The 70th anniversary of E.N. Pavlovsky’s concept of natural nidality of human diseases

The concept of the natural nidality of human diseases has significantly changed during the last 70 years, but its essence is preserved. Many “new” infections with natural foci were discovered and their geographical distribution was investigated in detail, and the classification of natural foci was developed. It has been established that epidemic features of transmissible infections depend mainly on types of parasitism of insect, tick and mite vectors.     

R. J. Gordon’s Discovery of the Spotted Hyena’s Extraordinary Genitalia in 1777

In the history of zoology the English anatomist Morrison Watson (1845–1885) is considered to be the discoverer of the masculinized sexual organs of the spotted hyena. Beginning in 1877, Watson had published a series of anatomical studies on the spotted hyena (Watson, 1877, 1878, 1881, Watson and Young, 1879), in which he, in which he for the first time made public the anatomical peculiarities of the female spotted hyena’s genitalia. This scientific achievement is well documented. But now we can also state that a hundred years before Watson the Dutch amateur zoologist Robert Jacob Gordon (1743–1795), while serving in the Scots Brigades at the Cape of Good Hope, had already made the same discovery and merely unfortunate personal circumstances prevented publication. During his stay at the Cape, Gordon had studied spotted hyenas intensively and recorded his observations in accurate drawings and comments. These drawings have been preserved as part of a large collection of animal drawings entitled Gordon Atlas. With his discovery, Gordon actually was the first to provide empirical evidence of a “curious and inexplicable case of dimorphism” (Darwin on a beetle) in mammalians, long before étienne Geoffrey Saint-Hilaire (Cours de l’histoire naturelle des mammifères, 1829) started examining masculinized sexual organs in the mole or Darwin recognized the importance of sexual dimorphism (Descent of Man, 1871). In this paper we reproduce for the first time all hyena drawings from the Gordon Atlas, including Gordon’s handwritten notes in the margins in the original Dutch and in translation. Additionally, we briefly delineate the knowledge about the South African spotted hyena in Gordon’s time and indicate that we doubt Watson’s explanation for the age-old confusion about the hyena.     

On the Mechanism of Brewer’s Yeast Flocculation

Brewer’s yeast appears to flocculate or disperse reversibly in response to the environmental conditions. The yeast and its solubilized cell surface substance show flocculation-dispersion changes according to pH, sugar concentration and flocculation inducing substances. Top fermentative yeasts do not show such a response to the surrounding conditions. Cell surfaces of bottom fermentative yeasts increase in hydrophobicity during a shift from fermentation starting conditions (dispersion of yeast) (high sugar concentration, pH 5.5) to ending conditions ( flocculation) (no sugar, pH 4.2), but this hydrophobicity increase was not seen in the case of top fermentative yeast cells. The contributions of hydrophobic interaction and ionic bonds to flocculence of the yeast were discussed.     

To the 100th anniversary of N.I. Shapiro (1906–1987)

Chronicle

To the 100th anniversary of N.I. Shapiro (1906–1987)     

N.K. Kol’tsov and experimental embryology (dedicated to the 140th anniversary of his birth)

It is common knowledge that the majority of N.K. Kol??tsov??s studies investigated the structure of a cell through the methods of physical chemistry and cytogenetics. At the same time, Kol??tsov was also interested in the development of experimental biology, specifically experimental embryology.     

“Do not lose the winning games” to the 100th anniversary of M.E. Lobashev

Mikhail E. Lobashev (1907–1971), Head of the Department of Genetics and Breeding with the Leningrad (now, St. Petersburg) State University from 1957 to 1971, had traveled a long way from a homeless to an Honored Scientist of the Russian Federation. Lobashev was among the discoverers of chemical mutagenesis in Drosophila; he pioneered in connecting the mutation process and the repair of genetic material and developed the concept of signal inheritance. Through the entire Great Patriotic War, he served with the field forces, and defended his doctoral dissertation on the physiological hypothesis of mutation process in 1946 on the return to the University. In 1948, Mikhail Efimovich was discharged from the University, where he was the Dean of the Biological Faculty, as a Morganist. On his return to the University in 1957, Lobashev devoted all his energies to the restoration of genetic education in this country, wrote the first domestic genetic textbook in the post-Lysenko period, organized the research at the Department of Genetics and Breeding, and created the scientific school, whose representatives are still successfully working in the field of genetics.     

The 125th anniversary of the first postulation of the soil origin of endophytic bacteria – a tribute to M.L.V. Galippe

Aims

In spite of the important role played by herbivory in plant community structure and the fact that it constitutes one of the most important ecological disturbance processes in the dynamics of both natural and anthropic systems, few studies have concentrated on the consequences of browsing on vegetation spatial patterns. The main objective of this study was to examine the role of domestic livestock pressure in the spatial distribution pattern and interspecific competition of two sand dune shrubs: Retama monosperma and the endangered species Thymus carnosus.

Methods

We compared three areas featuring different intensities of livestock pressure. Two 25 × 25 m plots were established in each study area, and the crown heights, diameters and x, y coordinates of every individual in each plot were recorded.

Results

Livestock activity produced a considerable effect, not only on plant cover and size (larger and higher crowns of both species in non herbivory plots) but also on spatial pattern. Whereas light herbivory lead to a random spatial pattern for both species, high herbivory resulted in a repulsion one.

Conclusions

Under high and no livestock pressure, T. carnosus is displaced by R. monosperma, creating a repulsion point pattern distribution between the two species. However, when livestock disturbance was low, our data reveal relatively higher T. carnosus cover values than in the other livestock pressure scenarios, along with a random distribution pattern.