115 research outputs found
ASTE CO(3-2) Observations of the Barred Spiral Galaxy M 83: I. Correlation between CO(3-2)/CO(1-0) Ratios and Star Formation Efficiencies
We present CO(J=3-2) emission observations with the Atacama Submillimeter
Telescope Experiment (ASTE) toward the 5' x 5' (or 6.6 x 6.6 kpc at the
distance D = 4.5 Mpc) region of the nearby barred spiral galaxy M 83. We
successfully resolved the major structures, i.e., the nuclear starburst region,
bar, and inner spiral arms in CO(J=3-2) emission at a resolution of 22'' (or
480 pc), showing a good spatial coincidence between CO(J=3-2) and 6 cm
continuum emissions. We found a global CO(J=3-2) luminosity L'_CO(3-2) of 5.1 x
10^8 K km s^-1 pc^2 within the observed region. We also found L'_CO(3-2) in the
disk region (0.5 < r < 3.5 kpc) of 4.2 x 10^8 K km s^-1 pc^2, indicating that
CO(J=3-2) emission in the disk region significantly contributes to the global
L'_CO(3-2). From a comparison of a CO(J=3-2) data with CO(J=1-0) intensities
measured with Nobeyama 45-m telescope, we found that the radial profile of
CO(J=3-2)/CO(J=1-0) integrated intensity ratio R_3-2/1-0 is almost unity in the
central region (r < 0.25 kpc), whereas it drops to a constant value, 0.6--0.7,
in the disk region. The radial profile of star formation efficiencies (SFEs),
determined from 6 cm radio continuum and CO(J=1-0) emission, shows the same
trend as that of R_3-2/1-0. At the bar-end (r ~ 2.4 kpc), the amounts of
molecular gas and the massive stars are enhanced when compared with other disk
regions, whereas there is no excess of R_3-2/1-0 and SFE in that region. This
means that a simple summation of the star forming regions at the bar-end and
the disk cannot reproduce the nuclear starburst of M 83, implying that the
spatial variation of the dense gas fraction traced by R_3-2/1-0 governs the
spatial variation of SFE in M 83.Comment: 13 pages, 11 figures, PASJ in press, version with high resolution
figures is available via http://www.nro.nao.ac.jp/~z5001km/m83-aste.pd
A CONCEPT FOR PREPAREDNESS AGAINST LEVEL 2 DISASTER RISK
The Japan Society of Civil Engineers proposed to introduce the earthquake motion of level 2 to
reflect the seismic forces of the Great Hanshin-Awaji Earthquake in 1995. After the Great East Japan Earthquake
in 2011, the undertaking of “human based” soft measures for evacuation in the case of tsunamis that exceed the
conventionally assumed scale of level 1 was discussed; design methods that allow facilities to withstand tsunamis
in addition to conventional seismic forces are in demand. The level 2 disasters experienced in Japan were
incorporated into design concepts only after such large disasters occurred. However, actual level 2 disasters
include events other than earthquakes and tsunamis. Increasing seawater temperature due to global warming will
induce sea level rise, and typhoons will likely become larger in scale. Disastrous events that exceed conventional
design conditions in high tides are more likely to occur. The three largest bay regions in Japan, where large
hinterlands lie below sea level, require examination to clarify these risks.
The authors reviewed various phenomena and present that risk management on the basis of level 2 disaster risks
is of great importance
Prolongation of total permissible circulatory arrest duration by deep hypothermic intermittent circulatory arrest
AbstractObjective: We determined whether the duration of permissible circulatory arrest could be prolonged by deep hypothermic intermittent circulatory arrest. Methods: Twenty-five beagles were cooled on bypass to 18° C to initiate deep hypothermia that was maintained for 3 hours. Five protocols were then studied: group 1, uninterrupted bypass during hypothermia; group 2, arrest for 40 minutes during hypothermia; group 3, arrest for 60 minutes during hypothermia; group 4, arrest for 80 minutes during hypothermia; and group 5, intermittent circulatory arrest, consisting of six cycles of 20 minutes of arrest followed by 10 minutes of systemic recirculation during hypothermia (total, 120 minutes of arrest). The oxyhemoglobin concentration in the brain was measured with near infrared spectrophotometry. Results: In groups 2, 3, and 4, the oxyhemoglobin concentration in the brain decreased continuously after arrest, finally reaching a plateau after 24.9 ± 1.2 minutes. This finding suggested that the available cerebral oxyhemoglobin was depleted. In contrast, the available cerebral oxyhemoglobin was not depleted during hypothermic intermittent arrest in group 5. The mitochondrial respiratory control index was significantly lower in group 4 than in the other groups (p < 0.05). However, there were no significant differences in the respiratory control index for groups 1, 2, 3, and 5. Moreover, the formation of brain edema was significantly lower in group 5 than in the other groups (p < 0.05). Conclusions: These results indicate that deep hypothermic intermittent arrest can increase the duration of total permissible circulatory arrest and will be a useful modality when prolonged arrest is anticipated. (J Thorac Cardiovasc Surg 1998;116:163-70
Less Invasive Surgery under VATS for Synchronous Bilateral Lung Cancers
A patient with synchronous bilateral lung cancer is described. She was successfully treated with less invasive surgery by right S10 wedge resection using Video-assisted thoracic surgery (VATS) and left S6 segmentectomy. We judged she had synchronous primary lung cancers in the bilateral lung by histological study. She has remained well for 31 months. VATS is an effective approach for multicentric primary lung cancers and minimize the surgical stress of the simultaneous resection of bilateral tumor
A Search for CO(J=3-2) Emission from the Host Galaxy of GRB 980425 with the Atacama Submillimeter Telescope Experiment
We report on a deep search for CO(J=3-2) line emission from the host galaxy
of GRB 980425 with the Atacama Submillimeter Telescope Experiment (ASTE). We
observed five points of the galaxy covering the entire region. After combining
all of the spectra, we obtained a global spectrum with the rms noise level of
3.3 mK in T_mb scale at a velocity resolution of 10 km s^-1. No significant
emission was detected, though we find a marginal emission feature in the
velocity range corresponding to the redshift of the galaxy. We derive 3 sigma
upper limits on the global properties: the velocity-integrated CO(3-2)
intensity of I_CO(3-2) < 0.26 K km s^-1 by adopting a velocity width of 67 km
s^-1; the H_2 column density of N(H_2) < 3 x 10^20 cm^-2; the molecular gas
mass of M(H_2) < 3 x 10^8 M_sun, by assuming a CO line luminosity to H_2
molecular gas mass conversion factor of X_CO = 5.0 x 10^20 cm^-2 (K km
s^-1)^-1; and the star formation rate of SFR < 0.1 M_sun yr^-1, based on the
Schmidt law. The SFR is consistent with the previous results of H_alpha and
mid-IR observations, thereby suggesting that there is no significant obscured
star formation in the host galaxy of GRB 980425. This result implies that there
is a variety of GRB hosts with regard to the presence of obscured star
formation.Comment: 7 pages, 4 figure
Dense Molecular Clumps associated with the LMC Supergiant Shells LMC 4 \& LMC 5
We investigate the effects of Supergiant Shells (SGSs) and their interaction
on dense molecular clumps by observing the Large Magellanic Cloud (LMC) star
forming regions N48 and N49, which are located between two SGSs, LMC 4 and LMC
5. CO (=3-2, 1-0) and CO (=1-0) observations with the ASTE
and Mopra telescopes have been carried out towards these regions. A clumpy
distribution of dense molecular clumps is revealed with 7 pc spatial
resolution. Large velocity gradient analysis shows that the molecular hydrogen
densities () of the clumps are distributed from low to high
density (- cm) and their kinetic temperatures () are typically high (greater than K). These clumps seem to be in the
early stages of star formation, as also indicated from the distribution of
H, young stellar object candidates, and IR emission. We found that the
N48 region is located in the high column density HI envelope at the interface
of the two SGSs and the star formation is relatively evolved, whereas the N49
region is associated with LMC 5 alone and the star formation is quiet. The
clumps in the N48 region typically show high and ,
which are as dense and warm as the clumps in LMC massive cluster-forming areas
(30 Dor, N159). These results suggest that the large-scale structure of the
SGSs, especially the interaction of two SGSs, works efficiently on the
formation of dense molecular clumps and stars.Comment: 26 pages, 7 tables, 16 figure
Dense Clumps in Giant Molecular Clouds in the Large Magellanic Cloud: Density and Temperature Derived from CO() Observations
In order to precisely determine temperature and density of molecular gas in
the Large Magellanic Cloud, we made observations of optically thin
CO() transition by using the ASTE 10m telescope toward 9 peaks
where CO() clumps were previously detected with the same
telescope. The molecular clumps include those in giant molecular cloud (GMC)
Types I (with no signs of massive star formation), II (with HII regions only),
and III (with HII regions and young star clusters). We detected
CO() emission toward all the peaks and found that their
intensities are 3 -- 12 times lower than those of CO(). We
determined the intensity ratios of CO() to CO(),
, and CO() to CO(),
, at 45\arcsec resolution. These ratios were used for
radiative transfer calculations in order to estimate temperature and density of
the clumps. The parameters of these clumps range kinetic temperature
= 15 -- 200 K, and molecular hydrogen gas density
= 8 -- 7 cm. We confirmed
that the higher density clumps show higher kinetic temperature and that the
lower density clumps lower kinetic temperature at a better accuracy than in the
previous work. The kinetic temperature and density increase generally from a
Type I GMC to a Type III GMC. We interpret that this difference reflects an
evolutionary trend of star formation in molecular clumps. The
and kinetic temperature of the clumps are well correlated
with H flux, suggesting that the heating of molecular gas
= -- cm can be explained by stellar FUV
photons.Comment: 39 pages, 7 figures, 4 tables. Accepted for publication in The
Astronomical Journa
Surgery for Traumatic Injury of the Trachea and Bronchus
Surgery for traumatic disruption of the trachea and the bronchus was evaluated with respect to the surgical outcome in three with tracheal injury and four with bronchial injury. In this series, the results were satisfied except for one who underwent delayed operation. Experience seems to indicate that the primary care to ensure security of air way is of great value in life-saving and guarantee of the outcome including pulmonary function following surgery. In conclusion, it is emphasized that the fortuitous result and preservation of pulmonary function are mandatory for pertinent treatment with expediously precise diagnosis
Surgery for Early Esophageal Carcinoma
Early esophageal carcinomas are clinicopathologically evaluated in 11 patients whose carcinomas are limited to the epithelium (ep) and the mucosa (mm). Most of ep and mm carcinomas were detected by mass-screening without any symptom. Even when mass examination for gastric lesion is attempted, precise examination of the esophagus should be made at the same time. It is assured that a ep and mm esophageal carcinoma ensured satisfactory outcome. It is emphasized that early detection is only a way to improve the surgical outcome of the treatment for esophageal carcinomas
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