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Introduction. Neoplastic microenvironment represents a frequently studied subject in numerous studies. Angiogenesis, as a part of it, is a prognostic factor and a therapeutic target in several neoplastic diseases. Cases presentation. We describe the angiogenetic process in a small series of extra gastrointestinal stromal tumours (EGISTs) and corelate it with the proliferation index. We retrospectively searched our institutions databases for EGIST cases. The resulting data were reviewed by two pathologists. Immunohistochemistry (IHC) was performed to highlight the vascular structure of the tumours and determine the proliferative index using ki67 staining. Subsequently, the whole slide scanned digital images were used to assess micro vessel density and vascular surface. Statistical analysis of measurements data yielded a negative correlation between the tumour proliferative index and vascular surface normalized to examined surface of the tumour (r=-0.5506 and p=0.0051). A correlation between micro vessel density and proliferative index of the tumour could not be established in our series (p =0.035). Conclusions. Highly proliferative EGISTs have a reduced micro vessel surface compared to low grade tumours, possibly due to a limited development rate of the angiogenesis during the tumours’ growth. Due to the rarity of this sarcoma, our study is limited by the small number of cases, as well as by the preanalytical procedures performed on the tissue that may alter the vascular area in different manners. Further studies on larger series are needed to confirm our results and to investigate other morphological parameters, to assess the utility of anti-angiogenic therapies.

Introduction. The most important histologic prognostic factors for melanoma remain depth of invasion and mitotic rate. In a digital era, precision (in terms of reproducibility and inter laboratories repeatability), as well as image evidence, are new qualitative parameters. The objective of the study was to evaluate in a retrospective analysis any significant difference among the Breslow digital assessments performed using two different immunohistochemical stains and the gold standard, hematoxylin eosin stain. Material and methods. We evaluated 130 primary cutaneous melanomas diagnosed in a two-year period (2016-2017) with known Breslow scale. Immunohistochemistry staining (SOX10 and Melan A) was perform followed by slide scanning. Aperio Imagescope and StataCorp software were used for data acquisition and statics. Results. No significantly statistic differences were recorded between groups in terms of Breslow values (p=0.98, Kruskal-Wallis test). Conclusions. All three stains perform similar in evaluating depth of invasion regardless of the method used to quantify it. The pathologist should consider using an accurate and precise method like a digital measurement technique for daily reports.

Failure modes of lunar boulders depend both on rheology and the erosion agents acting in the lunar surface environment. Here, we address the failure modes of lunar boulders and their variations at a quasi-global scale (60°N to S). We deploy a neural network and map a total of ∼130,000 fragmented boulders (width > ∼10 m) scattered across the lunar surface and visually identify a dozen different disintegration morphologies corresponding to different failure modes. Our findings suggest that before a boulder is catastrophically shattered by an impact, there is an internal weakening period with minor morphological evidence of damage at the rock scale at the resolution of the used imagery. We find that some of the rare pre-shattering morphologies (e.g., fractures) are equivalent to morphologies observed on asteroid Bennu, suggesting that these morphologies on the Moon and on asteroids are likely not diagnostic of their formation mechanism (e.g., meteoroid impact, thermal stresses). In addition, we identify new morphologies such as breccia boulders with an advection-like erosion style. We publicly release the produced fractured boulder catalog along with this paper.

Subject. The paper is devoted to the study of the gold-silver-palladium-platinum mineralization of the streaky systems in the sedimentary rocks associated within the Triassic carbonaceous silicites of the Taukhinsky and Samarkinsky terranes of the Sikhote-Alin. Materials and methods. In the process of investigations we studied the metamorphosed carbonaceous siliceous-clay rocks and systems of the mineralized fractures in the Triassic siliceous-clay and siliceous (including jaspers) rocks of Shirokopadninskaya, Vysokogorskaya and Gornaya areas, as well as in the sandstones (unclarified age) of Gornaya area. The samples for the analytical study were taken with the lump way. To estimate the content of precious metals in the rocks, cut by the systems of the mineralized fractures, we used the fire assay and atomic-absorption methods. The analyses of minerals (in polished sections) have been done using the JXA-5A and JXA8100 microanalysers. Results. The gold-silver-palladium-platinum mineralization in the siliceous and clay-siliceous rocks, as well as in the sandstones is restricted to the systems of the mineralized fractures and by many features are analogous to the precious-metal mineralization of the black-shale formations. It is represented by native forms, disordered solid solutions, and intermetallic compounds of different metals. The specificity of the Au-Ag-Pd-Pt mineralization is a wide distribution of copper gold, Ni-, Cu-, and Pbbearing gold, and Zn-bearing platinum. Native elements and intermetallic compounds, including those of precious metals, are not rarely associated with the organic matter testifying to the active participation of carbon and, probably, hydrogen that provided the high- and ultra-reduction character of the processes of mineral formation. Conclusions. The presence of the mineral forms of different maximum reduced metals is caused by the influence of the organic matter of the Triassic carbonaceous silicites. This consisted in the removal of the most volatile components, and first of all the poorly bound water and hydrocarbons from the carbonaceous rocks through the contact metamorphism related with the injection of the granitoid intrusions of Cretaceous plutonic and volcanoplutonic belts.

The paper discusses the similarity between dissipative generation and superradiance regimes for systems of excited quantum emitters placed in an open cavity. In the case of the existence of a resonator field due to reflections from the ends of the system, a dissipative generation regime is usually realized. In this case, the decrement of oscillations in the waveguide in the absence of radiators turns out to be greater than the increment of the arising instability of the system of radiators placed in the resonator. When describing this mode, the influence of the emitters on each other and the sum of their own fields is neglected. The resonator field forces the oscillators to emit or absorb quanta synchronously with it, depending on the local value of the population inversion. Lasing takes on a weakly oscillatory character due to an asynchronous change in the population inversion of the system of emitting dipoles (nutations), which have a ground and excited energy levels. To describe the process, the equations of the semiclassical theory based on the use of the density matrix are quite sufficient. In the case when there is no resonator or waveguide field, taking into account the eigenfields of the oscillators becomes essential. To simulate the superradiance process, large emitting particles are used, to describe which one should use the equations for the density matrix. It is shown that the interaction of quantum emitters in this case is due to electromagnetic fields under conditions when the overlap of their wave functions is insignificant. Equations are obtained that allow considering the process of interaction of emitters. When the emitters interact, an integral field is formed in the resonator, an increase in the intensity of which leads to synchronization of the emitters. It is shown that the characteristic times of the development of the process, as well as the attainable amplitudes of the excited fields for dissipative regimes of generation and regimes of superradiance of emitters filling an open resonator, are comparable.

Research on social processes in the production of scientific output suggests that the collective research agenda of a discipline is influenced by its structural features, such as "invisible colleges" or "groups of collaborators" as well as academic "stars" that are embedded in, or connect, these research groups. Based on an encompassing dataset that takes into account multiple publication types including journals and chapters in edited volumes, we analyze the complete co-authorship network of all 1,339 researchers in German political science. Through the use of consensus graph clustering techniques and descriptive centrality measures, we identify the ten largest research clusters, their research topics, and the most central researchers who act as bridges and connect these clusters. We also aggregate the findings at the level of research organizations and consider the inter-university co-authorship network. The findings indicate that German political science is structured by multiple overlapping research clusters with a dominance of the subfields of international relations, comparative politics and political sociology. A small set of well-connected universities takes leading roles in these informal research groups.

This scientific paper presents a role-based aspect of chatbots in the educational field, covering certain of their advantages and disadvantages. Future trends in their development are presented. The use and implementation of chatbots in an automated information system for process management in the educational field is discussed. [ABSTRACT FROM AUTHOR]

This paper presents an approach of Document Object Model database record management component user interface (UI) creation. Mainstream of UI development approaches concentrates in few directions, omitting holistic view on the fundamental database operations. The proposed solution uses method lay on of standard clauses adopted by the ECMA Script edition sixth and above. The program logic for the UI component was built with the intention - The existing functionality of such UI component to be extended and complemented. [ABSTRACT FROM AUTHOR]

Abstract Deltas are deposits directly accumulated by land‐generated gravity flows in a standing body of water. The paradigm of deltaic sedimentation has dramatically changed during recent years, from the popular very simplified ternary models of marine littoral deltas towards more realistic and comprehensive models, considering the importance of sediment‐laden river discharges. Ternary delta models were designed for clean rivers, where a stream flow drags the sediments. Depending on the basin dynamics, these littoral deposits can be modified, forming tidal‐dominated, wave‐dominated or fluvial‐dominated littoral deltas. In recent years, a new classification of delta systems was proposed, based on contrasting the salinity of the receiving water body with the bulk density of the incoming fluvial discharge. Rivers are highly dynamic systems, and their discharges can be very variable in terms of flow duration and sediment concentration. Additionally, the salinity of the receiving water body can exhibit significant variability, especially in closed lakes and epicontinental seas, ranging from freshwater to brines. This scenario allows the distinction of three major delta categories (hypopycnal, homopycnal and hyperpycnal deltas) which can be in turn subdivided, defining seven delta types. Hypopycnal deltas form when the bulk density of the incoming flow is lower than the density of the water in the basin, allowing the definition of three delta types, corresponding to hypersaline littoral deltas, marine littoral deltas and brackish littoral deltas. Homopycnal deltas form when the bulk density of the incoming flow is similar to the density of the water in the basin, defining a delta type termed homopycnal littoral deltas. Hyperpycnal deltas form when the bulk density of the incoming flow is higher than the density of the water in the basin, allowing the definition of three categories termed hyperpycnal littoral deltas, hyperpycnal subaqueous deltas and hyperpycnal fan deltas.