Hardy Bacterium Isolated From Two Geographically Distinct Spacecraft Assembly Cleanroom Facilities

Earlier studies have confirmed that a tenacious hardy bacterial population manages to persist and survive throughout a spacecraft assembly process. The widespread detection of these organisms underscores the challenges in eliminating them completely. Only comprehensive and repetitive microbial diversity studies of geographically distinct cleanroom facilities will bolster the understanding of planetary protection relevant microbes. Extensive characterizations of the physiological traits demonstrated by cleanroom microbes will aid NASA in gauging the forward contamination risk that hardy bacteria (such as Tersicoccus phoenicis) pose to spacecraft. This study reports on the isolation and identification of two gram-positive, non-motile, non-spore-forming bacterial strains from the spacecraft assembly facilities at Kennedy Space Center, Florida, USA and Centre Spatial Guyanais, Kourou, French Guiana. DNA-DNA relatedness values between the novel strains indicates that these novel strains were indeed members of a same species. Phylogenetic evidence derived from a 16S ribosomal DNA analysis indicated that both the novel strains are less closely related to all other Arthrobacter species

Comparison of LASTIC (Light Aspiration device for in vivo Soft TIssue Characterization) with classic Tensile Tests.

International audienceLASTIC is a device estimating in vivo soft tissue elasticity. It uses negative pressure to deform the tissue surface and captures several deformation stages to trace the behavioral curve. Using Finite Element inverse analysis and a Neo Hookean constitutive law, the tissue's Young modulus is evaluated. This paper compares LASTIC capabilities with standard tensile tests on four samples with elastic properties ranging from 10 kPa to 100 kPa. Although LASTIC overestimates Young modulus by an average of 24 %, it allows a first estimation of the elastic modulus of different materials

The Control of Token-toToken Variability: an Experimental and Modeling Study

Abstract. The articulatory token-to-token variability in the production of German vowels is investigated with simultaneous EMMA and EPG recordings. The potential role of physical constraints, such as the contacts between tongue and palate measured by EPG, and the biomechanical properties of the tongue, simulated with a 2D finite element model is evaluated. Our results suggest that the control of high front vowels makes use of the palatal contacts, while the variability of low vowels is essentially oriented along the main axis of deformation of the tongue, the high/front-to-low/back direction

In vivo and ex vivo percutaneous absorption of [14C]-bisphenol A in rats: a possible extrapolation to human absorption?

Bisphenol A (BPA) is a monomer used mainly in the synthesis of polycarbonates and epoxy resins. Percutaneous absorption is the second source of exposure, after inhalation, in the work environment. However, studies on this route of absorption are lacking or incomplete. In this study, percutaneous BPA absorption was measured in vivo and ex vivo in the rat, and ex vivo in humans. An approximately 12-fold difference in permeability between rat skin and human skin was found, with permeability being higher in the rat. In addition, inter- and intra-individual variability of up to tenfold was observed in humans. No accumulation of BPA in the skin was found during exposure. The skin clearance rate following exposure was estimated at 0.4 μg/cm²/h. Ex vivo and in vivo percutaneous absorption fluxes of BPA in the rat were in the same range (about 2.0 μg/cm²/h), suggesting that extrapolation to the in vivo situation in humans may be possible. The European tolerable daily intake (TDI) of BPA is 50 μg/kg body weight. However, many research projects have highlighted the significant effects of BPA in rodents at doses lower than 10 μg/kg/day. A 1-h occupational exposure over 2,000 cm² (forearms and hands) may lead to a BPA absorption of 4 μg/kg/day. This is 8% of the European TDI and is very close to the value at which effects have been observed in animals. This absorption must therefore be taken into account when evaluating risks of BPA exposure, at least until more relevant results on the toxicity of BPA in humans are available

Validation de LASTIC (Light Aspiration device for in vivo Soft TIssue Characterization) sur des élastomères

National audienceLe dispositif LASTIC repose sur le principe d'aspiration par pipette : l'instrument mesure à l'aide d'une mini caméra les déplacements induits par la génération contrôlée d'une dépression locale à la surface du matériau. Un premier prototype a évalué le comportement de la peau, la langue et plus récemment du cerveau 1. Une nouvelle version 2 a été développée afin de rendre le dispositif (1) stérilisable et (2) capable de fournir en moins d'une minute une estimation des paramètres matériaux. Cette nouvelle version est validée ici en comparant avec des essais mécaniques classiques. LASTIC est un cylindre métallique de 33×34mm divisé en deux compartiments (cf. Fig. 1 à gauche). Le compartiment inférieur est étanche à l'air, avec une ouverture circulaire en bas et fermée au sommet par une fenêtre en verre. Le compartiment supérieur supporte une caméra 2 mégapixels. Plusieurs niveaux de dépression ΔP sont générés dans le compartiment inférieur par une pompe programmable, et sont mesurées par un manomètre numérique. Le matériau ainsi aspiré est imagé par la caméra grâce à un miroir incliné à 45°. L'ensemble du dispositif est contrôlé et synchronisé par un ordinateur. La déformation, mesurée comme la hauteur d'aspiration, est segmentée sur chaque image de la mesure et convertie en mm. Une analyse éléments finis basée sur un modèle néo-Hookéen permet de construire un abaque de hauteurs de déplacement en fonction de la dépression et du comportement du matériau 3. Une méthode de minimisation aux moindres carrés est alors utilisée avec cet abaque pour estimer les propriétés mécaniques correspondant aux mesures. Des expériences ont été menées sur quatre matériaux silicones différents pour simuler la gamme d'élasticité des tissus mous humains : RTV#1, RTV#2, Ecoflex, et gel de bougie. Pour chaque matériau, des éprouvettes de traction uniaxiale et une éprouvette spécifique pour LASTIC ont été réalisées. Figure 1. Vue en coupe de LASTIC : la partie supérieure contient la caméra tandis que la chambre d'aspiration et le miroir sont dessous (gauche). Modules de Young déterminés par LASTIC et les machines de traction pour chaque matériau (droite). La Figure 1 résume les pentes initiales (équivalent à des modules d'Young) estimées par LASTIC et par traction uniaxiale. Dans l'ensemble, malgré une surestimation systématique moyenne de 24% par rapport aux machines de traction standards, LASTIC donne une bonne estimation des propriétés des matériaux hyperélastiques isotropes. À terme ce dispositif pourra être utilisé sur des patients pendant des interventions chirurgicales en raison de sa taille, son coût réduit et sa capacité à être stérilisé

Skeletal muscle segmentation from MRI dataset using a model-based approach

Magnetic resonance imaging (MRI) and computed tomography scans are used to assess muscle volume, but the manual segmentation, slice by slice, is long and tedious. We proposed an improvement in the deformation of a parametric-specific object method using image processing. The 3D subject-specific geometry was reconstructed based on a few selected number of MRI slices by fast rough contouring using polygons. These polygons were matched to the muscle shape by an optimisation method using an original cost function. Then, parametric-specific object was constructed and deformed. The shape was improved using a loop and the cost function in all MRI slices. The 11 main muscles of the thigh were considered, and the time required to get the shape of all muscles was 21 min, with a volume error inferior to 5% and a point-surface distance error (2RMS) inferior to 5 mm. This method provides a good compromise between segmentation time and an accurate representation of the muscles shape

Responsiveness of the Motor Function Measure in Patients With Spinal Muscular Atrophy

Abstract Objective: To assess the ability of the Motor Function Measure (MFM) to detect changes in the progression of spinal muscular atrophy (SMA). Design: Observational, retrospective, multicenter cohort study. Setting: Seventeen departments of pediatric physical medicine. Participants: Volunteer patients with SMA (NZ112) aged 5.7 to 59 years with no treatment other than physical therapy and nutritional or respiratory assistance. Interventions: Not applicable. Main Outcome Measures: The distributions of the MFM scores (total score and 3 subscores) were analyzed per SMA subtype. The relationships between scores and age were studied. The slopes of score changes (reflecting MFM responsiveness) were estimated in patients with at least 6 months' follow-up and 2 MFMs. Hypothetical sample sizes for specific effect sizes in clinical trial scenarios are given. Results: In 12 patients with SMA type 2 and 19 with SMA type 3 (mean AE SD follow-up, 25.8AE19mo), there was a moderate inverse relationship between age and the MFM total score. Patients with less than 6 months' follow-up showed little score changes. Patients with longer follow-ups showed a slow deterioration (À0.9 points/y for type 2 and À0.6 points/y for type 3). Substantial responsiveness was obtained with the MFM Dimension 2 subscore (proximal and axial motricity) in patients with SMA type 2 (standardized response mean [SRM]Z1.29), and with the MFM Dimension 1 subscore (standing and transfers) in patients with SMA type 3 aged 10 to 15 years (SRMZ.94). Conclusions: If further confirmed by larger studies, these preliminary results on the relative responsiveness of the MFM in SMA will foster its use in monitoring disease progression in patients who participate in clinical trials

Fatal Case of Enterovirus 71 Infection, France, 2007

A fatal case of enterovirus 71 infection with pulmonary edema and rhombencephalitis occurred in Brest, France, in April 2007. The virus was identified as subgenogroup C2. This highly neurotropic enterovirus merits specific surveillance outside the Asia-Pacific region

Disease Severity and Progression in Progressive Supranuclear Palsy and Multiple System Atrophy: Validation of the NNIPPS – PARKINSON PLUS SCALE

BACKGROUND The Natural History and Neuroprotection in Parkinson Plus Syndromes (NNIPPS) study was a large phase III randomized placebo-controlled trial of riluzole in Progressive Supranuclear Palsy (PSP, n = 362) and Multiple System Atrophy (MSA, n = 398). To assess disease severity and progression, we constructed and validated a new clinical rating scale as an ancillary study. METHODS AND FINDINGS Patients were assessed at entry and 6-montly for up to 3 years. Evaluation of the scale's psychometric properties included reliability (n = 116), validity (n = 760), and responsiveness (n = 642). Among the 85 items of the initial scale, factor analysis revealed 83 items contributing to 15 clinically relevant dimensions, including Activity of daily Living/Mobility, Axial bradykinesia, Limb bradykinesia, Rigidity, Oculomotor, Cerebellar, Bulbar/Pseudo-bulbar, Mental, Orthostatic, Urinary, Limb dystonia, Axial dystonia, Pyramidal, Myoclonus and Tremor. All but the Pyramidal dimension demonstrated good internal consistency (Cronbach α ≥ 0.70). Inter-rater reliability was high for the total score (Intra-class coefficient = 0.94) and 9 dimensions (Intra-class coefficient = 0.80-0.93), and moderate (Intra-class coefficient = 0.54-0.77) for 6. Correlations of the total score with other clinical measures of severity were good (rho ≥ 0.70). The total score was significantly and linearly related to survival (p<0.0001). Responsiveness expressed as the Standardized Response Mean was high for the total score slope of change (SRM = 1.10), though higher in PSP (SRM = 1.25) than in MSA (SRM = 1.0), indicating a more rapid progression of PSP. The slope of change was constant with increasing disease severity demonstrating good linearity of the scale throughout disease stages. Although MSA and PSP differed quantitatively on the total score at entry and on rate of progression, the relative contribution of clinical dimensions to overall severity and progression was similar. CONCLUSIONS The NNIPPS-PPS has suitable validity, is reliable and sensitive, and therefore is appropriate for use in clinical studies with PSP or MSA. TRIAL REGISTRATION ClinicalTrials.gov NCT00211224

Multi-instrument multi-scale experimental damage mechanics for fibre reinforced composites

© Published under licence by IOP Publishing Ltd. Reliable investigation of damage in fibre reinforced composites requires concurrent in- and ex-situ application of multiple instruments at different scale: digital image correlation, acoustic emission registration, optical/electron microscopy, C-scan, X-ray imaging and micro-computed tomography. The multi-instrument experimental mechanics allows detailed damage monitoring and inspection