Visite du site d'expérimentation sur les effets du changement climatique de Saint-Michel-l'Observatoire (O3HP) -

Le colloque "Observer et s'adapter au changement climatique en forêt méditerranéenne" a été organisé, entre autre, dans le cadre du projet européen For Climadapt. Il a été l'occasion de proposer, avec l'Office national des forêts, autre partenaire français du projet, une tournée forestière consacrée à la visite du site pilote de la forêt de Nans, dans les Alpes-Maritimes. Le compte rendu de cette journée a été rédigé par l'Association Internationale Forêts Méditerranéennes, autre partenaire français du projet

“Savages Who Speak French”: Folklore, Primitivism and Morals in Robert Hertz

Hertz's analysis of the Alpine cult of Saint Besse apparently marks a break from his studies of death, sin and the left to folkloric studies. This analysis helps one to understand the personality of Robert Hertz. His sociological curiosity about folklore reveals his ambiguous position in social sciences at the beginning of the twentieth century. His text appears to be a variation from the Durkheimian norm, but another reading could suggest that Hertz continued and went beyond Durkheimian thought to something between sociology of the modern world and engaged socialism. Through this study, Hertz linked his political ideals, his work in ethnology and his desire for social involvement. The cult of Saint Besse perpetuated as much religious tradition as local identity. The Alpine people were presented in the text as wilful perpetuators of an ideal social order, whose loss for his contemporary city dwellers Hertz feared. The alpine Other, marked by a material and moral backwardness, represented for activist and socialist Hertz one of the paths of balanced social organization that stabilized the identity of a group across time if it fit rather well into the folkloric stereotypes of the beginning of the twentieth century. Finally, by linking events in Herz's life (e.g., the accidental Alpine death of his father), this article suggests that the legend of Saint Besse embodied several recurring motifs in Hertz' career: the accidental deaths of saint and father by falls, the military role of the saint and of Hertz himself

Gd(III) polyaminocarboxylate chelate: realistic manybody molecular dynamics simulations for molecular imaging applications

Realistic molecular dynamics simulations of polyaminocarboxylate complexes of gadolinium (III) ion in water are performed, providing coordination numbers and average residence times in quantitative agreement with available experimental data. A theoretical analysis, based on fitting a fluctuating charges model on ab initio data, also indicates that charge transfer between the ion and the ligand is significant

Effects of contrast, cut-off spatial frequency and phase of the OTF on visual acuity and subjective image quality score

Póster presentado al 6th EOS Topical Meeting on Visual and Physiological Optics celebrado en Dublin (Irlanda) del 20 al 22 de agosto de 2012.We evaluated the separated effects of a loss of contrast, sharpness, phase and a pure defocus on high-contrast tumbling-E visual acuity (VA) and subjective quality of image, by means of an adaptive optics visual simulator. [Introduction]: Retinal images suffer from optical blur, given by the Optical Trans-fer Function (OTF). Its modulus (the MTF) expresses the loss of contrast and sharpness (cut-off spatial frequency, COF), whereas its phase describes spatial shifts between frequencies (phase shift). These are the main factors affecting optical image quality, and hence they induce a loss of visual acuity and quality of vision. The aim of this experiment was to evalu-ate the effects of these three factors (contrast, cut-off frequency and phase) separately. The COF is a scalar variab-le, but contrast and phase are 2D functi-ons in general. To somehow convert them to scalar variables, the contrast was assumed constant within the frequency interval 0 < f < COF; the phase of the OTF was that of a pure defocus, given in diopters. In this way a synthetic OTF was obtained combining that phase with a MTF, which was a cylinder with radius COF, and height given by the contrast (plus a delta function at f = 0). We calculated the appearance of images on 5 -mm pupil diameter, degraded either by a loss of contrast (i.e. 1; 0.5; 0.25; 0.12 and 0.06) or by a lower cut-off spatial frequency (i.e. 50; 25; 12 and 6 c/deg) or by the phase shifts (i.e. 0.05; 0.10; 0.25; 0.5; 0.75; 1; 1.25; 1.5 diopters of pure defocus for 5 mm pupil). As a reference, these synthetic degradations were compared to that caused by pure defocus (modulus and phase), for the same diopters.[Discussion]: We measured these effects on degraded high-contrast tumbling-E visual acuity and on subjective score. Five subjects, aged between 22 and 40 years, scored three times the quality of each simulated image (three 0.4 logMar letters) using a continuous 5-items grading scale according to the ITU recommendations. Their visual acuities under the various conditions were also measured three times. To limit the degradation due the observer’s eye optics, the simulated images were viewed through a dynamic correction of aberrations (CRX1TM, Imagine Eyes) and an artificial pupil of 3mm. They were displayed on an EmaginTM micro display coupling with a colour filter ensuring a monochromatic light (i.e. 550 ± 50nm). The averaged intra-individual standard deviation (SD) was 0.03 logMar and 0.15 grade, the larger difference of SD between sub-jects and type of degradation was observed with image quality score. The averaged inter-individual SD was 0.03 logMar and 0.27 (dimensionless) grade. These SD were largely under clinical signifi-cant difference (i.e. 0.1 logMar and a difference of grade of 1). We normalized the results to obtain respectively the best and worst VA corresponding to the best and worst score for the defocus condition (see figure 2a). When lowering the COF, only the sharpness of the letter is degrading. [Conclusions]: The cut-off frequency induces a comparable loss of VA and subjec-tive score. However, a loss of contrast or phase shift appeared to have a more detrimental effect on VA than on subjective score. Considering a given loss of VA, we are subjectively more affected by a phase shift or loss of contrast than by a loss of sharpness (lower COF) or a pure defocus error.Peer reviewe

A Bayesian Model to Describe Factors Influencing Trough Levels of Vancomycin in Hemodialysis Patients

International audienceBACKGROUND/AIMS: In hemodialysis patients, there is a marked inter-individual variability in the pharmacokinetics of vancomycin. This retrospective study was carried out to design a model describing the parameters that may influence the trough concentrations of vancomycin (TCV) in hemodialysis patients. METHODS: A Bayesian model was constructed from data obtained during 314 hemodialysis sessions performed in 31 hemodialysis patients receiving vancomycin. The model's validity was assessed by goodness of fit. A bootstrap resampling method was used to calculate bias and accuracy for 80 predicted and observed TCV. RESULTS: A total of 31 patients underwent dialysis 3 times a week for a mean duration of 4 h. Their mean age was 69 +/- 12 years. The vancomycin infusion was started 30 min before the scheduled end of the dialysis session at a flow rate of 1,000 mg/h. The mean TCV of the study population was 16.1 +/- 3.2 mg/l. The area under receiver operating characteristic curve of the constructed model was 95.2%. In the validation sample (80 randomly selected TCV), the observed mean TCV was 15.8 +/- 3.6 mg/l, whereas the mean TCV predicted by the model was 15.7 +/- 3.0 mg/l. If the mean bias was low between the predicted and observed TCV (-0.1 mg/l), SD was high (3.43 mg/l). The variables most closely linked to TCV were in descending order: weight after dialysis, weight before dialysis, the dose of vancomycin administered during the previous dialysis session and creatinine concentration before dialysis. CONCLUSION: This simple model describes patient-related and dialysis-related parameters that mainly influence TCV. Before its use in clinical practice, this model should be validated prospectively