The realization of all-optical switching, modulating and computing devices is an important goal in modern optical technology. Nonlinear optical materials with large third-order nonlinear susceptibilities (chi(3)) are indispensable for such devices, because the magnitude of this quantity dominates the device performance. A key strategy in the development of new materials with large nonlinear susceptibilities is the exploration of quasi-one-dimensional systems, or 'quantum wires'--the quantum confinement of electron-hole motion in one-dimensional space can enhance chi(3). Two types of chemically synthesized quantum wires have been extensively studied: the band insulators of silicon polymers, and Peierls insulators of pi-conjugated polymers and platinum halides. In these systems, chi(3) values of 10(-12) to 10(-7) e.s.u. (electrostatic system of units) have been reported. Here we demonstrate an anomalous enhancement of the third-order nonlinear susceptibility in a different category of quantum wires: one-dimensional Mott insulators of 3d transition-metal oxides and halides. By analysing the electroreflectance spectra of these compounds, we measure chi(3) values in the range 10(-8) to 10(-5) e.s.u. The anomalous enhancement results from a large dipole moment between the lowest two excited states of these systems.

Background-We recently reported that cardiomyocytes could be differentiated from bone marrow mesenchymal stem cells in vitro by 5-azacytidine treatment. In native cardiomyocytes, adrenergic and muscarinic receptors play crucial roles in mediating heart rate, conduction velocity, contractility, and cardiac hypertrophy. We investigated whether these receptors are expressed in differentiated CMG cells, and if so, whether they have downstream signaling systems. Methods and Results-Reverse transcription-polymerase chain reaction revealed that CMG cells had already expressed ␣ 1A -, ␣ 1B -, and ␣ 1D -adrenergic receptor mRNA before 5-azacytidine treatment, whereas expression of ␤ 1 -, ␤ 2 -adrenergic and M 1 -, M 2 -muscarinic receptors was first detected at 1 day. Phenylephrine dose-dependently induced phosphorylation of ERK1/2, which was completely inhibited by prazosin, and significantly increased cell size. Isoproterenol augmented cAMP by 38-fold, which was fully inhibited by propranolol. Isoproterenol (10 Ϫ7 mol/L) increased the spontaneous beating rate by 47.6% (basal, 127Ϯ16 bpm), and propranolol and CGP20712A (␤ 1 -selective blocker) reduced it by 79.0% and 71.0%, respectively, whereas ICI118551 (␤ 2 -selective blocker) induced slight reduction. Cell motion, percent shortening, and contractile velocity were increased by 37.5%, 26.9%, and 50.6%, respectively, in response to isoproterenol. Phenylephrine and isoproterenol augmented ANP and BNP gene expressions. Carbachol increased IP 3 by 32-fold, which was markedly inhibited by atropine as well as AFDX116 (M 2 -selective blocker) measured by radioimmunoassay. Conclusions-These

Summary1 Forest canopy gap and community dynamics were studied in a 4-ha permanent plot of an old-growth evergreen broad-leaved forest dominated by Castanopsis cuspidata var. sieboldii and Distylium racemosum in the Tatera Forest Reserve, Tsushima Islands, south-western Japan. The forest was affected by a powerful typhoon in 1987 and was monitored from 1990 to 1997. , and the rates of loss and gain in basal area were 0.95% year -1 and 0.83% year -1 . 4 The mortality of stems was size-dependent, with those in middle size classes having the lowest rates. Mortality of stems was lower in canopy and higher in the understorey, while the proportion of stems killed by disturbances increased with height. 5 Stems that died during the 7 years were predominantly located in newly created gaps, whereas stems were recruited into both established and new gaps. Deciduous broadleaved species were largely restricted to gaps that remained open throughout the study. 6 Both composition and structure of the forest changed in response to disturbancerelated effects on canopy dynamics.

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