The ISO 170um Luminosity Function of Galaxies

We constructed a local luminosity function (LF) of galaxies using a flux-limited sample (S_170 > 0.195Jy) of 55 galaxies at z < 0.3 taken from the ISO FIRBACK survey at 170um. The overall shape of the 170-um LF is found to be different from that of the total 60-um LF (Takeuchi et al. 2003): the bright end of the LF declines more steeply than that of the 60-um LF. This behavior is quantitatively similar to the LF of the cool subsample of the IRAS PSCz galaxies. We also estimated the strength of the evolution of the LF by assuming the pure luminosity evolution (PLE): L(z) \propto (1+z)^Q. We obtained Q=5.0^{+2.5}_{-0.5} which is similar to the value obtained by recent Spitzer observations, in spite of the limited sample size. Then, integrating over the 170-um LF, we obtained the local luminosity density at 170um, \rho_L(170um). A direct integration of the LF gives \rho_L(170um) = 1.1 \times 10^8 h Lsun Mpc^{-3}, whilst if we assume a strong PLE with Q=5, the value is 5.2 \times 10^7 h Lsun Mpc^{-3}. This is a considerable contribution to the local FIR luminosity density. By summing up with other available infrared data, we obtained the total dust luminosity density in the Local Universe, \rho_L(dust)=1.1 \times 10^8 h Lsun Mpc^{-3}. Using this value, we estimated the cosmic star formation rate (SFR) density hidden by dust in the Local Universe. We obtained \rho_SFR(dust) \simeq 1.1-1.2 h \times 10^{-2} Msun yr^{-1} Mpc^{-3}$, which means that 58.5% of the star formation is obscured by dust in the Local Universe.Comment: A&A in pres

Genomic Analyses of Clonal Isolates Provide Clues to the Evolution of Streptococcus pneumoniae

A commentary on Rapid pneumococcal evolution in response to clinical intervention

A Far-infrared Characterization of 24 μm Selected Galaxies at 0 < z < 2.5 using Stacking at 70 μm and 160 μm in the COSMOS Field

We present a study of the average properties of luminous infrared galaxies detected directly at 24 μm in the COSMOS field using a median stacking analysis at 70 μm and 160 μm. Over 35,000 sources spanning 0 ≤ z ≤ 3 and 0.06 mJy ≤ S_(24) ≤ 3.0 mJy are stacked, divided into bins of both photometric redshift and 24 μm flux. We find no correlation of S_(70)/S_(24) flux density ratio with S_(24), but find that galaxies with higher S_(24) have a lower S_(160)/S_(24) flux density ratio. These observed ratios suggest that 24 μm selected galaxies have warmer spectral energy distributions (SEDs) at higher mid-IR fluxes, and therefore have a possible higher fraction of active galactic nuclei. Comparisons of the average S_(70)/S_(24) and S_(160)/S_(24) colors with various empirical templates and theoretical models show that the galaxies detected at 24 μm are consistent with "normal" star-forming galaxies and warm mid-IR galaxies such as Mrk 231, but inconsistent with heavily obscured galaxies such as Arp 220. We perform a χ^2 analysis to determine best-fit galactic model SEDs and total IR luminosities for each of our bins. We compare our results to previous methods of estimating L IR and find that previous methods show considerable agreement over the full redshift range, except for the brightest S_(24) sources, where they overpredict the bolometric IR luminosity at high redshift, most likely due to their warmer dust SED. We present a table that can be used as a more accurate and robust method for estimating bolometric infrared luminosity from 24 μm flux densities

Finite volume method in curvilinear coordinates for hyperbolic conservation laws

International audienceThis paper deals with the design of finite volume approximation of hyperbolic conservation laws in curvilinear coordinates. Such coordinates are encountered naturally in many problems as for instance in the analysis of a large number of models coming from magnetic confinement fusion in tokamaks. In this paper we derive a new finite volume method for hyperbolic conservation laws in curvilinear coordinates. The method is first described in a general setting and then is illustrated in 2D polar coordinates. Numerical experiments show its advantages with respect to the use of Cartesian coordinates

Ent-kaurene and ent-beyerene diterpenoids and other constituents of Thecacoris batesii

Two novel diterpenoids, thecacorins A (1) and B (2), were isolated from Thecacoris batesii and their structures were established as ent-3b,20-epoxy-16-kaurene-3a,12b-diol and ent-15-beyerene-2b,3b-diol, respectively, on the basis of extensive spectroscopic analysis, especially, 1D NMR spectra, in conjunction with 2D experiments, COSY, NOESY, HMQC and HMBC. KEY WORDS: Diterpenoids, Thecacorin A, Thecacorin B, Ent-3b,20-epoxy-16-kaurene-3a,12b-diol, Ent-15-beyerene-2b,3b-diol, Thecacoris batesii  Bull. Chem. Soc. Ethiop. 2007, 21(1), 89-94

Atypical Aeromonas salmonicida vapA type V and Vibrio spp. are predominant bacteria recovered from ballan wrasse (Labrus bergylta A.) in Scotland

Healthy and/or moribund farmed and wild ballan wrasse Labrus bergylta (>0.5 to 900 g) were sampled from hatcheries (n = 2) and Atlantic salmon cage sites (n = 8) in Scotland between February 2016 and October 2018. Less than half of the sampled individuals (n = 43, 32.3%) had been vaccinated (autogenous polyvalent vaccine; dip and/or injection) against atypical furunculosis (type V and VI) while 20 (15.0%) fish were not vaccinated and the rest (70 individuals, 52.7%) were of unknown vaccination status. Swab samples from skin lesions, gill, liver, spleen and kidney were inoculated onto a variety of bacteriological agar plates and bacteriology identification and sequencing analysis was performed on significant bacterial colonies. Atypical Aeromonas salmonicida (aAs) vapA type V was the predominant bacterial species (70/215 bacteria isolates; 32.5% of bacteria samples – 43/117 positive individual fish; 36.8%) isolated in this survey followed by Vibrio species which were the most geographically prevalent bacteria. Photobacterium indicum/profundum was also isolated from L. bergylta for the first time during this study. The collection of these bacterial isolates provides useful information for disease management. Identifying the aAs isolates involved in disease in ballan wrasse could provide vital information for improving / updating existing autogenous vaccines

Ancient RNA from Late Pleistocene permafrost and historical canids shows tissue-specific transcriptome survival

While sequencing ancient DNA (aDNA) from archaeological material is now commonplace, very few attempts to sequence ancient transcriptomes have been made, even from typically stable deposition environments such as permafrost. This is presumably due to assumptions that RNA completely degrades relatively quickly, particularly when dealing with autolytic, nuclease-rich mammalian tissues. However, given the recent successes in sequencing ancient RNA (aRNA) from various sources including plants and animals, we suspect that these assumptions may be incorrect or exaggerated. To challenge the underlying dogma, we generated shotgun RNA data from sources that might normally be dismissed for such study. Here, we present aRNA data generated from two historical wolf skins, and permafrost-preserved liver tissue of a 14,300-year-old Pleistocene canid. Not only is the latter the oldest RNA ever to be sequenced, but it also shows evidence of biologically relevant tissue specificity and close similarity to equivalent data derived from modern-day control tissue. Other hallmarks of RNA sequencing (RNA-seq) data such as exon-exon junction presence and high endogenous ribosomal RNA (rRNA) content confirms our data's authenticity. By performing independent technical library replicates using two high-throughput sequencing platforms, we show not only that aRNA can survive for extended periods in mammalian tissues but also that it has potential for tissue identification. aRNA also has possible further potential, such as identifying in vivo genome activity and adaptation, when sequenced using this technology

A Novel Approach to Constrain the Escape Fraction and Dust Content at High Redshift Using the Cosmic Infrared Background Fractional Anisotropy

The Cosmic Infrared Background (CIB) provides an opportunity to constrain many properties of the high redshift (z>6) stellar population as a whole. This background, specifically, from 1 to 200 microns, will contain any information about the era of reionization and the stars responsible for producing these ionizing photons. In this paper, we look at the fractional anisotropy delta I/I of this high redshift population, which is the ratio of the magnitude of the fluctuations (delta I) and the mean intensity (I). We show that this can be used to constrain the escape fraction of the population as a whole. The magnitude of the fluctuations of the CIB depend on the escape fraction, while the mean intensity does not. This results in lower values of the escape fraction producing higher values of the fractional anisotropy. This difference is predicted to be larger at the longer wavelengths bands (above 10 microns), albeit it is also much harder to observe in that range. We show that the fractional anisotropy can also be used to separate a dusty from a dust-free population. Finally, we discuss the constraints provided by current observations on the CIB fractional anisotropy.Comment: 8 pages, 4 figures, accepted to ApJ, some clarifications added, matches accepted versio