Astrophysics of Reference Frame Tie Objects

The Astrophysics of Reference Frame Tie Objects Key Science program will investigate the underlying physics of SIM grid objects. Extragalactic objects in the SIM grid will be used to tie the SIM reference frame to the quasi-inertial reference frame defined by extragalactic objects and to remove any residual frame rotation with respect to the extragalactic frame. The current realization of the extragalactic frame is the International Celestial Reference Frame (ICRF). The ICRF is defined by the radio positions of 212 extragalactic objects and is the IAU sanctioned fundamental astronomical reference frame. This key project will advance our knowledge of the physics of the objects which will make up the SIM grid, such as quasars and chromospherically active stars, and relates directly to the stability of the SIM reference frame. The following questions concerning the physics of reference frame tie objects will be investigated

A Deep Photometric Look at Two of Andromeda's Dwarf Spheroidals: X and XVII

We use deep wide-field photometry from the Large Binocular Camera to study the stellar and structural properties of the recently discovered Andromeda X and Andromeda XVII (And X and And XVII) dwarf galaxies. Using the mean apparent magnitude of the horizontal branch (HB), we derive distances of 621 +- 20 kpc to And X and 734+- 23 kpc to And XVII, closer by >60 kpc than the previous estimates which were based on red giant branch (RGB) observations. Thus our results warrant against the use of the RGB tip method for determining distances to systems with sparsely populated RGBs, and show how crucial HB observations are in obtaining accurate distances in systems such as these. We find that And X is a relatively faint (MV = -7.36), highly elongated (e = 0.48) system at a distance of 174 +- 62 kpc from Andromeda. And XVII is brighter (MV = -8.61) with an M31-centric distance of 73 kpc which makes it one of the closest satellites to Andromeda. Both galaxies are metal-poor: we derive =-2.2 for And X, while And XVII shows = -2.0, consistent with the relation of higher luminosity dwarfs being more metal- rich. Additionally, both galaxies show considerable intrinsic spreads in metallicity (0.2 and 0.3 dex for And X and And XVII respectively), consistent with multiple stellar populations.Comment: 8 pages, 6 figure

Fig rust caused by Phakopsora nishidana in South Africa

Fig rust, caused by Cerotelium fici, was first recorded in South Africa in 1927. Recent observations have revealed high incidence of rust and untimely defoliation of fig trees (Ficus carica) in residential gardens and commercial orchards. Using phylogenetic analysis, the causal organism of a fig rust isolate (PREM63073) collected in 2020 was confirmed as Phakopsora nishidana. Inoculation and microscope studies showed that mulberry plants were immune to P. nishidana isolate PREM63073. Infection of fig leaves occurred through stomata on the abaxial leaf surfaces. Very long germ tubes were observed for P. nishidana, often with no clear contact with the leaf surfaces and an apparent lack of directional growth towards stomata. Inoculated plants from 15 fig cultivars varied in their severity of leaf infection, whereas fruit of the cultivar Kadota developed reddish-brown blemishes without sporulation. Currently, C. fici and P. nishidana are recognised as occurring on F. carica in South Africa. This suggests a need to resolve the worldwide distribution and identity of the rust species involved

Astrometry and radial velocities of the planet host M dwarf GJ 317: new trigonometric distance, metallicity and upper limit to the mass of GJ 317b

We have obtained precision astrometry of the planet hosting M dwarf GJ 317 in the framework of the Carnegie Astrometric Planet Search project. The new astrometric measurements give a distance determination of 15.3 pc, 65% further than previous estimates. The resulting absolute magnitudes suggest it is metal rich and more massive than previously assumed. This result strengthens the correlation between high metallicity and the presence of gas giants around low mass stars. At 15.3 pc, the minimal astrometric amplitude for planet candidate GJ 317b is 0.3 milliarcseconds (edge-on orbit), just below our astrometric sensitivity. However, given the relatively large number of observations and good astrometric precision, a Bayesian Monte Carlo Markov Chain analysis indicates that the mass of planet b has to be smaller than twice the minimum mass with a 99% confidence level, with a most likely value of 2.5 Mjup. Additional RV measurements obtained with Keck by the Lick-Carnegie Planet search program confirm the presence of an additional very long period planet candidate, with a period of 20 years or more. Even though such an object will imprint a large astrometric wobble on the star, its curvature is yet not evident in the astrometry. Given high metallicity, and the trend indicating that multiple systems are rich in low mass companions, this system is likely to host additional low mass planets in its habitable zone that can be readily detected with state-of-the-art optical and near infrared RV measurements.Comment: 20 pages of text, 9 Figures, 8 tables. Accepted in ApJ (in press

The Seventh Data Release of the Sloan Digital Sky Survey

This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor correction

A Comparative Approach Linking Molecular Dynamics of Altered Peptide Ligands and MHC with In Vivo Immune Responses

The recognition of peptide in the context of MHC by T lymphocytes is a critical step in the initiation of an adaptive immune response. However, the molecular nature of the interaction between peptide and MHC and how it influences T cell responsiveness is not fully understood.We analyzed the immunological consequences of the interaction of MHC class II (I-Au) restricted 11-mer peptides of myelin basic protein with amino acid substitutions at position 4. These mutant peptides differ in MHC binding affinity, CD4+ T cell priming, and alter the severity of peptide-induced experimental allergic encephalomyelitis. Using molecular dynamics, a computational method of quantifying intrinsic movements of proteins at high resolution, we investigated conformational changes in MHC upon peptide binding. We found that irrespective of peptide binding affinity, MHC deformation appears to influence costimulation, which then leads to effective T cell priming and disease induction. Although this study compares in vivo and molecular dynamics results for three altered peptide ligands, further investigation with similar complexes is essential to determine whether spatial rearrangement of peptide-MHC and costimulatory complexes is an additional level of T cell regulation

Mesothelioma and Radical Surgery 2 (MARS 2): protocol for a multicentre randomised trial comparing (extended) pleurectomy decortication versus no (extended) pleurectomy decortication for patients with malignant pleural mesothelioma.

INTRODUCTION: Mesothelioma remains a lethal cancer. To date, systemic therapy with pemetrexed and a platinum drug remains the only licensed standard of care. As the median survival for patients with mesothelioma is 12.1 months, surgery is an important consideration to improve survival and/or quality of life. Currently, only two surgical trials have been performed which found that neither extensive (extra-pleural pneumonectomy) or limited (partial pleurectomy) surgery improved survival (although there was some evidence of improved quality of life). Therefore, clinicians are now looking to evaluate pleurectomy decortication, the only radical treatment option left. METHODS AND ANALYSIS: The MARS 2 study is a UK multicentre open parallel group randomised controlled trial comparing the effectiveness and cost-effectiveness of surgery-(extended) pleurectomy decortication-versus no surgery for the treatment of pleural mesothelioma. The study will test the hypothesis that surgery and chemotherapy is superior to chemotherapy alone with respect to overall survival. Secondary outcomes include health-related quality of life, progression-free survival, measures of safety (adverse events) and resource use to 2 years. The QuinteT Recruitment Intervention is integrated into the trial to optimise recruitment. ETHICS AND DISSEMINATION: Research ethics approval was granted by London - Camberwell St. Giles Research Ethics Committee (reference 13/LO/1481) on 7 November 2013. We will submit the results for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBERS: ISRCTN-ISRCTN44351742 and ClinicalTrials.gov-NCT02040272

The genera of fungi-fixing the application of the type species of generic names-G 2: Allantophomopsis, Latorua, Macrodiplodiopsis, Macrohilum, Milospium, Protostegia, Pyricularia, Robillarda, Rotula, Septoriella, Torula, and Wojnowicia

The present paper represents the second contribution in the Genera of Fungi series, linking type species of fungal genera to their morphology and DNA sequence data, and where possible, ecology. This paper focuses on 12 genera of microfungi, 11 of which the type species are neo- or epitypified here: Allantophomopsis (A. cytisporea, Phacidiaceae, Phacidiales, Leotiomycetes), Latorua gen. nov. (Latorua caligans, Latoruaceae, Pleosporales, Dothideomycetes), Macrodiplodiopsis (M. desmazieri, Macrodiplodiopsidaceae, Pleosporales, Dothideomycetes), Macrohilum (M. eucalypti, Macrohilaceae, Diaporthales, Sordariomycetes), Milospium (M. graphideorum, incertae sedis, Pezizomycotina), Protostegia (P. eucleae, Mycosphaerellaceae, Capnodiales, Dothideomycetes), Pyricularia (P. grisea, Pyriculariaceae, Magnaporthales, Sordariomycetes), Robillarda (R. sessilis, Robillardaceae, Xylariales, Sordariomycetes), Rutola (R. graminis, incertae sedis, Pleosporales, Dothideomycetes), Septoriella (S. phragmitis, Phaeosphaeriaceae, Pleosporales, Dothideomycetes), Torula (T. herbarum, Torulaceae, Pleosporales, Dothideomycetes) and Wojnowicia (syn. of Septoriella, S. hirta, Phaeosphaeriaceae, Pleosporales, Dothideomycetes). Novel species include Latorua grootfonteinensis, Robillarda africana, R. roystoneae, R. terrae, Torula ficus, T. hollandica, and T. masonii spp. nov., and three new families: Macrodiplodiopsisceae, Macrohilaceae, and Robillardaceae. Authors interested in contributing accounts of individual genera to larger multi-authored papers to be published in IMA Fungus, should contact the associate editors listed for the major groups of fungi on the List of Protected Generic Names for FungiThe Austrian Science Fund (FWF; project P25870-B16)http://www.generaoffungi.orgam201