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Sample records for phosphatidylinositol-4-phosphate 5-kinases mediate

  1. Phosphatidylinositol 4-phosphate 5-kinase α and Vav1 mutual cooperation in CD28-mediated actin remodeling and signaling functions.

    PubMed

    Muscolini, Michela; Camperio, Cristina; Porciello, Nicla; Caristi, Silvana; Capuano, Cristina; Viola, Antonella; Galandrini, Ricciarda; Tuosto, Loretta

    2015-02-01

    Phosphatidylinositol 4,5-biphosphate (PIP2) is a cell membrane phosphoinositide crucial for cell signaling and activation. Indeed, PIP2 is a pivotal source for second messenger generation and controlling the activity of several proteins regulating cytoskeleton reorganization. Despite its critical role in T cell activation, the molecular mechanisms regulating PIP2 turnover remain largely unknown. In human primary CD4(+) T lymphocytes, we have recently demonstrated that CD28 costimulatory receptor is crucial for regulating PIP2 turnover by allowing the recruitment and activation of the lipid kinase phosphatidylinositol 4-phosphate 5-kinase (PIP5Kα). We also identified PIP5Kα as a key modulator of CD28 costimulatory signals leading to the efficient T cell activation. In this study, we extend these data by demonstrating that PIP5Kα recruitment and activation is essential for CD28-mediated cytoskeleton rearrangement necessary for organizing a complete signaling compartment leading to downstream signaling functions. We also identified Vav1 as the linker molecule that couples the C-terminal proline-rich motif of CD28 to the recruitment and activation of PIP5Kα, which in turn cooperates with Vav1 in regulating actin polymerization and CD28 signaling functions.

  2. Type B Phosphatidylinositol-4-Phosphate 5-Kinases Mediate Arabidopsis and Nicotiana tabacum Pollen Tube Growth by Regulating Apical Pectin Secretion[W

    PubMed Central

    Ischebeck, Till; Stenzel, Irene; Heilmann, Ingo

    2008-01-01

    Phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2] occurs in the apical plasma membrane of growing pollen tubes. Because enzymes responsible for PtdIns(4,5)P2 production at that location are uncharacterized, functions of PtdIns(4,5)P2 in pollen tube tip growth are unresolved. Two candidate genes encoding pollen-expressed Arabidopsis thaliana phosphatidylinositol-4-phosphate 5-kinases (PI4P 5-kinases) of Arabidopsis subfamily B were identified (PIP5K4 and PIP5K5), and their recombinant proteins were characterized as being PI4P 5-kinases. Pollen of T-DNA insertion lines deficient in both PIP5K4 and PIP5K5 exhibited reduced pollen germination and defects in pollen tube elongation. Fluorescence-tagged PIP5K4 and PIP5K5 localized to an apical plasma membrane microdomain in Arabidopsis and tobacco (Nicotiana tabacum) pollen tubes, and overexpression of either PIP5K4 or PIP5K5 triggered multiple tip branching events. Further studies using the tobacco system revealed that overexpression caused massive apical pectin deposition accompanied by plasma membrane invaginations. By contrast, callose deposition and cytoskeletal structures were unaltered in the overexpressors. Morphological effects depended on PtdIns(4,5)P2 production, as an inactive enzyme variant did not produce any effects. The data indicate that excessive PtdIns(4,5)P2 production by type B PI4P 5-kinases disturbs the balance of membrane trafficking and apical pectin deposition. Polar tip growth of pollen tubes may thus be modulated by PtdIns(4,5)P2 via regulatory effects on membrane trafficking and/or apical pectin deposition. PMID:19060112

  3. Effects of polyamines and calcium and sodium ions on smooth muscle cytoskeleton-associated phosphatidylinositol (4)-phosphate 5-kinase.

    PubMed

    Chen, H; Baron, C B; Griffiths, T; Greeley, P; Coburn, R F

    1998-10-01

    In many different cell types, including smooth muscle cells (Baron et al., 1989, Am. J. Physiol., 256: C375-383; Baron et al., J. Pharmacol. Exp. Ther. 266: 8-15), phosphatidylinositol (4)-phosphate 5-kinase plays a critical role in the regulation of membrane concentrations of phosphatidylinositol (4,5)-bisphosphate and formation of inositol (1,4,5)-trisphosphate. In unstimulated porcine trachealis smooth muscle, 70% of total cellular phosphatidylinositol (4)-phosphate 5-kinase activity was associated with cytoskeletal proteins and only trace activity was detectable in isolated sarcolemma. Using two different preparations, we studied cytoskeleton-associated phosphatidyl inositol (4)-phosphate 5-kinase under conditions that attempted to mimic the ionic and thermal cytoplasmic environment of living cells. The cytoskeleton-associated enzyme, studied using phosphatidylinositol (4)-phosphate substrate concentrations that produced phosphatidylinositol 4,5-bisphosphate at about 10% of the maximal rate, was sensitive to free [Mg2+], had an absolute requirement for phosphatidylserine, phosphatidic acid, or phosphatidylinositol, and included type I isoforms. At 0.5 mM free [Mg2+], physiological spermine concentrations, 0.2-0.4 mM, increased phosphatidylinositol (4)-phosphate 5-kinase activity two to four times compared to controls run without spermine. The EC50 for spermine-evoked increases in activity was 0.17 +/- 0.02 mM. Spermine-evoked enzyme activity was a function of both free [Mg2+] and substrate concentration. Cytoskeleton-associated phosphatidylinositol (4)-phosphate 5-kinase was inhibited by free [Ca2+] over a physiological range for cytoplasm--10(-8) to 10(-5) M, an effect independent of the presence of calmodulin. Na+ over the range 20 to 50 mM also inhibited this enzyme activated by 5 mM Mg2+ but had no effect on spermine-activated enzyme. Na+, Ca2+, and spermine appear to be physiological modulators of smooth muscle cytoskeleton-bound phosphatidylinositol (4

  4. Phosphatidylinositol 4-Phosphate 5-Kinase β Controls Recruitment of Lipid Rafts into the Immunological Synapse.

    PubMed

    Kallikourdis, Marinos; Trovato, Anna Elisa; Roselli, Giuliana; Muscolini, Michela; Porciello, Nicla; Tuosto, Loretta; Viola, Antonella

    2016-02-15

    Phosphatidylinositol 4,5-biphosphate (PIP2) is critical for T lymphocyte activation serving as a substrate for the generation of second messengers and the remodeling of actin cytoskeleton necessary for the clustering of lipid rafts, TCR, and costimulatory receptors toward the T:APC interface. Spatiotemporal analysis of PIP2 synthesis in T lymphocytes suggested that distinct isoforms of the main PIP2-generating enzyme, phosphatidylinositol 4-phosphate 5-kinase (PIP5K), play a differential role on the basis of their distinct localization. In this study, we analyze the contribution of PIP5Kβ to T cell activation and show that CD28 induces the recruitment of PIP5Kβ to the immunological synapse, where it regulates filamin A and lipid raft accumulation, as well as T cell activation, in a nonredundant manner. Finally, we found that Vav1 and the C-terminal 83 aa of PIP5Kβ are pivotal for the PIP5Kβ regulatory functions in response to CD28 stimulation.

  5. Lovastatin-Induced Phosphatidylinositol-4-Phosphate 5-Kinase Diffusion from Microvilli Stimulates ROMK Channels

    PubMed Central

    Liu, Bing-Chen; Yang, Li-Li; Lu, Xiao-Yu; Song, Xiang; Li, Xue-Chen; Chen, Guangping; Li, Yichao; Yao, Xincheng; Humphrey, Donald R.; Eaton, Douglas C.

    2015-01-01

    We recently showed that lovastatin attenuates cyclosporin A (CsA)-induced damage of cortical collecting duct (CCD) principal cells by reducing intracellular cholesterol. Previous studies showed that, in cell expression models or artificial membranes, exogenous cholesterol directly inhibits inward rectifier potassium channels, including Kir1.1 (Kcnj1; the gene locus for renal outer medullary K+ [ROMK1] channels). Therefore, we hypothesized that lovastatin might stimulate ROMK1 by reducing cholesterol in CCD cells. Western blots showed that mpkCCDc14 cells express ROMK1 channels with molecular masses that approximate the molecular masses of ROMK1 in renal tubules detected before and after treatment with DTT. Confocal microscopy showed that ROMK1 channels were not in the microvilli, where cholesterol-rich lipid rafts are located, but rather, the planar regions of the apical membrane of mpkCCDc14 cells. Furthermore, phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], an activator of ROMK channels, was detected mainly in the microvilli under resting conditions along with the kinase responsible for PI(4,5)P2 synthesis, phosphatidylinositol-4-phosphate 5-kinase, type I γ [PI(4)P5K I γ], which may explain the low basal open probability and increased sensitivity to tetraethylammonium observed here for this channel. Notably, lovastatin induced PI(4)P5K I γ diffusion into planar regions and elevated PI(4,5)P2 and ROMK1 open probability in these regions through a cholesterol-associated mechanism. However, exogenous cholesterol alone did not induce these effects. These results suggest that lovastatin stimulates ROMK1 channels, at least in part, by inducing PI(4,5)P2 synthesis in planar regions of the renal CCD cell apical membrane, suggesting that lovastatin could reduce cyclosporin-induced nephropathy and associated hyperkalemia. PMID:25349201

  6. Lovastatin-Induced Phosphatidylinositol-4-Phosphate 5-Kinase Diffusion from Microvilli Stimulates ROMK Channels.

    PubMed

    Liu, Bing-Chen; Yang, Li-Li; Lu, Xiao-Yu; Song, Xiang; Li, Xue-Chen; Chen, Guangping; Li, Yichao; Yao, Xincheng; Humphrey, Donald R; Eaton, Douglas C; Shen, Bao-Zhong; Ma, He-Ping

    2015-07-01

    We recently showed that lovastatin attenuates cyclosporin A (CsA)-induced damage of cortical collecting duct (CCD) principal cells by reducing intracellular cholesterol. Previous studies showed that, in cell expression models or artificial membranes, exogenous cholesterol directly inhibits inward rectifier potassium channels, including Kir1.1 (Kcnj1; the gene locus for renal outer medullary K(+) [ROMK1] channels). Therefore, we hypothesized that lovastatin might stimulate ROMK1 by reducing cholesterol in CCD cells. Western blots showed that mpkCCDc14 cells express ROMK1 channels with molecular masses that approximate the molecular masses of ROMK1 in renal tubules detected before and after treatment with DTT. Confocal microscopy showed that ROMK1 channels were not in the microvilli, where cholesterol-rich lipid rafts are located, but rather, the planar regions of the apical membrane of mpkCCDc14 cells. Furthermore, phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], an activator of ROMK channels, was detected mainly in the microvilli under resting conditions along with the kinase responsible for PI(4,5)P2 synthesis, phosphatidylinositol-4-phosphate 5-kinase, type I γ [PI(4)P5K I γ], which may explain the low basal open probability and increased sensitivity to tetraethylammonium observed here for this channel. Notably, lovastatin induced PI(4)P5K I γ diffusion into planar regions and elevated PI(4,5)P2 and ROMK1 open probability in these regions through a cholesterol-associated mechanism. However, exogenous cholesterol alone did not induce these effects. These results suggest that lovastatin stimulates ROMK1 channels, at least in part, by inducing PI(4,5)P2 synthesis in planar regions of the renal CCD cell apical membrane, suggesting that lovastatin could reduce cyclosporin-induced nephropathy and associated hyperkalemia. PMID:25349201

  7. Phosphatidylinositol 4-phosphate 5-kinase α activation critically contributes to CD28-dependent signaling responses.

    PubMed

    Muscolini, Michela; Camperio, Cristina; Capuano, Cristina; Caristi, Silvana; Piccolella, Enza; Galandrini, Ricciarda; Tuosto, Loretta

    2013-05-15

    CD28 is one of the most relevant costimulatory receptors that deliver both TCR-dependent and TCR-independent signals regulating a wide range of signaling pathways crucial for cytokine and chemokine gene expressions, T cell survival, and proliferation. Most of the CD28-dependent signaling functions are initiated by the recruitment and activation of class IA PI3Ks, which catalyze the conversion of phosphatidylinositol 4,5-biphosphate (PIP2) into phosphatidylinositol 3,4,5-triphosphate, thus generating the docking sites for key signaling proteins. Hence, PIP2 is a crucial substrate in driving the PI3K downstream signaling pathways, and PIP2 turnover may be an essential regulatory step to ensure the activation of PI3K following CD28 engagement. Despite some data evidence that CD28 augments TCR-induced turnover of PIP2, its direct role in regulating PIP2 metabolism has never been assessed. In this study, we show that CD28 regulates PIP2 turnover by recruiting and activating phosphatidylinositol 4-phosphate 5-kinases α (PIP5Kα) in human primary CD4(+) T lymphocytes. This event leads to the neosynthesis of PIP2 and to its consumption by CD28-activated PI3K. We also evidenced that PIP5Kα activation is required for both CD28 unique signals regulating IL-8 gene expression as well as for CD28/TCR-induced Ca(2+) mobilization, NF-AT nuclear translocation, and IL-2 gene transcription. Our findings elucidate a novel mechanism that involves PIP5Kα as a key modulator of CD28 costimulatory signals.

  8. Phosphatidylinositol 4-phosphate 5-kinase α facilitates Toll-like receptor 4-mediated microglial inflammation through regulation of the Toll/interleukin-1 receptor domain-containing adaptor protein (TIRAP) location.

    PubMed

    Nguyen, Tu Thi Ngoc; Kim, Yong Min; Kim, T Doohun; Le, Oanh Thi Tu; Kim, Jae Jin; Kang, Ho Chul; Hasegawa, Hiroshi; Kanaho, Yasunori; Jou, Ilo; Lee, Sang Yoon

    2013-02-22

    Phosphatidylinositol (PI) 4,5-bisphosphate (PIP(2)), generated by PI 4-phosphate 5-kinase (PIP5K), regulates many critical cellular events. PIP(2) is also known to mediate plasma membrane localization of the Toll/IL-1 receptor domain-containing adaptor protein (TIRAP), required for the MyD88-dependent Toll-like receptor (TLR) 4 signaling pathway. Microglia are the primary immune competent cells in brain tissue, and TLR4 is important for microglial activation. However, a functional role for PIP5K and PIP(2) in TLR4-dependent microglial activation remains unclear. Here, we knocked down PIP5Kα, a PIP5K isoform, in a BV2 microglial cell line using stable expression of lentiviral shRNA constructs or siRNA transfection. PIP5Kα knockdown significantly suppressed induction of inflammatory mediators, including IL-6, IL-1β, and nitric oxide, by lipopolysaccharide. PIP5Kα knockdown also attenuated signaling events downstream of TLR4 activation, including p38 MAPK and JNK phosphorylation, NF-κB p65 nuclear translocation, and IκB-α degradation. Complementation of the PIP5Kα knockdown cells with wild type but not kinase-dead PIP5Kα effectively restored the LPS-mediated inflammatory response. We found that PIP5Kα and TIRAP colocalized at the cell surface and interacted with each other, whereas kinase-dead PIP5Kα rendered TIRAP soluble. Furthermore, in LPS-stimulated control cells, plasma membrane PIP(2) increased and subsequently declined, and TIRAP underwent bi-directional translocation between the membrane and cytosol, which temporally correlated with the changes in PIP(2). In contrast, PIP5Kα knockdown that reduced PIP(2) levels disrupted TIRAP membrane targeting by LPS. Together, our results suggest that PIP5Kα promotes TLR4-associated microglial inflammation by mediating PIP(2)-dependent recruitment of TIRAP to the plasma membrane.

  9. Nuclear pool of phosphatidylinositol 4 phosphate 5 kinase 1α is modified by polySUMO-2 during apoptosis

    SciTech Connect

    Chakrabarti, Rajarshi; Bhowmick, Debajit; Bhargava, Varsha; Bhar, Kaushik; Siddhanta, Anirban

    2013-09-20

    Highlights: •Nuclear pool of PIP5K is SUMOylated. •Enhancement of SUMOylated nuclear PIP5K during apoptosis. •Nuclear PIP5K is modified by polySUMO-1 during apoptosis. •Nuclear PIP5K is modified by polySUMO-2 chain during apoptosis. -- Abstract: Phosphatidylinositol 4 phosphate 5 kinase 1α (PIP5K) is mainly localized in the cytosol and plasma membrane. Studies have also indicated its prominent association with nuclear speckles. The exact nature of this nuclear pool of PIP5K is not clear. Using biochemical and microscopic techniques, we have demonstrated that the nuclear pool of PIP5K is modified by SUMO-1 in HEK-293 cells stably expressing PIP5K. Moreover, this SUMOylated pool of PIP5K increased during apoptosis. PolySUMO-2 chain conjugated PIP5K was detected by pull-down experiment using affinity-tagged RNF4, a polySUMO-2 binding protein, during late apoptosis.

  10. Complementation of growth factor receptor-dependent mitogenic signaling by a truncated type I phosphatidylinositol 4-phosphate 5-kinase.

    PubMed

    Davis, J N; Rock, C O; Cheng, M; Watson, J B; Ashmun, R A; Kirk, H; Kay, R J; Roussel, M F

    1997-12-01

    Substitution of phenylalanine for tyrosine at codon 809 (Y809F) of the human colony-stimulating factor 1 (CSF-1) receptor (CSF-1R) impairs ligand-stimulated tyrosine kinase activity, prevents induction of c-MYC and cyclin D1 genes, and blocks CSF-1-dependent progression through the G1 phase of the cell cycle. We devised an unbiased genetic screen to isolate genes that restore the ability of CSF-1 to stimulate growth in cells that express mutant CSF-1R (Y809F). This screen led us to identify a truncated form of the murine type Ibeta phosphatidylinositol 4-phosphate 5-kinase (mPIP5K-Ibeta). This truncated protein lacks residues 1 to 238 of mPIP5K-Ibeta and is catalytically inactive. When we transfected cells expressing CSF-1R (Y809F) with mPIP5K-Ibeta (delta1-238), CSF-1-dependent induction of c-MYC and cyclin D1 was restored and ligand-dependent cell proliferation was sustained. CSF-1 normally triggers the rapid disappearance of CSF-1R (Y809F) from the cell surface; however, transfection of cells with mPIP5K-Ibeta (delta1-238) stabilized CSF-1R (Y809F) expression on the cell surface, resulting in elevated levels of ligand-activated CSF-1R (Y809F). These results suggest a role for PIP5K-Ibeta in receptor endocytosis and that the truncated enzyme compensated for a mitogenically defective CSF-1R by interfering with this process.

  11. Protein Kinase D1 regulates focal adhesion dynamics and cell adhesion through Phosphatidylinositol-4-phosphate 5-kinase type-l γ

    PubMed Central

    Durand, Nisha; Bastea, Ligia I.; Long, Jason; Döppler, Heike; Ling, Kun; Storz, Peter

    2016-01-01

    Focal adhesions (FAs) are highly dynamic structures that are assembled and disassembled on a continuous basis. The balance between the two processes mediates various aspects of cell behavior, ranging from cell adhesion and spreading to directed cell migration. The turnover of FAs is regulated at multiple levels and involves a variety of signaling molecules and adaptor proteins. In the present study, we show that in response to integrin engagement, a subcellular pool of Protein Kinase D1 (PKD1) localizes to the FAs. PKD1 affects FAs by decreasing turnover and promoting maturation, resulting in enhanced cell adhesion. The effects of PKD1 are mediated through direct phosphorylation of FA-localized phosphatidylinositol-4-phosphate 5-kinase type-l γ (PIP5Klγ) at serine residue 448. This phosphorylation occurs in response to Fibronectin-RhoA signaling and leads to a decrease in PIP5Klγs’ lipid kinase activity and binding affinity for Talin. Our data reveal a novel function for PKD1 as a regulator of FA dynamics and by identifying PIP5Klγ as a novel PKD1 substrate provide mechanistic insight into this process. PMID:27775029

  12. Phosphatidylinositol 4-phosphate 5-kinase reduces cell surface expression of the epithelial sodium channel (ENaC) in cultured collecting duct cells.

    PubMed

    Weixel, Kelly M; Edinger, Robert S; Kester, Lauren; Guerriero, Christopher J; Wang, Huamin; Fang, Liang; Kleyman, Thomas R; Welling, Paul A; Weisz, Ora A; Johnson, John P

    2007-12-14

    Ubiquitination of ENaC subunits has been shown to negatively regulate the cell surface expression of ENaC channels. We have previously demonstrated that epsin links ubiquitinated ENaC to clathrin adaptors for clathrin-mediated endocytosis. Epsin is thought to directly modify the curvature of membranes upon binding to phosphatidylinositol 4,5-bisphosphate (PIP2) where it recruits clathrin and stimulates lattice assembly. Murine phosphatidylinositol 4-phosphate 5-kinase alpha (PI5KIalpha) has been shown to enhance endocytosis in a PIP2-dependent manner. We tested the hypothesis that PI5KIalpha-mediated PIP2 production would negatively regulate ENaC current by enhancing epsin-mediated endocytosis of the channel. Expression of PI5KIalpha decreased ENaC currents in Xenopus oocytes by 80%, entirely because of a decrease in cell surface ENaC levels. Catalytically inactive mutants of PI5Kalpha had no effect on ENaC activity. Expression of the PIP2 binding region of epsin increased ENaC current in oocytes, an effect completely reversed by co-expression of PI5KIalpha. Overexpression of epsin reduced amiloride-sensitive current in CCD cells. Overexpression of PI5KIalpha enhanced membrane PIP2 levels and reduced apical surface expression of ENaC in CCD cells, down-regulating amiloride-sensitive current. Knockdown of PI5KIalpha with isoform-specific siRNA resulted in a 4-fold enhancement of ENaC activity. PI5KIalpha localized exclusively to the apical plasma membrane domain when overexpressed in mouse CCD cells, consistent for a role in regulating PIP2 production at the apical plasma membrane. We conclude that membrane turnover events regulating ENaC surface expression and activity in oocytes and CCD cells can be regulated by PI5KIalpha. PMID:17940289

  13. Phosphatidylinositol-4-phosphate 5-Kinase 1α Modulates Ribosomal RNA Gene Silencing through Its Interaction with Histone H3 Lysine 9 Trimethylation and Heterochromatin Protein HP1-α*

    PubMed Central

    Chakrabarti, Rajarshi; Sanyal, Sulagna; Ghosh, Amit; Bhar, Kaushik; Das, Chandrima; Siddhanta, Anirban

    2015-01-01

    Phosphoinositide signaling has been implicated in the regulation of numerous cellular processes including cytoskeletal dynamics, cellular motility, vesicle trafficking, and gene transcription. Studies have also shown that nuclear phosphoinositide(s) regulates processes such as mRNA export, cell cycle progression, gene transcription, and DNA repair. We have shown previously that the nuclear form of phosphatidylinositol-4-phosphate 5-kinase 1α (PIP5K), the enzyme responsible for phosphatidylinositol 4,5-bisphosphate synthesis, is modified by small ubiquitin-like modifier (SUMO)-1. In this study, we have shown that due to the site-specific Lys to Ala mutations of PIP5K at Lys-244 and Lys-490, it is unable to localize in the nucleus and nucleolus, respectively. Furthermore, by using chromatin immunoprecipitation assays, we have observed that PIP5K associates with the chromatin silencing complex constituted of H3K9me3 and heterochromatin protein 1α at multiple ribosomal DNA (rDNA) loci. These interactions followed a definite cyclical pattern of occupancy (mostly G1) and release from the rDNA loci (G1/S) throughout the cell cycle. Moreover, the immunoprecipitation results clearly demonstrate that PIP5K SUMOylated at Lys-490 interacts with components of the chromatin silencing machinery, H3K9me3 and heterochromatin protein 1α. However, PIP5K does not interact with the gene activation signature protein H3K4me3. This study, for the first time, demonstrates that PIP5K, an enzyme actively associated with lipid modification pathway, has additional roles in rDNA silencing. PMID:26157143

  14. Lipids in salicylic acid-mediated defense in plants: focusing on the roles of phosphatidic acid and phosphatidylinositol 4-phosphate

    PubMed Central

    Zhang, Qiong; Xiao, Shunyuan

    2015-01-01

    Plants have evolved effective defense strategies to protect themselves from various pathogens. Salicylic acid (SA) is an essential signaling molecule that mediates pathogen-triggered signals perceived by different immune receptors to induce downstream defense responses. While many proteins play essential roles in regulating SA signaling, increasing evidence also supports important roles for signaling phospholipids in this process. In this review, we collate the experimental evidence in support of the regulatory roles of two phospholipids, phosphatidic acid (PA), and phosphatidylinositol 4-phosphate (PI4P), and their metabolizing enzymes in plant defense, and examine the possible mechanistic interaction between phospholipid signaling and SA-dependent immunity with a particular focus on the immunity-stimulated biphasic PA production that is reminiscent of and perhaps mechanistically connected to the biphasic reactive oxygen species (ROS) generation and SA accumulation during defense activation. PMID:26074946

  15. Phosphatidylinositol 4-phosphate 5-kinases 1 and 2 are involved in the regulation of vacuole morphology during Arabidopsis thaliana pollen development.

    PubMed

    Ugalde, José-Manuel; Rodriguez-Furlán, Cecilia; Rycke, Riet De; Norambuena, Lorena; Friml, Jiří; León, Gabriel; Tejos, Ricardo

    2016-09-01

    The pollen grains arise after meiosis of pollen mother cells within the anthers. A series of complex structural changes follows, generating mature pollen grains capable of performing the double fertilization of the female megasporophyte. Several signaling molecules, including hormones and lipids, have been involved in the regulation and appropriate control of pollen development. Phosphatidylinositol 4-phophate 5-kinases (PIP5K), which catalyze the biosynthesis of the phosphoinositide PtdIns(4,5)P2, are important for tip polar growth of root hairs and pollen tubes, embryo development, vegetative plant growth, and responses to the environment. Here, we report a role of PIP5Ks during microgametogenesis. PIP5K1 and PIP5K2 are expressed during early stages of pollen development and their transcriptional activity respond to auxin in pollen grains. Early male gametophytic lethality to certain grade was observed in both pip5k1(-/-) and pip5k2(-/-) single mutants. The number of pip5k mutant alleles is directly related to the frequency of aborted pollen grains suggesting the two genes are involved in the same function. Indeed PIP5K1 and PIP5K2 are functionally redundant since homozygous double mutants did not render viable pollen grains. The loss of function of PIP5K1 and PIP5K2results in defects in vacuole morphology in pollen at the later stages and epidermal root cells. Our results show that PIP5K1, PIP5K2 and phosphoinositide signaling are important cues for early developmental stages and vacuole formation during microgametogenesis. PMID:27457979

  16. Imaging phosphatidylinositol 4-phosphate dynamics in living plant cells.

    PubMed

    Vermeer, Joop E M; Thole, Julie M; Goedhart, Joachim; Nielsen, Erik; Munnik, Teun; Gadella, Theodorus W J

    2009-01-01

    Polyphosphoinositides represent a minor group of phospholipids, accounting for less than 1% of the total. Despite their low abundance, these molecules have been implicated in various signalling and membrane trafficking events. Phosphatidylinositol 4-phosphate (PtdIns4P) is the most abundant polyphosphoinositide. (32)Pi-labelling studies have shown that the turnover of PtdIns4P is rapid, but little is known about where in the cell or plant this occurs. Here, we describe the use of a lipid biosensor that monitors PtdIns4P dynamics in living plant cells. The biosensor consists of a fusion between a fluorescent protein and a lipid-binding domain that specifically binds PtdIns4P, i.e. the pleckstrin homology domain of the human protein phosphatidylinositol-4-phosphate adaptor protein-1 (FAPP1). YFP-PH(FAPP1) was expressed in four plant systems: transiently in cowpea protoplasts, and stably in tobacco BY-2 cells, Medicago truncatula roots and Arabidopsis thaliana seedlings. All systems allowed YFP-PH(FAPP1) expression without detrimental effects. Two distinct fluorescence patterns were observed: labelling of motile punctate structures and the plasma membrane. Co-expression studies with organelle markers revealed strong co-labelling with the Golgi marker STtmd-CFP, but not with the endocytic/pre-vacuolar marker GFP-AtRABF2b. Co-expression with the Ptdins3P biosensor YFP-2 x FYVE revealed totally different localization patterns. During cell division, YFP-PH(FAPP1) showed strong labelling of the cell plate, but PtdIns3P was completely absent from the newly formed cell membrane. In root hairs of M. truncatula and A. thaliana, a clear PtdIns4P gradient was apparent in the plasma membrane, with the highest concentration in the tip. This only occurred in growing root hairs, indicating a role for PtdIns4P in tip growth.

  17. Phosphatidylinositol 4-Phosphate 5-Kinases in the Regulation of T Cell Activation

    PubMed Central

    Porciello, Nicla; Kunkl, Martina; Viola, Antonella; Tuosto, Loretta

    2016-01-01

    Phosphatidylinositol 4,5-biphosphate kinases (PIP5Ks) are critical regulators of T cell activation being the main enzymes involved in the synthesis of phosphatidylinositol 4,5-biphosphate (PIP2). PIP2 is indeed a pivotal regulator of the actin cytoskeleton, thus controlling T cell polarization and migration, stable adhesion to antigen-presenting cells, spatial organization of the immunological synapse, and co-stimulation. Moreover, PIP2 also serves as a precursor for the second messengers inositol triphosphate, diacylglycerol, and phosphatidylinositol 3,4,5-triphosphate, which are essential for the activation of signaling pathways regulating cytokine production, cell cycle progression, survival, metabolism, and differentiation. Here, we discuss the impact of PIP5Ks on several T lymphocyte functions with a specific focus on the role of CD28 co-stimulation in PIP5K compartimentalization and activation. PMID:27242793

  18. Phosphatidylinositol 4-Phosphate 5-Kinases in the Regulation of T Cell Activation.

    PubMed

    Porciello, Nicla; Kunkl, Martina; Viola, Antonella; Tuosto, Loretta

    2016-01-01

    Phosphatidylinositol 4,5-biphosphate kinases (PIP5Ks) are critical regulators of T cell activation being the main enzymes involved in the synthesis of phosphatidylinositol 4,5-biphosphate (PIP2). PIP2 is indeed a pivotal regulator of the actin cytoskeleton, thus controlling T cell polarization and migration, stable adhesion to antigen-presenting cells, spatial organization of the immunological synapse, and co-stimulation. Moreover, PIP2 also serves as a precursor for the second messengers inositol triphosphate, diacylglycerol, and phosphatidylinositol 3,4,5-triphosphate, which are essential for the activation of signaling pathways regulating cytokine production, cell cycle progression, survival, metabolism, and differentiation. Here, we discuss the impact of PIP5Ks on several T lymphocyte functions with a specific focus on the role of CD28 co-stimulation in PIP5K compartimentalization and activation.

  19. Phosphatidylinositol 4-Phosphate 5-Kinases in the Regulation of T Cell Activation.

    PubMed

    Porciello, Nicla; Kunkl, Martina; Viola, Antonella; Tuosto, Loretta

    2016-01-01

    Phosphatidylinositol 4,5-biphosphate kinases (PIP5Ks) are critical regulators of T cell activation being the main enzymes involved in the synthesis of phosphatidylinositol 4,5-biphosphate (PIP2). PIP2 is indeed a pivotal regulator of the actin cytoskeleton, thus controlling T cell polarization and migration, stable adhesion to antigen-presenting cells, spatial organization of the immunological synapse, and co-stimulation. Moreover, PIP2 also serves as a precursor for the second messengers inositol triphosphate, diacylglycerol, and phosphatidylinositol 3,4,5-triphosphate, which are essential for the activation of signaling pathways regulating cytokine production, cell cycle progression, survival, metabolism, and differentiation. Here, we discuss the impact of PIP5Ks on several T lymphocyte functions with a specific focus on the role of CD28 co-stimulation in PIP5K compartimentalization and activation. PMID:27242793

  20. Phosphatidylinositol(4,5)bisphosphate and Phosphatidylinositol(4)phosphate in Plant Tissues 1

    PubMed Central

    Irvine, R. F.; Letcher, A. J.; Lander, D. J.; Drøbak, B. K.; Dawson, A. P.; Musgrave, A.

    1989-01-01

    Pea (Pisum sativum) leaf discs or swimming suspensions of Chlamydomonas eugametos were radiolabeled with [3H]myo-inositol or [32P]Pi and the lipids were extracted, deacylated, and their glycerol moieties removed. The resulting inositol trisphosphate and bisphosphate fractions were examined by periodate degradation, reduction and dephosphorylation, or by incubation with human red cell membranes. Their likely structures were identified as d-myo-inositol(1,4,5)trisphosphate and d-myo-inositol(1,4,)-bisphosphate. It is concluded that plants contain phosphatidylinositol(4)phosphate and phosphatidylinositol(4,5)bisphosphate; no other polyphosphoinositides were detected. PMID:16666637

  1. Phosphatidylinositol(4,5)bisphosphate and phosphatidylinositol(4)phosphate in plant tissues. [Pisum sativum

    SciTech Connect

    Irvine, R.F.; Letcher, A.J.; Lander, D.J. ); Dawson, A.P. ); Musgrave, A. ); Drobak, B.K. )

    1989-03-01

    Pea (Pisum sativum) leaf discs or swimming suspensions of Chlamydomonas eugametos were radiolabeled with ({sup 3}H)myo-inositol or ({sup 32}P)Pi and the lipids were extracted, deacylated, and their glycerol moieties removed. The resulting inositol trisphosphate and bisphosphate fractions were examined by periodate degradation, reduction and dephosphorylation, or by incubation with human red cell membranes. Their likely structures were identified as D-myo-inositol(1,4,5)trisphosphate and D-myo-inositol(1,4,)-bisphosphate. It is concluded that plants contain phosphatidylinositol(4)phosphate and phosphatidylinositol(4,5)bisphosphate; no other polyphosphoinositides were detected.

  2. Histones Cause Aggregation and Fusion of Lipid Vesicles Containing Phosphatidylinositol-4-Phosphate

    PubMed Central

    Lete, Marta G.; Sot, Jesus; Gil, David; Valle, Mikel; Medina, Milagros; Goñi, Felix M.; Alonso, Alicia

    2015-01-01

    In a previous article, we demonstrated that histones (H1 or histone octamers) interact with negatively charged bilayers and induce extensive aggregation of vesicles containing phosphatidylinositol-4-phosphate (PIP) and, to a lesser extent, vesicles containing phosphatidylinositol (PI). Here, we found that vesicles containing PIP, but not those containing PI, can undergo fusion induced by histones. Fusion was demonstrated through the observation of intervesicular mixing of total lipids and inner monolayer lipids, and by ultrastructural and confocal microscopy studies. Moreover, in both PI- and PIP-containing vesicles, histones caused permeabilization and release of vesicular aqueous contents, but the leakage mechanism was different (all-or-none for PI and graded release for PIP vesicles). These results indicate that histones could play a role in the remodeling of the nuclear envelope that takes place during the mitotic cycle. PMID:25692591

  3. Local control of phosphatidylinositol 4-phosphate signaling in the Golgi apparatus by Vps74 and Sac1 phosphoinositide phosphatase

    PubMed Central

    Wood, Christopher S.; Hung, Chia-Sui; Huoh, Yu-San; Mousley, Carl J.; Stefan, Christopher J.; Bankaitis, Vytas; Ferguson, Kathryn M.; Burd, Christopher G.

    2012-01-01

    In the Golgi apparatus, lipid homeostasis pathways are coordinated with the biogenesis of cargo transport vesicles by phosphatidylinositol 4-kinases (PI4Ks) that produce phosphatidylinositol 4-phosphate (PtdIns4P), a signaling molecule that is recognized by downstream effector proteins. Quantitative analysis of the intra-Golgi distribution of a PtdIns4P reporter protein confirms that PtdIns4P is enriched on the trans-Golgi cisterna, but surprisingly, Vps74 (the orthologue of human GOLPH3), a PI4K effector required to maintain residence of a subset of Golgi proteins, is distributed with the opposite polarity, being most abundant on cis and medial cisternae. Vps74 binds directly to the catalytic domain of Sac1 (KD = 3.8 μM), the major PtdIns4P phosphatase in the cell, and PtdIns4P is elevated on medial Golgi cisternae in cells lacking Vps74 or Sac1, suggesting that Vps74 is a sensor of PtdIns4P level on medial Golgi cisternae that directs Sac1-mediated dephosphosphorylation of this pool of PtdIns4P. Consistent with the established role of Sac1 in the regulation of sphingolipid biosynthesis, complex sphingolipid homeostasis is perturbed in vps74Δ cells. Mutant cells lacking complex sphingolipid biosynthetic enzymes fail to properly maintain residence of a medial Golgi enzyme, and cells lacking Vps74 depend critically on complex sphingolipid biosynthesis for growth. The results establish additive roles of Vps74-mediated and sphingolipid-dependent sorting of Golgi residents. PMID:22553352

  4. Phosphatidylinositol-4-phosphate-dependent membrane traffic is critical for fungal filamentous growth.

    PubMed

    Ghugtyal, Vikram; Garcia-Rodas, Rocio; Seminara, Agnese; Schaub, Sébastien; Bassilana, Martine; Arkowitz, Robert Alan

    2015-07-14

    The phospholipid phosphatidylinositol-4-phosphate [PI(4)P], generated at the Golgi and plasma membrane, has been implicated in many processes, including membrane traffic, yet its role in cell morphology changes, such as the budding to filamentous growth transition, is unknown. We show that Golgi PI(4)P is required for such a transition in the human pathogenic fungus Candida albicans. Quantitative analyses of membrane traffic revealed that PI(4)P is required for late Golgi and secretory vesicle dynamics and targeting and, as a result, is important for the distribution of a multidrug transporter and hence sensitivity to antifungal drugs. We also observed that plasma membrane PI(4)P, which we show is functionally distinct from Golgi PI(4)P, forms a steep gradient concomitant with filamentous growth, despite uniform plasma membrane PI-4-kinase distribution. Mathematical modeling indicates that local PI(4)P generation and hydrolysis by phosphatases are crucial for this gradient. We conclude that PI(4)P-regulated membrane dynamics are critical for morphology changes.

  5. Phosphatidylinositol-4-phosphate-dependent membrane traffic is critical for fungal filamentous growth

    PubMed Central

    Ghugtyal, Vikram; Garcia-Rodas, Rocio; Seminara, Agnese; Schaub, Sébastien; Bassilana, Martine; Arkowitz, Robert Alan

    2015-01-01

    The phospholipid phosphatidylinositol-4-phosphate [PI(4)P], generated at the Golgi and plasma membrane, has been implicated in many processes, including membrane traffic, yet its role in cell morphology changes, such as the budding to filamentous growth transition, is unknown. We show that Golgi PI(4)P is required for such a transition in the human pathogenic fungus Candida albicans. Quantitative analyses of membrane traffic revealed that PI(4)P is required for late Golgi and secretory vesicle dynamics and targeting and, as a result, is important for the distribution of a multidrug transporter and hence sensitivity to antifungal drugs. We also observed that plasma membrane PI(4)P, which we show is functionally distinct from Golgi PI(4)P, forms a steep gradient concomitant with filamentous growth, despite uniform plasma membrane PI-4-kinase distribution. Mathematical modeling indicates that local PI(4)P generation and hydrolysis by phosphatases are crucial for this gradient. We conclude that PI(4)P-regulated membrane dynamics are critical for morphology changes. PMID:26124136

  6. The Salmonella effector SteA binds phosphatidylinositol 4-phosphate for subcellular targeting within host cells.

    PubMed

    Domingues, Lia; Ismail, Ahmad; Charro, Nuno; Rodríguez-Escudero, Isabel; Holden, David W; Molina, María; Cid, Víctor J; Mota, Luís Jaime

    2016-07-01

    Many bacterial pathogens use specialized secretion systems to deliver virulence effector proteins into eukaryotic host cells. The function of these effectors depends on their localization within infected cells, but the mechanisms determining subcellular targeting of each effector are mostly elusive. Here, we show that the Salmonella type III secretion effector SteA binds specifically to phosphatidylinositol 4-phosphate [PI(4)P]. Ectopically expressed SteA localized at the plasma membrane (PM) of eukaryotic cells. However, SteA was displaced from the PM of Saccharomyces cerevisiae in mutants unable to synthesize the local pool of PI(4)P and from the PM of HeLa cells after localized depletion of PI(4)P. Moreover, in infected cells, bacterially translocated or ectopically expressed SteA localized at the membrane of the Salmonella-containing vacuole (SCV) and to Salmonella-induced tubules; using the PI(4)P-binding domain of the Legionella type IV secretion effector SidC as probe, we found PI(4)P at the SCV membrane and associated tubules throughout Salmonella infection of HeLa cells. Both binding of SteA to PI(4)P and the subcellular localization of ectopically expressed or bacterially translocated SteA were dependent on a lysine residue near the N-terminus of the protein. Overall, this indicates that binding of SteA to PI(4)P is necessary for its localization within host cells.

  7. INTRACELLULAR TRANSPORT. Phosphatidylserine transport by ORP/Osh proteins is driven by phosphatidylinositol 4-phosphate.

    PubMed

    Moser von Filseck, Joachim; Čopič, Alenka; Delfosse, Vanessa; Vanni, Stefano; Jackson, Catherine L; Bourguet, William; Drin, Guillaume

    2015-07-24

    In eukaryotic cells, phosphatidylserine (PS) is synthesized in the endoplasmic reticulum (ER) but is highly enriched in the plasma membrane (PM), where it contributes negative charge and to specific recruitment of signaling proteins. This distribution relies on transport mechanisms whose nature remains elusive. Here, we found that the PS transporter Osh6p extracted phosphatidylinositol 4-phosphate (PI4P) and exchanged PS for PI4P between two membranes. We solved the crystal structure of Osh6p:PI4P complex and demonstrated that the transport of PS by Osh6p depends on PI4P recognition in vivo. Finally, we showed that the PI4P-phosphatase Sac1p, by maintaining a PI4P gradient at the ER/PM interface, drove PS transport. Thus, PS transport by oxysterol-binding protein-related protein (ORP)/oxysterol-binding homology (Osh) proteins is fueled by PI4P metabolism through PS/PI4P exchange cycles.

  8. Osh4p exchanges sterols for phosphatidylinositol 4-phosphate between lipid bilayers

    PubMed Central

    de Saint-Jean, Maud; Delfosse, Vanessa; Douguet, Dominique; Chicanne, Gaëtan; Payrastre, Bernard; Bourguet, William

    2011-01-01

    Osh/Orp proteins transport sterols between organelles and are involved in phosphoinositide metabolism. The link between these two aspects remains elusive. Using novel assays, we address the influence of membrane composition on the ability of Osh4p/Kes1p to extract, deliver, or transport dehydroergosterol (DHE). Surprisingly, phosphatidylinositol 4-phosphate (PI(4)P) specifically inhibited DHE extraction because PI(4)P was itself efficiently extracted by Osh4p. We solve the structure of the Osh4p–PI(4)P complex and reveal how Osh4p selectively substitutes PI(4)P for sterol. Last, we show that Osh4p quickly exchanges DHE for PI(4)P and, thereby, can transport these two lipids between membranes along opposite routes. These results suggest a model in which Osh4p transports sterol from the ER to late compartments pinpointed by PI(4)P and, in turn, transports PI(4)P backward. Coupled to PI(4)P metabolism, this transport cycle would create sterol gradients. Because the residues that recognize PI(4)P are conserved in Osh4p homologues, other Osh/Orp are potential sterol/phosphoinositol phosphate exchangers. PMID:22162133

  9. West Nile virus replication requires fatty acid synthesis but is independent on phosphatidylinositol-4-phosphate lipids.

    PubMed

    Martín-Acebes, Miguel A; Blázquez, Ana-Belén; Jiménez de Oya, Nereida; Escribano-Romero, Estela; Saiz, Juan-Carlos

    2011-01-01

    West Nile virus (WNV) is a neurovirulent mosquito-borne flavivirus, which main natural hosts are birds but it also infects equines and humans, among other mammals. As in the case of other plus-stranded RNA viruses, WNV replication is associated to intracellular membrane rearrangements. Based on results obtained with a variety of viruses, different cellular processes have been shown to play important roles on these membrane rearrangements for efficient viral replication. As these processes are related to lipid metabolism, fatty acid synthesis, as well as generation of a specific lipid microenvironment enriched in phosphatidylinositol-4-phosphate (PI4P), has been associated to it in other viral models. In this study, intracellular membrane rearrangements following infection with a highly neurovirulent strain of WNV were addressed by means of electron and confocal microscopy. Infection of WNV, and specifically viral RNA replication, were dependent on fatty acid synthesis, as revealed by the inhibitory effect of cerulenin and C75, two pharmacological inhibitors of fatty acid synthase, a key enzyme of this process. However, WNV infection did not induce redistribution of PI4P lipids, and PI4P did not localize at viral replication complex. Even more, WNV multiplication was not inhibited by the use of the phosphatidylinositol-4-kinase inhibitor PIK93, while infection by the enterovirus Coxsackievirus B5 was reduced. Similar features were found when infection by other flavivirus, the Usutu virus (USUV), was analyzed. These features of WNV replication could help to design specific antiviral approaches against WNV and other related flaviviruses.

  10. Phosphatidylinositol-4-phosphate-dependent membrane traffic is critical for fungal filamentous growth.

    PubMed

    Ghugtyal, Vikram; Garcia-Rodas, Rocio; Seminara, Agnese; Schaub, Sébastien; Bassilana, Martine; Arkowitz, Robert Alan

    2015-07-14

    The phospholipid phosphatidylinositol-4-phosphate [PI(4)P], generated at the Golgi and plasma membrane, has been implicated in many processes, including membrane traffic, yet its role in cell morphology changes, such as the budding to filamentous growth transition, is unknown. We show that Golgi PI(4)P is required for such a transition in the human pathogenic fungus Candida albicans. Quantitative analyses of membrane traffic revealed that PI(4)P is required for late Golgi and secretory vesicle dynamics and targeting and, as a result, is important for the distribution of a multidrug transporter and hence sensitivity to antifungal drugs. We also observed that plasma membrane PI(4)P, which we show is functionally distinct from Golgi PI(4)P, forms a steep gradient concomitant with filamentous growth, despite uniform plasma membrane PI-4-kinase distribution. Mathematical modeling indicates that local PI(4)P generation and hydrolysis by phosphatases are crucial for this gradient. We conclude that PI(4)P-regulated membrane dynamics are critical for morphology changes. PMID:26124136

  11. The Clathrin Adaptor Gga2p Is a Phosphatidylinositol 4-phosphate Effector at the Golgi Exit

    PubMed Central

    Demmel, Lars; Gravert, Maike; Ercan, Ebru; Habermann, Bianca; Müller-Reichert, Thomas; Kukhtina, Viktoria; Haucke, Volker; Baust, Thorsten; Sohrmann, Marc; Kalaidzidis, Yannis; Klose, Christian; Beck, Mike; Peter, Matthias

    2008-01-01

    Phosphatidylinositol 4-phosphate (PI(4)P) is a key regulator of membrane transport required for the formation of transport carriers from the trans-Golgi network (TGN). The molecular mechanisms of PI(4)P signaling in this process are still poorly understood. In a search for PI(4)P effector molecules, we performed a screen for synthetic lethals in a background of reduced PI(4)P and found the gene GGA2. Our analysis uncovered a PI(4)P-dependent recruitment of the clathrin adaptor Gga2p to the TGN during Golgi-to-endosome trafficking. Gga2p recruitment to liposomes is stimulated both by PI(4)P and the small GTPase Arf1p in its active conformation, implicating these two molecules in the recruitment of Gga2p to the TGN, which ultimately controls the formation of clathrin-coated vesicles. PI(4)P binding occurs through a phosphoinositide-binding signature within the N-terminal VHS domain of Gga2p resembling a motif found in other clathrin interacting proteins. These data provide an explanation for the TGN-specific membrane recruitment of Gga2p. PMID:18287542

  12. West Nile Virus Replication Requires Fatty Acid Synthesis but Is Independent on Phosphatidylinositol-4-Phosphate Lipids

    PubMed Central

    Martín-Acebes, Miguel A.; Blázquez, Ana-Belén; Jiménez de Oya, Nereida; Escribano-Romero, Estela; Saiz, Juan-Carlos

    2011-01-01

    West Nile virus (WNV) is a neurovirulent mosquito-borne flavivirus, which main natural hosts are birds but it also infects equines and humans, among other mammals. As in the case of other plus-stranded RNA viruses, WNV replication is associated to intracellular membrane rearrangements. Based on results obtained with a variety of viruses, different cellular processes have been shown to play important roles on these membrane rearrangements for efficient viral replication. As these processes are related to lipid metabolism, fatty acid synthesis, as well as generation of a specific lipid microenvironment enriched in phosphatidylinositol-4-phosphate (PI4P), has been associated to it in other viral models. In this study, intracellular membrane rearrangements following infection with a highly neurovirulent strain of WNV were addressed by means of electron and confocal microscopy. Infection of WNV, and specifically viral RNA replication, were dependent on fatty acid synthesis, as revealed by the inhibitory effect of cerulenin and C75, two pharmacological inhibitors of fatty acid synthase, a key enzyme of this process. However, WNV infection did not induce redistribution of PI4P lipids, and PI4P did not localize at viral replication complex. Even more, WNV multiplication was not inhibited by the use of the phosphatidylinositol-4-kinase inhibitor PIK93, while infection by the enterovirus Coxsackievirus B5 was reduced. Similar features were found when infection by other flavivirus, the Usutu virus (USUV), was analyzed. These features of WNV replication could help to design specific antiviral approaches against WNV and other related flaviviruses. PMID:21949814

  13. Foot-and-mouth disease virus replicates independently of phosphatidylinositol 4-phosphate and type III phosphatidylinositol 4-kinases.

    PubMed

    Berryman, Stephen; Moffat, Katy; Harak, Christian; Lohmann, Volker; Jackson, Terry

    2016-08-01

    Picornaviruses form replication complexes in association with membranes in structures called replication organelles. Common themes to emerge from studies of picornavirus replication are the need for cholesterol and phosphatidylinositol 4-phosphate (PI4P). In infected cells, type III phosphatidylinositol 4-kinases (PI4KIIIs) generate elevated levels of PI4P, which is then exchanged for cholesterol at replication organelles. For the enteroviruses, replication organelles form at Golgi membranes in a process that utilizes PI4KIIIβ. Other picornaviruses, for example the cardioviruses, are believed to initiate replication at the endoplasmic reticulum and subvert PI4KIIIα to generate PI4P. Here we investigated the role of PI4KIII in foot-and-mouth disease virus (FMDV) replication. Our results showed that, in contrast to the enteroviruses and the cardioviruses, FMDV replication does not require PI4KIII (PI4KIIIα and PI4KIIIβ), and PI4P levels do not increase in FMDV-infected cells and PI4P is not seen at replication organelles. These results point to a unique requirement towards lipids at the FMDV replication membranes. PMID:27093462

  14. Molecular Basis of Phosphatidylinositol 4-Phosphate and ARF1 GTPase Recognition by the FAPP1 Pleckstrin Homology (PH) Domain

    SciTech Connect

    He, J.; Heroux, A.; Scott, J. L.; Roy, S.; Lenoir, M.; Overduin, M.; Stahelin, R. V.; Kutateladze, T. G.

    2011-05-27

    Four-phosphate-adaptor protein 1 (FAPP1) regulates secretory transport from the trans-Golgi network (TGN) to the plasma membrane. FAPP1 is recruited to the Golgi through binding of its pleckstrin homology (PH) domain to phosphatidylinositol 4-phosphate (PtdIns(4)P) and a small GTPase ADP-ribosylation factor 1 (ARF1). Despite the critical role of FAPP1 in membrane trafficking, the molecular basis of its dual function remains unclear. Here, we report a 1.9 {angstrom} resolution crystal structure of the FAPP1 PH domain and detail the molecular mechanisms of the PtdIns(4)P and ARF1 recognition. The FAPP1 PH domain folds into a seven-stranded {beta}-barrel capped by an {alpha}-helix at one edge, whereas the opposite edge is flanked by three loops and the {beta}4 and {beta}7 strands that form a lipid-binding pocket within the {beta}-barrel. The ARF1-binding site is located on the outer side of the {beta}-barrel as determined by NMR resonance perturbation analysis, mutagenesis, and measurements of binding affinities. The two binding sites have little overlap, allowing FAPP1 PH to associate with both ligands simultaneously and independently. Binding to PtdIns(4)P is enhanced in an acidic environment and is required for membrane penetration and tubulation activity of FAPP1, whereas the GTP-bound conformation of the GTPase is necessary for the interaction with ARF1. Together, these findings provide structural and biochemical insight into the multivalent membrane anchoring by the PH domain that may augment affinity and selectivity of FAPP1 toward the TGN membranes enriched in both PtdIns(4)P and GTP-bound ARF1.

  15. Lenz-Majewski mutations in PTDSS1 affect phosphatidylinositol 4-phosphate metabolism at ER-PM and ER-Golgi junctions.

    PubMed

    Sohn, Mira; Ivanova, Pavlina; Brown, H Alex; Toth, Daniel J; Varnai, Peter; Kim, Yeun Ju; Balla, Tamas

    2016-04-19

    Lenz-Majewski syndrome (LMS) is a rare disease characterized by complex craniofacial, dental, cutaneous, and limb abnormalities combined with intellectual disability. Mutations in thePTDSS1gene coding one of the phosphatidylserine (PS) synthase enzymes, PSS1, were described as causative in LMS patients. Such mutations render PSS1 insensitive to feedback inhibition by PS levels. Here we show that expression of mutant PSS1 enzymes decreased phosphatidylinositol 4-phosphate (PI4P) levels both in the Golgi and the plasma membrane (PM) by activating the Sac1 phosphatase and altered PI4P cycling at the PM. Conversely, inhibitors of PI4KA, the enzyme that makes PI4P in the PM, blocked PS synthesis and reduced PS levels by 50% in normal cells. However, mutant PSS1 enzymes alleviated the PI4P dependence of PS synthesis. Oxysterol-binding protein-related protein 8, which was recently identified as a PI4P-PS exchanger between the ER and PM, showed PI4P-dependent membrane association that was significantly decreased by expression of PSS1 mutant enzymes. Our studies reveal that PS synthesis is tightly coupled to PI4P-dependent PS transport from the ER. Consequently, PSS1 mutations not only affect cellular PS levels and distribution but also lead to a more complex imbalance in lipid homeostasis by disturbing PI4P metabolism. PMID:27044099

  16. Lenz-Majewski mutations in PTDSS1 affect phosphatidylinositol 4-phosphate metabolism at ER-PM and ER-Golgi junctions

    PubMed Central

    Sohn, Mira; Ivanova, Pavlina; Brown, H. Alex; Varnai, Peter; Kim, Yeun Ju; Balla, Tamas

    2016-01-01

    Lenz-Majewski syndrome (LMS) is a rare disease characterized by complex craniofacial, dental, cutaneous, and limb abnormalities combined with intellectual disability. Mutations in the PTDSS1 gene coding one of the phosphatidylserine (PS) synthase enzymes, PSS1, were described as causative in LMS patients. Such mutations render PSS1 insensitive to feedback inhibition by PS levels. Here we show that expression of mutant PSS1 enzymes decreased phosphatidylinositol 4-phosphate (PI4P) levels both in the Golgi and the plasma membrane (PM) by activating the Sac1 phosphatase and altered PI4P cycling at the PM. Conversely, inhibitors of PI4KA, the enzyme that makes PI4P in the PM, blocked PS synthesis and reduced PS levels by 50% in normal cells. However, mutant PSS1 enzymes alleviated the PI4P dependence of PS synthesis. Oxysterol-binding protein–related protein 8, which was recently identified as a PI4P-PS exchanger between the ER and PM, showed PI4P-dependent membrane association that was significantly decreased by expression of PSS1 mutant enzymes. Our studies reveal that PS synthesis is tightly coupled to PI4P-dependent PS transport from the ER. Consequently, PSS1 mutations not only affect cellular PS levels and distribution but also lead to a more complex imbalance in lipid homeostasis by disturbing PI4P metabolism. PMID:27044099

  17. Lenz-Majewski mutations in PTDSS1 affect phosphatidylinositol 4-phosphate metabolism at ER-PM and ER-Golgi junctions.

    PubMed

    Sohn, Mira; Ivanova, Pavlina; Brown, H Alex; Toth, Daniel J; Varnai, Peter; Kim, Yeun Ju; Balla, Tamas

    2016-04-19

    Lenz-Majewski syndrome (LMS) is a rare disease characterized by complex craniofacial, dental, cutaneous, and limb abnormalities combined with intellectual disability. Mutations in thePTDSS1gene coding one of the phosphatidylserine (PS) synthase enzymes, PSS1, were described as causative in LMS patients. Such mutations render PSS1 insensitive to feedback inhibition by PS levels. Here we show that expression of mutant PSS1 enzymes decreased phosphatidylinositol 4-phosphate (PI4P) levels both in the Golgi and the plasma membrane (PM) by activating the Sac1 phosphatase and altered PI4P cycling at the PM. Conversely, inhibitors of PI4KA, the enzyme that makes PI4P in the PM, blocked PS synthesis and reduced PS levels by 50% in normal cells. However, mutant PSS1 enzymes alleviated the PI4P dependence of PS synthesis. Oxysterol-binding protein-related protein 8, which was recently identified as a PI4P-PS exchanger between the ER and PM, showed PI4P-dependent membrane association that was significantly decreased by expression of PSS1 mutant enzymes. Our studies reveal that PS synthesis is tightly coupled to PI4P-dependent PS transport from the ER. Consequently, PSS1 mutations not only affect cellular PS levels and distribution but also lead to a more complex imbalance in lipid homeostasis by disturbing PI4P metabolism.

  18. A High-Yield Co-Expression System for the Purification of an Intact Drs2p-Cdc50p Lipid Flippase Complex, Critically Dependent on and Stabilized by Phosphatidylinositol-4-Phosphate

    PubMed Central

    Azouaoui, Hassina; Montigny, Cédric; Ash, Miriam-Rose; Fijalkowski, Frank; Jacquot, Aurore; Grønberg, Christina; López-Marqués, Rosa L.; Palmgren, Michael G.; Garrigos, Manuel; le Maire, Marc; Decottignies, Paulette; Gourdon, Pontus; Nissen, Poul; Champeil, Philippe; Lenoir, Guillaume

    2014-01-01

    P-type ATPases from the P4 subfamily (P4-ATPases) are energy-dependent transporters, which are thought to establish lipid asymmetry in eukaryotic cell membranes. Together with their Cdc50 accessory subunits, P4-ATPases couple ATP hydrolysis to lipid transport from the exoplasmic to the cytoplasmic leaflet of plasma membranes, late Golgi membranes, and endosomes. To gain insights into the structure and function of these important membrane pumps, robust protocols for expression and purification are required. In this report, we present a procedure for high-yield co-expression of a yeast flippase, the Drs2p-Cdc50p complex. After recovery of yeast membranes expressing both proteins, efficient purification was achieved in a single step by affinity chromatography on streptavidin beads, yielding ∼1–2 mg purified Drs2p-Cdc50p complex per liter of culture. Importantly, the procedure enabled us to recover a fraction that mainly contained a 1∶1 complex, which was assessed by size-exclusion chromatography and mass spectrometry. The functional properties of the purified complex were examined, including the dependence of its catalytic cycle on specific lipids. The dephosphorylation rate was stimulated in the simultaneous presence of the transported substrate, phosphatidylserine (PS), and the regulatory lipid phosphatidylinositol-4-phosphate (PI4P), a phosphoinositide that plays critical roles in membrane trafficking events from the trans-Golgi network (TGN). Likewise, overall ATP hydrolysis by the complex was critically dependent on the simultaneous presence of PI4P and PS. We also identified a prominent role for PI4P in stabilization of the Drs2p-Cdc50p complex towards temperature- or C12E8-induced irreversible inactivation. These results indicate that the Drs2p-Cdc50p complex remains functional after affinity purification and that PI4P as a cofactor tightly controls its stability and catalytic activity. This work offers appealing perspectives for detailed structural and

  19. Bipolar Plasma Membrane Distribution of Phosphoinositides and Their Requirement for Auxin-Mediated Cell Polarity and Patterning in Arabidopsis[W

    PubMed Central

    Tejos, Ricardo; Sauer, Michael; Vanneste, Steffen; Palacios-Gomez, Miriam; Li, Hongjiang; Heilmann, Mareike; van Wijk, Ringo; Vermeer, Joop E.M.; Heilmann, Ingo; Munnik, Teun; Friml, Jiří

    2014-01-01

    Cell polarity manifested by asymmetric distribution of cargoes, such as receptors and transporters, within the plasma membrane (PM) is crucial for essential functions in multicellular organisms. In plants, cell polarity (re)establishment is intimately linked to patterning processes. Despite the importance of cell polarity, its underlying mechanisms are still largely unknown, including the definition and distinctiveness of the polar domains within the PM. Here, we show in Arabidopsis thaliana that the signaling membrane components, the phosphoinositides phosphatidylinositol 4-phosphate (PtdIns4P) and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] as well as PtdIns4P 5-kinases mediating their interconversion, are specifically enriched at apical and basal polar plasma membrane domains. The PtdIns4P 5-kinases PIP5K1 and PIP5K2 are redundantly required for polar localization of specifically apical and basal cargoes, such as PIN-FORMED transporters for the plant hormone auxin. As a consequence of the polarity defects, instructive auxin gradients as well as embryonic and postembryonic patterning are severely compromised. Furthermore, auxin itself regulates PIP5K transcription and PtdIns4P and PtdIns(4,5)P2 levels, in particular their association with polar PM domains. Our results provide insight into the polar domain–delineating mechanisms in plant cells that depend on apical and basal distribution of membrane lipids and are essential for embryonic and postembryonic patterning. PMID:24876254

  20. Phosphatidylinositol 3-Phosphate 5-Kinase, FAB1/PIKfyve Kinase Mediates Endosome Maturation to Establish Endosome-Cortical Microtubule Interaction in Arabidopsis1[OPEN

    PubMed Central

    Hirano, Tomoko; Munnik, Teun; Sato, Masa H.

    2015-01-01

    Phosphatidylinositol 3,5-bisphosphate [PtdIns(3,5)P2] is an important lipid in membrane trafficking in animal and yeast systems; however, its role is still largely obscure in plants. Here, we demonstrate that the phosphatidylinositol 3-phosphate 5-kinase, formation of aploid and binucleate cells1 (FAB1)/FYVE finger-containing phosphoinositide kinase (PIKfyve), and its product, PtdIns(3,5)P2, are essential for the maturation process of endosomes to mediate cortical microtubule association of endosomes, thereby controlling proper PIN-FORMED protein trafficking in young cortical and stele cells of root. We found that FAB1 predominantly localizes on the Sorting Nexin1 (SNX1)-residing late endosomes, and a loss of FAB1 function causes the release of late endosomal proteins, Ara7, and SNX1 from the endosome membrane, indicating that FAB1, or its product PtdIns(3,5)P2, mediates the maturation process of the late endosomes. We also found that loss of FAB1 function causes the release of endosomes from cortical microtubules and disturbs proper cortical microtubule organization. PMID:26353760

  1. Phosphatidylinositol 4,5-Bisphosphate Influences PIN Polarization by Controlling Clathrin-Mediated Membrane Trafficking in Arabidopsis[C][W

    PubMed Central

    Ischebeck, Till; Werner, Stephanie; Krishnamoorthy, Praveen; Lerche, Jennifer; Meijón, Mónica; Stenzel, Irene; Löfke, Christian; Wiessner, Theresa; Im, Yang Ju; Perera, Imara Y.; Iven, Tim; Feussner, Ivo; Busch, Wolfgang; Boss, Wendy F.; Teichmann, Thomas; Hause, Bettina; Persson, Staffan; Heilmann, Ingo

    2013-01-01

    The functions of the minor phospholipid phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2] during vegetative plant growth remain obscure. Here, we targeted two related phosphatidylinositol 4-phosphate 5-kinases (PI4P 5-kinases) PIP5K1 and PIP5K2, which are expressed ubiquitously in Arabidopsis thaliana. A pip5k1 pip5k2 double mutant with reduced PtdIns(4,5)P2 levels showed dwarf stature and phenotypes suggesting defects in auxin distribution. The roots of the pip5k1 pip5k2 double mutant had normal auxin levels but reduced auxin transport and altered distribution. Fluorescence-tagged auxin efflux carriers PIN-FORMED (PIN1)–green fluorescent protein (GFP) and PIN2-GFP displayed abnormal, partially apolar distribution. Furthermore, fewer brefeldin A–induced endosomal bodies decorated by PIN1-GFP or PIN2-GFP formed in pip5k1 pip5k2 mutants. Inducible overexpressor lines for PIP5K1 or PIP5K2 also exhibited phenotypes indicating misregulation of auxin-dependent processes, and immunolocalization showed reduced membrane association of PIN1 and PIN2. PIN cycling and polarization require clathrin-mediated endocytosis and labeled clathrin light chain also displayed altered localization patterns in the pip5k1 pip5k2 double mutant, consistent with a role for PtdIns(4,5)P2 in the regulation of clathrin-mediated endocytosis. Further biochemical tests on subcellular fractions enriched for clathrin-coated vesicles (CCVs) indicated that pip5k1 and pip5k2 mutants have reduced CCV-associated PI4P 5-kinase activity. Together, the data indicate an important role for PtdIns(4,5)P2 in the control of clathrin dynamics and in auxin distribution in Arabidopsis. PMID:24326589

  2. INTRACELLULAR TRANSPORT. PI4P/phosphatidylserine countertransport at ORP5- and ORP8-mediated ER-plasma membrane contacts.

    PubMed

    Chung, Jeeyun; Torta, Federico; Masai, Kaori; Lucast, Louise; Czapla, Heather; Tanner, Lukas B; Narayanaswamy, Pradeep; Wenk, Markus R; Nakatsu, Fubito; De Camilli, Pietro

    2015-07-24

    Lipid transfer between cell membrane bilayers at contacts between the endoplasmic reticulum (ER) and other membranes help to maintain membrane lipid homeostasis. We found that two similar ER integral membrane proteins, oxysterol-binding protein (OSBP)-related protein 5 (ORP5) and ORP8, tethered the ER to the plasma membrane (PM) via the interaction of their pleckstrin homology domains with phosphatidylinositol 4-phosphate (PI4P) in this membrane. Their OSBP-related domains (ORDs) harbored either PI4P or phosphatidylserine (PS) and exchanged these lipids between bilayers. Gain- and loss-of-function experiments showed that ORP5 and ORP8 could mediate PI4P/PS countertransport between the ER and the PM, thus delivering PI4P to the ER-localized PI4P phosphatase Sac1 for degradation and PS from the ER to the PM. This exchange helps to control plasma membrane PI4P levels and selectively enrich PS in the PM.

  3. Arabidopsis D6PK is a lipid domain-dependent mediator of root epidermal planar polarity.

    PubMed

    Stanislas, Thomas; Hüser, Anke; Barbosa, Inês C R; Kiefer, Christian S; Brackmann, Klaus; Pietra, Stefano; Gustavsson, Anna; Zourelidou, Melina; Schwechheimer, Claus; Grebe, Markus

    2015-01-01

    Development of diverse multicellular organisms relies on coordination of single-cell polarities within the plane of the tissue layer (planar polarity). Cell polarity often involves plasma membrane heterogeneity generated by accumulation of specific lipids and proteins into membrane subdomains. Coordinated hair positioning along Arabidopsis root epidermal cells provides a planar polarity model in plants, but knowledge about the functions of proteo-lipid domains in planar polarity signalling remains limited. Here we show that Rho-of-plant (ROP) 2 and 6, phosphatidylinositol-4-phosphate 5-kinase 3 (PIP5K3), DYNAMIN-RELATED PROTEIN (DRP) 1A and DRP2B accumulate in a sterol-enriched, polar membrane domain during root hair initiation. DRP1A, DRP2B, PIP5K3 and sterols are required for planar polarity and the AGCVIII kinase D6 PROTEIN KINASE (D6PK) is a modulator of this process. D6PK undergoes phosphatidylinositol-4,5-bisphosphate- and sterol-dependent basal-to-planar polarity switching into the polar, lipid-enriched domain just before hair formation, unravelling lipid-dependent D6PK localization during late planar polarity signalling.

  4. PI4P/phosphatidylserine countertransport at ORP5- and ORP8-mediated ER–plasma membrane contacts

    PubMed Central

    Chung, Jeeyun; Torta, Federico; Masai, Kaori; Lucast, Louise; Czapla, Heather; Tanner, Lukas B.; Narayanaswamy, Pradeep; Wenk, Markus R.

    2015-01-01

    Lipid transfer between cell membrane bilayers at contacts between the endoplasmic reticulum (ER) and other membranes help to maintain membrane lipid homeostasis. We found that two similar ER integral membrane proteins, oxysterol-binding protein (OSBP)–related protein 5 (ORP5) and ORP8, tethered the ER to the plasma membrane (PM) via the interaction of their pleckstrin homology domains with phosphatidylinositol 4-phosphate (PI4P) in this membrane. Their OSBP-related domains (ORDs) harbored either PI4P or phosphatidylserine (PS) and exchanged these lipids between bilayers. Gain- and loss-of-function experiments showed that ORP5 and ORP8 could mediate PI4P/PS counter transport between the ER and the PM, thus delivering PI4P to the ER-localized PI4P phosphatase Sac1 for degradation and PS from the ER to the PM. This exchange helps to control plasma membrane PI4P levels and selectively enrich PS in the PM. PMID:26206935

  5. Effect of phosphorylation of phosphatidylinositol on myelin basic protein-mediated binding of actin filaments to lipid bilayers in vitro.

    PubMed

    Boggs, Joan M; Rangaraj, Godha; Dicko, Awa

    2012-09-01

    Myelin basic protein (MBP) binds to negatively charged lipids on the cytosolic surface of oligodendrocytes and is believed to be responsible for adhesion of these surfaces in the multilayered myelin sheath. It can also assemble actin filaments and tether them to lipid bilayers through electrostatic interactions. Here we investigate the effect of increased negative charge of the lipid bilayer due to phosphorylation of phosphatidylinositol (PI) on MBP-mediated binding of actin to the lipid bilayer, by substituting phosphatidylinositol 4-phosphate or phosphatidylinositol 4,5-bisphosphate for PI in phosphatidylcholine/phosphatidylglycerol lipid vesicles. Phosphorylation of PI caused dissociation of the MBP/actin complex from the lipid vesicles due to repulsion of the negatively charged complex from the negatively charged membrane surface. An effect of phosphorylation could be detected even if the inositol lipid was only 2mol% of the total lipid. Calcium-calmodulin dissociated actin from the MBP-lipid vesicles and phosphorylation of PI increased the amount dissociated. These results show that changes to the lipid composition of myelin, which could occur during signaling or other physiological events, could regulate the ability of MBP to act as a scaffolding protein and bind actin filaments to the lipid bilayer.

  6. Recruitment of PLANT U-BOX13 and the PI4Kβ1/β2 Phosphatidylinositol-4 Kinases by the Small GTPase RabA4B Plays Important Roles during Salicylic Acid-Mediated Plant Defense Signaling in Arabidopsis[OPEN

    PubMed Central

    Antignani, Vincenzo; Klocko, Amy L.; Bak, Gwangbae; Chandrasekaran, Suma D.; Dunivin, Taylor; Nielsen, Erik

    2015-01-01

    Protection against microbial pathogens involves the activation of cellular immune responses in eukaryotes, and this cellular immunity likely involves changes in subcellular membrane trafficking. In eukaryotes, members of the Rab GTPase family of small monomeric regulatory GTPases play prominent roles in the regulation of membrane trafficking. We previously showed that RabA4B is recruited to vesicles that emerge from trans-Golgi network (TGN) compartments and regulates polarized membrane trafficking in plant cells. As part of this regulation, RabA4B recruits the closely related phosphatidylinositol 4-kinase (PI4K) PI4Kβ1 and PI4Kβ2 lipid kinases. Here, we identify a second Arabidopsis thaliana RabA4B-interacting protein, PLANT U-BOX13 (PUB13), which has recently been identified to play important roles in salicylic acid (SA)-mediated defense signaling. We show that PUB13 interacts with RabA4B through N-terminal domains and with phosphatidylinositol 4-phosphate (PI-4P) through a C-terminal armadillo domain. Furthermore, we demonstrate that a functional fluorescent PUB13 fusion protein (YFP-PUB13) localizes to TGN and Golgi compartments and that PUB13, PI4Kβ1, and PI4Kβ2 are negative regulators of SA-mediated induction of pathogenesis-related gene expression. Taken together, these results highlight a role for RabA4B and PI-4P in SA-dependent defense responses. PMID:25634989

  7. Contribution of PIP-5 kinase I{alpha} to raft-based Fc{gamma}RIIA signaling

    SciTech Connect

    Szymanska, Ewelina; Korzeniowski, Marek; Raynal, Patrick; Sobota, Andrzej; Kwiatkowska, Katarzyna

    2009-04-01

    Receptor Fc{gamma}IIA (Fc{gamma}RIIA) associates with plasma membrane rafts upon activation to trigger signaling cascades leading to actin polymerization. We examined whether compartmentalization of PI(4,5)P{sub 2} and PI(4,5)P{sub 2}-synthesizing PIP5-kinase I{alpha} to rafts contributes to Fc{gamma}RIIA signaling. A fraction of PIP5-kinase I{alpha} was detected in raft-originating detergent-resistant membranes (DRM) isolated from U937 monocytes and other cells. The DRM of U937 monocytes contained also a major fraction of PI(4,5)P{sub 2}. PIP5-kinase I{alpha} bound PI(4,5)P{sub 2}, and depletion of the lipid displaced PIP5-kinase I{alpha} from the DRM. Activation of Fc{gamma}RIIA in BHK transfectants led to recruitment of the kinase to the plasma membrane and enrichment of DRM in PI(4,5)P{sub 2}. Immunofluorescence studies revealed that in resting cells the kinase was associated with the plasma membrane, cytoplasmic vesicles and the nucleus. After Fc{gamma}RIIA activation, PIP5-kinase I{alpha} and PI(4,5)P{sub 2} co-localized transiently with the activated receptor at distinct cellular locations. Immunoelectron microscopy studies revealed that PIP5-kinase I{alpha} and PI(4,5)P{sub 2} were present at the edges of electron-dense assemblies containing activated Fc{gamma}RIIA in their core. The data suggest that activation of Fc{gamma}RIIA leads to membrane rafts coalescing into signaling platforms containing PIP5-kinase I{alpha} and PI(4,5)P{sub 2}.

  8. Uncoupling of 3'-phosphatase and 5'-kinase functions in budding yeast. Characterization of Saccharomyces cerevisiae DNA 3'-phosphatase (TPP1).

    PubMed

    Vance, J R; Wilson, T E

    2001-05-01

    Polynucleotide kinase is a bifunctional enzyme containing both DNA 3'-phosphatase and 5'-kinase activities seemingly suited to the coupled repair of single-strand nicks in which the phosphate has remained with the 3'-base. We show that the yeast Saccharomyces cerevisiae is able to repair transformed dephosphorylated linear plasmids by non-homologous end joining with considerable efficiency independently of the end-processing polymerase Pol4p. Homology searches and biochemical assays did not reveal a 5'-kinase that would account for this repair, however. Instead, open reading frame YMR156C (here named TPP1) is shown to encode only a polynucleotide kinase-type 3'-phosphatase. Tpp1p bears extensive similarity to the ancient L-2-halo-acid dehalogenase and DDDD phosphohydrolase superfamilies, but is specific for double-stranded DNA. It is present at high levels in cell extracts in a functional form and so does not represent a pseudogene. Moreover, the phosphatase-only nature of this gene is shared by Saccharomyces mikatae YMR156C and Arabidopsis thaliana K15M2.3. Repair of 3'-phosphate and 5'-hydroxyl lesions is thus uncoupled in budding yeast as compared with metazoans. Repair of transformed dephosphorylated plasmids, and 5'-hydroxyl blocking lesions more generally, likely proceeds by a cycle of base removal and resynthesis.

  9. Triggering Actin Comets Versus Membrane Ruffles: Distinctive Effects of Phosphoinositides on Actin Reorganization

    PubMed Central

    Ueno, Tasuku; Falkenburger, Björn H.; Pohlmeyer, Christopher; Inoue, Takanari

    2012-01-01

    A limited set of phosphoinositide membrane lipids regulate diverse cellular functions including proliferation, differentiation, and migration. We developed two techniques based on rapamycin-induced protein dimerization to rapidly change the concentration of plasma membrane phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. First, we increased PI(4,5)P2 synthesis from phosphatidylinositol 4-phosphate [PI(4)P] using a membrane recruitable form of PI(4)P 5-kinase, and found that COS-7, HeLa, and HEK293 cells formed bundles of motile actin filaments known as actin comets. In contrast, a second technique that increased the concentration of PI(4,5)P2 without consuming PI(4)P induced membrane ruffles. These distinct phenotypes were mediated by dynamin-mediated vesicular trafficking and mutually inhibitory crosstalk between the small guanosine triphosphatases Rac and RhoA. Our results indicate that the effect of PI(4,5)P2 on actin reorganization depends on the abundance of other phosphoinositides, such as PI(4)P. Thus, combinatorial regulation of phosphoinositide concentrations may contribute to the diversity of phosphoinositide functions. PMID:22169478

  10. Phosphorylation regulates the Star-PAP-PIPKIα interaction and directs specificity toward mRNA targets.

    PubMed

    Mohan, Nimmy; Sudheesh, A P; Francis, Nimmy; Anderson, Richard; Laishram, Rakesh S

    2015-08-18

    Star-PAP is a nuclear non-canonical poly(A) polymerase (PAP) that shows specificity toward mRNA targets. Star-PAP activity is stimulated by lipid messenger phosphatidyl inositol 4,5 bisphoshate (PI4,5P2) and is regulated by the associated Type I phosphatidylinositol-4-phosphate 5-kinase that synthesizes PI4,5P2 as well as protein kinases. These associated kinases act as coactivators of Star-PAP that regulates its activity and specificity toward mRNAs, yet the mechanism of control of these interactions are not defined. We identified a phosphorylated residue (serine 6, S6) on Star-PAP in the zinc finger region, the domain required for PIPKIα interaction. We show that S6 is phosphorylated by CKIα within the nucleus which is required for Star-PAP nuclear retention and interaction with PIPKIα. Unlike the CKIα mediated phosphorylation at the catalytic domain, Star-PAP S6 phosphorylation is insensitive to oxidative stress suggesting a signal mediated regulation of CKIα activity. S6 phosphorylation together with coactivator PIPKIα controlled select subset of Star-PAP target messages by regulating Star-PAP-mRNA association. Our results establish a novel role for phosphorylation in determining Star-PAP target mRNA specificity and regulation of 3'-end processing.

  11. Phosphorylation regulates the Star-PAP-PIPKIα interaction and directs specificity toward mRNA targets

    PubMed Central

    Mohan, Nimmy; AP, Sudheesh; Francis, Nimmy; Anderson, Richard; Laishram, Rakesh S.

    2015-01-01

    Star-PAP is a nuclear non-canonical poly(A) polymerase (PAP) that shows specificity toward mRNA targets. Star-PAP activity is stimulated by lipid messenger phosphatidyl inositol 4,5 bisphoshate (PI4,5P2) and is regulated by the associated Type I phosphatidylinositol-4-phosphate 5-kinase that synthesizes PI4,5P2 as well as protein kinases. These associated kinases act as coactivators of Star-PAP that regulates its activity and specificity toward mRNAs, yet the mechanism of control of these interactions are not defined. We identified a phosphorylated residue (serine 6, S6) on Star-PAP in the zinc finger region, the domain required for PIPKIα interaction. We show that S6 is phosphorylated by CKIα within the nucleus which is required for Star-PAP nuclear retention and interaction with PIPKIα. Unlike the CKIα mediated phosphorylation at the catalytic domain, Star-PAP S6 phosphorylation is insensitive to oxidative stress suggesting a signal mediated regulation of CKIα activity. S6 phosphorylation together with coactivator PIPKIα controlled select subset of Star-PAP target messages by regulating Star-PAP-mRNA association. Our results establish a novel role for phosphorylation in determining Star-PAP target mRNA specificity and regulation of 3′-end processing. PMID:26138484

  12. Genetic evidence of a role for membrane lipid composition in the regulation of soluble NEM-sensitive factor receptor function in Saccharomyces cerevisiae.

    PubMed Central

    Coluccio, Alison; Malzone, Maria; Neiman, Aaron M

    2004-01-01

    SEC9 and SPO20 encode SNARE proteins related to the mammalian SNAP-25 family. Sec9p associates with the SNAREs Sso1/2p and Snc1/2p to promote the fusion of vesicles with the plasma membrane. Spo20p functions with the same two partner SNAREs to mediate the fusion of vesicles with the prospore membrane during sporogenesis. A chimeric molecule, in which the helices of Sec9p that bind to Sso1/2p and Snc1/2p are replaced with the homologous regions of Spo20p, will not support vesicle fusion in vegetative cells. The phosphatidylinositol-4-phosphate-5-kinase MSS4 was isolated as a high-copy suppressor that permits this chimera to rescue the temperature-sensitive growth of a sec9-4 mutant. Suppression by MSS4 is specific to molecules that contain the Spo20p helical domains. This suppression requires an intact copy of SPO14, encoding phospholipase D. Overexpression of MSS4 leads to a recruitment of the Spo14 protein to the plasma membrane and this may be the basis for MSS4 action. Consistent with this, deletion of KES1, a gene that behaves as a negative regulator of SPO14, also promotes the function of SPO20 in vegetative cells. These results indicate that elevated levels of phosphatidic acid in the membrane may be required specifically for the function of SNARE complexes containing Spo20p. PMID:15020409

  13. RdgBα reciprocally transfers PA and PI at ER-PM contact sites to maintain PI(4,5)P2 homoeostasis during phospholipase C signalling in Drosophila photoreceptors.

    PubMed

    Cockcroft, Shamshad; Garner, Kathryn; Yadav, Shweta; Gomez-Espinoza, Evelyn; Raghu, Padinjat

    2016-02-01

    Phosphatidylinositol (PI) is the precursor lipid for the synthesis of PI 4,5-bisphosphate [PI(4,5)P2] at the plasma membrane (PM) and is sequentially phosphorylated by the lipid kinases, PI 4-kinase and phosphatidylinositol 4-phosphate (PI4P)-5-kinase. Receptor-mediated hydrolysis of PI(4,5)P2 takes place at the PM but PI resynthesis occurs at the endoplasmic reticulum (ER). Thus PI(4,5)P2 resynthesis requires the reciprocal transport of two key intermediates, phosphatidic acid (PA) and PI between the ER and the PM. PI transfer proteins (PITPs), defined by the presence of the PITP domain, can facilitate lipid transfer between membranes; the PITP domain comprises a hydrophobic cavity with dual specificity but accommodates a single phospholipid molecule. The class II PITP, retinal degeneration type B (RdgB)α is a multi-domain protein and its PITP domain can bind and transfer PI and PA. In Drosophila photoreceptors, a well-defined G-protein-coupled phospholipase Cβ (PLCβ) signalling pathway, phototransduction defects resulting from loss of RdgBα can be rescued by expression of the PITP domain provided it is competent for both PI and PA transfer. We propose that RdgBα proteins maintain PI(4,5)P2 homoeostasis after PLC activation by facilitating the reciprocal transport of PA and PI at ER-PM membrane contact sites.

  14. A novel IRS-1-associated protein, DGKζ regulates GLUT4 translocation in 3T3-L1 adipocytes

    PubMed Central

    Liu, TingYu; Yu, BuChin; Kakino, Mamoru; Fujimoto, Hitoshi; Ando, Yasutoshi; Hakuno, Fumihiko; Takahashi, Shin-Ichiro

    2016-01-01

    Insulin receptor substrates (IRSs) are major targets of insulin receptor tyrosine kinases. Here we identified diacylglycerol kinase zeta (DGKζ) as an IRS-1-associated protein, and examined roles of DGKζ in glucose transporter 4 (GLUT4) translocation to the plasma membrane. When DGKζ was knocked-down in 3T3-L1 adipocytes, insulin-induced GLUT4 translocation was inhibited without affecting other mediators of insulin-dependent signaling. Similarly, knockdown of phosphatidylinositol 4-phosphate 5-kinase 1α (PIP5K1α), which had been reported to interact with DGKζ, also inhibited insulin-induced GLUT4 translocation. Moreover, DGKζ interacted with IRS-1 without insulin stimulation, but insulin stimulation decreased this interaction. Over-expression of sDGKζ (short-form DGKζ), which competed out DGKζ from IRS-1, enhanced GLUT4 translocation without insulin stimulation. Taking these results together with the data showing that cellular PIP5K activity was correlated with GLUT4 translocation ability, we concluded that IRS-1-associated DGKζ prevents GLUT4 translocation in the absence of insulin and that the DGKζ dissociated from IRS-1 by insulin stimulation enhances GLUT4 translocation through PIP5K1α activity. PMID:27739494

  15. Activated type I TGFbeta receptor (Alk5) kinase confers enhancedsurvival to mammary epithelial cells and accelerates mammary tumorprogression

    SciTech Connect

    Muraoka-Cook, Rebecca S.; Shin, Incheol; Yi, Jae Youn; Easterly,Evangeline; Barcellos-Hoff, Mary Helen; Yingling, Jonathan M.; Zent, Roy; Arteaga, Carlos L.

    2005-01-02

    The transforming growth factor-betas (TGF{beta}s) are members of a large superfamily of pleiotropic cytokines that also includes the activins and the bone morphogenetic proteins (BMPs). Members of the TGF{beta} family regulate complex physiological processes such cell proliferation, differentiation, adhesion, cell-cell and cell-matrix interactions, motility, and cell death, among others (Massague, 1998). Dysregulation of TGF{beta} signaling contributes to several pathological processes including cancer, fibrosis, and auto-immune disorders (Massague et al., 2000). The TGF{beta}s elicit their biological effects by binding to type II and type I transmembrane receptor serine-threonine kinases (T{beta}RII and T{beta}RI) which, in turn, phosphorylated Smad 2 and Smad 3. Phosphorylated Smad 2/3 associate with Smad 4 and, as a heteromeric complex, translocate to the nucleus where they regulate gene transcription. The inhibitory Smad7 down regulates TGF{beta} signaling by binding to activated T{beta}RI and interfering with its ability to phosphorylate Smad 2/3 (Derynck and Zhang, 2003; Shi and Massague, 2003). Signaling is also regulated by Smad proteolysis. TGF{beta} receptor-mediated activation results in multi-ubiquitination of Smad 2 in the nucleus and subsequent degradation of Smad 2 by the proteasome (Lo and Massague, 1999). Activation of TGF{beta} receptors also induces mobilization of a Smad 7-Smurf complex from the nucleus to the cytoplasm; this complex recognizes the activated receptors and mediates their ubiquitination and internalization via caveolin-rich vesicles, leading to termination of TGF{beta} signaling (Di Guglielmo et al., 2003). Other signal transducers/pathways have been implicated in TGF{beta} actions. These include the extracellular signal-regulated kinase (Erk), c-Jun N-terminal kinase (Jnk), p38 mitogen-activated protein kinase (MAPK), protein phosphatase PP2A, phosphatidylinositol-3 kinase (PI3K), and the family of Rho GTPases [reviewed in

  16. Identification of a major IP5 kinase in Cryptococcus neoformans confirms that PP-IP5/IP7, not IP6, is essential for virulence.

    PubMed

    Li, Cecilia; Lev, Sophie; Saiardi, Adolfo; Desmarini, Desmarini; Sorrell, Tania C; Djordjevic, Julianne T

    2016-01-01

    Fungal inositol polyphosphate (IP) kinases catalyse phosphorylation of IP3 to inositol pyrophosphate, PP-IP5/IP7, which is essential for virulence of Cryptococcus neoformans. Cryptococcal Kcs1 converts IP6 to PP-IP5/IP7, but the kinase converting IP5 to IP6 is unknown. Deletion of a putative IP5 kinase-encoding gene (IPK1) alone (ipk1Δ), and in combination with KCS1 (ipk1Δkcs1Δ), profoundly reduced virulence in mice. However, deletion of KCS1 and IPK1 had a greater impact on virulence attenuation than that of IPK1 alone. ipk1Δkcs1Δ and kcs1Δ lung burdens were also lower than those of ipk1Δ. Unlike ipk1Δ, ipk1Δkcs1Δ and kcs1Δ failed to disseminate to the brain. IP profiling confirmed Ipk1 as the major IP5 kinase in C. neoformans: ipk1Δ produced no IP6 or PP-IP5/IP7 and, in contrast to ipk1Δkcs1Δ, accumulated IP5 and its pyrophosphorylated PP-IP4 derivative. Kcs1 is therefore a dual specificity (IP5 and IP6) kinase producing PP-IP4 and PP-IP5/IP7. All mutants were similarly attenuated in virulence phenotypes including laccase, urease and growth under oxidative/nitrosative stress. Alternative carbon source utilisation was also reduced significantly in all mutants except ipk1Δ, suggesting that PP-IP4 partially compensates for absent PP-IP5/IP7 in ipk1Δ grown under this condition. In conclusion, PP-IP5/IP7, not IP6, is essential for fungal virulence. PMID:27033523

  17. Glutamate-5-kinase from Escherichia coli: gene cloning, overexpression, purification and crystallization of the recombinant enzyme and preliminary X-ray studies.

    PubMed

    Pérez-Arellano, Isabel; Gil-Ortiz, Fernando; Cervera, Javier; Rubio, Vicente

    2004-11-01

    Glutamate-5-kinase (G5K) catalyzes the first step of proline (and, in mammals, ornithine) biosynthesis. It is a key regulatory point of these routes, since it is the subject of feedback allosteric inhibition by proline or ornithine. The Escherichia coli gene (proB) for G5K was cloned in pET22, overexpressed in E. coli, purified in a few steps in high yield to 95% homogeneity in the highly active proline-inhibitable form and was shown by cross-linking to be a tetramer. It was crystallized by the hanging-drop vapour-diffusion method at 294 K in the presence of ADP, MgCl(2) and L-glutamate using 1.6 M MgSO(4), 0.1 M KCl in 0.1 M MES pH 6.5 as the crystallization solution. The tetragonal bipyramid-shaped crystals diffracted to 2.5 A resolution using synchrotron radiation. The crystals belong to space group P4(1(3))2(1)2, with unit-cell parameters a = b = 101.1, c = 178.6 A, and contain two monomers in the asymmetric unit, with 58% solvent content.

  18. The role of PI3K/AKT-related PIP5K1α and the discovery of its selective inhibitor for treatment of advanced prostate cancer

    PubMed Central

    Semenas, Julius; Hedblom, Andreas; Miftakhova, Regina R.; Sarwar, Martuza; Larsson, Rikard; Shcherbina, Liliya; Johansson, Martin E.; Härkönen, Pirkko; Sterner, Olov; Persson, Jenny L.

    2014-01-01

    Nitrogen-containing heterocyclic compounds are an important class of molecules that are commonly used for the synthesis of candidate drugs. Phosphatidylinositol-4-phosphate 5-kinase-α (PIP5Kα) is a lipid kinase, similar to PI3K. However, the role of PIP5K1α in oncogenic processes and the development of inhibitors that selectively target PIP5K1α have not been reported. In the present study we report that overexpression of PIP5K1α is associated with poor prognosis in prostate cancer and correlates with an elevated level of the androgen receptor. Overexpression of PIP5K1α in PNT1A nonmalignant cells results in an increased AKT activity and an increased survival, as well as invasive malignant phenotype, whereas siRNA-mediated knockdown of PIP5K1α in aggressive PC-3 cells leads to a reduced AKT activity and an inhibition in tumor growth in xenograft mice. We further report a previously unidentified role for PIP5K1α as a druggable target for our newly developed compound ISA-2011B using a high-throughput KINOMEscan platform. ISA-2011B was discovered during our synthetic studies of C-1 indol-3-yl substituted 1,2,3,4-tetrahydroisoquinolines via a Pictet-Spengler approach. ISA-2011B significantly inhibits growth of tumor cells in xenograft mice, and we show that this is mediated by targeting PIP5K1α-associated PI3K/AKT and the downstream survival, proliferation, and invasion pathways. Further, siRNA-mediated knockdown of PIP5K1α exerts similar effects on PC3 cells as ISA-2011B treatment, significantly inhibiting AKT activity, increasing apoptosis and reducing invasion. Thus, PIP5K1α has high potential as a drug target, and compound ISA-2011B is interesting for further development of targeted cancer therapy. PMID:25071204

  19. The role of PI3K/AKT-related PIP5K1α and the discovery of its selective inhibitor for treatment of advanced prostate cancer.

    PubMed

    Semenas, Julius; Hedblom, Andreas; Miftakhova, Regina R; Sarwar, Martuza; Larsson, Rikard; Shcherbina, Liliya; Johansson, Martin E; Härkönen, Pirkko; Sterner, Olov; Persson, Jenny L

    2014-09-01

    Nitrogen-containing heterocyclic compounds are an important class of molecules that are commonly used for the synthesis of candidate drugs. Phosphatidylinositol-4-phosphate 5-kinase-α (PIP5Kα) is a lipid kinase, similar to PI3K. However, the role of PIP5K1α in oncogenic processes and the development of inhibitors that selectively target PIP5K1α have not been reported. In the present study we report that overexpression of PIP5K1α is associated with poor prognosis in prostate cancer and correlates with an elevated level of the androgen receptor. Overexpression of PIP5K1α in PNT1A nonmalignant cells results in an increased AKT activity and an increased survival, as well as invasive malignant phenotype, whereas siRNA-mediated knockdown of PIP5K1α in aggressive PC-3 cells leads to a reduced AKT activity and an inhibition in tumor growth in xenograft mice. We further report a previously unidentified role for PIP5K1α as a druggable target for our newly developed compound ISA-2011B using a high-throughput KINOMEscan platform. ISA-2011B was discovered during our synthetic studies of C-1 indol-3-yl substituted 1,2,3,4-tetrahydroisoquinolines via a Pictet-Spengler approach. ISA-2011B significantly inhibits growth of tumor cells in xenograft mice, and we show that this is mediated by targeting PIP5K1α-associated PI3K/AKT and the downstream survival, proliferation, and invasion pathways. Further, siRNA-mediated knockdown of PIP5K1α exerts similar effects on PC3 cells as ISA-2011B treatment, significantly inhibiting AKT activity, increasing apoptosis and reducing invasion. Thus, PIP5K1α has high potential as a drug target, and compound ISA-2011B is interesting for further development of targeted cancer therapy.

  20. Steering neuronal growth cones by shifting the imbalance between exocytosis and endocytosis.

    PubMed

    Tojima, Takuro; Itofusa, Rurika; Kamiguchi, Hiroyuki

    2014-05-21

    Extracellular molecular cues guide migrating growth cones along specific routes during development of axon tracts. Such processes rely on asymmetric elevation of cytosolic Ca(2+) concentrations across the growth cone that mediates its attractive or repulsive turning toward or away from the side with Ca(2+) elevation, respectively. Downstream of these Ca(2+) signals, localized activation of membrane trafficking steers the growth cone bidirectionally, with endocytosis driving repulsion and exocytosis causing attraction. However, it remains unclear how Ca(2+) can differentially regulate these opposite membrane-trafficking events. Here, we show that growth cone turning depends on localized imbalance between exocytosis and endocytosis and identify Ca(2+)-dependent signaling pathways mediating such imbalance. In embryonic chicken dorsal root ganglion neurons, repulsive Ca(2+) signals promote clathrin-mediated endocytosis through a 90 kDa splice variant of phosphatidylinositol-4-phosphate 5-kinase type-1γ (PIPKIγ90). In contrast, attractive Ca(2+) signals facilitate exocytosis but suppress endocytosis via Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and cyclin-dependent kinase 5 (Cdk5) that can inactivate PIPKIγ90. Blocking CaMKII or Cdk5 leads to balanced activation of both exocytosis and endocytosis that causes straight growth cone migration even in the presence of guidance signals, whereas experimentally perturbing the balance restores the growth cone's turning response. Remarkably, the direction of this resumed turning depends on relative activities of exocytosis and endocytosis, but not on the type of guidance signals. Our results suggest that navigating growth cones can be redirected by shifting the imbalance between exocytosis and endocytosis, highlighting the importance of membrane-trafficking imbalance for axon guidance and, possibly, for polarized cell migration in general.

  1. The role of PI3K/AKT-related PIP5K1α and the discovery of its selective inhibitor for treatment of advanced prostate cancer.

    PubMed

    Semenas, Julius; Hedblom, Andreas; Miftakhova, Regina R; Sarwar, Martuza; Larsson, Rikard; Shcherbina, Liliya; Johansson, Martin E; Härkönen, Pirkko; Sterner, Olov; Persson, Jenny L

    2014-09-01

    Nitrogen-containing heterocyclic compounds are an important class of molecules that are commonly used for the synthesis of candidate drugs. Phosphatidylinositol-4-phosphate 5-kinase-α (PIP5Kα) is a lipid kinase, similar to PI3K. However, the role of PIP5K1α in oncogenic processes and the development of inhibitors that selectively target PIP5K1α have not been reported. In the present study we report that overexpression of PIP5K1α is associated with poor prognosis in prostate cancer and correlates with an elevated level of the androgen receptor. Overexpression of PIP5K1α in PNT1A nonmalignant cells results in an increased AKT activity and an increased survival, as well as invasive malignant phenotype, whereas siRNA-mediated knockdown of PIP5K1α in aggressive PC-3 cells leads to a reduced AKT activity and an inhibition in tumor growth in xenograft mice. We further report a previously unidentified role for PIP5K1α as a druggable target for our newly developed compound ISA-2011B using a high-throughput KINOMEscan platform. ISA-2011B was discovered during our synthetic studies of C-1 indol-3-yl substituted 1,2,3,4-tetrahydroisoquinolines via a Pictet-Spengler approach. ISA-2011B significantly inhibits growth of tumor cells in xenograft mice, and we show that this is mediated by targeting PIP5K1α-associated PI3K/AKT and the downstream survival, proliferation, and invasion pathways. Further, siRNA-mediated knockdown of PIP5K1α exerts similar effects on PC3 cells as ISA-2011B treatment, significantly inhibiting AKT activity, increasing apoptosis and reducing invasion. Thus, PIP5K1α has high potential as a drug target, and compound ISA-2011B is interesting for further development of targeted cancer therapy. PMID:25071204

  2. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast.

    PubMed Central

    Cullen, C F; May, K M; Hagan, I M; Glover, D M; Ohkura, H

    2000-01-01

    We describe a general genetic method to identify genes encoding proteins that functionally interact with and/or are good candidates for downstream targets of a particular gene product. The screen identifies mutants whose growth depends on high levels of expression of that gene. We apply this to the plo1(+) gene that encodes a fission yeast homologue of the polo-like kinases. plo1(+) regulates both spindle formation and septation. We have isolated 17 high plo1(+)-dependent (pld) mutants that show defects in mitosis or septation. Three mutants show a mitotic arrest phenotype. Among the 14 pld mutants with septation defects, 12 mapped to known loci: cdc7, cdc15, cdc11 spg1, and sid2. One of the pld mutants, cdc7-PD1, was selected for suppressor analysis. As multicopy suppressors, we isolated four known genes involved in septation in fission yeast: spg1(+), sce3(+), cdc8(+), and rho1(+), and two previously uncharacterized genes, mpd1(+) and mpd2(+). mpd1(+) exhibits high homology to phosphatidylinositol 4-phosphate 5-kinase, while mpd2(+) resembles Saccharomyces cerevisiae SMY2; both proteins are involved in the regulation of actin-mediated processes. As chromosomal suppressors of cdc7-PD1, we isolated mutations of cdc16 that resulted in multiseptation without nuclear division. cdc16(+), dma1(+), byr3(+), byr4(+) and a truncated form of the cdc7 gene were isolated by complementation of one of these cdc16 mutations. These results demonstrate that screening for high dose-dependent mutants and their suppressors is an effective approach to identify functionally interacting genes. PMID:10924454

  3. Phosphatidylinositol and phosphatidic acid transport between the ER and plasma membrane during PLC activation requires the Nir2 protein.

    PubMed

    Kim, Yeun Ju; Guzman-Hernandez, Maria Luisa; Wisniewski, Eva; Echeverria, Nicolas; Balla, Tamas

    2016-02-01

    Phospholipase C (PLC)-mediated hydrolysis of the limited pool of plasma membrane (PM) phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] requires replenishment from a larger pool of phosphatidylinositol (PtdIns) via sequential phosphorylation by PtdIns 4-kinases and phosphatidylinositol 4-phosphate (PtdIns4P) 5-kinases. Since PtdIns is synthesized in the endoplasmic reticulum (ER) and PtdIns(4,5)P2 is generated in the PM, it has been postulated that PtdIns transfer proteins (PITPs) provide the means for this lipid transfer function. Recent studies identified the large PITP protein, Nir2 as important for PtdIns transfer from the ER to the PM. It was also found that Nir2 was required for the transfer of phosphatidic acid (PtdOH) from the PM to the ER. In Nir2-depleted cells, activation of PLC leads to PtdOH accumulation in the PM and PtdIns synthesis becomes severely impaired. In quiescent cells, Nir2 is localized to the ER via interaction of its FFAT domain with ER-bound VAMP-associated proteins VAP-A and-B. After PLC activation, Nir2 also binds to the PM via interaction of its C-terminal domains with diacylglycerol (DAG) and PtdOH. Through these interactions, Nir2 functions in ER-PM contact zones. Mutations in VAP-B that have been identified in familial forms of amyotrophic lateral sclerosis (ALS or Lou-Gehrig's disease) cause aggregation of the VAP-B protein, which then impairs its binding to several proteins, including Nir2. These findings have shed new lights on the importance of non-vesicular lipid transfer of PtdIns and PtdOH in ER-PM contact zones with a possible link to a devastating human disease.

  4. Human cardiac phospholipase D activity is tightly controlled by phosphatidylinositol 4,5-bisphosphate.

    PubMed

    Kurz, Thomas; Kemken, Dorit; Mier, Kenneth; Weber, Isabel; Richardt, Gert

    2004-02-01

    Phospholipase D (PLD) plays a central role in receptor-mediated breakdown of choline phospholipids and formation of phosphatidic acid (PA), an important regulator of cardiac function. However, specific mechanisms that regulate myocardial PLD activity remain largely unknown, particularly in the human heart. We hypothesized that phosphatidylinositol 4,5-bisphosphate (PIP2), best known as substrate for phospholipase C (PLC) isozymes, plays a critical role in regulating myocardial PLD activity. We examined the effect of PIP2 on human myocardial PLD activity in vitro by utilizing a fluorescence HPLC assay. PIP2 increased 10-fold the maximal activity of a partially solubilized PLD from human atrial myocardium. PIP2-stimulated PLD activity was accompanied by a consecutive increase in diacylglycerol, indicating dephosphorylation of PA by PA phosphohydrolase. Likewise, phosphatidylinositol 3,4,5-trisphosphate, which is produced from PIP2 by phosphatidylinositol 3-kinase, increased PLD activity with about the same potency but with somewhat lower efficacy. In contrast, other phospholipids were ineffective, indicating that the action of PIP2 on PLD is highly specific. Neomycin, a high-affinity ligand of PIP2, inhibited PLD activity in human atrial myocardium, but had no effect on the activity of partially solubilized enzyme. The addition of PIP2 restored the sensitivity of solubilized PLD to neomycin inhibition, indicating that neomycin inhibits PLD activity by binding to endogenous PIP2. Our results demonstrate a critical role for PIP2 in human cardiac PLD activity and suggest that PIP2 synthesis (by phosphatidylinositol 4-phosphate 5-kinase) and hydrolysis (by PIP2-specific PLC) could be important determinants in regulating PLD signal transduction in the human heart. PMID:14871550

  5. Tau pathology-mediated presynaptic dysfunction.

    PubMed

    Moreno, H; Morfini, G; Buitrago, L; Ujlaki, G; Choi, S; Yu, E; Moreira, J E; Avila, J; Brady, S T; Pant, H; Sugimori, M; Llinás, R R

    2016-06-14

    Brain tauopathies are characterized by abnormal processing of tau protein. While somatodendritic tau mislocalization has attracted considerable attention in tauopathies, the role of tau pathology in axonal transport, connectivity and related dysfunctions remains obscure. We have previously shown using the squid giant synapse that presynaptic microinjection of recombinant human tau protein (htau42) results in failure of synaptic transmission. Here, we evaluated molecular mechanisms mediating this effect. Thus, the initial event, observed after htau42 presynaptic injection, was an increase in transmitter release. This event was mediated by calcium release from intracellular stores and was followed by a reduction in evoked transmitter release. The effect of htau42 on synaptic transmission was recapitulated by a peptide comprising the phosphatase-activating domain of tau, suggesting activation of phosphotransferases. Accordingly, findings indicated that htau42-mediated toxicity involves the activities of both GSK3 and Cdk5 kinases. PMID:27012611

  6. Ca2+ Influx through Store-operated Calcium Channels Replenishes the Functional Phosphatidylinositol 4,5-Bisphosphate Pool Used by Cysteinyl Leukotriene Type I Receptors.

    PubMed

    Alswied, Abdullah; Parekh, Anant B

    2015-12-01

    Oscillations in cytoplasmic Ca(2+) concentration are a universal mode of signaling following physiological levels of stimulation with agonists that engage the phospholipase C pathway. Sustained cytoplasmic Ca(2+) oscillations require replenishment of the membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2), the source of the Ca(2+)-releasing second messenger inositol trisphosphate. Here we show that cytoplasmic Ca(2+) oscillations induced by cysteinyl leukotriene type I receptor activation run down when cells are pretreated with Li(+), an inhibitor of inositol monophosphatases that prevents PIP2 resynthesis. In Li(+)-treated cells, cytoplasmic Ca(2+) signals evoked by an agonist were rescued by addition of exogenous inositol or phosphatidylinositol 4-phosphate (PI4P). Knockdown of the phosphatidylinositol 4-phosphate 5 (PIP5) kinases α and γ resulted in rapid loss of the intracellular Ca(2+) oscillations and also prevented rescue by PI4P. Knockdown of talin1, a protein that helps regulate PIP5 kinases, accelerated rundown of cytoplasmic Ca(2+) oscillations, and these could not be rescued by inositol or PI4P. In Li(+)-treated cells, recovery of the cytoplasmic Ca(2+) oscillations in the presence of inositol or PI4P was suppressed when Ca(2+) influx through store-operated Ca(2+) channels was inhibited. After rundown of the Ca(2+) signals following leukotriene receptor activation, stimulation of P2Y receptors evoked prominent inositol trisphosphate-dependent Ca(2+) release. Therefore, leukotriene and P2Y receptors utilize distinct membrane PIP2 pools. Our findings show that store-operated Ca(2+) entry is needed to sustain cytoplasmic Ca(2+) signaling following leukotriene receptor activation both by refilling the Ca(2+) stores and by helping to replenish the PIP2 pool accessible to leukotriene receptors, ostensibly through control of PIP5 kinase activity.

  7. Ca2+ Influx through Store-operated Calcium Channels Replenishes the Functional Phosphatidylinositol 4,5-Bisphosphate Pool Used by Cysteinyl Leukotriene Type I Receptors*

    PubMed Central

    Alswied, Abdullah; Parekh, Anant B.

    2015-01-01

    Oscillations in cytoplasmic Ca2+ concentration are a universal mode of signaling following physiological levels of stimulation with agonists that engage the phospholipase C pathway. Sustained cytoplasmic Ca2+ oscillations require replenishment of the membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2), the source of the Ca2+-releasing second messenger inositol trisphosphate. Here we show that cytoplasmic Ca2+ oscillations induced by cysteinyl leukotriene type I receptor activation run down when cells are pretreated with Li+, an inhibitor of inositol monophosphatases that prevents PIP2 resynthesis. In Li+-treated cells, cytoplasmic Ca2+ signals evoked by an agonist were rescued by addition of exogenous inositol or phosphatidylinositol 4-phosphate (PI4P). Knockdown of the phosphatidylinositol 4-phosphate 5 (PIP5) kinases α and γ resulted in rapid loss of the intracellular Ca2+ oscillations and also prevented rescue by PI4P. Knockdown of talin1, a protein that helps regulate PIP5 kinases, accelerated rundown of cytoplasmic Ca2+ oscillations, and these could not be rescued by inositol or PI4P. In Li+-treated cells, recovery of the cytoplasmic Ca2+ oscillations in the presence of inositol or PI4P was suppressed when Ca2+ influx through store-operated Ca2+ channels was inhibited. After rundown of the Ca2+ signals following leukotriene receptor activation, stimulation of P2Y receptors evoked prominent inositol trisphosphate-dependent Ca2+ release. Therefore, leukotriene and P2Y receptors utilize distinct membrane PIP2 pools. Our findings show that store-operated Ca2+ entry is needed to sustain cytoplasmic Ca2+ signaling following leukotriene receptor activation both by refilling the Ca2+ stores and by helping to replenish the PIP2 pool accessible to leukotriene receptors, ostensibly through control of PIP5 kinase activity. PMID:26468289

  8. Phosphoinositides Regulate Clathrin-Dependent Endocytosis at the Tip of Pollen Tubes in Arabidopsis and Tobacco[W

    PubMed Central

    Zhao, Yan; Yan, An; Feijó, José A.; Furutani, Masahiro; Takenawa, Tadaomi; Hwang, Inhwan; Fu, Ying; Yang, Zhenbiao

    2010-01-01

    Using the tip-growing pollen tube of Arabidopsis thaliana and Nicotiana tabacum as a model to investigate endocytosis mechanisms, we show that phosphatidylinositol-4-phosphate 5-kinase 6 (PIP5K6) regulates clathrin-dependent endocytosis in pollen tubes. Green fluorescent protein–tagged PIP5K6 was preferentially localized to the subapical plasma membrane (PM) in pollen tubes where it apparently converts phosphatidylinositol 4-phosphate (PI4P) to phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. RNA interference–induced suppression of PIP5K6 expression impaired tip growth and inhibited clathrin-dependent endocytosis in pollen tubes. By contrast, PIP5K6 overexpression induced massive aggregation of the PM in pollen tube tips. This PM abnormality was apparently due to excessive clathrin-dependent membrane invagination because this defect was suppressed by the expression of a dominant-negative mutant of clathrin heavy chain. These results support a role for PI(4,5)P2 in promoting early stages of clathrin-dependent endocytosis (i.e., membrane invagination). Interestingly, the PIP5K6 overexpression-induced PM abnormality was partially suppressed not only by the overexpression of PLC2, which breaks down PI(4,5)P2, but also by that of PI4Kβ1, which increases the pool of PI4P. Based on these observations, we propose that a proper balance between PI4P and PI(4,5)P2 is required for clathrin-dependent endocytosis in the tip of pollen tubes. PMID:21189293

  9. Mediator Deathwork

    ERIC Educational Resources Information Center

    Walter, Tony

    2005-01-01

    The most discussed and analyzed form of deathwork is the dyadic "therapist" [double arrow] "client" relationship, but this far from exhausts the various types of professional work involving the dead. Mediator deathwork is where the professional gleans or constructs information about the dead, edits and polishes it, and publicly presents the edited…

  10. Regulation of high molecular weight bovine brain neutral protease by phospholipids in vitro.

    PubMed

    Chauhan, V; Sheikh, A M; Chauhan, A; Spivack, W D; Fenko, M D; Malik, M N

    2005-04-01

    The activity of the heat stable, glycosylated high molecular weight bovine brain neutral protease (HMW protease) is differentially regulated by phospholipids. While phosphatidylcholine (PC), phosphatidylserine (PS) and phosphatidic acid (PA) had only marginal stimulatory effect (40-75%) on the activity of HMW protease, lysophoshatidylcholine (lysoPC) and lysophosphatidic acid (lysoPA) activated the enzyme by more than two-fold. Both lysoPC and lysoPA exhibited concentration-dependent saturation kinetics for the activation of HMW protease. Surprisingly, phosphoinositides (phosphatidylinositol, PI; phosphatidylinositol 4-phosphate, PIP; and phosphatidylinositol 4,5-bisphosphate, PIP2) modulated the activity of protease differently: activation of the enzyme was higher with PIP (90%) as compared to PI (21%), whereas PIP2 inhibited the enzyme (16%). The inhibition of the protease by PIP2 was concentration-dependent. During receptor-coupled cell activation, phospholipase A2 (PLA2) converts PC and PA to lysoPC and lysoPA, respectively; PI is converted to PIP2 by successive enzymatic phosphorylation by PI 4-kinase and PIP 5-kinase; and phospholipase C (PLC) degrades PIP2 to diacylglycerol and inositol 1,4,5-trisphosphate. Therefore, the data suggest that HMW protease may be coupled to cell signal transduction where PLA2, PI 4-kinase, PIP 5-kinase and PLC are involved. PMID:16010981

  11. Light-stimulated inositolphospholipid turnover in Samanea saman leaf pulvini

    SciTech Connect

    Morse, M.J.; Crain, R.C.; Satter, R.L.

    1987-10-01

    Leaflets of Samanea saman open and close rhythmically, driven by an endogenous circadian clock. Light has a rapid, direct effect on the movements and also rephases the rhythm. The authors investigated whether light signals might be mediated by increased inositolphospholipid turnover, a mechanism for signal transduction that is widely utilized in animal systems. Samanea motor organs (pulvini) labeled with (/sup 3/H)inositol were irradiated briefly (5-30 sec) with white light, and membrane-localized phosphatidylinositol phosphates and their aqueous breakdown products, the inositol phosphates, were examined. After a 15-sec or longer light pulse, labeled phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate decreased and their labeled metabolic products inositol 1,4-biphosphate and inositol 1,4,5-trisphosphate increased changes characteristic of inositolphospholipid turnover. The authors conclude that inositolphospholipid turnover may act as a phototransduction mechanism in Samanea pulvini in a manner that is similar to that reported in animal systems.

  12. EDR2 negatively regulates salicylic acid-based defenses and cell death during powdery mildew infections of Arabidopsis thaliana

    PubMed Central

    Vorwerk, Sonja; Schiff, Celine; Santamaria, Marjorie; Koh, Serry; Nishimura, Marc; Vogel, John; Somerville, Chris; Somerville, Shauna

    2007-01-01

    Background The hypersensitive necrosis response (HR) of resistant plants to avirulent pathogens is a form of programmed cell death in which the plant sacrifices a few cells under attack, restricting pathogen growth into adjacent healthy tissues. In spite of the importance of this defense response, relatively little is known about the plant components that execute the cell death program or about its regulation in response to pathogen attack. Results We isolated the edr2-6 mutant, an allele of the previously described edr2 mutants. We found that edr2-6 exhibited an exaggerated chlorosis and necrosis response to attack by three pathogens, two powdery mildew and one downy mildew species, but not in response to abiotic stresses or attack by the bacterial leaf speck pathogen. The chlorosis and necrosis did not spread beyond inoculated sites suggesting that EDR2 limits the initiation of cell death rather than its spread. The pathogen-induced chlorosis and necrosis of edr2-6 was correlated with a stimulation of the salicylic acid defense pathway and was suppressed in mutants deficient in salicylic acid signaling. EDR2 encodes a novel protein with a pleckstrin homology and a StAR transfer (START) domain as well as a plant-specific domain of unknown function, DUF1336. The pleckstrin homology domain binds to phosphatidylinositol-4-phosphate in vitro and an EDR2:HA:GFP protein localizes to endoplasmic reticulum, plasma membrane and endosomes. Conclusion EDR2 acts as a negative regulator of cell death, specifically the cell death elicited by pathogen attack and mediated by the salicylic acid defense pathway. Phosphatidylinositol-4-phosphate may have a role in limiting cell death via its effect on EDR2. This role in cell death may be indirect, by helping to target EDR2 to the appropriate membrane, or it may play a more direct role. PMID:17612410

  13. Phosphatidic acid regulation of PIPKI is critical for actin cytoskeletal reorganization.

    PubMed

    Roach, Akua N; Wang, Ziqing; Wu, Ping; Zhang, Feng; Chan, Robin B; Yonekubo, Yoshiya; Di Paolo, Gilbert; Gorfe, Alemayehu A; Du, Guangwei

    2012-12-01

    Type I phosphatidylinositol-4-phosphate 5-kinase (PIPKI) is the main enzyme generating the lipid second messenger phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], which has critical functions in many cellular processes, such as cytoskeletal reorganization, membrane trafficking, and signal transduction. All three members of the PIPKI family are activated by phosphatidic acid (PA). However, how PA regulates the activity and functions of PIPKI have not been fully elucidated. In this study, we identify a PA-binding site on PIPKIγ. Mutation of this site inhibited the PA-stimulated activity and membrane localization of PIPKIγ as well as the formation of actin comets and foci induced by PIPKIγ. We also demonstrate that phospholipase D (PLD) generates a pool of PA involved in PIPKIγ regulation by showing that PLD inhibitors blocked the membrane localization of PIPKIγ and its ability to induce actin cytoskeletal reorganization. Targeting the PIPKIγ PA-binding-deficient mutant to membranes by a membrane localization sequence failed to restore the actin reorganization activity of PIPKIγ, suggesting that PA binding is not only involved in recruiting PIPKIγ to membranes but also may induce a conformational change. Taken together, these results reveal a new molecular mechanism through which PA regulates PIPKI and provides direct evidence that PA is important for the localization and functions of PIPKI in intact cells. PMID:22991193

  14. Tuba stimulates intracellular N-WASP-dependent actin assembly.

    PubMed

    Kovacs, Eva M; Makar, Robert S; Gertler, Frank B

    2006-07-01

    Tuba is a multidomain scaffolding protein that links cytoskeletal dynamics and membrane trafficking pathways. The N-terminus of Tuba binds dynamin1, and the C-terminus contains domains that can interact with signaling pathways and cytoskeletal regulatory elements. We investigated Tuba localization, distribution and function in B16 melanoma cells. Tuba overexpression stimulated dorsal ruffles that occurred independently of dynamin function. Tuba expression induced actin-driven motility of small puncta that required the C-terminal SH3, GEF and BAR domains. Additionally, Tuba was recruited to lipid vesicles generated by overexpression of phosphatidylinositol-4-phosphate 5-kinase type Ialpha (PIP5Kalpha), localizing prominently to the head of the comets and at lower levels along the actin tail. We propose that Tuba facilitates dorsal ruffling of melanoma cells through direct interaction with actin-regulatory proteins and the recruitment of signaling molecules to lipid microdomains for the coordinated assembly of a cytoskeletal network. Knockdown of Tuba by RNA interference (RNAi) attenuated PIP5Kalpha-generated comet formation and the invasive behavior of B16 cells, implying that Tuba function is required for certain aspects of these processes. These results suggest first that Tuba-stimulated dorsal ruffling might represent a novel mechanism for the coordination of N-WASP-dependent cytoskeletal rearrangements and second that Tuba function is implicated in motility processes. PMID:16757518

  15. PIPKIγ targets to the centrosome and restrains centriole duplication.

    PubMed

    Xu, Qingwen; Zhang, Yuxia; Xiong, Xunhao; Huang, Yan; Salisbury, Jeffery L; Hu, Jinghua; Ling, Kun

    2014-03-15

    Centriole biogenesis depends on the polo-like kinase (PLK4) and a small group of structural proteins. The spatiotemporal regulation of these proteins at pre-existing centrioles is essential to ensure that centriole duplication occurs once per cell cycle. Here, we report that phosphatidylinositol 4-phosphate 5-kinase type-1 gamma (PIP5K1C, hereafter referred to as PIPKIγ) plays an important role in centriole fidelity. PIPKIγ localized in a ring-like pattern in the intermediate pericentriolar materials around the proximal end of the centriole in G1, S and G2 phases, but not in M phase. This localization was dependent upon an association with centrosomal protein of 152 KDa (CEP152). Without detaining cells in S or M phase, the depletion of PIPKIγ led to centriole amplification in a manner that was dependent upon PLK4 and spindle assembly abnormal protein 6 homolog (SAS6). The expression of exogenous PIPKIγ reduced centriole amplification that occurred as a result of endogenous PIPKIγ depletion, hydroxyurea treatment or PLK4 overexpression, suggesting that PIPKIγ is likely to function at the PLK4 level to restrain centriole duplication. Importantly, we found that PIPKIγ bound to the cryptic polo-box domain of PLK4 and that this binding reduced the kinase activity of PLK4. Together, our findings suggest that PIPKIγ is a novel negative regulator of centriole duplication, which acts by modulating the homeostasis of PLK4 activity.

  16. Phosphatidylinositol 4,5-bisphosphate triggers activation of focal adhesion kinase by inducing clustering and conformational changes

    PubMed Central

    Goñi, Guillermina M.; Epifano, Carolina; Boskovic, Jasminka; Camacho-Artacho, Marta; Zhou, Jing; Bronowska, Agnieszka; Martín, M. Teresa; Eck, Michael J.; Kremer, Leonor; Gräter, Frauke; Gervasio, Francesco Luigi; Perez-Moreno, Mirna; Lietha, Daniel

    2014-01-01

    Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase (NRTK) with key roles in integrating growth and cell matrix adhesion signals, and FAK is a major driver of invasion and metastasis in cancer. Cell adhesion via integrin receptors is well known to trigger FAK signaling, and many of the players involved are known; however, mechanistically, FAK activation is not understood. Here, using a multidisciplinary approach, including biochemical, biophysical, structural, computational, and cell biology approaches, we provide a detailed view of a multistep activation mechanism of FAK initiated by phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2]. Interestingly, the mechanism differs from canonical NRTK activation and is tailored to the dual catalytic and scaffolding function of FAK. We find PI(4,5)P2 induces clustering of FAK on the lipid bilayer by binding a basic region in the regulatory 4.1, ezrin, radixin, moesin homology (FERM) domain. In these clusters, PI(4,5)P2 induces a partially open FAK conformation where the autophosphorylation site is exposed, facilitating efficient autophosphorylation and subsequent Src recruitment. However, PI(4,5)P2 does not release autoinhibitory interactions; rather, Src phosphorylation of the activation loop in FAK results in release of the FERM/kinase tether and full catalytic activation. We propose that PI(4,5)P2 and its generation in focal adhesions by the enzyme phosphatidylinositol 4-phosphate 5-kinase type Iγ are important in linking integrin signaling to FAK activation. PMID:25049397

  17. Diacylglycerol kinase as a possible therapeutic target for neuronal diseases.

    PubMed

    Shirai, Yasuhito; Saito, Naoaki

    2014-04-07

    Diacylglycerol kinase (DGK) is a lipid kinase converting diacylglycerol to phosphatidic acid, and regulates many enzymes including protein kinase C, phosphatidylinositol 4-phosphate 5-kinase, and mTOR. To date, ten mammalian DGK subtypes have been cloned and divided into five groups, and they show subtype-specific tissue distribution. Therefore, each DGK subtype is thought to be involved in respective cellular responses by regulating balance of the two lipid messengers, diacylglycerol and phosphatidic acid. Indeed, the recent researches using DGK knockout mice have clearly demonstrated the importance of DGK in the immune system and its pathophysiological roles in heart and insulin resistance in diabetes. Especially, most subtypes show high expression in brain with subtype specific regional distribution, suggesting that each subtype has important and unique functions in brain. Recently, neuronal functions of some DGK subtypes have accumulated. Here, we introduce DGKs with their structural motifs, summarize the enzymatic properties and neuronal functions, and discuss the possibility of DGKs as a therapeutic target of the neuronal diseases.

  18. [Association of (N251S)-PIP5K2A with schizophrenic disorders: a study of the Russian population of Siberia].

    PubMed

    Fedorenko, O Iu; Rudikov, E V; Gavrilova, V A; Boiarko, E G; Semke, A V; Ivanova, S A

    2013-01-01

    The phosphatidylinositol-4-phosphate-5-kinase type IIa (PIP5K2A) gene has been proposed as a putative susceptibility gene for schizophrenia on both positional and functional grounds. The association between the (N251S)-PIP5K2A (rs10828317) variant and schizophrenia was found in German and Dutch populations but was not replicated in several other populations. The purpose of the study was to examine whether the previously implicated (N251S)-PIP5K2A variant influences susceptibility to schizophrenia in the Russian population of Siberia. Authors studied 355 patients with schizophrenic disorders from the Russian population of Siberia. The control group consisted of 100 healthy. Results confirm the association of the (N251S)-PIP5K2A (rs10828317) polymorphism with schizophrenia (p=0.04, OR=2.48, 95%CI=1.19--5.17 for the CC genotype). The association can be explained by the inability of mutant kinase to activate the phosphatidylinositol-4,5-biphosphate dependent proteins, including neuronal KCNQ channels and glutamate EAAT3 transporters, which leads to the lack of dopaminergic and glutamatergic control in schizophrenic patients carriers of this mutation.

  19. The importance of mediation

    SciTech Connect

    Nastri, W.H.

    1996-12-31

    Environmental mediation involving hazardous materials often includes a neutral, third party to assist other groups with resolving disputes or with negotiations. Most often, mediators facilitate discussion and suggest possible resolutions among parties, rather than advise as to what action must be taken to reach an agreement. There is opportunity for all sides to express grievances and frustrations as well as hearing possible solutions to resolve discrepancies. Most often, those involved with mediation attain a sense of confidence, competency, and satisfaction with the mediation process. An honest broker is an example of a third party mediator believed capable of assisting mediation in an unbiased manner. The opposing groups must be confident that an honest broker is credible and will provide his/her services to reach a satisfactory conclusion; therefore, the reputation of the mediator is crucial to the success of the mediation process.

  20. Bayesian Mediation Analysis

    ERIC Educational Resources Information Center

    Yuan, Ying; MacKinnon, David P.

    2009-01-01

    In this article, we propose Bayesian analysis of mediation effects. Compared with conventional frequentist mediation analysis, the Bayesian approach has several advantages. First, it allows researchers to incorporate prior information into the mediation analysis, thus potentially improving the efficiency of estimates. Second, under the Bayesian…

  1. Teaching Mediated Public Relations.

    ERIC Educational Resources Information Center

    Kent, Michael L.

    2001-01-01

    Discusses approaches to teaching a mediated public relations course, emphasizing the World Wide Web. Outlines five course objectives, assignments and activities, evaluation, texts, and lecture topics. Argues that students mastering these course objectives will understand ethical issues relating to media use, using mediated technology in public…

  2. Pathways to Peer Mediation.

    ERIC Educational Resources Information Center

    Singh, Dulcie

    Peer mediation programs in schools are an effective way for children to learn the cooperative skills of conflict solving. This paper outlines the implementation of an action research based mediation program within a primary school setting. It examines both the characteristics of successful implementation and the dilemmas of change agentry. A model…

  3. What Is Mediation?

    ERIC Educational Resources Information Center

    Consortium for Appropriate Dispute Resolution in Special Education (CADRE), Eugene, OR.

    This brief paper discusses the use of mediation as a method for resolving disagreements between schools or early intervention programs and parents of children with disabilities. It identifies benefits of mediation such as maintenance of an ongoing and positive relationship between the school and family, simple resolution of conflicts arising out…

  4. [Mediation in health].

    PubMed

    Decastello, Alice

    2008-02-10

    The author presents mediation as an alternative dispute resolution method. Mediation is a process where the parties are ready to settle their dispute out of court, by way of negotiation and with the involvement of an independent third person as mediator. In the mediation process the mediator shall not decide the dispute, nor examine the default or give legal advice or express his/her opinion - the mediator's duty is to help the parties bring their positions closer and come to a settlement agreement within a short time (120 days). The author gives a summary of the applications of the Hungarian Act on Mediation in Public Health and draws conclusions from the practical experience since entry into force of the legislation and illustrates the advantages of mediation over the court procedure (which may drag on for years). The primary advantages of mediation are that both the mediators and the parties are bound by the obligation of secrecy, the procedure is cheaper than the court proceedings, and the parties can "save their faces" because in mediation the winner-winner formula asserts itself - against lawsuits where the winner-loser positions are confronted. The author also analyses the specific data and information available so far. As for the future, the legislation needs to be amended at several points. It is particularly expedient to regulate the legal relationship between the insurance companies and the health service providers because the liability insurance may not cover the damages the courts adjudicate. And so some of the service providers may go bankrupt as the difference in excess of the upper limit of coverage - it might as well be up to HUF 5 million per case - shall be paid from own budget, to the charge of the upkeep costs. It is also required to review and amend the regulations on expert activities, just as it is inevitable to make data supply compulsory - otherwise it will be impossible to monitor the number of mediation procedures in health. At present

  5. [Mediation in health].

    PubMed

    Decastello, Alice

    2008-02-10

    The author presents mediation as an alternative dispute resolution method. Mediation is a process where the parties are ready to settle their dispute out of court, by way of negotiation and with the involvement of an independent third person as mediator. In the mediation process the mediator shall not decide the dispute, nor examine the default or give legal advice or express his/her opinion - the mediator's duty is to help the parties bring their positions closer and come to a settlement agreement within a short time (120 days). The author gives a summary of the applications of the Hungarian Act on Mediation in Public Health and draws conclusions from the practical experience since entry into force of the legislation and illustrates the advantages of mediation over the court procedure (which may drag on for years). The primary advantages of mediation are that both the mediators and the parties are bound by the obligation of secrecy, the procedure is cheaper than the court proceedings, and the parties can "save their faces" because in mediation the winner-winner formula asserts itself - against lawsuits where the winner-loser positions are confronted. The author also analyses the specific data and information available so far. As for the future, the legislation needs to be amended at several points. It is particularly expedient to regulate the legal relationship between the insurance companies and the health service providers because the liability insurance may not cover the damages the courts adjudicate. And so some of the service providers may go bankrupt as the difference in excess of the upper limit of coverage - it might as well be up to HUF 5 million per case - shall be paid from own budget, to the charge of the upkeep costs. It is also required to review and amend the regulations on expert activities, just as it is inevitable to make data supply compulsory - otherwise it will be impossible to monitor the number of mediation procedures in health. At present

  6. Metadata based mediator generation

    SciTech Connect

    Critchlow, T

    1998-03-01

    Mediators are a critical component of any data warehouse, particularly one utilizing partially materialized views; they transform data from its source format to the warehouse representation while resolving semantic and syntactic conflicts. The close relationship between mediators and databases, requires a mediator to be updated whenever an associated schema is modified. This maintenance may be a significant undertaking if a warehouse integrates several dynamic data sources. However, failure to quickly perform these updates significantly reduces the reliability of the warehouse because queries do not have access to the m current data. This may result in incorrect or misleading responses, and reduce user confidence in the warehouse. This paper describes a metadata framework, and associated software designed to automate a significant portion of the mediator generation task and thereby reduce the effort involved in adapting the schema changes. By allowing the DBA to concentrate on identifying the modifications at a high level, instead of reprogramming the mediator, turnaround time is reduced and warehouse reliability is improved.

  7. Phenomenologically Investigating Mediated "Nature"

    ERIC Educational Resources Information Center

    Adams, Tony E.

    2005-01-01

    During the summer of 2001 I worked as a bartender in Wyoming, two miles east of Yellowstone National Park. This opportunity provided me with unique experiences of "the wilderness" and as a result, allowed me to become aware of intricacies of living within a primarily simulated and mass mediated culture, i.e., the United States. Following tenets of…

  8. Mediation and Legal Literacy

    ERIC Educational Resources Information Center

    Tomlinson, Elizabeth C.

    2010-01-01

    This study uses fieldwork to investigate the sponsorship of legal literacy within a court mediation program. This examination of institutional involvement in literacy sponsorship demonstrates the ideological nature of literacy by showing the importance of context, investigating literacy-based relationships, and uncovering the intertwined nature of…

  9. Axionic mirage mediation

    SciTech Connect

    Nakamura, Shuntaro; Okumura, Ken-ichi; Yamaguchi, Masahiro

    2008-06-01

    Although mirage mediation is one of the most plausible mediation mechanisms of supersymmetry breaking, it suffers from two crucial problems. One is the {mu}/B{mu} problem, and the second is the cosmological one. The former stems from the fact that the B parameter tends to be comparable with the gravitino mass, which is 2 orders of magnitude larger than the other soft masses. The latter problem is caused by the decay of the modulus whose branching ratio into the gravitino pair is sizable. In this paper, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this axionic mirage mediation, it is shown that the Peccei-Quinn symmetry breaking scale is dynamically determined around 10{sup 10} GeV to 10{sup 12} GeV due to the supersymmetry breaking effects, and the {mu} problem can be solved naturally. Furthermore, in our model, the lightest supersymmetric particle (LSP) is the axino, that is, the superpartner of the axion. The overabundance of the LSPs due to decays of the modulus/gravitino, which is the most serious cosmological difficulty in the mirage mediation, can be avoided if the axino is sufficiently light. The next-LSPs (NLSPs) produced by the gravitino decay eventually decay into the axino LSPs, yielding the dominant component of the axinos remaining today. It is shown that the axino with a mass of O(100) MeV is naturally realized, which can constitute the dark matter of the Universe, with a free-streaming length of the order of 0.1 Mpc. The saxion, the real scalar component of the axion supermultiplet, can also be cosmologically harmless due to the dilution of the modulus decay. The lifetime of the NLSP is relatively long, but much shorter than 1 sec, when the big-bang nucleosynthesis commences. The decay of the NLSP would provide intriguing collider signatures.

  10. Mediating Divorce Disputes: Mediator Behaviors, Styles and Roles.

    ERIC Educational Resources Information Center

    Vanderkooi, Lois; Pearson, Jessica

    1983-01-01

    Reviews 35 cases involving contested child custody and visitation and generalizes about the techniques used by experienced divorce mediators to help couples reach resolutions to their differences. Discusses different ways mediators orient couples to mediation, gain their commitment, identify the issues, overcome emotional obstacles and generate…

  11. Mediation in Separation and Divorce.

    ERIC Educational Resources Information Center

    Grebe, Sarah Childs

    1986-01-01

    Discusses the fast growing profession of mediation for couples undergoing separation and divorce. Discusses questions of consumers concerning how the process works, how long it takes, and its costs and questions of professionals, concerning the process, the qualifications of mediators, and referral for mediation. (Author/ABB)

  12. [Mediation in schools].

    PubMed

    Mickley, Angela

    2006-01-01

    In this article the guiding questions concern the objectives and effectiveness of introducing mediation into an existing school culture of dominance, competition and selection. In addition the necessity will be shown of combining conflict resolution with organisational development and the introduction of a consensual ethics and behaviour code to attain sustainable results in creating a constructive and healthy school environment. Given scarce resources and little time the decisive role of artistic methods will be looked at in providing young people with flexible methods of expressing and negotiating their interests in a changing environment of values and power structures. Some aspects of the development of nonviolent communication, conflict resolution and mediation methods in schools in Germany will be focused on with special emphasis on the type of intervention used and its long term sustainable effects. PMID:17152896

  13. Phosphatidylinositol 4,5-bisphosphate formation in rabbit skeletal and heart muscle membranes.

    PubMed

    Varsányi, M; Messer, M; Brandt, N R; Heilmeyer, L M

    1986-08-14

    Incubation of rabbit skeletal muscle microsomes or isolated triads with gamma 32P-ATP/Mg2+ in the absence and in the presence of added phosphatidylinositol resulted in the formation of phosphatidylinositol 4-phosphate catalyzed by phosphatidylinositol kinase. When phosphatidylinositol 4-phosphate was added as exogenous substrate, phosphatidylinositol 4,5-bisphosphate was also formed demonstrating the presence of a membrane bound phosphatidylinositol 4-phosphate kinase. Triads were broken mechanically in a French press and separated on a continuous sucrose gradient. Incubation of these fractions with gamma 32P-ATP/Mg2+ resulted in a rapid labeling of phospholipid in a membrane fraction banding between transverse tubules and the terminal cisternae. Partial triad breakage and triad reformation experiments indicated that this phosphatidylinositol kinase was associated with T-tubules. When exogenous phosphatidylinositol 4-phosphate was employed as substrate phosphatidylinositol 4,5-bisphosphate and phosphatidic acid were formed, indicating the presence of all the enzymes of the polyphosphoinositide signaling system in this special membrane fraction. In contrast, heart muscle microsomes or plasma membranes can catalyze this reaction sequence from endogenous formed phosphatidylinositol 4-phosphate.

  14. Immune mediated liver failure

    PubMed Central

    Wang, Xiaojing; Ning, Qin

    2014-01-01

    Liver failure is a clinical syndrome of various etiologies, manifesting as jaundice, encephalopathy, coagulopathy and circulatory dysfunction, which result in subsequent multiorgan failure. Clinically, liver failure is classified into four categories: acute, subacute, acute-on-chronic and chronic liver failure. Massive hepatocyte death is considered to be the core event in the development of liver failure, which occurs when the extent of hepatocyte death is beyond the liver regenerative capacity. Direct damage and immune-mediated liver injury are two major factors involved in this process. Increasing evidence has suggested the essential role of immune-mediated liver injury in the pathogenesis of liver failure. Here, we review the evolved concepts concerning the mechanisms of immune-mediated liver injury in liver failure from human and animal studies. Both innate and adaptive immunity, especially the interaction of various immune cells and molecules as well as death receptor signaling system are discussed. In addition, we highlight the concept of “immune coagulation”, which has been shown to be related to the disease progression and liver injury exacerbation in HBV related acute-on-chronic liver failure. PMID:26417328

  15. An Alternative Framework for Defining Mediation.

    ERIC Educational Resources Information Center

    Collins, Linda M.; Graham, John W.; Flaherty, Brian P.

    1998-01-01

    Presents an alternative framework for evaluating mediated relationships. The distinguishing feature of mediation is that mediation involves a chain reaction. The definition presented emphasizes the intra-individual, time-ordered nature of mediation. (SLD)

  16. Cell Permeable Ratiometric Fluorescent Sensors for Imaging Phosphoinositides.

    PubMed

    Mondal, Samsuzzoha; Rakshit, Ananya; Pal, Suranjana; Datta, Ankona

    2016-07-15

    Phosphoinositides are critical cell-signal mediators present on the plasma membrane. The dynamic change of phosphoinositide concentrations on the membrane including clustering and declustering mediates signal transduction. The importance of phosphoinositides is scored by the fact that they participate in almost all cell-signaling events, and a defect in phosphoinositide metabolism is linked to multiple diseases including cancer, bipolar disorder, and type-2 diabetes. Optical sensors for visualizing phosphoinositide distribution can provide information on phosphoinositide dynamics. This exercise will ultimately afford a handle into understanding and manipulating cell-signaling processes. The major requirement in phosphoinositide sensor development is a selective, cell permeable probe that can quantify phosphoinositides. To address this requirement, we have developed short peptide-based ratiometric fluorescent sensors for imaging phosphoinositides. The sensors afford a selective response toward two crucial signaling phosphoinositides, phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) and phosphatidylinositol-4-phosphate (PI4P), over other anionic membrane phospholipids and soluble inositol phosphates. Dissociation constant values indicate up to 4 times higher probe affinity toward PI(4,5)P2 when compared to PI4P. Significantly, the sensors are readily cell-permeable and enter cells within 15 min of incubation as indicated by multiphoton excitation confocal microscopy. Furthermore, the sensors light up signaling phosphoinositides present both on the cell membrane and on organelle membranes near the perinuclear space, opening avenues for quantifying and monitoring phosphoinositide signaling.

  17. Structural basis for PI(4)P-specific membrane recruitment of the Legionella pneumophila effector DrrA/SidM.

    PubMed

    Del Campo, Claudia M; Mishra, Ashwini K; Wang, Yu-Hsiu; Roy, Craig R; Janmey, Paul A; Lambright, David G

    2014-03-01

    Recruitment of the Legionella pneumophila effector DrrA to the Legionella-containing vacuole, where it activates and AMPylates Rab1, is mediated by a P4M domain that binds phosphatidylinositol 4-phosphate [PI(4)P] with high affinity and specificity. Despite the importance of PI(4)P in Golgi trafficking and its manipulation by pathogens, the structural bases for PI(4)P-dependent membrane recruitment remain poorly defined. Here, we determined the crystal structure of a DrrA fragment including the P4M domain in complex with dibutyl PI(4)P and investigated the determinants of phosphoinositide recognition and membrane targeting. Headgroup recognition involves an elaborate network of direct and water-mediated interactions with basic and polar residues in the context of a deep, constrictive binding pocket. An adjacent hydrophobic helical element packs against the acyl chains and inserts robustly into PI(4)P-containing monolayers. The structural, biochemical, and biophysical data reported here support a detailed structural mechanism for PI(4)P-dependent membrane targeting by DrrA.

  18. Merlin Mediation System

    2001-10-16

    Merlin Mediation System (a.k.a., Merlin) is a set of reusable software components that provide seamless integration of information contained in multiple, heterogeneous data sources located across many computers. These software components utilize a combination of mediator and expert system technologies to provide intelligence for understanding and integrating data. Merlin provides a virtual database independent of operating systems, platforms, and user applications. Merlin in an implementation of "intelligent middleware" that solves data access and integration issues.more » Merlin resides between user applications and their independent data sources. a user application may be invoked via a Web browser or reside on an individual's workstation. The data sources can reside on multiple separate heterogeneous computer polatforms and may be recorded in a variety of formats (e.g., relational databases, flat files, object-oriented databases). Merlin creates a "virtual object database" so that the user application sees the data retrieved from the various sources as though it wre returned from a single, integrated database. In addition, Merlin provides advanced data instance integration capabilities such as object unification and fusion, abstraction, aggregation, and data and schema translations. It is important to note that Merlin is not bound to any single user application nor to any specific data source. Merlin's software components utilize a combination of mediator and expert system technologies to assure their adaptability for use by various disciplines. These software components accept domain-specific details (e.g., schema, mappings, expert system rules) as data from a "knowledge base". This enables the same software to be used for a variety of domains and user applications with no source code modifications or recompilations required.« less

  19. Copper mediated carbometalation reactions.

    PubMed

    Müller, D S; Marek, I

    2016-08-01

    Since the first discovery of carbocupration of alkynes in the 1970s a tremendous amount of research has been carried out in this field. The exceptionally high selectivities obtained attribute to the great synthetic value of carbocupration reactions. This tutorial review will present the most important features of carbocupration of alkynes and highlight the most relevant reviews. Then a comprehensive review of copper mediated carbometalation of cyclopropenes will follow. The latter method has received much attention over the last decade as it allows the highly selective construction of poly-substituted cyclopropanes which can be transformed into acyclic derivatives bearing one or multiple tertiary or quaternary carbon stereocenters. PMID:26808300

  20. Copper mediated carbometalation reactions.

    PubMed

    Müller, D S; Marek, I

    2016-08-01

    Since the first discovery of carbocupration of alkynes in the 1970s a tremendous amount of research has been carried out in this field. The exceptionally high selectivities obtained attribute to the great synthetic value of carbocupration reactions. This tutorial review will present the most important features of carbocupration of alkynes and highlight the most relevant reviews. Then a comprehensive review of copper mediated carbometalation of cyclopropenes will follow. The latter method has received much attention over the last decade as it allows the highly selective construction of poly-substituted cyclopropanes which can be transformed into acyclic derivatives bearing one or multiple tertiary or quaternary carbon stereocenters.

  1. Ferrofluid mediated nanocytometry.

    PubMed

    Kose, Ayse Rezzan; Koser, Hur

    2012-01-01

    We present a low-cost, flow-through nanocytometer that utilizes a colloidal suspension of non-functionalized magnetic nanoparticles for label-free manipulation and separation of microparticles. Our size-based separation is mediated by angular momentum transfer from magnetically excited ferrofluid particles to microparticles. The nanocytometer is capable of rapidly sorting and focusing two or more species, with up to 99% separation efficiency and a throughput of 3 × 10(4) particles/s per mm(2) of channel cross-section. The device is readily scalable and applicable to live cell sorting with biocompatible ferrofluids, offering competitive cytometer performance in a simple and inexpensive package. PMID:22076536

  2. Increasing Phosphatidylinositol (4,5)-Bisphosphate Biosynthesis Affects Basal Signaling and Chloroplast Metabolism in Arabidopsis thaliana

    PubMed Central

    Im, Yang Ju; Smith, Caroline M.; Phillippy, Brian Q.; Strand, Deserah; Kramer, David M.; Grunden, Amy M.; Boss, Wendy F.

    2014-01-01

    One challenge in studying the second messenger inositol(1,4,5)-trisphosphate (InsP3) is that it is present in very low amounts and increases only transiently in response to stimuli. To identify events downstream of InsP3, we generated transgenic plants constitutively expressing the high specific activity, human phosphatidylinositol 4-phosphate 5-kinase Iα (HsPIPKIα). PIP5K is the enzyme that synthesizes phosphatidylinositol (4,5)-bisphosphate (PtdIns(4,5)P2); this reaction is flux limiting in InsP3 biosynthesis in plants. Plasma membranes from transgenic Arabidopsis expressing HsPIPKIα had 2–3 fold higher PIP5K specific activity, and basal InsP3 levels in seedlings and leaves were >2-fold higher than wild type. Although there was no significant difference in photosynthetic electron transport, HsPIPKIα plants had significantly higher starch (2–4 fold) and 20% higher anthocyanin compared to controls. Starch content was higher both during the day and at the end of dark period. In addition, transcripts of genes involved in starch metabolism such as SEX1 (glucan water dikinase) and SEX4 (phosphoglucan phosphatase), DBE (debranching enzyme), MEX1 (maltose transporter), APL3 (ADP-glucose pyrophosphorylase) and glucose-6-phosphate transporter (Glc6PT) were up-regulated in the HsPIPKIα plants. Our results reveal that increasing the phosphoinositide (PI) pathway affects chloroplast carbon metabolism and suggest that InsP3 is one component of an inter-organelle signaling network regulating chloroplast metabolism. PMID:27135490

  3. Vac7p, a novel vacuolar protein, is required for normal vacuole inheritance and morphology.

    PubMed Central

    Bonangelino, C J; Catlett, N L; Weisman, L S

    1997-01-01

    During cell division, the vacuole of Saccharomyces cerevisiae partitions between mother and daughter cells. A portion of the parental vacuole membrane moves into the bud, and ultimately membrane scission divides the vacuole into two separate structures. Here we characterize two yeast mutations causing defects in vacuole membrane scission, vac7-1 and vac14-1. A third mutant, afab1-2 strain, isolated in a nonrelated screen (A. Yamamoto et al., Mol. Biol. Cell 6:525-539, 1995) shares the vacuolar phenotypes of the vac7-1 and vac14-1 strains. Unlike the wild type, mutant vacuoles are not multilobed structures; in many cases, a single vacuole spans both the mother and bud, with a distinct gap in the mother-bud neck. Thus, even where the membranes are closely opposed, vacuole fission is arrested. Simply enlarging the vacuole does not produce this mutant phenotype. An additional common phenotype of these mutants is a defect in vacuole acidification; however, vacuole scission in most other vacuole acidification mutants is normal. An alteration in vacuole membrane lipids could account for both the vacuole membrane scission and acidification defects. Because a directed screen has not identified additional class III complementation groups, it is likely that all three genes are involved in a similar process. Interestingly, FAB1, was previously shown to encode a putative phosphatidylinositol-4-phosphate 5-kinase. Moreover, overexpression of FAB1 suppresses the vac14-1 mutation, which suggests that VAC14 and FAB1 act at a common step. VAC7 encodes a novel 128-kDa protein that is localized at the vacuole membrane. This location of Vac7p is consistent with its involvement in vacuole morphology and inheritance. PMID:9372916

  4. RpkA, a Highly Conserved GPCR with a Lipid Kinase Domain, Has a Role in Phagocytosis and Anti-Bacterial Defense

    PubMed Central

    Riyahi, Tanja Y.; Frese, Frederike; Steinert, Michael; Omosigho, Napoleon N.; Glöckner, Gernot; Eichinger, Ludwig; Orabi, Benoit; Williams, Robin S. B.; Noegel, Angelika A.

    2011-01-01

    RpkA (Receptor phosphatidylinositol kinase A) is an unusual seven-helix transmembrane protein of Dictyostelium discoideum with a G protein coupled receptor (GPCR) signature and a C-terminal lipid kinase domain (GPCR-PIPK) predicted as a phosphatidylinositol-4-phosphate 5-kinase. RpkA-homologs are present in all so far sequenced Dictyostelidae as well as in several other lower eukaryotes like the oomycete Phytophthora, and in the Legionella host Acanthamoeba castellani. Here we show by immunofluorescence that RpkA localizes to endosomal membranes and is specifically recruited to phagosomes. RpkA interacts with the phagosomal protein complex V-ATPase as proteins of this complex co-precipitate with RpkA-GFP as well as with the GST-tagged PIPK domain of RpkA. Loss of RpkA leads to a defect in phagocytosis as measured by yeast particle uptake. The uptake of the pathogenic bacterium Legionella pneumophila was however unaltered whereas its intra-cellular replication was significantly enhanced in rpkA-. The difference between wild type and rpkA- was even more prominent when L. hackeliae was used. When we investigated the reason for the enhanced susceptibility for L. pneumophila of rpkA- we could not detect a difference in endosomal pH but rpkA- showed depletion of phosphoinositides (PIP and PIP2) when we compared metabolically labeled phosphoinositides from wild type and rpkA-. Furthermore rpkA- exhibited reduced nitrogen starvation tolerance, an indicator for a reduced autophagy rate. Our results indicate that RpkA is a component of the defense system of D. discoideum as well as other lower eukaryotes. PMID:22073313

  5. The multifaceted role of PIP2 in leukocyte biology.

    PubMed

    Tuosto, Loretta; Capuano, Cristina; Muscolini, Michela; Santoni, Angela; Galandrini, Ricciarda

    2015-12-01

    Phosphatidylinositol 4,5-bisphosphate (PIP2) represents about 1 % of plasma membrane phospholipids and behaves as a pleiotropic regulator of a striking number of fundamental cellular processes. In recent years, an increasing body of literature has highlighted an essential role of PIP2 in multiple aspects of leukocyte biology. In this emerging picture, PIP2 is envisaged as a signalling intermediate itself and as a membrane-bound regulator and a scaffold of proteins with specific PIP2 binding domains. Indeed PIP2 plays a key role in several functions. These include directional migration in neutrophils, integrin-dependent adhesion in T lymphocytes, phagocytosis in macrophages, lysosomes secretion and trafficking at immune synapse in cytolytic effectors and secretory cells, calcium signals and gene transcription in B lymphocytes, natural killer cells and mast cells. The coordination of these different aspects relies on the spatio-temporal organisation of distinct PIP2 pools, generated by the main PIP2 generating enzyme, phosphatidylinositol 4-phosphate 5-kinase (PIP5K). Three different isoforms of PIP5K, named α, β and γ, and different splice variants have been described in leukocyte populations. The isoform-specific coupling of specific isoforms of PIP5K to different families of activating receptors, including integrins, Fc receptors, toll-like receptors and chemokine receptors, is starting to be reported. Furthermore, PIP2 is turned over by multiple metabolising enzymes including phospholipase C (PLC) γ and phosphatidylinositol 3-kinase (PI3K) which, along with Rho family small G proteins, is widely involved in strategic functions within the immune system. The interplay between PIP2, lipid-modifying enzymes and small G protein-regulated signals is also discussed.

  6. Collaboration of AMPK and PKC to induce phosphorylation of Ser413 on PIP5K1B resulting in decreased kinase activity and reduced PtdIns(4,5)P2 synthesis in response to oxidative stress and energy restriction.

    PubMed

    van den Bout, Iman; Jones, David R; Shah, Zahid H; Halstead, Jonathan R; Keune, Willem-Jan; Mohammed, Shabaz; D'Santos, Clive S; Divecha, Nullin

    2013-11-01

    The spatial and temporal regulation of the second messenger PtdIns(4,5)P2 has been shown to be crucial for regulating numerous processes in the cytoplasm and in the nucleus. Three isoforms of PIP5K1 (phosphatidylinositol 4-phosphate 5-kinase), A, B and C, are responsible for the regulation of the major pools of cellular PtdIns(4,5)P2. PIP5K1B is negatively regulated in response to oxidative stress although it remains unclear which pathways regulate its activity. In the present study, we have investigated the regulation of PIP5K1B by protein phosphorylation. Using MS analysis, we identified 12 phosphorylation sites on PIP5K1B. We developed a phospho-specific antibody against Ser413 and showed that its phosphorylation was increased in response to treatment of cells with phorbol ester, H2O2 or energy restriction. Using inhibitors, we define a stress-dependent pathway that requires the activity of the cellular energy sensor AMPK (AMP-activated protein kinase) and PKC (protein kinase C) to regulate Ser413 phosphorylation. Furthermore, we demonstrate that PKC can directly phosphorylate Ser413 in vitro. Mutation of Ser413 to aspartate to mimic serine phosphorylation decreased both PIP5K1B activity in vitro and PtdIns(4,5)P2 synthesis in vivo. Our studies show that collaboration between AMPK and PKC dictates the extent of Ser413 phosphorylation on PIP5K1B and regulates PtdIns(4,5)P2 synthesis.

  7. Chronic alteration in phosphatidylinositol 4,5-bisphosphate levels regulates capsaicin and mustard oil responses

    PubMed Central

    Patil, Mayur J.; Belugin, Sergei; Akopian, Armen N.

    2011-01-01

    There is an agreement that acute (in minutes) hydrolysis and accumulation of phosphatidylinositol 4,5-bisphosphate (PIP2) modulate TRPV1 and TRPA1 activities. Since inflammation results in PIP2 depletion, persisting for long periods (hours-to-days) in pain models and in clinic, we examined whether chronic depletion and accumulation of PIP2 affects capsaicin and mustard oil responses. In addition we also wanted to evaluate whether the effects of PIP2 depend on TRPV1 and TRPA1 co-expression, and whether the PIP2 actions vary in expression cells versus sensory neurons. Chronic PIP2 production was stimulated by over-expression of phosphatidylinositol-4-phosphate-5-kinase, while PIP2-specific phospholipid 5′-phosphatase was selected to reduce plasma membrane levels of PIP2. Our results demonstrate that capsaicin (100 nM; CAP) responses and receptor tachyphylaxis are not significantly influenced by chronic changes in PIP2 levels in wild-type (WT) or TRPA1 null-mutant sensory neurons, as well as CHO cells expressing TRPV1 alone or with TRPA1. However, low concentrations of CAP (20 nM) produced a higher response after PIP2 depletion in cells containing TRPV1 alone, but not TRPV1 together with TRPA1. Mustard oil (25 μM; MO) responses were also not affected by PIP2 in WT sensory neurons and cells co-expressing TRPA1 and TRPV1. In contrast, PIP2 reduction leads to pronounced tachyphylaxis to MO in cells with both channels. Chronic effect of PIP2 on TRPA1 activity depends on presence of the TRPV1 channel and cell type (CHO vs. sensory neurons). In summary, chronic alterations in PIP2 levels regulate magnitude of CAP and MO responses, as well as MO-tachyphylaxis. This regulation depends on co-expression profile of TRPA1 and TRPV1 and cell type. PMID:21337373

  8. Gaugomaly mediation revisited

    NASA Astrophysics Data System (ADS)

    Gupta, Arpit; Kaplan, David E.; Zorawski, Tom

    2013-11-01

    Most generic models of hidden sector supersymmetry breaking do not feature singlets, and gauginos obtain masses from anomaly mediated supersymmetry breaking. If one desires a natural model, then the dominant contribution to scalar masses should be of the same order, i.e. also from AMSB. However, pure AMSB models suffer from the tachyonic slepton problem. Moreover, there is a large splitting between the gluino and the wino LSP masses resulting in tight exclusion limits from typical superpartner searches. We introduce messenger fields into this framework to obtain a hybrid theory of gauge and anomaly mediation, solving both problems simultaneously. Specifically, we find any number of vector-like messenger fields (allowed by GUT unification) compress the predicted gaugino spectrum when their masses come from the Giudice-Masiero mechanism. This more compressed spectrum is less constrained by LHC searches and allows for lighter gluinos. In addition to the model, we present gaugino pole mass equations that differ from (and correct) the original literature.

  9. Interpreter-mediated dentistry.

    PubMed

    Bridges, Susan; Drew, Paul; Zayts, Olga; McGrath, Colman; Yiu, Cynthia K Y; Wong, H M; Au, T K F

    2015-05-01

    The global movements of healthcare professionals and patient populations have increased the complexities of medical interactions at the point of service. This study examines interpreter mediated talk in cross-cultural general dentistry in Hong Kong where assisting para-professionals, in this case bilingual or multilingual Dental Surgery Assistants (DSAs), perform the dual capabilities of clinical assistant and interpreter. An initial language use survey was conducted with Polyclinic DSAs (n = 41) using a logbook approach to provide self-report data on language use in clinics. Frequencies of mean scores using a 10-point visual analogue scale (VAS) indicated that the majority of DSAs spoke mainly Cantonese in clinics and interpreted for postgraduates and professors. Conversation Analysis (CA) examined recipient design across a corpus (n = 23) of video-recorded review consultations between non-Cantonese speaking expatriate dentists and their Cantonese L1 patients. Three patterns of mediated interpreting indicated were: dentist designated expansions; dentist initiated interpretations; and assistant initiated interpretations to both the dentist and patient. The third, rather than being perceived as negative, was found to be framed either in response to patient difficulties or within the specific task routines of general dentistry. The findings illustrate trends in dentistry towards personalized care and patient empowerment as a reaction to product delivery approaches to patient management. Implications are indicated for both treatment adherence and the education of dental professionals. PMID:25828074

  10. Interpreter-mediated dentistry.

    PubMed

    Bridges, Susan; Drew, Paul; Zayts, Olga; McGrath, Colman; Yiu, Cynthia K Y; Wong, H M; Au, T K F

    2015-05-01

    The global movements of healthcare professionals and patient populations have increased the complexities of medical interactions at the point of service. This study examines interpreter mediated talk in cross-cultural general dentistry in Hong Kong where assisting para-professionals, in this case bilingual or multilingual Dental Surgery Assistants (DSAs), perform the dual capabilities of clinical assistant and interpreter. An initial language use survey was conducted with Polyclinic DSAs (n = 41) using a logbook approach to provide self-report data on language use in clinics. Frequencies of mean scores using a 10-point visual analogue scale (VAS) indicated that the majority of DSAs spoke mainly Cantonese in clinics and interpreted for postgraduates and professors. Conversation Analysis (CA) examined recipient design across a corpus (n = 23) of video-recorded review consultations between non-Cantonese speaking expatriate dentists and their Cantonese L1 patients. Three patterns of mediated interpreting indicated were: dentist designated expansions; dentist initiated interpretations; and assistant initiated interpretations to both the dentist and patient. The third, rather than being perceived as negative, was found to be framed either in response to patient difficulties or within the specific task routines of general dentistry. The findings illustrate trends in dentistry towards personalized care and patient empowerment as a reaction to product delivery approaches to patient management. Implications are indicated for both treatment adherence and the education of dental professionals.

  11. Protein- mediated enamel mineralization

    PubMed Central

    Moradian-Oldak, Janet

    2012-01-01

    Enamel is a hard nanocomposite bioceramic with significant resilience that protects the mammalian tooth from external physical and chemical damages. The remarkable mechanical properties of enamel are associated with its hierarchical structural organization and its thorough connection with underlying dentin. This dynamic mineralizing system offers scientists a wealth of information that allows the study of basic principals of organic matrix-mediated biomineralization and can potentially be utilized in the fields of material science and engineering for development and design of biomimetic materials. This chapter will provide a brief overview of enamel hierarchical structure and properties as well as the process and stages of amelogenesis. Particular emphasis is given to current knowledge of extracellular matrix protein and proteinases, and the structural chemistry of the matrix components and their putative functions. The chapter will conclude by discussing the potential of enamel for regrowth. PMID:22652761

  12. Colistin-mediated neurotoxicity

    PubMed Central

    Wadia, Subeer; Tran, Betty

    2014-01-01

    We describe a 51-year-old man who developed renal and neural toxicity after the administration of colistin. He developed respiratory apnoea, neuromuscular blockade and severe comatose encephalopathy with the lack of brainstem reflexes. After discontinuation of the antibiotic, he made a prompt recovery to his baseline neurological function. The case illustrates the importance of recognising the toxicities associated with colistin. Although recent literature details its nephrotoxicity, current data have been discordant with the rare cases of respiratory apnoea or neuromuscular blockade once cited over 30 years ago. Additionally, no cases have ever described the profound encephalopathy with lack of brainstem function described here. The awareness of colistin's potentially fatal effects must be kept in mind when administering this antibiotic. Vigilance of the encephalopathic picture can also facilitate the diagnosis of colistin-mediated neurotoxicity in a patient with altered mental status of otherwise unknown aetiology. PMID:25199193

  13. Radical-Mediated Fluoroalkylations.

    PubMed

    Cho, Eun Jin

    2016-02-01

    Recently, the development of eco-friendly radical processes has become of great interest in synthetic chemistry. In particular, visible-light photocatalysis has drawn tremendous attention for its environmental compatibility and versatility in promoting many synthetically important reactions. In addition, inorganic electrides as electron donors have emerged as new eco-friendly tools for radical transformations since they consist of non-toxic and naturally abundant main metals such as calcium. The design of new fluoroalkylation reactions has benefited greatly from recent advances in visible-light photocatalysis and the chemistry of inorganic electrides. Since adding fluoroalkyl groups can dramatically change the physical and chemical properties of organic compounds, using these processes to promote eco-friendly radical fluoroalkylations will have a major impact in areas such as pharmaceuticals, agrochemicals, and material sciences. This Personal Account reviews radical-mediated fluoroalkylations, such as trifluoromethylations and difluoroalkylations, recently developed in our laboratory. PMID:26497950

  14. Microbially mediated phosphine emission.

    PubMed

    Roels, Joris; Huyghe, Gwen; Verstraete, Willy

    2005-02-15

    There is still a lot of controversy in literature concerning the question whether a biochemical system exists enabling micro-organisms to reduce phosphate to phosphine gas. The search for so-called 'de novo synthesised' phosphine is complicated by the fact that soils, slurries, sludges, etc., which are often used as inocula, usually contain matrix bound phosphine (MBP). Matrix bound phosphine is a general term used to indicate non-gaseous reduced phosphorus compounds that are transformed into phosphine gas upon reaction with bases or acids. A study was carried out to compare the different digestion methods, used to transform matrix bound phosphine into phosphine gas. It was demonstrated that caustic and acidic digestion methods should be used to measure the matrix bound phosphine of the inoculum prior to inoculation to avoid false positive results concerning de novo synthesis. This is especially true if anthropogenically influenced inocula possibly containing minute steel or aluminium particles are used. The comparative study on different digestion methods also revealed that the fraction of phosphorus in mild steel, converted to phosphine during acid corrosion depended on the temperature. Following these preliminary studies, anaerobic growth experiments were set up using different inocula and media to study the emission of phosphine gas. Phosphine was detected in the headspace gases and its quantity and timeframe of emission depended on the medium composition, suggesting microbially mediated formation of the gas. The amount of phosphine emitted during the growth experiments never exceeded the bound phosphine present in inocula, prior to inoculation. Hence, de novo synthesis of phosphine from phosphate could not be demonstrated. Yet, microbially mediated conversion to phosphine of hitherto unknown reduced phosphorus compounds in the inoculum was evidenced. PMID:15713333

  15. Endosome-mediated autophagy

    PubMed Central

    Kondylis, Vangelis; van Nispen tot Pannerden, Hezder E.; van Dijk, Suzanne; ten Broeke, Toine; Wubbolts, Richard; Geerts, Willie J.; Seinen, Cor; Mutis, Tuna; Heijnen, Harry F.G.

    2013-01-01

    Activation of TLR signaling has been shown to induce autophagy in antigen-presenting cells (APCs). Using high-resolution microscopy approaches, we show that in LPS-stimulated dendritic cells (DCs), autophagosomes emerge from MHC class II compartments (MIICs) and harbor both the molecular machinery for antigen processing and the autophagosome markers LC3 and ATG16L1. This ENdosome-Mediated Autophagy (ENMA) appears to be the major type of autophagy in DCs, as similar structures were observed upon established autophagy-inducing conditions (nutrient deprivation, rapamycin) and under basal conditions in the presence of bafilomycin A1. Autophagosome formation was not significantly affected in DCs expressing ATG4BC74A mutant and atg4b−/− bone marrow DCs, but the degradation of the autophagy substrate SQSTM1/p62 was largely impaired. Furthermore, we demonstrate that the previously described DC aggresome-like LPS-induced structures (DALIS) contain vesicular membranes, and in addition to SQSTM1 and ubiquitin, they are positive for LC3. LC3 localization on DALIS is independent of its lipidation. MIIC-driven autophagosomes preferentially engulf the LPS-induced SQSTM1-positive DALIS, which become later degraded in autolysosomes. DALIS-associated membranes also contain ATG16L1, ATG9 and the Q-SNARE VTI1B, suggesting that they may represent (at least in part) a membrane reservoir for autophagosome expansion. We propose that ENMA constitutes an unconventional, APC-specific type of autophagy, which mediates the processing and presentation of cytosolic antigens by MHC class II machinery, and/or the selective clearance of toxic by-products of elevated ROS/RNS production in activated DCs, thereby promoting their survival. PMID:23481895

  16. Peer Mediation in Elementary Schools.

    ERIC Educational Resources Information Center

    Angaran, Sally; Beckwith, Kathy

    1999-01-01

    Minor disagreements can quickly escalate when a child feels threatened with losing face or fears retaliation. Peer-mediation programs can help students refocus their energies while learning communication skills they can use in other situations. The benefits of an Oregon elementary school's peer-mediation program are discussed. (MLH)

  17. Moral Functioning as Mediated Action

    ERIC Educational Resources Information Center

    Tappan, Mark B.

    2006-01-01

    In this paper, I argue that it is quite useful, both theoretically and empirically, to adopt a socio-cultural approach to the study of moral development. This entails viewing "moral functioning" as a form of mediated action, and moral development as the process by which persons gradually appropriate a variety of "moral mediational means". Mediated…

  18. Symbolic Mediation in Cognitive Activity

    ERIC Educational Resources Information Center

    Veraksa, Alexander N.

    2011-01-01

    This article used two studies to investigate sign and symbol mediation in children aged 8-11 years. In role play, children exist at one at the same time in objective reality and their representation of reality. We cannot observe their mental representation directly, but the issue of whether signs or symbols mediate early role play is an important…

  19. Dynamic formation of ER-PM junctions presents a lipid phosphatase to regulate phosphoinositides.

    PubMed

    Dickson, Eamonn J; Jensen, Jill B; Vivas, Oscar; Kruse, Martin; Traynor-Kaplan, Alexis E; Hille, Bertil

    2016-04-11

    Endoplasmic reticulum-plasma membrane (ER-PM) contact sites play an integral role in cellular processes such as excitation-contraction coupling and store-operated calcium entry (SOCE). Another ER-PM assembly is one tethered by the extended synaptotagmins (E-Syt). We have discovered that at steady state, E-Syt2 positions the ER and Sac1, an integral ER membrane lipid phosphatase, in discrete ER-PM junctions. Here, Sac1 participates in phosphoinositide homeostasis by limiting PM phosphatidylinositol 4-phosphate (PI(4)P), the precursor of PI(4,5)P2 Activation of G protein-coupled receptors that deplete PM PI(4,5)P2disrupts E-Syt2-mediated ER-PM junctions, reducing Sac1's access to the PM and permitting PM PI(4)P and PI(4,5)P2to recover. Conversely, depletion of ER luminal calcium and subsequent activation of SOCE increases the amount of Sac1 in contact with the PM, depleting PM PI(4)P. Thus, the dynamic presence of Sac1 at ER-PM contact sites allows it to act as a cellular sensor and controller of PM phosphoinositides, thereby influencing many PM processes. PMID:27044890

  20. Foot-and-mouth disease virus genome replication is unaffected by inhibition of type III phosphatidylinositol-4-kinases.

    PubMed

    Loundras, Eleni-Anna; Herod, Morgan R; Harris, Mark; Stonehouse, Nicola J

    2016-09-01

    Foot-and-mouth disease virus (FMDV) causes economically damaging infections of cloven-hooved animals, with outbreaks resulting in large financial losses to the agricultural industry. Due to the highly contagious nature of FMDV, research with infectious virus is restricted to a limited number of key facilities worldwide. FMDV sub-genomic replicons are therefore important tools for the study of viral translation and genome replication. The type III phosphatidylinositol-4-kinases (PI4Ks) are a family of enzymes that plays a key role in the production of replication complexes (viral factories) of a number of positive-sense RNA viruses and represents a potential target for novel pan-viral therapeutics. Here, we investigated whether type III PI4Ks also play a role in the FMDV life cycle, using a combination of FMDV sub-genomic replicons and bicistronic internal ribosome entry site (IRES)-containing reporter plasmids. We demonstrated that replication of the FMDV replicon was unaffected by inhibitors of either PI4KIIIα or PI4KIIIβ. However, PIK93, an inhibitor previously demonstrated to target PI4KIIIβ, did inhibit IRES-mediated protein translation. Consistent with this, cells transfected with FMDV replicons did not exhibit elevated levels of phosphatidylinositol-4-phosphate lipids. These results are therefore supportive of the hypothesis that FMDV genome replication does not require type III PI4K activity and does not activate these kinases. PMID:27323707

  1. Polyphosphoinositide metabolism in rat brain: effects of neuropeptides, neurotransmitters and cyclic nucleotides.

    PubMed

    Jolles, J; van Dongen, C J; ten Haaf, J; Gispen, W H

    1982-01-01

    This study describes effects of various peptides, neurotransmitters and cyclic nucleotides on brain polyphosphoinositide metabolism in vitro. The interconversion of the polyanionic inositol phospholipids was studied by incubation of a lysed crude mitochondrial/synaptosomal fraction with [gamma-32P]-ATP. The reference peptide ACTH1-24 stimulated the formation of radiolabelled phosphatidylinositol 4,5-diphosphate (TPI) and inhibited that of phosphatidic acid (PA). Substance P inhibited both TPI and PA labelling, whereas beta-endorphin inhibited that of PA without any effect on TPI. Morphine had no effect at any concentration tested, whereas high concentrations of naloxone inhibited the labelling of both PA and TPI. Naloxone did not counteract the effects of ACTH1-24. The other peptides tested (lysine 8-vasopressin and angiotensin II) were without any effect. Under the conditions used, adrenaline, noradrenaline and acetylcholine did not affect the labelling of the (poly)phosphoinositides. Both dopamine and serotonin, however, dose-dependently inhibited the formation of radiolabelled TPI and PA. Low concentrations of cAMP stimulated TPI, but higher concentrations had an overall inhibitory effect on the labelling of TPI, PA and especially phosphatidylinositol 4-phosphate (DPI). The cyclic nucleotide did not mediate or counteract the effects of ACTH, and cGMP was without any effect. These results are discussed in the light of current ideas on the mechanism of action of neuropeptides.

  2. Type II PI4-kinases control Weibel-Palade body biogenesis and von Willebrand factor structure in human endothelial cells

    PubMed Central

    Lopes da Silva, Mafalda; O'Connor, Marie N.; Kriston-Vizi, Janos; White, Ian J.; Al-Shawi, Raya; Simons, J. Paul; Mössinger, Julia; Haucke, Volker

    2016-01-01

    ABSTRACT Weibel-Palade bodies (WPBs) are endothelial storage organelles that mediate the release of molecules involved in thrombosis, inflammation and angiogenesis, including the pro-thrombotic glycoprotein von Willebrand factor (VWF). Although many protein components required for WPB formation and function have been identified, the role of lipids is almost unknown. We examined two key phosphatidylinositol kinases that control phosphatidylinositol 4-phosphate levels at the trans-Golgi network, the site of WPB biogenesis. RNA interference of the type II phosphatidylinositol 4-kinases PI4KIIα and PI4KIIβ in primary human endothelial cells leads to formation of an increased proportion of short WPB with perturbed packing of VWF, as exemplified by increased exposure of antibody-binding sites. When stimulated with histamine, these cells release normal levels of VWF yet, under flow, form very few platelet-catching VWF strings. In PI4KIIα-deficient mice, immuno-microscopy revealed that VWF packaging is also perturbed and these mice exhibit increased blood loss after tail cut compared to controls. This is the first demonstration that lipid kinases can control the biosynthesis of VWF and the formation of WPBs that are capable of full haemostatic function. PMID:27068535

  3. Arf6 controls retromer traffic and intracellular cholesterol distribution via a phosphoinositide-based mechanism

    PubMed Central

    Marquer, Catherine; Tian, Huasong; Yi, Julie; Bastien, Jayson; Dall'Armi, Claudia; Yang-Klingler, YoungJoo; Zhou, Bowen; Chan, Robin Barry; Di Paolo, Gilbert

    2016-01-01

    Small GTPases play a critical role in membrane traffic. Among them, Arf6 mediates transport to and from the plasma membrane, as well as phosphoinositide signalling and cholesterol homeostasis. Here we delineate the molecular basis for the link between Arf6 and cholesterol homeostasis using an inducible knockout (KO) model of mouse embryonic fibroblasts (MEFs). We find that accumulation of free cholesterol in the late endosomes/lysosomes of Arf6 KO MEFs results from mistrafficking of Niemann–Pick type C protein NPC2, a cargo of the cation-independent mannose-6-phosphate receptor (CI-M6PR). This is caused by a selective increase in an endosomal pool of phosphatidylinositol-4-phosphate (PI4P) and a perturbation of retromer, which controls the retrograde transport of CI-M6PR via sorting nexins, including the PI4P effector SNX6. Finally, reducing PI4P levels in KO MEFs through independent mechanisms rescues aberrant retromer tubulation and cholesterol mistrafficking. Our study highlights a phosphoinositide-based mechanism for control of cholesterol distribution via retromer. PMID:27336679

  4. Type II PI4-kinases control Weibel-Palade body biogenesis and von Willebrand factor structure in human endothelial cells.

    PubMed

    Lopes da Silva, Mafalda; O'Connor, Marie N; Kriston-Vizi, Janos; White, Ian J; Al-Shawi, Raya; Simons, J Paul; Mössinger, Julia; Haucke, Volker; Cutler, Daniel F

    2016-05-15

    Weibel-Palade bodies (WPBs) are endothelial storage organelles that mediate the release of molecules involved in thrombosis, inflammation and angiogenesis, including the pro-thrombotic glycoprotein von Willebrand factor (VWF). Although many protein components required for WPB formation and function have been identified, the role of lipids is almost unknown. We examined two key phosphatidylinositol kinases that control phosphatidylinositol 4-phosphate levels at the trans-Golgi network, the site of WPB biogenesis. RNA interference of the type II phosphatidylinositol 4-kinases PI4KIIα and PI4KIIβ in primary human endothelial cells leads to formation of an increased proportion of short WPB with perturbed packing of VWF, as exemplified by increased exposure of antibody-binding sites. When stimulated with histamine, these cells release normal levels of VWF yet, under flow, form very few platelet-catching VWF strings. In PI4KIIα-deficient mice, immuno-microscopy revealed that VWF packaging is also perturbed and these mice exhibit increased blood loss after tail cut compared to controls. This is the first demonstration that lipid kinases can control the biosynthesis of VWF and the formation of WPBs that are capable of full haemostatic function. PMID:27068535

  5. Building lipid 'PIPelines' throughout the cell by ORP/Osh proteins.

    PubMed

    Moser von Filseck, Joachim; Mesmin, Bruno; Bigay, Joëlle; Antonny, Bruno; Drin, Guillaume

    2014-10-01

    In eukaryotic cells, a sterol gradient exists between the early and late regions of the secretory pathway. This gradient seems to rely on non-vesicular transport mechanisms mediated by specialized carriers. The oxysterol-binding protein-related protein (ORP)/oxysterol-binding homology (Osh) family has been assumed initially to exclusively include proteins acting as sterol sensors/transporters and many efforts have been made to determine their mode of action. Our recent studies have demonstrated that some ORP/Osh proteins are not mere sterol transporters, but sterol/phosphatidylinositol 4-phosphate [PI(4)P] exchangers. They exploit the PI(4)P gradient at the endoplasmic reticulum (ER)/Golgi interface, or at membrane-contact sites between these compartments, to actively create a sterol gradient. Other recent reports have suggested that all ORP/Osh proteins bind PI(4)P and recognize a second lipid that is not necessary sterol. We have thus proposed that ORP/Osh proteins use PI(4)P gradients between organelles to convey various lipid species.

  6. Identification of possible adenosine receptors in vascular smooth muscle

    SciTech Connect

    Doctrow, S.R.

    1985-01-01

    Adenosine is a vasodilator and has been implicated in increased blood flow in tissues that undergo energy deficiency. During conditions such as hypoxia and ischemia, adenosine is produced and is said to increase blood flow by relaxing the vascular smooth muscle (VSM) lining the resistance vessels. The goal of this research was to identify receptors that might be responsible for adenosine-mediated VSM relaxation. When an insoluble fraction from calf aortic VSM was incubated with /sup 32/P-ATP, two components were phosphorylated. One was identified as myosin light chain by MW, pl, and immunoprecipitation. The other product was identified as phosphatidylinositol-4-phosphate (DPI) by tic. Both phosphorylations were inhibited by adenosine and by 5'-chloro-5'-deoxyadenosine (Cl-Ado). DPI production was much more sensitive to the nucleosides than was myosin phosphorylation. Neither inhibition involved change in cAMP production. Phosphatidylinositol (Pl) kinase in the VSM membranes required magnesium, was activated and solubilized by Triton X-100, and phosphorylated both endogenous and exogenous Pl. Cl-Ado inhibited Pl kinase in a manner competitive with respect to ATP and noncompetitive with respect to Pl. Adenosine and adenosine analogs modified in the ribose ring were inhibitors with potencies comparable to that of Cl-Ado. Adenine nucleotides and purine-modified adenosine analogs were weaker inhibitors than Cl-Ado.

  7. Dynamic formation of ER–PM junctions presents a lipid phosphatase to regulate phosphoinositides

    PubMed Central

    Jensen, Jill B.; Vivas, Oscar; Kruse, Martin; Traynor-Kaplan, Alexis E.; Hille, Bertil

    2016-01-01

    Endoplasmic reticulum–plasma membrane (ER–PM) contact sites play an integral role in cellular processes such as excitation–contraction coupling and store-operated calcium entry (SOCE). Another ER–PM assembly is one tethered by the extended synaptotagmins (E-Syt). We have discovered that at steady state, E-Syt2 positions the ER and Sac1, an integral ER membrane lipid phosphatase, in discrete ER–PM junctions. Here, Sac1 participates in phosphoinositide homeostasis by limiting PM phosphatidylinositol 4-phosphate (PI(4)P), the precursor of PI(4,5)P2. Activation of G protein–coupled receptors that deplete PM PI(4,5)P2 disrupts E-Syt2–mediated ER–PM junctions, reducing Sac1’s access to the PM and permitting PM PI(4)P and PI(4,5)P2 to recover. Conversely, depletion of ER luminal calcium and subsequent activation of SOCE increases the amount of Sac1 in contact with the PM, depleting PM PI(4)P. Thus, the dynamic presence of Sac1 at ER–PM contact sites allows it to act as a cellular sensor and controller of PM phosphoinositides, thereby influencing many PM processes. PMID:27044890

  8. Metabolites of the phospholipase D pathway regulate H2O2-induced filamin redistribution in endothelial cells.

    PubMed

    Hastie, L E; Patton, W F; Hechtman, H B; Shepro, D

    1998-03-15

    Hypoxia/reoxygenation injury to cultured endothelial cells results in cytoskeletal rearrangement and second messenger activation related to increased monolayer junctional permeability. Cytoskeletal rearrangement by reactive oxygen species may be related to specific activation of the phospholipase D (PLD) pathway. Human umbilical vein endothelial cell monolayers are exposed to H2O2 (100 microM) or metabolites of the PLD pathway for 1-60 min. Changes in cAMP levels, Ca2+ levels, PIP2 production, filamin distribution, and intercellular gap formation are then quantitated. H2O2-induced filamin translocation from the membrane to the cytosol occurs after 1-min H2O2 treatment, while intercellular gap formation significantly increases after 15 min. H2O2 and phosphatidic acid exposure rapidly decrease intracellular cAMP levels, while increasing PIP2 levels in a Ca2+-independent manner. H2O2-induced cAMP decreases are prevented by inhibiting phospholipase D. H2O2-induced cytoskeletal changes are prevented by inhibiting phospholipase D, phosphatidylinositol-4-phosphate kinase, phosphoinositide turnover, or by adding a synthetic peptide that binds PIP2. These data indicate that metabolites produced downstream of H2O2-induced PLD activation may mediate filamin redistribution and F-actin rearrangement.

  9. ITRACONAZOLE INHIBITS ENTEROVIRUS REPLICATION BY TARGETING THE OXYSTEROL-BINDING PROTEIN

    PubMed Central

    Strating, Jeroen R.P.M.; van der Linden, Lonneke; Albulescu, Lucian; Bigay, Joëlle; Arita, Minetaro; Delang, Leen; Leyssen, Pieter; van der Schaar, Hilde M.; Lanke, Kjerstin H.W.; Thibaut, Hendrik Jan; Ulferts, Rachel; Drin, Guillaume; Schlinck, Nina; Wubbolts, Richard W.; Sever, Navdar; Head, Sarah A.; Liu, Jun O.; Beachy, Philip A.; De Matteis, Maria A.; Shair, Matthew D.; Olkkonen, Vesa M.; Neyts, Johan; van Kuppeveld, Frank J.M.

    2015-01-01

    SUMMARY Itraconazole (ITZ) is a well-known antifungal agent that also has anti-cancer activity. In this study, we identified ITZ as a broad-spectrum inhibitor of enteroviruses (e.g. poliovirus, coxsackievirus, enterovirus-71, rhinovirus). We demonstrate that ITZ inhibits viral RNA replication by targeting oxysterol-binding protein (OSBP) and OSBP-related protein 4 (ORP4). Consistently, OSW-1, a specific OSBP/ORP4 antagonist, also inhibits enterovirus replication. Knockdown of OSBP inhibits virus replication whereas overexpression of OSBP or ORP4 counteracts the antiviral effects of ITZ and OSW-1. ITZ binds OSBP and inhibits its function, i.e. shuttling of cholesterol and phosphatidylinositol-4-phosphate between membranes, thereby likely perturbing the virus-induced membrane alterations essential for viral replication organelle formation. ITZ also inhibits hepatitis C virus replication, which also relies on OSBP. Together, these data implicate OSBP/ORP4 as novel molecular targets of ITZ and point to an essential role of OSBP/ORP4-mediated lipid exchange in virus replication that can be targeted by antiviral drugs. PMID:25640182

  10. OSBP-Related Protein Family in Lipid Transport Over Membrane Contact Sites

    PubMed Central

    Olkkonen, Vesa M.

    2015-01-01

    Increasing evidence suggests that oxysterol-binding protein-related proteins (ORPs) localize at membrane contact sites, which are high-capacity platforms for inter-organelle exchange of small molecules and information. ORPs can simultaneously associate with the two apposed membranes and transfer lipids across the interbilayer gap. Oxysterol-binding protein moves cholesterol from the endoplasmic reticulum to trans-Golgi, driven by the retrograde transport of phosphatidylinositol-4-phosphate (PI4P). Analogously, yeast Osh6p mediates the transport of phosphatidylserine from the endoplasmic reticulum to the plasma membrane in exchange for PI4P, and ORP5 and -8 are suggested to execute similar functions in mammalian cells. ORPs may share the capacity to bind PI4P within their ligand-binding domain, prompting the hypothesis that bidirectional transport of a phosphoinositide and another lipid may be a common theme among the protein family. This model, however, needs more experimental support and does not exclude a function of ORPs in lipid signaling. PMID:26715851

  11. 34 CFR 81.13 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Mediation. 81.13 Section 81.13 Education Office of the... Mediation. (a) Voluntary mediation is available for proceedings that are pending before the OALJ. (b) A... mediation by filing a motion with the ALJ assigned to the case. The OALJ arranges for a mediator if...

  12. 24 CFR 3288.35 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Mediation. 3288.35 Section 3288.35...-Administered States § 3288.35 Mediation. (a) Mediator. The dispute resolution provider will provide for the... identifies any other party that should be included in the mediation, the mediator will contact the...

  13. 29 CFR 35.32 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Mediation. (a) Referral to mediation. CRC will promptly refer to the Federal Mediation and Conciliation Service or the mediation agency designated by the Secretary of Health and Human Services under 45 CFR part... 29 Labor 1 2010-07-01 2010-07-01 true Mediation. 35.32 Section 35.32 Labor Office of the...

  14. 29 CFR 1202.1 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Mediation. 1202.1 Section 1202.1 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD RULES OF PROCEDURE § 1202.1 Mediation. The mediation..., or where conferences are refused. The National Mediation Board may proffer its services in case...

  15. 29 CFR 1203.1 - Mediation services.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Mediation services. 1203.1 Section 1203.1 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD APPLICATIONS FOR SERVICE § 1203.1 Mediation services. Applications for the mediation services of the National Mediation Board under section 5, First, of the...

  16. 22 CFR 143.33 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Mediation. 143.33 Section 143.33 Foreign... Mediation. (a) Referral of complaints for mediation. The agency will refer to the Federal Mediation and... participate in the mediation process to the extent necessary to reach an agreement or make an...

  17. Microbially mediated mineral carbonation

    NASA Astrophysics Data System (ADS)

    Power, I. M.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2010-12-01

    Mineral carbonation involves silicate dissolution and carbonate precipitation, which are both natural processes that microorganisms are able to mediate in near surface environments (Ferris et al., 1994; Eq. 1). (Ca,Mg)SiO3 + 2H2CO3 + H2O → (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Cyanobacteria are photoautotrophs with cell surface characteristics and metabolic processes involving inorganic carbon that can induce carbonate precipitation. This occurs partly by concentrating cations within their net-negative cell envelope and through the alkalinization of their microenvironment (Thompson & Ferris, 1990). Regions with mafic and ultramafic bedrock, such as near Atlin, British Columbia, Canada, represent the best potential sources of feedstocks for mineral carbonation. The hydromagnesite playas near Atlin are a natural biogeochemical model for the carbonation of magnesium silicate minerals (Power et al., 2009). Field-based studies at Atlin and corroborating laboratory experiments demonstrate the ability of a microbial consortium dominated by filamentous cyanobacteria to induce the precipitation of carbonate minerals. Phototrophic microbes, such as cyanobacteria, have been proposed as a means for producing biodiesel and other value added products because of their efficiency as solar collectors and low requirement for valuable, cultivable land in comparison to crops (Dismukes et al., 2008). Carbonate precipitation and biomass production could be facilitated using specifically designed ponds to collect waters rich in dissolved cations (e.g., Mg2+ and Ca2+), which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially mediated carbonate precipitation does not require large quantities of energy or chemicals needed for industrial systems that have been proposed for rapid carbon capture and storage via mineral carbonation (e.g., Lackner et al., 1995). Therefore, this biogeochemical approach may represent a readily

  18. Nanoparticle mediated micromotor motion.

    PubMed

    Liu, Mei; Liu, Limei; Gao, Wenlong; Su, Miaoda; Ge, Ya; Shi, Lili; Zhang, Hui; Dong, Bin; Li, Christopher Y

    2015-03-21

    In this paper, we report the utilization of nanoparticles to mediate the motion of a polymer single crystal catalytic micromotor. Micromotors have been fabricated by directly self-assembling functional nanoparticles (platinum and iron oxide nanoparticles) onto one or both sides of two-dimensional polymer single crystals. We show that the moving velocity of these micromotors in fluids can be readily tuned by controlling the nanoparticles' surface wettability and catalytic activity. A 3 times velocity increase has been achieved for a hydrophobic micromotor as opposed to the hydrophilic ones. Furthermore, we demonstrate that the catalytic activity of platinum nanoparticles inside the micromotor can be enhanced by their synergetic interactions with iron oxide nanoparticles and an electric field. Both strategies lead to dramatically increased moving velocities, with the highest value reaching ∼200 μm s(-1). By decreasing the nanoparticles' surface wettability and increasing their catalytic activity, a maximum of a ∼10-fold increase in the moving speed of the nanoparticle based micromotor can be achieved. Our results demonstrate the advantages of using nanoparticles in micromotor systems.

  19. The TGF-β pathway mediates doxorubicin effects on cardiac endothelial cells.

    PubMed

    Sun, Zuyue; Schriewer, Jill; Tang, Mingxin; Marlin, Jerry; Taylor, Frederick; Shohet, Ralph V; Konorev, Eugene A

    2016-01-01

    Elevated ALK4/5 ligands including TGF-β and activins have been linked to cardiovascular remodeling and heart failure. Doxorubicin (Dox) is commonly used as a model of cardiomyopathy, a condition that often precedes cardiovascular remodeling and heart failure. In 7-8-week-old C57Bl/6 male mice treated with Dox we found decreased capillary density, increased levels of ALK4/5 ligand and Smad2/3 transcripts, and increased expression of Smad2/3 transcriptional targets. Human cardiac microvascular endothelial cells (HCMVEC) treated with Dox also showed increased levels of ALK4/5 ligands, Smad2/3 transcriptional targets, a decrease in proliferation and suppression of vascular network formation in a HCMVEC and human cardiac fibroblasts co-culture assay. Our hypothesis is that the deleterious effects of Dox on endothelial cells are mediated in part by the activation of the TGF-β pathway. We used the inhibitor of ALK4/5 kinases SB431542 (SB) in concert with Dox to ascertain the role of TGF-β pathway activation in doxorubicin induced endothelial cell defects. SB prevented the suppression of HCMVEC proliferation in the presence of TGF-β2 and activin A, and alleviated the inhibition of HCMVEC proliferation by Dox. SB also prevented the suppression of vascular network formation in co-cultures of HCMVEC and human cardiac fibroblasts treated with Dox. Our results show that the inhibition of the TGF-β pathway alleviates the detrimental effects of Dox on endothelial cells in vitro.

  20. Mediator-Generated Pressure Tactics

    ERIC Educational Resources Information Center

    Byrnes, Joseph F.

    1978-01-01

    Two examples of bluff pressures (as opposed to real pressures) used by mediators to effect contract settlements are presented, along with advice to negotiators on avoiding or minimizing such tactics. (Author/IRT)

  1. Inflammatory mediators in acute pancreatitis.

    PubMed

    Bhatia, M; Brady, M; Shokuhi, S; Christmas, S; Neoptolemos, J P; Slavin, J

    2000-02-01

    Inflammatory mediators play a key role in acute pancreatitis and the resultant multiple organ dysfunction syndrome, which is the primary cause of death in this condition. Recent studies have confirmed the critical role played by inflammatory mediators such as TNF-alpha, IL-1beta, IL-6, IL-8, PAF, IL-10, C5a, ICAM-1, and substance P. The systemic effects of acute pancreatitis have many similarities to those of other conditions such as septicaemia, severe burns, and trauma. The delay between the onset of inflammation in the pancreas and the development of the systemic response makes acute pancreatitis an ideal experimental and clinical model with which to study the role of inflammatory mediators and to test novel therapies. Elucidation of the key mediators involved in the pathogenesis of acute pancreatitis will facilitate the development of clinically effective anti-inflammatory therapy.

  2. Lipid mediators in life science.

    PubMed

    Murakami, Makoto

    2011-01-01

    "Lipid mediators" represent a class of bioactive lipids that are produced locally through specific biosynthetic pathways in response to extracellular stimuli. They are exported extracellularly, bind to their cognate G protein-coupled receptors (GPCRs) to transmit signals to target cells, and are then sequestered rapidly through specific enzymatic or non-enzymatic processes. Because of these properties, lipid mediators can be regarded as local hormones or autacoids. Unlike proteins, whose information can be readily obtained from the genome, we cannot directly read out the information of lipids from the genome since they are not genome-encoded. However, we can indirectly follow up the dynamics and functions of lipid mediators by manipulating the genes encoding a particular set of proteins that are essential for their biosynthesis (enzymes), transport (transporters), and signal transduction (receptors). Lipid mediators are involved in many physiological processes, and their dysregulations have been often linked to various diseases such as inflammation, infertility, atherosclerosis, ischemia, metabolic syndrome, and cancer. In this article, I will give an overview of the basic knowledge of various lipid mediators, and then provide an example of how research using mice, gene-manipulated for a lipid mediator-biosynthetic enzyme, contributes to life science and clinical applications.

  3. 43 CFR 17.332 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., and Enforcement Procedures § 17.332 Mediation. (a) Referral of complaints for mediation. DOI will... it. The FMCS shall send the agreement to DOI. DOI, however, retains the right to monitor the... process without prior approval of the head of the mediation agency. (e) DOI will use the mediation...

  4. 7 CFR 900.108 - Mediator's report.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Mediator's report. 900.108 Section 900.108 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Mediator's report. The mediator, upon the completion of mediation proceedings, shall submit to...

  5. 45 CFR 1156.16 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Mediation. 1156.16 Section 1156.16 Public Welfare... Procedures § 1156.16 Mediation. (a) Referral of complaints for mediation. The Endowment will promptly refer all complaints to the agency designated by the Secretary of HHS to manage the mediation process...

  6. 10 CFR 1040.89-6 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Enforcement Procedures § 1040.89-6 Mediation. (a) Referral of complaints for mediation. DOE will refer to the Federal Mediation and Conciliation Service, in accordance with 45 CFR 90.43(c)(3), all complaints that: (1... 10 Energy 4 2010-01-01 2010-01-01 false Mediation. 1040.89-6 Section 1040.89-6 Energy...

  7. 7 CFR 780.9 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Mediation. 780.9 Section 780.9 Agriculture Regulations... PROGRAMS APPEAL REGULATIONS § 780.9 Mediation. (a) Any request for mediation must be submitted after... once: (1) If resolution of an adverse decision is not achieved in mediation, a participant may...

  8. 38 CFR 18.543 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Mediation. 18.543 Section... Enforcement Procedures § 18.543 Mediation. (a) Referral of complaints for mediation. VA will refer to the Federal Mediation and Conciliation Service all complaints that: (1) Fall within the jurisdiction of...

  9. 24 CFR 146.35 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Mediation. 146.35 Section 146.35... ASSISTANCE Investigation, Settlement, and Enforcement Procedures § 146.35 Mediation. (a) HUD shall refer to the Federal Mediation and Conciliation Service, a mediation agency designated by the Secretary...

  10. Mediation in Schools: Tapping the Potential

    ERIC Educational Resources Information Center

    Hendry, Richard

    2010-01-01

    This article explores the developing role of mediation as a conflict resolution process in schools. It gives an accepted definition and clarifies the purposes of mediation, outlining the range of contexts in and beyond schools in which mediation is already offered as a formal intervention. The typical process of mediation itself is described. The…

  11. 22 CFR 218.33 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Mediation. 218.33 Section 218.33 Foreign... § 218.33 Mediation. (a) Referral of complaints for mediation. The agency will refer to the Federal Mediation and Conciliation Service all complaints that: (1) fall within the jurisdiction of...

  12. 14 CFR 1252.402 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Mediation. 1252.402 Section 1252.402... Procedures § 1252.402 Mediation. (a) Referral of complaints for mediation. NASA will refer to the Federal Mediation and Conciliation Service all complaints that: (1) Fall within the jurisdiction of the Act...

  13. 15 CFR 930.111 - OCRM mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false OCRM mediation. 930.111 Section 930... FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Secretarial Mediation § 930.111 OCRM mediation. The availability of mediation does not preclude use by the parties of alternative means...

  14. 10 CFR 4.333 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Mediation. 4.333 Section 4.333 Energy NUCLEAR REGULATORY... Investigation, Conciliation, and Enforcement Procedures § 4.333 Mediation. (a) Referral of complaints for mediation. NRC will refer to a mediation agency designated by the Secretary of the Department of Health...

  15. Mediation and Counseling Services: A Viable Partnership

    ERIC Educational Resources Information Center

    Hodges, Shannon

    2009-01-01

    Mediation has become common in many areas of society, including marital dissolution, community disputes, governmental agencies, and business and industry. Though higher education has been slower than society to adopt mediation services, campus mediation is becoming increasingly more common. This article explains why mediation is a viable…

  16. 15 CFR 20.12 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Mediation. 20.12 Section 20.12... Procedures § 20.12 Mediation. (a) DOC will refer to a mediation service designated by the Secretary all... further processing. (b) Both the complainant and the recipient shall participate in the mediation...

  17. 45 CFR 91.43 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Mediation. 91.43 Section 91.43 Public Welfare... Enforcement Procedures § 91.43 Mediation. (a) HHS will promptly refer to a mediation agency designated by the... mediation process to the extent necessary to reach an agreement or make an informed judgment that...

  18. 34 CFR 110.32 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Mediation. 110.32 Section 110.32 Education Regulations..., Conciliation, and Enforcement Procedures § 110.32 Mediation. (a) ED promptly refers to the Federal Mediation and Conciliation Service or to the mediation agency designated by the Secretary of Health and...

  19. 7 CFR 900.108 - Mediator's report.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Mediator's report. 900.108 Section 900.108 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Mediator's report. The mediator, upon the completion of mediation proceedings, shall submit to...

  20. Mediation Analysis in Psychosomatic Medicine Research

    PubMed Central

    Lockhart, Ginger; MacKinnon, David P.; Ohlrich, Vanessa

    2012-01-01

    This article presents an overview of statistical mediation analysis and its application to psychosomatic medicine research. The article begins with a description of the major approaches to mediation analysis and an evaluation of the strengths and limits of each. Emphasis is placed on longitudinal mediation models, and an application using latent growth modeling is presented. The article concludes with a description of recent developments in mediation analysis and suggestions for the use of mediation for future work in psychosomatic medicine research. PMID:21148809

  1. Conflict Resolution in Special Education and Section 504 through Mediation. Mediators Manual [and] School Information.

    ERIC Educational Resources Information Center

    Copenhaver, John

    This manual is designed to familiarize mediators with the mediation process and what will occur during a mediation session. Information is provided on the following topics: (1) mediation in special education under the Individuals with Disabilities Education Act and under Section 504 of the Rehabilitation Act of 1973; (2) advantages of mediation;…

  2. Nursing as textually mediated reality.

    PubMed

    Cheek, J; Rudge, T

    1994-11-01

    Nursing and nursing practice both construct and are in turn constructed by the context in which they operate. Texts plays a central part in that construction. As such, nursing and nursing practice can be considered to represent a reality that is textually mediated. This paper explores the notion of nursing as a textually mediated reality and offers the reader the possibility of engaging in reflection on what implications this has for nursing and their own nursing practice. The analyses provided draw on aspects of the work of both Foucault and Derrida. Foucault's notion of discourse provides a vehicle for the exploration of nursing as textually mediated, as does Derrida's concept of binary oppositions. The paper thus illustrates some of the possibilities afforded nursing by poststructural analyses. In particular it does this by exploring one of the central textual constructions, impacting on the way that nursing and nursing practice are conceptualized, the mind/body binary opposition. PMID:7850620

  3. Radical-Mediated Enzymatic Polymerizations.

    PubMed

    Zavada, Scott R; Battsengel, Tsatsral; Scott, Timothy F

    2016-01-01

    Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes--catalytic proteins--owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particularly oxidases and peroxidases, for generating radicals via reduction-oxidation mechanisms is especially common for initiating radical-mediated polymerization reactions, including vinyl chain-growth polymerization, atom transfer radical polymerization, thiol-ene step-growth polymerization, and polymerization via oxidative coupling. While enzyme-mediated polymerization is useful for the production of materials intended for subsequent use, it is especially well-suited for in situ polymerizations, where the polymer is formed in the place where it will be utilized. Such polymerizations are especially useful for biomedical adhesives and for sensing applications. PMID:26848652

  4. Gauge mediated mini-split

    NASA Astrophysics Data System (ADS)

    Cohen, Timothy; Craig, Nathaniel; Knapen, Simon

    2016-03-01

    We propose a simple model of split supersymmetry from gauge mediation. This model features gauginos that are parametrically a loop factor lighter than scalars, accommodates a Higgs boson mass of 125 GeV, and incorporates a simple solution to the μ- b μ problem. The gaugino mass suppression can be understood as resulting from collective symmetry breaking. Imposing collider bounds on μ and requiring viable electroweak symmetry breaking implies small a-terms and small tan β — the stop mass ranges from 105 to 108 GeV. In contrast with models with anomaly + gravity mediation (which also predict a one-loop loop suppression for gaugino masses), our gauge mediated scenario predicts aligned squark masses and a gravitino LSP. Gluinos, electroweakinos and Higgsinos can be accessible at the LHC and/or future colliders for a wide region of the allowed parameter space.

  5. Radical-Mediated Enzymatic Polymerizations

    PubMed Central

    Zavada, Scott R.; Battsengel, Tsatsral; Scott, Timothy F.

    2016-01-01

    Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes―catalytic proteins―owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particularly oxidases and peroxidases, for generating radicals via reduction-oxidation mechanisms is especially common for initiating radical-mediated polymerization reactions, including vinyl chain-growth polymerization, atom transfer radical polymerization, thiol–ene step-growth polymerization, and polymerization via oxidative coupling. While enzyme-mediated polymerization is useful for the production of materials intended for subsequent use, it is especially well-suited for in situ polymerizations, where the polymer is formed in the place where it will be utilized. Such polymerizations are especially useful for biomedical adhesives and for sensing applications. PMID:26848652

  6. Fracture healing and lipid mediators.

    PubMed

    O'Connor, J Patrick; Manigrasso, Michaele B; Kim, Brian D; Subramanian, Sangeeta

    2014-01-01

    Lipid mediators regulate bone regeneration during fracture healing. Prostaglandins and leukotrienes are well-known lipid mediators that regulate inflammation and are synthesized from the Ω-6 fatty acid, arachidonic acid. Cyclooxygenase (COX-1 or COX-2) and 5-lipoxygenase (5-LO) catalyze the initial enzymatic steps in the synthesis of prostaglandins and leukotrienes, respectively. Inhibition or genetic ablation of COX-2 activity impairs fracture healing in animal models. Genetic ablation of COX-1 does not affect the fracture callus strength in mice, suggesting that COX-2 activity is primarily responsible for regulating fracture healing. Inhibition of cyclooxygenase activity with nonsteroidal anti-inflammatory drugs (NSAIDs) is performed clinically to reduce heterotopic ossification, although clinical evidence that NSAID treatment impairs fracture healing remains controversial. In contrast, inhibition or genetic ablation of 5-LO activity accelerates fracture healing in animal models. Even though prostaglandins and leukotrienes regulate inflammation, loss of COX-2 or 5-LO activity appears to primarily affect chondrogenesis during fracture healing. Prostaglandin or prostaglandin analog treatment, prostaglandin-specific synthase inhibition and prostaglandin or leukotriene receptor antagonism also affect callus chondrogenesis. Unlike the Ω-6-derived lipid mediators, lipid mediators derived from Ω-3 fatty acids, such as resolvin E1 (RvE1), have anti-inflammatory activity. In vivo, RvE1 can inhibit osteoclastogenesis and limit bone resorption. Although Ω-6 and Ω-3 lipid mediators have clear-cut effects on inflammation, the role of these lipid mediators in bone regeneration is more complex, with apparent effects on callus chondrogenesis and bone remodeling. PMID:24795811

  7. Water-Mediated Hydrophobic Interactions

    NASA Astrophysics Data System (ADS)

    Ben-Amotz, Dor

    2016-05-01

    Hydrophobic interactions are driven by the combined influence of the direct attraction between oily solutes and an additional water-mediated interaction whose magnitude (and sign) depends sensitively on both solute size and attraction. The resulting delicate balance can lead to a slightly repulsive water-mediated interaction that drives oily molecules apart rather than pushing them together and thus opposes their direct (van der Waals) attraction for each other. As a consequence, competing solute size-dependent crossovers weaken hydrophobic interactions sufficiently that they are only expected to significantly exceed random thermal energy fluctuations for processes that bury more than ˜1 nm2 of water-exposed area.

  8. Dynamical Messengers for Gauge Mediation

    SciTech Connect

    Hook, Anson; Torroba, Gonzalo; /SLAC /Stanford U., Phys. Dept.

    2011-08-17

    We construct models of indirect gauge mediation where the dynamics responsible for breaking supersymmetry simultaneously generates a weakly coupled subsector of messengers. This provides a microscopic realization of messenger gauge mediation where the messenger and hidden sector fields are unified into a single sector. The UV theory is SQCD with massless and massive quarks plus singlets, and at low energies it flows to a weakly coupled quiver gauge theory. One node provides the primary source of supersymmetry breaking, which is then transmitted to the node giving rise to the messenger fields. These models break R-symmetry spontaneously, produce realistic gaugino and sfermion masses, and give a heavy gravitino.

  9. Notch-Mediated Cell Adhesion

    PubMed Central

    Murata, Akihiko; Hayashi, Shin-Ichi

    2016-01-01

    Notch family members are generally recognized as signaling molecules that control various cellular responses in metazoan organisms. Early fly studies and our mammalian studies demonstrated that Notch family members are also cell adhesion molecules; however, information on the physiological roles of this function and its origin is limited. In this review, we discuss the potential present and ancestral roles of Notch-mediated cell adhesion in order to explore its origin and the initial roles of Notch family members dating back to metazoan evolution. We hypothesize that Notch family members may have initially emerged as cell adhesion molecules in order to mediate multicellularity in the last common ancestor of metazoan organisms. PMID:26784245

  10. Eicosanoids mediate insect hemocyte migration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hemocyte chemotaxis toward infection and wound sites is an essential component of insect defense reactions, although the biochemical signal mechanisms responsible for mediating chemotaxis in insect cells are not well understood. Here we report on the outcomes of experiments designed to test the hyp...

  11. Re/Mediating Adolescent Literacies.

    ERIC Educational Resources Information Center

    Elkins, John, Ed.; Luke, Allan, Ed.

    Suggesting that teaching in New Times requires that educators read and re/mediate the social relations, the cultural knowledges, and the relationships of power between adolescents and their social, biological, and semiotic universes, this collection of essays offers new ways of seeing and talking about adolescents and their literacies. Most of the…

  12. Mediated Modeling in Science Education

    ERIC Educational Resources Information Center

    Halloun, Ibrahim A.

    2007-01-01

    Following two decades of corroboration, modeling theory is presented as a pedagogical theory that promotes mediated experiential learning of model-laden theory and inquiry in science education. Students develop experiential knowledge about physical realities through interplay between their own ideas about the physical world and particular patterns…

  13. Mediation and the Electronic World.

    ERIC Educational Resources Information Center

    Swan, John; And Others

    1992-01-01

    Three articles discuss the issue of the mediator's role in the library of the electronic age. Topics addressed include computer-assisted instruction; online catalogs; computer networks; professional identity; reference service and bibliographic instruction; CD-ROMs; online systems; personal home microcomputers; Internet and list servers;…

  14. Counterpoint: Response to Mediator Caraway.

    ERIC Educational Resources Information Center

    Gregory, Gordon A.; Heinen, Mark

    1991-01-01

    In the Fall 1989 issue, Caraway discussed the advantages of grievance mediation, compared with arbitration. This article reexamines the issue from the viewpoint of the individual grievant and points to recent conflicting developments in the National Labor Relations Board's deferral doctrine. An introduction by Perry A. Zirkel summarizes the…

  15. Mediation: A Violence Prevention Approach.

    ERIC Educational Resources Information Center

    Conflict Resolution Unlimited, Inc., Bellevue, WA.

    Young people need help in learning alternative dispute resolution skills. A program that aims to do this, set in a context of preventing violent behavior, is presented here. It is structured into sixteen 45-minute sessions which can be presented by one teacher. The training is organized around the following seven themes: The Mediation Process,…

  16. Divorce Mediator: A New Role

    ERIC Educational Resources Information Center

    Haynes, John M.

    1978-01-01

    In response to soaring divorce rates and liberalized divorce laws, the author proposes a new role for social workers--divorce mediator. Social work skills can be used to lessen the pain couples who are dissolving marriage at the same time that husband and wife are helped to face the future. (Author)

  17. Mediation Works: An Action Research Study Evaluating the Peer Mediation Program from the Eyes of Mediators and Faculty

    ERIC Educational Resources Information Center

    Cook, Jacqueline Yvonne; Boes, Susan R.

    2013-01-01

    A literature review was conducted to understand how mediators and faculty view a Peer Mediation Program (PMP). The review identified four subgroups: mediators, teachers, administrators, and school counselors as well as their views on the success or lack of success of PMPs. The research also reflects how to best engage stakeholders in the mediation…

  18. Ratio-of-Mediator-Probability Weighting for Causal Mediation Analysis in the Presence of Treatment-by-Mediator Interaction

    ERIC Educational Resources Information Center

    Hong, Guanglei; Deutsch, Jonah; Hill, Heather D.

    2015-01-01

    Conventional methods for mediation analysis generate biased results when the mediator--outcome relationship depends on the treatment condition. This article shows how the ratio-of-mediator-probability weighting (RMPW) method can be used to decompose total effects into natural direct and indirect effects in the presence of treatment-by-mediator…

  19. Nodal-mediated epigenesis requires dynamin-mediated endocytosis

    PubMed Central

    Ertl, Robin P.; Robertson, Anthony J.; Saunders, Diane; Coffman, James A.

    2011-01-01

    Nodal proteins are diffusible morphogens that drive pattern formation via short-range feedback activation coupled to long-range Lefty-mediated inhibition. In the sea urchin embryo, specification of the secondary (oral-aboral) axis occurs via zygotic expression of nodal, which is localized to the prospective oral ectoderm at early blastula stage. In mid-blastula stage embryos treated with low micromolar nickel or zinc, nodal expression expands progressively beyond the confines of this localized domain to encompass the entire equatorial circumference of the embryo, producing radialized embryos lacking an oral-aboral axis. RNAseq analysis of embryos treated with nickel, zinc or cadmium (which does not radialize embryos) showed that several genes involved in endocytosis were similarly perturbed by nickel and zinc but not cadmium. Inhibiting dynamin, a GTPase required for receptor-mediated endocytosis, phenocopies the effects of nickel and zinc, suggesting that dynamin-mediated endocytosis is required as a sink to limit the range of Nodal signaling. PMID:21337468

  20. An Adviser Agent for Mediator Training

    NASA Astrophysics Data System (ADS)

    Tanaka, Takahiro; Katagami, Daisuke; Nitta, Katsumi

    This paper describes an agent that shows advices for supporting mediator on our online mediation support system. The purpose of the advice is an education of mediator, and the agent presents it instead of the teacher. In this research, at first, we defined a mediation model that is an argumentation model between 3 people. Then, we defined some advice models based on the mediation model. The advice models create advice elements. The adviser agent monitors the mediation, gathers advice elements referring to advice models, and creates advice from elements according to the mediation scene. As a result, it becomes possible that is advising instead of the teacher according to the situation, education purpose and learner's level. We inspected the effectiveness of the advice by the experiment of moot mediation.

  1. Methods for Mediation Analysis with Missing Data

    ERIC Educational Resources Information Center

    Zhang, Zhiyong; Wang, Lijuan

    2013-01-01

    Despite wide applications of both mediation models and missing data techniques, formal discussion of mediation analysis with missing data is still rare. We introduce and compare four approaches to dealing with missing data in mediation analysis including list wise deletion, pairwise deletion, multiple imputation (MI), and a two-stage maximum…

  2. Axino dark matter in mirage mediation

    SciTech Connect

    Nakamura, Shuntaro; Okumura, Ken-ichi; Yamaguchi, Masahiro

    2009-04-17

    The mirage mediation of supersymmetry breaking is a phenomenologically quite interesting possibility, however, it suffers from two major problems: the moduli-induced gravitino problem and the {mu}-B{mu} problem. In this paper, we propose that the axionic extension of mirage mediation, axionic mirage mediation can solve both problems simultaneously. We address the cosmological consequences of the scenario extensively.

  3. Special Education Mediation: A Guide for Parents.

    ERIC Educational Resources Information Center

    Consortium for Appropriate Dispute Resolution in Special Education (CADRE), Eugene, OR.

    Designed for parents of students with disabilities living in Oregon, this brochure describes the general mediation process that parents can use to resolve special education services disputes with schools. It begins by discussing what mediation is and the characteristics of a trained mediator. It addresses the requirement for making mediation…

  4. 7 CFR 205.663 - Mediation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM Administrative Compliance § 205.663 Mediation. Any dispute with respect... a qualified mediator mutually agreed upon by the parties to the mediation. If a State...

  5. Causal Mediation Analysis: Warning! Assumptions Ahead

    ERIC Educational Resources Information Center

    Keele, Luke

    2015-01-01

    In policy evaluations, interest may focus on why a particular treatment works. One tool for understanding why treatments work is causal mediation analysis. In this essay, I focus on the assumptions needed to estimate mediation effects. I show that there is no "gold standard" method for the identification of causal mediation effects. In…

  6. Single-Level and Multilevel Mediation Analysis

    ERIC Educational Resources Information Center

    Tofighi, Davood; Thoemmes, Felix

    2014-01-01

    Mediation analysis is a statistical approach used to examine how the effect of an independent variable on an outcome is transmitted through an intervening variable (mediator). In this article, we provide a gentle introduction to single-level and multilevel mediation analyses. Using single-level data, we demonstrate an application of structural…

  7. 41 CFR 101-8.717 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Mediation. 101-8.717... FINANCIAL ASSISTANCE 8.7-Discrimination Prohibited on the Basis of Age § 101-8.717 Mediation. (a) GSA promptly refers to the mediation agency designated by the Secretary, HHS, all sufficient complaints...

  8. 7 CFR 400.94 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Mediation. 400.94 Section 400.94 Agriculture... AGRICULTURE GENERAL ADMINISTRATIVE REGULATIONS Appeal Procedure § 400.94 Mediation. For adverse decisions only: (a) Appellants have the right to seek mediation or other forms of alternative dispute resolution...

  9. 45 CFR 617.10 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Mediation. 617.10 Section 617.10 Public Welfare... OF AGE IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE FROM NSF § 617.10 Mediation. (a) NSF will refer to the Federal Mediation and Conciliation Service all complaints that fall...

  10. 7 CFR 900.109 - Mediation agreement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Mediation agreement. 900.109 Section 900.109 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... Mediation agreement. An agreement arrived at by mediation shall not become effective until approved by...

  11. 13 CFR 117.12 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Mediation. 117.12 Section 117.12... Mediation. (a) SBA shall, after ensuring that the complaint falls within the coverage of this Act and all... clearly within an exception, promptly refer the complaint to the Federal Mediation and...

  12. 34 CFR 300.506 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Mediation. 300.506 Section 300.506 Education... DISABILITIES Procedural Safeguards Due Process Procedures for Parents and Children § 300.506 Mediation. (a... due process complaint, to resolve disputes through a mediation process. (b) Requirements....

  13. Vernalization-mediated chromatin changes.

    PubMed

    Zografos, Brett R; Sung, Sibum

    2012-07-01

    Proper flowering time is vital for reproductive fitness in flowering plants. In Arabidopsis, vernalization is mediated primarily through the repression of a MADS box transcription factor, FLOWERING LOCUS C (FLC). The induction of a plant homeodomain-containing protein, VERNALIZATION INSENSITIVE 3 (VIN3), by vernalizing cold is required for proper repression of FLC. One of a myriad of changes that occurs after VIN3 is induced is the establishment of FLC chromatin at a mitotically repressed state due to the enrichment of repressive histone modifications. VIN3 induction by cold is the earliest known event during the vernalization response and includes changes in histone modifications at its chromatin. Here, the current understanding of the vernalization-mediated chromatin changes in Arabidopsis is discussed, with a focus on the roles of shared chromatin-modifying machineries in regulating VIN3 and FLC gene family expression during the course of vernalization.

  14. General gauge mediation and deconstruction

    NASA Astrophysics Data System (ADS)

    McGarrie, Moritz

    2010-11-01

    We locate a supersymmetry breaking hidden sector and supersymmetric standard model on different lattice points of an orbifold moose. The hidden sector is encoded in a set of current correlators and the effects of the current correlators are mediated by the lattice site gauge groups with "lattice hopping" functions and through the bifundamental matter that links the lattice sites together. We show how the gaugino mass, scalar mass and Casimir energy of the lattice can be computed for a general set of current correlators and then give specific formulas when the hidden sector is specified to be a generalised messenger sector. The results reproduce the effect of five dimensional gauge mediation from a purely four dimensional construction.

  15. Sequestered gravity in gauge mediation

    NASA Astrophysics Data System (ADS)

    Antoniadis, Ignatios; Benakli, Karim; Quiros, Mariano

    2016-07-01

    We present a novel mechanism of supersymmetry breaking embeddable in string theory and simultaneously sharing the main advantages of (sequestered) gravity and gauge mediation. It is driven by a Scherk-Schwarz deformation along a compact extra dimension, transverse to a brane stack supporting the supersymmetric extension of the Standard Model. This fixes the magnitude of the gravitino mass, together with that of the gauginos of a bulk gauge group, at a scale as high as 10^{10} GeV. Supersymmetry breaking is mediated to the observable sector dominantly by gauge interactions using massive messengers transforming non-trivially under the bulk and Standard Model gauge groups and leading to a neutralino LSP as dark matter candidate. The Higgsino mass μ and soft Higgs-bilinear B_μ term could be generated at the same order of magnitude as the other soft terms by effective supergravity couplings as in the Giudice-Masiero mechanism.

  16. RNA-mediated gene activation

    PubMed Central

    Jiao, Alan L; Slack, Frank J

    2014-01-01

    The regulation of gene expression by non-coding RNAs (ncRNAs) has become a new paradigm in biology. RNA-mediated gene silencing pathways have been studied extensively, revealing diverse epigenetic and posttranscriptional mechanisms. In contrast, the roles of ncRNAs in activating gene expression remains poorly understood. In this review, we summarize the current knowledge of gene activation by small RNAs, long non-coding RNAs, and enhancer-derived RNAs, with an emphasis on epigenetic mechanisms. PMID:24185374

  17. Plasmid-mediated quinolone resistance

    PubMed Central

    Jacoby, George A.; Strahilevitz, Jacob; Hooper, David C.

    2014-01-01

    Summary Three mechanisms for plasmid-mediated quinolone resistance (PMQR) have been discovered since 1998. Plasmid genes qnrA, qnrB, qnrC, qnrD, qnrS, and qnrVC code for proteins of the pentapeptide repeat family that protects DNA gyrase and topoisomerase IV from quinolone inhibition. The qnr genes appear to have been acquired from chromosomal genes in aquatic bacteria, are usually associated with mobilizing or transposable elements on plasmids, and are often incorporated into sul1-type integrons. The second plasmid-mediated mechanism involves acetylation of quinolones with an appropriate amino nitrogen target by a variant of the common aminoglycoside acetyltransferase AAC(6′)-Ib. The third mechanism is enhanced efflux produced by plasmid genes for pumps QepAB and OqxAB. PMQR has been found in clinical and environmental isolates around the world and appears to be spreading. The plasmid-mediated mechanisms provide only low-level resistance that by itself does not exceed the clinical breakpoint for susceptibility but nonetheless facilitates selection of higher-level resistance and makes infection by pathogens containing PMQR harder to treat. PMID:25584197

  18. Astrocyte-mediated ischemic tolerance.

    PubMed

    Hirayama, Yuri; Ikeda-Matsuo, Yuri; Notomi, Shoji; Enaida, Hiroshi; Kinouchi, Hiroyuki; Koizumi, Schuichi

    2015-03-01

    Preconditioning (PC) using a preceding sublethal ischemic insult is an attractive strategy for protecting neurons by inducing ischemic tolerance in the brain. Although the underlying molecular mechanisms have been extensively studied, almost all studies have focused on neurons. Here, using a middle cerebral artery occlusion model in mice, we show that astrocytes play an essential role in the induction of brain ischemic tolerance. PC caused activation of glial cells without producing any noticeable brain damage. The spatiotemporal pattern of astrocytic, but not microglial, activation correlated well with that of ischemic tolerance. Interestingly, such activation in astrocytes lasted at least 8 weeks. Importantly, inhibiting astrocytes with fluorocitrate abolished the induction of ischemic tolerance. To investigate the underlying mechanisms, we focused on the P2X7 receptor as a key molecule in astrocyte-mediated ischemic tolerance. P2X7 receptors were dramatically upregulated in activated astrocytes. PC-induced ischemic tolerance was abolished in P2X7 receptor knock-out mice. Moreover, our results suggest that hypoxia-inducible factor-1α, a well known mediator of ischemic tolerance, is involved in P2X7 receptor-mediated ischemic tolerance. Unlike previous reports focusing on neuron-based mechanisms, our results show that astrocytes play indispensable roles in inducing ischemic tolerance, and that upregulation of P2X7 receptors in astrocytes is essential. PMID:25740510

  19. Male-mediated developmental toxicity.

    PubMed

    Anderson, Diana; Schmid, Thomas E; Baumgartner, Adolf

    2014-01-01

    Male-mediated developmental toxicity has been of concern for many years. The public became aware of male-mediated developmental toxicity in the early 1990s when it was reported that men working at Sellafield might be causing leukemia in their children. Human and animal studies have contributed to our current understanding of male-mediated effects. Animal studies in the 1980s and 1990s suggested that genetic damage after radiation and chemical exposure might be transmitted to offspring. With the increasing understanding that there is histone retention and modification, protamine incorporation into the chromatin and DNA methylation in mature sperm and that spermatozoal RNA transcripts can play important roles in the epigenetic state of sperm, heritable studies began to be viewed differently. Recent reports using molecular approaches have demonstrated that DNA damage can be transmitted to babies from smoking fathers, and expanded simple tandem repeats minisatellite mutations were found in the germline of fathers who were exposed to radiation from the Chernobyl nuclear power plant disaster. In epidemiological studies, it is possible to clarify whether damage is transmitted to the sons after exposure of the fathers. Paternally transmitted damage to the offspring is now recognized as a complex issue with genetic as well as epigenetic components. PMID:24369136

  20. Substrate Mediated Enzyme Prodrug Therapy

    PubMed Central

    Fejerskov, Betina; Zelikin, Alexander N.

    2012-01-01

    In this report, we detail Substrate Mediated Enzyme Prodrug Therapy (SMEPT) as a novel approach in drug delivery which relies on enzyme-functionalized cell culture substrates to achieve a localized conversion of benign prodrug(s) into active therapeutics with subsequent delivery to adhering cells or adjacent tissues. For proof-of-concept SMEPT, we use surface adhered micro-structured physical hydrogels based on poly(vinyl alcohol), β-glucuronidase enzyme and glucuronide prodrugs. We demonstrate enzymatic activity mediated by the assembled hydrogel samples and illustrate arms of control over rate of release of model fluorescent cargo. SMEPT was not impaired by adhering cells and afforded facile time - and dose – dependent uptake of the in situ generated fluorescent cargo by hepatic cells, HepG2. With the use of a glucuronide derivative of an anticancer drug, SN-38, SMEPT afforded a decrease in cell viability to a level similar to that achieved using parent drug. Finally, dose response was achieved using SMEPT and administration of judiciously chosen concentration of SN-38 glucuronide prodrug thus revealing external control over drug delivery using drug eluting surface. We believe that this highly adaptable concept will find use in diverse biomedical applications, specifically surface mediated drug delivery and tissue engineering. PMID:23152927

  1. Male-mediated developmental toxicity

    PubMed Central

    Anderson, Diana; Schmid, Thomas E; Baumgartner, Adolf

    2014-01-01

    Male-mediated developmental toxicity has been of concern for many years. The public became aware of male-mediated developmental toxicity in the early 1990s when it was reported that men working at Sellafield might be causing leukemia in their children. Human and animal studies have contributed to our current understanding of male-mediated effects. Animal studies in the 1980s and 1990s suggested that genetic damage after radiation and chemical exposure might be transmitted to offspring. With the increasing understanding that there is histone retention and modification, protamine incorporation into the chromatin and DNA methylation in mature sperm and that spermatozoal RNA transcripts can play important roles in the epigenetic state of sperm, heritable studies began to be viewed differently. Recent reports using molecular approaches have demonstrated that DNA damage can be transmitted to babies from smoking fathers, and expanded simple tandem repeats minisatellite mutations were found in the germline of fathers who were exposed to radiation from the Chernobyl nuclear power plant disaster. In epidemiological studies, it is possible to clarify whether damage is transmitted to the sons after exposure of the fathers. Paternally transmitted damage to the offspring is now recognized as a complex issue with genetic as well as epigenetic components. PMID:24369136

  2. Mediators and Metaphorical Analysis: A Phenomenological Study of Florida Family Court Mediators

    ERIC Educational Resources Information Center

    Storrow, Rebecca A.

    2012-01-01

    Florida family court mediation programs have typically been assessed with quantitative analysis. To understand the complexity of the experience of being a family mediator, it was necessary to explore how mediators practiced through qualitative research. Metaphors have been considered to be representations of mediators' mental models regarding…

  3. Hydrological models are mediating models

    NASA Astrophysics Data System (ADS)

    Babel, L. V.; Karssenberg, D.

    2013-08-01

    Despite the increasing role of models in hydrological research and decision-making processes, only few accounts of the nature and function of models exist in hydrology. Earlier considerations have traditionally been conducted while making a clear distinction between physically-based and conceptual models. A new philosophical account, primarily based on the fields of physics and economics, transcends classes of models and scientific disciplines by considering models as "mediators" between theory and observations. The core of this approach lies in identifying models as (1) being only partially dependent on theory and observations, (2) integrating non-deductive elements in their construction, and (3) carrying the role of instruments of scientific enquiry about both theory and the world. The applicability of this approach to hydrology is evaluated in the present article. Three widely used hydrological models, each showing a different degree of apparent physicality, are confronted to the main characteristics of the "mediating models" concept. We argue that irrespective of their kind, hydrological models depend on both theory and observations, rather than merely on one of these two domains. Their construction is additionally involving a large number of miscellaneous, external ingredients, such as past experiences, model objectives, knowledge and preferences of the modeller, as well as hardware and software resources. We show that hydrological models convey the role of instruments in scientific practice by mediating between theory and the world. It results from these considerations that the traditional distinction between physically-based and conceptual models is necessarily too simplistic and refers at best to the stage at which theory and observations are steering model construction. The large variety of ingredients involved in model construction would deserve closer attention, for being rarely explicitly presented in peer-reviewed literature. We believe that devoting

  4. The evolution of inflammatory mediators

    PubMed Central

    Rowley, Andrew F.

    1996-01-01

    Invertebrates do not display the level of sophistication in immune reactivity characteristic of mammals and other ‘higher’ vertebrates. Their great number and diversity of forms, however, reflect their evolutionary success and hence they must have effective mechanisms of defence to deal with parasites and pathogens and altered self tissues. Inflammation appears to be an important first line defence in all invertebrates and vertebrates. This brief review deals with the inflammatory responses of invertebrates and fish concentrating on the cell types involved and the mediators of inflammation, in particular, eicosanoids, cytokines and adhesion molecules. PMID:18475690

  5. Mediation designs for tobacco prevention research

    PubMed Central

    MacKinnon, David P.; Taborga, Marcia P.; Morgan-Lopez, Antonio A.

    2010-01-01

    This paper describes research designs and statistical analyses to investigate how tobacco prevention programs achieve their effects on tobacco use. A theoretical approach to program development and evaluation useful for any prevention program guides the analysis. The theoretical approach focuses on action theory for how the program affects mediating variables and on conceptual theory for how mediating variables are related to tobacco use. Information on the mediating mechanisms by which tobacco prevention programs achieve effects is useful for the development of efficient programs and provides a test of the theoretical basis of prevention efforts. Examples of these potential mediating mechanisms are described including mediated effects through attitudes, social norms, beliefs about positive consequences, and accessibility to tobacco. Prior research provides evidence that changes in social norms are a critical mediating mechanism for successful tobacco prevention. Analysis of mediating variables in single group designs with multiple mediators are described as well as multiple group randomized designs which are the most likely to accurately uncover important mediating mechanisms. More complicated dismantling and constructive designs are described and illustrated based on current findings from tobacco research. Mediation analysis for categorical outcomes and more complicated statistical methods are outlined. PMID:12324176

  6. The Mediator complex and transcription regulation

    PubMed Central

    Poss, Zachary C.; Ebmeier, Christopher C.

    2013-01-01

    The Mediator complex is a multi-subunit assembly that appears to be required for regulating expression of most RNA polymerase II (pol II) transcripts, which include protein-coding and most non-coding RNA genes. Mediator and pol II function within the pre-initiation complex (PIC), which consists of Mediator, pol II, TFIIA, TFIIB, TFIID, TFIIE, TFIIF and TFIIH and is approximately 4.0 MDa in size. Mediator serves as a central scaffold within the PIC and helps regulate pol II activity in ways that remain poorly understood. Mediator is also generally targeted by sequence-specific, DNA-binding transcription factors (TFs) that work to control gene expression programs in response to developmental or environmental cues. At a basic level, Mediator functions by relaying signals from TFs directly to the pol II enzyme, thereby facilitating TF-dependent regulation of gene expression. Thus, Mediator is essential for converting biological inputs (communicated by TFs) to physiological responses (via changes in gene expression). In this review, we summarize an expansive body of research on the Mediator complex, with an emphasis on yeast and mammalian complexes. We focus on the basics that underlie Mediator function, such as its structure and subunit composition, and describe its broad regulatory influence on gene expression, ranging from chromatin architecture to transcription initiation and elongation, to mRNA processing. We also describe factors that influence Mediator structure and activity, including TFs, non-coding RNAs and the CDK8 module. PMID:24088064

  7. Transporter-mediated biofuel secretion.

    PubMed

    Doshi, Rupak; Nguyen, Tuan; Chang, Geoffrey

    2013-05-01

    Engineering microorganisms to produce biofuels is currently among the most promising strategies in renewable energy. However, harvesting these organisms for extracting biofuels is energy- and cost-intensive, limiting the commercial feasibility of large-scale production. Here, we demonstrate the use of a class of transport proteins of pharmacological interest to circumvent the need to harvest biomass during biofuel production. We show that membrane-embedded transporters, better known to efflux lipids and drugs, can be used to mediate the secretion of intracellularly synthesized model isoprenoid biofuel compounds to the extracellular milieu. Transporter-mediated biofuel secretion sustainably maintained an approximate three- to fivefold boost in biofuel production in our Escherichia coli test system. Because the transporters used in this study belong to the ubiquitous ATP-binding cassette protein family, we propose their use as "plug-and-play" biofuel-secreting systems in a variety of bacteria, cyanobacteria, diatoms, yeast, and algae used for biofuel production. This investigation showcases the potential of expressing desired membrane transport proteins in cell factories to achieve the export or import of substances of economic, environmental, or therapeutic importance.

  8. Lipid mediators in diabetic nephropathy

    PubMed Central

    2014-01-01

    The implications of lipid lowering drugs in the treatment of diabetic nephropathy have been considered. At the same time, the clinical efficacy of lipid lowering drugs has resulted in improvement in the cardiovascular functions of chronic kidney disease (CKD) patients with or without diabetes, but no remarkable improvement has been observed in the kidney outcome. Earlier lipid mediators have been shown to cause accumulative effects in diabetic nephropathy (DN). Here, we attempt to analyze the involvement of lipid mediators in DN. The hyperglycemia-induced overproduction of diacyglycerol (DAG) is one of the causes for the activation of protein kinase C (PKCs), which is responsible for the activation of pathways, including the production of VEGF, TGFβ1, PAI-1, NADPH oxidases, and NFҟB signaling, accelerating the development of DN. Additionally, current studies on the role of ceramide are one of the major fields of study in DN. Researchers have reported excessive ceramide formation in the pathobiological conditions of DN. There is less report on the effect of lipid lowering drugs on the reduction of PKC activation and ceramide synthesis. Regulating PKC activation and ceramide biosynthesis could be a protective measure in the therapeutic potential of DN. Lipid lowering drugs also upregulate anti-fibrotic microRNAs, which could hint at the effects of lipid lowering drugs in DN. PMID:25206927

  9. Detergent-mediated protein aggregation.

    PubMed

    Neale, Chris; Ghanei, Hamed; Holyoake, John; Bishop, Russell E; Privé, Gilbert G; Pomès, Régis

    2013-04-01

    Because detergents are commonly used to solvate membrane proteins for structural evaluation, much attention has been devoted to assessing the conformational bias imparted by detergent micelles in comparison to the native environment of the lipid bilayer. Here, we conduct six 500-ns simulations of a system with >600,000 atoms to investigate the spontaneous self assembly of dodecylphosphocholine detergent around multiple molecules of the integral membrane protein PagP. This detergent formed equatorial micelles in which acyl chains surround the protein's hydrophobic belt, confirming existing models of the detergent solvation of membrane proteins. In addition, unexpectedly, the extracellular and periplasmic apical surfaces of PagP interacted with the headgroups of detergents in other micelles 85 and 60% of the time, respectively, forming complexes that were stable for hundreds of nanoseconds. In some cases, an apical surface of one molecule of PagP interacted with an equatorial micelle surrounding another molecule of PagP. In other cases, the apical surfaces of two molecules of PagP simultaneously bound a neat detergent micelle. In these ways, detergents mediated the non-specific aggregation of folded PagP. These simulation results are consistent with dynamic light scattering experiments, which show that, at detergent concentrations ≥600 mM, PagP induces the formation of large scattering species that are likely to contain many copies of the PagP protein. Together, these simulation and experimental results point to a potentially generic mechanism of detergent-mediated protein aggregation.

  10. Cell-Mediated Drugs Delivery

    PubMed Central

    Batrakova, Elena V.; Gendelman, Howard E.; Kabanov, Alexander V.

    2011-01-01

    INTRODUCTION Drug targeting to sites of tissue injury, tumor or infection with limited toxicity is the goal for successful pharmaceutics. Immunocytes (including mononuclear phagocytes (dendritic cells, monocytes and macrophages), neutrophils, and lymphocytes) are highly mobile; they can migrate across impermeable barriers and release their drug cargo at sites of infection or tissue injury. Thus immune cells can be exploited as trojan horses for drug delivery. AREAS COVERED IN THIS REVIEW This paper reviews how immunocytes laden with drugs can cross the blood brain or blood tumor barriers, to facilitate treatments for infectious diseases, injury, cancer, or inflammatory diseases. The promises and perils of cell-mediated drug delivery are reviewed, with examples of how immunocytes can be harnessed to improve therapeutic end points. EXPERT OPINION Using cells as delivery vehicles enables targeted drug transport, and prolonged circulation times, along with reductions in cell and tissue toxicities. Such systems for drug carriage and targeted release represent a novel disease combating strategy being applied to a spectrum of human disorders. The design of nanocarriers for cell-mediated drug delivery may differ from those used for conventional drug delivery systems; nevertheless, engaging different defense mechanisms into drug delivery may open new perspectives for the active delivery of drugs. PMID:21348773

  11. Transporter-mediated biofuel secretion.

    PubMed

    Doshi, Rupak; Nguyen, Tuan; Chang, Geoffrey

    2013-05-01

    Engineering microorganisms to produce biofuels is currently among the most promising strategies in renewable energy. However, harvesting these organisms for extracting biofuels is energy- and cost-intensive, limiting the commercial feasibility of large-scale production. Here, we demonstrate the use of a class of transport proteins of pharmacological interest to circumvent the need to harvest biomass during biofuel production. We show that membrane-embedded transporters, better known to efflux lipids and drugs, can be used to mediate the secretion of intracellularly synthesized model isoprenoid biofuel compounds to the extracellular milieu. Transporter-mediated biofuel secretion sustainably maintained an approximate three- to fivefold boost in biofuel production in our Escherichia coli test system. Because the transporters used in this study belong to the ubiquitous ATP-binding cassette protein family, we propose their use as "plug-and-play" biofuel-secreting systems in a variety of bacteria, cyanobacteria, diatoms, yeast, and algae used for biofuel production. This investigation showcases the potential of expressing desired membrane transport proteins in cell factories to achieve the export or import of substances of economic, environmental, or therapeutic importance. PMID:23613592

  12. Deuterosome-mediated centriole biogenesis.

    PubMed

    Klos Dehring, Deborah A; Vladar, Eszter K; Werner, Michael E; Mitchell, Jennifer W; Hwang, Peter; Mitchell, Brian J

    2013-10-14

    The ability of cells to faithfully duplicate their two centrioles once per cell cycle is critical for proper mitotic progression and chromosome segregation. Multiciliated cells represent an interesting variation of centriole duplication in that these cells generate greater than 100 centrioles, which form the basal bodies of their motile cilia. This centriole amplification is proposed to require a structure termed the deuterosome, thought to be capable of promoting de novo centriole biogenesis. Here, we begin to molecularly characterize the deuterosome and identify it as a site for the localization of Cep152, Plk4, and SAS6. Additionally we identify CCDC78 as a centriole-associated and deuterosome protein that is essential for centriole amplification. Overexpression of Cep152, but not Plk4, SAS6, or CCDC78, drives overamplification of centrioles. However, in CCDC78 morphants, Cep152 fails to localize to the deuterosome and centriole biogenesis is impaired, indicating that CCDC78-mediated recruitment of Cep152 is required for deuterosome-mediated centriole biogenesis.

  13. Dynamics of Phosphoinositide-Dependent Signaling in Sympathetic Neurons

    PubMed Central

    Kruse, Martin; Vivas, Oscar; Traynor-Kaplan, Alexis

    2016-01-01

    In neurons, loss of plasma membrane phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] leads to a decrease in exocytosis and changes in electrical excitability. Restoration of PI(4,5)P2 levels after phospholipase C activation is therefore essential for a return to basal neuronal activity. However, the dynamics of phosphoinositide metabolism have not been analyzed in neurons. We measured dynamic changes of PI(4,5)P2, phosphatidylinositol 4-phosphate, diacylglycerol, inositol 1,4,5-trisphosphate, and Ca2+ upon muscarinic stimulation in sympathetic neurons from adult male Sprague-Dawley rats with electrophysiological and optical approaches. We used this kinetic information to develop a quantitative description of neuronal phosphoinositide metabolism. The measurements and analysis show and explain faster synthesis of PI(4,5)P2 in sympathetic neurons than in electrically nonexcitable tsA201 cells. They can be used to understand dynamic effects of receptor-mediated phospholipase C activation on excitability and other PI(4,5)P2-dependent processes in neurons. SIGNIFICANCE STATEMENT Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] is a minor phospholipid in the cytoplasmic leaflet of the plasma membrane. Depletion of PI(4,5)P2 via phospholipase C-mediated hydrolysis leads to a decrease in exocytosis and alters electrical excitability in neurons. Restoration of PI(4,5)P2 is essential for a return to basal neuronal activity. However, the dynamics of phosphoinositide metabolism have not been analyzed in neurons. We studied the dynamics of phosphoinositide metabolism in sympathetic neurons upon muscarinic stimulation and used the kinetic information to develop a quantitative description of neuronal phosphoinositide metabolism. The measurements and analysis show a several-fold faster synthesis of PI(4,5)P2 in sympathetic neurons than in an electrically nonexcitable cell line, and provide a framework for future studies of PI(4,5)P2-dependent processes in neurons. PMID:26818524

  14. Sustained diacylglycerol formation from inositol phospholipids in angiotensin II-stimulated vascular smooth muscle cells

    SciTech Connect

    Griendling, K.K.; Rittenhouse, S.E.; Brock, T.A.; Ekstein, L.S.; Gimbrone, M.A. Jr.; Alexander, R.W.

    1986-05-05

    Angiotensin II acts on cultured rat aortic vascular smooth muscle cells to stimulate phospholipase C-mediated hydrolysis of membrane phosphoinositides and subsequent formation of diacylglycerol and inositol phosphates. In intact cells, angiotensin II induces a dose-dependent increase in diglyceride which is detectable after 5 s and sustained for at least 20 min. Angiotensin II (100 nM)-stimulated diglyceride formation is biphasic, peaking at 15 s (227 +/- 19% control) and at 5 min (303 +/- 23% control). Simultaneous analysis of labeled inositol phospholipids shows that at 15 s phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 4-phosphate (PIP) decline to 52 +/- 6% control and 63 +/- 5% control, respectively, while phosphatidylinositol (PI) remains unchanged. In contrast, at 5 min, PIP2 and PIP have returned toward control levels (92 +/- 2 and 82 +/- 4% control, respectively), while PI has decreased substantially (81 +/- 2% control). The calcium ionophore ionomycin (15 microM) stimulates diglyceride accumulation but does not cause PI hydrolysis. 4 beta-Phorbol 12-myristate 13-acetate, an activator of protein kinase C, inhibits early PIP and PIP2 breakdown and diglyceride formation, without inhibiting late-phase diglyceride accumulation. Thus, angiotensin II induces rapid transient breakdown of PIP and PIP2 and delayed hydrolysis of PI. The rapid attenuation of polyphosphoinositide breakdown is likely caused by a protein kinase C-mediated inhibition of PIP and PIP2 hydrolysis. While in vascular smooth muscle stimulated with angiotensin II inositol 1,4,5-trisphosphate formation is transient, diglyceride production is biphasic, suggesting that initial and sustained diglyceride formation from the phosphoinositides results from different biochemical and/or cellular processes.

  15. The future of intercultural mediation in Belgium.

    PubMed

    Nierkens, Vera; Krumeich, Anja; de Ridder, Ri; van Dongen, Martien

    2002-04-01

    Intercultural mediation was developed to solve problems between western (Belgian) health professionals and Turkish, Moroccan and Italian clients. The need for intercultural mediation in Belgium Health Care was measured by asking intercultural mediators to complete a questionnaire about situations in which language, culture, social-economic and personal circumstances cause difficulties. Results show that the profession 'intercultural mediator' continues to be important in improving the quality and accessibility of the Belgian health care for ethnic minorities. Even if clients speak Flemish fluently, there are still difficulties between health professional and client caused by culture, social-economic and personal circumstances. PMID:11932124

  16. 34 CFR 303.419 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION EARLY INTERVENTION PROGRAM FOR INFANTS AND TODDLERS WITH DISABILITIES Procedural Safeguards Mediation and Due Process Procedures for Parents and Children §...

  17. Protein-mediated enamel mineralization.

    PubMed

    Moradian-Oldak, Janet

    2012-06-01

    Enamel is a hard nanocomposite bioceramic with significant resilience that protects the mammalian tooth from external physical and chemical damages. The remarkable mechanical properties of enamel are associated with its hierarchical structural organization and its thorough connection with underlying dentin. This dynamic mineralizing system offers scientists a wealth of information that allows the study of basic principels of organic matrix-mediated biomineralization and can potentially be utilized in the fields of material science and engineering for development and design of biomimetic materials. This chapter will provide a brief overview of enamel hierarchical structure and properties and the process and stages of amelogenesis. Particular emphasis is given to current knowledge of extracellular matrix protein and proteinases, and the structural chemistry of the matrix components and their putative functions. The chapter will conclude by discussing the potential of enamel for regrowth.

  18. Lepton-mediated electroweak baryogenesis

    SciTech Connect

    Chung, Daniel J. H.; Garbrecht, Bjorn; Ramsey-Musolf, Michael J.; Tulin, Sean

    2010-03-15

    We investigate the impact of the tau and bottom Yukawa couplings on the transport dynamics for electroweak baryogenesis in supersymmetric extensions of the standard model. Although it has generally been assumed in the literature that all Yukawa interactions except those involving the top quark are negligible, we find that the tau and bottom Yukawa interaction rates are too fast to be neglected. We identify an illustrative 'lepton-mediated electroweak baryogenesis' scenario in which the baryon asymmetry is induced mainly through the presence of a left-handed leptonic charge. We derive analytic formulas for the computation of the baryon asymmetry that, in light of these effects, are qualitatively different from those in the established literature. In this scenario, for fixed CP-violating phases, the baryon asymmetry has opposite sign compared to that calculated using established formulas.

  19. Protooncogenes as mediators of apoptosis.

    PubMed

    Teng, C S

    2000-01-01

    Apoptosis has been well established as a vital biological phenomenon that is important in the maintenance of cellular homeostasis. Three major protooncogene families and their encoded proteins function as mediators of apoptosis in various cell types and are the subject of this chapter. Protooncogenic proteins such as c-Myc/Max, c-Fos/c-Jun, and Bcl-2/Bax utilize a synergetic effect to enhance their roles in the pro- or antiapoptotic action. These family members activate and repress the expression of their target genes, control cell cycle progression, and execute programmed cell death. Repression or overproduction of these protooncogenic proteins induces apoptosis, which may vary as a result of either cell type specificity or the nature of the apoptotic stimuli. The proapoptotic and antiapoptotic proteins exert their effects in the membrane of cellular organelles. Here they generate cell-type-specific signals that activate the caspase family of proteases and their regulators for the execution of apoptosis.

  20. Nanoparticle-Mediated Gene Delivery

    NASA Astrophysics Data System (ADS)

    Jin, Sha; Leach, John C.; Ye, Kaiming

    Nonviral gene delivery has been gaining considerable attention recently. Although the efficacy of DNA transfection, which is a major concern, is low in nonviral vector-mediated gene transfer compared with viral ones, nonviral vectors are relatively easy to prepare, less immunogenic and oncogenic, and have no potential of virus recombination and no limitation on the size of a transferred gene. The ability to incorporate genetic materials such as plasmid DNA, RNA, and siRNA into functionalized nanoparticles with little toxicity demonstrates a new era in pharmacotherapy for delivering genes selectively to tissues and cells. In this chapter, we highlight the basic concepts and applications of nonviral gene delivery using super paramagnetic iron oxide nanoparticles and functionalized silica nanoparticles. The experimental protocols related to these topics are described in the chapter.

  1. Mediated electrochemical hazardous waste destruction

    SciTech Connect

    Hickman, R.G.; Farmer, J.C.; Wang, F.T.

    1991-08-01

    There are few permitted processes for mixed waste (radioactive plus chemically hazardous) treatment. We are developing electrochemical processes that convert the toxic organic components of mixed waste to water, carbon dioxide, an innocuous anions such as chloride. Aggressive oxidizer ions such as Ag{sup 2+} or Ce{sup +4} are produced at an anode. These can attack the organic molecules directly. They can also attack water which yields hydroxyl free radicals that in turn attack the organic molecules. The condensed (i.e., solid and/or liquid) effluent streams contain the inorganic radionuclide forms. These may be treated with existing technology and prepared for final disposal. Kinetics and the extent of destruction of some toxic organics have been measured. Depending on how the process is operated, coulombic efficiency can be nearly 100%. In addition, hazardous organic materials are becoming very expensive to dispose of and when they are combined with transuranic radioactive elements no processes are presently permitted. Mediated electrochemical oxidation is an ambient-temperature aqueous-phase process that can be used to oxidize organic components of mixed wastes. Problems associated with incineration, such as high-temperature volatilization of radionuclides, are avoided. Historically, Ag (2) has been used as a mediator in this process. Fe(6) and Co(3) are attractive alternatives to Ag(2) since they form soluble chlorides during the destruction of chlorinated solvents. Furthermore, silver itself is a toxic heavy metal. Quantitative data has been obtained for the complete oxidation of ethylene glycol by Fe(6) and Co(3). Though ethylene glycol is a nonhalogenated organic, this data has enabled us to make direct comparisons of activities of Fe(6) and Co(3) with Ag(2). Very good quantitative data for the oxidation of ethylene glycol by Ag(2) had already been collected. 4 refs., 6 figs.

  2. Detergent-mediated protein aggregation

    PubMed Central

    Neale, Chris; Ghanei, Hamed; Holyoake, John; Bishop, Russell E.; Privé, Gilbert G.; Pomès, Régis

    2016-01-01

    Because detergents are commonly used to solvate membrane proteins for structural evaluation, much attention has been devoted to assessing the conformational bias imparted by detergent micelles in comparison to the native environment of the lipid bilayer. Here, we conduct six 500-ns simulations of a system with >600,000 atoms to investigate the spontaneous self assembly of dodecylphosphocholine detergent around multiple molecules of the integral membrane protein PagP. This detergent formed equatorial micelles in which acyl chains surround the protein’s hydrophobic belt, confirming existing models of the detergent solvation of membrane proteins. In addition, unexpectedly, the extracellular and periplasmic apical surfaces of PagP interacted with the headgroups of detergents in other micelles 85 and 60% of the time, respectively, forming complexes that were stable for hundreds of nanoseconds. In some cases, an apical surface of one molecule of PagP interacted with an equatorial micelle surrounding another molecule of PagP. In other cases, the apical surfaces of two molecules of PagP simultaneously bound a neat detergent micelle. In these ways, detergents mediated the non-specific aggregation of folded PagP. These simulation results are consistent with dynamic light scattering experiments, which show that, at detergent concentrations ≥600 mM, PagP induces the formation of large scattering species that are likely to contain many copies of the PagP protein. Together, these simulation and experimental results point to a potentially generic mechanism of detergent-mediated protein aggregation. PMID:23466535

  3. RNA mediated assembly of nanostructures

    NASA Astrophysics Data System (ADS)

    Rouge, Jessica Lynn

    The first chapter of this work presents a comprehensive look at RNA mediated nanoparticle formation. The overall goal of this research is to gain a deeper understanding of the RNA-particle formation mechanism and the basic properties of the materials selected by modified RNA molecules. Understanding such RNA-substrate interactions and how they translate into the physical and chemical characteristics of the nanoparticles they create are important fundamental concepts when considering these biotemplated materials as potential chemical catalysts. The RNA sequences discussed in the first chapter (referred to as Pdases) were discovered using RNA in vitro selection techniques. These Pdases were found to be capable of forming inorganic palladium (Pd) containing nanoparticles with impressive control over an individual particle's size and shape, despite incubation with the same organometallic precursor. This discovery held exciting implications for inorganic nanoparticle design while also generating numerous questions regarding the mechanism of RNA mediated particle growth. The central question that arose after this initial discovery was how could a biomolecule be used to tailor the physical size and shape of inorganic materials? Starting with a chemical proof designed to uncover the composition of the nanoparticles formed by RNA mediation, this chapter investigates the basic material properties of the nanoparticles while also introducing surprising results regarding the effect of multiple sequences on nanoparticle growth outcomes. In the second chapter, the experiments shift to developing methods to investigate nanoparticle growth mechanisms by fluorescence spectroscopy. A fluorescence polarization anisotropy (FPA) assay is presented in which the strengths of the technique are adapted for studying the formation of RNA mediated Pd nanoparticles in real time. This is a unique application of FPA, as it has been adapted to encompass both the biochemical and materials analysis

  4. Grief Resolution of Birthmothers in Confidential, Time-Limited Mediated, Ongoing Mediated, and Fully Disclosed Adoptions.

    ERIC Educational Resources Information Center

    Christian, Cinda L.; McRoy, Ruth G.; Grotevant, Harold D.; Bryant, Chalandra M.

    1997-01-01

    Examined grief resolution issues for birthmothers who placed infants for adoption. Found that birthmothers in fully disclosed adoptions had better resolution than with confidential and time-limited mediated adoptions, and those in ongoing mediated had better resolution than with time-limited mediated adoptions. Findings pose implications for…

  5. Tests of Mediation: Paradoxical Decline in Statistical Power as a Function of Mediator Collinearity

    ERIC Educational Resources Information Center

    Beasley, T. Mark

    2014-01-01

    Increasing the correlation between the independent variable and the mediator ("a" coefficient) increases the effect size ("ab") for mediation analysis; however, increasing a by definition increases collinearity in mediation models. As a result, the standard error of product tests increase. The variance inflation caused by…

  6. Forms of Mediation: The Case of Interpreter-Mediated Interactions in Medical Systems

    ERIC Educational Resources Information Center

    Baraldi, Claudio

    2009-01-01

    This paper analyses the forms of mediation in interlinguistic interactions performed in Italian healthcare services and in contexts of migration. The literature encourages dialogic transformative mediation, empowering participants' voices and changing cultural presuppositions in social systems. It may be doubtful, however, whether mediation can…

  7. 7 CFR 614.11 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Mediation. 614.11 Section 614.11 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE CONSERVATION OPERATIONS NRCS APPEAL PROCEDURES § 614.11 Mediation. (a) A participant who wishes...

  8. 34 CFR 303.431 - Mediation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Mediation. 303.431 Section 303.431 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION EARLY INTERVENTION PROGRAM FOR INFANTS AND TODDLERS WITH DISABILITIES Procedural Safeguards Mediation...

  9. 45 CFR 617.10 - Mediation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 3 2014-10-01 2014-10-01 false Mediation. 617.10 Section 617.10 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION NONDISCRIMINATION ON THE BASIS... mediator shall prepare a written statement of the agreement and have the complainant and recipient sign...

  10. Families and Schools: Resolving Disputes through Mediation.

    ERIC Educational Resources Information Center

    Consortium for Appropriate Dispute Resolution in Special Education (CADRE), Eugene, OR.

    This publication attempts to answer common questions that parents, teachers, administrators, and others have about mediation as a means of resolving conflicts between parents of a child with a disability and the school district. Four real life stories are used to show how experienced mediators use a variety of methods to help participants work out…

  11. Parent Mediation Empowers Sibling Conflict Resolution

    ERIC Educational Resources Information Center

    Ross, Hildy S.; Lazinski, Marysia J.

    2014-01-01

    Research Findings: For the current study, formal mediation procedures were adapted for families and parents were trained and asked to mediate their children's disputes; control group parents intervened as they normally would. Conflict negotiations with parents and their children (ages 3½-11 years) occurring 3 and 7 weeks following training,…

  12. Que Es la Mediacion? (What Is Mediation?).

    ERIC Educational Resources Information Center

    Consortium for Appropriate Dispute Resolution in Special Education (CADRE), Eugene, OR.

    This brief paper, in Spanish, discusses the use of mediation as a method for resolving disagreements between schools or early intervention programs and parents of children with disabilities. It identifies benefits of mediation such as maintenance of an ongoing and positive relationship between the school and family, simple resolution of conflicts…

  13. 45 CFR 16.18 - Mediation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Mediation. 16.18 Section 16.18 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURES OF THE DEPARTMENTAL GRANT APPEALS BOARD § 16.18 Mediation. (a) In cases pending before the Board. If the Board decides that...

  14. 45 CFR 16.18 - Mediation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Mediation. 16.18 Section 16.18 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURES OF THE DEPARTMENTAL GRANT APPEALS BOARD § 16.18 Mediation. (a) In cases pending before the Board. If the Board decides that...

  15. 45 CFR 16.18 - Mediation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Mediation. 16.18 Section 16.18 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURES OF THE DEPARTMENTAL GRANT APPEALS BOARD § 16.18 Mediation. (a) In cases pending before the Board. If the Board decides that...

  16. The Mediator Role in Social Work Practice.

    ERIC Educational Resources Information Center

    Parsons, Ruth J.

    1991-01-01

    Notes that mediation as problem-solving intervention in social work became widely used in child custody and divorce cases, child-parent conflicts, and family disputes. Argues that mediator role is inherent in social work, and examines context for and assumptions underlying it. Discusses nature of conflicts, issue of neutrality within social work…

  17. Giftedness as a Function of Right Mediation.

    ERIC Educational Resources Information Center

    Rosemarin, Shoshana

    1999-01-01

    This article applies the concept of mediation to pupils who are or may be gifted as well as to motivational and psychological functions. It uses Feuerstein's theory of Mediated Learning Experience to analyze Renzulli's Enrichment Model for the gifted including underachieving and disabled gifted students and concludes that correct mediation…

  18. Mediation Training for Middle School Students.

    ERIC Educational Resources Information Center

    Conflict Resolution Unlimited, Inc., Bellevue, WA.

    Young people need help in learning how to use alternative dispute resolution skills at school. Methods for teaching these skills are presented in this manual. The training centers on the following major themes: The Mediation Process, Cultural Diversity, Communication Skills, Feelings, Mediation Techniques, Dealing with Difficult Situations, and…

  19. Elaborative Retrieval: Do Semantic Mediators Improve Memory?

    ERIC Educational Resources Information Center

    Lehman, Melissa; Karpicke, Jeffrey D.

    2016-01-01

    The elaborative retrieval account of retrieval-based learning proposes that retrieval enhances retention because the retrieval process produces the generation of semantic mediators that link cues to target information. We tested 2 assumptions that form the basis of this account: that semantic mediators are more likely to be generated during…

  20. 7 CFR 400.94 - Mediation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...: (a) Appellants have the right to seek mediation or other forms of alternative dispute resolution in... without resolution. If a new adverse decision that raises new matters or relies on different grounds is... in certified States that are not currently offering mediation on the subject in dispute. An...

  1. Verbal Mediation and Satiation in Young Children.

    ERIC Educational Resources Information Center

    Cook, Harold; Smothergill, Daniel

    The study demonstrates: (1) the occurrence of verbal mediation with its facilitory effect, and (2) the interfering effect of verbal satiation on mediational processes in a three-state chaining paradigm. 40 preschool children were randomly assigned to either a control (no satiation) or an experimental (satiation) group. The subjects in the control…

  2. Integrating Mediators and Moderators in Research Design

    ERIC Educational Resources Information Center

    MacKinnon, David P.

    2011-01-01

    The purpose of this article is to describe mediating variables and moderating variables and provide reasons for integrating them in outcome studies. Separate sections describe examples of moderating and mediating variables and the simplest statistical model for investigating each variable. The strengths and limitations of incorporating mediating…

  3. Intercultural Conflict and Mediation: An Intergroup Perspective

    ERIC Educational Resources Information Center

    Rubenfeld, Sara; Clement, Richard

    2012-01-01

    This study investigates the role of components of intercultural competence in the use of intercultural mediation behaviors. Through the use of the Revised Intercultural Mediation Measure, an instrument revised by the authors, 291 Anglophone and 161 Francophone participants in Canada were asked to indicate their likelihood of employing various…

  4. Semiotic Mediation within an AT Frame

    ERIC Educational Resources Information Center

    Maracci, Mirko; Mariotti, Maria Alessandra

    2013-01-01

    This article is meant to present a specific elaboration of the notion of mediation in relation to the use of artefacts to enhance mathematics teaching and learning: the elaboration offered by the Theory of Semiotic Mediation. In particular, it provides an explicit model--consistent with the activity-actions-operations framework--of the actions…

  5. Sociocultural Theory and the Mediated Learning Experience.

    ERIC Educational Resources Information Center

    Kozulin, Alex

    2002-01-01

    Discusses the two theories that have contributed most to the development of the mediational approach to learning, Vygotskian sociocultural theory and Feuerstein's theory of Mediated Learning Experience. Both theories emphasize the importance of sociocultural forces in shaping a child's development and learning, and have generated a number of…

  6. Integrating Mediators and Moderators in Research Design

    PubMed Central

    MacKinnon, David P.

    2012-01-01

    The purpose of this article is to describe mediating variables and moderating variables and provide reasons for integrating them in outcome studies. Separate sections describe examples of moderating and mediating variables and the simplest statistical model for investigating each variable. The strengths and limitations of incorporating mediating and moderating variables in a research study are discussed as well as approaches to routinely including these variables in outcome research. The routine inclusion of mediating and moderating variables holds the promise of increasing the amount of information from outcome studies by generating practical information about interventions as well as testing theory. The primary focus is on mediating and moderating variables for intervention research but many issues apply to nonintervention research as well. PMID:22675239

  7. Integrating Mediators and Moderators in Research Design.

    PubMed

    Mackinnon, David P

    2011-11-01

    The purpose of this article is to describe mediating variables and moderating variables and provide reasons for integrating them in outcome studies. Separate sections describe examples of moderating and mediating variables and the simplest statistical model for investigating each variable. The strengths and limitations of incorporating mediating and moderating variables in a research study are discussed as well as approaches to routinely including these variables in outcome research. The routine inclusion of mediating and moderating variables holds the promise of increasing the amount of information from outcome studies by generating practical information about interventions as well as testing theory. The primary focus is on mediating and moderating variables for intervention research but many issues apply to nonintervention research as well.

  8. Meta-data based mediator generation

    SciTech Connect

    Critchlaw, T

    1998-06-28

    Mediators are a critical component of any data warehouse; they transform data from source formats to the warehouse representation while resolving semantic and syntactic conflicts. The close relationship between mediators and databases requires a mediator to be updated whenever an associated schema is modified. Failure to quickly perform these updates significantly reduces the reliability of the warehouse because queries do not have access to the most current data. This may result in incorrect or misleading responses, and reduce user confidence in the warehouse. Unfortunately, this maintenance may be a significant undertaking if a warehouse integrates several dynamic data sources. This paper describes a meta-data framework, and associated software, designed to automate a significant portion of the mediator generation task and thereby reduce the effort involved in adapting to schema changes. By allowing the DBA to concentrate on identifying the modifications at a high level, instead of reprogramming the mediator, turnaround time is reduced and warehouse reliability is improved.

  9. Pure Mediated Priming: A Retrospective Semantic Matching Model

    ERIC Educational Resources Information Center

    Jones, Lara L.

    2010-01-01

    Mediated priming refers to the activation of a target (e.g., "stripes") by a prime (e.g., "lion") that is related indirectly via a connecting mediator (e.g., tiger). In previous mediated priming studies (e.g., McNamara & Altarriba, 1988), the mediator was associatively related to the prime. In contrast, pure mediated priming (e.g., "spoon" [right…

  10. 7 CFR 785.5 - Fees for mediation services.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Fees for mediation services. 785.5 Section 785.5... AGRICULTURE SPECIAL PROGRAMS CERTIFIED STATE MEDIATION PROGRAM § 785.5 Fees for mediation services. A requirement that non-USDA parties who elect to participate in mediation pay a fee for mediation services...

  11. Elder Mediation in Theory and Practice: Study Results From a National Caregiver Mediation Demonstration Project

    PubMed Central

    Crampton, Alexandra

    2014-01-01

    Mediation is a process through which a third party facilitates discussion among disputing parties to help them identify interests and ideally reach an amicable solution. Elder mediation is a growing subspecialty to address conflicts involving older adults, primarily involving caregiving or finances. Mediation is theorized to empower participants but critics argue that it can exacerbate power imbalances among parties and coerce consensus. These contested claims are examined through study of a national caregiver mediation demonstration project. Study implications underscore the importance of gerontological social work expertise to ensure the empowerment of vulnerable older adults in mediation sessions. PMID:23767767

  12. Atomic Force Microscope Mediated Chromatography

    NASA Technical Reports Server (NTRS)

    Anderson, Mark S.

    2013-01-01

    The atomic force microscope (AFM) is used to inject a sample, provide shear-driven liquid flow over a functionalized substrate, and detect separated components. This is demonstrated using lipophilic dyes and normal phase chromatography. A significant reduction in both size and separation time scales is achieved with a 25-micron-length column scale, and one-second separation times. The approach has general applications to trace chemical and microfluidic analysis. The AFM is now a common tool for ultra-microscopy and nanotechnology. It has also been demonstrated to provide a number of microfluidic functions necessary for miniaturized chromatography. These include injection of sub-femtoliter samples, fluidic switching, and sheardriven pumping. The AFM probe tip can be used to selectively remove surface layers for subsequent microchemical analysis using infrared and tip-enhanced Raman spectroscopy. With its ability to image individual atoms, the AFM is a remarkably sensitive detector that can be used to detect separated components. These diverse functional components of microfluidic manipulation have been combined in this work to demonstrate AFM mediated chromatography. AFM mediated chromatography uses channel-less, shear-driven pumping. This is demonstrated with a thin, aluminum oxide substrate and a non-polar solvent system to separate a mixture of lipophilic dyes. In conventional chromatographic terms, this is analogous to thin-layer chromatography using normal phase alumina substrate with sheardriven pumping provided by the AFM tip-cantilever mechanism. The AFM detection of separated components is accomplished by exploiting the variation in the localized friction of the separated components. The AFM tip-cantilever provides the mechanism for producing shear-induced flows and rapid pumping. Shear-driven chromatography (SDC) is a relatively new concept that overcomes the speed and miniaturization limitations of conventional liquid chromatography. SDC is based on a

  13. Mediating chemical reactions using polysaccharides

    NASA Astrophysics Data System (ADS)

    Tyler, Lauren E.

    We have studied the NaBH4-mediated hydrogenation of select alkenes catalyzed by polysaccharide-stabilized nanoparticles. We compared the catalytic properties of Ni-based nanoparticles or Au/Co-based nanoparticles on the hydrogenation of cinnamic acid, cinnamide, cinnamyl alcohol, and ethyl cinnamate. We evaluated the possibility that the type of stabilizing polysaccharide surrounding the nanoparticle may affect the selectivity towards the alkene compounds that undergo the hydrogenation reaction. We found that the hydrogenation of cinnamide or ethyl cinnamate proceeded readily to 100% completion independent of the type of polysaccharide stabilizing the nanoparticle. However, the extent of the hydrogenation of cinnamyl alcohol and cinnamic acid varied greatly depending on the type of polysaccharide stabilizing the nanoparticle. In the course of these studies, we observed that some polysaccharides by themselves promoted the hydrolysis of ethyl cinnamate. Thus, we have raised the hypothesis that some polysaccharides may act as "esterases" and explored the interaction between select polysaccharides and a variety of ester compounds.

  14. Protease-mediated drug delivery

    NASA Astrophysics Data System (ADS)

    Dickson, Eva F.; Goyan, Rebecca L.; Kennedy, James C.; Mackay, M.; Mendes, M. A. K.; Pottier, Roy H.

    2003-12-01

    Drugs used in disease treatment can cause damage to both malignant and normal tissue. This toxicity limits the maximum therapeutic dose. Drug targeting is of high interest to increase the therapeutic efficacy of the drug without increasing systemic toxicity. Certain tissue abnormalities, disease processes, cancers, and infections are characterized by high levels of activity of specific extracellular and/or intracellular proteases. Abnormally high activity levels of specific proteases are present at sites of physical or chemical trauma, blood clots, malignant tumors, rheumatoid arthritis, inflammatory bowel disease, gingival disease, glomerulonerphritis, and acute pancreatitis. Abnormal protease activity is suspected in development of liver thrombosis, pulmonary emphysema, atherosclerosis, and muscular dystrophy. Inactiviating disease-associated proteases by the administration of appropriate protease inhibitors has had limited success. Instead, one could use such proteases to target drugs to treat the condition. Protease mediated drug delivery offers such a possibility. Solubilizing groups are attached to insoluble drugs via a polypeptide chain which is specifically cleavable by certian proteases. When the solubilized drug enounters the protease, the solubilizing moieties are cleaved, and the drug precipitates at the disease location. Thus, a smaller systemic dosage could result in a therapeutic drug concentration at the treatment site with less systemic toxicity.

  15. Bacterially mediated mineralization of vaterite

    NASA Astrophysics Data System (ADS)

    Rodriguez-Navarro, Carlos; Jimenez-Lopez, Concepcion; Rodriguez-Navarro, Alejandro; Gonzalez-Muñoz, Maria Teresa; Rodriguez-Gallego, Manuel

    2007-03-01

    Myxococcus xanthus, a common soil bacterium, plays an active role in the formation of spheroidal vaterite. Bacterial production of CO 2 and NH 3 and the transformation of the NH 3 to NH4+ and OH -, thus increasing solution pH and carbonate alkalinity, set the physicochemical conditions (high supersaturation) leading to vaterite precipitation in the microenvironment around cells, and directly onto the surface of bacterial cells. In the latter case, fossilization of bacteria occurs. Vaterite crystals formed by aggregation of oriented nanocrystals with c-axis normal to the bacterial cell-wall, or to the core of the spherulite when bacteria were not encapsulated. While preferred orientation of vaterite c-axis appears to be determined by electrostatic affinity (ionotropic effect) between vaterite crystal (0001) planes and the negatively charged functional groups of organic molecules on the bacterium cell-wall or on extracellular polymeric substances (EPS), analysis of the changes in the culture medium chemistry as well as high resolution transmission electron microscopy (HRTEM) observations point to polymorph selection by physicochemical (kinetic) factors (high supersaturation) and stabilization by organics, both connected with bacterial activity. The latter is in agreement with inorganic precipitation of vaterite induced by NH 3 and CO 2 addition in the protein-rich sterile culture medium. Our results as well as recent studies on vaterite precipitation in the presence of different types of bacteria suggest that bacterially mediated vaterite precipitation is not strain-specific, and could be more common than previously thought.

  16. Immunomodulatory Effects Mediated by Dopamine

    PubMed Central

    Alvarez-Herrera, Samantha; Pérez-Sánchez, Gilberto; Becerril-Villanueva, Enrique; Cruz-Fuentes, Carlos; Flores-Gutierrez, Enrique Octavio; Quintero-Fabián, Saray

    2016-01-01

    Dopamine (DA), a neurotransmitter in the central nervous system (CNS), has modulatory functions at the systemic level. The peripheral and central nervous systems have independent dopaminergic system (DAS) that share mechanisms and molecular machinery. In the past century, experimental evidence has accumulated on the proteins knowledge that is involved in the synthesis, reuptake, and transportation of DA in leukocytes and the differential expression of the D1-like (D1R and D5R) and D2-like receptors (D2R, D3R, and D4R). The expression of these components depends on the state of cellular activation and the concentration and time of exposure to DA. Receptors that are expressed in leukocytes are linked to signaling pathways that are mediated by changes in cAMP concentration, which in turn triggers changes in phenotype and cellular function. According to the leukocyte lineage, the effects of DA are associated with such processes as respiratory burst, cytokine and antibody secretion, chemotaxis, apoptosis, and cytotoxicity. In clinical conditions such as schizophrenia, Parkinson disease, Tourette syndrome, and multiple sclerosis (MS), there are evident alterations during immune responses in leukocytes, in which changes in DA receptor density have been observed. Several groups have proposed that these findings are useful in establishing clinical status and clinical markers. PMID:27795960

  17. GABA/progesterone-induced polyphosphoinositide (PPI) breakdown and its role in the acrosome reaction of guinea pig spermatozoa in vitro.

    PubMed

    Yuan, Y; Mao, L; Shi, Q; Roldan, E R; Chen, W; Yu, S; Zhuang, Y; Xu, S

    2001-08-01

    To investigate whether GABA/progesterone (P(4)) stimulates PPI breakdown and its role in the acrosome reaction (AR), spermatozoa of guinea pig were preincubated in MCM-LCa(2+) for 5.5 h and then labeled with [(32)P]pi for 1 h. Samples were washed through a three-step gradient Percoll, adjusted to 5x10(7) cells/mL and exposed to 2 mmol/L Ca(2+), 5 micromol/L GABA, 10 micromol/L P(4) and other agents. Lipids were separated by t.l.c. and radioactivity in spots determined by scintillation counting. The AR was assessed by phase-contrast microscopy. The results showed that (i) when spermatozoa were treated with GABA,(32)P-label diminished rapidly in phosphatidylinositol 4, 5-bisphosphate (PIP(2)), phosphatidylinositol 4-phosphate (PIP), and increased in phosphatidic acid (PA). The loss of label from PPI was almost completed by 10 min. The time-course of the AR was much slower than PPI when spermatozoa reached a maximal response by 15 min; (ii) the pattern of PPI hydrolysis and stimulation of AR was similar for the three agonists tested; their potency followed the order A23187>progesterone> or =GABA; (iii) GABA-induced PIP(2) hydrolysis and rise in PA and the AR were prevented by inclusion of 10 mmol/L neomycin; (iv) the loss of PIP(2) labeling and the increase in PA labeling abolished when spermatozoa were exposed to EGTA or Ca(2+) channel blocker. These results indicate that GABA or P(4)-induced PPI breakdown is an important and essential event in the series of changes to membrane fusion during the AR of guinea pig spermatozoa and this effect is mediated via calcium by activation of phosphatidylinositol-specific phospholipase C. PMID:18726415

  18. In vivo tracking of phosphoinositides in Drosophila photoreceptors

    PubMed Central

    Hardie, Roger C.; Liu, Che-Hsiung; Randall, Alexander S.; Sengupta, Sukanya

    2015-01-01

    ABSTRACT In order to monitor phosphoinositide turnover during phospholipase C (PLC)-mediated Drosophila phototransduction, fluorescently tagged lipid probes were expressed in photoreceptors and imaged both in dissociated cells, and in eyes of intact living flies. Of six probes tested, TbR332H (a mutant of the Tubby protein pleckstrin homology domain) was judged the best reporter for phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2], and the P4M domain from Legionella SidM for phosphatidylinositol 4-phosphate (PtdIns4P). Using accurately calibrated illumination, we found that only ∼50% of PtdIns(4,5)P2 and very little PtdIns4P were depleted by full daylight intensities in wild-type flies, but both were severely depleted by ∼100-fold dimmer intensities in mutants lacking Ca2+-permeable transient receptor potential (TRP) channels or protein kinase C (PKC). Resynthesis of PtdIns4P (t½ ∼12 s) was faster than PtdIns(4,5)P2 (t½ ∼40 s), but both were greatly slowed in mutants of DAG kinase (rdgA) or PtdIns transfer protein (rdgB). The results indicate that Ca2+- and PKC-dependent inhibition of PLC is required for enabling photoreceptors to maintain phosphoinositide levels despite high rates of hydrolysis by PLC, and suggest that phosphorylation of PtdIns4P to PtdIns(4,5)P2 is the rate-limiting step of the cycle. PMID:26483384

  19. Phosphoinositide 5- and 3-phosphatase activities of a voltage-sensing phosphatase in living cells show identical voltage dependence.

    PubMed

    Keum, Dongil; Kruse, Martin; Kim, Dong-Il; Hille, Bertil; Suh, Byung-Chang

    2016-06-28

    Voltage-sensing phosphatases (VSPs) are homologs of phosphatase and tensin homolog (PTEN), a phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2] and phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3] 3-phosphatase. However, VSPs have a wider range of substrates, cleaving 3-phosphate from PI(3,4)P2 and probably PI(3,4,5)P3 as well as 5-phosphate from phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and PI(3,4,5)P3 in response to membrane depolarization. Recent proposals say these reactions have differing voltage dependence. Using Förster resonance energy transfer probes specific for different PIs in living cells with zebrafish VSP, we quantitate both voltage-dependent 5- and 3-phosphatase subreactions against endogenous substrates. These activities become apparent with different voltage thresholds, voltage sensitivities, and catalytic rates. As an analytical tool, we refine a kinetic model that includes the endogenous pools of phosphoinositides, endogenous phosphatase and kinase reactions connecting them, and four exogenous voltage-dependent 5- and 3-phosphatase subreactions of VSP. We show that apparent voltage threshold differences for seeing effects of the 5- and 3-phosphatase activities in cells are not due to different intrinsic voltage dependence of these reactions. Rather, the reactions have a common voltage dependence, and apparent differences arise only because each VSP subreaction has a different absolute catalytic rate that begins to surpass the respective endogenous enzyme activities at different voltages. For zebrafish VSP, our modeling revealed that 3-phosphatase activity against PI(3,4,5)P3 is 55-fold slower than 5-phosphatase activity against PI(4,5)P2; thus, PI(4,5)P2 generated more slowly from dephosphorylating PI(3,4,5)P3 might never accumulate. When 5-phosphatase activity was counteracted by coexpression of a phosphatidylinositol 4-phosphate 5-kinase, there was accumulation of PI(4,5)P2 in parallel to PI(3,4,5)P3 dephosphorylation

  20. Contributions of protein kinases and β-arrestin to termination of protease-activated receptor 2 signaling

    PubMed Central

    Jung, Seung-Ryoung; Seo, Jong Bae; Deng, Yi; Asbury, Charles L.; Hille, Bertil

    2016-01-01

    Activated Gq protein–coupled receptors (GqPCRs) can be desensitized by phosphorylation and β-arrestin binding. The kinetics and individual contributions of these two mechanisms to receptor desensitization have not been fully distinguished. Here, we describe the shut off of protease-activated receptor 2 (PAR2). PAR2 activates Gq and phospholipase C (PLC) to hydrolyze phosphatidylinositol 4,5-bisphosphate (PIP2) into diacylglycerol and inositol trisphosphate (IP3). We used fluorescent protein–tagged optical probes to monitor several consequences of PAR2 signaling, including PIP2 depletion and β-arrestin translocation in real time. During continuous activation of PAR2, PIP2 was depleted transiently and then restored within a few minutes, indicating fast receptor activation followed by desensitization. Knockdown of β-arrestin 1 and 2 using siRNA diminished the desensitization, slowing PIP2 restoration significantly and even adding a delayed secondary phase of further PIP2 depletion. These effects of β-arrestin knockdown on PIP2 recovery were prevented when serine/threonine phosphatases that dephosphorylate GPCRs were inhibited. Thus, PAR2 may continuously regain its activity via dephosphorylation when there is insufficient β-arrestin to trap phosphorylated receptors. Similarly, blockers of protein kinase C (PKC) and G protein–coupled receptor kinase potentiated the PIP2 depletion. In contrast, an activator of PKC inhibited receptor activation, presumably by augmenting phosphorylation of PAR2. Our interpretations were strengthened by modeling. Simulations supported the conclusions that phosphorylation of PAR2 by protein kinases initiates receptor desensitization and that recruited β-arrestin traps the phosphorylated state of the receptor, protecting it from phosphatases. Speculative thinking suggested a sequestration of phosphatidylinositol 4-phosphate 5 kinase (PIP5K) to the plasma membrane by β-arrestin to explain why knockdown of β-arrestin led to

  1. 76 FR 19310 - Information Collection; Certified State Mediation Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-07

    ... Farm Service Agency Information Collection; Certified State Mediation Program AGENCY: Farm Service... Mediation Program. The information collection is necessary to ensure the grant program is being administered... following methods: Mail: Carol Wagner, Certified State Mediation Program Manager, USDA, FSA, Appeals...

  2. Immune-mediated disorders of cats.

    PubMed

    Werner, L L; Gorman, N T

    1984-09-01

    Immune-mediated disorders in cats share many clinical and pathologic similarities with their counterparts in other species. Cats, however, are unique among domestic animals owing to the involvement of feline leukemia virus. In addition, a number of other infectious organisms can produce immune-mediated sequelae--that is, FIP virus, FeSFV, and H. felis. Therefore, the diagnostic and therapeutic aims in the management of feline immune-mediated disorders must take into account the probability of a primary or underlying disease process. PMID:6149649

  3. [Role of internal mediators in surgical stress].

    PubMed

    Endo, Shigeatsu; Sato, Nobuhiro

    2003-12-01

    In surgical stress, internal mediators include cytokines released locally as well as into the circulation; activation of neutrophils, monocytes, macrophages, endothelial cells, platelets and other cells; activation of plasma protein cascade systems such the complement, coagulation, fibrinolytic and contact systems the release of tissue-damaging proteinases; the formation of lipid mediators such as eicosanoids and platelet-activating factor; and the generation of oxygen and nitrogen radicals. In addition, during host defense rections, a number of agents are released that blunt the inflammatory response, such as anti-inflamatory cytokines, soluble cytokine receptors, acute-phase proteins including proteinase inhibitors and stress hormones. In this paper, we explain such internal mediators.

  4. Gauge - Mediated Supersymmetry Breaking in String Compactifications

    SciTech Connect

    Diaconescu, Duiliu-Emanuel; Florea, Bogdan; Kachru, Shamit; Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC

    2006-01-04

    We provide string theory examples where a toy model of a SUSY GUT or the MSSM is embedded in a compactification along with a gauge sector which dynamically breaks supersymmetry. We argue that by changing microscopic details of the model (such as precise choices of flux), one can arrange for the dominant mediation mechanism transmitting SUSY breaking to the Standard Model to be either gravity mediation or gauge mediation. Systematic improvement of such examples may lead to top-down models incorporating a solution to the SUSY flavor problem.

  5. Electroporation-mediated gene delivery.

    PubMed

    Young, Jennifer L; Dean, David A

    2015-01-01

    Electroporation has been used extensively to transfer DNA to bacteria, yeast, and mammalian cells in culture for the past 30 years. Over this time, numerous advances have been made, from using fields to facilitate cell fusion, delivery of chemotherapeutic drugs to cells and tissues, and most importantly, gene and drug delivery in living tissues from rodents to man. Electroporation uses electrical fields to transiently destabilize the membrane allowing the entry of normally impermeable macromolecules into the cytoplasm. Surprisingly, at the appropriate field strengths, the application of these fields to tissues results in little, if any, damage or trauma. Indeed, electroporation has even been used successfully in human trials for gene delivery for the treatment of tumors and for vaccine development. Electroporation can lead to between 100 and 1000-fold increases in gene delivery and expression and can also increase both the distribution of cells taking up and expressing the DNA as well as the absolute amount of gene product per cell (likely due to increased delivery of plasmids into each cell). Effective electroporation depends on electric field parameters, electrode design, the tissues and cells being targeted, and the plasmids that are being transferred themselves. Most importantly, there is no single combination of these variables that leads to greatest efficacy in every situation; optimization is required in every new setting. Electroporation-mediated in vivo gene delivery has proven highly effective in vaccine production, transgene expression, enzyme replacement, and control of a variety of cancers. Almost any tissue can be targeted with electroporation, including muscle, skin, heart, liver, lung, and vasculature. This chapter will provide an overview of the theory of electroporation for the delivery of DNA both in individual cells and in tissues and its application for in vivo gene delivery in a number of animal models. PMID:25620008

  6. Electroporation-mediated gene delivery.

    PubMed

    Young, Jennifer L; Dean, David A

    2015-01-01

    Electroporation has been used extensively to transfer DNA to bacteria, yeast, and mammalian cells in culture for the past 30 years. Over this time, numerous advances have been made, from using fields to facilitate cell fusion, delivery of chemotherapeutic drugs to cells and tissues, and most importantly, gene and drug delivery in living tissues from rodents to man. Electroporation uses electrical fields to transiently destabilize the membrane allowing the entry of normally impermeable macromolecules into the cytoplasm. Surprisingly, at the appropriate field strengths, the application of these fields to tissues results in little, if any, damage or trauma. Indeed, electroporation has even been used successfully in human trials for gene delivery for the treatment of tumors and for vaccine development. Electroporation can lead to between 100 and 1000-fold increases in gene delivery and expression and can also increase both the distribution of cells taking up and expressing the DNA as well as the absolute amount of gene product per cell (likely due to increased delivery of plasmids into each cell). Effective electroporation depends on electric field parameters, electrode design, the tissues and cells being targeted, and the plasmids that are being transferred themselves. Most importantly, there is no single combination of these variables that leads to greatest efficacy in every situation; optimization is required in every new setting. Electroporation-mediated in vivo gene delivery has proven highly effective in vaccine production, transgene expression, enzyme replacement, and control of a variety of cancers. Almost any tissue can be targeted with electroporation, including muscle, skin, heart, liver, lung, and vasculature. This chapter will provide an overview of the theory of electroporation for the delivery of DNA both in individual cells and in tissues and its application for in vivo gene delivery in a number of animal models.

  7. Dark matter prospects in deflected mirage mediation

    SciTech Connect

    Holmes, Michael; Nelson, Brent D. E-mail: b.nelson@neu.edu

    2009-07-01

    The recently introduced deflected mirage mediation (DMM) model is a string-motivated paradigm in which all three of the major supersymmetry-breaking transmission mechanisms are operative. We begin a systematic exploration of the parameter space of this rich model context, paying special attention to the pattern of gaugino masses which arise. In this work we focus on the dark matter phenomenology of the DMM model as such signals are the least influenced by the model-dependent scalar masses. We find that a large portion of the parameter space in which the three mediation mechanisms have a similar effective mass scale of 1 TeV or less will be probed by future direct and indirect detection experiments. Distinguishing deflected mirage mediation from the mirage model without gauge mediation will prove difficult without collider input, though we indicate how gamma ray signals may provide an opportunity for distinguishing between the two paradigms.

  8. Programmable DNA-Mediated Multitasking Processor.

    PubMed

    Shu, Jian-Jun; Wang, Qi-Wen; Yong, Kian-Yan; Shao, Fangwei; Lee, Kee Jin

    2015-04-30

    Because of DNA appealing features as perfect material, including minuscule size, defined structural repeat and rigidity, programmable DNA-mediated processing is a promising computing paradigm, which employs DNAs as information storing and processing substrates to tackle the computational problems. The massive parallelism of DNA hybridization exhibits transcendent potential to improve multitasking capabilities and yield a tremendous speed-up over the conventional electronic processors with stepwise signal cascade. As an example of multitasking capability, we present an in vitro programmable DNA-mediated optimal route planning processor as a functional unit embedded in contemporary navigation systems. The novel programmable DNA-mediated processor has several advantages over the existing silicon-mediated methods, such as conducting massive data storage and simultaneous processing via much fewer materials than conventional silicon devices.

  9. 7 CFR 205.663 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM Administrative Compliance § 205.663 Mediation. Any dispute with...

  10. Selecting a model of supersymmetry breaking mediation

    SciTech Connect

    AbdusSalam, S. S.; Allanach, B. C.; Dolan, M. J.; Feroz, F.; Hobson, M. P.

    2009-08-01

    We study the problem of selecting between different mechanisms of supersymmetry breaking in the minimal supersymmetric standard model using current data. We evaluate the Bayesian evidence of four supersymmetry breaking scenarios: mSUGRA, mGMSB, mAMSB, and moduli mediation. The results show a strong dependence on the dark matter assumption. Using the inferred cosmological relic density as an upper bound, minimal anomaly mediation is at least moderately favored over the CMSSM. Our fits also indicate that evidence for a positive sign of the {mu} parameter is moderate at best. We present constraints on the anomaly and gauge mediated parameter spaces and some previously unexplored aspects of the dark matter phenomenology of the moduli mediation scenario. We use sparticle searches, indirect observables and dark matter observables in the global fit and quantify robustness with respect to prior choice. We quantify how much information is contained within each constraint.

  11. Genesis and intersubjectivity: levels of mediation.

    PubMed

    Yamamoto, Toshiya

    2012-09-01

    I will make a brief comment on the thesis of José C. Loredo-Narciandi and José C. Sánchez-González (2012) "Neither Dichotomies Nor Dualism; Simply Genesis". Denying any reductionism and reification, they insists the importance of inseparable relation between subject and object, then discuss about genesis. I pointed out that their argument lacks an important element, i.e., mediator that differ from mere physical object. After discussing mediators nature, I discriminate the three level of interaction which mediated by mediator. The first is the pre-interaction level, the second is physical interaction level and the third is sign or language interaction level. The last argument of mine is about how we can solve the problem of reification and reductionism. In the argument it is pointed out that intersubjectivity is key concept for understanding and solving the problem appropriately. PMID:22628155

  12. Programmable DNA-Mediated Multitasking Processor.

    PubMed

    Shu, Jian-Jun; Wang, Qi-Wen; Yong, Kian-Yan; Shao, Fangwei; Lee, Kee Jin

    2015-04-30

    Because of DNA appealing features as perfect material, including minuscule size, defined structural repeat and rigidity, programmable DNA-mediated processing is a promising computing paradigm, which employs DNAs as information storing and processing substrates to tackle the computational problems. The massive parallelism of DNA hybridization exhibits transcendent potential to improve multitasking capabilities and yield a tremendous speed-up over the conventional electronic processors with stepwise signal cascade. As an example of multitasking capability, we present an in vitro programmable DNA-mediated optimal route planning processor as a functional unit embedded in contemporary navigation systems. The novel programmable DNA-mediated processor has several advantages over the existing silicon-mediated methods, such as conducting massive data storage and simultaneous processing via much fewer materials than conventional silicon devices. PMID:25874653

  13. Upscaling of Bio-mediated Soil Improvement

    SciTech Connect

    J. T. DeJong; B. C. Martinez; B. M. Mortensen; D. C. Nelson; J. T. Waller; M. H. Weil; T. R. Ginn; T. Weathers; T. Barkouki; Y. Fujita; G. Redden; C. Hunt; D. Major; B. Tunyu

    2009-10-01

    As demand for soil improvement continues to increase, new, sustainable, and innocuous methods are needed to alter the mechanical properties of soils. Recent research has demonstrated the potential of bio-mediated soil improvement for geotechnical applications (DeJong et al. 2006, Whiffin et al. 2007). Upscaling the bio-mediated treatment process for in situ implementation presents a number of challenges to be addressed, including soil and pore fluid interactions, bioaugmentation versus biostimulation of microbial communities, controlled distribution of mediated calcite precipitation, and permanence of the cementation. Current studies are utilizing large-scale laboratory experiments, non-destructive geophysical measurements, and modeling, to develop an optimized and predictable bio-mediated treatment method.

  14. Confronting Conflict Peacefully: Peer Mediation in Schools.

    ERIC Educational Resources Information Center

    Cutrona, Cheryl; Guerin, Diane

    1994-01-01

    Suggests peer mediation as an alternative dispute resolution approach. Indicates the need to shift the focus from crisis intervention to prevention and to integrate dispute resolution skills into the school environment. (JOW)

  15. Genesis and intersubjectivity: levels of mediation.

    PubMed

    Yamamoto, Toshiya

    2012-09-01

    I will make a brief comment on the thesis of José C. Loredo-Narciandi and José C. Sánchez-González (2012) "Neither Dichotomies Nor Dualism; Simply Genesis". Denying any reductionism and reification, they insists the importance of inseparable relation between subject and object, then discuss about genesis. I pointed out that their argument lacks an important element, i.e., mediator that differ from mere physical object. After discussing mediators nature, I discriminate the three level of interaction which mediated by mediator. The first is the pre-interaction level, the second is physical interaction level and the third is sign or language interaction level. The last argument of mine is about how we can solve the problem of reification and reductionism. In the argument it is pointed out that intersubjectivity is key concept for understanding and solving the problem appropriately.

  16. Socially mediated learning in male Betta splendens.

    PubMed

    Bronstein, P M

    1986-09-01

    Seven experiments showed that in the absence of social stimulation male Siamese fighting fish would approach any of several visual and spatial cues that had previously been paired with the animals' mirror images. These findings demonstrate that learned modifications of swimming mediated by social stimuli are possible in Bettas. The present results also suggest that territorial defense in some teleosts may, in part, be mediated by the association of social cues with visual and spatial stimuli.

  17. Gazetteer Brokering through Semantic Mediation

    NASA Astrophysics Data System (ADS)

    Hobona, G.; Bermudez, L. E.; Brackin, R.

    2013-12-01

    web technologies, including ontologies and a semantic mediator. The semantically-enhanced SPEGG allowed a client to submit a single query (e.g. ';hills') and to retrieve data from two separate gazetteers with different vocabularies (e.g. where one refers to ';summits' another refers to ';hills'). Supporting the SPEGG was a SPARQL server that held the ontologies and processed queries on them. Earth Science surveys and forecast always have a place on Earth. Being able to share the information about a place and solve inconsistencies about that place from different sources will enable geoscientists to better do their research. In the advent of mobile geo computing and location based services (LBS), brokering gazetteers will provide geoscientists with access to gazetteer services rich with information and functionality beyond that offered by current generic gazetteers.

  18. 75 FR 52054 - Assessment of Mediation and Arbitration Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-24

    ... matters relating to the use of mediation and arbitration as effective means of resolving disputes that are... mediation and arbitration in the resolution of disputes. If so, the proposed changes or new rules would be... mediation and arbitration of matters subject to its jurisdiction. The Board's mediation rules are set...

  19. Estimating and Testing Mediation Effects with Censored Data

    ERIC Educational Resources Information Center

    Wang, Lijuan; Zhang, Zhiyong

    2011-01-01

    This study investigated influences of censored data on mediation analysis. Mediation effect estimates can be biased and inefficient with censoring on any one of the input, mediation, and output variables. A Bayesian Tobit approach was introduced to estimate and test mediation effects with censored data. Simulation results showed that the Bayesian…

  20. Surveying Parental Mediation: Connections, Challenges and Questions for Media Literacy

    ERIC Educational Resources Information Center

    Mendoza, Kelly

    2009-01-01

    This paper examines three strategies of parental mediation--coviewing, restrictive mediation, and active mediation--in order to make connections, challenge, and raise questions for media literacy. Coviewing, whether it is intentional practice, or whether it functions to promote media literacy, is explored. Restrictive mediation, how it connects to…

  1. The Peacekeepers: Students Use Mediation Skills to Resolve Conflicts.

    ERIC Educational Resources Information Center

    Meek, Michael

    1992-01-01

    Examines the use of mediation skills in elementary and secondary education. Discusses the rise in school violence; and describes mediation techniques, the rationale for their use, school programs to introduce mediation, peer mediators, and long-term benefits to students and the school community. Offers resources. (JB)

  2. Mediation...An Alternative That Works. Second Edition.

    ERIC Educational Resources Information Center

    Davis, Albie

    A 5-part handbook provides elementary and secondary educators and community organizations with background information and resources for teaching mediation strategies. An introduction (part I) provides a rationale for mediation as a form of dispute resolution and for mediation programs in the schools. Part II seeks to define mediation by describing…

  3. Reducing Levels of Elementary School Violence with Peer Mediation

    ERIC Educational Resources Information Center

    Schellenberg, Rita Cantrell; Parks-Savage, Agatha; Rehfuss, Mark

    2007-01-01

    The effectiveness of an existing peer mediation program in a diverse, suburban elementary school was examined. Peer mediation was available to all students (N = 825). Three-year longitudinal data showed significant reductions in the school's out-of-school suspensions after implementation of the peer mediation program. Mediation training also…

  4. A State Space Modeling Approach to Mediation Analysis

    ERIC Educational Resources Information Center

    Gu, Fei; Preacher, Kristopher J.; Ferrer, Emilio

    2014-01-01

    Mediation is a causal process that evolves over time. Thus, a study of mediation requires data collected throughout the process. However, most applications of mediation analysis use cross-sectional rather than longitudinal data. Another implicit assumption commonly made in longitudinal designs for mediation analysis is that the same mediation…

  5. 15 CFR 930.115 - Termination of mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Termination of mediation. 930.115... MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Secretarial Mediation § 930.115 Termination of mediation. Mediation shall terminate: (a) At any time the Federal and State agencies agree to...

  6. 29 CFR 1207.2 - Requests for Mediation Board action.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Requests for Mediation Board action. 1207.2 Section 1207.2 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD ESTABLISHMENT OF SPECIAL ADJUSTMENT BOARDS § 1207.2 Requests for Mediation Board action. (a) Requests for the National Mediation...

  7. What Do Grievants Think of Grievance Mediation: A Riposte to "Counterpoint: Response to Mediator Caraway."

    ERIC Educational Resources Information Center

    Jascourt, Hugh D.

    1992-01-01

    In a previous article, Gordon A. Gregory and Mark Heinen criticized John M. Caraway's article describing recent successful experiences with the use of mediation in place of arbitration for failing to note the perception of the grievants. A reexamination of the data show that 80 percent of the grievants were satisfied with the mediation procedure.…

  8. A neural mediator of human anxiety sensitivity.

    PubMed

    Harrison, Ben J; Fullana, Miquel A; Soriano-Mas, Carles; Via, Esther; Pujol, Jesus; Martínez-Zalacaín, Ignacio; Tinoco-Gonzalez, Daniella; Davey, Christopher G; López-Solà, Marina; Pérez Sola, Victor; Menchón, José M; Cardoner, Narcís

    2015-10-01

    Advances in the neuroscientific understanding of bodily autonomic awareness, or interoception, have led to the hypothesis that human trait anxiety sensitivity (AS)-the fear of bodily autonomic arousal-is primarily mediated by the anterior insular cortex. Despite broad appeal, few experimental studies have comprehensively addressed this hypothesis. We recruited 55 individuals exhibiting a range of AS and assessed them with functional magnetic resonance imaging (fMRI) during aversive fear conditioning. For each participant, three primary measures of interest were derived: a trait Anxiety Sensitivity Index score; an in-scanner rating of elevated bodily anxiety sensations during fear conditioning; and a corresponding estimate of whole-brain functional activation to the conditioned versus nonconditioned stimuli. Using a voxel-wise mediation analysis framework, we formally tested for 'neural mediators' of the predicted association between trait AS score and in-scanner anxiety sensations during fear conditioning. Contrary to the anterior insular hypothesis, no evidence of significant mediation was observed for this brain region, which was instead linked to perceived anxiety sensations independently from AS. Evidence for significant mediation was obtained for the dorsal anterior cingulate cortex-a finding that we argue is more consistent with the hypothesized role of human cingulofrontal cortex in conscious threat appraisal processes, including threat-overestimation. This study offers an important neurobiological validation of the AS construct and identifies a specific neural substrate that may underlie high AS clinical phenotypes, including but not limited to panic disorder. PMID:26147233

  9. Architecture of the Mediator head module

    SciTech Connect

    Imasaki, Tsuyoshi; Calero, Guillermo; Cai, Gang; Tsai, Kuang-Lei; Yamada, Kentaro; Cardelli, Francesco; Erdjument-Bromage, Hediye; Tempst, Paul; Berger, Imre; Kornberg, Guy Lorch; Asturias, Francisco J.; Kornberg, Roger D.; Takagi, Yuichiro

    2011-09-06

    Mediator is a key regulator of eukaryotic transcription, connecting activators and repressors bound to regulatory DNA elements with RNA polymerase II (Pol II). In the yeast Saccharomyces cerevisiae, Mediator comprises 25 subunits with a total mass of more than one megadalton (refs 5, 6) and is organized into three modules, called head, middle/arm and tail. Our understanding of Mediator assembly and its role in regulating transcription has been impeded so far by limited structural information. Here we report the crystal structure of the essential Mediator head module (seven subunits, with a mass of 223 kilodaltons) at a resolution of 4.3 angstroms. Our structure reveals three distinct domains, with the integrity of the complex centred on a bundle of ten helices from five different head subunits. An intricate pattern of interactions within this helical bundle ensures the stable assembly of the head subunits and provides the binding sites for general transcription factors and Pol II. Our structural and functional data suggest that the head module juxtaposes transcription factor IIH and the carboxy-terminal domain of the largest subunit of Pol II, thereby facilitating phosphorylation of the carboxy-terminal domain of Pol II. Our results reveal architectural principles underlying the role of Mediator in the regulation of gene expression.

  10. A neural mediator of human anxiety sensitivity.

    PubMed

    Harrison, Ben J; Fullana, Miquel A; Soriano-Mas, Carles; Via, Esther; Pujol, Jesus; Martínez-Zalacaín, Ignacio; Tinoco-Gonzalez, Daniella; Davey, Christopher G; López-Solà, Marina; Pérez Sola, Victor; Menchón, José M; Cardoner, Narcís

    2015-10-01

    Advances in the neuroscientific understanding of bodily autonomic awareness, or interoception, have led to the hypothesis that human trait anxiety sensitivity (AS)-the fear of bodily autonomic arousal-is primarily mediated by the anterior insular cortex. Despite broad appeal, few experimental studies have comprehensively addressed this hypothesis. We recruited 55 individuals exhibiting a range of AS and assessed them with functional magnetic resonance imaging (fMRI) during aversive fear conditioning. For each participant, three primary measures of interest were derived: a trait Anxiety Sensitivity Index score; an in-scanner rating of elevated bodily anxiety sensations during fear conditioning; and a corresponding estimate of whole-brain functional activation to the conditioned versus nonconditioned stimuli. Using a voxel-wise mediation analysis framework, we formally tested for 'neural mediators' of the predicted association between trait AS score and in-scanner anxiety sensations during fear conditioning. Contrary to the anterior insular hypothesis, no evidence of significant mediation was observed for this brain region, which was instead linked to perceived anxiety sensations independently from AS. Evidence for significant mediation was obtained for the dorsal anterior cingulate cortex-a finding that we argue is more consistent with the hypothesized role of human cingulofrontal cortex in conscious threat appraisal processes, including threat-overestimation. This study offers an important neurobiological validation of the AS construct and identifies a specific neural substrate that may underlie high AS clinical phenotypes, including but not limited to panic disorder.

  11. A default Bayesian hypothesis test for mediation.

    PubMed

    Nuijten, Michèle B; Wetzels, Ruud; Matzke, Dora; Dolan, Conor V; Wagenmakers, Eric-Jan

    2015-03-01

    In order to quantify the relationship between multiple variables, researchers often carry out a mediation analysis. In such an analysis, a mediator (e.g., knowledge of a healthy diet) transmits the effect from an independent variable (e.g., classroom instruction on a healthy diet) to a dependent variable (e.g., consumption of fruits and vegetables). Almost all mediation analyses in psychology use frequentist estimation and hypothesis-testing techniques. A recent exception is Yuan and MacKinnon (Psychological Methods, 14, 301-322, 2009), who outlined a Bayesian parameter estimation procedure for mediation analysis. Here we complete the Bayesian alternative to frequentist mediation analysis by specifying a default Bayesian hypothesis test based on the Jeffreys-Zellner-Siow approach. We further extend this default Bayesian test by allowing a comparison to directional or one-sided alternatives, using Markov chain Monte Carlo techniques implemented in JAGS. All Bayesian tests are implemented in the R package BayesMed (Nuijten, Wetzels, Matzke, Dolan, & Wagenmakers, 2014).

  12. Light mediators in dark matter direct detections

    SciTech Connect

    Li, Tai; Miao, Sen; Zhou, Yu-Feng

    2015-03-17

    In an extended effective operator framework, we investigate in detail the effects of light mediators on the event spectra of dark matter (DM)-nucleus scatterings. The presence of light mediators changes the interpretation of the current experimental data, especially the determination of DM particle mass. We show by analytic and numerical illustrations that in general for all the operators relevant to spin-independent scatterings, the DM particle mass allowed by a given set of experimental data increases significantly when the mediator particle becomes lighter. For instance, in the case of CDMS-II-Si experiment, the allowed DM particle mass can reach ∼50 (100) GeV at 68% (90%) confidence level, which is much larger than ∼10 GeV in the case with contact interactions. The increase of DM particle mass saturates when the mediator mass is below O(10) MeV. The upper limits from other experiments such as SuperCDMS, CDMSlite, CDEX, XENON10/100, LUX, PandaX etc. all tend to be weaker toward high DM mass regions. In a combined analysis, we show that the presence of light mediators can partially relax the tension in the current results of CDMS-II-Si, SuperCDMS and LUX.

  13. Light mediators in dark matter direct detections

    SciTech Connect

    Li, Tai; Miao, Sen; Zhou, Yu-Feng E-mail: miaosen@itp.ac.cn

    2015-03-01

    In an extended effective operator framework, we investigate in detail the effects of light mediators on the event spectra of dark matter (DM)-nucleus scatterings. The presence of light mediators changes the interpretation of the current experimental data, especially the determination of DM particle mass. We show by analytic and numerical illustrations that in general for all the operators relevant to spin-independent scatterings, the DM particle mass allowed by a given set of experimental data increases significantly when the mediator particle becomes lighter. For instance, in the case of CDMS-II-Si experiment, the allowed DM particle mass can reach ∼ 50 (100)  GeV at 68% (90%) confidence level, which is much larger than 0∼ 1 GeV in the case with contact interactions. The increase of DM particle mass saturates when the mediator mass is below O(10) MeV . The upper limits from other experiments such as SuperCDMS, CDMSlite, CDEX, XENON10/100, LUX, PandaX etc. all tend to be weaker toward high DM mass regions. In a combined analysis, we show that the presence of light mediators can partially relax the tension in the current results of CDMS-II-Si, SuperCDMS and LUX.

  14. An Exponential Decay Model for Mediation

    PubMed Central

    Fritz, Matthew S.

    2013-01-01

    Mediation analysis is often used to investigate mechanisms of change in prevention research. Results finding mediation are strengthened when longitudinal data are used because of the need for temporal precedence. Current longitudinal mediation models have focused mainly on linear change, but many variables in prevention change nonlinearly across time. The most common solution to nonlinearity is to add a quadratic term to the linear model, but this can lead to the use of the quadratic function to explain all nonlinearity, regardless of theory and the characteristics of the variables in the model. The current study describes the problems that arise when quadratic functions are used to describe all nonlinearity and how the use of nonlinear functions, such as exponential decay, addresses many of these problems. In addition, nonlinear models provide several advantages over polynomial models including usefulness of parameters, parsimony, and generalizability. The effects of using nonlinear functions for mediation analysis are then discussed and a nonlinear growth curve model for mediation is presented. An empirical example using data from a randomized intervention study is then provided to illustrate the estimation and interpretation of the model. Implications, limitations, and future directions are also discussed. PMID:23625557

  15. Surmounting elusive barriers: the case for bioethics mediation.

    PubMed

    Bergman, Edward J

    2013-01-01

    This article describes, analyzes, and advocates for management of clinical healthcare conflict by a process commonly referred to as bioethics mediation. Section I provides a brief introduction to classical mediation outside the realm of clinical healthcare. Section II highlights certain distinguishing characteristics of bioethics mediation. Section III chronicles the history of bioethics mediation and references a number of seminal writings on the subject. Finally, Section IV analyzes barriers that have, thus far, limited the widespread implementation of bioethics mediation.

  16. Intercellular Lipid Mediators and GPCR Drug Discovery

    PubMed Central

    Im, Dong-Soon

    2013-01-01

    G-protein-coupled receptors (GPCR) are the largest superfamily of receptors responsible for signaling between cells and tissues, and because they play important physiological roles in homeostasis, they are major drug targets. New technologies have been developed for the identification of new ligands, new GPCR functions, and for drug discovery purposes. In particular, intercellular lipid mediators, such as, lysophosphatidic acid and sphingosine 1-phosphate have attracted much attention for drug discovery and this has resulted in the development of fingolimod (FTY-720) and AM095. The discovery of new intercellular lipid mediators and their GPCRs are discussed from the perspective of drug development. Lipid GPCRs for lysophospholipids, including lysophosphatidylserine, lysophosphatidylinositol, lysophosphatidylcholine, free fatty acids, fatty acid derivatives, and other lipid mediators are reviewed. PMID:24404331

  17. Revisiting R-invariant direct gauge mediation

    NASA Astrophysics Data System (ADS)

    Chiang, Cheng-Wei; Harigaya, Keisuke; Ibe, Masahiro; Yanagida, Tsutomu T.

    2016-03-01

    We revisit a special model of gauge mediated supersymmetry breaking, the " R-invariant direct gauge mediation." We pay particular attention to whether the model is consistent with the minimal model of the μ-term, i.e., a simple mass term of the Higgs doublets in the superpotential. Although the incompatibility is highlighted in view of the current experimental constraints on the superparticle masses and the observed Higgs boson mass, the minimal μ-term can be consistent with the R-invariant gauge mediation model via a careful choice of model parameters. We derive an upper limit on the gluino mass from the observed Higgs boson mass. We also discuss whether the model can explain the 3 σ excess of the Z + jets + E T miss events reported by the ATLAS collaboration.

  18. Therapeutic strategies for tau mediated neurodegeneration

    PubMed Central

    Yoshiyama, Yasumasa; Lee, Virginia M Y; Trojanowski, John Q

    2014-01-01

    Based on the amyloid hypothesis, controlling β-amyloid protein (Aβ) accumulation is supposed to suppress downstream pathological events, tau accumulation, neurodegeneration and cognitive decline. However, in recent clinical trials, Aβ removal or reducing Aβ production has shown limited efficacy. Moreover, while active immunisation with Aβ resulted in the clearance of Aβ, it did not prevent tau pathology or neurodegeneration. This prompts the concern that it might be too late to employ Aβ targeting therapies once tau mediated neurodegeneration has occurred. Therefore, it is timely and very important to develop tau directed therapies. The pathomechanisms of tau mediated neurodegeneration are unclear but hyperphosphorylation, oligomerisation, fibrillisation and propagation of tau pathology have been proposed as the likely pathological processes that induce loss of function or gain of toxic function of tau, causing neurodegeneration. Here we review the strategies for tau directed treatments based on recent progress in research on tau and our understanding of the pathomechanisms of tau mediated neurodegeneration. PMID:23085937

  19. Agrobacterium-mediated transformation of cotton.

    PubMed

    Zhang, Baohong

    2013-01-01

    There are many methods and techniques that can be used to transfer foreign genes into cells. In plant biotechnology, Agrobacterium-mediated transformation is a widely used traditional method for inserting foreign genes into plant genome and obtaining transgenic plants, particularly for dicot plant species. Agrobacterium-mediated transformation of cotton involves several important and also critical steps, which includes coculture of cotton explants with Agrobacterium, induction and selection of stable transgenic cell lines, recovery of plants from transgenic cells majorly through somatic embryogenesis, and detection and expression analysis of transgenic plants. In this chapter, we describe a detailed step-by-step protocol for obtaining transgenic cotton plants via Agrobacterium-mediated transformation.

  20. Mediator kinase module and human tumorigenesis

    PubMed Central

    Clark, Alison D.; Oldenbroek, Marieke; Boyer, Thomas G.

    2016-01-01

    Mediator is a conserved multi-subunit signal processor through which regulatory informatiosn conveyed by gene-specific transcription factors is transduced to RNA Polymerase II (Pol II). In humans, MED13, MED12, CDK8 and Cyclin C (CycC) comprise a four-subunit “kinase” module that exists in variable association with a 26-subunit Mediator core. Genetic and biochemical studies have established the Mediator kinase module as a major ingress of developmental and oncogenic signaling through Mediator, and much of its function in signal-dependent gene regulation derives from its resident CDK8 kinase activity. For example, CDK8-targeted substrate phosphorylation impacts transcription factor half-life, Pol II activity and chromatin chemistry and functional status. Recent structural and biochemical studies have revealed a precise network of physical and functional subunit interactions required for proper kinase module activity. Accordingly, pathologic change in this activity through altered expression or mutation of constituent kinase module subunits can have profound consequences for altered signaling and tumor formation. Herein, we review the structural organization, biological function and oncogenic potential of the Mediator kinase module. We focus principally on tumor-associated alterations in kinase module subunits for which mechanistic relationships as opposed to strictly correlative associations are established. These considerations point to an emerging picture of the Mediator kinase module as an oncogenic unit, one in which pathogenic activation/deactivation through component change drives tumor formation through perturbation of signal-dependent gene regulation. It follows that therapeutic strategies to combat CDK8-driven tumors will involve targeted modulation of CDK8 activity or pharmacologic manipulation of dysregulated CDK8-dependent signaling pathways. PMID:26182352

  1. Transition to whistler mediated magnetic reconnection

    NASA Technical Reports Server (NTRS)

    Mandt, M. E.; Denton, R. E.; Drake, J. F.

    1994-01-01

    The transition in the magnetic reconnection rate from the resistive magnetohydrodynamic (MHD) regime where the Alfen wave controls reconnection to a regime in which the ions become unmagnetized and the whistler wave mediates reconnection is explored with 2-D hybrid simulations. In the whistler regime the electrons carry the currents while the ions provide a neutralizing background. A simple physical picture is presented illustrating the role of the whistler mediated reconnection is calculated analytically. The development of an out-of-plane component of the magnetic field is an observable signature of whistler driven reconnection.

  2. Magnetically mediated thermoacoustic imaging toward deeper penetration

    NASA Astrophysics Data System (ADS)

    Feng, Xiaohua; Gao, Fei; Zheng, Yuanjin

    2013-08-01

    Magnetically mediated thermo-acoustic effect is predicted in theory and demonstrated in phantom studies in this letter. By applying transient current to a compact magnetically resonant coil at radio frequency below 20 MHz, large electric field is inducted by magnetic field inside conductive objects which then undergoes joule heating and emanates acoustic signal thermo-elastically. The magnetic mediation approach with low radio frequency can provide deeper penetration into conductive objects which may extend thermoacoustic imaging to deep laid human organs. Both incoherent time domain and coherent frequency domain approaches are discussed with the latter demonstrated potential for portable imaging system.

  3. Barley Transformation Using Agrobacterium-Mediated Techniques

    NASA Astrophysics Data System (ADS)

    Harwood, Wendy A.; Bartlett, Joanne G.; Alves, Silvia C.; Perry, Matthew; Smedley, Mark A.; Leyland, Nicola; Snape, John W.

    Methods for the transformation of barley using Agrobacterium-mediated techniques have been available for the past 10 years. Agrobacterium offers a number of advantages over biolistic-mediated techniques in terms of efficiency and the quality of the transformed plants produced. This chapter describes a simple system for the transformation of barley based on the infection of immature embryos with Agrobacterium tumefaciens followed by the selection of transgenic tissue on media containing the antibiotic hygromycin. The method can lead to the production of large numbers of fertile, independent transgenic lines. It is therefore ideal for studies of gene function in a cereal crop system.

  4. Exosomes: mediators of neurodegeneration, neuroprotection and therapeutics.

    PubMed

    Kalani, Anuradha; Tyagi, Alka; Tyagi, Neetu

    2014-02-01

    Exosomes have emerged as prominent mediators of neurodegenerative diseases where they have been shown to carry disease particles such as beta amyloid and prions from their cells of origin to other cells. Their simple structure and ability to cross the blood-brain barrier allow great opportunity to design a "makeup" with drugs and genetic elements, such as siRNA or miRNA, and use them as delivery vehicles for neurotherapeutics. Their role in neuroprotection is evident by the fact that they are involved in the regeneration of peripheral nerves and repair of neuronal injuries. This review is focused on the role of exosomes in mediating neurodegeneration and neuroprotection.

  5. A security mediator for health care information.

    PubMed Central

    Wiederhold, G.; Bilello, M.; Sarathy, V.; Qian, X.

    1996-01-01

    The TIHI (Trusted Interoperation of Healthcare Information) project addresses a security issue that arises when some information is being shared among collaborating enterprises, although not all enterprise information is sharable. It assumes that protection exists to prevent intrusion by adversaries through secure transmission and firewalls. The TIHI system design provides a gateway, owned by the enterprise security officer, to mediate queries and responses. The latter are typically transmitted via the Internet. The enterprise policy is determined by rules provided to the mediator. We show examples of typical rules. The problem and our solution, although developed in a healthcare context, is equally valid among collaborating enterprises. PMID:8947640

  6. Redox polymer mediation for enzymatic biofuel cells

    NASA Astrophysics Data System (ADS)

    Gallaway, Joshua

    Mediated biocatalytic cathodes prepared from the oxygen-reducing enzyme laccase and redox-conducting osmium hydrogels were characterized for use as cathodes in enzymatic biofuel cells. A series of osmium-based redox polymers was synthesized with redox potentials spanning the range from 0.11 V to 0.85 V (SHE), and the resulting biocatalytic electrodes were modeled to determine reaction kinetic constants using the current response, measured osmium concentration, and measured apparent electron diffusion. As in solution-phase systems, the bimolecular rate constant for mediation was found to vary greatly with mediator potential---from 250 s-1M-1 when mediator and enzyme were close in potential to 9.4 x 10 4 s-1M-1 when this overpotential was large. Optimum mediator potential for a cell operating with a non-limiting platinum anode and having no mass transport limitation from bulk solution was found to be 0.66 V (SHE). Redox polymers were synthesized under different concentrations, producing osmium variation. An increase from 6.6% to 7.2% osmium increased current response from 1.2 to 2.1 mA/cm2 for a planar film in 40°C oxygen-saturated pH 4 buffer, rotating at 900 rpm. These results translated to high surface area electrodes, nearly doubling current density to 13 mA/cm2, the highest to date for such an electrode. The typical fungal laccase from Trametes versicolor was replaced by a bacterially-expressed small laccase from Streptomyces coelicolor, resulting in biocatalytic films that reduced oxygen at increased pH, with full functionality at pH 7, producing 1.5 mA/cm 2 in planar configuration. Current response was biphasic with pH, matching the activity profile of the free enzyme in solution. The mediated enzyme electrode system was modeled with respect to apparent electron diffusion, mediator concentration, and transport of oxygen from bulk solution, all of which are to some extent controlled by design. Each factor was found to limit performance in certain circumstances

  7. Simultaneous backward conditioned inhibition and mediated conditioning.

    PubMed

    Graham, Steven; Jie, Hans Lee; Chan, Hui-Minn; McLaren, I P L; Wills, Andy J

    2011-04-01

    Demonstrations of retrospective revaluation suggest that remembered stimuli undergo a reduction in association with the unconditioned stimulus (US) present during learning. Conversely, demonstrations of mediated conditioning in flavor-conditioning experiments with rats suggest that remembered stimuli undergo an increase in association with the US present during learning. In a food allergy prediction task with 23 undergraduates, we demonstrated simultaneous backward conditioned inhibition and mediated conditioning effects. These results are compatible with the hypothesis that the direction of change (decrease or increase) in associative strength depends on whether the remembered stimulus was of a different category (conditioned stimulus/antecedent) or the same category (US/outcome) as the presented US. PMID:21319913

  8. Auxin-dependent compositional change in Mediator in ARF7- and ARF19-mediated transcription.

    PubMed

    Ito, Jun; Fukaki, Hidehiro; Onoda, Makoto; Li, Lin; Li, Chuanyou; Tasaka, Masao; Furutani, Masahiko

    2016-06-01

    Mediator is a multiprotein complex that integrates the signals from transcription factors binding to the promoter and transmits them to achieve gene transcription. The subunits of Mediator complex reside in four modules: the head, middle, tail, and dissociable CDK8 kinase module (CKM). The head, middle, and tail modules form the core Mediator complex, and the association of CKM can modify the function of Mediator in transcription. Here, we show genetic and biochemical evidence that CKM-associated Mediator transmits auxin-dependent transcriptional repression in lateral root (LR) formation. The AUXIN/INDOLE 3-ACETIC ACID 14 (Aux/IAA14) transcriptional repressor inhibits the transcriptional activity of its binding partners AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 by making a complex with the CKM-associated Mediator. In addition, TOPLESS (TPL), a transcriptional corepressor, forms a bridge between IAA14 and the CKM component MED13 through the physical interaction. ChIP assays show that auxin induces the dissociation of MED13 but not the tail module component MED25 from the ARF7 binding region upstream of its target gene. These findings indicate that auxin-induced degradation of IAA14 changes the module composition of Mediator interacting with ARF7 and ARF19 in the upstream region of their target genes involved in LR formation. We suggest that this regulation leads to a quick switch of signal transmission from ARFs to target gene expression in response to auxin. PMID:27217573

  9. Auxin-dependent compositional change in Mediator in ARF7- and ARF19-mediated transcription

    PubMed Central

    Ito, Jun; Fukaki, Hidehiro; Onoda, Makoto; Li, Lin; Li, Chuanyou; Tasaka, Masao; Furutani, Masahiko

    2016-01-01

    Mediator is a multiprotein complex that integrates the signals from transcription factors binding to the promoter and transmits them to achieve gene transcription. The subunits of Mediator complex reside in four modules: the head, middle, tail, and dissociable CDK8 kinase module (CKM). The head, middle, and tail modules form the core Mediator complex, and the association of CKM can modify the function of Mediator in transcription. Here, we show genetic and biochemical evidence that CKM-associated Mediator transmits auxin-dependent transcriptional repression in lateral root (LR) formation. The AUXIN/INDOLE 3-ACETIC ACID 14 (Aux/IAA14) transcriptional repressor inhibits the transcriptional activity of its binding partners AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 by making a complex with the CKM-associated Mediator. In addition, TOPLESS (TPL), a transcriptional corepressor, forms a bridge between IAA14 and the CKM component MED13 through the physical interaction. ChIP assays show that auxin induces the dissociation of MED13 but not the tail module component MED25 from the ARF7 binding region upstream of its target gene. These findings indicate that auxin-induced degradation of IAA14 changes the module composition of Mediator interacting with ARF7 and ARF19 in the upstream region of their target genes involved in LR formation. We suggest that this regulation leads to a quick switch of signal transmission from ARFs to target gene expression in response to auxin. PMID:27217573

  10. Bioethics mediation: the role and importance of nursing advocacy.

    PubMed

    Schlairet, Maura C

    2009-01-01

    Ethics consultations are utilized in health care to identify and manage conflict, difficult decision-making, and ethical issues. In bioethics mediation, a more updated approach using interpersonal, mediative, conflict management, and dispute resolution skills is merged with ethical principles to manage dilemmas arising in healthcare settings. This article argues, based on a professional obligation to advocate for the good of the client, that nurses must assume leadership roles in mediation processes. Nurses can initiate and fully participate in formal bioethics mediation and other mediative interventions. Nurse administrators can work to evolve existing ethics consult models to mediation models. Nonetheless, mediative efforts of individual nurses must be grounded in realization of the multifactorial nature of conflict and dilemma in healthcare settings. Multidisciplinary mediative interventions, framed by sound institutional policies, may best serve the complex needs of ethically vulnerable clients. To best advocate for these at-risk clients, nurses must assume various leadership roles in mediation processes. PMID:19631060

  11. Nonthermal dark matter in mirage mediation

    SciTech Connect

    Nagai, Minoru; Nakayama, Kazunori

    2007-12-15

    In mirage-mediation models there exists a modulus field whose mass is O(1000) TeV and its late decay may significantly change the standard thermal relic scenario of the dark matter. We study nonthermal production of the dark matter directly from the modulus decay, and find that for some parameter regions nonthermally produced neutralinos can become the dark matter.

  12. Comments: Causal Interpretations of Mediation Effects

    ERIC Educational Resources Information Center

    Jo, Booil; Stuart, Elizabeth A.

    2012-01-01

    The authors thank Dr. Lindsay Page for providing a nice illustration of the use of the principal stratification framework to define causal effects, and a Bayesian model for effect estimation. They hope that her well-written article will help expose education researchers to these concepts and methods, and move the field of mediation analysis in…

  13. 34 CFR 300.506 - Mediation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Mediation. 300.506 Section 300.506 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN WITH DISABILITIES Procedural Safeguards Due...

  14. Cell-mediated Protection in Influenza Infection

    PubMed Central

    Thomas, Paul G.; Keating, Rachael; Hulse-Post, Diane J.

    2006-01-01

    Current vaccine strategies against influenza focus on generating robust antibody responses. Because of the high degree of antigenic drift among circulating influenza strains over the course of a year, vaccine strains must be reformulated specifically for each influenza season. The time delay from isolating the pandemic strain to large-scale vaccine production would be detrimental in a pandemic situation. A vaccine approach based on cell-mediated immunity that avoids some of these drawbacks is discussed here. Specifically, cell-mediated responses typically focus on peptides from internal influenza proteins, which are far less susceptible to antigenic variation. We review the literature on the role of CD4+ and CD8+ T cell–mediated immunity in influenza infection and the available data on the role of these responses in protection from highly pathogenic influenza infection. We discuss the advantages of developing a vaccine based on cell-mediated immune responses toward highly pathogenic influenza virus and potential problems arising from immune pressure. PMID:16494717

  15. Proteases in Fas-mediated apoptosis.

    PubMed

    Zhivotovsky, B; Burgess, D H; Schlegel, J; Pörn, M I; Vanags, D; Orrenius, S

    1997-01-01

    Involvement of a unique family of cysteine proteases in the multistep apoptotic process has been documented. Cloning of several mammalian genes identifies some components of this cellular response. However, it is currently unclear which protease plays a role as a signal and/or effector of apoptosis. We summarize contributions to the data concerning proteases in Fas-mediated apoptosis.

  16. Computer Mediated Communication: Online Instruction and Interactivity.

    ERIC Educational Resources Information Center

    Lavooy, Maria J.; Newlin, Michael H.

    2003-01-01

    Explores the different forms and potential applications of computer mediated communication (CMC) for Web-based and Web-enhanced courses. Based on their experiences with three different Web courses (Research Methods in Psychology, Statistical Methods in Psychology, and Basic Learning Processes) taught repeatedly over the last five years, the…

  17. 10 CFR 1040.89-6 - Mediation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Federal Mediation and Conciliation Service, in accordance with 45 CFR 90.43(c)(3), all complaints that: (1... of Civil Rights and Diversity, will accept a judgment that an agreement is not possible. However, the... Director, Office of Civil Rights and Diversity, DOE. DOE will take no further action on the...

  18. 10 CFR 1040.89-6 - Mediation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Federal Mediation and Conciliation Service, in accordance with 45 CFR 90.43(c)(3), all complaints that: (1... of Civil Rights and Diversity, will accept a judgment that an agreement is not possible. However, the... Director, Office of Civil Rights and Diversity, DOE. DOE will take no further action on the...

  19. 10 CFR 1040.89-6 - Mediation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Federal Mediation and Conciliation Service, in accordance with 45 CFR 90.43(c)(3), all complaints that: (1... of Civil Rights and Diversity, will accept a judgment that an agreement is not possible. However, the... Director, Office of Civil Rights and Diversity, DOE. DOE will take no further action on the...

  20. 10 CFR 1040.89-6 - Mediation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Federal Mediation and Conciliation Service, in accordance with 45 CFR 90.43(c)(3), all complaints that: (1... of Civil Rights and Diversity, will accept a judgment that an agreement is not possible. However, the... Director, Office of Civil Rights and Diversity, DOE. DOE will take no further action on the...

  1. Teaching Responsibly with Technology-Mediated Communication

    ERIC Educational Resources Information Center

    Veltsos, Jennifer R.; Veltsos, Christophe

    2010-01-01

    Technology-mediated communication, or "new media," such as blogs, Twitter, wikis, and social network sites, can be an endless source of ideas for activities or inspiration for classroom discussion. Many instructors ask students to monitor current events by following keywords and industry leaders on Twitter and reading both corporate and trade…

  2. A Comparison of Three Tests of Mediation

    ERIC Educational Resources Information Center

    Warbasse, Rosalia E.

    2009-01-01

    A simulation study was conducted to evaluate the performance of three tests of mediation: the bias-corrected and accelerated bootstrap (Efron & Tibshirani, 1993), the asymmetric confidence limits test (MacKinnon, 2008), and a multiple regression approach described by Kenny, Kashy, and Bolger (1998). The evolution of these methods is reviewed and…

  3. Learning Style Theory and Computer Mediated Communication.

    ERIC Educational Resources Information Center

    Atkins, Hilary; Moore, David; Sharpe, Simon; Hobbs, Dave

    This paper looks at the low participation rates in computer mediated conferences (CMC) and argues that one of the causes of this may be an incompatibility between students' learning styles and the style adopted by CMC. Curry's Onion Model provides a well-established framework within which to view the main learning style theories (Riding and…

  4. Instructional Components of Mediational Dynamic Assessment.

    ERIC Educational Resources Information Center

    Symons, Sonya E.; Vye, Nancy J.

    The instructional components of mediation, a teaching technique used in dynamic assessment, were evaluated with 100 four-year-old children attending daycare or preschools in London, Ontario. The effects of familiarization with task materials, task-specific rule teaching, and elaborated feedback were assessed using a pretest-posttest design.…

  5. Deflected anomaly mediation and neutralino dark matter

    SciTech Connect

    Cesarini, Alessandro; Fucito, Francesco; Lionetto, Andrea

    2007-01-15

    This is a study of the phenomenology of the neutralino dark matter in the so called deflected anomaly mediation scenario. This scheme is obtained from the minimal anomaly-mediated scenario by introducing a gauge-mediated sector with N{sub f} messenger fields. Unlike the former scheme the latter has no tachyons. We find that the neutralino is still the LSP in a wide region of the parameter space: it is essentially a pure bino in the scenario with N{sub f}=1 while it can also be a pure Higgsino for N{sub f}>1. This is very different from the naive anomaly-mediated scenario which predicts a wino like neutralino. Moreover we do not find any tachyonic scalars in this scheme. After computing the relic density (considering all the possible coannihilations) we find that there are regions in the parameter space with values compatible with the latest WMAP results with no need to consider moduli fields that decay in the early universe.

  6. Conflict Resolution and Mediation for Peer Helpers.

    ERIC Educational Resources Information Center

    Sorenson, Don L.

    This book explores conflict resolution strategies and presents a systematic approach to mediation for peer helpers. The first part examines conflict resolution. Internal and external sources of conflict are considered. Irritations, inappropriate expectations, and unknown sources of external conflict are examined. A section on looking inside…

  7. Web-Mediated Knowledge Synthesis for Educators

    ERIC Educational Resources Information Center

    DeSchryver, Michael

    2015-01-01

    Ubiquitous and instant access to information on the Web is challenging what constitutes 21st century literacies. This article explores the notion of Web-mediated knowledge synthesis, an approach to integrating Web-based learning that may result in generative synthesis of ideas. This article describes the skills and strategies that may support…

  8. MEDIATORS OF PHYSICAL ACTIVITY BEHAVIOR CHANGE

    PubMed Central

    Napolitano, Melissa A.; Papandonatos, George D.; Lewis, Beth A.; Whiteley, Jessica A.; Williams, David M.; King, Abby C.; Bock, Beth C.; Pinto, Bernardine; Marcus, Bess H.

    2009-01-01

    Using a multivariate extension of the Baron and Kenny (1986) mediation framework, we examined the simultaneous effect of psychosocial variables hypothesized to mediate the relationship between a motivationally-tailored physical activity intervention, and 6-month physical activity behavior in 239 healthy, under-active adults (mean age=47.5; 82% women). Participants were randomly assigned to 1) Print-based feedback; 2) Telephone-based feedback; or 3) Contact Control. All mediation criteria were satisfied for both intervention arms. In terms of effect size, a moderate indirect effect of Print (0.39, 95% CI=0.21, 0.57) was due to increases in behavioral processes (0.54, 95% CI= 0.29, 0.80) being attenuated by decreases due to cognitive processes (-0.17, 95%CI= -0.31,-.03). A moderate indirect effect was observed for Telephone (0.47, 95% CI=0.28, 0.66), with increases due to behavioral processes (0.61, 95% CI=0.34, 0.87) attenuated by decreases due to cognitive processes (0.15, 95% CI=-0.27, -0.02); self-efficacy and decisional balance mediational paths did not attain statistical significance. These findings highlight the importance of studies that deconstruct the theoretical components of interventions to determine which combination produces the greatest behavior changes at the lowest cost. PMID:18642998

  9. Factors Mediating the Adjustment to Involuntary Childlessness.

    ERIC Educational Resources Information Center

    Sabatelli, Ronald M.; And Others

    1988-01-01

    Explored stressors that accompany experience of involuntary childlessness and examined mediators of adjustment to infertility in married individuals. Data showed deleterious effect that coping with infertility can have on couple's sexual relationship. Findings suggest important relationship between self-esteem, marital commitment, and positive…

  10. 15 CFR 923.54 - Mediation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... an appropriate forum for conflict resolution. (b) State-Federal differences should be addressed... parties agree to a resolution of the serious disagreement, (2) If one of the parties withdraws from mediation, (3) In the event the parties fail to reach a resolution of the serious disagreement within...

  11. 15 CFR 923.54 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... an appropriate forum for conflict resolution. (b) State-Federal differences should be addressed... parties agree to a resolution of the serious disagreement, (2) If one of the parties withdraws from mediation, (3) In the event the parties fail to reach a resolution of the serious disagreement within...

  12. Maternally-Mediated Effects on Development*

    EPA Science Inventory

    In standard Segment II mammalian bioassays for developmental toxicity, it is the pregnant animal that is exposed to the test article, so in this sense, all in utero developmental toxicity is mediated by the mother. This will include absorption, distribution, metabolism and excret...

  13. Computer-Mediated Communication on the Internet.

    ERIC Educational Resources Information Center

    Herring, Susan C.

    2002-01-01

    This review of computer-mediated communication (CMC) on the Internet focuses on empirical research in noninstitutional and nonorganizational contexts. Highlights include modes of CMC; appropriate uses; social effects; effects on language and communication; freedom of expression; community; personal impacts; privacy; ethics; democracy;…

  14. Mediating Artifact in Teacher Professional Development

    NASA Astrophysics Data System (ADS)

    Svendsen, Bodil

    2015-07-01

    This article focuses on teacher professional development (TPD) in natural science through the 5E model as mediating artifact. The study was conducted in an upper secondary school, grounded in a school-based intervention research project. My contribution to the field of research on TPD is founded on the hypothesis that teachers would be best facilitated to make their practice more inquiry based if they are provided with a mediating artifact. In this study the artifact is a model 5E, which is a conceptual way of thinking, to help teachers reflect on their practice. The aim is to encourage teachers to make changes themselves, by applying extended use of inquiry into their practice. This mediated artifact could thus be used across different national contexts. The main research question is; how can the 5E model as a mediating artifact enhance TPD? The article addresses the processes of the use of the 5E model and its influence on teachers' perception of the model. This is in order for teachers to conceptualize their goals related to inquiry and scientific thinking, and to solve the problems involved in achieving those goals in their own contexts. The study concludes that, after the intervention, the teachers' approaches and strategies demonstrate greater emphasis on learning.

  15. Proteinaceous Molecules Mediating Bifidobacterium-Host Interactions

    PubMed Central

    Ruiz, Lorena; Delgado, Susana; Ruas-Madiedo, Patricia; Margolles, Abelardo; Sánchez, Borja

    2016-01-01

    Bifidobacteria are commensal microoganisms found in the gastrointestinal tract. Several strains have been attributed beneficial traits at local and systemic levels, through pathogen exclusion or immune modulation, among other benefits. This has promoted a growing industrial and scientific interest in bifidobacteria as probiotic supplements. However, the molecular mechanisms mediating this cross-talk with the human host remain unknown. High-throughput technologies, from functional genomics to transcriptomics, proteomics, and interactomics coupled to the development of both in vitro and in vivo models to study the dynamics of the intestinal microbiota and their effects on host cells, have eased the identification of key molecules in these interactions. Numerous secreted or surface-associated proteins or peptides have been identified as potential mediators of bifidobacteria-host interactions and molecular cross-talk, directly participating in sensing environmental factors, promoting intestinal colonization, or mediating a dialogue with mucosa-associated immune cells. On the other hand, bifidobacteria induce the production of proteins in the intestine, by epithelial or immune cells, and other gut bacteria, which are key elements in orchestrating interactions among bifidobacteria, gut microbiota, and host cells. This review aims to give a comprehensive overview on proteinaceous molecules described and characterized to date, as mediators of the dynamic interplay between bifidobacteria and the human host, providing a framework to identify knowledge gaps and future research needs. PMID:27536282

  16. Excursion-Set-Mediated Genetic Algorithm

    NASA Technical Reports Server (NTRS)

    Noever, David; Baskaran, Subbiah

    1995-01-01

    Excursion-set-mediated genetic algorithm (ESMGA) is embodiment of method of searching for and optimizing computerized mathematical models. Incorporates powerful search and optimization techniques based on concepts analogous to natural selection and laws of genetics. In comparison with other genetic algorithms, this one achieves stronger condition for implicit parallelism. Includes three stages of operations in each cycle, analogous to biological generation.

  17. 7 CFR 205.663 - Mediation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Mediation. 205.663 Section 205.663 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION...

  18. 7 CFR 205.663 - Mediation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Mediation. 205.663 Section 205.663 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION...

  19. Synchronous Computer-Mediated Communication and Interaction

    ERIC Educational Resources Information Center

    Ziegler, Nicole

    2016-01-01

    The current study reports on a meta-analysis of the relative effectiveness of interaction in synchronous computer-mediated communication (SCMC) and face-to-face (FTF) contexts. The primary studies included in the analysis were journal articles and dissertations completed between 1990 and 2012 (k = 14). Results demonstrate that interaction in SCMC…

  20. Conversation Analysis of Computer-Mediated Communication

    ERIC Educational Resources Information Center

    Gonzalez-Lloret, Marta

    2011-01-01

    The potential of computer-mediated communication (CMC) for language learning resides mainly in the possibility that learners have to engage with other speakers of the language, including L1 speakers. The inclusion of CMC in the L2 classroom provides an opportunity for students to utilize authentic language in real interaction, rather than the more…

  1. Mediation Training for High School Students.

    ERIC Educational Resources Information Center

    Conflict Resolution Unlimited, Inc., Bellevue, WA.

    Young people need help in learning alternative dispute resolution skills at school. Teaching high school students how to understand conflict and then develop effective ways to deal with it is the purpose of this program. Designed for five 3-hour sessions using two trainers, it is organized around seven major themes: The Mediation Process, Cultural…

  2. Mediators of Preschoolers' Early Mathematics Concepts

    ERIC Educational Resources Information Center

    Berghout Austin, Ann M.; Blevins-Knabe, Belinda; Ota, Carrie; Rowe, Trevor; Knudsen Lindauer, Shelley L.

    2011-01-01

    The purpose of this study was to extend existing research relative to the predictors of early mathematics skills. Using Vygotskian theory as a framework, our primary goal was to determine whether social skills or letter awareness skills served as better mediators between receptive language and early mathematics concepts. The secondary goal was to…

  3. Integrating Computer-Mediated Communication Strategy Instruction

    ERIC Educational Resources Information Center

    McNeil, Levi

    2016-01-01

    Communication strategies (CSs) play important roles in resolving problematic second language interaction and facilitating language learning. While studies in face-to-face contexts demonstrate the benefits of communication strategy instruction (CSI), there have been few attempts to integrate computer-mediated communication and CSI. The study…

  4. 32 CFR 776.38 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mediation, including the advantages and risks involved, and the effect on the attorney-client... little risk of material prejudice to the interests of any of the individuals if the contemplated... individual concerning the decisions to be made and the considerations relevant in making them, so that...

  5. Proteinaceous Molecules Mediating Bifidobacterium-Host Interactions.

    PubMed

    Ruiz, Lorena; Delgado, Susana; Ruas-Madiedo, Patricia; Margolles, Abelardo; Sánchez, Borja

    2016-01-01

    Bifidobacteria are commensal microoganisms found in the gastrointestinal tract. Several strains have been attributed beneficial traits at local and systemic levels, through pathogen exclusion or immune modulation, among other benefits. This has promoted a growing industrial and scientific interest in bifidobacteria as probiotic supplements. However, the molecular mechanisms mediating this cross-talk with the human host remain unknown. High-throughput technologies, from functional genomics to transcriptomics, proteomics, and interactomics coupled to the development of both in vitro and in vivo models to study the dynamics of the intestinal microbiota and their effects on host cells, have eased the identification of key molecules in these interactions. Numerous secreted or surface-associated proteins or peptides have been identified as potential mediators of bifidobacteria-host interactions and molecular cross-talk, directly participating in sensing environmental factors, promoting intestinal colonization, or mediating a dialogue with mucosa-associated immune cells. On the other hand, bifidobacteria induce the production of proteins in the intestine, by epithelial or immune cells, and other gut bacteria, which are key elements in orchestrating interactions among bifidobacteria, gut microbiota, and host cells. This review aims to give a comprehensive overview on proteinaceous molecules described and characterized to date, as mediators of the dynamic interplay between bifidobacteria and the human host, providing a framework to identify knowledge gaps and future research needs. PMID:27536282

  6. Immune-mediated canine and feline keratitis.

    PubMed

    Andrew, Stacy E

    2008-03-01

    Although the normal cornea is devoid of vasculature and lymphatics, there are still several immune-mediated corneal conditions that can occur in dogs and cats. An overview of corneal immunology is presented. Diseases of dogs, including chronic superficial keratitis, superficial punctate keratitis, and canine adenovirus endotheliitis, as well as feline diseases, including eosinophilic keratitis and herpesvirus-related conditions, are discussed.

  7. Community Building and Computer-Mediated Conferencing

    ERIC Educational Resources Information Center

    Moisey, Susan Darlene; Neu, Candace; Cleveland-Innes, Martha

    2008-01-01

    This study examined the relationship between community cohesion and computer-mediated conferencing (CMC), as well as other variables potentially associated with the development of a learning community. Within the context of a graduate-level course in instructional design (a core course in the Masters of Distance Education program at Athabasca…

  8. Proteinaceous Molecules Mediating Bifidobacterium-Host Interactions.

    PubMed

    Ruiz, Lorena; Delgado, Susana; Ruas-Madiedo, Patricia; Margolles, Abelardo; Sánchez, Borja

    2016-01-01

    Bifidobacteria are commensal microoganisms found in the gastrointestinal tract. Several strains have been attributed beneficial traits at local and systemic levels, through pathogen exclusion or immune modulation, among other benefits. This has promoted a growing industrial and scientific interest in bifidobacteria as probiotic supplements. However, the molecular mechanisms mediating this cross-talk with the human host remain unknown. High-throughput technologies, from functional genomics to transcriptomics, proteomics, and interactomics coupled to the development of both in vitro and in vivo models to study the dynamics of the intestinal microbiota and their effects on host cells, have eased the identification of key molecules in these interactions. Numerous secreted or surface-associated proteins or peptides have been identified as potential mediators of bifidobacteria-host interactions and molecular cross-talk, directly participating in sensing environmental factors, promoting intestinal colonization, or mediating a dialogue with mucosa-associated immune cells. On the other hand, bifidobacteria induce the production of proteins in the intestine, by epithelial or immune cells, and other gut bacteria, which are key elements in orchestrating interactions among bifidobacteria, gut microbiota, and host cells. This review aims to give a comprehensive overview on proteinaceous molecules described and characterized to date, as mediators of the dynamic interplay between bifidobacteria and the human host, providing a framework to identify knowledge gaps and future research needs.

  9. 44 CFR 7.942 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Mediation. 7.942 Section 7.942 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND... designated by the Administrator all sufficient complaints that: (1) Fall within the jurisdiction of the...

  10. 7 CFR 205.663 - Mediation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Mediation. 205.663 Section 205.663 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM...

  11. One Teacher's Journey through the Mediated Intersections

    ERIC Educational Resources Information Center

    Beach, Crystal L.

    2015-01-01

    Today's classrooms often have a plethora of new ways of reading and writing entering the room, but too often these new ways of "doing" are disregarded and checked at the door. For this reason, one educator shares her journey through the mediated intersections of media, culture, and education. In this piece, she explores how literacy…

  12. Nutritionally Mediated Oxidative Stress and Inflammation

    PubMed Central

    Muñoz, Alexandra; Costa, Max

    2013-01-01

    There are many sources of nutritionally mediated oxidative stress that trigger inflammatory cascades along short and long time frames. These events are primarily mediated via NFκB. On the short-term scale postprandial inflammation is characterized by an increase in circulating levels of IL-6 and TNF-α and is mirrored on the long-term by proinflammatory gene expression changes in the adipocytes and peripheral blood mononuclear cells (PBMCs) of obese individuals. Specifically the upregulation of CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, CXCL2/MIP-2α, and CXCL3/MIP-2β is noted because these changes have been observed in both adipocytes and PBMC of obese humans. In comparing numerous human intervention studies it is clear that pro-inflammatory and anti-inflammatory consumption choices mediate gene expression in humans adipocytes and peripheral blood mononuclear cells. Arachidonic acid and saturated fatty acids (SFAs) both demonstrate an ability to increase pro-inflammatory IL-8 along with numerous other inflammatory factors including IL-6, TNFα, IL-1β, and CXCL1 for arachidonic acid and IGB2 and CTSS for SFA. Antioxidant rich foods including olive oil, fruits, and vegetables all demonstrate an ability to lower levels of IL-6 in PBMCs. Thus, dietary choices play a complex role in the mediation of unavoidable oxidative stress and can serve to exacerbate or dampen the level of inflammation. PMID:23844276

  13. Peer Mediation and Middle School Students

    ERIC Educational Resources Information Center

    Calbreath, Wes; Crews, Moody E.

    2011-01-01

    With the constant concern over violence in schools, school officials are looking for ways to head off this potential problem and to better assure a safe environment for all students. One way that has become popular is the implementation of peer mediation programs where students assist other students in learning how to deal with conflict through…

  14. 45 CFR 16.18 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... grants dispute, the Board may, within the limitations of its resources, offer persons trained in... 45 Public Welfare 1 2010-10-01 2010-10-01 false Mediation. 16.18 Section 16.18 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURES OF THE DEPARTMENTAL GRANT...

  15. IgE-mediated food hypersensitivity disorders.

    PubMed

    Gotua, M; Lomidze, N; Dolidze, N; Gotua, T

    2008-04-01

    Food allergy has become a serious health concern especially in developed countries in the past two decades. In general population approximately 4-6% of children and 1-3% of adults experience food allergy. The article reviews IgE-mediated food hypersensitivity disorders. Epidemiology, Mechanism, Clinical manifestations, Genetically modified crops (GMOs), Diagnosis, Prevention and Treatment of IgE-mediated food allergies are discussed. The investigations show that over 90% of IgE-mediated food allergies in childhood are caused by: cow's milk, hen's egg, soy, peanuts, tree nuts, wheat, fish and shellfish. Also the causes of food allergy are food additives, genetically modified crops. Risk factors for food-dependent exercise-induced anaphylaxis include asthma and previous allergic reactions to the causative food. Food allergy is one of the most common causes of systematic anaphylaxis and anaphylactoid reactions, with an annual incidence of four cases per million populations and estimated 500 deaths annually. In addition to gastrointestinal symptoms, individuals may experience urticaria, angioedema, atopic dermatitis, oral syndrome, asthma, rhinitis, conjunctivitis, hypotension, shock and cardiac arrhythmias, caused by the massive release of mediators from mast cells and basophiles. Diagnosis of food allergy is based on history, detailed dietary analysis, skin testing, measuring specific IgE in blood serum and challenge tests. Treatment and prevention includes: avoidance diet, application of auto-injectable epinephrine, H1 and H2 antihistamines, corticosteroids, antileukotrienes, prostaglandin synthetase inhibitors, cromolyn sodium, etc.

  16. Strategic Game Moves Mediate Implicit Science Learning

    ERIC Educational Resources Information Center

    Rowe, Elizabeth; Baker, Ryan S.; Asbell-Clarke, Jodi

    2015-01-01

    Educational games have the potential to be innovative forms of learning assessment, by allowing us to not just study their knowledge but the process that takes students to that knowledge. This paper examines the mediating role of players' moves in digital games on changes in their pre-post classroom measures of implicit science learning. We…

  17. Mediated electrochemical oxidation of organic wastes using a Co(III) mediator in a neutral electrolyte

    DOEpatents

    Balazs, G.B.; Lewis, P.R.

    1999-07-06

    An electrochemical cell with a Co(III) mediator and neutral pH anolyte provides efficient destruction of organic and mixed wastes. The organic waste is concentrated in the anolyte reservoir, where the cobalt mediator oxidizes the organics and insoluble radioactive species and is regenerated at the anode until all organics are converted to carbon dioxide and destroyed. The neutral electrolyte is non-corrosive, and thus extends the lifetime of the cell and its components. 2 figs.

  18. Mediated electrochemical oxidation of organic wastes using a Co(III) mediator in a neutral electrolyte

    DOEpatents

    Balazs, G. Bryan; Lewis, Patricia R.

    1999-01-01

    An electrochemical cell with a Co(III) mediator and neutral pH anolyte provides efficient destruction of organic and mixed wastes. The organic waste is concentrated in the anolyte reservoir, where the cobalt mediator oxidizes the organics and insoluble radioactive species and is regenerated at the anode until all organics are converted to carbon dioxide and destroyed. The neutral electrolyte is non-corrosive, and thus extends the lifetime of the cell and its components.

  19. Can Computer-Mediated Interventions Change Theoretical Mediators of Safer Sex? A Meta-Analysis

    ERIC Educational Resources Information Center

    Noar, Seth M.; Pierce, Larson B.; Black, Hulda G.

    2010-01-01

    The purpose of this study was to conduct a meta-analysis of computer-mediated interventions (CMIs) aimed at changing theoretical mediators of safer sex. Meta-analytic aggregation of effect sizes from k = 20 studies indicated that CMIs significantly improved HIV/AIDS knowledge, d = 0.276, p less than 0.001, k = 15, N = 6,625; sexual/condom…

  20. 78 FR 29071 - Assessment of Mediation and Arbitration Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-17

    ...\\ Assessment of Mediation and Arbitration Procedures, 75 FR 52054. \\4\\ Assessment of Mediation and Arbitration... Resolution, 60 FR 19494, 19499-500 (April 19, 1995) (codified at 18 CFR 385.605 (Rule 605)) (describing...

  1. A proposed clinical and biological interpretation of mediated interaction.

    PubMed

    Ikram, M Arfan; VanderWeele, Tyler J

    2015-10-01

    Understanding of causal pathways in epidemiology involves the concepts of direct and indirect effects. Recently, causal mediation analysis has been formalized to quantify these direct and indirect effects in the presence of exposure-mediator interaction and even allows for four-way decomposition of the total effect: controlled direct effect, reference interaction, mediated interaction, pure indirect effect. Whereas the other three effects can be intuitively conceptualized, mediated interaction is often considered a nuisance in statistical analysis. In this paper, we focus on mediated interaction and contrast it against pure mediation. We also propose a clinical and biological interpretation of mediated interaction using three hypothetical examples. With these examples we aim to make researchers aware that mediated interaction can actually provide important clinical and biological information.

  2. The oxysterol-binding protein superfamily: new concepts and old proteins

    PubMed Central

    Villasmil, Michelle L.; Bankaitis, Vytas A.; Mousley, Carl J.

    2013-01-01

    The Kes1 OSBP (oxysterol-binding protein) is a key regulator of membrane trafficking through the TGN (trans-Golgi network) and endosomal membranes. We demonstrated recently that Kes1 acts as a sterol-regulated rheostat for TGN/endosomal phosphatidylinositol 4-phosphate signalling. Kes1 utilizes its dual lipid-binding activities to integrate endosomal lipid metabolism with TORC1 (target of rapamycin complex 1)-dependent proliferative pathways and transcriptional control of nutrient signalling. PMID:22435832

  3. Mediated electrochemical oxidation of organic wastes without electrode separators

    DOEpatents

    Farmer, J.C.; Wang, F.T.; Hickman, R.G.; Lewis, P.R.

    1996-05-14

    An electrochemical cell/electrolyte/mediator combination is described for the efficient destruction of organic contaminants using metal salt mediators in a sulfuric acid electrolyte, wherein the electrodes and mediator are chosen such that hydrogen gas is produced at the cathode and no cell membrane is required. 3 figs.

  4. RESPECT: Gang Mediation at Albuquerque, New Mexico's Washington Middle School.

    ERIC Educational Resources Information Center

    Tabish, Kenneth R.; Orell, Linda Henry

    1996-01-01

    Presents conflict resolution and mediation techniques used to resolve conflicts among rival gangs at Washington Middle School, an inner-city school in Albuquerque, New Mexico. Discusses formal mediation techniques and mediation for both male and female gang members. Focuses on preserving self-respect and dignity for gang members in all conflict…

  5. Prospective and Retrospective Processing in Associative Mediated Priming

    ERIC Educational Resources Information Center

    Jones, Lara L.

    2012-01-01

    Mediated priming refers to the faster word recognition of a target (e.g., milk) following presentation of a prime (e.g., pasture) that is related indirectly via a connecting "mediator" (e.g., cow). Association strength may be an important factor in whether mediated priming occurs prospectively (with target activation prior to its presentation) or…

  6. Conflict Resolution and Peer Mediation: Pathways to Safer Schools.

    ERIC Educational Resources Information Center

    Stomfay-Stitz, Aline M.

    1994-01-01

    Defines conflict resolution and peer mediation and reviews the theoretical base for conflict resolution research. Examines the goals and activities of several peer mediation programs, and discusses the benefits of such programs. Notes that conflict resolution and peer mediation offer feasible opportunities for an entire school community to create…

  7. 40 CFR 7.180 - Mediation of age discrimination complaints.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Mediation of age discrimination... Discrimination Prohibited on the Basis of Age § 7.180 Mediation of age discrimination complaints. (a) The OCR will refer all accepted complaints alleging age discrimination to the Mediation Agency designated...

  8. 40 CFR 7.180 - Mediation of age discrimination complaints.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Mediation of age discrimination... Discrimination Prohibited on the Basis of Age § 7.180 Mediation of age discrimination complaints. (a) The OCR will refer all accepted complaints alleging age discrimination to the Mediation Agency designated...

  9. 40 CFR 7.180 - Mediation of age discrimination complaints.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Mediation of age discrimination... Discrimination Prohibited on the Basis of Age § 7.180 Mediation of age discrimination complaints. (a) The OCR will refer all accepted complaints alleging age discrimination to the Mediation Agency designated...

  10. 40 CFR 7.180 - Mediation of age discrimination complaints.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Mediation of age discrimination... Discrimination Prohibited on the Basis of Age § 7.180 Mediation of age discrimination complaints. (a) The OCR will refer all accepted complaints alleging age discrimination to the Mediation Agency designated...

  11. 40 CFR 7.180 - Mediation of age discrimination complaints.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Mediation of age discrimination... Discrimination Prohibited on the Basis of Age § 7.180 Mediation of age discrimination complaints. (a) The OCR will refer all accepted complaints alleging age discrimination to the Mediation Agency designated...

  12. Cognitive Mediators and Sex-Related Differences in Mathematics

    ERIC Educational Resources Information Center

    Delgado, Ana R.; Prieto, Gerardo

    2004-01-01

    Sex-related differential studies on mathematical abilities have hardly taken into account the mediator role of the verbal factor, which contrasts with the interest shown in the mediator role of visuospatial aptitude. We predicted that if sex-related differences were found, mental rotation would mediate mathematical abilities typically favoring…

  13. Assessing Mediational Models: Testing and Interval Estimation for Indirect Effects

    ERIC Educational Resources Information Center

    Biesanz, Jeremy C.; Falk, Carl F.; Savalei, Victoria

    2010-01-01

    Theoretical models specifying indirect or mediated effects are common in the social sciences. An indirect effect exists when an independent variable's influence on the dependent variable is mediated through an intervening variable. Classic approaches to assessing such mediational hypotheses (Baron & Kenny, 1986; Sobel, 1982) have in recent years…

  14. 29 CFR 1202.2 - Interpretation of mediation agreements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Interpretation of mediation agreements. 1202.2 Section 1202.2 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD RULES OF PROCEDURE § 1202.2 Interpretation of mediation agreements. Under section 5, Second, of title I of the Railway...

  15. 45 CFR 400.83 - Mediation and fair hearings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Mediation and fair hearings. 400.83 Section 400.83... Employment § 400.83 Mediation and fair hearings. (a) Mediation—(1) Public/private RCA program. The State must ensure that a mediation period prior to imposition of sanctions is provided to refugees by...

  16. 15 CFR 930.114 - Secretarial mediation efforts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Secretarial mediation efforts. 930.114... MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Secretarial Mediation § 930.114 Secretarial mediation efforts. (a) Following the close of the hearing, the hearing officer shall transmit...

  17. 15 CFR 930.112 - Request for Secretarial mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Request for Secretarial mediation. 930... RESOURCE MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Secretarial Mediation § 930.112 Request for Secretarial mediation. (a) The Secretary or other head of a Federal agency, or...

  18. 7 CFR 900.103 - Application for mediation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Application for mediation. 900.103 Section 900.103 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... Application for mediation. An application for mediation by a cooperative, shall be in writing and...

  19. The Use of Propensity Scores in Mediation Analysis

    ERIC Educational Resources Information Center

    Jo, Booil; Stuart, Elizabeth A.; MacKinnon, David P.; Vinokur, Amiram D.

    2011-01-01

    Mediation analysis uses measures of hypothesized mediating variables to test theory for how a treatment achieves effects on outcomes and to improve subsequent treatments by identifying the most efficient treatment components. Most current mediation analysis methods rely on untested distributional and functional form assumptions for valid…

  20. 29 CFR 1203.3 - Interpretation of mediation agreements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Interpretation of mediation agreements. 1203.3 Section 1203.3 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD APPLICATIONS FOR SERVICE § 1203.3 Interpretation of mediation agreements. (a) Applications may be filed with the Board's Chief...

  1. Mediation: An Emerging Form of Dispute Resolution on College Campuses.

    ERIC Educational Resources Information Center

    Hayes, James A.; Balogh, Cynthia P.

    1990-01-01

    Surveyed National Association of Student Personnel Administrators member institutions (N=704) to determine existence and characteristics of student affairs mediation programs. Found 29 campuses had established formal mediation programs. Argues that establishing formal mediation programs provides many institutional benefits. (Author/CM)

  2. A Modest Proposal: Mediating IDEA Disputes Without Splitting the Baby.

    ERIC Educational Resources Information Center

    Beyer, Jonathan A.

    1999-01-01

    Recognizes the benefits of mediation for easing special education conflicts, but addresses the inconsistencies and ambiguities created by the 1997 amendments to the Individuals with Disabilities Education Act (IDEA). Recommends that state and local education agencies use mediators certified in sophisticated mediation techniques, schooled in…

  3. Gravity mediated supersymmetry breaking in six dimensions

    NASA Astrophysics Data System (ADS)

    Falkowski, Adam; Lee, Hyun Min; Lüdeling, Christoph

    2005-10-01

    We study gravity mediated supersymmetry breaking in four-dimensional effective theories derived from six-dimensional brane-world supergravity. Using the Noether method we construct a locally supersymmetric action for a bulk-brane system consisting of the minimal six-dimensional supergravity coupled to vector and chiral multiplets located at four-dimensional branes. Couplings of the bulk moduli to the brane are uniquely fixed, in particular, they are flavour universal. We compactify this system on T2/Bbb Z2 and derive the four-dimensional effective supergravity. The tree-level effective Kähler potential is not of the sequestered form, therefore gravity mediation may occur at tree-level. We identify one scenario of moduli stabilization in which the soft scalar masses squared are postive.

  4. Fibronectin mediates mesendodermal cell fate decisions

    PubMed Central

    Cheng, Paul; Andersen, Peter; Hassel, David; Kaynak, Bogac L.; Limphong, Pattraranee; Juergensen, Lonny; Kwon, Chulan; Srivastava, Deepak

    2013-01-01

    Non-cell-autonomous signals often play crucial roles in cell fate decisions during animal development. Reciprocal signaling between endoderm and mesoderm is vital for embryonic development, yet the key signals and mechanisms remain unclear. Here, we show that endodermal cells efficiently promote the emergence of mesodermal cells in the neighboring population through signals containing an essential short-range component. The endoderm-mesoderm interaction promoted precardiac mesoderm formation in mouse embryonic stem cells and involved endodermal production of fibronectin. In vivo, fibronectin deficiency resulted in a dramatic reduction of mesoderm accompanied by endodermal expansion in zebrafish embryos. This event was mediated by regulation of Wnt signaling in mesodermal cells through activation of integrin-β1. Our findings highlight the importance of the extracellular matrix in mediating short-range signals and reveal a novel function of endoderm, involving fibronectin and its downstream signaling cascades, in promoting the emergence of mesoderm. PMID:23715551

  5. Calcium-mediated mechanisms of cystic expansion

    PubMed Central

    Abdul-Majeed, Shakila; Nauli, Surya M.

    2010-01-01

    In this review, we will discuss several well-accepted signaling pathways toward calcium-mediated mechanisms of cystic expansion. The second messenger calcium ion has contributed to a vast diversity of signal transduction pathways. We will dissect calcium signaling as a possible mechanism that contributes to renal cyst formation. Because cytosolic calcium also regulates an array of signaling pathways, we will first discuss cilia-induced calcium fluxes, followed by Wnt signaling that has attributed to much-discussed planar cell polarity. We will then look at the relationship between cytosolic calcium and cAMP as one of the most important aspects of cyst progression. The signaling of cAMP on MAPK and mTOR will also be discussed. We infer that while cilia-induced calcium fluxes may be the initial signaling messenger for various cellular pathways, no single signaling mediator or pathway is implicated exclusively in the progression of the cystic expansion. PMID:20932898

  6. Gaseous mediators in resolution of inflammation.

    PubMed

    Wallace, John L; Ianaro, Angela; Flannigan, Kyle L; Cirino, Giuseppe

    2015-05-01

    There are numerous gaseous substances that can act as signaling molecules, but the best characterized of these are nitric oxide, hydrogen sulfide and carbon monoxide. Each has been shown to play important roles in many physiological and pathophysiological processes. This article is focused on the effects of these gasotransmitters in the context of inflammation. There is considerable overlap in the actions of nitric oxide, hydrogen sulfide and carbon monoxide with respect to inflammation, and these mediators appear to act primarily as anti-inflammatory substances, promoting resolution of inflammatory processes. They also have protective and pro-healing effects in some tissues, such as the gastrointestinal tract and lung. Over the past two decades, significant progress has been made in the development of novel anti-inflammatory and cytoprotective drugs that release of one or more of these gaseous mediators.

  7. Endopeptidase-Mediated Beta Lactam Tolerance

    PubMed Central

    Dörr, Tobias; Davis, Brigid M.; Waldor, Matthew K.

    2015-01-01

    In many bacteria, inhibition of cell wall synthesis leads to cell death and lysis. The pathways and enzymes that mediate cell lysis after exposure to cell wall-acting antibiotics (e.g. beta lactams) are incompletely understood, but the activities of enzymes that degrade the cell wall (‘autolysins’) are thought to be critical. Here, we report that Vibrio cholerae, the cholera pathogen, is tolerant to antibiotics targeting cell wall synthesis. In response to a wide variety of cell wall- acting antibiotics, this pathogen loses its rod shape, indicative of cell wall degradation, and becomes spherical. Genetic analyses revealed that paradoxically, V. cholerae survival via sphere formation required the activity of D,D endopeptidases, enzymes that cleave the cell wall. Other autolysins proved dispensable for this process. Our findings suggest the enzymes that mediate cell wall degradation are critical for determining bacterial cell fate - sphere formation vs. lysis – after treatment with antibiotics that target cell wall synthesis. PMID:25884840

  8. Perspective and prejudice: antecedents and mediating mechanisms.

    PubMed

    Dovidio, John F; ten Vergert, Marleen; Stewart, Tracie L; Gaertner, Samuel L; Johnson, James D; Esses, Victoria M; Riek, Blake M; Pearson, Adam R

    2004-12-01

    The present work investigated mechanisms by which Whites' prejudice toward Blacks can be reduced (Study 1) and explored how creating a common ingroup identity can reduce prejudice by promoting these processes (Study 2). In Study 1, White participants who viewed a videotape depicting examples of racial discrimination and who imagined the victim's feelings showed greater decreases in prejudice toward Blacks than did those in the objective and no instruction conditions. Among the potential mediating affective and cognitive variables examined, reductions in prejudice were mediated primarily by feelings associated with perceived injustice. In Study 2, an intervention designed to increase perceptions of a common group identity before viewing the videotape, reading that a terrorist threat was directed at all Americans versus directed just at White Americans, also reduced prejudice toward Blacks through increases in feelings of injustice. PMID:15536238

  9. Symbiont-mediated functions in insect hosts

    PubMed Central

    Su, Qi; Zhou, Xiaomao; Zhang, Youjun

    2013-01-01

    The bacterial endosymbionts occur in a diverse array of insect species and are usually rely within the vertical transmission from mothers to offspring. In addition to primary symbionts, plant sap-sucking insects may also harbor several diverse secondary symbionts. Bacterial symbionts play a prominent role in insect nutritional ecology by aiding in digestion of food or supplementing nutrients that insect hosts can’t obtain sufficient amounts from a restricted diet of plant phloem. Currently, several other ecologically relevant traits mediated by endosymbionts are being investigated, including defense toward pathogens and parasites, adaption to environment, influences on insect-plant interactions, and impact of population dynamics. Here, we review recent theoretical predictions and experimental observations of these traits mediated by endosymbionts and suggest that clarifying the roles of symbiotic microbes may be important to offer insights for ameliorating pest invasiveness or impact. PMID:23710278

  10. Climate influences parasite-mediated competitive release.

    PubMed

    Larsen, Martin H; Jensen, K Thomas; Mouritsen, Kim N

    2011-09-01

    Parasitism is believed to play an important role in maintaining species diversity, for instance by facilitating coexistence between competing host species. However, the possibility that environmental factors may govern the outcome of parasite-mediated competition has rarely been considered. The closely related amphipods Corophium volutator and Corophium arenarium both serve as second intermediate host for detrimental trematodes. Corophium volutator is the superior competitor of the two, but also suffers from higher mortality when exposed to infective trematode stages. Here, we report parasite-mediated competitive release of C. arenarium in an intertidal habitat, in part triggered by unusually high temperatures linked to the North Atlantic climate oscillation (NAO). The elevated temperatures accelerated the transmission of cercariae from sympatric first intermediate hosts (mud snails) to amphipods, causing a local collapse of the parasite-sensitive C. volutator population and concordant increase in the abundance of the competitively inferior C. arenarium.

  11. Tachykinin receptors mediating airway marcomolecular secretion

    SciTech Connect

    Gentry, S.E. )

    1991-01-01

    Three tachykinin receptor types, termed NK1, NK2, and NK3, can be distinguished by the relative potency of various peptides in eliciting tissue responses. Airway macromolecular secretion is stimulated by the tachykinin substance P (SP). The purposes of this study were to determine the tachykinin receptor subtype responsible for this stimulation, and to examine the possible involvement of other neurotransmitters in mediating this effect. Ferret tracheal explants maintained in organ culture were labeled with {sup 3}H-glucosamine, a precursor of high molecular weight glycoconjugates (HMWG) which are released by airway secretory cells. Secretion of labeled HMWG then was determined in the absence and presence of the tachykinins SP, neurokinin A (NKA), neurokinin B (NKB), physalaemin (PHY), and eledoisin (ELE). To evaluate the possible contribution of other mediators, tachykinin stimulation was examined in the presence of several receptor blockers.

  12. Yeast Oligo-mediated Genome Engineering (YOGE)

    PubMed Central

    DiCarlo, JE; Conley, AJ; Penttilä, M; Jäntti, J; Wang, HH; Church, GM

    2014-01-01

    High-frequency oligonucleotide-directed recombination engineering (recombineering) has enabled rapid modification of several prokaryotic genomes to date. Here, we present a method for oligonucleotide-mediated recombineering in the model eukaryote and industrial production host S. cerevisiae, which we call Yeast Oligo-mediated Genome Engineering (YOGE). Through a combination of overexpression and knockouts of relevant genes and optimization of transformation and oligonucleotide designs, we achieve high gene modification frequencies at levels that only require screening of dozens of cells. We demonstrate the robustness of our approach in three divergent yeast strains, including those involved in industrial production of bio-based chemicals. Furthermore, YOGE can be iteratively executed via cycling to generate genomic libraries up to 105 individuals at each round for diversity generation. YOGE cycling alone, or in combination with phenotypic selections or endonuclease-based negative genotypic selections, can be used to easily generate modified alleles in yeast populations with high frequencies. PMID:24160921

  13. CEACAM1-Mediated Inhibition of Virus Production.

    PubMed

    Vitenshtein, Alon; Weisblum, Yiska; Hauka, Sebastian; Halenius, Anne; Oiknine-Djian, Esther; Tsukerman, Pinchas; Bauman, Yoav; Bar-On, Yotam; Stern-Ginossar, Noam; Enk, Jonatan; Ortenberg, Rona; Tai, Julie; Markel, Gal; Blumberg, Richard S; Hengel, Hartmut; Jonjic, Stipan; Wolf, Dana G; Adler, Heiko; Kammerer, Robert; Mandelboim, Ofer

    2016-06-14

    Cells in our body can induce hundreds of antiviral genes following virus sensing, many of which remain largely uncharacterized. CEACAM1 has been previously shown to be induced by various innate systems; however, the reason for such tight integration to innate sensing systems was not apparent. Here, we show that CEACAM1 is induced following detection of HCMV and influenza viruses by their respective DNA and RNA innate sensors, IFI16 and RIG-I. This induction is mediated by IRF3, which bound to an ISRE element present in the human, but not mouse, CEACAM1 promoter. Furthermore, we demonstrate that, upon induction, CEACAM1 suppresses both HCMV and influenza viruses in an SHP2-dependent process and achieves this broad antiviral efficacy by suppressing mTOR-mediated protein biosynthesis. Finally, we show that CEACAM1 also inhibits viral spread in ex vivo human decidua organ culture. PMID:27264178

  14. Supersymmetry Breaking, Gauge Mediation, and the LHC

    SciTech Connect

    Shih, David

    2015-04-14

    Gauge mediated SUSY breaking (GMSB) is a promising class of supersymmetric models that automatically satisfies the precision constraints. Prior work of Meade, Seiberg and Shih in 2008 established the full, model-independent parameter space of GMSB, which they called "General Gauge Mediation" (GGM). During the first half of 2010-2015, Shih and his collaborators thoroughly explored the parameter space of GGM and established many well-motivated benchmark models for use by the experimentalists at the LHC. Through their work, the current constraints on GGM from LEP, the Tevatron and the LHC were fully elucidated, together with the possible collider signatures of GMSB at the LHC. This ensured that the full discovery potential for GGM could be completely realized at the LHC.

  15. Environmental responses mediated by histone variants.

    PubMed

    Talbert, Paul B; Henikoff, Steven

    2014-11-01

    Fluctuations in the ambient environment can trigger chromatin disruptions, involving replacement of nucleosomes or exchange of their histone subunits. Unlike canonical histones, which are available only during S-phase, replication-independent histone variants are present throughout the cell cycle and are adapted for chromatin repair. The H2A.Z variant mediates responses to environmental perturbations including fluctuations in temperature and seasonal variation. Phosphorylation of histone H2A.X rapidly marks double-strand DNA breaks for chromatin repair, which is mediated by both H2A and H3 histone variants. Other histones are used as weapons in conflicts between parasites and their hosts, which suggests broad involvement of histone variants in environmental responses beyond chromatin repair. PMID:25150594

  16. Membrane-mediated interaction between retroviral capsids

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Nguyen, Toan

    2012-02-01

    A retrovirus is an RNA virus that is replicated through a unique strategy of reverse transcription. Unlike regular enveloped viruses which are assembled inside the host cells, the assembly of retroviral capsids happens right on the cell membrane. During the assembly process, the partially formed capsids deform the membrane, giving rise to an elastic energy. When two such partial capsids approach each other, this elastic energy changes. Or in other words, the two partial capsids interact with each other via the membrane. This membrane mediated interaction between partial capsids plays an important role in the kinetics of the assembly process. In this work, this membrane mediated interaction is calculated both analytically and numerically. It is worth noting that the diferential equation determining the membrane shape in general nonlinear and cannot be solved analytically,except in the linear region of small deformations. And it is exactly the nonlinear regime that is important for the assembly kinetics of retroviruses as it provides a large energy barrier. The theory developed here is applicable to more generic cases of membrane mediated interactions between two membrane-embedded proteins.

  17. Model analysis of fomite mediated influenza transmission.

    PubMed

    Zhao, Jijun; Eisenberg, Joseph E; Spicknall, Ian H; Li, Sheng; Koopman, James S

    2012-01-01

    Fomites involved in influenza transmission are either hand- or droplet-contaminated. We evaluated the interactions of fomite characteristics and human behaviors affecting these routes using an Environmental Infection Transmission System (EITS) model by comparing the basic reproduction numbers (R(0)) for different fomite mediated transmission pathways. Fomites classified as large versus small surface sizes (reflecting high versus low droplet contamination levels) and high versus low touching frequency have important differences. For example, 1) the highly touched large surface fomite (public tables) has the highest transmission potential and generally strongest control measure effects; 2) transmission from droplet-contaminated routes exceed those from hand-contaminated routes except for highly touched small surface fomites such as door knob handles; and 3) covering a cough using the upper arm or using tissues effectively removes virus from the system and thus decreases total fomite transmission. Because covering a cough by hands diverts pathogens from the droplet-fomite route to the hand-fomite route, this has the potential to increase total fomite transmission for highly touched small surface fomites. An improved understanding and more refined data related to fomite mediated transmission routes will help inform intervention strategies for influenza and other pathogens that are mediated through the environment.

  18. Plasmon-mediated syntheses of metallic nanostructures.

    PubMed

    Langille, Mark R; Personick, Michelle L; Mirkin, Chad A

    2013-12-23

    The ability to prepare noble metal nanostructures of a desired composition, size, and shape enables their resulting properties to be exquisitely tailored, which has led to the use of these structures in numerous applications, ranging from medicine to electronics. The prospect of using light to guide nanoparticle reactions is extremely attractive since one can, in principle, regulate particle growth based on the ability of the nanostructures to absorb a specific excitation wavelength. Therefore, using the nature of light, one can generate a homogenous population of product nanoparticles from a heterogeneous starting population. The best example of this is afforded by plasmon-mediated syntheses of metal nanoparticles, which use visible light irradiation and plasmon excitation to drive the chemical reduction of Ag(+) by citrate. Since the initial discovery that Ag triangular prisms could be prepared by the photo-induced conversion of Ag spherical nanoparticles, plasmon-mediated synthesis has become a highly controllable technique for preparing a number of different Ag particles with tight control over shape, as well as a wide variety of Au-Ag bimetallic nanostructures. We discuss the underlying physical and chemical factors that drive structural selection and conclude by outlining some of the important design considerations for controlling particle shape as learned through studies of plasmon-mediated reactions, but applicable to all methods of noble metal nanocrystal synthesis.

  19. Neuroprotective strategies against calpain-mediated neurodegeneration.

    PubMed

    Yildiz-Unal, Aysegul; Korulu, Sirin; Karabay, Arzu

    2015-01-01

    Calpains are calcium-dependent proteolytic enzymes that have deleterious effects on neurons upon their pathological over-activation. According to the results of numerous studies to date, there is no doubt that abnormal calpain activation triggers activation and progression of apoptotic processes in neurodegeneration, leading to neuronal death. Thus, it is very crucial to unravel all the aspects of calpain-mediated neurodegeneration in order to protect neurons through eliminating or at least minimizing its lethal effects. Protecting neurons against calpain-activated apoptosis basically requires developing effective, reliable, and most importantly, therapeutically applicable approaches to succeed. From this aspect, the most significant studies focusing on preventing calpain-mediated neurodegeneration include blocking the N-methyl-d-aspartate (NMDA)-type glutamate receptor activities, which are closely related to calpain activation; directly inhibiting calpain itself via intrinsic or synthetic calpain inhibitors, or inhibiting its downstream processes; and utilizing the neuroprotectant steroid hormone estrogen and its receptors. In this review, the most remarkable neuroprotective strategies for calpain-mediated neurodegeneration are categorized and summarized with respect to their advantages and disadvantages over one another, in terms of their efficiency and applicability as a therapeutic regimen in the treatment of neurodegenerative diseases. PMID:25709452

  20. Bias in Cross-Sectional Analyses of Longitudinal Mediation: Partial and Complete Mediation under an Autoregressive Model

    ERIC Educational Resources Information Center

    Maxwell, Scott E.; Cole, David A.; Mitchell, Melissa A.

    2011-01-01

    Maxwell and Cole (2007) showed that cross-sectional approaches to mediation typically generate substantially biased estimates of longitudinal parameters in the special case of complete mediation. However, their results did not apply to the more typical case of partial mediation. We extend their previous work by showing that substantial bias can…

  1. Deflected Mirage Mediation: A Phenomenological Framework for Generalized Supersymmetry Breaking

    SciTech Connect

    Everett, Lisa L.; Kim, Ian-Woo; Ouyang, Peter; Zurek, Kathryn M.

    2008-09-05

    We present a general phenomenological framework for dialing between gravity mediation, gauge mediation, and anomaly mediation. The approach is motivated from recent developments in moduli stabilization, which suggest that gravity mediated terms can be effectively loop suppressed and thus comparable to gauge and anomaly mediated terms. The gauginos exhibit a mirage unification behavior at a ''deflected'' scale, and gluinos are often the lightest colored sparticles. The approach provides a rich setting in which to explore generalized supersymmetry breaking at the CERN Large Hadron Collider.

  2. Predictors of Parental Mediation Regarding Children's Smartphone Use.

    PubMed

    Hwang, Yoori; Jeong, Se-Hoon

    2015-12-01

    Children's addiction to smartphones has become a serious issue, and parental mediation could help prevent children's problematic use of smartphones. This research examined the factors that predict and explain parents' intention to mediate children's behavior over smartphone use. Based on a survey of 460 parents of elementary school students, we found that parental mediation was predicted by (a) parent's own addiction to smartphones, (b) perceived severity of smartphone addiction, and (c) personality traits such as neuroticism, openness, and agreeableness. To the best of our knowledge, this study is the first to examine the predictors of parental mediation regarding children's smartphone addiction, and the findings suggest some strategies to increase parental mediation. PMID:26544162

  3. Predictors of Parental Mediation Regarding Children's Smartphone Use.

    PubMed

    Hwang, Yoori; Jeong, Se-Hoon

    2015-12-01

    Children's addiction to smartphones has become a serious issue, and parental mediation could help prevent children's problematic use of smartphones. This research examined the factors that predict and explain parents' intention to mediate children's behavior over smartphone use. Based on a survey of 460 parents of elementary school students, we found that parental mediation was predicted by (a) parent's own addiction to smartphones, (b) perceived severity of smartphone addiction, and (c) personality traits such as neuroticism, openness, and agreeableness. To the best of our knowledge, this study is the first to examine the predictors of parental mediation regarding children's smartphone addiction, and the findings suggest some strategies to increase parental mediation.

  4. Plant Mediator complex and its critical functions in transcription regulation.

    PubMed

    Yang, Yan; Li, Ling; Qu, Li-Jia

    2016-02-01

    The Mediator complex is an important component of the eukaryotic transcriptional machinery. As an essential link between transcription factors and RNA polymerase II, the Mediator complex transduces diverse signals to genes involved in different pathways. The plant Mediator complex was recently purified and comprises conserved and specific subunits. It functions in concert with transcription factors to modulate various responses. In this review, we summarize the recent advances in understanding the plant Mediator complex and its diverse roles in plant growth, development, defense, non-coding RNA production, response to abiotic stresses, flowering, genomic stability and metabolic homeostasis. In addition, the transcription factors interacting with the Mediator complex are also highlighted.

  5. Mediator and moderator effects in developmental and behavioral pediatric research.

    PubMed

    Rose, Brigid M; Holmbeck, Grayson N; Coakley, Rachael Millstein; Franks, Elizabeth A

    2004-02-01

    The terms mediation and moderation are defined and clarified with particular emphasis on the role of mediational and moderational analyses in developmental and behavioral pediatric research. The article highlights the applicability of mediational and moderational analyses to longitudinal, intervention, and risk and protective factor research, and it provides basic information about how these analyses might be conducted. Also included is a discussion of various ways that both mediator and moderator variables can be incorporated into a single model. The article concludes with extended examples of both types of analyses using a longitudinal pediatric study for illustration. The article provides recommendations for applying mediational and moderational research in clinical practice.

  6. Docosapentaenoic acid derived metabolites and mediators - The new world of lipid mediator medicine in a nutshell.

    PubMed

    Weylandt, Karsten-H

    2016-08-15

    Recent years have seen the description and elucidation of a new class of anti-inflammatory and pro-resolving lipid mediators. The arachidonic acid (AA)-derived compounds in this class are called lipoxins and have been described in great detail since their discovery thirty years ago. The new players are mediators derived from fish oil omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), called resolvins, protectins and maresins. Taken together, these mediators are also called specialized pro-resolution mediators (SPMs). As compared to the AA/EPA/DHA-derived compounds, research regarding mediators formed from the n-3 and n-6 docosapentaenoic acids (DPAn-3 and DPAn-6) is sparse. However, mono- di- and trihydroxy derivates of the DPAs have anti-inflammatory properties as well, even though mechanisms of their anti-inflammatory action have not been fully elucidated. This review aims to summarize current knowledge regarding the DPA-derived SPMs and their actions. PMID:26546723

  7. Redox-Mediated and Ionizing-Radiation-Induced Inflammatory Mediators in Prostate Cancer Development and Treatment

    PubMed Central

    Miao, Lu; Holley, Aaron K.; Zhao, Yanming; St. Clair, William H.

    2014-01-01

    Abstract Significance: Radiation therapy is widely used for treatment of prostate cancer. Radiation can directly damage biologically important molecules; however, most effects of radiation-mediated cell killing are derived from the generated free radicals that alter cellular redox status. Multiple proinflammatory mediators can also influence redox status in irradiated cells and the surrounding microenvironment, thereby affecting prostate cancer progression and radiotherapy efficiency. Recent Advances: Ionizing radiation (IR)–generated oxidative stress can regulate and be regulated by the production of proinflammatory mediators. Depending on the type and stage of the prostate cancer cells, these proinflammatory mediators may lead to different biological consequences ranging from cell death to development of radioresistance. Critical Issues: Tumors are heterogeneous and dynamic communication occurs between stromal and prostate cancer cells, and complicated redox-regulated mechanisms exist in the tumor microenvironment. Thus, antioxidant and anti-inflammatory strategies should be carefully evaluated for each patient at different stages of the disease to maximize therapeutic benefits while minimizing unintended side effects. Future Directions: Compared with normal cells, tumor cells are usually under higher oxidative stress and secrete more proinflammatory mediators. Thus, redox status is often less adaptive in tumor cells than in their normal counterparts. This difference can be exploited in a search for new cancer therapeutics and treatment regimes that selectively activate cell death pathways in tumor cells with minimal unintended consequences in terms of chemo- and radio-resistance in tumor cells and toxicity in normal tissues. Antioxid. Redox Signal. 20, 1481–1500. PMID:24093432

  8. Tests of Mediation: Paradoxical Decline in Statistical Power as a Function of Mediator Collinearity.

    PubMed

    Beasley, T Mark

    2014-01-01

    Increasing the correlation between the independent variable and the mediator (a coefficient) increases the effect size (ab) for mediation analysis; however, increasing a by definition increases collinearity in mediation models. As a result, the standard error of product tests increase. The variance inflation due to increases in a at some point outweighs the increase of the effect size (ab) and results in a loss of statistical power. This phenomenon also occurs with nonparametric bootstrapping approaches because the variance of the bootstrap distribution of ab approximates the variance expected from normal theory. Both variances increase dramatically when a exceeds the b coefficient, thus explaining the power decline with increases in a. Implications for statistical analysis and applied researchers are discussed. PMID:24954952

  9. Nature of "memory" in T-cell-mediated antibacterial immunity: anamnestic production of mediator T cells.

    PubMed Central

    North, R J

    1975-01-01

    Mice that survived an immunizing infection with Listeria monocytogenes remained specifically resistant to lethal secondary infection for several months. This acquired, long-lived state of resistance was not dependent on activated macrophages that remained after the primary response. It depended, instead, on an acquired long-lived capacity on the part of immunized mice for generating mediator T cells faster and in larger numbers than normal mice. The number of mediator T cells generated in response to secondary infection was proportional to the level of infection. The results suggest that the accelerated production of mediator T cells that occurs in response to secondary infection represents the expression of a state of immunological T-cell memory. PMID:811558

  10. CNS Dopamine Transmission Mediated by Noradrenergic Innervation

    PubMed Central

    Smith, Caroline C.; Greene, Robert W.

    2012-01-01

    The pre-synaptic source of dopamine in the CA1 field of dorsal hippocampus is uncertain due to an anatomical mismatch between dopaminergic terminals and receptors. We show, in an in vitro slice preparation from C57BL6 male mice, that a dopamine (DA) D1 receptor (D1R) mediated enhancement in glutamate synaptic transmission occurs following release of endogenous DA with amphetamine exposure. It is assumed DA is released from terminals innervating from the ventral tegmental area (VTA) even though DA transporter (DAT) positive fibers are absent in hippocampus, a region with abundant D1Rs. It has been suggested this results from a lack of DAT expression on VTA terminals rather than a lack of these terminals per se. Neither a knockdown of tyrosine hydroxylase (TH) expression in the VTA by THsiRNA, delivered locally, by adeno-associated viral vector, nor localized pharmacological blockade of DAT to prevent amphetamine uptake into DA terminals, has any effect on the D1R synaptic, enhancement response to amphetamine. However, either a decrease in TH expression in the locus coeruleus (LC) or a blockade of the norepinephrine (NE) transporter prevents the DA mediated response, indicating LC terminals can release both NE and DA. These findings suggest noradrenergic fibers may be the primary source of DA release in hippocampus and corresponding DA mediated increase in synaptic transmission. Accordingly, these data imply the LC may have a role in DA transmission in the CNS in response to drugs of abuse, and potentially, under physiological conditions. PMID:22553014

  11. Inflammatory mediators in mastitis and lactation insufficiency.

    PubMed

    Ingman, Wendy V; Glynn, Danielle J; Hutchinson, Mark R

    2014-07-01

    Mastitis is a common inflammatory disease during lactation that causes reduced milk supply. A growing body of evidence challenges the central role of pathogenic bacteria in mastitis, with disease severity associated with markers of inflammation rather than infection. Inflammation in the mammary gland may be triggered by microbe-associated molecular patterns (MAMPs) as well as danger-associated molecular patterns (DAMPs) binding to pattern recognition receptors such as the toll-like receptors (TLRs) on the surface of mammary epithelial cells and local immune cell populations. Activation of the TLR4 signalling pathway and downstream nuclear factor kappa B (NFkB) is critical to mediating local mammary gland inflammation and systemic immune responses in mouse models of mastitis. However, activation of NFkB also induces epithelial cell apoptosis and reduced milk protein synthesis, suggesting that inflammatory mediators activated during mastitis promote partial involution. Perturbed milk flow, maternal stress and genetic predisposition are significant risk factors for mastitis, and could lead to a heightened TLR4-mediated inflammatory response, resulting in increased susceptibility and severity of mastitis disease in the context of low MAMP abundance. Therefore, heightened host inflammatory signalling may act in concert with pathogenic or commensal bacterial species to cause both the inflammation associated with mastitis and lactation insufficiency. Here, we present an alternate paradigm to the widely held notion that breast inflammation is driven principally by infectious bacterial pathogens, and suggest there may be other therapeutic strategies, apart from the currently utilised antimicrobial agents, that could be employed to prevent and treat mastitis in women.

  12. Tear Mediators in Corneal Ectatic Disorders

    PubMed Central

    Pásztor, Dorottya; Kolozsvári, Bence Lajos; Csutak, Adrienne; Berta, András; Hassan, Ziad; Ujhelyi, Bernadett; Gogolák, Péter; Fodor, Mariann

    2016-01-01

    Purpose To compare the concentrations of 11 tear mediators in order to reveal the biochemical difference between pellucid marginal degeneration (PMD) and keratoconus (KC). Methods We have designed a cross-sectional study in which patients with corneal ectasia based on slit-lamp biomicroscopy and Pentacam HR (keratometry values (K1, K2, Kmax), astigmatism, minimal radius of curvature (Rmin), corneal thickness (Apex and Min), indices (surface variation, vertical asymmetry, keratoconus, central keratoconus, height asymmetry and decentration)) were enrolled. Eyes of keratoconic patients were similar to the PMD patients in age and severity (K2, Kmax and Rmin). Non-stimulated tear samples were collected from nine eyes of seven PMD patients, 55 eyes of 55 KC patients and 24 eyes of 24 healthy controls. The mediators’ (interleukin -6, -10, chemokine ligand 5, -8, -10, matrix metalloproteinase (MMP) -9, -13, tissue inhibitor of metalloproteinases (TIMP)-1, tissue plasminogen activator, plasminogen activator inhibitor, nerve growth factor) concentrations were measured using Cytometric Bead Array. Results MMP-9 was the only mediator which presented relevant variances between the two patient groups (p = 0.005). The ratios of MMP-9 and TIMP-1 were 2.45, 0.40 and 0.23 in PMD, KC and the controls, respectively. Conclusion As far as we are aware, this is the first study that aims to reveal the biochemical differences between PMD and KC. Further studies of biomarkers to investigate the precise role of these mediators need to be defined, and it is important to confirm the observed changes in a larger study to gain further insights into the molecular alterations in PMD. PMID:27074131

  13. Natural supersymmetric spectrum in mirage mediation

    NASA Astrophysics Data System (ADS)

    Asano, Masaki; Higaki, Tetsutaro

    2012-08-01

    The current results of LHC experiments exclude a large area of the light new particle region, namely, natural parameter space, in supersymmetric extension models. One of the possibilities for achieving the correct electroweak symmetry breaking naturally is the low-scale messenger scenario. Actually, the next-to-minimal supersymmetric standard model with TeV scale mirage mediation realizes the natural electroweak symmetry breaking with various mass spectra. In this paper, we show the possible mass spectrum in the scenario, e.g., the degenerate and/or hierarchical mass spectrum, and discuss these features.

  14. Electroweak naturalness and deflected mirage mediation

    NASA Astrophysics Data System (ADS)

    Barger, Vernon; Everett, Lisa L.; Garon, Todd S.

    2016-04-01

    We investigate the question of electroweak naturalness within the deflected mirage mediation (DMM) framework for supersymmetry breaking in the minimal supersymmetric standard model. The class of DMM models considered are nine-parameter theories that fall within the general classification of the 19-parameter phenomenological minimal supersymmetric standard model. Our results show that these DMM models have regions of parameter space with very low electroweak fine-tuning, at levels comparable to the phenomenological minimal supersymmetric standard model. These parameter regions should be probed extensively in the current LHC run.

  15. Dark matter signals in deflected mirage mediation

    SciTech Connect

    Holmes, Michael

    2010-02-10

    We investigate the parameter space of a specific class of model within the deflected mirage mediation (DMM) scenario. We look at neutralino properties and compute the thermal relic density as well as interaction rates with xenon direct detection experiments. We find that there are portions of the parameter space which are in line with the current WMAP constraints. Further we find that none of the investigated parameter space is in conflict with current bounds from the Xenon10 experiment and that future large-scale liquid xenon experiments will probe a large portion of the model space.

  16. Microwave-mediated enzymatic modifications of DNA.

    PubMed

    Das, Rakha Hari; Ahirwar, Rajesh; Kumar, Saroj; Nahar, Pradip

    2015-02-15

    Here we report microwave-induced specific cleavage, ligation, dephosphorylation, and phosphorylation of nucleic acids catalyzed by restriction endonucleases, T4 DNA ligase, T4 polynucleotide kinase, and calf intestinal alkaline phosphatase. The microwave-mediated method has dramatically reduced the reaction time to 20 to 50s. In control experiments, the same reactions failed to give the desired reaction products when carried out in the same time periods but without microwave irradiation. Because the microwave method is rapid, it could be a useful alternative to the time-consuming conventional procedure for enzymatic modification of DNA. PMID:25447491

  17. Possible mediators of the ``living'' radical polymerization

    NASA Astrophysics Data System (ADS)

    Motyakin, M. V.; Wasserman, A. M.; Stott, P. E.; Zaikov, G. E.

    2006-03-01

    The stable radicals derived from different compounds were detected in process of styrene autopolymerization. The nitroxide radicals are produced from nitrosocompound, hindered hydroxylamine, nitrophenols and nitroanisoles. The phenoxyl radicals are formed from quinine methides, and naphtoxyl radicals are generated from 2-nitro-1-naphtol. The radicals are identified, the kinetics of their formation and follow-up evolution are studied. These radicals can participate in process of living radical polymerization as the mediators and can effect significantly on kinetics of polymerization and structure of the resulting polymer.

  18. Electride Mediated Surface Enhanced Raman Scattering (SERS)

    NASA Technical Reports Server (NTRS)

    Anderson, Mark S. (Inventor)

    2016-01-01

    An electride may provide surface enhanced Raman scattering (SERS). The electride, a compound where the electrons serve as anions, may be a ceramic electride, such as a conductive ceramic derived from mayenite, or an organic electride, for example. The textured electride surface or electride particles may strongly enhance the Raman scattering of organic or other Raman active analytes. This may also provide a sensitive method for monitoring the chemistry and electronic environment at the electride surface. The results are evidence of a new class of polariton (i.e., a surface electride-polariton resonance mechanism) that is analogous to the surface plasmon-polariton resonance that mediates conventional SERS.

  19. PEROXIDASE-MEDIATED MAMMALIAN CELL CYTOTOXICITY

    PubMed Central

    Edelson, Paul J.; Cohn, Zanvil A.

    1973-01-01

    Lactoperoxidase, in the presence of hydrogen peroxide and iodide is cytotoxic for human and mouse lymphoid cells, and human erythrocytes. Myeloperoxidase, in amounts equivalent to 1.5 x 106 neutrophils, readily replaces lactoperoxidase, and allows the substitution of the iodide ion by chloride. The myeloperoxidase-mediated reaction is rapid, and highly efficient, leading to 85–90% cell death in 90 min, as measured by 51chromium release and dye exclusion. The mixture of granulocytes. monocytes, and lymphocytes present in an inflammatory exudate, and the intimate cell-to-cell association characteristic of cytotoxic phenomena may provide the in vivo requirements for such a system. PMID:4717124

  20. Gene transfer mediated by alpha2-macroglobulin.

    PubMed Central

    Schneider, H; Huse, K; Birkenmeier, G; Otto, A; Scholz, G H

    1996-01-01

    alpha2-Macroglobulin covalently linked to poly(L)-lysine can be used as a vehicle for receptor-mediated gene transfer. This modified alpha2-macroglobulin maintains its ability to bind to the alpha2-macroglobulin receptor, and was shown to introduce a luciferase reporter gene plasmid into HepG2 human hepatoma cells in vitro. The alpha2-macroglobulin receptor is a very large and multifunctional cell surface receptor, whose rapid and efficient internalization rate makes it attractive for gene therapy, e.g. for hepatic gene targeting via injection into the portal vein. PMID:8871570

  1. Flux-mediated diffuse mismatch model

    NASA Astrophysics Data System (ADS)

    Loh, G. C.; Tay, B. K.; Teo, E. H. T.

    2010-09-01

    The diffuse mismatch model (DMM) is modified to account for the effect of thermal flux on phonon transmission at interfaces. This new model, the flux-mediated diffuse mismatch model (FMDMM) takes a slightly different approach in its formulation, and does not employ the principle of detailed balance. Two competing processes—an increase in the flux coefficient, and a decrease in the rest of the transmission term, may result in either a rise or fall in thermal boundary resistance when thermal flux is increased. This might partially explain the large disparities between experimental, theoretical, and simulated results of thermal boundary resistance.

  2. Cold agglutinin-mediated autoimmune hemolytic anemia.

    PubMed

    Berentsen, Sigbjørn; Randen, Ulla; Tjønnfjord, Geir E

    2015-06-01

    Cold antibody types account for about 25% of autoimmune hemolytic anemias. Primary chronic cold agglutinin disease (CAD) is characterized by a clonal lymphoproliferative disorder. Secondary cold agglutinin syndrome (CAS) complicates specific infections and malignancies. Hemolysis in CAD and CAS is mediated by the classical complement pathway and is predominantly extravascular. Not all patients require treatment. Successful CAD therapy targets the pathogenic B-cell clone. Complement modulation seems promising in both CAD and CAS. Further development and documentation are necessary before clinical use. We review options for possible complement-directed therapy.

  3. Agrobacterium-mediated transformation: rice transformation.

    PubMed

    Slamet-Loedin, Inez H; Chadha-Mohanty, Prabhjit; Torrizo, Lina

    2014-01-01

    Agrobacterium is a common soil bacterium with natural capacity for trans-kingdom transfer of genetic information by transferring its T-DNA into the eukaryotic genome. In agricultural plant biotechnology, combination of non-phytopathogenic strain of Agrobacterium tumefaciens with modified T-DNA and vir-genes in a binary vector system is the most widely utilized system for genetic improvement in diverse plant species and for gene function validation. Here we have described a highly efficient A. tumefaciens-mediated transformation system for indica and japonica rice cultivars based on an immature embryo system.

  4. Ubiquitin-Mediated Degradation of Aurora Kinases

    PubMed Central

    Lindon, Catherine; Grant, Rhys; Min, Mingwei

    2016-01-01

    The Aurora kinases are essential regulators of mitosis in eukaryotes. In somatic cell divisions of higher eukaryotes, the paralogs Aurora kinase A (AurA) and Aurora kinase B (AurB) play non-overlapping roles that depend on their distinct spatiotemporal activities. These mitotic roles of Aurora kinases depend on their interactions with different partners that direct them to different mitotic destinations and different substrates: AurB is a component of the chromosome passenger complex that orchestrates the tasks of chromosome segregation and cytokinesis, while AurA has many known binding partners and mitotic roles, including a well-characterized interaction with TPX2 that mediates its role in mitotic spindle assembly. Beyond the spatial control conferred by different binding partners, Aurora kinases are subject to temporal control of their activation and inactivation. Ubiquitin-mediated proteolysis is a critical route to irreversible inactivation of these kinases, which must occur for ordered transition from mitosis back to interphase. Both AurA and AurB undergo targeted proteolysis after anaphase onset as substrates of the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase, even while they continue to regulate steps during mitotic exit. Temporal control of Aurora kinase destruction ensures that AurB remains active at the midbody during cytokinesis long after AurA activity has been largely eliminated from the cell. Differential destruction of Aurora kinases is achieved despite the fact that they are targeted at the same time and by the same ubiquitin ligase, making these substrates an interesting case study for investigating molecular determinants of ubiquitin-mediated proteolysis in higher eukaryotes. The prevalence of Aurora overexpression in cancers and their potential as therapeutic targets add importance to the task of understanding the molecular determinants of Aurora kinase stability. Here, we review what is known about ubiquitin-mediated targeting

  5. Mediation in Special Education: A Resource Manual for Mediators. Revised and Updated.

    ERIC Educational Resources Information Center

    Schrag, Judy A.

    This resource manual presents information on mediation practices in special education disagreements between the school and parents. The manual provides an overview of requirements in the Individuals with Disabilities Education Act (IDEA) and gives definitions for alternative dispute resolution processes, such as arbitration and litigation. A chart…

  6. Immune mediators of chronic pelvic pain syndrome

    PubMed Central

    Murphy, Stephen F.; Schaeffer, Anthony J.; Thumbikat, Praveen

    2016-01-01

    The cause of chronic pelvic pain syndrome (CPPS) has yet to be established. Since the late 1980s, cytokine, chemokine, and immunological classification studies using human samples have focused on identifying biomarkers for CPPS, but no diagnostically beneficial biomarkers have been identified, and these studies have done little to deepen our understanding of the mechanisms underlying chronic prostatic pain. Given the large number of men thought to be affected by this condition and the ineffective nature of current treatments, there is a pressing need to elucidate these mechanisms. Prostatitis types IIIa and IIIb are classified according to the presence of pain without concurrent presence of bacteria; however, it is becoming more evident that, although levels of bacteria are not directly associated with levels of pain, the presence of bacteria might act as the initiating factor that drives primary activation of mast-cell-mediated inflammation in the prostate. Mast cell activation is also known to suppress regulatory T cell (Treg) control of self-tolerance and also activate neural sensitization. This combination of established autoimmunity coupled with peripheral and central neural sensitization can result in the development of multiple symptoms, including pelvic pain and bladder irritation. Identifying these mechanisms as central mediators in CPPS offers new insight into the prospective treatment of the disease. PMID:24686526

  7. Ultrasound-mediated nail drug delivery system.

    PubMed

    Abadi, Danielle; Zderic, Vesna

    2011-12-01

    A novel ultrasound-mediated drug delivery system has been developed for treatment of a nail fungal disorder (onychomycosis) by improving delivery to the nail bed using ultrasound to increase the permeability of the nail. The slip-in device consists of ultrasound transducers and drug delivery compartments above each toenail. The device is connected to a computer, where a software interface allows users to select their preferred course of treatment. In in vitro testing, canine nails were exposed to 3 energy levels (acoustic power of 1.2 W and exposure durations of 30, 60, and 120 seconds). A stereo -microscope was used to determine how much of a drug-mimicking compound was delivered through the nail layers by measuring brightness on the cross section of each nail tested at each condition, where brightness level decreases coincide with increases in permeability. Each of the 3 energy levels tested showed statistical significance when compared to the control (P < .05) with a permeability factor of 1.3 after 30 seconds of exposure, 1.3 after 60 seconds, and 1.5 after 120 seconds, where a permeability factor of 1 shows no increase in permeability. Current treatments for onychomycosis include systemic, topical, and surgical. Even when used all together, these treatments typically take a long time to result in nail healing, thus making this ultrasound-mediated device a promising alternative. PMID:22124008

  8. Ultrasound-Mediated Polymeric Micelle Drug Delivery.

    PubMed

    Xia, Hesheng; Zhao, Yue; Tong, Rui

    2016-01-01

    The synthesis of multi-functional nanocarriers and the design of new stimuli-responsive means are equally important for drug delivery. Ultrasound can be used as a remote, non-invasive and controllable trigger for the stimuli-responsive release of nanocarriers. Polymeric micelles are one kind of potential drug nanocarrier. By combining ultrasound and polymeric micelles, a new modality (i.e., ultrasound-mediated polymeric micelle drug delivery) has been developed and has recently received increasing attention. A major challenge remaining in developing ultrasound-responsive polymeric micelles is the improvement of the sensitivity or responsiveness of polymeric micelles to ultrasound. This chapter reviews the recent advance in this field. In order to understand the interaction mechanism between ultrasound stimulus and polymeric micelles, ultrasound effects, such as thermal effect, cavitation effect, ultrasound sonochemistry (including ultrasonic degradation, ultrasound-initiated polymerization, ultrasonic in-situ polymerization and ultrasound site-specific degradation), as well as basic micellar knowledge are introduced. Ultrasound-mediated polymeric micelle drug delivery has been classified into two main streams based on the different interaction mechanism between ultrasound and polymeric micelles; one is based on the ultrasound-induced physical disruption of the micelle and reversible release of payload. The other is based on micellar ultrasound mechanochemical disruption and irreversible release of payload.

  9. Histone chaperone-mediated nucleosome assembly process.

    PubMed

    Fan, Hsiu-Fang; Liu, Zi-Ning; Chow, Sih-Yao; Lu, Yi-Han; Li, Hsin

    2015-01-01

    A huge amount of information is stored in genomic DNA and this stored information resides inside the nucleus with the aid of chromosomal condensation factors. It has been reported that the repeat nucleosome core particle (NCP) consists of 147-bp of DNA and two copies of H2A, H2B, H3 and H4. Regulation of chromosomal structure is important to many processes inside the cell. In vivo, a group of histone chaperones facilitate and regulate nucleosome assembly. How NCPs are constructed with the aid of histone chaperones remains unclear. In this study, the histone chaperone-mediated nucleosome assembly process was investigated using single-molecule tethered particle motion (TPM) experiments. It was found that Asf1 is able to exert more influence than Nap1 and poly glutamate acid (PGA) on the nucleosome formation process, which highlights Asf1's specific role in tetrasome formation. Thermodynamic parameters supported a model whereby energetically favored nucleosomal complexes compete with non-nucleosomal complexes. In addition, our kinetic findings propose the model that histone chaperones mediate nucleosome assembly along a path that leads to enthalpy-favored products with free histones as reaction substrates. PMID:25611318

  10. Histone Chaperone-Mediated Nucleosome Assembly Process

    PubMed Central

    Fan, Hsiu-Fang; Liu, Zi-Ning; Chow, Sih-Yao; Lu, Yi-Han; Li, Hsin

    2015-01-01

    A huge amount of information is stored in genomic DNA and this stored information resides inside the nucleus with the aid of chromosomal condensation factors. It has been reported that the repeat nucleosome core particle (NCP) consists of 147-bp of DNA and two copies of H2A, H2B, H3 and H4. Regulation of chromosomal structure is important to many processes inside the cell. In vivo, a group of histone chaperones facilitate and regulate nucleosome assembly. How NCPs are constructed with the aid of histone chaperones remains unclear. In this study, the histone chaperone-mediated nucleosome assembly process was investigated using single-molecule tethered particle motion (TPM) experiments. It was found that Asf1 is able to exert more influence than Nap1 and poly glutamate acid (PGA) on the nucleosome formation process, which highlights Asf1’s specific role in tetrasome formation. Thermodynamic parameters supported a model whereby energetically favored nucleosomal complexes compete with non-nucleosomal complexes. In addition, our kinetic findings propose the model that histone chaperones mediate nucleosome assembly along a path that leads to enthalpy-favored products with free histones as reaction substrates. PMID:25611318

  11. Autophagy mediates degradation of nuclear lamina

    PubMed Central

    Dou, Zhixun; Xu, Caiyue; Donahue, Greg; Shimi, Takeshi; Pan, Ji-An; Zhu, Jiajun; Ivanov, Andrejs; Capell, Brian C.; Drake, Adam M.; Shah, Parisha P.; Catanzaro, Joseph M.; Ricketts, M. Daniel; Lamark, Trond; Adam, Stephen A.; Marmorstein, Ronen; Zong, Wei-Xing; Johansen, Terje; Goldman, Robert D.; Adams, Peter D.; Berger, Shelley L.

    2015-01-01

    Macroautophagy (hereafter referred to as autophagy) is a catabolic membrane trafficking process that degrades a variety of cellular constituents, and is associated with human diseases1–3. While extensive studies have focused on autophagic turnover of cytoplasmic materials, little is known regarding the role of autophagy in degrading nuclear components. Here we report that the autophagy machinery mediates degradation of nuclear lamina components in mammals. The autophagy protein LC3/Atg8, which is involved in autophagy membrane trafficking and substrate delivery4–6, is present in the nucleus and directly interacts with the nuclear lamina protein Lamin B1, and binds to lamin-associated domains (LADs) on chromatin. This LC3-Lamin B1 interaction does not downregulate Lamin B1 during starvation, but mediates its degradation upon oncogenic insults, such as by activated Ras. Lamin B1 degradation is achieved by nucleus-to-cytoplasm transport that delivers Lamin B1 to the lysosome. Inhibiting autophagy or the LC3-Lamin B1 interaction prevents activated Ras-induced Lamin B1 loss and attenuates oncogene-induced senescence in primary human cells. Our study suggests this new function of autophagy as a guarding mechanism protecting cells from tumorigenesis. PMID:26524528

  12. Plasmid-mediated mineralization of 4-chlorobiphenyl.

    PubMed Central

    Shields, M S; Hooper, S W; Sayler, G S

    1985-01-01

    Strains of Alcaligenes and Acinetobacter spp. were isolated from a mixed culture already proven to be proficient at complete mineralization of monohalogenated biphenyls. These strains were shown to harbor a 35 X 10(6)-dalton plasmid mediating a complete pathway for 4-chlorobiphenyl (4CB) oxidation. Subsequent plasmid curing of these bacteria resulted in the abolishment of the 4CB mineralization phenotype and loss of even early 4CB metabolism by Acinetobacter spp. Reestablishment of the Alcaligenes plasmid, denoted pSS50, in the cured Acinetobacter spp. via filter surface mating resulted in the restoration of 4CB mineralization abilities. 4CB mineralization, however, proved to be an unstable characteristic in some subcultured strains. Such loss was not found to coincide with any detectable alteration in plasmid size. Cultures capable of complete mineralization, as well as those limited to partial metabolism of 4CB, produced 4-chlorobenzoate as a metabolite. Demonstration of mineralization of a purified 14C-labeled chlorobenzoate showed it to be a true intermediate in 4CB mineralization. Unlike the mineralization capability, the ability to produce a metabolite has proven to be stable on subculture. These results indicate the occurrence of a novel plasmid, or evolved catabolic plasmid, that mediates the complete mineralization of 4CB. Images PMID:2993249

  13. LHC Signals of Pure Gravity Mediation

    NASA Astrophysics Data System (ADS)

    Feldstein, Brian

    2013-05-01

    Evidence is mounting that natural supersymmetry at the weak scale is not realized in nature. This evidence comes from collider searches, a lack of new flavor changing neutral current effects, and now also the size of the measured Higgs mass. On the other hand, string theory suggests that supersymmetry might be present at some energy scale, and gauge coupling unification and dark matter imply that that energy scale may be relatively low. The simplest model to address all of these hints is arguably "pure gravity mediation", in which the scalar superpartner masses are taken to be perhaps 100 TeV, with gauginos automatically acquiring loop factor suppressed masses of order TeV. The gauginos might then be the only superpartners accessible to the LHC. Unification and LSP dark matter are maintained (with a wino LSP) at the cost of a 10-5 or 10-6 fine tuning. Here I will discuss the structure and LHC phenomenology of pure gravity mediation.

  14. Light Higgsinos in pure gravity mediation

    NASA Astrophysics Data System (ADS)

    Evans, Jason L.; Ibe, Masahiro; Olive, Keith A.; Yanagida, Tsutomu T.

    2015-03-01

    Pure gravity mediation, with two free parameters, is a minimalistic approach to supergravity models, yet it is capable of incorporating radiative electroweak symmetry breaking, a Higgs mass in agreement with the experimental measurement, without violating any phenomenological constraints. The model may also contain a viable dark matter candidate in the form of a wino. Here, we extend the minimal model by allowing the μ term to be a free parameter equivalent to allowing the two Higgs soft masses, m1 and m2, to differ from other scalar masses, which are set by the gravitino mass. In particular, we examine the region of parameter space where μ ≪m3 /2, in which case the Higgsino becomes the lightest supersymmetric particle and a dark matter candidate. We also consider a generalization of pure gravity mediation that incorporates a Peccei-Quinn symmetry which determines the μ term dynamically. In this case we show that the dark matter may either be in the form of an axion and/or a neutralino and that the lightest supersymmetric particle may be either a wino, bino, or Higgsino.

  15. Histone chaperone-mediated nucleosome assembly process.

    PubMed

    Fan, Hsiu-Fang; Liu, Zi-Ning; Chow, Sih-Yao; Lu, Yi-Han; Li, Hsin

    2015-01-01

    A huge amount of information is stored in genomic DNA and this stored information resides inside the nucleus with the aid of chromosomal condensation factors. It has been reported that the repeat nucleosome core particle (NCP) consists of 147-bp of DNA and two copies of H2A, H2B, H3 and H4. Regulation of chromosomal structure is important to many processes inside the cell. In vivo, a group of histone chaperones facilitate and regulate nucleosome assembly. How NCPs are constructed with the aid of histone chaperones remains unclear. In this study, the histone chaperone-mediated nucleosome assembly process was investigated using single-molecule tethered particle motion (TPM) experiments. It was found that Asf1 is able to exert more influence than Nap1 and poly glutamate acid (PGA) on the nucleosome formation process, which highlights Asf1's specific role in tetrasome formation. Thermodynamic parameters supported a model whereby energetically favored nucleosomal complexes compete with non-nucleosomal complexes. In addition, our kinetic findings propose the model that histone chaperones mediate nucleosome assembly along a path that leads to enthalpy-favored products with free histones as reaction substrates.

  16. Agrobacterium-mediated transformation of Fusarium proliferatum.

    PubMed

    Bernardi-Wenzel, J; Quecine, M C; Azevedo, J L; Pamphile, J A

    2016-01-01

    Fusarium proliferatum is an important pathogen that is associated with plant diseases and primarily affects aerial plant parts by producing different mycotoxins, which are toxic to humans and animals. Within the last decade, this fungus has also been described as one of the causes of red root rot or sudden death syndrome in soybean, which causes extensive damage to this crop. This study describes the Agrobacterium tumefaciens-mediated transformation of F. proliferatum as a tool for the disruption of pathogenicity genes. The genetic transformation was performed using two binary vectors (pCAMDsRed and pFAT-GFP) containing the hph (hygromycin B resistance) gene as a selection marker and red and green fluorescence, respectively. The presence of acetosyringone and the use of filter paper or nitrocellulose membrane were evaluated for their effect on the transformation efficiency. A mean processing rate of 94% was obtained with 96 h of co-cultivation only in the presence of acetosyringone and the use of filter paper or nitrocellulose membrane did not affect the transformation process. Hygromycin B resistance and the presence of the hph gene were confirmed by PCR, and fluorescence due to the expression of GFP and DsRed protein was monitored in the transformants. A high rate of mitotic stability (95%) was observed. The efficiency of Agrobacterium-mediated transformation of F. proliferatum allows the technique to be used for random insertional mutagenesis studies and to analyze fungal genes involved in the infection process. PMID:27323127

  17. Oxytocin mediates social neuroprotection after cerebral ischemia

    PubMed Central

    Karelina, Kate; Stuller, Kathleen A.; Jarrett, Brant; Zhang, Ning; Wells, Jackie; Norman, Greg J.; DeVries, A. Courtney

    2011-01-01

    Background and Purpose The reduced incidence, morbidity and mortality of stroke among humans with strong social support have been well-documented; however, the mechanisms underlying this socially mediated phenomenon remain unknown, but may involve oxytocin (OT), a hormone that modulates some aspects of social behavior in humans and other animals. Methods In the present study, adult male mice were socially isolated (housed individually) or socially paired (housed with an ovariectomized female); social pairing increased hypothalamic OT gene expression. To determine whether a causal relationship exists between increased OT and improved stroke outcome, mice were treated with exogenous OT or OT receptor antagonist (OTA) beginning one week prior to induction of experimental stroke via middle cerebral artery occlusion (MCAO). Results Relative to social isolation, social housing attenuated infarct size, neuroinflammation, and oxidative stress following experimental stroke; the neuroprotective effect of social housing was eliminated by OTA treatment. In contrast, administration of OT to socially isolated mice reproduced the neuroprotection conferred by social housing. We further report evidence for a direct suppressive action of OT on cultured microglia, which is a key instigator in the development of neuroinflammation after cerebral ischemia. Conclusions These findings support the hypothesis that OT mediates the neuroprotective effect of social interaction on stroke outcome. PMID:21960564

  18. Ultrasound-mediated nail drug delivery system.

    PubMed

    Abadi, Danielle; Zderic, Vesna

    2011-12-01

    A novel ultrasound-mediated drug delivery system has been developed for treatment of a nail fungal disorder (onychomycosis) by improving delivery to the nail bed using ultrasound to increase the permeability of the nail. The slip-in device consists of ultrasound transducers and drug delivery compartments above each toenail. The device is connected to a computer, where a software interface allows users to select their preferred course of treatment. In in vitro testing, canine nails were exposed to 3 energy levels (acoustic power of 1.2 W and exposure durations of 30, 60, and 120 seconds). A stereo -microscope was used to determine how much of a drug-mimicking compound was delivered through the nail layers by measuring brightness on the cross section of each nail tested at each condition, where brightness level decreases coincide with increases in permeability. Each of the 3 energy levels tested showed statistical significance when compared to the control (P < .05) with a permeability factor of 1.3 after 30 seconds of exposure, 1.3 after 60 seconds, and 1.5 after 120 seconds, where a permeability factor of 1 shows no increase in permeability. Current treatments for onychomycosis include systemic, topical, and surgical. Even when used all together, these treatments typically take a long time to result in nail healing, thus making this ultrasound-mediated device a promising alternative.

  19. General gauge mediation in five dimensions

    SciTech Connect

    McGarrie, Moritz; Russo, Rodolfo

    2010-08-01

    We use the ''general gauge mediation'' (GGM) formalism to describe a five-dimensional setup with an S{sup 1}/Z{sub 2} orbifold. We first consider a model independent supersymmetry breaking hidden sector on one boundary and generic chiral matter on another. Using the definition of GGM, the effects of the hidden sector are contained in a set of global symmetry current correlator functions and is mediated through the bulk. We find the gaugino, sfermion and hyperscalar mass formulas for minimal and generalized messengers in different regimes of a large, small and intermediate extra dimension. Then we use the five-dimensional GGM formalism to construct a model in which an SU(5) Intriligator, Seiberg and Shih (ISS) model is located on the hidden boundary. We weakly gauge a global symmetry of the ISS model and associate it with the bulk vector superfield. Compared to four-dimensional GGM, there is a natural way to adjust the gaugino versus sfermion mass ratio by a factor (Ml){sup 2}, where M is a characteristic mass scale of the supersymmetry breaking sector and l is the length of the extra dimension.

  20. Mediators and mucociliary clearance in asthma.

    PubMed

    Pavia, D; Lopez-Vidriero, M T; Clarke, S W

    1987-01-01

    Lung mucociliary clearance is significantly reduced in asthmatic patients compared to healthy controls even during clinical remission. Further retardation in mucous clearance occurs during sleep per se and this may be a contributing factor to nocturnal asthma. Chemical mediators of anaphylaxis appear to have various and, sometimes opposing effects on the two essential components for mucociliary clearance, namely cilia and mucus. Some mediators such as leukotrienes C4 and D4 are potent secretagogues and histamine increases the water flux into the lumen of the airways from the mucosa. Slow-reacting substance of anaphylaxis (SRS-A) reduces mucus transport whereas histamine enhances it. Ciliostimulation has been reported following allergen challenge and this contrasts with the cilioinhibitory effect of asthmatics' sputa. It appears however, that the net effect of the various chemicals of anaphylaxis is one of impairment of mucus clearance. Some pharmacological agents, used for the relief of bronchospasm and control of asthma, also stimulate mucociliary transport, a desirable additional effect. PMID:3311245

  1. Newborn Analgesia Mediated by Oxytocin during Delivery

    PubMed Central

    Mazzuca, Michel; Minlebaev, Marat; Shakirzyanova, Anastasia; Tyzio, Roman; Taccola, Giuliano; Janackova, Sona; Gataullina, Svetlana; Ben-Ari, Yehezkel; Giniatullin, Rashid; Khazipov, Rustem

    2011-01-01

    The mechanisms controlling pain in newborns during delivery are poorly understood. We explored the hypothesis that oxytocin, an essential hormone for labor and a powerful neuromodulator, exerts analgesic actions on newborns during delivery. Using a thermal tail-flick assay, we report that pain sensitivity is two-fold lower in rat pups immediately after birth than 2 days later. Oxytocin receptor antagonists strongly enhanced pain sensitivity in newborn, but not in 2-day-old rats, whereas oxytocin reduced pain at both ages suggesting an endogenous analgesia by oxytocin during delivery. Similar analgesic effects of oxytocin, measured as attenuation of pain-vocalization induced by electrical whisker pad stimulation, were also observed in decerebrated newborns. Oxytocin reduced GABA-evoked calcium responses and depolarizing GABA driving force in isolated neonatal trigeminal neurons suggesting that oxytocin effects are mediated by alterations of intracellular chloride. Unlike GABA signaling, oxytocin did not affect responses mediated by P2X3 and TRPV1 receptors. In keeping with a GABAergic mechanism, reduction of intracellular chloride by the diuretic NKCC1 chloride co-transporter antagonist bumetanide mimicked the analgesic actions of oxytocin and its effects on GABA responses in nociceptive neurons. Therefore, endogenous oxytocin exerts an analgesic action in newborn pups that involves a reduction of the depolarizing action of GABA on nociceptive neurons. Therefore, the same hormone that triggers delivery also acts as a natural pain killer revealing a novel facet of the protective actions of oxytocin in the fetus at birth. PMID:21519396

  2. Agrobacterium-mediated transformation of Fusarium proliferatum.

    PubMed

    Bernardi-Wenzel, J; Quecine, M C; Azevedo, J L; Pamphile, J A

    2016-06-03

    Fusarium proliferatum is an important pathogen that is associated with plant diseases and primarily affects aerial plant parts by producing different mycotoxins, which are toxic to humans and animals. Within the last decade, this fungus has also been described as one of the causes of red root rot or sudden death syndrome in soybean, which causes extensive damage to this crop. This study describes the Agrobacterium tumefaciens-mediated transformation of F. proliferatum as a tool for the disruption of pathogenicity genes. The genetic transformation was performed using two binary vectors (pCAMDsRed and pFAT-GFP) containing the hph (hygromycin B resistance) gene as a selection marker and red and green fluorescence, respectively. The presence of acetosyringone and the use of filter paper or nitrocellulose membrane were evaluated for their effect on the transformation efficiency. A mean processing rate of 94% was obtained with 96 h of co-cultivation only in the presence of acetosyringone and the use of filter paper or nitrocellulose membrane did not affect the transformation process. Hygromycin B resistance and the presence of the hph gene were confirmed by PCR, and fluorescence due to the expression of GFP and DsRed protein was monitored in the transformants. A high rate of mitotic stability (95%) was observed. The efficiency of Agrobacterium-mediated transformation of F. proliferatum allows the technique to be used for random insertional mutagenesis studies and to analyze fungal genes involved in the infection process.

  3. [Biological investigation of kinin-mediated angioedema].

    PubMed

    Defendi, F; Charignon, D; Ghannam, A; Ponard, D; Drouet, C

    2015-03-01

    Kinin-mediated angioedema results from accumulation of kinins, vasoactive and vasopermeant peptides, on the vascular endothelium. The disease is characterized by sudden episodes of swelling in the subcutaneous and submucosal tissues; the edema may occur spontaneously or it may be precipitated by triggering factors such as physical or emotional stress, or certain medicines. The characterization of kinin formation and catabolism systems helps improve knowledge of the aetiopathogenic mechanisms involved and provides the basis for classification of kinin-mediated angioedema conditions; thus, we may distinguish between angioedema with C1 inhibitor deficiency, whether inherited or acquired, and angioedema with normal C1 inhibitor activity, associated with increased kinin-forming activity or deficiency in kinin catabolism enzymes. In support of the clinical diagnosis, the physician may request laboratory investigation for a functional and molecular definition of the disease. Laboratory diagnosis is based on the characterization of: (1) kinin production control by C1 inhibitor investigation (function, antigen levels and circulating species); (2) kinin production (kininogenase activity, kininogen cleavage species); and (3) kinin catabolism enzymes (aminopeptidase P, carboxypeptidase N, angiotensin-I converting enzyme and dipeptidyl peptidase IV). An abnormal biological phenotype is supported by examination of susceptibility genes (SERPING1, F12 and XPNPEP2) and mutation segregation in the families. PMID:25683013

  4. Harm mediates the disgust-immorality link.

    PubMed

    Schein, Chelsea; Ritter, Ryan S; Gray, Kurt

    2016-09-01

    Many acts are disgusting, but only some of these acts are immoral. Dyadic morality predicts that disgusting acts should be judged as immoral to the extent that they seem harmful. Consistent with this prediction, 3 studies reveal that perceived harm mediates the link between feelings of disgust and moral condemnation-even for ostensibly harmless "purity" violations. In many cases, accounting for perceived harm completely eliminates the link between disgust and moral condemnation. Analyses also reveal the predictive power of anger and typicality/weirdness in moral judgments of disgusting acts. The mediation of disgust by harm holds across diverse acts including gay marriage, sex acts, and religious blasphemy. Revealing the endogenous presence and moral relevance of harm within disgusting-but-ostensibly harmless acts argues against modular accounts of moral cognition such as moral foundations theory. Instead, these data support pluralistic conceptions of harm and constructionist accounts of morality and emotion. Implications for moral cognition and the concept of "purity" are discussed. (PsycINFO Database Record PMID:27100369

  5. Ligament Mediated Fragmentation of Viscoelastic Liquids

    NASA Astrophysics Data System (ADS)

    Keshavarz, Bavand; Houze, Eric C.; Moore, John R.; Koerner, Michael R.; McKinley, Gareth H.

    2016-10-01

    The breakup and atomization of complex fluids can be markedly different than the analogous processes in a simple Newtonian fluid. Atomization of paint, combustion of fuels containing antimisting agents, as well as physiological processes such as sneezing are common examples in which the atomized liquid contains synthetic or biological macromolecules that result in viscoelastic fluid characteristics. Here, we investigate the ligament-mediated fragmentation dynamics of viscoelastic fluids in three different canonical flows. The size distributions measured in each viscoelastic fragmentation process show a systematic broadening from the Newtonian solvent. In each case, the droplet sizes are well described by Gamma distributions which correspond to a fragmentation-coalescence scenario. We use a prototypical axial step strain experiment together with high-speed video imaging to show that this broadening results from the pronounced change in the corrugated shape of viscoelastic ligaments as they separate from the liquid core. These corrugations saturate in amplitude and the measured distributions for viscoelastic liquids in each process are given by a universal probability density function, corresponding to a Gamma distribution with nmin=4 . The breadth of this size distribution for viscoelastic filaments is shown to be constrained by a geometrical limit which can not be exceeded in ligament-mediated fragmentation phenomena.

  6. Depression and pain: testing of serial multiple mediators

    PubMed Central

    Wongpakaran, Tinakon; Wongpakaran, Nahathai; Tanchakvaranont, Sitthinant; Bookkamana, Putipong; Pinyopornpanish, Manee; Wannarit, Kamonporn; Satthapisit, Sirina; Nakawiro, Daochompu; Hiranyatheb, Thanita; Thongpibul, Kulvadee

    2016-01-01

    Purpose Despite the fact that pain is related to depression, few studies have been conducted to investigate the variables that mediate between the two conditions. In this study, the authors explored the following mediators: cognitive function, self-sacrificing interpersonal problems, and perception of stress, and the effects they had on pain symptoms among patients with depressive disorders. Participants and methods An analysis was performed on the data of 346 participants with unipolar depressive disorders. The 17-item Hamilton Depression Rating Scale, Mini-Mental State Examination, the pain subscale of the health-related quality of life (SF-36), the self-sacrificing subscale of the Inventory of Interpersonal Problems, and the Perceived Stress Scale were used. Parallel multiple mediator and serial multiple mediator models were used. An alternative model regarding the effect of self-sacrificing on pain was also proposed. Results Perceived stress, self-sacrificing interpersonal style, and cognitive function were found to significantly mediate the relationship between depression and pain, while controlling for demographic variables. The total effect of depression on pain was significant. This model, with an additional three mediators, accounted for 15% of the explained variance in pain compared to 9% without mediators. For the alternative model, after controlling for the mediators, a nonsignificant total direct effect level of self-sacrificing was found, suggesting that the effect of self-sacrificing on pain was based only on an indirect effect and that perceived stress was found to be the strongest mediator. Conclusion Serial mediation may help us to see how depression and pain are linked and what the fundamental mediators are in the chain. No significant, indirect effect of self-sacrificing on pain was observed, if perceived stress was not part of the depression and/or cognitive function mediational chain. The results shown here have implications for future

  7. Mediation analyses: applications in nutrition research and reading the literature.

    PubMed

    Lockwood, Chondra M; DeFrancesco, Carol A; Elliot, Diane L; Beresford, Shirley A A; Toobert, Deborah J

    2010-05-01

    Mediation analysis is a newer statistical tool that is becoming more prominent in nutrition research. Its use provides insight into the relationship among variables in a potential causal chain. For intervention studies, it can define the influence of different programmatic components and, in doing so, allows investigators to identify and refine a program's critical aspects. We present an overview of mediation analysis, compare mediators with other variables (confounders, moderators, and covariates), and illustrate how mediation analysis permits interpretation of the change process. A framework is outlined for the critical appraisal of articles purporting to use mediation analysis. The framework's utility is demonstrated by searching the nutrition literature and identifying articles citing mediation cross referenced with the terms "nutrition," "diet," "food," and "obesity." Seventy-two articles were identified that involved human subjects and behavior outcomes, and almost half mentioned mediation without tests to define its presence. Tabulation of the 40 articles appropriately assessing mediation demonstrates an increase in these techniques' appearance and the breadth of nutrition topics addressed. Mediation analysis is an important new statistical tool. Familiarity with its methodology and a framework for assessing articles will allow readers to critically appraise the literature and make informed independent evaluations of works using these techniques.

  8. Mediation Analyses: Applications in Nutrition Research and Reading the Literature

    PubMed Central

    Lockwood, Chondra M.; DeFrancesco, Carol A.; Elliot, Diane L.; Beresford, Shirley A.A.; Toobert, Deborah J.

    2010-01-01

    Mediation analysis is a newer statistical tool that is becoming more prominent in nutritional research. Its use provides insight into the relationship among variables in a potential causal chain. For intervention studies, it can define the impact of different programmatic components, and in doing so allow investigators to identify and refine a program’s critical aspects. We present an overview of mediation analysis, compare mediators with other variables (confounders, moderators and covariates) and illustrate how mediation analysis permits interpretation of the change process. A framework is outlined for the critical appraisal of articles purporting to use mediation analysis. The framework’s utility is demonstrated by searching the nutrition literature and identifying articles citing mediation cross referenced with nutrition, diet, food and obesity. Seventy-two articles were identified that involved human subjects and behavioral outcomes, and almost half mentioned mediation without tests to define its presence. Tabulation of the 40 articles appropriately assessing mediation demonstrates an increase in these techniques’ appearance and the breadth of nutrition topics addressed. Mediation analysis is an important new statistical tool. Familiarity with its methodology and a framework for assessing articles will allow readers to critically appraise the literature and make informed independent evaluations of works using these techniques. PMID:20430137

  9. The role of mediation in resolving workplace relationship conflict.

    PubMed

    McKenzie, Donna Margaret

    2015-01-01

    Stress triggered by workplace-based interpersonal conflict can result in damaged relationships, loss of productivity, diminished job satisfaction and increasingly, workers' compensation claims for psychological injury. This paper examined the literature on the role and effectiveness of mediation, as the most common method of Alternative Dispute Resolution, in resolving workplace relationship conflict. Available evidence suggests that mediation is most effective when supported by organisational commitment to ADR strategies, policies and processes, and conducted by independent, experienced and qualified mediators. The United States Postal Service program REDRESS™ is described as an illustration of the successful use of mediation to resolve conflict in the workplace.

  10. The role of mediation in resolving workplace relationship conflict.

    PubMed

    McKenzie, Donna Margaret

    2015-01-01

    Stress triggered by workplace-based interpersonal conflict can result in damaged relationships, loss of productivity, diminished job satisfaction and increasingly, workers' compensation claims for psychological injury. This paper examined the literature on the role and effectiveness of mediation, as the most common method of Alternative Dispute Resolution, in resolving workplace relationship conflict. Available evidence suggests that mediation is most effective when supported by organisational commitment to ADR strategies, policies and processes, and conducted by independent, experienced and qualified mediators. The United States Postal Service program REDRESS™ is described as an illustration of the successful use of mediation to resolve conflict in the workplace. PMID:25660062

  11. Using mediation to resolve disputes among hospitals and physicians.

    PubMed

    Duncheon, M A

    1999-06-01

    The wide variety of economic cooperative arrangements in which hospitals and physicians engage can lead to disputes. As methods of dispute resolution, litigation and arbitration are costly and time-consuming and can have long-lasting adverse effects on relationships between the disputing parties. An alternative method of dispute resolution is mediation, the process of voluntarily negotiating a settlement with the help of a mediator. Mediation generally is quicker, less costly, and less likely to be adversarial than litigation or arbitration. In addition, mediation offers privacy regarding the nature of the dispute, thus preserving valuable reputations. PMID:10558174

  12. Megakaryocyte-mediated inhibition of osteoclast development.

    PubMed

    Kacena, Melissa A; Nelson, Tracy; Clough, Mary E; Lee, Sun-Kyeong; Lorenzo, Joseph A; Gundberg, Caren M; Horowitz, Mark C

    2006-11-01

    A growing body of evidence indicates that megakaryocytes (MK) or their growth factors play a role in skeletal homeostasis. We previously identified a novel regulatory pathway that controls bone formation, which is mediated by MK. In vivo megakaryocytosis resulted in massive bone formation. The co-culture of MK with osteoblasts (OB) resulted in increased OB proliferation in vitro, by a mechanism that required direct cell-to-cell contact. Here, we examined a second MK-mediated pathway that regulates osteoclast (OC) development. We have begun examining the unique inhibitory effect of MK on OC development. Spleen or bone marrow (BM) cells from C57BL/6 mice, as a source of OC precursors, were cultured with M-CSF and RANKL to induce OC development. MK were prepared by culturing fetal liver cells with thrombopoietin and separating cells into MK and non-MK populations. MK were titrated into spleen cell cultures and OC were identified as tartrate-resistant acid phosphatase-positive giant cells with >3 nuclei. There was a significant, P < 0.001, up to 10-fold reduction in OC formed when MK were added to the spleen cell cultures. We determined that 30% (vol:vol) MK conditioned media (CM) were able to completely block OC development from precursors, whereas 3% MK CM resulted in up to a 10-fold reduction in OC development, P < 0.001. These data indicate that a soluble factor(s) was responsible, at least in part, for the inhibition. We examined MK CM for known inhibitors of OC formation, using ELISAs. IL-4 was undetectable in MK CM, whereas IL-10 and IFN-gamma levels were similar in MK and non-MK CM. TGFbeta-1 levels were increased 2-fold in MK CM compared to control CM but were not responsible for the inhibition in OC development. Although, we found a significant increase in the levels of osteoprotegerin (OPG) in MK CM, antibody neutralization studies, MK derived from OPG-deficient mice, and tandem mass spectrophotometry, all confirm that OPG was not responsible for the MK-mediated

  13. Solvent mediated self-assembly of solids

    SciTech Connect

    De Yoreo, J.; Wilson, W.D.; Palmore, T.

    1997-12-12

    Solvent-mediated crystallization represents a robust approach to self-assembly of nanostructures and microstructures. In organic systems, the relative ease with which the structure of hydrogen- bonded molecules can be manipulated allows for generation of a wide variety of nanoscale crystal structures. In living organisms, control over the micron-to-millimeter form of inorganic crystals is achieved through introduction of bio-organic molecules. The purpose of this proposal is to understand the interplay between solution chemistry, molecular structure, surface chemistry, and the processes of nucleation and crystal growth in solvent-mediated systems, with the goal of developing the atomic and molecular basis of a solvent-mediated self-assembly technology. We will achieve this purpose by: (1) utilizing an atomic force microscopy (AFM) approach that provides in situ, real time imaging during growth from solutions, (2) by modifying kinetic Monte Carlo (KMC) models to include solution-surface kinetics, (3) by introducing quantum chemistry (QC) calculations of the potentials of the relevant chemical species and the near-surface structure of the solution, and (4) by utilizing molecular dynamics (MD) simulations to identify the minimum energy pathways to the solid state. Our work will focus on two systems chosen to address both the manometer and micron-to-millimeter length scales of assembly, the family of 2,5- diketopiperazines (X-DKPs) and the system of CaCO{sub 3} with amino acids. Using AFM, we will record the evolution of surface morphology, critical lengths, step speeds, and step-step interactions as a function of supersaturation and temperature. In the case of the X-DKPs, these measurements will be repeated as the molecular structure of the growth unit is varied. In the case of CaCO{sub 3}, they will be performed as a function of solution chemistry including pH, ionic strength, and amino acid content. In addition, we will measure nucleation rates and orientations of

  14. LHC benchmarks from flavored gauge mediation

    NASA Astrophysics Data System (ADS)

    Ierushalmi, N.; Iwamoto, S.; Lee, G.; Nepomnyashy, V.; Shadmi, Y.

    2016-07-01

    We present benchmark points for LHC searches from flavored gauge mediation models, in which messenger-matter couplings give flavor-dependent squark masses. Our examples include spectra in which a single squark — stop, scharm, or sup — is much lighter than all other colored superpartners, motivating improved quark flavor tagging at the LHC. Many examples feature flavor mixing; in particular, large stop-scharm mixing is possible. The correct Higgs mass is obtained in some examples by virtue of the large stop A-term. We also revisit the general flavor and CP structure of the models. Even though the A-terms can be substantial, their contributions to EDM's are very suppressed, because of the particular dependence of the A-terms on the messenger coupling. This holds regardless of the messenger-coupling texture. More generally, the special structure of the soft terms often leads to stronger suppression of flavor- and CP-violating processes, compared to naive estimates.

  15. Yukawa unification predictions with effective "mirage" mediation.

    PubMed

    Anandakrishnan, Archana; Raby, Stuart

    2013-11-22

    In this Letter we analyze the consequences, for the LHC, of gauge and third family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unified theory (GUT) scale, which we characterize as effective "mirage" mediation. We perform a global χ2 analysis including the observables M(W), M(Z), G(F), α(em)(-1), α(s)(M(Z)), M(t), m(b)(m(b)), M(τ), BR(B→X(s)γ), BR(B(s)→μ(+)μ(-)), and M(h). The fit is performed in the minimal supersymmetric standard model in terms of 10 GUT scale parameters, while tanβ and μ are fixed at the weak scale. We find good fits to the low energy data and a supersymmetry spectrum which is dramatically different than previously studied in the context of Yukawa unification. PMID:24313477

  16. Yukawa Unification Predictions with Effective ``Mirage'' Mediation

    NASA Astrophysics Data System (ADS)

    Anandakrishnan, Archana; Raby, Stuart

    2013-11-01

    In this Letter we analyze the consequences, for the LHC, of gauge and third family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unified theory (GUT) scale, which we characterize as effective “mirage” mediation. We perform a global χ2 analysis including the observables MW, MZ, GF, αem-1, αs(MZ), Mt, mb(mb), Mτ, BR(B→Xsγ), BR(Bs→μ+μ-), and Mh. The fit is performed in the minimal supersymmetric standard model in terms of 10 GUT scale parameters, while tan⁡β and μ are fixed at the weak scale. We find good fits to the low energy data and a supersymmetry spectrum which is dramatically different than previously studied in the context of Yukawa unification.

  17. Diet-mediated alteration of chromatin structure.

    PubMed

    Castro, C E; Armstrong-Major, J; Ramirez, M E

    1986-08-01

    Higher-order chromatin structure and the process of transcription are related. The significance of a nutritional state's altering chromatin structure lies in the potential role of that nutritional state in the regulation of gene expression. In rats short-term feeding of semisynthetic diets varying in the proportion of carbohydrate, protein, or fat alters the configuration of liver chromatin as measured by sensitivity to micrococcal nuclease (EC 3.1.31.1). A carbohydrate-rich, fat-free diet increases the sensitivity of rat liver chromatin to micrococcal nuclease and decreases the nucleosome repeat length. In contrast, a protein-free diet or a diet deficient in magnesium or zinc decreases the sensitivity of liver nuclear chromatin to micrococcal nuclease. Diet-mediated mechanisms that alter chromatin structure are now unknown, but the continued study of nutritional interaction with the genome should identify the responsible features as well as their significance to gene function.

  18. The mediating role of facebook fan pages.

    PubMed

    Chih, Wen-Hai; Hsu, Li-Chun; Wang, Kai-Yu; Lin, Kuan-Yu

    2014-01-01

    Using the dual mediation hypothesis, this study investigates the role of interestingness (the power of attracting or holding one's attention) attitude towards the news, in the formation of Facebook Fan Page users' electronic word-of-mouth intentions. A total of 599 Facebook fan page users in Taiwan were recruited and structural equation modeling (SEM) was used to test the research hypotheses. The results show that both perceived news entertainment and informativeness positively influence interestingness attitude towards the news. Interestingness attitude towards the news subsequently influences hedonism and utilitarianism attitudes towards the Fan Page, which then influence eWOM intentions. Interestingness attitude towards the news plays a more important role than hedonism and utilitarianism attitudes in generating electronic word-of-mouth intentions. Based on the findings, the implications and future research suggestions are provided. PMID:24875695

  19. Symbiont-mediated RNA interference in insects.

    PubMed

    Whitten, Miranda M A; Facey, Paul D; Del Sol, Ricardo; Fernández-Martínez, Lorena T; Evans, Meirwyn C; Mitchell, Jacob J; Bodger, Owen G; Dyson, Paul J

    2016-02-24

    RNA interference (RNAi) methods for insects are often limited by problems with double-stranded (ds) RNA delivery, which restricts reverse genetics studies and the development of RNAi-based biocides. We therefore delegated to insect symbiotic bacteria the task of: (i) constitutive dsRNA synthesis and (ii) trauma-free delivery. RNaseIII-deficient, dsRNA-expressing bacterial strains were created from the symbionts of two very diverse pest species: a long-lived blood-sucking bug, Rhodnius prolixus, and a short-lived globally invasive polyphagous agricultural pest, western flower thrips (Frankliniella occidentalis). When ingested, the manipulated bacteria colonized the insects, successfully competed with the wild-type microflora, and sustainably mediated systemic knockdown phenotypes that were horizontally transmissible. This represents a significant advance in the ability to deliver RNAi, potentially to a large range of non-model insects. PMID:26911963

  20. ROS and ROS-Mediated Cellular Signaling

    PubMed Central

    Zhang, Jixiang; Wang, Xiaoli; Vikash, Vikash; Ye, Qing; Wu, Dandan; Liu, Yulan; Dong, Weiguo

    2016-01-01

    It has long been recognized that an increase of reactive oxygen species (ROS) can modify the cell-signaling proteins and have functional consequences, which successively mediate pathological processes such as atherosclerosis, diabetes, unchecked growth, neurodegeneration, inflammation, and aging. While numerous articles have demonstrated the impacts of ROS on various signaling pathways and clarify the mechanism of action of cell-signaling proteins, their influence on the level of intracellular ROS, and their complex interactions among multiple ROS associated signaling pathways, the systemic summary is necessary. In this review paper, we particularly focus on the pattern of the generation and homeostasis of intracellular ROS, the mechanisms and targets of ROS impacting on cell-signaling proteins (NF-κB, MAPKs, Keap1-Nrf2-ARE, and PI3K-Akt), ion channels and transporters (Ca2+ and mPTP), and modifying protein kinase and Ubiquitination/Proteasome System. PMID:26998193

  1. Cell-mediated immunity in anorexia nervosa.

    PubMed Central

    Cason, J; Ainley, C C; Wolstencroft, R A; Norton, K R; Thompson, R P

    1986-01-01

    Twelve patients with anorexia nervosa were studied for cell-mediated immunity in terms of delayed hypersensitivity reactions to recall antigens, lymphocyte transformation responses to T-cell mitogens, and numbers of circulating leucocytes and T-cell subpopulations. Compared to controls, all patients had reduced cutaneous reactions and four were anergic. There was a mild leucopenia in patients and both T4+ and T3+ numbers were slightly reduced. Mean peak transformation responses for patients were slightly lower than controls for phytohaemagglutinin, but not for concanavalin A; however, patients required greater doses of mitogens to elicit peak transformation responses. Plasmas from patients did not contain inhibitors of transformation responses. We conclude that there are functional cellular abnormalities associated with the under-nutrition of anorexia nervosa. PMID:3742879

  2. Novel mediators and biomarkers of thrombosis.

    PubMed

    Sexton, Travis; Smyth, Susan S

    2014-01-01

    Spurred by advances in understanding the molecular basis of thrombosis, this issue of the Journal of Thrombosis and Thrombolysis is devoted to exploring aspects of novel paradigms and their potential impact on diagnosis and treatment. Complex interplay between blood and vascular cells, inflammation, and pro- and anti-coagulant pathways determines the formation and stability of arterial and venous thrombosis. A causal role for inflammation in coronary artery disease is currently being tested in large clinical trials. Basic science observations implicate inflammation in venous thromboembolic disorders and inflammatory processes, may have a similar influence on device thrombosis. In this article and throughout this issue of the Journal, we discuss biomarkers and mediators associated with arterial and venous thrombosis, atrial fibrillation, and other clinical scenarios. PMID:24356857

  3. From perceptual to language-mediated categorization

    PubMed Central

    Westermann, Gert; Mareschal, Denis

    2014-01-01

    From at least two months onwards, infants can form perceptual categories. During the first year of life, object knowledge develops from the ability to represent individual object features to representing correlations between attributes and to integrate information from different sources. At the end of the first year, these representations are shaped by labels, opening the way to conceptual knowledge. Here, we review the development of object knowledge and object categorization over the first year of life. We then present an artificial neural network model that models the transition from early perceptual categorization to categories mediated by labels. The model informs a current debate on the role of labels in object categorization by suggesting that although labels do not act as object features they nevertheless affect perceived similarity of perceptually distinct objects sharing the same label. The model presents the first step of an integrated account from early perceptual categorization to language-based concept learning. PMID:24324235

  4. Epigenetics and therapeutic targets mediating neuroprotection.

    PubMed

    Qureshi, Irfan A; Mehler, Mark F

    2015-12-01

    The rapidly evolving science of epigenetics is transforming our understanding of the nervous system in health and disease and holds great promise for the development of novel diagnostic and therapeutic approaches targeting neurological diseases. Increasing evidence suggests that epigenetic factors and mechanisms serve as important mediators of the pathogenic processes that lead to irrevocable neural injury and of countervailing homeostatic and regenerative responses. Epigenetics is, therefore, of considerable translational significance to the field of neuroprotection. In this brief review, we provide an overview of epigenetic mechanisms and highlight the emerging roles played by epigenetic processes in neural cell dysfunction and death and in resultant neuroprotective responses. This article is part of a Special Issue entitled SI: Neuroprotection.

  5. Symbiont-mediated RNA interference in insects

    PubMed Central

    Whitten, Miranda M. A.; Facey, Paul D.; Del Sol, Ricardo; Fernández-Martínez, Lorena T.; Evans, Meirwyn C.; Mitchell, Jacob J.; Bodger, Owen G.

    2016-01-01

    RNA interference (RNAi) methods for insects are often limited by problems with double-stranded (ds) RNA delivery, which restricts reverse genetics studies and the development of RNAi-based biocides. We therefore delegated to insect symbiotic bacteria the task of: (i) constitutive dsRNA synthesis and (ii) trauma-free delivery. RNaseIII-deficient, dsRNA-expressing bacterial strains were created from the symbionts of two very diverse pest species: a long-lived blood-sucking bug, Rhodnius prolixus, and a short-lived globally invasive polyphagous agricultural pest, western flower thrips (Frankliniella occidentalis). When ingested, the manipulated bacteria colonized the insects, successfully competed with the wild-type microflora, and sustainably mediated systemic knockdown phenotypes that were horizontally transmissible. This represents a significant advance in the ability to deliver RNAi, potentially to a large range of non-model insects. PMID:26911963

  6. Masking mediated print defect visibility predictor

    NASA Astrophysics Data System (ADS)

    Jing, Xiaochen; Nachlieli, Hila; Shaked, Doron; Shiffman, Smadar; Allebach, Jan P.

    2012-01-01

    Banding is a well-known artifact produced by printing systems. It usually appears as lines perpendicular to the process direction of the print. Therefore, banding is an important print quality issue which has been analyzed and assessed by many researchers. However, little literature has focused on the study of the masking effect of content for this kind of print quality issue. Compared with other image and print quality research, our work is focused on the print quality of typical documents printed on a digital commercial printing press. In this paper, we propose a Masking Mediated Print Defect Visibility Predictor (MMPDVP) to predict the visibility of defects in the presence of customer content. The parameters of the algorithm are trained from ground-truth images that have been marked by subjects. The MMPDVP could help the press operator decide whether the print quality is acceptable for specific customer requirements. Ultimately, this model can be used to optimize the print-shop workflow.

  7. Topoisomerase II Mediates Meiotic Crossover Interference

    PubMed Central

    Zhang, Liangran; Wang, Shunxin; Yin, Shen; Hong, Soogil; Kim, Keun P.; Kleckner, Nancy

    2014-01-01

    Summary Spatial patterning is a ubiquitous feature of biological systems. Meiotic crossovers provide an interesting example, defined by the classical phenomenon of crossover interference. Here, analysis of crossover patterns in budding yeast identifies a molecular pathway for interference. Topoisomerase II (Topo II) plays a central role, thus identifying a new function for this critical molecule. SUMOylation [of TopoII and axis component Red1] and ubiquitin-mediated removal of SUMOylated proteins are also required. These and other findings support the hypothesis that crossover interference involves accumulation, relief and redistribution of mechanical stress along the protein/DNA meshwork of meiotic chromosome axes, with TopoII required to adjust spatial relationships among DNA segments. PMID:25043020

  8. Turgor-mediated transport of sugars

    SciTech Connect

    Daie, J.

    1986-04-01

    Membrane associated processes have been suggested to be modulated by cellular turgor. The nature of this regulation is not, however, clearly understood. Evidence is presented that active but not passive transport of sugars is turgor regulated. Isolated phloem tissue, vascular bundles or storage parenchyma of celery were incubated in buffered solutions adjusted to 100, 200 or 400 m osmolal that contained various concentrations of /sup 14/C-sugars. Cellular turgor was manipulated by using the non-permeating PEG (3350). Saturating carrier-mediated sucrose transport which is present only in phloem-containing tissue was enhanced under low turgor conditions. Sucrose diffusion, the predominant mode of uptake in non-phloem parenchyma tissue was not affected by cellular turgor. Furthermore, GA and IAA seem to interact with cellular turgor to bring about modified rates of sucrose uptake. The data are consistent with observations that sucrose loading is enhanced under mild water deficit conditions.

  9. Ethylene-Mediated Acclimations to Flooding Stress.

    PubMed

    Sasidharan, Rashmi; Voesenek, Laurentius A C J

    2015-09-01

    Flooding is detrimental for plants, primarily because of restricted gas exchange underwater, which leads to an energy and carbohydrate deficit. Impeded gas exchange also causes rapid accumulation of the volatile ethylene in all flooded plant cells. Although several internal changes in the plant can signal the flooded status, it is the pervasive and rapid accumulation of ethylene that makes it an early and reliable flooding signal. Not surprisingly, it is a major regulator of several flood-adaptive plant traits. Here, we discuss these major ethylene-mediated traits, their functional relevance, and the recent progress in identifying the molecular and signaling events underlying these traits downstream of ethylene. We also speculate on the role of ethylene in postsubmergence recovery and identify several questions for future investigations.

  10. Mast Cell-Mediated Mechanisms of Nociception

    PubMed Central

    Aich, Anupam; Afrin, Lawrence B.; Gupta, Kalpna

    2015-01-01

    Mast cells are tissue-resident immune cells that release immuno-modulators, chemo-attractants, vasoactive compounds, neuropeptides and growth factors in response to allergens and pathogens constituting a first line of host defense. The neuroimmune interface of immune cells modulating synaptic responses has been of increasing interest, and mast cells have been proposed as key players in orchestrating inflammation-associated pain pathobiology due to their proximity to both vasculature and nerve fibers. Molecular underpinnings of mast cell-mediated pain can be disease-specific. Understanding such mechanisms is critical for developing disease-specific targeted therapeutics to improve analgesic outcomes. We review molecular mechanisms that may contribute to nociception in a disease-specific manner. PMID:26690128

  11. Yukawa unification predictions with effective "mirage" mediation.

    PubMed

    Anandakrishnan, Archana; Raby, Stuart

    2013-11-22

    In this Letter we analyze the consequences, for the LHC, of gauge and third family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unified theory (GUT) scale, which we characterize as effective "mirage" mediation. We perform a global χ2 analysis including the observables M(W), M(Z), G(F), α(em)(-1), α(s)(M(Z)), M(t), m(b)(m(b)), M(τ), BR(B→X(s)γ), BR(B(s)→μ(+)μ(-)), and M(h). The fit is performed in the minimal supersymmetric standard model in terms of 10 GUT scale parameters, while tanβ and μ are fixed at the weak scale. We find good fits to the low energy data and a supersymmetry spectrum which is dramatically different than previously studied in the context of Yukawa unification.

  12. Agrobacterium-mediated transformation of Brachypodium distachyon.

    PubMed

    Thole, Vera; Vain, Philippe

    2012-01-01

    Brachypodium distachyon is an attractive genomics and biological model system for grass research. Recently, the complete annotated genome sequence of the diploid line Bd21 has been released. Genetic transformation technologies are critical for the discovery and validation of gene function in Brachypodium. Here, we describe an efficient procedure enabling the Agrobacterium-mediated transformation of a range of diploid and polyploid genotypes of Brachypodium. The procedure relies on the transformation of compact embryogenic calli derived from immature embryos using either chemical selection alone or a combination of chemical and visual screening of transformed tissues and plants. Transformation efficiencies of around 20% can routinely be achieved using this protocol. In the context of the BrachyTAG programme (BrachyTAG.org), this procedure made possible the mass production of Bd21T-DNA mutant plant lines.

  13. Oxygen radicals and asbestos-mediated disease.

    PubMed Central

    Quinlan, T R; Marsh, J P; Janssen, Y M; Borm, P A; Mossman, B T

    1994-01-01

    Asbestos fibers are potent elaborators of active oxygen species whether by reactions involving iron on the surface of the fiber, or by attempted phagocytosis of fibers by cell types resident in the lung. The link between production of active oxygen species and the pathogenesis of asbestos-mediated disease has been highlighted by studies outlined here exploring the use of antioxidant scavengers which inhibit the cytotoxic effects of asbestos both in vitro and in vivo. The use of antioxidant enzymes ameliorates the induction of certain genes necessary for cell proliferation, such as ornithine decarboxylase, implicating oxidants as causative factors in some abnormal cell replicative events. Based on these observations, antioxidant enzymes likely represent an important lung defense mechanism in response to oxidative stress. In addition, their gene expression in lung or in cells from bronchoalveolar lavage might be a valuable biomarker of chronic inflammation and pulmonary disease after inhalation of oxidants. PMID:7705283

  14. Microneedle-mediated transdermal bacteriophage delivery

    PubMed Central

    Ryan, Elizabeth; Garland, Martin J.; Singh, Thakur Raghu Raj; Bambury, Eoin; O’Dea, John; Migalska, Katarzyna; Gorman, Sean P.; McCarthy, Helen O.; Gilmore, Brendan F.; Donnelly, Ryan F.

    2012-01-01

    Interest in bacteriophages as therapeutic agents has recently been reawakened. Parenteral delivery is the most routinely-employed method of administration. However, injection of phages has numerous disadvantages, such as the requirement of a health professional for administration and the possibility of cross-contamination. Transdermal delivery offers one potential means of overcoming many of these problems. The present study utilized a novel poly (carbonate) (PC) hollow microneedle (MN) device for the transdermal delivery of Escherichia coli-specific T4 bacteriophages both in vitro and in vivo. MN successfully achieved bacteriophage delivery in vitro across dermatomed and full thickness skin. A concentration of 2.67 × 106 PFU/ml (plaque forming units per ml) was detected in the receiver compartment when delivered across dermatomed skin and 4.0 × 103 PFU/ml was detected in the receiver compartment when delivered across full thickness skin. An in vivo study resulted in 4.13 × 103 PFU/ml being detected in blood 30 min following initial MN-mediated phage administration. Clearance occurred rapidly, with phages being completely cleared from the systemic circulation within 24 h, which was expected in the absence of infection. We have shown here that MN-mediated delivery allows successful systemic phage absorption. Accordingly, bacteriophage-based therapeutics may now have an alternative route for systemic delivery. Once fully-investigated, this could lead to more widespread investigation of these interesting therapeutic viruses. PMID:22750416

  15. CFTR and sphingolipids mediate hypoxic pulmonary vasoconstriction.

    PubMed

    Tabeling, Christoph; Yu, Hanpo; Wang, Liming; Ranke, Hannes; Goldenberg, Neil M; Zabini, Diana; Noe, Elena; Krauszman, Adrienn; Gutbier, Birgitt; Yin, Jun; Schaefer, Michael; Arenz, Christoph; Hocke, Andreas C; Suttorp, Norbert; Proia, Richard L; Witzenrath, Martin; Kuebler, Wolfgang M

    2015-03-31

    Hypoxic pulmonary vasoconstriction (HPV) optimizes pulmonary ventilation-perfusion matching in regional hypoxia, but promotes pulmonary hypertension in global hypoxia. Ventilation-perfusion mismatch is a major cause of hypoxemia in cystic fibrosis. We hypothesized that cystic fibrosis transmembrane conductance regulator (CFTR) may be critical in HPV, potentially by modulating the response to sphingolipids as mediators of HPV. HPV and ventilation-perfusion mismatch were analyzed in isolated mouse lungs or in vivo. Ca(2+) mobilization and transient receptor potential canonical 6 (TRPC6) translocation were studied in human pulmonary (PASMCs) or coronary (CASMCs) artery smooth muscle cells. CFTR inhibition or deficiency diminished HPV and aggravated ventilation-perfusion mismatch. In PASMCs, hypoxia caused CFTR to interact with TRPC6, whereas CFTR inhibition attenuated hypoxia-induced TRPC6 translocation to caveolae and Ca(2+) mobilization. Ca(2+) mobilization by sphingosine-1-phosphate (S1P) was also attenuated by CFTR inhibition in PASMCs, but amplified in CASMCs. Inhibition of neutral sphingomyelinase (nSMase) blocked HPV, whereas exogenous nSMase caused TRPC6 translocation and vasoconstriction that were blocked by CFTR inhibition. nSMase- and hypoxia-induced vasoconstriction, yet not TRPC6 translocation, were blocked by inhibition or deficiency of sphingosine kinase 1 (SphK1) or antagonism of S1P receptors 2 and 4 (S1P2/4). S1P and nSMase had synergistic effects on pulmonary vasoconstriction that involved TRPC6, phospholipase C, and rho kinase. Our findings demonstrate a central role of CFTR and sphingolipids in HPV. Upon hypoxia, nSMase triggers TRPC6 translocation, which requires its interaction with CFTR. Concomitant SphK1-dependent formation of S1P and activation of S1P2/4 result in phospholipase C-mediated TRPC6 and rho kinase activation, which conjointly trigger vasoconstriction. PMID:25829545

  16. Spring-mediated mandibular distraction osteogenesis.

    PubMed

    Mofid, Mehrdad M; Inoue, Nozomu; Tufaro, Anthony P; Vander Kolk, Craig A; Manson, Paul N

    2003-09-01

    Successful performance of distraction osteogenesis requires rigorous patient compliance with a daily activation regimen of a percutaneous screw. Previous clinical studies have found that failure of patient compliance with this regimen is the most common complication leading to technical failure of the distraction process. The authors have developed an internalized spring-mediated device for mandibular distraction osteogenesis that can potentially abrogate the risks associated with patient compliance by allowing for automated distraction across an osteotomy. Twenty adult New Zealand White rabbits underwent unilateral mandibular osteotomy. A segment of nickel-titanium shape memory alloy reinforced at both ends with a pinball was fashioned into an inferiorly based arc and secured to the mandible with stainless steel wire. On postoperative day 12, spring activation commenced by cutting a wire binding the two pinballs to one another. Animals were observed for 6 weeks before they were killed. Radiographic studies and decalcified histologic analysis were performed on extracted mandibles. Temperature- and displacement-dependent properties of the shape memory alloy were also examined. Five animals were excluded from the study due to infection, nonunion, or device failure. A mean distraction of 1.2 mm in the distracted hemimandible relative to the nonoperated hemimandible was found (P <.001, two-tailed paired t test). The maximum distraction achieved in an experimental specimen using the spring distractor was 3.7 mm. There were no other histologic or radiographic differences found between study specimens and specimens subjected to traditional distraction methods. Biomechanical testing of the shape memory alloy revealed a temperature-dependent increase in force at body temperature compared with room temperature and a reduction in force with increased displacement of the spring. This study demonstrates the feasibility of spring-mediated distraction osteogenesis across an

  17. Transformation of rice mediated by Agrobacterium tumefaciens.

    PubMed

    Hiei, Y; Komari, T; Kubo, T

    1997-09-01

    Agrobacterium tumefaciens has been routinely utilized in gene transfer to dicotyledonous plants, but monocotyledonous plants including important cereals were thought to be recalcitrant to this technology as they were outside the host range of crown gall. Various challenges to infect monocotyledons including rice with Agrobacterium had been made in many laboratories, but the results were not conclusive until recently. Efficient transformation protocols mediated by Agrobacterium were reported for rice in 1994 and 1996. A key point in the protocols was the fact that tissues consisting of actively dividing, embryonic cells, such as immature embryos and calli induced from scutella, were co-cultivated with Agrobacterium in the presence of acetosyringonc, which is a potent inducer of the virulence genes. It is now clear that Agrobacterium is capable of transferring DNA to monocotyledons if tissues containing 'competent' cells are infected. The studies of transformation of rice suggested that numerous factors including genotype of plants, types and ages of tissues inoculated, kind of vectors, strains of Agrobacterium, selection marker genes and selective agents, and various conditions of tissue culture, are of critical importance. Advantages of the Agrobacterium-mediated transformation in rice, like on dicotyledons, include the transfer of pieces of DNA with defined ends with minimal rearrangements, the transfer of relatively large segments of DNA, the integration of small numbers of copies of genes into plant chromosomes, and high quality and fertility of transgenic plants. Delivery of foreign DNA to rice plants via A. tumefaciens is a routine technique in a growing number of laboratories. This technique will allow the genetic improvement of diverse varieties of rice, as well as studies of many aspects of the molecular biology of rice. PMID:9291974

  18. Molecular mechanisms regulating CD13-mediated adhesion

    PubMed Central

    Ghosh, Mallika; Gerber, Claire; Rahman, M Mamunur; Vernier, Kaitlyn M; Pereira, Flavia E; Subramani, Jaganathan; Caromile, Leslie A; Shapiro, Linda H

    2014-01-01

    CD13/Aminopeptidase N is a transmembrane metalloproteinase that is expressed in many tissues where it regulates various cellular functions. In inflammation, CD13 is expressed on myeloid cells, is up-regulated on endothelial cells at sites of inflammation and mediates monocyte/endothelial adhesion by homotypic interactions. In animal models the lack of CD13 alters the profiles of infiltrating inflammatory cells at sites of ischaemic injury. Here, we found that CD13 expression is enriched specifically on the pro-inflammatory subset of monocytes, suggesting that CD13 may regulate trafficking and function of specific subsets of immune cells. To further dissect the mechanisms regulating CD13-dependent trafficking we used the murine model of thioglycollate-induced sterile peritonitis. Peritoneal monocytes, macrophages and dendritic cells were significantly decreased in inflammatory exudates from global CD13KO animals when compared with wild-type controls. Furthermore, adoptive transfer of wild-type and CD13KO primary myeloid cells, or wild-type myeloid cells pre-treated with CD13-blocking antibodies into thioglycollate-challenged wild-type recipients demonstrated fewer CD13KO or treated cells in the lavage, suggesting that CD13 expression confers a competitive advantage in trafficking. Similarly, both wild-type and CD13KO cells were reduced in infiltrates in CD13KO recipients, confirming that both monocytic and endothelial CD13 contribute to trafficking. Finally, murine monocyte cell lines expressing mouse/human chimeric CD13 molecules demonstrated that the C-terminal domain of the protein mediates CD13 adhesion. Therefore, this work verifies that the altered inflammatory trafficking in CD13KO mice is the result of aberrant myeloid cell subset trafficking and further defines the molecular mechanisms underlying this regulation. PMID:24627994

  19. Cell-mediated immunity in nutritional deficiency.

    PubMed

    McMurray, D N

    1984-01-01

    Dietary deficiencies of specific nutrients profoundly alter cell-mediated immune responses in man and experimental animals. Both moderate and severe deficiencies are associated with significant changes in immunocompetence. Diets with inadequate levels of protein, calories, vitamin A, pyridoxine, biotin and zinc result in loss of thymic cellularity. Secondary to thymic atrophy, the production of thymic hormones critical for the differentiation of T lymphocytes is reduced, especially in protein-calorie malnutrition and zinc deficiency. Confirmation of a T cell maturational defect in nutritional deprivation comes from the observations of decreased total (T3 and rosette-forming) T cells in the peripheral blood of children with kwashiorkor and marasmus, with preferential loss of helper/inducer (T4) T cell subsets. Reduced number and in vitro function of T cells have also been reported in experimental deficiencies of iron, zinc, copper, and vitamins A and E. Loss of cutaneous hypersensitivity to mitogens and antigens is a consistent sequela of dietary deficiencies of protein, vitamins A and C, pyridoxine, iron and zinc. Cell-mediated immunity directed against allogeneic histocompatibility antigens (e.g. mixed leukocyte cultures, graft versus host, skin graft rejection) may actually be enhanced by experimental protein and polyunsaturated fat deficiencies. Alternatively, pyridoxine, ascorbate and biotin deficiencies resulted in delayed rejection of skin allografts. Cytotoxic T lymphocyte (CTL) activity is impaired in zinc-, iron- and copper-deficient mice, as well as in scorbutic guinea pigs. Natural killer (NK) cell function may be either enhanced or depressed, depending upon the nutrient and its effects on interferon production. Several authors have demonstrated normal or enhanced macrophage activity in a variety of experimental deficiencies. The extrapolation of these observations to infectious disease resistance is not straightforward, and depends upon the nature of

  20. Silver- and gold-mediated nucleobase bonding.

    PubMed

    Acioli, Paulo H; Srinivas, Sudha

    2014-08-01

    We report the results of a density functional theory investigation of the bonding of nucleobases mediated by silver and gold atoms in the gas phase. Our calculations use the Becke exchange and Perdew-Wang correlation functional (BPW91) combined with the Stuttgart effective core potentials to represent the valence electrons of gold, silver, and platinum, and the all-electron DGTZVP basis set for C, H, N, and O. This combination was chosen based on tests on the metal atoms and tautomers of adenine, cytosine, and guanine. To establish a benchmark to understand the metal-mediated bonding, we calculated the binding energy of each of the base pairs in their canonical forms. Our calculations show rather strong bonds between the Watson-Crick base pairs when compared with typical values for N-H-N and N-H-O hydrogen bonds. The neutral metal atoms tend to bond near the nitrogen atoms. The effect of the metal atoms on the bonding of nucleobases differs depending on whether or not the metal atoms bond to one of the hydrogen-bonding sites. When the silver or gold atoms bond to a non-hydrogen-bonding site, the effect is a slight enhancement of the cytosine-guanine bonding, but there is almost no effect on the adenine-thymine pairing. The metal atoms can block one of the hydrogen-bonding sites, thus preventing the normal cytosine-guanine and adenine-thymine pairings. We also find that both silver and gold can bond to consecutive guanines in a similar fashion to platinum, albeit with a significantly lower binding energy.

  1. Primary cilia signaling mediates intraocular pressure sensation.

    PubMed

    Luo, Na; Conwell, Michael D; Chen, Xingjuan; Kettenhofen, Christine Insinna; Westlake, Christopher J; Cantor, Louis B; Wells, Clark D; Weinreb, Robert N; Corson, Timothy W; Spandau, Dan F; Joos, Karen M; Iomini, Carlo; Obukhov, Alexander G; Sun, Yang

    2014-09-01

    Lowe syndrome is a rare X-linked congenital disease that presents with congenital cataracts and glaucoma, as well as renal and cerebral dysfunction. OCRL, an inositol polyphosphate 5-phosphatase, is mutated in Lowe syndrome. We previously showed that OCRL is involved in vesicular trafficking to the primary cilium. Primary cilia are sensory organelles on the surface of eukaryotic cells that mediate mechanotransduction in the kidney, brain, and bone. However, their potential role in the trabecular meshwork (TM) in the eye, which regulates intraocular pressure, is unknown. Here, we show that TM cells, which are defective in glaucoma, have primary cilia that are critical for response to pressure changes. Primary cilia in TM cells shorten in response to fluid flow and elevated hydrostatic pressure, and promote increased transcription of TNF-α, TGF-β, and GLI1 genes. Furthermore, OCRL is found to be required for primary cilia to respond to pressure stimulation. The interaction of OCRL with transient receptor potential vanilloid 4 (TRPV4), a ciliary mechanosensory channel, suggests that OCRL may act through regulation of this channel. A novel disease-causing OCRL allele prevents TRPV4-mediated calcium signaling. In addition, TRPV4 agonist GSK 1016790A treatment reduced intraocular pressure in mice; TRPV4 knockout animals exhibited elevated intraocular pressure and shortened cilia. Thus, mechanotransduction by primary cilia in TM cells is implicated in how the eye senses pressure changes and highlights OCRL and TRPV4 as attractive therapeutic targets for the treatment of glaucoma. Implications of OCRL and TRPV4 in primary cilia function may also shed light on mechanosensation in other organ systems.

  2. CFTR and sphingolipids mediate hypoxic pulmonary vasoconstriction

    PubMed Central

    Tabeling, Christoph; Yu, Hanpo; Wang, Liming; Ranke, Hannes; Goldenberg, Neil M.; Zabini, Diana; Noe, Elena; Krauszman, Adrienn; Gutbier, Birgitt; Yin, Jun; Schaefer, Michael; Arenz, Christoph; Hocke, Andreas C.; Suttorp, Norbert; Proia, Richard L.; Witzenrath, Martin; Kuebler, Wolfgang M.

    2015-01-01

    Hypoxic pulmonary vasoconstriction (HPV) optimizes pulmonary ventilation-perfusion matching in regional hypoxia, but promotes pulmonary hypertension in global hypoxia. Ventilation-perfusion mismatch is a major cause of hypoxemia in cystic fibrosis. We hypothesized that cystic fibrosis transmembrane conductance regulator (CFTR) may be critical in HPV, potentially by modulating the response to sphingolipids as mediators of HPV. HPV and ventilation-perfusion mismatch were analyzed in isolated mouse lungs or in vivo. Ca2+ mobilization and transient receptor potential canonical 6 (TRPC6) translocation were studied in human pulmonary (PASMCs) or coronary (CASMCs) artery smooth muscle cells. CFTR inhibition or deficiency diminished HPV and aggravated ventilation-perfusion mismatch. In PASMCs, hypoxia caused CFTR to interact with TRPC6, whereas CFTR inhibition attenuated hypoxia-induced TRPC6 translocation to caveolae and Ca2+ mobilization. Ca2+ mobilization by sphingosine-1-phosphate (S1P) was also attenuated by CFTR inhibition in PASMCs, but amplified in CASMCs. Inhibition of neutral sphingomyelinase (nSMase) blocked HPV, whereas exogenous nSMase caused TRPC6 translocation and vasoconstriction that were blocked by CFTR inhibition. nSMase- and hypoxia-induced vasoconstriction, yet not TRPC6 translocation, were blocked by inhibition or deficiency of sphingosine kinase 1 (SphK1) or antagonism of S1P receptors 2 and 4 (S1P2/4). S1P and nSMase had synergistic effects on pulmonary vasoconstriction that involved TRPC6, phospholipase C, and rho kinase. Our findings demonstrate a central role of CFTR and sphingolipids in HPV. Upon hypoxia, nSMase triggers TRPC6 translocation, which requires its interaction with CFTR. Concomitant SphK1-dependent formation of S1P and activation of S1P2/4 result in phospholipase C-mediated TRPC6 and rho kinase activation, which conjointly trigger vasoconstriction. PMID:25829545

  3. Opioid-induced immunosuppression: is it centrally mediated or peripherally mediated?

    PubMed

    Wei, Gang; Moss, Jonathan; Yuan, Chun Su

    2003-06-01

    Opioid compounds are commonly used pain medications. However, their administration is associated with a number of side-effects. Among them, opioid-induced immunosuppression is a significant medical problem, which is evidenced by a strong association between the use of opioids and exacerbated infections, including AIDS. Research data have demonstrated the effects of opioids to be suppressive on phagocytic, natural killer (NK), B and T cells. However, these immunosuppressive effects may be mediated by mechanisms different from those for antinociceptive actions. This article reviews possible central and peripheral mechanisms of opioid-induced immunosuppression. To the extent that peripherally mediated immunosuppressive effects play a significant role in opioid-induced immunosuppression, novel peripheral opioid antagonists may have a therapeutic role in attenuating opioid-induced immunosuppression without affecting analgesia.

  4. CD99 inhibits CD98-mediated β1 integrin signaling through SHP2-mediated FAK dephosphorylation.

    PubMed

    Lee, Kyoung Jin; Yoo, Yeon Ho; Kim, Min Seo; Yadav, Birendra Kumar; Kim, Yuri; Lim, Dongyoung; Hwangbo, Cheol; Moon, Ki Won; Kim, Daejoong; Jeoung, Dooil; Lee, Hansoo; Lee, Jeong-Hyung; Hahn, Jang-Hee

    2015-08-15

    The human CD99 protein is a 32-kDa type I transmembrane glycoprotein, while CD98 is a disulfide-linked 125-kDa heterodimeric type II transmembrane glycoprotein. It has been previously shown that CD99 and CD98 oppositely regulate β1 integrin signaling, though the mechanisms by which this regulation occurs are not known. Our results revealed that antibody-mediated crosslinking of CD98 induced FAK phosphorylation at Y397 and facilitated the formation of the protein kinase Cα (PKCα)-syntenin-focal adhesion kinase (FAK), focal adhesions (FAs), and IPP-Akt1-syntenin complex, which mediates β1 integrin signaling. In contrast, crosslinking of CD99 disrupted the formation of the PKCα-syntenin-FAK complex as well as FA via FAK dephosphorylation. The CD99-induced dephosphorylation of FAK was apparently mediated by the recruitment of Src homology region 2 domain-containing phosphatase-2 (SHP2) to the plasma membrane and subsequent activation of its phosphatase activity. Further consequences of the activation of SHP2 included the disruption of FAK-talin and talin-β1 integrin interactions and attenuation in the formation of the IPP-Akt1-syntenin complex at the plasma membrane, which resulted in reduced cell-ECM adhesion. This report uncovers the molecular mechanisms underlying the inverse regulation of β1 integrin signaling by CD99 and CD98 and may provide a novel therapeutic approach to treat inflammation and cancer.

  5. A General Multilevel SEM Framework for Assessing Multilevel Mediation

    ERIC Educational Resources Information Center

    Preacher, Kristopher J.; Zyphur, Michael J.; Zhang, Zhen

    2010-01-01

    Several methods for testing mediation hypotheses with 2-level nested data have been proposed by researchers using a multilevel modeling (MLM) paradigm. However, these MLM approaches do not accommodate mediation pathways with Level-2 outcomes and may produce conflated estimates of between- and within-level components of indirect effects. Moreover,…

  6. Demonstration of plasmid-mediated drug resistance in Mycobacterium abscessus.

    PubMed

    Matsumoto, Cristianne Kayoko; Bispo, Paulo José Martins; Santin, Katiane; Nogueira, Christiane Lourenço; Leão, Sylvia Cardoso

    2014-05-01

    Plasmid-mediated kanamycin resistance was detected in a strain of Mycobacterium abscessus subsp. bolletii responsible for a nationwide epidemic of surgical infections in Brazil. The plasmid did not influence susceptibility to tobramycin, streptomycin, trimethoprim-sulfamethoxazole, clarithromycin, or ciprofloxacin. Plasmid-mediated drug resistance has not been described so far in mycobacteria. PMID:24574286

  7. Special Education Mediations: Responding to a Proposal for Reform.

    ERIC Educational Resources Information Center

    Goldberg, Steven S.

    2001-01-01

    Responds to Jonathan Beyer's proposal in the January 1999 issue of this Journal (EJ583600) that traditional mediation would be useful for resolving special education disputes by formalizing the way that mediators are trained. Relying on empirical research, warns that Beyer's proposals for further quality controls and consequent formalization may…

  8. Clinicians as Communication Partners: Developing a Mediated Discourse Elicitation Protocol

    ERIC Educational Resources Information Center

    Hengst, Julie A.; Duff, Melissa C.

    2007-01-01

    This article presents the development and piloting of a mediated discourse elicitation protocol. Grounded in situated theories of communication and informed by mediated discourse analysis, this protocol selectively samples familiar discourse types in a manner designed to preserve interactional aspects of communication. Critically, the mediated…

  9. Digital Artistry and Mediation: (Re)mixing Music Education

    ERIC Educational Resources Information Center

    Vakeva, Lauri

    2012-01-01

    There is no doubt that mediation has become a central issue outside formal music education. An outstanding example of this is digital music and its dependence on the new technologies of production, dissemination, and consuming. In this paper, the author argues that (1) mediation is one of the most important aspects of digital artistry and that (2)…

  10. Implications of Mediated Instruction to Remote Learning in Mathematics.

    ERIC Educational Resources Information Center

    Matthews-Lopez, Joy L.; Lopez-Permouth, Sergio R.; Keck, David

    Mediated learning utilizes multimedia-based instructional modules to provide students with individualized access to information in alignment with their individual learning styles (Kinser, Morris, & Hewitt). In contrast with traditional pedagogy, the mission of the instructor in a mediated learning environment is to facilitate learning rather than…

  11. Technology mediator: a new role for the reference librarian?

    PubMed

    Howse, David K; Bracke, Paul J; Keim, Samuel M

    2006-01-01

    The Arizona Health Sciences Library has collaborated with clinical faculty to develop a federated search engine that is useful for meeting real-time clinical information needs. This article proposes a technology mediation role for the reference librarian that was inspired by the project, and describes the collaborative model used for developing technology-mediated services for targeted users.

  12. Peer-Mediated Teaching and Students with Learning Disabilities

    ERIC Educational Resources Information Center

    Harper, Gregory F.; Maheady, Larry

    2007-01-01

    Peer-mediated instruction holds particular promise as an effective educational strategy for children with learning disabilities. When properly implemented, peer-mediated instructional approaches permit active engagement, frequent opportunities to respond, immediate error correction, prompt feedback on the correctness of responses, and motivational…

  13. 45 CFR 400.83 - Mediation and fair hearings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Mediation and fair hearings. 400.83 Section 400.83 Public Welfare Regulations Relating to Public Welfare OFFICE OF REFUGEE RESETTLEMENT, ADMINISTRATION FOR... Employment § 400.83 Mediation and fair hearings. (a) Mediation—(1) Public/private RCA program. The State...

  14. Power Analysis for Complex Mediational Designs Using Monte Carlo Methods

    ERIC Educational Resources Information Center

    Thoemmes, Felix; MacKinnon, David P.; Reiser, Mark R.

    2010-01-01

    Applied researchers often include mediation effects in applications of advanced methods such as latent variable models and linear growth curve models. Guidance on how to estimate statistical power to detect mediation for these models has not yet been addressed in the literature. We describe a general framework for power analyses for complex…

  15. Addressing Moderated Mediation Hypotheses: Theory, Methods, and Prescriptions

    ERIC Educational Resources Information Center

    Preacher, Kristopher J.; Rucker, Derek D.; Hayes, Andrew F.

    2007-01-01

    This article provides researchers with a guide to properly construe and conduct analyses of conditional indirect effects, commonly known as moderated mediation effects. We disentangle conflicting definitions of moderated mediation and describe approaches for estimating and testing a variety of hypotheses involving conditional indirect effects. We…

  16. Technology mediator: a new role for the reference librarian?

    PubMed Central

    Howse, David K; Bracke, Paul J; Keim, Samuel M

    2006-01-01

    The Arizona Health Sciences Library has collaborated with clinical faculty to develop a federated search engine that is useful for meeting real-time clinical information needs. This article proposes a technology mediation role for the reference librarian that was inspired by the project, and describes the collaborative model used for developing technology-mediated services for targeted users. PMID:17040566

  17. School Processes Mediate School Compositional Effects: Model Specification and Estimation

    ERIC Educational Resources Information Center

    Liu, Hongqiang; Van Damme, Jan; Gielen, Sarah; Van Den Noortgate, Wim

    2015-01-01

    School composition effects have been consistently verified, but few studies ever attempted to study how school composition affects school achievement. Based on prior research findings, we employed multilevel mediation modeling to examine whether school processes mediate the effect of school composition upon school outcomes based on the data of 28…

  18. Considering Mediation for Special Education Disputes: A School Administrator's Perspective.

    ERIC Educational Resources Information Center

    Bar-Lev, Nissan B.; Neustadt, Sam; Peter, Marshall

    This pamphlet describes, from an administrators perspective, the advantages and disadvantages of mediation to solve special education disputes between parents and schools. It first notes mediation requirements under the 1997 reauthorization of the Individuals with Disabilities Act whenever a due process hearing has been requested, as well as…

  19. Teaching a Graduate Program Using Computer Mediated Conferencing Software.

    ERIC Educational Resources Information Center

    Wiesenberg, Faye; Hutton, Susan

    Two computer-mediated courses were developed and taught in an innovative master of continuing education program at the University of Calgary (Canada): Career Development in Organizational Settings and Leadership in Organizations. Within the context of the computer-mediated communication (CMC) system, the courses were structured in conferences…

  20. A Theory of Electronic Propinquity: Mediated Communication in Organizations.

    ERIC Educational Resources Information Center

    Korzenny, Felipe

    This paper proposes a theoretical approach to mediated communication in organizations. It is argued that the man/machine interface in mediated human communication is better dealt with when a comprehensive theoretical approach is used than when separate communication devices are tested as they appear in the market, such as video-teleconferencing.…