Disturbance localization and pole shifting by dynamic compensation

This paper concerns the problem of disturbance localization and pole shifting by dynamic compensation in multivariable linear systems with inaccessible state vector. A necessary and sufficient condition for the solvability of the problem is given. Two synthesis procedures of the compensator are presented: one is based on an observer and the other is based on a dual observer. The observer designed by the proposed procedure acts as as unknown input observer for a linear function. An improved procedure of designing a reduced order unknown input observer is also given. The result may be applicable to reducing the compensator order.     

Optimal sulfur dioxide gas discharge control for Osaka city,Japan

This paper, using actual data, establishes a dynamical model of sulfur dioxide pollution and gives an optimal discharge control policy for Osaka city in Japan.From a mass balance of the gas, a linear scalar state equation is obtained. In spite of the simplicity of the model, it can represent the effect of wind speed, inversion layer, diffusion, boundary concentration and discharge intensity of the pollutant sources. Six unknown parameters in the model and system noise variance are identified by maximizing likelihood function by Flexible Polyhedron Search. This makes the model reasonably representative.A quadratic loss function for the control problem is the weighted sum of two terms; the loss caused by the discharge control and the loss due to the air pollution. The wind speed varies at random according to a Markov transition matrix, considering actual emergency control situations. The optimal control policy is obtained by Dynamic Programming, resulting in linear feedback control dependent on the wind speed, involving a Riccati equation. A practical method of the determination of the weighting coefficient in the loss function is proposed.Since the model is a scalar state system, the whole calculation can be performed with a relatively small computer. This ease of computation and the Markov property of the wind speed suggest that the proposed method is applicable to the actual emergency discharge control.     

A projection for global CO2 emissions from the industrial sector through 2030 based on activity level and technology changes

In this study, we simulate global CO₂ emissions and their reduction potentials in the industrial sector up to the year 2030. Future industrial CO₂ emissions depend on changes in both technology and industrial activity. However, earlier bottom-up analyses mainly focused on technology change. In this study, we estimate changes in both technology and industrial activity. We developed a three-part simulation system. The first part is a macro economic model that simulates macro economic indicators, such as GDP and value added by sector. The second part consists of industrial production models that simulate future steel and cement production. The third part is a bottom-up type technology model that estimates future CO₂ emissions. Assuming no changes in technology since 2005, we estimate that global CO₂ emissions in 2030 increase by 15 GtCO₂ from 2005 level. This increase is due to growth in industrial production. Introducing technological reduction options within 100 US$/tCO₂ provides a reduction potential of 5.3 GtCO₂ compared to the case of no technology changes. As a result, even with large technological reduction potential, global industrial CO₂ emissions in 2030 are estimated to be higher as compared to 2005 level because of growth of industrial production.     

Cardioprotective effect of angiotensin-converting enzyme inhibition against hypoxia/reoxygenation injury in cultured rat cardiac myocytes

BACKGROUND: Although ACE inhibitors can protect myocardium against ischemia/reperfusion injury, the mechanisms of this effect have not yet been characterized at the cellular level. The present study was designed to examine whether an ACE inhibitor, cilazaprilat, directly protects cardiac myocytes against hypoxia/reoxygenation (H/R) injury. METHODS AND RESULTS: Neonatal rat cardiac myocytes in primary culture were exposed to hypoxia for 5.5 hours and subsequently reoxygenated for 1 hour. Myocyte injury was determined by the release of creatine kinase (CK). Both cilazaprilat and bradykinin significantly inhibited CK release after H/R in a dose-dependent fashion and preserved myocyte ATP content during H/R, whereas CV-11974, an angiotensin II receptor antagonist, and angiotensin II did not. The protective effect of cilazaprilat was significantly inhibited by Hoe 140 (a bradykinin B2 receptor antagonist), NG-monomethyl-L-arginine monoacetate (L-NMMA) (an NO synthase inhibitor), and methylene blue (a soluble guanylate cyclase inhibitor) but not by staurosporine (a protein kinase C inhibitor), aminoguanidine (an inhibitor of inducible NO synthase), or indomethacin (a cyclooxygenase inhibitor). Cilazaprilat significantly enhanced bradykinin production in the culture media of myocytes after 5.5 hours of hypoxia but not in that of nonmyocytes. In addition, cilazaprilat markedly enhanced the cGMP content in myocytes during hypoxia, and this augmentation in cGMP could be blunted by L-NMMA and methylene blue but not by aminoguanidine. CONCLUSIONS: The present study demonstrates that cilazaprilat can directly protect myocytes against H/R injury, primarily as a result of an accumulation of bradykinin and the attendant production of NO induced by constitutive NO synthase in hypoxic myocytes in an autocrine/paracrine fashion. NO modulates guanylate cyclase and cGMP synthesis in myocytes, which may contribute to the preservation of energy metabolism and cardioprotection against H/R injury.     

Neck electrical impedance for measurement of swallowing

Recently, videofluorography has been used for evaluation of swallowing function in the rehabilitation field. But it is not easy to evaluate swallowing disorders simply. In addition, there are problems of exposure for daily use. We have proposed a measurement method of swallowing using bioelectrical impedance (impedance pharyngography, IPG) which has advantages of easy handling and noninvasive measurement. Appropriate electrode position have been determined. The waveforms of IPG can be obtained with some extent reproducibility. The change of neck electrical impedance in the pharyngeal phase is mainly caused by the changes of equivalent cross sectional area near the epiglottis. The possibilities of applications for clinical diagnosis have been shown. © 2000 Scripta Technica, Electr Eng Jpn, 130(4): 35–44, 2000     

Evaluation of biological responses to polymeric biomaterials by RT-PCR analysis III: study of HSP 70, 90 and 47 mRNA expression

In this study, in order to analyze how cells recognize biomaterials, mRNA was evaluated on various substrates as shown in the attached HeLa S3 cells. The expressed Heat-Shock Protein (HSP) 70A, 70B, 90 and 47 mRNA were isolated and detected using the RT-PCR method. As a result, 70B, 90 and 47 mRNA expressions varied with differences in the hydrophilicity hydrophobicity of the substrates. HSP mRNAs outcome was induced significantly in the HeLa S3 cells that had adhered onto the hydrophilic surfaces. On the other hand, in the cells that had adhered to the hydrophobic surfaces, HSP mRNAs expressions were low. In the non-adhered HeLa S3 cells the tendency found in HSP 70B and HSP 47 mRNA's expressions was the same as that found in adhered cells, while there were no significant differences in the HSP 90 mRNA expression among either of the samples. We have concluded that HSP mRNAs expression is an important marker in the study of cell-polymer interactions.     

Effect of alterations of basic amino acid residues of Escherichia coli heat-stable enterotoxin II on enterotoxicity

Escherichia coli heat-stable enterotoxin II (STII) is composed of 48 amino acid residues. Among these, one histidine, two arginine, and six lysine residues are basic. Isoelectric focusing showed that the isoelectric point of STII is 9.7, indicating that the side chains of some of these basic amino acid residues project outside the molecule. To understand the role that these basic amino acid residues play in toxicity, STII was chemically modified with ethoxyformic anhydride, maleic anhydride, and phenylglyoxal, which alter the side chains of basic amino acid residues in proteins. Maleic anhydride, which modifies the epsilon amino group, caused a significant loss of enterotoxic activity, but the other two modifiers did not. This indicated that lysine residues play an important role in the expression of the enterotoxic activity of STII and that the contribution of the other basic amino acid residues to the toxicity is relatively low. To confirm this hypothesis, we substituted these nine basic amino acid residues by oligonucleotide-directed site-specific mutagenesis and examined the enterotoxicity of these purified mutant STIIs. The enterotoxic activity was reduced when the lysine residues at positions 18, 22, 23, and 46 were substituted. In particular, the substitution at positions 22 and 23 induced a remarkable reduction. These results demonstrate that the lysine residues at positions 22 and 23 are very important in the expression of the enterotoxic activity of STII.     

Preparation of a novel functional hydrogel consisting of sulfated glucoside-bearing polymer: activation of basic fibroblast growth factor

Integrins play a critical role in cell adhesion and mediate cell signaling. This report identifies the association of serine protein kinase activity with the beta 1 integrin by immunoprecipitation and phosphoamino acid analysis techniques. Reprecipitation techniques suggested that the serine kinase activity was not a member of the protein kinase C family. By gel filtration, most of the protein kinase activity associated with beta 1 integrin as well as most of the cell-surface beta 1 integrin was present in large detergent resistant complexes. These results suggest that serine protein kinase activity associated with the beta 1 integrin may play a role in signaling via the beta 1 integrin.