The primary purpose of this study is to determine stability boundaries (interaction curves) for a three degree of freedom, shallow arch model under multiple dynamic loads. The model consists of four rigid bars connected by frictionless pins, with rotational springs and dashpots at the three interior joints, and a translational spring at the right hand exterior joint. Three independent loads (P₁, P₂, P₃) are applied to the model, one at each of the three interior joints. The model's equations of motion, which are derived from Lagrange's equations of motion, are numerically integrated, using the Newmark-Beta method (β = 1/4), to determine the buckling loads. The buckling loads are those loads for which the buckling criterion, the end bars simultaneously below the horizontal, is satisfied. The interaction curves and buckling loads are determined for a parabolic arch with damping under step loads, a parabolic arch without damping under step loads, an eccentric arch without damping under step loads, a parabolic arch without damping under impulse loads, and an / Master of Science

The motion of a shallow arch subjected to random loading is investigated. It is expected that the arch will vibrate about its initial stable configuration under low intensity loading, but will snap back and forth about its horizontal axis under high intensity loading. The parameter of interest is the time of first snap-through of the shallow arch under random load. This is defined as the time taken for the arch to snap to the other side of the horizontal axis. The statistics of the time to first snap-through, such as the mean time to failure as well as its probability distribution. are determined. Most of the work treats one response mode. In the first part of the study, the critical random loading for dynamic snap-through of the shallow arch was investigated using the method of computer simulation. The random excitation was assumed to be a stationary white-noise process. The primary object was to determine the critical power spectral density parameter of the random excitations. The vanishing or diminishing of the average frequency of snap-through was used to estimate this parameter. An exact value of the critical random loading parameter could not be obtained using this criterion since it was based on numerical integration of the non-linear equation of motion and computer simulation which is expensive and time-consuming. However, the critical value or range of critical values of intensity of random excitations could be estimated with a reasonable degree of accuracy. The second part of the study dealt with the first-passage problem. The exact solution of the first-passage problem is available for only a limited class of problems. In this study, the solution was obtained using numerical approximation techniques and computer simulation. For an oscillator subjected to white noise, the displacement and velocity process are governed by the Fokker-Planck-Kolmogorov (FPK) equation. The finite difference method was used to solve the derived FPK equation of the energy envelope of the equation of motion of the arch subjected to white-noise excitation. Solutions were obtained in terms of the mean time to failure, and the probability distribution function of the time to failure. A computer program for the Monte Carlo simulation of the response of the arch subjected to random loads was also developed. A large number of records of the random excitations were simulated and these were used as input in the numerical integration of the equation of motion. The Runge-Kutta method was used to obtain the time history of the displacement response, and the time at which the response exceeded the critical threshold was recorded. Statistics of the time to first snap-through were obtained and these were then used to select an empirical distribution model for the first-passage time. The results of the approximate analysis were compared with those from the simulation. Results of both methods were in close agreement. The effect of including more than one mode in the equation of motion was also studied. Multi-mode approximations of up to four modes were considered in the analysis. It was found that the results of the multi-mode approximations are significantly different from the one-mode approximation. The effect of nonstationary random excitation on the time to first snap-through was also investigated using computer simulation. / Ph. D.

Le développement cranio-facial est un processus complexe qui implique interactions tissulaires et différenciations cellulaires. La façon dont ces processus sont coordonnés lors de l'embryogenèse reste évasive. Perturber ce développement coordonné provoque un large éventail de malformations. Afin de trouver de nouveaux gènes impliqués dans le développement de la tête, un criblage phénotypique a été réalisé par mutagenèse. L'une des lignées de souris obtenues montre des malformations au niveau des arches pharyngées (AP), qui sont les précurseurs de la tête. Ces mutants meurent à mi gestation, due à des problèmes vasculaires. La mutation ponctuelle générée a été localisé dans le gène Mortalin. Mon travail de thèse vise à comprendre comment Mortalin contrôle le développement embryonnaire. Mortalin est exprimée de manière ubiquitaire, puis son expression augmente au niveau des AP, dans les tissus musculaires et nerveux. Pour déterminer les mécanismes moléculaires affectées chez ce mutant, un profil d'expression génique a révélé l'induction de gènes impliqués dans la réponse au stress du réticulum endoplasmique (RE), appelée UPR, dont le rôle est de rétablir l'homéostasie du RE. Mortalin est impliqué dans le contrôle de l'UPR en interagissant avec BiP, un régulateur direct de cette voie. L'activation soutenue de l'UPR entraîne l'apoptose, ce que nous observons chez nos mutants. De plus, l'analyse du cycle cellulaire indique que la phase S est plus longue chez le mutant, suggérant que Mortalin régule le cycle cellulaire. Ainsi, l'ensemble des données suggère que Mortalin est nécessaire pour la survie des cellules au cours du développement. / The development of the head is a complex process that involves tissue interaction and cellular differentiation. Precisely how these processes are coordinated during embryogenesis remains elusive. Disruption of this coordinated development causes a wide range of malformations. In order to find new genes involved in the development of the head, a phenotype-driven ENU screen was performed. One of the mouse lines generated exhibits small pharyngeal arches (PAs), which are the main precursors of the head. Mutant embryos die around mid-gestation, most likely as a result of defective vasculature. We mapped the ENU-mediated point mutation within Mortalin. My thesis work aims to understand how Mortalin controls embryonic development. Mortalin is ubiquitously expressed before mid-gestation. Then its expression increases in the PAs and cranial ganglia. In older embryos, mortalin is expressed in muscle and nervous tissue. To determine which molecular mechanisms are affected in the mutant, gene expression profil revealed the induction of genes involved in the response to endoplasmic reticulum (ER) stress, called UPR. The role of the UPR is to restore homeostasis in the ER. I found that Mortalin regulates the UPR by interacting with BiP, a direct regulator of this pathway. Sustained activation of UPR leads to apoptosis, which is observed in our mutant. Cell cycle has been analyzed to investigate the cause of the reduced embryonic size in our mutant. The length of the S phase was found longer in the mutant, indicating that Mortalin also regulates cell cycle. All together, these data suggest that Mortalin is required for cell survival during development, in part by controlling the UPR.

No presente estudo foi examinado em detalhe a anatomia da musculatura dorsal dos arcos branquiais de 70 espécies, pertencentes a 64 gêneros, representando todas as famílias atualmente reconhecidas de Characiformes. Um total de 22 músculos foram descritos e documentados para cada espécie examinada, e com base nas variações observadas foram propostos 33 caracteres exclusivos da musculatura dorsal dos arcos branquiais. De modo geral, muitos dos estados de caracteres observados estão amplamente distribuídos em espécies representantes de diversas famílias, variando muitas vezes em representantes da mesma família, com um número menor de caracteres restritos a alguns táxons. Uma análise filogenética incluindo apenas os caracteres de musculatura dorsal dos arcos branquiais resultou em 18829 cladogramas igualmente mais parcimoniosos (157 passos, IC=16 IR=34) com consenso estrito muito pouco resolvido devido não só ao reduzido número de caracteres em relação ao número de táxons, mas também há grande incongruência na distribuição dos estados de caracteres. Contudo, a discussão da variação observada neste complexo anatômico, em um contexto filogenético, tomando por base hipóteses já disponíveis na literatura sobre relações de parentesco na ordem Characiformes evidencia a presença de caracteres que corroboram a hipóteses baseadas em outros complexos de caracteres, em diversos níveis supraespecíficos / In the present study the anatomy of the dorsal gill-arch muscles of 70 species, comprising 64 genera, representing all currently recognized families of the Characiformes was examined in detail. A total of 22 muscles were described and documented for each examined species, and based on the variation observed 33 characters of the dorsal musculature of the gill arch were proposed. Overall, many of the observed character states are widely distributed across species in different families, and in many instances they vary within a single family, and a smaller number of characters states restricted to a few taxa. A phylogenetic analysis including only characters derived from the dorsal gill-arch musculature resulted in 18829 most parsimonious cladograms (157 steps, CI=16 RI=34), with a poorly resolved strict consensus, due not only to the reduced number of characters relative to the number of taxa, but also to the high level of incongruence in the distribution of characters states. However, the discussion of the variation observed in this anatomical complex, in the context of hypotheses available in the literature about phylogenetic relationships within the Characiformes, highlights the presence of various character states from the dorsal gill arch muscles that corroborate hypotheses based on different character complexes, at various supraespecific levels within the order

In the past few decades, there are quite a number of Pai-fangs built in the indigenous villages of the New Territories in Hong Kong and the number appears to be on the rise. The phenomenon of having so many pai-fangs in NT indigenous villages in Hong Kong could not be coincidental. They must be built as a result of some negotiation among different stakeholders – the villagers must agree, or at least do not object to the erection of pai-fang in their neighborhood; the government must also agree as they very likely take up government land and many different government departments need to be involved to build the structure. Pai-fang (牌坊) (literally archway) is a traditional form of Chinese architecture that is a physical gateway to a village. In the past few decades, there were quite a few pai-fangs built in the indigenous villages of the New Territories (NT)1 in Hong Kong and the number appeared to be on the rise. This kind of architecture neither provides physical accommodation for living or storage nor do they provide temporary shelter like a pavilion. In addition, the pai-fangs in Hong Kong are not aesthetically distinguished, especially when compared with those in Chinatowns or in the tourism spots in other countries. Nonetheless, they are increasingly popular in the NT indigenous villages in Hong Kong. It would appear that there are other reasons attributed to their origins and their increased popularity in Hong Kong other than their function or their aesthetic value. In a practical modern society like Hong Kong, when land and resource is scare, who would provide funding to build such architecture and who would find value in such architecture? The research issue is to address the phenomenon of pai-fang proliferation in the NT indigenous villages which may reflect some historical and socio-political factors in Hong Kong. Indeed, not much work has been done so far on researching pai-fangs in general in Hong Kong, not to mention research focusing on the recent trend in the increasing number of pai-fangs in the NT indigenous villages. Obviously, there is a gap in this area and this dissertation aims to cover the gap in this research by investigating into the reasons for the proliferation of pai-fang in NT indigenous villages, which may reflect some underlying historical and socio-political factors that are unique to Hong Kong. 1 For the sake of definition covered by this dissertation, the indigenous villages of New Territories exclude the indigenous villages in the Outlying Islands and New Kowloon. --------------- ------------------------------------------------------------ --------------- ------------------------------------------------------------ / published_or_final_version / Conservation / Master / Master of Science in Conservation

No presente estudo foi examinado em detalhe a anatomia da musculatura dorsal dos arcos branquiais de 70 espécies, pertencentes a 64 gêneros, representando todas as famílias atualmente reconhecidas de Characiformes. Um total de 22 músculos foram descritos e documentados para cada espécie examinada, e com base nas variações observadas foram propostos 33 caracteres exclusivos da musculatura dorsal dos arcos branquiais. De modo geral, muitos dos estados de caracteres observados estão amplamente distribuídos em espécies representantes de diversas famílias, variando muitas vezes em representantes da mesma família, com um número menor de caracteres restritos a alguns táxons. Uma análise filogenética incluindo apenas os caracteres de musculatura dorsal dos arcos branquiais resultou em 18829 cladogramas igualmente mais parcimoniosos (157 passos, IC=16 IR=34) com consenso estrito muito pouco resolvido devido não só ao reduzido número de caracteres em relação ao número de táxons, mas também há grande incongruência na distribuição dos estados de caracteres. Contudo, a discussão da variação observada neste complexo anatômico, em um contexto filogenético, tomando por base hipóteses já disponíveis na literatura sobre relações de parentesco na ordem Characiformes evidencia a presença de caracteres que corroboram a hipóteses baseadas em outros complexos de caracteres, em diversos níveis supraespecíficos / In the present study the anatomy of the dorsal gill-arch muscles of 70 species, comprising 64 genera, representing all currently recognized families of the Characiformes was examined in detail. A total of 22 muscles were described and documented for each examined species, and based on the variation observed 33 characters of the dorsal musculature of the gill arch were proposed. Overall, many of the observed character states are widely distributed across species in different families, and in many instances they vary within a single family, and a smaller number of characters states restricted to a few taxa. A phylogenetic analysis including only characters derived from the dorsal gill-arch musculature resulted in 18829 most parsimonious cladograms (157 steps, CI=16 RI=34), with a poorly resolved strict consensus, due not only to the reduced number of characters relative to the number of taxa, but also to the high level of incongruence in the distribution of characters states. However, the discussion of the variation observed in this anatomical complex, in the context of hypotheses available in the literature about phylogenetic relationships within the Characiformes, highlights the presence of various character states from the dorsal gill arch muscles that corroborate hypotheses based on different character complexes, at various supraespecific levels within the order

Abstract The influence of the X and Y chromosomes on the size and shape of the dental arches and occlusion as well as on craniofacial cephalometric dimensions, angles and dimensional ratios is studied. The material consists of Finnish patients with sex chromosome aneuploidies and normal population controls from the "Kvantti Study" series, which was collected in the 1970's and 1980's at the Institute of Dentistry, University of Turku. The patients are five individuals with complete testicular feminization (CTF), eight 47,XYY males, and fourteen 45,X/46,XX females. The controls are population female and male controls, as well as five first degree relatives of the individuals with CTF, three of the 47,XYY males and nine of the 45,X/46,XX females studied. Dental arch dimensions and occlusion as well as craniofacial cephalometric dimensions, angles and dimensional ratios are measured from dental study casts and standardized lateral cephalograms. The results show that the presence of the Y chromosome in 46,XY females and the supernumerary Y chromosomal gene(s) in 47,XYY males result in the enlargement of the dental arches and craniofacial dimensions without substantial effects on dimensional ratios and plane angles, but with special influence on the growth of the mandibular corpus. The reduction of X chromosomal genetic material in 45,X/46,XX females results in the reduction of craniofacial dimensions, affecting dimensional ratios and especially plane angles of the cranial base.

Polish composer Hanna Kulenty (1961- ) is considered a doyen among twenty-first century composers. Her compositions span over 30 years and comprise a wide range of works including solo instrumental works, operas, small and large chamber works, orchestral works and film scores. She experiments and incorporates various post-tonal era elements and devices into her compositions, often creating permanent tension and extreme emotional intensity. This study provides a detailed biography of Kulenty, a brief discussion pertaining to the development of music during the tonal and post-tonal eras and investigates Kulenty's approach to key musical traits (including melody, rhythm and harmony) in the selected string ensemble works in order to determine her musical idiom. Furthermore, this study serves as an essential reference for Kulenty's string quartets and quintet composed between 1984 and 2013. A style transformation pertaining to the selected string ensemble works is discussed. In her early compositions, Kulenty made use of 'polyphony of arches' comprising layers of arches within a large arch structure. Her more recent contributions make use of a single arch moving through different time dimensions, referred to as 'polyphony of time dimensions'. Ultimately, this study serves as a primary foundation for researchers who wish to investigate and discuss any stylistic aspects of the composer's oeuvre. / Mini Dissertation (MMus)--University of Pretoria, 2017. / Music / MMus / Unrestricted

Campground use in our national parks is increasing yearly, but little quantitative data are available concerning the impact this use is having on the ecology of the campground and surrounding area. This paper reports on some of the effects of campgrounds on small mammal populations in Canyonlands and Arches National Parks, Utah. Data collection consisted of live-trapping from April to November, 1975 (12,337 trap-nights). The populations of Ordls kangaroo rat (Dipodomys ordii), antelope ground squirrels (Ammospermophilus leucurus), deer mice (Peromyscus spp.), woodrats (Neotoma spp.), Colorado chipmunks (Eutamias guadrivittatus), and desert cottontails (Sylvilagus audubonii) inhabiting campgrounds were compared with non-campground control areas. Squaw Flat campground in Canyonlands National Park contained significantly higher populations of woodrats and Colorado chipmunks than the control. Devills Garden campground in Arches National Park exhibited significantly higher populations of deer mice, but a lower population of woodrats than the control. No significant difference was found between campgrounds and control areas for all other species. Occurrence of species in the campground and control areas was identical.

Arches National Park, located in southeastern Utah, lies in a transition zone between the southwestern hot desert and the western cold desert, but it is floristically most similar to the hot desert. The major plant communities are as follows: Juniper-pinyon, blackbrush, grasslands and sand dune association. Other community types occur but occupy very limited areas. All of the communities studied have a high degree of uniqueness and merit recognition as separate entities. Blackbrush showed the greatest overall similarity to other communities and was most similar to the sand dune communities. The hanging gardens were the most distinctive and covered the smallest area of the communities present in the Park. Cluster analysis placed blackbrush, sand dunes and juniper-pinyon on the xeric end of a moisture gradient and streamsides and hanging gardens on the mesic end.