The radio properties of optically obscured Spitzer sources

This paper analyses the radio properties of a subsample of optically obscured (R>25.5) galaxies observed at 24um by the Spitzer Space Telescope within the First Look Survey. 96 F[24um]>0.35 mJy objects out of 510 are found to have a radio counterpart at 1.4 GHz, 610 MHz or at both frequencies respectively down to ~40uJy and ~200uJy. IRAC photometry sets the majority of them in the redshift interval z [1-3] and allows for a broad distinction between AGN-dominated galaxies (~47% of the radio-identified sample) and systems powered by intense star-formation (~13%), the remaining objects being impossible to classify. The percentage of radio identifications is a strong function of 24um flux. The radio number counts at both radio frequencies suggest that the physical process(es) responsible for radio activity in these objects have a common origin regardless of whether the source shows mid-IR emission compatible with being an obscured AGN or a star-forming galaxy. We also find that both candidate AGN and star-forming systems follow (although with a large scatter) the relationship between 1.4 GHz and 24um fluxes reported by Appleton et al. (2004) which identifies sources undergoing intense star formation activity. On the other hand, the inferred radio spectral indices alpha indicate that a large fraction of objects in our sample (~60% of all galaxies with estimated alpha) may belong to the population of Ultra Steep Spectrum (USS) Sources, typically 'frustrated' radio-loud AGN. We interpret our findings as a strong indication for concurrent AGN and star-forming activity, whereby the 1.4 GHz flux is of thermal origin, while that at 610 GHz mainly stems from the nuclear source.Comment: 18 pages, 16 figures, to appear in MNRA

High-velocity neon line emission from the ULIRG IRAS F00183-7111: revealing the optically obscured base of a nuclear outflow

We report the first mid-IR detection of highly disturbed ionized gas in the ultraluminous infrared galaxy IRAS F00183-7111. The gas, traced by the 12.81um [NeII] and 15.56um [NeIII] lines, spans a velocity range of-3500 to 3000 km/s with respect to systemic velocity. Optical and near-IR spectroscopic studies show no evidence for similarly high velocity gas components in forbidden lines at shorter wavelengths. We interpret this as the result of strong extinction (Av=10-50) on the high-velocity gas, which identifies the base of the outflow traced in 5007A [OIII] as a plausible origin. Unusual excitation conditions are implied by a comparison of the mid-infrared low-excitation neon line emission and the PAH emission for a sample of 56 ULIRGs. For IRAS F00183, the neon/PAH ratio is 8 times higher than the average ratio. Similar mid-infrared kinematic and excitation characteristics are found for only 2 other ULIRGs in our sample: IRAS 12127-1412NE and IRAS 13451+1232. Both sources have an elevated neon/PAH ratio and exhibit pronounced blue wings in their 15.56um [NeIII] line profiles. IRAS 13451 even shows a strongly blue shifted and broad 14.32um [NeV] line. While for IRAS 13451 the observed [NeIII]/[NeII] and [NeV]/[NeII] line ratios indicate exposure of the blue shifted gas to direct radiation from the AGN, for IRAS F00183 and 12127 the neon line ratios are consistent with an origin in fast shocks in a high-density environment, and with an evolutionary scenario in which strongly blue shifted [Ne II] and [Ne III] emission trace the (partial) disruption of the obscuring medium around a buried AGN. The detection of strongly blue shifted [Ne V] emission in IRAS 13451 would then indicate this process to be much further advanced in this ULIRG than in IRAS F00183 and 12127, where this line is undetected.Comment: 13 pages, 10 figures, accepted for publication in the Astrophysical Journa

Molecular Characterization of Borrelia persica, the Agent of Tick Borne Relapsing Fever in Israel and the Palestinian Authority

The identification of the Tick Borne Relapsing Fever (TBRF) agent in Israel and the Palestinian Authority relies on the morphology and the association of Borrelia persica with its vector Ornithodoros tholozani. Molecular based data on B. persica are very scarce as the organism is still non-cultivable. In this study, we were able to sequence three complete 16S rRNA genes, 12 partial flaB genes, 18 partial glpQ genes, 16 rrs-ileT intergenic spacers (IGS) from nine ticks and ten human blood samples originating from the West Bank and Israel. In one sample we sequenced 7231 contiguous base pairs that covered completely the region from the 5′end of the 16S rRNA gene to the 5′end of the 23S rRNA gene comprising the whole 16S rRNA (rrs), and the following genes: Ala tRNA (alaT), Ile tRNA (ileT), adenylosuccinate lyase (purB), adenylosuccinate synthetase (purA), methylpurine-DNA glycosylase (mag), hypoxanthine-guanine phosphoribosyltransferase (hpt), an hydrolase (HAD superfamily) and a 135 bp 5′ fragment of the 23S rRNA (rrlA) genes. Phylogenic sequence analysis defined all the Borrelia isolates from O. tholozani and from human TBRF cases in Israel and the West Bank as B. persica that clustered between the African and the New World TBRF species. Gene organization of the intergenic spacer between the 16S rRNA and the 23S rRNA was similar to that of other TBRF Borrelia species and different from the Lyme disease Borrelia species. Variants of B. persica were found among the different genes of the different isolates even in the same sampling area

Linking radio to infrared: a radio source count model

We investigate the populations and evolution of normal and active galaxies by extending the infrared source count model of Rowan-Robinson (2001) into the radio. The FIR-radio correlation is used to extend the SEDs to the radio region and it is assumed that there are two distinct populations of quasar: radio loud and radio quiet. It is found that the radio luminosity function and source count data are best fit when the fraction of quasars that are radio loud is allowed to increase with optical luminosity. This implications for this are discussed, as are the possible causes for the variation in radio loud fraction.Comment: 9 pages (TeX file), 9 figures (eps format), submitted to MNRAS and corrected for referee's comment

Chandra and Spitzer unveil heavily obscured quasars in the SWIRE/Chandra Survey

Using the large multi-wavelength data set in the chandra/SWIRE Survey (0.6 square degrees in the Lockman Hole), we show evidence for the existence of highly obscured (Compton-thick) AGN, estimate a lower limit to their surface density and characterize their multi-wavelength properties. Two independent selection methods based on the X-ray and infrared spectral properties are presented. The two selected samples contain 1) 5 X-ray sources with hard X-ray spectra and column densities > 10^24 cm-2, and 2) 120 infrared sources with red and AGN-dominated infrared spectral energy distributions (SEDs). We estimate a surface density of at least 25 Compton-thick AGN per square degree detected in the infrared in the chandra/SWIRE field of which ~40% show distinct AGN signatures in their optical/near-infrared SEDs, the remainings being dominated by the host-galaxy emission. Only ~33% of all Compton-thick AGN are detected in the X-rays at our depth (F(0.3-8 keV)>10^-15 erg/cm2/s. We report the discovery of two sources in our sample of Compton-thick AGN, SWIRE_J104409.95+585224.8 (z=2.54) and SWIRE_J104406.30+583954.1 (z=2.43), which are the most luminous Compton-thick AGN at high-z currently known. The properties of these two sources are discussed in detail with an analysis of their spectra, SEDs, luminosities and black-hole masses.Comment: ApJ accepted (to appear in May 2006 issue, vol. 642, of ApJ) Figures 2, 3, and 14 have been degraded due to space consideration

RENEB intercomparisons applying the conventional Dicentric Chromosome Assay (DCA)

Purpose: Two quality controlled inter-laboratory exercises were organized within the EU project ‘Realizing the European Network of Biodosimetry (RENEB)’ to further optimize the dicentric chromosome assay (DCA) and to identify needs for training and harmonization activities within the RENEB network. Materials and methods: The general study design included blood shipment, sample processing, analysis of chromosome aberrations and radiation dose assessment. After manual scoring of dicentric chromosomes in different cell numbers dose estimations and corresponding 95% confidence intervals were submitted by the participants. Results: The shipment of blood samples to the partners in the European Community (EU) were performed successfully. Outside the EU unacceptable delays occurred. The results of the dose estimation demonstrate a very successful classification of the blood samples in medically relevant groups. In comparison to the 1st exercise the 2nd intercomparison showed an improvement in the accuracy of dose estimations especially for the high dose point. Conclusions: In case of a large-scale radiological incident, the pooling of ressources by networks can enhance the rapid classification of individuals in medically relevant treatment groups based on the DCA. The performance of the RENEB network as a whole has clearly benefited from harmonization processes and specific training activities for the network partners

Seven features of safety in maternity units: a framework based on multisite ethnography and stakeholder consultation

Background: Reducing avoidable harm in maternity services is a priority globally. As well as learning from mistakes, it is important to produce rigorous descriptions of ‘what good looks like’. Objective: We aimed to characterise features of safety in maternity units and to generate a plain language framework that could be used to guide learning and improvement. Methods: We conducted a multisite ethnography involving 401 hours of non-participant observations 33 semistructured interviews with staff across six maternity units, and a stakeholder consultation involving 65 semistructured telephone interviews and one focus group. Results: We identified seven features of safety in maternity units and summarised them into a framework, named For Us (For Unit Safety). The features include: (1) commitment to safety and improvement at all levels, with everyone involved; (2) technical competence, supported by formal training and informal learning; (3) teamwork, cooperation and positive working relationships; (4) constant reinforcing of safe, ethical and respectful behaviours; (5) multiple problem-sensing systems, used as basis of action; (6) systems and processes designed for safety, and regularly reviewed and optimised; (7) effective coordination and ability to mobilise quickly. These features appear to have a synergistic character, such that each feature is necessary but not sufficient on its own: the features operate in concert through multiple forms of feedback and amplification. Conclusions: This large qualitative study has enabled the generation of a new plain language framework—For Us—that identifies the behaviours and practices that appear to be features of safe care in hospital-based maternity units

Rationalising the role of Keratin 9 as a biomarker for Alzheimer’s disease

Keratin 9 was recently identified as an important component of a biomarker panel which demonstrated a high diagnostic accuracy (87%) for Alzheimer’s disease (AD). Understanding how a protein which is predominantly expressed in palmoplantar epidermis is implicated in AD may shed new light on the mechanisms underlying the disease. Here we use immunoassays to examine blood plasma expression patterns of Keratin 9 and its relationship to other AD-associated proteins. We correlate this with the use of an in silico analysis tool VisANT to elucidate possible pathways through which the involvement of Keratin 9 may take place. We identify possible links with Dickkopf-1, a negative regulator of the wnt pathway, and propose that the abnormal expression of Keratin 9 in AD blood and cerebrospinal fluid may be a result of blood brain barrier dysregulation and disruption of the ubiquitin proteasome system. Our findings suggest that dysregulated Keratin 9 expression is a consequence of AD pathology but, as it interacts with a broad range of proteins, it may have other, as yet uncharacterized, downstream effects which could contribute to AD onset and progression

NCBI's Virus Discovery Hackathon:Engaging Research Communities to Identify Cloud Infrastructure Requirements

A wealth of viral data sits untapped in publicly available metagenomic data sets when it might be extracted to create a usable index for the virological research community. We hypothesized that work of this complexity and scale could be done in a hackathon setting. Ten teams comprised of over 40 participants from six countries, assembled to create a crowd-sourced set of analysis and processing pipelines for a complex biological data set in a three-day event on the San Diego State University campus starting 9 January 2019. Prior to the hackathon, 141,676 metagenomic data sets from the National Center for Biotechnology Information (NCBI) Sequence Read Archive (SRA) were pre-assembled into contiguous assemblies (contigs) by NCBI staff. During the hackathon, a subset consisting of 2953 SRA data sets (approximately 55 million contigs) was selected, which were further filtered for a minimal length of 1 kb. This resulted in 4.2 million (Mio) contigs, which were aligned using BLAST against all known virus genomes, phylogenetically clustered and assigned metadata. Out of the 4.2 Mio contigs, 360,000 contigs were labeled with domains and an additional subset containing 4400 contigs was screened for virus or virus-like genes. The work yielded valuable insights into both SRA data and the cloud infrastructure required to support such efforts, revealing analysis bottlenecks and possible workarounds thereof. Mainly: (i) Conservative assemblies of SRA data improves initial analysis steps; (ii) existing bioinformatic software with weak multithreading/multicore support can be elevated by wrapper scripts to use all cores within a computing node; (iii) redesigning existing bioinformatic algorithms for a cloud infrastructure to facilitate its use for a wider audience; and (iv) a cloud infrastructure allows a diverse group of researchers to collaborate effectively. The scientific findings will be extended during a follow-up event. Here, we present the applied workflows, initial results, and lessons learned from the hackathon

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe