Test-Driven Development - Development Through Testing: Advantages and Disadvantages

This article is devoted to the TDD development method. Its advantages and disadvantages are analyzed

Software implementation of Dijkstra’s algorithm

Currently, there are many algorithms to find the shortest way. The most effective of them is Dijkstra's algorithm. This article is devoted to the software implementation of this algorithm and its interface design, convenient for the use of schoolchildren, students and teachers in order to quickly resolve the problem of finding the shortest way

Entanglement measurement of the quadrature components without the homodyne detection in the spatially multi-mode far-field

We consider the measuring procedure that in principle allows to avoid the homodyne detection for the simultaneous selection of both quadrature components in the far-field. The scheme is based on the use of the coherent sources of the non-classical light. The possibilities of the procedure are illustrated on the basis of the use of pixellised sources, where the phase-locked sub-Poissonian lasers or the degenerate optical parametric oscillator generating above threshold are chosen as the pixels. The theory of the pixellised source of the spatio-temporal squeezed light is elaborated as a part of this investigation.Comment: 11 pages, 5 figures, RevTeX4. Submitted to Phys. Rev.

Working Students: Educational Success and Subjective Well-being

Recently, there has been an increase in the number of students who combine study with work. This requires special attention of universities to such students and updates the study of educational success factors. The study is relevant as considers working students as subjects of learning and life, from the standpoint of personal and professional development experience acquired at the university, involvement in the educational process, satisfaction with learning, and well-being.The purpose of the empirical study is to identify the features of educational experience, subjective well-being and self-change potential among working students. The study involves 290 students of bachelor and specialist programs from five universities. The sample includes students who work for more than half a year (N=95), work from time to time (N=90) and study only (N=105). The results showed that the educational experience is most formed among those students who combine their studies with work in the specialty which is being received at the university. Long-term and occasionally working students differ from non-working students by a higher desire to participate in developmental activities, confidence in their ability to successfully solve the problems of learning and social interaction, self-directed learning skills, tendency to analyze and self-control their learning.Also, working students are superior to those who are just studying in the self-change potential and the subjective well-being level. It is concluded that the success and well-being of working students are largely determined by their resources of subjectness and aspiration for development. This allows them to function successfully, combining educational and labor activities as two areas of experience accumulation. Directions for improving university practice in terms of creating conditions for the educational success of working students are proposed

Нейропротективное действие хлорида лития на модели остановки сердца у крыс

Lithium chloride, which is used for the treatment of bipolar disorders, has a neuroprotective effect in conditions associated with acute and chronic circulatory disorders.The purpose of the study: to investigate the efficacy of lithium chloride for the prevention of post-resuscitation death of hippocampal neurons during the post-resuscitation period.Material and methods. Cardiac arrest for 10 minutes was evoked in mature male rats by intrathoracic clumping of the vascular bundle of the heart, followed by resuscitation. 40 mg/kg or 20 mg/kg of 4,2% lithium chloride (LiCl) was injected intraperitoneally 1 hour before cardiac arrest, on the 1st and 2nd day after resuscitation (n=9). Untreated animals received equivalent doses of saline (n=9). Rats after a sham surgery served as a reference group (n=10). The number of viable neurons in the CA1 and CA3/CA4 fields of the hippocampus was estimated in slides stained with cresyl violet by day 6 or 7 postresuscitation. In a separate series of experiments, at the same terms, we studied the effect of lithium chloride on the protein content of GSK3β (glycogen synthase kinase) in brain tissue using Western-Blot analysis.Results. Histological assay showed that a 10-minute cardiac arrest resulted in a decrease in the number of viable neurons in the hippocampal CA1 field — by 37.5% (P0.001), in the CA3/CA4 field — by 12.9% (P0.05) vs. the reference group. Lithium treatment increased the number of viable neurons in resuscitated rats — in the CA1 field by 37% (P<0.01), in the CA3/CA4 field — by 11.5% (P0.1) vs. the untreated animals. It was found that lithium caused an increase in phosphorylated form of GSK3β: by 180% vs. the reference group (P[1]0.05), and by 150% vs. the untreated animals (P0.05).Conclusion. Lithium treatment leads to a pronounced neuroprotection in the neuronal populations of the hippocampus post-resuscitation. This effect may be due to an increase in the content of the phosphorylated form of GSK3β protein. The results indicate a high potential of lithium for the prevention and treatment of neurodegenerative disorders caused by a temporary arrest of blood circulation. Хлорид лития, используемый для коррекции биполярных расстройств, обладает нейропротективным эффектом при состояниях, связанных с острым и хроническим нарушением кровообращения в головном мозге. Цель исследования — оценить эффективность хлорида лития для предотвращения гибели высокочувствительных к гипоксии нейронов гиппокампа в постреанимационном периоде после временной остановки сердца. Материал и методы. Остановку сердца у взрослых крыс-самцов на 10 минут вызывали путем внутриторакального пережатия сосудистого пучка сердца с последующей реанимацией. 9-ти животным вводили раствор 4,2% LiCl за 1 час до остановки сердца (40 мг/кг в/б), на 1-е и на 2-е сутки после реанимации (20 мг/кг в/б, соответственно). 9 нелеченых животных в те же сроки получали эквивалентные дозы физиологического раствора хлорида натрия. Контролем служили ложноперированные крысы (n=10). Через 7 дней методом морфометрического анализа оценили число жизнеспособных нейронов в полях СА1 и СА3/СА4 гиппокампа на срезах, окрашенных крезиловым фиолетовым по Нисслю. В отдельной серии экспериментов с помощью Western-Blot анализа в эти же сроки исследовали влияние хлорида лития на содержание белка GSK3β (киназа гликогенсинтазы киназы-3) в ткани мозга. Результаты. При гистологическом исследовании установили, что 10-минутная остановка сердца приводит к снижению числа жизнеспособных нейронов в поле СА1 гиппокампа — на 37,5% (p0,001), в поле СА3/СА4 — на 12,9% (p0,05). Применение LiCl приводило к увеличению числа жизнеспособных нейронов гиппокампа у реанимированных крыс в поле СА1 на 37% (p0,01), в поле СА3/СА4 — на 11,5% (p0,1) по сравнению с нелечеными животными.  При исследовании белка GSK3β установили, что у реанимированных животных, получавших хлорид лития, содержание его фосфорилированной формы в ткани мозга было выше на 180% по сравнению с контролем (р0,05), и на 150% выше, чем у нелеченных животных (р0,05). Заключение. Введение хлорида лития в постреанимационном периоде приводило к выраженной нейропротекции в нейрональных популяциях гиппокампа. Этот эффект может быть обусловлен повышением содержания фосфорилированной формы белка GSK3β. Полученные результаты свидетельствуют о высоком потенциале лития для профилактики и лечения нейродегенеративных нарушений, вызванных временной остановкой кровообращения.

Experience in the use of docosahexaenoic acid (BrudiPlus) in patients with increased sperm DNA fragmentation index in Acad. V.I. Kulakov Research Center for Obstetrics, Gynecology and Perinatology

Male factor is the reason of infertility in almost half of marriages. Infertile men have the percentage of sperm with violations of DNA integrity of over 30 %; with that, healthy fertile men have that indicator of less than 15 %. Understanding of importance of damages of sperm DNA is growing with distribution ofauxiliary reproductive technologies. As of today, these consequences have not been studies yet, and the therapeutic effect of intake of antioxidants has not direct correlation with the sperm DNA fragmentation level. Docosahexaenoic acid is one of the most valuable omega-3 polyunsaturated fatty acids for human health. Docosahexaenoic acid is the main component of the brain gray matter, retina, testes, and sperm cell membranes. In connection with that, a study was held the purpose of which was to assess the effect of the nutraceutical enzymatic docosahexaenoic acid triglyceride (BrudiPlus) in high concentrations on damaged sperm DNA of patients with idiopathic pathozoospermia. 40 patients with idiopathic pathozoospermia and the level of DNA fragmentation over the statutory value took part in this study. The following positive results were received: intake of BrudiPlus allowed decreasing sperm DNA damages and improving of antioxidant system of sperm

Maternal incompatibilities with fetal human platelet alloantigens -1a, -1b and -15 are the main causes of neonatal alloimmune thrombocytopenia in Russia

The aim. Mechanisms underlying the development of neonatal alloimmune thrombocytopenia (NAIT) in in Russia have been studied. Materials and methods. Genetic polymorphisms of human platelet alloantigens (HPA) -1, -2, -3, -4, -5, and -15 were evaluated in 27 families having the newborns with NAIT. NAIT was diagnosed according to the following criteria: (1) newborn with thrombocytopenia; (2) mother with no thrombocytopenia and no increase of platelet associated IgG, (3) presence of antibodies reacting with paternal platelets in maternal plasma / serum. HPA genotyping revealed incompatibilities in 23 out of 27 tested families. In these 23 families HPA-1 conflicts were detected in 16 ones (70%). In 8 cases mothers were homozygous carriers of rare HPA-1b allele and in another 8 cases - of HPA-1a allele which cased incompatibilities with fetal HPA-1a and HPA-1b respectively. In 5 out of 23 families (22%) there were incompatibilities with fetal HPA-15 (HPA-15a, n=2 and HPA-15b, n=3), in 1 family - with HPA-5b (4%), and in 1 family - with HPA-3b (4%) alloantigens. In conclusion the main causes of NAIT in Russia were HPA-1a and -1b conflicts and HPA-15 conflicts were the second frequent ones

Ribosomal profiling as a tool for studying translation in plants: main results, problems and future prospects

The expression of eukaryotic genes can be regulated at several stages, including the translation of mRNA. It is known that the structure of mRNA can affect both the efficiency of interaction with the translation apparatus in general and the choice of translation initiation sites. To study the translated fraction of the transcriptome, experimental methods of analysis were developed, the most informative of which is ribosomal profiling (RP, Ribo-seq). Originally developed for use in yeast systems, this method has been adapted for research in translation mechanisms in many plant species. This technology includes the isolation of the polysomal fraction and high-performance sequencing of a pool of mRNA fragments associated with ribosomes. Comparing the results of transcript coverage with reads obtained using the ribosome profiling with the transcriptional efficiency of genes allows the translation efficiency to be evaluated for each transcript. The exact positions of ribosomes determined on mRNA sequences allow determining the translation of open reading frames and switching between the translation of several reading frames – a phenomenon in which two or more overlapping frames are read from one mRNA and different proteins are synthesized. The advantage of this method is that it provides quantitative estimates of ribosome coverage of mRNA and can detect relatively rare translation events. Using this technology, it was possible to identify and classify plant genes by the type of regulation of their expression at the transcription, translation, or both levels. Features of the mRNA structure that affect translation levels have been revealed: the formation of G2 quadruplexes and the presence of specific motifs in the 5’-UTR region, GC content, the presence of alternative translation starts, and the influence of uORFs on the translation of downstream mORFs. In this review, we briefly reviewed the RP methodology and the prospects for its application to study the structural and functional organization and regulation of plant gene expression

Climate-driven phenological changes in the Russian Arctic derived from MODIS LAI time series 2000–2019

Abstract: Arctic surface temperature has increased at approximately twice the global rate over the past few decades and is also projected to warm most in the 21st century. However, the mechanism of Arctic vegetation response to this warming remains largely uncertain. Here, we analyse variations in the seasonal profiles of MODerate resolution Imaging Spectroradiometer Leaf Area Index (LAI) and ERA-interim cumulative near-Surface Air Temperature (SATΣ) over the northern Russia, north of 60° N for 2000–2019. We find that commonly used broad temporal interval (seasonal) trends cannot fully represent complex interannual variations of the LAI profile over the growing season. A sequence of narrow temporal interval (weekly) LAI trends form an inverted S-shape over the course of the growing season with enhanced green-up and senescence, but balanced during the growing season’s peak. Spatial patterns of weekly LAI trends match with those of weekly SATΣ trends during the green-up, while the drivers of the browning trends during senescence remain unclear. Geographically the area with the statistically significant temperature-driven enhanced green-up is restricted by a large patch carrying significant positive SATΣ trends, which includes North Siberian Lowland, Taimyr, Yamal and adjacent territories. The strength, duration and timing of the changes depend on vegetation type: enhanced green-up is most pronounced in tundra, while enhanced senescence is pronounced in forests. Continued release of the climatic constraints will likely increase the capacity both of the environment (i.e. permafrost thawing) and vegetation (i.e. appearance of more productive woody species), and transform LAI seasonal shifts to change of LAI seasonal amplitude