Heterotypic Scaffold Design Orchestrates Primary Cell Organization and Phenotypes in Cocultured Small Diameter Vascular Grafts

To facilitate true regeneration, a vascular graft should direct the evolution of a neovessel to obtain the function of a native vessel. For this, scaffolds have to permit the formation of an intraluminal endothelial cell monolayer, mimicking the tunica intima. In addition, when attempting to mimic a tunica media‐like outer layer, the stacking and orientation of vascular smooth muscle cells (vSMCs) should be recapitulated. An integral scaffold design that facilitates this has so far remained a challenge. A hybrid fabrication approach is introduced by combining solution electrospinning and melt electrowriting. This allows a tissue‐structure mimetic, hierarchically bilayered tubular scaffold, comprising an inner layer of randomly oriented dense fiber mesh and an outer layer of microfibers with controlled orientation. The scaffold supports the organization of a continuous luminal endothelial monolayer and oriented layers of vSM‐like cells in the media, thus facilitating control over specific and tissue‐mimetic cellular differentiation and support of the phenotypic morphology in the respective layers. Neither soluble factors nor a surface bioactivation of the scaffold is needed with this approach, demonstrating that heterotypic scaffold design can direct physiological tissue‐like cell organization and differentiation.     

Probabilistic Length-Reducing Two-Pushdown Automata

Hardness of a separation of nondeterminism, randomization and determinism for polynomial time computations has motivated the analysis of this issue for restricted models of computation. Following this line of research, we consider randomized length-reducing two-pushdown automata ( ), a natural extension of pushdown automata ( ). Our main results are as follows. We show that deterministic s are weaker than Las Vegas s which in turn are weaker than Monte Carlo s. Moreover, bounded two-sided error s are stronger than Monte Carlo s and they are able to recognize some languages which cannot be recognized nondeterministically. Finally, we prove that amplification is impossible for Las Vegas and Monte Carlo automata. Partially supported by MNiSW grant number N206 024 31/3826, 2006-2008. An extended abstract of this paper appeared in the MFCS06 Proceedings (Lecture Notes in Computer Science, vol. 4162, pp. 561–572, 2006).     

Using derivatives in time series classification

Over recent years the popularity of time series has soared. Given the widespread use of modern information technology, a large number of time series may be collected during business, medical or biological operations, for example. As a consequence there has been a dramatic increase in the amount of interest in querying and mining such data, which in turn has resulted in a large number of works introducing new methodologies for indexing, classification, clustering and approximation of time series. In particular, many new distance measures between time series have been introduced. In this paper, we propose a new distance function based on a derivative. In contrast to well-known measures from the literature, our approach considers the general shape of a time series rather than point-to-point function comparison. The new distance is used in classification with the nearest neighbor rule. In order to provide a comprehensive comparison, we conducted a set of experiments, testing effectiveness on 20 time series datasets from a wide variety of application domains. Our experiments show that our method provides a higher quality of classification on most of the examined datasets.     

A real‐time field experiment on search and rescue operations assisted by unmanned aerial vehicles

This paper reports on the performance of a novel system for supporting search and rescue activities, known as SARUAV (search and rescue unmanned aerial vehicle), in a field experiment during which a real‐world search scenario was simulated. The experiment took place on March 2–3, 2017, at two sites located in southwestern Poland. Three groups acted in the experiment: (1) SARUAV and unmanned aerial vehicle (UAV) operators, (2) ground searchers, and (3) participants who simulated being lost. In the uncomplicated topography without snow cover, the system identified the lost persons, and ground searchers found them 31 min after the SARUAV report had been disseminated. In the mountainous area covered with snow, one person was found within 9 min after searchers received the SARUAV report; however, the other two persons were not identified by SARUAV. The field experiment served as a proof of concept of the SARUAV system, confirmed its potential in person identification studies, and helped to identify numerous scientific and technical problems that need to be solved to develop a mature version of the system.     

Real-time hardware–software embedded vision system for ITS smart camera implemented in Zynq SoC

The article demonstrates the usefulness of heterogeneous System on Chip (SoC) devices in smart cameras used in intelligent transportation systems (ITS). In a compact, energy efficient system the following exemplary algorithms were implemented: vehicle queue length estimation, vehicle detection, vehicle counting and speed estimation (using multiple virtual detection lines), as well as vehicle type (local binary features and SVM classifier) and colour (k-means classifier and YCbCr colourspace analysis) recognition. The solution exploits the hardware–software architecture, i.e. the combination of reconfigurable resources and the efficient ARM processor. Most of the modules were implemented in hardware, using Verilog HDL, taking full advantage of the possible parallelization and pipeline, which allowed to obtain real-time image processing. The ARM processor is responsible for executing some parts of the algorithm, i.e. high-level image processing and analysis, as well as for communication with the external systems (e.g. traffic lights controllers). The demonstrated results indicate that modern SoC systems are a very interesting platform for advanced ITS systems and other advanced embedded image processing, analysis and recognition applications.     

An object-oriented C++ implementation of Davidson method for finding a few selected extreme eigenpairs of a large, sparse, real, symmetric matrix

A C++ class named Davidson is presented for determining a few eigenpairs with lowest or alternatively highest values of a large, real, symmetric matrix. The algorithm described by Stathopoulos and Fischer is used. The exception mechanism is involved to report the errors. The class is written in ANSI C++, so it is fully portable. In addition a console program as well as a program with graphical user interface for Microsoft Windows is attached, which allow one to calculate the lowest eigenstates of time-independent Schrödinger equation for a given binding potential in one, two or three spatial dimensions. The package contains the classes providing often used potential functions (model atom potential, Coulomb potential, square well potential and Kramers-Henneberger well potential) as well as a possibility to use any potential stored in a file (then any dimensionality of the problem is allowed).The described code is the subject of M.Sc. thesis of T.D. prepared under the supervision of J.M.

Program summary

Program title: DavidsonCatalogue identifier: ADZM_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZM_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 3 037 055No. of bytes in distributed program, including test data, etc.: 20 002 609Distribution format: tar.gzProgramming language: C++Computer: AllOperating system: AnyRAM: User's parameters dependentWord size: 32 and 64 bitsSupplementary material: Test results for the 2D and 3D cases is availableClassification: 4, 4.8Nature of problem: Finding a few extreme eigenpairs of a real, symmetric, sparse matrix. Examples in quantum optics (interaction of matter with a laser field).Solution method: Davidson algorithmRunning time: The test example included in the distribution package (1D matrix) takes approximately 30 minutes to run. 2D matrix calculations can take hours and 3D, days, to run.     

Fine polymer imprinted layers for the monitoring of bisphenol A in aqueous solutions

The present work proposes the use of molecularly imprinted polymer layers (MIPLs) on dehydrochlorinated poly(vinyl chloride) (DHPVC) particles, which could serve as new materials for the separation of bisphenol A (BPA). The best material with MIPLs was obtained using a mixture of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) with the molar ratio of 4:6 in n-octane as the solvent and with 7 wt.% of BPA, which were grafted onto DHPVC particles. The synthesized materials were investigated for their possible application in the monitoring of BPA contamination in real samples received after the treatment of can of some popular beverages.     

Wind and Fire Coupled Modelling—Part II: Good Practice Guidelines

The requirement to model wind is inherently connected with the modelling of many fire-related phenomena. With its defining influence on fire behaviour, spread and smoke transport, the solution of a problem with and without wind exposure will lead to substantially different results. As wind and fire are phenomena that often require different scales of analysis and approaches to modelling, their coupling is not a trivial task. This paper is the second part of a two-paper review of the coupling between fire safety engineering and computational wind engineering (CWE). Part I contained a review of historical interactions between these disciplines, sorted into six distinct areas: flames, indoor flows, natural ventilators, tunnels, wildfires and urban smoke dispersion. This part of the review contains practical information related to wind modelling in fire analysis, based on various available CWE best practice guidelines. As the authors conclude, the most relevant of these are guidelines related to urban physics and natural ventilation; however, many more are discussed and presented, together with the results of other essential wind engineering experiments and computations. Introduction of wind as a boundary condition is explained in details, both based on wind statistics, or meso/micro scale coupled modelling. The guidelines for wind/fire coupled analyses are subdivided into recommendations for: building the digital domain, spatial and temporal discretisation, the consequences of the choice of a turbulent flow model, and the procedure for optimising CFD analysis of both wind and fire phenomena.