146 research outputs found

    The evolution of early Spermophilus in eastern Europe and the antiquity of the Old World ground squirrels

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    Spermophilus is the most diverse and abundant genus of Eurasian sciurids. Even though many species have been described, the early evolution of the group is poorly understood. Here we present a review of the evolution and taxonomy of early Spermophilus, based on analysis of more than 1500 specimens from the late Pliocene and Early–Middle Pleistocene of Ukraine and European Russia, representing the most complete and continuous fossil record of the early Old World ground squirrels known to date. In addition to documenting previously unpublished specimens of Spermophilus nogaici, we describe a new species, Spermophilus praecox sp. nov., the oldest member of the genus, from the late Pliocene and Early Pleistocene (middle Villanyian to earliest Biharian) of southern Ukraine. It is intermediate in size between a somewhat smaller Spermophilus nogaici and larger Spermophilus polonicus and Spermophilus primigenius. Morphologically, the new species can be distinguished from all known Spermophilus by the retention of primitive traits including a small P3; rudimentary lingual metaloph; large metaconule and mesostyle; presence of P4–M2 endoloph; and premolariform p4 lacking a lingual metalophid. The patterns of dental evolution in eastern European early Spermophilus throughout 2.15 My indicates the existence of a single gradually evolving S. praecox–S. nogaici lineage characterized by a decrease of molar size but enlargement of premolars; the tendency toward high-crowned teeth with more expanded anterior and reduced posterior lobes; well-developed transverse ridges and anterostyles; reduced endolophs, anteroconules, metaconules, and mesostyles of P4–M2; molariform p4; complete m1–m2 metalophids; and stronger m3 hypoconid, hypoconulid, and entoconulid. Dental character regression suggests that Spermophilus evolved from a relatively large-sized sciurid having generalized Otospermophilus-like dentition, probably an unknown North American member of stem Marmotina. Copyright © 2019 M.V. Sinitsa and N.V. Pogodina. This is an open-access article distributed under the terms of the Creative Commons Attribution License (for details please see http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Government Council on Grants, Russian FederationWe would like to thank Dmitry V. Ivanoff, Oleksandr M. Kovalchuk, Vadym O. Yanenko (all National Museum of Natural History, Kiev, Ukraine), Olga V. Makarova (Zoological Institute of the Russian Academy of Sciences, Saint Petersburg, Russia), Mihály Gasparik and Piroska Pazonyi (both Hungarian Museum of Natural History, Budapest, Hungary) for access and guidance during MVS’s visits to their respective institutions. We are also grateful to Alexey S. Tesakov (Geological Institute of the Russian Academy of Sciences, Moscow, Russia) for discussions on fossil ground squirrels and southern Ukraine stratigraphy. Finally, we thank Thomas H. Goodwin (Andrews University, Berrien Springs, USA), William W. Korth (Rochester Institute of Vertebrate Paleontology, New York, USA), and the Editor, Olivier Lambert (Royal Belgian Institute of Natural Sciences, Brussels, Belgium) for their constructive comments that greatly improved the manuscript. The research was supported by Act 211 of the Government of the Russian Federation, contract No. 02.A03.21.0006; and by INQUA Project 1606:‘Ground Squirrels on the March: Expansion and Speciation in the Quaternary of the Circum-Pontic Area and Surroundings’

    Organization and management of clusters in Russia in the context of import substitution

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    The article covers the trends of the agribusiness development in Russia. It is shown that it is desirable to develop organizational-economic forms of entrepreneurship based on the cluster approach in the modern realities. The most famous agribusiness clusters in the world are explored. Regions of Russia that have achieved the most significant results in agribusiness clustering are mentioned. It is found that the establishment of agribusiness in Russia is defined by the political decision of regional authorities rather than based on research and development. An algorithm for establishing the agribusiness cluster is proposed, which includes four stages: methodological, analytical, organizational-economic and control. The key areas of state support for the development of agribusiness clusters in Russia are defined.peer-reviewe

    Obesity and functional bowel disorders in adolescents: a pilot study

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    Background: Studies of the relationship between obesity and functional bowel disorders, carried out in different age groups, provide conflicting results. It remains unclear what factors are responsible for the transition from a tendency to constipation in children to a tendency to diarrhea in adults with obesity.Aim: To establish factors related to stool consistency as a surrogate marker of colon transit in adolescents with obesity.Materials and methods: A single-center observational cross-sectional study was carried out. We consecutively recruited adolescents, aged 11–17 years with obesity. Socio-demographic characteristics, lifestyle and nutritional characteristics were assessed using questionnaires. Bowel symptoms were assessed using questionnaires and interviews. Stool consistency was assessed using the Bristol Stool Form Scale. Serum concentrations of ALT, AST, bilirubin, cholesterol, glucose, HbA1c, leptin, and insulin were determined. The HOMA-IR index was used to determine insulin resistance.Results: One hundred and ten adolescents with obesity were enrolled in the study. Of these, 69.1% had a pathological consistency of feces, with the prevalence of forms characterizing delayed gut transit (49.1%). The predominance of loose stools was reported by 5.5% of patients. The combination of different forms of stool (unstable stool) was described by 14.5% of adolescents. Hard stools were common among adolescents from single-parent families and adolescents who rarely consume dairy products. The presence of loose stools has been associated with insulin resistance.Conclusion: Most obese adolescents who do not have abdominal complaints have colon transit disorders. Medical professionals should actively ask these patients about stool frequency and properties. With constipation, dietary correction is justified. Research is needed to investigate in-depth gut microbiota as a possible link between obesity and diarrhea

    The Impact of Stress on the Health of Students and Ways to Overcome It

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    В данной статье рассматривается влияние стресса на здоровье обучающихся. Указаны причины возникновения стресса. Представлены способы его преодоления.This article examines the impact of stress on the health of students. The causes of stress are indicated. The ways of overcoming it are presented

    Comparison of microecological intestinal indices in children with different value of body mass index

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    The body mass index (BMI) is one of the key and at the same time simple and significant indicators of the state of the human body. Both large and small quantities of BMI is associated with high morbidity. The aim of the study was to analyze microecological disorders of intestinal biocenosis in children of different ages using the value of BMI as the criterion of comparison. We researched scatological material from 158 children and adolescents aged from 5 to 17 years (77 boys and 81 girls). The material was divided into three comparison groups depending on the BMI value: group 1 - body mass deficit (n = 34); group 2 - patients having body mass excess (n = 37); group 3 - with normal body mass (n = 87). It has been shown that more than 80 % of children with different BMI value were recorded to have dysbiotic disturbances of the intestinal microbiota of degrees 1 and 2. However, in the group of children with normal body mass, frequency of detection of intestinal dysbiosis was significantly lower; in the group of children with underweight dysbiotic disorders were found significantly more often than in overweight and obese children (p < 0.05). In children with body mass deficit we observed not only increasing concentration of opportunistic pathogenic bacteria, but also an increased occurrence of representative of Enterobacteriаceaе. family. 58.8 % of cases had two- and three-component associations of opportunistic pathogenic bacteria, which is an indication the expressed violations of the intestine microbiocenosis formation. The data obtained show that,you can use BMI, an important criterion reflecting the severity of the disease, in the assessment of intestinal microflora in combination with other studies

    Comorbidity of functional bowel disorders and obesity in terms of microbiome

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    Bacterial ecosystem of the gut plays a fundamental role in the normal functioning of the metabolic and immune systems. Functional bowel disease and obesity are highly prevalent in the population and place a heavy burden on healthcare system. Both comorbidity and multimorbidity are considered to be common for obesity and intestinal functional disorders. Changes in the microbiota can be both the cause and consequence of each disease: intestinal functional disorder changes the composition of the microbiota, resulting in obesity, and vice versa. Intestinal functional disorders and obesity are characterized by a similar type of dysbiosis.The aim of the review is to analyze the research findings available to date in order to establish the relationship between the gut microbiome, functional bowel disease and obesity. The researches have shown that patients with intestinal functional disorders have a different gut microbiome than healthy individuals. For intestinal functional disorders, the general patterns of the intestinal microbiota composition were described, and the characteristic taxonomic groups of bacteria were identified. On the other side, it must be noted that there is no clear correlation between intestinal functional disorders and obesity in terms of the microbiota. This can be explained by the high heterogeneity of intestinal functional disorders, as well as by the lack of a unified approach to creating a study design, by different sizes of population samples and also by different diagnostic criteria. The necessity to determine the criteria in the development of the design of future studies is discussed

    Tickborne Encephalitis in Naturally Exposed Monkey (Macaca sylvanus)

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    We describe tickborne encephalitis (TBE) in a monkey (Macaca sylvanus) after natural exposure in an area at risk for TBE. TBE virus was present in the brain and could be identified as closely related to the European subtype, strain Neudoerfl

    ФИНАНСОВО-ЭКОНОМИЧЕСКИЕ МЕХАНИЗМЫ СОЗДАНИЯ ИННОВАЦИОННЫХ ТЕРРИТОРИАЛЬНЫХ КЛАСТЕРОВ

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    Nowadays, the introduction of innovative business models is a factor of sustainable development of the Russian economy and its regions. One of such models is creation of clusters. The cluster approach came into widespread use in the 80s of the last century. The innovative development and understanding of the importance of the economy at the regional level made it possible to apply the cluster theory to these problems. At present, the cluster approach is regarded as one of the most effective tools for the development of national and regional economies. This is the way to allow the country to maintain the domestic industry and promote the development of entrepreneurship in the regions. Although the budget funding of the country’s industrial potential is characterized by relatively high indices it is not sufficient for the concurrent implementation of many large-scale projects, including the creation of innovative regional clusters and ensuring high rates of economic development of the country and individual regions. The paper discusses the use of the cluster approach to boost the innovative development of the region, methods for building a cluster management system, organizational and financial mechanisms for the development of a cluster. The analysis of the Russian experience in the use of innovative financial and economic mechanisms for creation and development of regional clusters made it possible to identify the main trends in the application of such mechanisms, evaluate their effectiveness and outline possible areas of improvement.В современных условиях одной из составляющих обеспечения устойчивого развития экономики России и ее регионов является внедрение инновационных моделей хозяйствования, одна из которых - создание кластеров. Кластерный подход получил широкое распространение в 80-х годах XX в. Инновационное развитие и понимание важности развития экономики на региональном уровне позволили применить к этим задачам кластерную теорию. В настоящее время кластерный подход рассматривается в качестве одного из наиболее эффективных инструментов развития национальных и региональных экономик. Именно такой путь позволит стране сохранить отечественное производство и стимулировать развитие предпринимательства в регионах. Несмотря на то что бюджетное финансирование развития промышленного потенциала страны характеризуется относительно высокими показателями, его недостаточно для одновременной реализации многих масштабных проектов, в том числе создания инновационных территориальных кластеров и обеспечения высоких темпов экономического развития страны и отдельных регионов. В статье рассмотрены вопросы применения кластерного подхода для активизации инновационного развития регионов, направления построения системы управления кластером и организационно-финансовые механизмы развития кластера. Анализ российского опыта использования финансово-экономических механизмов создания и развития инновационных территориальных кластеров позволил выявить основные тенденции в применении таких механизмов, оценить их эффективность и наметить возможные направления совершенствования

    Homochiral growth through enantiomeric cross-inhibition

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    The stability and conservation properties of a recently proposed polymerization model are studied. The achiral (racemic) solution is linearly unstable once the relevant control parameter (here the fidelity of the catalyst) exceeds a critical value. The growth rate is calculated for different fidelity parameters and cross-inhibition rates. A chirality parameter is defined and shown to be conserved by the nonlinear terms of the model. Finally, a truncated version of the model is used to derive a set of two ordinary differential equations and it is argued that these equations are more realistic than those used in earlier models of that form.Comment: 20 pages, 6 figures, Orig. Life Evol. Biosph. (accepted
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