Oral diabetes medication monotherapy and short-term mortality in individuals with type 2 diabetes and coronary artery disease

Objective To determine whether sulfonylurea use, compared with non-sulfonylurea oral diabetes medication use, was associated with 2-year mortality in individuals with well-controlled diabetes and coronary artery disease (CAD). Research design and methods We studied 5352 US veterans with type 2 diabetes, obstructive CAD on coronary angiography, hemoglobin A1c ≤7.5% at the time of catheterization, and taking zero or one oral diabetes medication (categorized as no medications, non-sulfonylurea medication, or sulfonylurea). We estimated the association between medication category and 2-year mortality using inverse probability of treatment-weighted (IPW) standardized mortality differences and IPW multivariable Cox proportional hazards regression. Results 49%, 35%, and 16% of the participants were on no diabetes medications, non-sulfonylurea medications, and sulfonylureas, respectively. In individuals on no medications, non-sulfonylurea medications, and sulfonylureas, the unadjusted mortality rates were 6.6%, 5.2%, and 11.9%, respectively, and the IPW-standardized mortality rates were 5.9%, 6.5%, and 9.7%, respectively. The standardized absolute 2-year mortality difference between non-sulfonylurea and sulfonylurea groups was 3.2% (95% CI 0.7 to 5.7) (p=0.01). In Cox proportional hazards models, the point estimate suggested that sulfonylurea use might be associated with greater hazard of mortality than non-sulfonylurea medication use, but this finding was not statistically significant (HR 1.38 (95% CI 1.00 to 1.93), p=0.05). We did not observe significant mortality differences between individuals on no diabetes medications and non-sulfonylurea users. Conclusions Sulfonylurea use was common (nearly one-third of those taking medications) and was associated with increased 2-year mortality in individuals with obstructive CAD. The significance of the association between sulfonylurea use and mortality was attenuated in fully adjusted survival models. Caution with sulfonylurea use may be warranted for patients with well-controlled diabetes and CAD, and metformin or newer diabetes medications with cardiovascular safety data could be considered as alternatives when individualizing therapy

Optical Spectral Signatures of Dusty Starburst Galaxies

We analyse the optical spectral properties of the complete sample of Very Luminous Infrared Galaxies presented by Wu et al. (1998a,b) and we find a high fraction (~50 %) of spectra showing both a strong H_delta line in absorption and relatively modest [OII] emission (e(a) spectra). The e(a) signature has been proposed as an efficient method to identify dusty starburst galaxies and we study the star formation activity and the nature of these galaxies, as well as the effects of dust on their observed properties. We examine their emission line characteristics, in particular their [OII]/H_alpha ratio, and we find this to be greatly affected by reddening. A search for AGN spectral signatures reveals that the e(a)'s are typically HII/LINER galaxies. We compare the star formation rates derived from the FIR luminosities with the estimates based on the H_alpha line and find that the values obtained from the optical emission lines are a factor of 10-70 (H_alpha) and 20-140 ([OII]) lower than the FIR estimates (50-300 M_sun yr^-1). We then study the morphological properties of the e(a) galaxies, looking for a near companion or signs of a merger/interaction. In order to explore the evolution of the e(a) population, we present an overview of the available observations of e(a)'s in different environments both at low and high redshift. Finally, we discuss the role of dust in determining the e(a) spectral properties and we propose a scenario of selective obscuration in which the extinction decreases with the stellar age.Comment: 26 pages, Latex, including 7 postscript figures, accepted for publication in the Astrophysical Journa

Constraints on a Universal IMF from UV to Near-IR Galaxy Luminosity Densities

We obtain constraints on the slope of a universal stellar initial mass function (IMF) over a range of cosmic star-formation histories (SFH) using z=0.1 luminosity densities in the range from 0.2 to 2.2 microns. The age-IMF degeneracy of integrated spectra of stellar populations can be broken for the Universe as a whole by using direct measurements of (relative) cosmic SFH from high-redshift observations. These have only marginal dependence on uncertainties in the IMF, whereas, fitting to local luminosity densities depends strongly on both cosmic SFH and the IMF. We fit to these measurements using population synthesis and find the best-fit IMF power-law slope to be Gamma=1.15+-0.2 (0.5 < M/M_solar < 120). This slope is in good agreement with the Salpeter IMF slope (Gamma=1.35). A strong upper limit of Gamma<1.7 is obtained which effectively rules out the Scalo IMF due to its too low fraction of high-mass stars. This upper limit is at the 99.7% confidence level if we assume a closed-box chemical evolution scenario and 95% if we assume constant solar metallicity. Fitting to the H-alpha line luminosity density, we obtain a best-fit IMF slope in good agreement with that derived from broadband measurements. Marginalizing over cosmic SFH and IMF slope, we obtain (95% conf. ranges, h=1): omega_stars = 1.1-2.0 E-3 for the stellar mass density; rho_sfr = 0.7-4.1 E-2 M_solar/yr/Mpc^3 for the star-formation rate density, and; rho_L = 1.2-1.7 E+35 W/Mpc^3 for the bolometric, attenuated, stellar, luminosity density (0.09-5 microns). Comparing this total stellar emission with an estimate of the total dust emission implies a relatively modest average attenuation in the UV (<=1 magnitude at 0.2 microns).Comment: 16 pages, accepted by Ap

Diffuse Ionized Gas in the Dwarf Irregular Galaxy DDO 53

The spectral characteristics throughout the dwarf irregular galaxy DDO 53 are studied. The results are very similar to those for other irregular galaxies: high excitation and low values of the [SII]/Halpha ratio. The most likely ionization source is photon leakage from the classical HII regions, without any other source, although the interstellar medium of the galaxy is quite perturbed. Moreover, the physical conditions throughout the galaxy do not change very much because both the photon leakage percentage and the ionization temperature are very similar. In addition, the determined metal content for two HII regions indicates that DDO 53 is a low-metallicity galaxy.Comment: 32 pages, 9 figures, 7 tables. AJ, in pres

Star Formation in Galaxies Along the Hubble Sequence

Observations of star formation rates (SFRs) in galaxies provide vital clues to the physical nature of the Hubble sequence, and are key probes of the evolutionary properties of galaxies. The focus of this review is on the broad patterns in the star formation properties of galaxies along the Hubble sequence, and their implications for understanding galaxy evolution and the physical processes that drive the evolution. Star formation in the disks and nuclear regions of galaxies are reviewed separately, then discussed within a common interpretive framework. The diagnostic methods used to measure SFRs are also reviewed, and a self-consistent set of SFR calibrations is presented as an aid to workers in the field.Comment: 41 pages, with 9 figures. To appear in Volume 36 of the Annual Review of Astronomy and Astrophysic

Validation of an electrogoniometry system as a measure of knee kinematics during activities of daily living

Purpose: The increasing use of electrogoniometry (ELG) in clinical research requires the validation of different instrumentation. The purpose of this investigation was to examine the concurrent validity of an ELG system during activities of daily living. Methods: Ten asymptomatic participants gave informed consent to participate. A Biometrics SG150 electrogoniometer was directly compared to a 12 camera three dimensional motion analysis system during walking, stair ascent, stair descent, sit to stand, and stand to sit activities for the measurement of the right knee angle. Analysis of validity was undertaken by linear regression. Standard error of estimate (SEE), standardised SEE (SSEE), and Pearson’s correlation coefficient r were computed for paired trials between systems for each functional activity. Results: The 95% confidence interval of SEE was reasonable between systems across walking (LCI = 2.43 °; UCI = 2.91 °), stair ascent (LCI = 2.09 °; UCI = 2.42 °), stair descent (LCI = 1.79 °; UCI = 2.10 °), sit to stand (LCI = 1.22 °; UCI = 1.41 °), and stand to sit (LCI = 1.17 °; UCI = 1.34 °). Pearson’s correlation coefficient r across walking (LCI = 0.983; UCI = 0.990), stair ascent (LCI = 0.995; UCI = 0.997), stair descent (LCI = 0.995; UCI = 0.997), sit to stand (LCI = 0.998; UCI = 0.999), and stand to sit (LCI = 0.996; UCI = 0.997) was indicative of a strong linear relationship between systems. Conclusion: ELG is a valid method of measuring the knee angle during activities representative of daily living. The range is within that suggested to be acceptable for the clinical evaluation of patients with musculoskeletal conditions

A comparison between Pa alpha and H alpha emission: The relation between HII region mean reddening, local gas density and metallicity

We measure reddenings to HII regions in NGC 2903, NGC 1512, M51, NGC 4449 and NGC 6946 from Hubble Space Telescope Pa alpha and H alpha images. Extinctions range from A_V ~ 5 - 0 depending upon the galaxy. For the galaxies with HST images in both lines, NGC 2903, NGC 1512 and M51, the Pa alpha and H alpha emission are almost identical in morphology which implies that little emission from bright HII regions is hidden from view by regions of comparatively high extinction. The scatter in the measured extinctions is only +- 0.5 mag. We compare the reddenings we measure in five galaxies using the Pa alpha to H alpha ratios to those measured previously from the Balmer decrement in the LMC and as a function of radius in M101 and M51. We find that luminosity weighted mean extinctions of these ensembles of HI regions are correlated with gas surface density and metallicity. The correlation is consistent with the mean extinction depending on dust density where the dust to gas mass ratio scales with the metallicity. This trend is expected if HII regions tend to be located near the mid-plane of a gas disk and emerge from their parent molecular clouds soon after birth. In environments with gas densities below a few hundred Msol/pc^2 star formation rates estimated from integrated line fluxes and mean extinctions are likely to be fairly accurate.Comment: accepted for publication in A

The limits of social class in explaining ethnic gaps in educational attainment

This paper reports an analysis of the educational attainment and progress between age 11 and age 14 of over 14,500 students from the nationally representative Longitudinal Study of Young People in England (LSYPE). The mean attainment gap in national tests at age 14 between White British and several ethnic minority groups were large, more than three times the size of the gender gap, but at the same time only about one-third of the size of the social class gap. Socio-economic variables could account for the attainment gaps for Black African, Pakistani and Bangladeshi students, but not for Black Caribbean students. Further controls for parental and student attitudes, expectations and behaviours indicated minority ethnic groups were on average more advantaged on these measures than White British students, but this was not reflected proportionately in their levels of attainment. Black Caribbean students were distinctive as the only group making less progress than White British students between age 11 and 14 and this could not be accounted for by any of the measured contextual variables. Possible explanations for the White British-Black Caribbean gap are considered

Increased muscle tension and reduced elasticity of affected muscles in recent-onset Graves' disease caused primarily by active muscle contraction

In 3 patients with Graves' disease of recent onset, length-tension diagrams were made during surgery for squint under eyedrop anesthesia. The affected muscles were found to be very stiff when the other eye looked straight ahead. It was expected that these stiff muscles would be able to shorten to some extent but would be unable to lengthen, due to fibrosis of the muscle. We found that the affected muscles did not shorten very much when the other eye looked into the field of action of the muscle. Unexpectedly however, they lengthenend considerably when the other eye looked out of the field of action of the muscle. This finding implies that the raised muscle tension and reduced elasticity of affected muscles in these cases of Graves' disease of recent onset were primarily caused by active muscle contraction, not by fibrosis

The Ha luminosity function and star formation rate up to z~1

We describe ISAAC/ESO-VLT observations of the Ha(6563) Balmer line of 33 field galaxies from the Canada-France Redshift Survey (CFRS) with redshifts selected between 0.5 and 1.1. We detect Ha in emission in 30 galaxies and compare the properties of this sample with the low-redshift sample of CFRS galaxies at z~0.2 (Tresse & Maddox 1998). We find that the Ha luminosity, L(Ha), is tightly correlated to M(B(AB)) in the same way for both the low- and high-redshift samples. L(Ha) is also correlated to L([OII]3727), and again the relation appears to be similar at low and high redshifts. The ratio L([OII])/L(Ha) decreases for brighter galaxies by as much as a factor 2 on average. Derived from the Ha luminosity function, the comoving Ha luminosity density increases by a factor 12 from =0.2 to =1.3. Our results confirm a strong rise of the star formation rate (SFR) at z<1.3, proportional to (1+z)^{4.1+/-0.3} (with H_0=50 km/s/Mpc, q_0=0.5). We find an average SFR(2800 Ang)/SFR(Ha) ratio of 3.2 using the Kennicutt (1998) SFR transformations. This corresponds to the dust correction that is required to make the near UV data consistent with the reddening-corrected Ha data within the self-contained, I-selected CFRS sample.Comment: 16 pages, 16 figures and 3 tables included, figures and text updated, same results as in the 1st version, accepted in MNRA