747 research outputs found
Do Bars Trigger Activity in Galactic Nuclei?
We investigate the connection between the presence of bars and AGN activity,
using a volume-limited sample of 9,000 late-type galaxies with axis ratio
and at low redshift (), selected from Sloan Digital Sky Survey Data Release 7. We find that
the bar fraction in AGN-host galaxies (42.6%) is 2.5 times higher than in
non-AGN galaxies (15.6%), and that the AGN fraction is a factor of two higher
in strong-barred galaxies (34.5%) than in non-barred galaxies (15.0%). However,
these trends are simply caused by the fact that AGN-host galaxies are on
average more massive and redder than non-AGN galaxies because the fraction of
strong-barred galaxies (\bfrsbo) increases with color and stellar
velocity dispersion. When color and velocity dispersion (or stellar mass)
are fixed, both the excess of \bfrsbo in AGN-host galaxies and the enhanced
AGN fraction in strong-barred galaxies disappears. Among AGN-host galaxies we
find no strong difference of the Eddington ratio distributions between barred
and non-barred systems. These results indicate that AGN activity is not
dominated by the presence of bars, and that AGN power is not enhanced by bars.
In conclusion we do not find a clear evidence that bars trigger AGN activity.Comment: 13 pages, 11 figures, accepted for publication in Ap
Intracorporeal Anastomosis Using Linear Stapler in Laparoscopic Distal Gastrectomy: Comparison between Gastroduodenostomy and Gastrojejunostomy
Purpose: Intracorporeal anastomosis during laparoscopic gastrectomy is becoming increasingly prevalent. However, selection of the anastomosis method after laparoscopic distal gastrectomy is equivocal because of a lack of technical feasibility and safety. We compared intracorporeal gastroduodenostomy with gastrojejunostomy using linear staplers to evaluate the technical feasibility and safety of intracorporeal anastomoses as well as its' minimally invasiveness. Materials and Methods: Retrospective analyses of a prospectively collected database for gastric cancer revealed 47 gastric cancer patients who underwent laparoscopic distal gastrectomy with either intracorporeal gastroduodenostomy or gastrojejunostomy from March 2011 to June 2011. Perioperative outcomes such as operation time, postoperative complication, and hospital stay were compared according to the type of anastomosis. Postoperative inflammatory response was also compared between the two groups using white blood cell count and high sensitivity C-reactive protein. Results: Among the 47 patients, 26 patients received gastroduodenostomy, whereas 21 patients received gastrojejunostomy without open conversion or additional mini-laparotomy incision. There was no difference in mean operation time, blood loss, and length of postoperative hospital stays. There was no statistically significant difference in postoperative complication or mortality between two groups. However, significantly more staplers were used for gastroduodenostomy than for gastrojejunostomy (n=6) than for gastroduodenostomy and (n=5). Conclusions: Intracorporeal anastomosis during laparoscopic gastrectomy using linear stapler, either gastroduodenostomy or gastrojejunostomy, shows comparable and acceptable early postoperative outcomes and are safe and feasible. Therefore, surgeons may choose either anastomosis method as long as oncological safety is guaranteedope
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Evaluation of the On-Campus Dining Service Using Importance-Performance Analysis
University foodservice is one of the largest sectors of the foodservice industry, and the college-student market is getting larger. Therefore, it is important that university foodservice needs to be monitored periodically and improved comprehensively in order to retain students as satisfied customers for on-campus foodservice. The objectives of the current study were to explore the importance and performance/satisfaction of on-campus dining service consumers, to investigate the importance-performance difference between patron and non-patron customers, and to examine the difference between gender groups. The study compared the respondents’ perceived importance and performance ratings of the dining service quality attributes using IPA. The IPA grid illustrated that food quality and sanitation fell into the Quadrant II (Keep up the Work); price into the Quadrant III (Low Priority); and service and environment into the Quadrant IV (Possible Overkill). However, according to IPA of comparison of patron versus non-patron groups and gender groups, the service attribute was allocated differently
Automated Brittle Fracture Rate Estimator for Steel Property Evaluation Using Deep Learning After Drop-Weight Tear Test
This study proposes an automated brittle fracture rate (BFR) estimator using deep learning. As the demand for line-pipes increases in various industries, the need for BFR estimation through dropweight tear test (DWTT) increases to evaluate steel's property. Conventional BFR or ductile fracture rate (DFR) estimation methods require an expensive 3D scanner. Alternatively, a rule-based approach is used with a single charge-coupled device (CCD) camera. However, it is sensitive to the hyper-parameter. To solve these problems, we propose an approach based on deep learning that has recently been successful in the fields of computer vision and image processing. The method proposed in this study is the first to use deep learning approach for BFR estimation. The proposed method consists of a VGG-based U-Net (VU-Net) which is inspired by U-Net and fully convolutional network (FCN). VU-Net includes a deep encoder and a decoder. The encoder is adopted from VGG19 and transferred with a pre-trained model with ImageNet. In addition, the structure of the decoder is the same as that of the encoder, and the decoder uses the feature maps of the encoder through concatenation operation to compensate for the reduced spatial information. To analyze the proposed VU-Net, we experimented with different depths of networks and various transfer learning approaches. In terms of accuracy used in real industrial application, we compared the proposed VU-Net with U-Net and FCN to evaluate the performance. The experiments showed that VU-Net was the accuracy of approximately 94.9 %, and was better than the other two, which had the accuracies of about 91.8 % and 93.7 %, respectively.11Ysciescopu
Performance of a lead rubber damper under cyclic shear loading and its applicability to a full-scale structure
In this paper, we investigate the performance of a new lead rubber damper (LRD) and its applicability to a full-scale structure. This device is more advanced than existing lead-rubber based isolation devices. In contrast to the existing devices, multiple lead cores are installed in the LRD in order to enhance the performance of the laminated rubber and lead. It is able to perform effectively under the application of shear force. An experiment was performed to investigate its dependency on the level of shear strain and frequency. The applicability of this new device to a full-scale structure is also examined by performing a vibration test on a five floor modal-test tower
The Presence of Two Distinct Red Giant Branches in the Globular Cluster NGC 1851
There is a growing body of evidence for the presence of multiple stellar
populations in some globular clusters, including NGC 1851. For most of these
peculiar globular clusters, however, the evidence for the multiple red
giant-branches (RGBs) having different heavy elemental abundances as observed
in Omega Centauri is hitherto lacking, although spreads in some lighter
elements are reported. It is therefore not clear whether they also share the
suggested dwarf galaxy origin of Omega Cen or not. Here we show from the CTIO
4m UVI photometry of the globular cluster NGC 1851 that its RGB is clearly
split into two in the U - I color. The two distinct RGB populations are also
clearly separated in the abundance of heavy elements as traced by Calcium,
suggesting that the type II supernovae enrichment is also responsible, in
addition to the pollutions of lighter elements by intermediate mass asymptotic
giant branch stars or fast-rotating massive stars. The RGB split, however, is
not shown in the V - I color, as indicated by previous observations. Our
stellar population models show that this and the presence of bimodal
horizontal-branch distribution in NGC 1851 can be naturally reproduced if the
metal-rich second generation stars are also enhanced in helium.Comment: 13 pages, 4 figures, accepted for publication in the Astrophysical
Journal Letter
Pseudotumor of the Omentum Associated with Migration of the Ingested Crab-Leg
Foreign body ingestion is not uncommon in clinical practice, and it may occasionally lead to penetration injuries. Emergency physicians and radiologists sometimes fail to obtain complete histories including ingestion and may overlook the possibility of foreign body-induced complications. Herein, we report a case of stomach antrum perforation due to foreign body migration. We were unaware of the patient's history of eating the Korean delicacy "Kanjang-gaejang," which is raw crab seasoned with soy sauce. Several imaging diagnostic modalities had suggested the possibility of a malignant mass in the gastrocolic ligament area. During the operation, a crab leg was discovered as the cause of an intra-abdominal abscess. The patient underwent an antrectomy, a vagotomay, and a transverse colon wedge resection. We present this unusual case of a pseudotumorous lesion caused by ingestion of Kanjang-gaejang
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