Gull plumages are, and are not, what they appear to human vision

Clear correlations between human and bird visual assessments of color have been documented, and are often assumed, despite fundamental differences in human and avian visual physiology and morphology. Analyses of plumage colors with avian perceptual models have shown widespread hidden inter-sexual and inter-specific color variation among passerines perceived as monochromatic to humans, highlighting the uncertainty of human vision to predict potentially relevant variation in color. Herein, we use reflectance data from 13 Larus gull species as an exemplar data set to study concordance between human vision and avian visual modeling of feather colors near, or below, the human threshold for discrimination. We found little evidence among gulls for sexual dichromatism hidden from human vision, but did find inter-specific color variation among gulls that is not seen by humans. Neither of these results were predictable a priori, and we reassert that reflectance measurements of actual feather colors, analyzed with avian relevant visual models, represent best practice when studying bird coloration

Fertilization in C. elegans requires an intact C-terminal RING finger in sperm protein SPE-42

<p>Abstract</p> <p>Background</p> <p>The <it>C. elegans </it>sperm protein SPE-42, a membrane protein of unknown structure and molecular function, is required for fertilization. Sperm from worms with <it>spe-42 </it>mutations appear normal but are unable to fertilize eggs. Sequence analysis revealed the presence of 8 conserved cysteine residues in the C-terminal cytoplasmic domain of this protein suggesting these residues form a zinc-coordinating RING finger structure.</p> <p>Results</p> <p>We made an <it>in silico </it>structural model of the SPE-42 RING finger domain based on primary sequence analysis and previously reported RING structures. To test the model, we created <it>spe-42 </it>transgenes coding for mutations in each of the 8 cysteine residues predicted to coordinate Zn⁺⁺ions in the RING finger motif. Transgenes were crossed into a <it>spe-42 </it>null background and protein function was measured by counting progeny. We found that all 8 cysteines are required for protein function. We also showed that sequence differences between the C-terminal 29 and 30 amino acids in <it>C. elegans </it>and <it>C. briggsae </it>SPE-42 following the RING finger domain are not responsible for the failure of the <it>C. briggsae </it>SPE-42 homolog to rescue <it>C. elegans spe-42 </it>mutants.</p> <p>Conclusions</p> <p>The results suggest that a <it>bona fide </it>RING domain is present at the C-terminus of the SPE-42 protein and that this motif is required for sperm-egg interactions during <it>C. elegans </it>fertilization. Our structural model of the RING domain provides a starting point for further structure-function analysis of this critical region of the protein. The C-terminal domain swap experiment suggests that the incompatibility between the <it>C. elegans </it>and <it>C. briggsae </it>SPE-42 proteins is caused by small amino acid differences outside the C-terminal domain.</p

It's a dry heat: Quantifying effects of increasing atmospheric moisture demand on native Oklahoma trees

Anthropogenic climate change is predicted to alter precipitation frequency and intensity across Oklahoma in the coming decades, leading to an increase in the frequency, intensity, and duration of extreme events such as soil drought. Concurrently, temperature is predicted to continue rising, causing an ever-increasing atmospheric demand from plants. While the effect of soil droughts has been extensively studied in recent years, the impact of ever-increasing atmospheric droughts on trees is less characterized. Trees regulate photosynthesis though the interactive effects of availability of soil water (supply) and atmospheric demand for water (Vapor Pressure Deficit, VPD). Using recent innovations, and a novel experimental design, we set out to test gas exchange response for three native Oklahoma tree species to varying levels of VPD, with the hypothesis that drought adapted species would be less sensitive to increasing VPD. Two of the species, Quercus stellata and Quercus marilandica, often occur on unfavorable dry sites, while Cercis canadensis is found in riparian areas and wet forest interiors. We exposed six trees of each species to a range of VPDs, between 1kPa and 3kPa, at a constant temperature under well-watered conditions. We measured rates of carbon assimilation and stomatal conductance at five intervals across our VPD measurement range using a LI-COR LI-6800 infrared gas analyzer. Relative rates of carbon assimilation and stomatal conductance decreased as VPD increased across taxa. However, C. canadensis decreased carbon assimilation much quicker than the Quercus species as VPD increased in support of our hypothesis. Our results provide a preliminary understanding of photosynthetic response across a range of VPDs for deciduous forest trees in Oklahoma. Additionally, our methods provide a clear and repeatable way forward, as we aim to disentangle the effects of soil and atmospheric drought on photosynthetic rates in future experiments.Lew Wentz FoundationPlant Biology, Ecology and Evolutio

The NAtional randomised controlled Trial of Tonsillectomy IN Adults (NATTINA) : a clinical and cost-effectiveness study: study protocol for a randomised control trial

This project is funded by the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme (project number 12/146/06).BACKGROUND: The role of tonsillectomy in the management of adult tonsillitis remains uncertain and UK regional variation in tonsillectomy rates persists. Patients, doctors and health policy makers wish to know the costs and benefits of tonsillectomy against conservative management and whether therapy can be better targeted to maximise benefits and minimise risks of surgery, hence maximising cost-effective use of resources. NATTINA incorporates the first attempt to map current NHS referral criteria against other metrics of tonsil disease severity. METHODS/DESIGN: A UK multi-centre, randomised, controlled trial for adults with recurrent tonsillitis to compare the clinical and cost-effectiveness of tonsillectomy versus conservative management. An initial feasibility study comprises qualitative interviews to investigate the practicality of the protocol, including willingness to randomise and be randomised. Approximately 20 otolaryngology staff, 10 GPs and 15 ENT patients will be recruited over 5 months in all 9 proposed main trial participating sites. A 6-month internal pilot will then recruit 72 patients across 6 of the 9 sites. Participants will be adults with recurrent acute tonsillitis referred by a GP to secondary care. Randomisation between tonsillectomy and conservative management will be according to a blocked allocation method in a 1:1 ratio stratified by centre and baseline disease severity. If the pilot is successful, the main trial will recruit a further 528 patients over 18 months in all 9 participating sites. All participants will be followed up for a total of 24 months, throughout which both primary and secondary outcome data will be collected. The primary outcome is the number of sore throat days experienced over the 24-month follow-up. The pilot and main trials include an embedded qualitative process evaluation. DISCUSSION: NATTINA is designed to evaluate the relative effectiveness and efficiency of tonsillectomy versus conservative management in patients with recurrent sore throat who are eligible for surgery. Most adult tonsil disease and surgery has an impact on economically active age groups, with individual and societal costs through loss of earnings and productivity. Avoidance of unnecessary operations and prioritisation of those individuals likely to gain most from tonsillectomy would reduce costs to the NHS and society. TRIAL REGISTRATION: ISRCTN55284102, Date of Registration: 4 August 2014.Publisher PDFPeer reviewe

Electromagnetic and Gravitational Scattering at Planckian Energies

The scattering of pointlike particles at very large center of mass energies and fixed low momentum transfers, occurring due to both their electromagnetic and gravitational interactions is re-examined in the particular case when one of the particles carries magnetic charge. At Planckian center-of-mass energies, when gravitational dominance is normally expected, the presence of magnetic charge is shown to produce dramatic modifications to the scattering cross section as well as to the holomorphic structure of the scattering amplitude.Comment: 33 pages, Revtex file, no figs; a footnote and two references adde

SOFIA/FORCAST and Spitzer/IRAC Imaging of the Ultra Compact H II Region W3(OH) and Associated Protostars in W3

We present infrared observations of the ultra-compact H II region W3(OH) made by the FORCAST instrument aboard SOFIA and by Spitzer/IRAC. We contribute new wavelength data to the spectral energy distribution, which constrains the optical depth, grain size distribution, and temperature gradient of the dusty shell surrounding the H II region. We model the dust component as a spherical shell containing an inner cavity with radius ~ 600 AU, irradiated by a central star of type O9 and temperature ~ 31,000 K. The total luminosity of this system is 71,000 L_solar. An observed excess of 2.2 - 4.5 microns emission in the SED can be explained by our viewing a cavity opening or clumpiness in the shell structure whereby radiation from the warm interior of the shell can escape. We claim to detect the nearby water maser source W3 (H2O) at 31.4 and 37.1 microns using beam deconvolution of the FORCAST images. We constrain the flux densities of this object at 19.7 - 37.1 microns. Additionally, we present in situ observations of four young stellar and protostellar objects in the SOFIA field, presumably associated with the W3 molecular cloud. Results from the model SED fitting tool of Robitaille et al. (2006, 2007} suggest that two objects (2MASS J02270352+6152357 and 2MASS J02270824+6152281) are intermediate-luminosity (~ 236 - 432 L_solar) protostars; one object (2MASS J02270887+6152344) is either a high-mass protostar with luminosity 3000 L_solar or a less massive young star with a substantial circumstellar disk but depleted envelope; and one object (2MASS J02270743+6152281) is an intermediate-luminosity (~ 768 L_solar) protostar nearing the end of its envelope accretion phase or a young star surrounded by a circumstellar disk with no appreciable circumstellar envelope.Comment: 12 pages, 8 figures, 2 tables, accepted by Ap

A new fireworm (Amphinomidae) from the Cretaceous of Lebanon identified from three-dimensionally preserved myoanatomy

© 2015 Parry et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article