Dynamic Evolution of Pairs of Trans-Neptunian Objects: the Case of Binary and Single Objects in Pair

We performed a search for pairs of trans-Neptunian objects in close orbits with semi-ma jor axes of more than 30 AU. Distances in the space of Keplerian orbits were estimated using the Kholshevnikov metrics. Found 21 pairs of trans-Neptunian objects in which one of the components is binary, for Kholshevnikov metrics in five-dimensional space of Keplerian orbits less than 0.121 AU1/2. All pairs belong to cold Classical Kuiper belt objects. Based on nominal orbits, the dynamic evolution of pairs of trans-Neptunian objects in the past 10 Myr has been studied numerically. We searched for low relativevelocity close encounters between trans-Neptunian objects in pairs as well as the minima of the Kholshevnikov metrics and the convergence of the lines of nodes and apses, to estimate the age of the pairs. © 2021. All Rights Reserved.This work has been supported by the Russian Ministry of Science and Higher Education via the State Assignment Project FEUZ-2020-0038

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In this section, we have published summaries of young scientists' works presented at a conference at Scientific Center for Children's Health in June 2007.В этом разделе опубликованы резюме работ молодых ученых, представленных на конференции в Научном центре здоровья детей РАМН в июне 2007 г

The geography of recent genetic ancestry across Europe

The recent genealogical history of human populations is a complex mosaic formed by individual migration, large-scale population movements, and other demographic events. Population genomics datasets can provide a window into this recent history, as rare traces of recent shared genetic ancestry are detectable due to long segments of shared genomic material. We make use of genomic data for 2,257 Europeans (the POPRES dataset) to conduct one of the first surveys of recent genealogical ancestry over the past three thousand years at a continental scale. We detected 1.9 million shared genomic segments, and used the lengths of these to infer the distribution of shared ancestors across time and geography. We find that a pair of modern Europeans living in neighboring populations share around 10-50 genetic common ancestors from the last 1500 years, and upwards of 500 genetic ancestors from the previous 1000 years. These numbers drop off exponentially with geographic distance, but since genetic ancestry is rare, individuals from opposite ends of Europe are still expected to share millions of common genealogical ancestors over the last 1000 years. There is substantial regional variation in the number of shared genetic ancestors: especially high numbers of common ancestors between many eastern populations likely date to the Slavic and/or Hunnic expansions, while much lower levels of common ancestry in the Italian and Iberian peninsulas may indicate weaker demographic effects of Germanic expansions into these areas and/or more stably structured populations. Recent shared ancestry in modern Europeans is ubiquitous, and clearly shows the impact of both small-scale migration and large historical events. Population genomic datasets have considerable power to uncover recent demographic history, and will allow a much fuller picture of the close genealogical kinship of individuals across the world.Comment: Full size figures available from http://www.eve.ucdavis.edu/~plralph/research.html; or html version at http://ralphlab.usc.edu/ibd/ibd-paper/ibd-writeup.xhtm

Soils of the polar archaeological site “Settlement Labytnangi 1 (Komy village)”: morphological analysis and chemical composition

Soils of archaeological sites are highly interesting objects for multidisciplinary research in various fields of soil science, ecology, archaeology, anthropology and other sciences. Currently, the soils of archaeological sites in the Arctic regions have not been studied sufficiently, although many ancient monuments beyond the polar circle have been found. This work is devoted to the study of morphological and chemical properties of soils of the archaeological site “Settlement Labytnangi 1”, which is located beyond the northern polar circle, near the cities of Labytnangi and Salekhard (Yamal-Nenets Autonomous Okrug). Development of these territories (according to archaeological research) began in the Eneolithic (Late IV – III millennia BC) and continues to the present day. Soil types on the territory of the monument are represented by soil-like bodies (urbikvazizems), podzols, turbozems, urbo-agrozems and peat soils with inclusions of archaeological and anthropogenic artifacts dating back to the XX century. Most of the studied soils were previously subjected to the processes of cryoturbation, although at present the lower boundary of the active layer of permafrost lies at a depth of 120–130 cm, according to the conducted electrophysical sounding. Significant changes occurred in the acid-base properties of the studied soils. In addition, anthropogenic activity entailed the introduction of biophilic elements and organic matter into the soil profile, in particular phosphorus, which is concentrated in the urbanized soil horizons (phosphorus concentrations above 2 800 mg/kg were recorded). The concentrations of heavy metals in the soils are at/below the conventional background (vicinity of Salekhard and Labytnangi). However, some excess concentrations of copper (up to 87.5 mg/kg), zinc (up to 303.3 mg/kg), lead (up to 76.1 mg/kg), and cadmium (up to 2.1 mg/kg) in the urbanized soil horizons have been detected. According to the results of the work, we can conclude that the soils of the archaeological site were formed under the strong influence of modern and past anthropogenic activity, which determined their morphological structure and chemical characteristics at present

Adiabatic description of nonspherical quantum dot models

Within the effective mass approximation an adiabatic description of spheroidal and dumbbell quantum dot models in the regime of strong dimensional quantization is presented using the expansion of the wave function in appropriate sets of single-parameter basis functions. The comparison is given and the peculiarities are considered for spectral and optical characteristics of the models with axially symmetric confining potentials depending on their geometric size making use of the total sets of exact and adiabatic quantum numbers in appropriate analytic approximations

Issues associated with energy efficiency programs implementation at the housing and utility enterprises

Energy saving potential is quite huge in the most sectors of the national economy, particularly in housing and utilities and industry. Due to this, energy efficiency increase at the enterprises of housing and utilities and industry through the energy efficiency programs implementation, is one of the priorities in the modern economy of Russia and its regions, and requires radical measures to improve the effectiveness of its implementation. The purpose of the authors is the scientific and practical study of the main problems of energy efficiency programs implementation at the enterprises of housing and utilities services and industry in modern conditions. To achieve this purpose the authors solved the following problems: the current state of the housing and utilities sector and industry, the relevance and the need for energy saving policy at the enterprises of housing and utilities services and industry are studied; the main problems impeding to implement the energy-saving program effectively at the enterprises of housing and utilities services and industry are determined; the possible ways of solving the problems identified in the energy efficiency programs implementation at the enterprises of housing and industry are offered. The team of authors focuses in this study on the problems of the energy audit using in practice as a basic tool for the energy saving programs development at the enterprises of housing and utilities services, industry and their subsequent implementation. The subject of author's researches is the factors that determine the energy efficiency programs implementation at the enterprises of housing and utilities services and industry at the level of individual region and the whole country, and the object is the enterprises of housing and utilities services and industry. Methodologically the scientific and practical research is based on the complex approach using the methods of comparative, statistical and logical analysis

Pairs of Trans-Neptunian Objects with close orbits

Выполнен поиск пар динамически коррелированных транснептуновых объектов с большими полуосями орбит более 30 а. е. с использованием метрик Холшевникова в пространстве кеплеровых орбит. Обнаружено 27 пар с метриками менее 0.07 (а. е.)1/2, 22 пары, в которых один из компонентов является двойным, при значениях метрик менее 0.12 (а. е.)1/2, и 11 пар двойных транснептуновых объектов при значениях метрик менее 0.3 (а. е.)1/2. Сделан вывод, что пара 2004 VA131 — 2004 VU131 может быть самой молодой парой транснептуновых объектов из известных на сегодняшний день.A search for pairs of dynamically correlated trans-Neptunian objects with semi-major axes of more than 30 au was performed. The Kholshevnikov metrics in the space of Keplerian orbits are used. Found 27 pairs with metrics less than 0.07 au1/2, 22 pairs in which one of the components is binary, for metrics less than 0.12 au1/2, and 11 pairs of binary trans-Neptunian objects with metrics less than 0.3 au1/2. It is concluded that the pair 2004 VA131 — 2004 VU131 may be the youngest pair of trans-Neptunian objects known today.Работа выполнена при поддержке Министерства науки и высшего образования Российской Федерации, тема FEUZ-2020-0038

The Genomic Signature of Crop-Wild Introgression in Maize

The evolutionary significance of hybridization and subsequent introgression has long been appreciated, but evaluation of the genome-wide effects of these phenomena has only recently become possible. Crop-wild study systems represent ideal opportunities to examine evolution through hybridization. For example, maize and the conspecific wild teosinte Zea mays ssp. mexicana, (hereafter, mexicana) are known to hybridize in the fields of highland Mexico. Despite widespread evidence of gene flow, maize and mexicana maintain distinct morphologies and have done so in sympatry for thousands of years. Neither the genomic extent nor the evolutionary importance of introgression between these taxa is understood. In this study we assessed patterns of genome-wide introgression based on 39,029 single nucleotide polymorphisms genotyped in 189 individuals from nine sympatric maize-mexicana populations and reference allopatric populations. While portions of the maize and mexicana genomes were particularly resistant to introgression (notably near known cross-incompatibility and domestication loci), we detected widespread evidence for introgression in both directions of gene flow. Through further characterization of these regions and preliminary growth chamber experiments, we found evidence suggestive of the incorporation of adaptive mexicana alleles into maize during its expansion to the highlands of central Mexico. In contrast, very little evidence was found for adaptive introgression from maize to mexicana. The methods we have applied here can be replicated widely, and such analyses have the potential to greatly informing our understanding of evolution through introgressive hybridization. Crop species, due to their exceptional genomic resources and frequent histories of spread into sympatry with relatives, should be particularly influential in these studies