The aim of this study was to investigate the effect of some cellulose polymers mixed in a semipermanent dyestuff on the dye uptake of yak hair fiber and color fading after repeated washing cycles. Two different classes of commercial polymers were tested: non-ionic and cationic. Formulations based on a mixture of HC and basic dyes, with different molecular sizes, were employed as representative dyestuffs. UV-Vis spectroscopy and colorimetric measurements were used to analyze the extracted dyes from the yak hair cuticle and cortex. The results obtained indicate that the presence of cationic polymers in the dye bath improves both the quality of the dyeing process and the antifading effect during the first washing cycles.

Our external appearance plays a key role in everyday life's social interactions. Hence, taking care of our appearance allows us to adjust and protect ourselves, as well as communicate emotional disposition (i.e. sympathy or aversion) and social information (i.e. values, status). However, some discrete body parts or characteristics appear to be more salient than others in contributing to global body image. For example, authors showed that facial attractiveness is one of the best predictors of overall physical attractiveness and represent one of the primary factors influencing global self-esteem. Make-up is therefore ought to play a major influence in these parameters. Moreover, in a previous study whose subject was to explain the reasons that motivate women to make-up, we showed a high implication of specific psychological traits in correlation with two make-up functions (i.e. psycho-behavioural profiles 'Seduction' and 'Camouflage'; group S and group C, respectively). The purpose of this study was to assess the possible relation between our two psycho-behavioural profiles and some morphological parameters know to be involved in facial attraction (i.e. facial asymmetry and skin visual quality). First of all, our study revealed for women from the group C a greater asymmetry of the lower face (i.e. mouth area) that could be related to a possible larger amount of negative emotional experiences. Concerning make-up behaviour, women from the group S more extensively manipulated their relative facial attractiveness, by using a large range of colours, but also through a significantly longer make-up process used to adjust their visual asymmetry and therefore increase their potential of attractiveness. On the overall, our results suggest that make-up is used differentially, according to stable psychological profiles of women, to manipulate specific visual/morphological facial features involved in attractiveness.

The questionnaire constructed from this brainstorming session allowed volunteers and experts to judge their perception of skin radiance more precisely. Video imaging appears as an interesting method to quantify visual properties of the skin and to visualize what the consumer perceives of skin radiance. However, the mathematical model proposed from the skin surface parameters analysis does not totally explain the global perception of skin radiance. In the future, it will be necessary to develop new data-processing programs to quantify subjective parameters in order to validate our mathematical model.

Objective. The aim of this study was to compare fMRI analysis of somatosensory areas activated by passive touch, to cognitive analysis of the psychological profile of human subjects. Methods. The study was carried out on 21 females, after informed consent. Two artificial textures (smooth and rough), and two natural textures (the skin of an operator modified or not by a cosmetic product), were applied on the fingers of the subjects. A period of imagination to be touched was also included in the study. MR images of the somatosensory cortex were acquired on a 1.5T MRI system during the different behavioral conditions. Series of images were first processed to compensate for the inter-frame motions and then activation was assessed with a statistical method based on conditional analysis. After the MRI protocol, each subject was interviewed following a questionnaire from which psychological descriptors were extracted. Results. 1) Activations were quite similar for all textures in the contralateral sensory areas 2) In the ipsilateral sensory areas, activations were more important in response to a stimulation with the skin of an operator than with artificial textures. The activation was even more important after application of a cosmetic product on the skin. 3) Imagination of the tactile stimulation resulted in an activation mostly localized in the ipsilateral cortex. 4) A PLS analysis assessed that 2 psychological descriptors, rationality and sensorial reactivity, were related to an activation in the contralateral cortex, while 2 others, imagination and sensitivity, were related to ipsilateral areas activation. Conclusion. fMRI and cognitive analysis allowed us to map the physical component of the tactile perception in the contralateral cortex. This study also gave rise to a better understanding of the activation in ipsilateral areas, which was found to be mainly related to the subjective component of the stimulation.

The two systems are similar in terms of repeatability and reproducibility, with some differences in sensibility. The data measured by the MEMS sensor appear lower than those measured by the thermocouple. After make-up, the MEMS sensor detects a progressive increase of the temperature in time whereas the thermocouple detects a decrease. We found the same evolution on the face but in a more attenuated way. These results tend to show that the devices do not measure the same phenomenon. The thermocouple appears more sensitive to the thermal response of the made-up surface whereas the MEMS sensor appears more sensitive to the heat transfers in the interface between the skin and make-up.