Choice of clustering methods

Выбор алгоритма машинного обучения для решения некоторой задачи является проблемой. В данном докладе рассматриваются алгоритмы кластерного анализа и методика их выбора для эффективного решения прикладных задач. There is an existing problem of choosing a machine learning algorithm as a solution to a task. In this study, a review of numerous clustering algorithms is conducted and a method for choosing a clustering algorithm for efficient solving of practical problems is developed and attempted

Survival and long-term maintenance of tertiary trees in the Iberian Peninsula during the Pleistocene. First record of Aesculus L.

The Italian and Balkan peninsulas have been places traditionally highlighted as Pleistocene glacial refuges. The Iberian Peninsula, however, has been a focus of controversy between geobotanists and palaeobotanists as a result of its exclusion from this category on different occasions. In the current paper, we synthesise geological, molecular, palaeobotanical and geobotanical data that show the importance of the Iberian Peninsula in the Western Mediterranean as a refugium area. The presence of Aesculus aff. hippocastanum L. at the Iberian site at Cal Guardiola (Tarrasa, Barcelona, NE Spain) in the Lower– Middle Pleistocene transition helps to consolidate the remarkable role of the Iberian Peninsula in the survival of tertiary species during the Pleistocene. The palaeodistribution of the genus in Europe highlights a model of area abandonment for a widely-distributed species in the Miocene and Pliocene, leading to a diminished and fragmentary presence in the Pleistocene and Holocene on the southern Mediterranean peninsulas. Aesculus fossils are not uncommon within the series of Tertiary taxa. Many appear in the Pliocene and suffer a radical impoverishment in the Lower–Middle Pleistocene transition. Nonetheless some of these tertiary taxa persisted throughout the Pleistocene and Holocene up to the present in the Iberian Peninsula. Locating these refuge areas on the Peninsula is not an easy task, although areas characterised by a sustained level of humidity must have played an predominant role

The effect of water extract from bentonite on embryonic and larval development of the green toad (bufoviridis) with different phenotypes

Ontogenesis is a complex process of morphophysiological transformations. Embryonic and postembryonic development is continuously affected by both endogenous and environmental factors, which lead to variability in morphometric parameters. The research was conducted in the laboratory of ecological embryology of the Federal State Budgetary Educational Institution of Higher Education of the North Osetian Federal University (Vladikavkaz). The results showed that under the influence of bentonite extract, the morphological parameters of green toad larvae with a brown phenotype are more variable than in larvae with an olive green phenotype in both the control and experimental groups. Thus, the embryos and larvae of the green toad with the olive green phenotype are more stable than the larvae that had the brown phenotype, both in natural circumstances and under the influence of bentonite clay extracts