119 research outputs found
Figure 4 in Sperm ultrastructure in two species of Gyraulus (Gastropoda: Pulmonata: Planorbidae)
No full textFigure 4. Longitudinal (LS) and transverse (TS) transmission electron micrograph sections of spermatozoa of Gyraulus (Gyraulus) albus. (a) LS, sperm head at the final stage of maturation. (b, c) LS, internal structure of the acrosomal complex. (d) TS, acrosomal pedestal. (e) TS, basal portion of the nucleus with trapezoid coarse fibres. (f) TS, neck region with trapezoid coarse fibres and a single glycogen mass surrounded by a thin band of mitochondrial derivative. (g) TS, anterior midpiece with triangular coarse fibres and four glycogen helices enclosed within a mitochondrial derivative. (h) LS, posterior portion of the nucleus, neck region and anterior portion of the midpiece. (i) LS, middle portion of the midpiece showing four glycogen helices, mitochondrial derivative and axial complex. (j) TS, middle portion of the midpiece showing three glycogen helices, mitochondrial derivatives and axial complex. (k) TS, middle portion of the midpiece with two glycogen helices, mitochondrial derivative and axoneme. (l) TS, posterior midpiece with a single glycogen helix. (m) TS, posteriorPublished as part of Soldatenko, E.V., Shatrov, A.B. & Petrov, A.A., 2016, Sperm ultrastructure in two species of Gyraulus (Gastropoda: Pulmonata: Planorbidae), pp. 2985-3002 in Journal of Natural History 50 on page 2994, DOI: 10.1080/00222933.2016.1219781, http://zenodo.org/record/518985
Figure 3 in Sperm ultrastructure in two species of Gyraulus (Gastropoda: Pulmonata: Planorbidae)
No full textFigure 3. Longitudinal (LS) and transverse (TS) transmission electron micrograph sections of spermatozoa of Gyraulus (Armiger) crista. (a, b) LS, head of a spermatozoon at the final stage of maturation. (c) LS, internal structure of the acrosomal complex. (d) TS, middle portion of the nucleus. (e) TS, basal portion of the nucleus with trapezoid coarse fibres and a single glycogen mass surrounded by a thin band of mitochondrial derivative. (f) TS, neck region with triangular coarse fibres and four glycogen helices enclosed within the mitochondrial derivative. (g) LS, middle portion of the midpiece with three glycogen helices, mitochondrial derivative and axoneme. (h) TS, middle portion of the midpiece with two glycogen helices, mitochondrial derivative and axoneme. (i) TS, posterior portion of the midpiece with a single glycogen helix. (j) TS, portion of the midpiece without glycogen helices. (k, l) LS, annulus region showing a ring at the tip of the mitochondrial derivative (black arrows) and a cylinder at the anterior end of the glycogen piece (white arrows). (m) TS, glycogen region with the axoneme. (n) TS, axoneme in the tail region with a complete 9 + 2Published as part of Soldatenko, E.V., Shatrov, A.B. & Petrov, A.A., 2016, Sperm ultrastructure in two species of Gyraulus (Gastropoda: Pulmonata: Planorbidae), pp. 2985-3002 in Journal of Natural History 50 on page 2992, DOI: 10.1080/00222933.2016.1219781, http://zenodo.org/record/518985
Українська революція і проблема створення національного парламенту
Get PDFIn this article, based on the analysis of available documents and real historical facts was made an attempt to follow the approaches and practices of the political forces that sought to implement the concept of the Ukrainian national-democratic revolution, one of its core program requirements - the convening of a national parliament.First steps in the aforementioned direction were made during the time of the Central Rada, headed by M. Hrushevsky. Leading political coordination center, created on a democratic basis and, in the conviction of its leaders, called upon to bring the Ukrainian community into a national system, in the process of its development began to take on some of the functions inherent in the classical examples of the world, first of all European parliamentarism. Starting from the documents of the Ukrainian National Congress (April 6-8, 1917, Kiev), Ukrainian political parties, and the approval of the Constitution of the Ukrainian People's Republic (April 29, 1918), due to the convening of a parliamentary institution (the names were different - Ukrainian Constituent Assembly, The Constituent Council, the Ukrainian Sejm (Soim), the Legislative Duma, the Provisional Parliamentary Assembly, the Parliament, the National Assembly of Ukraine, etc.) the task of creating the People's Parliament was put forward as a political perspective. The same Central Rada, or its unchanging Chairman, or scholars of law, constitutionalists, guided by scientific criteria, are not inclined to qualify as a full-fledged National Parliament. And the initiated process of movement in a democratic way was the force interrupted by the coup on April 29, 1918.Upon coming to power, hetman P. Skoropadsky abolished the Constitution of the UPR with his first acts and banned the convening of the Constituent Assembly, which planned to convene the Central Rada.In times of Hetmanate temporality, extraordinary, transient impetus of authoritarian rule were proved in every way. Numerous public declarations promised to create a parliamentary institution (for 7,5 months of the official existence of the Ukrainian State, even its name was not tired) have in fact turned out to be an empty sound. But the real position of delaying the authorities to resolve the popular, urgent problem was rigorously co-ordinated with the Austro-German occupation administration, for which, as the true ruler of the situation in the country, the National Parliament seemed unclear, totally unnecessary rage.On the business ground, the Directory tried to implement of the idea of creating a national parliament. However, the general situation of 1919 - 1920 was overcomplicated. In particular, contradictions in the political direction of the revived Ukrainian People's Republic were significantly negative. For some time it was planned to delegate the role of the Parliament before the Labor Congress of Ukraine (January 23-29, 1919), but it did not become, according to the plan, a permanent institution. Practically performing certain parliamentary functions (for example, lawmaking activities), the Directory, like the Central Rada, planned to convene a full-fledged national parliament, eventually determined by the beginning of implementation of the judicial process (Act of Unification of the UNR and ZUNR on January 22, 1919). However, due to the difficult, first of all the military, situation which permanently deteriorated, the realization of democratic state-building plans did not happen.Thus, in spite of ideas, initiatives, plans, preparatory efforts and approved documents, the practice of fulfilling some of the functions inherent in the Parliament, such a genuine institution in the revolutionary era (1917-1920), was not created in Ukraine.На основі аналізу наявних документів, реальних історичних фактів відтворюється аспект досвіду діяльності політичних сил України в 1917–1920 рр., спрямованої на запровадження в державотворення демократичних засад (народоправства), реалізації одного з його найважливіших, популярніших гасел і вимог – скликання національного парламенту. Робиться висновок, що попри всі зусилля й бажання, здійснені окремі кроки, лідерам Української революції, як доби Центральної Ради, так і Директорії, домогтися здійснення стратегічного завдання з різних причин не судилос
The Determination of Feasible Control Variables for Geoengineering and Weather Modification Based on the Theory of Sensitivity in Dynamical Systems
No full textGeophysical cybernetics allows for exploring weather and climate modification (geoengineering) as an optimal control problem in which the Earth's climate system is considered as a control system and the role of controller is given to human operators. In mathematical models used in climate studies control actions that manipulate the weather and climate can be expressed via variations in model parameters that act as controls. In this paper, we propose the "instability-sensitivity" approach that allows for determining feasible control variables in geoengineering. The method is based on the sensitivity analysis of mathematical models that describe various types of natural instability phenomena. The applicability of this technique is illustrated by a model of atmospheric baroclinic instability since this physical mechanism plays a significant role in the general circulation of the atmosphere and, consequently, in climate formation. The growth rate of baroclinic unstable waves is taken as an indicator of control manipulations. The information obtained via calculated sensitivity coefficients is very beneficial for assessing the physical feasibility of methods of control of the large-scale atmospheric dynamics and for designing optimal control systems for climatic processes. It also provides insight into potential future changes in baroclinic waves, as a result of a changing climate
The Determination of Feasible Control Variables for Geoengineering and Weather Modification Based on the Theory of Sensitivity in Dynamical Systems
Get PDFGeophysical cybernetics allows for exploring weather and climate modification (geoengineering) as an optimal control problem in which the Earth’s climate system is considered as a control system and the role of controller is given to human operators. In mathematical models used in climate studies control actions that manipulate the weather and climate can be expressed via variations in model parameters that act as controls. In this paper, we propose the “instability-sensitivity” approach that allows for determining feasible control variables in geoengineering. The method is based on the sensitivity analysis of mathematical models that describe various types of natural instability phenomena. The applicability of this technique is illustrated by a model of atmospheric baroclinic instability since this physical mechanism plays a significant role in the general circulation of the atmosphere and, consequently, in climate formation. The growth rate of baroclinic unstable waves is taken as an indicator of control manipulations. The information obtained via calculated sensitivity coefficients is very beneficial for assessing the physical feasibility of methods of control of the large-scale atmospheric dynamics and for designing optimal control systems for climatic processes. It also provides insight into potential future changes in baroclinic waves, as a result of a changing climate
Model for Estimating the Transient Response of the Global Mean Surface Temperature to Changes in the Concentrations of Atmospheric Aerosols and Radiatively Active Gases
No full textConditions on the Bedrock and Surface of the Vavilov Ice Cap (Severnaya Zemlya) During its Surge According To Airborne Radar Data
No full textThe glacier surge at Vavilov Ice Cap, Severnaya Zemlya, Russia (79°18′ N, 94°40′ E) began as early as the mid-1960s with a slow advance of its margin in the western part. Since 2012, the advance switched to the phase of catastrophic movement, which reached its climax in 2016, when the glacier velocity reached 9.2 km a‒1. An ice fan with an area of about 140 km2 advanced into the Kara Sea water area 11 km from the shore, and a strongly crevassed ice stream was formed in the ice cap itself, which continues to move now with speeds of about 2 km a‒1. The dynamic instability of Vavilov Ice Cap can be triggered by changes in basal conditions, which are still poorly known. In this study, we used airborne radio-echo sounding data acquired in September 2014 over the ice cap to characterize its surface and bedrock conditions. Based on the delay time and reflection amplitudes, the power reflection coefficient (PRC) from glacier surface and bedrock was estimated. For its calibration, we used the amplitude of reflections from the sea surface registered from different altitudes. The bedrock PRC values were converted to dielectric permittivity and compared with the glacier surface velocities in 2014 obtained from Landsat-7 images. We found a high positive correlation between the bedrock PRCs and velocities in the area with glacier speed higher than 1000 m a-1. In this area, the PRC is 20 dB higher than in the neighboring slower moving areas. Such a difference may be because the ice stream advanced on marine loose sediments with higher dielectric permittivity and conductivity and a higher reflection coefficient. The range of estimated bedrock PRCs corresponds to bed materials with relative dielectric permittivity from 5 to 10 and electrical conductivity from 10–5 to 10–2 Sm m‒1
Predictive validity of the model for calculating of echocardiographic parameters in healthy patients
Get PDFAim. Development of a model for calculating of predicted values of key echocardiography (EchoCG) parameters in patients of different ages and staturelweight values.Material and methods. The study included 10604 apparently healthy patients aged from 1 day to 65 years; 5726 (54%) of them are female. In addition to the general clinical study, all patients underwent EchoCG with the measurement of standard indicators as recommended by the American Society of Echocardiography. We measured body surface area (BSA) and selected a regression model, which most adequately links the values of the EchoCG parameters and staturel-weight values.Results. All EchoCG parameters showed a significant correlation with BSA. The patients were divided into four groups to receive more homogeneous cohorts. We have identified newborns and adults. A group of children was additionally divided according to BSA, by less than 0,3 m2 and more than 0,3 m2. The calculated regression equations were reliable in both cases — before and after separation. Comparison of dispersion excesses showed a better dependence among the separated groups. The separation also significantly increased the prediction accuracy.Conclusion. The proposed mathematical models relevantly predict the normal values of variables. The method is well suited for calculating the Z-index of main EchoCG parameters
The 100th anniversary of the Federal Scientific Vegetable Center, the leader of Russian scientific vegetable growing
Get PDFThis year, the staff of the Federal Scientific Vegetable Center (FSVC) celebrates their 100th anniversary. Prof. S. I. Zhegalov was the recognized founder of the institution, which was reorganized from Gribovo Vegetable Experimental Station. Its team started with 14 employees, and the experimental crop area was slightly less than 4 hectares. In a short period of time (1920 to 1927), 74 cultivars of the most popular vegetable crops and a number of flower crop varieties were developed and improved. The second period of the Station’s development (1937 to 1966) was associated with the name of Acad. E. I. Ushakova. During this period, a pleiad of talented scientific plant breeders emerged and thrived: A. V. Alpatyev, S. P. Agapova, E. M. Popova, A. D. Plinka, Yu. A. Kobyakova, and others. In 1971, Gribovo Experimental Station was transformed into the All-Union Scientific Research Institute for Breeding and Seed Production of Vegetable Crops (VNIISSOK). The Institute was headed by Acad. P. F. Sokol. Under his leadership, capacity building and logistic support of the Institute were promoted: new facilities were built, and the experimental production network was expanded. Despite the difficulties associated with the reorganization and the financial and political situation in the country in 1992–2017, the staff achieved significant results during the years of the directorship by Acad. V. F. Pivovarov. New cultivars were developed to meet the demand; they occupied more than 50% of the crop area under vegetables across the country. Each year, the Institute produced 200–300 tons of elite and cultivar seeds. In 2017, the Institute was merged into the Federal Scientific Vege table Center as the keystone element. The Center also incorporated the All-Russian Research Institute of Vegetable Production and seven experiment stations throughout the Russian Federation. The Institute has been successfully cooperating with the N.I. Vavilov Institute of Plant Genetic Resources (VIR) for many years, exchanging germplasm materials and experience, and jointly developing vegetable cultivars
Increasing the competitiveness of vegetable crops to weeds by improving control methods
Get PDFWeeds are a major threat in crop production, and controlling them in modern agriculture is critical to preventing crop losses and ensuring food security. Intensive farming practices, climate change and natural disasters affect weed dynamics, requiring a change in management practices. Existing methods are no longer viable due to lack of manpower; chemical control methods are limited by health hazards and the development of herbicide resistance in weeds. This article discusses some potential alternative weed control strategies in modern vegetable production that are feasible and effective. Increasing the competitiveness of vegetable crops through proper planning of agrotechnologies system, preventive, cultural and mechanical methods, development of competitive varieties, allelopathy, biological control and reduction of weed seed production at harvest will be a major aspect in sustainable weed management. Improving tillage regimes has long been considered the main measure of weed control. Control of weed seed production and weed injuriousness have been shown as potential tools to reduce weed seed germination and retention in the soil. The development of allelopathy has led to the emergence of new methods of weed control. The use of the allelopathic potential of crops also deserves mention in modern weed control methods. Thermal weed control is seen as a useful method. The role of bioherbicides as an integral part of sustainable weed management is emphasized. All of these strategies are viable for modern agriculture; however, choosing a specific method and using the right combinations will be the key to success. No strategy is perfect, and therefore an integrated approach can provide the best results. The adoption of such practices can improve the efficiency of farming systems in sustainable agricul- ture. A comprehensive method for protecting vegetable crops from weeds and ways to reduce the potential contamination of fields with seeds and weed seedlings are described. The optimal norms and technological features, conditions for the effective use of modern herbicides on crops and plantings of vegetable crops are given
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