436 research outputs found

    Fertimetro, a Principle and Device to Measure Soil Nutrient Availability for Plants by Microbial Degradation Rates on Differently-Spiked Buried Threads

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    A novel patented method (PCT/IB2012/001157: Squartini, Concheri, Tiozzo, University of Padova) and the corresponding application devices, suitable to measure soil fertility, are presented. The availability or deficiency of specific nutrients for crops is assessed by monitoring the kinetics of progressive weakening of cotton or silk threads due to in situ microbial activity. The method is based on a nutrient-primed incremented substrate degradation principle. Threads are buried as is or pre-impregnated with N or P solutions, and the acceleration of the degradation rate for the N-supplemented or P-supplemented thread, in comparison to the untreated thread, is proportional to the lack of the corresponding nutrient in that soil. Tests were validated on corn crops in plots receiving increasing fertilizer rates in a historical rotation that has been established since 1962. The measurement carried out in May significantly correlated with the subsequent crop yields recorded in October. The analysis allows an early, inexpensive, fast, and reproducible self-assessment at field level to improve fertilization rates. The device is envisaged as a user-friendly tool for agronomy, horticulture, and any environmental applications where organic matter cycling, soil quality, and specific nutrients excess or deficiency are critical considerations

    Chelating carbene ligands and their metal complexes

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    This thesis describes the synthesis of a number of functionalised imidazolium salts as precursors to N- heterocyclic carbenes and their subsequent coordination to Ag and Pd. Further a number of the Pd complexes were tested in the Heck reaction and their activities compared to complexes with similar structural features currently within the literature. A range of imidazolium salts have been synthesised which include quinoline and octahydroacridine moieties and have been characterised by a number of methods including X-ray crystallography. A bis imidazolium salt has also been prepared as a DIOP analogue. The imidazolium salts were successfully reacted with Ag20 to form the NHCAg(I) complexes. The quinoline and octahydroacridine based NHCs were transmetallated to Pd as chelating ligands, the quinoline based systems appearing as planar, strained complexes in the X-ray structure. The activities of the quinoline and octahydroacridine based NHCPd(II) complexes in the Heck coupling of 4-bromoacetophenone and 4-chlorobenzaldehyde with n-butyl acrylate were assessed and found to be comparable to similar systems with low to satisfactory conversions.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    New enzymatic method for the determination of total phenolic content in tea and wine

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    A new spectrophotometric enzymatic method for the determination of total phenol content in tea and wine has been developed. The method is based on the peroxidase-catalyzed oxidation, by hydrogen peroxide, of phenols to phenoxyl radicals, which can react with aromatic substrates to form intensely colored adducts. In comparison with the widely used Folin-Ciocalteu method, this method appears to be more specific and more rapid and as a whole is not affected by the common interfering substances such as ascorbate, citrate, and sulfite. Numerous samples of teas and wines were analyzed by using the new method, and the results compared with those obtained by using the Folin and scavenging of DPPH methods. The differences of the total phenols content found by applying the three methods are discussed in terms of the different specificities of the analytical basis

    Ultrasound-assisted cold pasteurization in liquid or SC-CO2

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    Various types of chemical and physical protocols are used, thermal treatment in particular, to increase the quality of bulk food products (for example, dates or some sort of nuts) and extend shelf life, and combinations of methods are frequently used to achieve the best results. However, the use of these processing methods is not always the best option to preserve the initial taste and appearance of food products. For instance, a product may lose its initial natural appearance and acquire different flavors due to chemical transformations that occur at certain temperatures or when the products are treated with chemicals. Non-thermal treatment methods are called “cold” pasteurization. This is a set of advanced techniques that are based on physical and chemical effects that do not result in the structural food-product transformations caused by heating. We have developed and tested a new technique for efficient food-product processing and cold pasteurization in an ultrasonic field under pressure in an atmosphere of supercritical or subcritical carbon dioxide. A laboratory-scale unit that was designed and built for this purpose has experimentally proven the feasibility of this process and demonstrated high efficiency in suppressing pathogenic flora

    Expression of tumour necrosis factors during chick lens development

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    During development of the lens, epithelial cells at the lens equator begin a differentiation process to become secondary fibre cells. The differentiating cells elongate and migrate towards the centre of the lens where they envelop the older, central fibre cells. Differentiation into fibre cells is accompanied by the breakdown of all organelles, such as the mitochondria. All organelle degradation is completed and denucleation occurs at the border of the organelle free zone (OFZ) which contains the central, terminally differentiated, fibre cells. The differentiation pathway is not well characterised, though it is believed to have similarities to an attenuated form of apoptosis supported by the identification of apoptosis related genes, such as TNF, in the lens. This study continues the search for and characterisation of apoptosis related genes expressed during lens development, focusing on TNFs and their extended family. Reverse Transcriptase-(RT-) PCR was carried out, identifying a number of TNF and extended family member genes in the chick lens, expression studies established novel, statistically significant differential expression for TRAF2 and TRAF3. TRAF2 protein expression from western blotting, similar to RT-PCR expression was found to decline as the lens developed. TRAF2 localisation studies showed limited expression in the equatorial region but there was extensive signalling found in the developing iris, a region in the corneal-scleral boundary and some staining was also detected in the ciliary body. TRAF3 protein and RT-PCR expression were similar, with increasing expression as the lens developed. Western blotting identified two bands and subcellular fractionation confirmed different localisation for the two isoforms. Immunofluorescence identified increasing TRAF3 staining in the cortical fibre cells, this staining was found to be similar to proteins that were reported to be involved in lens fibre cell remodelling and maintenance, suggesting a possibly similar role for TRAF3. Following interest in TRAIL as a gene therapy for Posterior Capsule Opacification (PCO) its expression was examined using RT-PCR and Western blotting which showed low, similar levels of expression throughout the stages of lens development studied. Peroxidase staining showed interesting staining in the equatorial epithelial cells and those just beginning to differentiate at the transition zone. Novel nuclear staining was identified at all time points in both epithelial and fibre cells containing nuclei. Characterisation of whole lens culture was undertaken to discover the optimum culture system for the whole chick lens. Of the published research using whole chick lens culture none stated the basic morphology of the developing lens in organ culture, though each lab had their preferred methodology. The characterisation resulted in the preference of E10 chick lenses being grown with vitreous attached in medium containing glucose. Understanding the morphology of lenses in culture will be invaluable when undertaking the functional studies required to clarify the roles in the lens of the newly identified genes, specifically TRAF2 and TRAF3.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Capital and culture : an investigation into New Labour cultural policy and the European Capital of Culture 2008

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    This thesis is an investigation into the relationship between culture in New Labour policy and within the competition for the European Capital of Culture 2008. The study interrogates a policy paradigm which it identifies as a 'creative city/urban planning' approach to urban regeneration. It locates this approach within a wider New Labour 'Third Way' politics, in that it attempts to reconcile economic instrumentalism with a rhetorical commitment to a politics of the social. Based on elite interviews and documentary analysis, this thesis argues that this approach to urban regeneration draws on a misappropriation of the work of cultural theorist Raymond Williams. It demonstrates how this misappropriation results in an unbounded anthropological definition, whereby culture colonises all areas of economic and social life. Within this template, culture becomes a surrogate economic and social policy. This is illustrated in the case-study of Liverpool's bidding for, winning of and plans for Capital of Culture 2008. This analysis shows how culture without parameters is usurped within both a neo-liberal economic agenda, and a policy template which recasts social inequality as a personal cultural deficit. Within Liverpool's urban strategy, culture is conceived as a social and economic panacea. However, when culture comes to mean everything, it invariably means nothing. This thesis attempts to put Raymond Williams' 'vague and baggy monster' back in its theoretical cage.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    The effect of customer perceived value on customer satisfaction: a case study of Malay upscale restaurants

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    Stiff competition and increasingly high operating costs have driven many international and domestic players to introduce new outlet concepts. Malay fine dining, upscale restaurant segment is gaining popularity among Malaysian, especially in Kuala Lumpur. This study examined the effect of perceived value on customer satisfaction in Malay upscale restaurants in terms of emotional responses, monetary prices, behavioral price and reputation. Primary data were gathered from 170 questionnaires returned by respondents from five Malay upscale restaurants in Kuala Lumpur, and statistically analysed using SPSS version 21. The findings of this study revealed that monetary prices had a high positive relationship with customer satisfaction. In addition, the beta value for emotional responses (β=0.530, p<0.01), behavioral price (β=0.180, p<0.01) and reputation (β=0.168, p<0.01) also indicated the respective contributions made to customer satisfaction

    Study of nuclear targets of phosphatidylinositol-3 kinase in lymphocytes

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    Pathways regulated by Phosphotidylinositide-3-kinase (PI3K) have emerged as important mediators of cell proliferation and survival. When altered, several components of this pathway have been identified to contribute towards a wide range of human malignancies. PI3K has been implicated in the development of several EBV-associated malignancies of both lymphoid and epithelial origin. These include Burkitt's lymphoma, Hodgkin's disease and nasopharyngeal carcinoma. Although progress has been made in dissecting the pathways regulated by PI3K, the key components contributing to lymphocyte transformation have not been fully characterised. This study sought to investigate downstream targets of PI3K in lymphocytes in order to further our understanding of the contribution of PI3K signalling to lymphocyte proliferation and survival, particularly within the context of EBV-associated B-cell lymphomas. Initial work in this study revealed that a component of the mammalian ribosome, S6-ribosomal protein, is a major target for PI3K activation in transformed lymphocytes. In order to study PI3K and EBV regulated proteins on a larger scale, the technology of two-dimensional electrophoresis (2DE) was employed. The use of 2DE in combination with a PI3K inhibitor did not allow the identification of PI3K regulated proteins. However, three EBV regulated proteins were detected in the B-lymphocyte nucleus using this technology. The technology was further developed to study the post-translational modifications of DNA bound transcription factors. This detected multiple isoforms of the cAMP-response element binding protein (CREB), signal transducers and activators of transcription 1 (STAT1) and forkhead box O (FOXO) transcription factors in the nuclei of EBV immortalized lymphocytes. More detailed analysis of the PI3K regulated pro-apoptotic transcription factor, FOXOl, revealed that this protein is downregulated in EBV positive cells at both the transcriptional and translational levels. This downregulation was shown to directly correlate with the protein expression of a known target gene activated by FOXOl, Bcl-6, and to inversely correlate with protein levels of Cyclin D2, a target transcriptionally repressed by FOXOl. Further investigations into the mechanisms by which EBV downregulates FOXOl implicated a role for two EBV encoded proteins, Latent membrane protein-1 (LMP1) and LMP2A in the downregulation of both FOXOl, and its target gene, Bcl-6. In conclusion, this work has explored the use of antibody detection and proteomic techniques for the identification and analysis of nuclear proteins and transcription factors regulated by PI3K and EBV. Together, these investigations have deepened our understanding of the molecular changes that occur in lymphocytes in response to EBV infection, and how EBV may influence malignancy.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    The Exposure to Osteoarthritic Synovial Fluid Enhances the Immunomodulatory Profile of Adipose Mesenchymal Stem Cell Secretome

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    Objective. Several clinical studies have proposed the infusion of adipose mesenchymal stem cells (AMSCs) as an alternative therapy for joint diseases with inflammatory components, such as osteoarthritis. Indeed, AMSCs are able to stimulate tissue repair through a paracrine activity and the interaction with the inflammatory microenvironment seems to have a critical role. Design. To reproduce the inflammatory microenvironment, AMSCs were exposed to osteoarthritic synovial fluid (SF) for 48 h and the effect of their secretome on differentiation of monocytes (M0) into macrophages M1-like and mature dendritic cells (mDCs) was evaluated. Furthermore, the effect of the secretome of AMSCs exposed to SF was evaluated on the T cell population in terms of T cell proliferation and expansion of T regulatory cells (T reg). Results. Our data show that the exposure of AMSCs to SF activates cells and promotes the release of immunosuppressive factors, which induce macrophage polarization of M0 into the M2-like phenotype and inhibit differentiation of monocytes into mature dendritic cells (mDCs). Only the secretome of exposed AMSCs was able to inhibit T cell proliferation and promote T reg expansion. Conclusions. Our results suggest that the microenvironment plays a fundamental role for the development of anti-inflammatory and immunomodulatory properties of AMSCs

    Descarbonizar micro/mini-redes através da complementaridade da produção solar fotovoltaica e eólica

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    RESUMO: Este trabalho apresenta uma metodologia para determinar a capacidade instalada ótima de fontes de energia renováveis variáveis no tempo, numa mini-rede selecionada, e avaliar o potencial destas tecnologias para satisfazer o consumo de eletricidade, permitindo reduzir a dependência de geradores alimentados por combustíveis fósseis. A capacidade ótima é identificada com base na exploração estratégica da sinergia eólica e solar fotovoltaica (FV) para atender à procura de eletricidade, neste caso, para substituir a produção com geradores a diesel. Para este efeito, neste trabalho, explora-se o uso de diferentes ângulos de azimute e inclinação dos sistemas solares fotovoltaicos fixos (convencionais e bifaciais), bem como sistemas com seguimento para criar um portfólio de geração ideal. Os resultados preliminares obtidos destacam que é necessário diversificar a orientação dos painéis solares e explorar a energia eólica para evitar vários períodos com excesso de produção e, consequentemente, corte de geração. Apesar de ser necessário continuar a desenvolver este trabalho, os resultados mostram que o uso dos geradores a diesel pode ser significativamente reduzido, especialmente durante o período diurno.ABSTRACT: This work presents a methodology to determine the optimal share of variable renewable energy sources (vRES) in a selected mini-grid, and evaluate its ability to satisfy electricity demand, allowing to reduce dependence on generators using fossil fuel. The optimal share is identified based on the strategic exploitation of wind and solar photovoltaic (PV) synergies to meet electricity demand, in this case, to replace the production from diesel generators. To this end, in this work, the use of different azimuth and tilt angles for solar PV systems (conventional and bifacial) as well as tracking systems to create an ideal mix is explored. The preliminary results obtained highlight that it is necessary to diversify the orientation of solar panels and explore wind energy to avoid several periods of generation outages. Although it is necessary to continue developing this work, the results show that the use of diesel generators can be significantly reduced, especially during the day.N/
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