17,878 research outputs found

    Growth and characterization of materials for tunable lasers in the near infrared spectral region

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    During this reporting period, work proceeded in two directions. The first was the development of crystal growth procedures for rare earth doped LiYF4 crystals. The procedures for growth and pre-growth treatment of starting materials for undoped LiYF4 crystals were established and good optical quality materials were grown. A significant amount of time was spent trying to establish the optimum growth parameters for Yb(3+)-doped crystals. Unfortunately, it has proven difficult to obtain large size boules of high optical quality crystals of LiYF4 with doping concentrations of Yb(3+) of several percent. Because of these problems, this research is to be changed to attempt doping with other trivalent rare earth ions such as Ho, Er, and Tm. The second research area was investigating the potential of LiNbO3:Mg,Cr and LiNbO3:Mg,Cr,Yb as possible laser materials. The results are summarized

    Growth and characterization of tunable solid state lasers in the near infrared spectral region

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    This research resulted in the publication of two major papers. The major results include the development of improved crystal growth techniques for rare earth-doped LiYF4 crystals and the determination of laser-pumped laser characteristics of Tm:Ho:Y3Al5O12 crystals

    The Early Evolution of Rhynchosaurs

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    The rhynchosaurian archosauromorphs are an important and diverse group of fossil tetrapods that first appeared during the Early Triassic and probably became extinct during the early Late Triassic (early Norian). Here, the early evolution of rhynchosaurs during the Early and early Middle Triassic (Induan-Anisian: 252.2-242 Mya) is reviewed based on new anatomical observations and their implications for the taxonomy, phylogenetic relationships and macroevolutionary history of the group. A quantitative phylogenetic analysis recovered a paraphyletic genus Rhynchosaurus, with “Rhynchosaurus” brodiei more closely related to hyperodapedontines than to Rhynchosaurus articeps. Therefore, a new genus is erected, resulting in the new combination Langeronyx brodiei. A body size analysis found two independent increases in size in the evolutionary history of rhynchosaurs, one among stenaulorhynchines and the other in the hyperodapedontine lineage. Maximum likelihood fitting of phenotypic evolution models to body size data found ambiguous results, with body size evolution potentially interpreted as fitting either a non-directional Brownian motion model or a stasis model. A Dispersal-ExtinctionCladogenesis analysis reconstructed the areas that are now South Africa and Europe as the ancestral areas of Rhynchosauria and Rhynchosauridae, respectively. The reconstruction of dispersal events between geographic areas that are broadly separated paleolatitudinally implies that barriers to the dispersal of rhynchosaurs from either side of the paleo-Equator during the Middle Triassic were either absent or permeable.Fil: Ezcurra, Martin Daniel. University of Birmingham; Reino Unido. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Montefeltro, Felipe C.. University of Birmingham; Reino Unido. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Butler, Richard J.. University of Birmingham; Reino Unid

    Rising Stars, Superstars and Dying Stars: Hedonic Explorations of Autograph Prices

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    Key studies have explored the economics of rising stars, superstars and ‘has beens’, but relatively little economic literature exists on the associated parallel memorabilia markets. Using a random sample of 1151 pieces of autographed artefacts, on sale through a retail and internet outlet, hedonic analysis is undertaken to elicit significant characteristics in price determination. The data principally consists of autographs of past and current cultural icons along with some sporting and historical figures. We explore, inter alia, price differences with respect to ‘dead’ or ‘alive’ signatories, gender, sphere of fame, nationality, the age of the signatory and the nature of the artefact on which the signature is written. Alternative model specifications have been explored and compared. A notable difference emerges between those autographs with photographs and those without. There are also differences in prices according to whether individuals had been famous for their roles in just films, just television, or in both.

    Detection of benzimidazole carbamates and amino metabolites in liver by surface plasmon resonance-biosensor

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    This research was funded by the Irish Department of Agriculture, Fisheries and Food under the Food Institutional Research Measure as part of the National Development Plan (Project 05/R&D/TN/355)peer-reviewedTwo surface plasmon resonance (SPR) biosensor screening assays were developed and validated to detect 11 benzimidazole carbamate (BZT) and four amino-benzimidazole veterinary drug residues in liver tissue. The assays used polyclonal antibodies, raised in sheep, to detect BZTs and amino-benzimidazoles. A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction method was developed to isolate benzimidazole carbamate residues. Liver samples were extracted using an acetonitrile extraction method. BZTs were purified by dispersive solid phase extraction (d-SPE) using C18 sorbent. Residues of amino-benzimidazoles were effectively cleaned-up using a simple cyclohexane defatting step. The assays were validated in accordance with the performance criteria described in 2002/657/EC. The BZT assay limit of detection was calculated to be 32 ÎŒg kg−1, the detection capability (CCÎČ) was determined to be 50 ÎŒg kg−1 and the mean recovery of analytes was in the range 77–132%. The amino-benzimidazole assay limit of detection was determined to be 41 ÎŒg kg−1, the CCÎČ was determined to be 75 ÎŒg kg−1 and analyte recovery was in the range 103–116%. Biosensor assay performance was tested by analysing liver tissue from animals treated with benzimidazole drugs and comparing the results with an ultra high performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) confirmatory method. All non-compliant samples were identified using the biosensor assays.Department of Agriculture, Food and the Marin

    Modification of Aluminium Surface Using Picosecond Laser for Printing Applications

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    Ultrafast picosecond laser pulses of wavelength of 1064nm have allowed the surface modification of anodised aluminium plate for potential industrial application. The interaction of the laser with the substrate created a hydrophilic surface, giving a contact angle of less than 10 degrees. On examination under a Scanning Electron Microscope (SEM), it was observed that these surfaces have an interesting ‘lotus-leaf’ like structure. It has been found that these laser processed hydrophilic surfaces revert with time. The potential for application in the printing industry is strong due to the reusability and sustainability of the process materials; initial trials confirm this. This technology would offer extra advantages as a non-chemical process without the need for developer, thereby reducing the overall cost and time of printin

    Pourriture phytophthoréenne de la luzerne au Québec : distribution géographique des symptÎmes et étude des facteurs édaphiques pouvant favoriser leur expression

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    Nous avons observĂ© chez la luzerne (Medicago sativa) des symptĂŽmes attribuables Ă  la pourriture phytophthorĂ©enne (Phytophthora megasperma f. sp. medicaginis) dans les 12 rĂ©gions agricoles du QuĂ©bec, avec une prĂ©sence plus marquĂ©e dans l'Outaouais, la Beauce, les Cantons de l'Est, la rĂ©gion de QuĂ©bec et le Nord de MontrĂ©al. Les symptĂŽmes de pourriture Ă©taient plus prĂ©sents dans les dĂ©pressions des luzerniĂšres Ă©chantillonnĂ©es. Nous avons dĂ©terminĂ© la texture et la capacitĂ© de rĂ©tention d'eau des sols Ă©chantillonnĂ©s, et trouvĂ© aucune relation avec la pourriture phytophthorĂ©enne. La culture de cultivars de luzerne rĂ©sistants ou sensibles dans ces sols en serre ne montre pas de diffĂ©rence de maladie. Seulement quatre isolats du Phytophthora megasperma f. sp. medicaginis et un du Phytophthora cryptogea ont Ă©tĂ© obtenus. Lors d'un essai en serre, le trĂšfle rouge (Trifolium pratense) ne fut pas sensible Ă  l'attaque par le P. megasperma f. sp. medicaginis. Le peu de succĂšs Ă  isoler et dĂ©montrer la prĂ©sence du P. megasperma f. sp. medicaginis dans les sols oĂč l'on observe pourtant des symptĂŽmes semblables Ă  ceux de la pourriture phytophthorĂ©enne porte Ă  penser qu'en plus du Phytophthora, d'autres causes comme l'anoxie ou l’Aphanomyces euteiches pourraient en ĂȘtre responsables.Symptoms attributed to Phytophthora root rot (Phytophthora megasperma f. sp. medicaginis) were observed on alfalfa (Medicago sativa) in the 12 agronomic regions of the province of Quebec; they were more severe in the regions of Outaouais, Beauce, the Eastern Townships, Quebec City and the North of Montreal. A greater incidence of the disease was observed in low lying areas. No relationship was found between root rot and water content at field capacity or soil texture. The presence of P. megasperma f. sp. medicaginis was not confirmed by the reaction of susceptible and resistant cultivars ofalfalfa in greenhouse assays. Only four isolates of Phytophthora megasperma f. sp. medicaginis and one of Phytophthora cryptogea were obtained. Red clover (Trifoliumpratense) was not affected by P. megasperma f. sp. medicaginis in a greenhouse trial. The difficulty to detect and isolate Phytophthora in soil samples led to the conclusion that other factors such as anoxia or Aphanomyces euteiches might also be involved

    Treatment of the Enlarged Clitoris

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    Management of the enlarged clitoris, because of its import for sexual function, has been and remains one of the most controversial topics in pediatric urology. Early controversy surrounding clitoroplasty resulted from many factors including an incomplete understanding of clitoral anatomy and incorrect assumptions of the role of the clitoris in sexual function. With a better understanding of anatomy and function, procedures have evolved to preserve clitoral tissue, especially with respect to the neurovascular bundles. These changes have been made in an effort to preserve clitoral sensation and preserve orgasmic potential. It is the goal of this manuscript to describe the different procedures that have been developed for the surgical management of clitoromegally, with emphasis on the risks and benefits of each. Equally important to any discussion of such a sensitive topic is an understanding of long-term patient outcomes. As we will see, despite its importance, there has been a dearth of data in this regard. Future work in the arena of patient satisfaction will undoubtedly play a major role in directing our surgical approach
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