GPU-accelerated ray-casting for 3D fiber orientation analysis

Orientation analysis of fibers is widely applied in the fields of medical, material and life sciences. The orientation information allows predicting properties and behavior of materials to validate and guide a fabrication process of materials with controlled fiber orientation. Meanwhile, development of detector systems for high-resolution non-invasive 3D imaging techniques led to a significant increase in the amount of generated data per a sample up to dozens of gigabytes. Though plenty of 3D orientation estimation algorithms were developed in recent years, neither of them can process large datasets in a reasonable amount of time. This fact complicates the further analysis and makes impossible fast feedback to adjust fabrication parameters. In this work, we present a new method for quantifying the 3D orientation of fibers. The GPU implementation of the proposed method surpasses another popular method for 3D orientation analysis regarding accuracy and speed. The validation of both methods was performed on a synthetic dataset with varying parameters of fibers. Moreover, the proposed method was applied to perform orientation analysis of scaffolds with different fibrous micro-architecture studied with the synchrotron μCT imaging setup. Each acquired dataset of size 600x600x450 voxels was analyzed in less 2 minutes using standard PC equipped with a single GPU

Rotated multifractal network generator

The recently introduced multifractal network generator (MFNG), has been shown to provide a simple and flexible tool for creating random graphs with very diverse features. The MFNG is based on multifractal measures embedded in 2d, leading also to isolated nodes, whose number is relatively low for realistic cases, but may become dominant in the limiting case of infinitely large network sizes. Here we discuss the relation between this effect and the information dimension for the 1d projection of the link probability measure (LPM), and argue that the node isolation can be avoided by a simple transformation of the LPM based on rotation.Comment: Accepted for publication in JSTA

ЭПИДЕМИОЛОГИЧЕСКИЕ И КЛИНИЧЕСКИЕ ОСОБЕННОСТИ СОЧЕТАННЫХ РЕСПИРАТОРНЫХ ИНФЕКЦИЙ У ДЕТЕЙ

Presents a review of publications on the problem of combined respiratory infections among children. Viral-bacterial associations are registered  in a group of often ill children in 51.7%. More than half of the patients have herpesvirus infection in various combinations. The presence of a combined acute respiratory viral infection among children in the group from 2 to 6 years was noted in 44.2% of cases, among which, in addition to influenza viruses, RS-, adeno-, etc., metapneumovirus and bocavirus plays an important role.The increase in severity of acute respiratory viral infection with combined  infection, with chlamydia  and mycoplasma infection is shown. A longer and more severe course of whooping cough was observed when combined with respiratory viruses.The revealed facts of frequency of distribution of combined  respiratory infections in children, the severity and duration of their course with the development of various complications and the formation of chronic pathology dictate the need to improve diagnosis and treatment tactics of these forms of infections.Представлен обзор публикаций по проблеме сочетанных респираторных инфекций среди детского населения. В группе  часто болеющих детей в 51,7% регистрируются вирусно-бактериальные ассоциации. Более, чем у половины больных выявляется герпесвирусная инфекция в различных сочетаниях. Наличие сочетанной ОРВИ среди детей в группе от 2 до 6 лет отмечено в 44,2% случаев, среди которой, помимо вирусов гриппа, РС-, аденои др., важную роль играют метапневмои бокавирусы.Показано  усиление тяжести  ОРВИ при сочетанном инфицировании, а  также на  фоне хламидийной и микоплазменной инфекции. Отмечено более длительное и тяжелое течение коклюша при сочетании с респираторными вирусами. Выявленные факты частоты распространения сочетанных респираторных инфекций у детей, тяжесть и длительность их течения с развитием различных  осложнений и формированием хронической патологии диктуют необходимость   совершенствования диагностики и тактики лечения данных форм инфекций.

Resonances of the cusp family

We study a family of chaotic maps with limit cases the tent map and the cusp map (the cusp family). We discuss the spectral properties of the corresponding Frobenius--Perron operator in different function spaces including spaces of analytic functions. A numerical study of the eigenvalues and eigenfunctions is performed.Comment: 14 pages, 3 figures. Submitted to J.Phys.

ПРОБЛЕМНЫЕ ВОПРОСЫ СОЧЕТАННОСТИ КИШЕЧНЫХ ИНФЕКЦИЙ

The  article  presents the  possible combinations of intestinal   infections of  various   etiologies, some   pathogenetic, clinical  and  epidemiological features and  problems of epidemiological surveillance and  control  of  associated infections.  Details  the  combination of typhoid fever,  shigelloses, salmonelloses, yersiniosis, pseudotuberculosis, rotavirus and norovirus infections between itself  and  other  infectious and parasitic diseases. Discusses the clinical  and  epidemiological features different combinations of intestinal infections. It is shown  that  the proportion of combined intestinal infections  can reach  to 48.9±3.3% in the structure of all associated  infections. The proportion of combination of two intestinal  infections pathogens was  29,2±6,5%, 3 agents and 10,3±4,3% and  4 pathogens and  5,9±11,6 percent. In the overall structure of the combination of intestinal anthroponoses with anthroponoses was 61,9±5,3%, anthroponoses with zoonoses was 31,1±5,0%, the other combinations (zoonoses and  zoonoses, zoonoses and  sapronoses, antroponoses with zoonoses and  sapronoses) of  7,0±9,3  percent. The  article raises  the  question of  the  need to  introduce into  existing regulatory framework the  new  scientific data  on the  whole range of features of the epidemiology of intestinal infections combined.В статье представлены возможные  сочетания кишечных инфекций различной этиологии, некоторые патогенетические, клинико-эпидемиологические особенности, а также проблемы эпидемиологического надзора  и контроля за сочетанным инфекциями. Подробно представлены сочетания брюшного тифа,   шигеллеза, сальмонеллеза, иерсиниоза,  псевдотуберкулеза,  ротавирусной и норовирусной инфекций между собой  и другими инфекционными и паразитарными заболеваниями. Рассматриваются клинико-эпидемиологические особенности различных сочетаний кишечных инфекций. Показано, что удельный вес сочетанных кишечных инфекций может  достигать 48,9±3,3%  в  структуре всех  сочетанных инфекций. Удельный вес  сочетания 2 возбудителей кишечных инфекций составил 29,2±6,5%,  3 возбудителей – 10,3±4,3%, 4 возбудителей – 5,9±11,6%. В общей  структуре сочетания кишечных антропонозов с  другими антропонозами составили 61,9±5,3%,  антропонозов с зоонозами – 31,1±5,0%, другие сочетания (зооноз и зооноз, зооноз и сапроноз, антропоноз с зоонозом  и сапронозом) – 7,0±9,3%. В статье поднимается вопрос о необходимости внедрять в существующую нормативно-правовую базу  новые научные данные по всему  спектру особенностей эпидемиологии сочетанных кишечных инфекций

Аспекты коморбидности у детей с COVID -19

Numerous literature data and our observations testify to the widespread permanent growth of combined infections, especially new ones, as well as combined infectious diseases with somatic ones. This is a new scientific direction in medicine, which we have designated as «complex comorbidity», and which can be considered as one of the main trends in the evolution of infectious pathology in general. The article presents an analysis of scientific articles on comorbidity with COVID-19 in children, taking into account clinical and epidemiological features in the pandemic (2020—2021) and pre-pandemic (2015—2019) periods. It has been estab- lished that the emergence of a new subtype of coronavirus at the end of 2019. An unfavorable epidemiological situation for seasonal coronavirus infection preceded by a pronounced trend towards an increase in the proportion of cases of diseases associated with coronavirus from 10.5% in the 2014—2015 epidemic season. up to 32.8% in the 2018—2019 season. The pandemic period was characterized by a lower susceptibility of children compared to adults, as well as a high proportion of «asymptomatic» and mild forms of infection. In turn, in the pre-pandemic period, «seasonal» coronaviruses preferred to infect, for the most part, precisely children's contingents with moderate onset of the disease.Многочисленные данные литературы и наши наблюдения свидетельствуют о повсеместном перманентном росте сочетанных инфекций, особенно новых, а также сочетании инфекционных болезней с соматическими. Это является новым научным направлением в медицине, которое нами обозначено как «комплексная коморбидность», и которое можно рассматривать как одну из основных тенденций эволюции инфекционной патологии в целом. В статье представлен анализ научных статей, касающихся сочетанной патологии с COVID-19 у детей с учетом клинико-эпидемиологических особенностей в пандемический (2020—2021 гг.) и в предпандемический (2015—2019 гг.) периоды. Установлено, что появлению нового подтипа коронавируса в конце 2019 г. предшествовала неблагоприятная эпидемиологическая ситуация по сезонной коронавирусной инфекции с выраженной тенденцией к увеличению удельного веса случаев заболеваний, связанных с коронавирусом с 10,5% в эпидсезон 2014—2015 гг. до 32,8% в сезон 2018—2019 гг. Пандемический период характеризовался более низкой восприимчивостью детей по сравнению со взрослыми, а также высокой долей «бессимптомных» и легких форм течения инфекции. В свою очередь в предпандемическом периоде «сезонные» коронавирусы предпочитали инфицировать в большинстве своем именно детские контингенты со средне-тяжелыми появлениями заболевания

Recurrence properties of hypercyclic operators

[EN] We generalize the notions of hypercyclic operators, U-frequently hypercyclic operators and frequently hypercyclic operators by introducing a new concept in linear dynamics, namely A-hypercyclicity. We then state an A-hypercyclicity criterion, inspired by the hypercyclicity criterion and the frequent hypercyclicity criterion, and we show that this criterion characterizes the A-hypercyclicity for weighted shifts. We also investigate which density properties can the sets N(x, U) = {n is an element of N; T-n x is an element of U} have for a given hypercyclic operator, and we study the new notion of reiteratively hypercyclic operators.This work is supported in part by MEC and FEDER, Project MTM2013-47093-P, and by GVA, Projects PROMETEOII/2013/013 and ACOMP/2015/005. The second author was a postdoctoral researcher of the Belgian FNRS.Bès, JP.; Menet, Q.; Peris Manguillot, A.; Puig-De Dios, Y. (2016). Recurrence properties of hypercyclic operators. Mathematische Annalen. 366(1):545-572. https://doi.org/10.1007/s00208-015-1336-3S5455723661Badea, C., Grivaux, S.: Unimodular eigenvalues, uniformly distributed sequences and linear dynamics. Adv. Math. 211, 766–793 (2007)Bayart, F., Grivaux, S.: Frequently hypercyclic operators. Trans. Amer. Math. Soc. 358, 5083–5117 (2006)Bayart, F., Grivaux, S.: Invariant Gaussian measures for operators on Banach spaces and linear dynamics. Proc. Lond. Math. Soc. 94, 181–210 (2007)Bayart, F., Matheron, É.: Dynamics of linear operators, Cambridge Tracts in Mathematics, 179. Cambridge University Press, Cambridge (2009)Bayart, F., Matheron, É.: (Non-)weakly mixing operators and hypercyclicity sets. Ann. Inst. Fourier 59, 1–35 (2009)Bayart, F., Ruzsa, I.: Difference sets and frequently hypercyclic weighted shifts. Ergodic Theory Dynam. Syst. 35, 691–709 (2015)Bergelson, V.: Ergodic Ramsey Theory- an update, Ergodic Theory of $$\mathbb{Z}^d$$ Z d -actions. Lond. Math. Soc. Lecture Note Ser. 28, 1–61 (1996)Bernal-González, L., Grosse-Erdmann, K.-G.: The Hypercyclicity Criterion for sequences of operators. Studia Math. 157, 17–32 (2003)Bès, J., Peris, A.: Hereditarily hypercyclic operators. J. Funct. Anal. 167, 94–112 (1999)Bonilla, A., Grosse-Erdmann, K.-G.: Frequently hypercyclic operators and vectors. Ergodic Theory Dynam. Syst. 27, 383–404 (2007)Bonilla, A., Grosse-Erdmann, K.-G.: Erratum: Ergodic Theory Dynam. Systems 29, 1993–1994 (2009)Chan, K., Seceleanu, I.: Hypercyclicity of shifts as a zero-one law of orbital limit points. J. Oper. Theory 67, 257–277 (2012)Costakis, G., Sambarino, M.: Topologically mixing hypercyclic operators. Proc. Amer. Math. Soc. 132, 385–389 (2004)Furstenberg, H.: Recurrence in ergodic theory and combinatorial number theory. Princeton University Press, Princeton (1981)Giuliano, R., Grekos, G., Mišík, L.: Open problems on densities II, Diophantine Analysis and Related Fields 2010. AIP Conf. Proc. 1264, 114–128 (2010)Grosse-Erdmann, K.-G.: Hypercyclic and chaotic weighted shifts. Studia Math. 139, 47–68 (2000)Grosse-Erdmann, K.-G., Peris, A.: Frequently dense orbits. C. R. Math. Acad. Sci. Paris 341, 123–128 (2005)Grosse-Erdmann, K.G., Peris, A.: Weakly mixing operators on topological vector spaces, Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Math. RACSAM, 104, 413–426 (2010)Grosse-Erdmann, K.G., Peris Manguillot, A.: Linear chaos, Universitext. Springer, London (2011)Menet, Q.: Linear chaos and frequent hypercyclicity. Trans. Amer. Math. Soc. arXiv:1410.7173Puig, Y.: Linear dynamics and recurrence properties defined via essential idempotents of $$\beta {\mathbb{N}}$$ β N (2014) arXiv:1411.7729 (preprint)Salas, H.N.: Hypercyclic weighted shifts. Trans. Amer. Math. Soc. 347, 993–1004 (1995)Salat, T., Toma, V.: A classical Olivier’s theorem and statistical convergence. Ann. Math. Blaise Pascal 10, 305–313 (2003)Shkarin, S.: On the spectrum of frequently hypercyclic operators. Proc. Am. Math. Soc. 137, 123–134 (2009

Moment Semantics for Reversible Rule-Based Systems

International audienceWe develop a notion of stochastic rewriting over marked graphs – i.e. directed multigraphs with degree constraints. The approach is based on double-pushout (DPO) graph rewriting. Marked graphs are expressive enough to internalize the 'no-dangling-edge' condition inherent in DPO rewriting. Our main result is that the linear span of marked graph occurrence-counting functions – or motif functions – form an algebra which is closed under the infinitesimal generator of (the Markov chain associated with) any such rewriting system. This gives a general procedure to derive the moment semantics of any such rewriting system, as a countable (and recursively enumerable) system of differential equations indexed by motif functions. The differential system describes the time evolution of moments (of any order) of these motif functions under the rewriting system. We illustrate the semantics using the example of preferential attachment networks; a well-studied complex system, which meshes well with our notion of marked graph rewriting. We show how in this case our procedure obtains a finite description of all moments of degree counts for a fixed degree