169 research outputs found
Cellular Polyamine Catalogues of the Five Classes of the PhylumProteobacteria: Distributions of Homospermidine within the ClassAlphaproteobacteria, Hydroxyputrescine within the ClassBetaproteobacteria, Norspermidine within the ClassGammaproteobacteria, and Spermine within the ClassesDeltaproteobacteria and Epsilonproteobacteria
Cellular polyamines extracted from reclassified or newly validated 47
alphaproteobacteria, 46 betaproteobacteria, 96 gammaproteobacteria, 12 deltaproteobacteria
and 10 epsilonproteobacteria were analyzed by high-performance liquid chromatography.
Homospermidine was widely distributed within the class Alphaproteobacteria, however,
homospermidine-dominant type, spermidine-dominant type and homospermidine/spermidinedominant
type were found and the three triamine profiles were genus-specific. The all genera
belonging to the class Betaproteobacteria, ubiquitously contained putrescine and 2-
hydroxyputrescine. Triamines were absent in almost betaproteobacteria. Many genera,
including psychrophilic species, of the class Gammaproteobacteria, contained putrescine and
spermidine as the major polyaminenes. Diaminopropane and norspermidine were selectively
distributed in several genera of the class Gammaproteobacteria. Spermidine was the major
polyamine in the classes Deltaproteobacteria and Epsilonproteobacteria. Spermine was found
in some thermophiles within Betaproteobacteria, Deltaproteobacteria and
Epsilonproteobacteria, suggesting that the occurrence of spermine correlate to their
thermophily. Additional these polyamine catalogues serve for the classification of the phylum
Proteobacteria, as a chemotaxonomic marker
Optimization of quantum noise in space gravitational-wave antenna DECIGO with optical-spring quantum locking considering mixture of vacuum fluctuations in homodyne detection
Quantum locking using optical spring and homodyne detection has been devised
to reduce quantum noise that limits the sensitivity of DECIGO, a space-based
gravitational wave antenna in the frequency band around 0.1 Hz for detection of
primordial gravitational waves. The reduction in the upper limit of energy
density from to
, as inferred from recent observations, necessitates
improved sensitivity in DECIGO to meet its primary science goals. To accurately
evaluate the effectiveness of this method, this paper considers a detection
mechanism that takes into account the influence of vacuum fluctuations on
homodyne detection. In addition, an advanced signal processing method is
devised to efficiently utilize signals from each photodetector, and design
parameters for this configuration are optimized for the quantum noise. Our
results show that this method is effective in reducing quantum noise, despite
the detrimental impact of vacuum fluctuations on its sensitivity.Comment: 12 pages, 5 figure
Discovery of a gene cluster for the biosynthesis of novel cyclic peptide compound, KK-1, in Curvularia clavata
KK-1, a cyclic depsipeptide with 10 residues produced by a filamentous fungus Curvularia clavata BAUA-2787, is a promising pesticide active compound with high activity against many plant pathogens, especially Botrytis cinerea. As a first step toward the future mass production of KK-1 through synthetic biological approaches, we aimed to identify the genes responsible for the KK-1 biosynthesis. To achieve this, we conducted whole genome sequencing and transcriptome analysis of C. clavata BAUA-2787 to predict the KK-1 biosynthetic gene cluster. We then generated the overexpression and deletion mutants for each cluster gene using our originally developed transformation system for this fungus, and analyzed the KK-1 production and the cluster gene expression levels to confirm their involvement in KK-1 biosynthesis. As a result of these, a region of approximately 71 kb was found, containing 10 open reading frames, which were co-induced during KK-1 production, as a biosynthetic gene cluster. These include kk1B, which encodes nonribosomal peptide synthetase with a domain structure that is consistent with the structural features of KK-1, and kk1F, which encodes a transcription factor. The overexpression of kk1F increased the expression of the entire cluster genes and, consequently, improved KK-1 production, whereas its deletion decreased the expression of the entire cluster genes and almost eliminated KK-1 production, demonstrating that the protein encoded by kk1F regulates the expressions of the other nine cluster genes cooperatively as the pathway-specific transcription factor. Furthermore, the deletion of each cluster gene caused a reduction in KK-1 productivity, indicating that each gene is involved in KK-1 production. The genes kk1A, kk1D, kk1H, and kk1I, which showed a significant decrease in KK-1 productivity due to deletion, were presumed to be directly involved in KK-1 structure formation, including the biosynthesis of the constituent residues. kk1C, kk1E, kk1G, and kk1J, which maintained a certain level of KK-1 productivity despite deletion, were possibly involved in promoting or assisting KK-1 production, such as extracellular transportation and the removal of aberrant units incorporated into the peptide chain
Nonalcoholic fatty liver disease in Japanese junior high school students: its prevalence and relationship to lifestyle habits
The original publication is available at www.springerlink.comDespite the increase in nonalcoholic fatty liver disease (NAFLD) in Japanese adults, its prevalence in adolescents remains unclear. This prompted us to evaluate the incidence and clinical characteristics of NAFLD among junior high school students. A population-based cross-sectional study was conducted among students in a single junior high school in Nagano prefecture. Serum alanine aminotransferase (ALT) and gamma-glutamyltransferase (gamma GT) measurements and abdominal ultrasonography were performed in 249 and 288 students in 2004 and 2007, respectively. In the latter survey, student lifestyle habits were also assessed, using questionnaires. The prevalence of NAFLD was 4.4% and 4.5% in 2004 and 2007, respectively, which was lower than that of obesity (10.0% and 5.9%). Body mass index and ALT and gamma GT levels increased significantly with hepatic steatosis severity. Multivariate logistic regression analysis demonstrated that the presence of obesity and an ALT level of 30 U/L or more were independent predictors of NAFLD (odds ratio 16.9, P < 0.001 and odds ratio 16.6, P = 0.001, respectively). The ratios of students commuting to and from school by car and not doing sports outside of school were higher in NAFLD students compared with non-NAFLD ones. Such tendencies were observed independently of the presence of obesity. Additionally, one obese student with severe steatosis and liver dysfunction was diagnosed as having nonalcoholic steatohepatitis (NASH). Approximately 4% of junior high school students had NAFLD that was primarily associated with obesity and reduced daily physical activity. Serum ALT measurement during school check-ups is recommended for the early detection of young adolescent NAFLD/NASH.ArticleJOURNAL OF GASTROENTEROLOGY. 45(6):666-672 (2010)journal articl
Serum Fragmented Cytokeratin 18 Levels Reflect the Histologic Activity Score of Nonalcoholic Fatty Liver Disease More Accurately Than Serum Alanine Aminotransferase Levels
Background and Goals: Reliable noninvasive biomarkers to assess the histologic activity of nonalcoholic fatty liver disease (NAFLD) have not been established. As the frequency of Mallory bodies is known to be closely associated with the disease severity, we hypothesized that serum levels of Mallory body-related proteins were correlated with NAFLD histologic activity and evaluated this possibility. Study: Serum levels of total and fragmented cytokeratin (CK) 18, heat shock protein (Hsp) 70, Hsp90 alpha, ubiquitin + 1, and p38 alpha at the time of liver biopsy were measured in 118 NAFLD patients and their association with histologic findings and NAFLD histologic activity score (NAS) was investigated. Results: Serum levels of both forms of CK18 and Hsp90 alpha were markedly higher in patients having nonalcoholic steatohepatitis (NASH) compared with non-NASH ones. Both forms of CK18 significantly correlated with degree of steatosis, lobular inflammation, and ballooning, and showed stronger positive correlations with NAS than serum aspartate and alanine aminotransferase (AST and ALT). Multiple regression analysis further revealed that fragmented CK18 and AST were effective predictors of NAS, with the former being the more definitive of the two (P < 0.001 vs. 0.005). In 20 NAFLD patients who received a follow-up biopsy, changes in fragmented CK18 levels, but not AST or ALT levels, closely paralleled those in NAS. Conclusions: These results establish the usefulness of fragmented CK18 measurement for assessing and monitoring the histologic activity of NAFLD.ArticleJOURNAL OF CLINICAL GASTROENTEROLOGY. 44(6):440-447 (2010)journal articl
First-step experiment in developing optical-spring quantum locking for DECIGO: sensitivity optimization for simulated quantum noise by completing the square
DECi-hertz Interferometer Gravitational Wave Observatory (DECIGO) is a future
mission for a space-borne laser interferometer. DECIGO has 1,000-km-long arm
cavities mainly to detect the primordial gravitational waves (PGW) at lower
frequencies around 0.1 Hz. Observations in the electromagnetic spectrum have
lowered the bounds on the upper limit of PGW energy density (). As a result, DECIGO's target sensitivity, which
is mainly limited by quantum noise, needs further improvement. To maximize the
feasibility of detection while constrained by DECIGO's large diffraction loss,
a quantum locking technique with an optical spring was theoretically proposed
to improve the signal-to-noise ratio of the PGW. In this paper, we
experimentally verify one key element of the optical-spring quantum locking:
sensitivity optimization by completing the square of multiple detector outputs.
This experiment is operated on a simplified tabletop optical setup with
classical noise simulating quantum noise. We succeed in getting the best of the
sensitivities with two different laser powers by the square completion method.Comment: 10 pages, 14 figure
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