350 research outputs found

    Three-Phase Freak Waves

    Full text link
    In the article, we describe three-phase finite-gap solutions of the focusing nonlinear Schr\"odinger equation and Kadomtsev-Petviashvili and Hirota equations that exhibit the behavior of almost-periodic "freak waves". We also study the dependency of the solution parameters on the spectral curves

    Resistance of modern spring barley cultivars to harmful organisms

    Get PDF
    Background. Diseases and pests cause great damage to barley stands and harvests. Harvest losses from harmful organisms reach 25–30%.Materials and methods. During 2017–2020, 46 spring barley cultivars from the VIR collection, listed in the State Register for Selection Achievements, were studied for their resistance to fritfly, net and spot blotches, brown rust, and powdery mildew. The tests were carried out in the field with provocative colonization by fritfly and under natural infection pressure of leaf pathogens.Results and conclusions. In 2017, net blotch predominated over other diseases. In 2018, there was an epyphytotic outburst of spot blotch, and cultivars with weak development of this disease were identified. In 2019 and 2020, the incidence of brown rust and powdery mildew was significant, and the virulence of fritfly increased greatly in the same years. Field tests resulted in identification of 3 barley accessions resistant to fritfly: ‘Odon’ (k-31118, Buryatia), ‘Miar’ (k-31203, Orenburg Province), and ‘Omsky 99’ (k-31230, Omsk Province). Cv. ‘Posada’ (k-31245, Germany) was weakly affected by fritfly, brown rust and powdery mildew. Cultivars were selected for their low susceptibility to powdery mildew (up to 5%): ‘Chiraz’ (k-31131, Denmark), ‘Cheerio’ (k-31297, Denmark), and ‘Odyssey’ (k-31333, England), and brown rust: ‘Chiraz’ (k-31131, Denmark), ‘Eifel’ (k-31249, France), ‘Ursa’ (k-31339), and ‘Sunshine’ (k-31129, Germany). Such long-term assessment results can be used in breeding programs to develop cultivars with group or complex resistance to harmful organisms

    Directions to improve economic efficiency of regional production

    Get PDF
    The paper provides theoretical grounding and the directions for improving the economic efficiency of the regional feedstuff production. The study develops a conceptual model of distributing management functions of feedstuff production between the regional authorities of state sectoral and economic management and the district level. The authors suggest the methodology for calculating potential capacity of intraregional feedstuff market, considering the demands of all categories of agricultural manufacturers. The study examines possibilities for implementing the strategy of diversified growth and development of the intraregional feedstuff market, including the terms of interaction between the large and micro-business inside the industry and cooperation of micro-business feedstuff manufacturers with agricultural production. The authors have developed the methodology for assessing the efficiency of feedstuff production, based on the aggregate estimation of the management organization, conditions for the development of feedstuff production and changes in the feedstuff production and livestock breeding industry.peer-reviewe

    Strawberry resistance to the major fungal phytopathogens: R-genes and their DNA markers

    Get PDF
    The garden strawberry Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier (1785) is a perennial herbaceous plant of the Rosaceae family; it is cultivated all around the world. It accounts for more than half of the global volume of berries production. In Russia, more than 160 tons of garden strawberries are grown annually, but according to Russian scientists, this crop has a much higher productivity potential. Various pathogens, including bacterial, viral and fungal infections, negatively affect the productivity of strawberry. Anthracnose (caused by Colletotrichum Corda.), crown rot (Phytophthora cactorum Lebert & Cohn), red core disease (Phytophthora fragariae var. fragariae Hickman), fusarium wilt (Fusarium oxysporum f. sр. fragariae Winks & Williams ) and strawberry powdery mildew (Podosphaera aphanis [Sphaerotheca macularis] (Wallr.) U. Braun & S. Takam) are among the most important fungal diseases of strawberry. This review discusses the current data about the known genes and quantitative trait loci (QTLs) associated with resistance to listed plant pathogens. The review also offers information about molecular markers of different types: SDRF, AFLP, SSR, SCAR, SNP, associated with these genes/QTLs and used in the molecular screening of strawberry collections for practical purposes

    Preparation of Class Y Immunoglobulins that Neutralize the Marburg Virus

    Get PDF
    The aim was to study the possibility of inducing Marburg-neutralizing chicken antibodies (MARV) using various immunogens.Materials and methods. Recombinant vaccinia virus expressing the surface glycoprotein (GP) transgene MARV of Musoke strain and pseudovirus particles exhibiting GP of three strains of MARV – Popp, Musoke and DRC2000 based on lentivirus and recombinant strain of vesicular stomatitis virus (VSV) were used as immunogens. Two groups of birds were involved in the study. Chickens were immunized 9 times: first time they were injected with the recombinant vaccinia virus, and then 8 times – with pseudovirus particles (based on lentivirus and a recombinant strain of the vesicular stomatitis virus). The accumulation of specific antibodies was evaluated by enzyme-linked immunosorbent assay (ELISA). We used recombinant VSV exhibiting GP MARV, and natural MARV strain Popp for the analysis of accumulation of neutralizing antibodies.Results and discussion. We have developed an effective immunization schedule for chickens with three recombinant constructs presenting GP MARV, which results in the induction of chicken IgY antibodies against Marburg virus with a titer in ELISA from 1:100 to 1:1 million. The obtained IgY neutralize MARV pseudoviruses (Popp, DRC2000, Musoke) at a dilution of 1/256 to 1/1024 and the natural MARV virus of the Popp strain at a dilution of 1/8. More stable results were demonstrated by immunization using Freund’s incomplete adjuvant

    Research of Influence of Elements of Yoga on Flexibility and Health of Dancers at the Initial Stage of Enablement

    Full text link
    The article considers the possibility of using yoga elements to increase the flexibility of children engaged in dancing. Yoga is now widely used in sports. The effect is noticeable in such disciplines as swimming, running and biking. We did not find any work to study the effectiveness of yoga in dancers. Experimental studies have shown not only the effectiveness of using yoga in the process of stretching dancers, but also the positive effect of asana on the health indicators of the people involved.В статье рассматривается возможность применения элементов йоги для повышения гибкости у танцоров первого года обучения. Йога в настоящее время находит широкое применение в спорте. Эффект заметен в таких дисциплинах, как плавание, бег и велосипедный спорт. Работ по изучению эффективности йоги у танцоров нами обнаружено не было. Экспериментальное исследование позволило выявить не только эффективность использования йоги в процессе растяжки танцоров, но и положительное влияние асан на показатели здоровья занимающихся

    Molecular screening of the VIR strawberry varieties collection for the presence of a marker for the anthracnose black rot resistance gene <i>Rca2</i>

    Get PDF
    Background. Anthracnose black rot caused by the phytopathogenic fungus Colletotrichum acutatum Simmonds became an extremely harmful disease of strawberries in Southern Russia. The disease is widespread throughout the world, and relatively recently it appeared in Russia. Yield losses due to the disease reach up to 80%; besides, the pathogen causes significant plant losses in mother plantations. The most reliable protection against the pathogen is the cultivation of resistant varieties. In strawberries, resistance is controlled by different genes, including Rca2. To identify this gene, molecular markers STS_Rca2_240 and STS-Rca2_417 have been developed. The purpose of this study was to use the markers for screening the VIR collection of strawberry varieties at the VIR Maikop Experiment Station (Maikop ES VIR). Material and methods. The present work studied 135 varieties of Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier, 83 domestic and 52 foreign ones. The domestic varieties included 17 created at the Maikop ES. Plants were evaluated for anthracnose field resistance in the Republic of Adygea from 2018 to 2021. Molecular screening was performed using STS_Rca2_240 and STS-Rca2_417, the molecular markers closely linked to the Rca2 gene. Microsatellite primers EMFv020 were used to control the PCR. The cultivar ‘Sudarushka’, in which the presence of STS_Rca2_240 marker was described in the literature, served as a positive control. Results and discussion. The marker Rca2_240 was detected in 22 cultivars from 135 studied. Among domestic varieties, the frequency of the marker was 18.1%, while among the foreign varieties it was slightly lower and amounted to 13.0%. Among the 17 varieties created at the Maykop SE, the marker was found in three: ‘Majkopskaya rannyaya’, ‘Peryt’, and ‘Shapsugskaya’. The association of the diagnostic fragment with resistance was 73.0%. The marker efficiency was not very high due to the significant number of resistant varieties which do not generate the diagnostic fragments. The resistance in such varieties can be provided by other genes, for example, FaRCa1. The STS-Rca2_417 marker was not effective during screening. Conclusion. Twenty-two varieties with the STS_Rca2_240 marker were identified in the VIR collection, maintained at the Maykop ES VIR, 16 of which were resistant to C. acutatum. These varieties represent a valuable breeding material. The STS-Rca2_240 marker can be used as an important diagnostic trait for the certification of varieties

    THE EVALUATION OF COMPLIANCE TO ANTIHYPERTENSIVE THERAPY IN PATIENTS AFTER STROKE AND POSTSTROKE DEPRESSION DURING ANTIDEPRESSANT THERAPY

    Get PDF
    Aim. To study the effect of the antidepressant paroxetine on the compliance to antihypertensive therapy in patients with arterial hypertension (HT) and post-stroke depression.Material and methods. Patients (n=24) aged 55-73 with controlled HT (blood pressure, BP&lt;140/90 mm Hg) and with subclinical poststroke depression after rehabilitation course were included into the study. Patients were split into two groups. Patients of group 1 (n=12) received adequate antihypertensive therapy and selective serotonin reuptake inhibitor paroxetine. Patients of group 2 (n=12) received antihypertensive therapy only. The study duration was 16 weeks. Patient compliance to antihypertensive therapy, BP and severity of depressive disorders, motor and intellectual functions was evaluated initially and after 16 weeks.Results. BP&gt;140/80 mmHg after 16 weeks was found in 10 (41.6%) patients. Clinical post-stroke depression was found in 7 (30.4%) patients, 5 (41.6%) of them were from group 2 (OR=0.35, 95% CI 0.12-0.78). High treatment compliance was in 15 (65.2%) patients, and 9 (81.8%) of them were from group 1. Nine (39.1%) patients did not receive an adequate antihypertensive therapy, 5 (41.6%) of them were from group 2 and could not explain their refusal from medication. General index of intellectual function was higher in patients of group 1 (p=0.034) than this in group 2; index of motor function did not change significantly (p&gt;0.05).Conclusion. Reduction of compliance to antihypertensive therapy and rehabilitation in hypertensive patients after stroke is associated with unmotivated refusal from treatment because of clinical post-stroke depression
    corecore