Low-frequency discrete breathers in long-range systems without on-site potential

We propose a new mechanism of long-range coupling to excite low-frequency discrete breathers without the on-site potential. This mechanism is universal in long-range systems irrespective of the spatial boundary conditions, of topology of the inner degree of freedom, and of precise forms of the coupling functions. The limit of large population is theoretically discussed for the periodic boundary condition. Existence of discrete breathers is numerically demonstrated with stability analysis.Comment: 5 pages, 4 figure

Studies on thyroid func­tion Ⅱ. Effect of thyroidectomy and thyroid extract on the urinary amino acids of animals

1. &#945;-Aminoadipic acid and lysine are increased in the urine of thyroidectomized dog. 2. Pipecolic acid is increased in the urine of rat treated with thyroid extract. 3. Relation between thyroid function and lysine metabolism is discussed.</p

The Centimeter to Submillimeter Broad Band Radio Spectrum of the Central Compact Component in A Nearby Type-II Seyfert Galaxy NGC 1068

We analyze all the available Atacama Large Millimeter / submillimeter Array archival data of the nearby Type-II Seyfert galaxy NGC 1068, including new 100 GHz data with the angular resolution of 0\farcs05, which was not included in previous continuum spectral analysis. By combining with the literature data based on the Very Large Array, we investigate the broadband radio continuum spectrum of the central $\lesssim7$ pc region of NGC 1068. We found that the flux density is between $\approx$10-20 mJy at 5-700 GHz. Due to the inability of the model in previous studies to account for the newly added 100 GHz data point, we proceeded to update the models and make the necessary adjustments to the parameters. One possible interpretation of this broadband radio spectrum is a combination of emission from the jet base, the dusty torus, and the compact X-raying corona with the magnetic field strength of $\approx20$ G on scales of $\approx30$ Schwarzschild radii from the central black hole. In order to firmly identify the compact corona by omitting any other possible extended components (e.g., free-free emission from ionized gas around), high-resolution/sensitivity observations achieved by next-generation interferometers will be necessary.Comment: 10 pages, 4 figures, 3 tables, accepted for publication in PAS

Far -Infrared Study of Two-Dimensional Air-Rod Photonic Crystals : Band Gap, Uncoupled Mode and Wavevector Mismatch

Two-dimensional photonic crystals both of square and triangular lattices composed of circular air-rods with the lattice constant of 170 μm were fabricated. The photonic band structures were studied by far-infrared transmission measurements. The clear opaque regions due to the band gap and due to the non coupling between photonic mode and external wave were observed in both lattices. The uncoupled modes can not be excited by an external mode because their wave functions are anti-symmetric under the relevant mirror reflection defined on the lattice. Furthermore, some regions with very low transmittance were found, where exist only a band whose dominant plane-wave component in eigen-function has wavevector not parallel to the propagating direction of the external incident wave. These low transmittance are considered to be caused by wavevector mismatch between photonic modes and external incident waves. The observed spectra are discussed compared with the results of band structure calculated by means of a plane-wave expansion method as well as of the symmetry consideration.Article信州大学理学部紀要 31(2): 89-104(1997)departmental bulletin pape

A Simple Screening of Flower Sensitivity to Ethylene in Several Ornamental Asteraceae Species

Generally, Asteraceae flowers such as chrysanthemums and gerberas, are low ethylene-sensitive and do not exhibit petal wilting and abscission. However, previous research found that the flowers of dahlia, an Asteraceae member belonging to the tribe Coreopsideae, are ethylene-sensitive and show abscission layer development in petal-ovary boundaries. In this study, we investigated the ethylene sensitivity of 17 ornamental Asteraceae species belonging to different tribes by measuring the petal drawing resistance and vase life after 1-3 μL·L-1 ethylene exposure for 20 h. Although more than half of the tested species did not respond to ethylene, several species showed ethylene-sensitive petal wilting and abscission of fresh ray florets. Ethylene-sensitive petal wilting occurred in only two species (Calendula officinalis L. and Osteospermum L.) of the tribe Calenduleae, while ethylene-sensitive petal abscission occurred mainly in six species (Bidens ferulifolia D.C., Coreopsis lanceolata L., Cosmos atrosanguineus (Hook) Voss., Cosmos bipinnatus Cav., Cosmos sulphureus Cav. and Dahlia Cav.) of tribe Coreopsideae and one species (Helianthus annuus L.) of the tribe Heliantheae. In these species, abscission petals maintained their turgidity, and this process could be detected by measuring the petal drawing resistance of the ray florets. The reduction in petal drawing resistance, associated with abscission layer development in the petal-ovary boundaries, was observed only in these ethylene-sensitive species. The results of this study suggest that the ethylene sensitivity and petal senescing patterns in Asteraceae flowers may be associated with the phylogenetic classification at the tribe level

Effects of Deflowering and Defoliating on the Postharvest Characteristics of Individual Organs in Cut Dahlias

Cut dahlia (Dahlia Cav.) flowers have recently become popular, but their marketability has been limited due to their poor vase life. The purposes of this study were to clarify the roles of leaves and inflorescences in the senescence of cut dahlias and to discuss the sink-source relationship between vegetative organs and inflorescences. The leaf life was maintained much longer (16.7 days) than the inflorescence life (7.4 days). The inflorescence life was not affected by removal of leaves, while leaf life was prolonged (19.6 days) by removal of inflorescences. Sucrose, glucose, fructose and small quantities of myo-inositol were detected in florets, and in addition to these sugars, nystose and 1-kestose were detected in stems and leaves. Total sugar levels of the middle florets (14.5 mg·g⁻¹ FW on day 0) declined rapidly before their senescence. Total sugar levels of leaves (20.5 mg·g⁻¹ FW on day 0) and stems (19.0–22.5 mg·g⁻¹ FW on day 0) also decreased gradually during the postharvest period, but the levels decreased more slowly in deflowered cut stems. Sugar leakage from stem bases into vase water occurred during the initial few days. Removal of inflorescences increased sugar leakage significantly and promoted callus formation on the stem base. From these results, the inflorescence is considered to be a strong sink for carbohydrates, and stems and leaves serve as source organs. Heat girdling applied to the flower necks and petioles, also increased sugar concentrations of stem bases, thus resulting in higher sugar leakage and callus formation, although both heat girdling treatments shortened the leaf life. The sharp decrease in sugar levels of florets and an insufficient sugar supply are considered to be responsible for the short vase life of cut dahlias. It is suggested that these effects might be partly due to the blockage of sugar flows into petals through abscission layer development in the petal-ovary boundaries. Based on these results, we illustrate the senescing process of cut dahlia flowers in relation to sugar dynamism