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  • 1551.
    Riddell, Nicole
    et al.
    Örebro University, School of Science and Technology. Wellington Laboratories Inc., Guelph, Canada.
    Mullin, Lauren Gayle
    Örebro University, School of Science and Technology. Waters Corporation, Milford, USA.
    van Bavel, Bert
    Örebro University, School of Science and Technology. Norwegian Institute for Water Research, Oslo, Norway.
    Ericson Jogsten, Ingrid
    Örebro University, School of Science and Technology.
    McAlees, Alan
    Wellington Laboratories Inc., Guelph, Canada.
    Brazeau, Allison
    Wellington Laboratories Inc., Guelph, Canada.
    Synnott, Scott
    Wellington Laboratories Inc., Guelph, Canada.
    Lough, Alan
    Department of Chemistry, University of Toronto, Toronto, Canada.
    McCrindle, Robert
    Wellington Laboratories Inc., Guelph, Canada; Chemistry Department, University of Guelph, Guelph, Canada.
    Chittim, Brock
    Wellington Laboratories Inc., Guelph, Canada.
    Enantioselective Analytical- and Preparative-Scale Separation of Hexabromocyclododecane Stereoisomers Using Packed Column Supercritical Fluid Chromatography2016In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 21, no 11, article id 1509Article in journal (Refereed)
    Abstract [en]

    Hexabromocyclododecane (HBCDD) is an additive brominated flame retardant which has been listed in Annex A of the Stockholm Convention for elimination of production and use. It has been reported to persist in the environment and has the potential for enantiomer-specific degradation, accumulation, or both, making enantioselective analyses increasingly important. The six main stereoisomers of technical HBCDD (i.e., the (+) and (-) enantiomers of α-, β-, and γ-HBCDD) were separated and isolated for the first time using enantioselective packed column supercritical fluid chromatography (pSFC) separation methods on a preparative scale. Characterization was completed using published chiral liquid chromatography (LC) methods and elution profiles, as well as X-ray crystallography, and the isolated fractions were definitively identified. Additionally, the resolution of the enantiomers, along with two minor components of the technical product (δ- and ε-HBCDD), was investigated on an analytical scale using both LC and pSFC separation techniques, and changes in elution order were highlighted. Baseline separation of all HBCDD enantiomers was achieved by pSFC on an analytical scale using a cellulose-based column. The described method emphasizes the potential associated with pSFC as a green method of isolating and analyzing environmental contaminants of concern.

  • 1552.
    Riddell, Nicole
    et al.
    Örebro University, School of Science and Technology.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Ericson Jogsten, Ingrid
    Örebro University, School of Science and Technology.
    McCrindle, R.
    McAlees, A.
    Chittim, B.
    Negative Ion APCI Mechanisms Associated with the Coupling of Supercritical Fluid Chromatography to Mass Spectrometry for the Analysis of Halogenated Environmental Contaminants2016In: Organohalogen Compounds, ISSN 1026-4892, Vol. 78Article in journal (Refereed)
  • 1553.
    Riddell, Nicole
    et al.
    Örebro University, School of Science and Technology. Wellington Laboratories Inc., Guelph Ontario, Canada.
    van Bavel, Bert
    Örebro University, School of Science and Technology. Norwegian Institute for Water Research, Oslo, Norway.
    Ericson Jogsten, Ingrid
    Örebro University, School of Science and Technology.
    McCrindle, Robert
    Chemistry Department, University of Guelph, Guelph ON, Canada.
    McAlees, Alan
    Wellington Laboratories Inc., Guelph Ontario, Canada.
    Chittim, Brock
    Wellington Laboratories Inc., Guelph Ontario, Canada.
    Coupling of supercritical fluid chromatography to mass spectrometry for the analysis of Dechlorane Plus: Examination of relevant negative ion atmospheric pressure chemical ionization mechanisms2017In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 171, p. 68-73Article in journal (Refereed)
    Abstract [en]

    During an investigation of the potential associated with coupling packed column supercritical fluid chromatography (pSFC) to mass spectrometry for the analysis of Dechlorane Plus and related compounds, it was found that negative ion atmospheric pressure chemical ionization (APCI) was a promising ionization technique. In the course of maximizing the responses associated with the target analytes, it proved useful to examine some aspects of the complex nature and reactivity of the corona discharge plasma generated to explain the observed ionization products. Various dopants/reagents were screened for both APCI and atmospheric pressure photoionization (APPI) in negative ion mode and mechanisms of ionization involving superoxide were elucidated based on the results obtained. Superoxide formation was found to be temperature dependent and directly related to the intensity of the ion cluster [M-Cl+O](-) obtained for the target DP analytes. Furthermore, triethylamine was identified as a reagent capable of suppressing unwanted side reactions during the ionization process and maximizing response associated with the analytes of interest. The applicability of pSFC-APCI/MS for the separation and detection of Dechlorane Plus and related compounds was demonstrated by analyzing Lake Ontario sediment and comparing the results with values reported in the scientific literature.

  • 1554.
    Riddell, Nicole
    et al.
    Örebro University, School of Science and Technology. Wellington Laboratories Inc., Guelph, Ontario, Canada.
    van Bavel, Bert
    Örebro University, School of Science and Technology. Norwegian Institute for Water Research, Oslo, Norway.
    Ericson Jogsten, Ingrid
    Örebro University, School of Science and Technology.
    McCrindle, Robert
    Chemistry Department, University of Guelph, Guelph, ON, Canada.
    McAlees, Alan
    Wellington Laboratories Inc., Guelph, Ontario, Canada.
    Chittim, Brock
    Wellington Laboratories Inc., Guelph, Ontario, Canada.
    Coupling of Supercritical Fluid Chromatography to Mass Spectrometry for the Analysis of Dechlorane Plus: Examination of Relevant Negative Ion Atmospheric Pressure Chemical Ionization MechanismsManuscript (preprint) (Other academic)
  • 1555.
    Riddell, Nicole
    et al.
    Örebro University, School of Science and Technology. Wellington Laboratories Inc., Guelph, Ontario, Canada.
    van Bavel, Bert
    Örebro University, School of Science and Technology. Norwegian Institute for Water Research, Oslo, Norway.
    Ericson Jogsten, Ingrid
    Örebro University, School of Science and Technology.
    McCrindle, Robert
    Chemistry Department, University of Guelph, Guelph, ON, Canada.
    McAlees, Alan
    Wellington Laboratories Inc., Guelph, Ontario, Canada.
    Chittim, Brock
    Wellington Laboratories Inc., Guelph, Ontario, Canada.
    Coupling Supercritical Fluid Chromatography to Positive Ion Atmospheric Pressure Ionization Mass Spectrometry: Ionization Optimization of Halogenated Environmental ContaminantsManuscript (preprint) (Other academic)
  • 1556.
    Riddell, Nicole
    et al.
    Wellington Laboratories Inc., Guelph ON, Canada; Man-Technology-Environment (MTM) Research Center, Örebro University, Örebro, Sweden.
    van Bavel, Bert
    Örebro University, School of Science and Technology. Norwegian Institute for Water Research, Oslo, Norway.
    Ericson Jogsten, Ingrid
    Örebro University, School of Science and Technology.
    McCrindle, Robert
    Chemistry Department, University of Guelph, Guelph, Canada.
    McAlees, Alan
    Wellington Laboratories Inc., Guelph ON, Canada.
    Chittim, Brock
    Wellington Laboratories Inc., Guelph ON, Canada.
    Coupling supercritical fluid chromatography to positive ion atmospheric pressure ionization mass spectrometry: Ionization optimization of halogenated environmental contaminants2017In: International Journal of Mass Spectrometry, ISSN 1387-3806, E-ISSN 1873-2798, Vol. 421, p. 156-163Article in journal (Refereed)
    Abstract [en]

    Currently used analytical techniques for halogenated aromatic environmental contaminants such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs), also known as legacy persistent organic pollutants, are based on gas chromatographic separation of target analytes and detection by mass spectrometry. The coupling of packed column supercritical fluid chromatography (SFC) to atmospheric pressure ionization mass spectrometry (API/MS) could allow for the concurrent analysis of thermally labile and legacy halogenated environmental contaminants if ionization can be sufficiently optimized. The evaluation of positive ion atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) as well as possible charge transfer dopants for the generation of molecular ion isotopomeric clusters of halogenated environmental contaminants with minimal fragmentation has been completed. Using the investigated parameters, positive ion APPI was found to be the more sensitive technique. Of the aromatic and cycloalkane dopants investigated, only fluorobenzene and trifluorotoluene were found to be effective dopants for the halogenated aromatic target analytes (PCDDs, PCDFs, and PCBs). Experiments involving deuterated dopants confirmed that reactive species generated by cycloalkanes were quenched by the SFC eluent rendering them unusable in conjunction with the investigated separation technique. Alternatively, aromatic dopants were found to be less susceptible to quenching by the SFC eluent and fluorobenzene was determined to be the most effective charge transfer dopant for PCDDs, PCDFs, and PCBs. To demonstrate the applicability of the optimized ionization conditions, SFC-API/MS has been used for the concurrent analysis of legacy halogenated aromatic environmental contaminants (PCDDs, PCDFs, and PCBs) and thermally labile analytes (alpha, beta, and gamma isomers of hexabromocyclododecane).

  • 1557.
    Riddell, Nicole
    et al.
    Örebro University, School of Science and Technology. Wellington Laboratories Inc., Guelph ON, Canada.
    van Bavel, Bert
    Örebro University, School of Science and Technology. Norwegian Institute for Water Research, Oslo, Norway.
    Ericson Jogsten, Ingrid
    Örebro University, School of Science and Technology.
    McCrindle, Robert
    Wellington Laboratories Inc., Guelph ON, Canada; Chemistry Department, University of Guelph, Guelph ON, Canada.
    McAlees, Alan
    Wellington Laboratories Inc., Guelph ON, Canada.
    Chittim, Brock
    Wellington Laboratories Inc., Guelph ON, Canada.
    Examination of technical mixtures of halogen-free phosphorus based flame retardants using multiple analytical techniques2017In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 176, no June 2017, p. 333-341Article in journal (Refereed)
    Abstract [en]

    The application of phosphorus based flame retardants as replacements for commonly used halogenated flame retardants has been gaining interest due to the possibility that these compounds may have a less significant impact on human and environmental health. Unfortunately, little is known about the chemical compositions of many of the technical products (which often are mixtures) and a single separation technique for concurrent analysis of these types of compounds has not been identified. This paper reports the results of an investigation into the constituents of three halogen free organophosphate flame retardants (OPFRs), resorcinol bis(diphenyl phosphate) (RDBPP), bisphenol A bis(diphenyl phosphate) (BPA-BDPP), and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). The major components of commercial samples of RDBPP and BPA-BDPP were isolated by preparative TLC and characterized by NMR. A commercial sample of DOPO was found to be essentially pure, but its analysis is complicated by the fact that it can exist in ring-open and ring-closed forms. With the structures of the components confirmed by NMR, multiple analytical separation techniques (gas chromatography (GC), liquid chromatography (LC), and packed column supercritical fluid chromatography (pSFC)) were investigated for the analysis of these three technical products. Packed column supercritical fluid chromatography allows the separation of the components of all three OPFRs, including the two forms of DOPO, in a single run.

  • 1558.
    Riddell, Nicole
    et al.
    Örebro University, School of Science and Technology. Wellington Laboratories Inc., Guelph, Canada.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Jogsten, Ingrid Ericson
    Örebro University, School of Science and Technology.
    McCrindle, Robert
    Chemistry Department, University of Guelph, Guelph ON, Canada.
    McAlees, Alan
    Wellington Laboratories Inc., Guelph, Canada.
    Potter, Dave
    Wellington Laboratories Inc., Guelph, Canada.
    Tashiro, Colleen
    Wellington Laboratories Inc., Guelph, Canada.
    Chittim, Brock
    Wellington Laboratories Inc., Guelph, Canada.
    Comparative assessment of the chromatographic separation of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans using supercritical fluid chromatography and high resolution gas chromatography2015In: Analytical Methods, ISSN 1759-9660, E-ISSN 1759-9679, Vol. 7, no 21, p. 9245-9253Article in journal (Refereed)
    Abstract [en]

    The analysis of legacy environmental contaminants, such as polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), using high resolution gas chromatography (HRGC) is well established and universally accepted. The use of an alternative separation technique, such as packed column supercritical fluid chromatography (pSFC), may be of interest as a fast, green, and cost effective method of analyzing environmental samples. The technique is amenable to a broad range of chemical compounds and could facilitate the simultaneous analysis of multiple compound classes as well as the inclusion of thermally labile compounds in a single targeted analysis. The recent re-emergence of this technology due to the introduction of more robust and efficient instrumentation may result in an increased acceptance of pSFC analytical techniques in this area. Herein, the first reported analytical separation of PCDDs and PCDFs by pSFC is described and its separation capabilities are compared with established HRGC protocols. Elution profiles of 2,3,7,8-substituted PCDDs and PCDFs were examined and the separation of PCDD/PCDF homologue groups was found to be comparable to those accomplished using HRGC. Similarly, the resolution of tetrachlorodibenzo-p-dioxin (TCDD) congeners, as required by current regulatory methods utilizing HRGC, was demonstrated and the separation of possible co-eluting PCDD/PCDF congeners was examined and compared to that achieved using popular HRGC capillary columns. The possibility of concurrent analysis of toxic polychlorinated biphenyls (PCBs) with PCDDs and PCDFs using the developed pSFC method was also investigated. The effective separation of these environmental contaminants obtained using pSFC and subsequent detection utilizing atmospheric pressure photoionization tandem mass spectrometry at environmentally relevant levels demonstrates the promise associated with this technique for the analysis of environmental extracts.

  • 1559.
    Ristinmaa, Matti
    et al.
    Division of Solid Mechanics, Lund University, Lund, Sweden.
    Saabye Ottosen, Niels
    Division of Solid Mechanics, Lund University, Lund, Sweden.
    Korin, Christer
    Örebro University, School of Science and Technology.
    Analytical Prediction of Package Collapse Loads: Basic considerations2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, no 4, p. 806-813Article in journal (Refereed)
    Abstract [en]

    Calculation of Box Compression Resistance (BCR) is a challenging task and here the possibility of an engineering approach is considered. The strive has been towards obtaining a simple and general predictive tool with as few parameters as possible and still obtaining an accurate estimate of the BCR. The model proposed is based on the concept of dividing the package into panels and corner panels. With these remarkably few structural elements it is possible to obtain simple explicit formulas where the only material parameters are given by standard tests in terms of short span compression test and bending resistance. The BCR for different packages is then obtained by a simply summation of the load from the panels and corner panels. A validation against experimental data indicates that, despite its remarkably simplicity, the predictions are very accurate for a wide range of package types, package dimensions, board qualities and loading directions.

  • 1560.
    Rituerto, Alejandro
    et al.
    Instituto de Investigación en Ingeniería de Aragón, Deptartmento de Informática e Ingeniería de Sistemas, University of Zaragoza, Zaragoza, Spain.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Murillo, Ana C.
    Instituto de Investigación en Ingeniería de Aragón, Deptartmento de Informática e Ingeniería de Sistemas, University of Zaragoza, Zaragoza, Spain.
    Lilienthal, Achim
    Örebro University, School of Science and Technology.
    Jesus Guerrero, Jose
    Instituto de Investigación en Ingeniería de Aragón, Deptartmento de Informática e Ingeniería de Sistemas, University of Zaragoza, Zaragoza, Spain.
    Building an Enhanced Vocabulary of the Robot Environment with a Ceiling Pointing Camera2016In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 16, no 4, article id 493Article in journal (Refereed)
    Abstract [en]

    Mobile robots are of great help for automatic monitoring tasks in different environments. One of the first tasks that needs to be addressed when creating these kinds of robotic systems is modeling the robot environment. This work proposes a pipeline to build an enhanced visual model of a robot environment indoors. Vision based recognition approaches frequently use quantized feature spaces, commonly known as Bag of Words (BoW) or vocabulary representations. A drawback using standard BoW approaches is that semantic information is not considered as a criteria to create the visual words. To solve this challenging task, this paper studies how to leverage the standard vocabulary construction process to obtain a more meaningful visual vocabulary of the robot work environment using image sequences. We take advantage of spatio-temporal constraints and prior knowledge about the position of the camera. The key contribution of our work is the definition of a new pipeline to create a model of the environment. This pipeline incorporates (1) tracking information to the process of vocabulary construction and (2) geometric cues to the appearance descriptors. Motivated by long term robotic applications, such as the aforementioned monitoring tasks, we focus on a configuration where the robot camera points to the ceiling, which captures more stable regions of the environment. The experimental validation shows how our vocabulary models the environment in more detail than standard vocabulary approaches, without loss of recognition performance. We show different robotic tasks that could benefit of the use of our visual vocabulary approach, such as place recognition or object discovery. For this validation, we use our publicly available data-set.

  • 1561.
    Rivas Diaz, Juan Manuel
    Örebro University, School of Science and Technology.
    Model-based object tracking with an infrared stereo camera2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Object tracking has become really important in the field of robotics in the last

    years. Frequently, the goal is to obtain the trajectory of the tracked target over

    time and space by acquiring and processing information from the sensors.

    In this thesis we are interested in tracking objects at a very short range. The

    primary application of our approach is targeting the domain of object tracking

    during grasp execution with a hand-in-eye sensor setup. To this end, a

    promising approach investigated in this work is based on the Leap Motion

    sensor, which is designed for tracking human hands. However, we are

    interested in tracking grasped objects thus we need to extend its functionality.

    The main goal of the thesis is to track the 3D position and orientation of an

    object from a set of simple primitives (cubes, cylinders, triangles) over a video

    sequence. That is the reason we have designed and developed two different

    approaches for tracking objects with the Leap Motion device as stereo vision

    system.

  • 1562.
    Rockel, Sebastian
    et al.
    University of Hamburg, Hamburg, Germany.
    Konečný, Štefan
    Örebro University, School of Science and Technology.
    Stock, Sebastian
    Osnabrück University, Osnabrück, Germany; DFKI Robotics Innovation Center, Osnabrück, Germany.
    Hertzberg, Joachim
    Osnabrück University, Osnabrück, Germany; DFKI Robotics Innovation Center, Osnabrück, Germany.
    Pecora, Federico
    Örebro University, School of Science and Technology.
    Zhang, Jianwei
    University of Hamburg, Hamburg, Germany.
    Integrating physics-based prediction with semantic plan execution monitoring2015In: 2015 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS), IEEE , 2015, p. 2883-2888Conference paper (Refereed)
    Abstract [en]

    Real-world robotic systems have to deal with uncertain and dynamic environments to reliably perform tasks. State-of-the-art cognitive robotic systems use an abstract symbolic representation of the real world that is used for high level reasoning. Some aspects of the world, such as object dynamics, are inherently difficult to capture in an abstract symbolic form, yet they influence whether the executed action will succeed or fail. This paper presents an integrated system that uses a physics-based simulation for predicting robot action results and durations, combined with a Hierarchical Task Network (HTN) planner and semantic execution monitoring. We describe a fully integrated system performing functional imagination, which is essentially contributed by a Semantic Execution Monitor (SEM). Based on information obtained from functional imagination, the robot control decides whether it is necessary to adapt the plan that is currently being executed. As a proof of concept, we demonstrate PR2 able of carrying objects on a tray without the objects toppling. Our approach achieves this by considering the robot and object dynamics in simulation. A validation shows that robot action results in simulation can be transferred to the real world. The system improves on state-of-the-art AI plan-based systems by feeding simulated prediction results back into the execution system.

  • 1563.
    Rodesten, Stephan
    Örebro University, School of Science and Technology.
    Program för frekvensanalys2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report will cover the work process behind creating a spectrum analyzer. The reader will be able to read about the chosen method but also the alternative methods. Apart from this the theoretical parts behind every moment will also be covered and compared to potential alternative solutions.

    The project has been carried out on behalf of KA Automation. The purpose of the project was to create a base for analyzing sound frequencies. The goal was to be able to identify sound properties in the form of frequencies in servo motors in for example water pumps. The idea was to be able to in a later development stage be able to identify when new frequencies have entered the audio profile which might result in the motor to be in need of service. The base is created with the help of C# and the sound library NAudio.

    From the result one can conclude that this program can analyze sound and display the magnitude of its frequency components and is therefore a suitable base for future development.

  • 1564.
    Rodriguez-Calzada, Tania
    et al.
    Autonomos University of Querétaro, Santiago de Querétaro, Mexiko.
    Qian, Minjie
    Örebro University, School of Science and Technology.
    Strid, Åke
    Örebro University, School of Science and Technology.
    Neugart, Susanne
    Leibniz Institute for Vegetable and Ornamental Plants, Großbeeren, Germany.
    Schreiner, Monika
    Leibniz Institute for Vegetable and Ornamental Plants, Großbeeren, Germany.
    Torres-Pacheco, Ireno
    Autonomos University of Querétaro, Santiago de Querétaro, Mexiko.
    Guevara-Gonzales, Ramon
    Autonomos University of Querétaro, Santiago de Querétaro, Mexiko.
    Effect of UV-B radiation on morphology, phenolic compound production, gene expression, and subsequent drought stress responses in chili pepper (Capsicum annuum L.)2018In: Plant physiology and biochemistry (Paris), ISSN 0981-9428, E-ISSN 1873-2690Article in journal (Refereed)
    Abstract [en]

    It has been suggested that accumulation of flavonoids could be a key step in development of plant tolerance to different environmental stresses. Moreover, it has been recognized that abiotic stresses such as drought and UV-B radiation (280-315 nm) induce phenolic compound accumulation, suggesting a role for these compounds in drought tolerance. The aim of the present study was to evaluate the effect of UV-B exposure on chili pepper (Capsicum annuum, cv. ‘Coronel’) plant performance, phenolic compound production, and gene expression associated with response to subsequent drought stress. Additionally, the phenotypic response to drought stress of these plants was studied. UV-B induced a reduction both in stem length, stem dry weight and number of floral primordia. The largest reduction in these variables was observed when combining UV-B and drought. UV-B-treated well-watered plants displayed fructification approximately 1 week earlier than non-UV-B-treated controls. Flavonoids measured epidermally in leaves significantly increased during UV-B treatment. Specifically, UV-B radiation significantly increased chlorogenic acid and apigenin 8-C-hexoside levels in leaves and a synergistic increase of luteolin 6-C-pentoside-8-C-hexoside was obtained by UV-B and subsequent drought stress. Gene expression of phenylalanine ammonia lyase (PAL) and chalcone synthase (CHS) genes also increased during UV-B treatments. On the other hand, expression of genes related to an oxidative response, such as mitochondrial Mn-superoxide dismutase (Mn-SOD) and peroxidase (POD) was not induced by UV-B. Drought stress in UV-B-treated plants induced mitochondrial Mn-SOD gene expression. Taken together, the UV-B treatment did not induce significant tolerance in plants towards drought stress under the conditions used.

  • 1565.
    Rolf, Matilda
    et al.
    Örebro University, School of Science and Technology.
    Källberg, Maja
    Örebro University, School of Science and Technology.
    Effektivisering av fönstermontage hos AB Strängbetong2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is a case study at the company AB Strängbetong. The company manufactures wall elements in prefabricated concrete. Today, the company has a problem with its window assembly. Forecasts show that the company expects a volume increase on the option of assemble windows. The purpose of this study is to provide a complete survey of Strängbetong's window assembly, suggestions for solutions for an efficient working method and possibly develop a standardized approach. The process needs to be streamlined to cope with this. This study is based on a number of different theories. Among other things Lean, with focusing on eliminating waste in the process.

    Following a survey of the window assembly department, solutions are presented that will help to reduce waste in the process. Two solutions are presented, of which Solution 1 can be done without the need to use economic resources. Solution 2 is presented as a longer term solution and requires the company to invest in new areas and tools. The two suggested solution are expected to reduce wastes, which means that Strängbetong's window assembly process becomes more efficient and is considered ready for future volume increases.

  • 1566.
    Romin, Alexander
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Anton
    Örebro University, School of Science and Technology.
    Grip stiffness analysis of carton board packages2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is a part of the research project "A New Model for Deformation of Carton Board Packages by Manual Handling". This project is a collaboration between Örebro University and two companies engaged in carton board packages. This report describes whether Syntouch's BioTac is an appropriate tool, compared with a consumer study when investigating the grip stiffness of consumer packaging. Syntouch's BioTac is an artificial sensor designed to imitate the force of a human fingertip. The concept of grip stiffness is used in the packaging industry to describe the packaging’s properties to withstand clamping pressure when handling by the user. That is, the robustness of the packaging. The carton board packaging should perceive as stiff, firm to grip and not deform during handling. The purpose is to perform laboratory tests with the BioTac sensor, to see if the sensor can be used as a measurement method for grip stiffness of card board materials.

  • 1567.
    Roos, Vendela
    et al.
    Occupational and Environmental Medicine, Uppsala University, Uppsala, Sweden.
    Rönn, Monika
    Occupational and Environmental Medicine, Uppsala University, Uppsala, Sweden.
    Salihovic, Samira
    Örebro University, School of Science and Technology.
    Lind, Lars
    Department of Medicine, Uppsala University, Uppsala, Sweden.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Kullberg, Joel
    Department of Oncology, Radiology and Clinical Immunology, Uppsala University, Uppsala, Sweden.
    Johansson, Lars
    Dept Oncol Radiol & Clin Immunol, Uppsala, Sweden; Department of Oncology, Radiology and Clinical Immunology, Uppsala University, Uppsala, Sweden.
    Ahlström, Håkan
    Department of Oncology, Radiology and Clinical Immunology, Uppsala University, Uppsala, Sweden.
    Lind, P. Monica
    Occupational and Environmental Medicine, Uppsala University, Uppsala, Sweden.
    Circulating Levels of Persistent Organic Pollutants in Relation to Visceral and Subcutaneous Adipose Tissue by Abdominal MRI2013In: Obesity, ISSN 1930-7381, E-ISSN 1930-739X, Vol. 21, no 2, p. 413-418Article in journal (Refereed)
    Abstract [en]

    Objective: We and others have shown relationships between circulating levels of persistent organic pollutants (POPs) and different measures of obesity in both cross-sectional and prospective studies. Since viscerally located fat seems to be the most harmful type, we investigated whether plasma POP levels were more closely related to visceral adipose tissue (VAT) than to subcutaneous adipose tissue (SAT).

    Design and Methods: Thousand hundred and sixteen subjects aged 70 years were investigated in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study; 23 POPs were analyzed using high-resolution gas chromatography/ high-resolution mass spectrometry. Abdominal magnetic resonance imaging, measuring VAT and SAT, respectively, was performed in a representative subsample of 287 subjects.

    Results: The less chlorinated polychlorinated biphenyl (PCB) congeners (105 and 118), and the pesticides dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), and trans-nonachlordane (TNC) were positively related to both VAT and SAT, whereas the more highly chlorinated PCBs (153, 156, 157, 169, 170, 180, 194, 206, and 209) were inversely related to both VAT and SAT. PCB189 was related to the VAT/SAT ratio in an inverted U-shaped manner (P = 0.0008).

    Conclusions: In conclusion, the results were in accordance with our previous studies using waist circumference and fat mass as obesity measure. However, the novel finding that PCB189 was related to the VAT/SAT ratio deserves further investigation since exposure to this PCB congener, which has previously been linked to diabetes development, might thereby play a role in the distribution of abdominal adipose tissue.

  • 1568.
    Rosell, Andreas
    et al.
    Örebro University, School of Science and Technology.
    Salomonsson, Ludvig
    Örebro University, School of Science and Technology.
    Analys av kvalitetsbristkostnader: En studie som belyser konsekvenserna av bristande kvalitet2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The harsh competition the producing organizations face these days, sets high expectations concerning effectivity, profitability and process development. To improve the organization is an essential part for survival. In order to successfully improve your organization you should first identify what process that’s in dire need. This can be achieved by identifying, analyzing and eliminating the wastes inside the company. This report sets the foundation for future improvements by identifying the locations, reasons and economic consequences of waste. A case study whose purpose was to analyze an activity which didn’t add value for the customer was performed to reveal additional areas of improvement. Through interviews, observations and studies of documented data, a new model for the registration system was created. These methods were also used to create an updated version of their internal price list. A case study were performed where two batches of meat, from different suppliers, were followed through processing. The purpose were to examine whether there is a link between supplier quality and increment of cost. Parameter such as time spent in stock, resource consumption and loss of weight where observed. The model combined with the price list can be used as a basis for future decisions regarding improvements. The case study demonstrates the consequences associated with a functional oriented business approach.

  • 1569.
    Rosenlund, Angelica
    et al.
    Örebro University, School of Science and Technology.
    Gren, Pia
    Örebro University, School of Science and Technology.
    Framtagning av en ny sårhake2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The thesis was carried out in cooperation with the company ProboNova Medical Innovation AB. ProboNova works mainly with the concept development of medical devices. Then they take a Provisional Patent Application on the concept and licensing it out to a larger company. By licensing out the concepts they don’t have to take the costs of clinical trials for example.  

    The thesis was founded in that ProboNova wanted help with developing a concept on a new surgical retractor. The project has been characterized by the design process in which the feasibility studies and brainstorming has been the main parts. At the end of the project a concept was presented. The final concept met all the requirements from ProboNova and from the functional analysis that was done in the feasibility studies. A Provisional Patent Application was taken later on the final concept.   

    The idea is that the thesis should give the reader a better understanding of how to work with the design process, and learn the benefits of choosing a Provisional Patent Application instead of a Nonprovisional application.

  • 1570.
    Rotander, Anna
    et al.
    National Research Centre for Environmental Toxicology (Entox), The University of Queensland, Coopers Plains QLD, Australia.
    Kärrman, Anna
    Örebro University, School of Science and Technology.
    Toms, Leisa-Maree L.
    School of Clinical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane QLD, Australia.
    Kay, Margaret
    Discipline of General Practice, Royal Brisbane and Women’s Hospital Complex, University of Queensland, Herston QLD, Australia.
    Mueller, Jochen F.
    National Research Centre for Environmental Toxicology (Entox), The University of Queensland, Coopers Plains QLD, Australia.
    Gómez Ramos, María José
    National Research Centre for Environmental Toxicology (Entox), The University of Queensland, Coopers Plains QLD, Australia.
    Novel fluorinated surfactants tentatively identified in firefighters using liquid chromatography quadrupole time-of-flight tandem mass spectrometry and a case-control approach2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 4, p. 2434-2442Article in journal (Refereed)
    Abstract [en]

    Fluorinated surfactant-based aqueous film-forming foams (AFFFs) are made up of per- and polyfluorinated alkyl substances (PFAS) and are used to extinguish fires involving highly flammable liquids. The use of perfluorooctanesulfonic acid (PFOS) and other perfluoroalkyl acids (PFAAs) in some AFFF formulations has been linked to substantial environmental contamination. Recent studies have identified a large number of novel and infrequently reported fluorinated surfactants in different AFFF formulations. In this study, a strategy based on a case-control approach using quadrupole time-of-flight tandem mass spectrometry (QTOF-MS/MS) and advanced statistical methods has been used to extract and identify known and unknown PFAS in human serum associated with AFFF-exposed firefighters. Two target sulfonic acids [PFOS and perfluorohexanesulfonic acid (PFHxS)], three non-target acids [perfluoropentanesulfonic acid (PFPeS), perfluoroheptanesulfonic acid (PFHpS), and perfluorononanesulfonic acid (PFNS)], and four unknown sulfonic acids (Cl-PFOS, ketone-PFOS, ether-PFHxS, and Cl-PFHxS) were exclusively or significantly more frequently detected at higher levels in firefighters compared to controls. The application of this strategy has allowed for identification of previously unreported fluorinated chemicals in a timely and cost-efficient way.

  • 1571.
    Rotander, Anna
    et al.
    Örebro University, School of Science and Technology.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Rigét, Frank
    University of Aarhus, Roskilde, Denmark.
    Atli Audunsson, Gudjón
    Innovation Center Iceland, Reykjavik, Iceland.
    Polder, Anuschka
    Norwegian School of Veterinary Science, Oslo, Norway .
    Wing Gabrielsen, Geir
    FRAM Centre, Norwegian Polar Institute, Tromsø, Norway.
    Vikingsson, Gisli
    Marine Research Institute, Reykjavík, Iceland.
    Mikkelsen, Bjarni
    Museum of Natural History, Torshavn, Faroe Islands.
    Dam, Maria
    Environment Agency, Argir, Faroe Islands.
    Polychlorinated naphthalenes (PCNs) in sub-Arctic and Arctic marine mammals, 1986-20092012In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 164, p. 118-124Article in journal (Refereed)
    Abstract [en]

    A selection of PCN congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbour porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). A large geographical area of the North Atlantic and Arctic areas was covered. PCN congeners 48, 52, 53, 66 and 69 were found in the blubber samples between 0.03 and 5.9 ng/g lw. Also PCBs were analyzed in minke whales and fin whales from Iceland and the total PCN content accounted for 0.2% or less of the total non-planar PCB content. No statistically significant trend in contaminant levels could be established for the studied areas. However, in all species except minke whales caught off Norway the lowest Sigma PCN concentrations were found in samples from the latest sampling period.

  • 1572.
    Roussou, Alexandra
    et al.
    Department of Applied Mathematics, University of Crete, Heraklion, Greece.
    Smyrnakis, Ioannis
    Technological Education Institute of Crete, Heraklion, Greece.
    Magiropoulos, Manolis
    Technological Education Institute of Crete, Heraklion, Greece.
    Efremidis, Nikolaos
    Department of Applied Mathematics, University of Crete, Heraklion, Greece.
    Kavoulakis, Georgios
    Technological Education Institute of Crete, Heraklion, Greece.
    Sandin, Patrik
    Örebro University, School of Science and Technology.
    Ögren, Magnus
    Örebro University, School of Science and Technology.
    Gulliksson, Mårten
    Örebro University, School of Science and Technology.
    Excitation spectrum of a mixture of two Bose gases confined in a ring potential with interaction asymmetry2018In: New Journal of Physics, ISSN 1367-2630, E-ISSN 1367-2630, Vol. 20, article id 045006Article in journal (Refereed)
    Abstract [en]

    We study the rotational properties of a two-component Bose-Einstein condensed gas of distinguishable atoms which are confined in a ring potential using both the mean-field approximation, as well as the method of diagonalization of the many-body Hamiltonian. We demonstrate that the angular momentum may be given to the system either via single-particle, or "collective" excitation. Furthermore, despite the complexity of this problem, under rather typical conditions the dispersion relation takes a remarkably simple and regular form. Finally, we argue that under certain conditions the dispersion relation is determined via collective excitation. The corresponding many-body state, which, in addition to the interaction energy minimizes also the kinetic energy, is dictated by elementary number theory.

  • 1573.
    Routh, Joyanto
    et al.
    Örebro University, School of Science and Technology. Dept Earth Sci, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, India.
    Hjelmquist, Per
    Dept Geol & Geochem, Stockholm Univ, Stockholm, Sweden.
    Distribution of arsenic and its mobility in shallow aquifer sediments from Ambikanagar, West Bengal, India2011In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 26, no 4, p. 505-515Article in journal (Refereed)
    Abstract [en]

    Sediments from a core retrieved during installation of a shallow drinking water well in Ambikanagar (West Bengal, India) were analyzed for various physical and chemical parameters. The geochemical analyses included: (1) a 4-step sequential extraction scheme to determine the distribution of As between different fractions, (2) As speciation (As(3+) vs. As(5+)), and (3) C, N and S isotopes. The sediments have a low percentage of organic C and N (0.10-0.56% and 0.01-0.05%, respectively). Arsenic concentration is between 2 and 7 mg kg(-1), and it is mainly associated with the residual fraction, less susceptible to chemical weathering. The proportion of As(3+) in these sediments is high and ranges from 24% to 74%. Arsenic in the second fraction (reducible) correlates well with Mn, and in the residual fraction As correlates well with several transition elements. The stable isotope results indicate microbial oxidation of organic matter involving SO(4) reduction. Oxidation of primary sulfide minerals and release of As from reduction of Fe(oxy)hydroxides do not seem important mechanisms in As mobilization. Instead, the dominance of As(3+) and presence of As(5+) reducing microorganisms in this shallow aquifer imply As remobilization involving microbial processes that needs further investigations.

  • 1574.
    Rozpadek, Piotr
    et al.
    Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland; Institute of Plant Physiology, Polish Academy of Sciences, Kraków, Poland.
    Rapala-Kozik, Maria
    Department of Comparative Biochemistry and Bioanalytics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
    Wezowicz, Katarzyna
    Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland.
    Grandin, Anna
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Wazny, Rafal
    Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland.
    Anielska, Teresa
    Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland.
    Turnau, Katarzyna
    Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland; Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland.
    Arbuscular mycorrhiza improves yield and nutritional properties of onion (Allium cepa)2016In: Plant physiology and biochemistry (Paris), ISSN 0981-9428, E-ISSN 1873-2690, Vol. 107, p. 264-272Article in journal (Refereed)
    Abstract [en]

    Improving the nutritional value of commonly cultivated crops is one of the most pending problems for modern agriculture. In natural environments plants associate with a multitude of fungal microorganisms that improve plant fitness. The best described group are arbuscular mycorrhizal fungi (AMF). These fungi have been previously shown to improve the quality and yield of several common crops. In this study we tested the potential utilization of Rhizophagus irregularis in accelerating growth and increasing the content of important dietary phytochemicals in onion (Allium cepa). Our results clearly indicate that biomass production, the abundance of vitamin B1 and its analogs and organic acid concentration can be improved by inoculating the plant with AM fungi. We have shown that improved growth is accompanied with up-regulated electron transport in PSII and antioxidant enzyme activity.

  • 1575.
    Ruan, Ting
    et al.
    State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Lin, Yongfeng
    State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Wang, Thanh
    Örebro University, School of Science and Technology.
    Liu, Runzeng
    State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Jiang, Guibin
    State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Identification of novel polyfluorinated ether sulfonates as PFOS alternatives in municipal sewage sludge in China2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 11, p. 6519-6527Article in journal (Refereed)
    Abstract [en]

    A 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFAES) with the trade name F-53B, is an alternative to perfluorooctanesulfonate (PFOS) in electroplating industry that is uniquely used in China. It was developed as a mist suppressant initially in the 1970s, but the environmental behaviors and potential adverse effects of the 6:2 Cl-PFAES have only recently been investigated. In this work, the occurrence and distribution of perfluoroalkyl sulfonate (PFSA), fluorotelomer sulfonate (FTSA), and PFAES analogues were investigated in municipal sewage sludge samples collected around China. Perfluorobutane, perfluorohexane, perfluorooctane, and perfluorodecanesulfonates, 6:2 and 8:2 FTSAs, and the emerging 6:2 Cl-PFAES were detected. Moreover, 8:2 and 10:2 Cl-PFAESs were identified for the first time as new polyfluorinated contaminants using high resolution mass spectrometry. These fluorinated analytes were further quantified with the aid of commercial and laboratory-purified standards. PFOS was the predominant contaminant with a geometric mean (GM) value of 3.19 ng/g dry weight (d.w.), which was subsequently followed by 6:2 Cl-PFAES and 8:2 Cl-PFAES (GM: 2.15 and 0.50 ng/g d.w., respectively). Both 6:2 and 8:2 Cl-PFAES were positively detected as the major components in the F-53B commercial product, and discrete 6:2 Cl-PFAES/8:2 Cl-PFAES ratios in the product and sludge samples might suggest 8:2 Cl-PFAES had enhanced sorption behavior in the sludge due to the increase in hydrophobicity.

  • 1576.
    Rubinsson, Camilla
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Fredrik
    Örebro University, School of Science and Technology.
    S-Box, alright!: En introduktion av S-boxar som används vid DES- och AES-kryptering2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 1577.
    Rundblad, Emilia
    Örebro University, School of Science and Technology.
    Matematisk begåvning: Hur kan det mätas och vad karaktäriserar matematiskt begåvade elever?: En systematisk litteraturstudie för elever i lägre åldrar2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this paper, the concept of mathematical giftedness has been reviewed with the purpose of unraveling how mathematical giftedness amongst students can be measured, and also, what characterizes mathematical gifted students today. To answer those two questions, the main focus has been devoted to research carried out during the 21st century, including doctoral dissertations and peer-reviewed articles. By doing that, the result of this study will clarify how mathematical giftedness can be measured, and give an insight as to what characterize mathematical gifted students, all from a research perspective.

    My studies agree that the mathematical characteristics of the mathematically gifted students may differ from student to student, and may be what qualities what so ever that facilitates the teaching of mathematics to students. Most studies measuring mathematical talent with performance-based funding, which contradicts their own conclusions about all mathematically gifted students is their own character and both are learning and practicing knowledge in different ways.

  • 1578.
    Rundblad, Emilia
    Örebro University, School of Science and Technology.
    Skolors arbete med matematiskt begåvade elever: En intervjustudie med fokus på rektorer för grundskolans tidiga åldrar2015Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    According to the Education Act, school leaders should lead the educational activities. This study investigates how four school leaders working to promote mathematically gifted students. The study also investigates if those four schools are having a common strategy to identify mathematically gifted students and if there is a common strategy at each school to encourage the students toward further development using stimulating work methods. Principals also get to see an action for gifted students that SKL (Sveriges kommuner och landsting) has developed in cooperation with seven of Sweden's municipalities.

    What shows in the results and analysis is that none of the interviewed principals have a clear picture of how they identify mathematically gifted students. Three principals mentioned abilities and one principal talks about good grades. All four principals advocating the promotion of mathematically gifted students and has left the biggest responsibility for the teacher. It also shows in the study that the principals are unsure that the school is even able to live up to the promotion of gifted students and wishes for a more developed method of working with these students in the future. None of the four schools in the study have a common approach to how they identify mathematical talent and no united method for stimulating these students.

    However, schools do use the individual teacher, special education teachers, tests, math groups and level group, to identify and stimulate mathematically gifted students. The study also shows that shortcomings in educational leadership has often been due to many reasons, such as: lack of knowledge, time pressure and an economic aspect, something that the principals often don’t control by him or herself.

  • 1579.
    Russell, Mark H.
    et al.
    DuPont Haskell Global Centers for Health and Environmental Sciences, Newark DE, USA.
    Nilsson, Helena
    Örebro University, School of Science and Technology.
    Buck, Robert C.
    DuPont Chemicals and Fluoroproducts, Wilmington DE, USA.
    Elimination kinetics of perfluorohexanoic acid in humans and comparison with mouse, rat and monkey2013In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 93, no 10, p. 2419-2425Article in journal (Refereed)
    Abstract [en]

    Major fluorinated chemical manufacturers have developed new short-chain per- and polyfluorinated substances with more favorable environmental, health and safety profiles. This study provides the first evaluation of the elimination half-life of perfluorohexanoic acid (PFH)(A) from the blood of humans. PFHxA biomonitoring data were obtained from a recently published study of professional ski wax technicians. These data were analyzed to provide estimates of the apparent half-life of PFHxA from humans, and comparisons were made with kinetic studies of PFHxA elimination from mice, rats and monkeys. The apparent elimination half-life of PFHxA in highly exposed humans ranged between 14 and 49 d with a geomean of 32 d. The half-lives of PFHxA in mice, rats, monkeys and humans were proportional to body weight with no differences observed between genders, indicating similar volumes of distribution and similar elimination mechanisms among mammalian species. Compared to long-chain perfluoroalkyl acid analogs, PFHxA is rapidly cleared from biota. The consistent weight-normalized elimination half-lives for PFHxA in mammalian species indicates that results obtained from animal models are suitable for establishment of PFHxA benchmark dose and reference dose hazard endpoints for use in human risk assessments. (C) 2013 Elsevier Ltd. All rights reserved.

  • 1580.
    Rydell, Stefan
    et al.
    Örebro University, School of Science and Technology.
    Asotic, Emil
    Örebro University, School of Science and Technology.
    Effektivisering av arbetsflöde för artikeln Front plate2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out at Linde Maskiner AB in Lindesberg. The aim of this work was to streamline the workflow for one of Linde Maskiner major products, Front plate. You want to streamline the flow with regard to aspects such as reducing various forms of wastage and to review the quality assurance of the assembly process. Lean has been studied in depth, and is as a theoretical basis for the project. Lean is according to us the basis for the modernization of a traditional company. Thorough analysis has been done in form of time analysis, observations and ongoing conversations. These analyses have been made in the assembly station which is the central process in Front plates workflow. The analyzes show that the efficiency of front plates flow is feasible and suggestions for improvement have been developed along this.

  • 1581.
    Ryve, Andreas
    et al.
    Mälardalen University, Västerås, Sweden.
    Nilsson, Per
    Örebro University, School of Science and Technology.
    Palm, Torulf
    Umeå University, Umeå, Sweden.
    Van Steenbrugge, Hendrik
    Mälardalen University, Västerås, Sweden.
    Andersson, Catarina
    Umeå University, Umeå, Sweden.
    Bergwall, Andreas
    Örebro University, School of Science and Technology.
    Boström, Erika
    Umeå University, Umeå, Sweden.
    Larsson, Maria
    Mälardalen University, Västerås, Sweden.
    Vingsle, Lotta
    Umeå University, Umeå, Sweden.
    Kartläggning av forskning om formativ bedömning, klassrumsundervisning och läromedel i matematik: Delrapport från skolforsk-projektet2015Report (Other academic)
    Abstract [en]

    The current project focuses on mathematics education, and is partitioned into three subprojects mapping research on formative assessment, classroom teaching, and curriculum programs in mathematics. The rationale for focusing on these three areas is that they are all highly relevant for understanding and improving Swedish mathematics education and students’ knowing of mathematics. Therefore, the aim of the project is to map research on formative assessment, classroom teaching, and curriculum programs in mathematics education.

    The methodology of the literature review has been inspired by Gough, Oliver, and Thomas (2013), and we have focused on the mapping on journal articles published on Web of Science (WoS).

    The results from the sample of articles on formative assessment show that strategies of formative assessment in mathematics are positively correlated to students’ performance in mathematics with medium and large effect sizes. However, based on the current mapping it is difficult to specify aspects of how the formative strategies are to be implemented in order to promote students’ knowing of mathematics.

    Despite the change in perspective of what constitutes knowledge in mathematics to also include reasoning, problem-solving and communication, the map shows that research is mainly focused on examining teaching methods and their effects on students’ skills in mathematics. A closer examination of the studies that do focus on teaching for supporting students in developing competencies like reasoning and problem-solving shows that connections between and comparison of students’ solutions, as well as teachers’ ways of asking questions to support students in explaining their solutions clearly and in detail, are important for students’ learning of these competencies.

    A central finding stemming from this review of curriculum programs is the complexity involved in how the programs can support teachers in establishing classroom practices. Curriculum resources and teacher resources, as well as other influencing factors, impact the quality of instruction, and studies have begun to point out how curriculum resources and teacher resources uniquely and jointly impact classroom practices. Multiple research articles have expressed the need for teacher support in implementing curriculum programs, by means of professional development, teacher education and support provided by the curriculum programs themselves. Interesting in this regard is the state of the research field concerning the design of educative curriculum programs, and how teachers make use of such support. Studies have proposed design approaches, regarding both the actual development of educative curriculum programs as well as how to use them in teacher education to support prospective teachers’ development of knowledge. Further, although research has revealed that it is important to prepare for teaching in certain ways, we found very little research that explicitly analyzed how teachers actually prepare for teaching a mathematics lesson.

    Limitations of the project include: (1) the lack of searching in potentially relevant databases, (2) the fact that a relatively small proportion of articles found in the search have been coded, (3) that we have not engaged in deep considerations as to whether and in what ways results from international research are relevant in the Swedish context, and (4) that we therefore have not been able to synthesize the results of the study. In relation to the Swedish context (Hemmi & Ryve, 2014; Boesen et al., 2014), international research (Hattie, 2009; Smith & Stein, 2011), and the current project’s findings, we recommend that Skolforskningsinstitutet focus on two aspects of great importance for developing students’ knowing of mathematics. First, Skolforskningsinstitutet should synthesize research that supports actors, such as teachers and principals, in acting within school practices. In the case of teachers, support is needed to engage them in actively anticipating students’ thinking, using curriculum programs effectively, introducing mathematical content, acting in group work, formatively assessing students’ learning, and orchestrating whole-class mathematical discussions. Secondly, actors within school practices need support not only in initiating and implementing developments but also in institutionalizing such developments. Skolforskningsinstitutet should specify the kind of support needed in order to ensure that material, routines, competences, and organizations become integral and permanent features of Swedish school practice. 

  • 1582.
    Rönnberg, Ellen
    Örebro University, School of Science and Technology.
    Språkliga konflikter i matematikämnet: En kvalitativ studie om pedagogers uppfattningar kring arabiskatalande elevers språk- och matematikkunskaper2017Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    It is a study about pedagogue’s perception of the linguistic conflicts that Arabic speaking pupil expe-riences in the education of mathematics. It has been known that the Swedish language is a primal part of the education in math and therefor it becomes a problematic phenomenon. This difficulties appears because second language pupils have to show their mathematic knowledge and understanding in a foreign language.

    This purpose of this essay’s to examine and explain how pedagogues accommodate math education and how they experiences and work with math education and second language pupils. To examine the purpose of this study two qualitative interweaves has been done with two pedagogues who teaches Arabic speaking pupils (among others) in third grade.

    To examine and explain how these two pedagogues understands and experiences this phenomenon about math second languages pupils and math education has a phenomenological theory been used. The result of this study is represent in guidance with the previous science to analyze it’s outcome. This because to create lucidness in the text and to make it more readable.

    The conclusion that can been drawn from the result of this essay is that language developing work in mathematics education is an important and crucial part for second language pupils ability to success.

  • 1583.
    Rönnbäck, Sara
    et al.
    Örebro University, School of Science and Technology.
    Johansson, Anna
    Örebro University, School of Science and Technology.
    Bilburen laserskanning2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 1584.
    SAAD SHAIKH, MUHAMMAD
    Örebro University, School of Science and Technology.
    Quadrocopter Fuzzy Flight Controller2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Quadrocopter is an aerial vehicle platform which has become very popular

    among researchers in the recent past due to the advantages it offers over conventional

    helicopters. Quadrocopter is very simple and unique, but it is inherently

    unstable from aerodynamics point of view. In recent past researchers

    have proposed many control schemes for quadrocopter. In this thesis we present

    fuzzy logic controller for quadrocopter. After brief introduction brief hardware

    details are given that is used in this thesis. After that design procedure for the

    fuzzy controller is presented. Then the designed fuzzy controller is tested in

    Hardware In Loop (HIL) setup. The experimentation to validate the functionality

    and applicability of the designed controller were performed in contrained

    setup due to some technical problems. The results of the experiments were satisfactory

    and it is concluded that it is possible to stabilize quadrocopter with

    fuzzy logic controller.

  • 1585.
    Saarinen, Jari
    et al.
    Department of Automation and Systems Technology, Aalto University, Alto, Finland.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Lilienthal, Achim
    Örebro University, School of Science and Technology.
    Independent Markov Chain Occupancy Grid Maps for Representation of Dynamic Environments2012In: 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems, New York, USA: IEEE, 2012, p. 3489-3495Conference paper (Refereed)
    Abstract [en]

    In this paper we propose a new grid based approach to model a dynamic environment. Each grid cell is assumed to be an independent Markov chain (iMac) with two states. The state transition parameters are learned online and modeled as two Poisson processes. As a result, our representation not only encodes the expected occupancy of the cell, but also models the expected dynamics within the cell. The paper also presents a strategy based on recency weighting to learn the model parameters from observations that is able to deal with non-stationary cell dynamics. Moreover, an interpretation of the model parameters with discussion about the convergence rates of the cells is presented. The proposed model is experimentally validated using offline data recorded with a Laser Guided Vehicle (LGV) system running in production use.

  • 1586.
    Saarinen, Jari
    et al.
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Ala-Luhtala, Juha
    Aalto University of Technology, Aalto, Finland.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Normal distributions transform occupancy maps: application to large-scale online 3D mapping2013In: IEEE International Conference on Robotics and Automation, New York: IEEE conference proceedings, 2013, p. 2233-2238Conference paper (Refereed)
    Abstract [en]

    Autonomous vehicles operating in real-world industrial environments have to overcome numerous challenges, chief among which is the creation and maintenance of consistent 3D world models. This paper proposes to address the challenges of online real-world mapping by building upon previous work on compact spatial representation and formulating a novel 3D mapping approach — the Normal Distributions Transform Occupancy Map (NDT-OM). The presented algorithm enables accurate real-time 3D mapping in large-scale dynamic nvironments employing a recursive update strategy. In addition, the proposed approach can seamlessly provide maps at multiple resolutions allowing for fast utilization in high-level functions such as localization or path planning. Compared to previous approaches that use the NDT representation, the proposed NDT-OM formulates an exact and efficient recursive update formulation and models the full occupancy of the map.

  • 1587.
    Saarinen, Jari
    et al.
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    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.
    3D normal distributions transform occupancy maps: an efficient representation for mapping in dynamic environments2013In: The international journal of robotics research, ISSN 0278-3649, E-ISSN 1741-3176, Vol. 32, no 14, p. 1627-1644Article in journal (Refereed)
    Abstract [en]

    In order to enable long-term operation of autonomous vehicles in industrial environments numerous challenges need to be addressed. A basic requirement for many applications is the creation and maintenance of consistent 3D world models. This article proposes a novel 3D spatial representation for online real-world mapping, building upon two known representations: normal distributions transform (NDT) maps and occupancy grid maps. The proposed normal distributions transform occupancy map (NDT-OM) combines the advantages of both representations; compactness of NDT maps and robustness of occupancy maps. One key contribution in this article is that we formulate an exact recursive updates for NDT-OMs. We show that the recursive update equations provide natural support for multi-resolution maps. Next, we describe a modification of the recursive update equations that allows adaptation in dynamic environments. As a second key contribution we introduce NDT-OMs and formulate the occupancy update equations that allow to build consistent maps in dynamic environments. The update of the occupancy values are based on an efficient probabilistic sensor model that is specially formulated for NDT-OMs. In several experiments with a total of 17 hours of data from a milk factory we demonstrate that NDT-OMs enable real-time performance in large-scale, long-term industrial setups.

  • 1588.
    Saarinen, Jari
    et al.
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    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.
    Normal distributions transform monte-carlo localization (NDT-MCL)2013In: Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, 2013, p. 382-389Conference paper (Refereed)
  • 1589.
    Saarinen, Jari
    et al.
    Örebro University, School of Science and Technology.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Fast 3D mapping in highly dynamic environments using normal distributions transform occupancy maps2013In: Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, 2013, p. 4694-4701Conference paper (Refereed)
  • 1590.
    Saenz-Méndez, Patricia
    et al.
    Computational Chemistry and Biology Group, Facultad de Química, Universidad de la República (UdelaR), Montevideo, Uruguay.
    Elmabsout, Ali Ateia
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Clinical Medicine, School of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Sävenstrand, Helena
    Örebro University, School of Science and Technology.
    Awadalla, Mohamed Khalid Alhaj
    Department of Clinical Medicine, School of Health Sciences, Örebro University, Örebro, Sweden.
    Strid, Åke
    Örebro University, School of Science and Technology.
    Sirsjö, Allan
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Clinical Medicine, School of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Eriksson, Leif A.
    Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
    Homology models of human all-trans-retinoic acid metabolizing enzymes CYP26B1 and CYP26B1 spliced-variant2012In: Journal of Chemical Information and Modeling, ISSN 1549-9596, E-ISSN 1549-960X, Vol. 52, no 10, p. 2631-2637Article in journal (Refereed)
    Abstract [en]

    Homology models of CYP26B1 (cytochrome P450RAI2) and CYP26B1 spliced-variant were derived using the crystal structure of cyanobacterial CYP120A1 as template for the model building. The quality of the homology models generated were carefully evaluated, and the natural substrate all-trans-retinoic acid (atRA), several tetralone-derived retinoic acid metabolizing blocking agents (RAMBAs) and a well known potent inhibitor of CYP26B1 (R115866) were docked into the homology model of full-length cytochrome P450 26B1. The results show that in the model of the full length CYP26B1, the protein is capable of distinguishing between the natural substrate (atRA), R115866 and the tetralone derivatives. The spliced-variant of CYP26B1 model displays a reduced affinity for atRA compared to the full length enzyme, in accordance with recently described experimental information.

  • 1591.
    Saffiotti, Alessandro
    et al.
    Örebro University, School of Science and Technology.
    Broxvall, Mathias
    Örebro University, School of Science and Technology.
    Affordances in an ecology of physically embedded intelligent systems2008In: Towards affordance-based robot control, SPRINGER-VERLAG BERLIN, HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY , 2008, p. 106-121Conference paper (Refereed)
    Abstract [en]

    The concept of Ecology of Physically Embedded Intelligent Systems, or PFIS-Ecology, combines insights from the fields of autonomous robotics and ambient intelligence to provide a new solution to building intelligent robotic systems in the service of people. The concept of PEIS-Ecology also offers an interesting setting to study the applicability of Gibson's notion of affordances to an ecology of robots. In this paper we introduce this concept, and discuss its potential and implications both from an application point of view and from an ecological (Gibsonian) point of view. We also discuss some new scientific challenges introduced by a PEIS-Ecology, present our current steps toward its realization, and point at a few experimental results that show the viability of this concept.

  • 1592.
    Saffiotti, Alessandro
    et al.
    Örebro University, School of Science and Technology.
    van der Zant, Tijn
    CEO at RoboLect, CTO at SIM-CI, the Netherlands.
    The Impact of RoCKIn on Robotics2017In: RoCKIn: Benchmarking Through Robot Competitions / [ed] Pedro Lima, INTECH, 2017, p. 1-5Chapter in book (Refereed)
  • 1593.
    Safi, Roman
    et al.
    Örebro University, School of Science and Technology.
    Haidari, Josef
    Örebro University, School of Science and Technology.
    undersökning av eu:s 20/20/20- strategi samt örebro kommuns miljökrav (energikrav)2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    ABSTRACT

    An important research area in building physics is how effectively we can use the energy in

    the built environment. The EU and the Council of Ministers have decided and formed a

    strategy in which one of the main subjects is “Climate Change and Energy supply", which

    means that the effluent will be reduced and use of renewable energy with more efficiency

    will increase.

    In our thesis we investigate how Sweden's energy requirements in the future will match the

    EU and the Council of Ministers decision. An account is made for energy efficient

    buildings to show the efficiency of these and how they affect the society.

    In this thesis we also look on Örebro Township's environmental requirements and FEBY 's

    requirements levels, who are used when constructing residential and premises buildings on

    municipal land in Örebro. These energy requirements are much tougher than the regular

    Swedish construction regulations “Boverkets byggregler” (BBR ).

    We also investigated a number of houses which are related to "nearly zero-energy

    buildings" heated with district heating and heat-pumps. The result shows that the energy

    saving is relatively high compared to the current building regulations, and that the

    additional costs are not so high.

  • 1594.
    Sakil, Habib Abdullah Mohammad
    Örebro University, School of Science and Technology.
    The Role of TAp73 in Tumor Angiogenesis2013Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    The p73 gene encodes two major classes of proteins; transactivation domain containing p73

    (TAp73) isoforms that act as transcription factors and N-terminal truncated isoforms, ΔNp73,

    that act in a dominant negative manner. p73 belongs to the p53-family of proteins and Ap73 shares many hallmark features with the archetypical tumor suppressor p53. However, in contrast to p53, p73 is rarely mutated and its tumorigenic effect may be due to the alteration in balance between TAp73 and ΔNp73 isoforms. To better comprehend how p73-isoforms control tumorigenesis in vivo, we generated E1A/RasV12G transformed TAp73+/+ and TAp73-/- mouse embryonic fibroblasts (MEFs) that were injected subcutaneously into Nude mice. We observed that TAp73-/- E1A/RasV12G MEFs formed larger tumors with shorter latency compared to TAp73+/+ E1A/RasV12G MEFs. Investigation of angiogenesis by immunohistochemical staining for the endothelial marker CD31 showed increased blood vessel formation in TAp73-/- tumors, this was further evaluated by in vitro HUVEC migration assay. Angiogenesis array analysis for genes that regulate angiogenesis revealed up-egulation of several pro-angiogenic targets namely CXCL2, CXCL5, CCL2, CCL11, IL-1β, IL6 and matrix metalloproteinase MMP2 in TAp73-/-tumors compared to wild type (WT). qRT-PCR analysis validated up-regulation of the proangiogenic cytokine IL-1β and chemokine CCL2 on mRNA level in TAp73-/- tumors. Since CCL2 is a macrophage chemo-attractant, we analyzed macrophage infiltration immunohistochemically and observed increased infiltration in TAp73-/- tumors compared to WT; furthermore, the effect on macrophage migration was also assessed by in vitro chemotaxis assay. Our data verify that TAp73 is a tumor suppressor and loss of TAp73 promotes angiogenesis; genes controlling angiogenesis and macrophage migration are up-regulated in absence of TAp73.

  • 1595.
    Salahaldin, Mohamad
    Örebro University, School of Science and Technology.
    Molecular Detection of Antibiotic Resistance Genes in Sludge from Wastewater Treatment2013Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Bacterial antibiotic resistance is an increasing global health problem, leaving few therapeutic options available for the treatment of pathogenic infections. The development of new antibiotics has been slow since their discovery more than 8 decades, therefore, monitoring the extent and distribution of antibiotic resistance is of great importance. The aim of this study was to determine the presence of antibiotic resistance genes in sludge samples obtained from three wastewater treatment plants (WWTPs) in Sweden. Samples were collected and analyzed for the presence of nalidixic acid (NA), chloramphenicol (CHL), and tetracycline (TC) resistance genes using polymerase chain reaction (PCR). The DNA extracted from Eskilstuna and MälarEnergi sludge showed the presence of NA and TC resistance genes, whereas Örebro sludge was found to have resistance for TC antibiotic genes. To validate the results, PCR detection for resistance genes was performed on Escherichia coli isolates from the sludge samples. Antibiotic susceptibility testing was used to confirm the genetic analysis for antibiotic resistance genes detection in these E. coli. The PCR results for TC resistance genes correlated between sludge PCR analysis and bacterial isolates for all 3 WWTPs. Based on the results obtained from the genotypic analysis of sludge and E coli, incomplete compatibility in regards to NA, and CHL were observed. However on the basis of antibiotic susceptibility testing, E coli isolates from MälarEnergi sludge samples unveiled the majority presence for antibiotic resistance genes. The results suggest that extra monitoring for the wastewater treatment facilities are vital to minimize the rising incidence of antibiotic resistant bacteria.

  • 1596.
    Salam, Noor
    Örebro University, School of Science and Technology.
    Role of Selective Estrogen Receptors B Agonist on Chronic Lymphocytic Leukemia Growth in Vitro2014Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    The estrogen receptor alpha (ERa) and estrogen receptor beta (ER~) have been demonstrated to be important for immune system regulation and studies have suggested an antiproliferative effect of ER~ in lymphoid malignancies. We have studied the expression of ERa and ER~ in peripheral blood mononuclear cells from patients with chronic lymphocytic leukemia (CLL). Expression of ERa was low, while ER~ was highly expressed in CLL cells. In order to investigate the possible inhibitory effect of ligand-activated ER~ , we treated CLL cells and Mecl cell lines with the selective ER~ agonist diarypropionitrile (DPN) in culture. Treating Mecl cell lines with DPN showed an antiproliferative effect of ER~ agonist by significantly inhibit the growth of Mec 1 cell lines. This suggests that ER~ agonist may be useful in the treatment of CLL.

  • 1597.
    Salihovic, Samira
    Örebro University, School of Science and Technology.
    Development and application of high-throughput methods for analysis of persistent organic pollutants in human blood2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The general public is continuously exposed to a wide range of environmental pollutants. This thesis focuses on a group of anthropogenic chemicals referred to as persistent organic pollutants (POPs) that have been linked to various adverse health effects in humans.

    The main objective of this thesis was focused on the development and application of high-throughput methods for analysis of a broad range of chlorinated, brominated, and fluorinated POPs in human blood.

    After establishing that the methods were effective, the two methods were applied to human plasma samples to examine the background levels of a broad range of POPs in human plasma samples among elderly men and women from Sweden and to assess the influence of gender. Levels of a wide range of chlorinated, brominated, and fluorinated compounds were determined in plasma samples collected during 2001-2004 from 1, 016 (50.2% women) 70 year-old participants from the population-based Prospective Study of the Vasculature in Uppsala Seniors (PIVUS). The POPs studied were 16 polychlorinated biphenyls (PCBs), 5 organochlorine pesticides (OCPs), 1 dioxin, 1 brominated flame retardant as well as 14 perfluoroalkyl substances (PFAS) including structural perfluorooctane sulfonic acid (PFOS) isomers. The majority of the studied compounds were detected in the 70-100% of the participants. The structural PFOS isomers were successfully quantified in a sub-sample of 25 men and women. Furthermore, gender differences in the concentrations of the POPs studied showed that the majority of chlorinated and brominated compounds were significantly different when comparing men and women in the study, while the concentrations of the fluorinated compounds were found to be less influenced by gender.

    This thesis has, by using the developed high-throughput methods requiring only small amounts of human blood, provided background exposure information of a broad range of POPs for an epidemiological study.

    List of papers
    1. Trends in the analysis of persistent organic pollutants (POPs) in human blood
    Open this publication in new window or tab >>Trends in the analysis of persistent organic pollutants (POPs) in human blood
    2013 (English)In: TrAC. Trends in analytical chemistry, ISSN 0165-9936, E-ISSN 1879-3142, Vol. 46, p. 129-138Article in journal (Refereed) Published
    Abstract [en]

    The general demands on analytical practices in laboratories involved in monitoring concentrations of persistent organic pollutants (POPs) in human blood in the context of the Stockholm Convention are met by the validated analytical procedures applied in most laboratories today. At the same time, as the concentrations of many of the legacy POPs are decreasing in the general populations, more specific, sensitive, and accurate analytical techniques are required. Thus, a challenge for the Stockholm Convention is the analytical capacity, in terms of quality and availability worldwide, to monitor declining concentrations of POPs in human blood. However, other POP issues (e.g., those targeted by epidemiological studies) might require different information and therefore more specialized analytical procedures having greater instrumental sensitivity.

    We review current and emerging analytical procedures used for analysis of the chlorinated, brominated, and fluorinated classes of POPs in human blood with a focus on the compounds included in the Stockholm Convention. In general, analytical trends in sample clean-up, separation, detection techniques and quality protocols provide a tool for POP laboratories to measure POPs in human blood. Techniques based on established mass-selective instruments are most commonly employed but declining concentrations in humans in the future might require more selective, more sensitive techniques.

    Place, publisher, year, edition, pages
    Oxon, UK: Elsevier, 2013
    Keywords
    Gas chromatography (GC), High-resolution mass spectrometry (HRMS), Human blood, Liquid chromatography (LC), Organochlorine (OC) pesticide, Perfluoroalkylated substance (PFAS), Polychlorinated biphenyl (PCB), Polychlorinated dibenzo-p-dioxin (PCDD), Polychlorinated diphenyl ether (PBDE), Stockholm Convention
    National Category
    Chemical Sciences Analytical Chemistry
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-29858 (URN)10.1016/j.trac.2012.06.009 (DOI)000319087800027 ()2-s2.0-84876816513 (Scopus ID)
    Available from: 2013-06-28 Created: 2013-06-28 Last updated: 2017-12-06Bibliographically approved
    2. A rapid method for screening of the Stockholm Convention POPs in small amounts of human plasma using SPE and HRGC/HRMS
    Open this publication in new window or tab >>A rapid method for screening of the Stockholm Convention POPs in small amounts of human plasma using SPE and HRGC/HRMS
    Show others...
    2012 (English)In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 86, no 7, p. 747-753Article in journal (Refereed) Published
    Abstract [en]

    A rapid analytical screening method allowing simultaneous analysis of 23 persistent organic pollutants (POPs) in human plasma was developed. Sample preparation based on solid-phase extraction (SPE) with additional clean-up using small multilayer silica gel columns. SPE was performed using a custom made polystyrene-divinylbenzene sorbent for the extraction of chlorinated and brominated POPs. Special efforts to reduce sample volume and improve speed and efficiency of the analytical procedure were made. Determination of 16 polychlorinated biphenyls (PCBs), 5 organochlorine (OC) pesticides, octachlorinated dibenzo-p-dioxin (OCDD) and polybrominated diphenyl ether (BDE #47) in 0.5 mL human plasma was performed by using high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). Recovery of POPs ranged between 46% and 110%, and reproducibility was below 25% relative standard deviation (RSD) for all target compounds, except for trans-nonachlor and OCDD, which were present only at low levels. Limits of detection (LOD) were for the PCBs between 0.8 and 117.7 pg mL(-1) plasma and for the OC pesticides between 5.9 and 89.1 pg mL(-1) plasma. The LOD for OCDD and BDE #47 were 1.4 pg mL(-1) plasma, and 9.2 pg mL(-1) plasma, respectively. The presented method was successfully applied to 1016 human plasma samples from an epidemiological study on cardiovascular disease. (C) 2011 Elsevier Ltd. All rights reserved.

    Place, publisher, year, edition, pages
    Elsevier, 2012
    Keywords
    Persistent organic pollutants, Sample extraction, Human plasma, HRGC/HRMS, Polychlorinated biphenyls, Organochlorine pesticides
    National Category
    Chemical Sciences
    Research subject
    Environmental Chemistry
    Identifiers
    urn:nbn:se:oru:diva-22315 (URN)10.1016/j.chemosphere.2011.11.006 (DOI)000301166700008 ()22153485 (PubMedID)2-s2.0-84856031844 (Scopus ID)
    Available from: 2012-04-02 Created: 2012-04-02 Last updated: 2017-12-07Bibliographically approved
    3. A rapid method for analysis of PFAS including structural PFOS isomers in human serum using 96-well plate column-switching UPLC-S/MS
    Open this publication in new window or tab >>A rapid method for analysis of PFAS including structural PFOS isomers in human serum using 96-well plate column-switching UPLC-S/MS
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    To facilitate high-throughput analysis suitable for large epidemiological studies we developed an automated column-switching ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determination of perfluorocarboxylates (PFCAs; C5, C6, C7, C8, C9, C10, C11, C12, and C13), perfluoroalkyl sulfonic acids (PFSAs; C4, C6, C8, and C10), perfluorooctane sulfonamide (PFOSA), and five groups of structural perfluorooctane sulfonic acids (PFOS) isomers in human serum or plasma. The analytical procedure involves rapid protein precipitation using 96-well plates followed by a fully automated sample clean-up using an on-line trap column removing many potentially interfering sample components while through the mobile phase gradient the target analytes are eluted onto the analytical column for further separation and subsequent mass detection. The method showed good linearity (R2 < 0.995) at concentrations ranging from 0.01 to 60 ngmL-1 and low method detection limits (MDLs) ranging between 0.01-0.17 ngmL-1 depending on the analyte. The precision of the developed method was good, with within-run (n=7) and between-run (n=103) coefficients of variation between 2% and 20% for most compounds including PFOS (2%, 8%) and its structural isomers (2-6% and 4-8%). The method showed good conformity with a standard reference material (n=56). The columnswitching UPLC method has been successfully applied for the determination of perflourinated alkyl acids (PFAAs), including structural PFOS isomers, and PFOSA in human plasma from an epidemiological study.

    Keywords
    human blood, perfluoroalkylated substances, structural isomers, perfluorooctane sulfonamide, sample preparation, column-switch, pfos, pfoa
    National Category
    Chemical Sciences
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-30109 (URN)
    Available from: 2013-08-02 Created: 2013-08-02 Last updated: 2017-10-17Bibliographically approved
    4. Circulating levels of Persistent Organic Pollutants (POPs) among elderly men and women from Sweden: results from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS)
    Open this publication in new window or tab >>Circulating levels of Persistent Organic Pollutants (POPs) among elderly men and women from Sweden: results from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS)
    Show others...
    2012 (English)In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 44, p. 59-67Article in journal (Refereed) Published
    Abstract [en]

    Persistent Organic Pollutants (POPs) are a huge group of chemicals that have been linked to various adverse health effects in humans. Large epidemiological studies investigating gender differences in levels of POPs in the elderly are limited and the results from these are not always consistent. The present study was undertaken to examine the background levels of a broad range of POPs in human plasma samples among elderly men and women from Sweden and to assess the influence of gender. Levels of 23 POPs were determined in plasma samples collected during 2001-2004 from 1016 (50.2% women) 70year-old participants from the population-based Prospective Study of the Vasculature in Uppsala Seniors (PIVUS). Measurements were performed using high resolution gas chromatography with high resolution mass spectrometry (HRGC-HRMS) and the POPs studied were 16 polychlorinated biphenyls (PCBs), five organochlorine (OC) pesticides, one dioxin, and one brominated flame retardant. The concentrations of the selected POPs were found similar, or comparable, to other studies of non-occupationally exposed populations from Sweden and Europe. Differences in levels of POPs between men and women were assessed by using Wilcoxon rank-sum (Mann-Whitney) test. Significant (p<0.0001) gender differences in levels of specific POPs were observed and a number of POP concentrations were found to differ between men and women. More specifically, levels of HCB, OCDD, and PCB congeners #74, #105, and #118 were found to be higher in women, while the rest of the majority of POPs were higher in men.

    National Category
    Natural Sciences Chemical Sciences
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-23923 (URN)10.1016/j.envint.2012.01.011 (DOI)000304745900008 ()
    Available from: 2012-07-05 Created: 2012-07-05 Last updated: 2017-12-07Bibliographically approved
  • 1598.
    Salihovic, Samira
    et al.
    Örebro University, School of Science and Technology. Department of Medical Sciences and Science for Life Laboratory, Molecular Epidemiology Unit, Uppsala University, Uppsala, Sweden.
    Fall, Tove
    Department of Medical Sciences and Science for Life Laboratory, Molecular Epidemiology Unit, Uppsala University, Uppsala, Sweden.
    Ganna, Andrea
    Massachusetts General Hospital, Harvard Medical School and Broad Institute, Boston, MA, USA.
    Broeckling, Corey D.
    Proteomics and Metabolomics Facility, Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.
    Prenni, Jessica E.
    Proteomics and Metabolomics Facility, Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.
    Hyötyläinen, Tuulia
    Örebro University, School of Science and Technology.
    Kärrman, Anna
    Örebro University, School of Science and Technology.
    Lind, P. Monica
    Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University, Uppsala, Sweden.
    Ingelsson, Erik
    Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA.
    Lind, Lars
    Department of Medical Sciences, Cardiovascular Epidemiology, Uppsala University, Uppsala, Sweden.
    Identification of metabolic profiles associated with human exposure to perfluoroalkyl substances2018In: Journal of Exposure Science and Environmental Epidemiology, ISSN 1559-0631, E-ISSN 1559-064XArticle in journal (Refereed)
    Abstract [en]

    Recent epidemiological studies suggest that human exposure to perfluoroalkyl substances (PFASs) may be associated with type 2 diabetes and other metabolic phenotypes. To gain further insights regarding PFASs exposure in humans, we here aimed to characterize the associations between different PFASs and the metabolome. In this cross-sectional study, we investigated 965 individuals from Sweden (all aged 70 years, 50% women) sampled in 2001-2004. PFASs were analyzed in plasma using isotope-dilution ultra-pressure liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). Non-target metabolomics profiling was performed in plasma using UPLC coupled to time-of-flight mass spectrometry (UPLC-QTOFMS) operated in positive electrospray mode. Multivariate linear regression analysis was used to investigate associations between circulating levels of PFASs and metabolites. In total, 15 metabolites, predominantly from lipid pathways, were associated with levels of PFASs following adjustment for sex, smoking, exercise habits, education, energy, and alcohol intake, after correction for multiple testing. Perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUnDA) were strongly associated with multiple glycerophosphocholines and fatty acids including docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). We also found that the different PFASs evaluated were associated with distinctive metabolic profiles, suggesting potentially different biochemical pathways in humans.

  • 1599.
    Salihovic, Samira
    et al.
    Örebro University, School of Science and Technology. Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
    Ganna, Andrea
    Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, USA; Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge Center, Cambridge, USA.
    Fall, Tove
    Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
    Broeckling, Corey D.
    Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, USA.
    Prenni, Jessica E.
    Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, USA.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Lind, P. Monica
    Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University Hospital, Uppsala, Sweden.
    Ingelsson, Erik
    Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden; Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, USA.
    Lind, Lars
    Department of Medical Sciences, Cardiovascular Epidemiology, Uppsala University, Uppsala, Sweden.
    The metabolic fingerprint of p,p'-DDE and HCB exposure in humans2016In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 88, p. 60-66Article in journal (Refereed)
    Abstract [en]

    Background: Dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB) are organochlorine pesticides with well-known endocrine disrupting properties. Exposure to p,p'-DDE and HCB concerns human populations worldwide and has been linked to metabolic disorders such as obesity and type 2 diabetes, but details about these associations in humans from the general population are largely unknown.

    Objectives: We investigated the associations between p,p'-DDE and HCB exposure and global metabolomic profiles in serum samples from 1016 participants from the Swedish population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study.

    Methods: HCB and p,p'-DDE levels were determined using gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS). Metabolite levels were determined by using a non-targeted metabolomics approach with ultra-performance liquid chromatography coupled to time-of- flight mass spectrometry (UPLC-TOFMS). Association analyses were performed using multivariate linear regression.

    Results: We found circulating levels of p,p-DDE and HCB to be significantly associated with circulating levels of 16 metabolites following adjustment for age, sex, education level, exercise habits, smoking, energy intake, and alcohol intake. The majority of the 16 metabolites belong to lipid metabolism pathways and include fatty acids, glycerophospholipids, sphingolipids, and glycerolipids. Overall, p,p'-DDE and HCB levels were found to be correlated to different metabolites, which suggests that different metabolic fingerprints may be related to circulating levels of these two pesticides.

    Conclusions: Our findings establish a link between human exposure to organochlorine pesticides and metabolites of key metabolic processes mainly related to human lipid metabolism.

  • 1600.
    Salihovic, Samira
    et al.
    Örebro University, School of Science and Technology. Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
    Kärrman, Anna
    Örebro University, School of Science and Technology.
    Lind, Lars
    Department of Medical Sciences, Cardiovascular Epidemiology, Uppsala University Hospital, Uppsala, Sweden.
    Lind, P. Monica
    Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University Hospital, Uppsala, Sweden.
    Lindström, Gunilla
    Örebro University, School of Science and Technology.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Perfluoroalkyl substances (PFAS) including structural PFOS isomers in plasma from elderly men and women from Sweden: Results from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS)2015In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 82, no Sept 2015, p. 21-27Article in journal (Refereed)
    Abstract [en]

    Per- and polyfluoroalkyl substances (PFASs) are a class of compounds with unique chemical properties that have been shown useful in a wide variety of applications because they provide materials with reduced surface tension and exceptional non-stick properties. PFASs are commonly found in impregnation materials, coatings of papers and textiles, fire-fighting foams, pesticides, and cleaning agents. The potential for human exposure to PFASs is high because of their widespread distribution. The aim of this study was to investigate levels of PFASs in men and women from Sweden and to assess the influence of gender and parity among women. Levels of 13 PFASs were determined in plasma samples collected during 2001–2004 from 1016 (507 women) 70 year-old participants from the population-based Prospective Study of the Vasculature in Uppsala Seniors (PIVUS). The PFASs studied were nine perfluorinated carboxylic acids (PFCAs), four perfluorinated sulfonic acids (PFSAs) and perfluorooctane sulfonamide (PFOSA). In addition, structural isomers of perfluorooctane sulfonic acid (PFOS) were determined in a subset of 398 individuals. The detection rates were high and the majority of the studied compounds were detected in more than 75% of the participants. Levels of the selected analytes were found to be similar to other studies of non-occupationally exposed populations. Gender differences were observed in levels of PFHpA which was higher in men, while PFHxS was higher in women. Parity among women was shown to have a minor effect on PFAS concentrations and we found primi- and multiparous women to have slightly lower levels of PFUnDA when compared to nulliparous women.

29303132333435 1551 - 1600 of 1981
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