bluuebunny/crossref_metadata_2025 huggingface dataset:
The environmentally safe method of control of broomrape (Orobanche cumana Wallr.) parasitizing on sunflower
Authors: Strelnikov Evgeniy , Antonova Tatiana , Gorlova Lyudmila , Trubina Victoria
Published: June 2020

Orobanche cumana Wallr., an obligate parasite of sunflower, is widely spread in most countries cultivating this crop. It is one of the main factors limiting the cultivation of sunflower. The aim of our research was to determine the influence of application of oil crops (Brassicaceae) green manures on the sunflower infection with broomrape under greenhouse conditions. We used the green mass of white, black, common mustard and winter rapeseed as a green manure. We added the crushed green mass of these crops (62.5-90.0 g) to vessels with a soil-sand mixture mixed with broomrape seeds. After 15 days, we sowed the seeds of sunflower variety susceptible to all races of broomrape. We did not add the green manures in the control. The green manure of white mustard (variety Ruslana) showed the highest percentage of decrease in the infection degree – 44.7 %. The common mustard (Yunona) and black mustard (Niagara) reduced the infection by 25.9 and 27.0 %, respectively, the rapeseed (Tavrion) – by 24 %. We recommend using the green manures of these crops to reduce infection of sunflower crops with broomrape and as an environmentally safe method of clearing the field from its seeds.
Susceptibility of three species of the genus Ostrinia (Lepidoptera: Crambidae) to Nosema pyrausta (Microsporidia: Nosematida)
Authors: Grushevaya Inna , Ignatieva Anastasia , Tokarev Yuri
Published: June 2020

Microsporidia are obligate intracellular parasites that affect the population density of many insect pests. In particular, infection with Nosema pyrausta is one of the major mortality factors for the European corn borer Ostrinia nubilalis, the Asian corn borer Ostrinia furnacalis and the adzuki bean borer Ostrinia scapulalis. The purpose of the work is to compare the susceptibility to N. pyrausta and pathogenesis of three species of moths of the genus Ostrinia. Studies conducted over 2 years have shown that in all three species of host insects under laboratory conditions, both during oral infection and transovarian transmission of infection (in the daughter generations of experimentally infected insects), only diplokaryotic spores formed corresponding to the main morphotype of the genus Nosema. Mean lethal time increased with instar of larvae used for infection but didn’t differ between the three species. The rates of transovarial transmission of N. pyrausta were also similar. Thus, all the insect species examined may equally participate in the parasite persistence in nature and serve as model laboratory hosts for parasitological research and mass propagation of the microsporidium.
Biological features of metabolism in rhesus monkeys as a result of the inclusion of fish meal in the structure of feeding rations
Authors: Gaponov Nikolay , Yagovenko German
Published: June 2020

The article presents a study of the effect of fish meal, in the amount of 18% in the structure of the diet, on the organism of primates. Fishmeal is known to be rich in energy and protein. One kilogram of it contains up to 700 g of pure protein and up to 15 MJ of exchangeable energy. It should be noted that fish meal is easily digested and well absorbed by the body of animals. Among other things, it contains a lot of calcium, fat, vitamins of group B, phosphorus and other elements. But the use of fish meal in the rations of primates, in an amount above 10%, has not been sufficiently studied. Therefore, the purpose of our research was to study the effect of fish meal on hematological, biochemical blood parameters, to determine the variability of rations of rhesus monkeys, and based on the data obtained to determine the prospects for its further use in feeding primates. For this purpose, developed technological methods of preparation of feed with fish meal. The chemical composition of the obtained feeds has been determined. The nutritional value of the feed obtained was studied by the main indicators of chemical composition. The effect of fishmeal rations on blood and biochemical blood parameters and nutrient digestibility of fishmeal rations on rhesus monkeys was studied. And also calculated the economic efficiency of the use of fish meal in the structure of ration. On the basis of experimental data, it was established that the introduction of fish meal into the diet provides an improvement in the process of assimilation of feed, which has a beneficial effect on hematological and biochemical blood parameters in experimental primates. And provides a reduction in the cost of full granular feed.
Influence of chlorella on hematological parameters and metabolism of rhesus monkeys
Authors: Gaponov N.V. , Neverova O.P. , Gorelik O.V. , Kharlap S.Y. , Bezhinar T.I.
Published: June 2020

In our experiment, we studied the possibility of including dry chlorella in primate feeding structures of the diet. In order to replace high-nutritional protein feed of plant and animal origin. Along with dry chlorella, the effect of chlorella suspension, as a dietary supplement, on the primate organism has been studied. For experiments with dry chlorella, the primate feeding ration was changed. In the structure of the diet of dry chlorella feeding was subjected to substitution: dry milk by 90%, egg powder by 9%. Whereas chlorella emulsion with a cell density in the culture fluid of 55-60 million / cm3 rhesus monkeys was obtained with drinking water. At the rate of 2.8 ml / kg body weight per day and complete feed (CF), as in the control group. The data obtained macaca mulatta of the experiment indicate that the inclusion of chlorella in the structure of rations of primates, both dry and with culture liquid, contributes to a better digestibility of feed nutrients. Significantly increases the level of metabolism in the body of primates of the experimental groups. And the results of hematological studies indicate an increase in the natural resistance of the organism.
Production of hornless dairy cattle from genome-edited blastocysts
Authors: Deykin Alexey V. , Bruter Alexandra V. , Krivonogova Anna S. , Shepelev Mikhail V. , Koshchaev Andrey G.
Published: June 2020

Cattle of polled phenotype is convenient for breeders, as it decreases the risk of animals being hurt and ensures safety of workers. We developed the system for editing cattle genome using CRISPR/Cas9 which will allow production of animals with polled phenotype genetically based on any cattle breed without changing its main phenotypic traits.
Incubation qualities of the eggs of the laying hens of the parent herd when using probiotics in the diet
Authors: Ovchinnikov Alexander , Ovchinnikov Lyudmila , Matrosov Yulia , Bryukhanov Dmitry , Belookov Alexei
Published: June 2020

Occasional use of the probiotics Levisel SB Plus and Tsellobacterin – T in a dose 0.50 kg/t of the mixed fodder in a diet of the laying hens at the age 21-26, 34-39 и 45-48 weeks has increased metabolic processes in the body of a bird and productivity of the laying hens in a group with Levisel SB Plus by 10.6 %, with a dash Tsellobacterin – T – by 16.1 %, but it did not affect the weight of the egg during all periods of the productive cycle. The egg incubation results showed that probiotice Levisel SB Plus increased egg hatability by 4.1%, Tsellobacterin-T by 6.2%, their fertilization by 2.1 and 4.2%, the withdrawal of young chickens by 3.5% and 5.1%. The addition of probiotics did not change the hatchability of eggs (93.22 and 93.17%) in these groups, but reduced the amount of unfertilized eggs by 1.8 and 10.3%. There was a higher content of carotenoids and vitamin A in the eggs of the laying hens and in the body of daily chickens. Using the probiotics in the diet of laying hens of the parent herd has reduced the cost of feeding for 10 eggs by 8.2-8.5% , with a dash of Levisel SB Plus by 15,0-15,4%, with a dash of Tsellobacterin – T to the weight of the egg by 1,8-9,7% and 15.3-15.5% respectively. At the same time, the payment of food products increased in the group using Levisel SB Plus by 10.3-10.7%, with Tsellobacterine - T by 20.9- 21.7%, the profitability of production increased by 13.1 and 22.3%.
Creating a functional basis for the production of food emulsions
Authors: Feofilaktova Olga , Grashchenkov Dmitrij , Karkh Dmitrij , Lukinykh Mikhail
Published: June 2020

Occurence dependence of a number of diseases on the breakdown of the population nutrition structure has been established for a long time. Epidemiological and clinical evidence supports the role of functional food ingredients in the pathogenesis of various diseases. The omega-3, -6, -7 and -9 fatty acids play a special role among them. Having a number of functional properties, they contribute to the prevention of a number of common diseases, especially cardiovascular diseases. These mono- and polyunsaturated fatty acids are among the most common vegetable oils. This article describes the technology of developing a functional fat base for emulsion food production based on a combination of several types of vegetable oils. The technology uses a specially designed computer program that allows to compose a combination of vegetable oils based on the optimal ratio of omega-3 and omega-6 fatty acids, as well as with taking into account the physiological standards of consumption of mono- and polyunsaturated fatty acids.
Studying the processes of lipid peroxidal oxidation in the organism of fresh cows under the antioxidant impact
Authors: Kashirina Lidiya , Ivanischev Konstantin , Romanov Kirill
Published: June 2020

The article contains information on the state of the processes of lipid peroxidation (LPO) in fresh cows under the influence of stress reaction caused by labor and the beginning of the lactation period. To reduce oxidative stress in the body of fresh cows, antioxidants were used in the form of preparations “E-selenium” and “Butofan”. The aim of the research was to determine the effect of vitamin-containing preparations “E-selenium” and “Butofan” on the productivity of fresh cows, the quality of milk and butter, made from it. The studies were carried out during the winter-stall period on one of the farms of Ryazan district of Ryazan region and involved 12 fresh black-and-white cows aged 4 years. The control group of animals was intact. As a result of the investigations, it was found that due to the action of the above preparations, which have antioxidant properties, the productivity parameters in the experimental groups of animals were higher compared to the control group, because they had an inhibiting effect on lipid peroxidation processes in the organism and activated the work of its own antioxidant system.
Enzootic bovine leucosis in cows on farms in Almaty and Turkestan regions of Kazakhstan
Authors: Ibazhanova Assem , Namet Ajdar , Nurgazy Banu , Kenzhebekova Zhuldyzaj , Shmanov Gabdolla
Published: June 2020

The objective of this study was to evaluate pathomorphological and histopathological characteristics of internal organ tissues and skeletal muscles of Black-Motley cows with bovine laeukemia necropsied between 2013 and 2017. Pathomorphological and histopathological assessment of enzootic bovine leukosis was performed. The viral presence was proved by haematological study, enzyme-linked immunosorbent assay and agar-gel immunodiffusion. There was the pathomorphological manifestation of an immunosuppressive condition in the cattle, as well as leukemic cell accumulations in the brain, kidneys, duodenum, spleen, lymph nodes, cardiac and skeletal muscles. Our study is considered to bear significance concerning the description of microstructural changes involving lymph node trabeculae and myocardial fibres from leukemic cows. This investigation, therefore, provides new knowledge on histopathological features of enzootic bovine leucosis, which potentially may bring new insights into the disease mechanisms.
Efficiency of growing crossbreed bull-calves of the mountain cattle with Russian polled breed
Authors: Simonov G.A. , Zoteev V.S. , Sadykov M.M. , Aligazieva P.A. , Alikhanov M.P.
Published: June 2020

The article presents the results of cross-breeding of mountain cattle with Russian polled breed. The growth and development of the crossbreed and purebred bull-calves of these breeds in the mountainous province of Dagestan have been studied in a comparative aspect. Efficiency of highland pastures use by crossbreed animals in comparison with pure-bred mountain peers has been established. The young cattle was grown according to the technology of meat cattle breeding “cow — calf”. In ablactation, the crossbred bull-calves had a living weight of 191.3 kg versus 159.3 kg in peers of mountain cattle. This figure was higher by 32.0 kg or 20.1% compared to purebred bull-calves of mountain cattle. At 12 months of age, the crossbred animals were also superior in living weight in comparison of young mountain cattle by 40.1 kg or 18.4%. According to this indicator, the advantage in crossbred animals at 15 months of age remained. The live mass of crossbred bull-calves at 18 months of age equaled to 399.5 kg against 332.6 kg of purebred mountain peers, the difference in favor of the former was 66.9 kg or 20.1%. Average daily growth of crossbreed bull-calves during the growing period was 122 grams or 20.8% higher. Young crossbred cattle had a clear advantage in terms of physique. Heavy carcasses with high slaughter yield were obtained from it. The conducted studies indicate the effectiveness of cross-breeding of mountain cattle with Russian polled breed in the mountainous province of Dagestan.
Seed germination of native plants in soil transformed by invasive plantsAcer negundoandHeracleum sosnowskyi
Authors: Rafikova Olesya , Kiseleva Olga , Veselkin Denis
Published: June 2020

We tested the hypothesis of the effect of soils transformed by invasive plants (Acer negundoL. andHeracleum sosnowskyiManden.) on native plants germination. We conducted vegetation experiments in germination ofFestuca rubraL. andTrifolium repensL. in upper layer of urban soil collected in invasive plants thickets and in nearby areas without invasive plants in 2016–2017. We also used the sod-podzolic soil from old suburban meadow as a control. Differences in seed germination on soils transformed by invasive plants and non-transformed soils were insignificant. We could not confirm the effect of soils collected fromAcer negundoandHeracleum sosnowskyithickets on plants germination by GLM analysis.
Potato Cooperation: Lessons of the History for Modern Development
Authors: Osipov Vladimir , Evseev Vadim , Skryl Tatiana
Published: June 2020

The article offers a discussion about finding solutions to uneven market power of potato producers and its processors. The high market power of persons not directly related to potato production has a direct impact on the income level of those who produce the product. The obvious injustice of this situation is not the know-how of the current stage of development of economic relations in Russia, but a well-forgotten old, unresolved issue from the past. This situation, when the manufacturer of the product found himself in a deliberately subordinate position with respect to the buyer, wholesale processor, breeder, is completely new. And the solution that previously yielded a positive result cannot be called new - this is production cooperation. There are institutional conditions for its implementation, and it seems that economic conditions have matured to strengthen agricultural producers. The aim of the paper is to compare the market power of the before Revolution situation in agriculture and post-Soviet situation of modern agroeconomic development. Results. The compare of the market power shows that in the market economy there is almost unaltered structure of the food market and unbalanced power distribution with tilt for the seller but not producer. Methods. There were methods of institutional analysis, historical, normative, comparative and some others used in frame of research. Results. Market power of sellers in the past and modern time plays negative role on reproduction process. As it is shown on potato production, only cooperatives can solve the problem of unbalanced market power distribution and will make producers more competitive in reproduction process. The methodology of institutional analysis and specially historical institutionalism help us to understand the market power distribution mechanism in reproduction process. It makes our research useful for agrarian policy makers on all levels of power.
Experimental studies results of electromagnetic field effect of dielcometer system to increase the yield of greenhouse crops
Authors: Singatulin Roman S. , Sapryka Alexandr V.
Published: June 2020

The article presents experimental studies of the application of electromagnetic technologies for impact on biological objects. Tomato seeds were chosen as experimental biological objects. For the study, the technological parameters of EMF were obtained using the method of full factor experiment. Laboratory and field studies were carried out. In laboratory studies, the results of EMF effects on chromosomal aberrations of tomato seeds were obtained. Dependencies of chromosomal aberrations in tomato seeds on changes in seeds EMF exposure, EMF frequency, and EMF power flow density were given. In field studies, pre-sowing treatment of tomato seeds with electromagnetic radiation was performed in order to cause changes in biochemical processes in the plant. During the experiment, 55 options of pre-sowing EMF treatment with specified parameters were obtained. Dependencies of tomato seed germination on input parameters - EMF frequency, power flow density and exposure were given. After laboratory and field tests, it was concluded that pre-sowing EMF treatment of tomato seeds with optimal parameters results in an increase in chromosomal aberrations of tomatoes by 5.5%; field germination of tomatoes by 18%.
Variation of rice varieties of Russian breeding by grain quality traits in growing conditions of agrolandscape zones of Krasnodar region
Authors: Tumanian Natalia , Chizhikova Svetlana , Papulova Elina , Kumeiko Tatyana , Garkusha Sergey
Published: June 2020

The technological grain quality traits of varieties of the Federal Scientific Rice Centre (Rapan., Rapan 2, Favorit, Nautilus, Yakhont, Olimp, Patriot) grown in the old-delta and valley agrolandscape zones of Krasnodar region (Russia) in 2017–2019 were studied. The studied rice varieties are included in the State register of breeding achievements approved for use in the North Caucasus region in 2014-2019, Rapan 2 is under state variety testing. Most of the varieties under study showed the highest values of grain quality traits in the valley agrolandscape in 2019, in the old-delta - in 2018, which indicates the reaction of the varieties to agroclimatic conditions of vegetation. The best varieties for grain quality on the basis of low variability in the aggregate of all quality traits were recognized as Favorit for the valley agrolandscape zone of Krasnodar region (predecessor – fallow field), and Rapan 2 for the old delta agrolandscape zone (predecessor - winter wheat). According to the absolute values of the traits characterizing the yield and milled rice quality, the best variety in the valley agrolandscape was Yakhont, and in the old-delta, Nautilus. The placement of rice varieties in agrolandscape zones of Krasnodar region is recommended taking into account their reaction to agroclimatic conditions of cultivation.
Assessment of water resources of the Asa river basin in Southern of Kazakhstan under conditions of climate change
Authors: Nabiollina Madina , Zhaparkulova Yermekkul , Sherov Anvar
Published: June 2020

In the Address to the people of Kazakhstan dated January 30, 2017, the President of the Republic of Kazakhstan emphasized the need for technological modernization of economic sectors. In connection with this task, the Government of the Republic adopted the State Program for the Development of the Agro-Industrial Complex of the Republic of Kazakhstan for 2017-2021, aimed at solving urgent problems of the water sector of the economy [1]. The reason for climate change is the dynamic processes on Earth, external influences, such as fluctuations in the intensity of solar radiation, and, more recently, human activities. The article presents a study assessing the water resources of the Asa River. Water intake and water supply, formation and occurrence of groundwater level, condition of collector-drainage water, mineralization. The article given methods and solutions for the disposal of water resources.
Industry aspects of farm access to high value-added supply chains
Authors: Kudryavtsev Aleksandr , Karmyshova Yuliya
Published: June 2020

This paper examines the factors characterizing the access of farms to the supply chains of agricultural products with high added value. Indicators of statistical reporting on farm activity grouped by type of products are analyzed, on the basis of which the influence of production size on opportunities selling products at a higher price is assessed. It is concluded that for various sectors of agriculture the level of product sale prices’ dispersion by individual farmers differs, which characterizes differences and opportunities of farmers to increase own share in the added value creation chain. Identified types of agricultural products, producers of which must increase production volumes to gain access to more profitable trade channels of products, as well as types of products where significant production volume is not a prerequisite for higher sales prices. These conclusions can be taken into account in assessing the feasibility of establishing marketing or processing consumer cooperatives of farmers.
Obstacles to the development of the agricultural sector of economics and ways to overcome them
Authors: Kuznetsova Alfiya , Askarov Almir , Svetlakov Andrei
Published: June 2020

The article discusses the factors and problems that have a negative impact on the indicators of economic efficiency of the industry and, thus, hinder the sustainable development of rural areas, and also suggests a number of measures to overcome them. The methods of statistical data analysis and the method of aligning time series are used in the work. Large-scale production, on the one hand, entails an increase in labor productivity, and, on the other hand, generates rural unemployment. It was revealed that high-tech methods of agricultural production lead to an increase in the cost of manufactured products, both in a steady increase in prices for energy resources and concentrated feed, which increases the level of risks in the agricultural business. In addition, non-observance of the norms of crop rotation of sunflower crops on the same land plots entails damage to soil fertility. Such a strategic planning system is needed as part of the legal framework of public administration, which would create the conditions for the formation of healthy competition of manufactured products not only domestically, but also on the world market.
The role of agricultural economists in study on problems related to regional food safety
Authors: Fedorova Ekaterina , Darbasov Vasily , Okhlopkov Mikhai
Published: June 2020

The beginning of the agricultural and economic science foundaton in historical aspect is studied in the article. The stages of its formation and development in the Republic of Sakha (Yakutiya) are reviewed. The paper presents some well-known scientists-agricultural economists who have made a significant contribution to the science and education of the Republic. A brief overview of their researches is shown. The article focuses on the need for enhanced capacity-building for the activity of regional economic research. Particularly, it is necessary to significantly enhance the intellectual potential of scientists in terms of selecting and evaluating priority areas of social and economic researches on the AIC development, including food safety governance. The study highlights that agricultural science plays an important role in solving the main tasks of providing food safety. The authors concluded that it is necessary to sustain regional science aimed at creating a local food base in the Far North.
Reasonability of development of agro-insurance in Russian Federation on the basis of mutual insurance
Authors: Logvinova Irina , Rubin Yury
Published: June 2020

Article deals with the justification of reasonability of agro insurance risk-management development in Russian Federation on the basis of mutual insurance. Nowadays this kind of insurance is carried out only by the commercial insurers, and thus are created conditions for the non-rational usage both private and government finance directing for the insurance premium. At the same time there is a successful practice of some developed countries and also Russian historical experience of mutual insurance of agricultural risks. The authors suggest to develop mutual insurance societies of agricultural risks not excepting the possibility of insurance of such kind of risks by the commercial insurers. It is pointed out that in RF mutual insurance societies for successful development will need the support of the state in the form of organizational and fiscal facilities. Development of mutual insurance societies of agricultural risks will prevent transformation of the part of the finance into the dividend for the owners of the insurance companies, and also activates the competition in the sector of agro insurance.
Globalization of the transport system of the agro-industrial complex in the conditions of modern society
Authors: Ananyev M.A. , Bakaeva Zh.Yu , Matveeva O.L. , Steklova I.V. , Shchegoleva E.N.
Published: June 2020

The article deals with the problem of transportation of agricultural products. The main causes of problems in this area are identified. The mechanism of creating favorable conditions in the system of globalization relations of the modern economy is analyzed. The fundamental elements in the transport system are competition orientation and information ownership over a certain period of time. Globalization involves the integration of different types of transport systems at the sectoral characteristics. The purpose of the research is to study the essence, meaning and prospects of the concept of “economic transport space in the national food supply system" in the processes of food market globalization. The main indicators of the “economic space" are: first, to determine the parameters that characterize the economic transport space, and secondly, to determine the prospects for using its structural elements in the system of transport supply relations, depending on the temporal and spatial components in the modern sector of the economy to provide food for the needs of society.
Readiness of agricultural workers to develop new competencies and change the employment model in the conditions of digitalization
Authors: Zabelina Olga V. , Mirzabalaeva Farida I. , Sankova Larisa V.
Published: June 2020

The relevance of the research is caused by the expansion of agrarian employment digital transformation. The purpose of the article is to study the readiness of agricultural workers to the digital challenges of modern times and the new model of employment. The article analyzes the expectations of agricultural workers regarding the risks of digitalization, changes in the form of employment and labor functions, change of occupation and place of residence. The critical role of the human factor in the transition to a new employment model caused by digitalization is taken as a hypothesis of the study. Underestimation of labor settings of employees lead to slowing development of agro-industrial complex. The hypothesis was tested when surveying agrarian workers. According to the survey, the level of readiness to change the employment model is more likely to be average. The most “problematic” component was readiness to learn, get a new profession. In order to increase the propensity of agricultural workers to digital employment, it is necessary to improve the system of labor management and economic incentives to develop digital competencies. The results can be used to assess the readiness and opportunity of agricultural workers to work in new conditions, manage changes in employment in the agricultural sector of the Russian economy.
To the problem of legal regulation of agricultural land turnover in the Russian Federation
Authors: Chupina Irina P. , Simachkova Natalia N. , Trotsenko Oksana S.
Published: June 2020

The authors comprehensively investigated theoretical and practical problems of legal regulation of agricultural land turnover in the Russian Federation. They analyzed the jurisprudence in the field of agricultural land turnover, examined the legal regime of agricultural land in the Russian Federation, investigated the peculiarities of land plots turnover from agricultural lands, identified a number of significant problems in the legislation in the field of legal regulation of agricultural purposes land turnover. It is difficult to overestimate the importance of land, which is a nonrecoverable natural resource. From this point of view, agricultural land has a unique unrepeatable natural fertility capacity that determines the possibility of producing life support products, being an essential component of the environmental system. In the annual Address to the Federal Assembly of the President of Russia in 2019, V.V. Putin, specifying the main directions of strategic development of the country, noted the high importance of the land legislation development. The peculiarities of the agricultural land plots turnover are due to the public nature of land relations regulation. For this category of land, a special legal regime is established for food security purposes of Russia, which leads to the prevention of removing these lands from agricultural circulation, as well as building development. According to articles 9, 36 of the Constitution of the Russian Federation, “land and other natural resources are used and protected in the Russian Federation as the basis for the lives and activities of peoples living on the the relevant territory” and the exercise of authority by land owners is limited to conditions for potentially damaging the environment and violation of rights and legitimate interests of other persons.
Universal consistency of the k-NN rule in metric spaces and Nagata dimension
Authors: Collins Benoît , Kumari Sushma , Pestov Vladimir G.
Published: June 2020

The k nearest neighbour learning rule (under the uniform distance tie breaking) is universally consistent in every metric space X that is sigma-finite dimensional in the sense of Nagata. This was pointed out by Cérou and Guyader (2006) as a consequence of the main result by those authors, combined with a theorem in real analysis sketched by D. Preiss (1971) (and elaborated in detail by Assouad and Quentin de Gromard (2006)). We show that it is possible to give a direct proof along the same lines as the original theorem of Charles J. Stone (1977) about the universal consistency of the k-NN classifier in the finite dimensional Euclidean space. The generalization is non-trivial because of the distance ties being more prevalent in the non-Euclidean setting, and on the way we investigate the relevant geometric properties of the metrics and the limitations of the Stone argument, by constructing various examples.
Set estimation under biconvexity restrictions
Authors: Cholaquidis Alejandro , Cuevas Antonio
Published: June 2020

A set in the Euclidean plane is said to be biconvex if, for some angle θ ∈ [0, π∕2), all its sections along straight lines with inclination angles θ and θ + π∕2 are convex sets (i.e., empty sets or segments). Biconvexity is a natural notion with some useful applications in optimization theory. It has also be independently used, under the name of “rectilinear convexity”, in computational geometry. We are concerned here with the problem of asymptotically reconstructing (or estimating) a biconvex set S from a random sample of points drawn on S. By analogy with the classical convex case, one would like to define the “biconvex hull” of the sample points as a natural estimator for S. However, as previously pointed out by several authors, the notion of “hull” for a given set A (understood as the “minimal” set including A and having the required property) has no obvious, useful translation to the biconvex case. This is in sharp contrast with the well-known elementary definition of convex hull. Thus, we have selected the most commonly accepted notion of “biconvex hull” (often called “rectilinear convex hull”): we first provide additional motivations for this definition, proving some useful relations with other convexity-related notions. Then, we prove some results concerning the consistent approximation of a biconvex set S and the corresponding biconvex hull. An analogous result is also provided for the boundaries. A method to approximate, from a sample of points on S, the biconvexity angle θ is also given.
Optical instrumentation for chromospheric monitoring during solar cycle 25 at Paris and Côte d’Azur observatories
Authors: Malherbe Jean-Marie , Corbard Thierry , Dalmasse Kevin
Published: June 2020

We present the observing program proposed by Paris and Côte d’Azur Observatories for monitoring solar activity during the upcoming cycle 25 and providing near real time images and movies of the chromosphere for space-weather research and applications. Two optical instruments are fully dedicated to this task and we summarize their capabilities. Short-term and fast-cadence observations of the chromosphere will be performed automatically at Calern observatory (Côte d’Azur), where dynamic events, as flare development, Moreton waves, filament instabilities and Coronal Mass Ejections onset, will be tracked. This new set of telescopes will operate in 2021 with narrow bandpass filters selecting Hα and CaII K lines. We present the instrumental design and a simulation of future images. At Meudon, the Spectroheliograph is well adapted to the long-term and low-cadence survey of chromospheric activity by recently improved and optimized spectroscopic means. Surface scans deliver daily (x, y, λ) datacubes of Hα, CaII K and CaII H line profiles. We describe the nature of available data and emphasize the new calibration method of spectra.
Spin from defects in two-dimensional quantum field theory
Authors: Novak Sebastian , Runkel Ingo
Published: June 2020

We build two-dimensional quantum field theories on spin surfaces starting from theories on oriented surfaces with networks of topological defect lines and junctions. The construction uses a combinatorial description of the spin structure in terms of a triangulation equipped with extra data. The amplitude for the spin surfaces is defined to be the amplitude for the underlying oriented surface equipped with a defect network dual to the triangulation. Independence of the triangulation and of the other choices follows if the line defect and junctions are obtained from a Δ-separable Frobenius algebra with involutive Nakayama automorphism in the monoidal category of topological defects. For rational conformal field theory, we can give a more explicit description of the defect category, and we work out two examples related to free fermions in detail: the Ising model and the so(n) WZW model at level 1.
Quantum Bernoulli noises approach to Stochastic Schrödinger equation of exclusion type
Authors: Ren Suling , Wang Caishi , Tang Yuling
Published: June 2020

Stochastic Schrödinger equations are a special type of stochastic evolution equations in complex Hilbert spaces, which arise in the study of open quantum systems. Quantum Bernoulli noises refer to annihilation and creation operators acting on Bernoulli functionals, which satisfy a canonical anti-commutation relation in equal time. In this paper, we investigate a linear stochastic Schrödinger equation of exclusion type in terms of quantum Bernoulli noises. Among others, we prove the well-posedness of the equation, illustrate the results with examples, and discuss the consequences. Our main work extends that of Chen and Wang [J. Math. Phys. 58(5), 053510 (2017)].
Quantitative non-destructive single-frequency thermal-wave-radar imaging of case depths in hardened steels
Authors: Wei Y. , Melnikov A. , Wang M. , Mandelis A.
Published: June 2020

Single-frequency thermal-wave radar (SF-TWR) imaging was used to produce dynamic images of effective case depths from phase image frequency scans in AISI 9310 and Pyrowear 53 steels. SF-TWR, as a fast non-destructive testing technique, was also compared with conventional photothermal radiometry measurements in these two types of steel samples using a three-layer theoretical thermal-wave model. In this paper, a novel approach of SF-TWR imaging, combining a three-distinct-layer thermal-wave model and radial phase profiles to image mean value case depths and their lateral non-uniform distributions, yielded quantitative images of case depths in the two hardened steels and exhibited very good correlation with standard Vickers measurements. The SF-TWR images further revealed strong inhomogeneities in the case depth thickness profiles to be used as important feedback to the heat treating manufacturing industry toward the optimization of their case depth hardening process.
Resistance drift in Ge2Sb2Te5 phase change memory line cells at low temperatures and its response to photoexcitation
Authors: Khan R. S. , Dirisaglik F. , Gokirmak A. , Silva H.
Published: June 2020

Resistance drift in amorphous Ge2Sb2Te5 is experimentally characterized in melt-quenched line cells in the range of 300 K to 125 K and is observed to follow the previously reported power-law behavior with drift coefficients in the range of 0.07 to 0.11 in the dark, linearly decreasing with 1/kT. While these drift coefficients measured in the dark are similar to commonly observed drift coefficients (∼0.1) at and above room temperature, measurements under light show a significantly lower drift coefficient (0.05 under illumination vs 0.09 in the dark at 150 K). Periodic on/off switching of light shows a sudden decrease/increase in resistance, attributed to photo-excited carriers, followed by a very slow response (∼30 min at 150 K) attributed to contribution of electron traps and slow trap-to-trap charge exchanges. A device-level electronic model is used to relate these experimental findings to gradual charging of electron traps in amorphous Ge2Sb2Te5, which gives rise to growth of a potential barrier for holes in time and, hence, resistance drift.
A class of Langevin equations with Markov switching involving strong damping and fast switching
Authors: Nguyen Nhu N. , Yin George
Published: June 2020

This work is devoted to a class of Langevin equations involving strong damping and fast Markov switching. Modeling using continuous dynamics and discrete events together with their interactions much enlarged the applicability of Langevin equations in a random environment. Strong damping and fast switching are characterized by the use of multiple small parameters, resulting in singularly perturbed systems. The motivation of our work stems from the reduction of complexity for complex systems. Under suitable conditions, it is established that the solutions of the Langevin equations satisfy a large deviations principle. Then, we apply our results to statistical physics problems of a small particle in time-inhomogeneous environment and low temperature. Some connections to other fields in physics are also given.
Technique offers improved resolution and characterization of perovskite-based photovoltaics
Authors: Lim Alane
Published: June 2020

Researchers have developed a method for directly measuring the electronic transport at interfaces within a perovskite-based solar cell.
All-organic flexible logical computing system based on electrical polarization of ferroelectric polymers
Authors: Liu Jia-Hao , Chen Xin , Ren Yao , Shen Qun-Dong
Published: June 2020

Artificial intelligence refers to the ability of a machine to study and think like a human. In the human brain, these functions rely on changes and transmission of electrical polarization among neurons. Ferroelectric polymer membranes exhibit electrical polarization that is tunable under the action of external stimuli, such as mechanical stresses and electric fields, and they, thus, exhibit signal transmission characteristics similar to those of neurons. In this paper, we describe the fabrication of a flexible computing device based on ferroelectric polymers that are capable of performing Boolean logic operations and have data retention capabilities and high state discrimination down to the nanoscale, thereby enabling dense packaging and low-power logic state switching. It is also able to adhere to human skin. This demonstration of a logical computing system based on polarization will help in the further exploration and development of artificial intelligence.
Spiking dynamic behaviors of NbO2 memristive neurons: A model study
Authors: Bo Yeheng , Zhang Peng , Zhang Yiwen , Song Juan , Li Shuai , Liu Xinjun
Published: June 2020

Neuromorphic computing based on spikes has broad prospects in energy-efficient computation. Memristive neuron in this study is composed of two volatile memristors that have been shown to exhibit rich biological neuronal dynamics. Here, we show spiking dynamic behaviors of NbO2 memristive neurons by a detailed simulation study. With a DC input voltage, the operation windows of both periodic oscillation and neuron-like action potential spikes are recognized in the resistance–voltage phase diagrams of NbO2 memristive neurons. With a voltage pulse as the input, the periodic oscillation region can be classified into three subregions including the spike-OFF, spike-ON, and meta-spike transition regions. When the memristive neuron operates in the meta-spike transition region, it can regulate the “ON” and “OFF” states of the oscillation circuit by changing the ending time of the input pulse. It implies that both the input signal and the output signal determine the state of the circuit. The demonstration of a phase matching method provides a useful way for controlling “ON” and “OFF” states of the periodic oscillation behavior of the memristive neuron. Moreover, the effect of the circuit parameters on the peak-to-valley amplitude of the output spikes with action potential is investigated. A stable and controllable waveform output can be regulated by changing the capacitance, incorporating a series resistor, and customizing the active memristor. All these results provide a reliable reference for implementing memristive neurons in neuromorphic computing.
Carbon related hillock formation and its impact on the optoelectronic properties of GaN/AlGaN heterostructures grown on Si(111)
Authors: Tetzner H. , Sana P. , Klesse W. M. , Capellini G. , Schubert M. A. , Thapa S. B. , Storck P. , Schroeder T. , Zoellner M. H.
Published: June 2020

The integration of GaN on Si as large scale substrates still faces many hurdles. Besides the large difference in the lattice constant and the high thermal mismatch existing between GaN and Si, spiral hillock growth phenomena are common problems in the development of thick GaN layers. In this work, hexagonal hillocks were observed on GaN/AlGaN high-electron-mobility transistor heterostructures grown on Si(111) by metal-organic chemical vapor deposition. The presence of these morphological and structural defects is attributed to the presence of localized contamination at the AlN/Si interface. These carbon-based defects cause highly defective regions in the AlN seed layer, which propagate through all the AlGaN buffer layers inducing the formation of V-shaped pits at the AlGaN interfaces. In hillock regions of the wafers, Raman spectroscopy indicates disturbed two-dimensional electron gas characteristics resulting from GaN/AlGaN interface roughness and a decreased amount of free carriers in the potential well. Energy-dispersive x-ray spectroscopy reveals Ga accumulation inside the V-pits and in nanopipes below, which is responsible for defective areas and the increased GaN growth rate resulting in hillock formation. Photoluminescence measurements confirm the presence of Ga-rich material reducing the inherent gallium vacancy concentration. Here, the reduced amount of Ga-vacancies acting as a shallow acceptor suppresses the ultraviolet luminescence band from donor–acceptor pair transition.
The free energy of the two-dimensional dilute Bose gas. II. Upper bound
Authors: Mayer Simon , Seiringer Robert
Published: June 2020

We prove an upper bound on the free energy of a two-dimensional homogeneous Bose gas in the thermodynamic limit. We show that for a2ρ ≪ 1 and βρ ≳ 1, the free energy per unit volume differs from the one of the non-interacting system by at most 4πρ2|lna2ρ|−1(2−[1−βc/β]+2) to leading order, where a is the scattering length of the two-body interaction potential, ρ is the density, β is the inverse temperature, and βc is the inverse Berezinskii–Kosterlitz–Thouless critical temperature for superfluidity. In combination with the corresponding matching lower bound proved by Deuchert et al. [Forum Math. Sigma 8, e20 (2020)], this shows equality in the asymptotic expansion.
Experimental study of speckle patterns generated by low-coherence semiconductor laser light
Authors: Halpaap D. , Marconi M. , Hernandez R. , Yacomotti A. M. , Tiana-Alsina J. , Masoller C.
Published: June 2020

Speckle is a wave interference phenomenon that has been studied in various fields, including optics, hydrodynamics, and acoustics. Speckle patterns contain spectral information of the interfering waves and of the scattering medium that generates the pattern. Here, we study experimentally the speckle patterns generated by the light emitted by two types of semiconductor lasers: conventional laser diodes, where we induce low-coherence emission by optical feedback or by pump current modulation, and coupled nanolasers. In both cases, we analyze the intensity statistics of the respective speckle patterns to inspect the degree of coherence of the light. We show that the speckle analysis provides a non-spectral way to assess the coherence of semiconductor laser light.
Effect of chemical reactions on electrohydrodynamic force generation process in dielectric barrier discharge
Authors: Nakai K. , Komuro A. , Nishida H.
Published: June 2020

A discharge plasma simulation based on a three-fluid model is generally utilized to understand the physical mechanism in a dielectric barrier discharge (DBD) plasma actuator. In this study, the influence of chemical reactions considered in a numerical model on the simulation results is investigated from the viewpoint of electrohydrodynamic (EHD) force generation in the DBD plasma actuator. Positive and negative streamers are simulated utilizing three types of models considering different reactions and species, and the investigation is conducted in two steps. In the first step, where the influence of the neutralization process is investigated, the electron recombination with a cluster ion (O4+) plays an important role; it contributes to the decrease in seed electron production and effective coefficient of ionization for the positive streamer, and the decrease in negative ion production for the negative streamer; as a result, the propagation length and EHD force generation decrease. In the second step, where the influence of the production process is investigated, the stepwise ionization from metastable states has little influence owing to quite low production rates. Therefore, the simulation results indicate that the numerical model needs to consider the electron recombination with O4+ to accurately predict the streamer propagation and EHD force generation, while it is unnecessary to take into account the metastable molecules.