1,552 research outputs found
Chemical Abundances in Field Red Giants from High-Resolution H-Band Spectra using the APOGEE Spectral Linelist
High-resolution H-band spectra of five bright field K, M, and MS giants,
obtained from the archives of the Kitt Peak National Observatory (KPNO) Fourier
Transform Spectrometer (FTS), are analyzed to determine chemical abundances of
16 elements. The abundances were derived via spectrum synthesis using the
detailed linelist prepared for the SDSS III Apache Point Galactic Evolution
Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic
survey to derive detailed chemical abundance distributions and precise radial
velocities for 100,000 red giants sampling all Galactic stellar populations.
Measured chemical abundances include the cosmochemically important isotopes
12C, 13C, 14N, and 16O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co,
Ni, and Cu. A comparison of the abundances derived here with published values
for these stars reveals consistent results to ~0.1 dex. The APOGEE spectral
region and linelist is, thus, well-suited for probing both Galactic chemical
evolution, as well as internal nucleosynthesis and mixing in populations of red
giants using high-resolution spectroscopy.Comment: Accepted for publication in The Astrophysical Journal. 42 pages, 12
figure
the SDSS-III APOGEE Spectral Line List for H-Band Spectroscopy
We present the H-band spectral line lists adopted by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). The APOGEE line lists comprise astrophysical, theoretical, and laboratory sources from the literature, as well as newly evaluated astrophysical oscillator strengths and damping parameters. We discuss the construction of the APOGEE line list, which is one of the critical inputs for the APOGEE Stellar Parameters and Chemical Abundances Pipeline, and present three different versions that have been used at various stages of the project. The methodology for the newly calculated astrophysical line lists is reviewed. The largest of these three line lists contains 134,457 molecular and atomic transitions. In addition to the format adopted to store the data, the line lists are available in MOOG, Synspec, and Turbospectrum formats. The limitations of the line lists along with guidance for its use on different spectral types are discussed. We also present a list of H-band spectral features that are either poorly represented or completely missing in our line list. This list is based on the average of a large number of spectral fit residuals for APOGEE observations spanning a wide range of stellar parameters.Alfred P. Sloan FoundationNational Science FoundationU.S. Department of Energy Office of ScienceJanos Bolyai Research Scholarship of the Hungarian Academy of SciencesSpanish Ministry of Economy and Competitiveness AYA-2011-27754, AYA-2014-58082-PRSF 14-50-00043McDonald Observator
Extinction Maps Toward The Milky Way Bulge: Two-Dimensional And Three-Dimensional Tests With APOGEE
Galactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these maps, tests of their accuracy and systematics have been limited. Our goal is to assess a variety of photometric stellar extinction estimates, including both two-dimensional and three-dimensional extinction maps, using independent extinction measures based on a large spectroscopic sample of stars toward the Milky Way bulge. We employ stellar atmospheric parameters derived from high-resolution H-band Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra, combined with theoretical stellar isochrones, to calculate line-of-sight extinction and distances for a sample of more than 2400 giants toward the Milky Way bulge. We compare these extinction values to those predicted by individual near-IR and near+mid-IR stellar colors, two-dimensional bulge extinction maps, and three-dimensional extinction maps. The long baseline, near+mid-IR stellar colors are, on average, the most accurate predictors of the APOGEE extinction estimates, and the two-dimensional and three-dimensional extinction maps derived from different stellar populations along different sightlines show varying degrees of reliability. We present the results of all of the comparisons and discuss reasons for the observed discrepancies. We also demonstrate how the particular stellar atmospheric models adopted can have a strong impact on this type of analysis, and discuss related caveats.NSF Astronomy & Astrophysics Postdoctoral Fellowship AST-1203017Physics Frontier Center/Joint Institute for Nuclear Astrophysics (JINA) PHY 08-22648U.S. National Science FoundationAlfred P. Sloan FoundationParticipating InstitutionsU.S. Department of Energy Office of Science ANR-12-BS05-0015-01Astronom
Presoaking ACL grafts in vancomycin decreases the frequency of postoperative septic arthritis. A cohort study of 29,659 patients, systematic review, and meta-analysis from the SANTI Study Group
Background: Presoaking anterior cruciate ligament (ACL) grafts in vancomycin has been reported to reduce the occurrence of septic arthritis (SA). However, strong recommendations for its universal use have been precluded by concerns regarding the fragility of previous meta-analyses.
Purpose: The primary objective was to investigate whether presoaking ACL grafts in vancomycin was associated with a reduction in the rate of SA in a large series of patients. The secondary objective was to perform an updated systematic review and meta- analysis to determine the efficacy of vancomycin in reducing the rate of SA.
Study Design: Cohort study and systematic review; Level of evidence, 3.
Methods: A retrospective analysis of patients who underwent primary ACL reconstruction (ACLR) at our institution was undertaken. Rates of postoperative SA were determined and analyzed according to whether patients had received grafts presoaked in vanco- mycin. A systematic review of the literature and meta-analysis was performed. Odds ratios (ORs) for the risk of SA were calculated according to the inverse variance approach. Results were presented using forest plots, funnel plots, and the fragility index.
Results: A total of 5300 patients underwent primary ACLR during the study period. The rate of SA was 0.34% (11/3228) in the control group and 0.05% (1/2072) in the presoaked group. There was a 5-fold greater risk of SA in patients who did not receive grafts presoaked in vancomycin (OR, 5.13 [95% CI, 1.16-48.30]; P 1â4 .04). Overall, 11 studies were included in the systematic review (29,659 ACLR procedures). The meta-analysis demonstrated a significantly greater risk of SA in those patients who did not receive grafts presoaked in vancomycin (OR, 14.39 [95% CI, 5.90-35.10]; fragility index 1â4 23). This finding held true for the subpopulation receiving hamstring tendon grafts (fragility index 1â4 16), but only a trend was demonstrated for boneâpatellar ten- donâbone grafts.
Conclusion: The meta-analysis demonstrated that presoaking ACL grafts in vancomycin was associated with significant reductions in the rates of SA when all graft types were analyzed together. This finding held true specifically for hamstring tendon autografts. The fragility index of these findings allows for a strong recommendation for the universal use of vancomycin presoaking. However, it should be noted that only a trend toward reduced SA rates was demonstrated with presoaking boneâpatellar tendonâ bone autografts in vancomycin
Evangelical Visitor- October 2, 1911. Vol. XXV. No. 20.
Evangelical Visitor published in Harrisburg, Pa., for the exposition of true, practical piety and devoted to the spread of evangelical truths and the unity of the church. Published in the interest of the church of the Brethren in Christ on October 2, 1911. Vol. XXV. No. 20
New H-band Stellar Spectral Libraries for the SDSS-III/APOGEE survey
The Sloan Digital Sky Survey--III (SDSS--III) Apache Point Observatory
Galactic Evolution Experiment (APOGEE) has obtained high resolution (R
22,500), high signal-to-noise ratio ( 100) spectra in the Hband
(1.51.7 m) for about 146,000 stars in the Milky Way galaxy. We
have computed spectral libraries with effective temperature ()
ranging from 3500 to 8000 K for the automated chemical analy\-sis of the survey
data. The libraries, used to derive stellar parameters and abundances from the
APOGEE spectra in the SDSS--III data release 12 (DR12), are based on ATLAS9
model atmospheres and the ASST spectral synthesis code. We present a
second set of libraries based on MARCS model atmospheres and the spectral
synthesis code Turbospectrum. The ATLAS9/ASST ( =
35008000 K) and MARCS/Turbospectrum ( = 35005500 K) grids
cover a wide range of metallicity (2.5 [M/H] 0.5 dex),
surface gravity (0 log 5 dex), microturbulence (0.5
8 km~s), carbon (1 [C/M] 1 dex),
nitrogen (1 [N/M] 1 dex), and -element (1
[/M] 1 dex) variations, having thus seven dimensions. We
compare the ATLAS9/ASST and MARCS/Turbospectrum libraries and apply
both of them to the analysis of the observed Hband spectra of the Sun and
the K2 giant Arcturus, as well as to a selected sample of well-known giant
stars observed at very high-resolution. The new APOGEE libraries are publicly
available and can be employed for chemical studies in the Hband using other
high-resolution spectrographs.Comment: 45 pages, 11 figures; accepted for publication in the Astronomical
Journa
Adult Hypophosphatasia : a disease where the clinical complications could be avoided by careful evaluation of patients
This is the author accepted manuscript. The final version is available from Springer via the DOI in this recordOsteoporosis Conference 2018 Birmingham, UK 2 â 4 December 201
Socio-economic status and the risk of developing hand, hip or knee osteoarthritis: a region-wide ecological study
SummaryObjectiveTo determine the association between socio-economic status (SES) and risk of hand, hip or knee osteoarthritis (OA) at a population level.DesignRetrospective ecological study using the System for the Development of Research in Primary Care (SIDIAP) database (primary care anonymized records for >5 million people in Catalonia (Spain)). Urban residents >15 years old (2009â2012) were eligible. Outcomes: Validated area-based SES deprivation index MEDEA (proportion of unemployed, temporary workers, manual workers, low educational attainment and low educational attainment among youngsters) was estimated for each area based on census data as well as incident diagnoses (ICD-10 codes) of hand, hip or knee OA (2009â2012). Zero-inflated Poisson models were fitted to study the association between MEDEA quintiles and the outcomes.ResultsCompared to the least deprived, the most deprived areas were younger (43.29 (17.59) vs 46.83 (18.49), years (Mean SD), had fewer women (49.1% vs 54.8%), a higher percentage of obese (16.2% vs 8.4%), smokers (16.9% vs 11.9%) and high-risk alcohol consumption subjects (1.5% vs 1.3%). Compared to the least deprived, the most deprived areas had an excess risk of OA: age-sex-adjusted Incidence Rate Ratio (IRR) 1.26 (1.11â1.42) for hand, 1.23 (1.17â1.29) hip, and 1.51 (1.45â1.57) knee. Adjustment for obesity attenuated this association: 1.06 (0.93â1.20), 1.04 (0.99â1.09), and 1.23 (1.19â1.28) respectively.ConclusionsDeprived areas have higher rates OA (hand, hip, knee). Their increased prevalence of obesity accounts for a 50% of the excess risk of knee OA observed. Public health interventions to reduce the prevalence of obesity in this population could reduce health inequalities
18F-FDG-PET Imaging Patterns in Autoimmune Encephalitis: Impact of Image Analysis on the Results
Brain positron emission tomography imaging with 18Fluorine-fluorodeoxyglucose
(FDG-PET) has demonstrated utility in suspected autoimmune encephalitis. Visual and/or
assisted image reading is not well established to evaluate hypometabolism/hypermetabolism.
We retrospectively evaluated patients with autoimmune encephalitis between 2003 and 2018.
Patients underwent EEG, brain magnetic resonance imaging (MRI), cerebrospinal fluid (CSF)
sampling and autoantibodies testing. Individual FDG-PET images were evaluated by standard
visual reading and assisted by voxel-based analyses, compared to a normal database. For the
latter, three different methods were performed: two based on statistical surface projections (Siemens
syngo.via Database Comparison, and 3D-SSP Neurostat) and one based on statistical parametric
mapping (SPM12). Hypometabolic and hypermetabolic findings were grouped to identify specific
patterns. We found six cases with definite diagnosis of autoimmune encephalitis. Two cases had
anti-LGI1, one had anti-NMDA-R and two anti-CASPR2 antibodies, and one was seronegative.
18F-FDG-PET metabolic abnormalities were present in all cases, regardless of the method of analysis.
Medialâtemporal and extra-limbic hypermetabolism were more clearly depicted by voxel-based
analyses. We found autoantibody-specific patterns in line with the literature. Statistical surface
projection (SSP) methods (Neurostat and syngo.via Database Comparison) were more sensitive
and localized larger hypermetabolic areas. As it may lead to comparable and accurate results,
visual analysis of FDG-PET studies for the diagnosis of autoimmune encephalitis benefits from
voxel-based analysis, beyond the approach based on MRI, CSF sample and EEG
Genetic study of atypical femoral fractures using exome sequencing in three affected sisters and three unrelated patients
Objectives: Atypical femoral fractures (AFF) are rare, often related to long-term bisphosphonate (BPs) tre- atment. Their pathogenic mechanisms are not precisely known and there is no evidence to identify patients with a high risk of AFF. The aim of this work is to study the genetic bases of AFFs. Material and methods: Whole-exome sequencing was carried out on 3 sisters and 3 unrelated additional patients, all treated with BPs for more than 5 years. Low frequency, potentially pathogenic variants sha- red by the 3 sisters, were selected, were selected and a network of gene and protein interactions was constructed with the data found. Results: We identified 37 rare variants (in 34 genes) shared by the 3 sisters, some not previously descri- bed. The most striking variant was the p.Asp188Tyr mutation in the enzyme geranylgeranyl pyrophos- phate synthase (encoded by the GGPS1 gene), from the mevalonate pathway and essential for osteoclast function. Another noteworthy finding was two mutations (one in the 3 sisters and one in an unrelated patient) in the CYP1A1 gene, involved in the metabolism of steroids. We identified other variants that could also be involved in the susceptibility to AFFs or in the underlying osteoporotic phenotype, such as those present in the SYDE2, NGEF, COG4 and FN1 genes. Conclusions: Our data are compatible with a model where the accumulation of susceptibility variants could participate in the genetic basis of AFFs
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