Dollar spot is one of the most common diseases of warm- and cool-season turfgrass stands and is especially devastating on creeping bentgrass (Agrostis stolonifera L.). The fungus Sclerotinia homoeocarpa degrades the foliage by creating silver, dollar-sized depressions of dead and bleached turf. Frequent fungicide applications and cultural management strategies are required throughout the growing season to prevent or reduce severity of this disease. Previous research has demonstrated that ferrous sulfate applied at 48.8 kg ha-1 suppresses dollar spot epidemics without traditional fungicides. In vitro studies showed 100 to 1,000 mg kg-1 of ferrous sulfate directly suppressed S. homoeocarpa growth of an isolate collected from an established, intensively-maintained creeping bentgrass putting green. Genetic diversity of S. homoeocarpa segregates isolates into two groups; strains generally associated with warm-season and cool-season grasses. It is unknown whether isolates of each group react similarly in the presence of ferrous sulfate. Our research explored use rates of ferrous sulfate required to suppress 50% of dollar spot in the field and in vitro. Ferrous sulfate (heptahydrate 20% Fe, Valudor Products Inc) rates in field trials included 0, 4.88, 24.4, 48.8, and 97.6 kg ha-1. Our results indicate a hyperbolic relationship between ferrous sulfate rate and dollar spot reduction. Using this model, 26.4 kg ha-1 reduced dollar spot incidence by 50%. We concluded that ferrous sulfate suppresses 50% of S. homoeocarpa mycelial growth at between 480 and 720 mg L-1 concentration in 0.25 strength potato dextrose agar in vitro, and fungitoxic activity of ferrous sulfate was dependent primarily on historical fungicide inputs at isolate collection sites. The use of ferrous sulfate may supplement traditional fungicide use. Chlorothalonil is the most common fungicide used to suppress dollar spot in turfgrass. Annual site-use limitations of chlorothalonil often prevent turf managers from achieving acceptable dollar spot control throughout the season. It is not known how ferrous sulfate may contribute to a successful chlorothalonil fungicide program. Therefore, we examined whether ferrous sulfate can be used to minimize chlorothalonil requirements through reducing active ingredient concentrations and extending the longevity, while still maintaining acceptable disease control. Chlorothalonil treatments were applied at 0, 2.28, 4.57, 6.86, and 9.16 kg ai ha-1 (Daconil WeatherStik) across plots treated with and without 48.8 kg ha-1 ferrous sulfate applied bi-weekly. Ferrous sulfate reduced the chlorothalonil rates necessary for 80% disease reduction by 36 to 51% across all trials. Additional studies showed that ferrous sulfate applied with chlorothalonil increased duration of disease control by five days and eliminated two seasonal treatments. Our research expands the guidelines for practical ferrous sulfate usage for dollar spot suppression by elucidating the rate-to-disease relationship and providing best management practices involving admixtures with chlorothalonil. / Master of Science / Turfgrass systems offer many environmental and recreational benefits. Managing turfgrass stands that are free of damaging turf pests is essential to providing aesthetically pleasing lawns, golf courses, and sports fields. Creeping bentgrass is one of the most common turfgrass types found on golf course putting greens but is also used on golf course fairways and tee boxes. There are many diseases that can be found on creeping bentgrass when environmental conditions are favorable. Of these diseases, dollar spot is the most common. When dollar spot is present, half-dollar sized spots of bleached turf can be seen. In order to prevent these easily noticeable spots from appearing, fungicide applications are required in a given growing season to prevent the pathogen from infecting. Available fungicides are very effective at providing control but can be very costly. Beyond fungicide use, other research has shown various cultural practices to reduce disease incidence. Previous research has shown that iron sulfate applied to creeping bentgrass can reduce dollar spot epidemics without the use of fungicides. Laboratory studies have shown a similar trend as ferrous sulfate at varying concentrations directly suppressed dollar spot pathogen growth. In both cases, a limited range of ferrous sulfate rates was tested. To obtain more information we explored use rates of ferrous sulfate required to suppress 50% of dollar spot in the field and in vitro. Ferrous sulfate rates in field trials ranged from 0 to 97.6 kg ha⁻¹ . Results from these trials were used to create a hyperbolic regression. Using this model, we were then able to determine that 26.4 kg ha⁻¹ iron sulfate was required to suppress 50% of the dollar spot in the field. For the laboratory studies we concluded that ferrous sulfate suppresses 50% of the dollar spot pathogen mycelial growth between 480 and 720 mg L ⁻¹ iron sulfate concentrated potato dextrose agar. Although there are many different fungicides available for dollar spot control, the active ingredient chlorothalonil is the most common used. Due to the mode of action which chlorothalonil exhibits, it is much less likely that the pathogen causing dollar spot can become resistant. Although resistance is not an issue, governmental annual site-use limitations restrict turf managers from achieving desirable control. The use of iron sulfate in conjunction with chlorothalonil has not been previously studied. Chlorothalonil treatments were applied at a range of labeled use rates across plots treated with and without 48.8 kg ha⁻¹ ferrous sulfate applied bi-weekly. Ferrous sulfate reduced the chlorothalonil rates necessary for disease reduction. If a threshold of 80% is used, up to 50% reduction in chlorothalonil use was observed. Supplemental studies investigating the duration of control achieved by the combination showed an increase of up to 5 days and eliminated the need for two applications across one season. This research fills a huge gap in our knowledge base on the practical use of iron sulfate for dollar spot control.

Reliable thermal modelling approaches are crucial to transformer thermal design and operation. The highest temperature in the winding, usually referred to as the hot-spot temperature, is of the greatest interest because the insulation paper at the hot-spot undergoes the severest thermal ageing, and determines the life expectancy of the transformer insulation. Therefore, the primary objective of transformer thermal design is to control the hot-spot temperature rise over the ambient temperature within certain limit. For liquid-immersed power transformers, the hot-spot temperature rise over the ambient temperature is controlled by the winding geometry, power loss distribution, liquid flow rate and liquid properties. In order to obtain universally applicable thermal modelling results, dimensional analysis is adopted in this PhD thesis to guide computational fluid dynamics (CFD) simulations for disc-type transformer windings in steady state and their experimental verification. The modelling work is split into two parts on oil forced and directed (OD) cooling modes and oil natural (ON) cooling modes. COMSOL software is used for the CFD simulation work For OD cooling modes, volumetric oil flow proportion in each horizontal cooling duct (Pfi) and pressure drop coefficient over the winding (Cpd) are found mainly controlled by the Reynolds number at the winding pass inlet (Re) and the ratio of horizontal duct height to vertical duct width. The correlations for Pfi and Cpd with the dimensionless controlling parameters are derived from CFD parametric sweeps and verified by experimental tests. The effects of different liquid types on the flow distribution and pressure drop are investigated using the correlations derived. Reverse flows at the bottom part of winding passes are shown by both CFD simulations and experimental measurements. The hot-spot factor, H, is interpreted as a dimensionless temperature at the hot-spot and the effects of operational conditions e.g. ambient temperature and loading level on H are analysed. For ON cooling modes, the flow is driven by buoyancy forces and hot-streak dynamics play a vital role in determining fluid flow and temperature distributions. The dimensionless liquid flow and temperature distributions and H are all found to be controlled by Re, Pr and Gr/Re2. An optimal design and operational regime in terms of obtaining the minimum H, is identified from CFD parametric sweeps, where the effects of buoyancy forces are balanced by the effects of inertial forces. Reverse flows are found at the top part of winding passes, opposite to the OD results. The total liquid flow rates of different liquids for the same winding geometry with the same power loss distribution in an ON cooling mode are determined and with these determined total liquid flow rates, the effects of different liquids on fluid flow and temperature distributions are investigated by CFD simulations. The CFD modelling work on disc-type transformer windings in steady state present in this PhD thesis is based on the dimensional analyses on the fluid flow and heat transfer in the windings. Therefore, the results obtained are universally applicable and of the simplest form as well. In addition, the dimensional analyses have provided insight into how the flow and temperature distribution patterns are controlled by the dimensionless controlling parameters, regardless of the transformer operational conditions and the coolant liquid types used.

ABSTRACT Dollar spot is a fungal disease that affects grass, and is caused by the fungus Sclerotinia homoeocarpa. It was discovered for the first time in Scandinavia in 2013. Dollar spot is a very serious disease of grass in the United States and a lot of money is spent to control the fungus. In the present study, dollar spot development in potted turfgrass, caused by four geographically distinct, Scandinavian isolates of S. homoeocarpa, was investigated at three different temperatures; 6 °C, 15 °C and 21 °C. The objective was to identify the lowest temperature of development of disease, and to establish possible differences among the isolates with regard to disease development. The isolates used originated from Denmark, Norway and Sweden. The grass samples that were inoculated with S. homoeocarpa came from two golf courses in Sweden, located in Uppsala and in Gävle, respectively. Turf grass was dug out and placed in pots, and subsequently inoculated with fungal hyphae from cultures of S. homoeocarpa. These pots were individually covered with plastic bags and placed in different climate chambers at set temperatures. At three time points (day 7, 14 and 21), the ratio of area infected grass to total grass-covered area was estimated. After all the results had been analysed, it was concluded that dollar spot had the most severe disease development at 6 °C. Differences in disease development of dollar spot were also observed among the four isolates at different temperatures. There was a link between geographical origin of an isolate and its optimum temperature for disease development, which may suggest that the isolates can have adapted to the environment in which they have established themselves. S. homoeocarpa is apparently able to proliferate at low temperatures. The present study demonstrates it should be able to infect grass and establish in turf grass even in a colder climate, and thus it is very likely that dollar spot has gained a foothold in Scandinavia, and that it is here to stay. With climate change taking place, i.e. increasing temperatures and precipitation, which in turn results in elevated humidity, the disease will be able to establish and spread yet more, because the fungus thrives in humid conditions. If the climate zones will continue to move northward in the Nordic countries, it will increase the potential for continued establishment and spread of dollar spot. / SAMMANFATTNING Dollar spot är en svampsjukdom som drabbar gräs och som orsakas av svampen Sclerotinia homoeocarpa. Under 2013 upptäcktes dollar spot för första gången i Norden. Dollar spot är en mycket allvarlig grässjukdom i USA och man spenderar massor med pengar för att bekämpa svampen. I denna uppsats har sjukdomsutvecklingen av dollar spot, från fyra geografiskt skilda isolat, undersökts vid olika temperaturer; 6 °C, 15 °C och 21°C. Detta för att hitta den lägsta tillväxttemperaturen hos svampen som orsakar sjukdomen och även för att upptäcka eventuell skillnad mellan de olika isolatens sjukdomsutveckling i gräs. Isolaten som använts i experimenten kom ifrån Danmark, Norge och Sverige. Gräsproverna som svampen S. homoeocarpa odlades på kom ifrån två golfbanor, från Uppsala respektive Gävle. Krukor med gräs inokulerades med S. homoeocarpa och dessa krukor placerades i klimatskåp som höll olika temperatur. Vid tre tidpunkter (dag 7, 14 och 21) lästes den infekterade gräsarean av. Efter att alla resultat hade sammanställts visade det sig att dollar spot hade den snabbaste och mest aggressiva sjukdomsutvecklingen vid 6 °C. Det fanns även skillnader i sjukdomsutveckling av dollar spot mellan de fyra isolaten vid olika temperaturer. Det fanns en viss koppling mellan geografisk härkomst och optimumtemperatur för sjukdomsutveckling hos isolaten, vilket kan tyda på att de kan ha anpassat sig till den omgivning som de etablerat sig i. Med de låga tillväxttemperaturer som svampen S. homoeocarpa klarar för infektion och etablering i grönytor är det mycket troligt att sjukdomen dollar spot fått fäste i Norden, och kommit för att stanna. Med de klimatförändringar som sker, dvs. ökade temperaturer och ökad nederbörd, som i sin tur medför förhöjd luftfuktighet, kommer sjukdomen att kunna breda ut sig ännu mer, eftersom svampen trivs vid hög luftfuktighet. Flyttas klimatzonerna högre upp i Norden kommer det att bidra till att utbredningen av dollar spot ökar.

Paper presented before the Second Pan American Scientific Congress, Washington, U.S.A., December 27, 1915-Janunary 8, 1916.

La ppGpp et la pppGpp, qui sont synthétisées/hydrolysées par les RelA/Spot homologs (RSH), jouent un rôle centrale dans l’adaptation des bactéries contre la privation des nutriments et les stress environnementaux. Les enzymes RSH et ppGpp ont été découverts dans le chloroplaste. Il a été récemment démontré que ppGpp joue un rôle comme répresseur globale de l’expression de gènes chloroplastiques. Certains stresses environnementaux et hormones induisent l’accumulation de ppGpp chez les plantes, cependant le mécanisme moléculaire n’est pas encore connu. Ici nous nous sommes intéressés à découvrir les facteurs qui interagissent avec les RSH, et qui donc sont susceptible de réguler le métabolisme du ppGpp. En utilisant un crible double-hybridation de levure nous avons identifiées des proteines qui interagissent avec les RSH y compris l’acyl carrier protein (ACP) et des GTPases associées au ribosome. ACP et RSH1 semblent être indispensables pour l’accumulation de ppGpp induite par la carence de la biosynthèse des acides gras, tandis que le ppGpp et un GTPase associé au ribosome contribuent à la résistance contre le heat-shock. Nous avons aussi effectué du co-immunoprécipitation spectrométrie de masse avec RSH1. Plusieurs protéines ont été identifiées y compris des protéines associées au nucléoid et des protéines liées à la signalisation chloroplastique, indiquant que RSH1 pourrait etre impliqué dans la machinerie de transcription chloroplastique. Nos résultats montrent que chez les plantes le ppGpp joue un rôle non seulement comme chez les bacteriés mais aussi participe à de nombreux processus biologiques qui sont spécifiques aux plantes. / Guanosine tetra-phosphate and penta-phosphate (ppGpp and pppGpp), which are synthesized/hydrolyzed by RelA/Spot homolog (RSH) enzymes, play a central role in the adaptation of bacteria to nutrient limitation or other stresses. Both RSH enzymes and ppGpp are present in the chloroplasts of plants. Recent studies have shown that ppGpp acts as a global repressor of chloroplast gene expression. Certain environmental stresses and hormones induce ppGpp accumulation in chloroplasts, however the molecular mechanisms underlying the activation of ppGpp signalling in response to such stimuli is essentially unknown. We searched for factors that interact with RSH enzymes and so could play a role in activating ppGpp signalling. Using a targeted yeast two hybrid screen several proteins were identified that interact with RSH enzymes including acyl carrier protein (ACP) and ribosome associated GTPases. ACP and RSH1 appear to be required for ppGpp induction in response to fatty acid biosynthesis depletion, while ppGpp and an RSH-interacting GTPase contribute to the resistance of plants to heat shock. We also performed non-targeted co-immunoprecipitation mass spectrometry (CoIP-MS) of RSH1. New RSH interaction candidates were identified, including plastid nucleoid associated proteins and chloroplast signalling proteins, suggesting that RSH1 may be associated with the plastid transcription machinery. Our results give new insights into ppGpp signalling, and show that some elements are conserved between plants and bacteria, while others are implicated in plant-specific biological processes.

L’indice CAC40 est la première chose à laquelle on pense lorsqu’on parle de bourse en France. Cependant il n’est pas négociable. C’est pourquoi sont apparus des contrats dérivés comme le contrat future FCE dont le sous-jacent est le CAC40 qui peuvent être achetés et vendus. Leurs valeurs sont très proches mais non égales. Quel est donc la relation qui lie le contrat FCE au CAC40 ? A l’aide de données téléchargeables quotidiennement sur Internet et accessibles à tous une réponse va être apportée. Dans une première partie nous présentons le contrat à terme dérivé du CAC40, les raisons de le « trader » et le comparons aux autres contrats future dérivés d’indices boursiers dans le monde. Nous étudions ensuite la relation FCE/CAC40 en terme d’efficience informationnelle. Pour cela nous allons étudier différentes notions de base et tenter de les modéliser. Enfin dans une dernière partie nous nous intéressons à cette même relation d’un point de vue microstructure, en étudiant en particulier des variables non prix (volume et position ouverte), et la volatilité. Nous allons enfin tenter d’apporter une modélisation de la volatilité en fonction de ces variables. / The CAC 40 index is the first thing that comes to mind when talking about financial markets. However it is not negotiable. Therefore appeared derivative contracts such as futures contract FCE whose underlying is the CAC40 index which can be bought and sold. Their values are very close but not equal. So what is the relationship between the FCE contract and the CAC40? Using daily downloadable data on the Internet and accessible to everyone, answers will be given. In the first part we present the future contracts derived from the CAC40, the reasons to trade it, and we compare it to other stock index futures in the world. We then study the relationship FCE / CAC40 in terms of informational efficiency. For that we will study different notions of basis and try to model them. Finally in the last part we are interested in the same relationship but with a microstructure point of view, studying in particular non-price variables: volume and open interest, and volatility. Finally, we will try to modelise volatility with these variables.

The diploma paper is concerned with the occurrence of ethic issues in advertising. The aim of the paper is to find out whether morality or immorality of the adverting is perceived. After all, the advertising has become a part of our lives. It appeals to our senses and influences human behaviour. Thus, the advertising needs to be monitored. It may seem that the advertising is a category on its own. There are no restrictions applied in the advertising. Every advertising agency has an opportunity to create any kind of advertising. However, this is not true. Some efforts are made through the Council for Radio and Television Broadcasting and the Council for Advertising. Moreover, the Code of Advertising Practice was created and it should ensure the morality of the advertising in the Czech Republic. The morality, nevertheless, cannot be guaranteed so easily. Ethics is a broad term which can have different meanings for anyone.

Orientador: João Antonio da Costa Andrade / Resumo: O milho é uma das culturas mais extensamente cultivadas em todo mundo. A incidência e a severidade de doenças têm aumentado significativamente nos últimos anos acarretando perdas no rendimento e afetando a qualidade dos grãos. Muitos trabalhos têm sido desenvolvidos na tentativa de identificar híbridos resistentes às principais doenças que acometem a cultura do milho, mas poucos são os relatos de estudos com linhagens. Dessa forma, o objetivo deste estudo foi: 1) identificar linhagens resistentes e susceptíveis com base na área abaixo da curva de progresso de doenças (AACPD) para os sintomas de ferrugem tropical (TR), ferrugem polissora (SR), cercosporiose (GLS), helmintosporiose (NLB), mancha marrom (PBS) e mancha branca (PLS); 2) identificar linhagens resistentes e suscetíveis com base nos parâmetros de adaptabilidade e estabilidade fenotípica para os sintomas de cercosporiose, helmintosporiose, mancha marrom e mancha branca; 3) identificar as melhores datas de semeadura, com a maior ocorrência das doenças, para fins de avaliação de linhagens e outros genótipos para resistência. Cinquenta linhagens, derivadas de populações com grãos flint e dent, foram avaliadas em blocos casualizados com três repetições, aos 45, 60, 75 e 90 dias após a semeadura em duas épocas, para medição da AACPD. Para a análise de adaptabilidade e estabilidade, 41 linhagens foram avaliadas em blocos casualizados com três repetições, 30 dias após o florescimento feminino, em onze épocas de semeadura, us... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

>Magister Scientiae - MSc / An accurate prediction of pore pressure is an essential in reducing the risk involved in a well or field life cycle. This has formed an integral part of routine work for exploration, development and exploitation team in the oil and gas industries. Several factors such as sediment compaction, overburden, lithology characteristic, hydrocarbon pressure and capillary entry pressure contribute significantly to the cause of overpressure. Hence, understanding the dynamics associated with the above factors will certainly reduce the risk involved in drilling and production. This study examined three deep water drilled wells GA-W1, GA-N1, and GA-AA1 of lower cretaceous Hauterivian to early Aptian age between 112 to 117.5 (MA) Southern Pletmos sub-basin, Bredasdorp basin offshore South Africa. The study aimed to determine the pore pressure prediction of the reservoir formation of the wells. Eaton’s resistivity and Sonic method are adopted using depth dependent normal compaction trendline (NCT) has been carried out for this study. The variation of the overburden gradient (OBG), the Effective stress, Fracture gradient (FG), Fracture pressure (FP), Pore pressure gradient (PPG) and the predicted pore pressure (PPP) have been studied for the selected wells. The overburden changes slightly as follow: 2.09g/cm3, 2.23g/cm3 and 2.24g/cm3 across the selected intervals depth of wells. The predicted pore pressure calculated for the intervals depth of selected wells GA-W1, GA-N1 and GA-AA1 also varies slightly down the depths as follow: 3,405 psi, 4,110 psi, 5,062 psi respectively. The overpressure zone and normal pressure zone were encountered in well GA-W1, while a normal pressure zone was experienced in both well GA-N1 and GA-AA1. In addition, the direct hydrocarbon indicator (DHI) was carried out by method of post-stack amplitude analysis seismic reflectors surface which was used to determine the hydrocarbon prospect zone of the wells from the seismic section. It majorly indicate the zones of thick hydrocarbon sand from the amplitude extraction grid map horizon reflectors at 13AT1 & 8AT1 and 8AT1 & 1AT1 of the well GA-W1, GA-N1 and GA-AA1 respectively. These are suggested to be the hydrocarbon prospect locations (wet-gas to Oil prone source) on the seismic section with fault trending along the horizons. No bright spot, flat spot and dim spot was observed except for some related pitfalls anomalies

No description available.