abstract: Banded iron formations (BIFs) are among the earliest possible indicators for oxidation of the Archean biosphere. However, the origin of BIFs remains debated. Proposed formation mechanisms include oxidation of Fe(II) by O2 (Cloud, 1973), photoferrotrophy (Konhauser et al., 2002), and abiotic UV photooxidation (Braterman et al., 1983; Konhauser et al., 2007). Resolving this debate could help determine whether BIFs are really indicators of O2, biological activity, or neither. To examine the viability of abiotic UV photooxidation of Fe, laboratory experiments were conducted in which Fe-bearing solutions were irradiated with different regions of the ultraviolet (UV) spectrum and Fe oxidation and precipitation were measured. The goal was to revisit previous experiments that obtained conflicting results, and extend these experiments by using a realistic bicarbonate buffered solution and a xenon (Xe) lamp to better match the solar spectrum and light intensity. In experiments reexamining previous work, Fe photooxidation and precipitation was observed. Using a series of wavelength cut-off filters, the reaction was determined not to be caused by light > 345 nm. Experiments using a bicarbonate buffered solution, simulating natural waters, and using unbuffered solutions, as in prior work showed the same wavelength sensitivity. In an experiment with a Xe lamp and realistic concentrations of Archean [Fe(II)], Fe precipitation was observed in hours, demonstrating the ability for photooxidation to occur significantly in a simulated natural setting. These results lead to modeled Fe photooxidation rates of 25 mg Fe cm-2 yr-1—near the low end of published BIF deposition rates, which range from 9 mg Fe cm-2 yr-1 to as high as 254 mg Fe cm-2 yr-1 (Konhauser et al., 2002; Trendall and Blockley, 1970). Because the rates are on the edge and the model has unquantified, favorable assumptions, these results suggest that photooxidation could contribute to, but might not be completely responsible for, large rapidly deposited BIFs such those in the Hamersley Basin. Further work is needed to improve the model and test photooxidation with other solution components. Though possibly unable to fully explain BIFs, UV light has significant oxidizing power, so the importance of photooxidation in the Archean as an environmental process and its impact on paleoredox proxies need to be determined. / Dissertation/Thesis / Masters Thesis Biochemistry 2017

Conflict within and between social groups is a conspicuous feature of cooperative animal societies. Theoretical and empirical research aims to understand the role of within- and between-group conflict in the evolution of cooperative behaviour, but these forms of conflict are rarely studied together. Eviction as a means of within-group conflict resolution can have important implications for the individuals involved, and the wider population through effects on dispersal, gene flow, and population structure. Intergroup conflict, although prevalent in many social species, is relatively understudied outside of humans and chimpanzees, but could play an important role in the evolution of cooperative behaviours. However, currently there is a lack of understanding of the causes and consequences of within- and between-group conflict to be able to draw conclusions on theoretical links to their role in social evolution. In this thesis, I use a wild population of banded mongooses, Mungos mungo, to investigate the causes and consequences of eviction and intergroup conflict in a highly cooperative species. First, I show that eviction in banded mongooses is triggered by reproductive competition in both sexes (Chapter 2). Second, I find that, once the decision to evict has been made, younger females and those older, more closely related females are preferentially evicted (Chapter 3). This surprising result is explained by a theoretical model which shows that, where individuals are capable of resisting eviction, the usual prediction of positive kin discrimination can be reversed. Third, I show that eviction has demographic effects, with consequences for group size and recruitment (Chapter 4). Finally, I show that intergroup conflict is stimulated by intensified resource competition, and that the consequences of intergroup conflict can have measureable costs to both individuals and groups in the long- and short-term (Chapter 5). This work shows that the means of resolving within-group conflict at an individual level can resonate to affect demography and dynamics at higher levels, and that the nature and intensity of intergroup conflict has the potential to influence patterns of cooperation and conflict within groups. I suggest that within- and between-group conflict may often be intimately linked, and that recognising this link could help to advance our conceptual understanding of their role in the evolution of cooperative behaviour.

Animals in captivity can be deprived of performing some of their natural behaviours. Using enrichments may allow them to express a larger part of species-specific behaviour repertoire and with a better frequency distribution. This study focuses on three species of the family Herpestidae which live in captivity at Bioparc Valencia (Spain). The project aims to study the effect of environmental enrichment on the behaviour of meerkats, banded mongooses and dwarf mongooses in human care. To achieve this goal two different types of enrichmentswere tested: (1) a food enrichment with several variations and (2) an olfactory enrichment with the presentation of two new odours. The food enrichment aimed to increase foraging behaviour and the olfactory enrichment aimed to test if captive animals behave differently in the presence of a predator’s odour compared to a non-predator’s odour. Results revealed that foraging can increase up to 16% implementing enrichments and that success depends on the presence and quantity of food. On the other hand, animals did not seem to behave differently in the presence of both odours. The frequencies of behaviours and time spent interacting did not differ between these olfactory enrichments. I conclude that implementing enrichment programmes may ensure better welfare for captive animals.

Genetic, ecological, and environmental variation within and among populations of hosts and pathogens can influence local susceptibility of hosts and transmission rates of pathogens. These complex interactions can lead to geographic variation in the prevalence of pathogens. The interaction between leprosy and nine-banded armadillos in the southeastern U.S. provides an opportunity to examine the genetic, ecological, and environmental factors contributing to the variation in pathogen prevalence on a large geographic scale. Using genotypic data for loci associated with the immune response to leprosy and for anonymous loci, we have assessed the population structure of armadillo populations across the southern U.S. Additional statistical tests were used to assess any significant differences between functional and anonymous loci that indicate selection. Our results suggest that local adaptation does not influence the geographic distribution of leprosy in armadillo populations and that very little genetic variation can be attributed to differences among host populations.

No description available.

SPIKE is a parallel algorithm to solve block tridiagonal matrices. In this work, two useful improvements to the algorithm are proposed. A flexible threading strategy is developed, to overcome limitations of the recursive reduced system method. Allo- cating multiple threads to some tasks created by the SPIKE algorithm removes the previous restriction that recursive SPIKE may only use a number of threads equal to a power of two. Additionally, a method of solving transpose problems is shown. This method matches the performance of the non-transpose solve while reusing the original factorization.

Understanding the disease transmission dynamics in wildlife species can be difficult and can prove more complicated if the population structure of a socially living species is shaped by territoriality. Understanding the connections and movements of individuals between groups is vital to documenting how a disease may be spread. The presence of a heterogeneous landscape can further complicate attempts to describe transmission of an infectious disease. Here, I sought to understand how dispersal patterns of individual banded mongooses (Mungos mungo) could potentially influence disease transmission. Banded mongooses are small fossorial mammals that live in social groups ranging from 5 to 75 individuals and defend their territories against rival troops. The focal population of mongooses for this study lives across a complex environment in the Chobe district of northern Botswana and is faced with a novel strain of tuberculosis, Mycobacterium mungi. To infer genetic structure and individual movements between troops, I utilized microsatellite genetic markers and population genetic analyses. I found moderately strong genetic structuring (FST = 0.086) among 12 troops of banded mongooses in the study area in 2017-18. The best supported number of genetic clusters was K = 7, with a considerable amount of admixture between troops in urban areas. Compared to the average pairwise differentiation values of troops residing in natural habitats (FST = 0.102), urban troops had a lower level of differentiation (FST = 0.081), which suggests more gene flow between these troops. Among 168 mongooses genotyped, 20 were identified as being likely dispersers, with the majority moving across anthropogenic environments, suggesting that dispersal is heightened in urbanized areas. To assess whether temporal variation had an effect on genetic structure and gene flow between troops, I compared population genetic results from 5 troops in 2008 to those from the same 5 troops in 2017. Genetic differentiation was lower between troops living in urban environments than in natural environments for both 2008 and 2017. This result suggests higher gene flow across the anthropogenic landscapes at both times steps. The overall genetic structuring of the troops persisted over almost a decade, with the exception of observing more mixture and admixture in 2017 than in 2008. The effective population sizes (Ne) of troops were larger in 2008, which would indicate that genetic variability declined as time progressed. For 11 individuals confirmed to have M. mungi, an assignment test suggested that 3 mongooses were likely dispersers. This finding would contradict that of previous work, which suggested that sick banded mongooses refrained from dispersing. Sequencing of the M. mungi strains would be needed to determine whether these dispersers moved while sick or became infected after entering their new troop. These findings suggest that emphasis should be placed on closely monitoring banded mongoose troops in areas with heavy human influence. Here we see lower pairwise differentiation, higher gene flow estimates, and more frequent dispersal events. Heightened dispersal potentially can result in elevated disease transmission between troops in urban habitats. With disease transmission being the result of complex interactions between environment, host, pathogen, and time, results from this study contribute to understanding of disease transmission dynamics. / MS / Understanding how groups of the same species are connected is important for assessing how wildlife diseases spread across a landscape. For social species, connections are established by the movements of individuals between different groups; however, these can prove difficult to observe. Further complicating our ability to infer connections and movements, groups often live under different environmental conditions, which can influence movement rates. I studied banded mongooses (Mungos mungo) living in northern Botswana to assess the role of individual movement on the potential for disease transmission. Banded mongooses are small ground-dwelling mammals that live in troops of 5-75 individuals and defend group home-ranges. In Botswana, some troops are infected with a species of tuberculosis (TB, caused by the bacterium Mycobacterium mungi) that is unique to banded mongooses. Using molecular genetic tools, I estimated how genetically similar troops were to one other and estimated the rates of movement of individuals between troops. I found that troops living in urban environments tended to be more genetically similar to one other compared to troops living in natural environments within nearby Chobe National Park. I also detected more cases of individuals moving between troops in urban settings, with little evidence of movement between troops living in natural areas. These results suggest that there is more genetic exchange and a higher degree of connection between troops living in areas heavily influenced by people. With more connections between town-dwelling troops, we would expect to see higher rates of disease transmission between these urban troops, and hence should monitor their movement and health status closely. I also assessed how genetic structure and connections between banded mongoose troops changed over time by comparing results for collections of samples made in 2008 and 2017. Although more movement was detected in 2017, the overall pattern of genetic connections remained similar over the ten-year period. In particular, there was greater genetic similarity between troops in town compared to troops in natural environments in both years. Additionally, I genetically assigned TB-positive individual mongooses to their troop of origin to determine whether sick individuals moved out of their original troops. I identified three sick individuals as probable dispersers, although it is difficult with the information available to know whether they moved while infected or became ill after joining a new troop.

Made available in DSpace on 2015-09-25T12:23:40Z (GMT). No. of bitstreams: 1 Raynner Rilke Duarte Barboza.pdf: 1650632 bytes, checksum: 348f5180de4d3fd395120b1b20a6cbc0 (MD5) Previous issue date: 2009-09-17 / This study addressed to obtain general information from the residents of five municipalities in the semi-arid region of Paraiba State (Campina Grande, Monteiro, São Mamede, Sousa, Sumé) about their knowledge on the ecological and behavioral (feeding, reproduction, habitat, predation and use) of two specimens of armadillos (Euphractus sexcinctus) and (Dasypus novemcinctus) that occurs in that area, as well as to describe and analyze the cinegetic activities and purposes of game hunting carried on these two species, seeking support conservation and management measures. Data collection was obtained through a combination of qualitative and quantitative methods. Among the qualitative methods: free interviews, semi-structured interviews, snow ball technique and guided tours were used; the quantitative data were done on simple averages and percentages in Microsoft ® Excel software and analyzed using the calculation of Fidelity Level (FL). Data were analyzed by an emic/ethics approach in which traditional knowledge were compared with those involved and/or related to the literature. 177 men and 37 women were contacted, whose ages ranged from 16 to 77 years. The results showed that the information regarding the foraging, ecological niche and reproduction were described in a very elucidating way by most of the interviewees, demonstrating a deep knowledge and perception on the ecology and biology of the two species of armadillos studied. Such levels of perception are directly linked to regional and cultural issues of each locality and the practices of creation of those animals in captivity also. The main hunting techniques and capture of those animals were: firearms, with dogs, the use of wire-dog and bucket with water. The people of the semi-arid of Paraiba use the E. sexcinctus and D. novemcinctus such in the local gastronomy, as for medicinal and magical-religious purposes, which were documented in this work for the treatment of 10 conditions or diseases: asthma, earache, wounds, furunculosis, deafness, blocked nose, insect bites, rheumatism, and varicose veins and warts. The practice of recreational and commercial hunting was documented in this research by the residents of the studied localities. From a conservation perspective, the techniques and methods of game described in this work can bring major impacts on population dynamics of these two species of armadillos. Additional studies on the activities of hunting will be useful to contribute to proposals for rules and laws that may regulate the controlled hunting in each region and for implementation of management plans and sustainable use of these species. / Este trabalho teve como objetivo geral obter informações junto a moradores de cinco municípios do semi-árido do Estado da Paraíba (Campina Grande, Monteiro, São Mamede, Sousa, Sumé) acerca dos conhecimentos ecológicos e comportamentais (alimentação, reprodução, habitat, predação e utilização) que os mesmos possuem sobre os tatus-peba (Euphractus sexcinctus) e tatus verdadeiros (Dasypus novemcinctus), bem como analisar e descrever as atividades cinegéticas e finalidades da caça exercida sobre essas duas espécies de tatus, visando subsidiar medidas de conservação e manejo. Para obtenção dos dados, utilizou-se uma combinação de métodos qualitativos e quantitativos. Dentre os métodos qualitativos, destacam-se: entrevistas livres, semi-estruturadas, bola de neve ou snow Ball em inglês e turnês guiadas já os dados quantitativos foram trabalhados em médias e porcentagens simples no software Microsoft® Excel e analisados por meio do cálculo do Nível de Fidelidade (FL). Os dados obtidos foram analisados por meio de uma abordagem emicista/eticista, na qual os conhecimentos tradicionais foram comparados com aqueles correspondentes e/ou correlacionados na literatura científica. Foram contactados 177 homens e 37 mulheres com atividades relacionadas aos tatus, cujas idades variaram de 16 a 77 anos. Os resultados obtidos mostraram que as informações referentes à alimentação, nicho ecológico e reprodução foram descritas de maneira muito elucidativa pela maioria dos entrevistados, demonstrando um profundo conhecimento e percepção sobre a ecologia e biologia das duas espécies de tatus estudadas. Tais níveis de percepção estão diretamente associados a questões regionais e culturais de cada localidade bem como as práticas de criação desses animais em cativeiro. As principais técnicas de caça e captura desses animais foram: Caça com armas de fogo, com cães e o uso de armadilhas como tatuzeiras ou pebeiras, também conhecidas como cachorro-de-arame; e Balde com água. Os povos do semi-árido paraibano utilizam os E. sexcinctus e D. novemcinctus tanto na gastronomia local como para fins medicinais e mágico-religiosos, onde foram documentados usos para o tratamento de 10 condições ou doenças: asma, dor de ouvido, ferimentos, furunculoses, mouquidão, nariz entupido, picadas de insetos, reumatismo, varizes e verrugas. Destaca-se nessa pesquisa o registro da caça para fins recreacionais e comercial por parte dos moradores das localidades estudadas. Sob uma ótica conservacionista, as técnicas e modalidades de caça descritas nesse trabalho podem trazer grandes impactos na dinâmica populacional dessas duas espécies de tatus. Estudos adicionais relativos a atividades de caça serão úteis de modo a contribuir com propostas de normas e leis que possam regular a caça controlada em cada região bem como para implementação de planos de manejo e uso sustentável dessas espécies.

Le soudage FSW (Friction Stir Welding) est un procédé de soudage en phase solide pressenti pour des applications de transport en générale aérospatial et naval. Malgré le nombre considérable d’études qui ont été réalisées depuis son avènement en 1991, le contrôle du procédé n’est pas encore effectif.Ce travail a consisté en une partie expérimentale visant à la génération, par un outil trigone, de joints soudés dont la microstructure a été corrélée à l’écoulement de matière pendant le procédé. La connaissance de cet écoulement de matière a permis dans la deuxième partie d’enrichir le modèle thermofluide développé en périodique pour prédire la microstructure des joints de soudure FSW, notamment les "onion rings". Finalement, l’occurrence des "onion rings" a été corrélée à la vitesse de déformation maximale atteinte par les particules de la zone soudée, prédite par le modèle. Par ailleurs, un travail d’affinement du champ de vitesse en voisinage du pion est réalisé en modélisant l’outil trigone. Ce qui permet en plus de l’interaction (entrainement) outil/matière par frottement, d’intégrer une interaction par obstacle. Cette approche devrait permettre, en perspectives de ce travail, une meilleur description thermomécanique locale et par voie de conséquence microstructurale. / Friction Stir Welding is a solid state joining process developed for transport applications as aerospace and naval. Since its introduction, a large number of investigations have been carried out but the process is not fully controlled. This work including experimental section in which welds have been generated by trigonal tool. The microstructure of these welds has been correlated with the material flow during the process. By understanding the material flow, the transient thermofluid model developed in the second section has been significantly enriched. This modeled has been developed for predicting the microstructure of the weld, especially, the "onion rings". Finally, the occurrence of "onion rings" has been correlated with the maximal strain rate reached by any particle in the weld seam, simulated by the model. However, the velocity has been refined at the vicinity of the tool through the trigonal pin modelling. This was helpful to move the material not only by friction but also by obstacle at the interaction tool/material. The above approach should enable, in this work layout, a better local thermomechanical description and consequently microstructural.

Memoria para optar al título de Geólogo / En la región de Pilbara, Australia, hay una gran cantidad de depósitos de hierro. En la zona destaca un depósito coluvial, cuyo material está siendo estudiado para ser utilizado en obras civiles. El objetivo de este estudio es caracterizar mineralógica y geotécnicamente el material. Para caracterizar el material se hizo una clasificación granulométrica, se describió geológicamente el material y se analizó los datos de un triaxial gigante realizados por IDIEM que aún no han sido publicados. A modo de entender los procesos internos de lo que ocurre en el triaxial, se hizo dos ensayos especiales: un corte directo entre dos rocas y un corte directo entre roca y suelo. La caracterización del material granular grueso se basó en descripciones macroscópicas de partículas, descripciones microscópicas de cortes transparentes y pulidos y determinación de propiedades físicas (densidad, absorción y porosidad). La resistencia de las partículas se estimó mediante ensayos de carga puntual y martillo de Schmidt. Adicionalmente, el material grueso se sometió a un ensayo de desgaste (slake). La mineralogía del material fino se caracterizó a través de un análisis de difracción de rayos x y espectrometría por infrarrojo (FTIR). Las principales conclusiones de este estudio son: el material se clasificó como gravas bien graduadas, GW, el ángulo de fricción del material es 30,15°, el ángulo de fricción entre roca-roca varía entre 11,2° y 15,4°, y el ángulo de fricción entre roca-suelo varía entre 15,2° y 19,3° dependiendo de la humedad. La mineralogía del material granular grueso está compuesta en mayor parte por hematita, magnetita y cuarzo. La resistencia a la compresión simple de las partículas es 101,24 Mpa. La mineralogía del material fino está compuesta por magnetita, hematita, cuarzo, goethita, muscovita, caolín y rutilo. El material grueso resultó resistente al desgaste.