Text in English / Underlying many formal approaches to linguistics is the fundamental, philosophical assumption that categories are discrete entities. This assumption also underlies two contemporary formal approaches to morphology which seek to account for the stress and distributional properties of derivational affixes in complex words. A study of these two approaches, the level-ordering and the category distinction approaches, reveals that both are faced with the same set of counterexamples in English. Specifically, they are faced with certain derivational affixes which display uncharacteristic distributional properties. In order to deal with such affixes the approaches resort to a variety of ad hoc mechanisms whose sole purpose is to save them from refutation. The argument offered in this thesis is that the problem with both approaches lies with the background assumption about categories which underlies their work. There is, however, an alternative conception of the nature of categories that has been widely supported by experimental research in the field of cognitive psychology, viz. that categories are non-discrete or continuous entities which are distributed along a continuum. In the thesis it is argued that, by adopting this conception of categories, a more adequate account can be given of the gradient differences between category members both inter- and intra-categorially. This argument will be illustrated with specific reference to affix categories in Afrikaans. / Linguistics and Modern Languages / D. Litt. et Phil. (Linguistics)

In linguistics, words are usually considered to be composed of morphemes: units that carry meaning and are not further subdivisible. The task of this thesis is to create an automatic method for segmenting Czech words into morphemes, usable within the network of Czech derivational relations DeriNet. We created two different methods. The first one finds morpheme boundaries by differentiating words against their derivational parents, and transitively against their whole derivational family. It explicitly models morphophonological alternations and finds the best boundaries using maximum likelihood estimation. At worst, the results are slightly worse than the state of the art method Morfessor FlatCat, and they are significantly better in some settings. The second method is a neural network made to jointly predict segmentation and derivational parents, trained using the output of the first method and the derivational pairs from DeriNet. Our hypothesis that such joint training would increase the quality of the segmentation over training purely on the segmentation task seems to hold in some cases, but not in other. The neural model performs worse than the first one, possibly due to being trained on data which already contains some errors, multiplying them.

One of the most diverse groups of parasitic nematodes includes the nematodes of the suborder Trichostrongylina. Trichostrongyle systematic classification is based on the study of the anterior end, the female reproductive system, the male copulatory bursa and cuticular ridges, which make up the synlophe. These morphological characters also assist taxonomists to characterize species and assign them into one of the three superfamilies. Heligmosomoidea is the most diverse superfamily, including Viannaiidae. This family represents one of the major evolutionary radiations of trichostrongyles in South America. Members of Viannaiidae parasitize a variety of mammals endemic to the Neotropics including, but not limited to, the opossums. Viannaiids have great morphological variation in the reproductive organs of the females and the secondary sexual structures of the males (e.g., rays in the bursa). Consequently, the placement of these species in classification schemes has drastically changed over time. The prevailing taxonomy relies on the host used by the parasites as well as their geographic distribution. Viannaiidae has always included monodelphic nematodes with simple synlophes, yet it eventually included species in the genus Travassostrongylus, which the morphology is very distinct from the rest of the members of the family. Differences pertain to a greater number of ridges of the synlophe and the didelphic female reproductive system. These features are more similar to trichostrongyles in Herpetostrongylidae and Nicollinidae, which infect Australian vertebrates, the majority of which are marsupials. I herein document the diversity of this group by reporting the presence of a putative new species and use five gene regions to reconstruct the phylogeny of Viannaiidae exclusive of didelphid marsupials. I used the resulting phylogeny to test the monophyly of Travassostrongylus and Viannaia and to reconstruct the character evolution of the monodelphic/didelphic condition and the ornamentation of the cuticle. The phylogeny indicates that Viannaiidae is not monophyletic, recovering a clade with the Travassostrongylus species and trichostrongyles from Australian fauna. The tests for character reconstruction assist in determining that the didelphic condition and the presence of dorsal synlophe ridges in Travassostrongylus and Austrostrongylus may be traits inherited from a common ancestor. Furthermore, it was apparent that a character change from didelphic to monodelphic occurred in the common ancestor of the Viannaia species. This ancestor also underwent a change from a dorsal cuticle with ridges to a smooth cuticle. Though the study suggests that Viannaiidae is not monophyletic, the inclusion of more species from these genera and the viannaiids found in hystricognaths from the New World rodents will conclusively determine the affinities of the members of the family. Finally, I suggest that the relationship between the species in Travassostrongylus and the Australian parasites dates to the Gondwana landmass and that these trichostrongyles, or their ancestors, were present in the marsupials of that time period. The examination of microbiotheriids could provide more information and illuminate the factors that led to the evolutionary relationship between the parasites of America and Australia.

Pterotocrinus is an echinoderm of the class Crinoidea that is restricted to the Chesterian Series (Chestnut and Ettensohn, 1988; Sutton, 1934). The most identifiable and best preserved remains of Pterotocrinus are the wing plates (Welsh, 1978). These wing plates are specialized tegmen plates that give Pterotocrinus its name (from pteron, Greek for "wing") (Welsh, 1978). This study questions whether or not wing plates can be used for biostratigraphy throughout the Chesterian Series, as well as what the functions of the wing plates were. New morphologies of Pterotocrinus found within the Menard Limestone during this study bring into question the biostratigraphical usefulness of many of the morphologies of Pterotocrinus wing plates. Certain species of Pterotocrinus appear to remain valuable index fossils within the Menard Limestone and the Kinkaid Formation. Four new morphologies were collected within the Menard Limestone during this study. These new finds draw questions about our knowledge of this genus. This study also attempted to explain the function of the wing plate, and how it may have changed over time. Pterotocrinus wing plates evolved rapidly during the Chesterian Series developing vastly different morphologies from the time the Menard Limestone was deposited to the time when the Kinkaid Formation was deposited. This study suggests a functional shift over time, with the wing plates of the Menard Limestone acting as rudders to orient the calyx to either assist in feeding or reduce stress on the calyx, and the wing plates of the Kinkaid Formation acting as an antipredatory defense mechanism. This study presents new conclusions and new questions regarding the wing plates of Pterotocrinus.

ix, 84 leaves : ill. ; 29 cm Notes Typescript Thesis (M.S.)--University of Oregon, 2003 Includes vita and abstract Includes bibliographical references (leaves 73-84) Another copy on microfilm is located in Archives

Demon, allegory, exile, Scandinavian zombie—Grendel, the first of the monsters in the Old English Beowulf, has been called all of these. But lost in the arguments about what he means is the very basic question of what he is. This project aims to understand Grendel qua monster and investigate how we associate him with the monstrous. I identify for study a number of traits that distinguish him from the humans of the poem--all of which cluster around either morphological abnormality (claws, gigantism, shining eyes) or deviant behavior (anthropophagy, lack of food preparation, etiquette). These traits are specifically selected and work together to form a constellation of transgressions, an embodiment of the monstrous on which other arguments about his symbolic value rest.

The preferential grazing of an organism on certain particles from the environment (selective feeding) impacts particle compositions and distributions in aquatic systems. Historically, selective feeding has been examined almost exclusively through the lens of particle size. In this dissertation, I investigated size-based selection alongside particle shape, adhesive interactions, and the mechanical operation of the filter to characterize the selective-feeding capabilities of marine mucous-mesh filter-feeders (the planktonic appendicularian Oikopleura dioica and the benthic ascidians Herdmania momus and Styela plicata). I used high-speed videography to describe the feeding-filter mechanics of O. dioica and tested its capacity for size-based particle selection. I show for the first time how pulsatile flow coupled with elasticity of the filter facilitates prey detachment. Using synthetic beads, I showthat the food-concentrating filter selectively retains smaller particles because of their increased adhesion. Appendicularian houses may therefore retain particles size-selectively, which counters the historically-held assumption that appendicularians are non-selective grazers. I synthesized ellipsoidal microbeads to test the effect of particle length-to-width ratios on the capture efficiency of O. dioica and S. plicata. Both grazers retained ellipsoidal particles according to their minimum diameter. I identified the kinematic mechanism for retention patterns of ellipsoidal particles using high-speed videography and endoscopy of particle interactions with the mucous filters of O. dioica and H. momus, respectively. In the filters of both animals, ellipsoids oriented parallel to fluid streamlines and the minimum dimension of the particle intercepted the filters. I provide the first mesh-scale observations of particle capture by H. momus, show how particle shape influences hydrosol filtration by S. plicata, and suggest that ascidian filtration may not be adequately described by simple sieving.

Os sistemas de estereofotogrametria digital representam um método não radioativo, seguro, preciso e objetivo para quantificar as dimensões dos tecidos moles faciais. Novos equipamentos têm despontado como alternativa viável nas especialidades que tratam do complexo craniofacial. A estereofotogrametria se destaca pela completa ausência de radiação ionizante, alta velocidade de aquisição, grandes ângulos de visualização, navegação virtual da imagem e possibilidade de integração com outros sistemas de imagens. Quando um novo método é proposto, torna-se necessário avaliar a sua confiabilidade na obtenção de resultados. O objetivo deste estudo foi analisar a repetibilidade intraexaminador em medidas faciais lineares e angulares, em um sistema de estereofotogrametria digital utilizado para avaliação da morfologia facial. A amostra final consistiu em 30 indivíduos adultos brasileiros com idade entre 18 e 45 anos, média de 26,71± 6,53 anos. Vinte e cinco mulheres e cinco homens, saudáveis, sem histórico de traumas ou cirurgias faciais e sem anormalidades congênitas, tiveram pontos de referência marcados em suas faces por um mesmo examinador e foram fotografados em dois momentos, com intervalo de uma semana (T1 e T2), pelo sistema de estereofotogrametria digital Vectra M3® (Canfield Scientific, Fairfield, EUA). Trinta e oito pontos foram demarcados em cada captura. Identificou-se um total de 2280 pontos; 11 medidas foram feitas em cada imagem capturada e 330 medições foram realizadas. As imagens obtidas foram medidas em software próprio do sistema. A análise foi realizada a partir de um conjunto de nove medidas angulares (ângulos nasolabial, mentolabial, convexidade facial, convexidade facial total, nasal, maxilar, mandibular, nasofrontal, maxilofacial, e duas medidas lineares (altura facial média AFAM e altura facial inferior - AFAI), propostas para caracterizar a morfologia facial dos indivíduos da amostra. A repetibilidade intraexaminador na aquisição das medidas foi analisada pela Média Absoluta das diferenças (MAD), Magnitude Relativa do Erro (MRE), Erro Técnico de Medição (ETM), Coeficiente de Correlação Intraclasse (ICC) e análise de Bland-Altman. O teste t para amostras pareadas foi utilizado na identificação de erro sistemático entre T1-T2. O coeficiente de correlação de Pearson foi empregado para verificar a associação entre idade/IMC e o erro nas medições realizadas. Resultados: No cálculo do ETM e da MAD, apenas os ângulos nasolabial (2,17°) e mentolabial (2,88°) apresentaram valores maiores que 2 graus (limite clínico estabelecido para o presente estudo). Para a MRE, 9,1% das medidas foram consideradas moderadas (ângulo maxilofacial), 27,3% foram consideradas boas (ângulo nasal, ângulo maxilar, ângulo mandibular), 45,5% muito boas (ângulo nasolabial, ângulo mentolabial, ângulo nasofrontal, AFAM, AFAI) e 18,2% excelentes (ângulo da convexidade facial, ângulo da convexidade facial total.). Os ângulos nasolabial, mentolabial, convexidade facial, convexidade facial total, maxilofacial e nasofrontal apresentaram valores de ICC (R) classificados como excelentes. O ângulo nasal, e as medidas lineares de AFAI e AFAM tiveram um resultado satisfatório. Não ficou comprovada a relação entre idade/IMC e o erro encontrado entre as medições (diferença absoluta entre T1 e T2). As medidas para AFAM apresentaram um erro sistemático. As medições realizadas foram consideradas precisas dentro dos limites e referências estabelecidas para o presente estudo. Os ângulos nasolabial e mentolabial devem ser interpretados com critério pela variabilidade apresentada. O examinador apresentou boa repetibilidade nas medições realizadas. Os resultados obtidos no presente estudo acrescentam confiabilidade ao uso da estereofotogrametria digital na antropometria facial. Os parâmetros de precisão adequados a cada situação, em clínica ou em pesquisa, devem ser previamente estabelecidos. / Digital stereophotogrammetry systems represent a non-radioactive, safe, and accurate method to quantify the facial soft tissues dimensions. New equipment has emerged as viable alternative in the specialties that deal with the craniofacial complex. Stereophotogrammetry system has been highlighted by the complete absence of ionizing radiation, high-speed acquisition, large viewing angles, virtual image navigation and possibility of integration with others imaging systems. When a new method is proposed, it is necessary to assess its reliability in achieving results. The aim of this study was to analyze the intra-examiner repeatability on linear and angular facial measurements into a digital stereophotogrammetry system used to assess facial morphology. The final sample consisted of 30 Brazilian adults aged between 18 and 45 years, average of 26.71±6,53 years. Five men and twenty-five women, healthy, with no history of trauma or previous facial surgeries and without congenital abnormalities, had landmarks labeled on their faces by the same rater and were photographed in two stages (T1-T2), with an interval of one week, at stereophotogrammetry system digital Vectra M3® (Canfield Scientific, Fairfield, NJ). Thirty-eight points were labeled in each capture. 2280 points were identified; 11 distances were measured in each image, giving a total of 330 measurements. The images were measured by a dedicated software system. The analysis was performed from a set of nine angular measurements (nasolabial, mentolabial, facial convexity, full facial convexity, nasal, maxillary, mandibular, nasofrontal, maxillofacial angles, and two linear measurements (middle facial height - AFAM and lower facial height AFAI). Precision and intra-rater repeatability in the measurements acquisition were evaluated by the Mean Absolute Difference (MAD) Relative Error Magnitude (REM), Technical Error of Measurements (TEM), intra-class correlation coefficient (ICC) and Bland-Altman analysis. Test t for paired samples was used in the systematic error identification between T1-T2. The Pearson correlation coefficient was used to verify the association between age / BMI and measurement errors. Results: to the estimated TEM and MAD only nasolabial angles (2.17°), mentolabial (2.88°) had higher values than 2.0 degrees (clinical limit for this study). For MRE, 9.1% of the measures were considered moderate (maxillofacial angle), 27.3% were considered good (nasal angle, maxillary angle, mandibular angle), 45.5% very good (nasolabial angle, mentolabial angle, nasofrontal angle, AFAM, AFAI) and 18.2% excellent (facial convexity, full facial convexity.). The nasolabial, mentolabial, facial convexity, total facial convexity, maxillofacial and nasofrontal angles showed R values rated as excellent. The nasal angle, and the linear measurements of AFAI and AFAM had a satisfactory outcome. It was not proven the relation between age / body mass index and the error (absolute difference between T1 and T2). Measures to AFAM showed a systematic error. Conclusion: The measurements were considered accurate within the limits and references established for this study. The examiner showed good repeatability in identifying landmarks. The results presented on this study add reliability to the Digital stereophotogrammetry in clinical and research activities, provided there are previously established adequate precision parameters.

Despite a central role for morphological knowledge in supporting linguistic generalisation, the neural representations supporting its learning remain largely unexplored. This thesis addressed this gap by exploring the role of memory consolidation in morphological learning and generalisation. In three experiments, adult participants learned an artificial language in which stems (e.g. gleet, shiln) combined with plural affixes (e.g. –aff, -opp; gleetaff, shilnopp) to refer to the occupation of multiple male and female characters. Mimicking properties of morphological systems in natural languages, the plurals varied in their phonological consistency/ambiguity and type/token frequency. Two sets of plurals, distinguished by gender, were trained on two successive days. Experiment 1 revealed that generalisation to novel phonologically ambiguous forms measured on the second day showed a greater influence of token frequency for plurals trained on the previous day, suggesting overnight changes in their underlying representations. Experiment 2 examined this effect further by using fMRI to compare the neural representations underlying plurals learned on the day of scanning or on the previous day. Representational Similarity Analysis revealed increased similarity structure among high type frequency plurals and reduced similarity structure among high token frequency plurals following overnight consolidation in the left superior temporal gyrus (STG). These results are consistent with a Complementary Learning Systems (CLS) model in which overnight consolidation supports the development of overlapping representations among several items sharing the same feature (here, an affix; type frequency) and strengthens item-specific representations for frequently occurring items (token frequency). Additionally, connectivity analyses showed that the functional coupling between the left STG and the left dorsolateral prefrontal cortex was weaker for high type frequency plurals and stronger for high token frequency plurals following overnight consolidation. These results suggest that the engagement of prefrontal control processes in retrieving the newly-learned plurals is subject to overnight consolidation and sensitive to the similarity structure underlying the plurals to be retrieved. However, the overnight changes in similarity structure and functional networks observed in Experiment 2 were not mirrored by changes in generalisation to novel forms as were observed in Experiment 1. Experiment 3 aimed to address the discrepancy in consolidation-related changes in generalisation behaviour between the first two experiments. Type/token frequencies were manipulated to bias learning, consolidation, and generalisation towards high token frequency plurals. Despite this manipulation, no consolidation-related changes in generalisation were observed. Findings from all three experiments are interpreted in the context of the CLS model and a role for overnight consolidation in morphological learning and generalisation is discussed.

abstract: The distinguishing feature of the filamentous fungi is the hyphae - tube-like microscopic cells that exhibit polarized growth via apical extension and allow the fungus to interact with its environment. Fungi elongate at the hyphal apex, through the localized construction of new plasma membrane and cell wall through the exocytosis of secretory vesicles. One population of these vesicles have been identified as chitosomes, containing chitin synthase isoenzymes, which are responsible for the polymerization of N-acetylglucosamine from UDP N-acetylglucosamine into chitin, the primary fibrillar component of the fungal cell wall. The chitosomes, in addition to other vesicles, can be observed aggregating in the hyphal tip in most filamentous fungi. In the Ascomycota and Basidiomycota, this collection of vesicles exhibits discrete organization and has been termed a Spitzenkörper. Although accumulations of vesicles can be observed in the hyphal tip of many growing filamentous fungi, some debate continues as to what precisely defines a Spitzenkörper. This study reports the details of three separate projects: first, to document the effects of deleting a single chitin synthase, CHS-1 and CHS-6 in Neurospora crassa with regards to hyphal ultrastructure, cytoplasmic organization, and growth in comparison to the wild-type. Given the importance of chitin synthesis in fungal cell growth, deletion of a critical chitin synthase presumably impacts cell wall structure, fungal growth and cytoplasmic organization. Second, an examination of the ultrastructure of four zygomycetous fungi - Coemansia reversa, Mortierella verticillata, Mucor indicus, and Gilbertella persicaria has been conducted. Utilization of cryofixation and freeze-substitution techniques for electron microscopy has produced improved preservation of cytoplasmic ultrastructure, particularly at the hyphal apex, allowing detailed analysis of vesicle size, contents, and organization. Lastly, hyphal tip organization was reviewed in a broad range of fungi. Previous studies had either focused on a few select fungi or representative groups. Vesicle organization, composition and size do appear to vary among the classes of fungi, but some trends, like the vesicle crescent in the zygomycetous fungi have been documented. / Dissertation/Thesis / Doctoral Dissertation Biology 2015