Cut loci and conjugate loci on Liouville surfaces

In the earlier paper (Itoh and Kiyohara, Manuscr Math 114:247–264, 2004), we showed that the cut locus of a general point on two-dimensional ellipsoid is a segment of a curvature line and proved "Jacobi’s last geometric statement" on the singularities of the conjugate locus. In the present paper,we showthat a wider class of Liouville surfaces possess such simple cut loci and conjugate loci. The results include the determination of cut loci and the set of poles on two-sheeted hyperboloids and elliptic paraboloids

Fourier-transform spectral imaging: retrieval of source information from three-dimensional spatial coherence

A method is described for efficiently obtaining the comprehensive information of a polychromatic radiator. Under certain conditions both the spatial and spectral details of the radiative object can be recovered simultaneously from the three-dimensional spatial coherence function in the diffraction region. The recovery of object information is based on a Fourier-transform relationship derived from the basic formula [E. Wolf and W. H. Carter, J. Opt. Soc. Am. 68, 953-964 (1978)] describing the field correlation function in terms of the source correlation function. A new type of interferometer is proposed for the efficient collection of the spatial coherence data. Experimental results of the spectral-image recovery are also presented

In vivo manipulation of fluorescently labeled organelles in living cells by multiphoton excitation

Wataru Watanabe, Sachhiro Matsunaga, Tsunehito Higashi, Kiichi Fukui, and Kazuyoshi Itoh "In vivo manipulation of fluorescently labeled organelles in living cells by multiphoton excitation," Journal of Biomedical Optics 13(3), 031213 (1 May 2008). https://doi.org/10.1117/1.293940

Analysis and experimental assessment of the sensitivity of stimulated Raman scattering microscopy

Ozeki Y., Dake F., Kajiyama S., et al. Analysis and experimental assessment of the sensitivity of stimulated Raman scattering microscopy. Optics Express, 17, 5, 3651. https://doi.org/10.1364/OE.17.003651

Femtosecond laser manipulation of subcellular organelles in living cells

European Conferences on Biomedical Optics 2005, 2005, Munich, GermanyWataru Watanabe, Tomoko Shimada, Kazuyoshi Itoh, Sachihiro Matsunaga, Kiichi Fukui, "Femtosecond laser manipulation of subcellular organelles in living cells," Proc. SPIE 5863, Therapeutic Laser Applications and Laser-Tissue Interactions II, 58630B (26 August 2005); https://doi.org/10.1117/12.633079

Functional analysis of mucin-type core 1 glycan in Drosophila neuromuscular junction

T antigen (Galβ1-3GalNAcα1-Ser/Thr), which is one of mucin-type O-glycans, is synthesized by Drosophila core 1 β1,3-galactosyltransferase 1 (dC1GalT1). Glucuronylated T antigen (GlcAβ1-3Galβ1-3GalNAcα1-Ser/Thr), in which glucuronic acid is added in a β1,3-linkage to galactose of T antigen, has been identified in Drosophila. However, the physiological function of this glycan structure has not yet been clarified. In this study, to unravel the function of glucuronylated T antigen in Drosophila neuromuscular junctions (NMJs), we analyzed the mutant phenotypes of dC1GalT1 and Drosophila glucuronyltransferase-P (dGlcAT-P) that predominantly synthesizes glucuronylated T antigen.We firstly analyzed the phenotypes of dC1GalT1 mutants. The T antigen expression on the muscle surface and NMJs was decreased in dC1GalT1 mutant larvae. We found that the dC1GalT1 mutants showed the partial loss of basement membrane (BM) component and mislocalization of NMJ boutons at the muscle 6/7 boundary. Ultrastructural observation revealed that those mislocalized boutons connected the muscles 6 and 7. Moreover, dC1GalT1 mutants exhibited reduced number of NMJ branches. In Drosophila, three glucuronyltransferases (dGlcAT-I, dGlcAT-S, and dGlcAT-P) have been reported. By measurement of enzymatic activity and MS analysis of the enzymatic products, we found that dGlcAT-P is predominant glucuronyltransferase that produces glucuronylated T antigen. Then, we generated dGlcAT-P mutants by using CRISPR-Cas9 method. In dGlcAT-P mutant larvae, glucuronylated T antigen expression was reduced on the muscle surface and at NMJs. As is the case with the dC1GalT1 mutants, dGlcAT-P mutants showed the three phenotypes, i.e., the partial loss of BM component, mislocalization of NMJ boutons, reduced number of NMJ branches. Furthermore, ultrastructural analysis of muscle 6/7 boundary revealed that BMs underneath the mislocalized boutons were severely deformed in dGlcAT-P mutants. We found that there was a genetic interaction between dC1GalT1 and dGlcAT-P because double heterozygous mutants of dC1GalT1 and dGlcAT-P exhibited the BM and NMJ phenotypes.　Finally, ultrastructural analysis of NMJ boutons showed the shorter length of postsynaptic density (PSD) in both dC1GalT1 and dGlcAT-P mutants.Taken together, these data demonstrated that glucuronylated T antigen synthesized sequentially by dC1GalT1 and dGlcAT-P is required for the normal formation of BMs, precise localization of NMJ boutons, arborization of NMJs, and organization of PSDs.創価大

Highly sensitive spectral interferometric fourwave mixing microscopy near the shot noise limit and its combination with two-photon excited fluorescence microscopy

Isobe K., Ozeki Y., Kawasumi T., et al. Highly sensitive spectral interferometric fourwave mixing microscopy near the shot noise limit and its combination with two-photon excited fluorescence microscopy. Optics Express, 14, 23, 11204. https://doi.org/10.1364/OE.14.011204

Nanosurgery of sub-cellular organelles in living cells using a femtosecond laser oscillator

Lasers and Applications in Science and Engineering, 2006, San Jose, California, United StatesWataru Watanabe, Tomoko Shimada, Sachihiro Matsunaga, Hiroshi Ishii, Tsunehito Higashi, Kiichi Fukui, Kazuyoshi Itoh, "Nanosurgery of sub-cellular organelles in living cells using a femtosecond laser oscillator," Proc. SPIE 6108, Commercial and Biomedical Applications of Ultrafast Lasers VI, 610804 (28 February 2006); https://doi.org/10.1117/12.645474