Rozmnażanie in vitro alternatywnych roślin ogrodniczych (Actinidia, Chaenomeles, Aronia)

Succesful propagation of selected clones and cultivars of Actinidia kolomicta (Maxim.) Maxim., A. arguta (Siebold et Zucc.) Planch, ex Miq., Chaenomeles japonica (Thunb.) Lindl, ex Spach and Aronia melanocarpa (Michx.) Elliott has been achieved by in vitro methods. It has been demonstrated that the intensity and pathway of microvegetative propagation depend on the properties of plant species, genotype and sex. Under in vitro conditions, actinidia multiplicated by forming shoots from apical meristems and auxiliary buds of shoots, dwarf Japanese quince and black chokeberry - by new adventitious shoots. For in vitro development, male plants of actinidia species demanded opposite ratios of auxins and cytokinins than the female plants. They worse adapted to in vitro conditions. Multiplication coefficient in the fourth week was as follows: Actinidia - 1.3-4.5; Chaenomeles – 1.9-4.1; Aronia - 14.3.Przy pomocy metod in vitro udało się rozmnożyć wybrane klony i odmiany Actinidia kolomicta (Maxim) Maxim, A. arguta (Siebold et Zucc.) Planch, ex Miq., Chaenomeles japonica (Thunb.) Lindl, ex Spach oraz Aronia melanocarpa (Michx.) Elliott. Wykazano, że intensywność i przebieg rozmnażania zależały od właściwości gatunku rośliny, genotypu i płci. W warunkach in vitro aktynidia rozmnażała się poprzez tworzenie pędów z merystemów wierzchołka i pomocniczych pęków na pędach, karłowata pigwa japońska i aronia - poprzez nowe pędy przybyszowe. W celu rozmnożenia w warunkach in vitro rośliny męskie wymagały odwrotnych proporcji auksyn i cytokinin niż rośliny żeńskie. Gorzej dostosowywały się do warunków in vitro. Współczynnik rozmnażania w czwartym tygodniu był następujący: Actinidia - 1.3-4.5; Chaenomeles - 1.9-4.1; Aronia - 14.3

Two-dimensional materials from high-throughput computational exfoliation of experimentally known compounds

Two-dimensional (2D) materials have emerged as promising candidates for next-generation electronic and optoelectronic applications. Yet, only a few dozen 2D materials have been successfully synthesized or exfoliated. Here, we search for 2D materials that can be easily exfoliated from their parent compounds. Starting from 108,423 unique, experimentally known 3D compounds, we identify a subset of 5,619 compounds that appear layered according to robust geometric and bonding criteria. High-throughput calculations using van der Waals density functional theory, validated against experimental structural data and calculated random phase approximation binding energies, further allowed the identification of 1,825 compounds that are either easily or potentially exfoliable. In particular, the subset of 1,036 easily exfoliable cases provides novel structural prototypes and simple ternary compounds as well as a large portfolio of materials to search from for optimal properties. For a subset of 258 compounds, we explore vibrational, electronic, magnetic and topological properties, identifying 56 ferromagnetic and antiferromagnetic systems, including half-metals and half-semiconductors

Evaluation of the relationship between youth entrepreneurship and emigration intentions: theoretical-methodological aspects

Purpose – the purpose of this article is to investigate the relationship between youth entrepreneurship and emigration attitudes by presenting a method for evaluating the link between youth participation in entrepreneurship promotion initiatives, entrepreneurship and emigration attitudes, and also to check its validity. Research methodology – the quantitative test method presented in the article consists of 3 key parts that have their own specifics of evaluation and different methodologies. Findings – the results of the study did not show the correlation between the analyzed elements. Research limitations – although a method test made it possible to verify its suitability, a more representative sample of respondents is needed to provide valid results about the correlation of above mentioned 3 elements. Practical implications – based on the methodology evaluated, everyone familiar with the material will be able to initiate surveys and/or scientifically based researches at a different territorial level on youth entrepreneurship and emigration intentions and to evaluate the extent of the youth involvement in entrepreneurship promotion initiatives and its relationship with the entrepreneurial spirit of the individual. Originality/Value – this study contributed to the existing research on entrepreneurship, supplementing it with new insights on the existence of a relation between entrepreneurship promotion, entrepreneurship, and the tendency to emigrate, which, as far as the authors are aware, was researched neither in Lithuania nor globally

An improved summing Compton gamma-ray spectrometer

A simple ad hoc analog computer using semiconductor logarithmic elements is used to examine the coincident pulse-pairs from a summing Compton spectrometer for compatibility with the Compton scattering equation for the particular scattering angle being used. With the aid of this circuit, the total absorption fraction of the spectrometer can be raised almost to 100% by identifying and rejecting electronically those coincidences in which some of the energy of the incident photon has escaped from either detector. At the same time, the polarization sensitivity of the Compton spectrometer is also improved since coincidences in which multiple scattering has taken place are rejected. The system can also be used to make the spectrometer telescopic, selecting electronically rather than by heavy collimators the incident direction of interest. The latter capability may be useful in situations where there is an omnidirectional flux. Though scintillation crystals have been used here to demonstrate the principle, the technique would be equally applicable (and perhaps most useful) in a light and compact Compton spectrometer using semiconductor detectors.Peer reviewed: YesNRC publication: Ye