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Genetic approaches to the analysis of body colouration in Nile tilapia (Oreochromis niloticus)Rajaee, Amy H. January 2011 (has links)
Body colouration in tilapia is an important trait affecting consumer preference. In the Nile tilapia (Oreochromis niloticus), there are three colour variants which are normal (wild type), red and blond. In some countries, the red variant is important and reaches higher prices in the market. However, one major problem regarding red tilapia culture is their body colouration which is often associated with blotching (mainly black but also red) which is undesirable for the consumer. The overall aim of this work was to expand knowledge on various aspects of body colouration in Nile tilapia using genetic approaches. The results of this research are presented as four different manuscripts. The manuscripts (here referred as Papers) have either been published (Paper IV) or are to be submitted (Paper I, II and III) in relevant peer reviewed journals. Paper I and II investigated the inheritance of black blotching and other body colour components of the red body colour. Specifically, Paper I consisted of two preliminary trials (Trial 1 and 2), to look at the ontogeny of black blotching and body colour components over a period of six months. Trial 1 investigated the effect of tank background colour (light vs dark) on black blotching and other body colour components and was carried out using a fully inbred (all female) clonal red line. Trial 2 was carried out using mixed sex fish and was aimed to investigate the association of black blotching with the sex of the fish. The results from this study were used to guide the experiment described in Paper II. Sixteen red sires with various levels of black and red blotching were crossed to clonal females and the inheritance of blotching and other body colour components were investigated using parent-offspring regressions. The results showed no significant heritability for black blotching and body redness, but a significant correlation for body redness and black blotching was found in female offspring at one sampling point suggesting that attempts to increase body redness may increase black blotching, as had been hypothesized. Paper III was divided into two parts. The first objective was to map the blond locus onto the tilapia linkage map and the second was to investigate the interaction of the blond and red genes on black blotching using the blond-linked markers to distinguish different blond genotypes in heterozygous red fish (i.e. RrBlbl or Rrblbl). In the blond fish, the formation of melanin is almost blocked via much reduced melanophores and this feature may be able to help reducing the black blotching in red tilapia. Two intraspecific families (O. niloticus) and one interspecific family (O. aureus and O. niloticus) were used as mapping families and the blond locus was located in LG5. Four out of eight markers were successfully used to assess the interaction of blond on red blotched fish. The blond gene did not significantly reduce the area of blotching but did reduce the saturation (paler blotching) and enhanced the redness of body colour in the Rrblbl fish compared to the RrBlbl group. Finally, Paper IV aimed to find out the effect of male colouration on reproductive success in Nile tilapia. A choice of one wild type male and one red male was presented to red or wild type females and these fish were allowed to spawn under semi-natural spawning conditions. Eggs were collected from the female’s mouth after spawning and paternity was assessed using microsatellite genotyping and phenotype scoring. No significant departures from equal mating success were observed between the red and wild type males, however there was a significant difference between the red and wild type females in the frequency of secondary paternal contribution to egg batches. The results suggest that mating success of wild type and red tilapia is approximately equal. The results from this research help to broaden our knowledge and understanding on the aspects of body colouration in Nile tilapia and provide fundamental information for further research.
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Aposematism, Crypsis and Population Differentiation in the Strawberry Poison FrogRudh, Andreas January 2012 (has links)
Evolutionary transitions between the two major predator avoidance strategies aposematism and crypsis are expected to be associated with changes in many important traits of animals. However, empirical studies on populations experiencing ongoing or recent transitions between these strategies are rare. This thesis investigates the co-evolution of traits among populations of the Strawberry poison frog D.pumilio in Bocas del Toro, Panama. I found that all investigated populations were genetically distinct but that colour and pattern did not correlate with genetic or geographic distance, which suggests that selection needs to be invoked to explain the observed variation. Based on the chromatic contrast between frog dorsal colour and the natural habitat substrates used by the frogs, the populations were defined as bright or dull coloured. I found that frogs from bright coloured populations were larger. This is expected if aposematism is enhanced by large signals while crypsis is enhanced by small size. Further, individuals from bright coloured populations had a coarser black dorsal pattern, which is expected if crypsis is impaired by a bold pattern. The importance of pattern coarseness was confirmed by an avian detection experiment showing that coarse patterned dark green prey were more easily detected than dark green prey without pattern or with fine pattern. I put forward the hypothesis that enhanced protection, gained by aposematism, may affect behaviours that influence dispersal and pairing patterns. Indeed, males from bright coloured populations displayed at more exposed sites and showed a tendency to be more explorative and aggressive. In summary, my results show that the bright and dull coloured populations most likely represent an aposematic and a cryptic strategy, respectively. Furthermore, I show that evolutionary changes between aposematism and crypsis can be associated with coevolution of both morphology and behaviour. I argue that this coevolution may increase the likelihood of both pre- and post-zygotic reproductive isolation. This is because greater phenotypic differences between populations increase the likelihood of selection against badly adapted migrants and hybrids with intermediate traits.
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Speciation genomics : A perspective from vertebrate systemsVijay, Nagarjun January 2016 (has links)
Species are vital entities in biology. Species are generally considered to be discrete entities, consisting of a group of (usually interbreeding) individuals that are similar in phenotype and genetic composition, yet differ in significant ways from other species. The study of speciation has focussed on understanding general evolutionary mechanisms involved in the accumulation of differences both at the genetic and phenotypic level. In this thesis, I investigate incipient speciation, an early stage of divergence towards evolutionary independence in closely related natural populations. I make ample use of recent advances in sequencing technology that allow 1) characterizing phenotypic divergence at the level of the transcriptome and 2) delineate patterns of genetic variation at genome-scale from which processes are inferred by using principles of population genetic theory. In the first paper, we assembled a draft genome of the hooded crow and investigated population differentiation across a famous European hybrid zone. Comparing sequence differentiation peaks between and within the colour morphs, we could identify regions of the genome that show differentiation only between colour morphs and that could be related to gene expression profiles of the melanogenesis pathway coding for colour differences. The second paper expands on the first paper in that it includes crow population samples from across the entire Palaearctic distribution spanning two additional zones of contact between colour morphs. The results suggest that regions associated with selection against gene flow between colour morphs were largely idiosyncratic to each contact zone and emerged against a background of conserved 'islands of differentiation' due to shared linked selection. The third paper focusses on five killer whale ecotypes with distinct feeding and habitat specific adaptations. Differing levels of sequence differentiation between these ecotypes places them along a speciation continuum and provides a unique temporal cross-section of the speciation process. Using genome scans we identified regions of the genome that show ecotype specific differentiation patterns which might contain candidate genes involved in adaptation. In the fourth and final paper, I assumed a comparative genomic perspective to the problem of heterogeneous genomic differentiation during population divergence. The relatively high correlations in the diversity landscapes as well as differentiation patterns between crow, flycatcher and Darwin's Finch populations is best explained by conservation in broad-scale recombination rate and/or association with telomeres and centromeres conducive to shared, linked selection.
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Caracterização e ocorrência de carne pálida em frangos de corte e seu efeito na elaboração de produtos industrializados /Komiyama, Claudia Marie, 1978- January 2006 (has links)
Orientador: Ariel Antonio Mendes / Banca: Roberto de Oliveira Roça / Banca: Edson Gonçalves de Oliveira / Abstract: It was undertaken two assays aiming to evaluate quality characteristics of broiler pale-colour meat and compare to normal-colour meat (assay 1), and evaluate sensorial differences between these meat types (assay 2). For assay 1, it was collected 52 pale and normal fillets from a slaughtering line, based on fillet colouration. It was measured pH, temperature, colour and R value on different times post mortem (0, four, 24 hours). Samples were send to the laboratory of FMVZ/UNESP, Botucatu campus, and after 24 hours post mortem it was evaluated the remaining meat quality parameters (drip loss, retention and absorption water capacity, denaturation protein, cocking loss and texture. For assay 2, it was collected 40 each pale and normal fillets from a commercial slaughtering and after 24 hours post mortem it was realized the evaluation of sensorial characteristics. For breast fillets of broilers with pale colouration, glycolysis had started with 6,86 pH value and reached to final pH of 5,73 at 24 hours post mortem while normal colouration ones presented initial pH of 6,80 and final pH, after 24 hours post mortem of 5,85. It was observed difference (p 0,05) between pale and normal fillets for pH, L * value, redness, CRA, PPC and protein denaturation. / Resumo: Foram realizados dois ensaios, sendo que o Ensaio 1 teve por objetivo avaliar as características de qualidade da carne de frangos de corte de coloração pálida e comparar com a de coloração normal e, o Ensaio 2, avaliar as diferenças sensoriais destes tipos de carnes. Para o Ensaio 1, foram coletados 52 filés pálidos e normais selecionados na linha de abate baseado pela sua coloração. Foi realizada a mensuração do pH, temperatura, cor e valor R nos tempos de zero, 4 e 24 horas post-mortem. As amostras foram encaminhadas ao laboratório da FMVZ/UNESP, campus de Botucatu e após 24 horas post-mortem procedeu-se as demais análises de qualidade de carne em que foram avaliadas as características de perda por exsudação, capacidade de retenção (CRA) e absorção de água, perdas de peso por cozimento (PPC) e força de cisalhamento. Para o Ensaio 2, foram coletados 40 filés pálidos e normais de abatedouro comercial, e após 24 horas post-mortem procedeu-se a avaliação das características sensoriais. Para os filés de peitos de frangos de coloração pálida, a glicólise teve inicio com o valor de pH 6,86 e atingiu pH final 5,73 às 24 horas post-mortem enquanto que os filés de peitos de coloração normal apresentaram pH inicial de 6,80 e pH 24 horas post-mortem de 5,85. Houve diferença significativa (p 0,05) entre os filés pálidos e normal para os parâmetros de pH, valor L*, teor de vermelho, CRA, PPC e desnaturação protéica. / Mestre
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Vztah hierarchického postavení ve skupině s personalitními charakteristikami a melaninovým zbarvením u holuba domácího (Columba livia f. domestica) / Interaction between hierarchy, personality traits and melanin-based colouration in pigeons (Columba livia domestica)Vohralíková Houšková, Markéta January 2020 (has links)
An individual position in social hierarchy is the key mechanism, how an individual could gain a priority access to more quality food resources, find an attractive sexual partner to reproduce and find territory with low predation risk and maintain its fitness in total. Personality is supposed to be an important factor how an individuals keep their positions in social groups. The consistent individual variability in aggressive behaviour is closely related to the expression of melanin-based colouration and testosterone levels in blood. More explorative, aggressive, bolder and darker-coloured individuals are supposed to achieve higher dominance rank in social structures. But this prediction was barely tested. The main aims of this diploma thesis were: to find consistent individual variability in social and non-social context to confirm personality traits and to define connection between an individual variability in agonistic and explorative behaviour and melanin-based colouration in relation to social rank in experimental group of domestic pigeons (Columba liva f. domestica) under human care. Unfortunately, personality could not be defined and even more, there was no significant correlation between dominant position in social hierarchy and individual behavioural variability in social and non-social...
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Genus, estetik & gränssnitt : En empirisk studie om hur användarupplevelse påverkas genom genuskodning av gränssnitt. / Gender, aesthetics & interfaces : An empirical study of how user experience is affected by gendered interfaces.Connysson, Ellen, Jarlevid, Marcus January 2020 (has links)
HCI och interaktionsdesign är starkt kopplade till användarupplevelse (UX), som innebär att fokusera på användarupplevelse och att prioritera mänskliga värderingar, samt etiska och politiska ideal som ofta är närvarande inom HCI. Studiens syfte har varit att undersöka om genusstereotypisk design samspelar med hur människor av genuset man eller kvinna upplever den, samt att undersöka normativa genusstereotyper som påverkar hur gränssnitt designas beroende på om dess målgrupp är män eller kvinnor. Detta eftersom genus är en social konstruktion som skapas av saker och ting i samhället, vilket formar en bild av hur män och kvinnor ”ska” vara. Design är en del av denna genuskonstruktion, eftersom det bidrar till stereotyper över vad som är ’manligt’ och ’kvinnligt’, genom till exempel normativa färgval. Könskodad design är därför en bidragande faktor till att normer och stereotyper för genus upprätthålls i samhället. Studien har gjorts med en inledande litteraturstudie utifrån begreppen användarupplevelse, estetik, genuskodning inom human computer interaction, genus och genus som en social konstruktion. Därefter har en enkät nyttjats för en deskriptiv kvantitativ datainsamling med metoderna Structured Word Choice och en numerisk rankning, där upplevelsen av ett kalendergränssnitt testats, med en maskulin och en feminin färgsättning som valts utifrån befintlig litteratur om genustypiska färger. Därtill avslutandes datainsamlingen med intervjuer. Resultatet visat vissa tendenser som tyder på färgsättningen av ett gränssnitt upplevs viktigare av kvinnor och att både manliga och kvinnliga informanter till en viss del föredrar det gränssnitt som var färgsatt för dem, men endast marginellt. De flesta hade en neutral upplevelse av både den maskulina och feminina färgsättningen av gränssnittet. Slutsatsen som dragits baserat på nämnda metoder är att genustypisk färgsättning till största del inte påverkar användares upplevelse av ett gränssnitt. Båda genusen anser att funktion är viktigare än form, vilket är vad som bör vara i fokus när en god användarupplevelse av ett gränssnitt ska skapas. / HCI and interaction design are strongly linked to user experience (UX), which contains a built-in focus on user experiences and an emphasis on human values, which indicates that these values as well as ethical and political ideals are often present in HCI. The purpose of this study was to investigate if gender stereotypical design affects how people of the male or female gender experience it, and to investigate normative gender stereotypes that affect how interfaces are designed depending on if the target group are men or women. Gender is a social construct created by things in society, which forms a picture of how men and women "should" be. Design is part of this gender construction, because it contributes to the stereotypes of what is "male" and "female", for example through normative colour choices. Gender-coded design is a contributing factor in standardizing and maintaining stereotypes of gender in society. The study has been done with an introductory literature study based on the concepts user experience, aesthetics, gender coding in human computer interaction, gender, and gender as a social construct. A survey was used for descriptive quantitative data collection with the methods Structured Word Choice and numerical ranking, where the experience of a calendar interface has been tested, with a masculine and a feminine colour scheme based on existing literature on genus-typical colours. Complimentary data was collected using interviews. Certain trends emerged that indicate the coloration of an interface to be more important to women and that both male and female informants to some extent prefer the interface that was coloured according to their gender, but only marginally. Most had a neutral experience of both the masculine and feminine coloration of the interface. The conclusion drawn based on the methods above is that gender-typical colouration does not affect the users experience in any major ways. Both genders believe that function is more important than form, which is what should be the focused on when creating a good user experience in a product.
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Jsou velikost těla a druhově specifické zbarvení důležitými znaky pro rozpoznávání predátorů potenciální kořistí? / Are body size and specific species colouration important cues for predator recognition by their potencial prey? Diplomová práceAntonová, Kateřina January 2018 (has links)
I tested influence of a body size and overal colouration in feeders experiments on recognition of sparrowhawk (Accipiter nisus) by chosen species of passerine. Experiments were conducted in years 2015 ̶ 2018. I used a plush dummies which carried a specific featuress of raptor (hooked beak, claws) and specific features of genus Accipiter (yellow eyes, respectively yellow eyes and overal colouration). As a control, dummy of harmless pigeon was used. Smaller dummies (size of a great tit) were not recognized as a raptor regardless of colouration. Large dummies with colouration of great tit and pigeon were not recognized as a raptor as well. On a contrary, large dummy with colouration of robin was recognized as a raptor, respectively sparrowhawk. Most birds who were flying to the feeders, at first payed attention to global features (size, overal colouration). If these features belong to well-known harmless bird, then local features (particular) which characterize raptor or sparrowhawk had no effect. Birds did not pay attention to them. Therefore it depends on a context, in which potential local key features occure.
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Laser textile design : the development of laser dyeing and laser moulding processes to support sustainable design and manufactureMorgan, Laura January 2016 (has links)
This research developed new creative opportunities for textile design by investigating CO2 laser processing technology to achieve surface design and three-dimensional effects. A practice based and interdisciplinary textile design methodology was employed, integrating scientific and technical approaches with a reflective craft practice. It was found that the synthesis of design and science was imperative to achieving the research goal of evolving techniques that have opened new design opportunities for textile design whilst being viable and communicable for industrial and commercial application. Four distinct Laser Textile Design techniques were developed in this research including: a laser enhanced dyeing technique for wool and wool blends; Peri-Dyeing, a laser dye fixation technique; a laser moulding technique; and a laser fading linen technique.
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The Mapping of Quantitative Trait Loci Associated with Morphometrics and Parr Marks in an F2 cross of European and North American Strains of Cultured Atlantic SalmonPedersen, Stephanie 01 May 2013 (has links)
Mapping quantitative trait loci (QTL) for traits under consideration for genetic improvement is becoming more common for many aquatic species, including Atlantic salmon. The objective of the study was to map QTL associated with length, weight, shape, parr mark number and contrast in three F2 hybrid families of European and North American strains of Atlantic salmon using single nucleotide polymorphisms. GridQTL software was used to perform separate analyses for male and female linkage maps. Numerous highly significant QTL were detected for every trait. Locations of QTL differed based on age and map used. Some QTL locations for the analyzed traits were similar to those of other studies on purebred and backcross Atlantic salmon populations; however, many more QTL were detected in the hybrid F2’s. The amount of genetic variation in skin colour and pattern displayed within the transAtlantic F2 families greatly exceeded the ranges seen in nature. / NSERC Strategic Grant
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Behavioural differences between species and populations in the killifish genus Nothobranchius / Cognitive and aggressive behaviours in the annual killifish, Nothobranchius orthonotusKubická, Lucie January 2016 (has links)
I used annual killifish Nothobranchius orthonotus to investigate two separate questions related to behavioural aspects of their life history. The first study focused on spatial cognitive ability of two N. orthonotus populations that originated from temporary pools that varied in their expected duration due to differences in annual precipitation patterns (dry and humid region). Test of cognition was based on the ability to learn to find food in a dichotomous test. It was assumed that learning ability differs between populations when tested in young and old age along with their difference in captive lifespan. Additionally, association between cognitive ability and other life history traits was tested. It was found that: (1) there was no difference in the ability to learn spatial task between populations; (2) both populations had similar lifespan with no cognitive decay in older age, and older fish from dry region population had committed even less errors in the learning task than they did as young fish; (3) fish were able to effectively learn the task but (4) solitary fish had lower learning ability than group-reared fish; (5) longer- living fish were quicker learners; (6) high resting metabolic rate was associated with more effective learning; (7) hesitant fish found the food reward in learning task...
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