ABSTRACT Accurately determining the mass of galaxy clusters is fundamental for many studies of cosmology and galaxy evolution. We collect and rescale the cluster masses of 1191 clusters of estimated ...by X-ray or Sunyaev-Zeldovich measurements and use them to calibrate the optical mass proxy. The total r-band luminosity (in units of ) of these clusters is obtained by using spectroscopic and photometric data of the Sloan Digital Sky Survey (SDSS). We find that the correlation between the cluster mass and total r-band luminosity significantly evolves with redshift. After correcting for the evolution, we define a new cluster richness as the optical mass proxy. By using this newly defined richness and the recently released SDSS DR12 spectroscopic data, we update the WHL12 cluster catalog and identify 25,419 new rich clusters at high redshift. In the SDSS spectroscopic survey region, about 89% of galaxy clusters have spectroscopic redshifts. The mass can be estimated with a scatter of 0.17 dex for the clusters in the updated catalog.
Dynamical state of galaxy clusters is closely related to their observational properties in X-ray, optical and radio wavelengths. We develop a method to diagnose the substructure and dynamical state ...of galaxy clusters by using photometric data of Sloan Digital Sky Survey (SDSS). To trace mass distribution, the brightness distribution of member galaxies is smoothed by using a Gaussian kernel with a weight of their optical luminosities. After deriving the asymmetry, the ridge flatness and the normalized deviation of the smoothed optical map, we define a relaxation parameter, Γ, to quantify dynamical state of clusters. This method is applied to a test sample of 98 clusters of 0.05 < z 0.42 collected from literature with known dynamical states and can recognize dynamical state for relaxed (Γ ≥ 0) and unrelaxed (Γ < 0) clusters with a success rate of 94 per cent. We then calculate relaxation parameters of 2092 rich clusters previously identified from the SDSS, of which 28 per cent clusters are dynamically relaxed with Γ ≥ 0. We find that the dominance and absolute magnitude of the brightest cluster galaxies closely correlate with dynamical states of clusters. The emission power of radio haloes is quantitatively related to cluster dynamical state, beside the known dependence on the X-ray luminosity.
Gravitational waves are expected to be radiated by supermassive black hole binaries formed during galaxy mergers. A stochastic superposition of gravitational waves from all such binary systems would ...modulate the arrival times of pulses from radio pulsars. Using observations of millisecond pulsars obtained with the Parkes radio telescope, we constrained the characteristic amplitude of this background, Ac,yr, to be <1.0 × 10–15 with 95% confidence. This limit excludes predicted ranges for Ac,yr from current models with 91 to 99.7% probability. We conclude that binary evolution is either stalled or dramatically accelerated by galactic-center environments and that higher-cadence and shorter-wavelength observations would be more sensitive to gravitational waves.
Increasing evidence has revealed a significant association between microorganisms and oral squamous cell carcinoma (OSCC). Porphyromonas gingivalis, the keystone pathogen in chronic periodontitis, is ...considered an important potential etiologic agent of OSCC, but the underlying immune mechanisms through which P. gingivalis mediates tumor progression of the oral cancer remain poorly understood. Our cohort study showed that the localization of P. gingivalis in tumor tissues was related to poor survival of patients with OSCC. Moreover, P. gingivalis infection increased oral lesion multiplicity and size and promoted tumor progression in a 4-nitroquinoline-1 oxide (4NQO)–induced carcinogenesis mouse model by invading the oral lesions. In addition, CD11b+ myeloid cells and myeloid-derived suppressor cells (MDSCs) showed increased infiltration of oral lesions. Furthermore, in vitro observations showed that MDSCs accumulated when human-derived dysplastic oral keratinocytes (DOKs) were exposed to P. gingivalis, and CXCL2, CCL2, interleukin (IL)–6, and IL-8 may be potential candidate genes that facilitate the recruitment of MDSCs. Taken together, our findings suggest that P. gingivalis promotes tumor progression by generating a cancer-promoting microenvironment, indicating a close relationship among P. gingivalis, tumor progression of the oral cancer, and immune responses.
Abstract Based on the DESI Legacy Imaging Surveys released data and available spectroscopic redshifts, we identify 1.58 million clusters of galaxies by searching for the overdensity of the stellar ...mass distribution of galaxies within redshift slices around preselected massive galaxies, with 877,806 clusters being found for the first time. The identified clusters have an equivalent mass of M 500 ≥ 0.47 × 10 14 M ⊙ with an uncertainty of 0.2 dex. The redshift distribution of clusters extends to z ∼ 1.5, and 338,841 clusters have spectroscopic redshifts. Our cluster sample includes most of the rich optical clusters in previous catalogs, more than 95% of the massive Sunyaev–Zeldovich clusters, and 90% of the ROSAT and eROSITA X-ray clusters. From the light distributions of the member galaxies, we derive the dynamical state parameters for 27,685 rich clusters and find no significant evolution of the dynamical state with redshift. We find that the stellar mass of the brightest cluster galaxies grows by a factor of 2 since z = 1.
Colorectal cancer (CRC) incidence is higher in African Americans (AAs) compared with non-Hispanic whites (NHWs). A diet high in animal protein and fat is an environmental risk factor for CRC ...development. The intestinal microbiota is postulated to modulate the effects of diet in promoting or preventing CRC. Hydrogen sulfide, produced by autochthonous sulfidogenic bacteria, triggers proinflammatory pathways and hyperproliferation, and is genotoxic. We hypothesised that sulfidogenic bacterial abundance in colonic mucosa may be an environmental CRC risk factor that distinguishes AA and NHW.
Colonic biopsies from uninvolved or healthy mucosa from CRC cases and tumour-free controls were collected prospectively from five medical centres in Chicago for association studies. Sulfidogenic bacterial abundance in uninvolved colonic mucosa of AA and NHW CRC cases was compared with normal mucosa of AA and NHW controls. In addition, 16S rDNA sequencing was performed in AA cases and controls. Correlations were examined among bacterial targets, race, disease status and dietary intake.
AAs harboured a greater abundance of sulfidogenic bacteria compared with NHWs regardless of disease status.
-specific
was more abundant in AA cases than controls. Linear discriminant analysis of 16S rRNA gene sequences revealed five sulfidogenic genera that were more abundant in AA cases. Fat and protein intake and daily servings of meat were significantly higher in AAs compared with NHWs, and multiple dietary components correlated with a higher abundance of sulfidogenic bacteria.
These results implicate sulfidogenic bacteria as a potential environmental risk factor contributing to CRC development in AAs.
Electric traction drives have seen increased application for road, rail, marine and aerospace transportation to provide improved performance and to reduce emissions. They generally consist of a dc ...power source, a power electronic converter and an electric motor. The electric motors used in such applications require high power density to achieve small size and weight, high efficiency to reduce energy consumption, high reliability to reduce maintenance and a wide constant power speed range to minimize the need for variable gearing between the motor and the wheels.
This paper presents research work on a 12-slot ten-pole tapered axial-flux permanent-magnet machine utilizing amorphous magnetic material in the stator core. Novel loss separation techniques are ...described, including mechanical loss and locked-rotor tests. Mechanical loss estimation is based on a combination of experimental tests and 3-D finite-element model analysis using an uncut stator. The locked-rotor test is introduced to separate the stator and rotor losses by eliminating the uncertainty associated with mechanical loss. High rotor yoke losses were identified in the baseline design. The rotor design was modified and a significant improvement in efficiency was demonstrated.
Multiomic studies are increasingly performed to gain a deeper understanding of molecular processes occurring in a biological system, such as the complex microbial communities (i.e., microbiota) that ...reside the distal gut. While a combination of metabolomics and proteomics is more commonly used, multiomics studies including peptidomcis characterization are less frequently undertaken. Here, we investigated three different extraction methods, chosen for their previous use in extracting metabolites, peptides, and proteins, and compared their ability to perform metabolomic, peptidomic, and proteomic analysis of mouse cecum content. The methanol/chloroform/water extraction performed the best for metabolomic and peptidomic analysis as it detected the largest number of small molecules and identified the largest number of peptides, but the acidified methanol extraction performed best for proteomics analysis as it had the highest number of protein identifications. The methanol/chloroform/water extraction was further analyzed by identifying metabolites with tandem mass spectrometry (MS/MS) analysis and by gene ontology analysis for the peptide and protein results to provide a multiomics analysis of the gut microbiota.
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