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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Perspectivas sobre o reconhecimento de padrões de modularidade e suas implicações para a evolução de morfologias complexas / On the recognition of modularity patterns and its implications for the evolution of morphological systems

Guilherme Garcia 07 April 2016 (has links)
A modularidade é uma propriedade característica que sistemas biológicos exibem em relação à distribuição de interações entre seus elementos constituintes; neste contexto, um módulo é um subconjunto de elementos que interagem entre si mais do que com outros subconjuntos. Em relação aos sistemas morfológicos, tais propriedades referem-se geralmente à estrutura do componente linear do mapa genótipo/fenótipo; no entanto, as interações genéticas, ontogenéticas e funcionais que produzem fenótipos são descritas de forma adequada através de dinâmicas não-lineares, e uma apreciação completa da complexidade destas interações é necessária para a compreensão das propriedades variacionais do fenótipo. Ademais, dados avanços metodológicos na área da morfometria, é possível escolher diferentes maneiras de representar a variação morfológica, e as diferenças entre as representações podem impactar inferências feitas sobre estas propriedades variacionais. A presente tese tem como objetivo explorar a relação entre representações morfométricas e a caracterização das propriedades variacionais, focada na análise comparativa de tais propriedades em uma escala macroevolutiva; Primatas Antropóides são utilizados como modelo, dada a disponibilidade de uma grande base de dados de mensurações cranianas destes organismo. Esta relação foi avaliada sob três perspectivas diferentes. Em primeiro lugar, estima-se taxas de erro associadas aos testes de hipótese que descrevem padrões de modularidade, relacionadas com três representações morfométricas distintas; tal avaliação é também associada à exploração de um subconjunto da base de dados utilizada aqui, levando-se em consideração a dinâmica de interações ontogenéticas que produzem o crânio dos Antropóides. Os resultados deste capítulo implicam que uma dessas representações, resíduos de Procrustes, não são capazes de detectar padrões de modularidade neste contexto, considerando suas propriedades matemáticas específicas. Outras duas representações, distâncias entre marcos anatômicos e variáveis locais de forma, produzem resultados semelhantes, que estão diretamente associados à dinâmica de desenvolvimento, e as diferenças que elas apresentam são consistentes com suas diferenças principais; taxas de erro para os testes sobre as duas representações também são aceitáveis. O próximo capítulo trata da comparação entre estas duas representações no que diz respeito a estas diferentes propriedades, focado em estimar relações alométricas associadas às variáveis locais de forma e a relação entre estas estimativas e os padrões de modularidade estimados para distâncias entre marcos anatômicos. Os resultados encontrados enfatizam que os padrões de modularidade observados em distâncias entre marcos são consequência da alometria; linhagens como Homo e Gorilla, que apresentam padrões distintos de modularidade para as distâncias entre marcos estão associados a mudanças substanciais nas relações alométricas dos caracteres cranianos. O último capítulo explora a estrutura filogenética de mudanças nas propriedades variacionais fenotípicas na diversificação de Anthropoidea, considerando apenas variáveis de forma locais, uma vez que este capítulo também visa reforçar os resultados anteriores obtidos a partir de distâncias entre marcos, considerando-se um tipo diferente de representação morfométrica. Este capítulo muda o foco de testes a respeito de padrões de modularidade definidos a priori em direção a estimar a incerteza relacionada à estrutura de matrizes de covariância, decomposta sobre a filogenia de Anthropoidea. Os resultados obtidos demonstram que as mudanças na estrutura de covariância nesta linhagem são localizadas nas mesmas regiões do crânio ao longo de toda a história evolutiva do grupo, enquanto outras regiões mantêm associações estáveis. Assim, quando se considera as diferentes propriedades de representações morfométricas cuidadosamente, inferências feitas a partir de tais representações sobre propriedades variacionais são de fato compatíveis / Modularity is a characteristic property biological systems exhibit regarding the distribution of interactions between their composing elements; in this context, a module is a subset of elements which interact more among themselves than with other subsets. Regarding morphological systems, such property usually refers to the structure of the linear component of the genotype/phenotype map; however, the genetic, developmental, and functional interactions that produce phenotypes are often best described by non-linear dynamics, and a full appreciation of the complexity of such interactions is necessary for understanding phenotypic variational properties. Furthermore, given methodological advances in the field of morphometrics, one may choose different ways to represent morphological variation, and differences between representations may impact inferences made regarding variational properties. The present dissertation aims at exploring the relationship between morphometric representations and the characterization of variational properties, focusing on the comparative analysis of such properties on a macroevolutionary timeframe; Anthropoid Primates are used as a model lineage, given the availability of a large database of skull measurements. This relationship was evaluated under three different perspectives. First, an estimation of the error rates associated with tests for hypothesis that describe modularity patterns related to three different morphometric representations; such evaluation is also associated with an exploration of a subset of the database used here, considering the dynamical properties of developmental interactions that produce the Anthropoid skull. The results of this chapter imply that one of such representations, Procrustes residuals, fails to capture modularity patterns in this setting, considering its particular mathematical underpinnings. Other two representations, interlandmark distances and local shape variables, produce similar results which are directly associated with developmental dynamics, and the differences they exhibit are consistent with their different properties; error rates for tests over both representations are also acceptable. The next chapter deals with comparing these two representations with respect to these different properties, focusing on estimating allometric relationships over local shape variables and the relationship between such estimates and modularity patterns estimated for interlandmark distances. The results found stress out that modularity patterns observed in interlandmark distances are a consequence of allometry; lineages such as Homo and Gorilla, which exhibit distinct modularity patterns in interlandmark distances are associated with substantial changes in allometric relationships for skull traits. The last chapter explores the phylogenetic structure of changes in phenotypic variational properties across Anthropoid diversification, considering local shape variables alone, since this chapter also aims at reinforcing previous results obtained from interlandmark distances, considering a different type of morphometric representation. This chapter shifts the focus from testing a priori-defined modularity patterns to estimating the uncertainty related to covariance matrix structure decomposed over the Anthropoid phylogeny. The results obtained demonstrate that changes in covariance structure on this lineage are localized in the same skull regions across the entire evolutionary history of Anthropoidea, while other regions maintain stable associations. Thus, when one considers the different properties of morphometric representations carefully, inferences made from such representations regarding variational properties are in fact compatible
172

Estudo genético e morfológico de populações de Aedes aegypti (Culicidae) na área metropolitana de São Paulo - SP. / Genetic and morphological study of Aedes aegypti (culicidae) population in São Paulo (SP) metropolitan area.

Paloma Oliveira Vidal 15 December 2010 (has links)
Estudos populacionais de Aedes aegypti são de grande importância para o desenvolvimento de estratégias de controle, mas infelizmente o Estado de São Paulo carece desse tipo de estudo. Devido a esse contexto, o objetivo do trabalho foi avaliar a variabilidade genética e fenotípica de 4 populações de Ae. aegypti na área metropolitana de São Paulo. As análises interpopulacionais de forma em ambos os sexos mostraram variabilidade morfológica alar que, no entanto não indica estruturação populacional. Não foi observada correlação entre valores de distância fenética alar e distância geográfica para machos (r =-0,03) e fêmeas (r=0,34). Estruturação populacional foi detectada (Fst global=0,062) e baixo fluxo gênico (Nm=0,47) foi presumido nas quatro localidades. Foi observada correlação entre as distâncias genética e geográfica (r=0,76). Os dois marcadores populacionais aqui empregados aparentemente têm graus de resolução distintos para eventos microevolutivos, tendo sido DNA microssatélite ligeiramente mais sensível para acusar estruturação populacional. / Populational studies of Ae. aegypti are important to develop control strategies, but unfortunately the State of São Paulo lacks such studies. Despite this context, the objective of this work was to evaluate genetic and phenotypic variability of population samples of Ae. aegypti from four collecting sites in the metropolitan area of São Paulo city. The interpopulational analysis of shape for females and males showed morphological variability in wings, but did not indicate population structure. Pairwise fenetic distances among populations were not correlated to the geographic distances for males (r=-0.03) and females (r =0.34). Populational structure was detected (global Fst= 0.062) and low gene flow (Nm= 0.41) was presumed among four locations. Pairwise genetic distances among populations were correlated to the geographic distances (r = 0.76). The two populational markers used here apparently have different degrees of resolution for microevolutionary events, being that microsatellite DNA were slightly more sensitive in revealing populational structure.
173

Diversification des orchidées méditerranéennes : niches de pollinisation, évolution des traits floraux et taxonomie intégrative / Diversification of Mediterranean orchids : pollination niches, floral trait evolution and integrative taxonomy

Joffard, Nina 18 December 2017 (has links)
Les interactions avec les pollinisateurs font partie de la niche écologique des orchidées et ont joué un rôle dans leur diversification taxonomique et florale. Au cours de cette thèse, j’ai d’abord analysé l’architecture du réseau orchidées-pollinisateurs en région Euro-Méditerranéenne et montré que la similarité de niches de pollinisation entre orchidées était fonction de leur distribution spatio-temporelle, suggérant un certain opportunisme dans les interactions orchidées-pollinisateurs. Je me suis ensuite intéressée au rôle des pollinisateurs dans l'évolution des traits floraux dans deux groupes d’orchidées. J’ai d’abord montré une différentiation dans les traits floraux des trois taxa du groupe Anacamptis coriophora, probablement causée et maintenue par un processus de sélection divergente. En cartographiant les interactions avec les pollinisateurs et les odeurs florales sur la phylogénie de la section Pseudophrys, j’ai ensuite montré que l'évolution de l'odeur florale était conditionnée par une sélection exercée par les pollinisateurs et par des contraintes phylogénétiques. Enfin, j’ai mis au point une démarche de taxonomie intégrative basée sur des données moléculaires, morphométriques et chimiques dans le genre Ophrys. Avec cette démarche, j’ai confirmé le rang taxonomique des trois espèces du groupe O. insectifera et proposé de fusionner deux paires d’espèces parmi les Pseudophrys. Une meilleure compréhension des facteurs qui façonnent la niche de pollinisation et du rôle des pollinisateurs dans l'évolution des traits floraux et la spéciation chez les orchidées Euro-Méditerranéennes devrait nous permettre d’améliorer la conservation de ces espèces emblématiques. / Interactions with pollinators are part of orchids’ ecological niches and have played a role in their taxonomic and floral diversification. During this thesis, I have analysed the architecture of the orchid-pollinator network in the Euro-Mediterranean region and shown that similarity in pollination niches between orchids primarily depends on their spatio-temporal distribution, suggesting that orchid-pollinator interactions are more opportunistic than previously thought. Then, I have been interested in the role of pollinators in floral trait evolution in two orchid groups. I have shown a differentiation in floral traits of the three taxa of the Anacamptis coriophora group, probably caused and maintained by a process of divergent selection. Then, by mapping interactions with pollinators and floral odours on the phylogeny of the section Pseudophrys, I have shown that floral odour evolution is conditioned by pollinator-mediated selection and by phylogenetic constraints. Finally, I have developed an integrative taxonomic approach based on molecular, morphometric and chemical data in the genus Ophrys. With this approach, I have confirmed the taxonomic rank of the three species of the O. insectifera group and proposed to merge two species pairs among Pseudophrys. A better understanding of the factors that have shaped pollination niches and of the role of pollinators in floral trait evolution and speciation in Euro-Mediterranean orchids should allow us to improve the conservation of these emblematic species.
174

Quantitative Morphological Classification of Planetary Craterforms Using Multivariate Methods of Outline-Based Shape Analysis

Slezak, Thomas Joseph 01 December 2017 (has links)
Craters formed by impact and volcanic processes are among the most fundamental planetary landforms. This study examines the morphology of diverse craterforms on Io, the Moon, Mars, and Earth using quantitative, outline-based shape analysis and multivariate statistical methods to evaluate the differences between different types of. Ultimately, this should help establish relationships between the form and origin of craterforms. Developed in the field of geometric morphometrics by paleontological and biological sciences communities, these methods were used for the analysis of the shapes of crater outlines. The shapes of terrestrial ash-flow calderas, terrestrial basaltic shield calderas, martian calderas, Ionian paterae, and lunar impact craters were quantified and compared. Specifically, we used circularity, ellipticity, elliptic Fourier analysis (EFA), Zahn and Roskies (Z-R) shape function, and diameter. Quantitative shape descriptors obtained from EFA yield coefficients from decomposition of the Fourier series that separates the vertical and horizontal components among the outline points for each shape. The shape descriptors extracted from Z-R analysis represent the angular deviation of the shapes from a circle. These quantities were subjected to multivariate statistical analysis including principal component analysis (PCA) and discriminant analysis, to examine maximum differences between each a priori established group. Univariate analyses of morphological quantities including diameter, circularity, and ellipticity, as well as multivariate analyses of elliptic Fourier coefficients and Z-R shape function angular quantities show that ash-flow calderas and paterae on Io, as well as basaltic shield calderas and martian calderas, are most similar in shape. Other classes of craters are also shown to be statistically distinct from one another. Multivariate statistical models provide successful classification of different types of craters. Three classification models were built with overall successful classification rates ranging from 90% to 75%, each conveying different shape information. The EFA model including coefficients from the 2nd to 10th harmonic was the most successful supervised model with the highest overall classification rate and most successful predictive group membership assignments for the population of examined craterforms. Multivariate statistical methods and classification models can be effective tools for analyzing landforms on planetary surfaces and geologic morphology. With larger data sets used to enhance supervision of the model, more successful classification by the supervised model could likely reveal clues to the formation and variables involved in the genesis of landforms.
175

A morphological and biometric study of the facial characteristics of two South African childhood populations at different age levels

Briers, N. January 2015 (has links)
Positive identification can be problematic if fingerprinting, DNA, dental history, etc. are no longer available. This may be possible through techniques such as facial approximation, but any form of craniofacial identification requires intimate knowledge of human craniofacial anatomy. Where children are involved, craniofacial changes due to facial growth further complicate matters and require knowledge of tissue thickness and variation in facial shapes. These have hardly been studied in children of African descent. The aims of this study were to provide data on tissue thickness and craniofacial proportions of South African Black and Coloured children and to document the lateral profile shape changes between the ages of 6 and 13 years. Tissue thickness was measured using cephalograms of South African children (n = 388). After digitizing the images, tissue thickness measurements were taken at 11 mid-facial landmarks from each image using the iTEM measuring program. Craniofacial proportions were assessed through assessing standardized anterior and lateral facial photographs of 1749 children. Measurements of facial features were taken using iTEM, from which 28 standard facial indices were calculated. For both tissue thickness and craniofacial indices comparisons between groups per age, sex and ancestry were statistically analyzed. In addition, geometric morphometrics were used to describe lateral facial shape changes and differences age, sex and ancestry (n = 800). The results showed that tissue thickness differences at lower face landmarks are more pronounced in age groups per ancestry as opposed to differences per age and sex. Facial profile per facial shape, class and ancestry showed differences at all landmarks. Craniofacial indices indicated that Coloured children have wider heads, foreheads and faces compared to Black children. The height of the nose and lower lip is longer in Coloured children compared to Black children. In Coloured children, mandibular height and lower face height is shorter in relation to total face height. Males have wider heads, foreheads, mandibles and faces compared to females. The degree of prognathism is dictated by ancestry and to a lesser extent by age and sex as findings showed that maxillary prognathism was more prominent in Black children, while mandibular prognathism were more pronounced in male children. South Africans have a relative concave lateral facial profile due to the maxilla and mandible being more prognathic than in North American children. Differences in lateral face shape between children of various ages, sexes and ancestral groups were visualized through the relative displacement of landmarks related to the forehead and lower face. The resultant differences in lateral facial profile can assist in more accurate estimation of age and ancestry of unknown children. This research created reference datasets for tissue thickness and craniofacial indices of South African children of Black and Coloured ancestry per age and sex that will be useful in the diagnosis of facial dysmorphology and for facial reconstruction / approximation of juvenile remains. It also shed more light on facial growth patterns in the various groups. / Thesis (PhD)--University of Pretoria, 2015. / tm2015 / Anatomy / PhD / Unrestricted
176

Původ a biologická afinita údajné gravettienské mandibuly Předmostí 30 ze sbírek Moravského zemského muzea. / Origin and Biological Affinity of the Alleged Gravettian Mandible Předmostí 30.

Drahošová, Michala January 2015 (has links)
Dissertation solves the problem of the origin of the mandible from collection of Moravian Museum in Brno. Publications of authors working in the location Předmostí u Přerova since the year 1884 have been used to achieve this goal. Simultaneously records in the incremental books of MZM in Brno have been researched, unfortunately without success. Therefore research of the biological affinity of the mandible P30 with others gravettiens discovery has been accepted as well as variability of recent humans. For study we used methods of geometric morphometrics, which allows us better clarify shape discrepancies in comparison with standard analytic methods. Comparison of shape variability of the mandible we used 91 cranial CT exposures of the recent Czech population. We placed 42 landmarks to segmented 3D models of the mandible and we made a PCA analysis. To extend the argument for justifiability to incorporate studied sample among discoveries from Předmostí u Přerova we created file of linear proportions of the tooth crown based on available publications and our own measuring. Morphological study, shape analysis of the mandible and dimension of the teeth leads us to results that the mandible P30 in our study can really belong to the Gravettien Age. Key words: Mandible, Molars, Předmostí u Přerova,...
177

Variabilita křídelní žilnatiny vážek (Insecta: Odonata) - geometricko-morfometrická studie / Variation in dragonfly wing venation with application of geometric morphometrics (Insecta: Odonata)

Přibylová, Petra January 2015 (has links)
The pattern of wing venation in dragonflies (Odonata) bears a set of characters commonly used in systematics. The aim of this thesis is to identify the wing venation variability of dragonflies by various methods of geometric morphometric. The wing venation variability was examined on the level of suborder, family, species and also in respect to dimorphism through the principal component analysis (PCA), redundancy analysis (RDA) and centroid size. Data set consisting of images of 46 dragonfly species, belonging to 43 genera and 24 families was obtained from institutional entomological collections. The research carried out that Zygoptera have a large variety of wing contours. The wing venation variability of Epiprocta is shown primarily in the costa and node area. Between sexes there is no noticeable difference in shape or structure of the wing. The ratio between wing length and width and the pterostigma shape is dependent on dragonfly body size. Key words: Odonatoptera, Odonata, Epiprocta, Zygoptera, wing venation, variability, geometric morphometrics
178

Postnatální ontogeneze lebky želvy nádherné (Trachemys scripta) / Postnatal Ontogenesis of the Skull of the Pond Slider Turtle (Trachemys scripta)

Čtrnáctová, Lenka January 2018 (has links)
This thesis focuses on the descriptive analysis of skull morphology of the pond slider turtle (Trachemys scripta elegans). The general approach was an osteological preparation of the skulls and photographic documentation (following standardised procedures) of a larger sample of specimens. The collected data was used as a background for subsequent GMM analyses. Main hypotheses of this project were: 1) the skull of T. s. elegans is sexually dimorphic; 2) the skull of T. s. elegans constitutes of several independent modules. The objective of this thesis was therefore to describe the postnatal ontogenesis of the model taxon and to determine the developmental trends of its cranial structures. It was shown that the skull of T. s. elegans is sexually dimorphic in shape mainly due to differences in allometric growth. These differences probably reflect different nutritional requirements. The skull of T. s. elegans is formed out of four modules. These are: facial, central, basicranial, and possibly also zygomatic-pterygoideal modules.
179

Sociální interakce a morfometrická analýza u vybraných populací tilikvy obrovské (Tiliqua gigas) / Social interactions and morphometric analysis of populations of Blue-Tongued Skink (Tiliqua gigas)

Jachnická, Kristýna January 2018 (has links)
A Blue-tongued skink ( Tiliqua gigas) is a rare exotic species which is very popular between breeders. Nevertheless, the social structure of this charismatic skink remains almost unknown. Because of its high aggressive- ness and difficulties connected with study in its natural habitat, experiments based on the odor discrimination looks like a good alternative for its bet- ter understanding. Our results revealed that the reaction on the odor is generally poor and is very individual. We observed the highest response of interest on odors produced throught dorsal parts of skin. The reaction on conspecific's odor did not lead to escape behavior. Behavioral analysis was complemented by morphological analysis of heads in T. gigas and T.scincoides. These species are divided into separate subspecies, which are formed by geographically distinct populations. We wondered whether it is possible to separate these populations by geometric morphometrics and whether this separation is consistent with phylogenetic studies. We found out that if the populations are united in bigger groups based on their congeniality they seem to be distinct according to the head shape. Our results also revealed the monomorphy in head shape. Unfortu- nately, it is very difficult to distinguish between sexes due to the absence of sexual dimorphism....
180

The investigation of craniofacial variation between archaic and intermediate-late periods of Chile using morphometric analysis

Getler, Anna Elizabeth 20 February 2021 (has links)
In skeletal studies of prehistoric populations of Chile’s semiarid north, it is common practice for physical anthropologists to visually categorize crania as dolichophallic and brachycephalic which are then attributed to cultures or time periods based on the observed shape. The validity of this classification is still debated and poses several questions regarding the prehistory of Chile. The goal of this study is to investigate the craniofacial variation in populations representing the Archaic period and Intermediate-Late periods of Chile’s semiarid north using morphometric analysis. The samples comprise two collections from the Museo Arqueologico de La Serena in La Serena, Chile. The Archaic period dates from 10,000 BC to 300 AC. The Intermediate-Late period dates from 900 AC to 1500 AC. The Archaic period included 87 crania, while the Intermediate-Late period included 78 crania. Cranial vault modification was practiced in all prehistoric populations, and modified individuals comprise ~4.6% of the Archaic period sample and ~74.4% of the Intermediate-Late period sample. Individuals observed to be dolichocephalic are associated with the Archaic period, while brachycephalic individuals are associated with the Intermediate-Late period. Previous studies have shown that individuals with intentional cranial modification, annular and tabular, exhibit predictable changes in the craniofacial complex due to compensatory growth and shape changes related to peripheral structures of the cranial vault. A form of tabular modification is seen in both periods included in this sample, with the Intermediate-Late period sample being dominated by this modification. All craniometric landmarks were recorded using a Microscribe™ 3D digitizer, with exclusion of mandibular landmarks. MorphoJ was utilized to analyze the geometric morphometric data. Coordinates using the Microscribe were recorded in order to investigate the differences in shape of the craniofacial complex between the two samples. Two separate analyses were performed, one with all landmarks recorded and one excluding landmarks prosthion, alveolon, ectomolare and zygion. The results of both Canonical Variate analyses and associated Mahalanobis Distance values (2.699 and 2.9316) indicates statistically significant differences (p<0.001) between the two samples. It is also evident that shape changes along CV1, increases in minimum frontal breadth, upper facial breadth, and nasal height, correspond with characteristics associated with brachycephalism and tabular cranial vault modification. The large range of variation of the Intermediate-Late period sample is speculated to be a result of multiple small populations moving toward the coast possibly due to a change in climate. These small populations exhibited various morphologies which were influenced by nonrandom environmental factors. The Mahalanobis distances of the different cultural groups also indicate statistically significant differences. This method has the potential to be used in conjunction with others to identify cultural context and significance of remains in archaeological contexts in Chile. In the event of repatriation acts this method could also be used to attribute individuals to corresponding cultures and be donated to the appropriate community or facility.

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