ABJM Baryon Stability and Myers effect

We consider magnetically charged baryon vertex like configurations in AdS^4 X CP^3 with a reduced number of quarks l. We show that these configurations are solutions to the classical equations of motion and are stable beyond a critical value of l. Given that the magnetic flux dissolves D0-brane charge it is possible to give a microscopical description in terms of D0-branes expanding into fuzzy CP^n spaces by Myers dielectric effect. Using this description we are able to explore the region of finite 't Hooft coupling.Comment: 29 pages, Latex; minor changes; version to appear in JHE

Cytogenetic and Molecular Predictors of Outcome in Acute Lymphocytic Leukemia: Recent Developments

During the last decade a tremendous technologic progress based on genome-wide profiling of genetic aberrations, structural DNA alterations, and sequence variations has allowed a better understanding of the molecular basis of pediatric and adult B/T- acute lymphoblastic leukemia (ALL), contributing to a better recognition of the biological heterogeneity of ALL and to a more precise definition of risk factors. Importantly, these advances identified novel potential targets for therapeutic intervention. This review will be focused on the cytogenetic/molecular advances in pediatric and adult ALL based on recently published articles

Identification and genomic location of a reniform nematode (Rotylenchulus reniformis) resistance locus (Renari) introgressed from Gossypium aridum into upland cotton (G. hirsutum)

In this association mapping study, a tri-species hybrid, [Gossypium arboreum × (G. hirsutum × G. aridum)2], was crossed with MD51ne (G. hirsutum) and progeny from the cross were used to identify and map SSR markers associated with reniform nematode (Rotylenchulus reniformis) resistance. Seventy-six progeny (the 50 most resistant and 26 most susceptible) plants were genotyped with 104 markers. Twenty-five markers were associated with a resistance locus that we designated Renari and two markers, BNL3279_132 and BNL2662_090, mapped within 1 cM of Renari. Because the SSR fragments associated with resistance were found in G. aridum and the bridging line G 371, G. aridum is the likely source of this resistance. The resistance is simply inherited, possibly controlled by a single dominant gene. The markers identified in this project are a valuable resource to breeders and geneticists in the quest to produce cotton cultivars with a high level of resistance to reniform nematode

Significant variation in transformation frequency in Streptococcus pneumoniae

The naturally transformable bacterium Streptococcus pneumoniae is able to take up extracellular DNA and incorporate it into its genome. Maintaining natural transformation within a species requires that the benefits of transformation outweigh its costs. Although much is known about the distribution of natural transformation among bacterial species, little is known about the degree to which transformation frequencies vary within species. Here we find that there is significant variation in transformation frequency between strains of Streptococcus pneumoniae isolated from asymptomatic carriage, and that this variation is not concordant with isolate genetic relatedness. Polymorphism in the signalling system regulating competence is also not causally related to differences in transformation frequency, although this polymorphism does influence the degree of genetic admixture experienced by bacterial strains. These data suggest that bacteria can evolve new transformation frequencies over short evolutionary timescales. This facility may permit cells to balance the potential costs and benefits of transformation by regulating transformation frequency in response to environmental conditions

Modular reorganization of the global network of gene regulatory interactions during perinatal human brain development.

BACKGROUND During early development of the nervous system, gene expression patterns are known to vary widely depending on the specific developmental trajectories of different structures. Observable changes in gene expression profiles throughout development are determined by an underlying network of precise regulatory interactions between individual genes. Elucidating the organizing principles that shape this gene regulatory network is one of the central goals of developmental biology. Whether the developmental programme is the result of a dynamic driven by a fixed architecture of regulatory interactions, or alternatively, the result of waves of regulatory reorganization is not known. RESULTS Here we contrast these two alternative models by examining existing expression data derived from the developing human brain in prenatal and postnatal stages. We reveal a sharp change in gene expression profiles at birth across brain areas. This sharp division between foetal and postnatal profiles is not the result of pronounced changes in level of expression of existing gene networks. Instead we demonstrate that the perinatal transition is marked by the widespread regulatory rearrangement within and across existing gene clusters, leading to the emergence of new functional groups. This rearrangement is itself organized into discrete blocks of genes, each targeted by a distinct set of transcriptional regulators and associated to specific biological functions. CONCLUSIONS Our results provide evidence of an acute modular reorganization of the regulatory architecture of the brain transcriptome occurring at birth, reflecting the reassembly of new functional associations required for the normal transition from prenatal to postnatal brain development

Loss of the interferon-γ-inducible regulatory immunity-related GTPase (IRG), Irgm1, causes activation of effector IRG proteins on lysosomes, damaging lysosomal function and predicting the dramatic susceptibility of Irgm1-deficient mice to infection

The interferon-γ (IFN-γ)-inducible immunity-related GTPase (IRG), Irgm1, plays an essential role in restraining activation of the IRG pathogen resistance system. However, the loss of Irgm1 in mice also causes a dramatic but unexplained susceptibility phenotype upon infection with a variety of pathogens, including many not normally controlled by the IRG system. This phenotype is associated with lymphopenia, hemopoietic collapse, and death of the mouse.Deutscher Akademischer Austausch Dienst (DAAD); International Graduate School in Development Health and Disease (IGS-DHD); Deutsche For-schungsgemeinschaft (SFBs 635, 670, 680); Max-Planck-Gesellschaft (Max Planck Fellowship)

Methylation QTLs in the developing brain and their enrichment in schizophrenia risk loci

We characterized DNA methylation quantitative trait loci (mQTLs) in a large collection (n = 166) of human fetal brain samples spanning 56-166 d post-conception, identifying >16,000 fetal brain mQTLs. Fetal brain mQTLs were primarily cis-acting, enriched in regulatory chromatin domains and transcription factor binding sites, and showed substantial overlap with genetic variants that were also associated with gene expression in the brain. Using tissue from three distinct regions of the adult brain (prefrontal cortex, striatum and cerebellum), we found that most fetal brain mQTLs were developmentally stable, although a subset was characterized by fetal-specific effects. Fetal brain mQTLs were enriched amongst risk loci identified in a recent large-scale genome-wide association study (GWAS) of schizophrenia, a severe psychiatric disorder with a hypothesized neurodevelopmental component. Finally, we found that mQTLs can be used to refine GWAS loci through the identification of discrete sites of variable fetal brain methylation associated with schizophrenia risk variants

Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV

Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at $\sqrt{s_{_{\rm NN}}}$ = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in $|\eta|<0.8$ and $0.3 < p_T < 20$ GeV/$c$ are compared to the expectation in pp collisions at the same $\sqrt{s_{\rm NN}}$, scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor $R_{\rm AA}$. The result indicates only weak medium effects ($R_{\rm AA} \approx$ 0.7) in peripheral collisions. In central collisions, $R_{\rm AA}$ reaches a minimum of about 0.14 at $p_{\rm T}=6$-7GeV/$c$ and increases significantly at larger $p_{\rm T}$. The measured suppression of high-$p_{\rm T}$ particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98

Two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/388