Effect of nicotine, lobeline, and mecamylamine on sensory gating in the rat

In normal subjects, if an acoustic startle stimulus is immediately preceded by a small brief change in background noise intensity, the magnitude of the subsequent startle response is decreased. This prepulse inhibition (PPI) of an acoustic startle response has been shown to be associated with sensorimotor gating. PPI is disrupted in schizophrenic patients and has been linked to attentional disorders characteristic of this disease. We tested the effects of (-)-nicotine, (0.19, 0.62, and 1.9 mumol/kg IP) (equivalent to 0.03, 0.1, and 0.3 mg/kg base) and the nicotinic cholinergic receptor (nAChR) channel blocker, mecamylamine (5.0 and 50 mumol/kg IP) (equivalent to 1.0 and 10.0 mg/kg) on PPI of the acoustic startle response in the rat. Nicotine increased the PPI at the lowest prepulse signal levels but not at the stronger levels. Mecamylamine was without effect at 5.0 mumol/kg, but the 50 mumol/kg dose decreased the inhibition at both weak and strong prepulse (PP) levels. Mecamylamine (5.0 mumol/kg) pretreatment did not block the (-)-nicotine-induced increase in PPI. Lobeline (0.19, 0.62, 1.9, and 6.2 mumol/kg IP) (equivalent to 0.071, 0.23, 0.71, and 2.3 mg/kg) was without effect. These results are consistent with a mecamylamine-insensitive effect of nicotine to improve gating in normal rats. The nAChR subtype involved in producing nicotine's increase of PPI needs further investigation.     

Sulfation of parabens and tyrosylpeptides by bacterial arylsulfate sulfotransferases

Arylsulfate sulfotransferase purified from Eubacterium A-44 has higher specific activity than the enzymes from Klebsiella K-36 and Haemophilus K-12. Propylparaben and butylparaben were good substrates among several parabens. The antibacterial activity of parabens was reduced by the sulfation of the phenolic hydroxy group. Tyrosine-containing peptides, kyotorphin, enkephalin and cholecystokinin non-sulfate, were effective as acceptor substrates by A-44, K-36 and K-12 sulfotransferases.     

The rank one mixed μ problem and ‘kharitonov-type’ analysis

The general mixed μ problem has been shown to be NP hard, so that the exact solution of the general problem is computationally intractable, except for small problems. In this paper we consider not the general problem, but a particular special case of this problem, the rank one mixed μ problem. We show that for this case the mixed μ problem is equivalent to its upper bound (which is convex), and it can in fact be computed easily (and exactly). This special case is shown to be equivalent to the so-called ‘affine parameter variation’ problem (for a polynomial with perturbed coefficients) which has been examined in detail in the literature, and for which several celebrated ‘Kharitonov-type’ results have been proven.     

Kinetics of zinc oxide formation from zinc sulfide by reaction with lime in the presence of water vapor

A novel reaction scheme for transforming certain metal sulfides to the corresponding oxides has been developed. In this process, steam oxidizes the sulfide into the oxide, and the hydrogen sulfide produced reacts with lime to form calcium sulfide and regenerate steam. There is no net consumption or generation of gaseous species. Thus, the overall reaction can be carried out in a closed system as far as the gas phase is concerned. This eliminates the possibility of emitting hydrogen sulfide out of the reactor. Only certain metal sulfides are thermodynamically amenable to this treatment. In this paper, the reaction of ZnS to ZnO by this scheme is described, together with a detailed formulation of the rate equation for the overall reaction based on the kinetics of the component gas-solid reactions. Although the present work was done with CaO, other suitable oxides may be used in its place. A further potential application of this process is to the selective oxidation of certain sulfide(s) from complex sulfide ores as a treatment prior to the separation of minerals.     

Design,Implementation, and Validation of KOMPSAT‐2 Software Simulator

In this paper, we present design features, implementation, and validation of a satellite simulator subsystem for the Korea Multi‐Purpose Satellite‐2 (KOMPSAT‐2). The satellite simulator subsystem is implemented on a personal computer to minimize costs and trouble on embedding onboard flight software into the simulator. An object‐oriented design methodology is employed to maximize software reusability. Also, instead of a high‐cost commercial database, XML is used for the manipulation of spacecraft characteristics data, telecommand, telemetry, and simulation data. The KOMPSAT‐2 satellite simulator subsystem is validated by various simulations for autonomous onboard launch and early orbit phase operations, anomaly operation, and science fine mode operation. It is also officially verified by successfully passing various tests such as the satellite simulator subsystem test, mission control element system integration test, interface test, site installation test, and acceptance test.     

A 4-MB on-chip L2 cache for a 90-nm 1.6-GHz 64-bit microprocessor

A 4-MB L2 data cache was implemented for a 64-bit 1.6-GHz SPARC(r) RISC microprocessor. Static sense amplifiers were used in the SRAM arrays and for global data repeaters, resulting in robust and flexible timing operation. Elimination of the global clock grid over the SRAM array saves power, enabled by combining the clock information with array select signals. Redundancy was implemented flexibly, with shift circuits outside the main data array for area efficiency. The chip integrates 315 million transistors and uses an 8-metal-layer 90-nm CMOS process.     

Single fundamental mode photonic crystal vertical cavity laser with improved output power

The single fundamental mode output power of photonic crystal vertical cavity lasers is improved by varying sizes of oxide apertures and defect lasing apertures. A maximum output power of 3.1 mW in the fundamental mode has been achieved with a new fabrication process that involves only focused ion beam etching to create holes in selectively oxidised VCSELs.     

A four-channel 3.125-Gb/s/ch CMOS serial-link transceiver with a mixed-mode adaptive equalizer

This work presents a quad-channel serial-link transceiver providing a maximum full duplex raw data rate of 12.5Gb/s for a single 10-Gbit eXtended Attachment Unit Interface (XAUI) in a standard 0.18-/spl mu/m CMOS technology. To achieve low bit-error rate (BER) and high-speed operation, a mixed-mode least-mean-square (LMS) adaptive equalizer and a low-jitter delay-immune clock data recovery (CDR) circuit are used. The transceiver achieves BER lower than <4.5/spl times/10/sup -15/ while its transmitted data and recovered clock have a low jitter of 46 and 64 ps in peak-to-peak, respectively. The chip consumes 178 mW per each channel at 3.125-Gb/s/ch full duplex (TX/RX simultaneous) data rate from 1.8-V power supply.     

Effects of various post-treatments on carbon nanotube films for reliable field emission

In this report, the FE characteristics of carbon nanotubes (CNTs) treated using both thermal annealing and mechanical coatings on the as-grown CNTs systematically studied. It was found that in the high temperature annealed samples, CNTs were attacked at its root during annealing due to a small amount of oxygen, and were pulled out of the substrate in places after FE measurements because of the contact resistance. However, for the mechanically coated samples both with spin on glass (SOG) and polymethyl methacrylate (PMMA), CNTs were found to be nearly intact after FE measurements and showed reliable FE characteristics over repeatable voltage scan. The reliability of CNTs during FE could be owing to the strong adhesion of CNTs to the substrate both by SOG and PMMA coatings.