Context. Light and spectrum variations of the magnetic chemically peculiar (mCP) stars are explained by the oblique rigid rotator model with a rotation period usually assumed to be stable on a long time scale. A few exceptions, such as CU Vir or 56 Ari, have been reported as displaying an increase in their rotation period. A possible increase in the period of light and spectrum variations has also been suggested from observations of the helium-strong mCP star HD 37776 (V901 Ori). Aims. In this paper we attempt to confirm the possible period change of HD 37776 and discuss a possible origin of this change as a consequence of i) duplicity; ii) precession; iii) evolutionary changes; and iv) continuous/discrete/transient angular momentum loss. Results. We confirm the previously suspected gradual increase in the 1. d 5387 period of HD 37776 and find that it has lengthened by a remarkable 17.7 ± 0.7 s over the past 31 years. We also note that a decrease in the rate of the period change is not excluded by the data. The shapes of light curves in all colours were found to be invariable. Conclusions. After ruling out light-time effects in a binary star, precession of the rotational axis, and evolutionary changes as possible causes for the period change, we interpret this ongoing period increase as a braking of the star's rotation, at least in its surface layers, due to the momentum loss through events or processes in the extended stellar magnetosphere.

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Light variations of a representative sample of 26 more or less periodically variable carbon stars were analyzed on the basis of 2220 individual observations made by the Hipparcos satellite and 33 544 visual observations listed in AFOEV and VSOLJ databases within the interval JD = 2 448 000 (1988) ±6 cycles. We found the osculating linear ephemerides of all stars and their mean light curves, as well. We found that the light curves of the carbon Miras in our set can be satisfactorily expressed as a linear combination of only two basic light curves. The analysis was done by an own method combining robust regression and principal component analysis.

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Phonological neighborhood density is known to influence lexical access, speech production and perception processes. Lexical competition is considered the central concept from which the neighborhood effect emanates: highly competitive neighborhoods are characterized by large degrees of phonemic co-activation, which can delay speech recognition and facilitate speech production. The study investigates phonetic learning in English as a foreign language in relation to phonological neighborhood density and onset density to see if dense or sparse neighborhoods are more conducive to the incorporation of novel phonetic detail. Also, the effect of voice-contrasted minimal pairs is explored. The results indicate that sparser neighborhoods with weaker lexical competition provide the most optimal phonological environment for phonetic learning. Moreover, novel phonetic details are incorporated faster in neighborhoods without minimal pairs. The results indicate that lexical competition plays a role in the dissemination of phonetic updates in the lexicon of foreign language learners.

We present the results of a deep statistical analysis of the continual measurement of the mean illumination at night in the area of VSB-Technical University in Ostrava. The illumination during 509 nights between the years 2006 to 2009 was studied in detail in relation to the characteristics of a particular night. Using a sophisticated linear model applied to the logarithm of the mean night illumination, we determined the dependence of the night illumination on cloudiness, moon phases, and seasons as well as on snow cover. The model is able to predict the night illumination with quasi-random uncertainty of 0.21 dex. This uncertainty can be caused by hardly quantifiable events like rainfall, snowfall, fog or clouds with different albedo. It can also be a consequence of various human activities that may influence the illumination of sky at night

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