As top predators birds of prey are excellent bioindicators for any environment. The community is divided into four orders (Cathartiformes, Accipitriformes, Falconiformes and Strigiformes), presenting great diversity of species. Many disappear with ecosystems changes, and habitat loss is the main cause of extinctions. South America is the continent with the greatest richness of raptors, and only in Brazil 98 species have been recorded. The degradation of some biomas, however, has caused the local extinction of raptors with great ecological requirements. The Atlantic Forest, which has bit more than 10% of its forest cover still preserved, has suffered along almost its entire length the loss of some species which are very sensible to human impacts, such as Harpia harpyja and Morphnus guianensis. In the northwestern region of Rio Grande do Sul, forest loss was significant and with it much of the fauna that originally inhabited the area. Given protected area establishments and connection with the extensive forests of Misiones (Argentina), some places still have many raptors rare or regionally endangered. It is the case of Turvo State Park ( Parque Estadual do Turvo - PET) and the Indigenous Land of Guarita ( Terra Indígena do Guarita - TIG), which are distant only 15 km, in a fragmented landscape, with forest patches under different attributes and different mosaics. In this context we sought to identify how the community of raptors responds to the factors presented in the fragments under different conditions. Through specific methodology for diurnal raptors we also sampled the situation of the community in TIG. Fourteen fragments and seven points were sampled in the TIG. The data of TIG were compared to those found in a survey with the same methodology in PET. The results showed the only factor that influences the richness and the frequency of occurrence of raptors in the fragments is the area. Factors as isolation (distance between a fragment and PET or TIG), quantity of forest cover in the mosaic and the form of the fragment were not significant. This is probably given by the great capacity of dispersion of birds of prey, differing from others groups of fauna. The raptors community of TIG presented very similar results to that found in PET. We emphasize some inedited and conservation relevance records for TIG, such as Sarcoramphus papa, Leptodon cayanensis and Spizaetus melanoleucus. Even if TIG is in a context less favorable to conservation when compared to PET, our results shows the importance of the indigenous area for the conservation of the raptors of the region. Once raptors require large areas, are territorial, move easily and have an aversion to disturbances, large fragments offers better conditions of surviving than small ones, especially for species with larger ecological needs. Thus, strategies that involve the preservation of large forest fragments in the northwestern region are fundamental for the preservation of the community of birds of prey of the Alto Uruguay Forest. / Como predadores de topo as aves de rapina são excelentes bioindicadores para qualquer ambiente. A comunidade divide-se em quatro ordens (Cathartiformes, Accipitriformes, Falconiformes e Strigiformes), apresentando grande diversidade de espécies. Muitas desaparecem com a alteração dos ecossistemas, sendo a perda de hábitat a principal causa de extinções. A América do Sul é o continente com maior riqueza de rapinantes, e só no Brasil já foram registradas 98 espécies. A degradação de alguns biomas, no entanto, tem ocasionado a extinção local de rapinantes com grandes requerimentos ecológicos. A Mata Atlântica, que tem pouco mais de 10% de sua cobertura florestal ainda preservada, tem sofrido ao longo de quase toda sua extensão a perda de algumas espécies que são bastante sensíveis a impactos antrópicos, como Harpia harpyja e Morphnus guianensis. Na região noroeste do Rio Grande do Sul a perda de florestas foi significativa e com ela grande parte da fauna que originalmente habitava a área. Dado o estabelecimento de áreas protegidas e a conexão com as extensas florestas de Misiones (Argentina), alguns locais ainda possuem vários rapinantes raros ou regionalmente ameaçados de extinção. É o caso do Parque Estadual do Turvo (PET) e da Terra Indígena do Guarita (TIG), que distam-se apenas 15 km numa paisagem fragmentada com remanescentes florestais sob diferentes atributos e em diferentes mosaicos. Nesse contexto procuramos identificar como a comunidade de aves de rapina responde aos fatores apresentados através de fragmentos em diferentes condições. Através de metodologia específica para rapinantes diurnos amostramos também a situação da comunidade de rapinantes na TIG. Foram amostrados 14 fragmentos e sete pontos na TIG. Os dados da TIG foram comparados àqueles encontrados em um estudo usando a mesma metodologia no PET. Os resultados demonstram que o único fator que influencia na riqueza e frequência de ocorrência de rapinantes nos fragmentos é a área. Fatores como isolamento (distancia entre um fragmento e o PET ou a TIG), quantidade de cobertura florestal no mosaico e forma do fragmento não foram significativos. Isso provavelmente se dá em função da grande capacidade dispersiva das aves de rapina, diferindo de outros grupos da fauna. A comunidade de aves de rapina da TIG apresentou-se muito semelhante àquela encontrada no PET. Destacamos alguns registros inéditos e de relevância conservacionista para a TIG, tais como Sarcoramphus papa, Leptodon cayanensis e Spizaetus melanoleucus. Apesar da TIG estar em um contexto menos favorável à conservação quando comparada ao PET, nossos resultados demonstram a importância da área indígena para a conservação dos rapinantes da região. Uma vez que rapinantes necessitam de grandes áreas, são territorialistas, deslocam-se com facilidade e apresentam aversão a perturbações, fragmentos grandes oferecem melhores condições de sobrevivência do que os pequenos, especialmente para as espécies com maiores necessidades ecológicas. Assim, estratégias que envolvam a preservação de grandes remanescentes florestais na região noroeste são fundamentais para a preservação da comunidade de aves de rapina da Mata do Alto Uruguai.

Sexual reproduction in Porites divaricata (Le Sueur, 1820) was studied over a one year period (August, 2012 to August, 2013) in a shallow water (~2m depth) carbonate bank (also described as marginal) habitat at Rodriguez Key, a small island located 1.44 km off the east coast of Key Largo. Porites divaricata is a brooding, gonochoric species with peak reproductive output (planula release) occurring in March and at least a smaller event in May. This species showed an overall female to male sex ratio of 3.5:1. However, during peak reproduction, the sex ratio was 1.2:1. Spawning (sperm release) most likely occurred in late February when 78% of all oocytes and 84% of all spermaries were in stage IV of development. The largest output of stage IV eggs (n=164) occurred at this time, and these oocytes also had the second largest average individual oocyte volume (3.34x10-3 mm3, n = 79) compared to those from other sample dates. The largest average egg volume (3.79x10-3 mm3, n = 8) occurred in May, but with fewer eggs present (n=13). Population surveys showed P. divaricata densities of 7.4 and 17.7 colonies m-² at Site 1 and 2, respectively. Temperature data documented that SSTs were highly variable in the seagrass/coral habitat at site 2 (primary collection site), ranging from 13.1 to 34.9°C, with an average temperature of 25.9°C. Corals at Rodriquez Key are exposed to temperatures much higher (+3.8°C) during the summer and much lower (-8.2°C) in winter compared to corals living at a nearby bank reef (Molasses Reef). This is the first comprehensive reproductive study performed on Porites divaricata and may provide valuable information to the ongoing debate concerning the taxonomic relationships among P. divaricata, P. porites, and P. furcata.

In spatially structured populations, distributional dynamics are driven by the quantity, connectivity and quality of habitat. Because these drivers are rarely measured directly and simultaneously at relevant scales, information on their relative importance remains unclear. I assessed the influence of both direct and indirect measures of local habitat quality, and of landscape habitat amount and connectivity on long-term territory occupancy dynamics of non-migratory pygmy owls. Direct measures of local habitat quality based on territory-specific reproductive output had greater effects on distribution than landscape factors, but only when spatio-temporal fluxes in performance linked to environmental stochasticity and intraspecific competition were considered. When habitat quality was measured indirectly based on habitat structure, however, landscape factors had greater effects. Although all landscape factors were important, measures of landscape connectivity that were uncorrelated with habitat amount and based on attributes of matrix structure and habitat configuration that influence dispersal movements had greater effects than habitat effective area (amount weighted by quality). Moreover, the influence of connectivity (but not habitat effective area) depended on local habitat quality. Such results suggest the relative importance of local habitat quality in driving distribution has been underestimated and that conservation strategies should vary spatially depending on both local and landscape contexts.

Cette thèse a pour objectif de comprendre les mécanismes physiques régissant la formation de capsules submillimétriques à coeur aqueux possédant une membrane fine d'hydrogel et ainsi de mieux maitriser ce procédé. Des bigouttes sont d'abord formées dans l'air par fragmentation d'un jet cylindrique composé d'un coeur aqueux enveloppé par une solution d'alginate. La coque est ensuite gélifiée après immersion dans une solution de calcium. L'étude du co-Écoulement au sein de l'injecteur a montré l'existence d'une instabilité élastique qui est amplifiée en présence de cations, du fait du caractère polyélectrolyte de l'alginate. Nous avons montré que cette instabilité était à l'origine d'un battement du jet composé en sortie d'extrusion. En provoquant un décentrage du coeur, l'instabilité induit une relaxation asymétrique du profil de vitesse, ce qui crée un couple qui courbe le jet. Nous avons mis en évidence cet effet en produisant des jets courbés à partir d'une pointe biseautée. La fragmentation du jet est ensuite contrôlée par une perturbation harmonique des débits d'injection. Nous observons une décroissance de la vitesse d'onde à la surface du jet pilotée par la tension de surface. La viscosité élevée des solutions d'alginate entraine une amplification de fluctuations de cette vitesse donnant lieu à des coalescences au sein du jet. L'ajout de tensioactifs peut exacerber cet effet en induisant une tension de surface dynamique à la surface du jet. Finalement, nous parvenons à produire des capsules submillimétriques de taille contrôlée, monodisperses, possédant une membrane fine, avec un taux d'encapsulation supérieur à 99%. Ces capsules trouvent des applications dans le domaine des biotechnologies comme nouvel outil pour la culture cellulaire. / The purpose of this work is to understand physical mechanisms that control the formation of aqueous-Core submillimetric capsules with a thin hydrogel membrane. This comprehension will allow a better control of the process. Compound drops are first formed in the air by the break-Up of a cylindrical jet composed of an aqueous core surrounded by an alginate solution. The shell is then solidified after immersion in a gelling calcium solution. The study of the co-Flow inside the injector showed the existence of an elastic instability which is amplified in the presence of cations, due to the polyelectrolyte property of alginate. We showed that this instability causes the flapping of the compound jet out of the injector. The instability induces a displacement of the core fluid position which leads to an asymmetric velocity relaxation that creates a torque and finally bends the jet. We produced curved jets with a beveled capillary to demonstrate this effect. The jet break-Up is controlled by a harmonic perturbation of the injection flow rates. We measured a decrease of the wave speed on the jet surface which is controlled by the surface tension. The alginate solution high viscosity causes an amplification of speed fluctuations that induces coalescence inside the jet. This amplification is enhanced by the addition of surfactants which create a dynamic surface tension at the jet interface. Finally, we managed to produce submillimetric and monodisperse capsules with a thin membrane, an encapsulation yield above 99% and a size that we can tune. These capsules can be used in biotechnology applications as a new tool for cell culture.

The aim of this research study is to investigate different practical ways in which fractal geometry and self-similarity can be applied to art music, with reference to music composition and analysis. This specific topic was chosen because there are many misconceptions in the field of fractal and self-similar music. Analyses of previous research as well as the music analysis of several compositions from different composers in different genres were the main methods for conducting the research. Although the dissertation restates much of the existing research on the topic, it is (to the researcher‟s knowledge) one of the first academic works that summarises the many different facets of fractal geometry and music. Fractal and self-similar shapes are evident in nature and art dating back to the 16th century, despite the fact that the mathematics behind fractals was only defined in 1975 by the French mathematician, Benoit B. Mandelbrot. Mathematics has been a source of inspiration to composers and musicologists for many centuries and fractal geometry has also infiltrated the works of composers in the past 30 years. The search for fractal and self-similar structures in music composed prior to 1975 may lead to a different perspective on the way in which music is analysed. Basic concepts and prerequisites of fractals were deliberately simplified in this research in order to collect useful information that musicians can use in composition and analysis. These include subjects such as self-similarity, fractal dimensionality and scaling. Fractal shapes with their defining properties were also illustrated because their structures have been likened to those in some music compositions. This research may enable musicians to incorporate mathematical properties of fractal geometry and self-similarity into original compositions. It may also provide new ways to view the use of motifs and themes in the structural analysis of music. / Dissertation (MMus)--University of Pretoria, 2014. / lk2014 / Music / MMus / Unrestricted

A complete, fundamental understanding of the proton must include knowledge of the underlying spin structure. The transversity distribution, h1(x), which describes the transverse spin structure of quarks inside of a transversely polarized proton, is only accessible through channels that couple h1(x) to another chiral odd distribution, such as the Collins fragmentation function (ΔN Dπ/q↑(z,jT)). Significant Collins asymmetries of charged pions have been observed in semi-inclusive deep inelastic scattering (SIDIS) data. These SIDIS asymmetries combined with e+e- process asymmetries have allowed for the extraction of h1(x) and ΔN Dπ/q↑(z,jT). However, the current uncertainties on h1(x) are large compared to the corresponding quark momentum and helicity distributions and reflect the limited statistics and kinematic reach of the available data. In transversely polarized hadronic collisions, Collins asymmetries may be isolated and extracted by measuring the spin dependent azimuthal distributions of charged pions in jets. This thesis will report on the first statistically significant Collins asymmetries extracted from √ s = 200 GeV hadronic collisions using 14 pb-1 of transversely polarized proton collisions at 57% average polarization.

Tissue regeneration in mammals does not occur via the process of dedifferentiation, a process whereby differentiated cells lose their specialized characteristics and revert to a less differentiated state. McGann et al. (2001) showed that mouse C2C12 myotubes treated with newt extract derived from regenerating limbs can re-enter the cell cycle, fragment and proliferate ( a characteristic of muscle dedifferentiation). However, the validity of these studies has been called into question since others have been unable to repeat them. My research attempts to replicate the results of McGann et al, and to carry them further. I examined several strategies for tracking the extract-treated cells and I also repeated the studies in a primary muscle culture system. Furthermore, I examined the effect of the extract on myoblast differentiation. The most effective dedifferentiation assay that I developed involved the microinjection of myotubes with extract and with a GFP plasmid that allowed tracking of the injected cells. Cells were then examined for cell cycle re-entry using BrdU incorporation or Ki-67 immunostaining. In addition, immunocytochemistry and RT-PCR analysis were used to examine the expression or down-regulation of muscle-specific markers. Finally, a preliminary GeneChip analysis was conducted to examine which genes were up or down regulated following extract treatment. The results show that newt extract is able to block the differentiation of confluent myoblasts, resulting in fewer multinucleated, myosin heavy chain expressing myotubes. However, when myoblasts were differentiated into myotubes and subsequently treated with newt extract, the results suggest that cell cycle re-entry and down-regulation of differentiation markers can occur in C2C12 myotubes, but not in primary myotubes. Fragmentation though, was seen in both C2C12 and primary myotubes following treatment or injection with newt extract. Moreover, the fragmented cells appeared to be viable. Transcriptional profiling indicated that newt extract affects genes implicated in cell cycle, transcription, stress, chromatin modification, growth, cell adhesion, extracellular matrix, wound healing and microtubule binding. These findings confirm that mammalian myotubes can be induced to dedifferentiate following treatment with newt extract; however, a differential response was observed between C2C12 and primary muscle cells.

Power management is an active area of research in wireless sensor networks (WSNs). Efficient power management is necessary because WSNs are battery-operated devices that can be deployed in mission-critical applications. From the communications perspective, one main approach to reduce energy is to maximize throughput so the data can be transmitted in a short amount of time. Frame fragmentation techniques aim to achieve higher throughput by reducing retransmissions. Using experiments on a WSN testbed, we show that frame fragmentation helps to reduce energy consumption. We then study and compare recent frame fragmentation schemes to find the most energy-efficient scheme. Our main contribution is to propose a new frame fragmentation scheme that is optimized to be energy efficient, which is originated from the chosen frame fragmentation scheme. This new energy-efficient frame fragmentation protocol is called (Green-Frag). Green-Frag uses an algorithm that gives sensor nodes the ability to transmit data with optimal transmit power and optimal frame structure based on environmental conditions. Green-Frag takes into consideration the channel conditions, interference patterns and level, as well as the distance between sender and receiver. The thesis discusses various design and implementation considerations for Green-Frag. Also, it shows empirical results of comparing Green-Frag with other frame fragmentation protocols in terms of energy efficiency. Green-Frag performance results shows that it is capable of choosing the best transmit according to the channel conditions. Subsequently, Green-Frag achieves the least energy consumption in all environmental conditions.

Using trauma theory, I analyze the disjointed narrative structure of gothic works from 1764-1853 as symptomatic of the traumatic experience. Gothic novels contain multiple structural anomalies, including gaps in experience that indicate psychological wounding, use of the supernatural to violate rational thought, and the inability of witnesses to testify to the traumatic event. These structural abnormalities are the result of trauma that characters within these texts then seek to prevent or repair via detection.

No abstract / Mini Dissertation (LLM)--University of Pretoria, 2019. / Public Law / LLM / Unrestricted