Multimodal analysis of synchronization data from patients with dementia

Little is known about the abilities of people with dementia to synchronize bodily movements to music. The lack of non-intrusive tools that do not hinder patients, and the absence of appropriate analysis methods may explain why such investigations remain challenging. This paper discusses the development of an analysis framework for processing sensorimotor synchronization data obtained from multiple measuring devices. The data was collected during an explorative study, carried out at the University Hospital of Reims (F), involving 16 individuals with dementia. The study aimed at testing new methods and measurement tools developed to investigate sensorimotor synchronization capacities in people with dementia. An analysis framework was established for the extraction of quantity of motion and synchronization parameters from the multimodal dataset composed of sensor, audio, and video data. A user-friendly monitoring tool and analysis framework has been established and tested that holds potential to respond to the needs of complex movement data handling. The study enabled improving of the hardware and software robustness. It provides a strong framework for future experiments involving people with dementia interacting with music

Localization of Secondary Metabolites in Marine Invertebrates: Contribution of MALDI MSI for the Study of Saponins in Cuvierian Tubules of H. forskali

BACKGROUND: Several species of sea cucumbers of the family Holothuriidae possess a particular mechanical defense system called the Cuvierian tubules (Ct). It is also a chemical defense system as triterpene glycosides (saponins) appear to be particularly concentrated in Ct. In the present study, the precise localization of saponins in the Ct of Holothuria forskali is investigated. Classical histochemical labeling using lectin was firstly performed but did not generate any conclusive results. Thus, MALDI mass spectrometry Imaging (MALDI-MSI) was directly applied and completed by statistical multivariate tests. A comparison between the tubules of relaxed and stressed animals was realized. RESULTS: These analyses allowed the detection of three groups of ions, corresponding to the isomeric saponins of the tubules. Saponins detected at m/z 1287 and 1303 were the most abundant and were apparently localized in the connective tissue of the tubules of both relaxed and stressed individuals. Saponins at m/z 1125 and 1141 were detected in lower amount and were present in tissues of relaxed animals. Finally, saponin ions at 1433, 1449, 1463 and 1479 were observed in some Ct of stressed holothuroids in the outer part of the connective tissue. The saponin group m/z 14xx seems therefore to be stress-specific and could originate from modifications of the saponins with m/z of 11xx. CONCLUSIONS: All the results taken together indicate a complex chemical defense mechanism with, for a single organ, different sets of saponins originating from different cell populations and presenting different responses to stress. The present study also reflects that MALDI-MSI is a valuable tool for chemical ecology studies in which specific chemical signalling molecules like allelochemicals or pheromones have to be tracked. This report represents one of the very first studies using these tools to provide a functional and ecological understanding of the role of natural products from marine invertebrates

Qualitative and Quantitative Saponin Contents in Five Sea Cucumbers from the Indian Ocean

To avoid predation, holothuroids produce feeding-deterrent molecules in their body wall and viscera, the so-called saponins. Five tropical sea cucumber species of the family Holothuriidae were investigated in order to study their saponin content in two different organs, the body wall and the Cuvierian tubules. Mass spectrometry techniques (MALDI- and ESI-MS) were used to detect and analyze saponins. The smallest number of saponins was observed in Holothuria atra, which contained a total of four congeners, followed by Holothuria leucospilota, Pearsonothuria graeffei and Actinopyga echinites with six, eight and ten congeners, respectively. Bohadschia subrubra revealed the highest saponin diversity (19 congeners). Saponin mixtures also varied between the two body compartments within a given animal. A semi-quantitative approach completed these results and showed that a high diversity of saponins is not particularly correlated to a high saponin concentration. Although the complexity of the saponin mixtures described makes the elucidation of their respective biological roles difficult, the comparisons between species and between body compartments give some clues about how these molecules may act as predator repellents

Direct tissue MS/MS analysis of the saponin ions at <i>m/z</i> 1287.

<p>Characteristic signature peaks of saponins (<i>m/z</i> 507 and <i>m/z</i> 523) are marked by an asterisk.</p

Molecular structures of saponins from the Cuvierian tubules of <i>Holothuria forskali</i>.

<p>Isomeric congeners are presented in columns (a) and (b). Structures and corresponding names are from Van Dyck <i>et al. </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0013923#pone.0013923-Vandyck1" target="_blank">[17]</a>.</p

Repartition of saponin groups depending on the state of stress.

<p>(A) Optical image of sections through bundles of Cuvierian tubules. The red dots depict the positions at which each mass spectrum was acquired. (B, C and D) Visualization of signal intensity for the group of saponins at <i>m/z</i> 1125 and 1141 (B); the group of saponins at <i>m/z</i> 1287 and 1303 (C); and the group of saponins at <i>m/z</i> 1433, 1449, 1463 and 1479 (D) in tubule frozen sections from stressed (left part) or relaxed (right part) individuals.</p

Complete list of saponins detected by MALDI Direct Tissue Analysis of a Cuvierian tubule section in <i>Holothuria forskali</i>.

<p>Complete list of saponins detected by MALDI Direct Tissue Analysis of a Cuvierian tubule section in <i>Holothuria forskali</i>.</p

MALDI-Imaging results shown in false colour representation.

<p>The color intensity reflects intensities of the selected mass signals: green, ions at <i>m/z</i> 843 used as a counterstain; red, the different saponin ions for which the <i>m/z</i> ratios are indicated below the images.</p