Boundedness of bundle diffeomorphism groups over a circle

In this paper we study boundedness of bundle diffeomorphism groups over a circle. For a fiber bundle $\pi : M \to S^1$ with fiber $N$ and structure group $\Gamma$ and $r \in {\Bbb Z}_{\geq 0} \cup \{ \infty \}$ we distinguish an integer $k = k(\pi, r) \in {\Bbb Z}_{\geq 0}$ and construct a function $\widehat{\nu} : {\rm Diff}_\pi(M)_0 \to {\Bbb R}_k$. When $k \geq 1$, it is shown that the bundle diffeomorphism group ${\rm Diff}_\pi(M)_0$ is uniformly perfect and $clb_\pi\,{\rm Diff}^r_\pi(M)_0 \leq k+3$, if ${\rm Diff}_{\rho, c}(E)_0$ is perfect for the trivial fiber bundle $\rho : E \to {\Bbb R}$ with fiber $N$ and structure group $\Gamma$. On the other hand, when $k = 0$, it is shown that $\widehat{\nu}$ is a unbounded quasimorphism, so that ${\rm Diff}_\pi(M)_0$ is unbounded and not uniformly perfect. We also describe the integer $k$ in term of the attaching map $\phi$ for a mapping torus $\pi : M_\phi \to S^1$ and give some explicit examples of (un)bounded groups.Comment: 29 page

The first homology of the group of equivariant diffeomorphisms and its application

Let V be a representation space of a finite group G. We determine the group structure of the first homology of the equivariant diffeomorphism group of V. Then we can apply it to the calculation of the first homology of the corresponding automorphism groups of smooth orbifolds, compact Hausdorff foliations, codimension one or two compact foliations and a locally free circle action on the 3-sphere.Comment: 23page

Expression of tyrosine hydroxylase in cerebellar Purkinje cells of ataxic mutant mice:its relation to the onset and/or development of ataxia

This report describes recent studies on tyrosine hydroxylase (TH) expression in Purkinje cells of the cerebellum of ataxic mutant mice. An increased expression of TH in some Purkinje cells has been observed in two allelic groups of mutant mice, tottering and dilute. TH-positive Purkinje cells appeared preceding the onset of ataxia. Northern blot analysis revealed2.1kb of TH mRNA in the mutant cerebella, and the size was identical to that of TH transcripts in other brain regions. However, TH in Purkinje cells did not seem to participate in catecholamine biosynthesis. In vitro studies showed that cultured non-catecholaminergic neurons expressed the TH transcripts following Ca2+ influx. Therefore, abnormal TH expression in the mutant Purkinje cells may indicate neuronal dysfunction caused by misregulation of intracellular Ca2+concentrations

Residue conservation and dimer-interface analysis of olfactory receptor molecular models

Olfactory Receptors (ORs) are members of the Class A rhodopsin like G-protein coupled receptors (GPCRs) which are the initial players in the signal transduction cascade, leading to the generation of nerve impulses transmitted to the brain and resulting in the detection of odorant molecules. Despite the accumulation of thousands of olfactory receptor sequences, no crystal structures of ORs are known tο date. However, the recent availability of crystallographic models of a few GPCRs allows us to generate homology models of ORs and analyze their amino acid patterns, as there is a huge diversity in OR sequences. In this study, we have generated three-dimensional models of 100 representative ORs from Homo sapiens, Mus musculus, Drosophila melanogaster, Caenorhabditis elegans and Sacharomyces cerevisiae which were selected on the basis of a composite classification scheme and phylogenetic analysis. The crystal structure of bovine rhodopsin was used as a template and it was found that the full-length models have more than 90% of their residues in allowed regions of the Ramachandran plot. The structures were further used for analysis of conserved residues in the transmembrane and extracellular loop regions in order to identify functionally important residues. Several ORs are known to be functional as dimers and hence dimer interfaces were predicted for OR models to analyse their oligomeric functional state

Sequence and structural features of binding site residues in protein-protein complexes: comparison with protein-nucleic acid complexes

<p>Abstract</p> <p>Background</p> <p>Protein-protein interactions are important for several cellular processes. Understanding the mechanism of protein-protein recognition and predicting the binding sites in protein-protein complexes are long standing goals in molecular and computational biology.</p> <p>Methods</p> <p>We have developed an energy based approach for identifying the binding site residues in protein–protein complexes. The binding site residues have been analyzed with sequence and structure based parameters such as binding propensity, neighboring residues in the vicinity of binding sites, conservation score and conformational switching.</p> <p>Results</p> <p>We observed that the binding propensities of amino acid residues are specific for protein-protein complexes. Further, typical dipeptides and tripeptides showed high preference for binding, which is unique to protein-protein complexes. Most of the binding site residues are highly conserved among homologous sequences. Our analysis showed that 7% of residues changed their conformations upon protein-protein complex formation and it is 9.2% and 6.6% in the binding and non-binding sites, respectively. Specifically, the residues Glu, Lys, Leu and Ser changed their conformation from coil to helix/strand and from helix to coil/strand. Leu, Ser, Thr and Val prefer to change their conformation from strand to coil/helix.</p> <p>Conclusions</p> <p>The results obtained in this study will be helpful for understanding and predicting the binding sites in protein-protein complexes.</p

Ca2＋チャンネルビョウ マウス ニオケル ショウノウ ノ イジョウ ト ウンドウ シッチョウ

This review summarizes recent studies on the morphological abnormalities of cerebella in four ataxic mutant mice, i.e., tottering mouse, leaner mouse, rolling mouse Nagoya (RMN) and rocker mouse. These mutants carry mutations in the Ca2+ channel α1A subunit gene, and become useful models for human Ca2+ channelopathy such as episodic ataxia type-2 and familial hemiplegic migraine. Abnormal expression of tyrosine hydroxylase (TH) in some Purkinje cells has been observed in tottering mice, leaner mice and RMN, but not in rocker mice. However, Purkinje cells did not seem to synthesize catecholamines. Since the transcription of the TH gene is facilitated by Ca2+, TH expression in the mutant Purkinje cells indicates functional abnormality by alterations in intracellular Ca2+ concentrations. Corticotropin-releasing factor (CRF) immunoreactivity in some climbing or mossy fibers was higher in RMN than in controls. Double immunostaining for CRF and TH revealed a correspondence in the distribution of TH-positive Purkinje cells to terminal fields of CRF-positive climbing fibers in RMN. Therefore, CRF seems to alter granule and Purkinje cell functions, such as abnormal TH expression, indicating the possible expression of ataxic symptoms

Estimation of the refractive index of volcanic ash from satellite infrared sounder data

AbstractWe investigated the spectral refractive indices (RIs) of volcanic ash materials in the wavenumber range of 700–1100cm−1 using satellite infrared sounder measurements and radiative transfer calculations. The ash RIs of 10 ash clouds from eight volcanoes were evaluated (Bezymianny on 2 September 2012, Chaitén on 3 May 2008, Kelut on 14 February 2014, Kirishimayama on 27 January 2011, Kliuchevskoi on 30 June 2007 and 18 October 2013, Puyehue–Cordon Caulle on 5 June 2011, Sangeang-Api on 31 May 2014, and Sheveluch on 28 October 2010 and 18 September 2012). We elaborated on a dataset of volcanic ash measurements made by the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite. The measured brightness temperatures in the ash cloud data revealed silicate absorption features at around 10μm. By applying atmospheric profiles from results of a global data assimilation system and using ash cloud properties (ash optical depth, effective radius, and ash cloud height) as parameters for radiative transfer calculations, least squares analyses for the observed and calculated brightness temperatures were conducted using AIRS channels in the wavenumber range of 700–1100cm−1, except for the O3 absorption channels in the range of 980–1070cm−1. Using the RIs for typical volcanic rocks in the ascending order of SiO2 content, basalt, andesite, and rhyolite, a mixture of basalt and rhyolite and a mixture of andesite and rhyolite for the ash material were considered. The volume fraction of the mixture was used as a retrieval parameter and as the ash cloud parameter. Using the estimated ash cloud parameters as fixed values, and under the assumption that the RI from the estimated volume fraction had some accuracy in the wavenumber ranges of 850–980cm−1 and 1070–1100cm−1, the RI imaginary part of each eruptive ash cloud captured by AIRS was then determined from iterative calculations at wavenumbers between 750cm−1 and 980cm−1. In the wavenumber range of 850–980cm−1, the observed brightness temperatures could be approximately simulated using the reported RIs from Pollack, Toon, and Khare (1973) for andesite, basalt, and rhyolite, and their combinations. Furthermore, some estimated RIs were consistent with the reported rock types of the volcanoes, which had been previously classified by compositional analyses in the literature. Our analysis also identified weak absorptions around 750–850cm−1, which could not be reproduced by the reported RIs. These weak absorptions were likely due to Si–O and/or Al–O vibrations, which have been proposed in reports from previous laboratory experiments for some silicate glass samples. Our results suggest that the detailed RI of volcanic ash can be determined from an analysis of satellite infrared sounder data. The RI of the ash material estimated from satellite infrared sounder data can be used to improve the ash retrieval algorithms of other satellite measurements. Furthermore, an RI retrieved by sounder measurements may provide diagnostic information regarding volcanic activity from comparisons with the ash RIs from past eruptions

Stimulated raman scattering microscope with shot noise limited sensitivity using subharmonically synchronized laser pulses

Ozeki Y., Kitagawa Y., Sumimura K., et al. Stimulated raman scattering microscope with shot noise limited sensitivity using subharmonically synchronized laser pulses. Optics Express, 18, 13, 13708. https://doi.org/10.1364/OE.18.013708