1000 resultados para Davis, Henry Winter, 1817-1865.
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The human genome encodes the blueprint of life, but the function of the vast majority of its nearly three billion bases is unknown. The Encyclopedia of DNA Elements (ENCODE) project has systematically mapped regions of transcription, transcription factor association, chromatin structure and histone modification. These data enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions. Many discovered candidate regulatory elements are physically associated with one another and with expressed genes, providing new insights into the mechanisms of gene regulation. The newly identified elements also show a statistical correspondence to sequence variants linked to human disease, and can thereby guide interpretation of this variation. Overall, the project provides new insights into the organization and regulation of our genes and genome, and is an expansive resource of functional annotations for biomedical research.
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Monthly newsletter for the Iowa Department of Public Health
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It is intuitively obvious that snow or ice on a road surface will make that surface more slippery and thus more hazardous. However, quantifying this slipperiness by measuring the friction between the road surface and a vehicle is rather difficult. If such friction readings could be easily made, they might provide a means to control winter maintenance activities more efficiently than at present. This study is a preliminary examination of the possibility of using friction as an operational tool in winter maintenance. In particular, the relationship of friction to traffic volume and speed, and accident rates is examined, and the current lack of knowledge in this area is outlined. The state of the art of friction measuring techniques is reviewed. A series of experiments whereby greater knowledge of how friction deteriorates during a storm and is restored by treatment is proposed. The relationship between plowing forces and the ice-pavement bond strength is discussed. The challenge of integrating all these potential sources of information into a useful final product is presented together with a potential approach. A preliminary cost-benefit analysis of friction measuring devices is performed and suggests that considerable savings might be realized if certain assumptions should hold true. The steps required to bring friction from its current state as a research tool to full deployment as an operational tool are presented and discussed. While much remains to be done in this regard, it is apparent that friction could be an extremely effective operational tool in winter maintenance activities of the future.
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L'épuisement des énergies fossiles est un thème d'actualité dont les prémices datent, selon l'opinion courante, des années 1970 et du premier choc pétrolier. En réalité, c'est une préoccupation plus ancienne, intimement liée à l'ère industrielle. Dans la deuxième partie du XIXème siècle, les économistes se sont penchés sur la question de l'épuisement des minerais, 'objet non identifié' jusqu'alors et nécessitant la mise sur pied de nouveaux outils d'analyse (effet-rebond chez Jevons, rente minière chez Marshall-Einaudi notamment). Avec le progrès des techniques et l'apparition de nouvelles énergies (pétrole, hydro-électricité), leurs craintes de déclin industriel se sont progressivement dissipées dans les années 1910 et 1920. Mais ces évolutions tenant à l'histoire des faits ne sont pas les seules à considérer. Des facteurs internes à la discipline économique, comme l'émergence du marginalisme dans les années 1870 et de la théorie de l'épargne et du capital dans les années 1890, ont aussi changé le regard des économistes sur la question de l'épuisement des ressources. Pourquoi ? Comment ? Quels enseignements peut-on en tirer pour les défis environnementaux d'aujourd'hui ? Voilà les questions qui sont traitées dans ce travail de thèse.
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The use of abrasives in winter maintenance is a well-established practice. The sand or other abrasive is intended to increase friction between vehicles and the (often snow or ice covered) pavement. In many agencies (and in many Iowa Counties, the focus of this study) the use of sand is a standard part of winter maintenance. Yet very little information exists on the value of sanding as a winter maintenance procedure. Some studies suggest that friction gains from sanding are minimal. In addition, there are increasing environmental concerns about sanding. These concerns focus on air quality and stormwater quality issues. This report reviews the state of the practice of abrasive usage in Iowa Counties, and classifies that usage according to its effectiveness. Possible changes in practice (with respect to abrasive usage) are presented and discussed.
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Titre original : His Majesties instructions to his dearest sonne, Henry the prince