Search results for "Skin Pigmentation"
showing 4 items of 24 documents
Diplostomum spathaceum metacercarial infection and colour change in salmonid fish
2004
Colour changes in two salmonid fish, the salmon (Salmo salar) and sea trout (S. trutta), were examined in relation to infection with the trematode Diplostomum spathaceum. This parasite had no effect on the rate of colour change in these fish, although species specific differences in colour adjustment times were observed. Increasing asymmetry in parasite numbers between the right and left eye, which could lead to the retention of vision in one eye, nevertheless tended to reduce the colour change time in salmon with moderate infection (P=0.08). This first experimental attempt to examine colour changes in fish in relation to eye fluke infections provides grounds for future investigations. The …
Melanin type and concentration determination using inverse model
2011
Abnormality of melanin production causes skin pigmentation disorders. Currently, assessment of treatment efficacy (under Physician's Global Assessment framework) only refers to visual conditions of skin surface and not the condition of the underlying skin layers and pigments. Albeit researches on models and simulations of light interaction with human skin have been reported, none has been specifically developed for pigmentation analysis of melanin types - eumelanin and pheomelanin. Therefore, our research objectives are to develop image analysis of skin pigmentation for classification and quantification of eumelanin and pheomelanin pigment types in human skin. In this research, the model is…
Dyskeratosis congenita: Report of a case with literature review
2007
Leukoplakic lesion is not uncommon in clinical practice but its occurrence as a component of a syndrome is rare. Dyskeratosis congenita is a rare genodermatosis, which is characterized by triad of skin pigmentation, nail dystrophy and leukoplakic lesion in the oral cavity. It is important for dentists to now about Dyskeratosis Congenita because these leukoplakic lesions can spontaneously undergo malignant transformation. Majority of cases have been reported in dermatology or pediatrics literature whereas only few reports have appeared in dental literature. The purpose of reporting this case with review of recent literature is to create better awareness among dentists about the multisystem m…
Sole coloration as an unusual aposematic signal in a Neotropical toad
2019
Many animals have evolved remarkable strategies to avoid predation. In diurnal, toxic harlequin toads (Atelopus) from the Amazon basin, we find a unique colour signal. Some Atelopus populations have striking red soles of the hands and feet, visible only when walking. When stationary, the toads are hard to detect despite their yellow-black dorsal coloration. Consequently, they switch between high and low conspicuousness. Interestingly, some populations lack the extra colour display of the soles. We found comprehensive support that the red coloration can act as an aposematic signal directed towards potential predators: red soles are significantly more conspicuous than soles lacking red colora…