Abstract
We present the ∼800 star formation rate maps for the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey based on H α emission maps, corrected for dust attenuation via ...the Balmer decrement, that are included in the SAMI Public Data Release 1. We mask out spaxels contaminated by non-stellar emission using the O iii/H β, N ii/H α, S ii/H α, and O i/H α line ratios. Using these maps, we examine the global and resolved star-forming main sequences of SAMI galaxies as a function of morphology, environmental density, and stellar mass. Galaxies further below the star-forming main sequence are more likely to have flatter star formation profiles. Early-type galaxies split into two populations with similar stellar masses and central stellar mass surface densities. The main-sequence population has centrally concentrated star formation similar to late-type galaxies, while galaxies >3σ below the main sequence show significantly reduced star formation most strikingly in the nuclear regions. The split populations support a two-step quenching mechanism, wherein halo mass first cuts off the gas supply and remaining gas continues to form stars until the local stellar mass surface density can stabilize the reduced remaining fuel against further star formation. Across all morphologies, galaxies in denser environments show a decreased specific star formation rate from the outside in, supporting an environmental cause for quenching, such as ram-pressure stripping or galaxy interactions.
We examine the kinematic morphology of early-type galaxies (ETGs) in eight galaxy clusters in the Sydney-AAO Multi-object Integral-field spectrograph Galaxy Survey. The clusters cover a mass range of ...and we measure spatially resolved stellar kinematics for 315 member galaxies with stellar masses within 1 R200 of the cluster centers. We calculate the spin parameter, λR, and use this to classify the kinematic morphology of the galaxies as fast or slow rotators (SRs). The total fraction of SRs in the ETG population is FSR = 0.14 0.02 and does not depend on host cluster mass. Across the eight clusters, the fraction of SRs increases with increasing local overdensity. We also find that the slow-rotator fraction increases at small clustercentric radii (Rcl < 0.3 R200), and note that there is also an increase in the slow-rotator fraction at Rcl ∼ 0.6 R200. The SRs at these larger radii reside in the cluster substructure. We find that the strongest increase in the slow-rotator fraction occurs with increasing stellar mass. After accounting for the strong correlation with stellar mass, we find no significant relationship between spin parameter and local overdensity in the cluster environment. We conclude that the primary driver for the kinematic morphology-density relationship in galaxy clusters is the changing distribution of galaxy stellar mass with the local environment. The presence of SRs in the substructure suggests that the cluster kinematic morphology-density relationship is a result of mass segregation of slow-rotating galaxies forming in groups that later merge with clusters and sink to the cluster center via dynamical friction.
Given that regionalization of extremely preterm births (EPTBs) is associated with improved infant outcomes, we assessed between-hospital variation in EPTB stratified by hospital level of neonatal ...care, and determined the proportion of variance explained by differences in maternal and hospital factors.
We assessed 7,046,253 births in California from 1997 to 2011, using hospital discharge, birth, and death certificate data. We estimated the association between maternal and hospital factors and EPTB using multivariable regression, calculated hospital-specific EPTB frequencies, and estimated between-hospital variances and median odds ratios, stratified by hospital level of care.
Hospital frequencies of EPTB ranged from 0% to 2.5%. Between-hospital EPTB frequencies varied substantially, despite stratifying by hospital level of care and accounting for confounding factors.
Our results demonstrate differences in EPTBs among hospitals with level 1 and 2 neonatal care, an area to target for future research and quality improvement.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
To evaluate the relationship between prenatal and postnatal inflammation-related risk factors and severe retinopathy of prematurity (ROP).
The study included infants born <30 weeks in California from ...2007 to 2011. Multivariable log-binomial regression was used to assess the association between prenatal and postnatal inflammation-related exposures and severe ROP, defined as stage 3-5 or surgery for ROP.
Of 14,816 infants, 10.8% developed severe ROP. Though prenatal inflammation-related risk factors were initially associated with severe ROP, after accounting for the effect of these risk factors on gestational age at birth through mediation analysis, the association was non-significant (P = 0.6). Postnatal factors associated with severe ROP included prolonged oxygen exposure, sepsis, intraventricular hemorrhage, and necrotizing enterocolitis.
Postnatal inflammation-related factors were associated with severe ROP more strongly than prenatal factors. The association between prenatal inflammation-related factors and ROP was explained by earlier gestational age in infants exposed to prenatal inflammation.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
We investigate the energy sources of random turbulent motions of ionized gas from H α emission in eight local star-forming galaxies from the Sydney-AAO Multi-object Integral field ...spectrograph (SAMI) Galaxy Survey. These galaxies satisfy strict pure star-forming selection criteria to avoid contamination from active galactic nuclei (AGNs) or strong shocks/outflows. Using the relatively high spatial and spectral resolution of SAMI, we find that – on sub-kpc scales, our galaxies display a flat distribution of ionized gas velocity dispersion as a function of star formation rate (SFR) surface density. A major fraction of our SAMI galaxies shows higher velocity dispersion than predictions by feedback-driven models, especially at the low SFR surface density end. Our results suggest that additional sources beyond star formation feedback contribute to driving random motions of the interstellar medium in star-forming galaxies. We speculate that gravity, galactic shear and/or magnetorotational instability may be additional driving sources of turbulence in these galaxies.
The impact of human milk use on racial/ethnic disparities in necrotizing enterocolitis (NEC) incidence is unknown.
Trends in NEC incidence and human milk use at discharge were evaluated by ...race/ethnicity among 47,112 very low birth weight infants born in California from 2008 to 2017. We interrogated the association between race/ethnicity and NEC using multilevel regression analysis, and evaluated the effect of human milk use at discharge on the relationship between race/ethnicity and NEC using mediation analysis.
Annual NEC incidence declined across all racial/ethnic groups from an aggregate average of 4.8% in 2008 to 2.6% in 2017. Human milk use at discharge increased over the time period across all racial groups, and non-Hispanic (NH) black infants received the least human milk each year. In multivariable analyses, Hispanic ethnicity (odds ratio (OR) 1.27, 95% confidence interval (CI) 1.02-1.57) and Asian or Pacific Islander race (OR 1.35, 95% CI 1.01-1.80) were each associated with higher odds of NEC, while the association of NH black race with NEC was attenuated after adding human milk use at discharge to the model. Mediation analysis revealed that human milk use at discharge accounted for 22% of the total risk of NEC in non-white vs. white infants, and 44% in black vs. white infants.
Although NEC incidence has declined substantially over the past decade, a sizable racial/ethnic disparity persists. Quality improvement initiatives augmenting human milk use may further reduce the incidence of NEC in vulnerable populations.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
BACKGROUND
Understanding factors that impact tissue oxygen extraction may guide red blood cell (RBC) transfusion decision making in preterm infants. Our objective was to assess the influence of ...enteral feeding and anemia on cerebral and mesenteric oxygen saturation (Csat and Msat) and fractional tissue oxygen extraction (cFTOE and mFTOE) over the entire time course of RBC transfusion.
STUDY DESIGN AND METHODS
Preterm, very low‐birth‐weight infants receiving RBC transfusions at a single center were enrolled. Near‐infrared spectroscopy sensors measured Csat and Msat levels from an hour before transfusion to 24 hours after. During this period, changes in Csat, Msat, cFTOE, and mFTOE were described, and their association with enteral feeding status and pretransfusion degree of anemia were assessed using generalized estimating equations.
RESULTS
RBC transfusion data from 31 preterm infants were included. Infants receiving enteral feeds exhibited lower pretransfusion Msat. Infants with pretransfusion hematocrit greater than 30% exhibited higher pretransfusion Csat and lower pretransfusion cFTOE. Such differences in baseline measurements persisted through 24 hours after transfusion. However, no statistically significant differences in oxygenation measures over time by enteral feeding or anemia status were identified.
CONCLUSION
Compared to NPO, enteral feeding was associated with lower Msat; anemia (hematocrit ≤30%) was associated with lower Csat and higher cFTOE. Over the time course of RBC transfusion, trajectories of Csat, Msat, cFTOE and mFTOE did not differ by enteral feeding or anemia status.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Objective To estimate the influence of prior oral contraceptive pill (OCP) use on future diagnosis of endometriosis in young women. Design Prospective cohort study, the Australian Longitudinal Study ...on Women’s Health. Setting Community-based sample. Patient(s) 9,585 women age 18–23 at study onset. Intervention(s) None. Main Outcome Measure(s) Risk of self-reported endometriosis estimated with Cox proportional-hazards regression with time-dependent covariates. Result(s) Compared with never users, endometriosis hazard ratios in nulliparous women with <5 years and ≥5 years of OCP use (preceding diagnosis) were 1.8 (95% CI, 1.30–2.53) and 2.3 (95% CI, 1.59–3.40), respectively. Similar risk was seen in both women reporting infertility and unsure fertility. In parous women with <5 years of use, the hazard ratio for endometriosis was 0.41 (95% CI, 0.15–0.56) and for ≥5 years of use was 0.45 (95% CI, 0.16–1.23). Women reporting early noncontraceptive OCP use had a twofold higher risk (odds ratio 2.07; 95% CI, 1.72–2.51). Conclusion(s) Prior OCP exposure reduces the risk of diagnosis of endometriosis in parous women but increases it among nulliparous women; these associations appear unaffected by fertility status. An increased risk of endometriosis diagnosis seen in women reporting early noncontraceptive OCP use may explain some of the positive OCP risk seen in nulliparous women.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the USA, the mortality rate from traffic injury is higher in rural and in southern regions, for reasons that are not well understood.
For 1754 (56%) of the 3142 US counties, we obtained data ...allowing for separation of the deaths/population rate into deaths/injury, injuries/crash, crashes/exposure and exposure/population, with exposure measured as vehicle miles travelled. A 'decomposition method' proposed by Li and Baker was extended to study how the contributions of these components were affected by three measures of rural location, as well as southern location.
The method of Li and Baker extended without difficulty to include non-binary effects and multiple exposures. Deaths/injury was by far the most important determinant in the county-to-county variation in deaths/population, and accounted for the greatest portion of the rural/urban disparity. After controlling for the rural effect, injuries/crash accounted for most of the southern/northern disparity.
The increased mortality rate from traffic injury in rural areas can be attributed to the increased probability of death given that a person has been injured, possibly due to challenges faced by emergency medical response systems. In southern areas, there is an increased probability of injury given that a person has crashed, possibly due to differences in vehicle, road, or driving conditions.
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