Theoretical prerequisites for the bionic substantiation of spring soil leveler working bodies parameters

In the system of measures for pre-sowing tillage, special attention should be given to leveling the soil, ensuring an increase in the uniformity of seeding in depth, which has a significant impact on increasing yields. The main solution to this problem is to improve the design of aligners using a mechanical-bionic approach for the analytical description of the optimal forms and parameters of their working bodies. The design of the working body of the spring soil leveler is proposed, the cutting edges of the undercutting wings of which have ridges and hollows in the form of a logarithmic curve with a positive convexity of curvature inside the depressions, developed by the bionic prototype of the mole cricket (Gryllotalpa). Using the methods of agricultural mechanics, the theoretical dependence of the rational depth of the working bodies and the value of the tractive resistance of spring soil leveler on the travel speed, design parameters and physical-mechanical soil properties, which are proved by the results of experimental research on the south carbonated middle loamy black earth have been established. The experimental spring soil leveler provided the reduction of traction resistance by 7...8% (40...49 N) and had the best stability of motion in depth by an average of 1.5 times (± 0.5 cm) in comparison with the serial model of the working bodies of the leveler VPN-5.6 A

Theoretical background for the bionic substantiation of parameters of the stubble cultivator working bodies

In the southern regions of Russia, the technology of cultivation of grain crops in the variant of partial sowing has been widely used. In this regard, it became necessary to create effective working bodies of a stubble cultivator that would have fundamentally new resource-saving ways of influencing the area under cultivating and meet the requirements of modern advanced technologies. The shapes of the working bodies surfaces of the cultivators were improved taking into account the mechanic-bionic approach. The main parameters of the toothed cutting surface were determined by the method of bionic comparisons, with a scarab beetle as a bionic prototype. Use of the serrated shape of the cutting edge is consistent with the bionic principle of multi-contact exposure and leads to the fact that the tops of the teeth become stress concentrators and, with a significantly smaller indentation force, cause soil destruction processes, which reduces the energy costs of cutting the soil layer. The optimal curvilinear shape of the working surface made in the form of a logarithmic spiral, is characterized by a constant value of the angle between the normal and the radius vector, and the value of this angle, equal to the angle of internal friction of the soil φ2, will ensure the sliding of the soil and plant residues with minimal energy consumption. The number (n = 4), height (h = 5...7 mm) and tooth placement step (S = 10...12 mm) of the bit tip of the stubble cultivator are analytically justified. The shape of the profile of the working surface of the stubble cultivator bit in the form of a logarithmic spiral with a variable angle of crumbling is proposed. The studies were conducted in the period from September to October 2018 in the soil channel of the research Laboratory of Bionic Agroengineering of the Department of Mechanization and Technical Service in Agro-Industrial Complex. They have shown the decrease in the traction resistance of the proposed working body of the stubble cultivator by 16.5% in comparison with the traction resistance of the serial sample

Cosmogenic activation of Germanium and its reduction for low background experiments

Production of $^{60}$Co and $^{68}$Ge from stable isotopes of Germanium by nuclear active component of cosmic rays is a principal background source for a new generation of $^{76}$Ge double beta decay experiments like GERDA and Majorana. The biggest amount of cosmogenic activity is expected to be produced during transportation of either enriched material or already grown crystal. In this letter properties and feasibility of a movable iron shield are discussed. Activation reduction factor of about 10 is predicted by simulations with SHIELD code for a simple cylindrical configuration. It is sufficient for GERDA Phase II background requirements. Possibility of further increase of reduction factor and physical limitations are considered. Importance of activation reduction during Germanium purification and detector manufacturing is emphasized.Comment: 10 pages, 3 tables, 6 figure

Block of NMDA receptor channels by endogenous neurosteroids: implications for the agonist induced conformational states of the channel vestibule

N-methyl-D-aspartate receptors (NMDARs) mediate synaptic plasticity, and their dysfunction is implicated in multiple brain disorders. NMDARs can be allosterically modulated by numerous compounds, including endogenous neurosteroid pregnanolone sulfate. Here, we identify the molecular basis of the use-dependent and voltage-independent inhibitory effect of neurosteroids on NMDAR responses. The site of action is located at the extracellular vestibule of the receptor's ion channel pore and is accessible after receptor activation. Mutations in the extracellular vestibule in the SYTANLAAF motif disrupt the inhibitory effect of negatively charged steroids. In contrast, positively charged steroids inhibit mutated NMDAR responses in a voltage-dependent manner. These results, in combination with molecular modeling, characterize structure details of the open configuration of the NMDAR channel. Our results provide a unique opportunity for the development of new therapeutic neurosteroid-based ligands to treat diseases associated with dysfunction of the glutamate system

МЕТОД ПОЛУЧЕНИЯ ГРАНИЦ ОБЛАСТЕЙ ОПРЕДЕЛЕНИЯ ФУНКЦИЙ ГЛОБАЛЬНЫХ ЗАВИСИМОСТЕЙ В ЗАДАЧАХ РАСПАРАЛЛЕЛИВАНИЯ ВЫЧИСЛЕНИЙ

A method to obtain the domains of the functions of global dependences based on the refined approximations of the set of tiles is developed. The exact presentation of the boundaries of the domains of the functions of global dependences avoids redundant computations in the performance of communication operations and provides more opportunities for granular paralleling algorithms.Разработан способ получения областей определения функций глобальных зависимостей, основанный на уточненных аппроксимациях множества тайлов. Точное представление границ областей определения функций глобальных зависимостей позволяет избегать избыточных вычислений при выполнении коммуникационных операций и дает больше возможностей для распараллеливания зернистых алгоритмов

Analytical expressions for stopping-power ratios relevant for accurate dosimetry in particle therapy

In particle therapy, knowledge of the stopping-power ratios (STPRs) of the ion beam for air and water is necessary for accurate ionization chamber dosimetry. Earlier work has investigated the STPRs for pristine carbon ion beams, but here we expand the calculations to a range of ions (1 <= z <= 18) as well as spread out Bragg peaks (SOBPs) and provide a theoretical in-depth study with a special focus on the parameter regime relevant for particle therapy. The Monte Carlo transport code SHIELD-HIT is used to calculate complete particle-fluence spectra which are required for determining STPRs according to the recommendations of the International Atomic Energy Agency (IAEA). We confirm that the STPR depends primarily on the current energy of the ions rather than on their charge z or absolute position in the medium. However, STPRs for different sets of stopping-power data for water and air recommended by the International Commission on Radiation Units & Measurements (ICRU) are compared, including also the recently revised data for water, yielding deviations up to 2% in the plateau region. In comparison, the influence of the secondary particle spectra on the STPR is about two orders of magnitude smaller in the whole region up till the practical range. The gained insights enable us to propose an analytic approximation for the STPR for both pristine and SOBPs as a function of penetration depth, which parametrically depend only on the initial energy and the residual range of the ion, respectively.Comment: 21 pages, 5 figures, fixed bug with figures in v

СОЗДАНИЕ ГРАДИЕНТНЫХ ПЛАЗМЕННЫХ ПОКРЫТИЙ НА ОСНОВЕ ДИОКСИДА ЦИРКОНИЯ, СТАБИЛИЗИРОВАННОГО ДИОКСИДОМ ИТТЕРБИЯ

The process has been investigated and technological parameters for spraying gradient plasma coatings on the basis of zirconium dioxide stabilized with ytterbium dioxide have been optimized in the paper.Проведены исследования процесса и оптимизированы технологические параметры напыления градиентных плазменных покрытий на основе диоксида циркония, стабилизированного диоксидом иттербия

Doping practices in international weightlifting: analysis of sanctioned athletes/support personnel from 2008 to 2019 and retesting of samples from the 2008 and 2012 Olympic Games.

Background The pervasiveness of doping and findings of anti-doping corruption threaten weightlifting's position at the 2024 Olympic Games. Analysing the practices of doping in weightlifters could identify patterns in doping that assist in future detection. Methods We analysed publicly available data on sanctioned athletes/support personnel from the International Weightlifting Federation between 2008 and 2019 and announced retrospective Anti-Doping Rule Violations (ADRVs) from the 2008 and 2012 Olympic Games. Results There were 565 sanctions between 2008 and 2019 of which 82% related to the detection of exogenous Anabolic Androgenic Steroid (AAS) metabolites and markers indicating endogenous AAS usage. The detection of exogenous AAS metabolites, markers of endogenous AAS usage and other substance metabolites varied by IWF Continental Federation (p ≤ 0.05) with Europe (74%, 11%, 15%) and Asia (70%, 15%, 15%) showing a higher detection of exogenous AAS compared to Pan America (37%, 30%, 33%) and Africa (50%, 17%, 33%). When looking at the 10 most detected substances, the nations with the highest number of sanctions (range 17-35) all had at least one overrepresented substance that accounted for 38-60% of all detected substances. The targeted re-analysis of samples from the 2008 and 2012 Olympic Games due to the discovery of long-term metabolites for exogenous AAS resulted in 61 weightlifters producing retrospective ADRVs. This includes 34 original medallists (9 gold, 10 silver and 15 bronze), the highest of any sport identified by Olympic Games sample re-testing. The exogenous AAS dehydrochloromethyltestosterone and stanozolol accounted for 83% of detected substances and were present in 95% of these samples. Conclusion Based on these findings of regional differences in doping practices, weightlifting would benefit from the targeted testing of certain regions and continuing investment in long-term sample storage as the sensitivity and specificity of detection continues to improve

Distribution and abundance of western gray whales off northeastern Sakhalin Island, Russia, 2001’003

In 2001’003, >60,000 km of aerial surveys and 7,700 km of vessel surveys were conducted during June to November when critically endangered Korean–Okhotsk or western gray whales (Eschrichtius robustus) were present off the northeast coast of Sakhalin Island, Russia. Results of surveys in all years indicated gray whales occurred in predominantly two areas, (1) adjacent to Piltun Bay, and (2) offshore from Chayvo Bay, hereafter referred to as the Piltun and offshore feeding areas. In the Piltun feeding area, the majority of whales were observed in waters shallower than 20 m and were distributed from several hundred meters to ∼ 5 km from the shoreline. In the offshore feeding area during all years, the distribution of gray whales extended from southwest to northeast in waters 30’5 m in depth. During all years, the distribution and abundance of whales changed in both the Piltun and offshore feeding areas, and both north–south and inshore–offshore movements were documented within and between feeding seasons. The discovery of a significant number of whales feeding in the offshore area each year was a substantial finding of this study and raises questions regarding western gray whale abundance and population levels, feeding behavior and ecology, and individual site-fidelity. Fluctuations in the number of whales observed within the Piltun and offshore feeding areas and few sightings outside of these two areas indicate that gray whales move between the Piltun and offshore feeding areas during their summer–fall feeding season. Seasonal shifts in the distribution and abundance of gray whales between and within both the Piltun and offshore feeding areas are thought, in part, to be a response to seasonal changes in the distribution and abundance of prey. However, the mechanism driving the movements of whales along the northeast coast of Sakhalin Island is likely very complex and influenced by a multitude of factors

Качество жизни у больных мультицентрическим раком молочной железы

One of the main issues in the treatment of multicentric breast cancer (BC) is to choose the type of surgery (paying attention to the tendency to reduce the volume of surgical interventions). Many studies have demonstrated an adverse effect of this form of BC on long‑term survival outcomes (increased risk of recurrence, decreased overall survival rates, etc.). However, none of the studies examined the effect of surgery extent on the quality of life of these patients.Objective. To assess the effect of the surgery type on the quality of life of patients with multicentric BC.Materials and methods. 190 patients were included in the study. The median follow‑up was 72 (7–116) months. Age ranged from 27 to 76 years. The majority of patients (150 women, 78.9 %) had luminal HER2‑negative tumors, while «aggressive» (HER2‑overexpressing, triple negative) subtypes were detected in 40 (21.1 %) of them. 134 patients underwent radical mastectomy (40 of which also had immediate breast reconstruction), 56 received breast‑conserving surgery. Statistically significant differences were not observed among stages III and I–II BC (p = 0.125). The quality of life was assessed with the use of EORTC QLQ-C30 and EORTC QLQ-BR23 scales at ≥ 12 months after performing surgical treatment.Results. The quality of life was assessed depending on the type of surgical intervention. The patients after breastconserving surgery and immediate breast reconstruction demonstrated a significant advantage, primarily in the general perception of one's own health (p &lt; 0.05) and emotional status (p &lt; 0.05). Also, there were no significant differences in quality of life between the groups of patients after breast‑ conserving surgery and immediate breast reconstruction.Conclusion. Due to the increase in the life expectancy of breast cancer patients, the issues of maintaining a high quality of life are becoming increasingly important. From this point of view, performing breast‑ conserving and reconstructive surgeries is preferable for patients with multicentric BC.Одним из основных вопросов в лечении мультицентрической формы рака молочной железы (РМЖ), является вопрос выбора объема операции, особенно на фоне тенденции уменьшения объемов хирургических вмешательств. Во многих исследованиях было продемонстрировано неблагоприятное влияние данной формы РМЖ на отдаленные результаты выживаемости (увеличение риска рецидива, снижение показателей общей выживаемости и т. д.). Однако ни в одном из исследований не рассматривался вопрос влияния объема хирургического вмешательства на качество жизни данных пациенток.Цель исследования. Оценка влияния объемов хирургического вмешательства на качество жизни у пациенток с мультицентрической формой роста РМЖ.Материалы и методы. В исследование было включено 190 пациенток. Медиана наблюдения составила 72 (7–116) месяца. Возраст варьировал от 27 до 76 лет. Большинство пациенток (150 человек, 78,9 %) имели люминальные HER2‑негативные опухоли, в то время как «агрессивные» (HER2‑гиперэкспрессирующие, тройные негативные) подтипы наблюдались у 40 (21,1 %) пациенток. Хирургическое лечение проведено 134 пациенткам в объеме радикальной мастэктомии (с реконструктивным этапом в 40 случаях), 56 получили органосохраняющее лечение. Различия в частоте встречаемости III и I–II стадий заболевания не имели статистической значимости (p = 0,125). Качество жизни пациенток оценивалось с помощью шкал EORTC QLQ ‑ C30 и EORTC QLQ ‑ BR23 через 12 и более месяцев после выполнения хирургического лечения.Результаты. Оценка качества жизни проводилась в зависимости от типа хирургического вмешательства. Выполнение органосохраняющего лечения и реконструктивных операций приводило к значительному преимуществу, в первую очередь с точки зрения общего восприятия собственного здоровья (p &lt; 0,05) и эмоционального состояния (p &lt; 0,05). Кроме того, не отмечалось достоверных различий в качестве жизни между группами пациенток с органосохраняющим лечением и мастэктомией в сочетании с реконструкцией.Заключение. Вследствие увеличения продолжительности жизни пациенток РМЖ, все более актуальными становятся вопросы поддержания высокого качества жизни. С этой точки зрения, выполнение органосохраняющих и реконструктивно ‑ пластических операций предпочтительно для пациенток с мультицентрическим ростом