Small cycles, generalized prisms and Hamiltonian cycles in the Bubble-sort graph

The Bubble-sort graph $BS_n,\,n\geqslant 2$, is a Cayley graph over the symmetric group $Sym_n$ generated by transpositions from the set $\{(1 2), (2 3),\ldots, (n-1 n)\}$. It is a bipartite graph containing all even cycles of length $\ell$, where $4\leqslant \ell\leqslant n!$. We give an explicit combinatorial characterization of all its $4$- and $6$-cycles. Based on this characterization, we define generalized prisms in $BS_n,\,n\geqslant 5$, and present a new approach to construct a Hamiltonian cycle based on these generalized prisms.Comment: 13 pages, 7 figure

Chronic social stress and psychological distress in Russia

From background summary: In the last two decades, after the collapse of the Soviet Union, chronic social stress and poor mental health have been recognized in Russia as important research areas. The current study is part of a larger chronic social stress research project initiated through Health Promotion Research Centre at the University of Bergen in Norway. In the overall project, data have been collected so far in Norway, Romania, Thailand and Russia. As in the other countries, the main aim of this Russian study was to explore the relationship between chronic social stress, social support, coping resources and distress in a community-based sample of men and women

The Wiener Polynomial Derivatives and Other Topological Indices in Chemical Research

Wiener polynomial derivatives and some other information and topological indices are investigated with respect to their discriminating power and property correlating ability

An improved bound on the chromatic number of the Pancake graphs

In this paper an improved bound on the chromatic number of the Pancake graph $P_n, n\geqslant 2$, is presented. The bound is obtained using a subadditivity property of the chromatic number of the Pancake graph. We also investigate an equitable coloring of $P_n$. An equitable $(n-1)$-coloring based on efficient dominating sets is given and optimal equitable $4$-colorings are considered for small $n$. It is conjectured that the chromatic number of $P_n$ coincides with its equitable chromatic number for any $n\geqslant 2$

INVESTIGATIONS OF THE CONTENT OF PRENATAL DIAGNOSIS IN THE CONTINGENT OF GENETIC COUNSELLING IN NORTH-EASTERN BULGARIA

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GENERIC COUNSELING IN PATIENTS WITH NEUROLOGICAL DISEASES

Hereditary neurological diseases nowadays are the object of intensive clinicalgenetic and molecular-genetic research. In retrospective evaluation of500families we find out that 20 of them (4 %) are with genetically determined neuropathology. Spinal muscular atrophy and progressive muscular dystrophy (Duchenne and Becker) predominate hut there are families with neural muscular atrophy, Friedreich's ataxia, neurofibromatosis, Strumpel spastic paraparesis, myopaties (inborn and Tompson's) and Huntington's chorea. Mainly the neurological and the paediatric Clinics refer patients. Only one of the visits to the Counseling center is a result of the social contacts of the patients. Almost all autosomal dominant traits segregate in the corresponding pedigrees. Only in three families it is possible to result from a new mutation. The well-known diseases with autosomal recessive and Х-linked recessive inheritance are most often sporadic cases. In two pedigrees genetic counseling is a base for prenatal ultrasound diagnosis and in one -for DNA analysis. In the rest cases genetic prognosis is made for some family members. The concrete cases and the problems of the genetic counseling are discusse

Specificity of Authorial Strategy in 19th Century Women’s Travelogues: A Study of E.A. Sverbeeva’s Travel Diary

The article is dedicated to the interpretation of the phenomenon of women’s writing and its representation in the genre of travelogue. For the first time, the ‘Diary of E.A. Sverbeeva for 1833’ is studied in the context of the evolution of women’s documentary travelogue in the 19th century, focusing on the issue of authorship. It is established that E.A. Sverbeeva’s travel diary expresses the main tendencies of the evolution of ‘women’s writing’ in the 1830s. It is revealed that Ekaterina Alexandrovna’s diary demonstrates a focus on the self, on modes of self-expression, self-analysis, and self-discovery. At the same time, the self is clearly expressed as a feminine self, which is manifested in the selection of objects from real life for describing the journey and in the ways they are characterized. As an individual authorial strategy, a combination of elements of a personal diary and a travelogue can be identified, while more often female travelers differentiated these types of entries, even designating the fundamental difference between them in the text of the travel diary. The analysis of the biographical basis of the diary and the ways in which the self is expressed in the narrative structure allows for the identification of a combination of different perspectives — that of a society lady, a ‘sensitive heroine,’ a mother, a married woman — reflecting the main tendencies in the development of ‘women’s writing’ in the historical-literary process of the 19th century

Characteristic of the snow cover for the Western Siberia territory

The warming for the Siberian territory has more rapid growth, than for Northern Hemisphere, in general. The purpose of the work is the description of characteristics of a snow cover for the south-east territory of the Western Siberia, which is great importance for many branches of the economy of Siberia. Date of appearance of snow cover, duration of a steady snow cover, thickness were analyzed in present research. The presented results are: the increase in duration of the presence the snow cover is revealed. The reason is the increase in amount of precipitation during the winter period

Taxonomical rearrangements of Solenostomataceae (Marchantiophyta) with description of a new family Endogemmataceae based on trnL-F cpDNA analysis

The results of trnL-F cpDNA analysis of the suborder Jungermanniineae allow to re-evaluate relations and taxonomy of the morphologically distinctive species Solenostoma caespiticium. A new monotypic family Endogemmataceae is described. The new combination Endogemma caespiticia is made. Provisionally, the genus Nardia is placed in Gymnomitriaceae.