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Abstract: Analysis of the data collected during the AMMA (African Monsoon Multidisciplinary Analyses) campaign shows that rain storms typical of the African monsoon have multifractal properties, and can be modelled by fractionally integrated multiplicative cascades. The originality of the present study lies in the application of a constraint, which results in the interior only of storms being investigated, such that the multifractal analysis is not affected by the presence of numerous zero values. The model is validated in the time domain by means of disdrometer measurements, and in the spatial domain with co-localized meteorological radar rain maps. The non-conservation parameter obtained in the spatial domain is found to be consistent with the assumption that the rain rate follows a passive scalar-like scaling law up to the scale of storms, including corrections due to fluxes intermittencies. Comparison of the value of this parameter with that obtained in the temporal domain indicates the presence of a space–time anisotropy, which could be explained by turbulent advection. [Copyright &y& Elsevier]

Summary: Nonlinear rain dynamics, due to strong coupling with turbulence, can be described by stochastic scale invariant (such as multifractal) models. In this study, attention is focused on the three-parameter fractionally integrated flux (FIF), based on the universal multifractal (UM) model developed by . Multifractal analysis techniques were applied to experimental radar data measured during the African monsoon multidisciplinary analysis (AMMA) campaign, during the summer of 2006. The non-conservation parameter H, which has often been estimated at 0, was found to be more likely close to 0.4, meaning that rain is not a conserved cascade. Moreover, it is shown that the presence of numerous zero values in the data has an influence, which has until now been underestimated, but should in fact be accounted for. UM parameters are therefore estimated from the full dataset, and then only from maps in which almost all pixels have a non-zero value. Significant differences were found, attributed to on–off intermittency, and their role was checked by means of simulations. Finally, these results are compared with those previously based on time series, and collected by a co-localized disdrometer. The sets of parameters obtained in the spatial and time domains are found to be quite close to each other, contrary to most results published in the literature. This generally reported incoherency is believed to result mainly from the influence of on–off intermittency, whose effects are stronger for time series than for selected radar maps. [Copyright &y& Elsevier]

Multifractal analysis was applied to evidence spatial properties, in particular scaling behaviour, of Sentinel-2 surface reflectances and optical indexes acquired over the Southwest region of France. Considering the significant impact of clouds on the spatial properties of optical products, no study to our knowledge has focused on the multifractal analysis of a series of images. Images with minimal cloud cover were identified for the whole year 2016 based on the MACCS-ATCOR Joint Algorithm (MAJA) cloud and shadow detection process. This allowed us to access the dynamics of the scaling properties of surface reflectances, contributing to demonstrate the potential of multifractals for spatial characterization. Different scaling regimes, separated by significant scale breaks, were evident in these data. Through simulations from the Universal Multifractal model, we could explain the scaling properties and especially the position of scale breaks observed in the images studied by two types of phenomena. First, a transition scale located between hundreds of meters and one kilometre was detected on power spectra, structure functions and statistical moments. This specific scale was related to the average size of the agricultural plots of the studied region, revealing the direct link between the scaling behaviour observed and the physical properties of the surface. Second, an instrumental phenomenon was detected on the power spectra, resulting in a systematic transition scale observed near the resolution of the sensor and revealing the impact of the acquisition system on the high frequencies of optical images. In this research work, theoretical and/or empirical validation arguments were provided as to the origin of the scales detected, contributing to demonstrate the value of multifractals to extract image texture from surface reflectance products. • Particular scale breaks were detected on Sentinel-2/MAJA products. • Time variations in scaling regimes were noticed in series of surface reflectances. • The large-scale break was related to the landscape spatial structure. • The fine-scale break was explained by the effect of the optical acquisition system. [ABSTRACT FROM AUTHOR]

In this study, we identified the expression and the regulation of ADAM members (a disintegrin and metalloprotease) at both gene and protein levels during human osteoclast differentiation and activity. Human peripheral blood monocytes (HPBMC) treated with M-CSF and RANKL were used as an in vitro fusion model. In parallel, we used human osteoclastoma (OCL) tumor as a source of mature osteoclasts, and human osteoblastic cells as a control representing nonfusing and non-resorbing bone cells. RT-PCR using ADAM-specific primers enabled us to identify the expression of ADAM 8, 9, 10, 15, 17, and 28 in both osteoclasts and osteoblasts. Using primers specific for each ADAM 12 isoform (L and S), we observed a strong signal for both forms (ADAM 12L and ADAM 12S) in osteoblastic cells, while only ADAM 12S was detectable in HPBMC-derived osteoclasts and osteoclastoma. Gene regulation was studied using real-time PCR analysis performed during HPBMC differentiation; this showed a progressive increase of ADAM 12 mRNA level from day 1 to 8 of the culture, while at around day 9, ADAM 12 mRNA level decreased 2-fold. We also showed that ADAM 8, ADAM 17, and ADAM 28 decreased according to the stage of HPBMC differentiation or fusion. ADAM 10 was unaltered during cell fusion. However, confocal immunolocalization showed that ADAM 10 protein re-localized from the nuclei and cytoplasm to the plasma membrane during culture and to the ruffled border in resorbing cells. The same re-localization process was observed using an ADAM 12S-specific antibody during HPBMC differentiation. Between days 12 and 14, ADAM 12 co-localized with the F-actin ring, and at day 15, a strong signal was also present in ruffled border or sealing zone area of osteoclasts. Our results describe the expression and regulation of various ADAMs in human bone cells and the selective expression of ADAM 12L in osteoblasts. Our gene regulation and protein localization studies suggest a function for ADAM 10 and ADAM 12S in the formation of osteoclasts from HPBMC and resorption activity. [Copyright &y& Elsevier]

We report the first Raman spectra of individual living and dead cells (MLE-12 line) cultured on bioinert standard poly-L-lysine coated fused silica and on bioactive 45S5 Bioglass [ABSTRACT FROM AUTHOR]

Cell adhesion directly influences cell growth, differentiation and migration as well as morphogenesis, integrity and repair. The extracellular matrix (ECM) elaborated by osteoblast cells constitutes a regulator of the cell adhesion process and then of the related phenomenon. These regulatory effects of ECM are mediated through integrins and some of them are able to bind RGD sequences. The aim of this study was to determine the role of the sequence and the structure of RGD-containing peptides (linear and cyclic) as well as their role in the cell adhesion process. Cell adhesion assays onto ECM proteins coated surfaces were performed using a range of linear and cyclic RGD-containing peptides. We showed a different human osteoprogenitor cell adhesion according to the coating for ECM proteins and for RGD-peptides. Inhibition assays using peptides showed different responses depending on the coated protein. Depending on the amino-acid sequence and the structure of the peptides (cyclic/linear), we observed 100% inhibition of cell adhesion onto vitronectin. These results suggest the importance of sequence, structure and conformation of the peptide, which may play a crucial function in the ligand/receptor interaction and/or in the stability of the interaction. [Copyright &y& Elsevier]

• Fractal and multifractal properties were observed on remotely sensed soil moisture products acquired from SMOS satellite (Soil Moisture and Ocean Salinity), over space scales ranging from the kilometric field scale to the continental scale. • Two scaling regimes were noticed for the soil moisture data disaggregated with DisPATCh algorithm (Disaggregation based on Physical And Theoretical scale Change), with a scaling break observed at about ten kilometers. • Fractality and multifractality were also found on remotely sensed vegetation indices and surface temperature. Soil moisture has a strong impact on climate, hydrology and agronomy at different space scales, from the continent global scale to the local watershed. Passive microwave sensors, like SMOS satellite (Soil Moisture and Ocean Salinity), allow a global study of soil moisture on the entire globe. To have access to kilometric variability, disaggregation algorithms have been developed, such as the Disaggregation based on Physical And Theoretical scale Change (DisPATCh). This method improves the space resolution of SMOS soil moisture from 40 km to 1 km. To do this, it combines coarse-scale (≈40 km) SMOS products with fine-scale (≈1 km) optical/thermal data. Validation studies on specific scales showed the potential of DisPATCh to enhance the spatio-temporal correlation of disaggregated SM with in-situ measurements, under low-vegetated semi-arid regions. Although the efficiency of the method was revealed in these regions, no studies fully explored its statistical behavior over a continuum of space scales. In this paper, we studied and compared the spatial multi-scale statistics of the different input and output datasets involved in DisPATCh downscaling. To do this, we applied spectral and multifractal analysis on the respective products for the region of southeastern Australia, from June to December 2010. Fractal and multifractal properties (in the framework of the Universal Multifractal model) were observed on inputs of DisPATCh (SMOS soil moisture, MODIS vegetation indices and surface temperature), which confirmed and completed some results reported in existing literature. For the output disaggregated soil moisture, two scaling regimes were observed, with a transition scale observed at about ten kilometers. Considering spectral analysis, at large scales (> 10 km), disaggregated soil moisture was found to have the same scaling as the original SMOS soil moisture. On finer scales (< 10 km), a different behavior was noticed, with a higher value of the slope of the power spectrum. The same scale break was detected on statistical moments, showing that both spectral and multifractal properties of DisPATCh soil moisture are characterized by this twofold scaling signature. [ABSTRACT FROM AUTHOR]

Introduction: Non-unions remain a clinical problem and are characterised by the failure to heal after a defined period of time. Current preclinical non-union models apply a wide variety of techniques to diminish intrinsic healing potential deviating from the clinical situation. The aim of this study was to develop and characterise a non-union model in rats using internal plate fixation without the need for additional healing insults, whereby bone healing can be longitudinally assessed using microCT. It was hypothesized that healing/non-unions can be accurately predicted at early time points by microCT. Materials and methods: Female, skeletally mature Fischer F344 rats received a 2 mm or 1 mm femoral osteotomy, stabilized with either a 2 mm thick plate or a 1.25 mm thick plate. Healing was monitored by microCT over 14 weeks and histological analysis at euthanasia. The mechanical environment was characterised using finite element (FE) modelling and biomechanical testing. Results: The majority of animals receiving the 2 mm thick plate displayed poor healing responses in both the 2 mm and 1 mm defect size groups. Bone and cartilage formation were markedly improved using the 1.25 mm thick plate. MicroCT could accurately predict bone forming capacity at early time points (3–4 weeks). Conclusions: The 2 mm thick plating system confers poor healing responses in female Fischer F344 rats, comparable to atrophic non-unions. By reducing plate thickness to increase interfragmentary strain within the defect site healing is improved, leading to borderline healing situations or increased abundance of cartilage tissue present in the defect site with ultimate failure to bridge the defect (hypertrophic non-union). Furthermore, microCT can reliably identify delayed/non-healing animals within 4 weeks, thereby allowing their selective targeting for the testing of novel, clinically relevant treatment strategies in different clinical situations aimed at restoring impaired bone healing. [ABSTRACT FROM AUTHOR]

Both Fourier Transform Infrared (FTIR) and Raman spectroscopy have been applied to the in vitro characterisation of biomaterials, mainly surface reactions leading to the formation of a biologically active hydroxycarbonate apatite (HCA) layer on the sample surface when immersed in simulated body fluids (SBF). The HCA layer indicates the degree of bioactivity of the sample, because it leads to a strong bond between the biomaterial and living tissue. Reflection measurements using FTIR allow quick, non-destructive detection of the HCA layer for solid and powder samples. Due to the low Raman scattering efficiency and low absorption of water in the visible-near infrared region, Raman micro-spectroscopy was successfully used for the in situ characterisation of 20 and 40 μm diameter 45S5 Bioglass [ABSTRACT FROM AUTHOR]

Purpose: Platelet-rich plasma (PRP) contains growth factors and creates a 3D structure upon clotting; PRP or platelet lysate (PL) might be considered for annulus fibrosus (AF) repair. Methods: Bovine AF cells were cultured with 25 % PRP, 50 % PRP, 25 % PL, 50 % PL, or 10 % FBS. After 2 and 4 days, DNA, glycosaminoglycan (GAG), and mRNA levels were analyzed. Histology was performed after injection of PRP into an AF defect in a whole disc ex vivo. Results: By day 4, significant increases in DNA content were observed in all treatment groups. All groups also showed elevated GAG synthesis, with highest amounts at 50 % PL. Collagen I and II expression was similar between groups; aggrecan, decorin, and versican expression was highest at 25 % PL. Injection of PRP into the AF defect resulted in an increased matrix synthesis. Conclusions: Platelet-rich preparations increased the matrix production and cell number and may therefore be considered to promote AF repair. [ABSTRACT FROM AUTHOR]