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A catalogue of (411) Algol-type (semi-detached) binary stars is presented in the form of five separate tables of information. The catalogue has developed from an earlier version by including more recent information and an improved layout. A sixth table lists (1872) candidate Algols, about which fewer details are known at present. Some issues relating to the classification and interpretation of Algol-like binaries are also discussed.

The radial velocity and UBVlight curves of V899 Her as found in the literature were studied for the first time to obtain the orbital parameters and geometry of the system. The solutions obtained by using the Wilson-Devinney code reveal an over-contact system with a fill-out factor of $23.7\%$. This solution is only possible with a large amount of third light ($L_{3}\approx0.68$) which confirms the spectroscopic result obtained by Lu et al. ([CITE]) who reported that the system of which V899 Her is a fainter component is triple, or even quadruple. The distance of the system found by using absolute parameters is comparable with the Hipparcos result.

The first ground-based BVR photometric observations of the recently discovered eclipsing binary V744 Cas are presented. From these measurements, timings for two primary and one secondary minima have been calculated. The light curves of the system were analyzed by using the Wilson-Devinney program. The analysis shows that the system is detached with two similar components of spectral type A2V, and the orbit is eccentric (e = 0.0662 ± 0.0005). The longitude of the periastron (ω) was found significantly different for two different light curves (ours and that of Hipparcos), which is strongly suggestive of an apsidal motion with a period of about 425 ± 68 yr. This makes V744 Cas an important candidate for studies of apsidal motions. The first estimate of the absolute dimensions place the system close to the terminal age of the main sequence (TAMS) in the HR diagram. The distance from the spectroscopic parallax (d = 740 ± 10 pc) was found to be slightly larger than the Hipparcos distance of d = 610 ± 400 pc. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Toxoplasma gondii is an obligate intracellular protozoan parasite. The objective of the present study was to examine the behaviour of Toxoplasma gondii RH Ankara strain tachyzoites in a cell culture environment. The study represents the first step in determining whether T. gondii RH Ankara strain tachyzoites, grown in cell culture, are of sufficient quality to allow cessation of in vivo tachyzoite production for diagnostic assays. In the present study, T. gondii RH Ankara strain tachyzoites were continuously produced in myeloma X63.Ag8.653, HeLa, Hep-2, and Vero cell cultures for 2 months. The average size of the tachyzoites was 3×5·7 μm prior to the first inoculation but after continuous production, a marked decrease was noted in average tachyzoite size. The smallest tachyzoite size, was 1×2·1 μm after 2 months, in myeloma cell cultures even though the yield of tachyzoites increased. With other cell cultures, tachyzoite yields were not as high as myeloma cell culture although decrease in size was less. The smallest decrease in tachyzoite size, averaging 2×3·8 μm after 2 months, was observed in tachyzoites produced in HeLa cell cultures. A virulence assay in small groups of BALB/c mice, using tachyzoites derived from cell cultures, was also conducted. The preliminary results of the virulence assay suggest that as the size of the tachyzoites decreased, the virulence in mice decreased. Future research will focus on the effect of the size of cell culture-derived T. gondii RH Ankara strain tachyzoites on the virulence, protein expression, and the reliability of diagnostic assays. Ultimately, the behaviour of tachyzoites from various T. gondii strains will be observed in cell culture to determine if size is altered.

New BVR light curves and photometric analysis of the eclipsing binary star CN And are presented. The shape of the light curves are typical of β Lyr type, and there are large asymmetries between maxima. The BVR light curves and the radial velocity curves (from Rucinski et al. 2000) were solved with the Wilson-Devinney method, simultaneously. The results suggest that CN And is a almost contact binary system, in which the component stars are filling ∼99% of their Roche lobes. We discuss the model with a large dark starspot on the more massive star and a bright substellar spot on the companion to account for the light curve asymmetries. The absolute parameters of the system were also derived. The system resembles the near contact binary V1010 Oph according to its Roche configuration and light curve asymmetries. We, also, discuss the evolution of the system: it seems to be in a transition phase to the contact era. All previous times of minimum light were collected and combined with the new ones presented in this work. The variation of the orbital period of the system was then analyzed. The results reveal that the orbital period has a secular decrease of about 1.98 ± 0.04 sec per century, which corresponds to a conservative mass transfer from the more to the less massive component at a rate of (1.52 ± 0.09) × 10–7m⊙/yr or a mass loss from the primary component due to magnetic stellar winds at a rate of (7.83 ± 0.09) × 10–8m⊙/yr. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

New photoelectric observations of the eccentric orbit binary CW Cephei have been carried out in B, V and R colours during the 2000 observing season at TÜBITAK (The Scientific and Technical Research Council of Turkey) National Observatory. The light curves of the system were analyzed with a nonsynchronous rotation approach using the method of Wilson-Devinney in B, V and R bands, simultaneously. Especially, we used the R band to check for a third light in the solution as distinct from previous studies. But, the third light contribution in the light curves comes out to be almost negligible. In this study, the values of the longitude of periastron (ω) of the system's orbit found in the solutions of the light curves and radial velocity curves were collected and the variation of ω with time was investigated. A new value of the apsidal motion velocity has been obtained as $ \dot \omega $ =0.0582 ± 0.0011 (deg/cycle), corresponding to an apsidal period U = 46 ± 1 yr. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)