Overexpression of the robA gene increases organic solvent tolerance and multiple antibiotic and heavy metal ion resistance in Escherichia coli

Escherichia coli K-12 OST3410 was isolated previously as a stable cyclohexane-tolerant mutant derived from cyclohexane-sensitive strain JA300. A plasmid which provides cyclohexane tolerance to strain JA300 was isolated from the OST3410 genomic library. Subcloning and sequence analysis showed that the plasmid contained the robA gene, whose gene product was reported to bind specifically to the right border of oriC. We observed that the robA gene on the multicopy plasmid generally increased the organic solvent tolerance of several E. coli strains. We also observed an increase in the organic solvent tolerance of JA300 carrying the lac-robA fusion gene on a low-copy plasmid by isopropyl-beta-D-thiogalactopyranoside induction. Strain JA300 carrying the multicopy robA plasmid also showed an increase in resistance to a number of unrelated antibiotics and heavy metal ions, and the spectrum of resistance was significantly similar to that of the soxS-overexpressing strain.     

A low communication competitive interactive proof system for promised quadratic residuosity

Bellare and Goldwasser showed that if the modulus N is guaranteed to be the product of O(log log ¦N¦) distinct odd primes, then quadratic residuosity has a competitive interactive proof system (with reasonably large communication complexity). In this paper we show that if the modulus N is guaranteed to be the product of O(log ¦N¦) distinct odd primes, then quadratic residuosity has a competitive interactive proof system with low communication complexity.     

Biocatalysis as a Rational Approach to Enantiodivergent Synthesis of Highly Oxygenated Compounds: (+)- and (—)-Pinitol and Other Cyclitols

Bacterial oxygenation of halogenated aromatic compounds yields arene cis-diols of type 2 of high enantiomeric purity. Further oxygenation of these extremely versatile synthetic intermediates provides for stereo- and regioselective introduction of additional functionalities such as hydroxyl groups. Several rational methods of oxygenation (epoxidation, osmylation, singlet oxygen addition, and ozonolysis) are used to produce, in short synthetic routes, cyclitol derivatives of medicinal importance. Proper symmetry considerations lead to the development of enantiodivergent synthetic design of target compounds from a single enantiomer of a starting diol. These principles are illustrated on the short syntheses of (+)- and (-)-pinitol. Stereocontrolled oxidative transformation of diols of type 2 are exemplified in the synthesis of conduritol C and dihydroconduritol C. Full experimental details are provided for all compounds. A guide to the stereorational design of any stereoisomer of cyclohexane (poly)ols or carbohydrates is provided at the end of the paper.     

Microcomputer engine controls

Many studies on the automotive engine as a control system have been investigated in order to meet emission regulations and to improve the fuel economy. Sophisticated control systems which, up to the introduction of the microcomputer were a problem, are now easy to realize.

In this paper, the fuel supply and ignition timing are considered as the principal control variables of the automotive engine. The main feature of a carburetor is characterized by its Venturi geometry and fuel nozzle arrangement. The ignition timing is controlled by a distributor which is composed by a spring and a centrifugal governor.     

Orally administered prostaglandin E1 derivative can enhance liver regeneration in partially hepatectomized rats

The effect of orally administered 17(S),20-dimethyl-6-oxo prostaglandin E1 (PGE1) methyl ester (OP) on liver regeneration was examined in 66% hepatectomized rats. Administration of OP increased the mitotic index of the hepatocyte 3 days after hepatectomy, and the mitotic index response due to OP was dose dependent. The OP administration had no effect on food intake, but reduced water intake. The serum scores relative to nutrition and hepatic function showed transient change after OP administration, whereas the serum blood urea nitrogen level indicated a slight renal dysfunction with OP. The fat store in the body was transiently reduced. These observations lead us to conclude that orally administered OP is capable of stimulating liver regeneration without serious systemic effects.     

Effects of capacitance at crossover wirings in power GaAs m.e.s.f.e.t.s.

Power GaAs f.e.t.s. with an air-bridge crossover were compared with those of SiO2 crossover to find the effect of the capacitance at the crossover points. The capacitance of SiO2 crossover points is much smaller than that of the gate pad or the gate busbar in power GaAs f.e.t.s, and deterioration of the microwave performance due to that capacitance is negligible.     

An image signal multiprocessor on a single chip

A digital image signal multiprocessor (ISMP), a multiprocessor version of a previous real-time image signal processor (RISP) for gray-level image processing, is discussed. It is composed of a main controller and four processor elements (PEs), which are programmable 12-b digital signal processors. One PE has the processing speed of 50-million microinstructions-per-second. The ISMP has 200-million microinstructions-per-second performance using parallel processing with a round-robin method for local image processing. In the other operation mode, each PE processes the same image data with different feature-extracting programs. In addition, system processing power can be easily increased through a novel multichip processing mode. It has 30000 transistors on a 14.4-mm×13.7-mm chip using 1.2-μm double-metal CMOS process technology. Its power dissipation is 2.9 W     

GaAs power m.e.s.f.e.t.s. with a graded recess structure

A new recess structure device was developed to improve the field distrubution and therfore the performance of GaAs power m.e.s.f.e.t.s. The linear gain and the output power were improved by 1?2 dB for this structure. The highest output powers obtained are 15 W with 4 dB associated gain at 6 GHz, and 4.3 W with 3 dB associated gain at 11 GHz.     

Synthesis of diastereomeric mixture of 15,19,23-trimethylheptatriacontane,contact sex pheromone of tsetse fly,Glossina morsitans morsitans westwood

A nine-step synthesis is described for a diastereomeric mixture of 15,19,23-trimethylheptatriacontane, a contact sex pheromone ofGlossina morsitans morsitans Westwood. The compound has been synthesized by means of double alkylation of diethyl 3-oxoglutarate (DEOG) with 3-methyl-2-heptadecenyl methanesulfonate, which was readily prepared from 1-hexadecene, as the key step.This study constitutes Part XII of Selective Alkylation of Diethyl 3-Oxoglutarate. Part XI of this series, see Naoshima et al. (1984).