Long Time Behaviour of Unstable Multilevel Systems in Presence of Zero Energy Resonance

Long time behaviour of the survival probability for unstable multilevel systems is studied based on the N-level Friedrichs model in the presence of zero energy resonance, that means the divergence of the resolvent at zero energy. With resort to the technique developed by Jensen and Kato [Duke Math. J. 46, 583 (1979)], the zero energy resonance of this model is characterized by the zero energy eigenstate that does not belong to the Hilbert space. It is then shown that for some kinds of the form factors, logarithmically slower decay of the survival probability can be realized.     

Room temperature operation of GaInAs-GaInAsP-InP SCH multiquantum-film laser with narrow wire-like active region

GaInAs-GaInAsP-InP SCH (separate-confinement heterostructure) multiquantum-film lasers with approximately 100-nm-wide wirelike active regions were fabricated by two-step low-pressure organometallic vapor-phase epitaxy (LP-OMVPE) growth and wet chemical etching and operated at room temperature. An increase in the threshold current density in such lasers was drastically reduced by using a preheating process in hydrogen atmosphere and a thin InP cover layer growth prior to the regrowth of a GaInAsP optical confinement layer. The fabrication processes presented can be very effective for realization of room-temperature operation of long-wavelength quantum-wire and quantum-box lasers based on GaInAs-InP materials.<>     

Performance of digital radio communication system with BCH codingunder microwave oven interference

The performance of digital radio communication systems with a Bose-Chaudhuri-Hocquenghem (BCH) coding scheme under a microwave oven interference environment is investigated. Numerical results indicate that the performance cannot be improved by using only BCH codes but a large performance improvement can be obtained by using BCH codes combined with bit interleaving     

Digital wireless sensor server using an adaptive smart-antenna/retrodirective array

A wireless sensor server is developed based on a reconfigurable active smart-antenna/retrodirective array. The system can serve as both a retrodirective array transponder and a smart-antenna receiver simply by changing the frequency of the local oscillator applied to the mixers, enabling it to utilize its hardware best to suit its communication environment. When operating as a direct-conversion receiver, the receiver array successfully demodulates a quaternary phase-shift keying (QPSK) modulated signal with circuit gain of 7 dB, and E/sub b//N/sub 0/ for BER=10/sup -4/ is approximately 12 dB without any error correction. In the retrodirective array mode, the system provides 20 dB circuit gain and 20 dB radio-frequency/intermediate-frequency isolation at the center frequency as well as phase conjugation, exhibiting excellent retrodirectivity. The mixers perform phase conjugation and modulation simultaneously, enabling the transmission of locally stored data. The local data is successfully extracted by an interrogator.     

Involvement of calmodulin-dependent protein kinases-I and -IV in long-term potentiation

BACKGROUND: The Hemopump (DLP/Medtronic) has been in clinical use for about 7 years. There is still no adequate way of determining actual output from the three available pump systems in the clinical situation. If the pump is completely stopped during weaning from the device, there is a possibility of back-leakage through the pump, endangering the patient from regurgitation into the left ventricle. It can also make it more difficult to judge the recovery of heart function because of a volume load of the left ventricle. The aim of this study was to evaluate in a standardized, experimental in vitro model the output from three different-sized Hemopump catheters at various pressure levels and to quantify the back-flow through the pumps. METHODS: The Hemopump models were tested in an in vitro study regarding total outflow at various speeds at three pressure levels. The back-flow through the pumps was also measured with the pumps at a complete stop. RESULTS: The outflow from the Hemopumps ranged from 0.4 to 4.5 L/min, depending on which pump and speed were used. Variations in total output, depending on speed and various pressure settings, could be up to 0.4 L/min. Back-flow through the pump into the left ventricle may be as great as 1.6 L/min. CONCLUSIONS: The flow outputs from the different Hemopump models were reproducible over time and were closely related to the resistance of the model. The Hemopump, if not running, can induce substantial regurgitation through the pump into the left ventricle.     

WDM field trials of 43-Gb/s/channel transport system for optical transport network

This paper describes recent technical challenges and the progress toward the realization of the optical transport network (OTN) based on 43 Gb/s channel. We describe the new digital frame format "OTU3: Optical Channel Transport Unit 3," which is standardized in ITU-T for OTN, for the enhancement of the network management capability in the OTN based on 43-Gb/s channels. We first proposed 43-Gb/s/ch dense wavelength-division multiplexing (DWDM) dispersion-managed transmission system using carrier-suppressed return-to-zero (CS-RZ) format that has several attractive features; it advances the evolution of OTN into 100 GHz-spaced long-haul DWDM transport networks. The first wavelength-division multiplexing (WDM) field trials confirmed the superiority of CS-RZ format in the DWDM transmission performance for the first time. The first 1 Tb/s (25 /spl times/ 43 Gb/s) WDM field trial confirmed the excellent network management capability of OTU3 in future data-centric OTN using the newly developed 43-Gb/s OTN line-terminal prototype.     

Six patients in whom exacerbation of asthma was complicated by mediastinal emphysema

We encountered 6 patients with bronchial asthma complicated by mediastinal emphysema. Their average age was 21 years. All were atopic and had histories of asthma in childhood. In 5 of the 6, mediastinal emphysema developed when the patients had upper respiratory infections. In 3, the mediastinal emphysema worsened. After insertion of subcutaneous drains to decrease intramediastinal pressure, the conditions of those 3 patients improved remarkably. The conditions of the other 3 improved after medication only. During the period of this study, 1.24% of all patients treated at Hiroshima Asa Citizen's Hospital for exacerbations of asthma had mediastinal emphysema.     

Monoclonal antibodies against pig ovarian follicular granulosa cells induce apoptotic cell death in cultured granulosa cells

Two monoclonal antibodies capable of inducing granulosa cell apoptosis were produced against granulosa cells prepared from antral follicles of pig ovaries. The healthy follicles, 4-5 mm in diameter, were dissected from the ovaries of gilts, and then granulosa cells were isolated. BALB/c female mice were immunized with the isolated granulosa cells. Antibodies against the granulosa cells were detected by immunofluorescent staining using frozen ovarian sections. The isolated spleen cells prepared from immunized mice producing antibodies against the granulosa cells were fused with Sp2/O-Ag 14 mouse myeloma cells by standard hybridization techniques. Two hybridoma clones, PFG-1 and PFG-2, which produced specific IgM antibodies against granulosa cells were selected. Western blotting analysis revealed that PFG-1 and PFG-2 antibodies specifically recognized cell-membrane proteins with molecular weights of 55 and 70 kD and isoelectric points of 5.9 and 5.4, respectively. The monoclonal antibodies immunohistochemically reacted with granulosa cells of healthy follicles. When the isolated granulosa cells prepared from healthy follicles were cultured in medium containing 0.1 or 10 micrograms/m/PFG-1 or PFG-2 antibodies, respectively, the cells underwent apoptosis as determined by nuclear morphology, DNA electrophoresis and flow cytometric analysis. In conclusion, these two monoclonal antibodies against granulosa cells have cell-killing activity in cultured granulosa cells.     

Ultrahigh-speed driverless MQW intensity modulator, and 20 Gbit/s, 100 km transmission experiments

An InGaArInAlAs MQW modulator with the low voltage of 1.5 V for 10 dB extinction ratio and 16 GHz bandwidth has been developed. This ultrahigh-speed modulator enables the modulator driver to be eliminated from the transmitter. 100 km transmission experiments have been carried out using either a 1 V peak to peak output monolithic-IC-driven modulator at 15 Gbit/s or a 2 V peak to peak output multiplexer-driven modulator at 20 Gbit/s. This is the first report on multigigabit operation of MQW modulators to the authors' knowledge.<>     

Interpersonal Style and Japanese American Organizational Involvement

This paper reports on an initial effort to develop survey items that measure Japanese American interpersonal style. Based upon the theoretical work of Miyamoto. Fugita, and Kashima (2002) it was hypothesized that Japanese American interpersonal style is an important factor in their forming large numbers of voluntary organizations both historically and contemporarily. A survey was administered to 344 Japanese Americans living in the Seattle, WA and San Jose, CA areas. An initial pool of 16 items yielded a 10-item measure with three subscales that was related to involvement in Japanese American organizations and other indicators of ethnic community participation.