Evidence for extended, obscured starbursts in submm galaxies

We compare high-resolution optical and radio imaging of 12 luminous submm galaxies at z=2.2+/-0.2 observed with HST and the MERLIN and VLA at comparable spatial resolution, 0.3" (2kpc). The radio emission traces the likely far-infrared morphology of these dusty, luminous galaxies. In ~30% of the sample the radio appears unresolved, suggesting that the emission is compact: either an obscured AGN or nuclear starburst. However, in the majority, ~70% (8/12), the radio emission is resolved by MERLIN/VLA on scales of ~1" (10 kpc). For these galaxies the radio morphologies are broadly similar to their restframe UV emission seen by HST. We discuss the probable mechanisms for the extended emission and conclude that their luminous radio and submm emission arises from a large, spatially-extended starburst. The median SFRs are 1700Mo/yr occuring within a ~40kpc^2 region, giving a star formation density of 45Mo/yr/kpc^2. Such vigorous and extended starbursts appear to be uniquely associated with the submm population. A more detailed comparison of the distribution of UV and radio emission shows that the broad similarities on large scales are not carried through to smaller scales, where there is rarely a one-to-one correspondance. We interpret this as resulting from highly structured internal obscuration, suggesting that the vigorous activity is producing wind-blown channels through the obscuration in these galaxies. If correct this underlines the difficulty of using UV morphologies to understand structural properties of this population and also may explain the surprising frequency of Ly-alpha emission in their spectra. [Abridged]Comment: 7 pages, 3 figure

Characterization of the Interaction between the Herpes Simplex Virus Type I Fc Receptor and Immunoglobulin G

Herpes simplex virus type I (HSV-1) virions and HSV-1-infected cells bind to human immunoglobulin G (hIgG) via its Fc region. A complex of two surface glycoproteins encoded by HSV-1, gE and gI, is responsible for Fc binding. We have co-expressed soluble truncated forms of gE and gI in Chinese hamster ovary cells. Soluble gE-gI complexes can be purified from transfected cell supernatants using a purification scheme that is based upon the Fc receptor function of gE-gI. Using gel filtration and analytical ultracentrifugation, we determined that soluble gE-gI is a heterodimer composed of one molecule of gE and one molecule of gI and that gE-gI heterodimers bind hIgG with a 1:1 stoichiometry. Biosensor-based studies of the binding of wild type or mutant IgG proteins to soluble gE-gI indicate that histidine 435 at the CH2-CH3 domain interface of IgG is a critical residue for IgG binding to gE-gI. We observe many similarities between the characteristics of IgG binding by gE-gI and by rheumatoid factors and bacterial Fc receptors such as Staphylococcus aureus protein A. These observations support a model for the origin of some rheumatoid factors, in which they represent anti-idiotypic antibodies directed against antibodies to bacterial and viral Fc receptors

Cyanobacterial Abundance and Microcystin Profiles in Two Southern British Lakes: The Importance of Abiotic and Biotic Interactions.

Freshwater cyanobacteria blooms represent a risk to ecological and human health through induction of anoxia and release of potent toxins; both conditions require water management to mitigate risks. Many cyanobacteria taxa may produce microcystins, a group of toxic cyclic heptapeptides. Understanding the relationships between the abiotic drivers of microcystins and their occurrence would assist in the implementation of targeted, cost-effective solutions to maintain safe drinking and recreational waters. Cyanobacteria and microcystins were measured by flow cytometry and liquid chromatography coupled to tandem mass spectrometry in two interconnected reservoirs varying in age and management regimes, in southern Britain over a 12-month period. Microcystins were detected in both reservoirs, with significantly higher concentrations in the southern lake (maximum concentration >7 µg L-1). Elevated microcystin concentrations were not positively correlated with numbers of cyanobacterial cells, but multiple linear regression analysis suggested temperature and dissolved oxygen explained a significant amount of the variability in microcystin across both reservoirs. The presence of a managed fishery in one lake was associated with decreased microcystin levels, suggestive of top down control on cyanobacterial populations. This study supports the need to develop inclusive, multifactor holistic water management strategies to control cyanobacterial risks in freshwater bodies

Integrated survey methodologies provide process-driven framework for marine renewable energy environmental impact assessment

The authors would like to the thank the FLOWBEC-4D development team as well as the observers and scientists of the MRV Scotia 2016 (Marianna Chimienti, Helen Wade, Laura Williamson, Ewan Edwards, and Eric Armstrong) and 2018 (Tom Evans, Sarah Fenn, Ross Culloch, David Hunter and Adrian Tait) surveys. Additionally, thanks go to Paul Fernandes (University of Aberdeen) for guidance and reviewing of the acoustic fisheries analysis undertaken here.Peer reviewe

Local lung hypoxia determines epithelial fate decisions during alveolar regeneration.

After influenza infection, lineage-negative epithelial progenitors (LNEPs) exhibit a binary response to reconstitute epithelial barriers: activating a Notch-dependent ΔNp63/cytokeratin 5 (Krt5) remodelling program or differentiating into alveolar type II cells (AEC2s). Here we show that local lung hypoxia, through hypoxia-inducible factor (HIF1α), drives Notch signalling and Krt5pos basal-like cell expansion. Single-cell transcriptional profiling of human AEC2s from fibrotic lungs revealed a hypoxic subpopulation with activated Notch, suppressed surfactant protein C (SPC), and transdifferentiation toward a Krt5pos basal-like state. Activated murine Krt5pos LNEPs and diseased human AEC2s upregulate strikingly similar core pathways underlying migration and squamous metaplasia. While robust, HIF1α-driven metaplasia is ultimately inferior to AEC2 reconstitution in restoring normal lung function. HIF1α deletion or enhanced Wnt/β-catenin activity in Sox2pos LNEPs blocks Notch and Krt5 activation, instead promoting rapid AEC2 differentiation and migration and improving the quality of alveolar repair

Exploiting eco-physiological niche to facilitate the separation of the freshwater cyanobacteria Microcystis sp. and Synechococcus sp.

In a novel approach to separate the co-occurring freshwater cyanobacteria Microcystis and Synechoccous, published ecological characteristics are used to manipulate temperature and nutrient concentrations to successfully establish a unialgal Microcystis strain. The simple protocol has implications for future cyanobacterial culturing approaches and the establishment of new cyanobacteria strains

Tidal streams, fish and seabirds : understanding the linkages between mobile predators, prey, and hydrodynamics

Fundings: Natural Environment Research Council (GrantNumber(s): VertIBase project [NE/N01765X/1]) Department for Business, Energy and Industrial Strategy, UK Government (GrantNumber(s): Offshore Energy Strategic Environmental Assessment) ACKNOWLEDGMENTS We gratefully acknowledge the support of the crew and scientists of the MRV Scotia 2016 (0916S) and 2018 (1018S) cruises: Marianna Chimienti, Helen Wade, Laura Williamson, Ewan Edwards, Ross Culloch, Tom Evans, Sarah Fenn, David Hunter, Eric Armstrong, and Adrian Tait. This work was supported by the NERC VertIBase Project [NE/N01765X/1] and the UK Department for Business, Energy and Industrial Strategy’s Offshore Energy Strategic Environmental Assessment Programme.Peer reviewedPublisher PD

Energetic Galaxy-Wide Outflows in High-Redshift Ultraluminous Infrared Galaxies Hosting AGN Activity

We present integral field spectroscopy observations, covering the [O III]4959,5007 emission-line doublet of eight high-redshift (z=1.4-3.4) ultra-luminous infrared galaxies (ULIRGs) that host Active Galactic Nuclei (AGN) activity, including known sub-millimetre luminous galaxies (SMGs). The targets have moderate radio luminosities that are typical of high-redshift ULIRGs (L(1.4GHz)=10^(24)-10^(25)W/Hz) and therefore are not radio-loud AGN. We de-couple kinematic components due to the galaxy dynamics and mergers from those due to outflows. We find evidence in the four most luminous systems (L([O III])\u3e~10^(43)erg/s) for the signatures of large-scale energetic outflows: extremely broad [O III] emission (FWHM ~ 700-1400km/s) across ~4-15kpc, with high velocity offsets from the systemic redshifts (up to ~850km/s). The four less luminous systems have lower quality data displaying weaker evidence for spatially extended outflows. We estimate that these outflows are potentially depositing energy into their host galaxies at considerable rates (~10^(43)-10^(45)erg/s); however, due to the lack of constraints on the density of the outflowing material and the structure of the outflow, these estimates should be taken as illustrative only. Based on the measured maximum velocities (v(max)~400-1400km/s) the outflows observed are likely to unbind some fraction of the gas from their host galaxies, but are unlikely to completely remove gas from the galaxy haloes. By using a combination of energetic arguments and a comparison to ULIRGs without clear evidence for AGN activity, we show that the AGN activity could be the dominant power source for driving all of the observed outflows, although star formation may also play a significant role in some of the sources

Ginzburg-Landau vortex dynamics with pinning and strong applied currents

We study a mixed heat and Schr\"odinger Ginzburg-Landau evolution equation on a bounded two-dimensional domain with an electric current applied on the boundary and a pinning potential term. This is meant to model a superconductor subjected to an applied electric current and electromagnetic field and containing impurities. Such a current is expected to set the vortices in motion, while the pinning term drives them toward minima of the pinning potential and "pins" them there. We derive the limiting dynamics of a finite number of vortices in the limit of a large Ginzburg-Landau parameter, or \ep \to 0, when the intensity of the electric current and applied magnetic field on the boundary scale like \lep. We show that the limiting velocity of the vortices is the sum of a Lorentz force, due to the current, and a pinning force. We state an analogous result for a model Ginzburg-Landau equation without magnetic field but with forcing terms. Our proof provides a unified approach to various proofs of dynamics of Ginzburg-Landau vortices.Comment: 48 pages; v2: minor errors and typos correcte