The effects of fluctuations in oestrogen and progesterone during the menstrual cycle on glucose homeostasis, energy balance, exercise and premenstrual syndrome

It is widely accepted that the loss of sex hormones after the menopause is strongly linked with cancer, insulin resistance and obesity, with variations in sex hormone concentrations being responsible in part, for the differences reported in energy metabolism and glycaemic control between genders. As such a greater understanding of the effects that oestrogen and progesterone may have on women's health and their potential long term consequences is required. This thesis reports evidence of three studies investigating the effects of oestrogen and progesterone during the menstrual cycle on glucose and insulin response, energy expenditure, substrate oxidation and premenstrual syndrome (PMS). The aim of the first study was to investigate glucose and insulin responses to a 75g glucose load during different phases of the menstrual cycle. Venous blood samples for baseline measurements of oestradiol and progesterone were collected every other week day from eighteen regularly menstruating women for one complete menstrul cycle. An oral glucose tolerance test (OGIT, 75g glucose) was performed on three separate days during the next complete menstrual cycle. The results report an increase in glucose area under the curve (AUC) and insulin AUC during the luteal phase (P<0.05) compared to the menstrual and follicular phase, but no significant differences in insulin sensitivity between phases. The findings indicate that both oestrogen and progesterone during the luteal phase may affect glycaemic response and this potentially has significant implications for the development of type 2 diabetes over prolonged periods of time. The second study investigated energy expenditure and substrate oxidation at rest and during a 30 minute moderate intensity walking exercise within the three phases of the menstrual cycle. Sex hormone concentrations were collected in the same manner as study 1. Nineteen women undertook resting measures and ten for exercise. The study reports a decrease in carbohydrate (CHO) oxidation (P<0.05) and a marginal increase in fat oxidation (P=0.06) during the follicular phase at rest, with no difference in energy expenditure at rest. No difference in energy expenditure or substrate oxidation between phases was reported during exercise. The results indicate high oestrogen concentrations during the follicular phase only may mediate the changes in substrate oxidation response reported at rest. I The final study investigated the effects of a 12 week moderate intensity exercise intervention on symptoms of PMS, quality of life and dietary intake and determined whether any such effect was associated with changes in oestrogen and progesterone concentrations in a randomised control trial. Twenty-five sedentary women, identified as suffering from PMS symptoms, were recruited to the trial spanning four menstrual cycles, the first serving as a baseline followed by three cycles of intervention. Participants were randomly assigned to either an exercise (EX) group (n= l 3), which involved three supervised 30-minute moderate­ intensity (70-80% HR max) treadmill walking exercise sessions per week, or to a control (CON) group (n=12), which involved attending a 90-minute, one-to-one meeting once per week with the investigator. The results report a reduction in PMS symptoms following the exercise intervention (P<0.05), with no differences in the control (CON) group. Averaged dietary intake over the three intervention cycles reports a decrease in CHO intake (% total energy intake, TEI) during the luteal phase, compared to the menstrual (45.5% vs. 50. l%) and follicular (45.5 vs. 49.9%) phases in the EX group, with no difference in the CON group. No significant difference was reported in overall energy intake in either group. In addition, no significant difference was reported in plasma oestrogen and progesterone concentrations over the four cycles in either group (EX and CON). The findings indicate that the exercise regime reduces PMS symptoms and CHO intake (%TEI), but that these are not mediated in response to changes in oestrogen and progesterone hormone concentrations. As such exercise may therefore be an effective symptom management tool for women suffering with PMS. Further studies are essential to determine the exact duration and intensity required for the most effective symptom relief. The results reported in this thesis provide evidence that the circulating reproductive hormones oestrogen and progesterone during the menstrual cycle have significant implications for energy regulation, glycaemic control and women suffering from PMS. As such, both hormones need to be investigated further in larger research studies to determine their potential long-term adverse effects on health and well-being in women

Who Received Loans? Home Owners\u27 Loan Corporation Lending and Discrimination in Philadelphia in the 1930\u27s

The lending record of the Home Owners’ Loan Corporation (HOLC) has received little attention compared with HOLC’s residential security maps. Specifically, the extent to which HOLC practiced racial and ethnic discrimination in the process of making and servicing more than a million loans to homeowners during the Depression has not been carefully examined. Using primary sources including HOLC publications, newspaper articles, 1930 census data, and mortgage records from Philadelphia, this research shows that HOLC did make loans to African Americans, Jews, and immigrants. Evidence suggests, however, that HOLC supported racial segregation in the process of reselling properties acquired through foreclosure

Why Social Work Needs Mapping

Relative to other fields, social work has been slow to adopt geographic information systems (GIS) as a tool for research and practice. This paper argues that GIS can benefit social work by: (1) continuing and strengthening the social survey tradition; (2) providing a framework for understanding human behavior; (3) identifying community needs and assets; (4) improving the delivery of social services; and (5) empowering communities and traditionally disenfranchised groups. Examples from a social work course on GIS and published social work research help illustrate these points. The paper concludes by considering the ways that social work can contribute to the development of GIS

Spatial Analysis of Historical Redlining: A Methodological Explanation

Despite widespread belief that redlining contributed to disinvestment in cities, there has been little empirical analysis of historical lending patterns. The lack of appropriate data and clear definitions of redlining has contributed to this void. This article reviews definitions and methods that have emerged from research on lending in recent years and considers how they can be applied to research on historical redlining. Address-level mortgage data from Philadelphia from the 1940s are analyzed using spatial regression, “hot spot” analysis, and surface interpolation. Employing multiple definitions of redlining that focus on process and outcome, as well as spatial and statistical relationships in lending, the analyses result in a series of map layers that indicate where redlining may have occurred. In addition to providing some evidence of lending discrimination, this article promotes an explicitly spatial view of redlining that has conceptual and methodological implications for research on contemporary and historical redlining

The Atomic Physics Underlying the Spectroscopic Analysis of Massive Stars and Supernovae

We have developed a radiative transfer code, CMFGEN, which allows us to model the spectra of massive stars and supernovae. Using CMFGEN we can derive fundamental parameters such as effective temperatures and surface gravities, derive abundances, and place constraints on stellar wind properties. The last of these is important since all massive stars are losing mass via a stellar wind that is driven from the star by radiation pressure, and this mass loss can substantially influence the spectral appearance and evolution of the star. Recently we have extended CMFGEN to allow us to undertake time-dependent radiative transfer calculations of supernovae. Such calculations will be used to place constraints on the supernova progenitor, to place constraints on the supernova explosion and nucleosynthesis, and to derive distances using a physical approach called the "Expanding Photosphere Method". We describe the assumptions underlying the code and the atomic processes involved. A crucial ingredient in the code is the atomic data. For the modeling we require accurate transition wavelengths, oscillator strengths, photoionization cross-sections, collision strengths, autoionization rates, and charge exchange rates for virtually all species up to, and including, cobalt. Presently, the available atomic data varies substantially in both quantity and quality.Comment: 8 pages, 2 figures, Accepted for publication in Astrophysics & Space Scienc

Redlining and the Homeowners\u27 Loan Corporation

This article analyzes the impact of the residential security maps created by the Home Owners’Loan Corporation (HOLC) during the 1930s on residential mortgages in Philadelphia. Researchers have consistently argued that HOLC caused redlining and disinvestment in U.S. cities by sharing its color-coded maps. Geographic information systems and spatial statistical models were used to analyze address-level mortgage data from Philadelphia to determine if areas with worse grades actually had less access to residential mortgage credit as a result. Findings indicate that the grades on HOLC’s map do not explain differences in lending patterns with the exception of interest rates, which were higher in areas colored red. Archival material and journal articles from the 1930s also reveal that lenders were avoiding areas colored red before HOLC made its maps, that HOLC’s maps were not widely distributed, and that lenders had other sources of information about real estate risk levels

Residential Security Maps and Neighborhood Appraisals. The Homeowners\u27 Loan Corporation and the Case of Philadelphia

At the request of the Home Loan Bank Board, the Home Owners’ Loan Corporation (HOLC) created color-coded maps for cities across the country between 1935 and 1940 that indicated risk levels for long-term real estate investment. Involvement in this City Survey Program marked a departure from the original mission of HOLC to provide new mortgages on an emergency basis to homeowners at risk of losing their homes during the Depression. This article considers why HOLC made these maps, how HOLC created them, and what the basis was for the grades on the maps. Geographic information systems and spatial regression models are used to show that racial composition was a significant predictor of map grades, controlling for housing characteristics

Construction of Cell-Resistant Surfaces by Immobilization of Poly(ethylene glycol) on Gold

Considerable effort has been expended in efforts to create surfaces that resist the adsorption of proteins and cells for biomedical applications. The majority of such work has focused on surfaces constructed from bulk polymers or thin polymer films. However, the fabrication of surfaces via self-assembled monolayers (SAMs) has attracted considerable interest because of the robustness, versatility, and wide-ranging applicability of these materials. SAMs are particularly appealing for biological systems where well-defined surface chemistries can be created to facilitate coupling, biorecognition, or cell adhesion along with a host of other applications in biochemistry and biotechnology

X-ray, UV and optical analysis of supergiants: ϵ\epsilon Ori

We present a multi-wavelength (X-ray to optical) analysis, based on non-local thermodynamic equilibrium photospheric+wind models, of the B0 Ia-supergiant: $\epsilon$~Ori. The aim is to test the consistency of physical parameters, such as the mass-loss rate and CNO abundances, derived from different spectral bands. The derived mass-loss rate is $\dot{M}/\sqrt{f_\infty}\sim$1.6$\times$10$^{-6}$ M$_\odot$ yr$^{-1}$ where $f_\infty$ is the volume filling factor. However, the S IV $\lambda\lambda$1062,1073 profiles are too strong in the models; to fit the observed profiles it is necessary to use $f_\infty<$0.01. This value is a factor of 5 to 10 lower than inferred from other diagnostics, and implies $\dot{M} \lesssim1 \times 10^{-7}$ M$_\odot$ yr$^{-1}$. The discrepancy could be related to porosity-vorosity effects or a problem with the ionization of sulfur in the wind. To fit the UV profiles of N V and O VI it was necessary to include emission from an interclump medium with a density contrast ($\rho_{cl}/\rho_{ICM}$) of $\sim$100. X-ray emission in H-He like and Fe L lines was modeled using four plasma components located within the wind. We derive plasma temperatures from $1 \times 10^{6}$ to $7\times 10^{6}$ K, with lower temperatures starting in the outer regions (R$_0\sim$3-6 R$_*$), and a hot component starting closer to the star (R$_0\lesssim$2.9 R$_*$). From X-ray line profiles we infer $\dot{M} <\, 4.9\times10^{-7}$ M$_\odot$ yr$^{-1}$. The X-ray spectrum ($\geq$0.1 kev) yields an X-ray luminosity $L_{\rm X}\sim 2.0\times10^{-7} L_{\rm bol}$, consistent with the superion line profiles. X-ray abundances are in agreement with those derived from the UV and optical analysis: $\epsilon$ Ori is slightly enhanced in nitrogen and depleted in carbon and oxygen, evidence for CNO processed material.Comment: 33 pages, 25 figures. Accepted for publication in MNRA

The qWR star HD 45166. II. Fundamental stellar parameters and evidence of a latitude-dependent wind

The enigmatic object HD 45166 is a qWR star in a binary system with an orbital period of 1.596 day, and presents a rich emission-line spectrum in addition to absorption lines from the companion star (B7 V). As the system inclination is very small (i=0.77 +- 0.09 deg), HD 45166 is an ideal laboratory for wind-structure studies. The goal of the present paper is to determine the fundamental stellar and wind parameters of the qWR star. A radiative transfer model for the wind and photosphere of the qWR star was calculated using the non-LTE code CMFGEN. The wind asymmetry was also analyzed using a recently-developed version of CMFGEN to compute the emerging spectrum in two-dimensional geometry. The temporal-variance spectrum (TVS) was calculated for studying the line-profile variations. Abundances, stellar and wind parameters of the qWR star were obtained. The qWR star has an effective temperature of Teff=50000 +- 2000 K, a luminosity of log(L/Lsun)=3.75 +- 0.08, and a corresponding photospheric radius of Rphot=1.00 Rsun. The star is helium-rich (N(H)/N(He) = 2.0), while the CNO abundances are anomalous when compared either to solar values, to planetary nebulae, or to WR stars. The mass-loss rate is Mdot = 2.2 . 10^{-7} Msun/yr, and the wind terminal velocity is vinf=425 km/s. The comparison between the observed line profiles and models computed under different latitude-dependent wind densities strongly suggests the presence of an oblate wind density enhancement, with a density contrast of at least 8:1 from equator to pole. If a high velocity polar wind is present (~1200 km/s), the minimum density contrast is reduced to 4:1. The wind parameters determined are unusual when compared to O-type stars or to typical WR stars. (abridged)Comment: 16 pages, 13 figures, accepted for publication in A&