Antidepressant drugs and the response in the placebo group: the real problem lies in our understanding of the issue

In a recent paper, Horder and colleagues (Horder et al., 2010, J Psychopharmacol 25: 1277–1288) have suggested that the mainproblem in the Kirsch analysis is methodological. We argue that the results are similar irrespective of the method used. In our opinion the data suggest that placebo and drug effects are non-additive: antidepressants act independently of depression severity, while the placebo effect is present only in milder cases. While the response in the placebo group is due to unstable ‘noise’ and ‘artefacts’, the medication effect is reliable, valid and stable

From Poincare to affine invariance: How does the Dirac equation generalize?

A generalization of the Dirac equation to the case of affine symmetry, with SL(4,R) replacing SO(1,3), is considered. A detailed analysis of a Dirac-type Poincare-covariant equation for any spin j is carried out, and the related general interlocking scheme fulfilling all physical requirements is established. Embedding of the corresponding Lorentz fields into infinite-component SL(4,R) fermionic fields, the constraints on the SL(4,R) vector-operator generalizing Dirac's gamma matrices, as well as the minimal coupling to (Metric-)Affine gravity are studied. Finally, a symmetry breaking scenario for SA(4,R) is presented which preserves the Poincare symmetry.Comment: 34 pages, LaTeX2e, 8 figures, revised introduction, typos correcte

Inverse Scattering for Gratings and Wave Guides

We consider the problem of unique identification of dielectric coefficients for gratings and sound speeds for wave guides from scattering data. We prove that the "propagating modes" given for all frequencies uniquely determine these coefficients. The gratings may contain conductors as well as dielectrics and the boundaries of the conductors are also determined by the propagating modes.Comment: 12 page

Melanoma-associated adhesion molecule MUC18/MCAM (CD146) and transcriptional regulator Mader in normal human CNS

The proteins MUC18 and Mader have been identified as markers of tumor progression in melanoma cells, MUC18, also known as MCAM (melanoma cell adhesion molecule) and as CD146 (endothelial antigen), is a cell adhesion molecule belonging to the immunoglobulin superfamily, Mader is a transcriptional regulator shown to negatively regulate EGR-1. As it is known that neoplastic cells of neuroectodermal origin frequently express neuron-specific molecules, we studied whether these melanoma-associated antigens are found in normal CNS tissue. We investigated the expression of MUC18/MCAM and Mader in adult human post mortem CNS tissue by immunohistochemistry, immunoblot and two-dimensional gel electrophoresis. Our results show that Mader is preferentially expressed on neurons and glial cells and that the adhesion protein MUC18/MCAM is mainly expressed on vasculature within the CNS. These observations may have important implications for further studies investigating their possible roles in cell adhesion and proliferation control within the CNS

Wetting and particle adsorption in nanoflows

Molecular dynamics simulations are used to study the behavior of closely-fitting spherical and ellipsoidal particles moving through a fluid-filled cylinder at nanometer scales. The particle, the cylinder wall and the fluid solvent are all treated as atomic systems, and special attention is given to the effects of varying the wetting properties of the fluid. Although the modification of the solid-fluid interaction leads to significant changes in the microstructure of the fluid, its transport properties are found to be the same as in bulk. Independently of the shape and relative size of the particle, we find two distinct regimes as a function of the degree of wetting, with a sharp transition between them. In the case of a highly-wetting suspending fluid, the particle moves through the cylinder with an average axial velocity in agreement with that obtained from the solution of the continuum Stokes equations. In contrast, in the case of less-wetting fluids, only the early-time motion of the particle is consistent with continuum dynamics. At later times, the particle is eventually adsorbed onto the wall and subsequently executes an intermittent stick-slip motion.We show that van der Walls forces are the dominant contribution to the particle adsorption phenomenon and that depletion forces are weak enough to allow, in the highly-wetting situation, an initially adsorbed particle to spontaneously desorb

The weak localization for the alloy-type Anderson model on a cubic lattice

We consider alloy type random Schr\"odinger operators on a cubic lattice whose randomness is generated by the sign-indefinite single-site potential. We derive Anderson localization for this class of models in the Lifshitz tails regime, i.e. when the coupling parameter $\lambda$ is small, for the energies $E \le -C \lambda^2$.Comment: 45 pages, 2 figures. To appear in J. Stat. Phy

Spectra of Discrete Schr\"odinger Operators with Primitive Invertible Substitution Potentials

We study the spectral properties of discrete Schr\"odinger operators with potentials given by primitive invertible substitution sequences (or by Sturmian sequences whose rotation angle has an eventually periodic continued fraction expansion, a strictly larger class than primitive invertible substitution sequences). It is known that operators from this family have spectra which are Cantor sets of zero Lebesgue measure. We show that the Hausdorff dimension of this set tends to $1$ as coupling constant $\lambda$ tends to $0$. Moreover, we also show that at small coupling constant, all gaps allowed by the gap labeling theorem are open and furthermore open linearly with respect to $\lambda$. Additionally, we show that, in the small coupling regime, the density of states measure for an operator in this family is exact dimensional. The dimension of the density of states measure is strictly smaller than the Hausdorff dimension of the spectrum and tends to $1$ as $\lambda$ tends to $0$

Intense emission of cluster anions from gold targets under impact of keV/u gold clusters

CAS, BIASPas de résum

Activation dependent clustering of the erbB2 receptor tyrosine kinase detected by scanning near-field optical microscopy

ErbB2 (HER2, Neu), a member of the epidermal growth factor (EGF) receptor tyrosine kinase family, is often overexpressed in breast cancer and other malignancies, ErbB2 homodimerizes but also presents as a common auxiliary subunit of the EGF and heregulin receptors (erbB1 or EGFR; and erbB3-4, respectively), with which it heteroassociates, ErbB2 is generally regarded as an orphan (ligand-less) receptor with a very potent kinase domain activated either via its associated partners or constitutively as a consequence of discrete mutations. It follows that the extent and regulation of its cell surface interactions are of central importance. We have studied the large-scale association pattern of erbB2 in quiescent and activated cells labeled with fluorescent anti-erbB2 monoclonal antibodies using scanning near-field optical microscopy (SNOM), ErbB2 was found to be concentrated in irregular membrane patches with a mean diameter of approx. 0.5 mu m in nonactivated SKBR3 and MDA453 human breast tumor cells. The average number of erbB2 proteins in a single cluster on nonactivated SKBR3 cells was about 10(3). Activation of SKBR3 cells with EGF, heregulin as well as a partially agonistic anti-erbB2 monoclonal antibody led to an increase in the mean cluster diameter to 0.6-0.9 mu m, irrespective of the ligand, The EGF-induced increase in the erbB2 cluster size was inhibited by the EGFR-specific tyrosine kinase inhibitor PD153035, The average size of erbB2 clusters on the erbB2-transfected line of CHO cells (CB2) was similar to that of activated SKBR3 cells, a finding correlated with the increased base-line tyrosine phosphorylation of erbB2 in cells expressing only erbB2, We conclude that an increase in cluster size may constitute a general phenomenon in the activation of erbB2