Thraciidae é uma das famílias de Anomalodesmata menos estudadas, dentre as quatorze que compõem a subclasse. Das cerca de trinta espécies atribuídas à família, apenas Trigonothracia jinxingae teve sua biologia e anatomia examinadas em detalhes; para outros Thraciidae, há pouca ou nenhuma informação morfológica, o que dificulta o entendimento das relações filogenéticas dentre os Anomalodesmata. Thracia meridionalis, única representante da família em águas antárticas, é aqui analisada sob o ponto de vista da anatomia, buscando iniciar o entendimento da biologia da espécie, bem como aprofundar os conhecimentos acerca do gênero Thracia e família Thraciidae, indispensáveis para a elucidação das relações evolutivas dentre os Anomalodesmata. A investigação detalhada da concha, sifões, e das estruturas e órgãos que compõem a cavidade palial e massa visceral foi realizada utilizando-se técnicas de dissecção, histologia e microscopia eletrônica de varredura. A concha é fina, inequivalve, ornamentada por grânulos periostracais calcificados, e dotada de charneira edêntula, ligamento secundário e primário, este último com litodesma presente apenas em indivíduos jovens. O manto tem margens extensivamente fundidas, com curta abertura pediosa, quarta abertura palial reduzida e sifões longos, separados, originando-se exclusivamente das pregas internas; as glândulas hipobranquiais são assimétricas, porém restritas à câmara infra-branquial, o que distingue T. meridionalis dentre os Anomalodesmata. Os ctenídios são extensos, heterorrábdicos e do tipo E de Atkins; uma ampla abertura entre os eixos dos ctenídios e o septo que separa as aberturas proximais dos sifões permite a comunicação entre as câmaras infra e supra-branquiais. A associação entre os palpos labiais e ctenídios pertence à categoria III de Stasek, e os estatocistos são do tipo B3 de Morton, este tipo constituindo novo registro para os Thracioidea. O estômago do tipo IV na classificação de Purchon é extensivamente provido de áreas de triagem, sugerindo que o animal ingere grande quantidade de partículas, o que é corroborado pelo intestino freqüentemente dilatado e repleto de fezes. T. meridionalis é hermafrodita simultâneo, com gônadas, gonodutos e gonóporos distintos. Grandes ovócitos (~200 µm) protegidos por espessa membrana vitelínica, e razão próxima de 0,75 entre os comprimentos das prodissoconchas I e II são indicativos de desenvolvimento larval lecitotrófico. / The functional morphology of the Thraciidae is sparsely understood. Though several of its members had some morphological aspect described, only Trigonothracia jinxingae from Chinese waters is known in details, Thracia meridionalis being the first austral thraciid to be comprehensively reported upon. The latter species is the only representative of the family in Antarctic waters, and a common mud-dweller in the Admiralty Bay, King George Island, where living specimens were collected for the present study. T. meridionalis shares with Trigonothracia jinxingae many features that are typical of most Anomalodesmata: a secondary ligament of fused periostracum; extensively fused mantle margins; ctenidia of type E; ctenidial-labial palp junction of category III; stomach of type IV and simultaneous hermaphroditism. However, T. meridionalis is strikingly different from Trigonothracia in a number of aspects, as the presence of a fourth pallial aperture; statocysts of type B3; heterorhabdic ctenidia; a direct communication between the mantle chambers; deep-burrowing habit, the specimens lying on the left shell valve; siphons often retracted away from the sediment surface, protected within their mucous-lined burrows; stomach with extensive sorting areas; suspension-feeding habit; rectum passing over the kidneys and separate male and female gonadial apertures, thus revealing a greater diversity of form within the Thraciidae than is currently known.

O objetivo do trabalho foi determinar o efeito da temperatura e período de molhamento no processo de infecção de Colletotrichum gloeosporioides e C. acutatum em goiaba e folhas de citros, respectivamente, além de evidenciar o processo de colonização de C. gloeosporioides. Para determinar o processo de infecção em diferentes combinações de temperatura e períodos de molhamento, suspensões de conídios de C. gloeosporioides foram depositadas em placas de poliestireno e incubadas sob temperaturas de 10, 15, 20, 25, 30, 35 e 40 °C, com período de molhamento de 6, 12, 24, 36 e 48 horas. Para C. acutatum, as placas foram incubadas sob temperaturas de 5, 10, 15, 20, 25, 30 e 35 °C, com períodos de molhamento de 6, 12, 24, 36 e 48 horas. In vivo, suspensões de conídios de C. gloeosporioides foram depositadas na superfície de goiabas que foram incubadas sob temperaturas de 10, 15, 20, 25 e 30 °C e períodos de molhamento de 6, 12 e 24 horas. Folhas de citros foram inoculadas com suspensões de dois isolados de C. acutatum e incubadas sob temperatura de 15, 20, 25 e 30 °C e períodos de molhamento de 12, 24 e 48 horas. Para os estudos do processo de colonização, goiabas com 110 dias após a queda das pétalas foram inoculadas e incubadas a 25 °C e períodos de molhamento de 48, 72, 96 e 120 horas. Posteriormente, frutos com 10, 35, 60 e 85 dias também foram inoculados e incubados a 25 °C por 48 horas. Para visualizar estruturas do tecido vegetal e fenóis, secções de frutos com as diferentes idades foram coradas com azul de toluidina e ACN. As temperaturas ótimas in vitro para germinação de C. gloeosporioides, apressórios formados e melanizados foram, respectivamente, 22,7, 20,6 e 23 °C. Para o isolado KLA-MGG-1 de C. acutatum foi 23,9 °C para germinação e 23,5 °C para formação de apressórios, enquanto para o isolado FSH-CLB-2 foi 21,6 °C para ambas as variáveis. Em goiaba, as temperaturas ótimas para germinação de C. gloeosporioides e formação de apressórios foram 22,4 e 23,3 °C, respectivamente. Em folhas de laranjeira, as temperaturas ótimas para os isolados KLA-MGG-1 e FSH-CLB-2 foram, respectivamente, 24,1 e 24 °C para germinação e 21,2 e 23 °C para formação de apressórios. Para folhas de limoeiro, foram 18,1 °C para germinação e 16,2 °C para formação de apressórios do isolado KLA-MGG-1. Para o isolado FSH-CLB-2, as temperaturas ótimas foram 24,4 e 23,7 °C, respectivamente. A estratégia de colonização de C. gloeosporioides foi intracelular hemibiotrófica. Em amostras com 48 h após a inoculação, foi verificado o peg de penetração. Com 72 horas, observou-se a formação da vesícula de infecção. As hifas foram observadas em amostras com 96 h após inoculação. As mesmas estruturas fúngicas alcançaram as células parenquimáticas com 120 horas após inoculação. O peg de penetração foi observado apenas em frutos com 85 e 110 dias. Estruturas do tecido vegetal e fenóis foram alterados com a idade dos frutos. / The objective of this study was to determine the effect of temperature and the wetness periods in the infection process of Colletotrichum gloeosporioides and C. acutatum in guava and citrus leaves, respectively, besides evidencing the colonization process of C. gloeosporioides. To determine the infection process at different temperature and wetness periods combinations, conidial suspensions of C. gloeosporioides were deposited on polystyrene dishes and incubated at 10, 15, 20, 25, 30, 35 and 40 °C with wetness periods of 6, 12, 24, 36 and 48 h. For C. acutatum, the dishes were incubated at 5, 10, 15, 20, 25, 30 and 35 °C, with wetness periods of 6, 12, 24, 36 and 48 h. In vivo conidial suspensions of C. gloeosporioides were placed on the surface of guavas which were incubated at 10, 15, 20, 25 and 30 °C with wetness periods of 6, 12 and 24 h. The citrus leaves were inoculated with suspensions of two isolates of C. acutatum and incubated at 15, 20, 25 and 30 °C with wetness durations of 12, 24 and 48 h. For the analysis on the colonization process, physiological mature guava fruits were inoculated and incubated at 25 °C with wetness periods of 48, 72, 96 and 120 h. Afterward, fruits with 10, 35, 60 and 85 days were also inoculated and incubated at 25 °C for 48 hours. To visualize the structures of vegetal tissues and phenols, sections of fruits at different ages were colored in toluidine blue and ACN. Optical temperature for conidial germination, appressoria formation and appressoria melanization for C. gloeosporioides were, respectively, 22.7, 20.6 and 23.0 °C. For C. acutatum isolate KLA-MGG-1, they were 23.9 °C for germination and 23.5 °C for appressoria formation and for isolate FSH-CLB-2 it was 21.6 °C for both variable. In guava, the temperatures for germination of C. gloeosporioides and appressoria formation were 22.4 and 23.3 °C, respectively. In leaves of orange trees, the optimal temperatures for the isolates KLA-MGG-1 and FSH-CLB-2 were, respectively, 24.1 and 24 °C for germination and 21.2 and 23 °C for appressoria formation. In leaves of lemon trees, they were 18.1 °C for germination and 16.2 °C for appressorial production of isolate KLA-MGG-1. For isolate FSH-CLB-2, the optimal temperatures were 24.4 and 23.7 °C, respectively. The colonization strategy of C. gloeosporioides was intracellular hemibiotrophic. The penetration peg was verified in samples 48 h after inoculation. After 72 h, it was observed formation of infection vesicle. The hyphae were observed in samples 96 h after inoculation. The same fungal structures reached the parenchymal cells 120 hours after inoculation. The penetration peg was observed only in fruits with 85 and 110 days. Structures of guava tissues and phenols were changed with the fruit aging.

Diaphorina citri Kuwayama, 1908 (Hemiptera: Psyllidae) tornou-se um psilídeo de grande importância para a citricultura paulista após a constatação da bactéria Candidatus Liberibacter sp., causadora do Huanglongbing (greening). Sabe-se que esse inseto abriga microrganismos endossimbiontes, os quais desempenham papel fundamental em sua ecologia nutricional, sendo transmitidos verticalmente à progênie. Dessa forma, propomos caracterizar a morfologia do aparelho reprodutor feminino durante o seu desenvolvimento para embasar a identificação do processo de migração dos simbiontes do bacterioma aos tecidos reprodutivos. D. citri possui ovário do tipo telotrófico, com ovaríolos organizados em bouquet e características gerais semelhantes às observadas para outros Sternorrhyncha. Os trofócitos parecem ser desprovidos de delimitação por membrana no ovaríolo desenvolvido. Um único oócito se desenvolve por ciclo no vitelário, o qual mantém-se em contato com a câmara trófica por um prolongamento citoplasmático, denominado cordão trófico. As informações morfo-estruturais do aparelho reprodutor de D. citri obtidas indicam similaridades importantes a de outros membros de Sternorryncha. Nesse contexto, a migração de simbiontes do bacterioma para os oócitos em maturação de D. citri, ocorre de modo semelhante ao descrito para aleirodídeos, caracterizandose pela migração de bacteriócito intacto. Este último, atravessa o epitélio de revestimento do oócito, formado por células foliculares, e invade o oócito, liberando as bactérias nele contidas. Entretanto, os simbiontes associados ao sincício do bacterioma, são liberados na hemocele através de uma pequena abertura formada no epitélio de revestimento dessa estrutura, invadindo o oócito por um mecanismo distinto. Os simbiontes contidos no oócito, formam um agrupamento de aspecto arredondado (= symbiont ball) na região posterior do oócito, próximo ao pedicelo. / Diaphorina citri Kuwayama, 1908 (Hemiptera: Psyllidae) became a serious problem to the citrus industry in São Paulo State once the Huanglongbing disease (greening), which is caused by the bacteria Candidatus Liberibacter sp., was detected. Psyllids are known to harbor endosymbiont microorganisms, which are vertically transmitted to the progeny and play a key role in the nutritional ecology of their hosts. Therefore, we aimed to characterize the morphology of the reproductive system during D. citri development as a tool for further investigation on the symbiont migration from the bacteriome to the reproductive tissues. D. citri has telotrophic ovaries with ovarioles organized in a bouquet, sharing all other characteristics with the remaining Sternorrhyncha. In developed ovarioles, trophocytes seems to lack any membrane delimitation. Only one oocyte develops at a time in the vitellarium, remaining in communication with the trophic chamber by a citoplasmatic brigde, named trophic cord. The morphostructural information reported in here on the D. citri reproductive system shows important similarities with other Sternorryncha. Symbionts associated to the bacteriome of D. citrus migrate to the ovaries and invade the oocytes during ovary maturation, as previously reported for aleyrodids. In this case, symbionts will move within the bacteriocyte as it detaches from the bacteriome and moves through the oocyte follicular epithelium, releasing the contained bacteria into the oocyte. However, symbionts associated to the bacteriome syncitium are relased into the hemocoel through small openings on the bacteriome epithelium, invading the oocyte by a different mechanism. All symbionts that invaded or were discharged into the oocyte aggregate into a balllike symbiont structure at the posterior pole close to the egg pedicel.

Esse estudo avaliou o laser de baixa intensidade (LBI-15J/cm2, 780nm) e a proteína do látex (P1; 0,1%) no esmagamento (15Kgf, axonotmese) do nervo isquiático de ratos Wistar. Grupos: GI-controle; GII-exposto; GIII-lesado; GIV-LBI; GV-P1; GVI-LBI e P1. Após 4 e 8 semanas realizou-se as análises morfológica, morfométrica, imunohistoquímica (VEGF e NGF) e ultraestrutural. Houve melhora com os tratamentos propostos. Após 4 semanas não foi possível eleger o melhor tratamento; após 8 semanas os animais que receberam a P1 associada ou não ao LBI apresentaram mais capilares e fibras nervosas mais organizadas. Após 4 semanas as expressões do NGF e VEGF estavam elevadas nos GIII, GIV e GVI e após 8 semanas elas estavam diminuídas. As características dos grupos lesados eram mais próximos dos controles após 8 semanas, revelando tempo-dependência; ainda nesse período a P1 apresentou melhor recuperação, pois o LBI não alcançou os mesmos resultados, e a associação dos tratamentos não potencializado a recuperação, sugerindo que a melhora observada nesse caso se refere à P1. / This study evaluated the low intensity laser (LBI-15J/cm2, 780nm) and latex protein (P1, 0.1%) in the crush (15 kgf, axonotmesis) of the sciatic nerve in rats. Groups: GIcontrol; GIIexposed; GIII-injured; GIV-LBI; GV-P1; GVI-LBI and P1. After 4 and 8 weeks were performed morphological, morphometric, immunohistochemical (VEGF and NGF) and ultrastructural analysis. There was improvement with the proposed treatments. After 4 weeks has not been possible to choose the best treatment, after 8 weeks, the animals that received the P1 associated or not to LBI had more capillaries and more organized nerve fibers. After 4 weeks the expressions of NGF and VEGF were higher in GIII, GIV and GVI and after 8 weeks they were decreased. The characteristics of the injured groups were closer to control after 8 weeks, revealing time-dependence, even in this period P1 showed better recovery because the LBI did not achieve the same results, and the association of treatments did not enhanced this recovery, suggesting that the improvement observed in this case refers to P1.

Submitted by Cristiane Chim (cristiane.chim@ucpel.edu.br) on 2018-06-04T13:08:21Z No. of bitstreams: 1 JIVAGO DA FONSECA LOPES.pdf: 9499582 bytes, checksum: 9c8c5dfe7ba36c11cfe8d157cbaf26b7 (MD5) / Made available in DSpace on 2018-06-04T13:08:21Z (GMT). No. of bitstreams: 1 JIVAGO DA FONSECA LOPES.pdf: 9499582 bytes, checksum: 9c8c5dfe7ba36c11cfe8d157cbaf26b7 (MD5) Previous issue date: 2017-12-05 / Acrokeratoelastoidosis (AQE) is a type of keratoderma that affects the region palmoplantar, originally described by the dermatologist miner Oswaldo Gonçalves Costa in 1953. It is a rare, autosomal dominant disease, but can occur sporadic. The disease has the first manifestations in childhood and adolescence, but it can occur in adults in a late presentation. The clinical picture is characterized by multiple yellowish, sometimes translucent and keratotic papules, measuring approximately 2-4 mm in diameter, occasionally umbilicated, located at the margin side of the hands and feet, symmetrically, what is its most typical clinical expression. The findings Histopathological findings are: hyperkeratosis, mild acanthosis and elastorrexis. Diagnosis is clinical, corroborated by optical microscopy with specific staining for elastic fibers, which shows a decrease in them. In addition, the electron microscopy (ME) is an important ally to elucidate of AKE. Due to the limited findings in the literature using this technique - scarce studies with analysis of transmission electron microscopy (MET) and none using scanning electron microscopy (MEV) - this study will describe a case of AQE, analyzing its clinical and ultrastructural aspects, two-dimensional with MET and with the MEV, after adequate preparation of the sample using a specific technique to analysis of biological material. It is hoped, therefore, to better describe the disease and contribute for further research in the area, in an attempt to better understand the etiopathogenesis and, to seek more effective forms of treatment than time. / Acroqueratoelastoidose (AQE) é um tipo de queratodermia que acomete região palmoplantar, originalmente descrita pelo dermatologista mineiro Oswaldo Gonçalves Costa em 1953. É uma doença rara, de carater autossômico dominante, porém pode ocorrer de forma esporádica. A doença tem as primeiras manifestações na infância e adolescência, mas pode ocorrer em adultos, em uma apresentação tardia. O quadro clínico é caracterizado por múltiplas pápulas amareladas, por vezes translúcidas e queratóticas, medindo aproximadamente 2-4 mm de diâmetro, ocasionalmente umbilicadas, localizadas na margem lateral das mãos e pés, simetricamente, o que é sua expressão clínica mais típica. Os achados histopatológicos mais comuns são: hiperqueratose, acantose discreta e elastorrexe.O diagnóstico é clinico, corroborado pela microscopia óptica com coloração específica para fibras elásticas, a qual mostra diminuição das mesmas. De forma complementar, a microscopia eletrônica (ME) mostra-se como importante aliada para elucidar aspectos ultraestruturais da da AQE. Devido aos achados limitados na literatura utilizando esta técnica – estudos escassos com análise de microscopia eletrônica de transmissão (MET) e nenhum utilizando microscopia eletrônica de varredura (MEV) - esse estudo irá descrever um caso de AQE, analisando seus aspectos clínicos e ultraestruturais, bidimensionais com a MET e tridimensionais com a MEV, após preparo adequado da amostra com técnica específica para análise de material biológico. Espera-se, com isso, descrever melhor a doença e contribuir para mais pesquisas na área, na tentativa de compreender melhor a etiopatogenia e, consequentemente, buscar formas de tratamento mais eficazes que as existentes até o momento.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-10-03T18:43:06Z No. of bitstreams: 1 2016 - Jorge Ant?nio Casagrande Bretas.pdf: 2891351 bytes, checksum: 638557595a03b65975bc6e16746991f8 (MD5) / Made available in DSpace on 2017-10-03T18:43:06Z (GMT). No. of bitstreams: 1 2016 - Jorge Ant?nio Casagrande Bretas.pdf: 2891351 bytes, checksum: 638557595a03b65975bc6e16746991f8 (MD5) Previous issue date: 2016-08-29 / CAPES / The fat body of insects is involved in very important functions. Thus, the fat body, besides acting as a reserve site and synthesis of proteins, carbohydrates and lipids participates in the production of substances with action on the immune system, detoxification, production of eggs, sperm and pheromone. However, the main function of the fat body is the reserve of lipids. The fat body of insects is usually divided into two regions, the visceral fat body, located near the digestive tract, and the parietal fat body, located near the cuticle. The cell types found in the fat body of insects vary, being found only one type in some and more than ten kinds in others. The main cell types found in the fat body of insects are trophocytes, urocytes and oenocytes. The morphology and biochemistry of fat body Lutzomyia longipalpis, the main vector of visceral leishmaniasis in the Americas, was examined by light microscopy, electron microscopy and high-performance thin layer chromatography. Thus, cuts through the abdomen of adult males and females showed that the fatty body is divided into two main components, in accordance with the spatial distribution in the insect's body: one parietal part which is located just under the cuticle and other visceral which is distributed suspended lobes and often associated with tracheas in hemocele. The fat body of L. longipalpis contains only one cell type, trophocyte, which has a large amount of lipid droplets, protein and glycogen granules in their cytoplasm rosettes. The lipid composition varies according to the physiological and insect species. The neutral lipid stored in fat body found more insects is the triacylglycerol. In addition, small amounts of diacylglycerol, steroids, free fatty acids, carotenoids and monoglycerides are carried by lipoforina (major lipoprotein of the insects). The diacylglycerol is derived from triglycerides stored in fat body and is the main form of fatty acid which are recruited to sites of utilization such as flight muscles, for example. Biochemical analysis of the abdominal tergites L. longipalpis males, by high-performance thin layer chromatography, showed the presence of different classes of neutral lipid (mono-, di- and triacylglycerols, fatty acids, cholesterol and esterified cholesterol) and phospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, lysophosphatidylcholine) in the fat body. Furthermore, the lipid composition of the abdominal tergites varied, with the highest amount of lipids extracted from the fourth tergite, which has pheromone producing gland. Finally, the main neutral lipid extracted from the fat body of L. longipalpis was the triacylglycerol and the main phospholipid was phosphatidylethanolamine. / O corpo gorduroso dos insetos est? envolvido em fun??es de grande import?ncia. Assim, o corpo gorduroso, al?m de atuar como s?tio de reserva e s?ntese de prote?nas, carboidratos e lip?dios participa da produ??o de subst?ncias com a??o no sistema imune, detoxifica??o, produ??o dos ?vulos, espermatozoides e de ferom?nios. Contudo, a principal fun??o do corpo gorduroso ? a reserva de lip?dios. O corpo gorduroso dos insetos normalmente ? dividido em duas regi?es, o corpo gorduroso visceral, localizado pr?ximo do tubo digestivo, e o corpo gorduroso parietal, localizado pr?ximo da cut?cula. Os tipos celulares encontrados no corpo gorduroso dos insetos variam, sendo encontrado apenas um tipo em alguns e mais de dez tipos em outros. Os principais tipos celulares encontrados no corpo gorduroso dos insetos s?o os trof?citos, ur?citos e os oen?citos. A morfologia e a bioqu?mica do corpo gorduroso de Lutzomyia longipalpis, o principal vetor da leishmaniose visceral nas Am?ricas, foi analisado por microscopia de luz, microscopia eletr?nica e cromatografia em camada fina de alta performance. Assim, cortes atrav?s do abd?men de machos e f?meas adultas mostraram que o corpo gorduroso ? dividido em dois componentes principais, de acordo com a distribui??o espacial no corpo do inseto: uma parte parietal que est? localizada logo abaixo da cut?cula, e outra visceral que est? distribu?da em l?bulos suspensos e frequentemente associado a traqueias na hemocele. O corpo gorduroso de L. longipalpis cont?m somente um tipo celular, o trof?cito, o qual possui grande quantidade de got?culas de lip?dios, gr?nulos de prote?na e rosetas de glicog?nio em seu citoplasma. A composi??o lip?dica varia de acordo com a condi??o fisiol?gica e esp?cie do inseto. O lip?dio neutro estocado mais encontrado no corpo gorduroso de insetos ? o triacilglicerol. Al?m disso, pequenas quantidades de diacilglicerol, esteroides, ?cidos graxos livres, carotenoides e monoacilglicerois s?o transportadas por lipoforina (maior lipoprote?na dos insetos). O diacilglicerol ? derivado de triacilglicerois estocados no corpo gorduroso e constitui a principal forma de acido graxo que s?o mobilizadas para os s?tios de utiliza??o tal como os m?sculos de voo, por exemplo. A an?lise bioqu?mica dos tergitos abdominais de machos de L. longipalpis, atrav?s de Cromatografia em camada fina de alta performance, mostrou a presen?a de diferentes classes de lip?dios neutros (mono-, di- e triacilglicerois, ?cidos graxos, colesterol e colesterol esterificado) e fosfolip?dios (fosfatidilcolina, fosfatidiletanolamina, fosfatidilinositol, lisofosfatidilcolina) no corpo gorduroso. Al?m disso, a composi??o lip?dica entre os tergitos abdominais variou, sendo a maior quantidade de lip?dios extra?dos do quarto tergito, o qual possui gl?ndulas produtoras de ferom?nio. Finalmente, o principal lip?dio neutro extra?do do corpo gorduroso de L. longipalpis foi o triacilglicerol e o principal fosfolip?dio foi a fosfatidiletanolamina.

L'objectif de cette étude était de comprendre l'influence des saisons sur la variabilité des propriétés mécaniques des papiers recyclés impliquant l'adjonction de charges en amidon importantes, phénomène ayant des répercussions économiques et environnementales défavorables. Plusieurs voies de recherche ont été explorées comme les conditions de stockage des papiers récupérés après collecte, l'influence des températures des eaux de circuit et l'influence du taux et du type d'éléments fins.<br />Pour atteindre ces objectifs, plusieurs outils permettant une observation à l'échelle de la microfibrille de cellulose (10nm) ont été développés ou adaptés (coloration, immunomarquage, PATAg, marquage fluorescent...) couplés à des techniques de microscopie conventionnelle (optique, transmission, balayage, confocal...) afin de mieux comprendre les modifications de la micromorphologie et de l'ultrastructure des fibres en fonction des différents traitements appliqués et d'établir des corrélations avec les variations des propriétés mécaniques des papiers correspondants. Des techniques d'analyse des fibres de bois et de ses composants ont également été utilisées afin d'étudier la morphologie des fibres (analyseur MorFi) ainsi que d'évaluer de manière plus quantitative leurs différents composants (analyse des sucres, chromatographie en phase gazeuse, 13C RMN). La première partie du projet a permis de mettre en place une démarche méthodologique permettant de corréler les observations au niveau ultrastructural et morphologique des fibres et les propriétés mécaniques des papiers fabriqués à partir de celles-ci. L'application de cette méthode nous a permis dans un second temps de montrer que les papiers récupérés par la collecte devaient être stockés de manière plus protégée en hiver par les centres de tri. De même, nous avons pu mettre en évidence la nécessité de réfrigérer les eaux de circuit dans la machine à papier lorsque la fabrication a lieu en été. Enfin, le dernier chapitre a souligné, par la mise en place d'une nouvelle méthode de marquage (PARA-Gold), le fait que le recyclage entraîne la production d'éléments fins aux propriétés de liaison aux fibres diminuées et des solutions pour réactiver ces derniers ont été proposées aux papetiers.

This thesis presents a comprehensive phylogenetic and taxonomic study of an acoel subgroup, the Childiidae. Members of this taxon are characterized by well-developed male copulatory organs with conical/cylindrical stylets. The phylogenetic analyses, by means of total evidence approach, based on three molecular markers (18S and 28S rRNA genes and Histone H3) and 50 morphological characters reaffirm the non-monophyly of the Childiidae sensu Dörjes, 1968 (Actinoposthiidae and Childia+Paraphanostoma). The total evidence phylogeny strongly support the Childia+Paraphanostoma clade separate from other former members of the Childiidae, which are now placed in Actinoposthiidae. The monophyly of Childia+Paraphanostoma is well corroborated by several morphological characters. A new taxon Childia is defined, in accordance with the PhyloCode, comprising all former Paraphanostoma species and a member of the monotypic genus C. groenlandica. A new diagnosis for the current members of Childia is provided. Several structures, shown to hold promising phylogenetic signals for unraveling acoel relationships, such as musculature pattern, sperm and male copulatory organs, are investigated, using a combination of traditional and modern techniques (ultrastructure, immunocytochemistry and confocal microscopy), with main focus on Childia and its closest relatives. New characters are described and their phylogenetic significance assessed. Morphological characters relating to body-wall musculature, statocyst muscles, male copulatory organ musculature and ultrastructure, and sperm cytoplasmic granules are shown to carry important phylogenetic signals at lower taxonomic levels, while most of the characters related to sperm ultrastructure are useful at higher taxonomic levels within the Acoela. The data obtained undermine the phylogenetic use of the seminal bursa in Childia. In addition to this, it is shown that most of the classical morphological characters used in acoel taxonomy, obtained using traditional histological methods, may be misleading in identifying monophyletic entities within the Acoela. The most corroborated synapomorphies, identified in this thesis, are used in determining the taxonomic placement of a new viviparous acoel, Childia vivipara, into the taxon Childia.

Macroscopical and microscopical observations on extant and fossil plants have been made. Observations on extant plants led to study the effects of volcanic gases on the cuticle ultrastructure of Pinus halepensis and Erica arborea sampled in the volcanic area of Phlegrean Italy. TEM observations on P. halepensis cuticles fumigated or not by volcanic gases revealed: 1) insignificant thickness variations of the cell wall plus cuticle among current- and first-year-old needles of both fumigated and not fumigated trees; 2) a calcium oxalate accumulation in fumigated leaves; 3) moreover, in respect to the cell surface, fibrils are disposed parallel to the surface of the cuticle. In specimens of E. arborea fumigated or not by volcanic gases, 1) the total thickness of cuticles varies significantly; 2) in plants experiencing chronic fumigation the A2 layer increases its thickness. As for fossil plants, the cuticles of Cretaceous Fossil-Lagertätten of Cusano Mutri and Pietraroja have been studied. In the former: 1) numerous taxa belonging to conifers have been identified; 2) the new species Frenelopsis cusanensis has been described; 3) Montsechia vidalii has been found outside of Spain. Taxonomical studies allowed the description of typical Euro-Sinian fossil plants. Sedimentological and taxonomical studies suggest semi-arid or arid conditions in a subtropical or tropical climate. It is worth noting as for Cusano Mutri locality, evidence of wildfire (fusain) suggests a periodic combination of arid periods, high temperatures and lightning strikes.

The main aim of this study was to investigate the effects of water availability and SO2 pollution, imposed separately or simultaneously, on the photosynthetic metabolism of Augea capensis Thunb., a succulent of the Namib Desert in the region of Skorpion Zinc mine, Namibia. The main driver for this investigation was the need to distinguish between the effects of water availability on plants native to a desert environment, where water availability dominates plant response, but where the possibility of anthropogenic SO2 pollution poses a new threat to the unique succulent vegetation. Fifteen measuring sites were selected in the vicinity of the mine to determine how rainfall influenced the physiological status of the vegetation. Chlorophyll a fluorescence measurements, and analysis of recorded OJlP fluorescence transients with the JIP-test, were used for this purpose. A series of laboratory experiments were also conducted on A. capensis to determine the precise physiological response that water deprivation and SO2 pollution had under controlled growth conditions. Potted plants were exposed to water deprivation or SO2 fumigation in the light or dark. Besides chlorophyll a fluorescence, photosynthetic gas exchange and Rubisco activity were also measured. Changes in fast fluorescence rise kinetics observed under field conditions suggest considerable modulation of photosystem II function by rainfall with concomitant involvement of a heat stress component as well. In both the field and laboratory experiments, one of the JIP-test parameters, the so-called performance index (PIABS), was identified as a very sensitive indicator of the physiological status of the test plants. Moreover, under laboratory conditions, a good correlation existed between the water deprivation-induced decline in CO2 assimilation rates and the decline in PIABS values. The JIP-test in general, and the PIABS in particular, shows considerable potential for application in the investigation of water availability influences on desert ecosystems. In the laboratory experiments, water deprivation caused stomatal closure but also a slight elevation in intercellular C02 concentration and inhibition of Rubisco activity, suggesting that mesophyll limitation was the dominant factor contributing to the decrease in C02 assimilation rates. Following re-watering, A. capensis showed remarkable recovery capacity. Fumigation of A. capensis with 1.2 ppm SO2 in the dark or light revealed relatively small effects on C02 assimilation. The inhibitory effects on photosynthesis were also fully reversible, indicating no permanent metabolic/structural damage. The effects on photosynthesis were more pronounced when fumigation occurred in the dark. This phenomenon might be related to diurnal differences in cellular capacity for SO2 detoxification. When long-term moderate water deprivation was combined with simultaneous SO2 fumigation, there was no additional inhibitory effect on photosynthesis. These findings suggest that water deprivation do not increase sensitivity towards SO2 pollution in A. capensis. Fumigation with SO2, singly or in combination with water deprivation also had no major effect on chloroplast ultrastructure. It appears that A. capensis is remarkably resistant to SO2 pollution even in the presence of low water availability, which is a common phenomenon in desert ecosystems. Since A, capensis seems to be highly tolerant to S02, its suitability as an indicator species for the detection of SO2 pollution effects at Skorpion Zinc mine is questionable. Because water availability dominates the physiological/biochemical response in this species, subtle SO2 pollution effects might be difficult to detect against this dominant background. The high water content of A. capensis and similar succulents might act as a substantial sink for SO2 and could convey considerable tolerance against this form of air pollution. / Thesis (M.Sc. (Botany))--North-West University, Potchefstroom Campus, 2006.