Switching of H∞ controller under constraints and decision of controller state at instance of the controller switching

In real control systems, certain constraints are placed on the input, state, and output values. If such constraints are violated, the system may become unstable, in a worst‐case scenario. One of the promising approaches to solving this problem is to switch the controller according to the state of the closed‐loop system. No useful design strategy for each controller, however, has yet been developed. In addition, the determination of the controller state at the instant of controller switching has not been investigated. First, this paper presents a new design methodology which merges the switching control and H_∞ controller design into one design algorithm. Second, this paper presents a way of determining the controller state at the instant of controller switching. Finally, the proposed method is applied to force control of a one‐DOF manipulator in order to demonstrate the usefulness of the proposed method. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 68–75, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10082     

Direct fractionation of proteins in particle-containing feedstocks by a filter paper pieces-based DEAE-cellulose column chromatography. Rapid, robust and low-cost capturing procedure for protein

Goldfish were classically conditioned to a mixture of two pulse trains differing in both repetition rate and the spectral profile of the pulses. Animals were then tested for generalization to single pulse trains having one or the other spectral profile presented at a variety of repetition rates. Generalization functions of repetition rate were qualitatively similar to those obtained following conditioning to either of the pulse trains alone. Thus, the spectral profile of each pulse type was appropriately associated with the repetition rate at which that pulse type was presented during conditioning. These results indicate that the two concurrent pulse trains making up the conditioning stimuli were analyzed independently, forming two auditory streams. When either of the two pulse trains were presented with a 500 ms onset asynchrony, stream segregation was enhanced. These and other results suggest that many fundamental features of the human sense of hearing are widely shared among vertebrate animals, and may have developed first among fishes.     

Sex differences in oxidative damage in ddY mouse kidney treated with a renal carcinogen, iron nitrilotriacetate

Iron-induced free radical injuries in male and female ddY mice, especially the sex difference and its mechanisms, were studied after an i.p. injection of a renal carcinogen, ferric nitrilotriacetate. Male mice were much more susceptible to iron-induced free radical injuries than female mice. Oxidative modification of proteins and DNA occurred more strongly in males than in females, as measured by protein carbonyl content and 8-hydroxydeoxyguanosine, respectively. Histochemical detection of 4-hydroxy-2-nonenal-modified proteins using an antibody and DNA fragmentation as detected by the TUNEL method also showed that males are more severely damaged than females, especially in the proximal convoluted tubules. These results could not be explained by the difference in iron status between male and female mice. In fact, the toxic so-called 'free' iron in serum and kidney were not different between male and female mice and storage iron, such as ferritin and hemosiderin, was also comparable in both kidneys. In previous studies we proposed the glutathione cycling hypothesis to explain the sex differences. The half-life of glutathione in the kidney was significantly shorter in males (29 min) than in females (57 min), as determined by the glutathione decrease after buthionine sulfoximine treatment, a specific inhibitor of glutathione synthesis. The specific activity of gamma-glutamyltranspeptidase (EC 2.3.2.2) in female mice was 73% of that in male mice. These results suggest that the faster glutathione turnover in males could account for the higher susceptibility to oxidative injury by supplying the reducing equivalent that reduces Fe(III) to Fe(II), thereby facilitating iron-catalyzed free radical reactions.     

Differences in muscle and fat accretion in Japanese Black and European cattle

The development of different muscles and adipose tissues during growth was investigated in commercial Japanese Black (JB) cattle and compared with breeds of the largest variation to be found in Europe. Animals, reared under typical conditions for Japanese and European beef production systems, gained similar body weights but different carcass composition at 24 months of age. The carcass of JB contained more adipose tissue and the least proportion of muscle. The longissimus muscle of JB developed extraordinary amounts of 23.3% intramuscular fat (IMF) at 24 months of age, compared from 0.6% to 4.7% in European breeds. The relationships between IMF content in the longissimus muscle and different adipose tissue weights indicate that a large amount of “waste fat” is accreted with every percent of IMF. However in JB, the good ability of IMF deposition is associated with relatively least development of “waste fat”, as a result of unique breed characteristics combined with special feeding system.     

The spontaneous formation of a J-like aggregate in Langmuir-Blodgett films of a squarylium dye

The physical properties of chalcogenide-containing squarylium (SQ) dyes with long alkyl chains were examined. The SQ dyes were deposited as Y-type films. The SQ dye of a 6-methylselenazole derivative spontaneously forms a J-like aggregate in Langmuir-Blodgett films at ambient conditions.     

Successful pregnancy in a patient with heart failure secondary to aortic and mitral regurgitation

The transmembrane nature of the receptor-like protein tyrosine phosphatases (PTPases) suggests that they transduce as yet unidentified extracellular signals to intracellular events via a phosphotyrosyl-protein dephosphorylation step, although little is known of their regulation and cellular activities. Structure/function studies of PTP alpha demonstrate that both catalytic domains are required for full enzymatic efficiency and that interdomain interactions may modulate PTP alpha activity and specificity. Overexpression of PTP alpha results in cell transformation and tumorigenesis, likely as a consequence of the ability of PTP alpha to dephosphorylate and activate the c-src tyrosine kinase. This suggests a role for PTP alpha in normal cell proliferation. PTP alpha is so far unique among the PTPases in terms of its oncogenic potential, and overexpression or deregulation of PTP alpha may be involved in the genesis, progression or maintenance of certain tumor states.     

Electron spin resonance study of Langmuir-Blodgett films of N-docosylpyridinium- di(tetracyanoquinodimethane)

An electron spin resonance (ESR) investigation is performed on Langmuir-Blodgett films consisting of a surface-active 1:2 complex of N-docosylpyridinium and tetracyanoquinodimethane (TCNQ), whose temperature-dependent spin susceptibility has been so far found to be consistent with the random-exchange Heisenberg antiferromagnetic chain (REHAC) model of Soos and Bondeson. An out-of-plane anisotropy in the ESR spectra shows that the long axes of TCNQ molecules are preferentially oriented along the plane normal to the sample, where the negligible in- plane anisotropy indicates the random distribution of the short and the pπ orbital axes in the film plane. A heat treatment applied to the samples results in an increase in the concentration of disorder, showing the possibility of controlling it in the present REHAC system.     

Detection of Mg(2+)-dependent endonuclease activity in myeloid leukemia cell nuclei capable of producing internucleosomal DNA cleavage

We detected Mg(2+)-dependent, Ca(2+)-independent endonuclease activity in non-apoptotic myeloid leukemia cell nuclei using autodigestion method which cleaved the chromatin of the autologous leukemia cells to an oligonucleosomal length pattern. Similar endonuclease activity could be successfully recovered in the protein extracts of the human leukemia cell nuclei. The extracts consistently elicited characteristic DNA cleavage of another leukemia cell (KG-1) nuclei as the target, the enzyme activity of which had been inactivated. We propose that this method is a useful tool for the study of endonucleases involved in apoptosis.