High-Resolution Measurements of the Dark Matter Halo of NGC 2976: Evidence for a Shallow Density Profile

We have obtained two-dimensional velocity fields of the dwarf spiral galaxy NGC 2976 in Halpha and CO. The high spatial (~75 pc) and spectral (13 km/s and 2 km/s, respectively) resolution of these observations, along with our multicolor optical and near-infrared imaging, allow us to measure the shape of the density profile of the dark matter halo with good precision. We find that the total (baryonic plus dark matter) mass distribution of NGC 2976 follows a rho_tot ~ r^(-0.27 +/- 0.09) power law out to a radius of 1.8 kpc, assuming that the observed radial motions provide no support. The density profile attributed to the dark halo is even shallower, consistent with a nearly constant density of dark matter over the entire observed region. A maximal disk fit yields an upper limit to the K-band stellar mass-to-light ratio (M*/L_K) of 0.09^{+0.15}_{-0.08} M_sun/L_sun,K (including systematic uncertainties), with the caveat that for M*/L_K > 0.19 M_sun/L_sun,K the dark matter density increases with radius, which is unphysical. Assuming 0.10 M_sun/L_sun,K < M*/L_K < 0.19 M_sun/L_sun,K, the dark matter density profile lies between rho_dm ~ r^-0.17 and rho_dm ~ r^-0.01. Therefore, independent of any assumptions about the stellar disk or the functional form of the density profile, NGC 2976 does not contain a cuspy dark matter halo. We also investigate some of the systematic effects that can hamper rotation curve studies, and show that 1) longslit rotation curves are far more vulnerable to systematic errors than two-dimensional velocity fields, 2) NGC 2976 contains large radial motions at small radii, and 3) the Halpha and CO velocity fields of NGC 2976 agree within their uncertainties. [slightly abridged]Comment: 30 pages, 4 tables, 13 figures (7 in color; Figures 1 and 3 are low-resolution to save space). Accepted for publication in ApJ. Version with full-resolution figures available at http://astro.berkeley.edu/~bolatto/ngc2976rotation.ps (46 MB

Identifying behavioural characteristics of tobacco product and e-cigarette use clusters: A repeat cross-sectional analysis

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.addbeh.2018.10.026 © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Background Youth may use a variety of tobacco products and e-cigarettes. However, there is a lack of evidence for the combinations of tobacco products and e-cigarettes commonly used by youth in Canada and whether youth from different usage classes share similar characteristics. Methods A cohort of 9th grade students from Ontario, Canada was identified at baseline (2013–14) of the COMPASS study (n = 4651). Classes of youth that currently use similar combinations of tobacco products and e-cigarettes were identified at baseline, one (FY1) and two years later (FY2) using latent class analysis. Multinomial logistic regression models identified demographic and behavioural characteristics (e.g., environmental influences, substance use behaviours, etc.) of youth in current tobacco and e-cigarette use classes relative to youth in non-current use classes. Results At baseline, a three-class model was identified as best, while a four-class model was identified at FY1 and FY2. A non-current use group and an all-product use group were identified every year. Students that reported having friends that smoked cigarettes, binge drinking, and using marijuana were more likely to be classified into a current use class. Conclusions Tobacco cigarettes were more likely to be used with other products than on their own. An all-product use group was identified across all three survey waves and the prevalence of this group increased over time. Given that many youth in this study used more than one tobacco product or e-cigarette and commonly reported binge drinking and using marijuana, prevention and cessation activities should address the use of multiple products.Canadian Institutes of Health Research ["GSD-140312","OOP-110788, MOP-114875"]Public Health Agency of Canada in partnership with Canadian Institutes of Health Research",[]

More support needed: Evaluating the impact of school e-cigarette prevention and cessation programs on e-cigarette initiation among a sample of Canadian secondary school students

Given the recent increase in e-cigarette use among adolescents, there is a need to further explore how school programs are associated with e-cigarette initiation. The objective of this quasi-experimental study was to evaluate the impact of multiple school-based e-cigarette prevention and cessation programs on e-cigarette initiation among Canadian adolescents. This study used data from Year 6 (2017/18) and Year 7 (2018/19) of the COMPASS study in British Columbia, Alberta, Ontario, and Quebec, Canada. Students in grades 9 to 11 who had never tried e-cigarettes at baseline were included (n = 13,269). Schools (n = 88) reported whether they added programming that addressed e-cigarette or tobacco prevention or cessation. Generalized estimating equations were used to identify how added programs were associated with e-cigarette initiation at follow-up. At one-year follow-up (2018/19), 23% of schools added programs. Our evaluation results suggest that none of the activities taken by schools to prevent or reduce vaping among students significantly prevented vaping onset. In fact, female students at schools that reported adding a theme week had higher odds of e-cigarette initiation (OR 1.68 [95% CI 1.31–2.16]) and male students at schools that reported a cessation program had higher odds of e-cigarette initiation (OR 1.20 [95% CI 1.01–1.44]). These results suggest that schools may not know how to address e-cigarette use and that there can be risks to students if programs are not carefully implemented. Results point to the need for additional support to ensure that schools are taking evidence-based approaches that support all students.CIHR Institute of Nutrition, Metabolism and Diabetes || CIHR Institute of Population and Public Health || CIHR-Canadian Centre on Substance Abuse || Health Canada || Ministère de la Santé et des Services sociaux || Direction régionale de santé publique du CIUSSS de la Capitale-Nationale

Recoil Studies in the Reaction of 12-C Ions with the Enriched Isotope 118-Sn

The recoil properties of the product nuclei from the interaction of 2.2 GeV/nucleon 12-C ions from Nuclotron of the Laboratory of High Energies (LHE), Joint Institute for Nuclear Research (JINR) at Dubna with a 118-Sn target have been studied using catcher foils. The experimental data were analyzed using the mathematical formalism of the standard two-step vector model. The results for 12-C ions are compared with those for deuterons and protons. Three different Los Alamos versions of the Quark-Gluon String Model (LAQGSM) were used for comparison with our experimental data.Comment: 10 pages, 6 figures, submitted to Nucl. Phys.

De novo assembly of the cattle reference genome with single-molecule sequencing.

BackgroundMajor advances in selection progress for cattle have been made following the introduction of genomic tools over the past 10-12 years. These tools depend upon the Bos taurus reference genome (UMD3.1.1), which was created using now-outdated technologies and is hindered by a variety of deficiencies and inaccuracies.ResultsWe present the new reference genome for cattle, ARS-UCD1.2, based on the same animal as the original to facilitate transfer and interpretation of results obtained from the earlier version, but applying a combination of modern technologies in a de novo assembly to increase continuity, accuracy, and completeness. The assembly includes 2.7 Gb and is &gt;250× more continuous than the original assembly, with contig N50 &gt;25 Mb and L50 of 32. We also greatly expanded supporting RNA-based data for annotation that identifies 30,396 total genes (21,039 protein coding). The new reference assembly is accessible in annotated form for public use.ConclusionsWe demonstrate that improved continuity of assembled sequence warrants the adoption of ARS-UCD1.2 as the new cattle reference genome and that increased assembly accuracy will benefit future research on this species

School start time changes in the COMPASS study: associations with youth sleep duration, physical activity, and screen time

The final publication is available at Elsevier via https://doi.org/10.1016/j.sleep.2018.09.020� 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Background To date, no longitudinal population-based studies of school start times have been conducted within Canada. School schedule changes provided an opportunity to examine start times in association with youth sleep, physical activity, and screen use over time. Methods This longitudinal study included grade 9�12 students attending 49 Ontario secondary schools that participated in at least two consecutive years of the COMPASS study (2012�2017). Fixed effects models tested whether differences in within-student change in self-reported sleep duration, moderate-to-vigorous physical activity, and screen time were associated with school start time changes, adjusting for student- (grade, sex, ethnicity, spending money) and school-level covariates (median income, urbanicity, geographical area). Results Thirteen start time changes of 5�10�min were reported. Ten-minute advances at earlier clock times (8:30 AM�8:20 AM; 8:40 AM�8:30 AM) were associated with steeper sleep duration declines than schools with consistent start times but had no effect at later times (9:00 AM�8:50 AM). While sleep change did not differ with 5-min�delays, 10-min�delays (8:50 AM�9:00 AM) were associated with additional sleep (23.7�min). Apart from one school that shifted from 8:30 AM to 8:35 AM, in which screen time and physical activity decreased more steeply, no effect was found for screen time, and 5-min�delays were associated with more physical activity (10.9�min) and advances with less activity (_8.0�min). Conclusions Results support start time delays as a valuable strategy to help ameliorate sleep debt among youth. Interference with physical activity or increased screen time appear unlikely with modest schedule changes. Potential adverse impacts on sleep require consideration with 10-min�advances.Canadian Institutes of Health Research Institute of Nutrition, Metabolism and Diabetes [grant OOP-110788]Canadian Institutes of Health Research Institute of Population and Public Health [grant MOP-114875]Canadian Institutes of Health Research Project Grant [grant PJT-148562]Canadian Institutes of Health Research New Investigator Salary AwardCanadian Institutes of Health Research Doctoral Research Awar

In situ XPS of Competitive CO2/H2O Absorption in an Ionic Liquid

Superbasic ionic liquids (SBILs) are being investigated as potential CO2 gas capture agents, however, the presence of H2O in the flue stream can inhibit the uptake of CO2. In this study a thin film of the SBIL trihexyltetradecylphosphonium 1,2,4-triazolide ([P66614][124Triz]) was deposited onto rutile TiO2 (110) using in situ electrospray deposition and studied upon exposure to CO2 and H2O using in situ near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS). The molar uptake ratio of gas in the electrosprayed SBIL (ngas:nIL) was calculated to be 0.3:1 for CO2, 0.7:1 for H2O, and 0.9:1 for a CO2/ H2O mixture. NAP-XPS taken at two different depths reveals that the competitive absorption of CO2 and H2O in [P66614][124Triz] varies with sampling depth. A greater concentration of CO2 absorbs in the bulk layers, while more H2O adsorbs/absorbs at the surface. The presence of H2O in the gas mixture does not inhibit the absorption of CO2. Measurements taken during exposure and after the removal of gas indicate that CO2 absorbed in the bulk does so reversibly, whilst CO2 adsorbed/absorbed at the surface does so irreversibly. This is contrary to the fully reversible CO2 reaction shown for bulk ILs in literature and suggests that irreversible absorption of CO2 in our highly-structured thin films is largely attributed to reactions at the surface. This has potential implications on IL gas capture and thin film IL catalysis applications

Genome-Wide ENU Mutagenesis in Combination with High Density SNP Analysis and Exome Sequencing Provides Rapid Identification of Novel Mouse Models of Developmental Disease

BACKGROUND Mice harbouring gene mutations that cause phenotypic abnormalities during organogenesis are invaluable tools for linking gene function to normal development and human disorders. To generate mouse models harbouring novel alleles that are involved in organogenesis we conducted a phenotype-driven, genome-wide mutagenesis screen in mice using the mutagen N-ethyl-N-nitrosourea (ENU). METHODOLOGY/PRINCIPAL FINDINGS ENU was injected into male C57BL/6 mice and the mutations transmitted through the germ-line. ENU-induced mutations were bred to homozygosity and G3 embryos screened at embryonic day (E) 13.5 and E18.5 for abnormalities in limb and craniofacial structures, skin, blood, vasculature, lungs, gut, kidneys, ureters and gonads. From 52 pedigrees screened 15 were detected with anomalies in one or more of the structures/organs screened. Using single nucleotide polymorphism (SNP)-based linkage analysis in conjunction with candidate gene or next-generation sequencing (NGS) we identified novel recessive alleles for Fras1, Ift140 and Lig1. CONCLUSIONS/SIGNIFICANCE In this study we have generated mouse models in which the anomalies closely mimic those seen in human disorders. The association between novel mutant alleles and phenotypes will lead to a better understanding of gene function in normal development and establish how their dysfunction causes human anomalies and disease.This work was enabled by the Australian Phenomics Network and partly supported by funding from the Australian Government’s National Collaborative Research Infrastructure Strategy, a Strategic Grant from the Faculty of Medicine, Nursing and Health Sciences at Monash University, and the Victorian Government’s Operational Infrastructure Support Program. IS acknowledges support through the NH&MRC R. Douglas Wright and ARC Future Fellowship schemes. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Broadband Dielectric Spectroscopy on Glass-Forming Propylene Carbonate

Dielectric spectroscopy covering more than 18 decades of frequency has been performed on propylene carbonate in its liquid and supercooled-liquid state. Using quasi-optic submillimeter and far-infrared spectroscopy the dielectric response was investigated up to frequencies well into the microscopic regime. We discuss the alpha-process whose characteristic timescale is observed over 14 decades of frequency and the excess wing showing up at frequencies some three decades above the peak frequency. Special attention is given to the high-frequency response of the dielectric loss in the crossover regime between alpha-peak and boson-peak. Similar to our previous results in other glass forming materials we find evidence for additional processes in the crossover regime. However, significant differences concerning the spectral form at high frequencies are found. We compare our results to the susceptibilities obtained from light scattering and to the predictions of various models of the glass transition.Comment: 13 pages, 9 figures, submitted to Phys. Rev.

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measurements of the growth of structure and expansion rate at z=0.57 from anisotropic clustering

We analyze the anisotropic clustering of massive galaxies from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) sample, which consists of 264,283 galaxies in the redshift range 0.43 < z < 0.7 spanning 3,275 square degrees. Both peculiar velocities and errors in the assumed redshift-distance relation ("Alcock-Paczynski effect") generate correlations between clustering amplitude and orientation with respect to the line-of-sight. Together with the sharp baryon acoustic oscillation (BAO) standard ruler, our measurements of the broadband shape of the monopole and quadrupole correlation functions simultaneously constrain the comoving angular diameter distance (2190 +/- 61 Mpc) to z=0.57, the Hubble expansion rate at z=0.57 (92.4 +/- 4.5 km/s/Mpc), and the growth rate of structure at that same redshift (d sigma8/d ln a = 0.43 +/- 0.069). Our analysis provides the best current direct determination of both DA and H in galaxy clustering data using this technique. If we further assume a LCDM expansion history, our growth constraint tightens to d sigma8/d ln a = 0.415 +/- 0.034. In combination with the cosmic microwave background, our measurements of DA, H, and growth all separately require dark energy at z > 0.57, and when combined imply \Omega_{\Lambda} = 0.74 +/- 0.016, independent of the Universe's evolution at z<0.57. In our companion paper (Samushia et al. prep), we explore further cosmological implications of these observations.Comment: 19 pages, 11 figures, submitted to MNRAS, comments welcom