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A DC component contained in an output of a voltage source self-commutated converter causes a converter transformer to be DC-magnetized, in the worst case causing an overcurrent due to saturation. We experienced the DC-magnetization of the converter transformer of a 50 MVA self-commutated SVC installed in the Shinshinano Substation of Tokyo Electric Power Company when system disturbances occurred by energizing of an adjacent large capacity transformer. After analysing the problem, a novel DC magnetization prevention control was developed that makes a fast flux correction according to the voltage DC component detected in the converter output. This method was applied to the 50 MVA self-commutated SVC and produced satisfactory operation results.

We propose an over-gigabit visible light indoor transmission system employing a quasi-phase-matching (QPM) device. To enhance the transmission characteristic of the proposed system, we employ a collecting lens at the receiver (Rx). The applicability to over-gigabit indoor visible light transmission was investigated with a 1 and 2 m free space transmission experiments. The experimental results confirmed that we realized bit error rate (BER) 10−11 operation. The results also confirmed that the use of a collecting lens at the Rx was effective for the diffusion of visible light.

A 1.5-dB gain-flatness over 67 nm is achieved with a novel hybrid amplifier comprised of a distributed Raman amplifier pumped at two wavelengths and an erbium-doped fluoride fiber amplifier. Fourteen 2.5-Gb/s signals spanning 65 nm are successfully transmitted over 900 km using the new amplifiers. Low-noise characteristics compared to the same transmission line with discrete erbium-doped fiber amplifiers are also confirmed.

The development of type 2 diabetes is associated with the impairment of insulin secretion. To evaluate the evolution of the secretory response, a chronological study comparing normal Wistar (W) vs Goto-Kakizaki (GK) rats, an animal model of non obese type 2 diabetes, was done. Glucose and arginine were tested in collagenase isolated islets of Langerhans with perfusion and ELISA immunoassay techniques. Fasting glycaemia and insulinemia and glucose tolerance were also evaluated. We have seen, in W rats, a mild glucose intolerance in the first two weeks of age. GK rats were always glucose intolerant with hyperglycaemia and hyperinsulinemia at fasten after one month old. Wistar islets had a characteristic biphasic response to glucose after the first two weeks of age. GK islets were always glucose irresponsive. Arginine induced an increase in insulin secretion in both animal models, independent of age, although GK rats had always a smaller response when compared to W rats. We concluded that 1) in W rats, a biphasic insulin secretion in response to glucose is observed after the first two weeks of age, simultaneously with glycaemia stabilization 2) in GK rats, both first and second phases of glucose-induced insulin release are significantly reduced and a smaller reduction in response to arginine is observed. This beta-cell disfunction is a primary event in this model of type 2 diabetes, preceding fasting hyperglycaemia and hyperinsulinemia.

The impairment of insulin secretion, a major feature of type 2 diabetes, is caused by beta-cell mass reduction and functional failure. Pancreatic beta-cell mass reduction is variable in humans, not exceeding 50%, and has been associated with amyloid deposits. In the present study, we have chronologically compared the endocrine pancreas morphology of Wistar control rats (W) and Goto-Kakizaki (GK) rats, an animal model of non obese type 2 diabetes. We have also characterised and compared their body weight, glycaemia (fasting and after oral glucose load) as well as other biochemical parameters. GK rats were always glucose intolerant and fasting hyperglycaemia arised at four week of age. Wistar rats had mild glucose intolerance in their first two weeks of life. GK rats had a total beta-cell mass always decreased when compared to controls, but above 40%. In adult GK rats (12 weeks old) alterations in the architecture of a sub-population of islets occurred which displayed signs of prominent fibrosis, with cluster of beta-cells widely separated by strands of connective tissue and deposits of PAS positive material. Our findings demonstrate that, using GK rats from the Coimbra colony, beta-cell mass reduction is one of the primary features in the pathological sequence leading to diabetes. Structural lesions of the islets, that will further increase beta-cell mass reduction and compromise beta-cell function, will appear latter mainly due to hyperglycaemia.

Summary form only given. Wideband optical amplifiers are the key devices to enlarge the capacity of WDM transmission systems. Several approaches have been investigated to broaden and flatten the gain band of fibre amplifiers, including combining a gain-flattened erbium-doped silicate fiber amplifier (EDSFA) with Raman amplification in the transmission fiber. This approach is quite effective to extend the gain band to longer wavelengths because the Raman gain counterbalances the decrease in the EDSFA gain. We achieve the extremely large 3-dB gain bandwidth of 75 nm (1531-1606 nm) with a novel configuration. A wideband and gain-flattened erbium-doped fluoride fiber amplifier is combined with an internal Raman amplifier using a high-NA germano-silicate fiber (Raman fiber). Error-free operation in a WDM (9/spl times/2.5 Gbit/s) transmission is confirmed in an in-line amplifier configuration.

We demonstrate 40 Gbit/s RZ signal transmission over 240 km conventional single mode fiber by utilizing a time-division alternating polarization format, and a dispersion compensation fiber, a polarization independent receiver without an additional polarizer. Alternating polarization format is compared to single polarization format in 200 km SMF transmission.

The effect of Saiko-ka-ryukotsu-borei-to (SRBT) on the stress-induced increase of monoamines in brain regions was investigated in three mouse emotional stress models. Dopamine (DA) and 3,4-dihydroxy-phenyl acetic acid (DOPAC) contents were elevated significantly by electric shock stress, psychological stress and conditioned fear stress in thalamus, hypothalamus and amygdala. The DA and DOPAC levels were decreased by preadministration of SRBT (600 mg/kg, p.o.) in the last two models, but were not altered in electric shock stress. Therefore, this compound seems to be effective in stress involving emotional factors. These results indicate that SRBT affects the brain monoamine neurons leading to psychological change in mice.

The authors demonstrate 40 Gbit/s RZ signal transmission over a 240 km conventional singlemode fibre, using a time-division alternating polarisation format, a dispersion compensation fibre, and a polarisation independent receiver without an additional polariser. Alternating polarisation is compared to single polarisation for 200 km SMF transmission.

A 3 dB gain bandwidth of 75 nm (1531-1606 nm) is realised in a novel configuration of a two-stage erbium-doped fluoride fibre amplifier with a discrete fibre Raman amplifier. Error-free operation in an in-line amplifier configuration is also confirmed through a WDM (2.5 Gbit/s/spl times/9 channel) transmission experiment.

A high-gain (33 dB) and wideband (over 40 nm) 1.65 µm fibre Raman amplifier is realised using a novel pump light source. The light source emits intense amplified spontaneous emission light with a tunable wavelength (1540–1563 nm) and broad linewidth.

3 dB bandwidths of 52 nm (1556 – 1608 nm) for a silicate erbium-doped fibre amplifier (EDFA) and 50 nm (1554 – 1604 nm) for a fluoride EDFA have been obtained by a novel scheme with two-stage erbium-doped fibres and an intermediate equaliser. Low noise figures and high pump efficiencies of the EDFAs have been confirmed.

The successful two-channel WDM transmission of optically multiplexed 40 Gbit/s RZ signals with properly managed fibre dispersion is demonstrated. The dispersion dependence of the signal-to-noise-ratio for each signal channel is measured and it is found that the optimum total dispersion value, including dispersion compensation fibres, is not zero but is anomalous, which is slightly smaller than the value predicted by the soliton condition with uniform dispersion.

The widest, seamless, 76 nm (1531–1607 nm) 3 dB gain-band bidirectional amplifier is realised by combining an erbium-doped fluoride fibre amplifier (1531–1562 nm) and a gain-flattened erbium-doped silicate fibre amplifier (1562–1607 nm) in a novel configuration of gain-band separation between upstream and downstream signals. Bidirectional 10-channel WDM transmission at 2.5 Gbit/s over a 250 km conventional singlemode fibre is successfully demonstrated using our amplifiers as two bidirectional repeaters.

A 3 dB gain-reduction bandwidth up to 65 nm (1549-1614 nm) is achieved using a two-stage erbium-doped fibre amplifier, together with an intermediate equaliser and Raman amplification in the transmission fibre.

Ballooned neurons are histological features of several neurodegenerative diseases of the central nervous system. We describe the immunocytochemical staining of ballooned neurons in Pick's disease, unclassified dementia, corticonigral degeneration, pigment-spheroid degeneration and Alzheimer's disease. In all of these conditions the ballooned neurons contain phosphorylated epitopes recognized by monoclonal antibodies to neurofilaments, but not epitopes unique to Alzheimer neurofibrillary tangles and Pick bodies. The morphological features and immunohistochemical properties of ballooned neurons in these disorders bear resemblance to swollen neurons produced by neurotoxins that impair axoplasmic transport of neurofilaments. This finding, by analogy, suggests that impaired axoplasmic transport of neurofilaments may be a common mechanism in various dementing neurodegenerative diseases.

A method for reactive power planning is presented that it finds an optimal solution for both allocation and operation planning in large systems using linear programming (LP). The method utilizes calculated linear sensitivities including active power and voltage phase angle in the formulation. Although the overall method includes these relations, the number of constraints and variables are not augmented in its first procedure, APPROACH-1. Its second procedure, APPROACH-2, overcomes numerical problems caused by a dense constraint matrix. This is achieved by retaining untouched sparse sensitivities in the constraint matrix and by eliminating any calculations related to the inverse matrix. The results of applying this method to a practical 224-bus system and the IEEE-30 bus system verify its robustness and fast convergence. >

An extremely large 3-dB gain-bandwidth of 75 nm (1531-1606 nm) is achieved with a partially gain-flattened erbium-doped fluoride fiber amplifier and a distributed Raman amplifier. The Raman amplifier consists of a 85-km dispersion-shifted fiber (transmission fiber) and a practical 1505-nm Fabry-Perot laser diode pump. 9/spl times/2.5 Gb/s wavelength-division-multiplexing (WDM) transmission is successfully demonstrated using two 75-nm gain-band amplifiers as in-line and preamplifiers.