147 research outputs found
Stacked phase-space density of galaxies around massive clusters: Comparison of dynamical and lensing masses
We present a measurement of average histograms of line-of-sight velocities
over pairs of galaxies and galaxy clusters. Since the histogram can be measured
at different galaxy-cluster separations, this observable is commonly referred
to as the stacked phase-space density. We formulate the stacked phase-space
density based on a halo-model approach so that the model can be applied to real
samples of galaxies and clusters. We examine our model by using an actual
sample of massive clusters with known weak-lensing masses and spectroscopic
observations of galaxies around the clusters. A likelihood analysis with our
model enables us to infer the spherical-symmetric velocity dispersion of
observed galaxies in massive clusters. We find the velocity dispersion of
galaxies surrounding clusters with their lensing masses of to be at the 68\%
confidence level. Our constraint confirms that the relation between the galaxy
velocity dispersion and the host cluster mass in our sample is consistent with
the prediction in dark-matter-only N-body simulations under General Relativity.
Assuming that the Poisson equation in clusters can be altered by an effective
gravitational constant of , our measurement of the velocity
dispersion can place a tight constraint of at length scales of a few Mpc about Giga years ago,
where is the Newton's constant.Comment: 22 pages, 8 figures, 3 tables. Accepted for publication in MNRA
ICTV Virus Taxonomy Profile: Megabirnaviridae
Megabirnaviridae is a family of non-enveloped spherical viruses with dsRNA genomes of two linear segments, each of 7.2-8.9 kbp, comprising 16.1 kbp in total. The genus Megabirnavirus includes the species Rosellinia necatrix megabirnavirus 1, the exemplar isolate of which infects the white root rot fungus (Rosellinia necatrix) to which it confers hypovirulence. Megabirnaviruses are characterized by their bisegmented genome with large 5'-untranslated regions (1.6 kb) upstream of both 5'-proximal coding strand ORFs, and large protrusions on the particle surface. This is a summary of the ICTV Report on the family Megabirnaviridae, which is available at ictv.global/report/megabirnaviridae
Content-based CT image retrieval system using deep learning: Preliminary assessment of its accuracy for classifying lesion patterns and retrieving similar cases among patients with diffuse lung diseases
Practical image retrieval systems must fully use image databases. We investigated the accuracy of our content-based computer tomography (CT) image retrieval system (CB-CTIRS) for classifying lesion patterns and retrieving similar cases in patients with diffuse lung diseases. The study included 503 individuals, with 328 having diffuse lung disease and 175 having normal chest CT scans. Among the former, we randomly selected ten scans that revealed one of five specific patterns [consolidation, ground-glass opacity (GGO), emphysema, honeycombing, or micronodules: two cases each]. Two radiologists separated the squares into six categories (five abnormal patterns and one normal pattern) to create a reference standard. Subsequently, each square was entered into the CB-CTIRS, and the F-score used to classify squares was determined. Next, we selected 15 cases (three per pattern) among the 503 cases, which served as the query cases. Three other radiologists graded the similarity between the retrieved and query cases using a 5-point grading system, where grade 5 = similar in both the opacity pattern and distribution and 1 = different therein. The F-score was 0.71 for consolidation, 0.63 for GGO, 0.74 for emphysema, 0.61 for honeycombing, 0.15 for micronodules, and 0.67 for normal lung. All three radiologists assigned grade 4 or 5 to 67.7% of retrieved cases with consolidation, emphysema, or honeycombing, and grade 2 or 3 to 67.7% of the retrieved cases with GGO or micronodules. The retrieval accuracy of CB-CTIRS is satisfactory for consolidation, emphysema, and honeycombing but not for GGO or micronodules
Prevalence and Distribution of Thoracic and Lumbar Compressive Lesions in Cervical Spondylotic Myelopathy
Study DesignRetrospective cross-sectional study.PurposeThis study analyzed the prevalence and distribution of horacic and lumbar compressive lesions in cervical spondylotic myelopathy as well as their relationships with cervical developmental spinal canal stenosis (DCS) by using whole-spine postmyelographic computed tomography.Overview of LiteratureThere are few studies on missed compressive lesions of the spinal cord or cauda equina at the thoracolumbar level in cervical spondylotic myelopathy. Furthermore, the relationships between DCS, and the prevalence and distribution of thoracic and lumbar compressive lesions are unknown.MethodsEighty patients with symptomatic cervical spondylotic myelopathy were evaluated. Preoperative image data were obtained. Patients were classified as DCS or non-DCS (n=40 each) if their spinal canal longitudinal diameter was <12 mm at any level or ≥12 mm at all levels, respectively. Compressive lesions in the anterior and anteroposterior parts, ligamentum flavum ossification, posterior longitudinal ligament ossification, and spinal cord tumors at the thoracolumbar levels were analyzed.ResultsCompressive lesions in the anterior and anteroposterior parts were observed in 13 (16.3%) and 45 (56.3%) patients, respectively. Ligamentum flavum and posterior longitudinal ligament ossification were observed in 19 (23.8%) and 3 (3.8%) patients, respectively. No spinal cord tumors were observed. Thoracic and lumbar compressive lesions of various causes tended to be more common in DCS patients than non-DCS patients, although the difference was statistically insignificant.ConclusionsSurveying compressive lesions and considering the thoracic and lumbar level in cervical spondylotic myelopathy in DCS patients are important for preventing unexpected neurological deterioration and predicting accurate neurological condition after cervical surgery
動的再構成可能並列VLSIプロセッサの設計と評価
In the sensor feedback control of intelligent robots, the delay time must be reduced for a large number od multioperand multiply-additions. To reduce the delay time for the multiply-additions, the architecture of the dynamically reconfigurable parallel VLSI processors are proposed. In each processor element (PE), a switch circuit is provided to change the direct connection between the multipliers and adders,so that the overhead in data transfer is reduced. In this paper, we report the delay time of the switch circuit based on a 0.18μm CMOS design rule
Suzaku Observation of Abell 1689: Anisotropic Temperature and Entropy Distributions Associated with the Large-Scale Structure
(Abridged) We present results of Suzaku observations of the intracluster
medium (ICM) in Abell 1689, combined with complementary analysis of the SDSS
data and weak and strong lensing analysis of Subaru/Suprime-Cam and HST/ACS
observations. Faint X-ray emission from the ICM around the virial radius is
detected at 4.0 sigma significance. We find anisotropic gas temperature and
entropy distributions in cluster outskirts correlated with large-scale
structure of galaxies. The high temperature and entropy region in the
northeastern (NE) outskirts is connected to an overdense filamentary structure.
The outskirt regions in contact with low density void environments have low gas
temperatures and entropies, deviating from hydrostatic equilibrium. These
results suggest that thermalization of the ICM occurs faster along the
filamentary structures than the void regions. A joint X-ray and lensing
analysis shows that the hydrostatic mass is of spherical lensing
one but comparable to a triaxial halo mass within errors in 0.6r_{2500} \simlt
r \simlt 0.8r_{500}, and that it is significantly biased as low as \simlt60%
within , irrespective of mass models. The thermal gas pressure
within is, at most, --60% of the total pressure to balance
fully the gravity of the spherical lensing mass, and --40% around the
virial radius. Although these constitute lower limits when one considers the
possible halo triaxiality, these small relative contributions of thermal
pressure would require additional sources of pressure, such as bulk and/or
turbulent motions.Comment: 24 pages, 15 figures, 9 tables. Accepted for publication in Ap
Transient left ventricular apical ballooning without coronary artery stenosis: a novel heart syndrome mimicking acute myocardial infarction
AbstractOBJECTIVESTo determine the clinical features of a novel heart syndrome with transient left ventricular (LV) apical ballooning, but without coronary artery stenosis, that mimics acute myocardial infarction, we performed a multicenter retrospective enrollment study.BACKGROUNDOnly several case presentations have been reported with regard to this syndrome.METHODSWe analyzed 88 patients (12 men and 76 women), aged 67 ± 13 years, who fulfilled the following criteria: 1) transient LV apical ballooning, 2) no significant angiographic stenosis, and 3) no known cardiomyopathies.RESULTSThirty-eight (43%) patients had preceding aggravation of underlying disorders (cerebrovascular accident [n = 3], epilepsy [n = 3], exacerbated bronchial asthma [n = 3], acute abdomen [n = 7]) and noncardiac surgery or medical procedure (n = 11) at the onset. Twenty-four (27%) patients had emotional and physical problems (sudden accident [n = 2], death/funeral of a family member [n = 7], inexperience with exercise [n = 6], quarreling or excessive alcohol consumption [n = 5] and vigorous excitation [n = 4]). Chest symptoms (67%), electrocardiographic changes (ST elevation [90%], Q-wave formation [27%] and T-wave inversion [97%]) and elevated creatine kinase (56%) were found. After treatment of pulmonary edema (22%), cardiogenic shock (15%) and ventricular tachycardia/fibrillation (9%), 85 patients had class I New York Heart Association function on discharge. The LV ejection fraction improved from 41 ± 11% to 64 ± 10%. Transient intraventricular pressure gradient and provocative vasospasm were documented in 13/72 (18%) and 10/48 (21%) of the patients, respectively. During follow-up for 13 ± 14 months, two patients showed recurrence, and one died suddenly.CONCLUSIONSA novel cardiomyopathy with transient apical ballooning was reported. Emotional or physical stress might play a key role in this cardiomyopathy, but the precise etiologic basis still remains unclear
Indocyanine green fluorescence-navigated laparoscopic metastasectomy for peritoneal metastasis of hepatocellular carcinoma: a case report
BackgroundIndocyanine green (ICG) can selectively accumulate in primary hepatocellular carcinoma (HCC) and its extrahepatic metastases. ICG fluorescence imaging is an extremely sensitive intraoperative tool for detecting HCC foci and can be used to detect impalpable tumors in laparoscopic surgery. Here, we report a case of a 75-year-old man who underwent peritoneal metastasis resection of HCC using a laparoscopic near-infrared imaging system and ICG fluorescence-navigated surgery.Case presentationA 75-year-old man was referred to our department for peritoneal metastasis resection of HCC. Two years before admission, he had undergone transarterial embolization and segmentectomy of segment 6 with open surgery for ruptured HCC. Computed tomography revealed a 12-mm peritoneal metastatic lesion on the abdominal wall near the cut surface of the liver. No other metastases were observed; resection of the solitary metastasis was scheduled. ICG (0.5 mg/kg body weight) was intravenously injected, 72 h preoperatively. An endoscopic, ICG near-infrared fluorescence imaging system revealed clear green fluorescence, indicating peritoneal metastasis of HCC on the abdominal wall. The tumor was resected with adequate surgical margin by partially resecting the liver and diaphragm, followed by histological confirmation as peritoneal metastasis of HCC. No recurrence was observed after 12 months of follow-up.ConclusionsICG fluorescence can be useful in laparoscopic surgery for identifying peritoneal metastasis
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