Use of a YAP1 overexpression cassette conferring specific resistance to cerulenin and cycloheximide as an efficient selectable marker in the yeast Saccharomyces cerevisiae.

Drug-resistance markers for yeast transformation are useful because they can be applied to strains without auxotrophic mutations. However, they are susceptible to technical difficulties, namely lower transformation efficiency and the appearance of drug-resistant mutants without the marker. To avoid these problems, we have constructed a phosphoglycerate kinase (PGK) promoter-driven YAP1 expression cassette, called PGKp-YAP1. Yeast cells containing PGKp-YAP1 were resistant to cycloheximide, a protein synthesis inhibitor, and also to cerulenin, a fatty acid synthesis inhibitor, but not to other drugs tested. The transformation efficiency of PGKp-YAP1 using cerulenin selection was comparable to that using a URA3 auxotrophic marker when low concentrations of cerulenin were used. Non-transformed drug-resistant colonies did appear on the low-concentration cerulenin plates. However, these non-transformed colonies could easily be identified, based on their cycloheximide sensitivity and/or their resistance to aureobasidin A to which the transformants were sensitive. Therefore, the dual drug resistance of PGKp-YAP1 could be used as an effective selection for PGKp-YAP1 recipient cells. The PGKp-YAP1 marker was used to disrupt the LYS2 gene and to transform an industrial yeast strain, indicating that this marker can be used for efficient and reliable gene manipulations in any Saccharomyces cerevisiae strain.     

Stability analysis of networked control systems subject to packet-dropouts and finite-level quantization

This paper is concerned with the stability analysis of a networked control system, wherein communication from the controller to the plant input is through a digital channel subject to packet-dropouts and finite-level quantization. No acknowledgments of receipt are available to the controller. To alleviate the effect of packet-dropouts, the controller transmits tentative plant input sequences. Within this setup, we derive a sufficient condition for small ?^∞ signal ?^∞ stability of the networked control system. This condition requires the maximum number of consecutive packet-dropouts to be bounded. We also elucidate the trade-off which exists between the disturbance attenuation and the step size of the quantizer and the maximum number of consecutive packet-dropouts.     

Identification of piecewise affine systems based on statistical clustering technique

This paper is concerned with the identification of a class of piecewise affine systems called a piecewise affine autoregressive exogenous (PWARX) model. The PWARX model is composed of ARX sub-models each of which corresponds to a polyhedral region of the regression space. Under the temporary assumption that the number of sub-models is known a priori, the input-output data are collected into several clusters by using a statistical clustering algorithm. We utilize support vector classifiers to estimate the boundary hyperplane between two adjacent regions in the regression space. In each cluster, the parameter vector of the sub-model is obtained by the least squares method. It turns out that the present statistical clustering approach enables us to estimate the number of sub-models based on the information criteria such as CAIC and MDL. The estimate of the number of sub-models is performed by applying the identification procedure several times to the same data set, after having fixed the number of sub-models to different values. Finally, we verify the applicability of the present identification method through a numerical example of a Hammerstein model.     

Formal representation of summary tables for health care statistical database management

There is an ever-increasing demand for statistical information in health-care societies, and voluminous statistics are collected every year. When one needs information on survey results, it is generally not allowed to access the original data, and the summary tables are the most important source of information which can be shared. In order to store summary tables as a well-organized database and to perform flexible retrieval, a formal study has been made on the structure of summary tables. We introduce the notion of summary table scheme and define the operations called table transformation. A statistical database management system has been implemented based on the study. In our study, a statistical database is a collection of summary tables obtained from a survey. If a survey is conducted periodically, a database consists of all the tables obtained in the past. System utilities have been implemented for handling time-oriented information.     

Evaluation of highly damaged renal function following extracorporeal circulation--usefulness of alpha 1-microglobulin index

The patients with highly damaged renal functions following extracorporeal circulation (ECC) were reviewed. Markers such as serum and urine creatinine (SCr, UCr), blood urea nitrogen (BUN), alpha 1-microglobulin in urine (as a marker of renal tubular function, abbreviated as U alpha 1-m), microalbumin in urine (as a marker of renal glomerular function, abbreviated as UA1b) were measured in each cases. Twenty patients were selected with the maximum value of U alpha 1-mover 60 micrograms/dl during or after ECC. The patients were classified into three groups according to preoperative value of alpha 1-m index (alpha 1-m index (I) = U alpha 1-m/UCr x 100 mg/g Cr), and Albumin index (Albumin index (I) = UA1b/UCr x 100 mg/g Cr). Group I (n = 13); alpha 1-m I > 10 and, Alb I > or = 50 (abnormal value of tubular and glomerular function), Group II (n = 3); alpha 1-m I < or = 10, Alb I > or = 50 (abnormal value of glomerular function), Group III (n = 4); alpha 1-m I < or = 10, Alb I < 50 (normal value of tubular and glomerular function). Six patients in Group I required postoperative hemodialysis (HD) and one patient in Group II. No one required HD in Group III. These facts suggest that preoperative damage of tubular and glomerular functions may become prolonged or irreversible damages may occur after operation. HD is required frequently in patients with alpha 1-m I level over 500 mg/g Cr, especially continuous HD may be needed in patient with alpha 1-m I level over 1000 mg/g Cr.     

Probabilistic output admissible set for systems with time-varying uncertainties

This paper considers time-varying uncertain constrained systems, and develops a method for computing a probabilistic output admissible (POA) set. This set consists of the initial states probabilistically assured to satisfy the constraint. The time-invariant counterpart has already been investigated in Hatanaka and Takaba [Computations of probabilistic output admissible set for uncertain constrained systems, Automatica 44 (2) (2008), to appear]. We first define the POA set for time-varying uncertainties with finite dimensional probability space. Then, we show that an algorithm similar to Hatanaka and Takaba [Computations of probabilistic output admissible set for uncertain constrained systems, Automatica 44 (2) (2008), to appear] provides the POA set also in the time-varying case, as long as an upper bound of a what we call future output admissibility (FOA) index is available. We moreover present two methods for computing the upper bound of the FOA index: probabilistic and deterministic methods. A numerical simulation demonstrates the effectiveness of our algorithm.     

An Elucidation of the Interaction Between Pt Particles and CeO2 Surfaces Using Tight-Binding Quantum Chemistry Method

To investigate the interaction between Pt particle and CeO₂ surface, we applied tight-binding quantum chemistry method to the study of electron and bonding state of Pt/CeO₂ system. We observed that the electron transfer between Pt and CeO₂ and the reduction of the Ce atoms influences the stability of Pt particle on CeO₂ surface.     

Performance optimization of two-staged gasification system for woody biomass

The performance of a small-scale two-staged gasification system is reported. In this system wood chips are gasified with a fixed bed gasifier and then tar in the produced gas is reformed in a non-catalytic reformer, finally the production gas is used to generate electricity. In this system, the gasifying agents are high temperature air and steam supplied into the gasifier and the reformer. This paper reports on optimum gasification air ratio (defined as the ratio of the oxygen mole supplied into the gasifier to the oxygen mole required for complete combustion of biomass), reforming air ratio (defined as the ratio of the oxygen mole supplied in the reformer to the oxygen mole required for the complete combustion of biomass) and steam ratio (defined as the ratio of the steam mole supplied into the gasifier to the carbon mole in biomass supplied into the gasifier) for producing required gas supplied into a dual-fueled diesel engine. The results showed that, under optimum conditions, the higher heating value of the reformed gas was 3.9 MJ/m³_N; the cold gas efficiency (defined as the ratio of HHV reformed gas × reformed gas flow rate to HHV biomass × biomass feed rate) of the gasification system was 66%, and the gross thermal efficiency of the overall system was 27%.     

Electronic structure and electrical conductivity of MgO protecting layer in plasma‐display panels: A tight‐binding quantum chemical study

Abstract— The tight‐binding quantum chemical molecular dynamics code, Colors, has been successfully applied to the electronic‐structure calculations of the MgO‐protecting‐layer model in plasma‐display panels (PDPs). The code succeeded in reproducing the band‐gap energy of the MgO crystal structure. The energy gap between the bottom of the conduction band (CB) and the top of valence band (VB) was 7.45 eV, which is in quantitative agreement with the experimental and previous theoretical results. The electronic structure of the undoped MgO model and Si‐doped MgO model was also calculated. The impurity level was 2.15 eV lower than that for the bottom of the CB. This result was in qualitative agreement with recent cathodoluminescence measurements. In addition, we have already succeeded in developing a novel electrical conductivity simulator using the spatial distribution of the probability density of wave functions obtained from the tight‐binding quantum chemical molecular dynamics code, Colors. The electrical conductivity of the MgO‐protecting‐layer model was estimated with and without an oxygen defect and a significant change in the electrical conductivity of the MgO‐protecting‐layer materials was observed with the introduction of oxygen defects.