Results of UBV Photoelectric Observations of the Early-Type Eclipsing Binary System XZ Cep

Results of the three-colour photoelectric observation of the close binary system XZ Cep, obtained at the Abastumani Astrophysical observatory, are presented.Comment: 23 pages, 3 figures, 1 tebl

Population genomics of Bronze Age Eurasia

The Bronze Age of Eurasia (around 3000–1000BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highlydynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic structure in both Europe and Asia. Our findings are consistent with the hypothesized spread of Indo-European languages during the Early Bronze Age. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency in the Bronze Age, but not lactose tolerance, indicating a more recent onset of positive selection on lactose tolerance than previously thought

Screening of yeast species for the stereo-selective reduction of bicyclo[2.2.2]octane-2,6-dione

Yeast strains from more than 31 different genera were screened for the enantioselective reduction of bicyclo[2.2.2]-octane-2,6-dione (1). Reducing activity was found in 80% of the screened yeasts. Bicyclo[2.2.2]octane-2,6-dione was enantioselectively reduced (> 98% ee) to (1R, 4S, 6S)-6-hydroxybicyclo[2.2.2]octane-2-one (-)-2 by 69% of the strains. Enantioselective reduction of the diketone to (1S, 4R, 6S)-6-hydroxybicyclo[2.2.2]octane-2-one ((+)-3, >98% ee) as a major product is reported for the first time. Candida tropicalis UOFS Y-0534 and Candida wickerhamii UOFS Y-0652 displayed this unusual diastereoselectivity