Tesi sul tema "Microbiology"
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1
Bridson, Eric Youlden. "Quantal microbiology". Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312059.
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Osman, Shaiesta. "Oral microbiology". Thesis, University of North Texas, 1998. http://catalog.hathitrust.org/api/volumes/oclc/48128254.html.
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Lombard, Bertrand. "Les essais inter-laboratoires en microbiologie des aliments Inter-laboratory studies in food microbiology". Phd thesis, INAPG (AgroParisTech), 2004. http://pastel.archives-ouvertes.fr/pastel-00001258.
Testo completoAbstract (sommario):
La validité des contrôles microbiologiques, réalisés dans l'objectif d'assurer la sécurité sanitaire des aliments, nécessite notamment l'obtention de résultats d'analyse fiables. La fiabilité des résultats implique l'utilisation de méthodes validées, mises en œuvre par un laboratoire compétent. Les essais inter-laboratoires permettent de s'assurer, du moins en partie, du respect de ces deux conditions. Cependant, en raison de limites expérimentales, ces essais ne sont pas aussi largement pratiqués dans le domaine de la microbiologie des aliments qu'ils ne le sont dans d'autres domaines analytiques. Dans un premier temps, une revue des documents de référence permet d'établir un état des lieux. Cette revue concerne les trois objectifs que l'on peut assigner à des essais interlaboratoires, à savoir l'évaluation de méthodes d'analyse, celle des laboratoires, et la caractérisation de matériaux de référence. Les documents de portée générale, puis ceux spécifiques de l'analyse des aliments, sont pris en compte, et leur degré d'applicabilité à l'analyse microbiologique des aliments est envisagé. Les référentiels et pratiques propres au domaine d'intérêt traité sont finalement présentés, et les déviations par rapport aux documents généraux analysées. Sur cette base, sont présentées les conditions de mise en œuvre de deux types d'essais interlaboratoires, soit la validation de méthodes dans le cadre d'un projet européen du 4ème Programme Cadre de Recherche & Développement d'une part, et l'évaluation de laboratoires par le biais d'essais d'aptitude pour les Laboratoires Nationaux de Référence sur le lait d'autre part. Les difficultés relatives au protocole expérimental, et liées aux spécificités de la microbiologie, sont mises en exergue. Les modes d'exploitation des résultats, en fonction des objectifs et de la nature, qualitative ou quantitative, de la détermination, sont expliqués. En ce qui concerne la caractérisation de la performance des méthodes d'analyse, l'utilisation de statistiques robustes pour estimer la fidélité des méthodes quantitatives est discutée, ainsi que la façon de caractériser la fidélité comme la justesse des méthodes qualitatives. Sur ces aspects, des perspectives d'amélioration sont envisagées. L'intérêt de l'organisation des essais inter-laboratoires en microbiologie des aliments est ensuite abordé. Celui-ci réside dans l'utilisation que l'on peut faire de ces essais comme éléments incontournables de validation d'une méthode d'analyse et d'évaluation d'un laboratoire afin, d'une part, de crédibiliser ou d'améliorer les méthodes d'analyse normalisées au niveau international, et d'autre part d'estimer l'incertitude de mesure attachée aux résultats d'analyse. Quant aux limites de ces essais, essentiellement d'ordre expérimental, elles tiennent surtout à la nature vivante de l'analyte, et concernent des questions de représentativité.
4
Keltjens, Herman Michiel Antonius Marie. "Microbiology and preventive treatment of root surface caries Microbiologie en preventieve behandeling van tandwortelcariës /". Helden-Panningen : De Gouden Leeuv Drukkerij B.V, 1988. http://catalog.hathitrust.org/api/volumes/oclc/19650028.html.
Testo completoAbstract (sommario):
Thesis (doctoral)--Katholieke Universiteit te Nijmegen, 1988.Text in English with a summary in Dutch. "Een wetenschappelijke proeve op het gebied van geneeskunde en tandheelkunde." Includes bibliographical references.
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Aljohny, Bassam Ouda. "Studies on silicon microbiology". Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548645.
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White, Lorraine. "The microbiology of death". Thesis, University of Sheffield, 2009. http://etheses.whiterose.ac.uk/10361/.
Testo completoAbstract (sommario):
The main aim of this research was an attempt to clarify whether the protagonists of bacterial bone destruction were of a bodily origin as opposed to environmental contamination by soil bacteria and furthermore to demonstrate a time frame for such attack. It is hypothesised that bacteria from the gut commensal flora are responsible for micro-focal destruction (MFD) of bone postmortem that leaves distinctive tunnels. Microorganisms live with a person throughout their life and somewhat ironically after death persist to exploit this now nonoperational substrate. They continue to thrive and without a working immune system are capable of crossing mucosal barriers and invading both soft and hard body tissues. Experimental protocol using pigs as human analogues were combined with archaeological sections of both humans and animals. The experimental research was almost absolute in the conclusion that only the fetal material was free of MFD one year post-mortem; these were entirely skeletonised and open to contamination by soil bacteria. All of the other pigs had suffered some form of attack, including those that had not skeletonised and were not therefore subjected to soil bacteria. The archaeological material tended to support the hypothesis that endogenous gut bacteria were the cause of MFD as both fetal material and animal bones were much less likely to be affected. It is suggested that soil bacteria are not normally accountable for MFD although their involvement cannot be ruled out entirely and they may be involved at a later stage. It is therefore likely that endogenous gut bacteria having access to a dead body immediately are most often the cause of MFD and that this occurs well within the early postmortem period. This has negative implications for biomolecular studies and positive implications for in-situ preservation.
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Kehe, Jared Scott. "Massively parallel combinatorial microbiology". Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127886.
Testo completoAbstract (sommario):
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biological Engineering, May, 2020Cataloged from PDF version of thesis.
Includes bibliographical references (pages 203-216).
Reductionist biology of the 20th century rooted pure culture methods and antibiotics as pillars of humankind's interaction with microbiology, igniting a revolution in medicine and biotechnology. The revolution was not without cost. By overlooking complex biological interactions, it introduced new problems--from the sharp rise in immune disorders to the antibiotic resistance crisis--that 21st century tools must address. While 'omics methods have fundamentally expanded our understanding of biological complexity, we lack a generalized method for measuring how the parts of a complex system, such as the individual strains of a microbial community, interact with each other. In this thesis, I present kChip, a new platform for constructing massively parallel combinatorial arrays of these parts in order to measure their interactions directly. I describe how kChip has been used to reveal patterns in microbial community assembly, unearth minimal microbial combinations with desirable functions, and screen for compounds that potentiate antibiotic activity. I demonstrate how kChip can advance the development of new technologies like microbial consortia and combinatorial drug therapies.
by Jared Scott Kehe.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Biological Engineering
8
Grant, Irene Ruth. "The microbiology of irradiated pork". Thesis, Queen's University Belfast, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335332.
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Robinson, Tobin. "The microbiology of food microenvironments". Thesis, Cardiff University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387586.
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Athukorala, Arachchi Seneviratne Chaminda Jayampath. "Molecular microbiology of candida biofilms". Thesis, Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B4068751X.
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Jeffery, Simon. "The microbiology of arable soil surfaces". Thesis, Cranfield University, 2007. http://dspace.lib.cranfield.ac.uk/handle/1826/2245.
Testo completoAbstract (sommario):
Whilst much is known about the physics and erosion of soil surfaces on a millimetre scale, little is known about the associated microbiology, particularly in temperate arable systems. The vast majority of research regarding microbial interactions at soil surfaces has concerned microbiotic crusts. However, such surface crusts take many years to form and then only in relatively undisturbed soil systems. Arable soil surfaces are subject to relatively extreme environmental conditions, potentially undergoing rapid changes in relation to temperature, water status and solar radiation compared to deeper soil zones. These extreme environmental parameters are likely to have a large impact on the biota found at the arable soil surface when compared to that which occurs in deeper soil zones. Phenotypic profiling using phospholipid fatty acid (PLFA) analysis, microbial biomass, and chlorophyll concentration were used to characterise soil microbial communities with the aim of quantifying differences within the surface layers of arable systems on a millimetre scale. This field work was supported with a series of microcosm-scale studies in which parameters such as length of time between disturbance events and the quality of light reaching the soil surface were controlled. Using microcosms subjected to simulated rainfall and imaged using X-ray computed tomography scanning, the effects of the soil surface microbiota on associated physical properties including structural integrity, porosity, erodibility and hydrological properties were investigated. This research showed that given sufficient time between disturbance events, environmental parameters such as temperature and wet:dry cycling were sufficient to drive the formation of a distinct soil surface phenotype, which appeared to be consistently confined to an order of depth of circa 1 mm. It was notable that the PLFA 16:0 was consistently associated with discrimination between phenotypes between soil surface layers. Calculation of the ratio of fungal to bacterial PLFA biomarkers showed a consistently higher ratio of fungi to bacteria present in the soil surface layer to a depth of circa 1 mm, providing evidence that fungi grow preferentially over the soil surface compared to through the soil matrix. Further investigation demonstrated that light, particularly at photosynthetically active wavelengths, was the main driving factor in the establishment of the distinct soil surface phenotypes. The inocula which drove the formation of such soil-surface community phenotypes, especially the photoautotrophic components, was demonstrated to derive predominantly from aerial sources. Functionally the nature of the soil surface community was found to affect run-off generation and shear strength at the surface. There was no significant impact of the soil surface microbiota on erodibility or water infiltration rates, although whilst distinct surface phenotypes had developed in this experimental circumstance, these were relatively deficient in photoautotrophs compared to other microcosm experiments and field circumstances, and hence extrapolation of this conclusion is not sound. This project has demonstrated that a soil surface ecological niche may exist in other unexplored soil surfaces and highlights the needs to explore this possibility and to examine any associated functional consequence should such niches be found to exist.
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Al-Wajeeh, Khaled Mohsen. "Studies on the microbiology of silicon". Thesis, University of Sheffield, 1999. http://etheses.whiterose.ac.uk/10225/.
Testo completoAbstract (sommario):
A study was made of the interactions between the element silicon, mainly as silicic acid, and various microbial processes. The effect of silicon compounds on fungal growth was determined under both oligotrophic and nutrient-rich (copiotrophic) conditions. Mycelium of Aspergillus oryzae was grown from a spore inoculum added to ultra-pure water (upw) containing silicon compounds, but not in upw alone. Growth of other fungi also only occurred in upw when silicon compounds were added. Increased growth of fungi also followed the addition of silicon compounds to Czapek Dox medium. Silicic acid also increased the protein content of fungi grown under such nutrient-rich conditions. The fungi solubilised the insoluble silicon compounds under both oligotrophic and copiotrophic conditions. Silicon was not however, accumulated by fungi as electron-dense hyphal bodies. Addition of silicic acid to nutrient rich media also increased the growth of species of Streptomyces but decreased the chlorophyll content of the alga, Dunaliella parva; the growth of two yeasts and the bacteria, E. colt and S. aureus also was not affected by silicon addition; the observed stimulatory effect therefore appears to be restricted to filamentous microorganisms. The effect of silicon compounds on various microbial processes was also investigated. Silicic acid stimulated the production of citric acid by Aspergillus niger, but decreased nitrification and sulphur oxidation in this fungus. Silicic acid addition also led to a reduction in antibiotic production by species of Streptomyces. Studies were initiated to study the possibility that fungi and bacteria can erode the surface of both bulk and porous silicon wafers. While no such surface erosion was evident, we observed that E. coif underwent extensive extreme pleomorphism when growing under starvation conditions for up to 14 days. Such pleomorphism consisted of the formation of bulbous protrusions from the normal rod, dumbbell-shaped cells and long filaments, these were up to 50g in length (compared to the normal 1-3μ, rods). Such filamentation was clearly caused by the inability of the bacterial cells (rods) to separate on division. The observed bacterial pleomorphism was not however, silicon-specific, as it was also found to occur on titanium and glass surfaces. Such extreme pleomorphism may have important implications in relation to the growth of E. coli in low nutrient environments and may influence the bacterium's ability to affect pathogenesis. While the microbiology of silicon has largely been neglected the results of this thesis show that there is considerable interaction between this element and microbial growth. Future studies should in particular be directed towards determining if silicon can be used as an energy source by microorganisms. Additionally, the observed phenomenon of extreme pleomorphism in E. coil is clearly worthy of further study.
13
Frau, Alessandra. "Molecular microbiology of hydrocarbon polluted groundwater". Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.676470.
Testo completoAbstract (sommario):
The thesis is focused on the study of the microbiology of groundwater contaminated by diesel with three main goals. Firstly, to characterize the natural attenuation process, secondly, to increase knowledge of the role of microorganisms in the remediation of polluted environments and thirdly, to evaluate the efficacy of molecular biology methods to assess the in situ biodegradation potential of the microorganisms in such contaminated areas. This study includes the metagenomic characterization of the microbial community through the exploitation of next-generation sequencing techniques and the quantification of key biodegrative genes as biomarkers. Moreover, several strategies were put in place to understand the role of an uncultivated bacterial phylum (the OD1 candidate division) in the biodegradation of organic pollutants. These included the design of primer sets for the amplification of a functional gene specific for OD1 and the phylogenetic analysis of 16S rRNA sequences assigned to OD1 from several studies and a public database. A main outcome has been the characterization of the natural attenuation process in the site. A network of fermentative syntrophic bacteria and methanogenic archaea are the likely the protagonists of this process. The role of OD1 in the fermentation process was proposed. A thorough analysis of OD1 distribution has been carried out and phylogenetic cluster of ODl clades involved in this complex trophic network of fermentative bacteria and methanogens was identified.
14
Ngo, Chinh Chung. "Microbiology and Immunology of Otitis Media". Thesis, Griffith University, 2016. http://hdl.handle.net/10072/365263.
Testo completoAbstract (sommario):
Background
Over 80% of children experience acute otitis media (AOM) at least once during childhood, with 10-30% of children experiencing recurrent episodes of AOM (RAOM) or persistence of fluid in the middle ear (ME) lasting greater than 3 months which is defined as chronic otitis media with effusion (COME). Microbial infection remains the main cause of AOM, however the causes of RAOM and COME are not fully understood. Heavy loads of microbial colonisation and bacterial/viral interaction in the upper respiratory tract (URT) contribute to OM pathogenesis. It is currently unclear whether compromised host immune system responses have a significant role in RAOM/COME. Bacterial biofilms within the ME may contribute to otopathogen persistence and recurrent infection and/or inflammation in these children.
Aims
This study identified the predominant bacterial and viral otopathogens within the URT and ME, of children undergoing ventilation tube insertion (VTI) for RAOM/COME. Bacterial persistence within the ME, in the form of biofilms was also examined. Bacteria and viruses which were identified within the URT of children with RAOM/COME were compared to a control group of children who were undergoing adenoidectomy for treatment of adenoidal hypertrophy (AH) and/or obstructive sleep apnoea (OSA).
Local (saliva, middle ear effusion (MEE)) and systemic (serum) innate and adaptive immune responses were examined in children with and without RAOM/COME. Specific antibody levels to bacterial proteins as well as cytokine levels were determined. Systemic immuno-gene expression was compared between children with RAOM/COME and AH/OSA.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Medical Science
Griffith Health
Full Text
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TRINCHERA, MARIACRISTINA. "INNOVATION OF DIAGNOSTIC SYSTEM IN MICROBIOLOGY". Doctoral thesis, Università di Siena, 2016. http://hdl.handle.net/11365/1010583.
Testo completoAbstract (sommario):
The objective of this project is to create a highly automated system for screening urinary tract infections. Urinary infections are the major cause of diagnostic intervention (in and outpatient). The urino culture is the most required examination in the field of microbiology. The intention is to perform a series of analyses on a urine sample in order to highlight early pathological situations in other body districts.
There is urgency in the field of microbiology to become equipped with instruments that can act in automation at the call of diagnostic demand. There is also a request that the innovation have characteristics of sustainability according to the quality regulations dictated by the ISO 9000 quality management system. Furthermore, there is a need for the standardization of data. Currently, the medical microbiology field is not aligned with the rest of the world of analysis laboratories. Nowadays, in the normal laboratory, high automation diagnostic technology is present, particularly in the area of clinical chemistry. Microbiology is delayed for two main reasons: 1) elaborate analysis methods; 2) semi-quantitative interpretation of the results.
The DIESSE Diagnostica Senese spa, understanding the necessity, has built an analysis system specifically for the screening of urinary infections. In this work, we present the experimentation process PLUS FINDER++, the results from which offer decisive improvement in response quality, and timing. It is capable of influencing the diagnostic process positively because the PLUS FINDER++ reports the results of the sample analysis in 2 hours and 46 minutes, compared to the standard 48 to 72 hours. It must also not be underestimated that, thanks to these qualities, healthcare costs undergo a substantial reduction.
The experimentation was carried out in a number of healthcare structures, through a constant connection, in the analysis of the level of criticality, between the DIESSE operators present in the external structure alongside the in-house healthcare workers, in continual discussion with the professional operators of the primary company with its headquarters in Siena. It was this continuity and the analysis of the level of criticality in software defects, homepage graphics of the instrument or mechanical problems that have made an essential contribution to optimising the success of the PLUS FINDER++ System.
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Badia, Palacín Josefa. "Clonación y caracterización del operon de la ramnosa de Escherichia coli". Doctoral thesis, Universitat de Barcelona, 1987. http://hdl.handle.net/10803/672820.
Testo completoAbstract (sommario):
La L-fucosa y la L-ramnosa son dos azúcares naturales que E.coli es capaz de utilizar como fuente de carbono y energía. La diferencia estructrural entre la ramnosa (6- deoxi - manosa) y la fucosa (6-deoxi-galactosa) está unicamente en la posición del radical hidroxilo del c2 y c4.
La L-fucosa se metaboliza a través de la acción secuencial de una serie de enzimas inducibles: la fucosa permeasa, la fucosa isomerasa, la fuculosa quinasa y la fuculosa-1-fosfato aldolasa. Por su parte, la ramnosa se metaboliza por una vía análoga a la descrita para la glucosa por acción secuencial de una serie de enzimas inducibles: la ramnosa permeasa, ramnosa isomerasa y la ramnulosa quinasa) y la ramnulosa-1-fosfato aldolasa. Las vías convergen en un punto, de modo que lo descrito para fucosa es válido para glucosa.
Se ha de destacar que, si bien existe una gran analogía entre las reacciones implicadas en el catabolismo de la fucosa y de la ramnosa, los enzimas que participan son altamente específicos para cada vía, así como su inducción. También la localización cromosómica de los genes en ambos sistemas es totalmente diferente. Por tanto, a pesar de la gran similitud estructural entre la fucosa y la ramnosa, así como entre sus vías de degradación, los sistemas “fue” y “rha” se comportan de forma diferente por lo que respecta a los cuatro primeros enzimas de la vía metabólica, de manera que ambos dos sistemas parecen tener una organización genética diferente.
17
Nagano, Yuriko. "Application of molecular techniques in medical microbiology". Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479415.
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Jones, Frances Patricia. "The microbiology of lean and obese soil". Thesis, University of Reading, 2017. http://centaur.reading.ac.uk/69408/.
Testo completoAbstract (sommario):
The bacterial genus Bradyrhizobium is biologically important within soils, with different representatives found to perform a range of functions including nitrogen fixation through symbioses, photosynthesis and denitrification. The Highfield experiment at Rothamsted provides an opportunity to study the impact of plants on microbial communities as it has three long-term contrasting regimes; permanent grassland, arable and bare fallow (devoid of plants). The bare fallow plots have a significant reduction in soil carbon and microbial biomass. Bradyrhizobium has been shown by metagenomic studies on soil to be one of the most abundant and active groups including in bare fallow soil indicating that some phenotypes are adapted to survive in the absence of plants. A culture collection was created with isolates obtained from contrasting soil types from Highfield in addition to woodland soil, gorse (Ulex europeaus) and broom (Cytisus scoparius) root nodules. The collection’s phylogeny has been explored by sequencing housekeeping genes to determine whether soil treatment affects the core genome. One grassland and one bare fallow isolate had their genome sequenced and differences have been assessed to establish their potential for a range of functions and to direct future experiments. The functional diversity of the collection has been investigated using carbon metabolism assays to identify key substrates and determine whether the isolates group according to soil treatment. Symbiosis capacity and role in nitrogen cycling has been examined using nodulation tests, anaerobic growth on nitrate and nitrous oxide production and reduction through denitrification. A high level of diversity can be seen throughout the collection with differences being linked to niche adaptation. Understanding more about Bradyrhizobium could give clues on how above ground management impacts a key group within the soil community. Furthermore, the first assembled genomes of two non-symbiotic Bradyrhizobium strains isolated from soil provide an important resource for microbiology and soil ecology.
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Silva, João Carlos Tenente da. "Huambo Microbiology Laboratory : economical and financial viability". Master's thesis, Instituto Superior de Economia e Gestão, 2016. http://hdl.handle.net/10400.5/11857.
Testo completoAbstract (sommario):
Mestrado em FinançasEste trabalho foi realizado no âmbito de um projeto para uma empresa sediada em Huambo, na qual foi pedido uma análise de viabilidade económica e financeira para a construção de um laboratório de microbiologia de alimentos. Esta será a primeira empresa localizada em Huambo, na qual irá testar a qualidade dos produtos importados e exportados em Angola. Numa primeira fase foi estudado o valor inicial para este investimento, a nível de infraestruturas e equipamentos. Para conseguir uma previsão deste investimento, foram analisados alguns laboratórios concorrentes em Portugal, apesar da difícil comparação em termos de dimensão e custos. Este será um investimento realizado exclusivamente através de financiamento bancário. A taxa de juro para este empréstimo foi calculada com base nas taxas de juro aplicadas em casos e valores de financiamento semelhantes. De seguida, foi elaborado uma projeção do volume de negócios baseado na informação recolhida relativamente às importações e exportações neste sector. Com esse volume de negócio, foram calculados todos os custos inerentes ao funcionamento da empresa, como por exemplo, custos fixos e variáveis e custos com salários. Os custos do investimento irão ser depreciados ao longo dos cinco anos previstos. Para melhorar a análise, foram realizados três cenários, de forma, a perceber o quanto poderá influenciar algumas alterações nas previsões. Para perceber a viabilidade económica e financeira deste projeto foi utilizado o método do desconto dos Cash-Flow. Com este método foi também possível obter a taxa interna de rentabilidade e o período no qual o investimento será pago.
This work was carried out for a project in a company based in Huambo, which was asked for an economic and financial viability study for the construction of a food microbiology laboratory. This will be the first company located in Huambo, which will test the quality of imported and exported products in Angola. In a first phase the initial value was studied for this investment, such as buildings, frame-work and equipment. To get the investment’s provision, some competitors’ laboratories were analyzed in Portugal, despite the difficult comparison in terms of size and cost. This will be an investment made exclusively through bank financing. The interest rate for this loan was calculated based on the interest rates applied in similar cases and financing values. Then a turnover projection based on information collected on imports and exports in this sector was prepared. With this turnover, they calculated all the costs of operation of the business, such as fixed and variable costs and wage costs. The investment costs will be depreciated over the five year period. To improve the analysis, there were three scenarios (pessimistic, average and optimistic), in order, to realize how much changes on quantity and costs can influence the forecasts. To realize the economic and financial viability of this project we used the discount method of Cash Flow. With this method it was also possible to obtain the internal rate of return and payback period.
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Pitt, Sarah Jane. "Managing for quality in clinical microbiology services". Thesis, Liverpool John Moores University, 2001. http://researchonline.ljmu.ac.uk/5526/.
Testo completoAbstract (sommario):
The technical quality of the work performed in clinical microbiology laboratories is regularly monitored, by external and internal schemes. Among the factors which might affect quality, attitudes of the laboratory staff are rarely considered. In this study, three concepts recognised by occupational psychologists as being important in the work place, Job Satisfaction, Commitment and Climate, were measured among microbiology biomedical scientists (BMSs) in the United Kingdom A self-report questionnaire was developed through preliminary interviews and two pilot studies. The perceptions of Job Satisfaction, Commitment (to both Profession and Organisation) and Climate were measured using established models from the occupational psychology literature. Three scales were devised specifically during this study to assess an individual BMS's perceptions of the standard of their own performance, the attitudes of their colleagues towards their work and the quality within their laboratory. A fourth measure was developed which collated all the ways that technical quality in clinical microbiology laboratories is currently measured in the UK into one scale. A total of 2415 questionnaires were posted to BMSs employed in National Health Service, Public Health Laboratory Service, Privately funded and University laboratories between November 1998 and February 1999. By March 1999,931 replies had been received, a response rate of 39%. BMSs reported lower Job Satisfaction than Medical Laboratory Technologists (the equivalent profession) in the United States. The results supported Meyer and Allen's (1991) three-component model of commitment and showed that BMSs experienced Professional Commitment more strongly than Organisational Commitment. An eight dimension model of Climate was developed, for clinical microbiology staff, from Newman's (1977) Perceived Work Environment scale. BMSs' perceptions of Individual Climate were affected by a number of demographic factors, but the most important was the size of the laboratory. The optimal number of people in a clinical microbiology department for positive Individual Climate was found to be less than 30. Affective Commitment to the Profession was the component of Commitment which most strongly influenced technical quality, through its positive relationship with an individual BMS's performance at work. Through aggregation of Climate scores for selected laboratories, it was shown that Laboratory Climate correlated positively with technical quality. From BMSs' perceptions of their laboratory's quality, a scale to assess `A Climate for Laboratory Quality' was developed. There was a strong positive relationship between `A Climate for Laboratory Quality' and a department's score on the measure of technical quality. Interviews with staff in four clinical microbiology laboratories supported the questionnaire findings with respect to Laboratory Climate. Qualitative data collected from a representative group of users of each of the four microbiology services showed that users' main concern was rapid turnaround time for results. Comments also highlighted the need for more effective communication between laboratory staff their colleagues working directly with patients.
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Yuan, Heyang. "Bioelectrochemical Systems: Microbiology, Catalysts, Processes and Applications". Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/79910.
Testo completoAbstract (sommario):
The treatment of water and wastewater is energy intensive, and there is an urgent need to develop new approaches to address the water-energy challenges. Bioelectrochemical systems (BES) are energy-efficient technologies that can treat wastewater and simultaneously achieve multiple functions such as energy generation, hydrogen production and/or desalination. The objectives of this dissertation are to understand the fundamental microbiology of BES, develop cost-effective cathode catalysts, optimize the process engineering and identify the application niches. It has been shown in Chapter 2 that electrochemically active bacteria can take advantage of shuttle-mediated EET and create optimal anode salinities for their dominance. A novel statistical model has been developed based on the taxonomic data to understand and predict functional dynamics and current production. In Chapter 3, 4 and 5, three cathode catalyst (i.e., N- and S- co-doped porous carbon nanosheets, N-doped bamboo-like CNTs and MoS2 coated on CNTs) have been synthesized and showed effective catalysis of oxygen reduction reaction or hydrogen evolution reaction in BES. Chapter 6, 7 and 8 have demonstrated how BES can be combined with forward osmosis to enhance desalination or achieve self-powered hydrogen production. Mathematical models have been developed to predict the performance of the integrated systems. In Chapter 9, BES have been used as a research platform to understand the fate and removal of antibiotic resistant genes under anaerobic conditions. The studies in this dissertation have collectively demonstrated that BES may hold great promise for energy-efficient water and wastewater treatment.Ph. D.
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Липовська, Вікторія Вікторівна, Виктория Викторовна Липовская, Viktoriia Viktorivna Lypovska, Неля Георгіївна Горобченко, Неля Георгиевна Горобченко, Nelia Heorhiivna Horobchenko e D. M. Horobchenko. "Robert Koch - the father of clinical microbiology". Thesis, Видавництво СумДУ, 2012. http://essuir.sumdu.edu.ua/handle/123456789/27500.
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Dharod, Meghna. "Diabetic foot : microbiology, pathogenesis and glycan studies". Thesis, University of Westminster, 2010. https://westminsterresearch.westminster.ac.uk/item/9057z/diabetic-foot-microbiology-pathogenesis-and-glycan-studies.
Testo completoAbstract (sommario):
Complications of type 2 diabetes mellitus are one of the major causes of morbidity and mortality around the world. Diabetic foot infections remain one of the major complications leading to a leg loss every 3 seconds due to amputations causing mental trauma and distress. In diabetic foot ulcers aerobes, anaerobes and fungus often interact with each other and form biofilms which is difficult to treat, enhancing antimicrobial resistance and lead to a non-healing ulcer. Co-existing peripheral vascular disease and neuropathy exacerbate the problems. In T2DM patients’ minor cuts and wounds, often lead to hard to treat and chronic ulcers which can worsen to gangrene formation which may lead to osteomyelitis compromising the mechanics of the foot. It is necessary to identify the virulence factors of these clinically significant microbes and to identify the resistance patterns regularly to limit the antibiotic usage and target to the specific organisms. A Cohort studies were carried out in India and in the UK to identify the risk factors among the diabetic foot patients along with their microbial aetiology and antibiotic resistance patterns from the tissue and pus samples. This part of the research has shown the presence of mixed cultures mainly from the Indian diabetic foot ulcer specimens with higher percentages of anaerobes than aerobes. Multi-drug resistant organisms were one of the peculiar characteristics of the diabetic foot ulcer profiles of Indian patients. As compared to the Indian patients, UK patients had few resistant organisms and the patients admitted to hospitals in India were at the last stage of foot ulcers whereas in the UK, surveillance and preventative strategies allow early detection and intervention. Currently there is a lack of rapid, robust and an inexpensive diagnostic method for the rapid typing and identification of clinically significant anaerobes. Another part of the research focussed on utilising the glycan-lectin interactions by developing a simple enzyme linked lectin sorbent assay by employing biotinylated lectins to develop to an enzyme linked lectin sorbent assay (ELLA) on whole cells, Proteinase K treated cells and glycolipids of clinically significant aerobes and anaerobes. This study is concluded by utilising the glycan-lectin interactions and to develop a rapid typing method for clinically significant Methicillin resistant and sensitive Staphylococcus aureus and epidermidis species. The rapid identification of anaerobes and typing of Peptostreptococcus species was also by facilitated by the developed ELLA method. Finegoldia magna is one of the most significant anaerobes from soft tissue infections and the Gas Chromatography – mass spectrometry (GC-MS) of the glycolipids of Finegoldia magna on composition analysis using show the presence of sialic acid which could be involved in pathogenesis. This sugar may be one of virulence factor employed by this organism in either attachment to the host or to other organisms.
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Guermonprez, Cyprien. "Droplet-based Microfluidic Platform for Quantitative Microbiology". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX106/document.
Testo completoAbstract (sommario):
Développement d'une plateforme microfluidique pour la microbiologie quantitative. La plateforme permet la culture de milliers de colonies en parallèle dans des micro-gouttes. L'utilisation de tableau statique pour stocker les gouttes permet non seulement leur observation dans le temps pour des analyses dynamiques mais également la récupération de n'importe quelle goutte pour des études complémentaires. Nous avons également développé un outil permettant de soumettre les gouttes à des gradients chimiques directement sur la plateforme dont nous présentons les mécanismes physiques. Nous avons développé un software d'analyse des données générées par la plateforme pour l'étude de modèles de croissance bactérienne ainsi que l'impact des antibiotiques sur leur proliférationDevelopment of a microfluidic chip for quantitative microbiology. The chip allow for parallel culture of thousands bacterial colonies in micro-droplets stored in static array. The 2D-array enable not only the visualisation of each colonies in timelapse experiment but also the extraction of any of them out of the chip at any time for further analysis (PCR, re-culture,...). The platform is adaptable to a concentration gradient producer, for which we present the physical understanding of working mechanism, that can apply different chemical environments to each colony. We developed in parallel a software that perform the analysis of the data generated by the platform to adress bacteria growth studies as well as the impact of antibiotics on bacteria proliferation
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TESTI, DAVIDE. "Periodontal microbiology: new findings about oral microbiota". Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2014. http://hdl.handle.net/2108/203046.
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Lima, Raquel Maria Torres. "Relevance of Latent EBV infection in drug response of burkitt lymphoma cells". Doctoral thesis, Faculdade de Farmácia da Universidade do Porto, 2009. http://hdl.handle.net/10216/53912.
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Freitas, Ana Raquel Pinho. "Ecology and evolution of antimicrobial resistance in Enterococcus: a multilayered molecular approach with emphasys in the plasmid diversity". Doctoral thesis, Faculdade de Farmácia da Universidade do Porto, 2010. http://hdl.handle.net/10216/63801.
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Lima, Raquel Maria Torres. "Relevance of Latent EBV infection in drug response of burkitt lymphoma cells". Tese, Faculdade de Farmácia da Universidade do Porto, 2009. http://hdl.handle.net/10216/53912.
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Freitas, Ana Raquel Pinho. "Ecology and evolution of antimicrobial resistance in Enterococcus: a multilayered molecular approach with emphasys in the plasmid diversity". Tese, Faculdade de Farmácia da Universidade do Porto, 2010. http://hdl.handle.net/10216/63801.
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30
Song, Hao En. "Some suggestions on developing the Chinese microbiology market". Thesis, University of Macau, 2000. http://umaclib3.umac.mo/record=b1636668.
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31
Hole, Stephen J. W. "Biology, microbiology and management of enhanced carbetamide biodegradation /". Title page, abstract and contents only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phh729.pdf.
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Schuurman, Timothy. "Developments and clinical applications in diagnostic molecular microbiology". [S.l.] : Rotterdam : [The Author] ; Erasmus University [Host], 2008. http://hdl.handle.net/1765/13137.
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33
Dumas, Eve-Marie. "Development of new imaging tools for environmental microbiology". Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95020.
Testo completoAbstract (sommario):
Environmental microbiology is a field that has been explored for years using tools which are limited in their ability to adapt to the environment studied. The goal of this thesis is to develop new tools for in situ imaging of microorganisms. The first of these tools is a class of photoluminescent probes for fluorescence microscopy. Many microscopic dyes have been used with light microscopes to label microorganisms, but the protocol of each of these techniques limits either the type of organism targeted or the type of environment that can be studied. Most of these probes also only work for a short time due to photobleaching or degrade if stored. An emerging class of fluorophores in the field of cellular and microbiology is the quantum dot (QD), a semiconductor nanoparticle which has recently been made biocompatible. The use of QDs as bacterial probe I studied here, and characterized by studying the particles' interaction with and cytotoxicity to several test organisms, both Gram positive and Gram negative. We find that QDs are toxic to most bacteria due, among other things, to their production of reactive oxygen species. However, this affect varies from one strain to another, suggesting the existence of resistance mechanisms. Although QDs are more toxic to Gram negative strains, electron transfer and depolarisation does not seem to be the source of the toxicity. QDs have a promising future in microbiology as both labeling and anti-microbial agents. In the second part of the thesis, a new microscopic technology was explored for field use: live in-line holographic microscopy. A custom, laser-based holographic microscope was used in a Mars analogue site in order to determine whether it was capable of surviving the harsh conditions and of providing valid data. We experimented in automating the system by combining it with an amphibious robot which was shown to be able to pull the holographic microscope while the latter was recording. Overall, these findingsLa microbiologie environnementale est une discipline qui a longtemps été explorée à l'aide d'outils qui sont limités par leur habileté à s'adapter à l'environnement. Le but de cette thèse est de développer de nouveaux outils pour l'imagerie de microorganismes in situ. Le premier de ces outils est une classe de sonde photolumineuse pour la microscopie fluorescente. Plusieurs teintures ont été utilisé avec des microscopes à lumière afin d'étiqueter des microorganismes, mais chacune de ces techniques est limitée par son protocole. Ces techniques peuvent soit seulement cibler certains types d'organismes, soit sont limitée au niveau de l'environnement étudié. De plus, La plupart de ces teintures sont blanchient par la lumière et ne peuvent être entreposée très longtemps. Les points quantiques (PQ), une nanoparticule semiconductrice qui est maintenant biocompatible, sont maintenant utilisés en microbiologie. J'ai explore ici, l'utilisation de PQs comme sonde bactérienne et les est caractérisée en étudiant leur interaction avec et la toxicité causée à plusieurs microorganismes. Nous avons démontré que la toxicité des PQs est causée, entre autre, par la libération d'espèces d'oxygène réactive. Cependant, l'effet observé varie selon la souche, suggérant l'existence d'un procédé de résistance aux PQs. Nous avons conclus que malgré le fait que les bactéries Gram négatives sont plus affectée par les particules que les Gram positives, le transfère d'électron et la dépolarisation ne sont pas en cause. Les PQs ont un futur prometteur en microbiologie entant que sonde et agent antimicrobien. Dans la seconde partie de cette thèse, l'utilisation d'une nouvelle technologie microscopique sur le terrain a été explorée. Un microscope holographique au laser modifié a été utilisé sur un site analogue à la planète Mars afin de s'assurer que l'instrument pouvait subir ces conditions extrêmes sans dommage et pouvait
34
Doherty, C. J. "Cystic fibrosis microbiology : molecular fingerprinting of microbial pathogens". Thesis, University of Edinburgh, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.649603.
Testo completoAbstract (sommario):
CF lung infections are caused by a surprisingly narrow spectrum of pathogens and include Staphylococcus aureus, non-capsulate Haemophilus influenzae, Pseudomonas aeruginosa and Burkholderia cepacia. Stenotrophomonas maltophila is recovered from respiratory secretions with increasing frequency; however, its pathogenic role remains unclear. The primary aims of this thesis include the development and use of genomic fingerprinting systems to assist epidemiological investigations of CF pathogens, including S. maltophilia. Genomic fingerprinting is based on digestion of total bacterial chromosomal DNA with rare cutting enzymes, chosen on the basis of the bacterium's GC content. Separation of the DNA fragments, is then achieved by pulsed-field gel electrophoresis (PFGE) in an appropriate apparatus such as the Bio-Rad contour clamped homogeneous electric field (CHEF) system. Although a variety of other genomic typing systems are available, the thesis focused on PFGE, potentially the most discriminating system at present. Another major theme of the thesis concerned the epidemiology of B. cepacia. This highly adaptable plant and human pathogen causes great anxiety in the CF community on account of its inherent resistance, transmissibility and association with cepacia syndrome, a rapidly fatal pneumonia affecting approximately 30% of colonised patients. PFGE is technically demanding, time consuming and relatively expensive, thus attempts were made to assess the reliability and potential of other systems, in particular, PCR-ribotyping as a simple and rapid screening system for clonal analyses. The project provided a limited opportunity for fingerprinting and other microbiological studies of the commensal and pathogenic respiratory flora in CF patients participating in the first human trials of CF gene therapy. Specimens were examined before, during and after local nasal administration of a DNA/liposome complex. Although only a Phase 1 study was achieved during the duration of the thesis, microbiological analyses provided interesting results, in particular an unexpected lack of clonal relationship between S. aurens colonising the upper and lower airways.
35
Petters, Hannah Itam. "Studies on the microbiology of barley malt production". Thesis, Heriot-Watt University, 1988. http://hdl.handle.net/10399/978.
Testo completoAbstract (sommario):
Populations of aerobic heterotrophic bacteria, niycelial fungi and yeasts occurring in the production of barley malt were examined by plating on agar media and by scanning electron microscopy. There was an increase in the total number of micro-organisms during germination of barley, although populations declined after kilning. Bacteria dominated numerically in all samples, with progressively lower populations of yeasts and filamentous fungi. There was no obvious pattern of spatial distribution of micro-organisms On/in the samples, although there appeared to be high populations of bacteria and fungal hyphae on the inner surface of kernels. The dominant groups of aerobic heterotrophic bacteria were presumptively identified as Alcaligenes sp., Arthrobacter globiformis, Clavibacter iranicuin, Erwinia herbicola, Lactobacillus spp. and Pseudomonas fluorescens. The principal filainentous fungi were Alternaria alternata, Aspergillus glaucus group, Cladosporium macrocarpum, Epicoccum purpurascens, Fusarium avenaceum, Geotrichum candidum and Penicillium spp. The yeasts isolated most frequently were Candida catenulata, Q. vini, Debaryomyces hansenii, Hansenula polyniorpha, Kloeckera apiculata, Rhodotorula nrncilaginosa, Sporobolomyces roseus and Trichosporon bei gelii. Representative bacteria, mycelial fungi and yeasts were examined for the ability to degrade 8-glucan, starch or arabinoxylan. Approximately 50% of the fungi, <50% of the bacteria and <25% of the yeasts degraded these substrates. A culture filtrate of nivale demonstrated marked ability to reduce -glucan viscometrically and colorimetrically. The organism also degraded raffinose and sucrose. In micro-malting experiments the addition of Fusarium nivale and Geotrichum candidum did not produce substantial changes in terms of the physical and chemical characteristics of the finished malts.
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Bintsis, Thomas. "Aspects of the microbiology of Feta cheese brine". Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366049.
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Mendoza, L. S. "The microbiology of cooked rice and fish fermentation". Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356490.
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Watts, Ngaire Una. "The microbiology of chlorophenol degradation in mushroom composts". Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338633.
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Arat, Seda. "A Systems Biology Approach to Microbiology and Cancer". Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/75149.
Testo completoAbstract (sommario):
Systems biology is an interdisciplinary field that focuses on elucidating complex biological processes (systems) by investigating the interactions among its components through an iterative cycle composed of data generation, data analysis and mathematical modeling. Our contributions to systems biology revolve around the following two axes:
- Data analysis: Two data analysis projects, which were initiated when I was a co-op at GlaxoSmithKline, are discussed in this thesis. First, next generation sequencing data generated
for a phase I clinical trial is analyzed to determine the altered microbial community in human
gut before and after antibiotic usage (Chapter 2). To our knowledge, there have not been
similar comparative studies in humans on the impacts on the gut microbiome of an antibiotic
when administered by different modes. Second, publicly available gene expression data is
analyzed to investigate human immune response to tuberculosis (TB) infection (Chapter 3).
The novel feature of this study is systematic drug repositioning for the prevention, control
and treatment of TB using the Connectivity map.
- Mathematical modeling: Polynomial dynamical systems, a state- and time- discrete logical
modeling framework, is used to model two biological processes. First, a denitrification pathway
in Pseudomonas aeruginosa is modeled to shed light on the reason of greenhouse gas
nitrous oxide accumulation (Chapter 4). It is the first mathematical model of denitrification
that can predict the effect of phosphate on the denitrification performance of this bacterium.
Second, an iron homeostasis pathway linked to iron utilization, oxidative stress response and
oncogenic pathways is constructed to investigate how normal breast cells become cancerous
(Chapter 5). To date, our intracellular model is the only expanded core iron model that can
capture a breast cancer phenotype by overexpression and knockout simulations.Ph. D.
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Dabdoub, Shareef Majed. "Applied Visual Analytics in Molecular, Cellular, and Microbiology". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322602183.
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Khayat, Fahad Ali Abdulghany. "Detection of Abnormal Milk with Impedance Microbiology Instrumentation". DigitalCommons@USU, 1986. https://digitalcommons.usu.edu/etd/5332.
Testo completoAbstract (sommario):
Mastitic milk was detected by obtaining conductance measurements using an impedance microbiology Bactometer® 120 SC instruments. Conductance readings taken after 30 min at 25'C separated normal and abnormal milks when readings differed by more than 3% from the variance among instrument module wells. Samples blended from four quarters of a cow indicated milk from one quarter was abnormal if the salt level in the abnormal quarter raised the blend conductivity above that of normal samples and variance among the wells. Either solid or liquid substrates that contained bacterial stimulants could be used to accelerate bacterial acid production or to reduce impedance detection times, each without adversely affecting the ability to detect abnormal milk. However, measurements with liquid substrates varied with the volume of sample in the well. Results suggested that a fixed volume of one ml be used. Such a volume would allow simultaneous detection of abnormal milk and bacterial load on the same sample.
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Vera, Garcia Rodrigo Elizardo. "Microbiología del caracol Helix aspersa Müller. Aplicaciones biotecnológicas para su mejoramiento sanitario con impacto en su comercialización". Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399849.
Testo completoAbstract (sommario):
La Helicicultura se define como la cría a ciclo biológico completo de caracoles. El caracol terrestre Helix aspersa Müller es el más utilizados en distintas regiones europeas como alimento, que destaca por su alta prolificidad y capacidad de adaptación al ambiente. La cría de caracoles es una actividad ganadera, y no está exenta de la manifestación de procesos patológicos de origen microbiológico que ocasionan pérdidas productivas. Actualmente, la Helicicultura tiene por objetivo la comercialización de un caracol de calidad, sometido a rigurosos controles sanitarios y zootécnicos para garantizar su inocuidad y seguridad como alimento.
Los objetivos de esta Tesis doctoral son lograr optimizar y/o generar metodologías que faciliten la correcta administración de la cepa probiótica Lactobacillus plantarum Ca7, aislada desde caracoles, y que contribuyan a mejorar el estado sanitario de granjas destinadas a cría y engorde del caracol terrestre Helix aspersa Müller.
Los resultados obtenidos indican que, la contaminación presente en una nave destinada a la reproducción de caracoles, está relacionada con los microorganismos existentes en la microbiota intestinal de los animales, principalmente los de la familia Enterobacteriaceae, y que la microbiota se modifica si consume pienso contaminado. Los estudios sobre L. plantarum Ca7 indicaron que modificaciones en el medio de cultivo MRS, parámetros de incubación, y aquellos involucrados en el proceso de liofilización, permiten mejorar la producción de la biomasa, incrementar la concentración de la cepa liofilizada, y establecer las óptimas condiciones de almacenamiento de los cultivos liofilizados. Para el uso de un sistema en agitación que incorpora un cultivo de L. plantarum Ca7 para administrar a los caracoles a través del agua de riego, es preferible partir de cultivos no liofilizados y mezclarlos con agua de pozo para asegurar la sobrevivencia de la cepa y la inocuidad del preparado durante la hidratación de los caracoles. En relación al uso del sobrenadante de la cepa, se observó que posee propiedades inhibitorias sobre el desarrollo de microorganismos patógenos y sobre la formación de biopelículas de Staphylococcus aureus, además si esta fracción es liofilizada, aumentan sus propiedades inhibitorias, destacando el efecto sobre Pseudomonas aeruginosa. Este sobrenadante es posible incorporarlo al pienso de forma liofilizada sin que pierda sus propiedades inhibitorias. En laboratorio, tras la administración a caracoles de distinta edad de pienso enriquecido con L. plantarum Ca7, los resultados indicaron que este alimento modifica la microbiota, previene la mortalidad de los caracoles, y mejora la calidad microbiológica del pienso.
En base a estos resultados podemos indicar que la administración a caracoles de L. plantarum Ca7 y el uso de su sobrenadante para el control de microorganismos contaminantes presentes en la Helicicultura, serían capaces de ayudar a mejorar sanitariamente esta actividad ganadera, a través de la prevención de patologías de origen microbiano, modificación de la microbiota intestinal, y mejora de la calidad microbiológica del pienso. Efectos que conllevan a una mejora productiva durante la crianza del caracol, y entregan un valor agregado al producto final, con consecuente impacto en su comercialización.The Heliciculture is defined as the full life cycle breeding of snails. The land snail Helix aspersa Müller is the most used in different European regions as food, and it stand up for its high prolificacy and adaptability to the environment capacity. The breeding of snails is a livestock activity, and is not exempt from the manifestation of pathological processes of microbiological origin, that cause production losses. Currently, the Heliciculture aims at the marketing of quality snail, subjected to strict health and zootechnical controls to ensure the safety of this food. The objectives of this thesis are to optimize and/or create methodologies that facilitate the correct administration of the probiotic Lactobacillus plantarum Ca7 strain, which contributes to improve the health status of farms, intended for breeding and fattening land snail Helix aspersa Müller. The obtained results indicated that, the contamination present on a farm dedicated to snail reproduction, is associated with the microorganism in the intestinal microbiota of animals, mainly the Enterobacteriaceae Family, and the microbiota change because of contaminated feed consumption. The L. plantarum Ca7 studies, indicated that changes in the MRS culture medium, incubation parameters, and those involved in the lyophilization process, allow the improvement of the biomass production, increase of the lyophilized strain concentration, and the establishment of optimal storage conditions of freeze-dried cultures. For the use of an agitation system incorporating a culture of L. plantarum Ca7 to manage snails through irrigation water, it’s better to start whit no-lyophilized cultures, mixed with well water to ensure the survival of the strain and the safety of the preparation during the snails hydration. Concerning the use of the strain supernatant, observation showed that it possesses inhibitory properties on growth of pathogenic microorganisms and Staphylococcus aureus biofilm formation, also if this fraction is lyophilized, that increases its inhibitory properties, highlighting the effect on Pseudomonas aeruginosa. It is possible to incorporate this one to the feed in its lyophilized form without losing its inhibitory properties. In the laboratory, after the administration of the enriched with L. plantarum Ca7 feed to different age snails, the results indicated that this food alters the microbiota, prevents mortality of snails, and improves the microbiological quality of the feed. Based on these results, we can indicate that the administration of the L. plantarum Ca7 strain to snails, and its supernatant for contaminant microorganism control, present in the Heliciculture, would be able to help improve the sanitary livestock through the prevention of diseases of microbial origin, modification of the intestinal microbiota, and ameliorate the microbiological quality of the feed. Which leads to a productive improvement during snail breeding, and delivers added value to the final product, with consequent impact on marketing.
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Marí, Marí Teresa. "Changes in soil biodiversity and activity along management and climatic gradients". Doctoral thesis, Universitat de Lleida, 2017. http://hdl.handle.net/10803/457976.
Testo completoAbstract (sommario):
Els anomenats “rangelands” són àrees sense cultivar, àmpliament pasturades per animals domèstics i salvatges, actualment amenaçats pels canvis climàtic i en l’ús del sòl. Els microorganismes del sòl tenen un paper clau tant en la descomposició com en diversos processos de l’ecosistema, fet pel qual composició i funció de la comunitat microbiana han estat utilitzats durant molt temps com a índexs de fertilitat del sòl.
Els rangelands europeus i africans comparteixen un origen antropogènic comú, però el clima i la gestió del sòl els afecten d’una manera diferent. És per això que aquesta tesi pretén analitzar la comunitat microbiana d’ambdós tipus d’ecosistemes, per tal d’observar els efectes d’algunes de les amenaces comunes des d’una perspectiva més global.
Mentre que la sobrepastura va demostrar tenir l’efecte més perjudicial sobre la funció microbiana en sòls kenyans, es va trobar un efecte més fort del clima sobre els prats europeus. Els fongs i els bacteris van covariar al llarg de gradients altitudinals i climàtics, però la comunitat bacteriana va mostrar una recuperació més ràpida després de les pertorbacions biològiques i físico-químiques del sòl.
Aquest conjunt d’estudis afegeix nous coneixements sobre l’estructura i funció dels rangelands africans i europeus, i convida a explorar noves línies de recerca que incloguin tant bacteris com fongs alhora d’estudiar la comunitat microbiana del sòl.Los llamados "rangelands" son áreas sin cultivar, ampliamente pastoreadas por animales domésticos y salvajes, actualmente amenazados por los cambios climático y de uso del suelo. Los microorganismos del suelo tienen un papel clave tanto en la descomposición como en diversos procesos del ecosistema, por lo que composición y función de la comunidad microbiana han sido utilizados durante mucho tiempo como índices de fertilidad del suelo. Los rangelands europeos y africanos comparten un origen antropogénico común, pero el clima y la gestión del suelo les afectan de una manera diferente. Es por ello que esta tesis pretende analizar la comunidad microbiana de ambos tipos de ecosistemas, a fin de observar los efectos de algunas de las amenazas comunes desde una perspectiva más global. Mientras que el sobrepastoreo demostró tener el efecto más perjudicial sobre la función microbiana en suelos kenianos, se encontró un efecto más fuerte del clima sobre los prados europeos. Los hongos y las bacterias covariaron a lo largo de gradientes altitudinales y climáticos, pero la comunidad bacteriana mostró una recuperación más rápida después de las perturbaciones biológicas y físico-químicas del suelo. Este conjunto de estudios añade nuevos conocimientos sobre la estructura y función de los rangelands africanos y europeos, e invita a explorar nuevas líneas de investigación que incluyan tanto bacterias como hongos en el estudio de la comunidad microbiana del suelo.
Rangelands are uncultivated areas extensively grazed by wild and domestic animals, currently threatened by land use and climatic changes. Soil microorganisms play a key role in decomposition and several ecosystem processes and the composition and function of the microbial community have been long used as indices of soil fertility. African and European rangelands share a common anthropogenic origin, but climate and management affect them in a different way. That is why this thesis aimed to analyze the microbial community of both in order to observe the effects of some common threats from a more global perspective. While overgrazing proved to have the most detrimental effect on the soil microbial function in Kenyan soils, a stronger effect of climate was found to affect European grasslands. Fungi and bacteria co-varied along altitudinal and climatic gradients, but the bacterial community showed a fast recovery after biological and soil physico-chemical disturbances. This group of studies adds new knowledge on the structure and function of the African and European rangelands, and invite to explore new lines of research including both fungal and bacterial consortia when studying the soil microbial community.
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Schöne, Nadine [Verfasser]. "A new probabilistic approach in predictive microbiology / Nadine Schöne". Berlin : Freie Universität Berlin, 2011. http://d-nb.info/1025550803/34.
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Juwah, Charles Isitoa. "The microbiology and biochemistry of commercial pre-fermented doughs". Thesis, University of Strathclyde, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389697.
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Innocenti, Nicolas. "Data Analysis and Next Generation Sequencing : Applications in Microbiology". Doctoral thesis, KTH, Beräkningsbiologi, CB, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-173219.
Testo completoAbstract (sommario):
Next Generation Sequencing (NGS) is a new technology that has revolutionized the way we study living organisms. Where previously only a few genes could be studied at a time through targeted direct probing, NGS offers the possibility to perform measurements for a whole genome at once. The drawback is that the amount of data generated in the process is large and extracting useful information from it requires new methods to process and analyze it. The main contribution of this thesis is the development of a novel experimental method coined tagRNA-seq, combining 5’tagRACE, a previously developed technique, with RNA-sequencing technology. Briefly, tagRNA-seq makes it possible to identify the 5’ ends of RNAs in bacteria and directly probe for their type, primary or processed, by ligating short RNA sequences, the tags, to the beginnings of RNA molecules. We used the method to directly probe for transcription start and processing sites in two bacterial species, Escherichiacoli and Enterococcus faecalis. It was also used to study polyadenylation in E. coli, where the ability to identify processed RNA molecules proved to be useful to separate direct and indirect regulatory effects of this mechanism. We also demonstrate how data from tagRNA-seq experiments can be used to increase confidence on the discovery of anti-sense transcripts in bacteria. Analyses of RNA-seq data obtained in the context of these experiments revealed subtle artifacts in the coverage signal towards gene ends, that we were able to explain and quantify based Kolmogorov’s broken stick model. We also discovered evidences for circularization of a few RNA transcripts, both in our own data sets and publicly available data. Designing the tags used in tagRNA-seq led us to the problem of words absent from a text. We focus on a particular subset of these, the minimal absent words (MAWs), and develop a theory providing a complete description of their size distribution in random text. We also show that MAWs in genomes from viruses and living organisms almost always exhibit a behavior different from random texts in the tail of the distribution, and that MAWs from this tail are closely related to sequences present in the genome that preferentially appear in regions with important regulatory functions. Finally, and independently from tagRNA-seq, we propose a new approach to the problem of bacterial community reconstruction in metagenomic, based on techniques from compressed sensing. We provide a novel algorithm competing with state-of-the-art techniques in the field.QC 20150930
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Shaheen, Babar. "Effect of photodynamic therapy on the microbiology of acne". Thesis, Cardiff University, 2014. http://orca.cf.ac.uk/69644/.
Testo completoAbstract (sommario):
Light-based therapies, including photodynamic therapy (PDT), for acne are gaining popularity in dermatology. Based largely upon in vitro data, their beneficial outcome in acne is thought to be related to their bactericidal effects on Propionibacterium acnes. This randomised controlled study sought to determine the efficacy and tolerability of 610-950 nm IPL (administered as IPL-Placebo) and IPL-assisted methyl aminolaevulinate PDT (IPL-MAL) vs. adapalene 0.1% gel in the treatment of acne and to identify their mode of action, looking specifically at the effect on surface density of P. acnes. Thirty seven patients (31% of target due to slow recruitment) with mild to moderate facial acne were randomly allocated to IPL-MAL treatment, IPL-Placebo or adapalene. Both IPL groups received four treatments to the whole face, 2 weeks apart, while the third group was given adapalene nightly for 12 weeks. Assessments performed at baseline and weeks 8, 11, and 16 included inflamed, noninflamed and total lesion counts, Leeds grading, follicular porphyrin fluorescence, the Family Dermatology Life Quality Index and Dermatology Life Quality Index scores, and patient’s perspective of clinical improvement by the visual analogue scale (VAS). Cutaneous microflora was collected from all patients at similar intervals. Of the 37 patients randomised, only 30 completed the trial (10 in each group) and were included in the final analyses. Adapalene was found to be significantly superior to IPL-MAL and IPL-Placebo in reducing the noninflamed (adapalene 37.6% vs. IPL-MAL 3.4% vs. IPL-Placebo −9.7%) and total lesion counts (adapalene 35.7% vs. IPL-MAL 4.3% vs. IPL-Placebo −8.4%) at week 16. This was accompanied by a significant decrease (52.9%) in the DLQI score in this group (p = 0.031). The maximum improvement in inflamed lesion counts from baseline was seen at week 11 in the IPL-MAL (20.7%) and IPL-Placebo (13.4%) groups but occurred at week 16 in the adapalene group (26.5%). Statistical significance, however, was not reached in any group. There was no significant difference within or between the groups in the VAS, Leeds, FDLQI and porphyrin fluorescence results pre- and post- treatment. A significant increase in the density of propionibacteria (p = 0.021) and xxi coagulase-negative staphylococci (p = 0.039) was seen in the IPL-Placebo and IPL- MAL groups at week 16 and week 8, respectively; however, there was no significant difference between the groups. All the treatments were well tolerated. Adapalene remains an effective first line treatment in mild to moderate facial acne. However, the present study has remained indecisive (due to being underpowered) in drawing any firm conclusions regarding the efficacy of IPL and IPL-MAL on inflamed acne lesions. Further research is therefore warranted before their use can be advocated for acne treatment. An alternative mode of action for IPL and IPL-assisted MAL-PDT other than photodynamic destruction of P. acnes is suggested from the results of this study.
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Payler, Samuel Joseph. "Microbiology and the limits to life in deep salts". Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/33076.
Testo completoAbstract (sommario):
Deep subsurface evaporites are common terrestrial deep subsurface environments found globally. These deposits are known to host communities of halophilic organisms, some of which have been suggested to be millions of years old. The discovery of evaporite minerals on Mars has led to these environments becoming of interest to astrobiology, particularly because the subsurface of Mars represents the best chance of finding more clement conditions conducive to life. Despite this interest, deep subsurface evaporites remain poorly understood and we have little insight into how different salts shape the Earth's biosphere, much of which is underground. This thesis addresses several knowledge gaps present in the literature by sampling a selection of brine seeps and rock salt samples taken from Boulby Potash Mine, UK. The origin and evolution of the brines is determined with geochemical techniques, showing the majority to have been sourced from an aquifer above where they were intersected in the mine. These brines appear to have taken a variety of pathways through the subsurface leading to the presence of a range of different ions dissolved within them. The majority are Na/Cl dominated, whilst one is K/Cl dominated. One brine appears to have a different origin and probably interacted with dolomite becoming very concentrated in Mg. This variety in brine origins and migration pathways has impacted the habitability of the brines. Physicochemical measurements for chaotropicity, water activity and ionic strength, combined with culturing experiments suggest brines from the Sherwood Sandstone were habitable, but the brine from a distinct unknown source was uninhabitable. DNA was successfully extracted from three of the habitable brines and their metagenomes sequenced. These revealed communities largely functionally and phylogenetically similar to surface near saturation brines, indicating that the structure of the communities present in saturated Na/Cl brines are controlled almost exclusively by these ions rather than any other environmental difference between the surface and subsurface. Organisms were also taken from these brines and culturing experiments carried out to determine if any carbon sources were present in ancient salt that might promote growth in the absence of other carbon sources. Controls showed that the geochemical changes to the growth media induced by solving the salts, particularly sylvinite, were responsible for the increases in growth observed, indicating certain salt minerals effectively fertilise the growth of halophiles. Culturing on hydrocarbon seeps collected in the mine suggested they may provide a carbon source periodically to some organisms within the deposit. Work was done to show the presence of dissimilatory sulphate and iron reducing halophiles. Overall this significantly advances our understanding of how salts shape the Earth's biosphere, particularly its deep subsurface component, and what functional capabilities life has to persist in these environments. This work provides a new window on the potential habitability of deep subsurface extraterrestrial environments and how we might go about investigating these environments for habitable conditions.
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Olaonipekun, Basirat Arinola. "Application of predictive food microbiology to reduce food waste". Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/65935.
Testo completoAbstract (sommario):
Universal food insecurity continue to be a challenge that needs attention from all stakeholders. The problem of food waste however is highly important as it slows down the effort to improve food security, most especially in the world’s poorest countries. Conservative shelf life estimation of RTE foods by food producers is one of the major contributor to food waste. After a survey was carried out on the different RTE food products (n=195) available on the shelf of 3 supermarkets in Hatfield, with their set shelf life and storage instructions. Microbiological quality (Total viable count, LAB, Enterobacteriaceae, yeasts and moulds, and Pseudomonas spp.) and safety (E. coli, Staphylococcus aureus, Listeria spp. and Salmonella spp.) was conducted on selected RTE products (used as a reference point) during storage at ± 5o C. This wass to evaluate the validity of the set shelf life of beef lasagne (3 days), egg noodles (3 days), pre-cut mango (4 days) and pre-cut papaya (4 days) by food producers. Challenge test study was also conducted on representative RTE food products (beef lasagne, egg noodles, and pre-cut mango) with relevant food borne pathogens (L. monocytogenes, Salmonella Typhimurium, and E. coli) during storage for 12 days at ± 5oC. Growth potential (?) of these pathogens in the RTE foods were calculated using the concept of EU-CRL technical guidance on shelf life for L. monocytogenes on RTE foods as ? values can be very useful in potential food safety risk evaluation. Performance of 4 different types of software (ComBase, PMP, MicroHibro & FSSP) was evaluated for use in shelf life estimation of these selected RTE foods. These software were selected based on different criteria (User-friendly, accessibility and availability and types of pathogens for its application). The predicted growth from these software were compared to observed growth (generated from experimental data got from challenge test) of L. monocytogenes in beef lasagne and egg noodles. Indices of performance; Coefficient of determination (R2), root mean square error (RMSE), bias factor (Bf) and accuracy factor (Af) were used to evaluate the performance of these software. All the RTE food products reviewed had no specific refrigeration storage temperature instruction on the product package. Storage test study indicated that some of these RTE foods (beef lasagne, pre-cut mango and papaya) could have longer shelf life (5, 13 and 5 days respectively), while egg noodles could be a potential public health risk due to the presence of food borne pathogens right from day of purchase. However, the challenge test results also confirmed the conservative shelf life estimation by food producers in that the shelf life of all the products evaluated can be extended (Beef lasagne by 6 days, Egg noodles by 6 days and pre-cut mango by 9 days) with no food safety risk associated with the extension. On the other hand. RTE egg noodles and beef lasagne may support the growth of L. monocytogenes (? > 0.5 log10 cfu/g) if present in the food while egg noodles may not support the growth of S. Typhimurium (? ? 0.5 log10 cfu/g). Beef lasagne and pre-cut mango may also not support the growth of E. coli (? ? 0.5 log10 cfu/g). Growth of L. monocytogenes predicted by ComBase, PMP, MicroHibro & FSSP in beef lasagne and egg noodles was in agreement with the observed growth from the challenge test study, with a fail-safe prediction. However, ComBase predictor had the closest prediction to the observed growth. Hence, it had overall best performance for prediction compared to the other software. Notwithstanding, all the software evaluated in this study can be applied in shelf life prediction of RTE food products. Predictive microbiology is a field of food microbiology that can be looked into and implemented by the authorities. Its use by the South African food industry to scientifically estimate the shelf life of RTE food products is thereby encouraged. This will assist in decision making with regards to food quality and safety, thereby reducing the problem of food waste as result of product shelf life and at the same time protect public health.Dissertation (MSc)--University of Pretoria, 2017.
Food Science
MSc
Unrestricted
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Walker, Candace Lynette. "Implementing Inquiry-Based Learning in a General Microbiology Laboratory". Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/43973.
Testo completoAbstract (sommario):
In recent years there has been an increased interest in inquiry-based learning, also known as experiential learning or problem-based learning, as a more appropriate model of teaching science. The purpose of this study was to incorporate inquiry-based learning in a college sophomore-level General Microbiology Laboratory. The goal of this laboratory course is to introduce students to basic techniques and procedures necessary for the study of microorganisms. Laboratory sections were randomly assigned to an experimental group or a control/reference group. The experimental group was taught the concept of serial dilutions using an inquiry-based learning approach whereas the control group was taught using traditional teaching methods. Analysis of the data generated from the students' involvement in the investigation during the fall semester indicated that the experimental group had a slightly greater improvement in their knowledge of serial dilution. The study continued in the spring semester and involved close to 300 students. During the spring semester both the experimental and the control groups had similar attitudes about their learning experience as evaluated by a Lickert Scale survey. However, a statistical analysis of the quiz scores of the students with values within the interquartiles indicated the experimental classes' quiz scores were significantly higher on quiz 2 taken at the midpoint in the study. Thus an inquiry-based learning approach was found to be beneficial to the middle 50% of the class.Master of Science