Global heat flow trends resolved from multiple geological and geophysical proxies

International audienceBecause global coverage of heat flow measurements is still poor in many areas, empirical estimators based on the geology, the thermotectonic age or the velocity structure of the upper mantle have often been used to affect an estimate to regions where such measurements are absent. On the basis of the assumption that heat flow is strongly related to its geodynamic environment, one may integrate multiple proxies derived from a large body of global geo- logical and geophysical data sets assembled during the past decades; these should help to better capture the variety of present-day settings. This idea is illustrated through two simple empirical methods: both of them are based on a set of examples, where heat flow measure- ments are associated with relevant terrestrial observables such as surface heat production, upper-mantle velocity structure, tectono-thermal age, on a 1◦ × 1◦ grid. To a given target point owning a number of observables, the methods associate a heat flow distribution rather than a deterministic value to account for intrinsic variability and uncertainty within a defined geodynamic environment. The 'best combination method' seeks the particular combination of observables that minimizes the dispersion of the heat flow distribution generated from the set of examples. The 'similarity method' attributes a weight to each example depending on its degree of similarity with the target point. The methods are transparent and are able to handle sets of observables that are not available over the whole Earth (e.g. heat production). The resulting trends of the mean heat flow deduced from the two methods do not differ strongly, but the similarity method shows a better accuracy in cross-validation tests. These tests suggest that the selected proxies have the potential to recover at least partly medium- to large-scale features of surface heat flow. The methods depict the main global trends of low heat flow in stable and ancient regions, and thermal high in active orogens and rift zones. Broad thermal anomalies are outlined in the Sahara and in the tectonically active eastern part of Antarctica. The similarity method estimates a continental heat loss of 13.6 ± 0.8 TW (2σ uncertainty), which is consistent with previous estimates

Measuring the Surface Thermal Structure of the Sea off Brittany by Ship and Aircraft

During the months of September and October 1975 the “Laboratoire d ’Océanographie Physique de l’Université de Bretagne Occidentale” (LOP) and the “Laboratoire de Météorologie Dynamique du C.N.R.S.” (LMD) made a joint study of surface temperatures and their variability over the continental plateau off the westernmost point of Brittany. Between 18 September and 28 October scientists from the LOP made several trips aboard the oceanographic vessel Capricorne operating a sonde for in-situ T.S.D. measurements. The LMD utilized an Aries radiometer which they themselves had designed and perfected. This was installed aboard a DC-3 aircraft that also carried pressure, humidity and temperature sensors. Our two objectives were as follows : 1. To compare the results obtained by two different techniques; 2. To obtain details of certain aspects of the microstructure of the sea surface, in particular over a frontal region. This paper thus proposes : a) To compare the results of the bathysonde measurements carried out by the LOP on Capricorne with those of a team from the “ Centre Océanologique de Bretagne" (COB) embarked in the oceanographic vessel Cry os from 16 to 29 September 1975. b) To present charts derived from radiometric measurements and to compare these charts with previous ones. c) To present aspects of the fine thermal structure at the surface from a certain number of radial passes with the DC-3

Rationalité économique et division du travail. Le cas de l'industrie pétrolière

La place des activités de recherche dans l'entreprise fait l'objet aujourd'hui de nombreuses analyses. F. X. Raillard et J. M. Saussois étudient ici le cas des firmes pétrolières et les transformations de leur politique d'exploration. Ils montrent les liens qui existent entre les orientations globales de la firme et le processus de division du travail. Ils insistent tout particulièrement sur la dépendance croissante des géologues et chercheurs aux administratifs, sur les conflits qui s'y greffent quand l'entreprise s'étant constitué un capital technique d'exploration, diversifie ses activités.Raillard F. X., Saussois Jean-Michel. Rationalité économique et division du travail. Le cas de l'industrie pétrolière. In: Sociologie du travail, 16ᵉ année n°2, Avril-juin 1974. pp. 141-155

Neuronal current imaging: An experimental method to investigate electrical currents in dogs with idiopathic epilepsy.

BACKGROUND The diagnosis of idiopathic epilepsy (IE) in dogs is based on exclusion of other potential causes of seizures. Recently, a novel magnetic resonance imaging (MRI) sequence that utilizes a variant of the rotary saturation approach has been suggested to detect weak transient magnetic field oscillations generated by neuronal currents in humans with epilepsy. HYPOTHESIS/OBJECTIVES Effects on the magnetic field evoked by intrinsic epileptic activity can be detected by MRI in the canine brain. As proof-of-concept, the novel MRI sequence to detect neuronal currents was applied in dogs. ANIMALS Twelve dogs with IE and 5 control dogs without a history of epileptic seizures were examined. METHODS Prospective case-control study as proof-of-concept. All dogs underwent a clinical neurological examination, scalp electroencephalography, cerebrospinal fluid analysis, and MRI. The MRI examination included a spin-locking (SL) experiment applying a low-power on-resonance radiofrequency pulse in a predefined frequency domain in the range of oscillations generated by the epileptogenic tissue. RESULTS In 11 of 12 dogs with IE, rotary saturation effects were detected by the MRI sequence. Four of 5 control dogs did not show rotary saturation effects. One control dog with a diagnosis of neuronal ceroid lipofuscinosis had SL-related effects, but did not have epileptic seizures clinically. CONCLUSIONS AND CLINICAL IMPORTANCE The proposed MRI method detected neuronal currents in dogs with epileptic seizures and represents a potential new line of research to investigate neuronal currents possibly related to IE in dogs

Datenbanksystem zur Bestandesbetreuung von Milchviehherden mit Schwerpunkt auf der Eutergesundheit

In der Michviehhaltung ist die integrierte tierärztliche Bestandsbetreuung (ITB) eine wirksame Methode, um Gesundheitsprobleme wie Mastitis und Fruchtbarkeitssörungen langfristig zu bekämpfen. Um den Zeitaufwand und die Kosten für die ITB zu optimieren, müssen entsprechende technische Hilfmittel vorhanden sein, die eine schnelle und komfortable Datenverarbeitung gewährleisten und praxistaugliche Beratungstools zu Verfügung stellen. Das Forschungsinstitut für biologischen Landbau (FiBL) hat ein solches Datenbanksystem für das Bestandsbetreuungsprojekt "Pro-Q" entwickelt. Ziel der Datenbank ist, extern zur Verfügung stehende und selbst erhobene Daten zu gebündelten Informationen auf Herden- und Einzeltierebene (inkl. Euterviertelebene) zusammenzubringen und Landwirt, Tierarzt und Berater regelmässig zur Verfügung zu stellen. Diese erhalten so einen umfassenden Überblick über die Gesundheit der Herde und des Einzeltieres. Die Datenbank erlaubt den gleichzeitigen Zugriff durch mehrere Benutzer. Fernzugriff via Internet ist ebenfalls möglich. In diesem Beitrag sollen die wesentlichen Komponenten im Hinblick auf die Tauglichkeit in praxi dargelegt werden

Study of physico-chemical mechanisms for modeling the influence of operating conditions in a PCO indoor air treatment device

International audienc