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The article discusses the agro-production features of the river valley-escarpment soils of the Republic of Armenia, the negative changes occurring in the soils due to the impact of climate change and the anthropogenic factor, as well as a number of issues related to the ways of increasing soil fertility. According to the Research results, river valley-escarpment soils are in general, characterized by high natural fertility and are widely used in agricultural production as high-quality arable land. Meantime, significant changes in the agro-productive features of soils are observed as well. In order to efficiently use the land, increase and maintain the fertility, it is recommended that scientifically based complex agrotechnical measures in compliance with local conditions are applied.

This article focuses on the study of changes in the physical and chemical composition of mountain chernozems of the Republic of Armenia under the influence of an anthropogenic factor. It is established that under long-term and unsystematic agricultural use of chernozems in arable variants of soils, in comparison with virgin soil, significant changes in their physical and chemical properties are observed. Especially, absorption capacity decreases as a result of reduction of such important bases as absorbed calcium and magnesium. To improve the physical and chemical properties, increase fertility, effective use, and protection of mountain chernozems of the Lake Sevan basin of the Republic of Armenia, it is necessary to develop and apply a complete scientifically substantiated system of agrotechnical measures.

The paper analyses global online labour platforms (OLPs) through the lens of the Expansive-Restrictive Learning Environments framework. The framework articulates a set of structural factors that enable or constrain workplace learning and development. The paper draws on multistakeholder, mixed-method empirical data to illustrate how OLPs are emerging as learning environments, where new and reconfigured skills, learning practices, and new forms of learning support emerge in response to the radically distributed and fragmented nature of this work. Against portrayals of OLPs as places of deskilling work devoid of learning opportunities, the paper contributes a more nuanced understanding of the duality of OLPs as simultaneously restrictive and expansive. Three dualities of OLPs emerge from the study: (i) their espoused vision restricts organisational support for workforce development, yet stimulates self-directed learning; (ii) their enacted workplace curriculum is patchy and opaque, yet offers novel structural features supporting learning and development; (iii) workplace learning practices in OLPs are autonomous, yet not atomised. The paper illustrates how structure and individual agency interact in OLPs to create and configure learning opportunities for workers and informs practitioners about the current learning and development features and practices in OLPs.

The aim of the article is to study the direction of negative changes in water-physical properties occurring in meadow-chernozem soils under the influence of anthropogenic factor. The "soil keys" method was used to determine the location of transects. Field researches were conducted on the same-type relief areas, when comparing virgin and arable variants of soils. Soil samples were taken from the main sections by genetic horizons. In the article results of research on the influence of anthropogenic factors on the change of the water-physical properties of the mountain meadow-chernozem soils of the Republic of Armenia are presented. At the present stage the issues of storing and improving fertility of mountainous meadow-chernozem soils are very acute. These soils, under long-term use under agricultural crops, undergo considerable changes in the direction of deterioration, leading to activation of degradation processes of soils. Long-term and unsystematic agricultural use of mountainous meadow-chernozem soils leads to increase of their density. Soil porosity, its moisture capacity, mechanism of moisture movement, etc. depend on soil density. The studies conducted have shown that the density of the tilled layer of virgin soils is generally favourable for the growth and development of plants, but the upper part of the soil profile is somewhat compacted in the tilled variants. The data on porosity of mountain meadow-chernozem soils show that the soils studied are characterised by satisfactory general porosity. High porosity is especially in the whole-loam soil variants. In the arable soils some deterioration of water properties is observed. The results of maximum hygroscopicity, maximum field moisture capacity, and range of active moisture and moisture content of stable wilting slightly decrease.

Western Eurasia witnessed several large-scale human migrations during the Holocene1-5. Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes-mainly from the Mesolithic and Neolithic periods-from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a 'great divide' genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 BP, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 BP, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a 'Neolithic steppe' cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations.

Negatively charged pions from two-body decays of stopped Λ4H hypernuclei were studied in 2012 at the Mainz Microtron MAMI, Germany. The momenta of the decay-pions were measured with unprecedented precision by using high-resolution magnetic spectrometers. A challenge of the experiment was the tagging of kaons from associated K+∧ production off a Be target at very forward angles. In the year 2014, this experiment was continued with a better control of the systematic uncertainties, with better suppression of coincident and random background, improved particle identification, and with higher luminosities. Another key point of the progress was the improvement in the absolute momentum calibration of the magnetic spectrometers.

We discuss the calculation of polarization observables, including Ay, in nd scattering to next-to-next-to-next-to-leading order in pionless effective field theory.

This paper addresses learning and development processes in online platform work. Specifically, it proposes a new instrument to survey and analyze self-regulated workplace learning in crowdwork, a type of online platform labor in which a global pool of workers are matched with clients through digital platforms to carry out remunerated tasks. Although workplace learning practices of workers in traditional, organisationally embedded jobs have been studied extensively, the findings cannot be transferred to describe and explain learning behaviors within crowdwork, which is fundamentally different from traditional work in that it is autonomous, radically distributed, and no organisationally provided training opportunities exist in crowdwork. To advance the understanding of workplace learning in crowdwork we reviewed the literature on workplace learning, platform work, and self-regulated learning to develop the Workplace Learning in Crowdwork Questionnaire, which we subsequently validated with 992 crowdworkers from six European countries on three crowdwork platforms. The instrument can be used by researchers to study the nature of (self-directed) workplace learning in online labor platforms. It can also be used by crowdworkers to self-reflect on their learning and development.

At the Mainz Microtron hypernuclei can be studied by (e,e’K) reactions. By detecting the kaon which is emitted in forward direction, with the KAOS spectrometer placed at 0° scattering angle, reactions involving open strangeness production are tagged. High-resolution magnetic spectrometers are then used to coincidentally detect the monoenergetic decay-pions from mesonic two-body weak decays of light hypernuclei at rest. As a pioneering experiment has confirmed, the KAOS spectrometer is exposed to a large flux of background particles, mostly positrons from bremsstrahlung pair production. In order to increase the effciency of kaon identification the KAOS spectrometer was modified to suppress background particles at the cost of a high momentum resolution, which is less important for this experiment. This was achieved by placing up to 14 cm of lead absorbers in front of the detectors, in which positrons are blocked by forming electromagnetic showers while the effect on kaons is limited. An additional time-of-flight wall and a new threshold Čerenkov detector help to increase the detection effciency of kaons.