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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.
121

Adubação nitrogenada e recomendação com medidor portátil de clorofila em algodão

Santos, Danilo Marcelo Aires dos [UNESP] 04 August 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-04Bitstream added on 2014-06-13T20:39:18Z : No. of bitstreams: 1 santos_dma_me_ilha.pdf: 304690 bytes, checksum: 0178bdbbeca92dbc4df68c46ef62ade9 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo desse presente trabalho foi desenvolver um método de recomendação de adubação nitrogenada com as leituras de clorofilômetro, para o campo, avaliando doses crescentes de N, em algodoeiro cv. DeltaOpal. Foi desenvolvido em dois anos, instalados na Fazenda de Ensino e Pesquisa (FEP), no município de Selvíria - MS, pertencente a Faculdade de Engenharia Campus de Ilha Solteira. Utilizando um delineamento em blocos ao acaso com 4 repetições, utilizando os fatores modo de aplicação (Única e Parcelada), doses de N em cobertura ( 0, 25, 50, 75, 100 kg de N ha-1, para o ano 2004/05) e ( 0, 25, 50, 75, 100 e 120 kg de N ha-1, para o ano 2005/6), a fonte de N foi uréia, a aplicação de N nos tratamentos, foram realizadas, de dois modos: única aos 30 d.a.e. com doses totais e os parcelados com metade da dose aplicada aos 30 d.a.e. e o restante aos 45 d.a.e. As leituras SPAD foram efetuadas na 5ª folha da haste principal e em toda a planta (2005/06), para que, no final do estudo houvesse uma recomendação de N, através das leituras. As doses crescentes de N, proporcionaram uma maior altura da planta, e afetaram positivamente os teores foliares de P, K, e para a produtividade somente houve diferença significativa no primeiro ano agrícola onde se aplicou N de forma parcelada. Com relação às leituras SPAD, houve eficiência em determinar o teor de N presente na planta, podendo ser adotado como metodologia ao determinar carência do N na planta. / The objective of this work was to develop a method of nitrogen recommendation by chorophyll readings, in field conditions, using N levels in cotton cv. DeltaOpal. It was developed during two growth seasons, at the Experimental Station of the São Paulo State University/Unesp/Ilha Solteira Campus, at Selvíria - MS. The Trials have used the completely blocks design with four repetitions, using two factors: a- methods of N application (Single or split), N levels in covering (first year: 0, 25, 50, 75, 100 kg of N ha-1 , second year: 0, 25, 50, 75, 100 and 120 kg of N ha-1). The Nitrogen source was urea applied: a- 30 days after emergency (total amount) and b- 30 and 45 days after emergency (splited). The SPAD readings were realized in the fifth true leaf of the main monopodial branch and in all leaves of this plant. The plant height was affected by the nitrogen levels but the leaf level of P, K, were positively affected. The yield was affected by the nitrogen levels just in the first season. The chorophyll readings showed an useful key to evaluate the nitrogen deficiency in cotton.
122

Quantificação e modelagem de mecanismos de danos causados por Phakopsora euvitis e Plasmopara viticola em videira Vitis labrusca / Quantification and modelling of damage mechanisms caused by Phakopsora euvitis and Plasmopara viticola in Vitis labrusca

Antonio Fernandes Nogueira Júnior 02 February 2017 (has links)
A viticultura no Brasil e no Estado de São Paulo encontra-se em expansão nos últimos 10 anos e a cv. Niagara Rosada (Vitis labrusca) se destaca como principal cultivar para produção de uvas para mesa. Essa cultivar é suscetível à várias doenças foliares, como a ferrugem (Phakopsora euvitis) e o míldio (Plasmopara viticola). Não existem estimativas quantitativas dos danos causados por essas doenças na cv. Niagara Rosada. Diante do exposto os objetivos desse trabalho foram quantificar os efeitos da ferrugem e do míldio nas trocas gasosas, nas limitações da fotossíntese, no acúmulo de biomassa, no acúmulo de carboidratos, e na produção da cv. Niagara Rosada e desenvolver um modelo de simulação para V. labrusca acoplado com os mecanismos de danos da ferrugem e míldio. Experimentos foram conduzidos, separadamente para cada doença, em condições controladas, em mudas inoculadas com diferentes concentrações de P. euvitis e P. viticola e em campo experimental. Medidas de trocas gasosas e curvas de resposta da taxa líquida de assimilação de CO2 ao aumento da concentração intercelular de CO2 (Ci) foram realizadas em mudas sadias e infectadas com P. euvitis e P. viticola. Teores de açúcares solúveis totais, sacarose e amido foram determinados em plantas sadias e inoculadas com os patógenos. P. euvitis e P. viticola reduziram a taxa fotossintética em plantas infectadas tanto na área da lesão como no tecido verde adjacente a lesão (lesão virtual). Valores do parâmetro β, indicativo da lesão virtual, foram de 5,7 e 2,9, respectivamente para P. euvitis e P. viticola. P. euvitis reduziu em 48%, 36% e 67% a atividade da Rubisco (Vcmax), a taxa máxima de transporte de elétrons usados para a regeneraração da RuBP (Jmax) e a condutância do mesofilo (gm), respectivamente, em folhas infectadas. A área foliar e biomassa de raízes em mudas inoculadas com P. euvitis foram reduzidas. Através de análises histopatológicas e da quantificação de amido nas folhas sadias e doentes foi possível observar o acúmulo de amido em regiões adjacentes às pústulas de P. euvitis. Mesmo em baixas severidades da ferrugem já se observam reduções no acúmulo de carboidratos em raízes. P. viticola reduziu Vcmax em 23,5 % em folhas infectadas comparadas às folhas sadias. P. viticola reduziu a biomassa de raízes e quantidade de carboidratos nas raízes de mudas doentes e de plantas no campo em ano de alta severidade da doença. Plantas no campo com sintomas míldio produziram em média 0,5 kg a menos do que plantas sadias e a principal causa da redução na produção foi a queda de bagas causada pela infecção de P. viticola nos cachos. Um modelo de simulação para Vitis labrusca foi desenvolvido, utilizando o software Stella®. A produção, partição e dinâmica da biomassa da videira foi simulada ao longo de 20 anos e os efeitos de P. euvitis e P. viticola na redução do tecido verde sadio da planta, na redução da eficiência fotossintética, no desvio de assimilados, na aceleração da senescência foliar e na queda de frutos foram inseridos no modelo. / Viticulture in Brazil and in the state of São Paulo has increased in the last 10 years and cv. Niagara Rosada (Vitis labrusca) is the main cultivar for the production of table grapes. This cultivar is susceptible to several foliar diseases, such as rust (Phakopsora euvitis) and downy mildew (Plasmopara viticola). There are no quantitative estimates of the damage caused by these pathogens in cv. Niagara Rosada. The objectives of this work were to quantify the effects of rust and downy mildew on gas exchange, photosynthesis limitations, biomass accumulation, carbohydrate accumulation and production of cv. Niagara Rosada and to develop a simulation model for V. labrusca coupled with damage mechanisms caused by rust and mildew. Experiments were conducted, independently for each disease, under controlled conditions in potted plants inoculated with different concentrations of P. euvitis and P. viticola and in experimental field, with natural occurrence of diseases. Measurements of gas exchange and response curves of photosynthetic rate to the increase of the intercellular CO2 concentration (Ci) were carried out in healthy plants and infected plants with P. euvitis and P. viticola. Total soluble sugars, sucrose and starch contents were determined in healthy plants and inoculated plants with the pathogens and kept under controlled conditions. P. euvitis and P. viticola reduced the photosynthetic rate in infected plants both in the area of the lesion and in the green tissue adjacent to the lesion (virtual lesion). Values of parameter β, indicative of the virtual lesion, were 5.8 and 2.9, respectively for P. euvitis and P. viticola. P. euvitis reduced the activity of Rubisco (Vcmax), rate of electrons transport contributing for the RuBP-regeneration (Jmax) and the conductance of mesophyll (gm), respectively, on infected leaves by 48%, 36% and 67%. The severity of P. euvitis reduced leaf area and biomass of plant roots. The histopathological analysis and starch quantification in the leaves allowed to observe starch accumulation in regions adjacent to the pustules of P. euvitis. Even in low disease severities, reductions in carbohydrates accumulation of in roots are already observed. P. viticola reduced Vcmax by 23.5% in infected leaves compared to healthy leaves. P. viticola reduced the root biomass and carbohydrate amounts in the roots of potted plants and plants in the field in the year of high disease severity. Field plants with mildew symptoms produced on average 0.5 kg less than healthy plantsand the main cause of reduction in production was the drop of berries caused by infection of P. viticola in the clusters. A simulation model for Vitis labrusca was developed using Stella ® software. The production, partitioning and dynamics of grapevine biomass was simulated over 20 years and the effects of P. euvitis and P. viticola on the reduction of healthy green plant tissue and photosynthetic efficiency, the assimilative sapper, leaf senescence acceleration and fruit drop were coupled in the model.
123

Explorando a variação genética natural das espécies selvagens relacionadas ao tomateiro no modelo Micro-Tom (Solanum lycopersicum L. cv Micro-Tom) / Exploring natural genetic variation from wild species related to tomato in the Micro-Tom model (Solanum lycopersicum L. cv Micro-Tom)

Fernando Angelo Piotto 01 February 2008 (has links)
As espécies selvagens relacionadas ao tomateiro desenvolveram-se em uma ampla gama de latitudes que compreende o sul do Equador ao norte do Chile, ocupando diferentes habitats e constituindo uma fonte de diversidade genética natural. Essa diversidade tem sido utilizada no melhoramento de tomateiro, sobretudo para introgressão de genes de resistência a patógenos e mais recentemente de genes afetando a qualidade dos frutos. Embora a variação genética natural tenha a relevância de algo que foi selecionado na natureza e que pode ter implicações evolutivas, ela ainda é pouco explorada em estudos básicos. Para o uso intensivo desse recurso é necessário lançar mão de cruzamentos e retrocruzamentos em larga escala entre as espécies selvagens e o tomateiro cultivado (Solanum lycopersicum). Para tanto, dispomos de uma cultivar miniatura de tomateiro, a cv Micro-Tom (MT), a qual pode crescer nas mesmas condições requeridas para a planta modelo Arabidopsis thaliana. Com o uso da cv MT, podemos explorar de forma adequada a variação genética natural das espécies selvagens de tomateiro, sendo que a identificação de alterações fenotípicas é muito mais evidente quando podemos visualizar a planta como um todo. Dessa forma, vários alelos ainda não conhecidos foram resgatados dessas espécies, os quais levam a fenótipos distintos daqueles encontrados nos parentais, tais como frutos cor rosa-salmão vindo de S. neorickii, frutos de superfície opaca vindo de S. chmielewskii e frutos de coloração verde escuro vindo de S. galapagense. Esse modelo parece ser de especial importância para isolar genes de efeito maior. Assim, isolamos um locus vindo de S. pimpinellifolium que aumenta o número de flores por inflorescência da cv MT de 7 para 11. Sendo o tomateiro uma planta cultivada, os alelos oriundos das espécies selvagens, além de úteis para estudos genéticos e fisiológicos, podem ser aproveitados em programas de pré-melhoramento. / Tomato wild species evolved in a wide range of latitudes, from the south of Ecuador to the north of Chile, which comprise different habitats and are a source of natural genetic variation. This diversity is commonly used in tomato breeding, especially for the introgression of genes for resistance to pathogens and, recently, for fruit quality. Although natural genetic variation usually has an adaptive significance, which means that it may have evolutionary implications, it is still poorly explored in basic research. For the intensive utilization of this resource, it is necessary to perform large scale crosses and backcrosses between wild species and cultivated tomato. Aiming to this purpose, we used the miniature tomato cultivar, cv Micro-Tom (MT), which can growth in the same minimum requirements of the Arabidopsis thaliana model. Using MT one can adequately explore the natural genetic variation of wild species with less time and space requirements. In addiction, phenotypical alterations are more evident in MT, since one can easily visualize the whole plant. Thus, alleles hitherto unknown were isolated from tomato wild related species, leading to distinct phenotypes, such as pink-salmon fruits from S. neorickii, opaque fruit surface from S. chmielewskii and dark green fruits from S. galapagense. The MT model seems to be particularly adequate for the isolation of major genes and QTLs of great effects. Thereby, we had isolated a S. pimpinellifolium locus that increases the number of flowers per inflorescence, from 7 to 11, in MT. Being the tomato a cultivated plant, the alleles obtained in the wild species, besides to be useful for genetic and physiological studies, can be used in pre-breeding programs.
124

High-speed continuous-variable quantum key distribution over atmospheric turbulent channels

Qu, Zhen, Djordjevic, Ivan B. 20 February 2017 (has links)
We experimentally demonstrate a RF-assisted four-state continuous-variable quantum key distribution (CV-QKD) system in the presence of turbulence. The atmospheric turbulence channel is emulated by two spatial light modulators (SLMs) on which two randomly generated azimuthal phase patterns are recorded yielding Andrews' azimuthal phase spectrum. Frequency and phase locking are not required in our system thanks to the proposed digital phase noise cancellation (PNC) stage. Besides, the transmittance fluctuation can be monitored accurately by the DC level in this PNC stage, which is free of post-processing noise. The mean excess noise is measured to be 0.014, and the maximum secret key rate of >20Mbit/s can be obtained with the transmittance of 0.85, while employing the commercial PIN photodetectors.
125

Contribução da mucuna-cinza no fornecimento de macronutrientes para a produção de brócolis / Contribution of velvet-bean in the supply of macronutrients for the production of broccolis

Peralta Antonio, Nain 06 July 2018 (has links)
Submitted by MARCOS LEANDRO TEIXEIRA DE OLIVEIRA (marcosteixeira@ufv.br) on 2018-09-26T13:00:41Z No. of bitstreams: 1 texto completo.pdf: 2481174 bytes, checksum: d54d4d260c6e221a09c1d60a926c7bda (MD5) / Made available in DSpace on 2018-09-26T13:00:42Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2481174 bytes, checksum: d54d4d260c6e221a09c1d60a926c7bda (MD5) Previous issue date: 2018-07-06 / Adubação verde pode ser uma alternativa viável do ponto de vista agronômico, econômico, social e ambiental para substituir parcial ou totalmente aos fertilizantes sintéticos. Para testar as hipóteses de que os efeitos promovidos pela adubação mineral sobre a produção, ganho de matéria seca, acúmulo e eficiência de utilização de nutrientes em cultivos sucessivos e características da solução do solo, podem ser igualados pela adubação verde (isolada ou em conjunto com adubo mineral), foram realizados experimentos. Os objetivos froam avaliar a resposta de crescimento, produção, ganho de matéria seca, acumulo e eficiência de utilização dos nutrientes nos cultivos sucessivos de brócolis e braquiária, manejados com mucuna cinza e adubação mineral aplicadas isoladamente ou em conjunto; avaliar as mudanças da acidez ativa, condutividade elétrica e teor de N, P, K, Ca, Mg e S da solução de solo com os diferentes tratamentos de adubação na primeira cultura; assim como, avaliar o efeito residual dos tratamentos sobre a produção de matéria seca e acúmulo de macronutrientes na braquiária e nas características da solução do solo no segundo cultivo. Similar efeito na produção, ganho de matéria seca, acumulo de nutrientes, eficiência de recuperação (ER) e eficiência de utilização (EU) em brócolis obteve-se com adubação verde (5 o 10 t/ha de mucuna cinza) e o controle na primeira cultura. Menor crescimento, produção, matéria seca e ER de macronutrientes obteve-se com adubação verde (5 o 10 t/ha de mucuna cinza) em comparação com adubação mineral na primeira culutra. Adubação verde em conjunto com adubo mineral promove crescimento de plantas, matéria seca, acúmulo, ER e EU de nutrientes semelhante ao obtido adubação mineral na alta dose (100% ou 200% da dose recomendada). Adubação verde (isolada ou em conjunto com adubação mineral) promovem efeito residual na segunda e demostram efeitos a mediano prazo. Maior condutividade elétrica e teor de N, K, Ca, Mg e S na solução do solo ocorre na etapa de crescimento inicial das culturas, maiores valores em solos adubados com fertilizante mineral na primeira cultura e maiores valores em solos adubados com adubação verde (isolado ou combinado) na segunda cultura. / Green manure can be an viable agronomically, economical, social and environmental alternative to partially or totally replace synthetic fertilizers. To test the hypotheses that the effects promoted by mineral fertilization on yield, dry matter gain, accumulation and nutrient utilization efficiency in successive crops and soil solution characteristics can be obtained by green manure (alone or combined), experiments were carried out with objectives to evaluate the response of growth, yield, dry matter gain, accumulation and utilization efficiency of macronutrients in the successive broccoli and brachiaria crops, managed with velvet-bean and mineral fertilization applied alone or in combination; to evaluate the changes of the active acidity, electrical conductivity and N, P, K, Ca, Mg and S contents of the soil solution with the different treatments of fertilization in the first crop; as well as to evaluate the residual effect of the treatments on dry matter production, accumulation and utilization efficiency of macronutrient and soil solution characteristics in the second crop (brachiaria grass). The effect on yield, dry matter gain, nutrient accumulation, recovery efficiency (RE) and efficiency of use (UE) in broccoli was obtained with green manure (5 to 10 t/ha of velvet-bean) and control in first crops. Lower growth, yield, dry matter and RE of macronutrients were obtained with green fertilization (5 or 10 t/ha of velvet-bean) compared to mineral fertilization in the first crop. Green manure in conjunction with mineral fertilizer promotes growth of plants, dry matter, accumulation, RE and UE of nutrients was similar to that obtained mineral fertilization at high dose (100% or 200% of the recommended dose). Green manure (alone or combined) promote residual effect in the second crop and demostred medium- term effects. Higher electrical conductivity and N, K, Ca, Mg and S content in the soil solution occurs in the initial growth stage of the crops, higher values in soils fertilized with mineral fertiilization in the first crop and higher values in soils fertilized with green manure (alone or combined) in the second culture.
126

Extração e consulta de informações do Currículo Lattes baseada em ontologias / Ontology-based Queries and Information Extraction from the Lattes CV

Eduardo Ferreira Galego 06 November 2013 (has links)
A Plataforma Lattes é uma excelente base de dados de pesquisadores para a sociedade brasileira, adotada pela maioria das instituições de fomento, universidades e institutos de pesquisa do País. Entretanto, é limitada quanto à exibição de dados sumarizados de um grupos de pessoas, como por exemplo um departamento de pesquisa ou os orientandos de um ou mais professores. Diversos projetos já foram desenvolvidos propondo soluções para este problema, alguns inclusive desenvolvendo ontologias a partir do domínio de pesquisa. Este trabalho tem por objetivo integrar todas as funcionalidades destas ferramentas em uma única solução, a SOS Lattes. Serão apresentados os resultados obtidos no desenvolvimento desta solução e como o uso de ontologias auxilia nas atividades de identificação de inconsistências de dados, consultas para construção de relatórios consolidados e regras de inferência para correlacionar múltiplas bases de dados. Além disto, procura-se por meio deste trabalho contribuir com a expansão e disseminação da área de Web Semântica, por meio da criação de uma ferramenta capaz de extrair dados de páginas Web e disponibilizar sua estrutura semântica. Os conhecimentos adquiridos durante a pesquisa poderão ser úteis ao desenvolvimento de novas ferramentas atuando em diferentes ambientes. / The Lattes Platform is an excellent database of researchers for the Brazilian society , adopted by most Brazilian funding agencies, universities and research institutes. However, it is limited as to displaying summarized data from a group of people, such as a research department or students supervised by one or more professor. Several projects have already been developed which propose solutions to this problem, including some developing ontologies from the research domain. This work aims to integrate all the functionality of these tools in a single solution, SOS Lattes. The results obtained in the development of this solution are presented as well as the use of ontologies to help identifying inconsistencies in the data, queries for building consolidated reports and rules of inference for correlating multiple databases. Also, this work intends to contribute to the expansion and dissemination of the Semantic Web, by creating a tool that can extract data from Web pages and provide their semantic structure. The knowledge gained during the study may be useful for the development of new tools operating in different environments.
127

Silica Coated Core-Shell Quantum Dot-based Electro-Immunosensor for Interferon Gamma TB Disease Biomarker

Mini, Sixolile January 2020 (has links)
>Magister Scientiae - MSc / Tuberculosis (TB) is a disease that results from infection by Mycobacterium tuberculosis, which is regarded the most common infecting organism. TB has killed countless numbers of people particularly in underdeveloped countries. TB bacteria can remain inactive or in dormant state for years without causing symptoms or spreading to other subjects, but as soon as the immune system of the host becomes weakened, the bacteria become active and infect mainly the lungs along with other parts of body. TB cases are further aggravated by other illnesses that affect the immune system, such as human immune virus (HIV), which is very prevalent in resource-poor countries. Interferon-gamma (IFN-γ) is a TB biomarker that has found to have all the qualities that are needed to help and cure Tuberculosis disease. Early diagnosis and treatment are essential measures for effectively controlling the disease. Traditional microbial culture-based tests are the most common methodologies currently used. Usually, these methods involve cell culture, cell counts, and cell enrichment, but this process is time-consuming and laborious, especially for the slow-growing bacteria like M. tuberculosis. Sputum smear is one of the methods currently used to detect acid fast bacilli (AFB) in clinical specimens or fluorescent staining. It is a cost-effective tool for diagnosing patients with TB and to monitor the progress of treatment especially in developing countries. The traditional method of inoculating solid medium such as Lowerstein-Jensen (L-J) or 7H10/7H11 media is also used currently it is slow and takes 6-8 weeks of incubation to diagnose the infection and further more time to determine the susceptibility patterns. The microscopic observation drug susceptibility (MODS) assay they are also used currently they rely on light microscopy to visualize the characteristic cording morphology of M. tuberculosis in liquid culture. MODS has shorter time to culture positivity (average 8 days) compared with LJ medium (average ~26 days), they are very expensive. The Gen-Probe assay specific for M. tuberculosis complex is a rapid detection that is also used, nucleic acid amplification (NAA) test results can be obtained as fast as in two hours (provided if a positive culture is present); it also has a high sensitivity of 99% and specificity of 99.2%. It holds the disadvantage of needing of positive culture that can take several days. Enzyme-linked immunosorbent assay (ELISA), is a test that uses antibodies and colour change to identify a substance. ELISA is an assay that uses a solid-phase enzyme immunoassay (EIA) to detect the presence of a substance, usually an antigen, in a liquid sample or wet sample. It can be used to detection of Mycobacterium antibodies in tuberculosis. The Amplified Mycobacterium Tuberculosis Direct Test (AMTDT) is used for the detection of M. tuberculosis it enables the amplification and detection of M. tuberculosis rRNA directly from respiratory specimens. The diagnostic methods employing genetechnology based on the amplification of DNA or RNA are expected to improve the speed, sensitivity, and specificity of Mycobacterium tuberculosis detection. TB rapid cultivation detection technique, such as MB/BacT system, BactecMGIT 960 system and flow cytometry. The BACTEC MGIT960 system (Becton Dickinson, Sparks, MD) performs incubation and reading of the tubes continuously inside the machine using a predefined algorithm to interpret the fluorescent signal and giving the results as positive or negative. When performing DST, the BACTEC MGIT960 interprets the results as susceptible or resistant to the antibiotic under study. Results are available within 8 days. A recent meta-analysis of the published studies found high accuracy and high predictive values associated with the use of BACTEC MGIT960. These methods are more sensitive and rapid than the traditional microbial culture-based methods. However, they cannot provide the detection results in real-time and most of these methods are centralized in large stationary laboratories because complex instrumentation and highly qualified technical staff are required. Recently, Food and Drug Administration (FDA) approved two new assays that were introduced. These two assays detect in vitro a specific immune response to M. tuberculosis. These tests are the QuantiFERON-TB Gold In-Tube (Cellestis/Qiagen, Carnegie, Australia) and the T-SPOT.TB assay (Oxford Immunotec, Abingdon, United Kingdom). Both assays use whole blood from the patient and measure the production of interferon gamma after the whole blood is exposed to specific antigens from M. tuberculosis. These tests are based on the knowledge that IFN-γ is a product of an active cell-mediated immune response induced by M. tuberculosis. However, TB detection remains a major obstacle due to several drawbacks of these methods. To date, the number of diagnosis approaches for TB has increased as the disease continues to be a major public health problem worldwide and most conventional detection technologies present difficulties in recognizing the presence of M. tuberculosis, since they are time consuming, do not provide clinically reliable results and significantly lack of sensitivity. This thesis focusedon developing two binary and one ternary-electrochemically quantum dots, all synthesised at room temperature in aqueous media for detecting (IFN-γ). Copper telluride (CuTe) and Zinc telluride (ZnTe) was prepared to check how does the two quantum dot behave individual and also to check on how they behave when they are combined and formed ternary quantum dots (CuZnTe). The electrochemical studies of the binary CuTe quantum dots, ZnTe quantum dots and the ternary CuZnTe core-shell quantum dots reveal that ternary quantum dots were stable and showed a significant enhancement in the conductivity of CuZnTe core-shell solution compared to that of CuTe and ZnTe, all studied in solution. The three different quantum dots were capped with three different capping reagents which are tetraethyl orthosilicate (TEOS), thioglycolic acid (TGA), (3-mercaptopropyl) trimethoxysilane (MPS). In the study, a label-free electrochemical immunosensor for the detection of interferon gamma (IFN-γ) was prepared for the first time using ternary quantum dots. The biosensor consists of water-soluble silica coated Copper Zinc telluride (CuZnTe core-shell) quantum dots conjugated to a gold electrode. The antibody-antigen were then conjugated on the CuZnTe core-shell QD modified gold electrode. Results from synthesis of two different binary quantum dots are also presented in the study and compared to the results of the CuZnTe core-shell QDs. The CuTe quantum dots had a small average size which was confirmed through HRTEM, SAXS and XRD analysis
128

Electrochemiluminescence of novel polyanilino-rutheniumbipyridyl-imidazo phenanthroline and carboxy-difluoroboradiazaindacene luminophores

Molapo, Kerileng Mildred January 2015 (has links)
Philosophiae Doctor - PhD / Electrochemiluminiscence, (ECL), is an electrochemically-induced process that leads to the generation of measurable luminescent signals at the electrode surface. The luminescent signals occur when electrochemically generated intermediates undergo a highly exergonic reaction to produce an electronically excited state that then emits light. Immobilization of the ECL luminophore on an electrode surface provides enhancement of ECL intensity. This work presents results of the feasibility study focused on the application of novel luminophores for electrochemiluminescence (ECL) sensors. The thesis mainly focuses on studying the ECL of polyanilinorutheniumbipyridyl- imidazo phenanthroline and carboxydifluoroboradiazaindancence luminophores. The influence of the synthetic methods on the electrochemical, structural and photophysical properties of poly(8-anilino-lnaphthalene sulphonic acid) (P ANSA) synthesized by electropolymerization (PANSA) and chemical polymerization (PANSA) were studied. Cyclic voltammetry (CV) data revealed that the electrogenerated PANSA contains species of mixed redox states; with evidence of the presence of penigraniline, emeraldine and leucoemeraldine forms of PANSA. In contrast, the CV of PANSA indicated that it is predominantly in the emeraldine form with a reduction potential at approximately + 0.2 V. The presence of emeraldine moiety in PANSA was confirmed from UV-Vis spectroscopy data. A band gap energy value of 2.5 eV was calculated for the emeraldine in PANSA from the UV data. Comparative study of the charge transfer coefficient, DCT, of the two types of PANSA indicated moderate charge propagation in PANSA (DCT = 1.68 ± 0.1 x 10-8 cm2 s-') which was order of magnitude lower than for PANSA (DCT = 1.68 ± 0.3 x 10-7 cm2 s-'). The differences in the structural properties of the two polymers were reflected in their IR spectra, with evidence of C=C and C=N stretching vibrations observed at 2030, 2158 and 2486 cm-I in PANSA, which are absent in PANSA. The mode of synthesis had a modest impact on the photophysics of the polymers, for example PANSA exhibited a luminescent lifetime of9.00 ± 0.05 ns compared with 11.5 ± 0.07 ns for PANSA. However, time resolved emission anisotropy studies gave a rotational correlation time, p, of 13.8 ± 2.47 ns for PANSA compared to 0.633 ± 0.03 ns for its chemically generated analogue. This suggests a much shorter chain length in the PANSA molecule and higher cross-linking or aggregation in PANSA that can limit incorporation of ruthenium complex on the polymer backbone. As a result, electrochemiluminescent films have been formed by electrodepositing polyaniline, PANI, films in the presence of [Ru(bpY)2PIC]2+; bpy is 2,2'-bipyridyl and PIC is (2,2'-bipyridyl)-2( 4- carboxylphenyl) imidazo [4,5 ][ 1,10] phenanthroline in this work. The homogeneous charge transport diffusion coefficient, DCT, for the Ru2+/3+couple within the PANI film is 2.6 ± 0.9 x 10-10 cm2s-l. The large DCT facilitates a fast regeneration of Ru3+and, coupled to a relatively rigid microenvironment, results in a high ECL intensity in the presence oftripropylamine as co-reactant compared to [Ru(bpY)3f+. Significantly, despite the conducting nature of the polymer backbone, the [Ru(bpy)2PICH2]2+ loaded PANI has the highest efficiency, 1.00%, yet reported for a surface confined ruthenium complex. PANI-Ru complex showed to have many properties that make it an ideal luminophore for sensitive and selective analytical methods; however, it would be useful to have other ECL labels that can span a wide range of wavelengths so that simultaneous determination of several analytes in a single sample can be investigated. In this case, the photophysics, electrochemical and electrochemiluminescent properties of a novel 1,3,5,7 -tetramethyl-8-[ (2-fluorophenyl)-6-methoxy-l ,5-naphthyridine-3-carboxy ]-4,4'difluoroboradiazaindace-ne BODIPY -COOH, dye were demonstrated in this work. The photophysics studies revealed that BODIPY -COOH is highly luminescent: exhibiting sharp absorbance bands, intense emission bands and high emission quantum yield. The quantum yield proved to be solvent dependent and was determined to be 0.88 ± 0.02 and 0.60 ± 0.04 in dimethylsulphoxide (DMSO) and acetonitrile (MeCN), respectively. Electrochemiluminescence (ECL) of BODIPYCOOH in solution was generated in the presence of either benzoyl peroxide (BPO) or hydrogen peroxide. The ECL turn-on potential in the presence of BPO was observed at potentials that are greater than - 1.5 V, and when H202 was used the ECL turn-on potential was significantly fine-tuned to less negative potential of - 0.4 V. Electrochemiluminescent thin films of BODIPY -COOH on Pt electrodes exhibited luminescence properties similar to those of the free dye in solution. However, the solution based approach ECL has its own limitations such as loss of signal due to the diffusion of the ECL reagent out of the detection zone. To overcome loss of signal effects, the introduction of cysteamine and cysteine linkers to the BODIPY dye were employed. It was seen that self-quenching was not sufficient to interfere significantly with the film ECL emission properties and thus the BODIPY thin film can be used in ECL applications. Interestingly, the BODIPY film exhibited the strongest luminescence in water and this is potentially useful in ECL application in biological media.
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The Detection of 8-Hydroxy-2'-Deoxyguanosine (8-OHdG) in Artificial Urine

Thompson, Adam M. 15 November 2021 (has links)
No description available.
130

Text ranking based on semantic meaning of sentences / Textrankning baserad på semantisk betydelse hos meningar

Stigeborn, Olivia January 2021 (has links)
Finding a suitable candidate to client match is an important part of consultant companies work. It takes a lot of time and effort for the recruiters at the company to read possibly hundreds of resumes to find a suitable candidate. Natural language processing is capable of performing a ranking task where the goal is to rank the resumes with the most suitable candidates ranked the highest. This ensures that the recruiters are only required to look at the top ranked resumes and can quickly get candidates out in the field. Former research has used methods that count specific keywords in resumes and can make decisions on whether a candidate has an experience or not. The main goal of this thesis is to use the semantic meaning of the text in the resumes to get a deeper understanding of a candidate’s level of experience. It also evaluates if the model is possible to run on-device and if the database can contain a mix of English and Swedish resumes. An algorithm was created that uses the word embedding model DistilRoBERTa that is capable of capturing the semantic meaning of text. The algorithm was evaluated by generating job descriptions from the resumes by creating a summary of each resume. The run time, memory usage and the ranking the wanted candidate achieved was documented and used to analyze the results. When the candidate who was used to generate the job description is ranked in the top 10 the classification was considered to be correct. The accuracy was calculated using this method and an accuracy of 68.3% was achieved. The results show that the algorithm is capable of ranking resumes. The algorithm is able to rank both Swedish and English resumes with an accuracy of 67.7% for Swedish resumes and 74.7% for English. The run time was fast enough at an average of 578 ms but the memory usage was too large to make it possible to use the algorithm on-device. In conclusion the semantic meaning of resumes can be used to rank resumes and possible future work would be to combine this method with a method that counts keywords to research if the accuracy would increase. / Att hitta en lämplig kandidat till kundmatchning är en viktig del av ett konsultföretags arbete. Det tar mycket tid och ansträngning för rekryterare på företaget att läsa eventuellt hundratals CV:n för att hitta en lämplig kandidat. Det finns språkteknologiska metoder för att rangordna CV:n med de mest lämpliga kandidaterna rankade högst. Detta säkerställer att rekryterare endast behöver titta på de topprankade CV:erna och snabbt kan få kandidater ut i fältet. Tidigare forskning har använt metoder som räknar specifika nyckelord i ett CV och är kapabla att avgöra om en kandidat har specifika erfarenheter. Huvudmålet med denna avhandling är att använda den semantiska innebörden av texten iCV:n för att få en djupare förståelse för en kandidats erfarenhetsnivå. Den utvärderar också om modellen kan köras på mobila enheter och om algoritmen kan rangordna CV:n oberoende av om CV:erna är på svenska eller engelska. En algoritm skapades som använder ordinbäddningsmodellen DistilRoBERTa som är kapabel att fånga textens semantiska betydelse. Algoritmen utvärderades genom att generera jobbeskrivningar från CV:n genom att skapa en sammanfattning av varje CV. Körtiden, minnesanvändningen och rankningen som den önskade kandidaten fick dokumenterades och användes för att analysera resultatet. När den kandidat som användes för att generera jobbeskrivningen rankades i topp 10 ansågs klassificeringen vara korrekt. Noggrannheten beräknades med denna metod och en noggrannhet på 68,3 % uppnåddes. Resultaten visar att algoritmen kan rangordna CV:n. Algoritmen kan rangordna både svenska och engelska CV:n med en noggrannhet på 67,7 % för svenska och 74,7 % för engelska. Körtiden var i genomsnitt 578 ms vilket skulle möjliggöra att algoritmen kan köras på mobila enheter men minnesanvändningen var för stor. Sammanfattningsvis kan den semantiska betydelsen av CV:n användas för att rangordna CV:n och ett eventuellt framtida arbete är att kombinera denna metod med en metod som räknar nyckelord för att undersöka hur noggrannheten skulle påverkas.

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