Outer core density heterogeneity and the discrepancy between PKP and PcP travel time observations

We derive 3-D maps of the Earth’s mantle, CMB and outer core by means of least squares tomographic inversions. The data set includes compressional wave travel time measurements associated with the phases P, PcP, PKPbc, PKPdf, all based on the bulletins of the International Seismological Centre (1964-1995), after source relocation by Antolik et al. [2001]. Maps of the CMB derived independently from only core-reflected (PcP) or only core-refracted (PKP) phases are not well correlated. We study the radial coherence of whole-Earth tomographic images, to investigate potential trade-offs between CMB undulations and velocity anomalies in the mantle and/or outer core. We find that imaged lateral heterogeneities in the outer core are correlated with the topography of the CMB. This, together with the studies of Wahr and De Vries [1989] and Piersanti et al. [2001], suggests that the core anomalies might not be entirely fictitious

TENOGENIC DIFFERENTIATION PROTOCOL IN XENOGENIC-FREE MEDIA ENHANCES TENDON-RELATED MARKER EXPRESSION IN ADIPOSE-DERIVED STEM CELLS

Tendon injuries are common and current therapies often are unsuccessful. Cell-based therapy using mesenchymal stem cells (MSCs) seems to be the most promising approach to heal tendon. Moreover, providing safe and regulated cell therapy products to patients requires adherence to good manufacturing practices (GMP). Adipose-derived stem cells (n=4) were cultured in 6-well plates coated with type-I collagen in a chemically defined serum-free medium (SF) or a xenogenic-free human pooled platelet lysate medium (hPL). At passage 4, ASCs were induced to tendon lineage for 14 days using 100ng/ml CTGF, 10ng/ml TGFβ3, 50ng/ml BMP12 and 50µg/ml ascorbic acid in the SF (SF-TENO) or in the hPL (hPL-TENO) medium. Cells cultured without any supplements are used as control. Morphological appearance, cell viability and FACS were performed in undifferentiated cells to evaluate the xenogenic-free culture conditions; the gene and protein expression were performed by RT-PCR and immunofluorescence to evaluate to expression of stem cell- and tendon-related markers upon cell differentiation. SF-CTRL and hPL-CTRL showed similar viability and MSC's surface proteins and expressed the stemness markers NANOG, OCT4 and Ki67. Moreover, both SF-TENO and hPL-TENO expressed significant higher levels of SCX, COL1A1, COL3A1, COMP, MMP3 and MMP13 genes already at 3d (p<0.05) respect to CTRLs. Scleraxis and collagen were also detected in both SF-TENO and hPL-TENO at protein level in higher amount than CTRLs. In conclusion, ASCs exposed to CTGF, BMP12, TGFb3 and AA in both serum and xenogenic-free media possess similar tenogenic differentiation ability moving forward the GMP-compliant approaches for the clinical use of ASCs

Fiber suspension investigation in a backward-facing step by PIV

A dilute suspension (volume fraction 0.05%) of rod-like particles in a turbulent backward-facing step flow at Reynolds number ReH=14900, is investigated by means of Particle Image Velocimetry. Two-way interactions between fluid and dispersed phase are analyzed by exploiting the high spatial resolution of the acquisitions. Mutual interactions between phases can be investigated by considering flow turbulence modulations and phenomena related to preferential concentration and orientation of fibers. Slight turbulence enhancement is reported in the laden flow and concentration data show a moderate tendency of fibers to accumulate at the channel centreline. Orientation data display a strong preferential orientation of fibers. Local fiber orientation is correlated to the direction of maximum shear showing a high level of correlation also in the flow regions featuring strong gradients

Outer core density heterogeneity and the discrepancy between PKP and PcP travel time observations

We derive 3-D maps of the Earth’s mantle, CMB and outer core by means of least squares tomographic inversions. The data set includes compressional wave travel time measurements associated with the phases P, PcP, PKPbc, PKPdf, all based on the bulletins of the International Seismological Centre (1964-1995), after source relocation by Antolik et al. [2001]. Maps of the CMB derived independently from only core-reflected (PcP) or only core-refracted (PKP) phases are not well correlated. We study the radial coherence of whole-Earth tomographic images, to investigate potential trade-offs between CMB undulations and velocity anomalies in the mantle and/or outer core. We find that imaged lateral heterogeneities in the outer core are correlated with the topography of the CMB. This, together with the studies of Wahr and De Vries [1989] and Piersanti et al. [2001], suggests that the core anomalies might not be entirely fictitious

On the mystery of the missing pie in graphene

We investigate in some detail the structure of the electromagnetic current density for the pseudo-relativistic massless spinor effective model for graphene. It is shown that the pseudo-relativistic massless Dirac field theory in {\em 2+1} space-time dimensions and in the presence of a constant homogeneous electric field actually leads to the measured current density and to the minimum quantum conductivity.Comment: 10 pages, no figures, substantial changes and added reference

The quantum Hall effect in graphene samples and the relativistic Dirac effective action

We study the Euclidean effective action per unit area and the charge density for a Dirac field in a two--dimensional spatial region, in the presence of a uniform magnetic field perpendicular to the 2D--plane, at finite temperature and density. In the limit of zero temperature we reproduce, after performing an adequate Lorentz boost, the Hall conductivity measured for different kinds of graphene samples, depending upon the phase choice in the fermionic determinant.Comment: Conclusions extended. References added. 9 pages. 1 figur

Multi-channel communication vs. adaptive routing for reliable communication in WSNs

Interference and link dynamics constitute great concerns for stability and performance of protocols in WSNs. In this paper we evaluate the impact of channel hopping and adaptive routing on delay and reliability focusing on delay critical applications