The sustainability of municipal drinking water services in the Niger Delta region of Nigeria requires that its water utilities enhance their resilience to a range of risks posed by extreme weather events. Excellence in managing such risks is essential, not only to the bottom line and reputation of the utilities, but also to the wellbeing and prosperity of the people they serve and the preservation of nature in order to sustain ecosystem services. In the context of this study, organisational resilience has been defined as the adaptive deployment of the utility s assets and structures within its continua of inter-dependences to improve and sustain performance even in the face of repeated perturbations. On the other hand, vulnerability is defined as the utility s inability to withstand adverse stress based on limited or constrained capacity to adapt hence creating pathways through which risk impacts the utility. This definition of vulnerability is in tandem with those that argue that the key parameters of vulnerability are the stress to which a system is exposed, its sensitivity, and its adaptive capacity. In view of this, and also based on the findings of the study, the study notes that utility management could be a complex and challenging task, especially, in a multi-risk delta environment where extreme events are intense and frequent. Utility managers can become veterans of risks by dissipating, more than ever before technical competence, watershed/ecosystem awareness, social engagement skills and conceptual ability. The latter includes an understanding of how the complexities of the upstream and downstream environment impacts on the utility s internal environment and operations. The diffusive nature of risk makes every risk a potential high impact risk and the understanding of this, is the key to a resilient organization. Risk analysis and management in water utilities should aim to limit the diffusion of risks across streams in order to retard vulnerability. Utility resilience options will need to vary depending on climate related risks to each system, utility management goals, legislation, local and national water management strategies and finance. Utilities in the Niger delta needs to fully understand that they operate close to the edge by virtue of being below sea level and should cultivate a keen awareness of the consequences of flooding and saltwater intrusion, and the importance to manage them amongst others. The study has shown that there is need now, more than ever before for increased revenue generation, elimination of wastes/inefficiencies, financial investment and strategic management of water services operations in the study area if residents and the unborn generation are to be guaranteed of safe and adequate drinking water.

‘Sons of the soil’ conflicts seldom intensify above a low level of intrastate violence. Although frequent, they tend to remain small in scale, which has contributed to a lack of scholarly understanding about why some Sons of the soil conflict yet intensify more than others. Taking the role of the state into account, this study aims to investigate the causes for intensification in these conflicts. With a neoclassical realist approach, domestic factors behind the causal process of conflict intensification are unearthed, thereby investigating further the action-formation of the government threat perception. It leads the study to test the following hypothesis: A Sons of the soil conflict is more likely to intensify if the government misperceives the threat the conflict constitutes. Through a comparative process tracing analysis of Sons of the soil conflict intensity in Mali and Niger, 2006-2012, findings suggest that certain domestic factors at the state level cause a significant variation in the outcome. Actual low threats of Sons of the soil conflict may in fact be intensified due to state misperceptions.

The black caiman (Melanosuchus niger) and the yacare caiman (Caiman yacare) have in the past been exposed to overexploitation due to the economic profit for their hides, and therefore suffered from great declines in population sizes, especially black caimans. Legal regulation efforts made it possible for these two species to recover and today they are widely distributed in South America. Evaluation of protection and management of populations of top predators like these caimans depend on the ability to detect the animals. The probability of detecting a crocodile, or any animal, is affected by several factors such as habitat complexity and behaviour why it is of importance to acknowledge such matter in order to obtain reliable results for further implications. This study aims to investigate the detection probability and abundances in these two species as a contribution to the monitoring efforts at a local scale. Night counts were performed in Cedral lagoon located in the Beni region in Bolivia. By using the relation between marked animals and resightings of them, as well as the abundance estimate produced by the Lincoln-Petersen estimator, estimates of detection probabilities could be accounted for the total caiman population (black plus yacare caimans) and the black caiman population. Very low sighting probabilities (p = 0.03) were obtained when based on marked animals who tend to be more wary after a capture event. Those based on the L-P output were higher (total caiman population p = 0.15, black caimans p = 0.15). Population sizes were estimated to 25 ± 8.5 black caimans and 34 ± 12 caimans in total. The population size based on marked animals was 12 ± 25.4 caimans.

La Biotransformación del Naproxeno, [(S)-6-metoxi-α-metil-2-ácido naftalenacético ], fue realizada utilizando el Aspergillus niger, microorganismo que se caracteriza por su capacidad para hidroxilar sistemas aromáticos. Dicho proceso biotecnológico fue llevado a cabo en un medio líquido bajo condiciones óptimas para el desarrollo del Aspergillus niger. Se obtuvieron 2 metabolitos mayoritarios demetilnaproxeno y 7-hidroxi-6-demetilnaproxeno; los cuales fueron aislados mediante técnicas cromatográficas, e identificados mediante espectroscopia de RMN ( H+ ) y espectrometría de Masas. El 7-hidroxi-6-demetilnaproxeno fue metilado mediante reacciones químicas a 7-metoxi-6-metilnaproxeno; y sometido al ensayo del Modelo Experimental del Edema Pedal Inducido por Carragenina para evaluar la actividad farmacológica, se utilizo como patrón de comparación al Naproxeno Base, y Naproxeno Sódico, donde se determinó que el metabolito metilado no presentaba efecto anti-inflamatorio. Palabras Clave: Biotransformaciones, Naproxeno, Aspergillus niger, Actividad Anti-inflamatoria, 6-demetilnaproxeno, 7-hidroxi-6metilnaproxeno, 7-metoxi-6metilnaproxeno. / -- The Biotransformation of Naproxen [(S)-6-methoxy-α-methyl-2- naphtaleneacetic acid ], was performed using a microorganism Aspergillus niger, wich has knowed ability of hydroxylate aromatic rings. This biotechnological process was conduced in a liquid culture in optimum conditions for development of the microorganism.Two main metabolites was gotten: 6-desmethylnaproxen and 7-hydroxy-6 desmethylnaproxen, these were isolated by chromatographic techniques and identified by RMN ( H+ ) Spectroscopy and Mass Spectrometry. The 7-hydroxy-6-desmethylnaproxen was methylated by chemical reaction to 7-metoxhy-6-methylnaproxen and was used the model Carrageenin-induced paw edema to evaluated the pharmacological activity, was used such as standard naproxen, and naproxen sodium. It was determinated that the methylated metabolite has not showed anti-inflammatory activity. Keywords: Biotransformation, Naproxen, Aspergillus niger, Anti-inflammatory activity, 6-desmethylnaproxen, 7-hydroxy-6 desmethylnaproxen, 7-metoxhy-6-methylnaproxen.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Nitrilases are well known for their unique property to effectively convert nitriles into corresponding carboxylic acids and ammonia. They can also form amides as by-products. In contrast to nitrile hydratases they do not require cofactors or prosthetic groups. The research in this work is focused on nitrilase from filamentous fungus Arthroderma benhamiae and cyanide hydratase from Aspergillus niger K10. Genes of these enzymes were expressed using pET-30a(+) plasmid in the bacterium Escherichia coli strain BL21-Gold (DE3). The products obtained were purified by a series of ion exchange chromatography and gel filtration and subsequently characterized with respect to oligomeric state of the protein and its usability for protein crystallography. To obtain information regarding the structural arrangement of the individual proteins, electrophoretic separation in polyacrylamide gel, gel filtration, analytical ultracentrifugation, mass spectrometry, dynamic light scattering and drop coating deposition Raman spectroscopy were used. Keywords: nitrilase, cyanide hydratase, Aspergillus niger, Arthroderma benhamiae, liquid chromatography (In Czech)

Orientador: Valéria de Carvalho Santos Ebinuma / Coorientador: Jorge Fernando Brandão Pereira / Banca: Luis Henrique de Souza Guimarães / Banca: Elias de Souza Monteiro Filho / Banca: Ariela Veloso de Paula / Banca: Álvaro de Baptista Neto / Resumo: As lipases são biocatalisadores que têm como função natural a hidrólise de triglicerídeos na interface lipídeo-água, e apresentam também a capacidade de síntese de ésteres. Quando estas enzimas são produzidas de microrganismos, dependendo da sua aplicação final, existe a necessidade de extrair e purificar a enzima do meio fermentado. Desta maneira, o objetivo deste trabalho foi estudar a estabilidade da lipase comercial de Aspergillus niger frente aos agentes formadores de Sistemas de Duas Fases Aquosas (SDFA) e a capacidade de diferentes SDFA como plataforma de extração da lipase comercial de Aspergillus niger e posterior da lipase de Aspergillus sp. produzida em meio fermentado. Primeiramente foi realizado o estudo de atividade e estabilidade da enzima comercial frente aos agentes formadores dos SDFA, empregando tensoativo, polímeros, Líquidos Iônicos (LIs) e carboidratos. Os resultados mostraram que a lipase comercial é estável em solução aquosa de Triton X- 114, PEG 600 e PPG 400, enquanto, que com PPG 425 a atividade foi mantida em tampão Mcllvaine pH 5,5. Os polímeros PPG 725 e NaPA 8.000 inibiram a atividade enzimática tanto em solução aquosa quanto em tampão pH 5,5. Na presença dos LIs, o aumento da cadeia alquílica catiônica, para os cloretos de imidazólios ([Cnmim]Cl), e aniônica, para a família das colinas ([Ch]X), acarretaram em perda de atividade comprometendo o comportamento catalítico da enzima. Na presença dos carboidratos a lipase manteve sua estabilidade. Na... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Lipases are natural biocatalysts for the hydrolysis of triglycerides at the lipid-water interface and with the ability to synthesize esters. When these enzymes are produced by microorganisms, depending on its final application, it is needed to extract and purify them. Therefore, the aim of this work was to study the stability of the Aspergillus niger commercial lipase in the presence of different aqueous two-phase systems (ATPS) forming agents, and to evaluate the ability of different ATPS as extractive platforms of the Aspergillus niger commercial lipase and after Aspergillus sp. lipase produced in fermented medium. Initially, the activity and stability of the commercial lipase in the presence of ATPS forming agents were studied, namely: surfactant, polypropylene glycol, ionic liquids (ILs) and carbohydrates. The results showed that commercial lipase is stable in the presence of Triton X-114, PEG 600 and PPG 400 aqueous solutions, whereas with PPG 425 aqueous solutions the enzyme maintained its activity at Mcllvaine buffer pH 5.5. Both PPG 725 and NaPA 8,000 aqueous solutions (water and buffered at pH 5.5) inhibited the catalytic activity. In the presence of ILs, the increase of the cationic alkyl chain, using of the imidazolium-based chlorides family ([Cnmim]Cl), and anionic, for the cholinium family ([Ch]X), resulted in a loss of enzymatic activity, compromising the catalytic behavior of the lipase. On the other hand, lipase remained stable in the presence of all carbohydr... (Complete abstract click electronic access below) / Doutor

This study focused on how changes in food availability during the dry season, influenced various aspects of sable (Hippotragus niger niger) foraging and social ecology. The main purpose of this was to determine whether differences in their foraging ecology explained the reduction in population size compared to other more abundant herbivores (e.g. zebra, buffalos, hartebeest). Contrary to expectation, sable did not limit their foraging to woodlands, but also fed in open grasslands, provided these retained green grass during the dry season. Wetlands were key resource areas during the dry season, but sable did not limit their feeding to these bottomland areas. They also fed on hill slopes and upper plateaus that had been burnt. During the study, sable were attracted to burnt areas despite the reduced grass availability. My study highlights how these burnt areas were important in alleviating nutritional deficiencies during the dry season. At lower spatial levels, I looked at the factors that influenced the selection of feeding areas and plant species. Like other grazers, sable were attracted to green leaves but did not avoid brown leaves or stems. Grass species eaten were the same as those preferred by most domestic and wild grazers. Surprisingly, adult males stayed with the breeding herds despite their different activity budgets. Unlike most other African grazers, sub adult sable males did not form bachelor groups. Instead, they stayed within the breeding herds the whole time and had a similar activity budget to females. As adult males moved with the breeding herds, I was able to examine the costs and benefits involved with such a social structure. From this, I was able to relate my results to the bigger picture of factors influencing sexual segregation in ungulates. In conclusion, sable utilised a wide variety of habitat types and adjusted their foraging behaviour to accommodate different seasonal situations. I was unable to find anything in their feeding ecology that could explain the continued decline in population size. Therefore, I suggest that future research needs to focus on other potential causes such as a higher susceptibility to predation and disease as compared to more abundant herbivore species.

The thesis focuses on the protracted tripartite conflict within and between local oilbearing communities of the Niger Delta on the one hand, and between them, the state and foreign oil multinationals in the region, on the other hand. The focus also centers around how this has attracted international attention and the impact of internationalization on the conflict itself. The series of crises have been underpinned by tortuous issues on the ground for over four decades. There was a new dimension to the struggle in the early 1990s, which redefined the focus of the crises, when organized pressure groups protested against the inhuman and environmental hazards in the region. The thesis therefore examines the interest(s) of the main actors involved in the crisis in the period between 1993 and 2003 in order to establish the issues that accounted for the involvement of the international civil societies. The thesis makes three significant arguments: one, that the differences in interests among the actors in relation to the issue of oil production and its impact on the local people laid the basis for the persistent struggle between the social movements/militant youths on one side and the state and oil multinationals operating in the region on the other. The second argument the thesis advances is that the age-long crisis in the region became an agenda for the international community in the 1990s because of the trend and impact of globalization This invariably allowed international Non-Governmental Organizations to intervene in exerting pressures on oil companies and the state to re-examine their policies in the region. Finally, the recent internationalization of the crisis has not impacted enough to significantly address the demands of the people with the locally based pressure and, later, INGOs. This approach is intended to establish a pattern of alliances in the Niger Delta crisis. It might be healthy to state, ab initio, that there was a convergence of interests between the state and MNOCs on the one hand and between the social movements, local NGOs and INGOs on the other hand. The thesis employed a multivariate form of data collection from primary sources like Multinational Oil Companies in the area especially, Shell Petroleum Development Company (SPDC), Department of Petroleum Resources (DPR) and the Nigerian National Petroleum Corporation (NNPC), interviews with local people, NGOs and some government officials, with extensive use of secondary data on the Niger Delta. The study’s findings suggest that the internationalization of the crisis has engendered new approaches and attitudes on the part of the key actors in the Niger Delta. For its part, the state has adopted the agency approach in dealing with the issues confronting the region. Shell has increased its direct intervention efforts in addressing the demands of the local communities. However, these new approaches and attitudes have yielded minimal results in view of the militarization of the Niger Delta through the continuous deployment of troops by the state and the oil multinationals under the guise of security imperatives in response to the people’s agitations, which are poverty driven.

Au cours de ce travail de thèse ont été développés des outils théoriques (simulation) et expérimentaux (tracking) d’investigation des mécanismes sous-jacents aussi bien aux phénomènes de choix collectifs d’exploitation de sources de nourriture qu’à la gestion collective de cette dernière lors de la constitution des stocks de nourriture au sein d’une colonie de fourmis. Un premier volet de mon travail a concerné l’influence des caractéristiques physiques de l’environnement extérieur à la colonie sur les choix collectifs des fourmis en termes d’exploitation de ressources alimentaires. A la sortie du nid, les fourmis montrent une nette préférence pour un chemin ascendant plutôt que descendant vers des sources de nourriture pourtant identiques. Ce choix s’explique notamment par un mécanisme de demi-tour au niveau individuel face à une pente descendante dont l’effet est renforcé par des feedbacks positifs inhérents au phénomène de recrutement. Les capacités d’orientation et d’intégration du parcours entre le nid et la source de nourriture ont également été testées. Un chemin menant du nid à la source de nourriture selon une trajectoire parfaitement rectiligne est largement plus emprunté qu’un chemin impliquant un angle (135°) à mi-parcours bien que la distance absolue entre le nid et les deux sources de nourriture soit identique. Ce choix est expliqué par des durées de trajets de retour au nid plus longues sur le chemin avec un angle que celles sur le chemin rectiligne, conséquence de désaccords entre la direction à emprunter pour retourner au nid et le phénomène d’intégration de chemin observé chez les fourmis. Un second volet de ma thèse a été consacré à l’étude des dynamiques et régulations à l’oeuvre au sein des phénomènes de dissémination collective et d’accumulation de nourriture au niveau intranidal. Ces questions ont été abordées par des méthodes d’analyses complémentaires mêlant des approches théoriques et expérimentales ayant permis d’établir les liens entres les hétérogénéités comportementales au niveau individuel et les résultantes de ces comportements au niveau collectif. Le marquage individuel des fourmis à l’aide d’une méthodologie également développée au cours de cette thèse, a permis la construction du réseau de trophallaxies au sein deux espèces de fourmis. Malgré des différences au niveau biologique, celles-ci présentent des similarités comportementales :chacune montre une nette hétérogénéité interindividuelle dans le niveau de participation à l’activité de dissémination de la nourriture dans le nid. Des simulations basées sur les données expérimentales montrent que ces hétérogénéités individuelles conduisent à l’émergence d’un réseau de diffusion de nourriture plus efficient que si la colonie était parfaitement homogène. De plus, il a été montré que la structure des réseaux de distribution de nourriture après une longue période d’affamement n’est pas affectée par la qualité de la nourriture, suggérant une résilience des structures fondamentales de l’organisation sociale face à la variabilité des ressources. Ainsi ce travail, par son approche complémentaire entre modélisation fonctionnelle et expérimentation se veut également être une synthèse et une intégration de l’essentiel des connaissances actuelles des lois régissant la gestion collective des ressources alimentaires chez les fourmis. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished