117 research outputs found

    The mPower Study, Parkinson Disease Mobile Data Collected Using Researchkit

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    Current measures of health and disease are often insensitive, episodic, and subjective. Further, these measures generally are not designed to provide meaningful feedback to individuals. The impact of high-resolution activity data collected from mobile phones is only beginning to be explored. Here we present data from mPower, a clinical observational study about Parkinson disease conducted purely through an iPhone app interface. The study interrogated aspects of this movement disorder through surveys and frequent sensor-based recordings from participants with and without Parkinson disease. Benefitting from large enrollment and repeated measurements on many individuals, these data may help establish baseline variability of real-world activity measurement collected via mobile phones, and ultimately may lead to quantification of the ebbs-and-flows of Parkinson symptoms. App source code for these data collection modules are available through an open source license for use in studies of other conditions. We hope that releasing data contributed by engaged research participants will seed a new community of analysts working collaboratively on understanding mobile health data to advance human health

    The Spatial Distribution of Dust and Stellar Emission of the Magellanic Clouds

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    We study the emission by dust and stars in the Large and Small Magellanic Clouds, a pair of low-metallicity nearby galaxies, as traced by their spatially resolved spectral energy distributions (SEDs). This project combines Herschel Space Observatory PACS and SPIRE far-infrared photometry with other data at infrared and optical wavelengths. We build maps of dust and stellar luminosity and mass of both Magellanic Clouds, and analyze the spatial distribution of dust/stellar luminosity and mass ratios. These ratios vary considerably throughout the galaxies, generally between the range 0.01≀Ldust/L∗≀0.60.01\leq L_{\rm dust}/L_\ast\leq 0.6 and 10−4≀Mdust/M∗≀4×10−310^{-4}\leq M_{\rm dust}/M_\ast\leq 4\times10^{-3}. We observe that the dust/stellar ratios depend on the interstellar medium (ISM) environment, such as the distance from currently or previously star-forming regions, and on the intensity of the interstellar radiation field (ISRF). In addition, we construct star formation rate (SFR) maps, and find that the SFR is correlated with the dust/stellar luminosity and dust temperature in both galaxies, demonstrating the relation between star formation, dust emission and heating, though these correlations exhibit substantial scatter.Comment: 15 pages, 18 figures; ApJ, in press; version published in the journal will have higher-resolution figure

    Dust and gas in the magellanic clouds from the heritage herschel key project. II. Gas-to-dust ratio variations across interstellar medium phases

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    The spatial variations of the gas-to-dust ratio (GDR) provide constraints on the chemical evolution and lifecycle of dust in galaxies. We examine the relation between dust and gas at 10-50 pc resolution in the Large and Small Magellanic Clouds (LMC and SMC) based on Herschel far-infrared (FIR), HI 21 cm, CO, and Hiα observations. In the diffuse atomic interstellar medium (ISM), we derive the GDR as the slope of the dust-gas relation and find GDRs of 380-130+250 ± 3 in the LMC, and 1200-420+1600 ± 120 in the SMC, not including helium. The atomic-to-molecular transition is located at dust surface densities of 0.05 M⊙ pc-2 in the LMC and 0.03 M⊙ pc-2 in the SMC, corresponding to AV ∌ 0.4 and 0.2, respectively. We investigate the range of CO-to-H2 conversion factor to best account for all the molecular gas in the beam of the observations, and find upper limits on XCO to be 6 × 1020 cm-2 K-1 km-1 s in the LMC (Z = 0.5 Z⊙) at 15 pc resolution, and 4 × 1021 cm-2 K-1 km-1 s in the SMC (Z = 0.2 Z⊙) at 45 pc resolution. In the LMC, the slope of the dust-gas relation in the dense ISM is lower than in the diffuse ISM by a factor ∌2, even after accounting for the effects of CO-dark H2 in the translucent envelopes of molecular clouds. Coagulation of dust grains and the subsequent dust emissivity increase in molecular clouds, and/or accretion of gas-phase metals onto dust grains, and the subsequent dust abundance (dust-to-gas ratio) increase in molecular clouds could explain the observations. In the SMC, variations in the dust-gas slope caused by coagulation or accretion are degenerate with the effects of CO-dark H2. Within the expected 5-20 times Galactic XCO range, the dust-gas slope can be either constant or decrease by a factor of several across ISM phases. Further modeling and observations are required to break the degeneracy between dust grain coagulation, accretion, and CO-dark H2. Our analysis demonstrates that obtaining robust ISM masses remains a non-trivial endeavor even in the local Universe using state-of-the-art maps of thermal dust emissio

    Dust and Gas in the Magellanic Clouds from the HERITAGE Herschel Key Project. II. Gas-to-Dust Ratio Variations across ISM Phases

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    The spatial variations of the gas-to-dust ratio (GDR) provide constraints on the chemical evolution and lifecycle of dust in galaxies. We examine the relation between dust and gas at 10-50 pc resolution in the Large and Small Magellanic Clouds (LMC and SMC) based on Herschel far-infrared (FIR), H I 21 cm, CO, and Halpha observations. In the diffuse atomic ISM, we derive the gas-to-dust ratio as the slope of the dust-gas relation and find gas-to-dust ratios of 380+250-130 in the LMC, and 1200+1600-420 in the SMC, not including helium. The atomic-to-molecular transition is located at dust surface densities of 0.05 Mo pc-2 in the LMC and 0.03 Mo pc-2 in the SMC, corresponding to AV ~ 0.4 and 0.2, respectively. We investigate the range of CO-to-H2 conversion factor to best account for all the molecular gas in the beam of the observations, and find upper limits on XCO to be 6x1020 cm-2 K-1 km-1 s in the LMC (Z=0.5Zo) at 15 pc resolution, and 4x 1021 cm-2 K-1 km-1 s in the SMC (Z=0.2Zo) at 45 pc resolution. In the LMC, the slope of the dust-gas relation in the dense ISM is lower than in the diffuse ISM by a factor ~2, even after accounting for the effects of CO-dark H2 in the translucent envelopes of molecular clouds. Coagulation of dust grains and the subsequent dust emissivity increase in molecular clouds, and/or accretion of gas-phase metals onto dust grains, and the subsequent dust abundance (dust-to-gas ratio) increase in molecular clouds could explain the observations. In the SMC, variations in the dust-gas slope caused by coagulation or accretion are degenerate with the effects of CO-dark H2. Within the expected 5--20 times Galactic XCO range, the dust-gas slope can be either constant or decrease by a factor of several across ISM phases. Further modeling and observations are required to break the degeneracy between dust grain coagulation, accretion, and CO-dark H2

    Impact of Young Age on Treatment Efficacy and Safety in Advanced Colorectal Cancer: A Pooled Analysis of Patients From Nine First-Line Phase III Chemotherapy Trials

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    Colorectal cancer predominantly occurs in the elderly, but approximately 5% of patients are 50 years old or younger. We sought to determine whether young age is prognostic, or whether it influences efficacy/toxicity of chemotherapy, in patients with advanced disease
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