The goal of a body-machine interface (BMI) is to map the residual motor skills of the users into efficient patterns of control. The interface is subject to two processes of learning: while users practice controlling the assistive device, the interface modifies itself based on the user's residual abilities and preferences. In this study, we combined virtual reality and movement capture technologies to investigate the reorganization of movements that occurs when individuals with spinal cord injury (SCI) are allowed to use a broad spectrum of body motions to perform different tasks. Subjects, over multiple sessions, used their upper body movements to engage in exercises that required different operational functions such as controlling a keyboard for playing a videogame, driving a simulated wheelchair in a virtual reality (VR) environment, and piloting a cursor on a screen for reaching targets. In particular, we investigated the possibility of reducing the dimensionality of the control signals by finding repeatable and stable correlations of movement signals, established both by the presence of biomechanical constraints and by learned patterns of coordination. The outcomes of these investigations will provide guidance for further studies of efficient remapping of motor coordination for the control of assistive devices and are a basis for a new training paradigm in which the burden of learning is significantly removed from the impaired subjects and shifted to the devices.

The Raman spectra of approximately 20 reference samples of cobalt-based green and violet artists' pigments of various provenance (present day manufactory, historical reference pigments and samples from a contemporary artist's studio) were acquired to assist in the identification of unknown cobalt-based pigments in works by Pablo Picasso (1881-1973) and Jasper Johns (b. 1930. Specifically, Raman spectra were obtained for various cobalt titanate greens (Co 2 TiO 4 ), highlighting variability in peak positions because of ionic substitutions in the spinel structures of such pigments. The Raman spectra of the cobalt violet pigments magnesium cobalt arsenate (Mg x Co 3-x (AsO 4 ) 2 ) and hydrated forms, ammonium cobalt phosphate hydrate (NH 4 CoPO 4 *H 2 O), and anhydrous cobalt phosphate, Co 3 (PO 4 ) 2 were also recorded; some of which are presented here for the first time. Fourier Transform Infrared spectroscopy (FTIR), x-ray fluorescence spectrometry (XRF) and x-ray diffraction (XRD) were employed to confirm the composition of the reference materials. An optimal technique to characterize microscopic cross sections from the studied artworks is Raman microscopy, which can also provide valuable information on the hydration states of the examined phases. The multi-analytical methodology allowed the identification of the unknown green pigment used by Jasper Johns as cobalt titanate green (C.I. PG 50); representing the first documented occurrence of this pigment in the palette of a renowned contemporary artist. Both magnesium cobalt arsenate (in anhydrous and hydrated forms) and anhydrous cobalt phosphate were identified in the Picasso painting.This research advances the knowledge of 20th century synthetic inorganic pigments used by artists and documents their usage in actual works of art.

This study reports the multi-analytical investigation of ready-mixed house paints used by artists such as Pablo Picasso (1881-1973) in the first half of the twentieth century. The pigment composition of paint swatches on four historic paint sample cards from the Art Institute of Chicago reference collection was characterized by thorough screening using Fourier transform infrared (FT-IR) and X-ray fluorescence (XRF) spectroscopies, followed by Raman spectroscopy when necessary. Spectroscopic investigations highlighted the dominance of zinc-based whites, the consistent choice of particular pigments or their mixtures, as well as the avoidance of others to achieve the various hues on the sample cards. Notable findings included the documentation of strong spectroscopic signatures of metal soaps. Given the similarities in composition of early twentieth century artists' and house paints, the results indicate that the identification of house paints in works by Pablo Picasso and others must be based on a combination of parameters rather than the detection of a single chemical marker. Results have been applied to the case study of Picasso's 1935 sculpture Figure (AIC 1988.428), which incorporates direct evidence of the use of house paint by the artist.

 National Gallery of Art  Independent conservation scientist Ripolin -a popular French house paint -was used extensively by Pablo Picasso and some of his contemporaries. Its presence in particular artworks, however, has been difficult to confirm scientifically due to the chemical similarities between Ripolin and contemporary artist's tube paints, and the lack of knowledge about Ripolin paint formulations. This study compares data collected from a large reference set of historical samples of Ripolin and artist's tube paints with new analytical results from two Picasso paintings in the collection of the Art Institute of Chicago suspected to contain Ripolin: Still Life () and The Red Armchair (). A variety of non-invasive and micro-invasive analytical techniques, including x-ray fluorescence spectroscopy, Fourier transform infrared spectroscopy, fiber-optics reflectance spectroscopy ( to  nm), Raman spectroscopy, optical and polarized light microscopy, and scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy, were used to analyze the paint samples. The results indicate that Still Life does not contain Ripolin, as it has pigments, such as vermilion and lead white, and extenders, such as barium sulfate, not used in French Ripolin house paints. On the other hand, The Red Armchair has paints matching closely with samples of Ripolin Blanc de neige, used alone and mixed with artist's tube colors.