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国立情報学研究所で電子化したコンテンツを使用している。

In this thesis, I develop an efficient and user-friendly node-based interface to be used in the creation of a particle system in Autodesk Maya. Maya's interface inconsistencies were identified and solutions were designed based on research in a number of fields related to human-computer interaction (HCI) as well as taking design queues from other highly successful 3D programs that employ a node-based interface. This research was used to guide the design of the interface in terms of organizing the data into logical chunks of information, using color to help the user develop working mental models of the system, and also using simple, easy to identify, graphical representations of a particle system. The result is an easy-to-use and intuitive interface that uses a visual-based approach in creating a particle system in Maya. By following guidelines laid out by previous researchers in the field of HCI, the interface should be a less frustrating to use and more organized version of Maya's current interface.

Background: Biopacemaking is the attempt to replicate sinoatrial node (SAN)-like pacemaker activity in other areas of the heart by manipulating genes involved in pacemaking. Application of this could emulate the electronic pacemaker without the need for implantation of permanent hardware, or directly repair dysfunctional SAN tissue in human disease. We upregulated the transcription factors Tbx18, Tbx3 and the membrane ion exchanger NCX1 in bradycardic subsidiary atrial pacemaker (SAP) tissue which we used as a model of SAN dysfunction. We aimed to show that one or more of these gene targets could improve pacemaker function and alter the molecular character of SAP tissue and thus could potentially be used for the repair of dysfunctional SAN tissue. Methods: SAP tissue was isolated from the right atria of rats and kept beating in culture at 37°C for 48 hours. Recombinant adenoviruses were injected into SAP preparations to upregulate Tbx18, Tbx3 and NCX1 individually. Beating rate, overdrive suppression and pharmacological response to If blockade and β-adrenergic stimulation were measured along with molecular changes in pacemaker and atrial genes and proteins using RT-qPCR and immunohistochemistry. Results: Tbx18 upregulation significantly increased SAP beating rate after 48 hours of culture (a final rate of 141 ± 9 bpm in uninfected SAP tissue versus 215 ± 16 bpm in Ad-Tbx18 infected SAP tissue, p<0.01). It induced upregulation of HCN2 (p<0.01) and RYR2 (p<0.05), downregulation of HCN4 (p<0.05) and no change HCN1, Tbx3, Kv1.5, Kir2.1, Nav1.5, NCX1, Cx43, Cx45, Cav1.2 or Cav3.1. There was also no change in overdrive suppression and no change in response to pharmacology. No increase in beating rate was seen with either Tbx3 or NCX1 upregulation. Tbx3 preparations induced downregulation of the atrial genes Kir2.1 (p<0.01) and Nav1.5 (p<0.05), along with HCN1 (p<0.05), HCN4 (p<0.01), Tbx18 (p<0.05) and NCX1 (p<0.01), upregulated Cx43 (p<0.05) and showed no change in Cx45, RYR2, Kv1.5. NCX1 preparations demonstrated reduced overdrive suppression (p<0.05). Conclusion: Tbx18 showed the most potential for biopacemaking in SAP tissue, however both Tbx3 and NCX1 could be applied as secondary targets to fine tune biopacemaker function. Future work would focus on applying these targets to dysfunctional SAN tissue in larger animals.

Introduction: Beat-to-beat variability in cycle length exists in spontaneously beating cardiac preparations of varying complexities from the level of the isolated whole heart to the single sinoatrial nodal cell (SANC). The nature of this variability is poorly characterised as are its fundamental physiological origins. Methods: Recordings of spontaneous electrical activity were made from hearts in vivo, during Langendorff-perfusion, and from single SANC. Heart rate variability (HRV) was calculated in the time- and frequency-domains at baseline and in response to pharmacological mediators that interfered with critical processes involved in automaticity (catecholamines, carbachol, ivabradine, zatebradine, ryanodine and thapsigargin). In addition, a novel 2D technique for imaging Ca2+ fluorescence in spontaneously beating, fluo4-AM loaded, patched single sinoatrial nodal cells was developed to investigate the biophysical behaviour of Ca2+ during pacemaking to see if variability in this was responsible for SANC HRV. Results: Under baseline, temperature-stable conditions, levels of HRV were greatest in vivo (human > rat). SANC exhibited slightly lower levels of HRV, whereas HRV levels expressed by Langendorff-perfused hearts were the least (rabbit > rat), although still comprised a significant proportion of the variability witnessed in vivo. Anaesthetising in vivo rabbits decreased HRV to levels similar to those seen in the Langendorff-perfused heart. HRV was decreased by catecholamines and by ryanodine/thapsigargin in the Langendorff heart. Conversely, HRV was increased by carbachol, ivabradine, zatebradine and ryanodine in SANC. Heart rate changes had a marked effect on levels of HRV. 2D Ca2+ imaging of SANC showed that diastolic local Ca2+ releases (LCRs) occurred earlier than previously thought, with early LCRs having characteristics that were distinct from later LCRs. Mean time of occurrence of all the LCRs within a given diastole closely predicted the duration of the cycle. The rate of restitution of the whole cell Ca2+ transient (used as a surrogate for the pumping function of SERCA) in turn closely predicted the mean time of occurrence of LCRs. Tight synchronisation of the electrical activity of the cell with the biophysical behaviour of Ca2+ appeared to predict shorter cycle lengths. Isoprenaline increased LCR amplitude, though did not increase LCR number, size or duration. Isoprenaline caused LCRs to occur earlier, and synchronised their occurrence and the rate of pumping of Ca2+ back into the sarcoplasmic reticulum. Finally, LCRs were found to preferentially recur in certain regions of the cell, dubbed hotspots. Isoprenaline favoured hotspot production. Conclusion: Whilst greatest in vivo, significant HRV exists in spontaneously beating cardiac preparations devoid of a functioning autonomic nervous system. Studies in SANC indicate that the origin of this is likely to be variability in release of LCRs from the SR via ryanodine receptors. This in turn is controlled by SR refilling kinetics via SR Ca2+ pumping. The coupled system of membrane- and Ca2+-pacemaker clocks are so heavily intertwined that myriad factors will come to bear on generating such variability, including the amount of Ca2+ available for pumping and the phosphorylation state of key proteins, to the extent that variability in no one process can take the credit for generating such HRV.

Breast cancer is the second leading cause of cancer-related death in women in the United States. Complications that lead to mortality of cancer patients are associated with tumor metastasis. Specifically, lymphatic metastasis in breast cancer patients strongly correlates with poor patient survival and this process is facilitated by the formation of new tumor lymphatic vessels termed lymphangiogenesis. Previously, our lab reported that lymphangiogenesis was promoted by a distinct subset of bone marrow (BM)-derived myeloid cells that co-express lymphatic-specific markers designated as myeloid-derived endothelial cell progenitors (M-LECPs). Furthermore, our lab has generated M-LECP in vitro from a mouse macrophage cell line (RAW264.7) by LPS stimulation. Taken together, these data suggest that chronically inflamed sites drive M-LECP differentiation and that these cells can contribute to the formation of new lymphatic vessels and promote lymph node metastasis. Evidence supporting this hypothesis was indicated by high levels of circulating M-LECP in peripheral blood of breast cancer patients but undetectable levels in healthy donors, cancer-free donors. Additionally, the generation of M-LECP was prompted through TLR4-signaling pathway, and de novo expression of VEGFR-3 and VEGF-C. This co-expression produces an autocrine loop essential for pro-lymphatic reprogramming in both primary human monocytes and the immature monocytic cell line, THP-1. Taken together, these data indicate the major regulatory role of TLR4 in inflammation-driven lymphangiogenesis involves the recruitment and differentiation of M-LECP, a process that may promote lymphatic metastasis.

Cardiovascular disease is a leading cause of death in developed countries, and places a huge demand on healthcare services and economies across the globe. In this thesis computational models of the rabbit and mouse whole heart were developed and used to investigate a variety of phenomena related to cardiac electrophysiology. In part I, a heterogeneous family of single cell models was developed for the rabbit ventricles. The models were incorporated into a 3D anatomical reconstruction, and subsequently used to study the relationship between ventricular heterogeneity and the electrocardiographic T-wave. It was found that, in order of significance, apico-basal, inter-ventricular and transmural heterogeneity had a lead-dependent effect on the T-wave of the 12-lead electrocardiogram. Subsequently, a detailed model of the rabbit whole heart was developed using image data from X-ray computed tomography, from which detailed anatomical structures were segmented and myocardial architecture determined. The developed 3D whole heart model exhibited physiological fibre structure and experimentally justified patterns of activation. In part II, a mathematical model of the mouse atrioventricular node was developed. The model was validated by its ability to show physiological pacemaking and response to ion channel blocking. The model was subsequently adapted to consider the heterogeneous nature of the atrioventricular node, and incorporated into a 2D simplistic tissue model of the whole heart. The developed model exhibited physiological atrioventricular conduction, and provided insights into the nature of dual-pathway electrophysiology and the role of the funny current. Finally, an optimisation study was carried out for contrast enhancement of X-ray computed tomography, specifically for imaging the mouse heart, the results of which may be used to facilitate future high-throughput imaging of cardiac tissue.

Thesis (MTech (Nursing))--Cape Peninsula University of Technology, 2011. / To determine the incidence, risk factors and the treatment of lymphedema after breast cancer treatment at the oncology unit of KATH, Kumasi, Ghana from 01 January 2005 to 31 December 2008. Descriptive retrospective survey was used. Using a data capture sheet, data was collected from the medical records of the breast cancer patients. Breast cancer and lymphedema-related variables were collected. Data was analyzed as descriptive statistics. Chi-square test was applied to determine whether or not two variables are independent variables. Among 313 patients treated for breast cancer between 2005 and 2008, 31 (9.9%) developed lymphedema after treatment. A chi-square test showed that axillary lymph node dissection was statistically a significant risk factor of lymphedema (Chi-square test value=7.055, P value=0.008). Radiation and late stage of breast cancer diagnosis may have contributed in development of lymphedema despite having P value> 0.05. Age, body mass index (BMI) and hypertension were also not associated with lymphedema.

A Mobile Ad hoc Network (MANET) consists of a set of communicating wireless mobile nodes or devices that do not have any form of fixed infrastructure or centralized authority. The security in MANET has become a significant and active topic within the research community. This is because of high demand in sharing streaming video and audio in various applications, one MANET could be setup quickly to facilitate communications in a hostile environment such as battlefield or emergency situation likes disaster rescue operation. In spite of the several attacks aimed at specific nodes in MANET that have been uncovered, some attacks involving multiple nodes still receive little attention. A reason behind this is because people make use of security mechanisms applicable to wired networks in MANET and overlook the security measures that apply to MANET. Furthermore, it may also have to do with the fact that no survey or taxonomy has been done to clarify the characteristics of different multiple node attacks. This thesis addresses the aforementioned gap by providing a proper definition and categorization of collaborative attacks against MANET from the various multiple node attacks found. Simulation using OPNET Modeler was used to investigate the performance impact of a collaborative blackhole attack on a mobile ad hoc network. Network throughput, packet delivery ratio and end-to-end delay are the performance metrics used in our result analysis. Based on the analyses of performance metrics made, we realised the consequences of a collaborative blackhole attack on MANET. In order to prevent or reduce these consequences, we also discuss a number of mitigation plans to counteract the different kinds of collaborative attacks. Keywords: MANET, Collaborative Attacks, Multiple Node, Blackhole. / Contact Information: Author(s): Cong Hoan Vu Address: Folkparksvägen 19:08, 372 40 Ronneby, Sweden. E-mail: vuconghoan@gmail.com Adeyinka Soneye Address: Polhemsgatan 27B, LGH 30, 371 40 Karlskrona, Sweden. E-mail: adso07@student.bth.se

I arbetet jämförs kommunikation i Ajax med kommunikation i Websockets som är en äldre respektive nyare teknik som används vid realtidsbaserade applikationer. Två applikationer skapas som används för att mäta bandbreddskonsumtion samt nätverksfördröjning beroende på parametrarna datastorlek och uppdateringsfrekvens, som i kombination förväntas påverka mätresultaten. Syftet är att hitta samband mellan parametrarna för att visa vid vilka typer av applikationer Websocket lönar sig bäst och därmed ge understöd för beslut om migration från den gamla tekniken Ajax till den nyare tekniken Websockets.Resultatet av arbetet visar att kommunikation med låg datastorlek per anrop leder till störst vinst med Websockets samt att Websockets oavsett datastorlek eller uppdateringsfrekvens är betydligt bättre än Ajax. För framtida arbete förväntas främst undersöka hur även antalet samtida uppkopplade användare kan påverka resultatet.