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Les deux auteurs sont, l’un, cinéaste et l’autre réalisateur de télévision. Ils enseignent à Genève dans le domaine des médias et de la communication. À ce titre, ils comparent ici l’itinéraire personnel qui les a amenés à investir l’enseignement des médias. Dans le cadre de deux lieux de formation, et à partir d’expériences initiales différentes, des convergences de thèmes et de préoccupations pédagogiques leur apparaissent significatives. « Les interrogations sont multiples, tout comme les champs de savoirs spécialisés susceptibles d’y répondre. Dès lors quelle est la marge de manoeuvre laissée à ceux qui, tout en ne se prétendant pas savants en la matière, s’efforcent de ne pas être dupes ? », The two authors are professionally active in the medias: one as filmmaker, the other as television director. They also give courses on media and communication in Geneva. In this article they compare their itineraries that led them to teaching. Their work situations are quite different as were their initial experiences in the field and yet they find that there are significant points of convergence concerning the themes and teaching methods that they prefer. "The questions are multiple and the fields of knowledge that can help to answer them are just as varied. How can one attempt to respond to this necessity of multidisciplinarity without being superficial?" The authors attempt to furnish some ideas that can help answer this question., Ambos autores, cineasta uno y realizador de televisión el otro, enseñan en Ginebra en el campo de los medios de comunicación. En relación a esta función, ellos comparan los caminos personales que los han llevado a dedicarse a este tipo de enseñanza. Dos lugares de formación diferentes y experiencias iniciales también diferentes, les parece sin embargo que han producido convergencias de temas y de preocupaciones pedagógicas significativas. "Los interrogantes son muchos, así como lo son los campos del saber aptos a responder a ellos. ¿Cuál es, por lo tanto, el margen de maniobra disponible para los que, sin pretender ser sabios en la materia, tratan de evitar de engañarse?"

Im Anschluss an die dringlichen Massnahmen des Bundes auf dem Gebiete der Raumplanung, vorn 17. Marz 1972, zeigte sich das Bedurfnis, eine das ganze Land umfassende, einheitliche Ubersicht uber den Wert einzelner Landschaften unter den Gesichtspunkten des Naturschutzes zu erstellen. Mit dieser Aufgabe betrauten die Abteilung Natur- und Heimatschutz des eidgenossischen Oberforstinspektorates und der Delegierte fur Raumplanung die Pflanzengeographische Kommission der Schweizerischen Naturforschenden Gesellschaft. Wegen der verhaltnismassig geringen Mittel und der sehr knappen Zeit, mit der fur die Ausfuhrung einer solchen Ubersicht gerechnet werden konnte, war es notwendig, die anzuwendende Methode sowohl mit Bezug auf die pro Flacheneinheit einzusetzende Zeit als auch auf die mogliche Differenzierung der Resultate so effizient als moglich zu gestalten. Es war deshalb naheliegend, den Einsatz der elektronischen Datenverarbeitung von Anfang an als zentrale Methode einzuplanen.

People in chronic phase of traumatic brain injury (TBI) are often told that there will be no further recovery in brain function, that they are in a "static phase." Holistic Approach to NeuroDevelopment and Learning Efficiency (HANDLE), an alternative therapy, aims to improve function by teaching a series of physical and mental activities that clients perform and encouraging changes in lifestyle. Five subjects (3 males) with chronic TBI (at least 3 years since ictus) completed the HANDLE Institute's program and were prospectively evaluated. Each had six regional cerebral blood flow (rCBF) single-photon emission computed tomography (SPECT) scans over 7 months (scans n= 30). Paired scans were performed with injection of Tc-99m ECD to image rCBF at rest and during the HANDLE "Crossed Arm Bounce" (CAB) exercise before the program, at 3-4 months into the program, and at 6-7 months, after the program had ended. SPECT images were analyzed statistically using Neurostat in which image sets were coregistered and warped into Talaraich atlas for pairwise subtraction between conditions. Group analysis of SPECT showed that CAB activated (increased rCBF) vermis and cerebellar hemispheres in first two paired scans and anterior cingulate and vermis on the final pair. Increased rCBF at rest occurred in cerebellar hemispheres, vermis, and right dorsomedial frontal cortex. These preliminary observations suggest that there may be a role of the hindbrain (vermis and cerebellum) with HANDLE treatment of chronic TBI.

Summary In 14 permanent plots at four distant sites in the European Alps life tables, cohorts and recruitment of Eritrichium nanum were studied during a period of 5 resp. 6 years. The germination rates were tested in the Botanical Institute of the University of Basel and besides the life tables of the plots at natural habitats we followed the early stages of development in pot cultures at the University Botanical Garden in Basel. Most of the seedlings of E. nanum emerged in spring, in the pot cultures as well as under natural conditions, a behavior which confirms general findings. But the germination rates (0–30%) were markedly low. The pot cultures show that some seeds are after 4 or 5 years still viable. Premature flowering in the second summer is a rather common behavior of E. nanum seedlings, which happened in all the cohorts observed during five years, partly up to 20% of the total of living plants in the corresponding plots. It is evident that life expectancy of E. nanum plants increase rapidly with rising size, to such a degree that cushions of only 10–20 cm 2 surface have a survival chance of more than 70%, those of 20–30 cm 2 even of more than 95% during a period of 5 years. But it has to be mentioned that juvenile plants are not growing parallel to their lifetime, many of them persist during several years in the size categories I/II (0–5 cm 2 ), while others suddenly arise from category I to III (–10 cm 2 ) or even IV (–20 cm 2 ), what is mostly caused by joining, a specific type of safe site strategy. Though not obligatory, juvenile plants growing close together, often add their sizes to form one larger cushion, which was found to be particularly advantageous for recruitment. This is obviously a primary strategy of E. nanum and favors, especially on bare ground, the survival of its descendants which was found higher than expected (average of 26% after 5 years’ growth at natural habitats). Focusing on the whole life cycle of E. nanum , the present studies show constraints in pollination, a small seed production and low germination rates to be well compensated by the high survivorship and successful recruitment of the seedlings.

Flower development, pollination and breeding system of the high alpine cushion plant, Eritrichium nanum (Boraginaceae), were investigated in nine populations from the European Alps at altitudes of 2700 m–3200 m. Peak flowering period lasts longer than a month, from mid-June to the end of July. In contrast to statements in the literature that flowers are protogynous and nutlets remain in their calyx until spring we found a distinct protandry and nutlets being dispersed before mid-September. Various insects from 12 families, but mostly Diptera, frequently visited E. nanum flowers, with flies from the families Anthomyiidae and Muscidae being the predominant visitors. Under optimal conditions (max. solar radiation, min. wind force), visitation rates of 200 simultaneously observed flowers reached 32.5–46.7 insects per hour, i.e. 0.16–0.24 insects per flower per hour. However, the commonly observed Anthomyiidae and Muscidae clearly preferred the white-yellowish flowers of Saxifraga exarata and Saxifraga bryoides which are abundant at E. nanum sites and which are certainly also pollinated by species of these two fly families. The flowers of these Saxifraga species offer plenty of nectar and may compete for pollinators with E. nanum, when they are flowering in its proximity. However, various other insects like Pontia callidice and Psodos sp. (Lepidoptera) as well as Andrena sp. (Hymenoptera) and especially Eristalis tenax and closely related hoverflies showed a higher degree of flower constancy to E. nanum, often flying from a blue Eritrichium cushion to the next and hence causing outcrossing. The five fornices of E. nanum flowers which obstruct the tube containing stamens and nectar, are a feature which differs distinctly from the syndrome of fly-pollinated flowers with easily accessible nectar. Consequently pollination by flies in E. nanum seems to be caused mainly by the unfavorable ecological conditions at high altitudes, where flies are the most frequent insects. Bagging experiments showed that outcrossing and geitonogamy are the prevailing pollination modes, and autogamy, although possible, plays only a minor role.

Weekly aerosol samples have been collected and analyzed consistently at Mauna Loa Observatory from February 1979 through June of 1991. Previous studies reported data through April of 1985. This paper focuses mainly on the data from May 1985 to June 1991. However, previous data have been included when appropriate to examine the entire data record. Elemental concentrations, enrichment factors, principal component analysis and chemical mass balancing have been used to examine this 12 year data record. Yearly Asian dust episodes are the major contributor to trace metal concentrations and variance. Marine material contributes only a third of the trace metal mass compared to the crustal contribution. Anthropogenic and biogenic material usually contribute less than 5% of the trace element mass (excluding carbon and sulfate). Sulfate, which was measured by ion chromatography for part of the period, contributes a mass similar to crustal mineral; however, it does not have a strong seasonal pattern. A pollution episode in 1989 increased the budget of several elements by an order of magnitude or more. The trace acidic gas data support the conclusion that marine material in the free troposphere has been weathered, leading to a chlorine depletion in marine particles.

A recent study of the elemental composition of particulate material collected from the plumes of five copper smelters in southeastern Arizona indicated that arsenic, lead, selenium, cadmium, zinc, tungsten, indium, and other chalcophilic elements are highly enriched in the plume materials relative to the background aerosol. Enrichments are due to the volatilization of these elements during copper smelting. Significant differences in the elemental compositions of plumes from the various smelters appear to be due to differences in the feed material, smelting conditions, and equipment use by the smelters. (3 graphs, 13 references, 7 tables)

Atmospheric samples were collected during warm and cold weather conditions at continental, coastal and marine sites. Source sampling was performed at a coal-fired power plant and several volcanic sites. Atmospheric gas-phase and particulate boron concentrations were determined by neutron capture prompt-gamma activation analysis and compared to measurements from other studies. Rain and snow samples collected at one continental site were analysed for soluble and insoluble B. Volcanic deposit and ash samples were also analysed for B. The tropospheric burdens for particulate and gas-phase B were estimated to be 0.6 × 1010 g and (6–11) × 1010 g, respectively, with the latter about a factor of 3 lower than previous estimates. Global anthropogenic particulate and gas-phase B source estimates were consistent with previous estimates, and natural particulate and gas-phase B source estimates agreed reasonably well with previously reported upper limits. About 65–85 % of total B source strength can be attributed to the oceans, and 8–20% to coal, agricultural, fuelwood and refuse burning. Volcanism may contribute 6–15% of the total, but accurate source estimates are difficult. Total global B removal from the atmosphere by wet and dry deposition was estimated to be (530–700) × 1010 g yr−1, a factor of 2 lower than previously reported but in fairly good agreement with the global total B source estimate of (200–530) × 1010 g yr−1.

Previous studies have shown that small particles emitted from waste incinerators are enriched in many elements, e.g. Na, Cl, Br, Cu, Zn, As, Ag, Cd, In, Sn, Sb, W and Ph. Experiments were done to determine the water solubility of elements on in-stack cascade-impactor and whole-filter samples collected at a municipal incinerator. Na, Cs, K, Zn, Cl, Br, Cd and Pb were all very soluble. Solubilities range from 63% for Zn to 100% for Cl, and increase with decreasing particle size. Other elements associated with small particles and those on larger particles, i.e. Cu, As, In, Sn, Sb, W, Au, Al, Ti, Sc, La, V, Cr, Fe, Mn, Co and Se are mostly insoluble (

Hantavirus infections are known in Germany since the 1980s. While the overall antibody prevalence against hantaviruses in the general human population was estimated to be about 1–2%, an average of 100–200 clinical cases are recorded annually. In the years 2005 and 2007 in particular, a large increase of the number of human hantavirus infections in Germany was observed. The most affected regions were located in the federal states of Baden-Wuerttemberg, Bavaria, North Rhine Westphalia, and Lower Saxony. In contrast to the well-documented situation in humans, the knowledge of the geographical distribution and frequency of hantavirus infections in their rodent reservoirs as well as any changes thereof was very limited. Hence, the network “Rodent-borne pathogens” was established in Germany allowing synergistic investigations of the rodent population dynamics, the prevalence and evolution of hantaviruses and other rodent-associated pathogens as well as their underlying mechanisms in order to understand their impact on the frequency of human infections. A monitoring of hantaviruses in rodents from endemic regions (Baden-Wuerttemberg, Bavaria, North Rhine Westphalia, Lower Saxony) and regions with a low number of human cases (Mecklenburg Western-Pomerania, Brandenburg, Saxony, Saxony-Anhalt) was initiated. Within outbreak regions, a high prevalence of Puumala virus (PUUV) was detected in bank voles. Initial longitudinal studies in North Rhine Westphalia (city of Cologne), Bavaria (Lower Bavaria), and Lower Saxony (rural region close to Osnabruck) demonstrated a continuing presence of PUUV in the bank vole populations. These longitudinal studies will allow conclusions about the evolution of hantaviruses and other rodent-borne pathogens and changes in their distribution, which can be used for a risk assessment of human infections. This may become very important in order to evaluate changes in the epidemiology of rodent-borne pathogens in the light of expected global climate changes in the future.

DMT1 is a transmembrane protein which transports the divalent metal ions Fe2+, Zn2+, Cu2+ and Mn2+. Although DMT1 has been functionally linked to duodenal absorption and cellular utilisation of iron hardly anything is known about its distribution and potential role within the human glandular system.Two polyclonal antibodies were raised to study the expression of DMT1 in tissues obtained from human corpus by the means of immunocytochemistry and Western blotting.All antibodies specifically detected a 60 kD protein band referring to human DMT1. Significant amounts of DMT1 expression were detected on the luminal site of organs, which are involved in excretion/re-absorption processes, such as salivary glands, pancreas, biliary tract and gallbladder.Our results suggest that DMT1 may be of pivotal importance for the regulation of metal ion homeostasis within organs involved in absorption and excretion of ions.

In patients with ovarian carcinoma, an hematocrit-independent hyperviscosity syndrome is often present. The syndrome is characterized by normal or low hematocrit and hemoglobin concentration, an elevated platelet count, and an increase in clotting factor turnover. Because deep vein thrombosis (DVT) often complicates the course of ovarian carcinoma, the aim of this study was to investigate the possible association of hyperviscosity syndrome with the development of DVT.Rheologic estimations of the blood included red blood cell (RBC) aggregation (stasis and low shear), plasma viscosity (pv), blood cell count, and fibrinogen, which were performed before primary surgery and the beginning of perioperative heparin thrombosis prophylaxis on 63 of 65 patients with Stage I-IV ovarian malignancy (according to the staging criteria of the International Federation of Gynecology and Obstetrics). Two patients who had had DVT 5-6 weeks in advance of the study were excluded from rheologic calculations. Thrombosis screening by impedance plethysmography was performed the day before primary major surgery; postoperatively on Days 1, 3, 5, 7, and 10; before each of 6 cycles of chemotherapy (once every 3 weeks); and thereafter once every 3 months during follow-up. All blood tests were also performed on 72 healthy women and 29 patients with benign ovarian tumor the day prior to surgery.All ovarian carcinoma patients, including 7 patients with tumors of low malignant potential, were eligible for surgery, and all except those with Stage IV disease (n = 12) were macroscopically tumor free after surgery. Before surgery, RBC aggregation, pv, and platelet and fibrinogen concentrations were significantly higher (P0.05) in cancer patients than in either of the control groups, whereas hemoglobin (hb) and hematocrit (hct) were significantly lower in cancer patients than in healthy women (P0.001). Platelet, leukocyte, and fibrinogen concentrations were significantly correlated to disease stage, whereas pv, RBC aggregation, hb, and hct were not. The preoperative pv was significantly higher in patients who later developed DVT (n = 17; 1.46+/-0.13 mPas; P = 0.01) than in those who did not (1.34+/-0.14 mPas). Of all estimated preoperative variables, only pv was a significant risk factor for postoperative and subsequent DVT (RR: 29.84; 95% CI: 1.076-827.16; P = 0.04).Our results confirm the presence of a hematocrit- and stage-independent hyperviscosity syndrome in untreated ovarian carcinoma patients. In addition, a high preoperative plasma viscosity was a significant risk factor for the development of DVT in the postoperative period and even thereafter.

Particle and gas samples were collected at Mauna Loa volcano during and after its eruption in March and April, 1984 and at Kilauea volcano in 1983, 1984, and 1985 during various phases of its ongoing activity. In the last two Kilauea sampling missions, samples were collected during eruptive activity. The samples were analyzed by INAA for over 40 elements. We have found Ir in samples collected at Kilauea and Mauna Loa during fountaining activity as well as after eruptive activity. Os was also seen in the Mauna Loa samples. Enrichment factors for Ir in the volcanic fumes range from 10/sup 4/ to 10/sup 5/ relative to BHVO. Flux calculations for Ir at Mauna Loa and Kilauea had ranges of 80 to 3000 and 10 to 315 g/d respectively. The percentage of Ir released from the magma into the fumes ranged from 1% to 12% for both volcanoes. Calculations assuming the Deccan as the source of Ir for the K/T boundary layer show that the concentration of Ir left in the basalts may be too low to account for all of the K/T Ir. It would require a very high fraction (> 30%) of the Ir to be purged from themore » basalt to account for all the Ir, which cannot be supported by the Hawaiian data. 26 refs., 1 fig., 4 tabs.« less

A general introduction to the current state of knowledge of the long- range transport of trace elements is given in Chapter 2 (p. 37). In this chapter we present four case studies to illustrate our level of understanding of the processes and to draw attention to the gaps in the current knowledge. Each case has been treated differently to reflect the complexity of the case and the available data base. The approaches we used are exploratory and our results, preliminary. However, these results do illustrate ways in which we might improve our undertanding of the processes involved in long-range transport. The themes common to each case are explored in the final section.

Throughout the earth’s geological history trace elements have been atmospherically transported from continent to continent and from continent to ocean; this long-range atmospheric transport is now recognized as an important, if not the most important, mode of global transport for a variety of trace substances ad elements. The anthropogenic trace substances found in remote locations attest to the rapidity and extent of such transport.

Dust storms in Asia's interior deserts loft immense quantities of continental crust that are blown over the North Pacific Ocean every year. The transported mineral aerosol is first lofted and then experiences mixing and fallout during the transport. Its elemental signature is no longer that of bulk soil. The concentration for many elements is greater in transported crust compared to bulk soil due to a difference in mineralogy of the small crustal particle. Small particles are defined as those below 100 μ m in diameter. The elements Al, Mg, Ca and Na do not experience an internal concentration change with particle size. Many of the elements in the MLO mineral aerosol have concentrations that are greater than 1.5 times that of bulk soil. Iron, an important biological agent, has twice the concentration in the MLO mineral aerosol than in bulk soil. The elemental to Al concentration ratios observed are consistent, implying that the transported crustal material is below 20 μ m in diameter. DOI: 10.1034/j.1600-0889.1996.00008.x

Aerosol samples were collected at the Mauna Loa Observatory in Hawaii from February 1979 to May 1985. The samples were analyzed via instrumental neutron activation analysis (INAA) for up to 47 elements and via ion chromatography for sulfate. The data are dominated by crustal dust that arrives via long-range transport from Asia each spring, thus creating a “dust season.” Of the 47 elements detected, 37 have a notably higher mass average during the dust season. The data record is explored using enrichment factors, principal component analysis, and chemical mass balances (receptor modeling). The crustal material accounts for 60–70% of the overall aerosol mass during dust seasons, yet only 15–20% during nondust seasons. It is by far the largest contributor to the natural variation dominating the principal component analysis by describing greater than 60% of the overall variance. Particulate sulfate is another major component accounting for 10–40% of the aerosol mass during dust seasons and 60–75% of the mass during nondust seasons. Particulate sulfate can be derived from crustal material and sea salt. Anthropogenic activity also can produce particulate sulfate or its precursors that can adhere to the surface of crustal material that travels over a polluted area. Minor components in the downslope winds are marine sea-salt aerosol contributing less than 3% of the aerosol mass during the dust season and 5–6% during the nondust season. Local basalt is considered to contribute less than 2% during the dust season and 3–4% during the nondust season. (Carbon mass is not determined and therefore no carbon-based aerosols such as soot or organic aerosols are considered in the total aerosol mass.)

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Particle and gas samples were obtained before and after eruptive episode 35 in July and August 1985 at the fuming Pu'u O'o vent, Kilauea volcano, Hawaii. The sampling system employed consisted of a particle filter followed by four {sup 7}LiOH treated filters to collect acidic gases. The filters were analyzed using instrumental neutron activation analysis (INAA). The results indicate that Br/Cl and Re/Cl ratios do not fluctuate through an eruption cycle but the F/Cl, F/Br and metal/Cl ratios (In and Cd) do change through the cycle. An inverse relationship between F/Cl and metal/Cl was observed. The changes are probably due to influxes of relatively undegassed magma during the repose period releasing fume with lower F/Cl, F/BR and higher metal/Cl ratios. As the magma in the Pu'u O'o conduit gradually degasses either before or several days after an eruptive episode, F/Cl and F/Br ratios increase and the metal/Cl ratios decrease. One sample collected on July 24, two days before eruptive episode 35, did not follow this general trend. This can be explained by a gas pulse from a deeper, less degassed portion of magma making its way to the top of the conduit.

A sampling and analysis procedure is described for determining vapor-phase concentrations of As, Se, Br, I, and Hg in the stack of a coal-fired power plant. The percentages of the total in-stack concentrations for these elements present in the vapor phase are as follows: Br, 98%; Hg, 98%; Se, 59%; As, 0.7-52%; and I, greater than or equal to99%. A lower limit of 99% was obtained for Cl. The vapor-phase concentration of As appears to be dependent upon the in-stack or filter mass loading. This indicates that a vaporization-condensation mechanism may control the vapor-phase concentrations of As. The result for Se indicate that the efficiency of the electrostatic precipitator affects particle vapor-phase fractionation. The results obtained in this study are compared with previous mass balance calculations.