Mouse adipose-derived stem cells undergo multilineage differentiation in vitro but primarily osteogenic and chondrogenic differentiation in vivo

Human, rat, and mouse studies have demonstrated the existence of a population of adipose-derived adult stem (ADAS) cells that can undergo multilineage differentiation in vitro. However, it remains unclear whether these cells maintain their multilineage potential in vivo. The aim of this study was to examine the in vitro and in vivo characteristics and behavior of a potential population of murine ADAS (muADAS) cells isolated from the visceral fat of the abdominal cavity of C57BL/10J mice. We used flow cytometry to examine the cells' expression of CD29, CD31, CD45, CD34, CD44, CD144, CD146, Flk1, and Sca-1. The isolated cell population was CD45 negative, which precludes contamination by hematopoietic cells, but was partially positive for Sca-1 and CD34: 2 stem-cell markers. After induction in conditioned medium, the muADAS cells gained the ability to undergo adipogenic, osteogenic, chondrogenic, myogenic, and hematopoietic differentiation in vitro. The muADAS cells readily differentiated to form bone and cartilage in vivo for up to 24 weeks, but their ability to regenerate muscle or reconstitute bone marrow was found to be limited. © Mary Ann Liebert, Inc

Ice and Dust in the Quiescent Medium of Isolated Dense Cores

The relation between ices in the envelopes and disks surrounding YSOs and those in the quiescent interstellar medium is investigated. For a sample of 31 stars behind isolated dense cores, ground-based and Spitzer spectra and photometry in the 1-25 um wavelength range are combined. The baseline for the broad and overlapping ice features is modeled, using calculated spectra of giants, H2O ice and silicates. The adopted extinction curve is derived empirically. Its high resolution allows for the separation of continuum and feature extinction. The extinction between 13-25 um is ~50% relative to that at 2.2 um. The strengths of the 6.0 and 6.85 um absorption bands are in line with those of YSOs. Thus, their carriers, which, besides H2O and CH3OH, may include NH4+, HCOOH, H2CO and NH3, are readily formed in the dense core phase, before stars form. The 3.53 um C-H stretching mode of solid CH3OH was discovered. The CH3OH/H2O abundance ratios of 5-12% are larger than upper limits in the Taurus molecular cloud. The initial ice composition, before star formation occurs, therefore depends on the environment. Signs of thermal and energetic processing that were found toward some YSOs are absent in the ices toward background stars. Finally, the peak optical depth of the 9.7 um band of silicates relative to the continuum extinction at 2.2 um is significantly shallower than in the diffuse interstellar medium. This extends the results of Chiar et al. (2007) to a larger sample and higher extinctions.Comment: Accepted for publication in The Astrophysical Journa

Conditional symmetries and Riemann invariants for inhomogeneous hydrodynamic-type systems

A new approach to the solution of quasilinear nonelliptic first-order systems of inhomogeneous PDEs in many dimensions is presented. It is based on a version of the conditional symmetry and Riemann invariant methods. We discuss in detail the necessary and sufficient conditions for the existence of rank-2 and rank-3 solutions expressible in terms of Riemann invariants. We perform the analysis using the Cayley-Hamilton theorem for a certain algebraic system associated with the initial system. The problem of finding such solutions has been reduced to expanding a set of trace conditions on wave vectors and their profiles which are expressible in terms of Riemann invariants. A couple of theorems useful for the construction of such solutions are given. These theoretical considerations are illustrated by the example of inhomogeneous equations of fluid dynamics which describe motion of an ideal fluid subjected to gravitational and Coriolis forces. Several new rank-2 solutions are obtained. Some physical interpretation of these results is given.Comment: 19 page

Test of Quantum Action for Inverse Square Potential

We present a numerical study of the quantum action previously introduced as a parametrisation of Q.M. transition amplitudes. We address the questions: Is the quantum action possibly an exact parametrisation in the whole range of transition times ($0 < T < \infty$)? Is the presence of potential terms beyond those occuring in the classical potential required? What is the error of the parametrisation estimated from the numerical fit? How about convergence and stability of the fitting method (dependence on grid points, resolution, initial conditions, internal precision etc.)? Further we compare two methods of numerical determination of the quantum action: (i) global fit of the Q.M. transition amplitudes and (ii) flow equation. As model we consider the inverse square potential, for which the Q.M. transition amplitudes are analytically known. We find that the relative error of the parametrisation starts from zero at T=0 increases to about $10^{-3}$ at $T=1/E_{gr}$ and then decreases to zero when $T \to \infty$. Second, we observe stability of the quantum action under variation of the control parameters. Finally, the flow equation method works well in the regime of large $T$ giving stable results under variation of initial data and consistent with the global fit method.Comment: Text (LaTeX), Figures(ps

Isolation of Myogenic Stem Cells from Cultures of Cryopreserved Human Skeletal Muscle

We demonstrate that subpopulations of adult human skeletal muscle-derived stem cells, myogenic endothelial cells (MECs), and perivascular stem cells (PSCs) can be simultaneously purified by fluorescence-activated cell sorting (FACS) from cryopreserved human primary skeletal muscle cell cultures (cryo-hPSMCs). For FACS isolation, we utilized a combination of cell lineage markers: the myogenic cell marker CD56, the endothelial cell marker UEA-1 receptor (UEA-1R), and the perivascular cell marker CD146. MECs expressing all three cell lineage markers (CD56+UEA-1R+CD146+/CD45+) and PSCs expressing only CD146 (CD146+/CD45+CD56+UEA-1R+) were isolated by FACS. To evaluate their myogenic capacities, the sorted cells, with and without expansion in culture, were transplanted into the cardiotoxin-injured skeletal muscles of immunodeficient mice. The purified MECs exhibited the highest regenerative capacity in the injured mouse muscles among all cell fractions tested, while PSCs remained superior to myoblasts and the unpurified primary skeletal muscle cells. Our findings show that both MECs and PSCs retain their high myogenic potentials after in vitro expansion, cryopreservation, and FACS sorting. The current study demonstrates that myogenic stem cells are prospectively isolatable from long-term cryopreserved primary skeletal muscle cell cultures. We emphasize the potential application of this new approach to extract therapeutic stem cells from human muscle cells cryogenically banked for clinical purposes. © 2012 Cognizant Comm. Corp

Entanglement and squeezing in a two-mode system: theory and experiment

We report on the generation of non separable beams produced via the interaction of a linearly polarized beam with a cloud of cold cesium atoms placed in an optical cavity. We convert the squeezing of the two linear polarization modes into quadrature entanglement and show how to find out the best entanglement generated in a two-mode system using the inseparability criterion for continuous variable [Duan et al., Phys. Rev. Lett. 84, 2722 (2000)]. We verify this method experimentally with a direct measurement of the inseparability using two homodyne detections. We then map this entanglement into a polarization basis and achieve polarization entanglement.Comment: submitted to J. Opt. B for a Special Issue on Foundations of Quantum Optic

VLA 3.5 cm continuum sources in the Serpens cloud core

We present VLA 3.5 cm continuum observations of the Serpens cloud core. 22 radio continuum sources are detected. 16 out of the 22 cm sources are suggested to be associated with young stellar objects (Class 0, Class I, flat-spectrum, and Class II) of the young Serpens cluster. The rest of the VLA sources plausibly are background objects. Most of the Serpens cm sources likely represent thermal radio jets; on the other hand, the radio continuum emission of some sources could be due to a gyrosynchroton mechanism arising from coronally active young stars. The Serpens VLA sources are spatially distributed into two groups; one of them located towards the NW clump of the Serpens core, where only Class 0 and Class I protostars are found to present cm emission, and a second group located towards the SE clump, where radio continuum sources are associated with objects in evolutionary classes from Class 0 to Class II. This subgrouping is similar to that found in the near IR, mid-IR and mm wavelength regimes.Comment: 2 figures, accepted by Astronomical journa