physiological characters related to chilling tolerance and also to compare the different responses among tested cultivars. Intact seedlings about 14 day-old were chilled at conditions of 5$^{\circ}C$ and 80% relative humidity for various period. Cis-(+)-ABA content was measured by the indirect ELISA technique. Polyamine content and ethylene production in leaves were determined by means of HPLC and GC respectively. Chilling damage of seedlings was evaluated by electrolyte leakage, TTC viability assay or servival test. Our experiment results described here demonstrated the physiological functions of ABA, ethylene, and polyamines related to the regulation of chilling tolerance in rice seedlings. Levels of cis-(+)-ABA in leaves or xylem sap of rice seedlings increased rapidly in response to 5$^{\circ}C$ treatment. The tolerant cultivars had significant higher level of endogenous ABA than the sensitive ones. The ($\pm$)-ABA pretreatment for 48 h increased the chilling tolerance of the sensitive indica cultivar. One possible function of abscisic acid is the adjustment of plants to avoid chilling-induced water stress. Accumulation of proline and other compatible solutes is assumed to be another factor in the prevention of chilling injuies by abscisic acid. In addition, the expression of ABA-responsive gene is reported in some plants and may be involving in the acclimation to low temperature. Ethylene and its immediate precusor, 1-amincyclopropane-1-carboxylic acid(ACC) increased significantly after 5$^{\circ}C$ treatment. The activity of ACC synthase which converts S-adenosylmethionine (SAM) to ACC enhanced earlier than the increase of ethylene and ACC. Low temperature increased ACC synthase activity, whereas prolonged chilling treatment damaged the conversion of ACC to ethylene. It was shown that application of Ethphon was beneficial to recovering from chilling injury in rice seedlings. However, the physiological functions of chilling-induced ethylene are still unclear. Polyamines are thought to be a potential plant hormone and may be involving in the regulation of chilling response. Results indicated that chilling treatment induced a remarkable increase of polyamines, especially putrescine content in rice seedlings. The relative higher putrescine content was found in chilling-tolerant cultivar and the maximal level of enhanced putrescine in shoot of chilling cultivar(TNG. 67) was about 8 folds of controls at two days after chilling. The accumulation of polyamines may protect membrane structure or buffer ionic imbalance from chilling damage. Stress physiology is a rapidly expanding field. Plant growth regulators that improve tolerance to low temperature may affect stress protein production. The molecular or gene approaches will help us to elucidate the functions of plant hormones related to the regulation of chilling tolerance in plants in the near future.

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A Review : On Exercise Performance Induction Gene Factors Change (운동이 유전자 조절물질에 미치는 영향에 관한 고찰)

  • Um, Ki-Mai;Yang, Yoon-Kwon;Kim, Tae-Woo
    • Journal of Korean Physical Therapy Science
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    • v.8 no.1
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    • pp.745-758
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    • 2001
  • The purpose of study to phenomenological examine and the mechanism regarding the gene(DNA, RNA, Protein) and sports to studied, analyzed. and evaluated. This review considers the evidence for genetic effects in several determinants of endurance performance and resistance performance, namely: body measurements and physique, body fat pulmonary functions, cardiac and circulatory functions, muscle characteristics. substrate utilization, maximal aerobic power and other. Moreover, the response to aerobic training of indicators aerobic work metabolism and endurance performance is reviewed, with emphasis on the specificity of the response and the individual differences observed in training ability. This study indicate that improvement of 'Enhancer Action' in RNA genes changed by exercise or sports. Moreover exercise was effect on Central Dogma with DNA makes RNA makes Protein. and think that occurred with exercise influence on skeletal muscle into cell have to Myosin Heavy Chain (MHC) changed was after exercise performance, which accompanied into skeletal muscle that were exercise-induces gene-modulation that is, take gene mutations. This study known that existed hormone(epinephrine)-immune system with interaction. Exercise were altered insulin binding and MAP Kinase signaling increased into immune cells. This review suggested that the high rate of glutamine utilization by cells of the immune system serves to maintain a high intra cellular concentration of the intermediates of biosynthetic pathways such that optimal rates of DNA, RNA and protein synthesis can be maintained. In the absence of glutamine, lymphocytes do not proliferate in vitro: proliferation increase greatly as the glutamine concentration increase. Glutamine is synthesized in skeletal muscle. Skeletal muscle and plasma glutamine levels are lowered by sepsis, injury, bums, surgery and endurance exercise and in the overtrained athlete. The study of result show that production of ET-1 is markedly increased tissue specifically in the heart by exercise without appreciable changes in endothelin-converting enzyme and endothelial receptor expressions, suggest that myocardial ET-1 may participate in modulation of cardiac function during exercise. Conclusionally, this study indicate that improvement of 'Enhancer Action' in RNA genes changed by exercise or sports. Moreover exercise was effect on Central Dogma with DNA makes RNA makes Protein. This study is expected to contribute the area of sports science, medicine, hereafter more effort is required to establish the relation between gene alters and exercise amount.

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The Study on $Na^+-Ca^{++}$ Exchange in Heart Mitochondria (심근 Mitochondria의 $Na^+-Ca^{++}$교환에 관한 연구)

  • Shin, Sang-Goo;Kim, Myung-Suk;Lim, Jung-Kyoo
    • The Korean Journal of Pharmacology
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    • v.18 no.2
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    • pp.89-102
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    • 1982
  • The $Na^+-and\;K^+-induced\;Ca^{++}$ release was measured isotopically by millipore filter technique in pig heart mitochondria. With EGTA-quenching technique, the characteristics of mitochondrial $Ca^{++}-pool$ and the sources of $Ca^{++}$ released from mitochondria by $Na^+\;or\;K^+$ were analyzed. The mitochondrial $Ca^{++}-pool$ could be distinctly divided into two components: internal and external ones which were represented either by uptake through inner membrane, or by energy independent passive binding to external surface of mitochondria, respectively. In energized mitochondria, a large portion of $Ca^{++}$was transported into internal pool with little external binding, while in de-enerigzed state, a large portion of transported $Ca^{++}$ existed in the external pool with limited amount of $Ca^{++}$ in the internal pool which was possibly transported through the $Ca^{++}-carrier$ present in the inner membrane. $Na^+$ induced the $Ca^{++}$ release from both internal pool and external pool and external binding pool of mitochondria. In contrast, $K^+$ did not affect $Ca^{++}$ of the internal pool, but, displaced $Ca^{++}$ bound to external surface of the mitochondria. When the $Ca^{++}-reuptake$ was blocked by EGTA, the $Ca^{++}$ release from the internal pool by $Na^+$ was rapid; the rate of $Ca^{++}-efflux$ appeared to be a function of $[Na^+]^2$ and about 8mM $Na^+$ was required to elicit half-maximal velocity of $Ca^{++}-efflux$. So it was revealed that $Ca^{++}-efflux$ velocity was particulary sensitive to small changes of the $Na^+$ concentration in physiological range. Energy independent $Ca^{++}-binding$ sites of mitochondrial external surface showed unique characteristics. The total number of external $Ca^{++}-binding$ sites of pig heart mitochondria was 29 nmoles per mg protein and the dissociation constant(Kd) was $34{\mu}M$. The $Ca^{++}-binding$ to the external sites seemed to be competitively inhibited by $Na^+\;and\;K^+$; the inhibition constant(Ki) were 9.7 mM and 7.1 mM respectively. Considering the intracellular ion concentrations and large proportion of $Ca^{++}$ uptake in energized mitochondria, the external $Ca^{++}-binding$ pool of the mitochondria did not seem to play a significant role on the regulation of intracellular free $Ca^{++}$ concentration. From this experiment, it was suggested that a small change of intracellular free $Na^+$ concentration might play a role on regulation of free $Ca^{++}$ concentration in cardiac cell by influencing $Ca^{++}-efflux$ from the internal pool of mitochondria.

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Prediction of Implicit Protein - Protein Interaction Using Optimal Associative Feature Rule (최적 연관 속성 규칙을 이용한 비명시적 단백질 상호작용의 예측)

  • Eom, Jae-Hong;Zhang, Byoung-Tak
    • Journal of KIISE:Software and Applications
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    • v.33 no.4
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    • pp.365-377
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    • 2006
  • Proteins are known to perform a biological function by interacting with other proteins or compounds. Since protein interaction is intrinsic to most cellular processes, prediction of protein interaction is an important issue in post-genomic biology where abundant interaction data have been produced by many research groups. In this paper, we present an associative feature mining method to predict implicit protein-protein interactions of Saccharomyces cerevisiae from public protein interaction data. We discretized continuous-valued features by maximal interdependence-based discretization approach. We also employed feature dimension reduction filter (FDRF) method which is based on the information theory to select optimal informative features, to boost prediction accuracy and overall mining speed, and to overcome the dimensionality problem of conventional data mining approaches. We used association rule discovery algorithm for associative feature and rule mining to predict protein interaction. Using the discovered associative feature we predicted implicit protein interactions which have not been observed in training data. According to the experimental results, the proposed method accomplished about 96.5% prediction accuracy with reduced computation time which is about 29.4% faster than conventional method with no feature filter in association rule mining.

Liver Plasma Membrane and Nuclear $T_{3}$ Receptor Binding in the Obese (ob/ob) Mouse (비만 쥐(ob/ob mouse)의 간 세포막과 핵에 있는 $T_{3}$ 수용체의 결합능력에 관한 연구)

  • Kim, Kyung-Ah;Lachance, Paul A.
    • Journal of Nutrition and Health
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    • v.24 no.4
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    • pp.356-365
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    • 1991
  • $L-Triiodothyronine(T_3)$ binding to purified plasma membrane and to isolated nuclei from the same liver in obese(ob/ob) mice and their lean littermates was examined. The maximal binding capacity(Bmax) for $T_3$ receptor of liver nuclei, as compared to lean control, was significantly lower in the obese mouse$(obese 527{\pm}80fmol/mg\;DNA ; lean 883{\pm}62fmol/mg\;DNA)$, without an apparent difference in dissociation constant(Kd). The finding that obese mice have fewer liver nuclear $T_3$ receptors confirms previous reports. The Bmax and Kd of liver plasma membrane $T_3$ receptor were not significantly different between obese and lean mouse, which suggests no defect to be occurring in the function of the plasma membrane $T_3$ receptor and reinforces the view that the peripherally impaired thyroid hormone action in obese mice is a post plasma membrane receptor event. These results further support the hypothesis that the major defect of the thyroid hormone metabolism in genetic obesity occurs at the level of the nuclear receptor.

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Functional Defect and Its Possible Mechanism of Diabetic Cardiomyopathy (당뇨성 심근질환에서의 근장그물 기능이상과 그 작용기전)

  • Kim, Hae-Won;Lee, Hee-Ran;Jang-Yang, Yeon-Jin;Park, Hyoung-Sup;Park, So-Young
    • The Korean Journal of Pharmacology
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    • v.29 no.2
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    • pp.195-202
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    • 1993
  • Oxidative modification of cellular proteins and lipids may play a role in the development of diabetic complications. Diabetic cardiomyopathy has been suggested to be caused by the intracellular $Ca^{2+}$ overload in the myocardium, which is partly due to the defect of calcium transport of the cardiac sarcoplasmic reticulum (SR). In the present study, the possible mechanism of the functional defect of cardiac SR in diabetic rats was studied. Both of the maximal $Ca^{2+}$ uptake and the affinity for $Ca^{2+}$ were decreased in the diabetic rat SR in comparison with the control. To investigate whether the functional defect of the cardiac SR in streptozotocin-induced diabetic rat is associated with the oxidative changes of cardiac SR proteins, the carbonyl group content and glycohemoglobin levels were determined. The increase in carbonyl group content of cardiac SR (2.30 nmols/mg protein, DM; 1.78, control) and in glycohemoglobin level $(13{\sim}17%,\;DM;\;3{\sim}5%,\;control)$ were observed in the diabetics. The extent of increase in calcium transport by phospholamban phosphorylation was greater in the diabetic cardiac SR membranes than that in the control. The phosphorylation levels of phospholamban, as determined by SDS-PAGE and autoradiography with $[{\gamma}^{32}P]ATP$, were increased in diabetic cardiac SR. These results suggest that the impaired cardiac SR function in diabetic rat could be a consequence of the less-phosphorylation of phospholamban in the basal state, which is partly due to the depleted norepinephrine stores in the heart. Furthermore, the oxidative damages in cardiac SR membranes might be one of the additional factors leading to the diabetic cardiomyopathy.

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Bayesian Cognizance of RFID Tags (Bayes 풍의 RFID Tag 인식)

  • Park, Jin-Kyung;Ha, Jun;Choi, Cheon-Won
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.5
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    • pp.70-77
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    • 2009
  • In an RFID network consisting of a single reader and many tags, a framed and slotted ALOHA, which provides a number of slots for the tags to respond, was introduced for arbitrating a collision among tags' responses. In a framed and slotted ALOHA, the number of slots in each frame should be optimized to attain the maximal efficiency in tag cognizance. While such an optimization necessitates the knowledge about the number of tags, the reader hardly knows it. In this paper, we propose a tag cognizance scheme based on framed and slotted ALOHA, which is characterized by directly taking a Bayes action on the number of slots without estimating the number of tags separately. Specifically, a Bayes action is yielded by solving a decision problem which incorporates the prior distribution the number of tags, the observation on the number of slots in which no tag responds and the loss function reflecting the cognizance rate. Also, a Bayes action in each frame is supported by an evolution of prior distribution for the number of tags. From the simulation results, we observe that the pair of evolving prior distribution and Bayes action forms a robust scheme which attains a certain level of cognizance rate in spite of a high discrepancy between the Due and initially believed numbers of tags. Also, the proposed scheme is confirmed to be able to achieve higher cognizance completion probability than a scheme using classical estimate of the number of tags separately.

Tissue Distribution and Toxicokinetics of 4-Tert-Octylphenol in Rats (4-Tert-Octylphenol의 랫드에서의 조직분포 및 독성동태에 관한 연구)

  • Kang Mi Kyung;Ahn Mee Ryung;Chung Hye Joo;Choi Sun Ok;Choi Hong Serk;Yang Ji Sun;Lee Yong Bok;Yoo Tae Moo;Sohn Soo Jung
    • Toxicological Research
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    • v.20 no.3
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    • pp.195-203
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    • 2004
  • 4-Tert-Octylphenol (OP) is a surfactant additive widely used in the manufacture of a variety of detergents and plastic products. OP can disrupt endocrine function in humans and animals. This study was carried out to obtain toxicokinetic parameters of OP in male Sprague-Dawley (SD) rats. Male rats were administered with OP by single oral application of 200 mg/kg body weight. Blood, urine and tissues samples were taken at several time intervals after administration. Analysis of samples for OP was performed by column-switching high performance liquid chromatography (HPLC). In addition, we exam-ined tissue distribution and accumulation of OP after single oral application of 50, 100, and 200 mg/kg, single intravenous injection of 1, 5 and 10 mg/kg or daily application of 50 mg/kg for 14 consecutive days. After single oral administration of 200 mg/kg, Cmax of 213 $\pm$ 123 ng/ml was reached within the first 1.3 hr (Tmax) in the plasma. AUC was calculated for 1,333$\pm$484 ngㆍhr/ml. The final elimination half-life of plasma was longer than that of urine, but urinary clearance was lower than oral. A very small fraction of OP (Fe < 0.0017%) was excreted in urine within 24 hr. These results indicated that the major excretion route of OP was not urine. The mean maximal tissue distribution of OP was obserbed at 6 hr after treatment and slowly decreased time-dependently. High OP concentrations were detected in fat at 24 hr. The OP in fat was slowly released with longer elimination half-life and lower clearance than that of other tissues. OP was not accumulated in the liver following single oral application but 14-day oral treatments resulted in two-fold accumulation. It was probably due to the saturation of detoxification pathways. On the other hand, the mRNA expression of cytochrome P450 isoforms except CYP2C11 was not affected by OP at any dose. The expression of CYP2C11 mRNA decreased in a dose-dependent manner. This result suggests that OP changes expression of the male-specific cytochrome P450 isoforms in rat liver, and these changes are closely related to the toxic and estrogenic effect of OP.

Experimental Study of Endostar Injection Concomitant with Cryoablation on Lung Adenocarcinoma A549 Xenografts

  • Ma, Chun-Hua;Jiang, Rong;Li, Jin-Duo;Wang, Bin;Sun, Li-Wei;Lv, Yuan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6697-6701
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    • 2013
  • Objective: To explore the inhibiting effect and mechanism of Endostar injection concomitant with cryoablation on lung adenocarcinoma A549 xenografts in nude mice. Materials and Methods: A total of 24 nude mice with subcutaneous xenografts of the A549 cell line were established and divided into 4 groups when the maximal diameters of tumors became 1 cm: control group, Endostar group, cryoablation group and combination group (Endostar concomitant with cryoablation). The nude mice were sacrificed after 21-days treatment, tumour tissues were removed to measure their volume, in situ test of TdT-mediated dUTP nick end labeling (TUNEL) was adopted to determine the cellular apoptosis around freezing injury zones, and immunohistochemical SP test was applied for the detection of micro-vessel density (MVD) and vascular endothelial growth factor (VEGF) expression levels. Results: At 21-days after treatment, the growth velocities of control group, Endostar group, cryoablation group and combination group were $236.7{\pm}51.2%$, $220.0{\pm}30.6%$, $159.5{\pm}29.3%$ and $103.3{\pm}25.5%$ (P<0.01), while cellular apoptosis rates of tumors were $21.7{\pm}2.34%$, ($22.17{\pm}1.47$)%, $38.3{\pm}1.37%$ and $49.2{\pm}1.72%$, (P<0.01), respectively, according to the immunohistochemical test. MVD and VEGF expression levels in the combination group were both lower than in other groups (P<0.01), also being positively related (r=0.925, P<0.01). Conclusions: Endostar can significantly improve the inhibitory effects of cryoablation on xenografts of lung adenocarcinoma A549, and the mechanism is probably associated with its function as an inhibitor of tumour neo-angiogenesis through down-regulating VEGF expression.

Carcass characteristics of lambs fed spineless cactus as a replacement for sugarcane

  • de Oliveira, Juliana Paula Felipe;Ferreira, Marcelo de Andrade;Alves, Adryanne Marjorie Souza Vitor;de Melo, Ana Caroline Cerqueira;de Andrade, Ida Barbosa;Urbano, Stela Antas;Suassuna, Juraci Marcos Alves;de Barros, Leonardo Jose Assis;Melo, Tobias Tobit de Barros
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.4
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    • pp.529-536
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    • 2018
  • Objective: Fresh sugarcane has been a new roughage source for ruminant's in semiarid regions, a function of the decline of sugar and alcohol industry in recent years. However, there is little data published regarding lambs fed sugarcane associated with spineless cactus. This study evaluated the effect of sugarcane replacement with spineless cactus (0%, 33%, 66%, and 100%) in the diet of Santa $In\hat{e}s$ lambs on carcass characteristics. Methods: Thirty-six non-castrated Santa Ines lambs at four months of age and an initial body weight of $22{\pm}2.3kg$ were assigned in a randomized block design and slaughtered after 70 days of confinement. The effects of spineless cactus as a replacement for sugarcane in the diet of the lambs on the carcass characteristics, commercial cut weight and yield, leg tissue composition, and carcass measurements were studied. Results: The study revealed quadratic behavior in slaughter body weight, and hot and cold carcass weight, with maximum values of 38.60, 18.60, and 18.11 kg and replacement levels of 40.18%, 44.42%, and 43.14%, respectively. The cold carcass yield presented an increasing linear behavior. The compactness index of carcass and leg presented a quadratic effect, with estimated maximal values of 0.28 and 0.57 kg/cm and replacement levels of 43.37% and 45.5%, respectively. The weights of commercial cuts of leg, loin, shoulder, and breast showed quadratic behavior, with maximum values of 2.79, 0.852, 1.46, and 1.30 kg and replacement levels of 49.5, 45.32, 39.0, and 40.7, respectively. For tissue composition, quadratic behavior was verified for leg weight, subcutaneous fat, and total fat. Conclusion: The replacement of sugarcane by spineless cactus at level 44% is recommended for finishing lambs considering that this level improved most of the carcass characteristics, weights, and yields of commercial cuts and leg tissue composition.