During the work of this research project we were interested in mathematical techniques that give us an insight to the following questions: How do we understand the trading decisions made by a manager of a hedge fund and what influences these decisions? In what way does an illiquid market affect these decisions and the performance of the fund? And how does the payment scheme affect the investor's decisions? Based on existing work on hedge fund management, we start with a fund that can be modelled with one risky investment and one riskless investment. Next, subject to the hedge fund special reward scheme we maximise the expected utility of wealth of the manager, by controlling the percentage invested in the risky investment, namely the portfolio. We use stochastic control techniques to derive a partial differential equation (PDE) and numerically obtain its corresponding viscosity solution, which provides a weak notion of solutions to these PDEs. This is then taken to a liquidity constrained scenario, to compare the behaviour of the two scenarios. Using the same approach as before we notice that due to the liquidity restriction we cannot use a simple model to combine the risky and riskless investments as a total amount, and hence the PDE is one order higher than before. We then model an investor who is investing in the hedge fund subject to the manager's optimal portfolio decisions, with similar mathematical tools as before. Comparisons between the investor's expected utility of wealth and the utility of having the money invested in the risk-free investment suggests that, in some cases, the investor is paying more to the manager than the return he is receiving for having invested in the hedge fund, compared to a risk-free investment. For that reason we propose a strategic game where the manager's action is to allocate the money between the two assets and the investor's action is to add money to the fund when he expects profit. The result is that the investor profits from the option to reinvest in the fund, although in some extreme cases the actions of the manager make the investor receive a negative value for having the option.

The Cape Verde archipelago is located 2000 km east of the Atlantic oceanic ridge and 500 km west of the western part of Africa. The plateau of the archipelago rises on average 2 km above the seafloor, which makes it one of the highest oceanic plateaus on Earth. Cape Verde originates from hotspot formation, a geological phenomenon which takes place beyond the tectonic plate boundaries where magma rises to the surface. In this thesis, volcanic material taken from the Charles Darwin volcanic field at a depth of more than 3000 meter and made up by four basaltic rocks and one agglomerate will be investigated. The agglomerate and vesicles in the rock shows that explosive volcanism occurs in high water depths, which is generally not common. Therefore, the material will be investigated to find out how explosive volcanism can occur at high water depths. The investigation will be based on quantifying the number of vesicles to able to calculate their area and analyze the magmatic water content in clinopyroxene crystals taken from the agglomerate by FTIR spectroscopy. Water is a volatile substance in the composition of magma and has a huge effect on its behavior at eruption. The results of quantification show that the area taken by vesicles varies from 7- 54 % which shows that magmatic products with high number of vesicles are common. The FTIR analysis shows that the magmatic water content can be high enough to cause an oversaturated magma system, which creates explosive eruptions. This statement is based on only one clinopyroxene crystal that had a magmatic water content of 3,87 ± 0,77 %. Other possible reasons for explosive eruptions at high water depth are the CO2 content in the magma and the size of volcanic vent. / Kap Verde är en arkipelag, situerad cirka 2000 km öster om den mittatlantiska spridningsryggen och 500 km väster om det afrikanska fastlandet. Arkipelagens platå har en genomsnittlig höjd på 2 km, vilket gör den till en av världens högsta oceaniska platåer. Arkipelagen har uppkommit av hetfläcksbildning, ett geologiskt fenomen baserad på att magma erupteras till ytan där jordskorpan är förtunnad och inte har någon anknytning till de tektoniska plattgränserna. Det som undersöks i detta kandidatarbete är vulkaniskt material, taget från den vulkaniska undervattensön Charles Darwin vulkanfält som ligger i den västra del Kap Verdes norra ö-grupp på över 3000 meterdjup. Materialet består av ett agglomerat och fyra stenstuffer av basaltisk komposition. Agglomeratet tyder på att explosiva vulkanutbrott förekommer, vilket även bekräftas av stenstufferna som har rikligt förekomst av luftbubblor. Explosiva vulkanutbrott är generellt inte förekomliga vid höga vattendjup, därav undersöks materialet för att kunna reda ut orsakerna som ger upphov till förekomsten av explosiva vulkanutbrott. Undersökningen baseras på att kvantifiera luftbubblor hos stenstufferna för att kunna räkna ut arean som upptas och analysera vattenhalten i klinopyroxenkristaller i agglomeratet med hjälp av FTIR spektroskopi. Vatten tillhör de flyktiga beståndsdelar i magmas sammansättning som kallas för volatiler och utgör en viktig parameter för magmans uppträdande vid eruption. Resultatet kvantifiering av luftbubblor visar att arean som upptas av luftbubblor varierar mellan 7–54 % av stenstufferna total area, vilket understryker att magmatiska produkter med hög andel luftbubblor är förkomliga. FTIR analysen visar att det finns tillräckliga höga vattenhalter för ett övermättat magmasystem som ger upphov till vulkanutbrott med explosiva förlopp, baserat på vattenhalten 3,87 ± 0,77 % av en klinopyroxenkristall. Andra möjliga orsaker till uppkomsten av magmatiska produkter med hög andel luftbubblor är koldioxidhalten i magman och storleken på vulkanrören.

Full protection from forces of nature can not be achieved. A residual risk will always remain. Compromises must be found between the expectations and demands on flood protection on the one hand and the technical, economical and ecological possibilities on the other. The calls for full flood protection by victims of the Weißeritz flood in 2002 and by some politicians can not be satisfied. However, the valid design criterias concerning the upgrading of the Weißeritz regarding flood protection do not meet the requirements. A more sophisticated approach by the Saxonian Dam Authority and the City of Dresden led to much greater design discharge values. Therefore the Institute for Hydraulic Engineering and Applied Hydromechanics of TU Dresden developed physical and numerical models which will function as assisting tools during the decision process for the planned flood measures. / Der Schutz vor Naturgewalten ist kein vollständiger Schutz, ein Restrisiko bleibt immer. Hier sind Kompromisse erforderlich, Kompromisse zwischen den Erwartungen und Forderungen an den Hochwasserschutz und den technischen, ökonomischen und ökologischen Möglichkeiten. Die Forderungen vom Hochwasser betroffener Bürger sowie einiger Dresdner Politiker, sich vollständig vor Hochwasser an der Weißeritz zu schützen, sind nicht realisierbar. Andererseits sind Bemessungsgrößen nach derzeit geltenden Regeln für den Ausbau der Weißeritz nicht zeitgemäß. Eine differenziertere Betrachtungsweise für Dresden führte in den Verhandlungen zwischen der sächsischen Landestalsperrenverwaltung und der Stadt zu einem weit höheren Bemessungsabfluss. Die Hochwassermodelle am Institut für Wasserbau und Technische Hydromechanik der TU Dresden haben diesen Prozess unterstützt.

In Louisiana, the beds of natural lakes are owned by the state. The locations of property boundary lines separating state property from private lands have usually been set by determining the levels of natural monuments known as ordinary high water marks. The term is confusing and subjective, leading to controversy in reference to its determination. Catahoula Lake in central Louisiana was chosen as a study site because of its large size, its 20-foot variation in water levels, and its low-relief perimeter. Geology, geomorphology, hydrology, archaeology, vegetation, dendrochronology and dendrohydrology of the ancient cypress fringe, nineteenth century land survey records, historical records, and time-series statistics were applied to determine the elevation range of ordinary high water. Research suggests that the level of the ordinary high water natural monument used universally in Louisiana to define lake boundaries is not the correct natural monument. This research suggests that, for example, the natural monument that defines the Catahoula Lake boundary is not a vertical monument, but rather an areal monument that was originally recognized by nineteenth century U.S. government surveyors and embedded in the evidence extracted from their original field notes. The solution coincides with the boundaries of regional land patents and offers a consistent solution to determining the boundaries of thousands of acres of disputed lands. The procedure is applicable to other lake and swamp boundaries in Louisiana and other states.

Reproductive containment in farmed fish is highly desired for sustainable aquaculture to prevent genetic introgression with wild conspecifics and enhance productivity by suppressing sexual maturation. A number of strategies have already been implemented or have been tested in commercially important fish (e.g. triploidy, monosexing, hormonal therapies); however, they either do not result in 100% containment, or they cannot be applied to all species. One promising new approach consists in disrupting primordial germ cells (PGCs), at the origin of germline cells, to induce sterility. The work carried out in this doctoral thesis aimed to investigate the genes involved in the survival of germ cells and subsequently conduct a functional analysis of candidate genes using CRISPR/Cas9 gene editing system to ultimately provide the basis for the development of a novel sterilisation technique. Nile tilapia was chosen as the experimental animal as it is a major aquaculture species worldwide and the control of reproduction plays a critical role in the farming productivity in this species. In addition, the species has clear advantages as its whole genome sequence is accessible, the generation time is relatively short and zygotes can be available all year round. Initially, a panel of 11 candidate genes with reported roles in survival of PGCs was investigated during the ontogenic development which led to the selection of piwi-like (piwil) gene as a target for genome editing. Then, high temperature was tested as a means to induce germ cell loss to better understand the mechanism underlying germ cell survival and apoptosis, and this study confirmed the functional importance of piwil genes in relation to germ cell loss and proliferation. In addition, the study suggested potential subfunctionalisation within the Bcl-2 gene family which requires further investigation. The next step aimed to optimise the CRISPR/Cas9 gene editing method by improving the microinjection system and testing different concentrations of sgRNAs. Over 95% of injected embryos showed on-target mutation in piwil2 via zygote injection of CRISPR/Cas9 reagents and complete KO larvae were shown in half of the mutants, producing putative sterile fish. However, there was no clear association between the phenotypes in PGCs and the mutation rate. Further comparative studies of mutant screening methods including T7E1, RGEN, HRMA, fragment analysis and NGS revealed that the genotypes of F0 are highly mosaic, suggesting that deep sequencing is recommended for accurate and high throughput F0 screening and further improvement for predictable genome editing is required for a reliable gene functional analysis in F0. In summary, the current thesis provided new scientific knowledge and supporting evidence for the use of the CRISPR/Cas9 gene editing platform to study gene function associated with sterility, with the ultimate goal to develop an alternative sterilisation method in fish.

Den hegemoniska maskuliniteten är försatt i ett stadie av konstant förändring och omförhandling. Saker som i en viss tidsepok kommit att associeras med femininitet kan vid en annan tidpunkt komma att tillskrivas som ett maskulint attribut. Då mannens relation till sig själv  – och hans relation till sin omgivning – påverkas av den maskulina idealbild som förmedlas, i bland annat populärkulturellt material, blir det därför viktigt att undersöka hur denna hegemoniska maskulinitet yttrar sig i olika tidsepoker. Detta dels för att utröna varför den ser ut som den gör idag och hur den porträtterats historiskt, men även för att förutspå hur gestaltningen av maskulinitet kan komma att förändra sig i framtiden. Denna studie har utfört en komparation mellan westernfilmer som av diverse forskare och kritiker ses som typiska tidsenliga exempel på filmer inom westerngenren. Detta gjordes för att fastställa hur den historiska porträtteringen av den hegemoniska maskuliniteten skiljer sig från den i ett modernt populärkulturellt material inom samma genre. Detta gjordes genom att utföra en semiotisk bildanalys av protagonistens och antagonistens slut- samt introduktionsscen, därefter jämfördes de observationer som gjorts i analysen, varpå övergripande analyser gjordes, i vilken återkommande drag, behandlingen av minoriteter, kroppsattribut och miljöerna som dessa befann sig i och bebodde, diskuterades och sammanställdes. Kontentan av resultatet var att attribut som tidigare associerats med protagonister i materialet från 1950-talet numera utgjordes av antagonisterna i materialet från 2010-talet. Den tidigare maskuliniteten som gestaltades av storväxthet och breda axlar har förändrats, och den hegemoniska maskuliniteten har nu gett upphov till en man med mer komplexa motivationer, större känsloliv och hänsynsfullhet än den som skänktes av protagonisten i dom tidigare gestaltningarna. Genom att uppnå sina målsättningar kunde även protagonisterna i materialen från båda tidsperioderna dölja att dessa antagit attribut som tidigare varit kvinnligt kodade i den nya maskulina idealbilden, exempelvis fällandet av tårar.

Made available in DSpace on 2014-07-29T15:07:50Z (GMT). No. of bitstreams: 1 Dissertacao JanainaGomes.pdf: 323977 bytes, checksum: 872ea1e01b711a691d7746d206ac395e (MD5) Previous issue date: 2008-08-20 / The present research was carried out at Sector of Fish of the Goiás Federal University, between December the 2006 and May the 2007, which lasted for 127 days. Nile tilapia juveniles (Oreochromis niloticus), Supreme strain, with starter weight of 31.86 ± 1.75 g were randomly allotted in 32 tanks of 100 L of capacity each one in raceway system. The full water exchange of the tanks occurred in 30 min at the beginning. The fish were fed with extruded diet containing 36% of CP in pellets of 2-4 mm in diameter. By the average weight of 100 g, the fish were fed with extruded diet with 32% of CP in pellets of 4-6 mm in diameter until the end of the experiment. This assessment was performed to evaluate feed frequencies (2, 3, 4 and 5 times/day) and ratio (ad libitum and based on the percentage of the biomass weight - %PVBIO) on the productive performance, chemical composition, biometric indices, carcass and fillet yield and costs and profitability partial of Nile tilapia during the weight gain in the raceway system. The experimental design was composed by a completely randomized design in a factorial (4 x 2), with four repetitions, totalizing 32 experimental units. The performances body weight (BW), weight gain (WG), final biomass (FB), feed intake (FI), index of food intake (IF), apparent feed conversion ratio (AFCR), feed efficiency (FE), survival (S%), protein efficiency ratio (PER), specific growth ratio (SGR) and uniformity of the lot (U%) -; fillet weight (FW), carcass yield (CY), fillet yield(FY), biometric indices, and chemical composition fillet (total dry matter (TDM), moisture (MO), crude protein (CP), crude lipid (CL), ash) were the main evaluated parameters. The performance data were submitted to the analysis of variance and Duncan tests (5%), and the others to Tukey test (5%). Despite the quantity of food provided in the treatments, the main variables of water quality remained within the limit recommended for fish breeding. Better AFCR, FE and PER were reached for fish fed three times a day and greater PVBIO% for those ones fed twice daily ad libitum (P <0.05). The values of FBW, FL, FWG, FB, and FI were higher for fish fed four times a day (P <0.05), with the AFCR and PER values similar to those in fish fed three times a day. S%, SGR, CF and U% suffered no influence by the feeding frequency (P> 0.05). Only in IF differences on how to supply the ration (P <0.05) were observed. Fish fed four, five and three times a day had better average of FY, differing from those fed twice a day (P<0.05). The feeding frequency of less than five times had greater CY and VFI, but it did not differ from the other regimens. Difference in form of supply was observed only for RF, and the best average was reached in fish fed ad libitum. Regarding the chemical composition fillet, no differences in ashes were observed (P>0.05). The highest level of CL was found in three times of feeding frequency, which was statistical relevant (P<0.05) in comparison to the others. Interaction was observed for the variables TDM, MO and CP. The cost incidence (CI) was lower in three times a day of feeding frequency with feed supply based on %BW. The feeding frequency of 3 times per day ad libitum presented the best result concerning performance, and suggested lower cost with labor for juveniles of Nile tilapia cultivated in raceway tanks. / A pesquisa foi realizada no Setor de Piscicultura da Escola de Veterinária da Universidade Federal de Goiás, no período de dezembro de 2006 a maio de 2007, com duração de 127 dias. Foram utilizados juvenis de tilápia do Nilo (Oreochromis niloticus), linhagem Supreme, com peso médio inicial de 31,86 ± 1,75 g, distribuídos aleatoriamente em 32 caixas reguladas para 100 L adaptadas ao sistema raceway. A troca total de água das caixas, no início, ocorreu em 30min. Os peixes foram alimentados com ração extrusada contendo 36% de PB e grânulos com 2 a 4 mm de diâmetro até o peso médio aproximado de 100 g; em seguida, foram alimentados com ração extrusada 32% de PB com grânulos de 4 a 6 mm de diâmetro até o final do experimento. Objetivou-se determinar o efeito das frequências (2, 3, 4 e 5 vezes/dia) e formas de fornecimento da ração (à vontade e com base na porcentagem do peso da biomassa) sobre o desempenho produtivo, a composição bromatológica do filé, os índices biométricos, os rendimentos de carcaça e filé, e custos e rentabilidade parciais da tilápia durante a fase de engorda no sistema raceway, constituindo, assim, um delineamento inteiramente casualizado em esquema fatorial (4 x 2), com quatro repetições, totalizando 32 unidades experimentais. Foram assim avaliados: desempenho produtivo - peso (P), ganho de peso (GP), biomassa final (BF), consumo de ração (CR), índice de consumo alimentar (IA), conversão alimentar aparente (CAA), taxa de eficiência alimentar (TEA), taxa de eficiência protéica (TEP), taxa de crescimento específico (TCE), sobrevivência (S%), uniformidade do lote (U%) -; peso do filé (PF), rendimentos de carcaça (RC) e filé (RF), índice hepatosomático (IHS), índice gordura víscero-somático (IGVS) e composição bromatológica do filé (matéria seca total (MST), umidade (UM), proteína bruta (PB), extrato etéreo (EE), cinzas). Os dados de desempenho produtivo foram submetidos à análise de variância e teste Duncan (5%), e os demais ao teste Tukey (5%). Apesar da quantidade de alimento fornecido por tratamento, as principais variáveis de qualidade da água permaneceram dentro do limite recomendável para os peixes. Os valores de P, GP, BF, e CR foram maiores para os peixes arraçoados quatro, três e cinco vezes ao dia, respectivamente, diferindo de duas vezes ao dia (P<0,05). Foi observada interação significativa para IA, CAA, TEA e TEP. Observou-se melhor CAA, TEA e TEP para os peixes arraçoados três vezes ao dia pela %PVBIO e duas vezes ao dia à vontade (P<0,05). S%, TCE e U% não sofreram influência quanto à frequência alimentar (P>0,05). Os peixes arraçoados três, quatro e cinco vezes ao dia apresentaram melhor média de RF diferindo dos peixes arraçoados duas vezes (P<0,05). A frequência de cinco vezes apresentou menor RC e maior IGVS, porém não diferiu das demais. Foi observada diferença para forma de fornecimento apenas para RF, sendo a melhor média para os peixes arraçoados à vontade. Quanto à composição bromatológica, só não foram observadas diferenças (P>0,05) para Cinzas. O maior teor de EE foi encontrado na frequência de três vezes (P<0,05) diferindo das demais. Foi observada interação (P<0,05) para as variáveis MST, UM e PB. Quanto à avaliação econômica, a incidência de custo (IC) foi menor na frequência de três vezes ao dia com fornecimento de ração baseado na %PVBIO. Recomenda-se a frequência alimentar de 3 vezes/dia para juvenis de tilápia do Nilo até o abate por possibilitar menor gasto com mão de obra, melhores resultados para desempenho, com fornecimento de ração à vontade, até atingirem a saciedade aparente, quando cultivados em tanques raceways