1,370 research outputs found
La technique moderne et la guerre
Au début de l'année 1918, alors que les dernières découvertes de la science et de la technique avaient perfectionné à l'extrême les engins de guerre et étendu au delà de toute prévision les possibilités de destruction, le Comité International de la Croix-Rouge lançait aux belligérants un appel où se trouvait le passage suivant: << Bien loin d'atténuer les maux qu'entraîne la guerre, on peut dire que les progrès de la science dans l'aéronautique, la balistique ou la chimie, n'ont fait qu'en aggraver les souffrances et surtout les étendre à toute la population en sorte que la guerre ne sera bientôt plus qu'une œuvre de destruction générale et sans merc
Rapport technique sur la guerre chimique Annexe au rapport de MM. Cramer et Micheli
Des poisons ayant joué pour la première fois au cours de la guerre mondiale un rôle dans la conduite des opérations militaires, cette question a été vivement discutée, et une série de publications, principalement aussi des articles de la presse quotidienne, ont fait beaucoup de bruit à propos des horreurs des gaz asphyxiants. La Société des Nations et la Croix-Rouge se sont occupées de cette question à plusieurs reprises, et lors de la conférence de Washington, le Ier janvier 1922, une série de grandes puissances tombèrent d'accord pour interdire l'emploi des poisons au cours d'opérations guerrière
FPGA basierte, konfigurierbare OFDM Sender-Plattform für die Positionsbestimmung mittels TDoA
Für die Evaluierung von Algorithmen zur Positionsbestimmung nach dem Time Difference of Arrival – Verfahren wird eine frei konfigurierbare OFDM Sender-Plattform benötigt. Da die Berechnung in Echtzeit erfolgen soll, ist eine Implementierung in rekonfigurierbarer Hardware (FPGA) erforderlich. Das Manuskript
gibt sowohl einen Überblick über die Hintergründe und die Architektur des Sendesystems, als auch einen tieferen Einblick in verschiedene Lösungsdetails
Tambora and the Mackerel Year: Phenology and Fisheries During an Extreme Climate Event
Global warming has increased the frequency of extreme climate events, yet responses of biological and human communities are poorly understood, particularly for aquatic ecosystems and fisheries. Retrospective analysis of known outcomes may provide insights into the nature of adaptations and trajectory of subsequent conditions. We consider the 1815 eruption of the Indonesian volcano Tambora and its impact on Gulf of Maine (GoM) coastal and riparian fisheries in 1816. Applying complex adaptive systems theory with historical methods, we analyzed fish export data and contemporary climate records to disclose human and piscine responses to Tambora’s extreme weather at different spatial and temporal scales while also considering sociopolitical influences. Results identified a tipping point in GoM fisheries induced by concatenating social and biological responses to extreme weather. Abnormal daily temperatures selectively affected targeted fish species—alewives, shad, herring, and mackerel—according to their migration and spawning phenologies and temperature tolerances. First to arrive, alewives suffered the worst. Crop failure and incipient famine intensified fishing pressure, especially in heavily settled regions where dams already compromised watersheds. Insufficient alewife runs led fishers to target mackerel, the next species appearing in abundance along the coast; thus, 1816 became the “mackerel year.” Critically, the shift from riparian to marine fisheries persisted and expanded after temperatures moderated and alewives recovered. We conclude that contingent human adaptations to extraordinary weather permanently altered this complex system. Understanding how adaptive responses to extreme events can trigger unintended consequences may advance long-term planning for resilience in an uncertain future
Different effects of dual task demands on the speech of young and older adults
This is an electronic version of an article published in Kemper, S., Herman, R. E., Nartowicz, J.(2005). Different effects of dual task demands on the speech of young and older adults. Aging, Neuropsychology, and Cognition, 12, 340-358. PM#1410812. Aging, Neuropsychology, and Cognition is available online at www.taylorandfrancis.comYoung and older adults provided language samples in response to elicitation questions while concurrently performing 3 different tasks. The language samples were scored on three dimensions: fluency, grammatical complexity, and content. Previous research has shown that older adults use a restricted speech register that is grammatically less complex than young adults’ and has suggested that this restricted speech register is buffered from the costs of dual task demands. This hypothesis was tested by comparing language samples collected during a baseline condition with those produced while the participants were performing the concurrent tasks. The results indicate that young and older adults adopt different strategies when confronted with dual task demands. Young adults shift to a restricted speech register when confronted with dual task demands. Older adults, who were already using a restricted speech register, became less fluent although the grammatical complexity and informational content of their speech was preserved. Hence, some but not all aspects of older adults’ speech are buffered from dual task demands
A mathematical model for breath gas analysis of volatile organic compounds with special emphasis on acetone
Recommended standardized procedures for determining exhaled lower respiratory
nitric oxide and nasal nitric oxide have been developed by task forces of the
European Respiratory Society and the American Thoracic Society. These
recommendations have paved the way for the measurement of nitric oxide to
become a diagnostic tool for specific clinical applications. It would be
desirable to develop similar guidelines for the sampling of other trace gases
in exhaled breath, especially volatile organic compounds (VOCs) which reflect
ongoing metabolism. The concentrations of water-soluble, blood-borne substances
in exhaled breath are influenced by: (i) breathing patterns affecting gas
exchange in the conducting airways; (ii) the concentrations in the
tracheo-bronchial lining fluid; (iii) the alveolar and systemic concentrations
of the compound. The classical Farhi equation takes only the alveolar
concentrations into account. Real-time measurements of acetone in end-tidal
breath under an ergometer challenge show characteristics which cannot be
explained within the Farhi setting. Here we develop a compartment model that
reliably captures these profiles and is capable of relating breath to the
systemic concentrations of acetone. By comparison with experimental data it is
inferred that the major part of variability in breath acetone concentrations
(e.g., in response to moderate exercise or altered breathing patterns) can be
attributed to airway gas exchange, with minimal changes of the underlying blood
and tissue concentrations. Moreover, it is deduced that measured end-tidal
breath concentrations of acetone determined during resting conditions and free
breathing will be rather poor indicators for endogenous levels. Particularly,
the current formulation includes the classical Farhi and the Scheid series
inhomogeneity model as special limiting cases.Comment: 38 page
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