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  • 301.
    Larsson, Anders
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Androgen receptors and endocrine disrupting substances2010Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Throughout the animal kingdom, organisms are dependent on substances such as steroid hormones to help them maintain internal balances. Examples of important tasks that are under regulation of steroid hormones are somatic and gonadal development, sexual performance and behavior (both social and sexual) as well as sex differentiation. Balance in the biology of reproduction is important for all organisms, and is sensitive to alterations and disturbances. If the environment is altered in a manner that lead to higher estrogenic or androgenic levels, the sex ratio of organisms that do not rely on genetic differences in the sex differentiation, will be biased towards more females or males in the population. It has been known for some time that there are pollutants in the environment that affect steroid pathways, such as the estrogenic and thyroid systems, but not much has been known about the androgenic systems. Examples of populations being masculinized have been recorded, and estrogenic compounds have been known to act as antiandrogens, but not until recently the first androgen agonist was identified. We used a combination of in vitro and computational modeling to identify the brominated flame retardant, 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane, as a potent androgen agonist to the human androgen receptor.

    In addition to this we cloned and characterized the androgen receptor from, a frequently used model organism, zebrafish (Danio rerio) as a receptor primarily activated by 11-ketotestosterone. This is a feature the zebrafish share with several other teleost fishes, such as the three-spined stickleback. Thus fish androgen receptors differ from most mammalian androgen receptors, where dihydrotestosterone is the most potent activator.

     

  • 302.
    Larsson, Bengt
    et al.
    Högskolan i Halmstad, Byggteknik.
    Sundqvist, Jan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Emmitt, Stephen
    Department of Civil Engineering,Technical University of Denmark.
    Component manufacturers’ perceptions of managing innovation2006Inngår i: Building Research & Information, ISSN 0961-3218, E-ISSN 1466-4321, Vol. 34, nr 6, s. 552-564Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this research is to understand component manufacturers' perception of their role in the innovation process. The role of the component manufacturer is different to other construction sector actors because they are product- not project-orientated. Base information was taken from part of a large benchmarking study conducted in Sweden. This helped to identify a small number of established component manufacturers located in a large geographical area of Sweden suitable for further investigation. Information about ten manufacturers was collected and interviews were conducted with their managing directors. The interviews revealed considerable variation in the manufacturers' perception of their position in the innovation process, their approach to new product development and interaction with their customers. Manufacturers were then graded according to their benchmarking and innovation procedures, which helped to illustrate a link between communication and information-sharing practices, benchmarking and innovation. The main findings are that the more innovative companies use information and benchmarking activities to their benefit. The more innovative companies have established a balance between innovations in process and product, have a clear direction from their managing director, and engage in regular communication with their customers.

  • 303.
    Larsson, Isak
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Webportal2011Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The project was done to the company Devexus AB. The task was to create a web portal to manage users in Active Directory (AD) through Frontline Identity Manager (FIM).

    The web site is written in C# and asp.net. It connects to the web service which is an addition to FIM. The portal can list, edit and save data. The web service handles password change via Windows Management Instrumentation (WMI).

    The portal also contains code to quickly modify what is presented to the people (users) which are administered. This is done using XML files. Data is presented using GridView and a class in order to modify its appearance.

  • 304.
    Larsson, Isak
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Webportal2011Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The project was done to the company Devexus AB. The task was to create a web portal to manage users in Active Directory (AD) through Frontline Identity Manager (FIM).

    The web site is written in C# and asp.net. It connects to the web service which is an addition to FIM. The portal can list, edit and save data. The web service handles password change via Windows Management Instrumentation (WMI).

    The portal also contains code to quickly modify what is presented to the people (users) which are administered. This is done using XML files. Data is presented using GridView and a class in order to modify its appearance.

  • 305.
    Larsson, Joakim
    Örebro universitet, Akademin för naturvetenskap och teknik.
    ANALYS AV TRÅDDRAGNINGSPROCESSEN2011Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Rapporten handlar om analys av tråddragningsprocessen och är inriktad på de temperaturer som uppstår under dragning.

    Tråddragning är en kallbearbetningsmetod men det uppstår höga temperaturer ända, dessa är inte alltid önskvärda.

    Analysen utförs för att senare kunna göra förbättringar för att kunna öka draghastigheten utan att temperaturen ökar. Detta är önskvart då tidigare studier visar att energin som åtgar vid dragningen minskar vid högre hastighet.

    Analysen utförs genom simuleringar av dragskivor under dragning, för att få värden att verifiera simuleringarna med gjordes ett industriforsök. Simuleringarna utförs med hjälp av den finita element metoden, FEM. Programmet som simuleringarna utförs i är Marc Mentat 2010.

    Även andra resultat ifrån industriförsöket analyseras och diskuteras.

  • 306.
    Larsson, Joakim
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Jarl, Magnus
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Teknik för högre draghastigheter: tempearturens inverkan2011Inngår i: Nordisk trådteknisk förening: årsmötesbok, Hallstahammar: Nordisk trådteknisk förening (NTTF) , 2011, s. 53-60Konferansepaper (Annet vitenskapelig)
    Abstract [sv]

    Temperaturer i tråddragningsprocessen har studerats vid ett industriförsök i Hjulbro. Temperaturer har mätts på nibs, tråd på block och kylvatten. Simuleringar har utförts med finita element metoden, FEM. Programmet som simuleringarna utförs i är Marc Mentat 2010.

  • 307.
    Larsson, Johan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Unmanned operation of load-haul-dump vehicles in mining environments2011Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Underground mines typically do not represent the best working conditions for humans, and many mining companies have the intent to remove all humans from the ore extraction areas. To achieve this goal automation of the mining machinery is required. One of the riskier jobs in a mine is to operate the Load-Haul-Dump (LHD) vehicles that are used to transport the ore from the blast site to a truck, lorry or directly to a crusher. Today these vehicles are typically controlled by an on-board manual operator. The purpose of the work presented in this thesis is to develop and evaluate algorithms and methods to enable high productivity unmanned operation of LHDs, including two different operating modes.

    The first mode is fully autonomous navigation, applicable to static environments, where the LHDs are repeatedly driven along the same paths for extended periods. Here, an existing framework for reactive navigation based on fuzzy logic has been extended with novel feature detection algorithms for tunnel following and topological localisation based on 2D laser range scanner data. These algorithms have been verified in quantitative tests to be fast, reliable and tolerant to noise in the sensor data. Moreover, the whole navigation system has been evaluated in qualitative tests in indoor environments using an ordinary research robot. The autonomous navigation system for LHDs currently commercialized by Atlas Copco is partly based on the experiences gained from the work presented here.

    The second mode explored is semi-autonomous operation, where local-autonomy functionality on-board the machine assists a tele-remote operator in driving the vehicle along a collision-free path. This mode is intended for mines where the driving path of the machine changes frequently, so the setup needed for a fully autonomous system becomes impractical. In this part of the work a user study in a real mine has been performed, showing that local autonomy has the potential to significantly improve the productivity of a tele-remote operated LHD. Based on these results, a commercial tele-operating system for underground mines has been extended with a novel local autonomy functionality, inspired by existing autonomous navigation systems. The performance of this system has been verified in experiments performed on a real 38 tonnes LHD in a test mine, and in simulations aimed to show that the system works in arbitrary underground mine environments.

  • 308.
    Larsson, Johan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Appelgren, Jörgen
    Atlas Copco Rock Drills AB, Örebro, Sweden.
    Marshall, Joshua
    Carleton University, Ottawa ON, Canada; (previously with) MDA Inc., Brampton ON, Canada.
    Next generation system for unmanned LHD operation in underground mines2010Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    In the pursuit of increased safety the mining industry has worked to develop systems for remote control and autonomous operation of both stationary and mobile equipment. This paper reports on a newly developed system for teleoperation and autonomous tramming of LHD (Load-Haul-Dump) mining vehicles that not only increases the safety of the operators, but also has the potential to increase productivity.

  • 309.
    Larsson, Johan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Appelgren, Jörgen
    Marshall, Joshua
    Barfoot, Timothy
    Atlas Copco infrastructureless guidance system for high-speed autonomous underground tramming2008Inngår i: Proceedings of the 5th International Conference and Exhibition on Mass Mining, Luleå, Sweden, June 2008, 2008, s. 585-594Konferansepaper (Fagfellevurdert)
    Abstract [en]

    During the last decade, mining companies and mobile equipment manufacturers have pursued improved efficiency, productivity, and safety in underground mining operations by automating some of the functions of underground vehicles. This paper describes the implementation and successful field testing of a new infrastructureless guidance system for autonomous tramming of centre-articulated underground mining vehicles (e.g., load-haul-dump and mine trucks). The project described in this paper is the result of a technical partnership between MDA, an experienced mining high-tech provider, and Atlas Copco, a world leader in the design of underground mining equipment.

  • 310.
    Larsson, Johan
    et al.
    AASS, Örebro University, Örebro, Sweden.
    Broxvall, Mathias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Akademin för naturvetenskap och teknik.
    An evaluation of local autonomy applied to teleoperated vehicles in underground mines2010Inngår i: 2010 IEEE International Conference on Robotics and Automation (ICRA), IEEE conference proceedings, 2010, s. 1745-1752Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Autonomous vehicles are being increasingly introduced in the mining industry. While these may offer high safety and high productivity, fully autonomous solutions are not always applicable or economically viable. Teleoperation is an attractive option, since it increases safety and comfort of the drivers. Unfortunately, the difficulty to operate the vehicle remotely often results in reduced productivity. In this paper, we show that techniques from the field of mobile robotics can be used to mitigate this problem. We extend a commercial teleoperation system for use in underground mines with a local autonomy functionality, with the main purpose to evaluate if the achieved productivity improvement motivates development of general algorithms and a fully commercial implementation. We then describe a user study performed in an underground mine with a 38 tonne articulated wheel loader, which proves that local autonomy gives a significant improvement in productivity of the teleoperation system, while retaining or even reducing the maintenance costs.

  • 311.
    Larsson, Johan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Broxvall, Mathias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Flexible infrastructure free navigation for vehicles in underground mines2008Inngår i: 4th international IEEE conference intelligent systems, IS '08, New York: IEEE , 2008, s. 2-45-2-50Konferansepaper (Fagfellevurdert)
    Abstract [en]

    During the last decade, mining companies and mobile equipment manufacturers have pursued improved efficiency, productivity, and safety in underground mining operations by automating some of the functions of underground vehicles. The work presented in this paper is the result of an effort to develop new flexible infrastructureless guidance system for autonomous tramming of center-articulated underground mining vehicles.

  • 312.
    Larsson, Johan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Broxvall, Mathias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Laser based intersection detection for reactive navigation in an underground mine2008Inngår i: IEEE/RSJ international conference on intelligent robots and systems, 2008, IROS 2008, 2008, s. 2222-2227Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we propose a new feature detection algorithm to enable junction recognition intended for high speed reactive navigation in tunnel like environments. We also present an extensive experimental evaluation of the algorithm based on data recorded in a real mine. The algorithm is faster and has less environmental constraints than similar algorithms that can be found in the litterature.

  • 313.
    Larsson, Johan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Broxvall, Mathias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Laser-based corridor detection for reactive navigation2008Inngår i: Industrial robot, ISSN 0143-991X, E-ISSN 1758-5791, Vol. 35, nr 1, s. 69-79Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For mobile robots operating in real-world environments, reactive navigation is a useful complement (or even replacement) to pure plan-based metric navigation. Reactive navigation is performed with respect to local perceived features, rather than a global metric reference frame, and can provide reduced installation costs, increased flexibility, and robustness to changes in the environment. To be effective, however, reactive navigation requires fast and reliable perception of the relevant features in the environment. Corridor-like structures are one of the most common features that are used for this purpose. In this paper, we propose a new method for corridor detection from laser data, based on the Hough transform, which is fast, reliable, and noise tolerant. We describe the algorithm, report an extensive experimental evaluation of its performance, and motivate the research with a real application involving the autonomous operation of a loader vehicle in an underground mine.

  • 314.
    Larsson, Johan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Broxvall, Mathias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Local autonomy for tele-operated vehiclesManuskript (preprint) (Annet vitenskapelig)
  • 315.
    Larsson, Johannes
    Örebro universitet, Akademin för naturvetenskap och teknik.
    AUTOMATLÅSANDE REPBROMS FÖR BERGSKLÄTTRING2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Repbromsen är en viktig del i klätterutrustningen och används av alla som klättrari berg. Många olika bromsar finns på marknaden, manuella och automatlåsande. yftet med projektet är att utveckla en produkt som kombinerar fördelarna med enenkel manuell broms med fördelarna hos en automatlåsande broms samtidigt som rodukten har användarvänlighet och säkerhet i fokus. Kraven på produkten ärbland annat låg vikt och en låsfunktion helt utan rörliga komponenter. Rapporten år igenom alla steg från idé till färdigt koncept. En förstudie har inlett projektet ed en marknadsundersökning som besvarats av aktiva klättrare. Utifrån undersökningen har en kravprofil fastsällts med krav och önskningar för produkten. Fem koncept arbetades fram som styrde vägen till en lösning där två av koncepten kombineras. Rapporten beskriver optimering av konceptet, materialvalsprocessen och dimensioneringen samt val av tillverkningsmetod.

    Genom rapporten bockas punkt efter punkt av från kravprofilen och resultatet är en automatlåsande repbroms helt utan rörliga komponenter i låsfunktionen. Rapporten innehåller många tydliga bilder för att förklara användning och funktion. Bromsen väger ungefär hälften av dagens mest populära automatlåsande broms och har ett bredare användningsområde.

  • 316.
    Larsson, Maria
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Hagberg, Jessika
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Rotander, Anna
    Örebro universitet, Akademin för naturvetenskap och teknik.
    van Bavel, Bert
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Engwall, Magnus
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Chemical and bioanalytical characterisation of PAHs in risk assessment of remediated PAH-contaminated soils2013Inngår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 20, nr 12, s. 8511-8520Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in soil at former industrial areas; and in Sweden, some of the most contaminated sites are being remediated. Generic guideline values for soil use after so-called successful remediation actions of PAH-contaminated soil are based on the 16 EPA priority pollutants, which only constitute a small part of the complex cocktail of toxicants in many contaminated soils. The aim of the study was to elucidate if the actual toxicological risks of soil samples from successful remediation projects could be reflected by chemical determination of these PAHs. We compared chemical analysis (GC-MS) and bioassay analysis (H4IIE-luc) of a number of remediated PAH-contaminated soils. The H4IIE-luc bioassay is an aryl hydrocarbon (Ah) receptor-based assay that detects compounds that activate the Ah receptor, one important mechanism for PAH toxicity. Comparison of the results showed that the bioassay-determined toxicity in the remediated soil samples could only be explained to a minor extent by the concentrations of the 16 priority PAHs. The current risk assessment method for PAH-contaminated soil in use in Sweden along with other countries, based on chemical analysis of selected PAHs, is missing toxicologically relevant PAHs and other similar substances. It is therefore reasonable to include bioassays in risk assessment and in the classification of remediated PAH-contaminated soils. This could minimise environmental and human health risks and enable greater safety in subsequent reuse of remediated soils.

  • 317.
    Larsson, Mikael
    Örebro universitet, Akademin för naturvetenskap och teknik.
    A Visualization Tool for Drill Rig Simulators used in Software Development2010Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    Boomer is a machine that is developed and produced by Atlas Copco Rock Drills AB, which is used for underground mining and tunneling. It is a blast-hole drilling rig equipped with drills that are attached to the arms, called booms, which the rig holds. The machine is controlled and monitored by Atlas Copco’s Rig Control System (RCS), which consists of a number of intelligent units connected in a CAN-net. When developing software for the RCS, a simulator that makes it possible to run the software on an ordinary desktop PC is used. The problem is that there is no intuitive way to see how the booms are oriented, while positioning. Therefore it is desirable to have a 3D visualization of the rig, with focus on the booms, which can be used alongside the simulator to get immediate feedback about the movements of the booms. This report describes the process of developing an application that handles communication with the simulator and the 3D visualization.

  • 318.
    Larsson, Tord
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Indirekt mätning av rördrommens Botaurus stellaris, trastsångarens Acrocephalus arundinaceus och näktergalens Luscinia luscinia ljudeffektsnivå2010Inngår i: Fåglar i Kvismaren: årsskrift 2009, Örebro: Föreningen Kvismare fågelstation , 2010, nr 156Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    The purpose of this article is to compare the sound power level of the following birds: Bittern (Botaurus stellaris), Great Reed Warbler (Acrocephalus arundinaceus) and Thrush Nightingale (Luscinia luscinia). The results are achieved by using a new indirect measurement method. This method calculates measurements, using the frequency level of the singing birds as heard by the listening person and the distance of the bird from that same person. 

    In this instance, three examples are used for the calculations; Bittern at a distance of 10.4 km, Great Reed Warbler at a distance of 0.5 - 0.7km and Thrush Nightingale at a distance of 0.7km. The lowest sound power will be achieved, if the 'Bird sound spread' can be at 180 degs semi-circle radiating from the bird. At the chosen distances the following values are obtained: Bittern - 88 db, Thrush Nightingale - 74 db and Great Reed Warbler - 65 db. The biggest uncertainty in obtaining these measurements is the accuracy of the Sound Pressure Loudness Level on the Phonograph and the difficulties of the distance from the bird.

     

  • 319.
    Larsson, Tord
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Validering av partikelavskiljning och produktförändring av en AerosolTrapTM2010Rapport (Annet vitenskapelig)
    Abstract [en]

    Validation and design of a particle trap. The purpose of the project is to measure  a product's (AerosolTrap®) technical properties and to calculate the product with the computer program Ansys workbench. Later on ProE was used for solid modeling, Ansys (Finita element generation) together with Ansys Fluent (flow's - and particle track modeling) in order to evaluate the measured model. In the study  it is shown that these program’s and multivariat analysis can be used to create a product capable of handling for using smaller particles with higher density.The evaluation shows that the measurement properties of technical corresponds well with the computer model concerning airflow and 3-7 mm cell plastic bulbs with density of 32.5 kg m-3. One robust calculation process has also been created.The simulation with multivariat analysis is preformed and a new product, a model, has been created with Ansys workbench. The product properties as airflow, particle density and size can, be controlled with multivariat analysis.

  • 320.
    Laxhammar, Rikard
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Anomaly detection in trajectory data for surveillance applications2011Licentiatavhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Abnormal behaviour may indicate important objects and events in a wide variety of domains. One such domain is intelligence and surveillance, where there is a clear trend towards more and more advanced sensor systems producing huge amounts of trajectory data from moving objects, such as people, vehicles, vessels and aircraft. In the maritime domain, for example, abnormal vessel behaviour, such as unexpected stops, deviations from standard routes, speeding, traffic direction violations etc., may indicate threats and dangers related to smuggling, sea drunkenness, collisions, grounding, hijacking, piracy etc. Timely detection of these relatively infrequent events, which is critical for enabling proactive measures, requires constant analysis of all trajectories; this is typically a great challenge to human analysts due to information overload, fatigue and inattention. In the Baltic Sea, for example, there are typically 3000–4000 commercial vessels present that are monitored by only a few human analysts. Thus, there is a need for automated detection of abnormal trajectory patterns. In this thesis, we investigate algorithms appropriate for automated detection of anomalous trajectories in surveillance applications. We identify and discuss some key theoretical properties of such algorithms, which have not been fully addressed in previous work: sequential anomaly detection in incomplete trajectories, continuous learning based on new data requiring no or limited human feedback, a minimum of parameters and a low and well-calibrated false alarm rate. A number of algorithms based on statistical methods and nearest neighbour methods are proposed that address some or all of these key properties. In particular, a novel algorithm known as the Similarity-based Nearest Neighbour Conformal Anomaly Detector (SNN-CAD) is proposed. This algorithm is based on the theory of Conformal prediction and is unique in the sense that it addresses all of the key properties above. The proposed algorithms are evaluated on real world trajectory data sets, including vessel traffic data, which have been complemented with simulated anomalous data. The experiments demonstrate the type of anomalous behaviour that can be detected at a low overall alarm rate. Quantitative results for learning and classification performance of the algorithms are compared. In particular, results from reproduced experiments on public data sets show that SNN-CAD, combined with Hausdorff distance  for measuring dissimilarity between trajectories, achieves excellent classification performance without any parameter tuning. It is concluded that SNN-CAD, due to its general and parameter-light design, is applicable in virtually any anomaly detection application. Directions for future work include investigating sensitivity to noisy data, and investigating long-term learning strategies, which address issues related to changing behaviour patterns and increasing size and complexity of training data.

  • 321.
    LeBlanc, Kevin
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Cooperative anchoring: sharing information about objects in multi-robot systems2010Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    In order to perform most tasks, robots must perceive or interact with physicalobjects in their environment; often, they must also communicate and reasonabout objects and their properties. Information about objects is typically produced,represented and used in different ways in various robotic sub-systems. Inparticular, high-level sub-systems often reason with object names and descriptions,while low-level sub-systems often use representations based on sensordata. In multi-robot systems, object representations are also distributed acrossrobots. Matters are further complicated by the fact that the sets of objects consideredby each robot and each sub-system often differ.Anchoring is the process of creating and maintaining associations betweendescriptions and perceptual information corresponding to the same physicalobjects. To illustrate, imagine you are asked to fetch “the large blue book fromthe bookshelf”. To accomplish this task, you must somehow associate the descriptionof the book you have in your mind with the visual representation ofthe appropriate book. Cooperative anchoring deals with associations betweendescriptions and perceptual information which are distributed across multipleagents. Unlike humans, robots can exchange both descriptions and perceptualinformation; in a sense, they are able to “see the world through each other’seyes”. Again, imagine you are asked to fetch a particular book, this time fromthe library. But now, in addition to your own visual representations, you alsohave access to information about books observed by others. This can allow youto find the correct book without searching through the entire library yourself.This thesis proposes an anchoring framework for both single-robot andcooperative anchoring that addresses a number of limitations in existing approaches.The framework represents information using conceptual spaces, allowingvarious types of object descriptions to be associated with uncertainand heterogeneous perceptual information. An implementation is describedwhich uses fuzzy logic to represent, compare and combine information. Theimplementation also includes a cooperative object localisation method whichtakes uncertainty in both observations and self-localisation into account. Experimentsusing simulated and real robots are used to validate the proposedframework and the cooperative object localisation method.

  • 322.
    LeBlanc, Kevin
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Cooperative anchoring in heterogeneous multi-robot systems2008Inngår i: IEEE international conference on robotics and automation, ICRA 2008, New York: IEEE , 2008, s. 3308-3314Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Highly heterogeneous robotic systems are becoming increasingly common, as are robotic systems integrated with smart environments. In such distributed systems, there are many different sources and types of information, which need to be coordinated and combined effectively. The problem of \emph{cooperative anchoring} is (roughly) the problem of, in a distributed system, determining which items of information refer to the same objects, and combining these items accordingly. In this paper, we define a general computational framework for cooperative anchoring inspired by work on conceptual spaces and (single-robot) perceptual anchoring. We also discuss an implementation of this framework which uses tools from fuzzy logic, and we present an illustrative experiment.

  • 323.
    LeBlanc, Kevin
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Multirobot Object Localization: A Fuzzy Fusion Approach2009Inngår i: IEEE transactions on systems, man and cybernetics. Part B. Cybernetics, ISSN 1083-4419, E-ISSN 1941-0492, Vol. 39, nr 5, s. 1259-1276Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, we address the problem of fusing information about object positions in multirobot systems. Our approach is novel in two main respects. First, it addresses the multirobot object localization problem using fuzzy logic. It uses fuzzy sets to represent uncertain position information and fuzzy intersection to fuse this information. The result of this fusion is a consensus among sources, as opposed to the compromise achieved by many other approaches. Second, our method fully propagates self-localization uncertainty to object-position estimates. We evaluate our method using systematic experiments, which describe an input-error landscape for the performance of our approach. This landscape characterizes how well our method performs when faced with various types and amounts of input errors.

  • 324. Lee, Duk-Hee
    et al.
    Lind, P. Monica
    Jacobs, David R., Jr.
    Salihovic, Samira
    Örebro universitet, Akademin för naturvetenskap och teknik.
    van Bavel, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Lind, Lars
    Polychlorinated Biphenyls and Organochlorine Pesticides in Plasma Predict Development of Type 2 Diabetes in the Elderly2011Inngår i: Diabetes Care, ISSN 0149-5992, E-ISSN 1935-5548, Vol. 34, nr 8, s. 1778-1784Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    OBJECTIVE-Persistent organic pollutants (POPs), lipophilic chemicals that accumulate mainly in adipose tissue, have recently been linked to type 2 diabetes. However, evidence from prospective studies is sparse. This study was performed to evaluate prospective associations of type 2 diabetes with selected POPs among the elderly. RESEARCH DESIGN AND METHODS-Nineteen POPs (14 polychlorinated biphenyl [PCB] congeners, 3 organochlorine pesticides, 1 brominated diphenyl ether, and 1 dioxin) were measured in plasma collected at baseline in 725 participants, aged 70 years, of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). RESULTS-After adjusting for known type 2 diabetes risk factors, including obesity, odds ratios (ORs) (95% CIs) for type 2 diabetes at age 75 years (n = 36) according to the quintiles of a summary measure of concentrations of PCBs (vs. the lowest quintile) were 4.5, 5.1, 8.8 (1.8-42.7), and 7.5 (1.4-38.8) (P(trend) <0.01). Among organochlorine pesticides, adjusted ORs across concentrations of trans-nonachlor showed that P(trend) = 0.03. Adjusted ORs (95% CIs) across quintiles of the sum of three organochlorine pesticides were 1.1, 1.6, 1.5, and 3.4 (1.0-11.7) (P(trend) = 0.03). Neither brominated diphenyl ether 47 nor dioxin was significantly associated with incident diabetes. The sum of PCBs improved reclassification significantly when added to traditional risk factors for diabetes. CONCLUSIONS-Despite the small number of incident cases, this study found that environmental exposure to some POPs substantially increased risk of future type 2 diabetes in an elderly population.

  • 325.
    Lenells, Erik
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Hjärtmyr, Christian
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Utveckling av kompatibilitetsdatabas2011Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    This report explains the need to develop a configuration manager that handles transmission equipment which exists in the Swedish Defence telecommunications network. The configuration module will display the configurations and compatibility among the equipment and their software which are all part of the network.

    Also included in this report are tools, methods and results for the development of a prototype for the configuration manager. The prototype consists fundamentally of a database assisted by a user friendly website.

    The transmission equipment handles a lot of important transmission of information and is in the hands of a department of SAAB, OFGCA, by orders from the Swedish Defence Materiel Administration (FMV). Within the work included in this order exists a continuous update of both software and hardware which the equipment consists of. Therefore it’s highly important that there is a monitoring of which of the software and hardware is compatible with one another, ensuring that the functions of the system work properly.

    The consistent updating has resulted in compatibility issues between components and because of this, a need for a configuration manager has arisen.

  • 326. Li, X.
    et al.
    Hede, T.
    Tu, Yaoquan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Leck, C.
    Ågren, H.
    Glycine in aerosol water droplets: a critical assessment of Kohler theory by predicting surface tension from molecular dynamics simulations2011Inngår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 11, nr 2, s. 519-527Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aerosol particles in the atmosphere are important participants in the formation of cloud droplets and have significant impact on cloud albedo and global climate. According to the Kohler theory which describes the nucleation and the equilibrium growth of cloud droplets, the surface tension of an aerosol droplet is one of the most important factors that determine the critical supersaturation of droplet activation. In this paper, with specific interest to remote marine aerosol, we predict the surface tension of aerosol droplets by performing molecular dynamics simulations on two model systems, the pure water droplets and glycine in water droplets. The curvature dependence of the surface tension is interpolated by a quadratic polynomial over the nano-sized droplets and the limiting case of a planar interface, so that the so-called Aitken mode particles which are critical for droplet formation could be covered and the Kohler equation could be improved by incorporating surface tension corrections.

  • 327.
    Li, Xin
    et al.
    Sch Biotechnol, Dept Theoret Chem, Royal Inst Technol, Stockholm, Sweden; China Univ Sci & Technol, Shanghai 200237, Peoples R China.
    Hede, Thomas
    Dept Meteorol, Stockholm Univ, Stockholm, Sweden.
    Tu, Yaoquan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Leck, Caroline
    Dept Meteorol, Stockholm Univ, Stockholm, Sweden.
    Ågren, Hans
    Sch Biotechnol, Dept Theoret Chem, Royal Inst Technol, Stockholm, Sweden.
    Surface-active cis-pinonic acid in atmospheric droplets: A molecular dynamics study2010Inngår i: The Journal of Physical Chemistry Letters, ISSN 1948-7185, Vol. 1, nr 4, s. 769-773Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Water vapor in the atmosphere can condensate and form cloud droplets when there is a certain amount of humidity and a presence of cloud condensation nuclei, and organic solutes called surfactants can significantly lower the surface tension of water — one of the parameters determining cloud droplet population. We here present a molecular dynamics study of the behavior of cis-pinonic acid, a commonly found organic compound in cloud condensation nuclei, and its effect on the surface tension of water clusters. Specifically, the decrease in surface tension is found to depend on not only the concentration of the organic compound but also the droplet size due to the spontaneous assembly of the surfactant molecules on the droplet surface. This leads to the conclusion that the partitioning of the surfactant between the bulk and surface plays an important role in the behavior of atmospheric aerosol particles and thus in their availability for cloud formation.

  • 328. Li, Xin
    et al.
    Rinkevicius, Zilvinas
    Tu, Yaoquan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Tian, He
    Ågren, Hans
    Nuclear magnetic shielding of 113Cd(II) ion in aqua solution: a combined molecular dynamics/density functional theory study2008Inngår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 112, nr 36, s. 11347-11352Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a combined molecular dynamics simulation and density functional theory investigation of the nuclear magnetic shielding constant of the 113Cd(II) ion solvated in aqueous solution. Molecular dynamics simulations are carried out for the cadmium−water system in order to produce instantaneous geometries for subsequent determination of the nuclear magnetic shielding constant at the density functional theory level. The nuclear magnetic shielding constant is computed using a perturbation theory formalism, which includes nonrelativistic and leading order relativistic contributions to the nuclear magnetic shielding tensor. Although the NMR shielding constant varies significantly with respect to simulation time, the value averaged over increasing number of snapshots remains almost constant. The paramagnetic nonrelativistic contribution is found to be most sensitive to dynamical changes in the system and is mainly responsible for the thermal and solvent effects in solution. The relativistic correction features very little sensitivity to the chemical environment, and can be disregarded in theoretical calculations when a Cd complex is used as reference compound in 113Cd NMR experiments, due to the mutual cancelation between individual relativistic corrections.

  • 329. Li, Xin
    et al.
    Rinkevicius, Zilvinas
    Tu, Yaoquan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Tian, He
    Ågren, Hans
    Paramagnetic Perturbation of the 19F NMR Chemical Shift in Fluorinated Cysteine by O2: A Theoretical Study2009Inngår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 113, nr 31, s. 10916-10922Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a combined molecular dynamics and density functional theory study of dioxygen-induced perturbation of the 19F NMR chemical shifts in an aqueous solution of fluorinated cysteine under 100 atm of O2 partial pressure. Molecular dynamics simulations are carried out to determine the dominant structures of O2 and the fluorinated cysteine complexes in water, and the collected structural information is exploited in computation of 19F chemical shifts using density functional theory. The obtained results indicate that the density redistribution of the O2 unpaired electrons between the dioxygen and fluorinated cysteine is responsible for the experimentally observed perturbation of the 19F NMR chemical shifts, where the Fermi contact interaction plays the key role. The O2-induced paramagnetic 19F chemical shift, averaged over the simulation trajectory, is comparable with the reported experimental values, proving the availability of the developed strategy for modeling 19F NMR chemical shifts in the presence of paramagnetic agents in an aqueous solution. The applicability of the combined molecular dynamics/density functional theory approach for dioxygen NMR perturbation to all resonating nuclei including 1H, 13C, 15N, and 19F is emphasized, and the ramification of this for investigations of membrane protein structures is discussed.

  • 330.
    Li, Xin
    et al.
    Sch Biotechnol, Dept Theoret Chem, Royal Inst Technol, Stockholm, Sweden; E China Univ Sci & Technol, Shanghai, People's R China.
    Tu, Yaoquan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Tian, He
    E China Univ Sci & Technol, Shanghai, People's R China.
    Ågren, Hans
    Sch Biotechnol, Dept Theoret Chem, Royal Inst Technol, Stockholm, Sweden.
    Computer simulations of aqua metal ions for accurate reproduction of hydration free energies and structures2010Inngår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 132, nr 10, artikkel-id 104505Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Metal ions play essential roles in biological processes and have attracted much attention in both experimental and theoretical fields. By using the molecular dynamics simulation technology, we here present a fitting-refining procedure for deriving Lennard-Jones parameters of aqua metal ions toward the ultimate goal of accurately reproducing the experimentally observed hydration free energies and structures. The polarizable SWM4-DP water model {proposed by Lamoureux et al. [J. Chem. Phys. 119, 5185 (2003)] } is used to properly describe the polarization effects of water molecules that interact with the ions. The Lennard-Jones parameters of the metal ions are first obtained by fitting the quantum mechanical potential energies of the hexahydrated complex and are subsequently refined through comparison between the calculated and experimentally measured hydration free energies and structures. In general, the derived Lennard-Jones parameters for the metal ions are found to reproduce hydration free energies accurately and to predict hydration structures that are in good agreement with experimental observations. Dynamical properties are also well reproduced by the derived Lennard-Jones parameters.

  • 331.
    Li, Xin
    et al.
    Dept Theoret Chem, Sch Biotechnol, Royal Inst Technol, Stockholm, Sweden; E China Univ Sci & Technol, Shanghai, Peoples R China.
    Zhang, Qiong
    Dept Theoret Chem, Sch Biotechnol, Royal Inst Technol, Stockholm, Sweden; E China Univ Sci & Technol, Shanghai, Peoples R China.
    Tu, Yaoquan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Ågren, Hans
    Dept Theoret Chem, Sch Biotechnol, Royal Inst Technol, Stockholm, Sweden.
    Tian, He
    E China Univ Sci & Technol, Shanghai, Peoples R China.
    Modulation of Iridium(III) phosphorescence via photochromic ligands: a density functional theory study2010Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 12, nr 41, s. 13730-13736Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The photochromic iridium(iii) complex (Py-BTE)(2)Ir(acac) synthesized by Tan et al. [W. Tan et al., Org. Lett. 2009, 11, 161-164] has shown distinct photo-reactivity and photo-controllable phosphorescence. We here present a density functional theory study on the (Py-BTE)(2)Ir(acac) complex to explore the mechanism at the molecular level and to help further design of photochromic iridium(iii) complexes with the desirable properties. The hybrid functional PBE0, with 25% Hartree-Fock exchange, is found to give an optimal structure compared with X-ray crystallographic data. The absorption bands are well reproduced by using time-dependent density functional theory calculations, lending the possibility to assign the metal-to-ligand and intra-ligand charge transfer transitions. The radiative and nonradiative deactivation rate constants, k(r) and k(nr), are rationalized for both the open-ring and closed-ring forms of the complex. The very large k(nr) and small k(r) make the closed-ring form of the complex non-emissive. The triplet reactivity of the Py-BTE ligand is also studied by performing density functional theory calculations on the potential energy surfaces of the ground state and the lowest triplet state

  • 332.
    Lilienthal, Achim J.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Asadi, Sahar
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Reggente, Matteo
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Estimating predictive variance for statistical gas distribution modelling2009Inngår i: Olfaction and electronic nose: proceedings / [ed] Matteo Pardo, Giorgio Sberveglieri, Melville, USA: American Institute of Physics (AIP), 2009, s. 65-68Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Recent publications in statistical gas distribution modelling have proposed algorithms that model mean and variance of a distribution. This paper argues that estimating the predictive concentration variance entails not only a gradual improvement but is rather a significant step to advance the field. This is, first, since the models much better fit the particular structure of gas distributions, which exhibit strong fluctuations with considerable spatial variations as a result of the intermittent character of gas dispersal. Second, because estimating the predictive variance allows to evaluate the model quality in terms of the data likelihood. This offers a solution to the problem of ground truth evaluation, which has always been a critical issue for gas distribution modelling. It also enables solid comparisons of different modelling approaches, and provides the means to learn meta parameters of the model, to determine when the model should be updated or re-initialised, or to suggest new measurement locations based on the current model. We also point out directions of related ongoing or potential future research work.

  • 333.
    Lilienthal, Achim J.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Duckett, TomLincoln School of Computer Science, University of Lincoln, Lincoln, UK.
    Proceedings of the 5th European Conference on Mobile Robots ECMR 2011: September 7-9, 2011, Örebro, Sweden2011Konferanseproceedings (Annet vitenskapelig)
  • 334.
    Lilienthal, Achim J.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Reggente, Matteo
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Trincavelli, Marco
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Blanco, Jose Luis
    Dept. of System Engineering and Automation, University of Malaga.
    Gonzalez, Javier
    Örebro universitet, Akademin för naturvetenskap och teknik.
    A statistical approach to gas distribution modelling with mobile robots: the Kernel DM+V algorithm2009Inngår i: IEEE/RSJ international conference on intelligent robots and systems: IROS 2009, IEEE conference proceedings, 2009, s. 570-576Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Gas distribution modelling constitutes an ideal application area for mobile robots, which – as intelligent mobile gas sensors – offer several advantages compared to stationary sensor networks. In this paper we propose the Kernel DM+V algorithm to learn a statistical 2-d gas distribution model from a sequence of localized gas sensor measurements. The algorithm does not make strong assumptions about the sensing locations and can thus be applied on a mobile robot that is not primarily used for gas distribution monitoring, and also in the case of stationary measurements. Kernel DM+V treats distribution modelling as a density estimation problem. In contrast to most previous approaches, it models the variance in addition to the distribution mean. Estimating the predictive variance entails a significant improvement for gas distribution modelling since it allows to evaluate the model quality in terms of the data likelihood. This offers a solution to the problem of ground truth evaluation, which has always been a critical issue for gas distribution modelling. Estimating the predictive variance also provides the means to learn meta parameters and to suggest new measurement locations based on the current model. We derive the Kernel DM+V algorithm and present a method for learning the hyper-parameters. Based on real world data collected with a mobile robot we demonstrate the consistency of the obtained maps and present a quantitative comparison, in terms of the data likelihood of unseen samples, with an alternative approach that estimates the predictive variance.

  • 335.
    Liljelind, I.
    et al.
    Dept Publ Hlth & Clin Med, Umeå Univ, Umeå, Sweden.
    Norberg, C.
    Örebro University Hopital, Örebro, Sweden; Department of Natural Sciences, Örebro University, Örebro, Sweden.
    Egelrud, L.
    IVL Swedish Environm Res Inst Ltd, Stockholm, Sweden.
    Westberg, Håkan
    Örebro universitet, Akademin för naturvetenskap och teknik. Örebro University Hospital, Örebro, Sweden.
    Eriksson, K.
    Dept Occupat & Environm Med, Umeå Univ Hosp, Umeå, Sweden.
    Nylander-French, L. A.
    Dept Environm Sci & Engn, Gillings Sch Global Publ Hlth, Univ N Carolina, Chapel Hill NC, USA.
    Dermal and Inhalation Exposure to Methylene Bisphenyl Isocyanate (MDI) in Iron Foundry Workers2010Inngår i: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 54, nr 1, s. 31-40Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Diisocyanates are a group of chemically reactive agents, which are used in the production of coatings, adhesives, polyurethane foams, and parts for the automotive industry and as curing agents for cores in the foundry industry. Dermal and inhalation exposure to methylene bisphenyl isocyanate (MDI) is associated with respiratory sensitization and occupational asthma. However, limited research has been performed on the quantitative evaluation of dermal and inhalation exposure to MDI in occupationally exposed workers. The objective of this research was to quantify dermal and inhalation exposure levels in iron foundry workers. Workers involved in mechanized moulding and mechanized production of cores were monitored: 12 core makers, 2 core-sand preparers, and 5 core installers. Personal breathing-zone levels of MDI were measured using impregnated filter sampling. Dermal exposure to MDI was measured using a tape-strip technique. Three or five consecutive tape-strip samples were collected from five exposed skin areas (right and left forefingers, left and right wrists, and forehead). The average personal air concentration was 0.55 mu g m(-3), 50-fold lower than the Swedish occupational exposure limit of 30 mu g m(-3). The core makers had an average exposure of 0.77 mu g m(-3), which was not significantly different from core installers' and core-sand preparers' average exposure of 0.16 mu g m(-3) (P = 0.059). Three core makers had a 10-fold higher inhalation exposure than the other core makers. The core makers' mean dermal exposure at different skin sites varied from 0.13 to 0.34 mu g while the two other groups' exposure ranged from 0.006 to 0.062 mu g. No significant difference was observed in the MDI levels between the skin sites in a pairwise comparison, except for left forefinger compared to left and right wrist (P < 0.05). In addition, quantifiable but decreasing levels of MDI were observed in the consecutive tape strip per site indicating MDI penetration into the skin. This study indicates that exposure to MDI can be quantified on workers' skin even if air levels are close to unquantifiable. Thus, the potential for uncured MDI to deposit on and penetrate into the skin is demonstrated. Therefore, dermal exposure along with inhalation exposure to MDI should be measured in the occupational settings where MDI is present in order to shed light on their roles in the development of occupational isocyanate asthma.

  • 336.
    Lindh, Ingrid
    Örebro universitet, Akademin för naturvetenskap och teknik. Örebro universitet.
    Development of transgenic Arabidopsis thaliana and Daucus carota plant producing the p24 capsid protein from HIV-1 subtype C for the use as an edible plant-based vaccine model2009Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 337.
    Lindh, Ingrid
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Plant-produced STI vaccine antigens with special emphasis on HIV-1 p242011Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Objective: To establish stable transgenic non-toxic plants as a platform for plant-based vaccine production as well as potential oral delivery system of vaccine antigens for sexually transmitted infections (STIs). The concept is to immunize the mucosal immune system present in the gut-associated lymphoid tissues (GALT). HIV-1 p24 subtype C protein has been used as the main antigen model, in parallel with an engineered unique chimeric MOMP antigen from Chlamydia trachomatis serovar E.

    Methods: Chimeric MOMP and p24 vaccine antigens were successfully inserted into the nuclear genomes of Arabidopsis thaliana and Daucus carota via Agrobacterium-mediated gene transfer. The characteristics of the genetic inserts and corresponding mRNAs and recombinant proteins in planta were described using several methods, including northern, Southern, and western blotting, ELISA, and a commercial HIV Ag/Ab combination assay. Immunogenicity of the antigens was studied in mice models.

    Results: Transgenes of both plant species expressing p24 or chimeric MOMP were successfully generated. Additional HIV-1 vaccine antigen candidates were introduced and the genetic inserts have been confirmed in Arabidopsis thaliana. The Arabidopsis thaliana expressing p24 and chimeric MOMP were demonstrated to be stable over generations and antigenicity analyses showed that plant-derived HIV-1 p24 and chimeric MOMP retained immunological epitopes when they were expressed in planta. Oral administration of transgenic plant material generated a priming effect of the immune competent cells present in the GALT, shown by the presence of antigen-specific-IgG in mice sera after boosting. Mice immunized with plant-derived HIV-1 p24 antigen were also analyzed for antigen-specific faecal IgA as well as cellular immune responses. However, detectable levels of the two latter immune responses were not observed. The Chlamydia trachomatis chimeric MOMP antigen was further evaluated for its potential as a vaccine antigen candidate, with positive results indicating a more rapid clearance of the Chlamydia trachomatis infection post immunization.

    Conclusion: Stable non-toxic transgenic plants expressing either HIV-1 p24 or a novel  Chlamydia trachomatis chimeric MOMP antigens have successfully been developed. The two plant-produced STI vaccine antigens have in initial mice feeding studies provided important proof-of-concept for the oral vaccination approach. Now, immunization studies to expand, en-hance, and improve knowledge of the immune responses generated by the orally delivered transgenic plants are of high priority.

  • 338.
    Lindh, Ingrid
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Andersson, Sören
    Universitetssjukhuset i Örebro, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Plant-based production of HIV antigens: towards a candidate for an edible vaccine2010Inngår i: In Vivo, ISSN 0258-851X, E-ISSN 1791-7549, Vol. 24, nr 3, s. 368-370Artikkel i tidsskrift (Fagfellevurdert)
  • 339.
    Lindh, Ingrid
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bråve, Andreas
    Hallengärd, David
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Andersson, Sören
    Oral delivery of plant-derived HIV-1 p24 antigen in low doses shows a superior priming effect in mice compared to high dosesManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    During early infection with human immunodeficiency virus type 1 (HIV-1), there is a rapid depletion of CD4+ T-cells in the gut-associated lymphoid tissue (GALT) in the gastrointestinal tract. Therefore, immediate protection at these surfaces is of high priority for the development of an HIV-1 vaccine. Thus, transgenic plants expressing HIV-1 p24 antigen, which is released by immune competent cells in the GALT during oral administration, are interesting as potential vaccine candidates. In the present study, we used two HIV-1 p24 transgenic plant systems, Arabidopsis thaliana and Daucus carota, in oral immunization experiments. Both transgenic plant systems showed a priming effect in mice and induced humoral immune responses, which could be detected as anti-p24-specific-IgG in sera after an intramuscular p24 protein boost. Initial dose-dependent antigen analyses using transgenic Arabidopsis thaliana indicated that low p24 antigen doses were superior to high p24 antigen doses. No detectable levels of faecal IgA antibodies or cellular immune responses were observed.

  • 340.
    Lindh, Ingrid
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kalbina, Irina
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Hedberg, Sara Thulin
    Scherbak, Nikolai
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sävenstrand, Helena
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Bråve, Andreas
    Hinkula, Jorma
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Andersson, Sören
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Feeding of mice with Arabidopsis thaliana expressing the HIV-1 subtype C p24 antigen gives rise to systemic immune responses2008Inngår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 116, nr 11, s. 985-994Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Development of transgenic edible plants, to be used as production, storage and delivery systems for recombinant vaccine antigens, is a promising strategy to obtain cost effective vaccines against infectious diseases, not the least for use in developing countries. Therefore, we used Agrobacterium tumefaciens-mediated gene transfer to introduce the p24 gag gene encoding the nucleocapsid protein from HIV-1 subtype C into the Arabidopsis thaliana plant genome. Eighteen plant lines were confirmed positive for the p24 gene by PCR, four of these lines showed an apparent homozygous phenotype when grown on selective medium and these lines also showed transcription of the p24 gene into its corresponding mRNA. The mRNA in all four cases generated the p24 protein in plants, as verified by western blot analysis. The plants were shown to contain between 0.2 µg and 0.5 µg p24 protein per g of fresh tissue. Analysis of the localisation of the p24 protein showed that stem tissue contained the largest amount of protein, more than twice as much as leaf tissue, whereas no p24 protein was detected in roots. By using Southern blotting, we found that 4, 2-3, 2 and 1 T-DNA insertion events took place in the four lines 1, 2, 7, and 10, respectively. The genetic insertions of line 1 were stable from the T1 to the T4 generation and gave rise to the p24 protein in all cases, as verified by western blotting. In mice fed with fresh transgenic A. thaliana (line 10), anti-gag IgG was obtained in serum after a booster injection with recombinant p37Gag. No immune response was observed after equal booster injection of untreated mice or mice fed with A. thaliana WT plants.

  • 341.
    Lindh, Ingrid
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Wallin, Anita
    Evolutionsbiologiskt Centrum, Uppsala universitet.
    Kalbina, Irina
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Sävenstrand, Helena
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Engström, Peter
    Uppsala Universitet.
    Andersson, Sören
    Smittskyddsinstitutet.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Production of the p24 capsid protein from HIV-1 subtype C in Arabidopsis thaliana and Daucus carota using an endoplasmic reticulum-directing SEKDEL sequence in protein expression constructs2009Inngår i: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 66, nr 1, s. 46-51Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An optimized gene expression construct was designed in order to increase the accumulation of the HIV-1 subtype C p24 protein in Arabidopsis thaliana and carrot (Daucus carota) plants. An ER retention signal was introduced into the genetic construct generating a p24 protein containing a SEKDEL amino acid sequence at its C-terminus. Mature A. thaliana plants and carrot cells were transformed using Agrobacterium tumefaciens carrying the improved pGreen0229/p24_SEKDEL vector. Several transgenic plant lines were obtained from both plant species by growth on selective medium and confirmed by PCR. Transformed lines were analyzed for p24 protein content by western blotting using anti-p24-specific antibodies and by Southern blotting to establish the number of copies of the insert in the plant nuclear genome. To estimate the accumulation levels of p24 protein in the plants, ELISA was run using soluble plant extracts. By comparing these results with our previous findings, the ER retention signal increased the level of p24 protein 5-fold in the Arabidopsis thaliana plants. In carrot taproot, the content of p24_SEKDEL protein was approximately half of that in Arabidopsis on a fresh weight basis and was stable in planta for several months. However, on a total soluble protein basis, carrots produced considerable higher levels of the p24_SEKDEL protein than Arabidopsis.

  • 342.
    Lindström, Gunilla
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kärrman, Anna
    Örebro universitet, Akademin för naturvetenskap och teknik.
    van Bavel, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Accuracy and precision in the determination of perfluorinated chemicals in human blood verified by interlaboratory comparisons2009Inngår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1216, nr 3, s. 394-400Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Perfluorinated chemicals, PFCs, are analyzed in laboratories worldwide to determine human blood levels and exposure pathways. The development of the  nalytical echnique has been rapid in the last ten years, and prerequisites for accurate and precise determination of PFCs in human blood at low ng/g concentrations are today readily available. The main contributing factors are the improved LC-MS instrumentations, the increased availability of native and mass labeled PFC standards, and new column materials available for chromatographic separations. The results of the first international interlaboratory study (ILS) in 2005 on PFCs revealed relatively better analytical results for human blood analyses when compared to analyses of a number of environmental matrices. The representative accuracy for the analyses of PFCs in human matrixes reported in recent years was established in the second human serum ILS in 2006. Interlaboratory standard deviations for the two human serum samples one low level concentration and one medium level concentration were found to be 12% and 16% for PFOS, respectively, and 47% and 21% for PFOA, respectively. Reported detections for all PFCs followed a frequency of PFOS>PFOA>PFHxS>PFNA>PFDA>>PFDoA>> PFDS>>PFHxA. Due to the small number of reported values for the other perfluorosulfonates and perfluorocarboxylates, standard deviations were not established.

     

  • 343.
    Logrell, Viktor
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Administrativ webbplattform med ett bokningssystem för en upplevelseleverantör2011Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    This report is about the development of an administrative web platform for experience suppliers. A web platform like this gives access to administration of employees, activities and tickets for experiences. It also makes it possible to perform experience activities in three phases. These phases are preparation, execution and reporting of experiences.

    The web platform makes it possible to let customers book experience activities themselves by using tickets, gift cards or vouchers. The work that is involved in the ticket management is performed automatically and is adjustable through parameters controlled by an administrator. These parameters help to maximize the number of participants per experience activity. This improves things like fuel consumption for experience activities such as air ballooning.

    The development of the web platform was done by a student in the form of a final examination project at Örebro University for Airventures (Sweden).

  • 344.
    Lopez-Paredes, Adolfo
    et al.
    INSISOC, Universidad de Valladolid, Escuela de Ingenierias Industriales Paseo del Cauce, Valladolid, Spain.
    Edmonds, Bruce
    Centre for Policy Modelling, Manchester Metropolitan University, Manchester, United Kingdom.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Special issue: Agent based simulation of complex social systems2012Inngår i: Simulation (San Diego, Calif.), ISSN 0037-5497, E-ISSN 1741-3133, Vol. 88, nr 1, s. 4-6Artikkel i tidsskrift (Fagfellevurdert)
  • 345.
    Louloudi, Athanasia
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Evaluation of a Bisensor System for 3D Modeling of Indoor Environments2010Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Three dimensional (3D) sensing, analysis and reconstruction of objects and scenesin unknown environments has become an important area of research in several disciplines.Recently, Time-of-Flight (ToF) cameras have attracted attention because oftheir advantageous ability to generate full 3D range distance information at videoframe rates. However, several challenging fluctuations like systematic or random errorscan occur and thus decrease the quality of the acquired data. Therefore, the usabilityof such systems is very much dependent on an accurate camera calibration. Inaddition, ToF cameras have still limited resolution (e.g. 176x144) and they can onlyprovide monochromatic (grayscale) information.This work concentrates on the fusion of 2D vision and 3D range data in order toobtain accurate and visually appealing representations of real indoor environments. Inparticular two major fields of research are treated. The first concerns the compensationof the common errors that the ToF cameras present. This is achieved by performing acalibration schema that additionally sets the ground towards the creation of a commonreference frame for both sensors. The second task is to incorporate these two differentsensors into one system that exhibits improved accuracy and high quality output data.The calibration process addresses both photogrammetric and depth correction techniques.Moreover, due to the fact that the real world scenes increase the level of difficultythat such a system has to confront, a validation of the ToF cameras performanceemerges as an important need. For this purpose, a novel approach to evaluate and get abetter insight on the accuracy of the ToF camera is introduced, based on a 3D NormalDistribution Transform.Finally, as sensor fusion plays an important role in this work, multi-sensor applicationsare further investigated based on the incorporation of such a biform sensorysystem. Principle goal is to communicate the color information and enhance the overallresult by the use of 3D surface reconstruction approaches.

     

  • 346.
    Louloudi, Athanasia
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Towards a generic connection between agent behaviour and visualisation2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    When interfacing standard agent-based simulations with Virtual Reality (VR) systems online during simulation, an important aspect to be addressed is what information needs to be tackled on both sides and how to relate this information. This is not a trivial task as it involves the association of abstract domain-specific agent properties in the simulation to low level information in the virtual world. During runtime, sufficient and appropriate information from the simulation has to be sent in a way that can be processed by the VR system. We want to identify a generic way for mapping the information which describes the state and context a simulated agent is in, to its detailed 3D representation inside a VR system. Hereby, the different time granularities of the two system form a core problem for maintaining consistency between the two platforms. In this contribution we discuss in detail the issues involved, propose generic representations as well as procedures to fill them. Finally we present a first prototype and its performance evaluation. 

  • 347.
    Louloudi, Athanasia
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Visualizing agent-based simulation dynamics in a CAVE: issues and architectures2011Inngår i: 2011 Federated Conference on Computer Science and Information Systems (FedCSIS), IEEE, 2011, s. 651-658Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Displaying an agent-based simulation on an immersivevirtual environment called CAVE (Cave Automatic Virtual Environment), a human expert is enabled to evaluate the simulation’s dynamics from the same point of view as in real life- from a within perspective instead of a birds eye view. As thisform of face validation is useful for many multiagent simulations,it should be possible to setup such a system with as little effortas possible. In this context, we systematically analyse the critical issues that a realization of such a system raises. Addressing these problems, we finally discuss design aspects of basic frameworkarchitectures.

  • 348.
    Louloudi, Athanasia
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Mosallam, Ahmed
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Marturi, Naresh
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Janse, Pieter
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Hernandez Bennetts, Victor
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Integration of the humanoid robot Nao inside a smart home: a case study2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a case study demonstrating the integration of the humanoid robotic platform Nao within a Network Robot System (NRS) application. The specific scenario of interest takes place in a smart home environment; the task being that of bringing a can of soda from a fridge to a human user. We use this concrete scenario to evaluate how the performance of such a robot can be affected by being embedded inside an intelligent domestic environment. This study points out that, by cooperating with different components on the network the overall performance of the robot is increased.

  • 349.
    Loutfi, Amy
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Coradeschi, Silvia
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Odor Recognition for Intelligent Systems2008Inngår i: IEEE Intelligent Systems, ISSN 1541-1672, Vol. 23, nr 1, s. 41-48Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An electronic nose is an intelligent sensing device that uses a gas sensor array of partial and overlapping selectivity along with a pattern-recognition component to distinguish between simple and complex odors. To date, researchers have used e-noses in many applications and domains, from the food industry to medical diagnosis. A next stage in e-nose development is to introduce artificial olfaction into integrated systems, so e-noses can work with other sensors on more complex platforms, such as on mobile robots or in intelligent environments. Here, the authors offer an overview of the more critical challenges in integrating this important sense into intelligent systems. They also discuss Pippi, a mobile robot that uses different sensing modalities (visual, sonar, tactile, and e-nose sensors) along with high-level processes (planners and symbolic reasoning) to accomplish several olfactory-related tasks.

  • 350.
    Loutfi, Amy
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Coradeschi, Silvia
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Daoutis, Marios
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Melchert, Jonas
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Using Knowledge Representation for Perceptual Anchoring in a Robotic System2008Inngår i: International Journal on Artificial Intelligence Tools, ISSN 0218-2130, Vol. 17, nr 5, s. 925-944Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work we introduce symbolic knowledge representation and reasoning capabilities to enrich perceptual anchoring. The idea that encompasses perceptual anchoring is the creation and maintenance of a connection between the symbolic and perceptual description that refer to the same object in the environment. In this work we further extend the symbolic layer by combining a knowledge representation and reasoning (KRR) system with the anchoring module to exploit a knowledge inference mechanisms. We implemented a prototype of this novel approach to explore through initial experimentation the advantages of integrating a symbolic knowledge system to the anchoring framework in the context of an intelligent home. Our results show that using the KRR we are better able to cope with ambiguities in the anchoring module through exploitation of human robot interaction.

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