Rigid Scheme Research Articles

ICTSurF: Implicit Continuous-Time Survival Functions with neural networks

Background and objective:Recently, the rise of models based on deep neural networks (DNNs) has demonstrated enhanced effectiveness in survival analysis. However, deep learning dealing with survival analysis usually required specific architecture or strict discretization scheme limiting the temporal precision of input and output values. Methods:This research introduces the Implicit Continuous-Time Survival Function (ICTSurF), built on a continuous-time survival model, and constructs survival distribution through implicit representation. As a result, our method is capable of accepting inputs in continuous-time space and producing survival probabilities in continuous-time space, independent of neural network architecture. Results:Comparative evaluations against existing methods underscore the remarkable competitiveness of our proposed approach. Furthermore, we highlight the advantages of a flexible discretization scheme, showing improved performance with a lower number of discretizations compared to a rigid scheme. Conclusion:Our model exhibits competitive performance compared to existing methods, enhancing the flexibility of input data.

Mój Uniwersytet

I have been asked to give a thought on the University. It is arranged in a sequence of “past – yesterday – today”, to which I will occasionally refer. It will not, however, constitute a rigid scheme governing this talk. The inspiration for these thoughts was specified by the question “what perception of the University I imbibed in my family home, how I later confronted this with my own practice or «experience» of the University, how I look at it from the perspective of the experience I have had and from observing the changes taking place.”

Design of High-Frequency Carbon Nanotube-Carbon Nanotorus Oscillators for Energy Harvesting: A Molecular Dynamics Study.

The objective of this study is to examine the feasibility of using carbon-based nanostructures as nano-oscillators for future nanoelectromechanical applications such as energy harvesting devices and vibration sensing. The proposed nano-oscillator is comprised of a carbon nanotube (CNT) oscillating through a fixed carbon nanotorus molecule. For the first time in the literature, molecular dynamics (MD) simulations in conjunction with the Tersoff-Brenner (TB) and 6-12 Lennard-Jones (LJ) potential functions are adopted to determine the molecular interactions of the introduced nanodevice. To simulate the oscillatory behavior, two different schemes, namely, rigid and flexible, are considered. A detailed parametric study is performed to investigate the effects of rigidity, flexibility, and size of nanostructures as well as initial velocity on the force distribution and time histories of displacement and velocity of the core. Numerical results reveal that unlike the rigid oscillators, the flexible oscillators damp out within a few cycles. It is shown that the escape velocity of the flexible scheme is ∼6 times greater than that of the rigid scheme. The operating frequency and the generated power of rigid and flexible schemes under different system parameters are also calculated and compared. It is demonstrated that with increasing the ratio of nanotube-to-nanotorus diameter, the operating frequencies of both schemes decrease, while the generated powers do not behave monotonically. For a determined system parameter, it is observed that the flexible scheme provides higher operating frequencies compared to the rigid one. Moreover, considering that the initial velocity of the system is identical to the escape velocity, the generated power of the flexible scheme is calculated to be ∼14 times greater than that of the rigid scheme.

Whatever You Bestow on Him, You Will Bestow on Me: Key Motifs of Early Byzantine Letters of Recommendation

The letter of recommendation was known in Antiquity as a separate genre of letter writing for which a certain set of compositional techniques and formulae were developed. In Byzantium, too, the letter of recommendation was in great demand: letters in which the author presents his protégé to the addressee and, as a rule, asks him to perform something for him are not difficult to find in the epistolary collections of many authors from the 4th to the 15th century. Meanwhile, while the ancient letter of recommendation is well studied, the etiquette of this genre in the Byzantine tradition has hardly been investigated yet. The purpose of this piece is to characterize the etiquette norms of Greek letter of recommendation in the early Byzantine period (4th — early 7th centuries). The subject of the study are, first of all, literarische Privatbriefe, belonging to Libanius, Basil the Great, Gregory of Nazianzus, John Chrysostom, Synesius of Cyrene, Theodoret of Cyrrhus, Procopius of Gaza and others, but also private papyrus letters. Their analysis leads to the conclusion that there is a wide variability of the canons of the letter of recommendation, the absence of any rigid scheme that presupposes a clear sequence of structural elements. At the same time, it reveals six recurrent etiquette motifs, all of which are subordinated to a single goal — to persuade the addressee to patronize the recommended person. These motifs are analyzed in detail, and stable formulas are indicated for some of them. An attempt is made to determine to what extent the canons of Greek letters of recommendation of the 4th–7th centuries go back to the ancient tradition. The letters of recommendation of Cicero and Pliny the Younger, as well as letters preserved on late antique papyri, are used as material for comparative analysis.

Protection against progressive collapse of buildings with precast reinforced concrete floors

Introduction. The results of the studies analysis on the protection of multi-storey buildings from progressive collapse are presented, which indicates insufficient attention to structural systems made of precast reinforced concrete, as a result of which design standards orient the designer to the use of not always effective monolithic structures. In particular, the problem of protection against progressive collapse with the exclusion of prefabricated crossbars of floors and coatings has not been practically studied. The purpose of the study is to develop a method for calculating a continuous system of hollow plates made by the method of formless molding.Materials and methods. When designing the protection of multi-storey buildings from prefabricated elements, a static calculation is usually carried out with the exception of vertical structures (walls, columns) and the reinforcement of floor crossbars and coatings by ensuring their continuity. There are constructive methods of reinforcing prefabricated floors by creating continuous plates of adjacent spans with the help of connecting elements made of plastic reinforcing steel, but the calculation of such systems has not been developed. A method for calculating a system of two plates according to a rigid thread scheme is proposed.Conclusions. Currently, theoretical methods have been developed to solve various problems of protecting buildings and structures from progressive collapse. However, there are many design requirements for the protection of multistorey buildings from progressive collapse, which have not yet received experimental and theoretical confirmation for the effective solution of practical problems. It seems that in this article one of these problems is partially solved.

Two Year Study of Aflibercept and Ranibizumab Intravitreal Therapy in Patients with Wet AMD.

Background and objectives: The aim of this study was to evaluate the therapeutic results in patients with exudative AMD treated with ranibizumab and aflibercept intravitreal injections over a two-year observation period. Materials and methods: A retrospective observational study was conducted in a clinical hospital on a group of patients who randomly qualified for treatment with Aflibercept (group A) and Ranibizumab (group B) as part of the Polish National Health Fund Medical Program for exudative AMD. Group A consisted of 90 patients, and group B contained 54 patients. The choice of drug in a patient depended solely on the availability of the medication at the time. Before each injection, best corrected visual acuity (BCVA) on the ETDRS scale and central retinal thickness (CRT) were assessed using optical coherence tomography (OCT). Patients from both groups were treated in the first year of treatment with a rigid scheme of 3 doses of 2.0 mg Aflibercept (group A) and 0.5 mg Ranibizumab (group B) at monthly intervals, followed by 4 doses at bimonthly intervals. In the second year, a “pro re nata” scheme was applied. The aim was to evaluate changes in BCVA and CRT after three injections, after 7 injections (about 12 months), and after the second year of therapy (24 months) with reference to the baseline and to compare the effectiveness of the medications. The influences of the following factors were studied: age, gender, initial BCVA, and initial CRT, as well as the number of injections received. Results: No significant statistical differences were found between patients receiving Aflibercept and Ranibizumab therapy in terms of achieving improved visual acuity and reducing retinal thickness after two years of therapy. Conclusions: Both aflibercept and ranibizumab were found to be effective for treating exudative AMD.

Evaluation of Early Treatment Response Utilizing the MAS-ALL18 Adapted Management Guideline in Four “Mexico in Alliance with St. Jude” (MAS) Member Hospitals

Introduction: Acute lymphoblastic leukemia (ALL) represents approximately 50% of all childhood cancers in Latin America. Mexico is not the exception. The impact of ALL survival on overall childhood cancer survival is significant. According to government data, five-year survival is about 52%. Mexico in Alliance with St. Jude (MAS) is a multi-site, intersectoral collaboration. The collaborative network has explored and reported on factors associated with this suboptimal outcome and have identified challenges with ALL risk group classification as a leading cause. For example, as many as 82% of children diagnosed with ALL in Mexico receive high-risk treatment and the tendency for higher-risk group assignment often occurs in response to limited access to cytogenetic testing and minimal residual disease (MRD) testing. This leads to higher intensity treatment and may explain the high rate of treatment-related death (TRD) (12%) documented during the induction but also subsequently. In our previous case series, only 75% of patients were alive at the end of the first year of treatment. These findings, led MAS to develop a consensus-derived standardized diagnosis and treatment schema (MAS-ALL18), which takes into account clinical, cytogenetic, and MRD results. Diagnostic testing is performed in a centralized laboratory. Although centred on delivery of standard of care, this experience represents is the first prospective multi-site cooperative group effort in Mexico. We report on early treatment (first 90 days) clinical and implementation outcomes utilizing the MAS-ALL18 adapted management guideline (AMG) in four member hospitals of the MAS collaboration network.Results: From June 2019 to June 2020, 137 patients received treatment utilizing the MAS-ALL18 AMG in four publicly funded hospitals in Mexico. B-cell ALL represented 91.9% of the cases, 20.4% of patients were older than 9 years of age, 25.5% had a white blood cell count greater than 50,000 at diagnosis and 58.3% were male. Complete remission at the end of the induction was achieved in 90.6% of patients. TRD during the induction phase was 8%. MRD at Day 15 in 123 patients with B-cell ALL, 84.5% of them had MRD <1% and 7.3% had MRD ≥5%. MRD at Day 29 was assessed for the 10 patients diagnosed with T-cell ALL, 4 patients had MRD <0.01%, 2 had 0.02%, and 4 died during the induction phase. MRD was also assessed during consolidation (at Day 84) in 99 patients, 94.9% had MRD <0.01% and 5 patients MRD ≥0.01%, from which 3 had MRD at day 15 >1% and none registered an MRD result <0.5%. Utilizing the MAS-ALL18 risk group stratification, 50% of patients were assigned to a favorable risk group at the end of the consolidation. In 34 patients, the risk group was reclassified following the standardized algorithm; 30 reclassification events happened at the end of the induction and four at the end of the consolidation. Only two events were reassigned to a lower risk group, while the rest of the reclassifications were conducted to assign patients to a higher risk group due to unfavorable cytogenetics or an inadequate early response to treatment. High-risk treatment was ultimately assigned to 30% of patients using the MAS-ALL18 risk classification schema.Conclusion: It is feasible to implement a standardized multi-site adapted management guideline for ALL risk group stratification and treatment allocation in Mexico in the context of a collaborative network. TRD remains high during the induction phase, nevertheless, this number shows an improvement (8%) compared to the 2015 data report (12%). The ALL risk group classification is transitioning from a rigid scheme that placed 80% of patients in a high-risk group to a dynamic classification system that considers cytogenetic testing and MRD conducted in a centralized and externally validated laboratory that serves as reference for all the participating hospitals. The standardized MAS-ALL18 approach allowed us to classify 50% of patients in a favorable risk group during and at the end of the induction phase, which implies receiving a lower intensity treatment with a high probability of cure and a lower risk of TRD. The implementation of MAS-ALL18 risk classification scheme reduced the number of children requiring high-risk treatment in the participating hospitals. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Research horizontally loaded pyramidal piles with compacted bottom and their calculation

The results of experimental and theoretical research in work features of a rammed pyramidal pile with compacted bottom for horizontal load in clayey soils are presented. The experimental cast-in situ pyramidal piles with compacted bottom were made at 2 experimental sites, composed of clayey soils. Static horizontal load tests were carried out. At each stage of loading, horizontal displacements were measured at the load application level and at a height of one meter from the top edge of the pile. The “horizontal load - pile head displacement” dependencies were obtained. It was found that the rotation of the pile in the soil occurs without bending, i.e. according to a rigid scheme, and also that compacted bottom prevents horizontal displacement of the pile bottom. Based on the analysis of the results of static tests of piles, a design scheme has been created, in which the pile is considered as a rigid rod buried in a multilayer linearly deformable base with a point of zero displacements at the lower end of the pile. In accordance with the design scheme, an analytical method for calculating a pyramidal pile with compacted bottom for horizontal load and bending moment has been developed. The calculation method allows to determine the horizontal displacement of the pile head in any section along the depth, the angle of rotation of the pile, bending moment and shear force along the length of the pile.

СИСТЕМНЫЙ АНАЛИЗ КАК ИННОВАЦИОННЫЙ ИНСТРУМЕНТ РАЗВИТИЯ МЕХАНИЗМОВ ПРИНЯТИЯ РЕШЕНИЙ В СОВРЕМЕННОМ МЕНЕДЖМЕНТЕ И УПРАВЛЕНИИ

Modern systems analysis and management is a whole complex of activities based on a system of ideas, methods and models of effective organization management. Modern management does not have exact recipes for correct decisions, cannot be based on rigid management schemes, because the modern management system is rather a "philosophy of management activity" – a kind of system of views and methods of research, cognition of economic phenomena, solving management problems, achieving strategic goals. Such a set of measures is called a complex control system. Each system, regardless of the scale and number of its constituent elements, is subject to changes, and any change requires research and the adoption of an appropriate management decision. Decision making in these types of complex systems is carried out by a technical device or a person and is based on the comparison and assessment of options for action. The study of decisionmaking procedures and the proper organization of the system is an urgent problem in the creation and operation of complex systems. Making such decisions is impossible without a systematic analysis. This circumstance determines the relevance of this article.

6 voces en 10 minutos: Educación: clave para lograr metas terapéuticas

6 voces en 10 minutos: Experiencias en educación en ArgentinaEducación: clave para lograr metas terapéuticasAprendemos medicina mediante esquemas que nos facilitan la adquisición de conocimientos y su ordenamiento mnemotécnico. Pero entre ese esquema rígido y el paciente que tenemos enfrente, existen otros elementos como afectos, creencias, hábitos alimentarios, confort y otros que determinan la eficacia del proceso educativo. Al recibir el diagnóstico de diabetes, el paciente experimenta un impacto que le genera una serie de interrogantes, y seguramente ansiedad y angustia. Reconocer y comprender estas situaciones ciertamente generarán una empatía que facilitará no sólo transmitir conocimientos sobre su enfermedad, sino transformarlo en un activo y efectivo participante en el control y tratamiento de la misma. Ello implica cambiar el paradigma de la atención clásica por un modelo interactivo, donde el médico explica el problema, el paciente lo entiende y juntos acuerdan el tratamiento apropiado. Promovemos la importancia de la educación terapéutica mostrando resultados obtenidos en programas estructurados e interactivos como el PEDNID-LA, en el cual variables clínicas (peso y presión arterial), metabólicas (glucemia, HbA1c y perfil lipídico) y económicas (costo de medicación) disminuyeron significativamente en el año post curso. Destacamos también la importancia al comparar cuartilos de valores probando que, cuanto más alto fuera el valor inicial del indicador, mayor sería la disminución obtenida e, igualmente, la importancia de la empatía paciente-educador lograda para optimizar resultados inducidos por la educación.

A comprehensive DFT study on the thermodynamic and mechanical properties of L12-Al3Ti/Al interface

In this present work, we systematically studied the properties of metastable Al3Ti/Al (L12-Al3Ti/Al) low-index coherent interface, including structure stability, fracture behavior, plasticity, stacking fault energy, electron structure, and density of states by first-principles calculation. The results of the rigid scheme indicated that the strongest interfaces of L12-Al3Ti(001)/Al(001), L12-Al3Ti(110)/Al(110), and L12-Al3Ti(111)/Al(111) were stacked similarly to bulk L12-Al3Ti or Al, and the work of adhesion (Wad) of 2.78, 2.81, and 1.83 J/m2, respectively. In the rigid scheme, the theoretical tensile strength for L12-Al3Ti(001)/Al(001), L12-Al3Ti(110)/Al(110), and L12-Al3Ti(111)/Al(111) interfaces were 15.30, 14.23 and 12.39Gpa, respectively. We simulated the fracture behavior by the full-relaxed scheme, and tensile stresses are 10.65, 10.10, and 8.27 GPa for L12-Al3Ti(001)/Al(001), L12-Al3Ti(110)/Al(110), and L12-Al3Ti(111)/Al(111) interfaces, respectively. Furthermore, our findings revealed that the interfaces were prone to break on the Al side in the full-relaxed stretching scheme, which was closer to reality. Moreover, the partial density of states (PDOS) indicated that s-p-d hybridization orbitals formed among the Al and Ti atoms. Finally, unstable stacking fault energy and Rice ratio indicated that the L12-Al3Ti(001)/Al(001), L12-Al3Ti(110)/Al(110) interfaces had good plasticity to some extent. However, it can start slipping in <11-2> direction with D = 3.02 and turn into another direction after μ/b = 0.11.

Limitations of Predicting Substrate Classes on a Sedimentary Complex but Morphologically Simple Seabed

The ocean floor, its species and habitats are under pressure from various human activities. Marine spatial planning and nature conservation aim to address these threats but require sufficiently detailed and accurate maps of the distribution of seabed substrates and habitats. Benthic habitat mapping has markedly evolved as a discipline over the last decade, but important challenges remain. To test the adequacy of current data products and classification approaches, we carried out a comparative study based on a common dataset of multibeam echosounder bathymetry and backscatter data, supplemented with groundtruth observations. The task was to predict the spatial distribution of five substrate classes (coarse sediments, mixed sediments, mud, sand, and rock) in a highly heterogeneous area of the south-western continental shelf of the United Kingdom. Five different supervised classification methods were employed, and their accuracy estimated with a set of samples that were withheld. We found that all methods achieved overall accuracies of around 50%. Errors of commission and omission were acceptable for rocky substrates, but high for all sediment types. We predominantly attribute the low map accuracy regardless of mapping approach to inadequacies of the selected classification system, which is required to fit gradually changing substrate types into a rigid scheme, low discriminatory power of the available predictors, and high spatial complexity of the site relative to the positioning accuracy of the groundtruth equipment. Some of these issues might be alleviated by creating an ensemble map that aggregates the individual outputs into one map showing the modal substrate class and its associated confidence or by adopting a quantitative approach that models the spatial distribution of sediment fractions. We conclude that further incremental improvements to the collection, processing and analysis of remote sensing and sample data are required to improve map accuracy. To assess the progress in benthic habitat mapping we propose the creation of benchmark datasets.

A comprehensive study of the L12-Al3Nb/Al interface properties using first-principles calculations

In this study, properties of low-index L12-Al3Nb/Al such as structure stability, thermodynamic, strength, electron properties, unstable stacking fault energy, plasticity, and fracture behavior of interface (L12-Al3Nb(001)/Al(001), L12-Al3Nb(110)/Al(110), and L12-Al3Nb(111)/Al(111)) were systematically studied. The results showed that the structure of the strongest interfaces of L12-Al3Nb(001)/Al(001), L12-Al3Nb(110)/Al(110), and L12-Al3Nb(111)/Al(111) were stacked similar to bulk L12-Al3Nb or Al, with maximum work of adhesion of 2.80 J/m2, 2.99 J/m2, and 1.74 J/m2, respectively. The maximum computed theoretical tensile strength of L12-Al3Nb (001)/Al(001), L12-Al3Nb (110)/Al(110), and L12-Al3Nb (111)/Al(111) interfaces were 18.71 GPa, 16.85 and 11.88Gpa respectively, for the rigid scheme; and 8.91 GPa, 8.52 GPa and 6.98 GPa respectively, for the full-relaxed scheme. Meanwhile, the interfaces were virtually prone to break on the Al side on full-relaxed stretching. Moreover, the partial density of states of the interface indicated that hybridization occurs among the Al-s, Al-p, Nb-s, Nb-p, and Nb-d orbitals, forming s-p-d hybrid orbital. Finally, based on the unstable stacking fault energy and Rice ratio, the interfaces have high plasticity once subjected to shear stress in the <100 > , <110 > , <-110 > , or <11−2> directions, which elucidate the interface properties and understand the underlying mechanism between L12-Al3Nb and Al alloys, thereby provide vital information to guide designing of novel Al alloys.

A systematic study of interface properties for L12-Al3Sc/Al based on the first-principles calculation

In current work, we used the first-principles to describe the structure stability, thermodynamic, strength, and electron properties, as well as unstable stacking fault energy, plasticity, and fracture behavior of low-index coherent interfaces (L12-Al3Sc(001)/Al(001), L12-Al3Sc(110)/Al(110), and L12-Al3Sc(111)/Al(111)). Results showed that the structure of the strongest interfaces of L12-Al3Sc(001)/Al(001), L12-Al3Sc(110)/Al(110), and L12-Al3Sc(111)/Al(111) were stacked similarly to bulk L12-Al3Sc or Al, as evidenced by the adhesion work (Wad) of 2.32, 2.53, and 1.91 J/m2, respectively. The calculated tensile stress in the rigid scheme is 15.30, 14.23, and 12.39 Gpa for L12-Al3Sc(001)/Al(001), L12-Al3Sc(110)/Al(110), and L12-Al3Sc(111)/Al(111) interfaces, respectively, whereas the corresponding tensile stress in the full-relaxed scheme is 10.65, 10.10 and 8.27 GPa, respectively. Furthermore, our findings revealed that the interfaces were prone to breaking on the Al side in the full-relaxed scheme, which is closer to reality. Moreover, the analysis of the partial density of states (PDOS) revealed the presence of s-p-d hybridization orbitals among the interfacial atoms. Finally, unstable stacking fault energy and Rice ratio indicated that the interfaces are plastic when subjected to shear stress in 〈100〉, 〈110〉, 〈−110〉, or 〈11−2〉 directions.

Experiencia y hallazgos en el manejo de la dieta cetogénica en niños con epilepsia refractaria, estudio de 10 casos

Refractory epilepsy is due to that drug-resistant epilepsy in which there is no improvement after the applica-tion of various antiepileptic drugs (AEDs). The Telethon Children's Rehabilitation Center cares for a large population of children with some type of epilepsy. Recently, the application of the home intervention proto-col for the ketogenic diet (DC) has increased. A few years ago, DC was only attended with extreme surveil-lance in a hospital center under rigid schemes. With this background, the objective of this study was to describe the experience and findings of a series of 10 cases of children with refractory epilepsy treated with this DC protocol over the course of at least 1 year. All the cases of children (n = 10) attended at the Telethon Children's Rehabilitation Center, Aguascalientes, Mexico, who were treated with the ketogenic diet between the dates of February 2010 and June 2015, were reviewed by means of an electronic clinical record criteria for refractory epilepsy, as well as surveillance for pediatric neurology and nutrition. The DC home interven-tion protocol was established under the criteria of Lambruschini-Nilo & Gutierrez-Sanchez, where it started with a classic type DC with a 2: 1 ratio during the first week of adaptation and then went on to the 3: 1 or 4 ratio: 1 corresponding according to patient tolerance. The reduction in the number of crises was measured at 3 months and one year after surgery. A one-way ANOVA general linear model with repeated measures was applied to measure the efficacy at 3 months and one year of treatment, finding statistical significance when comparing the results means of the number of epileptic events before the diet (p = <0.006). . The most frequent type of epilepsy was West Syndrome in 4 patients, Lennox Gastaut Syndrome in 3 patients, Severe Myoclonic Epilepsy of Childhood and other types of epilepsy, 3 patients. The most common side effects were constipation in 60% of the population, and the least common were hypoalphalipoproteinemia-like dyslipidemia in 30%, reflux in 20%, and kidney stones in 10%.

THE PECULIARITIES OF SETTING THE GRINDING COEFFICIENT IN THE PROCESSING OF POLYCRYSTALLINE SUPERHARD MATERIALS

The questions related to the peculiarities of determining such a physical characteristic of the process of grinding polycrystalline superhard materials by diamond circles on metal and organic bonds as a coefficient of grinding are considered. It is the ratio of the tangential and normal components of the cutting force when grinding. It is proposed to determine it using the effective component of the tangential component of the cutting force. Its establishment is based on the use of the phenomenon of adaptation of the grinding process in general and its individual component, the periodicity of change in time of physical and technological indicators of processing in particular. The physical nature of the occurrence of the periodicity with respect to the conditions of the controlled grinding process according to the elastic scheme and to the conditions of the process of grinding polycrystalline superhard materials diamond circles on organic bonds in the self-sharpening mode is disclosed. It was established that when using the first process as a factor of forced influence on the state of the cutting surface of a circle it is necessary to choose the magnitude of intensity of electrophysical solution of the metal ligament of the diamond circle, and in the second transverse supply to the depth of processing. Recommendations regarding the choice of factors of forced influence are given. It is shown, that the peculiarity of the elastic treatment scheme is that the normal component of the cutting force is constant in time. Therefore, the change (increase or decrease) of the effective component of the tangential component of the grinding force leads to similar changes in the grinding coefficient and can clearly judge the effectiveness of the method or conditions of grinding that explores. In contrast to the elastic circuit grinding when working on a rigid scheme, both components (tangential and normal) grinding force, which are used to define the grinding coefficient, depend on the processing conditions. This fact should be considered when analyzing the obtained experimental data. In the future, research results will help to improve the grinding processes of polycrystalline superhard materials.

Diagnostic value of apparent diffusion coefficient lesion texture biomarkers in breast MRI

Quantitative assessment of breast intra-lesion heterogeneity in terms of contrast agent free Magnetic Resonance Imaging (MRI) approaches hold potential in breast cancer diagnosis. This study focuses on an Apparent Diffusion Coefficient (ADC) based approach, investigating the diagnostic role of 1st and 2nd order ADC statistics features, in differentiating benign from malignant breast lesion status. A total of 67 patients with 78 histologically verified breast lesions (40 benign and 38 malignant) was analyzed. ADC maps were generated for a slice representative of lesion largest diameter, considering intra Diffusion Weighted Imaging (DWI) sequence non rigid registration scheme. Lesion segments were defined by semi-automated Fuzzy C-Means (FCM) segmentation on high b-value diffusion images and propagated on ADC maps. 27 (11 1st order statistics and 16 2nd order statistics (texture) features were derived. To avoid overfitting a stepwise feature selection method was employed, while the discriminating ability of features was evaluated with univariate and multivariate Logistic Regression classification. The classification performance of the diagnostic model was evaluated by means of the Area Under Receiver Operating Characteristic curve (Az index). A combination of two features, one from 1st order statistics (25th Percentile) and one from 2nd order statistics, (texture Entropy), achieved high classification performance (Az = 0.965 ± 0.024), suggesting both the diagnostic significance of 1st order statistics and texture biomarkers of the ADC map representation.

Using mathematical models in a disequilibrium economy with offsetting demand

When modeling a nonequilibrium economy, the behavior of participants is described by the same optimization problems, including the criterion and internal technological and budgetary constraints, as in the theory of Walrasian equilibrium. They are only supplemented by external restrictions on the purchase (or sale) of scarce (slow-moving) products. Various principles are known for establishing these boundaries. They can be fixed (a rigid scheme of rationing) and not depend directly on the decisions of the participant, or be determined by the demand expressed by them (flexible scheme). The presented demand for rationable products, as a rule, does not coincide with the Walrasian one. We will call it an order. In well-known models, the order is considered equal to active demand. The concept of active demand has been successfully used in price control models. However, it is not the object of the choice of participants aimed at optimizing their criteria. Meanwhile, it seems natural that manufacturers and consumers, seeking to maximize utility, are free to choose order sizes at their own discretion. Modeling of the situation arising with this approach is the goal of the present work and is based on a modification of the rationing scheme proposed by J.P. Benassi The work also considers equilibrium models at fixed prices, in which participants, when forming demand, take into account the scarcity of products and the level of satisfaction of orders. Models are used to assess the impact of taxes, government spending, and other macro-regulators on employment and national income. The paper provides an overview of literary sources in the subject area, as well as an economic interpretation of the results.

Arithmetically rigid schemes via deformation theory of equivariant vector bundles

We analyze the deformation theory of equivariant vector bundles. In particular, we provide an effective criterion for verifying whether all infinitesimal deformations preserve the equivariant structure. As an application, using rigidity of the Frobenius homomorphism of general linear groups, we prove that projectivizations of Frobenius pullbacks of tautological vector bundles on Grassmanians are arithmetically rigid, that is, do not lift over rings where $$p \ne 0$$ . This gives the same conclusion for Totaro’s examples of Fano varieties violating Kodaira vanishing. We also provide an alternative purely geometric proof of non-liftability mod $$p^2$$ and to characteristic zero of the Frobenius homomorphism of a reductive group of non-exceptional type. In the appendix, written jointly with Piotr Achinger, we provide examples of non-liftable Calabi–Yau varieties in every characteristic $$p \geqslant 5$$ .

Постправда как риторический феномен в современном медиапространстве

The article considers the impact of CH. Perelman’s new rhetorical theory on post-truth phenomenon. Although the term “post-truth” appeared in the 1990s the peak of its popularity is the 2016–2020s. In 2016 the Oxford dictionary ranked it as the most used word in the media. The reason for this popularity according the most researchers is related to the spread and functioning of social networks where objective facts are less important in comparison with emotions and personal beliefs. The last five years are characterized by an increasing number of works in which the phenomenon of post-truth is investigated in the aspects of political science, social sociology, psychology, ethics. However, over the years not a single publication has appeared that treats post-truth as rhetorical phenomenon. The author of the article tries to fill this gap and highlight the main characteristic of post-truth rhetoric. Such features include a biased selection of facts and the way they are placed in media text, rigid scheme which includes four elements: a media person, criminal plot, step by step development of narrative and non-finished final. In the first of the scheme the media person can act as an organizer of an actual or imaginary event or as on object of extremal influence (a victim). The criminal nature of the plot is associated with a violation of the normal course of things. Moreover, such a violation should not be a one-time act but should assume development through the accumulation of new details. Also, to become a post-truth the event must contain the development potential associated with collision of opposite version explaining its meaning. In a situation of post-truth the role of the speaker in relation to audience changes. The speaker seeks not so much to join those who disagree with his point of view as to strengthen the split of the recipients who oppose each other. Thus, the post-truth as a method of information warfare and / or mastering the mass consciousness has become possible thanks to radical change in the media space excluding control over it. At the same time, its hidden premises appeal to the new rhetorical theory of Ch. Perelman.