Oxygen emission in remnants of thermonuclear supernovae as a probe for their progenitor system

Recent progress in numerical simulations of thermonuclear supernova explosions brings up a unique opportunity in studying the progenitors of Type Ia supernovae. Coupling state-of-the-art explosion models with detailed hydrodynamical simulations of the supernova remnant evolution and the most up-to-date atomic data for X-ray emission calculations makes it possible to create realistic synthetic X-ray spectra for the supernova remnant phase. Comparing such spectra with high quality observations of supernova remnants could allow to constrain the explosion mechanism and the progenitor of the supernova. The present study focuses in particular on the oxygen emission line properties in young supernova remnants, since different explosion scenarios predict a different amount and distribution of this element. Analysis of the soft X-ray spectra from supernova remnants in the Large Magellanic Cloud and confrontation with remnant models for different explosion scenarios suggests that SNR 0509-67.5 could originate from a delayed detonation explosion and SNR 0519-69.0 from an oxygen-rich merger.Comment: 8 pages, 4 figures, MNRAS accepte

«Axiological Turn» in Russian Education: Position of Subjectivism

Reflective theorizations about the state and prospects for the development of domestic education clearly recognize two trends in its future – continuity and individualization. In addition, the tendency of an “axiological turn” in the sense of education as a value and the value of education itself is clearly articulated. Modern pluralism of educational practices indicates the possibility of an individual to become the main subject of a new type of educational interaction based on independent institutionalization. Does the trend of “axiological turn” have ontological grounds for the sanctioned possibility of free change in the subjectivity of an individual in the educational space on fundamentally new methodological grounds? Or is it a continuation of the methodological tradition of axiological subjectivism? In order to find the foundations of a new axiological tradition in the educational space, a theoretical formalization of the category of “value” in the historical and philosophical tradition is being developed, and the results of this formalization are projected onto modern Russian education.On the one hand, the interpretation of educational values as skills, abilities and competencies is nothing more than an objective requirement of a dynamically changing socio-cultural situation with its ever-increasing uncertainty. On the other hand, the “axiological turn”, to a much greater extent, is associated with a change in the value orientations of the individual him/herself. This, with a special degree of efficiency and dynamism, is expressed in a change in the nature of educational-individual trajectories towards the professionalization of educational practices with a simultaneous strengthening of their meta-component. It is emphasized that meta-skills, along with existential skills, are the general vectors in the development of the axiological ecosystem of education. Based on the historical and philosophical review of the understanding of values and ideas about education as a way of reproducing culture (in the dialectic of alienation and appropriation of social values), the conclusion is formulated that modern concepts of the reversal of educational practices are, to a certain extent, private explications of axiological subjectivism

Determining the toxicity of the biomass of Cladophora sp.

Finding new or alternative feeds, feed additives, and raw materials safe for health and the environment is significant in intensifying livestock production. At the same time, the fodder base obtained from aquatic ecosystems – algae – deserves special attention. The advantage of using algae as fodder is using small areas for their cultivation and a high reproduction rate. In addition, algae are grown where other plants cannot grow, and the productivity of algae is several times higher than that of higher plants. Algae can produce beneficial compounds and biomass, which are also used to increase the nutritional value of food products. Biomass obtained from algae is a source of necessary vitamins, minerals, proteins, polyunsaturated fatty acids, antioxidants, and other necessary nutrients. The composition of algae depends on the environment from which this biomass is collected, the conditions of algae cultivation, the season, the species of algae, and many other factors. In addition, it should be noted that some algae, out of the total amount, are toxic when consumed. That is why it is essential to research their toxicity. The article presents the results of studying the toxicity of the biomass of Cladophora sp. on the body of guppy fish. When studying the effect of biomass Cladophora sp. on the body of guppy fish, it was established that its use for 96 hours in doses of 5, 10, 25, 50, and 100 mg/l did not cause their death, and its LC50 is higher than 100 mg/l. In addition, no changes were detected in the behavior of the fish; they were active, mobile, and actively responding to external stimuli. The fish of the experimental groups were not distinguished from those of the control group