In 2012, a new type of lignin, catechyl (C)-lignin was found in the seed coat of vanilla orchid (Vanilla planifolia) and Melocactus cacti, and later in the nutshell of Aleurites moluccana (candlenut). This caffeyl alcohol homopolymer is the exclusive lignin in vanilla seed coat but separated in time and/or location with guaiacyl (G)-lignin in candlenut. Unlike conventional guaiacyl/syringyl (G/S-lignins) with alkyl-aryl ether linkages, intermonomer linkages in C-lignin are connected by benzodioxane linkages which are stiffer than alkyl-aryl ether linkages. C-lignin is unusually stable against acid-catalyzed cleavage. Tissues with C-lignin are expected to exhibit high glass transition temperature (Tg) compared to tissues with G/S/H-lignin. C-lignin also probably shows high crystallinity due to its highly linear-homopolymer structure. The ability of some seed coats/nutshells in angiosperms to synthesize a new type of lignin is another level of lignin evolution. However, the role of C-lignin related to the function of the seed coat is unclear while it exhibits different behaviors to the regular G/S/H-lignin. These points motivated us to conduct cell-wall structure/property studies in the context of plant evolution, using microscopy, X-ray diffraction (XRD) and dynamic mechanical analysis (DMA). Light and electron microscopes were used to identify cell's size and type of intact and macerated vanilla seed coat and candlenut shell. Vanilla seeds are tiny, sized approximately 300μm and the surface is covered with dark-colored seed coat. Candlenut is slightly smaller than walnut, with uneven, hard, dark brown shell covering the nut. Microscopy observations indicated that both seed coat and nutshell are dominated by highly lignified cells, known as sclereids. The types of sclereids in vanilla seed coat and candlenut shell are different; vanilla seed coat has ostoesclereid-type cells, while candlenut shell has macrosclereid-type cells. XRD was used to study tissue with C-lignin crystallinity by comparing diffractograms of vanilla seed coat and candlenut shell to Southern Yellow Pine wood diffractograms. The Southern Yellow Pine wood diffractogram corresponds to a typical native cellulose in higher plants, that is cellulose I allomorph. Diffractogram XRD analysis on vanilla seed coat and candlenut shell shows similarities to Southern Yellow Pine native cellulose, suggesting that cellulose is the contributor for crystallinity in seed coat and nutshell, and this also indicated that tissues with C-lignin is not crystalline. Crystallinities of vanilla seed coat and candlenut shell determined using peak deconvolution methods were about half of Southern Yellow Pine crystallinity. DMA was used to measure Tg in vanilla seed coat and candlenut shell. Measurements were conducted in solvent-submersion mode using organic plasticizers to reduce the Tg to non-damaging temperatures. DMA measurement of vanilla seed coat and candlenut shell is challenging due to specimen size and shape. Specimen preparation for DMA measurement included seed coat purification for vanilla and cutting/milling for candlenut shell followed by specimen saturation in plasticizers. Compressive-torsion DMA was used to allow tiny specimens gripping. Vanilla seed coats exhibited higher glass transition temperature compared to wood, while candlenut shells exhibited various Tgs depending on specimen type/size. / Doctor of Philosophy / Lignin is a complex organic material that constructs higher plant cell walls. Lignin provides stiffness and strength and is the landmark of plant evolution to terrestrial life. Typically, lignin in hardwood/softwood has guaicayl and/syringyl (G/S) units derived from coniferyl/sinapyl alcohols. ln 2012, a new type of lignin, catechyl (C)-lignin, was found in the seed coat of vanilla orchid (Vanilla planifolia) and Melocactus cacti, and later in the nutshell of Aleurites moluccana (candlenut). C-lignin is a caffeyl alcohol homopolymer and is exclusive in vanilla seed coat but coexists with guaiacyl (G)-lignin in candlenut shells. This new type of lignin exhibits different behavior than G/S-lignin. C-lignin is unusually stable against acid-catalyzed hydrolysis. Intermonomer linkage in C-lignin is stiffer than G/S lignin(s); it is likely to have higher glass transition temperature (Tg) than normal lignin. Due to its linearity, tissue with C-lignin is also expected to be highly crystalline. C-lignin's roles are not well known and therefore, these are merit for structure/property studies in the context of plant evolution as bio-inspired new materials. Microscopy, X-ray diffraction (XRD), and dynamic mechanical analysis (DMA) were used to study vanilla seed coat and candlenut shell morphology, crystallinity, and glass transition temperatures (Tg), respectively. It was observed that the two tissues have different types of sclereids, but this is not associated with why vanilla seed coats exhibit only C-lignin while candlenut shells have both C /G-lignins. XRD scans revealed that C-lignin is not crystalline due to similarity of their diffractograms to those of wood. DMA measurements revealed that vanilla seed coat tissues exhibit higher Tg than tissue with G/S lignin as expected, while the Tg candlenut shells varied among specimen type and particle sizes.

The continuing quest for higher performance levels of modern gas turbine engines has been accompanied by the demand for higher engine operating temperatures. The use of Thermal Barrier Coatings (TBCs) enabled gas turbines to operate at higher temperatures by protecting the blade material (nickel superalloy) while operating in extreme environments. The TBC system typically consists of a bond coat for protection of the nickel–based superalloy against oxidation followed by a top coat consisting of a thermally insulating zirconia-yttria. In addition to the complex gradation in phases, the coatings are subjected to continuous oxidation with service exposure, mechanical loading on rotating parts, fatigue, thermal mis-match and temperature gradients. Hence, the study of failure mechanisms of TBCs become important in deciding operational reliability and service life of the coating. As there are many systems in which the operating temperatures are not high enough to warrant the use of the top coat (ceramic layer), the study of failure mechanisms in superalloys coated with only the bond coat continue to be of great interest. The present work concentrates on the fracture behavior of NiAl bond coats on nickel superalloy and seeks to evaluate the fracture toughness of the coating through the use of micro-machined samples. A review of the relevant literature indicated that while a considerable body of work exists on bulk tests of failure (spalling, splitting, etc.), not much has been reported in the open literature on the evaluation of basic quantities such as the toughness of the coating itself. The present thesis seeks to establish a protocol for the evaluation of toughness and crack propagation mechanisms in coatings through a combination of micro-sample testing that allows fracture to be correlated with location in the film and the use of an analytical model to quantitatively evaluate stress intensity factors in a bi-material system. A system of NiAl coating produced by pack aluminizing is studied for the fracture properties of the coating. Specimen geometries are optimized to enable micro-cracks to be machined and propagated in a low load testing system, such as a depth sensing indenter, so that crack lengths (and position relative to the interface) can be correlated with load. To enable linear elastic theory to be used, dimensions are determined that allow fracture before general yielding. A three point bending test using miniaturized micro-beam specimens of ~ 4 X 0.3 X 0.3 mm is found to be suitable for the above purpose. The technique is a challenging one that requires focused ion beam machining (FIB) along with careful handling and alignment of small samples. The coatings are characterized for their microstructure by electron microscopy to identify compositional variation across the thickness and to determine the thickness of the coating and inter diffusion zone (IDZ). The crack advancement is monitored with increments of loading and the stress intensity factor is evaluated using a program written in “MAPLE” for an edge crack subjected to bending in a bilayered material. Surprisingly, fracture in this system is found to be stable owing to a gradual increase in toughness from the coating surface to the interface. Such an increase from less than 2 to more than 9 MPa m0.5 may be due to the increasing Ni/Al ratio across the thickness of the bond coat. Crack branching is observed as the crack approaches the IDZ and the reasons for such behaviour are not fully understood. This work establishes the viability of this technique to determine fracture properties in highly graded coated systems and may be readily extended to more complex coating architectures and other forms of loading such as cyclic, mixed mode, etc.

The master thesis is dealing with characterization of the structure and properties of the YSZ thermal barrier coating deposited by water hybrid plasma spray technology on the CoNiCrAlY bond coats modified by using electron beam and vacuum annealing. Deposition of the bond coats was performed via high velocity oxy-fuel technology and cold spray. In case of experimental evaluation, the microstructure and chemical composition of the ceramic top coat deposited with powder and suspension feedstock was analyzed. The same analysis procedure was used also for bond coats after electron beam remelting by using two sets of parameters. Furthermore, the changes in microstructure and chemical composition of the remelted and annealed bond coats was evaluated. Eventually, the micromechanical properties of the top coats and the bond coats were measured. The ceramic top coats deposited with powder feedstock exhibited the structure composed by splats, while the top coats deposited in form of suspension showed fine structure with columnar grains. The dendritic structure was observed on remelted bond coats. The annealing process had an influence on the structure in form of coarsened phases and the chemical composition was changed due to diffusion of the elements.

The results of the measurements presented in this manuscript show that none of the coatings has a significant impact on the performance degradation over the course of cell reversal cycling. However, for the EOL polarization curves, the voltage is significantly decreased for the carbon coatings compared to the Au coating. Further experiments should be performed here to determine if these are measurement inaccuracies or if the trend is confirmed. The BIP coatings Cr/a-C also perform worse in the resistance measurements of the HFR and ICR, with the pre-coat variant having the highest values after the tests. The surface changes, which can be seen in the area of the BIP deflections, probably also have an influence here. These appear to be more distinct for the BIP coating Cr/a-C pre-coat. Here, it should be analyzed in more detail how the surface changes and whether metal ions can emerge. The use of the BIP coatings Cr/a-C post- and pre-coat offers a lot of potential, both economically and technically, but cannot be recommended without reservation, as further investigations are still required. / Die Ergebnisse der in diesem Manuskript vorgestellten Messungen zeigen, dass keine der Beschichtungen einen signifikanten Einfluss auf die Leistungsverschlechterung im Verlauf der Cell Reversal Zyklen hat. Bei den EOL Polarisationskurven ist die Spannung bei den Kohlenstoffbeschichtungen jedoch deutlich niedriger als bei der Au-Beschichtung. Hier sollten weitere Experimente durchgeführt werden, um festzustellen, ob es sich um Messungenauigkeiten handelt oder ob der Trend bestätigt wird. Die BIP-Beschichtungen Cr/a-C schneiden auch bei den Widerstandsmessungen des HFR und ICR schlechter ab, wobei die pre-coat nach den Tests die höchsten Werte aufweist. Wahrscheinlich haben auch hier die Oberflächenveränderungen, die im Bereich der BIP Umlenkungen zu sehen sind, einen Einfluss. Diese scheinen bei der BIP Beschichtung Cr/a-C pre-coat deutlicher ausgeprägt zu sein. Hier sollte noch genauer analysiert werden, wie sich die Oberfläche verändert und ob Metallionen austreten können. Der Einsatz der BIP Beschichtungen Cr/a-C post- und pre-coat bietet sowohl wirtschaftlich als auch technisch viel Potenzial, kann aber nicht uneingeschränkt empfohlen werden, da noch weitere Untersuchungen erforderlich sind.

No description available.

Clostridium difficile is a Gram positive pathogen of significant importance in the UK, Europe and the USA. No vaccine has been developed and current treatments are focused on hospital management and the use of antibiotics. The disease is spread in hospitals in the spore form and the role of spores in C. difficile infecton is poorly understood. In this project spores of C. difficile have been characterised. The proteins from the outermost layers of the spore were identified and the genes cloned. Three of these surface proteins have unique enzymatic properties that maybe important for symptoms of disease. The ability of C. difficile spores to adhere to intestinal cells was found to be far greater than with live cells and through this we have identified that the spore may play an important role in colonisation. The regulation of spore coat gene expression during sporulation was also examined and temporal phases of genes expression identified. A major part of this project was to develop a mucosal vaccine to C. difficile. The approach used was to clone the C-terminus of toxin A onto the surface of Bacillus subtilis spores and use these recombinant spores to immunise mice and hamsters. We found that oral delivery of these spores conferred 75% protection to C. difficile infection in a hamster model of infection. Further, parenteral immunisation of the same antigens (toxin A and B) failed to generate mucosal responses and this showed that mucosal immunisation is critical for good protection. Finally, we found that antibodies to the C-terminus of toxin A were cross reactive to the C-terminus of toxin B. This showed that mucosal delivery of just the C-terminus of toxin A is sufficient to confer protection in an animal model of infection. The outcome of this work is that we have shown the parameters for successful immunisation and vaccination against C. difficile.

Le 25 octobre 1415, avec la disparition des derniers représentants du groupe par filiation directe, s’éteignait au combat le lignage de Craon dont la renommée et la fortune avaient été acquises, entre autres, sur les champs de bataille. Notre travail s’inscrit dans une perspective chronologique : la genèse du lignage des Craon au XIe siècle puis son fonctionnement jusqu’à sa disparition à Azincourt. À partir de l’étude sur la famille de Craon, nous proposons une réflexion sur le concept lignager. Pouvons-nous d’ailleurs parler sans nuance de lignage ? Le lignage du XIIe siècle ne ressemble pas à celui des siècles suivants : il s’agit d’une structure de parenté complexe recouvrant des réalités multiples. Si la nécessité d’une terminologie commune nous apparaît évidente, il convient cependant de rester prudent sur l’usage de « lignage ». Son emploi abusif en a appauvri le sens à tel point que nous avons l’impression que ce terme pose aujourd’hui un problème sémantique : peut-on opposer systématiquement deux structures de parenté – « carolingienne » et lignagère ? Le corpus documentaire des Craon nous met dans une position inconfortable puisqu’il nous oriente sur une structure de parenté particulière : le lignage. L’enjeu de ce travail consiste donc à formuler un questionnement sur le lignage à travers une documentation partielle et orientée qui en postule l'existence. L’emploi de ce terme ne nous offre qu’une vision simpliste de la parenté et ne prend pas assez en compte d’autres formes qui coexistent au même moment : sur une structure patrilinéaire de transmission des biens et des pouvoirs se plaque un système de filiation indifférenciée. Le monument funéraire des Craon, dans la chapelle des Cordeliers à Angers, réalisé par Maurice V de Craon à la fin du XIIIe siècle, est un document essentiel : il illustre une conception de la famille telle qu’elle se manifeste dans les actes de la pratique accordant une place essentielle aux alliances, au moins autant qu’à la filiation et dans laquelle la notion de lignage est difficile à cerner. Or, une telle représentation peut coexister avec d’autres, répondant à d’autres besoins et véhiculant d’autres messages : le lignage n’oblitère pas d’autres formes de parenté. Notre travail nous invite à remettre en cause les schémas modèles et à voir la parenté comme une intrication de systèmes diversement opératoires, par effet de sources ou selon le contexte, soumis au poids des normes canoniques omniprésentes à l’époque. / On October 25th 1415, the last direct descendents of the Craon lineage, founded in the 11th Century by Robert of Burgundy, died on the battlefield. A great part of their renown and fortune had been acquired through their feats of arms. Hence the chronologically-based approach of our work: from the genesis of this lineage, we probe into the way they lived and evolved, until they vanished in Agincourt. The study of the Craon family leads us to consider the concept of lineage. The term itself seems impossible to handle without bringing out various shades of its meaning. Lineage is a complex, multifaceted parental structure, and our work intends to mirror these intricacies and evolving features. Indeed, the lineage in the 12th Century is very different from that of the previous centuries. Although it seems essential to use a term common to all History researchers, we believe the word “lineage” needs to be qualified: a great part of its meaning has been sucked out from the lexeme itself by an abusive usage, so much so that we are now faced with a semantic issue: can we consistently oppose these two parental structures – caroligian pattern and lineage? The corpus of documents relevant to the Craons seems to be pointing to lineage, which places us in a puzzling situation. The aim of our work is thus to raise questions about lineage, relying on incomplete documentation. But we should bear in mind that the term lineage allows only an oversimplified approach to kinship, which does not take into account other forms of patterns coexisting at the same moment: indeed, a system of undifferenciated filiation is superimposing itself over a patrilinear structure of the transmission of wealth. The Craons’ funerary monument, in the chapel of the Cordeliers in Angers, and built by Maurice V of Craon at the end of the 13th Century, is an essential document: it reveals a conception of the family which takes into consideration filiation as much as alliances, therefore blurring the outlines of the notion of lineage. However, this representation can stand side by side with others, fulfilling other needs and conveying other messages: lineage does not annihilate other forms of kinship. Henceforth, our work leads us to put into question the traditional patterns and to view kinship as an intricacy of systems with various levels of functioning, and following the constraining and yet unabiding canonic norms of the time.

A aplicação de pintura de ligação entre camadas asfálticas é prática comum em obras de pavimentos novos ou restaurações, sendo importante para garantir a aderência entre as camadas. Esse tratamento da interface geralmente é feito com emulsão asfáltica, que faz com que a estrutura do pavimento trabalhe como um sistema monolítico, evitando problemas de trincamento precoce por fadiga, ou escorregamentos. Esse trabalho tem como objetivo estudar a variabilidade de comportamento dos revestimentos asfálticos quanto à aderência na interface, tendo em vista a taxa aplicada de pintura de ligação, o tipo de emulsão (convencional ou modificada por polímero), a superfície de contato entre as camadas e a presença, ou não, de um sistema anti-reflexão de trincas (geotêxtil e grelha de fibra de vidro). A aderência foi medida por meio do ensaio de cisalhamento direto Leutner, em amostras produzidas em laboratório e extraídas de pista. Foram produzidas placas com dupla camada de revestimento asfáltico, sendo a camada superior um CBUQ (Concreto Betuminoso Usinado a Quente) e a inferior, ora SAMI (Stress Absorbing Membrane Interlayer), ora CBUQ, variando a taxa de aplicação de pintura de ligação na interface (0,0; 0,25; 0,5 e 0,75 L/m2) e o tipo de emulsão aplicada (RR-1C, RR- 1C-E e RR-2C-E), além de testar duas diferentes dimensões para as amostras cilíndricas ensaiadas (100 e 150 mm de diâmetro). Os ensaios de cisalhamento direto foram feitos com carregamento monotônico, à taxa de deslocamento de 50mm/min e à temperatura de 20ºC. Realizou-se o mesmo ensaio também com velocidade de 1 mm/min para avaliar a influência desse parâmetro nos resultados de aderência para as três emulsões testadas. As amostras de pista, com 100 mm de diâmetro, foram retiradas de um trecho experimental na Rodovia Ayrton Senna (SP- 070), do km 38,000 ao 39,500. Os resultados do teste de aderência em laboratório demonstraram influência do tipo de emulsão, da presença de geotêxtil/grelha na interface, do diâmetro da amostra, da textura superficial entre camadas e da velocidade de ensaio nos valores de tensão cisalhante máxima e na taxa ótima de aplicação de emulsão. Os valores de taxa ótima de pintura de ligação foram maiores quando na presença de geotêxtil na interface e para superfícies de contato com maior macrotextura. Quanto à aderência, as amostras com grelha não apresentaram diferença significativa comparadas ao uso de interface somente com pintura de ligação, enquanto as amostras com geotêxtil na interface resultaram em valores bem 8 inferiores de tensão cisalhante máxima. Para ensaios com diferentes tipos de pintura de ligação, as amostras com emulsão modificada nem sempre apresentaram melhores resultados em relação às amostras com emulsão convencional. / Asphalt tack coat is commonly applied at the interface between asphalt layers during new pavement construction or overlay to ensure proper bond between the layers. This treatment at the interface, usually done with asphalt emulsion, allows the pavement structures to function as a monolithic system, avoiding problems like premature fatigue cracking, or slippage. This study aims to evaluate: (i) the influence of the tack coat type (neat or polymer modified asphalt emulsion), (ii) the application rate, (iii) the surface type, and (iv) the presence, or not, of an anti-reflective cracking interlayer (geotextile and fiber glass grid), in the adhesion properties between asphalt concrete layers. The adhesion between layers was tested through the Leutner shear test in laboratory and field samples. A double-layer system was produced with HMA as the top layer and SAMI (Stress Absorbing Membrane Interlayer), or HMA, as the bottom layer, varying the tack coat type (RR-1C, RR-1C-E e RR-2C-E), the application rate at the interface (0,0; 0,25; 0,50 and 0,75 L/m²) and the samples diameter (100 and 150 mm diameter). It was used the standard shear displacement rate of 50 mm/min, and the test temperature was set at 20°C. The same procedure was run with a displacement rate of 1 mm/min to evaluate its influence on the adhesion of three asphalt emulsions used as the tack coat. An experimental test section was constructed on Rodovia Ayrton Senna (SP-070), from km 38,000 to 39,500, and core samples (100 mm diameter) were extracted. The results of maximum shear stress demonstrate the influence of the tack coat type, the surface type, the sample diameter, the test displacement rate and the presence of a geotextile/grid on the adhesion at the interface between the asphalt layers,. Samples with grid at the interface presented similar results when compared with the samples with only tack coat at the interface. Samples with geotextile, however, presented significant lower values of maximum shear stress. The Leutner results showed that not always the modified asphalt emulsions present higher shear strength when compared to the neat asphalt emulsions.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-10-07T21:30:40Z No. of bitstreams: 1 INCID?NCIA, VARIABILIDADE MOLECULAR DE V?RUS E CULTIVO IN VITRO DE MERISTEMAS DE _20160429093320061.pdf: 1513731 bytes, checksum: b1a69730145b3f5bec766a5adb8b491c (MD5) / Made available in DSpace on 2016-10-07T21:30:40Z (GMT). No. of bitstreams: 1 INCID?NCIA, VARIABILIDADE MOLECULAR DE V?RUS E CULTIVO IN VITRO DE MERISTEMAS DE _20160429093320061.pdf: 1513731 bytes, checksum: b1a69730145b3f5bec766a5adb8b491c (MD5) Previous issue date: 2016-03-21 / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / The vine is grown in many countries, the berries being the main product with many uses, such as fresh grapes, juices and wines. The wine industry is an important economic activity in Brazil, highlighting the pole Petrolina, PE / Juazeiro, BA in sub middle of San Francisco Valley (SSFV), as the main producing region of fine table grapes in the country. The multiplication of vine cuttings is done mainly by vegetative propagation, facilitating the spread of pathogens, one of the main sources of the spread of the virus. This study aimed to evaluate the incidence of Grapevine virus A virus (GVA), Grapevine leafroll-associated virus 1 (GLRaV-1), Grapevine leafroll-associated virus 3 (GLRV-3), Grapevine fanleaf virus (GFLV) and Grapevine fleck virus (GFkV) by detecting by Double Antibody Sandwich ELISA (DAS-ELISA) in grapevines of SSFV in six municipalities located in the states of Bahia and Pernambuco, as well as analyze the regenerative capacity and in vitro development of 13 different tropical clones of vine obtained by cultivation of apical meristems and axillary buds, and finally, to analyze the variability of the fragments of the protein coat (PC) gene of the virus winding the sheet cultivars of tropical vines of the San Francisco Valley. Of the 490 samples evaluated, 320 are cultivars for table with and without seeds, 94 for wine and 76 rootstocks. Infections caused by viruses were detected in 79.4% of samples. The GLRaV-3 was the most widespread viruses, followed by GVA GFkV, GLRaV-1 and GFLV, respectively. Mixed infection was detected in 153 samples. Cultivars wine, fine table grapes and rootstocks showed total percentage of 93.2% infection, 52.6% and 31.9%, respectively. For the regenerative capacity and development in vitro, we analyzed the percentage of regeneration time and the numbers of buds, roots and leaves produced as well as the length of the internodal segments 30, 60 and 90 days of cultivation in culture medium 'MS' and 'Galzy', respectively. Of the 13 cultivars tested, four were regenerated with a percentage ranging between 7% and 47%. The occurrence of significant differences among cultivars showed different responses over time. 'Cabernet Sauvignon' presented the best regeneration response starting from apical meristem and axillary buds. 'IAC-572' stood out with the highest average height and bud and leaf numbers 30, 60 and 90. To determine the variability of the CP gene, samples of 28 BAG vines cultivars of the Embrapa Semiarid with and without of disease symptoms were analyzed by reverse transcriptase and polymerase chain reaction (RT-PCR). Of all the samples GLRaV -1, -2 and -3, zero, 10 and 19 presented infection, respectively, and eight had mixed infection. There was a high and low identity between isolates obtained from Brazilian and foreign isolated for both viruses, finding genetic divergence of the CP gene in some isolates. 13 isolates showed no significant homology with other isolates in the present study and available on GENBANK, to GLRaV-3. / A videira ? cultivada em v?rios pa?ses, sendo as bagas o produto principal com diversos usos, como uvas frescas, sucos e vinhos. A vitivinicultura ? uma atividade econ?mica importante no Brasil, destacando-se o polo Petrolina, PE/Juazeiro, BA no Subm?dio do Vale do S?o Francisco (SVSF), como a principal regi?o produtora de uvas finas de mesa do pa?s. A multiplica??o de mudas de videira ? feita principalmente por propaga??o vegetativa, facilitando a difus?o de pat?genos, sendo uma das principais fontes de dissemina??o dos v?rus. No presente estudo, objetivou-se avaliar a incid?ncia dos v?rus Grapevine virus A (GVA), Grapevine leafroll-associated virus 1 (GLRaV-1), Grapevine leafroll-associated virus 3 (GLRV-3), Grapevine fanleaf virus (GFLV), e Grapevine fleck virus (GFkV), atrav?s da detec??o por Double Antibody Sandwich ELISA (DAS-ELISA), em parreirais do SVSF, em seis munic?pios, localizados nos estados da Bahia e Pernambuco, como tamb?m analisar a capacidade regenerativa e desenvolvimento in vitro de 13 diferentes clones tropicais de videira obtidos pelo cultivo de meristemas apicais e de gemas axilares, e por fim, analisar a variabilidade dos fragmentos do gene da capa proteica (CP) do v?rus do enrolamento da folha de cultivares de videiras tropicais do Vale do S?o Francisco. Das 490 amostras avaliadas, 320 s?o cultivares para mesa com e sem sementes, 94 para vinho e 76 de porta-enxertos. Infec??es causadas por v?rus foram detectadas em 79,4% das amostras. O GLRaV-3 foi o v?rus mais disseminado, seguido por GVA, GFkV, GLRaV-1 e GFLV, respectivamente . Infec??o mista foi detectada em 153 amostras. Cultivares para vinho, uvas finas de mesa e porta-enxertos apresentaram porcentagem total de infec??o de 93,2%, 52,6% e 31,9%, respectivamente. Para a capacidade regenerativa e desenvolvimento in vitro, foram analisadas a porcentagem de regenera??o, altura, e os n?meros de gemas, ra?zes e folhas produzidas, bem como o comprimento dos segmentos internodais, aos 30, 60 e 90 dias de cultivo em meio de cultura ?MS? e ?Galzy?, respectivamente. Das 13 cultivares testadas, quatro foram regeneradas com porcentagem variando entre 7% e 47%. A ocorr?ncia de diferen?as significativas entre as cultivares revelaram respostas distintas ao longo do tempo. ?Cabernet Sauvignon? apresentou a melhor resposta de regenera??o de plantas partindo de meristema apical e de gemas axilares. ?IAC-572? destacou-se com as maiores m?dias de altura e n?meros de gemas e de folhas aos 30, 60 e 90. Para determinar a variabilidade do gene da CP, amostras de 28 cultivares de videiras do BAG da Embrapa Semi?rido com presen?a e aus?ncia dos sintomas da doen?a foram analisadas por Transcriptase Reversa e Rea??o em Cadeia da Polimerase (RT-PCR). De todas as amostras para GLRaV -1, -2 e -3, zero, 10 e 19 apresentaram infec??o, respectivamente, sendo que oito apresentaram infec??o mista. Observou-se alta e baixa identidade entre os isolados obtidos com isolados brasileiros e estrangeiros para ambos os v?rus, encontrando-se diverg?ncia gen?tica do gene da CP em alguns isolados. 13 isolados n?o apresentaram homologia significativa com outros isolados do presente estudo e dispon?veis no GENBANK, para GLRaV-3.

A aplicação de pintura de ligação entre camadas asfálticas é prática comum em obras de pavimentos novos ou restaurações, sendo importante para garantir a aderência entre as camadas. Esse tratamento da interface geralmente é feito com emulsão asfáltica, que faz com que a estrutura do pavimento trabalhe como um sistema monolítico, evitando problemas de trincamento precoce por fadiga, ou escorregamentos. Esse trabalho tem como objetivo estudar a variabilidade de comportamento dos revestimentos asfálticos quanto à aderência na interface, tendo em vista a taxa aplicada de pintura de ligação, o tipo de emulsão (convencional ou modificada por polímero), a superfície de contato entre as camadas e a presença, ou não, de um sistema anti-reflexão de trincas (geotêxtil e grelha de fibra de vidro). A aderência foi medida por meio do ensaio de cisalhamento direto Leutner, em amostras produzidas em laboratório e extraídas de pista. Foram produzidas placas com dupla camada de revestimento asfáltico, sendo a camada superior um CBUQ (Concreto Betuminoso Usinado a Quente) e a inferior, ora SAMI (Stress Absorbing Membrane Interlayer), ora CBUQ, variando a taxa de aplicação de pintura de ligação na interface (0,0; 0,25; 0,5 e 0,75 L/m2) e o tipo de emulsão aplicada (RR-1C, RR- 1C-E e RR-2C-E), além de testar duas diferentes dimensões para as amostras cilíndricas ensaiadas (100 e 150 mm de diâmetro). Os ensaios de cisalhamento direto foram feitos com carregamento monotônico, à taxa de deslocamento de 50mm/min e à temperatura de 20ºC. Realizou-se o mesmo ensaio também com velocidade de 1 mm/min para avaliar a influência desse parâmetro nos resultados de aderência para as três emulsões testadas. As amostras de pista, com 100 mm de diâmetro, foram retiradas de um trecho experimental na Rodovia Ayrton Senna (SP- 070), do km 38,000 ao 39,500. Os resultados do teste de aderência em laboratório demonstraram influência do tipo de emulsão, da presença de geotêxtil/grelha na interface, do diâmetro da amostra, da textura superficial entre camadas e da velocidade de ensaio nos valores de tensão cisalhante máxima e na taxa ótima de aplicação de emulsão. Os valores de taxa ótima de pintura de ligação foram maiores quando na presença de geotêxtil na interface e para superfícies de contato com maior macrotextura. Quanto à aderência, as amostras com grelha não apresentaram diferença significativa comparadas ao uso de interface somente com pintura de ligação, enquanto as amostras com geotêxtil na interface resultaram em valores bem 8 inferiores de tensão cisalhante máxima. Para ensaios com diferentes tipos de pintura de ligação, as amostras com emulsão modificada nem sempre apresentaram melhores resultados em relação às amostras com emulsão convencional. / Asphalt tack coat is commonly applied at the interface between asphalt layers during new pavement construction or overlay to ensure proper bond between the layers. This treatment at the interface, usually done with asphalt emulsion, allows the pavement structures to function as a monolithic system, avoiding problems like premature fatigue cracking, or slippage. This study aims to evaluate: (i) the influence of the tack coat type (neat or polymer modified asphalt emulsion), (ii) the application rate, (iii) the surface type, and (iv) the presence, or not, of an anti-reflective cracking interlayer (geotextile and fiber glass grid), in the adhesion properties between asphalt concrete layers. The adhesion between layers was tested through the Leutner shear test in laboratory and field samples. A double-layer system was produced with HMA as the top layer and SAMI (Stress Absorbing Membrane Interlayer), or HMA, as the bottom layer, varying the tack coat type (RR-1C, RR-1C-E e RR-2C-E), the application rate at the interface (0,0; 0,25; 0,50 and 0,75 L/m²) and the samples diameter (100 and 150 mm diameter). It was used the standard shear displacement rate of 50 mm/min, and the test temperature was set at 20°C. The same procedure was run with a displacement rate of 1 mm/min to evaluate its influence on the adhesion of three asphalt emulsions used as the tack coat. An experimental test section was constructed on Rodovia Ayrton Senna (SP-070), from km 38,000 to 39,500, and core samples (100 mm diameter) were extracted. The results of maximum shear stress demonstrate the influence of the tack coat type, the surface type, the sample diameter, the test displacement rate and the presence of a geotextile/grid on the adhesion at the interface between the asphalt layers,. Samples with grid at the interface presented similar results when compared with the samples with only tack coat at the interface. Samples with geotextile, however, presented significant lower values of maximum shear stress. The Leutner results showed that not always the modified asphalt emulsions present higher shear strength when compared to the neat asphalt emulsions.