Breaking the Glass Ceiling: Views of Women from the Second-Wave Feminist Movement

This is a qualitative study of the career perspectives of early female leaders in Canada whose careers emerged from the second-wave feminist movement and who ascended to executive leadership positions. Using a discourse analytic lens, we analyze their perspectives on women's limited presence in executive leadership roles. The research participants suggested that women lacked the necessary resilience or personality; women lacked requisite political skills; affirmative action policies have hindered women's career advancement; and women have been unable to put their careers over family in the way that is required for executive leadership. The views expressed by these participants are often contrarian to current thinking about gender and leadership but underline the gendered nature of persistent barriers to executive leadership past and present. Cet article est une étude qualitative des perspectives de carrière des premières femmes leaders au Canada qui ont vu leurs carrières démarrer à la faveur du mouvement féministe de la deuxième vague et qui ont accédé à des postes de direction. En recourant à l'analyse du discours, ses auteurs examinent les perspectives des femmes sur la présence limitée des femmes dans les postes de direction. Le dépouillement des données recueillies permet de constater que pour les participantes, les femmes n'ont pas la résilience ou la personnalité nécessaire; les femmes n'ont pas les compétences politiques requises; les politiques liées à la discrimination positive entravent l'avancement professionnel des femmes; et les femmes ne sont pas en mesure de faire passer leur carrière avant leur famille, de la manière requise pour occuper des postes de direction. Les points de vue exprimés par ces participantes vont souvent à l'encontre de la pensée actuelle sur le genre et le leadership, mais soulignent la nature sexuée des obstacles persistants auxquels les femmes font face ou ont fait face pour accéder au leadership exécutif

Probing the Pulsar Wind Nebula of PSR B0355+54

We present XMM-Newton and Chandra X-ray observations of the middle-aged radio pulsar PSR B0355+54. Our X-ray observations reveal emission not only from the pulsar itself, but also from a compact diffuse component extending ~50'' in the opposite direction to the pulsar's proper motion. There is also evidence for the presence of fainter diffuse emission extending ~5' from the point source. The compact diffuse feature is well-fitted with a power-law, the index of which is consistent with the values found for other pulsar wind nebulae. The morphology of the diffuse component is similar to the ram-pressure confined pulsar wind nebulae detected for other sources. The X-ray emission from the pulsar itself is described well by a thermal plus power-law fit, with the thermal emission most likely originating in a hot polar cap.Comment: 9 pages (uses emulateapj.cls), 8 figures, 2 tables, accepted for publication in Ap

Approximate N3^{3}LO Parton Distribution Functions with Theoretical Uncertainties: MSHT20aN3^3LO PDFs

We present the first global analysis of parton distribution functions (PDFs) at approximate N$^{3}$LO in the strong coupling constant $\alpha_{s}$, extending beyond the current highest NNLO achieved in PDF fits. To achieve this, we present a general formalism for the inclusion of theoretical uncertainties from missing higher orders (MHOs) into a PDF fit. We demonstrate how using the currently available knowledge surrounding the next highest order (N$^{3}$LO) in $\alpha_{s}$ can provide consistent, justifiable and explainable approximate N$^{3}$LO (aN$^{3}$LO) PDFs, including estimates for missing higher order uncertainties (MHOUs). Specifically, we approximate the splitting functions, transition matrix elements, coefficient functions and $K$-factors for multiple processes to N$^{3}$LO. Crucially, these are constrained to be consistent with the wide range of already available information about N$^{3}$LO to match the complete result at this order as accurately as possible. Using this approach we perform a fully consistent approximate N$^{3}$LO global fit within the MSHT framework. This relies on an expansion of the Hessian procedure used in previous MSHT fits to allow for sources of theoretical uncertainties. These are included as nuisance parameters in a global fit, controlled by knowledge and intuition based prior distributions. We analyse the differences between our aN$^{3}$LO PDFs and the standard NNLO PDF set, and study the impact of using aN$^{3}$LO PDFs on the LHC production of a Higgs boson at this order. Finally, we provide guidelines on how these PDFs should be be used in phenomenological investigations.Comment: 150 pages, 48 figures, 20 tables. Updated LHAPDF Grids available which include a correction of a minor bug in the non-singlet splitting function leading to very small changes in fit quality and PDFs, but with no significant changes to any results or conclusion

Helium Nova on a Very Massive White Dwarf -- A Light Curve Model of V445 Puppis (2000) Revised

V445 Pup (2000) is a unique object identified as a helium nova. Color indexes during the outburst are consistent with those of free-free emission. We present a free-free emission dominated light curve model of V445 Pup on the basis of the optically thick wind theory. Our light curve fitting shows that (1) the white dwarf (WD) mass is very massive (M_WD \gtrsim 1.35 M_\sun), and (2) a half of the accreted matter remains on the WD, both of which suggest that the increasing WD mass. Therefore, V445 Pup is a strong candidate of Type Ia supernova progenitor. The estimated distance to V445 Pup is now consistent with the recent observational suggestions, 3.5 < d < 6.5 kpc. A helium star companion is consistent with the brightness of m_v=14.5 mag just before the outburst, if it is a little bit evolved hot (\log T (K) \gtrsim 4.5) star with the mass of M_He \gtrsim 0.8 M_\sun. We then emphasize importance of observations in the near future quiescent phase after the thick circumstellar dust dissipates away, especially its color and magnitude to specify the nature of the companion star. We have also calculated helium ignition masses for helium shell flashes against various helium accretion rates and discussed the recurrence period of helium novae.Comment: 8 pages including 12 figures, to appear in Ap

The early and late-time spectral and temporal evolution of GRB 050716

We report on a comprehensive set of observations of Gamma Ray Burst 050716, detected by the Swift satellite and subsequently followed-up rapidly in X-ray, optical and near infra-red wavebands. The prompt emission is typical of long-duration bursts, with two peaks in a time interval of T90 = 68 seconds (15 - 350 keV). The prompt emission continues at lower flux levels in the X-ray band, where several smaller flares can be seen, on top of a decaying light curve that exhibits an apparent break around 220 seconds post trigger. This temporal break is roughly coincident with a spectral break. The latter can be related to the extrapolated evolution of the break energy in the prompt gamma-ray emission, and is possibly the manifestation of the peak flux break frequency of the internal shock passing through the observing band. A possible 3 sigma change in the X-ray absorption column is also seen during this time. The late-time afterglow behaviour is relatively standard, with an electron distribution power-law index of p = 2 there is no noticable temporal break out to at least 10 days. The broad-band optical/nIR to X-ray spectrum indicates a redshift of z ~> 2 for this burst, with a host-galaxy extinction value of E(B-V) ~ 0.7 that prefers an SMC-like extinction curve.Comment: Accepted to MNRAS. 8 pages, 5 figure

XMM-Newton Observations of PSR B1706-44

We report on the XMM-Newton observations of the young, 102 ms pulsar PSR B1706-44. We have found that both a blackbody plus power-law and a magnetized atmospheric model plus power-law provide an excellent fit to the EPIC spectra. The two scenarios are therefore indistinguishable on a statistical basis, although we are inclined to prefer the latter on physical grounds. In this case, assuming a source distance of ~2.3 kpc, the size of the region responsible for the thermal emission is R~13 km, compatible with the surface of a neutron star. A comparison of the surface temperature of PSR B1706-44 obtained from this fit with cooling curves favor a medium mass neutron star with M~1.45 solar masses or M~1.59 solar masses, depending on two different models of proton superfluidity in the interior. The large collecting area of XMM-Newton allows us to resolve a substructure in the broad soft X-ray modulation detected by Chandra, revealing the presence of two separate peaks with pulsed fractions of 7 +/- 4% and 15 +/- 3%, respectively.Comment: 21 pages, 5 figures, 2 tables, accepted for publication in Ap

Low-energy total diet replacement intervention in patients with type 2 diabetes mellitus and obesity treated with insulin: a randomized trial

OBJECTIVES: The management of patients with long-standing type 2 diabetes and obesity receiving insulin therapy (IT) is a substantial clinical challenge. Our objective was to examine the effect of a low-energy total diet replacement (TDR) intervention versus standardized dietetic care in patients with long-standing type 2 diabetes and obesity receiving IT. RESEARCH DESIGN AND METHODS: In a prospective randomized controlled trial, 90 participants with type 2 diabetes and obesity receiving IT were assigned to either a low-energy TDR (intervention) or standardized dietetic care (control) in an outpatient setting. The primary outcome was weight loss at 12 months with secondary outcomes including glycemic control, insulin burden and quality of life (QoL). RESULTS: Mean weight loss at 12 months was 9.8 kg (SD 4.9) in the intervention and 5.6 kg (SD 6.1) in the control group (adjusted mean difference -4.3 kg, 95% CI -6.3 to 2.3, p<0.001). IT was discontinued in 39.4% of the intervention group compared with 5.6% of the control group among completers. Insulin requirements fell by 47.3 units (SD 36.4) in the intervention compared with 33.3 units (SD 52.9) in the control (-18.6 units, 95% CI -29.2 to -7.9, p=0.001). Glycated Hemoglobin (HbA1c) fell significantly in the intervention group (4.7 mmol/mol; p=0.02). QoL improved in the intervention group of 11.1 points (SD 21.8) compared with 0.71 points (SD 19.4) in the control (8.6 points, 95% CI 2.0 to 15.2, p=0.01). CONCLUSIONS: Patients with advanced type 2 diabetes and obesity receiving IT achieved greater weight loss using a TDR intervention while also reducing or stopping IT and improving glycemic control and QoL. The TDR approach is a safe treatment option in this challenging patient group but requires maintenance support for long-term success. TRIAL REGISTRATION NUMBER: ISRCTN21335883

Using Small-Area Analysis to Estimate County-Level Racial Disparities in Obesity Demonstrating the Necessity of Targeted Interventions

Data on the national and state levels is often used to inform policy decisions and strategies designed to reduce racial disparities in obesity. Obesity-related health outcomes are realized on the individual level, and policies based on state and national-level data may be inappropriate due to the variations in health outcomes within and between states. To examine county-level variation of obesity within states, we use a small-area analysis technique to fill the void for county-level obesity data by race. Five years of Behavioral Risk Factor Surveillance System data are used to estimate the prevalence of obesity by county, both overall and race-stratified. A modified weighting system is used based on demographics at the county level using 2010 census data. We fit a multilevel reweighted regression model to obtain county-level prevalence estimates by race. We compare the distribution of prevalence estimates of non-Hispanic Blacks to non-Hispanic Whites. For 25 of the 26 states included in our analysis there is a statistically significant difference between within-state county-level average obesity prevalence rates for non-Hispanic Whites and non-Hispanic Blacks. This study provides information needed to target disparities interventions and resources to the local areas with greatest need; it also identifies the necessity of doing so