Partir de soi, rencontrer l'autre--quelques réflexions sur la formation de psychiatre [The self and the other: a few comments on psychiatric education].

This manuscript has served for an oral presentation in honour of Professor Pierre Bovet who retired from his position as head physician at the Department of Psychiatry of the Lausanne University Hospital, Switzerland. Pierre Bovet has focused his clinical and scientific interest and his teaching activities on the schizophrenic spectrum disorders. The author tries to describe the essential elements of a clinical attitude which allows to really encounter the patient.

Determination of chemical composition and its relationship with optical properties of Ti-N and Ti-V-N sputtered thin films

In the investigation of thin films of transition metal nitrides, an essential role is played by the accurate determination of their chemical composition. Actually the chemical composition depends on the deposition parameters and influences the optical properties. These relations are illustrated in thin films of TiNx and (Ti1-yVy)N-x deposited by reactive magnetron sputtering from composite targets of the elements. By variation of the nitrogen partial pressure and the target composition, different samples have been obtained. The chemical composition has been measured by electron probe microanalysis at low irradiation voltages. The optical properties are evaluated by ex-situ ellipsometry. Using the screened Drude model, they are correlated with the differences in composition. Adding vanadium or nitrogen in Ti-N is shown to have the same effect on the optical properties.

Chemical and carbon isotopic evolution of hydrocarbons during prograde metamorphism from 100°C to 550°C: Case study in the Liassic black shale formation of Central Swiss Alps

Hydrocarbon distributions and stable isotope ratios of carbonates (delta(13)C(car), delta(18)O(car)), kerogen (delta(13)C(ker)), extractable organic matter (delta(13)C(EOM)) and individual hydrocarbons of Liassic black shale samples from a prograde metamorphic sequence in the Swiss Alps were used to identify the major organic reactions with increasing metamorphic grade. The studied samples range from the diagenetic zone (< 100 degrees C) to amphibolite facies (similar to 550 degrees C). The samples within the diagenetic zones (< 100 and 150 degrees C) are characterized by the dominance of C-< 20 n-alkanes, suggesting an origin related with marine and/or bacterial inputs. The metamorphic samples (200 to 550 degrees C) have distributions significantly dominated by C-12 and C-13 n-alkanes, C-14, C-16 and C-18 n-alkylcyclopentanes and to a lesser extend C-15, C-17 and C-21 n-alkylcyclohexanes. The progressive C-13-enrichment (up to 3.9 parts per thousand) with metamorphism of the C-> 17 n-alkanes suggests the occurrence of cracking reactions of high molecular weight compounds. The isotopically heavier (up to 5.6 parts per thousand) C-< 17 n-alkanes in metamorphic samples are likely originated by thermal degradation of long-chain homologous with preferential release of isotopically light C-1 and C-2 radicals. The dominance of specific even C-number n-alkylcyclopentanes suggests an origin related to direct cyclization mechanism (without decarboxylation step) of algal or bacterial fatty acids occurring in reducing aqueous metamorphic fluid conditions. The regular increase of the concentrations of n-alkylcycloalkanes vs. C-> 13 n-alkanes with metamorphism suggests progressive thermal release of kerogen-linked fatty acid precursors and degradation of n-alkanes. Changes of the steroid and terpenoid distributions are clearly related to increasing metamorphic temperatures. The absence of 18 alpha(H)-22,29,30-trisnorneohopane (Ts), the occurrence of 17 beta(H)-trisnorhopane, 17 beta(H), 21 alpha(H)-hopanes in the C-29 to C-31 range and 5 alpha(H),14 alpha(H),17 alpha(H)-20R C-27, C-29 steranes in the low diagenetic samples (< 100 degrees C) are characteristic of immature bitumens. The higher thermal stress within the upper diagenetic zone (150 degrees C) is marked by the presence of Ts, the disappearance of 17 beta(H)-trisnorhopane and thermodynamic equilibrium of the 22S/(22S + 22R) homohopane ratios. The increase of the alpha alpha alpha-sterane 20S/(20S + 20R) and 20R beta beta/(beta beta + alpha alpha) ratios (from 0.0 to 0.55 and from 0.0 to 0.40, respectively) in the upper diagenetic zone indicates the occurrence of isomerization reactions already at < 150 degrees C. However, the isomerization at C-20 (R -> S) reaches thermodynamic equilibrium values already at the upper diagenesis (similar to 150 degrees C) whereas the epimerisation at C-14 and C-17 (alpha alpha ->beta beta) arrives to constant values in the lower anchizone (similar to 200 degrees C). The ratios Ts vs. 17 alpha(H)-22,29,30-trisnorneohopane [(Ts/(Ts + Tm)] and 18 alpha(H)-30-norneohopane (C29Ts) vs. 17 alpha(H),21 beta(H)-30-norhopane [C29Ts/(C29Ts + C-29)] increase until the medium anchizone (200 to 250 degrees C) from 0.0 to 0.96 and from 0.0 to 0.44, respectively. An opposite trend owards lower values is observed in the higher metamorphic samples. The occurrence of specific hydrocarbons (e.g., n-alkylcyclopentanes, cadalene, hydrogenated aromatic compounds) in metamorphic samples points to kerogen degradation reactions most probably occurring in the presence of water and under reducing conditions. The changes of hydrocarbon distributions and carbon isotopic compositions of n-alkanes related to metamorphism suggest that the organic geochemistry may help to evaluate the lowest grades of prograde metamorphism. Copyright (c) 2005 Elsevier Ltd.