Stiffness tomography by atomic force microscopy.

The atomic force microscope is a convenient tool to probe living samples at the nanometric scale. Among its numerous capabilities, the instrument can be operated as a nano-indenter to gather information about the mechanical properties of the sample. In this operating mode, the deformation of the cantilever is displayed as a function of the indentation depth of the tip into the sample. Fitting this curve with different theoretical models permits us to estimate the Young's modulus of the sample at the indentation spot. We describe what to our knowledge is a new technique to process these curves to distinguish structures of different stiffness buried into the bulk of the sample. The working principle of this new imaging technique has been verified by finite element models and successfully applied to living cells.

Agents anti-infectieux et fonction réna!e: vers des posologies sur mesure [Antimicrobial agents and renal elimination: towards individual dosage adjustment?].

The efficacy and safety of anti-infective treatments are associated with the drug blood concentration profile, which is directly correlated with a dosing adjustment to the individual patient's condition. Dosing adjustments to the renal function recommended in reference books are often imprecise and infrequently applied in clinical practice. The recent generalisation of the KDOQI (Kidney Disease Outcome Quality Initiative) staging of chronically impaired renal function represents an opportunity to review and refine the dosing recommendations in patients with renal insufficiency. The literature has been reviewed and compared to a predictive model of the fraction of drug cleared by the kidney based on the Dettli's principle. Revised drug dosing recommendations integrating these predictive parameters are proposed.

La conception du "dialogue" de Mikhaïl Bakhtine et ses sources sociologiques (l'exemple des "Problèmes de l'oeuvre de Dostoïevski" [1929])

Résumé: L'article porte sur la conception du « dialogue » de Mikhaïl Bakhtine dans laquelle s'articulent deux groupes d'idées : 1) la notion de « dialogue » en tant que forme de l'interaction verbale interindividuelle (l'échange des répliques) et 2) la notion de « dialogisme » comme principe qui prévoit un rapport particulier entre le « Moi » (le « Je ») et l'« Autrui ». Son but consiste à 1) analyser ces notions au sens de Bakhtine, en s'appuyant sur le texte russe des Problèmes de l'oeuvre de Dostoïevski (1929) ; et à 2) montrer leurs sources sociologiques (principalement russes). Il y est également question de la notion de « polyphonie » introduite par Bakhtine pour caractériser la particularité de la construction des romans de Dostoïevski et d'une facette des réflexions bakhtiniennes sur le rôle de la « polyphonie » chez Dostoïevski, contenues dans le texte russe de 1929, abandonnées dans la version de 1963 et, de ce fait, méconnues des chercheurs francophones n'ayant accès qu'à la traduction des Problèmes de la poétique de Dostoïevski (1963). This paper examines the conception of "dialogue" elaborated by Mikhaïl Bakhtin in which are articulated two groups of ideas : 1) the notion of "dialogue" as a form of verbal interindividual interaction (an exchange of speech) and 2) the notion of "dialogism" as a principle which implies a relation between the "Me" (the "I") and the "Other". Its aim is 1) to analyse these notions in the sens of Bakhtin, on the base of russian text of Problems of Dostoyevsky's Art (1929) and 2) to show their sociological (mainly russian) origins. The paper also deals with the notion of "polyphony" introduced by Bakhtin to characterize the particularity of Dostoyevsky's method of constructing novels and with one facet of bakhtinian reflections (expounded in the text of 1929, omitted in the version of 1963, thereby unknown by francophone researchers who have access only to the translation of Problems of Dostoyevsky's Poetics (1963)) on the role of "polyphony" in Dostoyevsky's works.

A Swiss neighbourhood index of socioeconomic position: Development and Association with Mortality

Background Area-based measures of socioeconomic position (SEP) suitable for epidemiological research are lacking in Switzerland. The authors developed the Swiss neighbourhood index of SEP (Swiss-SEP). Methods Neighbourhoods of 50 households with overlapping boundaries were defined using Census 2000 and road network data. Median rent per square metre, proportion households headed by a person with primary education or less, proportion headed by a person in manual or unskilled occupation and the mean number of persons per room were analysed in principle component analysis. The authors compared the index with independent income data and examined associations with mortality from 2001 to 2008. Results 1.27 million overlapping neighbourhoods were defined. Education, occupation and housing variables had loadings of 0.578, 0.570 and 0.362, respectively, and median rent had a loading of −0.459. Mean yearly equivalised income of households increased from SFr42 000 to SFr72 000 between deciles of neighbourhoods with lowest and highest SEP. Comparing deciles of neighbourhoods with lowest to highest SEP, the age- and sex-adjusted HR was 1.38 (95% CI 1.36 to 1.41) for all-cause mortality, 1.83 (95% CI 1.71 to 1.95) for lung cancer, 1.48 (95% CI 1.44 to 1.51) for cardiovascular diseases, 2.42 (95% CI 1.94 to 3.01) for traffic accidents, 0.93 (95% CI 0.85 to 1.02) for breast cancer and 0.86 (95% CI 0.78 to 0.95) for suicide. Conclusions Developed using a novel approach to define neighbourhoods, the Swiss-SEP index was strongly associated with household income and some causes of death. It will be useful for clinical- and population-based studies, where individual-level socioeconomic data are often missing, and to investigate the effects on health of the socioeconomic characteristics of a place.

Dynamics of F=1 87Rb condensates at finite temperatures

We investigate the dynamics of a F=1 spinor Bose-Einstein condensate of 87Rb atoms confined in a quasi-one-dimensional trap both at zero and at finite temperature. At zero temperature, we observe coherent oscillations between populations of the various spin components and the formation of multiple domains in the condensate. We study also finite temperature effects in the spin dynamics taking into account the phase fluctuations in the Bogoliubov-de Gennes framework. At finite T, despite complex multidomain formation in the condensate, population equipartition occurs. The length scale of these spin domains seems to be determined intrinsically by nonlinear interactions.