14 resultados para Components phenols of CNSL

em Helda - Digital Repository of University of Helsinki


Relevância:

100.00% 100.00%

Publicador:

Resumo:

In recent years, XML has been accepted as the format of messages for several applications. Prominent examples include SOAP for Web services, XMPP for instant messaging, and RSS and Atom for content syndication. This XML usage is understandable, as the format itself is a well-accepted standard for structured data, and it has excellent support for many popular programming languages, so inventing an application-specific format no longer seems worth the effort. Simultaneously with this XML's rise to prominence there has been an upsurge in the number and capabilities of various mobile devices. These devices are connected through various wireless technologies to larger networks, and a goal of current research is to integrate them seamlessly into these networks. These two developments seem to be at odds with each other. XML as a fully text-based format takes up more processing power and network bandwidth than binary formats would, whereas the battery-powered nature of mobile devices dictates that energy, both in processing and transmitting, be utilized efficiently. This thesis presents the work we have performed to reconcile these two worlds. We present a message transfer service that we have developed to address what we have identified as the three key issues: XML processing at the application level, a more efficient XML serialization format, and the protocol used to transfer messages. Our presentation includes both a high-level architectural view of the whole message transfer service, as well as detailed descriptions of the three new components. These components consist of an API, and an associated data model, for XML processing designed for messaging applications, a binary serialization format for the data model of the API, and a message transfer protocol providing two-way messaging capability with support for client mobility. We also present relevant performance measurements for the service and its components. As a result of this work, we do not consider XML to be inherently incompatible with mobile devices. As the fixed networking world moves toward XML for interoperable data representation, so should the wireless world also do to provide a better-integrated networking infrastructure. However, the problems that XML adoption has touch all of the higher layers of application programming, so instead of concentrating simply on the serialization format we conclude that improvements need to be made in an integrated fashion in all of these layers.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Purpose – This research paper studies how the strategy of repositioning enables marketers to communicate CSR as their brand’s differentiating factor. It aims at understanding how consumer perceptions can be managed to generate brand value through corporate brand repositioning when CSR is the differentiating factor. The purpose of this paper is to answer the following research question: How can consumer perceptions be managed to generate brand value through corporate brand repositioning when CSR is the differentiating factor? The two research objectives were: 1. to build a model, which describes the different components of consumer perceptions involved in generation of brand value through repositioning when CSR is the differentiating factor, 2. to identify the most critical components in the context of the case company, IKEA for generation of brand value during the process of corporate brand repositioning Design/methodology/approach – This paper is based on the literature review covering the logic of brand value generation, repositioning strategy and consumer perceptions connected to CSR activities. A key concept of the positioning theory, the brand’s differentiating factor, was explored. Previous studies have concluded that desirability of the differentiating factor largely determines the level of brand value-creation for the target customers. The criterion of desirability is based on three dimensions: relevance, distinctiveness and believability. A model was built in terms of these desirability dimensions. This paper takes a case study approach where the predefined theoretical framework is tested using IKEA as the case company. When developing insights on the multifaceted nature of brand perceptions, personal interviews and individual probing are vital. They enable the interviewees to reflect on their feelings and perceptions with their own words. This is why the data collection was based on means-end type of questioning. Qualitative interviews were conducted with 12 consumers. Findings – The paper highlights five critical components that may determine whether IKEA will fail in its repositioning efforts. The majority of the critical components involved believability perceptions. Hence, according to the findings, establishing credibility and trustworthiness for the brand in the context of CSR seems primary. The most critical components identified of the believability aspect were: providing proof of responsible codes of conduct via conducting specific and concrete CSR actions, connecting the company’s products and the social cause, and building a linkage between the initial and new positioning while also weakening the old positioning. Originality/value – Marketers’ obligation is to prepare the company for future demands. Companies all over the globe have recognized the durable trend of responsibility and sustainability. Consumer´s worry about the environmental and social impact of modern lifestyles is growing. This is why Corporate Social Responsibility (CSR) provides brands an important source of differentiation and strength in the future. The strategy of repositioning enables marketers to communicate CSR as their brand’s differentiating factor. This study aimed at understanding how consumer perceptions can be managed to generate brand value through corporate brand repositioning when CSR is the differentiating factor.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The aim of this thesis was to compare the degradation of human oral epithelial proteins by proteinases of different Candida yeast species. We focused on proteins associated with Candida invasion in the cell-to-cell junction, the basement membrane zone, the extracellular matrix, and local tissue inflammatory regulators. Another main objective was to evaluate the effect of the yeast/hyphal transition and pH on the degradative capability of Candida. The enzymatic activity of the Candida proteinases was verified by gelatin zymography. Laminins-332 (Lm-322) and -511(Lm-511) produced by human oral keratinocytes were gathered from the growth media, and E-cadherin (E-Cad) was isolated from the cell membrane of the keratinocytes by immunoprecipitation. The proteins were incubated with Candida cells and cell-free fractions, and degradation was detected by fluorography. Fibronectin degradation was visualised by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE). Matrix metalloproteinase-9 (MMP-9) activation and tissue inhibitor of metalloproteinase-1 (TIMP-1) fragmentation was detected by using the Western blot and enhanced chemoluminescence (ECL) techniques. Residual activity of TIMP-1 was evaluated by a casein degradation assay. A fluorimetric assay was used to detect and compare Candida proteinase activities with MMP-9. These studies showed that the ability of the different Candida yeast species to degrade human Lm-332, fibronectin, and E-Cad vary from strain to strain and that this degradation is pH-dependent. This indicates that local acidic pH in tissue may play a role in tissue destruction by activating Candida proteinases and aid invasion of Candida into deeper tissue. A potential correlation exists between the morphological form of the yeasts and the degradative ability; the C. albicans yeast form seems to be related to superficial infections, and hyphal forms can apparently invade deeper tissues between the epithelial cells by degradation of E-Cad. Basement membrane degradation is possible, especially in the junctional epithelium, which contains only Lm-332 as a structural component. Local tissue host inflammatory mediators, such as MMP-9, were activated, and TIMP-1 was degraded by certain Candida species, thus indicating the possibility of a weakened host tissue defence mechanism in vivo.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Obesity increases the risk for several conditions, including type 2 diabetes mellitus, cardiovascular disease, hypertension, osteoarthirits and certain types of cancer. Twin- and family studies have shown that there is a major genetic component in the determination of body mass. In recent years several technological and scientific advance have been made in obesity research. For instance, novel replicated loci have been revealed by a number of genome wide association studies. This thesis aimed to investigate the association of genetic factors and obesity-related quantitative traits. The first study investigated the role of the lactase gene in anthropometric traits. We genetically defined lactose persistence by genotyping 31 720 individuals of European descent. We found that lactase persistence was significantly correlated with weight and body mass index but not with height. In the second study we performed the largest whole genome linkage scan for body mass index to date. The sample consisted of 4401 twin families and 10 535 individuals from six European countries. We found supporting evidence for two loci (3q29 and 7q36). We observed that the heritability estimate increased substantially when additional family members were removed from the analyses, which suggests reduced environmental variance in the twin sample. In the third study we assessed metabonomic, transcriptomic and genomic variation in a Finnish population cohort of 518 individuals. We formed gene expression networks to portray pathways and showed that a set of highly correlated genes of an inflammatory pathway associated with 80 serum metabolites (of 134 quantified measures). Strong association was found, for example, with several lipoprotein subclasses. We inferred causality by using genetic variation as anchors. The expression of the network genes was found to be dependent on the circulatory metabolite concentrations.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The objective was to measure productivity growth and its components in Finnish agriculture, especially in dairy farming. The objective was also to compare different methods and models - both parametric (stochastic frontier analysis) and non-parametric (data envelopment analysis) - in estimating the components of productivity growth and the sensitivity of results with respect to different approaches. The parametric approach was also applied in the investigation of various aspects of heterogeneity. A common feature of the first three of five articles is that they concentrate empirically on technical change, technical efficiency change and the scale effect, mainly on the basis of the decompositions of Malmquist productivity index. The last two articles explore an intermediate route between the Fisher and Malmquist productivity indices and develop a detailed but meaningful decomposition for the Fisher index, including also empirical applications. Distance functions play a central role in the decomposition of Malmquist and Fisher productivity indices. Three panel data sets from 1990s have been applied in the study. The common feature of all data used is that they cover the periods before and after Finnish EU accession. Another common feature is that the analysis mainly concentrates on dairy farms or their roughage production systems. Productivity growth on Finnish dairy farms was relatively slow in the 1990s: approximately one percent per year, independent of the method used. Despite considerable annual variation, productivity growth seems to have accelerated towards the end of the period. There was a slowdown in the mid-1990s at the time of EU accession. No clear immediate effects of EU accession with respect to technical efficiency could be observed. Technical change has been the main contributor to productivity growth on dairy farms. However, average technical efficiency often showed a declining trend, meaning that the deviations from the best practice frontier are increasing over time. This suggests different paths of adjustment at the farm level. However, different methods to some extent provide different results, especially for the sub-components of productivity growth. In most analyses on dairy farms the scale effect on productivity growth was minor. A positive scale effect would be important for improving the competitiveness of Finnish agriculture through increasing farm size. This small effect may also be related to the structure of agriculture and to the allocation of investments to specific groups of farms during the research period. The result may also indicate that the utilization of scale economies faces special constraints in Finnish conditions. However, the analysis of a sample of all types of farms suggested a more considerable scale effect than the analysis on dairy farms.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Dimeric phenolic compounds lignans and dilignols form in the so-called oxidative coupling reaction of phenols. Enzymes such as peroxidases and lac-cases catalyze the reaction using hydrogen peroxide or oxygen respectively as oxidant generating phenoxy radicals which couple together according to certain rules. In this thesis, the effects of the structures of starting materials mono-lignols and the effects of reaction conditions such as pH and solvent system on this coupling mechanism and on its regio- and stereoselectivity have been studied. After the primary coupling of two phenoxy radicals a very reactive quinone me-thide intermediate is formed. This intermediate reacts quickly with a suitable nucleophile which can be, for example, an intramolecular hydroxyl group or another nucleophile such as water, methanol, or a phenolic compound in the reaction system. This reaction is catalyzed by acids. After the nucleophilic addi-tion to the quinone methide, other hydrolytic reactions, rearrangements, and elimination reactions occur leading finally to stable dimeric structures called lignans or dilignols. Similar reactions occur also in the so-called lignification process when monolignol (or dilignol) reacts with the growing lignin polymer. New kinds of structures have been observed in this thesis. The dimeric com-pounds with so-called spirodienone structure have been observed to form both in the dehydrodimerization of methyl sinapate and in the beta-1-type cross-coupling reaction of two different monolignols. This beta-1-type dilignol with a spirodienone structure was the first synthetized and published dilignol model compound, and at present, it has been observed to exist as a fundamental construction unit in lignins. The enantioselectivity of the oxidative coupling reaction was also studied for obtaining enantiopure lignans and dilignols. A rather good enantioselectivity was obtained in the oxidative coupling reaction of two monolignols with chiral auxiliary substituents using peroxidase/H2O2 as an oxidation system. This observation was published as one of the first enantioselective oxidative coupling reaction of phenols. Pure enantiomers of lignans were also obtained by using chiral cryogenic chromatography as a chiral resolution technique. This technique was shown to be an alternative route to prepare enantiopure lignans or lignin model compounds in a preparative scale.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Transposable elements, transposons, are discrete DNA segments that are able to move or copy themselves from one locus to another within or between their host genome(s) without a requirement for DNA homology. They are abundant residents in virtually all the genomes studied, for instance, the genomic portion of TEs is approximately 3% in Saccharomyces cerevisiae, 45% in humans, and apparently more than 70% in some plant genomes such as maize and barley. Transposons plays essential role in genome evolution, in lateral transfer of antibiotic resistance genes among bacteria and in life cycle of certain viruses such as HIV-1 and bacteriophage Mu. Despite the diversity of transposable elements they all use a fundamentally similar mechanism called transpositional DNA recombination (transposition) for the movement within and between the genomes of their host organisms. The DNA breakage and joining reactions that underlie their transposition are chemically similar in virtually all known transposition systems. The similarity of the reactions is also reflected in the structure and function of the catalyzing enzymes, transposases and integrases. The transposition reactions take place within the context of a transposition machinery, which can be particularly complex, as in the case of the VLP (virus like particle) machinery of retroelements, which in vivo contains RNA or cDNA and a number of element encoded structural and catalytic proteins. Yet, the minimal core machinery required for transposition comprises a multimer of transposase or integrase proteins and their binding sites at the element DNA ends only. Although the chemistry of DNA transposition is fairly well characterized, the components and function of the transposition machinery have been investigated in detail for only a small group of elements. This work focuses on the identification, characterization, and functional studies of the molecular components of the transposition machineries of BARE-1, Hin-Mu and Mu. For BARE-1 and Hin-Mu transpositional activity has not been shown previously, whereas bacteriophage Mu is a general model of transposition. For BARE-1, which is a retroelement of barley (Hordeum vulgare), the protein and DNA components of the functional VLP machinery were identified from cell extracts. In the case of Hin-Mu, which is a Mu-like prophage in Haemophilus influenzae Rd genome, the components of the core machinery (transposase and its binding sites) were characterized and their functionality was studied by using an in vitro methodology developed for Mu. The function of Mu core machinery was studied for its ability to use various DNA substrates: Hin-Mu end specific DNA substrates and Mu end specific hairpin substrates. The hairpin processing reaction by MuA was characterized in detail. New information was gained of all three machineries. The components or their activity required for functional BARE-1 VLP machinery and retrotransposon life cycle were present in vivo and VLP-like structures could be detected. The Hin-Mu core machinery components were identified and shown to be functional. The components of the Mu and Hin-Mu core machineries were partially interchangeable, reflecting both evolutionary conservation and flexibility within the core machineries. The Mu core machinery displayed surprising flexibility in substrate usage, as it was able to utilize Hin-Mu end specific DNA substrates and to process Mu end DNA hairpin substrates. This flexibility may be evolutionarily and mechanistically important.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Seminal plasma (SP) is the fluid portion of semen, secreted by the epididymides and the accessory glands before and during ejaculation. The stallion s ejaculate is a series of jets that differ in sperm concentration, semen volume and biochemical composition. Before the actual ejaculation, a clear and watery pre-sperm fluid is secreted. The first three jets form the sperm-rich fractions, and contain ¾ of the total number of sperm. The semen volume and sperm concentration in each of the jets decrease towards the end of the ejaculation, and the last jets are sperm-poor fractions with a low sperm concentration. The aims of these studies were to examine the effects of the different SP fractions, and the presence of SP, on sperm survival during storage. Pre-sperm fluid, and semen fractions with a high (sperm-rich) and low (sperm-poor) sperm concentration were collected in five experiments. The levels of selected enzymes, electrolytes and proteins in different SP fractions were determined. These studies also aimed at assessing the individual variation in the levels of the selected SP components and in the effects of SP on spermatozoa. The association between the components of SP and semen quality, sperm longevity, and fertility was examined with a stepwise linear regression analysis. Compared to samples containing SP during storage, centrifugation and the subsequent removal of SP reduced sperm motility parameters during 24 h of cooled storage in all SP fractions, but sperm membrane integrity was not affected. Some of the measured post-thaw motility parameters were also higher in samples containing SP compared to samples stored without SP. In contrast, the proportion of DNA-damaged spermatozoa was greater in the samples stored with SP than those without SP, and this effect was seen in both sperm-rich and sperm-poor fractions. There were no differences in DNA integrity between fractions stored with SP, but the sperm-rich fraction showed less DNA damage than the sperm-poor fraction after SP removal. The differences between fractions in sperm motility after cooled storage were non-significant. The levels of alkaline phosphatase, acid phosphatase and β-glucuronidase were higher in the sperm-rich fractions compared to the sperm-poor fractions, while the concentrations of calcium and magnesium were higher in sperm-poor fractions than in sperm-rich fractions. The concentrations of sodium and chloride were highest in pre-sperm fluid. In the sperm-poor fraction, the level of potassium was associated with the maintenance of sperm motility during storage. The levels of alkaline and acid phosphatase were associated with sperm concentration and the total number of spermatozoa in the ejaculates. None of the measured SP components were correlated to the first cycle pregnancy rate. In summary, the removal of SP improved DNA integrity after cooled storage compared with samples containing SP. There were no differences in the maintenance of sperm motility between the sperm-rich and sperm-poor fractions and whole ejaculates during cooled storage, irrespective of the presence of SP. The lowest rate of DNA damage was found in the sperm-rich fractions stored without SP. In practice, the results presented in this thesis support the use of individual modifications of semen processing techniques for cooled transported semen from subfertile stallions.