Correlation of processing, microstructure, and superplasticity in an Al-MG-ZR alloy

Investigation of the influence of the strain history during thermomechanical processing of an Al-10Mg-0.1Zr was conducted. Refined, recrystallized microstructures resulted when larger strains were employed in the later passes of the TMP. Superplastic responses up to approximately 420 percent were obtained. Conversely, when smaller strains were at the later stages of the TMP, less recrystallized, coarser structures resulted, and the corresponding superplastic ductilities of approximately 280 percent were obtained.http://archive.org/details/correlationofpro00lyleLieutenant, United States NavyApproved for public release; distribution is unlimited

Fort Conger: A Site of Arctic History in the 21st Century

Fort Conger, located at Discovery Harbour in Lady Franklin Bay on northern Ellesmere Island, Nunavut, played an intrinsic role in several High Arctic expeditions between 1875 and 1935, particularly around 1900–10 during the height of the Race to the North Pole. Here are found the remains of historic voyages of exploration and discovery related to the 19th century expeditions of G.S. Nares and A.W. Greely, early 20th century expeditions of R.E. Peary, and forays by explorers, travelers, and government and military personnel. In the Peary era, Fort Conger’s connection with indigenous people was amplified, as most of the expedition personnel who were based there were Inughuit from Greenland, and the survival strategies of the explorers were largely derived from Inughuit material cultural and environmental expertise. The complex of shelters at Fort Conger symbolizes an evolution from the rigid application of Western knowledge, as represented in the unsuitable prefabricated Greely expedition house designed in the United States, towards the pragmatic adaptation of Aboriginal knowledge represented in the Inughuit-influenced shelters that still stand today. Fort Conger currently faces various threats to its longevity: degradation of wooden structures through climate and weathering, bank erosion, visitation, and inorganic contami­nation. Its early history and links with Greenlandic Inughuit have suggested that the science of heritage preservation, along with management practices of monitoring, remediation of contamination, and 3D laser scanning, should be applied to maintain the site for future generations.Fort Conger, situé au Havre de la découverte, dans la baie Lady Franklin, au nord de l’île d’Ellesmere, au Nunavut, a joué un rôle intrinsèque dans plusieurs expéditions de l’Extrême-Arctique entre 1875 et 1935, surtout dans les années 1900 à 1910, à l’apogée de la course vers le pôle Nord. Nous trouvons ici les vestiges de voyages d’exploration et de découvertes historiques, vestiges qui se rapportent plus précisément aux expéditions de G.S. Nares et d’A.W. Greely au XIXe siècle, aux expéditions de R.E. Peary au début du XXe siècle et aux incursions de divers explorateurs, voyageurs, militaires et employés du gouvernement. À l’époque de R.E. Peary, les liens entretenus avec les Autochtones de Fort Conger se sont intensifiés, car une grande partie des membres de l’expédition étaient des Inughuits du Groenland, et les stratégies de survie des explorateurs dépendaient grandement de l’expertise matérielle, culturelle et environnementale des Inughuits. Le complexe d’abris qui se trouve au Fort Conger symbolise une évolution, où l’on a délaissé l’application rigide des connaissances occidentales, comme en atteste la maison préfabriquée inadaptée conçue aux États-Unis pour l’expédition Greely, pour aller vers une adaptation pragmatique des connaissances autochtones, comme l’illustrent les abris d’influence inughuite que l’on aperçoit toujours de nos jours. En ce moment, la longévité de Fort Conger est menacée en raison de la dégradation des structures en bois, dégradation attribuable à l’altération climatique et atmosphérique, à l’érosion des berges, aux visites et à la contamination inorganique. Les débuts de Fort Conger et ses liens avec les Inughuits groenlandais suggèrent qu’il y aurait lieu de mettre en application la science de la conservation du patrimoine, jumelée aux pratiques de gestion de la surveillance, de restauration des matériaux contaminés et de balayage laser 3D, afin d’assurer le maintien du site pour les générations à venir

Application of 3D Laser Scanning to the Preservation of Fort Conger, a Historic Polar Research Base on Northern Ellesmere Island, Arctic Canada

Fort Conger, located in Quttinirpaaq National Park, Ellesmere Island, is a historic landmark of national and international significance. The site is associated with many important Arctic expeditions, including the ill-fated Lady Franklin Bay Expedition of the First International Polar Year and Robert Peary’s attempts to claim the North Pole. Although situated in one of the most remote locations on earth, Fort Conger is currently at risk because of the effects of climate change, weather, wildlife, and human activity. In this paper, we show how 3D laser scanning was used to record cultural features rapidly and accurately despite the harsh conditions present at the site. We discuss how the future impacts of natural processes and human activities can be managed using 3D scanning data as a baseline, how conservation and restoration work can be planned from the resulting models, and how 3D models created from laser scanning data can be used to excite public interest in cultural stewardship and Arctic history.Fort Conger, situé dans le parc national Quttinirpaaq, sur l’île d’Ellesmere, est un lieu historique d’importance nationale et internationale. Ce site est lié à de nombreuses expéditions arctiques importantes, dont l’infortunée expédition de la baie Lady Franklin relevant de la première année polaire internationale et les tentatives de revendication du pôle Nord par Robert Peary. Bien qu’il se trouve dans l’un des endroits les plus éloignés du globe, Fort Conger subit actuellement les risques découlant des effets du changement climatique, des conditions météorologiques, de la faune et de l’activité humaine. Dans cette communication, nous montrons comment un scanneur laser 3D a permis de répertorier les caractéristiques culturelles avec rapidité et précision malgré les conditions difficiles qui ont cours à ce site. Nous discutons de la manière dont les incidences futures des processus naturels et de l’activité humaine peuvent être gérées à l’aide des données 3D comme données de base, comment les travaux de conservation et de restauration peuvent être planifiés à partir des modèles qui en résultent et comment les modèles 3D créés à partir des données de scannage laser peuvent rehausser l’intérêt du grand public à l’égard de la gérance culturelle et de l’histoire de l’Arctique

Structure of the Endonuclease Domain of MutL: Unlicensed to Cut

DNA mismatch repair corrects errors that have escaped polymerase proofreading, increasing replication fidelity 100- to 1000-fold in organisms ranging from bacteria to humans. The MutL protein plays a central role in mismatch repair by coordinating multiple protein-protein interactions that signal strand removal upon mismatch recognition by MutS. Here we report the crystal structure of the endonuclease domain of Bacillus subtilis MutL. The structure is organized in dimerization and regulatory subdomains connected by a helical lever spanning the conserved endonuclease motif. Additional conserved motifs cluster around the lever and define a Zn2+-binding site that is critical for MutL function in vivo. The structure unveils a powerful inhibitory mechanism to prevent undesired nicking of newly replicated DNA and allows us to propose a model describing how the interaction with MutS and the processivity clamp could license the endonuclease activity of MutL. The structure also provides a molecular framework to propose and test additional roles of MutL in mismatch repair.American Cancer Society (Research Professor)Natural Sciences and Engineering Research Council of Canada (NSERC scholarship)National Institutes of Health (U.S.) (CA21615)National Institutes of Health (U.S.) (GM45190)Natural Sciences and Engineering Research Council of Canada (NSERC, 288295)Deutsche Forschungsgemeinschaft (FR-1495/4-1)University of Michigan (Start-up funds

VITALITY trial: protocol for a randomised controlled trial to establish the role of postnatal vitamin D supplementation in infant immune health

Introduction Postnatal vitamin D supplementation may be associated with a reduction in IgE-mediated food allergy, lower respiratory tract infections and improved bone health. Countries in the Northern hemisphere recommend universal infant vitamin D supplementation to optimise early vitamin D levels, despite the absence of large trials proving safety or efficacy for any disease outcome. With the aim of determining the clinical and cost-effectiveness of daily vitamin D supplementation in breastfed infants from age 6–8 weeks to 12 months of age, we have started a double-blind, randomised, placebo-controlled trial of daily 400 IU vitamin D supplementation during the first year of life, VITALITY. Methods nd analysis Infants (n=3012) who are fully breastfed and not receiving vitamin D supplementation will be recruited at the time of their first immunisation, from council-led immunisation clinics throughout metropolitan Melbourne, Australia. The primary outcome is challenge-proven food allergy at 12 months of age. Secondary outcomes are food sensitisation (positive skin prick test), number of lower respiratory infections (through hospital linkage), moderately-severe and persistent eczema (by history and examination) and vitamin D deficiency (serum vitamin D <50 nmol/L) at age 12 months. The trial is underway and the first 130 participants have been recruited