High-Resolution Spectroscopic Study of Extremely Metal-Poor Star Candidates from the SkyMapper Survey

The SkyMapper Southern Sky Survey is carrying out a search for the most metal-poor stars in the Galaxy. It identifies candidates by way of its unique filter set that allows for estimation of stellar atmospheric parameters. The set includes a narrow filter centered on the Ca II K 3933A line, enabling a robust estimate of stellar metallicity. Promising candidates are then confirmed with spectroscopy. We present the analysis of Magellan-MIKE high-resolution spectroscopy of 122 metal-poor stars found by SkyMapper in the first two years of commissioning observations. 41 stars have [Fe/H] <= -3.0. Nine have [Fe/H] <= -3.5, with three at [Fe/H] ~ -4. A 1D LTE abundance analysis of the elements Li, C, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Co, Ni, Zn, Sr, Ba and Eu shows these stars have [X/Fe] ratios typical of other halo stars. One star with low [X/Fe] [X/Fe values appears to be "Fe-enhanced," while another star has an extremely large [Sr/Ba] ratio: >2. Only one other star is known to have a comparable value. Seven stars are "CEMP-no" stars ([C/Fe] > 0.7, [Ba/Fe] < 0). 21 stars exhibit mild r-process element enhancements (0.3 <=[Eu/Fe] < 1.0), while four stars have [Eu/Fe] >= 1.0. These results demonstrate the ability to identify extremely metal-poor stars from SkyMapper photometry, pointing to increased sample sizes and a better characterization of the metal-poor tail of the halo metallicity distribution function in the future.Comment: Minor corrections to text, missing data added to Tables 3 and 4; updated to match published version. Complete tables included in sourc

The cometary composition of a protoplanetary disk as revealed by complex cyanides

Observations of comets and asteroids show that the Solar Nebula that spawned our planetary system was rich in water and organic molecules. Bombardment brought these organics to the young Earth's surface, seeding its early chemistry. Unlike asteroids, comets preserve a nearly pristine record of the Solar Nebula composition. The presence of cyanides in comets, including 0.01% of methyl cyanide (CH3CN) with respect to water, is of special interest because of the importance of C-N bonds for abiotic amino acid synthesis. Comet-like compositions of simple and complex volatiles are found in protostars, and can be readily explained by a combination of gas-phase chemistry to form e.g. HCN and an active ice-phase chemistry on grain surfaces that advances complexity[3]. Simple volatiles, including water and HCN, have been detected previously in Solar Nebula analogues - protoplanetary disks around young stars - indicating that they survive disk formation or are reformed in situ. It has been hitherto unclear whether the same holds for more complex organic molecules outside of the Solar Nebula, since recent observations show a dramatic change in the chemistry at the boundary between nascent envelopes and young disks due to accretion shocks[8]. Here we report the detection of CH3CN (and HCN and HC3N) in the protoplanetary disk around the young star MWC 480. We find abundance ratios of these N-bearing organics in the gas-phase similar to comets, which suggests an even higher relative abundance of complex cyanides in the disk ice. This implies that complex organics accompany simpler volatiles in protoplanetary disks, and that the rich organic chemistry of the Solar Nebula was not unique.Comment: Definitive version of the manuscript is published in Nature, 520, 7546, 198, 2015. This is the author's versio

Physical Activity-Related Policy and Environmental Strategies to Prevent Obesity in Rural Communities: A Systematic Review of the Literature, 2002-2013

Citation: Meyer, M. R. U., Perry, C. K., Sumrall, J. C., Patterson, M. S., Walsh, S. M., Clendennen, S. C., . . . Valko, C. (2016). Physical Activity-Related Policy and Environmental Strategies to Prevent Obesity in Rural Communities: A Systematic Review of the Literature, 2002-2013. Preventing Chronic Disease, 13, 24. doi:10.5888/pcd13.150406Additional Authors: Valko, C.Introduction Health disparities exist between rural and urban residents; in particular, rural residents have higher rates of chronic diseases and obesity. Evidence supports the effectiveness of policy and environmental strategies to prevent obesity and promote health equity. In 2009, the Centers for Disease Control and Prevention recommended 24 policy and environmental strategies for use by local communities: the Common Community Measures for Obesity Prevention (COCOMO); 12 strategies focus on physical activity. This review was conducted to synthesize evidence on the implementation, relevance, and effectiveness of physical activity-related policy and environmental strategies for obesity prevention in rural communities. Methods A literature search was conducted in PubMed, PsycINFO, Web of Science, CINHAL, and PAIS databases for articles published from 2002 through May 2013 that reported findings from physical activity-related policy or environmental interventions conducted in the United States or Canada. Each article was extracted independently by 2 researchers. Results Of 2,002 articles, 30 articles representing 26 distinct studies met inclusion criteria. Schools were the most common setting (n = 18 studies). COCOMO strategies were applied in rural communities in 22 studies; the 2 most common COCOMO strategies were "enhance infrastructure supporting walking" (n = 11) and " increase opportunities for extracurricular physical activity" (n = 9). Most studies (n = 21) applied at least one of 8 non-COCOMO strategies; the most common was increasing physical activity opportunities at school outside of physical education (n = 8). Only 14 studies measured or reported physical activity outcomes (10 studies solely used self-report); 10 reported positive changes. Conclusion Seven of the 12 COCOMO physical activity-related strategies were successfully implemented in 2 or more studies, suggesting that these 7 strategies are relevant in rural communities and the other 5 might be less applicable in rural communities. Further research using robust study designs and measurement is needed to better ascertain implementation success and effectiveness of COCOMO and non-COCOMO strategies in rural communities

Delineating the autistic phenotype in children with neurofibromatosis type 1

Background Existing research has demonstrated elevated autistic behaviours in children with neurofibromatosis type 1 (NF1), but the autistic phenotype and its relationship to other neurodevelopmental manifestations of NF1 remains unclear. To address this gap, we performed detailed characterisation of autistic behaviours in children with NF1 and investigated their association with other common NF1 child characteristics. Methods Participants were drawn from a larger cross-sectional study examining autism in children with NF1. The population analysed in this study scored above threshold on the Social Responsiveness Scale-Second Edition (T-score ≥ 60; 51% larger cohort) and completed the Autism Diagnostic Interview-Revised (ADI-R) and/or the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2). All participants underwent evaluation of their intellectual function, and behavioural data were collected via parent questionnaires. Results The study cohort comprised 68 children (3–15 years). Sixty-three per cent met the ADOS-2 ‘autism spectrum’ cut-off, and 34% exceeded the more stringent threshold for ‘autistic disorder’ on the ADI-R. Social communication symptoms were common and wide-ranging, while restricted and repetitive behaviours (RRBs) were most commonly characterised by ‘insistence on sameness’ (IS) behaviours such as circumscribed interests and difficulties with minor changes. Autistic behaviours were weakly correlated with hyperactive/impulsive attention deficit hyperactivity disorder (ADHD) symptoms but not with inattentive ADHD or other behavioural characteristics. Language and verbal IQ were weakly related to social communication behaviours but not to RRBs. Limitations Lack of genetic validation of NF1, no clinical diagnosis of autism, and a retrospective assessment of autistic behaviours in early childhood. Conclusions Findings provide strong support for elevated autistic behaviours in children with NF1. While these behaviours were relatively independent of other NF1 comorbidities, the importance of taking broader child characteristics into consideration when interpreting data from autism-specific measures in this population is highlighted. Social communication deficits appear similar to those observed in idiopathic autism and are coupled with a unique RRB profile comprising prominent IS behaviours. This autistic phenotype and its relationship to common NF1 comorbidities such as anxiety and executive dysfunction will be important to examine in future research. Current findings have important implications for the early identification of autism in NF1 and clinical management

Cognitive interviewing methodology in the development of a pediatric item bank: a patient reported outcomes measurement information system (PROMIS) study

<p>Abstract</p> <p>Background</p> <p>The evaluation of patient-reported outcomes (PROs) in health care has seen greater use in recent years, and methods to improve the reliability and validity of PRO instruments are advancing. This paper discusses the cognitive interviewing procedures employed by the Patient Reported Outcomes Measurement Information System (PROMIS) pediatrics group for the purpose of developing a dynamic, electronic item bank for field testing with children and adolescents using novel computer technology. The primary objective of this study was to conduct cognitive interviews with children and adolescents to gain feedback on items measuring physical functioning, emotional health, social health, fatigue, pain, and asthma-specific symptoms.</p> <p>Methods</p> <p>A total of 88 cognitive interviews were conducted with 77 children and adolescents across two sites on 318 items. From this initial item bank, 25 items were deleted and 35 were revised and underwent a second round of cognitive interviews. A total of 293 items were retained for field testing.</p> <p>Results</p> <p>Children as young as 8 years of age were able to comprehend the majority of items, response options, directions, recall period, and identify problems with language that was difficult for them to understand. Cognitive interviews indicated issues with item comprehension on several items which led to alternative wording for these items.</p> <p>Conclusion</p> <p>Children ages 8–17 years were able to comprehend most item stems and response options in the present study. Field testing with the resulting items and response options is presently being conducted as part of the PROMIS Pediatric Item Bank development process.</p

Detecting Weak Spectral Lines in Interferometric Data through Matched Filtering

Modern radio interferometers enable observations of spectral lines with unprecedented spatial resolution and sensitivity. In spite of these technical advances, many lines of interest are still at best weakly detected and therefore necessitate detection and analysis techniques specialized for the low signal-to-noise ratio (S/N) regime. Matched filters can leverage knowledge of the source structure and kinematics to increase sensitivity of spectral line observations. Application of the filter in the native Fourier domain improves S/N while simultaneously avoiding the computational cost and ambiguities associated with imaging, making matched filtering a fast and robust method for weak spectral line detection. We demonstrate how an approximate matched filter can be constructed from a previously observed line or from a model of the source, and we show how this filter can be used to robustly infer a detection significance for weak spectral lines. When applied to ALMA Cycle 2 observations of CH3OH in the protoplanetary disk around TW Hya, the technique yields a ≈53% S/N boost over aperture-based spectral extraction methods, and we show that an even higher boost will be achieved for observations at higher spatial resolution. A Python-based open-source implementation of this technique is available under the MIT license at http://github.com/AstroChem/VISIBLE

Molecules with ALMA at Planet-forming Scales (MAPS). VIII. CO gap in AS 209-gas depletion or chemical processing?

Funding: I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, SFTC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, and MR/T040726/1).Emission substructures in gas and dust are common in protoplanetary disks. Such substructures can be linked to planet formation or planets themselves. We explore the observed gas substructures in AS 209 using thermochemical modeling with RAC2D and high-spatial-resolution data from the Molecules with ALMA at Planet-forming Scales (MAPS) program. The observations of C18O J = 2-1 emission exhibit a strong depression at 88 au overlapping with the positions of multiple gaps in millimeter dust continuum emission. We find that the observed CO column density is consistent with either gas surface-density perturbations or chemical processing, while C2H column density traces changes in the C/O ratio rather than the H2 gas surface density. However, the presence of a massive planet (>0.2 MJup) would be required to account for this level of gas depression, which conflicts with constraints set by the dust emission and the pressure profile measured by gas kinematics. Based on our models, we infer that a local decrease of CO abundance is required to explain the observed structure in CO, dominating over a possible gap-carving planet present and its effect on the H2 surface density. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

Molecules with ALMA at Planet-forming Scales (MAPS). XI. CN and HCN as tracers of photochemistry in disks

Funding: I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. A.S.B. acknowledges the studentship funded by the Science and Technology Facilities Council of the United Kingdom (STFC). J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, STFC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, MR/T040726/1).UV photochemistry in the surface layers of protoplanetary disks dramatically alters their composition relative to previous stages of star formation. The abundance ratio CN/HCN has long been proposed to trace the UV field in various astrophysical objects; however, to date the relationship between CN, HCN, and the UV field in disks remains ambiguous. As part of the ALMA Large Program MAPS (Molecules with ALMA at Planet-forming Scales), we present observations of CN N = 1-0 transitions at 0.″3 resolution toward five disk systems. All disks show bright CN emission within ~50-150 au, along with a diffuse emission shelf extending up to 600 au. In all sources we find that the CN/HCN column density ratio increases with disk radius from about unity to 100, likely tracing increased UV penetration that enhances selective HCN photodissociation in the outer disk. Additionally, multiple millimeter dust gaps and rings coincide with peaks and troughs, respectively, in the CN/HCN ratio, implying that some millimeter substructures are accompanied by changes to the UV penetration in more elevated disk layers. That the CN/HCN ratio is generally high (>1) points to a robust photochemistry shaping disk chemical compositions and also means that CN is the dominant carrier of the prebiotically interesting nitrile group at most disk radii. We also find that the local column densities of CN and HCN are positively correlated despite emitting from vertically stratified disk regions, indicating that different disk layers are chemically linked. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

TRAF6 Mediates IL-1β/LPS-Induced Suppression of TGF-β Signaling through Its Interaction with the Type III TGF-β Receptor

Transforming growth factor-β1 (TGF-β1) is an important anti-inflammatory cytokine that modulates and resolves inflammatory responses. Recent studies have demonstrated that inflammation enhances neoplastic risk and potentiates tumor progression. In the evolution of cancer, pro-inflammatory cytokines such as IL-1β must overcome the anti-inflammatory effects of TGF-β to boost pro-inflammatory responses in epithelial cells. Here we show that IL-1β or Lipopolysaccharide (LPS) suppresses TGF-β-induced anti-inflammatory signaling in a NF-κB-independent manner. TRAF6, a key molecule in IL-1β signaling, mediates this suppressive effect through interaction with the type III TGF-β receptor (TβRIII), which is TGF-β-dependent and requires type I TGF-β receptor (TβRI) kinase activity. TβRI phosphorylates TβRIII at residue S829, which promotes the TRAF6/TβRIII interaction and consequent sequestration of TβRIII from the TβRII/TβRI complex. Our data indicate that IL-1β enhances the pro-inflammatory response by suppressing TGF-βsignaling through TRAF6-mediated sequestration of TβRIII, which may be an important contributor to the early stages of tumor progression

Molecules with ALMA at Planet-forming Scales (MAPS). XVIII. Kinematic substructures in the disks of HD 163296 and MWC 480

Funding: K.Z., K.R.S., J.H., J.B., J.B.B., and I.C. acknowledge the support of NASA through Hubble Fellowship grants HST-HF2-51401.001, HST-HF2-51419.001, HST-HF2-51460.001-A, HSTHF2-51427.001-A, HST-HF2-51429.001-A, and HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. A.S.B. acknowledges the studentship funded by the Science and Technology Facilities Council of the United Kingdom (STFC). C.W. acknowledges financial support from the University of Leeds, STFC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, MR/T040726/1).We explore the dynamical structure of the protoplanetary disks surrounding HD 163296 and MWC 480 as part of the Molecules with ALMA at Planet-forming Scales (MAPS) large program. Using the J = 2-1 transitions of 12CO, 13CO, and C18O imaged at spatial resolutions of ~0"15 and with a channel spacing of 200 m s-1, we find perturbations from Keplerian rotation in the projected velocity fields of both disks (≲5% of the local Keplerian velocity), suggestive of large-scale (tens of astronomical units in size), coherent flows. By accounting for the azimuthal dependence on the projection of the velocity field, the velocity fields were decomposed into azimuthally averaged orthogonal components, vφ, vr, and vz. Using the optically thick 12CO emission as a probe of the gas temperature, local variations of ≍3 K (≍5% relative changes) were observed and found to be associated with the kinematic substructures. The MWC 480 disk hosts a suite of tightly wound spiral arms. The spirals arms, in conjunction with the highly localized perturbations in the gas velocity structure (kinematic planetary signatures), indicate a giant planet, ~1 MJup, at a radius of ≍245 au. In the disk of HD 163296, the kinematic substructures were consistent with previous studies of Pinte et al. and Teague et al. advocating for multiple ~1 MJup planets embedded in the disk. These results demonstrate that molecular line observations that characterize the dynamical structure of disks can be used to search for the signatures of embedded planets. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe