Sensor Fused Indoor Positioning Using Dual Band WiFi Signal Measurements

In this paper, signal strengths from known WiFi access points are used together with a particle filter to perform indoor navigation. It is shown that more information is obtained by using signals of both 2.4 and 5.0 GHz, compared to using only one frequency. Thus, using both frequencies provides a more accurate positioning. The second contribution is an algorithm where WiFi measurements are combined with pedestrian dead reckoning (PDR), which is based on step counting using an accelerometer and hypotheses of the heading using a gyroscope. This was found to provide further accuracy compared to more conventional methods

Were the 1950s a Golden Age in Baghdad? The Role of Nostalgia and Nationalism

Those who study the history of classical and medievalIslam have their golden ages. For medievalists, for example,the Baghdad of the Abbasid Caliphate is often considered theultimate historical epoch when the city was the pivot of theuniverse and the epicenter of science, scholarship, and trade.(1) But do modern historians have a golden age that they couldlook towards and study? Does Baghdad, for example, have amodern Golden Age?For the last 15 years, I have been asking a number of Iraqisthis very question. The most typical answer that I get is thatthe years between 1948-1958 were distinct and a time ofexcitement and optimism. The consensus seems to be that ifthere ever was a golden age in the modern era, it would befound in the 1950s. There is a great sense of nostalgia for thisera. Interestingly, people from all sides of the political spectrumhave fond memories of this time whether they were communistsor conservative monarchists

Healing Processes in Cancellous Bone

Most of what is known about the biological response during fracture healing comes from numerous animal studies with shaft fractures in the long bone. However, most patients suffer from fractures closer to the ends of the long bones, in the hip, or in the vertebrae. These types of fractures mainly involve cancellous bone, while shaft fractures concern cortical bone. Compared to cortical bone whose structure is dense and compact, cancellous bone is of spongy and porous structure. A growing number of studies point towards that cortical and cancellous bone heal differently. To even this imbalance in knowledge between these two types of bone tissue, further studies in cancellous bone are justified. In this thesis we delved into the quiet unknown processes behind cancellous bone healing. In the first study we characterized and compared two models for cancellous bone healing in mice and rats: the first model can be used to analyze the morphology and morphometry of the regenerating bone; the second model can measure the mechanical properties of cancellous bone. The two models correspond in their developing patterns during the first week before they diverge. This suggests that these models can be utilized together to evaluate the initial healing in cancellous bone. Furthermore, we saw in the drill hole model that the bone formation is strictly restricted to the traumatized region, with a distinct interface to the adjacent uninjured tissue. The second study characterized the cellular response during the initial healing phase in cancellous bone. The focus was to follow the spatial location of inflammatory and osteogenic cells over time in a cancellous bone injury. In contrast to shaft fractures (cortical bone), where healing is described as sequential events where inflammatory cells are the first to arrive to the trauma before osteogenic cells are recruited and initiate healing, we could see how inflammatory and osteogenic cells appeared early, simultaneously after a cancellous bone injury. This study showed that cancellous bone differs from how fracture healing is normally described. In the third study we explored the role of a subpopulation of lymphocytes (CD8 positive cells), earlier studied in shaft fractures. We wanted to see how their absence would affect the healing in a cancellous bone injury. Without CD8+ cells, cancellous bone healing was impaired as expressed via poorer mechanical properties of the regenerated bone tissue. The fourth and last study issued the influence of uninjured bone marrow on cortical bone healing. We developed a cortical defect model which blocked uninjured marrow from reaching the defect. Without the presence of marrow, the cortical defects ability to regenerate was significantly impaired. This implies that the marrow is important for cortical bone healing. In conclusion, cancellous bone healing is different from its cortical counterpart and the general perception of fracture healing. We have briefly discerned healing mechanisms in cancellous bone that might be of clinical importance: the restricted cancellous bone formation is something to take into consideration when performing arthrodeses; and importance of marrow in skeletal defects (e.g. pseudarthroses). With this thesis, we hope to promote that further investigating on cancellous bone healing is necessary

Realtime Volume Visualization of Time Evolving Nebulae for Immersive Environments

This paper presents the result of our master thesis work in media technology, which is an implementation of a realtime volume rendering engine capable of visualizing reflection nebulae. The engine is using scattering and emission properties of time evolving volumetric data, created by astrophysicists at the Hayden Planetarium, New York. The visualization is designed towards full dome planetarium displays. Using the latest GPU based techniques for volume rendering and impostor techniques we are able to interactively fly around as well as animate several nebulae embedded in their true astronomical content. This paper is aimed towards fellow media technology students and people interested in the area of realtime volume renderings. It is written with the presumption that the reader has the same knowledge as we did when starting our thesis work, which implies good confidence in modern 3D computer graphics, some experience in object-oriented programming and basic knowledge of algebra and calculus. It is our hope that this report can be enjoyed even if skipping some of the more technical parts

Osteoblast precursors and inflammatory cells arrive simultaneously to sites of a trabecular-bone injury

Background and purpose - Fracture healing in the shaft is usually described as a sequence of events, starting with inflammation, which triggers mesenchymal tissue formation in successive steps. Most clinical fractures engage cancellous bone. We here describe fracture healing in cancellous bone, focusing on the timing of inflammatory and mesenchymal cell type appearance at the site of injury. Material and methods - Rats received a proximal tibial drill hole, A subgroup received clodronate-containing liposomes before or after surgery. The tibiae were analyzed with micro-CT and immunohistochemistry 1 to 7 days after injury. Results - Granulocytes (myeloperoxidase) appeared in moderate numbers within the hole at day 1 and then gradually disappeared. Macrophage expression (CD68) was seen on day 1, increased until day 3, and then decreased. Mesenchymal cells (vimentin) had already accumulated in the periphery of the hole on day 1. Mesenchymal cells dominated in the entire lesion on day 3, now producing extracellular matrix. A modest number of preosteoblasts (RUNX2) were seen on day 1 and peaked on day 4. Osteoid was seen on day 4 in the traumatized region, with a distinct border to the uninjured surrounding marrow. Clodronate liposomes given before the injury reduced the volume of bone formation at day 7, but no reduction in macrophage numbers could be detected. Interpretation - The typical sequence of events in shaft fractures was not seen. Mesenchymal cells appeared simultaneously with granulocyte and macrophage arrival. Clodronate liposomes, known to reduce macrophage numbers, seemed to be associated with the delineation of the volume of tissue to be replaced by bone

Realtime Volume Visualization of Time Evolving Nebulae for Immersive Environments

This paper presents the result of our master thesis work in media technology, which is an implementation of a realtime volume rendering engine capable of visualizing reflection nebulae. The engine is using scattering and emission properties of time evolving volumetric data, created by astrophysicists at the Hayden Planetarium, New York. The visualization is designed towards full dome planetarium displays. Using the latest GPU based techniques for volume rendering and impostor techniques we are able to interactively fly around as well as animate several nebulae embedded in their true astronomical content. This paper is aimed towards fellow media technology students and people interested in the area of realtime volume renderings. It is written with the presumption that the reader has the same knowledge as we did when starting our thesis work, which implies good confidence in modern 3D computer graphics, some experience in object-oriented programming and basic knowledge of algebra and calculus. It is our hope that this report can be enjoyed even if skipping some of the more technical parts

Suppression av Ljud - En experimentell studie som undersöker effekten av att tänka bort ljud

Många människor har påträngande tankar och uppfattar dessa som jobbiga. En vanligt förekommande copingstrategi är att tränga bort dessa upplevelser. Detta kallas suppression eller bortträngning och har kopplingar till psykiatriska besvär. Tidigare studier visar att bortträngning har en ironisk effekt som gör att de tankar en person önskar undvika studsar tillbaka in i medvetandet. I denna experimentella studie används en inomgruppsdesign för att undersöka huruvida denna ironiska effekt går att återfinna hos externa stimuli i form av sinustoner. Testdeltagare (n=40) instruerades att tränga undan eller fokusera på en av två toner. Den första hypotesen var att deltagarna under en tone-in-noise uppgift skulle indikera fler falska positiva på den bortträngda tonen, jämfört med den ton de fokuserade på eller vid ingen ton alls. Detta skulle då indikera på en ironisk effekt. Ytterligare hypoteser var att deltagare kommer ha fler sanna positiva på den bortträngda tonen jämfört med en kontrollton, även detta under brus. Sista hypotesen var att deltagarnas upplevelse av den bortträngda tonen skulle förändras och skattas som mer aversiv efter experimentet. Resultaten stödde ej någon av hypoteserna. Explorativa analyser visade att deltagarna upplevde båda tonerna som mer irriterande, uppjagande och att de lät högre efter en minnesuppgift. Studiens begränsningar diskuteras och förändringar i studiedesign föreslås.Many people have intrusive thoughts that they experience as aversive. A common coping strategy is to suppress these thoughts. This practice has connections to psychiatric problems. Previous studies have shown that suppression has an ironic process, where the suppressed material has a rebound effect and re-enters consciousness. Furthermore, suppression can have an effect on the emotional perception of the suppressed material. In this experimental study a within-subjects design was used to examine if this ironic effect can be found when suppression is used on external stimuli such as sine tones. Participants (n=40) were instructed to either suppress or focus on two different tones. The hypothesis was that they would indicate more false positives on the suppressed tone during a tone-in-noise task, which would be a sign of a rebound effect. Furthermore, it was hypothesized that participants would have more correct identifications when the suppressed tone was present during the tone-in-noise task. Lastly it was hypothesized that participants would rate the suppressed tone as more aversive. The results did not support any of the hypotheses. Explorative analyses showed that participants rated both tones as more arousing, annoying, and loud after a recall task. Limitations of the study are discussed and changes to the study for further research design are proposed

Abaloparatide versus teriparatide: a head to head comparison of effects on fracture healing in mouse models

Background and purpose - Teriparatide accelerates fracture healing in animals and probably in man. Abaloparatide is a new drug with similar although not identical effects on the teriparatide receptor. Given at 4 times the teriparatide dose in a human osteoporosis trial, abaloparatide increased bone density more than teriparatide, and both reduced fracture risk. We investigated in mice whether abaloparatide stimulates fracture healing, and if it does so with the suggested dose effect relation (4:1). Patients and methods - In a validated mouse model for metaphyseal healing (burr hole with screw pull-out), 96 mice were randomly allocated to 11 groups: control (saline), teriparatide or abaloparatide, where teriparatide and abaloparatide were given at 5 different doses each. In a femoral shaft osteotomy model, 24 mice were randomly allocated to 3 groups: control (saline), teriparatide (15 mu g/kg) or abaloparatide (60 mu g/kg). Each treatment was given daily via subcutaneous injections. Results were evaluated by mechanical testing and microCT. Results - In the metaphyseal model, a dose-dependent increase in screw pull-out force could be seen. In a linear regression analysis (r = 0.78) each increase in ln(dose) by 1 (regardless of drug type) was associated with an increase in pull-out force by 1.50 N (SE 0.18) (p amp;lt; 0.001). Changing drug from teriparatide to abaloparatide increased the force by 1.41 N (SE 0.60; p = 0.02). In the diaphyseal model, the callus density was 23% (SD 10), 38% (SD 10), and 47% (SD 2) for control, for teriparatide and abaloparatide respectively. Both drugs were significantly different from controls (p = 0.001 and p = 0.008), but not from each other. Interpretation - Both drugs improve fracture healing, but in these mouse models, the potency per mu g of abaloparatide seems only 2.5 times that of teriparatide, rather than the 4:1 relation chosen in the clinical abaloparatide-teriparatide comparison trial