253 research outputs found

    Propagation of rotational waves in a block geomedium

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    On the base of assumption that the rotational movements of the chain of the crust blocks and the corresponding rotational waves characterizing the redistribution of tectonic stresses are described by the sine-Gordon equation with dissipation, the dispersion properties of this equation are analyzed. It is shown that the dispersion is manifested in the low-frequency range at high values of the dissipation factor. The presence of anomalous dispersion has been revealed for all values of the dissipation factor. Influence of this factor on dispersion is investigated. Some features of propagation of a stationary shock wave in a geomedium are studied. It has been found that the shock wave front width is directly proportional to the nonlinear wave velocity and to the dissipation factor of the medium, but it is inversely proportional to the nonlinearity coefficient

    Genome-wide screening for genes whose deletions confer sensitivity to mutagenic purine base analogs in yeast

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    BACKGROUND: N-hydroxylated base analogs, such as 6-hydroxylaminopurine (HAP) and 2-amino-6-hydroxylaminopurine (AHA), are strong mutagens in various organisms due to their ambiguous base-pairing properties. The systems protecting cells from HAP and related noncanonical purines in Escherichia coli include specialized deoxyribonucleoside triphosphatase RdgB, DNA repair endonuclease V, and a molybdenum cofactor-dependent system. Fewer HAP-detoxification systems have been identified in yeast Saccharomyces cerevisiae and other eukaryotes. Cellular systems protecting from AHA are unknown. In the present study, we performed a genome-wide search for genes whose deletions confer sensitivity to HAP and AHA in yeast. RESULTS: We screened the library of yeast deletion mutants for sensitivity to the toxic and mutagenic action of HAP and AHA. We identified novel genes involved in the genetic control of base analogs sensitivity, including genes controlling purine metabolism, cytoskeleton organization, and amino acid metabolism. CONCLUSION: We developed a method for screening the yeast deletion library for sensitivity to the mutagenic and toxic action of base analogs and identified 16 novel genes controlling pathways of protection from HAP. Three of them also protect from AHA

    Digital Transformation of Additional Professional Education: Features of the LK-14 Educational Platform

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    This article substantiates the relevance of the transformation of the educational environment of additional professional education (APE) in the Republic of Sakha (Yakutia). This study aims to justify the transformation of the educational environment of APE in the context of digitalization and to consider the prospects for targeted professional development of teachers in the republic according to their needs. The authors chose this scientific topic due to the pressing needs of Russian continuing professional education (CPE) and current problems such as the lack of unified approaches and mechanisms for regulating the professional development of teachers in the digital educational environment and the lack of methods for monitoring the effectiveness and efficiency of CPE distance learning programs. Creating an innovative and dynamic CPE system requires the intensive introduction of information technologies into education. These technologies ensure that the learning process is open and of high quality, as well as provide access to global educational resources. This helps learners create “their own individual educational environment” reflecting their needs and requirements. The research methods used to explore this problem were a pedagogical experiment, the analysis of the organization of CPE of teachers in the region, designing a regional model of targeted personalized training of educators and administration. The research results include the specifics of APE modernization in the region and the model of targeted personalized training of teachers of the republic. The qualitative novelty of this model stems from the fact that developing teachers’ competencies involves identifying gaps in their professional knowledge and building individual learning paths

    Expression of human AID in yeast induces mutations in context similar to the context of somatic hypermutation at G-C pairs in immunoglobulin genes

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    BACKGROUND: Antibody genes are diversified by somatic hypermutation (SHM), gene conversion and class-switch recombination. All three processes are initiated by the activation-induced deaminase (AID). According to a DNA deamination model of SHM, AID converts cytosine to uracil in DNA sequences. The initial deamination of cytosine leads to mutation and recombination in pathways involving replication, DNA mismatch repair and possibly base excision repair. The DNA sequence context of mutation hotspots at G-C pairs during SHM is DGYW/WRCH (G-C is a hotspot position, R = A/G, Y = T/C, W = A/T, D = A/G/T). RESULTS: To investigate the mechanisms of AID-induced mutagenesis in a model system, we studied the genetic consequences of AID expression in yeast. We constructed a yeast vector with an artificially synthesized human AID gene insert using codons common to highly expressed yeast genes. We found that expression of the artificial hAIDSc gene was moderately mutagenic in a wild-type strain and highly mutagenic in an ung1 uracil-DNA glycosylase-deficient strain. A majority of mutations were at G-C pairs. In the ung1 strain, C-G to T-A transitions were found almost exclusively, while a mixture of transitions with 12% transversions was characteristic in the wild-type strain. In the ung1 strain mutations that could have originated from deamination of the transcribed stand were found more frequently. In the wild-type strain, the strand bias was reversed. DGYW/WRCH motifs were preferential sites of mutations. CONCLUSION: The results are consistent with the hypothesis that AID-mediated deamination of DNA is a major cause of mutations at G-C base pairs in immunoglobulin genes during SHM. The sequence contexts of mutations in yeast induced by AID and those of somatic mutations at G-C pairs in immunoglobulin genes are significantly similar. This indicates that the intrinsic substrate specificity of AID itself is a primary determinant of mutational hotspots at G-C base pairs during SHM

    Human Capital of Transnational Corporations in the Energy Sector

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    For the development of the energy sector, at the present stage, it is necessary to use certain resources. The paper analyzed the application of human capital in the energy sector. To achieve this goal, the authors used the method of offset. It is established that the world energy consumption increases, and the dynamics of the employed population in the energy sector remains within the same norm. It is determined that an important factor for the development of the economy is the gross regional product. As its increase helps to reduce energy intensity. The authors show that human potential is not only a personal characteristic received by the employee independently, but also by the acquired position, which is ensured by the implementation of corporate tools. The paper considers the economic, social and legal provision of such instruments. Keywords: labor resources, electrification, energy efficiency, expert evaluation, energy system. JEL Classifications: A10, P48 DOI: https://doi.org/10.32479/ijeep.690

    Two-component generalizations of the Camassa-Holm equation

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    A classification of integrable two-component systems of non-evolutionary partial differential equations that are analogous to the Camassa-Holm equation is carried out via the perturbative symmetry approach. Independently, a classification of compatible pairs of Hamiltonian operators is carried out, which leads to bi-Hamiltonian structures for the same systems of equations. Some exact solutions and Lax pairs are also constructed for the systems considered

    КЛИНИЧЕСКИЙ СЛУЧАЙ ЭНДОВАСКУЛЯРНОГО ЛЕЧЕНИЯ ПОСТТРАВМАТИЧЕСКОЙ АНЕВРИЗМЫ ПОЧЕЧНОЙ АРТЕРИИ

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    Introduction. Aneurysm of renal artery is a rare and complex pathology of renal bloodstream. Large percentage of observations show that renal artery aneurysms are iatrogenic and happen due to urological interventions. Traumatic aneurysms are much less frequent. By the nature of the blood supply arterial aneurysms are subdiveded into those, which occur when the injured organ is only artery and arteriovenous aneurysms that occur while an artery is damaged along with the accompanying veins. Aneurysms may be treated only surgically, and the only exception is pregnancy. It is possible to use the open treatment option such as aneurysm resection with prosthetics, reanastomosing or its collateral plastics of the renal artery; exclusion of aneurysm with shunting of renal artery or its branches; resection of aneurysm with anastomosing of artery with azygos splanchnic arteries; complex reconstruction using autovein or internal iliac artery segment; including kidney resection at local infarction or nephrectomy in the case of evident nephrosclerosis.Materials and methods. This paper presents a clinical case of successful minimally invasive surgical treatment of traumatic aneurysm of renal artery. It was carried out through stenting of the right lowpolar renal artery: a coronary sheath was used to transfuse and implant the Explorer-Itgimedical Aneugraft 3.0 * 18.0 mm graft-system; the stent-graft was implanted into the right lowpolar renal artery so that it covers the aneurysm ostium. Results. The above case shows the possibility to successfully apply the endovascular method to treat posttraumatic aneurysms of renal arteries with derivative circulation.Conclusion. This technique can be safely and successfully used as an alternative to the traditional «open» surgery, as it is minimally invasive, and allows performing a complete blockade of the pathological blood flow and to avoid an additional operating trauma and compromenation of distal branches. Введение. Аневризма почечных артерий – редкая и сложная патология сосудистого русла почки. В большом проценте наблюдений аневризмы почечных артерий являются ятрогенными, возникающими в результате интервенционных урологических вмешательств. Травматические аневризмы встречаются значительно реже. По характеру кровоснабжения различают артериальные аневризмы, возникающие при ранении только артерии, и артериовенозные аневризмы, возникающие при одновременном повреждении артерии и сопутствующей вены. Лечение аневризм возможно только хирургическим способом, исключением является только беременность. Возможно применение открытых методов лечения, таких как резекция аневризмы с протезированием, реанастомозированием или ее боковой пластикой почечной артерии; выключение аневризмы с шунтированием почечной артерии или ее ветвей; резекция аневризмы с анастомозированием артерии с непарными висцеральными артериями; сложные реконструкции с использованием аутовены или сегмента внутренней подвздошной артерии; в том числе применение резекции почки при локальном инфаркте или нефрэктомии в случае выраженного нефросклероза. Материалы и методы. В данной работе представлен клинический случай успешного малоинвазивного хирургического лечения травматической аневризмы почечной артерии. Для этого выполнено стентирование правой нижнеполюсной почечной артерии: по коронарному проводнику проведена и имплантирована графт-система Itgimedical Aneugraft 3,0*18,0 мм – стент-графт имплантирован в нижнеполюсную правую почечную артерию с перекрытием шейки аневризмы.Результаты. Приведенный случай показывает возможность успешного применения эндоваскулярного метода для лечения посттравматических аневризм почечных артерий с артериовенозным сбросом.Заключение. Данная методика может безопасно и с успехом применяться в качестве альтернативы традиционного «открытого» хирургического вмешательства, поскольку она малоинвазивна, позволяет выполнять полную блокаду патологического кровотока, избегать дополнительной операционной травмы и компрометации дистальных ветвей.

    The c4h, tat, hppr and hppd Genes Prompted Engineering of Rosmarinic Acid Biosynthetic Pathway in Salvia miltiorrhiza Hairy Root Cultures

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    Rational engineering to produce biologically active plant compounds has been greatly impeded by our poor understanding of the regulatory and metabolic pathways underlying the biosynthesis of these compounds. Here we capitalized on our previously described gene-to-metabolite network in order to engineer rosmarinic acid (RA) biosynthesis pathway for the production of beneficial RA and lithospermic acid B (LAB) in Salvia miltiorrhiza hairy root cultures. Results showed their production was greatly elevated by (1) overexpression of single gene, including cinnamic acid 4-hydroxylase (c4h), tyrosine aminotransferase (tat), and 4-hydroxyphenylpyruvate reductase (hppr), (2) overexpression of both tat and hppr, and (3) suppression of 4-hydroxyphenylpyruvate dioxygenase (hppd). Co-expression of tat/hppr produced the most abundant RA (906 mg/liter) and LAB (992 mg/liter), which were 4.3 and 3.2-fold more than in their wild-type (wt) counterparts respectively. And the value of RA concentration was also higher than that reported before, that produced by means of nutrient medium optimization or elicitor treatment. It is the first report of boosting RA and LAB biosynthesis through genetic manipulation, providing an effective approach for their large-scale commercial production by using hairy root culture systems as bioreactors
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