Pancyclicity of recursive circulant graphs

In this paper, we study the existence of cycles of all lengths in the recursive circulant graphs, and we show a necessary and sufficient condition for the graph being pancyclic and bipancyclic.     

Antiphospholipid antibody syndrome in a case with redo coronary artery bypass grafting under cardiopulmonary bypass

Until now 'c-series' polysialogangliosides were known to exist in human brain only during development and in some pathological conditions like Alzheimer's disease. Using thin-layer chromatography (TLC) and immunostaining with Q211 antibody (TLC-overlay technique) we have analysed 'c-series' gangliosides in four human cerebella (age 20, 47, 52 and 54 years). Four distinct ganglioside bands, most probably corresponding to GT1c, GQ1c, GP1c and GH1c were found to exist in the analysed brains, which is convincing demonstration of the existence of 'c-series' gangliosides in normal adult human brain. Immunohistochemical analysis was performed to locate polysialogangliosides in the analysed tissue. Q211 antibody was found to bind specifically to a single subpopulation of neurons in the molecular layer of adult cerebellum. According to their position and morphology these cells correspond to stellate neurons.     

A practical design of multiloop robust PID control systems

In this paper, a new design scheme of multiloop predictive self‐tuning PID controllers is proposed for multivariable systems. The proposed scheme first uses a static precompensator as an approximately decoupling device in order to roughly reduce the interaction terms of the controlled object. The static matrix precompensator is adjusted by an on‐line estimator. Furthermore, by regarding the approximately decoupled system as a series of single‐input single‐output subsystems, a single‐input single‐output PID controller is designed for each subsystem. The PID parameters are calculated on‐line based on the relationship between the PID control and the generalized predictive control laws. The proposed scheme is numerically evaluated on a simulation example. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 63–71, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10284     

A cellular automata model considering diversity associated with HIV infection

The diversity of human immunodeficiency virus (HIV) in vivo has been reported. In this article, we propose a cellular automata (CA) model describing the interactions between the immune system and HIV, and examine the effect of the diversity of these interactions. The novel aspects of our CA model are that it not only considers four states (HIV, virgin, dead, infect) but also the diversity exhibited by both HIV and T cells. We simulated maximum diversities for these states by simulating CA on a computer. The model revealed that increased diversity had the effect of increasing the HIV population and simulation steps. In addition, we observed that the CA model accurately reflects the occurrence of infection, incubation period, and the development of AIDS. The CA model demonstrated that the diversity of the virus is the major factor affecting the success rate of the escape of HIV from the immune response. This work was presented in part at the 10th International Symposium on Artificial Life and Robotics, Oita, Japan, February 4–6, 2005     

Micro method for stereospecific analysis of triacyl-sn-glycerols by chiral-phase high-performance liquid chromatography

A procedure for micro stereospecific analysis of triacyl-sn-glycerols (TGs) by high-performance liquid chromatography (HPLC) on a chiral column is presented. TGs were partially hydrolyzed with ethyl magnesium bromide, and total products were immediately converted to 3,5-dinitro-phenylurethane derivatives. Each of the 1- and 2-monoacylglycerol (MG) derivatives was isolated by HPLC on a silica column. The 1-MGs were resolved intosn-1 andsn-3 MG fractions by HPLC on a Sumichiral OA-4100 column (Sumitomo Chemical, Osaka, Japan). Fatty acid methyl esters obtained from thesn-1,sn-2 andsn-3 MG fractions were analyzed by gas-liquid chromatography on a capillary column. Analyses of standard TGs showed that, even with 1 mg of sample, accuracy was comparable to that obtained with 100-mg samples. Applying this procedure to the stereospecific analysis of 5 mg of jujube pulp, TGs revealed the positional distribution of the (n-5) series of monounsaturated fatty acids they contained. Honored Student Award Address presented at the 83rd AOCS Annual Meeting held in Toronto, Canada, May 10–14, 1992.     

Numerical simulation of the fountain flow problem for viscoelastic fluids

Fountain flow for isothermal viscoelastic fluids is simulated by a numerical method based on a combination of a finite element method and a finite volume method. For the treatment of moving free surfaces, a fringe element generation method is used. Circulating flow and elongation in the transverse direction at the melt front are simulated well. Numerical results also suggest that circulation in fountain flow and viscoelastic retardation may give rise to symmetric V-shaped patterns of birefringence between the center-plane and wall. Such information on molecular orientation in fountain flow is important for physical properties of thick molded products.     

Efficient production of L‐lactic acid by Crabtree‐negative yeast Candida boidinii

Industrial production of L ‐lactic acid, which in polymerized form as poly‐lactic acid is widely used as a biodegradable plastic, has been attracting world‐wide attention. By genetic engineering we constructed a strain of the Crabtree‐negative yeast Candida boidinii that efficiently produced a large amount of L ‐lactic acid. The alcohol fermentation pathway of C. boidinii was altered by disruption of the PDC1 gene encoding pyruvate decarboxylase, resulting in an ethanol production that was reduced to 17% of the wild‐type strain. The alcohol fermentation pathway of the PDC1 deletion strain was then successfully utilized for the synthesis of L ‐lactic acid by placing the bovine L ‐lactate dehydrogenase‐encoding gene under the control of the PDC1 promoter by targeted integration. Optimizing the conditions for batch culture in a 5 l jar‐fermenter resulted in an L ‐lactic acid production reaching 85.9 g/l within 48 h. This productivity (1.79 g/l/h) is the highest thus far reported for L ‐lactic acid‐producing yeasts. DDBJ/EMBL/GenBank nucleotide database with Accession Nos. AB440630 and AB440631. Copyright © 2009 John Wiley & Sons, Ltd.     

Catalytic combustion technology to achieve ultra low NOx, emissions: Catalyst design and performance characteristics

A catalytic combustion system has been developed which feeds full fuel and air to the catalyst but avoids exposure of the catalyst to the high temperatures responsible for deactivation and thermal shock fracture of the supporting substrate. The combustion process is initiated by the catalyst and is completed by homogeneous combustion in the post catalyst region where the highest temperatures are obtained. Catalysts have been demonstrated that operate at inlet temperatures as low as 320°C at 11 atm total pressure and conditions typical of high performance industrial gas turbines. The ignition temperature is shown to correlate with the specific catalytic activity of the washcoat layer over a rather broad range of activities. A reaction model has been developed that can predict ignition behavior from the measured catalytic activity.     

Diminished expression of CD40 ligand may contribute to the defective humoral immunity in patients with MHC class II deficiency

Major histocompatibility complex (MHC) class II deficiency (bare lymphocyte syndrome, BLS) is a rare primary immunodeficiency classified as a subgroup of severe combined immunodeficiency. We studied T and B lymphocyte function by examining the CD40 ligand/CD40 system in three BLS patients from two unrelated families. CD40 ligand expression by maximally activated BLS T cells was diminished. This abnormality may represent immunological na?veté rather than a general T cell defect, since expression of activation marker CD69 and proliferative responses to PHA or anti-CD3 were normal, and BLS T cells primed and restimulated in vitro expressed normal amounts of CD40 ligand. BLS B cells proliferated and produced IgE if stimulated with anti-CD40 or soluble CD40 ligand and IL-4. Activation of BLS B cells with soluble CD40 ligand and IL-4 induced normal expression of activation markers, although MHC class II expression remained absent. Depressed antibody titers, lack of amplification and failure to undergo isotype switching in response to immunization with bacteriophage phi x 174 demonstrated defective T cell help. We conclude that BLS B cells are functionally normal if appropriately stimulated, and that the defective humoral immunity observed may be related to diminished expression of CD40 ligand on BLS T cells.     

Rapid separations of diacyl- and dialkylglycerol enantiomers by high performance liquid chromatography on a chiral stationary phase

Rapid and practical separations of 1,2-and 2,3-diacyl-and dialkyl-sn-glycerol enantimers as their 3,5-dinitrophenylurethane derivatives were carried out by normal-phase high performance liquid chromatography on a chiral stationary phase, N-(R)-1-(α-naphthyl)ethylaminocarbonyl-(S)-valine chemically bonded to γ-aminopropyl silanized silica. Complete separations of the racemates into enantiomers were achieved for both of the diacyl-and dialkylglycerols within 10 min using a stainless steel column (25 cm long) packed with the 5-μ particles, an isocratic elution with a mixture of hexane/ethylene dichloride/ethanol as a mobile phase and a UV detector. Thesn-1,2-enantiomers were eluted ahead of the correspondingsn-2,3-enantiomers. Satisfactory separation of thesn-1,3-diacylglycerols from the corresponding enantiomers and the separation of the homologues differing in acyl and alkyl groups were also observed. The formations of hydrogen bonding and charge transfer complex between the urethane derivatives and the stationary phase may contribute to the enantiomer separations.