This dissertation seeks to demonstrate Lucan's profound engagement and conflict with two ancient intellectual and literary traditions that can both be regarded as escapist, that is, as promising or postulating a sanctuary (whether physical or spiritual) from the world's troubles, and that were both active in Lucan's own day: utopian writing about science, exemplified in Latin by Lucan's uncle Seneca the Younger, as well as by the astronomical poet Manilius, and utopian Egyptology, as reflected in a wide variety of texts ranging from Herodotus, through Diodorus Siculus, to Lucan's contemporary, the Alexandrian polymath Chaeremon. To this end, I have examined two closely related sequences in the De Bello Civili that have received little attention from scholars of Lucan, namely Pompey's journey to Egypt in Book Eight and Caesar's Egyptian sojourn in Book Ten, during which Lucan's two main characters are each shown attempting to take refuge from the poem's ubiquitous violence through the double avenue of travel to Egypt (to which the defeated Pompey flees, and where his pursuer Caesar hopes to leave the civil war behind) and the practice of natural science (with Pompey's astronomical inquiry and Caesar's investigation of the Nile). In this context, I have also considered Cato's Libyan adventures, from the intervening Book Nine. Both Pompey and Caesar discover that escape through either method is impossible, for the fabled Egyptian Shangri-La is now embroiled in the political, social, and economic crisis of the outside world, while not only the natural universe but even the very act of inquiry into nature are alike contaminated by the ethos of civil war. The virtuous Cato, on the other hand, does not even make the attempt, maintaining a single-minded focus on his civic duties. By revealing such escape to be both immoral (through Cato's example) and impossible (through the examples of Pompey and Caesar), Lucan signals his decisive rejection of the escapist predilections of many of his contemporaries (including his uncle Seneca and his own father Annaeus Mela), who tried to distance themselves from the vicissitudes of political life under the later Julio-Claudians through retirement into a state of philosophical otium.

This dissertation seeks to demonstrate Lucan's profound engagement and conflict with two ancient intellectual and literary traditions that can both be regarded as escapist, that is, as promising or postulating a sanctuary (whether physical or spiritual) from the world's troubles, and that were both active in Lucan's own day: utopian writing about science, exemplified in Latin by Lucan's uncle Seneca the Younger, as well as by the astronomical poet Manilius, and utopian Egyptology, as reflected in a wide variety of texts ranging from Herodotus, through Diodorus Siculus, to Lucan's contemporary, the Alexandrian polymath Chaeremon. To this end, I have examined two closely related sequences in the De Bello Civili that have received little attention from scholars of Lucan, namely Pompey's journey to Egypt in Book Eight and Caesar's Egyptian sojourn in Book Ten, during which Lucan's two main characters are each shown attempting to take refuge from the poem's ubiquitous violence through the double avenue of travel to Egypt (to which the defeated Pompey flees, and where his pursuer Caesar hopes to leave the civil war behind) and the practice of natural science (with Pompey's astronomical inquiry and Caesar's investigation of the Nile). In this context, I have also considered Cato's Libyan adventures, from the intervening Book Nine. Both Pompey and Caesar discover that escape through either method is impossible, for the fabled Egyptian Shangri-La is now embroiled in the political, social, and economic crisis of the outside world, while not only the natural universe but even the very act of inquiry into nature are alike contaminated by the ethos of civil war. The virtuous Cato, on the other hand, does not even make the attempt, maintaining a single-minded focus on his civic duties. By revealing such escape to be both immoral (through Cato's example) and impossible (through the examples of Pompey and Caesar), Lucan signals his decisive rejection of the escapist predilections of many of his contemporaries (including his uncle Seneca and his own father Annaeus Mela), who tried to distance themselves from the vicissitudes of political life under the later Julio-Claudians through retirement into a state of philosophical otium.

Regulation of rivers by dams and reservoirs is a good example where anthropogenic impact could be considerable both in the local environment, but also has major implications upstream and downstream. This study was accomplished as a literature study of the river Nile, which is extremely important for water supply. The purpose of this study was to investigate the consequences of the construction of the Aswan High Dam, to obtain a consistent flow for water supply, irrigation and power generation in Egypt. Since Egypt has a very hot and dry climate large amounts of water in reservoir is lost to the Nubian aquifer system and by evaporation. The consequences from constructing the dam are considerable. It has led to the preventing of the annual flooding and a significant reduction in sediment load reaching the outer delta, which has led to an erosion of the delta front. The incoming waves create a current, mainly towards the east, carrying away the eroded material. In order to protect the delta front seawalls and breakwaters has been built. They have stopped the erosion of the areas behind them, but it has also led to the erosion of other areas. The issues in Egypt reflect the global crisis, mainly in delta areas, which prevail in regulated rivers. The biggest issue globally is the reduced sediment transport to the coast that causes land loss.

On the Blue Nile in Sudan, near the Ethiopian border, there is a measurement station named El Deim. The discharge assessments carried out at this station are crucial for the water resource management in Sudan. Due to changed conditions, caused by a heightening of the downstream-located Roseires dam, new methods for discharge assessment are needed. The objective of the present study was to examine possibilities and methodologies to assess the discharge at this station. The flow dynamics was examined through steady state as well as dynamic hydraulic modeling by use of the Mike 11 modeling software package. By simulating possible future scenarios, in the aspect of discharge variations in the Blue Nile and water level variations in the reservoir, the effects from the raised dam on El Deim could be studied. The model was based on bathymetrical data in form of cross sections. As boundary conditions for the simulation, measured and synthetic data series of discharge and water levels were used. The known measured water levels at El Deim were compared with the simulated water levels at El Deim for the same discharge scenarios. The modeled value corresponds well to the measured values. The existing discrepancies between the simulated and measured values are likely caused by insufficient bathymetrical data.   Simulation results show that the flow dynamics at El Deim are highly dependent on the water level of the reservoir and the discharge’s rate of variation. Accordingly, rating curves were created for a range of water levels at the reservoir. With the use of these curves, and tables/equations based on them, the discharge can be rated by knowing the water level at the Roseires dam and El Deim. However, the results from this study are more a description of the principles of how the discharge ratings could be performed. If the methodology and rating tools from this study are planned to be implemented the model must be improved with more bathymetrical data. The improvements are needed to create more accurate curves, tables and equations for discharge rating. Discharge ratings can then be produced and enable better operation of Roseires dam and a more efficient use of the valuable water resources in Sudan. In order to test the applicability of the created model and produced rating tools they should be compared with new measurement data from El Deim with the heightened Roseires dam fully implemented.   It is possible to assess the discharge at El Deim even when backwater effects affect the station. The methodology developed in this thesis would be applicable for similar studies at other locations.

No description available.

Various aspects of the ascorbic acid (vitamin C) nutrition of Oreochromis niloticus and O. mossambicus are considered in this treatise. The activity of L-gulono-Y-lactone oxidase was assessed in liver and kidney of 14 teleosts of 3 genera, histochemically (qualitatively) and biochemically (quantitatively). Activity of this enzyme was only detected in liver and kidney of common carp, Cyprinus carpio, and kidney of O. spilurus and O. aureus. No activity was detected in the species considered herein. The quantitative dietary ascorbic acid requirements of juvenile O. niloticus and O. mossambicus were determined by feeding diets containing graded levels of the vitamin (O~400mg/lOOg) and were based on growth response, food utilization, gross body composition data, tissue and biochemical changes and ability to prevent signs of ascorbic acid deficiency. The recommended level of supplementation of dietary ascorbic acid is l2Smg/lOOg and the net requirement 42mg/lOOg diet. Long-term ascorbic acid deprivation in £. niloticus and O. mossambicus resulted in poor performance in terms of growth, food utilization and survival. Other parameters evaluated included hepatosomatic index, liver and muscle glycogen content, blood parameters, tissue ascorbate concentrations, collagen contents, hydroxyproline and proline contents, and serum transaminase and cholesterol levels. Signs of ascorbic acid deficiency were severe and included haemorrhage~ opercular deformity, tail erosion, exophthalmia, cataract and spinal deformity (lordosis and scoliosis). Histologically scorbutic fish showed evidence of generalized bone changes associated with excessive production of chondrocytes and failur~ of ossification of growing bone areas. Eye lesions were associated with scleral collapse and also observed was hyperplasia of gill secondary lamellae epithelial cells and pronounced steatitis. Tissue ascorbate concentrations were correlated with dietary ascorbic acid levels and both species exhibited highest concentrations in the ovary, brain and testis, followed by heart, liver, gut, gills, eyes and the lowest levels in muscle and gall-bladder. The physiological role for ascorbic acid in each tissue is discussed. Eight week growth studies were conducted to evaluate the utilization of L-ascorbic acid (AA), the sodium salt of L-ascorbic acid (NaAA), glyceride coated L-ascorbic acid (GCAA), the barium salt of L-ascorbic acid 2-sulphate (AA2S) and ascorbyl palmitate CAP) in diets for O. niloticus and O. mossambicus, All five forms were added to the basal diet, containing no ascorbic acid CAAF), on an equimolar basis to supply 12Smg ascorbic acid/IOOg diet. All forms performed well in terms of growth, food utilization, and prevented signs of deficiency, Retention of ascorbic acid in diets after processing was increased by increasing dietary ascorbic acid level. AA2S and GCAA were more stable than AA and NaAA during processing and storage. The stability of AA, NaAA, GCAA and AA2S under different storage conditions was in descending order as follows: Freezer (_20°C), Fridge (S-BoC), room temperature in black bags (22-24°C) and room temperature in clear bags (22-24°C). Leaching of dietary ascorbic acid increased with increasing immersion time and water temperature. Stability and price of each form evaluated suggested that GCAA is to be preferred for use in fish feeds. The antioxidant effects of ascorbic acid were investigated. The results showed that ascorbic acid was not as effective as butylated hydroxy toluene (BHT) in preventing in vitro oxidation. An experiment was conducted to compare the performance of a commercial trout diet with the same diet supplemented to a level of l2Smg ascorbic acid/lOOg diet (Diet 2) when fed to O. niloticus. Fish fed the supplemented diet performed significantly better in terms of growth and food utilization concomittant with significantly increased tissue ascorbate concentrations. Sex differences in relation to dietary ascorbic acid nutrition were investigated. Females of both species exhibited significantly higher gonado~ and hepatosomatic indices than males. Females in both species eXhibited higher total ascorbate concentrations in gonad, gills, spleen, brain and blood than males whereas the reverse was true for the eyes. Dehydroascorbic acid (DHAA) levels were very low in tissues of both species. Ascorbic acid depleted O. niloticus fingerlings were fed on each of three diets providing nil, adequate Cl2Smg ascorbic acid/lOOg diet), and luxus (400mg/lOOg diet) of the vitamin after small surgical incisions had been made in dorsolateral musclature. Fish from each group were sampled regularly over 16 days and histological evaluation of the lesion area carried out as well as measurement of the tissue ascorbate levels. Epithelial elements of the healing process developed irrespective of the vitamin level but although fibroblast activity was marked in all three groups, collagenisation was very much slower in the deficient group, and in these the lesion was not mature, even at the termination of the experiment. The role of ascorbic acid in reproduction of tilapias was investigated in three experiments. The first showed that ascorbic acid supplementation of broodstock feed improved both hatchability and fry condition. In the second experiment fry produced from fish fed an unsupplemented diet and subsequently fed the same diet performed poorly in respect of growth and food utilization. Fry produced from broodstock fed the supplemented diet and subsequently fed the unsupplemented diet performed better than the previous group. This indicates transfer of ascorbic acid from the ovary to the eggs thence to the fry providing some protection against ascorbic acid deficiency during the early stages of life.

Après 35 ans d'absence apparente, le virus West Nile (VWN) est responsable depuis 2000 de cas humains sporadiques et d'épizooties équines sur le littoral méditerranéen français. Nous avons étudié sans a priori quelles espèces de moustiques pouvaient être impliquées dans les cycles de transmission de ce virus dans le foyer camarguais.<br />Pour identifier les espèces vectrices, nous avons conduit des captures sur appâts oiseau, cheval et homme de mai à octobre 2004, recherché le VWN chez les moustiques capturés et réalisé des infections expérimentales des candidats vecteurs. Pour estimer le risque d'infection, la formule de la capacité vectorielle a été généralisée à plusieurs espèces d'hôtes et de vecteurs et spatialisée. Une démarche pour l'estimation spatio-temporelle des densités de vecteurs a été proposée, en se basant sur des modèles de dynamique de population et sur une cartographie des milieux propices au développement larvaire et au déplacement des vecteurs.<br />Les conclusions de cette étude sont que Culex modestus Ficalbi est sans doute le principal vecteur enzootique (transmission au sein des populations d'oiseaux) et épidémique (transmission des oiseaux aux mammifères) du VWN dans les zones humides. Sa distribution doit être précisée pour estimer l'importance de son rôle en zone sèche. Culex pipiens L. est sans doute un vecteur enzootique important dans l'ensemble de la Camargue et le principal vecteur épidémique en zone sèche, où les déterminants génétiques ou environnementaux de ses préférences trophiques restent à éclaircir. Enfin, les principales espèces d'Aedes et Anopheles n'ont sans doute qu'un rôle mineur dans la transmission du VWN.

Mosquito species of the Culex genus are the enzootic vectors for several bird-associated viruses that cause disease in humans. In Europe, these viruses include Sindbis (SINV), West Nile and Usutu viruses. The morphologically similar females of Cx. torrentium and Cx. pipiens are potential vectors of these viruses, but difficulties in correctly identifying the mosquito species have caused confusion regarding their respective distribution, abundance, ecology, and consequently their importance as vectors. Species-specific knowledge from correctly identified field material is however of crucial importance since previous research shows that the relatively unknown Cx. torrentium is a far more efficient SINV vector than the widely recognized Cx. pipiens. The latter is involved in the transmission of several other viruses, but its potential importance for SINV transmission is debated. In this thesis I describe the development of a molecular method for species identification, based on reliably identified males of Cx. torrentium and Cx. pipiens. This identification method was then used in consecutive studies on the distribution and relative abundance of the two species in Sweden and 12 other European countries, SINV field infection rates in mosquitoes identified to species level, and evaluation of potential trap bias associated with common sampling techniques. The results showed that Cx. torrentium is a far more common species in Europe than previously assumed. In Sweden and Finland, it is the dominant species, accounting for 89% of the sampled Culex population. In central Europe, it is equally common to Cx. pipiens, while Cx. pipiens dominates south of the Alps Mountain range. Larvae of both species are often found together in both artificial containers (e.g. car tires) and natural sites. Also, a trapping bias against Cx. torrentium was revealed for CDC-traps. For the first time, SINV was isolated from species-identified Cx. torrentium and Cx. pipiens mosquitoes caught in the field, with Cx. torrentium being superior in infection rates (36/1,000 vs. 8.2/1,000). Future studies on SINV, as well as other mosquito-borne bird viruses in Europe, can hopefully gain from the baseline information provided here, and from principles of vector discrimination discussed in the thesis.

Produced through relations of power, West Nile Virus (WNV) as it exists on the Public Health Agency of Canada's (PHAC) website, is an effect of the kinds of knowledge, techniques of power. and disciplinary apparatuses that operate on the website and in society. Cumulatively, these forces have produced WNV as a bio-socio-administrative construct. With reference to Michel Foucault's relations of power and to Jennifer Gore's operationalization of Foucault's techniques of power, this thesis both describes the PHAC's overall production of WNV and analyzes the production process. This thesis illustrates one way that Foucault's theories of power can be used to conduct a social construction analysis. The study also shows conclusively that power relations are an important factor in the production of newly emergent infectious diseases in Canada. It will be of value to other researchers who are interested in the sociological study of disease, public health, and risk.

Das West-Nil-Virus (WNV) ist eine Zoonose mit weltweit zunehmender Verbreitung. Natürliches Reservoir dieses Flavivirus sind Vögel, aber auch Säugetiere wie z.B. Menschen können infiziert werden. In einigen Fällen führt eine WNV-Infektion zu schweren neurologischen Erkrankungen. Infolgedessen werden effektive und biologisch sichere Impfstrategien gegen dieses Virus benötigt. Eine Alternative zu herkömmlichen Impfmethoden beschreibt die DNA-Immunisierung. In dieser Arbeit wurde ein potentieller DNA-Impfstoff gegen das WNV hergestellt. Die Immunisierung des DNA-Vektors induzierte starke zelluläre und humorale Immunantworten in Mäusen. Zudem waren die Tiere gegen eine WNV-Infektion geschützt. Zusätzliche Impfungen mit rekombinantem WNV-Protein führten zu einer weiteren Steigerung der Immunogenität des DNA-Impfstoffkandidaten. Des Weiteren sollte der nicht-virale Gentransfer im Allgemeinen optimiert werden. Ein neu entwickeltes Transportsystem für Plasmid-DNA, bestehend aus natürlichen Histonextrakten und Polyethylenimin, resultierte in einer verbesserten Proteinexpression in in vitro transfizierten Zellen und wurde von diesen sehr gut toleriert. Daher wäre diese Strategie auch für zukünftige DNA-Impftechniken denkbar. Der Einfluss von WNV auf die Expression zellulärer miRNAs in Wirtszellen wurde bisher noch nicht untersucht. Dennoch könnten auf diese Weise potentielle molekulare Biomarker für eine frühe WNV-Diagnose identifiziert werden. Mittels Microarray-Technik wurde die Expression zellulärer miRNAs analysiert. Verschiedene miRNA-Spezies waren infolge einer WNV-Infektion leicht herunter- bzw. hochreguliert und stellen mögliche diagnostische Biomarker für das Virus dar.