Point Source C-Band Mueller Matrices for the Green Bank Telescope

C-Band Mueller matrices for the Green Bank Telescope are presented here which enable on-sky Stokes parameters for point sources at the beam center to be determined. Standard calibrators, 3C138 and 3C286, were observed using the Spider program to steer the telescope across a broad range of Right Ascensions on both sides of the zenith transit. For this analysis, only the observations at the peak of the Spider pattern were used rather than the full sweep of the runs. Therefore, the results presented here only apply to point sources at the beam center. The Mueller matrices are shown to vary with frequency and with use of the Hi-Cal or Lo-Cal noise diodes, due to the relative calibration gain between the X and Y components of the feed. However, the relative calibration gain can be determined from observations of a source with known polarization. Correcting the data for the relative calibration gain prior to data analysis allows for use of a frequency independent Mueller matrix. This generic Mueller matrix is shown to provide reliable C-Band polarization measurements.Comment: Acceptance for publication in The Astronomical Journa

WISE J163940.83-684738.6: A Y Dwarf identified by Methane Imaging

We have used methane imaging techniques to identify the near-infrared counterpart of the bright WISE source WISEJ163940.83-684738.6. The large proper motion of this source (around 3.0arcsec/yr) has moved it, since its original WISE identification, very close to a much brighter background star -- it currently lies within 1.5" of the J=14.90+-0.04 star 2MASS16394085-6847446. Observations in good seeing conditions using methane sensitive filters in the near-infrared J-band with the FourStar instrument on the Magellan 6.5m Baade telescope, however, have enabled us to detect a near-infrared counterpart. We have defined a photometric system for use with the FourStar J2 and J3 filters, and this photometry indicates strong methane absorption, which unequivocally identifies it as the source of the WISE flux. Using these imaging observations we were then able to steer this object down the slit of the FIRE spectrograph on a night of 0.6" seeing, and so obtain near-infrared spectroscopy confirming a Y0-Y0.5 spectral type. This is in line with the object's near-infrared-to-WISE J3--W2 colour. Preliminary astrometry using both WISE and FourStar data indicates a distance of 5.0+-0.5pc and a substantial tangential velocity of 73+-8km/s. WISEJ163940.83-684738.6 is the brightest confirmed Y dwarf in the WISE W2 passband and its distance measurement places it amongst the lowest luminosity sources detected to date.Comment: Accepted for publication in The Astrophysical Journal, 20 September 201

A Radio Spectral Line Study of the 2-Jy IRAS-NVSS Sample: Part I

We present results from an on-going survey for the HI 21 cm line and the OH 18 cm lines in IR galaxies with the Arecibo 305 m Radio Telescope. The observations of 85 galaxies extracted from the 2 Jy IRAS-NVSS sample in the R.A. (B1950) range 20 h-00 h are reported in this paper. We detected the HI 21 cm line in 82 of these galaxies, with 18 being new detections, and the OH 18 cm lines in 7 galaxies, with 4 being new detections. In some cases, the HI spectra show the classic double-horned or single-peaked emission profiles. However, the majority exhibit distorted HI spectral features indicating that the galaxies are in interacting and/or merging systems. From these HI and OH observations, various properties of the sample are derived and reported.Comment: 38 pages, 7 figures, 9 tables. Accepted for publication in A

Increased utilization of total joint arthroplasty after Medicaid expansion

BACKGROUND: The expansion of state Medicaid programs under the U.S. Affordable Care Act has led to a dramatic increase in the number of Americans with health insurance coverage. Prior analyses of a limited number of states have suggested that greater utilization of total hip arthroplasty (THA) and total knee arthroplasty (TKA) should be expected after Medicaid expansion. The purpose of our study was to examine whether increased utilization of THA and TKA occurred across a broader range of states after Medicaid expansion. METHODS: We analyzed administrative data from the Healthcare Cost and Utilization Project from 9 states (Arkansas, Arizona, Colorado, Iowa, Massachusetts, Maryland, Nevada, New York, and Vermont) that expanded Medicaid in 2014 and 2 states that did not expand Medicaid (Florida and Missouri). We included patients who were 18 to 64 years of age and had a primary THA or TKA from 2012 to 2015 with Medicaid as the primary payer. Other payers (including dual-eligible Medicaid and Medicare beneficiaries) were excluded. We performed multivariable regression modeling with the number of Medicaid-insured THAs or TKAs as the dependent variable and the interaction between the state Medicaid expansion status and year as the main policy independent variable, with adjustment for community characteristics. RESULTS: Among all 11 states, there were 39,452 total joint arthroplasties (42% THA and 58% TKA) funded by Medicaid from 2012 to 2015. After adjusting for community characteristics, within expansion states, compared with 2013, THA and TKA increased 15% in 2014 (p \u3c 0.0001) and 23% in 2015 (p \u3c 0.0001) within expansion states. Within non-expansion states, compared with 2013, there were significant utilization decreases of 18% in 2014 (p \u3c 0.0001) and 11% in 2015 (p = 0.0002). CONCLUSIONS: Medicaid expansion was associated with significant increases in Medicaid-funded THA and TKA utilization in 9 states. As additional states consider expanding Medicaid programs and as alternative health reforms that increase insurance eligibility are debated, surgeons, administrators, and policymakers should prepare for a surge in the utilization of THA and TKA

Regular Solar Radio Imaging at Arecibo: Space Weather Perspective of Evolution of Active Regions

The sudden release of magnetic energy on the Sun drives powerful solar flares and coronal mass ejections. The key issue is the difficulty in predicting the occurrence time and location of strong solar eruptions, i.e., those leading to the high impact space weather disturbances at the near-Earth environment. Solar radio imaging helps identify the magnetic field characteristics of active regions susceptible to intense flares and energetic coronal mass ejections. Mapping of the Sun at X-band (8.1 -- 9.3 GHz) with the 12-m radio telescope at the Arecibo Observatory allows monitoring of the evolution of the brightness temperature of active regions in association with the development of magnetic complexity, which can lead to strong eruptions. For a better forecasting strategy in the future, such ground-based radio observations of high-spatial and temporal resolution, along with a full polarization capability, would have tremendous potential not only to understand the magnetic activity of solar eruptions, but also for revealing the particle acceleration mechanism and additional exciting science.Comment: 11 pages and 3 figures (White Paper Submitted to `Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033'

BIMA Millimeter-Wave Observations of the Core-Jet and Molecular Gas in the FR I Radio Galaxy NGC 3801

We present BIMA 3 mm observations of the radio continuum source and the molecular gas disk in the radio loud Fanaroff & Riley Type I (FR I) galaxy NGC 3801. We have detected a continuum source in the nucleus and determined that it has a flat millimeter-wave spectrum, suggesting that the emission is non-thermal and due to an AGN; the radio core is not evident in existing VLA observations. We also map the extended 3 mm emission from the previously known radio jets. In addition, we detect CO (1–0) emission associated with the dust disk observed in previous HST images. A velocity gradient is observed, indicating a two kpc radius rotating gas ring or disk oriented roughly perpendicular to the radio jets. The inferred molecular gas mass of the disk is M(H2) = 3×108M⊙, about 1% of the dynamical mass. We also find a 108 M⊙ molecular gas clump not associated with the gas disk. There is evidence that this gas is associated with a merger and is infalling. This suggests that FR I type activity is related to merger activity, as is thought to be the case for FR II type radio galaxies. We also find indications that one of the radio jets is entraining gas from the infalling molecular gas

Medial collateral ligament injuries of the knee: current treatment concepts

The medial collateral ligament is one of the most commonly injured ligaments of the knee. Most injuries result from a valgus force on the knee. The increased participation in football, ice hockey, and skiing has all contributed to the increased frequency of MCL injuries. Prophylactic knee bracing in contact sports may prevent injury; however, performance may suffer. The majority of patients who sustain an MCL injury will achieve their pre-injury activity level with non-operative treatment alone; however, those with combined ligamentous injuries may require acute operative care. Accurate characterization of each aspect of the injury will help to determine the optimum treatment plan

The ocean sampling day consortium

Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits

Helminth burden and ecological factors associated with alterations in wild host gastrointestinal microbiota

Infection by gastrointestinal helminths of humans, livestock and wild animals is common, but the impact of such endoparasites on wild hosts and their gut microbiota represents an important overlooked component of population dynamics. Wild host gut microbiota and endoparasites occupy the same physical niche spaces with both affecting host nutrition and health. However, associations between the two are poorly understood. Here we used the commonly parasitized European shag (Phalacrocorax aristotelis) as a model wild host. Forty live adults from the same colony were sampled. Endoscopy was employed to quantify helminth infection in situ. Microbiota from the significantly distinct proventriculus (site of infection), cloacal and faecal gastrointestinal tract microbiomes were characterised using 16S rRNA gene-targeted high-throughput sequencing. We found increasingly strong associations between helminth infection and microbiota composition progressing away from the site of infection, observing a pronounced dysbiosis in microbiota when samples were partitioned into high- and low-burden groups. We posit this dysbiosis is predominately explained by helminths inducing an anti-inflammatory environment in the proventriculus, diverting host immune responses away from themselves. This study, within live wild animals, provides a vital foundation to better understand the mechanisms that underpin the three-way relationship between helminths, microbiota and hosts