scholarly journals Nonstoichiometric balanced complexes: Implications on the effective deficiency of the underlying metabolic network

2021 ◽  
Author(s):  
Damoun Langary ◽  
Anika Kueken ◽  
Zoran Nikoloski
Keyword(s):  
Steady State ◽  
Complex Formation ◽  
Real World ◽  
Formation Rate ◽  
Dynamical Behavior ◽  
Reaction Network ◽  
Biochemical Networks ◽  
Classical Definition ◽  
Rate Vector ◽  
Definition Of

The deficiency of a (bio)chemical reaction network can be conceptually interpreted as a measure of its ability to support exotic dynamical behavior and/or multistationarity. The classical definition of deficiency relates to the capacity of a network to permit variations of the complex formation rate vector at steady state, irrespective of the network kinetics. However, the deficiency is by definition completely insensitive to the fine details of the directionality of reactions as well as bounds on reaction fluxes. While the classical definition of deficiency can be readily applied in the analysis of unconstrained, weakly reversible networks, it only provides an upper bound in the cases where relevant constraints on reaction fluxes are imposed. Here we propose the concept of effective deficiency, which provides a more accurate assessment of the networks capacity to permit steady state variations at the complex level for constrained networks of any reversibility patterns. The effective deficiency relies on the concept of nonstoichiometric balanced complexes, which we have already shown to be present in real-world biochemical networks operating under flux constraints. Our results demonstrate that the effective deficiency of real-world biochemical networks is smaller than the classical deficiency, indicating the effects of reaction directionality and flux bounds on the variation of the complex formation rate vector at steady state.

scholarly journals Bringing Multi-agent Path Finding Closer to Reality

2018 ◽  
Author(s):  
Jiří Švancara
Keyword(s):  
Real World ◽  
Path Finding ◽  
Multiple Agents ◽  
New Agents ◽  
The Real ◽  
Classical Definition ◽  
Multi Agent ◽  
Definition Of

Multi-agent path finding is the problem of navigating multiple agents from their current locations to their goal locations in such a way that there are no collisions between the agents. The classical definition of the problem assumes that the set of agents is unchangeable, and that the distances in the graph are homogeneous. We propose to add to the problem specification a set of new attributes to bring it closer to the real world. These attributes include varying distances, number of agents that can occupy an edge or node, and dynamic appearance of new agents.

scholarly journals AB0677 REVISING THE DEFINITION OF REACTIVE ARTHRITIS AND DIFFERENTIATION FROM UNDIFFERENTIATED SPONDYLOARTHRITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1633.2-1634
Author(s):  
F. Cosan ◽  
O. M. Gedar
Keyword(s):  
Causative Agent ◽  
Reactive Arthritis ◽  
Case Reports ◽  
Experimental Studies ◽  
Classification Criteria ◽  
General Definition ◽  
Parasitic Infections ◽  
Undifferentiated Spondyloarthritis ◽  
Classical Definition ◽  
Definition Of

Background:Reactive arthritis (ReA) is defined by 1999 ACR criteria as arthritis preceding a bacterial genitourinary (GUS) or gastrointestinal (GIS) infection in 3 days-6 weeks and evidence of triggering infection. Recently, ReA is classified as SpA and patients who do not fulfill SpA criteria are classified as undifferentiated spondyloarthritis (USpA) according to ASAS/EULAR SpA classification criteria.Objectives:In several case reports which are associated with other infective agents are reported and the definition is extended for some clinicians so that SpA which is occurred after any infection is called as ReA. On the other hand, some researchers still accept the classical definition of ReA. The problem with the heterogeneity of opinions and unstandardized definition of ReA hinders studies about pathogenesis and standardization of treatments. In this study, we aimed to determine the spectrum of the use of the definition of reactive arthritis in publications in PubMed between 2009-2019.Methods:The ReA keyword is searched in PubMed for the years between 2009-2019. 248 different publications have been identified and included in this research. 89 articles, 47 reviews, 108 case reports, 2 guidelines, and 2 editorials reviewed for the definition of ReA.Results:Only 42.7% (106 patients) of these publications meet the classical definition which suggests ReA after only GIS and GUS infections. In 4 (1.6%) of the publications ReA was defined after GIS, GUS and oropharyngeal infections; in 3 (1,2%) of the publications after any bacterial infection; in 9 (3.6%) of the publications after any infection. In 8 (3.2%) of the publications, ReA and USPA was used correspondingly. In 39 (15,7%) of the publications the term agent related, ReA was used without making a general definition for ReA. 79 publications (31,9%) have not defined ReA.According to causative agent and ReA relationship, in 64 (24,6%) general infective agents, in 75 (30,2%) classical agents, in 22 (8,9%) other bacterial agents, in 23 (9,3%) streptococcus, in 10(4%) intravesical BCG, in 6 (2.4%) HIV, in 6 (2.4%) tuberculosis, in 12 (4,8%) clostrudium difficle, in 2 (0.8%) parasites were reported. In 31 (12,5%) of the publications the causative agent for the ReA was unknown, the diagnosis was made clinically.Conclusion:In this study, it is aimed to draw attention terminology intricacy and the need for the standardization of the definition of ReA and USpA. It is clear that to standardize the definition of Rea and USpA is necessary. Between 2009-2019 there are reported cases diagnosed as ReA associated with bacterial infections (especially with Clostridium difficile, streptococcus and tuberculosis infections), and viral infections (by a majority with HIV), and parasitic infections. It is not clear if we need to define them classically or define them as USPA. Another important consideration is the necessity of extended laboratory investigations to find out the real causative agent even if the patient is clinically diagnosed with ReA. The requirement of the differentiation between ReA and USpA must be revealed for therapeutic researches.References:[1]A proposal for the classification of patients for clinical and experimental studies on reactive arthritis. Pacheco-Tena C, Burgos-Vargas R, Vázquez-Mellado J, Cazarín J, Pérez-Díaz JA. J Rheumatol. 1999 Jun;26(6):1338-46.[2]The Assessment of SpondyloArthritis International Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in general. Rudwaleit M, van der Heijde D, Landewé R, Akkoc N, Brandt J, Chou CT, Dougados M, Huang F, Gu J, Kirazli Y, et al. Ann Rheum Dis. 2011;70:25–31.Disclosure of Interests:None declared

Personalised attraction recommendation for enhancing topic diversity and accuracy

2021 ◽  
pp. 016555152199980
Author(s):  
Yuanyuan Lin ◽  
Chao Huang ◽  
Wei Yao ◽  
Yifei Shao
Keyword(s):  
Real World ◽  
Information Overload ◽  
Two Stage ◽  
Misclassification Cost ◽  
Second Stage ◽  
Low Visibility ◽  
Recommendation Diversity ◽  
Optimisation Model ◽  
Definition Of ◽  
Improved Methods

Attraction recommendation plays an important role in tourism, such as solving information overload problems and recommending proper attractions to users. Currently, most recommendation methods are dedicated to improving the accuracy of recommendations. However, recommendation methods only focusing on accuracy tend to recommend popular items that are often purchased by users, which results in a lack of diversity and low visibility of non-popular items. Hence, many studies have suggested the importance of recommendation diversity and proposed improved methods, but there is room for improvement. First, the definition of diversity for different items requires consideration for domain characteristics. Second, the existing algorithms for improving diversity sacrifice the accuracy of recommendations. Therefore, the article utilises the topic ‘features of attractions’ to define the calculation method of recommendation diversity. We developed a two-stage optimisation model to enhance recommendation diversity while maintaining the accuracy of recommendations. In the first stage, an optimisation model considering topic diversity is proposed to increase recommendation diversity and generate candidate attractions. In the second stage, we propose a minimisation misclassification cost optimisation model to balance recommendation diversity and accuracy. To assess the performance of the proposed method, experiments are conducted with real-world travel data. The results indicate that the proposed two-stage optimisation model can significantly improve the diversity and accuracy of recommendations.

Decreased Gamma Auditory Steady-State Response Is Associated With Impaired Real-World Functioning in Unmedicated Patients at Clinical High Risk for Psychosis

2020 ◽  
pp. 155005942098270
Author(s):  
Sarah Ahmed ◽  
Jennifer R. Lepock ◽  
Romina Mizrahi ◽  
R. Michael Bagby ◽  
Cory J. Gerritsen ◽  
...  
Keyword(s):  
Steady State ◽  
High Risk ◽  
Functional Impairment ◽  
Real World ◽  
Steady State Response ◽  
Clinical High Risk ◽  
State Response ◽  
Auditory Steady State Response ◽  
Gamma Synchrony ◽  
40 Hz

Aim Deficits in synchronous, gamma-frequency neural oscillations may contribute to schizophrenia patients’ real-world functional impairment and can be measured electroencephalographically using the auditory steady-state response (ASSR). Gamma ASSR deficits have been reported in schizophrenia patients and individuals at clinical high risk (CHR) for developing psychosis. We hypothesized that, in CHR patients, gamma ASSR would correlate with real-world functioning, consistent with a role for gamma synchrony deficits in functional impairment. Methods A total of 35 CHR patients rated on Global Functioning: Social and Role scales had EEG recorded while listening to 1-ms, 93-dB clicks presented at 40 Hz in 500-ms trains, in response to which 40-Hz evoked power and intertrial phase-locking factor (PLF) were measured. Results In CHR patients, lower 40-Hz PLF correlated with lower social functioning. Conclusions Gamma synchrony deficits may be a biomarker of real-world impairment at early stages of the schizophrenia disease trajectory.

scholarly journals Betweenness centrality for temporal multiplexes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Silvia Zaoli ◽  
Piero Mazzarisi ◽  
Fabrizio Lillo
Keyword(s):  
Information Flow ◽  
Real World ◽  
Betweenness Centrality ◽  
Temporal Structure ◽  
Shortest Paths ◽  
Single Layer ◽  
Distance Metric ◽  
Definition Of

AbstractBetweenness centrality quantifies the importance of a vertex for the information flow in a network. The standard betweenness centrality applies to static single-layer networks, but many real world networks are both dynamic and made of several layers. We propose a definition of betweenness centrality for temporal multiplexes. This definition accounts for the topological and temporal structure and for the duration of paths in the determination of the shortest paths. We propose an algorithm to compute the new metric using a mapping to a static graph. We apply the metric to a dataset of $$\sim 20$$ ∼ 20 k European flights and compare the results with those obtained with static or single-layer metrics. The differences in the airports rankings highlight the importance of considering the temporal multiplex structure and an appropriate distance metric.

scholarly journals Nonlinear Dynamics and Stability Analysis of a Three-Cell Flying Capacitor DC-DC Converter

2021 ◽  
Vol 11 (4) ◽  
pp. 1395
Author(s):  
Abdelali El Aroudi ◽  
Natalia Cañas-Estrada ◽  
Mohamed Debbat ◽  
Mohamed Al-Numay
Keyword(s):  
Steady State ◽  
Stability Analysis ◽  
Monodromy Matrix ◽  
Dynamical Behavior ◽  
Period Doubling ◽  
Simple Expression ◽  
Buck Converter ◽  
State Variables ◽  
Bifurcation Phenomena ◽  
The Stability

This paper presents a study of the nonlinear dynamic behavior a flying capacitor four-level three-cell DC-DC buck converter. Its stability analysis is performed and its stability boundaries is determined in the multi-dimensional paramertic space. First, the switched model of the converter is presented. Then, a discrete-time controller for the converter is proposed. The controller is is responsible for both balancing the flying capacitor voltages from one hand and for output current regulation. Simulation results from the switched model of the converter under the proposed controller are presented. The results show that the system may undergo bifurcation phenomena and period doubling route to chaos when some system parameters are varied. One-dimensional bifurcation diagrams are computed and used to explore the possible dynamical behavior of the system. By using Floquet theory and Filippov method to derive the monodromy matrix, the bifurcation behavior observed in the converter is accurately predicted. Based on justified and realistic approximations of the system state variables waveforms, simple and accurate expressions for these steady-state values and the monodromy matrix are derived and validated. The simple expression of the steady-state operation and the monodromy matrix allow to analytically predict the onset of instability in the system and the stability region in the parametric space is determined. Numerical simulations from the exact switched model validate the theoretical predictions.

Formation-Rate-Analysis Technique: Combined Drawdown and Buildup Analysis for Wireline Formation Test Data

1999 ◽  
Vol 2 (03) ◽  
pp. 271-280 ◽  
Author(s):  
Ekrem Kasap ◽  
Kun Huang ◽  
Than Shwe ◽  
Dan Georgi
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Field Data ◽  
Formation Rate ◽  
Flow Analysis ◽  
Early Time ◽  
Late Time ◽  
Time Data ◽  
Analysis Techniques ◽  
Conventional Analysis

Summary The formation-rate-analysis (FRASM) technique is introduced. The technique is based on the calculated formation rate by correcting the piston rate with fluid compressibility. A geometric factor is used to account for irregular flow geometry caused by probe drawdown. The technique focuses on the flow from formation, is applicable to both drawdown and buildup data simultaneously, does not require long buildup periods, and can be implemented with a multilinear regression, from which near-wellbore permeability, p * and formation fluid compressibility are readily determined. The field data applications indicate that FRA is much less amenable to data quality because it utilizes the entire data set. Introduction A wireline formation test (WFT) is initiated when a probe from the tool is set against the formation. A measured volume of fluid is then withdrawn from the formation through the probe. The test continues with a buildup period until pressure in the tool reaches formation pressure. WFTs provide formation fluid samples and produce high-precision vertical pressure profiles, which, in turn, can be used to identify formation fluid types and locate fluid contacts. Wireline formation testing is much faster compared with the regular pressure transient testing. Total drawdown time for a formation test is just a few seconds and buildup times vary from less than a second (for permeability of hundreds of millidarcy) to half a minute (for permeability of less than 0.1 md), depending on system volume, drawdown rate, and formation permeability. Because WFT tested volume can be small (a few cubic centimeters), the details of reservoir heterogeneity on a fine scale are given with better spatial resolution than is possible with conventional pressure transient tests. Furthermore, WFTs may be preferable to laboratory core permeability measurements since WFTs are conducted at in-situ reservoir stress and temperature. Various conventional analysis techniques are used in the industry. Spherical-flow analysis utilizes early-time buildup data and usually gives permeability that is within an order of magnitude of the true permeability. For p* determination, cylindrical-flow analysis is preferred because it focuses on late-time buildup data. However, both the cylindrical- and spherical-flow analyses have their drawbacks. Early-time data in spherical-flow analysis results in erroneous p* estimation. Late-time data are obtained after long testing times, especially in low-permeability formations; however, long testing periods are not desirable because of potential tool "sticking" problems. Even after extended testing times, the cylindrical-flow period may not occur or may not be detectable on WFTs. When it does occur, permeability estimates derived from the cylindrical-flow period may be incorrect and their validity is difficult to judge. New concepts and analysis techniques, combined with 3-D numerical studies, have recently been reported in the literature.1–7 Three-dimensional numerical simulation studies1–6 have contributed to the diagnosis of WFT-related problems and the improved analysis of WFT data. The experimental studies7 showed that the geometric factor concept is valid for unsteady state probe pressure tests. This study presents the FRA technique8 that can be applied to the entire WFT where a plot for both drawdown and buildup periods renders straight lines with identical slopes. Numerical simulation studies were used to generate data to test both the conventional and the FRA techniques. The numerical simulation data are ideally suited for such studies because the correct answer is known (e.g., the input data). The new technique and the conventional analysis techniques are also applied to the field data and the results are compared. We first review the theory of conventional analysis techniques, then present the FRA technique for combined drawdown and buildup data. A discussion of the numerical results and the field data applications are followed by the conclusions. Analysis Techniques It has been industry practice to use three conventional techniques, i.e., pseudo-steady-state drawdown (PSSDD), spherical and cylindrical-flow analyses, to calculate permeability and p* Conventional Techniques Pseudo-Steady-State Drawdown (PSSDD). When drawdown data are analyzed, it is assumed that late in the drawdown period the pressure drop stabilizes and the system approaches to a pseudo-steady state when the formation flow rate is equal to the drawdown rate. PSSDD permeability is calculated from Darcy's equation with the stabilized (maximum) pressure drop and the flowrate resulting from the piston withdrawal:9–11 $$k {d}=1754.5\left({q\mu \over r {i}\Delta p {{\rm max}}}\right),\eqno ({\rm 1})$$where kd=PSSDD permeability, md. The other parameters are given in Nomenclature.

INTERPRETATION IN FOREIGN LANGUAGES EDUCATION: PSYCHOLOGICAL ASPECT

2021 ◽  
Vol 54 (2) ◽  
pp. 121-129
Author(s):  
Vera B. Tsarcova ◽  
Keyword(s):  
Foreign Language ◽  
Real World ◽  
Language Education ◽  
Foreign Language Education ◽  
Educational Process ◽  
Personal Meanings ◽  
The Subject ◽  
Definition Of ◽  
Educational Potential

The article is devoted to one of the problems of foreign language education – the definition of the role of interpretation in preparing students of special (language) directions to participate in the dialogue of cultures. Interpretation is considered as a phenomenon and as a way of comprehending reality, which allows the subjects of the dialogue of cultures to reach mutual understanding. The main characteristic of interpretation, which is necessary for the purposes of foreign language education, is its psychological character. It is determined by the psychology of the author, the psychology of the work, as well as the psychology of the reader-interpreter. It is proved that the interpretation of a work of art, which has universal, historical and personal plans, has huge epistemological and axiological possibilities. They activate the entire educational potential of interperetation (educational, developmental, cognitive, and educational). Russian Russian poet A. A. Fet (1820–1892) uses the poem “Wir saßen am Fischerhaus” by the famous German poet and publicist Heinrich Hein (1797–1856) and the translation of this poem into Russian to illustrate the interpretation technology. The poem is considered as a space of personal meanings of the author. They are the ones that are subject to interpretation and bring the reader-interpreter back from the poet's world to the modern real world. And the real world is full of unexpected cultural facts, closely related to the content of the work of G. Heine, with distant Lapland and the life of modern lapps. Thus, interpretation is presented as an educational strategy. Together with the strategies of contextualization, philologization and argumentation, it ensures the achievement of the main goal of foreign language education – the creation of an individual who can act as a genuine subject of the dialogue of cultures. The article also emphasizes the importance of the teacher as the organizer of the educational process and the subject of the dialogue of cultures.

SOCIOLOGICAL PROBLEMS OF RITUAL: SOME REFLECTIONS

2021 ◽  
Vol 74 (2) ◽  
pp. 67-71
Author(s):  
Zh.K. Madalieva ◽  
Keyword(s):  
Social Action ◽  
Real World ◽  
Symbolic Meaning ◽  
Traditional Society ◽  
Social Functions ◽  
Individual Life ◽  
Human Community ◽  
The Social ◽  
The World ◽  
Definition Of

The article discusses in detail the essence and meaning of ritual as a social action. The study of the nature of this phenomenon involves, first of all, the study of various approaches to the definition of the concept of "ritual" and related phenomena. Analyzing the existing definitions, the author comes to the conclusion that "ritual" is a certain set of actions that have symbolic meaning. The symbolism of the ritual is manifested in its connecting role with the world of the sacred, sacred. The article emphasizes that in the consciousness of a person in a traditional society, the sacred world is present in the real world through ritual. As an archaic form of culture, ritual was also a way of regulating and maintaining collective life. The ritual served as a means of integrating and maintaining the integrity of the human community, giving it stability. Therefore, the article focuses on the social functions of the ritual in both public and individual life.

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