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Sample records for glycosphingolipid-rich microdomains imaged

  1. Dynamic partitioning of a glycosyl-phosphatidylinositol-anchored protein in glycosphingolipid-rich microdomains imaged by single-quantum dot tracking.

    Science.gov (United States)

    Pinaud, Fabien; Michalet, Xavier; Iyer, Gopal; Margeat, Emmanuel; Moore, Hsiao-Ping; Weiss, Shimon

    2009-06-01

    Recent experimental developments have led to a revision of the classical fluid mosaic model proposed by Singer and Nicholson more than 35 years ago. In particular, it is now well established that lipids and proteins diffuse heterogeneously in cell plasma membranes. Their complex motion patterns reflect the dynamic structure and composition of the membrane itself, as well as the presence of the underlying cytoskeleton scaffold and that of the extracellular matrix. How the structural organization of plasma membranes influences the diffusion of individual proteins remains a challenging, yet central, question for cell signaling and its regulation. Here we have developed a raft-associated glycosyl-phosphatidyl-inositol-anchored avidin test probe (Av-GPI), whose diffusion patterns indirectly report on the structure and dynamics of putative raft microdomains in the membrane of HeLa cells. Labeling with quantum dots (qdots) allowed high-resolution and long-term tracking of individual Av-GPI and the classification of their various diffusive behaviors. Using dual-color total internal reflection fluorescence (TIRF) microscopy, we studied the correlation between the diffusion of individual Av-GPI and the location of glycosphingolipid GM1-rich microdomains and caveolae. We show that Av-GPI exhibit a fast and a slow diffusion regime in different membrane regions, and that slowing down of their diffusion is correlated with entry in GM1-rich microdomains located in close proximity to, but distinct, from caveolae. We further show that Av-GPI dynamically partition in and out of these microdomains in a cholesterol-dependent manner. Our results provide direct evidence that cholesterol-/sphingolipid-rich microdomains can compartmentalize the diffusion of GPI-anchored proteins in living cells and that the dynamic partitioning raft model appropriately describes the diffusive behavior of some raft-associated proteins across the plasma membrane.

  2. Proteomic identification of proteins translocated to membrane microdomains upon treatment of fibroblasts with the glycosphingolipid, C8-beta-D-lactosylceramide.

    Science.gov (United States)

    Kim, Seong-Youl; Wang, Teng-ke; Singh, Raman Deep; Wheatley, Christine L; Marks, David L; Pagano, Richard E

    2009-09-01

    Plasma membrane (PM) microdomains, including caveolae and other cholesterol-enriched subcompartments, are involved in the regulation of many cellular processes, including endocytosis, attachment and signaling. We recently reported that brief incubation of human skin fibroblasts with the synthetic glycosphingolipid, D-erythro-octanoyl-lactosylceramide (C8-D-e-LacCer), stimulates endocytosis via caveolae and induces the appearance of micron-size microdomains on the PM. To further understand the effects of C8-D-e-LacCer treatment on PM microdomains, we used a detergent-free method to isolate microdomain-enriched membranes from fibroblasts treated +/-C8-D-e-LacCer, and performed 2-DE and mass spectrophotometry to identify proteins that were altered in their distribution in microdomains. Several proteins were identified in the microdomain-enriched fractions, including lipid transfer proteins and proteins related to the functions of small GTPases. One protein, Rho-associated protein kinase 2 (ROCK2), was verified by Western blotting to occur in microdomain fractions and to increase in these fractions after D-e-LacCer treatment. Immunofluorescence revealed that ROCK2 exhibited an increased localization at or near the PM in C8-D-e-LacCer-treated cells. In contrast, ROCK2 distribution in microdomains was decreased by treatment of cells with C8-L-threo-lactosylceramide, a glycosphingolipid with non-natural stereochemistry. This study identifies new microdomain-associated proteins and provides evidence that microdomains play a role in the regulation of the Rho/ROCK signaling pathway.

  3. Glycosphingolipides et fusion virus-cellule : données actuelles montrant le rôle des micro-domaines membranaires dans le cycle d’infection du VIH-1

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    Hammache Djilali

    2000-09-01

    Full Text Available Depuis plusieurs années, nous étudions les mécanismes moléculaires responsables de la fusion du virus de l’immunodéficience humaine (VIH avec la membrane plasmique des cellules cibles. Ces travaux ont permis de préciser le rôle essentiel joué par les micro-domaines de glycosphingolipides au cours de la fusion virus-cellule. En particulier, nous avons pu reconstituer un complexe de fusion fonctionnel faisant intervenir les différents partenaires moléculaires de la fusion : un micro-domaine de glycosphingolipide se présentant sous la forme d’un film monomoléculaire à l’interface eau-air, le récepteur CD4 et la glycoprotéine externe de l’enveloppe du virus, la gp120. La dynamique des interactions moléculaires dans ce complexe de fusion a pu être mesurée à l’aide d’un micro-tensiomètre. Ce système expérimental pourrait permettre d’évaluer l’activité d’inhibiteurs de fusion tels que des analogues synthétiques de glycosphingolipides.

  4. Detection of cholesterol-rich microdomains in the inner leaflet of the plasma membrane

    International Nuclear Information System (INIS)

    Hayashi, Masami; Shimada, Yukiko; Inomata, Mitsushi; Ohno-Iwashita, Yoshiko

    2006-01-01

    The C-terminal domain (D4) of perfringolysin O binds selectively to cholesterol in cholesterol-rich microdomains. To address the issue of whether cholesterol-rich microdomains exist in the inner leaflet of the plasma membrane, we expressed D4 as a fusion protein with EGFP in MEF cells. More than half of the EGFP-D4 expressed in stable cell clones was bound to membranes in raft fractions. Depletion of membrane cholesterol with β-cyclodextrin reduced the amount of EGFP-D4 localized in raft fractions, confirming EGFP-D4 binding to cholesterol-rich microdomains. Subfractionation of the raft fractions showed most of the EGFP-D4 bound to the plasma membrane rather than to intracellular membranes. Taken together, these results strongly suggest the existence of cholesterol-rich microdomains in the inner leaflet of the plasma membrane

  5. The role of membrane microdomains in transmembrane signaling through the epithelial glycoprotein Gp140/CDCP1

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    Alvares, Stacy M.; Dunn, Clarence A.; Brown, Tod A.; Wayner, Elizabeth E.; Carter, William G.

    2008-01-01

    Cell adhesion to the extracellular matrix (ECM) via integrin adhesion receptors initiates signaling cascades leading to changes in cell behavior. While integrin clustering is necessary to initiate cell attachment to the matrix, additional membrane components are necessary to mediate the transmembrane signals and the cell adhesion response that alter downstream cell behavior. Many of these signaling components reside in glycosphingolipid-rich and cholesterol-rich membrane domains such as Tetraspanin Enriched Microdomains (TEMs)/Glycosynapse 3 and Detergent-Resistant Microdomains (DRMs), also known as lipid rafts. In the following article, we will review examples of how components in these membrane microdomains modulate integrin adhesion after initial attachment to the ECM. Additionally, we will present data on a novel adhesion-responsive transmembrane glycoprotein Gp140/CUB Domain Containing Protein 1, which clusters in epithelial cell-cell contacts. Gp140 can then be phosphorylated by Src Family Kinases at tyrosine 734 in response to outside-in signals- possibly through interactions involving the extracellular CUB domains. Data presented here suggests that outside-in signals through Gp140 in cell-cell contacts assemble membrane clusters that associate with membrane microdomains to recruit and activate SFKs. Active SFKs then mediate phosphorylation of Gp140, SFK and PKCδ with Gp140 acting as a transmembrane scaffold for these kinases. We propose that the clustering of Gp140 and signaling components in membrane microdomains in cell-cell contacts contributes to changes in cell behavior. PMID:18269919

  6. Lipid rafts exist as stable cholesterol-independent microdomains in the brush border membrane of enterocytes

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Immerdal, Lissi; Thorsen, Evy

    2001-01-01

    Glycosphingolipid/cholesterol-rich membranes ("rafts")can be isolated from many types of cells, but their existence as stable microdomains in the cell membrane has been elusive. Addressing this problem, we studied the distribution of galectin-4, a raft marker, and lactase, a protein excluded from...... rafts, on microvillar vesicles from the enterocyte brush border membrane. Magnetic beads coated with either anti-galectin-4 or anti-lactase antibodies were used for immunoisolation of vesicles followed by double immunogold labeling of the two proteins. A morphometric analysis revealed subpopulations...... of raft-rich and raft-poor vesicles by the following criteria: 1) the lactase/galectin-4 labeling ratio/vesicle captured by the anti-lactase beads was significantly higher (p

  7. GSL-enriched membrane microdomains in innate immune responses.

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    Nakayama, Hitoshi; Ogawa, Hideoki; Takamori, Kenji; Iwabuchi, Kazuhisa

    2013-06-01

    Many pathogens target glycosphingolipids (GSLs), which, together with cholesterol, GPI-anchored proteins, and various signaling molecules, cluster on host cell membranes to form GSL-enriched membrane microdomains (lipid rafts). These GSL-enriched membrane microdomains may therefore be involved in host-pathogen interactions. Innate immune responses are triggered by the association of pathogens with phagocytes, such as neutrophils, macrophages and dendritic cells. Phagocytes express a diverse array of pattern-recognition receptors (PRRs), which sense invading microorganisms and trigger pathogen-specific signaling. PRRs can recognize highly conserved pathogen-associated molecular patterns expressed on microorganisms. The GSL lactosylceramide (LacCer, CDw17), which binds to various microorganisms, including Candida albicans, is expressed predominantly on the plasma membranes of human mature neutrophils and forms membrane microdomains together with the Src family tyrosine kinase Lyn. These LacCer-enriched membrane microdomains can mediate superoxide generation, migration, and phagocytosis, indicating that LacCer functions as a PRR in innate immunity. Moreover, the interactions of GSL-enriched membrane microdomains with membrane proteins, such as growth factor receptors, are important in mediating the physiological properties of these proteins. Similarly, we recently found that interactions between LacCer-enriched membrane microdomains and CD11b/CD18 (Mac-1, CR3, or αMβ2-integrin) are significant for neutrophil phagocytosis of non-opsonized microorganisms. This review describes the functional role of LacCer-enriched membrane microdomains and their interactions with CD11b/CD18.

  8. Caveolae/lipid rafts in fibroblast-like synoviocytes: ectopeptidase-rich membrane microdomains

    DEFF Research Database (Denmark)

    Riemann, D; Hansen, Gert Helge; Niels-Christiansen, L

    2001-01-01

    in the regulation of intra-articular levels of neuropeptides and chemotactic mediators as well as in adhesion and cell-cell interactions. Here, we report these peptidases in synoviocytes to be localized predominantly in glycolipid- and cholesterol-rich membrane microdomains known as 'rafts'. At the ultrastructural...... from about 60 to 160 nm. Cholesterol depletion of synoviocytes by methyl-beta-cyclodextrin disrupted >90% of the caveolae and reduced the raft localization of aminopeptidase N/CD13 without affecting Ala-p-nitroanilide-cleaving activity of confluent cell cultures. In co-culture experiments with T......-lymphocytes, cholesterol depletion of synoviocytes greatly reduced their capability to induce an early lymphocytic expression of aminopeptidase N/CD13. We propose caveolae/rafts to be peptidase-rich 'hot-spot' regions of the synoviocyte plasma membrane required for functional cell-cell interactions with lymphocytes...

  9. Mass spectrometric analysis of the glycosphingolipid-enriched microdomains of rat natural killer cells

    Czech Academy of Sciences Publication Activity Database

    Man, Petr; Novák, Petr; Cebecauer, M.; Horváth, Ondřej; Fišerová, Anna; Havlíček, Vladimír; Bezouška, Karel

    2005-01-01

    Roč. 5, - (2005), s. 113-122 ISSN 1615-9853 R&D Projects: GA ČR GV312/98/K034 Institutional research plan: CEZ:AV0Z5020903 Keywords : activation receptor * mebrane microdomains * natural killer cells Subject RIV: EE - Microbiology, Virology Impact factor: 6.088, year: 2005

  10. The way we view cellular (glyco)sphingolipids.

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    Hoetzl, Sandra; Sprong, Hein; van Meer, Gerrit

    2007-11-01

    Mammalian cells synthesize ceramide in the endoplasmic reticulum (ER) and convert this to sphingomyelin and complex glycosphingolipids on the inner, non-cytosolic surface of Golgi cisternae. From there, these lipids travel towards the outer, non-cytosolic surface of the plasma membrane and all membranes of the endocytic system, where they are eventually degraded. At the basis of the selective, anterograde traffic out of the Golgi lies the propensity of the sphingolipids to self-aggregate with cholesterol into microdomains termed 'lipid rafts'. At the plasma membrane surface these rafts are thought to function as the scaffold for various types of (glyco) signaling domains of different protein and lipid composition that can co-exist on one and the same cell. In the past decade, various unexpected findings on the sites where sphingolipid-mediated events occur have thrown a new light on the localization and transport mechanisms of sphingolipids. These findings are largely based on biochemical experiments. Further progress in the field is hampered by a lack of morphological techniques to localize lipids with nanometer resolution. In the present paper, we critically evaluate the published data and discuss techniques and potential improvements.

  11. Promotion of bone morphogenetic protein signaling by tetraspanins and glycosphingolipids.

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    Zhiyu Liu

    2015-05-01

    Full Text Available Bone morphogenetic proteins (BMPs belong to the transforming growth factor β (TGFβ superfamily of secreted molecules. BMPs play essential roles in multiple developmental and homeostatic processes in metazoans. Malfunction of the BMP pathway can cause a variety of diseases in humans, including cancer, skeletal disorders and cardiovascular diseases. Identification of factors that ensure proper spatiotemporal control of BMP signaling is critical for understanding how this pathway is regulated. We have used a unique and sensitive genetic screen to identify the plasma membrane-localized tetraspanin TSP-21 as a key new factor in the C. elegans BMP-like "Sma/Mab" signaling pathway that controls body size and postembryonic M lineage development. We showed that TSP-21 acts in the signal-receiving cells and genetically functions at the ligand-receptor level. We further showed that TSP-21 can associate with itself and with two additional tetraspanins, TSP-12 and TSP-14, which also promote Sma/Mab signaling. TSP-12 and TSP-14 can also associate with SMA-6, the type I receptor of the Sma/Mab pathway. Finally, we found that glycosphingolipids, major components of the tetraspanin-enriched microdomains, are required for Sma/Mab signaling. Our findings suggest that the tetraspanin-enriched membrane microdomains are important for proper BMP signaling. As tetraspanins have emerged as diagnostic and prognostic markers for tumor progression, and TSP-21, TSP-12 and TSP-14 are all conserved in humans, we speculate that abnormal BMP signaling due to altered expression or function of certain tetraspanins may be a contributing factor to cancer development.

  12. The repertoire of glycosphingolipids recognized by Vibrio cholerae.

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    John Benktander

    Full Text Available The binding of cholera toxin to the ganglioside GM1 as the initial step in the process leading to diarrhea is nowadays textbook knowledge. In contrast, the knowledge about the mechanisms for attachment of Vibrio cholerae bacterial cells to the intestinal epithelium is limited. In order to clarify this issue, a large number of glycosphingolipid mixtures were screened for binding of El Tor V. cholerae. Several specific interactions with minor complex non-acid glycosphingolipids were thereby detected. After isolation of binding-active glycosphingolipids, characterization by mass spectrometry and proton NMR, and comparative binding studies, three distinct glycosphingolipid binding patterns were defined. Firstly, V. cholerae bound to complex lacto/neolacto glycosphingolipids with the GlcNAcβ3Galβ4GlcNAc sequence as the minimal binding epitope. Secondly, glycosphingolipids with a terminal Galα3Galα3Gal moiety were recognized, and the third specificity was the binding to lactosylceramide and related compounds. V. cholerae binding to lacto/neolacto glycosphingolipids, and to the other classes of binding-active compounds, remained after deletion of the chitin binding protein GbpA. Thus, the binding of V. cholerae to chitin and to lacto/neolacto containing glycosphingolipids represents two separate binding specificities.

  13. The occurrence of a phosphorylated glycosphingolipid in Aspergillus niger.

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    Brennan, P J; Roe, J

    1975-01-01

    A novel type of water-soluble phosphorylated glycosphingolipid was isolated from Aspergillus niger by a simple procedure involving precipitation, DEAE-cellulose chromatography and preparative t.l.c. Besides ceramide and phosphorus it contains inositol, galactose, mannose and small amounts of glucosamine. Images PLATE 1 PMID:1156383

  14. Membrane-Sculpting BAR Domains Generate Stable Lipid Microdomains

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    Zhao, Hongxia; Michelot, Alphée; Koskela, Essi V.; Tkach, Vadym; Stamou, Dimitrios; Drubin, David G.; Lappalainen, Pekka

    2014-01-01

    SUMMARY Bin-Amphiphysin-Rvs (BAR) domain proteins are central regulators of many cellular processes involving membrane dynamics. BAR domains sculpt phosphoinositide-rich membranes to generate membrane protrusions or invaginations. Here, we report that, in addition to regulating membrane geometry, BAR domains can generate extremely stable lipid microdomains by “freezing” phosphoinositide dynamics. This is a general feature of BAR domains, because the yeast endocytic BAR and Fes/CIP4 homology BAR (F-BAR) domains, the inverse BAR domain of Pinkbar, and the eisosomal BAR protein Lsp1 induced phosphoinositide clustering and halted lipid diffusion, despite differences in mechanisms of membrane interactions. Lsp1 displays comparable low diffusion rates in vitro and in vivo, suggesting that BAR domain proteins also generate stable phosphoinositide microdomains in cells. These results uncover a conserved role for BAR superfamily proteins in regulating lipid dynamics within membranes. Stable microdomains induced by BAR domain scaffolds and specific lipids can generate phase boundaries and diffusion barriers, which may have profound impacts on diverse cellular processes. PMID:24055060

  15. Imaging alterations of cardiomyocyte cAMP microdomains in disease

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    Alexander eFroese

    2015-08-01

    Full Text Available 3’,5’-cyclic adenosine monophosphate (cAMP is an important second messenger which regulates heart function by acting in distinct subcellular microdomains. Recent years have provided deeper mechanistic insights into compartmentalized cAMP signaling and its link to cardiac disease. In this mini review, we summarize newest developments in this field achieved by cutting-edge biochemical and biophysical techniques. We further compile the data from different studies into a bigger picture of so far uncovered alterations in cardiomyocyte cAMP microdomains which occur in compensated cardiac hypertrophy and chronic heart failure. Finally, future research directions and translational perspectives are briefly discussed.

  16. Involvement of glycosphingolipid-enriched lipid rafts in inflammatory responses.

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    Iwabuchi, Kazuhisa

    2015-01-01

    Glycosphingolipids (GSLs) are membrane components consisting of hydrophobic ceramide and hydrophilic sugar moieties. GSLs cluster with cholesterol in cell membranes to form GSL-enriched lipid rafts. Biochemical analyses have demonstrated that GSL-enriched lipid rafts contain several kinds of transducer molecules, including Src family kinases. Among the GSLs, lactosylceramide (LacCer, CDw17) can bind to various microorganisms, is highly expressed on the plasma membranes of human phagocytes, and forms lipid rafts containing the Src family tyrosine kinase Lyn. LacCer-enriched lipid rafts mediate immunological and inflammatory reactions, including superoxide generation, chemotaxis, and non-opsonic phagocytosis. Therefore, LacCer-enriched membrane microdomains are thought to function as pattern recognition receptors (PRRs), which recognize pathogen-associated molecular patterns (PAMPs) expressed on microorganisms. LacCer also serves as a signal transduction molecule for functions mediated by CD11b/CD18-integrin (αM/β2-integrin, CR3, Mac-1), as well as being associated with several key cellular processes. LacCer recruits PCKα/ε and phospholipase A2 to stimulate PECAM-1 expression in human monocytes and their adhesion to endothelial cells, as well as regulating β1-integrin clustering and endocytosis on cell surfaces. This review describes the organizational and inflammation-related functions of LacCer-enriched lipid rafts.

  17. Glycosphingolipid antigens from Leishmania (L. amazonensis amastigotes: Binding of anti-glycosphingolipid monoclonal antibodies in vitro and in vivo

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    A.H. Straus

    1997-03-01

    Full Text Available Specific glycosphingolipid antigens of Leishmania (L. amazonensis amastigotes reactive with the monoclonal antibodies (MoAbs ST-3, ST-4 and ST-5 were isolated, and their structure was partially elucidated by negative ion fast atom bombardment mass spectrometry. The glycan moieties of five antigens presented linear sequences of hexoses and N-acetylhexosamines ranging from four to six sugar residues, and the ceramide moieties were found to be composed by a sphingosine d18:1 and fatty acids 24:1 or 16:0. Affinities of the three monoclonal antibodies to amastigote glycosphingolipid antigens were also analyzed by ELISA. MoAb ST-3 reacted equally well with all glycosphingolipid antigens tested, whereas ST-4 and ST-5 presented higher affinities to glycosphingolipids with longer carbohydrate chains, with five or more sugar units (slow migrating bands on HPTLC. Macrophages isolated from footpad lesions of BALB/c mice infected with Leishmania (L. amazonensis were incubated with MoAb ST-3 and, by indirect immunofluorescence, labeling was only detected on the parasite, whereas no fluorescence was observed on the surface of the infected macrophages, indicating that these glycosphingolipid antigens are not acquired from the host cell but synthesized by the amastigote. Intravenous administration of 125I-labeled ST-3 antibody to infected BALB/c mice showed that MoAb ST-3 accumulated significantly in the footpad lesions in comparison to blood and other tissues

  18. Egghead and brainiac are essential for glycosphingolipid biosynthesis in vivo

    DEFF Research Database (Denmark)

    Wandall, Hans H; Pizette, Sandrine; Pedersen, Johannes W

    2004-01-01

    -acetylglucosaminyltransferase predicted by in vitro analysis to control synthesis of the glycosphingolipid core structure, GlcNAcbeta1-3Manbeta1-4Glcbeta1-Cer, found widely in invertebrates but not vertebrates. In this report we present direct in vivo evidence for this hypothesis. egghead and brainiac mutants lack elongated...... lactosylceramide glycosphingolipid biosynthetic pathway (Galbeta1-4Glcbeta1-Cer) using a human beta4-galactosyltransferase (beta4Gal-T6) transgene. Conversely, introduction of egghead in vertebrate cells (Chinese hamster ovary) resulted in near complete blockage of biosynthesis of glycosphingolipids...... and accumulation of Manbeta1-4Glcbeta1-Cer. The study demonstrates that glycosphingolipids are essential for development of complex organisms and suggests that the function of the Drosophila glycosphingolipids in development does not depend on the core structure....

  19. Membrane-sculpting BAR domains generate stable lipid microdomains

    DEFF Research Database (Denmark)

    Zhao, Hongxia; Michelot, Alphée; Koskela, Essi V.

    2013-01-01

    Bin-Amphiphysin-Rvs (BAR) domain proteins are central regulators of many cellular processes involving membrane dynamics. BAR domains sculpt phosphoinositide-rich membranes to generate membrane protrusions or invaginations. Here, we report that, in addition to regulating membrane geometry, BAR...... domains can generate extremely stable lipid microdomains by "freezing" phosphoinositide dynamics. This is a general feature of BAR domains, because the yeast endocytic BAR and Fes/CIP4 homology BAR (F-BAR) domains, the inverse BAR domain of Pinkbar, and the eisosomal BAR protein Lsp1 induced...... phosphoinositide clustering and halted lipid diffusion, despite differences in mechanisms of membrane interactions. Lsp1 displays comparable low diffusion rates in vitro and in vivo, suggesting that BAR domain proteins also generate stable phosphoinositide microdomains in cells. These results uncover a conserved...

  20. A novel biotinylated lipid raft reporter for electron microscopic imaging of plasma membrane microdomains[S

    Science.gov (United States)

    Krager, Kimberly J.; Sarkar, Mitul; Twait, Erik C.; Lill, Nancy L.; Koland, John G.

    2012-01-01

    The submicroscopic spatial organization of cell surface receptors and plasma membrane signaling molecules is readily characterized by electron microscopy (EM) via immunogold labeling of plasma membrane sheets. Although various signaling molecules have been seen to segregate within plasma membrane microdomains, the biochemical identity of these microdomains and the factors affecting their formation are largely unknown. Lipid rafts are envisioned as submicron membrane subdomains of liquid ordered structure with differing lipid and protein constituents that define their specific varieties. To facilitate EM investigation of inner leaflet lipid rafts and the localization of membrane proteins therein, a unique genetically encoded reporter with the dually acylated raft-targeting motif of the Lck kinase was developed. This reporter, designated Lck-BAP-GFP, incorporates green fluorescent protein (GFP) and biotin acceptor peptide (BAP) modules, with the latter allowing its single-step labeling with streptavidin-gold. Lck-BAP-GFP was metabolically biotinylated in mammalian cells, distributed into low-density detergent-resistant membrane fractions, and was readily detected with avidin-based reagents. In EM images of plasma membrane sheets, the streptavidin-gold-labeled reporter was clustered in 20–50 nm microdomains, presumably representative of inner leaflet lipid rafts. The utility of the reporter was demonstrated in an investigation of the potential lipid raft localization of the epidermal growth factor receptor. PMID:22822037

  1. The membrane-associated form of α(s1-casein interacts with cholesterol-rich detergent-resistant microdomains.

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    Annabelle Le Parc

    Full Text Available Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established. There is a growing body of evidence to support the concept that α(s1-casein takes center stage in casein micelle building and transport in the secretory pathway of mammary epithelial cells. Here we have investigated the membrane-associated form of α(s1-casein in rat mammary epithelial cells. Using metabolic labelling we show that α(s1-casein becomes associated with membranes at the level of the endoplasmic reticulum, with no subsequent increase at the level of the Golgi apparatus. From morphological and biochemical data, it appears that caseins are in a tight relationship with membranes throughout the secretory pathway. On the other hand, we have observed that the membrane-associated form of α(s1-casein co-purified with detergent-resistant membranes. It was poorly solubilised by Tween 20, partially insoluble in Lubrol WX, and substantially insoluble in Triton X-100. Finally, we found that cholesterol depletion results in the release of the membrane-associated form of α(s1-casein. These experiments reveal that the insolubility of α(s1-casein reflects its partial association with a cholesterol-rich detergent-resistant microdomain. We propose that the membrane-associated form of α(s1-casein interacts with the lipid microdomain, or lipid raft, that forms within the membranes of the endoplasmic reticulum, for efficient forward transport and sorting in the secretory pathway of mammary epithelial cells.

  2. The Membrane-Associated Form of αs1-Casein Interacts with Cholesterol-Rich Detergent-Resistant Microdomains

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    Le Parc, Annabelle; Honvo Houéto, Edith; Pigat, Natascha; Chat, Sophie; Leonil, Joëlle; Chanat, Eric

    2014-01-01

    Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established. There is a growing body of evidence to support the concept that αs1-casein takes center stage in casein micelle building and transport in the secretory pathway of mammary epithelial cells. Here we have investigated the membrane-associated form of αs1-casein in rat mammary epithelial cells. Using metabolic labelling we show that αs1-casein becomes associated with membranes at the level of the endoplasmic reticulum, with no subsequent increase at the level of the Golgi apparatus. From morphological and biochemical data, it appears that caseins are in a tight relationship with membranes throughout the secretory pathway. On the other hand, we have observed that the membrane-associated form of αs1-casein co-purified with detergent-resistant membranes. It was poorly solubilised by Tween 20, partially insoluble in Lubrol WX, and substantially insoluble in Triton X-100. Finally, we found that cholesterol depletion results in the release of the membrane-associated form of αs1-casein. These experiments reveal that the insolubility of αs1-casein reflects its partial association with a cholesterol-rich detergent-resistant microdomain. We propose that the membrane-associated form of αs1-casein interacts with the lipid microdomain, or lipid raft, that forms within the membranes of the endoplasmic reticulum, for efficient forward transport and sorting in the secretory pathway of mammary epithelial cells. PMID:25549363

  3. The membrane-associated form of α(s1)-casein interacts with cholesterol-rich detergent-resistant microdomains.

    Science.gov (United States)

    Le Parc, Annabelle; Honvo Houéto, Edith; Pigat, Natascha; Chat, Sophie; Leonil, Joëlle; Chanat, Eric

    2014-01-01

    Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established. There is a growing body of evidence to support the concept that α(s1)-casein takes center stage in casein micelle building and transport in the secretory pathway of mammary epithelial cells. Here we have investigated the membrane-associated form of α(s1)-casein in rat mammary epithelial cells. Using metabolic labelling we show that α(s1)-casein becomes associated with membranes at the level of the endoplasmic reticulum, with no subsequent increase at the level of the Golgi apparatus. From morphological and biochemical data, it appears that caseins are in a tight relationship with membranes throughout the secretory pathway. On the other hand, we have observed that the membrane-associated form of α(s1)-casein co-purified with detergent-resistant membranes. It was poorly solubilised by Tween 20, partially insoluble in Lubrol WX, and substantially insoluble in Triton X-100. Finally, we found that cholesterol depletion results in the release of the membrane-associated form of α(s1)-casein. These experiments reveal that the insolubility of α(s1)-casein reflects its partial association with a cholesterol-rich detergent-resistant microdomain. We propose that the membrane-associated form of α(s1)-casein interacts with the lipid microdomain, or lipid raft, that forms within the membranes of the endoplasmic reticulum, for efficient forward transport and sorting in the secretory pathway of mammary epithelial cells.

  4. Functional microdomains in bacterial membranes.

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    López, Daniel; Kolter, Roberto

    2010-09-01

    The membranes of eukaryotic cells harbor microdomains known as lipid rafts that contain a variety of signaling and transport proteins. Here we show that bacterial membranes contain microdomains functionally similar to those of eukaryotic cells. These membrane microdomains from diverse bacteria harbor homologs of Flotillin-1, a eukaryotic protein found exclusively in lipid rafts, along with proteins involved in signaling and transport. Inhibition of lipid raft formation through the action of zaragozic acid--a known inhibitor of squalene synthases--impaired biofilm formation and protein secretion but not cell viability. The orchestration of physiological processes in microdomains may be a more widespread feature of membranes than previously appreciated.

  5. Glycosphingolipids and insulin resistance

    NARCIS (Netherlands)

    Langeveld, Mirjam; Aerts, Johannes M. F. G.

    2009-01-01

    Obesity is associated with an increased risk for insulin resistance, a state characterized by impaired responsiveness of liver, muscle and adipose tissue to insulin. One class of lipids involved in the development of insulin resistance are the (glyco)sphingolipids. Ceramide, the most simple

  6. Microdomain forming proteins in oncogenesis

    Directory of Open Access Journals (Sweden)

    I. B. Zborovskaya

    2016-01-01

    Full Text Available Lipid rafts are lateral assembles of cholesterol, sphingomyelin, glicosphingolipids and specific proteins within cell plasma membrane. These microdomains are involved into a number of important cellular processes including membrane rearrangement, protein internalization, signal transduction, entry of viruses into the cell. Some of lipid rafts are stabilized by special microdomain-forming proteins such as caveolins, SPFH domain containing superfamily, tetraspanins, galectins, which maintain integrity of rafts and regulate signal transduction via forming of “signalosomes”. Involvement of the different lipid rafts is necessary in many situations such as binding of growth factors with their receptors, integrin regulation, cytoskeleton and extracellular matrix rearrangements, vesicular transport, etc. However, such classes of microdomain-forming proteins are still considered separately from each other. In this review we tried to perform complex analysis of microdomain-forming proteins in regulation of cancer assotiated processes.

  7. Lactotetraosylceramide, a novel glycosphingolipid receptor for Helicobacter pylori, present in human gastric epithelium

    OpenAIRE

    Teneberg, Susann; Leonardsson, Iréne; Karlsson, Hasse; Jovall, Per-Åke; Ångström, Jonas; Danielsson, Dan; Näslund, Ingmar; Ljungh, Åsa; Wadström, Torkel; Karlsson, Karl-Anders

    2002-01-01

    The binding of Helicobacter pylori to glycosphingolipids was examined by binding of 35S-labeled bacteria to glycosphingolipids on thin-layer chromatograms. In addition to previously reported binding specificities, a selective binding to a non-acid tetraglycosylceramide of human meconium was found. This H. pylori binding glycosphingolipid was isolated and, on the basis of mass spectrometry, proton NMR spectroscopy, and degradation studies, were identified as Gal3GlcNAc3Gal4Glc1Cer (lactotetrao...

  8. Use of dansyl-cholestanol as a probe of cholesterol behavior in membranes of living cells[S

    Science.gov (United States)

    Huang, Huan; McIntosh, Avery L.; Atshaves, Barbara P.; Ohno-Iwashita, Yoshiko; Kier, Ann B.; Schroeder, Friedhelm

    2010-01-01

    While plasma membrane cholesterol-rich microdomains play a role in cholesterol trafficking, little is known about the appearance and dynamics of cholesterol through these domains in living cells. The fluorescent cholesterol analog 6-dansyl-cholestanol (DChol), its biochemical fractionation, and confocal imaging of L-cell fibroblasts contributed the following new insights: i) fluorescence properties of DChol were sensitive to microenvironment polarity and mobility; (ii) DChol taken up by L-cell fibroblasts was distributed similarly as cholesterol and preferentially into cholesterol-rich vs. -poor microdomains resolved by affinity chromatography of purified plasma membranes; iii) DChol reported similar polarity (dielectric constant near 18) but higher mobility near phospholipid polar head group region for cholesterol in purified cholesterol-rich versus -poor microdomains; and iv) real-time confocal imaging, quantitative colocalization analysis, and fluorescence resonance energy transfer with cholesterol-rich and -poor microdomain markers confirmed that DChol preferentially localized in plasma membrane cholesterol-rich microdomains of living cells. Thus, DChol sensed a unique, relatively more mobile microenvironment for cholesterol in plasma membrane cholesterol-rich microdomains, consistent with the known, more rapid exchange dynamics of cholesterol from cholesterol-rich than -poor microdomains. PMID:20008119

  9. Functional imaging of microdomains in cell membranes.

    Science.gov (United States)

    Duggan, James; Jamal, Ghadir; Tilley, Mark; Davis, Ben; McKenzie, Graeme; Vere, Kelly; Somekh, Michael G; O'Shea, Paul; Harris, Helen

    2008-10-01

    The presence of microdomains or rafts within cell membranes is a topic of intense study and debate. The role of these structures in cell physiology, however, is also not yet fully understood with many outstanding problems. This problem is partly based on the small size of raft structures that presents significant problems to their in vivo study, i.e., within live cell membranes. But the structure and dynamics as well as the factors that control the assembly and disassembly of rafts are also of major interest. In this review we outline some of the problems that the study of rafts in cell membranes present as well as describing some views of what are considered the generalised functions of membrane rafts. We point to the possibility that there may be several different 'types' of membrane raft in cell membranes and consider the factors that affect raft assembly and disassembly, particularly, as some researchers suggest that the lifetimes of rafts in cell membranes may be sub-second. We attempt to review some of the methods that offer the ability to interrogate rafts directly as well as describing factors that appear to affect their functionality. The former include both near-field and far-field optical approaches as well as scanning probe techniques. Some of the advantages and disadvantages of these techniques are outlined. Finally, we describe our own views of raft functionality and properties, particularly, concerning the membrane dipole potential, and describe briefly some of the imaging strategies we have developed for their study.

  10. A novel method for analysis of membrane microdomains: vesicular stomatitis virus glycoprotein microdomains change in size during infection, and those outside of budding sites resemble sites of virus budding

    International Nuclear Information System (INIS)

    Brown, Erica L.; Lyles, Douglas S.

    2003-01-01

    Membrane proteins, including viral envelope glycoproteins, may be organized into areas of locally high concentration, commonly referred to as membrane microdomains. Some viruses bud from detergent-resistant microdomains referred to as lipid rafts. However, vesicular stomatitis virus (VSV) serves as a prototype for viruses that bud from areas of plasma membrane that are not detergent resistant. We developed a new analytical method for immunoelectron microscopy data to determine whether the VSV envelope glycoprotein (G protein) is organized into plasma membrane microdomains. This method was used to quantify the distribution of the G protein in microdomains in areas of plasma membrane that did not contain budding sites. These microdomains were compared to budding virus envelopes to address the question of whether G protein-containing microdomains were formed only at the sites of budding. At early times postinfection, most of the G protein was organized into membrane microdomains outside of virus budding sites that were approximately 100-150 nm, with smaller amounts distributed into larger microdomains. In contrast to early times postinfection, the increased level of G protein in the host plasma membrane at later times postinfection led to distribution of G protein among membrane microdomains of a wider variety of sizes, rather than a higher G protein concentration in the 100- to 150-nm microdomains. VSV budding occurred in G protein-containing microdomains with a range of sizes, some of which were smaller than the virus envelope. These microdomains extended in size to a maximum of 300-400 nm from the tip of the budding virion. The data support a model for virus assembly in which G protein organizes into membrane microdomains that resemble virus envelopes prior to formation of budding sites, and these microdomains serve as the sites of assembly of internal virion components

  11. Reversible Dissolution of Microdomains in Detergent-Resistant Membranes at Physiological Temperature.

    Directory of Open Access Journals (Sweden)

    Andrea Cremona

    Full Text Available The formation of lipid microdomains ("rafts" is presumed to play an important role in various cellular functions, but their nature remains controversial. Here we report on microdomain formation in isolated, detergent-resistant membranes from MDA-MB-231 human breast cancer cells, studied by atomic force microscopy (AFM. Whereas microdomains were readily observed at room temperature, they shrunk in size and mostly disappeared at higher temperatures. This shrinking in microdomain size was accompanied by a gradual reduction of the height difference between the microdomains and the surrounding membrane, consistent with the behaviour expected for lipids that are laterally segregated in liquid ordered and liquid disordered domains. Immunolabeling experiments demonstrated that the microdomains contained flotillin-1, a protein associated with lipid rafts. The microdomains reversibly dissolved and reappeared, respectively, on heating to and cooling below temperatures around 37 °C, which is indicative of radical changes in local membrane order close to physiological temperature.

  12. Reversible Dissolution of Microdomains in Detergent-Resistant Membranes at Physiological Temperature

    Science.gov (United States)

    Cremona, Andrea; Orsini, Francesco; Corsetto, Paola A.; Hoogenboom, Bart W.; Rizzo, Angela M.

    2015-01-01

    The formation of lipid microdomains (“rafts”) is presumed to play an important role in various cellular functions, but their nature remains controversial. Here we report on microdomain formation in isolated, detergent-resistant membranes from MDA-MB-231 human breast cancer cells, studied by atomic force microscopy (AFM). Whereas microdomains were readily observed at room temperature, they shrunk in size and mostly disappeared at higher temperatures. This shrinking in microdomain size was accompanied by a gradual reduction of the height difference between the microdomains and the surrounding membrane, consistent with the behaviour expected for lipids that are laterally segregated in liquid ordered and liquid disordered domains. Immunolabeling experiments demonstrated that the microdomains contained flotillin-1, a protein associated with lipid rafts. The microdomains reversibly dissolved and reappeared, respectively, on heating to and cooling below temperatures around 37°C, which is indicative of radical changes in local membrane order close to physiological temperature. PMID:26147107

  13. β-glycosphingolipids ameliorated non-alcoholic steatohepatitis in the Psammomys obesus model

    Directory of Open Access Journals (Sweden)

    Zigmond E

    2014-10-01

    Full Text Available Ehud Zigmond,1,* Oshrat Tayer-Shifman,1,* Gadi Lalazar,1 Ami Ben Ya'acov,1 Sarah Weksler-Zangen,2 David Shasha,1 Miriam Sklair-Levy,3 Lidya Zolotarov,1 Zvi Shalev,1 Rony Kalman,2 Ehud Ziv,2 Itamar Raz,2 Yaron Ilan1 1Liver Unit, 2Diabetes Unit, 3Department of Radiology, Hebrew University-Hadassah Medical Center, Jerusalem, Israel *These authors contributed equally to this workAbstract: Liver steatosis is a common characteristic of obesity and type 2 diabetes, and fatty liver disease is increasingly recognized as a major health burden. Accumulating evidence suggests that β-glycosphingolipids play an important role in insulin sensitivity and thus could affect hepatic steatosis. To determine the effect associated with β-glycosphingolipid-mediated amelioration of liver injury, seven groups of Psammomys obesus on a high-energy diet were studied. Animals were treated with daily injections of β-glucosylceramide, β-lactosylceramide, or a combination of both. β-glycosphingolipids ameliorated the hepatic injury manifested by decreased liver enzymes, liver weight, and hepatic fat, and improved liver histology. Administration of both β-glucosylceramide and β-lactosylceramide also decreased interferon (IFN-γ serum levels. These effects were associated with improved serum cholesterol and triglyceride levels. These data suggest that β-glycosphingolipids ameliorate liver injury in an animal model of nonalcoholic steatohepatitis.Keywords: NAFLD, glycolipids, STAT, NASH, insulin resistance, diabetes

  14. Reversible Dissolution of Microdomains in Detergent-Resistant Membranes at Physiological Temperature

    OpenAIRE

    Cremona, A.; Orsini, F.; Corsetto, P.A.; Hoogenboom, B.W.; Rizzo, A.M.

    2015-01-01

    The formation of lipid microdomains ("rafts") is presumed to play an important role in various cellular functions, but their nature remains controversial. Here we report on microdomain formation in isolated, detergent-resistant membranes from MDA-MB-231 human breast cancer cells, studied by atomic force microscopy (AFM). Whereas microdomains were readily observed at room temperature, they shrunk in size and mostly disappeared at higher temperatures. This shrinking in microdomain size was acco...

  15. Adamantyl Glycosphingolipids Provide a New Approach to the Selective Regulation of Cellular Glycosphingolipid Metabolism*

    OpenAIRE

    Kamani, Mustafa; Mylvaganam, Murugesapillai; Tian, Robert; Rigat, Brigitte; Binnington, Beth; Lingwood, Clifford

    2011-01-01

    Mammalian glycosphingolipid (GSL) precursor monohexosylceramides are either glucosyl- or galactosylceramide (GlcCer or GalCer). Most GSLs derive from GlcCer. Substitution of the GSL fatty acid with adamantane generates amphipathic mimics of increased water solubility, retaining receptor function. We have synthesized adamantyl GlcCer (adaGlcCer) and adamantyl GalCer (adaGalCer). AdaGlcCer and adaGalCer partition into cells to alter GSL metabolism. At low dose, adaGlcCer increased cellular GSLs...

  16. Comparison of the glycosphingolipids of human-induced pluripotent stem cells and human embryonic stem cells.

    Science.gov (United States)

    Säljö, Karin; Barone, Angela; Vizlin-Hodzic, Dzeneta; Johansson, Bengt R; Breimer, Michael E; Funa, Keiko; Teneberg, Susann

    2017-04-01

    High expectations are held for human-induced pluripotent stem cells (hiPSC) since they are established from autologous tissues thus overcoming the risk of allogeneic immune rejection when used in regenerative medicine. However, little is known regarding the cell-surface carbohydrate antigen profile of hiPSC compared with human embryonic stem cells (hESC). Here, glycosphingolipids were isolated from an adipocyte-derived hiPSC line, and hiPSC and hESC glycosphingolipids were compared by concurrent characterization by binding assays with carbohydrate-recognizing ligands and mass spectrometry. A high similarity between the nonacid glycosphingolipids of hiPSC and hESC was found. The nonacid glycosphingolipids P1 pentaosylceramide, x2 pentaosylceramide and H type 1 heptaosylceramide, not previously described in human pluripotent stem cells (hPSC), were characterized in both hiPSC and hESC. The composition of acid glycosphingolipids differed, with increased levels of GM3 ganglioside, and reduced levels of GD1a/GD1b in hiPSC when compared with hESC. In addition, the hESC glycosphingolipids sulf-globopentaosylceramide and sialyl-globotetraosylceramide were lacking in hiPSC. Neural stem cells differentiating from hiPSC had a reduced expression of sialyl-lactotetra, whereas expression of the GD1a ganglioside was significantly increased. Thus, while sialyl-lactotetra is a marker of undifferentiated hPSC, GD1a is a novel marker of neural differentiation. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Glycosynapses: microdomains controlling carbohydrate-dependent cell adhesion and signaling

    Directory of Open Access Journals (Sweden)

    Senitiroh Hakomori

    2004-09-01

    Full Text Available The concept of microdomains in plasma membranes was developed over two decades, following observation of polarity of membrane based on clustering of specific membrane components. Microdomains involved in carbohydrate-dependent cell adhesion with concurrent signal transduction that affect cellular phenotype are termed "glycosynapse". Three types of glycosynapse have been distinguished: "type 1" having glycosphingolipid associated with signal transducers (small G-proteins, cSrc, Src family kinases and proteolipids; "type 2" having O-linked mucin-type glycoprotein associated with Src family kinases; and "type 3" having N-linked integrin receptor complexed with tetraspanin and ganglioside. Different cell types are characterized by presence of specific types of glycosynapse or their combinations, whose adhesion induces signal transduction to either facilitate or inhibit signaling. E.g., signaling through type 3 glycosynapse inhibits cell motility and differentiation. Glycosynapses are distinct from classically-known microdomains termed "caveolae", "caveolar membrane", or more recently "lipid raft", which are not involved in carbohydrate-dependent cell adhesion. Type 1 and type 3 glycosynapses are resistant to cholesterol-binding reagents, whereas structure and function of "caveolar membrane" or "lipid raft" are disrupted by these reagents. Various data indicate a functional role of glycosynapses during differentiation, development, and oncogenic transformation.O conceito de microdomínios em membrana plasmática foi desenvolvido há mais de duas décadas, após a observação da polaridade da membrana baseada no agrupamento de componentes específicos da membrana. Microdomínios envolvidos na adesão celular dependente de carboidrato, com transdução de sinal que afeta o fenótipo celular são denominados ''glicosinapses''. Três tipos de glicosinapse foram observados: ''tipo 1'' que possue glicoesfingolipídio associado com transdutores de sinal

  18. Membrane microdomains, rafts, and detergent-resistant membranes in plants and fungi.

    Science.gov (United States)

    Malinsky, Jan; Opekarová, Miroslava; Grossmann, Guido; Tanner, Widmar

    2013-01-01

    The existence of specialized microdomains in plasma membranes, postulated for almost 25 years, has been popularized by the concept of lipid or membrane rafts. The idea that detergent-resistant membranes are equivalent to lipid rafts, which was generally abandoned after a decade of vigorous data accumulation, contributed to intense discussions about the validity of the raft concept. The existence of membrane microdomains, meanwhile, has been verified by unequivocal independent evidence. This review summarizes the current state of research in plants and fungi with respect to common aspects of both kingdoms. In these organisms, principally immobile microdomains large enough for microscopic detection have been visualized. These microdomains are found in the context of cell-cell interactions (plant symbionts and pathogens), membrane transport, stress, and polarized growth, and the data corroborate at least three mechanisms of formation. As documented in this review, modern methods of visualization of lateral membrane compartments are also able to uncover the functional relevance of membrane microdomains.

  19. Two new protease-inhibiting glycosphingolipids from Buddleja crispa.

    Science.gov (United States)

    Ahmad, Ijaz; Anis, Itrat; Fatima, Itrat; Malik, Abdul; Khan, Shafiullah; Afza, Nighat; Tareen, Rasool Bakhsh; Lodhi, Muhammad Arif; Choudhary, M Iqbal

    2007-05-01

    Crispins A (1) and B (2), two new glycosphingolipids, were isolated from the whole plant Buddleja crispa, along with three known compounds: alpha-amyrin, linoleic acid, and stigmasterol. Their structures were elucidated by chemical and spectroscopic techniques. Both 1 and 2 showed significant inhibitory activity against alpha-chymotrypsin in a concentration-dependent manner.

  20. Inhibiting Glycosphingolipid Synthesis Ameliorates Hepatic Steatosis in Obese Mice

    NARCIS (Netherlands)

    Zhao, Hongmei; Przybylska, Malgorzata; Wu, I.-Huan; Zhang, Jinhua; Maniatis, Panagiotis; Pacheco, Joshua; Piepenhagen, Peter; Copeland, Diane; Arbeeny, Cynthia; Shayman, James A.; Aerts, Johannes M.; Jiang, Canwen; Cheng, Seng H.; Yew, Nelson S.

    2009-01-01

    Steatosis in the liver is a common feature of obesity and type 2 diabetes and the precursor to the development of nonalcoholic steatohepatitis (NASH), cirrhosis, and liver failure. It has been shown previously that inhibiting glycosphingolipid (GSL) synthesis increases insulin sensitivity and lowers

  1. Function of plasma membrane microdomain-associated proteins during legume nodulation.

    Science.gov (United States)

    Qiao, Zhenzhen; Libault, Marc

    2017-10-03

    Plasma membrane microdomains are plasma membrane sub-compartments enriched in sphingolipids and sterols, and composed by a specific set of proteins. They are involved in recognizing signal molecules, transducing these signals, and controlling endocytosis and exocytosis processes. In a recent study, applying biochemical and microscopic methods, we characterized the soybean GmFWL1 protein, a major regulator of soybean nodulation, as a new membrane microdomain-associated protein. Interestingly, upon rhizobia inoculation of the soybean root system, GmFWL1 and one of its interacting partners, GmFLOT2/4, both translocate to the root hair cell tip, the primary site of interaction and infection between soybean and Rhizobium. The role of GmFWL1 as a plasma membrane microdomain-associated protein is also supported by immunoprecipitation assays performed on soybean nodules, which revealed 178 GmFWL1 protein partners including a large number of microdomain-associated proteins such as GmFLOT2/4. In this addendum, we provide additional information about the identity of the soybean proteins repetitively identified as GmFWL1 protein partners. Their function is discussed especially in regard to plant-microbe interactions and microbial symbiosis. This addendum will provide new insights in the role of plasma membrane microdomains in regulating legume nodulation.

  2. Eye lens membrane junctional microdomains: a comparison between healthy and pathological cases

    Energy Technology Data Exchange (ETDEWEB)

    Buzhynskyy, Nikolay; Scheuring, Simon [Institut Curie, Equipe Inserm Avenir, UMR168-CNRS, 26 Rue d' Ulm, 75248 Paris Cedex 05 (France); Sens, Pierre [ESPCI, CNRS-UMR 7083, 75231 Paris (France); Behar-Cohen, Francine, E-mail: simon.scheuring@curie.fr [UMRS Inserm 872, Universite Paris Descartes, Centre de Recherches des Cordeliers, 15 rue de l' Ecole de Medecine, 75270 Paris Cedex 06 (France)

    2011-08-15

    The eye lens is a transparent tissue constituted of tightly packed fiber cells. To maintain homeostasis and transparency of the lens, the circulation of water, ions and metabolites is required. Junctional microdomains connect the lens cells and ensure both tight cell-to-cell adhesion and intercellular flow of fluids through a microcirculation system. Here, we overview membrane morphology and tissue functional requirements of the mammalian lens. Atomic force microscopy (AFM) has opened up the possibility of visualizing the junctional microdomains at unprecedented submolecular resolution, revealing the supramolecular assembly of lens-specific aquaporin-0 (AQP0) and connexins (Cx). We compare the membrane protein assembly in healthy lenses with senile and diabetes-II cataract cases and novel data of the lens membranes from a congenital cataract. In the healthy case, AQP0s form characteristic square arrays confined by connexons. In the cases of senile and diabetes-II cataract patients, connexons were degraded, leading to malformation of AQP0 arrays and breakdown of the microcirculation system. In the congenital cataract, connexons are present, indicating probable non-membranous grounds for lens opacification. Further, we discuss the energetic aspects of the membrane organization in junctional microdomains. The AFM hence becomes a biomedical nano-imaging tool for the analysis of single-membrane protein supramolecular association in healthy and pathological membranes.

  3. Eye lens membrane junctional microdomains: a comparison between healthy and pathological cases

    Science.gov (United States)

    Buzhynskyy, Nikolay; Sens, Pierre; Behar-Cohen, Francine; Scheuring, Simon

    2011-08-01

    The eye lens is a transparent tissue constituted of tightly packed fiber cells. To maintain homeostasis and transparency of the lens, the circulation of water, ions and metabolites is required. Junctional microdomains connect the lens cells and ensure both tight cell-to-cell adhesion and intercellular flow of fluids through a microcirculation system. Here, we overview membrane morphology and tissue functional requirements of the mammalian lens. Atomic force microscopy (AFM) has opened up the possibility of visualizing the junctional microdomains at unprecedented submolecular resolution, revealing the supramolecular assembly of lens-specific aquaporin-0 (AQP0) and connexins (Cx). We compare the membrane protein assembly in healthy lenses with senile and diabetes-II cataract cases and novel data of the lens membranes from a congenital cataract. In the healthy case, AQP0s form characteristic square arrays confined by connexons. In the cases of senile and diabetes-II cataract patients, connexons were degraded, leading to malformation of AQP0 arrays and breakdown of the microcirculation system. In the congenital cataract, connexons are present, indicating probable non-membranous grounds for lens opacification. Further, we discuss the energetic aspects of the membrane organization in junctional microdomains. The AFM hence becomes a biomedical nano-imaging tool for the analysis of single-membrane protein supramolecular association in healthy and pathological membranes.

  4. Membrane microdomains in immunoreceptor signaling

    Czech Academy of Sciences Publication Activity Database

    Hořejší, Václav; Hrdinka, Matouš

    2014-01-01

    Roč. 588, č. 15 (2014), s. 2392-2397 ISSN 0014-5793 R&D Projects: GA ČR(CZ) GBP302/12/G101 Institutional support: RVO:68378050 Keywords : membrane raft * microdomain * immunoreceptor Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.169, year: 2014

  5. Lipidomics of glycosphingolipids.

    Science.gov (United States)

    Farwanah, Hany; Kolter, Thomas

    2012-02-02

    Glycosphingolipids (GSLs) contain one or more sugars that are attached to a sphingolipid moiety, usually to a ceramide, but in rare cases also to a sphingoid base. A large structural heterogeneity results from differences in number, identity, linkage, and anomeric configuration of the carbohydrate residues, and also from structural differences within the hydrophobic part. GSLs form complex cell-type specific patterns, which change with the species, the cellular differentiation state, viral transformation, ontogenesis, and oncogenesis. Although GSL structures can be assigned to only a few series with a common carbohydrate core, their structural variety and the complex pattern are challenges for their elucidation and quantification by mass spectrometric techniques. We present a general overview of the application of lipidomics for GSL determination. This includes analytical procedures and instrumentation together with recent correlations of GSL molecular species with human diseases. Difficulties such as the structural complexity and the lack of standard substances for complex GSLs are discussed.

  6. Lipidomics of Glycosphingolipids

    Directory of Open Access Journals (Sweden)

    Hany Farwanah

    2012-02-01

    Full Text Available Glycosphingolipids (GSLs contain one or more sugars that are attached to a sphingolipid moiety, usually to a ceramide, but in rare cases also to a sphingoid base. A large structural heterogeneity results from differences in number, identity, linkage, and anomeric configuration of the carbohydrate residues, and also from structural differences within the hydrophobic part. GSLs form complex cell-type specific patterns, which change with the species, the cellular differentiation state, viral transformation, ontogenesis, and oncogenesis. Although GSL structures can be assigned to only a few series with a common carbohydrate core, their structural variety and the complex pattern are challenges for their elucidation and quantification by mass spectrometric techniques. We present a general overview of the application of lipidomics for GSL determination. This includes analytical procedures and instrumentation together with recent correlations of GSL molecular species with human diseases. Difficulties such as the structural complexity and the lack of standard substances for complex GSLs are discussed.

  7. Regulation of cellular communication by signaling microdomains in the blood vessel wall.

    Science.gov (United States)

    Billaud, Marie; Lohman, Alexander W; Johnstone, Scott R; Biwer, Lauren A; Mutchler, Stephanie; Isakson, Brant E

    2014-01-01

    It has become increasingly clear that the accumulation of proteins in specific regions of the plasma membrane can facilitate cellular communication. These regions, termed signaling microdomains, are found throughout the blood vessel wall where cellular communication, both within and between cell types, must be tightly regulated to maintain proper vascular function. We will define a cellular signaling microdomain and apply this definition to the plethora of means by which cellular communication has been hypothesized to occur in the blood vessel wall. To that end, we make a case for three broad areas of cellular communication where signaling microdomains could play an important role: 1) paracrine release of free radicals and gaseous molecules such as nitric oxide and reactive oxygen species; 2) role of ion channels including gap junctions and potassium channels, especially those associated with the endothelium-derived hyperpolarization mediated signaling, and lastly, 3) mechanism of exocytosis that has considerable oversight by signaling microdomains, especially those associated with the release of von Willebrand factor. When summed, we believe that it is clear that the organization and regulation of signaling microdomains is an essential component to vessel wall function.

  8. Regulation of Cellular Communication by Signaling Microdomains in the Blood Vessel Wall

    Science.gov (United States)

    Billaud, Marie; Lohman, Alexander W.; Johnstone, Scott R.; Biwer, Lauren A.; Mutchler, Stephanie; Isakson, Brant E.

    2014-01-01

    It has become increasingly clear that the accumulation of proteins in specific regions of the plasma membrane can facilitate cellular communication. These regions, termed signaling microdomains, are found throughout the blood vessel wall where cellular communication, both within and between cell types, must be tightly regulated to maintain proper vascular function. We will define a cellular signaling microdomain and apply this definition to the plethora of means by which cellular communication has been hypothesized to occur in the blood vessel wall. To that end, we make a case for three broad areas of cellular communication where signaling microdomains could play an important role: 1) paracrine release of free radicals and gaseous molecules such as nitric oxide and reactive oxygen species; 2) role of ion channels including gap junctions and potassium channels, especially those associated with the endothelium-derived hyperpolarization mediated signaling, and lastly, 3) mechanism of exocytosis that has considerable oversight by signaling microdomains, especially those associated with the release of von Willebrand factor. When summed, we believe that it is clear that the organization and regulation of signaling microdomains is an essential component to vessel wall function. PMID:24671377

  9. Microdomains in the membrane landscape shape antigen-presenting cell function.

    Science.gov (United States)

    Zuidscherwoude, Malou; de Winde, Charlotte M; Cambi, Alessandra; van Spriel, Annemiek B

    2014-02-01

    The plasma membrane of immune cells is a highly organized cell structure that is key to the initiation and regulation of innate and adaptive immune responses. It is well-established that immunoreceptors embedded in the plasma membrane have a nonrandom spatial distribution that is important for coupling to components of intracellular signaling cascades. In the last two decades, specialized membrane microdomains, including lipid rafts and TEMs, have been identified. These domains are preformed structures ("physical entities") that compartmentalize proteins, lipids, and signaling molecules into multimolecular assemblies. In APCs, different microdomains containing immunoreceptors (MHC proteins, PRRs, integrins, among others) have been reported that are imperative for efficient pathogen recognition, the formation of the immunological synapse, and subsequent T cell activation. In addition, recent work has demonstrated that tetraspanin microdomains and lipid rafts are involved in BCR signaling and B cell activation. Research into the molecular mechanisms underlying membrane domain formation is fundamental to a comprehensive understanding of membrane-proximal signaling and APC function. This review will also discuss the advances in the microscopy field for the visualization of the plasma membrane, as well as the recent progress in targeting microdomains as novel, therapeutic approach for infectious and malignant diseases.

  10. Erythrocyte and porcine intestinal glycosphingolipids recognized by F4 fimbriae of enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Coddens, Annelies; Valis, Erik; Benktander, John; Ångström, Jonas; Breimer, Michael E; Cox, Eric; Teneberg, Susann

    2011-01-01

    Enterotoxigenic F4-fimbriated Escherichia coli is associated with diarrheal disease in neonatal and postweaning pigs. The F4 fimbriae mediate attachment of the bacteria to the pig intestinal epithelium, enabling an efficient delivery of diarrhea-inducing enterotoxins to the target epithelial cells. There are three variants of F4 fimbriae designated F4ab, F4ac and F4ad, respectively, having different antigenic and adhesive properties. In the present study, the binding of isolated F4ab, F4ac and F4ad fimbriae, and F4ab/ac/ad-fimbriated E. coli, to glycosphingolipids from erythrocytes and from porcine small intestinal epithelium was examined, in order to get a comprehensive view of the F4-binding glycosphingolipids involved in F4-mediated hemagglutination and adhesion to the epithelial cells of porcine intestine. Specific interactions between the F4ab, F4ac and F4ad fimbriae and both acid and non-acid glycosphingolipids were obtained, and after isolation of binding-active glycosphingolipids and characterization by mass spectrometry and proton NMR, distinct carbohydrate binding patterns were defined for each fimbrial subtype. Two novel glycosphingolipids were isolated from chicken erythrocytes, and characterized as GalNAcα3GalNAcß3Galß4Glcß1Cer and GalNAcα3GalNAcß3Galß4GlcNAcß3Galß4Glcß1Cer. These two compounds, and lactosylceramide (Galß4Glcß1Cer) with phytosphingosine and hydroxy fatty acid, were recognized by all three variants of F4 fimbriae. No binding of the F4ad fimbriae or F4ad-fimbriated E. coli to the porcine intestinal glycosphingolipids occurred. However, for F4ab and F4ac two distinct binding patterns were observed. The F4ac fimbriae and the F4ac-expressing E. coli selectively bound to galactosylceramide (Galß1Cer) with sphingosine and hydroxy 24:0 fatty acid, while the porcine intestinal glycosphingolipids recognized by F4ab fimbriae and the F4ab-fimbriated bacteria were characterized as galactosylceramide, sulfatide (SO(3)-3Galß1Cer), sulf

  11. Tetraspanin-enriched microdomains: a functional unit in cell plasma membranes.

    Science.gov (United States)

    Yáñez-Mó, María; Barreiro, Olga; Gordon-Alonso, Mónica; Sala-Valdés, Mónica; Sánchez-Madrid, Francisco

    2009-09-01

    Membrane lipids and proteins are non-randomly distributed and are unable to diffuse freely in the plane of the membrane. This is because of multiple constraints imposed both by the cortical cytoskeleton and by the preference of lipids and proteins to cluster into diverse and specialized membrane domains, including tetraspanin-enriched microdomains, glycosylphosphatidyl inositol-linked proteins nanodomains and caveolae, among others. Recent biophysical characterization of tetraspanin-enriched microdomains suggests that they might be specially suited for the regulation of avidity of adhesion receptors and the compartmentalization of enzymatic activities. Moreover, modulation by tetraspanins of the function of adhesion receptors involved in inflammation, lymphocyte activation, cancer and pathogen infection suggests potential as therapeutic targets. This review explores this emerging picture of tetraspanin microdomains and discusses the implications for cell adhesion, proteolysis and pathogenesis.

  12. Mechanotransduction and Metabolism in Cardiomyocyte Microdomains.

    Science.gov (United States)

    Pasqualini, Francesco S; Nesmith, Alexander P; Horton, Renita E; Sheehy, Sean P; Parker, Kevin Kit

    2016-01-01

    Efficient contractions of the left ventricle are ensured by the continuous transfer of adenosine triphosphate (ATP) from energy production sites, the mitochondria, to energy utilization sites, such as ionic pumps and the force-generating sarcomeres. To minimize the impact of intracellular ATP trafficking, sarcomeres and mitochondria are closely packed together and in proximity with other ultrastructures involved in excitation-contraction coupling, such as t-tubules and sarcoplasmic reticulum junctions. This complex microdomain has been referred to as the intracellular energetic unit. Here, we review the literature in support of the notion that cardiac homeostasis and disease are emergent properties of the hierarchical organization of these units. Specifically, we will focus on pathological alterations of this microdomain that result in cardiac diseases through energy imbalance and posttranslational modifications of the cytoskeletal proteins involved in mechanosensing and transduction.

  13. MALDI-TOF and cluster-TOF-SIMS imaging of Fabry disease biomarkers

    Science.gov (United States)

    Touboul, David; Roy, Sandrine; Germain, Dominique P.; Chaminade, Pierre; Brunelle, Alain; Laprevote, Olivier

    2007-02-01

    Fabry disease is an X-linked disorder of glycosphingolipid metabolism, in which a partial or total deficiency of [alpha]-galactosidase A, a lysosomal enzyme, results in the progressive accumulation of neutral glycosphingolipids (globotriaosylceramide and digalactosylceramide) in most fluids and tissues of the body. Few information is available about the composition and distribution in tissues of the accumulated glycosphingolipids species. Mass spectrometry imaging is an innovative technique, which can provide pieces of information about the distribution of numerous biological compounds, such as lipids, directly on the tissue sections. MALDI-TOF and cluster-TOF-SIMS imaging approaches were used to study the localization of lipids (cholesterol, cholesterol sulfate, vitamin E, glycosphingolipids ...) on skin and kidney sections of patients affected by the Fabry disease. Numerous information on pathophysiology were enlightened by both techniques.

  14. Spatio-temporal remodeling of functional membrane microdomains organizes the signaling networks of a bacterium.

    Directory of Open Access Journals (Sweden)

    Johannes Schneider

    2015-04-01

    Full Text Available Lipid rafts are membrane microdomains specialized in the regulation of numerous cellular processes related to membrane organization, as diverse as signal transduction, protein sorting, membrane trafficking or pathogen invasion. It has been proposed that this functional diversity would require a heterogeneous population of raft domains with varying compositions. However, a mechanism for such diversification is not known. We recently discovered that bacterial membranes organize their signal transduction pathways in functional membrane microdomains (FMMs that are structurally and functionally similar to the eukaryotic lipid rafts. In this report, we took advantage of the tractability of the prokaryotic model Bacillus subtilis to provide evidence for the coexistence of two distinct families of FMMs in bacterial membranes, displaying a distinctive distribution of proteins specialized in different biological processes. One family of microdomains harbors the scaffolding flotillin protein FloA that selectively tethers proteins specialized in regulating cell envelope turnover and primary metabolism. A second population of microdomains containing the two scaffolding flotillins, FloA and FloT, arises exclusively at later stages of cell growth and specializes in adaptation of cells to stationary phase. Importantly, the diversification of membrane microdomains does not occur arbitrarily. We discovered that bacterial cells control the spatio-temporal remodeling of microdomains by restricting the activation of FloT expression to stationary phase. This regulation ensures a sequential assembly of functionally specialized membrane microdomains to strategically organize signaling networks at the right time during the lifespan of a bacterium.

  15. The Drosophila gene brainiac encodes a glycosyltransferase putatively involved in glycosphingolipid synthesis

    DEFF Research Database (Denmark)

    Schwientek, Tilo; Keck, Birgit; Levery, Steven B

    2002-01-01

    -linked mannose as well as beta-linked galactose as acceptor sugars. The inner disaccharide core structures of glycosphingolipids in mammals (Galbeta1-4Glcbeta1-Cer) and insects (Manbeta1-4Glcbeta1-Cer) are different. Both disaccharide glycolipids served as substrates for brainiac, but glycolipids of insect cells...... have so far only been found to be based on the GlcNAcbeta1-3Manbeta1-4Glcbeta1-Cer core structure. Infection of High Five(TM) cells with baculovirus containing full coding brainiac cDNA markedly increased the ratio of GlcNAcbeta1-3Manbeta1-4Glcbeta1-Cer glycolipids compared with Galbeta1-4Manbeta1......-4Glcbeta1-Cer found in wild type cells. We suggest that brainiac exerts its biological functions by regulating biosynthesis of glycosphingolipids....

  16. Isolation and characterization of lipid rafts in Emiliania huxleyi: a role for membrane microdomains in host-virus interactions.

    Science.gov (United States)

    Rose, Suzanne L; Fulton, James M; Brown, Christopher M; Natale, Frank; Van Mooy, Benjamin A S; Bidle, Kay D

    2014-04-01

    Coccolithoviruses employ a suite of glycosphingolipids (GSLs) to successfully infect the globally important coccolithophore Emiliania huxleyi. Lipid rafts, chemically distinct membrane lipid microdomains that are enriched in GSLs and are involved in sensing extracellular stimuli and activating signalling cascades through protein-protein interactions, likely play a fundamental role in host-virus interactions. Using combined lipidomics, proteomics and bioinformatics, we isolated and characterized the lipid and protein content of lipid rafts from control E. huxleyi cells and those infected with EhV86, the type strain for Coccolithovirus. Lipid raft-enriched fractions were isolated and purified as buoyant, detergent-resistant membranes (DRMs) in OptiPrep density gradients. Transmission electron microscopy of vesicle morphology, polymerase chain reaction amplification of the EhV major capsid protein gene and immunoreactivity to flotillin antisera served as respective physical, molecular and biochemical markers. Subsequent lipid characterization of DRMs via high performance liquid chromatography-triple quadrapole mass spectrometry revealed four distinct GSL classes. Parallel proteomic analysis confirmed flotillin as a major lipid raft protein, along with a variety of proteins affiliated with host defence, programmed cell death and innate immunity pathways. The detection of an EhV86-encoded C-type lectin-containing protein confirmed that infection occurs at the interface between lipid rafts and cellular stress/death pathways via specific GSLs and raft-associated proteins. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Structural Analysis of Unsaturated Glycosphingolipids Using Shotgun Ozone-Induced Dissociation Mass Spectrometry

    Science.gov (United States)

    Barrientos, Rodell C.; Vu, Ngoc; Zhang, Qibin

    2017-08-01

    Glycosphingolipids are essential biomolecules widely distributed across biological kingdoms yet remain relatively underexplored owing to both compositional and structural complexity. While the glycan head group has been the subject of most studies, there is paucity of reports on the lipid moiety, particularly the location of unsaturation. In this paper, ozone-induced dissociation mass spectrometry (OzID-MS) implemented in a traveling wave-based quadrupole time-of-flight (Q-ToF) mass spectrometer was applied to study unsaturated glycosphingolipids using shotgun approach. Resulting high resolution mass spectra facilitated the unambiguous identification of diagnostic OzID product ions. Using [M+Na]+ adducts of authentic standards, we observed that the long chain base and fatty acyl unsaturation had distinct reactivity with ozone. The reactivity of unsaturation in the fatty acyl chain was about 8-fold higher than that in the long chain base, which enables their straightforward differentiation. Influence of the head group, fatty acyl hydroxylation, and length of fatty acyl chain on the oxidative cleavage of double bonds was also observed. Application of this technique to bovine brain galactocerebrosides revealed co-isolated isobaric and regioisomeric species, which otherwise would be incompletely identified using contemporary collision-induced dissociation (CID) alone. These results highlight the potential of OzID-MS in glycosphingolipids research, which not only provides complementary structural information to existing CID technique but also facilitates de novo structural determination of these complex biomolecules. [Figure not available: see fulltext.

  18. Correction of Liver Steatosis by a Hydrophobic Iminosugar Modulating Glycosphingolipids Metabolism

    NARCIS (Netherlands)

    Lombardo, Elisa; van Roomen, Cindy P. A. A.; van Puijvelde, Gijs H.; Ottenhoff, Roelof; van Eijk, Marco; Aten, Jan; Kuiper, Johan; Overkleeft, Herman S.; Groen, Albert K.; Verhoeven, Arthur J.; Aerts, Johannes M. F. G.; Bietrix, Florence

    2012-01-01

    The iminosugar N-(5'-adamantane-1'-yl-methoxy)-pentyl-1-deoxynoijirimycin (AMP-DNM), an inhibitor of glycosphingolipid (GSL) biosynthesis is known to ameliorate diabetes, insulin sensitivity and to prevent liver steatosis in ob/ob mice. Thus far the effect of GSL synthesis inhibition on pre-existing

  19. Domains of increased thickness in microvillar membranes of the small intestinal enterocyte

    DEFF Research Database (Denmark)

    Kunding, Andreas H; Christensen, Sune M; Danielsen, E Michael

    2010-01-01

    The apical surface of the enterocyte is sculpted into a dense array of cylindrical microvillar protrusions by supporting actin filaments. Membrane microdomains (rafts) enriched in cholesterol and glycosphingolipids comprise roughly 50% of the microvillar membrane and play a vital role in orchestr......The apical surface of the enterocyte is sculpted into a dense array of cylindrical microvillar protrusions by supporting actin filaments. Membrane microdomains (rafts) enriched in cholesterol and glycosphingolipids comprise roughly 50% of the microvillar membrane and play a vital role...... in orchestrating absorptive/digestive action of dietary nutrients at this important cellular interface. Increased membrane thickness is believed to be a morphological characteristic of rafts. Thus, we investigated whether the high contents of lipid rafts in the microvillar membrane is reflected in local variations...... was clearly monophasic. The encountered domains of increased thickness (DITs) occupied 48% of the microvillar membrane and from the data we estimated the area of a single DIT to have a lower limit of 600 nm(2). In other experiments we mapped the organization of biochemically defined lipid rafts by immunogold...

  20. Lipid composition of microdomains is altered in neuronopathic Gaucher disease sheep brain and spleen.

    Science.gov (United States)

    Hein, Leanne K; Rozaklis, Tina; Adams, Melissa K; Hopwood, John J; Karageorgos, Litsa

    2017-07-01

    Gaucher disease is a lysosomal storage disorder caused by a deficiency in glucocerebrosidase activity that leads to accumulation of glucosylceramide and glucosylsphingosine. Membrane raft microdomains are discrete, highly organized microdomains with a unique lipid composition that provide the necessary environment for specific protein-lipid and protein-protein interactions to take place. In this study we purified detergent resistant membranes (DRM; membrane rafts) from the occipital cortex and spleen from sheep affected with acute neuronopathic Gaucher disease and wild-type controls. We observed significant increases in the concentrations of glucosylceramide, hexosylsphingosine, BMP and gangliosides and decreases in the percentage of cholesterol and phosphatidylcholine leading to an altered DRM composition. Altered sphingolipid/cholesterol homeostasis would dramatically disrupt DRM architecture making them less ordered and more fluid. In addition, significant changes in the length and degree of lipid saturation within the DRM microdomains in the Gaucher brain were also observed. As these DRM microdomains are involved in many cellular events, an imbalance or disruption of the cell membrane homeostasis may impair normal cell function. This disruption of membrane raft microdomains and imbalance within the environment of cellular membranes of neuronal cells may be a key factor in initiating a cascade process leading to neurodegeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Single-molecule tracking studies of flow-induced microdomain alignment in cylinder-forming polystyrene-poly(ethylene oxide) diblock copolymer films.

    Science.gov (United States)

    Tran-Ba, Khanh-Hoa; Higgins, Daniel A; Ito, Takashi

    2014-09-25

    Flow-based approaches are promising routes to preparation of aligned block copolymer microdomains within confined spaces. An in-depth characterization of such nanoscale morphologies within macroscopically nonuniform materials under ambient conditions is, however, often challenging. In this study, single-molecule tracking (SMT) methods were employed to probe the flow-induced alignment of cylindrical microdomains (ca. 22 nm in diameter) in polystyrene-poly(ethylene oxide) diblock copolymer (PS-b-PEO) films. Films of micrometer-scale thicknesses were prepared by overlaying a benzene solution droplet on a glass coverslip with a rectangular glass plate, followed by solvent evaporation under a nitrogen atmosphere. The microdomain alignment was quantitatively assessed from SMT data exhibiting the diffusional motions of individual sulforhodamine B fluorescent probes that preferentially partitioned into cylindrical PEO microdomains. Better overall microdomain orientation along the flow direction was observed near the substrate interface in films prepared at a higher flow rate, suggesting that the microdomain alignment was primarily induced by shear flow. The SMT data also revealed the presence of micrometer-scale grains consisting of highly ordered microdomains with coherent orientation. The results of this study provide insights into shear-based preparation of aligned cylindrical microdomains in block copolymer films from solutions within confined spaces.

  2. Transmembrane voltage: Potential to induce lateral microdomains.

    Czech Academy of Sciences Publication Activity Database

    Malínský, Jan; Tanner, W.; Opekarová, Miroslava

    2016-01-01

    Roč. 1861, č. 8 (2016), s. 806-811 ISSN 1388-1981 R&D Projects: GA ČR(CZ) GA15-10641S Institutional support: RVO:68378041 Keywords : membrane microdomain * membrane potential * fluorescence spectroscopy * membrane structure * fluorescence microscopy Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.547, year: 2016

  3. Fluorescent probes for detecting cholesterol-rich ordered membrane microdomains: entangled relationships between structural analogies in the membrane and functional homologies in the cell

    Directory of Open Access Journals (Sweden)

    Gérald Gaibelet

    2017-02-01

    Full Text Available This review addresses the question of fluorescent detection of ordered membrane (micro domains in living (cultured cells, with a “practical” point of view since the situation is much more complicated than for studying model membranes. We first briefly recall the bases of model membrane structural organization involving liquid-ordered and -disordered phases, and the main features of their counterparts in cell membranes that are the various microdomains. We then emphasize the utility of the fluorescent probes derived from cholesterol, and delineate the respective advantages, limitations and drawbacks of the existing ones. In particular, besides their intra-membrane behavior, their relevant characteristics should integrate their different cellular fates for membrane turn-over, trafficking and metabolism, in order to evaluate and improve their efficiency for in-situ probing membrane microdomains in the cell physiology context. Finally, at the present stage, it appears that Bdp-Chol and Pyr-met-Chol display well complementary properties, allowing to use them in combination to improve the reliability of the current experimental approaches. But the field is still open, and there remains much work to perform in this research area.

  4. Distinct metamorphic evolution of alternating silica-saturated and silica-deficient microdomains within garnet in ultrahigh-temperature granulites: An example from Sri Lanka

    Directory of Open Access Journals (Sweden)

    P.L. Dharmapriya

    2017-09-01

    Full Text Available Here we report the occurrence of garnet porphyroblasts that have overgrown alternating silica-saturated and silica deficient microdomains via different mineral reactions. The samples were collected from ultrahigh-temperature (UHT metapelites in the Highland Complex, Sri Lanka. In some of the metapelites, garnet crystals have cores formed via a dehydration reaction, which had taken place at silica-saturated microdomains and mantle to rim areas formed via a dehydration reaction at silica-deficient microdomains. In contrast, some other garnets in the same rock cores had formed via a dehydration reaction which occurred at silica-deficient microdomains while mantle to rim areas formed via a dehydration reaction at silica-saturated microdomains. Based on the textural observations, we conclude that the studied garnets have grown across different effective bulk compositional microdomains during the prograde evolution. These microdomains could represent heterogeneous compositional layers (paleobedding/laminations in the precursor sediments or differentiated crenulation cleavages that existed during prograde metamorphism. UHT metamorphism associated with strong ductile deformation, metamorphic differentiation and crystallization of locally produced melt may have obliterated the evidence for such microdomains in the matrix. The lack of significant compositional zoning in garnet probably due to self-diffusion during UHT metamorphism had left mineral inclusions as the sole evidence for earlier microdomains with contrasting chemistry.

  5. Drosophila egghead encodes a beta 1,4-mannosyltransferase predicted to form the immediate precursor glycosphingolipid substrate for brainiac

    DEFF Research Database (Denmark)

    Wandall, Hans H; Pedersen, Johannes W; Park, Chaeho

    2002-01-01

    -N-acetylglucosamine:beta Man beta 1,3-N-acetylglucosaminyltransferase (beta 3GlcNAc-transferase) tentatively assigned a key role in biosynthesis of arthroseries glycosphingolipids and forming the trihexosylceramide, GlcNAc beta 1-3Man beta 1-4Glc beta 1-1Cer. In the present study we demonstrate that egghead encodes a Golgi......-located GDP-mannose:beta Glc beta 1,4-mannosyltransferase tentatively assigned a biosynthetic role to form the precursor arthroseries glycosphingolipid substrate for Brainiac, Man beta 1-4Glc beta 1-1Cer. Egghead is unique among eukaryotic glycosyltransferase genes in that homologous genes are limited...

  6. Single-Molecule Tracking Study of the Permeability and Transverse Width of Individual Cylindrical Microdomains in Solvent-Swollen Polystyrene-block-poly(ethylene oxide) Films.

    Science.gov (United States)

    Sapkota, Dol Raj; Tran-Ba, Khanh-Hoa; Elwell-Cuddy, Trevor; Higgins, Daniel A; Ito, Takashi

    2016-12-01

    Understanding the properties of solvent-swollen block copolymer (BCP) microdomains is important for better solvent-based control of microdomain morphology, orientation, and permeability. In this study, single-molecule tracking (SMT) was explored to assess the permeability and transverse width of individual cylindrical microdomains in solvent-swollen polystyrene-block-poly(ethylene oxide) (PS-b-PEO) films. PS-b-PEO films comprising shear-elongated cylindrical PEO microdomains were prepared by sandwiching its benzene or tetrahydrofuran (THF) solution between two glass substrates. SMT measurements were performed at different drying times to investigate the effects of solvent evaporation on the microdomain properties. SMT data showed one-dimensional (1D) motions of single fluorescent molecules (sulforhodamine B) based on their diffusion within the cylindrical microdomains. Microdomain permeability and transverse width were assessed from the single-molecule diffusion coefficients (D SMT ) and transverse variance of the 1D trajectories (σ δ 2 ), respectively. The D SMT and σ δ 2 values from individual 1D trajectories were widely distributed with no evidence of correlation on a single molecule basis, possibly because the individual microdomains in a film were swollen to different extents. On average, microdomain permeability (D) and effective radius (r) gradually decreased within the first 3 days of drying due to solvent evaporation, and changed negligibly thereafter. PS-b-PEO films prepared from THF solutions exhibited larger changes in D and r as compared with those from benzene solutions due to the better swelling of the PEO microdomains by THF. Importantly, changes in D were more prominent than those in r, suggesting that the permeability of the PEO microdomains is very susceptible to the presence of solvent. These results reveal the unique capability of SMT to assess the properties of individual cylindrical microdomains in a solvent-swollen BCP film.

  7. Annexins as organizers of cholesterol- and sphingomyelin-enriched membrane microdomains in Niemann-Pick type C disease.

    Science.gov (United States)

    Domon, Magdalena; Nasir, Mehmet Nail; Matar, Gladys; Pikula, Slawomir; Besson, Françoise; Bandorowicz-Pikula, Joanna

    2012-06-01

    Growing evidence suggests that membrane microdomains enriched in cholesterol and sphingomyelin are sites for numerous cellular processes, including signaling, vesicular transport, interaction with pathogens, and viral infection, etc. Recently some members of the annexin family of conserved calcium and membrane-binding proteins have been recognized as cholesterol-interacting molecules and suggested to play a role in the formation, stabilization, and dynamics of membrane microdomains to affect membrane lateral organization and to attract other proteins and signaling molecules onto their territory. Furthermore, annexins were implicated in the interactions between cytosolic and membrane molecules, in the turnover and storage of cholesterol and in various signaling pathways. In this review, we focus on the mechanisms of interaction of annexins with lipid microdomains and the role of annexins in membrane microdomains dynamics including possible participation of the domain-associated forms of annexins in the etiology of human lysosomal storage disease called Niemann-Pick type C disease, related to the abnormal storage of cholesterol in the lysosome-like intracellular compartment. The involvement of annexins and cholesterol/sphingomyelin-enriched membrane microdomains in other pathologies including cardiac dysfunctions, neurodegenerative diseases, obesity, diabetes mellitus, and cancer is likely, but is not supported by substantial experimental observations, and therefore awaits further clarification.

  8. Glycosphingolipids with extended sugar chain have specialized functions in development and behavior of Drosophila

    DEFF Research Database (Denmark)

    Chen, Ya-Wen; Pedersen, Johannes W; Wandall, Hans H

    2007-01-01

    Glycosphingolipids (GSL) are glycosylated polar lipids in cell membranes essential for development of vertebrates as well as Drosophila. Mutants that impair enzymes involved in biosynthesis of GSL sugar chains provide a means to assess the functions of the sugar chains in vivo. The Drosophila gly...

  9. Unraveling the role of membrane microdomains during microbial infections.

    Science.gov (United States)

    Bagam, Prathyusha; Singh, Dhirendra P; Inda, Maria Eugenia; Batra, Sanjay

    2017-10-01

    Infectious diseases pose major socioeconomic and health-related threats to millions of people across the globe. Strategies to combat infectious diseases derive from our understanding of the complex interactions between the host and specific bacterial, viral, and fungal pathogens. Lipid rafts are membrane microdomains that play important role in life cycle of microbes. Interaction of microbial pathogens with host membrane rafts influences not only their initial colonization but also their spread and the induction of inflammation. Therefore, intervention strategies aimed at modulating the assembly of membrane rafts and/or regulating raft-directed signaling pathways are attractive approaches for the. management of infectious diseases. The current review discusses the latest advances in terms of techniques used to study the role of membrane microdomains in various pathological conditions and provides updated information regarding the role of membrane rafts during bacterial, viral and fungal infections.

  10. Nuclear Lipid Microdomain as Place of Interaction between Sphingomyelin and DNA during Liver Regeneration

    Directory of Open Access Journals (Sweden)

    Samuela Cataldi

    2013-03-01

    Full Text Available Nuclear sphingomyelin is a key molecule for cell proliferation. This molecule is organized with cholesterol and proteins to form specific lipid microdomains bound to the inner nuclear membrane where RNA is synthesized. Here, we have reported the ability of the sphingomyelin present in the nuclear microdomain to bind DNA and regulate its synthesis, and to highlight its role in cell proliferation induced by partial hepatectomy. During G1/S transition of the cell cycle, sphingomyelin and DNA content is very high and it is strongly reduced after exogenous sphingomyelinase treatment. During the S-phase of the cell cycle, the stimulation of sphingomyelinase and inhibition of sphingomyelin–synthase are accompanied by the DNA synthesis start. To assess the specificity of the results, experiments were repeated with trifluoperazine, a drug known to affect the synthesis of lipids and DNA and to stimulate sphingomyelinase activity. The activity of sphingomyelinase is stimulated in the first hour after hepatectomy and sphingomyelin–DNA synthesis is strongly attenuated. It may be hypothesized that the nuclear microdomain represents a specific area of the inner nuclear membrane that acts as an active site of chromatin anchorage thanks to the stabilizing action of sphingomyelin. Thus, sphingomyelin metabolism in nuclear lipid microdomains is suggested to regulate cell proliferation.

  11. Deep-apical tubules: dynamic lipid-raft microdomains in the brush-border region of enterocytes

    DEFF Research Database (Denmark)

    Hansen, Gert H; Pedersen, Jens; Niels-Christiansen, Lise-Lotte

    2003-01-01

    microdomains. Deep-apical tubules were positioned close to the actin rootlets of adjacent microvilli in the terminal web region, which had a diameter of 50-100 nm, and penetrated up to 1 microm into the cytoplasm. Markers for transcytosis, IgA and the polymeric immunoglobulin receptor, as well as the resident...... lipid raft-containing compartments, but little is otherwise known about these raft microdomains. We therefore studied in closer detail apical lipid-raft compartments in enterocytes by immunogold electron microscopy and biochemical analyses. Novel membrane structures, deep-apical tubules, were visualized...... brush-border enzyme aminopeptidase N, were present in these deep-apical tubules. We propose that deep-apical tubules are a specialized lipid-raft microdomain in the brush-border region functioning as a hub in membrane trafficking at the brush border. In addition, the sensitivity to cholesterol depletion...

  12. Cell surface topology creates high Ca2+ signalling microdomains

    DEFF Research Database (Denmark)

    Brasen, Jens Christian; Olsen, Lars Folke; Hallett, Maurice B

    2010-01-01

    It has long been speculated that cellular microdomains are important for many cellular processes, especially those involving Ca2+ signalling. Measurements of cytosolic Ca2+ report maximum concentrations of less than few micromolar, yet several cytosolic enzymes require concentrations of more than...

  13. Depolarization affects lateral microdomain structure of yeast plasma membrane

    Czech Academy of Sciences Publication Activity Database

    Herman, P.; Večeř, J.; Opekarová, Miroslava; Veselá, Petra; Jančíková, I.; Zahumenský, J.; Malínský, Jan

    2015-01-01

    Roč. 282, č. 3 (2015), s. 419-434 ISSN 1742-464X R&D Projects: GA ČR GAP205/12/0720 Institutional support: RVO:68378041 Keywords : gel microdomains * lipid order * transmembrane potential Subject RIV: EA - Cell Biology Impact factor: 4.237, year: 2015

  14. N-3 fatty acids and membrane microdomains: from model membranes to lymphocyte function.

    Science.gov (United States)

    Shaikh, Saame Raza; Teague, Heather

    2012-12-01

    This article summarizes the author's research on fish oil derived n-3 fatty acids, plasma membrane organization and B cell function. We first cover basic model membrane studies that investigated how docosahexaenoic acid (DHA) targeted the organization of sphingolipid-cholesterol enriched lipid microdomains. A key finding here was that DHA had a relatively poor affinity for cholesterol. This work led to a model that predicted DHA acyl chains in cells would manipulate lipid-protein microdomain organization and thereby function. We then review how the predictions of the model were tested with B cells in vitro followed by experiments using mice fed fish oil. These studies reveal a highly complex picture on how n-3 fatty acids target lipid-protein organization and B cell function. Key findings are as follows: (1) n-3 fatty acids target not just the plasma membrane but also endomembrane organization; (2) DHA, but not eicosapentaenoic acid (EPA), disrupts microdomain spatial distribution (i.e. clustering), (3) DHA alters protein lateral organization and (4) changes in membrane organization are accompanied by functional effects on both innate and adaptive B cell function. Altogether, the research over the past 10 years has led to an evolution of the original model on how DHA reorganizes membrane microdomains. The work raises the intriguing possibility of testing the model at the human level to target health and disease. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Investigation of cAMP microdomains as a path to novel cancer diagnostics.

    Science.gov (United States)

    Desman, Garrett; Waintraub, Caren; Zippin, Jonathan H

    2014-12-01

    Understanding of cAMP signaling has greatly improved over the past decade. The advent of live cell imaging techniques and more specific pharmacologic modulators has led to an improved understanding of the intricacies by which cAMP is able to modulate such a wide variety of cellular pathways. It is now appreciated that cAMP is able to activate multiple effector proteins at distinct areas in the cell leading to the activation of very different downstream targets. The investigation of signaling proteins in cancer is a common route to the development of diagnostic tools, prognostic tools, and/or therapeutic targets, and in this review we highlight how investigation of cAMP signaling microdomains driven by the soluble adenylyl cyclase in different cancers has led to the development of a novel cancer biomarker. Antibodies directed against the soluble adenylyl cyclase (sAC) are highly specific markers for melanoma especially for lentigo maligna melanoma and are being described as "second generation" cancer diagnostics, which are diagnostics that determine the 'state' of a cell and not just identify the cell type. Due to the wide presence of cAMP signaling pathways in cancer, we predict that further investigation of both sAC and other cAMP microdomains will lead to additional cancer biomarkers. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Lipid rafts and B cell signaling.

    Science.gov (United States)

    Gupta, Neetu; DeFranco, Anthony L

    2007-10-01

    B cells comprise an essential component of the humoral immune system. They are equipped with the unique ability to synthesize and secrete pathogen-neutralizing antibodies, and share with professional antigen presenting cells the ability to internalize foreign antigens, and process them for presentation to helper T cells. Recent evidence indicates that specialized cholesterol- and glycosphingolipid-rich microdomains in the plasma membrane commonly referred to as lipid rafts, serve to compartmentalize key signaling molecules during the different stages of B cell activation including B cell antigen receptor (BCR)-initiated signal transduction, endocytosis of BCR-antigen complexes, loading of antigenic peptides onto MHC class II molecules, MHC-II associated antigen presentation to helper T cells, and receipt of helper signals via the CD40 receptor. Here we review the recent literature arguing for a role of lipid rafts in the spatial organization of B cell function.

  17. Microdomain-forming proteins and the role of the reggies/flotillins during axon regeneration in zebrafish

    OpenAIRE

    Stürmer, Claudia

    2011-01-01

    The two proteins reggie-1 and reggie-2 (flotillins) were identified in axon-regenerating neurons in the central nervous system and shown to be essential for neurite growth and regeneration in fish and mammals. Reggies/flotillins are microdomain scaffolding proteins sharing biochemical properties with lipid raft molecules, form clusters at the cytoplasmic face of the plasma membrane and interact with signaling molecules in a cell type specific manner. In this review, reggie microdomains, lipid...

  18. Human Immunodeficiency Virus Type 1 Nef protein modulates the lipid composition of virions and host cell membrane microdomains

    Directory of Open Access Journals (Sweden)

    Geyer Matthias

    2007-10-01

    Full Text Available Abstract Background The Nef protein of Human Immunodeficiency Viruses optimizes viral spread in the infected host by manipulating cellular transport and signal transduction machineries. Nef also boosts the infectivity of HIV particles by an unknown mechanism. Recent studies suggested a correlation between the association of Nef with lipid raft microdomains and its positive effects on virion infectivity. Furthermore, the lipidome analysis of HIV-1 particles revealed a marked enrichment of classical raft lipids and thus identified HIV-1 virions as an example for naturally occurring membrane microdomains. Since Nef modulates the protein composition and function of membrane microdomains we tested here if Nef also has the propensity to alter microdomain lipid composition. Results Quantitative mass spectrometric lipidome analysis of highly purified HIV-1 particles revealed that the presence of Nef during virus production from T lymphocytes enforced their raft character via a significant reduction of polyunsaturated phosphatidylcholine species and a specific enrichment of sphingomyelin. In contrast, Nef did not significantly affect virion levels of phosphoglycerolipids or cholesterol. The observed alterations in virion lipid composition were insufficient to mediate Nef's effect on particle infectivity and Nef augmented virion infectivity independently of whether virus entry was targeted to or excluded from membrane microdomains. However, altered lipid compositions similar to those observed in virions were also detected in detergent-resistant membrane preparations of virus producing cells. Conclusion Nef alters not only the proteome but also the lipid composition of host cell microdomains. This novel activity represents a previously unrecognized mechanism by which Nef could manipulate HIV-1 target cells to facilitate virus propagation in vivo.

  19. Membrane Microdomain Structures of Liposomes and Their Contribution to the Cellular Uptake Efficiency into HeLa Cells.

    Science.gov (United States)

    Onuki, Yoshinori; Obata, Yasuko; Kawano, Kumi; Sano, Hiromu; Matsumoto, Reina; Hayashi, Yoshihiro; Takayama, Kozo

    2016-02-01

    The purpose of this study is to obtain a comprehensive relationship between membrane microdomain structures of liposomes and their cellular uptake efficiency. Model liposomes consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/cholesterol (Ch) were prepared with various lipid compositions. To detect distinct membrane microdomains in the liposomes, fluorescence-quenching assays were performed at temperatures ranging from 25 to 60 °C using 1,6-diphenyl-1,3,5-hexatriene-labeled liposomes and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl. From the data analysis using the response surface method, we gained a better understanding of the conditions for forming distinct domains (Lo, Ld, and gel phase membranes) as a function of lipid composition. We further performed self-organizing maps (SOM) clustering to simplify the complicated behavior of the domain formation to obtain its essence. As a result, DPPC/DOPC/Ch liposomes in any lipid composition were integrated into five distinct clusters in terms of similarity of the domain structure. In addition, the findings from synchrotron small-angle X-ray scattering analysis offered further insight into the domain structures. As a last phase of this study, an in vitro cellular uptake study using HeLa cells was conducted using SOM clusters' liposomes with/without PEGylation. As a consequence of this study, higher cellular uptake was observed from liposomes having Ch-rich ordered domains.

  20. Nanosecond pulsed electric field (nsPEF) enhance cytotoxicity of cisplatin to hepatocellular cells by microdomain disruption on plasma membrane.

    Science.gov (United States)

    Yin, Shengyong; Chen, Xinhua; Xie, Haiyang; Zhou, Lin; Guo, Danjing; Xu, Yuning; Wu, Liming; Zheng, Shusen

    2016-08-15

    Previous studies showed nanosecond pulsed electric field (nsPEF) can ablate solid tumors including hepatocellular carcinoma (HCC) but its effect on cell membrane is not fully understood. We hypothesized nsPEF disrupt the microdomains on outer-cellular membrane with direct mechanical force and as a result the plasma membrane permeability increases to facilitate the small molecule intake. Three HCC cells were pulsed one pulse per minute, an interval longer than nanopore resealing time. The cationized ferritin was used to mark up the electronegative microdomains, propidium iodide (PI) for membrane permeabilization, energy dispersive X-ray spectroscopy (EDS) for the negative cell surface charge and cisplatin for inner-cellular cytotoxicity. We demonstrated that the ferritin marked-microdomain and negative cell surface charge were disrupted by nsPEF caused-mechanical force. The cell uptake of propidium and cytotoxicity of DNA-targeted cisplatin increased with a dose effect. Cisplatin gains its maximum inner-cellular cytotoxicity when combining with nsPEF stimulation. We conclude that nsPEF disrupt the microdomains on the outer cellular membrane directly and increase the membrane permeabilization for PI and cisplatin. The microdomain disruption and membrane infiltration changes are caused by the mechanical force from the changes of negative cell surface charge. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Nanosecond pulsed electric field (nsPEF) enhance cytotoxicity of cisplatin to hepatocellular cells by microdomain disruption on plasma membrane

    International Nuclear Information System (INIS)

    Yin, Shengyong; Chen, Xinhua; Xie, Haiyang; Zhou, Lin; Guo, Danjing; Xu, Yuning; Wu, Liming; Zheng, Shusen

    2016-01-01

    Previous studies showed nanosecond pulsed electric field (nsPEF) can ablate solid tumors including hepatocellular carcinoma (HCC) but its effect on cell membrane is not fully understood. We hypothesized nsPEF disrupt the microdomains on outer-cellular membrane with direct mechanical force and as a result the plasma membrane permeability increases to facilitate the small molecule intake. Three HCC cells were pulsed one pulse per minute, an interval longer than nanopore resealing time. The cationized ferritin was used to mark up the electronegative microdomains, propidium iodide (PI) for membrane permeabilization, energy dispersive X-ray spectroscopy (EDS) for the negative cell surface charge and cisplatin for inner-cellular cytotoxicity. We demonstrated that the ferritin marked-microdomain and negative cell surface charge were disrupted by nsPEF caused-mechanical force. The cell uptake of propidium and cytotoxicity of DNA-targeted cisplatin increased with a dose effect. Cisplatin gains its maximum inner-cellular cytotoxicity when combining with nsPEF stimulation. We conclude that nsPEF disrupt the microdomains on the outer cellular membrane directly and increase the membrane permeabilization for PI and cisplatin. The microdomain disruption and membrane infiltration changes are caused by the mechanical force from the changes of negative cell surface charge.

  2. Nanosecond pulsed electric field (nsPEF) enhance cytotoxicity of cisplatin to hepatocellular cells by microdomain disruption on plasma membrane

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Shengyong; Chen, Xinhua; Xie, Haiyang; Zhou, Lin [Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou (China); Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003 (China); Guo, Danjing; Xu, Yuning [Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003 (China); Wu, Liming, E-mail: wlm@zju.edu.cn [Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou (China); Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003 (China); Zheng, Shusen, E-mail: shusenzheng@zju.edu.cn [Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, 310003 Hangzhou (China); Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health and Key Laboratory of Organ Transplantation of Zhejiang Province, The Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou 310003 (China)

    2016-08-15

    Previous studies showed nanosecond pulsed electric field (nsPEF) can ablate solid tumors including hepatocellular carcinoma (HCC) but its effect on cell membrane is not fully understood. We hypothesized nsPEF disrupt the microdomains on outer-cellular membrane with direct mechanical force and as a result the plasma membrane permeability increases to facilitate the small molecule intake. Three HCC cells were pulsed one pulse per minute, an interval longer than nanopore resealing time. The cationized ferritin was used to mark up the electronegative microdomains, propidium iodide (PI) for membrane permeabilization, energy dispersive X-ray spectroscopy (EDS) for the negative cell surface charge and cisplatin for inner-cellular cytotoxicity. We demonstrated that the ferritin marked-microdomain and negative cell surface charge were disrupted by nsPEF caused-mechanical force. The cell uptake of propidium and cytotoxicity of DNA-targeted cisplatin increased with a dose effect. Cisplatin gains its maximum inner-cellular cytotoxicity when combining with nsPEF stimulation. We conclude that nsPEF disrupt the microdomains on the outer cellular membrane directly and increase the membrane permeabilization for PI and cisplatin. The microdomain disruption and membrane infiltration changes are caused by the mechanical force from the changes of negative cell surface charge.

  3. Membrane microdomains and the cytoskeleton constrain AtHIR1 dynamics and facilitate the formation of an AtHIR1-associated immune complex.

    Science.gov (United States)

    Lv, Xueqin; Jing, Yanping; Xiao, Jianwei; Zhang, Yongdeng; Zhu, Yingfang; Julian, Russell; Lin, Jinxing

    2017-04-01

    Arabidopsis hypersensitive-induced reaction (AtHIR) proteins function in plant innate immunity. However, the underlying mechanisms by which AtHIRs participate in plant immunity remain elusive. Here, using VA-TIRFM and FLIM-FRET, we revealed that AtHIR1 is present in membrane microdomains and co-localizes with the membrane microdomain marker REM1.3. Single-particle tracking analysis revealed that membrane microdomains and the cytoskeleton, especially microtubules, restrict the lateral mobility of AtHIR1 at the plasma membrane and facilitate its oligomerization. Furthermore, protein proximity index measurements, fluorescence cross-correlation spectroscopy, and biochemical experiments demonstrated that the formation of the AtHIR1 complex upon pathogen perception requires intact microdomains and cytoskeleton. Taken together, these findings suggest that microdomains and the cytoskeleton constrain AtHIR1 dynamics, promote AtHIR1 oligomerization, and increase the efficiency of the interactions of AtHIR1 with components of the AtHIR1 complex in response to pathogens, thus providing valuable insight into the mechanisms of defense-related responses in plants. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  4. Cholesterol modulates CFTR confinement in the plasma membrane of primary epithelial cells.

    Science.gov (United States)

    Abu-Arish, Asmahan; Pandzic, Elvis; Goepp, Julie; Matthes, Elizabeth; Hanrahan, John W; Wiseman, Paul W

    2015-07-07

    The cystic fibrosis transmembrane conductance regulator (CFTR) is a plasma-membrane anion channel that, when mutated, causes the disease cystic fibrosis. Although CFTR has been detected in a detergent-resistant membrane fraction prepared from airway epithelial cells, suggesting that it may partition into cholesterol-rich membrane microdomains (lipid rafts), its compartmentalization has not been demonstrated in intact cells and the influence of microdomains on CFTR lateral mobility is unknown. We used live-cell imaging, spatial image correlation spectroscopy, and k-space image correlation spectroscopy to examine the aggregation state of CFTR and its dynamics both within and outside microdomains in the plasma membrane of primary human bronchial epithelial cells. These studies were also performed during treatments that augment or deplete membrane cholesterol. We found two populations of CFTR molecules that were distinguishable based on their dynamics at the cell surface. One population showed confinement and had slow dynamics that were highly cholesterol dependent. The other, more abundant population was less confined and diffused more rapidly. Treatments that deplete the membrane of cholesterol caused the confined fraction and average number of CFTR molecules per cluster to decrease. Elevating cholesterol had the opposite effect, increasing channel aggregation and the fraction of channels displaying confinement, consistent with CFTR recruitment into cholesterol-rich microdomains with dimensions below the optical resolution limit. Viral infection caused the nanoscale microdomains to fuse into large platforms and reduced CFTR mobility. To our knowledge, these results provide the first biophysical evidence for multiple CFTR populations and have implications for regulation of their surface expression and channel function. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  5. Glycosphingolipid analysis in a naturally occurring ovine model of acute neuronopathic Gaucher disease.

    Science.gov (United States)

    Karageorgos, Litsa; Hein, Leanne; Rozaklis, Tina; Adams, Melissa; Duplock, Stephen; Snel, Marten; Hemsley, Kim; Kuchel, Tim; Smith, Nicholas; Hopwood, John J

    2016-07-01

    Gaucher disease arises from mutations in the β-glucocerebrosidase gene which encodes an enzyme required for the lysosomal catabolism of glucosylceramide. We have identified a naturally occurring mutation in the β-glucocerebrosidase gene in sheep that leads to Gaucher disease with acute neurological symptoms. Here we have examined the clinical phenotype at birth and subsequently quantified lipids in Gaucher lamb brain, in order to characterise the disorder. Enzyme activity assessments showed that a reduction in β-glucocerebrosidase activity to 1-5% of wild-type occurs consistently across newborn Gaucher lamb brain regions. We analyzed glucosylceramide, glucosylsphingosine, bis(monoacylglycero)phosphate and ganglioside profiles in brain, liver, and spleen, and observed 30- to 130-fold higher glucosylceramide, and 500- to 2000-fold higher glucosylsphingosine concentrations in Gaucher diseased lambs compared to wild-type. Significant increases of bis(monoacylglycero)phosphate and gangliosides [GM1, GM2, GM3] concentrations were also detected in the brain. As these glycosphingolipids are involved in many cellular events, an imbalance or disruption of the cell membrane lipid homeostasis would be expected to impair normal neuronal function. To our knowledge, this is the first detailed analysis of glycosphingolipids in various brain regions in a large animal model of neuronal disease, which permits the mechanistic investigation of lipid deregulation and their contribution to neurodegenerative process. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. The roles of membrane microdomains (rafts) in T cell activation

    Czech Academy of Sciences Publication Activity Database

    Hořejší, Václav

    2003-01-01

    Roč. 191, - (2003), s. 148-164 ISSN 0105-2896 R&D Projects: GA MŠk LN00A026 Grant - others:Wellcome Trust(GB) J1116W24Z Institutional research plan: CEZ:AV0Z5052915 Keywords : membrane microdomain * raft * T cell Subject RIV: EC - Immunology Impact factor: 7.052, year: 2003

  7. Gag induces the coalescence of clustered lipid rafts and tetraspanin-enriched microdomains at HIV-1 assembly sites on the plasma membrane.

    Science.gov (United States)

    Hogue, Ian B; Grover, Jonathan R; Soheilian, Ferri; Nagashima, Kunio; Ono, Akira

    2011-10-01

    The HIV-1 structural protein Gag associates with two types of plasma membrane microdomains, lipid rafts and tetraspanin-enriched microdomains (TEMs), both of which have been proposed to be platforms for HIV-1 assembly. However, a variety of studies have demonstrated that lipid rafts and TEMs are distinct microdomains in the absence of HIV-1 infection. To measure the impact of Gag on microdomain behaviors, we took advantage of two assays: an antibody-mediated copatching assay and a Förster resonance energy transfer (FRET) assay that measures the clustering of microdomain markers in live cells without antibody-mediated patching. We found that lipid rafts and TEMs copatched and clustered to a greater extent in the presence of membrane-bound Gag in both assays, suggesting that Gag induces the coalescence of lipid rafts and TEMs. Substitutions in membrane binding motifs of Gag revealed that, while Gag membrane binding is necessary to induce coalescence of lipid rafts and TEMs, either acylation of Gag or binding of phosphatidylinositol-(4,5)-bisphosphate is sufficient. Finally, a Gag derivative that is defective in inducing membrane curvature appeared less able to induce lipid raft and TEM coalescence. A higher-resolution analysis of assembly sites by correlative fluorescence and scanning electron microscopy showed that coalescence of clustered lipid rafts and TEMs occurs predominantly at completed cell surface virus-like particles, whereas a transmembrane raft marker protein appeared to associate with punctate Gag fluorescence even in the absence of cell surface particles. Together, these results suggest that different membrane microdomain components are recruited in a stepwise manner during assembly.

  8. Analysis of fluorescently labeled glycosphingolipid-derived oligosaccharides following ceramide glycanase digestion and anthranilic acid labeling.

    Science.gov (United States)

    Neville, David C A; Coquard, Virginie; Priestman, David A; te Vruchte, Danielle J M; Sillence, Daniel J; Dwek, Raymond A; Platt, Frances M; Butters, Terry D

    2004-08-15

    Interest in cellular glycosphingolipid (GSL) function has necessitated the development of a rapid and sensitive method to both analyze and characterize the full complement of structures present in various cells and tissues. An optimized method to characterize oligosaccharides released from glycosphingolipids following ceramide glycanase digestion has been developed. The procedure uses the fluorescent compound anthranilic acid (2-aminobenzoic acid; 2-AA) to label oligosaccharides prior to analysis using normal-phase high-performance liquid chromatography. The labeling procedure is rapid, selective, and easy to perform and is based on the published method of Anumula and Dhume [Glycobiology 8 (1998) 685], originally used to analyze N-linked oligosaccharides. It is less time consuming than a previously published 2-aminobenzamide labeling method [Anal. Biochem. 298 (2001) 207] for analyzing GSL-derived oligosaccharides, as the fluorescent labeling is performed on the enzyme reaction mixture. The purification of 2-AA-labeled products has been improved to ensure recovery of oligosaccharides containing one to four monosaccharide units, which was not previously possible using the Anumula and Dhume post-derivatization purification procedure. This new approach may also be used to analyze both N- and O-linked oligosaccharides.

  9. [Screening of phosphoprotein associated with glycosphingolipid microdomains 1 (PAG1) by cDNA microarray and influence of overexpression of PAG1 on biologic behavior of human metastatic prostatic cancer cell line in vitro].

    Science.gov (United States)

    Yu, Wen-juan; Wang, Yue-wei; Xie, Zhi-gang; You, Jiang-feng; Wang, Jie-liang; Cui, Xiang-lin; Pei, Fei; Zheng, Jie

    2010-02-01

    To screen for novel gene(s) associated with tumor metastasis, and to investigate the effect of overexpression of phosphoprotein associated with glycosphingolipid microdomains 1 (PAG1) on the biological behaviors of human prostatic cancer cell line PC-3M-1E8 in vitro. Four cDNA microarrays were constructed using cDNA library of prostatic cancer cells PC-3M-1E8 (high metastatic potential), PC-3M-2B4 (low metastatic potential), lung cancer cells PG-BE1 (high metastatic potential)and PG-LH7 (low metastatic potential)to screen genes which were differentially expressed according to their different metastatic properties. From a battery of differentially expressed genes, PAG1, which was markedly downregulated in both high metastatic sublines of PC-3M and PG was chosen for further investigation. Real-time PCR and Western blot were used to confirm the gene expression of PAG1 at mRNA and protein levels. Full-length coding sequence of human PAG1 was subcloned into plasmid pcDNA3.0 and the recombinant plasmids were stably transfected into PC-3M-1E8. The cell proliferation ability, anchorage-independent growth, cell cycle distribution, apoptosis rates and invasive ability were detected by MTT, and in addition, soft agar colony formation, flow cytometry analysis and matrigel invasion assay using Boyden chamber were also carried out respectively. All experiments contained pcDNA3.0-PAG1-transfected clones, vector transfected clones and non-transfected parental cells. A total of 327 differentially expressed genes were obtained between the high and low metastatic sublines of PC-3M cells, including 123 upregulated and 204 downregulated genes in PC-3M-1E8. A total of 281 genes, including 167 upregulated and 114 downregulated genes were obtained in PG-BE1 cells. Nine genes were simultaneously downregulated and 8 genes were upregulated in both high metastatic cell lines of PC-3M and PG. The expression of PAG1 at mRNA and protein level were decreased in the high metastatic subline PC-3M-1

  10. Platelet activating factor-induced ceramide micro-domains drive endothelial NOS activation and contribute to barrier dysfunction.

    Directory of Open Access Journals (Sweden)

    Sanda Predescu

    Full Text Available The spatial and functional relationship between platelet activating factor-receptor (PAF-R and nitric oxide synthase (eNOS in the lateral plane of the endothelial plasma membrane is poorly characterized. In this study, we used intact mouse pulmonary endothelial cells (ECs as well as endothelial plasma membrane patches and subcellular fractions to define a new microdomain of plasmalemma proper where the two proteins colocalize and to demonstrate how PAF-mediated nitric oxide (NO production fine-tunes ECs function as gatekeepers of vascular permeability. Using fluorescence microscopy and immunogold labeling electron microscopy (EM on membrane patches we demonstrate that PAF-R is organized as clusters and colocalizes with a subcellular pool of eNOS, outside recognizable vesicular profiles. Moreover, PAF-induced acid sphingomyelinase activation generates a ceramide-based microdomain on the external leaflet of plasma membrane, inside of which a signalosome containing eNOS shapes PAF-stimulated NO production. Real-time measurements of NO after PAF-R ligation indicated a rapid (5 to 15 min increase in NO production followed by a > 45 min period of reduction to basal levels. Moreover, at the level of this new microdomain, PAF induces a dynamic phosphorylation/dephosphorylation of Ser, Thr and Tyr residues of eNOS that correlates with NO production. Altogether, our findings establish the existence of a functional partnership PAF-R/eNOS on EC plasma membrane, at the level of PAF-induced ceramide plasma membrane microdomains, outside recognized vesicular profiles.

  11. Gag Induces the Coalescence of Clustered Lipid Rafts and Tetraspanin-Enriched Microdomains at HIV-1 Assembly Sites on the Plasma Membrane ▿

    Science.gov (United States)

    Hogue, Ian B.; Grover, Jonathan R.; Soheilian, Ferri; Nagashima, Kunio; Ono, Akira

    2011-01-01

    The HIV-1 structural protein Gag associates with two types of plasma membrane microdomains, lipid rafts and tetraspanin-enriched microdomains (TEMs), both of which have been proposed to be platforms for HIV-1 assembly. However, a variety of studies have demonstrated that lipid rafts and TEMs are distinct microdomains in the absence of HIV-1 infection. To measure the impact of Gag on microdomain behaviors, we took advantage of two assays: an antibody-mediated copatching assay and a Förster resonance energy transfer (FRET) assay that measures the clustering of microdomain markers in live cells without antibody-mediated patching. We found that lipid rafts and TEMs copatched and clustered to a greater extent in the presence of membrane-bound Gag in both assays, suggesting that Gag induces the coalescence of lipid rafts and TEMs. Substitutions in membrane binding motifs of Gag revealed that, while Gag membrane binding is necessary to induce coalescence of lipid rafts and TEMs, either acylation of Gag or binding of phosphatidylinositol-(4,5)-bisphosphate is sufficient. Finally, a Gag derivative that is defective in inducing membrane curvature appeared less able to induce lipid raft and TEM coalescence. A higher-resolution analysis of assembly sites by correlative fluorescence and scanning electron microscopy showed that coalescence of clustered lipid rafts and TEMs occurs predominately at completed cell surface virus-like particles, whereas a transmembrane raft marker protein appeared to associate with punctate Gag fluorescence even in the absence of cell surface particles. Together, these results suggest that different membrane microdomain components are recruited in a stepwise manner during assembly. PMID:21813604

  12. Dynamic molecular confinement in the plasma membrane by microdomains and the cytoskeleton meshwork.

    Science.gov (United States)

    Lenne, Pierre-François; Wawrezinieck, Laure; Conchonaud, Fabien; Wurtz, Olivier; Boned, Annie; Guo, Xiao-Jun; Rigneault, Hervé; He, Hai-Tao; Marguet, Didier

    2006-07-26

    It is by now widely recognized that cell membranes show complex patterns of lateral organization. Two mechanisms involving either a lipid-dependent (microdomain model) or cytoskeleton-based (meshwork model) process are thought to be responsible for these plasma membrane organizations. In the present study, fluorescence correlation spectroscopy measurements on various spatial scales were performed in order to directly identify and characterize these two processes in live cells with a high temporal resolution, without any loss of spatial information. Putative raft markers were found to be dynamically compartmented within tens of milliseconds into small microdomains (Ø confinement of the transferrin receptor protein. A free-like diffusion was observed when both the lipid-dependent and cytoskeleton-based organizations were disrupted, which suggests that these are two main compartmentalizing forces at work in the plasma membrane.

  13. Membrane Microdomains and Cytoskeleton Organization Shape and Regulate the IL-7 Receptor Signalosome in Human CD4 T-cells*

    Science.gov (United States)

    Tamarit, Blanche; Bugault, Florence; Pillet, Anne-Hélène; Lavergne, Vincent; Bochet, Pascal; Garin, Nathalie; Schwarz, Ulf; Thèze, Jacques; Rose, Thierry

    2013-01-01

    Interleukin (IL)-7 is the main homeostatic regulator of CD4 T-lymphocytes (helper) at both central and peripheral levels. Upon activation by IL-7, several signaling pathways, mainly JAK/STAT, PI3K/Akt and MAPK, induce the expression of genes involved in T-cell differentiation, activation, and proliferation. We have analyzed the early events of CD4 T-cell activation by IL-7. We have shown that IL-7 in the first few min induces the formation of cholesterol-enriched membrane microdomains that compartmentalize its activated receptor and initiate its anchoring to the cytoskeleton, supporting the formation of the signaling complex, the signalosome, on the IL-7 receptor cytoplasmic domains. Here we describe by stimulated emission depletion microscopy the key roles played by membrane microdomains and cytoskeleton transient organization in the IL-7-regulated JAK/STAT signaling pathway. We image phospho-STAT5 and cytoskeleton components along IL-7 activation kinetics using appropriate inhibitors. We show that lipid raft inhibitors delay and reduce IL-7-induced JAK1 and JAK3 phosphorylation. Drug-induced disassembly of the cytoskeleton inhibits phospho-STAT5 formation, transport, and translocation into the nucleus that controls the transcription of genes involved in T-cell activation and proliferation. We fit together the results of these quantitative analyses and propose the following mechanism. Activated IL-7 receptors embedded in membrane microdomains induce actin-microfilament meshwork formation, anchoring microtubules that grow radially from rafted receptors to the nuclear membrane. STAT5 phosphorylated by signalosomes are loaded on kinesins and glide along the microtubules across the cytoplasm to reach the nucleus 2 min after IL-7 stimulation. Radial microtubules disappear 15 min later, while transversal microtubules, independent of phospho-STAT5 transport, begin to bud from the microtubule organization center. PMID:23329834

  14. Glycosphingolipid synthesis inhibitor AMP-DNM lowers plasma cholesterol levels by promoting fecal cholesterol excretion without inhibiting cholesterol absorption

    NARCIS (Netherlands)

    Vrins, Carlos L. J.; Bietrix, Florence; Lombardo, Elisa; van Roomen, Cindy P. A. A.; Ottenhoff, Roelof; Overkleeft, Herman S.; Aerts, Johannes M.

    2012-01-01

    Inhibition of glycosphingolipid synthesis with iminosugar N-(5'-adamantane-1'-yl-methoxy)-pentyl-1-deoxynojirimycin (AMP-DNM) increases fecal neutral sterol output in mice. To investigate which pathways were involved in this increase, C57BI/6J mice were treated with AMP-DNM and/or ezetimibe. Fecal

  15. Lck, membrane microdomains, and TCR triggering machinery: defining the new rules of engagement

    Czech Academy of Sciences Publication Activity Database

    Filipp, Dominik; Ballek, Ondřej; Manning, Jasper

    2012-01-01

    Roč. 3, June (2012), s. 155 ISSN 1664-3224 Institutional research plan: CEZ:AV0Z50520514 Keywords : Lck * Fyn * membrane microdomains * heavy and light DRMs * TCR triggering Subject RIV: EB - Genetics ; Molecular Biology

  16. Biosynthesis and degradation of mammalian glycosphingolipids.

    Science.gov (United States)

    Sandhoff, Konrad; Kolter, Thomas

    2003-01-01

    Glycolipids are a large and heterogeneous family of sphingolipids that form complex patterns on eukaryotic cell surfaces. This molecular diversity is generated by only a few enzymes and is a paradigm of naturally occurring combinatorial synthesis. We report on the biosynthetic principles leading to this large molecular diversity and focus on sialic acid-containing glycolipids of the ganglio-series. These glycolipids are particularly concentrated in the plasma membrane of neuronal cells. Their de novo synthesis starts with the formation of the membrane anchor, ceramide, at the endoplasmic reticulum (ER) and is continued by glycosyltransferases of the Golgi complex. Recent findings from genetically engineered mice are discussed. The constitutive degradation of glycosphingolipids (GSLs) occurs in the acidic compartments, the endosomes and the lysosomes. Here, water-soluble glycosidases sequentially cleave off the terminal carbohydrate residues from glycolipids. For glycolipid substrates with short oligosaccharide chains, the additional presence of membrane-active sphingolipid activator proteins (SAPs) is required. A considerable part of our current knowledge about glycolipid degradation is derived from a class of human diseases, the sphingolipidoses, which are caused by inherited defects within this pathway. A new post-translational modification is the attachment of glycolipids to proteins of the human skin. PMID:12803917

  17. Tetraspan microdomains distinct from lipid rafts enrich select peptide-MHC class II complexes

    Czech Academy of Sciences Publication Activity Database

    Kropshofer, H.; Spindeldreher, S.; Rohn, T. A.; Platania, N.; Grygar, C.; Daniel, N.; Wolpl, A.; Langen, H.; Hořejší, Václav; Vogt, A. B.

    2002-01-01

    Roč. 3, č. 1 (2002), s. 61-68 ISSN 1529-2908 Institutional research plan: CEZ:AV0Z5052915 Keywords : MHC II * tetraspan microdomains * peptide presentation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 27.868, year: 2002

  18. Overexpression of BAX INHIBITOR-1 Links Plasma Membrane Microdomain Proteins to Stress.

    Science.gov (United States)

    Ishikawa, Toshiki; Aki, Toshihiko; Yanagisawa, Shuichi; Uchimiya, Hirofumi; Kawai-Yamada, Maki

    2015-10-01

    BAX INHIBITOR-1 (BI-1) is a cell death suppressor widely conserved in plants and animals. Overexpression of BI-1 enhances tolerance to stress-induced cell death in plant cells, although the molecular mechanism behind this enhancement is unclear. We recently found that Arabidopsis (Arabidopsis thaliana) BI-1 is involved in the metabolism of sphingolipids, such as the synthesis of 2-hydroxy fatty acids, suggesting the involvement of sphingolipids in the cell death regulatory mechanism downstream of BI-1. Here, we show that BI-1 affects cell death-associated components localized in sphingolipid-enriched microdomains of the plasma membrane in rice (Oryza sativa) cells. The amount of 2-hydroxy fatty acid-containing glucosylceramide increased in the detergent-resistant membrane (DRM; a biochemical counterpart of plasma membrane microdomains) fraction obtained from BI-1-overexpressing rice cells. Comparative proteomics analysis showed quantitative changes of DRM proteins in BI-1-overexpressing cells. In particular, the protein abundance of FLOTILLIN HOMOLOG (FLOT) and HYPERSENSITIVE-INDUCED REACTION PROTEIN3 (HIR3) markedly decreased in DRM of BI-1-overexpressing cells. Loss-of-function analysis demonstrated that FLOT and HIR3 are required for cell death by oxidative stress and salicylic acid, suggesting that the decreased levels of these proteins directly contribute to the stress-tolerant phenotypes in BI-1-overexpressing rice cells. These findings provide a novel biological implication of plant membrane microdomains in stress-induced cell death, which is negatively modulated by BI-1 overexpression via decreasing the abundance of a set of key proteins involved in cell death. © 2015 American Society of Plant Biologists. All Rights Reserved.

  19. Sphingolipid levels crucially modulate lateral microdomain organization of plasma membrane in living yeast

    Czech Academy of Sciences Publication Activity Database

    Večeř, J.; Veselá, Petra; Malínský, Jan; Herman, P.

    2014-01-01

    Roč. 588, č. 3 (2014), s. 443-449 ISSN 0014-5793 R&D Projects: GA ČR GAP205/12/0720 Institutional support: RVO:68378041 Keywords : membrane microdomain * lipid order * fluidity Subject RIV: BO - Biophysics Impact factor: 3.169, year: 2014

  20. Investigations on aberrant glycosylation of glycosphingolipids in colorectal cancer tissues using liquid chromatography and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS).

    Science.gov (United States)

    Holst, Stephanie; Stavenhagen, Kathrin; Balog, Crina I A; Koeleman, Carolien A M; McDonnell, Liam M; Mayboroda, Oleg A; Verhoeven, Aswin; Mesker, Wilma E; Tollenaar, Rob A E M; Deelder, André M; Wuhrer, Manfred

    2013-11-01

    Cancer is a leading cause of death and alterations of glycosylation are characteristic features of malignant cells. Colorectal cancer is one of the most common cancers and its exact causes and biology are not yet well understood. Here, we compared glycosylation profiles of colorectal tumor tissues and corresponding control tissues of 13 colorectal cancer patients to contribute to the understanding of this cancer. Using MALDI-TOF(/TOF)-MS and 2-dimensional LC-MS/MS we characterized enzymatically released and 2-aminobenzoic acid labeled glycans from glycosphingolipids. Multivariate data analysis revealed significant differences between tumor and corresponding control tissues. Main discriminators were obtained, which represent the overall alteration in glycosylation of glycosphingolipids during colorectal cancer progression, and these were found to be characterized by (1) increased fucosylation, (2) decreased acetylation, (3) decreased sulfation, (4) reduced expression of globo-type glycans, as well as (5) disialyl gangliosides. The findings of our current research confirm former reports, and in addition expand the knowledge of glycosphingolipid glycosylation in colorectal cancer by revealing new glycans with discriminative power and characteristic, cancer-associated glycosylation alterations. The obtained discriminating glycans can contribute to progress the discovery of biomarkers to improve diagnostics and patient treatment.

  1. Investigations on Aberrant Glycosylation of Glycosphingolipids in Colorectal Cancer Tissues Using Liquid Chromatography and Matrix-Assisted Laser Desorption Time-of-Flight Mass Spectrometry (MALDI-TOF-MS)*

    Science.gov (United States)

    Holst, Stephanie; Stavenhagen, Kathrin; Balog, Crina I. A.; Koeleman, Carolien A. M.; McDonnell, Liam M.; Mayboroda, Oleg A.; Verhoeven, Aswin; Mesker, Wilma E.; Tollenaar, Rob A. E. M.; Deelder, André M.; Wuhrer, Manfred

    2013-01-01

    Cancer is a leading cause of death and alterations of glycosylation are characteristic features of malignant cells. Colorectal cancer is one of the most common cancers and its exact causes and biology are not yet well understood. Here, we compared glycosylation profiles of colorectal tumor tissues and corresponding control tissues of 13 colorectal cancer patients to contribute to the understanding of this cancer. Using MALDI-TOF(/TOF)-MS and 2-dimensional LC-MS/MS we characterized enzymatically released and 2-aminobenzoic acid labeled glycans from glycosphingolipids. Multivariate data analysis revealed significant differences between tumor and corresponding control tissues. Main discriminators were obtained, which represent the overall alteration in glycosylation of glycosphingolipids during colorectal cancer progression, and these were found to be characterized by (1) increased fucosylation, (2) decreased acetylation, (3) decreased sulfation, (4) reduced expression of globo-type glycans, as well as (5) disialyl gangliosides. The findings of our current research confirm former reports, and in addition expand the knowledge of glycosphingolipid glycosylation in colorectal cancer by revealing new glycans with discriminative power and characteristic, cancer-associated glycosylation alterations. The obtained discriminating glycans can contribute to progress the discovery of biomarkers to improve diagnostics and patient treatment. PMID:23878401

  2. Dynein Clusters into Lipid Microdomains on Phagosomes to Drive Rapid Transport toward Lysosomes.

    Science.gov (United States)

    Rai, Ashim; Pathak, Divya; Thakur, Shreyasi; Singh, Shampa; Dubey, Alok Kumar; Mallik, Roop

    2016-02-11

    Diverse cellular processes are driven by motor proteins that are recruited to and generate force on lipid membranes. Surprisingly little is known about how membranes control the force from motors and how this may impact specific cellular functions. Here, we show that dynein motors physically cluster into microdomains on the membrane of a phagosome as it matures inside cells. Such geometrical reorganization allows many dyneins within a cluster to generate cooperative force on a single microtubule. This results in rapid directed transport of the phagosome toward microtubule minus ends, likely promoting phagolysosome fusion and pathogen degradation. We show that lipophosphoglycan, the major molecule implicated in immune evasion of Leishmania donovani, inhibits phagosome motion by disrupting the clustering and therefore the cooperative force generation of dynein. These findings appear relevant to several pathogens that prevent phagosome-lysosome fusion by targeting lipid microdomains on phagosomes. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Spatio-temporal Remodeling of Functional Membrane Microdomains Organizes the Signaling Networks of a Bacterium

    NARCIS (Netherlands)

    Schneider, Johannes; Klein, Teresa; Mielich-Süss, Benjamin; Koch, Gudrun; Franke, Christian; Kuipers, Oscar P; Kovács, Ákos T; Sauer, Markus; Lopez, Daniel

    Lipid rafts are membrane microdomains specialized in the regulation of numerous cellular processes related to membrane organization, as diverse as signal transduction, protein sorting, membrane trafficking or pathogen invasion. It has been proposed that this functional diversity would require a

  4. Controlling sub-microdomain structure in microphase-ordered block copolymers and their nanocomposites

    Science.gov (United States)

    Bowman, Michelle Kathleen

    Block copolymers exhibit a wealth of morphologies that continue to find ubiquitous use in a diverse variety of mature and emergent (nano)technologies, such as photonic crystals, integrated circuits, pharmaceutical encapsulents, fuel cells and separation membranes. While numerous studies have explored the effects of molecular confinement on such copolymers, relatively few have examined the sub-microdomain structure that develops upon modification of copolymer molecular architecture or physical incorporation of nanoscale objects. This work will address two relevant topics in this vein: (i) bidisperse brushes formed by single block copolymer molecules and (ii) copolymer nanocomposites formed by addition of molecular or nanoscale additives. In the first case, an isomorphic series of asymmetric poly(styrene-b -isoprene-b-styrene) (S1IS2) triblock copolymers of systematically varied chain length has been synthesized from a parent SI diblock copolymer. Small-angle x-ray scattering, coupled with dynamic rheology and self-consistent field theory (SCFT), reveals that the progressively grown S2 block initially resides in the I-rich matrix and effectively reduces the copolymer incompatibility until a critical length is reached. At this length, the S2 block co-locates with the S1 block so that the two blocks generate a bidisperse brush (insofar as the S1 and S2 lengths differ). This single-molecule analog to binary block copolymer blends affords unique opportunities for materials design at sub-microdomain length scales and provides insight into the transition from diblock to triblock copolymer (and thermoplastic elastomeric nature). In the second case, I explore the distribution of molecular and nanoscale additives in microphase-ordered block copolymers and demonstrate via SCFT that an interfacial excess, which depends strongly on additive concentration, selectivity and relative size, develops. These predictions are in agreement with experimental findings. Moreover, using a

  5. Membrane microdomains, rafts, and detergent-resistant membranes in plants and fungi

    Czech Academy of Sciences Publication Activity Database

    Malínský, Jan; Opekarová, Miroslava; Grossmann, G.; Tanner, W.

    2013-01-01

    Roč. 64, April (2013), s. 501-529 ISSN 1543-5008 R&D Projects: GA ČR(CZ) GAP302/11/0146; GA ČR GAP205/12/0720 Institutional research plan: CEZ:AV0Z50390703 Institutional support: RVO:61388971 ; RVO:68378041 Keywords : membrane microdomain * lipid raft * detergent resistant membranes Subject RIV: EB - Genetics ; Molecular Biology; EA - Cell Biology (MBU-M) Impact factor: 18.900, year: 2013

  6. Calcium microdomains near R-type calcium channels control the induction of presynaptic LTP at parallel fiber to Purkinje cell synapses

    Science.gov (United States)

    Myoga, Michael H.; Regehr, Wade G.

    2011-01-01

    R-type calcium channels in postsynaptic spines signal through functional calcium microdomains to regulate a calcium-calmodulin sensitive potassium channel that in turn regulates postsynaptic hippocampal LTP. Here we ask whether R-type calcium channels in presynaptic terminals also signal through calcium microdomains to control presynaptic LTP. We focus on presynaptic LTP at parallel fiber to Purkinje cell synapses in the cerebellum (PF-LTP), which is mediated by calcium/calmodulin-stimulated adenylyl cyclases. Although most presynaptic calcium influx is through N-type and P/Q-type calcium channels, blocking these channels does not disrupt PF-LTP, but blocking R-type calcium channels does. Moreover, global calcium signaling cannot account for the calcium dependence of PF-LTP because R-type channels contribute modestly to overall calcium entry. These findings indicate that within presynaptic terminals, R-type calcium channels produce calcium microdomains that evoke presynaptic LTP at moderate frequencies that do not greatly increase global calcium levels,. PMID:21471358

  7. Dietary free fatty acids form alkaline phosphatase-enriched microdomains in the intestinal brush border membrane

    DEFF Research Database (Denmark)

    Hansen, Gert H; Rasmussen, Karina; Niels-Christiansen, Lise-Lotte

    2011-01-01

    this membrane passage in organ cultured intestinal mucosal explants. We found that in addition to a rapid uptake into the cytoplasm, a fraction of the fatty acid analogs were inserted directly into the brush border membrane. Furthermore, a brief exposure of microvillar membrane vesicles to a fat mixture...... mimicking a physiological solution of dietary mixed micelles, rearranged the lipid raft microdomain organization of the membranes. Thus, the fat mixture generated a low-density subpopulation of microvillar detergent resistant membranes (DRMs) highly enriched in alkaline phosphatase (AP). Since this GPI-linked...... enzyme is the membrane protein in the brush border with the highest affinity for lipid rafts, this implies that free fatty acids selectively insert stably into these membrane microdomains. We have previously shown that absorption of dietary lipids transiently induce a selective endocytosis of AP from...

  8. New Insight Into the Roles of Membrane Microdomains in Physiological Activities of Fungal Cells.

    Czech Academy of Sciences Publication Activity Database

    Malínský, Jan; Opekarová, Miroslava

    2016-01-01

    Roč. 325, mar. (2016), s. 119-180 ISSN 1937-6448 R&D Projects: GA ČR(CZ) GA15-10641S Institutional support: RVO:68378041 Keywords : membrane microdomain * membrane structure * fungi * membrane contact sites Subject RIV: EA - Cell Biology Impact factor: 3.752, year: 2015

  9. Peptide-selective inrichment of MHC II-peptide complexes in tetraspan microdomains distinct from lipid rafts

    Czech Academy of Sciences Publication Activity Database

    Kropshofer, H.; Spindeldreher, S.; Rohn, T. A.; Platania, N.; Grygar, C.; Wolpl, A.; Langen, H.; Hořejší, Václav; Vogt, A. B.

    2002-01-01

    Roč. 3, č. 1 (2002), s. 61-68 ISSN 1529-2908 R&D Projects: GA MŠk LN00A026 Keywords : Microdomain * tetraspan proteins * MHC class II Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 27.868, year: 2002

  10. Bicarbonate-responsive “soluble” adenylyl cyclase defines a nuclear cAMP microdomain

    Science.gov (United States)

    Zippin, Jonathan H.; Farrell, Jeanne; Huron, David; Kamenetsky, Margarita; Hess, Kenneth C.; Fischman, Donald A.; Levin, Lonny R.; Buck, Jochen

    2004-01-01

    Bicarbonate-responsive “soluble” adenylyl cyclase resides, in part, inside the mammalian cell nucleus where it stimulates the activity of nuclear protein kinase A to phosphorylate the cAMP response element binding protein (CREB). The existence of this complete and functional, nuclear-localized cAMP pathway establishes that cAMP signals in intracellular microdomains and identifies an alternate pathway leading to CREB activation. PMID:14769862

  11. Use of quantitative optical imaging to examine the role of cholesterol-rich lipid raft microdomains in the migration of breast cancer cells

    Science.gov (United States)

    You, Minghai; Chen, Jianling; Wang, Shaobing; Dong, Shiqing; Wang, Yuhua; Xie, Shusen; Wang, Zhengchao; Yang, Hongqin

    2018-04-01

    Lipid rafts have been extensively studied and shown to be involved in many cancers, including breast cancer. However, the exact role of lipid rafts in the migration of breast cancer cells remains unclear. This study was designed to examine lipid rafts (cholesterol) in the plasma membrane of breast cancer cells (MDA-MB-231 and MCF-7) and normal breast epithelial cells (MCF-10A) through generalized polarization values, and further investigate the role of cholesterol-rich lipid rafts in the migration of breast cancer cells. The results showed that the plasma membrane in breast cancer cells was more orderly than that in normal epithelial cells; this was correlated with expression changes of matrix metallopeptidase 9 (MMP-9) and urokinase-type plasminogen activator receptor (uPAR), the markers of cancer cell migration. Moreover, the breast cancer cells were more sensitive to the reagent that induced cholesterol depletion than the normal breast epithelial cells, while the capacity of cancer cells to migrate decreased significantly according to changes in MMP-9 and uPAR expression. To our best knowledge, this is the first demonstration of the relationship between cholesterol-rich lipid rafts and the migration of breast cancer cells; it could be useful for the prevention of breast cancer and early treatment through reduction of the level of cholesterol in the plasma membrane of the cells.

  12. Learning Rich Features from RGB-D Images for Object Detection and Segmentation

    OpenAIRE

    Gupta, Saurabh; Girshick, Ross; Arbeláez, Pablo; Malik, Jitendra

    2014-01-01

    In this paper we study the problem of object detection for RGB-D images using semantically rich image and depth features. We propose a new geocentric embedding for depth images that encodes height above ground and angle with gravity for each pixel in addition to the horizontal disparity. We demonstrate that this geocentric embedding works better than using raw depth images for learning feature representations with convolutional neural networks. Our final object detection system achieves an av...

  13. Correction of liver steatosis by a hydrophobic iminosugar modulating glycosphingolipids metabolism.

    Directory of Open Access Journals (Sweden)

    Elisa Lombardo

    Full Text Available The iminosugar N-(5'-adamantane-1'-yl-methoxy-pentyl-1-deoxynoijirimycin (AMP-DNM, an inhibitor of glycosphingolipid (GSL biosynthesis is known to ameliorate diabetes, insulin sensitivity and to prevent liver steatosis in ob/ob mice. Thus far the effect of GSL synthesis inhibition on pre-existing NASH has not yet been assessed. To investigate it, LDLR(-/- mice were kept on a western-type diet for 12 weeks to induce NASH. Next, the diet was continued for 6 weeks in presence or not of AMP-DNM in the diet. AMP-DNM treated mice showed less liver steatosis, inflammation and fibrosis. Induction of fatty acid beta-oxydation was observed, as well as a reduction of plasma lipids. Our study demonstrates that AMP-DNM treatment is able to significantly correct pre-existing NASH, suggesting that inhibiting GSL synthesis may represent a novel strategy for the treatment of this pathology.

  14. FLUORESCENCE SPECTROSCOPIC STUDY OF THE FORMATION OF HYDROPHOBIC MICRODOMAINS IN AQUEOUS-SOLUTIONS OF POLY(ALKYLMETHYLDIALLYLAMMONIUM BROMIDES)

    NARCIS (Netherlands)

    YANG, YJ; Engberts, Jan B F N

    The conformational state of poly(alkylmethyldiallylammonium bromides) was studied in aqueous solutions using pyrene as a fluorescence probe. The results are indicative for the formation of hydrophobic microdomains in the case of several copolymers which possess sufficiently hydrophobic alkyl side

  15. Inhibition of Glycosphingolipid Synthesis Induces a Profound Reduction of Plasma Cholesterol and Inhibits Atherosclerosis Development in APOE*3 Leiden and Low-Density Lipoprotein Receptor-/- Mice

    NARCIS (Netherlands)

    Bietrix, Florence; Lombardo, Elisa; van Roomen, Cindy P. A. A.; Ottenhoff, Roelof; Vos, Mariska; Rensen, Patrick C. N.; Verhoeven, Arthur J.; Aerts, Johannes M.; Groen, Albert K.

    Objective-The iminosugar N-(5'-adamantane-1'-yl-methoxy)-pentyl-1-deoxynoijirimycin (AMP-DNM), an inhibitor of the enzyme glucosylceramide synthase catalyzing glycosphingolipid (GSL) biosynthesis, ameliorates diabetes and reduces liver steatosis in ob/ob mice. Because an accumulation of

  16. Disclosure of domain structure in cubic CaxZr1-xO2-x, 0x15 ≤ x ≤ 0x20, by Talbot image enhancement of high-resolution electron micrographs

    International Nuclear Information System (INIS)

    Rossell, H.J.; Wilson, I.J.; Sellar, J.R.

    1991-01-01

    High-resolution electron microscope images have been recorded of several cystalline samples of calcia-stabilized zirconia (Ca-CSZ) and of the fluorite-related superstructure phase φ 1 (CaZr 4 O 9 ). The contrast of the CSZ images has been enhanced markedly by the light-optical Talbot self-imaging technique. Is is demonstrated that the CSZ crystals contain a coherent dispersion of microdomains approximately 30 A in diameter, and that the structure of the microdomains is that of φ 1 . (orig.)

  17. Effect of Galactosylceramide on the Dynamics of Cholesterol-Rich Lipid Membranes

    DEFF Research Database (Denmark)

    Hall, A.; Rog, T.; Vattulainen, I.

    2011-01-01

    We use atom-scale molecular dynamics simulations to clarify the role of glycosphingolipids in the dynamics of cholesterol-rich lipid rafts. To this end, we consider lipid membranes that contain varying. amounts of galactosylceramide (GalCer), sphingomyelin, cholesterol, and phosphatidylcholine....... The results indicate that increasing the portion of GalCer molecules greatly slows down the lateral diffusion, Only 5-10 mol % of GalCer causes a decrease of almost an order of magnitude compared to corresponding membranes without GalCer. The slowing down is not related to interdigitation, which becomes...... weaker with increasing GalCer concentration. Instead, the decrease in diffusion is found to correlate with the increasing number of hydrogen bonds formed between GalCer and the phospholipid molecules, which is also observed to have other effects, such as to increase the friction between the membrane...

  18. Apicobasal domain identities of expanding tubular membranes depend on glycosphingolipid biosynthesis.

    Science.gov (United States)

    Zhang, Hongjie; Abraham, Nessy; Khan, Liakot A; Hall, David H; Fleming, John T; Göbel, Verena

    2011-09-18

    Metazoan internal organs are assembled from polarized tubular epithelia that must set aside an apical membrane domain as a lumenal surface. In a global Caenorhabditis elegans tubulogenesis screen, interference with several distinct fatty-acid-biosynthetic enzymes transformed a contiguous central intestinal lumen into multiple ectopic lumens. We show that multiple-lumen formation is caused by apicobasal polarity conversion, and demonstrate that in situ modulation of lipid biosynthesis is sufficient to reversibly switch apical domain identities on growing membranes of single post-mitotic cells, shifting lumen positions. Follow-on targeted lipid-biosynthesis pathway screens and functional genetic assays were designed to identify a putative single causative lipid species. They demonstrate that fatty-acid biosynthesis affects polarity through sphingolipid synthesis, and reveal ceramide glucosyltransferases (CGTs) as end-point biosynthetic enzymes in this pathway. Our findings identify glycosphingolipids, CGT products and obligate membrane lipids, as critical determinants of in vivo polarity and indicate that they sort new components to the expanding apical membrane.

  19. Evaluation of Co-rich manganese deposits by image analysis and photogrammetric techniques

    Digital Repository Service at National Institute of Oceanography (India)

    Yamazaki, T.; Sharma, R.; Tsurusaki, K.

    Stereo-seabed photographs of Co-rich manganese deposits on a mid-Pacific seamount, were analysed using an image analysis software for coverage estimation and size classification of nodules, and a photogrammetric software for calculation of height...

  20. Assembly of fission yeast eisosomes in the plasma membrane of budding yeast: Import of foreign membrane microdomains

    Czech Academy of Sciences Publication Activity Database

    Vaškovičová, Katarína; Strádalová, Vendula; Efenberk, Aleš; Opekarová, Miroslava; Malínský, Jan

    2015-01-01

    Roč. 94, č. 1 (2015), s. 1-11 ISSN 0171-9335 R&D Projects: GA ČR(CZ) GAP302/11/0146 Institutional support: RVO:68378041 Keywords : plasma membrane * membrane microdomain * MCC Subject RIV: EA - Cell Biology Impact factor: 4.011, year: 2015

  1. Super Resolution Fluorescence Microscopy and Tracking of Bacterial Flotillin (Reggie Paralogs Provide Evidence for Defined-Sized Protein Microdomains within the Bacterial Membrane but Absence of Clusters Containing Detergent-Resistant Proteins.

    Directory of Open Access Journals (Sweden)

    Felix Dempwolff

    2016-06-01

    Full Text Available Biological membranes have been proposed to contain microdomains of a specific lipid composition, in which distinct groups of proteins are clustered. Flotillin-like proteins are conserved between pro-and eukaryotes, play an important function in several eukaryotic and bacterial cells, and define in vertebrates a type of so-called detergent-resistant microdomains. Using STED microscopy, we show that two bacterial flotillins, FloA and FloT, form defined assemblies with an average diameter of 85 to 110 nm in the model bacterium Bacillus subtilis. Interestingly, flotillin microdomains are of similar size in eukaryotic cells. The soluble domains of FloA form higher order oligomers of up to several hundred kDa in vitro, showing that like eukaryotic flotillins, bacterial assemblies are based in part on their ability to self-oligomerize. However, B. subtilis paralogs show significantly different diffusion rates, and consequently do not colocalize into a common microdomain. Dual colour time lapse experiments of flotillins together with other detergent-resistant proteins in bacteria show that proteins colocalize for no longer than a few hundred milliseconds, and do not move together. Our data reveal that the bacterial membrane contains defined-sized protein domains rather than functional microdomains dependent on flotillins. Based on their distinct dynamics, FloA and FloT confer spatially distinguishable activities, but do not serve as molecular scaffolds.

  2. Temperature-dependent imaging of living cells by AFM

    International Nuclear Information System (INIS)

    Espenel, Cedric; Giocondi, Marie-Cecile; Seantier, Bastien; Dosset, Patrice; Milhiet, Pierre-Emmanuel; Le Grimellec, Christian

    2008-01-01

    Characterization of lateral organization of plasma membranes is a prerequisite to the understanding of membrane structure-function relationships in living cells. Lipid-lipid and lipid-protein interactions are responsible for the existence of various membrane microdomains involved in cell signalization and in numerous pathologies. Developing approaches for characterizing microdomains associate identification tools like recognition imaging with high-resolution topographical imaging. Membrane properties are markedly dependent on temperature. However, mesoscopic scale topographical information of cell surface in a temperature range covering most of cell biology experimentation is still lacking. In this work we have examined the possibility of imaging the temperature-dependent behavior of eukaryotic cells by atomic force microscopy (AFM). Our results establish that the surface of living CV1 kidney cells can be imaged by AFM, between 5 and 37 deg. C, both in contact and tapping modes. These first temperature-dependent data show that large cell structures appeared essentially stable at a microscopic scale. On the other hand, as shown by contact mode AFM, the surface was highly dynamic at a mesoscopic scale, with marked changes in apparent topography, friction, and deflection signals. When keeping the scanning conditions constant, a progressive loss in the image contrast was however observed, using tapping mode, on decreasing the temperature

  3. FLUORESCENCE PROBING OF THE FORMATION OF HYDROPHOBIC MICRODOMAINS BY CROSS-LINKED POLY(ALKYLMETHYLDIALLYLAMMONIUM BROMIDES) IN AQUEOUS-SOLUTION

    NARCIS (Netherlands)

    WANG, GJ; ENGBERTS, J B F N

    Pyrene has been used as a fluorescence probe to investigate the conformational behavior of cross-linked poly(alkylmethyldiallylammonium bromides) in aqueous solutions. Binding of pyrene to hydrophobic microdomains, formed by the polysoaps, is reflected by a change in the ratio I-1/I-3 of the

  4. Studies on micro-domain structure in segmented polyether polyurethane-ureas by positron annihilation lifetime and small-angle X-ray scattering

    International Nuclear Information System (INIS)

    Yin Chuanyuan; Gu Qingchao

    1997-01-01

    The micro-domain structure of segmented polyether polyurethane-ureas is investigated by means of positron annihilation lifetime spectroscopy, small-angle X-ray scattering and differential scanning calorimetry. The experimental results show that the decrease in the domain volume and free volume results from the increase in the hard segment (polyurethane-urea segment) contents as the number-average molecular weight M n -bar of the soft segments (polyethylene glycol segments) is the same, and that the increase in domain volume and free volume result from the increase in the M n -bar of the soft segments when the hard segment content is the same or nearly the same. These results demonstrate that positron annihilation lifetime spectroscopy is a sensitive technique to probe the micro-domain structure in polymers

  5. Membrane compartment of Can1 (MCC): specialized functional microdomain of the yeast plasma membrane

    OpenAIRE

    Doudová, Lenka

    2017-01-01

    Membrane compartment of Can1 (MCC): specialized functional microdomain of the yeast plasma membrane Yeast plasma membrane is divided into several different compartments. Membrane compartment of Can1 is specific for its protein and lipid composition, furthermore it creates furrow-like invaginations on the plasma membrane. These invaginations are made by multiprotein complexes called eisosomes, which are located in the cytosolic side of MCCs. It was established that this domain plays an importa...

  6. 3D confocal Raman imaging of oil-rich emulsion from enzyme-assisted aqueous extraction of extruded soybean powder.

    Science.gov (United States)

    Wu, Longkun; Wang, Limin; Qi, Baokun; Zhang, Xiaonan; Chen, Fusheng; Li, Yang; Sui, Xiaonan; Jiang, Lianzhou

    2018-05-30

    The understanding of the structure morphology of oil-rich emulsion from enzyme-assisted extraction processing (EAEP) was a critical step to break the oil-rich emulsion structure in order to recover oil. Albeit EAEP method has been applied as an alternative way to conventional solvent extraction method, the structure morphology of oil-rich emulsion was still unclear. The current study aimed to investigate the structure morphology of oil-rich emulsion from EAEP using 3D confocal Raman imaging technique. With increasing the enzymatic hydrolysis duration from 1 to 3 h, the stability of oil-rich emulsion was decreased as visualized in the 3D confocal Raman images that the protein and oil were mixed together. The subsequent Raman spectrum analysis further revealed that the decreased stability of oil-rich emulsion was due to the protein aggregations via SS bonds or protein-lipid interactions. The conformational transfer in protein indicated the formation of a compact structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Neuroglobin overexpression plays a pivotal role in neuroprotection through mitochondrial raft-like microdomains in neuroblastoma SK-N-BE2 cells.

    Science.gov (United States)

    Garofalo, Tina; Ferri, Alberto; Sorice, Maurizio; Azmoon, Pardis; Grasso, Maria; Mattei, Vincenzo; Capozzi, Antonella; Manganelli, Valeria; Misasi, Roberta

    2018-04-01

    Since stressing conditions induce a relocalization of endogenous human neuroglobin (NGB) to mitochondria, this research is aimed to evaluate the protective role of NGB overexpression against neurotoxic stimuli, through mitochondrial lipid raft-associated complexes. To this purpose, we built a neuronal model of oxidative stress by the use of human dopaminergic neuroblastoma cells, SK-N-BE2, stably overexpressing NGB by transfection and treated with 1-methyl-4-phenylpyridinium ion (MPP+). We preliminary observed the redistribution of NGB to mitochondria following MPP+ treatment. The analysis of mitochondrial raft-like microdomains revealed that, following MPP+ treatment, NGB translocated to raft fractions (Triton X-100-insoluble), where it interacts with ganglioside GD3. Interestingly, the administration of agents capable of perturbating microdomain before MPP+ treatment, significantly affected viability in SK-N-BE2-NGB cells. The overexpression of NGB was able to abrogate the mitochondrial injuries on complex IV activity or mitochondrial morphology induced by MPP+ administration. The protective action of NGB on mitochondria only takes place if the mitochondrial lipid(s) rafts-like microdomains are intact, indeed NGB fails to protect complex IV activity when purified mitochondria were treated with the lipid rafts disruptor methyl-β-cyclodextrin. Thus, our unique in vitro model of stably transfected cells overexpressing endogenous NGB allowed us to suggest that the role in neuroprotection played by NGB is reliable only through interaction with mitochondrial lipid raft-associated complexes. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Lipid raft localization of GABA A receptor and Na+, K+-ATPase in discrete microdomain clusters in rat cerebellar granule cells

    DEFF Research Database (Denmark)

    Dalskov, Stine-Mathilde; Immerdal, Lissi; Niels-Christiansen, Lise-Lotte W

    2005-01-01

    The microdomain localization of the GABA(A) receptor in rat cerebellar granule cells was studied by subcellular fractionation and fluorescence- and immunogold electron microscopy. The receptor resided in lipid rafts, prepared at 37 degrees C by extraction with the nonionic detergent Brij 98......, but the raft fraction, defined by the marker ganglioside GM(1) in the floating fractions following density gradient centrifugation, was heterogeneous in density and protein composition. Thus, another major raft-associated membrane protein, the Na(+), K(+)-ATPase, was found in discrete rafts of lower density......, reflecting clustering of the two proteins in separate membrane microdomains. Both proteins were observed in patchy "hot spots" at the cell surface as well as in isolated lipid rafts. Their insolubility in Brij 98 was only marginally affected by methyl-beta-cyclodextrin. In contrast, both the GABA(A) receptor...

  9. Expressão de glicoesfingolipídeos no carcinoma espinocelular do trato aerodigestivo superior Glycosphingolipid expression in squamous cell carcinoma of the upper aerodigestive tract

    Directory of Open Access Journals (Sweden)

    Marcilio Ferreira Marques Filho

    2006-02-01

    cell growth, invasiveness, and metastatic potential. AIM: However, there are few studies about glycosphingolipids (GSL expression in squamous cell carcinoma (SCC. Since GSL are known to be tumor-associated markers we decided to perform a prospective study on the GSL profiles of SCC. METHOD: Specimens of 33 SCC and normal mucosa were obtained and GSLs were extracted and purified by reverse-phase chromatography on C18 column and alkaline hydrolysis in methanol. GSLs were quantified using densitometry of orcinol-stained HPTLC plates. RESULT: A significant increase of GSLs in SCC (3.57µg/mg was observed as compared to normal mucosa (1.92µg/mg. In SCC, an increase of 2 to 3 times in the amounts of CDH, CTH, Globoside, and GM3 was observed in comparison to normal mucosa. The identification of GM3 as well as its increased expression in SCC was confirmed unequivocally by HPTLC immunostaining and indirect immunofluorescence using MAb DH2 (anti-GM3. BY analyzing SCC and normal mucosa CMHs by GC/MS, normal mucosa expresses only glucosylceramide whereas SCC cells express both glucosylceramide and galactosylceramide. CONCLUSION: The increase in the amount of GSLs in tumor tissue may represent changes of cell membrane microdomains resulting from the malignant transformation process, which is responsible for greater cell-cell or cell-matrix interaction thereby increasing their potential for infiltration and metastasis.

  10. Switching of the core structures of glycosphingolipids from globo- and lacto- to ganglio-series upon human embryonic stem cell differentiation.

    Science.gov (United States)

    Liang, Yuh-Jin; Kuo, Huan-Hsien; Lin, Chi-Hung; Chen, Yen-Ying; Yang, Bei-Chia; Cheng, Yuan-Yuan; Yu, Alice L; Khoo, Kay-Hooi; Yu, John

    2010-12-28

    A systematic survey of expression profiles of glycosphingolipids (GSLs) in two hESC lines and their differentiated embryoid body (EB) outgrowth with three germ layers was carried out using immunofluorescence, flow cytometry, and MALDI-MS and MS/MS analyses. In addition to the well-known hESC-specific markers stage-specific embryonic antigen 3 (SSEA-3) and SSEA-4, we identified several globosides and lacto-series GSLs, previously unrevealed in hESCs, including Gb(4)Cer, Lc(4)Cer, fucosyl Lc(4)Cer, Globo H, and disialyl Gb(5)Cer. During hESC differentiation into EBs, MS analysis revealed a clear-cut switch in the core structures of GSLs from globo- and lacto- to ganglio-series, which was not as evident by immunostaining with antibodies against SSEA-3 and SSEA-4, owing to their cross-reactivities with various glycosphingolipids. Such a switch was attributable to altered expression of key glycosyltransferases (GTs) in the biosynthetic pathways by the up-regulation of ganglio-series-related GTs with simultaneous down-regulation of globo- and lacto-series-related GTs. Thus, these results provide insights into the unique stage-specific transition and mechanism for alterations of GSL core structures during hESC differentiation. In addition, unique glycan structures uncovered by MS analyses may serve as surface markers for further delineation of hESCs and help identify of their functional roles not only in hESCs but also in cancers.

  11. Aminopeptidase N/CD13 is associated with raft membrane microdomains in monocytes

    DEFF Research Database (Denmark)

    Navarrete Santos, A; Roentsch, J; Danielsen, E M

    2000-01-01

    as in adhesion and cell-cell interactions. Here, we report for the first time that aminopeptidase N/CD13 in monocytes is partially localized in detergent-insoluble membrane microdomains enriched in cholesterol, glycolipids, and glycosylphosphoinositol-anchored proteins, referred to as "rafts." Raft fractions...... of monocytes were characterized by the presence of GM1 ganglioside as raft marker molecule and by the high level of tyrosine-phosphorylated proteins. Furthermore, similar to polarized cells, rafts in monocytic cells lack Na(+), K(+)-ATPase. Cholesterol depletion of monocytes by methyl-beta-cyclodextrin greatly...... reduces raft localization of aminopeptidase N/CD13 without affecting ala-p-nitroanilide cleaving activity of cells....

  12. Evaluation of combined near-IR spectroscopic (NIRS)-IVUS imaging as a means to detect lipid-rich plaque burden in human coronary autopsy specimens

    Science.gov (United States)

    Su, Jimmy L.; Grainger, Stephanie J.; Greiner, Cherry A.; Hendricks, Michael J.; Goode, Meghan M.; Saybolt, Matthew D.; Wilensky, Robert L.; Madden, Sean P.; Muller, James E.

    2016-02-01

    Intracoronary near-infrared spectroscopy (NIRS) can identify lipid in the coronary arteries, but lacks depth resolution. A novel catheter is currently in clinical use that combines NIRS with intravascular ultrasound (IVUS), which provides depth-resolved structural information via the IVUS modality. A measure designated as lipid-rich plaque burden (LRPB) has been proposed as a means to interpret the combined acoustic and optical information of NIRS-IVUS. LRPB is defined as the area created by the intersection of the NIRS lipid-rich arc with the corresponding IVUS-measured plaque burden. We determined the correlation in human coronary autopsy specimens between LRPB, a measure of lipid presence and extent available via intravascular imaging in patients, and the area of lipid-rich plaque as determined by the gold-standard of histology. Fifteen artery segments from 8 human autopsy hearts were imaged with the NIRS-IVUS system (TVC Imaging System, Infraredx Inc., Burlington, MA). Arteries were imaged in a specialty fixture that assured accurate co-registration between imaging and histology. The arteries were then fixed and divided into 2 mm blocks for histological staining. Pathological contouring of lipid-rich areas was performed on the stained thin sections for 54 lipid-rich blocks. Computation of LRPB was performed on transverse NIRS-IVUS frames corresponding to the histologic sections. The quantified LRPB was frequently higher than the lipid-rich plaque area determined by histology, because the region denoted by the EEL and lumen within the NIRS lipid-rich arc is not entirely comprised of lipid. Overall, a moderate to strong correlation (R = 0.73) was found between LRPB determined by NIRS-IVUS imaging and the lipid-rich plaque area determined by histology. LRPB, which can be measured in patients with NIRS-IVUS imaging, corresponds to the amount of lipid-rich plaque in a coronary artery. LRPB should be evaluated in prospective clinical trials for its ability to

  13. The Pseudomonas aeruginosa lectin LecA triggers host cell signalling by glycosphingolipid-dependent phosphorylation of the adaptor protein CrkII.

    Science.gov (United States)

    Zheng, Shuangshuang; Eierhoff, Thorsten; Aigal, Sahaja; Brandel, Annette; Thuenauer, Roland; de Bentzmann, Sophie; Imberty, Anne; Römer, Winfried

    2017-07-01

    The human pathogen Pseudomonas aeruginosa induces phosphorylation of the adaptor protein CrkII by activating the non-receptor tyrosine kinase Abl to promote its uptake into host cells. So far, specific factors of P. aeruginosa, which induce Abl/CrkII signalling, are entirely unknown. In this research, we employed human lung epithelial cells H1299, Chinese hamster ovary cells and P. aeruginosa wild type strain PAO1 to study the invasion process of P. aeruginosa into host cells by using microbiological, biochemical and cell biological approaches such as Western Blot, immunofluorescence microscopy and flow cytometry. Here, we demonstrate that the host glycosphingolipid globotriaosylceramide, also termed Gb3, represents a signalling receptor for the P. aeruginosa lectin LecA to induce CrkII phosphorylation at tyrosine 221. Alterations in Gb3 expression and LecA function correlate with CrkII phosphorylation. Interestingly, phosphorylation of CrkII Y221 occurs independently of Abl kinase. We further show that Src family kinases transduce the signal induced by LecA binding to Gb3, leading to Crk Y221 phosphorylation. In summary, we identified LecA as a bacterial factor, which utilizes a so far unrecognized mechanism for phospho-CrkII Y221 induction by binding to the host glycosphingolipid receptor Gb3. The LecA/Gb3 interaction highlights the potential of glycolipids to mediate signalling processes across the plasma membrane and should be further elucidated to gain deeper insights into this non-canonical mechanism of activating host cell processes. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Shotgun proteomics of plant plasma membrane and microdomain proteins using nano-LC-MS/MS.

    Science.gov (United States)

    Takahashi, Daisuke; Li, Bin; Nakayama, Takato; Kawamura, Yukio; Uemura, Matsuo

    2014-01-01

    Shotgun proteomics allows the comprehensive analysis of proteins extracted from plant cells, subcellular organelles, and membranes. Previously, two-dimensional gel electrophoresis-based proteomics was used for mass spectrometric analysis of plasma membrane proteins. In order to get comprehensive proteome profiles of the plasma membrane including highly hydrophobic proteins with a number of transmembrane domains, a mass spectrometry-based shotgun proteomics method using nano-LC-MS/MS for proteins from the plasma membrane proteins and plasma membrane microdomain fraction is described. The results obtained are easily applicable to label-free protein semiquantification.

  15. Chronic cyclodextrin treatment of murine Niemann-Pick C disease ameliorates neuronal cholesterol and glycosphingolipid storage and disease progression.

    Directory of Open Access Journals (Sweden)

    Cristin D Davidson

    2009-09-01

    Full Text Available Niemann-Pick type C (NPC disease is a fatal neurodegenerative disorder caused most commonly by a defect in the NPC1 protein and characterized by widespread intracellular accumulation of unesterified cholesterol and glycosphingolipids (GSLs. While current treatment therapies are limited, a few drugs tested in Npc1(-/- mice have shown partial benefit. During a combination treatment trial using two such compounds, N-butyldeoxynojirimycin (NB-DNJ and allopregnanolone, we noted increased lifespan for Npc1(-/- mice receiving only 2-hydroxypropyl-beta-cyclodextrin (CD, the vehicle for allopregnanolone. This finding suggested that administration of CD alone, but with greater frequency, might provide additional benefit.Administration of CD to Npc1(-/- mice beginning at either P7 or P21 and continuing every other day delayed clinical onset, reduced intraneuronal cholesterol and GSL storage as well as free sphingosine accumulation, reduced markers of neurodegeneration, and led to longer survival than any previous treatment regime. We reasoned that other lysosomal diseases characterized by cholesterol and GSL accumulation, including NPC disease due to NPC2 deficiency, GM1 gangliosidosis and mucopolysaccharidosis (MPS type IIIA, might likewise benefit from CD treatment. Treated Npc2(-/- mice showed benefits similar to NPC1 disease, however, mice with GM1 gangliosidosis or MPS IIIA failed to show reduction in storage.Treatment with CD delayed clinical disease onset, reduced intraneuronal storage and secondary markers of neurodegeneration, and significantly increased lifespan of both Npc1(-/- and Npc2(-/- mice. In contrast, CD failed to ameliorate cholesterol or glycosphingolipid storage in GM1 gangliosidosis and MPS IIIA disease. Understanding the mechanism(s by which CD leads to reduced neuronal storage may provide important new opportunities for treatment of NPC and related neurodegenerative diseases characterized by cholesterol dyshomeostasis.

  16. A specific type of membrane microdomains is involved in the maintenance and translocation of kinase active Lck to lipid rafts

    Czech Academy of Sciences Publication Activity Database

    Ballek, Ondřej; Broučková, Adéla; Manning, Jasper; Filipp, Dominik

    2012-01-01

    Roč. 142, 1-2 (2012), s. 64-74 ISSN 0165-2478 R&D Projects: GA ČR GA310/09/2084 Institutional research plan: CEZ:AV0Z50520514 Keywords : pY394Lck * T-cell proximal signaling * membrane microdomains Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.337, year: 2012

  17. Cytoskeletal Components Define Protein Location to Membrane Microdomains*

    Science.gov (United States)

    Szymanski, Witold G.; Zauber, Henrik; Erban, Alexander; Gorka, Michal; Wu, Xu Na; Schulze, Waltraud X.

    2015-01-01

    The plasma membrane is an important compartment that undergoes dynamic changes in composition upon external or internal stimuli. The dynamic subcompartmentation of proteins in ordered low-density (DRM) and disordered high-density (DSM) membrane phases is hypothesized to require interactions with cytoskeletal components. Here, we systematically analyzed the effects of actin or tubulin disruption on the distribution of proteins between membrane density phases. We used a proteomic screen to identify candidate proteins with altered submembrane location, followed by biochemical or cell biological characterization in Arabidopsis thaliana. We found that several proteins, such as plasma membrane ATPases, receptor kinases, or remorins resulted in a differential distribution between membrane density phases upon cytoskeletal disruption. Moreover, in most cases, contrasting effects were observed: Disruption of actin filaments largely led to a redistribution of proteins from DRM to DSM membrane fractions while disruption of tubulins resulted in general depletion of proteins from the membranes. We conclude that actin filaments are necessary for dynamic movement of proteins between different membrane phases and that microtubules are not necessarily important for formation of microdomains as such, but rather they may control the protein amount present in the membrane phases. PMID:26091700

  18. Expression of ceramide glucosyltransferases, which are essential for glycosphingolipid synthesis, is only required in a small subset of C. elegans cells

    DEFF Research Database (Denmark)

    Marza, Esther; Simonsen, Karina T; Færgeman, Nils J

    2009-01-01

    mutants with essentially no GSLs. The C. elegans genome encodes three ceramide glucosyltransferase (CGT) genes, which encode enzymes required for GSL biosynthesis. Animals lacking CGT do not synthesize GSLs, arrest growth at the first larval stage, and display defects in a subset of cells...... suggest that GSLs are dispensable in most C. elegans cells, including those of the nervous system.......Glycosphingolipids (GSLs) are glycosylated derivatives of ceramide in the lipid bilayer. Their ubiquitous distribution and complexity suggest that they have important functions, but what these are in vivo is still poorly understood. Here, we characterize the phenotype of Caenorhabditis elegans...

  19. ADAPTIVE OPTICS IMAGING OF A MASSIVE GALAXY ASSOCIATED WITH A METAL-RICH ABSORBER

    International Nuclear Information System (INIS)

    Chun, Mark R.; Kulkarni, Varsha P.; Gharanfoli, Soheila; Takamiya, Marianne

    2010-01-01

    The damped and sub-damped Lyα absorption (DLA and sub-DLA) line systems in quasar spectra are believed to be produced by intervening galaxies. However, the connection of quasar absorbers to galaxies is not well-understood, since attempts to image the absorbing galaxies have often failed. While most DLAs appear to be metal poor, a population of metal-rich absorbers, mostly sub-DLAs, has been discovered in recent studies. Here we report high-resolution K-band imaging with the Keck laser guide star adaptive optics (LGSAO) system of the field of quasar SDSSJ1323-0021 in search of the galaxy producing the z = 0.72 sub-DLA absorber. With a metallicity of 2-4 times the solar level, this absorber is one of the most metal-rich systems found to date. Our data show a large bright galaxy with an angular separation of only 1.''25 from the quasar, well-resolved from the quasar at the high resolution of our data. The galaxy has a magnitude of K = 17.6-17.9, which corresponds to a luminosity of ∼3-6 L*. Morphologically, the galaxy is fitted with a model with an effective radius, enclosing half of the total light, of R e = 4 kpc and a bulge-to-total ratio of 0.4-1.0, indicating a substantial bulge stellar population. Based on the mass-metallicity relation of nearby galaxies, the absorber galaxy appears to have a stellar mass of ∼>10 11 M sun . Given the small impact parameter (9.0 kpc at the absorber redshift), this massive galaxy appears to be responsible for the metal-rich sub-DLA. The absorber galaxy is consistent with the metallicity-luminosity relation observed for nearby galaxies, but is near the upper end of metallicity. Our study marks the first application of LGSAO for the study of the structure of galaxies producing distant quasar absorbers. Finally, this study offers the first example of a massive galaxy with a substantial bulge producing a metal-rich absorber.

  20. An analysis of the magnetic resonance imaging and pathology of intracal lymphoplasmacyte-rich meningioma

    International Nuclear Information System (INIS)

    Liu Jianli; Zhou Junlin; Ma Yongheng; Dong Chi

    2012-01-01

    Objective: To discuss the MRI features of the intracranial lymphoplasmacyte-rich meningioma and the correlation between the MRI features and pathology. Methods: Review retrospectively the MRI and pathologic data of seven patients with lymphoplasmacyte-rich meningioma which were confirmed by surgery and pathology. Results: The seven cases of lymphoplasmacyte-rich meningioma were solitary, six cases demonstrated flat growth along the meninges, five cases had not yet formed specific nodules, and two cases exhibited irregular lobulation. Seven cases had no clear boundary, peritumoral brain edema was obvious and adjacent brain tissues were invaded to varying degrees. After plain MRI scans, the focuses of seven cases exhibited lower-isointense signal in T1WI, five cases revealed higher-isointense signal and two cases showed lower-isointense signal in T2WI. Enhancement scans demonstrated marked enhancement in seven cases, and the meninges in six cases thicken irregularly and extensively. Pathology showed the richness and diversity of cells, an infiltration containing plasma cells and lymphocytes, as well as the unequal areas of neoplastic spindle cells and meninge epithelial cells. Conclusion: Lymphoplasmacyte-rich meningioma is a subtype meningioma of WHO I-grade, which is seldom seen and whose imaging appearances are varied from ordinary meningioma. Its features include growing flat along the meninges, irregular forms, unclear boundary, obvious edema, notable strengthening effect, usual invasion of adjacent brain tissues, and similar inflammation.

  1. A new approach to the modification of cell membrane glycosphingolipids: Ganglioside composition of JTC-12 P3 cells altered by feeding with galactose as a sole carbohydrate source in protein- and lipid-free synthetic medium

    International Nuclear Information System (INIS)

    Kawaguchi, Tatsuya; Takaoka, Toshiko; Yoshida, Eiko; Iwamori, Masao; Nagai, Yoshitaka; Takatsuki, Kiyoshi

    1988-01-01

    A significant difference in the glycosphingolipid composition of JTC-12 P3 cells established from monkey kidney tissue was observed when cells cultured in a protein- and lipid-free synthetic medium containing glucose (DM-160) as a sole carbohydrate source were transferred and cultured in the same medium containing galactose and pyruvic acid (DM-170) in place of glucose. In particular, the amounts of gangliosides GM3, GM2, and GD3 in the cells cultured in DM-170 were 5.3-, 17.8-, and more than 8-fold those in the cells cultured in DM-160, respectively, indicating that anabolism of gangliosides is greatly enhanced in cells cultured in the presence of galactose and pyruvic acid, as compared with cells cultured in the presence of glucose. In fact, after cultivation of cells in the medium with N-acetyl-D-[ 14 C]mannosamine for 96 h, the radioactivity incorporated into the gangliosides of the cells in DM-170 was 10-fold that of the cells in DM-160. Among the gangliosides of the cells in DM-170, highly sialylated molecules such as GD3, GD1a, GD1b, and GT1b were preferentially labeled, indicating that the sialytransferases responsible for the synthesis of gangliosides are significantly more activated in cells cultured in DM-170 than in DM-160. These observations reveal that the glycosphingolipid composition of the plasma membrane can be modified epigenetically under well-defined conditions and provide important clues for clarifying the roles of glycosphingolipids associated with particular cell functions

  2. Low gray scale values of computerized images of carotid plaques associated with increased levels of triglyceride-rich lipoproteins and with increased plaque lipid content

    DEFF Research Database (Denmark)

    Grønholdt, Marie-Louise M.; Nordestgaard, Børge; Weibe, Britt M.

    1997-01-01

    Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content......Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content...

  3. KSHV cell attachment sites revealed by ultra sensitive tyramide signal amplification (TSA) localize to membrane microdomains that are up-regulated on mitotic cells.

    Science.gov (United States)

    Garrigues, H Jacques; Rubinchikova, Yelena E; Rose, Timothy M

    2014-03-01

    Cell surface structures initiating attachment of Kaposi's sarcoma-associated herpesvirus (KSHV) were characterized using purified hapten-labeled virions visualized by confocal microscopy with a sensitive fluorescent enhancement using tyramide signal amplification (TSA). KSHV attachment sites were present in specific cellular domains, including actin-based filopodia, lamellipodia, ruffled membranes, microvilli and intercellular junctions. Isolated microdomains were identified on the dorsal surface, which were heterogeneous in size with a variable distribution that depended on cellular confluence and cell cycle stage. KSHV binding domains ranged from scarce on interphase cells to dense and continuous on mitotic cells, and quantitation of bound virus revealed a significant increase on mitotic compared to interphase cells. KSHV also bound to a supranuclear domain that was distinct from microdomains in confluent and interphase cells. These results suggest that rearrangement of the cellular membrane during mitosis induces changes in cell surface receptors implicated in the initial attachment stage of KSHV entry. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Palmitoylated claudin7 captured in glycolipid-enriched membrane microdomains promotes metastasis via associated transmembrane and cytosolic molecules

    OpenAIRE

    Thuma, Florian; Heiler, Sarah; Schn?lzer, Martina; Z?ller, Margot

    2016-01-01

    In epithelial cells claudin7 (cld7) is a major component of tight junctions, but is also recovered from glycolipid-enriched membrane microdomains (GEM). In tumor cells, too, cld7 exists in two stages. Only GEM-located cld7, which is palmitoylated, promotes metastasis. Searching for the underlying mechanism(s) revealed the following. The metastatic capacity of the rat pancreatic adenocarcinoma cell line ASML is lost by a knockdown (kd) of cld7 and is not regained by rescuing cld7 with a mutate...

  5. A genetically encoded ratiometric sensor to measure extracellular pH in microdomains bounded by basolateral membranes of epithelial cells.

    Science.gov (United States)

    Urra, Javier; Sandoval, Moisés; Cornejo, Isabel; Barros, L Felipe; Sepúlveda, Francisco V; Cid, L Pablo

    2008-10-01

    Extracellular pH, especially in relatively inaccessible microdomains between cells, affects transport membrane protein activity and might have an intercellular signaling role. We have developed a genetically encoded extracellular pH sensor capable of detecting pH changes in basolateral spaces of epithelial cells. It consists of a chimerical membrane protein displaying concatenated enhanced variants of cyan fluorescence protein (ECFP) and yellow fluorescence protein (EYFP) at the external aspect of the cell surface. The construct, termed pHCECSensor01, was targeted to basolateral membranes of Madin-Darby canine kidney (MDCK) cells by means of a sequence derived from the aquaporin AQP4. The fusion of pH-sensitive EYFP with pH-insensitive ECFP allows ratiometric pH measurements. The titration curve of pHCECSensor01 in vivo had a pK (a) value of 6.5 +/- 0.04. Only minor effects of extracellular chloride on pHCECSensor01 were observed around the physiological concentrations of this anion. In MDCK cells, the sensor was able to detect changes in pH secondary to H(+) efflux into the basolateral spaces elicited by an ammonium prepulse or lactate load. This genetically encoded sensor has the potential to serve as a noninvasive tool for monitoring changes in extracellular pH microdomains in epithelial and other tissues in vivo.

  6. Developments on RICH detectors

    International Nuclear Information System (INIS)

    Besson, P.; Bourgeois, P.

    1996-01-01

    The RICH (ring imaging Cherenkov) detector which is dedicated to Cherenkov radiation detection is described. An improvement made by replacing photo sensible vapor with solid photocathode is studied. A RICH detector prototype with a CsI photocathode has been built in Saclay and used with Saturne. The first results are presented. (A.C.)

  7. Interaction of AnxA6 with isolated and artificial lipid microdomains; importance of lipid composition and calcium content.

    Science.gov (United States)

    Domon, Magdalena M; Besson, Françoise; Tylki-Szymanska, Anna; Bandorowicz-Pikula, Joanna; Pikula, Slawomir

    2013-04-05

    Niemann-Pick type C (NPC) disease is a lipid storage disorder characterized by accumulation of lipids in the late endosome/lysosome (LE/LY) compartment. In our previous report we isolated membranes of the LE/LY compartment from NPC L1 skin fibroblasts with a mutation in the NPC1 gene and found that they were characterized by low fluidity which likely contributed to the impaired function of membrane proteins involved in storage and turnover of cholesterol. In this report we isolated lipid microdomains (DRMs) from membranes of various cellular compartments and observed an increased amount of DRMs in the LE/LY compartment of NPC L1 cells in comparison to control cells, with no change in the DRM content in the plasma membrane. In addition, in the NPC cells, the majority of the cholesterol-interacting protein, AnxA6, which participates in the transport and distribution of cholesterol, translocated to DRMs upon a rise in Ca(2+) concentration. The mechanism of this translocation was further studied in vitro using Langmuir monolayers. We found that Ca(2+) is the main factor which regulates the interaction of AnxA6 with monolayers composed of neutral lipids, such as DPPC and sphingomyelin, and may also determine AnxA6 localization in cholesterol and sphingomyelin enriched microdomains, thus contributing to the etiology of the NPC disease.

  8. Microstructural heterogeneity directs micromechanics and mechanobiology in native and engineered fibrocartilage

    Science.gov (United States)

    Han, Woojin M.; Heo, Su-Jin; Driscoll, Tristan P.; Delucca, John F.; McLeod, Claire M.; Smith, Lachlan J.; Duncan, Randall L.; Mauck, Robert L.; Elliott, Dawn M.

    2016-04-01

    Treatment strategies to address pathologies of fibrocartilaginous tissue are in part limited by an incomplete understanding of structure-function relationships in these load-bearing tissues. There is therefore a pressing need to develop micro-engineered tissue platforms that can recreate the highly inhomogeneous tissue microstructures that are known to influence mechanotransductive processes in normal and diseased tissue. Here, we report the quantification of proteoglycan-rich microdomains in developing, ageing and diseased fibrocartilaginous tissues, and the impact of these microdomains on endogenous cell responses to physiologic deformation within a native-tissue context. We also developed a method to generate heterogeneous tissue-engineered constructs (hetTECs) with non-fibrous proteoglycan-rich microdomains engineered into the fibrous structure, and show that these hetTECs match the microstructural, micromechanical and mechanobiological benchmarks of native tissue. Our tissue-engineered platform should facilitate the study of the mechanobiology of developing, homeostatic, degenerating and regenerating fibrous tissues.

  9. Coronavirus and influenza virus proteolytic priming takes place in tetraspanin-enriched membrane microdomains.

    Science.gov (United States)

    Earnest, James T; Hantak, Michael P; Park, Jung-Eun; Gallagher, Tom

    2015-06-01

    Coronaviruses (CoVs) and low-pathogenicity influenza A viruses (LP IAVs) depend on target cell proteases to cleave their viral glycoproteins and prime them for virus-cell membrane fusion. Several proteases cluster into tetraspanin-enriched microdomains (TEMs), suggesting that TEMs are preferred virus entry portals. Here we found that several CoV receptors and virus-priming proteases were indeed present in TEMs. Isolated TEMs, when mixed with CoV and LP IAV pseudoparticles, cleaved viral fusion proteins to fusion-primed fragments and potentiated viral transductions. That entering viruses utilize TEMs as a protease source was further confirmed using tetraspanin antibodies and tetraspanin short hairpin RNAs (shRNAs). Tetraspanin antibodies inhibited CoV and LP IAV infections, but their virus-blocking activities were overcome by expressing excess TEM-associated proteases. Similarly, cells with reduced levels of the tetraspanin CD9 resisted CoV pseudoparticle transductions but were made susceptible by overproducing TEM-associated proteases. These findings indicated that antibodies and CD9 depletions interfere with viral proteolytic priming in ways that are overcome by surplus proteases. TEMs appear to be exploited by some CoVs and LP IAVs for appropriate coengagement with cell receptors and proteases. Enveloped viruses use their surface glycoproteins to catalyze membrane fusion, an essential cell entry step. Host cell components prime these viral surface glycoproteins to catalyze membrane fusion at specific times and places during virus cell entry. Among these priming components are proteases, which cleave viral surface glycoproteins, unleashing them to refold in ways that catalyze virus-cell membrane fusions. For some enveloped viruses, these proteases are known to reside on target cell surfaces. This research focuses on coronavirus and influenza A virus cell entry and identifies TEMs as sites of viral proteolysis, thereby defining subcellular locations of virus

  10. Specific chlamydial inclusion membrane proteins associate with active Src family kinases in microdomains that interact with the host microtubule network.

    Science.gov (United States)

    Mital, Jeffrey; Miller, Natalie J; Fischer, Elizabeth R; Hackstadt, Ted

    2010-09-01

    Chlamydiae are Gram-negative obligate intracellular bacteria that cause diseases with significant medical and economic impact. Chlamydia trachomatis replicates within a vacuole termed an inclusion, which is extensively modified by the insertion of a number of bacterial effector proteins known as inclusion membrane proteins (Incs). Once modified, the inclusion is trafficked in a dynein-dependent manner to the microtubule-organizing centre (MTOC), where it associates with host centrosomes. Here we describe a novel structure on the inclusion membrane comprised of both host and bacterial proteins. Members of the Src family of kinases are recruited to the chlamydial inclusion in an active form. These kinases display a distinct, localized punctate microdomain-like staining pattern on the inclusion membrane that colocalizes with four chlamydial inclusion membrane proteins (Incs) and is enriched in cholesterol. Biochemical studies show that at least two of these Incs stably interact with one another. Furthermore, host centrosomes associate with these microdomain proteins in C. trachomatis-infected cells and in uninfected cells exogenously expressing one of the chlamydial effectors. Together, the data suggest that a specific structure on the C. trachomatis inclusion membrane may be responsible for the known interactions of chlamydiae with the microtubule network and resultant effects on centrosome stability.

  11. Membrane mobility and microdomain association of the dopaminetransporter studied with fluorescence correlation spectroscopy and fluorescence recovery after photobleaching

    DEFF Research Database (Denmark)

    Adkins, Erika; Samuvel, Devadoss; Fog, Jacob

    2007-01-01

    To investigate microdomain association of the dopamine transporter (DAT), we employed FCS (fluorescence correlation spectroscopy) and FRAP (fluorescence recovery after photobleaching). In non-neuronal cells (HEK293), FCS measurements revealed for the YFP-DAT (DAT tagged with yellow fluorescent...... protein) a diffusion coefficient (D) of ~3.6 × 10-9 cm2/s, consistent with a relatively freely diffusible protein. In neuronally derived cells (N2a), we were unable to perform FCS measurements on plasma membrane-associated protein due to photobleaching, suggesting partial immobilization...

  12. Persistence at low temperature of the P beta' ripple in dipalmitoylphosphatidylcholine multilamellar vesicles containing either glycosphingolipids or cholesterol.

    Science.gov (United States)

    Rock, P; Thompson, T E; Tillack, T W

    1989-03-13

    The disappearance and reappearance of the P beta' ripple in multilamellar liposomes of dipalmitoylphosphatidylcholine (DPPC) has been examined by freeze-etch electron microscopy. The presence of less than 10 mol% of various glycosphingolipids or cholesterol in the liposomes markedly increases the time required for ripple disappearance when the vesicles are cooled from 38 degrees C to 30 degrees C, as compared to the pure phospholipid. Once the ripples have begun to disappear in the two-component vesicles, they do not uniformly reappear until the system is heated above the main transition of DPPC and allowed to cool into the pretransition region. These results suggest that the long time for ripple disappearance in the two-component systems reflects a slow molecular reorganization process which occurs when the systems are forced to change from the P beta' gel to the L beta' gel by a temperature downshift.

  13. Microstructural Heterogeneity in Native and Engineered Fibrocartilage Directs Micromechanics and Mechanobiology

    Science.gov (United States)

    Han, Woojin M; Heo, Su-Jin; Driscoll, Tristan P; Delucca, John F; McLeod, Claire M; Smith, Lachlan J; Duncan, Randall L; Mauck, Robert L; Elliott, Dawn M

    2015-01-01

    Treatment strategies to address pathologies of fibrocartilaginous tissue are in part limited by an incomplete understanding of structure-function relationships in these load-bearing tissues. There is therefore a pressing need to develop microengineered tissue platforms that can recreate the highly inhomogeneous tissue microstructures that are known to influence mechanotransductive processes in normal and diseased tissue. Here, we report the quantification of proteoglycan-rich microdomains in developing, aging, and diseased fibrocartilaginous tissues, and the impact of these microdomains on endogenous cell responses to physiologic deformation within a native-tissue context. We also developed a method to generate heterogeneous tissue engineered constructs (hetTECs) with microscale non-fibrous proteoglycan-rich microdomains engineered into the fibrous structure, and show that these hetTECs match the microstructural, micromechanical, and mechanobiological benchmarks of native tissue. Our tissue engineered platform should facilitate the study of the mechanobiology of developing, homeostatic, degenerating, and regenerating fibrous tissues. PMID:26726994

  14. Chemical Imaging of the Cell Membrane by NanoSIMS

    International Nuclear Information System (INIS)

    Weber, P.K.; Kraft, M.L.; Frisz, J.F.; Carpenter, K.J.; Hutcheon, I.D.

    2010-01-01

    The existence of lipid microdomains and their role in cell membrane organization are currently topics of great interest and controversy. The cell membrane is composed of a lipid bilayer with embedded proteins that can flow along the two-dimensional surface defined by the membrane. Microdomains, known as lipid rafts, are believed to play a central role in organizing this fluid system, enabling the cell membrane to carry out essential cellular processes, including protein recruitment and signal transduction. Lipid rafts are also implicated in cell invasion by pathogens, as in the case of the HIV. Therefore, understanding the role of lipid rafts in cell membrane organization not only has broad scientific implications, but also has practical implications for medical therapies. One of the major limitations on lipid organization research has been the inability to directly analyze lipid composition without introducing artifacts and at the relevant length-scales of tens to hundreds of nanometers. Fluorescence microscopy is widely used due to its sensitivity and specificity to the labeled species, but only the labeled components can be observed, fluorophores can alter the behavior of the lipids they label, and the length scales relevant to imaging cell membrane domains are between that probed by fluorescence resonance energy transfer (FRET) imaging (<10 nm) and the diffraction limit of light. Topographical features can be imaged on this length scale by atomic force microscopy (AFM), but the chemical composition of the observed structures cannot be determined. Immuno-labeling can be used to study the distribution of membrane proteins at high resolution, but not lipid composition. We are using imaging mass spectrometry by secondary ion mass spectrometry (SIMS) in concert with other high resolution imaging methods to overcome these limitations. The experimental approach of this project is to combine molecule-specific stable isotope labeling with high-resolution SIMS using a

  15. Gelation of Photonic Microdomain Structures Formed in Semi-Dilute Solutions of Ultra-High-Molecular-Weight Polystyrene-b-Polybutadiene with Various Polybutadiene Contents

    International Nuclear Information System (INIS)

    Okamoto, S; Ito, S; Ando, K; Mouri, M; Ikeda, A; Hasegawa, H; Koshikawa, N

    2010-01-01

    Well-ordered microdomain structures were obtained in semi-dilute solutions and successfully stabilized by gelation. We used polystyrene-b-polybutadiene (PS-b-PB) diblock copolymer with the weight-averaged molecular weight varying from several hundred thousands to millions g/mol. The solutions had iridescent colors because the domain spacing is on the order of the wavelength of visible light. As the structures are susceptible to distortion by flow or vibration, structural fixation was carried out by gelation. The polybutadiene used has the microstructure of 1,2-linkage and hence the chains can be cross-linkable. The Small-Angle X-ray Scattering and the UV-vis spectroscopic measurements showed that in the case of PS-b-PBs with the PB volume fraction, φ PB , greater than about 50 vol % the microdomain structures were successfully fixed by gelation, while largely distorted in the case of those with φ PB < ca. 50 vol %. The SAXS scattering intensities were quantitatively analyzed by the scattering functions numerically calculated based on the one- and two-dimensional paracrystal theories and on the concentration fluctuation between the polymers and the solvent molecules.

  16. Microvillar membrane microdomains exist at physiological temperature. Role of galectin-4 as lipid raft stabilizer revealed by "superrafts"

    DEFF Research Database (Denmark)

    Braccia, Anita; Villani, Maristella; Immerdal, Lissi

    2003-01-01

    rafts prepared by the two protocols were morphologically different but had essentially similar profiles of protein- and lipid components, showing that raft microdomains do exist at 37 degrees C and are not "low temperature artifacts." We also employed a novel method of sequential detergent extraction...... and the transmembrane aminopeptidase N, whereas the peripheral lipid raft protein annexin 2 was essentially absent. In conclusion, in the microvillar membrane, galectin-4, functions as a core raft stabilizer/organizer for other, more loosely raft-associated proteins. The superraft analysis might be applicable to other...

  17. Biological Roles of Aberrantly Expressed Glycosphingolipids and Related Enzymes in Human Cancer Development and Progression

    Directory of Open Access Journals (Sweden)

    Dinghao Zhuo

    2018-05-01

    Full Text Available Glycosphingolipids (GSLs, which consist of a hydrophobic ceramide backbone and a hydrophilic carbohydrate residue, are an important type of glycolipid expressed in surface membranes of all animal cells. GSLs play essential roles in maintenance of plasma membrane stability, in regulation of numerous cellular processes (including adhesion, proliferation, apoptosis, and recognition, and in modulation of signal transduction pathways. GSLs have traditionally been classified as ganglio-series, lacto-series, or globo-series on the basis of their diverse types of oligosaccharide chains. Structures and functions of specific GSLs are also determined by their oligosaccharide chains. Different cells and tissues show differential expression of GSLs, and changes in structures of GSL glycan moieties occur during development of numerous types of human cancer. Association of GSLs and/or related enzymes with initiation and progression of cancer has been documented in 100s of studies, and many such GSLs are useful markers or targets for cancer diagnosis or therapy. In this review, we summarize (i recent studies on aberrant expression and distribution of GSLs in common human cancers (breast, lung, colorectal, melanoma, prostate, ovarian, leukemia, renal, bladder, gastric; (ii biological functions of specific GSLs in these cancers.

  18. Tetraspanins and Transmembrane Adaptor Proteins As Plasma Membrane Organizers-Mast Cell Case.

    Science.gov (United States)

    Halova, Ivana; Draber, Petr

    2016-01-01

    The plasma membrane contains diverse and specialized membrane domains, which include tetraspanin-enriched domains (TEMs) and transmembrane adaptor protein (TRAP)-enriched domains. Recent biophysical, microscopic, and functional studies indicated that TEMs and TRAP-enriched domains are involved in compartmentalization of physicochemical events of such important processes as immunoreceptor signal transduction and chemotaxis. Moreover, there is evidence of a cross-talk between TEMs and TRAP-enriched domains. In this review we discuss the presence and function of such domains and their crosstalk using mast cells as a model. The combined data based on analysis of selected mast cell-expressed tetraspanins [cluster of differentiation (CD)9, CD53, CD63, CD81, CD151)] or TRAPs [linker for activation of T cells (LAT), non-T cell activation linker (NTAL), and phosphoprotein associated with glycosphingolipid-enriched membrane microdomains (PAG)] using knockout mice or specific antibodies point to a diversity within these two families and bring evidence of the important roles of these molecules in signaling events. An example of this diversity is physical separation of two TRAPs, LAT and NTAL, which are in many aspects similar but show plasma membrane location in different microdomains in both non-activated and activated cells. Although our understanding of TEMs and TRAP-enriched domains is far from complete, pharmaceutical applications of the knowledge about these domains are under way.

  19. Tetraspanins and Transmembrane Adaptor Proteins as Plasma Membrane Organizers – Mast Cell Case

    Directory of Open Access Journals (Sweden)

    Ivana eHalova

    2016-05-01

    Full Text Available The plasma membrane contains diverse and specialized membrane domains, which include tetraspanin-enriched domains (TEMs and transmembrane adaptor protein (TRAP-enriched domains. Recent biophysical, microscopic and functional studies indicated that TEMs and TRAP-enriched domains are involved in compartmentalization of physicochemical events of such important processes as immunoreceptor signal transduction and chemotaxis. Moreover, there is evidence of a cross-talk between TEMs and TRAP-enriched domains. In this review we discuss the presence and function of such domains and their crosstalk using mast cells as a model. The combined data based on analysis of selected mast cell-expressed tetraspanins [cluster of differentiation (CD9, CD53, CD63, CD81, CD151] or TRAPs [linker for activation of T cells (LAT, non-T cell activation linker (NTAL, and phosphoprotein associated with glycosphingolipid-enriched membrane microdomains (PAG] using knockout mice or specific antibodies point to a diversity within these two families and bring evidence of the important roles of these molecules in signaling events. An example of this diversity is physical separation of two TRAPs, LAT and NTAL, which are in many aspects similar but show plasma membrane location in different microdomains in both non-activated and activated cells. Although our understanding of TEMs and TRAP-enriched domains is far from complete, pharmaceutical applications of the knowledge about these domains are under way.

  20. A novel negative regulatory function of the phosphoprotein associated with glycosphingolipid-enriched microdomains: blocking Ras activation

    Czech Academy of Sciences Publication Activity Database

    Smida, M.; Posevitz-Fejfar, A.; Hořejší, Václav; Schraven, B.; Lindquist, J.A.

    2007-01-01

    Roč. 110, č. 2 (2007), s. 596-605 ISSN 0006-4971 R&D Projects: GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : PAG * Ras * lipid rafts Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.896, year: 2007

  1. Image-Rich Radiology Reports: A Value-Based Model to Improve Clinical Workflow.

    Science.gov (United States)

    Patel, Bhavik N; Lopez, Jose M; Jiang, Brian G; Roth, Christopher J; Nelson, Rendon C

    2017-01-01

    To determine the value of image-rich radiology reports (IRRR) by evaluating the interest and preferences of referring physicians, potential impact on clinical workflow, and the willingness of radiologists to create them. Referring physicians and radiologists were interviewed in this prospective, HIPAA-compliant study. Subject willingness to participate in the study was determined by an e-mail. A single investigator conducted all interviews using a standard questionnaire. All subjects reviewed a video mockup demonstration of IRRR and three methods for viewing embedded images, as follows: (1) clickable hyperlinks to access a scrollable stack of images, (2) scrollable and enlargeable small-image thumbnails, and (3) scrollable but not enlargeable medium-sized images. Questionnaire responses, free comments, and general impressions were captured and analyzed. Seventy-two physicians (36 clinicians, 36 radiologists) were interviewed. Thirty-one clinicians (86%) expressed interest in using IRRR. Seventy-seven percent of subjects believed IRRR would improve communication. Ten clinicians (28%) preferred method 1, 18 (50%) preferred method 2, and 8 (22%) preferred method 3 for embedding images. Thirty clinicians (83%) stated that IRRR would improve efficiency. Twenty-two radiologists (61%) preferred selecting a tool button with a mouse and right-clicking images to embed them, 13 (36%) preferred pressing a function key, and 11 (31%) preferred dictating series and image numbers. The average time radiologists were willing to expend for embedding images was 66.7 seconds. Referring physicians and radiologist both believe IRRR would add value by improving communication with the potential to improve the workflow efficiency of referring physicians. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  2. Membrane mobility and microdomain association of the dopamine transporter studied with fluorescence correlation spectroscopy and fluorescence recovery after photobleaching

    DEFF Research Database (Denmark)

    Adkins, Erika M; Samuvel, Devadoss J; Fog, Jacob U

    2007-01-01

    To investigate microdomain association of the dopamine transporter (DAT), we employed FCS (fluorescence correlation spectroscopy) and FRAP (fluorescence recovery after photobleaching). In non-neuronal cells (HEK293), FCS measurements revealed for the YFP-DAT (DAT tagged with yellow fluorescent...... protein) a diffusion coefficient (D) of approximately 3.6 x 10(-9) cm2/s, consistent with a relatively freely diffusible protein. In neuronally derived cells (N2a), we were unable to perform FCS measurements on plasma membrane-associated protein due to photobleaching, suggesting partial immobilization...

  3. A fluorescent glycolipid-binding peptide probe traces cholesterol dependent microdomain-derived trafficking pathways.

    Directory of Open Access Journals (Sweden)

    Steffen Steinert

    Full Text Available BACKGROUND: The uptake and intracellular trafficking of sphingolipids, which self-associate into plasma membrane microdomains, is associated with many pathological conditions, including viral and toxin infection, lipid storage disease, and neurodegenerative disease. However, the means available to label the trafficking pathways of sphingolipids in live cells are extremely limited. In order to address this problem, we have developed an exogenous, non-toxic probe consisting of a 25-amino acid sphingolipid binding domain, the SBD, derived from the amyloid peptide Abeta, and conjugated by a neutral linker with an organic fluorophore. The current work presents the characterization of the sphingolipid binding and live cell trafficking of this novel probe, the SBD peptide. SBD was the name given to a motif originally recognized by Fantini et al in a number of glycolipid-associated proteins, and was proposed to interact with sphingolipids in membrane microdomains. METHODOLOGY/PRINCIPAL FINDINGS: In accordance with Fantini's model, optimal SBD binding to membranes depends on the presence of sphingolipids and cholesterol. In synthetic membrane binding assays, SBD interacts preferentially with raft-like lipid mixtures containing sphingomyelin, cholesterol, and complex gangliosides in a pH-dependent manner, but is less glycolipid-specific than Cholera toxin B (CtxB. Using quantitative time-course colocalization in live cells, we show that the uptake and intracellular trafficking route of SBD is unlike that of either the non-raft marker Transferrin or the raft markers CtxB and Flotillin2-GFP. However, SBD traverses an endolysosomal route that partially intersects with raft-associated pathways, with a major portion being diverted at a late time point to rab11-positive recycling endosomes. Trafficking of SBD to acidified compartments is strongly disrupted by cholesterol perturbations, consistent with the regulation of sphingolipid trafficking by cholesterol

  4. Lamellar Microdomains of Block-Copolymer-Based Ionic Supramolecules Exhibiting a Hierarchical Self-Assembly

    DEFF Research Database (Denmark)

    Ayoubi, Mehran Asad; Almdal, Kristoffer; Zhu, Kaizheng

    2014-01-01

    (Cn; n = 8, 12, and 16) trimethylammonium counterions (i.e., side chains) at various ion (pair) fractions X [i.e., counterion/side-chain grafting density; X = number of alkyl counterions (i.e., side chains) per acidic group of the parent PMAA block] these L-b-AC ionic supramolecules exhibit...... a spherical-in-lamellar hierarchical self-assembly. For these systems, (1) the effective Flory-Huggins interaction parameter between L- and AC-blocks chi'(Cn/x) was extracted, and (2) analysis of the lamellar microdomains showed that when there is an increase in X, alkyl counterion (i.e., side chain) length l......Based on a parent diblock copolymer of poly(styrene)-b-poly(methacrylic acid), PS-b-PMAA, linear-b-amphiphilic comb (L-b-AC) ionic supramolecules [Soft Matter 2013, 9, 1540-1555] are synthesized in which the poly(methacrylate) backbone of the ionic supramolecular AC-block is neutralized by alkyl...

  5. Molecular imaging of lipids in cells and tissues

    Science.gov (United States)

    Borner, Katrin; Malmberg, Per; Mansson, Jan-Eric; Nygren, Hakan

    2007-02-01

    The distribution pattern of lipid species in biological tissues was analyzed with imaging mass spectrometry (TOF-SIMS; time-of-flight secondary ion mass spectrometry). The first application shows distribution of a glycosphingolipid, the galactosylceramide-sulfate (sulfatide) with different hydrocarbon chain lengths and the fatty acids palmitate and oleate in rat cerebellum. Sulfatides were seen localized in regions suggested as paranodal areas of rat cerebellar white matter as well as in the granular layer, with highest concentrations at the borders of the white matter. Different distribution patterns could be shown for the fatty acid C16:0 palmitate and C18:1 oleate in rat cerebellum, which seem to origin partly from the hydrocarbon chains of phosphatidylcholine. Results were shown for two different tissue preparation methods, which were plunge-freezing and cryostat sectioning as well as high-pressure freezing, freeze-fracturing and freeze-drying. The second application shows TOF-SIMS analysis on a biological trial of choleratoxin treatment in mouse intestine. The effect of cholera toxin on lipids in the intestinal epithelium was shown by comparing control and cholera toxin treated mouse intestine samples. A significant increase of the cholesterol concentration was seen after treatment. Cholesterol was mainly localized to the brush border of enterocytes of the intestinal villi, which could be explained by the presence of cholesterol-rich lipid rafts present on the microvilli or by relations to cholesterol uptake. After cholera toxin exposure, cholesterol was seen increased in the nuclei of enterocytes and apparently in the interstitium of the villi. We find that imaging TOF-SIMS is a powerful tool for studies of lipid distributions in cells and tissues, enabling the elucidation of their role in cell function and biology.

  6. Electron transfer at boron-doped diamond electrodes modified by graphitic micro-domains

    Energy Technology Data Exchange (ETDEWEB)

    Mahe, E.; Devilliers, D. [Pierre et Marie Curie Univ., Paris (France). Electrochemistry Lab.; Comninellis, C. [Lausanne Ecole Polytechnique, Lausanne (Switzerland). Groupe de Genie Electrochimique

    2006-07-01

    Boron-doped (BDD) electrodes have been used in electrolysis procedures for the last 10 years. The mechanical stability of the electrode, its large electrochemical window and its low capacitive current place this new electrode material as an alternative for replacing more costly or toxic materials such as mercury. However, the ferri/ferrocyanide system of boron-doped electrodes has shown contradictory results in the literature. This study proposed a cathodic pre-treatment which relied on the presence of residual graphitic domains formed during the preparation of the BDD film. An experiment was conducted in which the doping procedure was used to control the amount of graphitic phase on the electrode with highly oriented pyrolytic graphite (HOPG) grafted on the BDD surface. Surface characterization with Raman spectroscopy and Scanning Electron Microscopy (SEM) was then carried out using cyclic voltammetry and electrochemical impedance spectroscopy. The electroanalytical determination of the amount of graphitic micro-domains was described and a pulse procedure was proposed which obtained a reproducible surface state. 2 refs., 2 figs.

  7. The assembly of GM1 glycolipid- and cholesterol-enriched raft-like membrane microdomains is important for giardial encystation.

    Science.gov (United States)

    De Chatterjee, Atasi; Mendez, Tavis L; Roychowdhury, Sukla; Das, Siddhartha

    2015-05-01

    Although encystation (or cyst formation) is an important step of the life cycle of Giardia, the cellular events that trigger encystation are poorly understood. Because membrane microdomains are involved in inducing growth and differentiation in many eukaryotes, we wondered if these raft-like domains are assembled by this parasite and participate in the encystation process. Since the GM1 ganglioside is a major constituent of mammalian lipid rafts (LRs) and known to react with cholera toxin B (CTXB), we used Alexa Fluor-conjugated CTXB and GM1 antibodies to detect giardial LRs. Raft-like structures in trophozoites are located in the plasma membranes and on the periphery of ventral discs. In cysts, however, they are localized in the membranes beneath the cyst wall. Nystatin and filipin III, two cholesterol-binding agents, and oseltamivir (Tamiflu), a viral neuraminidase inhibitor, disassembled the microdomains, as evidenced by reduced staining of trophozoites with CTXB and GM1 antibodies. GM1- and cholesterol-enriched LRs were isolated from Giardia by density gradient centrifugation and found to be sensitive to nystatin and oseltamivir. The involvement of LRs in encystation could be supported by the observation that raft inhibitors interrupted the biogenesis of encystation-specific vesicles and cyst production. Furthermore, culturing of trophozoites in dialyzed medium containing fetal bovine serum (which is low in cholesterol) reduced raft assembly and encystation, which could be rescued by adding cholesterol from the outside. Our results suggest that Giardia is able to form GM1- and cholesterol-enriched lipid rafts and these raft domains are important for encystation. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Mass spectrometry of fluorocarbon-labeled glycosphingolipids

    DEFF Research Database (Denmark)

    Li, Yunsen; Arigi, Emma; Eichert, Heather

    2010-01-01

    ceramide N-deacylase (SCDase) is used to remove the fatty acid from the ceramide moiety, after which a fluorocarbon-rich substituent (F-Tag) is incorporated at the free amine of the sphingoid. In initial trials, a neutral GSL, globotriaosylceramide (Gb(3)Cer), three purified bovine brain gangliosides...... with subsequent per-N,O-methylation was established for the F-tagged Gb(3) Cer and purified gangliosides, and extensive mass spectra (MS(1) and MS(2)) consistent with all of the expected products were acquired. The potential use of F-tagged derivatives for a comprehensive MS based profiling application...

  9. cGMP Signaling in the Cardiovascular System—The Role of Compartmentation and Its Live Cell Imaging

    Science.gov (United States)

    Bork, Nadja I.; Nikolaev, Viacheslav O.

    2018-01-01

    The ubiquitous second messenger 3′,5′-cyclic guanosine monophosphate (cGMP) regulates multiple physiologic processes in the cardiovascular system. Its intracellular effects are mediated by stringently controlled subcellular microdomains. In this review, we will illustrate the current techniques available for real-time cGMP measurements with a specific focus on live cell imaging methods. We will also discuss currently accepted and emerging mechanisms of cGMP compartmentation in the cardiovascular system. PMID:29534460

  10. Modeling broad-scale patterns of avian species richness across the Midwestern United States with measures of satellite image texture

    Science.gov (United States)

    Patrick D. Culbert; Volker C. Radeloff; Veronique St-Louis; Curtis H. Flather; Chadwick D. Rittenhouse; Thomas P. Albright; Anna M. Pidgeon

    2012-01-01

    Avian biodiversity is threatened, and in order to prioritize limited conservation resources and conduct effective conservation planning a better understanding of avian species richness patterns is needed. The use of image texture measures, as a proxy for the spatial structure of land cover and vegetation, has proven useful in explaining patterns of avian abundance and...

  11. LHCb RICH1 Engineering Design Review Report

    CERN Document Server

    Brook, N; Metlica, F; Muir, A; Phillips, A; Buckley, A; Gibson, V; Harrison, K; Jones, C R; Katvars, S G; Lazzeroni, C; Storey, J; Ward, CP; Wotton, S; Alemi, M; Arnabaldi, C; Bellunato, T F; Calvi, M; Matteuzzi, C; Musy, M; Negri, P; Perego, D L; Pessina, G; Chamonal, R; Eisenhardt, S; Lawrence, J; McCarron, J; Muheim, F; Playfer, S; Walker, A; Cuneo, S; Fontanelli, F; Gracco, Valerio; Mini, G; Musico, P; Petrolini, A; Sannino, M; Bates, A; MacGregor, A; O'Shea, V; Parkes, C; Paterson, S; Petrie, D; Pickford, A; Rahman, M; Soler, F; Allebone, L; Barber, J H; Cameron, W; Clark, D; Dornan, Peter John; Duane, A; Egede, U; Hallam, R; Howard, A; Plackett, R; Price, D; Savidge, T; Vidal-Sitjes, G; Websdale, D M; Adinolfi, M; Bibby, J H; Cioffi, C; Gligorov, Vladimir V; Harnew, N; Harris, F; McArthur, I A; Newby, C; Ottewell, B; Rademacker, J; Senanayake, R; Somerville, L P; Soroko, A; Smale, N J; Topp-Jørgensen, S; Wilkinson, G; Yang, S; Benayoun, M; Khmelnikov, V A; Obraztsov, V F; Densham, C J; Easo, S; Franek, B; Kuznetsov, G; Loveridge, P W; Morrow, D; Morris, JV; Papanestis, A; Patrick, G N; Woodward, M L; Aglieri-Rinella, G; Albrecht, A; Braem, André; Campbell, M; D'Ambrosio, C; Forty, R W; Frei, C; Gys, Thierry; Jamet, O; Kanaya, N; Losasso, M; Moritz, M; Patel, M; Piedigrossi, D; Snoeys, W; Ullaland, O; Van Lysebetten, A; Wyllie, K

    2005-01-01

    This document describes the concepts of the engineering design to be adopted for the upstream Ring Imaging Cherenkov detector (RICH1) of the reoptimized LHCb detector. Our aim is to ensure that coherent solutions for the engineering design and integration for all components of RICH1 are available, before proceeding with the detailed design of these components.

  12. The CBM RICH project

    Energy Technology Data Exchange (ETDEWEB)

    Adamczewski-Musch, J. [GSI Darmstadt (Germany); Becker, K.-H. [University Wuppertal (Germany); Belogurov, S. [ITEP Moscow (Russian Federation); Boldyreva, N. [PNPI Gatchina (Russian Federation); Chernogorov, A. [ITEP Moscow (Russian Federation); Deveaux, C. [University Gießen (Germany); Dobyrn, V. [PNPI Gatchina (Russian Federation); Dürr, M. [University Gießen (Germany); Eom, J. [Pusan National University (Korea, Republic of); Eschke, J. [GSI Darmstadt (Germany); Höhne, C. [University Gießen (Germany); Kampert, K.-H. [University Wuppertal (Germany); Kleipa, V. [GSI Darmstadt (Germany); Kochenda, L. [PNPI Gatchina (Russian Federation); Kolb, B. [GSI Darmstadt (Germany); Kopfer, J. [University Wuppertal (Germany); Kravtsov, P. [PNPI Gatchina (Russian Federation); Lebedev, S.; Lebedeva, E. [University Gießen (Germany); Leonova, E. [PNPI Gatchina (Russian Federation); and others

    2014-12-01

    The Compressed Baryonic Matter (CBM) experiment will study the properties of super dense nuclear matter by means of heavy ion collisions at the future FAIR facility. An integral detector component is a large Ring Imaging Cherenkov detector with CO{sub 2} gas radiator, which will mainly serve for electron identification and pion suppression necessary to access rare dileptonic probes like e{sup +}e{sup −} decays of light vector mesons or J/Ψ. We describe the design of this future RICH detector and focus on results obtained by building a CBM RICH detector prototype tested at CERN-PS.

  13. First Scattered-Light Images of the Gas-Rich Debris Disk Around 49 Ceti

    Science.gov (United States)

    Choquet, Elodie; Milli, Julien; Wahhaj, Zahed; Soummer, Remi; Roberge, Aki; Augereau, Jean-Charles; Booth, Mark; Absil, Olivier; Boccaletti, Anthony; Chen, Christine H.; hide

    2017-01-01

    We present the first scattered-light images of the debris disk around 49 Ceti, a approximately 40 Myr A1 main-sequence star at 59 pc, famous for hosting two massive dust belts as well as large quantities of atomic and molecular gas. The outer disk is revealed in reprocessed archival Hubble Space Telescope NICMOS-F110W images, as well as new coronagraphic H-band images from the Very Large Telescope SPHERE instrument. The disk extends from 1."1 (65 au) to 4." 6 (250 au) and is seen at an inclination of 73 deg, which refines previous measurements at lower angular resolution. We also report no companion detection larger than 3 MJup at projected separations beyond 20 au from the star (0." 34). Comparison between the F110W and H-band images is consistent with a gray color of 49 Ceti's dust, indicating grains larger than approximately greater than 2 micrometers. Our photometric measurements indicate a scattering efficiency/infrared excess ratio of 0.2-0.4, relatively low compared to other characterized debris disks. We find that 49 Ceti presents morphological and scattering properties very similar to the gas-rich HD 131835 system. From our constraint on the disk inclination we find that the atomic gas previously detected in absorption must extend to the inner disk, and that the latter must be depleted of CO gas. Building on previous studies, we propose a schematic view of the system describing the dust and gas structure around 49 Ceti and hypothetical scenarios for the gas nature and origin.

  14. The AMS-02 RICH Imager Prototype - In-Beam Tests with 20 GeV/c per Nucleon Ions -

    CERN Document Server

    Buenerd, M.; Aguilar Benitez, M.; Arruda, L.; Barao, F.; Barrau, A.; Baret, B.; Belmont, E.; Berdugo, J.; Boudoul, G.; Borges, J.; Casadei, D.; Casaus, J.; Delgado, C.; Diaz, C.; Derome, L.; Eraud, L.; Gallin-Martel, L.; Giovacchini, F.; Goncalves, P.; Lanciotti, E.; Laurenti, G.; Malinine, A.; Mana, C.; Marin, J.; Martinez, G.; Menchaca-Rocha, A.; Palomares, C.; Pimenta, M.; Protasov, K.; Sanchez, E.; Seo, E-S.; Sevilla, I.; Torrento, A.; Vargas-Trevino, M.

    2003-01-01

    A prototype of the AMS Cherenkov imager (RICH) has been tested at CERN by means of a low intensity 20 GeV/c per nucleon ion beam obtained by fragmentation of a primary beam of Pb ions. Data have been collected with a single beam setting, over the range of nuclear charges 2

  15. Rotavirus RRV associates with lipid membrane microdomains during cell entry

    International Nuclear Information System (INIS)

    Isa, Pavel; Realpe, Mauricio; Romero, Pedro; Lopez, Susana; Arias, Carlos F.

    2004-01-01

    Rotavirus cell entry is a multistep process, not completely understood, which requires at least four interactions between the virus and cell surface molecules. In this work, we investigated the role of the sphingolipid- and cholesterol-enriched lipid microdomains (rafts) in the entry of rotavirus strain RRV to MA104 cells. We found that ganglioside GM1, integrin subunits α2 and β3, and the heat shock cognate protein 70 (hsc70), all of which have been implicated as rotavirus receptors, are associated with TX-100 and Lubrol WX detergent-resistant membranes (DRMs). Integrin subunits α2 and β3 were found to be particularly enriched in DRMs resistant to lysis by Lubrol WX. When purified RRV particles were incubated with cells at 4 deg. C, about 10% of the total infectious virus was found associated with DRMs, and the DRM-associated virus increased to 37% in Lubrol-resistant membrane domains after 60-min incubation at 37 deg. C. The virus was excluded from DRMs if the cells were treated with methyl-β-cyclodextrin (MβCD). Immunoblot analysis of the viral proteins showed that the virus surface proteins became enriched in DRMs upon incubation at 37 deg. C, being almost exclusively localized in Lubrol-resistant DRMs after 60 min. These data suggest that detergent-resistant membrane domains play an important role in the cell entry of rotaviruses, which could provide a platform to facilitate the efficient interaction of the rotavirus receptors with the virus particle

  16. First Scattered-light Images of the Gas-rich Debris Disk around 49 Ceti

    Energy Technology Data Exchange (ETDEWEB)

    Choquet, Élodie [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Milli, Julien; Wahhaj, Zahed [European Southern Observatory, Alonso de Còrdova 3107, Vitacura, Casilla 19001, Santiago (Chile); Soummer, Rémi; Chen, Christine H.; Debes, John H. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Roberge, Aki [Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Augereau, Jean-Charles [Univ. Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble (France); Booth, Mark [Astrophysikalisches Institut und Universitätssternwarte, Friedrich-Schiller-Universität Jena, Schillergäßchen 2-3, D-07745 Jena (Germany); Absil, Olivier [Space sciences, Technologies and Astrophysics Research (STAR) Institute, Université de Liège, 19 Allée du Six Août, B-4000 Liège (Belgium); Boccaletti, Anthony [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, F-92195 Meudon (France); Burgo, Carlos del, E-mail: echoquet@jpl.nasa.gov [Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro 1, Sta. Ma. Tonantzintla, Puebla (Mexico); and others

    2017-01-10

    We present the first scattered-light images of the debris disk around 49 Ceti, a ∼40 Myr A1 main-sequence star at 59 pc, famous for hosting two massive dust belts as well as large quantities of atomic and molecular gas. The outer disk is revealed in reprocessed archival Hubble Space Telescope NICMOS-F110W images, as well as new coronagraphic H-band images from the Very Large Telescope SPHERE instrument. The disk extends from 1.″1 (65 au) to 4.″6 (250 au) and is seen at an inclination of 73°, which refines previous measurements at lower angular resolution. We also report no companion detection larger than 3 M {sub Jup} at projected separations beyond 20 au from the star (0.″34). Comparison between the F110W and H-band images is consistent with a gray color of 49 Ceti’s dust, indicating grains larger than ≳2 μ m. Our photometric measurements indicate a scattering efficiency/infrared excess ratio of 0.2–0.4, relatively low compared to other characterized debris disks. We find that 49 Ceti presents morphological and scattering properties very similar to the gas-rich HD 131835 system. From our constraint on the disk inclination we find that the atomic gas previously detected in absorption must extend to the inner disk, and that the latter must be depleted of CO gas. Building on previous studies, we propose a schematic view of the system describing the dust and gas structure around 49 Ceti and hypothetical scenarios for the gas nature and origin.

  17. The Human Pathogen Streptococcus pyogenes Releases Lipoproteins as Lipoprotein-rich Membrane Vesicles.

    Science.gov (United States)

    Biagini, Massimiliano; Garibaldi, Manuela; Aprea, Susanna; Pezzicoli, Alfredo; Doro, Francesco; Becherelli, Marco; Taddei, Anna Rita; Tani, Chiara; Tavarini, Simona; Mora, Marirosa; Teti, Giuseppe; D'Oro, Ugo; Nuti, Sandra; Soriani, Marco; Margarit, Immaculada; Rappuoli, Rino; Grandi, Guido; Norais, Nathalie

    2015-08-01

    Bacterial lipoproteins are attractive vaccine candidates because they represent a major class of cell surface-exposed proteins in many bacteria and are considered as potential pathogen-associated molecular patterns sensed by Toll-like receptors with built-in adjuvanticity. Although Gram-negative lipoproteins have been extensively characterized, little is known about Gram-positive lipoproteins. We isolated from Streptococcus pyogenes a large amount of lipoproteins organized in vesicles. These vesicles were obtained by weakening the bacterial cell wall with a sublethal concentration of penicillin. Lipid and proteomic analysis of the vesicles revealed that they were enriched in phosphatidylglycerol and almost exclusively composed of lipoproteins. In association with lipoproteins, a few hypothetical proteins, penicillin-binding proteins, and several members of the ExPortal, a membrane microdomain responsible for the maturation of secreted proteins, were identified. The typical lipidic moiety was apparently not necessary for lipoprotein insertion in the vesicle bilayer because they were also recovered from the isogenic diacylglyceryl transferase deletion mutant. The vesicles were not able to activate specific Toll-like receptor 2, indicating that lipoproteins organized in these vesicular structures do not act as pathogen-associated molecular patterns. In light of these findings, we propose to name these new structures Lipoprotein-rich Membrane Vesicles. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Molecular basis for interaction of Na+/K+-ATPase with other transporters in membrane microdomains of vascular smooth muscle cells

    DEFF Research Database (Denmark)

    Hansen, Anne Kirstine; Matchkov, Vladimir; Bouzinova, Elena

    2008-01-01

    Ouabain, a specific inhibitor of the Na+/K+-pump, has previously been shown to interfere with intercellular communication. We have recently demonstrated a mechanism of this action of ouabain (1). We have showed that gap junctions between vascular smooth muscle cells (SMCs) are regulated through...... an interaction between the Na+/K+-pump and the Na+/Ca2+-exchanger leading to an increase in the intracellular calcium concentration in discrete areas near the plasma membrane. This regulation suggests a close association of the proteins in microdomains. We have also suggested that this Na...

  19. Accumulation of long-chain glycosphingolipids during aging is prevented by caloric restriction.

    Directory of Open Access Journals (Sweden)

    María José Hernández-Corbacho

    Full Text Available Chronic kidney disease and end-stage renal disease are major causes of morbidity and mortality that are seen far more commonly in the aged population. Interestingly, kidney function declines during aging even in the absence of underlying renal disease. Declining renal function has been associated with age-related cellular damage and dysfunction with reports of increased levels of apoptosis, necrosis, and inflammation in the aged kidney. Bioactive sphingolipids have been shown to regulate these same cellular processes, and have also been suggested to play a role in aging and cellular senescence.We hypothesized that alterations in kidney sphingolipids play a role in the declining kidney function that occurs during aging. To begin to address this, the sphingolipid profile was measured in young (3 mo, middle aged (9 mo and old (17 mo C57BL/6 male mice. Interestingly, while modest changes in ceramides and sphingoid bases were evident in kidneys from older mice, the most dramatic elevations were seen in long-chain hexosylceramides (HexCer and lactosylceramides (LacCer, with C14- and C16-lactosylceramides elevated as much as 8 and 12-fold, respectively. Increases in long-chain LacCers during aging are not exclusive to the kidney, as they also occur in the liver and brain. Importantly, caloric restriction, previously shown to prevent the declining kidney function seen in aging, inhibits accumulation of long-chain HexCer/LacCers and prevents the age-associated elevation of enzymes involved in their synthesis. Additionally, long-chain LacCers are also significantly elevated in human fibroblasts isolated from elderly individuals.This study demonstrates accumulation of the glycosphingolipids HexCer and LacCer in several different organs in rodents and humans during aging. In addition, data demonstrate that HexCer and LacCer metabolism is regulated by caloric restriction. Taken together, data suggest that HexCer/LacCers are important mediators of cellular

  20. Membrane rafts: a potential gateway for bacterial entry into host cells.

    Science.gov (United States)

    Hartlova, Anetta; Cerveny, Lukas; Hubalek, Martin; Krocova, Zuzana; Stulik, Jiri

    2010-04-01

    Pathogenic bacteria have developed various mechanisms to evade host immune defense systems. Invasion of pathogenic bacteria requires interaction of the pathogen with host receptors, followed by activation of signal transduction pathways and rearrangement of the cytoskeleton to facilitate bacterial entry. Numerous bacteria exploit specialized plasma membrane microdomains, commonly called membrane rafts, which are rich in cholesterol, sphingolipids and a special set of signaling molecules which allow entry to host cells and establishment of a protected niche within the host. This review focuses on the current understanding of the raft hypothesis and the means by which pathogenic bacteria subvert membrane microdomains to promote infection.

  1. Modelling patterns of pollinator species richness and diversity using satellite image texture.

    Directory of Open Access Journals (Sweden)

    Sylvia Hofmann

    Full Text Available Assessing species richness and diversity on the basis of standardised field sampling effort represents a cost- and time-consuming method. Satellite remote sensing (RS can help overcome these limitations because it facilitates the collection of larger amounts of spatial data using cost-effective techniques. RS information is hence increasingly analysed to model biodiversity across space and time. Here, we focus on image texture measures as a proxy for spatial habitat heterogeneity, which has been recognized as an important determinant of species distributions and diversity. Using bee monitoring data of four years (2010-2013 from six 4 × 4 km field sites across Central Germany and a multimodel inference approach we test the ability of texture features derived from Landsat-TM imagery to model local pollinator biodiversity. Textures were shown to reflect patterns of bee diversity and species richness to some extent, with the first-order entropy texture and terrain roughness being the most relevant indicators. However, the texture measurements accounted for only 3-5% of up to 60% of the variability that was explained by our final models, although the results are largely consistent across different species groups (bumble bees, solitary bees. While our findings provide indications in support of the applicability of satellite imagery textures for modeling patterns of bee biodiversity, they are inconsistent with the high predictive power of texture metrics reported in previous studies for avian biodiversity. We assume that our texture data captured mainly heterogeneity resulting from landscape configuration, which might be functionally less important for wild bees than compositional diversity of plant communities. Our study also highlights the substantial variability among taxa in the applicability of texture metrics for modelling biodiversity.

  2. Modelling patterns of pollinator species richness and diversity using satellite image texture.

    Science.gov (United States)

    Hofmann, Sylvia; Everaars, Jeroen; Schweiger, Oliver; Frenzel, Mark; Bannehr, Lutz; Cord, Anna F

    2017-01-01

    Assessing species richness and diversity on the basis of standardised field sampling effort represents a cost- and time-consuming method. Satellite remote sensing (RS) can help overcome these limitations because it facilitates the collection of larger amounts of spatial data using cost-effective techniques. RS information is hence increasingly analysed to model biodiversity across space and time. Here, we focus on image texture measures as a proxy for spatial habitat heterogeneity, which has been recognized as an important determinant of species distributions and diversity. Using bee monitoring data of four years (2010-2013) from six 4 × 4 km field sites across Central Germany and a multimodel inference approach we test the ability of texture features derived from Landsat-TM imagery to model local pollinator biodiversity. Textures were shown to reflect patterns of bee diversity and species richness to some extent, with the first-order entropy texture and terrain roughness being the most relevant indicators. However, the texture measurements accounted for only 3-5% of up to 60% of the variability that was explained by our final models, although the results are largely consistent across different species groups (bumble bees, solitary bees). While our findings provide indications in support of the applicability of satellite imagery textures for modeling patterns of bee biodiversity, they are inconsistent with the high predictive power of texture metrics reported in previous studies for avian biodiversity. We assume that our texture data captured mainly heterogeneity resulting from landscape configuration, which might be functionally less important for wild bees than compositional diversity of plant communities. Our study also highlights the substantial variability among taxa in the applicability of texture metrics for modelling biodiversity.

  3. Microbial products activate monocytic cells through detergent-resistant membrane microdomains.

    Science.gov (United States)

    Epelman, Slava; Berenger, Byron; Stack, Danuta; Neely, Graham G; Ma, Ling Ling; Mody, Christopher H

    2008-12-01

    Patients with cystic fibrosis suffer recurrent pulmonary infections that are characterized by an overactive yet ineffective and destructive inflammatory response that is associated with respiratory infections by Pseudomonas aeruginosa, a pathogen that produces a number of phlogistic molecules. To better understand this process, we used exoenzyme S (ExoS), one of the key P. aeruginosa-secreted exoproducts, which is known to stimulate cells via the Toll-like receptor (TLR) pathway. We found that ExoS induced proinflammatory cytokine production via the NF-kappaB, Erk1/2, and Src kinase pathways. Because Src kinases are concentrated within cholesterol-containing, detergent-resistant membrane microdomains (DRM) (also called lipid rafts) and DRM act as signaling platforms and amplifiers on the surface of cells, we addressed the role of DRM in ExoS signaling. ExoS bound directly to a subset of DRM and induced the phosphorylation of multiple proteins within DRM, including Src kinases. Disruption of DRM by cholesterol extraction prevented NF-kappaB and Erk 1/2 activation and TNF-alpha production in response to ExoS. Activation of monocytic cells by other TLR and Nod-like receptor agonists, such as lipoteichoic acid, lipopolysaccharide, and peptidoglycan, were also dependent on DRM, and disruption prevented TNF-alpha production. Disruption of DRM did not prevent ExoS binding but did release the Src kinase, Lyn, from the DRM fraction into the detergent-soluble fraction, a site in which Src kinases are not active. These studies show that ExoS, a TLR agonist, requires direct binding to DRM for optimal signaling, which suggests that DRM are possible therapeutic targets in cystic fibrosis.

  4. Ethanol Enhances TGF-β Activity by Recruiting TGF-β Receptors From Intracellular Vesicles/Lipid Rafts/Caveolae to Non-Lipid Raft Microdomains.

    Science.gov (United States)

    Huang, Shuan Shian; Chen, Chun-Lin; Huang, Franklin W; Johnson, Frank E; Huang, Jung San

    2016-04-01

    Regular consumption of moderate amounts of ethanol has important health benefits on atherosclerotic cardiovascular disease (ASCVD). Overindulgence can cause many diseases, particularly alcoholic liver disease (ALD). The mechanisms by which ethanol causes both beneficial and harmful effects on human health are poorly understood. Here we demonstrate that ethanol enhances TGF-β-stimulated luciferase activity with a maximum of 0.5-1% (v/v) in Mv1Lu cells stably expressing a luciferase reporter gene containing Smad2-dependent elements. In Mv1Lu cells, 0.5% ethanol increases the level of P-Smad2, a canonical TGF-β signaling sensor, by ∼ 2-3-fold. Ethanol (0.5%) increases cell-surface expression of the type II TGF-β receptor (TβR-II) by ∼ 2-3-fold from its intracellular pool, as determined by I(125) -TGF-β-cross-linking/Western blot analysis. Sucrose density gradient ultracentrifugation and indirect immunofluorescence staining analyses reveal that ethanol (0.5% and 1%) also displaces cell-surface TβR-I and TβR-II from lipid rafts/caveolae and facilitates translocation of these receptors to non-lipid raft microdomains where canonical signaling occurs. These results suggest that ethanol enhances canonical TGF-β signaling by increasing non-lipid raft microdomain localization of the TGF-β receptors. Since TGF-β plays a protective role in ASCVD but can also cause ALD, the TGF-β enhancer activity of ethanol at low and high doses appears to be responsible for both beneficial and harmful effects. Ethanol also disrupts the location of lipid raft/caveolae of other membrane proteins (e.g., neurotransmitter, growth factor/cytokine, and G protein-coupled receptors) which utilize lipid rafts/caveolae as signaling platforms. Displacement of these membrane proteins induced by ethanol may result in a variety of pathologies in nerve, heart and other tissues. © 2015 Wiley Periodicals, Inc.

  5. Generation of stable lipid raft microdomains in the enterocyte brush border by selective endocytic removal of non-raft membrane

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H

    2013-01-01

    The small intestinal brush border has an unusually high proportion of glycolipids which promote the formation of lipid raft microdomains, stabilized by various cross-linking lectins. This unique membrane organization acts to provide physical and chemical stability to the membrane that faces...... functions to enrich the contents of lipid raft components in the brush border. The lipophilic fluorescent marker FM, taken up into early endosomes in the terminal web region (TWEEs), was absent from detergent resistant membranes (DRMs), implying an association with non-raft membrane. Furthermore, neither...... major lipid raft-associated brush border enzymes nor glycolipids were detected by immunofluorescence microscopy in subapical punctae resembling TWEEs. Finally, two model raft lipids, BODIPY-lactosylceramide and BODIPY-GM1, were not endocytosed except when cholera toxin subunit B (CTB) was present...

  6. Deprojection of rich cluster images

    NARCIS (Netherlands)

    Zaroubi, S; Squires, G; Hoffman, Y; Silk, J

    1998-01-01

    We consider a general method of deprojecting two-dimensional images to reconstruct the three-dimensional structure of the projected object, assuming axial symmetry. The method consists of the application of the Fourier slice theorem to the general case in which the axis of symmetry is not

  7. Mushroom acidic glycosphingolipid induction of cytokine secretion from murine T cells and proliferation of NK1.1 α/β TCR-double positive cells in vitro

    International Nuclear Information System (INIS)

    Nozaki, Hirofumi; Itonori, Saki; Sugita, Mutsumi; Nakamura, Kimihide; Ohba, Kiyoshi; Suzuki, Akemi; Kushi, Yasunori

    2008-01-01

    Interferon (IFN)-γ and interleukin (IL)-4 regulate many types of immune responses. Here we report that acidic glycosphingolipids (AGLs) of Hypsizigus marmoreus and Pleurotus eryngii induced secretion of IFN- γ and IL-4 from T cells in a CD11c-positive cell-dependent manner similar to that of α-galactosylceramide (α-GalCer) and isoglobotriaosylceramide (iGb3), although activated T cells by AGLs showed less secretion of cytokine than those activated by α-GalCer. In addition, stimulation of these mushroom AGLs induced proliferation of NK1.1 α/β TCR-double positive cells in splenocytes. Administration of a mixture of α-GalCer and AGLs affected the stimulation of α-GalCer and generally induced a subtle Th1 bias for splenocytes but induced an extreme Th2 bias for thymocytes. These results suggested that edible mushroom AGLs contribute to immunomodulation

  8. Fully integrated high-speed intravascular optical coherence tomography/near-infrared fluorescence structural/molecular imaging in vivo using a clinically available near-infrared fluorescence-emitting indocyanine green to detect inflamed lipid-rich atheromata in coronary-sized vessels.

    Science.gov (United States)

    Lee, Sunki; Lee, Min Woo; Cho, Han Saem; Song, Joon Woo; Nam, Hyeong Soo; Oh, Dong Joo; Park, Kyeongsoon; Oh, Wang-Yuhl; Yoo, Hongki; Kim, Jin Won

    2014-08-01

    Lipid-rich inflamed coronary plaques are prone to rupture. The purpose of this study was to assess lipid-rich inflamed plaques in vivo using fully integrated high-speed optical coherence tomography (OCT)/near-infrared fluorescence (NIRF) molecular imaging with a Food and Drug Administration-approved indocyanine green (ICG). An integrated high-speed intravascular OCT/NIRF imaging catheter and a dual-modal OCT/NIRF system were constructed based on a clinical OCT platform. For imaging lipid-rich inflamed plaques, the Food and Drug Administration-approved NIRF-emitting ICG (2.25 mg/kg) or saline was injected intravenously into rabbit models with experimental atheromata induced by balloon injury and 12- to 14-week high-cholesterol diets. Twenty minutes after injection, in vivo OCT/NIRF imaging of the infrarenal aorta and iliac arteries was acquired only under contrast flushing through catheter (pullback speed up to ≤20 mm/s). NIRF signals were strongly detected in the OCT-visualized atheromata of the ICG-injected rabbits. The in vivo NIRF target-to-background ratio was significantly larger in the ICG-injected rabbits than in the saline-injected controls (Pfluorescence reflectance imaging, which correlated well with the in vivo target-to-background ratios (Pfluorescence microscopy, and histopathology also corroborated the in vivo imaging findings. Integrated OCT/NIRF structural/molecular imaging with a Food and Drug Administration -approved ICG accurately identified lipid-rich inflamed atheromata in coronary-sized vessels. This highly translatable dual-modal imaging approach could enhance our capabilities to detect high-risk coronary plaques. © 2014 American Heart Association, Inc.

  9. Aspherical Dust Envelopes Around Oxygen-Rich AGB Stars

    Directory of Open Access Journals (Sweden)

    Kyung-Won Suh

    2006-12-01

    Full Text Available We model the aspherical dust envelopes around O-rich AGB stars. We perform the radiative transfer model calculations for axisymmetric dust distributions. We simulate what could be observed from the aspherical dust envelopes around O-rich AGB stars by presenting the model spectral energy distributions and images at various wavelengths for different optical depths and viewing angles. The model results are very different from the ones with spherically symmetric geometry.

  10. The CLEO RICH detector

    International Nuclear Information System (INIS)

    Artuso, M.; Ayad, R.; Bukin, K.; Efimov, A.; Boulahouache, C.; Dambasuren, E.; Kopp, S.; Li, Ji; Majumder, G.; Menaa, N.; Mountain, R.; Schuh, S.; Skwarnicki, T.; Stone, S.; Viehhauser, G.; Wang, J.C.; Coan, T.E.; Fadeyev, V.; Maravin, Y.; Volobouev, I.; Ye, J.; Anderson, S.; Kubota, Y.; Smith, A.

    2005-01-01

    We describe the design, construction and performance of a Ring Imaging Cherenkov Detector (RICH) constructed to identify charged particles in the CLEO experiment. Cherenkov radiation occurs in LiF crystals, both planar and ones with a novel 'sawtooth'-shaped exit surface. Photons in the wavelength interval 135-165nm are detected using multi-wire chambers filled with a mixture of methane gas and triethylamine vapor. Excellent π/K separation is demonstrated

  11. Correlation between the habitats productivity and species richness (amphibians and reptiles) in Portugal through remote sensed data

    Science.gov (United States)

    Teodoro, A. C.; Sillero, N.; Alves, S.; Duarte, L.

    2013-10-01

    Several biogeographic theories propose that the species richness depends on the structure and ecosystems diversity. The habitat productivity, a surrogate for these variables, can be evaluated through satellite imagery, namely using vegetation indexes (e.g. NDVI). We analyzed the correlation between species richness (from the Portuguese Atlas of Amphibians and Reptiles) and NDVI (from Landsat, MODIS, and Vegetation images). The species richness database contains more than 80000 records, collected from bibliographic sources (at 1 or 10 km of spatial resolution) and fieldwork sampling stations (recorded with GPS devices). Several study areas were chosen for Landsat images (three subsets), and all Portugal for MODIS and Vegetation images. The Landsat subareas had different climatic and habitat characteristics, located in the north, center and south of Portugal. Different species richness datasets were used depending on the image spatial resolution: data with metric resolution were used for Landsat, and with 1 km resolution, for MODIS and Vegetation images. The NDVI indexes and all the images were calculated/processed in an open source software (Quantum GIS). Several plug-ins were applied in order to automatize several procedures. We did not find any correlation between the species richness of amphibians and reptiles (not even after separating both groups by species of Atlantic and Mediterranean affinity) and the NDVI calculated with Landsat, MODIS and Vegetation images. Our results may fail to find a relationship because as the species richness is not correlated with only one variable (NDVI), and thus other environmental variables must be considered.

  12. Velocity determination of neutron-rich projectile fragments with a ring-imaging Cherenkov detector

    International Nuclear Information System (INIS)

    Zeitelhack, K.

    1992-11-01

    For the velocity determination of relativistic heavy ions (A>100) in the energy range 300A.MeV ≤ E kin ≤ 2A.GeV a highly resolving, compact ring-imaging Cherenkov counter with large dynamical measurement range was developed. The Cherenkov light cone emitted in the flight of a relativistic heavy ion by a liquid layer (C 6 F 14 ) is focused on the entrance window of a one-dimensional position-resolving VUV-sensitive photon detector. This gas detector is operated at atmospheric pressure with a mixture of 90% methane and 10% isobutane with 0.04% TMAE as photosensitive admixture. For 725A.MeV 129 Xe ions a velocity resolution Δβ/β=1.8.10 -3 and a nuclear charge-number resolution ΔZ/Z=5.1.10 -2 was reached. The over the photon energy range 5.4 eV ≤ E γ ≤ 7.2 eV averaged detection efficiency of the detector system was determined to ε tot =2.8%>. At the 0deg magnet spectrometer Fragmentseparator of the GSI Darmstadt the RICH detector was for the first time applied for the identification of nuclear charge number and mass of heavy relativistic projectile fragments. In the experiment the production cross sections of very neutron-rich nuclei by fragmentation of 136 Xe projectiles in the reaction 76A.MeV 136 Xe on 27 Al were determined. From the measured production erates for the production of the double-magic nucleus 132 Zn in this reaction a cross section of σ=(0.4± 0.3 0.6 ) μbarn can be extrapolated. (orig./HSI) [de

  13. Ca2+ Channel Re-localization to Plasma-Membrane Microdomains Strengthens Activation of Ca2+-Dependent Nuclear Gene Expression

    Directory of Open Access Journals (Sweden)

    Krishna Samanta

    2015-07-01

    Full Text Available In polarized cells or cells with complex geometry, clustering of plasma-membrane (PM ion channels is an effective mechanism for eliciting spatially restricted signals. However, channel clustering is also seen in cells with relatively simple topology, suggesting it fulfills a more fundamental role in cell biology than simply orchestrating compartmentalized responses. Here, we have compared the ability of store-operated Ca2+ release-activated Ca2+ (CRAC channels confined to PM microdomains with a similar number of dispersed CRAC channels to activate transcription factors, which subsequently increase nuclear gene expression. For similar levels of channel activity, we find that channel confinement is considerably more effective in stimulating gene expression. Our results identify a long-range signaling advantage to the tight evolutionary conservation of channel clustering and reveal that CRAC channel aggregation increases the strength, fidelity, and reliability of the general process of excitation-transcription coupling.

  14. Membrane remodeling, an early event in benzo[α]pyrene-induced apoptosis

    International Nuclear Information System (INIS)

    Tekpli, Xavier; Rissel, Mary; Huc, Laurence; Catheline, Daniel; Sergent, Odile; Rioux, Vincent; Legrand, Philippe; Holme, Jorn A.; Dimanche-Boitrel, Marie-Therese; Lagadic-Gossmann, Dominique

    2010-01-01

    Benzo[α]pyrene (B[α]P) often serves as a model for mutagenic and carcinogenic polycyclic aromatic hydrocarbons (PAHs). Our previous work suggested a role of membrane fluidity in B[α]P-induced apoptotic process. In this study, we report that B[α]P modifies the composition of cholesterol-rich microdomains (lipid rafts) in rat liver F258 epithelial cells. The cellular distribution of the ganglioside-GM1 was markedly changed following B[α]P exposure. B[α]P also modified fatty acid composition and decreased the cholesterol content of cholesterol-rich microdomains. B[α]P-induced depletion of cholesterol in lipid rafts was linked to a reduced expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase). Aryl hydrocarbon receptor (AhR) and B[α]P-related H 2 O 2 formation were involved in the reduced expression of HMG-CoA reductase and in the remodeling of membrane microdomains. The B[α]P-induced membrane remodeling resulted in an intracellular alkalinization observed during the early phase of apoptosis. In conclusion, B[α]P altered the composition of plasma membrane microstructures through AhR and H 2 O 2 dependent-regulation of lipid biosynthesis. In F258 cells, the B[α]P-induced membrane remodeling was identified as an early apoptotic event leading to an intracellular alkalinization.

  15. Species richness alone does not predict cultural ecosystem service value

    Science.gov (United States)

    Graves, Rose A.; Pearson, Scott M.; Turner, Monica G.

    2017-01-01

    Many biodiversity-ecosystem services studies omit cultural ecosystem services (CES) or use species richness as a proxy and assume that more species confer greater CES value. We studied wildflower viewing, a key biodiversity-based CES in amenity-based landscapes, in Southern Appalachian Mountain forests and asked (i) How do aesthetic preferences for wildflower communities vary with components of biodiversity, including species richness?; (ii) How do aesthetic preferences for wildflower communities vary across psychographic groups?; and (iii) How well does species richness perform as an indicator of CES value compared with revealed social preferences for wildflower communities? Public forest visitors (n = 293) were surveyed during the summer of 2015 and asked to choose among images of wildflower communities in which flower species richness, flower abundance, species evenness, color diversity, and presence of charismatic species had been digitally manipulated. Aesthetic preferences among images were unrelated to species richness but increased with more abundant flowers, greater species evenness, and greater color diversity. Aesthetic preferences were consistent across psychographic groups and unaffected by knowledge of local flora or value placed on wildflower viewing. When actual wildflower communities (n = 54) were ranked based on empirically measured flower species richness or wildflower viewing utility based on multinomial logit models of revealed preferences, rankings were broadly similar. However, designation of hotspots (CES values above the median) based on species richness alone missed 27% of wildflower viewing utility hotspots. Thus, conservation priorities for sustaining CES should incorporate social preferences and consider multiple dimensions of biodiversity that underpin CES supply. PMID:28320953

  16. Electrochemical reactivity at graphitic micro-domains on polycrystalline boron doped diamond thin-films electrodes

    International Nuclear Information System (INIS)

    Mahe, E.; Devilliers, D.; Comninellis, Ch.

    2005-01-01

    This paper deals with the electrochemical reactivity of boron doped diamond (BDD) electrodes. A comparative study has been carried out to show the influence of the presence of graphitic micro-domains upon the surface of these films. Those graphitic domains are sometimes present on as-grown boron doped diamond electrodes. The effect of doping a pure Csp 3 diamond electrode is established by highly oriented pyrolytic graphite (HOPG) abrasion onto the diamond surface. In order to establish the effect of doping on a pure Csp 3 diamond electrode, the amount of graphitic domains was increased by means of HOPG crystals grafted onto the BDD surface. Indeed that method allows the enrichment of the Csp 2 contribution of the electrode. The presence of graphitic domains can be correlatively associated with the presence of kinetically active redox sites. The electrochemical reactivity of boron doped diamond electrodes shows a distribution of kinetic constants on the whole surface of the electrode corresponding to different active sites. In this paper, we have studied by cyclic voltammetry and electrochemical impedance spectroscopy the kinetics parameters of the ferri/ferrocyanide redox couple in KCl electrolyte. A method is proposed to diagnose the presence of graphitic domains on diamond electrodes, and an electrochemical 'pulse cleaning' procedure is proposed to remove them

  17. An Image-based Micro-continuum Pore-scale Model for Gas Transport in Organic-rich Shale

    Science.gov (United States)

    Guo, B.; Tchelepi, H.

    2017-12-01

    Gas production from unconventional source rocks, such as ultra-tight shales, has increased significantly over the past decade. However, due to the extremely small pores ( 1-100 nm) and the strong material heterogeneity, gas flow in shale is still not well understood and poses challenges for predictive field-scale simulations. In recent years, digital rock analysis has been applied to understand shale gas transport at the pore-scale. An issue with rock images (e.g. FIB-SEM, nano-/micro-CT images) is the so-called "cutoff length", i.e., pores and heterogeneities below the resolution cannot be resolved, which leads to two length scales (resolved features and unresolved sub-resolution features) that are challenging for flow simulations. Here we develop a micro-continuum model, modified from the classic Darcy-Brinkman-Stokes framework, that can naturally couple the resolved pores and the unresolved nano-porous regions. In the resolved pores, gas flow is modeled with Stokes equation. In the unresolved regions where the pore sizes are below the image resolution, we develop an apparent permeability model considering non-Darcy flow at the nanoscale including slip flow, Knudsen diffusion, adsorption/desorption, surface diffusion, and real gas effect. The end result is a micro-continuum pore-scale model that can simulate gas transport in 3D reconstructed shale images. The model has been implemented in the open-source simulation platform OpenFOAM. In this paper, we present case studies to demonstrate the applicability of the model, where we use 3D segmented FIB-SEM and nano-CT shale images that include four material constituents: organic matter, clay, granular mineral, and pore. In addition to the pore structure and the distribution of the material constituents, we populate the model with experimental measurements (e.g. size distribution of the sub-resolution pores from nitrogen adsorption) and parameters from the literature and identify the relative importance of different

  18. Analysis of ASTER data for mapping bauxite rich pockets within high altitude lateritic bauxite, Jharkhand, India

    Science.gov (United States)

    Guha, Arindam; Singh, Vivek Kr.; Parveen, Reshma; Kumar, K. Vinod; Jeyaseelan, A. T.; Dhanamjaya Rao, E. N.

    2013-04-01

    Bauxite deposits of Jharkhand in India are resulted from the lateritization process and therefore are often associated with the laterites. In the present study, ASTER (Advanced Space borne Thermal Emission and Reflection Radiometer) image is processed to delineate bauxite rich pockets within the laterites. In this regard, spectral signatures of lateritic bauxite samples are analyzed in the laboratory with reference to the spectral features of gibbsite (main mineral constituent of bauxite) and goethite (main mineral constituent of laterite) in VNIR-SWIR (visible-near infrared and short wave infrared) electromagnetic domain. The analysis of spectral signatures of lateritic bauxite samples helps in understanding the differences in the spectral features of bauxites and laterites. Based on these differences; ASTER data based relative band depth and simple ratio images are derived for spatial mapping of the bauxites developed within the lateritic province. In order to integrate the complementary information of different index image, an index based principal component (IPC) image is derived to incorporate the correlative information of these indices to delineate bauxite rich pockets. The occurrences of bauxite rich pockets derived from density sliced IPC image are further delimited by the topographic controls as it has been observed that the major bauxite occurrences of the area are controlled by slope and altitude. In addition to above, IPC image is draped over the digital elevation model (DEM) to illustrate how bauxite rich pockets are distributed with reference to the topographic variability of the terrain. Bauxite rich pockets delineated in the IPC image are also validated based on the known mine occurrences and existing geological map of the bauxite. It is also conceptually validated based on the spectral similarity of the bauxite pixels delineated in the IPC image with the ASTER convolved laboratory spectra of bauxite samples.

  19. Can Airborne Laser Scanning (ALS and Forest Estimates Derived from Satellite Images Be Used to Predict Abundance and Species Richness of Birds and Beetles in Boreal Forest?

    Directory of Open Access Journals (Sweden)

    Eva Lindberg

    2015-04-01

    Full Text Available In managed landscapes, conservation planning requires effective methods to identify high-biodiversity areas. The objective of this study was to evaluate the potential of airborne laser scanning (ALS and forest estimates derived from satellite images extracted at two spatial scales for predicting the stand-scale abundance and species richness of birds and beetles in a managed boreal forest landscape. Multiple regression models based on forest data from a 50-m radius (i.e., corresponding to a homogenous forest stand had better explanatory power than those based on a 200-m radius (i.e., including also parts of adjacent stands. Bird abundance and species richness were best explained by the ALS variables “maximum vegetation height” and “vegetation cover between 0.5 and 3 m” (both positive. Flying beetle abundance and species richness, as well as epigaeic (i.e., ground-living beetle richness were best explained by a model including the ALS variable “maximum vegetation height” (positive and the satellite-derived variable “proportion of pine” (negative. Epigaeic beetle abundance was best explained by “maximum vegetation height” at 50 m (positive and “stem volume” at 200 m (positive. Our results show that forest estimates derived from satellite images and ALS data provide complementary information for explaining forest biodiversity patterns. We conclude that these types of remote sensing data may provide an efficient tool for conservation planning in managed boreal landscapes.

  20. LHCb Upgraded RICH 2 Engineering Design Review Report

    CERN Document Server

    Garsed, Philip John; Cardinale, Roberta; Petrolini, Alessandro; Benettoni, Massimo; Simi, Gabriele; Zago, M; Easo, Sajan; D'Ambrosio, Carmelo; Frei, Christoph; He, Jibo; Piedigrossi, Didier

    2016-01-01

    During the Long Shutdown 2 of the LHC, the LHCb experiment and, specifically, its two Ring Imaging Cherenkov (RICH) detectors will undergo a major upgrade. RICH 2 will be refurbished with new photon detectors and their associated electronics, with the capability of up to 40 MHz sustained acquisition rate. A new support and cooling system has been developed for the two photodetector arrays, retaining the vessel, gas and optical systems unchanged. This document describes their new mechanical arrangement, its engineering design, installation and alignment. A summary of the project schedule and Institute responsibilities is provided.

  1. Impaired rich club and increased local connectivity in children with traumatic brain injury: Local support for the rich?

    Science.gov (United States)

    Verhelst, Helena; Vander Linden, Catharine; De Pauw, Toon; Vingerhoets, Guy; Caeyenberghs, Karen

    2018-03-12

    Recent evidence has shown the presence of a "rich club" in the brain, which constitutes a core network of highly interconnected and spatially distributed brain regions, important for high-order cognitive processes. This study aimed to map the rich club organization in 17 young patients with moderate to severe TBI (15.71 ± 1.75 years) in the chronic stage of recovery and 17 age- and gender-matched controls. Probabilistic tractography was performed on diffusion weighted imaging data to construct the edges of the structural connectomes using number of streamlines as edge weight. In addition, the whole-brain network was divided into a rich club network, a local network and a feeder network connecting the latter two. Functional outcome was measured with a parent questionnaire for executive functioning. Our results revealed a significantly decreased rich club organization (p values < .05) and impaired executive functioning (p < .001) in young patients with TBI compared with controls. Specifically, we observed reduced density values in all three subnetworks (p values < .005) and a reduced mean strength in the rich club network (p = .013) together with an increased mean strength in the local network (p = .002) in patients with TBI. This study provides new insights into the nature of TBI-induced brain network alterations and supports the hypothesis that the local subnetwork tries to compensate for the biologically costly subnetwork of rich club nodes after TBI. © 2018 Wiley Periodicals, Inc.

  2. The glycosphingolipid P₁ is an ovarian cancer-associated carbohydrate antigen involved in migration.

    Science.gov (United States)

    Jacob, F; Anugraham, M; Pochechueva, T; Tse, B W C; Alam, S; Guertler, R; Bovin, N V; Fedier, A; Hacker, N F; Huflejt, M E; Packer, N; Heinzelmann-Schwarz, V A

    2014-10-14

    The level of plasma-derived naturally circulating anti-glycan antibodies (AGA) to P1 trisaccharide has previously been shown to significantly discriminate between ovarian cancer patients and healthy women. Here we aim to identify the Ig class that causes this discrimination, to identify on cancer cells the corresponding P1 antigen recognised by circulating anti-P1 antibodies and to shed light into the possible function of this glycosphingolipid. An independent Australian cohort was assessed for the presence of anti-P1 IgG and IgM class antibodies using suspension array. Monoclonal and human derived anti-glycan antibodies were verified using three independent glycan-based immunoassays and flow cytometry-based inhibition assay. The P1 antigen was detected by LC-MS/MS and flow cytometry. FACS-sorted cell lines were studied on the cellular migration by colorimetric assay and real-time measurement using xCELLigence system. Here we show in a second independent cohort (n=155) that the discrimination of cancer patients is mediated by the IgM class of anti-P1 antibodies (P=0.0002). The presence of corresponding antigen P1 and structurally related epitopes in fresh tissue specimens and cultured cancer cells is demonstrated. We further link the antibody and antigen (P1) by showing that human naturally circulating and affinity-purified anti-P1 IgM isolated from patients ascites can bind to naturally expressed P1 on the cell surface of ovarian cancer cells. Cell-sorted IGROV1 was used to obtain two study subpopulations (P1-high, 66.1%; and P1-low, 33.3%) and observed that cells expressing high P1-levels migrate significantly faster than those with low P1-levels. This is the first report showing that P1 antigen, known to be expressed on erythrocytes only, is also present on ovarian cancer cells. This suggests that P1 is a novel tumour-associated carbohydrate antigen recognised by the immune system in patients and may have a role in cell migration. The clinical value of our data

  3. The globoseries glycosphingolipid SSEA-4 is a marker of bone marrow-derived clonal multipotent stromal cells in vitro and in vivo.

    Science.gov (United States)

    Rosu-Myles, Michael; McCully, Jennifer; Fair, Joel; Mehic, Jelica; Menendez, Pablo; Rodriguez, Rene; Westwood, Carole

    2013-05-01

    The therapeutic potential of multipotent stromal cells (MSC) may be enhanced by the identification of markers that allow their discrimination and enumeration both in vivo and in vitro. Here, we investigated the ability of embryonic stem cell-associated glycosphingolipids to isolate human MSC from both whole-bone-marrow (BM) and stromal cell cultures. Only SSEA-4 was consistently expressed on cells within the CD45loCD105hi marrow fraction and could be used to isolate cells with the capacity to give rise to stromal cultures containing MSC. Human stromal cultures, generated in either the presence or absence of serum, contained heterogeneous cell populations discriminated by the quantity of SSEA-4 epitopes detected on their surface. A low level of surface SSEA-4 (SSEA-4lo) correlated with undetectable levels of the α2,3-sialyltransferase-II enzyme required to synthesize SSEA-4; a reduced proliferative potential; and the loss of fat-, bone-, and cartilage-forming cells during long-term culture. In vitro, single cells with the capacity to generate multipotent stromal cultures were detected exclusively in the SSEA-4hi fraction. Our data demonstrate that a high level of surface epitopes for SSEA-4 provides a definitive marker of MSC from human BM.

  4. Development of an alignment system for the CBM rich

    Energy Technology Data Exchange (ETDEWEB)

    Hoehne, Claudia; Mahmoud, Tariq; Bendarouach, Jordan [Justus Liebig University, Giessen (Germany); Collaboration: CBM-Collaboration

    2015-07-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures in A+A collisions from 4-35 AGeV. One of the key detector components required for the CBM physics program is the RICH detector, which is developed for efficient and clean electron identification and pion suppression. Main detector components are a CO{sub 2} gaseous radiator, MAPMT or MCP photo-detectors and spherical glass mirror tiles, used as focusing elements, with spectral reflectivity down to the UV range. An important aspect to guarantee a stable operation of the RICH detector is the alignment and continuous monitor of the mirrors. CLAM (Continuous Line Alignment Monitoring), an alignment procedure developed by the COMPASS experiment, is planned to be used also for the RICH mirror system. A smaller-scale version has been implemented in the CBM RICH prototype detector and tested at the Cern PS/T9 beamline in November 2014. Using a grid and target dots made of retro-reflective material, it is possible to align the mirrors and monitor their displacements over time by analyzing and applying mathematical calculations on photographic images of the grid and targets reflected on the mirrors. The concept, first data and results of image processing are presented and discussed.

  5. Electrochemical reactivity at graphitic micro-domains on polycrystalline boron doped diamond thin-films electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mahe, E. [LI2C CNRS/UMR 7612, Laboratoire d' Electrochimie, Universite Pierre-et-Marie Curie - case courrier 51, 4, Place Jussieu, 75252 Paris Cedex 05 (France); Devilliers, D. [LI2C CNRS/UMR 7612, Laboratoire d' Electrochimie, Universite Pierre-et-Marie Curie - case courrier 51, 4, Place Jussieu, 75252 Paris Cedex 05 (France); Comninellis, Ch. [Unite de Genie Electrochimique, Institut de sciences des procedes chimiques et biologiques, Ecole Polytechnique Federale de Lausanne, 1015, Lausanne (Switzerland)

    2005-04-01

    This paper deals with the electrochemical reactivity of boron doped diamond (BDD) electrodes. A comparative study has been carried out to show the influence of the presence of graphitic micro-domains upon the surface of these films. Those graphitic domains are sometimes present on as-grown boron doped diamond electrodes. The effect of doping a pure Csp{sup 3} diamond electrode is established by highly oriented pyrolytic graphite (HOPG) abrasion onto the diamond surface. In order to establish the effect of doping on a pure Csp{sup 3} diamond electrode, the amount of graphitic domains was increased by means of HOPG crystals grafted onto the BDD surface. Indeed that method allows the enrichment of the Csp{sup 2} contribution of the electrode. The presence of graphitic domains can be correlatively associated with the presence of kinetically active redox sites. The electrochemical reactivity of boron doped diamond electrodes shows a distribution of kinetic constants on the whole surface of the electrode corresponding to different active sites. In this paper, we have studied by cyclic voltammetry and electrochemical impedance spectroscopy the kinetics parameters of the ferri/ferrocyanide redox couple in KCl electrolyte. A method is proposed to diagnose the presence of graphitic domains on diamond electrodes, and an electrochemical 'pulse cleaning' procedure is proposed to remove them.

  6. Echolucency of computerized ultrasound images of carotid atherosclerotic plaques are associated with increased levels of triglyceride-rich lipoproteins as well as increased plaque lipid content

    DEFF Research Database (Denmark)

    Grønholdt, Marie-Louise M.; Nordestgaard, Børge; Wiebe, Britt M.

    1998-01-01

    carotid plaque echo-lucency and that echo-lucency predicts a high plaque lipid content. Methods and Results-The study included 137 patients with neurological symptoms and greater than or equal to 50% stenosis of the relevant carotid artery, High-resolution B-mode ultrasound images of carotid plaques were......Background-Echo-lucency of carotid atherosclerotic plaques on computerized ultrasound B-mode images has been associated with a high incidence of brain infarcts as evaluated on CT scans. We tested the hypotheses that triglyceride-rich lipoproteins in the fasting and postprandial state predict...

  7. Broadband pH-Sensing Organic Transistors with Polymeric Sensing Layers Featuring Liquid Crystal Microdomains Encapsulated by Di-Block Copolymer Chains.

    Science.gov (United States)

    Seo, Jooyeok; Song, Myeonghun; Jeong, Jaehoon; Nam, Sungho; Heo, Inseok; Park, Soo-Young; Kang, Inn-Kyu; Lee, Joon-Hyung; Kim, Hwajeong; Kim, Youngkyoo

    2016-09-14

    We report broadband pH-sensing organic field-effect transistors (OFETs) with the polymer-dispersed liquid crystal (PDLC) sensing layers. The PDLC layers are prepared by spin-coating using ethanol solutions containing 4-cyano-4'-pentyl-biphenyl (5CB) and a diblock copolymer (PAA-b-PCBOA) that consists of LC-philic block [poly(4-cyano-biphenyl-4-oxyundecyl acrylate) (PCBOA)] and acrylic acid block [poly(acrylic acid) (PAA)]. The spin-coated sensing layers feature of 5CB microdomains (pH with only small amounts (10-40 μL) of analyte solutions in both static and dynamic perfusion modes. The positive drain current change is measured for acidic solutions (pH pH > 7) result in the negative change of drain current. The drain current trend in the present PDLC-i-OFET devices is explained by the shrinking-expanding mechanism of the PAA chains in the diblock copolymer layers.

  8. Nanoscale Relationship Between CD4 and CD25 of T Cells Visualized with NSOM/QD-Based Dual-Color Imaging System

    Science.gov (United States)

    Fan, Jinping; Lu, Xiaoxu; Liu, Shengde; Zhong, Liyun

    2015-10-01

    In this study, by using of near-field scanning optical microscopy (NSOM)/immune-labeling quantum dot (QD)-based dual-color imaging system, we achieved the direct visualization of nanoscale profiles for distribution and organization of CD4 and CD25 molecules in T cells. A novel and interesting finding was that though CD25 clustering as nanodomains were observed on the surface of CD4+CD25high regulatory T cells, these CD25 nanodomains were not co-localized with CD4 nanodomains. This result presented that the formation of these CD25 nanodomains on the surface of CD4+CD25high T cells were not associated with the response of T cell receptor (TCR)/CD3-dependent signal transduction. In contrast, on the surface of CD4+CD25low T cells, CD25 molecules distributed randomly without forming nanodomains while CD4 clustering as nanodomains can be observed; on the surface of CD8+CD25+ T cells, CD25 clustering as nanodomains and co-localization with CD8 nanodomains were observed. Collectively, above these results exhibited that TCR/CD3-based microdomains were indeed required for TCR/CD3-mediated T cells activation and enhanced the immune activity of CD4+CD25low T cells or CD8+CD25+ T cells. In particular, it was found that the formation of CD25 nanodomains and their segregation from TCR/CD3 microdomains were the intrinsic capability of CD4+CD25high T cells, suggesting this specific imaging feature of CD25 should be greatly associated with the regulatory activity of CD4+CD25high T cells. Importantly, this novel NSOM/QD-based dual-color imaging system will provide a useful tool for the research of distribution-function relationship of cell-surface molecules.

  9. The plasma membrane as a capacitor for energy and metabolism

    Science.gov (United States)

    Ray, Supriyo; Kassan, Adam; Busija, Anna R.; Rangamani, Padmini

    2016-01-01

    When considering which components of the cell are the most critical to function and physiology, we naturally focus on the nucleus, the mitochondria that regulate energy and apoptotic signaling, or other organelles such as the endoplasmic reticulum, Golgi, ribosomes, etc. Few people will suggest that the membrane is the most critical element of a cell in terms of function and physiology. Those that consider the membrane critical will point to its obvious barrier function regulated by the lipid bilayer and numerous ion channels that regulate homeostatic gradients. What becomes evident upon closer inspection is that not all membranes are created equal and that there are lipid-rich microdomains that serve as platforms of signaling and a means of communication with the intracellular environment. In this review, we explore the evolution of membranes, focus on lipid-rich microdomains, and advance the novel concept that membranes serve as “capacitors for energy and metabolism.” Within this framework, the membrane then is the primary and critical regulator of stress and disease adaptation of the cell. PMID:26771520

  10. CERN-built prototype RICH detector back from the USA

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    In summer 1999, a ring-imaging Cherenkov detector (RICH) developed, constructed and tested at CERN was dismantled and sent to the Brookhaven National Laboratory (BNL) where it was used to extend the particle identification range of the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The RICH was a prototype of part of the ALICE-HMPID detector. Here we see members of the STAR-RICH team from ALICE-HMPID group with the detector, still in its shipping crates, back from BNL. L. to r.: A.Braem, E. Schyns, D. Fraissard, C. David, A. Di Mauro, J. van Beelen, G. Paic, Y. Lesenechal, F. Piuz, P. Martinengo, D. Di Bari, G. De Cataldo, Y. Andres, M. Davenport, V. Barozier, E. Nappi, T. D. Williams.

  11. The density of GM1-enriched lipid rafts correlates inversely with the efficiency of transfection mediated by cationic liposomes.

    Science.gov (United States)

    Kovács, Tamás; Kárász, Andrea; Szöllosi, János; Nagy, Peter

    2009-08-01

    Although cationic liposome-mediated transfection has become a standard procedure, the mechanistic details of the process are unknown. It has been suggested that endocytic uptake of lipoplexes is efficient, and transfectability is largely determined by later steps. In this article, we stained GM1-enriched membrane microdomains, a subclass of lipid rafts, with subunit B of cholera toxin and correlated transfection efficiency with their density by quantitatively evaluating microscopic images. We found a strong anticorrelation between the density of GM1-enriched membrane microdomains and the efficacy of transfection monitored by measuring the expression level of GFP in different cell lines transfected by lipofection using two different transfection agents. These findings imply that GM1-enriched membrane microdomains interfere with the process of lipofection. The blocked step must be endocytosis since the accumulation of fluorescently labeled plasmids was lower in cells with high content of GM1-enriched membrane microdomains. Such a correlation was not observed in cells transfected by electroporation. By comparing the efficiency of lipofection in several cell lines we found that those with a high density of GM1-enriched membrane microdomains were the most resistant to transfection. We conclude that the inhibition of lipofection by GM1-enriched membrane microdomains is a general rule, and that endocytosis of lipoplexes can be rate limiting in cells with high density of GM1-enriched membrane rafts. Copyright 2009 International Society for Advancement of Cytometry.

  12. Performance of the LHCb RICH detector at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Adinolfi, M.; Brook, N.H.; Coombes, M.; Hampson, T.; Rademacker, J.H.; Solomin, A.; Voong, D. [University of Bristol, H.H. Wills Physics Laboratory, Bristol (United Kingdom); Aglieri Rinella, G.; Albrecht, E.; D' Ambrosio, C.; Forty, R.; Frei, C.; Gys, T.; Kanaya, N.; Koblitz, S.; Mollen, A.; Morant, J.; Piedigrossi, D.; Storaci, B.; Ullaland, O.; Vervink, K.; Wyllie, K. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Bellunato, T.; Calvi, M.; Fanchini, E.; Giachero, A.; Gotti, C.; Kucharczyk, M.; Maino, M.; Matteuzzi, C.; Perego, D.L.; Pessina, G. [Sezione INFN di Milano Bicocca, Milano (Italy); Benson, S.; Eisenhardt, S.; Fitzpatrick, C.; Kim, Y.M.; Lambert, D.; Main, A.; Muheim, F.; Playfer, S.; Sparkes, A.; Young, R. [University of Edinburgh, School of Physics and Astronomy, Edinburgh (United Kingdom); Blake, T. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Imperial College London, London (United Kingdom); Blanks, C.; Cameron, B.; Carson, L.; Egede, U.; Owen, P.; Patel, M.; Plackett, R.; Savidge, T.; Sepp, I.; Soomro, F.; Websdale, D. [Imperial College London, London (United Kingdom); Brisbane, S.; Contu, A.; Gandini, P.; Gao, R.; Harnew, N.; Hill, D.; Hunt, P.; John, M.; Johnson, D.; Malde, S.; Muresan, R.; Powell, A.; Thomas, C.; Topp-Joergensen, S.; Torr, N.; Wilkinson, G.; Xing, F. [University of Oxford, Department of Physics, Oxford (United Kingdom); Cardinale, R.; Fontanelli, F.; Mini' , G.; Petrolini, A.; Sannino, M. [Sezione INFN di Genova, Genova (Italy); Easo, S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); STFC Rutherford Appleton Laboratory, Didcot (United Kingdom); Garra Tico, J.; Gibson, V.; Gregson, S.; Haines, S.C.; Jones, C.R.; Katvars, S.; Kerzel, U.; Mangiafave, N.; Rogers, G.J.; Sigurdsson, S.; Wotton, S.A. [University of Cambridge, Cavendish Laboratory, Cambridge (United Kingdom); Mountain, R. [Syracuse University, Syracuse, NY (United States); Morris, J.V.; Nardulli, J.; Papanestis, A.; Patrick, G.N.; Ricciardi, S. [STFC Rutherford Appleton Laboratory, Didcot (United Kingdom); Sail, P.; Soler, F.J.P.; Spradlin, P. [University of Glasgow, School of Physics and Astronomy, Glasgow (United Kingdom); Collaboration: The LHCb RICH Collaboration

    2013-05-15

    The LHCb experiment has been taking data at the Large Hadron Collider (LHC) at CERN since the end of 2009. One of its key detector components is the Ring-Imaging Cherenkov (RICH) system. This provides charged particle identification over a wide momentum range, from 2-100 GeV/c. The operation and control, software, and online monitoring of the RICH system are described. The particle identification performance is presented, as measured using data from the LHC. Excellent separation of hadronic particle types ({pi}, K, p) is achieved. (orig.)

  13. Echo-lucency of computerized ultrasound images of carotid atherosclerotic plaques are associated with increased levels of triglyceride-rich lipoproteins as well as increased plaque lipid content

    DEFF Research Database (Denmark)

    Grønholdt, Marie-Louise Moes; Nordestgaard, Børge G.; Weibe, Brit M.

    1998-01-01

    carotid plaque echo-lucency and that echo-lucency predicts a high plaque lipid content. Methods and Results-The study included 137 patients with neurological symptoms and greater than or equal to 50% stenosis of the relevant carotid artery, High-resolution B-mode ultrasound images of carotid plaques were......Background-Echo-lucency of carotid atherosclerotic plaques on computerized ultrasound B-mode images has been associated with a high incidence of brain infarcts as evaluated on CT scans. We tested the hypotheses that triglyceride-rich lipoproteins in the fasting and postprandial state predict...

  14. Abnormal rich club organization and functional brain dynamics in schizophrenia.

    Science.gov (United States)

    van den Heuvel, Martijn P; Sporns, Olaf; Collin, Guusje; Scheewe, Thomas; Mandl, René C W; Cahn, Wiepke; Goñi, Joaquín; Hulshoff Pol, Hilleke E; Kahn, René S

    2013-08-01

    The human brain forms a large-scale structural network of regions and interregional pathways. Recent studies have reported the existence of a selective set of highly central and interconnected hub regions that may play a crucial role in the brain's integrative processes, together forming a central backbone for global brain communication. Abnormal brain connectivity may have a key role in the pathophysiology of schizophrenia. To examine the structure of the rich club in schizophrenia and its role in global functional brain dynamics. Structural diffusion tensor imaging and resting-state functional magnetic resonance imaging were performed in patients with schizophrenia and matched healthy controls. Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, the Netherlands. Forty-eight patients and 45 healthy controls participated in the study. An independent replication data set of 41 patients and 51 healthy controls was included to replicate and validate significant findings. MAIN OUTCOME(S) AND MEASURES: Measures of rich club organization, connectivity density of rich club connections and connections linking peripheral regions to brain hubs, measures of global brain network efficiency, and measures of coupling between brain structure and functional dynamics. Rich club organization between high-degree hub nodes was significantly affected in patients, together with a reduced density of rich club connections predominantly comprising the white matter pathways that link the midline frontal, parietal, and insular hub regions. This reduction in rich club density was found to be associated with lower levels of global communication capacity, a relationship that was absent for other white matter pathways. In addition, patients had an increase in the strength of structural connectivity-functional connectivity coupling. Our findings provide novel biological evidence that schizophrenia is characterized by a selective

  15. IGF-1 receptor targeted nanoparticles for image-guided therapy of stroma-rich and drug resistant human cancer.

    Science.gov (United States)

    Zhou, Hongyu; Qian, Weiping; Uckun, Fatih M; Zhou, Zhiyang; Wang, Liya; Wang, Andrew; Mao, Hui; Yang, Lily

    2016-04-17

    Low drug delivery efficiency and drug resistance from highly heterogeneous cancer cells and tumor microenvironment represent major challenges in clinical oncology. Growth factor receptor, IGF-1R, is overexpressed in both human tumor cells and tumor associated stromal cells. The level of IGF-1R expression is further up-regulated in drug resistant tumor cells. We have developed IGF-1R targeted magnetic iron oxide nanoparticles (IONPs) carrying multiple anticancer drugs into human tumors. This IGF-1R targeted theranostic nanoparticle delivery system has an iron core for non-invasive MR imaging, amphiphilic polymer coating to ensure the biocompatibility as well as for drug loading and conjugation of recombinant human IGF-1 as targeting molecules. Chemotherapy drugs, Doxorubicin (Dox), was encapsulated into the polymer coating and/or conjugated to the IONP surface by coupling with the carboxyl groups. The ability of IGF1R targeted theranostic nanoparticles to penetrate tumor stromal barrier and enhance tumor cell killing has been demonstrated in human pancreatic cancer patient tissue derived xenograft (PDX) models. Repeated systemic administrations of those IGF-1R targeted theranostic IONP carrying Dox led to breaking the tumor stromal barrier and improved therapeutic effect. Near infrared (NIR) optical and MR imaging enabled noninvasive monitoring of nanoparticle-drug delivery and therapeutic responses. Our results demonstrated that IGF-1R targeted nanoparticles carrying multiple drugs are promising combination therapy approaches for image-guided therapy of stroma-rich and drug resistant human cancer, such as pancreatic cancer.

  16. IGF-1 receptor targeted nanoparticles for image-guided therapy of stroma-rich and drug resistant human cancer

    Science.gov (United States)

    Zhou, Hongyu; Qian, Weiping; Uckun, Fatih M.; Zhou, Zhiyang; Wang, Liya; Wang, Andrew; Mao, Hui; Yang, Lily

    2016-05-01

    Low drug delivery efficiency and drug resistance from highly heterogeneous cancer cells and tumor microenvironment represent major challenges in clinical oncology. Growth factor receptor, IGF-1R, is overexpressed in both human tumor cells and tumor associated stromal cells. The level of IGF-1R expression is further up-regulated in drug resistant tumor cells. We have developed IGF-1R targeted magnetic iron oxide nanoparticles (IONPs) carrying multiple anticancer drugs into human tumors. This IGF-1R targeted theranostic nanoparticle delivery system has an iron core for non-invasive MR imaging, amphiphilic polymer coating to ensure the biocompatibility as well as for drug loading and conjugation of recombinant human IGF-1 as targeting molecules. Chemotherapy drugs, Doxorubicin (Dox), was encapsulated into the polymer coating and/or conjugated to the IONP surface by coupling with the carboxyl groups. The ability of IGF1R targeted theranostic nanoparticles to penetrate tumor stromal barrier and enhance tumor cell killing has been demonstrated in human pancreatic cancer patient tissue derived xenograft (PDX) models. Repeated systemic administrations of those IGF-1R targeted theranostic IONP carrying Dox led to breaking the tumor stromal barrier and improved therapeutic effect. Near infrared (NIR) optical and MR imaging enabled noninvasive monitoring of nanoparticle-drug delivery and therapeutic responses. Our results demonstrated that IGF-1R targeted nanoparticles carrying multiple drugs are promising combination therapy approaches for image-guided therapy of stroma-rich and drug resistant human cancer, such as pancreatic cancer.

  17. Design and R&D of RICH detectors for EIC experiments

    Science.gov (United States)

    Del Dotto, A.; Wong, C.-P.; Allison, L.; Awadi, M.; Azmoun, B.; Barbosa, F.; Brooks, W.; Cao, T.; Chiu, M.; Cisbani, E.; Contalbrigo, M.; Datta, A.; Demarteau, M.; Durham, J. M.; Dzhygadlo, R.; Fields, D.; Furletova, Y.; Gleason, C.; Grosse-Perdekamp, M.; Harris, J.; He, X.; van Hecke, H.; Horn, T.; Huang, J.; Hyde, C.; Ilieva, Y.; Kalicy, G.; Kimball, M.; Kistenev, E.; Kulinich, Y.; Liu, M.; Majka, R.; McKisson, J.; Mendez, R.; Nadel-Turonski, P.; Park, K.; Peters, K.; Rao, T.; Pisani, R.; Qiang, Y.; Rescia, S.; Rossi, P.; Sarsour, M.; Schwarz, C.; Schwiening, J.; da Silva, C. L.; Smirnov, N.; Stein, H.; Stevens, J.; Sukhanov, A.; Syed, S.; Tate, A.; Toh, J.; Towell, C.; Towell, R.; Tsang, T.; Wagner, R.; Wang, J.; Woody, C.; Xi, W.; Xie, J.; Zhao, Z. W.; Zihlmann, B.; Zorn, C.

    2017-12-01

    An Electron-Ion Collider (EIC) has been proposed to further explore the strong force and QCD, focusing on the structure and the interaction of gluon-dominated matter. A generic detector R&D program (EIC PID consortium) for the particle identification in EIC experiments was formed to explore technologically advanced solutions in this scope. In this context two Ring Imaging Cherenkov (RICH) counters have been proposed: a modular RICH detector which consists of an aerogel radiator, a Fresnel lens, a mirrored box, and pixelated photon sensor; a dual-radiator RICH, consisting of an aerogel radiator and C2F6 gas in a mirror-focused configuration. We present the simulations of the two detectors and their estimated performance.

  18. The Design of New HIV-IN Tethered Bifunctional Inhibitors using Multiple Microdomain Targeted Docking.

    Science.gov (United States)

    Ciubotaru, Mihai; Musat, Mihaela Georgiana; Surleac, Marius; Ionita, Elena; Petrescu, Andrei Jose; Abele, Edgars; Abele, Ramona

    2018-04-05

    Currently used antiretroviral HIV therapy drugs exclusively target critical groups in the enzymes essential for the viral life cycle. Increased mutagenesis of their genes, changes these viral enzymes which once mutated can evade therapeutic targeting, effects which confer drug resistance. To circumvent this, our review addresses a strategy to design and derive HIV-Integrase (HIV-IN) inhibitors which simultaneously target two IN functional domains, rendering it inactive even if the enzyme accumulates many mutations. First we review the enzymatic role of IN to insert the copied viral DNA into a chromosome of the host T lymphocyte, highlighting its main functional and structural features to be subjected to inhibitory action. From a functional and structural perspective we present all classes of HIV-IN inhibitors with their most representative candidates. For each chosen compound we also explain its mechanism of IN inhibition. We use the recently resolved cryo EM IN tetramer intasome DNA complex [1] onto which we dock various reference IN inhibitory chemical scaffolds such as to target adjacent functional IN domains. Pairing compounds with complementary activity, which dock in the vicinity of a IN structural microdomain, we design bifunctional new drugs which may not only be more resilient to IN mutations but also may be more potent inhibitors than their original counterparts. In the end of our review we propose synthesis pathways to link such paired compounds with enhanced synergistic IN inhibitory effects. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Calibration of the mirror system in the HERA-B RICH

    International Nuclear Information System (INIS)

    Staric, Marko; Krizan, Peter

    2008-01-01

    The mirror system of the HERA-B ring imaging Cherenkov (RICH) counter consists of two spherical and two planar mirrors, composed of altogether 116 mirror segments. Analysis of displacements of the Cherenkov ring center relative to the charged particle track, for given spherical-planar segment pairs, leads to accurate information regarding the orientation of individual mirror segments. The method for mirror calibration is described and the effect of applying the required corrections on the Cherenkov angle resolution of the HERA-B RICH is discussed

  20. Uptake of the glycosphingolipid sulfatide in the gastrointestinal tract and pancreas in vivo and in isolated islets of Langerhans

    Directory of Open Access Journals (Sweden)

    Fredman Pam

    2006-10-01

    Full Text Available Abstract Background The glycosphingolipid sulfatide has previously been found in several mammalian tissues, but information on the uptake of exogenously administered sulfatide in different organs in vivo is limited. In pancreatic beta cells, sulfatide has been shown to be involved in insulin processing and secretion in vitro. In this study, we examined the uptake of exogenously administered sulfatide and its distribution to the pancreatic beta cells. This might encourage future studies of the function(s of sulfatide in beta cell physiology in vivo. Radioactive sulfatide was given orally to mice whereafter the uptake of sulfatide in the gastrointestinal tract and subsequent delivery to the pancreas was examined. Sulfatide uptake in pancreas was also studied in vivo by i.p. administration of radioactive sulfatide in mice, and in vitro in isolated rat islets. Isolated tissue/islets were analysed by scintillation counting, autoradiography and thin-layer chromatography-ELISA. Results Sulfatide was taken up in the gastrointestinal tract for degradation or further transport to other organs. A selective uptake of short chain and/or hydroxylated sulfatide fatty acid isoforms was observed in the small intestine. Exogenously administered sulfatide was found in pancreas after i.p, but not after oral administration. The in vitro studies in isolated rat islets support that sulfatide, independently of its fatty acid length, is endocytosed and metabolised by pancreatic islets. Conclusion Our study supports a selective uptake and/or preservation of sulfatide in the gastrointestinal tract after oral administration and with emphasises on pancreatic sulfatide uptake, i.p. administration results in sulfatide at relevant location.

  1. What sugar next? Dimerization of sphingolipid glycosyltransferases

    NARCIS (Netherlands)

    van Meer, G.

    2001-01-01

    One of the great riddles of glycobiology is the function of the glycosphingolipids. Their vital role is clear from the fact that the lack only of subsets of glycosphingolipids results in premature death (1). Hundreds of glycosphingolipids populate the surface of mammalian cells. These may serve a

  2. LHCb RICH Online-Monitor and Data-Quality

    CERN Multimedia

    Kerzel, U

    2009-01-01

    The LHCb experiment at the LHC (CERN) has been optimised for high precision measurements of the beauty quark sector. Its main objective is to precisely determine and over-constrain the parameters of the CKM mixing matrix, and to search for further sources of CP violation and new physics beyond the Standard Model in rare B-decays. Efficient particle identification at high purities over a wide momentum range from around 1 to ~100GeV/c is vital to many LHCb analyses. Central to the LHCb particle identification strategy are two Ring Imaging CHerenkov (RICH) detectors which use Silica Aerogel and C4F10 and CF4 gas radiators. A rigorous quality control scheme is being developed to insure that the data recorded by the RICH detector meets the stringent requirements of the physics analyses. The talk summarises the LHCb RICH online monitoring and data-quality strategy. Multiple dedicated algorithms are deployed to detect any potential issue already during data-taking ranging from integrity checks, mis-alignments to cha...

  3. Event reconstruction in the RICH detector of the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Adamczewski, J.; Becker, K.-H.; Belogurov, S.; Boldyreva, N.; Chernogorov, A.; Deveaux, C.; Dobyrn, V.; Dürr, M.; Eom, J.; Eschke, J.; Höhne, C.; Kampert, K.-H.; Kleipa, V.; Kochenda, L.; Kolb, B.; Kopfer, J.; Kravtsov, P.; Lebedev, S.; Lebedeva, E.; Leonova, E.

    2014-01-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility will investigate the QCD phase diagram at high net-baryon densities and moderate temperatures. One of the key signatures will be di-leptons emitted from the hot and dense phase in heavy-ion collisions. Measuring di-electrons, a high purity of identified electrons is required in order to suppress the background. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detectors (TRD). In order to access the foreseen rare probes, the detector and the data acquisition have to handle interaction rates up to 10 MHz. Therefore, the development of fast and efficient event reconstruction algorithms is an important and challenging task in CBM. In this contribution event reconstruction and electron identification algorithms in the RICH detector are presented. So far they have been developed on simulated data but could already be tested on real data from a RICH prototype testbeam experiment at the CERN-PS. Efficient and fast ring recognition algorithms in the CBM-RICH are based on the Hough Transform method. Due to optical distortions of the rings, an ellipse fitting algorithm was elaborated to improve the ring radius resolution. An efficient algorithm based on the Artificial Neural Network was implemented for electron identification in RICH. All algorithms were significantly optimized to achieve maximum speed and minimum memory consumption. - Highlights: • Ring Imaging Cherenkov detector will serve for electron identification in CBM. • We present efficient ring recognition algorithm based on the Hough Transform method. • Developed algorithms were significantly optimized to achieve maximum speed up. • Electron identification algorithm in RICH based on the Artificial Neural Network. • Developed algorithms were successfully tested on real data from the RICH prototype

  4. Event reconstruction in the RICH detector of the CBM experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Adamczewski, J. [GSI Darmstadt (Germany); Becker, K.-H. [University Wuppertal (Germany); Belogurov, S. [ITEP Moscow (Russian Federation); Boldyreva, N. [PNPI Gatchina (Russian Federation); Chernogorov, A. [ITEP Moscow (Russian Federation); Deveaux, C. [University Gießen (Germany); Dobyrn, V. [PNPI Gatchina (Russian Federation); Dürr, M. [University Gießen (Germany); Eom, J. [Pusan National University (Korea, Republic of); Eschke, J. [GSI Darmstadt (Germany); Höhne, C. [University Gießen (Germany); Kampert, K.-H. [University Wuppertal (Germany); Kleipa, V. [GSI Darmstadt (Germany); Kochenda, L. [PNPI Gatchina (Russian Federation); Kolb, B. [GSI Darmstadt (Germany); Kopfer, J. [University Wuppertal (Germany); Kravtsov, P. [PNPI Gatchina (Russian Federation); Lebedev, S., E-mail: s.lebedev@gsi.de [University Gießen (Germany); Lebedeva, E. [University Gießen (Germany); Leonova, E. [PNPI Gatchina (Russian Federation); and others

    2014-12-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility will investigate the QCD phase diagram at high net-baryon densities and moderate temperatures. One of the key signatures will be di-leptons emitted from the hot and dense phase in heavy-ion collisions. Measuring di-electrons, a high purity of identified electrons is required in order to suppress the background. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detectors (TRD). In order to access the foreseen rare probes, the detector and the data acquisition have to handle interaction rates up to 10 MHz. Therefore, the development of fast and efficient event reconstruction algorithms is an important and challenging task in CBM. In this contribution event reconstruction and electron identification algorithms in the RICH detector are presented. So far they have been developed on simulated data but could already be tested on real data from a RICH prototype testbeam experiment at the CERN-PS. Efficient and fast ring recognition algorithms in the CBM-RICH are based on the Hough Transform method. Due to optical distortions of the rings, an ellipse fitting algorithm was elaborated to improve the ring radius resolution. An efficient algorithm based on the Artificial Neural Network was implemented for electron identification in RICH. All algorithms were significantly optimized to achieve maximum speed and minimum memory consumption. - Highlights: • Ring Imaging Cherenkov detector will serve for electron identification in CBM. • We present efficient ring recognition algorithm based on the Hough Transform method. • Developed algorithms were significantly optimized to achieve maximum speed up. • Electron identification algorithm in RICH based on the Artificial Neural Network. • Developed algorithms were successfully tested on real data from the RICH prototype.

  5. DHA-fluorescent probe is sensitive to membrane order and reveals molecular adaptation of DHA in ordered lipid microdomains☆

    Science.gov (United States)

    Teague, Heather; Ross, Ron; Harris, Mitchel; Mitchell, Drake C.; Shaikh, Saame Raza

    2012-01-01

    Docosahexaenoic acid (DHA) disrupts the size and order of plasma membrane lipid microdomains in vitro and in vivo. However, it is unknown how the highly disordered structure of DHA mechanistically adapts to increase the order of tightly packed lipid microdomains. Therefore, we studied a novel DHA-Bodipy fluorescent probe to address this issue. We first determined if the DHA-Bodipy probe localized to the plasma membrane of primary B and immortal EL4 cells. Image analysis revealed that DHA-Bodipy localized into the plasma membrane of primary B cells more efficiently than EL4 cells. We then determined if the probe detected changes in plasma membrane order. Quantitative analysis of time-lapse movies established that DHA-Bodipy was sensitive to membrane molecular order. This allowed us to investigate how DHA-Bodipy physically adapted to ordered lipid microdomains. To accomplish this, we employed steady-state and time-resolved fluorescence anisotropy measurements in lipid vesicles of varying composition. Similar to cell culture studies, the probe was highly sensitive to membrane order in lipid vesicles. Moreover, these experiments revealed, relative to controls, that upon incorporation into highly ordered microdomains, DHA-Bodipy underwent an increase in its fluorescence lifetime and molecular order. In addition, the probe displayed a significant reduction in its rotational diffusion compared to controls. Altogether, DHA-Bodipy was highly sensitive to membrane order and revealed for the first time that DHA, despite its flexibility, could become ordered with less rotational motion inside ordered lipid microdomains. Mechanistically, this explains how DHA acyl chains can increase order upon formation of lipid microdomains in vivo. PMID:22841541

  6. SOLAR SOURCES OF 3He-RICH SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 24

    International Nuclear Information System (INIS)

    Nitta, Nariaki V.; Mason, Glenn M.; Wang, Linghua; Cohen, Christina M. S.; Wiedenbeck, Mark E.

    2015-01-01

    Using high-cadence EUV images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we investigate the solar sources of 26 3 He-rich solar energetic particle events at ≲1 MeV nucleon −1 that were well-observed by the Advanced Composition Explorer during solar cycle 24. Identification of the solar sources is based on the association of 3 He-rich events with type III radio bursts and electron events as observed by Wind. The source locations are further verified in EUV images from the Solar and Terrestrial Relations Observatory, which provides information on solar activities in the regions not visible from the Earth. Based on AIA observations, 3 He-rich events are not only associated with coronal jets as emphasized in solar cycle 23 studies, but also with more spatially extended eruptions. The properties of the 3 He-rich events do not appear to be strongly correlated with those of the source regions. As in the previous studies, the magnetic connection between the source region and the observer is not always reproduced adequately by the simple potential field source surface model combined with the Parker spiral. Instead, we find a broad longitudinal distribution of the source regions extending well beyond the west limb, with the longitude deviating significantly from that expected from the observed solar wind speed

  7. Super-resolution imaging of ciliary microdomains in isolated olfactory sensory neurons using a custom two-color stimulated emission depletion microscope

    Science.gov (United States)

    Meyer, Stephanie A.; Ozbay, Baris N.; Potcoava, Mariana; Salcedo, Ernesto; Restrepo, Diego; Gibson, Emily A.

    2016-06-01

    We performed stimulated emission depletion (STED) imaging of isolated olfactory sensory neurons (OSNs) using a custom-built microscope. The STED microscope uses a single pulsed laser to excite two separate fluorophores, Atto 590 and Atto 647N. A gated timing circuit combined with temporal interleaving of the different color excitation/STED laser pulses filters the two channel detection and greatly minimizes crosstalk. We quantified the instrument resolution to be ˜81 and ˜44 nm, for the Atto 590 and Atto 647N channels. The spatial separation between the two channels was measured to be under 10 nm, well below the resolution limit. The custom-STED microscope is incorporated onto a commercial research microscope allowing brightfield, differential interference contrast, and epifluorescence imaging on the same field of view. We performed immunolabeling of OSNs in mice to image localization of ciliary membrane proteins involved in olfactory transduction. We imaged Ca2+-permeable cyclic nucleotide gated (CNG) channel (Atto 594) and adenylyl cyclase type III (ACIII) (Atto 647N) in distinct cilia. STED imaging resolved well-separated subdiffraction limited clusters for each protein. We quantified the size of each cluster to have a mean value of 88±48 nm and 124±43 nm, for CNG and ACIII, respectively. STED imaging showed separated clusters that were not resolvable in confocal images.

  8. Imaging the Oxygen-Rich Disk Toward the Silicate Carbon Star EU Andromedae

    National Research Council Canada - National Science Library

    Ohnaka, K; Boboltz, D. A

    2007-01-01

    .... We present multi-epoch, high-angular resolution observations of 22 GHz H2O masers toward the silicate carbon star EU And to probe the spatio-kinematic distribution of oxygen-rich material. Methods...

  9. Growth and alteration of uranium-rich microlite

    International Nuclear Information System (INIS)

    Giere, R.; Swope, R. J.; Buck, E. C.; Guggenheim, R.; Mathys, D.; Reusser, E.

    2000-01-01

    Uranium-rich microlite, a pyrochlore-group mineral, occurs in 440 Ma old lithium pegmatites of the Mozambique Belt in East Africa. Microlite exhibits a pronounced growth zoning, with a U-free core surrounded by a U-rich rim (UO 2 up to 17 wt.%). The core exhibits conjugate sets of straight cracks (cleavage planes) which provided pathways for a late-stage U-enriched pegmatitic fluid which interacted with the U-free microlite to produce a distinct U enrichment along the cracks and led to the formation of the U-rich rim. Following the stage of U incorporation into microlite, a second generation of hydrothermal fluids deposited mica along the cleavage planes. Subsequent to these two hydrothermal stages, the host rock was uplifted and subjected to intense low-temperature alteration during which Na, Ca and F were leached from the microlite crystals. This alteration also led to a hydration of microlite, but there is no evidence of U loss. These low-temperature alteration effects were only observed in the U-rich rim which is characterized by a large number of irregular cracks which are most probably the result of metamictization, as indicated by electron diffraction images and powder X-ray patterns. The pyrochlore-group minerals provide excellent natural analogues for pyrochlore-based nuclear waste forms, because samples of variable age and with high actinide contents are available

  10. MHC Class II and CD9 in Human Eosinophils Localize to Detergent-Resistant Membrane Microdomains

    Science.gov (United States)

    Akuthota, Praveen; Melo, Rossana C. N.; Spencer, Lisa A.

    2012-01-01

    Eosinophils function in murine allergic airways inflammation as professional antigen-presenting cells (APCs). In murine professional APC cell types, optimal functioning of MHC Class II depends on its lateral association in plasma membranes and colocalization with the tetraspanin CD9 into detergent-resistant membrane microdomains (DRMs). With human eosinophils, we evaluated the localization of MHC Class II (HLA-DR) to DRMs and the functional significance of such localization. In granulocyte-macrophage colony-stimulating factor–stimulated human eosinophils, antibody cross-linked HLA-DR colocalized by immunofluorescence microscopy focally on plasma membranes with CD9 and the DRM marker ganglioside GM1. In addition, HLA-DR coimmunoprecipitates with CD9 after chemical cross-linking of CD9. HLA-DR and CD9 were localized by Western blotting in eosinophil DRM subcellular fractions. DRM disruption with the cholesterol-depleting agent methyl-β-cyclodextrin decreased eosinophil surface expression of HLA-DR and CD9. We show that CD9 is abundant on the surface of eosinophils, presenting the first electron microscopy data of the ultrastructural immunolocalization of CD9 in human eosinophils. Disruption of HLA-DR–containing DRMs decreased the ability of superantigen-loaded human eosinophils to stimulate CD4+ T-cell activation (CD69 expression), proliferation, and cytokine production. Our results, which demonstrate that eosinophil MHC Class II localizes to DRMs in association with CD9 in a functionally significant manner, represent a novel insight into the organization of the antigen presentation complex of human eosinophils. PMID:21885678

  11. MHC Class II and CD9 in human eosinophils localize to detergent-resistant membrane microdomains.

    Science.gov (United States)

    Akuthota, Praveen; Melo, Rossana C N; Spencer, Lisa A; Weller, Peter F

    2012-02-01

    Eosinophils function in murine allergic airways inflammation as professional antigen-presenting cells (APCs). In murine professional APC cell types, optimal functioning of MHC Class II depends on its lateral association in plasma membranes and colocalization with the tetraspanin CD9 into detergent-resistant membrane microdomains (DRMs). With human eosinophils, we evaluated the localization of MHC Class II (HLA-DR) to DRMs and the functional significance of such localization. In granulocyte-macrophage colony-stimulating factor-stimulated human eosinophils, antibody cross-linked HLA-DR colocalized by immunofluorescence microscopy focally on plasma membranes with CD9 and the DRM marker ganglioside GM1. In addition, HLA-DR coimmunoprecipitates with CD9 after chemical cross-linking of CD9. HLA-DR and CD9 were localized by Western blotting in eosinophil DRM subcellular fractions. DRM disruption with the cholesterol-depleting agent methyl-β-cyclodextrin decreased eosinophil surface expression of HLA-DR and CD9. We show that CD9 is abundant on the surface of eosinophils, presenting the first electron microscopy data of the ultrastructural immunolocalization of CD9 in human eosinophils. Disruption of HLA-DR-containing DRMs decreased the ability of superantigen-loaded human eosinophils to stimulate CD4(+) T-cell activation (CD69 expression), proliferation, and cytokine production. Our results, which demonstrate that eosinophil MHC Class II localizes to DRMs in association with CD9 in a functionally significant manner, represent a novel insight into the organization of the antigen presentation complex of human eosinophils.

  12. Characterization of lipid rafts in human platelets using nuclear magnetic resonance: A pilot study

    Directory of Open Access Journals (Sweden)

    Joshua F. Ceñido

    2017-07-01

    Full Text Available Lipid microdomains (‘lipid rafts’ are plasma membrane subregions, enriched in cholesterol and glycosphingolipids, which participate dynamically in cell signaling and molecular trafficking operations. One strategy for the study of the physicochemical properties of lipid rafts in model membrane systems has been the use of nuclear magnetic resonance (NMR, but until now this spectroscopic method has not been considered a clinically relevant tool. We performed a proof-of-concept study to test the feasibility of using NMR to study lipid rafts in human tissues. Platelets were selected as a cost-effective and minimally invasive model system in which lipid rafts have previously been studied using other approaches. Platelets were isolated from plasma of medication-free adult research participants (n=13 and lysed with homogenization and sonication. Lipid-enriched fractions were obtained using a discontinuous sucrose gradient. Association of lipid fractions with GM1 ganglioside was tested using HRP-conjugated cholera toxin B subunit dot blot assays. 1H high resolution magic-angle spinning nuclear magnetic resonance (HRMAS NMR spectra obtained with single-pulse Bloch decay experiments yielded spectral linewidths and intensities as a function of temperature. Rates of lipid lateral diffusion that reported on raft size were measured with a two-dimensional stimulated echo longitudinal encode-decode NMR experiment. We found that lipid fractions at 10–35% sucrose density associated with GM1 ganglioside, a marker for lipid rafts. NMR spectra of the membrane phospholipids featured a prominent ‘centerband’ peak associated with the hydrocarbon chain methylene resonance at 1.3 ppm; the linewidth (full width at half-maximum intensity of this ‘centerband’ peak, together with the ratio of intensities between the centerband and ‘spinning sideband’ peaks, agreed well with values reported previously for lipid rafts in model membranes. Decreasing

  13. Platform for Quantitative Evaluation of Spatial Intratumoral Heterogeneity in Multiplexed Fluorescence Images.

    Science.gov (United States)

    Spagnolo, Daniel M; Al-Kofahi, Yousef; Zhu, Peihong; Lezon, Timothy R; Gough, Albert; Stern, Andrew M; Lee, Adrian V; Ginty, Fiona; Sarachan, Brion; Taylor, D Lansing; Chennubhotla, S Chakra

    2017-11-01

    We introduce THRIVE (Tumor Heterogeneity Research Interactive Visualization Environment), an open-source tool developed to assist cancer researchers in interactive hypothesis testing. The focus of this tool is to quantify spatial intratumoral heterogeneity (ITH), and the interactions between different cell phenotypes and noncellular constituents. Specifically, we foresee applications in phenotyping cells within tumor microenvironments, recognizing tumor boundaries, identifying degrees of immune infiltration and epithelial/stromal separation, and identification of heterotypic signaling networks underlying microdomains. The THRIVE platform provides an integrated workflow for analyzing whole-slide immunofluorescence images and tissue microarrays, including algorithms for segmentation, quantification, and heterogeneity analysis. THRIVE promotes flexible deployment, a maintainable code base using open-source libraries, and an extensible framework for customizing algorithms with ease. THRIVE was designed with highly multiplexed immunofluorescence images in mind, and, by providing a platform to efficiently analyze high-dimensional immunofluorescence signals, we hope to advance these data toward mainstream adoption in cancer research. Cancer Res; 77(21); e71-74. ©2017 AACR . ©2017 American Association for Cancer Research.

  14. Fast photon detection for the COMPASS RICH detector

    CERN Document Server

    Abbon, P; Alekseev, M; Angerer, H; Apollonio, M; Birsa, R; Bordalo, P; Bradamante, Franco; Bressan, A; Busso, L; Chiosso, M; Ciliberti, P; Colantoni, M L; Costa, S; Dalla Torre, S; Dafni, T; Delagnes, E; Deschamps, H; Díaz, V; Dibiase, N; Duic, V; Eyrich, W; Faso, D; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Gerassimov, S; Giorgi, M; Gobbo, B; Hagemann, R; Von Harrach, D; Heinsius, F H; Joosten, R; Ketzer, B; Königsmann, K C; Kolosov, V N; Konorov, I; Kramer, Daniel; Kunne, Fabienne; Lehmann, A; Levorato, S; Maggiora, A; Magnon, A; Mann, A; Martin, A; Menon, G; Mutter, A; Nahle, O; Nerling, F; Neyret, D; Pagano, P; Panebianco, S; Panzieri, D; Paul, S; Pesaro, G; Polak, J; Rebourgeard, P; Robinet, F; Rocco, E; Schiavon, Paolo; Schroder, W; Silva, L; Slunecka, M; Sozzi, F; Steiger, L; Sulc, M; Svec, M; Tessarotto, F; Teufel, A; Wollny, H

    2007-01-01

    The COMPASS experiment at the SPS accelerator at CERN uses a large scale Ring Imaging CHerenkov detector (RICH) to identify pions, kaons and protons in a wide momentum range. For the data taking in 2006, the COMPASS RICH has been upgraded in the central photon detection area (25% of the surface) with a new technology to detect Cherenkov photons at very high count rates of several 10^6 per second and channel and a new dead-time free read-out system, which allows trigger rates up to 100 kHz. The Cherenkov photons are detected by an array of 576 visible and ultra-violet sensitive multi-anode photomultipliers with 16 channels each. The upgraded detector showed an excellent performance during the 2006 data taking.

  15. Examining the effects of platelet-rich plasma and platelet-rich fibrin on autologous full thickness skin graft survival in rats

    Directory of Open Access Journals (Sweden)

    Noorahmad Latifi

    2016-02-01

    Full Text Available Background: Graft survival has been considered the major problem in reconstructive surgery. Clinical studies have helped us to understand the role of PRP in increasing skin survival. Our goal in this study was to examine the treatment effects of platelet-rich plasma (PRP and platelet-rich fibrin (PRF on autologous full thickness skin graft survival in male rats. Methods: This experimental study was performed on 36 rats of Sprague-Dawley race with weighing approximately 250 to 300 gr on May 2015 in animal laboratory of Hazrat Fatima Hospital. After anesthesia, rats were divided into 3 groups. We injected platelet-rich plasma (PRP in the first group, platelet-rich fibrin (PRF in the second and saline in the third group after removing the skin. Microscopic analysis was performed with camera (Canon powershot SX200, Tokyo, Japan on days 7, 14, 21 and 28 after surgery. We used image analysis system (ImageJ, ver. 1.45 to examine necrosis and survival rate. Samples were studied with H&E staining on day 28 microscopically for histological analysis of vascular density and angiogenesis. Results: Our findings showed the area of necrosis in animals injected with PRP on days 7 and 14, was meaningfully less than control group (P= 0.0001. There was no meaningful difference between control and PRP groups (P> 0.05. The area of necrosis in animals injected with PRF did not have any significant difference with control group from beginning to 21st day (P< 0.0001. there was no meaningful difference in vascular density between control and PRP group, whereas in animals injected with PRF the vascular density was significantly less than control group (P= 0.002. Conclusion: According to our results in this study, we can conclude that using autologous PRP can enhance the process of healing soft tissue injury and be affective at increasing graft survival. This method is suggested to be conducted for patients highly at risk of graft loss and also for those who are in need of

  16. RICH Detector for Jefferson Labs CLAS12

    Science.gov (United States)

    Trotta, Richard; Torisky, Ben; Benmokhtar, Fatiha

    2015-10-01

    Jefferson Lab (Jlab) is performing a large-scale upgrade to its Continuous Electron Beam Accelerator Facility (CEBAF) up to 12GeV beams. The Large Acceptance Spectrometer (CLAS12) in Hall B is being upgraded and a new hybrid Ring Imaging Cherenkov (RICH) detector is being developed to provide better kaon - pion separation throughout the 3 to 8 GeV/c momentum range. This detector will be used for a variety of Semi-Inclusive Deep Inelastic Scattering experiments. Cherenkov light can be accurately detected by a large array of sophisticated Multi-Anode Photomultiplier Tubes (MA-PMT) and heavier particles, like kaons, will span the inner radii. We are presenting our work on the creation of the RICH's geometry within the CLAS12 java framework. This development is crucial for future calibration, reconstructions and analysis of the detector.

  17. COMPASS mirror wall of RICH 1

    CERN Multimedia

    Patrice Loïez

    2001-01-01

    The COMPASS experiment uses ring imaging Cherenkov (RICH) counters to identify particles produced in high-energy muon collisions, to better understand the spin structure of the nucleon. Charged particles moving faster than the speed of light in the medium through which they are travelling emit a cone of Cherenkov radiation in the direction of their motion. The light in this cone is reflected from these mirrors onto a photo detector so that the size of the cone can be measured, which gives the energy of the particle.

  18. Aerogel RICH for the Belle II forward PID

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, S., E-mail: shohei.nishida@kek.jp [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Adachi, I. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Hamada, N. [Toho University, Funabashi (Japan); Hara, K. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Iijima, T. [Nagoya University, Nagoya (Japan); Iwata, S.; Kakuno, H. [Tokyo Metropolitan University, Hachioji (Japan); Kawai, H. [Chiba University, Chiba (Japan); Korpar, S.; Krizan, P. [Jozef Stefan Institute, Ljubljana (Slovenia); Ogawa, S. [Toho University, Funabashi (Japan); Pestotnik, R.; Ŝantelj, L.; Seljak, A. [Jozef Stefan Institute, Ljubljana (Slovenia); Sumiyoshi, T. [Tokyo Metropolitan University, Hachioji (Japan); Tabata, M. [Japan Aerospace Exploration Agency (JAXA), Sagamihara (Japan); Tahirovic, E. [Jozef Stefan Institute, Ljubljana (Slovenia); Yoshida, K. [Tokyo Metropolitan University, Hachioji (Japan); Yusa, Y. [Niigata University, Niigata (Japan)

    2014-12-01

    The Belle II spectrometer, a follow up of the very successful Belle experiment, is under construction at the SuperKEKB electron–positron collider at KEK in Japan. For the PID system in the forward region of the spectrometer, a proximity focusing ring-imaging Cherenkov (RICH) counter with an aerogel radiator is being developed. The counter will provide a 4σ separation of pions and kaons up to momenta of 4 GeV/c. For the position sensitive photon sensor, a 144-channel Hybrid Avalanche Photo-Detector (HAPD) has been developed with Hamamatsu Photonics K.K. The readout electronics is based on the custom developed ASIC. The design of the components is currently being finalized and part of their mass production have already started. Herein, we report the final design of the counter and a prototype test conducted with test beams at DESY. - Highlights: • We are constructing a RICH counter with aerogel radiator for Belle II. • Beam test for the prototype Aerogel RICH shows its good performance. • The effect of the neutron irradiation of the photodetector is examined.

  19. Performance of the CAPRICE98 balloon-borne gas-RICH detector

    CERN Document Server

    Bergström, D; Carlson, P J; Francke, T; Grinstein, S; Weber, N; Suffert, Martin; Hof, M; Kremer, J; Menn, W; Simon, M; Stephens, S A; Ambriola, M; Bellotti, R; Cafagna, F; Castellano, M G; Ciacio, F; Circella, M; De Marzo, C; Finetti, N; Papini, P; Piccardi, S; Spillantini, P; Bartalucci, S; Ricci, M; Bidoli, V; Casolino, M; De Pascale, M P; Morselli, A; Picozza, P; Sparvoli, R; Barbiellini, Guido; Schiavon, R P; Vacchi, A; Zampa, N; Mitchell, J W; Ormes, J F; Streitmatter, R E; Bravar, U; Stochaj, S J

    2001-01-01

    A RICH counter using a gas radiator of C/sub 4/F/sub 10/ and a photosensitive MWPC with pad readout has been developed, tested in particle beam at CERN and used in the CAPRICE98 balloon-borne experiment. The MWPC was operated with a TMAE and ethane mixture at atmospheric pressure and used a cathode pad plane to give an unambiguous image of the Cherenkov light. The induced signals in the pad plane were read our using the AMPLEX chip and CRAMS. The good efficiency of the Cherenkov light collection, the efficient detection of the weak signal from single UV photons together with a low noise level in the electronics of the RICH detector, resulted in a large number of detected photoelectrons per event. For beta approximately=1 charge one particles, an average of 12 photoelectrons per event were detected. The reconstructed Cherenkov angle of 50 mrad for a beta approximately=1 particle had a resolution of 1.2 mrad (rms). The RICH was flown with the CAPRICE98 magnetic spectrometer and was the first RICH counter ever u...

  20. The front-end (Level-0) electronics interface module for the LHCb RICH detectors

    Energy Technology Data Exchange (ETDEWEB)

    Adinolfi, M. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Bibby, J.H. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Brisbane, S. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Gibson, V. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Harnew, N. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Jones, M. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Libby, J. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom)]. E-mail: j.libby1@physics.ox.ac.uk; Powell, A. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Newby, C. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Rotolo, N. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Smale, N. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Somerville, L.; Sullivan, P.; Topp-Jorgensen, S. [Sub-department of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Wotton, S. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Wyllie, K. [CERN, CH-1211, Geneva 23 (Switzerland)

    2007-03-11

    The front-end (Level-0) electronics interface module for the LHCb Ring Imaging Cherenkov (RICH) detectors is described. This module integrates the novel hybrid photon detectors (HPDs), which instrument the RICH detectors, to the LHCb trigger, data acquisition (DAQ) and control systems. The system operates at 40 MHz with a first-level trigger rate of 1 MHz. The module design is presented and results are given for both laboratory and beam tests.

  1. The front-end (Level-0) electronics interface module for the LHCb RICH detectors

    International Nuclear Information System (INIS)

    Adinolfi, M.; Bibby, J.H.; Brisbane, S.; Gibson, V.; Harnew, N.; Jones, M.; Libby, J.; Powell, A.; Newby, C.; Rotolo, N.; Smale, N.; Somerville, L.; Sullivan, P.; Topp-Jorgensen, S.; Wotton, S.; Wyllie, K.

    2007-01-01

    The front-end (Level-0) electronics interface module for the LHCb Ring Imaging Cherenkov (RICH) detectors is described. This module integrates the novel hybrid photon detectors (HPDs), which instrument the RICH detectors, to the LHCb trigger, data acquisition (DAQ) and control systems. The system operates at 40 MHz with a first-level trigger rate of 1 MHz. The module design is presented and results are given for both laboratory and beam tests

  2. Characterization of the binding of Actinomyces naeslundii (ATCC 12104) and Actinomyces viscosus (ATCC 19246) to glycosphingolipids, using a solid-phase overlay approach

    International Nuclear Information System (INIS)

    Stroemberg, N.K.; Karlsson, K.A.

    1990-01-01

    Actinomyces naeslundii (ATCC 12104) and Actinomyces viscosus (ATCC 19246) were radiolabeled externally (125I) or metabolically (35S) and analyzed for their ability to bind glycosphingolipids separated on thin layer chromatograms or coated in microtiter wells. Two binding properties were found and characterized in detail. (i) Both bacteria showed binding to lactosylceramide (LacCer) in a fashion similar to bacteria characterized earlier. The activity of free LacCer was dependent on the ceramide structure; species with 2-hydroxy fatty acid and/or a trihydroxy base were positive, while species with nonhydroxy fatty acid and a dihydroxy base were negative binders. Several glycolipids with internal lactose were active but only gangliotriaosylceramide and gangliotetraosylceramide were as active as free LacCer. The binding to these three species was half-maximal at about 200 ng of glycolipid and was not blocked by preincubation of bacteria with free lactose or lactose-bovine serum albumin. (ii) A. naeslundii, unlike A. viscosus, showed a superimposed binding concluded to be to terminal or internal GalNAc beta and equivalent to a lactose-inhibitable specificity previously analyzed by other workers. Terminal Gal beta was not recognized in several glycolipids, although free Gal and lactose were active as soluble inhibitors. The binding was half-maximal at about 10 ng of glycolipid. A glycolipid mixture prepared from a scraping of human buccal epithelium contained an active glycolipid with sites for both binding specificities

  3. The effect of natural and synthetic fatty acids on membrane structure, microdomain organization, cellular functions and human health.

    Science.gov (United States)

    Ibarguren, Maitane; López, David J; Escribá, Pablo V

    2014-06-01

    This review deals with the effects of synthetic and natural fatty acids on the biophysical properties of membranes, and on their implication on cell function. Natural fatty acids are constituents of more complex lipids, like triacylglycerides or phospholipids, which are used by cells to store and obtain energy, as well as for structural purposes. Accordingly, natural and synthetic fatty acids may modify the structure of the lipid membrane, altering its microdomain organization and other physical properties, and provoking changes in cell signaling. Therefore, by modulating fatty acids it is possible to regulate the structure of the membrane, influencing the cell processes that are reliant on this structure and potentially reverting pathological cell dysfunctions that may provoke cancer, diabetes, hypertension, Alzheimer's and Parkinson's disease. The so-called Membrane Lipid Therapy offers a strategy to regulate the membrane composition through drug administration, potentially reverting pathological processes by re-adapting cell membrane structure. Certain fatty acids and their synthetic derivatives are described here that may potentially be used in such therapies, where the cell membrane itself can be considered as a target to combat disease. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Biophysical Techniques for Detection of cAMP and cGMP in Living Cells

    Directory of Open Access Journals (Sweden)

    Viacheslav O. Nikolaev

    2013-04-01

    Full Text Available Cyclic nucleotides cAMP and cGMP are ubiquitous second messengers which regulate myriads of functions in virtually all eukaryotic cells. Their intracellular effects are often mediated via discrete subcellular signaling microdomains. In this review, we will discuss state-of-the-art techniques to measure cAMP and cGMP in biological samples with a particular focus on live cell imaging approaches, which allow their detection with high temporal and spatial resolution in living cells and tissues. Finally, we will describe how these techniques can be applied to the analysis of second messenger dynamics in subcellular signaling microdomains.

  5. Quantitative membrane proteomics reveals a role for tetraspanin enriched microdomains during entry of human cytomegalovirus.

    Directory of Open Access Journals (Sweden)

    Kasinath Viswanathan

    Full Text Available Human cytomegalovirus (HCMV depends on and modulates multiple host cell membrane proteins during each stage of the viral life cycle. To gain a global view of the impact of HCMV-infection on membrane proteins, we analyzed HCMV-induced changes in the abundance of membrane proteins in fibroblasts using stable isotope labeling with amino acids (SILAC, membrane fractionation and protein identification by two-dimensional liquid chromatography and tandem mass spectrometry. This systematic approach revealed that CD81, CD44, CD98, caveolin-1 and catenin delta-1 were down-regulated during infection whereas GRP-78 was up-regulated. Since CD81 downregulation was also observed during infection with UV-inactivated virus we hypothesized that this tetraspanin is part of the viral entry process. Interestingly, additional members of the tetraspanin family, CD9 and CD151, were also downregulated during HCMV-entry. Since tetraspanin-enriched microdomains (TEM cluster host cell membrane proteins including known CMV receptors such as integrins, we studied whether TEMs are required for viral entry. When TEMs were disrupted with the cholesterol chelator methyl-β-cylcodextrin, viral entry was inhibited and this inhibition correlated with reduced surface levels of CD81, CD9 and CD151, whereas integrin levels remained unchanged. Furthermore, simultaneous siRNA-mediated knockdown of multiple tetraspanins inhibited viral entry whereas individual knockdown had little effect suggesting essential, but redundant roles for individual tetraspanins during entry. Taken together, our data suggest that TEM act as platforms for receptors utilized by HCMV for entry into cells.

  6. FRET imaging of hemoglobin concentration in Plasmodium falciparum-infected red cells.

    Directory of Open Access Journals (Sweden)

    Alessandro Esposito

    Full Text Available During its intraerythrocytic asexual reproduction cycle Plasmodium falciparum consumes up to 80% of the host cell hemoglobin, in large excess over its metabolic needs. A model of the homeostasis of falciparum-infected red blood cells suggested an explanation based on the need to reduce the colloid-osmotic pressure within the host cell to prevent its premature lysis. Critical for this hypothesis was that the hemoglobin concentration within the host cell be progressively reduced from the trophozoite stage onwards.The experiments reported here were designed to test this hypothesis by direct measurements of the hemoglobin concentration in live, infected red cells. We developed a novel, non-invasive method to quantify the hemoglobin concentration in single cells, based on Förster resonance energy transfer between hemoglobin molecules and the fluorophore calcein. Fluorescence lifetime imaging allowed the quantitative mapping of the hemoglobin concentration within the cells. The average fluorescence lifetimes of uninfected cohorts was 270+/-30 ps (mean+/-SD; N = 45. In the cytoplasm of infected cells the fluorescence lifetime of calcein ranged from 290+/-20 ps for cells with ring stage parasites to 590+/-13 ps and 1050+/-60 ps for cells with young trophozoites and late stage trophozoite/early schizonts, respectively. This was equivalent to reductions in hemoglobin concentration spanning the range from 7.3 to 2.3 mM, in line with the model predictions. An unexpected ancillary finding was the existence of a microdomain under the host cell membrane with reduced calcein quenching by hemoglobin in cells with mature trophozoite stage parasites.The results support the predictions of the colloid-osmotic hypothesis and provide a better understanding of the homeostasis of malaria-infected red cells. In addition, they revealed the existence of a distinct peripheral microdomain in the host cell with limited access to hemoglobin molecules indicating the

  7. Identification, Localization, and Functional Implications of the Microdomain-Forming Stomatin Family in the Ciliated Protozoan Paramecium tetraurelia

    Science.gov (United States)

    Stuermer, Claudia A. O.; Plattner, Helmut

    2013-01-01

    The SPFH protein superfamily is assumed to occur universally in eukaryotes, but information from protozoa is scarce. In the Paramecium genome, we found only Stomatins, 20 paralogs grouped in 8 families, STO1 to STO8. According to cDNA analysis, all are expressed, and molecular modeling shows the typical SPFH domain structure for all subgroups. For further analysis we used family-specific sequences for fluorescence and immunogold labeling, gene silencing, and functional tests. With all family members tested, we found a patchy localization at/near the cell surface and on vesicles. The Sto1p and Sto4p families are also associated with the contractile vacuole complex. Sto4p also makes puncta on some food vacuoles and is abundant on vesicles recycling from the release site of spent food vacuoles to the site of nascent food vacuole formation. Silencing of the STO1 family reduces mechanosensitivity (ciliary reversal upon touching an obstacle), thus suggesting relevance for positioning of mechanosensitive channels in the plasmalemma. Silencing of STO4 members increases pulsation frequency of the contractile vacuole complex and reduces phagocytotic activity of Paramecium cells. In summary, Sto1p and Sto4p members seem to be involved in positioning specific superficial and intracellular microdomain-based membrane components whose functions may depend on mechanosensation (extracellular stimuli and internal osmotic pressure). PMID:23376944

  8. Fabry disease: renal sphingolipid distribution in the alpha-Gal A knockout mouse model by mass spectrometric and immunohistochemical imaging

    Czech Academy of Sciences Publication Activity Database

    Kuchař, L.; Faltýsková, Helena; Ledvinová, J.; Krásný, Lukáš; Dobrovolný, R.; Hůlková, H.; Volný, Michael; Strohalm, Martin; Lemr, Karel; Kryšpínová, L.; Asfaw, B.; Rybová, J.; Desnick, R.J.; Havlíček, Vladimír

    2015-01-01

    Roč. 407, č. 8 (2015), s. 2283-2291 ISSN 1618-2642 R&D Projects: GA MŠk(CZ) LD13038; GA ČR(CZ) GAP206/12/1150 Institutional support: RVO:61388971 Keywords : Fabry disease * Kidney * Glycosphingolipids Subject RIV: CE - Biochemistry Impact factor: 3.125, year: 2015

  9. Measurements of the mirror surface homogeneity in the CBM-RICH

    Energy Technology Data Exchange (ETDEWEB)

    Lebedeva, Elena; Hoehne, Claudia [II. Physikalisches Institut, JLU Giessen (Germany); Collaboration: CBM-Collaboration

    2016-07-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR (Facility for Antiproton and Ion Research) complex will investigate the phase diagram of strongly interacting matter at high baryon densities and moderate temperatures in A+A collisions from 2-11 AGeV (SIS100) beam energy. One of the key detector components required for the CBM physics program is the RICH (Ring Imaging CHerenkov) detector, which is developed for efficient and clean electron identification and pion suppression. The CBM-RICH detector is being planned with gaseous radiator and in a standard projective geometry with focusing mirror elements and photon detector planes. One of the important criteria for the selection of appropriate mirrors is their optical surface quality (surface homogeneity). It defines the imaging quality of projected Cherenkov rings, and directly effects the ring finding and fitting performance. The global homogeneity has been tested with the D0 measurement. Local deformations e.g. by the mirror holding structure can be investigated with the Ronchi test and Shack-Hartmann method from which first results are discussed in this contribution.

  10. The experience of building and operating COMPASS RICH-1

    CERN Document Server

    Birsa, R; Rocco, E; Schiavon, P; Kramer, D; Schroder, W; Dafni, T; Tessarotto, F; Bressan, A; Schill, C; Deschamps, H; Mann, A; Sozzi, F; Colantoni, M; Dibiase, N; Abbon, P; Svec, M; Delagnes, E; Ketzer, B; Joosten, R; Steiger, L; Ciliberti, P; Konigsmann, K; Maggiora, A; Kolosov, V N; Giorgi, M; Sbrizzai, G; Nahle, O; Kunne, F; Sulc, M; Teufel, A; Paul, S; Neyret, D; Rebourgeard, P; Menon, G; Dalla Torre, S; Hagemann, R; Slunecka, M; Martin, A; Magnon, A; Takekawa, S; Finger, M; Bradamante, F; Heinsius, F H; Nerling, F; Gerassimov, S; Polak, J; Alexeev, M; Pizzolotto, C; Chiosso, M; Gobbo, B; Angerer, H; Denisov, O; Ferrero, A; Baum, G; Franco, C; Lehmann, A; Bordalo, P; Duic, V; Konorov, I; Mutter, A; Levorato, S; Robinet, F; von Harrach, D; Fischer, H; Schoenmeier, P; Pesaro, G; Wollny, H; Panzieri, D

    2011-01-01

    COMPASS RICH-1 is a large size gaseous Imaging Cherenkov Detector providing hadron identification in the range from 3 to 55 GeV/c, in the wide acceptance spectrometer of the COMPASS Experiment at CERN SPS. It uses a 3 m long C(4)F(10) radiator, a 21 m(2) large VUV mirror surface and two kinds of photon detectors: MAPMTs and MWPCs with CsI photocathodes, covering a total of 5.5 m(2). It is in operation since 2002 and its performance has increased in time thanks to progressive optimization and mostly to a major upgrade which was implemented in 2006. The main characteristics of COMPASS RICH-1 components are described and some specific aspects related to the radiator gas system, the mirror alignment, the MWPC electrical stability and the readout electronics are discussed. Some key features of the event reconstruction and the PID analysis are presented together with results from the COMPASS RICH-1 performance characterization study. (C) 2010 Elsevier B.V. All rights reserved.

  11. Image Quality in High-resolution and High-cadence Solar Imaging

    Science.gov (United States)

    Denker, C.; Dineva, E.; Balthasar, H.; Verma, M.; Kuckein, C.; Diercke, A.; González Manrique, S. J.

    2018-03-01

    Broad-band imaging and even imaging with a moderate bandpass (about 1 nm) provides a photon-rich environment, where frame selection (lucky imaging) becomes a helpful tool in image restoration, allowing us to perform a cost-benefit analysis on how to design observing sequences for imaging with high spatial resolution in combination with real-time correction provided by an adaptive optics (AO) system. This study presents high-cadence (160 Hz) G-band and blue continuum image sequences obtained with the High-resolution Fast Imager (HiFI) at the 1.5-meter GREGOR solar telescope, where the speckle-masking technique is used to restore images with nearly diffraction-limited resolution. The HiFI employs two synchronized large-format and high-cadence sCMOS detectors. The median filter gradient similarity (MFGS) image-quality metric is applied, among others, to AO-corrected image sequences of a pore and a small sunspot observed on 2017 June 4 and 5. A small region of interest, which was selected for fast-imaging performance, covered these contrast-rich features and their neighborhood, which were part of Active Region NOAA 12661. Modifications of the MFGS algorithm uncover the field- and structure-dependency of this image-quality metric. However, MFGS still remains a good choice for determining image quality without a priori knowledge, which is an important characteristic when classifying the huge number of high-resolution images contained in data archives. In addition, this investigation demonstrates that a fast cadence and millisecond exposure times are still insufficient to reach the coherence time of daytime seeing. Nonetheless, the analysis shows that data acquisition rates exceeding 50 Hz are required to capture a substantial fraction of the best seeing moments, significantly boosting the performance of post-facto image restoration.

  12. Ankyrin-B coordinates the Na/K ATPase, Na/Ca exchanger, and InsP3 receptor in a cardiac T-tubule/SR microdomain.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available We report identification of an ankyrin-B-based macromolecular complex of Na/K ATPase (alpha 1 and alpha 2 isoforms, Na/Ca exchanger 1, and InsP3 receptor that is localized in cardiomyocyte T-tubules in discrete microdomains distinct from classic dihydropyridine receptor/ryanodine receptor "dyads." E1425G mutation of ankyrin-B, which causes human cardiac arrhythmia, also blocks binding of ankyrin-B to all three components of the complex. The ankyrin-B complex is markedly reduced in adult ankyrin-B(+/- cardiomyocytes, which may explain elevated [Ca2+]i transients in these cells. Thus, loss of the ankyrin-B complex provides a molecular basis for cardiac arrhythmia in humans and mice. T-tubule-associated ankyrin-B, Na/Ca exchanger, and Na/K ATPase are not present in skeletal muscle, where ankyrin-B is expressed at 10-fold lower levels than in heart. Ankyrin-B also is not abundantly expressed in smooth muscle. We propose that the ankyrin-B-based complex is a specialized adaptation of cardiomyocytes with a role for cytosolic Ca2+ modulation.

  13. Diffusion-weighted magnetic resonance imaging for the detection of lipid-rich necrotic core in carotid atheroma in vivo

    International Nuclear Information System (INIS)

    Young, Victoria Eleanor; Patterson, Andrew J.; Sadat, Umar; Bowden, David J.; Tang, Tjun Y.; Gillard, Jonathan H.; Graves, Martin J.; Priest, Andrew N.; Skepper, Jeremy N.; Kirkpatrick, Peter J.

    2010-01-01

    Research has shown that knowing the morphology of carotid atheroma improves current risk stratification for predicting subsequent thrombo-embolic events. Previous magnetic resonance (MR) ex vivo studies have shown that diffusion-weighted imaging (DWI) can detect lipid-rich necrotic core (LR/NC) and fibrous cap. This study aims to establish if this is achievable in vivo. Twenty-six patients (mean age 73 years, range 54-87 years) with moderate to severe carotid stenosis confirmed on ultrasound were imaged. An echo-planar DWI sequence was performed along with standard high-resolution MR imaging. Apparent diffusion coefficient (ADC) maps were evaluated. Two independent readers reported the mean ADC values from regions of interest defining LR/NCs and fibrous caps. For subjects undergoing carotid endarterectomy (n = 19), carotid specimens were obtained and stained using Nile red. The mean ADC values were 1.0 x 10 -3 mm 2 /s (±SD 0.3 x 10 -3 mm 2 /s) and 0.7 x 10 -3 mm 2 /s (±SD 0.2 x 10 -3 mm 2 /s) for fibrous cap and LR/NC, respectively; the difference was significant (p < 0.0001). The intra-class correlation coefficients summarising the agreement between the two independent readers were 0.84 and 0.60 for fibrous cap and LR/NC, respectively. Comparison of quantitative ADC values and histology (by subjective grading of lipid content) showed a significant correlation: heavier lipid staining matched lower ADC values (r = -0.435, p = 0.005). This study indicates that DWI can be used to distinguish LR/NC and the fibrous cap. The study also suggests that the mean ADC value may be linearly related to subjective graded LR/NC content determined by histology. (orig.)

  14. Diffusion-weighted magnetic resonance imaging for the detection of lipid-rich necrotic core in carotid atheroma in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Young, Victoria Eleanor; Patterson, Andrew J.; Sadat, Umar; Bowden, David J.; Tang, Tjun Y.; Gillard, Jonathan H. [Addenbrooke' s Hospital, University Department of Radiology, Box 218, Cambridge (United Kingdom); Graves, Martin J.; Priest, Andrew N. [Addenbrooke' s Hospital, University Department of Radiology, Box 218, Cambridge (United Kingdom); Addenbrooke' s Hospital, Department of Medical Physics, Cambridge (United Kingdom); Skepper, Jeremy N. [University of Cambridge, Multi-imaging Centre, Cambridge (United Kingdom); Kirkpatrick, Peter J. [Addenbrooke' s Hospital, Department of Neurosurgery, Cambridge (United Kingdom)

    2010-10-15

    Research has shown that knowing the morphology of carotid atheroma improves current risk stratification for predicting subsequent thrombo-embolic events. Previous magnetic resonance (MR) ex vivo studies have shown that diffusion-weighted imaging (DWI) can detect lipid-rich necrotic core (LR/NC) and fibrous cap. This study aims to establish if this is achievable in vivo. Twenty-six patients (mean age 73 years, range 54-87 years) with moderate to severe carotid stenosis confirmed on ultrasound were imaged. An echo-planar DWI sequence was performed along with standard high-resolution MR imaging. Apparent diffusion coefficient (ADC) maps were evaluated. Two independent readers reported the mean ADC values from regions of interest defining LR/NCs and fibrous caps. For subjects undergoing carotid endarterectomy (n = 19), carotid specimens were obtained and stained using Nile red. The mean ADC values were 1.0 x 10{sup -3} mm{sup 2}/s ({+-}SD 0.3 x 10{sup -3} mm{sup 2}/s) and 0.7 x 10{sup -3} mm{sup 2}/s ({+-}SD 0.2 x 10{sup -3} mm{sup 2}/s) for fibrous cap and LR/NC, respectively; the difference was significant (p < 0.0001). The intra-class correlation coefficients summarising the agreement between the two independent readers were 0.84 and 0.60 for fibrous cap and LR/NC, respectively. Comparison of quantitative ADC values and histology (by subjective grading of lipid content) showed a significant correlation: heavier lipid staining matched lower ADC values (r = -0.435, p = 0.005). This study indicates that DWI can be used to distinguish LR/NC and the fibrous cap. The study also suggests that the mean ADC value may be linearly related to subjective graded LR/NC content determined by histology. (orig.)

  15. Clathrin- and caveolin-independent entry of human papillomavirus type 16--involvement of tetraspanin-enriched microdomains (TEMs).

    Science.gov (United States)

    Spoden, Gilles; Freitag, Kirsten; Husmann, Matthias; Boller, Klaus; Sapp, Martin; Lambert, Carsten; Florin, Luise

    2008-10-02

    Infectious entry of human papillomaviruses into their host cells is an important step in the viral life cycle. For cell binding these viruses use proteoglycans as initial attachment sites. Subsequent transfer to a secondary receptor molecule seems to be involved in virus uptake. Depending on the papillomavirus subtype, it has been reported that entry occurs by clathrin- or caveolin-mediated mechanisms. Regarding human papillomavirus type 16 (HPV16), the primary etiologic agent for development of cervical cancer, clathrin-mediated endocytosis was described as infectious entry pathway. Using immunofluorescence and infection studies we show in contrast to published data that infectious entry of HPV16 occurs in a clathrin- and caveolin-independent manner. Inhibition of clathrin- and caveolin/raft-dependent endocytic pathways by dominant-negative mutants and siRNA-mediated knockdown, as well as inhibition of dynamin function, did not impair infection. Rather, we provide evidence for involvement of tetraspanin-enriched microdomains (TEMs) in HPV16 endocytosis. Following cell attachment, HPV16 particles colocalized with the tetraspanins CD63 and CD151 on the cell surface. Notably, tetraspanin-specific antibodies and siRNA inhibited HPV16 cell entry and infection, confirming the importance of TEMs for infectious endocytosis of HPV16. Tetraspanins fulfill various roles in the life cycle of a number of important viral pathogens, including human immunodeficiency virus (HIV) and hepatitis C virus (HCV). However, their involvement in endocytosis of viral particles has not been proven. Our data indicate TEMs as a novel clathrin- and caveolin-independent invasion route for viral pathogens and especially HPV16.

  16. Interactions des antibiotiques ituriniques avec la membrane plasmique. Apport des systèmes biomimétiques des membranes (synthèse bibliographique

    Directory of Open Access Journals (Sweden)

    Nasir, MN.

    2013-01-01

    Full Text Available Interactions of iturinic antibiotics with plasma membrane. Contribution of biomimetic membranes. Iturinic antibiotics are produced by Bacillus subtilis strains and constitute a family including iturin A, mycosubtilin and bacillomycins D, F and Lc. These are cyclic lipopeptides with β-amino fatty acids linked up to a peptide constituted by seven α-aminoacids with an invariable LDDLLDL chiral sequence. The first three α-aminoacids containing the tyrosyl residue are the same for all members. They are well known for their strong antifungal activities but they also have antibacterial and hemolytic properties. These biological properties are due to their amphiphilic nature, allowing interactions with different membrane components. Sterols found in plasma membranes are the privileged interaction partners of these lipopeptides. Moreover, the tyrosyl residue of the iturinic antibiotics seems to play an important role during their fixation to the plasma membrane, the result of which is often cellular lysis. Within plasma membranes, there are particular regions with a high sterol content. These microdomains have a different composition compared to the rest of the membrane; they are rich in certain lipids and proteins and are involved in many key cellular processes. The perturbation of these microdomains could therefore have an important impact on the cell. Due to their composition, these microdomains may constitute the preferential target of iturin antibiotics. This review aims to summarize the studies relating to the biological activities of iturinic antibiotics. It focuses in particular on the existing knowledge regarding iturin antibiotics at the molecular level and discusses both the key chemical groups of these drugs and the potentiality of microdomains to constitute a target for these molecules.

  17. Mesoscopic and Macroscopic Optoacoustic Imaging of Cancer

    NARCIS (Netherlands)

    Taruttis, Adrian; van Dam, Gooitzen M.; Ntziachristos, Vasilis

    2015-01-01

    Optoacoustic imaging combines the rich contrast of optical methods with the resolution of ultrasound imaging. It can therefore deliver optical visualization of cancer far deeper in tissue than optical microscopy and other conventional optical imaging methods. Technological progress and novel

  18. Variation in 12 porcine genes involved in the carbohydrate moiety assembly of glycosphingolipids does not account for differential binding of F4 Escherichia coli and their fimbriae.

    Science.gov (United States)

    Goetstouwers, Tiphanie; Van Poucke, Mario; Coddens, Annelies; Nguyen, Van Ut; Melkebeek, Vesna; Deforce, Dieter; Cox, Eric; Peelman, Luc J

    2014-10-03

    Glycosphingolipids (GSLs) are important membrane components composed of a carbohydrate structure attached to a hydrophobic ceramide. They can serve as specific membrane receptors for microbes and microbial products, such as F4 Escherichia coli (F4 ETEC) and isolated F4 fimbriae. The aim of this study was to investigate the hypothesis that variation in genes involved in the assembly of the F4 binding carbohydrate moiety of GSLs (i.e. ARSA, B4GALT6, GAL3ST1, GALC, GBA, GLA, GLB1, GLB1L, NEU1, NEU2, UGCG, UGT8) could account for differential binding of F4 ETEC and their fimbriae. RT-PCR could not reveal any differential expression of the 12 genes in the jejunum of F4 receptor-positive (F4R(+)) and F4 receptor-negative (F4R(-)) pigs. Sequencing the complete open reading frame of the 11 expressed genes (NEU2 was not expressed) identified 72 mutations. Although some of them might have a structural effect, none of them could be associated with a F4R phenotype. We conclude that no regulatory or structural variation in any of the investigated genes is responsible for the genetic susceptibility of pigs towards F4 ETEC.

  19. Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains

    International Nuclear Information System (INIS)

    Nomura, Sayaka; Iwata, Satoshi; Hatano, Ryo; Komiya, Eriko; Dang, Nam H.; Iwao, Noriaki; Ohnuma, Kei; Morimoto, Chikao

    2016-01-01

    CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis. -- Highlights: •Knockdown of CD82 decreases EC migration, proliferation and angiogenesis. •Anti-CD82 mAb 4F9 inhibits EC migration, proliferation and angiogenesis. •4F9 inhibits VEGFR2 phosphorylation via control of CD82 distribution in lipid rafts.

  20. Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Sayaka; Iwata, Satoshi; Hatano, Ryo [Division of Clinical Immunology, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Komiya, Eriko [Department of Therapy Development and Innovation for Immune Disorders and Cancers, Graduate School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Dang, Nam H. [Division of Hematology/Oncology, University of Florida, 1600 SW Archer Road- Box 100278, Room MSB M410A, Gainesville, FL, 32610 (United States); Iwao, Noriaki [Department of Hematology, School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Ohnuma, Kei, E-mail: kohnuma@juntendo.ac.jp [Department of Rheumatology and Allergy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Morimoto, Chikao [Division of Clinical Immunology, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Department of Rheumatology and Allergy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan)

    2016-05-20

    CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis. -- Highlights: •Knockdown of CD82 decreases EC migration, proliferation and angiogenesis. •Anti-CD82 mAb 4F9 inhibits EC migration, proliferation and angiogenesis. •4F9 inhibits VEGFR2 phosphorylation via control of CD82 distribution in lipid rafts.

  1. Age-associated changes in rich-club organisation in autistic and neurotypical human brains.

    Science.gov (United States)

    Watanabe, Takamitsu; Rees, Geraint

    2015-11-05

    Macroscopic structural networks in the human brain have a rich-club architecture comprising both highly inter-connected central regions and sparsely connected peripheral regions. Recent studies show that disruption of this functionally efficient organisation is associated with several psychiatric disorders. However, despite increasing attention to this network property, whether age-associated changes in rich-club organisation occur during human adolescence remains unclear. Here, analysing a publicly shared diffusion tensor imaging dataset, we found that, during adolescence, brains of typically developing (TD) individuals showed increases in rich-club organisation and inferred network functionality, whereas individuals with autism spectrum disorders (ASD) did not. These differences between TD and ASD groups were statistically significant for both structural and functional properties. Moreover, this typical age-related changes in rich-club organisation were characterised by progressive involvement of the right anterior insula. In contrast, in ASD individuals, did not show typical increases in grey matter volume, and this relative anatomical immaturity was correlated with the severity of ASD social symptoms. These results provide evidence that rich-club architecture is one of the bases of functionally efficient brain networks underpinning complex cognitive functions in adult human brains. Furthermore, our findings suggest that immature rich-club organisation might be associated with some neurodevelopmental disorders.

  2. Acoustic richness modulates the neural networks supporting intelligible speech processing.

    Science.gov (United States)

    Lee, Yune-Sang; Min, Nam Eun; Wingfield, Arthur; Grossman, Murray; Peelle, Jonathan E

    2016-03-01

    The information contained in a sensory signal plays a critical role in determining what neural processes are engaged. Here we used interleaved silent steady-state (ISSS) functional magnetic resonance imaging (fMRI) to explore how human listeners cope with different degrees of acoustic richness during auditory sentence comprehension. Twenty-six healthy young adults underwent scanning while hearing sentences that varied in acoustic richness (high vs. low spectral detail) and syntactic complexity (subject-relative vs. object-relative center-embedded clause structures). We manipulated acoustic richness by presenting the stimuli as unprocessed full-spectrum speech, or noise-vocoded with 24 channels. Importantly, although the vocoded sentences were spectrally impoverished, all sentences were highly intelligible. These manipulations allowed us to test how intelligible speech processing was affected by orthogonal linguistic and acoustic demands. Acoustically rich speech showed stronger activation than acoustically less-detailed speech in a bilateral temporoparietal network with more pronounced activity in the right hemisphere. By contrast, listening to sentences with greater syntactic complexity resulted in increased activation of a left-lateralized network including left posterior lateral temporal cortex, left inferior frontal gyrus, and left dorsolateral prefrontal cortex. Significant interactions between acoustic richness and syntactic complexity occurred in left supramarginal gyrus, right superior temporal gyrus, and right inferior frontal gyrus, indicating that the regions recruited for syntactic challenge differed as a function of acoustic properties of the speech. Our findings suggest that the neural systems involved in speech perception are finely tuned to the type of information available, and that reducing the richness of the acoustic signal dramatically alters the brain's response to spoken language, even when intelligibility is high. Copyright © 2015 Elsevier

  3. On the nature of the Cu-rich aggregates in brain astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Brendan; Robison, Gregory; Osborn, Jenna; Kay, Martin; Thompson, Peter; Davis, Katherine; Zakharova, Taisiya; Antipova, Olga; Pushkar, Yulia

    2017-04-01

    Fulfilling a bevy of biological roles, copper is an essential metal for healthy brain function. Cu dyshomeostasis has been demonstrated to be involved in some neurological conditions including Menkes and Alzheimer’s diseases. We have previously reported localized Cu-rich aggregates in astrocytes of the subventricular zone (SVZ) in rodent brains with Cu concentrations in the hundreds of millimolar. Metallothionein, a cysteine-rich protein critical to metal homeostasis and known to participate in a variety of neuroprotective and neuroregenerative processes, was proposed as a binding protein. Here, we present an analysis of metallothionein(1,2) knockout (MTKO) mice and age-matched controls using X-ray fluorescence microscopy. In large structures such as the corpus callosum, cortex, and striatum, there is no significant difference in Cu, Fe, or Zn concentrations in MTKO mice compared to age-matched controls. In the astrocyte-rich subventricular zone where Cu-rich aggregates reside, approximately 1/3 as many Cu-rich aggregates persist in MTKO mice resulting in a decrease in periventricular Cu concentration. Aggregates in both wild-type and MTKO mice show XANES spectra characteristic of CuxSy multimetallic clusters and have similar [S]/[Cu] ratios. Consistent with assignment as a CuxSy multimetallic cluster, the astrocyte-rich SVZ of both MTKO and wild-type mice exhibit autofluorescent bodies, though MTKO mice exhibit fewer. Furthermore, XRF imaging of Au-labeled lysosomes and ubiquitin demonstrates a lack of co-localization with Cu-rich aggregates suggesting they are not involved in a degradation pathway. Overall, these data suggest that Cu in aggregates is bound by either metallothionein-3 or a yet unknown protein similar to metallothionein.

  4. Implementing a Java Based GUI for RICH Detector Analysis

    Science.gov (United States)

    Lendacky, Andrew; Voloshin, Andrew; Benmokhtar, Fatiha

    2016-09-01

    The CLAS12 detector at Thomas Jefferson National Accelerator Facility (TJNAF) is undergoing an upgrade. One of the improvements is the addition of a Ring Imaging Cherenkov (RICH) detector to improve particle identification in the 3-8 GeV/c momentum range. Approximately 400 multi anode photomultiplier tubes (MAPMTs) are going to be used to detect Cherenkov Radiation in the single photoelectron spectra (SPS). The SPS of each pixel of all MAPMTs have been fitted to a mathematical model of roughly 45 parameters for 4 HVs, 3 OD. Out of those parameters, 9 can be used to evaluate the PMTs performance and placement in the detector. To help analyze data when the RICH is operational, a GUI application was written in Java using Swing and detector packages from TJNAF. To store and retrieve the data, a MySQL database program was written in Java using the JDBC package. Using the database, the GUI pulls the values and produces histograms and graphs for a selected PMT at a specific HV and OD. The GUI will allow researchers to easily view a PMT's performance and efficiency to help with data analysis and ring reconstruction when the RICH is finished.

  5. Scanning technology selection impacts acceptability and usefulness of image-rich content

    Directory of Open Access Journals (Sweden)

    Kristine M. Alpi

    2016-01-01

    Full Text Available Objective: Clinical and research usefulness of articles can depend on image quality. This study addressed whether scans of figures in black and white (B&W, grayscale, or color, or portable document format (PDF to tagged image file format (TIFF conversions as provided by interlibrary loan or document delivery were viewed as acceptable or useful by radiologists or pathologists. Methods: Residency coordinators selected eighteen figures from studies from radiology, clinical pathology, and anatomic pathology journals.With original PDF controls, each figure was prepared in three or four experimental conditions: PDF conversion to TIFF, and scans from print in B&W, grayscale, and color. Twelve independent observers indicated whether they could identify the features and whether the image quality was acceptable. They also ranked all the experimental conditions of each figure in terms of usefulness. Results: Of 982 assessments of 87 anatomic pathology, 83 clinical pathology, and 77 radiology images, 471 (48% were unidentifiable. Unidentifiability of originals (4% and conversions (10% was low. For scans, unidentifiability ranged from 53% for color, to 74% for grayscale, to 97% for B&W. Of 987 responses about acceptability (n¼405, 41% were said to be unacceptable, 97% of B&W, 66% of grayscale, 41% of color, and 1% of conversions. Hypothesized order (original, conversion, color, grayscale, B&W matched 67% of rankings (n¼215. Conclusions: PDF to TIFF conversion provided acceptable content. Color images are rarely useful in grayscale (12% or B&W (less than 1%. Acceptability of grayscale scans of noncolor originals was 52%. Digital originals are needed for most images. Print images in color or grayscale should be scanned using those modalities.

  6. Segregation of lipids near acetylcholine-receptor channels imaged by cryo-EM

    Directory of Open Access Journals (Sweden)

    Nigel Unwin

    2017-07-01

    Full Text Available Rapid communication at the chemical synapse depends on the action of ion channels residing in the postsynaptic membrane. The channels open transiently upon the binding of a neurotransmitter released from the presynaptic nerve terminal, eliciting an electrical response. Membrane lipids also play a vital but poorly understood role in this process of synaptic transmission. The present study examines the lipid distribution around nicotinic acetylcholine (ACh receptors in tubular vesicles made from postsynaptic membranes of the Torpedo ray, taking advantage of the recent advances in cryo-EM. A segregated distribution of lipid molecules is found in the outer leaflet of the bilayer. Apparent cholesterol-rich patches are located in specific annular regions next to the transmembrane helices and also in a more extended `microdomain' between the apposed δ subunits of neighbouring receptors. The particular lipid distribution can be interpreted straightforwardly in relation to the gating movements revealed by an earlier time-resolved cryo-EM study, in which the membranes were exposed briefly to ACh. The results suggest that in addition to stabilizing the protein, cholesterol may play a mechanical role by conferring local rigidity to the membrane so that there is productive coupling between the extracellular and membrane domains, leading to opening of the channel.

  7. Monitoring of absolute mirror alignment at COMPASS RICH-1 detector

    Energy Technology Data Exchange (ETDEWEB)

    Alexeev, M. [INFN, Sezione di Torino and University of East Piemonte, Alessandria (Italy); INFN, Sezione di Trieste and University of Bari, Bari (Italy); Birsa, R. [INFN, Sezione di Trieste, Trieste (Italy); Bradamante, F.; Bressan, A. [INFN, Sezione di Trieste and University of Trieste, Trieste (Italy); Chiosso, M. [INFN, Sezione di Torino and University of Torino, Torino (Italy); Ciliberti, P. [INFN, Sezione di Trieste and University of Trieste, Trieste (Italy); Dalla Torre, S. [INFN, Sezione di Trieste, Trieste (Italy); Denisov, O. [INFN, Sezione di Torino, Torino (Italy); Duic, V. [INFN, Sezione di Trieste and University of Trieste, Trieste (Italy); Ferrero, A. [INFN, Sezione di Torino and University of Torino, Torino (Italy); Finger, M.; Finger, M. [Charles University, Prague (Czech Republic); JINR, Dubna (Russian Federation); Gayde, J.Ch. [CERN, European Organization for Nuclear Research, Geneva (Switzerland); Giorgi, M. [INFN, Sezione di Trieste and University of Trieste, Trieste (Italy); Gobbo, B.; Levorato, S. [INFN, Sezione di Trieste, Trieste (Italy); Maggiora, A. [INFN, Sezione di Torino, Torino (Italy); Martin, A. [INFN, Sezione di Trieste and University of Trieste, Trieste (Italy); Menon, G. [INFN, Sezione di Trieste, Trieste (Italy); Panzieri, D. [INFN, Sezione di Torino and University of East Piemonte, Alessandria (Italy); and others

    2014-12-01

    The gaseous COMPASS RICH-1 detector uses two spherical mirror surfaces, segmented into 116 individual mirrors, to focus the Cherenkov photons onto the detector plane. Any mirror misalignment directly affects the detector resolution. The on-line Continuous Line Alignment and Monitoring (CLAM) photogrammetry-based method has been implemented to measure the alignment of individual mirrors which can be characterized by the center of curvature. The mirror wall reflects a regular grid of retroreflective strips placed inside the detector vessel. Then, the position of each mirror is determined from the image of the grid reflection. The images are collected by four cameras. Any small mirror misalignment results in changes of the grid lines’ positions in the image. The accuracy limits of the CLAM method were checked by laser interferometry and are below 0.1 mrad.

  8. Alfalfa discovery of the nearby gas-rich dwarf galaxy Leo P. IV. Distance measurement from LBT optical imaging

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W.; Skillman, Evan D.; Berg, Danielle [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Salzer, John J.; Rhode, Katherine L. [Department of Astronomy, Indiana University, 727 East 3rd Street, Bloomington, IN 47405 (United States); Adams, Elizabeth A. K.; Giovanelli, Riccardo; Haynes, Martha P. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Dolphin, Andrew, E-mail: kmcquinn@astro.umn.edu, E-mail: skillman@astro.umn.edu, E-mail: berg@astro.umn.edu, E-mail: jcannon@macalester.edu, E-mail: rhode@astro.indiana.edu, E-mail: slaz@astro.indiana.edu, E-mail: betsey@astro.cornell.edu, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States)

    2013-12-01

    Leo P is a low-luminosity dwarf galaxy discovered through the blind H I Arecibo Legacy Fast ALFA survey. The H I and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with both active star formation and an underlying older population, as well as an extremely low oxygen abundance. Here, we measure the distance to Leo P by applying the tip of the red giant branch (TRGB) distance method to photometry of the resolved stellar population from new Large Binocular Telescope V and I band imaging. We measure a distance modulus of 26.19{sub −0.50}{sup +0.17} mag corresponding to a distance of 1.72{sub −0.40}{sup +0.14} Mpc. Although our photometry reaches 3 mag below the TRGB, the sparseness of the red giant branch yields higher uncertainties on the lower limit of the distance. Leo P is outside the Local Group with a distance and velocity consistent with the local Hubble flow. While located in a very low-density environment, Leo P lies within ∼0.5 Mpc of a loose association of dwarf galaxies which include NGC 3109, Antlia, Sextans A, and Sextans B, and 1.1 Mpc away from its next nearest neighbor, Leo A. Leo P is one of the lowest metallicity star-forming galaxies known in the nearby universe, comparable in metallicity to I Zw 18 and DDO 68, but with stellar characteristics similar to dwarf spheriodals (dSphs) in the Local Volume such as Carina, Sextans, and Leo II. Given its physical properties and isolation, Leo P may provide an evolutionary link between gas-rich dwarf irregular galaxies and dSphs that have fallen into a Local Group environment and been stripped of their gas.

  9. Expression of Shiga toxin 2e glycosphingolipid receptors of primary porcine brain endothelial cells and toxin-mediated breakdown of the blood-brain barrier.

    Science.gov (United States)

    Meisen, Iris; Rosenbrück, Regina; Galla, Hans-Joachim; Hüwel, Sabine; Kouzel, Ivan U; Mormann, Michael; Karch, Helge; Müthing, Johannes

    2013-06-01

    Shiga toxin (Stx) 2e, released by certain Stx-producing Escherichia coli, is presently the best characterized virulence factor responsible for pig edema disease, which is characterized by hemorrhagic lesions, neurological disorders and often fatal outcomes. Although Stx2e-mediated brain vascular injury is the key event in development of neurologic signs, the glycosphingolipid (GSL) receptors of Stx2e and toxin-mediated impairment of pig brain endothelial cells have not been investigated so far. Here, we report on the detailed structural characterization of Stx2e receptors globotriaosylceramide (Gb3Cer) and globotetraosylceramide (Gb4Cer), which make up the major neutral GSLs in primary porcine brain capillary endothelial cells (PBCECs). Various Gb3Cer and Gb4Cer lipoforms harboring sphingenine (d18:1) or sphinganine (d18:0) and mostly a long-chain fatty acid (C20-C24) were detected. A notable batch-to-batch heterogeneity of primary endothelial cells was observed regarding the extent of ceramide hydroxylation of Gb3Cer or Gb4Cer species. Gb3Cer, Gb4Cer and sphingomyelin preferentially distribute to detergent-resistant membrane fractions and can be considered lipid raft markers in PBCECs. Moreover, we employed an in vitro model of the blood-brain barrier (BBB), which exhibited strong cytotoxic effects of Stx2e on the endothelial monolayer and a rapid collapse of the BBB. These data strongly suggest the involvement of Stx2e in cerebral vascular damage with resultant neurological disturbance characteristic of edema disease.

  10. Imaging characteristics of two subtypes of congenital hemangiomas: rapidly involuting congenital hemangiomas and non-involuting congenital hemangiomas

    International Nuclear Information System (INIS)

    Gorincour, Guillaume; Rypens, Francoise; Garel, Laurent; Dubois, Josee; Kokta, Victor; Powell, Julie

    2005-01-01

    Common infantile hemangiomas (COMMON) occur in approximately 10% of infants by the age of 1 year, with a female predominance. Some hemangiomas can be fully developed at birth and are thus called congenital hemangiomas (CH). Within this population, two courses have been identified: rapidly involuting CH (RICH) and non-involuting CH (NICH). Little has been reported on the clinical prognosis and imaging features of these entities. To describe the imaging characteristics of two subtypes of CH, i.e. RICH and NICH, and to compare them with COMMON. We retrospectively gathered data on 26 children presenting with CH, i.e. lesions fully developed at birth. These lesions were divided into two groups according to the clinical course: suspected RICH (n=8) and suspected NICH (n=18). We used US, CT or MRI and angiography to identify the gross anatomy and structure and the vascularization. Imaging findings were compared with the clinical course and pathology results, when available. The imaging findings in these patients were compared retrospectively with those in 26 patients with COMMON randomly chosen from the database of our multidisciplinary clinic. When compared with COMMON imaging characteristics, NICH and RICH had distinctive features on US such as being heterogeneous (72% of NICH and 62.5% of RICH vs 42.3% of COMMON), visible vessels (72% of NICH and 62.5% of RICH vs 15.4% of COMMON), calcifications (17% of NICH and 37.5% of RICH vs no case of COMMON). On CT and/or MRI, we compared imaging features such as well-defined limits (67% of NICH and 60% of RICH vs 100% of COMMON), and fat stranding (29.4% of NICH and RICH vs 7.7% of COMMON). Distinctive imaging characteristics are observed in cases of CH with US findings of visible vessels and calcifications statistically significant. (orig.)

  11. Structural and functional rich club organization of the brain in children and adults.

    Directory of Open Access Journals (Sweden)

    David S Grayson

    Full Text Available Recent studies using Magnetic Resonance Imaging (MRI have proposed that the brain's white matter is organized as a rich club, whereby the most highly connected regions of the brain are also highly connected to each other. Here we use both functional and diffusion-weighted MRI in the human brain to investigate whether the rich club phenomena is present with functional connectivity, and how this organization relates to the structural phenomena. We also examine whether rich club regions serve to integrate information between distinct brain systems, and conclude with a brief investigation of the developmental trajectory of rich-club phenomena. In agreement with prior work, both adults and children showed robust structural rich club organization, comprising regions of the superior medial frontal/dACC, medial parietal/PCC, insula, and inferior temporal cortex. We also show that these regions were highly integrated across the brain's major networks. Functional brain networks were found to have rich club phenomena in a similar spatial layout, but a high level of segregation between systems. While no significant differences between adults and children were found structurally, adults showed significantly greater functional rich club organization. This difference appeared to be driven by a specific set of connections between superior parietal, insula, and supramarginal cortex. In sum, this work highlights the existence of both a structural and functional rich club in adult and child populations with some functional changes over development. It also offers a potential target in examining atypical network organization in common developmental brain disorders, such as ADHD and Autism.

  12. The read-out electronics of the AMS prototype RICH detector

    International Nuclear Information System (INIS)

    Gallin-Martel, L.; Eraud, L.; Pouxe, J.; Aguayo de Hoyos, P.; Marin Munoz, J.; Martinez Botella, G.

    2003-01-01

    A Ring Imaging Cherenkov (RICH) counter dedicated to the AMS experiment is under development. An integrated circuit has been designed with the Austriamicrosystems 0.6 πm CMOS technology to process the signals of the 16 anode PMTs used in the photon detection. To improve the detector compactness, the read out electronics is placed very close to the PMTs. This lead to the design of a detection cell that comprises: a light guide, a PMT, a high voltage divider, an analog front end chip and an analog to digital converter. The analog front-end chips were extensively and successfully tested in a laboratory environment, 96 of them are now mounted on the RICH prototype. Tests with cosmic rays have started. Ion beam tests are planed in a near future. (authors)

  13. Clathrin- and caveolin-independent entry of human papillomavirus type 16--involvement of tetraspanin-enriched microdomains (TEMs.

    Directory of Open Access Journals (Sweden)

    Gilles Spoden

    Full Text Available BACKGROUND: Infectious entry of human papillomaviruses into their host cells is an important step in the viral life cycle. For cell binding these viruses use proteoglycans as initial attachment sites. Subsequent transfer to a secondary receptor molecule seems to be involved in virus uptake. Depending on the papillomavirus subtype, it has been reported that entry occurs by clathrin- or caveolin-mediated mechanisms. Regarding human papillomavirus type 16 (HPV16, the primary etiologic agent for development of cervical cancer, clathrin-mediated endocytosis was described as infectious entry pathway. METHODOLOGY/PRINCIPAL FINDINGS: Using immunofluorescence and infection studies we show in contrast to published data that infectious entry of HPV16 occurs in a clathrin- and caveolin-independent manner. Inhibition of clathrin- and caveolin/raft-dependent endocytic pathways by dominant-negative mutants and siRNA-mediated knockdown, as well as inhibition of dynamin function, did not impair infection. Rather, we provide evidence for involvement of tetraspanin-enriched microdomains (TEMs in HPV16 endocytosis. Following cell attachment, HPV16 particles colocalized with the tetraspanins CD63 and CD151 on the cell surface. Notably, tetraspanin-specific antibodies and siRNA inhibited HPV16 cell entry and infection, confirming the importance of TEMs for infectious endocytosis of HPV16. CONCLUSIONS/SIGNIFICANCE: Tetraspanins fulfill various roles in the life cycle of a number of important viral pathogens, including human immunodeficiency virus (HIV and hepatitis C virus (HCV. However, their involvement in endocytosis of viral particles has not been proven. Our data indicate TEMs as a novel clathrin- and caveolin-independent invasion route for viral pathogens and especially HPV16.

  14. Magnesium-rich Basalts on Mercury

    Science.gov (United States)

    Martel, L. M. V.

    2013-05-01

    X-ray and gamma-ray spectrometers on NASA's MESSENGER spacecraft are making key measurements regarding the composition and properties of the surface of Mercury, allowing researchers to more clearly decipher the planet's formation and geologic history. The origin of the igneous rocks in the crust of Mercury is the focus of recent research by Karen Stockstill-Cahill and Tim McCoy (National Museum of Natural History, Smithsonian Institution), along with Larry Nittler and Shoshana Weider (Carnegie Institution of Washington) and Steven Hauck II (Case Western Reserve University). Using the well-known MELTS computer code Stockstill-Cahill and coauthors worked with MESSENGER-derived and rock-analog compositions to constrain petrologic models of the lavas that erupted on the surface of Mercury. Rock analogs included a partial melt of the Indarch meteorite and a range of Mg-rich terrestrial rocks. Their work shows the lavas on Mercury are most similar to terrestrial magnesian basalt (with lowered FeO content). The implications of the modeling are that Mg-rich lavas came from high-temperature sources in Mercury's mantle and erupted at high temperature with exceptionally low viscosity into thinly bedded and laterally extensive flows, concepts open to further evaluation by laboratory experiments and by geologic mapping of Mercury's surface using MESSENGER's imaging system and laser altimeter to document flow features and dimensions.

  15. Image quality transfer and applications in diffusion MRI

    DEFF Research Database (Denmark)

    Alexander, Daniel C.; Zikic, Darko; Ghosh, Aurobrata

    2017-01-01

    This paper introduces a new computational imaging technique called image quality transfer (IQT). IQT uses machine learning to transfer the rich information available from one-off experimental medical imaging devices to the abundant but lower-quality data from routine acquisitions. The procedure u...

  16. The LHCb RICH system: current detector performance and status of the upgrade program

    CERN Document Server

    Fiorini, Massimiliano

    2016-01-01

    LHCb is a precision experiment devoted to the study of CP violation and rare decays of b and c quarks, and to the search for new physics beyond the Standard Model at the Large Hadron Collider (LHC) at CERN. The Ring-Imaging Cherenkov (RICH) system is a key component of the LHCb experiment: it consists of two RICH detectors that provide charged particle identification over a wide momentum range (2-100 GeV/c) and angular acceptance (15-300 mrad). The LHCb RICH system has been performing extremely well during Run 1 and is providing the LHCb experiment also in Run 2 with a robust, reliable and precise particle identification system. Performance of the RICH detectors measured from data will be presented, with special reference to its dependence on calibration parameters and event multiplicities. The LHCb experiment is preparing for an upgrade during the second LHC long shutdown (2019-2020) in order to fully exploit the LHC flavour physics potential. A five-fold increase in instantaneous luminosity is foreseen reac...

  17. Quantitative evaluation of high intensity signal on MIP images of carotid atherosclerotic plaques from routine TOF-MRA reveals elevated volumes of intraplaque hemorrhage and lipid rich necrotic core

    Directory of Open Access Journals (Sweden)

    Yamada Kiyofumi

    2012-11-01

    Full Text Available Abstract Background Carotid intraplaque hemorrhage (IPH and lipid rich necrotic core (LRNC have been associated with accelerated plaque growth, luminal narrowing, future surface disruption and development of symptomatic events. The aim of this study was to evaluate the quantitative relationships between high intensity signals (HIS in the plaque on TOF-MRA and IPH or LRNC volumes as measured by multicontrast weighted CMR. Methods Seventy six patients with a suspected carotid artery stenosis or carotid plaque by ultrasonography underwent multicontrast carotid CMR. HIS presence and volume were measured from TOF-MRA MIP images while IPH and LRNC volumes were separately measured from multicontrast CMR. Results For detecting IPH, HIS on MIP images overall had high specificity (100.0%, 95% CI: 93.0 – 100.0% but relatively low sensitivity (32%, 95% CI: 20.8 – 47.9%. However, the sensitivity had a significant increasing relationship with underlying IPH volume (p = 0.033 and degree of stenosis (p = 0.022. Mean IPH volume was 2.7 times larger in those with presence of HIS than in those without (142.8 ± 97.7 mm3 vs. 53.4 ± 56.3 mm3, p = 0.014. Similarly, mean LRNC volume was 3.4 times larger in those with HIS present (379.8 ± 203.4 mm3 vs. 111.3 ± 122.7 mm3, p = 0.001. There was a strong correlation between the volume of the HIS region and the IPH volume measured from multicontrast CMR (r = 0.96, p  Conclusion MIP images are easily reformatted from three minute, routine, clinical TOF sequences. High intensity signals in carotid plaque on TOF-MRA MIP images are associated with increased intraplaque hemorrhage and lipid-rich necrotic core volumes. The technique is most sensitive in patients with moderate to severe stenosis.

  18. ISO far-infrared observations of rich galaxy clusters II. Sersic 159-03

    DEFF Research Database (Denmark)

    Hansen, Lene; Jørgensen, H.E.; Nørgaard-Nielsen, Hans Ulrik

    2000-01-01

    In a series of papers we investigate far-infrared emission from rich galaxy clusters. Maps have been obtained by ISO at 60 mu m, 100 mu m, 135 mu m, and 200 mu m using the PHT-C camera. Ground based imaging and spectroscopy were also acquired. Here we present the results for the cooling flow...

  19. ASSOCIATION OF {sup 3}He-RICH SOLAR ENERGETIC PARTICLES WITH LARGE-SCALE CORONAL WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Bučík, Radoslav [Institut für Astrophysik, Georg-August-Universität Göttingen, D-37077, Göttingen (Germany); Innes, Davina E. [Max-Planck-Institut für Sonnensystemforschung, D-37077, Göttingen (Germany); Mason, Glenn M. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Wiedenbeck, Mark E., E-mail: bucik@mps.mpg.de [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2016-12-10

    Small, {sup 3}He-rich solar energetic particle (SEP) events have been commonly associated with extreme-ultraviolet (EUV) jets and narrow coronal mass ejections (CMEs) that are believed to be the signatures of magnetic reconnection, involving field lines open to interplanetary space. The elemental and isotopic fractionation in these events are thought to be caused by processes confined to the flare sites. In this study, we identify 32 {sup 3}He-rich SEP events observed by the Advanced Composition Explorer , near the Earth, during the solar minimum period 2007–2010, and we examine their solar sources with the high resolution Solar Terrestrial Relations Observatory ( STEREO ) EUV images. Leading the Earth, STEREO -A has provided, for the first time, a direct view on {sup 3}He-rich flares, which are generally located on the Sun’s western hemisphere. Surprisingly, we find that about half of the {sup 3}He-rich SEP events in this survey are associated with large-scale EUV coronal waves. An examination of the wave front propagation, the source-flare distribution, and the coronal magnetic field connections suggests that the EUV waves may affect the injection of {sup 3}He-rich SEPs into interplanetary space.

  20. The leucine-rich repeat structure.

    Science.gov (United States)

    Bella, J; Hindle, K L; McEwan, P A; Lovell, S C

    2008-08-01

    The leucine-rich repeat is a widespread structural motif of 20-30 amino acids with a characteristic repetitive sequence pattern rich in leucines. Leucine-rich repeat domains are built from tandems of two or more repeats and form curved solenoid structures that are particularly suitable for protein-protein interactions. Thousands of protein sequences containing leucine-rich repeats have been identified by automatic annotation methods. Three-dimensional structures of leucine-rich repeat domains determined to date reveal a degree of structural variability that translates into the considerable functional versatility of this protein superfamily. As the essential structural principles become well established, the leucine-rich repeat architecture is emerging as an attractive framework for structural prediction and protein engineering. This review presents an update of the current understanding of leucine-rich repeat structure at the primary, secondary, tertiary and quaternary levels and discusses specific examples from recently determined three-dimensional structures.

  1. Readout ASICs and Electronics for the 144-channel HAPDs for the Aerogel RICH at Belle II

    Science.gov (United States)

    Nishida, S.; Adachi, I.; Ikeda, H.; Hara, K.; Iijima, T.; Iwata, S.; Korpar, S.; Križan, P.; Kuroda, E.; Pestotnik, R.; Seljak, A.; Sumiyoshi, T.; Takagaki, H.

    The particle identification (PID) device in the endcap of the Belle detector will be upgraded to a ring imaging Cherenkov counter (RICH) using aerogel as a radiator at the Belle II experiment. We develop the electronics to read out the 70,000 channels of hit information from the 144-channel hybrid avalanche photodetectors (HAPD), of the aerogel RICH detector. A readout ASIC is developed to digitize the HAPD signals, and was used in a beam test with the prototype detector. The performance and plan of the ASIC is reported in this study. We have also designed the readout electronics for the aerogel RICH, which consist of front-end boards with the ASICs merger boards to collect data from the front-end boards. A front-end board that fits in the actual available space for the aerogel RICH electronics was produced.

  2. The CAPRICE RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Basini, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Codino, A.; Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.; Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy)

    1995-09-01

    A compact RICH detector has been developed and used for particle identification in a balloon borne spectrometer to measure the flux of antimatter in the cosmic radiation. This is the first RICH detector ever used in space experiments that is capable of detecting unit charged particles, such as antiprotons. The RICH and all other detectors performed well during the 27 hours long flight.

  3. Rich club analysis in the Alzheimer's disease connectome reveals a relatively undisturbed structural core network.

    Science.gov (United States)

    Daianu, Madelaine; Jahanshad, Neda; Nir, Talia M; Jack, Clifford R; Weiner, Michael W; Bernstein, Matt A; Thompson, Paul M

    2015-08-01

    Diffusion imaging can assess the white matter connections within the brain, revealing how neural pathways break down in Alzheimer's disease (AD). We analyzed 3-Tesla whole-brain diffusion-weighted images from 202 participants scanned by the Alzheimer's Disease Neuroimaging Initiative-50 healthy controls, 110 with mild cognitive impairment (MCI) and 42 AD patients. From whole-brain tractography, we reconstructed structural brain connectivity networks to map connections between cortical regions. We tested whether AD disrupts the "rich club" - a network property where high-degree network nodes are more interconnected than expected by chance. We calculated the rich club properties at a range of degree thresholds, as well as other network topology measures including global degree, clustering coefficient, path length, and efficiency. Network disruptions predominated in the low-degree regions of the connectome in patients, relative to controls. The other metrics also showed alterations, suggesting a distinctive pattern of disruption in AD, less pronounced in MCI, targeting global brain connectivity, and focusing on more remotely connected nodes rather than the central core of the network. AD involves severely reduced structural connectivity; our step-wise rich club coefficients analyze points to disruptions predominantly in the peripheral network components; other modalities of data are needed to know if this indicates impaired communication among non rich club regions. The highly connected core was relatively preserved, offering new evidence on the neural basis of progressive risk for cognitive decline. © 2015 Wiley Periodicals, Inc.

  4. Light composite mirrors for RICH detectors Production, characterisation and stability tests

    CERN Document Server

    Bellunato, T F; Calvi, M; Chignoli, F; D'Ambrosio, C; Matteuzzi, C; Musy, M; Perego, D L

    2005-01-01

    The production of lightweight composite mirror prototypes suitable for application in Ring Imaging Cherenkov (RICH) detectors is described. The goal is the use of such mirrors whenever material budget is a concern. The manufacturing technique is described in detail, together with the achieved results in terms of optical quality. Several ageing tests have been performed on some of the prototypes. The results of these tests are reported.

  5. Effect of carbo-nitride-rich and oxide-rich inclusions on the pitting susceptibility of depleted uranium

    International Nuclear Information System (INIS)

    Pu, Zhen; Chen, Xianglin; Meng, Xiandong; Wu, Yanping; Shen, Liang; Wang, Qingfu; Liu, Tianwei; Shuai, Maobing

    2017-01-01

    Highlights: •The Volta potential differences relative to the matrix are positive for both types of inclusions. •Both types of inclusions are cathodic in the “inclusion/matrix” microgalvanic couples. •The oxide-rich inclusions show a larger Volta potential value of about 115 mV than the carbo-nitride-rich inclusions. •The oxide-rich inclusions give stronger local galvanic coupling with the matrix. •The oxide-rich inclusions are more predisposed to initiate pitting corrosion. -- Abstract: The effects of carbo-nitride-rich and oxide-rich inclusions on the pitting susceptibility of depleted uranium were investigated by electrochemical corrosion measurements, optical microscopy, scanning Kelvin probe force microscopy (SKPFM), and SEM. The results of the potentiodynamic polarization tests suggest that oxide-rich inclusions are more likely to induce pitting corrosion than carbo-nitride-rich inclusions. This enhanced corrosion may be explained by the strong local galvanic coupling between the oxide-rich inclusion and the surrounding matrix, which, from the sight of SKPFM analysis, exhibits a 115 V higher Volta potential than the coupling between the carbo-nitride-rich inclusions and the matrix, respectively.

  6. Cherenkov angle and charge reconstruction with the RICH detector of the AMS experiment

    CERN Document Server

    Barão, F; Borges, J; Gonçalves, P; Pimenta, M; Pérez, I

    2003-01-01

    The Alpha Magnetic Spectrometer experiment to be installed on the International Space Station will be equipped with a proximity focusing Ring Imaging Cherenkov (RICH) detector, for measurements of particle electric charge and velocity. In this note, two possible methods for reconstructing the Cherenkov angle and the electric charge with the RICH are discussed. A Likelihood method for the Cherenkov angle reconstruction was applied leading to a velocity determination for protons with a resolution of around 0.1%. The existence of a large fraction of background photons which can vary from event to event implied a charge reconstruction method based on an overall efficiency estimation on an event-by-event basis.

  7. Quantitative evaluation of high intensity signal on MIP images of carotid atherosclerotic plaques from routine TOF-MRA reveals elevated volumes of intraplaque hemorrhage and lipid rich necrotic core.

    Science.gov (United States)

    Yamada, Kiyofumi; Song, Yan; Hippe, Daniel S; Sun, Jie; Dong, Li; Xu, Dongxiang; Ferguson, Marina S; Chu, Baocheng; Hatsukami, Thomas S; Chen, Min; Zhou, Cheng; Yuan, Chun

    2012-11-29

    Carotid intraplaque hemorrhage (IPH) and lipid rich necrotic core (LRNC) have been associated with accelerated plaque growth, luminal narrowing, future surface disruption and development of symptomatic events. The aim of this study was to evaluate the quantitative relationships between high intensity signals (HIS) in the plaque on TOF-MRA and IPH or LRNC volumes as measured by multicontrast weighted CMR. Seventy six patients with a suspected carotid artery stenosis or carotid plaque by ultrasonography underwent multicontrast carotid CMR. HIS presence and volume were measured from TOF-MRA MIP images while IPH and LRNC volumes were separately measured from multicontrast CMR. For detecting IPH, HIS on MIP images overall had high specificity (100.0%, 95% CI: 93.0 - 100.0%) but relatively low sensitivity (32%, 95% CI: 20.8 - 47.9%). However, the sensitivity had a significant increasing relationship with underlying IPH volume (p = 0.033) and degree of stenosis (p = 0.022). Mean IPH volume was 2.7 times larger in those with presence of HIS than in those without (142.8 ± 97.7 mm(3) vs. 53.4 ± 56.3 mm(3), p = 0.014). Similarly, mean LRNC volume was 3.4 times larger in those with HIS present (379.8 ± 203.4 mm(3) vs. 111.3 ± 122.7 mm(3), p = 0.001). There was a strong correlation between the volume of the HIS region and the IPH volume measured from multicontrast CMR (r = 0.96, p routine, clinical TOF sequences. High intensity signals in carotid plaque on TOF-MRA MIP images are associated with increased intraplaque hemorrhage and lipid-rich necrotic core volumes. The technique is most sensitive in patients with moderate to severe stenosis.

  8. Proton-rich nuclear statistical equilibrium

    International Nuclear Information System (INIS)

    Seitenzahl, I.R.; Timmes, F.X.; Marin-Lafleche, A.; Brown, E.; Magkotsios, G.; Truran, J.

    2008-01-01

    Proton-rich material in a state of nuclear statistical equilibrium (NSE) is one of the least studied regimes of nucleosynthesis. One reason for this is that after hydrogen burning, stellar evolution proceeds at conditions of an equal number of neutrons and protons or at a slight degree of neutron-richness. Proton-rich nucleosynthesis in stars tends to occur only when hydrogen-rich material that accretes onto a white dwarf or a neutron star explodes, or when neutrino interactions in the winds from a nascent proto-neutron star or collapsar disk drive the matter proton-rich prior to or during the nucleosynthesis. In this Letter we solve the NSE equations for a range of proton-rich thermodynamic conditions. We show that cold proton-rich NSE is qualitatively different from neutron-rich NSE. Instead of being dominated by the Fe-peak nuclei with the largest binding energy per nucleon that have a proton-to-nucleon ratio close to the prescribed electron fraction, NSE for proton-rich material near freezeout temperature is mainly composed of 56Ni and free protons. Previous results of nuclear reaction network calculations rely on this nonintuitive high-proton abundance, which this Letter explains. We show how the differences and especially the large fraction of free protons arises from the minimization of the free energy as a result of a delicate competition between the entropy and nuclear binding energy.

  9. Packaging Attributes of Antioxidant-Rich Instant Coffee and Their Influence on the Purchase Intent

    Directory of Open Access Journals (Sweden)

    Marinês P. Corso

    2015-10-01

    Full Text Available The present study aimed to identify the most important packaging attributes for purchasing a product not currently on the Brazilian market: antioxidant-rich instant coffee, a blend of roasted coffee and green coffee. Five package types of the same brand of instant antioxidant-rich coffee marketed in different countries were evaluated through a focus group. The attributes’ glass shape, glass lid color and label, information and brand were selected for the quantitative study. The purchase intent for the packaging images was evaluated with conjoint analysis. In general, an increased purchase intent was verified for more modern packages and browner labels that indicated roasted coffee. The consumers preferred the image of green and roasted coffee beans next to the cup of coffee and valued information about the product’s differentiation (the origin, type, quantity and functions of antioxidants that was presented in the form of explanatory charts on the back of the packaging.

  10. Image Retargeting by Content-Aware Synthesis

    OpenAIRE

    Dong, Weiming; Wu, Fuzhang; Kong, Yan; Mei, Xing; Lee, Tong-Yee; Zhang, Xiaopeng

    2014-01-01

    Real-world images usually contain vivid contents and rich textural details, which will complicate the manipulation on them. In this paper, we design a new framework based on content-aware synthesis to enhance content-aware image retargeting. By detecting the textural regions in an image, the textural image content can be synthesized rather than simply distorted or cropped. This method enables the manipulation of textural & non-textural regions with different strategy since they have different...

  11. Strategy for Comprehensive Profiling and Identification of Acidic Glycosphingolipids Using Ultra-High-Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry.

    Science.gov (United States)

    Hu, Ting; Jia, Zhixin; Zhang, Jin-Lan

    2017-07-18

    Acidic glycosphingolipids (AGSLs), which mainly consist of ganglioside and sulfatide moieties, are highly concentrated in the central nervous system. Comprehensive profiling of AGSLs has historically been challenging because of their high complexity and the lack of standards. In this study, a novel strategy was developed to comprehensively profile AGSLs using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Ganglioside isomers with different glycan chains such as GD1a/GD1b were completely separated on a C18 column for the first time to our knowledge, facilitated by the addition of formic acid in the mobile phase. A mathematical model was established to predict the retention times (RTs) of all theoretically possible AGSLs on the basis of the good logarithmic relationship between the ceramide carbon numbers of the AGSLs in the reference material and their RTs. A data set was created of 571 theoretically possible AGSLs, including the ceramide carbon numbers, RTs, and high-resolution quasi-molecular ions. A novel fast identification strategy was established for global AGSL profiling by comparing the high-resolution quasi-molecular ions and RTs of the tested peaks to those in the data set of 571 AGSLs. Using this strategy, 199 AGSL candidates were identified in rat brain tissue. MS/MS fragments were further collected for these 199 candidates to confirm their identity as AGSLs. This novel strategy was employed to profile AGSLs in brain tissue samples from control rats and model rats with bilateral common carotid artery (2-VO) cerebral ischemia. Forty AGSLs were significantly different between the control and model groups, and these differences were further interpreted.

  12. Inferring species richness and turnover by statistical multiresolution texture analysis of satellite imagery.

    Directory of Open Access Journals (Sweden)

    Matteo Convertino

    Full Text Available BACKGROUND: The quantification of species-richness and species-turnover is essential to effective monitoring of ecosystems. Wetland ecosystems are particularly in need of such monitoring due to their sensitivity to rainfall, water management and other external factors that affect hydrology, soil, and species patterns. A key challenge for environmental scientists is determining the linkage between natural and human stressors, and the effect of that linkage at the species level in space and time. We propose pixel intensity based Shannon entropy for estimating species-richness, and introduce a method based on statistical wavelet multiresolution texture analysis to quantitatively assess interseasonal and interannual species turnover. METHODOLOGY/PRINCIPAL FINDINGS: We model satellite images of regions of interest as textures. We define a texture in an image as a spatial domain where the variations in pixel intensity across the image are both stochastic and multiscale. To compare two textures quantitatively, we first obtain a multiresolution wavelet decomposition of each. Either an appropriate probability density function (pdf model for the coefficients at each subband is selected, and its parameters estimated, or, a non-parametric approach using histograms is adopted. We choose the former, where the wavelet coefficients of the multiresolution decomposition at each subband are modeled as samples from the generalized Gaussian pdf. We then obtain the joint pdf for the coefficients for all subbands, assuming independence across subbands; an approximation that simplifies the computational burden significantly without sacrificing the ability to statistically distinguish textures. We measure the difference between two textures' representative pdf's via the Kullback-Leibler divergence (KL. Species turnover, or [Formula: see text] diversity, is estimated using both this KL divergence and the difference in Shannon entropy. Additionally, we predict species

  13. Platelet-rich plasma in otolaryngology.

    Science.gov (United States)

    Stavrakas, M; Karkos, P D; Markou, K; Grigoriadis, N

    2016-12-01

    Platelet-rich plasma is a novel material that is being used more frequently in many surgical specialties. A literature review on the current and potential uses of platelet-rich plasma in otolaryngology was performed. There is limited evidence on the use of platelet-rich plasma in otolaryngology compared with other specialties: only 11 studies on various subspecialties (otology, rhinology and laryngology) were included in the final review. Based on the limited number of studies, we cannot draw safe conclusions about the value of platelet-rich plasma in otolaryngology. Nevertheless, the available literature suggests that platelet-rich plasma holds promise for future research and may have a number of clinical applications.

  14. The LHCb RICH PMTs Readout Electronics and the Monitoring of the HPDs Quantum Efficiency

    CERN Document Server

    Villa, Marco; Matteuzzi, Clara; D'Ambrosio, Carmelo; Pessina, Gianluigi

    2007-01-01

    LHCb is one of the four main experiments under construction on the Large Hadron Collider at CERN. Its purpose is to study CP violation in B mesons and to look for new physics effects in rare decays of b-hadrons. Particle identification will be essential to enhance the signal/background ratio in the selection of physics channels. For this reason, the Ring Imaging Cherenkov technique has been implemented: two RICH detectors (RICH1 and RICH2) have been designed to cover the wide momentum range 1-150 GeV/c. The produced Cherenkov photons will be focused on two planes of Hybrid PhotoDetectors (HPDs), which are sensitive to external magnetic fields and then need to be shielded. Despite the shielding, however, there will be some fringe field inside the HPDs volume and so it is necessary to experimentally check what is the behaviour of each photodetector when the LHCb dipole magnet is on and the HPDs are illuminated by test patterns. In RICH2, two LED projectors based on the Digital Light Processing technology are ex...

  15. Synthesis and Evaluation of Tricarbonyl 99mTc-Labeled 2-(4-Chlorophenyl-imidazo[1,2-a]pyridine Analogs as Novel SPECT Imaging Radiotracer for TSPO-Rich Cancer

    Directory of Open Access Journals (Sweden)

    Ji Young Choi

    2016-07-01

    Full Text Available The 18-kDa translocator protein (TSPO levels are associated with brain, breast, and prostate cancer progression and have emerged as viable targets for cancer therapy and imaging. In order to develop highly selective and active ligands with a high affinity for TSPO, imidazopyridine-based TSPO ligand (CB256, 3 was prepared as the precursor. 99mTc- and Re-CB256 (1 and 2, respectively were synthesized in high radiochemical yield (74.5% ± 6.4%, decay-corrected, n = 5 and chemical yield (65.6% by the incorporation of the [99mTc(CO3(H2O3]+ and (NEt42[Re(CO3Br3] followed by HPLC separation. Radio-ligand 1 was shown to be stable (>99% when incubated in human serum for 4 h at 37 °C with a relatively low lipophilicity (logD = 2.15 ± 0.02. The rhenium-185 and -187 complex 2 exhibited a moderate affinity (Ki = 159.3 ± 8.7 nM for TSPO, whereas its cytotoxicity evaluated on TSPO-rich tumor cell lines was lower than that observed for the precursor. In vitro uptake studies of 1 in C6 and U87-MG cells for 60 min was found to be 9.84% ± 0.17% and 7.87% ± 0.23% ID, respectively. Our results indicated that 99mTc-CB256 can be considered as a potential new TSPO-rich cancer SPECT imaging agent and provides the foundation for further in vivo evaluation.

  16. Optical telescopes for COMPASS RICH1 up-grade

    CERN Document Server

    Sulc, M; Alekseev, M; Angerer, H; Appolonio, M; Birsa, R; Bordalo, P; Bradamante, F; Bressan, A; Busso, L; Chiosso, V M; Ciliberti, P; Colantoni, M L; Costa, S; Dibiase, N; Dafni, T; Dalla Torre, S; Diaz, V; Duic, V; Delagnes, E; Deschamps, H; Eyrich, W; Faso, D; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Gerassimov, S; Giorgi, M; Gobbo, B; Hagemann, R; von Harrach, D; Heinsius, F H; Joosten, R; Ketzer, B; Königsmann, K; Kolosov, V N; Konorov, I; Kramer, D; Kunne, F; Levorato, S; Maggiora, A; Magnon, A; Mann, A; Martin, A; Menon, G; Mutter, A; Nähle, O; Neyret, D; Nerling, F; Pagano, P; Paul, S; Panebianco, S; Panzieri, D; Pesaro, G; Pizzolotto, C; Polak, J; Rebourgeard, P; Rocco, E; Robinet, F; Schiavon, P; Schill, C; Schoenmeier, P; Silva, L; Slunecka, M; Steiger, L; Sozzi, F; Svec, M; Tessarotto, F; Teufel, A; Wollny, H

    2006-01-01

    The central photon detection area of the Ring Imaging Cherenkov detector at COMPASS, a particle physics experiment at CERN SPS dedicated to hadron physics, has been upgraded from the previous system formed by wire chambers with CsI layers to a very fast UV extended multi anode photo multiplier tube array (MAPMT), including 576 tubes. The active area covered by the MAPMTs is 7.3 times smaller than the one previously equipped with CsI photocathodes, so 576 optical concentrators transforming the image from the old system focal plane to the new photocathode plane were needed. The telescope system formed by two fused silica lenses was designed, produced and assembled. The first prismatic plano-convex field lens is placed in the focal plane of the RICH mirrors. The second condenser lens is off centered and tilted and has one aspherical surface. All lenses have antireflection coating.

  17. Generation of stable lipid raft microdomains in the enterocyte brush border by selective endocytic removal of non-raft membrane.

    Directory of Open Access Journals (Sweden)

    E Michael Danielsen

    Full Text Available The small intestinal brush border has an unusually high proportion of glycolipids which promote the formation of lipid raft microdomains, stabilized by various cross-linking lectins. This unique membrane organization acts to provide physical and chemical stability to the membrane that faces multiple deleterious agents present in the gut lumen, such as bile salts, digestive enzymes of the pancreas, and a plethora of pathogens. In the present work, we studied the constitutive endocytosis from the brush border of cultured jejunal explants of the pig, and the results indicate that this process functions to enrich the contents of lipid raft components in the brush border. The lipophilic fluorescent marker FM, taken up into early endosomes in the terminal web region (TWEEs, was absent from detergent resistant membranes (DRMs, implying an association with non-raft membrane. Furthermore, neither major lipid raft-associated brush border enzymes nor glycolipids were detected by immunofluorescence microscopy in subapical punctae resembling TWEEs. Finally, two model raft lipids, BODIPY-lactosylceramide and BODIPY-GM1, were not endocytosed except when cholera toxin subunit B (CTB was present. In conclusion, we propose that constitutive, selective endocytic removal of non-raft membrane acts as a sorting mechanism to enrich the brush border contents of lipid raft components, such as glycolipids and the major digestive enzymes. This sorting may be energetically driven by changes in membrane curvature when molecules move from a microvillar surface to an endocytic invagination.

  18. Generation of stable lipid raft microdomains in the enterocyte brush border by selective endocytic removal of non-raft membrane.

    Science.gov (United States)

    Danielsen, E Michael; Hansen, Gert H

    2013-01-01

    The small intestinal brush border has an unusually high proportion of glycolipids which promote the formation of lipid raft microdomains, stabilized by various cross-linking lectins. This unique membrane organization acts to provide physical and chemical stability to the membrane that faces multiple deleterious agents present in the gut lumen, such as bile salts, digestive enzymes of the pancreas, and a plethora of pathogens. In the present work, we studied the constitutive endocytosis from the brush border of cultured jejunal explants of the pig, and the results indicate that this process functions to enrich the contents of lipid raft components in the brush border. The lipophilic fluorescent marker FM, taken up into early endosomes in the terminal web region (TWEEs), was absent from detergent resistant membranes (DRMs), implying an association with non-raft membrane. Furthermore, neither major lipid raft-associated brush border enzymes nor glycolipids were detected by immunofluorescence microscopy in subapical punctae resembling TWEEs. Finally, two model raft lipids, BODIPY-lactosylceramide and BODIPY-GM1, were not endocytosed except when cholera toxin subunit B (CTB) was present. In conclusion, we propose that constitutive, selective endocytic removal of non-raft membrane acts as a sorting mechanism to enrich the brush border contents of lipid raft components, such as glycolipids and the major digestive enzymes. This sorting may be energetically driven by changes in membrane curvature when molecules move from a microvillar surface to an endocytic invagination.

  19. Clathrin- and Caveolin-Independent Entry of Human Papillomavirus Type 16—Involvement of Tetraspanin-Enriched Microdomains (TEMs)

    Science.gov (United States)

    Spoden, Gilles; Freitag, Kirsten; Husmann, Matthias; Boller, Klaus; Sapp, Martin; Lambert, Carsten; Florin, Luise

    2008-01-01

    Background Infectious entry of human papillomaviruses into their host cells is an important step in the viral life cycle. For cell binding these viruses use proteoglycans as initial attachment sites. Subsequent transfer to a secondary receptor molecule seems to be involved in virus uptake. Depending on the papillomavirus subtype, it has been reported that entry occurs by clathrin- or caveolin-mediated mechanisms. Regarding human papillomavirus type 16 (HPV16), the primary etiologic agent for development of cervical cancer, clathrin-mediated endocytosis was described as infectious entry pathway. Methodology/Principal Findings Using immunofluorescence and infection studies we show in contrast to published data that infectious entry of HPV16 occurs in a clathrin- and caveolin-independent manner. Inhibition of clathrin- and caveolin/raft-dependent endocytic pathways by dominant-negative mutants and siRNA-mediated knockdown, as well as inhibition of dynamin function, did not impair infection. Rather, we provide evidence for involvement of tetraspanin-enriched microdomains (TEMs) in HPV16 endocytosis. Following cell attachment, HPV16 particles colocalized with the tetraspanins CD63 and CD151 on the cell surface. Notably, tetraspanin-specific antibodies and siRNA inhibited HPV16 cell entry and infection, confirming the importance of TEMs for infectious endocytosis of HPV16. Conclusions/Significance Tetraspanins fulfill various roles in the life cycle of a number of important viral pathogens, including human immunodeficiency virus (HIV) and hepatitis C virus (HCV). However, their involvement in endocytosis of viral particles has not been proven. Our data indicate TEMs as a novel clathrin- and caveolin-independent invasion route for viral pathogens and especially HPV16. PMID:18836553

  20. My career as an immunoglycobiologist.

    Science.gov (United States)

    Marcus, Donald M

    2013-01-01

    The research program of my laboratory included three major topics: the structures and immunology of human carbohydrate blood group and glycosphingolipid antigens; the tissue distribution, subcellular localization and biosynthesis of glycosphingolipids; and the structural basis of the binding of carbohydrates by antibodies and lectins.

  1. Circumstellar ammonia in oxygen-rich evolved stars

    Science.gov (United States)

    Wong, K. T.; Menten, K. M.; Kamiński, T.; Wyrowski, F.; Lacy, J. H.; Greathouse, T. K.

    2018-04-01

    Context. The circumstellar ammonia (NH3) chemistry in evolved stars is poorly understood. Previous observations and modelling showed that NH3 abundance in oxygen-rich stars is several orders of magnitude above that predicted by equilibrium chemistry. Aims: We would like to characterise the spatial distribution and excitation of NH3 in the oxygen-rich circumstellar envelopes (CSEs) of four diverse targets: IK Tau, VY CMa, OH 231.8+4.2, and IRC +10420. Methods: We observed NH3 emission from the ground state in the inversion transitions near 1.3 cm with the Very Large Array (VLA) and submillimetre rotational transitions with the Heterodyne Instrument for the Far-Infrared (HIFI) aboard Herschel Space Observatory from all four targets. For IK Tau and VY CMa, we observed NH3 rovibrational absorption lines in the ν2 band near 10.5 μm with the Texas Echelon Cross Echelle Spectrograph (TEXES) at the NASA Infrared Telescope Facility (IRTF). We also attempted to search for the rotational transition within the excited vibrational state (v2 = 1) near 2 mm with the IRAM 30m Telescope. Non-LTE radiative transfer modelling, including radiative pumping to the vibrational state, was carried out to derive the radial distribution of NH3 in the CSEs of these targets. Results: We detected NH3 inversion and rotational emission in all four targets. IK Tau and VY CMa show blueshifted absorption in the rovibrational spectra. We did not detect vibrationally excited rotational transition from IK Tau. Spatially resolved VLA images of IK Tau and IRC +10420 show clumpy emission structures; unresolved images of VY CMa and OH 231.8+4.2 indicate that the spatial-kinematic distribution of NH3 is similar to that of assorted molecules, such as SO and SO2, that exhibit localised and clumpy emission. Our modelling shows that the NH3 abundance relative to molecular hydrogen is generally of the order of 10-7, which is a few times lower than previous estimates that were made without considering radiative

  2. Dynamic complexity: plant receptor complexes at the plasma membrane.

    Science.gov (United States)

    Burkart, Rebecca C; Stahl, Yvonne

    2017-12-01

    Plant receptor complexes at the cell surface perceive many different external and internal signalling molecules and relay these signals into the cell to regulate development, growth and immunity. Recent progress in the analyses of receptor complexes using different live cell imaging approaches have shown that receptor complex formation and composition are dynamic and take place at specific microdomains at the plasma membrane. In this review we focus on three prominent examples of Arabidopsis thaliana receptor complexes and how their dynamic spatio-temporal distribution at the PM has been studied recently. We will elaborate on the newly emerging concept of plasma membrane microdomains as potential hubs for specific receptor complex assembly and signalling outputs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Black manganese-rich crusts on a Gothic cathedral

    Science.gov (United States)

    Macholdt, Dorothea S.; Herrmann, Siegfried; Jochum, Klaus Peter; Kilcoyne, A. L. David; Laubscher, Thomas; Pfisterer, Jonas H. K.; Pöhlker, Christopher; Schwager, Beate; Weber, Bettina; Weigand, Markus; Domke, Katrin F.; Andreae, Meinrat O.

    2017-12-01

    Black manganese-rich crusts are found worldwide on the façades of historical buildings. In this study, they were studied exemplarily on the façade of the Freiburger Münster (Freiburg Minster), Germany, and measured in-situ by portable X-ray fluorescence (XRF). The XRF was calibrated to allow the conversion from apparent mass fractions to Mn surface density (Mn mass per area), to compensate for the fact that portable XRF mass fraction measurements from thin layers violate the assumption of a homogeneous measurement volume. Additionally, 200-nm femtosecond laser ablation-inductively coupled plasma-mass spectrometry (fs LA-ICP-MS) measurements, scanning transmission X-ray microscopy-near edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS), Raman spectroscopy, and imaging by light microscopy were conducted to obtain further insight into the crust material, such as potential biogenic contributions, element distributions, trace element compositions, and organic functional groups. While black crusts of various types are present at many places on the minster's facade, crusts rich in Mn (with a Mn surface density >150 μg cm-2) are restricted to a maximum height of about 7 m. The only exceptions are those developed on the Renaissance-Vorhalle (Renaissance Portico) at a height of about 8 m. This part of the façade had been cleaned and treated with a silicon resin as recently as 2003. These crusts thus accumulated over a period of only 12 years. Yet, they are exceptionally Mn-rich with a surface density of 1200 μg cm-2, and therefore require an accumulation rate of about 100 μg cm-2 Mn per year. Trace element analyses support the theory that vehicle emissions are responsible for most of the Mn supply. Lead, barium, and zinc correlate with manganese, indicating that tire material, brake pads, and resuspended road dust are likely to be the element sources. Microscopic investigations show no organisms on or in the Mn-rich crusts. In contrast, Mn-free black

  4. Insights into Collisional between Small Bodies: Comparison of Impacted Magnesium-rich Minerals

    Science.gov (United States)

    Lederer, Susan M.; Jensen, E. A.; Strojia, C.; Smith, D. C.; Keller, L. P.; Nakamura-Messenger, K.; Berger, E. L.; Lindsay, S. S.; Wooden, D. H.; Cintala, M. J.; hide

    2013-01-01

    Impacts are sustained by comets and asteroids throughout their lives, especially early in the Solar system's history, as described by the Nice model. Identifying observable properties that may be altered due to impacts can lead to a better understanding their collisional histories. Here, we investigate spectral effects and physical shock features observed in infrared spectra and Transmission Electron Microscope (TEM) images, respectively, of magnesium-rich minerals subjected to shock through impact experiments. Samples of magnesium-rich forsterite (Mg2SiO4, olivine), orthoenstatite (Mg2SiO3, pyroxene), diopside (MgCaSi2O6, monoclinic pyroxene), and magnesite (MgCO3, carbonate) were impacted at speeds of 2.4 km/s, 2.6 km/s and 2.8 km/s. Impact experiments were conducted in the Johnson Space Center Experimental Impact Laboratory using the vertical gun. Clear signatures are observed in both the mid-IR spectra (shift in wavelengths of the spectral peaks and relative amplitude changes) of all minerals except magnesite, and in TEM images (planar dislocations) of both the forsterite and orthoenstatite samples. Further discussion on forsterite and enstatite analyses can be found in Jensen et al., this meeting.

  5. An iterative method for the analysis of Cherenkov rings in the HERA-B RICH

    International Nuclear Information System (INIS)

    Staric, M.; Krizan, P.

    1999-01-01

    A new method is presented for the analysis of data recorded with a Ring Imaging Cherenkov (RICH) counter. The method, an iterative sorting of hits on the photon detector, is particularly useful for events where rings overlap considerably. The algorithm was tested on simulated data for the HERA-B experiment

  6. An Improved Cluster Richness Estimator

    Energy Technology Data Exchange (ETDEWEB)

    Rozo, Eduardo; /Ohio State U.; Rykoff, Eli S.; /UC, Santa Barbara; Koester, Benjamin P.; /Chicago U. /KICP, Chicago; McKay, Timothy; /Michigan U.; Hao, Jiangang; /Michigan U.; Evrard, August; /Michigan U.; Wechsler, Risa H.; /SLAC; Hansen, Sarah; /Chicago U. /KICP, Chicago; Sheldon, Erin; /New York U.; Johnston, David; /Houston U.; Becker, Matthew R.; /Chicago U. /KICP, Chicago; Annis, James T.; /Fermilab; Bleem, Lindsey; /Chicago U.; Scranton, Ryan; /Pittsburgh U.

    2009-08-03

    Minimizing the scatter between cluster mass and accessible observables is an important goal for cluster cosmology. In this work, we introduce a new matched filter richness estimator, and test its performance using the maxBCG cluster catalog. Our new estimator significantly reduces the variance in the L{sub X}-richness relation, from {sigma}{sub lnL{sub X}}{sup 2} = (0.86 {+-} 0.02){sup 2} to {sigma}{sub lnL{sub X}}{sup 2} = (0.69 {+-} 0.02){sup 2}. Relative to the maxBCG richness estimate, it also removes the strong redshift dependence of the richness scaling relations, and is significantly more robust to photometric and redshift errors. These improvements are largely due to our more sophisticated treatment of galaxy color data. We also demonstrate the scatter in the L{sub X}-richness relation depends on the aperture used to estimate cluster richness, and introduce a novel approach for optimizing said aperture which can be easily generalized to other mass tracers.

  7. LHCb RICH Upgrade: an overview of the photon detector and electronics system

    CERN Document Server

    Cassina, L

    2016-01-01

    The LHCb experiment is one of the four large detectors operating at the LHC at CERN and it is mainly devoted to CP violation measurements and to the search for new physics in rare decays of beauty and charm hadrons. The data from the two Ring Image Cherenkov (RICH-1 and RICH-2) detectors are essential to identify particles in a wide momentum range. From 2019 onwards 14 TeV collisions with luminosities reaching up to $2\\cdot10^{33}$ cm$^{-2}$ s$^{-1}$ with 25 ns bunch spacing are planned, with the goal of collecting 5 fb$^{-1}$ of data per year. In order to avoid degradation of the PID performance at such high rate (40 MHz), the RICH detector has to be upgraded. New photodetectors (Multi-anode photomultiplier tubes, MaPMTs) have been chosen and will be read out using a 8-channels chip, named CLARO, designed to sustain a photon counting rate up to 40 MHz, while minimizing the power consumption and the cross-talk. A 128-bit digital register allows selection of thresholds and attenuation values and provides featu...

  8. Get rich quick: the signal to respond procedure reveals the time course of semantic richness effects during visual word recognition.

    Science.gov (United States)

    Hargreaves, Ian S; Pexman, Penny M

    2014-05-01

    According to several current frameworks, semantic processing involves an early influence of language-based information followed by later influences of object-based information (e.g., situated simulations; Santos, Chaigneau, Simmons, & Barsalou, 2011). In the present study we examined whether these predictions extend to the influence of semantic variables in visual word recognition. We investigated the time course of semantic richness effects in visual word recognition using a signal-to-respond (STR) paradigm fitted to a lexical decision (LDT) and a semantic categorization (SCT) task. We used linear mixed effects to examine the relative contributions of language-based (number of senses, ARC) and object-based (imageability, number of features, body-object interaction ratings) descriptions of semantic richness at four STR durations (75, 100, 200, and 400ms). Results showed an early influence of number of senses and ARC in the SCT. In both LDT and SCT, object-based effects were the last to influence participants' decision latencies. We interpret our results within a framework in which semantic processes are available to influence word recognition as a function of their availability over time, and of their relevance to task-specific demands. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Joint Probability Models of Radiology Images and Clinical Annotations

    Science.gov (United States)

    Arnold, Corey Wells

    2009-01-01

    Radiology data, in the form of images and reports, is growing at a high rate due to the introduction of new imaging modalities, new uses of existing modalities, and the growing importance of objective image information in the diagnosis and treatment of patients. This increase has resulted in an enormous set of image data that is richly annotated…

  10. LHCB RICH gas system proposal

    CERN Document Server

    Bosteels, Michel; Haider, S

    2001-01-01

    Both LHCb RICH will be operated with fluorocarbon as gas radiator. RICH 1 will be filled with 4m^3 of C4F10 and RICH 2 with 100m^3 of CF4. The gas systems will run as a closed loop circulation and a gas recovery system within the closed loop is planned for RICH 1, where the recovery of the CF4 will only be realised during filling and emptying of the detector. Inline gas purification is foreseen for the gas systems in order to limit water and oxygen impurities.

  11. Four dimensional X-ray imaging of deformation modes in organic-rich Green River Shale retorted under uniaxial compression

    Science.gov (United States)

    Kobchenko, M.; Pluymakers, A.; Cordonnier, B.; Tairova, A.; Renard, F.

    2017-12-01

    Time-lapse imaging of fracture network development in organic-rich shales at elevated temperatures while kerogen is retorted allows characterizing the development of microfractures and the onset of primary migration. When the solid organic matter is transformed to hydrocarbons with lower molecular weight, the local pore-pressure increases and drives the propagation of hydro-fractures sub-parallel to the shale lamination. On the scale of samples of several mm size, these fractures can be described as mode I opening, where fracture walls dilate in the direction of minimal compression. However, so far experiments coupled to microtomography in situ imaging have been performed on samples where no load was imposed. Here, an external load was applied perpendicular to the sample laminations and we show that this stress state slows down, but does not stop, the propagation of fracture along bedding. Conversely, microfractures also propagate sub-perpendicular to the shale lamination, creating a percolating network in three dimensions. To monitor this process we have used a uniaxial compaction rig combined with in-situ heating from 50 to 500 deg C, while capturing three-dimensional X-ray microtomography scans at a voxel resolution of 2.2 μm; Data were acquired at beamline ID19 at the European Synchrotron Radiation Facility. In total ten time-resolved experiments were performed at different vertical loading conditions, with and without lateral passive confinement and different heating rates. At high external load the sample fails by symmetric bulging, while at lower external load the reaction-induced fracture network develops with the presence of microfractures both sub-parallel and sub-perpendicular to the bedding direction. In addition, the variation of experimental conditions allows the decoupling of the effects of the hydrocarbon decomposition reaction on the deformation process from the influence of thermal stress heating on the weakening and failure mode of immature

  12. Synthesis and Evaluation of Tricarbonyl 99mTc-Labeled 2-(4-Chloro)phenyl-imidazo[1,2-a]pyridine Analogs as Novel SPECT Imaging Radiotracer for TSPO-Rich Cancer

    Science.gov (United States)

    Choi, Ji Young; Iacobazzi, Rosa Maria; Perrone, Mara; Margiotta, Nicola; Cutrignelli, Annalisa; Jung, Jae Ho; Park, Do Dam; Moon, Byung Seok; Denora, Nunzio; Kim, Sang Eun; Lee, Byung Chul

    2016-01-01

    The 18-kDa translocator protein (TSPO) levels are associated with brain, breast, and prostate cancer progression and have emerged as viable targets for cancer therapy and imaging. In order to develop highly selective and active ligands with a high affinity for TSPO, imidazopyridine-based TSPO ligand (CB256, 3) was prepared as the precursor. 99mTc- and Re-CB256 (1 and 2, respectively) were synthesized in high radiochemical yield (74.5% ± 6.4%, decay-corrected, n = 5) and chemical yield (65.6%) by the incorporation of the [99mTc(CO)3(H2O)3]+ and (NEt4)2[Re(CO)3Br3] followed by HPLC separation. Radio-ligand 1 was shown to be stable (>99%) when incubated in human serum for 4 h at 37 °C with a relatively low lipophilicity (logD = 2.15 ± 0.02). The rhenium-185 and -187 complex 2 exhibited a moderate affinity (Ki = 159.3 ± 8.7 nM) for TSPO, whereas its cytotoxicity evaluated on TSPO-rich tumor cell lines was lower than that observed for the precursor. In vitro uptake studies of 1 in C6 and U87-MG cells for 60 min was found to be 9.84% ± 0.17% and 7.87% ± 0.23% ID, respectively. Our results indicated that 99mTc-CB256 can be considered as a potential new TSPO-rich cancer SPECT imaging agent and provides the foundation for further in vivo evaluation. PMID:27399688

  13. Detail Enhancement for Infrared Images Based on Propagated Image Filter

    Directory of Open Access Journals (Sweden)

    Yishu Peng

    2016-01-01

    Full Text Available For displaying high-dynamic-range images acquired by thermal camera systems, 14-bit raw infrared data should map into 8-bit gray values. This paper presents a new method for detail enhancement of infrared images to display the image with a relatively satisfied contrast and brightness, rich detail information, and no artifacts caused by the image processing. We first adopt a propagated image filter to smooth the input image and separate the image into the base layer and the detail layer. Then, we refine the base layer by using modified histogram projection for compressing. Meanwhile, the adaptive weights derived from the layer decomposition processing are used as the strict gain control for the detail layer. The final display result is obtained by recombining the two modified layers. Experimental results on both cooled and uncooled infrared data verify that the proposed method outperforms the method based on log-power histogram modification and bilateral filter-based detail enhancement in both detail enhancement and visual effect.

  14. The shedding activity of ADAM17 is sequestered in lipid rafts

    International Nuclear Information System (INIS)

    Tellier, Edwige; Canault, Matthias; Rebsomen, Laure; Bonardo, Bernadette; Juhan-Vague, Irene; Nalbone, Gilles; Peiretti, Franck

    2006-01-01

    The tumor necrosis factor-alpha (TNF) converting enzyme (ADAM17) is a metalloprotease-disintegrin responsible for the cleavage of several biologically active transmembrane proteins. However, the substrate specificity of ADAM17 and the regulation of its shedding activity are still poorly understood. Here, we report that during its transport through the Golgi apparatus, ADAM17 is included in cholesterol-rich membrane microdomains (lipid rafts) where its prodomain is cleaved by furin. Consequently, ADAM17 shedding activity is sequestered in lipid rafts, which is confirmed by the fact that metalloproteinase inhibition increases the proportion of ADAM17 substrates (TNF and its receptors TNFR1 and TNFR2) in lipid rafts. Membrane cholesterol depletion increases the ADAM17-dependent shedding of these substrates demonstrating the importance of lipid rafts in the control of this process. Furthermore, ADAM17 substrates are present in different proportions in lipid rafts, suggesting that the entry of each of these substrates in these particular membrane microdomains is specifically regulated. Our data support the idea that one of the mechanisms regulating ADAM17 substrate cleavage involves protein partitioning in lipid rafts

  15. Conception and design of a control and monitoring system for the mirror alignment of the CBM RICH detector

    Science.gov (United States)

    Bendarouach, J.

    2016-08-01

    The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-proton and Ion Research (FAIR) complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures created in A+A collisions. For the SIS100 accelerator, the foreseen beam energy will range up to 11 AGeV for the heaviest nuclei. One of the key detector components required for the CBM physics program is the Ring Imaging CHerenkov (RICH) detector, which is developed for efficient and clean electron identification and pion suppression. An important aspect to guarantee a stable operation of the RICH detector is the alignment of the mirrors. A qualitative alignment control procedure for the mirror system has been implemented in the CBM RICH prototype detector and tested under real conditions at the CERN PS/T9 beamline. Collected data and results of image processing are reviewed and discussed. In parallel a quantitative method using recorded data has also been employed to compute mirror displacements of the RICH mirrors. Results based on simulated events and the limits of the method are presented and discussed as well. If mirror misalignment is detected, it can be subsequently included and rectified by correction routines. A first correction routine is presented and a comparison between misaligned, corrected and ideal geometries is shown.

  16. Conception and design of a control and monitoring system for the mirror alignment of the CBM RICH detector

    International Nuclear Information System (INIS)

    Bendarouach, J

    2016-01-01

    The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-proton and Ion Research (FAIR) complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures created in A+A collisions. For the SIS100 accelerator, the foreseen beam energy will range up to 11 AGeV for the heaviest nuclei. One of the key detector components required for the CBM physics program is the Ring Imaging CHerenkov (RICH) detector, which is developed for efficient and clean electron identification and pion suppression. An important aspect to guarantee a stable operation of the RICH detector is the alignment of the mirrors. A qualitative alignment control procedure for the mirror system has been implemented in the CBM RICH prototype detector and tested under real conditions at the CERN PS/T9 beamline. Collected data and results of image processing are reviewed and discussed. In parallel a quantitative method using recorded data has also been employed to compute mirror displacements of the RICH mirrors. Results based on simulated events and the limits of the method are presented and discussed as well. If mirror misalignment is detected, it can be subsequently included and rectified by correction routines. A first correction routine is presented and a comparison between misaligned, corrected and ideal geometries is shown. (paper)

  17. The HADES-RICH upgrade using Hamamatsu H12700 MAPMTs with DiRICH FEE + Readout

    Science.gov (United States)

    Patel, V.; Traxler, M.

    2018-03-01

    The High Acceptance Di-Electron Spectrometer (HADES) is operational since the year 2000 and uses a hadron blind RICH detector for electron identification. The RICH photon detector is currently replaced by Hamamatsu H12700 MAPMTs with a readout system based on the DiRICH front-end module. The electronic readout chain is being developed as a joint effort of the HADES-, CBM- and PANDA collaborations and will also be used in the photon detectors for the upcoming Compressed Baryonic Matter (CBM) and PANDA experiments at FAIR . This article gives a brief overview on the photomultipliers and their quality assurance test measurements, as well as first measurements of the new DiRICH front-end module in final configurations.

  18. GTC/CanariCam Mid-IR Imaging of the Fullerene-rich Planetary Nebula IC 418: Searching for the Spatial Distribution of Fullerene-like Molecules

    Science.gov (United States)

    Díaz-Luis, J. J.; García-Hernández, D. A.; Manchado, A.; García-Lario, P.; Villaver, E.; García-Segura, G.

    2018-03-01

    We present seeing-limited narrow-band mid-IR GTC/CanariCam images of the spatially extended fullerene-containing planetary nebula (PN) IC 418. The narrow-band images cover the C60 fullerene band at 17.4 μm, the polycyclic aromatic hydrocarbon like (PAH-like) feature at 11.3 μm, the broad 9–13 μm feature, and their adjacent continua at 9.8 and 20.5 μm. We study the relative spatial distribution of these complex species, all detected in the Spitzer and Infrared Space Observatory spectra of IC 418, with the aim of getting observational constraints to the formation process of fullerenes in H-rich circumstellar environments. A similar ring-like extended structure is seen in all narrow-band filters, except in the dust continuum emission at 9.8 μm, which peaks closer to the central star. The continuum-subtracted images display a clear ring-like extended structure for the carrier of the broad 9–13 μm emission, while the spatial distribution of the (PAH-like) 11.3 μm emission is not so well defined. Interestingly, a residual C60 17.4 μm emission (at about 4σ from the sky background) is seen when subtracting the dust continuum emission at 20.5 μm. This residual C60 emission, if real, might have several interpretations, the most exciting being perhaps that other fullerene-based species like hydrogenated fullerenes with very low H-content may contribute to the observed 17.4 μm emission. We conclude that higher sensitivity mid-IR images and spatially resolved spectroscopic observations (especially in the Q-band) are necessary to get some clues about fullerene formation in PNe.

  19. Conception and design of a control and monitoring system for the mirror alignment of the CBM RICH detector

    Science.gov (United States)

    Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H.; Belogurov, S.; Bendarouach, J.; Boldyreva, N.; Deveaux, C.; Dobyrn, V.; Dürr, M.; Eschke, J.; Förtsch, J.; Heep, J.; Höhne, C.; Kampert, K.-H.; Kochenda, L.; Kopfer, J.; Kravtsov, P.; Kres, I.; Lebedev, S.; Lebedeva, E.; Leonova, E.; Linev, S.; Mahmoud, T.; Michel, J.; Miftakhov, N.; Niebur, W.; Ovcharenko, E.; Patel, V.; Pauly, C.; Pfeifer, D.; Querchfeld, S.; Rautenberg, J.; Reinecke, S.; Riabov, Y.; Roshchin, E.; Samsonov, V.; Schetinin, V.; Tarasenkova, O.; Traxler, M.; Ugur, C.; Vznuzdaev, E.; Vznuzdaev, M.

    2017-12-01

    The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-proton and Ion Research (FAIR) will investigate the phase diagram of strongly interacting matter at high net-baryon density and moderate temperature in A+A collisions. One of the key detectors of CBM to explore this physics program is a Ring Imaging CHerenkov (RICH) detector for electron identification. For a high performance of the RICH detector precise mirror alignment is essential. A three-step correction cycle has been developed, which will be discussed: First a qualitative, fast check of the mirror positions, second a quantitative determination of possible misalignments and third a software correction routine, allowing a proper functioning of the RICH under misalignment conditions.

  20. Intratendon Delivery of Leukocyte-Poor Platelet-Rich Plasma Improves Healing Compared With Leukocyte-Rich Platelet-Rich Plasma in a Rabbit Achilles Tendinopathy Model.

    Science.gov (United States)

    Yan, Ruijian; Gu, Yanjia; Ran, Jisheng; Hu, Yejun; Zheng, Zefeng; Zeng, Mengfeng; Heng, Boon Chin; Chen, Xiao; Yin, Zi; Chen, Weishan; Shen, Weiliang; Ouyang, Hongwei

    2017-07-01

    Chronic tendinopathy is a commonly occurring clinical problem that affects both athletes and inactive middle-aged patients. Although some studies have shown that different platelet-rich plasma (PRP) preparations could exert various therapeutic effects in vitro, the role of leukocytes in PRP has not yet been defined under tendinopathy conditions in vivo. This study compared the effects of the intratendon delivery of leukocyte-poor PRP (Lp-PRP) versus leukocyte-rich PRP (Lr-PRP) in a rabbit chronic tendinopathy model in vivo. Controlled laboratory study. Four weeks after a local injection of collagenase in the Achilles tendon, the following treatments were randomly administered on the lesions: injections of (1) 200 μL of Lp-PRP (n = 8), (2) 200 μL of Lr-PRP (n = 8), or (3) 200 μL of saline (n = 8). Healing outcomes were assessed at 4 weeks after therapy with magnetic resonance imaging (MRI), cytokine quantification, real-time polymerase chain reaction analysis of gene expression, histology, and transmission electron microscopy (TEM). MRI revealed that the Lr-PRP and saline groups displayed higher signal intensities compared with the Lp-PRP group with T2 mapping. Histologically, the Lp-PRP group displayed significantly better general scores compared with the Lr-PRP ( P = .001) and saline ( P tendon healing and is a preferable option for the clinical treatment of tendinopathy. PRP is widely used in the clinical management of chronic tendinopathy. However, the clinical results are ambiguous. It is imperative to understand the influence of leukocytes on PRP-mediated tissue healing in vivo, which could facilitate the better clinical management of chronic tendinopathy. Further studies are needed to translate our findings to the clinical setting.

  1. ACCRETION AND PRESERVATION OF D-RICH ORGANIC PARTICLES IN CARBONACEOUS CHONDRITES: EVIDENCE FOR IMPORTANT TRANSPORT IN THE EARLY SOLAR SYSTEM NEBULA

    International Nuclear Information System (INIS)

    Remusat, L.; Guan, Y.; Wang, Y.; Eiler, J. M.

    2010-01-01

    We have acquired NanoSIMS images of the matrices of CI, CM, and CR carbonaceous chondrites to study, in situ, the organic matter trapped during the formation of their parent bodies. D/H ratio images reveal the occurrence of D-rich hot spots, constituting isolated organic particles. Not all the organic particles are D-rich hot spots, indicating that at least two kinds of organic particles have been accreted in the parent bodies. Ratio profiles through D-rich hot spots indicate that no significant self-diffusion of deuterium occurs between the D-rich organic matter and the depleted hydrous minerals that are surrounding them. This is not the result of a physical shielding by any constituent of the chondrites. Ab initio calculations indicate that it cannot be explained by isotopic equilibrium. Then it appears that the organic matter that is extremely enriched in D does not exchange with the hydrous minerals, or this exchange is so slow that it is not significant over the 4.5 billion year history on the parent body. If we consider that the D-rich hot spots are the result of an exposure to intense irradiation, then it appears that carbonaceous chondrites accreted organic particles that have been brought to different regions of the solar nebula. This is likely the result of important radial and vertical transport in the early solar system.

  2. Association of 3He-rich solar energetic particles with large-scale coronal waves

    Science.gov (United States)

    Bucik, Radoslav; Innes, Davina; Guo, Lijia; Mason, Glenn M.; Wiedenbeck, Mark

    2016-07-01

    Impulsive or 3He-rich solar energetic particle (SEP) events have been typically associated with jets or small EUV brightenings. We identify 30 impulsive SEP events from ACE at L1 during the solar minimum period 2007-2010 and examine their solar sources with high resolution STEREO-A EUV images. At beginning of 2007, STEREO-A was near the Earth while at the end of the investigated period, when there were more events, STEREO-A was leading the Earth by 90°. Thus STEREO-A provided a better (more direct) view on 3He-rich flares generally located on the western Sun's hemisphere. Surprisingly, we find that about half of the events are associated with large-scale EUV coronal waves. This finding provides new insights on acceleration and transport of 3He-rich SEPs in solar corona. It is believed that elemental and isotopic fractionation in impulsive SEP events is caused by more localized processes operating in the flare sites. The EUV waves have been reported in gradual SEP events in association with fast coronal mass ejections. To examine their role on 3He-rich SEPs production the energy spectra and relative abundances are discussed. R. Bucik is supported by the Deutsche Forschungsgemeinschaft under grant BU 3115/2-1.

  3. Fuzzy image processing and applications with Matlab

    CERN Document Server

    Chaira, Tamalika

    2009-01-01

    In contrast to classical image analysis methods that employ ""crisp"" mathematics, fuzzy set techniques provide an elegant foundation and a set of rich methodologies for diverse image-processing tasks. However, a solid understanding of fuzzy processing requires a firm grasp of essential principles and background knowledge.Fuzzy Image Processing and Applications with MATLAB® presents the integral science and essential mathematics behind this exciting and dynamic branch of image processing, which is becoming increasingly important to applications in areas such as remote sensing, medical imaging,

  4. A PUFA-rich diet improves fat oxidation following saturated fat-rich meal.

    Science.gov (United States)

    Stevenson, Jada L; Miller, Mary K; Skillman, Hannah E; Paton, Chad M; Cooper, Jamie A

    2017-08-01

    To determine substrate oxidation responses to saturated fatty acid (SFA)-rich meals before and after a 7-day polyunsaturated fatty acid (PUFA)-rich diet versus control diet. Twenty-six, normal-weight, adults were randomly assigned to either PUFA or control diet. Following a 3-day lead-in diet, participants completed the pre-diet visit where anthropometrics and resting metabolic rate (RMR) were measured, and two SFA-rich HF meals (breakfast and lunch) were consumed. Indirect calorimetry was used to determine fat oxidation (Fox) and energy expenditure (EE) for 4 h after each meal. Participants then consumed a PUFA-rich diet (50 % carbohydrate, 15 % protein, 35 % fat, of which 21 % of total energy was PUFA) or control diet (50 % carbohydrate, 15 % protein, 35 % fat, of which 7 % of total energy was PUFA) for the next 7 days. Following the 7-day diet, participants completed the post-diet visit. From pre- to post-PUFA-rich diet, there was no change in RMR (16.3 ± 0.8 vs. 16.4 ± 0.8 kcal/20 min) or in incremental area under the curve for EE (118.9 ± 20.6-126.9 ± 14.1 kcal/8h, ns). Fasting respiratory exchange ratio increased from pre- to post-PUFA-rich diet only (0.83 ± 0.1-0.86 ± 0.1, p diet (0.03 ± 0.1-0.23 ± 0.1 g/15 min for cumulative Fox; p diet initiates greater fat oxidation after eating occasional high SFA meals compared to a control diet, an effect achieved in 7 days.

  5. Membrane microdomain-associated uroplakin IIIa contributes to Src-dependent mechanisms of anti-apoptotic proliferation in human bladder carcinoma cells

    Directory of Open Access Journals (Sweden)

    Shigeru Kihira

    2012-08-01

    Our previous study demonstrated that tyrosine phosphorylation of p145met/β-subunit of hepatocyte growth factor receptor by epidermal growth factor receptor and Src contributes to the anti-apoptotic growth of human bladder carcinoma cell 5637 under serum-starved conditions. Here, we show that some other cell lines of human bladder carcinoma, but not other types of human cancer cells, also exhibit Src-dependent, anti-apoptotic proliferation under serum-starved conditions, and that low-density, detergent-insoluble membrane microdomains (MD serve as a structural platform for signaling events involving p145met, EGFR, and Src. As an MD-associated molecule that may contribute to bladder carcinoma-specific cellular function, we identified uroplakin IIIa (UPIIIa, an urothelium-specific protein. Results obtained so far revealed: 1 UPIIIa undergoes partial proteolysis in serum-starved cells; 2 a specific antibody to the extracellular domain of UPIIIa inhibits the proteolysis of UPIIIa and the activation of Src, and promotes apoptosis in serum-starved cells; and 3 knockdown of UPIIIa by short interfering RNA also promotes apoptosis in serum-starved cells. GM6001, a potent inhibitor of matrix metalloproteinase (MMP, inhibits the proteolysis of UPIIIa and promotes apoptosis in serum-starved cells. Furthermore, serum starvation promotes expression and secretion of the heparin-binding EGF-like growth factor in a manner that depends on the functions of MMP, Src, and UPIIIa. These results highlight a hitherto unknown signaling network involving a subset of MD-associated molecules in the anti-apoptotic mechanisms of human bladder carcinoma cells.

  6. Test-beam Results from a RICH Detector Prototype Using Aerogel Radiator and Pixel Hybrid Photon Detectors

    CERN Document Server

    Aglieri-Rinella, G; Van Lysebetten, A; Piedigrossi, D; Wyllie, K; Bellunato, T F; Calvi, M; Matteuzzi, C; Musy, M; Perego, D L; Somerville, L P; Newby, C; Easo, S; Wotton, S

    2006-01-01

    A test-beam study was performed at CERN with a Ring Imaging Cherenkov (RICH) prototype using three pixel Hybrid Photon Detectors. Results on the photon yield and Cherenkov angle resolution are presented here, for the Aerogel radiator and also for reference runs taken with Nitrogen radiator.

  7. Kings Today, Rich Tomorrow

    DEFF Research Database (Denmark)

    Fattoum, Asma

    2013-01-01

    This study investigates the King vs. Rich dilemma that founder-CEOs face at IPO. When undertaking IPO, founders face two options. They can either get rich, but then run the risk of losing the control over their firms; or they can remain kings by introducing defensive mechanisms, but this is likel...

  8. Joint imaging in childhood and adolescence

    Energy Technology Data Exchange (ETDEWEB)

    Lopes Viana, Sergio [Hospital da Crianca de Brasilia - Jose Alencar Clinica Vila Rica (Brazil); Machado, Ribeiro, Maria Custodia [Hospital da Crianca de Brasilia - Jose Alencar Hospital de Base do Distrito Federal (Brazil); Beber Machado, Bruno [Clinica Radiologica Med Imagem, Unimed Sul Caprixaba, Santa Casa de Misericordia de Cachoeiro de Itapemirim (Brazil)

    2013-11-01

    First book to be devoted to the imaging of skeletally immature joints since the advent of cross-sectional methods. Covers a wide range of pathologic conditions. Identifies the advantages and weak points of each imaging method. Highlights anatomic and developmental peculiarities of the growing skeleton. Richly illustrated, with up-to-date references and summaries of key points. Since the advent of cross-sectional imaging methods, few works have been devoted to pediatric musculoskeletal imaging, and information is especially limited on the skeletally immature joint. Furthermore, reduced emphasis on pediatric training means that general radiologists are increasingly unfamiliar with normal and abnormal imaging findings in children and adolescents. Knowledge of the imaging appearances of the immature joint is, however, crucial for correct image interpretation. This book covers key selected topics in the imaging evaluation of the skeletally immature joint. The opening chapters consider the current role, advantages, and limitations of each modality in pediatric assessment and present the imaging appearances of anatomic and developmental peculiarities of the growing skeleton. Findings in a wide range of important conditions are then described in a series of richly illustrated chapters that document appearances on diverse imaging studies, from conventional radiography through to modern high-tech modalities. By presenting the essential information on imaging of the immature joint, the authors hope to provide radiologists (musculoskeletal specialists and generalists alike) with a new tool that will assist greatly in overcoming the daily challenges posed by interpretation of pediatric examinations in the twenty-first century. The book will also be of interest to all other specialists involved in the diagnosis and treatment of children and adolescents with articular complaints.

  9. Local structure of Rb2Li4(SeO4)3·2H2O by the modeling of X-ray diffuse scattering — from average-structure to microdomain model

    International Nuclear Information System (INIS)

    Komornicka, Dorota; Wołcyrz, Marek; Pietraszko, Adam

    2012-01-01

    Local structure of dirubidium tetralithium tris(selenate(VI)) dihydrate — Rb 2 Li 4 (SeO 4 ) 3 · 2H 2 O has been determined basing on the modeling of X-ray diffuse scattering. The origin of observed structured diffuse streaks is SeO 4 tetrahedra switching between two alternative positions in two quasi-planar layers existing in each unit cell and formation of domains with specific SeO 4 tetrahedra configuration locally fulfilling condition for C-centering in the 2a×2b×c superstructure cell. The local structure solution is characterized by a uniform distribution of rather large domains (ca. thousand of unit cells) in two layers, but also monodomains can be taken into account. Inside a single domain SeO 4 tetrahedra are ordered along ab-diagonal forming two-string ribbons. Inside the ribbons SeO 4 and LiO 4 tetrahedra share the oxygen corners, whereas ribbons are bound to each other by a net of hydrogen bonds and fastened by corner sharing SeO 4 tetrahedra of the neighboring layers. - Graphical abstract: Experimental sections of the reciprocal space showing diffraction effects observed for RLSO. Bragg spots are visible on sections with integer indices (1 kl section — on the left), streaks — on sections with fractional ones (1.5 kl section — on the right). At the center: resulting local structure of the A package modeled as a microdomain: two-string ribbons of ordered oxygen-corners-sharing SeO 4 and LiO 4 terahedra extended along ab-diagonal are seen; ribbons are bound by hydrogen bonds (shown in pink); the multiplied 2a×2b unit cell is shown. Highlights: ► X-ray diffuse scattering in RLSO was registered and modeled. ► The origin of diffuse streaks is SeO 4 tetrahedra switching in two structure layers. ► The local structure is characterized by a uniform distribution of microdomains. ► Inside a single domain SeO 4 tetrahedra are ordered along ab-diagonal forming ribbons. ► The ribbons are bound to each other by a net of hydrogen bonds.

  10. Raft-like membrane domains in pathogenic microorganisms.

    Science.gov (United States)

    Farnoud, Amir M; Toledo, Alvaro M; Konopka, James B; Del Poeta, Maurizio; London, Erwin

    2015-01-01

    The lipid bilayer of the plasma membrane is thought to be compartmentalized by the presence of lipid-protein microdomains. In eukaryotic cells, microdomains composed of sterols and sphingolipids, commonly known as lipid rafts, are believed to exist, and reports on the presence of sterol- or protein-mediated microdomains in bacterial cell membranes are also appearing. Despite increasing attention, little is known about microdomains in the plasma membrane of pathogenic microorganisms. This review attempts to provide an overview of the current state of knowledge of lipid rafts in pathogenic fungi and bacteria. The current literature on characterization of microdomains in pathogens is reviewed, and their potential role in growth, pathogenesis, and drug resistance is discussed. Better insight into the structure and function of membrane microdomains in pathogenic microorganisms might lead to a better understanding of their pathogenesis and development of raft-mediated approaches for therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Robust Optical Richness Estimation with Reduced Scatter

    Energy Technology Data Exchange (ETDEWEB)

    Rykoff, E.S.; /LBL, Berkeley; Koester, B.P.; /Chicago U. /Chicago U., KICP; Rozo, E.; /Chicago U. /Chicago U., KICP; Annis, J.; /Fermilab; Evrard, A.E.; /Michigan U. /Michigan U., MCTP; Hansen, S.M.; /Lick Observ.; Hao, J.; /Fermilab; Johnston, D.E.; /Fermilab; McKay, T.A.; /Michigan U. /Michigan U., MCTP; Wechsler, R.H.; /KIPAC, Menlo Park /SLAC

    2012-06-07

    Reducing the scatter between cluster mass and optical richness is a key goal for cluster cosmology from photometric catalogs. We consider various modifications to the red-sequence matched filter richness estimator of Rozo et al. (2009b), and evaluate their impact on the scatter in X-ray luminosity at fixed richness. Most significantly, we find that deeper luminosity cuts can reduce the recovered scatter, finding that {sigma}{sub ln L{sub X}|{lambda}} = 0.63 {+-} 0.02 for clusters with M{sub 500c} {approx}> 1.6 x 10{sup 14} h{sub 70}{sup -1} M{sub {circle_dot}}. The corresponding scatter in mass at fixed richness is {sigma}{sub ln M|{lambda}} {approx} 0.2-0.3 depending on the richness, comparable to that for total X-ray luminosity. We find that including blue galaxies in the richness estimate increases the scatter, as does weighting galaxies by their optical luminosity. We further demonstrate that our richness estimator is very robust. Specifically, the filter employed when estimating richness can be calibrated directly from the data, without requiring a-priori calibrations of the red-sequence. We also demonstrate that the recovered richness is robust to up to 50% uncertainties in the galaxy background, as well as to the choice of photometric filter employed, so long as the filters span the 4000 {angstrom} break of red-sequence galaxies. Consequently, our richness estimator can be used to compare richness estimates of different clusters, even if they do not share the same photometric data. Appendix A includes 'easy-bake' instructions for implementing our optimal richness estimator, and we are releasing an implementation of the code that works with SDSS data, as well as an augmented maxBCG catalog with the {lambda} richness measured for each cluster.

  12. Conservation and Biodiversity of Rich Fens

    DEFF Research Database (Denmark)

    Andersen, Dagmar Kappel

    2014-01-01

    Rich fen is a habitat type dependent on a constant supply of nutrient poor, calcium rich groundwater. A high, stable groundwater table, relatively high pH combined with nutrient poor conditions support a special and very species rich vegetation including many rare and threatened plant species. In...

  13. Optical cell sorting with multiple imaging modalities

    DEFF Research Database (Denmark)

    Banas, Andrew; Carrissemoux, Caro; Palima, Darwin

    2017-01-01

    healthy cells. With the richness of visual information, a lot of microscopy techniques have been developed and have been crucial in biological studies. To utilize their complementary advantages we adopt both fluorescence and brightfield imaging in our optical cell sorter. Brightfield imaging has...... the advantage of being non-invasive, thus maintaining cell viability. Fluorescence imaging, on the other hand, takes advantages of the chemical specificity of fluorescence markers and can validate machine vision results from brightfield images. Visually identified cells are sorted using optical manipulation...

  14. Updates on Software development for a RICH detector

    Science.gov (United States)

    Voloshin, Andrew; Benmokhtar, Fatiha; Lendacky, Andrew; Goodwill, Justin

    2017-01-01

    The CLAS12 detector at Thomas Jefferson National Accelerator Facility (TJNAF) is undergoing an upgrade. One of the improvements is the addition of a Ring Imaging Cherenkov (RICH) detector to improve particle identification in the 3-8 GeV/c momentum range. Approximately 400 multi anode photomultiplier tubes (MAPMTs) are going to be used to detect Cherenkov Radiation in the single photoelectron spectra (SPS). Software development for slow control as well as online monitoring is under development. I will be presenting my work on the development of a java based programs for a monitor and explain its interaction with a Mysql database where the MAPMTs information is stored as well as the techniques used to visualize Cherenkov rings.

  15. Event reconstruction for the RICH prototype beamtest data 2012 and 2014

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Semen [II. Physikalisches Institut, JLU Giessen (Germany); Collaboration: CBM-Collaboration

    2016-07-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility will investigate the QCD phase diagram at high net baryon densities and moderate temperatures in A+A collisions from 2-11 AGeV (SIS100). Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detectors (TRD). A real size prototype of the RICH detector was tested together with other CBM prototypes (TRD, TOF) at the CERN PS/T9 beam line in 2012 and 2014. In 2014 for the first time the data format used the FLESnet protocol from CBM delivering free streaming data. The analysis was fully performed within the CBMROOT framework. In this contribution the event reconstruction methods which were used for obtained data are discussed. Rings were reconstructed using an algorithm based on the Hough Transform method and their parameters were derived with high accuracy by circle and ellipse fitting procedures. Results of the application of the presented algorithms are also presented.

  16. Is torrefaction of polysaccharides-rich biomass equivalent to carbonization of lignin-rich biomass?

    Science.gov (United States)

    Bilgic, E; Yaman, S; Haykiri-Acma, H; Kucukbayrak, S

    2016-01-01

    Waste biomass species such as lignin-rich hazelnut shell (HS) and polysaccharides-rich sunflower seed shell (SSS) were subjected to torrefaction at 300°C and carbonization at 600°C under nitrogen. The structural variations in torrefied and carbonized biomasses were compared. Also, the burning characteristics under dry air and pure oxygen (oxy-combustion) conditions were investigated. It was concluded that the effects of carbonization on HS are almost comparable with the effects of torrefaction on SSS in terms of devolatilization and deoxygenation potentials and the increases in carbon content and the heating value. Consequently, it can be proposed that torrefaction does not provide efficient devolatilization from the lignin-rich biomass while it is relatively more efficient for polysaccharides-rich biomass. Heat-induced variations in biomass led to significant changes in the burning characteristics under both burning conditions. That is, low temperature reactivity of biomass reduced considerably and the burning shifted to higher temperatures with very high burning rates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Advances in fast-atom-bombardment mass spectroscopy

    International Nuclear Information System (INIS)

    Hemling, M.E.

    1986-01-01

    A comparison of fast atom bombardment and field desorption mass spectrometry was made to determine relative sensitivity and applicability. A series of glycosphingolipids and a series of protected oligonucleotides of known structure were analyzed to ascertain the potential utility of fast atom bombardment mass spectrometry in the structural elucidation of novel compounds in these classes. Negative ion mass markers were also developed. Fast atom bombardment was found to be one-to-two orders of magnitude more sensitive than field desorption based on the analysis of a limited number of compounds from several classes. Superior sensitivity was not universal and field desorption was clearly better in certain cases. In the negative ion mode in particular, fast atom bombardment was found to be a useful tool for the determination of the primary structure of glycosphingolipids and oligonucleotides. Carbohydrate sequence and branching information, and a fatty acid and lipid base composition were readily obtained from the mass spectra of glycosphingolipids while bidirectional nucleotide sequence, nucleotide base, and protecting group assignments were obtained for oligonucleotides. Based on this knowledge, a tentative structure of a human peripheral nervous system glycosphingolipid implicated in certain cases of disorders such as amyotrophic lateral sclerosis, Lou Gehrig's Disease, was proposed. Suitable negative ion mass markers were found in dispersions of poly(ethylene) and poly(propylene)glycols in a triethylenetetramine matrix, a matrix which also proved useful in the analysis of glycosphingolipids. These polyglycol dispersions provided ions for calibration to 2300 daltons

  18. The LHCb RICH silica aerogel performance with LHC data

    CERN Multimedia

    Perego, D L

    2010-01-01

    In the LHCb detector at the Large Hadron Collider, powerful charged particle identification is performed by Ring Imaging Cherenkov (RICH) technology. In order to cover the full geometric acceptance and the wide momentum range (1-100 GeV/c), two detectors with three Cherenkov radiators have been designed and installed. In the medium (10-40 GeV/c) and high (30-100 GeV/c) momentum range, gas radiators are used (C4F10 and CF4 respectively). In the low momentum range (1 to a few GeV/c) pion/kaon/proton separation will be done with photons produced in solid silica aerogel. A set of 16 tiles, with the large transverse dimensions ever (20x20 cm$^2$) and nominal refractive index 1.03 have been produced. The tiles have excellent optical properties and homogeneity of refractive index within the tile of ~1%. The first data collected at LHC are used to understand the behaviour of the RICH: preliminary results will be presented and discussed on the performance of silica aerogel and of the gas radiators C4F10 and CF4.

  19. The high voltage system of the RICH and the multiplicity study with LHCb data

    CERN Document Server

    Fanchini, E; Pessina, G; Gys, T

    2011-01-01

    This thesis is about the work done during my PhD at the Univerità degli studi di Milano–Bicocca. During these three years I was involved in the RICH group of the LHCb experiment. LHCb is one of the four main experiments at CERN. It uses proton–proton collisions to study CP violation and to search for new physics beyond the Standard Model in the $b$ decays. One of the main feature of the experiment is the particle identification, performed with the Ring Imaging Cherenkov (RICH) technology. The RICH detects Cherenkov rings via photons emitted by charged particles traversing radiator materials. The photon detection system used consists of pixel Hybrid Photon Detectors (HPDs). They convert photons into photoelectrons which are then accelerated by means of a field generated by three electrodes, biased with high voltages (-18 kV, -17.7 kV and -14.8 kV), onto the silicon pixel anode. The energy released in the pixel is converted into a binary output. My work can be divided in two main parts: the hardware and th...

  20. Performance of Front-End Readout System for PHENIX RICH

    International Nuclear Information System (INIS)

    Oyama, K.; Hamagaki, H.; Nishimura, S.; Shigaki, K.; Hayano, R.S.; Hibino, M.; Kametani, S.; Kikuchi, J.; Matsumoto, T.; Sakaguchi, T.; Ebisu, K.; Hara, H.; Tanaka, Y.; Ushiroda, T.; Moscone, C.G.; Wintenberg, A.L.; Young, G.R.

    1999-01-01

    A front-end electronics system has been developed for the Ring Imaging Cerenkov (RICH) detector of the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC), Brookhaven National Laboratory (BNL). A high speed custom back-plane with source synchronous bus architecture, a full custom analog ASIC, and board modules with FPGA's and CPLD's were developed for high performance real time data acquisition. The transfer rate of the back-lane has reached 640 MB/s with 128 bits data bus. Total transaction time is estimated to be less than 30 micros per event. The design specifications and test results of the system are presented in this paper

  1. Design and test results of the AMS RICH detector

    CERN Document Server

    Casadei, D.

    2002-01-01

    The AMS-02 detector will operate for at least 3 years on the International Space Station, measuring cosmic ray spectra at about 400 km above sea level over a wide range of geomagnetic latitude. The proximity focusing ring imaging \\v{C}erenkov counter of AMS-02 will measure the particle velocity $\\beta$ with $\\approx 0.1%$ uncertainty, making possible to discriminate Beryllium isotopes up to about 15 GeV/nucl. In addition its charge measurement will allow to study the elemental composition of cosmic rays up to Iron. A prototype of the RICH detector was tested with cosmic rays and on a ion beam accelerated by SPS, at CERN (October 2002).

  2. Multiple Nebular Gas Reservoirs Recorded by Oxygen Isotope Variation in a Spinel-Rich CAI in CO3 MIL 090019

    Science.gov (United States)

    Simon, J. I.; Simon, S. B.; Nguyen, A. N.; Ross, D. K.; Messenger, S.

    2017-07-01

    We conducted NanoSIMS ion imaging studies of a primitive spinel-rich CAI from the MIL 090019 CO3 chondrite. It records radial O-isotopic heterogeneity among multiple occurrences of the same mineral, reflecting distinct nebular O-isotopic reservoirs.

  3. Adaptive Reactive Rich Internet Applications

    Science.gov (United States)

    Schmidt, Kay-Uwe; Stühmer, Roland; Dörflinger, Jörg; Rahmani, Tirdad; Thomas, Susan; Stojanovic, Ljiljana

    Rich Internet Applications significantly raise the user experience compared with legacy page-based Web applications because of their highly responsive user interfaces. Although this is a tremendous advance, it does not solve the problem of the one-size-fits-all approach1 of current Web applications. So although Rich Internet Applications put the user in a position to interact seamlessly with the Web application, they do not adapt to the context in which the user is currently working. In this paper we address the on-the-fly personalization of Rich Internet Applications. We introduce the concept of ARRIAs: Adaptive Reactive Rich Internet Applications and elaborate on how they are able to adapt to the current working context the user is engaged in. An architecture for the ad hoc adaptation of Rich Internet Applications is presented as well as a holistic framework and tools for the realization of our on-the-fly personalization approach. We divided both the architecture and the framework into two levels: offline/design-time and online/run-time. For design-time we explain how to use ontologies in order to annotate Rich Internet Applications and how to use these annotations for conceptual Web usage mining. Furthermore, we describe how to create client-side executable rules from the semantic data mining results. We present our declarative lightweight rule language tailored to the needs of being executed directly on the client. Because of the event-driven nature of the user interfaces of Rich Internet Applications, we designed a lightweight rule language based on the event-condition-action paradigm.2 At run-time the interactions of a user are tracked directly on the client and in real-time a user model is built up. The user model then acts as input to and is evaluated by our client-side complex event processing and rule engine.

  4. The large-area hybrid-optics CLAS12 RICH detector: Tests of innovative components

    International Nuclear Information System (INIS)

    Contalbrigo, M.; Baltzell, N.; Benmokhtar, F.; Barion, L.; Cisbani, E.; El Alaoui, A.; Hafidi, K.; Hoek, M.; Kubarovsky, V.; Lagamba, L.; Lucherini, V.; Malaguti, R.; Mirazita, M.; Montgomery, R.; Movsisyan, A.; Musico, P.; Orecchini, D.; Orlandi, A.; Pappalardo, L.L.; Pereira, S.

    2014-01-01

    A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadronization and hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and densely packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). The preliminary results of individual detector component tests and of the prototype performance at test-beams are reported here. - Highlights: • A novel hybrid-optics configuration was proven to work with a large RICH prototype. • Innovative RICH components were studied both in laboratory tests and test-beams. • Aerogel of large Rayleigh scattering length at n=1.05 was characterized. • Novel vs commercially available multi-anode photomultipliers were compared. • The response of SiPM matrices to Cherenkov light was tested at various temperatures

  5. The large-area hybrid-optics CLAS12 RICH detector: Tests of innovative components

    Energy Technology Data Exchange (ETDEWEB)

    Contalbrigo, M., E-mail: contalbrigo@fe.infn.it [INFN Sezione di Ferrara and University of Ferrara (Italy); Baltzell, N. [Argonne National Laboratory, IL (United States); Benmokhtar, F. [Christopher Newport University, VA (United States); Duquesne University, PA (United States); Barion, L. [INFN Sezione di Ferrara and University of Ferrara (Italy); Cisbani, E. [INFN Sezione di Roma – Gruppo Collega to Sanità (Italy); Italian National Institute of Health (Italy); El Alaoui, A. [Universidad Tecnica Federico Santa Maria, Valparaiso (Chile); Argonne National Laboratory, IL (United States); Hafidi, K. [Argonne National Laboratory, IL (United States); Hoek, M. [Glasgow University (United Kingdom); J. Gutenberg Universität, Mainz (Germany); Kubarovsky, V. [Thomas Jefferson National Laboratory, VA (United States); Lagamba, L. [INFN Sezione di Bari, University of Bari (Italy); Lucherini, V. [INFN Laboratori Nazionali di Frascati (Italy); Malaguti, R. [INFN Sezione di Ferrara and University of Ferrara (Italy); Mirazita, M. [INFN Laboratori Nazionali di Frascati (Italy); Montgomery, R. [Glasgow University (United Kingdom); INFN Laboratori Nazionali di Frascati (Italy); Movsisyan, A. [INFN Sezione di Ferrara and University of Ferrara (Italy); Musico, P. [INFN Sezione di Genova (Italy); Orecchini, D.; Orlandi, A. [INFN Laboratori Nazionali di Frascati (Italy); Pappalardo, L.L. [INFN Sezione di Ferrara and University of Ferrara (Italy); Pereira, S. [INFN Laboratori Nazionali di Frascati (Italy); and others

    2014-12-01

    A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadronization and hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and densely packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). The preliminary results of individual detector component tests and of the prototype performance at test-beams are reported here. - Highlights: • A novel hybrid-optics configuration was proven to work with a large RICH prototype. • Innovative RICH components were studied both in laboratory tests and test-beams. • Aerogel of large Rayleigh scattering length at n=1.05 was characterized. • Novel vs commercially available multi-anode photomultipliers were compared. • The response of SiPM matrices to Cherenkov light was tested at various temperatures.

  6. OXYGEN-RICH SUPERNOVA REMNANT IN THE LARGE MAGELLANIC CLOUD

    Science.gov (United States)

    2002-01-01

    This is a NASA Hubble Space Telescope image of the tattered debris of a star that exploded 3,000 years ago as a supernova. This supernova remnant, called N132D, lies 169,000 light-years away in the satellite galaxy, the Large Magellanic Cloud. A Hubble Wide Field Planetary Camera 2 image of the inner regions of the supernova remnant shows the complex collisions that take place as fast moving ejecta slam into cool, dense interstellar clouds. This level of detail in the expanding filaments could only be seen previously in much closer supernova remnants. Now, Hubble's capabilities extend the detailed study of supernovae out to the distance of a neighboring galaxy. Material thrown out from the interior of the exploded star at velocities of more than four million miles per hour (2,000 kilometers per second) plows into neighboring clouds to create luminescent shock fronts. The blue-green filaments in the image correspond to oxygen-rich gas ejected from the core of the star. The oxygen-rich filaments glow as they pass through a network of shock fronts reflected off dense interstellar clouds that surrounded the exploded star. These dense clouds, which appear as reddish filaments, also glow as the shock wave from the supernova crushes and heats the clouds. Supernova remnants provide a rare opportunity to observe directly the interiors of stars far more massive than our Sun. The precursor star to this remnant, which was located slightly below and left of center in the image, is estimated to have been 25 times the mass of our Sun. These stars 'cook' heavier elements through nuclear fusion, including oxygen, nitrogen, carbon, iron etc., and the titanic supernova explosions scatter this material back into space where it is used to create new generations of stars. This is the mechanism by which the gas and dust that formed our solar system became enriched with the elements that sustain life on this planet. Hubble spectroscopic observations will be used to determine the exact

  7. LHCb RICH Upgrade: an overview on the photon detector and the electronics system

    CERN Multimedia

    Cassina, Lorenzo

    2015-01-01

    The LHCb experiment is one of the four detectors operating at the LHC at CERN and it is mainly devoted to CP violation measurements and the search for new physics in beauty and charm hadrons rare decays. The data from the two Ring Image Cherenkov (RICH-1 and RICH-2) detectors are essential to identify particles in a wide momentum range. Up to now the luminosity has reached up to 4 . $10^{32}$ cm$^{-2}$s$^{-1}$ with 50 ns bunch spacing and 3 fb$^{-1}$ have been collected since 2010. From 2019 onwards 14 TeV collisions with luminosities reaching up to 2 . $10^{33}$ cm$^{-2}$s$^{-1}$ with 25 ns bunch spacing are planned, with the goal of collecting 5 fb$^{-1}$ of data per year. In order to avoid degradation of the RICH detectors particle identification performance at such high rate (40 MHz), a detector upgrade is necessary. The present photodetectors (HPDs equipped with encapsulated 1 MHz readout chips) will be replaced with flat panel MaPMTs read out by external chips, designed for this purpose. The 25.4x25.4 m...

  8. Concept and design of an alignment monitoring system for the CBM RICH mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Bendarouach, Jordan [Justus Liebig University (Germany); Collaboration: CBM-Collaboration

    2016-07-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR (Facility for Antiproton and Ion Research) complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures in A+A collisions from 2-11 AGeV (SIS100) beam energy. One of the key detector components required for this CBM physics program is the RICH (Ring Imaging CHerenkov) detector, developed for efficient and clean electron identification and pion suppression. The detector consists of about 80 spherical glass mirror tiles, distributed over two sphere parts. An important aspect to guarantee a stable operation of the RICH detector is the alignment of the mirrors. A method originally developed and inspired by the HERA-B experiment uses recorded data to assess mirror alignment of the RICH mirror system. Measurements of Cherenkov distances and angles on the PMT plane may reveal potential misalignments of the considered tile. If mirror misalignment is revealed, it can be subsequently included and rectified by correction routines, which should mostly increase ring reconstruction as well as ring-track matching efficiencies. Results of this alignment method based on simulated events, reproducing potential mirror misalignments, its limits and first correction routines are presented.

  9. Research: Rags to Rags? Riches to Riches?

    Science.gov (United States)

    Bracey, Gerald W.

    2004-01-01

    Everyone has read about what might be called the "gold gap"--how the rich in this country are getting richer and controlling an ever-larger share of the nation's wealth. The Century Foundation has started publishing "Reality Check", a series of guides to campaign issues that sometimes finds gaps in these types of cherished delusions. The guides…

  10. Robust inverse scattering full waveform seismic tomography for imaging complex structure

    International Nuclear Information System (INIS)

    Nurhandoko, Bagus Endar B.; Sukmana, Indriani; Wibowo, Satryo; Deny, Agus; Kurniadi, Rizal; Widowati, Sri; Mubarok, Syahrul; Susilowati; Kaswandhi

    2012-01-01

    Seismic tomography becomes important tool recently for imaging complex subsurface. It is well known that imaging complex rich fault zone is difficult. In this paper, The application of time domain inverse scattering wave tomography to image the complex fault zone would be shown on this paper, especially an efficient time domain inverse scattering tomography and their run in cluster parallel computer which has been developed. This algorithm is purely based on scattering theory through solving Lippmann Schwienger integral by using Born's approximation. In this paper, it is shown the robustness of this algorithm especially in avoiding the inversion trapped in local minimum to reach global minimum. A large data are solved by windowing and blocking technique of memory as well as computation. Parameter of windowing computation is based on shot gather's aperture. This windowing technique reduces memory as well as computation significantly. This parallel algorithm is done by means cluster system of 120 processors from 20 nodes of AMD Phenom II. Benchmarking of this algorithm is done by means Marmoussi model which can be representative of complex rich fault area. It is shown that the proposed method can image clearly the rich fault and complex zone in Marmoussi model even though the initial model is quite far from the true model. Therefore, this method can be as one of solution to image the very complex mode.

  11. Robust inverse scattering full waveform seismic tomography for imaging complex structure

    Energy Technology Data Exchange (ETDEWEB)

    Nurhandoko, Bagus Endar B.; Sukmana, Indriani; Wibowo, Satryo; Deny, Agus; Kurniadi, Rizal; Widowati, Sri; Mubarok, Syahrul; Susilowati; Kaswandhi [Wave Inversion and Subsurface Fluid Imaging Research (WISFIR) Lab., Complex System Research Division, Physics Department, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung. and Rock Fluid Imaging Lab., Rock Physics and Cluster C (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung (Indonesia); Physics Department of Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung, Indonesia and Institut Teknologi Telkom, Bandung (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung (Indonesia)

    2012-06-20

    Seismic tomography becomes important tool recently for imaging complex subsurface. It is well known that imaging complex rich fault zone is difficult. In this paper, The application of time domain inverse scattering wave tomography to image the complex fault zone would be shown on this paper, especially an efficient time domain inverse scattering tomography and their run in cluster parallel computer which has been developed. This algorithm is purely based on scattering theory through solving Lippmann Schwienger integral by using Born's approximation. In this paper, it is shown the robustness of this algorithm especially in avoiding the inversion trapped in local minimum to reach global minimum. A large data are solved by windowing and blocking technique of memory as well as computation. Parameter of windowing computation is based on shot gather's aperture. This windowing technique reduces memory as well as computation significantly. This parallel algorithm is done by means cluster system of 120 processors from 20 nodes of AMD Phenom II. Benchmarking of this algorithm is done by means Marmoussi model which can be representative of complex rich fault area. It is shown that the proposed method can image clearly the rich fault and complex zone in Marmoussi model even though the initial model is quite far from the true model. Therefore, this method can be as one of solution to image the very complex mode.

  12. SANS and SAXS study of block copolymer/homopolymer mixtures

    International Nuclear Information System (INIS)

    Hasegawa, Hirokazu; Tanaka, Hideaki; Hashimoto, Takeji; Han, C.C.

    1991-01-01

    The lateral and vertical components of the radius of gyration for a single block copolymer chain and those of a single homopolymer chain in the lamellar microdomain space formed by a mixture of diblock copolymers and homopolymers were investigated by means of small-angle neutron scattering (SANS) and the microdomain structures by small-angle X-ray scattering (SAXS). The homopolymers whose molecular weights are much smaller than that of the corresponding chains of the block copolymers were used so that the homopolymers were uniformly solubilized in the corresponding microdomains. The SANS result suggests that the homopolymer chains in the microdomain space as well as the block copolymer chains are more compressed in the direction parallel to the interface and more stretched in the direction perpendicular to the interface than the corresponding unperturbed polymer chains with the same molecular weight. On increasing the volume fraction of the homopolymers the thickness of the lamellar microdomains increases. The block copolymer chains were found to undergo an isochoric affine deformation on addition of the homopolymers or with the change of the thickness of the lamellar microdomains. (orig.)

  13. SANS study of polymer chains in confined space

    International Nuclear Information System (INIS)

    Hasegawa, Hirokazu; Tanaka, Hideaki; Hashimoto, Takeji; Han, C.C.

    1993-01-01

    The lateral and vertical components of the radius of gyration for a single block copolymer chain in the lamellar microdomain space formed by a mixture of diblock copolymers and homopolymers were investigated by means of small-angle neutron scattering (SANS), and the microdomain structures by small-angle X-ray scattering (SAXS). We used the homopolymers whose molecular weights are much smaller than that of the corresponding chains of the block copolymers so that the homopolymers are uniformly solubilized in the corresponding microdomains. The SANS result suggests that the block copolymer chains in the microdomain space are more compressed in the direction parallel to the interface and more stretched in the direction perpendicular to the interface than the corresponding unperturbed polymer chains with the same molecular weight. With increasing the volume fraction of the homopolymers the thickness of the lamellar microdomains increases. The block copolymer chains were found to undergo an isochoric affine deformation on addition of the homopolymers or with the change of the thickness of the lamellar microdomains. (author)

  14. Onlay bone augmentation on mouse calvarial bone using a hydroxyapatite/collagen composite material with total blood or platelet-rich plasma.

    Science.gov (United States)

    Ohba, Seigo; Sumita, Yoshinori; Umebayashi, Mayumi; Yoshimura, Hitoshi; Yoshida, Hisato; Matsuda, Shinpei; Kimura, Hideki; Asahina, Izumi; Sano, Kazuo

    2016-01-01

    The aim of this study was to assess newly formed onlay bone on mouse calvarial bone using a new artificial bone material, a hydroxyapatite/collagen composite, with total blood or platelet-rich plasma. The hydroxyapatite/collagen composite material with normal saline, total blood or platelet-rich plasma was transplanted on mouse calvarial bone. The mice were sacrificed and the specimens were harvested four weeks after surgery. The newly formed bone area was measured on hematoxylin and eosin stained specimens using Image J software. The hydroxyapatite/collagen composite materials with total blood or platelet-rich plasma induced a significantly greater amount of newly formed bone than that with normal saline. Moreover, bone marrow was observed four weeks after surgery in the transplanted materials with total blood or platelet-rich plasma but not with normal saline. However, there were no significant differences in the amount of newly formed bone between materials used with total blood versus platelet-rich plasma. The hydroxyapatite/collagen composite material was valid for onlay bone augmentation and this material should be soaked in total blood or platelet-rich plasma prior to transplantation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Polycyclic aromatic hydrocarbons and molecular hydrogen in oxygen-rich planetary nebulae: the case of NGC 6720.

    Science.gov (United States)

    Cox, N L J; Pilleri, P; Berné, O; Cernicharo, J; Joblin, C

    2016-02-11

    Evolved stars are primary sources for the formation of polycyclic aromatic hydrocarbons (PAHs) and dust grains. Their circumstellar chemistry is usually designated as either oxygen-rich or carbon-rich, although dual-dust chemistry objects, whose infrared spectra reveal both silicate- and carbon-dust features, are also known. The exact origin and nature of this dual-dust chemistry is not yet understood. Spitzer -IRS mid-infrared spectroscopic imaging of the nearby, oxygen-rich planetary nebula NGC 6720 reveals the presence of the 11.3 μ m aromatic (PAH) emission band. It is attributed to emission from neutral PAHs, since no band is observed in the 7-8 μ m range. The spatial distribution of PAHs is found to closely follow that of the warm clumpy molecular hydrogen emission. Emission from both neutral PAHs and warm H 2 is likely to arise from photo-dissociation regions associated with dense knots that are located within the main ring. The presence of PAHs together with the previously derived high abundance of free carbon (relative to CO) suggest that the local conditions in an oxygen-rich environment can also become conducive to in-situ formation of large carbonaceous molecules, such as PAHs, via a bottom-up chemical pathway. In this scenario, the same stellar source can enrich the interstellar medium with both oxygen-rich dust and large carbonaceous molecules.

  16. Mixed Media Richness and Computer-Mediated Communications

    OpenAIRE

    Atkins, Anthony B.

    2006-01-01

    Mixed richness communications occur when a participant in a conversation receives a different media or combination of media than they transmit. Mixed richness communications occur in the workplace when technical, physiological or practical limitations prevent the use of the same media on both ends of a conversation. Prior research in CMC has focused on same-richness communications, and the design guidelines that are available for same-richness communications may not be applicable to mixed-r...

  17. Species richness, area and climate correlates

    DEFF Research Database (Denmark)

    Nogues, David Bravo; Bastos Araujo, Miguel

    2006-01-01

    affects: (1) the selection of climate variables entering a species richness model; and (2) the accuracy of models in predicting species richness in unsampled grid cells. Location Western Europe. Methods Models are developed for European plant, breeding bird, mammal and herptile species richness using...... seven climate variables. Generalized additive models are used to relate species richness, climate and area. Results We found that variation in the grid cell area was large (50 × 50 km: 8-3311 km2; 220 × 220: 193-55,100 km2), but this did not affect the selection of variables in the models. Similarly...... support the assumption that variation in near-equal area cells may be of second-order importance for models explaining or predicting species richness in relation to climate, although there is a possibility that drops in accuracy might increase with grid cell size. The results are, however, contingent...

  18. Event reconstruction for the CBM-RICH prototype beamtest data in 2014

    Science.gov (United States)

    Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H.; Belogurov, S.; Bendarouach, J.; Boldyreva, N.; Deveaux, C.; Dobyrn, V.; Dürr, M.; Eschke, J.; Förtsch, J.; Heep, J.; Höhne, C.; Kampert, K.-H.; Kochenda, L.; Kopfer, J.; Kravtsov, P.; Kres, I.; Lebedev, S.; Lebedeva, E.; Leonova, E.; Linev, S.; Mahmoud, T.; Michel, J.; Miftakhov, N.; Niebur, W.; Ovcharenko, E.; Patel, V.; Pauly, C.; Pfeifer, D.; Querchfeld, S.; Rautenberg, J.; Reinecke, S.; Riabov, Y.; Roshchin, E.; Samsonov, V.; Schetinin, V.; Tarasenkova, O.; Traxler, M.; Ugur, C.; Vznuzdaev, E.; Vznuzdaev, M.

    2017-12-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility will investigate the QCD phase diagram at high net baryon densities and moderate temperatures in A+A collisions from 2 to 11 AGeV (SIS100). Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detectors (TRD). A real size prototype of the RICH detector was tested together with other CBM groups at the CERN PS/T9 beam line in 2014. For the first time the data format used the FLESnet protocol from CBM delivering free streaming data. The analysis was fully performed within the CBMROOT framework. In this contribution the data analysis and the event reconstruction methods which were used for obtained data are discussed. Rings were reconstructed using an algorithm based on the Hough Transform method and their parameters were derived with high accuracy by circle and ellipse fitting procedures. We present results of the application of the presented algorithms. In particular we compare results with and without Wavelength shifting (WLS) coating.

  19. The Physics and Chemistry of Oxygen-Rich Circumstellar Envelopes as Traced by Simple Molecules

    Science.gov (United States)

    Wong, Ka Tat

    2018-04-01

    multiple radio inversion lines of NH3. Furthermore, mid-infrared absorption of NH3 has been observed by the NASA Infrared Telescope Facility (IRTF) for IK Tau and VY CMa. Full radiative transfer modelling including mid-infrared pumping to the first vibrationally excited state (v2=1) has been carried out to reproduce the observed emission and absorption spectra and to retrieve the NH3 abundances in the targets. It is found that the NH3 emission in the CSEs of the targets arises from localised spatial-kinematic structures in which the gas density may be higher than in the surrounding gas. Circumstellar shocks may contribute to, but cannot fully account for, the formation of the molecule. Besides circumstellar chemistry, our understanding of the dust formation and wind-driving mechanisms of oxygen-rich evolved stars is still incomplete. One of the obstacles in the past was the difficulty in imaging the dust condensation and wind acceleration zones due to the lack of high-angular resolution instruments. Thanks to the Atacama Large Millimeter/submillimeter Array (ALMA), which has the longest baseline of about 15 km, we are now able to produce high-fidelity images at unprecedented angular resolutions of tens of milliarcseconds (mas) in the (sub)millimetre regime. Such angular resolutions, which are comparable to the stellar radii of nearby objects, are necessary to understand the gas dynamics and chemical evolution in the pulsating atmosphere and dust formation zone of nearby AGB stars. The eponymous Mira-type long-period variable, o Cet, was observed as a Science Verification target during the first ALMA Long Baseline Campaign that took place in 2014. The observations produced images of the stellar radio photosphere and the molecular transitions of SiO and H2O at an angular resolution of about 30 mas near 220 GHz (1.3 mm). The millimetre stellar disc of o Cet was resolved and modelled. More importantly, this is the first time that molecular line absorption against the

  20. Domain walls collision in Fe-rich and Co-rich glass covered microwires

    Directory of Open Access Journals (Sweden)

    Gonzalez J.

    2013-01-01

    Full Text Available We report the results of the investigation of domain walls propagation in Fe-rich and Co-rich microwires performed using Sixtus-Tonks and magneto-optical Kerr effect techniques. It was found that under certain experimental conditions we are able to create the regime of the motion of two domain walls moving to opposite directions which terminates by the collision of the domain walls. Also the domain walls collision was visualized using magneto-optical Kerr effect microscope when the surface giant Barkhausen jump induced by circular magnetic field has been observed.

  1. Exosomal lipids impact notch signaling and induce death of human pancreatic tumoral SOJ-6 cells.

    Directory of Open Access Journals (Sweden)

    Sadia Beloribi

    Full Text Available Exosomes are of increasing interest as alternative mode of cell-to-cell communication. We previously reported that exosomes secreted by human SOJ-6 pancreatic tumor cells induce (glycoprotein ligand-independent cell death and inhibit Notch-1 pathway, this latter being particularly active during carcinogenesis and in cancer stem cells. Therefore, we asked whether exosomal lipids were key-elements for cell death and hypothesized that cholesterol-rich membrane microdomains were privileged sites of exosome interactions with tumor cells. To address these questions and based on the lipid composition of exosomes from SOJ-6 cells (Ristorcelli et al. (2008 FASEB J. 22; 3358-3369 enriched in cholesterol and sphingomyelin (lipids forming liquid-ordered phase, Lo and depleted in phospholipids (lipids forming liquid-disordered phase, Ld, we designed Synthetic Exosome-Like Nanoparticles (SELN with ratios Lo/Ld from 3.0 to 6.0 framing that of SOJ-6 cell exosomes. SELN decreased tumor cell survival, the higher the Lo/Ld ratio, the lower the cell survival. This decreased survival was due to activation of cell death with inhibition of Notch pathway. FRET analyses indicated fusions/exchanges of SELN with cell membranes. Fluorescent SELN co-localized with the ganglioside GM1 then with Rab5A, markers of lipid microdomains and of early endosomes, respectively. These interactions occurred at lipid microdomains of plasma and/or endosome membranes where the Notch-1 pathway matures. We thus demonstrated a major role for lipids in interactions between SELN and tumor cells, and in the ensued cell death. To our knowledge this is the first report on such effects of lipidic nanoparticles on tumor cell behavior. This may have implications in tumor progression.

  2. Multiply imaged Transient Events in Cluster Lenses

    Science.gov (United States)

    Narasimha, Delampady

    2018-04-01

    ARIES had a successful gravitational microlens project during 1998-2002. A similar monitor for Transient Events in galaxies at high redshift lensed by rich galaxy-clusters provides a challenging possibility with important cosmological implications. Rich galaxy-clusters at intermediate redshifts are powerful gravitational lenses which produce multiple images, in the shape of giant arcs of 5-20" extent, of distant background galaxies in their field. Weak lens shear of the background galaxy distribution can reliably trace the lens mass profile. Multiple images of supernovae or GRBs in the background galaxies can be recorded in a systematic monitor of the system. An unlensed high redshift supernova might not be observable, but when lensed by a galaxy-cluster, it will stand out because the point event brightens relative to the host. The color profile of a high redshift lensed point event will be much more reliable than an unlensed one due to much less host contamination. An estimate of the time delay enables observation of the full light curve of the subsequent images of the event. ARIES can have outside collaboration for multiband simultaneous lightcurves of other images. The measured time delay and position of images of the transient event provide better cosmological constraints including distance scale of the Universe. The Devasthal telescope can detect one or more events by monitoring half a dozen cluster fields over three years time.

  3. Structural elucidation, molecular representation and solvent interactions of vitrinite-rich and inertinite-rich South African coals

    Science.gov (United States)

    van Niekerk, Daniel

    The structural differences and similarities of two Permian-aged South African coals, vitrinite-rich Waterberg and inertinite-rich Highveld coals (similar rank, carbon content and Permian age), were evaluated. With South African coals the opportunity presented itself to study not only Permian-aged Gondwana vitrinite but also inertinite. It was expected that these coals would differ from Northern hemisphere Carboniferous coals. It was concluded from various structural data that both coals, although different in maceral composition and depositional basins, are similar in their base structural composition. The main differences were that the inertinite-rich Highveld coal was more ordered, more aromatic, and had less hydrogen than the vitrinite-rich Waterberg coal. Analytical data were used to construct large-scale advanced molecular representations for vitrinite-rich Waterberg and inertinite-rich Highveld coals. The three-dimensional models were structurally diverse with a molecular weight range of 78 to 1900 amu. The vitrinite-rich coal model consisted of 18,572 atoms and 191 individual molecules and the inertinite-rich coal model consisted of 14,242 atoms and 158 individual molecules. This largescale modeling effort was enabled by the development of various PERL scripts to automate various visualization and analytical aspects. Coal swelling studies were conducted using the traditional pack-bed swelling method and a new novel single-particle stop-motion videography swelling method with NMP and CS2/NMP solvents. The pack-bed swelling showed that vitrinite-rich coal had a greater swelling extent and that swelling extent for both coals was greater in CS2/NMP binary solvent than for NMP. Single-particle swelling experiments showed that both coals, for both solvents, exhibit overshoot-type and climbing-type swelling behaviors. Inertinite-coal had a faster swelling rate, in both solvents, than the vitrinite-rich coal. The single-particle swelling data was used to calculate

  4. CBM RICH geometry optimization

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoud, Tariq; Hoehne, Claudia [II. Physikalisches Institut, Giessen Univ. (Germany); Collaboration: CBM-Collaboration

    2016-07-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures in A+A collisions from 2-11 AGeV (SIS100) beam energy. The main electron identification detector in the CBM experiment will be a RICH detector with a CO{sub 2} gaseous-radiator, focusing spherical glass mirrors, and MAPMT photo-detectors being placed on a PMT-plane. The RICH detector is located directly behind the CBM dipole magnet. As the final magnet geometry is now available, some changes in the RICH geometry become necessary. In order to guarantee a magnetic field of 1 mT at maximum in the PMT plane for effective operation of the MAPMTs, two measures have to be taken: The PMT plane is moved outwards of the stray field by tilting the mirrors by 10 degrees and shielding boxes have been designed. In this contribution the results of the geometry optimization procedure are presented.

  5. LITHIUM-RICH GIANTS IN GLOBULAR CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, Evan N.; Cohen, Judith G. [California Institute of Technology, 1200 E. California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Guhathakurta, Puragra [UCO/Lick Observatory and Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Zhang, Andrew J. [The Harker School, 500 Saratoga Avenue, San Jose, CA 95129 (United States); Hong, Jerry [Palo Alto High School, 50 Embarcadero Road, Palo Alto, CA, 94301 (United States); Guo, Michelle [Stanford University, 450 Serra Mall, Stanford, CA 94305 (United States); Guo, Rachel [Irvington High School, 41800 Blacow Road, Fremont, CA 94538 (United States); Cunha, Katia [Observatório Nacional, São Cristóvão Rio de Janeiro (Brazil)

    2016-03-10

    Although red giants deplete lithium on their surfaces, some giants are Li-rich. Intermediate-mass asymptotic giant branch (AGB) stars can generate Li through the Cameron–Fowler conveyor, but the existence of Li-rich, low-mass red giant branch (RGB) stars is puzzling. Globular clusters are the best sites to examine this phenomenon because it is straightforward to determine membership in the cluster and to identify the evolutionary state of each star. In 72 hours of Keck/DEIMOS exposures in 25 clusters, we found four Li-rich RGB and two Li-rich AGB stars. There were 1696 RGB and 125 AGB stars with measurements or upper limits consistent with normal abundances of Li. Hence, the frequency of Li-richness in globular clusters is (0.2 ± 0.1)% for the RGB, (1.6 ± 1.1)% for the AGB, and (0.3 ± 0.1)% for all giants. Because the Li-rich RGB stars are on the lower RGB, Li self-generation mechanisms proposed to occur at the luminosity function bump or He core flash cannot explain these four lower RGB stars. We propose the following origin for Li enrichment: (1) All luminous giants experience a brief phase of Li enrichment at the He core flash. (2) All post-RGB stars with binary companions on the lower RGB will engage in mass transfer. This scenario predicts that 0.1% of lower RGB stars will appear Li-rich due to mass transfer from a recently Li-enhanced companion. This frequency is at the lower end of our confidence interval.

  6. LHCb RICH Upgrade: an overview of the photon detector and electronic system

    Science.gov (United States)

    Cassina, L.

    2016-01-01

    The LHCb experiment is one of the four large detectors operating at the LHC at CERN and it is mainly devoted to CP violation measurements and to the search for new physics in rare decays of beauty and charm hadrons. The data from the two Ring Image Cherenkov (RICH-1 and RICH-2) detectors are essential to identify particles in a wide momentum range. From 2019 onwards 14 TeV collisions with luminosities reaching up to 2 × 1033 cm-2s-1 with 25 ns bunch spacing are planned, with the goal of collecting 5 fb-1 of data per year. In order to avoid degradation of the PID performance at such high rate (40 MHz), the RICH detector has to be upgraded. New photodetectors (Multi-anode photomultiplier tubes, MaPMTs) have been chosen and will be read out using an 8-channel chip, named CLARO, designed to sustain a photon counting rate up to 40 MHz, while minimizing the power consumption and the cross-talk. A 128-bit digital register allows selection of thresholds and attenuation values and provides features useful for testing and debugging. Photosensors and electronics are arranged in basic units, the first prototypes of which have been tested in charged particle beams in autumn 2014. An overview of the CLARO features and of the readout electronics is presented.

  7. Medical image registration for analysis

    International Nuclear Information System (INIS)

    Petrovic, V.

    2006-01-01

    Full text: Image registration techniques represent a rich family of image processing and analysis tools that aim to provide spatial correspondences across sets of medical images of similar and disparate anatomies and modalities. Image registration is a fundamental and usually the first step in medical image analysis and this paper presents a number of advanced techniques as well as demonstrates some of the advanced medical image analysis techniques they make possible. A number of both rigid and non-rigid medical image alignment algorithms of equivalent and merely consistent anatomical structures respectively are presented. The algorithms are compared in terms of their practical aims, inputs, computational complexity and level of operator (e.g. diagnostician) interaction. In particular, the focus of the methods discussion is placed on the applications and practical benefits of medical image registration. Results of medical image registration on a number of different imaging modalities and anatomies are presented demonstrating the accuracy and robustness of their application. Medical image registration is quickly becoming ubiquitous in medical imaging departments with the results of such algorithms increasingly used in complex medical image analysis and diagnostics. This paper aims to demonstrate at least part of the reason why

  8. Using Google Earth Surface Metrics to Predict Plant Species Richness in a Complex Landscape

    Directory of Open Access Journals (Sweden)

    Sebastián Block

    2016-10-01

    Full Text Available Google Earth provides a freely available, global mosaic of high-resolution imagery from different sensors that has become popular in environmental and ecological studies. However, such imagery lacks the near-infrared band often used in studying vegetation, thus its potential for estimating vegetation properties remains unclear. In this study, we assess the potential of Google Earth imagery to describe and predict vegetation attributes. Further, we compare it to the potential of SPOT imagery, which has additional spectral information. We measured basal area, vegetation height, crown cover, density of individuals, and species richness in 60 plots in the oak forests of a complex volcanic landscape in central Mexico. We modelled each vegetation attribute as a function of surface metrics derived from Google Earth and SPOT images, and selected the best-supported linear models from each source. Total species richness was the best-described and predicted variable: the best Google Earth-based model explained nearly as much variation in species richness as its SPOT counterpart (R2 = 0.44 and 0.51, respectively. However, Google Earth metrics emerged as poor predictors of all remaining vegetation attributes, whilst SPOT metrics showed potential for predicting vegetation height. We conclude that Google Earth imagery can be used to estimate species richness in complex landscapes. As it is freely available, Google Earth can broaden the use of remote sensing by researchers and managers in low-income tropical countries where most biodiversity hotspots are found.

  9. A facile cathode design combining Ni-rich layered oxides with Li-rich layered oxides for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Song, Bohang; Li, Wangda; Yan, Pengfei; Oh, Seung-Min; Wang, Chong-Min; Manthiram, Arumugam

    2016-09-01

    A facile synthesis method was developed to prepare xLi2MnO3·(1-x)LiNi0.7Co0.15Mn0.15O2 (x = 0, 0.03, 0.07, 0.10, 0.20, and 0.30 as molar ratio) cathode materials, combining the advantages of high specific capacity from Ni-rich layered phase and surface chemical stability from Li-rich layered phase. X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM) and electrochemical charge/discharge performance confirm the formation of a Li-rich layered phase with C2/m symmetry. Most importantly, high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) reveals a spatial relationship that Li-rich nano-domain islands are integrated into a conventional Ni-rich layered matrix (R$\\bar{3}$m). This is the first time that Li-rich phase has been directly observed inside a particle at the nano-scale, when the overall composition of layered compounds (Li1+δNixMnyM1-x-y-δO2, M refers to transition metal elements) is Ni-rich (x > 0.5) rather than Mn-rich (y > 0.5). Remarkably, xLi2MnO3·(1-x)LiNi0.7Co0.15Mn0.15O2 cathode with optimized x value shows superior electrochemical performance at C/3, i.e., 170 mA h g-1 with 90.3 % of capacity retention after 400 cycles at 25 °C and 164 mA h g-1 with 81.3 % capacity retention after 200 cycles at 55 °C.

  10. CT and MR imaging of the liver. Clinical importance of nutritional status

    International Nuclear Information System (INIS)

    Leander, P.; Sjoeberg, S.; Hoeglund, P.

    2000-01-01

    Purpose: In an experimental study in rats a correlation between nutritional status and hepatic attenuation in CT and signal intensities in MR imaging was shown. Is physiological nutritional status of importance in clinical CT and MR imaging? Material and methods: In a cross-over study including 12 healthy volunteers (6 women and 6 men, mean age 34 years), CT and MR imaging of the liver were performed with nutritional status at three different levels, i.e., normal, fasting and after glycogen-rich meals. CT and MR were performed on clinical imaging systems and hepatic attenuation and signal intensity, respectively, were assessed. In MR, T1-weighted, proton density-weighted and T2-weighted pulse-sequences were used. Results: In CT there were significantly (p<0.01) higher liver attenuations in normal nutritional status and after glycogen rich-meals compared to the fasting condition. The difference between fasting and glycogen-rich meals were 10.5 HU for men, 7.4 for women and mean 8.8 HU for all 12 volunteers. In MR imaging the differences were small and non-significant. The results of this study are in accordance with an earlier experimental study in rats. Conclusion: In CT it may be of importance not to have patients in a fasting condition as it lowers the attenuation in normal liver tissue. The findings are important for planning of clinical studies where hepatic attenuation will be assessed and may be of some importance in clinical CT. In MR imaging the results indicate that the nutritional status is of less importance

  11. Platelet-rich fibrin: the benefits.

    Science.gov (United States)

    Kumar, Yuvika Raj; Mohanty, Sujata; Verma, Mahesh; Kaur, Raunaq Reet; Bhatia, Priyanka; Kumar, Varun Raj; Chaudhary, Zainab

    2016-01-01

    Current published data presents confusing results about the effects of platelet-rich fibrin on bone, and there is a need for studies that throw light on its effect. Our main objective therefore was to evaluate (by fractal analysis) osseous regeneration in extraction sockets with and without platelet-rich fibrin in a study with a substantial sample and a reliable technique to calibrate its effects on bone cells. We also assessed the soft tissue response. Thirty-four patients had their bilaterally impacted third molars (68 surgical sites) extracted in this split-mouth study, following which platelet-rich fibrin was placed in one of the sockets. Patients were followed up clinically and radiographically, and a pain score and fractal analysis were used to evaluate healing of soft tissue and bone, respectively. We conclude that platelet-rich fibrin improves healing of both soft and hard tissues. Although osseous healing did not differ significantly between the groups, healing of soft tissue as judged by the pain score was significantly better in the experimental group. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  12. Parvovirus B19 VLP recognizes globoside in supported lipid bilayers.

    Science.gov (United States)

    Nasir, Waqas; Nilsson, Jonas; Olofsson, Sigvard; Bally, Marta; Rydell, Gustaf E

    2014-05-01

    Studies have suggested that the glycosphingolipid globoside (Gb4Cer) is a receptor for human parvovirus B19. Virus-like particles bind to Gb4Cer on thin-layer chromatograms, but a direct interaction between the virus and lipid membrane-associated Gb4Cer has been debated. Here, we characterized the binding of parvovirus B19 VP1/VP2 virus-like particles to glycosphingolipids (i) on thin-layer chromatograms (TLCs) and (ii) incorporated into supported lipid bilayers (SLBs) acting as cell-membrane mimics. The binding specificities of parvovirus B19 determined in the two systems were in good agreement; the VLP recognized both Gb4Cer and the Forssman glycosphingolipid on TLCs and in SLBs compatible with the role of Gb4Cer as a receptor for this virus. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Real-time Image Processing for Microscopy-based Label-free Imaging Flow Cytometry in a Microfluidic Chip.

    Science.gov (United States)

    Heo, Young Jin; Lee, Donghyeon; Kang, Junsu; Lee, Keondo; Chung, Wan Kyun

    2017-09-14

    Imaging flow cytometry (IFC) is an emerging technology that acquires single-cell images at high-throughput for analysis of a cell population. Rich information that comes from high sensitivity and spatial resolution of a single-cell microscopic image is beneficial for single-cell analysis in various biological applications. In this paper, we present a fast image-processing pipeline (R-MOD: Real-time Moving Object Detector) based on deep learning for high-throughput microscopy-based label-free IFC in a microfluidic chip. The R-MOD pipeline acquires all single-cell images of cells in flow, and identifies the acquired images as a real-time process with minimum hardware that consists of a microscope and a high-speed camera. Experiments show that R-MOD has the fast and reliable accuracy (500 fps and 93.3% mAP), and is expected to be used as a powerful tool for biomedical and clinical applications.

  14. Platelet-Rich Plasma Increases Pigmentation.

    Science.gov (United States)

    Uysal, Cagri A; Ertas, Nilgun Markal

    2017-11-01

    Platelet-rich plasma (PRP) is an autologous solution of plasma containing 4 to 7 times the baseline concentration of human platelets. Platelet-rich plasma has been widely popular in facial rejuvenation to attenuate wrinkles and has been practically used. The authors have been encountering various patients of increased hiperpigmentation following PRP applications that were performed to attenuate the postinflammatory hiperpigmentation especially after laser treatment. The authors have been using PRP for facial rejuvenation in selected patients and in 1 patient the authors have encountered increased pigmentation over the pigmented skin lesions that were present before the application. The authors recommend that the PRP might increase pigmentation especially in the face region and precautions might be taken before and after the application. Platelet-rich plasma should not be used for the treatment of post inflammatory hiperpigmentation.

  15. Thermomechanical behavior of tin-rich (lead-free) solders

    Science.gov (United States)

    Sidhu, Rajen Singh

    In order to adequately characterize the behavior of ball-grid-array (BGA) Pb-free solder spheres in electronic devices, the microstructure and thermomechanical behavior need to be studied. Microstructure characterization of pure Sn, Sn-0.7Cu, Sn-3.5Ag, and Sn-3.9Ag-0.7Cu alloys was conducted using optical microscopy, scanning electron microscopy, transmission electron microscopy, image analysis, and a novel serial sectioning 3D reconstruction process. Microstructure-based finite-element method (FEM) modeling of deformation in Sn-3.5Ag alloy was conducted, and it will be shown that this technique is more accurate when compared to traditional unit cell models for simulating and understanding material behavior. The effect of cooling rate on microstructure and creep behavior of bulk Sn-rich solders was studied. The creep behavior was evaluated at 25, 95, and 120°C. Faster cooling rates were found to increase the creep strength of the solders due to refinement of the solder microstructure. The creep behavior of Sn-rich single solder spheres reflowed on Cu substrates was studied at 25, 60, 95, and 130°C. Testing was conducted using a microforce testing system, with lap-shear geometry samples. The solder joints displayed two distinct creep behaviors: (a) precipitation-strengthening (Sn-3.5Ag and Sn-3.9Ag-0.7Cu) and (b) power law creep accommodated by grain boundary sliding (GBS) (Sn and Sn-0.7Cu). The relationship between microstructural features (i.e. intermetallic particle size and spacing), stress exponents, threshold stress, and activation energies are discussed. The relationship between small-length scale creep behavior and bulk behavior is also addressed. To better understand the damage evolution in Sn-rich solder joints during thermal fatigue, the local damage will be correlated to the cyclic hysteresis behavior and crystal orientations present in the Sn phase of solder joints. FEM modeling will also be utilized to better understand the macroscopic and local

  16. Characterisation of the Photon Detection System for the LHCb RICH Detector Upgrade

    CERN Document Server

    AUTHOR|(CDS)2097582; D'Ambrosio, Carmelo; Easo, Sajan

    The LHCb Experiment will be upgraded during Long Shutdown II of the Large Hadron Collider (LHC) in 2019 and 2020. The goal of the upgrade is to efficiently use the increased instantaneous luminosity in LHC Run 3 and to collect data at the proton collision rate of 40 MHz. The Ring Imaging Cherenkov (RICH) particle identification detectors will be upgraded to perform in the new operating conditions with continuing reliability. The photon detection system will be replaced using multi-anode photomultiplier tubes (MaPMTs) and associated read-out electronics. The photon detection chain was studied at CERN using a pulsed laser to test the system under high event rates and high photon intensities. The behaviour of two types of MaPMTs which are foreseen for the upgrade is presented for varying rates and intensities, and different applied bias voltages. A simulation was created to model the photon detection chain using the Geant4 simulation toolkit. The RICH Upgrade test beam using 180 GeV positive hadrons from CERN SP...

  17. The AQUA-RICH atmospheric neutrino experiment

    CERN Document Server

    Antonioli, P; Bellagamba, L; Chesi, Enrico Guido; Cindolo, F; De Pasquale, S; Ekelöf, T J C; Garbini, M; Giusti, P; Grossheim, A; Pesci, A; Learned, J G; Margotti, A; Pinfold, James L; Sartorelli, G; Séguinot, Jacques; Tarantino, A; Weilhammer, Peter; Ypsilantis, Thomas; Zichichi, A; Zuber, K

    1999-01-01

    We describe a 125 m diameter spherical detector containing 1 Mt of water, capable of high rate observation of atmospheric neutrino events (30000/y). The ring imaging Cherenkov (RICH) technique is used to measure velocity, momentum and direction of particles produced by neutrinos interacting in water. The detector will be sited outdoors (under a 50 m water shield) in a natural (further excavated) pit, probably in Sicily. Spherical reflecting mirrors focus Cherenkov light produced by secondaries from interacting neutrinos. Photons are detected by 5310 hybrid photodiodes (HPDs) of 1 m diameter each with 396 pads of 45*45 mm/sup 2/ on the photocathode surface, demagnified to 9*9 mm/sup 2/ on the silicon sensor. For most tracks the ring width will be dominated by multiple scattering which should allow momentum to be determined. Hadrons of momentum p

  18. A Shotgun Proteomic Approach Reveals That Fe Deficiency Causes Marked Changes in the Protein Profiles of Plasma Membrane and Detergent-Resistant Microdomain Preparations from Beta vulgaris Roots.

    Science.gov (United States)

    Gutierrez-Carbonell, Elain; Takahashi, Daisuke; Lüthje, Sabine; González-Reyes, José Antonio; Mongrand, Sébastien; Contreras-Moreira, Bruno; Abadía, Anunciación; Uemura, Matsuo; Abadía, Javier; López-Millán, Ana Flor

    2016-08-05

    In the present study we have used label-free shotgun proteomic analysis to examine the effects of Fe deficiency on the protein profiles of highly pure sugar beet root plasma membrane (PM) preparations and detergent-resistant membranes (DRMs), the latter as an approach to study microdomains. Altogether, 545 proteins were detected, with 52 and 68 of them changing significantly with Fe deficiency in PM and DRM, respectively. Functional categorization of these proteins showed that signaling and general and vesicle-related transport accounted for approximately 50% of the differences in both PM and DRM, indicating that from a qualitative point of view changes induced by Fe deficiency are similar in both preparations. Results indicate that Fe deficiency has an impact in phosphorylation processes at the PM level and highlight the involvement of signaling proteins, especially those from the 14-3-3 family. Lipid profiling revealed Fe-deficiency-induced decreases in phosphatidic acid derivatives, which may impair vesicle formation, in agreement with the decreases measured in proteins related to intracellular trafficking and secretion. The modifications induced by Fe deficiency in the relative enrichment of proteins in DRMs revealed the existence of a group of cytoplasmic proteins that appears to be more attached to the PM in conditions of Fe deficiency.

  19. Synthesis and study of neutron-rich nuclides

    International Nuclear Information System (INIS)

    Luo Yixiao

    1995-01-01

    During the past few years our understanding of the decay properties and nuclear structure has been extended in a systematic fashion for the neutron-rich nuclei. This review will first sketch the production and identification of the neutron-rich nuclei throughout the whole mass region, and will then discuss the impressive progress in the studies of the exotic decay properties and nuclear structure of neutron-rich nuclei. Their astrophysical implications will also be outlined

  20. High speed intravascular photoacoustic imaging of atherosclerotic arteries (Conference Presentation)

    Science.gov (United States)

    Piao, Zhonglie; Ma, Teng; Qu, Yueqiao; Li, Jiawen; Yu, Mingyue; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2016-02-01

    Cardiovascular disease is the leading cause of death in the industrialized nations. Accurate quantification of both the morphology and composition of lipid-rich vulnerable atherosclerotic plaque are essential for early detection and optimal treatment in clinics. In previous works, intravascular photoacoustic (IVPA) imaging for detection of lipid-rich plaque within coronary artery walls has been demonstrated in ex vivo, but the imaging speed is still limited. In order to increase the imaging speed, a high repetition rate laser is needed. In this work, we present a high speed integrated IVPA/US imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A miniature catheter with 1.0 mm outer diameter was designed with a 200 μm multimode fiber and an ultrasound transducer with 45 MHz center frequency. The fiber was polished at 38 degree and enclosed in a glass capillary for total internal reflection. An optical/electrical rotary junction and pull-back mechanism was applied for rotating and linearly scanning the catheter to obtain three-dimensional imaging. Atherosclerotic rabbit abdominal aorta was imaged as two frame/second at 1725 nm. Furthermore, by wide tuning range of the laser wavelength from 1680 nm to 1770 nm, spectroscopic photoacoustic analysis of lipid-mimicking phantom and an human atherosclerotic artery was performed ex vivo. The results demonstrated that the developed IVPA/US imaging system is capable for high speed intravascular imaging for plaque detection.

  1. High-Temperature Nucleosynthesis Processes on the Proton-Rich Side of Stability: the Alpha-Rich Freezeout and the rp^2-Process

    Science.gov (United States)

    Meyer, Bradley S.

    2001-10-01

    Nucleosynthesis on the proton-rich side of stability has at least two intriguing aspects. First, the most abundant of the stable iron-group isotopes, such as ^48Ti, ^52Cr, and ^56,57Fe, are synthesized as proton-rich, radioactive parents in alpha-rich freezeouts from equilibrium. The production of these radioactive progenitors depends in large measure on reactions on the proton-rich side of stability. The second intriguing aspect is that explosive nucleosynthesis in a hydrogen-rich environment (namely, the rp-process) may be associated with exotic astrophysical settings, such as x-ray bursts, and may be responsible for production of some of the light p-process nuclei (for example, ^92,94Mo and ^96,98Ru). We have developed web-based tools to help nuclear physicists determine which nuclear reactions on the proton-rich side of stability govern the nucleosynthesis in these processes. For the alpha-rich freezeout, one may determine the effect of any one of 2,140 reactions on the yield of any isotope in the nuclear reaction network with the web calculator. As a relevant example, I will discuss the governing role of ^57Ni (n,p)^57Co in the synthesis of the important astronomical observable ^57Co. As for explosive, proton-rich burning, I will discuss the synthesis of p-process nuclei in the repetitive rp-process (the rp^2-process). movies/rp.html>Movies of the rp^2-process illustrate its important features and give some indications of the important nuclear reactions.

  2. A SAR IMAGE REGISTRATION METHOD BASED ON SIFT ALGORITHM

    Directory of Open Access Journals (Sweden)

    W. Lu

    2017-09-01

    Full Text Available In order to improve the stability and rapidity of synthetic aperture radar (SAR images matching, an effective method was presented. Firstly, the adaptive smoothing filtering was employed for image denoising in image processing based on Wallis filtering to avoid the follow-up noise is amplified. Secondly, feature points were extracted by a simplified SIFT algorithm. Finally, the exact matching of the images was achieved with these points. Compared with the existing methods, it not only maintains the richness of features, but a-lso reduces the noise of the image. The simulation results show that the proposed algorithm can achieve better matching effect.

  3. AN EXTREME STARBURST IN THE CORE OF A RICH GALAXY CLUSTER AT z = 1.7

    International Nuclear Information System (INIS)

    Webb, Tracy; Bonaventura, Nina; Delahaye, Anna; Noble, Allison; Yee, H. K. C.; DeGroot, Andrew; Wilson, Gillian; Foltz, Ryan; Muzzin, Adam; Chapman, Scott; Cooper, Mike; Lidman, Chris; Surace, Jason; Dunne, Loretta; Geach, James; Hayden, Brian; Hildebrandt, Hendrik; Huang, Jiasheng; Pope, Alexandra; Smith, Matthew W. L.

    2015-01-01

    We have discovered an optically rich galaxy cluster at z = 1.7089 with star formation occurring in close proximity to the central galaxy. The system, SpARCS104922.6+564032.5, was detected within the Spitzer Adaptation of the red-sequence Cluster Survey, and confirmed through Keck-MOSFIRE spectroscopy. The rest-frame optical richness of N gal (500 kpc) = 30 ± 8 implies a total halo mass, within 500 kpc, of ∼3.8 ± 1.2 × 10 14 M ⊙ , comparable to other clusters at or above this redshift. There is a wealth of ancillary data available, including Canada–France–Hawaii Telescope optical, UKIRT-K, Spitzer-IRAC/MIPS, and Herschel-SPIRE. This work adds submillimeter imaging with the SCUBA2 camera on the James Clerk Maxwell Telescope and near-infrared imaging with the Hubble Space Telescope. The mid/far-infrared (M/FIR) data detect an Ultra-luminous Infrared Galaxy spatially coincident with the central galaxy, with L IR = 6.2 ± 0.9 × 10 12 L ⊙ . The detection of polycyclic aromatic hydrocarbons at z = 1.7 in a Spitzer-IRS spectrum of the source implies the FIR luminosity is dominated by star formation (an Active Galactic Nucleus contribution of 20%) with a rate of ∼860 ± 130 M ⊙ yr −1 . The optical source corresponding to the IR emission is likely a chain of >10 individual clumps arranged as “beads on a string” over a linear scale of 66 kpc. Its morphology and proximity to the Brightest Cluster Galaxy (BCG) imply a gas-rich interaction at the center of the cluster triggered the star formation. This system indicates that wet mergers may be an important process in forming the stellar mass of BCGs at early times

  4. AN EXTREME STARBURST IN THE CORE OF A RICH GALAXY CLUSTER AT z = 1.7

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Tracy; Bonaventura, Nina; Delahaye, Anna [Department of Physics, McGill University, 3600 rue University, Montréal, Québec, H3P 1T3 (Canada); Noble, Allison; Yee, H. K. C. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON, M5S 3H4 (Canada); DeGroot, Andrew; Wilson, Gillian; Foltz, Ryan [Department of Physics and Astronomy, University of California, Riverside, 900 University Avenue, Riverside, CA 92521 (United States); Muzzin, Adam; Chapman, Scott [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Cooper, Mike [Centre for Galaxy Evolution, Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697 (United States); Lidman, Chris [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia); Surace, Jason [Spitzer Space Science Centre, California Institute of Technology, Pasadena, CA 91125 (United States); Dunne, Loretta [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Geach, James [Center for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Hayden, Brian [Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Hildebrandt, Hendrik [Argelander-Institute fur Astronomie, Auf dem Hugel 71, D-53121 Bonn (Germany); Huang, Jiasheng [National Astronomical Observatories of China, Chinese Academy of Sciences, Beijing 100012 (China); Pope, Alexandra [Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 011003 (United States); Smith, Matthew W. L. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, Wales CF24 3AA (United Kingdom); and others

    2015-08-20

    We have discovered an optically rich galaxy cluster at z = 1.7089 with star formation occurring in close proximity to the central galaxy. The system, SpARCS104922.6+564032.5, was detected within the Spitzer Adaptation of the red-sequence Cluster Survey, and confirmed through Keck-MOSFIRE spectroscopy. The rest-frame optical richness of N{sub gal} (500 kpc) = 30 ± 8 implies a total halo mass, within 500 kpc, of ∼3.8 ± 1.2 × 10{sup 14} M{sub ⊙}, comparable to other clusters at or above this redshift. There is a wealth of ancillary data available, including Canada–France–Hawaii Telescope optical, UKIRT-K, Spitzer-IRAC/MIPS, and Herschel-SPIRE. This work adds submillimeter imaging with the SCUBA2 camera on the James Clerk Maxwell Telescope and near-infrared imaging with the Hubble Space Telescope. The mid/far-infrared (M/FIR) data detect an Ultra-luminous Infrared Galaxy spatially coincident with the central galaxy, with L{sub IR} = 6.2 ± 0.9 × 10{sup 12} L{sub ⊙}. The detection of polycyclic aromatic hydrocarbons at z = 1.7 in a Spitzer-IRS spectrum of the source implies the FIR luminosity is dominated by star formation (an Active Galactic Nucleus contribution of 20%) with a rate of ∼860 ± 130 M{sub ⊙} yr{sup −1}. The optical source corresponding to the IR emission is likely a chain of >10 individual clumps arranged as “beads on a string” over a linear scale of 66 kpc. Its morphology and proximity to the Brightest Cluster Galaxy (BCG) imply a gas-rich interaction at the center of the cluster triggered the star formation. This system indicates that wet mergers may be an important process in forming the stellar mass of BCGs at early times.

  5. Direct hierarchical assembly of nanoparticles

    Science.gov (United States)

    Xu, Ting; Zhao, Yue; Thorkelsson, Kari

    2014-07-22

    The present invention provides hierarchical assemblies of a block copolymer, a bifunctional linking compound and a nanoparticle. The block copolymers form one micro-domain and the nanoparticles another micro-domain.

  6. Neutron rich nuclei around 132Sn

    International Nuclear Information System (INIS)

    Bhattacharya, Sarmishtha

    2016-01-01

    The neutron rich nuclei with few particles or holes in 132 Sn have various experimental and theoretical interest to understand the evolution of nuclear structure around the doubly magic shell closure Z=50 and N=82. Some of the exotic neutron rich nuclei in this mass region are situated near waiting points in the r-process path and are of special astrophysical interest. Neutron rich nuclei near 132 Sn have been studied using fission fragment spectroscopy. The lifetime of low lying isomeric states have been precisely measured and the beta decay from the ground and isomeric states have been characterized using gamma-ray spectroscopy

  7. Antimicrobial effect of platelet-rich plasma and platelet-rich fibrin.

    Science.gov (United States)

    Badade, Pallavi S; Mahale, Swapna A; Panjwani, Alisha A; Vaidya, Prutha D; Warang, Ayushya D

    2016-01-01

    Platelet concentrates have been extensively used in a variety of medical fields to promote soft- and hard-tissue regeneration. The significance behind their use lies in the abundance of growth factors (GFs) in platelets α-granules that promote wound healing. Other than releasing a pool of GFs upon activation, platelets also have many features that indicate their role in the anti-infective host defense. The aim of this study is to evaluate the antimicrobial activities of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) against periodontal disease-associated bacteria. Blood samples were obtained from ten adult male patients. PRP and PRF were procured using centrifugation. The antimicrobial activity of PRP and PRF was evaluated by microbial culturing using bacterial strains of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. P. gingivalis and A. actinomycetemcomitans were inhibited by PRP but not by PRF. PRP is a potentially useful substance in the fight against periodontal pathogens. This might represent a valuable property in adjunct to the enhancement of tissue regeneration.

  8. Instruments for radiation measurement in life sciences (5). ''Development of imaging technology in life science''. 9. Advantages of RI and fluorescence in imaging

    International Nuclear Information System (INIS)

    Furukawa, Takako; Jin, Zhao-Hui

    2009-01-01

    Imaging has been used as an effective research tool in many fields. In recent years, ''molecular imaging'' has come to attract a major attention as it studies molecular events in living animals and humans. Variety of modalities is used in molecular imaging, sometimes in combination, and the machines and techniques are going through rapid progress. Two of popular modalities among them are fluorescence imaging and radioisotope (RI) imaging such as positron emission tomography (PET) and single photon emission tomography (SPECT). Fluorescence imaging provides rich selection in imaging probes and the resolution can reach into sub-cellular level. RI imaging, especially PET, is superior to the others in quantitative analysis and the direct applicability to humans. In this article the two imaging modalities are overviewed comparing their characteristics. (author)

  9. The source rock characters of U-rich granite

    Energy Technology Data Exchange (ETDEWEB)

    Mingyue, Feng; Debao, He [CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Technology, Beijing Research Institute of Uranium Geology (China)

    2012-03-15

    This paper discusses the stratum composition, lithological association, uranium content of crust and the activation, migration, concentration of uranium at each tectonic cycle in South China. The authors point out that the source rock of U-rich granite is U-rich continental crust which is rich in Si, Al and K. The lithological association is mainly composed of terrestrial clastic rocks formation of mudstone and sandstone, mingled with intermediate-acidic, mafic pyroclastic rocks and carbonate rocks formation. During tectonic movements, the rocks had undergone regional metamorphism, migmatitization, granitization, and formed U-rich granites finally. (authors)

  10. The source rock characters of U-rich granite

    International Nuclear Information System (INIS)

    Feng Mingyue; He Debao

    2012-01-01

    This paper discusses the stratum composition, lithological association, uranium content of crust and the activation, migration, concentration of uranium at each tectonic cycle in South China. The authors point out that the source rock of U-rich granite is U-rich continental crust which is rich in Si, Al and K. The lithological association is mainly composed of terrestrial clastic rocks formation of mudstone and sandstone, mingled with intermediate-acidic, mafic pyroclastic rocks and carbonate rocks formation. During tectonic movements, the rocks had undergone regional metamorphism, migmatitization, granitization, and formed U-rich granites finally. (authors)

  11. Compositional Models of Hematite-Rich Spherules (Blueberries) at Meridiani Planum, Mars and Constraints on Their Formation

    Science.gov (United States)

    Schneider, A.; Mittlefehldt, D.

    2006-10-01

    The Mars Exploration Rover Opportunity discovered hematite-rich spherules (``blueberries'') believed to be diagenetic concretions formed in the bedrock in stagnant or slow-moving groundwater. These spherules likely precipitated from solution, but their origins are poorly understood. Three formation mechanisms are possible: inclusive, replacive and displacive. The first would result in a distinct spherule composition compared to the other two. We propose that chemical clues may help to constrain the nature of blueberry formation. We used Alpha Particle X-ray Spectrometer data for undisturbed soils that were blueberry-free and with visible blueberries at the surface in Microscopic Imager images. We made plots of the elements versus iron for the spherule-rich soils and compared them to a mixing line representative of a pure hematite end member spherule (called ``the zero model''). This modeled the replacive formation mechanism, in which pure hematite would replace all of the original material. If the spherules grew inclusively, chemical data should reflect a compositional component of the rock grains included during formation. Four models were developed to test for possible compositions of a rock component. These models could not easily explain the APXS data and thus demonstrate that the most plausible rock compositions are not components of blueberries.

  12. Silica aerogel radiator for use in the A-RICH system utilized in the Belle II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, Makoto, E-mail: makoto@hepburn.s.chiba-u.ac.jp [Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara (Japan); Department of Physics, Chiba University, Chiba (Japan); Adachi, Ichiro [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Hamada, Nao [Department of Physics, Toho University, Funabashi (Japan); Hara, Koji [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Iijima, Toru [Kobayashi–Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya (Japan); Iwata, Shuichi; Kakuno, Hidekazu [Department of Physics, Tokyo Metropolitan University, Hachioji (Japan); Kawai, Hideyuki [Department of Physics, Chiba University, Chiba (Japan); Korpar, Samo [Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor (Slovenia); Experimental High Energy Physics Department, Jožef Stefan Institute, Ljubljana (Slovenia); Križan, Peter [Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana (Slovenia); Experimental High Energy Physics Department, Jožef Stefan Institute, Ljubljana (Slovenia); Kumita, Tetsuro [Department of Physics, Tokyo Metropolitan University, Hachioji (Japan); Nishida, Shohei [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Ogawa, Satoru [Department of Physics, Toho University, Funabashi (Japan); Pestotnik, Rok; Šantelj, Luka; Seljak, Andrej [Experimental High Energy Physics Department, Jožef Stefan Institute, Ljubljana (Slovenia); Sumiyoshi, Takayuki [Department of Physics, Tokyo Metropolitan University, Hachioji (Japan); and others

    2014-12-01

    This paper presents recent progress in the development and mass production of large-area hydrophobic silica aerogels for use as radiators in the aerogel-based ring-imaging Cherenkov (A-RICH) counter, which will be installed in the forward end cap of the Belle II detector. The proximity-focusing A-RICH system is especially designed to identify charged kaons and pions. The refractive index of the installed aerogel Cherenkov radiators is approximately 1.05, and we aim for a separation capability exceeding 4σ at momenta up to 4 GeV/c. Large-area aerogel tiles (over 18×18×2 cm{sup 3}) were first fabricated in test productions by pin drying in addition to conventional methods. We proposed to fill the large end-cap region (area 3.5 m{sup 2}) with 124 water-jet-trimmed fan-shaped dual-layer-focusing aerogel combinations of different refractive indices (1.045 and 1.055). Guided by the test production results, we decided to manufacture aerogels by the conventional method and are currently proceeding with mass production. In an electron beam test undertaken at the DESY, we confirmed that the K/π separation capability of a prototype A-RICH counter exceeded 4σ at 4 GeV/c. - Highlights: • Aerogel tiling as a RICH radiator in the end cap of Belle II detector is proposed. • Conventional method for producing real-size aerogels is established. • No crack-free, real-size aerogels attained in the test production by pin drying. • Beam test confirms the utility of real-size aerogels made by conventional method. • Mass aerogel production for an actual RICH system started by conventional method.

  13. Image quality transfer and applications in diffusion MRI

    DEFF Research Database (Denmark)

    Alexander, Daniel C.; Zikic, Darko; Ghosh, Aurobrata

    2017-01-01

    and the uniquely rich diffusion MRI data set from the human connectome project (HCP). Results highlight potential benefits of IQT in both brain connectivity mapping and microstructure imaging. In brain connectivity mapping, IQT reveals, from standard data sets, thin connection pathways that tractography normally...

  14. Label-free imaging of arterial cells and extracellular matrix using a multimodal CARS microscope

    Science.gov (United States)

    Wang, Han-Wei; Le, Thuc T.; Cheng, Ji-Xin

    2008-04-01

    A multimodal nonlinear optical imaging system that integrates coherent anti-Stokes Raman scattering (CARS), sum-frequency generation (SFG), and two-photon excitation fluorescence (TPEF) on the same platform was developed and applied to visualize single cells and extracellular matrix in fresh carotid arteries. CARS signals arising from CH 2-rich membranes allowed visualization of endothelial cells and smooth muscle cells of the arterial wall. Additionally, CARS microscopy allowed vibrational imaging of elastin and collagen fibrils which are also rich in CH 2 bonds. The extracellular matrix organization was further confirmed by TPEF signals arising from elastin's autofluorescence and SFG signals arising from collagen fibrils' non-centrosymmetric structure. Label-free imaging of significant components of arterial tissues suggests the potential application of multimodal nonlinear optical microscopy to monitor onset and progression of arterial diseases.

  15. Two-proton knockout on neutron-rich nuclei

    International Nuclear Information System (INIS)

    Bazin, D.; Brown, B.A.; Campbell, C.M.; Church, J.A.; Dinca, D.C.; Enders, J.; Gade, A.; Glasmacher, T.; Hansen, P.G.; Mueller, W.F.; Olliver, H.; Perry, B.C.; Sherrill, B.M.; Terry, J.R.; Tostevin, J.A.

    2004-01-01

    Two-proton knockout reactions on neutron-rich nuclei [Phys. Rev. Lett. 91 (2003) 012501] have been studied in inverse kinematics at intermediate energy. Strong evidence that the two-proton removal from a neutron-rich system proceeds as a direct reaction is presented, together with a preliminary theoretical discussion of the partial cross sections based on eikonal reaction theory and the many-body shell model. They show that this reaction can be used to characterize the wave functions of the projectiles and holds great promise for the study of neutron-rich nuclei

  16. Structure of Light Neutron-rich Nuclei

    International Nuclear Information System (INIS)

    Dlouhy, Zdenek

    2007-01-01

    In this contribution we searched for irregularities in various separation energies in the frame of mass measurement of neutron-rich nuclei at GANIL. On this basis we can summarize that the new doubly magic nuclei are 8 He, 22 O and 24 O. They are characterized by extra stability and, except 24 O, they cannot accept and bind additional neutrons. However, if we add to these nuclei a proton we obtain 9 Li and 25 F which are the core for two-neutron halo nucleus 11 Li and enables that fluorine can bound even 6 more neutrons, respectively. In that aspect the doubly magic nuclei in the neutron-rich region can form the basis either for neutron halo or very neutron-rich nuclei. (Author)

  17. Lipid dip-pen nanolithography on self-assembled monolayers

    International Nuclear Information System (INIS)

    Gavutis, Martynas; Navikas, Vytautas; Rakickas, Tomas; Vaitekonis, Šarūnas; Valiokas, Ramūnas

    2016-01-01

    Dip-pen nanolithography (DPN) with lipids as an ink enables functional micro/nanopatterning on different substrates at high process speeds. However, only a few studies have addressed the influence of the physicochemical properties of the surface on the structure and phase behavior of DPN-printed lipid assemblies. Therefore, by combining the scanning probe and optical imaging techniques in this work we have analyzed lipid microdomain formation on the self-assembled monolayers (SAMs) on gold as well-defined model surfaces that displayed hydrophilic (protein-repellent) or hydrophobic (protein-adhesive) characteristics. We have found that on the tri(ethylene glycol)-terminated SAM the lipid ink transfer was fast (∼10 –1 μm 3 s −1 ), quasi-linear and it yielded unstable, sparsely packed lipid microspots. Contrary to this, on the methyl-terminated SAM the lipid transfer was ∼20 times slower, nonlinear, and the obtained stable dots of ∼1 μm in diameter consisted of lipid multilayers. Our comparative analysis indicated that the measured lipid transfer was consistent with the previously reported so-called polymer transfer model (Felts et al 2012, Nanotechnology 23 215301). Further on, by employing the observed distinct contrast in the DPN ink behavior we constructed confined lipid microdomains on pre-patterned SAMs, in which the lipids assembled either into monolayer or multilamellar phases. Such microdomains can be further utilized for lipid membrane mimetics in microarray and lab-on-a-chip device formats. (paper)

  18. Island Species Richness Increases with Habitat Diversity

    NARCIS (Netherlands)

    Hortal, J.; Triantis, K.A.; Meiri, S.; Thebault, E.M.C.; Sfenthourakis, S.

    2009-01-01

    Species richness is commonly thought to increase with habitat diversity. However, a recent theoretical model aiming to unify niche and island biogeography theories predicted a hump-shaped relationship between richness and habitat diversity. Given the contradiction between model results and previous

  19. Rapidly involuting congenital hemangioma (RICH): a brief case report

    OpenAIRE

    Scalise, Robert; Bolton, Joanna; Gibbs, Neil F

    2014-01-01

    Congenital hemangiomas (CH) are benign vascular neoplasms that proliferate in utero and have completed development by birth. Two subtypes of CH are recognized: rapidly involuting congenital hemangiomas (RICH) and non-involuting congenital hemangiomas (NICH). Involution of the RICH subtype often begins in the first weeks of life. NICH does not involute, allowing the distinction between RICH and NICH. We report a case of an infant with RICH occurring on the scalp, examined at birth and followed...

  20. Fast parallel ring recognition algorithm in the RICH detector of the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Lebedev, S.

    2011-01-01

    The Compressed Baryonic Matter (CBM)experiment at the future FAIR facility at Darmstadt will measure dileptons emitted from the hot and dense phase in heavy ion collisions. In case of an electron measurement, a high purity of identified electrons is required in order to suppress the background. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detector (TRD). Very fast data reconstruction is extremely important for CBM because of the huge amount of data which has to be handled. In this contribution, a parallelized ring recognition algorithm is presented. Modern CPUs have two features, which enable parallel programming. First, the SSE technology allows using the SIMD execution model. Second, multicore CPUs enable the use of multithreading. Both features have been implemented in the ring reconstruction of the RICH detector. A considerable speedup factor from 357 to 2.5 ms/event has been achieved including preceding code optimization for Intel Xeon X5550 processors at 2.67 GHz

  1. Ge-rich graded-index Si1-xGex devices for MID-IR integrated photonics

    Science.gov (United States)

    Ramirez, J. M.; Vakarin, V.; Liu, Q.; Frigerio, J.; Ballabio, A.; Le Roux, X.; Benedikovic, D.; Alonso-Ramos, C.; Isella, G.; Vivien, L.; Marris-Morini, D.

    2018-02-01

    Mid-infrared (mid-IR) silicon photonics is becoming a prominent research with remarkable potential in several applications such as in early medical diagnosis, safe communications, imaging, food safety and many more. In the quest for the best material platform to develop new photonic systems, Si and Ge depart with a notable advantage over other materials due to the high processing maturity accomplished during the last part of the 20th century through the deployment of the CMOS technology. From an optical viewpoint, combining Si with Ge to obtain SiGe alloys with controlled stoichiometry is also of interest for the photonic community since permits to increase the effective refractive index and the nonlinear parameter, providing a fascinating playground to exploit nonlinear effects. Furthermore, using Ge-rich SiGe gives access to a range of deep mid-IR wavelengths otherwise inaccessible (λ 2-20 μm). In this paper, we explore for the first time the limits of this approach by measuring the spectral loss characteristic over a broadband wavelength range spanning from λ = 5.5 μm to 8.5 μm. Three different SiGe waveguide platforms are compared, each one showing higher compactness than the preceding through the engineering of the vertical Ge profile, giving rise to different confinement characteristics to the propagating modes. A flat propagation loss characteristic of 2-3 dB/cm over the entire wavelength span is demonstrated in Ge-rich graded-index SiGe waveguides of only 6 μm thick. Also, the role of the overlap fraction of the confined optical mode with the Si-rich area at the bottom side of the epitaxial SiGe waveguide is put in perspective, revealing a lossy characteristic compared to the other designs were the optical mode is located in the Ge-rich area at the top of the waveguide uniquely. These Ge-rich graded-index SiGe waveguides may pave the way towards a new generation of photonic integrated circuits operating at deep mid-IR wavelengths.

  2. Imaging arterial cells, atherosclerosis, and restenosis by multimodal nonlinear optical microscopy

    Science.gov (United States)

    Wang, Han-Wei; Simianu, Vlad; Locker, Matthew J.; Sturek, Michael; Cheng, Ji-Xin

    2008-02-01

    By integrating sum-frequency generation (SFG), and two-photon excitation fluorescence (TPEF) on a coherent anti-Stokes Raman scattering (CARS) microscope platform, multimodal nonlinear optical (NLO) imaging of arteries and atherosclerotic lesions was demonstrated. CARS signals arising from CH II-rich membranes allowed visualization of endothelial cells and smooth muscle cells in a carotid artery. Additionally, CARS microscopy allowed vibrational imaging of elastin and collagen fibrils which are rich in CH II bonds in their cross-linking residues. The extracellular matrix organization was further confirmed by TPEF signals arising from elastin's autofluorescence and SFG signals arising from collagen fibrils' non-centrosymmetric structure. The system is capable of identifying different atherosclerotic lesion stages with sub-cellular resolution. The stages of atherosclerosis, such as macrophage infiltration, lipid-laden foam cell accumulation, extracellular lipid distribution, fibrous tissue deposition, plaque establishment, and formation of other complicated lesions could be viewed by our multimodal CARS microscope. Collagen percentages in the region adjacent to coronary artery stents were resolved. High correlation between NLO and histology imaging evidenced the validity of the NLO imaging. The capability of imaging significant components of an arterial wall and distinctive stages of atherosclerosis in a label-free manner suggests the potential application of multimodal nonlinear optical microscopy to monitor the onset and progression of arterial diseases.

  3. Local helioseismology: three-dimensional imaging of the solar interior

    NARCIS (Netherlands)

    Gizon, L.; Birch, A.C.; Spruit, H.C.

    2010-01-01

    The Sun supports a rich spectrum of internal waves that are continuously excited by turbulent convection. The Global Oscillation Network Group (GONG) network and the SOHO/MDI (Solar and Heliospheric Observatory/Michelson Doppler Imager) space instrument provide an exceptional database of spatially

  4. Firm size diversity, functional richness, and resilience

    Science.gov (United States)

    Garmestani, A.S.; Allen, Craig R.; Mittelstaedt, J.D.; Stow, C.A.; Ward, W.A.

    2006-01-01

    This paper applies recent advances in ecology to our understanding of firm development, sustainability, and economic development. The ecological literature indicates that the greater the functional richness of species in a system, the greater its resilience - that is, its ability to persist in the face of substantial changes in the environment. This paper focuses on the effects of functional richness across firm size on the ability of industries to survive in the face of economic change. Our results indicate that industries with a richness of industrial functions are more resilient to employment volatility. ?? 2006 Cambridge University Press.

  5. Modeling Aquatic Macroinvertebrate Richness Using Landscape Attributes

    Directory of Open Access Journals (Sweden)

    Marcia S. Meixler

    2015-01-01

    Full Text Available We used a rapid, repeatable, and inexpensive geographic information system (GIS approach to predict aquatic macroinvertebrate family richness using the landscape attributes stream gradient, riparian forest cover, and water quality. Stream segments in the Allegheny River basin were classified into eight habitat classes using these three landscape attributes. Biological databases linking macroinvertebrate families with habitat classes were developed using life habits, feeding guilds, and water quality preferences and tolerances for each family. The biological databases provided a link between fauna and habitat enabling estimation of family composition in each habitat class and hence richness predictions for each stream segment. No difference was detected between field collected and modeled predictions of macroinvertebrate families in a paired t-test. Further, predicted stream gradient, riparian forest cover, and total phosphorus, total nitrogen, and suspended sediment classifications matched observed classifications much more often than by chance alone. High gradient streams with forested riparian zones and good water quality were predicted to have the greatest macroinvertebrate family richness and changes in water quality were predicted to have the greatest impact on richness. Our findings indicate that our model can provide meaningful landscape scale macroinvertebrate family richness predictions from widely available data for use in focusing conservation planning efforts.

  6. Testing prototypes of novel radiator for LHCb-RICH

    CERN Document Server

    Saini, Divya

    2017-01-01

    The LHCb experiment at CERN aims to look for signals for physics beyond the standard model in particle physics. The data from Ring Imaging Cherenkov detector (RICH) in LHCb are used to identify the hadronic particles that are produced in proton-proton collisions in different momentum ranges. The particle identification performance of the current detector in the 1-10 GeV/c range needs a significant improvement. For this an R&D project to use a new type of radiator using photonic crystals is underway. In a laboratory at CERN, prototypes of crystals will be exposed to charged particles from a source and the Cherenkov photons created will be detected using multianode photomultiplier tubes (MaPMTs). The data collected will be compared with expectations from optical simulations. These simulations use the solutions of Maxwell’s equations based on the quantum mechanical properties of the crystals. The MaPMTs and the optical components outside the crystals are simulated using GEANT4 and analysis involve using t...

  7. Geomorphic controls on elevational gradients of species richness.

    Science.gov (United States)

    Bertuzzo, Enrico; Carrara, Francesco; Mari, Lorenzo; Altermatt, Florian; Rodriguez-Iturbe, Ignacio; Rinaldo, Andrea

    2016-02-16

    Elevational gradients of biodiversity have been widely investigated, and yet a clear interpretation of the biotic and abiotic factors that determine how species richness varies with elevation is still elusive. In mountainous landscapes, habitats at different elevations are characterized by different areal extent and connectivity properties, key drivers of biodiversity, as predicted by metacommunity theory. However, most previous studies directly correlated species richness to elevational gradients of potential drivers, thus neglecting the interplay between such gradients and the environmental matrix. Here, we investigate the role of geomorphology in shaping patterns of species richness. We develop a spatially explicit zero-sum metacommunity model where species have an elevation-dependent fitness and otherwise neutral traits. Results show that ecological dynamics over complex terrains lead to the null expectation of a hump-shaped elevational gradient of species richness, a pattern widely observed empirically. Local species richness is found to be related to the landscape elevational connectivity, as quantified by a newly proposed metric that applies tools of complex network theory to measure the closeness of a site to others with similar habitat. Our theoretical results suggest clear geomorphic controls on elevational gradients of species richness and support the use of the landscape elevational connectivity as a null model for the analysis of the distribution of biodiversity.

  8. Environmental heterogeneity–species richness relationships from a global perspective

    Directory of Open Access Journals (Sweden)

    Anke Stein

    2016-01-01

    Full Text Available Spatial environmental heterogeneity (EH is considered one of the most important factors promoting species richness, but no general consent about the EH–richness relationship exists so far. This is because research methods and study settings vary widely, and because non-significant and negative associations have also been reported. My thesis provides a comprehensive review of the different measurements and terminologies of EH used in the literature, and presents strong quantitative evidence of a generally positive relationship between biotic and abiotic EH and species richness of terrestrial plants and animals from landscape to global extents. In a meta-analysis and a subsequent case study comparing multiple EH measures and their association with mammal species richness worldwide, I furthermore reveal that the outcome of EH–richness studies depends strongly on study design, including both the EH measure chosen and spatial scale. My research contributes to a better understanding of the EH–richness relationship, while identifying future research needs.

  9. IMPROVEMENT OF THE RICHNESS ESTIMATES OF maxBCG CLUSTERS

    International Nuclear Information System (INIS)

    Rozo, Eduardo; Rykoff, Eli S.; Koester, Benjamin P.; Hansen, Sarah; Becker, Matthew; Bleem, Lindsey; McKay, Timothy; Hao Jiangang; Evrard, August; Wechsler, Risa H.; Sheldon, Erin; Johnston, David; Annis, James; Scranton, Ryan

    2009-01-01

    Minimizing the scatter between cluster mass and accessible observables is an important goal for cluster cosmology. In this work, we introduce a new matched filter richness estimator, and test its performance using the maxBCG cluster catalog. Our new estimator significantly reduces the variance in the L X -richness relation, from σ lnLx 2 = (0.86±0.02) 2 to σ lnLx 2 = (0.69±0.02) 2 . Relative to the maxBCG richness estimate, it also removes the strong redshift dependence of the L X -richness scaling relations, and is significantly more robust to photometric and redshift errors. These improvements are largely due to the better treatment of galaxy color data. We also demonstrate the scatter in the L X -richness relation depends on the aperture used to estimate cluster richness, and introduce a novel approach for optimizing said aperture which can easily be generalized to other mass tracers.

  10. Annotating images by harnessing worldwide user-tagged photos

    NARCIS (Netherlands)

    Li, X.; Snoek, C.G.M.; Worring, M.

    2009-01-01

    Automatic image tagging is important yet challenging due to the semantic gap and the lack of learning examples to model a tag's visual diversity. Meanwhile, social user tagging is creating rich multimedia content on the Web. In this paper, we propose to combine the two tagging approaches in a

  11. In Vivo Imaging of Molecularly Targeted Phage

    Directory of Open Access Journals (Sweden)

    Kimberly A. Kelly

    2006-12-01

    Full Text Available Rapid identification of in vivo affinity ligands would have far-reaching applications for imaging specific molecular targets, in vivo systems imaging, and medical use. We have developed a high-throughput method for identifying and optimizing ligands to map and image biologic targets of interest in vivo. We directly labeled viable phage clones with far-red fluorochromes and comparatively imaged them in vivo by multichannel fluorescence ratio imaging. Using Secreted Protein Acidic and Rich in Cysteine (osteonectin and vascular cell adhesion molecule-1 as model targets, we show that: 1 fluorescently labeled phage retains target specificity on labeling; 2 in vivo distribution can be quantitated (detection thresholds of ~ 300 phage/mm3 tissue throughout the entire depth of the tumor using fluorescent tomographic imaging; and 3 fluorescently labeled phage itself can serve as a replenishable molecular imaging agent. The described method should find widespread application in the rapid in vivo discovery and validation of affinity ligands and, importantly, in the use of fluorochrome-labeled phage clones as in vivo imaging agents.

  12. Origin of the latitudinal richness gradient

    DEFF Research Database (Denmark)

    Engemann, Kristine; Sandel, Brody Steven; Enquist, Brian J.

    2015-01-01

    Spatial variation in richness patterns must be due to variation in rates of speciation, extinction, immigration and emigration. Hotspots of diversity can occur either because they are hotspots of speciation (cradles) or cold spots of extinction (museums) – two major hypotheses that make contrasting...... predictions for the phylogenetic structure of communities. We test these hypotheses by comparing centers of species richness and phylogenetic clustering for vascular plants in the New World. Range maps for 88,417 plant species were extracted from the Botanical Information and Ecology Network (BIEN) database...... and combined with the BIEN mega phylogeny of >80,000 species. We calculated the Phylogenetic Diversity Index (PDI) and Net Relatedness Index (NRI) for each cell in a 100×100 km grid using a new computationally efficient algorithm. Species richness patterns were compared to patterns of PDI and NRI. We found...

  13. The CBM RICH project

    Energy Technology Data Exchange (ETDEWEB)

    Adamczewski-Musch, J. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Akishin, P. [Laboratory of Information Technologies, Joint Institute for Nuclear research (JINR-LIT), Dubna (Russian Federation); Becker, K.-H. [Department of Physics, University of Wuppertal, D-42097 Wuppertal (Germany); Belogurov, S. [SSC RF ITEP, 117218 Moscow (Russian Federation); Bendarouach, J. [Institute of Physics II and Institute of Applied Physics, Justus Liebig University Giessen, D-35392 Giessen (Germany); Boldyreva, N. [National Research Centre “Kurchatov Institute” B.P. Konstantinov Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Chernogorov, A. [SSC RF ITEP, 117218 Moscow (Russian Federation); Deveaux, C. [Institute of Physics II and Institute of Applied Physics, Justus Liebig University Giessen, D-35392 Giessen (Germany); Dobyrn, V. [National Research Centre “Kurchatov Institute” B.P. Konstantinov Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Dürr, M. [Institute of Physics II and Institute of Applied Physics, Justus Liebig University Giessen, D-35392 Giessen (Germany); Eschke, J. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Förtsch, J. [Department of Physics, University of Wuppertal, D-42097 Wuppertal (Germany); Heep, J.; Höhne, C. [Institute of Physics II and Institute of Applied Physics, Justus Liebig University Giessen, D-35392 Giessen (Germany); Kampert, K.-H. [Department of Physics, University of Wuppertal, D-42097 Wuppertal (Germany); and others

    2017-02-11

    The CBM RICH detector is an integral component of the future CBM experiment at FAIR, providing efficient electron identification and pion suppression necessary for the measurement of rare dileptonic probes in heavy ion collisions. The RICH design is based on CO{sub 2} gas as radiator, a segmented spherical glass focussing mirror with Al+MgF{sub 2} reflective coating, and Multianode Photomultipliers for efficient Cherenkov photon detection. Hamamatsu H12700 MAPMTs have recently been selected as photon sensors, following an extensive sensor evaluation, including irradiation tests to ensure sufficient radiation hardness of the MAPMTs. A brief overview of the detector design and concept is given, results on the radiation hardness of the photon sensors are shown, and the development of a FPGA-TDC based readout chain is discussed.

  14. Silica aerogel radiator for use in the A-RICH system utilized in the Belle II experiment

    Science.gov (United States)

    Tabata, Makoto; Adachi, Ichiro; Hamada, Nao; Hara, Koji; Iijima, Toru; Iwata, Shuichi; Kakuno, Hidekazu; Kawai, Hideyuki; Korpar, Samo; Križan, Peter; Kumita, Tetsuro; Nishida, Shohei; Ogawa, Satoru; Pestotnik, Rok; Šantelj, Luka; Seljak, Andrej; Sumiyoshi, Takayuki; Tahirović, Elvedin; Yoshida, Keisuke; Yusa, Yosuke

    2014-12-01

    This paper presents recent progress in the development and mass production of large-area hydrophobic silica aerogels for use as radiators in the aerogel-based ring-imaging Cherenkov (A-RICH) counter, which will be installed in the forward end cap of the Belle II detector. The proximity-focusing A-RICH system is especially designed to identify charged kaons and pions. The refractive index of the installed aerogel Cherenkov radiators is approximately 1.05, and we aim for a separation capability exceeding 4σ at momenta up to 4 GeV/c. Large-area aerogel tiles (over 18×18×2 cm3) were first fabricated in test productions by pin drying in addition to conventional methods. We proposed to fill the large end-cap region (area 3.5 m2) with 124 water-jet-trimmed fan-shaped dual-layer-focusing aerogel combinations of different refractive indices (1.045 and 1.055). Guided by the test production results, we decided to manufacture aerogels by the conventional method and are currently proceeding with mass production. In an electron beam test undertaken at the DESY, we confirmed that the K/π separation capability of a prototype A-RICH counter exceeded 4σ at 4 GeV/c.

  15. LHCb : Behaviour of Multi-anode Photomultipliers in Magnetic Fields for the LHCb RICH Upgrde

    CERN Multimedia

    Gambetta, Silvia

    2015-01-01

    A key feature of the LHCb upgrade, scheduled for 2019, is to remove the first level trigger and its data reduction from 40MHz to 1MHz, which is implemented in the on-detector readout electronics. The consequence for the LHCb Ring Imaging Cherenkov (RICH) detectors is that the Hybrid Photon Detectors need to be replaced as the readout chip is inside the detector vacuum. The baseline for replacement are Multianode Photomultiplier tubes (MaPMT) and new readout electronics. The MaPMTs will be located in the fringe field of the LHCb dipole magnet with residual fields up to 25 G. Therefore, their behaviour in magnetic fields is critical. Here we report about studies of the Hamamatsu models R11265 and H12700 in a magnetic field in an effort to qualify them for use in the LHCb RICH upgrade. Comparisons to the known model R7600 are also made. Measurements of the collection efficiency and gain were performed for all three space directions as a function of the magnetic field strength. In addition to measurements with ba...

  16. Testing the Relationships between Diversification, Species Richness, and Trait Evolution.

    Science.gov (United States)

    Kozak, Kenneth H; Wiens, John J

    2016-11-01

    Understanding which traits drive species diversification is essential for macroevolutionary studies and to understand patterns of species richness among clades. An important tool for testing if traits influence diversification is to estimate rates of net diversification for each clade, and then test for a relationship between traits and diversification rates among clades. However, this general approach has become very controversial. Numerous papers have now stated that it is inappropriate to analyze net diversification rates in groups in which clade richness is not positively correlated with clade age. Similarly, some have stated that variation in net diversification rates does not explain variation in species richness patterns among clades across the Tree of Life. Some authors have also suggested that strong correlations between richness and diversification rates are a statistical artifact and effectively inevitable. If this latter point is true, then correlations between richness and diversification rates would be uninformative (or even misleading) for identifying how much variation in species richness among clades is explained by variation in net diversification rates. Here, we use simulations (based on empirical data for plethodontid salamanders) to address three main questions. First, how is variation in net diversification rates among clades related to the relationship between clade age and species richness? Second, how accurate are these net diversification rate estimators, and does the age-richness relationship have any relevance to their accuracy? Third, is a relationship between species richness and diversification rates an inevitable, statistical artifact? Our simulations show that strong, positive age-richness relationships arise when diversification rates are invariant among clades, whereas realistic variation in diversification rates among clades frequently disrupts this relationship. Thus, a significant age-richness relationship should not be a

  17. Hydrophobically modified polyelectrolytes : synthesis, properties and interactions with surfactants

    NARCIS (Netherlands)

    Nieuwkerk, A.C.

    1998-01-01

    Hydrophobically modified polyelectrolytes can form micelle-like aggregates, so-called microdomains, in aqueous solution. The hydrophobic side chains constitute the apolar inner part of these microdomains and the hydrophilic groups on the polyelectrolyte backbone are at the surface of the

  18. Cardiovascular molecular imaging of apoptosis

    International Nuclear Information System (INIS)

    Wolters, S.L.; Reutelingsperger, C.P.M.; Corsten, M.F.; Hofstra, L.; Narula, J.

    2007-01-01

    Molecular imaging strives to visualise processes at the molecular and cellular level in vivo. Understanding these processes supports diagnosis and evaluation of therapeutic efficacy on an individual basis and thereby makes personalised medicine possible. Apoptosis is a well-organised mode of cell suicide that plays a role in cardiovascular diseases (CVD). Apoptosis is associated with loss of cardiomyocytes following myocardial infarction, atherosclerotic plaque instability, congestive heart failure and allograft rejection of the transplanted heart. Thus, apoptosis constitutes an attractive target for molecular imaging of CVD. Our current knowledge about the molecular players and mechanisms underlying apoptosis offers a rich palette of potential molecular targets for molecular imaging. However, only a few have been successfully developed so far. This review highlights aspects of the molecular machinery and biochemistry of apoptosis relevant to the development of molecular imaging probes. It surveys the role of apoptosis in four major areas of CVD and portrays the importance and future perspectives of apoptosis imaging. The annexin A5 imaging protocol is emphasised since it is the most advanced protocol to measure apoptosis in both preclinical and clinical studies. (orig.)

  19. Cardiovascular molecular imaging of apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Wolters, S.L.; Reutelingsperger, C.P.M. [Maastricht University, Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht (Netherlands); Corsten, M.F.; Hofstra, L. [Maastricht University, Department of Cardiology, Cardiovascular Research Institute Maastricht, P.O. Box 616, Maastricht (Netherlands); Narula, J. [University of California Irvine, Department of Cardiology, Irvine (United States)

    2007-06-15

    Molecular imaging strives to visualise processes at the molecular and cellular level in vivo. Understanding these processes supports diagnosis and evaluation of therapeutic efficacy on an individual basis and thereby makes personalised medicine possible. Apoptosis is a well-organised mode of cell suicide that plays a role in cardiovascular diseases (CVD). Apoptosis is associated with loss of cardiomyocytes following myocardial infarction, atherosclerotic plaque instability, congestive heart failure and allograft rejection of the transplanted heart. Thus, apoptosis constitutes an attractive target for molecular imaging of CVD. Our current knowledge about the molecular players and mechanisms underlying apoptosis offers a rich palette of potential molecular targets for molecular imaging. However, only a few have been successfully developed so far. This review highlights aspects of the molecular machinery and biochemistry of apoptosis relevant to the development of molecular imaging probes. It surveys the role of apoptosis in four major areas of CVD and portrays the importance and future perspectives of apoptosis imaging. The annexin A5 imaging protocol is emphasised since it is the most advanced protocol to measure apoptosis in both preclinical and clinical studies. (orig.)

  20. THE REACH AND RICHNESS OF WIKINOMICS: IS THE FREE WEB-BASED ENCYCLOPEDIA WIKIPEDIA ONLY FOR RICH COUNTRIES?

    DEFF Research Database (Denmark)

    Rask, Morten

    2007-01-01

    In this article, a model of the patterns of correlation in Wikipedia, reach and richness, lays the foundation for studying whether the free Web-based encyclopedia Wikipedia is only for developed countries. Based on data from 12 different Wikipedia language editions, the author finds that the cent......In this article, a model of the patterns of correlation in Wikipedia, reach and richness, lays the foundation for studying whether the free Web-based encyclopedia Wikipedia is only for developed countries. Based on data from 12 different Wikipedia language editions, the author finds...... that the central structural effect is on the level of human development in the current country. In other words, Wikipedia is in general more for rich countries than for less developed countries. It is suggested that policy makers make investments in increasing the general level of literacy, education, and standard...

  1. The Mean and Scatter of the Velocity Dispersion-Optical Richness Relation for MaxBCG Galaxy Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Becker, M.R.; McKay, T.A.; /Michigan U.; Koester, B.; /Chicago U., Astron. Astrophys. Ctr.; Wechsler, R.H.; /KIPAC, Menlo Park /SLAC /Stanford U., Phys. Dept.; Rozo, E.; /Ohio State U.; Evrard, A.; /Michigan U. /Michigan U., MCTP; Johnston, D.; /Caltech, JPL; Sheldon, E.; /New York U.; Annis, J.; /Fermilab; Lau, E.; /Chicago U., Astron. Astrophys. Ctr.; Nichol, R.; /Portsmouth U., ICG; Miller, C.; /Michigan U.

    2007-06-05

    The distribution of galaxies in position and velocity around the centers of galaxy clusters encodes important information about cluster mass and structure. Using the maxBCG galaxy cluster catalog identified from imaging data obtained in the Sloan Digital Sky Survey, we study the BCG--galaxy velocity correlation function. By modeling its non-Gaussianity, we measure the mean and scatter in velocity dispersion at fixed richness. The mean velocity dispersion increases from 202 {+-} 10 km s{sup -1} for small groups to more than 854 {+-} 102 km s{sup -1} for large clusters. We show the scatter to be at most 40.5{+-}3.5%, declining to 14.9{+-}9.4% in the richest bins. We test our methods in the C4 cluster catalog, a spectroscopic cluster catalog produced from the Sloan Digital Sky Survey DR2 spectroscopic sample, and in mock galaxy catalogs constructed from N-body simulations. Our methods are robust, measuring the scatter to well within one-sigma of the true value, and the mean to within 10%, in the mock catalogs. By convolving the scatter in velocity dispersion at fixed richness with the observed richness space density function, we measure the velocity dispersion function of the maxBCG galaxy clusters. Although velocity dispersion and richness do not form a true mass--observable relation, the relationship between velocity dispersion and mass is theoretically well characterized and has low scatter. Thus our results provide a key link between theory and observations up to the velocity bias between dark matter and galaxies.

  2. arXiv The Future of RICH Detectors through the Light of the LHCb RICH

    CERN Document Server

    D'Ambrosio, C.; Easo, S.; Petrolini, A.; Ullaland, O.

    2017-12-21

    The limitations in performance of the present RICH system in the LHCb experiment are given by the natural chromatic dispersion of the gaseous Cherenkov radiator, the aberrations of the optical system and the pixel size of the photon detectors. Moreover, the overall PID performance can be affected by high detector occupancy as the pattern recognition becomes more difficult with high particle multiplicities. This paper shows a way to improve performance by systematically addressing each of the previously mentioned limitations. These ideas are applied in the present and future upgrade phases of the LHCb experiment. Although applied to specific circumstances, they are used as a paradigm on what is achievable in the development and realisation of high precision RICH detectors.

  3. Partitioning sources of variation in vertebrate species richness

    Science.gov (United States)

    Boone, R.B.; Krohn, W.B.

    2000-01-01

    Aim: To explore biogeographic patterns of terrestrial vertebrates in Maine, USA using techniques that would describe local and spatial correlations with the environment. Location: Maine, USA. Methods: We delineated the ranges within Maine (86,156 km2) of 275 species using literature and expert review. Ranges were combined into species richness maps, and compared to geomorphology, climate, and woody plant distributions. Methods were adapted that compared richness of all vertebrate classes to each environmental correlate, rather than assessing a single explanatory theory. We partitioned variation in species richness into components using tree and multiple linear regression. Methods were used that allowed for useful comparisons between tree and linear regression results. For both methods we partitioned variation into broad-scale (spatially autocorrelated) and fine-scale (spatially uncorrelated) explained and unexplained components. By partitioning variance, and using both tree and linear regression in analyses, we explored the degree of variation in species richness for each vertebrate group that Could be explained by the relative contribution of each environmental variable. Results: In tree regression, climate variation explained richness better (92% of mean deviance explained for all species) than woody plant variation (87%) and geomorphology (86%). Reptiles were highly correlated with environmental variation (93%), followed by mammals, amphibians, and birds (each with 84-82% deviance explained). In multiple linear regression, climate was most closely associated with total vertebrate richness (78%), followed by woody plants (67%) and geomorphology (56%). Again, reptiles were closely correlated with the environment (95%), followed by mammals (73%), amphibians (63%) and birds (57%). Main conclusions: Comparing variation explained using tree and multiple linear regression quantified the importance of nonlinear relationships and local interactions between species

  4. Driving into the future: how imaging technology is shaping the future of cars

    Science.gov (United States)

    Zhang, Buyue

    2015-03-01

    Fueled by the development of advanced driver assistance system (ADAS), autonomous vehicles, and the proliferation of cameras and sensors, automotive is becoming a rich new domain for innovations in imaging technology. This paper presents an overview of ADAS, the important imaging and computer vision problems to solve for automotive, and examples of how some of these problems are solved, through which we highlight the challenges and opportunities in the automotive imaging space.

  5. Imaging appearances of cholesterol pneumonia

    International Nuclear Information System (INIS)

    Miao Yanwei; Zhang Jingwen; Wu Jianlin; Zhou Yong; Li Mingwu; Lei Zhen; Shi Lifu

    2006-01-01

    Objection: To analyze the imaging appearances of cholesterol pneumonia. Methods We retrospectively analyzed the X-ray and CT findings of 3 patients with cholesterol pneumonia confirmed pathologically and reviewed correlative literature. Results: Lesions similar to mass were found in X-ray and CT imaging of three cases. Two of them appeared cavity with fluid-level and one showed multiple ring enhancement after CT contrast. The course of disease was very. long and it had no respond to antibiotic therapy. Amounts of foam cells rich in cholesterol crystal were detected in pathological examination. Conclusions: Cholesterol pneumonia is a rare chronic pulmonary idiopathic disease, and the radiological findings can do some help to its diagnosis. (authors)

  6. A view on sphingolipids and disease.

    Science.gov (United States)

    Kolter, Thomas

    2011-09-01

    Sphingolipid and glycosphingolipid levels and expression of sphingolipid metabolizing enzymes are altered in a variety of diseases or in response to drug treatment. Inherited defects of enzymes and other proteins required for the lysosomal degradation of these lipids lead to human sphingolipidoses. Also genetic defects that affect sphingolipid biosynthesis are known. Although the molecular details are often far from clear, (glyco)sphingolipids have been implicated to play a role in atherosclerosis, insulin resistance, cancer, and infections by pathogens. More general aspects of selected diseases are discussed. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Imaging the trigeminal nerve

    International Nuclear Information System (INIS)

    Borges, Alexandra; Casselman, Jan

    2010-01-01

    Of all cranial nerves, the trigeminal nerve is the largest and the most widely distributed in the supra-hyoid neck. It provides sensory input from the face and motor innervation to the muscles of mastication. In order to adequately image the full course of the trigeminal nerve and its main branches a detailed knowledge of neuroanatomy and imaging technique is required. Although the main trunk of the trigeminal nerve is consistently seen on conventional brain studies, high-resolution tailored imaging is mandatory to depict smaller nerve branches and subtle pathologic processes. Increasing developments in imaging technique made possible isotropic sub-milimetric images and curved reconstructions of cranial nerves and their branches and led to an increasing recognition of symptomatic trigeminal neuropathies. Whereas MRI has a higher diagnostic yield in patients with trigeminal neuropathy, CT is still required to demonstrate the bony anatomy of the skull base and is the modality of choice in the context of traumatic injury to the nerve. Imaging of the trigeminal nerve is particularly cumbersome as its long course from the brainstem nuclei to the peripheral branches and its rich anastomotic network impede, in most cases, a topographic approach. Therefore, except in cases of classic trigeminal neuralgia, in which imaging studies can be tailored to the root entry zone, the full course of the trigeminal nerve has to be imaged. This article provides an update in the most recent advances on MR imaging technique and a segmental imaging approach to the most common pathologic processes affecting the trigeminal nerve.

  8. Imaging the trigeminal nerve

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [Radiology Department, Instituto Portugues de Oncologia Francisco Gentil, Centro de Lisboa, Rua Prof. Lima Basto, 1093, Lisboa (Portugal)], E-mail: borgalexandra@gmail.com; Casselman, Jan [Department of Radiology, A. Z. St Jan Brugge and A. Z. St Augustinus Antwerpen Hospitals (Belgium)

    2010-05-15

    Of all cranial nerves, the trigeminal nerve is the largest and the most widely distributed in the supra-hyoid neck. It provides sensory input from the face and motor innervation to the muscles of mastication. In order to adequately image the full course of the trigeminal nerve and its main branches a detailed knowledge of neuroanatomy and imaging technique is required. Although the main trunk of the trigeminal nerve is consistently seen on conventional brain studies, high-resolution tailored imaging is mandatory to depict smaller nerve branches and subtle pathologic processes. Increasing developments in imaging technique made possible isotropic sub-milimetric images and curved reconstructions of cranial nerves and their branches and led to an increasing recognition of symptomatic trigeminal neuropathies. Whereas MRI has a higher diagnostic yield in patients with trigeminal neuropathy, CT is still required to demonstrate the bony anatomy of the skull base and is the modality of choice in the context of traumatic injury to the nerve. Imaging of the trigeminal nerve is particularly cumbersome as its long course from the brainstem nuclei to the peripheral branches and its rich anastomotic network impede, in most cases, a topographic approach. Therefore, except in cases of classic trigeminal neuralgia, in which imaging studies can be tailored to the root entry zone, the full course of the trigeminal nerve has to be imaged. This article provides an update in the most recent advances on MR imaging technique and a segmental imaging approach to the most common pathologic processes affecting the trigeminal nerve.

  9. The Omega Ring Imaging Cerenkov Detector readout system user's guide

    International Nuclear Information System (INIS)

    Hallewell, G.

    1984-11-01

    The manual describes the electronic readout system of the Ring Imaging Cerenkov Detector at the CERN Omega Spectrometer. The system is described in its configuration of September 1984 after the Rich readout system had been used in two Omega experiments. (U.K.)

  10. Disturbance alters local-regional richness relationships in appalachian forests

    Science.gov (United States)

    Belote, R.T.; Sanders, N.J.; Jones, R.H.

    2009-01-01

    Whether biological diversity within communities is limited by local interactions or regional species pools remains an important question in ecology. In this paper, we investigate how an experimentally applied tree-harvesting disturbance gradient influenced local-regional richness relationships. Plant species richness was measured at three spatial scales (2 ha = regional; 576 m2 and 1 m2 = local) on three occasions (one year pre-disturbance, one year post-disturbance, and 10 years post-disturbance) across five disturbance treatments (uncut control through clearcut) replicated throughout the southern Appalachian Mountains, USA. We investigated whether species richness in 576-m2 plots and 1-m2 subplots depended on species richness in 2-ha experimental units and whether this relationship changed through time before and after canopy disturbance. We found that, before disturbance, the relationship between local and regional richness was weak or nonexistent. One year after disturbance local richness was a positive function of regional richness, because local sites were colonized from the regional species pool. Ten years after disturbance, the positive relationship persisted, but the slope had decreased by half. These results suggest that disturbance can set the stage for strong influences of regional species pools on local community assembly in temperate forests. However, as time since disturbance increases, local controls on community assembly decouple the relationships between regional and local diversity. ?? 2009 by the Ecological Society of America.

  11. Synthesis and study of neutron-rich nuclides

    International Nuclear Information System (INIS)

    Luo, Y.X.

    1995-01-01

    During the past few years our understanding of the decay properties and nuclear structure has been extended in a systematic fashion for the neutron-rich nuclei. This review will discuss the impressive progress in the studies of the exotic decay properties and nuclear structure of n-rich nuclei. Their astrophysical implications will also be outlined. ((orig.))

  12. Radiopharmaceuticals for neurotransmitter imaging

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Seung Jun [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Neurotransmitter imaging with radiopharmaceuticals plays major role for understanding of neurological and psychiatric disorders such as Parkinson's disease and depression. Radiopharmaceuticals for neurotransmitter imaging can be divided to dopamine transporter imaging radiopharmaceuticals and serotonin transporter imaging radiopharmaceuticals. Many kinds of new dopamine transporter imaging radiopharmaceuticals has a tropane ring and they showed different biological properties according to the substituted functional group on tropane ring. After the first clinical trials with [{sup 123}I] {beta} -CIT, alkyl chain substituent introduced to tropane ring amine to decrease time for imaging acquisition and to increase selectivity. From these results, [{sup 123}I]PE2I, [18F]FE-CNT, [{sup 123}I]FP-CIT and [{sup 18}F]FP-CIT were developed and they showed high uptake on the dopamine transporter rich regions and fast peak uptake equilibrium time within 4 hours after injection. [{sup 11}C]McN 5652 was developed for serotonin transporter imaging but this compound showed slow kinetics and high background radioactivity. To overcome these problems, new diarylsulfide backbone derivatives such as ADAM, ODAM, AFM, and DASB were developed. In these candidates, [{sup 11}C]AFM and [{sup 11}C]DASB showed high binding affinity to serotonin transporter and fast in vivo kinetics. This paper gives an overview of current status on dopamine and serotonin transporter imaging radiopharmaceuticals and the development of new lead compounds as potential radiopharmaceuticals by medicinal chemistry.

  13. Cholesterol depletion of enterocytes. Effect on the Golgi complex and apical membrane trafficking

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Niels-Christiansen, L L; Thorsen, Evy

    2000-01-01

    Intestinal brush border enzymes, including aminopeptidase N and sucrase-isomaltase, are associated with "rafts" (membrane microdomains rich in cholesterol and sphingoglycolipids). To assess the functional role of rafts in the present work, we studied the effect of cholesterol depletion on apical......, the rates of the Golgi-associated complex glycosylation and association with rafts of newly synthesized aminopeptidase N were reduced, and less of the enzyme had reached the brush border membrane after 2 h of labeling. In contrast, the basolateral Na(+)/K(+)-ATPase was neither missorted nor raft......-associated. Our results implicate the Golgi complex/trans-Golgi network in raft formation and suggest a close relationship between this event and apical membrane trafficking....

  14. Relativistic mean field calculations in neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Gangopadhyay, G.; Bhattacharya, Madhubrata [Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700 009 (India); Roy, Subinit [Saha Institute of Nuclear Physics, Block AF, Sector 1, Kolkata- 700 064 (India)

    2014-08-14

    Relativistic mean field calculations have been employed to study neutron rich nuclei. The Lagrange's equations have been solved in the co-ordinate space. The effect of the continuum has been effectively taken into account through the method of resonant continuum. It is found that BCS approximation performs as well as a more involved Relativistic Continuum Hartree Bogoliubov approach. Calculations reveal the possibility of modification of magic numbers in neutron rich nuclei. Calculation for low energy proton scattering cross sections shows that the present approach reproduces the density in very light neutron rich nuclei.

  15. Colors of Alien Worlds from Direct Imaging Exoplanet Missions

    Science.gov (United States)

    Hu, Renyu

    2016-01-01

    Future direct-imaging exoplanet missions such as WFIRST will measure the reflectivity of exoplanets at visible wavelengths. Most of the exoplanets to be observed will be located further away from their parent stars than is Earth from the Sun. These "cold" exoplanets have atmospheric environments conducive for the formation of water and/or ammonia clouds, like Jupiter in the Solar System. I find the mixing ratio of methane and the pressure level of the uppermost cloud deck on these planets can be uniquely determined from their reflection spectra, with moderate spectral resolution, if the cloud deck is between 0.6 and 1.5 bars. The existence of this unique solution is useful for exoplanet direct imaging missions for several reasons. First, the weak bands and strong bands of methane enable the measurement of the methane mixing ratio and the cloud pressure, although an overlying haze layer can bias the estimate of the latter. Second, the cloud pressure, once derived, yields an important constraint on the internal heat flux from the planet, and thus indicating its thermal evolution. Third, water worlds having H2O-dominated atmospheres are likely to have water clouds located higher than the 10-3 bar pressure level, and muted spectral absorption features. These planets would occupy a confined phase space in the color-color diagrams, likely distinguishable from H2-rich giant exoplanets by broadband observations. Therefore, direct-imaging exoplanet missions may offer the capability to broadly distinguish H2-rich giant exoplanets versus H2O-rich super-Earth exoplanets, and to detect ammonia and/or water clouds and methane gas in their atmospheres.

  16. Analysis of the Poisson-Nernst-Planck equation in a ball for modeling the Voltage-Current relation in neurobiological microdomains

    Science.gov (United States)

    Cartailler, J.; Schuss, Z.; Holcman, D.

    2017-01-01

    The electro-diffusion of ions is often described by the Poisson-Nernst-Planck (PNP) equations, which couple nonlinearly the charge concentration and the electric potential. This model is used, among others, to describe the motion of ions in neuronal micro-compartments. It remains at this time an open question how to determine the relaxation and the steady state distribution of voltage when an initial charge of ions is injected into a domain bounded by an impermeable dielectric membrane. The purpose of this paper is to construct an asymptotic approximation to the solution of the stationary PNP equations in a d-dimensional ball (d = 1 , 2 , 3) in the limit of large total charge. In this geometry the PNP system reduces to the Liouville-Gelfand-Bratú (LGB) equation, with the difference that the boundary condition is Neumann, not Dirichlet, and there is a minus sign in the exponent of the exponential term. The entire boundary is impermeable to ions and the electric field satisfies the compatibility condition of Poisson's equation. These differences replace attraction by repulsion in the LGB equation, thus completely changing the solution. We find that the voltage is maximal in the center and decreases toward the boundary. We also find that the potential drop between the center and the surface increases logarithmically in the total number of charges and not linearly, as in classical capacitance theory. This logarithmic singularity is obtained for d = 3 from an asymptotic argument and cannot be derived from the analysis of the phase portrait. These results are used to derive the relation between the outward current and the voltage in a dendritic spine, which is idealized as a dielectric sphere connected smoothly to the nerve axon by a narrow neck. This is a fundamental microdomain involved in neuronal communication. We compute the escape rate of an ion from the steady density in a ball, which models a neuronal spine head, to a small absorbing window in the sphere. We

  17. Candida albicans Targets a Lipid Raft/Dectin-1 Platform to Enter Human Monocytes and Induce Antigen Specific T Cell Responses.

    Directory of Open Access Journals (Sweden)

    Valeria de Turris

    Full Text Available Several pathogens have been described to enter host cells via cholesterol-enriched membrane lipid raft microdomains. We found that disruption of lipid rafts by the cholesterol-extracting agent methyl-β-cyclodextrin or by the cholesterol-binding antifungal drug Amphotericin B strongly impairs the uptake of the fungal pathogen Candida albicans by human monocytes, suggesting a role of raft microdomains in the phagocytosis of the fungus. Time lapse confocal imaging indicated that Dectin-1, the C-type lectin receptor that recognizes Candida albicans cell wall-associated β-glucan, is recruited to lipid rafts upon Candida albicans uptake by monocytes, supporting the notion that lipid rafts act as an entry platform. Interestingly disruption of lipid raft integrity and interference with fungus uptake do not alter cytokine production by monocytes in response to Candida albicans but drastically dampen fungus specific T cell response. In conclusion, these data suggest that monocyte lipid rafts play a crucial role in the innate and adaptive immune responses to Candida albicans in humans and highlight a new and unexpected immunomodulatory function of the antifungal drug Amphotericin B.

  18. Differences in species richness patterns between unicellular and multicellular organisms.

    Science.gov (United States)

    Hillebrand, Helmut; Watermann, Frank; Karez, Rolf; Berninger, Ulrike-G

    2001-01-01

    For unicellular organisms, a lack of effects of local species richness on ecosystem function has been proposed due to their locally high species richness and their ubiquitous distribution. High dispersal ability and high individual numbers may enable unicellular taxa to occur everywhere. Using our own and published data sets on uni- and multicellular organisms, we conducted thorough statistical analyses to test whether (1) unicellular taxa show higher relative local species richness compared to multicellular taxa, (2) unicellular taxa show lower slopes of the species:area relationships and species:individuals relationships, and (3) the species composition of unicellular taxa is less influenced by geographic distance compared to multicellular taxa. We found higher local species richness compared to the global species pool for unicellular organisms than for metazoan taxa. The difference was significant if global species richness was conservatively estimated but not if extrapolated, and therefore higher richness estimates were used. Both microalgae and protozoans showed lower slopes between species richness and sample size (area or individuals) compared to macrozoobenthos, also indicating higher local species richness for unicellular taxa. The similarity of species composition of both benthic diatoms and ciliates decreased with increasing geographic distance. This indicated restricted dispersal ability of protists and the absence of ubiquity. However, a steeper slope between similarity and distance was found for polychaetes and corals, suggesting a stronger effect of distance on the dispersal of metazoans compared to unicellular taxa. In conclusion, we found partly different species richness patterns among uni- and multicellular eukaryotes, but no strict ubiquity of unicellular taxa. Therefore, the effect of local unicellular species richness on ecosystem function has to be reanalyzed. Macroecological patterns suggested for multicellular organisms may differ in

  19. Catheter design optimization for practical intravascular photoacoustic imaging (IVPA) of vulnerable plaques

    Science.gov (United States)

    Iskander-Rizk, Sophinese; Wu, Min; Springeling, Geert; Mastik, Frits; Beurskens, Robert H. S. H.; van der Steen, Antonius F. W.; van Soest, Gijs

    2018-02-01

    Intravascular photoacoustic/ultrasound imaging (IVPA/US) can image the structure and composition of atherosclerotic lesions identifying lipid-rich plaques ex vivo and in vivo. In the literature, multiple IVPA/US catheter designs were presented and validated both in ex-vivo models and preclinical in-vivo situations. Since the catheter is a critical component of the imaging system, we discuss here a catheter design oriented to imaging plaque in a realistic and translatable setting. We present a catheter optimized for light delivery, manageable flush parameters and robustness with reduced mechanical damage risks at the laser/catheter joint interface. We also show capability of imaging within sheath and in water medium.

  20. Autoimmune encephalitis associated with voltage-gated potassium channels-complex and leucine-rich glioma-inactivated 1 antibodies - a national cohort study

    DEFF Research Database (Denmark)

    Celicanin, M; Blaabjerg, Morten; Maersk-Moller, C

    2017-01-01

    BACKGROUND AND PURPOSE: The aim of this study was to describe clinical and paraclinical characteristics of all Danish patients who tested positive for anti-voltage-gated potassium channels (VGKC)-complex, anti-leucine-rich glioma-inactivated 1 (LGI1) and anti-contactin-associated protein-2...... antibodies in the serum/cerebrospinal fluid between 2009 and 2013 with follow-up interviews in 2015 and 2016. METHODS: We evaluated antibody status, symptoms leading to testing, course of disease, suspected diagnosis and time of admission as well as diagnosis and treatment. All magnetic resonance imaging......-Barré syndrome, Creutzfeldt-Jakob disease, neuromyotonia and anti-N-methyl-D-aspartate receptor encephalitis. Magnetic resonance imaging abnormalities were demonstrated in 69% of the LGI1-positive patients. Two patients with normal magnetic resonance imaging demonstrated temporal lobe hypermetabolism using (18...

  1. CCR5 internalisation and signalling have different dependence on membrane lipid raft integrity.

    Science.gov (United States)

    Cardaba, Clara Moyano; Kerr, Jason S; Mueller, Anja

    2008-09-01

    The chemokine receptor, CCR5, acts as a co-receptor for human immunodeficiency virus entry into cells. CCR5 has been shown to be targeted to cholesterol- and sphingolipid-rich membrane microdomains termed lipid rafts or caveolae. Cholesterol is essential for CCL4 binding to CCR5 and for keeping the conformational integrity of the receptor. Filipin treatment leads to loss of caveolin-1 from the membrane and therefore to a collapse of the caveolae. We have found here that sequestration of membrane cholesterol with filipin did not affect receptor signalling, however a loss of ligand-induced internalisation of CCR5 was observed. Cholesterol extraction with methyl-beta-cyclodextrin (MCD) reduced signalling through CCR5 as measured by release of intracellular Ca(2+) and completely abolished the inhibition of forskolin-stimulated cAMP accumulation with no effect on internalisation. Pertussis toxin (PTX) treatment inhibited the intracellular release of calcium that is transduced via Galphai G-proteins. Depletion of cholesterol destroyed microdomains in the membrane and switched CCR5/G-protein coupling to a PTX-independent G-protein. We conclude that cholesterol in the membrane is essential for CCR5 signalling via the Galphai G-protein subunit, and that integrity of lipid rafts is not essential for effective CCR5 internalisation however it is crucial for proper CCR5 signal transduction via Galphai G-proteins.

  2. Butterfly Species Richness in Selected West Albertine Rift Forests

    Directory of Open Access Journals (Sweden)

    Patrice Kasangaki

    2012-01-01

    Full Text Available The butterfly species richness of 17 forests located in the western arm of the Albertine Rift in Uganda was compared using cluster analysis and principal components analysis (PCA to assess similarities among the forests. The objective was to compare the butterfly species richness of the forests. A total of 630 butterfly species were collected in 5 main families. The different species fell into 7 ecological groupings with the closed forest group having the most species and the swamp/wetland group with the fewest number of species. Three clusters were obtained. The first cluster had forests characterized by relatively high altitude and low species richness despite the big area in the case of Rwenzori and being close to the supposed Pleistocene refugium. The second cluster had forests far away from the supposed refugium except Kisangi and moderate species richness with small areas, whereas the third cluster had those forests that were more disturbed, high species richness, and low altitudinal levels with big areas.

  3. LHCB : The upgraded LHCb RICH detector: status and perspectives

    CERN Multimedia

    Cardinale, Roberta

    2015-01-01

    The LHCb experiment is designed to perform high-precision measurements of CP violation and search for New Physics using the enormous flux of beauty and charmed hadrons produced at the Large Hadron Collider (LHC). The two RICH detectors installed in LHCb have performed successfully during the 2010-2012 data taking period. The data from these detectors were essential to most of the physics results published by LHCb. In order to extend its potential for discovery and study of new phenomena it is planned to upgrade the LHCb experiment in 2018 with a 40MHz readout and a much more flexible software-based triggering system. This would increase the readout rate and occupancies for the RICH detectors. The RICH detector will require new photon detectors and modifications of the optics of the upstream RICH detector. Tests of the complete opto-electronic chain have been performed during testbeam sessions in autumn 2014. The status and perspectives of the RICH upgrade project will be presented.

  4. Neutron rich nuclei

    International Nuclear Information System (INIS)

    Foucher, R.

    1979-01-01

    If some β - emitters are particularly interesting to study in light, medium, and heavy nuclei, another (and also) difficult problem is to know systematically the properties of these neutron rich nuclei far from the stability line. A review of some of their characteristics is presented. How far is it possible to be objective in the interpretation of data is questioned and implications are discussed

  5. Ion transport by mitochondria-rich cells in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Ussing, H H; Spring, K R

    1987-01-01

    The optical sectioning video imaging technique was used for measurements of the volume of mitochondria-rich (m.r.) cells of the isolated epithelium of toad skin. Under short-circuit conditions, cell volume decreased by about 14% in response to bilateral exposure to Cl-free (gluconate substitution....... Unilateral exposure to a Cl-free solution did not prevent ouabain-induced cell swelling. It is concluded that m.r. cells have an amiloride-blockable Na conductance in the apical membrane, a ouabain-sensitive Na pump in the basolateral membrane, and a passive Cl permeability in both membranes. From...... the initial rate of ouabain-induced cell volume increase the active Na current carried by a single m.r. cell was estimated to be 9.9 +/- 1.3 pA. Voltage clamping of the preparation in the physiological range of potentials (0 to -100 mV, serosa grounded) resulted in a cell volume increase with a time course...

  6. Adaptive polarization image fusion based on regional energy dynamic weighted average

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yong-qiang; PAN Quan; ZHANG Hong-cai

    2005-01-01

    According to the principle of polarization imaging and the relation between Stokes parameters and the degree of linear polarization, there are much redundant and complementary information in polarized images. Since man-made objects and natural objects can be easily distinguished in images of degree of linear polarization and images of Stokes parameters contain rich detailed information of the scene, the clutters in the images can be removed efficiently while the detailed information can be maintained by combining these images. An algorithm of adaptive polarization image fusion based on regional energy dynamic weighted average is proposed in this paper to combine these images. Through an experiment and simulations,most clutters are removed by this algorithm. The fusion method is used for different light conditions in simulation, and the influence of lighting conditions on the fusion results is analyzed.

  7. The effect of platelet-rich plasma on composite graft survival.

    Science.gov (United States)

    Jeon, Yeo Reum; Kang, Eun Hye; Yang, Chae Eun; Yun, In Sik; Lee, Won Jai; Lew, Dae Hyun

    2014-08-01

    Composite grafts are suitable for facial reconstruction because of good color matching, low donor-site morbidity, acceptable texture, and easy surgical techniques. However, their use is limited to small defects and by unpredictable survival rates. As platelet-rich plasma contains large numbers of growth factors and has been widely used for tissue regeneration, this study aimed to investigate platelet-rich plasma as an adjuvant to enhance composite graft survival. Twenty New Zealand White rabbits were used, and chondrocutaneous composite grafts were applied to their ears. The grafts were then returned to their original positions after rotation to block the original circulation from the base of the graft. Each of the individual ears was assigned randomly into one of two groups: experimental (n=20; platelet-rich plasma group) or control (n=20; control group). The surrounding skin of the composite graft was injected with either 1.0 ml of platelet-rich plasma derived from autologous whole blood in the platelet-rich plasma group or normal saline in the control group. Graft survival, cutaneous blood flow, CD31-stained vessels, and vascular endothelial growth factor protein levels were examined. Twelve days after surgery, graft viability in the platelet-rich plasma group was higher than in the control group. Blood perfusion was also higher in the platelet-rich plasma group. Compared with the control group, the number of CD31 blood vessels and vascular endothelial growth factor expression levels were significantly increased in the platelet-rich plasma group. The authors' results suggest that platelet-rich plasma restores the perfusion of composite grafts by enhancing revascularization and may exert therapeutic effects on the survival of composite grafts.

  8. Test of the CLAS12 RICH large-scale prototype in the direct proximity focusing configuration

    Energy Technology Data Exchange (ETDEWEB)

    Anefalos Pereira, S.; Lucherini, V.; Mirazita, M.; Orlandi, A.; Orecchini, D.; Pisano, S.; Tomassini, S.; Viticchie, A. [Laboratori Nazionali di Frascati, INFN, Frascati (Italy); Baltzell, N.; El Alaoui, A.; Hafidi, K. [Physics Division, Argonne National Laboratory, Argonne, IL (United States); Barion, L.; Contalbrigo, M.; Malaguti, R.; Movsisyan, A.; Pappalardo, L.L.; Squerzanti, S. [INFN, Ferrara (Italy); Benmokhtar, F. [Department of Physics, Duquesne University, Pittsburgh, PA (United States); Brooks, W. [Universidad Tecnica Federico Santa Maria, Valparaiso (Chile); Cisbani, E. [Gruppo Sanita and Istituto Superiore di Sanita, INFN, Rome (Italy); Hoek, M.; Phillips, J. [School of Physics and Astronomy, Kelvin Building, University of Glasgow, Scotland (United Kingdom); Kubarovsky, V. [Thomas Jefferson National Accelerator Facility, Jefferson Laboratory, Newport News, VA (United States); Lagamba, L.; Perrino, R. [INFN, Bari (Italy); Montgomery, R.A. [Laboratori Nazionali di Frascati, INFN, Frascati (Italy); School of Physics and Astronomy, Kelvin Building, University of Glasgow, Scotland (United Kingdom); Musico, P. [INFN, Genova (Italy); Rossi, P. [Laboratori Nazionali di Frascati, INFN, Frascati (Italy); Thomas Jefferson National Accelerator Facility, Jefferson Laboratory, Newport News, VA (United States); Turisini, M. [INFN, Ferrara (Italy); Universidad Tecnica Federico Santa Maria, Valparaiso (Chile)

    2016-02-15

    A large-area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3GeV/c up to 8GeV/c for the CLAS12 experiment at the upgraded 12GeV continuous electron beam accelerator facility of Jefferson Laboratory. The adopted solution foresees a novel hybrid optics design based on aerogel radiator, composite mirrors and highly packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large-angle tracks). We report here the results of the tests of a large-scale prototype of the RICH detector performed with the hadron beam of the CERN T9 experimental hall for the direct detection configuration. The tests demonstrated that the proposed design provides the required pion-to-kaon rejection factor of 1: 500 in the whole momentum range. (orig.)

  9. Lasp-1 regulates podosome function.

    Directory of Open Access Journals (Sweden)

    Miriam Stölting

    Full Text Available Eukaryotic cells form a variety of adhesive structures to connect with their environment and to regulate cell motility. In contrast to classical focal adhesions, podosomes, highly dynamic structures of different cell types, are actively engaged in matrix remodelling and degradation. Podosomes are composed of an actin-rich core region surrounded by a ring-like structure containing signalling molecules, motor proteins as well as cytoskeleton-associated proteins. Lasp-1 is a ubiquitously expressed, actin-binding protein that is known to regulate cytoskeleton architecture and cell migration. This multidomain protein is predominantely present at focal adhesions, however, a second pool of Lasp-1 molecules is also found at lamellipodia and vesicle-like microdomains in the cytosol.In this report, we show that Lasp-1 is a novel component and regulator of podosomes. Immunofluorescence studies reveal a localization of Lasp-1 in the podosome ring structure, where it colocalizes with zyxin and vinculin. Life cell imaging experiments demonstrate that Lasp-1 is recruited in early steps of podosome assembly. A siRNA-mediated Lasp-1 knockdown in human macrophages affects podosome dynamics as well as their matrix degradation capacity. In summary, our data indicate that Lasp-1 is a novel component of podosomes and is involved in the regulation of podosomal function.

  10. Small leucine-rich proteoglycans in the aging skeleton

    DEFF Research Database (Denmark)

    Young, M F; Bi, Y; Ameye, L

    2006-01-01

    Small Leucine-Rich Proteoglyans (SLRPs) are major skeletal extracellular matrix (ECM) components that comprise a family of 13 members containing repeats of a leucine-rich motif. To examine SLRP function, we generated mice deficient in one or more member and analyzed them at the tissue, cell...

  11. Three-dimensional structure and cytokine distribution of platelet-rich fibrin.

    Science.gov (United States)

    Bai, Meng-Yi; Wang, Ching-Wei; Wang, Jyun-Yi; Lin, Ming-Fang; Chan, Wing P

    2017-02-01

    Previous reports have revealed that several cytokines (including platelet-derived growth factor-BB, transforming growth factors-β1 and insulin-like growth factor-1) can enhance the rate of bone formation and synthesis of extracellular matrix in orthopaedics or periodontology. This study aimed to determine the concentration of cytokines within platelet-rich fibrin microstructures and investigate whether there are differences in the different portions of platelet-rich fibrin, which has implications for proper clinical use of platelet-rich fibrin gel. Whole blood was obtained from six New Zealand rabbits (male, 7 to 39 weeks old, weight 2.7-4 kg); it was then centrifuged for preparation of platelet-rich fibrin gels and harvest of plasma. The resultant platelet-rich fibrin gels were used for cytokine determination, histological analyses and scanning electron microscopy. All plasmas obtained were subject to the same cytokine determination assays for the purpose of comparison. Cytokines platelet-derived growth factor-BB and transforming growth factor-β1 formed concentration gradients from high at the red blood cell end of the platelet-rich fibrin gel (p=1.88×10-5) to low at the plasma end (p=0.19). Insulin-like growth factor-1 concentrations were similar at the red blood cell and plasma ends. The porosities of the platelet-rich fibrin samples taken in sequence from the red blood cell end to the plasma end were 6.5% ± 4.9%, 24.8% ± 7.5%, 30.3% ± 8.5%, 41.4% ± 12.3%, and 40.3% ± 11.7%, respectively, showing a gradual decrease in the compactness of the platelet-rich fibrin network. Cytokine concentrations are positively associated with platelet-rich fibrin microstructure and portion in a rabbit model. As platelet-rich fibrin is the main entity currently used in regenerative medicine, assessing cytokine concentration and the most valuable portion of PRF gels is essential and recommended to all physicians.

  12. Three-dimensional structure and cytokine distribution of platelet-rich fibrin

    Directory of Open Access Journals (Sweden)

    Meng-Yi Bai

    Full Text Available OBJECTIVES: Previous reports have revealed that several cytokines (including platelet-derived growth factor-BB, transforming growth factors-β1 and insulin-like growth factor-1 can enhance the rate of bone formation and synthesis of extracellular matrix in orthopaedics or periodontology. This study aimed to determine the concentration of cytokines within platelet-rich fibrin microstructures and investigate whether there are differences in the different portions of platelet-rich fibrin, which has implications for proper clinical use of platelet-rich fibrin gel. METHODS: Whole blood was obtained from six New Zealand rabbits (male, 7 to 39 weeks old, weight 2.7-4 kg; it was then centrifuged for preparation of platelet-rich fibrin gels and harvest of plasma. The resultant platelet-rich fibrin gels were used for cytokine determination, histological analyses and scanning electron microscopy. All plasmas obtained were subject to the same cytokine determination assays for the purpose of comparison. RESULTS: Cytokines platelet-derived growth factor-BB and transforming growth factor-β1 formed concentration gradients from high at the red blood cell end of the platelet-rich fibrin gel (p=1.88×10-5 to low at the plasma end (p=0.19. Insulin-like growth factor-1 concentrations were similar at the red blood cell and plasma ends. The porosities of the platelet-rich fibrin samples taken in sequence from the red blood cell end to the plasma end were 6.5% ± 4.9%, 24.8% ± 7.5%, 30.3% ± 8.5%, 41.4% ± 12.3%, and 40.3% ± 11.7%, respectively, showing a gradual decrease in the compactness of the platelet-rich fibrin network. CONCLUSION: Cytokine concentrations are positively associated with platelet-rich fibrin microstructure and portion in a rabbit model. As platelet-rich fibrin is the main entity currently used in regenerative medicine, assessing cytokine concentration and the most valuable portion of PRF gels is essential and recommended to all physicians.

  13. Investigation of phase separated polyimide blend films containing boron nitride using FTIR imaging

    Science.gov (United States)

    Chae, Boknam; Hong, Deok Gi; Jung, Young Mee; Won, Jong Chan; Lee, Seung Woo

    2018-04-01

    Immiscible aromatic polyimide (PI) blend films and a PI blend film incorporated with thermally conductive boron nitride (BN) were prepared, and their phase separation behaviors were examined by optical microscopy and FTIR imaging. The 2,2‧-bis(trifluoromethyl)benzidine (TFMB)-containing and 4,4‧-thiodianiline (TDA)-containing aromatic PI blend films and a PI blend/BN composite film show two clearly separated regions; one region is the TFMB-rich phase, and the other region is the TDA-rich phase. The introduction of BN induces morphological changes in the immiscible aromatic PI blend film without altering the composition of either domain. In particular, the BN is selectively incorporated into the TDA-rich phase in this study.

  14. Development of a Large Area Advanced Fast RICH Detector for Particle Identification at the Large Hadron Collider Operated with Heavy Ions

    CERN Multimedia

    Piuz, F; Braem, A; Van beelen, J B; Lion, G; Gandi, A

    2002-01-01

    %RD26 %title\\\\ \\\\During the past two years, RD26 groups have focused their activities on the production of CsI-RICH prototypes of large area, up to a square meter, to demonstrate their application in High Energy experiments. Many large CsI-photocathodes (up to 40) were produced following the processing techniques furthermore developped in the collaboration. Taking the Quantum Efficiency (QE) measured at 180 nm as a comparative figure of merit of a CsI-PC. Figure 1 shows the increase of the performance while improvements were successively implemented in the PC processing sequence. Most efficient were the use of substrates made of nickel, the heat treatment and handling of the PCs under inert gas. Actually, three large systems based on CsI-RICH have got approval in the following HEP experiments: HADES at GSI, COMPASS/NA58 at CERN and HMPID/ALICE at LHC implying up to 14 square metres of CsI-PC. In addition, several CsI-RICH detectors have been successfully operated in the Threshold Imaging Detector at NA44 and ...

  15. Reconstruction and calibration strategies for the LHCb RICH detector

    CERN Multimedia

    2006-01-01

    - LHCb particle identification - LHCb ring pattern recognition algorithm requirements - RICH pattern recognition - Cherenkov angle reconstruction online - Online PID - Hough transform - Metropolis- Hastings Markov chains - PID online: physics performances - Rich PID Callibration

  16. In situ fluorescence activation of DNA-silver nanoclusters as a label-free and general strategy for cell nucleus imaging.

    Science.gov (United States)

    Li, Duo; Qiao, Zhenzhen; Yu, Yanru; Tang, Jinlu; He, Xiaoxiao; Shi, Hui; Ye, Xiaosheng; Lei, Yanli; Wang, Kemin

    2018-01-25

    A facile, general and turn-on nucleus imaging strategy was first developed based on in situ fluorescence activation of C-rich dark silver nanoclusters by G-rich telomeres. After a simple incubation without washing, nanoclusters could selectively stain the nucleus with intense red luminescence, which was confirmed using fixed/living cells and several cell lines.

  17. Rapid transitions between defect configurations in a block copolymer melt.

    Science.gov (United States)

    Tsarkova, Larisa; Knoll, Armin; Magerle, Robert

    2006-07-01

    With in situ scanning force microscopy, we image the ordering of cylindrical microdomains in a thin film of a diblock copolymer melt. Tracking the evolution of individual defects reveals elementary steps of defect motion via interfacial undulations and repetitive transitions between distinct defect configurations on a time scale of tens of seconds. The velocity of these transitions suggests a cooperative movement of clusters of chains. The activation energy for the opening/closing of a connection between two cylinders is estimated.

  18. Extended depth of field integral imaging using multi-focus fusion

    Science.gov (United States)

    Piao, Yongri; Zhang, Miao; Wang, Xiaohui; Li, Peihua

    2018-03-01

    In this paper, we propose a new method for depth of field extension in integral imaging by realizing the image fusion method on the multi-focus elemental images. In the proposed method, a camera is translated on a 2D grid to take multi-focus elemental images by sweeping the focus plane across the scene. Simply applying an image fusion method on the elemental images holding rich parallax information does not work effectively because registration accuracy of images is the prerequisite for image fusion. To solve this problem an elemental image generalization method is proposed. The aim of this generalization process is to geometrically align the objects in all elemental images so that the correct regions of multi-focus elemental images can be exacted. The all-in focus elemental images are then generated by fusing the generalized elemental images using the block based fusion method. The experimental results demonstrate that the depth of field of synthetic aperture integral imaging system has been extended by realizing the generation method combined with the image fusion on multi-focus elemental images in synthetic aperture integral imaging system.

  19. Production of conjugated linoleic acid-rich potato chips.

    Science.gov (United States)

    Jain, Vishal P; Proctor, Andrew

    2007-01-01

    Conjugated linoleic acid (CLA) is found primarily in diary and beef products, but the health benefits of CLA can only be realized if they are consumed at much greater levels than a normal healthy dietary intake. We have recently shown that a CLA-rich soy oil can be produced by simple isomerization of linoleic acid in soy oil by photoirradiation. This oil may allow greatly increased dietary CLA without significantly elevating fat intake. The objective of this study was to prepare CLA-rich potato chips by frying in CLA-rich soy oil. Soy oil was photoisomerized in the presence of iodine catalyst with UV/visible light. The irradiated oil was clay processed to remove the residual iodine and this oil was then used to fry potato chips. Oil was extracted from fried chips and analyzed for its CLA content with gas chromatography. A 1-oz serving of CLA-rich potato chips contained approximately 2.4 g CLA as compared to 0.1 g CLA in 3-oz serving of steak fillet and 0.06 g CLA in 8-oz serving of whole milk. The peroxide value of the oil extracted from potato chips was found to be 1 meq/1000 g sample, which was within the acceptable commercial standards. This study may lead to the commercialization of CLA-rich food products.

  20. Hamman-Rich syndrome in a goldsmith

    International Nuclear Information System (INIS)

    Kirchner, J.; Stein, A.; Jacobi, V.; Viel, K.

    1997-01-01

    We report the case of a 54-year-old goldsmith admitted because of dyspnea on exertion, persistent cough, and weakness under the suspicion of exogenous allergic alveolitis. He rapidly developed progressive lung fibrosis with exitus letalis 7 weeks after admission. Radiological examination (chest X-ray and HRCT) first showed ground glass opacities, and later rapid development of severe interstitial pattern with architectural distraction. The findings were similar to idiopathic lung fibrosis; however, the rare Hamman-Rich syndrome was confirmed by progressive course of the disease. Correlations between Hamann-Rich syndrome and idiopathic lung fibrosis are discussed. (orig.) [de

  1. Cross Cultural Images: The ETSU/NAU Special Photography Project.

    Science.gov (United States)

    Montgomery, Donna; Sluss, Dorothy; Lewis, Jamie; Vervelde, Peggy; Prater, Greg; Minner, Sam

    Recreation is a significant part of a full and rich life but is frequently overlooked in relation to handicapped children. A project called Cross-Cultural Images aimed to improve the quality of life for handicapped children by teaching them avocational photography skills. The project involved mildly handicapped children aged 7-11 in Appalachia, on…

  2. Diversification rates and species richness across the Tree of Life.

    Science.gov (United States)

    Scholl, Joshua P; Wiens, John J

    2016-09-14

    Species richness varies dramatically among clades across the Tree of Life, by over a million-fold in some cases (e.g. placozoans versus arthropods). Two major explanations for differences in richness among clades are the clade-age hypothesis (i.e. species-rich clades are older) and the diversification-rate hypothesis (i.e. species-rich clades diversify more rapidly, where diversification rate is the net balance of speciation and extinction over time). Here, we examine patterns of variation in diversification rates across the Tree of Life. We address how rates vary across higher taxa, whether rates within higher taxa are related to the subclades within them, and how diversification rates of clades are related to their species richness. We find substantial variation in diversification rates, with rates in plants nearly twice as high as in animals, and rates in some eukaryotes approximately 10-fold faster than prokaryotes. Rates for each kingdom-level clade are then significantly related to the subclades within them. Although caution is needed when interpreting relationships between diversification rates and richness, a positive relationship between the two is not inevitable. We find that variation in diversification rates seems to explain most variation in richness among clades across the Tree of Life, in contrast to the conclusions of previous studies. © 2016 The Author(s).

  3. Functional richness: Overview of indices and underlying concepts

    Science.gov (United States)

    Legras, G.; Loiseau, N.; Gaertner, J.-C.

    2018-02-01

    Functional richness, currently defined as the amount of niche space occupied by the species within a community, is one of the three major components of functional diversity. Different indices have been developed in order to quantify this component. However, the range of indices available for assessing functional richness, often mathematically complex and based on different rationales, can cause confusion for field ecologists and lead to misinterpretation of the results obtained. In this context, we have provided the first study exclusively focused on the comparison of the definitions, advantages and drawbacks of a large set of functional richness indices. The first part of this work is focused on four indices (FDP&G, FRic, TOP and N-hypervolumes indices) that are currently the most commonly used for assessing functional richness. We have completed our study by including recently developed indices that enable us to take into account the intraspecific trait variability (i.e. FRim index and TDP framework), because there is currently a growing scientific consensus regarding the necessity of including this aspect in the assessment of the functional diversity of communities. We demonstrate that although authors have argued that their index describes the functional richness, each of them describes only part of it, and this part may strongly differ from one index to another. Rather than advocating the general use of a single index and/or systematically avoiding others, our study highlights the need for selecting indices in close relation with the context, the available data and the aims of each study. Such a strategy is an essential preliminary step for preventing misunderstanding and artefactual controversies. Along these lines, we propose some guidelines to help users in selecting the most appropriate indices according both to the facet of functional richness on which they wish to focus and to the characteristics of the available data.

  4. Platelet rich plasma in dermatology and aesthetic medicine

    OpenAIRE

    Neerja Puri

    2015-01-01

    Platelet rich plasma is a promising therapy in dermatology and aesthetic medicine. In this article we will discuss the pros and cons of platelet rich plasma (PRP) and the usage of PRP in aesthetics. PRP is especially used for conditions like facial and neck rejuvenation, fine lines and wrinkles, abdominal striae and facial scarring.

  5. Species richness inside and outside long-term exclosures

    Science.gov (United States)

    W. A. Laycock; D. L. Bartos; K. D. Klement

    2004-01-01

    Recent environmental literature contains claims that livestock grazing has caused reduction in species diversity on Western rangelands. Data of species richness (number of species) is presented from inside and outside 24 long-term exclosures in Montana, Utah, and Wyoming. For the average of all exclosures there was no difference between species richness inside and...

  6. Cutting-edge analysis of extracellular microparticles using ImageStream(X) imaging flow cytometry.

    Science.gov (United States)

    Headland, Sarah E; Jones, Hefin R; D'Sa, Adelina S V; Perretti, Mauro; Norling, Lucy V

    2014-06-10

    Interest in extracellular vesicle biology has exploded in the past decade, since these microstructures seem endowed with multiple roles, from blood coagulation to inter-cellular communication in pathophysiology. In order for microparticle research to evolve as a preclinical and clinical tool, accurate quantification of microparticle levels is a fundamental requirement, but their size and the complexity of sample fluids present major technical challenges. Flow cytometry is commonly used, but suffers from low sensitivity and accuracy. Use of Amnis ImageStream(X) Mk II imaging flow cytometer afforded accurate analysis of calibration beads ranging from 1 μm to 20 nm; and microparticles, which could be observed and quantified in whole blood, platelet-rich and platelet-free plasma and in leukocyte supernatants. Another advantage was the minimal sample preparation and volume required. Use of this high throughput analyzer allowed simultaneous phenotypic definition of the parent cells and offspring microparticles along with real time microparticle generation kinetics. With the current paucity of reliable techniques for the analysis of microparticles, we propose that the ImageStream(X) could be used effectively to advance this scientific field.

  7. An Ecofeminist Approach to Adrienne Rich's Poem "Diving into the Wreck" Adrienne

    OpenAIRE

    ERKAN, Ayça Ülker

    2012-01-01

    This study examines Adrienne Rich\\'s poem “Diving into the Wreck” (1973) through ecofeminist criticism. Rich\\'s ecopoetry questions assumptions about feminine subjectivity and female consciousness, patriarchal abuse, and indifference regarding women. With the androgynous persona in the poem “I”, Rich moves beyond the limits of gender and sexes to give room to form female subjectivity. Persona in the poem starts to explore and express her feminine identity and sexuality by figuratively “diving...

  8. Multiscale assessment of patterns of avian species richness

    DEFF Research Database (Denmark)

    Rahbek, C; Graves, G R

    2001-01-01

    at continental scales. We used a database of the geographic ranges of 2,869 species of birds breeding in South America (nearly a third of the world's living avian species) to explore the influence of climate, quadrat area, ecosystem diversity, and topography on species richness gradients at 10 spatial scales...... (quadrat area, approximately 12,300 to approximately 1,225,000 km(2)). Topography, precipitation, topography x latitude, ecosystem diversity, and cloud cover emerged as the most important predictors of regional variability of species richness in regression models incorporating 16 independent variables...... the hypothesis that terrestrial species richness from the equator to the poles is ultimately governed by a synergism between climate and coarse-scale topographic heterogeneity....

  9. Recent operational performance of the CERN Omega Ring Imaging Cerenkov Detector

    International Nuclear Information System (INIS)

    Apsimon, R.J.; Flower, P.S.; Freeston, K.A.

    1985-10-01

    We discuss the design and construction of the Time Projection chambers (TPCs) of the Omega Ring Imaging Cerenkov Detector (RICH). Details are given of the TPC high voltage system and its monitoring and control. In addition, the operation and monitoring of the readout is described together with results of tests on the performance of the front end amplifiers. The operation of the RICH TPCs and electronics during the first data run of WA69, in 1984, is discussed together with relevant results from laboratory tests. Results from the preliminary analysis of a sample of data from the 1984 run are also presented

  10. Platelet rich plasma in dermatology and aesthetic medicine

    Directory of Open Access Journals (Sweden)

    Neerja Puri

    2015-04-01

    Full Text Available Platelet rich plasma is a promising therapy in dermatology and aesthetic medicine. In this article we will discuss the pros and cons of platelet rich plasma (PRP and the usage of PRP in aesthetics. PRP is especially used for conditions like facial and neck rejuvenation, fine lines and wrinkles, abdominal striae and facial scarring.

  11. Value-Added Products from FGD Sulfite-Rich Scrubber Materials

    Energy Technology Data Exchange (ETDEWEB)

    Vivak Malhotra

    2010-01-31

    According to the American Coal Ash Association, about 29.25 million tons of flue gas desulfurization (FGD) byproducts were produced in the USA in 2003. Out of 29.25 million tons, 17.35 million tons were sulfite-rich scrubber materials. At present, unlike its cousin FGD gypsum, the prospect for effective utilization of sulfite-rich scrubber materials is not bright. In fact, almost 16.9 million tons are leftover every year. In our pursuit to mitigate the liability of sulfite-rich FGD scrubber materials' disposal, we are attempting to develop value-added products that can commercially compete. More specifically, for this Innovative Concept Phase I project, we have the following objectives: to characterize the sulfite-rich scrubber material for toxic metals; to optimize the co-blending and processing of scrubber material and natural byproducts; to formulate and develop structural composites from sulfite-rich scrubber material; and to evaluate the composites' mechanical properties and compare them with current products on the market. After successfully demonstrating the viability of our research, a more comprehensive approach will be proposed to take these value-added materials to fruition.

  12. Treatment of Knee Osteochondral Lesions Using a Novel Clot of Autologous Plasma Rich in Growth Factors Mixed with Healthy Hyaline Cartilage Chips and Intra-Articular Injection of PRGF.

    Science.gov (United States)

    Cugat, Ramón; Alentorn-Geli, Eduard; Steinbacher, Gilbert; Álvarez-Díaz, Pedro; Cuscó, Xavier; Seijas, Roberto; Barastegui, David; Navarro, Jordi; Laiz, Patricia; García-Balletbó, Montserrat

    2017-01-01

    Knee cartilage or osteochondral lesions are common and challenging injuries. To date, most symptomatic lesions warrant surgical treatment. We present two cases of patients with knee osteochondral defects treated with a one-step surgical procedure consisting of an autologous-based matrix composed of healthy hyaline cartilage chips, mixed plasma poor-rich in platelets clot, and plasma rich in growth factors (PRGF). Both patients returned to playing soccer at the preinjury activity level and demonstrated excellent defect filling in both magnetic resonance imaging and second-look arthroscopy (in one of them). The use of a clot of autologous plasma poor in platelets with healthy hyaline cartilage chips and intra-articular injection of plasma rich in platelets is an effective, easy, and cheap option to treat knee cartilage injuries in young and athletic patients.

  13. Treatment of Knee Osteochondral Lesions Using a Novel Clot of Autologous Plasma Rich in Growth Factors Mixed with Healthy Hyaline Cartilage Chips and Intra-Articular Injection of PRGF

    Directory of Open Access Journals (Sweden)

    Ramón Cugat

    2017-01-01

    Full Text Available Knee cartilage or osteochondral lesions are common and challenging injuries. To date, most symptomatic lesions warrant surgical treatment. We present two cases of patients with knee osteochondral defects treated with a one-step surgical procedure consisting of an autologous-based matrix composed of healthy hyaline cartilage chips, mixed plasma poor-rich in platelets clot, and plasma rich in growth factors (PRGF. Both patients returned to playing soccer at the preinjury activity level and demonstrated excellent defect filling in both magnetic resonance imaging and second-look arthroscopy (in one of them. The use of a clot of autologous plasma poor in platelets with healthy hyaline cartilage chips and intra-articular injection of plasma rich in platelets is an effective, easy, and cheap option to treat knee cartilage injuries in young and athletic patients.

  14. Vertebrate richness and biogeography in the Big Thicket of Texas

    Science.gov (United States)

    Michael H MacRoberts; Barbara R. MacRoberts; D. Craig Rudolph

    2010-01-01

    The Big Thicket of Texas has been described as rich in species and a “crossroads:” a place where organisms from many different regions meet. We examine the species richness and regional affiliations of Big Thicket vertebrates. We found that the Big Thicket is neither exceptionally rich in vertebrates nor is it a crossroads for vertebrates. Its vertebrate fauna is...

  15. Platelet-rich plasma, plasma rich in growth factors and simvastatin in the regeneration and repair of alveolar bone.

    Science.gov (United States)

    Rivera, César; Monsalve, Francisco; Salas, Juan; Morán, Andrea; Suazo, Iván

    2013-12-01

    Platelet preparations promote bone regeneration by inducing cell migration, proliferation and differentiation in the area of the injury, which are essential processes for regeneration. In addition, several studies have indicated that simvastatin (SIMV), widely used for the treatment of hypercholesterolemia, stimulates osteogenesis. The objective of this study was to evaluate the effects of treatment with either platelet-rich plasma (PRP) or plasma rich in growth factors (PRGF) in combination with SIMV in the regeneration and repair of alveolar bone. The jaws of Sprague Dawley rats (n=18) were subjected to rotary instrument-induced bone damage (BD). Animals were divided into six groups: BD/H 2 O (n=3), distilled water without the drug and alveolar bone damage; BD/H 2 O/PRP (n=3), BD and PRP; BD/H 2 O/PRGF (n=3), BD and PRGF; BD/SIMV (n=3), BD and water with SIMV; BD/SIMV/PRP (n=3), BD, PRP and SIMV; and BD/SIMV/PRGF (n=3), BD, PRGF and SIMV. Conventional histological analysis (hematoxylin and eosin staining) revealed that the BD/SIMV group showed indicators for mature bone tissue, while the BD/SIMV/PRP and BD/SIMV/PRGF groups showed the coexistence of indicators for mature and immature bone tissue, with no statistical differences between the platelet preparations. Simvastatin did not improve the effect of platelet-rich plasma and plasma rich in growth factors. It was not possible to determine which platelet preparation produced superior effects.

  16. Platelet-rich fibrin or platelet-rich plasma – which one is better? an opinion

    Directory of Open Access Journals (Sweden)

    Shweta Bansal

    2017-01-01

    Full Text Available The healing of hard and soft tissue in mediated by a wide range of intracellular and extracellular events that are regulated by signaling proteins. Platelets can play a crucial role in periodontal regeneration as they are the reservoirs of growth factors and cytokines which are the key factors for regeneration of bone and maturation of soft tissue. Platelet-rich plasma (PRP is first generation platelet concentrate. However, the short duration of cytokine release and its poor mechanical properties have resulted in search of new material. Platelet-rich fibrin (PRF is a natural fibrin-based biomaterial prepared from an anticoagulant-free blood harvest without any artificial biochemical modification (no bovine thrombin is required that allows obtaining fibrin membranes enriched with platelets and growth factors. The slow polymerization during centrifugation, fibrin-based structure, ease of preparation, minimal expense makes PRF somewhat superior in some aspect to PRP.

  17. Topology of digital images visual pattern discovery in proximity spaces

    CERN Document Server

    Peters, James F

    2014-01-01

    This book carries forward recent work on visual patterns and structures in digital images and introduces a near set-based a topology of digital images. Visual patterns arise naturally in digital images viewed as sets of non-abstract points endowed with some form of proximity (nearness) relation. Proximity relations make it possible to construct uniform topolo- gies on the sets of points that constitute a digital image. In keeping with an interest in gaining an understanding of digital images themselves as a rich source of patterns, this book introduces the basics of digital images from a computer vision perspective. In parallel with a computer vision perspective on digital images, this book also introduces the basics of prox- imity spaces. Not only the traditional view of spatial proximity relations but also the more recent descriptive proximity relations are considered. The beauty of the descriptive proximity approach is that it is possible to discover visual set patterns among sets that are non-overlapping ...

  18. The STAR-RICH Detector

    CERN Document Server

    Lasiuk, B; Braem, André; Cozza, D; Davenport, M; De Cataldo, G; Dell'Olio, L; Di Bari, D; Di Mauro, A; Dunlop, J C; Finch, E; Fraissard, Daniel; Franco, A; Gans, J; Ghidini, B; Harris, J W; Horsley, M; Kunde, G J; Lasiuk, B; Lesenechal, Y; Majka, R D; Martinengo, P; Morsch, Andreas; Nappi, E; Paic, G; Piuz, François; Posa, F; Raynaud, J; Salur, S; Sandweiss, J; Santiard, Jean-Claude; Satinover, J; Schyns, E M; Smirnov, N; Van Beelen, J; Williams, T D; Xu, Z

    2002-01-01

    The STAR-RICH detector extends the particle idenfication capabilities of the STAR spectrometer for charged hadrons at mid-rapidity. It allows identification of pions and kaons up to ~3 GeV/c and protons up to ~5 GeV/c. The characteristics and performance of the device in the inaugural RHIC run are described.

  19. The LHCb RICH system; detector description and operation

    Energy Technology Data Exchange (ETDEWEB)

    Papanestis, A., E-mail: antonis.papanestis@stfc.ac.uk

    2014-12-01

    Two RICH detectors provide positive charged hadron identification in the LHCb experiment at the Large Hadron Collider at CERN. RICH 1 covers the full acceptance of the spectrometer and contains two radiators: aerogel and C{sub 4}F{sub 10}. RICH 2 covers half the acceptance and uses CF{sub 4} as a Cherenkov radiator. Photon detection is performed by the Hybrid Photon Detectors (HPDs), with silicon pixel sensors and bump-bonded readout encapsulated in a vacuum tube for efficient, low-noise single photon detection. The LHCb RICH detectors form a complex system of three radiators, 120 mirrors and 484 photon detectors operating in the very challenging environment of the LHC. The high performance of the system in pion and kaon identification in the momentum range of 2–100 GeV/c is reached only after careful calibration of many parameters. Operational efficiency above 99% was achieved by a high level of automatization in the operation of the detectors, from switching-on to error recovery. The challenges of calibrating and operating such a system will be presented. - Highlights: • This paper describes the operation and calibration of the LHCb RICH detectors. • The scintillation of CF{sub 4} was successfully suppressed with CO{sub 2}. • The refractive index of the gas radiators was calibrated with data to an accuracy better than 0.1%. • The Hybrid Photons Detectors were calibrated for operation in a magnetic field without loss of resolution.

  20. G-rich, a Drosophila selenoprotein, is a Golgi-resident type III membrane protein

    International Nuclear Information System (INIS)

    Chen, Chang Lan; Shim, Myoung Sup; Chung, Jiyeol; Yoo, Hyun-Seung; Ha, Ji Min; Kim, Jin Young; Choi, Jinmi; Zang, Shu Liang; Hou, Xiao; Carlson, Bradley A.; Hatfield, Dolph L.; Lee, Byeong Jae

    2006-01-01

    G-rich is a Drosophila melanogaster selenoprotein, which is a homologue of human and mouse SelK. Subcellular localization analysis using GFP-tagged G-rich showed that G-rich was localized in the Golgi apparatus. The fusion protein was co-localized with the Golgi marker proteins but not with an endoplasmic reticulum (ER) marker protein in Drosophila SL2 cells. Bioinformatic analysis of G-rich suggests that this protein is either type II or type III transmembrane protein. To determine the type of transmembrane protein experimentally, GFP-G-rich in which GFP was tagged at the N-terminus of G-rich, or G-rich-GFP in which GFP was tagged at the C-terminus of G-rich, were expressed in SL2 cells. The tagged proteins were then digested with trypsin, and analyzed by Western blot analysis. The results showed that the C-terminus of the G-rich protein was exposed to the cytoplasm indicating it is a type III microsomal membrane protein. G-rich is First selenoprotein identified in the Golgi apparatus

  1. Development of opto-mechanical tools and procedures for the new generation of RICH-detectors at CERN

    CERN Document Server

    Laub, M; Ullaland, O

    2001-01-01

    This thesis is focused on development of opto-mechanical tools and procedures, which would contribute to the achievement of the best possible performance of new Ring Imaging Cherenkov (RICH) detectors. On the base of requirements, given by the physics objective of the LHCb detector, and an analysis of the detector opto-mechanical system, specifications of individual opto-mechanical components were determined. Spherical mirrors, planar mirrors and mirror adjustable mounts were the components of interest. Next, their parameters to be characterised were defined. Possible measurement methods were studied and relevant set ups based on suitable methods were developed. Meanwhile, available modern metrology technologies, like laser operated instruments or digital image processing, were applied with an attempt to innovate them and to increase their achievable performance limits. When applicable, the set ups were automated in order to make the measurements fast and reliable. An optical laboratory, devoted to the charac...

  2. Species richness of arbuscular mycorrhizal fungi: associations with grassland plant richness and biomass

    Czech Academy of Sciences Publication Activity Database

    Hiiesalu, Inga; Pärtel, M.; Davison, J.; Gerhold, P.; Metsis, M.; Moora, M.; Öpik, M.; Vasar, M.; Zobel, M.; Wilson, S. D.

    2014-01-01

    Roč. 203, č. 1 (2014), s. 233-244 ISSN 1469-8137 R&D Projects: GA MŠk EE2.3.30.0048 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : belowground plant richness * diversity * productivity Subject RIV: EH - Ecology, Behaviour Impact factor: 6.545, year: 2013

  3. Planetary optical and infrared imaging

    International Nuclear Information System (INIS)

    Terrile, R.J.

    1988-01-01

    The purpose of this investigation is to obtain and analyze high spatial resolution charge coupled device (CCD) coronagraphic images of extra-solar planetary material and solar system objects. These data will provide information on the distribution of planetary and proto-planetary material around nearby stars leading to a better understanding of the origin and evolution of the solar system. Imaging within our solar system will provide information on the current cloud configurations on the outer planets, search for new objects around the outer planets, and provide direct support for Voyager, Galileo, and CRAF by imaging material around asteroids and clouds on Neptune. Over the last year this program acquired multispectral and polarization images of the disk of material around the nearby star Beta Pictoris. This material is believed to be associated with the formation of planets and provides a first look at a planetary system much younger than our own. Preliminary color and polarization data suggest that the material is very low albedo and similar to dark outer solar system carbon rich material. A coronagraphic search for other systems is underway and has already examined over 100 nearby stars. Coronagraphic imaging provided the first clear look at the rings of Uranus and albedo limits for the ring arcs around Neptune

  4. Evaluation of osteoblastic activity in extraction sockets treated with platelet-rich fibrin.

    Science.gov (United States)

    Baslarli, Ozgur; Tumer, Celal; Ugur, Omer; Vatankulu, Betul

    2015-01-01

    The aim of this study was to determine whether the use of platelet rich fibrin (PRF) improved the healing of extraction sockets. A total of 20 patients with bilateral soft tissue impacted mandibular third molars were included in this study. The left and right third molars were extracted during the same session. Subsequently, the PRF membrane was randomly administered to one of the extraction sockets, whereas the contralateral sockets were left without treatment. On postoperative 30. and 90. days, panoramic images and bone scintigrams were taken to evaluate the bone healing between PRF-treated and non-PRF-treated sockets. Also, periodontal evaluation was performed in the same control sessions. Dependent group t test for paired samples was used for statistical analysis. The average increase in technetium-99m methylene diphosphonate uptake as an indication of enhanced bone healing did not differ significantly between PRF-treated and non-PRF-treated sockets 30 and 90 days postoperatively. Radio-opacity that can show the bone healing on panoramic images were measured by Image J programme and they did not differ significantly. Also periodontal values did not differ significantly. PRF might not lead to enhanced bone healing in impacted mandibular third molar extraction sockets 30 and 90 days after surgery. It is thought that PRF has the potential characteristics of an autologous fibrin matrix and can accelerate the healing. To better understand the effects of PRF on healing, further research is warranted with larger sample sizes.

  5. Voxel-based plaque classification in coronary intravascular optical coherence tomography images using decision trees

    Science.gov (United States)

    Kolluru, Chaitanya; Prabhu, David; Gharaibeh, Yazan; Wu, Hao; Wilson, David L.

    2018-02-01

    Intravascular Optical Coherence Tomography (IVOCT) is a high contrast, 3D microscopic imaging technique that can be used to assess atherosclerosis and guide stent interventions. Despite its advantages, IVOCT image interpretation is challenging and time consuming with over 500 image frames generated in a single pullback volume. We have developed a method to classify voxel plaque types in IVOCT images using machine learning. To train and test the classifier, we have used our unique database of labeled cadaver vessel IVOCT images accurately registered to gold standard cryoimages. This database currently contains 300 images and is growing. Each voxel is labeled as fibrotic, lipid-rich, calcified or other. Optical attenuation, intensity and texture features were extracted for each voxel and were used to build a decision tree classifier for multi-class classification. Five-fold cross-validation across images gave accuracies of 96 % +/- 0.01 %, 90 +/- 0.02% and 90 % +/- 0.01 % for fibrotic, lipid-rich and calcified classes respectively. To rectify performance degradation seen in left out vessel specimens as opposed to left out images, we are adding data and reducing features to limit overfitting. Following spatial noise cleaning, important vascular regions were unambiguous in display. We developed displays that enable physicians to make rapid determination of calcified and lipid regions. This will inform treatment decisions such as the need for devices (e.g., atherectomy or scoring balloon in the case of calcifications) or extended stent lengths to ensure coverage of lipid regions prone to injury at the edge of a stent.

  6. Leveraging data rich environments using marketing analytics

    OpenAIRE

    Holtrop, Niels

    2017-01-01

    With the onset of what is popularly known as “big data”, increased attention is being paid to creating value from these data rich environments. Within the field of marketing, the analysis of customer and market data supported by models is known as marketing analytics. The goal of these analyses is to enhance managerial decision making regarding marketing problems. However, before these data rich environments can be used to guide managerial decision making, firms need to grasp the process of d...

  7. Quantifying Porosity through Automated Image Collection and Batch Image Processing: Case Study of Three Carbonates and an Aragonite Cemented Sandstone

    Directory of Open Access Journals (Sweden)

    Jim Buckman

    2017-08-01

    Full Text Available Modern scanning electron microscopes often include software that allows for the possibility of obtaining large format high-resolution image montages over areas of several square centimeters. Such montages are typically automatically acquired and stitched, comprising many thousand individual tiled images. Images, collected over a regular grid pattern, are a rich source of information on factors such as variability in porosity and distribution of mineral phases, but can be hard to visually interpret. Additional quantitative data can be accessed through the application of image analysis. We use backscattered electron (BSE images, collected from polished thin sections of two limestone samples from the Cretaceous of Brazil, a Carboniferous limestone from Scotland, and a carbonate cemented sandstone from Northern Ireland, with up to 25,000 tiles per image, collecting numerical quantitative data on the distribution of porosity. Images were automatically collected using the FEI software Maps, batch processed by image analysis (through ImageJ, with results plotted on 2D contour plots with MATLAB. These plots numerically and visually clearly express the collected porosity data in an easily accessible form, and have application for the display of other data such as pore size, shape, grain size/shape, orientation and mineral distribution, as well as being of relevance to sandstone, mudrock and other porous media.

  8. Global hotspots and correlates of alien species richness across taxonomic groups

    Science.gov (United States)

    Dawson, Wayne; Moser, Dietmar; van Kleunen, Mark; Kreft, Holger; Pergl, Jan; Pysek, Petr; Weigelt, Patrick; Winter, Marten; Lenzner, Bernd; Blackburn, Tim M.; Dyer, Ellie; Cassey, Phillip; Scrivens, Sally-Louise; Economo, Evan P.; Guenard, Benoit; Capinha, Cesar; Seebens, Hanno; Garcia-Diaz, Pablo; Nentwig, Wolfgang; Garcia-Berthou, Emili; Casal, Christine; Mandrak, Nicholas E.; Fuller, Pam; Meyer, Carsten; Essl, Franz

    2017-01-01

    Human-mediated transport beyond biogeographic barriers has led to the introduction and establishment of alien species in new regions worldwide. However, we lack a global picture of established alien species richness for multiple taxonomic groups. Here, we assess global patterns and potential drivers of established alien species richness across eight taxonomic groups (amphibians, ants, birds, freshwater fishes, mammals, vascular plants, reptiles and spiders) for 186 islands and 423 mainland regions. Hotspots of established alien species richness are predominantly island and coastal mainland regions. Regions with greater gross domestic product per capita, human population density, and area have higher established alien richness, with strongest effects emerging for islands. Ants and reptiles, birds and mammals, and vascular plants and spiders form pairs of taxonomic groups with the highest spatial congruence in established alien richness, but drivers explaining richness differ between the taxa in each pair. Across all taxonomic groups, our results highlight the need to prioritize prevention of further alien species introductions to island and coastal mainland regions globally.

  9. Platelet-rich fibrin in the treatment of periodontal bone defects.

    Science.gov (United States)

    Ranganathan, Aravindhan T; Chandran, Chitraa R

    2014-05-01

    Periodontitis is characterized by the formation of true pockets, bone loss and attachment loss. Various techniques have been attempted in the past to truly regenerate the lost periodontal structures, albeit with variable outcome. In this evolution, the technique being tried out widely is the use of platelet rich concentrates, namely platelet-rich fibrin (PRF). In this report, we present a case of surgical treatment of osseous bone defects namely two walled crater and dehiscence treated in posterior teeth with autologously prepared platelet rich fibrin mixed with hydroxy apatite bone graft and PRF in the form of a membrane. Our results showed clinical improvements in all the clinical parameters postoperatively namely the pocket depth reduction and gain in attachment level and hence, PRF can be used alone or in combination with the bone graft to yield successful clinical results in treating periodontal osseous defects. Platelet-rich fibrin is an effective alternative to platelet-rich plasma (PRP) in reconstructing bone defects.

  10. Diffusion mediated coagulation and fragmentation based study of domain formation in lipid bilayer membrane

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Laxminarsimha V., E-mail: laxman@iitk.ac.in [Mechanics and Applied Mathematics Group, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Roy, Subhradeep [Department of Biomedical Engineering and Mechanics (MC 0219), Virginia Tech, 495 Old Turner Street, Blacksburg, VA 24061 (United States); Das, Sovan Lal [Mechanics and Applied Mathematics Group, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

    2017-01-15

    We estimate the equilibrium size distribution of cholesterol rich micro-domains on a lipid bilayer by solving Smoluchowski equation for coagulation and fragmentation. Towards this aim, we first derive the coagulation kernels based on the diffusion behaviour of domains moving in a two dimensional membrane sheet, as this represents the reality better. We incorporate three different diffusion scenarios of domain diffusion into our coagulation kernel. Subsequently, we investigate the influence of the parameters in our model on the coagulation and fragmentation behaviour. The observed behaviours of the coagulation and fragmentation kernels are also manifested in the equilibrium domain size distribution and its first moment. Finally, considering the liquid domains diffusing in a supported lipid bilayer, we fit the equilibrium domain size distribution to a benchmark solution.

  11. ACTH radioimmunocytochemistry (RICH) on rat anterior pituitary cells

    International Nuclear Information System (INIS)

    Rappay, G.; Karteszi, M.; Makara, G.B.

    1979-01-01

    Radioimmunocytochemistry (RICH) was applied to detect corticotrophs in adult rat pituitaries and 8-day-old anterior pituitary monolayers by incubating sections and cultures with 125 I-ACTH-anti ACTH immune complexes. After incubations autoradiography was made. In comparison, 'conventional' immunostaining was carried out on adjacent sections and parallel cultures. It has been established that RICH is suitable for detection of corticotrophs. (orig.) [de

  12. Antiproliferative effects of γ-tocotrienol are associated with lipid raft disruption in HER2-positive human breast cancer cells.

    Science.gov (United States)

    Alawin, Osama A; Ahmed, Rayan A; Ibrahim, Baher A; Briski, Karen P; Sylvester, Paul W

    2016-01-01

    A large percentage of human breast cancers are characterized by excessive or aberrant HER2 activity. Lipid rafts are specialized microdomains within the plasma membrane that are required for HER2 activation and signal transduction. Since the anticancer activity of γ-tocotrienol is associated with suppression in HER2 signaling, studies were conducted to examine the effects of γ-tocotrienol on HER2 activation within the lipid raft microdomain in HER2-positive SKBR3 and BT474 human breast cancer cells. Treatment with 0-5μM γ-tocotrienol induced a significant dose-dependent inhibition in cancer cell growth after a 5-day culture period, and these growth inhibitory effects were associated with a reduction in HER2 dimerization and phosphorylation (activation). Phosphorylated HER2 was found to be primarily located in the lipid raft microdomain of the plasma membrane in vehicle-treated control groups, whereas γ-tocotrienol treatment significantly inhibited this effect. Assay of plasma membrane subcellular fractions showed that γ-tocotrienol also accumulates exclusively within the lipid raft microdomain. Hydroxypropyl-β-cyclodextrin (HPβCD) is an agent that disrupts lipid raft integrity. Acute exposure to 3mM HPβCD alone had no effect, whereas an acute 24-h exposure to 20μM γ-tocotrienol alone significantly decreased SKBR3 and BT474 cell viability. However, combined treatment with these agents greatly reduced γ-tocotrienol accumulation in the lipid raft microdomain and cytotoxicity. In summary, these findings demonstrate that the anticancer effects of γ-tocotrienol are associated with its accumulation in the lipid raft microdomain and subsequent interference with HER2 dimerization and activation in SKBR3 and BT474 human breast cancer cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Structural diversity and evolution of the N-terminal isoform-specific region of ecdysone receptor-A and -B1 isoforms in insects

    Directory of Open Access Journals (Sweden)

    Kubo Takeo

    2010-02-01

    Full Text Available Abstract Background The ecdysone receptor (EcR regulates various cellular responses to ecdysteroids during insect development. Insects have multiple EcR isoforms with different N-terminal A/B domains that contain the isoform-specific activation function (AF-1 region. Although distinct physiologic functions of the EcR isoforms have been characterized in higher holometabolous insects, they remain unclear in basal direct-developing insects, in which only A isoform has been identified. To examine the structural basis of the EcR isoform-specific AF-1 regions, we performed a comprehensive structural comparison of the isoform-specific region of the EcR-A and -B1 isoforms in insects. Results The EcR isoforms were newly identified in 51 species of insects and non-insect arthropods, including direct-developing ametabolous and hemimetabolous insects. The comprehensive structural comparison revealed that the isoform-specific region of each EcR isoform contained evolutionally conserved microdomain structures and insect subgroup-specific structural modifications. The A isoform-specific region generally contained four conserved microdomains, including the SUMOylation motif and the nuclear localization signal, whereas the B1 isoform-specific region contained three conserved microdomains, including an acidic activator domain-like motif. In addition, the EcR-B1 isoform of holometabolous insects had a novel microdomain at the N-terminal end. Conclusions Given that the nuclear receptor AF-1 is involved in cofactor recruitment and transcriptional regulation, the microdomain structures identified in the isoform-specific A/B domains might function as signature motifs and/or as targets for cofactor proteins that play essential roles in the EcR isoform-specific AF-1 regions. Moreover, the novel microdomain in the isoform-specific region of the holometabolous insect EcR-B1 isoform suggests that the holometabolous insect EcR-B1 acquired additional transcriptional

  14. Ilmenite-rich pyroclastic deposits - An ideal lunar resource

    Science.gov (United States)

    Hawke, B. R.; Clark, B.; Coombs, C. R.

    1990-01-01

    With a view of investigating possible economic benefits that a permanent lunar settlement might provide to the near-earth space infrastructures, consideration was given to the ilmenite-rich pyroclastic deposits as sources of oxygen (for use as a propellant) and He-3 (for nuclear fusion fuel). This paper demonstrates that ilmenite-rich pyroclastic deposits would be excellent sources of a wide variety of valuable elements besides O and He-3, including Fe, Ti, H2, N, C, S, Cu, Zn, Cd, Bi, and Pb. It is shown that several ilmenite-rich pyroclastic deposits of regional extent exist on the lunar surface. The suitability of regional pyroclastic deposits for lunar mining operations, construction activities, and the establishment of permanent lunar settlements is examined.

  15. Geographic range size and determinants of avian species richness

    DEFF Research Database (Denmark)

    Jetz, Walter; Rahbek, Carsten

    2002-01-01

    Geographic patterns in species richness are mainly based on wide-ranging species because their larger number of distribution records has a disproportionate contribution to the species richness counts. Here we demonstrate how this effect strongly influences our understanding of what determines spe...

  16. Measurement of aerogel performance for ring image Cherenkov detector of HERMES

    International Nuclear Information System (INIS)

    Kanesaka, Jiro; Zhang Linfeng; Sato, Fumiko; Suetsugu, Kentaro; Sakami, Yasuhiro; Shibata, Toshiaki

    1999-01-01

    The first experiment of ring image Cherenkov detector (RICH) used aerogel in the world was reported in this paper. We built RICH using aerogel as illuminant for HERMES. The refractive index and size of all aerogel tiles were measured in order to select them for construction of RICH. The select conditions of tile were 113.1 -4 , the dispersion of refractive index of aerogel tile, which condition was fitted to the accuracy of Cherenkov light emission angle of RICH. The mean thickness, transmission and reflection of tile, the thickness of corner of tile (thickness of surface), the refractive index dependence on position and temperature were measured. The effect of thickness of tile on the shift of Cherenkov emission angle was 6.1% the maximum value per one tile and 0.18% mean value of center. The effect of position dependence of refractive index on the Cherenkov light emission angle was agreed with the effect of dispersion of thickness of tile. The transmission and reflection of tile were almost same as the theoretical value. (S.Y.)

  17. Deriving the effective focal plane for the CBM-RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Kres, Ievgenii [Wuppertal University (Germany); Collaboration: CBM-Collaboration

    2016-07-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures in A+A collisions from 2-11 AGeV (SIS100). A central component of the proposed detector setup is a ring imaging Cherenkov detector (RICH) using CO2 as radiator gas, and a focussing optic with a large spherical mirror. In the present design, the optimal focal plane is approximated using four individual, flat detection surfaces. However, the exact shape and position of the ideal focal plane is subject to further optimization due to effects from tilting the focussing mirror and from momentum dependant deflection of the electron tracks in the magnetic stray field. In this talk, we present a new approach to derive the effective 3-dimensional shape of the focal plane based on a set of Monte Carlo simulations, comparing the ring sharpness at each point of a preliminary focal plane as function of z-position.

  18. Vesicle formation in the block copolymer/ homopolymer mixture studied by scattering methods

    International Nuclear Information System (INIS)

    Koizumi, Satoshi; Hasegawa, Hirokazu; Hashimoto, Takeji; Suzuki, Junnich.

    1993-01-01

    We studied morphology and spatial segmental distribution of particular binary mixtures of poly(styrene-block-isoprene)(SI) and homopolystyren, either protonated (HS) or deuterated (DS), with small angle-X-ray scattering (SAXS) and neutron scattering (SANS). The block copolymer SI used itself had a lamellar microdomain. Molecular weights of HS and DS were identical to each other and equal also to that of polystyrene block (PS) in SI. SAXS results obtained for SI and HS mixtures show that: (1) HS is solubilized in the PS microdomains; (2) the polyisoprene lamella has the thickness independent of w HS , weight fraction of HS, but its undulation depends on w HS . These two findings, in turn, imply that the HS added is localized in the middle of the PS microdomains, i.e., in between the PS brushes emanating from the interface of SI. We further confirmed this implication by SANS with a deuterium labeling technique; the DS segments studied for the SI/DS mixture is localized in the middle of PS microdomain with the penetration depth of 10 nm between DS and PS block chains. (author)

  19. Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness?

    Energy Technology Data Exchange (ETDEWEB)

    Seabloom, Eric W. [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Borer, Elizabeth T. [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Buckley, Yvonne [ARC Centre of Excellence for Environmental Decisions, School of Biological Sciences, The University of Queensland, Brisbane Queensland 4072 Australia; Cleland, Elsa E. [Ecology, Behavior & Evolution Section, University of California, San Diego La Jolla CA 92093 USA; Davies, Kendi [Department of Ecology and Evolutionary Biology, University of Colorado, Boulder CO 80309 USA; Firn, Jennifer [Queensland University of Technology, Biogeosciences, Brisbane Queensland 4000 Australia; Harpole, W. Stanley [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Hautier, Yann [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190 CH-8057 Zurich Switzerland; Lind, Eric [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; MacDougall, Andrew [Department of Integrative Biology, University of Guelph, Guelph Ontario N1G 2W1 Canada; Orrock, John L. [Department of Zoology, University of Wisconsin, Madison WI 53706 USA; Prober, Suzanne M. [CSIRO Ecosystem Sciences, Private Bag 5 Wembley WA 6913 Australia; Adler, Peter [Department of Wildland Resources and the Ecology Center, Utah State University, Logan UT 84322 USA; Alberti, Juan [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Michael Anderson, T. [Department of Biology, Wake Forest University, Winston-Salem NC 27109 USA; Bakker, Jonathan D. [School of Environmental and Forest Sciences, University of Washington, Seattle WA 98195-4115 USA; Biederman, Lori A. [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Blumenthal, Dana [Rangeland Resources Research Unit, USDA Agricultural Research Service, Fort Collins CO 80526 USA; Brown, Cynthia S. [Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins CO 80523 USA; Brudvig, Lars A. [Department of Plant Biology, Michigan State University, East Lansing MI 48824 USA; Caldeira, Maria [Centro de Estudos Florestais, Instituto Superior de Agronomia, Technical University of Lisbon, Lisbon Portugal; Chu, Chengjin [School of Life Sciences, Lanzhou University, Lanzhou 730000 China; Crawley, Michael J. [Department of Biology, Imperial College London, Silwood Park Ascot SL5 7PY UK; Daleo, Pedro [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Damschen, Ellen I. [Department of Zoology, University of Wisconsin, Madison WI 53706 USA; D' Antonio, Carla M. [Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara CA 93106 USA; DeCrappeo, Nicole M. [U.S. Geological Survey Forest and Rangeland Ecosystem Science Center, Corvallis OR 97331 USA; Dickman, Chris R. [Desert Ecology Research Group, School of Biological Sciences, University of Sydney, Sydney NSW 2006 Australia; Du, Guozhen [School of Life Sciences, Lanzhou University, Lanzhou 730000 China; Fay, Philip A. [USDA-ARS Grassland Soil and Water Research Lab, Temple TX 76502 USA; Frater, Paul [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Gruner, Daniel S. [Department of Entomology, University of Maryland, College Park MD 20742 USA; Hagenah, Nicole [School of Life Sciences, University of KwaZulu-Natal, Scottsville Pietermaritzburg 3209 South Africa; Department of Ecology, Evolutionary Biology, Yale University, New Haven CT 06520 USA; Hector, Andrew [Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190 CH-8057 Zurich Switzerland; Helm, Aveliina [Institute of Ecology and Earth Sciences, University of Tartu, Tartu Estonia; Hillebrand, Helmut [Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University, Wilhelmshaven Germany; Hofmockel, Kirsten S. [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Humphries, Hope C. [INSTAAR, University of Colorado, Boulder CO 80309-0450 USA; Iribarne, Oscar [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Jin, Virginia L. [USDA-ARS Agroecosystem Management Research Unit, Lincoln NE 68583 USA; Kay, Adam [Biology Department, University of St. Thomas, Saint Paul MN 55105 USA; Kirkman, Kevin P. [School of Life Sciences, University of KwaZulu-Natal, Scottsville Pietermaritzburg 3209 South Africa; Klein, Julia A. [Department Forest, Rangeland & Watershed Stewardship, Colorado State University, Fort Collins CO 80523-1472 USA; Knops, Johannes M. H. [School of Biological Sciences, University of Nebraska, Lincoln NE 68588 USA; La Pierre, Kimberly J. [Department of Ecology, Evolutionary Biology, Yale University, New Haven CT 06520 USA; Ladwig, Laura M. [Department of Biology, University of New Mexico, Albuquerque NM 87103 USA; Lambrinos, John G. [Department of Horticulture, Oregon State University, Corvallis OR 97331 USA; Leakey, Andrew D. B. [Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana IL 61801 USA; Li, Qi [Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008 Qinghai China; Li, Wei [Yunnan Academy of Biodiversity, Southwest Forestry University, Kunming 650224 China; McCulley, Rebecca [Department of Plant & Soil Sciences, University of Kentucky, Lexington KY 40546 USA; Melbourne, Brett [Department of Ecology and Evolutionary Biology, University of Colorado, Boulder CO 80309 USA; Mitchell, Charles E. [Department of Biology, University of North Carolina, Chapel Hill NC 27599 USA; Moore, Joslin L. [Australian Research Centre for Urban Ecology, Melbourne, c/o School of Botany, University of Melbourne, Melbourne Victoria 3010 Australia; Morgan, John [Department of Botany, La Trobe University, Bundoora 3086 Victoria Australia; Mortensen, Brent [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; O' Halloran, Lydia R. [Department of Zoology, Oregon State University, Corvallis OR 97331 USA; Pärtel, Meelis [Institute of Ecology and Earth Sciences, University of Tartu, Tartu Estonia; Pascual, Jesús [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Pyke, David A. [U.S. Geological Survey Forest and Rangeland Ecosystem Science Center, Corvallis OR 97331 USA; Risch, Anita C. [Swiss Federal Institute for Forest, Snow and Landscape Research, 8903 Birmensdorf Switzerland; Salguero-Gómez, Roberto [ARC Centre of Excellence for Environmental Decisions, School of Biological Sciences, The University of Queensland, Brisbane Queensland 4072 Australia; Sankaran, Mahesh [National Centre for Biological Sciences, GKVK Campus, Bellary Road Bangalore 560065 India; Schuetz, Martin [Swiss Federal Institute for Forest, Snow and Landscape Research, 8903 Birmensdorf Switzerland; Simonsen, Anna [Department of Ecology & Evolutionary Biology, University of Toronto, Toronto ON M5S 3B2 Canada; Smith, Melinda [Department of Biology, Colorado State University, Fort Collins CO 80523 USA; Stevens, Carly [Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ UK; Sullivan, Lauren [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Wardle, Glenda M. [Desert Ecology Research Group, School of Biological Sciences, University of Sydney, Sydney NSW 2006 Australia; Wolkovich, Elizabeth M. [Biodiversity Research Centre, University of British Columbia, Vancouver V6T 1Z4 Canada; Wragg, Peter D. [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Wright, Justin [Department of Biology, Duke University, Durham NC 27708 USA; Yang, Louie [Department of Entomology, University of California, Davis CA 95616 USA

    2013-10-16

    Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring

  20. Value-Added Products From FGD Sulfite-Rich Scrubber Materials

    Energy Technology Data Exchange (ETDEWEB)

    Vivak M. Malhotra

    2006-09-30

    Massive quantities of sulfite-rich flue gas desulfurization (FGD) scrubber materials are produced every year in the USA. In fact, at present, the production of wet sulfite-rich scrubber cake outstrips the production of wet sulfate-rich scrubber cake by about 6 million tons per year. However, most of the utilization focus has centered on FGD gypsum. Therefore, we have recently initiated research on developing new strategies for the economical, but environmentally-sound, utilization of sulfite-rich scrubber material. In this exploratory project (Phase I), we attempted to ascertain whether it is feasible to develop reconstituted wood replacement products from sulfite-rich scrubber material. In pursuit of this goal, we characterized two different wet sulfite-rich scrubber materials, obtained from two power plants burning Midwestern coal, for their suitability for the development of value-added products. The overall strategy adopted was to fabricate composites where the largest ingredient was scrubber material with additional crop materials as additives. Our results suggested that it may be feasible to develop composites with flexural strength as high as 40 MPa (5800 psi) without the addition of external polymers. We also attempted to develop load-bearing composites from scrubber material, natural fibers, and phenolic polymer. The polymer-to-solid ratio was limited to {le} 0.4. The formulated composites showed flexural strengths as high as 73 MPa (10,585 psi). We plan to harness the research outcomes from Phase I to develop parameters required to upscale our value-added products in Phase II.