A Search for Pulsating, Mass-Accreting Components in Algol-Type Eclipsing Binaries

We present a status report on the search for pulsations in primary componants of Algols systems (oEA stars). Analysis of 21 systems with A0-F2 spectral type primaries revealed pulsations in two systems suggesting that of the order of ten persent of Algols primaries in this range are actually pulsators

A unified solution for the orbit and light-time effect in the V505 Sgr system

The multiple system V505 Sagittarii is composed of at least three stars: a compact eclipsing pair and a distant component, which orbit is measured directly using speckle interferometry. In order to explain the observed orbit of the third body in V505 Sagittarii and also other observable quantities, namely the minima timings of the eclipsing binary and two different radial velocities in the spectrum, we thoroughly test a fourth-body hypothesis - a perturbation by a dim, yet-unobserved object. We use an N-body numerical integrator to simulate future and past orbital evolution of 3 or 4 components in this system. We construct a suitable chi^2 metric from all available speckle-interferometry, minima-timings and radial-velocity data and we scan a part of a parameter space to get at least some of allowed solutions. In principle, we are able to explain all observable quantities by a presence of a fourth body, but the resulting likelihood of this hypothesis is very low. We also discuss other theoretical explanations of the minima timings variations. Further observations of the minima timings during the next decade or high-resolution spectroscopic data can significantly constrain the model

Period changes in six semi-detached Algol-type binaries

Six semi-detached Algol-type binaries lacking a period analysis were chosen to test for a presence of a third body. The O-C diagrams of these binaries were analyzed with the least-squares method by using all available times of minima. Also fourteen new minima, obtained from our observations, were included in the present research. The light-time effect was adopted as a main factor for the detailed description of the long-term period changes. Third bodies were found with orbital periods from 46 up to 84 years, and eccentricities from 0.0 to 0.78 for the selected binaries. The mass functions and the minimal masses of such bodies were also calculated.Comment: 14 pages, 8 figure

Photometric Observation And Period Study of GO Cygni

Photometric observations of GO Cyg were performed during the July-October 2002, in B and V bands of Johnson system. Based on Wilson's model, the light curve analysis were carried out to find the photometric elements of the system. The O-C diagram which is based on new observed times of minima suggests a negative rate of period variation (dP/dt<0) for the system.Comment: 12 pages, 6 figures, 4 tables, submitted to Ap&S

Period changes in six contact binaries: WZ And, V803 Aql, DF Hya, PY Lyr, FZ Ori, and AH Tau

Six contact binaries lacking a period analysis have been chosen to search for the presence of a third body. The O-C diagrams of these binaries were analyzed with the least-squares method by using all available times of minima. Ten new minima times, obtained from our observations, were included in the present research. The Light-Time Effect was adopted for the first time as the main cause for the detailed description of the long-term period changes. Third bodies were found with orbital periods from 49 up to 100 years, and eccentricities from 0.0 to 0.56 for the selected binaries. In one case (WZ And), a fourth-body LITE variation was also applied. The mass functions and the minimal masses of such bodies were also calculated and a possible angular separation and magnitude differences were discussed for a prospective interferometric discovery of these bodies.Comment: 7 pages, 8 figures, 2009 New Astronomy 14, 12

Assessing the knowledge of bronchial asthma among primary health care physicians in Crete: A pre- and post-test following an educational course

AIM: To assess the level of knowledge for bronchial asthma of the primary healthcare physicians serving a rural population on the island of Crete, both before and immediately after a one-day educational course. METHODS: Twenty-one primary health care physicians, randomly selected from a list of 14 Health Care Centres on the island of Crete were invited to participate in the study and attended an educational course. Nine of the 21 physicians were fully qualified general practitioners, while the remainder were non-specialized (NSs) physicians who had recently graduated from the University of Crete, Medical School. A questionnaire of 20 items based on current bronchial asthma clinical guidelines was used. Three scores, the mean total, knowledge subscore and attitudes subscore, were calculated for each group of physicians, both before and after the course. RESULTS: At baseline mean total score and knowledge and attitudes subscores were higher for non-specialized physicians than for the general practitioners, but the differences were not statistically significant (p > 0.05). The knowledge subscore was improved in both groups, however the difference was statistically significant only for the non-specialized physicians (t = 2.628, d.f. = 11, p < 0.05). The mean total score after the course was significantly higher for the non-specialized physicians in comparison to that of the general practitioners (t=-2.688, d.f. = 19, p < 0.05). CONCLUSIONS: This study adds to the information about the success of continuing medical education, and also demonstrates that the recent graduates in the studied population, could be educated with more positive results than the fully qualified practitioner

Soil-structure interaction effects in analysis of seismic fragility of bridges using an intensity-based ground motion selection procedure

The paper focuses on the effects of Soil-Structure Interaction (SSI) in seismic fragility analysis of reinforced concrete (RC) bridges, considering the vulnerability of multiple critical components of the bridge and different modelling approaches for soil-foundation and bridge-embankment interactions. A two-step procedure, based on the introduction of springs and dashpots at the pier foundations and the abutment to account for inertial and kinematic SSI effects, is incorporated into a component-based methodology for the derivation of bridge-specific fragility curves. The proposed methodology is applied for quantifying the fragility of a typical highway overpass at both the component and system level, while the effect of alternative procedures (of varying complexity) for modelling foundation and abutment boundary conditions is critically assessed. The rigorous SSI modelling method is compared with simpler methods and the results show that consideration of SSI may only slightly affect the probability of system failure, depending on the modelling assumptions made. However, soil-structure interaction may have a notable effect on component fragility, especially for the more critical damage states. This is an observation that is commonly overlooked when assessing the structural performance at the system level and can be particularly important when component fragility is an issue, e.g. when designing a retrofit scheme

The most plausible explanation of the cyclical period changes in close binaries: the case of the RS CVn-type binary WW Dra

We searched the orbital period changes in 182 EA-type (including the 101 Algol systems used by \cite{hal89}), 43 EB-type and 53 EW-type binaries with known both the mass ratio and the spectral type of their secondary components. We reproduced and improved the same diagram as Hall's (1989) according to the new collected data. Our plots do not support the conclusion derived by \cite{hal89} that all cases of cyclical period changes are restricted to binaries having the secondary component with spectral types later than F5. The presence of period changes also among stars with secondary component of early type indicates that the magnetic activity is one cause, but not the only one, for the period variation. It is discovered that cyclic period changes, likely due to the presence of a third body are more frequent in EW-type binaries among close binaries. Therefore, the most plausible explanation of the cyclical period changes is the LTTE via the presence of a third body. By using the century-long historical record of the times of light minimum, we analyzed the cyclical period change in the Algol binary WW Dra. It is found that the orbital period of the binary shows a $\sim112.2 \textbf{\textrm{yr}}$ cyclic variation with an amplitude of $\sim0.1977\textbf{\textrm{days}}$. The cyclic oscillation can be attributed to the LTTE via a third body with a mass no less than $6.43 M_{\odot}$. However, no spectral lines of the third body were discovered indicating that it may be a candidate black hole. The third body is orbiting the binary at a distance shorter than 14.4 AU and it may play an important role in the evolution of this system.Comment: 9 pages, 5 figures, published by MNRA

Automated office blood pressure measurements in primary care are misleading in more than one third of treated hypertensives: The VALENTINE-Greece Home Blood Pressure Monitoring study

Abstract Background This study assessed the diagnostic reliability of automated office blood pressure (OBP) measurements in treated hypertensive patients in primary care by evaluating the prevalence of white coat hypertension (WCH) and masked uncontrolled hypertension (MUCH) phenomena. Methods Primary care physicians, nationwide in Greece, assessed consecutive hypertensive patients on stable treatment using OBP (1 visit, triplicate measurements) and home blood pressure (HBP) measurements (7 days, duplicate morning and evening measurements). All measurements were performed using validated automated devices with bluetooth capacity (Omron M7 Intelli-IT). Uncontrolled OBP was defined as ≥140/90 mmHg, and uncontrolled HBP was defined as ≥135/85 mmHg. Results A total of 790 patients recruited by 135 doctors were analyzed (age: 64.5 ± 14.4 years, diabetics: 21.4%, smokers: 20.6%, and average number of antihypertensive drugs: 1.6 ± 0.8). OBP (137.5 ± 9.4/84.3 ± 7.7 mmHg, systolic/diastolic) was higher than HBP (130.6 ± 11.2/79.9 ± 8 mmHg; difference 6.9 ± 11.6/4.4 ± 7.6 mmHg, p Conclusions In primary care, automated OBP measurements are misleading in approximately 40% of treated hypertensive patients. HBP monitoring is mandatory to avoid overtreatment of subjects with WCH phenomenon and prevent undertreatment and subsequent excess cardiovascular disease in MUCH

The peculiar eclipsing star BD+13°3496 (V508 ophiuchi): New BV observations and light curve analysis

New BV photoelectric observations of the W UMa-type system V508 Ophiuchi, made in 1986 at the Kryonerion Astronomical Center of the National Observatory of Athens, Greece, are given. The corresponding mean light curves, as well as those obtained in 1981 at the same station using the same instruments, are analysed using frequency-domain techniques. The geometrical and photometric elements of the system have been found. These are combined with the now available spectroscopic data of the system to get its absolute elements. A general discussion for the light variations between the old and the new observations is made. From the light curve analysis it was found that V508 Oph is an A-type W UMa binary with both of its components to fill their corresponding Roche lobes. © 1989 Kluwer Academic Publishers