The southern African species of the Aradidae subfamily Carventinae are revised, resuhing in the recognition of 7 genera, 24 species and 10 subspecies (excluding the nominal ones). Of these, 4 genera, 18 species and 10 subspecies are described as new. A neotype is designated for Dundocoris natalensis. Keys to the genera and species are given. Scanning electron photomicrographs of the dorsal and ventral aspects and external genitalia are provided for all the species. The cytogenetics of the group are discussed and idiograrns, based on chromosome area measurements, and photomicrographs of meiotic stadia (mostly metaphase I and metaphase II) are presented for all but one species. The chromosome numbers of the species vary between 2n = 7XY1Y2 and 2n = 32XY and XY, X1X2Y and XY1Y2 sex chromosome systems occur. Muhiple sex chromosome systems that originated from autosome-sex chromosome fusions are described for the first time in the Heteroptera. A unique case where two homologous autosomes have fused with the X- and Y -chromosomes respectively, is reported. Karyotype evolution and the origin of the different chromosome numbers are discussed and hypotheses presented. Pseudoploidy, fusions and to a lesser extent fragmentation, have played the major role in the karyotype evolution of the Carventinae. The cytogenetics of the other subfamilies of the Aradidae are briefly discussed and illustrated. It is argued that the ancestral chromosome number for the Carventinae and Aradidae (and therefore also the Pentatomorpha) is 2n = 14XY. The morphological and cytogenetic data are integrated in the classification of the Carventinae and several of the subspecies are based on chromosome number differences. The homeostatic genetic species concept is proposed and its application to the Carventinae is discussed. Phylogenies for the genera and species are proposed. The text is accompanied by more than 540 figures and more than 60 tables. / Thesis (DPhil (Entomology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted

The cichlid fish Pseudocrenilabrus philander is widely distributed in southern Africa. Many of the populations occur in small, insular, geographically isolated water bodies, some of which are in arid areas. These small allopatric populations have been isolated for thousands of years and gene flow between them is non-existent or severely restricted. Populations were found to be different in terms of coloration, size of individuals, sexual dimorphism and behaviour. This thesis involved the determination of the taxonomic status of these isolated populations, from a morphological point of view. This has been part of a larger project, involving genetic and behavioural studies, to determine whether the different populations are geographic races of a single species, or whether they are species. Heritability of the observed differences was tested by breeding through three generations under uniform laboratory conditions. The populations from which wild-caught individuals were drawn could be identified on the basis of colour. There were some differences in anatomy between populations, but none of these were entirely distinctive for a particular population. When bred under laboratory conditions, populations did not show a tendency towards uniformity, as would be expected if morphological differences were environmentally induced. However, there were slight changes in the oral and pharyngeal bone form which may be diet related. Although there are morphological differences between populations and between wild-caught and laboratory-bred populations, it is suggested that the populations of P. philander are not fully differentiated and thus in the stages of incipient speciation. other studies on P. philander have introduced an element of uncertainty in that they show different results. Behavioural work suggests that different populations would behave as different species if they were to become sympatric. Karyological and mitochondrial studies showed that there were no differences between populations. Protein electrophoresis showed that populations were genetically unique. Since the various species and subspecies of Pseudocrenilabrus have been based on morphological criteria, the approach and conclusions in this study are based entirely on morphological criteria. These studies have practical implications for conservation, as some of the small populations are threatened with extinction. If the differences between the populations were ecophenotypic (i.e. related to their environment), then threats to some populations would not affect the conservation status of the species as a whole. If, however, such differences were genetic (i.e. the populations have evolved separately), then the extinction of small, isolated populations could mean the loss of actual species. This study strongly suggests that populations are incipient species and thus should be conserved.

Deforming a complex generic shape into a representation of another complex shape is investigated. An initial study is done on the effect of cranial shape variation on masticatory induced stress. A finite element analysis is performed on two different skull geometries. One skull geometry has a prognathic shape, characterised by jaws protruding forward, while the other has a non-prognathic form. Comparing the results of the initial nite element analyses, the effect of an undesired variation in shape and topology on the resulting stress field is observed. This variation in shape and topology can not be attributed to the cranial shape variation that is investigated. This means that the variation in the masticatory induced stress field that is due to the relative degree in prognathism can not be quantified effectively. To best compare results, it would be beneficial to have a computational domain for the different skull geometries that have one-to-one correspondence. An approach to obtain a computational domain that represents various geometries with the exact same mesh size and connectivity between them does exist. This approach involves deforming a generic mesh to represent different target shapes. This report covers an introductory study to register and deform a generic mesh to approximately represent a complex target geometry. Various procedures are investigated, implemented and combined to specifically accommodate complex geometries like that of the human skull. A surface registration procedure is implemented and combined with a feature registration procedure. Feature lines are extracted from the surface representation of each skull as well as the generic shape. These features are compared and an initial deformation is applied to the generic shape to better represent the corresponding features on the target. Selective feature preserved elastic surface registration is performed after the initial feature based registration. Only the registration to surfaces of featureless areas and matched feature areas are allowed along with user selected areas during surface registration. The implemented procedures have various aspects that still require improvement before the desired study regarding prognathism's effect on masticatory induced stress could truly be approached pragmatically. Focus is only given to the use of existing procedures while the additional required improvements could be addressed in future work. It is however required that the resulting discretised domain obtained in this initial study be of sufficient quality to be used in a finite element analysis (FEA). The implemented procedure is illustrated using the two original skull geometries. Symmetric versions of these geometries are generated with a one-to-one correspondence map between them. The skull representations are then used in a finite element analysis to illustrate the appeal of having computational domains with a consistent mapping between them. The variation in the masticatory induced stress field due to the variation in cranial shape is illustrated using the consistent mapping between the geometries as part of this example. / Dissertation (MEng)--University of Pretoria, 2011. / Mechanical and Aeronautical Engineering / unrestricted

The taxonomy of Fusarium species has been controversial. The controversy surrounding the morphology-based classification, as well as the limitations and advantages of the various tools used to circumvent this problem are discussed as an introduction to the research presented in this thesis. Emphasis in this case was on the F. oxysporum species complex. The body of the research focuses on Fusarium species in Ethiopian agriculture about which little has been published. Results from this study suggest that F. oxysporum and F. solani are the two species most commonly isolated from agricultural soils and plant tissues from Ethiopia. The Ethiopian F. solani isolates were further characterized using AFLPs which showed that these isolates group into two separate clusters. Additional characterization using EF-1á sequence analyses showed that all these isolates belong to one of the three clades previously designated for the F. solani-Nectria haematococca species complex. Nine SSR markers were developed for studying the F. oxysporum complex. These markers are highly polymorphic and should be useful for many different population genetic studies of the F. oxysporum species complex. Ethiopian F. oxysporum isolates, and F. oxysporum isolates obtained from other fungal collections, were characterized using AFLPs, SSRs and DNA sequence analyses. These studies resolved the isolates into three concordant groups that corresponded to the three clades of F. oxysporum previously designated for this species complex. Most of the Ethiopian isolates grouped in one of these three clades. This and the high degree of AFLP- and SSR-based genetic similarity observed among the Ethiopian isolates suggested that these isolates are largely clonal. In addition, a PCR-based diagnostic was developed to allow for the accurate differentiation between F. oxysporum and F. redolens which has proved to be difficult using morphological characters. The studies presented in this thesis contribute to a better understanding of Fusarium species commonly found in Ethiopia. Clearly, there is much that will still need to be done. The research presented in this thesis establishes a foundation for other studies and also provides a stimulus for further studies of these important fungi in Ethiopia. Copyright 2006, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bogale, MA 2006, Molecular characterization of Fusarium isolates from Ethiopia, PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-11072006-172206 / > D87/ag / Thesis (PhD)--University of Pretoria, 2007. / Genetics / Unrestricted

No description available.

Shippagan Gully is a highly dynamic tidal inlet located on the Gulf of St-Lawrence near Le Goulet, New Brunswick. This tidal inlet is highly unusual due to the fact that the inlet has two open boundaries with phase lagged tidal cycles that drives flow through the inlet. Over the past few decades, the shipping activities through the inlet have been threatened due to the narrowing of the navigation channel caused by deposited sediment on the east side of the channel. Many engineering projects have been undertaken at Shippagan Gully in order to try and mitigate the deposition problem. However, these attempts have either been unsuccessful or the engineered structures have deteriorated over the years. This study uses the CMS-Flow and CMS-Wave numerical models to provide guidance concerning the response of the inlet to various potential interventions aimed at improving navigation safety.

Nucleation is a key step in the crystallisation process, where a new crystalline solid phase is created from a supersaturated solution. The applications of crystallisation as a purification and separation technique span many industries, yet still no definitive molecular mechanism for nucleation exists. This PhD is part of a critical mass research project involving researchers from both the Universities of Manchester and Leeds. The aim is to reveal the relationship between structural components of the nucleation transition state, solution phase molecular self-assembly and nano cluster formation, through to critically sized crystalline nuclei which then grow to crystals. All work has been carried out on a small organic molecule, p-aminobenzoic acid (PABA). This PhD has delivered successful characterisation of PABA in the solid and solution state, along with a detailed understanding of its nucleation kinetics and growth rates from a range of solvents. PABA has two enantiotropically related polymorphs, α and β, with the former constructed of carboxylic acid dimers and the latter of a hydrogen bonded tetramer network linking alternate acid and amine functionalities. New determinations of the crystal structures of both forms were submitted to the CCDC with Ref codes of AMBNAC07 and 08 for α and β PABA respectively. A detailed morphological study on both forms of PABA employing modelling and experimental methods has revealed the effect of solvent on the growth habit. In all polar solvents, α PABA displays a more important or slower growing (002) face than the calculated morphology implies. In water, β PABA has a much smaller (101 ̅) face in comparison to β PABA grown from alcohols. Crystallisation experiments demonstrate a clear solvent effect on the appearance of the two polymorphs. From organic solvents only α PABA is obtained, from water both α and β PABA are crystallised. A database search (CCDC) suggests that water may play an important role in the stabilisation of the nucleation transition state for both α and β PABA. This is not possible in organic solvents. Detailed nucleation and crystal growth kinetics have been measured for α PABA at 20°C in water, acetonitrile, ethyl acetate and 2-propanol. A clear solvent trend was observed in both the derived rates of molecular attachment and crystal growth. These were fastest in water, followed by acetonitrile, then ethyl acetate and finally slowest, in 2-propanol. This can be explained by the solvation of the carboxylic acid functional group, where 2-propanol is deemed the most effective solvator of building units in solution and on a crystal surface. This conclusion is supported by the solution FTIR spectroscopy, which clearly confirms strong solvation.

A study of the digestive tract of the copepods Tigriopus californicus and Calanus plumchrus was carried out using techniques of light and electron microscopy. In Tigriopus californicus, the foregut contains a curved cuticle lined esophagus which extends from the ventral mouth to the junction of the anterior midgut and midgut caecum. The noncuticulized portion of the digestive tract consists of: 1. A single spherical midgut caecum located anteriorly, 2. An anterior midgut, 3. A posterior midgut. There are cuticulized anterior and posterior hindgut regions ending in a dorsal anus. In Calanus plumchrus, the foregut consists of a cuticle lined esophagus extending from the ventral mouth to the junction of the midgut and the midgut diverticulum. The noncuticulized portion of the digestive tract consists of: 1. A single midgut diverticulum, 2. A midgut that is divisible on the basis of epithelial cell type and function. There is a long abruptly narrowing cuticle lined hindgut ending in an anus. In Tigriopus californicus, four cell types could be distinguished and from such ultrastructural characteristics as the position in the digestive tract, abundance, position, and type of organelles, lipid content, presence and type of vesiculation, and electron density, functions for the cells were determined. Cell type '1' is an embryonic 'stem' cell. It functions as a replacement cell and differentiates when cells are worn away or lost in secretion. Cell type '2' is mainly a secretory cell and functions in the synthesis of proteins. It also plays a role in lipid absorption. Cell type '3' is absorptive, mainly for lipids. Cell type M1, found only in the anterior midgut is also an absorptive cell. The presence of electron dense vesicles suggests that lipid absorption is not its major function. From the abundance of cell type and from examination of the ultrastructure in the various regions of the digestive tract, the following conclusions were made: 1. The midgut caecum functions in the absorption of digested nutrients. 2. The anterior midgut plays a role in nutrient absorption but is important in secretion. 3. The posterior midgut cells are mainly absorptive. In Calanus plumchrus, five cell types could be distinguished. Cell type 'E' is an undifferentiated 'stem1 cell. Cell type 'R' found in the midgut diverticulum and posterior midgut regions, is absorptive. Its developed basal surfaces suggest a transport function between the cell and the haemo-coel . Cell type 'D' is found in the glandular region of the midgut and is absorptive. It has an ultrastructure similar to that observed for cell type 'R'. Cell type 'B' is a large vacuolated absorptive cell found in the glandular region of the midgut. Cell type 'F' functions in the synthesis and secretion of digestive enzymes. In Calanus plumchrus, the midgut diverticulum is specialized for the absorption of digested nutrients and transport of metabolites to the haemocoel . The anterior midgut regions are mainly absorptive. It includes a vacuolated glandular region specialized for pinocytotic absorption. In the middle section of the midgut, adjacent and posterior to the glandular region, is an area of epithelial cells specialized for secretion. The posterior midgut regions are mainly absorptive. In Tigriopus californicus biological markers can be used to determine cell type function in correlation with the observed ultrastructure. / Science, Faculty of / Zoology, Department of / Graduate

Orientador: William Dias Belangero / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-07T16:51:12Z (GMT). No. of bitstreams: 1 CamargoFilho_JoseCarlosSilva_D.pdf: 2089342 bytes, checksum: 98e83cf09fcabd91298418b119d182a5 (MD5) Previous issue date: 2006 / Resumo: O objetivo desse estudo, foi investigar qual o efeito produzido pela corrida em esteira rolante não inclinada, durante uma hora diária (cinco dias por semana), por 15, 30 e 60 dias, sobre a cartilagem hialina do joelho de ratos. Foram utilizados 30 animais, divididos em seis grupos, sendo três experimentais (GE), com cinco animais em cada grupo, submetidos à esteira correndo 585 metros, durante 60 minutos por sessão, por cinco dias por semana, e três grupos controle (GC), com cinco animais em cada grupo, não submetidos ao treinamento físico. Os animais do grupo experimental foram sacrificados após 15 (GE-1), 30 (GE-2), e 60 (GE-3) dias de seguimento. Dos 15 animais do grupo controle foram selecionados aleatoriamente sete animais, sendo dois do grupo de 15 dias e de 30 dias e três do grupo de 60 dias para as análises histológicas por microscopia óptica convencional (côndilo lateral do fêmur direito), pela lupa estereotáxica (côndilo lateral do fêmur esquerdo) e pela termogravimetria (côndilo medial do fêmur direito), segundo critérios da International Cartilage Repair Society (2002), modificado. Essas avaliações foram feitas comparando-se o grupo experimental com o grupo controle quanto à desorganização celular, presença rara ou freqüente de ¿cluster¿, mitoses, mensuração da espessura da cartilagem hialina, contagem do número de condrócitos, quantificação do conteúdo de água e aspecto da superfície articular analisadas com 16x e 32x de aumento. Todos os dados obtidos nos grupos controle e experimental foram comparados entre si utilizando-se testes não paramétricos (Prova U de Mann Whitney e teste de Kruskal Wallis) considerando-se significativo os valores de p iguais ou menores do que 0,05. Do ponto de vista histológico houve maior desarranjo celular (p=0,01), maior número de mitoses (p=0,02), maior número de condrócitos (p=0,003) e diminuição da espessura da cartilagem hialina (p=0,01) entre o controle e os animais do grupo de 60 dias. Houve tendência ao aumento do conteúdo da água no grupo de 60 dias (p=0,09) assim como redução da espessura da cartilagem e alterações da forma da superfície articular em relação aos demais grupos em todos os côndilos observados com 60 dias. Conclui-se que a atividade na esteira rolante utilizada durante 60 dias cinco dias por semana, uma hora por dia com percurso de 585 metros produziu alterações degenerativas na cartilagem hialina do côndio lateral do joelho de rato / Abstract: The effects of treadmill running on the knee hyaline cartilage was studied in rats. Thirty rats were divided in to six groups (five animals in each one). Three groups were used as control and three of them ran on the treadmill one hour a day, five days/week, for 15, 30 and 60 days. After this the animals were sacrificed. The hyaline cartilage was studied by optical microscopy (staining HE), by estereotaxic magnifying glass (magnified in 16 and 32X) and by Fourier transform infrared imaging spectroscopy. These analyses were done comparing the control group with the running group, and among the running groups with different times of exercises. In the histological analysis the grade of cellular organization in the layers of the cartilage, the frequency of the clusters and the mitoses and the number of chondrocytes was considered. The measurement of the thickness of the cartilage was done. The quantity of the water in the cartilage was evaluated by the reduction of the mass by evaporation in to 150oC, following the modified International Cartilage Repair Society score (2002). All results were analyzed by non-parametric tests, using Mann Whitney and Kruskal Wallis tests, with p < = 0,05. It was observed in histological analyses that the groups with 60 days of exercise presented cellular layers more disorganized (p=0,01), a higher number of mitoses (p=0,02) and chondrocytes (p=0,003), with hyaline cartilage thinner than the other groups (p=0,01). Besides this, there was a tendency of the 60-day group to have an increase of water content (p=0,09). The examination by magnifying glass showed that the hyaline cartilage was reduced and presented abnormalities on their surfaces. It was concluded that the exercise done by the rats on the treadmill over 60 days produced degenerative signs in the knee hyaline cartilage / Doutorado / Pesquisa Experimental / Doutor em Cirurgia

Orientadores: Florencia Cecilia Menegalli, Maria Isabel Rodrigues / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T08:01:10Z (GMT). No. of bitstreams: 1 Vissotto_FernandaZaratini_D.pdf: 6786611 bytes, checksum: dffef14262649a8cbe2a7daad1cf4d46 (MD5) Previous issue date: 2014 / Resumo: Os achocolatados em pó são formulados com a mistura de cacau, açúcar, maltodextrina e aromas, podendo conter derivados lácteos. Para se obter uma adequada reconstituição em líquidos, os achocolatados são submetidos aos processos de lecitinação (adição de um agente tensoativo: lecitina de soja) e aglomeração com vapor. Um dos objetivos desse estudo foi o de avaliar os efeitos das variáveis do processo de aglomeração com vapor (pressão do vapor, temperatura do secador rotativo, vazão de sólidos da alimentação e frequência de rotação do secador) sobre as características físicas e físico-químicas de achocolatados em pó. A aglomeração com vapor levou a um aumento do diâmetro médio de partículas, sendo mais pronunciado no produto formulado com o açúcar moído. O processo foi responsável pelo escurecimento e redução da umidade dos achocolatados, além da diminuição dos tempos de molhabilidade. Adicionalmente foi caracterizada a morfologia dos grânulos de achocolatado, obtidos em diferentes condições operacionais do aglomerador (máxima, média e mínima), utilizando os descritores de tamanho e forma. Os resultados mostraram que não existe diferença entre os descritores de forma e quanto aos descritores de tamanho verificou-se diferença entre as condições de processo para grânulos maiores que 600 ?m. Concluiu-se que os grânulos de achocolatado aglomerados apresentaram formato alongado. Foram também determinadas as transições de fase e as temperaturas de transição vítrea (Tg) de achocolatados em pó e dos seus principais constituintes. Durante a aglomeração com vapor a alta temperatura levou o açúcar moído a uma condição acima da sua Tg, passando a ser esse componente um veículo para a granulação. A Tg da maltodextrina é pequena em atividades de água elevadas (Tg= - 4,9 °C; Aa= 0,843), o que também a torna um veículo para o processo de aglomeração. No cacau em pó alcalino foi observada a fusão da manteiga de cacau (aparecimento das formas polimórficas ?v e ?). Para o achocolatado lecitinado verificou-se que a Tg aumenta com o incremento da atividade de água do meio, portanto para esse tipo de produto a água, ao ser adsorvida, não consegue interagir com o material, não sendo verificado o efeito plasticizante. Para o achocolatado aglomerado com vapor verificou-se que a Tg diminuiu com o aumento da atividade de água do meio (efeito plasticizante). A evolução do caking dos constituintes dos achocolatados mostrou que o cacau em pó apresentou baixa higroscopicidade (pequeno aumento do ângulo de repouso com o tempo), pequena formação de aglomerados e a ausência do caking. A medida da força de compressão dos agregados formados mostrou que a sacarose formou pontes mais rígidas entre as partículas que a maltodextrina. Foi também monitorada a estabilidade de achocolatados em pó lecitinados e aglomerados com vapor, estocados a 25 e 35 °C, numa umidade relativa de 84%, buscando-se simular um clima quente e úmido (região norte do Brasil). Ao longo do tempo, verificou-se aumento do ângulo de repouso e escurecimento dos produtos. O achocolatado lecitinado mostrou-se mais susceptível ao empedramento que o aglomerado, com a formação de grumos a partir do 63° dia de armazenamento / Abstract: Cocoa beverage powders consist of a mixture of cocoa, sugar, maltodextrin, flavors, and may contain dairy products. To obtain products with adequate reconstitution in liquids, the cocoa beverage powders are subjected to the processes of lecithination (addition of the surfactant soy lecithin) and steam agglomeration. One objective of this study was to evaluate the effects of the main variables of the steam agglomeration process (vapor pressure, temperature of rotary dryer, solid feed rate and dryer rotation frequency) on the physical and physicochemical characteristics of cocoa beverage powders. The steam agglomeration led to an increased average particle diameter, being more pronounced in the product formulated with granulated sugar. The process was responsible for powder darkening, reduction of the product¿s moisture and decrease in the wettability. Additionally, the morphology of the cocoa beverage powder granules was characterized in different operating conditions of the steam agglomerator (maximum, average and minimum) using the descriptors of size and shape. There were no differences between the shape descriptors and as to the size descriptors there were differences in the process conditions studied for the granules of size above 600 ?m. It was observed that the steam agglomerated cocoa beverage granules had a more elongated shape. It was also determined phase transitions and the glass transition temperature (Tg) of cocoa beverage powders and the main constituents of these products. During the steam agglomeration, the high temperature led the granulate sugar to a condition above its Tg, making this ingredient a granulation vehicle. The Tg of maltodextrin is small at higher water activities (Tg = - 4.9 °C, aw = 0.843), which makes this ingredient a vehicle for the agglomeration process. For the alkaline cocoa powder the phase transition observed is the melting of the cocoa butter with the appearance of polymorphic forms ? and ?v. For the lecithinated cocoa beverage powder, it was verified that the Tg increases with the increasing of the water activity, which leads to the conclusion that for this type of product the adsorbed water cannot interact with the material, and the plasticizing effect is not noted. For the steam agglomerated cocoa beverage powder it was observed that the Tg decreases with increasing water activity (plasticizing effect). The evolution of the caking for the constituents of cocoa beverage powders showed that the cocoa powder had low hygroscopicity (small increase of the repose angle with time), little formation of granules and the absence of caking. The measurement of the compression strength of the aggregates showed that sucrose formed bridges more rigid between the particles than maltodextrin. Stability of lecithinated and steam agglomerated cocoa beverage powders stored at 25 and 35 °C, in a relative humidity of 84%,was also monitored, in order to simulate hot and humid climates (like northern Brazil). Overtime, it was observed increase of the repose angles and products darkening. The lecithinated cocoa beverage powder was more susceptible to caking than the steam agglomerated product, with the formation of lumps from the 63th day of storage / Doutorado / Engenharia de Alimentos / Doutora em Engenharia de Alimentos