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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Molecular analysis of secretion genes located on the syr-syp genomic island of Pseudomonas syringae pv. syringae strain B301D

Kang, Hyojeung 17 February 2005 (has links)
An RND (resistance-nodulation-cell division) transporter, called the PseC protein, was identified at the left border of the syr-syp genomic island of Pseudomonas syringae pv. syringae strain B301D. The PseC protein exhibited amino acid homology to a putative RND transporter of Ralstonia solanacearum with identities of 61% (i.e., PseC). The pseC mutant strain showed a larger reduction in syringopeptin secretion (67%) than syringomycin secretion (41%). A β-glucuronidase assay with a pseA::uidA reporter construct indicated that the GacS/A two-component system controls expression of the pseA gene. Expression of the sypA gene by mutant strain B301D-HK4 corresponded to approximately 13% of that by parental strain B301D, whereas the syrB1 gene expression by mutant strain B301D-HK4 was nearly 61%. Mutant strain B301D-HK4 was reduced in virulence by about 58% as compared to parental strain B301D. A drug-supersensitive acrB mutant of E. coli showed increased resistance to acriflavine and tetracycline upon heterologous expression of the pseA, pseB, and pseC genes. Thus, the PseC protein, an RND transporter, has an important role in secretion of syringomycin and syringopeptin. An ATP-binding cassette (ABC) transporter, called the PseF protein, was identified at the left border of the syr-syp genomic island. The PseF protein exhibited amino acid homology to a putative ABC transporter of E. coli W3104 with identities of 57.6% (i.e., PseF to MacB). The pseF mutant strain showed significant reduction in secretion of syringomycin (74%) and syringopeptin (71%). Expression of the sypA gene by mutant strain B301D-HK7 was approximately 6.9% as compared to that of parental strain B301D, while the syrB1 gene expression by mutant strain B301D-HK7 was nearly 14.6%. Mutant strain B301D-HK7 was less virulent by approximately 67% than parental strain B301D. Expression of the pseF gene was induced approximately six times by strain B301D grown on SRMAF, as compared to that of strain B301D grown on SRM. During infection of bean plants by P. syringae pv. syringae strain B728a, expression of the pseF gene increased 3 days after inoculation. Thus, the PseF protein, an ABC transporter, responsible for secretion of syringomycin and syringopeptin is required for full virulence.
202

Activity Based Costing : Is it applicable in an event organising firm?

Saitovic, Maja, Saliji, Valdete, Enow, Carine January 2007 (has links)
<p>Companies need different information about their operations, so that they can make better decisions and be more effective in the business world. One way to obtain that information is through looking at how costs are assigned to different cost objects, such as products or services. Of special interest is the allocation of indirect costs, because if these costs make up an important part of an organisation, then grasping them will help the firm be more competitive and respond better to customers and their needs.</p><p>One method of allocating indirect costs is called activity based costing, or ABC, and it looks upon what activities that are being performed by a company, how much they cost based on resource usage, what drives the costs, and most importantly, it assigns these ex-penses to products/services.</p><p>The aim of this thesis has been to investigate whether the ABC method can be applied in an event organising company. In order to reach the purpose we have used the example of Elmia AB, an event and trade show organiser situated in Jönköping, Sweden. The focus of our investigation was exhibition stands used in trade shows.</p><p>We have come to the conclusion that activity based costing is applicable when it comes to event organisers in the sense that it is possible to identify major activities and depict re-sources. However, problems emerge when trying to estimate costs of resources because it is hard to know in advance what customers want, and therefore one cannot clearly distin-guish or set fixed and variable costs, nor can one easily cope with problems of unused ca-pacity, that is resources that are supplied but not used. This is especially the case with cus-tomised exhibition stands. The process is somewhat easier when it comes to standardised offerings, because they are less complicated since they are already set and cannot be much altered by the customers. Furthermore, cost drivers can be applied in this setting, at least theoretically because they provide help in determining what processes the customers might find important. On the other hand, they might be rather difficult to measure. Finally, the actual assigning of costs to cost objects is hard, because for the complex solutions, one cannot easily find common activities across different stands, but this can be easier to do when exhibition stand pack-ages are standardised and demand is better traceable.</p><p>We have based our results on one company as a generalisation of event organisers as a whole, and we can argue that the example that we have chosen can be a good representa-tive of this particular branch of the service industry, because it shows how important indi-rect costs are to this dynamic business and also it reveals the importance of customers and their role when applying activity based costing to the environment. However, in order to have a complete conclusion with respect to our aim, more research is needed in other event and trade show organising firms because there are company specific situations in terms of size, structure, culture, etc, of a company that makes ABC a special case that changes ac-cording to different objectives of different users.</p>
203

PARENTS' PERCEPTIONS OF AND GOALS FOR ALPHABET BOOKS

Nowak, Sarah 23 August 2011 (has links)
This study examined parents’ goals for reading ABC books with their children and their perceptions of page features. Factor analysis of a questionnaire answered by 225 parents of junior and senior kindergarten students revealed four goals for reading alphabet books. In order of importance as rated by parents the goals were: Learning to Read, Enjoyment and Bonding, Learning from Books, and Soothe the Child. Maternal education, number of ABC books owned and ABC book reading frequency were related to parents’ goals. When viewing ABC pages, parents rated pages with little text, simple illustrations and letter sound-word consistency as more appropriate for fulfilling purposes related to learning to decode than pages with a lot of text, complex illustrations, and letter sound-word violations. Findings highlight that parents’ perceptions of which alphabet book page features are more appropriate for decoding purposes are congruent with previous research and experts’ advice. / SSHRC
204

Étude des états électroniques en champ magnétique dans le niveau de Landau N=O de la tricouche ABC de graphène

Rondeau, Maxime January 2013 (has links)
Dans cet ouvrage nous étudions les phases du gaz d'électrons bidimensionnel dans la tricouche de graphène en empilement ABC . En partant du modèle des liaisons fortes et en faisant l'approximation du continuum autour des vallées K + , K- , nous obtenons un modèle effectif à deux bandes qui permet de décrire la physique de basse énergie des électrons en champ magnétique dans cette structure. Ce modèle contient trois orbitales dégénérées dans le niveau de Landau N = O. Ce dernier est donc 12N [straight phi] , fois dégénérés en incluant les degrés de liberté de spin et de vallée. En ajoutant l'interaction de Coulomb au système et en considérant seulement les remplissages v = -5, -4, -4, 5 afin d'avoir un système à trois niveaux, nous étudions le diagramme de phase du gaz d'électrons en fonction d'un biais électrique entre les couches externes. Nous trouvons une phase d'onde de densité de charge bidimensionnelle ( ODC2D ) comme état fondamental du système. Cette ODC2D se nomme cristal dans ce mémoire et nous dérivons ses propriétés de transports et ses modes collectifs. Nous discutons également du caractère topologique de ce cristal. Notre étude englobe aussi les phases liquides avec ou sans cohérence orbitale. Nous concluons notre mémoire par l'étude de quelques signatures expérimentales des phases du gaz d'électrons dans la tricouche. [symboles non conformes]
205

Design Of A General Customer Segmentation Process

Vuckic, Asmir, Cosic, Renato January 2015 (has links)
Syfte - Att undersöka hur en kundsegmenteringsprocess kan utformas samt vilka variabler man bör iaktta för att kunna erbjuda en lämplig kundservicenivå. För att uppnå detta syfte skall följande frågeställningar besvaras: 1. Vilka variabler bör ingå i en kundsegmentering? 2. Hur kan en kundsegmenteringsprocess utformas? Metod - En generell kundsegmenteringsprocess utformades. Processen har utvecklats genom kvalitativ forskning baserad på litteraturstudier samt intervjuer i en fallstudie. Under litteraturstudien granskades teorier i ämnet för att besvara frågeställningarna. Detta jämfördes senare med empirin som samlats under fallstudien. Resultat - Den utformade processen innehåller sju dimensioner med tillhörande variabler. Under studien har variablerna utvärderats för att ta reda på hur de påverkar situationen. Endast de variabler som hade ett stort inflytande på situationen togs med i processen. Studien visade att det finns olika strategier för att utföra en kundsegmentering. Vid utformning av en kundsegmenteringsprocess är det viktigt att veta vilka variabler som passar organisationens bransch samt hur de påverkar resultatet. Omfång och Avgränsningar - Rapporten är begränsad till att utforma ett förslag på en kundsegmenteringsprocess. Processen kommer därför inte att tillämpas på fallföretaget under fallstudien. Processen kan fortfarande generaliseras och användas av företag med liknade egenskaper. Ytterligare forskning skulle kunna sträva efter att inkludera andra variabler som passar in på fler branscher. Implikationer - Den utformade processen hjälper till vid beslutssituationer avseende kundsegmentering. Genom att balansera de variabler som föreslagits möjliggör dem en grund för olika kundserviceerbjudanden. Dessa variabler beaktar den eftersträvade generaliseringen. Bidrag och Rekommendationer - Kundsegmenteringsprocessen som presenteras i denna rapport är, såvitt författarna vet, den första i sitt slag med sin layout. Variablerna kan även användas i andra segmenteringsprocesser vilket visar en hög grad av generalisering. Vad som är unikt med den designade processen i denna rapport är att den innehåller en mix av två väl beprövade teorier inom kundsegmentering nämligen, Kotler’s (2009) Bottom-Up-Approach och Weinstein’s (2004) B2B Market Segmentation. / Purpose – To examine how the process of customer segmentation can be designed, and which variables to consider to offer an appropriate customer service. To achieve this purpose the following questions will be answered: 1. Which variables should be included in customer segmentation? 2. How can a customer segmentation process be designed? Method – A general process was designed. The process has been developed through qualitative research based on literature review and interviews conducted in a case study. During the literature review the authors sought for theories on the subject in order to answer the research questions. This was later compared to the empirical evidence collected from the case study. Findings – The designed process contains seven dimensions with related variables. During the study the variables were evaluated concerning their impact on the situation. Only variables that had a high influence on the situation were implemented in the process. The study showed that that there are various approaches towards performing customer segmentation. When designing a customer segmentation process, it is of high importance to know which variables suit the organizations line of business and how they affect the outcome. Research limitations – The thesis is restricted into designing a customer segmentation process, the process will therefore not be applied on the case company during the case study. The process can still be generalized and usable for companies with similar distribution setup. Further research could strive to include other variables. Implications – The designed process assists in the decision-making situation regarding customer segmentation. By balancing the variables it enables a basis for customer service offering. These variables take the requested generalization in consideration. Originality/value – The customer segmentation process presented in this thesis is, as far as the authors know, the first in its kind with its layout. The variables could be used in other segmentation processes as well which show a high grade of generalization. What is unique with the designed process in this thesis is that it contains a mixture of two well proven customer segmentation theories namely, Kotler’s (2009) Bottom-Up-Approach and Weinstein’s (2004) B2B Market Segmentation.
206

Utformning av en modell för lagerstyrning hos Atlas Copco GIA baserat på artikelklassificering / Design of a model for inventory control at Atlas Copco GIA based on article classification

Andersson, Martin, Jonasson, Gustav January 2014 (has links)
Atlas Copco GIA tillverkar tunga maskiner och ventilationsutrustning till gruvindustrin. Branschen präglas av stor osäkerhet gällande efterfrågan och produktionen sker i relativt liten skala till följd av industrins begränsningar. För att behålla sin konkurrenskraft på marknaden erbjuder GIA möjlighet till stor kundspecifikhet i sitt produktutbud, och kunden får därmed stor valmöjlighet att modifiera de maskiner som beställs. Lågskalig produktion, varierad efterfrågan och hög kundspecifikhet gör det svårt för GIA att styra sitt lager och har därmed lett till hög kapitalbindning. Till följd av GIAs situation har examensarbetet genomförts och syftar till att föreslå en differentierad lagerstyrningsmodell för att möjliggöra en effektivare styrning av GIAs lager. Styrningsmodellen är därmed tänkt att minska kapitalbindningen samtidigt som lagertillgängligheten ej får påverkas negativt. Ett första steg vid konstruktion av föreslagen lagerstyrningsmodell har varit att genomföra en ABC-klassificering för det artikelsortiment som ingår i studien. Klassificeringen har möjliggjort en kategorisering av artiklarna baserat på dess ledtid och volymvärde. Ytterligare analys har genomförts för att mynna ut i fyra artikelgrupperingar som ligger till grund för lagerstyrningsmodellen. Modellen har konstruerats via analys av de lagerstyrningsprinciper som den teoretiska referensramen beskriver, men även baserat på genomförda intervjuer med inköpspersonalen på GIA för att få med många olika aspekter. Simuleringar har genomförts för att testa modellens agerande och dessa indikerar på att kapitalbindningen sjunker samt att fokus skiftar och läggs på volymvärda produkter, vilket är önskvärt. Även lagertillgängligheten antas bibehållas eller öka på grund av föreslagen lagerstyrningsmodell.
207

SiaA: A Heme Protein

Libkind, Marianna 19 February 2007 (has links)
The protein SiaA (Streptococcal iron acquisition) is involved in heme uptake in the bacterium Streptococcus pyogenes. It is difficult to obtain this protein in its fully holo form (completely loaded with heme). To increase the concentration of heme in the growing cell, we added ä-aminolevulinic acid (ALA) and ferrous sulfate (FeSO4), precursors of heme, to the growth media. Neither increasing the concentration of heme in vivo, nor growth at lower temperature for longer times, increased the production of holoprotein. The classical method of measuring the concentration of heme in a newly discovered heme protein is cumbersome. We have developed an improved method, which gives a solution that is more stable and has a cleaner spectrum. With further development, this new technique may replace the classical assay. Background information on S. pyogenes, SiaA, ABC transporters, heme biosynthesis, and the pyridine hemochrome assay are described.
208

Putative lipoproteins of Streptococcus agalactiae identified by bioinformatic genome analysis

Harrington, Dean J., Sutcliffe, I.C. January 2004 (has links)
Streptococcus agalactiae is a significant pathogen causing invasive disease in neonates and thus an understanding of the molecular basis of the pathogenicity of this organism is of importance. N-terminal lipidation is a major mechanism by which bacteria can tether proteins to membranes. Lipidation is directed by the presence of a cysteine-containing lsquolipoboxrsquo within specific signal peptides and this feature has greatly facilitated the bioinformatic identification of putative lipoproteins. We have designed previously a taxon-specific pattern (G+LPP) for the identification of Gram-positive bacterial lipoproteins, based on the signal peptides of experimentally verified lipoproteins (Sutcliffe I.C. and Harrington D.J. Microbiology 148: 2065¿2077). Patterns searches with this pattern and other bioinformatic methods have been used to identify putative lipoproteins in the recently published genomes of S. agalactiae strains 2603/V and NEM316. A core of 39 common putative lipoproteins was identified, along with 5 putative lipoproteins unique to strain 2603/V and 2 putative lipoproteins unique to strain NEM316. Thus putative lipoproteins represent ca. 2% of the S. agalactiae proteome. As in other Gram-positive bacteria, the largest functional category of S. agalactiae lipoproteins is that predicted to comprise of substrate binding proteins of ABC transport systems. Other roles include lipoproteins that appear to participate in adhesion (including the previously characterised Lmb protein), protein export and folding, enzymes and several species-specific proteins of unknown function. These data suggest lipoproteins may have significant roles that influence the virulence of this important pathogen.
209

Administración Científica del Inventario, reabastecimiento óptimo de pedidos de la Empresa “Aspersud – O y M

Pillaca Huaytalla, Edith January 2008 (has links)
La presente monografía tiene como objetivo minimizar los costos totales de pedidos, proponer un sistema de inventario que permita saber cuánto y cuando pedir, esto será relevante para la nueva política de inventarios. Para ello se han aplicado modelos de inventarios que se ajuste a las condiciones de la empresa Aspersud, la misma que tiene un departamento de Operaciones y Mantenimiento al cual llamamos también departamento de O y M, que se encarga de conservar los institutos IRU y ILN funcionales y seguros, optimizando la vida útil de cada uno de sus componentes. En la actualidad O y M presenta una nueva política de reducción de costos. Adicionalmente, la presente Monografía tiene la finalidad de demostrar la importancia de que toda organización lucrativa o no, debe aplicar un sistema de inventarios que le permita tener un buen control, y tener la certeza de tomar buenas decisiones. No solo se enuncia el modelo matemático de inventario, además de hacer un análisis de la procedencia de dicha fórmula que permite minimizar mis costos de pedido y saber en qué momento se debe reabastecer.
210

The cytotoxic effects of novel jadomycins in drug-sensitive and drug-resistant MCF7 breast cancer cells

Issa, Mark 15 August 2012 (has links)
Multidrug resistance refers to the simultaneous resistance to structurally and mechanistically unrelated cytotoxic drugs. Chronic administration of cytotoxic drugs to patients with metastatic breast cancer results in the development of multidrug resistance, thus rendering chemotherapy unsuccessful. One mechanism by which multidrug resistance is conferred is the decreased intracellular drug accumulation due to the upregulation of the ATP-binding cassette (ABC) transporters. Jadomycins are polyketide-derived natural products produced by the soil actinomycetes Streptomyces venezuelae, ISP 5230. Jadomycins exhibit anticancer, antibacterial and antifungal activities. Pilot work in our laboratory demonstrated that jadomycin B exhibited similar cytotoxic effects in drug-sensitive and drug-resistant cancer cells. We hypothesize that jadomycins are poor substrates of ABCB1, ABCC1 and ABCG2 efflux transporters, and consequently will exhibit higher intracellular accumulation, which results in improved cytotoxic efficacy over existing chemotherapeutics that are rapidly effluxed by ABC transporters. Using methyltetrazolium (MTT) cell viability assays, the cytotoxic efficacy of nine jadomycin analogues (DNV, L, B, SPhG, F, W, S, T and N) in drug-sensitive and drug-resistant MCF7 breast cancer cells was evaluated. Jadomycin B, L, S and T were found to be equally toxic to drug-sensitive and drug-resistant ABCB1, ABCC1 or ABCG2-overexpressing MCF7 breast cancer cells. The inhibition of ABCB1, ABCC1 or ABCG2 efflux transporters with verapamil, MK-571 or ko143, respectively, did not significantly augment the cytotoxic effects of jadomycin DNV, L, B and S in drug-resistant MCF7 cells, suggesting that these jadomycins are poor substrates of the targeted transporter. Furthermore, all nine jadomycin analogues did not increase the intracellular accumulation of ABCB1, ABCC1 or ABCG2 probe fluorescent substrates in HEK-293 cells, indicating that these jadomycins do not inhibit the efflux function of the transporters. We conclude that jadomycins B, L and S are effective agents in the eradication of resistant breast cancer cells grown in culture, and that the ability of specific jadomycins to retain cytotoxic efficacy in resistant cells stems from their limited interactions with ABCB1, ABCC1 or ABCG2 efflux transporters.

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