Resolved Studies of the Dynamics, Star Formation and Chemical Properties of High-Redshift Galaxies

Understanding the physical mechanisms that drive the evolution of galaxies through cosmic time is one of the fundamental pillars of modern-day observational astronomy. Developing a robust theory of galaxy formation enables us to address vital questions connected to the structural and dynamical evolution of galaxies, Why are the kinematic and morphological properties of high-redshift galaxies much more turbulent and irregular than those we see in the local Universe? What drives the galaxies towards the well-ordered, stable systems which ultimately lead to the emergence of the Hubble Sequence? To answer these questions, we must first empirically constrain the fundamental properties (e.g. mass, energy, and angular momentum) of galaxies across cosmic time. This thesis presents an analysis of the dynamics and morphologies of star-forming galaxies from z = 0.8 to z = 3.5. We include both seeing-limited near-infrared integral field spectroscopy observations from the K-band Multi Object Spectrograph (KMOS) as well as adaptive optics integral field observations from the Gemini Northern Integral Field Spectrograph (Gemini-NIFS), the Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) and the OH-Suppressing Infrared Integral Field Spectrograph (OSIRIS). We first analyse the connection between a galaxy’s dynamics and its rest-frame optical morphology by exploiting seeing-limited KMOS observations from the KMOS Galaxy Evolution Survey (KGES) that probe the Hα and [Nii] emission lines in 288 star-forming galaxies at z ∼ 1.5. We combine the integral field data with high-resolution CANDELS HST near-infrared imaging to constrain the morphology of the galaxies in the sample. We identify that low-mass, compact galaxies have lower specific angular momentum whilst more massive disc galaxies have higher angular momentum. At fixed mass, peculiar galaxies have similar levels of angular momentum to that of disc galaxies whilst having higher star formation rate surface densities. We propose that the peculiar morphologies are driven by higher gas fractions leading to a more clumpy interstellar medium. We then explore the chemical abundance properties of ∼700 high-redshift star-forming galaxies that make up the KGES and KROSS surveys. Using the [Nii] / Hα emission line ratio we analyse the connection between gas-phase metallicity, stellar mass and fundamental galaxy properties. We establish that peculiar galaxies have a lower metallicity for a given stellar mass compared to disc and spheroidal systems, which we attribute to their higher gas fractions. The metallicity gradients of the galaxies correlate negatively with stellar mass and positively with specific star formation rate. This agrees with the inside-out model of galaxy formation whereby galaxies first form stars at their centres, enriching the surrounding interstellar medium. On average, we identify flat metallicity gradients which we demonstrate agrees with other studies of high-redshift galaxies and numerical models in which feedback processes are important. Finally, we use high-resolution adaptive optics observations to map out the Hα, [Nii] and [Oiii] nebula emission lines in 34 star-forming galaxies from z = 0.8 to z = 3.5. We explore the evolution of the normalisation of the specific angular momentum – stellar mass plane across ∼ 5Gyr, and constrain the internal distribution of specific angular momentum in each galaxy. We establish that the specific angular momentum becomes less centrally concentrated in galaxies with higher stellar mass due to a combination of stellar feedback and gas accretion. This leads to an evolution in the morphologies of the galaxies towards more a late-type dominated population

Maternal age and other predictors of newborn blood pressure

Objective To investigate perinatal predictors of newborn blood pressure. Study design Among 1059 mothers and their newborn infants participating in Project Viva, a US cohort study of pregnant women and their offspring, we obtained five systolic blood pressure readings on a single occasion in the first few days of life. Using multivariate linear regression models, we examined the extent to which maternal age and other pre- and perinatal factors predicted newborn blood pressure level. Results Mean (SD) maternal age was 32.0 (5.2) years, and mean (SD) newborn systolic blood pressure was 72.6 (9.0) mm Hg. A multivariate model showed that for each 5-year increase in maternal age, newborn systolic blood pressure was 0.8 mm Hg higher (95% CI, 0.2, 1.4). In addition to maternal age, independent predictors of newborn blood pressure included maternal third trimester blood pressure (0.9 mm Hg [95% CI, 0.2, 1.6] for each increment in maternal blood pressure); infant age at which we measured blood pressure (2.4 mm Hg [95% CI 1.7, 3.0] for each additional day of life); and birth weight (2.9 mm Hg [95% CI, 1.6, 4.2] per kg). Conclusions Higher maternal age, maternal blood pressure, and birth weight were associated with higher newborn systolic blood pressure. Whereas blood pressure later in childhood predicts adult hypertension and its consequences, newborn blood pressure may represent different phenomena, such as pre- and perinatal influences on cardiac structure and function. Development of risk for adult cardiovascular disease begins very early in life, even before birth.1 Data are scarce, however, regarding blood pressure in the newborn period, which may reflect pre- and perinatal influences on cardiac structure and function. The few studies that have examined determinants of newborn blood pressure suggest a direct association with birth weight,2.; 3.; 4.; 5.; 6.; 7.; 8.; 9. ; 10. in contrast to the inverse association seen with older infants, children, and adults.11 However, most of these studies have at least one important limitation, such as a relatively small sample size of term newborns, lack of data on potentially confounding variables, and limited data on maternal predictors. Maternal age is of particular interest given the known associations of advanced age with adverse reproductive outcomes, including reduced fertility, preterm birth, impaired fetal growth, multiple birth, and congenital anomalies.12.; 13. ; 14. The additional associations of advanced maternal age with diabetes and hypertension,15. ; 16. with possible diminished uterine vascular and placental function,17. ; 18. and in at least two reports with blood pressure level in childhood and in adolescence19. ; 20. warrant examination of its influence on newborn blood pressure. The purpose of this analysis was to investigate associations of pre- and perinatal factors, including maternal age, with systolic blood pressure level during the first few days of life among members of Project Viva, a cohort study of pregnant women and their children

The cost of a primary care-based childhood obesity prevention intervention

Background: United States pediatric guidelines recommend that childhood obesity counseling be conducted in the primary care setting. Primary care-based interventions can be effective in improving health behaviors, but also costly. The purpose of this study was to evaluate the cost of a primary care-based obesity prevention intervention targeting children between the ages of two and six years who are at elevated risk for obesity, measured against usual care. Methods: High Five for Kids was a cluster-randomized controlled clinical trial that aimed to modify children’s nutrition and TV viewing habits through a motivational interviewing intervention. We assessed visit-related costs from a societal perspective, including provider-incurred direct medical costs, provider-incurred equipment costs, parent time costs and parent out-of-pocket costs, in 2011 dollars for the intervention (n = 253) and usual care (n = 192) groups. We conducted a net cost analysis using both societal and health plan costing perspectives and conducted one-way sensitivity and uncertainty analyses on results. Results: The total costs for the intervention group and usual care groups in the first year of the intervention were $65,643 (95$64,522, $66,842]) and$12,192 (95% CI [$11,393,$13,174]). The mean costs for the intervention and usual care groups were $259 (95$255, $264]) and$63 (95% CI [$59,$69]) per child, respectively, for a incremental difference of $196 (95$191, $202]) per child. Children in the intervention group attended a mean of 2.4 of a possible 4 in-person visits and received 0.45 of a possible 2 counseling phone calls. Provider-incurred costs were the primary driver of cost estimates in sensitivity analyses. Conclusions: High Five for Kids was a resource-intensive intervention. Further studies are needed to assess the cost-effectiveness of the intervention relative to other pediatric obesity interventions. Trial registration ClinicalTrials.gov Identifier: NCT00377767

Mutagenicity of Ochratoxin A and Its Hydroquinone Metabolite in the SupF Gene of the Mutation Reporter Plasmid Ps189

Ochratoxin A (OTA) is a mycotoxin that enhances renal tumor formation in the outer medulla of male rat kidney. Direct DNA damage and subsequent mutagenicity may contribute to these processes. In this study we have determined whether OTA in the absence or presence of activated rat liver microsomes (RLM) or redox-active transition metals (Fe(III) or Cu(II)) causes promutagenic DNA damage in the supF gene of the mutation reporter plasmid pS189 replicating in human Ad293 cells. In addition, we have assessed the mutagenicity of the hydroquinone metabolite (OTHQ) of OTA in the absence or presence of cysteine without added cofactors. Our results show that oxidation of OTA, either by RLM or by transition metal ions, activates OTA to a directly genotoxic mutagen(s). The Fe(III)/OTA system was the most potent mutagen in our experimental system, causing a 32-fold increase in mutant fraction (MF) above the spontaneous control MF. The Cu(II)/OTA system caused a 9-fold increase in MF, while a 6–10-fold increase in MF was observed for OTA in the presence of RLM. The OTHQ metabolite is also mutagenic, especially in the presence of cysteine, in which a 6-fold increase in MF was observed. Our data provide further insight into OTA bioactivation that may account for its in vivo mutagenicity in male rat kidney

Air Pollution Exposure and Abnormal Glucose Tolerance during Pregnancy: The Project Viva Cohort

Background: Exposure to fine particulate matter (PM with diameter ≤ 2.5 μm; PM2.5) has been linked to type 2 diabetes mellitus, but associations with hyperglycemia in pregnancy have not been well studied. Methods: We studied Boston, Massachusetts–area pregnant women without known diabetes. We identified impaired glucose tolerance (IGT) and gestational diabetes mellitus (GDM) during pregnancy from clinical glucose tolerance tests at median 28.1 weeks gestation. We used residential addresses to estimate second-trimester PM2.5 and black carbon exposure via a central monitoring site and spatiotemporal models. We estimated residential traffic density and roadway proximity as surrogates for exposure to traffic-related air pollution. We performed multinomial logistic regression analyses adjusted for sociodemographic covariates, and used multiple imputation to account for missing data. Results: Of 2,093 women, 65 (3%) had IGT and 118 (6%) had GDM. Second-trimester spatiotemporal exposures ranged from 8.5 to 15.9 μg/m3 for PM2.5 and from 0.1 to 1.7 μg/m3 for black carbon. Traffic density was 0–30,860 vehicles/day × length of road (kilometers) within 100 m; 281 (13%) women lived ≤ 200 m from a major road. The prevalence of IGT was elevated in the highest (vs. lowest) quartile of exposure to spatiotemporal PM2.5 [odds ratio (OR) = 2.63; 95% CI: 1.15, 6.01] and traffic density (OR = 2.66; 95% CI: 1.24, 5.71). IGT also was positively associated with other exposure measures, although associations were not statistically significant. No pollutant exposures were positively associated with GDM. Conclusions: Greater exposure to PM2.5 and other traffic-related pollutants during pregnancy was associated with IGT but not GDM. Air pollution may contribute to abnormal glycemia in pregnancy. Citation: Fleisch AF, Gold DR, Rifas-Shiman SL, Koutrakis P, Schwartz JD, Kloog I, Melly S, Coull BA, Zanobetti A, Gillman MW, Oken E. 2014. Air pollution exposure and abnormal glucose tolerance during pregnancy: the Project Viva Cohort. Environ Health Perspect 122:378–383; http://dx.doi.org/10.1289/ehp.130706

Longitudinal Association of Maternal Attempt to Lose Weight During the Postpartum Period and Child Obesity at Age 3 Years

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93678/1/oby.2011.25.pd

A kpc-scale-resolved study of unobscured and obscured star formation activity in normal galaxies at z = 1.5 and 2.2 from ALMA and HiZELS

We present Atacama Large Millimeter/Submillimeter Array (ALMA) continuum observations of a sample of nine star-forming galaxies at redshifts 1.47 and 2.23 selected from the High-z Emission Line Survey (HiZELS). Four galaxies in our sample are detected at high significance by ALMA at a resolution of 0′′.25 at rest-frame 355 μm. Together with the previously observed H α emission, from adaptive optics-assisted integral-field-unit spectroscopy (∼0′′.15 resolution), and F606W and F140W imaging from the Hubble Space Telescope (∼0′′.2 resolution), we study the star formation activity, stellar and dust mass in these high-redshift galaxies at ∼kpc-scale resolution. We find that ALMA detection rates are higher for more massive galaxies (M* > 1010.5 M⊙) and higher [N II]/H α ratios (>0.25, a proxy for gas-phase metallicity). The dust extends out to a radius of 8 kpc, with a smooth structure, even for those galaxies presenting clumpy H α morphologies. The half-light radii (Rdust) derived for the detected galaxies are of the order ∼4.5 kpc, more than twice the size of submillimetre-selected galaxies at a similar redshift. Our global star formation rate estimates – from far-infrared and extinction-corrected H α luminosities – are in good agreement. However, the different morphologies of the different phases of the interstellar medium suggest complex extinction properties of the high-redshift normal galaxies

KURVS: The outer rotation curve shapes and dark matter fractions of z∼1.5z \sim 1.5 star-forming galaxies

We present first results from the KMOS Ultra-deep Rotation Velocity Survey (KURVS), aimed at studying the outer rotation curves shape and dark matter content of 22 star-forming galaxies at $z\sim1.5$. These galaxies represent `typical' star-forming discs at $z \sim 1.5$, being located within the star-forming main sequence and stellar mass-size relation with stellar masses $9.5\leqslant$log$(M_{\star}/\mathrm{M_{\odot}})\leqslant11.5$. We extract individual rotation curves out to 4 times the effective radius, on average, or $\sim 10-15$ kpc. Most rotation curves are flat or rising between three- and six-disc scale radii. Only three objects with dispersion-dominated dynamics ($v_{\rm rot}/\sigma_0\sim0.2$) have declining outer rotation curves at more than 5$\sigma$ significance. After accounting for seeing and pressure support, the nine rotation-dominated discs with $v_{\rm rot}/\sigma_0\geqslant1.5$ have average dark matter fractions of $50 \pm 20\%$ at the effective radius, similar to local discs. Together with previous observations of star-forming galaxies at cosmic noon, our measurements suggest a trend of declining dark matter fraction with increasing stellar mass and stellar mass surface density at the effective radius. Simulated EAGLE galaxies are in quantitative agreement with observations up to log$(M_{\star}R_{\rm eff}^{-2}/\mathrm{M_{\odot}kpc^{-2}}) \sim 9.2$, and over-predict the dark matter fraction of galaxies with higher mass surface densities by a factor of $\sim 3$. We conclude that the dynamics of typical rotationally-supported discs at $z \sim 1.5$ is dominated by dark matter from effective radius scales, in broad agreement with cosmological models. The tension with observations at high stellar mass surface density suggests that the prescriptions for baryonic processes occurring in the most massive galaxies (such as bulge growth and quenching) need to be reassessed.Comment: 23 pages, 9 figures. Resubmitted to MNRAS after addressing the referee's comments. Abstract slightly modified to compile with the arXiv formattin

Cosmic Vine: A z=3.44 Large-Scale Structure Hosting Massive Quiescent Galaxies

We report the discovery of a large-scale structure at z=3.44 revealed by JWST data in the EGS field. This structure, dubbed "Cosmic Vine", consists of 20 galaxies with spectroscopic redshifts at $3.43<z<3.45$ and six galaxy overdensities with consistent photometric redshifts, making up a vine-like structure extending over a ~4x0.2 pMpc^2 area. The two most massive galaxies (M*~10^10.9 Msun) of the Cosmic Vine are found to be quiescent with bulge-dominated morphologies ($B/T>70\%$). Comparisons with simulations suggest that the Cosmic Vine would form a cluster with halo mass >10^14 Msun at z=0, and the two massive galaxies are likely forming the brightest cluster galaxies (BCGs). The results unambiguously reveal that massive quiescent galaxies can form in growing large-scale structures at z>3, thus disfavoring the environmental quenching mechanisms that require a virialized cluster core. Instead, as suggested by the interacting and bulge-dominated morphologies, the two galaxies are likely quenched by merger-triggered starburst or AGN feedback before falling into a cluster core. Moreover, we found that the observed specific star formation rates of massive quiescent galaxies in z>3 dense environments are two orders of magnitude lower than that of the BCGs in the TNG300 simulation. This discrepancy potentially poses a challenge to the models of massive cluster galaxy formation. Future studies comparing a large sample with dedicated cluster simulations are required to solve the problem.Comment: Submitted to A&