Absolute dimensions of eclipsing binaries. XXIV, The Be star system DW Carinae, a member of the open cluster Collinder 228

Context. The study of detached eclipsing binaries which are members of stellar clusters is is a powerful way of determining the properties of the cluster and of constraining the physical ingredients of theoretical stellar evolutionary models. Aims. DWCarinae is a close but detached early B-type eclipsing binary in the young open cluster Collinder 228. We have measured accurate physical properties of the components of DWCar (masses and radii to 1%, effective temperatures to 0.02 dex) and used these to derive the age, metallicity and distance of Collinder 228. Methods. The rotational velocities of both components of DWCar are high, so we have investigated the performance of double-Gaussian fitting, one- and two-dimensional cross-correlation and spectral disentangling for deriving spectroscopic radial velocites in the presence of strong line blending. Gaussian and cross-correlation analyses require substantial corrections for the effects of line blending, which are only partially successful for cross-correlation. Spectral disentangling is to be preferred because it does not assume anything about the shapes of spectral lines, and is not significantly affected by blending. However, it suffers from a proliferation of local minima in the least-squares fit. We show that the most reliable radial velocities are obtained using spectral disentangling constrained by the results of Gaussian fitting. Complete Strömgren uvby light curves have been obtained and accurate radii have been measured from them by modelling the light curves using the Wilson-Devinney program. This procedure also suffers from the presence of many local minima in parameter space, so we have constrained the solution using an accurate spectroscopic light ratio. The effective temperatures and reddening of the system have been found from Strömgren photometric calibrations. Results. The mass and radius of DWCarA are MA = 11.34 ± 0.12 M and RA = 4.558 ± 0.045 R. The values for DWCar B are MB =10.63 ± 0.14 M and RB = 4.297 ± 0.055 R. Strömgren photometric calibrations give effective temperatures of TeffA = 27 900 ±1000 K and TeffB = 26 500 ± 1000 K, and a reddening of Eb−y = 0.18 ± 0.02, where the quoted uncertainties include a contribution from the intrinsic uncertainty of the calibrations. The membership of DWCar in Cr 228 allows us to measure the distance, age and chemical composition of the cluster. We have used empirical bolometric corrections to calculate a distance modulus of 12.24 ±0.12 mag for DWCar, which is in agreement with, and more accurate than, literature values. A comparison between the properties of DWCar and the predictions of recent theoretical evolutionary models is undertaken in the mass-radius and mass-Teff diagrams. The model predictions match the measured properties of DWCar for an age of about 6 Myr and a fractional metal abundance of Z ≈ 0.01

Eclipsing Binaries in Open Clusters

Detached eclipsing binaries are very useful objects for calibrating theoretical stellar models and checking their predictions. Detached eclipsing binaries in open clusters are particularly important because of the additional constraints on their age and chemical composition from their membership of the cluster. I compile a list containing absolute parameters of well-studied eclipsing binaries in open clusters, and present new observational data on the B-type systems V1481 Cyg and V2263 Cyg which are members of the young open cluster NGC 7128.Comment: 4 pages, 2 colour figures. Poster presentation for IAUS 240 (Binary Stars as Critical Tools and Tests in Contemporary Astrophysics), Prague, August 2006. The poster itself can be dowloaded in ppt and pdf versions from http://www.astro.keele.ac.uk/~jkt/pubs.htm

Glucose-Insulin Dynamical Model for Type 2 Diabetic Patients

In this paper, a literature review is made for the current models of glucose-insulin dynamics of type 2 diabetes patients. Afterwards, a model is proposed by combining and modifying some of the available models in literature to take into account the effect of multiple glucose meals, multiple metformin doses, insulin injections, physical exercise, and stress on the glucose-insulin dynamics of T2D patients. The model is proposed as a candidate to be validated with real patients data in the future

Treatment of polydrug-using opiate dependents during withdrawal: towards a standardisation of treatment

BACKGROUND: The growing tendency among opioid addicts to misuse multiple other drugs should lead clinicians and researchers to search for new pharmacological strategies in order to prevent life-threatening complications and minimize withdrawal symptoms during polydrug detoxification. METHODS: A non-randomised, open-label in-patient detoxification study was used to compare the short-time efficacy of a standardised regimen comprising 6 days Buprenorphine and 10 days Valproate (BPN/VPA) (n = 12) to a control group (n = 50) who took a 10-day traditional Clonidine/Carbamazepine (CLN/CBZ) regimen. Sixty-two dependent subjects admitted to a detoxification unit were included, all dependent on at least opioids and benzodiazepines. Other dependencies were not excluded. RESULTS: In the BPN/VPA group, 8 out of 12 patients (67%) completed treatment compared with 25 of 50 patients (50%) in the CLN/CBZ group; this difference between the groups was non-significant (p = 0.15). Withdrawal symptoms were reduced in both groups, but only the BPN/VPA group achieved a reduction in withdrawal symptoms from day one. The difference between the two groups was significantly in favour of the BPN/VPA group for days 2 (p < 0.001), 3 (p < 0.05), 4 (p < 0.001), 5 (p < 0.01), 7 (p < 0.01) and 8 (p < 0.05). The BPN/VPA combination did not affect blood pressure, pulse or liver function, and the total burden of side-effects was experienced as modest. There appeared to be no pharmacological interactions of clinical concern, based on measurement of Buprenorphine and Valproate serum levels. Both the patients and the staff were satisfied with the standardised treatment combination. CONCLUSION: Overall, the combination of Buprenorphine and Valproate seems to be a safe and promising method for treating multiple drug withdrawal symptoms. The results of this study suggest that the BPN/VPA combination is potentially a better detoxification treatment for polydrug withdrawal than the traditional treatment with Clonidine and Carbamazepine. However, a randomised, double-blind study with a larger sample size to confirm our results is recommended. TRIAL REGISTRATION: Clinical Trials.gov: NCT0036787

Appetite, energy intake, and PYY3-36 responses to energy-matched continuous exercise and submaximal high-intensity exercise.

High-intensity intermittent exercise induces physiological adaptations similar to energy-matched continuous exercise, but the comparative appetite and energy balance responses are unknown. Twelve healthy males (mean ± SD: age, 22 ± 3 years; body mass index, 23.7 ± 3.0 kg·m(-2); maximum oxygen uptake, 52.4 ± 7.1 mL·kg(-1)·min(-1)) completed three 8 h trials (control, steady-state exercise (SSE), high-intensity intermittent exercise (HIIE)) separated by 1 week. Trials commenced upon completion of a standardized breakfast. Exercise was performed from hour 2 to hour 3. In SSE, 60 min of cycling at 59.5% ± 1.6% of maximum oxygen uptake was performed. In HIIE, ten 4-min cycling intervals were completed at 85.8% ± 4.0% of maximum oxygen uptake, with a 2-min rest between each interval. A standardized lunch and an ad libitum afternoon meal were provided at hours 3.75 and 7, respectively. Appetite ratings and peptide YY3-36 concentrations were measured throughout each trial. Appetite was acutely suppressed during exercise, but more so during HIIE (p < 0.05). Peptide YY3-36 concentrations increased significantly upon cessation of exercise in SSE (p = 0.002), but were highest in the hours after exercise in HIIE (p = 0.05). Exercise energy expenditure was not different between HIIE and SSE (p = 0.649), but perceived exertion was higher in HIIE (p < 0.0005). Ad libitum energy intake did not differ between trials (p = 0.833). Therefore, relative energy intake (energy intake minus the net energy expenditure of exercise) was lower in the SSE and HIIE trials than in the control trial (control, 4759 ± 1268 kJ; SSE, 2362 ± 1224 kJ; HIIE, 2523 ± 1402 kJ; p < 0.0005). An acute bout of energy-matched continuous exercise and HIIE were equally effective at inducing an energy deficit without stimulating compensatory increases in appetite

Impacts of Extension Education on Improving Residential Stormwater Quality: Monitoring Results

The project reported in this article evaluated whether stormwater quality could be improved by educating homeowners and implementing best management practices in a suburban neighborhood. Nitrogen, phosphorus, and bacteria levels from two watersheds were compared using the paired watershed approach. Resident surveys, property site assessments, soil tests, and water quality and quantity monitoring were conducted. A x2-analysis of survey data indicated no significant changes in measured behavior. Significant (p=0.01) reductions in NO3-N and fecal coliform bacteria concentrations occurred; however, total nitrogen concentrations did not change significantly