This dissertation contends with the diverse corpus of Gothic ivory grooming implements carved in France in the thirteenth and fourteenth centuries. Employing feminist, queer, posthumanist, and ecocritical methodologies, it explores these objects as tools in gender and identity formation. Attending to the complexity of medieval attitudes to grooming and women and to the polysemy of these objects’ iconographies, this dissertation argues for the inherent ambiguity of the bodies that constitute and were constituted by these tools. It participates in a broader project of revealing the inherent ambiguity of medieval gender and its deep enmeshment with the nonhuman animal world by presenting ivory beauty implements as nexuses of excess and resistance to feminine ideals. Calling attention to the body of the elephant as the source of the grooming tools’ materiality, its analysis demonstrates how the subjugation of the nonhuman animal reverberates through objects created to give order to human animal bodies, in particular the bestial female body. The material, iconographical, functional, and textual strands wound together in ivory grooming tools reveal the women of flesh and ivory to be far more multilayered and subversive, resourceful and complex, than scholarship has hitherto recognized. At once tools of subjugation and instruments to assert agency, in the hands of their users, ivory grooming tools become sites of identity expression and self-transformation.

Menopause is characterized by prolonged lifespan beyond the point of reproductive cessation. Defined so that at least 25% of adulthood is nonreproductive, humans and some toothed whale species are the only groups that have been found to exhibit menopause. Menopause is a puzzling trait that seems to contradict classical evolutionary theory that equates selection operating on reproduction to selection operating on survival. I created two computational models to gain better understanding of the evolution of menopause. The first model explored why menopause is not observed in elephants despite their being characterized by key features in common with menopausal species, specifically offspring care from older females and longevity. Simulations allowed testing the effects of varying age at reproductive cessation and levels of offspring care, modeled by decreases in interbirth intervals. I found that hypothetical populations with greatest post-reproductive lifespans, characterized by longer interbirth intervals and earlier reproductive cessation, were most likely to be out-competed by contemporary elephants. Conversely, hypothetical populations that were most reproductively competitive, those with shorter interbirth intervals and older ages of reproductive cessation, returned post-reproductive lifespans that failed to meet the 25% post-reproductive lifespan criterion for menopause. I identified a small region in the parameter space where populations that were both menopausal and reproductively competitive evolved, but the majority of that region corresponds to biologically unrealistic scenarios. The scenario that is most feasible involves an interbirth interval of 4 years and an age at reproductive cessation of 40 years. The second model studied how menopause might have evolved in humans through a behavioural strategy of ending reproduction early to avoid risk of aneuploidy later in life and diverting resources toward extant kin. I found that populations that ceased reproduction earlier and exhibited greater post-reproductive lifespan returned lower reproductive success. The model also demonstrated that the aneuploidy avoidance behaviour is most successful when reproduction ends at approximately age 50. These concepts have never been explored computationally before, so these experiments contribute a novel simulation-based perspective to the growing body of knowledge surrounding the origin and evolution of menopause. / Thesis / Master of Science (MSc) / Menopause can be defined generally for a group as a life history characterized by prolonged post-reproductive lifespan. Defined specifically so that at least 25% of adulthood is nonreproductive, menopause has been recorded in only humans and some species of toothed whales. This trait presents an evolutionary puzzle, as it appears to contradict classical evolutionary theory, which suggests that reproduction should continue until the end of life. In this thesis, I use computational modeling to explore why elephants have not evolved menopause despite sharing key features with menopausal species and how aneuploidy might have contributed to the evolution of menopause in humans.

Darwin was troubled by elaborate male traits observed in many species that are seemingly maladaptive for survival, the peacock’s tail being the most iconic of all. He wrote "The sight of a feather in a peacock’s tail, whenever I gaze at it, makes me sick" because it challenged his theory of evolution by natural selection for adaptive traits. The extreme length of the tail may render a peacock more vulnerable to predation and therefore maladaptive for survival. To account for the evolution of apparently maladaptive traits he proposed the theory of sexual selection, wherein, traits that directly enhance mating success may be selected for, either as weapons in male-male competition for mates or as ornaments preferred by females. Male and female elephants in the proboscidean evolutionary radiation have had tusks and show extreme exaggeration in size and form. However, tusk in the Asian elephant (Elephas maximus) is sexually dimorphic as it is expressed only in the males, hinting at a possibility that opposing selection (sexual selection advantage to males and natural selection disadvantage to females) may have been the processes behind this pattern of tusk expression. Intriguingly, tuskless males (male dimorphism with respect to tusk) also occur at fairly high frequencies in some Asian elephant populations (∼50% in norteastern India and ∼95% in Sri Lanka). Theory states that dimorphic males can also occur in a population in stable frequencies as a consequence of sexual selection. I explored sexual selection on elephant tusks as possible mechanism leading to the observed patterns of tusk dimorphism in the elephants. All elephant populations on earth have been harvested for ivory, therefore, artificial selection (selective poaching of tusked elephants for ivory) is another possible cause of tusk dimorphism. I developed mathematical models of population genetics, population dynamics and conducted field observations of mating behavior of Asian elephant in Kaziranga National Park, Assam to understand the evolution of tusk dimorphism in elephants. Darwin’s sexual selection theory was controversial when proposed in 1871 and continues to remain so in 2014. In the introduction of my thesis I have discussed Darwin’s two classical mechanisms of sexual selection, namely, male-male combats for mates and female mate choice based on male traits. The latter was viewed with considerable skepticism by his con-temporary Alfred Russell Wallace and more recently deemed "fundamentally flawed" by Joan Roughgarden. Therefore, I have also discussed the arguments against female mate choice for male traits found in literature. I have reviewed current knowledge about sexual selection for sexually dimorphic male traits of body size and musth, in the African and Asian elephant and state why I have hypothesized that tusks may also be under sexual selection. Sexually selected traits are expected to be genetically determined, therefore, I explored mathematically (Chapter 1) the genetic basis of evolution of sexual dimorphism. Fisher proposed that sexually selected male display traits originate in both the sexes but are suppressed in the females by modifier genes, when the trait becomes deleterious to females. Thus, sexually antagonistic selection on a trait and sex-specific gene expression can lead to the evolution of sexual dimorphism. Tusk is sexually monomorphic in the probocideans that are ancestral to both the African (Loxodonta africana) and Asian elephant (Elephas maximus). Tusk continues to remain monomorphic in the African elephant but has become sexually dimorphic in the Asian elephant. Tusk, therefore could be a sexually selected male trait that evolved according to the Fisherian model. Intriguingly, tuskless males occur at very high frequencies in some Asian elephant populations. The tusked and tuskless male morphs could be alternate male mating strategies, occurring at evolutionarily stable frequencies. Alternatively, the observed male tusk dimorphism, could be a consequence of artificial selection against tusked individuals, due to selective harvest of tusked males. Furthermore, male African elephants are more intensely poached for ivory than female elephants. Yet the frequency of tuskless individuals has increased more rapidly among females than in males. In essence, sexual dimorphism could be evolving among such poached populations. Is such rapid, contemporary evolution of sexual dimorphism, possible through the Fisherian modifier gene mechanism? A 2-loci genetic model (with X-linked trait gene and an autosomal modifier gene) (Rice 1984), a slight variant of the model (with X-linked modifier gene, and an autosomal trait gene) and an entirely autosomal model, were analyzed for the rate of evolution of sexual dimorphism, under different selection pressures for tusk possession. Negative frequency dependent selection was introduced into the model of tusk evolution in accordance with Gadgil’s model for the evolution of male dimorphism as consequence of sexual selection (Gadgil 1972). In two of the 2-loci models (in which tusk gene in autosomal), tusklessness evolved much more rapidly in females than in males, under equal negative selection pressures. The models predict several combinations of time-lines and negative selection pressures for effecting a particular change in the frequency of tusklessness. Model predictions were com-pared with observed changes in the frequency of female tusklessness, in one South Ugandan, African elephant population (∼2% to 10% in 5 to 9 generations) and male tusklessness (∼5% to 50% in 25 to 40 generations) in one north eastern Indian, Asian elephant population. The models predict strong selection pressures of 30% to 50% reduction in fitness, that can effect an 8% increase in tusklessness, in the African elephant population, within time-lines of 9 to 5 generations (∼225 to 125 years) respectively. For the male Asian elephants, natural selection against tusked males on an already sexually dimorphic population, must have been in operation and shifted the population to 5% male tusklessness. The models predict that artificial selection with 20 to 30% fitness cost to tusked males, operating for 40 to 25 generations (∼1000 to 600 years) respectively, can further shift the population from ∼5% to ∼50% tusklessness. Asian elephant populations may already have been in a transient phase of evolution, tending towards tusklessness, with recent artificial selection hastening the process. The two major pre-dictions from this modeling exercise are (1) artificial selection could have played a significant role in the evolution of male tusk dimorphism in the Asian elephant (2) a lack of or very mild current sexual selection on tusks in the male Asian elephant. Both these predictions may be empirically verified. Chapters 2 and 3 are attempts at empirical verification of prediction (1) and Chapters 4 and 5 of prediction (2). From historical references to elephant harvest in Assam, we do know that artificial selection has been in operation, but whether it has played a major role in causing male tusk dimorphism needs to be established. It may be possible to detect signatures of significant past harvest from current demographic structure of an elephant population. Sustained biased harvesting of a particular sex and or age class from an animal population alters the sex ratio and age structure (relative proportion of individuals in each age and sex class) of a population considerably (Sukumar 1989). It may be possible to back infer the harvest scenario by studying the deviation of current age and sex ratios from natural age and sex ratios. In Chapter 2, I explored models of population dynamics under different harvest regimes and its effect on age and sex ratios. I described a method to infer unknown harvest rates and numbers from age and sex ratios, namely, adult female to male ratio, male old-adult to young-adult ratio, and proportion of adult males in the population using Jensen’s(2000) 2-sex, density-dependent Leslie matrix model. The specific combination of male and female harvest rates and numbers can be deter-mined from the history of harvest and an estimate of population size. I validated this model with published data on age and sex ratios of one Asian and African elephant population with fairly reliable data on elephant harvest as well. In Chapter 3, I applied this model to the demographic data that I collected from a wild Asian elephant population in Kaziranga National Park, Assam, India (where more than 50% of the adult males are tuskless). Male polymorphism of sexually-selected male traits occur at stable frequencies in populations of several species. The different male morphs of the trait are hypothesized to be alternate male mating strategies with equal life time reproductive fitness. Male Asian elephants of Kaziranga National Park, Assam are dimorphic with respect to tusk possession: ∼50% of the males are tuskless (and are locally called makhnas). Makhnas could be trading tusk for either longevity, larger body size, testicular volume and or duration of musth as alternate mating strategies. On the other hand makhnas may have increased to a very high frequency primarily due to selective removal (captures for domestication and hunting for ivory) of tusked males from the population for centuries. The aim of Chapter 3 was to examine the role of artificial selection in the evolution of makhnas. Prolonged male-biased harvest(removal from the population) is bound to alter the demographic structure of the population and leave a signature of the intensity and type of harvest on the residual population structure. The Kaziranga elephant population was considered as representative of elephant populations of north east India; A harvest modeling approach (described and validated in Chapter 2) was used to infer unknown harvest of elephants from demographic parameters estimated by sampling this elephant population during 458 field days in the dry season months of 2008–2011. The Kaziranga elephant population appears to have been harvested approximately for the past 700 to 1000 years with adult tusked males being harvested at approximately twice the rate of adult tuskless males, adult females and their immature offspring of both the sexes. The currently observed high frequency of tuskless males in Kaziranga therefore, may be a consequence of sustained artificial selection against tusked males for several centuries. The previous two Chapters have only examined some mechanisms for the loss of tusks in elephants. I proceeded to examine the possibility of evolution of tusks through Darwin’s mechanisms of male-male competition for mates and female mate choice. Elephant tusks are cited as an example of a male trait that has evolved as a weapon in male-male combats. In Chapter 4 I examined the role of tusks in establishing dominance along with two other known male–male signals, namely, body size and musth (a temporary physiologically heightened sexual state) in an Asian elephant population in northeastern India with equal proportions of tusked and tuskless males. I observed 116 agonistic interactions with clear dominance outcomes between adult (>15 years) males during 458 field days in the dry season months of 2008–2011. A generalized linear mixed-effects model was used to predict the probability of winning as a function of body size, tusk possession and musth status relative to the opponent. A hierarchy of the three male–male signals emerged from this analysis, with musth overriding body size and body size overriding tusk possession. In this elephant population tusk possession thus played a relatively minor role in male–male competition. An important implication of musth and body size being stronger determinants of dominance than tusk possession is that it could facilitate rapid evolution of tuskless males in the population under artificial selection against tusked individuals, which are poached for ivory. If not a weapon, tusks could be a male ornament that female elephants find attractive. I explored the interplay of the three male traits (body size, musth and tusk), male mating strategies and female mate choice in Chapter 5. In some species males obtain mating opportunities by harassment of females. Given the striking size difference between an adult male and female elephant, with males weighing at least 30% more than females, male coercion of females to mate is a possibility. A detailed study of the courtship behavior revealed that overt male harassment of females is rare and the ability of a male to mount and stay mounted on a female for copulation is under female control. Therefore female Asian elephants can exercise choice to mate but this is subtly different from exercising mate choice itself. Age-related male mating strategy (reported for the first time in the Asian elephant) exists in the Kaziranga elephant population and this strategy limits the ability of females to exercise choice. Young males (<25 years) predominantly show a sneak mating strategy. Middle-aged males (25–40 years), when in musth, mate–guarded oestrous females from sneakers and attempted mating but sometimes resorted to sneak mating when out of musth. Old males (> 40 years) attempted mating only during their musth phase and were seldom sneakers. Large/musth males received positive responses from estrous females towards courtship attempts significantly more often than did small/non–musth males. Tusked non–musth males attempted courtship significantly more often than did their tuskless peers, and had a higher probability of receiving positive responses than did tuskless males. A positive response, however, may not translate into mating because of mate–guarding by the dominant male. Females permitted large/musth males to stay mounted significantly longer than small/non-musth males. Musth and large body size may be signals of male fertility. Female mate choice in elephants thus seems primarily for traits that signal direct benefits of assurance of conception. Tusked males may attain sexual maturity faster than tuskless males. Therefore it is worth exploring if tusks function as signals of male fertility when males are young (15 to 25 years); this may be possible through hormonal and behavioral profiling of young tusked and tuskless males from 10 to 20 years of age. Overall all musth and body size appear to play a larger role in enhancing male mating success than tusks. Tusked males appear to have a weak sexual selection advantage (male-male domi-nance and female preference) over their tuskless peers, only in the young age class (15 to 25 years) in this population. Males in this age age class, seldom come into musth that would over-ride tusk as a signal of male dominance. Current sexual selection on tusks in this population, appeared to be insignificant and this may be verified through genetic analysis of paternity success. An important implication of musth and body size being stronger determinants of mating success than tusk possession is that, it could facilitate rapid evolution of tuskless males in the population under artificial selection against tusked individuals, even in a slow breeder such as the elephant. Musth may have evolved much later than tusks in elephants, therefore it is possible that tusks evolved under sexual selection before musth evolved. However, body size, in mammals in gen-eral appear to be under both natural and sexual selection. Gould has shown that the absurdly large and palmate antlers of the extinct Irish elk, scales allometrically with body size (Gould & Lewontin 1979). Phylogenetic studies of elephant evolutionary radiation indicate a general trends towards increase in body-size with size reduction and tendency towards dwarfism occurring only in island habitats (Palombo 2001). Tusk development, which is essentially tooth development may be closely linked to cranium development. Cranium development in turn may be linked to body size through allometric scaling laws. If so, any selection on body size is bound to act on tusk size. I propose that the evolution of elaborate tusks seen in elephants is primarily due to natural and or sexual selection acting on body size, and tusk just hitched a ride with body size. Tusks may be maintained in spite of tuskless males occurring in the population only because of a rather weak sexual selection advantage to tusk possession in contests in which males are symmetrical with respect to body size and musth status.

Thesis (MScConEcol)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: In this thesis I explore how elephant movements are impacted by human activity within the context of the proposed Kavango-Zambezi Transfrontier Conservation Area (KAZA TFCA) in southern Africa. Being a wide-ranging species, the movements of elephants could be an excellent indicator as to the success of TFCAs in supporting species persistence in an anthropogenic matrix. Understanding which areas beyond protected area boundaries are of heightened conservation importance can provide managers and governments with insights for the management of the elephant population of KAZA TFCA, and assist managers and governments in prioritising conservation efforts. Satellite radio collar data were used to model long-range elephant movement within KAZA TFCA. Movement was compared between land use types (protected and nonprotected areas). Home ranges, core areas and seasonal ranges were calculated from collar data. Core and non-core areas were tested for significant differences in distance to settlements, rivers, protected area, AFRI and elevation as these spatial and ecological variables are believed to play a role in elephant habitat selection. Short-range elephant movements were examined in a heterogeneous, patchy landscape mosaic of settlements and agricultural fields, remnant forest patches, and secondary forests which were surrounded on three sides by protected areas. Elephant penetration of the anthropogenic matrix through the use of pathways was explored through ground-based surveys, and the impact of pathways use on human-elephant conflict calculated. I found that elephant behavioural plasticity allows for their persistence in a spatially heterogeneous landscape. Elephants, especially bulls, penetrated the landscape matrix beyond protected area boundaries. Land use planning initiatives are needed to identify and protect reachable core zones/stepping stones of quality habitat outside of protected areas, particularly in riparian zones. Differing male and female ranging behaviour within the landscape matrix may require separate land use management strategies: bulls travelled at night in non-protected areas at speeds that were four times faster than in protected areas, and made use of core zones necessary for species persistence in a fragmented landscape. A habitat corridor in the Zambian West Zambezi Game Management Area was identified. I found that during short range movements in heterogeneous environments, elephants made use of pathways. Pathways may facilitate penetration of the anthropogenic matrix and optimize foraging strategies by connecting predictable resources, such as crop fields, with landscape features such as preferred shelter/ resting areas, crossing points at roads and preferred drinking spots. Pathways were found to be the only significant spatial variable in crop-raiding. Elephants foraged randomly while in homogenous crop patches, but when travelling through a heterogeneous environment (entering or leaving agricultural locales), movement was directional and non-random. Lastly I suggest that crop attractiveness may be enhanced by water availability. Results indicated that at both the landscape and the regional scale, repeat elephant movements to core zones and along elephant pathways provided landscape ecological variables that need to be considered by conservation managers in land use planning. In addition, research on spatial awareness and navigational capabilities with regards to pathway use by elephants should be encouraged, as this research topic has been largely unexplored in the scientific literature. / AFRIKAANSE OPSOMMING: In hierdie tesis verken ek die moontlike impak van menslike aktiwiteite op olifant beweging binne die beoogde Kavango-Zambezi Oorgrens Bewaringsarea (KAZA TFCA) in suider-Afrika. Olifante is wydlopende spesies, en dus kan hul ruimtelike strekking ‘n uitstekende indikator wees van die sukses van oorgrens bewaringsareas in terme van die ondersteuning wat dié programme bied om spesies se volharding in ‘n antropogeniese matriks te verseker. Besturrders en regerings kan insig verkry deur te besef watter areas buiten die in beskermde gebiede, van verhoogde bewarings belang in KAZA TFCA is. Hierdie insig verleen ook bystand aan bestuurders en regerings met die prioritisering van bewarings inisiatiewe. Satelliet-radio nekband data was gebruik om olifante se langtermyn ruimtelike beweging binne die KAZA TFCA te modelleer. Olifant beweging was vergelyk tussen verskillende grondgebruik tipes (beskermde en onbeskermde areas). Tuistestrekking, kern areas asook seisoenale strekking was bereken vanaf nekband data. Kern en nie-kern areas was getoets vir betekenisvolle verskille in afstand vanaf nedersettings, riviere, berskermde gebiede, AFRI, en hoogte bo seevlak, omdat hierdie ruimtelike en ekologiese veranderlikes ‘n belangrike rol mag speel in olifant habitat seleksie. Kortafstand olifant bewegings was bestudeer in ‘n heterogene, gelapte landskap mosaïek van nedersettings en landbougrond, oorblywende woudareas, en sekondêre woude waarvan drie sye grens aan bekermde areas. Olifant indringing binne die antropogeniese matriks deur die gebruik van weë/toegangsweë was verken deur middel van landgebaseerde opnames, waarvolgens die impak van olifante se gebruik van hierdie paaie op mens-olifant konflik bereken kon word. My bevindinge wys dat plastisiteit in olifant gedrag dra by tot hul voortbestaan in ‘n ruimtelik heterogene landskap. Olifante, maar meer spesifiek olifantbulle, penetreer wel die landskap matriks buite beskermde area grense. Grondgebruik beplannings inisiatiewe word dus benodig om bereikbare kern areas van kwaliteit habitat buite beskermde areas te identifiseer en te beskerm – veral in rivieroewer sones. Verskille in bul en koei ruimtelike strekking gedrag binne die landskap matriks, mag afsonderlike bestuur stratgieë vereis: bv. bulle beweeg vier keer vinniger in die aand in onbeskermde areas teenoor in beskermde gebiede, daarby maak hulle ook gebruik van kern areas wat kardinaal is vir die voortbestaan van spesies in gefragmenteerde landskappe. ‘n Habitat deurgang was geïdentifiseer in die Zambiese Wes-Zambesie Wildbestuurarea. Die studie het gevind dat olifante gedurende kortafstand bewegings in heterogene omgewings gebruik maak toegangsweë. Toegangsweë mag penetrasie van die antropogeniese matriks fasiliteer, en verleen ook dat olifant weidingstrategieë die optimum bereik deur voorspelbare hulpbronne soos gewaslanderye te konnekteer met landskap eienskappe soos voorrang skuiling/rusareas, kruisingspunte by paaie, asook voorrang drinkplekke. Toegangsweë was gevind om die enigste betekenisvolle ruimtelike veranderlike in gewasstrooptogte te wees. Olifante wei lukraak in homogene gewaslanderye, maar in teenstelling, wanneer hulle deur ‘n heterogene omgewing beweeg het (binnegang of uittog uit landbou lokaliteite) was die beweging gerig. Laastens, die studie stelvoor dat gewas aantreklikheid verhoog kan word deur water beskikbaarheid. Resultate dui aan dat by beide die landskap- en streekskaal verskaf herhaalde olifant beweging na kern areas en langs olifants togangsweë, landskap ekologiese veranderlikes wat in ag geneem moet word deur bewaringsbestuurders tydens grondgebruik beplanning. Bykomend, navorsing op die ruimtelike bewustheid en navigasie vermoëns van savannah olifante met betrekking tot die gebruik van toegangsweë, moet aangemoedig word aangesien hierdie onderwerp grootliks onverken is in wetenskaplike literatuur.

La grande extension méridienne et la faible profondeur du plateau de Kerguelen en font un obstacle majeur à l'écoulement zonal du Courant Circumpolaire Antarctique (CCA) dans le secteur indien de l'océan austral. Tandis que la majorité du transport du CCA est dévié au nord des îles Kerguelen, le reste (50 x 10 m3 s-1) doit passer plus au sud, probablement par les passages profonds du Fawn Trough (56°S, 77°E, 2650 m) et du Princess Elizabeth Trough (64°S, 82°E, 3650 m). Pourtant, le détail de la circulation autour du plateau est longtemps resté méconnu, en raison des difficultés à récolter des données dans cette région éloignée de toute route commerciale, d'un climat particulièrement rude et de la présence de la banquise recouvrant la moitié du plateau en hiver. L'objectif de cette thèse est d'améliorer notre connaissance de la circulation moyenne autour du plateau de Kerguelen. Pour cela, un large éventail d'outils allant de l'analyse d'observations récentes à l'utilisation de modèles numériques de circulation a été utilisé. Les données obtenues à l'aide d'éléphants de mer instrumentés sont présentées en détail. Une procédure de calibration et de validation de ces profils hydrologiques est proposée. Ce jeu de données, constitué d'un grand nombre de sections à haute résolution spatiale, est ensuite combiné avec d'autres observations plus conventionnelles (in situ et satellites) pour construire un nouveau schéma de circulation dans la région. L'existence d'un courant intense traversant le passage du Fawn Trough est alors mise en évidence. Les observations directes du courant du Fawn Trough pendant la campagne récente TRACK (resp.: Y.-H. Park) confirment l'importance de ce courant, qui concentre plus de 40 x 10 m3 s-1, soit 30 % du transport total du CCA. La connaissance de la circulation développée à partir des observations est ensuite utilisée pour valider une simulation au 1/4° de résolution. A l'aide de tests de sensibilité sur une configuration régionale de l'Océan Indien Sud, l'importance de la bonne représentation des caractéristiques des masses d'eau profonde et de la bathymétrie pour obtenir une simulation réaliste est mise en évidence. Finalement, une analyse dynamique de la simulation est menée, montrant comment la circulation résulte d'une combinaison des effets de la bathymétrie et du vent au travers de la balance de Sverdrup topographique. L'extension méridienne du CCA est maximale dans la région du plateau de Kerguelen, augmentant régionalement le forçage du vent. En permettant le passage de la partie sud du CCA près de la divergence antarctique (entre 60°S et 65°S), où le pompage d'Ekman est très intense, le plateau de Kerguelen pourrait favoriser indirectement l'accélération du CCA.

Mopane (Colophospermum mopane) trees are browsed upon by two key species, namely mopane caterpillars (Imbrasia belina) and African elephants (Loxodonta africana), which each inflict a different type of damage while feeding, namely defoliation (leaf removal) and pruning (branch and/or stem breakage). Damage type can have a significant influence on plant responses, and these induced changes in morphological and chemical characteristics of regrowth can influence the subsequent feeding behaviour by each species. The objective of this study was therefore partly to investigate the differential effect of defoliation by mopane caterpillars and pruning by elephants on mopane trees, and then to investigate whether these two taxonomically different species interact through their shared food resource, by looking specifically at the effect of elephant utilisation of mopane on mopane caterpillar abundance. To determine the comparative effect of each browsing type, mopane trees were subjected to simulated mopane caterpillar or elephant utilisation treatments, at various frequencies and times within the year. Regrowth characteristics were then measured on treatment and control trees, as well as on naturally utilised and unutilised trees. Reproductive investment was also recorded on naturally utilised and unutilised trees. Additionally, the impact of mopane caterpillar defoliation and elephant pruning on plant stress was investigated by measuring the level of fluctuating asymmetry (FA) in leaves. Then, to determine whether there is an interaction between elephants and mopane caterpillars, mopane caterpillar egg mass abundance in areas of high elephant impact was compared to that in areas of low elephant impact. Firstly, however, in areas without elephant damage, those tree characteristics determining host tree preference by ovipositing mopane moths were identified. From this, an understanding of how elephant utilisation may influence mopane caterpillar abundance could therefore be gained. Defoliation and pruning had a significant different effect on mopane regrowth responses. Shoot and leaf length were significantly longer on pruned trees than control trees, for both naturally utilised and simulated elephant treatment trees, while there was no difference in shoot density. Defoliation, however, resulted in shorter shoots and leaves, particularly on naturally defoliated trees, which also had leaves of a higher nutritional value (tannin:protein ratio and total polyphenolic content) than control trees. A similar increase in leaf nutritional value was recorded in areas of high elephant impact in the Kruger National Park, but not after simulated or natural elephant damage in Venetia, where natural elephant utilization was less intense. Time since damage (i.e. first versus second flush) had a significant influence on regrowth after pruning, as shoot and leaf length were significantly longer on trees flushing for the first time, while within-season timing of damage was important for defoliation, as late-season defoliation had a greater negative impact than mid-season defoliation. Late-season defoliation also had a negative effect on leaf carriage into the dry season, while pruning appeared to aid leaf retention. Reproductive investment was found to be unaffected by mopane caterpillar defoliation or elephant pruning, as mean pod density and pod mass on utilised trees was no different to unutilised trees. Defoliation also had no influence on a plant’s likelihood of flowering that same season, with flowering being determined more by tree height. Unlike pod production, however, mean leaf density was significantly reduced in the regrowth of defoliated trees, presumably due to the use of stored resources for reproduction prior to the onset of regrowth. Neither simulated nor natural defoliation by mopane caterpillars and pruning by elephants was found to affect the level of leaf FA in mopane trees, even though the degree of damage inflicted on trees was considerably higher than in studies on other species where increases in FA were observed. Mopane therefore appears to be extremely tolerant of herbivory in comparison to other species. A positive relationship between leaf nutritional value (higher protein and lower tannin and polyphenolic content) and FA was detected, but only when trees from all study areas (i.e. a wide range of environmental conditions) were considered simultaneously. Environmental conditions, rather than herbivory, therefore appear to have a greater stressing affect on mopane. In the absence of heavy elephant utilisation of mopane trees, tree size, rather than shoot length, leaf length, leaf FA or leaf nutritional value, was found to have the greatest influence on oviposition behaviour of mopane moths. Ovipositing moths showed a preference for the tall riverine habitat over the shorter woodland and scrub mopane. This preference for large trees was, however, not evident at the individual tree level, as even though egg mass number per tree was positively related to tree height, large trees were not utilised more than expected according to the available canopy volume in each size class (resource availability). Heavy elephant utilisation of mopane had a negative impact on the density of tall trees within an area, due to branch and stem breakage while feeding. Unsurprisingly then, mopane caterpillar egg mass abundance was also significantly reduced in these areas, even though the nutritional value of leaves was higher than in non-elephant impacted areas. Elephants therefore appear to have a negative effect on mopane caterpillar abundance, primarily due to their negative impact on the density of tall mopane trees. This megaherbivore and invertebrate do therefore interact through their shared food resource, mopane trees. / Thesis (PhD (Zoology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted

With the advent of new applications such as Cloud Computing, Blockchain, Big Data, and Machine Learning, modern data center network (DCN) architecture has been evolving to meet numerous challenging requirements such as scalability, agility, energy efficiency, and high performance. Among the new applications ones are expediting the convergence of high-performance computing and Data Centers. This convergence has prompted research into a single, converged data center architecture that unites computing, storage, and interconnect network in a synthetic system designed to reduce the total cost of ownership and result in greater efficiency and productivity. The interconnect network is a critical aspect of Data Centers, as it sets performance bounds and determines most of the total cost of ownership. The design of an interconnect network consists of three factors: topology, routing, and congestion control, and this thesis aims to satisfy the above challenging requirements. To address the challenges noted above, the communication patterns for emerging applications are investigated, and it is shown that the dynamic and diverse traffic patterns (denoted as *-cast), especially multi-cast, in-cast, broadcast (one-to-all), and all-to-all-cast, play a significant impact in the performance of emerging applications. Inspired by hypermesh topologies, this thesis presents a novel cost-efficient topology for large-scale Data Center Networks (DCNs), which is called HyperOXN. HyperOXN takes advantage of high-radix switch components leveraging state-of-the-art colorless wavelength division multiplexing technologies, effectively supports *-cast traffic, and at the same time meets the demands for high throughput, low latency, and lossless delivery. HyperOXN provides a non-blocking interconnect network with a relatively low overhead-cost. Through theoretical analysis, this thesis studies the topological properties of the proposed HyperOXN and compares it with other different types of interconnect networks such as Fat-Tree, Flattened Butterfly, and Hypercube-like topologies. Passive optical cross-connection networks are used in the HyperOXN topology, enabling economical, power-efficient, and reliable communication within DCNs. It is shown that HyperOXN outperforms a comparable Fat-Tree topology in cost, throughput, power consumption and cabling under a variety of workload conditions. A HyperOXN network provides multiple paths between the source and its destination to obtain high bandwidth and achieve fault tolerance. Inspired by a power-of-two-choices technique, a novel stochastic global congestion-aware load balancing algorithm, which can be used to achieve relatively optimal load balances amongst multiple shared paths is designed. It also guarantees low latency for short-lived mouse flows and high throughput for long-lasting elephant flows. Furthermore, the stability of the flow-scheduling algorithm is formally proven. Experimental results show that the algorithm successfully eliminated the interactions of the elephant and mouse DC flows, and ensured high network bandwidth utilization.

African elephants are ‘keystone’ species with respect to biodiversity conservation in Africa since they maintain habitats that support several animal communities by changing vegetation structure through foraging and by dispersing seeds between landscapes. Elephants are also ‘flagship’ species because, given their impressive size, they can make people sympathetic and stimulate local and international concerns for their protection. Economically, elephants contribute to national revenues as tourists are willing to pay to watch them. Despite all these factors, little is known however about elephant movement and how they utilize resources, especially in miombo-wetland ecosystems. This thesis investigates how elephants utilize resources in a miombo-wetland ecosystem in the Ugalla landscape of Western Tanzania over different protected areas containing different resource users. Using Global Positioning System (GPS) collars fitted to six elephants, it was observed that some elephant families are not confined in one protected area in the Ugalla landscape. Rather, they moved readily between different protected areas. Elephant movements were restricted to areas near the rivers, especially the Ugalla River, during the dry season and were dispersed widely during the wet season. As they move, elephants in the miombo woodlands of Ugalla selected the most abundant woody plants for browsing. Common to many woody plants, the browsed plants were short of mineral nutrients (e.g., sodium, calcium). Elephants obtained additional minerals by eating soils from certain termite mounds. Soils from termite mounds are richer in mineral elements (e.g., sodium, calcium, iron) compared to soils from the surrounding flood plain or compared to the browsed plants. However, the recorded termite mounds from which elephants eat soils were not evenly distributed in the landscape but confined mainly to the flood plains in the Ugalla Game Reserve. The Ugalla River, which is the main source of water for the elephants and other animals and also supports fishing activities by the local people in Ugalla during the dry seasons, is infested by the water hyacinth (Eichhornia crassipes). Such infestation potentially limits access to these precious surface water supplies. In addition at the regional level, the Ugalla River is among the major rivers that flow into the Lake Tanganyika which is shared by the countries of Tanzania, Burundi, Democratic Republic of Congo and Zambia. Thus, the spread of water hyacinth if left unchecked threatens to impact Lake Tanganyika, affecting many countries and ecosystem services. This thesis highlights that sustainable conservation of biodiversity in different protected areas in the Ugalla landscape requires an integrated management approach that will embrace conservation of different interrelated landscape resources required by both wildlife and the rural poor populations for their livelihoods. Regular coordinated wildlife anti-poaching patrols should be initiated across the entire Ugalla landscape because the elephants, among other wildlife, utilize different protected areas in Ugalla. Local communities should also be engaged in conservation initiatives (e.g., controlling the spread of the water hyacinth) as these directly impact local livelihoods. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.</p> / INTEGRATED NATURAL RESOURCES MANAGEMENT

Troupers: Essays in Three Rings is a collection of fourteen essays focused mainly on variety entertainers (including the author). It leads the reader through a menagerie of the author's own enthusiasms--from clowning and circus elephants, to hot jazz and the ukulele. While the primary occupation of the "troupers"spotlighted here has always been to delight audiences, many of them--both human and animal--could not escape the hardscrabble, the sundered relations, the violence of everyday life. The author tells the stories of these "troupers" here, stories that reveal both their suffering and their refusal to suffer.

“Conflicted” succinctly describes Ernest Hemingway. He had a strong desire to make his parents proud of him but this was in constant conflict with his need to tell a story, warts and all. Of particular importance is his relationship with his mother and the crippling effect it has on his relationships with women. Hemingway’s life becomes a series of dysfunctional relationships that fail to meet his needs, leaving him perpetually searching for the right woman. Kert posits that Hemingway’s contempt for women is related to his inability to make the transition from lover to husband, fueled by Hemingway’s belief that his father surrendered his manhood to Grace Hemingway. Ernest, haunted by his parents’ relationship continues to associate negative connotations with the term “husband,” leaving Hemingway in constant fear of becoming his father, poisoning his marriages, and coloring the relationships Hemingway depicts in his short stories. Evident across the arc of Hemingway’s short stories is an evolution in his skill as a writer, but also in the development of his female characters. Over his career, Hemingway develops a female voice that rings true, and he skillfully uses it to portray female characters who are evolving into strong self-reliant women. In these stories, there is a gradual shift in the dynamics of the relationships as Hemingway’s fictional women struggle to climb from under their man’s domination. Yet, these strong self-reliant women are not fully accepted by Hemingway’s male characters, leaving a palpable tension between Hemingway’s fictional men and women. This tension can be attributed to Hemingway’s ongoing love/hate relationship between himself and the self-reliant women in his life. Hemingway never recovers from the emotional damage inflicted by his mother, evident in his personal life and in the dysfunctional relationships in his short stories. He remains vigilant and is concerned that he will end up like his father and be controlled by a domineering bitch. However, Hemingway exerts so much control in his relationships and becomes a version of his mother as he dominates his significant others. In his life, he transitions from an angry resentful child-man to a young husband, a reluctant parent, a ladies’ man, and an adventurer. Likewise, his perception and portrayal of women in his short stories keeps pace with his personal experiences. These female characters sometimes reflect the women in his life and sometimes reflect Hemingway’s insecurities as a man, and often a seamless melding of both.