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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Luna Stain: A Simple and Cost-Effective Diagnostic Tool Helps in Detecting Eosinophilic Granules Deposition of Flame Figures and Aids in Diagnosing Eosinophilic Cellulitis “Wells Syndrome”

Mejbel, Haider A., Preiszner, Johanna, Shurbaji, M. Salah, Leicht, Stuart S., Youngberg, George A. 01 January 2020 (has links)
We report a rare case of Wells syndrome in which a 61-year-old Caucasian male presented with three distinct skin lesions including a cutaneous bulla, an erythematous plaque, and a linear streak located on the patient’s left anterior thigh, left dorsal wrist, and left anterior forearm, respectively. Histologic examination revealed diffuse and interstitial eosinophilic infiltrate admixed with lymphocytes and macrophages that predominantly involve the dermis. Nodular aggregates of eosinophils surrounding dermal collagen fibers suggestive of ‘flame figures’ were identified. Luna histochemical stain was used and highlighted the deposition of eosinophilic granules over the collagen bundles confirming the presence of flame figures. Laboratory workup revealed peripheral eosinophilia, but a comprehensive clinical evaluation failed to reveal a systemic disease and ultimately the diagnosis of eosinophilic cellulitis ‘Wells Syndrome’ was rendered. After a short course of immunosuppressive therapy, the patient experienced a complete resolution of the skin lesions on his last follow-up visit several weeks from the initial diagnosis. This case highlights the various clinical forms that Wells syndrome may present with and may serve as a good example for the use of Luna stain as a simple and cost-effective diagnostic tool that can help to arrive at the accurate diagnosis and inform therapy.
22

Evaluation of economics and management in Mid-South soybean production

Turner, Richard 07 August 2020 (has links)
Two studies were conducted from 2017 – 2019 at Stoneville, MS the first was to determine optimum seeding rates on single and twin row configuration during both late and early planting dates. The second study was to compare two row configurations with two planting populations (whole plot) but add management strategies (subplots) within each whole plot. From this data, yield optimization could be reached within each system that likely encompasses everything a producer in the Mississippi Delta could encounter during a growing season. Soybean seed from this data was analyzed for protein, oil, and fatty acid composition to determine which systems produce greater seed quality in terms of seed composition. Normal (non-symptomatic) and seed visually infected with purple seed stain (PSS) were compared to determine how infected soybean seed compared to normal soybean seed. Both seed (infected and non-symptomatic) were compared by measuring seed composition, germination, and vigor. During 2018 and 2019 at Verona, MS the same whole plot with subplot test was used but at this location under rained conditions. Soybean grown under rained conditions is a common practice in that particular region of the state (Northeast) so treatments were designed to be useful to producers in that area.
23

Physiological, ecological and environmental factors that predispose trees, stands and landscapes to infestation by tree-killing Dendroctonus beetles

Goodsman, Devin W. Unknown Date
No description available.
24

Nanofluidique de solutions polymériques appliquées à la synthèse in situ d'oligosaccharides / L'auteur n'a pas fourni de titre en anglais

Rolland, David 20 January 2012 (has links)
Les biopuces connaissent un grand essor depuis quelques années avec des applications possibles pour l’ADN, les protéines et les oligosaccharides. Une puce à oligosaccharides présente des difficultés par rapport à une puce à ADN notamment par les contraintes en température et il existe moins de travaux dans ce domaine. Ce travail est donc consacré à l’étude d’une puce à oligosaccharide, par synthèse supportée et par masquage avec un film de polymère. Le procédé de fabrications est particulièrement détaillé.Nous étudions tout d’abord expérimentalement la formation d’un film de polymère obtenu par évaporation d’une goutte de solution polymérique sur une surface structurée chimiquement(zone de mouillabilité différente) en suivant son évolution transitoire. Nous montrons que ce type de surface hétérogène est particulièrement adapté pour la fabrication de biopuces.D’autre part, nous réalisons un modèle numérique de l’évaporation d’une goutte de solution polymérique sur une surface chauffée à partir de la méthode de la lubrification et d’un modèle de « hauteur de résine ». Les résultats expérimentaux et de simulation numérique sont comparés et montrent un bon accord qualitatif sur la forme des films de polymères résultant de l’évaporation.Dans ce travail, la synthèse supportée de biopuces à oligosaccharide est menée à bien en utilisant des polymères et des surfaces judicieusement choisies. En particulier, la technique de masquage par film de polymère se révèle être très bien adaptée pour protéger les oligomères à la fois à hautes et à très basses températures. / Biochips are experiencing recently a great success with possible applications for DNA,proteins and oligosaccharides. An oligosaccharide chip presents difficulties compared to aDNA chip because of the many temperature constraints and less work has been performed inthis area. This work is devoted to the study of a oligosaccharide chip fabricated par supportedsynthesis and protected with a polymer film. The manufacturing process is particularlydetailed.We first examine experimentally the formation of a polymer film obtained by evaporation of adrop of polymer solution on a chemically structured surface (zone of different wettability) byfollowing its transient evolution. We show that this type of heterogeneous surface isparticularly suitable for manufacturing biochips. On the other hand, we propose a numericalmodel of the evaporation of a drop of polymer solution on a heated surface using thelubrication method and a “height of resin”. The experimental results and numericalsimulations are compared and show good qualitative agreement on the shape of the polymerfilms obtained after evaporation.In this work, the supported synthesis of oligosaccharide microarrays was carried out usingpolymers and surfaces which have been carefully chosen in preliminary testing. In particular,the masking technique using polymer film turns out to be highly suitable for protectingoligomers at both high and very low temperatures.
25

Multi-stain cancer detection in histological whole-slide-images of breast cancer resection specimen from female primary breast cancer patients / Detektion av cancer i histologiska helbilder med multipla infärgningar av bröstcancersektionsprover från kvinnliga patienter med primär bröstcancer

Sartor, Viktoria January 2024 (has links)
Breast cancer continues to be a major cause of mortality among women. In recent years, machine learning has emerged as a potential tool in detecting and grading cancer. Using machine learning techniques in computational pathology has the potential to improve precision medicine, enabling more personalized and more accurate treatment plans. The machine learning models can even detect structures that cannot be seen with human eyes. The first step is often to identify tissue areas with cancerous cells using machine learning models. Those models often rely solely on Haematoxylin and Eosin slides for training due to the time-consuming and costly nature of annotations by pathologists. Because of that, valuable information for training might be lost since some cancerous cells are more visible in the immunohistochemistry slides. In this thesis, Haematoxylin and Eosin slide annotations are registered to immunohistochemistry slides for training singlestain and multi-stain models. The registration of the annotations is not straightforward since the tissue of the slides is not necessarily from consecutive cuts, and they are sometimes applied to the slide at different angles. An algorithm evaluated during the ACROBAT challenge was used to register the slides. Using the transferred annotations, individual models are trained for each stain (K167, HER2, PGR, ER). Of the single-stain model, the HER2 stain model is showing the most promising results. As a second step, a multistain model is trained using all stains. The multi-stain model performs equally well as the single-stain models specializing in individual stains. This shows that there is no need to train specialized single-stain models. Thus being able to train one model for four different stains makes it possible to detect cancer in whole slide images stained with one of those four stains without the need to train a specialized model and only needing annotations in one stain. While the multi-stain model is a nice addition this thesis shows that it is possible to reuse annotations, which reduces the amount of manual labour from pathologists and allows for training models on immunohistochemistry slides with only having annotations from one stain. / Bröstcancer fortsätter att vara en vanlig orsak till dödlighet bland kvinnor. På senare år har maskininlärning visat sig vara ett värdefullt verktyg för att upptäcka och gradera cancer. Att använda maskininlärningstekniker inom beräkningspatologi har potential att förbättra precisionsmedicinen och möjliggöra mer individanpassade och exakta behandlingsplaner. Maskininlärningsmodellerna kan till och med upptäcka strukturer som inte kan ses med mänskliga ögon. Det första steget är ofta att identifiera vävnadsområden med cancerceller med hjälp av maskininlärningsmodeller. Dessa modeller är ofta helt beroende av hematoxylin- och eosin-slidebilder för träning eftersom det är tidsödande och kostsamt för patologer att göra annoteringar. På grund av detta kan värdefull information för träning gå förlorad eftersom vissa cancerceller är mer synliga på immunohistokemiska objektglas. I den här avhandlingen registreras annoteringar från objektglas med hematoxylin och eosin på immunohistokemiska objektglas för träning av modeller med en och flera infärgningar. Registreringen av annoteringarna är inte okomplicerad eftersom vävnaden på objektglasen inte nödvändigtvis kommer från på varandra följande snitt, och de appliceras ibland på objektglaset i olika vinklar. En algoritm som utvecklades under ACROBAT-utmaningen användes för att registrera bilderna. Med hjälp av de registrerade objektglasen tränas individuella modeller för varje infärgning (K167, HER2, PGR, ER). Av modellerna för enstaka infärgningar visar modellen för HER2-infärgning de mest lovande resultaten. I ett andra steg tränas en modell med flera infärgningar med hjälp av alla infärgningar. Multi-stain-modellen presterar lika bra som single-stain-modellerna som är specialiserade på enskilda infärgningar. Detta visar att det inte finns något behov av att träna specialiserade modeller för enstaka infärgningar. Att kunna träna en modell för fyra olika färgämnen gör det alltså möjligt att upptäcka cancer i hela objektglasbilder som färgats med ett av dessa fyra färgämnen utan att behöva träna en specialiserad modell och utan att behöva göra annoteringar. Möjligheten att endast använda en modell för att förutsäga fyra olika immunohistokemiska helbilder minskade datorkostnaderna för träning och underhåll av modellen.
26

Automated Tissue Image Analysis Using Pattern Recognition

Azar, Jimmy January 2014 (has links)
Automated tissue image analysis aims to develop algorithms for a variety of histological applications. This has important implications in the diagnostic grading of cancer such as in breast and prostate tissue, as well as in the quantification of prognostic and predictive biomarkers that may help assess the risk of recurrence and the responsiveness of tumors to endocrine therapy. In this thesis, we use pattern recognition and image analysis techniques to solve several problems relating to histopathology and immunohistochemistry applications. In particular, we present a new method for the detection and localization of tissue microarray cores in an automated manner and compare it against conventional approaches. We also present an unsupervised method for color decomposition based on modeling the image formation process while taking into account acquisition noise. The method is unsupervised and is able to overcome the limitation of specifying absorption spectra for the stains that require separation. This is done by estimating reference colors through fitting a Gaussian mixture model trained using expectation-maximization. Another important factor in histopathology is the choice of stain, though it often goes unnoticed. Stain color combinations determine the extent of overlap between chromaticity clusters in color space, and this intrinsic overlap sets a main limitation on the performance of classification methods, regardless of their nature or complexity. In this thesis, we present a framework for optimizing the selection of histological stains in a manner that is aligned with the final objective of automation, rather than visual analysis. Immunohistochemistry can facilitate the quantification of biomarkers such as estrogen, progesterone, and the human epidermal growth factor 2 receptors, in addition to Ki-67 proteins that are associated with cell growth and proliferation. As an application, we propose a method for the identification of paired antibodies based on correlating probability maps of immunostaining patterns across adjacent tissue sections. Finally, we present a new feature descriptor for characterizing glandular structure and tissue architecture, which form an important component of Gleason and tubule-based Elston grading. The method is based on defining shape-preserving, neighborhood annuli around lumen regions and gathering quantitative and spatial data concerning the various tissue-types.
27

Assessing the effect of pretreatment on cellulose accessibility for cellulosic biofuels production

Meng, Xianzhi 07 January 2016 (has links)
Biomass recalcitrance has been recognized as one of the major barriers that hided the cost-effective conversion of lignocellulosic biomass to bioethanol, therefore the current bioconversion process require an essential step known as pretreatment to increase the cellulose accessibility. This thesis provides information about changes in cellulose accessibility upon different pretreatments, along with how these pretreatments alter the chemical and physical structures of biomass, will be extremely helpful to further optimize the current pretreatment process. Multiple promising analytical techniques including Simons’ stain, NMR cryoporometry, relaxometry, mercury porosimetry was introduced and successfully applied on pretreated biomass samples to characterize the cellulose accessible surface area and biomass porosity. Different pretreatments increase cellulose accessibility through different mechanisms to different extent. Dilute acid pretreatment is more effective than steam explosion in terms of increasing accessible surface area of cellulose as reflected by Simons’ stain and NMR cryoporometry, while NMR relaxometry suggested steam explosion is more effective at pore expansion for the cell wall water pools detected by changes in NMR relaxation time. Alkaline pretreatment decreased cellulose degree of polymerization, cellulose crystallinity, lignin content and subsequently increased cellulose accessibility, with sodium hydroxide pretreatment proved to be much more effective compared lime or soaking in ammonia pretreatment. Delignification through alkaline-based pretreatment is found less effective than removal of hemicellulose using acid in terms of cellulose accessibility increase. Lignin didn’t directly dictate cellulose accessibility but rather restricted xylan accessibility which in turn controls the access of cellulase to cellulose. Pore size distribution analysis based on mercury porosimetry also indicated that the most fundamental barrier in terms of biomass porosity scale for efficient enzymatic hydrolysis is the nano-pore space formed between coated microfibrils, despite some of the porous architecture such as cell lumen and pit could be severely destroyed after pretreatment. The action of cellulase on the characteristics of cellulosic fractions obtained from pretreated biomass was also investigated. Cellulose accessibility was found to increase at the beginning of hydrolysis, and after reaching a maximum value then starting to decrease. Enzymatic hydrolysis resulted in a rapid decrease in the cellulose degree of polymerization then gradually leveled off, suggesting the existence of a synergistic action of endo- and exo-glucanases that contribute to the occurrence of a peeling off type mechanism.
28

Estudo Comparativo das t?cnicas de Imunofluoresc?ncia Direta, Imunofluoresc?ncia Indireta e Colora??o de Sellers em amostra de tecido nervoso de c?es e de animais silvestres para o diagn?stico da cinomose. / Comparative study of the techniques of Direct Immunofluorescence, Indirect Immunofluorescence and Stain Sellers in samples of nervous tissue of dogs and wild animals for diagnostic of the canine distemper

Barreto, Michelle Gomes 27 July 2006 (has links)
Made available in DSpace on 2016-04-28T20:17:24Z (GMT). No. of bitstreams: 1 2006-Michelle Gomes Barreto.pdf: 634856 bytes, checksum: 61550da2cbc0a0c4fbc8b6781fe93da0 (MD5) Previous issue date: 2006-07-27 / It was performed a study comparative in the diagnostic of the canine distemper through techniques of Direct Immunofluorescence (IFD), Indirect Immunofluorescence (IFI) and Stain Sellers in samples of nervous tissue of dogs and wild animals that died with suspicion clinical of the viruse. Were utilized 118 samples of central nervous system (SNC) of domestic dogs and 3 wild animals, 2 skunks and 1 monkey, utilizing Ammon?s horn (CA), cerebellum (CB) and brain stem (TE). The TE was the region of larger percentage of positive, following of CA. The comparation between Stain Sellers and IFD, this last demonstrated a large sensitive. The IFI observed what to the realization of the technique was necessary the utilization of fresh materials. The utilization of the 117 samples in conditions of autolysis presented negative result. However 1 sample not autolysate, it was result positive in the 3 brain regions (CA, CB, TE). It was not possible the comparative with the technique of IFI, because in the work the technique alone was possible in materials conserved, with the advantage of a read more easy. In the work was detected also canine distemper in a skunk through technique of IFD. / Foi realizado um estudo comparativo do diagn?stico da cinomose pelas t?cnicas de Imunofluoresc?ncia Direta (IFD), Imunofluoresc?ncia Indireta (IFI) e Colora??o de Sellers em amostras de tecido nervoso de c?es e de animais silvestres que morreram com suspeita cl?nica da virose. Foram utilizados 118 amostras de Sistema nervoso central (SNC) de c?es dom?sticos e de 3 animais silvestres , dois gamb?s e um mico, utilizando-se Corno de Ammon (CA), Cerebelo (CB) e Tronco Encef?lico (TE). O TE foi ? regi?o de maior porcentagem de positivos, seguido do CA. A compara??o entre a Colora??o de Sellers, e a IFD, revelou uma maior sensibilidade nesta ?ltima. Na IFI, observamos que para a realiza??o da t?cnica torna-se necess?rio ? utiliza??o de material fresco. Tendo em vista a utiliza??o das 117 amostras em estado de aut?lise apresentaram resultados negativos e apenas 1 n?o autolisado, teve seu resultado positivo nas 3 regi?es cerebrais (CA, CB e TE). N?o foi poss?vel a compara??o com a t?cnica de IFI, porque nesse trabalho, a t?cnica s? foi poss?vel em materiais conservados, com a vantagem de uma leitura mais f?cil. Nesse trabalho foi detectado tamb?m cinomose em um gamb? pela t?cnica de IFD.
29

Simulation of thermal stresses in a disc brake

Tao, Jiyue, Aziz, Asnaf January 2012 (has links)
The heat flux produced from the friction between a disc and pad system leads to a high temperature which causes thermal stresses in the disc and after a number of repeated braking cycles, cracks might be initiated. The finite element analysis (FEA) is performed to determine the temperatures profile in the disc and to analyze the stresses for the repeated braking, which could be used to calculate the fatigue life of a disc.Sequentially coupled approach is used for thermo-mechanical problem and the problem is divided into two parts, heat analysis and thermal stress analysis. The heat analysis is obtained by including frictional heat and adopting an Eulerian approach. The heat analysis is conducted by using Abaqus and the toolbox developed by Niclas Strömberg. The thermal stress analysis, which is the main focus of this thesis, is followed using Abaqus. The plasticity theory as background for stress analysis is discussed in detail. The rate independent elasto-plastic plasticity is used in the stress analysis. Temperature independent material properties are considered throughout the thesis work.Isotropic, kinematic and combined hardening models are analyzed for simple 2D academic models for different types of cyclic loads. A benchmark disc and pad model, which is less complicated than the real disc-pad model, is also studied. The linear kinematic hardening model with rate independent elastic-plastic plasticity is used for benchmark and real disc-pad model. The results of the benchmark model and the real model are observed to be similar in terms of plasticity theory.
30

Investigation of blood dynamics : surface flow and droplet stain morphology on fabrics

Nik Mohamed, Nik Elena January 2009 (has links)
This thesis is divided into two parts, each of which examines aspects of bloodstain analysis where gravity is the main force applied to blood. Part I is a preliminary study on the dynamics of blood flow on various inclined surfaces and examines the use of blood analogs for easy test replication. The flow of uncoagulated human blood at different volumes and temperatures was examined on wood at a set angle of 1.5°, and on glass at varying incline angles. Glycerol solutions of 59% and 42% were used to represent blood at 23°C and 37°C respectively. Glycerol flow trials of similar volumes were conducted on wood, PVC and glass. Fluid flow plots of distance versus time exhibited double exponential curve behaviour, although a power-law relationship derived by H. E. Huppert's (1982) flow expression was obtained for blood flowing on inclined wood. Blood flow exhibited several observable characteristics; a decreasing width of the leading edge over time, and streaking and component separation of the leading region at very low speeds. On a glass surface, the width of the initial flow region decreased and initial speed increased with increasing angles. The glycerol analogs used in this study did not represent their blood counterparts well due to differences in physical properties of the fluids. Part II of this study focuses on the forensic value of passive bloodstains on three fabrics; 100% cotton drill, 65/35 polyester cotton, and 100% Shantung silk. 26 µL drops of 37°C human blood were deposited onto the three fabrics and paper from a height of 14 cm at various impact angles. The stains were photographed and analysed qualitatively and quantitatively using computational methods. 100% cotton drill, 65/35 polyester cotton and ironed 100% Shantung silk provided useful forensic values such as direction of travel and angle of impact. Overall, this study has provided useful preliminary data for further research work.

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