L.D.H. and L.D.H. isoenzymes of the intra-uterine secretions of the cow during the estrous cycle

Uterine secretions were collected from 20 mature cows during estrus (day 0), metestrus (day 5), diestrus (day 10) and proestrus (day-1). Lactate dehydrogenase (LDH) and LDH isoenzymes activity were evaluated. No significant cyclic variations of LDH activity was found in the uterine secretions while the mean of the enzyme activity was higher during the estrogenic period of the cycle. The relative activity of LDH-1, LDH-2 and LDH-3 isoenzymes were higher during proestrus and estrus whereas LDH-5 activity was more important during metestrus. The LDH-3 seems to have the higher relative activity in uterine secretions of the cow.     

J. B. S. Haldane and the origin of life

In 1929 the British biologist John Burdon Sanderson Haldane published a hypothesis on the origin of life on earth, which was one of the most emblematic of the interwar period. It was a scenario describing the progressive evolution of matter on the primitive earth and the emergence of life. Firstly, this paper presents the main ideas put forward by Haldane in this famous text. The second part makes comparisons between Haldane and Alexander Ivanovitch Oparin’s ideas regarding the origins of life (1924). These two theories, apparently very similar, presented distinct conclusions. The third part focusses on Haldane’s reflections on the emergence of life during the 1950s and 1960s, and shows how they were linked to the recent developments of prebiotic chemistry and molecular biology.     

N.A. Dobrovolskaya-Zavadskaya and the discovery of the T gene

Nadezhda Alexandrovna Dobrovolskaya-Zavadskaya was born in Kiev on September 13, 1878. She studied medicine in Saint Petersburg where in the early 1900s, Dobrovolskaya became one of the best known women surgeons. After the First World War started in 1914, she joined the Russian army and worked in military hospitals until 1917, when the revolution dramatically changed the fate of Russia and all Russians. At the end of civil war she was working in the hospital in the army of General Wrangel. After the defeat of Wrangel in 1920, Dobrovolskaya left Russia and went into exile. Like many other Russian emigr[symbol: see text]s, she came to Paris after fleeing Crimea via Turkey and Egypt. (Unfortunately, this period of the life of Nadezhda Dobrovolskaya is completely unknown to me.)