Heat Transfer to Freon 12 near the Critical State in a Thermal Syphon Type Apparatus

Engineering and Technology Managemen

A Precise Estimate of the Radius of HD 149026b

We present Spitzer 8 micron transit observations of the extrasolar planet system HD 149026. At this wavelength, transit light curves are weakly affected by stellar limb-darkening, allowing for a simpler and more accurate determination of planetary parameters. We measure a planet-star radius ratio of R_p/R_s = 0.05158 +/- 0.00077, and in combination with ground-based data and independent constraints on the stellar mass and radius, we derive an orbital inclination of i = 85.4 +0.9/-0.8 deg. and a planet radius of 0.755 +/- 0.040 Jupiter radii. These measurements further support models in which the planet is greatly enriched in heavy elements.Comment: To appear in the Proceedings of the 253rd IAU Symposium: "Transiting Planets", May 2008, Cambridge, M

New perspectives on language and gender: Linguistic prescription and compliance in call centres

Despite a shift to service-based economies, male-dominated, high-status workplaces have been the predominant focus of research into language and gender in the workplace. This study redresses this shortcoming by considering one female-dominated, low-status, highly regimented workplace that is emblematic of the globalized service economy: call centres. Drawing on 187 call centre service interactions, institutional documents, interviews, and observations from call centres in two national contexts, the study employs an innovative combination of quantitative and qualitative discourse-analytic techniques to compare rule compliance of male and female workers. Female agents in both national contexts are found to comply more with the linguistic prescriptions despite managers and agents emphatically denying the relevance of gender. The study offers a new perspective on language and gender, pointing to the need to expand the methodologies and theories currently favoured to understand how language perpetuates occupational segregation in twenty-first-century workplaces

Observational study of the association of first insulin type in uncontrolled type 2 diabetes with macrovascular and microvascular disease

<p>Aims: To compare the risk of vascular disease, HbA1c and weight change, between first prescribed insulins in people with type 2 diabetes.</p> <p>Methods: People included in THIN United Kingdom primary care record database who began insulin (2000–2007) after poor control on oral glucose-lowering agents (OGLD) were grouped by the number of OGLDs in their treatment regimen immediately before starting insulin (n = 3,485). Within OGLD group, Cox regression compared macrovascular (all-cause mortality, myocardial infarction, acute coronary syndrome and stroke) and microvascular disease (peripheral neuropathy, nephropathy, and retinopathy) between insulin type (basal, pre-mix or Neutral Protamine Hagedorn, NPH) while ANCOVAs compared haemoglobin A1c (HbA1c) and weight change.</p> <p>Results: Mean follow-up was 3.6 years. Rates of incident macrovascular events were similar when basal insulin was compared to pre-mix or NPH, adjusted hazard ratio versus basal: pre-mix 1.08 (95% CI 0.73, 1.59); NPH 1.00 (0.63, 1.58) after two OGLDs, and pre-mix 0.97 (0.46, 2.02); NPH 0.77 (0.32, 1.86) after three OGLDs. An increased risk of microvascular disease in NPH versus basal after 3 OGLDs, adjusted hazard ratio1.87 (1.04, 3.36), was not seen after two agents or in comparisons of basal and pre-mix. At one year, after two OGLDs, weight increase was less with basal compared with pre-mix. After three OGLDs, mean HbA1c had reduced less in basal versus pre-mix or NPH at 6–8 and at 9–11 months, and versus pre-mix at 12–14 months.</p> <p>Conclusion: We found no difference in the risk of macrovascular events between first insulins in the medium term when started during poor glycaemia control. The increased risk of microvascular events with NPH warrants further study. In certain groups, first use of basal insulin was associated with less gain in weight and decrease in HbA1c compared to other insulins.</p&gt

Precise Estimates of the Physical Parameters for the Exoplanet System HD-17156 Enabled by HST FGS Transit and Asteroseismic Observations

We present observations of three distinct transits of HD 17156b obtained with the Fine Guidance Sensors (FGS) on board the Hubble Space Telescope} (HST). We analyzed both the transit photometry and previously published radial velocities to find the planet-star radius ratio R_p/R_s = 0.07454 +/- 0.00035, inclination i=86.49 +0.24/-0.20 deg, and scaled semi-major axis a/R = 23.19 +0.32/-0.27. This last value translates directly to a mean stellar density determination of 0.522 +0.021/-0.018 g cm^-3. Analysis of asteroseismology observations by the companion paper of Gilliland et al. (2009) provides a consistent but significantly refined measurement of the stellar mean density. We compare stellar isochrones to this density estimate and find M_s = 1.275 +/- 0.018 M_sun and a stellar age of $3.37 +0.20/-0.47 Gyr. Using this estimate of M_s and incorporating the density constraint from asteroseismology, we model both the photometry and published radial velocities to estimate the planet radius R_p= 1.0870 +/- 0.0066 Jupiter radii and the stellar radius R_s = 1.5007 +/- 0.0076 R_sun. The planet radius is larger than that found in previous studies and consistent with theoretical models of a solar-composition gas giant of the same mass and equilibrium temperature. For the three transits, we determine the times of mid-transit to a precision of 6.2 s, 7.6 s, and 6.9 s, and the transit times for HD 17156 do not show any significant departures from a constant period. The joint analysis of transit photometry and asteroseismology presages similar studies that will be enabled by the NASA Kepler Mission.Comment: Accepted for publication to Ap

The Transit Light Curve Project. XIII. Sixteen Transits of the Super-Earth GJ 1214b

We present optical photometry of 16 transits of the super-Earth GJ 1214b, allowing us to refine the system parameters and search for additional planets via transit timing. Starspot-crossing events are detected in two light curves, and the star is found to be variable by a few percent. Hence, in our analysis, special attention is given to systematic errors that result from star spots. The planet-to-star radius ratio is 0.11610+/-0.00048, subject to a possible upward bias by a few percent due to the unknown spot coverage. Even assuming this bias to be negligible, the mean density of planet can be either 3.03+/-0.50 g cm^{-3} or 1.89+/-0.33 g cm^{-3}, depending on whether the stellar radius is estimated from evolutionary models or from an empirical mass-luminosity relation combined with the light curve parameters. One possible resolution is that the orbit is eccentric (e approximately equal to 0.14), which would favor the higher density, and hence a much thinner atmosphere for the planet. The transit times were found to be periodic within about 15s, ruling out the existence of any other super-Earths with periods within a factor-of-two of the known planet.Comment: Accepted in Ap

Accurately Reflecting Uncertainty When Using Patient-Level Simulation Models to Extrapolate Clinical Trial Data.

Introduction. Patient-level simulation models facilitate extrapolation of clinical trial data while allowing for heterogeneity, prior history, and nonlinearity. However, combining different types of uncertainty around within-trial and extrapolated results remains challenging. Methods. We tested 4 methods to combine parameter uncertainty (around the regression coefficients used to predict future events) with sampling uncertainty (uncertainty around mean risk factors within the finite sample whose outcomes are being predicted and the effect of treatment on these risk factors). We compared these 4 methods using a simulation study based on an economic evaluation extrapolating the AFORRD randomized controlled trial using the UK Prospective Diabetes Study Outcomes Model version 2. This established type 2 diabetes model predicts patient-level health outcomes and costs. Results. The 95% confidence intervals around life years gained gave 25% coverage when sampling uncertainty was excluded (i.e., 25% of 95% confidence intervals contained the "true" value). Allowing for sampling uncertainty as well as parameter uncertainty widened confidence intervals by 6.3-fold and gave 96.3% coverage. Methods adjusting for baseline risk factors that combine sampling and parameter uncertainty overcame the bias that can result from between-group baseline imbalance and gave confidence intervals around 50% wider than those just considering parameter uncertainty, with 99.8% coverage. Conclusions. Analyses extrapolating data for individual trial participants should include both sampling uncertainty and parameter uncertainty and should adjust for any imbalance in baseline covariates