740 research outputs found
Traffic-related air pollution and obesity formation in children: a longitudinal, multilevel analysis.
BackgroundBiologically plausible mechanisms link traffic-related air pollution to metabolic disorders and potentially to obesity. Here we sought to determine whether traffic density and traffic-related air pollution were positively associated with growth in body mass index (BMIâ=âkg/m2) in children aged 5-11 years.MethodsParticipants were drawn from a prospective cohort of children who lived in 13 communities across Southern California (Nâ=â4550). Children were enrolled while attending kindergarten and first grade and followed for 4 years, with height and weight measured annually. Dispersion models were used to estimate exposure to traffic-related air pollution. Multilevel models were used to estimate and test traffic density and traffic pollution related to BMI growth. Data were collected between 2002-2010 and analyzed in 2011-12.ResultsTraffic pollution was positively associated with growth in BMI and was robust to adjustment for many confounders. The effect size in the adjusted model indicated about a 13.6% increase in annual BMI growth when comparing the lowest to the highest tenth percentile of air pollution exposure, which resulted in an increase of nearly 0.4 BMI units on attained BMI at age 10. Traffic density also had a positive association with BMI growth, but this effect was less robust in multivariate models.ConclusionsTraffic pollution was positively associated with growth in BMI in children aged 5-11 years. Traffic pollution may be controlled via emission restrictions; changes in land use that promote jobs-housing balance and use of public transit and hence reduce vehicle miles traveled; promotion of zero emissions vehicles; transit and car-sharing programs; or by limiting high pollution traffic, such as diesel trucks, from residential areas or places where children play outdoors, such as schools and parks. These measures may have beneficial effects in terms of reduced obesity formation in children
The MASSIVE Survey - VII. The Relationship of Angular Momentum, Stellar Mass and Environment of Early-Type Galaxies
We analyse the environmental properties of 370 local early-type galaxies
(ETGs) in the MASSIVE and ATLAS3D surveys, two complementary volume-limited
integral-field spectroscopic (IFS) galaxy surveys spanning absolute -band
magnitude , or stellar mass . We find these galaxies to reside in a diverse range of
environments measured by four methods: group membership (whether a galaxy is a
brightest group/cluster galaxy, satellite, or isolated), halo mass, large-scale
mass density (measured over a few Mpc), and local mass density (measured within
the th neighbour). The spatially resolved IFS stellar kinematics provide
robust measurements of the spin parameter and enable us to examine
the relationship among , , and galaxy environment. We find a
strong correlation between and , where the average
decreases from to below 0.1 with increasing mass, and the fraction
of slow rotators increases from % to 90%. We show for
the first time that at fixed , there are almost no trends between galaxy
spin and environment; the apparent kinematic morphology-density relation for
ETGs is therefore primarily driven by and is accounted for by the joint
correlations between and spin, and between and environment. A
possible exception is that the increased at high local density
is slightly more than expected based only on these joint correlations. Our
results suggest that the physical processes responsible for building up the
present-day stellar masses of massive galaxies are also very efficient at
reducing their spin, in any environment.Comment: Accepted to MNRA
Incidence of WISE -selected obscured AGNs in major mergers and interactions from the SDSS
We use the Wide-field Infrared Survey Explorer (WISE) and the Sloan Digital Sky Survey (SDSS) to confirm a connection between dust-obscured active galactic nuclei (AGNs) and galaxy merging. Using a new, volume-limited (z †0.08) catalogue of visually selected major mergers and galaxyâgalaxy interactions from the SDSS, with stellar masses above 2 Ă 1010 Mâ, we find that major mergers (interactions) are 5â17 (3â5) times more likely to have red [3.4] â [4.6] colours associated with dust-obscured or âdustyâ AGNs, compared to non-merging galaxies with similar masses. Using published fibre spectral diagnostics, we map the [3.4] â [4.6] versus [4.6] â [12] colours of different emission-line galaxies and find that one-quarter of Seyferts have colours indicative of a dusty AGN. We find that AGNs are five times more likely to be obscured when hosted by a merging galaxy, half of AGNs hosted by a merger are dusty, and we find no enhanced frequency of optical AGNs in merging over non-merging galaxies. We conclude that undetected AGNs missed at shorter wavelengths are at the heart of the ongoing AGN-merger connection debate. The vast majority of mergers hosting dusty AGNs are star forming and located at the centres of Mhalo < 1013 Mâ groups. Assuming plausibly short-duration dusty-AGN phases, we speculate that a large fraction of gas-rich mergers experience a brief obscured AGN phase, in agreement with the strong connection between central star formation and black hole growth seen in merger simulations
Incidence of WISE -selected obscured AGNs in major mergers and interactions from the SDSS
We use the Wide-field Infrared Survey Explorer (WISE) and the Sloan Digital Sky Survey (SDSS) to confirm a connection between dust-obscured active galactic nuclei (AGNs) and galaxy merging. Using a new, volume-limited (z †0.08) catalogue of visually selected major mergers and galaxyâgalaxy interactions from the SDSS, with stellar masses above 2 Ă 1010 Mâ, we find that major mergers (interactions) are 5â17 (3â5) times more likely to have red [3.4] â [4.6] colours associated with dust-obscured or âdustyâ AGNs, compared to non-merging galaxies with similar masses. Using published fibre spectral diagnostics, we map the [3.4] â [4.6] versus [4.6] â [12] colours of different emission-line galaxies and find that one-quarter of Seyferts have colours indicative of a dusty AGN. We find that AGNs are five times more likely to be obscured when hosted by a merging galaxy, half of AGNs hosted by a merger are dusty, and we find no enhanced frequency of optical AGNs in merging over non-merging galaxies. We conclude that undetected AGNs missed at shorter wavelengths are at the heart of the ongoing AGN-merger connection debate. The vast majority of mergers hosting dusty AGNs are star forming and located at the centres of Mhalo < 1013 Mâ groups. Assuming plausibly short-duration dusty-AGN phases, we speculate that a large fraction of gas-rich mergers experience a brief obscured AGN phase, in agreement with the strong connection between central star formation and black hole growth seen in merger simulations
Définir les compétences procédurales essentielles dans la formation médicale canadienne de premier cycle
Introduction: We conducted a national survey to characterize current Canadian procedural skills training in Undergraduate Medical Education (UGME). The goals were to identify the most important procedures students should know upon graduation and assess clinician-educator perceptions regarding implementation of a pre-clerkship procedural program.
Methods: We distributed the survey to physician-educators across Canadaâs 17 medical schools. Respondents were directed to an individualized survey that collected demographic data, physician-educator responses on essential procedural skills, as well as physician-educator opinions on the value of a pre-clerkship procedural training program.
Results: The response rate for this survey was 21% (42 out of 201 distributed surveys were completed). The top 10 most important procedures identified by physician-educators included IV Access, Airway Management, Local anesthesia/field block, Casting, Spontaneous Vaginal Delivery, Testing for STIs, Phlebotomy, Suturing of Lacerations, Nasogastric Tube Insertion, and Venipuncture. Physician-educators supported a pre-clerkship procedural program.
Conclusions: Identifying the most crucial procedural skills is the first step in implementing a competency-based procedural skills training program for Canadian medical students. With the list of essential skills, and the support for physician-educators in developing a pre-clerkship procedural skills curriculum, hopefully there can be future development of formalized curricula.Contexte: Nous avons menĂ© un sondage Ă lâĂ©chelle nationale pour caractĂ©riser les compĂ©tences procĂ©durales canadiennes dans la formation mĂ©dicale de premier cycle. Lâobjectif Ă©tait de reconnaĂźtre les plus importantes procĂ©dures que les Ă©tudiants devaient connaĂźtre Ă la fin de leur formation et dâĂ©valuer les perceptions des cliniciens Ă©ducateurs au sujet de la mise en Ćuvre de leur programme procĂ©dural avant les stages.
Méthodes : Nous avons distribué le sondage à des médecins éducateurs dans les 17 écoles de médecine du Canada. Les répondants ont été dirigés vers un sondage individualisé qui recueillait les données démographiques, les réponses des médecins éducateurs sur les compétences procédurales essentielles, ainsi que les opinions des médecins éducateurs sur la valeur du programme de formation procédurale avant les stages.
RĂ©sultats : Le taux de rĂ©ponse Ă ce sondage a Ă©tĂ© de 21 % (42 des 201 sondages distribuĂ©s ont Ă©tĂ© remplis). Les dix plus importantes procĂ©dures recensĂ©es par les mĂ©decins Ă©ducateurs comprenaient lâaccĂšs IV, lâassistance respiratoire, le bloc anesthĂ©sie locale/champ, le moulage de plĂątre, lâaccouchement spontanĂ© par voie vaginale, les tests dâITS, la phlĂ©botomie, la suture des lacĂ©rations, lâinsertion dâune sonde nasogastrique et la ponction veineuse. Les mĂ©decins Ă©ducateurs soutenaient un programme procĂ©dural avant les stages.
Conclusions : Ătablir les compĂ©tences procĂ©durales les plus essentielles reprĂ©sente la premiĂšre Ă©tape dans la mise en Ćuvre dâun programme de formation dans les compĂ©tences procĂ©durales fondĂ© sur les compĂ©tences pour les Ă©tudiants canadiens en mĂ©decine. Avec la liste de compĂ©tences essentielles et le soutien des mĂ©decins Ă©ducateurs dans le dĂ©veloppement dâun programme de compĂ©tences procĂ©durales avant les stages, nous espĂ©rons quâun programme structurĂ© sera Ă©laborĂ©
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