There is a boat burial in Scar, on Sanday, Orkney that was excavated in 1991. This undergraduate thesis compares Scar with 5 other boat burials from Norway, to determine if the burial custom is uniform or if there are regional differences.  The 6 burials are presented individually and then the type and typology of the finds is compared. The conclusion is that the boat itself and the rivets in the boat burial in Scar are very similar to the burials in Norway, and there are strong similarities between the finds in Scar and the corresponding type of finds in the Norwegian burials. However, they are not uniform in their collections of finds, and this could be due to regional differences. Other potential causes, such as dating of the burials, are discussed as well.

The human body consists of a number of very complex, highly specialised organs which perform a variety of functions that are essential to life and health. One of the main functions of the skin, the largest of the human organs, is to maintain the integrity of the body. It does this by acting as a physical barrier, preventing micro-organisms and other potentially harmful substances from entering the body. When the integrity of the skin is damaged through injury, a self-protective mechanism is triggered and the reparative wound healing process begins. Under normal circumstances the wound healing process culminates in the skin recuperating its normal characteristics and functions at the site of the injury, with only a small visible mark being left behind. However, in some cases the wound healing process may become altered leading to the production of abnormal scars, such as keloids. Keloid scars are formed from scar tissue at the site of an injury, as a result of excessive tissue repair that extends beyond the boundaries of the original wound. These scars are characterised by excess collagen deposition produced during the wound healing process. It is estimated that as many as 20% of the black and Hispanic population are affected by keloid scarring. In addition to the aesthetic aspect, keloid scars can also be painful, itchy and prone to become infected. Keloid scar formation can be triggered by skin injuries caused by, for example, acne, wounds, shaving, burns, and surgical incisions. The mechanism by which keloid scars form is currently not well understood and consequently no effective treatments exist to date.This thesis describes an investigation into the mechanical properties of single keloid and normal skin fibroblast cells for the purpose of establishing if there is a quantitative difference between the two types of cells. This information will be of benefit to researchers looking for a better understanding of the keloid formation mechanism and for those seeking improved treatments. An atomic force microscope (AFM) was employed to indent single Keloid and normal skin fibroblast cells taken from five patients. Values for the apparent Young's modulus of the cells were then calculated by fitting the experimental data using Hertz's model. Apparent Young's modulus values were then compared. The findings of the analysis indicate that statistically, there is a significant difference in the Young's modulus values of normal and keloid cells, with keloid cells exhibiting substantially greater stiffness than normal skin fibroblast cells. To enable the keloid and normal skin fibroblast cells to be studied in as close to their natural, physiological environment as is possible the AFM experiments described in this thesis were undertaken in a phosphate buffered saline (PBS) solution. In such cases the use of a fluid medium presents additional complexities, not least of which is the introduction of a hydrodynamic drag force due to viscous friction of the cantilever with the liquid which can affect the experimental data obtained and consequently any material properties calculated as a result of using these data. In order to investigate the effect of dragging force on the experimental data obtained from the AFM a novel integrated finite element based model was developed. The model, described in this thesis, provides quantification of the drag force in AFM measurements of soft specimens in fluids, consequently enabling more accurate interpretation of the data obtained from AFM experimentation. The model is validated using extensive data obtained from AFM experimentation undertaken in a number of fluids of different viscosities, at a variety of tip velocities and platform-tip separations and by comparison with an existing analytical model. The novel model is shown to accurately account for drag forces in AFM in fluid media without the need for extrapolation of experimental data and can be employed over the range of tip geometries and velocities typically utilised in AFM experimentation.The work described in this thesis demonstrates that the AFM is a valuable tool that can be used to successfully investigate the mechanical properties of biological samples in fluids. It was shown that increased accuracy in the interpretation of data obtained from AFM experimentation can be obtained by taking into account the hydrodynamic drag force due to viscous friction of the cantilever with the liquid. The investigation into the mechanical behaviour of keloid cells described in this thesis significantly adds to the yet small body of research undertaken on keloid cells to date. The findings of the investigation will provide valuable information that will be of benefit in the future to researchers looking to develop effective treatments for the prevention, reduction or removal of keloid scars.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19033号 / 農博第2111号 / 新制||農||1031(附属図書館) / 学位論文||H27||N4915(農学部図書室) / 31984 / 京都大学大学院農学研究科農学専攻 / (主査)教授 米森 敬三, 教授 土井 元章, 教授 北島 宣 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

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Le complexe Scar/WAVE génère la formation des lamellipodes par l'intermédiaire du complexe Arp2/3 responsable de la polymérisation de réseaux d'actine branchés. Dans le but d'identifier de nouveaux régulateurs du complexe Scar/WAVE, nous avons conduit un crible en cellules de Drosophiles combinant une approche protéomique à une approche de génomique fonctionnelle. La chaîne lourde de la clathrine a été identifiée au cours de ce crible comme une protéine interagissant avec le complexe Scar/WAVE et dont la déplétion affecte la formation des lamellipodes. Ce rôle de la clathrine dans la formation des lamellipodes peut être découplé de son rôle classique dans le transport vésiculaire en utilisant différentes approches. De plus, la clathrine est localisée au lamellipode en l'absence d'adapteurs et des protéines accessoires de l'endocytose. La surexpression de la clathrine affecte le recrutement membranaire du complexe WAVE réduisant ainsi la vélocité des protrusions membranaire et la migration cellulaire. Par opposition, lorsque la clathrine est envoyée artificiellement à la membrane plasmique par une fusion à une séquence myristoylée, on observe une augmentation du recrutement membranaire du complexe Scar/WAVE, de la vélocité des protrusions membranaires et de la migration cellulaire. L'ensemble de ces résultats montrent que la clathrine envoie le complexe Scar/WAVE à la membrane plasmique et donc contrôle la formation des lamellipodes en plus de son rôle plus classique dans le traffic membranaire. / The Scar/Wave complex (SWC) generates lamellipodia through Arp2/3-dependent polymerization of branched actin networks. In order to identify new SWC regulators, we conducted a screen in Drosophila cells combining proteomics with functional genomics. This screen identified Clathrin Heavy Chain (CHC) as a protein that binds to the SWC and whose depletion affects lamellipodium formation. This role of CHC in lamellipodium formation can be uncoupled from its role in membrane traffic by several experimental approaches. Furthermore, CHC is detected in lamellipodia in the absence of the adaptor and accessory proteins of endocytosis. We found that CHC overexpression decreased membrane recruitment of the SWC, resulting in reduced velocity of protrusions and reduced cell migration. In contrast, when CHC was targeted to the membrane by fusion to a myristoylation sequence, we observed an increase in membrane recruitment of the SWC, in protrusion velocity and in cell migration. Together these data suggest that CHC brings the SWC to the plasma membrane, thereby controlling lamellipodium formation, in addition to its classical role in membrane traffic.

La gale bactérienne des Solanées à graines est une maladie répandue dans la plupart des aires de production de tomate et des Capsicum spp. (piment, poivron) du monde. Elle est très sévère dans les régions tropicales et subtropicales et sa présence est récurrente dans la région Sud-Ouest de l’océan Indien. Cette maladie est complexe car cinq taxons sont actuellement reconnus comme agents causaux, X. vesicatoria , X. perforans , X. gardneri , X. euvesicatoria et X. campestris pv. raphani . Néanmoins certaines études récentes suggèrent des synonymies de certaines de ces espèces entre elles et également avec d’autres Xanthomonas. Les objectifs principaux de la thèse étaient (1) l’analyse de la diversité sur une collection mondiale à l’aide des deux techniques moléculaires à haut débit, AFLP et MLSA, avec un accent particulier sur la diversité génétique et pathologique régionale (2) la description des relations phylogénétiques entre ces taxons et les autres Xanthomonas (3) la mise au point d’un outil d’identification rapide qui tienne compte de la diversité de l’agent pathogène et basé sur des marqueurs SCAR identifiés par AFLP. Une absence de congruence entre les topologies d’arbres dérivées des séquences de 4 gènes de ménage étudiés a été mise en évidence, de même que plusieurs évènements de recombinaison sur trois d’entre eux. Un inventaire des espèces trouvées dans les îles SWIO a pu être dressé, mettant à jour une grande diversité dans cette région. Nos données ont confirmé de fortes similarités génétiques entre X. alfalfae , X. euvesicatoria et X. perforans d’une part et de X. cynarae et X. gardneri d’autre part, qui ont probablement le statut d’espèces-synonyme. / Bacterial spot of Solanaceae is present in most areas of the world where tomato and pepper are cultivated. Its incidence is especially high in tropical and subtropical regions, such as the islands of South West Indian Ocean. This desease can be caused by five taxa: X. vesicatoria , X. perforans , X. gardneri , X. euvesicatoria et X. campestris pv. raphani, but recent studies suggest that some of those species are synonymous or actually correspond to other species of Xanthomonas. The objectives of this work were (1) to assess the genetic diversity of a word collection of strains using two high throughput molecular techniques: AFLP and MLSA; (2) to describe the phylogenetic relationships between the different taxa caising bacterial spot and other Xanthomonas; (3) to develop a rapid identification method based on SCAR markers identified by AFLP, which would take into account the global diversity of the pathogen. Tree topologies derived from the sequences of four housekeeping genes were not congruent and recombination events could be detected in three of them. A survey of bacterial spot of tomato and pepper in the South West Indian Ocean showed a broad diversity of the species causing this disease in the region. Our data confirmed the strong genetic similarity between, X. alfalfae , X. euvesicatoria et X. perforans, as well as between X. cynarae and X. gardneri, which are probably synonymous species.

Made available in DSpace on 2014-06-11T19:32:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-08Bitstream added on 2014-06-13T19:42:47Z : No. of bitstreams: 1 costa_mm_dr_jabo.pdf: 539143 bytes, checksum: 38e4165c8bd5de4a8cf35184bd7ea3a7 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A seleção assistida por marcadores moleculares têm contribuído com os estudos para o desenvolvimento de cultivares resistentes. Os ganhos mais evidentes podem ocorrer em doenças como a ferrugem asiática da soja, onde a alta variabilidade do patógeno e a busca por novas fontes de resistência têm dificultado o sucesso dos melhoristas. Assim, os objetivos deste trabalho foram estudar a herança da resistência à ferrugem em diferentes fontes e desenvolver marcadores SCAR ligados a um loco de resistência para seleção assistida. Populações F2 oriundas dos cruzamentos PI 459025 x CD 208 (1), PI 200526 x CD 205 (2), PI 200456 x Conquista (3) e GC 84058-21-4 x IAC Foscarin 31 (4) foram submetidas à inoculação com a ferrugem e avaliadas quanto ao tipo de lesão (RB – resistente ou TAN – suscetível). O teste de Qui-quadrado indicou a presença de um gene dominante para os cruzamentos 1 e 2, enquanto no 3 e 4 observou-se a presença de um gene recessivo. A análise multivariada agrupou os genótipos mais similares, com base nos caracteres severidade da doença, número de vagens, número de sementes e ciclo, avaliados nos cruzamentos 2 a 4. Diferenças significativas foram encontradas em número de lesões e esporulação para genótipos RB e TAN. Dois bulks de DNA foram obtidos de plantas homozigotas resistentes e suscetíveis no cruzamento 1, para a análise de BSA. Dos 600 iniciadores RAPD testados, três foram discriminativos e localizam-se a 4,5, 6,2 e 10,2 cM do loco de resistência, em fase de repulsão. Um desses marcadores foi convertido a SCAR e se manteve discriminativo, podendo ser indicado para seleção assistida de genótipos resistentes com a mesma fonte. / Assisted selection by molecular markers has contributed to development studies of resistant cultivars. The most evident gains may occur for diseases like the Asian soybean rust, where the high variability of pathogen and the search for new resistance sources has difficult the breeder success. Thus, the aims of this work were to study the rust resistance inheritance in different sources and develop SCAR markers linked to a rust resistance locus for assisted selection. F2 populations from crosses PI 459025 x CD 208 (1), PI 200526 x CD 205 (2), PI 200456 x Conquista (3) and GC 84058-21-4 x IAC Foscarin 31 (4) were submitted to rust inoculation and evaluated by the lesion type reaction (RB – resistant or TAN – susceptible). Chi-square test indicated the presence of a single dominant gene for crosses 1 and 2, whereas the 3 and 4 crosses showed a single recessive gene. Multivariate analysis has grouped the most similar genotypes based on disease severity, number of pods, number of seeds and cycle for 2 to 4 crosses. Significant differences were observed in lesions number and sporulation rate for RB and TAN genotypes. Two DNA bulks were obtained, for BSA analysis, on cross 1, from resistant and susceptible homozygous plants. From the 600 tested RAPD primers, three of them were discriminative and located in repulsion phase at 4.5, 6.2 and 10.2 cM from the resistance locus. One of the RAPD markers was converted to SCAR and confirmed its discriminative nature. So it can be indicated for assisted selection of genotypes with the same resistance source.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-10-11T19:38:10Z No. of bitstreams: 1 DissDPMcg.pdf: 1163116 bytes, checksum: 38b9e1756b3619ed64928eaf8458e248 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-10-17T13:04:52Z (GMT) No. of bitstreams: 1 DissDPMcg.pdf: 1163116 bytes, checksum: 38b9e1756b3619ed64928eaf8458e248 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-10-17T13:05:00Z (GMT) No. of bitstreams: 1 DissDPMcg.pdf: 1163116 bytes, checksum: 38b9e1756b3619ed64928eaf8458e248 (MD5) / Made available in DSpace on 2016-10-17T13:13:15Z (GMT). No. of bitstreams: 1 DissDPMcg.pdf: 1163116 bytes, checksum: 38b9e1756b3619ed64928eaf8458e248 (MD5) Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Partamona (Schwarz, 1939) is a stingless bee genus which has as an interesting trait, the presence of B chromosomes in some species. These chromosomes were identified in six closely related species so far, all included in the cupira group, except P. helleri, which has an uncertain position in Partamona phylogeny, but it is possibly related to this group. We analyzed 894 colonies from 128 locations of thirteen species, using a SCAR marker specific for Partamona B chromosomes. The results enabled an increase in knowledge about species number with supernumerary chromosomes in this genus, including species from the pearsoni clade. The high number of colonies analyzed allowed to set the B chromosomes frequency on carrier species. A significant positive correlation between latitude and B chromosomes frequency was found in P. helleri, with higher frequency in north decreasing towards the south of the species distribution. The B chromosome transmission rate was estimated for three species that showed the highest frequencies of these chromosomes (P. helleri, P. cupira and P. rustica). The result was as expected for a regular meiotic behavior, which queens with one supernumerary chromosome have 50% chance to transfer the B chromosome to the offspring, suggesting an absence drive in these species. The Sequences obtained using SCAR primers had high quality and were different from those previously reported in another studies, showing no undefined sites, indicating greater effectiveness for sequencing using the internal primers designed in our laboratory. The comparison between obtained sequences revealed a high similarity between species, with only two haplotypes and no intraspecific differences, suggesting a single origin for Partamona B chromosomes. The sequence obtained for P. helleri was different from that obtained for the cupira clade species, suggesting that P. helleri did not transmit the B chromosomes to the other species, as previously suggested. The high frequency in some species and the presence in the pearsoni clade suggest a more complex 4 evolutionary history and an older origin than previously thought for Partamona B chromosomes. / Partamona (Schwarz, 1939) é um gênero de abelhas sem ferrão que apresenta como interessante característica a presença de cromossomos B em algumas espécies. Até o momento, esses cromossomos haviam sido identificados em seis espécies intimamente relacionadas, todas incluídas no clado cupira, e P. helleri, de posição incerta na filogenia de Partamona, mas possivelmente relacionada a este clado. A análise de 894 colônias provenientes de 128 localidades de 13 espécies do gênero, utilizando um marcador SCAR (Sequence Characterized Amplified Region) específico para os cromossomos B de Partamona, permitiu ampliar o conhecimento do número de espécies do gênero portadoras destes cromossomos, incluindo espécies do clado pearsoni. A partir dos resultados desta análise foi possível também, definir a frequência dos cromossomos B nas espécies portadoras. Em P. helleri foi encontrada uma correlação positiva significativa entre latitude e frequência de cromossomos B, com maior frequência no norte e diminuição em direção ao sul da distribuição da espécie. A taxa de transmissão de cromossomos B foi estimada para as três espécies em que estes cromossomos foram mais frequentes (P. helleri, P. cupira e P. rustica). O resultado foi consistente com o esperado para um comportamento meiótico regular na transmissão dos cromossomos B da rainha para a prole, sugerindo que nessas espécies não ocorra um desvio meiótico que favoreça a transmissão. As sequências obtidas com os primers SCAR apresentaram alta qualidade e foram diferentes das sequências reportadas na literatura, não apresentando sítios indefinidos, apontando para uma maior acurácia de sequenciamento com o uso dos primers internos desenhados em nosso laboratório. A comparação entre as sequências revelou uma alta similaridade entre espécies, com apenas dois haplótipos e ausência de diferenças intraespecíficas, sugerindo uma origem única para os cromossomos B de Partamona. A sequência obtida para P. helleri foi diferente da sequência obtida para as 2 outras espécies do clado cupira, sugerindo que essa espécie não transmitiu os cromossomos B para as outras espécies do grupo, como previamente sugerido. A alta frequência de cromossomos B em algumas espécies do gênero e a presença de cromossomos B em espécies do clado pearsoni sugere uma história evolutiva mais complexa e uma origem mais antiga do que se presumia anteriormente para os cromossomos B de Partamona.