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result(s) for
"Tamura, Y"
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Gas filaments of the cosmic web located around active galaxies in a protocluster
by
Kohno, K.
,
Ivison, R. J.
,
Umehata, H.
in
Active galaxies
,
Embedded structures
,
Emission analysis
2019
Cosmological simulations predict that the Universe contains a network of intergalactic gas filaments, within which galaxies form and evolve. However, the faintness of any emission from these filaments has limited tests of this prediction. We report the detection of rest-frame ultraviolet Lyman-α radiation from multiple filaments extending more than one megaparsec between galaxies within the SSA22 protocluster at a redshift of 3.1. Intense star formation and supermassive black-hole activity is occurring within the galaxies embedded in these structures, which are the likely sources of the elevated ionizing radiation powering the observed Lyman-α emission. Our observations map the gas in filamentary structures of the type thought to fuel the growth of galaxies and black holes in massive protoclusters.
Journal Article
The gravitationally unstable gas disk of a starburst galaxy 12 billion years ago
2018
Galaxies in the early Universe that are bright at submillimetre wavelengths (submillimetre-bright galaxies) are forming stars at a rate roughly 1,000 times higher than the Milky Way. A large fraction of the new stars form in the central kiloparsec of the galaxy
1
–
3
, a region that is comparable in size to the massive, quiescent galaxies found at the peak of cosmic star-formation history
4
and the cores of present-day giant elliptical galaxies. The physical and kinematic properties inside these compact starburst cores are poorly understood because probing them at relevant spatial scales requires extremely high angular resolution. Here we report observations with a linear resolution of 550 parsecs of gas and dust in an unlensed, submillimetre-bright galaxy at a redshift of
z
= 4.3, when the Universe was less than two billion years old. We resolve the spatial and kinematic structure of the molecular gas inside the heavily dust-obscured core and show that the underlying gas disk is clumpy and rotationally supported (that is, its rotation velocity is larger than the velocity dispersion). Our analysis of the molecular gas mass per unit area suggests that the starburst disk is gravitationally unstable, which implies that the self-gravity of the gas is stronger than the differential rotation of the disk and the internal pressure due to stellar-radiation feedback. As a result of the gravitational instability in the disk, the molecular gas would be consumed by star formation on a timescale of 100 million years, which is comparable to gas depletion times in merging starburst galaxies
5
.
The molecular gas in the inner kiloparsec of a submillimetre-bright galaxy is clumpy and gravitationally unstable, collapsing to form stars at a rate that will deplete the gas in about 100 million years.
Journal Article
Development of Numerical Simulation Method for Compressible Gas-Liquid Two-Phase Flows
2015
A numerical simulation method of compressible gas-liquid two-phase flow is developed for analyses of a cavitation bubble. Thermodynamic state of both phases is described with stiffened gas equation of state. Interface of two phases is captured by Level-Set method. As internal energy jump between two phases is critical for the stability of computation, total energy equation is modified so that inviscid flux of energy is smoothly connected across the interface. Detail of governing equations as well as their discretization is described followed by the result of one-dimensional simple example computation.
Journal Article
Tumor-to-tumor metastasis: lung cancer within a thymoma
2021
Tumor-to-tumor metastasis is a rare phenomenon. We present a rare case of an 83-year-old man with pulmonary squamous cell carcinoma and thymoma. Thymectomy and superior segmentectomy of the left lower lobe were successfully performed on the patient. This thymoma had a region of lung cancer. Metastasis from other tumors to thymoma is rare, and we found a report that described a pancreatic carcinoma metastasizing to thymoma. We report an extremely rare case of metastasis from lung cancer to a thymoma.
Journal Article
Characterisation of antibiotic resistance of Salmonella isolated from dog treats in Japan
by
Hasegawa, T.
,
Tamura, Y.
,
Ohshima, S.
in
Animal Feed - microbiology
,
Animals
,
beta-Lactam Resistance - genetics
2019
Dog treats might be contaminated with Salmonella. In Canada and the USA, outbreaks of human salmonellosis related to exposure to animal-derived dog treats were reported. Consequently, surveillance data on Salmonella contamination of dog treats have been gathered in many countries, but not in Japan. In the current study, we investigated whether dog treats in Japan were contaminated with Salmonella. Overall, 303 dog treats (of which 255 were domestically produced) were randomly collected and the presence of Salmonella investigated. Seven samples were positive for Salmonella enterica subsp. enterica. Among these isolates, three were identified as serovar 4,5,12:i:–; two were serovar Rissen; and two were serovar Thompson. All serovar 4,5,12:i:– and Thompson isolates were resistant to one or more drugs. Two serovar Rissen isolates were fully susceptible to all tested antimicrobial agents. All Salmonella isolates were susceptible to cefotaxime, ciprofloxacin and nalidixic acid. The gene bla
TEM was detected in two serovar 4,5,12:i:– isolates. The bla
CTX−M and bla
CMY genes were not detected in any isolates. This study demonstrated that dog treats in Japan could constitute a potential source of dog and human Salmonella infections, including multidrug-resistant Salmonella isolates.
Journal Article
Difference between “Physical Fitness Age” Based on Physical Function and Chronological Age Is Associated with Obesity, Hyperglycemia, Depressive Symptoms, and Low Serum Albumin
2022
This study aimed to (1) develop the physical fitness age, which is the biological age based on physical function, (2) evaluate the validity of the physical fitness age for the assessment of sarcopenia, and (3) examine the factors associated with the difference between physical fitness age and chronological age.
Cross-sectional study
Community-dwelling older adults and outpatients.
A formula for calculating the physical fitness age was created based on the usual walking speed, handgrip strength, one-leg standing time, and chronological age of 4,076 older adults from the pooled data of community-dwelling and outpatients using the principal component analysis. For the validation of the physical fitness age, we also used pooled data from community-dwelling older adults (n = 1929) and outpatients (n = 473). Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019 consensus. The association of D-age (the difference between physical and chronological ages) with cardiovascular risk factors, renal function, and cardiac function was examined.
The receiver operating characteristic analysis, with sarcopenia as the outcome, showed that the area under the curve (AUC) of physical fitness age was greater than that of chronological age (AUC 0.87 and 0.77, respectively, p < 0.001). Binomial logistic regression analysis revealed that the D-age was significantly associated with sarcopenia after adjustment for covariates (odds ratio 1.22, 95% confidence interval 1.19–1.26; p <0.001). In multivariate linear regression analysis with D-age as the dependent variable, D-age was independently associated with a history of diabetes mellitus (or hemoglobin A1c as a continuous variable), obesity, depression, and low serum albumin level. D-age was also correlated with estimated glomerular filtration rate derived from serum cystatin C, brain natriuretic peptide, and ankle-brachial index, reflecting some organ function and arteriosclerosis.
Compared to chronological age, physical fitness age calculated from handgrip strength, one-leg standing time, and usual walking speed was a better scale for sarcopenia. D-age, which could be a simple indicator of physical function, was associated with modifiable factors, such as poor glycemic control, obesity, depressive symptoms, and malnutrition.
Journal Article
Two γ-ray bursts from dusty regions with little molecular gas
2014
Emission spectra from the host galaxies of two γ-ray bursts reveal that the regions where the bursts occur are rich in dust but not in molecular gas, which is unexpected because γ-ray bursts are associated with the explosions of massive stars that require molecular gas as fuel.
ALMA sheds new light on dark γ-ray bursts
This study reports the first detection of carbon monoxide (CO) line emission — a tracer of molecular gas — in host galaxies of long-duration γ-ray bursts (GRBs). Such bursts are associated with the explosions of massive stars and are expected to reside in star-forming regions, but this is the first observation of a burst that places it within a molecular gas reservoir, providing the fuel for star formation. Bunyo Hatsukade
et al
. report spatially resolved ALMA (Atacama Large Millimeter/submillimeter Array) observations of CO line emission and millimetre-wavelength continuum emission in two host galaxies, at redshifts of
z
= 0.41 and
z
= 0.81. The bursts occurred in a dust-rich region where molecular gas is in short supply, and suggest that the dust obscuration may explain the apparent anomaly of 'dark' GRBs that are bright in γ- and X-ray emissions but transmit little or no visible light.
Long-duration γ-ray bursts are associated with the explosions of massive stars
1
and are accordingly expected to reside in star-forming regions with molecular gas (the fuel for star formation). Previous searches for carbon monoxide (CO), a tracer of molecular gas, in burst host galaxies did not detect any emission
2
,
3
,
4
. Molecules have been detected as absorption in the spectra of γ-ray burst afterglows, and the molecular gas is similar to the translucent or diffuse molecular clouds of the Milky Way
5
,
6
. Absorption lines probe the interstellar medium only along the line of sight, so it is not clear whether the molecular gas represents the general properties of the regions where the bursts occur. Here we report spatially resolved observations of CO line emission and millimetre-wavelength continuum emission in two galaxies hosting γ-ray bursts. The bursts happened in regions rich in dust, but not particularly rich in molecular gas. The ratio of molecular gas to dust (<9–14) is significantly lower than in star-forming regions of the Milky Way and nearby star-forming galaxies, suggesting that much of the dense gas where stars form has been dissipated by other massive stars.
Journal Article
Deshima 2.0: Rapid Redshift Surveys and Multi-line Spectroscopy of Dusty Galaxies
by
Rybak, M.
,
Kohno, K.
,
van der Werf, P.
in
Bandwidths
,
Characterization and Evaluation of Materials
,
Condensed Matter Physics
2022
We present a feasibility study for the high-redshift galaxy part of the Science Verification Campaign with the 220–440 GHz
deshima
2.0 integrated superconducting spectrometer on the ASTE telescope. The first version of the
deshima
2.0 chip has been recently manufactured and tested in the lab. Based on these realistic performance measurements, we evaluate potential target samples and prospects for detecting the [CII] and CO emission lines. The planned observations comprise two distinct, but complementary objectives: (1) acquiring spectroscopic redshifts for dusty galaxies selected in far-infrared/mm-wave surveys; (2) multi-line observations to infer physical conditions in dusty galaxies.
Journal Article
Detection of methicillin-resistant Staphylococcus pseudintermedius ST169 and novel ST354 SCCmec II–III isolates related to the worldwide ST71 clone
by
MURAMATSU, Y.
,
KOIZUMI, A.
,
ISHIHARA, K.
in
Animals
,
Anti-Bacterial Agents - pharmacology
,
Antimicrobial agents
2016
The recent appearance of methicillin-resistant Staphylococcus pseudintermedius (MRSP) is a concern for both veterinary and human healthcare. MRSP clonal lineages with sequence type (ST) 71-spa t02-staphylococcal cassette chromosome mec (SCCmec) II–III and ST68-spa t06-SCCmec V have spread throughout Europe and North America, respectively. The current study compared the molecular characteristics of 43 MRSP isolates from dogs in Japan with those of MRSP from previous reports using multilocus sequence typing based on seven housekeeping genes, SCCmec typing, and detection of antimicrobial resistance genes. Three related clonal lineages, ST71, ST169, and the newly registered ST354, were observed in SCCmec II–III isolates from Japan, despite MRSP SCCmec II–III isolates being thought to belong to a single clonal lineage. The majority of SCCmec II–III isolates belonging to ST169 (9/11) and ST354 (3/3), but not ST71 (0/11), harboured tetM. Four STs were observed for the SCCmec V isolates; however, neither ST68 nor related STs were found in the Japanese MRSP isolates. In conclusion, MRSP SCCmec II–III isolates from Japan belonged to ST71 and related STs (ST169 and ST354). A variety of MRSP SCCmec V clones, including some novel clones, were identified.
Journal Article
Epigenetic aberration of the human REELIN gene in psychiatric disorders
2007
Epigenetic genome modifications such as DNA methylation appear to be involved in various diseases. Here, we suggest that the levels of DNA methylation at the
BssH
II methylation-sensitive restriction enzyme sites in the human
REELIN
(
RELN
) gene in the forebrain vary among individuals. Interestingly, although a statistically significant correlation between the levels of DNA methylation in
RELN
and age was detected in healthy individuals, no such correlations were seen in either schizophrenic or bipolar patients. In addition, reverse correlations between DNA methylation levels and
RELN
expression were also detected in postmortem brain RNA and on
in vitro
assay. These data suggest the possibility that epigenetic aberration from the normal DNA methylation status of
RELN
may confer susceptibility to psychiatric disorders.
Journal Article