О подобии задач комбинаторной оптимизации и универсальности алгоритмов

Розглянуто властивість подібності, яка має місце в комбінаториці та комбінаторній оптимізації. Виявлено різноманітні ознаки, за якими вона визначається для задач, що відносяться до різних класів. Описано задачі комбінаторної оптимізації, які подібні за аргументом цільової функції, а в комбінаториці — за способом утворення та упорядкування комбінаторних конфігурацій. Завдяки цій властивості їхні множини генеруються одним і тим же алгоритмом або його модифікацією. Показано, що деякі задачі комбінаторної оптимізації, що відносяться до різних класів, розділяються на подібні підзадачі, які розв’язуються за однією обчислювальною схемою. Властивість подібності, яка характерна для задач цього класу, визначає їхню універсальність, завдяки якій вони розв’язуються за одним і тим же методом. Вивчення та використання цієї властивості в комбінаторній оптимізації в подальшому дозволить зводити нерозв’язні задачі до розв’язних.A property of similarity which takes place in combinatorics and combinatorial optimization is examined. The various signs, after which it is determined for problems, which belong to the different classes, are defined. The problems of combinatorial optimization, which are similar by the argument of objective function, and in combinatorics – by the method of formation and ordering of combinatorial configurations, are described. Due to this property their sets are generated by the same algorithm or its modification. It is shown that some combinatorial optimization problems, which belong to different classes are divided into similar subproblems that are solved by the same calculable scheme. The property of similarity, which is typical for this class of problems, determines their universality by which they are solved by the same method. A study and use of this property in the combinatorial optimization in the future will reduce the insoluble problems to the solvables.Рассмотрено свойство подобия, которое имеет место в комбинаторике и комбинаторной оптимизации. Выявлены различные признаки, по которым оно определяется для задач, относящихся к разным классам. Описаны задачи комбинаторной оптимизации, которые подобны по аргументу целевой функции, а в комбинаторике — по способу образования и упорядочения комбинаторных конфигураций. Благодаря этому свойству их множества генерируются одним и тем же алгоритмом или его модификацией. Показано, что некоторые задачи комбинаторной оптимизации, относящиеся к разным классам, разделяются на подобные подзадачи, решаемые по одной вычислительной схеме. Свойство подобия, которое характерно для задач этого класса, определяет их универсальность, благодаря которой они решаются одним и тем же методом. Изучение и использование этого свойства в комбинаторной оптимизации в дальнейшем позволит сводить неразрешимые задачи к разрешимым

Democratization in a passive dendritic tree : an analytical investigation

One way to achieve amplification of distal synaptic inputs on a dendritic tree is to scale the amplitude and/or duration of the synaptic conductance with its distance from the soma. This is an example of what is often referred to as “dendritic democracy”. Although well studied experimentally, to date this phenomenon has not been thoroughly explored from a mathematical perspective. In this paper we adopt a passive model of a dendritic tree with distributed excitatory synaptic conductances and analyze a number of key measures of democracy. In particular, via moment methods we derive laws for the transport, from synapse to soma, of strength, characteristic time, and dispersion. These laws lead immediately to synaptic scalings that overcome attenuation with distance. We follow this with a Neumann approximation of Green’s representation that readily produces the synaptic scaling that democratizes the peak somatic voltage response. Results are obtained for both idealized geometries and for the more realistic geometry of a rat CA1 pyramidal cell. For each measure of democratization we produce and contrast the synaptic scaling associated with treating the synapse as either a conductance change or a current injection. We find that our respective scalings agree up to a critical distance from the soma and we reveal how this critical distance decreases with decreasing branch radius

Integrated approach to radiodiagnosis of follicular thyroid neoplasia: a retrospective cohort trial

Background. An evidence-based diagnostic tactics for follicular thyroid gland neoplasia is lacking to date. First-line priority are radiography diagnostic techniques, which vary in capacities and therefore must be regulated in use.Objectives. An efficacy evaluation of multiparametric ultrasound (US), sonoelastography (SEG) and radionuclide scintigraphy (RS) in diagnosis of follicular thyroid neoplasms (FTN).Methods. Preoperative examination was interpreted in 222 FTN patients (86 with follicular thyroid adenoma, FTA, and 136 with follicular thyroid cancer, FTC) with subsequent surgery. A retrospective statistical data analysis was performed for B-mode US, colour Doppler imaging (CDI), power Doppler imaging (PDI), sonoelastography and Tc-99m pertechnetate scintigraphy.Results. Novel FTN descriptive evidence has been obtained. Particularly, an FTA vs. FTC trait comparison showed no reliable US marker of a node assignment to FTA or FTC. Trials of the national-manufactured TI-RADS system showed its good diagnostic potential: FTN sensitivity 89.55, specificity 77.58 and accuracy 83.52%. A SEG picture of FTN was typically motley-colour and mosaic. Young’s modulus in FTA was 27.5 ± 7.1 kPa, a higher stiffness (62.1 ± 12.1 kPa) in FTC indicated a higher likelihood of malignancy. Scintigraphy exhibited a modest capacity for FTN diagnosis (sensitivity 86.67, specificity 48.08 and accuracy 56.72%). AUC values (0.617) indicate its limited use for differential FTN diagnosis, mainly in hyperfunctioning nodules. Our experience elaborated an original algorithm for radiographic techniques application in FTN diagnosis.Conclusion. Several radiographic methods are warranted in suspected FTN. First-line is multiparametric US B-mode imaging to detect FTN priority markers and US symptom complexes. Sonoelastography is second-line in ambiguous cases to further clarify structure (stiffness) of the thyroid nodule examined. Unlike SEG, scintigraphy assesses the functional traits of thyroid nodule and so has limited indications, an important factor to consider in FTN

Zymography: developing of the enzyme soil activity visualization method

The enzymes produced by the soil biota are a key link in the regulation of biochemical processes. The soil enzyme activity can be visualized with zymography, a method based on using fluorescent substrates and obtaining two-dimensional images (zymograms). A variant of a zymographic measuring system has been proposed. Characteristics of lighting, photographic equipment and shooting modes, reagents preparation and calibration are presented. Preparing and analyzing soil samples of different texture (sand and clay loam) and processing the study results have been described. The ways of introducing the substrate are considered in this study, namely pipetting, short-time dipping, and saturation. An analysis of the kinetics of incubation of samples was carried out. The possibilities and disadvantages of the method were also considered and options for solving possible methodological problems during the analysis were proposed. The zymography is a promising method that allows comparing data with the results of other methods. The use of neural network technologies makes it possible to obtain the volumetric distribution of soil enzymes with high reliability. The soil zymography requires qualitative preparatory work and extreme accuracy during the analysis. It is necessary to ensure maximum contact between the substrate and the soil, as this is one of the key factors determining the quality of the results. The most optimal way to introduce the substrate is to saturate the membranes with substrate solution for 60 minutes. At this stage of the development of the method, it is not possible to establish a universal sample incubation time, since this depends on characteristics of both the studied soils and the experiment conditions. Also, it is necessary to document the conditions in detail for discussion the study results

Phase 3 study of recombinant von Willebrand factor in patients with severe von Willebrand disease who are undergoing elective surgery

Essentials Recombinant von Willebrand factor (rVWF) is effective in von Willebrand disease (VWD). A phase 3 study of rVWF, with/without recombinant factor VIII (rFVIII) before surgery in VWD. Overall rVWF's efficacy was rated excellent/good; rVWF was administered alone in most patients. rVWF was well-tolerated and hemostasis was achieved in patients with severe VWD undergoing surgery. Summary: Background Recombinant von Willebrand factor (rVWF) has demonstrated efficacy for on-demand treatment of bleeding in severe von Willebrand disease (VWD), warranting evaluation in the surgical setting. Objectives This study (NCT02283268) evaluated the hemostatic efficacy/safety profile of rVWF, with/without recombinant factor VIII (rFVIII), in patients with severe VWD undergoing surgery. Patients/Methods Patients received rVWF 40\u201360\ua0IU\ua0kg 121, VWF ristocetin cofactor activity was measured 12\u201324\ua0h before surgery. If endogenous FVIII activity (FVIII:C) target levels were achieved 3\ua0h before surgery, rVWF was administered alone 1\ua0h before surgery; rVWF was co-administered with rFVIII if target endogenous FVIII levels were not achieved. rVWF was infused postoperatively to maintain target trough levels. Overall and intraoperative hemostatic efficacy, the pharmacodynamics of rVWF administration and the incidence of adverse events (AEs) were assessed. Results All patients treated with rVWF for major (n\ua0=\ua010), minor (n\ua0=\ua04) and oral (n\ua0=\ua01) surgery had overall and intraoperative hemostatic efficacy ratings of excellent (73.3% and 86.7%) or good (26.7% and 13.3%). Most rVWF infusions (89.4%) were administered alone, resulting in hemostatically effective levels of endogenous FVIII within 6\ua0h, which were sustained for 72\u201396\ua0h; 70% (n\ua0=\ua07/10) of major surgeries\ua0were performed without rFVIII co-administration. Six patients reported 12 treatment-emergent AEs. Two\ua0patients each had one serious AE: diverticulitis (not treatment related) and deep vein thrombosis (sponsor-assessed as possibly treatment related). No severe allergic reactions or inhibitory antibodies were reported. Conclusions These data support the efficacy and safety profile of rVWF in patients with severe VWD undergoing elective surgery

Growth of Transition-Metal Dichalcogenides by Solvent Evaporation Technique

Due to their physical properties and potential applications in energy conversion and storage, transition-metal dichalcogenides (TMDs) have garnered substantial interest in recent years. Among this class of materials, TMDs based on molybdenum, tungsten, sulfur, and selenium are particularly attractive due to their semiconducting properties and the availability of bottom-up synthesis techniques. Here we report a method which yields high-quality crystals of transition-metal diselenide and ditelluride compounds (PtTe2, PdTe2, NiTe2, TaTe2, TiTe2, RuTe2, PtSe2, PdSe2, NbSe2, TiSe2, VSe2, ReSe2) from their solid solutions, via vapor deposition from a metal-saturated chalcogen melt. Additionally, we show the synthesis of rare-earth-metal polychalcogenides and NbS2 crystals using the aforementioned process. Most of the crystals obtained have a layered CdI2 structure. We have investigated the physical properties of selected crystals and compared them to state of the art findings reported in the literature. Remarkably, the charge density wave transition in 1T-TiSe2 and 2H-NbSe2 crystals is well-defined at TCDW ≈ 200 and 33 K, respectively. Angle-resolved photoelectron spectroscopy and electron diffraction are used to directly access the electronic and crystal structures of PtTe2 single crystals and yield state of the art measurements. © 2020 American Chemical Society.M.A.-H. acknowledges support from the VR starting grant 2018-05339 and KL1824/6. The crystal growth experiments were supported by the Russian Science Foundation, Project 19-12-00414. The work has been supported by the program 211 of the Russian Federation Government agreements 02.A03.21.0006 and 02.A03.21.0011, by the Russian Government Program of Competitive Growth of Kazan Federal University. We acknowledge MAX IV Laboratory for time on Beamline Bloch under Proposal 20190335. Research conducted at MAX IV, a Swedish national user facility, is supported by the Swedish Research council under contract 2018-07152 the Swedish Governmental Agency for Innovation Systems under contract 2018-04969, and Formas under contract 2019-02496. We acknowledge ARPES experiment support from Craig Polley (MAX IV), Maciej Dendzik (KTH) Antonija Grubisic-Cabo (KTH) and Oscar Tjernberg (KTH). H.R., D.P. and G.J.M. acknowledge the Swedish Research Council (2018-06465, 2018-04330) and the Swedish Energy Agency (P43549-1) for financial support

Greener Method to Obtain a Key Intermediate of Vitamin E over Cu-ZSM-5

The catalytic oxidation of 2,3,5-trimethylphenol was performed over transition metals modified ZSM-5 zeolites employing hydrogen peroxide as oxidant under mild reaction conditions. Catalysts samples were characterized by several techniques (XRD, FTIR, BET, AA) and cristallinity and orthorhombic symmetry were confirmed for all of them. Best catalytic results were obtained for Cu-ZSM-5 sample, so further activity studies were done over this material. 2,3,5-trimethyl-1,4-benzoquinone was obtained as the main product of the selective oxidation. Reaction parameters (nature of the solvent, hydrogen peroxide concentration, reaction time, catalyst mass, substrate initial concentration and reaction temperature) were evaluated to reach the optimum reaction conditions. According to the obtained results, an apparent activation energy of 52.33 kJ/mol was calculated.Fil: Saux, Clara. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; ArgentinaFil: Renzini, Maria Soledad. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; ArgentinaFil: Gómez, Silvina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; ArgentinaFil: Pierella, Liliana Beatriz. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; Argentin

The adaptive potential of North American subtype H7N2 avian influenza viruses to mammals

Introduction. H7 subtype avian influenza viruses causing severe epizootics among birds are phylogenetically different in the Eastern and Western hemispheres. Numerous human infections caused by these viruses in the Eastern hemisphere indicate that H7 viruses can overcome the interspecies barrier and pose a potential threat of a new pandemic.The H7N2 viruses with deletion of amino acids 221–228 (H3 numbering) in hemagglutinin (HA) had been circulating among poultry in the Western Hemisphere during 1996–2006, and had once again been detected in 2016 in an animal shelter, where they caused cat diseases. The objective of this study is to elucidate the mechanism of adaptation to mammals of North American H7N2 influenza viruses with deletion in HA. Materials and methods. The A/chicken/New Jersey/294598-12/2004 (H7N2) virus was adapted to mice by the lung passages. Complete genomes of original and mouse-adapted viruses were analyzed. The receptor specificity and thermostability of viruses, HA activation pH and virulence for mice were determined. Results. The non-pathogenic H7N2 avian influenza virus became pathogenic after 10 passages in mice. Amino acid substitutions occurred in five viral proteins: one in PB2 (E627K), NA (K127N), NEP (E14Q), four in HA and six in NS1. Mutations in HA slightly changed receptor specificity but increased the pH of HA activation by 0.4 units. The NS1 protein undergone the greatest changes in the positions (N73T, S114G, K118R, G171A, F214L and G224R), where amino acid polymorphisms were observed in the original virus, but only minor amino acid variants have been preserved in the mouse adapted variant. Conclusion. The results show that H7N2 viruses have the potential to adapt to mammals. The increase in virulence is most likely due to the adaptive E627K mutation in PB2 and possibly in HA

The FIELDS Instrument Suite for Solar Probe Plus: Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients.

NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products

The current state of the legal regulation of psychological assistance

uniformed terminology across the country and separating governmental and non-governmental psychological counselling rendered. Such gap also does not correspond with the interests of the clients that counselling is focused on since the experts who are allowed to extend those services are undetermined and undefined. Objective. The paper is directed at analyzing the status quo of legal regulation of the psychological counselling, finding gaps in such regulation and proving the need in a special federal law. Research Progress. The paper takes an account of the current state of regulation of psychological counselling in the Russian Federation and foreign countries using the comparative legal analysis approach.The research resulted in a finding that there is the need in a special federal law on psychological counselling. Conclusion. Special federal law on psychological counselling of the population is necessary to elaborate and eventually to implement for uniformity in counselling and in social work services, and also to protect the rights and interests of those who seek councelling, as well as determining the qualifications of those to render such services. Practical Application. The research results can be used while drafting and passing a special federal law on psychological counselling and executive regulatory acts