HYDRO + JETS (HYDJET++) event generator for Pb+Pb collisions at LHC

The Monte Carlo event generator HYDJET++ is one of the few generators, designed for the calculations of heavy-ion collisions at ultrarelativistic energies, which combine treatment of soft hydro-like processes with the description of jets traversing the hot and dense partonic medium. The model is employed to study the azimuthal anisotropy phenomena, dihadron angular correlations and event-by-event (EbyE) fluctuations of the anisotropic flow in Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV. The interplay of soft and hard processes describes the violation of the mass hierarchy of meson and baryon elliptic and triangular flows at p_T > 2 GeV/c, the fall-off of the flow harmonics at intermediate transverse momenta, and the worsening of the number-of-constituent-quark (NCQ) scaling of elliptic/triangular flow at LHC compared to RHIC energies. The cross-talk of v_2 and v_3 leads to emergence of higher order harmonics in the model and to appearance of the ridge structure in dihadron angular correlations in a broad pseudorapidity range. HYDJET++ possesses also the dynamical EbyE fluctuations of the anisotropic flow. The model results agree well with the experimental data.Comment: 8 pages, 6 figures, contribution to Proceedings of the Winter Workshop on Nuclear Dynamics 201

PALAEOENVIRONMENTAL MESSAGES FROM MOUNTAIN LAKES OF EASTERN SIBERIA

29-2

Oxygen isotope composition of diatoms as Late Holocene climate proxy at Two-Yurts Lake, Central Kamchatka, Russia

© 2014 Elsevier B.V. Especially in combination with other proxies, the oxygen isotope composition of diatom silica (δ18Odiatom) from lake sediments is useful for interpreting past climate conditions. This paper presents the first oxygen isotope data of fossil diatoms from Kamchatka, Russia, derived from sediment cores from Two-Yurts Lake (TYL). For reconstructing Late Holocene climate change, palaeolimnological investigations also included diatom, pollen and chironomid analysis. The most recent diatom sample (δ18Odiatom=+23.3‰) corresponds well with the present day isotopic composition of the TYL water (mean δ18O=-14.8‰) displaying a reasonable isotope fractionation in the system silica-water. Nonetheless, the TYL δ18Odiatom record is mainly controlled by changes in the isotopic composition of the lake water. TYL is considered as a dynamic system triggered by differential environmental changes closely linked with lake-internal hydrological factors. The diatom silica isotope record displays large variations in δ18Odiatom from +27.3‰ to +23.3‰ from about ~4.5kyr BP until today. A continuous depletion in δ18Odiatom of 4.0‰ is observed in the past 4.5kyr, which is in good accordance with other hemispheric environmental changes (i.e. a summer insolation-driven Mid- to Late Holocene cooling). The overall cooling trend is superimposed by regional hydrological and atmospheric-oceanic changes. These are related to the interplay between Siberian High and Aleutian Low as well as to the ice dynamics in the Sea of Okhotsk. Additionally, combined δ18Odiatom and chironomid interpretations provide new information on changes related to meltwater input to lakes. Hence, this diatom isotope study provides further insight into hydrology and climate dynamics of this remote, rarely investigated area

Holocene climate conditions in central Yakutia (Eastern Siberia) inferred from sediment composition and fossil chironomids of Lake Temje

A 380 cm long sediment core from Lake Temje (central Yakutia, Eastern Siberia) was studied to infer Holocene palaeoenvironmental change in the extreme periglacial setting of eastern Siberia during the last 10,000 years. Data on sediment composition were used to characterize changes in the depositional environment during the ontogenetic development of the Lake Temje. The analysis of fossil chironomid remains and statistical treatment of chironomid data by the application of a newly developed regional Russian transfer functions provided inferences of mean July air temperatures (TJuly) and water depths (WD). Reconstructed WDs show minor changes throughout the core and range between 80 and 120 cm. All the fluctuations in reconstructed water depth lie within the mean error of prediction of the inference model (RMSEP = 0.35) so it is not possible to draw conclusions from the reconstructions. A qualitative and quantitative reconstruction of Holocene climate in central Yakutia recognized three stages of palaeoenvironmental changes. The early Holocene between 10 and 8 ka BP was characterized by colder-than-today and moist summer conditions. Cryotextures in the lake sediments document full freezing of the lake water during the winter time. A general warming trend started around 8.0 ka BP in concert with enhanced biological productivity. Reconstructed mean TJuly were equal or up to 1.5 °C higher than today between 6.0 ka and 5.0 ka BP. During the entire late Holocene after 4.8 ka BP, reconstructed mean TJuly remained below modern value. Limnological conditions did not change significantly. The inference of a mid-Holocene climate optimum supports scenarios of Holocene climatic changes in the subpolar part of eastern Siberia and indicates climate teleconnections to the North Atlantic realm. © 2012 Elsevier Ltd and INQUA

Changes in temperature and water depth of a small mountain lake during the past 3000 years in Central Kamchatka reflected by a chironomid record

© 2016 Elsevier Ltd and INQUA.We investigated chironomid assemblages of a well-dated sediment core from a small seepage lake situated at the eastern slope of the Central Kamchatka Mountain Chain, Far East Russia. The chironomid fauna of the investigated Sigrid Lake is dominated by littoral taxa that are sensitive to fluctuations of the water level. Two groups of taxa interchangeably dominate the record responding to the changes in the lake environment during the past 2800 years. The first group of littoral phytophilic taxa includes Psectrocladius sordidellus-type, Corynoneura arctica-type and Dicrotendipes nervosus-type. The abundances of the taxa from this group have the strongest influence on the variations of PCA 1, and these taxa mostly correspond to low water levels, moderate temperatures and slightly acidified conditions. The second group of taxa includes Microtendipes pedellus-type, Tanytarsus lugens-type, and Tanytarsus pallidicornis-type. The variations in the abundances of these taxa, and especially of M. pedellus-type, are in accordance with PCA 2 and correspond to the higher water level in the lake, more oligotrophic and neutral pH conditions. Water depths (WD) were reconstructed, using a modern chironomid-based temperature and water depth calibration data set (training set) and inference model from East Siberia (Nazarova et al., 2011). Mean July air temperatures (T July) were inferred using a chironomid-based temperature inference model based on a modern calibration data set for the Far East (Nazarova et al., 2015). The application of transfer functions resulted in reconstructed T July fluctuations of approximately 3 °C over the last 2800 years. Low temperatures (11.0-12.0 °C) were reconstructed for the periods between ca 1700 and 1500 cal yr BP (corresponding to the Kofun cold stage) and between ca 1200 and 150 cal yr BP (partly corresponding to the Little Ice Age [LIA]). Warm periods (modern T July or higher) were reconstructed for the periods between ca 2700 and 1800 cal yr BP, 1500 and 1300 cal yr BP and after 150 cal yr BP. WD reconstruction revealed that the lake level was lower than its present level at the beginning of the record between ca 2600 and 2300 cal yr BP and ca 550 cal yr BP. Between ca 2300 and 700 cal yr BP as well as between 450 and 150 cal yr BP, the lake level was higher than it is today, most probably reflecting more humid conditions

Changes in temperature and water depth of a small mountain lake during the past 3000 years in Central Kamchatka reflected by a chironomid record

© 2016 Elsevier Ltd and INQUA We investigated chironomid assemblages of a well-dated sediment core from a small seepage lake situated at the eastern slope of the Central Kamchatka Mountain Chain, Far East Russia. The chironomid fauna of the investigated Sigrid Lake is dominated by littoral taxa that are sensitive to fluctuations of the water level. Two groups of taxa interchangeably dominate the record responding to the changes in the lake environment during the past 2800 years. The first group of littoral phytophilic taxa includes Psectrocladius sordidellus-type, Corynoneura arctica-type and Dicrotendipes nervosus-type. The abundances of the taxa from this group have the strongest influence on the variations of PCA 1, and these taxa mostly correspond to low water levels, moderate temperatures and slightly acidified conditions. The second group of taxa includes Microtendipes pedellus-type, Tanytarsus lugens-type, and Tanytarsus pallidicornis-type. The variations in the abundances of these taxa, and especially of M. pedellu s-type, are in accordance with PCA 2 and correspond to the higher water level in the lake, more oligotrophic and neutral pH conditions. Water depths (WD) were reconstructed, using a modern chironomid-based temperature and water depth calibration data set (training set) and inference model from East Siberia (Nazarova et al., 2011). Mean July air temperatures (T July) were inferred using a chironomid-based temperature inference model based on a modern calibration data set for the Far East (Nazarova et al., 2015). The application of transfer functions resulted in reconstructed T July fluctuations of approximately 3 °C over the last 2800 years. Low temperatures (11.0–12.0 °C) were reconstructed for the periods between ca 1700 and 1500 cal yr BP (corresponding to the Kofun cold stage) and between ca 1200 and 150 cal yr BP (partly corresponding to the Little Ice Age [LIA]). Warm periods (modern T July or higher) were reconstructed for the periods between ca 2700 and 1800 cal yr BP, 1500 and 1300 cal yr BP and after 150 cal yr BP. WD reconstruction revealed that the lake level was lower than its present level at the beginning of the record between ca 2600 and 2300 cal yr BP and ca 550 cal yr BP. Between ca 2300 and 700 cal yr BP as well as between 450 and 150 cal yr BP, the lake level was higher than it is today, most probably reflecting more humid conditions

Representation theory of some infinite-dimensional algebras arising in continuously controlled algebra and topology

In this paper we determine the representation type of some algebras of infinite matrices continuously controlled at infinity by a compact metrizable space. We explicitly classify their finitely presented modules in the finite and tame cases. The algebra of row-column-finite (or locally finite) matrices over an arbitrary field is one of the algebras considered in this paper, its representation type is shown to be finite.Comment: 33 page

The Concept of Small Creative Groups

В статье рассмотрена сущность малых творческих групп. Автор приводит три основных критерия для формирования малой творческой группы: по степени сходности успеваемости и сходимости темпов работы, а также взаимной симпатии. Представлена классификация малых творческих групп по численности. Рассмотрена сущность малой творческой группы через ее отличительные признаки от традиционной модели учебно-познавательной деятельности; факторы формирования малой творческой группы и критерии формирования малых творческих групп по составу.The article discusses the forms of small creative groups. The author gives three main criteria for the formation of a small creative group: according to the degree of similarity of academic performance and convergence of the pace of work, as well as mutual sympathy. The classification of small creative groups by number is also presented. The essence of a small creative group is considered through its distinctive features from the traditional model of educational and cognitive activity. When substantiating the essence of the concept, the factors of the formation of a small creative group and the criteria for the formation of small creative groups by composition are considered

Introducing Group Work Methods in Literature Lessons

В статье рассмотрены структурные процессы методик работы в малых творческих группах на уроках литературного чтения. Также, представлены этапы по формированию работы в малых творческих группах на уроках литературного чтения. При обосновании сущности методики рассмотрена технология использования группового опроса на уроках литературного чтения. Произведено исследование отличительных особенностей методики работы в малых творческих группах на уроках литературного чтения.The article discusses the structural processes of methods of work in small creative groups at the lessons of literary reading. Also, the stages for the formation of work in small creative groups at the lessons of literary reading are presented. When substantiating the essence of the methodology, the technology of using a group survey in literary reading lessons is considered. A study of the distinctive features of the methodology of work in small creative groups at the lessons of literary reading has been carried out

Paleolimnological studies in Russian northern Eurasia: A review

© 2017, Pleiades Publishing, Ltd. This article presents a review of the current data on the level of paleolimnological knowledge about lakes in the Russian part of the northern Eurasia. The results of investigation of the northwestern European part of Russia as the best paleolimnologically studied sector of the Russian north is presented in detail. The conditions of lacustrine sedimentation at the boundary between the Late Pleistocene and Holocene and the role of different external factors in formation of their chemical composition, including active volcanic activity and possible large meteorite impacts, are also discussed. The results of major paleoclimatic and paleoecological reconstructions in northern Siberia are presented. Particular attention is given to the databases of abiotic and biotic parameters of lake ecosystems as an important basis for quantitative reconstructions of climatic and ecological changes in the Late Pleistocene and Holocene. Keywords: paleolimnology, lakes, bottom sediments, northern