GMF Severs Actin-Arp2/3 Complex Branch Junctions by a Cofilin-like Mechanism

SummaryBackgroundBranched actin filament networks driving cell motility, endocytosis, and intracellular transport are assembled in seconds by the Arp2/3 complex and must be equally rapidly debranched and turned over. One of the only factors known to promote debranching of actin networks is the yeast homolog of glia maturation factor (GMF), which is structurally related to the actin filament-severing protein cofilin. However, the identity of the molecular mechanism underlying debranching and whether this activity extends to mammalian GMF have remained open questions.ResultsUsing scanning mutagenesis and total internal reflection fluorescence microscopy, we show that GMF depends on two separate surfaces for debranching. One is analogous to the G-actin and F-actin binding site on cofilin, but we show using fluorescence anisotropy and chemical crosslinking that it instead interacts with actin-related proteins in the Arp2/3 complex. The other is analogous to a second F-actin binding site on cofilin, which in GMF appears to contact the first actin subunit in the daughter filament. We further show that GMF binds to the Arp2/3 complex with low nanomolar affinity and promotes the open conformation. Finally, we show that this debranching activity and mechanism are conserved for mammalian GMF.ConclusionsGMF debranches filaments by a mechanism related to cofilin-mediated severing, but in which GMF has evolved to target molecular junctions between actin-related proteins in the Arp2/3 complex and actin subunits in the daughter filament of the branch. This activity and mechanism are conserved in GMF homologs from evolutionarily distant species

Vocational Guidance: Harmonization of Points of View

The problem of harmonization of different views on career-oriented work, due to the diversity of ideas about life and career success, as well as about the ways to success, is considered. The authors conditionally called the phenomenon of the plurality of interpretations of the content of this concept “vocational orientation pluralism”. The positions of the self-determining personality, psychologists-career advisors, methodologists, scientist- career guides, employers are considered. Differences in the understanding of the essence of vocational guidance by all named subjects of interaction are characterized. The mismatch of their expectations in relation to the professional advisers is emphasized. It is alleged that managers of enterprises and organizations conduct different personnel policies, depending on their awareness of the importance of human potential. Vocational guidance is interpreted in the context of the cultural and historical development of society. The authors identify the points of incompatibility of different positions in the understanding of vocational guidance and offer generalized variants (ways) for harmonizing opinions. The first group consists of variants of “external” harmonization, that is, ways of coordinating opinions between subjects that in one way or other participate in vocational guidance. The second group consists of variants of “internal” harmonization that is between people representing one social or professional group, interested in solving career counseling issues

Phytoinsecticides to Fight Against Colorado Beetle

Nowadays researchers are focused on biological farming. In modern environmental conditions the reduction of the chemical load on the environment is a current issue. In the article the following plants are used as pest management, especially, with Colorado potato beetle: jimson weed, white hellebore, Camelina. They contain a lot of alkaloids and essential oils that inhibit weeds and frightening off potato pests. The use of such agricultural practices on large areas reduces the cost of chemical means of pest control and improves product quality while maintaining the environment

Randomized Reference Classifier with Gaussian Distribution and Soft Confusion Matrix Applied to the Improving Weak Classifiers

In this paper, an issue of building the RRC model using probability distributions other than beta distribution is addressed. More precisely, in this paper, we propose to build the RRR model using the truncated normal distribution. Heuristic procedures for expected value and the variance of the truncated-normal distribution are also proposed. The proposed approach is tested using SCM-based model for testing the consequences of applying the truncated normal distribution in the RRC model. The experimental evaluation is performed using four different base classifiers and seven quality measures. The results showed that the proposed approach is comparable to the RRC model built using beta distribution. What is more, for some base classifiers, the truncated-normal-based SCM algorithm turned out to be better at discovering objects coming from minority classes.Comment: arXiv admin note: text overlap with arXiv:1901.0882

Combination of linear classifiers using score function -- analysis of possible combination strategies

In this work, we addressed the issue of combining linear classifiers using their score functions. The value of the scoring function depends on the distance from the decision boundary. Two score functions have been tested and four different combination strategies were investigated. During the experimental study, the proposed approach was applied to the heterogeneous ensemble and it was compared to two reference methods -- majority voting and model averaging respectively. The comparison was made in terms of seven different quality criteria. The result shows that combination strategies based on simple average, and trimmed average are the best combination strategies of the geometrical combination

Problems of preserving the natural and cultural heritage of the pre-polar region - Karelian Pomorie

Karelian Pomorie is part of the historical and geographical province of Pomorie in the North-West of Russia, stretching along the coast of the White Sea within the modern polar regions of the Russian Federation: Karelia, Murmansk and Arkhangelsk oblast. The object of our research is the part of Pomorie area within the borders of the Republic of Karelia. On the scheme of historical and geographical zoning of Karelia, the territory received the name of the Pomorie province. The isolation of the province is associated with special landscapes - the White Sea-based basement and marine accumulative northern taiga lowlands, which determined the nature of the use of natural resources and the specialization of the economy, which have repeatedly changed in historical time. The main approach in conducting the study is historical and geographical, allowing for a retrospective analysis of changes in the natural environment and to trace the stages of interaction between the landscape and ethnic group. The nature of the region has many specific features: the landscapes of the Karelian Pomorie, due to their mobility and dynamism associated with the youthful formation, require special attention and protection. Landscapes of Pomorie possess a specific set of natural resources, determine the special nature use in the marginal coastal zone, where the seaside nature use prevailed. The landscapes of Pomorie repeatedly became tribal, accommodating for several ethnic groups (Saami, Karelian, Russian Pomorie). The interaction of the landscape and ethnos is in particular, in the specific historical nature management of each local ethnic group left traces in the form of historical and cultural monuments. Some of these objects were identified, substantiated and received a certain well-deserved status of a protected area. The problem under consideration aims to “add” the region of Karelian Pomorie to the World Map. It is necessary to show the uniqueness of the landscapes of the region, to indicate the change of ethnic groups and the specifics of their interaction with the natural environment. It is very important to assess the current state of the regional network of specially protected natural territories: to identify unresolved problems with a clearly insufficient number of specially protected natural territories, to offer solutions to this issue. The results of the interaction of ethnos and landscape are the new types of environmental management, many left "traces" of each ethnic group in the northern landscapes in the form of historical monuments of cultural heritage, including the stratigraphy of toponymic names - that were the object of studying regional geographical terminology

ЧАРОИТ. ЭКСПЕРИМЕНТАЛЬНЫЕ ИССЛЕДОВАНИЯ

The article provides an overview of experimental studies of charoite and charoite-containing rock formation hypotheses. The authors conducted experiments to clarify charoite and host rocks interaction and study charoite transformation processes at high temperatures. A series of experiments was aimed at improving the substandard charoite samples. The experiments show the formation of polymineral reaction zones due to the contact interaction between charoite and microcline-arfvedsonite lamprophyre. By studying the newly formed phases, the authors reveal the distribution of elements by phases and establish their compositions. It is shown that thermal decomposition of charoite leads to the formation of wollastonite, which amount increases with the temperature increase from 800 to 1000 °C, and heating above 1200 °C leads to the formation of pseudowollastonite. The physicochemical simulation of charoite decomposition under the specified temperatures and pressure shows the following paragenesis: quartz, wollastonite, alkaline pyroxene (aegerine), microcline, rhodonite, and sphene.The experiments prove the formation of charoite at low temperatures and the lack of silicate melt in the systems studied. The calculated values are consistent with the results of experiments conducted to study the charoite and host rocks interaction, which allows identifying phases potentially co-existing with wollastonite.Special studies using by the coloring technique were conducted to improve the decorative properties of charoite. The color close to natural high-grade charoite coloration was achieved by keeping the rock samples in the active bright purple dye 4KT solution for 72 hours at a temperature of 70 to 90 °C.Приведен обзор экспериментальных исследований чароита в России и в мире. Рассмотрены гипотезы формирования чароитовых пород. Для выяснения характера взаимодействия чароитового субстрата с вмещающими породами и исследования процессов преобразования чароита при повышенных температурах проведен ряд экспериментов. Кроме того, изучены возможности повышения сортности некондиционных чароититов. При экспериментальном исследовании контактового взаимодействия чароитового субстрата с лампрофиром микроклин-арфведсонитового состава установлено образование реакционных полиминеральных зон. Исследование новообразованных фаз позволило изучить распределение элементов по фазам и получить их составы. Показано, что при термическом разложении чароита происходит его преобразование в волластонит, количество которого увеличивается с ростом температуры от 800 до 1000 °С, при нагревании выше 1200 °С образуется псевдоволластонит. Согласно проведенному физико-химическому моделированию разложения чароита, из различных составов минерала при заданных температурах и давлении образуется следующий парагенезис: кварц, волластонит, щелочной пироксен (эгирин), микроклин, родонит и сфен.Проведенные эксперименты подчеркивают низкотемпературный характер чароитообразования и показывают отсутствие силикатного расплава в исследованных системах. Результаты расчетов согласуются с проведенными экспериментами по взаимодействию чароита с вмещающими породами и его отжигу и позволяют определить возможные сосуществующие с волластонитом фазы.Исследования по улучшению декоративно-художественных свойств чароититов методом окрашивания показали, что для получения окраски чароититов, близкой к окраске высокосортных природных образцов, требуется выдержка образцов в растворе активного ярко-фиолетового красителя 4КТ при длительности 72 ч и температуре 70–90 °C

Lumpability Abstractions of Rule-based Systems

The induction of a signaling pathway is characterized by transient complex formation and mutual posttranslational modification of proteins. To faithfully capture this combinatorial process in a mathematical model is an important challenge in systems biology. Exploiting the limited context on which most binding and modification events are conditioned, attempts have been made to reduce the combinatorial complexity by quotienting the reachable set of molecular species, into species aggregates while preserving the deterministic semantics of the thermodynamic limit. Recently we proposed a quotienting that also preserves the stochastic semantics and that is complete in the sense that the semantics of individual species can be recovered from the aggregate semantics. In this paper we prove that this quotienting yields a sufficient condition for weak lumpability and that it gives rise to a backward Markov bisimulation between the original and aggregated transition system. We illustrate the framework on a case study of the EGF/insulin receptor crosstalk.Comment: In Proceedings MeCBIC 2010, arXiv:1011.005

The impact of Opisthorchis felineus infection and praziquantel treatment on the intestinal microbiota in children

peer reviewedThe presence of some species of helminths is associated with changes in host microbiota composition and diversity, which varies widely depending on the infecting helminth species and other factors. We conducted a prospective case-control study to evaluate the gut microbiota in children with Opisthorchis felineus infection (n=50) before and after anthelmintic treatment and in uninfected children (n=49) in the endemic region. A total of 99 children and adolescents aged between 7 and 18 years were enrolled to the study. Helminth infection was assessed before and at 3 months after treatment with praziquantel. A complex examination for each participant was performed in the study, including an assessment of the clinical symptoms and an intestinal microbiota survey by 16S rRNA gene sequencing of stool samples. There was no change in alpha diversity between O. felineus-infected and control groups. We found significant changes in the abundances of bacterial taxa at different taxonomic levels between the infected and uninfected individuals. Enterobacteriaceae family was more abundant in infected participants compared to uninfected children. On the genus level, O. felineus-infected participants’ microbiota showed higher levels of Lachnospira, Escherichia-Shigella, Bacteroides, Eubacterium eligens group, Ruminiclostridium 6, Barnesiella, Oscillibacter, Faecalitalea and Anaerosporobacter and reduction of Blautia, Lachnospiraceae FCS020 and Eubacterium hallii group in comparison with the uninfected individuals. Following praziquantel therapy, there were significant differences in abundances of some microorganisms, including an increase of Faecalibacterium and decrease of Megasphaera, Roseburia. Enterobacteriaceae and Escherichia abundances were decreased up to the control group values. Our results highlight the importance of the host-parasite-microbiota interactions for the community health in the endemic regions. © 202

Impact of hypoglycemia on daily life of type 2 diabetes patients in Ukraine

This study evaluates the impact of hypoglycemia on the lives of Ukrainian patients with type 2 diabetes mellitus. The secondary objective was to explore patient-physician relationships and the attitudes of patients towards various informational resources on diabetes management. Three focus groups with 26 patients were conducted. Qualitative information was evaluated using content analysis. The results show that patients with type 2 diabetes mellitus in Ukraine are adapting to potential attacks of hypoglycemia; however, they still experience periodic manifestations of hypoglycemia that significantly affect their psychological well-being. This result is similar to observations made in other countries. Ukrainian patients >40 years old mainly receive information on disease management from endocrinologists, and rarely use internet resources on diabetes management. Information provision was especially important at the early stage of the disease, when patients lack information on hypoglycemia manifestations and could therefore fail to identify and manage it properly