Lpd depletion reveals that SRF specifies radial versus tangential migration of pyramidal neurons

During corticogenesis, pyramidal neurons (~80% of cortical neurons) arise from the ventricular zone, pass through a multipolar stage to become bipolar and attach to radial glia[superscript 1, 2], and then migrate to their proper position within the cortex[superscript 1, 3]. As pyramidal neurons migrate radially, they remain attached to their glial substrate as they pass through the subventricular and intermediate zones, regions rich in tangentially migrating interneurons and axon fibre tracts. We examined the role of lamellipodin (Lpd), a homologue of a key regulator of neuronal migration and polarization in Caenorhabditis elegans, in corticogenesis. Lpd depletion caused bipolar pyramidal neurons to adopt a tangential, rather than radial-glial, migration mode without affecting cell fate. Mechanistically, Lpd depletion reduced the activity of SRF, a transcription factor regulated by changes in the ratio of polymerized to unpolymerized actin. Therefore, Lpd depletion exposes a role for SRF in directing pyramidal neurons to select a radial migration pathway along glia rather than a tangential migration mode.Ruth L. Kirschstein National Research Service Award (grant F32- GM074507)National Institutes of Health (U.S.) (grant # GM068678

Characterization of polycrystalline Cu(In,Ga)Te2 thin films prepared by pulsed laser deposition

Thin films of the chalcopyrite compound CuGaXIn1-XTe2 (0=<X=<1) have been prepared by pulsed laser deposition (PLD) of prereacted material onto glass substrates. The structural and optical properties of these films have been investigated using the techniques of X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), Rutherford back scattering (RBS), transmittance (T), reflectance (R). Electrical characterization was performed using Hall and resistivity measurements, using the Van der Pauw technique at 300 K. The composition of the laser-deposited films was found to closely match that of the target materials and the XRD showed them to be single phase with the chalcopyrite structure and a preferred orientation along the (112) plane. The spectral dependence of the refractive index n and absorption coefficient alpha of the Cu(In,Ga)Te2 thin films were determined using rigorous expressions for transmission and reflection in an air/film/substrate/air multilayer system. The CuGaXIn1-XTe2 films had optical absorption coefficients of order 104 cm-1 and the energy gaps observed in these films increased from 0.96 to 1.32 eV with increasing Ga content

Image-guided delivery of therapeutics to the brain

CNS disorders still prevail to be one of the largest disease areas where current treatment options are limited and there has been growing interest among academia, industry, and research organizations to explore novel options to deliver therapeutics to the brain. Novel strategies encompassing invasive and noninvasive approaches for CNS delivery, to overcome physiological and technical challenges has been the current norm. CNS imaging offers improved diagnosis of disorders and techniques like X-ray computed tomography (CT), single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) have proved to be promising for cerebral imaging. Combinations of functional and structural imaging modalities such as PET/MRI and SPECT/MRI are known to be used for preclinical and clinical imaging. The concept of image-guided targeted delivery of therapeutics to the CNS is seen to be an effective strategy to compliment the current diagnosis regimen with a therapeutic end goal. Combination of nanoparticulate drug delivery with an imaging component has shown initial promise to improve targeting of therapeutics to the CNS

ALICE: Physics Performance Report, Volume II

ALICE is a general-purpose heavy-ion experiment designed to study the physics of strongly interacting matter and the quark-gluon plasma in nucleus-nucleus collisions at the LHC. It currently involves more than 900 physicists and senior engineers, from both the nuclear and high-energy physics sectors, from over 90 institutions in about 30 countries. The ALICE detector is designed to cope with the highest particle multiplicities above those anticipated for Pb-Pb collisions (dN(ch)/dy up to 8000) and it will be operational at the start-up of the LHC. In addition to heavy systems, the ALICE Collaboration will study collisions of lower-mass ions, which are a means of varying the energy density, and protons (both pp and pA), which primarily provide reference data for the nucleus-nucleus collisions. In addition, the pp data will allow for a number of genuine pp physics studies. The detailed design of the different detector systems has been laid down in a number of Technical Design Reports issued between mid-1998 and the end of 2004. The experiment is currently under construction and will be ready for data taking with both proton and heavy-ion beams at the start-up of the LHC. Since the comprehensive information on detector and physics performance was last published in the ALICE Technical Proposal in 1996, the detector, as well as simulation, reconstruction and analysis software have undergone significant development. The Physics Performance Report (PPR) provides an updated and comprehensive summary of the performance of the various ALICE subsystems, including updates to the Technical Design Reports, as appropriate. The PPR is divided into two volumes. Volume I, published in 2004 (CERN/LHCC 2003-049, ALICE Collaboration 2004 J. Phys. G: Nucl. Part. Phys. 30 1517-1763), contains in four chapters a short theoretical overview and an extensive reference list concerning the physics topics of interest to ALICE, the experimental conditions at the LHC, a short summary and update of the subsystem designs, and a description of the offline framework and Monte Carlo event generators. The present volume, Volume II, contains the majority of the information relevant to the physics performance in proton-proton, proton-nucleus, and nucleus-nucleus collisions. Following an introductory overview, Chapter 5 describes the combined detector performance and the event reconstruction procedures, based on detailed simulations of the individual subsystems. Chapter 6 describes the analysis and physics reach for a representative sample of physics observables, from global event characteristics to hard processes