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Babic, Darko Andre [Verfasser]. "Induktion und Detektion des VBNC-Zustandes in Pseudomonas aeruginosa / Darko Andre Babic." Wuppertal : Universitätsbibliothek Wuppertal, 2017. http://d-nb.info/1135940487/34.
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ZANDRI, GIADA. "Ruolo di forme VBNC di stafilococco presenti in biofilm associati a cateteri endovascolari." Doctoral thesis, Università Politecnica delle Marche, 2009. http://hdl.handle.net/11566/242379.
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Koblentz, Jenna A. "Variables in VBAC Success: A Retrospective Review of Trial of Labor After Cesarean (TOLAC) and Labor Support." Scholarship @ Claremont, 2015. http://scholarship.claremont.edu/scripps_theses/560.
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For most of the 20th century, the saying “once a cesarean, always a cesarean” was a rule in the United States. Today, the National Institutes of Health (NIH) opposes the dictum and urges women to consider trial of labor after cesarean (TOLAC). However, the factors that lead to a successful outcome remain unclear, as research continues to be conducted in hopes of creating a predictive model for vaginal birth after cesarean (VBAC) success.
The NIH’s request for more research in this area of obstetrics led to this retrospective cohort study of all TOLACs at Marin General Hospital (MGH) from 2000-2013. All labor trials were studied for patient demographics, details of labor, maternal and neonatal morbidities, insurance, and provider type. After confirming the quality of the data, verifying inclusion criteria and ignoring cases with missing data, a data set of 745 TOLACs with 13 explanatory variables of interest was prepared. A forward stepwise (Likelihood Ratio) binary logistic regression was run in IBM® SPSS® Statistics in order to create a model that could determine which variables were most predictive of delivery outcome in TOLAC patients.
Ultimately, seven variables were predictive and were included in the model. Of the seven, the most predictive variable in determining VBAC success was provider type. The model concluded that a woman’s odds of having a successful VBAC were almost four times greater if she began her delivery with a certified nurse midwife, than if she began her deliver with a physician (odds ratio 0.27, 95% CI 0.17-0.44; < 0.01). The results from this study mimic the results of other models, and introduce labor support as a key factor in predicting VBAC success.
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Megumi, Yuzuru. "Multiple roles of Rbx1 in the VBC-Cul2 ubiquitin ligase complex." Kyoto University, 2006. http://hdl.handle.net/2433/144318.
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Cacace, A. T., Y. Ye, Faith W. Akin, Owen D. Murnane, A. Pearson, R. Gattu, and E. M. Haacke. "Voxel-Based Morphometry (VBM) in Individuals with Blast/Tbi-Related Balance Dysfunction." Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etsu-works/1877.
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Alleron, Laëtitia. "Etude de l'état viable non cultivable (VBNC) chez Legionella pneumophila Lens après traitements monochloramine et thermique." Poitiers, 2008. http://theses.edel.univ-poitiers.fr/theses/2008/Alleron-Laetitia/2008-Alleron-Laetitia-These.pdf.
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Legionella pneumophila, l’agent responsable d’une pneumonie sévère atypique chez l’homme, appelée maladie du légionnaire, est ubiquitaire dans les environnements aquatiques. Les traitements généralement appliqués dans les réseaux d’eau afin d’éradiquer cette bactérie sont souvent suivis d’une recolonisation rapide de cette bactérie. Un des facteurs pouvant expliquer cette recolonisation peut être l’état Viable Non Cultivable (VBNC). L’objectif de nos travaux a été d’étudier la survie de L. Pneumophila après des traitements oxydant et thermique et notamment d’étudier l’état VBNC. Dans un premier temps nous avons réalisé un traitement monochloramine et un traitement thermique sur une suspension de légionelles. Nous avons observé que le traitement par 20 mg/L de monochloramine ainsi que celui à 57,5°C, conduisaient à la formation de VBNC chez L. Pneumophila. De plus ces bactéries peuvent persister dans cet état pendant au moins 169 jours après traitement. Dans un second temps, une étude partielle des protéines exprimées à l’état VBNC a été menée. Nous avons montré que l’expression de plusieurs protéines, impliquées dans les voies de production d’énergie, de synthèse protéique et dans la virulence, était augmentée d’un facteur supérieur ou égale à deux par comparaison avec des bactéries ayant subies un stress monochloramine ou une carence en nutriments. Dans un troisième temps, la recherche d’un facteur de ressuscitation Rpf a été entreprise chez L. Pneumophila. Un gène Rpf-like, possédant 33% d’identité et 51% de similarité avec celui de Salmonella, a été découvert. Ce gène a été cloné mais la protéine recombinante obtenue n’a pas conduit à un retour à la cultivabilité des cellulesLegionella pneumophila , the causative agent of an atypical severe pneumonia in human called Legionnaires’ disease, is ubiquitous in aquatic environments. The treatments usually applied to eradicate this bacterium are often followed by a quick new contamination. One of the causes that could explain this colonisation could be the Viable But NonCulturable state (VBNC). The aim of this work was to study the survival of L. Pneumophila after oxidative and heat treatments and then to study the VBNC. First, we have treated Legionella suspension with monochloramine and heat. We have observed that 20 mg/L monochloramine treatment and 57. 5°C treatment lead to the VBNC state. Moreover, these bacteria could persist in this state during at least 169 days. Secondly, we have realised a partial study of Legionella proteins expressed in the VBNC state. Several proteinsexpressions, implicated in energy production, protein synthesis and virulence, were induced more than 2-fold in comparison with bacteria stressed by monochloramine or in starvation. Finally, we have search for a Resuscitation-promoting-factor Rpf in L. Pneumophila genome. An rpf-like gene, showing 33% of identity and 51% similarity with Salmonella rpf was found. This gene has been cloned but the recombinant protein obtained didn’t lead to a recovery of legionella culturability
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Alleron, Laëtitia Frère Jacques. "Etude de l'état viable non cultivable (VBNC) chez Legionella pneumophila Lens après traitements monochloramine et thermique." Poitiers : I-Médias, 2008. http://theses.edel.univ-poitiers.fr/index.php?id-253.
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Veverka, Vojtěch. "Modely tranzistorů technologie CMOS 0.35 um I3T pro PSpice." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220362.
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The master’s thesis focuses on model designing of active components for PSpice simulator. Creation of models are based on text description, which is avaible in Cadence Spectre libraries. The aim of this thesis is approximate conversion of CMOS and bipolar tranzistors based on I3T 0.35 m technology. Simulation’s results and their comparation are discussed below.
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Highmore, Callum. "Decontamination of biofilm and VBNC zoonotic pathogens on the salad leaf phylloplane for enhanced food security and safety." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/419013/.
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Produce-associated outbreaks of foodborne pathogens such as Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica are rising in prominence among outbreaks of foodborne disease. Testing for foodborne pathogens by the agricultural industry relies heavily on culture-based techniques, excluding detection of viable but nonculturable (VBNC) pathogens. Here, a detection method is used that facilitates the use of qPCR on the complex environmental matrices of soil. Targeting the tir gene of E. coli O157, detection of the pathogen in peat-based compost and sand is achieved to a sensitivity of 10 CFU/g. When applied to pristine soil, 310 copies of the gene were detected. Further analysis using PNA-FISH and cell elongation determined the presence of 205 VBNC E. coli O157 cells per gram of soil sample. Resuscitation of the pathogen was achieved through prolonged enrichment in selective media. Decontamination of fresh produce using chlorine washes was simulated using L. monocytogenes and S. enterica serovar Thompson adhered to spinach leaves, resulting in complete VBNC induction of viable cells following two minutes exposure to 50 ppm and 100 ppm chlorine respectively. The infectivity of these chlorine induced VBNC pathogens was assessed in vivo using Caenorhabditis elegans as an animal model. VBNC L. monocytogenes retained its infectivity and caused a significant lifespan reduction (p=0.0064). Together, these data provide evidence of the presence and induction of VBNC foodborne pathogens throughout the food production chain, and determines that VBNC L. monocytogenes presents a threat to food safety.
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Toni, Jufner Celestino Vaz [UNESP]. "Transições reversíveis de células de leveduras entre estados viáveis, mas não cultiváveis (VBNC) e estados viáveis e cultiváveis." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/136009.
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000855447.pdf: 2348425 bytes, checksum: 43653b8cc49553da465fb52374eab833 (MD5)Diversos estados fisiológicos têm sido descritos para células de levedura durante o cultivo, como células lesionadas, células mortas e células viáveis, mas não cultiváveis (VBNC). No entanto, pouca atenção ainda é dada à formação de células viáveis, mas não cultiváveis em leveduras e seus impactos sobre o processo de fermentação. O estado VBNC, também conhecido como estado de dormência celular pode ser definido como um estado fisiológico em que os micro-organismos não são capazes de crescer em meios bacteriológicos, mas apresentam características de células vivas. Fatores químicos e ambientais têm sido relatados para induzir um estado VBNC, incluindo a falta de nutrientes, temperaturas extremas, concentrações osmóticas e oxigênio. As células de levedura no estado VBNC podem exercer influencias sobre o rendimento de biocombustível gerado no final do processo. As leveduras industriais utilizadas neste estudo foram coletadas em uma usina sucroalcooleira localizada na cidade de Américo Brasiliense-SP-Brasil. Para fornecer evidências da existência de um estado VBNC em leveduras investigou-se a capacidade das células ao entrarem no estado VBNC, aplicando estresse térmico (40°C) e osmótico (30% de sacarose). Populações viáveis foram monitoradas utilizando o corante azul de metileno, e as populações cultiváveis foram identificadas por semeadura em meio de cultura. Todos os procedimentos foram realizados em triplicata, para todas as amostras e os dados amostrais foram submetidos à análise de variância (ANOVA). Após 48 horas no período de tempo em estresse, a comparação entre as células viáveis e as células cultiváveis demonstrou a presença de células viáveis, mas não cultiváveis. Além disso, a remoção do estresse permitiu que as células fossem novamente capazes de crescer, fornecendo evidências da existência de um estado VBNC em leveduras.
Several physiological conditions have been described for yeast cells during cultivation, such as injured cells, dead cells and viable cells, but not culturable (VBNC). However, little attention is still given to the formation of viable cells, but not cultivable in yeast and its impact on the fermentation process. The VBNC state, also known as state of numbness cell can be defined as a physiological condition in which the microorganisms are not able to grow on bacteriological media, but that present characteristics of living cells. Chemical and environmental factors have been reported to induce VBNC state, including a lack of nutrients, temperature extremes, osmotic concentration and oxygen. The yeast cells in the VBNC state may influence the yield of biofuel generated at the end of the process. The yeasts used in this study were collected in a sugarcane mill located in Américo Brasiliense-SP-Brazil. To provide evidence of the existence of a state in yeast VBNC investigated the ability of cells to enter the VBNC state, applying heat stress (40°C) and osmotic (30% sucrose). Viable populations were monitored using the methylene blue dye, and cultivated populations were identified by inoculation in culture. All procedures were performed in triplicate for all samples and sample data were submitted to analysis of variance (ANOVA). After 48 hours the time of stress, the comparison between viable cells and culturable cells showed the presence of viable cells, but not culturable. Moreover, removal of stress the cells were allowed to grow again able, providing evidence for the existence of a VBNC state in yeast.
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Toni, Jufner Celestino Vaz. "Transições reversíveis de células de leveduras entre estados viáveis, mas não cultiváveis (VBNC) e estados viáveis e cultiváveis /." Araraquara, 2015. http://hdl.handle.net/11449/136009.
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Orientador: Cecília LaluceBanca: Maria Lucia Gonsales da Costa Araujo
Banca: Juliana Audi Giannoni
Resumo: Diversos estados fisiológicos têm sido descritos para células de levedura durante o cultivo, como células lesionadas, células mortas e células viáveis, mas não cultiváveis (VBNC). No entanto, pouca atenção ainda é dada à formação de células viáveis, mas não cultiváveis em leveduras e seus impactos sobre o processo de fermentação. O estado VBNC, também conhecido como estado de "dormência celular" pode ser definido como um estado fisiológico em que os micro-organismos não são capazes de crescer em meios bacteriológicos, mas apresentam características de células vivas. Fatores químicos e ambientais têm sido relatados para induzir um estado VBNC, incluindo a falta de nutrientes, temperaturas extremas, concentrações osmóticas e oxigênio. As células de levedura no estado VBNC podem exercer influencias sobre o rendimento de biocombustível gerado no final do processo. As leveduras industriais utilizadas neste estudo foram coletadas em uma usina sucroalcooleira localizada na cidade de Américo Brasiliense-SP-Brasil. Para fornecer evidências da existência de um estado VBNC em leveduras investigou-se a capacidade das células ao entrarem no estado VBNC, aplicando estresse térmico (40°C) e osmótico (30% de sacarose). Populações viáveis foram monitoradas utilizando o corante azul de metileno, e as populações cultiváveis foram identificadas por semeadura em meio de cultura. Todos os procedimentos foram realizados em triplicata, para todas as amostras e os dados amostrais foram submetidos à análise de variância (ANOVA). Após 48 horas no período de tempo em estresse, a comparação entre as células viáveis e as células cultiváveis demonstrou a presença de células viáveis, mas não cultiváveis. Além disso, a remoção do estresse permitiu que as células fossem novamente capazes de crescer, fornecendo evidências da existência de um estado VBNC em leveduras.
Abstract: Several physiological conditions have been described for yeast cells during cultivation, such as injured cells, dead cells and viable cells, but not culturable (VBNC). However, little attention is still given to the formation of viable cells, but not cultivable in yeast and its impact on the fermentation process. The VBNC state, also known as state of "numbness cell" can be defined as a physiological condition in which the microorganisms are not able to grow on bacteriological media, but that present characteristics of living cells. Chemical and environmental factors have been reported to induce VBNC state, including a lack of nutrients, temperature extremes, osmotic concentration and oxygen. The yeast cells in the VBNC state may influence the yield of biofuel generated at the end of the process. The yeasts used in this study were collected in a sugarcane mill located in Américo Brasiliense-SP-Brazil. To provide evidence of the existence of a state in yeast VBNC investigated the ability of cells to enter the VBNC state, applying heat stress (40°C) and osmotic (30% sucrose). Viable populations were monitored using the methylene blue dye, and cultivated populations were identified by inoculation in culture. All procedures were performed in triplicate for all samples and sample data were submitted to analysis of variance (ANOVA). After 48 hours the time of stress, the comparison between viable cells and culturable cells showed the presence of viable cells, but not culturable. Moreover, removal of stress the cells were allowed to grow again able, providing evidence for the existence of a VBNC state in yeast.
Mestre
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Desneux, Jérémy. "Étude de la survie et de la viabilité de Listeria monocytogenes dans les effluents d’élevages porcins." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S123/document.
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La listériose est une maladie rare mais grave d’origine alimentaire provoquée par Listeria monocytogenes. En raison de sa capacité de survie importante dans les sols, la présence de cette bactérie dans les effluents d’élevages porcins destinés à être épandus constitue un problème de santé publique. L’un des facteurs pouvant expliquer la persistance de L. monocytogenes dans l’environnement est sa capacité à entrer dans un état viable mais non cultivable (VNC). Nos travaux avaient pour objectif, d’une part de suivre le comportement de L. monocytogenes dans les effluents d'élevages porcins (lisier et effluent de lagune) et notamment les formes VNC, et d’autre part d’étudier son adaptation lors de son transfert dans les effluents de lagune et dans le sol. Dans un premier temps, nous avons optimisé les conditions de la qPCR couplée au propidium monoazide (qPCR-PMA) afin d’adapter cette méthode au dénombrement des formes VNC de L. monocytogenes dans le lisier et l’effluent de lagune. Dans un second temps, nous avons comparé par méthode culturale, qPCR-PMA et qPCR, la survie de deux souches de L. monocytogenes RifR de sérogroupes IIb et IVb inoculées dans deux lisiers et dans deux effluents de lagune incubés à 8°C et 20°C. Malgré leur origine et leur sérotype différents, les deux souches ont présenté une survie similaire dans toutes les conditions testées. La survie des deux souches a été affectée par la température (une persistance plus élevée a été observée à 8°C) et par l’origine des effluents. Cette étude a mis en évidence que L. monocytogenes était capable d’entrer dans l’état VNC dans les lisiers et les effluents de lagune indépendamment de la température. Les formes VBNC qui représentaient 83 à 99,8% des bactéries viables après 60 jours d’incubation, sont apparues dès les premières heures de contact avec les effluents. Leur proportion, plus élevée en début d’expérience dans les lisiers que dans les effluents de lagune, était cependant du même ordre de grandeur dans les deux types de matrices après 60 jours. Afin de mieux comprendre l’adaptation de L. monocytogenes lors de son transfert dans l’effluent de lagune et dans le sol, nous avons comparé le transcriptome par la technologie RNA-seq de la souche CIP 110868, isolée d’un lisier, inoculée dans des extraits stériles d’effluent de lagune et de sol. L’analyse du transcriptome a été réalisée à T0 (génome de référence), après 20 minutes et 20 heures d’incubation. L’analyse par enrichissement fonctionnel a révélé des modifications transcriptomiques dès les 20 premières minutes d’incubation dans les deux matrices. Une augmentation du taux de transcrit de gènes impliqués dans le transport de protéines et de sucres a été observée. Le taux de transcrit des gènes contrôlés par le facteur sigmaB est augmenté indiquant la mise en place d’une réponse aux stress osmotiques et thermiques. De plus, l’adaptation de la souche CIP 110868 dans les extraits de sol et d’effluent de lagune s’est accompagnée d’une augmentation au cours du temps des taux de transcrit des gènes impliqués dans la virulence et des gènes sous le contrôle du régulateur prfAListeriosis is a rare but serious illness caused by foodborne Listeria monocytogenes. Because of its important survival capacity in the soil, the presence of this bacteria in effluent from pig farms intended to be spread is a public health problem. One factor that may explain the persistence of L. monocytogenes in the environment is its ability to enter a viable but non-culturable state (VNC). Our studies were aimed, firstly to monitor the behavior of L. monocytogenes in effluent from pig farms (manure and lagoon effluent) including VNC forms, and also to study its adaptation at transfer to the lagoon effluent and soil. First, we have optimized the conditions of qPCR coupled with propidium monoazide (qPCR-LDCs) to adapt this method to count VNC forms of L. monocytogenes in the manure and lagoon effluent. Secondly, we compared by cultivation method, qPCR and qPCR-LDCs, the survival of two strains of L. monocytogenes RifR IIb and IVb serogroups manure inoculated in two and two lagoon effluent incubated at 8 ° C and 20 ° C. Despite their origin and different serotype, the two strains showed a similar survival in all conditions tested. The survival of both strains was affected by the temperature (higher persistence was observed at 8 ° C) and the origin of the effluent. This study showed that L. monocytogenes was able to enter the VNC state in manure and lagoon effluent regardless of temperature. VBNC forms which accounted for 83 99.8% of viable bacteria after 60 days of incubation, appeared in the early hours of contact with effluent. Their proportion, higher at the beginning of experience in the manure lagoon in the effluent, however, was of the same order of magnitude in the two types of matrices after 60 days. To better understand the adaptation of L. monocytogenes when transferred into the lagoon effluent and soil, we compared the transcriptome by RNA-Seq technology CIP 110868 strain, isolated from a slurry inoculated in sterile effluent lagoon and extracts of soil. Transcriptome analysis was performed at T0 (reference genome), after 20 minutes and 20 hours of incubation. Functional enrichment analysis revealed transcriptomic changes during the first 20 minutes of incubation in both matrices. An increase in the gene transcript levels involved in the transport of proteins and sugars was observed. The rate of transcribed genes controlled by the sigmaB factor is increased indicating the establishment of a response to osmotic and thermal stress. In addition, the adaptation of the CIP 110868 strain in soil extracts and lagoon effluent was accompanied by an increase in time of transcript levels of genes involved in virulence and gene under the control the prfA regulator
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Darke, Carljohan, and Oscar Lundström. "The role of management control systems in the VBHC strategy formulation process : Exploring management control systems as a package." Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-297397.
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The study explores the role of management control systems in a strategy formulation process, this by viewing management control systems as a package and addressing its role in the Value Based Health Care (VBHC) strategy formulation process at Uppsala University Hospital. Previous studies exploring the relationship between management control systems and strategy have found the relationship to be interrelated and that management control systems can take either an interactive or diagnostic role. However, these studies are limited in their approach as they do not address management control systems as a package, thus failing to capture the importance of informal control systems and the impact separate controls have on each other. Applying a case study design using semi-structured interviews, the study partly supports the findings of earlier studies emphasizing how management control systems can be classified and used for both interactive as well as diagnostic purposes. The study however, expands the view of earlier research by emphasizing how diagnostic controls should be further classified as either enforcing or reinforcing control systems, as well as emphasizing the importance of timing for understanding the different roles of management control systems in a strategy formulation process.
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Kortebi, Mounia. "Caractérisation d’une phase de persistance intracellulaire du pathogène Listeria monocytogenes." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS477/document.
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Listeria monocytogenes est une bactérie pathogène intracellulaire facultative responsable d’une pathologie grave, la listériose. Si de très nombreux travaux ont permis de caractériser les mécanismes de virulence de cette bactérie, il existe peu de données sur les mécanismes conduisant au portage asymptomatique de L. monocytogenes dans les hôtes mammifères. L’un de ces mécanismes pourrait être une phase de persistance intracellulaire. Lors d’infections prolongées de cellules épithéliales humaines en culture, comme des hépatocytes et des cellules de trophoblastes, L. monocytogenes change de mode de vie intracellulaire. Après la phase active de dissémination de cellule en cellule, les bactéries arrêtent de polymériser l’actine et se retrouvent piégées dans des vacuoles à simple membrane marquées par la protéine endosomale LAMP1. L’objectif de ma thèse était de caractériser ces « Listeria-Containing Vacuoles » (LisCVs). Nous avons montré que les LisCVs sont des compartiments acides, partiellement-dégradatifs, marquées par la protéase lysosomale cathépsine D. Leur formation coïncide avec la disparition du facteur de polymérisation d’actine ActA de la surface bactérienne et la capture des bactéries cytosoliques dépourvues d’actine par des membranes cellulaires. Dans ces compartiments, les bactéries entrent en croissance ralentie ; une sous-population résiste aux stress et peut survivre au-delà de trois jours d’infection. L’utilisation de la gentamicine lors du protocole d’infection n’est pas responsable de la formation des LisCVs. Cependant, cet antibiotique permet la sélection des bactéries vacuolaires, en inhibant spécifiquement la croissance des bactéries cytosoliques. La formation des LisCVs n’est pas spécifique des souches de laboratoire. Toutefois l’efficacité du phénomène pourrait diverger selon les séquençotypes des souches de L. monocytogenes. Les bactéries vacuolaires ont la capacité de sortir des vacuoles et de retourner vers un état motile et réplicatif, après le passage des cellules infectées. Lorsque l’expression du gène actA reste inactive, comme dans les mutants ∆actA, des formes de Listeria vacuolaires persistent dans les cellules hôtes dans un état viable mais non cultivable (VBNC). Ces formes VBNC peuvent être transmises au cours des divisions des cellules hôtes. L’ensemble de ces résultats révèle une nouvelle phase de persistance dans le processus infectieux intracellulaire de L. monocytogenes lors des infections prolongées de certaines cellules épithéliales. Cette propriété pourrait contribuer au portage asymptomatique de ce pathogène dans les tissus épithéliaux, allonger la période d'incubation de la listériose, et rendre les bactéries tolérantes à l’antibiothérapieListeria monocytogenes is a facultative intracellular pathogenic bacterium responsible for a serious disease, listeriosis. Although much work has been done to characterize the virulence mechanisms of this bacterium, there is little data on the mechanisms leading to the asymptomatic carriage of L. monocytogenes in mammalian hosts. One of these mechanisms could be a phase of intracellular persistence. During prolonged infections of human epithelial cells in culture, such as hepatocytes and trophoblast cells, L. monocytogenes changes its intracellular lifestyle. After the active phase of cell-to-cell spread, the bacteria stop polymerizing actin and become trapped in single-membrane vacuoles labeled with the endosomal protein LAMP1.The aim of my thesis was to characterize these "Listeria-Containing Vacuoles" (LisCVs). We have shown that LisCVs are acidic, partially degradative compartments, labeled by the lysosomal protease cathepsin D. Their formation coincides with the disappearance of actin polymerization factor ActA from the bacterial surface and the capture of actin-free cytosolic bacteria by cell membranes. In these compartments, bacterial growth is slowed; a subpopulation is resistant to stress and can survive beyond three days of infection. The use of gentamicin during the infection protocol is not responsible for the formation of LisCVs. However, this antibiotic allows selection of vacuolar bacteria, by specifically inhibiting the growth of cytosolic bacteria. The formation of LisCVs is not specific to laboratory strains. However, the efficacy of the phenomenon could diverge according to the sequence types of L. monocytogenes strains. Vacuolar bacteria have the ability to exit the vacuoles and return to a motile and replicative state during the subculture of infected cells. When expression of the actA gene remains inactive, as in ΔactA mutants, vacuolar Listeria forms persist in host cells in a viable but non-culturable (VBNC) state. These VBNC forms can be transmitted during host cell divisions. All these results reveal a new phase of persistence in the intracellular infectious process of L. monocytogenes during prolonged infections of a subset of epithelial cells. This property could contribute to asymptomatic carriage of this pathogen in epithelial tissues, extend the incubation period of listeriosis, and make bacteria tolerant to antibiotic therapy
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Tran, Dao. "Identifying risks associated with organic soil amendments: microbial contamination in compost and manure amendments." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/27364.
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The application of animal manures to agricultural land as a soil organic amendment has been identified as an important route by which foodborne pathogens can enter the human food chain. Knowledge of the presence and incidence of key foodborne pathogens in manure is a vital first step in the establishment of sound and effective guidelines for management and prevention of contamination by manure. The work described in this thesis attempts to determine the persistence of pathogens when raw manures are directly applied to agricultural soils, and treated under thermophilic composting conditions. Results from this study indicated that the current conditions suggested by typical food safety guidelines are sufficient to reduce the population of enteric bacteria to levels that minimise risks associated with culturable cells in raw manure and finished compost. However, E. coli cells have the potential to enter a viable but non-culturable (VBNC) state and are undetected by culture-based monitoring methods, thus providing a false impression of the innate risk of the product. Prc, bamB and tolA, which are responsible for stabilising the cell membrane, were found to be essential genes required for surviving heat treatment at 55°C. In addition, the presence of relA and oxyR suggested that E. coli may use the VBNC state as an adaptive strategy for long-term survival to withstand multiple stresses, including heat stress. Entering the VBNC state with a strengthen cell envelope may help E. coli to survive prolonged heating during standard composting conditions. Successful resuscitation from the VBNC state was achieved in the presence of cell-free supernatant from actively growing E. coli MG1655. These results underline the importance of considering VBNC cells when evaluating the sanitary effect of the composting process. VBNC cells in composts could facilitate the persistence of pathogens in manure-amended soil and thus pose a risk of microbial contamination of fresh produce.
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Koechlein, David Jacob. "A Study of the Coccoid Bodies of Prolinoboborus fasciculus (Aquaspirillum fasciculus)." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/35624.
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Following active growth, the aquatic gram-negative rod Prolinoborus fasciculus (Aquaspirillum fasciculus) exhibited a mass conversion from its culturable rod form to a nonculturable coccoid form. Chloramphenicol did not prevent the conversion. Attempts to obtain variants that would not convert to the coccoid form were unsuccessful. Although the coccoid form fluoresced with acridine orange, agarose gel electrophoresis revealed extensive ribosomal RNA degradation. Poly-Ã -hydroxybutyrate, abundant in the vegetative rods, was not detectable in the coccoid cells. The results suggest that the coccoid form of A. fasciculus is a degenerative form rather than part of a life cycle.Master of Science
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Pasquaroli, Sonia. "Induction of viable but nonculturable state in Staphylococcus aureus biofilms obtained in vitro." Doctoral thesis, Università Politecnica delle Marche, 2011. http://hdl.handle.net/11566/242106.
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Staphylococcus aureus è uno dei più importanti patogeni umani. Può causare patologie di diversa gravità, tossinfezioni alimentari ed infezioni sistemiche. Molti ceppi sono capaci di sviluppare biofilm, cioè una matrice esopolisaccaridica (slime) adesa ad una superficie, all’interno della quale rimangono inglobati i microrganismi produttori. Gli stafilococchi produttori di biofilm sono frequentemente coinvolti nelle infezioni associate all’uso di dispositivi medici impiantabili, come cateteri venosi centrali. Tali infezioni risultano difficili da eradicare in quanto i batteri risultano protetti sia dai sistemi di difesa dell’ospite che dalla terapia antibiotica. All’interno del biofilm, al contempo, i microrganismi trovano condizioni ambientali sfavorevoli come la carenza di ossigeno e di nutrienti in grado di indurre la trasformazione in forme quiescenti, tra cui lo stato VBNC (Viable But NonCulturable). Le forme VBNC rappresentano una strategia di sopravvivenza delle cellule batteriche non sporulanti sottoposte a stress ambientali, come variazioni di temperatura, luce solare, concentrazione di ossigeno e carenza di nutrienti. Sono caratterizzate da assenza di coltivabilità nei classici terreni di coltura, attività metabolica ridotta, modificazioni morfo-funzionali e dalla capacità di recuperare la capacità replicativa (resuscitation), quando le condizioni tornano favorevoli. Sono state descritte per diverse specie, soprattutto ambientali, ed anche per patogeni umani, ma la possibilità per gli stafilococchi di entrare in uno stato VBNC non è stata mai dimostrata.
Questa attività di ricerca è stata rivolta a valutare la possibilità che S. aureus possa entrare in uno stato vitale ma non coltivabile, capace di resuscitation, quando si trova all’interno di biofilm. A tale scopo sono stati allestiti modelli di biofilm in vitro del ceppo S. aureus 10850 (forte produttore di slime) e in parallelo di S. aureus ATCC 25923 (non produttore di slime) e sottoposti a condizioni di stress, in particolare carenza di nutrienti associata o meno alla presenza di vancomicina, synercid o daptomicina (antibiotici utilizzati per contrastare le infezioni gravi sostenute da S. aureus) in concentrazioni pari o superiori (4x, 8x, 16x) alla minima inibente (MIC). La presenza di cellule vitali nei campioni non più coltivabili è stata valutata mediante microscopia in epifluorescenza e citometria a flusso dopo colorazione live-dead con i fluorocromi SYBR Green I e Ioduro di propidio; la capacità di espressione genica delle forme VBNC rilevate è stata analizzata mediante saggi di RT-PCR e Real-time RT-PCR specifici per il 16SrDNA batterico e per i geni glsF e nuc, il primo housekeeping specie-specifico per S. aureus e il secondo codificante per un fattore di virulenza. E’ stata inoltre valutata la possibilità delle forme VBNC di recuperare l’attività replicativa (resuscitation) ricreando condizioni di crescita favorevoli.
I risultati ottenuti hanno dimostrato che (i) S. aureus è in grado di entrare in uno stato VBNC, ma solo all’interno di biofilm. Infatti forme VBNC sono state ottenute solo con il ceppo produttore di biofilm S. aureus 10850, mentre non è stato possibile rilevare la presenza di cellule vitali ma non coltivabili di S. aureus ATCC 25923; ii) condizioni di starvation in presenza di basse concentrazioni di vancomicina, synercid o daptomicina possono indurre lo stato VBNC; (iii) nello stato non coltivabile le cellule di S. aureus mantengono un’attività metabolica, come dimostrato dall’espressione di tutti i geni analizzati e che (iv) le forme VBNC di S. aureus sono in grado di riacquisire la capacità replicativa se poste in presenza di terreni di coltura addizionati di metaboliti essenziali per lo sviluppo cellulare, come il piruvato di sodio o il filtrato di una brodocoltura del ceppo wild-type S. aureus 10850.
Questi risultati indicano che le forme VBNC di stafilococco potrebbero avere un ruolo rilevante in patologia umana in quanto capaci di rimanere latenti, e non evidenziabili con i comuni test colturali, all’interno del biofilm, ed essere causa di infezioni ricorrenti in seguito al recupero della piena attività metabolica e della conseguente capacità di moltiplicarsi.Staphylococcus aureus is a major human pathogen. Its toxins can cause disease of varying severity, including food poisoning and a number of infections. Several strains form biofilms, i.e. multicellular aggregates encased in an exopolysaccharide matrix (slime) produced by the bacteria themselves. Biofilm-producing staphylococci are frequently involved in infections associated with the use of medical devices (e.g. catheter-related bloodstream infections). These biofilms protect bacteria from both host defences and antibiotic therapy, resulting in considerable difficulty in eradication. Bacteria residing in biofilms need to cope with adverse environmental conditions, such as oxygen and nutrient deficiency, that can induce a “dormant” state, like the Viable But NonCulturable (VBNC) state. VBNC forms are a survival strategy of non-sporulating bacteria subjected to environmental stress (e.g. changes in temperature or visible light, oxygen or nutrient deficiency). The VBNC state, a potential reservoir of pathogenic microorganisms, has been described for several gram-positive and negative species, both environmental and clinical. This survival strategy is characterized by the absence of culturability on culture media, low metabolic activity, and morpho-functional changes. Moreover, optimal growth conditions can “resuscitate” true VBNC cells, restoring replication capacity and full metabolic activity. The ability of staphylococci to enter the VBNC state has never been demonstrated. This work aimed to establish (i) whether S. aureus biofilms can give rise to VBNC forms that can resuscitate in suitable environmental conditions, and (ii) the role of different stressors in inducing the VBNC state. Cultures of S. aureus 10850 (a strong slime producer) and S. aureus ATCC 25923 (a non-slime producer) were grown on filter membranes under conditions suitable for biofilm development (i.e. presence of glucose) and exposed to different stress conditions, i.e. depletion of nutrients, in the presence or absence of minimum inhibitory concentrations (MICs) and of 4-fold, 8-fold and 16-fold MICs of vancomycin, synercid and daptomycin, three antibiotics used to treat severe Gram-positive infections. Culturability was monitored at intervals of three days. After cells had reached the nonculturable state they were subjected to live-dead staining using SYBR Green I and propidium iodide and their viability was tested by epifluorescence microscopy and flow cytometry. Gene expression was analyzed using RT-PCR and Real-time RT-PCR assays targeting bacterial 16SrDNA, glsF (a housekeeping, species-specific gene) and nuc (the gene coding for a thermostable nuclease) genes. VBNC forms were then assessed for their ability to recover replication activity through exposure to favourable growth conditions. The results of these experiments showed that (i) S. aureus is capable of entering the VBNC state provided that cells are contained in biofilm, because viable but nonculturable cells of S. aureus ATCC 25923 (the non-slime producer) were never recovered; (ii) VBNC S. aureus forms can be induced by starvation and antibiotics; (iii) VBNC S. aureus cells retain their metabolic activity, as demonstrated by positive gene expression assays; and (iv) VBNC S. aureus cells exposed to suitable culture conditions can revert to the culturable state (resuscitation). VBNC staphylococci may have a significant clinical role, since they can pass from the dormant state, where they are undetectable by routine methods within biofilm, to full metabolic and replication activity, causing severe infections.
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Linke, Stefan [Verfasser]. "Untersuchungen zur erhöhten Toleranz von biofilmassoziierten Mikroorganismen und die Ausbildung von vbnc-Zuständen bei Pseudomonas aeruginosa gegenüber chlorabspaltenden Verbindungen / Stefan Linke." Bonn : Universitäts- und Landesbibliothek Bonn, 2013. http://d-nb.info/1044870257/34.
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Nicklas, Anne [Verfasser]. "In-vivo-Untersuchungen zu strukturellen Gehirnveränderungen bei chronischem lumbalem Rückenschmerz mittels Voxel-basierter Morphometrie (VBM) / Anne Nicklas." Köln : Deutsche Zentralbibliothek für Medizin, 2013. http://d-nb.info/1044190647/34.
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Schmalzigaug, Vivian. "Uma experiência na utilizacao do vbm (value based management) como ferramenta de desenvolvimento de estratégias de negócio." reponame:Repositório Institucional do FGV, 1996. http://hdl.handle.net/10438/5508.
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Made available in DSpace on 2010-04-20T20:19:53Z (GMT). No. of bitstreams: 0
Previous issue date: 1996-06-18T00:00:00ZEsta tese baseia-se na experiência adquirida com a participação num projeto de implantação do conceito de Value Based Management em urna empresa multinacional de bens de consumo. A maior parte do material aqui comentado foi colhido durante o primeiro semestre do ano de 1995 - período em que durou o projeto - e parte durante duas semanas no início do ano, nas quais participei em Londres de um treinamento intensivo, ministrado por uma conceituada firma de consultoria internacional, sobre a teoria e prática deste novo conceito, juntamente com diversos participantes de outros projetos VBM ao redor do mundo como Estados Unidos, França, Itália, Alemanha, Inglaterra, Espanha, entre outros
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Serafin, Marta <1995>. "The family firms succession paradox: how to preserve family influence while hiring external managers. A VBM perspective." Master's Degree Thesis, Università Ca' Foscari Venezia, 2020. http://hdl.handle.net/10579/16987.
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This study aims first at underlying the role of External Managers as crucial contributors to diversification and professionalization of Family Firms TMT, with the backing of specific theories such as the Upper Echelons and the Faultline Model. A careful analysis will bring out the positive side of Non Family Members inclusion, with particular emphasis on the beneficial impact on the firm performance.
Even though the benefits deriving from the cooperation of family and nonfamily leaders are empirically proved, critics reveal the emergence of several problems related to the inclusion of external managers. On one hand, agency problems occurs, defined as a conflict of interest between the company’s stockholder (in this case, the family) and the company’s managers (who are Non Family Members).This type of conflict is common in almost every organizational structure in which ownership and management do not match, and derives from the fact that managers, acting as the agent for the principals, have the duty to make decisions in order to maximize the owners’ wealth instead of their own wealth, which is the natural vocation of every individual. On the other hand, the rise of a much more family firm-peculiar problem can be identified in the loss of Socio-Emotional Wealth, crucial feature of family organizations which represent all those “non-financial aspects of the firm that meet the family's affective needs, such as identity, the ability to exercise family influence, and the perpetuation of the family dynasty” (Gomez-Mejia and al. 2007). Indeed, family firms are characterized by a double purpose: the profitability of the business, but also the preservation of the business value and culture. This latter aspect is hardly communicable and understandable to nonfamily managers, and family firms, scared of the potential loss of the business core values, may refuse to engage outsiders in the management structure to avoid such loss.
Aware of the enormous advantages deriving from the introduction of professional outsiders within the management, scholars and practitioners have identified many ways to overcome the obstacles to integration (especially the agency conflicts). On one side, through the implementation of monetary incentives (wages and bonuses) and non-monetary incentives (pleasant work atmosphere, stimulating work content, addictive management culture, good degree of freedom for action). On the other, through an effective monitoring activity carried out by family-ruled controlling bodies. However, it must be stressed the idea that family businesses seek not only managers-employees, but rather “co-entrepreneurs” who are suited to the firm and the family, which means that the aim is to find a good emotional and cultural fit, besides a professional support. In this regard, the last part of the study is dedicated to propose the managerial philosophy of Value Based Management as an appropriate instrument to improve decision making quality and mitigate agency conflicts within family businesses, even if this technique was born for and generally applies to publicly traded companies.
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Mseddi, Eya. "Exploration cérébrale structurelle et morphologique de la posture chez des patients atteints de sclérose latérale amyotrophique." Thesis, Paris 10, 2017. http://www.theses.fr/2017PA100162.
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La sclérose latérale amyotrophique [SLA] est une pathologie idiopathique à issue fatale caractérisée par la dégénérescence progressive et sélective des motoneurones du système nerveux central et périphérique. La SLA n’est pas exclusivement identifiée comme une maladie de la voie pyramidale, mais considérée plus largement comme une pathologie neurodégénérative multisystème. L’étude des mécanismes posturaux dans cette population n’a pas fait l’objet d’une grande attention. Dans ce travail de thèse, une exploration en imagerie cérébrale multimodale (imagerie en tenseur de diffusion [DTI] et morphométrie basée sur le voxel [VBM]) est proposée chez des patients SLA avec instabilité posturale [AIP] et stables [SIP] en vue de vérifier l’intégrité morphologique et structurelle des régions corticales et sous-corticales posturales. La comparaison entre les sujets contrôles et les patients SLA a démontré une augmentation significative du volume de la substance grise au niveau du noyau caudé chez les patients stables (SIP vs contrôle p<0,001 ; SIP vs AIP p<0,01). L’évaluation structurelle a révélé une diminution de la fraction d’anisotropie [FA] au niveau de l’aire motrice supplémentaire [AMS] dans les deux groupes de patients par rapport aux contrôles (contrôle vs SIP p<0,05 ; contrôle vs AIP p<0,001). Au niveau du noyau caudé, le groupe AIP a présenté une diminution de la valeur de la FA par rapport aux sujets contrôles (p<0,001) et aux sujets SIP (p<0,05). Ainsi, ces résultats contribuent à une meilleure caractérisation et compréhension des atteintes corticales et sous corticales des régions qui interviennent dans la posture chez les patients SLAThe Amyotrophic Lateral Sclerosis [ALS] is an idiopathic pathology with a fatal outcome. It is characterized by a progressive and selective degeneration of motor neurons in the central and peripheral nervous system. ALS is no longer exclusively identified as a disease of the pyramidal pathway, but it is considered more broadly as multisystem neurodegenerative pathology. However, the analysis of postural processes in these patients has not been well studied in the literature. Multimodal brain imaging (Diffusion Tensor Imaging [DTI] and Voxel Based Morphometry [VBM]) exploration was performed for ALS patients with postural instability [AIP] and without postural instability [SIP] to test the morphometric and structural integrity of postural cortical and subcortical regions. A significant increase of gray matter in caudate nucleus volume has been noticed for stable patients (SIP vs controls p<0.001, SIP vs AIP p<0.01). The structural evaluation revealed a decrease of the Fractional Anisotropy [FA] at the Supplementary Motor Area [SMA] level in both groups of patients compared to controls (controls vs SIP p<0.05, controls vs. AIP p<0.001). At the caudate nucleus, the AIP group showed FA value decrease compared to controls (p<0.001) and SIP subjects (p<0.05). Thus, these results would contribute to a better characterization and understanding of the cortical and subcortical impairments of the postural regions in ALS patients
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Shoemaker, Esther Susanna. "Childbirth Decision Making Processes: Influences on Mode of Birth After a Previous Caesarean Section." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35504.
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Background: An increasing proportion of Canadian women are experiencing a Caesarean section (CS) and a subsequent repeat CS. While CS can be necessary and lifesaving for mothers and their infants in some situations, it is also associated with greater morbidity risks to women and infants than vaginal birth. Clinical practice guidelines recommend the involvement of pregnant women in making decisions about mode of birth and shared decision making improves the informed consent process. This research examines the factors that influence mode of birth after a previous CS.
Methods: Two cross sectional descriptive studies and a prospective pre-post cohort study with control were conducted to investigate the high use of repeat CS at the levels of health care providers, maternity care clients, and the organizational structure of a birthing unit.
1. Interviews and surveys with obstetricians, family physicians, midwives, and nurses were conducted to investigate the attitudes, values, and perceptions that guide their care practices for clients with a previous CS. The specific research question was: What are the factors that influence the practices of maternity care providers (obstetricians, family physicians, midwives, and nurses) regarding mode of birth after a previous CS? Data was analyzed using iterative deductive and inductive coding.
2. Interviews and surveys were conducted during pregnancy and after giving birth with healthy women who have had a previous CS to explore their decision making processes regarding mode of birth after a previous CS. The specific research question was: How do women eligible for a VBAC make decisions about their upcoming mode of birth? A thematic framework approach was used for data analysis.
3. Data from the Better Outcomes Registry and Network (“BORN”) Ontario was analyzed to examine the effectiveness of a hospital based strategy on overall proportions of CS and within Robson groups 1, 2a, and 5. The Caesarean section reduction (CARE) strategy includes interventions that target health care providers, pregnant women, and hospital policies.
Results:
1. Maternity care providers would recommend a vaginal birth after CS (VBAC) for healthy pregnant women with a previous CS. They had different perceptions of the safety of birth to the health of women and infants and different approaches to engage in decision making during consultation. Providers believed women make their decision about mode of birth outside of the clinical consultation and often prior to their subsequent pregnancy.
2. The main themes that influenced the decisions of maternity care clients about mode of birth were mothers’ experiential reasoning regarding mode of birth and recovery, experiential knowledge from significant others, scheduling of CS regardless of the mode of birth decision, rating and prioritizing risks, fear of risks, and decisional conflict. When women discussed the factors that impacted their decisions about mode of birth six to eight weeks after they had given birth, the main themes were the recovery experience and fear related to the mode of birth. A lack of time during consultation was identified as a major barrier inhibiting shared decision making, specifically among clients of obstetricians. Other barriers included reliance on routine obstetric practices that are not evidence based.
3. Proportions of CS decreased at the intervention hospital by 3.9% (p=0.0006), from 30.3% (n=964) in 2009/10 to 26.4% (n=803) in 2012/13. During the same time frame, proportions of CS in the control group were stable with 28.1% (n=23,694) in 2009/10 and 28.2% (n=23,683) in 2012/13. Within the Robson classification system, the proportions of repeat CS among all low risk women with a previous CS decreased at the intervention hospital by 5.6% (p=0.0044) from 84.3% to 78.7%. In the control group, also fewer women had a repeat CS over the study period, but the decrease was smaller with 3.9% (p<0.0001) from 84.5% to 80.6%.
Conclusion: A true shared decision making process addresses the power imbalance between providers and women through an incorporation of the clinical expertise of providers and the experiential expertise of pregnant women before reaching a decision about mode of birth. The use of routine obstetric practices that are not evidence based inhibited women to make decisions about their mode of birth. The introduction of the CARE strategy to a hospital birthing unit was associated with improvements in proportions of CS and VBAC among low risk women.
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Santiwatanakul, Somchai. "A study of the coccoid form and the autolysins of Campylobacter upsaliensis." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30509.
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Conversion of Campylobacter upsaliensis to the nonculturable but viable coccoid form was characterized. Chloramphenicol did not prevent the conversion. Severe decreases in isocitrate dehydrogenase activity and oxygen uptake and extensive degradation of ribosomal RNA suggest that the coccoid form is a degenerative form rather than part of a life cycle. The autolysins of spiral and coccoid forms of C. upsaliensis were also studied. Autolytic activity in the soluble and sediment fractions of sonicates of the spiral and the coccoid form of C. upsaliensis could not be demonstrated by native (nondenaturing) PAGE. Autolysins were detected, however, by using denaturing SDS-PAGE gels containing either purified E. coli peptidoglycan or whole cells of Micrococcus luteus as the turbid substrate, with subsequent renaturation by treatment with Triton X-100 buffer. In renaturing gels that contained E. coli peptidoglycan, 14 autolytic bands were detected ranging from 200 kDa to 12 kDa. In similar gels containing whole cells of M. luteus , only a single band appeared having a molecular weight of 34 kDa. This band corresponded to one of the bands present in the gels containing E. coli peptidoglycan. This common autolysin was isolated by adsorbing it from C. upsaliensis lysates onto M. luteus cells and then subjecting these cells to renaturing SDS-PAGE in gels containing E. coli peptidoglycan. The 34 kDa autolysin differed from a single 51 kDa autolysin unique to the M. luteus cells. The 34 kDa autolysin was isolated from an SDS-PAGE gel and was pure when tested by isoelectric focusing. The N-terminal amino acid sequence analysis showed the first 15 amino acids of the 34 kDa autolysin to have 67% identity with a part of antigenic protein PEB4 of Campylobacter jejuni. The purified autolysin was used to immunize rabbits and the antibodies produced precipitated autolytic activity from cell lysates. The specificity of the antibodies was shown by Western blotting: only a single specific band occurred, with a molecular weight of 34 kDa, and thus it seems unlikely that the 34 kDa autolysin was derived from any of the other autolysins that were detected.Ph. D.
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BOWNE, SHELL L. "MIDWIVES IN A PRECARIOUS BALANCE OF POWER WITHIN THE HEALTH CARE SYSTEM OF THE UNITED STATES." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1016569336.
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Streitbürger, Daniel-Paolo. "Investigating Brain Structure Using Voxel-Based Methods with Magnetic Resonance Imaging." Doctoral thesis, Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-132638.
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The number of people suffering from neurodegenerative diseases, such as Alzheimer`s disease, increased dramatically over the past centuries and is expected to increase even further within the next years. Based on predictions of the World Health Organization and Alzheimer`s Disease International, 115 million people will suffer from dementia by the year 2050. An additionally increase in other age related neurodegenerative diseases is also forecasted. Quite naturally, neurodegenerative diseases became a focus of attention of governments and health insurances, trying to control the uprising financial burden. Early detection and treatment of neurodegenerative diseases could be an important component in containing this problem. In particular, researchers focused on automatic methods to analyze patients’ imaging data. One way to detect structural changes in magnetic resonance images (MRI) is the voxel-based method approach. It was specifically implemented for various imaging modalities, e.g. T1-weighted images or diffusion tensor imaging (DTI). Voxel-based morphometry (VBM), a method specifically designed to analyze T1-weighted images, has become very popular over the last decade. Investigations using VBM revealed numerous structural brain changes related to, e.g. neurodegeneration, learning induced structural changes or aging. Although voxel-based methods are designed to be robust and reliable structural change detection methods, it is known that they can be influenced by physical and physiological factors. Dehydration, for example, can affect the volume of brain structures and possibly induce a confound in morphometric studies. Therefore, three-dimensional T1-weighted images were acquired of six young and healthy subjects during different states of hydration. Measurements during normal hydration, hyperhydration, and dehydration made it possible to assess consequential volume changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). The datasets were analyzed using VBM, FreeSurfer and SIENA. A significant decrease of GM and WM volume, associated with dehydration, was found in various brain regions. The most prominent effects were found in temporal and parietal areas, in the left inferior orbito-frontal region, and in the extra-nuclear region. Moreover, we found consistent increases in CSF, an expansion around 6% of the ventricular system affecting both lateral ventricles, i.e. the third and fourth ventricle. Similar degrees of shrinkage in WM volume and increase of the ventricular system have been reported in studies of Alzheimer’s disease during disease progression and in its prestage mild cognitive impairment. Based on these findings, a potential confound in GM and WM or CSF studies due to the subjects’ hydration state cannot be excluded and should be appropriately addressed. These results underline the sensitivity of VBM and might also concern other voxel-based methods, such as Tract-Based Spatial Statistics (TBSS). TBSS was specifically designed for WM analyses and its sensitivity might be helpful for revealing the spatial relation of structural WM changes and related blood serum biomarkers. Two common brain related biomarkers are the glial protein S100B, a plasticity inducing neuro- and gliotrophin, and neuron-specific enolase (NSE), a marker for neuronal damage. However, the spatial specificity of these biomarkers for brain region has not been investigated in vivo until now. Therefore, we acquired two MRI parameters – T1- weighted and DTI - sensitive to changes in GM and WM, and obtained serum S100B and NSE levels of 41 healthy subjects. Additionally, the gene expression of S100B on the whole brain level in a male cohort of three subjects from the Allen Brain Database was analyzed. Furthermore, a female post mortal brain was investigated using double immunofluorescence labeling with oligodendrocyte markers. It could be shown that S100B is specifically related to white matter structures, namely the corpus callosum, anterior forceps and superior longitudinal fasciculus in female subjects. This effect was observed in fractional anisotropy and radial diffusivity – the latest an indicator of myelin changes. Histological data confirmed a co-localization of S100B with oligodendrocyte markers in the human corpus callosum. S100B was most abundantly expressed in the corpus callosum according to the whole genome Allen Human Brain Atlas. In addition, NSE was related to gray matter structures, namely the amygdala. This effect was detected across sexes. The data demonstrates a very high S100B expression in white matter tracts, in particular in human corpus callosum. This was the first in vivo study validating the specificity of the glial marker S100B for the human brain, and supporting the assumption that radial diffusivity represents a myelin marker. The results open a new perspective for future studies investigating major neuropsychiatric disorders. All above mentioned studies are mainly dependent on the sensitivity and accuracy of soft and hardware parameters. In particular, technical developments have improved acquisition accuracy in the field of MRI. Interestingly, very little is known about the confounding effects of variations due to hardware parameters and their possible impact on reliability and sensitivity of VBM. Recent studies have shown that different acquisition parameters may influence VBM results. Therefore age-related GM changes were investigated with VBM in 36 healthy volunteers grouped into 12 young, 12 middle-aged and 12 elderly subject. Six T1-weighted datasets were acquired per subject with a 12-channel matrix coil, as well as a 32-channel array, MP-RAGE and MP2RAGE, and with isotropic resolutions of 0.8 and 1 mm. DARTEL-VBM was applied on all images and GM, WM and CSF segments were statistically analyzed.. Paired t-tests and statistical interaction tests revealed significant effects of acquisition parameters on the estimated gray-matter-density (GMD) in various cortical and subcortical brain regions. MP2RAGE seemed slightly less prone to false positive results when comparing data acquired with different RF coils and yielded superior segmentation of deep GM structures. With the 12-channel coil, MP-RAGE was superior in detecting age-related changes, especially in cortical structures. Most differences between both sequences became insignificant with the 32-channel coil, indicating that the MP2RAGE images benefited more from the improved signal-to-noise ratio and improved parallel-imaging reconstruction). A possible explanation might be an overestimation of the GM compartment on the MP-RAGE images. In view of substantial effects obtained for all parameters, careful standardization of the acquisition protocol is advocated. While the current investigation focused on aging effects, similar results are expected for other VBM studies, like on plasticity or neurodegenerative diseases. This work has shown that voxel-based methods are sensitive to subtle structural brain changes, independent of imaging modality and scanning parameters. In particular, the studies investigated and discussed the analysis of T1- and diffusion weighted images with VBM and TBSS in the context of dehydration, blood serum sensitive biomarkers and aging were discussed. The major goal of these studies was the investigation of the sensitivity of voxel-based methods. In conclusion, sensitivity and accuracy of voxelbased methods is already high, but it can be increased significantly, using optimal hardand software parameters. It is of note, though, that these optimizations and the concomitant increase of detection sensitivity could also introduce additional confounding factors in the imaging data and interfere with the latter preprocessing and statistical computations. To avoid an interference e.g. originating from physiological parameters, a very careful selection and monitoring of biological parameters of each volunteer throughout the whole study is recommended. A potential impact of scanning parameters can be minimized by strict adherence to the imaging protocol for each study subjectwithin a study. A general increase in detection sensitivity due to optimized parameters selection in hard- and/or can not be concluded by the above mentioned studies. Although the present work addressed some of those issues, the topic of optimal selection of parameters for morphometric studies is still very complex and controversial and has to be individually decided. Further investigations are needed to define more general scanning and preprocessing standards to increase detection sensitivity without the concomitant amplification of confounding factors.
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Vigneau-Roy, Nicolas. "Structure et fonction du cerveau : lien entre la densité vasculaire régionale et l'amplitude du signal BOLD." Mémoire, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6370.
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Résumé: L’Imagerie par Résonance Magnétique fonctionnelle est devenue un des outils principaux pour mesurer l’activité cérébrale chez l’Homme de façon non-invasive. Le type de séquence plus fréquemment utilisé à ces fins est le signal dépendant du niveau d'oxvgène sanguin (BOLD signal) car il reflète les changements hémodynamiques associés à l’activité cérébrale et offr l’avantage d'être relativement facile à mesurer. Cependant, cette mesure est dépendante du niveau de désoxyhémoglobine, présent dans les veines. L'architecture structurelle de ces dernières varie considérablement d'une région du cerveau à l'autre et cela fait en sorte qu'il est ardu de savoir si les différences inter-régionales sont dues à des différences au niveau de l’activité neuronale ou de la structure vasculaire. C'est pour répondre à cette question que nous avons observé la relation entre les variations régionales de densité vasculaire (VAD) et l’amplitude du signal BOLD au repos et en présence d'un stimulus. Nous avons implémenté une méthode de segmentation des veines pour des images en pondération de susceptibilité (SWI). Nous avons également utilisé une méthode de segmentation des tissus (Morphométrie Basée sur les Voxels (VBM )) pour séparer les tissus et calculer une mesure de densité de matière. Nous avons trouvé qu'indépendamment de la taille des voxels, les variations régionales d'amplitude du signal BOLD au repos et du signal évoqué par une tâche sont mieux corrélées avec la VAD qu'avec la densité de matière grise. En utilisant un modèle linéaire général, nous avons observé qu'une grande partie des variations régionales au repos pouvait être modélisée par la VAD. En somme, nos résultats suggèrent que le signal BOLD au repos est intimement relié à la structure vasculaire. Utiliser la densité vasculaire afin de calibrer les mesures d'amplitude du signal BOLD au repos nous permettra d'interpréter de façon plus précise et d'obtenir de meilleures informations sur les différences observées entre plusieurs groupes de sujets et de patients. // Abstract: Functional Magnetic Resonance Imaging (fMRI) has become one of the primary tools used for non-invasively measuring brain activity in humans. For the most part, the blood oxygen level-dependent (BOLD) contrast is used, which reflects changes in heinodynamics associated with active brain tissue. The main advantage of the BOLD signal is that it is relatively easy to measure and thus is often used as a proxy for comparing brain function across population groups (i.e. control vs. patient). However, it is particularly weighted towards veins whose structural architecture is known to vary considerably across the brain. This makes it difficult to interpret whether differences in BOLD between cortical areas reflect true differences in neu-ral activity or vascular structure. We therefore investigated how regional variations of vascular density (VAD) relate to the amplitude of resting-state and task-evoked BOLD signals. To address this, we first developed an automated method for segmen-ting veins in images acquired with susceptibility weighted imaging (SWI), allowing us to visualize the venoms vascular tree across the brain. In 19 healthy subjects, we then applied Voxel-Based Morphometry (VBNI) to Ti-weighted images and compu-ted regional measures of gray matter density (GNID). We found that, independent of spatial scale. regional variations in resting-state and task-evoked fNIRI amplitude was better correlated to VAD compared to GRID. Using a general linear model (GLNI). it was observed that the bulk of regional variance in resting-state activity could be modelled by VAD. Taken together, our results suggest that resting-state BOLD signals are signifi-cantly related to the underlying structure of the brain vascular system. Calibrating resting BOLD activity by venous structure may result in a more accurate interpreta-tion of differences observed between cortical areas and/or individuals.
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Koch, Amelie [Verfasser], and Göran [Akademischer Betreuer] Hajak. "Morphologische Veränderungen bei Patienten mit chronischem Tinnitus - Eine Studie mit voxelbasierter Morphometrie (VBM) / Amelie Koch. Betreuer: Göran Hajak." Regensburg : Universitätsbibliothek Regensburg, 2011. http://d-nb.info/1023312298/34.
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Schröder, Chantal [Verfasser], and Andreas [Akademischer Betreuer] Jansen. "VBM-Studie zum Einfluss endogener sowie exogener weiblicher Sexualhormone auf die zerebrale Morphometrie / Chantal Schröder ; Betreuer: Andreas Jansen." Marburg : Philipps-Universität Marburg, 2020. http://d-nb.info/1211086399/34.
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Epalle, Thibaut. "Suivi de l'état viable non cultivable de souches de Legionella pneumophila soumises à différents stress (thermique ou chloré) : Evaluation de leur pouvoir pathogène." Thesis, Saint-Etienne, 2015. http://www.theses.fr/2015STET001T/document.
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Legionella pneumophila, l’agent responsable de la légionellose est transmissible à l’Homme par les aérosols environnementaux et infecte les macrophages pulmonaires. Après l’exposition à différents stress L. pneumophila est capable de d’entrer dans un état Viable Non Cultivable (VBNC) qui semble être une stratégie de survie. L’objectif de nos travaux était d’étudier l’état VBNC de différentes souches de L. pneumophila après des traitements thermique et chimique et d’évaluer le pouvoir infectieux des formes VBNC envers les macrophages et les cellules épithéliales alvéolaires. Nous avons étudié les profils physiologiques de L. pneumophila de trois souches différentes. Les résultats montrent que pour chaque souche 3 populations peuvent être identifiées, les légionelles viables cultivables, les VBNC et les bactéries mortes. Lorsque soumises aux stress, chaque souche possède un profil physiologique propre et la présence ou non de bactéries VBNC était dépendante du traitement appliqué et de la souche utilisée. La deuxième partie fut relative à l’étude des traitements thermiques de 70°C pendant 30 min et des chocs au dioxyde de chlore de 4, 6 et 7 mg/L pendant 60 min à température ambiante sur ces VBNC. Aucune légionelle VBNC n’est capable de se développer au sein des cellules et aucune croissance sur milieu BCYE n’a été observée après co-culture. La suite de notre étude a été d’étudier le comportement, envers les macrophages, de L. pneumophila revivifiées après culture sur amibes. Les résultats montrent que les légionelles VBNC induites par choc thermique et revivifiées par co-culture sur Acanthamoeba polyphaga sont capables d’infecter de nouveau les macrophages. En conclusion, ces résultats suggèrent que: (i) les formes VBNC de L. pneumophila ne sont pas spontanément infectieuses pour les macrophages et les cellules épithéliales alvéolaires in vitro et (ii) elles peuvent devenir pathogènes pour les cellules humaines après revivification préalable sur A. polyphagaLegionella pneumophila, the causative agent of legionellosis is transmitted to human through aerosols from environmental sources and invades lung’s macrophages. It also can replicate within various protozoan species in environmental reservoirs. Following exposures to various stresses, L. pneumophila enters a Viable Non Cultivable state (VBNC) which is likely to be a survival strategy. The objective of our work was to study the VBNC forms of several strains of L. pneumophila serogroup 1 obtained after thermal and chemical treatments and to evaluate the infectivity of these VBNC forms against macrophages and alveolar epithelial cells. First we studied the physiological patterns of the three different strains (Philadelphia GFP 008, 044 clinical and environmental RNN). For all strains we observed the presence of VBNC bacteria in the native (non stressed) state. The results show that for each strain, three populations of Legionella can be identified: viable and culturable, VBNC and dead cells. Once submitted to the various stresses, we observed that each strain had its own physiological pattern and the presence (or not) of VBNC bacteria was dependent on the applied treatment and the strain used. The second part was related to the study of the pathogenicity of these VBNC forms against macrophages or epithelial cells. The study focused on heat shock treatment at 70°C for 30 min and chlorine dioxide treatment at 4, 6 and 7 mg/L for 60 min at room temperature. The results show that no Legionella VBNC forms were able to grow within the cells and no growth on BCYE medium was observed after co-culture. Then we investigated the behavior of L. pneumophila resuscitated after culture on ameba within macrophages. The results shows that Legionella VBNC induced by heat shock treatment and resuscitated by Acanthamoeba polyphaga co-culture are able to infect macrophages. In conclusion, these results suggest that: (i) the VBNC forms of L. pneumophila are not infectious for macrophages and alveolar epithelial cells in vitro and; (ii) they can be pathogenic for human cells after revivification by an amoeba (A. polyphaga)
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Rao, Aishwarya Pradeep, and Aishwarya Pradeep Rao. "Plant Antimicrobials: Inactivation of Foodborne Pathogens or Induction into the VBNC State and Their Effects on the Sensory Properties of Organic Romaine Lettuce." Thesis, The University of Arizona, 2017. http://hdl.handle.net/10150/626401.
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This project consisted of three studies: the first study investigated whether plant-based antimicrobials inactivate foodborne pathogens or induce them to go into the VBNC state in vitro and on romaine lettuce; the second study focused on sensory analysis of organic leafy greens treated with plant antimicrobials in the wash water; and the third study examined the novel concept of applying antimicrobials via edible films.
The inert metabolic state of Viable but Non-Culturable (VBNC) that some pathogens can go into is gaining importance in the food and health industries. It is a state in which bacteria do not grow on lab based media but can cause disease in a human host. Foodborne pathogens that can go into VBNC are of immense concern since they can result in false negatives, leading to an outbreak if consumed by the public. The state of VBNC can be triggered by the presence of stress factors that includes chemicals such as sanitizers and antimicrobials. The objective of the first study was to determine whether plant-based antimicrobials inactivate the foodborne pathogens Salmonella enterica serovar Newport, Escherichia coli O157:H7 and Listeria monocytogenes or induce them to go into the VBNC state in vitro and on romaine lettuce.
This was done by using selective media and fluorescence microscopy to confirm the viability of the pathogens. Organic iceberg lettuce inoculated with S. enterica, E. coli O157:H7 or L. monocytogenes was dip-treated in one of the following solutions: 0.1%, 0.3%, and 0.5% of essential oils or their active components; 3 and 5% of one of the plant extracts, hydrogen peroxide or chlorine for 2 min and stored at refrigeration temperature (4°C). Samples were taken on days 0, 1, and 3, for enumeration of survivors. The reductions in bacterial populations ranged from 2-6 log CFU/g. Oregano oil and its active component carvacrol were seen to be most effective in reducing the bacterial populations to below detectable limits on day 0. All the treatments reduced Listeria populations to below detectable limits by day 1. It was generally seen that citral showed more potent antimicrobial activity as compared to lemongrass oil against Listeria. The fluorescence microscopy results also correlate with the plating results. The dead cells fluoresced orange/red and the viable cells fluoresced green.
The second study focused on sensory analysis of organic leafy greens treated with plant antimicrobials in the wash water. The objective of the second study was to a) evaluate panelists’ responses to changes in the sensory attributes of romaine lettuce treated with plant antimicrobials added to the wash water b) identify preference liking of the panelists to leafy greens washed with various essential oils and plant extracts and c) identify and evaluate the effects of these antimicrobials on the color and texture of the treated leafy greens.
Organic romaine lettuce was washed with various plant antimicrobials in tap water for 2 min and stored at 4°C for 20-24 h before performing sensory evaluation and measuring changes in physical properties (color and texture) of leafy greens. A randomized block design was used with 75 panelists. The sensory attributes of the samples, which included pungency, browning, bitterness, off-odor, and sourness were evaluated using a 5 point hedonic scale. The preference liking was evaluated for aroma, color, freshness, mouthfeel, flavor, and overall acceptability using a 9-point hedonic scale where 9 was extremely liked and 1 not liked at all. The color analysis was done using the CIE L*a*b* coordinates and the texture was analyzed using a texture analyzer. Lettuce treated with 7% olive extract and 3% apple extract had a higher likelihood of being purchased and the least likely to be purchased treatments were oregano oil and a combination of oregano oil and grapeseed extract. As per the preference liking, lettuce treated with 7% olive extract and 0.1% citral had a higher overall acceptability. The least acceptable treatments were those of oregano oil and clove bud oil. The color of the samples was affected the least by olive extract and lemongrass oil, with oregano oil and carvacrol showing changes in the color. Similarly, for the texture analysis, it was seen that lettuce treated with 0.1% citral (890.0±79.5 N) was the least affected and 0.1% oregano treated samples were the most affected requiring less force (635 N) to crush the samples.
We know that essential oils are well known for their potent fragrances and flavor imparting properties. The second study also indicated that the direct exposure of leafy greens to the antimicrobials may be less preferred and so the novel concept of applying antimicrobials via edible films was experimented with in the third study. Edible films are thin layer films made using the pulp of edible plant parts or biopolymers such as chitosan. Our films were made of fruit and vegetable pulp and contained the active components of plant antimicrobials. The objective of the third study was to a) evaluate panelists’ responses to changes in the sensory attributes of romaine lettuce treated with plant antimicrobials added to edible films b) identify preference liking of the panelists to leafy greens treated with various edible films and c) identify and evaluate the effects of these edible films on the color and texture of the treated leafy greens.
The edible films were added to bagged lettuce. Edible films were made from tomato, apple, or carrot pulp which included 0.5%, and 1.5% of carvacrol or cinnamaldehyde. Similar parameters were evaluated with these samples. Romaine lettuce treated with apple films had a higher likelihood of being purchased in comparison to other films, with lettuce treated with films containing 1.5% cinnamaldehyde and the control films being the most to be purchased. The least likely to be purchased treatments were those of the tomato films, specifically the films containing 1.5% cinnamaldehyde. The lettuce treated with carrot films had a higher acceptance rating as compared to other films, with films containing 1.5% cinnamaldehyde and the control films being the highest. The color analysis results indicate that the films containing cinnamaldehyde had the least adverse effects. The cinnamaldehyde containing films also needed lower force to crush the leaves, indicating more firmness or crispiness as compared to those containing carvacrol.
The results from the three studies are useful in not only helping to decide which plant antimicrobials can be used as potential sanitizers in the organic industry but also provide insight into which treatments are preferred by consumers and will not affect the marketability of the leafy greens.
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DI, TORO MARIA ROSARIA. "Biodiversity of Dekkera/Brettanomyces in Apulian wines: isolation, characterization of representative biotypes and assessment of control strategies based on biotechnological resources management." Doctoral thesis, Università di Foggia, 2015. http://hdl.handle.net/11369/337553.
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ABSTRACT
BACKGROUND
Among all the possible microbial contaminations of wine, development of Brettanomyces bruxellensis yeast is the most dreaded by winemakers. Indeed, growth of yeasts belonging to Dekkera/Brettanomyces during wine manufacturing, can seriously affect the quality of the final product, especially during aging.
Spoilage yeasts of the genus Brettanomyces or its teleomorph Dekkera are well adapted to survive during the winemaking process, due to their ethanol tolerance and relative resistance to the normal concentrations of sulphur dioxide found in wine.
To prevent the development of this yeast in wine, it is important to know the biodiversity of Brettanomyces bruxellensis. A more detailed study of these aspects could help winemakers to learn more about this yeast and to implement preventive and fighting measures to try to reduce the economic losses caused by B. bruxellensis.
AIM OF THE STUDY
The specific objectives of this work were to isolate Brettanomyces strains from several wineries located in Puglia and to characterize representative biotypes, in order to evaluate control strategies based on biotechnological resources management.
MATERIAL and METHODS
Yeasts of the genus Brettanomyces were selected in tank, barrel and fermenting must of several Apulian wines. The yeast strains were identified and genetically characterized using restriction pattern analysis of the internal transcribed spacer region (5.8S-ITS), species-specific primers and restriction analysis. Biodiversity of selected B. bruxellensis strains was studied with Sau-PCR. Potential spoilage and VBNC behavior of different biotype were studied with gas chromatograph and flow cytometry.
The cells of Brettanomyces were quantified in wine with Real Time PCR. To reduce the volatile phenols in wine and the growth of Brettanomyces bruxellensis different preparations of yeast cell wall and chitosan, respectively, were used.
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Сиром'ятникова, Оксана Валеріївна, and Р. В. Муравльова. "Особливості оцінки ефективності діяльності промислового підприємства." Thesis, НТУ "ХПІ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/25951.
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Чернова, В. В., В. В. Чернова, and V. Chernova. "Контролінг в управлінні вартістю підприємства." Diss., Одеський національний економічний університет, 2017. http://dspace.oneu.edu.ua/jspui/handle/123456789/6687.
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У дисертаційній роботі обґрунтовано теоретичні положення та практичні рекомендації щодо управління вартістю підприємств на основі впровадження інструментів контролінгу. Досліджено концептуальні засади контролінгу та сутність управління вартістю підприємства. Проаналізовані існуючі методи оцінки вартості підприємства, доведена доцільність застосування інтегрованих методів та індикаторів EVA, CVA, CFROІ у вартісно-орієнтованому управлінні (VBM), обґрунтовано необхідність побудови системи контролінгу для оцінки впливу управлінських рішень на індикатори вартості. Здійснено аналітичне оцінювання сучасного стану та перспектив розвитку підприємств–виробників КПП України. Доведено, що основним впливаючим фактором на показники вартості таких підприємств є біржова ціна основного матеріалу. Запропоновано використання елементів інструментальної бази контролінгу у вигляді інформаційно-аналітичної платформи, яка дозволяє оцінити ефективність менеджменту в управлінні вартістю підприємства з урахуванням впливу біржової ціни на основний матеріал. Надані методичні рекомендації з проектування системи планування, управлінського обліку, звітності та оцінювання ефективності діяльності підприємства у моделі VBM.В диссертационной работе рассмотрены теоретические основы и практические рекомендации по управления стоимостью предприятий на основе внедрения инструментов контроллинга. Обоснована необходимость построения системы контроллинга в стоимостно-ориентированной модели менеджмента (VBM) для оценки влияния управленческих решений на показатели стоимости. Проанализированы существующие методы оценки стоимости предприятия, доказана целесообразность применения в VBM индикаторов EVA, CVA, CFROI, которые предложено использовать в интегрированном анализе. Проведен анализ современного состояния и перспектив рынка предприятий производителей КПП. Доказано, что основным воздействующим фактором на показатели стоимости таких предприятий является биржевая цена основного материала. Предложена агрегация систем планирования, управленческого учета и управленческой отчетности в информационно-аналитическую платформу, которая построена на принципах контроллинга и направлена на мониторинг изменений факторов стоимости предприятия с учетом влияния биржевой цены на основной материал. Даны методические рекомендации по проектированию системы планирования, управленческого учета, отчетности и оценки эффективности деятельности в VBM.
The dissertation is devoted to the study of theoretical, methodical and organizational-practical principles of value based management and adaptation of controlling tools to the needs of industrial enterprises. The study covers the value based controlling concept and its implementation in business practice. The building of controlling system in frameworks of the value-based management (VBM) is needed for the evaluation of the influence of management decisions on value indicators of business (company). The analysis of existing methods for estimating the value of the enterprise has demonstrated the feasibility of using integrated methods and indicators EVA, CVA, CFROI in the value-based management. The full picture of decision making can be got if all indicators are used in the integrated analysis, where EVA – shows the ability of the business to make a profit, CVA – sufficiency of cash flow for business activity, CFROI – the size of business profitability in percent. The focus of the research was given on cable and wires manufacturers of Ukraine. It assessed current condition, dynamics, problems, possibilities and potential opportunities for their development. The hypothesis was proved, that main factor affecting the indicators of these enterprises value is the exchange price of the main material. The work presents scientifically-methodical approach to design of value-based controlling system. It allows to determine the key factors of value and the degree of their influence on value indicators – at the diagnostics phase, and to determine the basic rules of the controlling concept – the rules of results, processes and coordination – at the planning and engineering phase. Rules of results reveal what is the criterion of performance of tasks at each stage - and the scale of their optimality. Rules of processes concerned the nature and content of activities, interpretation of information flow about internal and external business processes, coordination rules – define the interaction both between the general goals and objectives, as and within them. Controlling system design in value based management model will provide a clear link enterprise planning and current activities with cost factors; integrate and coordinate all the administrative processes of the enterprise to increase the value, to promptly respond changes in the external and internal environment, taking the deviations from the set objectives in considering with the interests of owners and investors, avoiding manipulation by management. The proposed information and analytical platform is a result of aggregation of planning, management accounting and management reporting systems. It’s based on the principles of controlling and aims to monitor changes in the factors and value indicators taking into consideration the impact of the stock-exchange prices on the main material. Methodical recommendations on systems planning engineering, management accounting, reporting and evaluation of the enterprise's working in the VBM model were given. An information model for estimating the value of an enterprise has been developed. It considers the dividends that must be accrued, and those that can actually be paid. This will allow to assess effectiveness of management in solving strategic problems and to provide the ability to plan and monitor the deviations of indicators from target values for the generation relevant management decisions.
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Noack, Henrike Anne [Verfasser]. "Quantitative EEG-Analyse bei Parkinson Patienten ohne Demenz in Korrelation zu strukturellen MRT-Veränderungen : eine VBM-Studie / Henrike Anne Noack." Gießen : Universitätsbibliothek, 2014. http://d-nb.info/1068590203/34.
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Lima, Luiz Cesar dos Santos. "Proposta de um método de análise da viabilidade dos modais para o transporte do carro de combate VBC Leopard 1A5BR." Universidade Tecnológica Federal do Paraná, 2012. http://repositorio.utfpr.edu.br/jspui/handle/1/599.
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A Mobilização Nacional é um conjunto de atividades que visa capacitar o Brasil a planejar e executar ações no campo da Defesa Nacional para garantir a segurança e a soberania do país. Quando esta for decretada pelo Estado, os órgãos que fazem parte do Sistema de Defesa Nacional devem estar preparados e equipados para executarem suas funções. O Exército Brasileiro, um desses órgãos, no ano de 2006, adquiriu 250 viaturas blindadas de combate, das quais 216 para serem distribuídas em suas unidades de cavalaria no território brasileiro. O objetivo desse estudo é apresentar a melhor alternativa logística de transporte para o deslocamento desses carros de combate em uma organização militar, a partir de um determinado cenário, com menor custo e/ou tempo. Para atingir o objetivo foram realizadas consultas por meio de entrevistas e correspondências com especialistas em transporte, transporte militar e viaturas blindadas. As consultas possibilitaram definir as principais vantagens e desvantagens dos modais de transporte e os fatores relevantes no transporte de viaturas blindadas, permitindo a formulação da rede de transporte e elaboração de um instrumento de viabilidade dos modais de transporte (quadro de verificação) a serem aplicados às rotas de transporte. Um problema de transporte das viaturas blindadas, a partir de um cenário hipotético, foi resolvido por meio de um modelo matemático tendo como objetivo a minimização de custo ou tempo. Concluiu-se que o modelo matemático é uma ferramenta que pode auxiliar a tomada de decisão no transporte das viaturas blindadas, mas a melhor alternativa irá depender da adequada análise dos modais de transporte disponíveis e da correta formulação e aplicação do instrumento de viabilidade dos modais de transporte.The National Mobilization is a set of activities that aims to enable Brazil to plan and execute actions in the field of National Defence toensure the security and sovereignty of the country. When it is ordered by the state organs that are part of the System of National Defense must be prepared and equipped to execute its functions. The Brazilian Army, one of these agencies, in 2006, purchased 250 armored combat vehicles, of which 216 to be distributed among their cavalry units in Brazil. The aim of this study is to present the best alternative transportation logistics to carry these tanks in a military organization, from a given scenario, with lower cost and / or time. To achieve the goal consultations through interviews and correspondence with experts in transport, military transport and armored vehicles. The consultations allowed to define the main advantages and disadvantages of transportation modes and factors relevant to transport armored vehicles, permitting the formulation of the transport network and development of an instrument feasibility of transportation modes (check list) to be applied to routes of transport. A problem of transporting armored vehicles, from a hypothetical scenario, was solved by a mathematical model with the objective of minimizing cost or time. It was concluded that the mathematical model is a tool that can aid decision making in the transport of armored vehicles, but the best choice will depend on the proper analysis of the modes of transportation available and the correct formulation and application of the instrument feasibility of transportation modes.
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Ducret, Adrien. "Viabilité et cultivabilité de L. Pneumophila : étude des mécanismes impliqués dans la récupération de l'aptitude à former des colonies." Aix-Marseille 2, 2009. http://www.theses.fr/2009AIX22105.
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Legionella pneumophila est une bactérie pathogène responsable de la légionellose qui se transmet par voies aériennes à partir de sites industriels ou naturels générateurs d'aérosols (installation d'eau chaude sanitaire, tours aéroréfrigérantes,. . . ). Actuellement le dénombrement et l'isolement de L. Pneumophila sont régis par une norme basée sur l'utilisation de culture gélosés. Cependant, comme de très nombreuses bactéries Gram négatif, Legionella pneumophila serait capable de passer, en condition de carence ou de stress, dans un état viable mais non cultivable (VBNC). Au cours de cette étude, nou avons montré que les différents traitements biocides classiquement utilisés pour éradiquer L. Pneumophila dans les installations industrielles, induisaient la formation de cellules VBNC, déterminées à travers l'utilisation de marqueurs de viabilité et du milieu de culture de référence. Cependant, l'analyse fine des marqueurs de viabilité estimée pour chaque cellule viable détectée montre que celles-ci présentent une altération progressive des différents descripteurs de viabilité utilisés à mesure que la concentration en biocide augmente. En supposant dans un premier temps, que la perte de cultivabilité des cellules VBNC soit potentiellement due au stress oxydant généré lors que l'étalement, nous avons cherché à optimiser le milieu de référence. Au cours de cette étude de nombreux composés (antioxudants, métaboliques. . . ) ont ainsi été identifiés comme étant bénéfiques à la restauration de la cultivabilité d'une fonction de la population après un stress mais aussi, et de manière intéressante, au cours de la croissance. La co-existence de deux sous population cultivables (sur le milieu de référence ou supplémenté) dont la proportion relative évolue au cours du temps, soulève donc à ce jour, un certain nombre de questions quant à l'origine et à la pertinence physiologique de chacune des deux populations. Pour des raisons techniques, ces questions ne pourrons être résolues qu'à travers l'utilisation de méthodes centrées sur l'individu et non plus sur la réponse globale d'une population. Dans ce sens, nous avons initié le développement d'une chambre d'observation et d'un système de fluidique qui permet aujourd'hui un suivi en temps réel de la viabilité des cellules observé et de leur devenir au cours du temps ou au cours d'un stress tout en observant in fine leur capacité respective à former une colonieLegionella pneumophila is the causative agent of Legionellosis transmitted by air from industrial or natural aerosols (installation of hot water, cooling towers. . . ) Currently standard procedure that uses the agar cultur media governs the detection and isolation of L. Pneumophila. However, like many Gram-negative bacteria, Legionella pneumophila is able to enter in a viable state but non culturable (VBNC) during starvation or stress conditions. In this study, we showed that the different treatment biocides traditionally used to eradicate. L. Pneumophila in industrial plants, induced the formation of VBNC cells, determined using viability markers and reference agar medium (BCYE). However, detailled analysis of the viability markers shows that they have a progressive detetioration of the viability of different descriptors used as the biocide concentration increases. Assuming initially that the loss of culturability of VBNC cells is potentially due to oxidative stress generated during spreading, we sought to optimize the reference medium. During the study many compounds (antioxidants, metabolic. . . ) have been identified as benefical to the restoration of culturability for a fraction of the population after stress but also, interestingly, during growth. The co-existence of two populations (culturable on the reference medium or the supplemented medium) with the relative proportion changes over time, raises to date, a number of questions about the origin and physiological relevance of each of the two populations. For technical reasons, these issues can be resolved only with methods focused on the individual rather than on the overall response of a population. In this sense, we initiated the development of an observation chamber and a fluidic system that now allows as realtime monitoring of cell viability observed and their evolution over time or during a stress while observing ultimately their respective ability to form a colony
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Blouw, Mbuyiselo Edwin. "A study of the use of value based management (VBM) by multinational entities in the Eastern Cape motor industry cluster (ECMIC)." Thesis, Nelson Mandela Metropolitan University, 2005. http://hdl.handle.net/10948/421.
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Management’s response to shareholders’ return on investment as a priority occurs in an increasingly dynamic environment. Accompanying these activities is the need to realign responsibilities and to allocate scarce resources effectively. This is done in order to ensure that companies achieve global competitiveness and increase shareholders’ return on investment. Against this backdrop, local industry needs to find new methods or strategies in order to achieve world-class competitiveness, and to be able to access foreign investment. One way to achieve these goals is through Value Based Management (VBM). The objective of this study is to evaluate the strategic intent of Multinational Entities in applying VBM to increase shareholders’ return on investment. Based on the study, certain factors are critical to ensure the success of VBM. A postal survey to managers in the motor manufacturing and component manufacturing companies was conducted to check the managers’ familiarity with VBM, and their scope, and usage of VBM; and, based on the finding, to evaluate the impact of VBM on companies’ results. The empirical finding was compared with a literature review, and the following findings were made: There is a strong understanding and application of the VBM principle on the part of local entities with Foreign Direct Investment (FDI); Departmental performance is critical to an entity’s overall performance; Based on the study, 23 per cent of the respondents use Economic Value Added (EVA) as an internal reporting measure, and an average of 19 per cent use other metrics; A total of 89 per cent of respondents indicated that they strongly agree with the use of incentives for motivation. The above-mentioned points were covered by means of 4-M framework ― that is: Measurement, Management, Motivation, and Mindset.
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Gryga, Martin. "Strukturelle und funktionelle Hirnveränderungen nach fünf Tagen komplexen motorischen Lernens." Doctoral thesis, Universitätsbibliothek Leipzig, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-109708.
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Long-term motor skill learning has been consistently shown to result in functional as well as structural changes in the adult human brain. However, the effect of short learning periods on brain structure is not well understood. In the present study, subjects performed a sequential pinch force task (SPFT) for 20 min on 5 consecutive days. Changes in brain structure were evaluated with anatomical magnetic resonance imaging (MRI) scans acquired on the first and last day of motor skill learning. Behaviorally, the SPFT resulted in sequence-specific learning with the trained (right) hand. Structural gray matter (GM) alterations in left M1, right ventral premotor cortex (PMC) and right dorsolateral prefrontal cortex (DLPFC) correlated with performance improvements in the SPFT. More specifically we found that subjects with strong sequence-specific performance improvements in the SPFT also had larger increases in GM volume in the respective brain areas. On the other hand, subjects with small behavioral gains either showed no change or even a decrease in GM volume during the time course of learning. Furthermore, cerebellar GM volume before motor skill learning predicted (A) individual learning-related changes in the SPFT and (B) the amount of structural changes in left M1, right ventral PMC and DLPFC. In summary, we provide novel evidence that short-term motor skill learning is associated with learning-related structural brain alterations. Additionally, we showed that practicing a motor skill is not exclusively accompanied by increased GM volume. Instead, bidirectional structural alterations explained the variability of the individual learning success.
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Paraguassú, Aroldo Montenegro Duarte. "Vantagem competitiva na indústria de reparos automotivos : abordagem dialógica da visão baseada no mercado (VBM) e da visão baseada no mercado em recursos (VBR)." Universidade de Fortaleza, 2008. http://dspace.unifor.br/handle/tede/79454.
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Made available in DSpace on 2019-03-29T23:20:35Z (GMT). No. of bitstreams: 0
Previous issue date: 2008-11-28In the area of strategy, much is discussed about the potential of complementary or antagonism of MBV - Market-based View (Competitive Strategy) and RBV - Resources-based View. However, few studies have addressed the consideration of these perspectives, expanded in a dialogical approach to the principles of Complex Reasoning. This study aims to answer a question on exactly this point: How does dialogical approach influences the understanding of competitive advantage, according to MBV and RBV? In this sense, the study provides a framework in which competitive advantage is understood according to a dialogical approach of MBV and RBV. To that end, there was a case study in two phases, the strategic group of independent auto-centers in the automotive repair segment of Fortaleza / Brazil. In the first phase, were interviewed 15 experts of the sector in two meetings of focus groups, from which emerged six inductor themes related to competitive advantage. These themes guided the second phase of the interviews with entrepreneurs / managers of 13 illustrative cases. The illustrative cases were important to describe mutual inter-relations that show situations up where the themes, it prays antagonistic, that inhibit and reduce his effects, it prays if they complement in the almost passive form and even they compete being stimulated and done so that the competitive advantage is enlarged. The main contribution of this study to propose a framework that aims to facilitate the understanding of this new approach and can be understood as an array of static position in terms of a dialogical vision of competitive advantage in the MBV and RBV.
Na área de estratégia, muito se discute sobre o potencial antagonismo ou complementaridade da VBM - Visão Baseada no Mercado (Estratégia Competitiva) e da VBR - Visão Baseada em Recursos. Poucos estudos, no entanto, se endereçaram para a consideração dessas perspectivas, ampliadas da dimensão concorrente em uma abordagem dialógica segundo a Teoria da Complexidade. O presente estudo visa a responder exatamente a uma questão ligada a este ponto: como a abordagem dialógica influencia na compreensão da vantagem competitiva, segundo a VBM e a VBR? Neste sentido, se propõe a apresentar um framework, no qual a vantagem competitiva seja compreendida segundo uma abordagem dialógica da VBM e da VBR. Para tanto, foi realizado um estudo de caso, em duas fases, no grupo estratégico dos auto-centers independentes do segmento de reparos automotivos de Fortaleza/Ceará/BR. Na primeira fase, foram ouvidas as contribuições de 15 experts do setor em duas reuniões de grupos focais, de onde emergiram seis temáticas indutoras da vantagem competitiva que, na segunda fase, orientaram o roteiro de entrevistas a empresários/gestores de 13 casos ilustrativos. Os casos ilustrativos foram importantes para descrever inter-relações mútuas que evidenciam situações onde as temáticas, ora antagônicas, se inibem e reduzem seus efeitos, ora se complementam de forma quase passiva e mesmo concorrem estimulandose e fazendo com que se amplie a vantagem competitiva. Como principal contribuição deste estudo, ressalta-se a proposição de um framework que pretende facilitar a compreensão dessa nova abordagem e pode ser entendido como uma matriz de posicionamento estática, no que tange a uma visão dialógica da vantagem competitiva, segundo a VBM e a VBR.
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McDougald, S. Diane School of Microbiology & Immunology UNSW. "Regulation of starvation and nonculturability in the marine pathogen, Vibrio vulnificus." Awarded by:University of New South Wales. School of Microbiology and Immunology, 2000. http://handle.unsw.edu.au/1959.4/19118.
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Vibrio vulnificus is a model environmental organism exhibiting a classical starvation response during nutrient limitation as well as a non-culturable state when exposed to low temperatures. In addition to these classic global responses, this organism is an opportunistic pathogen that exhibits numerous virulence factors. This organism was chosen as the model organism for the identification of regulators of the viable but nonculturable response (VBNC) and the starvation-induced maintenance of culturability (SIMC) that occurs when cells are starved prior to low temperature incubation. In order to accomplish this, three indirect approaches were used; proteomics, investigation of intercellular signalling pathways and genetic analysis of regulators involved in these responses. Two-dimensional gel electrophoresis was used to identify proteins expressed under conditions that induced SIMC. It was determined that carbon and long-term phosphorus starvation were important in the SIMC response. V. vulnificus was shown to possess genes, luxS and smcR, that are homologues of genes involved in signalling system system 2 in Vibrio harveyi. Signal molecules were produced upon starvation and the entry to stationary phase in V. vulnificus. Furthermore, a null mutation in smcR, a transcriptional regulator was shown to have pleiotropic effects in V. vulnificus, including up-regulation of numerous virulence factors and a defect in starvation survival and development of the SIMC response. We propose that V. vulnificus possesses a signalling system analogous to that of system 2 in V. harveyi, and that this system is involved in the regulation of stationary phase and starvation adaptation in this organism.
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Bloch, Zdzislaw, and Martin Larsson. "Modeller för Value Based Management : teoretisk och empirisk studie." Thesis, Södertörn University College, School of Business Studies, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-1663.
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Syfte:
Vi vill med vår uppsats öka förståelsen för vad VBM-konceptet kan bidra till för ett företag och visa hur olika VBM-modeller används i praktiken.
Metod:
En teoretisk studie som huvudsakligen baseras på sekundär data där vi sammanställer olika teorier och modeller tillhörande VBM-konceptet samt tidigare forskning. Detta kompletteras med vår egen empiri som består av intervjuer som genomfördes vid två företeg.
Resultat:
Resultatet visar att det inte är något företag som använder sig av flera VBM-mått på olika nivåer. Oftast bestämmer man sig för en modell och använder den till alla nivåer, möjligtvis kompletterar man med mindre nyckeltal. Val av modell är inte det viktigaste utan att man väljer någon modell som gör så att kapitalkostnaden tydliggörs för att säkerställa att intäkterna täcker kapitalkostnaderna.
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Albajara, Saenz Ariadna. "On the association between Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder: A neuroimaging investigation." Doctoral thesis, Universite Libre de Bruxelles, 2020. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/303539.
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Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) are two neurodevelopmental disorders with distinct diagnostic criteria that often co-occur. Although both ASD and ADHD are associated with structural and functional brain abnormalities when compared to typically developing (TD) populations, it is necessary to disentangle the shared and specific abnormalities between these disorders, potentially underlying similarities and differences in their clinical and neurocognitive profiles. The aim of this thesis was to explore the shared and disorder specific functional and structural brain abnormalities between ASD and ADHD. For this purpose, the neural underpinnings of a group of children with ADHD, a group of children with ASD and a group of TD children aged 8 to 12 years old were compared using different neuroimaging techniques. In Chapter 2, the experimental sample included in this thesis was described using multiple clinical and neurocognitive measures. In the first study (Chapter 3), total and regional brain volumes were compared between groups, using voxel-based morphometry. The results of this study showed larger grey matter volume (GMV) in the left precuneus and decreased GMV in the right thalamus in the ADHD group compared to either the TD or the ASD groups, and increased GMV in the right precentral gyrus in the ASD group compared to either the ADHD or the TD groups. In the second study (Chapter 4), white matter microstructure was compared between groups using diffusion tensor imaging derived indices (fractional anisotropy [FA] and mean diffusivity [MD]). Reduced FA (i.e. reduced diffusion directionality) in the genu of the corpus callosum (CC) was found in the ASD group compared to either children with ADHD or TD children, whereas lower FA in the body of the CC was a shared feature between the ADHD and ASD groups. Finally, in the last study (Chapter 5), inhibition-related brain activation was compared between groups during the execution of an inhibition stop-signal task. In children with ADHD, successful inhibition was associated with right inferior parietal activation, whereas right frontal regions were activated in children with ASD. Between-group comparisons disclosed higher middle frontal activation in the ASD group compared to the ADHD or the TD groups. Taken together, our findings provide further evidence contributing to disentangle the shared and specific brain structural and functional abnormalities between ASD and ADHD.Doctorat en Sciences psychologiques et de l'éducation
info:eu-repo/semantics/nonPublished
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Shah, Manoj Kumar. "Characterizing the Impact of Stress Exposure on Survival of Foodborne Pathogens." Diss., North Dakota State University, 2019. https://hdl.handle.net/10365/29389.
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Bacterial pathogens transmitted by the fecal-oral route endure several stresses during survival/growth in host and non-host environments. For foodborne pathogens, understanding the range of phenotypic responses to stressors and the environmental factors that impact survival can provide insights for the development of control measures. For example, the gastrointestinal system presents acidic, osmotic, and cell-envelope stresses and low oxygen levels, but Listeria monocytogenes can withstand these stresses, causing illnesses in humans. Survival/growth characteristics may differ among L. monocytogenes strains under these stressors due to their genetic diversities. Our knowledge of such phenotypic characteristics under bile and salt stresses are inadequate. In this dissertation, variation in growth characteristics was observed among L. monocytogenes strains under bile and osmotic stresses with no evidence of cross-protection, but rather an antagonistic effect was observed with the formation of filaments when pre-exposed to 1% bile and treated with 6% NaCl. This shows that variation in stress adaptability exists among L. monocytogenes strains with the ability to form filaments under these conditions. Similarly, Salmonella survival in soil is dependent on several factors, such as soil, amendment types, moisture, irrigation, and desiccation stress. In this study, the use of HTPP (heat-treated poultry pellets) was investigated as a soil amendment in the survival/growth of Salmonella in soil extracts mimicking runoff events, and in soil cultivated with spinach plants to assess its safety for use for an organic fertilizer. The presence of HTPP in soil increased S. Newport survival with a greater likelihood of its transfer to and survival on spinach plants. Increased microbial loads and rpoS mutant showed decreased growth/survival in soil extracts, however, rpoS was not important for survival in soil under the tested conditions showing possible lack of desiccation stress. These results show that HTPP provided nutrients to the Salmonella for increased growth and survival in soil extracts and soil, respectively, which show that the use of treated BSAAO to soils may still require appropriate mitigation to minimize Salmonella Newport contamination of leafy greens in the pre-harvest environment. Overall, the results in this study increased our understanding of L. monocytogenes and Salmonella phenotypic adaptation to stressful environments.
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Schreiner, Daniela [Verfasser], and Göran [Akademischer Betreuer] Hajak. "Der Einfluss des Val66Met-Polymorphismus des Brain-Derived Neurotrophic Factor (BDNF)-Gens auf die neuronale Plastizität: Eine VBM- und TMS-Studie / Daniela Schreiner. Betreuer: Göran Hajak." Regensburg : Universitätsbibliothek Regensburg, 2011. http://d-nb.info/1023398834/34.
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Nicol, Marion. "Recherche d'outils thérapeutique innovants pour lutter contre la bactérie Acinetobacter baumannii." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMR132/document.
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Acinetobacter baumanii fait aujourd’hui partie des bactéries les plus problématiques dans le monde. Responsable de nombreux pics épidémiques d’infections nosocomiales auxquelles sont associés de forts taux de mortalité, cette bactérie puise sa pathogénie dans de multiples caractéristiques qui lui permettent ainsi d’échapper au système immunitaire de l’hôte et à la plupart des traitements actuels. Capable d’adhérer à de multiples surfaces, A. baumanii persiste dans l’environnement hospitalier à travers un mode de vie communautaire au sein duquel ses capacités de survie sont exacerbées. Chez les espèces du genre Acinetobacter, le mode de vie communautaire peut prendre deux formes distinctes : le biofilm et la pellicule. Dans la première partie de cette thèse, nous avons cherché à discriminer ces deux modes de vie, chez la souche ATCC 17978, par une analyse protéomique à large échelle. Nous avons confirmé la présence de nombreux marqueurs communs aux deux communautés (transporteurs, systèmes de sécrétion, d’acquisition d’ions, adhésines et pili) et mis en exergue des systèmes spécifiquement reliés à la formation du biofilm (pilus Fim, T2SS, T1SS/pompe A1S_0535-38, LPS/LOS, motif capsulaire) et à celle de la pellicule (Gac). Grâce à l’étude de la souche A. baumannii SDF en mode biofilm, qui présente un génome plus compact, nous montrons que très peu de mécanismes moléculaires sont partagés par les deux souches étudiées. Ce résultat témoigne de la difficulté quant au développement d’un traitement dirigé contre les biofilms A. baumannii. Dans une deuxième partie, nous avons testé deux approches pour prévenir et éradiquer les biofilms à A. baumannii. La première a ciblé le Quorum Sensing (QS), système de communication essentielle à la coordination des cellules. Nous avons pu montrer que les acides gras mono-insaturés (acide palmitoléique et acide myristoléique), au même titre que la virstatine, limitait la formation de communautés à A. baumannii en inhibant l’expression du régulateur abaR nécessaire au QS. Dans une seconde stratégie, nous avons finalement évalué l’action antibactérienne et antibiofilm d’un nouveau composé d’origine naturelle : la squalamine. Dans cette étude, nous montrons pour la première fois qu’A. baumannii est capable d’entrer dans un état de dormance (persistant/VBNC) pour survivre à de fortes doses de ciprofloxacine, mais que la squalamine est capable d’éradiquer ces cellules persistantes grâce à des concentrations inférieures à la concentration hémolytiqueToday, Acinetobacter baumannii is one of the most problematic pathogens in the world. This bacterium is responsible for worldwide epidemic outbreaks associated with dramatic mortality rates. It possesses high capacities to evade the immune host system and to resist to numerous available antibacterial agents. A. baumannii is also able to persist into hospital environment due to high adhesion abilities which induce community development. This process is also associated to an enhanced survival rate. In Acinetobacter genus, community modes of lif can take two forms : biofilm and pellicle. In this study on the strain ATCC 17978, we tried to discriminate these two lifestyles by a large scale proteomic analysis. We have confirmed the presence of many common community markers (transporters, ion acquisition secretion systems, adhesins and pili) and highlighted systems specifically related to biofilm (pilus Fim, T2SS, T1SS / pump A1S_0535-38, LPS / LOS, capsular pattern) and pellicle communities. Furthermore the proteomic analysis of an avirulent A. baumannii strain, SDF, in biofilm allowed to highlight peculiar metabolic pathways, specific adhesion determinants but very few markers shared by ATCC 17978. This demonstrated the difficulty in developing a treatment directed against A. baumannii biofilm. Then, we tested different approaches to prevent and eradicate biofilms. The first one targeted the Quorum Sensing system (QS), an essential communication system for cell coordination. We have showed that monounsaturated fatty acids (palmitoleic acid and myristoleic acid), like virstatin prevent the community formation of A. baumannii by inhibiting the expression of the abaR regulator required for QS. In a second strategy, we have evaluated the antibacterial and antibiofilm activity of a new natural compound : the squalamine. We showed for the first time that if ciprofloxacin treatment was able to induce a dormancy population (persistent/VBNCs) in A. baumannii, squalamine was able to eradicate this population of dormant cells
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Perdigao, Cristhiana. "Assessment of horizontal bore drains performance in brown coal mines in the Latrobe Valley." Thesis, Federation University Australia, 2021. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/181877.
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Horizontal bores are essential infrastructures for maintaining the stability of open-pit mine batters. The infiltration of water from large surface catchments during rain events and induced deformation caused by mining activities can cause the build-up of pore water pressures in mine batters, potentially leading to catastrophic slope failures. A field investigation unit containing a camera has been developed to survey long (>300m) horizontal bores. Features observed using the camera along the profile of horizontal bores are discussed. Water flow was quantified by flow meters. X-Ray Diffraction (XRD) was undertaken to investigate the water precipitates within the selected bores. Water flow temperature was recorded to test the hypothesis of a possibility to indicate whether a borehole was draining from the saturated zone or from the surface water through its temperature. The investigations have been conducted to determine the cause of change in the efficiency of horizontal boreholes and find a reliable measure to assess longevity and performance of horizontal drains. Bore efficiency has been defined as the bore functioning as a preferential path for water within the batter to be drained out to reduce the saturated zone and associated pore water pressures within the batter. The results suggest blockages and fractures inside the bores can be considered the leading cause of the change in the efficiency of a bore. Blockages occur because of sediment accumulation and because of coal chunks from internal wall collapses. Internal fractures affect efficiency when they become the water preferred path; thus, retaining water flowing within the batter. The bore’s longevity is considered the period of the bore is considered effective. Water flow measurement is suggested as a reliable measure to assess bores’ longevity.Masters by Research
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BERLINGERI, MANUELA. "Brain dynamics associated with graceful and pathological aging: new morphometric and fMRI evidence." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2010. http://hdl.handle.net/10281/7816.
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In the last decade, graceful aging has often been associated with frontal hyperactivations in working- and episodic long-term memory tasks, a compensatory process, according to some, that allows the best normal olders to perform these tasks at a juvenile level, in spite of the natural cortical impoverishment.
It remains to be established, however, whether the frontal hyperactivation is the only possible neurofunctional manifestation of compensatory processes in halthy aging.
In this thesis I present a systematic investigation of this issue and related issues on pathological aging seen in MCI.
I first re-assessed the results of 23 recent neuroimaging papers on normal aging using a quantitative meta-analytic approach that allowed us to distinguish between task-dependent and task-independent age-related hyperactivations in healthy olders (Chapter 2). In particular, task-independent hyperactivations emerged in the prefrontal cortex (PFC) in line with the results commonly described in international litterature, while task-dependent hyperactivations emerged in brain regions beyond the prefrontal areas.
Further, we investigated more directly the existence of task-specific neurofunctional manifestations of compensatory processes in a new fMRI / VBM study (Chapter 3). In this study, 24 young and 24 healthy elderly participants were compared. Graceful aging was explored by investigating domains where most healthy olders perform like youngers (e.g. lexical-semantic knowledge) and tasks that are typically more challenging, like episodic long-term recognition memory tasks. With voxel-based morphometry we also studied to what extent changes of fMRI activation were consistent with the pattern of brain atrophy. We found that hyperactivations in the group of healthy olders were not restricted to the frontal lobes, rather they presented with task-dependent patterns. Moreover, only hypoactivations did systematically overlap with regional atrophy. On the basis of these results we suggest that compensatory processes associated with graceful aging are not necessarily a sign of early saturation of executive resources, if this saturation was to be represented by a systematic frontal hyperactivation.
The role of the PFC over-recruitment and age-related neurofunctional changes in healthy olders was further investigated in Chapter 4. In particular in this study we reviewed the neurofunctional data collected in the third Chapter in the light of the HAROLD model (Hemispheric Asymmetry Reduction in Olders). Again, the data clearly suggested that the manifestation of age-related neurofunctional changes of functional lateralization in healthy olders is not exclusively restricted to the frontal areas, rather these are distributed across the entire brain volume in a task-related manner.
Finally, in order to better address neurofunctional and neuroanatomical changes in pathological aging and to create a link with theoretical frameworks that describe graceful aging, we compared behavioural, neurofunctional and neuroanatomical data of 24 healthy olders and 9 aMCI patients, challenged with the same lexical-semantic and episodic long-term memory tasks used in Chapter 3. The between groups differences were analysed in the light of our previous findings on the neural pattern of compensatory processes in healthy aging (described in Chapter 3). A systematic pattern emerged: aMCI patients showed over-activations in parts of the task-specific neural networks that are dysfunctional in highly-performing healthy olders, while they under-recruited the task-specific compensatory neural networks typically over-activated by healthy older controls. Moreover, the over-recruitments of areas which became of no use in healthy aging showed a negative correlation with the gray matter density in the medial temporal lobe structures. These results are discussed in terms of lack of neural plasticity in pathological aging.
I conclude my dissertation with chapter 6 where I propose a neurocognitive account of healthy and pathological aging in terms of compensatory processes and neural plasticity.
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Delmaire, Christine. "Exploration in vivo grâce à l'IRM des atteintes fonctionnelles, morphologiques et microstructurelles dans la dystonie." Paris 6, 2007. http://www.theses.fr/2007PA066595.
Full textAbstract:
La dystonie est une pathologie du mouvement dont la physiopathologie est mal connue. Jusqu'à présent, les données de l'imagerie IRM classique étaient décevantes, en particulier dans les dystonies primaires. Le développement de nouvelles techniques d'imagerie offre la possibilité d'explorer cette pathologie de façon plus précise avec les techniques d'analyse morphométrique voxel à voxel (VBM) et d'imagerie du tenseur de diffusion (DTI). Dans ce travail, nous avons utilisé une approche IRM multimodale pour étudier la physiopathologie de la dystonie. A l'aide de l'imagerie par résonance magnétique fonctionnelle, nous avons étudié la sélectivité des représentations neuronales dans le striatum des patients atteints de crampe des écrivains avant et après rééducation fonctionnelle. Nous avons recherché des anomalies structurelles à l'aide de la VBM et utilisé la tractographie pour rechercher une atteinte spécifique des fibres cortico - striatales sensorimotrices chez ces patients. Nous avons combiné une approche anatomique et par tractographie pour localiser le territoire fonctionnel des ganglions de la base lésé dans les dystonies secondaires à des lésions ischémiques. L'ensemble de nos travaux souligne le rôle du circuit sensorimoteur cortex - ganglions de la base - cervelet dans la physiopathologie de la dystonieDystonia is a movement disorder whose pathophysiology is not fully understood. To date, conventional MR imaging was unsuccessful in showing structural abnormality in primary dystonia. New recent imaging techniques, such as voxel based morphometry (VBM) and diffusion tensor imaging (DTI), can be utilized to explore more precisely the pathophysiology of dystonia. In this work, we used several MRI methods to investigate the pathophysiology of dystonia. We used fMRI to determine whether the selectivity of neuronal representation of basal ganglia neurons was altered in the putamen of patients with focal hand dystonia before and after rehabilitation. Using voxel-based morphometry and DTI, we tested the hypothesis that structural or microstructural changes occur in the sensorimotor basal ganglia - cortical circuit in primary focal hand dystonia. Lastly, we combined structural imaging and fiber tracking to determine the functionnal territory of the basal ganglia that is damaged in post stroke dystonia. Overall, our results show that cortico striatal thalamo cerebellar sensorimotor circuit is likely to play a fundamental role in the pathophysiology of the dystonia
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Ledoux, Andrée-Anne. "Neurofunctional and Neuroanatomical Hippocampal Deficits and Connectivity Differences in Schizophrenia Compared to Healthy Control Participants Tested on a Virtual Reality Navigation Wayfinding Task: An fMRI, VBM and Effective Connectivity Study." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24063.
Full textAbstract:
Episodic memory is a key feature in learning. One must remember past events to act upon a present situation. Episodic memory has been reported to be impaired in individuals with schizophrenia. In order to have an intact episodic memory the contextual features (context) must be bound to the content of the event; this mechanism is referred to as contextual binding. It is proposed that binding errors during the encoding process are responsible for episodic memory impairments in schizophrenia. Since the hippocampal formation is considered to be the central element for contextual binding, it is hypothesized that the synaptic disorganization described in this condition results in such a deficit. Moreover, the hippocampus mediates and influences other cognitive processes such as learning and executive functioning. Hence, a contextual binding deficit can have important consequences on cognition, behaviour and emotions. The object of this dissertation was to investigate the neurofunctioning, neuroanatomy and neurofunctional connectivity of the hippocampus while performing a task that utilized contextual binding mechanisms. Since spatial relational processing is part of contextual binding and is rooted in the hippocampal regions, visuospatial navigation, more precisely a wayfinding task, was used as a probe to activate the hippocampus and its associated regions in a group of patients with schizophrenia and matched healthy controls. The following dissertation presents three original research papers contributing to our understanding of the contextual binding and hippocampal deficits in schizophrenia. The first paper investigates the neurofunctioning of the hippocampus with a wayfinding task. The second paper investigates the hippocampal structural abnormality in schizophrenia and how it relates to performance during the wayfinding task. The third paper explores effective connectivity of the hippocampus with other brain regions involved in navigation in schizophrenia with a particular interest in the prefrontal cortex. These three studies demonstrate significant neurofunctional, neuroanatomical, and neurofunctional connectivity deficits in the hippocampus of the patients with schizophrenia compared to a healthy control population. Results of all three papers are further discussed in terms of research and clinical implications.