Percentage of High Schoolers\u27 with Daily Soda Consumption by State Compared to the Percentage of High Schoolers with Obesity by State

We will be presenting a poster on the percentage of high schoolers\u27 with daily soda consumption by state compared to the percentage of high schoolers with obesity by state

What is Missing from the Local Stellar Halo?

The Milky Way's stellar halo, which extends to $>100$ kpc, encodes the evolutionary history of our Galaxy. However, most studies of the halo to date have been limited to within a few kpc of the Sun. Here, we characterize differences between this local halo and the stellar halo in its entirety. We construct a composite stellar halo model by combining observationally motivated N-body simulations of the Milky Way's nine most massive disrupted dwarf galaxies that account for almost all of the mass in the halo. We find that (1) the representation by mass of different dwarf galaxies in the local halo compared to the whole halo can be significantly overestimated (e.g., the Helmi Streams) or underestimated (e.g., Cetus) and (2) properties of the overall halo (e.g., net rotation) inferred via orbit integration of local halo stars are significantly biased, because e.g., highly retrograde debris from Gaia-Sausage-Enceladus is missing from the local halo. Therefore, extrapolations from the local to the global halo should be treated with caution. From analysis of a sample of 11 MW-like simulated halos, we identify a population of recently accreted ($\lesssim5$ Gyrs) and disrupted galaxies on high angular momenta orbits that are entirely missing from local samples, and awaiting discovery in the outer halo. Our results motivate the need for surveys of halo stars extending to the Galaxy's virial radius.Comment: 12 pages, 6 figures. Submitted to ApJ. Comments warmly welcome

Halpha and 4000 Angstrom Break Measurements for ~3500 K-selected Galaxies at 0.5<z<2.0

We measure spectral features of ~3500 K-selected galaxies at 0.5<z<2.0 from high quality medium-band photometry using a new technique. First, we divide the galaxy sample in 32 subsamples based on the similarities between the full spectral energy distributions (SEDs) of the galaxies. For each of these 32 galaxy types we construct a composite SED by de-redshifting and scaling the observed photometry. This approach increases the signal-to-noise ratio and sampling of galaxy SEDs and allows for model-independent stellar population studies. The composite SEDs are of spectroscopic quality, and facilitate -- for the first time -- Halpha measurement for a large magnitude-limited sample of distant galaxies. The linewidths indicate a photometric redshift uncertainty of dz<0.02x(1+z). The composite SEDs also show the Balmer and 4000 Angstrom breaks, MgII absorption at ~2800 Angstrom, the dust absorption feature at 2175 Angstrom, and blended [OIII]+Hbeta emission. We compare the total equivalent width of Halpha, [NII], and [SII] (W_Halpha+) with the strength of the 4000 Angstrom break (D(4000)) and the best-fit specific star formation rate, and find that all these properties are strongly correlated. This is a reassuring result, as currently most distant stellar population studies are based on just continuum emission. Furthermore, the relation between W_Halpha+ and Dn(4000) provides interesting clues to the SFHs of galaxies, as these features are sensitive to different stellar ages. We find that the correlation between W_Halpha+ and D(4000) at 0.5<z<2.0 is similar to z~0, and that the suppression of star formation in galaxies at z<2 is generally not abrupt, but a gradual process.Comment: Accepted for publication in ApJ; high-resolution version can be downloaded at https://www.cfa.harvard.edu/~mkriek/papers

COS-Speech: Protocol to develop a core outcome set for dysarthria after stroke for use in clinical practice and research

BACKGROUND: Dysarthria after stroke is when speech intelligibility is impaired, and this occurs in half of all stroke survivors. Dysarthria often leads to social isolation, poor psychological well-being and can prevent return to work and social lives. Currently, a variety of outcome measures are used in clinical research and practice when monitoring recovery for people who have dysarthria. When research studies use different measures, it is impossible to compare results from trials and delays our understanding of effective clinical treatments. The aim of this study is to develop a core outcome set (COS) to agree what aspects of speech recovery should be measured for dysarthria after stroke (COS-Speech) in research and clinical practice. METHODS: The COS-Speech study will include five steps: (1) development of a long list of possible outcome domains of speech that should be measured to guide the survey; (2) recruitment to the COS-Speech study of three key stakeholder groups in the UK and Australia: stroke survivors, communication researchers and speech and language therapists/pathologists; (3) two rounds of the Delphi survey process; (4) a consensus meeting to agree the speech outcomes to be measured and a follow-up consensus meeting to match existing instruments/measures (from parallel systematic review) to the agreed COS-Speech; (5) dissemination of COS-Speech. DISCUSSION: There is currently no COS for dysarthria after stroke for research trials or clinical practice. The findings from this research study will be a minimum COS, for use in all dysarthria research studies and clinical practice looking at post-stroke recovery of speech. These findings will be widely disseminated using professional and patient networks, research and clinical forums as well as using a variety of academic papers, videos, accessible writing such as blogs and links on social media. TRIAL REGISTRATION: COS-Speech is registered with the Core Outcome Measures in Effectiveness Trials (COMET) database, October 2021 https://www.comet-initiative.org/Studies/Details/1959. In addition, “A systematic review of the psychometric properties and clinical utility of instruments measuring dysarthria after stroke” will inform the consensus meeting to match measures to COS-Speech. The protocol for the systematic reviews registered with the International Prospective Register of Systematic Reviews. PROSPERO registration number: CRD42022302998. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-022-06958-7

Direct measurements of dust attenuation in z~1.5 star-forming galaxies from 3D-HST: Implications for dust geometry and star formation rates

The nature of dust in distant galaxies is not well understood, and until recently few direct dust measurements have been possible. We investigate dust in distant star-forming galaxies using near-infrared grism spectra of the 3D-HST survey combined with archival multi-wavelength photometry. These data allow us to make a direct comparison between dust around star-forming regions ($A_{V,\mathrm{HII}}$) and the integrated dust content ($A_{V,\mathrm{star}}$). We select a sample of 163 galaxies between $1.36\le{}z\le1.5$ with H$\alpha$ signal-to-noise ratio $\ge5$ and measure Balmer decrements from stacked spectra to calculate $A_{V,\mathrm{HII}}$. First, we stack spectra in bins of $A_{V,\mathrm{star}}$, and find that $A_{V,\mathrm{HII}}=1.86\,A_{V,\mathrm{star}}$, with a significance of $\sigma=1.7$. Our result is consistent with the two-component dust model, in which galaxies contain both diffuse and stellar birth cloud dust. Next, we stack spectra in bins of specific star formation rate ($\log\,\mathrm{SSFR}$), star formation rate ($\log\,\mathrm{SFR}$), and stellar mass ($\log{}M_*$). We find that on average $A_{V,\mathrm{HII}}$ increases with SFR and mass, but decreases with increasing SSFR. Interestingly, the data hint that the amount of extra attenuation decreases with increasing SSFR. This trend is expected from the two-component model, as the extra attenuation will increase once older stars outside the star-forming regions become more dominant in the galaxy spectrum. Finally, using Balmer decrements we derive dust-corrected H$\alpha$ SFRs, and find that stellar population modeling produces incorrect SFRs if rapidly declining star formation histories are included in the explored parameter space.Comment: Accepted for publication in the Astrophysical Journal (13 pages, 9 figures

Exploring the chemical link between local ellipticals and their high-redshift progenitors

We present Keck/MOSFIRE K-band spectroscopy of the first mass-selected sample of galaxies at $z\sim2.3$. Targets are selected from the 3D-HST Treasury survey. The six detected galaxies have a mean [NII]$\lambda$6584/H$\alpha$ ratio of $0.27\pm0.01$, with a small standard deviation of 0.05. This mean value is similar to that of UV-selected galaxies of the same mass. The mean gas-phase oxygen abundance inferred from the [NII]/H$\alpha$ ratios depends on the calibration method, and ranges from 12+log(O/H)$_{gas}=8.57$ for the {Pettini} & {Pagel} (2004) calibration to 12+log(O/H)$_{gas}= 8.87$ for the {Maiolino} {et~al.} (2008) calibration. Measurements of the stellar oxygen abundance in nearby quiescent galaxies with the same number density indicate 12+log(O/H)$_{stars}= 8.95$, similar to the gas-phase abundances of the $z\sim2.3$ galaxies if the {Maiolino} {et~al.} (2008) calibration is used. This suggests that these high-redshift star forming galaxies may be progenitors of today's massive early-type galaxies. The main uncertainties are the absolute calibration of the gas-phase oxygen abundance and the incompleteness of the $z\sim2.3$ sample: the galaxies with detected H$\alpha$ tend to be larger and have higher star formation rates than the galaxies without detected H$\alpha$, and we may still be missing the most dust-obscured progenitors.Comment: 7 pages, 5 figures. Accepted for publication in ApJ

Galaxy clustering in the NEWFIRM Medium Band Survey: the relationship between stellar mass and dark matter halo mass at 1 < z < 2

We present an analysis of the clustering of galaxies as a function of their stellar mass at 1 < z < 2 using data from the NEWFIRM Medium Band Survey (NMBS). The precise photometric redshifts and stellar masses that the NMBS produces allows us to define a series of mass limited samples of galaxies more massive than 0.7, 1 and 3x10^10 Msun in redshift intervals centered on z = 1.1, 1.5 and 1.9 respectively. In each redshift interval we show that there exists a strong dependence of clustering strength on the stellar mass limit of the sample, with more massive galaxies showing a higher clustering amplitude on all scales. We further interpret our clustering measurements in the LCDM cosmological context using the halo model of galaxy clustering. We show that the typical halo mass of central and satellite galaxies increases with stellar mass, whereas the satellite fraction decreases with stellar mass, qualitatively the same as is seen at z < 1. We see little evidence of any redshift dependence in the stellar mass-to-halo mass relationship over our narrow redshift range. However, when we compare with similar measurements at z~0, we see clear evidence for a change in this relation. If we assume a universal baryon fraction, the ratio of stellar mass to halo mass reveals the fraction of baryons that have been converted to stars. We see that the peak in this star formation efficiency for central galaxies shifts to higher halo masses at higher redshift, moving from ~7x10^11 Msun at z~0 to ~3x10^12 Msun at z~1.5, revealing evidence of `halo downsizing'. Finally we show that for highly biased galaxy populations at z > 1 there may be a discrepancy between the measured space density and clustering and that predicted by the halo model. This could imply that there is a problem with one or more ingredients of the halo model at these redshifts, for instance the halo bias relation or the halo profile.Comment: Accepted for publication in ApJ. Correction made to typo in halo masses in conclusion