We present an atlas of ultraviolet and infrared images of ∼ 15, 750 local (d 50 Mpc) galaxies, as observed by NASA's WISE and GALEX missions. These maps have matched resolution (FWHM 7.5 and 15 ), matched astrometry, and a common procedure for background removal. We demonstrate that they agree well with resolved intensity measurements and integrated photometry from previous surveys. This atlas represents the first part of a program (the z = 0 Multi-wavelength Galaxy Synthesis) to create a large, uniform database of resolved measurements of gas and dust in nearby galaxies. The images and associated catalogs will be publicly available at the NASA/IPAC Infrared Science Archive. This atlas allows us estimate local and integrated star formation rates (SFRs) and stellar masses (M ) across the local galaxy population in a uniform way. In the appendix, we use the population synthesis fits of Salim et al. (2016Salim et al. ( , 2018 to calibrate integrated M and SFR estimators based on GALEX and WISE. Because they leverage an SDSS-base training set of > 100, 000 galaxies, these calibrations have high precision and allow us to rigorously compare local galaxies to Sloan Digital Sky Survey results. We provide these SFR and M estimates for all galaxies in our sample and show that our results yield a "main sequence" of star forming galaxies comparable to previous work. We also show the distribution of intensities from resolved galaxies in NUV-to-WISE1 vs. WISE1-to-WISE3 space, which captures much of the key physics accessed by these bands.
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain EDL933 harbors multiple prophage-associated open reading frames (ORFs) in its genome which are highly homologous to the chromosomal nanS gene. The latter is part of the nanCMS operon, which is present in most E. coli strains and encodes an esterase which is responsible for the monodeacetylation of 5-N-acetyl-9-O-acetyl neuraminic acid (Neu5,9Ac 2 ). Whereas one prophage-borne ORF (z1466) has been characterized in previous studies, the functions of the other nanS-homologous ORFs are unknown. In the current study, the nanS-homologous ORFs of EDL933 were initially studied in silico. Due to their homology to the chromosomal nanS gene and their location in prophage genomes, we designated them nanS-p and numbered the different nanS-p alleles consecutively from 1 to 10. The two alleles nanS-p2 and nanS-p4 were selected for production of recombinant proteins, their enzymatic activities were investigated, and differences in their temperature optima were found. Furthermore, a function of these enzymes in substrate utilization could be demonstrated using an E. coli C600⌬nanS mutant in a growth medium with Neu5,9Ac 2 as the carbon source and supplementation with the different recombinant NanS-p proteins. Moreover, generation of sequential deletions of all nanS-p alleles in strain EDL933 and subsequent growth experiments demonstrated a gene dose effect on the utilization of Neu5,9Ac 2 . Since Neu5,9Ac 2 is an important component of human and animal gut mucus and since the nutrient availability in the large intestine is limited, we hypothesize that the presence of multiple Neu5,9Ac 2 esterases provides them a nutrient supply under certain conditions in the large intestine, even if particular prophages are lost. IMPORTANCEIn this study, a group of homologous prophage-borne nanS-p alleles and two of the corresponding enzymes of enterohemorrhagic E. coli (EHEC) O157:H7 strain EDL933 that may be important to provide alternative genes for substrate utilization were characterized. Enterohemorrhagic Escherichia coli (EHEC) bacteria are foodborne pathogens that cause severe human gastrointestinal illness characterized by bloody diarrhea and hemolytic-uremic syndrome (HUS) (1, 2). EHEC are very heterogeneous in their genome sizes and structures as well as in their virulence gene composition (3, 4). The major pathogenicity factors of strains of classical EHEC serogroups such as O157, O26, O111, O145, and O103 are production of one or more Shiga toxins (Stx) and development of attaching and effacing lesions in the human large intestine (5). The latter effect is caused by the translocation of effector proteins into eukaryotic cells by a type III secretion system encoded by the locus of enterocyte effacement (LEE) (6). Besides LEE-positive EHEC strains, LEE-negative EHEC strains such as O113:H21 strain 98NK2 and the O104:H4 clone have caused severe human disease and outbreaks (7,8). Stx are generally encoded in the genome of lambdoid phages. EHEC strains can carry one or mor...
We combine Hubble Space Telescope (HST) Paschen β (Paβ) imaging with ground-based, previously published Hα maps to estimate the attenuation affecting Hα, A(Hα), across the nearby, face-on galaxies NGC 5194 and NGC 6946. We estimate A(Hα) in ∼ 2,000 independent 2 ∼ 75 pc diameter apertures in each galaxy, spanning out to a galactocentric radius of almost 10 kpc. In both galaxies, A(Hα) drops with radius, with a bright, high attenuation inner region, though in detail the profiles differ between the two galaxies. Regions with the highest attenuation-corrected Hα luminosity show the highest attenuation, but the observed Hα luminosity of a region is not a good predictor of attenuation in our data. Consistent with much previous work, the IR-to-Hα color does a good job of predicting A(Hα). We calculate the best-fit empirical coefficients for use combining Hα with 8, 12, 24, 70, or 100µm to correct for attenuation. These agree well with previous work but we also measure significant scatter around each of these linear relations. The local atomic plus molecular gas column density, N (H), also predicts A(Hα) well. We show that a screen with magnitude ∼ 0.2 times that expected for a Milky Way gas-to-dust value does a reasonable job of explaining A(Hα) as a function of N (H). This could be expected if only ∼ 40% of gas and dust directly overlap regions of Hα emission.
Summary Multistate outbreaks of salmonellosis associated with live poultry contact have been occurring with increasing frequency. In 2013, multistate outbreaks of salmonellosis were traced back to exposure to live poultry, some of which were purchased at a national chain of farm stores (Farm store chain Y). This study was conducted at 36 stores of Farm store chain Y and was concurrent with the timing of exposure for the human outbreaks of salmonellosis in 2013. We used environmental swabs of arriving shipment boxes of hatchling poultry and shipment tracking information to examine the distribution, diversity and anti-microbial resistance of non-typhoidal Salmonella (NTS) across farm stores and hatcheries. Isolates recovered from shipment boxes underwent serotyping, anti-microbial resistance (AMR) testing and pulsed-field gel electrophoresis (PFGE). Postal service tracking codes from the shipment boxes were used to determine the hatchery of origin. The PFGE patterns were compared with the PFGE patterns of NTS causing outbreaks of salmonellosis in 2013. A total of 219 hatchling boxes from 36 stores in 13 states were swabbed between 15 March 2013 and 18 April 2013. NTS were recovered from 59 (27%) of 219 hatchling boxes. Recovery was not significantly associated with species of hatchlings, number of birds in the shipment box, or the presence of dead, injured or sick birds. Four of the 23 PFGE patterns and 23 of 50 isolates were indistinguishable from strains causing human outbreaks in 2013. For serotypes associated with human illnesses, PFGE patterns most frequently recovered from shipment boxes were also more frequent causes of human illness. Boxes positive for the same PFGE pattern most frequently originated from the same mail-order hatchery. Only one of 59 isolates was resistant to anti-microbials used to treat Salmonella infections in people. This study provides critical information to address recurrent human outbreaks of salmonellosis associated with mail-order hatchling poultry.
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