Francisella tularensis is a Gram-negative, zoonotic bacterium that causes tularemia in animals and humans. The two subspecies tularensis (Type A) and holarctica (Type B) are considered Tier I Select Agents due to the bioweapon potential of these subspecies. Type A strains, considered the more virulent of the subspecies, are highly infective producing respiratory tularemia with inhalation of as few as 10 cells. Due to classification as a Select Agent, a vast amount of F. tularensis research has occurred in the last two decades after the September 11th terrorism attack and the use of Bacillus anthracis spores in a biological attack on the United States Postal Services in 2001. This research has uncovered many of the various virulence factors of F. tularensis including an intracellular nature, the unique lipopolysaccharide produced, and a genetic pathogenicity island. This dissertation aims to further characterize outer surface antigens of F. tularensis subspecies in regards to virulence, biofilm formation, and role in vaccine development. In addition, this dissertation will also investigate the use of a novel vaccine delivery vehicle, alginate microencapsulation, in increasing the efficacy of these mutant strains. F. novicida is a subspecies of F. tularensis and usually classified as being non-encapsulated. However, F. novicida has a similar capsule glycosylation locus as F. tularensis and could produce a similar capsule-like complex that has previously been described for the F. tularensis LVS strain. I was able to isolate and characterize this CLC of F. novicida, which contained a heterogenous mixture of proteins and possible glycosylated proteins. A mutant with a multi-gene interruption within the glycosylation locus (F. novicidaΔ1212-1218) produced significantly less carbohydrate than the parent strain, was attenuated in the mouse model, and was partially protective when used to immunize mice against a virulent challenge. Biofilms of F. novicida were also characterized in regards to biofilm formation in various growth media and biofilm formation of strains lacking the O-antigen of the lipopolysaccharide (LPS). In general, F. novicida produced the greatest amount of biofilm in a brain heart infusion (BHI) broth, compared to other media. Loss of the O-antigen led to increased biofilm production when grown in BHI and decreased or similar biofilm production as the wildtype when grown in other media. This highlights the need to carefully select the growth medium when assessing biofilm formation of Francisella strains in the future. A final study of this dissertation characterized the use of alginate microspheres as a vaccine vehicle for an attenuated F. tularensis type A O-antigen deficient strain. O-antigen deficient strains of F. tularensis are highly attenuated in vivo and would be a safe choice for a vaccine candidate. However, these strains produce less than ideal protection against virulent challenge when used to immunize mice, possibly due to a lack of persistence in the host. In an attempt to increase persistence, we encapsulated an O-antigen deficient strain within sodium alginate microspheres and used those microspheres to immunize mice. The immunized mice produced a higher level of antibody response than mice immunized with a non-encapsulated version. However, this immunization only partially protected mice from a virulent challenge and did not match the protection afforded by the former Live Vaccine Strain (LVS). In part the deficiency in protection appears to be due to a lack of a robust cellular immune response in mice immunized with the alginate microspheres. In summary, this dissertation focuses on the various extracellular polysaccharides of F. tularensis: the glycosylation of CLC, the O-antigen, and the biofilm. Each polysaccharide plays a role in the virulence and pathogenesis of F. tularensis. Glycosylation of the CLC and the O-antigen are important virulence factors in mammalian disease, and mutants lacking either (not type A strains) are attenuated in the mouse model. Both also appear to play a role in the formation of the F. tularensis biofilm in a manner dependent on the environment or culture medium used. Each of these extracellular polysaccharides contribute to the lifecycle of Francisella. / Ph.D. / Francisella tularensis is a highly infectious bacterial pathogen that can cause disease in a wide array of animals and in humans. F. tularensis is also considered a potential weapon of bioterrorism and the development of an effective vaccine is a critical area of research. One strategy of developing a tularemia vaccine includes mutating a strain of F. tularensis to reduce expression of extracellular components that include polysaccharides. Strains that cannot express these components are usually unable to produce clinical signs in the host and may provide protection against fully virulent F. tularensis strains. The work presented in this dissertation will focus on characterizing the polysaccharide extracellular components of F. tularensis and developing a novel vaccine vehicle to increase protection from strains that do not cause disease.

The early discovery of gastrointestinal (GI) disorders can significantly decrease the fatality rate of severe afflictions. Video capsule endoscopy (VCE) is a technique that produces an eight hour long recording of the GI tract that needs to be manually reviewed. This has led to the demand for AI-based solutions, but unfortunately, the lack of labeled data has been a major obstacle. In 2020 the Kvasir-Capsule dataset was produced which is the largest labeled dataset of GI abnormalities to date, but challenges still exist.The dataset suffers from unbalanced and very similar data created from labeled video frames. To avoid specialization to the specific data the creators of the set constructed an official split which is encouraged to use for testing. This study evaluates the use of transfer learning, Data augmentation and binary classification to detect GI abnormalities. The performance of machine learning (ML) classification is explored, with and without official split-based testing. For the performance evaluation, a specific focus will be on achieving a low rate of false negatives. The proposition behind this is that the most important aspect of an automated detection system for GI abnormalities is a low miss rate of possible lethal abnormalities. The results from the controlled experiments conducted in this study clearly show the importance of using official split-based testing. The difference in performance between a model trained and tested on the same set and a model that uses official split-based testing is significant. This enforces that without the use of official split-based testing the model will not produce reliable and generalizable results. When using official split-based testing the performance is improved compared to the initial baseline that is presented with the Kvasir-Capsule set. Some experiments in the study produced results with as low as a 1.56% rate of false negatives but with the cost of lowered performance for the normal class.

無線膠囊內窺鏡（CE）是一種用於檢查整個胃腸道，尤其是小腸的無創技術。它極大地改善了許多小腸疾病的診斷和管理方式，如不明原因的消化道出血，克羅恩病，小腸腫瘤，息肉綜合征等。儘管膠囊內窺鏡有很好的臨床表現，但它仍然有一定的局限性。主要問題是每次檢查產生約50,000 幅低質量的圖像，對於醫生來說，評估如此大量的圖像是一項非常耗時、耗力的工作。 / 到目前為止，對於膠囊內窺鏡的分析和評估，學者們都把膠囊內窺鏡圖像視為單獨的，獨立的觀測對象。事實並非如此，因為圖像之間往往有顯著的重疊。特別是當膠囊內窺鏡在被小腸蠕動緩緩推動時，它可以捕捉同一病灶的多個視圖。我們的研究目的是使用所有可用的資訊，包括多幅圖像，研究對於膠囊內窺鏡的電腦輔助診斷（CAD）系統。 / 在這篇論文中，我們提出了一個嵌入分類器的多類隱馬爾可夫模型（HMM）的方案，它可以融合多幅相鄰圖像的時間資訊。由於膠囊內窺鏡圖像的品質比較低，我們首先進行預處理，以加強膠囊內窺鏡圖像，增加其對比度，消除噪聲。我們調查研究了多種圖像增強的方法，並調整了它們的參數使其適用於膠囊內窺鏡圖像。 / 對於基於單幅圖像的有監督的分類，AdaBoost 作為一個集成分類器來融合多個分類器，即本論文中的支持向量機（SVM），k-近鄰（k-NN），貝葉斯分類。在分類之前，我們提取和融合了顏色，邊緣和紋理特徵。 / 對於無線膠囊內窺鏡的視頻摘要，我們提出了有監督和無監督的兩類方法。對於有監督方法，我們提出了一個基於隱馬爾可夫模型的，靈活的，可擴展的框架，用於整合膠囊內窺鏡中連續圖像的時間資訊。它可以擴展到多類別，多特徵，多狀態。我們還提出了聯合隱馬爾可夫模型和並行隱馬爾可夫（PHMM）模型對系統進行改進，它們可以被看作是決策級的資訊融合。聯合隱馬爾可夫模型通過多層次的隱馬爾可夫模型，結合不同的資訊來源，對膠囊內窺鏡視頻進行分類和視頻摘要。 並行隱馬爾可夫模型採用貝葉斯推理，在決策時融合多個不同來源的資訊。對於無監督的方法，我們首先提出了一種基於顏色的特徵提取方法。在反色顏色空間中對亮度不變的色度不變矩用來表示膠囊內窺鏡圖像的顏色特徵。接著，我們又提出了一種基於輪廓元（Contourlet）變換的局部二元模式（LBP）作為紋理特徵。在特徵空間中，我們測量了相鄰圖像的距離，並把它視為一個位於二維平面上的開放輪廓上的點。 然後，我們採用一個無參數的關鍵點檢測方法檢測在視頻片段上的突變關鍵點。基於這些突變關鍵點，我們對膠囊內窺鏡視頻進行分割。最後，在每段被分割的視頻片段上，我們通過提取有代表性的關鍵幀來實現膠囊內窺鏡視頻摘要。我們分別用模擬和真實的病人數據進行實驗，對提出的方法進行驗證，結果表明了我們所提出的方案的有效性。它在實現自動評估膠囊內窺鏡圖像上具有很大的潛力。 / Wireless Capsule Endoscopy (CE) is a non-invasive technology to inspect the whole gastrointestinal (GI) tract, especially the small intestine. It has dramatically changed the way of diagnosis and management of many diseases of the small intestine, such as obscure gastrointestinal bleeding, Crohn’s disease, small bowel tumors, polyposis syndromes, etc. Despite its promising clinical findings, it still has some limitations. The main problem is that it requires manual assessment of approximately 50,000 low quality images per examination which is highly time-consuming and labor-intense. / CE analysis and assessment so far treated CE images as individual and independent observations. It is obviously not the case as there is often significant overlap among images. In particular, CE captures multiple views of the same anatomy as the capsule is slowly propelled by peristalsis. Our broader work aims to perform computer aided diagnosis (CAD) in endoscopy using all available information, including multiple images. / In this dissertation, a framework of multi-class Hidden Markov Models (HMM) embedded with statistical classifiers for combining information from multiple CE images is proposed. Due to the low quality of CE image, pre-processing is performed to enhance CE images by increasing the contrast and removing noises. Several image enhancement methods are investigated and customized for CE images. For frame-based supervised classification, AdaBoost is used as the ensemble classifier to combine multiple classifiers, i.e. support vector machine (SVM), k-nearest neighbor (k-NN), and Bayes classifier. Before classification, color, edge and texture features are extracted and fused. Finally, both supervised and unsupervised methods are proposed for CE study synopsis. For supervised method, a flexible and extensible framework based on HMM is developed to integrate temporal information in CE images. It can be extended to multi-class, multi-features, and multi-states. Improvements can be made by combined HMM and Parallel HMM (PHMM) which are introduced as decision-level fusion schemes. Combined HMM considers different sources via a multi-layer HMM model to perform classification and video synopsis. PHMM employs Bayesian inference to combine the recognition results at decision level. For unsupervised method, illumination-independent opponent color moment invariants and local binary pattern (LBP) based on Contourlet transform are explored as color and texture features, respectively. Pair-wise image dissimilarity is measured in the feature space and treated as points on an open contour in a 2-D plane. CE video is segmented based on sudden change points which are detected using a non-parametric key-point detection method. From each segment, representative frames are extracted to summarize the CE video. Validation results on simulated and real patient data show promising performance of the proposed framework. It has great potential to achieve automatic assessment for CE images. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhao, Qian. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 142-175). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.ii / Acknowledgments --- p.vii / List of Tables --- p.xiii / List of Figures --- p.xv / Chapter 1 --- The Relevance of Synopsis --- p.1 / Chapter 1.1 --- Problem Statement --- p.1 / Chapter 1.2 --- Application - Capsule Endoscopy Assessment --- p.4 / Chapter 1.3 --- Literature Review --- p.9 / Chapter 1.3.1 --- Methods Based on Frame Classification --- p.11 / Chapter 1.3.2 --- Methods Integrating Temporal Information --- p.14 / Chapter 1.4 --- Contributions --- p.19 / Chapter 1.5 --- Organization --- p.23 / Chapter 2 --- Preliminary --- p.25 / Chapter 2.1 --- Hidden Markov Model (HMM) --- p.25 / Chapter 2.2 --- Factorial HMM --- p.35 / Chapter 3 --- Temporal Integration in Capsule Endoscopy Image Analysis --- p.37 / Chapter 3.1 --- Pre-processing --- p.38 / Chapter 3.2 --- Feature Extraction --- p.43 / Chapter 3.3 --- Frame-based Supervised Classification --- p.47 / Chapter 3.3.1 --- Supervised Classification using Individual Frames --- p.47 / Chapter 3.3.2 --- Ensemble Learning Based on AdaBoost --- p.50 / Chapter 3.4 --- Sequence-based Supervised Classification --- p.52 / Chapter 3.5 --- Experiments --- p.58 / Chapter 3.5.1 --- Capsule Endoscopy Image Enhancement --- p.60 / Chapter 3.5.2 --- Frame-based Supervised Classification --- p.67 / Chapter 3.5.3 --- Image Sequence Classification --- p.68 / Chapter 3.6 --- Discussion --- p.80 / Chapter 3.7 --- Summary --- p.82 / Chapter 4 --- Capsule Endoscopy Study Synopsis --- p.98 / Chapter 4.1 --- Supervised Synopsis Using Statistical Models --- p.98 / Chapter 4.2 --- Unsupervised Synopsis via Representative Frame Extraction --- p.100 / Chapter 4.2.1 --- Feature Extraction --- p.100 / Chapter 4.2.2 --- Non-parametric Key-point Detection --- p.111 / Chapter 4.2.3 --- Representative Frame Extraction --- p.112 / Chapter 4.3 --- Experiments --- p.119 / Chapter 4.3.1 --- Supervised Synopsis Based on HMM --- p.119 / Chapter 4.3.2 --- Unsupervised Synopsis --- p.125 / Chapter 4.4 --- Discussion --- p.132 / Chapter 4.5 --- Summary --- p.133 / Chapter 5 --- Conclusions and Future Work --- p.138 / Chapter 5.1 --- Conclusions --- p.138 / Chapter 5.2 --- Future Work --- p.141 / Bibliography --- p.142

A feature extraction approach based on color is firstly proposed. Exploiting color histogram of an image, we can obtain distribution of different colors in images. Then we employ minimum distance classifier based on a new distance criterion to judge status of regions. In this section, we also validate benefits of WCE image enhancement to the proposed CAD system. / Finally, we propose a new approach of chrominance moment as another kind of feature to discriminate normal regions from abnormal regions, which makes full use of Tchebichef polynomials and HSI color space. This new feature extraction scheme preserves illumination invariance without numerical approximation. / In conclusion, this thesis investigates several major and challenging problems such as WCE images enhancement and feature extractions in CAD for WCE images, and proposes several novel schemes to solve those problems. Extensive experiments are reported to demonstrate effectiveness of the proposed algorithms. / Next, we investigate automatic diseases detection for WCE images to partially solve the second problem. In this part we explore different features that are suitable for detection of diseases from three viewpoints, i.e., color, texture and chromaticity, because clinicians mainly use these clues to diagnose. At the same time, we introduce their corresponding classifiers. / We further advance a new texture feature extraction method, curvelet based local binary pattern, to detect abnormal regions in WCE images. This method takes advantage of curvelet transform and local binary pattern to describe textural features of WCE images. / Wireless capsule endoscopy (WCE) is a state-of-the-art technology to diagnose gastrointestinal (GI) tract diseases without invasiveness. However, there exist two major problems concerning WCE images. One problem is that many images for diagnosis have rather low contrast and are noisy, which causes difficulties to diagnosis and also to computer-aided detection, so it is necessary to enhance these images. The other one is that the viewing process of video data per examination is very time consuming because of the great amount of video data. If we can use computerized methods to help the physicians detect some abnormal regions in WCE images, it will certainly reduce the burden of physicians. Focusing on these two goals, this thesis mainly studies some main challenging problems in computer-aided diagnosis (CAD) system for WCE images. To solve the first problem, we put forward an adaptive curvature strength diffusion method to enhance WCE images. Based on local characteristics analysis of WCE images, we propose a new concept of curvature strength. Then, we employ curvature strength diffusion to enhance WCE images with an adaptive choice of conductance parameter. Finally, we extend the curvature strength diffusion to color space since WCE images are color images. / Li, Baopu. / Adviser: Max Q. H. Meng. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3640. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 126-150). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Les capsules, formées d’une goutte protégée par une membrane élastique, sont très présentes naturellement et dans diverses applications industrielles, mais peu d’études ont exploré les phénomènes transitoires de leur relaxation. L’objectif est d’étudier l’influence de l’inertie et du confinement sur la relaxation d’une capsule sphérique (1) pré-déformée en ellipsoïde et relâchée dans un canal carré où le fluide est au repos, (2) sous écoulement dans un canal carré à expansion soudaine (‘marche’). La capsule est modélisée comme un fluide Newtonien dans une membrane hyper-élastique sans épaisseur ni viscosité, et simulée en couplant les méthodes Volumes Finis - Eléments Finis - frontières immergées. Sa relaxation dans un fluide au repos comporte 3 phases : amorçage du mouvement du fluide, phases rapide puis lente de rétraction de la membrane. Trois régimes existent selon le rapport de confinement et le rapport des nombres de Reynolds et capillaire : amortissements pur, critique ou oscillant. Un modèle de Kelvin-Voigt inertiel est proposé pour prédire les temps de réponse et aussi appliqué à une capsule en écoulement dans le canal microfluidique avec marche. La comparaison aux simulations 3D montre sa pertinence aux temps courts de la relaxation. Ces travaux ouvrent la voie à l’étude d’écoulements transitoires de capsules confinées dans des systèmes microfluidiques complexes. / Capsules, made of a drop protected by an elastic membrane, are widly present in nature and in diverse industrial applications, but few studies have explored the transient phenomena governing their relaxation. The objective of the PhD is to study the influence of inertia and confinement on the relaxation of a spherical capsule (1) pre-deformed into an ellipsoid and released in a square channel where the fluid is quiescent, (2) flowing in a square channel with a sudden expansion (‘step’). The capsule is modeled as a Newtonian fluid in a hyperelastic membrane without thickness or viscosity and is simulated coupling the Finite Volume - Finite Element - Immersed Boundary Methods. Its relaxation in a quiescent fluid exhibits three phases: the initiation of the fluid motion, the rapid and then slow retraction phases of the membrane. Three regimes exist depending on the confinement ratio and the Reynolds to capillary number ratio: pure, critical or oscillating damping. A Kelvin-Voigt inertial model is proposed to predict the response time constants and also applied to a capsule flowing in the microfluidic channel with a step. The comparison to 3D simulations shows its relevance at short relaxation times. This work paves the way to the study of transient flows of capsules confined in microfluidic devices.

La pose d’implants mammaires est l’une des interventions chirurgicales les plus courantes en chirurgie plastique. Elle permet de reconstruire un sein après une mastectomie ou d’augmenter son volume pour améliorer le décolleté et la forme du sein. Depuis leur introduction dans les années 1960, les implants mammaires siliconés ont fait l’objet de multiples controverses et leur innocuité a pendant longtemps été questionnée. Ces dispositifs médicaux sont considérés comme sûr par la FDA mais ne sont pas pour autant exempts de complications. L’une d’entre elles, le silicone bleeding, se traduit par la migration de particules de silicone depuis le gel de l’implant vers la capsule péri-prothétique. Ces particules de silicone représentent une source potentielle d’inflammation chronique autour des implants mammaires dont les conséquences à long terme sur la santé des patientes ne sont pas claires. Bien que cette complication soit objectivée depuis les années 1970, il existe à l’heure actuelle peu de données sur la quantité de silicone qui est susceptible de migrer des implants mammaires. L’objectif principal de notre étude a été de quantifier les particules de silicone dans les capsules péri-prothétiques des implants mammaires en décrivant une nouvelle méthode de quantification basée sur une analyse histologique approfondie des spécimens de capsule. Les résultats préliminaires de notre étude ont permis de démontrer que des millions de particules de silicone peuvent diffuser dans la capsule péri-prothétique des implants mammaires siliconés et que l’ampleur du phénomène à tendance à croître avec la durée d’implantation. / The placement of breast implants is one of the most common surgical procedures in the field of plastic surgery. Although these medical devices are considered safe by the FDA, their use is not free of complications. One of these complications is silicone particle bleeding, or the migration of silicone particles from the breast implant into the peri-prosthetic capsule. These particles represent a potential source of chronic inflammation around breast implants, with unclear long-term consequences for patient health. Although this complication has been observed since the 1970s, there is currently very little data on the amount of silicone that is likely to migrate from breast implants. The primary objective of this study was to quantify silicone particles in the peri-prosthetic capsules of breast implants by describing a new method of quantification based on a thorough histological analysis of capsule specimens. Preliminary results of our study have shown that millions of silicone particles can diffuse into the periprosthetic capsule of silicone breast implants and that the amount of silicone particles tends to increase with the duration of implantation.

La prévalence de Streptococcus suis, notamment du sérotype 2, à l’échelle mondiale pose de grands problèmes à l’industrie porcine ainsi qu’à la santé publique. La compréhension des mécanismes immunitaires permettant alors de lutter contre cette bactérie devient un atout majeur dans le développement des vaccins. S. suis dispose cependant d’un puissant arsenal pour contrer ces mécanismes. Enveloppé d’une capsule polysaccharidique (CPS), cette bactérie résiste à la phagocytose, à moins que certaines cellules soient en mesure de produire des anticorps opsonisants. Par chance, au sein de la rate, en périphérie du follicule, une zone nommée la « zone marginale » regroupe des lymphocytes B spécialisés dans la réponse aux bactéries encapsulées et aux antigènes polysaccharidiques. Ceci sans l’intervention des lymphocytes T auxiliaires, contrairement aux lymphocytes B se trouvant à l’intérieur du follicule, qui interviennent dans une réponse plus dirigée contre des antigènes protéiques. L’objectif général de ce mémoire est donc l’étude de la réponse anticorps dite « extrafolliculaire » que les LB-MZ sont suspectés d’orchestrer lors d’une infection à S. suis. En premier lieu nous avons déterminé la cinétique de différentiation en plasmocytes des LB-MZ (LB-MZ) lors de l’infection par S. suis. Puis nous avons étudié la fonctionnalité et le type d’anticorps produits par ces LB-MZ. Les présents travaux ont démontré toute l’importance des LB-MZ dans l’élimination de la bactérie ou dans le ralentissement de sa dissémination systémique durant les premiers stades de l’infection, notamment grâce à un environnement propice à la différenciation en plasmocytes. Les principaux anticorps produits à cet effet étaient de classe IgM et dirigés contre des antigènes de la CPS. Nos résultats éclairent un peu plus la voie, et permettent d’imaginer des options pour le développement des vaccins qui activeraient spécifiquement cette réponse extrafolliculaire efficace. / The worldwide prevalence of Streptococcus suis, particularly serotype 2, poses major problems for the pig industry and public health. Understanding the immune mechanisms involved in combating this bacterium is becoming a major asset in the development of vaccines. However, S. suis has a powerful arsenal at its disposal to counter these mechanisms. Enveloped in a polysaccharide capsule (CPS), this bacterium resists phagocytosis unless certain cells can produce opsonising antibodies. Fortunately, within the spleen, at the periphery of the follicle, a zone known as the "marginal zone" contains B lymphocytes specialised in responding to encapsulated bacteria and polysaccharide antigens. This is without the intervention of T helper lymphocytes, unlike the B lymphocytes inside the follicle, which are involved in a response more directed against protein antigens. The general objective of this thesis is therefore to study the so-called 'extrafollicular' antibody response that LB-MZ are thought to orchestrate during S. suis infection. We first determined the kinetics of LB-MZ differentiation into plasma cells during S. suis infection. We then studied the functionality and type of antibodies produced by these LB-MZs. This work has demonstrated the importance of LB-MZ in eliminating the bacterium or slowing down its systemic dissemination during the early stages of infection, thanks to an environment conducive to differentiation into plasma cells. The main antibodies produced for this purpose were IgM class antibodies directed against CPS antigens. Our results shed a little more light on the pathway, and allow us to imagine options for the development of vaccines that would specifically activate this effective extrafollicular response.

The idea for this paper resulted out of a curiosity for minimalist lifestyle concepts, namely capsule closets and the missing research about this topic as well as the importance of this concept for the society, the environment and the future of the fashion and textile industry. The study describes a phenomenological study in which the researcher explored participants’ lived experiences with capsule closets in order to provide a better understanding of the capsule closet experience. Fixed-interval diaries and semi-structured in-depth interviews with five women were conducted. Using descriptive phenomenological analysis, the researcher identified seven essential themes representing the lived experiences found in participants’ experience with capsule closets: 1) Feeling excited, enthusiastic and determined; 2) Feeling relived and satisfied; 3) Experiencing struggles and challenges; 4) Feelings of guilt and regret; 5) Feeling limited, bored and less creative; 6) Feelings of accomplishment and proudness; 7) Learning experience. These findings both support and contribute to existing literature related to this topic and provide new insights and add new aspects to the knowledge of the capsule closet experience.

Vibrio vulnificus are marine bacteria causing fatal septicemia through wound infections or consumption of contaminated seafood. V. vulnificus is an excellent model for the study of surface polysaccharides, as it is capable of synthesizing capsular polysaccharide (CPS), lipopolysaccharide (LPS) and exopolysaccharide (EPS). V. vulnificus strains exhibit a multitude of carbotypes that evolve through unknown mechanisms. CPS is a confirmed virulence factor, but the genetics of its biosynthesis are unknown. The main objective of these experiments was to gain insight into the biosynthesis, regulation and evolution of ATCC 27562 outer surface polysaccharides. A miniTn10 transposon (Tn) system was used for mutagenesis and single insertions were confirmed through Southern analysis. A novel 25 kb CPS biosynthesis locus was identified through sequencing of regions surrounding Tn insertions; a region encoding putative LPS core biosynthetic functions was identified adjacent to the CPS cluster. The CPS locus contained features of O-antigen biosynthetic loci and was unusual in carrying characteristics of both group I and IV capsular biosynthetic loci. Mutations in this region resulted in elimination of CPS and LPS, and both were shown to be dependent on the activity of the polymerase Wzy. Evidence is presented here supporting horizontal transfer (HT) as a contributor to V. vulnificus CPS evolution. CPS regions of V. vulnificus 27562, YJ016 and CMCP6 contain strain specific genes surrounded by conserved regions, suggestive of HT. Moreover, a CPS locus virtually identical to that of 27562 was discovered in Shewanella putrefaciens strain 200. 27562 CPS is distinctive as it contains N-acetylmuramic acid. Genes encoding murA and murB activities were identified within the cluster and shown to be functionally redundant, supporting HT acquisition of this region. A screen of V. vulnificus gDNA library using CPS biosynthesis and transport mutants identified a cyclic diguanylate cyclase, dcpA. dcpA-mediated increase in cyclic diguanylate lead to EPS production, rugosity phenotypes and enhanced biofilm formation. Interestingly, virulence and motility were not affected suggesting complexity of cyclic diguanylate regulation in V. vulnificus, supported by the large number of cyclic diguanylate related proteins in Vulnificus strains.

Background: The ligaments in coherence with the capsule of the hip joint are known to contribute to hip stability. Nevertheless, the contribution of the mechanical properties of the ligaments and gender- or side-specific differences are still not completely clear. To date, comparisons of the hip capsule ligaments to other tissues stabilizing the pelvis and hip joint, e.g. the iliotibial tract, were not performed. Materials & Methods: Hip capsule ligaments were obtained from 17 human cadavers (9 females, 7 males, 13 left and 8 right sides, mean age 83.65 ± 10.54 years). 18 iliofemoral, 9 ischiofemoral and 17 pubofemoral ligaments were prepared. Uniaxial stress-strain properties were obtained from the load-deformation curves before the secant elastic modulus was computed. Strain, elastic modulus and cross sections were compared. Results: Strain and elastic modulus revealed no significant differences between the iliofemoral (strain 129.8 ± 11.1%, elastic modulus 48.8 ± 21.4 N/mm2), ischiofemoral (strain 128.7 ± 13.7%, elastic modulus 37.5 ± 20.4 N/mm2) and pubofemoral (strain 133.2 ± 23.7%, elastic modulus 49.0 ± 32.1 N/mm2) ligaments. The iliofemoral ligament (53.5 ± 15.1 mm2) yielded a significantly higher cross section compared to the ischiofemoral (19.2 ± 13.2 mm2) and pubofemoral (15.2 ± 7.2 mm2) ligament. No significant gender- or side-specific differences were determined. A comparison to the published data on the iliotibial tract revealed lower elasticity and less variation in the ligaments of the hip joint.