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  • 251.
    Bräunig, Jennifer
    et al.
    Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Coopers Plains QLD, Australia.
    Baduel, Christine
    Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Coopers Plains QLD, Australia; University Lyon, CNRS, Université Claude Bernard Lyon 1, Ens de Lyon, Institut des Sciences Analytiques, Villeurbanne, France.
    Heffernan, Amy
    Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Coopers Plains QLD, Australia; The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville VIC, Australia.
    Rotander, Anna
    Örebro University, School of Science and Technology. Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Coopers Plains QLD, Australia.
    Donaldson, Eric
    Aviation Medical Specialist, Oakey Qld, Australia.
    Mueller, Jochen F.
    Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Coopers Plains QLD, Australia.
    Fate and redistribution of perfluoroalkyl acids through AFFF-impacted groundwater2017In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 596, 360-368 p.Article in journal (Refereed)
    Abstract [en]

    Leaching of perfluoroalkyl acids (PFAAs) from a local point source, a fire-fighting training area, has led to extensive contamination of a groundwater aquifer which has spread underneath part of a nearby town, Oakey, situated in the State of Queensland, Australia. Groundwater is extracted by residents from privately owned wells for daily activities such as watering livestock and garden beds. The concentration of 10 PFAAs in environmental and biological samples (water, soil, grass, chicken egg yolk, serum of horses, cattle and sheep), as well as human serum was investigated to determine the extent of contamination in the town and discuss fate and redistribution of PFAAs. Perfluorooctane sulfonate (PFOS) was the dominant PFAA in all matrices investigated, followed by perfluorohexane sulfonate (PFHxS). PFOS concentrations measured in water ranged between <0.17-14 mu g/L, concentrations of PFHxS measured between <0.07-6 mu g/L. PFAAs were detected in backyards (soil, grass), livestock and chicken egg yolk. Significant differences (p < 0.01) in PFOS and PFHxS concentrations in two groups of cattle were found, one held within the contamination plume, the other in the vicinity but outside of the contamination plume. In human serum PFOS concentrations ranged from 38 to 381 mu g/L, while PFHxS ranged from 39 to 214 mu g/L. Highest PFOS concentrations measured in human serum were >30-fold higher compared to the general Australian population. Through use of contaminated groundwater secondary sources of PFAA contamination are created on private property, leading to further redistribution of contamination and creation of additional human exposure pathways.

  • 252.
    Bräunig, Jennifer
    et al.
    Institute for Environmental Research, RWTH Aachen University, Aachen, Germany; National Research Centre for Environmental Toxicology (Entox), The University of Queensland, Brisbane, Australia.
    Schiwy, Sabrina
    Institute for Environmental Research, RWTH Aachen University, Aachen, Germany.
    Broedel, Oliver
    Molecular Biotechnology and Functional Genomics, Technical University of Applied Sciences Wildau, Wildau, Germany.
    Müller, Yvonne
    Institute for Environmental Research, RWTH Aachen University, Aachen, Germany.
    Frohme, Marcus
    Molecular Biotechnology and Functional Genomics, Technical University of Applied Sciences Wildau, Wildau, Germany.
    Hollert, Henner
    Institute for Environmental Research, RWTH Aachen University, Aachen, Germany.
    Keiter, Steffen
    Örebro University, School of Science and Technology. Institute for Environmental Research, RWTH Aachen University, Aachen, Germany.
    Time-dependent expression and activity of cytochrome P450 1s in early life-stages of the zebrafish (Danio rerio)2015In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 22, no 21, 16319-15328 p.Article in journal (Refereed)
    Abstract [en]

    Zebrafish embryos are being increasingly used as model organisms for the assessment of single substances and complex environmental samples for regulatory purposes.Thus, it is essential to fully understand the xenobiotic metabolism during the different life-stages of early development.The aim of the present study was to determine arylhydrocarbon receptor (AhR)-mediated activity during selected times of early development using qPCR, enzymatic activity through measurement of 7-ethoxyresorufin-Odeethylase(EROD) activity, and protein expression analysis. In the present study, gene expression of cyp1a, cyp1b1, cyp1c1, cyp1c2, and ahr2 as well as EROD activity were investigated up to 120 h postfertilization (hpf) after exposure to either β-naphthoflavone (BNF) or a polycyclic aromatichydrocarbons (PAH)-contaminated sediment extract from Vering Kanal in Hamburg (VK). Protein expression was measured at 72 hpf after exposure to 20 μg/L BNF. Altered proteins were identified by matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) peptide mass fingerprinting. Distinct patterns of basal messenger RNA (mRNA) expressionwere found for each of the cyp1 genes, suggesting specific roles during embryonic development. All transcripts were induced by BNF and VK. ahr2 mRNA expression was significantly upregulated after exposure toVK. All cyp1 genes investigated showed a temporal decline in expression at 72 hpf. The significant decline of Hsp 90β protein at 72 hpf after exposure to BNF may suggest an explanation for the decline of cyp1 genes at this time point as Hsp 90β is of major importance for the functioning of the Ah-receptor. EROD activity measured in embryos was significantly induced after 96 hpf of exposure to BNF or VK. Together, these results demonstrate distinct temporal patterns of cyp1 genes and protein activities in zebrafish embryos as well as show a need to investigate further the xenobiotic biotransformation system during early development of zebrafish.

  • 253.
    Bröner, Max
    Örebro University, School of Science and Technology.
    Rörelsedetektering och uppföljning i kamerasystem2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is about image processing in programming langue and what different areas it might get useful in and how it works in this program. 

    The program compares 2 pictures with each other and then look if they are the same or something have been altered if so it gives a notes to the user. 

    In this rapport I’m going true how I did do the program and what problems I encountered during the programming and how I solved it like how I used the program library and how I handled the entire data movement through the program.

  • 254.
    Buitrago, B. Huerta
    et al.
    Mälardalen University, Västerås, Sweden.
    Munoz, P. Ferrer
    Mälardalen University, Västerås, Sweden.
    Ribe, V.
    Mälardalen University, Västerås, Sweden.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Wojciechowska, E.
    Gdansk University of Technology, Gdansk, Poland.
    Waara, S.
    Mälardalen University, Västerås, Sweden.
    Hazard assessment of sediments from a wetland system for treatment of landfill leachate using bioassays2013In: Ecotoxicology and Environmental Safety, ISSN 0147-6513, E-ISSN 1090-2414, Vol. 97, 255-262 p.Article in journal (Refereed)
    Abstract [en]

    Four bioassays were used in this study for the hazard assessment of sediments from sediment traps and several ponds in a treatment wetland for landfill leachate at Atleverket, Sweden. In the 6-day solid phase microbiotest with the sediment-dwelling crustacean Heterocypris incongruens both acute and chronic effects were observed with a gradual decrease and loss of toxicity with treatment in the wetland system. Some samples showed a low toxicity in porewater and only one sample was weakly toxic in the whole sediment test when assessed with Aliivibrio fischeri (Vibro fischeri). No genotoxicity was detected in the umu test. The toxicity response in the H4IIE- luc test evaluating the presence of dioxin-like compounds was considerably higher in the samples from the sediment traps. The hazard of the sediment therefore appears to be highest in the sediment traps and pond 1 with the methods employed. The result indicates that the wetland system has a design supporting the concentration and sequestration of toxic substances in the first part of the wetland. Based upon the results we suggest that hazard assessment of sediments from other treatment wetlands for landfill leachate should be conducted. (c) 2013 Elsevier Inc. All rights reserved.

  • 255.
    Bunz, Elsa
    et al.
    Örebro University, Örebro, Sweden.
    Chadalavada, Ravi Teja
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Krug, Robert
    Örebro University, School of Science and Technology.
    Schindler, Maike
    Örebro University, School of Science and Technology.
    Lilienthal, Achim
    Örebro University, School of Science and Technology.
    Spatial Augmented Reality and Eye Tracking for Evaluating Human Robot Interaction2016In: Proceedings of RO-MAN 2016 Workshop: Workshop on Communicating Intentions in Human-Robot Interaction, 2016Conference paper (Refereed)
    Abstract [en]

    Freely moving autonomous mobile robots may leadto anxiety when operating in workspaces shared with humans.Previous works have given evidence that communicating in-tentions using Spatial Augmented Reality (SAR) in the sharedworkspace will make humans more comfortable in the vicinity ofrobots. In this work, we conducted experiments with the robotprojecting various patterns in order to convey its movementintentions during encounters with humans. In these experiments,the trajectories of both humans and robot were recorded witha laser scanner. Human test subjects were also equipped withan eye tracker. We analyzed the eye gaze patterns and thelaser scan tracking data in order to understand how the robot’sintention communication affects the human movement behavior.Furthermore, we used retrospective recall interviews to aid inidentifying the reasons that lead to behavior changes.

  • 256.
    Bäckström, Mattias
    Örebro University, School of Science and Technology.
    Environmental impact from an alum shale deposit, Kvarntorp, Sweden: Present and future scenarios2010In: Mine water & innovative thinking: proceedings 2010 / [ed] Wolkersdorfer, C. and Freund, A., Nova Scotia, Canada: Cape Breton University Press , 2010, 551-554 p.Conference paper (Refereed)
    Abstract [en]

    During the second World War it was decided to produce oil through pyrolysis of alum shalegiving rise to waste products (coke and ash). Waste was deposited in the open pits and in a waste deposit.Due to the high remaining energy in the waste materials the waste deposit still today has significantlyelevated temperatures (above 500 °c). remaining pyrite in the waste material has also led to ArDwith elevated trace metal concentrations. the waste deposit is no great environmental problemtoday but as soon as the waste pile cools off both the volumes of drainage and concentrations oftrace metals will increase dramatically

  • 257.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology.
    Domeij, Joel
    Sartz, Lotta
    Örebro University, School of Science and Technology. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Flooding of oxidized waste rock amended with alkaline by-products2010In: 34th British Columbia Mine Reclamation & 35th CLRA/ACRSD National Conference, 2010, 10 pages- p.Conference paper (Refereed)
    Abstract [en]

    Leaching of trace elements (Cd, Cu, Pb and Zn) from oxidized waste rock amended with different alkaline by-products was studied during flooding. It has been argued that water covers for oxidized waste would significantly increase leaching through reductive dissolution of the pre-formed hydrous ferric oxides and the associated trace elements. After approximately three weeks pH in the reference had reached 2.5 and 3.3 in the pore and overlying water, respectively. This can be compared with pH from 6.1 (water works granules) to above 10 (lime kiln dust) in the amended systems. It is clear that the carbonate dominated alkaline by-products have lower pH than the oxide/hydroxide based by-products. However, the systems amended with carbonate based by-products have significantly higher alkalinity. Cadmium, Cu, Pb and Zn concentrations within the waste decreased with at least 99% compared to the reference. In most systems the surface waters can even be used as drinking water. Cadmium, copper and zinc concentrations are clearly related to pH with decreasing concentrations with increasing pH. Lead concentrations, on the other hand, decrease to pH 8, where the concentrations start to increase slightly again due to the formation of soluble Pb(OH)₃⁻ and Pb(OH)₄²⁻ species. The results indicate that flooding of oxidized waste rock amended with alkaline by-products can be used as a successful remediation technique.

  • 258.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology.
    Häller, Sara
    Örebro University, School of Science and Technology.
    Allard, Bert
    Örebro University, School of Science and Technology.
    Geochemical processes in a historical alum shale dump, Kvarntorp2011In: Programme and Abstracts / [ed] Sarala P, Ojala VJ, Porsanger M-L, Vuorimiesyhdistys , 2011, 97, 6p CD-Rom- p.Conference paper (Refereed)
  • 259.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Ekholm, David
    Evenhamre, Per
    Skogsjö, Erika
    Sediment quality before, during and after remediation of historical mine waste at Bersbo, Sweden2009In: Securing the Future and 8th ICARD, 2009, 11 pages- p.Conference paper (Refereed)
  • 260.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology. Bergskraft Bergslagen AB, Kopparberg.
    Sartz, Lotta
    Örebro University, School of Science and Technology. Bergskraft Bergslagen AB, Kopparberg.
    Fly ash injection into weathered mine waste2013In: Annual International Mine Water Association Conference: Reliable Mine Water Technology / [ed] Brown, A.; Figueroa, L. & Wolkersdorfer, Ch., Colorado, USA: IMWA , 2013, 513-519 p.Conference paper (Refereed)
    Abstract [en]

    By adding alkaline ashes through injection to weathered mine waste pH increased approximately 3 units, trace element was immobilized and flow rate decreased due to formation of hard pans. Reduction in trace element concentrations was around 96.9-99.6 % for copper, 94.7-99.7 % for zinc and 22.9-99.8 % for cadmium. For lead the best reduction was 97.3 % and the worst -393 % (increase). MSWI ashes performed worst with low buffering capacity and increase in vanadium and molybdenum concentrations.

  • 261.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology.
    Sartz, Lotta
    Bergskraft, Bergslagen AB, Kopparberg.
    Permanent under water storing of weathered mine waste after removal of fine fraction and addition of ash2014In: An Interdisciplinary Response to Mine Water Challenges / [ed] Sui, W., Sun, Y. & Wang, C., Xuzhou: China University of Mining and Technology Press , 2014, 711-714 p.Conference paper (Refereed)
    Abstract [en]

    Weathered sulphidic mine waste is a major environmental problem. An experiment was performed in order to study water covers for oxidized mine waste. In two experiments oxidized mine waste were covered with water, in one experiment the fine fraction was removed and in one experiment alkaline ash was also added prior to water covering. It was found that removal of the fine fraction decreased pH and increased trace element concentrations. Water covering of the mine waste with and without ash decreased trace element concentrations indicating that co disposing oxidized sulphidic mine waste and ash under water might be a promising remediation method.

  • 262.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology.
    Sartz, Lotta
    Örebro University, School of Science and Technology. Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Stabilization of acid generating waste rock with fly ash: Immobilization of arsenic under alkaline conditions2010In: Mine water & innovative thinking: proceedings 2010 / [ed] Wolkersdorfer, C. and Freund, A., ovaScotia, Canada: Cape Breton University Press , 2010, 555-558 p.Conference paper (Refereed)
    Abstract [en]

    A fly ash was used to increase pH and decrease arsenic leaching from an acidic mine waste.Both the amended system as well as the control system was leached with ultra pure water. pH in thecontrol increased from 1.7 to 2.7 at the end of the experiment while the pH in the amended systemdecreased from 12.6 to 11.5. compared to the control the initial concentrations of arsenic decreasedwith almost three orders of magnitude in the amended systems. A combination of co precipita-tion with iron and calcium arsenate precipitation were identified as the major arsenic immobi-lization mechanisms.

  • 263.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology.
    Sartz, Lotta
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Uranium leaching from a burning black shale deposit: Present conditions and future scenarios2015In: Uranium – Past and Future Challenges: Proceedings of the 7th International Conference on Uranium Mining and Hydrogeology / [ed] Broder, J; Arab, Alireza, Springer Publishing Company, 2015, 47-54 p.Conference paper (Refereed)
    Abstract [en]

    During WW2 oil was produced through pyrolysis of alum shale giving rise to waste that was deposited in the open pits and in a waste deposit. The waste deposit still today has significantly elevated temperatures (above 500 °C). Remaining pyrite in the waste material has also led to ARD with elevated trace metal concentrations. The waste deposit is no great environmental problem today but as soon as the waste pile cools off both the volumes of drainage and concentration of uranium will increase significantly.

  • 264.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology.
    Sartz, Lotta
    Örebro University, School of Science and Technology. Bergskraft Bergslagen AB, Kumla, Sweden.
    Use of multivariate statistics in order to understand the flow of acid rock drainage from an abandoned mining site2016In: Journal of Environmental Protection, ISSN 2152-2197, E-ISSN 2152-2219, Vol. 7, no 3, 358-371 p.Article in journal (Refereed)
    Abstract [en]

    Pathways for acid rock drainage from an abandoned mining site (sulphidic ore) were investigated by analysing ground, seepage and surface waters. It was found that in affected ground and seepage waters pH was lower (average pH 5.0); sulphate higher (average 350 mg/L) and trace element concentrations were significantly increased (4330 μg/L copper and 7700 μg/L zinc) compared to surrounding waters. Multivariate statistics (principal component analysis) were used on the data set. Obtained loading plot showed a clear negative correlation between pH and parameters found at high concentrations, indicating that these parameters are found at the source term (acid rock drainage). Lead was also found in close proximity to iron and turbidity indicating that lead might be associated with particles. The score plot presented almost all samples from high concentrations to low concentrations along the first principal component (explaining 63% of the variation in the data set) indicating that dilution was an important mechanism for the decrease in concentrations as opposed to immobilisation on surfaces along the flowpath. Decrease in fluoride and sulphate along one of the suspected flowpath coincided with an increase in calcium. Through geochemical calculations it was concluded that calcite (CaCO3) dissolved along the flowpath and thus induced precipitation of gypsum (CaSO4) and fluorite (CaF2). Through a combination of PCA and geochemical calculations the most likely flowpaths for contaminated water from the abandoned mining site were presented, making it possible to prevent further negative effects on the surface water.

  • 265.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology.
    Sartz, Lotta
    Örebro University, School of Science and Technology.
    Larsson, Erik
    Bergskraft Bergslagen, Kopparberg, Sweden.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Properties of alkaline materials for injection into weathered mine waste piles: methods and initial pilot trials2011In: Mine water: managing the challenges: proceedings of the International Mine Water Association Congress 2011 / [ed] Rüde, Thomas R.; Freund, Antje; Wolkersdorfer, Christian, Aachen: RWTH , 2011, 265-269 p.Conference paper (Refereed)
    Abstract [en]

    Several alkaline materials were studied with regards to their ability to form stable suspensions withwater. Gravitational injection of alkaline materials were performed into weathered mine waste in two differentpilot scales (25 L and 1 000 L). When water was added after injection lime mud (LM) was flushed out whilelime kiln dust (LKD) and green liqour (GLD) remained within the mine waste. Deconstruction of the pilot sys-tems showed that both materials had penetrated the voids present. LKD and GLD increased pH significantlyand reduced trace metal concentratios. It is concluded that both LKD and GLD are suitable for stabilizing acidgenerating mine waste.

  • 266.
    Bäckström, Mattias
    et al.
    Örebro University, School of Science and Technology.
    Sädbom, Stefan
    Bergskraft Bergslagen AB, Kopparberg, Sweden.
    Suggestion for a protocol for detailed investigation of historical mine sites2012In: 9th International Conference on Acid Rock Drainage (ICARD 2012) / [ed] Price, W.A., Hogan, C. and Tremblay, G., Red Hook, NY: Curran Associates, Inc., 2012, 1340-1350 p.Conference paper (Refereed)
    Abstract [en]

    A protocol for detailed investigation of mine sites is suggested. Results from the investigation are important when planning mine site reclamation. Initially, the mine site is divided into several sub sites according to topography. For general appearance the following parameters were developed and estimated directly in the field for every sub site:

    (1) shape, (2) historical land use, (3) amount of waste rock, (4) weathering, (5) waste rock size, (6) carbonates and silicates, (7) vegetation cover, (8) low and high species, (9) moss and grass/herbs, (10) broad-leaf and coniferous, (11) spruce and pine, (12) birch and aspen, and (13) blueberries and lingonberries. Every parameter was designated a numerical value between 0 and 5. After sampling ocular mineral/rock classification was performed on composite samples from every sub site and the following major components were determined: (14) silicate, (15) mica, (16) granite/pegmatite, (17) carbonates, (18) iron oxide ore and (19) sulphide ore. In addition the relative distribution between the different sulphide minerals was also determined: (20) chalcopyrite vs sphalerite; (21) galena vs sphalerite; (22) chalcopyrite vs galena and (23) pyrite vs pyrrhotite.

    Results from a historical mine site in Kopparberg, Sweden, are used to illustrate the methodology

  • 267.
    Bädicker, Rickard
    et al.
    Örebro University, School of Science and Technology.
    Ekman, Marcus
    Örebro University, School of Science and Technology.
    Standard och reducering av ställtider2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Ovako is a global steel producer that delivers products in Europe, USA and Asia. Their turnover during the last year was 781 million Euro. The steel industry has under the recent years overproduced steel which has contributed high competition in the steel market. Based on this, an optimization project has been established to maintain the global competitiveness, [1,4].

    This study aims at streamlining a fine grinding line, where two centerless grinding machines are used, to reduce the changeover time by 13,5min in case of major changes. The project will also create new standards for how the work of conversion should be carried out for this efficiency. The study is carried out at Ovako´s production facility in Hällefors, Sweden.

    The problem in the workplace is that the uncertainty of staff in the event of changeover contributes to varied changeover times. This uncertainty has also contributed to the fact that the learning time for changeover in approximately 1 year.

    The project starts with an analysis in which mobile recording is used to get an overview of the problem. Methods like SMED, Lean, Tree diagram, SPS and production planning are then used. This investigation resulted in time studies, new tree diagram, design of a toolbar, reconstruction of supporting wheel, reconstruction of gap settings, result charts/control charts and a leveling simulation. This resulted finally in a new standard and suggestions for machine optimization.

    The final efficiency improvement corresponds to 16.5min, if 8680 SEK is invested. The study also mentions extra investments for even greater efficiency.

    Within the study there are some assumed values as the facts for certain parts cannot be obtained. These assumptions are not something that has been incorporated into the final streamlining, which means that the study can be considered credible.

  • 268.
    Börjesson, Patrik
    et al.
    Örebro University, School of Science and Technology.
    Åkerling, Filip
    Örebro University, School of Science and Technology.
    Lastsimulering för testbuss2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis project aims to find a new solution for simulation of passengers and cargo in a

    bus during field-testing. The project has been carried out in cooperation with Laxå Special

    Vehicles in Laxå Sweden who are going to build a new testbus for Scania. Scania have an

    older testbus that is going to be replaced and a new system for simulation of cargo and

    passengers is going to be developed.

    This project has used the method of systematic design described by Johannesson,

    Persson and Petterson (2004). This method can be divided in five parts, product

    specification, concept generation, concept evaluation and selection, detail design and final

    design.

    The system used today has several disadvantages, among others that it’s difficult and

    time consuming to change the load configuration. There is also problem with freezing

    during winter since the old system uses water as weight medium.

    One of the concepts developed where chosen to be further designed into a final design.

    The chosen concept is totally new and doesn’t use any parts from the old system. This

    system uses two different fixtures, one that will place the weight in the right height and

    one that will be the weight. These fixtures can be placed on each other to obtain the

    wanted load situation.

  • 269.
    Cakmak, Miray
    Örebro University, School of Science and Technology.
    Användning av den interaktiva skrivtavlan i matematikundervisning: Fördelar respektive utmaningar med den interaktiva skrivtavlan2017Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The interactive writing board is a lesson instrument that is available today, in the most Swedish schools. The purpose of the study is to examine how teachers describe its use of interactive writing boards in teaching mathematics and how often they use it. In order to answer my questions, I have done a qualitative study, where I interviewed five teachers who work in grades 1-3 and are using the interactive writing board, but also examined what the literature says. To find out what kind of knowledge the teachers express, I have compared my result of analysis against Shulmans (1986) theory about TPACK - Technical, Pedagogical and Content Knowledge. TPACK has three different areas consisting of technical knowledge, pedagogical knowledge and content knowledge. It's only when these three knowledges interact with each other, that you get a good teaching. These knowledges are important knowledge that teachers need to use interactive writing boards in mathematics teaching, but also to promote students' learning and commitment.

  • 270.
    Canelhas, Daniel R.
    et al.
    Örebro University, School of Science and Technology.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    From Feature Detection in Truncated Signed Distance Fields to Sparse Stable Scene Graphs2016In: IEEE Robotics and Automation Letters, ISSN 2377-3766, Vol. 1, no 2, 1148-1155 p.Article in journal (Refereed)
    Abstract [en]

    With the increased availability of GPUs and multicore CPUs, volumetric map representations are an increasingly viable option for robotic applications. A particularly important representation is the truncated signed distance field (TSDF) that is at the core of recent advances in dense 3D mapping. However, there is relatively little literature exploring the characteristics of 3D feature detection in volumetric representations. In this paper we evaluate the performance of features extracted directly from a 3D TSDF representation. We compare the repeatability of Integral invariant features, specifically designed for volumetric images, to the 3D extensions of Harris and Shi & Tomasi corners. We also study the impact of different methods for obtaining gradients for their computation. We motivate our study with an example application for building sparse stable scene graphs, and present an efficient GPU-parallel algorithm to obtain the graphs, made possible by the combination of TSDF and 3D feature points. Our findings show that while the 3D extensions of 2D corner-detection perform as expected, integral invariants have shortcomings when applied to discrete TSDFs. We conclude with a discussion of the cause for these points of failure that sheds light on possible mitigation strategies.

  • 271.
    Canelhas, Daniel R.
    et al.
    Örebro University, School of Science and Technology.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Improved local shape feature stability through dense model tracking2013In: Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, 2013, 3203-3209 p.Conference paper (Refereed)
    Abstract [en]

    In this work we propose a method to effectively remove noise from depth images obtained with a commodity structured light sensor. The proposed approach fuses data into a consistent frame of reference over time, thus utilizing prior depth measurements and viewpoint information in the noise removal process. The effectiveness of the approach is compared to two state of the art, single-frame denoising methods in the context of feature descriptor matching and keypoint detection stability. To make more general statements about the effect of noise removal in these applications, we extend a method for evaluating local image gradient feature descriptors to the domain of 3D shape descriptors. We perform a comparative study of three classes of such descriptors: Normal Aligned Radial Features, Fast Point Feature Histograms and Depth Kernel Descriptors; and evaluate their performance on a real-world industrial application data set. We demonstrate that noise removal enabled by the dense map representation results in major improvements in matching across all classes of descriptors as well as having a substantial positive impact on keypoint detection reliability

  • 272.
    Canelhas, Daniel R.
    et al.
    Örebro University, School of Science and Technology.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    SDF tracker: a parallel algorithm for on-line pose estimation and scene reconstruction from depth images2013In: Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, 2013, 3671-3676 p.Conference paper (Refereed)
    Abstract [en]

    Ego-motion estimation and environment mapping are two recurring problems in the field of robotics. In this work we propose a simple on-line method for tracking the pose of a depth camera in six degrees of freedom and simultaneously maintaining an updated 3D map, represented as a truncated signed distance function. The distance function representation implicitly encodes surfaces in 3D-space and is used directly to define a cost function for accurate registration of new data. The proposed algorithm is highly parallel and achieves good accuracy compared to state of the art methods. It is suitable for reconstructing single household items, workspace environments and small rooms at near real-time rates, making it practical for use on modern CPU hardware

  • 273.
    Canelhas, Daniel Ricão
    Örebro University, School of Science and Technology.
    Truncated Signed Distance Fields Applied To Robotics2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis is concerned with topics related to dense mapping of large scale three-dimensional spaces. In particular, the motivating scenario of this work is one in which a mobile robot with limited computational resources explores an unknown environment using a depth-camera. To this end, low-level topics such as sensor noise, map representation, interpolation, bit-rates, compression are investigated, and their impacts on more complex tasks, such as feature detection and description, camera-tracking, and mapping are evaluated thoroughly. A central idea of this thesis is the use of truncated signed distance fields (TSDF) as a map representation and a comprehensive yet accessible treatise on this subject is the first major contribution of this dissertation. The TSDF is a voxel-based representation of 3D space that enables dense mapping with high surface quality and robustness to sensor noise, making it a good candidate for use in grasping, manipulation and collision avoidance scenarios.

    The second main contribution of this thesis deals with the way in which information can be efficiently encoded in TSDF maps. The redundant way in which voxels represent continuous surfaces and empty space is one of the main impediments to applying TSDF representations to large-scale mapping. This thesis proposes two algorithms for enabling large-scale 3D tracking and mapping: a fast on-the-fly compression method based on unsupervised learning, and a parallel algorithm for lifting a sparse scene-graph representation from the dense 3D map.

    The third major contribution of this work consists of thorough evaluations of the impacts of low-level choices on higher-level tasks. Examples of these are the relationships between gradient estimation methods and feature detector repeatability, voxel bit-rate, interpolation strategy and compression ratio on camera tracking performance. Each evaluation thus leads to a better understanding of the trade-offs involved, which translate to direct recommendations for future applications, depending on their particular resource constraints.

  • 274.
    Carlberg, Michael
    et al.
    Univ Orebro, Dept Oncol, Fac Med & Hlth, SE-70182 Orebro, Sweden..
    Hardell, Lennart
    Örebro University, School of Science and Technology. Dept Oncol.
    Pooled analysis of Swedish case-control studies during 1997-2003 and 2007-2009 on meningioma risk associated with the use of mobile and cordless phones2015In: Oncology Reports, ISSN 1021-335X, E-ISSN 1791-2431, Vol. 33, no 6, 3093-3098 p.Article in journal (Refereed)
    Abstract [en]

    A pooled analysis of two case-control studies on meningioma with patients diagnosed during 1997-2003 and 2007-2009 was conducted. Both genders were included, aged 20-80 and 18-75 years, respectively, at the time of diagnosis. Population-based controls, matched according to age and gender, were enrolled. Exposure was assessed by questionnaire. In the entire study, cases with all brain tumor types were included. The whole reference group was used in the unconditional logistic regression analysis on meningioma, with adjustments for gender, age, year of diagnosis and socioeconomic index (SEI). In total, 1,625 meningioma cases and 3,530 controls were analyzed. Overall no association with use of mobile or cordless phones was found. In the fourth quartile of use (>1,436 h) somewhat increased risk was found for mobile phones yielding an odds ratio (OR)=1.2, 95% confidence intervals (CI)=0.9-1.6 and cordless phones OR=1.7, 95% CI=1.3-2.2. Higher risk was calculated in the highest decile (>3,358 h), OR=1.5, 95% CI=0.99-2.1 and OR=2.0, 95% CI=1.4-2.8, respectively. In addition, the longest latency time gave somewhat increased risk for both phone types although the result was not statistically significant. There was no association for ipsilateral use or anatomical tumor location. The present study showed a somewhat increased risk among heavy users of mobile and cordless phones. Since meningioma is generally a slow-growing tumor, longer latency period is necessary for definitive conclusions.

  • 275.
    Carling, Johan
    et al.
    Örebro University, School of Science and Technology.
    Morenga, Magnus
    Örebro University, School of Science and Technology.
    Vibrationsanalys i en solidfräs2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Volvo Powertrain in Köping manufactures bevel gears used in the process of gear kits used in marine transmissions from Volvo Penta. In order to manufacture these gears a solid cutter is used. The wear on the cuttingtool increases with the number of details that are produced. As the cutter becomes more worn, it is harder to cut the material and the vibration increases.

    After a predetermined number of parts is processed the cutting edges is sharpened. However, this predetermined number is only an estimated number of how much the cutter can handle. The aim was to investigate if the cutter was able to process more details than they are doing today, before a sharpening of the cutting edges is necessary.

    Using an accelerometer, a vibration analysis has been performed. By comparing vibration data with the measurement deviation, a limit was set when the part's dimensions were no longer approved.

    In report we present two different strategies that can be used to determine when the cutter has to be replaced. However, in order to ensure that the strategy is working more testing is needed.

  • 276.
    Carlsson, Johannes
    et al.
    Örebro University, School of Science and Technology.
    Hägglund, Jonatan
    Örebro University, School of Science and Technology.
    Att utöka noggrannheten i mätsystemet HiMacs2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The industry is now entirely dependent on computer systems in various parts of the

    organization. As systems become more powerful the opportunities for increased control and

    precision grows. The more defects and faults that can be detected before delivery, more

    customer satisfaction is obtained which leads to fewer unnecessary costs connected to, for

    example, recalls. Of course, this is desirable from the industry and leads to higher demands

    for information systems.

     

    This report discusses the opportunities to increase the measuring frequency of an existing

    industrial realtime system running on a PC with Windows as operating system that is

    designed for test runs and measurements of engines and transmissions. Limitations that

    comes with using a nonreal time operating system in a real time industrial application is

    cleared up. The option for real time communication that HiMacs uses, developed by

    Beckhoff Automation, is also described.

     

    The project was investigative and various proposed solutions were developed and compared

    to each other to achieve the most reliable solution.

  • 277.
    Carlsson, Sofia
    Örebro University, School of Science and Technology.
    Vad påverkar elevers attityder till matematik?: En systematisk litteraturstudie med fokus på hur positiva attityder kan främjas.2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In society today, mathematics appears to be a boring and difficult subject that only some people can manage. Many students have negative attitudes towards the subject, which means that their interest in what is thought in the math lessons decreases and they are missing out on opportunities to learn. To promote pupils' learning in mathematics and to prevent students from taking their negative attitudes into adulthood, the present study aims to investigate what effects various kinds of influences may have on students’ attitudes towards mathematics and, above all, how they can be positively influenced. For the survey, a systematic literature study has been used and the basis for the compiled research overview has been retrieved from the Web of Science database. The results of the study indicate that there are several types of influences on pupils’ attitudes towards mathematics and that the influence both can have a positive and a negative effect depending on how it is handled and expressed. However, the most important types of influences can be summarized into social factors, the students' perspective on the subject and on who they think can manage it and the student´s believes of mathematics and the teaching as a meaningful subject.

  • 278.
    Carlsson, Ulrika
    et al.
    Örebro University, School of Science and Technology.
    Collstam, Viktoria
    Örebro University, School of Science and Technology.
    Visualisering av respektive stations takttid på en specifik monteringsbana på GKN Driveline i Köping AB2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The thesis was performed on the department of assembling at GKN Driveline AB in Koping, where final- and bevel gear is assembled and then provided to global customers in the car industry.

    The total rate for the assembly line which this project included is 64 seconds, but in the current situation the total rate is often higher. The problem is that it’s not possible to see if the assembler tact right or not on each assembly station, resulting in that it’s not possible to identify where on the line the time loss occurs and where the root cause lies in a rate that’s too high, when there’s no indicator on that.

    The aim of this project was to produce a solution that makes it possible for the assembler to see the rate on each station. Advantages and disadvantages with a visualization was analyzed, evaluated and presented, and an overall cost estimate was also produced. The written report works as a foundation for a possible future implementation.

    The basis of the thesis were literature studies in the areas of Lean production and stress, external benchmarking to collect information and inspiration, and also interviews with the employees at GKN Driveline to highlight the views and thoughts on a possible effect of a visualization on humans. In addition to the collecting of the different information above a proprietary method for the production of the final solution was implemented.

    The final solution that was produced was an enhancement to the company’s already existing industrial system. The product visualizes the rate for the assembler and records and stores data which entails several advantages. A discussion about how the visualization will be as efficient as possible together with final recommendations have been presented and if the implementation is carried out and improves the production result the visualization can be usefully applied to all the company’s assembly lines.

  • 279.
    Carlsvärd, Carl
    et al.
    Örebro University, School of Science and Technology.
    Walan, Rasmus
    Örebro University, School of Science and Technology.
    Produktionsplanering2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The flow of information within companies is something that occurs in all kinds of industries. It can be flow of information within everything from healthcare to. It is important that those involved in the company understand the importance of the information and what the consequences may be if the information is not conveyed properly.

    Meritor HVS AB, with its factory in Lindesberg, has for a long time had problems with the reports of parts in the business system, Oracle. To do the reports of the parts, the system uses a number witch is placed on the various pallets in witch the parts are placed in, in the production. These needs to be reported into the business system for other departments to know how many parts there are in production or that have been produced. The report is the basis for, for example, future purchases of material, what the financial cost of each item will be, as well as the purpose of tracking errors in final produced part when it´s been delivered to the customer. If this reporting is not done correctly, misleading numbers will occure in the business system. This leads to that large amounts of money goes to the purchase of materials that the company is not in need of. Therefore, this reporting must be done correctly.

    The reporting errors occures due to various causes that appear in the manufacturing process. These factors will be identified in this study by mapping the company's manufacturing process, a problem identification and the development of possible solution concepts. To perform a mapping of the manufacturing process, a zero-state analysis will be performed using interviews and observations. The problem identification will be based on the mapping and a root cause analysis will be done using various tools such as ishikawadiagram (fishbone diagrams) and 5 why. Solution concepts will be based on the identified issues.

    The solution to reporting errors can be technical solutions that simplify the work with the reporting, or make it almost impossible for report errors to occur, a so called poka yoke solution. Another potential solution may be the implementation of standards. Standards means methodological standards that show operators how to execute their work in the best possible way. This gives the operator clear instructions so the errors do not occur. A technical solution is that the operators use scanners and a scale. Instead of manually performing the reports by typing them into the computer, the number on the pallets are scanned. This eliminates the risk of operators being able to write the number into the computer incorrectly. The scale is included in the concept to help out with the count of the amount of parts. The purpose with the scale is to convert the total weight of the parts to the number of parts. In this way, the operator can view a display exactly how many items there are in the pallet. This simplifies the calculation of the amount of part for the operator. To get more information about the technical solution concept, the company is advised to contact the scale seller. The conclusion in the report indicates that it is possible to implement such a solution.

    The procedure for how the project has been executed, followed by how its solutions have been developed and what types of solutions identified will be presented in this report.

  • 280. Carpin, Stefano
    et al.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Nevatia, Yashodhan
    Lewis, M.
    Wang, J.
    Quantitative Assessments of USARSim Accuracy2006Conference paper (Refereed)
  • 281.
    Carstensen, Isabelle
    et al.
    Örebro University, School of Science and Technology.
    Oderstad, Johanna
    Örebro University, School of Science and Technology.
    Produktutveckling av armbandsur till nytt marknadssegment2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes a product development project for TRIWA AB. The process aimed at developing a wristwatch within a new market segment with a lower price than the company currently offers. The problem was to create a product compatible with the brand's identity, yet distinguished from current products so that it did not compete with the watches in a higher price range. Several different theoretical areas were incorporated in this project such as; design methodology, industrial design, product development, materials engineering, manufacturing technology and environmental science.

    This problem was dealt with based on a methodology designed to suit this type of project. The method is described theoretically step by step before it is applied during development of a new wristwatch. The approach consists of five phases; planning, pilot study, concept development, evaluation and processing.

    The result consists of material produced when the method has been implemented in practice and a concept in line with the company requirements. It is a methodology that is generalizable on other design projects and a concept that meets the demands of the price, quality and design. The final concept is still in need of further processing such as prototyping by manufacturer and additional adjustments.

  • 282.
    Carvalho, Raquel N.
    et al.
    European Commission-DG Joint Research Centre, Institute for Environment and Sustainability, Italy.
    Arukwe, Augustine
    Norwegian University of Science & Technology, Trondheim, Norway.
    Ait-Aissa, Selim
    National Institute for Industrial Environment and Risks, Verneuil en Halatte, France.
    Bado-Nilles, Anne
    National Institute for Industrial Environment and Risks, Verneuil en Halatte, France Reims University, France.
    Balzamo, Stefania
    Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Rome, Italy.
    Baun, Anders
    Department of Environmental Engineering,Technical University of Denmark, Kgs Lyngby, Denmark.
    Belkin, Shimshon
    Institute of Life Sciences, The Hebrew University of Jerusalem, Israel.
    Blaha, Ludek
    Faculty of Science, Masaryk University, RECETOX, Brno, Czech Republic.
    Brion, Francois
    National Institute for Industrial Environment and Risks, Verneuil en Halatte, France.
    Conti, Daniela
    Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Rome, Italy.
    Creusot, Nicolas
    National Institute for Industrial Environment and Risks, Verneuil en Halatte, France.
    Essig, Yona
    Analytical and Environmental Sciences Division, King's College London, UK.
    Ferrero, Valentina E. V.
    European Commission-DG Joint Research Centre, Institute for Environment and Sustainability, Italy.
    Flander-Putrle, Vesna
    Marine Biology Station Piran, National Institute of Biology, Slovenia.
    Furhacker, Maria
    University of Natural Resources and Life Sciences, Vienna, Austria.
    Grillari-Voglauer, Regina
    University of Natural Resources and Life Sciences, Vienna, Austria.
    Hogstrand, Christer
    Diabetes and Nutritional Sciences Division, King's College London, UK.
    Jonas, Adam
    Faculty of Science, Masaryk University, RECETOX, Brno, Czech Republic.
    Kharlyngdoh, Joubert B.
    Örebro University, School of Science and Technology.
    Loos, Robert
    European Commission-DG Joint Research Centre, Institute for Environment and Sustainability, Italy.
    Lundebye, Anne-Katrine
    National Institute of Nutrition and Seafood Research, Bergen, Norway.
    Modig, Carina
    Örebro University, School of Science and Technology. Life Science Center, Örebro University, Sweden.
    Olsson, Per-Erik
    Örebro University, School of Science and Technology. Life Science Center, Örebro University, Sweden.
    Pillai, Smitha
    University of Natural Resources and Life Sciences, Vienna, Austria.
    Polak, Natasa
    Analytical and Environmental Sciences Division, King's College London, UK.
    Potalivo, Monica
    Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Rome, Italy.
    Sanchez, Wilfried
    National Institute for Industrial Environment and Risks, Verneuil en Halatte, France.
    Schifferli, Andrea
    Swiss Centre for Applied Ecotoxicology, Eawag-EPFL, Dübendorf, Switzerland.
    Schirmer, Kristin
    Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; ETH Zürich, Department of Environmental Systems Science, Swiss Federal Institute of Technology, Zürich, Switzerland; EPF Lausanne, School of Architecture, Civil and Environmental Engineering, Lausanne, Switzerland.
    Sforzini, Susanna
    Department of Environmental and Life Sciences, Università del Piemonte Orientale Vercelli Novara Alessandria, Alessandria, Italy.
    Sturzenbaum, Stephen R.
    Analytical and Environmental Sciences Division, King's College London, UK.
    Søfteland, Liv
    National Institute of Nutrition and Seafood Research, Bergen, Norway.
    Turk, Valentina
    Marine Biology Station Piran, National Institute of Biology, Slovenia.
    Viarengo, Aldo
    Department of Environmental and Life Sciences, Università del Piemonte Orientale Vercelli Novara Alessandria, Alessandria, Italy.
    Werner, Inge
    Swiss Centre for Applied Ecotoxicology, Eawag-EPFL, Dübendorf, Switzerland.
    Yagur-Kroll, Sharon
    Institute of Life Sciences, The Hebrew University of Jerusalem, Israel.
    Zounkova, Radka
    Faculty of Science, Masaryk University, RECETOX, Brno, Czech Republic.
    Lettieri, Teresa
    European Commission-DG Joint Research Centre, Institute for Environment and Sustainability, Italy.
    Mixtures of chemical pollutants at European legislation safety concentrations: how safe are they?2014In: Toxicological Sciences, ISSN 1096-6080, E-ISSN 1096-0929, Vol. 141, no 1, 218-233 p.Article in journal (Refereed)
    Abstract [en]

    The risk posed by complex chemical mixtures in the environment to wildlife and humans is increasingly debated, but has been rarely tested under environmentally relevant scenarios. To address this issue, two mixtures of 14 or 19 substances of concern (pesticides, pharmaceuticals, heavy metals, polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic levels. A consortium of 16 laboratories was involved in performing the bioassays. The mixtures elicited quantifiable toxic effects on some of the test systems employed, including i) changes in marine microbial composition, ii) microalgae toxicity, iii) immobilization in the crustacean Daphnia magna, iv) fish embryo toxicity, v) impaired frog embryo development, and vi) increased expression on oxidative stress-linked reporter genes. Estrogenic activity close to regulatory safety limit concentrations was uncovered by receptor-binding assays. The results highlight the need of precautionary actions on the assessment of chemical mixtures even in cases where individual toxicants are present at seemingly harmless concentrations.

  • 283.
    Caspillo, Nasim Reyhanian
    Örebro University, School of Science and Technology.
    Hitting the mark: studies of alterations in behaviour and fertility in ethinyl estradiol-exposed zebrafish and search related biomarkers2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, we have analysed the effects of EE2 on non-reproductive behaviours and fertility. We have showed that two doses of EE2 in male adult short-term exposures evokes opposite behaviours in the novel tank test. A lower dose induced increased bottom-dwelling, a sign of increased anxiety and a higher dose increased surface-dwelling, which would likely expose themselves to predation in a natural environment. Increased shoaling was observed in both exposures, possibly affecting feeding and reproduction opportunities. Fertility analysis of these fish demonstrated a complete inhibition of spawning in the highest dose group. To investigate mechanisms behind the spawning failure, we examined expression levels of genes involved in zebrafish sex differentiation and maintenance of gonadal function. We found downregulated transcription levels of male-predominant genes, suggesting a demasculinization of the testes contributing to functional sterility in these fish. We have demonstrated that non-reproductive behaviour in zebrafish is highly sensitive to EE2 exposure during development. After exposing male and female zebrafish to low doses of EE2 followed by remediation in clean water until adulthood, the fish displayed increased anxiety and shoaling behaviour, demonstrating persistent effects of EE2. Furthermore, behavioural effects were transferred to their progeny. Decreased fertilisation success of the developmentally exposed fish was observed in both sexes when mated to untreated animals of the opposite sex. These fertility effects persisted although the fish had a long remediation period, implying likely reduced fitness of fish populations in aquatic environments. Based on our findings on non-reproductive behaviours and fertility, we performed RNAsequencing analysis of the brain and testes in order to investigate possible biological mechanisms behind the persistent effects. There is a need for biomarkers allowing detection of both reversible and irreversible effects in animals exposed to estrogenic substances, hopefully contributing to better risk assessments for EDCs. Results from RNA-sequencing would serve as a basis for continued studies in pursuit of potential biomarkers.

    List of papers
    1. 17 alpha-Ethinyl estradiol affects anxiety and shoaling behavior in adult male zebra fish (Danio rerio)
    Open this publication in new window or tab >>17 alpha-Ethinyl estradiol affects anxiety and shoaling behavior in adult male zebra fish (Danio rerio)
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    2011 (English)In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 105, no 1-2, 41-48 p.Article in journal (Refereed) Published
    Abstract [en]

    Ethinyl estradiol is a potent endocrine disrupting compound in fish and ubiquitously present in the aquatic environment. In this study, we exposed adult zebra fish (Danio rerio) males to 0,5 or 25 ng Ethinyl estradiol/L for 14 days and analyzed the effects on non-reproductive behavior. Effects of treatment of the exposed males was shown by vitellogenin induction, while brain aromatase (CYP 19B) activity was not significantly altered. Both concentrations of Ethinyl estradiol significantly altered the behavior in the Novel tank test, where anxiety is determined as the tendency to stay at the bottom when introduced into an unfamiliar environment. The effects were, however, opposite for the two concentrations. Fish that were exposed to 5 ng/L had longer latency before upswim, fewer transitions to the upper half and shorter total time spent in the upper half compared with control fish, while 25 ng Ethinyl estradiol treatment resulted in shorter latency and more and longer visits to the upper half. The swimming activity of 25, but not 5 ng-exposed fish were slightly but significantly reduced, and these fish tended to spend a lot of time at the surface. We also studied the shoaling behavior as the tendency to leave a shoal of littermates trapped behind a Plexiglas barrier at one end of the test tank. The fish treated with Ethinyl estradiol had significantly longer latency before leaving shoal mates and left the shoal fewer times. Further, the fish exposed to 5 ng/L also spent significantly less time away from shoal than control fish. Fertilization frequency was higher in males exposed to 5 ng/L Ethinyl estradiol when compared with control males, while no spawning was observed after treatment with 25 ng/L The testes from both treatment groups contained a normal distribution of spermatogenesis stages, and no abnormality in testis morphology could be observed. In conclusion, we have observed effects on two behaviors not related to reproduction in zebra fish males after treatment with Ethinyl estradiol, adding to the ecological consequences of contamination of aquatic environments with estrogenic substances. (C) 2011 Elsevier B.V. All rights reserved.

    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-18647 (URN)10.1016/j.aquatox.2011.05.009 (DOI)000294317500005 ()
    Available from: 2011-09-30 Created: 2011-09-29 Last updated: 2017-12-08Bibliographically approved
    2. Short-term treatment of adult male zebrafish (Danio Rerio) with 17α-ethinyl estradiol affects the transcription of genes involved in development and male sex differentiation.
    Open this publication in new window or tab >>Short-term treatment of adult male zebrafish (Danio Rerio) with 17α-ethinyl estradiol affects the transcription of genes involved in development and male sex differentiation.
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    2014 (English)In: Comparative Biochemistry and Physiology - Part C: Toxicology & Pharmacology, ISSN 1532-0456, E-ISSN 1878-1659, Vol. 164, 35-42 p.Article in journal (Refereed) Published
    Abstract [en]

    The synthetic estrogen 17α-ethinyl estradiol (EE2) disturbs reproduction and causes gonadal malformation in fish. Effects on the transcription of genes involved in gonad development and function that could serve as sensitive biomarkers of reproductive effects in the field is, however, not well known. We have studied mRNA expression in testes and liver of adult zebrafish (Danio rerio) males treated with 0, 5 or 25ng/L EE2for 14days. qPCR analysis showed that the mRNA expression of four genes linked to zebrafish male sex determination and differentiation, Anti-Mullerian Hormone, Double sex and mab-related protein, Sry-related HMG box-9a and Nuclear receptor subfamily 5 group number 1b were significantly decreased by 25ng/L, but not 5ng/L EE2 compared with the levels in untreated fish. The decreased transcription was correlated with a previously shown spawning failure in these males (Reyhanian et al., 2011. Aquat Toxicol 105, 41-48), suggesting that decreased mRNA expression of genes regulating male sexual function could be involved in the functional sterility. The mRNA level of Cytochrome P-45019a, involved in female reproductive development, was unaffected by hormone treatment. The transcription of the female-specific Vitellogenin was significantly induced in testes. While testicular Androgen Receptor and the Estrogen Receptor-alpha mRNA levels were unchanged, Estrogen receptor-beta was significantly decreased by 25ng/L EE2. Hepatic Estrogen Receptor-alpha mRNA was significantly increased by both exposure concentrations, while Estrogen Receptor-beta transcription was unaltered. The decreased transcription of male-predominant genes supports a demasculinization of testes by EE2 and might reflect reproductive disturbances in the environment.

    Place, publisher, year, edition, pages
    New York: Elsevier, 2014
    Keyword
    17 alpha-Ethinyl estradiol; Biomarker; Endocrine disruptors; Gene regulation; Gonads; Sex differentiation; Zebrafish
    National Category
    Natural Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-35475 (URN)10.1016/j.cbpc.2014.04.003 (DOI)000337769100005 ()24747828 (PubMedID)2-s2.0-84899872779 (Scopus ID)
    Note

    Funding Agencies:

    Swedish Baltic Sea Foundation

    Stockholm County Council

    Available from: 2014-06-24 Created: 2014-06-24 Last updated: 2017-12-05Bibliographically approved
    3. Developmental exposure of zebrafish (Danio rerio) to 17 alpha-ethinylestradiol affects non-reproductive behavior and fertility as adults, and increases anxiety in unexposed progeny
    Open this publication in new window or tab >>Developmental exposure of zebrafish (Danio rerio) to 17 alpha-ethinylestradiol affects non-reproductive behavior and fertility as adults, and increases anxiety in unexposed progeny
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    2015 (English)In: Hormones and Behavior, ISSN 0018-506X, E-ISSN 1095-6867, Vol. 73, 30-38 p.Article in journal (Refereed) Published
    Abstract [en]

    Exposure to estrogenic endocrine disruptors (EDCs) during development affects fertility, reproductive and nonreproductive behavior in mammals and fish. These effects can also be transferred to coming generations. In fish, the effects of developmental EDC exposure on non-reproductive behavior are less well studied. Here, we analyze the effects of 17 alpha-ethinylestradiol (EE2) on anxiety, shoaling behavior and fertility in zebrafish after developmental treatment and remediation in clean water until adulthood. Zebrafish embryos were exposed from day 1 to day 80 post fertilization to actual concentrations of 1.2 and 1.6 ng/L EE2. After remediation for 82 days non-reproductive behavior and fertilization success were analyzed in both sexes. Males and females from the 1.2 ng/L group, as well as control males and females, were bred, and behavior of the untreated F1 offspring was tested as adults. Developmental treatment with 12 and 1.6 ng/L EE2 significantly increased anxiety in the novel tank test and increased shoaling intensity in both sexes. Fertilization success was significantly reduced by EE2 in both sexes when mated with untreated fish of opposite sex. Progeny of fish treated with 1.2 ng/L EE2 showed increased anxiety in the novel tank test and increased light avoidance in the scototaxis test compared to control offspring. In conclusion, developmental exposure of zebrafish to low doses of EE2 resulted in persistent changes in behavior and fertility. The behavior of unexposed progeny was affected by their parents' exposure, which might suggest transgenerational effects.

    Keyword
    Endocrine disruptors, 17 alpha-Ethinylestradiol, Stress behavior, Developmental exposure, Zebrafish, Neuroendocrinology, Social behavior, Anxiety, F1 effects, Fertility
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-45884 (URN)10.1016/j.yhbeh.2015.05.014 (DOI)000360251800005 ()26072466 (PubMedID)2-s2.0-84934983120 (Scopus ID)
    Note

    Funding Agency:

    Swedish Baltic Sea Foundation 1742/42/2008 1556/42/2011

    Available from: 2015-09-23 Created: 2015-09-21 Last updated: 2017-12-01Bibliographically approved
    4. Testis transcriptome alterations in zebrafish (Danio rerio) with reduced fertility due to developmental exposure to 17α-ethinyl estradiol
    Open this publication in new window or tab >>Testis transcriptome alterations in zebrafish (Danio rerio) with reduced fertility due to developmental exposure to 17α-ethinyl estradiol
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Biological Topics
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-47887 (URN)
    Available from: 2016-02-02 Created: 2016-02-02 Last updated: 2017-10-17Bibliographically approved
    5. Persistent effects of developmental exposure to 17α-ethinylestradiol on the zebrafish (Danio rerio) brain transcriptome and stress behavior
    Open this publication in new window or tab >>Persistent effects of developmental exposure to 17α-ethinylestradiol on the zebrafish (Danio rerio) brain transcriptome and stress behavior
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Zoology Biochemistry and Molecular Biology
    Identifiers
    urn:nbn:se:oru:diva-45958 (URN)
    Available from: 2015-09-30 Created: 2015-09-30 Last updated: 2017-10-17Bibliographically approved
  • 284.
    Caspillo, Nasim Reyhanian
    et al.
    Södertörn Univ, Sch Nat Sci Technol & Environm Studies, SE-14189 Huddinge, Sweden; Univ Örebro, Örebro Life Sci Ctr, Sch Sci & Technol, Örebro, Sweden.
    Volkova, Kristina
    Södertörn Univ, Sch Nat Sci Technol & Environm Studies, SE-14189 Huddinge, Sweden; Univ Örebro, Örebro Life Sci Ctr, Sch Sci & Technol, Örebro, Sweden.
    Hallgren, Stefan
    Södertörn Univ, Sch Nat Sci Technol & Environm Studies, Huddinge, Sweden.
    Olsson, Per-Erik
    Örebro University, School of Science and Technology.
    Porsch-Hällström, Inger
    Södertörn Univ, Sch Nat Sci Technol & Environm Studies, Huddinge, Sweden.
    Short-term treatment of adult male zebrafish (Danio Rerio) with 17α-ethinyl estradiol affects the transcription of genes involved in development and male sex differentiation.2014In: Comparative Biochemistry and Physiology - Part C: Toxicology & Pharmacology, ISSN 1532-0456, E-ISSN 1878-1659, Vol. 164, 35-42 p.Article in journal (Refereed)
    Abstract [en]

    The synthetic estrogen 17α-ethinyl estradiol (EE2) disturbs reproduction and causes gonadal malformation in fish. Effects on the transcription of genes involved in gonad development and function that could serve as sensitive biomarkers of reproductive effects in the field is, however, not well known. We have studied mRNA expression in testes and liver of adult zebrafish (Danio rerio) males treated with 0, 5 or 25ng/L EE2for 14days. qPCR analysis showed that the mRNA expression of four genes linked to zebrafish male sex determination and differentiation, Anti-Mullerian Hormone, Double sex and mab-related protein, Sry-related HMG box-9a and Nuclear receptor subfamily 5 group number 1b were significantly decreased by 25ng/L, but not 5ng/L EE2 compared with the levels in untreated fish. The decreased transcription was correlated with a previously shown spawning failure in these males (Reyhanian et al., 2011. Aquat Toxicol 105, 41-48), suggesting that decreased mRNA expression of genes regulating male sexual function could be involved in the functional sterility. The mRNA level of Cytochrome P-45019a, involved in female reproductive development, was unaffected by hormone treatment. The transcription of the female-specific Vitellogenin was significantly induced in testes. While testicular Androgen Receptor and the Estrogen Receptor-alpha mRNA levels were unchanged, Estrogen receptor-beta was significantly decreased by 25ng/L EE2. Hepatic Estrogen Receptor-alpha mRNA was significantly increased by both exposure concentrations, while Estrogen Receptor-beta transcription was unaltered. The decreased transcription of male-predominant genes supports a demasculinization of testes by EE2 and might reflect reproductive disturbances in the environment.

  • 285.
    Cavallo, Filippo
    et al.
    BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    Limosani, Raffaele
    BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    Manzi, Alessandro
    BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    Bonaccorsi, Manuele
    BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    Esposito, Raffaele
    BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    Di Rocco, Maurizio
    Örebro University, School of Science and Technology.
    Pecora, Federico
    Örebro University, School of Science and Technology.
    Teti, Giancarlo
    Robotech Srl, Peccioli, Italy.
    Saffiotti, Alessandro
    Örebro University, School of Science and Technology.
    Dario, Paolo
    BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    Development of a socially believable multi-robot solution from town to home2014In: Cognitive Computation, ISSN 1866-9956, E-ISSN 1866-9964, Vol. 6, no 4, 954-967 p.Article in journal (Refereed)
    Abstract [en]

    Technological advances in the robotic and ICT fields represent an effective solution to address specific societal problems to support ageing and independent life. One of the key factors for these technologies is that they have to be socially acceptable and believable to the end-users. This paper aimed to present some technological aspects that have been faced to develop the Robot-Era system, a multi-robotic system that is able to act in a socially believable way in the environments daily inhabited by humans, such as urban areas, buildings and homes. In particular, this paper focuses on two services-shopping delivery and garbage collection-showing preliminary results on experiments conducted with 35 elderly people. The analysis adopts an end-user-oriented perspective, considering some of the main attributes of acceptability: usability, attitude, anxiety, trust and quality of life.

  • 286.
    Cederstedt Johnsson, Linnea
    et al.
    Örebro University, School of Science and Technology.
    Henningsen, David
    Örebro University, School of Science and Technology.
    Konstruktion och optimering av vridhus till kran för virkeshantering2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project concerns the optimization and design of a slewing house for the machine manufacturer K.T.S Production. The slewing house is a technical solution that enables the crane to rotate using pinion and gear racks. This house is meant to be used in future releases of timber cranes which they intend to develop. The core of the problem was to compile a more durable and technologically advanced solution than the previous solutions manufactured by the company. As part of the more technologically advanced solution, rolling bearings have been used in the pinion gear attachment. The problem has been solved by dimensional calculations, comparisons of rolling bearings, material comparisons, modeling, casting adaption and stress analysis. In addition, topology optimization, a method for concept generation, has been used. A slewing house, adapted to the given conditions, has been developed. In this slewing house, tapered roller bearings has been valued as the best solution for the pinion gear attachment. Bearing models, materials and manufacturing methods have been proposed. On that basis, the company is expected to determine whether this concept is to be realized.

  • 287.
    Cehlin, Jesper
    Örebro University, School of Science and Technology.
    FÖRBÄTTRINGSARBETE PÅ BYGGARBETSPLATSER2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Wasting is a major problem on construction sites. A concept where the minimization of waste

    is central is called lean manufacturing. This essay aims to investigate how improvement work

    is used on construction sites. The current systems for improvement were analyzed and

    suggestions for improvement were given.

    Interviews were used to examine how improvement work on construction sites was used.

    Self-control and working preparations were used as quality systems on the construction sites.

    It turned out that they have no system for quality improvement. Because no system was used

    a system had to be developed from scratch.

    The PDCA-cycle is a method of improvement which forms the backbone of Lean. This

    method was the basis for the design of the improvement process. The company has

    procedures for the safety work that this improvement work adapted. The result was Quality

    Round which has a similar design as the company's safety and environmental rounds. The

    Quality round is used as health and environmental rounds once a week at the construction site

    where problem areas are identified and then specified in an FMEA-like template. The Quality

    round provides the opportunity to work with the entire PDCA-cycle on construction sites.

    To notice the problems and solving them is one thing, to ensure that the solutions are

    distributed and used is however more difficult. Standardization is a problem at construction

    sites because unlike in the industry business where the production is stationary the facilities

    are constantly moved depending on the projects location. Each project is unique and there is a

    constant exchange of staff and management. Working preparations used in the company

    could serve as method for standardization. The best method is selected and then described in

    detail with the amount of material, equipment, number of workers, etc. In order to add value

    so that even experienced staff will use these, they could also serve as checklists and

    calculation tools.

  • 288. Cesta, Amedeo
    et al.
    Cortellessa, Gabriella
    Giuliani, M. Vittoria
    Pecora, Federico
    Örebro University, School of Science and Technology.
    Scopelliti, Massimiliano
    Tiberio, Lorenza
    The RoboCare project: the user’s view2008In: Aging, disability and independence: selected papers from the 4th international conference on aging, disability and independence / [ed] William C. Mann, IOS Press, 2008, 85-104 p.Chapter in book (Refereed)
  • 289. Cesta, Amedeo
    et al.
    Fratini, Simone
    Oddi, Angelo
    Pecora, Federico
    Örebro University, School of Science and Technology.
    APSI Case# 1: pre-planning science operations in Mars Express2008In: iSAIRAS-08, 2008Conference paper (Refereed)
  • 290. Cesta, Amedeo
    et al.
    Fratini, Simone
    Pecora, Federico
    Örebro University, School of Science and Technology.
    Planning with multiple-components in OMPS2008In: New frontiers in applied artificial intelligence / [ed] Ngoc Thanh Nguyen, Leszek Borzemski, Adam Grzech, Moonis Ali, Springer Berlin/Heidelberg, 2008, 435-445 p.Conference paper (Refereed)
  • 291. Cesta, Amedeo
    et al.
    Fratini, Simone
    Pecora, Federico
    Örebro University, School of Science and Technology.
    Unifying planning and scheduling as timelines in a component-based perspective2008In: Archives of Control Science, ISSN 1230-2384, Vol. 18, no 2, 231-271 p.Article in journal (Refereed)
    Abstract [en]

    The timeline-based approach to planning represents an effective alternative to classical planning for complex domains requiring the use of both temporal reasoning and scheduling features. This paper discusses the constraint-based approach to timeline planning and scheduling introduced in OMPS.  OMPS is a an architecture for problem solving which draws inspiration from both control theory and constraint-based reasoning, and which is based on the notion of components.The rationale behind the component-based approach shares with classical control theory a basic modeling perspective: the planning and scheduling problem is represented by identifying a set of relevant domain components which need to be controlled to obtain a desired temporal behavior for the entire system. Components are entities whose properties may vary in time and which model one or more physical (or logical) domain subsystems relevant to a given planning context. The planner/scheduler plays the role of the controller for these entities, and reasons in terms of constraints that bound their internal evolutions and the desired properties of the generated behaviors (goals). Our work complements this modeling assumption with a constraint-based computational framework.  Admissible temporal behaviors of components are specified as a set of causal constraints within a rich temporal specification, and goals are specified as temporal constraint preferences.  The OMPS software architecture presented in this paper combines both specific and generic constraint solvers in defining consistent timelines which satisfy a given set of goals.

  • 292. Cesta, Amedeo
    et al.
    Pecora, Federico
    Örebro University, School of Science and Technology.
    The robocare project: multi-agent systems for the care of the elderly2003In: ERCIM News, ISSN 0926-4981, E-ISSN 1564-0094, no 53Article in journal (Other academic)
  • 293.
    Chadalavada, Ravi Teja
    et al.
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Krug, Robert
    Örebro University, School of Science and Technology.
    Lilienthal, Achim
    Örebro University, School of Science and Technology.
    Empirical evaluation of human trust in an expressive mobile robot2016In: Proceedings of RSS Workshop "Social Trust in Autonomous Robots 2016", 2016Conference paper (Refereed)
    Abstract [en]

    A mobile robot communicating its intentions using Spatial Augmented Reality (SAR) on the shared floor space makes humans feel safer and more comfortable around the robot. Our previous work [1] and several other works established this fact. We built upon that work by adding an adaptable information and control to the SAR module. An empirical study about how a mobile robot builds trust in humans by communicating its intentions was conducted. A novel way of evaluating that trust is presented and experimentally shown that adaption in SAR module lead to natural interaction and the new evaluation system helped us discover that the comfort levels between human-robot interactions approached those of human-human interactions.

  • 294.
    Chadalavada, Ravi Teja
    et al.
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Krug, Robert
    Örebro University, School of Science and Technology.
    Lilienthal, Achim
    Örebro University, School of Science and Technology.
    That’s on my Mind!: Robot to Human Intention Communication through on-board Projection on Shared Floor Space2015In: 2015 European Conference on Mobile Robots (ECMR), New York: IEEE conference proceedings , 2015Conference paper (Refereed)
    Abstract [en]

    The upcoming new generation of autonomous vehicles for transporting materials in industrial environments will be more versatile, flexible and efficient than traditional AGVs, which simply follow pre-defined paths. However, freely navigating vehicles can appear unpredictable to human workers and thus cause stress and render joint use of the available space inefficient. Here we address this issue and propose on-board intention projection on the shared floor space for communication from robot to human. We present a research prototype of a robotic fork-lift equipped with a LED projector to visualize internal state information and intents. We describe the projector system and discuss calibration issues. The robot’s ability to communicate its intentions is evaluated in realistic situations where test subjects meet the robotic forklift. The results show that already adding simple information, such as the trajectory and the space to be occupied by the robot in the near future, is able to effectively improve human response to the robot.

  • 295.
    Charusta, Krzysztof
    et al.
    Örebro University, School of Science and Technology.
    Krug, Robert
    Örebro University, School of Science and Technology.
    Dimitrov, Dimitar
    Örebro University, School of Science and Technology.
    Iliev, Boyko
    Örebro University, School of Science and Technology.
    Independent contact regions based on a patch contact model2012In: 2012 IEEE International Conference on Robotics and Automation (ICRA), IEEE conference proceedings, 2012, 4162-4169 p.Conference paper (Refereed)
    Abstract [en]

    The synthesis of multi-fingered grasps on nontrivial objects requires a realistic representation of the contact between the fingers of a robotic hand and an object. In this work, we use a patch contact model to approximate the contact between a rigid object and a deformable anthropomorphic finger. This contact model is utilized in the computation of Independent Contact Regions (ICRs) that have been proposed as a way to compensate for shortcomings in the finger positioning accuracy of robotic grasping devices. We extend the ICR algorithm to account for the patch contact model and show the benefits of this solution.

  • 296.
    Charusta, Krzysztof
    et al.
    Örebro University, School of Science and Technology.
    Krug, Robert
    Örebro University, School of Science and Technology.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Dimitrov, Dimitar
    Örebro University, School of Science and Technology.
    Iliev, Boyko
    Örebro University, School of Science and Technology.
    Generation of independent contact regions on objects reconstructed from noisy real-world range data2012In: 2012 IEEE International Conference on Robotics and Automation (ICRA), IEEE conference proceedings, 2012, 1338-1344 p.Conference paper (Refereed)
    Abstract [en]

    The synthesis and evaluation of multi-fingered grasps on complex objects is a challenging problem that has received much attention in the robotics community. Although several promising approaches have been developed, applications to real-world systems are limited to simple objects or gripper configurations. The paradigm of Independent Contact Regions (ICRs) has been proposed as a way to increase the tolerance to grasp positioning errors. This concept is well established, though only on precise geometric object models. This work is concerned with the application of the ICR paradigm to models reconstructed from real-world range data. We propose a method for increasing the robustness of grasp synthesis on uncertain geometric models. The sensitivity of the ICR algorithm to noisy data is evaluated and a filtering approach is proposed to improve the quality of the final result.

  • 297.
    Chatzidaki, Maria D.
    Örebro University, School of Science and Technology.
    Formulation and characterization of W/O nano-dispersions for bioactive delivery applications2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The main objective of this study was the formulation of food-grade water-in-oil (W/O) nano-dispersions based mainly on medium or long-chain triglycerides. Two types of dispersions were formulated and structurally compared, namely emulsions and microemulsions. The systems were used as matrices for encapsulating targeted bioactive molecules with specific characteristics such as antioxidants or peptides.

    The structural characterization of the formulated systems was investigated using techniques such as Electron Paramagnetic Resonance (EPR) spectroscopy, Dynamic Light Scattering (DLS), Cryogenic Transmission Electron Microscopy (Cryo-TEM) and Small Angle Xray Scattering (SAXS). The existence of swollen inverse micelles was revealed for the case of microemulsions whereas larger droplets still at the nano-scale were observed for the case of emulsions. Structural differences in the presence of the bioactive molecules or induced by the alteration of components were also observed.

    In order to study the efficacy of the formulations, the proposed loaded systems were assessed either using EPR spectroscopy or Well Diffusion Assay (WDA) depending on the bioactive molecule. It was found that the encapsulated molecules retained their claimed characteristics when encapsulated to the proposed matrices.

    Finally, some of the formulated dispersions were investigated for their behavior under gastrointestinal (GI) conditions. A two-step digestion model using recombinant Dog Gastric Lipase (rDGL) and Porcine Pancreatic Lipase (PPL) was proposed to simulate lipid hydrolysis in humans. The studies revealed significant decrease of the rDGL specific activity in the presence of the microemulsion while in the presence of lower percent of surfactants (case of emulsion) no alterations were observed.

    List of papers
    1. Low shear-rate process to obtain transparent W/O fine emulsions as functional foods
    Open this publication in new window or tab >>Low shear-rate process to obtain transparent W/O fine emulsions as functional foods
    Show others...
    2014 (English)In: Food Research International, ISSN 0963-9969, E-ISSN 1873-7145, Vol. 62, 533-540 p.Article in journal (Refereed) Published
    Abstract [en]

    Edible transparent emulsions of the water-in-oil (W/O) type are highly sought after and currently not available. In such materials, the water droplets can be advantageously used as reservoirs to encapsulate biologically active hydrophilic substances (minerals, antioxidants, etc.). The emulsions must remain transparent, fluid and kinetically stable to meet consumers' requirements. In this paper, we describe a simple yet versatile process to fabricate food grade transparent W/O emulsions. Our method involves the preparation of coarse emulsions which are submitted to shear under laminar flow conditions to reduce their average droplet size. The process generates negligible heat and consequently, it preserves the integrity of thermally sensitive compounds. The obtained emulsions contain between 5 and 10 wt.% of aqueous droplets whose average droplet size is lower than 200 nm. They are kinetically stable for at least 2 months. Transparency results from the relatively low droplet size and the incorporation in the aqueous phase of hydrophilic solutes that decrease the refractive index mismatch between the two immiscible phases.

    Place, publisher, year, edition, pages
    Elsevier, 2014
    Keyword
    W/O nanoemulsion, emulsification, coalescence, Ostwald ripening
    National Category
    Other Chemistry Topics
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-50112 (URN)10.1016/j.foodres.2014.03.069 (DOI)000340015100063 ()2-s2.0-84899521137 (Scopus ID)
    Available from: 2016-05-03 Created: 2016-05-03 Last updated: 2017-11-30Bibliographically approved
    2. Formulation and characterization of food-grade microemulsions as carriers of natural phenolic antioxidants
    Open this publication in new window or tab >>Formulation and characterization of food-grade microemulsions as carriers of natural phenolic antioxidants
    Show others...
    2015 (English)In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 483, 130-136 p.Article in journal (Refereed) Published
    Abstract [en]

    Food-grade W/O microemulsions based on lecithin, caprylic/capric triglycerides, isopropyl myristate, alcohols and water were formulated and structurally characterized to be used as potential carriers of natural food antioxidants. Different well-known food antioxidants including gallic acid, p-hydroxybenzoic acid, protocatechuic acid and tyrosol were successfully encapsulated in the aqueous cores of the microemulsions. A pseudo-ternary phase diagram was constructed to determine the extent of the monophasic area that corresponds to an inverted type microemulsion. Apparent hydrodynamic diameter measurements of empty and loaded microemulsions were performed using dynamic light scattering (DLS) and swollen micelles with diameters smaller than 10 nm were detected. Interfacial properties of the microemulsions were studied by electron paramagnetic resonance (EPR) spectroscopy employing the nitroxide spin probe 5-doxylstearic acid (5-DSA). A small increase in spin probe mobility upon addition of the antioxidants was observed; whereas the rigidity of the surfactants was not affected. Cryogenic transmission electron microscopy (Cryo-TEM) indicated the existence of entangled thread-like reversed micelles. Finally, the investigated phenolics were assessed and compared for their radical scavenging activity using an EPR approach based on free radicals. The encapsulated gallic acid showed the highest antioxidant activity (0.93 mM trolox equivalents) as compared to other antioxidants assessed within the frame of this study.

    Place, publisher, year, edition, pages
    Elsevier, 2015
    Keyword
    W/O microemulsion, Gallic acid, Antioxidant, EPR, DLS, Cryo-TEM
    National Category
    Other Chemistry Topics
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-50111 (URN)10.1016/j.colsurfa.2015.03.060 (DOI)000362146200017 ()2-s2.0-84941745179 (Scopus ID)
    Available from: 2016-05-03 Created: 2016-05-03 Last updated: 2017-11-30Bibliographically approved
    3. Microemulsion versus emulsion as effective carrier of hydroxytyrosol
    Open this publication in new window or tab >>Microemulsion versus emulsion as effective carrier of hydroxytyrosol
    Show others...
    2016 (English)In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 137, no 1, 146-151 p.Article in journal (Refereed) Published
    Abstract [en]

    Two edible Water-in-Oil (W/O) dispersions, an emulsion that remains kinetically stable and a microemulsion which is spontaneously formed, transparent and thermodynamically stable, were developed for potential use as functional foods, due to their ability to be considered as matrices to encapsulate biologically active hydrophilic molecules. Both systems contained Medium Chain Triglycerides (MCT) as the continuous phase and were used as carriers of Hydroxytyrosol (HT), a hydrophilic antioxidant of olive oil. A low energy input fabrication process of the emulsion was implemented. The obtained emulsion contained 1.3% (w/w) of surfactants and 5% (w/w) aqueous phase. The spontaneously formed microemulsion contained 4.9% (w/w) of surfactants and 2% (w/w) aqueous phase. A comparative study in terms of structural characterization of the systems in the absence and presence of HT was carried out. Particle size distribution obtained by Dynamic Light Scattering (DLS) technique and interfacial properties of the surfactants' layer, examined by Electron Paramagnetic Resonance (EPR) spectroscopy indicated the involvement of HT in the surfactant membrane. Finally, the proposed systems were studied for the scavenging activity of the encapsulated antioxidant toward galvinoxyl stable free radical showing a high scavenging activity of HT in both systems.

    Place, publisher, year, edition, pages
    Elsevier, 2016
    Keyword
    Emulsion, Microemulsion, Hydroxytyrosol, DLS, EPR, Antioxidant activity
    National Category
    Other Chemistry Topics
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-50110 (URN)10.1016/j.colsurfb.2015.04.053 (DOI)000367491200017 ()25999235 (PubMedID)2-s2.0-84951573458 (Scopus ID)
    Available from: 2016-05-03 Created: 2016-05-03 Last updated: 2017-11-30Bibliographically approved
    4. Microemulsions as potential carriers of nisin: effect of composition on the structure and efficacy
    Open this publication in new window or tab >>Microemulsions as potential carriers of nisin: effect of composition on the structure and efficacy
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Chemistry Topics
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-50113 (URN)
    Available from: 2016-05-04 Created: 2016-05-03 Last updated: 2017-10-17Bibliographically approved
    5. Water-in-Oil microemulsions versus emulsions as carriers of hydroxytyrosol: an in vitro gastrointestinal lipolysis study using the pHstat technique
    Open this publication in new window or tab >>Water-in-Oil microemulsions versus emulsions as carriers of hydroxytyrosol: an in vitro gastrointestinal lipolysis study using the pHstat technique
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Chemistry Topics
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-50119 (URN)
    Available from: 2016-05-04 Created: 2016-05-03 Last updated: 2017-10-17Bibliographically approved
  • 298.
    Chatzidaki, Maria D.
    et al.
    Örebro University, School of Science and Technology. Natl Hellen Res Fdn, Inst Biol Med Chem & Biotechnol, Athens 11635, Greece.
    Arik, Nehir
    Natl Hellen Res Fdn, Inst Biol Med Chem & Biotechnol, Athens 11635, Greece..
    Monteil, Julien
    Univ Bordeaux, CBMN, Lab Chim & Biol Membranes & Nanoobjets, Bordeaux, France..
    Papadimitriou, Vassiliki
    Natl Hellen Res Fdn, Inst Biol Med Chem & Biotechnol, Athens 11635, Greece..
    Leal-Calderon, Fernando
    Univ Bordeaux, CBMN, Lab Chim & Biol Membranes & Nanoobjets, Bordeaux, France..
    Xenakis, Aristotelis
    Natl Hellen Res Fdn, Inst Biol Med Chem & Biotechnol, Athens 11635, Greece.;Univ Orebro, Sch Sci & Technol, MTM Res Ctr, S-31705 Orebro, Sweden..
    Microemulsion versus emulsion as effective carrier of hydroxytyrosol2016In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 137, no 1, 146-151 p.Article in journal (Refereed)
    Abstract [en]

    Two edible Water-in-Oil (W/O) dispersions, an emulsion that remains kinetically stable and a microemulsion which is spontaneously formed, transparent and thermodynamically stable, were developed for potential use as functional foods, due to their ability to be considered as matrices to encapsulate biologically active hydrophilic molecules. Both systems contained Medium Chain Triglycerides (MCT) as the continuous phase and were used as carriers of Hydroxytyrosol (HT), a hydrophilic antioxidant of olive oil. A low energy input fabrication process of the emulsion was implemented. The obtained emulsion contained 1.3% (w/w) of surfactants and 5% (w/w) aqueous phase. The spontaneously formed microemulsion contained 4.9% (w/w) of surfactants and 2% (w/w) aqueous phase. A comparative study in terms of structural characterization of the systems in the absence and presence of HT was carried out. Particle size distribution obtained by Dynamic Light Scattering (DLS) technique and interfacial properties of the surfactants' layer, examined by Electron Paramagnetic Resonance (EPR) spectroscopy indicated the involvement of HT in the surfactant membrane. Finally, the proposed systems were studied for the scavenging activity of the encapsulated antioxidant toward galvinoxyl stable free radical showing a high scavenging activity of HT in both systems.

  • 299.
    Chatzidaki, Maria D.
    et al.
    Örebro University, School of Science and Technology. National Hellenic Research Foundation Institute of Biology Medicinal Chemistry and Biotechnology.
    Eduardo, Mateos-Diaz
    CNRS, UMR7282 Enzymologie Interfaciale et Physiologie de la Lipolyse.
    Leal-Calderon, Fernando
    Polytechnic Institute of Bourdeaux, CBMN.
    Xenakis, Aristotelis
    National Hellenic Research Foundation Institute of Biology Medicinal Chemistry and Biotechnology.
    Carrière, Frédéric
    CNRS, UMR7282 Enzymology at Interfaces and Physiology of Lipolysis.
    Water-in-Oil microemulsions versus emulsions as carriers of hydroxytyrosol: an in vitro gastrointestinal lipolysis study using the pHstat techniqueManuscript (preprint) (Other academic)
  • 300.
    Chatzidaki, Maria D.
    et al.
    Örebro University, School of Science and Technology. Natl Hellen Res Fdn, Inst Biol Med Chem & Biotechnol, Athens 11635, Greece.
    Mitsou, Evgenia
    Natl Hellen Res Fdn, Inst Biol Med Chem & Biotechnol, Athens 11635, Greece..
    Yaghmur, Anan
    Univ Copenhagen, Fac Hlth & Med Sci, Dept Pharm, DK-1168 Copenhagen, Denmark..
    Xenakis, Aristotelis
    Natl Hellen Res Fdn, Inst Biol Med Chem & Biotechnol, Athens 11635, Greece.;Univ Orebro, Sch Sci & Technol, MTM Res Ctr, Orebro, 31705, Sweden..
    Papadimitriou, Vassiliki
    Natl Hellen Res Fdn, Inst Biol Med Chem & Biotechnol, Athens 11635, Greece..
    Formulation and characterization of food-grade microemulsions as carriers of natural phenolic antioxidants2015In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 483, 130-136 p.Article in journal (Refereed)
    Abstract [en]

    Food-grade W/O microemulsions based on lecithin, caprylic/capric triglycerides, isopropyl myristate, alcohols and water were formulated and structurally characterized to be used as potential carriers of natural food antioxidants. Different well-known food antioxidants including gallic acid, p-hydroxybenzoic acid, protocatechuic acid and tyrosol were successfully encapsulated in the aqueous cores of the microemulsions. A pseudo-ternary phase diagram was constructed to determine the extent of the monophasic area that corresponds to an inverted type microemulsion. Apparent hydrodynamic diameter measurements of empty and loaded microemulsions were performed using dynamic light scattering (DLS) and swollen micelles with diameters smaller than 10 nm were detected. Interfacial properties of the microemulsions were studied by electron paramagnetic resonance (EPR) spectroscopy employing the nitroxide spin probe 5-doxylstearic acid (5-DSA). A small increase in spin probe mobility upon addition of the antioxidants was observed; whereas the rigidity of the surfactants was not affected. Cryogenic transmission electron microscopy (Cryo-TEM) indicated the existence of entangled thread-like reversed micelles. Finally, the investigated phenolics were assessed and compared for their radical scavenging activity using an EPR approach based on free radicals. The encapsulated gallic acid showed the highest antioxidant activity (0.93 mM trolox equivalents) as compared to other antioxidants assessed within the frame of this study.

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