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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.
31

Eficiência de inseticidas químicos e associação com o fungo Isaria javanica sobre ninfas e adultos de mosca-branca / Efficiency of chemical insecticides and association with Isaria javanica fungus on whitefly nymphs and adults

Santos, Tássia Tuane Moreira dos 21 February 2017 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-24T12:07:34Z No. of bitstreams: 2 Dissertação - Tássia Tuane Moreira dos Santos - 2017.pdf: 1707301 bytes, checksum: 711b52250570075b4b92d21dd0f3edc0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-24T12:08:10Z (GMT) No. of bitstreams: 2 Dissertação - Tássia Tuane Moreira dos Santos - 2017.pdf: 1707301 bytes, checksum: 711b52250570075b4b92d21dd0f3edc0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-24T12:08:10Z (GMT). No. of bitstreams: 2 Dissertação - Tássia Tuane Moreira dos Santos - 2017.pdf: 1707301 bytes, checksum: 711b52250570075b4b92d21dd0f3edc0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-21 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The main damage of whitefly Bemisia tabaci biotype B on beans is virus transmission such as Bean golden mosaic virus (BGMV) and Cowpea mild mottle virus (CpMMV). Different insecticides mechanisms of action, use of selective molecules and alternative methods of control are important techniques for management of this insect. Therefore, this study was conducted to test the efficiency of chemical insecticides on mortality of whiteflies adults and CpMMV transmission on BGMV-resistant transgenic common bean; and to verify the combination of chemical insecticides in sublethal doses with the entomopathogeni fungus Isaria javanica on control of B. tabaci nymhps in commom bean. In first part of the study two experiments were conducted with seed treatments, one with foliar application and another with the combination with seed treatment and foliar application. Experiments were conducted in screenhouse. In first experiment with seeds treatment thiametoxam FS at 300, 500, 700 mL and imidacloprid+thiodicarb FS at 500, 600 e 800 mL were tested. In second experiment were used higher doses of thiametoxam FS (500, 700 e 900 mL) and imidacloprid+thiodicarb FS (600, 800 e 1.000 mL). In foliar application were evaluated the insecticides thiamethoxam+cyantraniliprole WG and flupyradifurone SL at 500 e 750 mL ha-1, thiamethoxam + lambda-cyhalothrin SC and thiamethoxam WG both at 300 mL ha-1. In combination of seed treatment and foliar application the treatments were plants treated only with seed treatment or with ST following 1, 2, 3 or 4 foliar applications with different insecticides at five-days intervals. On second stage, at laboratory the compatibility of spiromesifen and buprofezin with I. javanica was observed. Different insecticides concentrations (12.5; 25; 50 and 100 ppm) were added to conidia suspension. Germination of conidia, mycelial growth and conidial production were evaluated. On screenhouse were determined: 1) the sublethal (CL25) doses of insecticides spiromesifen and buprofezin to 2nd ínstar whitefly nymphs; 2) the bio-efficacy of different isolates of I. javanica to 2nd ínstar whitefly nymphs and 3) the effect of the combination between spiromesifen and buprofezin with I. javanica on control of 2nd ínstar whitefly nymphs. Nymphal mortality and sporulation on cadavers (2 and 3) were evaluated. As result was observed that thiametoxam + ciantraniliprole WG and flupiradifurone SL applied in foliar application resulted in higher mortality of whitefly adults. ST added 3 or 4 foliar application proportioned the highest mortality and reduction on CpMMV transmission. Insecticides are efficient on B. tabaci control; however, it does not avoid the virus transmission. The combinations of ST added 3 or 4 foliar application reduce the CpMMV on 50%. All I. javanica isolates caused nymphal mortalities. Spiromesifen and buprofezin were compatible with I. javanica. Additive and synergistic effects were observed. A management program of whitefly is important to reduction of CpMMV incidence on BGMV-resistant transgenic common bean. Besides, the combination of selective chemical insecticides and I. javanica on B. tabaci might increase the success of control. / O principal dano da mosca-branca Bemisia tabaci biótipo B na cultura do feijoeiro é a transmissão de vírus, como o Bean golden mosaic virus (BGMV) e o Cowpea mild mottle virus (CpMMV). A rotação de mecanismos de ação dos inseticidas, o uso de moléculas seletivas e de métodos de controle alternativos são técnicas importantes para o manejo deste inseto. Os objetivos do estudo foram testar a eficiência de inseticidas químicos na mortalidade de adultos de mosca-branca e na transmissão de CpMMV no feijoeiro geneticamente modificado resistente ao mosaico dourado (RMD) e a associação de inseticidas químicos em doses subletais com o fungo Isaria javanica no controle de ninfas de B. tabaci em feijoeiro-comum. Na primeira etapa do estudo em casa telada, dois experimentos foram realizados com tratamento de sementes, um com aplicação foliar e outro com a combinação de tratamento de sementes e aplicação foliar. No primeiro experimento com tratamento de sementes (TS) os inseticidas thiametoxam FS nas doses 300, 500, 700 mL e imidacloprid+thiodicarb FS nas doses 500, 600 e 800 mL foram testados. Já no segundo TS foram utilizados doses maiores de thiametoxam FS (500, 700 e 900 mL) e de imidacloprid+thiodicarb FS (600, 800 e 1000 mL). Em pulverização foram avaliados os inseticidas thiamethoxam+cyantraniliprole WG (500 e 750 mL ha-1), flupyradifurone SL (500 e 750 mL ha-1), thiamethoxam+lambda-cyhalothrin SC (300 mL ha-1) e thiamethoxam WG (300 mL ha-1). Na combinação de tratamento de sementes e aplicação foliar, as plantas foram tratadas apenas com TS ou com TS seguido de 1, 2, 3 ou 4 pulverizações com diferentes inseticidas a cada 5 dias. Na segunda etapa para verificar a compatibilidade dos inseticidas spiromesifen e buprofezin com o I. javanica, concentrações destes inseticidas (12,5; 25; 50 e 100 ppm) foram adicionadas à suspensão de conídios. Foram avaliados a germinação de conídios, crescimento micelial e produção de conídios. Em casa telada foram determinados: 1) a dose subletal (CL25) dos inseticidas spiromesifen e buprofezin a ninfas de mosca-branca; 2) a bio-eficácia de isolados de I. javanica à ninfas de mosca-branca; e 3) o efeito da combinação de spiromesifen e buprofezin e I. javanica no controle de ninfas de mosca-branca. A mortalidade das ninfas e a esporulação nos cadáveres (2 e 3) foram avaliadas. No primeiro estudo o tiametoxam+ciantraniliprole WG e flupiradifurona SL em pulverização foliar resultaram em maiores mortalidades de mosca-branca. Os inseticidas são eficientes no controle de mosca-branca. Apenas a combinação de TS mais 3 ou 4 pulverizações foliares reduzem a incidência de CpMMV. No segundo estudo, todos os isolados causaram morte de ninfas. Os inseticidas foram compatíveis com I. javanica. Efeitos aditivo e sinérgico foram observados entre I. javanica e spiromesifen e buprofezin no controle de ninfas de mosca-branca. Um programa de manejo de B. tabaci é importante para a redução de CpMMV no feijoeiro RMD. Além disso, a combinação de inseticidas sintéticos seletivos e o fungo I. javanica pode aumentar o sucesso do controle de ninfas de mosca-branca.
32

Caracterização biológica, serológica e molecular de uma estirpe do Passion Fruit Woodiness Virus (PWV) que infecta sistemicamente algumas cucurbitáceas. / Biological, serological and molecular characterization of an isolate of passion fruit woodiness virus (pwv) that infect some cucurbit plants systemically.

Ricardo Gioria 12 September 2003 (has links)
Este trabalho apresenta resultados da caracterização biológica, serológica e molecular de um potyvirus que causa mosqueado foliar em maracujazeiro e infecta, experimentalmente, plantas de abobrinha-de-moita (Cucurbita pepo cv. Caserta). Esse potyvirus foi inicialmente observado em extratos de folhas de maracujazeiro e em cortes ultra finos de tecidos infectados de abobrinha-de-moita, em microscopia eletrônica. Além de partículas alongadas, observaram-se inclusões lamelares do tipo catavento, características de espécies de vírus do gênero Potyvirus. Após purificação a partir de folhas de maracujazeiro com mosqueado, as partículas desse potyvirus foram dissociadas para a caracterização dos seus principais componentes. O RNA viral apresentou peso molecular de aproximadamente 10000 pb. O peso molecular da proteína da capa protéica foi de aproximadamente 32 kDa. Antissoro policlonal produzido em coelho reagiu com o antígeno homólogo, bem como com o Passion fruit woodiness virus (PWV), em teste de PTA-ELISA, mas não reagiu com dois potyvirus que infectam cucurbitáceas, Papaya ringspot virus - type W e Zucchini yellow mosaic virus. O antissoro contra o PWV reagiu com o potyvirus do mosqueado do maracujazeiro. Quando três isolados do potyvirus do mosqueado do maracujazeiro (M1, M2 e M3) foram inoculados em 37 espécies vegetais, juntamente com dois isolados do PWV (PWV-1 e PWV-2), constatou-se que todas as espécies infectadas pelos isolados do PWV também o foram com os isolados do potyvirus do mosqueado. Estes últimos, entretanto, também foram capazes de infectar sistemicamente plantas de abobrinha-de-moita cv. Caserta e de abóbora híbrida do tipo Tetsukabuto, o que não ocorreu com os isolados do PWV. Testes de transmissão do isolado M1 do potyvirus do mosqueado, por meio mecânico e com os afídeos Myzus persicae e Aphis gossypii, de plantas de maracujazeiro, abobrinha-de-moita, feijoeiro BT 2 e crotalária, para plantas das mesmas espécies foram positivos. No entanto, observou-se que a eficiência de transmissão foi influenciada pela planta fonte de inóculo. Quando a abobrinha-de-moita foi utilizada como fonte de inóculo, a transmissão só ocorreu para plantas-teste dessa espécie, independente do processo de inoculação. Testes de proteção entre os isolados do potyvirus do mosqueado e do PWV, em plantas de Crotalaria juncea, juntamente com a análise da seqüência de nucleotídeos do gene da capa protéica e da região terminal 3' não traduzida dos isolados M2 e M3, indicaram que o potyvirus do mosqueado é uma estirpe do PWV que ocorre em São Paulo. Análises moleculares comparativas com outras espécies de Potyvirus indicaram que tanto os isolados do potyvirus do mosqueado como os isolados do PWV têm alta identidade com o Cowpea aphid-borne mosaic virus (CABMV). Esse resultado corrobora relato anterior feito no país e aponta para a necessidade de uma alteração na nomenclatura da espécie do vírus que está freqüentemente associada ao endurecimento dos frutos do maracujazeiro no Brasil. / This work presents results of the biological, serological and molecular characterization of a potyvirus that causes leaf mottling on passion fruit and infects some cucurbit plants experimentally. This potyvirus was initially observed in extracts of passion fruit leaves and in ultra thin sections of infected tissue of Cucurbita pepo L. cv. Caserta, examined in the electronic microscope. Besides flexuous filamentous particles, lamellar inclusions, characteristic of species of potyvirus, were observed in infected tissue. After purification from infected passion fruit leaves, virus particles were dissociated for the molecular characterization of their main components. The viral RNA showed a molecular weight of approximately 10000 bp. The molecular weight of the coat protein was nearly 32 kDa. Policlonal antibody, produced in rabbit, reacted with the homologous antigen, as well as with Passion fruit woodiness virus (PWV), in PTA-ELISA. No reaction was observed with Papaya ringspot virus - type W and Zucchini yellow mosaic virus, two potyviruses usually found infecting plants in the Cucurbitaceae family. The antibody against PWV reacted with the passion fruit mottling potyvirus. When three isolates of the passion fruit leaf mottling potyvirus (M1, M2 and M3) and two isolates of PWV were separately inoculated in 37 vegetable species, it was verified that all the species infected with the PWV isolates were also infected with the isolates of the passion fruit leaf mottling potyvirus. Isolates M1, M2 and M3, however, were also capable to infect systemically plants of zucchini squash cv. Caserta and hybrid squash Tetsukabuto, which were not infected with the PWV isolates. Transmission tests showed that the M1 isolate of passion fruit leaf mottling potyvirus was efficiently transmitted from infected plants of passion fruit, zucchini squash, Phaseolus vulgaris cv. BT 2 and Crotalaria juncea to plants of the same species by means of mechanical inoculation. Efficient transmission was also obtained when the aphids Myzus persicae and Aphis gossypii were used as vectors. However, the transmission efficiency was influenced by the plant source of inoculum. When zucchini squash was used as a source of inoculum, the transmission only occurred for plants of the same specie, independent of the method of inoculation. Cross protection tests with isolates of the passion fruit leaf mottling potyvirus and PWV, in plants of C. juncea, together with the analysis of the nucleotide sequences of the coat protein (CP) gene and the 3' non translated region (NTR) of the isolates M2 and M3, indicated that the leaf mottling potyvirus has high identity with the PWV present in São Paulo State. As compared with other species of the genus Potyvirus, isolates of both potyviruses showed high identity with the CP gene and 3' NTR of Cowpea aphid-borne mosaic virus (CABMV). This result corroborates previous report regarding to the identity between Brazilian PWV isolates and CABMV and it points for the need of an alteration in the nomenclature of the virus species frequently associated to passion fruit woodiness in Brazil.
33

THE USE OF ALTERNATIVE NORMALIZATION APPROACHES TO UNDERSTAND CHANGES IN SARS-CoV-2 CONCENTRATIONS IN WASTEWATER

Isaksson, Frida January 2022 (has links)
Following the detection of SARS-CoV-2 RNA fragments in wastewater in March 2020, the use of wastewater-based epidemiology is rapidly emerging as a non-invasive approach to assessing community wide COVID-19 prevalence. Wastewater-based epidemiology is promoted as a complement to clinical testing in terms of improving public health authorities’ preparedness and supporting them in taking required interventions to protect the public health.  To utilize the occurrence of SARS-CoV-2 in wastewater in a public health context and evaluate trends in viral prevalence on a community level, robust data interpretation is required. This master's thesis work examines what is currently known about the factors that influence the concentrations of SARS-CoV-2 in wastewater, as well as the impact of alternative normalization approaches on the relationship between viral wastewater data and clinical case numbers. The work is divided into two parts where this report provides a state-of-the-art review as well as an overview of key findings in the accompanied scientific paper.  The study involved collection of wastewater samples from two different sized wastewater treatment plants (WWTPs) in Luleå municipality, between January and March 2021.  Concentrations of SARS-CoV-2 RNA were quantified in each sample as well as concentrations of total nitrogen (TN), total phosphorus (TP) and pepper mild mottle virus (PMMoV). Average daily WWTP flow and environmental data (precipitation and temperature) were continuously measured over the sampling period. The population size was estimated based on mass loads of TN and TP and literature values of the domestic contribution of these parameters to the sewer system. The viral wastewater data was normalized using the estimations of population size, census data, WWTP flow and PMMoV. The impact of the alternative normalization approaches was evaluated using statistical analyses to explore the relationship to clinical case numbers.  The result showed that the strength of the correlation between the different normalization approaches and clinical case data differed between the WWTPs. However, within each WWTP the differences in correlation between the different normalization approaches and clinical cases were not significant. Moreover, normalization using WWTP flow (i.e., viral loads) showed a stronger correlation to clinical cases compared to population and PMMoV normalized viral loads. However, when comparing wastewater data between the two catchment areas, the normalization approaches utilizing population (either census or TN and TP estimated population) or PMMoV better reflect the number of clinical cases. Additionally, according to time-shifted analysis, wastewater data of SARS-CoV-2 RNA predated an increase in clinical cases by 0-2 and 5-8 days, respectively, for the larger and smaller WWTPs.
34

Evaluating the pressure pulse in a flexographic printing press : Linking process parameters to specific pulse shapes / Utvärdering av tryckpulsen i en flexografisk tryckpress

Hedström, Anton January 2023 (has links)
In the printing industry quality is key, this is because a product is printed for a better appearance or to convey information. If the packaging for a product looks bad customers will get a bad first impression of the product. The quality of the print can be affected by many different factors. The material properties of the paperboard such as stiffness, surface roughness, and thickness. It could also be affected by the coating of the paperboard, the properties of the ink, the material properties of the printing form, etc.  In this thesis, the effect of the contact time and the maximum pressure in the nip of a flexographic printing press was studied. To separate these variables six different desirable pressure pulses were decided upon. Three of them where the contact time remains constant while the maximum pressure changes, and three other pulses where the maximum pressure is constant while the contact time changes. The printing was done in an IGT F1 laboratory printing press. The different pressure pulses were achieved by using three different printing forms and varying the force settings in the printing press. The mottle results from the mottle analysis do not show a clear reliance on the contact time or maximum pressure. Instead, the stiffness of the printing forms influences the results to such an extent that it overshadows any effect that the contact time or maximum pressure has. In the case of dot gain, it can be determined that a larger impression leads to more dot gain. However here the stiffness of the printing plays a large role, and no clear conclusions can be drawn when strictly comparing contact time or maximum pressure. / Inom den grafiska industrin är kvalitet avgörande, detta eftersom en produkt trycks för att se bra ut eller för att förmedla ett budskap. Om förpackningen för en produkt ser dålig ut så får kunderna ett dåligt första intryck av produkten. Kvaliteten på trycket kan påverkas av många olika faktorer. Kartongens materialegenskaper såsom styvhet, ytjämnhet och tjocklek. Det kan också påverkas av kartongens beläggning, bläckets egenskaper, tryckplåtens materialegenskaper etcetera. I denna uppsats undersöktes effekten av kontakttiden och det maximala trycket i trycknypet i en flexografisk tryckpress. För att separera dessa variabler bestämdes sex olika önskvärda tryckpulser. Tre av dem var pulser med konstant kontakttid medan det maximala trycket justeras, och tre andra pulser där det maximala trycket hölls konstant medan kontakttiden justerades. Experimenten genomfördes i en IGT F1 laboratorietryckpress. De olika tryckpulserna uppnåddes genom att använda tre olika tryckplåtar och variera kraftinställningarna i tryckpressen. Analysen av provens flammighet visar inte ett tydligt beroende av kontakttiden eller maximalt tryck. Det är i stället tryckplåtarnas styvhet som påverkar resultaten mest, de påverkar resultaten i en sådan stor utsträckning att det inte går att dra några slutsatser om kontakttiden och det maximala tryckets påverkan på resultatet. Från resultaten av punktförstoring kan slutsatsen dras att högre intryckning ger mer punktförstoring. Men även i detta fall så spelar styvheten för tryckplåtarna väldigt stor roll och inga slutsatser kan dras för vare sig kontakttid eller maximalt tryck.
35

Variations Related to Print Mottle in Starch-Containing Paper Coatings

Ragnarsson, Micael January 2012 (has links)
Starch in paper coatings is known to increase the risk of print mottle in lithographic offset printing. The objective of this study was to increase the understanding of this behaviour. Four phenomena that could lead to print mottle, where the presence of starch might be important, have been identified: uneven binder migration, uneven coating mass distribution, uneven deformation during calendering and differential shrinkage. The latter three were investigated in this project. Starch-containing coating colours often have high water retention. A relationship between the water retention of the coating colours and the distribution of coating thickness was found in a pilot trial. A theory is proposed, where the surface profile of the base paper beneath the blade, that governs the coat weight distribution in blade coating, is affected by moisture from the dewatering coating colours and the compressive force exerted by the blade. Drying strategies were studied to see whether they would induce porosity variations in the coating layers. There is a strong connection between the rate of evaporation and the shrinkage of the coating layer, but no porosity variations due to the choice of drying strategy were found. Shrinkage is governed by the capillary forces. At the same capillary pressure, the coating shrinks more for some binder systems, which is suggested to be due to a weaker chemical interaction between the binder and the pigment. Oxidized starch/latex coatings, stained with a fluorescent marker, had a greater standard deviation in fluorescence intensity than CMC/latex coatings caused by a difference in either porosity or latex distribution. It was shown that calendering introduces porosity variations into the coating layer that are larger for starch-containing coatings. The drying strategies appeared to have a significant effect on these porosity variations and they correlated positively with print mottle in some cases and in another case negatively. In the case of the negatively correlated, the mottle was probably caused by variations in surface porosity existing prior to the calendering.

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