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Showing papers by "University of Maribor published in 2016"


Journal ArticleDOI
TL;DR: This report reviews the developmental arc of theoretical epidemiology with emphasis on vaccination, as it led from classical models assuming homogeneously mixing populations and ignoring human behavior, to recent models that account for behavioral feedback and/or population spatial/social structure.

789 citations


Journal ArticleDOI
TL;DR: One of the promising solutions lies in nanoformulation of polyphenols that prevents their degradation and thus enables significantly higher concentrations to reach the target cells, resulting in lowering of the required therapeutic dose and in multitargeted action.
Abstract: Being secondary plant metabolites, polyphenols represent a large and diverse group of substances abundantly present in a majority of fruits, herbs and vegetables. The current contribution is focused on their bioavailability, antioxidative and anticarcinogenic properties. An overview of extraction methods is also given, with supercritical fluid extraction highlighted as a promising eco-friendly alternative providing exceptional separation and protection from degradation of unstable polyphenols. The protective role of polyphenols against reactive oxygen and nitrogen species, UV light, plant pathogens, parasites and predators results in several beneficial biological activities giving rise to prophylaxis or possibly even to a cure for several prevailing human diseases, especially various cancer types. Omnipresence, specificity of the response and the absence of or low toxicity are crucial advantages of polyphenols as anticancer agents. The main problem represents their low bioavailability and rapid metabolism. One of the promising solutions lies in nanoformulation of polyphenols that prevents their degradation and thus enables significantly higher concentrations to reach the target cells. Another, more practiced, solution is the use of mixtures of various polyphenols that bring synergistic effects, resulting in lowering of the required therapeutic dose and in multitargeted action. The combination of polyphenols with existing drugs and therapies also shows promising results and significantly reduces their toxicity.

638 citations


Journal ArticleDOI
01 Jan 2016
TL;DR: This paper focuses on overcoming the security weaknesses of Turkanovic et?al.'s scheme, by proposing a new and improved UAKAS which enables the same functionality but improves the security level and enables the HWSN to dynamically grow without influencing any party involved in the UAKas.
Abstract: The concept of Internet of Things (IOT), which is already at our front doors, is that every object in the Internet infrastructure (II) is interconnected into a global dynamic expanding network. Sensors and smart objects are beside classical computing devices key parties of the IOT. We can already exploit the benefits of the IOT by using various weareables or smart phones which are full of diverse sensors and actuators and are connected to the II via GPRS or Wi-Fi. Since sensors are a key part of IOT, thus are wireless sensor networks (WSN). Researchers are already working on new techniques and efficient approaches on how to integrate WSN better into the IOT environment. One aspect of it is the security aspect of the integration. Recently, Turkanovic et?al.'s proposed a highly efficient and novel user authentication and key agreement scheme (UAKAS) for heterogeneous WSN (HWSN) which was adapted to the IOT notion. Their scheme presented a novel approach where a user from the IOT can authenticate with a specific sensor node from the HWSN without having to communicate with a gateway node. Moreover their scheme is highly efficient since it is based on a simple symmetric cryptosystem. Unfortunately we have found that Turkanovic et?al.'s scheme has some security shortcomings and is susceptible to some cryptographic attacks. This paper focuses on overcoming the security weaknesses of Turkanovic et?al.'s scheme, by proposing a new and improved UAKAS. The proposed scheme enables the same functionality but improves the security level and enables the HWSN to dynamically grow without influencing any party involved in the UAKAS. The results of security analysis by BAN-logic and AVISPA tools confirm the security properties of the proposed scheme.

401 citations


Journal ArticleDOI
TL;DR: These results show that the method provides a solid framework for the decomposition of multi-channel invasive and non-invasive EMG signals that allows the study of the behavior of a large number of concurrently active motor units.
Abstract: Objective. The study of motor unit behavior has been classically performed by selective recording systems of muscle electrical activity (EMG signals) and decomposition algorithms able to discriminate between individual motor unit action potentials from multi-unit signals. In this study, we provide a general framework for the decomposition of multi-channel intramuscular and surface EMG signals and we extensively validate this approach with experimental recordings. Approach. First, we describe the conditions under which the assumptions of the convolutive blind separation model are satisfied. Second, we propose an approach of convolutive sphering of the observations followed by an iterative extraction of the sources. This approach is then validated using intramuscular signals recorded by novel multi-channel thin-film electrodes on the Abductor Digiti Minimi of the hand and Tibilias Anterior muscles, as well as on high-density surface EMG signals recorded by electrode grids on the First Dorsal Interosseous muscle. The validation was based on the comparison with the gold standard of manual decomposition (for intramuscular recordings) and on the two-source method (for comparison of intramuscular and surface EMG recordings) for the three human muscles and contraction forces of up to 90% MVC. Main results. The average number of common sources identified for the validation was 14 ± 7 (averaged across all trials and subjects and all comparisons), with a rate of agreement in their discharge timings of 92.8 ± 3.2%. The average Decomposability Index, calculated on the automatic decomposed signals, was 16.0 ± 2.2 (7.3–44.1). For comparison, the same index calculated on the manual decomposed signals was 15.0 ± 3.0 (6.3–76.6). Significance. These results show that the method provides a solid framework for the decomposition of multi-channel invasive and non-invasive EMG signals that allows the study of the behavior of a large number of concurrently active motor units.

378 citations


Journal ArticleDOI
TL;DR: In this paper, the authors constructed the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions.
Abstract: We construct the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions. This specific model ensures that the dual theory has a well defined ultraviolet completion in terms of a two dimensional conformal field theory, but our results apply qualitatively to a wider class of two dimensional dilaton gravity theories. For each type of solutions we perform holographic renormalization, compute the exact renormalized one-point functions in the presence of arbitrary sources, and derive the asymptotic symmetries and the corresponding conserved charges. In both cases we find that the scalar operator dual to the dilaton plays a crucial role in the description of the dynamics. Its source gives rise to a matter conformal anomaly for the running dilaton solutions, while its expectation value is the only non trivial observable for constant dilaton solutions. The role of this operator has been largely overlooked in the literature. We further show that the only non trivial conserved charges for running dilaton solutions are the mass and the electric charge, while for constant dilaton solutions only the electric charge is non zero. However, by uplifting the solutions to three dimensions we show that constant dilaton solutions can support non trivial extended symmetry algebras, including the one found by Compere, Song and Strominger [1], in agreement with the results of Castro and Song [2]. Finally, we demonstrate that any solution of this specific dilaton gravity model can be uplifted to a family of asymptotically AdS2 × S 2 or conformally AdS2 × S 2 solutions of the STU model in four dimensions, including non extremal black holes. The four dimensional solutions obtained by uplifting the running dilaton solutions coincide with the so called ‘subtracted geometries’, while those obtained from the uplift of the constant dilaton ones are new.

248 citations


Journal ArticleDOI
TL;DR: A review of the public goods game can be found in this article, with an emphasis on merging the most recent advances in the social sciences with methods of nonequilibrium statistical physics.

238 citations


Journal ArticleDOI
TL;DR: In this paper, the authors summarize the research work reported in the last two decades on the use of organic corrosion inhibitors for aluminum and its alloys in different alkaline (mainly NaOH and KOH) and chloride solutions.

206 citations


Journal ArticleDOI
TL;DR: In this article, the authors studied the existence of chimera states in a network of neurons without any direct interactions but connected through another medium of neurons, forming a multilayer structure.
Abstract: Spatial coexistence of coherent and incoherent dynamics in network of coupled oscillators is called a chimera state. We study such chimera states in a network of neurons without any direct interactions but connected through another medium of neurons, forming a multilayer structure. The upper layer is thus made up of uncoupled neurons and the lower layer plays the role of a medium through which the neurons in the upper layer share information among each other. Hindmarsh-Rose neurons with square wave bursting dynamics are considered as nodes in both layers. In addition, we also discuss the existence of chimera states in presence of inter layer heterogeneity. The neurons in the bottom layer are globally connected through electrical synapses, while across the two layers chemical synapses are formed. According to our research, the competing effects of these two types of synapses can lead to chimera states in the upper layer of uncoupled neurons. Remarkably, we find a density-dependent threshold for the emergence of chimera states in uncoupled neurons, similar to the quorum sensing transition to a synchronized state. Finally, we examine the impact of both homogeneous and heterogeneous inter-layer information transmission delays on the observed chimera states over a wide parameter space.

187 citations


Journal ArticleDOI
TL;DR: A review of the potential of aerogels in biomedical applications can be found in this paper, where a short introduction is made to the common aerogel properties and their possible classification options, and the review is structured based on their possible biomedical applications.
Abstract: Due to their many excellent properties, aerogels attract much interest in various applications, ranging from construction to medicine. Over the last decades, their potential was practically exploited only in non-medical fields of use, although many aerogel materials, either organic, inorganic or hybrid, were proven biocompatible. Some aerogel compositions have been patented at the verge of the millennium, but the clinical use of aerogels remains very limited. This review intends to shed some more light in regard to their potential in biomedical applications as can be deduced from the more recent progressive research of their capabilities in regard to different compositions. The review covers many recent studies, but includes older research that significantly affected the development of aerogel-based materials over the years, as well. After a short introduction, covering the common aerogel properties and their possible classification options, the review is structured based on their different possible biomedical applications. Finally, it focuses on the potential of aerogels in regenerative medicine.

186 citations


Journal ArticleDOI
TL;DR: In this paper, the authors provide an overview of the state-of-the-art of the auxetic materials, their development, most common geometries, fabrication methods, mechanical properties, applications and further possibilities for their development.
Abstract: Auxetic cellular materials are modern materials which have some unique and superior mechanical properties. As a consequence of the structural deformation of their internal cellular structure they exhibit a negative Poisson’s ratio, i.e. they significantly increase in volume when stretched and vice versa. The effect of negative Poisson’s ratio is useful in many applications to enhance certain physical properties such as the density, stiffness, fracture toughness, energy absorption and damping. These properties can be further tailored by using variable cell geometry and density distribution, which can be achieved with functionally graded porosity of auxetic materials. This review paper provides the state-of-the-art overview of the auxetic materials, their development, most common geometries, fabrication methods, mechanical properties, applications and further possibilities for their development.

165 citations


Journal ArticleDOI
TL;DR: Irrespective of the type of autapse, autaptic time delay induced multiple coherence resonance for appropriately tuned autaptic conductance levels in single neurons and scale-free neuronal networks is observed, showing that in the presence of an electrical autapse there is an optimal intensity of channel noise inducing the multiple coherent resonance.
Abstract: We study the effects of electrical and chemical autapse on the temporal coherence or firing regularity of single stochastic Hodgkin-Huxley neurons and scale-free neuronal networks. Also, we study the effects of chemical autapse on the occurrence of spatial synchronization in scale-free neuronal networks. Irrespective of the type of autapse, we observe autaptic time delay induced multiple coherence resonance for appropriately tuned autaptic conductance levels in single neurons. More precisely, we show that in the presence of an electrical autapse, there is an optimal intensity of channel noise inducing the multiple coherence resonance, whereas in the presence of chemical autapse the occurrence of multiple coherence resonance is less sensitive to the channel noise intensity. At the network level, we find autaptic time delay induced multiple coherence resonance and synchronization transitions, occurring at approximately the same delay lengths. We show that these two phenomena can arise only at a specific range of the coupling strength, and that they can be observed independently of the average degree of the network.

Journal ArticleDOI
TL;DR: The statistical findings regarding research questions paint an interesting picture about the mainstreams of the DSL community, as well as open issues where researchers can improve their research in their future work.
Abstract: Context: In this study we report on a Systematic Mapping Study (SMS) for Domain-Specific Languages (DSLs), based on an automatic search including primary studies from journals, conferences, and workshops during the period from 2006 until 2012.Objective: The main objective of the described work was to perform an SMS on DSLs to better understand the DSL research field, identify research trends, and any possible open issues. The set of research questions was inspired by a DSL survey paper published in 2005.Method: We conducted a SMS over 5 stages: defining research questions, conducting the search, screening, classifying, and data extraction. Our SMS included 1153 candidate primary studies from the ISI Web of Science and ACM Digital Library, 390 primary studies were classified after screening.Results: This SMS discusses two main research questions: research space and trends/demographics of the literature within the field of DSLs. Both research questions are further subdivided into several research sub-questions. The results from the first research question clearly show that the DSL community focuses more on the development of new techniques/methods rather than investigating the integrations of DSLs with other software engineering processes or measuring the effectiveness of DSL approaches. Furthermore, there is a clear lack of evaluation research. Amongst different DSL development phases more attention is needed in regard to domain analysis, validation, and maintenance. The second research question revealed that the number of publications remains stable, and has not increased over the years. Top cited papers and venues are mentioned, as well as identifying the more active institutions carrying DSL research.Conclusion: The statistical findings regarding research questions paint an interesting picture about the mainstreams of the DSL community, as well as open issues where researchers can improve their research in their future work.

Journal ArticleDOI
R. Glattauer1, C. Schwanda1, A. Abdesselam2, I. Adachi  +177 moreInstitutions (58)
TL;DR: In this article, the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar was determined based on 711 fb(-1) of e(+)e(-) -> Upsilon(4S) data recorded by the Belle detector and containing 772 x 10(6) B (B) over bar pairs.
Abstract: We present a determination of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar using the decay B -> Dl nu(l) (l = e,mu) based on 711 fb(-1) of e(+)e(-) -> Upsilon(4S) data recorded by the Belle detector and containing 772 x 10(6) B (B) over bar pairs. One B meson in the event is fully reconstructed in a hadronic decay mode, while the other, on the signal side, is partially reconstructed from a charged lepton and either a D+ or D-0 meson in a total of 23 hadronic decay modes. The isospin-averaged branching fraction of the decay B -> Dl nu(l) is found to be B(B-0 -> D(-)l(vertical bar)nu(l)) = (2.31 +/- 0.03(stat) +/- 0.11(syst))%. Analyzing the differential decay rate as a function of the hadronic recoil with the parametrization of Caprini, Lellouch, and Neubert and using the form-factor prediction G(1) = 1.0541 +/- 0.0083 calculated by FNAL/MILC, we obtain eta(EW)vertical bar V-cb vertical bar = (40.12 +/- 1.34) x 10(-3), where eta(EW) is the electroweak correction factor. Alternatively, assuming the model-independent form-factor parametrization of Boyd, Grinstein, and Lebed and using lattice QCD data from the FNAL/MILC and HPQCD collaborations, we find eta(EW)vertical bar V-cb vertical bar = (41.10 +/- 1.14) x 10(-3).

Journal ArticleDOI
TL;DR: In this paper, the authors proposed to extend the Unified Theory of Acceptance and Use of Technology (UTAUT) with a new moderator variable user type in order to investigate differences in the UTAUT determinants between pre- and post-adopters of IWBs.

Proceedings ArticleDOI
24 Jul 2016
TL;DR: An improved version of the well-known L-SHADE algorithm for solving single objective real-parameter optimization problems and results show that the algorithm performs highly competitive in comparison with the original L- SHADE algorithm.
Abstract: In this paper we present a differential evolution algorithm (iL-SHADE) for solving single objective real-parameter optimization problems. It is an improved version of the well-known L-SHADE algorithm. The experimental results of our algorithm are presented on CEC 2014 benchmark functions. The experiments were performed on 30 benchmark functions and on four different dimensions. The obtained results show that our algorithm performs highly competitive in comparison with the original L-SHADE algorithm.

Journal ArticleDOI
TL;DR: Findings suggest that organizational barriers such as culture, the reporting system and management behaviour in addition to personal and professional barrierssuch as fear, accountability and characteristics of nurses are barriers to reporting medication errors.

Journal ArticleDOI
19 Jan 2016
TL;DR: An overview of processing methods of the surface EMG signal that allow a reliable characterization of individual motor units in vivo in humans is provided.
Abstract: Motor units are the smallest functional units of our movements. The study of their activation provides a window into the mechanisms of neural control of movement in humans. The classic methods for motor unit investigations date to several decades ago. They are based on invasive recordings with selective needle or wire electrodes. Conversely, the noninvasive (surface) EMG has been commonly processed as an interference signal, with the extraction of its global characteristics, e.g., amplitude. These characteristics, however, are only crudely associated to the underlying motor unit activities. In the last decade, methods have been proposed for reliably extracting individual motor unit activities from the interference surface EMG signal. We describe these methods in this review, with a focus on blind source separation (BSS) and techniques used on decomposed EMG signals. For example, from the motor unit discharge timings, information can be extracted regarding the synaptic input received by the corresponding motor neurons. In reviewing these methods, we also provide examples of applications in representative conditions, such as pathological tremor. In conclusion, we provide an overview of processing methods of the surface EMG signal that allow a reliable characterization of individual motor units in vivo in humans.

Journal ArticleDOI
TL;DR: In this paper, the authors studied the existence of chimera states in a network of neurons without any direct interactions but connected through another medium of neurons, forming a multilayer structure.
Abstract: Spatial coexistence of coherent and incoherent dynamics in network of coupled oscillators is called a chimera state. We study such chimera states in a network of neurons without any direct interactions but connected through another medium of neurons, forming a multilayer structure. The upper layer is thus made up of uncoupled neurons and the lower layer plays the role of a medium through which the neurons in the upper layer share information among each other. Hindmarsh-Rose neurons with square wave bursting dynamics are considered as nodes in both layers. In addition, we also discuss the existence of chimera states in presence of inter layer heterogeneity. The neurons in the bottom layer are globally connected through electrical synapses, while across the two layers chemical synapses are formed. According to our research, the competing effects of these two types of synapses can lead to chimera states in the upper layer of uncoupled neurons. Remarkably, we find a density-dependent threshold for the emergence of chimera states in uncoupled neurons, similar to the quorum sensing transition to a synchronized state. Finally, we examine the impact of both homogeneous and heterogeneous inter-layer information transmission delays on the observed chimera states over a wide parameter space.

Journal ArticleDOI
TL;DR: It is shown that the diversity of tolerance can give rise to synergistic effects, wherein players with a different threshold in terms of the tolerated number of defectors in a group compete most effectively against defection and default abstinence.
Abstract: Tolerance implies enduring trying circumstances with a fair and objective attitude. To determine whether evolutionary advantages might be stemming from diverse levels of tolerance in a population, we study a spatial public goods game, where in addition to cooperators, defectors, and loners, tolerant players are also present. Depending on the number of defectors within a group, a tolerant player can either cooperate in or abstain from a particular instance of the game. We show that the diversity of tolerance can give rise to synergistic effects, wherein players with a different threshold in terms of the tolerated number of defectors in a group compete most effectively against defection and default abstinence. Such synergistic associations can stabilise states of full cooperation where otherwise defection would dominate. We observe complex pattern formation that gives rise to an intricate phase diagram, where invisible yet stable strategy alliances require outmost care lest they are overlooked. Our results highlight the delicate importance of diversity and tolerance for the provisioning of public goods, and they reveal fascinating subtleties of the spatiotemporal dynamics that is due to the competition of subsystem solutions in structured populations.

Journal ArticleDOI
TL;DR: There is a need for mobile apps for self-management of diabetes with more features in order to increase the number of long-term users and thus influence better self- management of the disease.
Abstract: Mobile applications (apps) can be very useful software on smartphones for all aspects of people's lives. Chronic diseases, such as diabetes, can be made manageable with the support of mobile apps. Applications on smartphones can also help people with diabetes to control their fitness and health. A systematic review of free apps in the English language for smartphones in three of the most popular mobile app stores: Google Play (Android), App Store (iOS) and Windows Phone Store, was performed from November to December 2015. The review of freely available mobile apps for self-management of diabetes was conducted based on the criteria for promoting diabetes self-management as defined by Goyal and Cafazzo (monitoring blood glucose level and medication, nutrition, physical exercise and body weight). The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) was followed. Three independent experts in the field of healthcare-related mobile apps were included in the assessment for eligibility and testing phase. We tested and evaluated 65 apps (21 from Google Play Store, 31 from App Store and 13 from Windows Phone Store). Fifty-six of these apps did not meet even minimal requirements or did not work properly. While a wide selection of mobile applications is available for self-management of diabetes, current results show that there are only nine (5 from Google Play Store, 3 from App Store and 1 from Windows Phone Store) out of 65 reviewed mobile apps that can be versatile and useful for successful self-management of diabetes based on selection criteria. The levels of inclusion of features based on selection criteria in selected mobile apps can be very different. The results of the study can be used as a basis to prvide app developers with certain recommendations. There is a need for mobile apps for self-management of diabetes with more features in order to increase the number of long-term users and thus influence better self-management of the disease.

Journal ArticleDOI
TL;DR: In this paper, an analytical travel time model for the computation of cycle times for double-deep SBS/RS is presented, which considers the real operating characteristics of the elevators lifting table and the shuttle carrier with the condition of rearranging blocking totes to the nearest free storage location during the retrieval process of the carrier.
Abstract: Technological developments in the global supply chain have changed processes in warehousing. This reflects in short response time in handling the orders, which has a consequence on high automation degree in warehousing. An important part of automated warehouses is presented by shuttle-based storage and retrieval systems (SBS/RS), which are used in practice when demand for the throughput capacity is high. In this paper, analytical travel time model for the computation of cycle times for double-deep SBS/RS is presented. The advantage of the double-deep SBS/RS is that fewer aisles are needed, which results in a more efficient use of floor space. The proposed model considers the real operating characteristics of the elevators lifting table and the shuttle carrier with the condition of rearranging blocking totes to the nearest free storage location during the retrieval process of the shuttle carrier. Assuming uniform distributed storage locations and the probability theory, the expressions for the single and d...

Journal ArticleDOI
TL;DR: In recent years, a great deal of interest has been focused on the development of novel atomic force microscopy (AFM)-based methods as mentioned in this paper, which is the perfect tool for the study of phenomena at the nanoscale, which includes quantitative single molecule studies.
Abstract: In recent years, a great deal of interest has been focused on the development of novel atomic force microscopy (AFM)-based methods. From first being an unstable method, AFM has emerged as the perfect tool for the study of phenomena at the nanoscale, which includes quantitative single molecule studies. Numerous novel AFM methods play a crucial role in the invention of novel drugs, their delivery systems, based on either polymers or inorganic/metallic matrices, and in the examination of disease-related tissue changes. Such contemporary progressive studies are a perfect example of interdisciplinary research, which results in exemplary findings and discoveries. This review focuses especially on the literature published in the last decade; however the most important earlier discoveries are also included.

Journal ArticleDOI
TL;DR: In this article, the authors studied the effects of an autapse on the propagation of weak, localized pacemaker activity across a Newman-Watts small-world network consisting of stochastic Hodgkin-Huxley neurons.
Abstract: We study the effects of an autapse, which is mathematically described as a self-feedback loop, on the propagation of weak, localized pacemaker activity across a Newman–Watts small-world network consisting of stochastic Hodgkin–Huxley neurons. We consider that only the pacemaker neuron, which is stimulated by a subthreshold periodic signal, has an electrical autapse that is characterized by a coupling strength and a delay time. We focus on the impact of the coupling strength, the network structure, the properties of the weak periodic stimulus, and the properties of the autapse on the transmission of localized pacemaker activity. Obtained results indicate the existence of optimal channel noise intensity for the propagation of the localized rhythm. Under optimal conditions, the autapse can significantly improve the propagation of pacemaker activity, but only for a specific range of the autaptic coupling strength. Moreover, the autaptic delay time has to be equal to the intrinsic oscillation period of the Hodgkin–Huxley neuron or its integer multiples. We analyze the inter-spike interval histogram and show that the autapse enhances or suppresses the propagation of the localized rhythm by increasing or decreasing the phase locking between the spiking of the pacemaker neuron and the weak periodic signal. In particular, when the autaptic delay time is equal to the intrinsic period of oscillations an optimal phase locking takes place, resulting in a dominant time scale of the spiking activity. We also investigate the effects of the network structure and the coupling strength on the propagation of pacemaker activity. We find that there exist an optimal coupling strength and an optimal network structure that together warrant an optimal propagation of the localized rhythm.

Journal ArticleDOI
TL;DR: A novel hybrid differential evolution algorithm for selecting the optimal threshold values for a given gray-level input image, using the criterion defined by Otsu, which shows superior performance in the quality of the results.
Abstract: Real test images were used to perform thresholding using Otsu's method with a high level of thresholds.The proposed hybrid is compared with DE, jDE, PSO, ABC, and CS.Algorithms are compared based on PSNR and SSIM metrics.Friedman and Wilcoxon statistical tests are used to show the performances.Proposed hjDE shows superior performance in the quality of the results. Image thresholding is a process for separating interesting objects within an image from their background. An optimal threshold's selection can be regarded as a single objective optimization problem, where obtaining a solution can be computationally expensive and time-consuming, especially when the number of thresholds increases greatly. This paper proposes a novel hybrid differential evolution algorithm for selecting the optimal threshold values for a given gray-level input image, using the criterion defined by Otsu. The hybridization is done by adding a reset strategy, adopted from the Cuckoo Search, within the evolutionary loop of differential evolution. Additionally a study of different evolutionary or swarm-based intelligence algorithms for the purpose of thresholding, with a higher number of thresholds was performed, since many real-world applications require more than just a few thresholds for further processing. Experiments were performed on eleven real world images. The efficiency of the hybrid was compared to the cuckoo search and self-adaptive differential evolution, the original differential evolution, particle swarm optimization, and artificial bee colony where the results showed the superiority of the hybrid in terms of better segmentation results with the increased number of thresholds. Since the proposed method needs only two parameters adjusted, it is by far a better choice for real-life applications.

Journal ArticleDOI
TL;DR: A novel hybrid self-adaptive cuckoo search algorithm is proposed, which extends the original cuckOO search by adding three features, i.e., a balancing of the exploration search strategies within the cuckoff search algorithm, a self- Adaptation of cuckoos search control parameters and a linear population reduction.
Abstract: Adaptation and hybridization typically improve the performances of original algorithm. This paper proposes a novel hybrid self-adaptive cuckoo search algorithm, which extends the original cuckoo search by adding three features, i.e., a balancing of the exploration search strategies within the cuckoo search algorithm, a self-adaptation of cuckoo search control parameters and a linear population reduction. The algorithm was tested on 30 benchmark functions from the CEC-2014 test suite, giving promising results comparable to the algorithms, like the original differential evolution (DE) and original cuckoo search (CS), some powerful variants of modified cuckoo search (i.e., MOCS, CS-VSF) and self-adaptive differential evolution (i.e., jDE, SaDE), while overcoming the results of a winner of the CEC-2014 competition L-Shade remains a great challenge for the future.

Journal ArticleDOI
TL;DR: In this paper, a spatial public goods game is studied, where in addition to cooperators, defectors, and loners, tolerant players are also present, depending on the number of defectors within a group, a tolerant player can either cooperate in or abstain from a particular instance of the game.
Abstract: Tolerance implies enduring trying circumstances with a fair and objective attitude. To determine whether evolutionary advantages might be stemming from diverse levels of tolerance in a population, we study a spatial public goods game, where in addition to cooperators, defectors, and loners, tolerant players are also present. Depending on the number of defectors within a group, a tolerant player can either cooperate in or abstain from a particular instance of the game. We show that the diversity of tolerance can give rise to synergistic effects, wherein players with a different threshold in terms of the tolerated number of defectors in a group compete most effectively against defection and default abstinence. Such synergistic associations can stabilise states of full cooperation where otherwise defection would dominate. We observe complex pattern formation that gives rise to an intricate phase diagram, where invisible yet stable strategy alliances require outmost care lest they are overlooked. Our results highlight the delicate importance of diversity and tolerance for the provisioning of public goods, and they reveal fascinating subtleties of the spatiotemporal dynamics that is due to the competition of subsystem solutions in structured populations.

Journal ArticleDOI
TL;DR: In this article, a review of the use of organic compounds as corrosion inhibitors for aluminium and its alloys in acidic solutions is presented, focusing on HCl and H2SO4 solutions due to their extensive use in different applications.
Abstract: The aim of this review is to summarise the research work published in the last two decades on the use of organic compounds as corrosion inhibitors for aluminium and its alloys in acidic solutions. The focus is on HCl and H2SO4 solutions due to their extensive use in different applications, such as chemical and electrochemical etching, acid cleaning, anodising, and acid pickling of aluminium. Other acids are also reviewed. The inhibition effectiveness of numerous organic compounds and their possible inhibition type and mechanism are also discussed. Electrochemistry is mainly used to investigate inhibitor performance.

Journal ArticleDOI
TL;DR: An overview of the 34 currently known toxinotypes (I to XXXIV) and some changes in nomenclature are described.
Abstract: Toxinotyping is a PCR-restriction fragment length polymorphism (RFLP)-based method for differentiation of Clostridium difficile strains according to the changes in the pathogenicity locus (PaLoc), a region coding for toxins A and B. Toxinotypes are a heterogenous group of strains that are important in the development of molecular diagnostic tests and vaccines and are a good basis for C. difficile phylogenetic studies. Here we describe an overview of the 34 currently known toxinotypes (I to XXXIV) and some changes in nomenclature.

Journal ArticleDOI
TL;DR: A comparison between CD subjects and Control group revealed an alteration in the intestinal microbial composition of coeliacs mainly characterized by a reduction of the Firmicutes/Bacteroidetes ratio, of Actinobacteria and Euryarchaeota, regarding the effects of the probiotic.
Abstract: Coeliac disease (CD) is associated with alterations of the intestinal microbiota. Although several Bifidobacterium strains showed anti-inflammatory activity and prevention of toxic gliadin peptides generation in vitro, few data are available on their efficacy when administered to CD subjects. This study evaluated the effect of administration for three months of a food supplement based on two Bifidobacterium breve strains (B632 and BR03) to restore the gut microbial balance in coeliac children on a gluten free diet (GFD). Microbial DNA was extracted from faeces of 40 coeliac children before and after probiotic or placebo administration and 16 healthy children (Control group). Sequencing of the amplified V3-V4 hypervariable region of 16S rRNA gene as well as qPCR of Bidobacterium spp., Lactobacillus spp., Bacteroides fragilis group Clostridium sensu stricto and enterobacteria were performed. The comparison between CD subjects and Control group revealed an alteration in the intestinal microbial composition of coeliacs mainly characterized by a reduction of the Firmicutes/Bacteroidetes ratio, of Actinobacteria and Euryarchaeota. Regarding the effects of the probiotic, an increase of Actinobacteria was found as well as a re-establishment of the physiological Firmicutes/Bacteroidetes ratio. Therefore, a three-month administration of B. breve strains helps in restoring the healthy percentage of main microbial components.

Journal ArticleDOI
TL;DR: This work investigates the effects of an autapse on the transmission of a weak localized pacemaker activity in a scale-free neuronal network and demonstrates the emergence of multiple resonances involving the weak signal, the intrinsic oscillations, and the time scale that is dictated by the autapse.
Abstract: An autapse is an unusual synapse that occurs between the axon and the soma of the same neuron. Mathematically, it can be described as a self-delayed feedback loop that is defined by a specific time-delay and the so-called autaptic coupling strength. Recently, the role and function of autapses within the nervous system has been studied extensively. Here, we extend the scope of theoretical research by investigating the effects of an autapse on the transmission of a weak localized pacemaker activity in a scale-free neuronal network. Our results reveal that by mediating the spiking activity of the pacemaker neuron, an autapse increases the propagation of its rhythm across the whole network, if only the autaptic time delay and the autaptic coupling strength are properly adjusted. We show that the autapse-induced enhancement of the transmission of pacemaker activity occurs only when the autaptic time delay is close to an integer multiple of the intrinsic oscillation time of the neurons that form the network. In particular, we demonstrate the emergence of multiple resonances involving the weak signal, the intrinsic oscillations, and the time scale that is dictated by the autapse. Interestingly, we also show that the enhancement of the pacemaker rhythm across the network is the strongest if the degree of the pacemaker neuron is lowest. This is because the dissipation of the localized rhythm is contained to the few directly linked neurons, and only afterwards, through the secondary neurons, it propagates further. If the pacemaker neuron has a high degree, then its rhythm is simply too weak to excite all the neighboring neurons, and propagation therefore fails.