oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Search Results: 1 - 10 of 709 matches for " Soichi Maruyama "
All listed articles are free for downloading (OA Articles)
Page 1 /709
Display every page Item
The Relation among the Solar Activity, the Total Ozone, QBO, NAO, and ENSO by Wavelet-Based Multifractal Analysis  [PDF]
Fumio Maruyama
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.66109
Abstract: There is an increasing interest in the relation between the solar activity and climate change. As for the solar activity, a fractal property of the sunspot number was studied by many works. In general, a fractal property was observed in the time series of dynamics of complex systems. The purposes of this study are to investigate the relations among the solar activity, total ozone, Quasi-Biennial Oscillation (QBO), the North Atlantic Oscillation (NAO), and El Ni?o-Southern Oscillation (ENSO) from a view of multi-fractality. To detect the changes of multifractality, we examined the multifractal analysis on the time series of the solar 10.7-cm radio flux (F10.7 flux), total ozone, QBO, NAO, and Ni?o3.4 indices. During the period 1950 and 2010, for the F10.7 flux and QBO index, the matching in monofractality or multifractality is observed and the increase and decrease of multifractality is similar; that is the change of multifractality is similar. In the same way, it is very similar, during the period 1985 and 2010, for the QBO and the total ozone, and during the period 1950 and 2010, for the QBO, and NAO and for the QBO, and Ni?o3.4. Compared to Ni?o3.4, the multifractality of NAO and QBO was strong and it turns out that they are undergoing unstable change.
Relationship between the Atmospheric CO2 and Climate Indices by Wavelet-Based Multifractal Analysis  [PDF]
Fumio Maruyama
Journal of Geoscience and Environment Protection (GEP) , 2019, DOI: 10.4236/gep.2019.71004
Abstract: Atmospheric concentrations of greenhouse gases are rising, leading to a positive radiative forcing of climate and an expected warming of surface temperatures. In general, fractal properties may be observed in the time series of the dynamics of complex systems. To study the relation between the atmospheric CO2 concentration and the climate indices, we investigated the change of fractal behavior of the CO2, the carbon isotope ratio (δ13C) of atmospheric CO2, the El Ni?o-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the North Atlantic Oscillation (NAO) indices using the multifractal analysis. When the atmospheric CO2 growth rate was large, the multifractality of CO2, δ13C in CO2, ENSO, and NAO was large and the changes were large from the change of fractality. The changes of CO2 and ENSO were closely related and the influence of the CO2 on the ENSO was strong from the change in fractality and wavelet coherence. When the El Ni?o occurred, the CO2 growth rate was large. The CO2 related to PDO, NAO, and global temperature from the change in fractality and wavelet coherence. Especially, the changes of CO2 and global temperature were closely related. When the global warming hiatus occurred, the multifractality of the global temperature was weaker than that of CO2 and the change of the global temperature was stable. These findings will contribute to the research of the relation between the atmospheric CO2 and climate change.
Relationship between the Sunspot Number and Solar Polar Field by Wavelet-Based Multifractal Analysis  [PDF]
Fumio Maruyama
Journal of Applied Mathematics and Physics (JAMP) , 2019, DOI: 10.4236/jamp.2019.75070
Abstract:
There is increasing interest in finding the relation between the sunspot number (SSN) and solar polar field. In general, fractal properties may be observed in the time series of the dynamics of complex systems, such as solar activity and climate. This study investigated the relations between the SSN and solar polar field by performing a multifractal analysis. To investigate the change in multifractality, we applied a wavelet transform to time series. When the SSN was maximum and minimum, the SSN showed monofractality or weak multifractality. The solar polar field showed weak multifractality when that was maximum and minimum. When the SSN became maximum, the fractality of the SSN changed from multifractality to monofractality. The multifractality of SSN became large before two years of SSN maximum, then that of the solar polar field became large and changed largely. It was found that the change in SSN triggered the change in the solar polar field. Hence, the SSN and solar polar field were closely correlated from the view point of fractals. When the maximum solar polar field before the maximum SSN was larger, the maximum SSN of the next cycle was larger. The formation of the magnetic field of the sunspots was correlated with the solar polar field.
Candidatus Bartonella merieuxii, a Potential New Zoonotic Bartonella Species in Canids from Iraq
Bruno B. Chomel ,Audrey C. McMillan-Cole,Rickie W. Kasten,Matthew J. Stuckey,Shingo Sato,Soichi Maruyama,Pedro P. V. P. Diniz,Edward B. Breitschwerdt
PLOS Neglected Tropical Diseases , 2012, DOI: 10.1371/journal.pntd.0001843
Abstract: Bartonellae are emerging vector-borne pathogens infecting erythrocytes and endothelial cells of various domestic and wild mammals. Blood samples were collected from domestic and wild canids in Iraq under the United States Army zoonotic disease surveillance program. Serology was performed using an indirect immunofluorescent antibody test for B. henselae, B. clarridgeiae, B. vinsonii subsp. berkhoffii and B. bovis. Overall seroprevalence was 47.4% in dogs (n = 97), 40.4% in jackals (n = 57) and 12.8% in red foxes (n = 39). Bartonella species DNA was amplified from whole blood and representative strains were sequenced. DNA of a new Bartonella species similar to but distinct from B. bovis, was amplified from 37.1% of the dogs and 12.3% of the jackals. B. vinsonii subsp. berkhoffii was also amplified from one jackal and no Bartonella DNA was amplified from foxes. Adjusting for age, the odds of dogs being Bartonella PCR positive were 11.94 times higher than for wild canids (95% CI: 4.55–31.35), suggesting their role as reservoir for this new Bartonella species. This study reports on the prevalence of Bartonella species in domestic and wild canids of Iraq and provides the first detection of Bartonella in jackals. We propose Candidatus Bartonella merieuxii for this new Bartonella species. Most of the Bartonella species identified in sick dogs are also pathogenic for humans. Therefore, seroprevalence in Iraqi dog owners and bacteremia in Iraqi people with unexplained fever or culture negative endocarditis requires further investigation as well as in United States military personnel who were stationed in Iraq. Finally, it will also be essential to test any dog brought back from Iraq to the USA for presence of Bartonella bacteremia to prevent any accidental introduction of a new Bartonella species to the New World.
Parallel Evolution of a Type IV Secretion System in Radiating Lineages of the Host-Restricted Bacterial Pathogen Bartonella
Philipp Engel,Walter Salzburger,Marius Liesch,Chao-Chin Chang,Soichi Maruyama,Christa Lanz,Alexandra Calteau,Aurélie Lajus,Claudine Médigue,Stephan C. Schuster,Christoph Dehio
PLOS Genetics , 2011, DOI: 10.1371/journal.pgen.1001296
Abstract: Adaptive radiation is the rapid origination of multiple species from a single ancestor as the result of concurrent adaptation to disparate environments. This fundamental evolutionary process is considered to be responsible for the genesis of a great portion of the diversity of life. Bacteria have evolved enormous biological diversity by exploiting an exceptional range of environments, yet diversification of bacteria via adaptive radiation has been documented in a few cases only and the underlying molecular mechanisms are largely unknown. Here we show a compelling example of adaptive radiation in pathogenic bacteria and reveal their genetic basis. Our evolutionary genomic analyses of the α-proteobacterial genus Bartonella uncover two parallel adaptive radiations within these host-restricted mammalian pathogens. We identify a horizontally-acquired protein secretion system, which has evolved to target specific bacterial effector proteins into host cells as the evolutionary key innovation triggering these parallel adaptive radiations. We show that the functional versatility and adaptive potential of the VirB type IV secretion system (T4SS), and thereby translocated Bartonella effector proteins (Beps), evolved in parallel in the two lineages prior to their radiations. Independent chromosomal fixation of the virB operon and consecutive rounds of lineage-specific bep gene duplications followed by their functional diversification characterize these parallel evolutionary trajectories. Whereas most Beps maintained their ancestral domain constitution, strikingly, a novel type of effector protein emerged convergently in both lineages. This resulted in similar arrays of host cell-targeted effector proteins in the two lineages of Bartonella as the basis of their independent radiation. The parallel molecular evolution of the VirB/Bep system displays a striking example of a key innovation involved in independent adaptive processes and the emergence of bacterial pathogens. Furthermore, our study highlights the remarkable evolvability of T4SSs and their effector proteins, explaining their broad application in bacterial interactions with the environment.
Global Distribution of Bartonella Infections in Domestic Bovine and Characterization of Bartonella bovis Strains Using Multi-Locus Sequence Typing
Ying Bai, Lile Malania, Danilo Alvarez Castillo, David Moran, Sumalee Boonmar, Aran Chanlun, Fanan Suksawat, Soichi Maruyama, Darryn Knobel, Michael Kosoy
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0080894
Abstract: Bartonella bovis is commonly detected in cattle. One B. bovis strain was recently isolated from a cow with endocarditis in the USA, suggesting its role as an animal pathogen. In the present study, we investigated bartonella infections in 893 cattle from five countries (Kenya, Thailand, Japan, Georgia, and Guatemala) and 103 water buffaloes from Thailand to compare the prevalence of the infection among different regions and different bovid hosts. We developed a multi-locus sequence typing (MLST) scheme based on nine loci (16S rRNA, gltA, ftsZ, groEL, nuoG, ribC, rpoB, ssrA, and ITS) to compare genetic divergence of B. bovis strains, including 26 representatives from the present study and two previously described reference strains (one from French cows and another from a cow with endocarditis in the USA). Bartonella bacteria were cultured in 6.8% (7/103) of water buffaloes from Thailand; all were B. bovis. The prevalence of bartonella infections in cattle varied tremendously across the investigated regions. In Japan, Kenya, and the Mestia district of Georgia, cattle were free from the infection; in Thailand, Guatemala, and the Dusheti and Marneuli districts of Georgia, cattle were infected with prevalences of 10–90%. The Bartonella isolates from cattle belonged to three species: B. bovis (n=165), B. chomelii (n=9), and B. schoenbuchensis (n=1), with the latter two species found in Georgia only. MLST analysis suggested genetic variations among the 28 analyzed B. bovis strains, which fall into 3 lineages (I, II, and III). Lineages I and II were found in cattle while lineage III was restricted to water buffaloes. The majority of strains (17/28), together with the strain causing endocarditis in a cow in the USA, belonged to lineage I. Further investigations are needed to determine whether B. bovis causes disease in bovids.
A new construction of the real numbers by alternating series
Soichi Ikeda
Mathematics , 2012,
Abstract: We put forward a new method of constructing the complete ordered field of real numbers from the ordered field of rational numbers. Our method is a generalization of that of A. Knopfmacher and J. Knopfmacher. Our result implies that there exist infinitely many ways of constructing the complete ordered field of real numbers. As an application of our results, we prove the irrationality of certain numbers.
$(q,t)$-deformations of multivariate hook product formulae
Soichi Okada
Mathematics , 2009,
Abstract: We generalize multivariate hook product formulae for $P$-partitions. We use Macdonald symmetric functions to prove a $(q,t)$-deformation of Gansner's hook product formula for the generating functions of reverse (shifted) plane partitions. (The unshifted case has also been proved by Adachi.) For a $d$-complete poset, we present a conjectural $(q,t)$-deformation of Peterson--Proctor's hook product formula.
Enumeration of Symmetry Classes of Alternating Sign Matrices and Characters of Classical Groups
Soichi Okada
Mathematics , 2004,
Abstract: An alternating sign matrix is a square matrix with entries 1, 0 and -1 such that the sum of the entries in each row and each column is equal to 1 and the nonzero entries alternate in sign along each row and each column. To some of the symmetry classes of alternating sign matrices and their variations, G. Kuperberg associate square ice models with appropriate boundary conditions, and give determinanat and Pfaffian formulae for the partition functions. In this paper, we utilize several determinant and Pfaffian identities to evaluate Kuperberg's determinants and Pfaffians, and express the round partition functions in terms of irreducible characters of classical groups. In particular, we settle a conjecture on the number of vertically and horizontally symmetric alternating sign matrices (VHSASMs).
An elliptic generalization of Schur's Pfaffian identity
Soichi Okada
Mathematics , 2004,
Abstract: We present a Pfaffian identity involving elliptic functions, whose rational limit gives a generalization of Schur's Pfaffian identity for Pf ((x_j - x_i)/(x_j + x_i)). This identity is regarded as a Pfaffian counterpart of Frobenius identity, which is an elliptic generalization of Cauchy's determinant identity for det (1/ (x_i + x_j)).
Page 1 /709
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.