Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 54 for “"colouration"”.
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Plumage colouration, testosterone and reproductive behaviour in the red bishop (Euplectes orix)
Leuchtend rotes Gefieder ist ein häufig auftretendes sekundäres Geschlechtsmerkmal bei den Männchen vieler Vogelarten. Es gibt einige Hypothesen, nach denen carotinoid-basierte Gefiederfärbung mit den unterschiedlichsten Aspekten bzw. Merkmalen eines Männchens wie z.B. väterliche Brutpflege, …
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Colouration evo-devo: the developmental basis of intra-specific variation in cichlid pigmentation
Understanding why and how organisms diversify is a major goal of evolutionary biology. The fields of evolutionary developmental biology, evolutionary ecology, and population genetics have taken complementary approaches to this task, yet a lack of integration between these fields limits our …
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The genomics of adaptive colouration in Hypolimnas butterflies and the wood tiger moth, Arctia plantaginis
… of structural variation in the evolution of wing colouration while also emphasising the repeatability of the genetic basis of adaptive traits.
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Evolution of colour vision in relation to colouration in weaverbirds (Family Ploceidae) and poison dart frogs (Family Dendrobatidae)
Of an organism’s physical traits, colouration is arguably one of the most important for biotic interactions and general fitness. Colouration can provide or deny critical information in mate choice and rival assessment, individual and species recognition, predator avoidance, prey acquisition, and …
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Sexual Signaling in Male Vervet Monkeys (Chlorocebus Pygerythrus); Influences of Hormones, Behaviour, and Parasitism on Scrotal and Penile Skin Colouration
Male secondary sexual characteristics may convey information about the signaller. The red penis and blue scrotum of male vervet monkeys make them a good species to examine variation in signal expression. We quantified colour in vervets at Lake Nabugabo, Uganda from standardized photos. We …
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Simulation and analysis of spatial audio reproduction and listening area effects
… The equivalence of human acuity to sound colouration between in situ and when using non-individualised binaural simulation was measured using colouration detection thresholds from five directions. It was shown that thresholds were equivalent within a +/-4dB equivalence boundary, supporting …
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Structurally coloured bacterial colonies
Structural colouration occurs when visible light interacts with nano-scale structures, creating vibrant colours through an interference mechanism. These non-pigmented colours are widespread in nature, and have been studied extensively in higher organisms such as plants and animals. However, …
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Age, growth, reproductive biology and diet of Spondyliosoma emarginatum (Cuvier 1830) in the West Coast National Park, South Africa
… morphometric measurements and counts, external colouration, reproductive behaviour and diet of steentjies (Spondyliosoma emarginatum) in Langebaan Lagoon were recorded between September 2004 and February 2005. Sagittal otoliths were extracted and age estimates recorded from both whole and …
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Structural colour in marine organisms: From nature to applications
Structural colouration, arising from the interaction of light with transparent materials featuring lengths comparable to visible wavelengths, is a fascinating phenomenon responsible for the appearance of many living organisms. Over the past few decades, such mechanism has been proposed to develop …
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Taphonomy of pigmentary colours in fossil insects
Extant insects are renowned for the striking colouration displayed in their cuticles. Although fossil insects are abundant and the patternings in their cuticles highly resemble those found in extant insects, these are commonly monotonal, especially in those insects preserved across deep geological …
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Developments in White Pigment Production Using Biocompatible Cellulose-Based Materials
… The primary choice for achieving white colouration in industries has traditionally been high refractive index inorganic materials, notably titanium dioxide (TiO<sub>2</sub>), which recently has raised significant concerns among consumers. Consequently, there is a growing need to explore …
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Female Ornamentation in the American Robin
… little study until recent decades. Female colouration has been considered a non-adaptive, correlated response to selection on males. However, models predict that male mate choice, female competition, and the evolution of honest signals could help explain female ornamentation, especially …
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Deposition and characterisation of nickel oxide based coatings for advanced glazing applications
… to the oxyhydroxide was detected during colouration for coatings produced using anodic electrodeposition, colloidal precipitation and r.f. sputtering (after cycling sputtered films for 1 hour in 1M KOH(aq). This information has been compared for films prepared using the different …
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Computer graphics simulation of organic and inorganic optical and morphological appearance changes.
… of the volume and skin. In order to simulate the colouration changes associated with livor mortis and mummification, a chemically-based layered skin shader that considers time and spatially varying haemoglobin, oxygen and moisture contents is proposed. The suggested approach is able to model …
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Development of a pre-selection index for cider apple (Malus x domestica Borkh.) genotypes by phenotyping a low-chill requiring red-fleshed breeding progeny
… novelty to the final product by adding red colouration and enhancing fruit quality traits associated with cider-making suitability. This innovation could lead to the creation of a unique red cider product. To achieve this, a cross was made between ‘Anna’ (a low-chill genotype) and ‘Geneva’ …
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Fitness for the Ark : are zoo bred amphibians ready to go back to the wild?
… observed changes on all the study aspects, skin colouration, body condition, vocalizations, anti-predator responses, skin associated bacteria and species recognition. The results obtained during this study show that captivity does have a significant impact on the behaviour and ecology of this …
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Intraspecific variation and ecology of a highly restricted paleoendemic (Witsenia maura) in the south-western Cape
… Sunbird. The role of the unusual black floral colouration is investigated as this colour is seldom associated with bird pollination. This plant typically exists in discreet and restricted populations in wet habitats in the South Western Cape (South Africa). The restricted nature of the plant is …
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Structural Origins and Functions of Colour Diversity in Sea Slugs: Novel Photonic Architectures, Biological Roles, and Biomimetic Applications
… inorganic nanostructures producing the photonic colouration by examining its biogenesis. Additionally, as a separate project inspired by the ability of this species to photosynthesise, I designed a novel ‘kleptoplastic’ material. I have shown that by mimicking photoprotection mechanisms utilised …
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Photonic Properties of Liquid Crystalline Hydroxypropyl Cellulose in the Solid-state
… so far, hindered by the difficulty to retain colouration in solid-state films. In this study, three methods to preserve the colour of HPC-water mesophase in the solid-state were developed, and each of these methods yielded different optical or mechanical behaviour, resulting in materials with …
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