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Bauer G.,Albert Ludwigs University of Freiburg | Zarkovic N.,Ruder Boskovic Institute | Zarkovic N.,University of Applied science
Free Radical Biology and Medicine | Year: 2015

Tumor cells generate extracellular superoxide anions and are protected against superoxide anion-mediated intercellular apoptosis-inducing signaling by the expression of membrane-associated catalase. 4-Hydroxy-2-nonenal (4-HNE), a versatile second messenger generated during lipid peroxidation, has been shown to induce apoptosis selectively in malignant cells. The findings described in this paper reveal the strong, concentration-dependent potential of 4-HNE to specifically inactivate extracellular catalase of tumor cells both indirectly and directly and to consequently trigger apoptosis in malignant cells through superoxide anion-mediated intercellular apoptosis-inducing signaling. Namely, 4-HNE caused apoptosis selectively in NOX1-expressing tumor cells through inactivation of their membrane-associated catalase, thus reactivating subsequent intercellular signaling through the NO/peroxynitrite and HOCl pathways, followed by the mitochondrial pathway of apoptosis. Concentrations of 4-HNE of 1.2 μM and higher directly inactivated membrane-associated catalase of tumor cells, whereas at lower concentrations, 4-HNE triggered a complex amplificatory pathway based on initial singlet oxygen formation through H2O2 and peroxynitrite interaction. Singlet-oxygen-dependent activation of the FAS receptor and caspase-8 increased superoxide anion generation by NOX1 and amplification of singlet oxygen generation, which allowed singlet-oxygen-dependent inactivation of catalase. 4-HNE and singlet oxygen cooperate in complex autoamplificatory loops during this process. The finding of these novel anticancer pathways may be useful for understanding the role of 4-HNE in the control of malignant cells and for the optimization of ROS-dependent therapeutic approaches including antioxidant treatments. © 2015 Elsevier Inc. All rights reserved.

Cappon H.,University of Applied science | Cappon H.,Center of Excellence for Sustainable Water Technology | Keesman K.J.,Wageningen University
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control | Year: 2012

Design of ultrasonic equipment is frequently facilitated with numerical models. These numerical models, however, need a calibration step, because usually not all characteristics of the materials used are known. Characterization of material properties combined with numerical simulations and experimental data can be used to acquire valid estimates of the material parameters. In our design application, a finite element (FE) model of an ultrasonic particle separator, driven by an ultrasonic transducer in thickness mode, is required. A limited set of material parameters for the piezoelectric transducer were obtained from the manufacturer, thus preserving prior physical knowledge to a large extent. The remaining unknown parameters were estimated from impedance analysis with a simple experimental setup combined with a numerical optimization routine using 2-D and 3-D FE models. Thus, a full set of physically interpretable material parameters was obtained for our specific purpose. The approach provides adequate accuracy of the estimates of the material parameters, near 1%. These parameter estimates will subsequently be applied in future design simulations, without the need to go through an entire series of characterization experiments. Finally, a sensitivity study showed that small variations of 1% in the main parameters caused changes near 1% in the eigenfrequency, but changes up to 7% in the admittance peak, thus influencing the efficiency of the system. Temperature will already cause these small variations in response; thus, a frequency control unit is required when actually manufacturing an efficient ultrasonic separation system. © 2012 IEEE.

Rubart J.,University of Applied science
NHT 2015 - Proceedings of the 2015 Workshop on Narrative and Hypertext - co-located with HT 2015 | Year: 2015

This paper introduces and presents application areas for face-to face collaboration points in storytelling for adults using multitouch tabletop solutions. The multitouch interaction appears natural and can nicely be used in a group. Furthermore, this paper describes experiences with face-to-face multitouch structures, i.e. how different structures have been used in collaboration. © 2015 ACM.

Kovacs T.,Hungarian Academy of Sciences | Kovacs T.,University of Applied science | Regaly Zs.,Hungarian Academy of Sciences
Astrophysical Journal Letters | Year: 2015

The circular restricted three-body problem is investigated in the context of accretion and scattering processes. In our model, a large number of identical non-interacting mass-less planetesimals are considered in the planar case orbiting a star-planet system. This description allows us to investigate the gravitational scattering and possible capture of the particles by the forming planetary embryo in a dynamical systems approach. Although the problem serves a large variety of complex motions, the results can be easily interpreted because of the low dimensionality of the phase space. We show that initial conditions define isolated regions of the disk, where planetesimals accrete or escape, which have, in fact, a fractal structure. The fractal geometry of these "basins" implies that the dynamics is very complex. Based on the calculated escape rates and escape times, it is also demonstrated that the planetary accretion rate is exponential for short times and follows a power law for longer integration. A new numerical calculation of the maximum mass that a planet can reach (described by the expression of the isolation mass) is also derived. © 2015. The American Astronomical Society. All rights reserved.

Cappon H.,University of Applied science | Keesman K.,Wageningen University
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control | Year: 2013

Our overall goal is to apply acoustic separation technology for the recovery of valuable particulate matter from wastewater in industry. Such large-scale separator systems require detailed design and evaluation to optimize the system performance at the earliest stage possible. Numerical models can facilitate and accelerate the design of this application; therefore, a finite element (FE) model of an ultrasonic particle separator is a prerequisite. In our application, the particle separator consists of a glass resonator chamber with a piezoelectric transducer attached to the glass by means of epoxy adhesive. Separation occurs most efficiently when the system is operated at its main eigenfrequency. The goal of the paper is to calibrate and validate a model of a demonstrator ultrasonic separator, preserving known physical parameters and estimating the remaining unknown or less-certain parameters to allow extrapolation of the model beyond the measured system. A two-step approach was applied to obtain a validated model of the separator. The first step involved the calibration of the piezoelectric transducer. The second step, the subject of this paper, involves the calibration and validation of the entire separator using nonlinear optimization techniques. The results show that the approach lead to a fully calibrated 2-D model of the empty separator, which was validated with experiments on a filled separator chamber. The large sensitivity of the separator to small variations indicated that such a system should either be made and operated within tight specifications to obtain the required performance or the operation of the system should be adaptable to cope with a slightly off-spec system, requiring a feedback controller. © 1986-2012 IEEE.

Rubart J.,University of Applied science
Proceedings - 2016 IEEE 10th International Conference on Semantic Computing, ICSC 2016 | Year: 2016

There is a strong need for customizing business information systems, such as ERP or CRM solutions. This paper focuses on emerging decisions and on business rules to support the decision making. The proposed business rules can be edited by end users as well as system components. Both-the users and the system-shall be able to learn business rules as well as integrate, and use them intelligently in the business information system. In order to address this concern, human-centered business rule engines are proposed, which integrate data mining support and provide intelligent user interfaces to collaborating users. An underlying ontology is used to specify the vocabulary for the business rules dependent on the business information system. We apply a mapping approach to map the concepts and relationships of the underlying ontology to user-oriented semantic types. Three usage scenarios give some examples of how the presented approach can be used. © 2016 IEEE.

Rubart J.,University of Applied science
CEUR Workshop Proceedings | Year: 2016

This paper presents a hybrid approach to annotations for face-toface settings. Firstly, multitouch-based cooperative interaction for large displays is used to support group discussions with many different structures. Secondly, augmented notes are used to integrate paper-based notes in electronic structures.

Kulcsar N.,University of Applied science
Hungarian Geographical Bulletin | Year: 2015

Considering the geographical and historical characteristics of Hungary, rural tourism could be one of the key tourism products since the country misses extraordinary natural attractions, seaside or high mountains. Hungary has always been an agricultural country and it is rich in cultural landscape with traditional small villages and rural hospitality. As in Hungary theoretical research on consumer value factors in rural tourism is completely missing the primary aim of our investigation was to conduct a niche survey in rural tourism, which can contribute to the better understanding of the demand side of the market and crystallise the factors with value to tourists. The aim of the pilot study based on qualitative research is to identify and measure consumer value dimensions. In our qualitative research first we completed indicators identified by secondary sources with further indicators, as the result of a small sample consumer survey, then we have refined the created list of indicators on the basis of expert opinions. As the next step of the research we have conducted a quantitative questionnaire-based survey, by which the aim was to identify, interpret and analyse the motivations of rural tourist and the indicator-based consumer value with its major dimensions. In this paper we discuss only the latter phase of our research in more detail. The basis of success of rural tourism in Hungary can be the identification of tourists’ motivations, attitudes, as well as factors that carry value for them, since it may reveal useful information both scientifically and practically. © 2015, Reasearch Centre for Astronomy and Earth Sciences Hungarian Academy. All rights reserved.

Kosec B.,University of El Salvador | Stoic M.,University of Applied science
Metalurgija | Year: 2014

This paper shows the impact of mixing water and abrasives in water jet cutting process on the quality of the machined surface. The tests were done with polymer material SIPAS, where the influence of cutting parameters was researched (cutting pressure, cutting feed and abrasive mass flow). The surface roughness was measured on several zones, regarding the depth of materials, because the roughness is increased with the material thickness.

Michels M.H.A.,Wageningen University | Michels M.H.A.,University of Applied science | Vaskoska M.,University of Applied science | Vermue M.H.,Wageningen University | Wijffels R.H.,Wageningen University
Water Research | Year: 2014

Wastewater from a fish farm was remediated in a continuously operated tubular photobioreactor in which Tetraselmis suecica was cultured. The N and P removal efficiencies and the productivity of T. suecica growing on the wastewater were determined. Possibilities to optimize the productivity by adding extra orthophosphate were investigated. At a biomass concentration of 0.5gL-1 on only wastewater, the N and P removal efficiencies were 49.4% and 99.0%, respectively. When extra phosphate was dosed to the wastewater, a 95.7% N removal efficiency and a 99.7% P removal efficiency could be reached at a biomass concentration of 1.0gL-1. This also resulted in significantly higher average net volumetric productivity ranging from 0.35gL-1d-1 at a biomass concentration of 0.5gL-1 to 0.46 and 0.52gL-1d-1 at biomass concentrations of 0.75 and 1.0gL-1, respectively.This study shows the feasibility of an integrated multi-trophic aquaculture approach where wastewater from the fish farms is used to produce feed for juvenile shellfish at high productivity and constant quality. © 2014 Elsevier Ltd.

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