GM1 Ganglioside Promotes Osteogenic Differentiation of Human Tendon Stem Cells

Gangliosides, the sialic acid-conjugated glycosphingolipids present in the lipid rafts, have been recognized as important regulators of cell proliferation, migration, and apoptosis. Due to their peculiar localization in the cell membrane, they modulate the activity of several key cell receptors, and increasing evidence supports their involvement also in stem cell differentiation. In this context, herein we report the role played by the ganglioside GM1 in the osteogenic differentiation of human tendon stem cells ( hTSCs). In particular, we found an increase of GM1 levels during osteogenesis that is instrumental for driving the process. In fact, supplementation of the ganglioside in the medium significantly increased the osteogenic differentiation capability of hTSCs. Mechanistically, we found that GM1 supplementation caused a reduction in the phosphorylation of the platelet-derived growth factor receptor-ss ( PDGFR-ss), which is a known inhibitor of osteogenic commitment. These results were further corroborated by the observation that GM1 supplementation was able to revert the inhibitory effects on osteogenesis when the process was inhibited with exogenous PDGF

Prediction of 305-day lactation production of Italian dairy cattle breeds

Projection factors for 305-day for milk fat and protein yield were calculated for the Italian dairy cattle breeds. Different multiplicative coefficients were calculated for each breed, for first, second, and later parities, and for two different seasons. Cumulative and last sample production are used in extending lactations to 305-day. In order to validate the method of prediction, lactations were projected and compared to effective productions. Difference in means and standard deviations between projected and effective 305 productions, and correlation for different classes of lactation length were used as comparison criteria. Where possible data sets used in validation step were different from the data sets used to estimate extension factors. The results indicate an absence of a systematic underestimation or overestimation in predicting 305-day lactations depending from length of partial lactation. A small difference was observed in coefficients calculated for second parity and later parity cows, while coefficients for first lactation records were larger. The method presented will be implemented soon for the routine computation of 305-day lactations in Italy

On the application of the Boltzmann equation to the simulation of fluid structure interaction in MEMS

A three-dimensional quasi-static Stokes model, with a correction based on the kinetic theory of rarefied gas, is used to evaluate the damping forces exerted by gas flows on the moving surfaces of micromechanical structures in a wide range of pressures. Numerical results are compared with the experimental data collected on a silicon biaxial accelerometer in the continuum and transitional flow regimes. Furthermore, rarefied gas flows in ultra-thin film slider bearings are studied through a generalized Reynolds equation based on the linearized Boltzmann equation which holds for arbitrary Knudsen numbers. Since the generalized Reynolds equation is a flow rate-based model and is obtained by calculating the fundamental flows in the lubrication film (i.e., the Poiseuille and Couette flows), the plane Poiseuille-Couette flow problem between parallel plates has been preliminarly investigated. General boundary conditions of Maxwell's type have been considered by allowing for bounding surfaces with different physical properties