WorldWideScience

Sample records for cell edge protrusion

  1. Resting microglial cells exhibit tubular membrane protrusions

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    Ulrike Gimsa

    2002-11-01

    Full Text Available Nano- and microtubular structures have recently become a subject of increasing interest due to their importance in biology and medicine as well as their technological potential. Such structures have been observed in anorganic (Iijima, 1991 as well as in organic (Schnur 1993; Oda et al. 1991 systems. Micro- and nanotubular protrusions of bilayer membranes have been found in cells (Kralj-Iglic et al. 1998; Kralj-Iglic et al. 2001a and phospholipid vesicles (Kralj-Iglic et al. 2002; Kralj-Iglic et al. 2001b. In this work we describe membrane protrusions in microglial cells.

  2. Resting microglial cells exhibit tubular membrane protrusions

    OpenAIRE

    Ulrike Gimsa; Veronika Kralj-Iglic; Jan Gimsa; Ales Iglic

    2002-01-01

    Nano- and microtubular structures have recently become a subject of increasing interest due to their importance in biology and medicine as well as their technological potential. Such structures have been observed in anorganic (Iijima, 1991) as well as in organic (Schnur 1993; Oda et al. 1991) systems. Micro- and nanotubular protrusions of bilayer membranes have been found in cells (Kralj-Iglic et al. 1998; Kralj-Iglic et al. 2001a) and phospholipid vesicles (Kralj-Iglic et al. 2002; Kralj-Igl...

  3. Responses of tumor cell pseudopod protrusion to changes in medium osmolality.

    Science.gov (United States)

    You, J; Aznavoorian, S; Liotta, L A; Dong, C

    1996-04-01

    The potential involvement of osmotically generated force in protrusion of tumor cell pseudopods was examined during a micropipette assay. Experiments were performed on single A2058 melanoma cells activated by a micropipette filled with soluble type IV collagen. Previous observations suggested that tumor cell pseudopod protrusion induced by type IV collagen took place in distinct, separable phases: an initial bleb (first phase) caused by localized Ca2+-activated actin filament severing resulting in an osmotic flux followed by an extension with an irregular shape (second phase) which required G protein-mediated actin polymerization (Dong et al., 1994, Microvasc. Res., 47:55-67). Presently we studied cell pseudopod protrusion in response to the changes in chemoattractant osmolality. Reduction of attractant osmolality by 20-25% from its baseline value (297 mmol/ kg) resulted in an increase in pseudopod length by 50% apparent in the initial phase. Increases in attractant osmolality by 25-30% from the baseline value arrested pseudopod protrusion significantly during both initial and later phases. Using a dual-pipette method, such osmotic influence on the cell pseudopod protrusion was shown to be only a local effect in a small region where the cell surface was stimulated by the micropipette. While forces derived from actin polymerization and osmotic pressure have been proposed to cause protrusion in general, our results suggested that osmotically generated force is more apparent in the initial phase of the pseudopod formation. PMID:8698833

  4. Arp2/3 inhibition induces amoeboid-like protrusions in MCF10A epithelial cells by reduced cytoskeletal-membrane coupling and focal adhesion assembly.

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    Yvonne Beckham

    Full Text Available Here we demonstrate that Arp2/3 regulates a transition between mesenchymal and amoeboid protrusions in MCF10A epithelial cells. Using genetic and pharmacological means, we first show Arp2/3 inhibition impairs directed cell migration. Arp2/3 inhibition results in a dramatically impaired cell adhesion, causing deficient cell attachment and spreading to ECM as well as an 8-fold decrease in nascent adhesion assembly at the leading edge. While Arp2/3 does not play a significant role in myosin-dependent adhesion growth, mature focal adhesions undergo large scale movements against the ECM suggesting reduced coupling to the ECM. Cell edge protrusions occur at similar rates when Arp2/3 is inhibited but their morphology is dramatically altered. Persistent lamellipodia are abrogated and we observe a markedly increased incidence of blebbing and unstable pseuodopods. Micropipette-aspiration assays indicate that Arp2/3-inhibited cells have a weak coupling between the cell cortex and the plasma membrane, and suggest a potential mechanism for increased pseudopod and bleb formation. Pseudopods are not sensitive to reduced in formin or myosin II activity. Collectively, these results indicate that Arp2/3 is not necessary for rapid protrusion of the cell edge but plays a crucial role in assembling focal adhesions required for its stabilization.

  5. The diaphanous-related formins promote protrusion formation and cell-to-cell spread of Listeria monocytogenes.

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    Fattouh, Ramzi; Kwon, Hyunwoo; Czuczman, Mark A; Copeland, John W; Pelletier, Laurence; Quinlan, Margot E; Muise, Aleixo M; Higgins, Darren E; Brumell, John H

    2015-04-01

    The Gram-positive bacterium Listeria monocytogenes is a facultative intracellular pathogen whose virulence depends on its ability to spread from cell to cell within an infected host. Although the actin-related protein 2/3 (Arp2/3) complex is necessary and sufficient for Listeria actin tail assembly, previous studies suggest that other actin polymerization factors, such as formins, may participate in protrusion formation. Here, we show that Arp2/3 localized to only a minor portion of the protrusion. Moreover, treatment of L. monocytogenes-infected HeLa cells with a formin FH2-domain inhibitor significantly reduced protrusion length. In addition, the Diaphanous-related formins 1-3 (mDia1-3) localized to protrusions, and knockdown of mDia1, mDia2, and mDia3 substantially decreased cell-to-cell spread of L. monocytogenes. Rho GTPases are known to be involved in formin activation. Our studies also show that knockdown of several Rho family members significantly influenced bacterial cell-to-cell spread. Collectively, these findings identify a Rho GTPase-formin network that is critically involved in the cell-to-cell spread of L. monocytogenes. PMID:25281757

  6. Local anesthetics inhibit kinesin motility and microtentacle protrusions in human epithelial and breast tumor cells.

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    Yoon, Jennifer R; Whipple, Rebecca A; Balzer, Eric M; Cho, Edward H; Matrone, Michael A; Peckham, Michelle; Martin, Stuart S

    2011-10-01

    Detached breast tumor cells produce dynamic microtubule protrusions that promote reattachment of cells and are termed tubulin microtentacles (McTNs) due to their mechanistic distinctions from actin-based filopodia/invadopodia and tubulin-based cilia. McTNs are enriched with vimentin and detyrosinated α-tubulin, (Glu-tubulin). Evidence suggests that vimentin and Glu-tubulin are cross-linked by kinesin motor proteins. Using known kinesin inhibitors, Lidocaine and Tetracaine, the roles of kinesins in McTN formation and function were tested. Live-cell McTN counts, adhesion assays, immunofluorescence, and video microscopy were performed to visualize inhibitor effects on McTNs. Viability and apoptosis assays were used to confirm the non-toxicity of the inhibitors. Treatments of human non-tumorigenic mammary epithelial and breast tumor cells with Lidocaine or Tetracaine caused rapid collapse of vimentin filaments. Live-cell video microscopy demonstrated that Tetracaine reduces motility of intracellular GFP-kinesin and causes centripetal collapse of McTNs. Treatment with Tetracaine inhibited the extension of McTNs and their ability to promote tumor cell aggregation and reattachment. Lidocaine showed similar effects but to a lesser degree. Our current data support a model in which the inhibition of kinesin motor proteins by Tetracaine leads to the reductions in McTNs, and provides a novel mechanism for the ability of this anesthetic to decrease metastatic progression. PMID:21069453

  7. The Diaphanous-Related Formins Promote Protrusion Formation and Cell-to-Cell Spread of Listeria monocytogenes

    OpenAIRE

    Fattouh, Ramzi; Kwon, Hyunwoo; Czuczman, Mark A.; Copeland, John W.; Pelletier, Laurence; Quinlan, Margot E.; Aleixo M Muise; Higgins, Darren E.; Brumell, John H.

    2014-01-01

    The Gram-positive bacterium Listeria monocytogenes is a facultative intracellular pathogen whose virulence depends on its ability to spread from cell to cell within an infected host. Although the actin-related protein 2/3 (Arp2/3) complex is necessary and sufficient for Listeria actin tail assembly, previous studies suggest that other actin polymerization factors, such as formins, may participate in protrusion formation. Here, we show that Arp2/3 localized to only a minor portion of the protr...

  8. Pericellular Hyaluronan Coat Visualized in Live Cells With a Fluorescent Probe Is Scaffolded by Plasma Membrane Protrusions

    OpenAIRE

    Rilla, Kirsi; Tiihonen, Riikka; Kultti, Anne; Tammi, Markku; Tammi, Raija

    2008-01-01

    Many cell types wear up to 20-μm-wide hyaluronidase-sensitive surface coats, detected by exclusion of sedimenting particles like fixed erythrocytes. The structure of the coat is enigmatic, being apparently too thick to be accounted by random coils or even extended chains of just hyaluronan attached to cell surface. We have shown that hyaluronan synthesis enforced by green fluorescent protein–hyaluronan synthase transfection creates microvillous protrusions. The idea that the plasma membrane p...

  9. Direct RNA sequencing mediated identification of mRNA localized in protrusions of human MDA-MB-231 metastatic breast cancer cells

    DEFF Research Database (Denmark)

    Jakobsen, Kristine Raaby; Sørensen, Emilie; Brøndum, Karin Kathrine;

    2013-01-01

    To describe genome wide RNA localized in protrusions of the metastatic human breast cancer cell line MDA-MB-231 we used Boyden chamber based methodology followed by direct mRNA sequencing. Results In the hereby identified group of protrusion localized mRNA some previously were described to be...... localized exemplified by mRNA for Ras-Related protein 13 (RAB13) and p0071 (Plakophilin-4/PKP4). For other transcripts, exemplified by mRNA for SH3PXD2A/TKS5 and PPFIA1/Liprin-α1, only the corresponding proteins previously were described to have protrusion localization. Finally, a cohort of MDA-MB-231...... protrusion localized transcripts represents novel candidates to mediate cancer cell subcellular region specific functions through mRNA direction to protrusions. We included a further characterization of p0071, an armadillo repeat protein of adherence junctions and desmosomes, in MDA-MB-231 and non...

  10. Independent Interactions of Phosphorylated β-Catenin with E-Cadherin at Cell-Cell Contacts and APC at Cell Protrusions

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    Faux, Maree C.; Coates, Janine L; Kershaw, Nadia J.; Layton, Meredith J.; Burgess, Antony W.

    2010-01-01

    Background The APC tumour suppressor functions in several cellular processes including the regulation of β-catenin in Wnt signalling and in cell adhesion and migration. Findings In this study, we establish that in epithelial cells N-terminally phosphorylated β-catenin specifically localises to several subcellular sites including cell-cell contacts and the ends of cell protrusions. N-terminally phosphorylated β-catenin associates with E-cadherin at adherens junctions and with APC in cell protr...

  11. Epithelial-mesenchymal transition stimulates human cancer cells to extend microtubule-based invasive protrusions and suppresses cell growth in collagen gel.

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    Jun Oyanagi

    Full Text Available Epithelial-mesenchymal transition (EMT is a crucial event in tumor invasion and metastasis. However, most of past EMT studies have been conducted in the conventional two-dimensional (2D monolayer culture. Therefore, it remains unclear what invasive phenotypes are acquired by EMT-induced cancer cells. To address this point, we attempted to characterize EMT cells in more physiological, three-dimensional (3D collagen gel culture. EMT was induced by treating three human carcinoma cell lines (A549, Panc-1 and MKN-1 with TGF-ß. The TGF-ß treatment stimulated these cells to overexpress the invasion markers laminin γ2 and MT1-MMP in 2D culture, in addition to the induction of well-known morphological change and EMT marker expression. EMT induction enhanced cell motility and adhesiveness to fibronectin and collagen in 2D culture. Although EMT cells showed comparable cell growth to control cells in 2D culture, their growth rates were extremely suppressed in soft agar and collagen gel cultures. Most characteristically, EMT-induced cancer cells commonly and markedly extended invasive protrusions in collagen gel. These protrusions were mainly supported by microtubules rather than actin cytoskeleton. Snail-introduced, stable EMT cells showed similar protrusions in 3D conditions without TGF-ß. Moreover, these protrusions were suppressed by colchicine or inhibitors of heat shock protein 90 (HSP-90 and protein phosphatase 2A. However, MMP inhibitors did not suppress the protrusion formation. These data suggest that EMT enhances tumor cell infiltration into interstitial stroma by extending microtubule-based protrusions and suppressing cell growth. The elevated cell adhesion to fibronectin and collagen and high cell motility also seem important for the tumor invasion.

  12. Three-dimensional matrix fiber alignment modulates cell migration and MT1-MMP utility by spatially and temporally directing protrusions

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    Fraley, Stephanie I.; Wu, Pei-Hsun; He, Lijuan; Feng, Yunfeng; Krisnamurthy, Ranjini; Longmore, Gregory D.; Wirtz, Denis

    2015-10-01

    Multiple attributes of the three-dimensional (3D) extracellular matrix (ECM) have been independently implicated as regulators of cell motility, including pore size, crosslink density, structural organization, and stiffness. However, these parameters cannot be independently varied within a complex 3D ECM protein network. We present an integrated, quantitative study of these parameters across a broad range of complex matrix configurations using self-assembling 3D collagen and show how each parameter relates to the others and to cell motility. Increasing collagen density resulted in a decrease and then an increase in both pore size and fiber alignment, which both correlated significantly with cell motility but not bulk matrix stiffness within the range tested. However, using the crosslinking enzyme Transglutaminase II to alter microstructure independently of density revealed that motility is most significantly predicted by fiber alignment. Cellular protrusion rate, protrusion orientation, speed of migration, and invasion distance showed coupled biphasic responses to increasing collagen density not predicted by 2D models or by stiffness, but instead by fiber alignment. The requirement of matrix metalloproteinase (MMP) activity was also observed to depend on microstructure, and a threshold of MMP utility was identified. Our results suggest that fiber topography guides protrusions and thereby MMP activity and motility.

  13. APC/β-catenin-rich complexes at membrane protrusions regulate mammary tumor cell migration and mesenchymal morphology

    International Nuclear Information System (INIS)

    The APC tumor suppressor is mutated or downregulated in many tumor types, and is prominently localized to punctate clusters at protrusion tips in migratory cells, such as in astrocytes where it has been implicated in directed cell motility. Although APC loss is considered an initiating event in colorectal cancer, for example, it is less clear what role APC plays in tumor cell motility and whether loss of APC might be an important promoter of tumor progression in addition to initiation. The localization of APC and β-catenin was analyzed in multiple cell lines, including non-transformed epithelial lines treated with a proteasome inhibitor or TGFβ to induce an epithelial-to-mesenchymal transition (EMT), as well as several breast cancer lines, by immunofluorescence. APC expression was knocked down in 4T07 mammary tumor cells using lentiviral-mediated delivery of APC-specific short-hairpin (sh) RNAs, and assessed using quantitative (q) reverse-transcriptase (RT)-PCR and western blotting. Tumor cell motility was analyzed by performing wound-filling assays, and morphology via immunofluorescence (IF) and phase-contrast microscopy. Additionally, proliferation was measured using BrdU incorporation, and TCF reporter assays were performed to determine β-catenin/TCF-mediated transcriptional activity. APC/β-catenin-rich complexes were observed at protrusion ends of migratory epithelial cells treated with a proteasome inhibitor or when EMT has been induced and in tumor cells with a mesenchymal, spindle-like morphology. 4T07 tumor cells with reduced APC levels were significantly less motile and had a more rounded morphology; yet, they did not differ significantly in proliferation or β-catenin/TCF transcriptional activity. Furthermore, we found that APC/β-catenin-rich complexes at protrusion ends were dependent upon an intact microtubule cytoskeleton. These findings indicate that membrane protrusions with APC/β-catenin-containing puncta control the migratory potential and

  14. Potassium-chloride cotransporter 3 interacts with Vav2 to synchronize the cell volume decrease response with cell protrusion dynamics.

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    Adèle Salin-Cantegrel

    Full Text Available Loss-of-function of the potassium-chloride cotransporter 3 (KCC3 causes hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC, a severe neurodegenerative disease associated with defective midline crossing of commissural axons in the brain. Conversely, KCC3 over-expression in breast, ovarian and cervical cancer is associated with enhanced tumor cell malignancy and invasiveness. We identified a highly conserved proline-rich sequence within the C-terminus of the cotransporter which when mutated leads to loss of the KCC3-dependent regulatory volume decrease (RVD response in Xenopus Laevis oocytes. Using SH3 domain arrays, we found that this poly-proline motif is a binding site for SH3-domain containing proteins in vitro. This approach identified the guanine nucleotide exchange factor (GEF Vav2 as a candidate partner for KCC3. KCC3/Vav2 physical interaction was confirmed using GST-pull down assays and immuno-based experiments. In cultured cervical cancer cells, KCC3 co-localized with the active form of Vav2 in swelling-induced actin-rich protruding sites and within lamellipodia of spreading and migrating cells. These data provide evidence of a molecular and functional link between the potassium-chloride co-transporters and the Rho GTPase-dependent actin remodeling machinery in RVD, cell spreading and cell protrusion dynamics, thus providing new insights into KCC3's involvement in cancer cell malignancy and in corpus callosum agenesis in HMSN/ACC.

  15. Predicted solar cell edge radiation effects

    International Nuclear Information System (INIS)

    The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT

  16. Lipid tail protrusions mediate the insertion of nanoparticles into model cell membranes.

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    Van Lehn, Reid C; Ricci, Maria; Silva, Paulo H J; Andreozzi, Patrizia; Reguera, Javier; Voïtchovsky, Kislon; Stellacci, Francesco; Alexander-Katz, Alfredo

    2014-01-01

    Recent work has demonstrated that charged gold nanoparticles (AuNPs) protected by an amphiphilic organic monolayer can spontaneously insert into the core of lipid bilayers to minimize the exposure of hydrophobic surface area to water. However, the kinetic pathway to reach the thermodynamically stable transmembrane configuration is unknown. Here, we use unbiased atomistic simulations to show the pathway by which AuNPs spontaneously insert into bilayers and confirm the results experimentally on supported lipid bilayers. The critical step during this process is hydrophobic-hydrophobic contact between the core of the bilayer and the monolayer of the AuNP that requires the stochastic protrusion of an aliphatic lipid tail into solution. This last phenomenon is enhanced in the presence of high bilayer curvature and closely resembles the putative pre-stalk transition state for vesicle fusion. To the best of our knowledge, this work provides the first demonstration of vesicle fusion-like behaviour in an amphiphilic nanoparticle system. PMID:25042518

  17. Endothelial Surface Protrusion by a Point Force.

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    Chen, Yong; Lu, Lan; Shao, Jin-Yu

    2016-03-01

    During leukocyte rolling on the endothelium, surface protrusion and membrane tether extraction occur consecutively on leukocytes. Both surface protrusion and tether extraction of leukocytes stabilize leukocyte rolling. Tethers can also be extracted from endothelial cells (ECs), but surface protrusion of ECs has never been confirmed to exist. In this study, we examined EC surface protrusion with the micropipette aspiration technique. We found that, like leukocytes, surface protrusion on an EC did exist when a point force was imposed. Both the protrusional stiffness and the crossover force of EC surface protrusion were dependent on the force loading rate and the cytoskeletal integrity, but neither of them was dependent on tumor necrosis factor α stimulation. Temperature (37°C) affected the protrusional stiffness only at small force loading rates. When a neutrophil was employed to directly impose the pulling force on the EC, simultaneous surface protrusion from both cells occurred, and it can be modeled as two springs connected in series, although the spring constants should be adjusted according to the force loading rate. Therefore, EC surface protrusion is an important aspect of leukocyte rolling, and it should not be ignored when leukocyte rolling stability is studied systematically. PMID:26958891

  18. The Protrusive Phase and Full Development of Integrin-Dependent Adhesions in Colon Epithelial Cells Require FAK- and ERKMediated Actin Spike Formation: Deregulation in Cancer Cells

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    Valerie G. Brunton

    2001-01-01

    Full Text Available Integrins play an important role in tumour progression by influencing cellular responses and matrix-dependent adhesion. However, the regulation of matrix-dependent adhesion assembly in epithelial cells is poorly understood. We have investigated the integrin and signalling requirements of cell-matrix adhesion assembly in colon carcinoma cells after plating on fibronectin. Adhesion assembly in these, and in the adenoma cells from which they were derived, was largely dependent on αvβ6 integrin and required phosphorylation of FAK on tyrosine-397. The rate of fibronectin-induced adhesion assembly and the expression of both αvβ6 integrin and FAK were increased during the adenoma-to-carcinoma transition. The matrix-dependent adhesion assembly process, particularly the final stages of complex protrusion that is required for optimal cell spreading, required the activity of extracellular signal-regulated kinase (ERK. Furthermore, phosphorylated ERK was targeted to newly forming cell-matrix adhesions in the carcinoma cells but not the adenoma cells, and inhibition of FAK-tyrosine-397 phosphorylation or MEK suppressed the appearance of phosphorylated ERK at peripheral sites. In addition, inhibition of MEK-ERK activation blocked the formation of peripheral actin microspikes that were necessary for the protrusive phase of cell-matrix adhesion assembly. Thus, MEK-ERK-dependent peripheral actin re-organization is required for the full development of integrin-induced adhesions and this pathway is stimulated in an in vitro model of colon cancer progression.

  19. Increased cellular apoptosis susceptibility (CSE1L/CAS) protein expression promotes protrusion extension and enhances migration of MCF-7 breast cancer cells

    International Nuclear Information System (INIS)

    Microtubules are part of cell structures that play a role in regulating the migration of cancer cells. The cellular apoptosis susceptibility (CSE1L/CAS) protein is a microtubule-associated protein that is highly expressed in cancer. We report here that CSE1L regulates the association of α-tubulin with β-tubulin and promotes the migration of MCF-7 breast cancer cells. CSE1L was associated with α-tubulin and β-tubulin in GST (glutathione S-transferase) pull-down and immunoprecipitation assays. CSE1L-GFP (green fluorescence protein) fusion protein experiments showed that the N-terminal of CSE1L interacted with microtubules. Increased CSE1L expression resulted in decreased tyrosine phosphorylation of α-tubulin and β-tubulin, increased α-tubulin and β-tubulin association, and enhanced assembly of microtubules. Cell protrusions or pseudopodia are temporary extensions of the plasma membrane and are implicated in cancer cell migration and invasion. Increased CSE1L expression increased the extension of MCF-7 cell protrusions. In vitro migration assay showed that enhanced CSE1L expression increased the migration of MCF-7 cells. Our results indicate that CSE1L plays a role in regulating the extension of cell protrusions and promotes the migration of cancer cells.

  20. Changing gears from chemical adhesion of cells to flat substrata toward engulfment of micro-protrusions by active mechanisms

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    Hai, Aviad; Kamber, Dotan; Malkinson, Guy; Erez, Hadas; Mazurski, Noa; Shappir, Joseph; Spira, Micha E.

    2009-12-01

    Microelectrode arrays increasingly serve to extracellularly record in parallel electrical activity from many excitable cells without inflicting damage to the cells by insertion of microelectrodes. Nevertheless, apart from rare cases they suffer from a low signal to noise ratio. The limiting factor for effective electrical coupling is the low seal resistance formed between the plasma membrane and the electronic device. Using transmission electron microscope analysis we recently reported that cultured Aplysia neurons engulf protruding micron size gold spines forming tight apposition which significantly improves the electrical coupling in comparison with flat electrodes (Hai et al 2009 Spine-shaped gold protrusions improve the adherence and electrical coupling of neurons with the surface of micro-electronic devices J. R. Soc. Interface 6 1153-65). However, the use of a transmission electron microscope to measure the extracellular cleft formed between the plasma membrane and the gold-spine surface may be inaccurate as chemical fixation may generate structural artifacts. Using live confocal microscope imaging we report here that cultured Aplysia neurons engulf protruding spine-shaped gold structures functionalized by an RGD-based peptide and to a significantly lesser extent by poly-l-lysine. The cytoskeletal elements actin and associated protein cortactin are shown to organize around the stalks of the engulfed gold spines in the form of rings. Neurons grown on the gold-spine matrix display varying growth patterns but maintain normal electrophysiological properties and form functioning synapses. It is concluded that the matrices of functionalized gold spines provide an improved substrate for the assembly of neuro-electronic hybrids.

  1. ELMO recruits actin cross-linking family 7 (ACF7) at the cell membrane for microtubule capture and stabilization of cellular protrusions.

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    Margaron, Yoran; Fradet, Nadine; Côté, Jean-François

    2013-01-11

    ELMO and DOCK180 proteins form an evolutionarily conserved module controlling Rac GTPase signaling during cell migration, phagocytosis, and myoblast fusion. Here, we identified the microtubule and actin-binding spectraplakin ACF7 as a novel ELMO-interacting partner. A C-terminal polyproline segment in ELMO and the last spectrin repeat of ACF7 mediate a direct interaction between these proteins. Co-expression of ELMO1 with ACF7 promoted the formation of long membrane protrusions during integrin-mediated cell spreading. Quantification of membrane dynamics established that coupling of ELMO and ACF7 increases the persistence of the protruding activity. Mechanistically, we uncovered a role for ELMO in the recruitment of ACF7 to the membrane to promote microtubule capture and stability. Functionally, these effects of ELMO and ACF7 on cytoskeletal dynamics required the Rac GEF DOCK180. In conclusion, our findings support a role for ELMO in protrusion stability by acting at the interface between the actin cytoskeleton and the microtubule network. PMID:23184944

  2. On the existence and strength of stable membrane protrusions

    International Nuclear Information System (INIS)

    We present a mathematical model for the protrusion of lamellipodia in motile cells. The model lamellipodium consists of a viscoelastic actin gel in the bulk and a dynamic boundary layer of newly polymerized filaments at the leading edge called the semiflexible region (SR). The density of filaments in the SR can increase due to nucleation of new filaments and decrease due to capping and severing of existing filaments. Following on from previous publications, we present important approximations that make the model feasible and accessible to fast computational analysis. It reveals that there are three qualitatively different parameter regimes: a stable, stationarily protruding lamellipodium; a stable lamellipodium showing oscillatory motion of the leading edge; and zero filament density and no stable lamellipodium. Hence, the model defines criteria for the existence of lamellipodia and the ability of cells to move effectively, and we discuss which parameter changes can induce transitions between the different states. Furthermore, stable lamellipodia have to be able to exert and withstand substantial forces. We can fit the experimentally measured dynamic force–velocity relation that describes how cells can adapt to increasing external forces when encountering an obstacle in their environment during motion. Moreover, we predict a different stationary force–velocity relation that should apply if cells experience a constant force, e.g. exerted by the surrounding tissue. (paper)

  3. Roles of WIP and WICH/WIRE proteins in formation and maturation of invasive protrusions in human breast cancer cells

    OpenAIRE

    García González, Esther

    2014-01-01

    Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 14-03-2014 Metastasis is a multistep process wherein cancer cells separate from the primary tumour, cross the surrounding extracellular matrix (ECM), and disperse throughout the body to reach distant tissues where they proliferate and establish themselves as a secondary tumour. Metastasis involves several intracellular processes including s...

  4. Spontaneously disappearing lumbar disc protrusion

    OpenAIRE

    Ushewokunze, Shungu; Abbas, Naeem; Dardis, Ronan; Killeen, Ian

    2008-01-01

    Spontaneous disappearance of a herniated lumbar disc is known to occur. This case study describes a 45-year-old patient whose symptoms of lumbar radiculopathy resolved and follow-up imaging showed complete disappearance of the disc prolapse. This phenomenon strengthens the role of conservative treatment in the management of lumbar disc protrusions.

  5. Cell-Edge Multi-User Relaying with Overhearing

    DEFF Research Database (Denmark)

    Sun, Fan; Kim, Tae Min; Paulraj, Arogyaswami;

    2013-01-01

    Carefully designed protocols can turn overheard interference into useful side information to allow simultaneous transmission of multiple communication flows and increase the spectral efficiency in interference-limited regime. In this letter, we propose a novel scheme in a typical cell-edge scenario...

  6. Minimal model for spontaneous cell polarization and edge activity in oscillating, rotating and migrating cells

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    Raynaud, Franck; Ambühl, Mark E.; Gabella, Chiara; Bornert, Alicia; Sbalzarini, Ivo F.; Meister, Jean-Jacques; Verkhovsky, Alexander B.

    2016-04-01

    How cells break symmetry and organize activity at their edges to move directionally is a fundamental question in cell biology. Physical models of cell motility commonly incorporate gradients of regulatory proteins and/or feedback from the motion itself to describe the polarization of this edge activity. These approaches, however, fail to explain cell behaviour before the onset of polarization. We use polarizing and moving fish epidermal cells as a model system to bridge the gap between cell behaviours before and after polarization. Our analysis suggests a novel and simple principle of self-organizing cell activity, in which local cell-edge dynamics depends on the distance from the cell centre, but not on the orientation with respect to the front-back axis. We validate this principle with a stochastic model that faithfully reproduces a range of cell-migration behaviours. Our findings indicate that spontaneous polarization, persistent motion and cell shape are emergent properties of the local cell-edge dynamics controlled by the distance from the cell centre.

  7. Protrusive and Contractile Forces of Spreading Human Neutrophils.

    Science.gov (United States)

    Henry, Steven J; Chen, Christopher S; Crocker, John C; Hammer, Daniel A

    2015-08-18

    Human neutrophils are mediators of innate immunity and undergo dramatic shape changes at all stages of their functional life cycle. In this work, we quantified the forces associated with a neutrophil's morphological transition from a nonadherent, quiescent sphere to its adherent and spread state. We did this by tracking, with high spatial and temporal resolution, the cell's mechanical behavior during spreading on microfabricated post-array detectors printed with the extracellular matrix protein fibronectin. Two dominant mechanical regimes were observed: transient protrusion and steady-state contraction. During spreading, a wave of protrusive force (75 ± 8 pN/post) propagates radially outward from the cell center at a speed of 206 ± 28 nm/s. Once completed, the cells enter a sustained contractile state. Although post engagement during contraction was continuously varying, posts within the core of the contact zone were less contractile (-20 ± 10 pN/post) than those residing at the geometric perimeter (-106 ± 10 pN/post). The magnitude of the protrusive force was found to be unchanged in response to cytoskeletal inhibitors of lamellipodium formation and myosin II-mediated contractility. However, cytochalasin B, known to reduce cortical tension in neutrophils, slowed spreading velocity (61 ± 37 nm/s) without significantly reducing protrusive force. Relaxation of the actin cortical shell was a prerequisite for spreading on post arrays as demonstrated by stiffening in response to jasplakinolide and the abrogation of spreading. ROCK and myosin II inhibition reduced long-term contractility. Function blocking antibody studies revealed haptokinetic spreading was induced by β2 integrin ligation. Neutrophils were found to moderately invaginate the post arrays to a depth of ∼1 μm as measured from spinning disk confocal microscopy. Our work suggests a competition of adhesion energy, cortical tension, and the relaxation of cortical tension is at play at the onset of

  8. Morphological change of self-organized protrusions of fluoropolymer surface by ion beam irradiation

    International Nuclear Information System (INIS)

    Polytetrafluoroethylene (PTFE) and fluorinated ethylene propylene (FEP) are typical fluoropolymers displaying several desirable technological properties such as electrical insulation and high chemical resistance. When their surfaces are irradiated with ion beams, dense micro-protrusions formed after the emergence and spread of micropores across the entire irradiated area, allowing culture cells to spread on the top of the protrusions. In this study, we investigate the morphological changes introduced in the fluoropolymer surfaces by ion beams as the energy of the beams is increased. When an FEP sample was irradiated with a nitrogen ion beam with an energy of less than 350 keV at 1.0 μA/cm2, protrusions were formed with a density between 2 × 107/cm2 and 2 × 108/cm2. However, at energies higher than 350 keV, the protrusions became sparse, and the density dropped to 5 × 102/cm2. Protrusions appeared sporadically during irradiation at high energies, and the top of the protrusions appeared as spots inside the sample, which were difficult to etch and became elongated as the erosion of the surface progressed. Erosion was caused by sputtering of FEP molecules and evaporation at notably elevated temperatures on the surface. Analysis based on attenuated total reflectance/Fourier transform infrared spectroscopy showed the presence of C=C bonds as well as –COOH, –C=O, and –OH bonds on all irradiated samples. Their concentration on the surface densely covered with micro-protrusions was higher than that on the surface with sparse protrusions after irradiation at energies exceeding 350 keV. Thus, we determined a suitable range for the ion energy for creating FEP surfaces densely covered with protrusions

  9. Effect of Temperature on Tether Extraction, Surface Protrusion, and Cortical Tension of Human Neutrophils

    OpenAIRE

    Liu, Baoyu; Goergen, Craig J.; Shao, Jin-Yu

    2007-01-01

    Neutrophil rolling on endothelial cells, the initial stage of its migrational journey to a site of inflammation, is facilitated by tether extraction and surface protrusion. Both phenomena have been studied extensively at room temperature, which is considerably lower than human body temperature. It is known that temperature greatly affects cellular mechanical properties such as viscosity. Therefore, we carried out tether extraction, surface protrusion, and cortical tension experiments at 37°C ...

  10. ICRF-driven convective cells in the tokamak edge plasma

    International Nuclear Information System (INIS)

    Recently, the authors have shown that the release of metal impurities during ICRF heating on JET could be explained by ion acceleration into the Faraday screen (FS) surface caused by rf sheaths, which form when local magnetic field is imperfectly aligned with the FS. The theory explained many of the dependences of the impurity data, including the virtual elimination of impurities with beryllium screens and dipole antenna phasing. The good agreement between the impurity generation model and experimental data can be taken as evidence of the relevance of rf sheaths to the scrape-off-layer (SOL) plasma in tokamaks. A crucial physical point in sheath theory is that the requirement of no time-averaged current into the boundary leads to the rectification of the oscillating rf fields to produce a net time-averaged and spatially-varying potential and, hence, a DC electric field. Here, the authors investigate the possibility that the rectified sheath potential Φo can drive convective cells in the SOL which may explain the experimental observations of ICRF-enhanced edge transport on many tokamaks. Temperature (and sometimes density) profile flattening and induced DC electric fields in the SOL are often observed during ICRF heating on JET, particularly in monopole phasing. The attainment of the H-mode with ICRF heating alone is also sensitive to the phasing of the antenna. These observations suggest an rf-sheath related effect, as the magnitude of Φo is much larger in monopole phasing (∼1 kV near the FS). The authors speculate that enhanced edge cooling by rapid convection may account for the phasing sensitivity of the H-mode transition. In the present work, a modified convective cell equation for the SOL plasma is derived, which explicitly takes into account the finite length of the field lines and the appropriate sheath boundary condition for Jparallel

  11. Transanal protrusion of intussusceptions in children

    Directory of Open Access Journals (Sweden)

    Ezomike Uchechukwu Obiora

    2014-01-01

    Full Text Available Background: The aim of the following study is to report our management experience and outcome of transanal protrusion of intussusceptions. Patients and Methods: Retrospective analysis of all cases of intussusceptions protruding through the anal opening from January 2008 to June 2013. Results: Of 62 cases of intussusceptions, transanal protrusion occurred in 10 patients (16% anal protrusion rate with a male:female ratio of 2:3. They were aged 4-96 months (mean 22.6 ± 30.7, median 7.5 months. Six were infants while four were above 1 year. Duration of symptoms ranged from 2 to 14 days (mean 5.9 days ± 3.4 with only two patients presenting within 48 h. Clinical features included vomiting (100%, abdominal pains (100%, bloody mucoid stool (100%, abdominal distension (90%, and palpable left iliac fossa mass (70%. Three patients had preceding diarrhoea (30% and two had preceding upper respiratory tract infection (20%. Duration of hospital stay ranged from 5 to 23 days (mean 12 days ± 5.6. Findings at surgery included seven ileocolic and two colocolic intussusceptions (one patient died before surgery. Operative procedures were right hemicolectomy (5, operative manual reduction (3, left hemicolectomy (1 giving a 67% bowel resection rate. One patient died giving a 10% mortality rate. Conclusion: Transanal protrusion occurred more in females and is associated with late presentation, older age, high bowel resection rate, and high mortality.

  12. Lipid protrusions membrane softness, and enzymatic activity

    DEFF Research Database (Denmark)

    Jensen, Morten Østergaard; Høyrup, P.; Callisen, T.H.;

    2004-01-01

    protrusion modes and mechanical softness of phospholipid bilayers and on the other side the activity of enzymes acting on lipid bilayers composed of different unsaturated lipids. Specifically, our experiments show a correlation between the bilayer bending rigidity and the apparent Arrhenius activation energy...

  13. Septins guide microtubule protrusions induced by actin-depolymerizing toxins like Clostridium difficile transferase (CDT).

    Science.gov (United States)

    Nölke, Thilo; Schwan, Carsten; Lehmann, Friederike; Østevold, Kristine; Pertz, Olivier; Aktories, Klaus

    2016-07-12

    Hypervirulent Clostridium difficile strains, which are associated with increased morbidity and mortality, produce the actin-ADP ribosylating toxin Clostridium difficile transferase (CDT). CDT depolymerizes actin, causes formation of microtubule-based protrusions, and increases pathogen adherence. Here, we show that septins (SEPT) are essential for CDT-induced protrusion formation. SEPT2, -6, -7, and -9 accumulate at predetermined protrusion sites and form collar-like structures at the base of protrusions. The septin inhibitor forchlorfenuron or knockdown of septins inhibits protrusion formation. At protrusion sites, septins colocalize with the GTPase Cdc42 (cell division control protein 42) and its effector Borg (binder of Rho GTPases), which act as up-stream regulators of septin polymerization. Precipitation and surface plasmon resonance studies revealed high-affinity binding of septins to the microtubule plus-end tracking protein EB1, thereby guiding incoming microtubules. The data suggest that CDT usurps conserved regulatory principles involved in microtubule-membrane interaction, depending on septins, Cdc42, Borgs, and restructuring of the actin cytoskeleton. PMID:27339141

  14. The Edges of Pancreatic Islet β Cells Constitute Adhesive and Signaling Microdomains

    Directory of Open Access Journals (Sweden)

    Erez Geron

    2015-01-01

    Full Text Available Pancreatic islet β cells are organized in rosette-like structures around blood vessels and exhibit an artery-to-vein orientation, but they do not display the typical epithelial polarity. It is unclear whether these cells present a functional asymmetry related to their spatial organization. Here, we identify murine β cell edges, the sites at which adjacent cell faces meet at a sharp angle, as surface microdomains of cell-cell adhesion and signaling. The edges are marked by enrichment of F-actin and E-cadherin and are aligned between neighboring cells. The edge organization is E-cadherin contact dependent and correlates with insulin secretion capacity. Edges display elevated levels of glucose transporters and SNAP25 and extend numerous F-actin-rich filopodia. A similar β cell edge organization was observed in human islets. When stimulated, β cell edges exhibit high calcium levels. In view of the functional importance of intra-islet communication, the spatial architecture of their edges may prove fundamental for coordinating physiological insulin secretion.

  15. Edge coating apparatus with movable roller applicator for solar cell substrates

    Science.gov (United States)

    Pavani, Luca; Abas, Emmanuel

    2012-12-04

    A non-contact edge coating apparatus includes an applicator for applying a coating material on an edge of a solar cell substrate and a control system configured to drive the applicator. The control system may drive the applicator along an axis to maintain a distance with an edge of the substrate as the substrate is rotated to have the edge coated with a coating material. The applicator may include a recessed portion into which the edge of the substrate is received for edge coating. For example, the applicator may be a roller with a groove. Coating material may be introduced into the groove for application onto the edge of the substrate. A variety of coating materials may be employed with the apparatus including hot melt ink and UV curable plating resist.

  16. Cell edges accumulate gamma tubulin complex components and nucleate microtubules following cytokinesis in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Chris Ambrose

    Full Text Available Microtubules emanate from distinct organizing centers in fungal and animal cells. In plant cells, by contrast, microtubules initiate from dispersed sites in the cell cortex, where they then self-organize into parallel arrays. Previous ultrastructural evidence suggested that cell edges participate in microtubule nucleation but so far there has been no direct evidence for this. Here we use live imaging to show that components of the gamma tubulin nucleation complex (GCP2 and GCP3 localize at distinct sites along the outer periclinal edge of newly formed crosswalls, and that microtubules grow predominantly away from these edges. These data confirm a role for cell edges in microtubule nucleation, and suggest that an asymmetric distribution of microtubule nucleation factors contributes to cortical microtubule organization in plants, in a manner more similar to other kingdoms than previously thought.

  17. Prominin-2 expression increases protrusions, decreases caveolae and inhibits Cdc42 dependent fluid phase endocytosis

    International Nuclear Information System (INIS)

    Highlights: •Prominin-2 expression induced protrusions that co-localized with lipid raft markers. •Prominin-2 expression decreased caveolae, caveolar endocytosis and increased pCav1. •Prominin-2 expression inhibited fluid phase endocytosis by inactivation of Cdc42. •These endocytic effects can be reversed by adding exogenous cholesterol. •Caveolin1 knockdown restored fluid phase endocytosis in Prominin2 expressing cells. -- Abstract: Background: Membrane protrusions play important roles in biological processes such as cell adhesion, wound healing, migration, and sensing of the external environment. Cell protrusions are a subtype of membrane microdomains composed of cholesterol and sphingolipids, and can be disrupted by cholesterol depletion. Prominins are pentaspan membrane proteins that bind cholesterol and localize to plasma membrane (PM) protrusions. Prominin-1 is of great interest as a marker for stem and cancer cells, while Prominin-2 (Prom2) is reportedly restricted to epithelial cells. Aim: To characterize the effects of Prom-2 expression on PM microdomain organization. Methods: Prom2-fluorescent protein was transfected in human skin fibroblasts (HSF) and Chinese hamster ovary (CHO) cells for PM raft and endocytic studies. Caveolae at PM were visualized using transmission electron microscopy. Cdc42 activation was measured and caveolin-1 knockdown was performed using siRNAs. Results: Prom2 expression in HSF and CHO cells caused extensive Prom2-positive protrusions that co-localized with lipid raft markers. Prom2 expression significantly decreased caveolae at the PM, reduced caveolar endocytosis and increased caveolin-1 phosphorylation. Prom2 expression also inhibited Cdc42-dependent fluid phase endocytosis via decreased Cdc42 activation. Effects on endocytosis were reversed by addition of cholesterol. Knockdown of caveolin-1 by siRNA restored Cdc42 dependent fluid phase endocytosis in Prom2-expressing cells. Conclusions: Prom2 protrusions primarily

  18. Prominin-2 expression increases protrusions, decreases caveolae and inhibits Cdc42 dependent fluid phase endocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Raman Deep, E-mail: Takhter.Ramandeep@mayo.edu; Schroeder, Andreas S.; Scheffer, Luana; Holicky, Eileen L.; Wheatley, Christine L.; Marks, David L., E-mail: Marks.david@mayo.edu; Pagano, Richard E.

    2013-05-10

    Highlights: •Prominin-2 expression induced protrusions that co-localized with lipid raft markers. •Prominin-2 expression decreased caveolae, caveolar endocytosis and increased pCav1. •Prominin-2 expression inhibited fluid phase endocytosis by inactivation of Cdc42. •These endocytic effects can be reversed by adding exogenous cholesterol. •Caveolin1 knockdown restored fluid phase endocytosis in Prominin2 expressing cells. -- Abstract: Background: Membrane protrusions play important roles in biological processes such as cell adhesion, wound healing, migration, and sensing of the external environment. Cell protrusions are a subtype of membrane microdomains composed of cholesterol and sphingolipids, and can be disrupted by cholesterol depletion. Prominins are pentaspan membrane proteins that bind cholesterol and localize to plasma membrane (PM) protrusions. Prominin-1 is of great interest as a marker for stem and cancer cells, while Prominin-2 (Prom2) is reportedly restricted to epithelial cells. Aim: To characterize the effects of Prom-2 expression on PM microdomain organization. Methods: Prom2-fluorescent protein was transfected in human skin fibroblasts (HSF) and Chinese hamster ovary (CHO) cells for PM raft and endocytic studies. Caveolae at PM were visualized using transmission electron microscopy. Cdc42 activation was measured and caveolin-1 knockdown was performed using siRNAs. Results: Prom2 expression in HSF and CHO cells caused extensive Prom2-positive protrusions that co-localized with lipid raft markers. Prom2 expression significantly decreased caveolae at the PM, reduced caveolar endocytosis and increased caveolin-1 phosphorylation. Prom2 expression also inhibited Cdc42-dependent fluid phase endocytosis via decreased Cdc42 activation. Effects on endocytosis were reversed by addition of cholesterol. Knockdown of caveolin-1 by siRNA restored Cdc42 dependent fluid phase endocytosis in Prom2-expressing cells. Conclusions: Prom2 protrusions primarily

  19. Calponin 2 Acts As an Effector of Noncanonical Wnt-Mediated Cell Polarization during Neural Crest Cell Migration

    OpenAIRE

    Bärbel Ulmer; Cathrin Hagenlocher; Silke Schmalholz; Sabrina Kurz; Axel Schweickert; Ayelet Kohl; Lee Roth; Dalit Sela-Donenfeld; Martin Blum

    2013-01-01

    Neural crest cells (NCCs) migrate throughout the embryo to differentiate into cell types of all germ layers. Initial directed NCC emigration relies on planar cell polarity (PCP), which through the activity of the small GTPases RhoA and Rac governs the actin-driven formation of polarized cell protrusions. We found that the actin binding protein calponin 2 (Cnn2) was expressed in protrusions at the leading edge of migratory NCCs in chicks and frogs. Cnn2 knockdown resulted in NCC migration defe...

  20. Cellular blebs: pressure-driven, axisymmetric, membrane protrusions

    KAUST Repository

    Woolley, Thomas E.

    2013-07-16

    Blebs are cellular protrusions that are used by cells for multiple purposes including locomotion. A mechanical model for the problem of pressure-driven blebs based on force and moment balances of an axisymmetric shell model is proposed. The formation of a bleb is initiated by weakening the shell over a small region, and the deformation of the cellular membrane from the cortex is obtained during inflation. However, simply weakening the shell leads to an area increase of more than 4 %, which is physically unrealistic. Thus, the model is extended to include a reconfiguration process that allows large blebs to form with small increases in area. It is observed that both geometric and biomechanical constraints are important in this process. In particular, it is shown that although blebs are driven by a pressure difference across the cellular membrane, it is not the limiting factor in determining bleb size. © 2013 Springer-Verlag Berlin Heidelberg.

  1. Fluxes of water through aquaporin 9 weaken membrane-cytoskeleton anchorage and promote formation of membrane protrusions.

    Directory of Open Access Journals (Sweden)

    Thommie Karlsson

    Full Text Available All modes of cell migration require rapid rearrangements of cell shape, allowing the cell to navigate within narrow spaces in an extracellular matrix. Thus, a highly flexible membrane and a dynamic cytoskeleton are crucial for rapid cell migration. Cytoskeleton dynamics and tension also play instrumental roles in the formation of different specialized cell membrane protrusions, viz. lamellipodia, filopodia, and membrane blebs. The flux of water through membrane-anchored water channels, known as aquaporins (AQPs has recently been implicated in the regulation of cell motility, and here we provide novel evidence for the role of AQP9 in the development of various forms of membrane protrusion. Using multiple imaging techniques and cellular models we show that: (i AQP9 induced and accumulated in filopodia, (ii AQP9-associated filopodial extensions preceded actin polymerization, which was in turn crucial for their stability and dynamics, and (iii minute, local reductions in osmolarity immediately initiated small dynamic bleb-like protrusions, the size of which correlated with the reduction in osmotic pressure. Based on this, we present a model for AQP9-induced membrane protrusion, where the interplay of water fluxes through AQP9 and actin dynamics regulate the cellular protrusive and motile activity of cells.

  2. Infantile Perineal Protrusion in Two Monochorionic Twins

    Directory of Open Access Journals (Sweden)

    Paola Cavicchioli

    2014-11-01

    Full Text Available Case Report - Two female monochorionic-monoamniotic twins showed the same kind of infantile perineal protrusion (IPP at birth. Lesions in both twins progressively healed until resolution in 6 weeks' time; none of the twins have manifested, till date, alvus disturbances. Discussion and Literature Review - A literature review numbers approximately 100 reports of IPP. This condition has been classically classified into three categories: congenital/familiar (i.e., female sex, positive parental history of IPP, acquired (mainly due to constipation, and associated with lichen sclerosus et atrophicus. Conclusions and Final Remarks - This case report describes, for the first time, the presence of IPP in monochorionic-monoamniotic twins, supporting the existence of hereditary/genetic factors in the developing of this condition.

  3. Dkk-1 Inhibits Intestinal Epithelial Cell Migration by Attenuating Directional Polarization of Leading Edge Cells

    Science.gov (United States)

    Koch, Stefan; Capaldo, Christopher T.; Samarin, Stanislav; Nava, Porfirio; Neumaier, Irmgard; Skerra, Arne; Sacks, David B.; Parkos, Charles A.

    2009-01-01

    Wnt signaling pathways regulate proliferation, motility, and survival in a variety of human cell types. Dickkopf-1 (Dkk-1) is a secreted Wnt antagonist that has been proposed to regulate tissue homeostasis in the intestine. In this report, we show that Dkk-1 is secreted by intestinal epithelial cells after wounding and that it inhibits cell migration by attenuating the directional orientation of migrating epithelial cells. Dkk-1 exposure induced mislocalized activation of Cdc42 in migrating cells, which coincided with a displacement of the polarity protein Par6 from the leading edge. Consequently, the relocation of the microtubule organizing center and the Golgi apparatus in the direction of migration was significantly and persistently inhibited in the presence of Dkk-1. Small interfering RNA-induced down-regulation of Dkk-1 confirmed that extracellular exposure to Dkk-1 was required for this effect. Together, these data demonstrate a novel role of Dkk-1 in the regulation of directional polarization of migrating intestinal epithelial cells, which contributes to the effect of Dkk-1 on wound closure in vivo. PMID:19776352

  4. Edges of human embryonic stem cell colonies display distinct mechanical properties and differentiation potential

    OpenAIRE

    Rosowski, Kathryn A.; Mertz, Aaron F.; Samuel Norcross; Dufresne, Eric R.; Valerie Horsley

    2015-01-01

    In order to understand the mechanisms that guide cell fate decisions during early human development, we closely examined the differentiation process in adherent colonies of human embryonic stem cells (hESCs). Live imaging of the differentiation process reveals that cells on the outer edge of the undifferentiated colony begin to differentiate first and remain on the perimeter of the colony to eventually form a band of differentiation. Strikingly, this band is of constant width in all colonies,...

  5. A critical stress model for cell motility

    OpenAIRE

    Mehrayin Mehrnush; Farmanzad Farhad; Mozafari Masoud; Vashaee Daryoosh; Tayebi Lobat

    2012-01-01

    Abstract A detailed theoretical model that combines the conventional viscoelastic continuum description of cell motion with a dynamic active stress is presented. The model describes the ameboid cells movement comprising of protrusion and adhesion of the front edge followed by detachment and movement of the tail. Unlike the previous viscoelastic descriptions in which the cell movement is steady, the presented model describes the “walking” of the cell in response to specific active stress compo...

  6. Spectral and energy efficiency analysis of uplink heterogeneous networks with small-cells on edge

    KAUST Repository

    Shakir, Muhammad Zeeshan

    2014-12-01

    This paper presents a tractable mathematical framework to analyze the spectral and energy efficiency of an operator initiated deployment of the small-cells (e.g., femtocells) where the small-cell base stations are deliberately positioned around the edge of the macrocell. The considered deployment facilitates the cell-edge mobile users in terms of their coverage, spectral, and energy efficiency and is referred to as cell-on-edge (COE) configuration. The reduction in energy consumption is achieved by considering fast power control where the mobile users transmit with adaptive power to compensate the path loss, shadowing and fading. In particular, we develop a moment generating function (MGF) based approach to derive analytical bounds on the area spectral efficiency and exact expressions for the energy efficiency of the mobile users in the considered COE configuration over generalized-K fading channels. Besides the COE configuration, the derived bounds are also shown to be useful in evaluating the performance of random small-cell deployments, e.g., uniformly distributed small-cells. Simulation results are presented to demonstrate the improvements in spectral and energy efficiency of the COE configuration with respect to macro-only networks and other unplanned deployment strategies. © 2014 Elsevier B.V. All rights reserved.

  7. Edge sealing for low cost stability enhancement of roll-to-roll processed flexible polymer solar cell modules

    DEFF Research Database (Denmark)

    Tanenbaum, David M.; Dam, Henrik Friis; Rösch, R.;

    2012-01-01

    Fully roll-to-roll processed polymer solar cell modules were prepared, characterized, and laminated. Cell modules were cut from the roll and matched pairs were selected, one module with exposed cut edges, the other laminated again with the same materials and adhesive sealing fully around the cut...... edges. The edge sealing rim was 10 mm wide. Cell modules were characterized by periodic measurements of IV curves over extended periods in a variety of conditions, as well as by a variety of spatial imaging techniques. Data show significant stability benefits of the edge sealing process. The results...... of the imaging experiments show that the ingress of atmospheric reactants from the edges leads to degradation. In the case of edge sealed devices the same effects are observed but significantly slowed down. In particular, the fast nonlinear degradation is eliminated....

  8. Many-faced cells and many-edged faces in 3D Poisson–Voronoi tessellations

    International Nuclear Information System (INIS)

    Motivated by recent new Monte Carlo data we investigate a heuristic asymptotic theory that applies to n-faced 3D Poisson–Voronoi cells in the limit of large n. We show how this theory may be extended to n-edged cell faces. It predicts the leading order large-n behavior of the average volume and surface area of the n-faced cell, and of the average area and perimeter of the n-edged face. Such a face is shown to be surrounded by a toroidal region of volume n/λ (with λ the seed density) that is void of seeds. Two neighboring cells sharing an n-edged face are found to have their seeds at a typical distance that scales as n−1/6 and whose probability law we determine. We present a new data set of 4 × 109 Monte Carlo generated 3D Poisson–Voronoi cells, larger than any before. Full compatibility is found between the Monte Carlo data and the theory. Deviations from the asymptotic predictions are explained in terms of subleading corrections whose powers in n we estimate from the data. (paper)

  9. Many-faced cells and many-edged faces in 3D Poisson-Voronoi tessellations

    Science.gov (United States)

    Hilhorst, H. J.; Lazar, E. A.

    2014-10-01

    Motivated by recent new Monte Carlo data we investigate a heuristic asymptotic theory that applies to n-faced 3D Poisson-Voronoi cells in the limit of large n. We show how this theory may be extended to n-edged cell faces. It predicts the leading order large-n behavior of the average volume and surface area of the n-faced cell, and of the average area and perimeter of the n-edged face. Such a face is shown to be surrounded by a toroidal region of volume n/λ (with λ the seed density) that is void of seeds. Two neighboring cells sharing an n-edged face are found to have their seeds at a typical distance that scales as n-1/6 and whose probability law we determine. We present a new data set of 4 × 109 Monte Carlo generated 3D Poisson-Voronoi cells, larger than any before. Full compatibility is found between the Monte Carlo data and the theory. Deviations from the asymptotic predictions are explained in terms of subleading corrections whose powers in n we estimate from the data.

  10. A protrusion can "eclipse" looping of a long self-avoiding chain

    CERN Document Server

    Pollak, Yaroslav; Amit, Roee

    2016-01-01

    We simulate long self-avoiding chains using a weighted-biased sampling Monte-Carlo algorithm, and compute the probabilities for chain looping with and without a protrusion. We find that a protrusion near one of the chain's termini reduces the probability of looping, even for chains much longer than the protrusion-chain-terminus distance. This effect increases with protrusion size, and decreases with protrusion-terminus distance. We model the simulated results theoretically by considering how the protrusion "eclipses" the chain terminus closer to the protrusion from the more distant chain terminus. This eclipse mechanism has implications for understanding the regulatory role of proteins bound to DNA.

  11. CT evaluation of medial protrusion of the lamina papyracea

    International Nuclear Information System (INIS)

    The frequency, location and gender difference of the medial protrusion of the lamina papyracea toward the ethmoid sinus were evaluated in 522 patients who underwent CT of the paranasal sinus region at our institution between January 1999 and January 2002. The area of interest was the nose and paranasal sinuses in 295 patients, auditory organ in 190 patients and maxillofacial area in 37 patients. The lamina papyracea was clearly identified in all the patients. Patients with a past history of paranasal sinus surgery and those with injuries in the lamina papyracea were excluded from the study. The patients consisted of 283 males and 239 females aged between 6 and 94 years. Twenty-nine patients were younger than 20 years old. Axial slices were taken in most cases. Medial protrusion was judged to be positive in cases where the lamina papyracea evidently deviated toward the ethmoid sinus on CT and the CT value of the protruded area was identical to that of the orbital fat. Medial protrusion of the lamina papyracea was positive in 4 males and 2 females with a frequency of 1.15%. All the 6 patients were older than 20 years old. The protrusion was located in the anterior ethmoid in 2 patients, middle ethmoid in 3 patients and entire ethmoid area in 1 patient whose ethmoid sinuses were poorly developed. The protrusion was also located on the right side in 4 patients and on the left side in 2. Bilateral protrusion was not observed. It has been reported that the frequency of medial protrusion of the lamina papyracea is about 1%. CT is an essential examination before surgery of the nose and paranasal sinuses. It is important to preoperatively evaluate the anatomical relation of critical structures including the lamina papyracea. (author)

  12. Iron speciation in human cancer cells by K-edge total reflection X-ray fluorescence-X-ray absorption near edge structure analysis

    Science.gov (United States)

    Polgári, Zs.; Meirer, F.; Sasamori, S.; Ingerle, D.; Pepponi, G.; Streli, C.; Rickers, K.; Réti, A.; Budai, B.; Szoboszlai, N.; Záray, G.

    2011-03-01

    X-ray absorption near edge structure (XANES) analysis in combination with synchrotron radiation induced total reflection X-ray fluorescence (SR-TXRF) acquisition was used to determine the oxidation state of Fe in human cancer cells and simultaneously their elemental composition by applying a simple sample preparation procedure consisting of pipetting the cell suspension onto the quartz reflectors. XANES spectra of several inorganic and organic iron compounds were recorded and compared to that of different cell lines. The XANES spectra of cells, independently from the phase of cell growth and cell type were very similar to that of ferritin, the main Fe store within the cell. The spectra obtained after CoCl 2 or NiCl 2 treatment, which could mimic a hypoxic state of cells, did not differ noticeably from that of the ferritin standard. After 5-fluorouracil administration, which could also induce an oxidative-stress in cells, the absorption edge position was shifted toward higher energies representing a higher oxidation state of Fe. Intense treatment with antimycin A, which inhibits electron transfer in the respiratory chain, resulted in minor changes in the spectrum, resembling rather the N-donor Fe-α,α'-dipyridyl complex at the oxidation energy of Fe(III), than ferritin. The incorporation of Co and Ni in the cells was followed by SR-TXRF measurements.

  13. Iron speciation in human cancer cells by K-edge total reflection X-ray fluorescence-X-ray absorption near edge structure analysis

    International Nuclear Information System (INIS)

    X-ray absorption near edge structure (XANES) analysis in combination with synchrotron radiation induced total reflection X-ray fluorescence (SR-TXRF) acquisition was used to determine the oxidation state of Fe in human cancer cells and simultaneously their elemental composition by applying a simple sample preparation procedure consisting of pipetting the cell suspension onto the quartz reflectors. XANES spectra of several inorganic and organic iron compounds were recorded and compared to that of different cell lines. The XANES spectra of cells, independently from the phase of cell growth and cell type were very similar to that of ferritin, the main Fe store within the cell. The spectra obtained after CoCl2 or NiCl2 treatment, which could mimic a hypoxic state of cells, did not differ noticeably from that of the ferritin standard. After 5-fluorouracil administration, which could also induce an oxidative-stress in cells, the absorption edge position was shifted toward higher energies representing a higher oxidation state of Fe. Intense treatment with antimycin A, which inhibits electron transfer in the respiratory chain, resulted in minor changes in the spectrum, resembling rather the N-donor Fe-α,α'-dipyridyl complex at the oxidation energy of Fe(III), than ferritin. The incorporation of Co and Ni in the cells was followed by SR-TXRF measurements.

  14. Alignment of muscle precursor cells on the vertical edges of thick carbon nanotube films

    Energy Technology Data Exchange (ETDEWEB)

    Holt, Ian, E-mail: ian.holt@rjah.nhs.uk [Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, Shropshire SY10 7AG (United Kingdom); Institute for Science and Technology in Medicine, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom); Gestmann, Ingo, E-mail: Ingo.Gestmann@fei.com [FEI Europe B.V., Achtseweg Noord 5, 5651 Eindhoven (Netherlands); Wright, Andrew C., E-mail: a.wright@glyndwr.ac.uk [Advanced Materials Research Laboratory, Glyndwr University, Plas Coch, Mold Rd, Wrexham LL11 2AW (United Kingdom)

    2013-10-15

    The development of scaffolds and templates is an essential aspect of tissue engineering. We show that thick (> 0.5 mm) vertically aligned carbon nanotube films, made by chemical vapour deposition, can be used as biocompatible substrates for the directional alignment of mouse muscle cells where the cells grow on the exposed sides of the films. Ultra high resolution scanning electron microscopy reveals that the films themselves consist mostly of small diameter (10 nm) multi-wall carbon nanotubes of wavy morphology with some single wall carbon nanotubes. Our findings show that for this alignment to occur the nanotubes must be in pristine condition. Mechanical wiping of the films to create directional alignment is detrimental to directional bioactivity. Larger areas for study have been formed from a composite of multiply stacked narrow strips of nanotubes wipe-transferred onto elastomer supports. These composite substrates appear to show a useful degree of alignment of the cells. Highlights: • Highly oriented muscle precursor cells grown on edges of carbon nanotube pads • Mechanical treatment of nanotube pads highly deleterious to cell growth on edges • Larger areas created from wipe-transfer of narrow strips of nanotubes onto elastomer supports • Very high resolution SEM reveals clues to aligned cell growth.

  15. Alignment of muscle precursor cells on the vertical edges of thick carbon nanotube films

    International Nuclear Information System (INIS)

    The development of scaffolds and templates is an essential aspect of tissue engineering. We show that thick (> 0.5 mm) vertically aligned carbon nanotube films, made by chemical vapour deposition, can be used as biocompatible substrates for the directional alignment of mouse muscle cells where the cells grow on the exposed sides of the films. Ultra high resolution scanning electron microscopy reveals that the films themselves consist mostly of small diameter (10 nm) multi-wall carbon nanotubes of wavy morphology with some single wall carbon nanotubes. Our findings show that for this alignment to occur the nanotubes must be in pristine condition. Mechanical wiping of the films to create directional alignment is detrimental to directional bioactivity. Larger areas for study have been formed from a composite of multiply stacked narrow strips of nanotubes wipe-transferred onto elastomer supports. These composite substrates appear to show a useful degree of alignment of the cells. Highlights: • Highly oriented muscle precursor cells grown on edges of carbon nanotube pads • Mechanical treatment of nanotube pads highly deleterious to cell growth on edges • Larger areas created from wipe-transfer of narrow strips of nanotubes onto elastomer supports • Very high resolution SEM reveals clues to aligned cell growth

  16. Traffic Jams and Shocks of Molecular Motors inside Cellular Protrusions

    CERN Document Server

    Pinkoviezky, Itai

    2013-01-01

    Molecular motors are involved in key transport processes inside actin-based cellular protrusions. The motors carry cargo proteins to the protrusion tip which participate in regulating the actin polymerization, and play a key role in facilitating the growth and formation of such protrusions. It is observed that the motors accumulate at the tips of cellular protrusions, and in addition form aggregates that are found to drift towards the protrusion base at the rate of actin treadmilling. We present a one-dimensional driven lattice model, where motors become inactive after delivering their cargo at the tip, or by loosing their cargo to a cargo-less neighbor. The results suggest that the experimental observations may be explained by the formation of traffic jams that form at the tip. The model is solved using a novel application of mean-field and shock analysis. We find a new class of shocks that undergo intermittent collapses, and on average do not obey the Rankine-Hugoniot relation.

  17. Edge-Modified Phosphorene Nanoflake Heterojunctions as Highly Efficient Solar Cells.

    Science.gov (United States)

    Hu, Wei; Lin, Lin; Yang, Chao; Dai, Jun; Yang, Jinlong

    2016-03-01

    We propose to use edge-modified phosphorene nanoflakes (PNFs) as donor and acceptor materials for heterojunction solar cells. By using density functional theory based calculations, we show that heterojunctions consisting of hydrogen- and fluorine-passivated PNFs have a number of desired optoelectronic properties that are suitable for use in a solar cell. We explain why these properties hold for these types of heterojunctions. Our calculations also predict that the maximum energy conversion efficiency of these type of heterojunctions, which can be easily fabricated, can be as high as 20%, making them extremely competitive with other types of two-dimensional heterojunctions. PMID:26848505

  18. Regulation of Localized Rac Activation in Leading Edge of Directed Migrating Cells%定向迁移细胞前沿Rac局部化激活的分子调控

    Institute of Scientific and Technical Information of China (English)

    李友军; 罗孝勇; 郭向荣

    2013-01-01

    Rac activation is strongly regulated spacially and temporally in migrating cells, leading to the formation of specific cell protrusion-lamellipodia in leading edge of the cells and generating the pushing force to put the cells forward, but the molecular mechanism of positive regulation of localized Rac activation remains unclear. We propose that the phosphorylation of the intracellular α4 integrin inhibits the interaction of α4 with paxillin, thus the signaling pathway paxillin-GITl -PIX-PAK would be formed, leading to localized Rac activation in leading edge of the migrating cells. In the paper, western blotting clearly showed that the interactions accurately exist between the cytoskeleton proteins GIT1 and paxillin or PIX respectively. Fluorescent colocalization confirmed that the interactions between GIT1 and paxillin or PIX occur in the leading edge of the cells. Rac activation assay elucidated that Rac is in activated state (GTP-bound) under the stimulation of ECM fibronectin, suggesting that the signaling pathway paxillin-GITl -PIX-PAK led to Rac activation. The results built the experimental basis for the study of regulation mechanism on localized Rac activation in leading edge of directed migrating cells.%提出构想:当α4胞内区域磷酸化而抑制其与paxillin结合时,paxillin、GIT1与PIX、PAK形成信号分子复合物.由于PIX为Rac的转换分子,PAK为Rac的效应分子,构成了paxillin-GIT1-PIX-PAK信号转导通路,从而促使Rac在细胞前沿持续地局部化激活,导致片状足的形成,产生细胞向前扩展推动力.研究结果表明,GIT1与paxillin、PIX在活细胞中均存在强烈的相互作用,且这种相互作用可发生在细胞前沿.由于Rac的转换因子PIX(PAK-interacting exchange factor)在活细胞中往往与PAK相伴而行,因而,在细胞前沿,必定存在paxillin-GIT1-PIX-PAK的信号转导通路.在纤粘蛋白(fibronectin)刺激下,整合素α4诱导Rac蛋白处于激活状态(GTP-bound).

  19. Biomechanics of epithelial cell islands analyzed by modeling and experimentation

    CERN Document Server

    Coburn, Luke; Noppe, Adrian; Caldwell, Benjamin J; Moussa, Elliott; Yap, Chloe; Priya, Rashmi; Lobaskin, Vladimir; Roberts, Anthony P; Yap, Alpha S; Neufeld, Zoltan; Gomez, Guillermo A

    2016-01-01

    We generated a new computational approach to analyze the biomechanics of epithelial cell islands that combines both vertex and contact-inhibition-of-locomotion models to include both cell-cell and cell-substrate adhesion. Examination of the distribution of cell protrusions (adhesion to the substrate) in the model predicted high order profiles of cell organization that agree with those previously seen experimentally. Cells acquired an asymmetric distribution of protrusions (and traction forces) that decreased when moving from the edge to the island center. Our in silico analysis also showed that tension on cell-cell junctions (and monolayer stress) is not homogeneous across the island. Instead it is higher at the island center and scales up with island size, which we confirmed experimentally using laser ablation assays and immunofluorescence. Moreover, our approach has the minimal elements necessary to reproduce mechanical crosstalk between both cell-cell and cell substrate adhesion systems. We found that an i...

  20. Edge sealing for low cost stability enhancement of roll-to-roll processed flexible polymer solar cell modules

    DEFF Research Database (Denmark)

    Tanenbaum, David M.; Dam, Henrik Friis; Rösch, R.; Jørgensen, Mikkel; Hoppe, Harald; Krebs, Frederik C

    2012-01-01

    Fully roll-to-roll processed polymer solar cell modules were prepared, characterized, and laminated. Cell modules were cut from the roll and matched pairs were selected, one module with exposed cut edges, the other laminated again with the same materials and adhesive sealing fully around the cut ...... the imaging experiments show that the ingress of atmospheric reactants from the edges leads to degradation. In the case of edge sealed devices the same effects are observed but significantly slowed down. In particular, the fast nonlinear degradation is eliminated.......Fully roll-to-roll processed polymer solar cell modules were prepared, characterized, and laminated. Cell modules were cut from the roll and matched pairs were selected, one module with exposed cut edges, the other laminated again with the same materials and adhesive sealing fully around the cut...... edges. The edge sealing rim was 10 mm wide. Cell modules were characterized by periodic measurements of IV curves over extended periods in a variety of conditions, as well as by a variety of spatial imaging techniques. Data show significant stability benefits of the edge sealing process. The results of...

  1. Electron transport in edge-disordered graphene nanoribbons

    DEFF Research Database (Denmark)

    Saloriutta, Karri; Hancock, Y.; Karkkainen, Asta;

    2011-01-01

    Ab initio methods are used to study the spin-resolved transport properties of graphene nanoribbons (GNRs) that have both chemical and structural edge disorder. Oxygen edge adsorbates on ideal and protruded ribbons are chosen as representative examples, with the protrusions forming the smallest...

  2. CFD simulations to study the effects of wall protrusions on microfluidic mixing

    International Nuclear Information System (INIS)

    In this study the effects of different types of wall protrusions on microfluidic mixing are studied using computational fluid dynamics (CFD) simulations. Two new protrusions, single first bracket protrusions and double opposite first bracket protrusions (DOFBPs), are conceptualized, evaluated through CFD simulations and compared to protrusions having standard geometrical shapes, e.g. rectangular protrusions, triangular protrusions and semicircular protrusions. In the range of Reynolds numbers covered in this study, the microchannel having an opposed T-junction and DOFBPs is found to provide good mixing. A hybrid approach relying on the modification of microfluidic junctions as well as wall protrusions for enhancing microfluidic mixing is also evaluated. The microchannel based on the hybrid approach of an OA 10°–20°–165° WY-junction and DOFBPs is also found to provide very good mixing for a wide range of Reynolds numbers. (paper)

  3. CFD simulations to study the effects of wall protrusions on microfluidic mixing

    Science.gov (United States)

    Sarkar, Sourav; Singh, K. K.; Shankar, V.; Shenoy, K. T.

    2015-08-01

    In this study the effects of different types of wall protrusions on microfluidic mixing are studied using computational fluid dynamics (CFD) simulations. Two new protrusions, single first bracket protrusions and double opposite first bracket protrusions (DOFBPs), are conceptualized, evaluated through CFD simulations and compared to protrusions having standard geometrical shapes, e.g. rectangular protrusions, triangular protrusions and semicircular protrusions. In the range of Reynolds numbers covered in this study, the microchannel having an opposed T-junction and DOFBPs is found to provide good mixing. A hybrid approach relying on the modification of microfluidic junctions as well as wall protrusions for enhancing microfluidic mixing is also evaluated. The microchannel based on the hybrid approach of an OA 10°-20°-165° WY-junction and DOFBPs is also found to provide very good mixing for a wide range of Reynolds numbers.

  4. Collision probabilities for plate geometry cells with an approximate treatment of plate edge regions

    International Nuclear Information System (INIS)

    A method of allowing for plate edge effects in the calculation of the neutron flux in the plate geometry cells of zero power fast critical assemblies is developed and evaluated. Each layer contains a central region and an edge region and an approximate method for calculating the collision probabilities relating regions in different layers is developed. Collision probabilities are first calculated for a number of directions, i (having direction cosines, μi, relative to the normal to the plates). These are then combined with Gaussian weights, wi. Escape, collision and transmission probabilities for each layer are calculated assuming that the neutrons travel only in one type of material within the layer. These material types are the central region material, the edge region material and a mixture of the two (which depends on the material fractions within the layer and the angle, i). The fraction of the neutrons travelling in each material type depends on the angle and the layer material fractions. The method is compared with Monte Carlo calculations made for single energy groups, and is used to calculate a number of zero leakage plate geometry test zones for which measurements have been made in the ZEBRA facility. (author)

  5. Iron speciation in human cancer cells by K-Edge TXRF-XANES

    International Nuclear Information System (INIS)

    Complete text of publication follows. X-Ray Absorption Near Edge Structure (XANES) analysis in combination with Synchrotron Radiation induced Total reflection X-Ray Fluorescence (SR-TXRF) acquisition was used to determine the oxidation state of Fe in human cancer cells. The first measurements reported here were intended as a feasibility study which should i) show if the setup is sensitive enough to perform XANES measurements on the colon cancer cell samples and ii) lead to a new and proper sample preparation method which will ensure the stability of the oxidation state of Fe during sampling, sample treatment, storage, transport and analysis. As total reflection geometry offers very high sensitivities for elemental determination in X-ray fluorescence analysis these characteristics can be used to apply this set up for the speciation of minute amounts of metals in X-ray absorption experiments in the fluorescence mode. The advantage of the investigation using SR-TXRF-XANES is that the sample preparation can be reduced to a minimum: the cells available in a suspension can be directly pipetted in the Si reflectors, dried, inserted in the vacuum chamber and measured. The Fe K-Edge XANES measurements in fluorescence mode and grazing incidence geometry were carried out using the TXRF vacuum chamber setup at the beamline L at the Hamburger Synchrotronstrahlungslabor (HASYLAB) at DESY. Human colon cancer cell line HT-29 as well as human breast cancer cell line ZR-75-1 and human fibrosarcoma cell line HT-1080 in different phases of the cell growth were prepared at the Department of Clinical Research, National Institute of Oncology, Budapest, Hungary. When the cell growth was in log phase (exponential growth) the cells were treated with either CoCl2, NiCl2 or metamizole sodium. The aim was to gain information about the influence of these treatments on the cells relating to the Fe species. For comparison samples have also been taken during other characteristic phases of cell

  6. Theory of a Scanning Tunneling Microscope with a Two-Protrusion Tip

    OpenAIRE

    Flatte, Michael E.; Byers, Jeff M.

    1995-01-01

    We consider a scanning tunneling microscope (STM) such that tunneling occurs through two atomically sharp protrusions on its tip. When the two protrusions are separated by at least several atomic spacings, the differential conductance of this STM depends on the electronic transport in the sample between the protrusions. Furthermore two-protrusion tips commonly occur during STM tip preparation. We explore possible applications to probing dynamical impurity potentials on a metallic surface and ...

  7. Band edge engineering of composite photoanodes for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Graphical Abstract: Display Omitted -- Abstract: As dye-sensitized solar cells (DSSCs) transition from iodide/triiodide-based electrolytes to organometallic complex redox couples with higher rates of recombination with electrons in the semiconductor, there is a need for semiconductor nanostructures that can rapidly transport electrons out of the device while maintaining high surface areas for the semiconductor/dye/electrolyte interface. A previously reported composite, with TiO2 nanoparticles coating ZnO nanorods, met these criteria but suffered from a barrier to electron transfer from the TiO2 to the ZnO. Here, the band edge positions of the TiO2 and ZnO have been shifted by doping with Zr4+ and Co2+, respectively, to arrive at the desired energetic alignment. The materials were characterized using diffuse-reflectance spectroscopy and a three-electrode measurement of the open circuit photovoltage under bandgap excitation (OCV). The OCV measurement indicated that the doping moved the conduction band minimum of ZnO to a more positive potential than that of the TiO2, enabling electron transfer from dye-sensitized TiO2 nanoparticles to the underlying ZnO nanorods for efficient charge collection. However, DSSC devices fabricated with the composite nanostructures did not show improved performance. This paper details a methodology for producing and measuring band-edge shifts along with the benefits and limitations thereof

  8. Edge restenosis: impact of low dose irradiation on cell proliferation and ICAM-1 expression

    Directory of Open Access Journals (Sweden)

    Hannekum Andreas

    2006-07-01

    Full Text Available Abstract Background Low dose irradiation (LDI of uninjured segments is the consequence of the suggestion of many authors to extend the irradiation area in vascular brachytherapy to minimize the edge effect. Atherosclerosis is a general disease and the uninjured segment close to the intervention area is often atherosclerotic as well, consisting of neointimal smooth muscle cells (SMC and quiescent monocytes (MC. The current study imitates this complex situation in vitro and investigates the effect of LDI on proliferation of SMC and expression of intercellular adhesion molecule-1 (ICAM-1 in MC. Methods Plaque tissue from advanced primary stenosing lesions of human coronary arteries (9 patients, age: 61 ± 7 years was extracted by local or extensive thrombendarterectomy. SMC were isolated and identified by positive reaction with smooth muscle α-actin. MC were isolated from buffy coat leukocytes using the MACS cell isolation kit. For identification of MC flow-cytometry analysis of FITC-conjugated CD68 and CD14 (FACScan was applied. SMC and MC were irradiated using megavoltage photon irradiation (CLINAC2300 C/D, VARIAN, USA of 6 mV at a focus-surface distance of 100 cm and a dose rate of 6 Gy min-1 with single doses of 1 Gy, 4 Gy, and 10 Gy. The effect on proliferation of SMC was analysed at day 10, 15, and 20. Secondly, total RNA of MC was isolated 1 h, 2 h, 3 h, and 4 h after irradiation and 5 μg of RNA was used in standard Northern blot analysis with ICAM-1 cDNA-probes. Results Both inhibitory and stimulatory effects were detected after irradiation of SMC with a dose of 1 Gy. At day 10 and 15 a significant antiproliferative effect was found; at day 20 after irradiation cell proliferation was significantly stimulated. Irradiation with 4 Gy and 10 Gy caused dose dependent inhibitory effects at day 10, 15, and 20. Expression of ICAM-1 in human MC was neihter inhibited nor stimulated by LDI. Conclusion Thus, the stimulatory effect of LDI on SMC

  9. Dkk-1 Inhibits Intestinal Epithelial Cell Migration by Attenuating Directional Polarization of Leading Edge Cells

    OpenAIRE

    Koch, Stefan; Capaldo, Christopher T.; Samarin, Stanislav; Nava, Porfirio; Neumaier, Irmgard; Skerra, Arne; Sacks, David B; Parkos, Charles A.; Nusrat, Asma

    2009-01-01

    Wnt signaling pathways regulate proliferation, motility, and survival in a variety of human cell types. Dickkopf-1 (Dkk-1) is a secreted Wnt antagonist that has been proposed to regulate tissue homeostasis in the intestine. In this report, we show that Dkk-1 is secreted by intestinal epithelial cells after wounding and that it inhibits cell migration by attenuating the directional orientation of migrating epithelial cells. Dkk-1 exposure induced mislocalized activation of Cdc42 in migrating c...

  10. Two-way cooperative AF relaying in spectrum-sharing systems: Enhancing cell-edge performance

    KAUST Repository

    Xia, Minghua

    2012-09-01

    In this contribution, two-way cooperative amplify-and-forward (AF) relaying technique is integrated into spectrumsharing wireless systems to improve spectral efficiency of secondary users (SUs). In order to share the available spectrum resources originally dedicated to primary users (PUs), the transmit power of a SU is optimized with respect to the average tolerable interference power at primary receivers. By analyzing outage probability and achievable data rate at the base station and at a cell-edge SU, our results reveal that the uplink performance is dominated by the average tolerable interference power at primary receivers, while the downlink always behaves like conventional one-way AF relaying and its performance is dominated by the average signal-to-noise ratio (SNR). These important findings provide fresh perspectives for system designers to improve spectral efficiency of secondary users in next-generation broadband spectrum-sharing wireless systems. © 2012 IEEE.

  11. Stem cells, a two-edged sword: Risks and potentials of regenerative medicine

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The recent advancements in stem cell (SC) biology have led to the concept of regenerative medicine, which is based on the potential of SC for therapies aimed to facilitate the repair of degenerating or injured tissues. Nonetheless, prior to large scale clinical appli- cations, critical aspects need to be further addressed, including the long-term safety, tolerability, and efficacy of SC-based treatments. Most problematic among the risks of SC-based therapies, in addition to the pos- sible rejection or loss of function of the infused cells, is their potential neoplastic transformation. Indeed, SCs may be used to cure devastating diseases, but their specific properties of self-renewal and clonogenicity may render them prone to generate cancers. In this respect, 'Stemness' might be seen as a two-edged sword, its bright side being represented by normal SCs, its dark side by cancer SCs. A better understand- ing of SC biology will help fulfill the promise of regen- erative medicine aimed at curing human pathologies and fighting cancer from its roots.

  12. Molten carbonate fuel cells: A high temperature fuel cell on the edge to commercialization

    Science.gov (United States)

    Bischoff, Manfred

    The Molten Carbonate Fuel Cell (MCFC) technology has been developed in USA, Japan, Korea and Europe for many years. What has started about 30 years ago as an interesting laboratory object has now matured to a potential alternative to conventional power generation systems. Especially the combined heat and power (CHP) generation is an area, where MCFC power plants can be applied with great advantage, due to the high efficiencies which can be achieved. It was demonstrated by several manufacturers that in the sub-MW region MCFC power plants can reach electrical efficiencies of 47%. By making use of the heat generated by the system, total efficiencies of more than 80% can be achieved. The present paper will discuss some aspects of the development work going on with a focus on the role of the molten carbonate contained in the cells. An outlook will be given for the future prospects of this young technology in a changing energy market.

  13. ELECTROACUPUNCTURE TREATMENT OF 176 CASES OF LUMBAR INTERVERTEBRAL DISC PROTRUSION

    Institute of Scientific and Technical Information of China (English)

    LI Lanmin

    2002-01-01

    In the present paper, 176 cases of lumbar intervertebral disc protrusion are treated with electroacupuncture (EA) and topical heat irradiation. Local tender-point is used as the main acupoint, combined with Tunzhong, Tiaoyue, Weizhong (BL 40) and Yanglingquan (GB 34). The treatment is conducted once daily, with 15 sessions being a therapeutic course. Following treatment, of 176 cases, 46 (26. 1%) are cured, 90 (51. 1%) have prominent improvement, 35 (19.8%) have amelioration and 5 (2.8%) have no apparent changes, with a total effective rate of 97.0%.

  14. Treatment of Protrusion of Cervical Intervertebral Disc by Tuina

    Institute of Scientific and Technical Information of China (English)

    YE Jian-guo

    2004-01-01

    Twenty-five cases of protrusion of cervical intervertebral disc were treated by the manipulations of rolling, pressing, pushing with one-finger, traction, obliquely pulling, grasping of five channels, sweeping, etc. The result showed that 10 cases were cured, 14 cases got marked effectiveness and 1 case was improved.%采用滚、按、一指禅、拔伸、斜扳、拿五经、扫散法等手法,治疗颈椎间盘突出症患者25例,结果治愈10例,显效14例,好转1例.

  15. Treatment of Protrusion of the Lumbar Intervertebral Disc by Massotherapy

    Institute of Scientific and Technical Information of China (English)

    程斌

    2001-01-01

    @@Clinically, there is a higher incidence of protrusion of the lumbar intervertebral disc. It can cause a terrible pain. The author has treated 66 cases by massotherapy, who were confirmatively diagnosed as having protrusion of the lumbar intervertebral disc by X-ray film and computer-aided tomography, with satisfactory results as reported in the following. Clinical Data Among the 66 cases in this series, 49 were male and 17 female, ranging in age from 26 to 59 years, averaging 36.2 years. All the patients had got lumbago and unilateral ischialgia, with the left side affected in 37 cases and the right side in 29 cases. The leg pain radiating to lateral malleolus was found in 28 cases, to dorsum of the foot in 24 cases, and to the toes in 14 cases. Intermittent claudication was present in 22 cases, numbness of the affected foot in 16 cases, pain exacerbated when coughing in 35 cases, scoliosis in 21 cases, and positive Lasegue's sign in 48 cases.

  16. Rewiring neuronal microcircuits of the brain via spine head protrusions--a role for synaptopodin and intracellular calcium stores.

    Science.gov (United States)

    Verbich, David; Becker, Denise; Vlachos, Andreas; Mundel, Peter; Deller, Thomas; McKinney, R Anne

    2016-01-01

    Neurological diseases associated with neuronal death are also accompanied by axonal denervation of connected brain regions. In these areas, denervation leads to a decrease in afferent drive, which may in turn trigger active central nervous system (CNS) circuitry rearrangement. This rewiring process is important therapeutically, since it can partially recover functions and can be further enhanced using modern rehabilitation strategies. Nevertheless, the cellular mechanisms of brain rewiring are not fully understood. We recently reported a mechanism by which neurons remodel their local connectivity under conditions of network-perturbance: hippocampal pyramidal cells can extend spine head protrusions (SHPs), which reach out toward neighboring terminals and form new synapses. Since this form of activity-dependent rewiring is observed only on some spines, we investigated the required conditions. We speculated, that the actin-associated protein synaptopodin, which is involved in several synaptic plasticity mechanisms, could play a role in the formation and/or stabilization of SHPs. Using hippocampal slice cultures, we found that ~70 % of spines with protrusions in CA1 pyramidal neurons contained synaptopodin. Analysis of synaptopodin-deficient neurons revealed that synaptopodin is required for the stability but not the formation of SHPs. The effects of synaptopodin could be linked to its role in Ca(2+) homeostasis, since spines with protrusions often contained ryanodine receptors and synaptopodin. Furthermore, disrupting Ca(2+) signaling shortened protrusion lifetime. By transgenically reintroducing synaptopodin on a synaptopodin-deficient background, SHP stability could be rescued. Overall, we show that synaptopodin increases the stability of SHPs, and could potentially modulate the rewiring of microcircuitries by making synaptic reorganization more efficient. PMID:27102112

  17. Membrane Protrusion Coarsening and Nanotubulation within Giant Unilamellar Vesicles

    KAUST Repository

    Węgrzyn, Ilona

    2011-11-16

    Hydrophobic side groups on a stimuli-responsive polymer, encapsulated within a single giant unilamellar vesicle, enable membrane attachment during compartment formation at elevated temperatures. We thermally modulated the vesicle through implementation of an IR laser via an optical fiber, enabling localized directed heating. Polymer-membrane interactions were monitored using confocal imaging techniques as subsequent membrane protrusions occurred and lipid nanotubes formed in response to the polymer hydrogel contraction. These nanotubes, bridging the vesicle membrane to the contracting hydrogel, were retained on the surface of the polymer compartment, where they were transformed into smaller vesicles in a process reminiscent of cellular endocytosis. This development of a synthetic vesicle system containing a stimuli-responsive polymer could lead to a new platform for studying inter/intramembrane transport through lipid nanotubes. © 2011 American Chemical Society.

  18. Paraplegia by Acute Cervical Disc Protrusion after Lumbar Spine Surgery.

    Directory of Open Access Journals (Sweden)

    Sheng-Huan Chen

    2005-04-01

    Full Text Available Non-traumatic paraplegia caused by herniation of the cervical intervertebral disc is anuncommon postoperative complication. A patient with claudication and radiculopathy wasscheduled for lumbar laminectomy due to spinal stenosis. Postoperatively, numbness belowT6 was found in his both legs of the patient. MRI showed a protruded intervertebral discbetween C6 and C7. Despite urgent disectomy, the patient's lower extremities remained paralyzedwithout significant improvement for 3 months. Loss of muscle support during generalanesthesia, excessive neck extension during endotracheal intubation and positioning, as wellas bucking and agitation are believed as triggering factors for the protrusion of the cervicaldisc. We suggest that a complete history taking and physical examination be accomplishedin patients scheduled for lumbar spine surgery in order to exclude coexisting cervical spinedisorders. In addition, skillful endotracheal intubation and careful neck positioning aremandatory for patients receiving surgery in the prone position.

  19. Treatment of Protrusion of the Lumbar Intervertebral Disc by TCM Massage

    Institute of Scientific and Technical Information of China (English)

    龙亚军

    2002-01-01

    @@ Protrusion of the lumbar intervertebral disc is a common disorder frequently encountered in clinic. With TCM massage and the maneuver of manual reduction, we have treated 82 cases of protrusion of the lumbar intervertebral disc, with satisfactory therapeutic results reported in the following.

  20. Infantil perineal protrusion er et harmløst fund med flere differentialdiagnoser

    DEFF Research Database (Denmark)

    Haastrup, Maija Dalgaard; Bygum, Anette

    2011-01-01

    Among girls the frequency of infantile perineal protrusion (IPP) is 13%. The skin-coloured protrusion is thought to represent a congenital weakness in the perineum and usually resolves spontaneously. We report a case of a 13 year-old girl who for nine years had been examined and treated for...

  1. A Silicon-Based Nanothin Film Solid Oxide Fuel Cell Array with Edge Reinforced Support for Enhanced Thermal Mechanical Stability.

    Science.gov (United States)

    Baek, Jong Dae; Yu, Chen-Chiang; Su, Pei-Chen

    2016-04-13

    A silicon-based micro-solid oxide fuel cell (μ-SOFC) with electrolyte membrane array embedded in a thin silicon supporting membrane, featuring a unique edge reinforcement structure, was demonstrated by utilizing simple silicon micromachining processes. The square silicon supporting membrane, fabricated by combining deep reactive ion etching and through-wafer wet etching processes, has thicker edges and corners than the center portion of the membrane, which effectively improved the mechanical stability of the entire fuel cell array during cell fabrication and cell operation. The 20 μm thick single crystalline silicon membrane supports a large number of 80 nm thick free-standing yttria-stabilized zirconia (YSZ) electrolytes. The fuel cell array was stably maintained at the open circuit voltage (OCV) of 1.04 V for more than 30 h of operation at 350 °C. A high peak power density of 317 mW/cm(2) was obtained at 400 °C. During a rigorous in situ thermal cycling between 150 and 400 °C at a fast cooling and heating rate of 25 °C/min, the OCV of the μ-SOFC recovered to its high value of 1.07 V without any drop caused by membrane failure, which justifies the superior thermal stability of this novel cell architecture. PMID:26990604

  2. The dinoflagellate Prorocentrum cordatum at the edge of the salinity tolerance: The growth is slower but cells are larger

    Science.gov (United States)

    Olenina, Irina; Vaičiukynas, Evaldas; Šulčius, Sigitas; Paškauskas, Ričardas; Verikas, Antanas; Gelžinis, Adas; Bačauskienė, Marija; Bertašiūtė, Vilma; Olenin, Sergej

    2016-01-01

    In this study we examine how the projected climate change driven decrease in the Baltic Sea salinity can impact the growth, cell size and shape of the recently invaded dinoflagellate Prorocentrum cordatum. In laboratory treatments we mimicked salinity conditions at the edge of the mesohaline south-eastern Baltic and oligohaline-to-limnic Curonian Lagoon. We used an innovative computer-based method allowing detection of P. cordatum cells and quantitative characterization of cell contours in phytoplankton images. This method also made available robust indicators of the morphometric changes, which are not accessible for an expert studying cells under light microscope. We found that the salinity tolerance limit of P. cordatum ranges between 1.8 and 3.6, and that the mean cell size of its population is inversely proportional to both salinity and nutrient content. Under ambient south-eastern Baltic salinity (7.2) the nutrients were stimulating the growth of P. cordatum; while at the edge of its salinity tolerance the nutrient availability did not have such effect. We suggest that in the future Baltic the decline in salinity and increase in nutrient loads may result in larger cells of P. cordatum and extended duration of their presence in plankton, causing longer periods of algal blooms.

  3. Soft X-ray radiation effects on yeast cells with energies on and off the O K absorption edge by a soft X-ray microprobe

    International Nuclear Information System (INIS)

    The cell killing abilities of soft X-rays on and off the oxygen K-shell edges on yeast cells have been investigated using a micrometer soft X-ray microprobe from synchrotron radiation. The dose depositions at different X-ray energies in the cell were discussed. At the same time, the cells were irradiated by 60Co gamma-rays and the abilities in inducing yeast cell killing were compared with those produced by soft X-rays. The results showed that soft X-rays on and off the O K edge had higher ability of radiation damage than 60Co gamma-rays. The total killing abilities of the three soft X-rays on yeast cells were almost similar and the differences of the X-rays in inducing yeast cell killing on and off the O K edge were not obvious. (authors)

  4. Independently evolved upper jaw protrusion mechanisms show convergent hydrodynamic function in teleost fishes.

    Science.gov (United States)

    Staab, Katie Lynn; Holzman, Roi; Hernandez, L Patricia; Wainwright, Peter C

    2012-05-01

    A protrusible upper jaw has independently evolved multiple times within teleosts and has been implicated in the success of two groups in particular: Acanthomorpha and Cypriniformes. We use digital particle image velocimetry (DPIV) to compare suction feeding flow dynamics in a representative of each of these clades: goldfish and bluegill. Using DPIV, we contrast the spatial pattern of flow, the temporal relationship between flow and head kinematics, and the contribution of jaw protrusion to the forces exerted on prey. As expected, the spatial patterns of flow were similar in the two species. However, goldfish were slower to reach maximal kinematic excursions, and were more flexible in the relative timing of jaw protrusion, other jaw movements and suction flows. Goldfish were also able to sustain flow speeds for a prolonged period of time as compared with bluegill, in part because goldfish generate lower peak flow speeds. In both species, jaw protrusion increased the force exerted on the prey. However, slower jaw protrusion in goldfish resulted in less augmentation of suction forces. This difference in force exerted on prey corresponds with differences in trophic niches and feeding behavior of the two species. The bluegill uses powerful suction to capture insect larvae whereas the goldfish uses winnowing to sort through detritus and sediment. The kinethmoid of goldfish may permit jaw protrusion that is independent of lower jaw movement, which could explain the ability of goldfish to decouple suction flows (due to buccal expansion) from upper jaw protrusion. Nevertheless, our results show that jaw protrusion allows both species to augment the force exerted on prey, suggesting that this is a fundamental benefit of jaw protrusion to suction feeders. PMID:22496281

  5. Cutting edge: B220+CCR9- dendritic cells are not plasmacytoid dendritic cells but are precursors of conventional dendritic cells.

    Science.gov (United States)

    Segura, Elodie; Wong, June; Villadangos, José A

    2009-08-01

    Mouse lymphoid organs contain two major subsets of dendritic cells (DC) that differ in their phenotype and functions: conventional DC (cDC) and plasmacytoid DC (pDC). Recently, it has been proposed that differential expression of CCR9 could distinguish functionally distinct pDC subsets. We show that B220(+)CCR9(-) DC do not express classical pDC markers and have a developmental origin different from that of pDC. Furthermore, B220(+)CCR9(-) DC do not secrete IFN-alpha in response to CpG and, unlike pDC, can efficiently present exogenous Ags. Our results demonstrate that B220(+)CCR9(-) DC do not represent a subset of pDC. After in vivo transfer, these cells down-regulate B220 expression and convert into the two major cDC subsets, showing that they are a developmental stage of cDC differentiation. PMID:19570827

  6. FGFR4 GLY388 isotype suppresses motility of MDA-MB-231 breast cancer cells by EDG-2 gene repression.

    Science.gov (United States)

    Stadler, Christiane Regina; Knyazev, Pjotr; Bange, Johannes; Ullrich, Axel

    2006-06-01

    Clinical investigations of an FGFR4 germline polymorphism, resulting in substitution of glycine by arginine at codon 388 (G388 to R388), have shown a correlation between FGFR4 R388 and aggressive disease progression in cancer patients. Here, we studied the differential effects of the two FGFR4 isotypes on cellular signalling and motility in the MDA-MB-231 human breast cancer cell model. cDNA array analysis showed the ability of FGFR4 G388 to suppress expression of specific genes involved in invasiveness and motility. Further investigations concentrating on cell signalling and motility revealed an abrogation of phosphatidylinositol-3-kinase-dependent LPA-induced Akt activation and cell migration due to downregulation of the LPA receptor Edg-2 in FGFR4 G388-expressing MDA-MB-231 cells. Moreover, FGFR4 G388 expression attenuated the invasivity of the breast cancer cell line and decreased small Rho GTPase activity. We conclude that FGFR4 G388 suppresses cell motility of invasive breast cancer cells by altering signalling pathways and the expression of genes that are required for metastasis. Therefore, the positive effect of FGFR4 R388 on disease progression appears to result from a loss of the tumour suppressor activity displayed by FGFR4 G388 rather than the acquisition or enhancement of oncogenic potential. PMID:16109476

  7. Observation of a Ag protrusion on a Ag2S island using a scanning tunneling microscope

    OpenAIRE

    Takeo Ohno; Tsuyoshi Hasegawa

    2015-01-01

    A silver sulfide (Ag2S) island as an ionic conductor in resistive switching memories was formed and a protrusion of silver from the Ag2S formed by an electrochemical reaction was observed using a scanning tunneling microscope.

  8. TCM Treatment for Protrusion of Lumbar Intervertebral Disc——A Report of 100 Cases

    Institute of Scientific and Technical Information of China (English)

    Li Xiang; Li Xulin; Hou Fengmei; Jia Guoqing

    2006-01-01

    @@ Since the year of 2003,100 cases of protrusion of lumbar intervertebral disc (PLID) have been treated in our department by using Chinese drugs combined with massotherapy, with quite good therapeutic results reported as follows.

  9. TCM Treatment for 50 Cases of Acute Protrusion of the Lumbar Intervertebral Disc

    Institute of Scientific and Technical Information of China (English)

    梁述元

    2001-01-01

    @@ From January 1998 to August 2000, the author has treated 50 cases of acute protrusion of the lumbar intervertebral disc by Chinese herbs, massotherapy, and functional exercise with satisfactory therapeutic results reported in the following.

  10. The current distribution in an electrochemical cell. Part V. The determination of the depth of the current line penetration between the edges of the electrodes and the side walls of the cell

    Directory of Open Access Journals (Sweden)

    TANJA M. KOSTIC

    1999-12-01

    Full Text Available A method for the calculation of the depth of the current line penetration between the edges of the electrodes and the side walls of the cell in a cell with plane parallel electrode arrangement is proposed. The method is verified by the calculation of the polarization curves for the cells in which the electrode edges do not touch the side walls of the cell. The agreement between the calculated and the measured values was fair.

  11. Color canals modification with canny edge detection and morphological reconstruction for cell nucleus segmentation and area measurement in normal Pap smear images

    Science.gov (United States)

    Riana, Dwiza; Dewi, Dyah Ekashanti Octorina; Widyantoro, Dwi H.; Mengko, Tati Latifah R.

    2014-03-01

    This paper presents a cell nucleus segmentation and area measurement of Pap smear images by means of modification of color canals with Canny edge detection and morphological reconstruction methods. Cell nucleus characterization plays an important role for classifying the degree of abnormality in cervical cancer. The aim of this work is to find the matched measurement method with the manual nucleus area measurement. In this work, we utilized pap smear single cell images from Herlev data bank in RGB mode. The cell images were selected from 90 normal class subjects that include: Normal Superficial, Normal Intermediate, and Normal Columnar classes. The nucleus of each cell image was cropped manually to localize from the cytoplasm. The color canals modification was performed on each cropped nucleus image by, first, separating each R, G, B, and grayscale canals, then implementing addition operation based on color canals (R+G+B, R+G, R+B, G+B, and grayscale). The Canny edge detection was applied on those modifications resulting in binary edge images. The nucleus segmentation was implemented on the edge images by performing region filling based on morphological reconstruction. The area property was calculated based on the segmented nucleus area. The nucleus area from the proposed method was verified to the existing manual measurement (ground truth) of the Herlev data bank. Based on thorough observation upon the selected color canals and Canny edge detection. It can be concluded that Canny edge detection with R+G+B canal is the most significant for all Normal classes (r 0,305, p-value 0.05). While for Normal Superficial and Normal Intermediate, Canny edge detection is significant for all RGB modifications with (r 0.414 - 0.817 range, , p-value 0.05), and for Normal Columnar, Canny edge detection is significant for R+B canal (r 0.505, p-value 0.05).

  12. Point-Like Protrusion as a Prestalk Intermediate in Membrane Fusion Pathway

    OpenAIRE

    Efrat, Avishay; Chernomordik, Leonid V; Kozlov, Michael M.

    2007-01-01

    The widely accepted pathway of membrane fusion begins with the fusion stalk representing the initial intermediate of hemifusion. The lipid structures preceding hemifusion and their possible influence on fusion kinetics were not addressed. Here, we suggest the point-like protrusion as a prestalk fusion intermediate, which has energy lower than that of stalk and, therefore, does not limit the fusion rate. We demonstrate that by calculating the energy of the point-like protrusion, which depends ...

  13. Study on different surgical approaches for acute Lumber disk protrusion combined with Cauda Equina Syndrome

    OpenAIRE

    Shen, Lianbing; Fang, Liangqin; Qiu, YiHua; Xing, Shunming; Chen, Dechun; He, Xiang; Wang, Jinxin; Lai, Jing; Shi, Guohua; Zhang, Jiefeng; Liao, Teng; Tan, Junming

    2014-01-01

    To compare the long and short term effectiveness and complications of different surgical approaches for Lumber disk protrusion combined with Cauda Equina Syndrome and find a better surgical method for the disease. In this study, follow up records of 144 patients received conventional laminectomy and minimally invasive decompression and fenestration 48 hours within acute injury of lumber disk protrusion combined with Cauda Equina Syndrome were analyzed. Surgical outcome immediately and 3, 6, 1...

  14. TREATMENT OF 20 CASES OF ACUTE LUMBAR DISC PROTRUSION WITH YIN THERAPY FOR YANG DISORDER

    Institute of Scientific and Technical Information of China (English)

    TAO Jing; KANG Ming-fei; ZHAO Rong

    2006-01-01

    @@ Lumbar disc protrusion is one of the common reasons of lumbar and leg pain. How to alleviate acute pain effectively is the major problem encountered in the clinical medicine. From June 2005 to March 2006, yin therapy for yang disorder had been adopted in the treatment of 20 cases of acute lumbar disc protrusion and the significant therapeutic effects had been achieved. The report is as follows.

  15. Cutting Edge: Engineering Active IKKβ in T Cells Drives Tumor Rejection.

    Science.gov (United States)

    Evaristo, César; Spranger, Stefani; Barnes, Sarah E; Miller, Michelle L; Molinero, Luciana L; Locke, Frederick L; Gajewski, Thomas F; Alegre, Maria-Luisa

    2016-04-01

    Acquired dysfunction of tumor-reactive T cells is one mechanism by which tumors can evade the immune system. Identifying and correcting pathways that contribute to such dysfunction should enable novel anticancer therapy design. During cancer growth, T cells show reduced NF-κB activity, which is required for tumor rejection. Impaired T cell-intrinsic NF-κB may create a vicious cycle conducive to tumor progression and further T cell dysfunction. We hypothesized that forcing T cell-intrinsic NF-κB activation might break this cycle and induce tumor elimination. NF-κB was activated in T cells by inducing the expression of a constitutively active form of the upstream activator IκB kinase β (IKKβ). T cell-restricted constitutively active IKKβ augmented the frequency of functional tumor-specific CD8(+) T cells and improved tumor control. Transfer of constitutively active IKKβ-transduced T cells also boosted endogenous T cell responses that controlled pre-established tumors. Our results demonstrate that driving T cell-intrinsic NF-κB can result in tumor control, thus identifying a pathway with potential clinical applicability. PMID:26903482

  16. Cutting Edge: Redox Signaling Hypersensitivity Distinguishes Human Germinal Center B Cells.

    Science.gov (United States)

    Polikowsky, Hannah G; Wogsland, Cara E; Diggins, Kirsten E; Huse, Kanutte; Irish, Jonathan M

    2015-08-15

    Differences in the quality of BCR signaling control key steps of B cell maturation and differentiation. Endogenously produced H2O2 is thought to fine tune the level of BCR signaling by reversibly inhibiting phosphatases. However, relatively little is known about how B cells at different stages sense and respond to such redox cues. In this study, we used phospho-specific flow cytometry and high-dimensional mass cytometry (CyTOF) to compare BCR signaling responses in mature human tonsillar B cells undergoing germinal center (GC) reactions. GC B cells, in contrast to mature naive B cells, memory B cells, and plasmablasts, were hypersensitive to a range of H2O2 concentrations and responded by phosphorylating SYK and other membrane-proximal BCR effectors in the absence of BCR engagement. These findings reveal that stage-specific redox responses distinguish human GC B cells. PMID:26157177

  17. Heat transfer enhancement of free surface MHD-flow by a protrusion wall

    International Nuclear Information System (INIS)

    Due to the magnetohydrodynamic (MHD) effect on the flow, which degrades heat transfer coefficients by pulsation suppression of external magnetic field on the flow, a hemispherical protrusion wall is applied to free surface MHD-flow system as a heat transfer enhancement, because the hemispherical protrusion wall has some excellent characteristics including high heat transfer coefficients, low friction factors and high overall thermal performances. So, the characteristics of the fluid flow and heat transfer of the free surface MHD-flow with hemispherical protrusion wall are simulated numerically and the influence of some parameters, such as protrusion height δ/D, and Hartmann number, are also discussed in this paper. It is found that, in the range of Hartmann number 30 ≤ Ha ≤ 70, the protrusion wall assemblies can achieve heat transfer enhancements (Nu/Nu0) of about 1.3-2.3 relative to the smooth channel, while the friction loss (f/f0) increases by about 1.34-1.45. Thus, the high Nusselt number can be obtained when the protrusion wall with a radically lower friction loss increase, which may help get much higher overall thermal performances.

  18. Formation of chloroplast protrusions and catalase activity in alpine Ranunculus glacialis under elevated temperature and different CO2/O2 ratios

    OpenAIRE

    Buchner, Othmar; Moser, Tim; Karadar, Matthias; Roach, Thomas; Kranner, Ilse; Holzinger, Andreas

    2015-01-01

    Chloroplast protrusions (CPs) have frequently been observed in plants, but their significance to plant metabolism remains largely unknown. We investigated in the alpine plant Ranunculus glacialis L. treated under various CO2 concentrations if CP formation is related to photorespiration, specifically focusing on hydrogen peroxide (H2O2) metabolism. Immediately after exposure to different CO2 concentrations, the formation of CPs in leaf mesophyll cells was assessed and correlated to catalase (C...

  19. How Shigella Utilizes Ca2+ Jagged Edge Signals during Invasion of Epithelial Cells

    OpenAIRE

    Bonnet, Mariette; Tran Van Nhieu, Guy

    2016-01-01

    Shigella, the causative agent of bacillary dysentery invades intestinal epithelial cells using a type III secretion system (T3SS). Through the injection of type III effectors, Shigella manipulates the actin cytoskeleton to induce its internalization in epithelial cells. At early invasion stages, Shigella induces atypical Ca2+ responses confined at entry sites allowing local cytoskeletal remodeling for bacteria engulfment. Global Ca2+ increase in the cell triggers the opening of connexin hemic...

  20. Cutting Edge: Integrin α4 Is Required for Regulatory B Cell Control of Experimental Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Glatigny, Simon; Wagner, Catriona A; Bettelli, Estelle

    2016-05-01

    The neutralization of integrin α4 (Itga4) is currently used as treatment in multiple sclerosis. Although most studies have focused on its function on lymphocyte migration to the CNS, we have uncovered the importance of Itga4 for the generation of regulatory B cells in peripheral immune organs and their control of pathogenic T cell response and CNS pathology. Our study underscores the importance of looking at the dual role of B cells in CNS autoimmunity and provides important perspectives regarding the efficacy and side effects associated with Itga4 neutralization and other B cell-targeting therapies. PMID:27016608

  1. Cutting Edge: Resident Memory CD8 T Cells Express High-Affinity TCRs.

    Science.gov (United States)

    Frost, Elizabeth L; Kersh, Anna E; Evavold, Brian D; Lukacher, Aron E

    2015-10-15

    Tissue-resident memory T (TRM) cells serve as vanguards of antimicrobial host defense in nonlymphoid tissues, particularly at barrier epithelia and in organs with nonrenewable cell types (e.g., brain). In this study, we asked whether an augmented ability to sense Ag complemented their role as early alarms of pathogen invasion. Using mouse polyomavirus, we show that brain-resident mouse polyomavirus-specific CD8 T cells, unlike memory cells in the spleen, progressively increase binding to MHC class I tetramers and CD8 coreceptor expression. Using the two-dimensional micropipette adhesion-frequency assay, we show that TRM cells in brain, as well as in kidney, express TCRs with up to 20-fold higher affinity than do splenic memory T cells, whereas effector cells express TCRs of similar high affinity in all organs. Together, these data demonstrate that TRM cells retain high TCR affinity, which endows them with the high Ag sensitivity needed for front-line defense against infectious agents. PMID:26371252

  2. Cutting edge: Bcl6-interacting corepressor contributes to germinal center T follicular helper cell formation and B cell helper function.

    Science.gov (United States)

    Yang, Jessica A; Tubo, Noah J; Gearhart, Micah D; Bardwell, Vivian J; Jenkins, Marc K

    2015-06-15

    CD4(+) germinal center (GC)-T follicular helper (Tfh) cells help B cells become long-lived plasma cells and memory cells. The transcriptional repressor Bcl6 plays a key role in GC-Tfh formation by inhibiting the expression of genes that promote differentiation into other lineages. We determined whether BCOR, a component of a Polycomb repressive complex that interacts with the Bcl6 BTB domain, influences GC-Tfh differentiation. T cell-targeted BCOR deficiency led to a substantial loss of peptide:MHC class II-specific GC-Tfh cells following Listeria monocytogenes infection and a 2-fold decrease following immunization with a peptide in CFA. The reduction in GC-Tfh cells was associated with diminished plasma cell and GC B cell formation. Thus, T cell-expressed BCOR is critical for optimal GC-Tfh cell differentiation and humoral immunity. PMID:25964495

  3. Cutting Edge: AhR Is a Molecular Target of Calcitriol in Human T Cells.

    Science.gov (United States)

    Takami, Mariko; Fujimaki, Kotaro; Nishimura, Michael I; Iwashima, Makio

    2015-09-15

    The immunoregulatory functions of vitamin D have been well documented in various immunological disorders, including multiple sclerosis, arthritis, and asthma. IL-10 is considered a chief effector molecule that promotes the vitamin D-induced immunosuppressive states of T cells and accessory cells. In this article, we demonstrate that the active form of vitamin D, 1,25-dihydroxyvitamin D3 (calcitriol), has a profound inhibitory effect on the development of human Th9, a CD4 T cell subset that is highly associated with asthma, in an IL-10-independent manner. Our data show that calcitriol represses the expression of BATF, a transcription factor essential for Th9, via suppressing the expression of aryl hydrocarbon receptor, without an increase in IL-10. The data show a novel link between vitamin D and two key transcription factors involved in T cell differentiation. PMID:26276877

  4. Cutting edge: membrane lymphotoxin regulates CD8(+) T cell-mediated intestinal allograft rejection.

    Science.gov (United States)

    Guo, Z; Wang, J; Meng, L; Wu, Q; Kim, O; Hart, J; He, G; Zhou, P; Thistlethwaite, J R; Alegre, M L; Fu, Y X; Newell, K A

    2001-11-01

    Blocking the CD28/B7 and/or CD154/CD40 costimulatory pathways promotes long-term allograft survival in many transplant models where CD4(+) T cells are necessary for rejection. When CD8(+) T cells are sufficient to mediate rejection, these approaches fail, resulting in costimulation blockade-resistant rejection. To address this problem we examined the role of lymphotoxin-related molecules in CD8(+) T cell-mediated rejection of murine intestinal allografts. Targeting membrane lymphotoxin by means of a fusion protein, mAb, or genetic mutation inhibited rejection of intestinal allografts by CD8(+) T cells. This effect was associated with decreased monokine induced by IFN-gamma (Mig) and secondary lymphoid chemokine (SLC) gene expression within allografts and spleens respectively. Blocking membrane lymphotoxin did not inhibit rejection mediated by CD4(+) T cells. Combining disruption of membrane lymphotoxin and treatment with CTLA4-Ig inhibited rejection in wild-type mice. These data demonstrate that membrane lymphotoxin is an important regulatory molecule for CD8(+) T cells mediating rejection and suggest a strategy to avoid costimulation blockade-resistant rejection. PMID:11673481

  5. Formation of Mitochondrial Outer Membrane Derived Protrusions and Vesicles in Arabidopsis thaliana

    Science.gov (United States)

    Yamashita, Akihiro; Fujimoto, Masaru; Katayama, Kenta; Yamaoka, Shohei; Tsutsumi, Nobuhiro; Arimura, Shin-ichi

    2016-01-01

    Mitochondria are dynamic organelles that have inner and outer membranes. In plants, the inner membrane has been well studied but relatively little is known about the outer membrane. Here we report that Arabidopsis cells have mitochondrial outer membrane-derived structures, some of which protrude from the main body of mitochondria (mitochondrial outer-membrane protrusions; MOPs), while others form vesicle-like structures without a matrix marker. The latter vesicle-like structures are similar to some mammalian MDVs (mitochondrial-derived vesicles). Live imaging demonstrated that a plant MDV budded off from the tip of a MOP. MDVs were also observed in the drp3a drp3b double mutant, indicating that they could be formed without the mitochondrial fission factors DRP3A and DRP3B. Double staining studies showed that the MDVs were not peroxisomes, endosomes, Golgi apparatus or trans-Golgi network (TGN). The numbers of MDVs and MOPs increased in senescent leaves and after dark treatment. Together, these results suggest that MDVs and MOPs are related to leaf senescence. PMID:26752045

  6. Formation of Mitochondrial Outer Membrane Derived Protrusions and Vesicles in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Akihiro Yamashita

    Full Text Available Mitochondria are dynamic organelles that have inner and outer membranes. In plants, the inner membrane has been well studied but relatively little is known about the outer membrane. Here we report that Arabidopsis cells have mitochondrial outer membrane-derived structures, some of which protrude from the main body of mitochondria (mitochondrial outer-membrane protrusions; MOPs, while others form vesicle-like structures without a matrix marker. The latter vesicle-like structures are similar to some mammalian MDVs (mitochondrial-derived vesicles. Live imaging demonstrated that a plant MDV budded off from the tip of a MOP. MDVs were also observed in the drp3a drp3b double mutant, indicating that they could be formed without the mitochondrial fission factors DRP3A and DRP3B. Double staining studies showed that the MDVs were not peroxisomes, endosomes, Golgi apparatus or trans-Golgi network (TGN. The numbers of MDVs and MOPs increased in senescent leaves and after dark treatment. Together, these results suggest that MDVs and MOPs are related to leaf senescence.

  7. Repulsive axon guidance cues ephrin-A2 and slit3 stop protrusion of the growth cone leading margin concurrently with inhibition of ADF/cofilin and ERM proteins

    OpenAIRE

    Marsick, Bonnie M.; Roche, Florence K.; Letourneau, Paul C.

    2012-01-01

    Axonal growth cones turn away from repulsive guidance cues. This may start with reduced protrusive motility in the region the growth cone leading margin that is closer to the source of repulsive cue. Using explants of E7 chick temporal retina, we examine the effects of two repulsive guidance cues, ephrin-A2 and slit3, on retinal ganglion cell growth cone protrusive activity, total F-actin, free F-actin barbed ends, and the activities (phosphorylation states) of actin regulatory proteins, ADF/...

  8. Cutting edge: neuronal recognition by CD8 T cells elicits central diabetes insipidus.

    Science.gov (United States)

    Scheikl, Tanja; Pignolet, Béatrice; Dalard, Cécile; Desbois, Sabine; Raison, Danièle; Yamazaki, Masanori; Saoudi, Abdelhadi; Bauer, Jan; Lassmann, Hans; Hardin-Pouzet, Hélène; Liblau, Roland S

    2012-05-15

    An increasing number of neurologic diseases is associated with autoimmunity. The immune effectors contributing to the pathogenesis of such diseases are often unclear. To explore whether self-reactive CD8 T cells could attack CNS neurons in vivo, we generated a mouse model in which the influenza virus hemagglutinin (HA) is expressed specifically in CNS neurons. Transfer of cytotoxic anti-HA CD8 T cells induced an acute but reversible encephalomyelitis in HA-expressing recipient mice. Unexpectedly, diabetes insipidus developed in surviving animals. This robust phenotype was associated with preferential accumulation of cytotoxic CD8 T cells in the hypothalamus, upregulation of MHC class I molecules, and destruction of vasopressin-expressing neurons. IFN-γ production by the pathogenic CD8 T cells was necessary for MHC class I upregulation by hypothalamic neurons and their destruction. This novel mouse model, in combination with related human data, supports the concept that autoreactive CD8 T cells can trigger central diabetes insipidus. PMID:22504649

  9. Cdc42-dependent leading edge coordination is essential for interstitial dendritic cell migration

    DEFF Research Database (Denmark)

    Lammermann, Tim; Renkawitz, Jorg; Wu, Xunwei; Hirsch, Karin; Brakebusch, Cord; Sixt, Michael

    2009-01-01

    Mature dendritic cells (DCs) moving from the skin to the lymph node are a prototypic example of rapidly migrating amoeboid leukocytes. Interstitial DC migration is directionally guided by chemokines, but independent of specific adhesive interactions with the tissue as well as pericellular...

  10. An adhesion-dependent switch between mechanisms that determine motile cell shape.

    Directory of Open Access Journals (Sweden)

    Erin L Barnhart

    2011-05-01

    Full Text Available Keratocytes are fast-moving cells in which adhesion dynamics are tightly coupled to the actin polymerization motor that drives migration, resulting in highly coordinated cell movement. We have found that modifying the adhesive properties of the underlying substrate has a dramatic effect on keratocyte morphology. Cells crawling at intermediate adhesion strengths resembled stereotypical keratocytes, characterized by a broad, fan-shaped lamellipodium, clearly defined leading and trailing edges, and persistent rates of protrusion and retraction. Cells at low adhesion strength were small and round with highly variable protrusion and retraction rates, and cells at high adhesion strength were large and asymmetrical and, strikingly, exhibited traveling waves of protrusion. To elucidate the mechanisms by which adhesion strength determines cell behavior, we examined the organization of adhesions, myosin II, and the actin network in keratocytes migrating on substrates with different adhesion strengths. On the whole, our results are consistent with a quantitative physical model in which keratocyte shape and migratory behavior emerge from the self-organization of actin, adhesions, and myosin, and quantitative changes in either adhesion strength or myosin contraction can switch keratocytes among qualitatively distinct migration regimes.

  11. The value of accurate clinical assessment in the surgical management of the lumbar disc protrusion.

    Science.gov (United States)

    Kerr, R S; Cadoux-Hudson, T A; Adams, C B

    1988-02-01

    One hundred patients with lumbar disc protrusions were studied. Thirty six "control" patients were admitted in the same time period with low back pain and sciatica but with subsequently "normal" myelograms and no surgery. The aim of this paper was to relate history and clinical signs to the myelograms and surgical findings. Ninety nine per cent of our patients presented with sciatica (controls 94%). The most frequently found sign in patients with a disc protrusion was reduction of ipsilateral straight leg raising (98%). However, 55% of controls also showed this sign. There were three signs that, when present, particularly indicated a disc protrusion; "crossed straight leg raising" (pain on contralateral straight leg raising), measured calf wasting and impaired ankle reflex: the latter being especially indicative of an L5-S1 disc protrusion. There were two further important signs, weakness of dorsiflexion of the foot and scoliosis of the lumbar spine. However, such signs occurred in about half the patients and so clinical diagnosis in the remaining half depended on obtaining a good history of sciatica, and paying due regard to severity of the pain, the mobility of the patient, the ability and desire to work and the overall personality. Satisfactory results of surgery simply depend on finding and removing a definite disc protrusion. Using these methods of selection, 98% have returned to their original employment, 86% within 3 months of the operation. For a patient with no abnormal signs and a normal myelogram, surgical treatment should not be advised. PMID:3346682

  12. Numerical Investigation of Non-Newtonian Flow and Heat Transfer Characteristics in Rectangular Tubes with Protrusions

    Directory of Open Access Journals (Sweden)

    Yonghui Xie

    2015-01-01

    Full Text Available Flow characteristics and heat transfer performances in rectangular tubes with protrusions are numerically investigated in this paper. The thermal heat transfer enhancement of composite structures and flow resistance reduction of non-Newtonian fluid are taken advantage of to obtain a better thermal performance. Protrusion channels coupled with different CMC concentration solutions are studied, and the results are compared with that of smooth channels with water flow. The comprehensive influence of turbulence effects, structural effects, and secondary flow effects on the CMC’s flow in protrusion tubes is extensively investigated. The results indicate that the variation of flow resistance parameters of shear-thinning power-law fluid often shows a nonmonotonic trend, which is different from that of water. It can be concluded that protrusion structure can effectively enhance the heat transfer of CMC solution with low pressure penalty in specific cases. Moreover, for a specific protrusion structure and a fixed flow velocity, there exists an optimal solution concentration showing the best thermal performance.

  13. Longitudinal Dependance Of Solsticial Hadley Cell Detected At The Edge Of The Massive Martian Erg

    CERN Document Server

    Kuassivi, M

    2011-01-01

    Using public HIRISE images of MARS, I derive the wind directions at high Northern lattitudes, where many interesting eolian features are observed. BArchan dunes show prominent wind direction from the North indicating that they formed during the southern summer. But a few record consistent SE winds near the UTOPIA PLANITIA basin. The wind reversal is consistent with a local perturbation of the solsticial Hadley cell caused by geological depression.

  14. Cytosolic pressure provides a propulsive force comparable to actin polymerization during lamellipod protrusion

    OpenAIRE

    Daphne Manoussaki; Shin, William D.; Waterman, Clare M.; Richard S Chadwick

    2015-01-01

    Does cytosolic pressure facilitate f-actin polymerization to push the leading edge of a cell forward during self-propelled motion? AFM force-distance (f-d) curves obtained from lamellipodia of live cells often exhibit a signal from which the tension, bending modulus, elastic modulus and thickness in the membrane-cortex complex can be estimated close to the contact point. These measurements permit an estimate of the cytosolic pressure via the canonical Laplace force balance. The deeper portion...

  15. Edge-nitrogenated graphene nanoplatelets as high-efficiency counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Wang, Guiqiang; Zhang, Juan; Hou, Shuo; Zhang, Wei; Zhao, Zengdian

    2016-05-01

    Edge-nitrogenated graphene nanoplatelets (ENGNPs) are prepared by a simple and eco-friendly mechanochemical pin-grinding process using flake graphite as the precursor in the presence of nitrogen and investigated as the counter electrodes of dye-sensitized solar cells (DSCs). SEM images and nitrogen adsorption analysis indicate an effective and spontaneous delamination of the pristine graphite into small graphene nanoplatelets by a mechanochemical pin-grinding process. The mechanochemical cracking of the graphitic C-C bond generates activated carbon sites that react directly with nitrogen at the broken edges. The resultant ENGNPs are deposited on a fluorine-doped tin oxide (FTO) substrate by spray coating, and their electrocatalytic activities are investigated systemically in the I-/I3- redox electrolyte. Electrochemical measurements show that the ENGNP electrode possesses excellent electrocatalytic activity for the redox reaction of I-/I3- as evidenced by the low charge-transfer resistance at the interface of the electrode and electrolyte. Under 100 mW cm-2 illumination, the DSC with the optimized ENGNP counter electrode achieves a conversion efficiency of 7.69%, which is comparable to that of the device with Pt counter electrode.Edge-nitrogenated graphene nanoplatelets (ENGNPs) are prepared by a simple and eco-friendly mechanochemical pin-grinding process using flake graphite as the precursor in the presence of nitrogen and investigated as the counter electrodes of dye-sensitized solar cells (DSCs). SEM images and nitrogen adsorption analysis indicate an effective and spontaneous delamination of the pristine graphite into small graphene nanoplatelets by a mechanochemical pin-grinding process. The mechanochemical cracking of the graphitic C-C bond generates activated carbon sites that react directly with nitrogen at the broken edges. The resultant ENGNPs are deposited on a fluorine-doped tin oxide (FTO) substrate by spray coating, and their electrocatalytic

  16. Curcumin as a double-edged sword for stem cells: dose, time and cell type-specific responses to curcumin

    OpenAIRE

    Attari, Fatemeh; Zahmatkesh, Maryam; Aligholi, Hadi; Mehr, Shahram Ejtemaei; Sharifzadeh, Mohammad; Gorji, Ali; Mokhtari, Tahmineh; Khaksarian, Mojtaba; Hassanzadeh, Gholamreza

    2015-01-01

    Background The beneficial effects of curcumin which includes its antioxidant, anti-inflammatory and cancer chemo-preventive properties have been identified. Little information is available regarding the optimal dose and treatment periods of curcumin on the proliferation rate of different sources of stem cells. Methods In this study, the effect of various concentrations of curcumin on the survival and proliferation of two types of outstanding stem cells which includes bone marrow stem cells (B...

  17. Edge Matters

    DEFF Research Database (Denmark)

    Earon, Ofri

    2013-01-01

    building. The research explores and develops the architectural characteristics of correlations between the resident, the singular unit, the building and the given location at the edge zone. It approaches the edge zone of the urban house as a platform for dynamic interactions between these behaviours. The...... following text includes the first draft of the first two chapters: introduction and theory. The chapters are not written completely, and some parts are written only as headlines. These headlines and other comments are marked in red. The text is on working progress and far from being finished, but it will be...

  18. Treatment of 116 Cases of Cervical Intervertebral Disc Protrusion by Tuina

    Institute of Scientific and Technical Information of China (English)

    WANG Guang-zong; XIAO Yuan-chun

    2007-01-01

    Objective: To observe the clinical efficacy of uplifting massage therapy in the treatment of cervical intervertebral disc protrusion and study the effectiveness of this massage therapy for cervical intervertebral disc protrusion. Methods: 116 subjects were randomized into two groups: treatment group in which 60 cases were treated by uplifting massage therapy and conventional massage, and control group in which 56 cases were treated by simple conventional massage. Results: After 1-2 courses of treatment, the total effective rate was 95.0% in treatment group and 80.4% in control group; the former rate was higher than the latter one(P<0.05).Conclusion: The uplifting massage therapy combined with conventional massage has better effects than simple conventional massage in the treatment of cervical intervertebral disc protrusion.

  19. TREATMENT OF 29 CASES OF LUMBAR INTERVETEBRAL DISC PROTRUSION WITH GINGER-SEPARATED MOXIBUSTION

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lixin; LI Wanting

    2002-01-01

    Objective: To observe the effect of ginger-separated moxibustion for treatment of lumbar intervertebrai disc prolapse. Methods: 29 Iumbar intervertebral disc protrusion patients including 21 males and 8 females were treated with ginger-separated moxibustion of Ashi-point and Jiaji (EX-B 2 , the affected region), 5 - 6 cones every time, once every other day, continuously for 5 times. Then the therapeutic effect was analyzed. Results: After treatment, of the 29 cases, 23(79.3% ) were cured, and the rest 6(20.7% ) experienced improvement. Conclusion: Ginger-separated moxibustion is fairly effective and safe in treatment of lumbar intervertebral disc protrusion.

  20. Living edge

    DEFF Research Database (Denmark)

    Earon, Ofri

    2014-01-01

    “What is an edge? We can think about an edge as having been of two sorts. In one, it is a border. In the other, it is a boundary. A border is a zone of interaction where things meet and intersect. A boundary is a place where something ends” Architects and planners normally approach domestic borders...... the involved actors at the border. By doing so, the study underlines a forgotten, yet important, role of this edge zone – being a zone of commonality between the house and city, between indoors and outdoors, between the man at home and the man at the street. The city of Copenhagen promotes porous...... borders on the ground level, but there is a lack of recognition in the significance of communicative characters as well at the higher part of the edge. The city’s planning approach is “Consider urban life before urban space. Consider urban space before buildings” This urban strategy neglects the possible...

  1. A Particle-in-Cell Approach to Time Domain Simulations of the ICRF Edge Regions

    International Nuclear Information System (INIS)

    Traditional particle-in-cell / time-domain methods excel in situations of complex geometry, but are difficult to use in fusion plasma type problems, primarily because of explicit time-step algorithms that become numerically unstable when confronted with temporally or spatially unresolved physics, at high frequency and short scale-length, such as plasma oscillations and sheaths. We discuss an approach for a progressive treatment of these difficulties with carefully planned intermediate steps, each fully functional and useful in its own right. In our first year we plan to implement, in an implicit algorithm, the standard linear magnetized cold-plasma dielectric tensor in time-domain to treat the RF propagation. Particles will be pushed, but initially only for comparison purposes with the currents of the linear dielectric medium. This will permit cataloging of kinetic and non-linear departures from the linear model, while at the same time assuring numerical stability. The linear equations are identical to the fluid equations, and so subsequent upgrades involve relaxation of fluid linearity, and eventual feedback from particle information into the fluid quantities, and incorporation of new sheath boundary physics models

  2. Cutting Edge: ACVRL1 Signaling Augments CD8α+ Dendritic Cell Development.

    Science.gov (United States)

    Verma, Rohit; Jaiswal, Hemant; Chauhan, Kuldeep Singh; Kaushik, Monika; Tailor, Prafullakumar

    2016-08-15

    Dendritic cells (DCs) are a collection of different subtypes, each of which is characterized by specific surface markers, gene-expression patterns, and distinct functions. Members of the IFN regulatory factor family play critical roles in DC development and functions. Recently, Irf8 was shown to activate TGF-β signaling, which led to exacerbated neuroinflammation in the experimental autoimmune encephalomyelitis mouse model. We analyzed the effect of Irf8 on TGF-β/bone morphogenetic protein pathway-specific genes in DCs and identified Acvrl1, a type I TGF-β superfamily receptor, as a gene strongly induced by Irf8 expression. Among various DC subtypes, Acvrl1 is differentially expressed in CD8α(+) DCs. ACVRL1 signaling augmented Irf8-directed classical CD8α(+) DC development. Irf8 expression is essential for plasmacytoid DC and CD8α(+) DC development, and this study demonstrates that ACVRL1 signaling plays a pivotal role whereby it suppresses plasmacytoid DC development while enhancing that of CD8α(+) DCs, thus contributing to DC diversity development. PMID:27421479

  3. Differential Dynamics of α5 Integrin, Paxillin, and α-Actinin during Formation and Disassembly of Adhesions in Migrating Cells

    OpenAIRE

    Laukaitis, Christina M; Webb, Donna J.; Donais, Karen; Horwitz, Alan F.

    2001-01-01

    To investigate the mechanisms by which adhesions form and disperse in migrating cells, we expressed α5 integrin, α-actinin, and paxillin as green fluorescent protein (GFP) fusions. All localized with their endogenous counterparts and did not perturb migration when expressed at moderate levels. α5-GFP also rescued the adhesive defects in CHO B2 cells, which are α5 integrin deficient. In ruffling cells, α5-GFP and α-actinin–GFP localized prominently at the leading edge in membrane protrusions. ...

  4. Report of a Class I bimaxillary dental protrusion case with extraction of first premolars treated with Clarity™ SL MBT appliances

    Directory of Open Access Journals (Sweden)

    Hugo Trevisi

    2013-01-01

    Full Text Available Bimaxillary protrusion cases are common in orthodontic practice. For the best facial outcome, the biomechanics can often be challenging. A class I bimaxillary protrusion case is presented below illustrating the careful application of extractions and bracket prescription. The case highlights how self-ligating brackets and high precision bracket positioning can reduce the need for additional anchorage.

  5. Observation of a Ag protrusion on a Ag2S island using a scanning tunneling microscope

    Directory of Open Access Journals (Sweden)

    Takeo Ohno

    2015-01-01

    Full Text Available A silver sulfide (Ag2S island as an ionic conductor in resistive switching memories was formed and a protrusion of silver from the Ag2S formed by an electrochemical reaction was observed using a scanning tunneling microscope.

  6. Effect of Tongue Exercise on Protrusive Force and Muscle Fiber Area in Aging Rats

    Science.gov (United States)

    Connor, Nadine P.; Russell, John A.; Wang, Hao; Jackson, Michelle A.; Mann, Laura; Kluender, Keith

    2009-01-01

    Purpose: Age-related changes in tongue function may contribute to dysphagia in elderly people. The authors' purpose was to investigate whether aged rats that have undergone tongue exercise would manifest increased protrusive tongue forces and increased genioglossus (GG) muscle fiber cross-sectional areas. Method: Forty-eight young adult,…

  7. Epidural fat distribution patterns in patients with lumbar intervertebral disc protrusion

    Institute of Scientific and Technical Information of China (English)

    Yang Zhizhou; Zhu Xiaodong; Li Ming

    2009-01-01

    Objective: To investigate epidural fat distribution patterns in patients with lumbar intervertebral disc protrusion. Methods: Medical records were selected randomly from 30 patients whose diagnoses were consistent with the inclusion criteria of the study. Thickness of bilateral fat, the longest length of posterior fat, thickness of bilateral yellow ligament and thehernial distance of lumbar discs were measured by MRI at L3/L4, L4/L5 and LS/S 1 levels. According to clinical symptoms of lumbar intervertebral disc protrusion, the patients were divided into two groups at all space levels. All data were analyzed by statistical software. Results: The longest length of posterior epidural fat at the symptomatic levels was shorter than that at the non-symptomatic levels in each disc space. The symptomatic levels had no effect on the whole thickness of the lateral fat and lateral yellow ligaments. Conclusion: Epidural fat distribution in patients with lumbar intervertebral disc protrusion is different from that in normal adults. It is affected by the hernial distance of lumbar discs. The diagnostic criteria for spinal epidural lipomatosis in normal adults may therefore prove to be inappropriate for patients with lumbar intervertebral disc protrusion.

  8. Numerical investigation of heat transfer performance of synthetic jet impingement onto dimpled/protrusioned surface

    Directory of Open Access Journals (Sweden)

    Zhang Di

    2015-01-01

    Full Text Available Dynamic mesh methods and user defined functions are adopted and the shear stress transport k-ω turbulent model has been used in the numerical investigation of heat transfer performance of synthetic jet impingement onto dimple/protrusioned surface. The results show that the local time-averaged Nusselt number of the dimpled/protrusioned target surface tends to be much closer with that of flat cases with increasing of frequency. The heat transfer performance gets better when frequency increases. The area-averaged time-averaged Nusselt number of protrusioned target surface is the most close to that of flat cases when f = 320 Hz while it is the smallest among the synthetic jet cases in dimpled target surface. The heat transfer enhancement performance of synthetic jet is 30 times better than that of natural convection. The time-averaged Nusselt number of stagnation point in the protrusioned target surface is higher than that of flat target surface while it is lower in the dimpled surface than that of flat surface no matter in the synthetic jet, steady jet or natural convection cases. Meanwhile, the timeaveraged Nusselt number of stagnation point in the synthetic jet cases increases with the increasing of frequency. It is worth pointing out that the time-averaged Nusselt number of stagnation point is lower than that of steady cases when the frequency is low. However, it shows a bit higher than that of steady cases when f = 320 Hz.

  9. Effect of Coriolis forces in a rotating channel with dimples and protrusions

    International Nuclear Information System (INIS)

    Large-eddy simulations are used to investigate the effect of Coriolis forces and dimple depth on heat transfer and friction in a channel with dimples and protrusions on either side. Two geometries with two different dimple-protrusion depths, δ = 0.2 and 0.3 of channel height are investigated over a wide range of rotation numbers, Rob = -0.77 to 1.10 based on mean velocity and channel height. It is found that the dimple side of the channel is much more sensitive to destabilizing rotational Coriolis forces than the protrusion side of the channel, although both dimples and protrusions react to the stabilizing effects of Coriolis forces on the leading side. The dimpled surface on the trailing side experiences a large increase in heat transfer coefficient from an augmentation ratio of 1.9 for stationary flow to 3.5 at Rob = 0.77 for δ = 0.2, and from 2.3 to a maximum of 3.8 for δ = 0.3. Placing protrusion on the trailing side, however, only increases the augmentation ratio to between 3.25 and 3.7 from the stationary values of 3.0 and 3.4 for δ = 0.2 and 0.3, respectively. The dimpled leading side experiences a large drop in heat transfer to between augmentation ratios of 1.1 and 1.4 for the two dimple depths. The protrusion surface on the leading side also experiences a large drop in augmentation from 3.0 for a stationary channel to 1.3 at Rob = 0.77 for δ = 0.2 and from 3.4 to 1.8 at Rob = 1.1 for δ = 0.3. The results lead to the conclusion that for low rotation numbers |Rob| b| > 0.2, dimples on the trailing side of the duct give better overall performance. Between the two depths, the deeper dimple/protrusion (δ = 0.3) gives higher heat transfer augmentation at the price of more frictional losses ranging from 6 to 10 versus 3 to 5 for depth δ = 0.2.

  10. Premaxillary movements in cyprinodontiform fishes: an unusual protrusion mechanism facilitates "picking" prey capture.

    Science.gov (United States)

    Ferry-Graham, Lara A; Gibb, Alice C; Hernandez, L Patricia

    2008-01-01

    Premaxillary protrusion is hypothesized to confer a number of feeding advantages to teleost fishes; however, most proposed advantages relate to enhanced stealth or suction production during prey capture. Cyprinodontiformes exhibit an unusual form of premaxillary protrusion where the descending process of the premaxilla does not rotate anteriorly to occlude the sides of the open mouth during prey capture. Instead, the premaxilla is protruded such that it gives the impression of a beak during prey capture. We quantified premaxillary kinematics during feeding in four cyprinodontiform taxa and compared them with three percomorph taxa to identify any performance consequences of this protrusion mechanism. Individual prey capture events were recorded using digital high-speed video at 250-500 frames per second (n >or= 4 individuals, >or= 4 strikes per individual). Species differed in the timing of movement and the maximum displacement of the premaxilla during the gape cycle and in the contribution of the premaxilla to jaw closing. Cyprinodontiform taxa produced less premaxillary protrusion than the percomorph taxa, and were consistently slower in the time to maximum gape. Further, it appears cyprinodontiforms can alter the contribution of the premaxilla to mouth closure on an event-specific basis. We were able to demonstrate that, within at least one species, this variability is associated with the location of the prey (bottom vs. water column). Cyprinodontiform upper jaw movements likely reflect increased dexterity associated with a foraging ecology where prey items are "picked" from a variety of locations: the bottom, water column, or surface. We postulate that dexterity requires slow, precisely controlled jaw movements; thus, may be traded off for some aspects of suction-feeding performance, such as protrusion distance and speed. PMID:18619823

  11. Effect of microscale protrusions on local fluid flow and mass transport in the presence of forced convection

    Energy Technology Data Exchange (ETDEWEB)

    Matzen, G.W.

    1997-01-01

    Three-dimensional creeping flow around single, axisymmetric protrusions is studied numerically using the boundary-integral technique. Emphasis is placed upon cylindrical protrusions on plane walls for various height-to-radius (h-to-a) aspect ratios, but cones and sections of spheres protruding from plane walls are also briefly examined. The presented items include shear-stress distributions, shear-stress contours, extents of the fluid-flow disturbance, total forces and torques on the cylinders, streamlines, and skin-friction lines. Also included is a discussion of flow topology around axisymmetric geometries. No flow reversal is observed for cylindrical protrusions with aspect ratios greater than 2.4 to 2.6. At higher aspect ratios, the fluid tends to be swept around cylindrical protrusions with little vertical motion. At lower aspect ratios, the strength of the recirculation increases, and the recirculation region becomes wider in the transverse direction and narrower in the flow direction. Also, the recirculation pattern begins to resemble the closed streamline patterns in two-dimensional flow over square ridges. However, unlike two-dimensional flow, closed streamline patterns are not observed. For arbitrary axisymmetric geometries, the extent of the fluid-flow disturbance can be estimated with the total force that is exerted on the protrusion. When the same force is exerted on protrusions with different aspect ratios, the protrusion with the higher aspect ratio tends to have a greater disturbance in the flow direction and a smaller disturbance in the transverse direction. The total force exerted on cylindrical protrusions with rounded corners is only slightly lower than the total force exerted on cylindrical protrusions with sharp corners.

  12. Study on different surgical approaches for acute Lumber disk protrusion combined with Cauda Equina Syndrome.

    Science.gov (United States)

    Shen, Lianbing; Fang, Liangqin; Qiu, Yihua; Xing, Shunming; Chen, Dechun; He, Xiang; Wang, Jinxin; Lai, Jing; Shi, Guohua; Zhang, Jiefeng; Liao, Teng; Tan, Junming

    2014-01-01

    To compare the long and short term effectiveness and complications of different surgical approaches for Lumber disk protrusion combined with Cauda Equina Syndrome and find a better surgical method for the disease. In this study, follow up records of 144 patients received conventional laminectomy and minimally invasive decompression and fenestration 48 hours within acute injury of lumber disk protrusion combined with Cauda Equina Syndrome were analyzed. Surgical outcome immediately and 3, 6, 12, 36 months after the surgery were compared to evaluate the effectiveness two different approaches. The results indicated that there are no significant differences regarding age, sexual proportion, body mass index (BMI), visual analogue scale of pain (VAS) score as well as Frankel scores before the surgery, and significant differences VAS score as well as Frankel scores immediately after the surgery. In conclusion, minimally invasive decompression and fenestration can be of the same effectiveness and less complications comparing with the conventional laminectomy. PMID:25674258

  13. TREATMENT OF 29 CASES OF LUMBAR INTERVETEBRAL DISC PROTRUSION WITH GINGER—SEPARATED MOXIBUSTION

    Institute of Scientific and Technical Information of China (English)

    赵立新; 李万婷

    2002-01-01

    Objective:To observe the effect of ginger-separated moxibustion for treatment of lumbar intervertepral disc prolapse.Methods:29 lumbar intervertebral disc protrusion patients including 21 males and 8 temales were treated with ginger-separated moxibustion of Ashi-point and Jiaji(EX-B 2,.the affected region),5-6 cones every time,once every other day,continuously for 5 times,Then the therapeutic effect was analyzed.Results:After treatment,of the 29 cases,23(79.3%) were cured,and the rest 6(20.7%)experienced improvement.Conclusion:Ginger-separated moxibustion is farily effective and safe in treatment of lumbar intervertebral disc protrusion.

  14. Contrast myelography in the diagnosis of hernal protrusion of intervertebral disks in lumbar osteochondrosis

    International Nuclear Information System (INIS)

    The paper is concerned with the results of a radiopaque study of the vertebral canal in 701 patients with lumbar osteochondrosis (pneumomyelography was performed in 280, positive myelography with water soluble contrast substances in 421 patients). Myelography using Amipaque, a water soluble contrast substance, is a highly informative method of diagnosis of protrusion of disks. Amipaque is more physiological and sparing as compared to the air and emulsive contrast agents. The combination of myelography with functional X-ray investigations, and tomography permits the detection in most of the cases of protrusion of intervertebral disks. This combination is also used to determine the side of lateral hernias for a less traumatic surgical access. Diagnostic accuracy in positive myelography was 96.5%, in negative myelography 89.13%

  15. Enhancement of Heat Transfer and Thermo-Hydraulic Performance Using Triangular Protrusions as Roughness Elements

    OpenAIRE

    Nagaraju, A; Prof. B.Uma Maheswar Gowd

    2015-01-01

    Solar heat has been thrust area of research to explore renewable energy utilisation for the past few decades. In solar air heaters artificial roughness is tried on the surface of the absorber plate by adding small roughness elements to enhance the heat transfer rate. In the present work triangular protrusion are provided to act as roughness elements over the surface of the aluminum absorber plate. The experimental study is carried out on the effect of change in apex angle of protr...

  16. Spontaneous Regression of Herniated Lumbar Disc with New Disc Protrusion in the Adjacent Level

    OpenAIRE

    Hakan, Tayfun; Gürcan, Serkan

    2016-01-01

    Spontaneous regression of herniated lumbar discs was reported occasionally. The mechanisms proposed for regression of disc herniation are still incomplete. This paper describes and discusses a case of spontaneous regression of herniated lumbar discs with a new disc protrusion in the adjacent level. A 41-year-old man was admitted with radiating pain and numbness in the left lower extremity with a left posterolateral disc extrusion at L5-S1 level. He was admitted to hospital with low back pain ...

  17. Friction-induced nanofabrication method to produce protrusive nanostructures on quartz

    Science.gov (United States)

    Song, Chenfei; Li, Xiaoying; Yu, Bingjun; Dong, Hanshan; Qian, Linmao; Zhou, Zhongrong

    2011-12-01

    In this paper, a new friction-induced nanofabrication method is presented to fabricate protrusive nanostructures on quartz surfaces through scratching a diamond tip under given normal loads. The nanostructures, such as nanodots, nanolines, surface mesas and nanowords, can be produced on the target surface by programming the tip traces according to the demanded patterns. The height of these nanostructures increases with the increase of the number of scratching cycles or the normal load. Transmission electron microscope observations indicated that the lattice distortion and dislocations induced by the mechanical interaction may have played a dominating role in the formation of the protrusive nanostructures on quartz surfaces. Further analysis reveals that during scratching, a contact pressure ranged from 0.4 P y to P y ( P y is the critical yield pressure of quartz) is apt to produce protuberant nanostructures on quartz under the given experimental conditions. Finally, it is of great interest to find that the protrusive nanostructures can be selectively dissolved in 20% KOH solution. Since the nanowords can be easily 'written' by friction-induced fabrication and 'erased' through selective etching on a quartz surface, this friction-induced method opens up new opportunities for future nanofabrication.

  18. EMA: a developmentally regulated cell-surface glycoprotein of CNS neurons that is concentrated at the leading edge of growth cones.

    Science.gov (United States)

    Baumrind, N L; Parkinson, D; Wayne, D B; Heuser, J E; Pearlman, A L

    1992-08-01

    To identify cell-surface molecules that mediate interactions between neurons and their environment during neural development, we used monoclonal antibody techniques to define a developmentally regulated antigen in the central nervous system of the mouse. The antibody we produced (2A1) immunolabels cells throughout the central nervous system; we analyzed its distribution in the developing cerebral cortex, where it is expressed on cells very soon after they complete mitosis and leave the periventricular proliferative zone. Expression continues into adult life. The antibody also labels the epithelium of the choroid plexus and the renal proximal tubules, but does not label neurons of the peripheral nervous system in the dorsal root ganglia. In dissociated cell culture of embryonic cerebral cortex, 2A1 labels the surface of neurons but not glia. Immunolabeling of neurons in tissue culture is particularly prominent on the edge of growth cones, including filopodia and the leading edge of lamellipodia, when observed with either immunofluorescence or freeze-etch immunoelectron microscopy. Immunopurification with 2A1 of a CHAPS-extracted membrane preparation from brains of neonatal mice produces a broad (32-36 kD) electrophoretic band and a less prominent 70 kD band that are sensitive to N-glycosidase but not endoglycosidase H. Thus the 2A1 antibody recognizes a developmentally regulated, neuronal cell surface glycoprotein (or glycoproteins) with complex N-linked oligosaccharide side chains. We have termed the glycoprotein antigen EMA because of its prominence on the edge membrane of growth cones. EMA is similar to the M6 antigen (Lagenaur et al: J. Neurobiol. 23:71-88, 1992) in apparent molecular weight, distribution in tissue sections, and immunoreactivity on Western blots, suggesting that the two antigens are similar or identical. Expression of EMA is a very early manifestation of neuronal differentiation; its distribution on growth cones suggests a role in mediating the

  19. Spiral actin-polymerization waves can generate amoeboidal cell crawling

    International Nuclear Information System (INIS)

    Amoeboidal cell crawling on solid substrates is characterized by protrusions that seemingly appear randomly along the cell periphery and drive the cell forward. For many cell types, it is known that the protrusions result from polymerization of the actin cytoskeleton. However, little is known about how the formation of protrusions is triggered and whether the appearance of subsequent protrusions is coordinated. Recently, the spontaneous formation of actin-polymerization waves was observed. These waves have been proposed to orchestrate the cytoskeletal dynamics during cell crawling. Here, we study the impact of cytoskeletal polymerization waves on cell migration using a phase-field approach. In addition to directionally moving cells, we find states reminiscent of amoeboidal cell crawling. In this framework, new protrusions are seen to emerge from a nucleation process, generating spiral actin waves in the cell interior. Nucleation of new spirals does not require noise, but occurs in a state that is apparently displaying spatio-temporal chaos. (paper)

  20. Actin filaments at the leading edge of cancer cells are characterized by a high mobile fraction and turnover regulation by profilin I.

    Directory of Open Access Journals (Sweden)

    Gisela Lorente

    Full Text Available Cellular motility is the basis for cancer cell invasion and metastasis. In the case of breast cancer, the most common type of cancer among women, metastasis represents the most devastating stage of the disease. The central role of cellular motility in cancer development emphasizes the importance of understanding the specific mechanisms involved in this process. In this context, tumor development and metastasis would be the consequence of a loss or defect of the mechanisms that control cytoskeletal remodeling. Profilin I belongs to a family of small actin binding proteins that are thought to assist in actin filament elongation at the leading edge of migrating cells. Traditionally, Profilin I has been considered to be an essential control element for actin polymerization and cell migration. Expression of Profilin I is down-regulated in breast and various other cancer cells. In MDA-MB-231 cells, a breast cancer cell line, further inhibition of Profilin I expression promotes hypermotility and metastatic spread, a finding that contrasts with the proposed role of Profilin in enhancing polymerization. In this report, we have taken advantage of the fluorescence recovery after photobleaching (FRAP of GFP-actin to quantify and compare actin dynamics at the leading edge level in both cancer and non-cancer cell models. Our results suggest that (i a high level of actin dynamics (i.e., a large mobile fraction of actin filaments and a fast turnover is a common characteristic of some cancer cells; (ii actin polymerization shows a high degree of independence from the presence of extracellular growth factors; and (iii our results also corroborate the role of Profilin I in regulating actin polymerization, as raising the intracellular levels of Profilin I decreased the mobile fraction ratio of actin filaments and slowed their polymerization rate; furthermore, increased Profilin levels also led to reduced individual cell velocity and directionality.

  1. A clinico-radiographic analysis of sagittal condylar guidance determined by protrusive interocclusal registration and panoramic radiographic images in humans

    OpenAIRE

    D Krishna Prasad; Namrata Shah; Chethan Hegde

    2012-01-01

    Purpose: To evaluate the correlation between sagittal condylar guidance obtained by protrusive interocclusal records and panoramic radiograph tracing methods in human dentulous subjects. Materials and Methods: The sagittal condylar guidance was determined in 75 dentulous subjects by protrusive interocclusal records using Aluwax through a face bow transfer (HANAU™ Spring Bow, Whip Mix Corporation, USA) to a semi-adjustable articulator (HANAU™ Wide-Vue Articulator, Whip Mix Corporation, USA). I...

  2. Heat transfer and friction factor characteristics of rectangular channel solar air heater duct having protrusions as roughness element

    OpenAIRE

    Maneesh Kaushal, Varun

    2012-01-01

    An experimental investigation has been carried out to see the effect of roughness element on heat transfer and friction factor on the absorber plate of the solar air heater. The roughness provided is in the form of protrusions which are arranged in an arc pattern. This paper presents an investigation to study the effect of protruded geometry on heat transfer coefficient and friction factor in an artificially roughened solar air heater duct. The pair of protrusion geometry arc angle (α) of 45o...

  3. Cutting edge: TNFR-shedding by CD4+CD25+ regulatory T cells inhibits the induction of inflammatory mediators.

    NARCIS (Netherlands)

    Mierlo, G.J. van; Scherer, H.U.; Hameetman, M.; Morgan, M.E.; Flierman, R.; Huizinga, T.W.J.; Toes, R.E.

    2008-01-01

    CD4+CD25+ regulatory T (Treg) cells play an essential role in maintaining tolerance to self and nonself. In several models of T cell-mediated (auto) immunity, Treg cells exert protective effects by the inhibition of pathogenic T cell responses. In addition, Treg cells can modulate T cell-independent

  4. Three-dimensional evaluation of upper anterior alveolar bone dehiscence after incisor retraction and intrusion in adult patients with bimaxillary protrusion malocclusion

    Institute of Scientific and Technical Information of China (English)

    Qing-yuan GUO; Shi-jie ZHANG; Hong LIU; Chun-ling WANG; Fu-lan WEI; Tao LV; Na-na WANG; Dong-xu LIU

    2011-01-01

    Objective: The purpose of this study was to evaluate three-dimensional (3D) dehiscence of upper anterior alveolar bone during incisor retraction and intrusion in adult patients with maximum anchorage.Methods: Twenty adult patients with bimaxillary dentoalveolar protrusion had the four first premolars extracted.Miniscrews were placed to provide maximum anchorage for upper incisor retraction and intrusion.A computed tomography (CT) scan was performed after placement of the miniscrews and treatment.The 3D reconstructions of pre- and post-CT data were used to assess the dehiscence of upper anterior alveolar bone.Results: The amounts of upper incisor retraction at the edge and apex were (7.64±1.68) and (3.91±2.10) mm,respectively,and (1.34±0.74) mm of upper central incisor intrusion.Upper alveolar bone height losses at labial alveolar ridge crest (LAC) and palatal alveolar ridge crest (PAC) were 0.543 and 2.612 mm,respectively,and the percentages were (6.49±3.54)% and (27.42±9.77)%,respectively.The shape deformations of LAC-labial cortex bending point (LBP) and PAC-palatal cortex bending point (PBP) were (15.37±5.20)° and (6.43±3.27)°,respectively.Conclusions: Thus,for adult patients with bimaxillary protrusion,mechanobiological response of anterior alveolus should be taken into account during incisor retraction and intrusion.Pursuit of maximum anchorage might lead to upper anterior alveolar bone loss.

  5. Cytosolic pressure provides a propulsive force comparable to actin polymerization during lamellipod protrusion

    Science.gov (United States)

    Manoussaki, Daphne; Shin, William D.; Waterman, Clare M.; Chadwick, Richard S.

    2015-07-01

    Does cytosolic pressure facilitate f-actin polymerization to push the leading edge of a cell forward during self-propelled motion? AFM force-distance (f-d) curves obtained from lamellipodia of live cells often exhibit a signal from which the tension, bending modulus, elastic modulus and thickness in the membrane-cortex complex can be estimated close to the contact point. These measurements permit an estimate of the cytosolic pressure via the canonical Laplace force balance. The deeper portion of the f-d curve allows estimation of the bulk modulus of the cytoskeleton after removal of the bottom effect artifact. These estimates of tension, pressure, cortex thickness and elastic moduli imply that cytosolic pressure both pushes the membrane forward and compresses the actin cortex rearward to facilitate f-actin polymerization. We also estimate that cytosolic pressure fluctuations, most likely induced by myosin, provide a propulsive force comparable to that provided by f-actin polymerization in a lamellipod.

  6. Analysis of the nitrogen K-edge x-ray absorption spectra of Zn-porphyrin/C{sub 70}-fulleren complex for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Suchkova, S A; Soldatov, A [Southern Federal University, Sorge str. 5, 344090 Rostov-on-Don (Russian Federation); Cudia, C Castellarin, E-mail: suchkova_sv@inbox.r [Sincrotrone Trieste S.C.p.A, s.s. 14 km 163.5 in Area Science Park, 34012 Trieste (Italy)

    2009-11-15

    The atomic structure models of Zn-porphyrin/C{sub 70} multilayer for solar cells were examined. The local atomic structure of the Zn-porphyrin/C{sub 70} complex was refined with the use of previously published results [1]. Since near-edge spectral region (XANES) is sensitive to the three-dimensional atomic geometry, the theoretical analysis of the experimental XANES was performed on the basis of finite difference method (FDMnes 2008 program code). Some electronic properties of the complex were obtained from the DFT calculations performed by means of Amsterdam Density Functional program package.

  7. Protrusion-guided extracellular vesicles mediate CD30 trans-signalling in the microenvironment of Hodgkin's lymphoma.

    Science.gov (United States)

    Hansen, Hinrich P; Engels, Hanna-Mareike; Dams, Maria; Paes Leme, Adriana F; Pauletti, Bianca Alves; Simhadri, Vijaya Lakshmi; Dürkop, Horst; Reiners, Katrin S; Barnert, Sabine; Engert, Andreas; Schubert, Rolf; Quondamatteo, Fabio; Hallek, Michael; Pogge von Strandmann, Elke

    2014-03-01

    Classical Hodgkin's lymphoma (cHL)-affected lymphoid tissue contains only a few malignant Hodgkin and Reed-Sternberg (HRS) cells, which are disseminated within a massive infiltrate of reactive cells. In particular, the innate immune infiltrate is deemed to support tumour growth by direct cell-cell interaction. Since they are rarely found in close proximity to the malignant cells in situ, we investigated whether cHL-derived extracellular vesicles might substitute for a direct cell-cell contact. We studied the crosstalk of the transmembrane proteins CD30 and CD30 ligand (CD30L) because they are selectively expressed on HRS and innate immune cells, respectively. Here, we showed that HRS cells released both the ectodomain as a soluble molecule (sCD30) and the entire receptor on the surface of extracellular vesicles. The vesicle diameter was 40-800 nm, as determined by cryo- and immune electron microscopy. In addition to CD30, typical extracellular vesicle markers were detected by mass spectrometry and flow cytometry, including tetraspanins, flotillins, heat shock proteins and adhesion molecules. In contrast to sCD30, vesicles caused a CD30-dependent release of interleukin-8 in CD30L(+) eosinophil-like EoL-1 cells and primary granulocytes from healthy donors, underscoring the functionality of CD30 on vesicles. In extracellular matrix (ECM)-embedded culture of HRS cells, a network of actin and tubulin-based protrusions guided CD30(+) vesicles into the micro-environment. This network targeted CD30(+) vesicles towards distant immune cells and caused a robust polarization of CD30L. Confocal laser scanning microscopy of 30 µm sections showed a CD30 vesicle-containing network also in cHL-affected lymphoid tissue of both mixed-cellularity and nodular sclerosing subtypes. This network might facilitate the communication between distant cell types in cHL tissue and allow a functional CD30-CD30L interaction in trans. The tubulin backbone of the network may provide a target for

  8. Formation of chloroplast protrusions and catalase activity in alpine Ranunculus glacialis under elevated temperature and different CO2/O2 ratios.

    Science.gov (United States)

    Buchner, Othmar; Moser, Tim; Karadar, Matthias; Roach, Thomas; Kranner, Ilse; Holzinger, Andreas

    2015-11-01

    Chloroplast protrusions (CPs) have frequently been observed in plants, but their significance to plant metabolism remains largely unknown. We investigated in the alpine plant Ranunculus glacialis L. treated under various CO2 concentrations if CP formation is related to photorespiration, specifically focusing on hydrogen peroxide (H2O2) metabolism. Immediately after exposure to different CO2 concentrations, the formation of CPs in leaf mesophyll cells was assessed and correlated to catalase (CAT) and ascorbate peroxidase (APX) activities. Under natural irradiation, the relative proportion of chloroplasts with protrusions (rCP) was highest (58.7 %) after exposure to low CO2 (38 ppm) and was lowest (3.0 %) at high CO2 (10,000 ppm). The same relationship was found for CAT activity, which decreased from 34.7 nkat mg(-1) DW under low CO2 to 18.4 nkat mg(-1) DW under high CO2, while APX activity did not change significantly. When exposed to natural CO2 concentration (380 ppm) in darkness, CP formation was significantly lower (18.2 %) compared to natural solar irradiation (41.3 %). In summary, CP formation and CAT activity are significantly increased under conditions that favour photorespiration, while in darkness or at high CO2 concentration under light, CP formation is significantly lower, providing evidence for an association between CPs and photorespiration. PMID:25701381

  9. Case of Severe Maxillary Protrusion Accompanied by Crowding and Scissor Bite.

    Science.gov (United States)

    Katada, Hidenori; Sueishi, Kenji

    2015-01-01

    This case involved a 30-year-old woman who visited our hospital with the main complaint of protrusion of the maxillary incisors and upper and lower lips. She had difficulty closing her lips, and a chin button was observed when the lips were closed. The skeletal pattern showed maxillary protrusion and mandibular retrusion, and the mandible showed severe high angle. Labial inclination of both the maxillary and mandibular incisors was found, as well as crowding. In addition, the maxillary left second molar showed buccal displacement, and scissor bite was evident in the left second molar region. The bilateral molar relationship was cusp-to-cusp class II malocclusion. Angle class II maxillary protrusion accompanied by crowding and left second molar scissor bite was diagnosed. Surgical orthodontic treatment was judged as the best approach to treat the jaw deformities. However, in line with the wishes of the patient, treatment was undertaken using implant anchors instead. Straight-wire brackets with a 0.022-inch slot were fitted. A lingual arch was placed in the mandible and plate-type implant anchors in the first molar region of the maxilla. Almost no change was observed in skeletal pattern as no surgery was performed. The maxillary incisors moved back 10 mm, however, and the mandibular incisors showed an improvement of 4 mm from L1 to APo. The upper and lower lips consequently moved back 7 mm with respect to the E-line. Active treatment required 3 years and 6 months. Esthetic and functional improvements were achieved. PMID:26657523

  10. Clinical Experience on Treatment of Lumbar Intervertebral Disc Protrusion by Traditional Manual Techniques plus Electric Acupuncture

    Institute of Scientific and Technical Information of China (English)

    LIANG Hao-wen; WU Fang; YANG Wan-zhang; ZHANG Min; HUANG Guo-qi

    2007-01-01

    52 cases of the patients with L4-S1 intervertebral disc protrusion were first treated by traditional Tuina manual techniques, including the rolling method, pressing method,oblique-plucking method and shaking method, and then treated by electric acupuncture on Shenshu (BL 23), Yaoyangguan (GV 3), Dachangshu (BL 25), Xiaochangshu (BL 27),Mingmen (GV 4) and Shangliao (BL 31). After 7-28 sessions of the treatments, the results showed cure in 40 cases, remarkable effect in 8 cases, effect in 3 cases, failure in 1 case, and the total effective rate in 98.1%.

  11. Vertebral stabilisation and selective decompression for the management of triple thoracolumbar disc protrusions.

    Science.gov (United States)

    McKee, W M; Downes, C J

    2008-10-01

    Triple adjacent thoracolumbar disc protrusions causing moderate to severe spinal cord compression were diagnosed by magnetic resonance imaging in two German shepherd dogs with marked paraparesis and pelvic limb ataxia. Both cases were managed by selective hemilaminectomy, partial annulectomy and bilateral quadruple vertebral body stabilisation using novel canine locking fixation plates (SOP). The stabilisation of multiple vertebrae in the thoracolumbar spine was possible because the plates could be contoured with six degrees of freedom. Spinal pain resolved and neurological function improved in both dogs. Screw breakage was evident in one dog five months following surgery. PMID:18631222

  12. 外侧膝状体细胞对边缘的响应模型%Response of Lateral Geniculate Nucleus Cells to Edges

    Institute of Scientific and Technical Information of China (English)

    任远

    2014-01-01

    Edges composing of stimuli of different intensities are common in both natural scenes and digital images.Edge detection is a basic step for machine visual systems,particularly machine biological visual systems.This paper establishes a model of lateral geniculate nucleus (LGN)cells in a primary visual pathway,describes the LGN cell response to edges,and provides feature representations for designing image processing approaches based on neural mechanism. According to physiological characteristics of retinal ganglion cells,the paper uses the classical model of difference of Gaussians to describe the LGN cell response to stimuli,and obtains a re-sponse function via reasonable simplifications.Through simple analyses,several mathematical properties of the response function are obtained,which agree with the physiological characteristics of neurons.By further simplifying the contrast of a stimulus,a normalized response function is obtained.Numeric experiments show that similarities exist between the function’s response curve and the physiological curve discovered in a previous neural science research,showing validity of the described model.%边缘检测是机器视觉系统与生物视觉系统处理视觉信息的基础阶段。为初级视觉通路中的外侧膝状体(LGN)细胞建立一个模型,描述其对边缘的响应,为构建基于神经机制的图像处理方法提供特征表征。根据神经节细胞感受野的生理特性,用经典的高斯差模型描述 LGN 细胞对刺激的响应,通过合理地简化得到相对简单的响应函数。通过简单数学分析,能够得到函数的几点数学性质,且这些性质都与神经元的生理特性相符。进一步简化刺激的对比度,得到归一化的响应函数。数值实验发现,函数的响应曲线和神经科学研究得到的生理曲线具有相似性,说明该数学模型的合理性。

  13. Cutting Edge: Distinct Glycolytic and Lipid Oxidative Metabolic Programs Are Essential for Effector and Regulatory CD4+ T Cell Subsets

    OpenAIRE

    Ryan D Michalek; Gerriets, Valerie A.; Jacobs, Sarah R.; Macintyre, Andrew N.; MacIver, Nancie J.; Mason, Emily F.; Sullivan, Sarah A.; Nichols, Amanda G.; Rathmell, Jeffrey C.

    2011-01-01

    Stimulated CD4+ T lymphocytes can differentiate into effector T cell (Teff) or inducible regulatory T cell (Treg) subsets with specific immunological roles. We show that Teff and Treg require distinct metabolic programs to support these functions. Th1, Th2, and Th17 cells expressed high surface levels of the glucose transporter Glut1 and were highly glycolytic. Treg, in contrast, expressed low levels of Glut1 and had high lipid oxidation rates. Consistent with glycolysis and lipid oxidation p...

  14. Forest edge development

    OpenAIRE

    Wiström, Björn

    2015-01-01

    This thesis investigates design guidelines and management systems for the development of stationary forest edges with a graded profile in infrastructure and urban environments. The spatial restriction for the edge to move forward caused by human land use counteracts the natural dynamics and development patterns of graded forest edges. However graded forest edges with successively increasing height from the periphery to the interior of the forest edge are often seen as ideal as they supports ...

  15. Cutting Edge: MicroRNA-223 Regulates Myeloid Dendritic Cell-Driven Th17 Responses in Experimental Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Ifergan, Igal; Chen, Siqi; Zhang, Bin; Miller, Stephen D

    2016-02-15

    Myeloid cells play a crucial role in the induction and sustained inflammation in neuroinflammatory disorders, such as multiple sclerosis. miR-223, a myeloid cell-specific microRNA, is one of the most upregulated microRNAs in multiple sclerosis patients. We demonstrate that miR-223-knockout mice display significantly reduced active and adoptive-transfer experimental autoimmune encephalomyelitis that is characterized by reduced numbers of myeloid dendritic cells (mDCs) and Th17 cells in the CNS. Knockout mDCs have increased PD-L1 and decreased IL-1β, IL-6, and IL-23 expression, as well as a reduced capacity to drive Th17, but not Th1, cell differentiation. Thus, miR-223 controls mDC-induced activation of pathologic Th17 responses during autoimmune inflammation. PMID:26783338

  16. Micro-abrasion package capture cell experiment on the trailing edge of LDEF: Impactor chemistry and whipple bumper shield efficiencies

    Science.gov (United States)

    Fitzgerald, Howard J.; Yano, Hajime

    1995-01-01

    Four of the eight available double layer microparticle capture cells, flown as the experiment A0023 on the trailing (West) face of LDEF, have been extensively studied. An investigation of the chemistry of impactors has been made using SEM/EDX techniques and the effectiveness of the capture cells as bumper shields has also been examined. Studies of these capture cells gave positive EDX results, with 53 percent of impact sites indicating the presence of some chemical residues, the predominant residue identified as being silicon in varying quantities.

  17. Methods of Cell Propulsion through the Local Stroma in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Kerry J. Davies

    2014-01-01

    Full Text Available In the normal breast, cellular structures change cyclically in response to ovarian hormones. Cell proliferation, apoptosis, invasion, and differentiation are integral processes that are precisely regulated. Normal epithelial cells depend on the formation of intercellular adhesion contacts to form a continuous sheet of stratifying cell layers that are attached to one and other horizontally and vertically. Cells migrate by extending membrane protrusions to explore the extracellular space locating their targets in a chemotactic manner. The formation of cell protrusions is driven by the assembly of actin filaments at the leading edge. Reorganisation is regulated by a highly integrated signalling cascade that transduces extracellular stimuli to the actin filaments. This signalling cascade is governed by GTPases which act as molecular switches leading to actin polymerisation and the formation of filopodia and lamellipodia. This process is linked to downstream molecules known collectively as WASP proteins, which, in the presence of cortactin, form a complex leading to nucleation and formation of branched filaments. In breast cancer, the cortactin is over expressed leading to increased cellular motility and invasiveness. This hugely complex and integrated signalling cascade transduces extracellular stimuli. There are multiple genes related to cell motility which are dysregulated in human breast cancers.

  18. The edges of graphene

    Science.gov (United States)

    Zhang, Xiuyun; Xin, John; Ding, Feng

    2013-03-01

    The edge of two dimensional (2D) graphene, as the surface of a three dimensional (3D) crystal, plays a crucial role in the determination of its physical, electronic and chemical properties and thus has been extensively studied recently. In this review, we summarize the recent advances in the study of graphene edges, including edge formation energy, edge reconstruction, method of graphene edge synthesis and the recent progress on metal-passivated graphene edges and the role of edges in graphene CVD growth. We expect this review to provide a guideline for readers to gain a clear picture of graphene edges from several aspects, especially the catalyst-passivated graphene edges and their role in graphene CVD growth.

  19. The edges of graphene.

    Science.gov (United States)

    Zhang, Xiuyun; Xin, John; Ding, Feng

    2013-04-01

    The edge of two dimensional (2D) graphene, as the surface of a three dimensional (3D) crystal, plays a crucial role in the determination of its physical, electronic and chemical properties and thus has been extensively studied recently. In this review, we summarize the recent advances in the study of graphene edges, including edge formation energy, edge reconstruction, method of graphene edge synthesis and the recent progress on metal-passivated graphene edges and the role of edges in graphene CVD growth. We expect this review to provide a guideline for readers to gain a clear picture of graphene edges from several aspects, especially the catalyst-passivated graphene edges and their role in graphene CVD growth. PMID:23420074

  20. Cutting Edge: B Cell-Intrinsic T-bet Expression Is Required To Control Chronic Viral Infection.

    Science.gov (United States)

    Barnett, Burton E; Staupe, Ryan P; Odorizzi, Pamela M; Palko, Olesya; Tomov, Vesselin T; Mahan, Alison E; Gunn, Bronwyn; Chen, Diana; Paley, Michael A; Alter, Galit; Reiner, Steven L; Lauer, Georg M; Teijaro, John R; Wherry, E John

    2016-08-15

    The role of Ab and B cells in preventing infection is established. In contrast, the role of B cell responses in containing chronic infections remains poorly understood. IgG2a (IgG1 in humans) can prevent acute infections, and T-bet promotes IgG2a isotype switching. However, whether IgG2a and B cell-expressed T-bet influence the host-pathogen balance during persisting infections is unclear. We demonstrate that B cell-specific loss of T-bet prevents control of persisting viral infection. T-bet in B cells controlled IgG2a production, as well as mucosal localization, proliferation, glycosylation, and a broad transcriptional program. T-bet controlled a broad antiviral program in addition to IgG2a because T-bet in B cells was important, even in the presence of virus-specific IgG2a. Our data support a model in which T-bet is a universal controller of antiviral immunity across multiple immune lineages. PMID:27430722

  1. Tropomyosin Promotes Lamellipodial Persistence by Collaborating with Arp2/3 at the Leading Edge.

    Science.gov (United States)

    Brayford, Simon; Bryce, Nicole S; Schevzov, Galina; Haynes, Elizabeth M; Bear, James E; Hardeman, Edna C; Gunning, Peter W

    2016-05-23

    At the leading edge of migrating cells, protrusion of the lamellipodium is driven by Arp2/3-mediated polymerization of actin filaments [1]. This dense, branched actin network is promoted and stabilized by cortactin [2, 3]. In order to drive filament turnover, Arp2/3 networks are remodeled by proteins such as GMF, which blocks the actin-Arp2/3 interaction [4, 5], and coronin 1B, which acts by directing SSH1L to the lamellipodium where it activates the actin-severing protein cofilin [6, 7]. It has been shown in vitro that cofilin-mediated severing of Arp2/3 actin networks results in the generation of new pointed ends to which the actin-stabilizing protein tropomyosin (Tpm) can bind [8]. The presence of Tpm in lamellipodia, however, is disputed in the literature [9-19]. Here, we report that the Tpm isoforms 1.8/9 are enriched in the lamellipodium of fibroblasts as detected with a novel isoform-specific monoclonal antibody. RNAi-mediated silencing of Tpm1.8/9 led to an increase of Arp2/3 accumulation at the cell periphery and a decrease in the persistence of lamellipodia and cell motility, a phenotype consistent with cortactin- and coronin 1B-deficient cells [2, 7]. In the absence of coronin 1B or cofilin, Tpm1.8/9 protein levels are reduced while, conversely, inhibition of Arp2/3 with CK666 leads to an increase in Tpm1.8/9 protein. These findings establish a novel regulatory mechanism within the lamellipodium whereby Tpm collaborates with Arp2/3 to promote lamellipodial-based cell migration. PMID:27112294

  2. Composition analysis of a polymer electrolyte membrane fuel cell microporous layer using scanning transmission X-ray microscopy and near edge X-ray absorption fine structure analysis

    Science.gov (United States)

    George, Michael G.; Wang, Jian; Banerjee, Rupak; Bazylak, Aimy

    2016-03-01

    The novel application of scanning transmission X-ray microscopy (STXM) to the microporous layer (MPL) of a polymer electrolyte membrane fuel cell is investigated. A spatially resolved chemical component distribution map is obtained for the MPL of a commercially available SGL 25 BC sample. This is achieved with near edge X-ray absorption fine structure spectroscopic analysis. Prior to analysis the sample is embedded in non-reactive epoxy and ultra-microtomed to a thickness of 100 nm. Polytetrafluoroethylene (PTFE), carbon particle agglomerates, and supporting epoxy resin distributions are identified and reconstructed for a scanning area of 6 μm × 6 μm. It is observed that the spatial distribution of PTFE is strongly correlated to the carbon particle agglomerations. Additionally, agglomerate structures of PTFE are identified, possibly indicating the presence of a unique mesostructure in the MPL. STXM analysis is presented as a useful technique for the investigation of chemical species distributions in the MPL.

  3. High-surface-area nanomesh graphene with enriched edge sites as efficient metal-free cathodes for dye-sensitized solar cells.

    Science.gov (United States)

    Yang, Wang; Xu, Xiuwen; Gao, Yalun; Li, Zhao; Li, Cuiyu; Wang, Wenping; Chen, Yu; Ning, Guoqing; Zhang, Liqiang; Yang, Fan; Chen, Shengli; Wang, Aijun; Kong, Jing; Li, Yongfeng

    2016-07-14

    Exploiting cost-effective and highly efficient counter electrodes (CEs) has been a persistent objective for practical application of dye-sensitized solar cells (DSSCs). Here, we present an efficient CE by using pure three-dimensional (3D) nanomesh graphene frameworks (NGFs) which are synthesized via a template-directed chemical vapor deposition (CVD) approach. The high-surface-area 3D NGFs associated with the enriched surface edge defects make it very efficient towards I3(-) reduction even without any Pt catalyst. More interestingly, by virtue of the interpenetrating graphene frameworks, the NGFs exhibit excellent electron conductivity, thus leading to facile charge transfer. Consequently, the DSSCs with pure NGFs as CEs display a power conversion efficiency of 7.32%, which is comparable to that of Pt as CEs (7.28%), thereby exhibiting great potential as low-cost and highly efficient CE materials for large-scale deployment of DSSCs. PMID:27328165

  4. Successful treatment of Class II malocclusion with bidental protrusion using standard edgewise prescription

    Directory of Open Access Journals (Sweden)

    Mohd Ayaz

    2016-01-01

    Full Text Available This case report deals with the successful orthodontic treatment of a 14-year-old female patient having Class II malocclusion with bidental protrusion using standard edgewise prescription. She reported with forwardly placed upper front teeth and difficulty in closing lips. She had prognathic maxilla, retrognathic mandible, and full cusp Class II molar and canine relation bilaterally with overjet of 7 mm. She was in cervical vertebrae maturation indicator Stage IV. The case was treated by fixed extraction mechanotherapy. Interarch Class II mechanics was used to retract the upper incisor and to mesialize the lower molars. Simultaneously, Class I mechanics was used to upright lower incisors. Tip back bend, curve of Spee, and extra palatal root torque were incorporated in upper archwire to maintain molars in upright position and prevent extrusion and deepening of bite, respectively. There was satisfactory improvement in facial profile at the end of 24 months. After a follow-up of 6 months, occlusion was stable.

  5. Uncoupling and reactive oxygen species (ROS)--a double-edged sword for β-cell function? "Moderation in all things".

    Science.gov (United States)

    Collins, Sheila; Pi, Jingbo; Yehuda-Shnaidman, Einav

    2012-12-01

    The ability of the mitochondrion to (a) manage fuel import to oxidize for adenosine tri-phosphate (ATP) generation while (b) protecting itself and the cellular environment from electron leak, which can generate highly reactive oxygen species (ROS) is a delicate balancing act. ATP is the currency of the cell and as such serves a signaling function as a substrate partner to many kinases and ion channels. While various ROS species have been viewed as a dangerous and toxic group of molecules, it also has a role as a signal derived from mitochondria, as well as other enzymatic sources: a double-edged sword. Current efforts to understand the biochemical mechanisms affected by ROS as a signal--usually noted to be hydrogen peroxide (H(2)O(2))--are exciting, but this duality of ROS effects also pose challenges in managing its levels to protect cells. The mitochondrial uncoupling protein-2 (UCP2), UCP3, and the permeability transition pore have been integral to efforts to try to understand what role mitochondrial-derived ROS have in cells. In this piece we reflect on mitochondrial ROS and uncoupling proteins as signaling regulators. It seems that when it comes to ROS and uncoupling the proverb "Moderation in all things" is apt. PMID:23168277

  6. Stability of edge states and edge magnetism in graphene nanoribbons

    OpenAIRE

    Kunstmann, Jens; Özdoğan, Cem; Quandt, Alexander; Fehske, Holger

    2010-01-01

    We critically discuss the stability of edge states and edge magnetism in zigzag edge graphene nanoribbons (ZGNRs). We point out that magnetic edge states might not exist in real systems, and show that there are at least three very natural mechanisms - edge reconstruction, edge passivation, and edge closure - which dramatically reduce the effect of edge states in ZGNRs or even totally eliminate them. Even if systems with magnetic edge states could be made, the intrinsic magnetism would not be ...

  7. CLINICAL AND MAGNETIC RESONANCE IMAGING CHARACTERISTICS OF THORACOLUMBAR INTERVERTEBRAL DISK EXTRUSIONS AND PROTRUSIONS IN LARGE BREED DOGS.

    Science.gov (United States)

    Gomes, Sergio A; Volk, Holger A; Packer, Rowena Ma; Kenny, Patrick J; Beltran, Elsa; De Decker, Steven

    2016-07-01

    Treatment recommendations differ for dogs with intervertebral disk extrusion vs. intervertebral disk protrusion. The aim of this retrospective, cross-sectional study was to determine whether clinical and magnetic resonance imaging (MRI) variables could be used to predict a diagnosis of thoracolumbar intervertebral disk extrusion or protrusion in dogs. Dogs were included if they were large breed dogs, had an MRI study of the thoracolumbar or lumbar vertebral column, had undergone spinal surgery, and had the type of intervertebral disk herniation (intervertebral disk extrusion or protrusion) clearly stated in surgical reports. A veterinary neurologist unaware of surgical findings reviewed MRI studies and recorded number, location, degree of degeneration and morphology of intervertebral disks, presence of nuclear clefts, disk space narrowing, extent, localization and lateralization of herniated disk material, degree of spinal cord compression, intraparenchymal intensity changes, spondylosis deformans, spinal cord swelling, spinal cord atrophy, vertebral endplate changes, and presence of extradural hemorrhage. Ninety-five dogs were included in the sample. Multivariable statistical models indicated that longer duration of clinical signs (P = 0.01), midline instead of lateralized disk herniation (P = 0.007), and partial instead of complete disk degeneration (P = 0.01) were associated with a diagnosis of intervertebral disk protrusion. The presence of a single intervertebral herniation (P = 0.023) and dispersed intervertebral disk material not confined to the disk space (P = 0.06) made a diagnosis of intervertebral disk extrusion more likely. Findings from this study identified one clinical and four MRI variables that could potentially facilitate differentiating intervertebral disk extrusions from protrusions in dogs. PMID:27038182

  8. Percutaneous medical ozone injection under low-dose CT guidance for the treatment of lumbar intervertebral disc protrusion

    International Nuclear Information System (INIS)

    Objective: To evaluate the therapeutic effect of percutaneous medical ozone injection in treating lumbar intervertebral disc protrusion under low-dose CT scanning guidance. Methods: Under low-dose CT scanning guidance, percutaneous injection of different concentrations of medical ozone was carried out in 156 patients with lumbar intervertebral disc protrusion. The puncturing was performed through the latero-posterior route or medical route of vertebral facets, which was followed by the injection of medical ozone into, or around, the intervertebral disk. Results: Of the total 156 patients, excellent and good result at one week after the treatment was obtained in 59 and 63 respectively, with an effective rate of 78.2%. One month after the procedure, the excellent and good result was achieved in 63 and 64 respectively, with an effective rate of 81.4%. Three months after the injection the total effective rate was 86%. The effective rate for disc bulging, protrusion and prolapse was 97.4% (37/38), 90.2% (101/112) and 3/6, respectively. The effective rate in the group that kept ozone within the intervertebral disk and in the group that did not keep ozone within the intervertebral disk was 92.0% (46/50) and 87.3% (69/79) respectively. The effective rate in the group with complete annulus fibrous and in the group with ruptured annulus fibrous was 92.2% (119/129) and 81.5% (22/27) respectively. Conclusion: For the treatment of lumbar intervertebral disc protrusion percutaneous medical ozone injection under low-dose CT scanning guidance carries reliable therapeutic efficacy. Having the advantages of high safety, less invasiveness, precisely locating ability, simple manipulation and lower radiation exposure dose, this technique is an ideal treatment for lumbar intervertebral disc protrusion. (authors)

  9. Novel roles of formin mDia2 in lamellipodia and filopodia formation in motile cells.

    Directory of Open Access Journals (Sweden)

    Changsong Yang

    2007-11-01

    Full Text Available Actin polymerization-driven protrusion of the leading edge is a key element of cell motility. The important actin nucleators formins and the Arp2/3 complex are believed to have nonoverlapping functions in inducing actin filament bundles in filopodia and dendritic networks in lamellipodia, respectively. We tested this idea by investigating the role of mDia2 formin in leading-edge protrusion by loss-of-function and gain-of-function approaches. Unexpectedly, mDia2 depletion by short interfering RNA (siRNA severely inhibited lamellipodia. Structural analysis of the actin network in the few remaining lamellipodia suggested an mDia2 role in generation of long filaments. Consistently, constitutively active mDia2 (DeltaGBD-mDia2 induced accumulation of long actin filaments in lamellipodia and increased persistence of lamellipodial protrusion. Depletion of mDia2 also inhibited filopodia, whereas expression of DeltaGBD-mDia2 promoted their formation. Correlative light and electron microscopy showed that DeltaGBD-mDia2-induced filopodia were formed from lamellipodial network through gradual convergence of long lamellipodial filaments into bundles. Efficient filopodia induction required mDia2 targeting to the membrane, likely through a scaffolding protein Abi1. Furthermore, mDia2 and Abi1 interacted through the N-terminal regulatory sequences of mDia2 and the SH3-containing Abi1 sequences. We propose that mDia2 plays an important role in formation of lamellipodia by nucleating and/or protecting from capping lamellipodial actin filaments, which subsequently exhibit high tendency to converge into filopodia.

  10. Edge-selenated graphene nanoplatelets as durable metal-free catalysts for iodine reduction reaction in dye-sensitized solar cells

    Science.gov (United States)

    Ju, Myung Jong; Jeon, In-Yup; Kim, Hong Mo; Choi, Ji Il; Jung, Sun-Min; Seo, Jeong-Min; Choi, In Taek; Kang, Sung Ho; Kim, Han Seul; Noh, Min Jong; Lee, Jae-Joon; Jeong, Hu Young; Kim, Hwan Kyu; Kim, Yong-Hoon; Baek, Jong-Beom

    2016-01-01

    Metal-free carbon-based electrocatalysts for dye-sensitized solar cells (DSSCs) are sufficiently active in Co(II)/Co(III) electrolytes but are not satisfactory in the most commonly used iodide/triiodide (I−/I3−) electrolytes. Thus, developing active and stable metal-free electrocatalysts in both electrolytes is one of the most important issues in DSSC research. We report the synthesis of edge-selenated graphene nanoplatelets (SeGnPs) prepared by a simple mechanochemical reaction between graphite and selenium (Se) powders, and their application to the counter electrode (CE) for DSSCs in both I−/I3− and Co(II)/Co(III) electrolytes. The edge-selective doping and the preservation of the pristine graphene basal plane in the SeGnPs were confirmed by various analytical techniques, including atomic-resolution transmission electron microscopy. Tested as the DSSC CE in both Co(bpy)32+/3+ (bpy = 2,2′-bipyridine) and I−/I3− electrolytes, the SeGnP-CEs exhibited outstanding electrocatalytic performance with ultimately high stability. The SeGnP-CE–based DSSCs displayed a higher photovoltaic performance than did the Pt-CE–based DSSCs in both SM315 sensitizer with Co(bpy)32+/3+ and N719 sensitizer with I−/I3− electrolytes. Furthermore, the I3− reduction mechanism, which has not been fully understood in carbon-based CE materials to date, was clarified by an electrochemical kinetics study combined with density functional theory and nonequilibrium Green’s function calculations. PMID:27386557

  11. Lipid tail protrusions mediate the insertion of nanoparticles into model cell membranes

    OpenAIRE

    Van Lehn, Reid C.; Ricci, Maria; Silva, Paulo H.J.; Andreozzi, Patrizia; Reguera, Javier; Voïtchovsky, Kislon; Stellacci, Francesco; Alexander-Katz, Alfredo

    2013-01-01

    Recent work has demonstrated that charged ​gold nanoparticles (AuNPs) protected by an amphiphilic organic monolayer can spontaneously insert into the core of lipid bilayers to minimize the exposure of hydrophobic surface area to water. However, the kinetic pathway to reach the thermodynamically stable transmembrane configuration is unknown. Here, we use unbiased atomistic simulations to show the pathway by which AuNPs spontaneously insert into bilayers and confirm the results experimentally o...

  12. Lipid tail protrusions mediate the insertion of nanoparticles into model cell membranes.

    OpenAIRE

    Van Lehn, R. C.; Ricci, M; Silva, P. H. J.; Andreozzi, P.; Reguera, J; Voïtchovsky, K.; Stellacci, F.; Alexander-Katz, A.

    2014-01-01

    Recent work has demonstrated that charged ​gold nanoparticles (AuNPs) protected by an amphiphilic organic monolayer can spontaneously insert into the core of lipid bilayers to minimize the exposure of hydrophobic surface area to water. However, the kinetic pathway to reach the thermodynamically stable transmembrane configuration is unknown. Here, we use unbiased atomistic simulations to show the pathway by which AuNPs spontaneously insert into bilayers and confirm the results experimentally o...

  13. High-surface-area nanomesh graphene with enriched edge sites as efficient metal-free cathodes for dye-sensitized solar cells

    Science.gov (United States)

    Yang, Wang; Xu, Xiuwen; Gao, Yalun; Li, Zhao; Li, Cuiyu; Wang, Wenping; Chen, Yu; Ning, Guoqing; Zhang, Liqiang; Yang, Fan; Chen, Shengli; Wang, Aijun; Kong, Jing; Li, Yongfeng

    2016-06-01

    Exploiting cost-effective and highly efficient counter electrodes (CEs) has been a persistent objective for practical application of dye-sensitized solar cells (DSSCs). Here, we present an efficient CE by using pure three-dimensional (3D) nanomesh graphene frameworks (NGFs) which are synthesized via a template-directed chemical vapor deposition (CVD) approach. The high-surface-area 3D NGFs associated with the enriched surface edge defects make it very efficient towards I3- reduction even without any Pt catalyst. More interestingly, by virtue of the interpenetrating graphene frameworks, the NGFs exhibit excellent electron conductivity, thus leading to facile charge transfer. Consequently, the DSSCs with pure NGFs as CEs display a power conversion efficiency of 7.32%, which is comparable to that of Pt as CEs (7.28%), thereby exhibiting great potential as low-cost and highly efficient CE materials for large-scale deployment of DSSCs.Exploiting cost-effective and highly efficient counter electrodes (CEs) has been a persistent objective for practical application of dye-sensitized solar cells (DSSCs). Here, we present an efficient CE by using pure three-dimensional (3D) nanomesh graphene frameworks (NGFs) which are synthesized via a template-directed chemical vapor deposition (CVD) approach. The high-surface-area 3D NGFs associated with the enriched surface edge defects make it very efficient towards I3- reduction even without any Pt catalyst. More interestingly, by virtue of the interpenetrating graphene frameworks, the NGFs exhibit excellent electron conductivity, thus leading to facile charge transfer. Consequently, the DSSCs with pure NGFs as CEs display a power conversion efficiency of 7.32%, which is comparable to that of Pt as CEs (7.28%), thereby exhibiting great potential as low-cost and highly efficient CE materials for large-scale deployment of DSSCs. Electronic supplementary information (ESI) available: Additional SEM image, SAED image, cross-sectional SEM

  14. Plasmonic gratings with nano-protrusions made by glancing angle deposition for single-molecule super-resolution imaging

    Science.gov (United States)

    Chen, B.; Wood, A.; Pathak, A.; Mathai, J.; Bok, S.; Zheng, H.; Hamm, S.; Basuray, S.; Grant, S.; Gangopadhyay, K.; Cornish, P. V.; Gangopadhyay, S.

    2016-06-01

    Super-resolution imaging has been advantageous in studying biological and chemical systems, but the required equipment and platforms are expensive and unable to observe single-molecules at the high (μM) fluorophore concentrations required to study protein interaction and enzymatic activity. Here, a plasmonic platform was designed that utilized an inexpensively fabricated plasmonic grating in combination with a scalable glancing angle deposition (GLAD) technique using physical vapor deposition. The GLAD creates an abundance of plasmonic nano-protrusion probes that combine the surface plasmon resonance (SPR) from the periodic gratings with the localized SPR of these nano-protrusions. The resulting platform enables simultaneous imaging of a large area without point-by-point scanning or bulk averaging for the detection of single Cyanine-5 molecules in dye concentrations ranging from 50 pM to 10 μM using epifluorescence microscopy. Combining the near-field plasmonic nano-protrusion probes and super-resolution technique using localization microscopy, we demonstrate the ability to resolve grain sizes down to 65 nm. This plasmonic GLAD grating is a cost-effective super-resolution imaging substrate with potential applications in high-speed biomedical imaging over a wide range of fluorescent concentrations.Super-resolution imaging has been advantageous in studying biological and chemical systems, but the required equipment and platforms are expensive and unable to observe single-molecules at the high (μM) fluorophore concentrations required to study protein interaction and enzymatic activity. Here, a plasmonic platform was designed that utilized an inexpensively fabricated plasmonic grating in combination with a scalable glancing angle deposition (GLAD) technique using physical vapor deposition. The GLAD creates an abundance of plasmonic nano-protrusion probes that combine the surface plasmon resonance (SPR) from the periodic gratings with the localized SPR of these nano-protrusions

  15. Unreacted PbI2 as a Double-Edged Sword for Enhancing the Performance of Perovskite Solar Cells.

    Science.gov (United States)

    Jacobsson, T Jesper; Correa-Baena, Juan-Pablo; Halvani Anaraki, Elham; Philippe, Bertrand; Stranks, Samuel D; Bouduban, Marine E F; Tress, Wolfgang; Schenk, Kurt; Teuscher, Joël; Moser, Jacques-E; Rensmo, Håkan; Hagfeldt, Anders

    2016-08-17

    Lead halide perovskites have over the past few years attracted considerable interest as photo absorbers in PV applications with record efficiencies now reaching 22%. It has recently been found that not only the composition but also the precise stoichiometry is important for the device performance. Recent reports have, for example, demonstrated small amount of PbI2 in the perovskite films to be beneficial for the overall performance of both the standard perovskite, CH3NH3PbI3, as well as for the mixed perovskites (CH3NH3)x(CH(NH2)2)(1-x)PbBryI(3-y). In this work a broad range of characterization techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photo electron spectroscopy (PES), transient absorption spectroscopy (TAS), UV-vis, electroluminescence (EL), photoluminescence (PL), and confocal PL mapping have been used to further understand the importance of remnant PbI2 in perovskite solar cells. Our best devices were over 18% efficient, and had in line with previous results a small amount of excess PbI2. For the PbI2-deficient samples, the photocurrent dropped, which could be attributed to accumulation of organic species at the grain boundaries, low charge carrier mobility, and decreased electron injection into the TiO2. The PbI2-deficient compositions did, however, also have advantages. The record Voc was as high as 1.20 V and was found in PbI2-deficient samples. This was correlated with high crystal quality, longer charge carrier lifetimes, and high PL yields and was rationalized as a consequence of the dynamics of the perovskite formation. We further found the ion migration to be obstructed in the PbI2-deficient samples, which decreased the JV hysteresis and increased the photostability. PbI2-deficient synthesis conditions can thus be used to deposit perovskites with excellent crystal quality but with the downside of grain boundaries enriched in organic species, which act as a barrier toward

  16. Edge physics Simulations

    Institute of Scientific and Technical Information of China (English)

    X.Q. Xu; C.S. Chang

    2007-01-01

    @@ The plasma edge includes the pedestal, scrape-off, and divertor regions. A complete edge physics should deal with the plasma, atomic, and the plasma-wall interaction phenomena. The edge provides the source of plasma through ionization of the incoming neutral particles and source of impurity through the wall sputtering. Edge plasma sets a boundary condition for the core confinement physics. Importance of the edge plasma has been elevated to the top list of the ITER physics research needs due to the necessity of the self-organized plasma pedestal and its destruction by edge localized mode activities. Extrapolation of the present tokamak data base predicts that a sufficient pedestal height is a necessary condition for the success of ITER.

  17. Spontaneous Regression of Herniated Lumbar Disc with New Disc Protrusion in the Adjacent Level.

    Science.gov (United States)

    Hakan, Tayfun; Gürcan, Serkan

    2016-01-01

    Spontaneous regression of herniated lumbar discs was reported occasionally. The mechanisms proposed for regression of disc herniation are still incomplete. This paper describes and discusses a case of spontaneous regression of herniated lumbar discs with a new disc protrusion in the adjacent level. A 41-year-old man was admitted with radiating pain and numbness in the left lower extremity with a left posterolateral disc extrusion at L5-S1 level. He was admitted to hospital with low back pain due to disc herniation caudally immigrating at L4-5 level three years ago. He refused the surgical intervention that was offered and was treated conservatively at that time. He had no neurological deficit and a history of spontaneous regression of the extruded lumbar disc; so, a conservative therapy, including bed rest, physical therapy, nonsteroidal anti-inflammatory drugs, and analgesics, was advised. In conclusion, herniated lumbar disc fragments may regress spontaneously. Reports are prone to advise conservative treatment for extruded or sequestrated lumbar disc herniations. However, these patients should be followed up closely; new herniation at adjacent/different level may occur. Furthermore, it is important to know which herniated disk should be removed and which should be treated conservatively, because disc herniation may cause serious complications as muscle weakness and cauda equine syndrome. PMID:27429818

  18. Spontaneous Regression of Herniated Lumbar Disc with New Disc Protrusion in the Adjacent Level

    Directory of Open Access Journals (Sweden)

    Tayfun Hakan

    2016-01-01

    Full Text Available Spontaneous regression of herniated lumbar discs was reported occasionally. The mechanisms proposed for regression of disc herniation are still incomplete. This paper describes and discusses a case of spontaneous regression of herniated lumbar discs with a new disc protrusion in the adjacent level. A 41-year-old man was admitted with radiating pain and numbness in the left lower extremity with a left posterolateral disc extrusion at L5-S1 level. He was admitted to hospital with low back pain due to disc herniation caudally immigrating at L4-5 level three years ago. He refused the surgical intervention that was offered and was treated conservatively at that time. He had no neurological deficit and a history of spontaneous regression of the extruded lumbar disc; so, a conservative therapy, including bed rest, physical therapy, nonsteroidal anti-inflammatory drugs, and analgesics, was advised. In conclusion, herniated lumbar disc fragments may regress spontaneously. Reports are prone to advise conservative treatment for extruded or sequestrated lumbar disc herniations. However, these patients should be followed up closely; new herniation at adjacent/different level may occur. Furthermore, it is important to know which herniated disk should be removed and which should be treated conservatively, because disc herniation may cause serious complications as muscle weakness and cauda equine syndrome.

  19. Tasting edge effects

    CERN Document Server

    Bocquet, L

    2006-01-01

    We show that the baking of potato wedges constitutes a crunchy example of edge effects, which are usually demonstrated in electrostatics. A simple model of the diffusive transport of water vapor around the potato wedges shows that the water vapor flux diverges at the sharp edges in analogy with its electrostatic counterpart. This increased evaporation at the edges leads to the crispy taste of these parts of the potatoes.

  20. Effect of Photoselective Vaporization Prostatectomy on Lower Urinary Tract Symptoms in Benign Prostatic Hyperplasia With or Without Intravesical Prostatic Protrusion

    OpenAIRE

    Kim, Myung Soo; Park, Kyung Kgi; Chung, Byung Ha; Lee, Seung Hwan

    2013-01-01

    Purpose Intravesical protrusion of the prostate (IPP) can affect voiding. We evaluated the improvement in lower urinary tract symptoms and patient satisfaction after laser prostate photovaporization in benign prostatic hyperplasia (BPH) patients with or without IPP. Materials and Methods This prospective study included 134 patients who underwent GreenLight HPS laser photoselective vaporization prostatectomy (PVP) between January 2010 and July 2011 patient. Preoperative IPP was evaluated by us...

  1. Heat transfer and friction factor characteristics of rectangular channel solar air heater duct having protrusions as roughness element

    Directory of Open Access Journals (Sweden)

    Maneesh Kaushal, Varun

    2012-01-01

    Full Text Available An experimental investigation has been carried out to see the effect of roughness element on heat transfer and friction factor on the absorber plate of the solar air heater. The roughness provided is in the form of protrusions which are arranged in an arc pattern. This paper presents an investigation to study the effect of protruded geometry on heat transfer coefficient and friction factor in an artificially roughened solar air heater duct. The pair of protrusion geometry arc angle (α of 45o is mounted on the test section of duct to create a longitudinal flow through test section. Measurements are carried out for rectangular duct which has aspect ratio (W/H of 11, relative roughness pitch (P/e in the range of 12-24, relative roughness height (e/D of 0.03, ratio of height of protrusion to print diameter (d of 0.3° and Reynolds number (Re ranges from 3600-18100.The results obtained for various relative roughness pitch (P/e has also been compared with smooth one. And on comparison to smooth duct, the roughened duct enhances the heat transfer and friction factor by 2.96 and 2.73 times.

  2. Physiotherapy of postoperation of lumbar disc protrusion%腰椎间盘突出症术后的理疗康复

    Institute of Scientific and Technical Information of China (English)

    孙艳霞

    2002-01-01

    Background:The common treatment of lumbar disc protrusion is operation.After the extirpation of intervertebral disc,patients always need processes of plerosis and healing and always have edema of nerve root and aseptic inflammation.

  3. Comparison of Mallampati test with lower jaw protrusion maneuver in predicting difficult laryngoscopy and intubation

    Directory of Open Access Journals (Sweden)

    Muhammad Irfan Ul Haq

    2013-01-01

    Full Text Available Background: Failure to maintain a patent airway is one of the commonest causes of anesthesia-related morbidity and mortality. Many protocols, algorithms, and different combinations of tested methods for airway assessment have been developed to predict difficult laryngoscopy and intubation. The reported incidence of a difficult intubation varies from 1.5% to 13%. The objective of this study was to compare Mallampati test (MT with lower jaw protrusion (LJP maneuver in predicting difficult laryngoscopy and intubation. Materials and Methods: Seven hundred and sixty patients were included in the study. All the patients underwent MT and LJP maneuver for their airway assessment. After a standardized technique of induction of anesthesia, primary anesthetist performed laryngoscopy and graded it according to the grades described by Cormack and Lehane. Sensitivity, specificity, accuracy, and positive predictive value (PPV and negative predictive value (NPV were calculated for both these tests with 95% confidence interval (CI using conventional laryngoscopy as gold standard. Area under curve was also calculated for both, MT and LJP maneuver. A P < 0.05 was taken as significant. Results: LJP maneuver had higher sensitivity (95.9% vs. 27.1%, NPV (98.7% vs. 82.0%, and accuracy (90.1% vs. 80.3% when compared to MT in predicting difficult laryngoscopy and intubation. Both tests, however, had similar specificity and PPV. There was marked difference in the positive and negative likelihood ratio between LJP and MT. Similarly, the area under the curve favored LJP maneuver over MT. Conclusion: The results of this study show that LJP maneuver is a better test to predict difficult laryngoscopy and tracheal intubation. We recommend the addition of this maneuver to the routine preoperative evaluation of airway.

  4. Comparison of Mallampati test with lower jaw protrusion maneuver in predicting difficult laryngoscopy and intubation

    Science.gov (United States)

    Ul Haq, Muhammad Irfan; Ullah, Hameed

    2013-01-01

    Background: Failure to maintain a patent airway is one of the commonest causes of anesthesia-related morbidity and mortality. Many protocols, algorithms, and different combinations of tested methods for airway assessment have been developed to predict difficult laryngoscopy and intubation. The reported incidence of a difficult intubation varies from 1.5% to 13%. The objective of this study was to compare Mallampati test (MT) with lower jaw protrusion (LJP) maneuver in predicting difficult laryngoscopy and intubation. Materials and Methods: Seven hundred and sixty patients were included in the study. All the patients underwent MT and LJP maneuver for their airway assessment. After a standardized technique of induction of anesthesia, primary anesthetist performed laryngoscopy and graded it according to the grades described by Cormack and Lehane. Sensitivity, specificity, accuracy, and positive predictive value (PPV) and negative predictive value (NPV) were calculated for both these tests with 95% confidence interval (CI) using conventional laryngoscopy as gold standard. Area under curve was also calculated for both, MT and LJP maneuver. A P < 0.05 was taken as significant. Results: LJP maneuver had higher sensitivity (95.9% vs. 27.1%), NPV (98.7% vs. 82.0%), and accuracy (90.1% vs. 80.3%) when compared to MT in predicting difficult laryngoscopy and intubation. Both tests, however, had similar specificity and PPV. There was marked difference in the positive and negative likelihood ratio between LJP and MT. Similarly, the area under the curve favored LJP maneuver over MT. Conclusion: The results of this study show that LJP maneuver is a better test to predict difficult laryngoscopy and tracheal intubation. We recommend the addition of this maneuver to the routine preoperative evaluation of airway. PMID:24106353

  5. Polymer solar cell modules prepared using roll-to-roll methods: Knife-over-edge coating, slot-die coating and screen printing

    Energy Technology Data Exchange (ETDEWEB)

    Krebs, Frederik C. [Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2009-04-15

    A complete polymer solar cell module prepared in the ambient atmosphere using all-solution processing with no vacuum steps and full roll-to-roll (R2R) processing is presented. The modules comprise five layers that were prepared on a 175-{mu}m flexible polyethyleneterephthalate (PET) substrate with an 80-nm layer of transparent conducting indium-tin oxide (ITO). The ITO layer was first patterned by screen printing an etch resist followed by etching. The second layer was applied by either knife-over-edge (KOE) coating or slot-die coating a solution of zinc oxide nanoparticles (ZnO-nps) followed by curing. The second layer comprised a mixture of the thermocleavable poly-(3-(2-methylhexan-2-yl)-oxy-carbonyldithiophene) (P3MHOCT) and ZnO-nps and was applied by a modified slot-die coating procedure, enabling slow coating speeds with low viscosity and low surface tension ink solutions. The third layer was patterned into stripes and juxtaposed with the ITO layer. The fourth layer comprised screen-printed or slot-die-coated PEDOT:PSS and the fifth and the final layer comprised a screen-printed or slot-die-coated silver electrode. The final module dimensions were 28 cm x 32 cm and presented four individual solar cell modules: a single-stripe cell, a two-stripe serially connected module, a three-stripe serially connected module and finally an eight-stripe serially connected module. The length of the individual stripes was 25 cm and the width was 0.9 cm. With overlaps of the individual layers this gave a width of the active layer of 0.6 cm and an active area for each stripe of 15 cm{sup 2}. The performance was increased ten fold compared to mass-produced modules employing screen printing for all five layers of the device. The processing speeds employed for the R2R processed layers were in the range of 40-50 m h{sup -1}. Finally a comparison is made with the state of the art represented by P3HT-PCBM as the active layer and full R2R solution processing using slot-die coating

  6. Syndecan-1 controls cell migration by activating Rap1 to regulate focal adhesion disassembly

    OpenAIRE

    Altemeier, William A.; Schlesinger, Saundra Y.; Buell, Catherine A.; Parks, William C.; Chen, Peter

    2012-01-01

    After injury, residual epithelial cells coordinate contextual clues from cell–cell and cell–matrix interactions to polarize and migrate over the wound bed. Protrusion formation, cell body translocation and rear retraction is a repetitive process that allows the cell to move across the substratum. Fundamental to this process is the assembly and disassembly of focal adhesions that facilitate cell adhesion and protrusion formation. Here, we identified syndecan-1 as a regulator of focal adhesion ...

  7. Adobe Edge Quickstart Guide

    CERN Document Server

    Labrecque, Joseph

    2012-01-01

    Adobe Edge Quickstart Guide is a practical guide on creating engaging content for the Web with Adobe's newest HTML5 tool. By taking a chapter-by-chapter look at each major aspect of Adobe Edge, the book lets you digest the available features in small, easily understandable chunks, allowing you to start using Adobe Edge for your web design needs immediately. If you are interested in creating engaging motion and interactive compositions using web standards with professional tooling, then this book is for you. Those with a background in Flash Professional wanting to get started quickly with Adobe

  8. Color image retrieval using edge and edge-spatial features

    Institute of Scientific and Technical Information of China (English)

    Chaobing Huang; Quan Liu

    2006-01-01

    @@ A novel methodology to integrate edge feature and edge-spatial feature of an image is proposed. The edge feature is described by edge histogram of image, the edge-spatial feature is described by spatial distribution of pixels of identical edge value in the image. Experimental results show that the method can achieve better retrieval performance, especially for color natural images with more complex spatial layout.

  9. Theory of edge radiation

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni; Schneidmiller, Evgeni; Yurkov, Mikhail

    2008-01-01

    We formulate a complete theory of Edge Radiation based on a novel method relying on Fourier Optics techniques. Similar types of radiation like Transition Undulator Radiation are addressed in the framework of the same formalism. Special attention is payed in discussing the validity of approximations upon which the theory is built. Our study makes consistent use of both similarity techniques and comparisons with numerical results from simulation. We discuss both near and far zone. Physical understanding of many asymptotes is discussed. Based on the solution of the field equation with a tensor Green's function technique, we also discuss an analytical model to describe the presence of a vacuum chamber. In particular, explicit calculations for a circular vacuum chamber are reported. Finally, we consider the use of Edge Radiation as a tool for electron beam diagnostics. We discuss Coherent Edge Radiation, Extraction of Edge Radiation by a mirror, and other issues becoming important at high electron energy and long ...

  10. Adobe Edge Preview 3

    CERN Document Server

    Grover, Chris

    2011-01-01

    Want to use an Adobe tool to design animated web graphics that work on iPhone and iPad? You've come to the right book. Adobe Edge Preview 3: The Missing Manual shows you how to build HTML5 graphics using simple visual tools. No programming experience? No problem. Adobe Edge writes the underlying code for you. With this eBook, you'll be designing great-looking web elements in no time. Get to know the workspace. Learn how Adobe Edge Preview 3 performs its magic.Create and import graphics. Make drawings with Edge's tools, or use art you designed in other programs.Work with text. Build menus, lab

  11. Memristive fuzzy edge detector

    CERN Document Server

    Merrikh-Bayat, Farnood

    2011-01-01

    Fuzzy inference systems always suffer from the lack of efficient structures or platforms for their hardware implementation. In this paper, we tried to overcome this problem by proposing new method for the implementation of those fuzzy inference systems which use fuzzy rule base to make inference. To achieve this goal, we have designed a multi-layer neuro-fuzzy computing system based on the memristor crossbar structure by introducing some new concepts like fuzzy minterms. Although many applications can be realized through the use of our proposed system, in this study we show how the fuzzy XOR function can be constructed and how it can be used to extract edges from grayscale images. Our memristive fuzzy edge detector (implemented in analog form) compared with other common edge detectors has this advantage that it can extract edges of any given image all at once in real-time.

  12. Edge Effects and Huanglongbing

    OpenAIRE

    Luo, W.; Anco, D J; Gottwald, T. R.; Irey, M. S.

    2014-01-01

    Huanglongbing (HLB), spread by a psyllid vector, is globally considered a major threat to commercial and sustainable citrus production. Better understanding of the vector-mediated patterns of HLB spread is essential to inform and maximize disease management. From previous studies, edge effects are a significant characteristic of the HLB pathosystem and have been observed predominately in larger plantings. In this study, we investigated 1) the impact of different edge classes and orientations,...

  13. Compressor leading edges

    OpenAIRE

    Goodhand, Martin

    2011-01-01

    Compressor blades often have a small 'spike' in the surface pressure distribution at the leading edge. This may result from blade erosion, manufacture defects or compromises made in the original design process. In this thesis it is shown that these spikes will increase the loss generated by a blade only when they become large enough to initiate boundary layer transition at the leading edge through a separation bubble; this process increases profile loss by about 30%. A criterion is presen...

  14. A clinico-radiographic analysis of sagittal condylar guidance determined by protrusive interocclusal registration and panoramic radiographic images in humans

    Directory of Open Access Journals (Sweden)

    D Krishna Prasad

    2012-01-01

    Full Text Available Purpose: To evaluate the correlation between sagittal condylar guidance obtained by protrusive interocclusal records and panoramic radiograph tracing methods in human dentulous subjects. Materials and Methods: The sagittal condylar guidance was determined in 75 dentulous subjects by protrusive interocclusal records using Aluwax through a face bow transfer (HANAU™ Spring Bow, Whip Mix Corporation, USA to a semi-adjustable articulator (HANAU™ Wide-Vue Articulator, Whip Mix Corporation, USA. In the same subjects, the sagittal outline of the articular eminence and glenoid fossa was traced in panoramic radiographs. The sagittal condylar path inclination was constructed by joining the heights of curvature in the glenoid fossa and the corresponding articular eminence. This was then related to the constructed Frankfurt′s horizontal plane to determine the radiographic angle of sagittal condylar guidance. Results: A strong positive correlation existed between right and left condylar guidance by the protrusive interocclusal method (P 0.000 and similarly by the radiographic method (P 0.013. The mean difference between the condylar guidance obtained using both methods were 1.97° for the right side and 3.18° for the left side. This difference between the values by the two methods was found to be highly significant for the right (P 0.003 and left side (P 0.000, respectively. The sagittal condylar guidance obtained from both methods showed a significant positive correlation on right (P 0.000 and left side (P 0.015, respectively. Conclusion: Panoramic radiographic tracings of the sagittal condylar path guidance may be made relative to the Frankfurt′s horizontal reference plane and the resulting condylar guidance angles used to set the condylar guide settings of semi-adjustable articulators.

  15. The Edge supersonic transport

    Science.gov (United States)

    Agosta, Roxana; Bilbija, Dushan; Deutsch, Marc; Gallant, David; Rose, Don; Shreve, Gene; Smario, David; Suffredini, Brian

    1992-01-01

    As intercontinental business and tourism volumes continue their rapid expansion, the need to reduce travel times becomes increasingly acute. The Edge Supersonic Transport Aircraft is designed to meet this demand by the year 2015. With a maximum range of 5750 nm, a payload of 294 passengers and a cruising speed of M = 2.4, The Edge will cut current international flight durations in half, while maintaining competitive first class, business class, and economy class comfort levels. Moreover, this transport will render a minimal impact upon the environment, and will meet all Federal Aviation Administration Part 36, Stage III noise requirements. The cornerstone of The Edge's superior flight performance is its aerodynamically efficient, dual-configuration design incorporating variable-geometry wingtips. This arrangement combines the benefits of a high aspect ratio wing at takeoff and low cruising speeds with the high performance of an arrow-wing in supersonic cruise. And while the structural weight concerns relating to swinging wingtips are substantial, The Edge looks to ever-advancing material technologies to further increase its viability. Heeding well the lessons of the past, The Edge design holds economic feasibility as its primary focus. Therefore, in addition to its inherently superior aerodynamic performance, The Edge uses a lightweight, largely windowless configuration, relying on a synthetic vision system for outside viewing by both pilot and passengers. Additionally, a fly-by-light flight control system is incorporated to address aircraft supersonic cruise instability. The Edge will be produced at an estimated volume of 400 aircraft and will be offered to airlines in 2015 at $167 million per transport (1992 dollars).

  16. Coordination of glioblastoma cell motility by PKCι

    Directory of Open Access Journals (Sweden)

    Baldwin R Mitchell

    2010-09-01

    Full Text Available Abstract Background Glioblastoma is one of the deadliest forms of cancer, in part because of its highly invasive nature. The tumor suppressor PTEN is frequently mutated in glioblastoma and is known to contribute to the invasive phenotype. However the downstream events that promote invasion are not fully understood. PTEN loss leads to activation of the atypical protein kinase C, PKCι. We have previously shown that PKCι is required for glioblastoma cell invasion, primarily by enhancing cell motility. Here we have used time-lapse videomicroscopy to more precisely define the role of PKCι in glioblastoma. Results Glioblastoma cells in which PKCι was either depleted by shRNA or inhibited pharmacologically were unable to coordinate the formation of a single leading edge lamellipod. Instead, some cells generated multiple small, short-lived protrusions while others generated a diffuse leading edge that formed around the entire circumference of the cell. Confocal microscopy showed that this behavior was associated with altered behavior of the cytoskeletal protein Lgl, which is known to be inactivated by PKCι phosphorylation. Lgl in control cells localized to the lamellipod leading edge and did not associate with its binding partner non-muscle myosin II, consistent with it being in an inactive state. In PKCι-depleted cells, Lgl was concentrated at multiple sites at the periphery of the cell and remained in association with non-muscle myosin II. Videomicroscopy also identified a novel role for PKCι in the cell cycle. Cells in which PKCι was either depleted by shRNA or inhibited pharmacologically entered mitosis normally, but showed marked delays in completing mitosis. Conclusions PKCι promotes glioblastoma motility by coordinating the formation of a single leading edge lamellipod and has a role in remodeling the cytoskeleton at the lamellipod leading edge, promoting the dissociation of Lgl from non-muscle myosin II. In addition PKCι is required

  17. Edge detection depends on achromatic channel in Drosophila melanogaster.

    Science.gov (United States)

    Zhou, Yanqiong; Ji, Xiaoxiao; Gong, Haiyun; Gong, Zhefeng; Liu, Li

    2012-10-01

    Edges represent important information in object recognition, and thus edge detection is crucial for animal survival. Various types of edges result from visual contrast, such as luminance contrast and color contrast. So far, the molecular and neural mechanisms underlying edge detection and the relationship between different edge information-processing pathways have been largely undemonstrated. In the present study, using a color light-emitting-diode-based Buridan's paradigm, we demonstrated that a blue/green demarcation is able to generate edge-orientation behavior in the adult fly. There is a blue/green intensity ratio, the so-called point of equal luminance, at which wild-type flies did not show obvious orientation behavior towards edges. This suggests that orientation behavior towards edges is dependent on luminance contrast in Drosophila. The results of mutants ninaE(17) and sev(LY3);rh5(2);rh6(1) demonstrated that achromatic R1-R6 photoreceptor cells, but not chromatic R7/R8 photoreceptor cells, were necessary for orientation behavior towards edges. Moreover, ectopic expression of rhodopsin 4 (Rh4), Rh5 or Rh6 could efficiently restore the edge-orientation defect in the ninaE(17) mutant. Altogether, our results show that R1-R6 photoreceptor cells are both necessary and sufficient for orientation behavior towards edges in Drosophila. PMID:22735352

  18. Cell-cell interactions impacts on the rate of swarm expansion and the edge shape of a colony swarming Pseudomonas aeruginosa

    Science.gov (United States)

    Amiri, Aboutaleb; Tierra, Giordano; Xu, Zhiliang; Shrout, Joshua; Alber, Mark

    Collective motion has been observed by several bacterial species including the pathogenic bacterium P. aeruginosa. A flagellum at the pole is known to generate a self-propulsion motion. However, the role of type IV pili (TFP), distributed on the cell membrane, during swarming needs to be investigated in more details. In this work we introduce a model that combines the hydrodynamic and biophysical interactions in order to study the impact of the TFP interactions on swarming behavior of the colony. The model describes the motion and interactions of rod-shaped self propelled bacteria inside a thin liquid film. It also includes the equations describing the production and diffusion of surfactant rhamnolipids that is responsible for extraction of water from substrate, and Marangoni driven expansion of the thin liquid film by altering the surface tension. We show that TFP interactions are responsible for slower expansion rate of colonies of TFP deficient mutants compared to wild type. Experimental observations were used to calibrate the model and verify the model assumptions and predictions.

  19. Polymer solar cell modules prepared using roll-to-roll methods: Knife-over-edge coating, slot-die coating and screen printing

    DEFF Research Database (Denmark)

    Krebs, Frederik C

    2009-01-01

    -nm layer of transparent conducting indium–tin oxide (ITO). The ITO layer was first patterned by screen printing an etch resist followed by etching. The second layer was applied by either knife-over-edge (KOE) coating or slot-die coating a solution of zinc oxide nanoparticles (ZnO-nps) followed...

  20. A New Edge-directed Subpixel Edge Localization Method

    Institute of Scientific and Technical Information of China (English)

    于新瑞; 徐威; 王石刚; 李倩

    2004-01-01

    Localization of the inspected chip image is one of the key problems with machine vision aided surface mount devices (SMD) and other micro-electronic equipments. This paper presents a new edge-directed subpixel edge localization method. The image is divided into two regions, edge and non-edge, using edge detection to emphasize the edge feature. Since the edges of the chip image are straight, they have straight-line characteristics locally and globally. First,the line segments of the straight edge are located to subpixel precision, according to their local straight properties, in a 3 × 3 neighborhood of the edge region. Second, the subpixel midpoints of the line segments are computed. Finally, the straight edge is fitted using the midpoints and the least square method, according to its global straight property in the entire edge region. In this way, the edge is located to subpixel precision. While fitting the edge, the irregular points are eliminated by the angles of the line segments to improve the precision. We can also distinguish different edges and their intersections using the angles of the line segments and distances between the edge points, then give the vectorial result of the image edge with high precision.

  1. On finite edge-primitive and edge-quasiprimitive graphs

    OpenAIRE

    Giudici, Michael; Li, Cai Heng

    2009-01-01

    Many famous graphs are edge-primitive, for example, the Heawood graph, the Tutte--Coxeter graph and the Higman--Sims graph. In this paper we systematically analyse edge-primitive and edge-quasiprimitive graphs via the O'Nan--Scott Theorem to determine the possible edge and vertex actions of such graphs. Many interesting examples are given and we also determine all $G$-edge-primitive graphs for $G$ an almost simple group with socle $PSL(2,q)$.

  2. Controlled synthesis and investigation of the mechanism of formation of hollow hemispherical protrusions on laurate anion-intercalated Zn/Al layered double hydroxide hybrid films.

    Science.gov (United States)

    Yue, Caili; Chen, Hongyun; Xu, Sailong; Zhang, Fazhi

    2012-11-01

    Films of laurate (La) anion-intercalated zinc-aluminum layered double hydroxides (ZnAl-La-LDHs) with hollow hemispherical protrusions on the surface of the hybrid film have been conveniently prepared by an ion-exchange reaction of a nitrate-containing LDH film previously grown in situ on a porous anodic alumina/aluminum (PAO/Al) substrate. No template is required to form the hemispherical protrusions, thus avoiding a complicated template removal process. The dimensions, morphology, and resistance to bursting of the hollow hemispherical protrusions can be easily tuned by varying the experimental conditions such as sodium laurate concentration, reaction time, and reaction temperature. The evolution of the hollow protrusions was investigated by scanning electron microscopy (SEM), and a "bubble template-reconfiguration assembly" mechanism, in which air bubbles on the film surface act as a template, has been proposed to explain their formation. When the ion-exchange reaction was carried out on a film that had been treated by ultrasound to eliminate surface air bubbles, no hemispherical protrusions were formed, which is consistent with the proposed mechanism. PMID:22840873

  3. Matrix metalloproteinases regulate the formation of dendritic spine head protrusions during chemically induced long-term potentiation.

    Directory of Open Access Journals (Sweden)

    Zsuzsanna Szepesi

    Full Text Available Dendritic spines are are small membranous protrusions that extend from neuronal dendrites and harbor the majority of excitatory synapses. Increasing evidence has shown that matrix metalloproteinases (MMPs, a family of extracellularly acting and Zn(2+-dependent endopeptidases, are able to rapidly modulate dendritic spine morphology. Spine head protrusions (SHPs are filopodia-like processes that extend from the dendritic spine head, representing a form of postsynaptic structural remodeling in response to altered neuronal activity. Herein, we show that chemically induced long-term potentiation (cLTP in dissociated hippocampal cultures upregulates MMP-9 activity that controls the formation of SHPs. Blocking of MMPs activity or microtubule dynamics abolishes the emergence of SHPs. In addition, autoactive recombinant MMP-9, promotes the formation of SHPs in organotypic hippocampal slices. Furthermore, spines with SHPs gained postsynaptic α-amino-3-hydroxyl-5-methyl-4-isoxazole propionic acid (AMPA receptors upon cLTP and the synaptic delivery of AMPA receptors was controlled by MMPs. The present results strongly imply that MMP-9 is functionally involved in the formation of SHPs and the control of postsynaptic receptor distribution upon cLTP.

  4. Magnetohydrodynamics simulation of 300 KA novel cell for aluminum electrolysis

    Directory of Open Access Journals (Sweden)

    Y. Song

    2015-10-01

    Full Text Available A novel cathode with cylindrical protrusions was presented to investigate the effect of protrusions on the electromagnetic field and flow field in the aluminum electrolysis cell. Results show that by using the novel cathode, the maximum horizontal electromagnetic force and velocity at 2/3 height of the metal pad were reduced by 21 % and 41 % respectively, and the metal - bath interface wave decreased by 0,69 cm. The metal pad flows around protrusions. Eddies due to boundary layer separation are beneficial to the dissolution of alumina.

  5. Canny Edge Detection using Verilog

    OpenAIRE

    D Narayana Reddy*; , Mohan A R2; , Subhramanya Bhat3

    2014-01-01

    Edge detection is one of the key stages in image processing and objects identification. The Canny Edge Detector is one of the most widely used edge detection algorithm due to its good performance. Edge detection carries preprocessing step for many image processing algorithms such as image enhancement, image segmentation, tracking and image/video coding. Canny’s edge detection algorithm that results in significantly reduced memory requirements decreased latency and increased th...

  6. Edge effects in magnetoplasmas

    OpenAIRE

    Suttorp, L G

    1995-01-01

    Edge effects in magnetized charged-particle systems are discussed with the help of a multiple-reflection expansion for the Green function. The profiles of the density and the electric current are determined both for the non-degenerate and the highly degenerate case. The asymptotic form of the profiles near the bulk is found to be exponentially decaying in both cases.

  7. AN EXPERIMENTAL INVESTIGATION OF PRESSURE AND CAVITATION CHARACTERISTICS OF HIGH VELOCITY FLOW OVER A CYLINDRICAL PROTRUSION IN THE PRESENCE AND ABSENCE OF AERATION

    Institute of Scientific and Technical Information of China (English)

    DONG Zhi-yong; LIU Zhi-ping; WU Yi-hong; ZHANG Dong

    2008-01-01

    This article experimentally investigated the pressure and cavitation characteristics of high velocity flow over a surface irregularity with and without aeration in a non-circulating water tunnel system. The surface irregularity is a cylindrical protrusion made of stainless steel of 6 mm diameter and 2 mm height. Pressures with and without aeration were measured with MPX400D pressure transducers and real-timely acquired by a SINOCERA YE6263 data acquisition system. Variations in flow regimes with and without aeration were observed. Pressure profiles and their variations with air concentration upper and lower cylindrical protrusion on the invert and obvert walls were determined. Variations of cavitation number with air concentration lower cylindrical protrusion were analyzed. Also, cavitation numbers in the presence and absence of aeration were compared.

  8. Dictionary based Approach to Edge Detection

    CERN Document Server

    Chandra, Nitish

    2015-01-01

    Edge detection is a very essential part of image processing, as quality and accuracy of detection determines the success of further processing. We have developed a new self learning technique for edge detection using dictionary comprised of eigenfilters constructed using features of the input image. The dictionary based method eliminates the need of pre or post processing of the image and accounts for noise, blurriness, class of image and variation of illumination during the detection process itself. Since, this method depends on the characteristics of the image, the new technique can detect edges more accurately and capture greater detail than existing algorithms such as Sobel, Prewitt Laplacian of Gaussian, Canny method etc which use generic filters and operators. We have demonstrated its application on various classes of images such as text, face, barcodes, traffic and cell images. An application of this technique to cell counting in a microscopic image is also presented.

  9. Superpixel edges for boundary detection

    Energy Technology Data Exchange (ETDEWEB)

    Moya, Mary M.; Koch, Mark W.

    2016-07-12

    Various embodiments presented herein relate to identifying one or more edges in a synthetic aperture radar (SAR) image comprising a plurality of superpixels. Superpixels sharing an edge (or boundary) can be identified and one or more properties of the shared superpixels can be compared to determine whether the superpixels form the same or two different features. Where the superpixels form the same feature the edge is identified as an internal edge. Where the superpixels form two different features, the edge is identified as an external edge. Based upon classification of the superpixels, the external edge can be further determined to form part of a roof, wall, etc. The superpixels can be formed from a speckle-reduced SAR image product formed from a registered stack of SAR images, which is further segmented into a plurality of superpixels. The edge identification process is applied to the SAR image comprising the superpixels and edges.

  10. Physical characteristics of "wisps" in the outer edge of the Keeler Gap in Saturn's rings

    Science.gov (United States)

    Arnault, Ethan; Tiscareno, Matthew S.

    2016-05-01

    We present a catalog of detected `wisps', small protrusions of material (0.5 to 2 km) into the Keeler Gap of Saturn's rings from the gap’s outer edge. Wisps are characterized by a sharp trailing edge followed by a slow gradation back into the edge on the leading side, typically extending between 0.1 and 1 degree of longitude (240 to 2400 km). Fewer than 1% of observed wisps deviate from this morphology, the variants having either the sharp edge on the leading side (reversed) or having a more complex morphology (often roughly symmetric about the feature’s midpoint). Focusing on a suite of images taken between Feb 2009 and May 2009, we measure the Daphnis-relative motion of the wisps to be 0.102 +- 0.002 deg/day, which indicates a semimajor axis ~1km inward of the Keeler Gap outer edge (for which the Daphnis-relative mean motion is 0.114 deg/day). We conclude that wisps are most likely the signatures of moonlets ejected from the ring into the Keeler Gap.

  11. Graphene edges; localized edge state and electron wave interference

    Directory of Open Access Journals (Sweden)

    Enoki Toshiaki

    2012-03-01

    Full Text Available The electronic structure of massless Dirac fermion in the graphene hexagonal bipartite is seriously modified by the presence of edges depending on the edge chirality. In the zigzag edge, strongly spin polarized nonbonding edge state is created as a consequence of broken symmetry of pseudo-spin. In the scattering at armchair edges, the K-K’ intervalley transition gives rise to electron wave interference. The presence of edge state in zigzag edges is observed in ultra-high vacuum STM/STS observations. The electron wave interference phenomenon in the armchair edge is observed in the Raman G-band and the honeycomb superlattice pattern with its fine structure in STM images.

  12. Flap Edge Noise Reduction Fins

    Science.gov (United States)

    Khorrami, Mehdi R. (Inventor); Choudhan, Meelan M. (Inventor)

    2015-01-01

    A flap of the type that is movably connected to an aircraft wing to provide control of an aircraft in flight includes opposite ends, wherein at least a first opposite end includes a plurality of substantially rigid, laterally extending protrusions that are spaced apart to form a plurality of fluidly interconnected passageways. The passageways have openings adjacent to upper and lower sides of the flap, and the passageways include a plurality of bends such that high pressure fluid flows from a high pressure region to a low pressure region to provide a boundary condition that inhibits noise resulting from airflow around the end of the flap.

  13. The Transcultural Edge

    OpenAIRE

    Ilaria Vanni

    2016-01-01

    Critical writing about transculturation has a long history in Latin American studies, and more recently the concept has been used to analyse the effects of globalization. This article takes as its point of departure the Latin American genealogy of the idea, and brings it together with the ecological notion of ‘edge’ intended as a transition area between different systems. By bringing transculturation and edge together this paper seeks to understand transculturation as a process in which human...

  14. Forest edges in boreal landscapes - factors affecting edge influence

    OpenAIRE

    Jansson, Ulrika

    2009-01-01

    The boreal forest in Fennoscandia has been subjected to major loss and fragmentation of natural forests due to intensive forestry. This has resulted in that forest edges are now abundant and important landscape features. Edges have documented effects on the structure, function and biodiversity in forests. Edge influence on biodiversity is complex and depends on interactions between many local and regional factors. This thesis focuses on sharp forest edges and their potential to influence biod...

  15. Protein kinase C, focal adhesions and the regulation of cell migration

    DEFF Research Database (Denmark)

    Fogh, Betina S; Multhaupt, Hinke A B; Couchman, John Robert

    2014-01-01

    Cell adhesion to extracellular matrix is a complex process involving protrusive activity driven by the actin cytoskeleton, engagement of specific receptors, followed by signaling and cytoskeletal organization. Thereafter, contractile and endocytic/recycling activities may facilitate migration and...

  16. Intraoral Vertical Ramus Osteotomy Improved the Stomatognathic Function in an Elderly Patient with Mandibular Protrusion:A Case Report

    Directory of Open Access Journals (Sweden)

    Ishihara,Yoshihito

    2010-10-01

    Full Text Available This article reports the successful surgical-orthodontic treatment of an elderly patient with dentofacial deformity and signs and symptoms of temporomandibular disorder (TMD. The patient was a 63-year-old woman with a concave profile due to mandibular protrusion. To correct skeletal deformities, the mandible was posteriorly repositioned by employing intraoral vertical ramus osteotomy (IVRO following presurgical orthodontic treatment. After active treatment for 31 months, the facial profile was significantly improved and satisfactory occlusion was achieved. In addition, TMD symptoms of clicking sounds on the left side and difficulty in mouth opening were resolved. Regarding the findings of magnetic resonance imaging, anterior disc displacement in the opening phase was improved in the temporomandibular joint on the left side. Furthermore, stomatognathic functions were also improved without any aggravation of age-related problems. In conclusion, surgical repositioning of the mandible using IVRO leads to both morphological and functional improvements even in elderly patients.

  17. Training for motor function after removal of nucleus pulposus in protrusion of lumbar intervertebral discs%腰椎间盘突出症髓核摘除术后运动功能训练

    Institute of Scientific and Technical Information of China (English)

    王媛

    2003-01-01

    @@ INTRODUCIION Protrusion of lumbar intervertebral discs is a kind of disease causedby protrusion of nucleus pulposus to vertebral canal due to degen-eration and rupture of lumbar intervertebral discs and stimulationand compression on neighboring nerve roots. Therapeutic effects afteroperation has a direct relationship with postoperative rehabilitationnursing.

  18. Automatic Prompting and Positive Attention to Reduce Tongue Protrusion and Head Tilting by Two Adults with Severe to Profound Intellectual Disabilities

    Science.gov (United States)

    Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Didden, Robert; Pichierri, Sabrina

    2010-01-01

    This study assessed a simple behavioral strategy for reducing stereotypic tongue protrusion and forward head tilting displayed by a woman and a man with severe to profound intellectual disabilities. The strategy involved (a) auditory prompting (i.e., verbal encouragements to keep the tongue in the mouth or the head upright) delivered automatically…

  19. Glutamate induces the elongation of early dendritic protrusions via mGluRs in wild type mice, but not in fragile X mice.

    Directory of Open Access Journals (Sweden)

    Alberto Cruz-Martín

    Full Text Available Fragile X syndrome (FXS, the most common inherited from of autism and mental impairment, is caused by transcriptional silencing of the Fmr1 gene, resulting in the loss of the RNA-binding protein FMRP. Dendritic spines of cortical pyramidal neurons in affected individuals are abnormally immature and in Fmr1 knockout (KO mice they are also abnormally unstable. This could result in defects in synaptogenesis, because spine dynamics are critical for synapse formation. We have previously shown that the earliest dendritic protrusions, which are highly dynamic and might serve an exploratory role to reach out for axons, elongate in response to glutamate. Here, we tested the hypothesis that this process is mediated by metabotropic glutamate receptors (mGluRs and that it is defective in Fmr1 KO mice. Using time-lapse imaging with two-photon microscopy in acute brain slices from early postnatal mice, we find that early dendritic protrusions in layer 2/3 neurons become longer in response to application of glutamate or DHPG, a Group 1 mGluR agonist. Blockade of mGluR5 signaling, which reverses some adult phenotypes of KO mice, prevented the glutamate-mediated elongation of early protrusions. In contrast, dendritic protrusions from KO mice failed to respond to glutamate. Thus, absence of FMRP may impair the ability of cortical pyramidal neurons to respond to glutamate released from nearby pre-synaptic terminals, which may be a critical step to initiate synaptogenesis and stabilize spines.

  20. CT检查在牵引治疗腰椎间盘突出症中的评估作用%Evaluation function of CT examination to traction therapy to lumbar disc protrusion

    Institute of Scientific and Technical Information of China (English)

    丁长伟; 刘丽君; 林楠; 王天君

    2002-01-01

    Objective To investigate whether there is morphological change at intervertebral disc after traction therapy to lumbar disc protrusion. Methods We observed 58 lumbar disc protrusion cases diagnosed by CT and treated with traction therapy with CT again, and compared morphological change of intervertebral disc on CT image before and after treatment. Result Effective rate of traction therapy to lumbar disc protrusion was 84.48% , there was no apparent difference in degree of lumbar disc protrusion, anterior posterior diameter of vertebral canal and lateral crypt width between before and after treatment. Conclusion Traction can relieve effectively clinical symptoms of lumbar disc protrusion, but can't make great change in shape of protruded intervertebral disc.

  1. Push-Edge and Slide-Edge: Scrolling by Pushing Against the Viewport Edge

    OpenAIRE

    Malacria, Sylvain; Aceituno, Jonathan; Quinn, Philip; Casiez, Géry; Cockburn, Andy; ROUSSEL, Nicolas

    2015-01-01

    International audience Edge-scrolling allows users to scroll a viewport while simultaneously dragging near or beyond a window’s edge. Common implementations rely on rate control, mapping the distance between the pointer and the edge of the viewport to the scrolling velocity. While ubiquitous in operating systems, edge-scrolling has received little attention, even though previous works suggest that (1) rate control may be suboptimal for isotonic pointing devices like mice and trackpads and ...

  2. Efficient edge domination in regular graphs

    OpenAIRE

    Cardoso, Domingos M.; Cerdeira, J. Orestes; Delorme, Charles; Silva, Pedro C

    2008-01-01

    An induced matching of a graph G is a matching having no two edges joined by an edge. An efficient edge dominating set of G is an induced matching M such that every other edge of G is adjacent to some edge in M. We relate maximum induced matchings and efficient edge dominating sets, showing that efficient edge dominating sets are maximum induced matchings, and that maximum induced matchings on regular graphs with efficient edge dominating sets are efficient edge dominating sets. A ...

  3. Topological number of edge states

    Science.gov (United States)

    Hashimoto, Koji; Kimura, Taro

    2016-05-01

    We show that the edge states of the four-dimensional class A system can have topological charges, which are characterized by Abelian/non-Abelian monopoles. The edge topological charges are a new feature of relations among theories with different dimensions. From this novel viewpoint, we provide a non-Abelian analog of the TKNN number as an edge topological charge, which is defined by an SU(2) 't Hooft-Polyakov BPS monopole through an equivalence to Nahm construction. Furthermore, putting a constant magnetic field yields an edge monopole in a noncommutative momentum space, where D-brane methods in string theory facilitate study of edge fermions.

  4. Topological Number of Edge States

    CERN Document Server

    Hashimoto, Koji

    2016-01-01

    We show that the edge states of the four-dimensional class A system can have topological charges, which are characterized by Abelian/non-Abelian monopoles. The edge topological charges are a new feature of relations among theories with different dimensions. From this novel viewpoint, we provide a non-Abelian analogue of the TKNN number as an edge topological charge, which is defined by an SU(2) 't Hooft-Polyakov BPS monopole through an equivalence to Nahm construction. Furthermore, putting a constant magnetic field yields an edge monopole in a non-commutative momentum space, where D-brane methods in string theory facilitate study of edge fermions.

  5. EDGE COVERING COLORING AND FRACTIONAL EDGE COVERING COLORING

    Institute of Scientific and Technical Information of China (English)

    MIAOLianying; LIUGuizhen

    2002-01-01

    Let G be a graph with edge set E(G).S E(G)is called an edge cover of G if every vertex of G is an end vertex of some edges in S.The edge covering chromatic number of a graph G,denoted by Xc(G),is the maximum size of a partition of E(G) into edge covers of G.It is known that for any graph G with minimum degree δ,δ-1≤Xc(G)≤δ.The fractional edge covering chromatic number of a graph G,denoted by Xcf(G),is the fractional matiching number of the edge covering hypergraph H of G whose vertices are the edges of G and whose hypereges the edge covers of G.In this paper,we study the relation between Xc(G) and δfor any graph G,and give a new simple proof of the inequalities δ-1≤Xc(G)≤δ by the technique of graph coloring.For any graph G,we give an exact formula o Xcf(G),that is,Xcf(G)=min{δ,λ(G)},where λ(G)=minCS/S/2 and the minimum is taken over all noempty subsets S of V(G) and C[S] is the set of edges that have at least one end in S.δ

  6. EDGE COVERING COLORING AND FRACTIONAL EDGE COVERING COLORING

    Institute of Scientific and Technical Information of China (English)

    MIAO Lianying; LIU Guizhen

    2002-01-01

    Let G be a graph with edge set E(G). S _C E(G) is called an edge cover of G if every vertex of G is an end vertex of some edges in S. The edge covering chromatic number of a graph G, denoted by X'c(G) , is the maximum size of a partition of E(G) into edge covers of G. It is known that for any graph G with minimum degree δ, δ - 1 ≤ X'c(G) ≤ δ.The fractional edge covering chromatic number of a graph G, denoted by X'cf(G), is the fractional matching number of the edge covering hypergraph H of G whose vertices are the edges of G and whose hyperedges the edge covers of G. In this paper, we study the relation between X'c(G) and δ for any graph G, and give a new simple proof of the inequalities δ - 1 ≤ X'c(G) ≤ δ by the technique of graph coloring. For any graph G, we give an exact formula of X'cf(G), that is, X'cf(G)=min{δ,λ(G)}, where λ(G)=min |C[S]|/[|S|/2]and the minimum is taken over all noempty subsets S of V(G) and C[S] is the set of edges that have at least one end in S.

  7. FMNL2 drives actin-based protrusion and migration downstream of Cdc42

    DEFF Research Database (Denmark)

    Block, Jennifer; Breitsprecher, Dennis; Kühn, Sonja;

    2012-01-01

    -guanosine triphosphatase Cdc42. Abolition of myristoylation or Cdc42 binding interferes with proper FMNL2 activation, constituting an essential prerequisite for subcellular targeting. In vitro, C-terminal FMNL2 drives elongation rather than nucleation of actin filaments in the presence of profilin. In addition, filament...... establish that the FMNL subfamily member FMNL2 is a novel elongation factor of actin filaments that constitutes the first Cdc42 effector promoting cell migration and actin polymerization at the tips of lamellipodia....

  8. Competing edge networks

    International Nuclear Information System (INIS)

    We introduce a model for a pair of nonlinear evolving networks, defined over a common set of vertices, subject to edgewise competition. Each network may grow new edges spontaneously or through triad closure. Both networks inhibit the other's growth and encourage the other's demise. These nonlinear stochastic competition equations yield to a mean field analysis resulting in a nonlinear deterministic system. There may be multiple equilibria; and bifurcations of different types are shown to occur within a reduced parameter space. This situation models competitive communication networks such as BlackBerry Messenger displacing SMS; or instant messaging displacing emails. -- Highlights: ► A model for edgewise-competing evolving network pairs is introduced. ► Defined competition equations yield to a mean field analysis. ► Multiple equilibrium states and different bifurcation types can occur. ► The system is sensitive to sparse initial conditions and near unstable equilibriums.

  9. Edge-on!

    Science.gov (United States)

    2007-08-01

    Peering at Uranus's Rings as they Swing Edge-on to Earth for the First Time Since their Discovery in 1977 As Uranus coasts through a brief window of time when its rings are edge-on to Earth - a view of the planet we get only once every 42 years - astronomers peering at the rings with ESO's Very Large Telescope and other space or ground-based telescopes are getting an unprecedented view of the fine dust in the system, free from the glare of the bright rocky rings. They may even find a new moon or two. ESO PR Photo 37/07 ESO PR Photo 37/07 The Uranus System "ESO's VLT took data at the precise moment when the rings were edge-on to Earth," said Imke de Pater, of University of California, Berkeley who coordinated the worldwide campaign. She worked with two team members observing in Chile: Daphne Stam of the Technical University Delft in the Netherlands and Markus Hartung of ESO. The observations were done with NACO, one of the adaptive optics instruments installed at the VLT. With adaptive optics, it is possible to obtain images almost free from the blurring effect of the atmosphere. It is as if the 8.2-m telescope were observing from space. Observations were also done with the Keck telescope in Hawaii, the Hubble Space Telescope, and at the Palomar Observatory. "Using different telescopes around the world allows us to observe as much of the changes during the ring-plane crossing as possible: when Uranus sets as seen from the VLT, it can still be observed by the Keck," emphasised Stam. Uranus orbits the Sun in 84 years. Twice during a Uranian year, the rings appear edge-on to Earth for a brief period. The rings were discovered in 1977, so this is the first time for a Uranus ring-crossing to be observed from Earth. The advantage of observations at a ring-plane crossing is that it becomes possible to look at the rings from the shadowed or dark side. From that vantage point, the normally bright outer rings grow fainter because their centimetre- to metre-sized rocks obscure

  10. Edge remap for solids

    Energy Technology Data Exchange (ETDEWEB)

    Kamm, James R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Love, Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robinson, Allen C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Young, Joseph G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ridzal, Denis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-12-01

    We review the edge element formulation for describing the kinematics of hyperelastic solids. This approach is used to frame the problem of remapping the inverse deformation gradient for Arbitrary Lagrangian-Eulerian (ALE) simulations of solid dynamics. For hyperelastic materials, the stress state is completely determined by the deformation gradient, so remapping this quantity effectively updates the stress state of the material. A method, inspired by the constrained transport remap in electromagnetics, is reviewed, according to which the zero-curl constraint on the inverse deformation gradient is implicitly satisfied. Open issues related to the accuracy of this approach are identified. An optimization-based approach is implemented to enforce positivity of the determinant of the deformation gradient. The efficacy of this approach is illustrated with numerical examples.

  11. Tratamento da má oclusão de Classe II, divisão 1 de Angle, com protrusão maxilar utilizando-se recursos ortopédicos Class II, division 1, with maxillar protrusion's treatment employing orthopedic approachs

    Directory of Open Access Journals (Sweden)

    Carla Maria Melleiro Gimenez

    2007-12-01

    Full Text Available OBJETIVO: o presente trabalho tem o propósito de apresentar uma revisão da literatura acerca do tratamento da má oclusão de Classe II, divisão 1 de Angle, tendo a protrusão maxilar como o principal componente dessa má oclusão, durante a fase de crescimento e desenvolvimento craniofacial. Serão apresentadas as características de cada um desses aparelhos, os seus componentes, a forma adequada de utilização, os seus mecanismos de ação e, principalmente, os seus efeitos em todo o complexo dentofacial. CONCLUSÃO: nos casos em que se verifica apenas a protrusão maxilar, sem envolvimento mandibular, e se faz necessário o controle vertical, pode ser indicado o AEB, conjugado ao aparelho removível derivado do aparelho preconizado por Thurow. Já nas situações de combinação da protrusão maxilar com a retrusão mandibular, uma opção de tratamento é o ativador combinado à ancoragem extrabucal.AIM: The purpose of this research is to review the literature about the treatment of Class II, division 1 malocclusion with maxillary protrusion, during the growth and development period. This review addresses the characteristics of these appliances, their components, correct use, action mechanisms, and mainly their consequences in dentofacial complex. CONCLUSIONS: In patients with maxillary protrusion and with no mandibular component, it may be indicated the use of a maxillary splint similar to the one suggested by Thurow. However, in patients with maxillary protrusion and mandibular retrusion, it may be indicated an activator associated with extra oral anchorage.

  12. Edge phonons in black phosphorus.

    Science.gov (United States)

    Ribeiro, H B; Villegas, C E P; Bahamon, D A; Muraca, D; Castro Neto, A H; de Souza, E A T; Rocha, A R; Pimenta, M A; de Matos, C J S

    2016-01-01

    Black phosphorus has recently emerged as a new layered crystal that, due to its peculiar and anisotropic crystalline and electronic band structures, may have important applications in electronics, optoelectronics and photonics. Despite the fact that the edges of layered crystals host a range of singular properties whose characterization and exploitation are of utmost importance for device development, the edges of black phosphorus remain poorly characterized. In this work, the atomic structure and behaviour of phonons near different black phosphorus edges are experimentally and theoretically studied using Raman spectroscopy and density functional theory calculations. Polarized Raman results show the appearance of new modes at the edges of the sample, and their spectra depend on the atomic structure of the edges (zigzag or armchair). Theoretical simulations confirm that the new modes are due to edge phonon states that are forbidden in the bulk, and originated from the lattice termination rearrangements. PMID:27412813

  13. Edge colouring by total labellings

    DEFF Research Database (Denmark)

    Brandt, Stephan; Rautenbach, D.; Stiebitz, M.;

    2010-01-01

    We introduce the concept of an edge-colouring total k-labelling. This is a labelling of the vertices and the edges of a graph G with labels 1, 2, ..., k such that the weights of the edges define a proper edge colouring of G. Here the weight of an edge is the sum of its label and the labels of its...... two endvertices. We define χ (G) to be the smallest integer k for which G has an edge-colouring total k-labelling. This parameter has natural upper and lower bounds in terms of the maximum degree Δ of G : ⌈ (Δ + 1) / 2 ⌉ ≤ χ (G) ≤ Δ + 1. We improve the upper bound by 1 for every graph and prove χ (G...

  14. Insights into the Cell Shape Dynamics of Migrating Dictyostelium discoideum

    Science.gov (United States)

    Driscoll, Meghan; Homan, Tess; McCann, Colin; Parent, Carole; Fourkas, John; Losert, Wolfgang

    2010-03-01

    Dynamic cell shape is a highly visible manifestation of the interaction between the internal biochemical state of a cell and its external environment. We analyzed the dynamic cell shape of migrating cells using the model system Dictyostelium discoideum. Applying a snake algorithm to experimental movies, we extracted cell boundaries in each frame and followed local boundary motion over long time intervals. Using a local motion measure that corresponds to protrusive/retractive activity, we found that protrusions are intermittent and zig-zag, whereas retractions are more sustained and straight. Correlations of this local motion measure reveal that protrusions appear more localized than retractions. Using a local shape measure, curvature, we also found that small peaks in boundary curvature tend to originate at the front of cells and propagate backwards. We will review the possible cytoskeletal origin of these mechanical waves.

  15. Cutting Edge: IL-4, IL-21, and IFN-γ Interact To Govern T-bet and CD11c Expression in TLR-Activated B Cells.

    Science.gov (United States)

    Naradikian, Martin S; Myles, Arpita; Beiting, Daniel P; Roberts, Kenneth J; Dawson, Lucas; Herati, Ramin Sedaghat; Bengsch, Bertram; Linderman, Susanne L; Stelekati, Erietta; Spolski, Rosanne; Wherry, E John; Hunter, Christopher; Hensley, Scott E; Leonard, Warren J; Cancro, Michael P

    2016-08-15

    T-bet and CD11c expression in B cells is linked with IgG2c isotype switching, virus-specific immune responses, and humoral autoimmunity. However, the activation requisites and regulatory cues governing T-bet and CD11c expression in B cells remain poorly defined. In this article, we reveal a relationship among TLR engagement, IL-4, IL-21, and IFN-γ that regulates T-bet expression in B cells. We find that IL-21 or IFN-γ directly promote T-bet expression in the context of TLR engagement. Further, IL-4 antagonizes T-bet induction. Finally, IL-21, but not IFN-γ, promotes CD11c expression independent of T-bet. Using influenza virus and Heligmosomoides polygyrus infections, we show that these interactions function in vivo to determine whether T-bet(+) and CD11c(+) B cells are formed. These findings suggest that T-bet(+) B cells seen in health and disease share the common initiating features of TLR-driven activation within this circumscribed cytokine milieu. PMID:27430719

  16. Protease inhibitors as radioprotectors: a review of ''cutting-edge'' concepts in taming radiation-induced cell death executioners along the mouse GI tract

    International Nuclear Information System (INIS)

    What is now known in radiation biology is that tumor and normal cells after radiotherapy do not simply die as a result of the physiological chaos caused by DNA damage, but rather from a high-ordered triggering and implementation of a complex apoptosis program. The radiosensitivity of normal cells that surround the tumor target is a critical issue, which when successfully altered through the application of a radioprotector, would provide a wider therapeutic window to improve tumor kill. Logically, it is from this standpoint that radioprotection of normal tissues could be achieved by preventing the molecular cascades responsible for cell death itself. We demonstrate from this experiment the modulation of intestinal crypt radiosensitivities in ICR mice after whole-body exposure to 20 Gy gamma-radiation. Addition to protease inhibitors is aimed at blocking the protease executioner pathway during radiation-induced programmed cell death. The radiosensitive intestinal tissue microarchitecture is most intact in mice injected with 400 mg/gm body weight of antipain, an aspartic acid protease inhibitor. Ethylenediamine tetraacetic acid (EDTA), a metalloprotease inhibitor and chelating agent, and gamma-caproic acid (GACA), an inhibitor of fibrinogen, both fail to show promise as radioprotectors based on our intestinal microcolony model. In the light of our recent findings and the accumulation of recent molecular data on concerned protease machineries, a paradigm of radiation cell death in the intestinal system is discussed. (Author)

  17. Interference of wedge-shaped protrusions on the faces of a Griffith crack in biaxial stress. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Boulet, J.A.M. [Tennessee Univ., Knoxville, TN (United States)

    1992-04-01

    An initial investigation of the influence of protrusion interference on the fracture toughness required to prevent unstable propagation of a Griffith crack in a brittle material is described. The interference is caused by relative shear displacement of the crack faces when subjected to remote biaxial stress with neither principal stress parallel to the crack. It is shown that for room temperature cracks smaller than about one centimeter in silicon carbide, or about one millimeter in silicon nitride, the presence of interference changes the fracture stress. A mathematical model based on linear elasticity solutions and including multiple interference sites at arbitrarily specified positions on the crack is presented. Computations of the change in required fracture toughness and its dependence on wedge geometry (size and vertex angle), applied stresses (orientation and magnitude), and location of the interference site are discussed. Results indicate that a single interference site has only a slight effect on required toughness. However, the influence of interference increases monotonically with the number of interference sites. The two-dimensional model described herein is not accurate when the interference sites are closely spaced.

  18. Numerical prediction of the performance of horizontal sand filters as the pitch of the spiral protrusion changes.

    Science.gov (United States)

    Mossad, Ruth; Aral, Hal

    2013-01-01

    The height of vertical sand filters are limited due to their structural cost. A horizontal sand filter may offer a better alternative; however, flow channels to the least resistance zone generated at the top of the filter as the sand gets wet and settles. A horizontal sand filter, internally baffled with spiral protrusion, is numerically modelled to study the effect of these spirals in reducing the channelling and enhancing the filter's effectiveness. Three different spiral pitches, 1.0, 0.75, and 0.5 m have been numerically modelled using Ansys FLUENT software. The parameters investigated were the power needed to run a flow rate through the horizontal filter and the residence time. The results show that as the spiral pitch decreases, the channelling reduces while the power increases. The power needed to pump a given flow rate of water in a 10 m long horizontal filter in all three cases investigated was less than the power needed to pump the same flow rate to the top of a 10 m long vertically standing sand filter. Results also showed that the time required for the flow to traverse through the sand filter increases in a nonlinear fashion as the pitch size decreases; however, the effectiveness of the filter increases. PMID:23676395

  19. High Density Infill in Cracks and Protrusions from the Articular Calcified Cartilage in Osteoarthritis in Standardbred Horse Carpal Bones

    Directory of Open Access Journals (Sweden)

    Sheila Laverty

    2015-04-01

    Full Text Available We studied changes in articular calcified cartilage (ACC and subchondral bone (SCB in the third carpal bones (C3 of Standardbred racehorses with naturally-occurring repetitive loading-induced osteoarthritis (OA. Two osteochondral cores were harvested from dorsal sites from each of 15 post-mortem C3 and classified as control or as showing early or advanced OA changes from visual inspection. We re-examined X-ray micro-computed tomography (µCT image sets for the presence of high-density mineral infill (HDMI in ACC cracks and possible high-density mineralized protrusions (HDMP from the ACC mineralizing (tidemark front (MF into hyaline articular cartilage (HAC. We hypothesized and we show that 20-µm µCT resolution in 10-mm diameter samples is sufficient to detect HDMI and HDMP: these are lost upon tissue decalcification for routine paraffin wax histology owing to their predominant mineral content. The findings show that µCT is sufficient to discover HDMI and HDMP, which were seen in 2/10 controls, 6/9 early OA and 8/10 advanced OA cases. This is the first report of HDMI and HDMP in the equine carpus and in the Standardbred breed and the first to rely solely on µCT. HDMP are a candidate cause for mechanical tissue destruction in OA.

  20. Lumbar disc protrusion therapy by combination drug administration in epidural space%硬膜外腔联合用药治疗腰椎间盘突出症

    Institute of Scientific and Technical Information of China (English)

    尹美华; 杨德荣; 许晶; 马玉清

    2003-01-01

    @@ BACKGROUND: Lumbar disc protrusion was a syndrome dueto degeneration of disc, disruption of fibrous tings and protrusion ofnucleus pulposus and stimulation of cauda equina. It was the mostcommon cause of leg and back pain. it had a high incidence rate andthe patients suffered too greatly to normal work and life. Afternon-operative therapy, symptoms of most patients disappeared orrelieved. Only 10% to 15% of the patients needed operation. Re-cently, combination drug administration in epidural space were usedin lumbar disc protrusion therapy with a highly successful rate andhttle danger.

  1. Edge-edge interactions in stacked graphene nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Silva, Eduardo [ORNL; Terrones Maldonado, Humberto [ORNL; Terrones Maldonado, Mauricio [ORNL; Jia, Xiaoting [Massachusetts Institute of Technology (MIT); Sumpter, Bobby G [ORNL; Dresselhaus, M [Massachusetts Institute of Technology (MIT); Meunier, V. [Rensselaer Polytechnic Institute (RPI)

    2013-01-01

    High-resolution transmission electron microscopy (HRTEM) studies show the dynamics of small graphene platelets on larger graphene layers. The platelets move nearly freely to eventually lock in at well-defined positions close to the edges of the larger underlying graphene sheet. While such movement is driven by a shallow potential energy surface described by an interplane interaction, the lock-in position occurs by via edge-edge interactions of the platelet and the graphene surface located underneath. Here we quantitatively study this behavior using van der Waals density functional calculations. Local interactions at the open edges are found to dictate stacking configurations that are different from Bernal (AB) stacking. These stacking configurations are known to be otherwise absent in edge-free two-dimensional (2D) graphene. The results explain the experimentally observed platelet dynamics and provide a detailed account of the new electronic properties of these combined systems.

  2. Giant edge state splitting at atomically precise graphene zigzag edges

    Science.gov (United States)

    Wang, Shiyong; Talirz, Leopold; Pignedoli, Carlo A.; Feng, Xinliang; Müllen, Klaus; Fasel, Roman; Ruffieux, Pascal

    2016-05-01

    Zigzag edges of graphene nanostructures host localized electronic states that are predicted to be spin-polarized. However, these edge states are highly susceptible to edge roughness and interaction with a supporting substrate, complicating the study of their intrinsic electronic and magnetic structure. Here, we focus on atomically precise graphene nanoribbons whose two short zigzag edges host exactly one localized electron each. Using the tip of a scanning tunnelling microscope, the graphene nanoribbons are transferred from the metallic growth substrate onto insulating islands of NaCl in order to decouple their electronic structure from the metal. The absence of charge transfer and hybridization with the substrate is confirmed by scanning tunnelling spectroscopy, which reveals a pair of occupied/unoccupied edge states. Their large energy splitting of 1.9 eV is in accordance with ab initio many-body perturbation theory calculations and reflects the dominant role of electron-electron interactions in these localized states.

  3. High-efficiency screen-printed solar cell on edge-defined film-fed grown ribbon silicon through optimized rapid belt co-firing of contacts and high-sheet-resistance emitter

    Science.gov (United States)

    Rohatgi, Ajeet; Hilali, Mohamed M.; Nakayashiki, Kenta

    2004-04-01

    High-quality screen-printed contacts were achieved on a high-sheet-resistance emitter (˜100 Ω/sq.) using PV168 Ag paste and rapid co-firing in the belt furnace. The optimized co-firing cycle developed for a 100 Ω/sq. emitter produced 16.1% efficient 4 cm2 planar edge-defined film-fed grown (EFG) ribbon Si cells with a low series-resistance (0.8 Ω cm2), high fill factor of ˜0.77, along with very significant bulk lifetime enhancement from 3 to 100 μs. This represents the highest-efficiency screen-printed EFG Si cells with single-layer antireflection (AR) coating. These cells were fabricated using a simple process involving POCl3 diffusion for a high-sheet-resistance emitter, SiNx AR coating and rapid cofiring of Ag grid and Al-doped back-surface field in a conventional belt furnace. The rapid cofiring process also prevented junction shunting while maintaining very effective SiNx-induced hydrogen passivation of defects, resulting in an average bulk lifetime exceeding 100 μs.

  4. T-Stenting-and-Small-Protrusion Technique for Bifurcation Stenoses After End-to-Side Anastomosis of Transplant Renal Artery and External Iliac Artery: Report of Two Cases

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yong, E-mail: cheny102@163.com; Ye, Peng, E-mail: thomas19871223@163.com [Southern Medical University, Department of Interventional Radiology, Nanfang Hospital (China); Jiang, Wen-jin, E-mail: 18653501187@163.com [Yantai Yuhuangding Hospital (China); Ma, Shuo-yi, E-mail: mazelong123456789@126.com; Zhao, Jian-bo, E-mail: zhaojianbohgl@163.com; Zeng, Qing-le, E-mail: doctorzengqingle@126.com [Southern Medical University, Department of Interventional Radiology, Nanfang Hospital (China)

    2015-10-15

    Bifurcation stenoses after end-to-side anastomosis of transplant renal artery (TRA) and external iliac artery (EIA), including stenoses at the anastomosis and the iliac artery proximal to the TRA, are rare. In the present article, we report two successfully managed cases of bifurcation stenoses after end-to-side anastomosis of the TRA and EIA using the technique of T-stenting and small protrusion (TAP stenting)

  5. T-Stenting-and-Small-Protrusion Technique for Bifurcation Stenoses After End-to-Side Anastomosis of Transplant Renal Artery and External Iliac Artery: Report of Two Cases

    International Nuclear Information System (INIS)

    Bifurcation stenoses after end-to-side anastomosis of transplant renal artery (TRA) and external iliac artery (EIA), including stenoses at the anastomosis and the iliac artery proximal to the TRA, are rare. In the present article, we report two successfully managed cases of bifurcation stenoses after end-to-side anastomosis of the TRA and EIA using the technique of T-stenting and small protrusion (TAP stenting)

  6. Rock Segmentation through Edge Regrouping

    Science.gov (United States)

    Burl, Michael

    2008-01-01

    Rockster is an algorithm that automatically identifies the locations and boundaries of rocks imaged by the rover hazard cameras (hazcams), navigation cameras (navcams), or panoramic cameras (pancams). The software uses edge detection and edge regrouping to identify closed contours that separate the rocks from the background.

  7. Edge Detection Using Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    B. Govinda Lakshmi

    2014-09-01

    Full Text Available Edge detection is still difficult task in the image processing field. In this paper we implemented fuzzy techniques for detecting edges in the image. This algorithm also works for medical images. In this paper we also explained about Fuzzy inference system, which is more robust to contrast and lighting variations.

  8. Fission of Halving Edges Graphs

    OpenAIRE

    Khovanova, Tanya; Yang, Dai

    2013-01-01

    In this paper we discuss an operation on halving edges graph that we call fission. Fission replaces each point in a given configuration with a small cluster of k points. The operation interacts nicely with halving edges, so we examine its properties in detail.

  9. Rapid clearance of epigenetic protein reporters from wound edge cells in Drosophila larvae does not depend on the JNK or PDGFR/VEGFR signaling pathways

    OpenAIRE

    Anderson, Aimee E.; Galko, Michael J.

    2014-01-01

    The drastic cellular changes required for epidermal cells to dedifferentiate and become motile during wound closure are accompanied by changes in gene transcription, suggesting corresponding alterations in chromatin. However, the epigenetic changes that underlie wound-induced transcriptional programs remain poorly understood partly because a comprehensive study of epigenetic factor expression during wound healing has not been practical. To determine which chromatin modifying factors might con...

  10. Effect of comprehensive rehabilitation treatment on protrusion of lumbar intervertebral disc%综合康复疗法对腰椎间盘突出症的作用

    Institute of Scientific and Technical Information of China (English)

    陈淑娥

    2003-01-01

    @@ BACKGROUND:Conservative therapy is very important in treatment of lumbar protrusion of lumbar intervertebral disc and symptoms can be alleviated or disappear in most patients by physical therapy,traction and other comprehensive methods.

  11. Cutting edge: identification of the thymic stromal lymphopoietin-responsive dendritic cell subset critical for initiation of type 2 contact hypersensitivity.

    Science.gov (United States)

    Kitajima, Masayuki; Ziegler, Steven F

    2013-11-15

    The cytokine thymic stromal lymphopoietin (TSLP) has been implicated in the initiation and progression of allergic inflammation through its ability to activate dendritic cells (DCs). However, the identity of the DC subset that responds to TSLP is not known. In this study we use a CCL17 reporter strain to identify the TSLP-responsive DC subset. In vitro, TSLP induced CD11b(high) DCs to express CCL17, to increase CCR7-mediated migration activity, and to drive Th2 differentiation of naive CD4 T cells. In vivo, following skin sensitization, we found that a subset of Ag-bearing CCL17(+)CD11b(high) migratory DCs, but not Ag-bearing CCL17(-) migratory DCs, in skin lymph nodes were capable of driving Th2 differentiation and were dramatically reduced in TSLPR-deficient mice. Taken together, these results demonstrate that TSLP activated a subset of CD11b(+) DCs in the skin to produce CCL17, upregulate CCR7, and migrate to the draining lymph node to initiate Th2 differentiation. PMID:24123684

  12. The interplay of cell–cell and cell–substrate adhesion in collective cell migration

    OpenAIRE

    Wang, Chenlu; Chowdhury, Sagar; Driscoll, Meghan; Parent, Carole A.; Gupta, S.K.; Losert, Wolfgang

    2014-01-01

    Collective cell migration often involves notable cell–cell and cell–substrate adhesions and highly coordinated motion of touching cells. We focus on the interplay between cell–substrate adhesion and cell–cell adhesion. We show that the loss of cell-surface contact does not significantly alter the dynamic pattern of protrusions and retractions of fast migrating amoeboid cells (Dictyostelium discoideum), but significantly changes their ability to adhere to other cells. Analysis of the dynamics ...

  13. Randomized clinical trial comparing lumbar percutaneous hydrodiscectomy with lumbar open microdiscectomy for the treatment of lumbar disc protrusions and herniations

    Directory of Open Access Journals (Sweden)

    Alexandre Fogaça Cristante

    2016-05-01

    Full Text Available OBJECTIVES: Hydrodiscectomy is a new technique used for percutaneous spinal discectomy that employs a high-intensity stream of water for herniated disc ablation and tissue aspiration. No previous clinical study has examined the effects of percutaneous hydrodiscectomy. The aim of this study is to evaluate the outcomes of hydrodiscectomy compared to open microdiscectomy regarding pain, function, satisfaction, complications and recurrence rates. METHODS: In this randomized clinical trial, patients referred to our tertiary hospital for lumbar back pain were recruited and included in the study if they had disc protrusion or small herniation in only one level, without neurological deficits and with no resolution after six weeks of conservative treatment. One group underwent open microdiscectomy, and the other group underwent percutaneous microdiscectomy via hydrosurgery. Function was evaluated using the Oswestry Disability Index and pain was assessed using a visual analog scale. Evaluations were performed preoperatively, and then during the first week and at one, three, six and twelve months postoperatively. Personal satisfaction was verified. Clinicaltrials.gov: NCT01367860. RESULTS: During the study period, 20 patients were included in each arm and 39 completed one-year of follow-up (one patient died of unrelated causes. Both groups exhibited equal improvement on the visual analog scale and Oswestry evaluations after treatment, without any significant differences. The improvement in the lumbar visual analog scale score was not significant in the hydrodiscectomy group (p=0.138. The rates of infection, pain, recurrence and satisfaction were similar between the two groups. CONCLUSION: Percutaneous hydrodiscectomy was demonstrated to be as effective as open microdiscectomy for reducing pain. The rates of complications and recurrence of herniation were similar between groups. Patient satisfaction with the treatment was also similar between groups.

  14. Phase geometries of two-dimensional excitable waves govern self-organized morphodynamics of amoeboid cells.

    Science.gov (United States)

    Taniguchi, Daisuke; Ishihara, Shuji; Oonuki, Takehiko; Honda-Kitahara, Mai; Kaneko, Kunihiko; Sawai, Satoshi

    2013-03-26

    In both randomly moving Dictyostelium and mammalian cells, phosphatidylinositol (3,4,5)-trisphosphate and F-actin are known to propagate as waves at the membrane and act to push out the protruding edge. To date, however, the relationship between the wave geometry and the patterns of amoeboid shape change remains elusive. Here, by using phase map analysis, we show that morphology dynamics of randomly moving Dictyostelium discoideum cells can be characterized by the number, topology, and position of spatial phase singularities, i.e., points that represent organizing centers of rotating waves. A single isolated singularity near the cellular edge induced a rotational protrusion, whereas a pair of singularities supported a symmetric extension. These singularities appeared by strong phase resetting due to de novo nucleation at the back of preexisting waves. Analysis of a theoretical model indicated excitability of the system that is governed by positive feedback from phosphatidylinositol (3,4,5)-trisphosphate to PI3-kinase activation, and we showed experimentally that this requires F-actin. Furthermore, by incorporating membrane deformation into the model, we demonstrated that geometries of competing waves explain most of the observed semiperiodic changes in amoeboid morphology. PMID:23479620

  15. Edge magnetization in Bernal-stacked trilayer zigzag graphene nanoribbons

    Science.gov (United States)

    Pérez, Juan Antonio Casao

    2016-06-01

    We have used a tight-binding Hamiltonian of an ABA-stacked trilayer zigzag graphene nanoribbon with β-alignment edges to study the edge magnetizations. Our model includes the effect of the intralayer next-nearest-neighbor hopping, the interlayer hopping responsible for the trigonal warping and the interaction between electrons, which is considered by a single band Hubbard model in the mean field approximation. Firstly, in the neutral system we analyzed the two magnetic states in which both edge magnetizations reach their maximum value; the first one is characterized by an intralayer ferromagnetic coupling between the magnetizations at opposite edges, whereas in the second state that coupling is antiferromagnetic. The band structure, the location of the edge-state bands and the local density of states resolved in spin are calculated in order to understand the origins of the edge magnetizations. We have also introduced an electron doping so that the number of electrons in the ribbon unit cell is higher than in neutral case. As a consequence, we have obtained magnetization steps and charge accumulation at the edges of the sample, which are caused by the edge-state flat bands.

  16. Spin-transfer-torque efficiency enhanced by edge-damage of perpendicular magnetic random access memories

    International Nuclear Information System (INIS)

    We numerically investigate the effect of magnetic and electrical damages at the edge of a perpendicular magnetic random access memory (MRAM) cell on the spin-transfer-torque (STT) efficiency that is defined by the ratio of thermal stability factor to switching current. We find that the switching mode of an edge-damaged cell is different from that of an undamaged cell, which results in a sizable reduction in the switching current. Together with a marginal reduction of the thermal stability factor of an edge-damaged cell, this feature makes the STT efficiency large. Our results suggest that a precise edge control is viable for the optimization of STT-MRAM

  17. Reduction of airfoil trailing edge noise by trailing edge blowing

    International Nuclear Information System (INIS)

    The paper deals with airfoil trailing edge noise and its reduction by trailing edge blowing. A Somers S834 airfoil section which originally was designed for small wind turbines is investigated. To mimic realistic Reynolds numbers the boundary layer is tripped on pressure and suction side. The chordwise position of the blowing slot is varied. The acoustic sources, i.e. the unsteady flow quantities in the turbulent boundary layer in the vicinity of the trailing edge, are quantified for the airfoil without and with trailing edge blowing by means of a large eddy simulation and complementary measurements. Eventually the far field airfoil noise is measured by a two-microphone filtering and correlation and a 40 microphone array technique. Both, LES-prediction and measurements showed that a suitable blowing jet on the airfoil suction side is able to reduce significantly the turbulence intensity and the induced surface pressure fluctuations in the trailing edge region. As a consequence, trailing edge noise associated with a spectral hump around 500 Hz could be reduced by 3 dB. For that a jet velocity of 50% of the free field velocity was sufficient. The most favourable slot position was at 90% chord length

  18. Improved performance of dye sensitized solar cells using Cu-doped TiO2 as photoanode materials: Band edge movement study by spectroelectrochemistry

    Science.gov (United States)

    Zhou, Li; Wei, Liguo; Yang, Yulin; Xia, Xue; Wang, Ping; Yu, Jia; Luan, Tianzhu

    2016-08-01

    Cu-doped TiO2 nanoparticles are prepared and used as semiconductor materials of photoanode to improve the performance of dye sensitized solar cells (DSSCs). UV-Vis spectroscopy and variable temperature spectroelectrochemistry study are used to characterize the influence of copper dopant with different concentrations on the band gap energies of TiO2 nanoparticles. The prepared Cu-doped TiO2 semiconductor has avoided the formation of CuO during hydrothermal process and lowered the conduction band position of TiO2, which contribute to increase the short circuit current density of DSSCs. At the optimum Cu concentration of 1.0 at.%, the short circuit current density increased from 12.54 to 14.98 mA cm-2, full sun solar power conversion efficiencies increased from 5.58% up to 6.71% as compared to the blank DSSC. This showed that the presence of copper in DSSCs leads to improvements of up to 20% in the conversion efficiency of DSSCs.

  19. Fast tracking using edge histograms

    Science.gov (United States)

    Rokita, Przemyslaw

    1997-04-01

    This paper proposes a new algorithm for tracking objects and objects boundaries. This algorithm was developed and applied in a system used for compositing computer generated images and real world video sequences, but can be applied in general in all tracking systems where accuracy and high processing speed are required. The algorithm is based on analysis of histograms obtained by summing along chosen axles pixels of edge segmented images. Edge segmentation is done by spatial convolution using gradient operator. The advantage of such an approach is that it can be performed in real-time using available on the market hardware convolution filters. After edge extraction and histograms computation, respective positions of maximums in edge intensity histograms, in current and previous frame, are compared and matched. Obtained this way information about displacement of histograms maximums, can be directly converted into information about changes of target boundaries positions along chosen axles.

  20. Arsenate reduction and methylation in the cells of Trichoderma asperellum SM-12F1, Penicillium janthinellum SM-12F4, and Fusarium oxysporum CZ-8F1 investigated with X-ray absorption near edge structure

    Energy Technology Data Exchange (ETDEWEB)

    Su, S.M., E-mail: shimingsu@163.com [Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing (China); Zeng, X.B., E-mail: zengxb@ieda.org.cn [Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing (China); Li, L.F.; Duan, R.; Bai, L.Y. [Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing (China); Li, A.G.; Wang, J.; Jiang, S. [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Three fungal strains are capable of As(V) reduction and methylation. Black-Right-Pointing-Pointer As(V) reduction might be more easily processed than the methylation in fungal cells. Black-Right-Pointing-Pointer As sequestration and speciation transformation might be the detoxification processes. - Abstract: Synchrotron radiation-based X-ray absorption near edge structure (XANES) was introduced to directly analysis chemical species of arsenic (As) in the cells of Trichoderma asperellum SM-12F1, Penicillium janthinellum SM-12F4, and Fusarium oxysporum CZ-8F1 capable of As accumulation and volatilisation. After exposure to As(V) of 500 mg L{sup -1} for 15 days, a total of 60.5% and 65.3% of the accumulated As in the cells of T. asperellum SM-12F1 and P. janthinellum SM-12F4, respectively, was As(III), followed by 31.3% and 32.4% DMA (dimethylarsinic acid), 8.3% and 2.3% MMA (monomethylarsonic acid), respectively. However, for F. oxysporum CZ-8F1, 54.5% of the accumulated As was As(III), followed by 37.8% MMA and 7.7% As(V). The reduction and methylation of As(V) formed As(III), MMA, and DMA as the primacy products, and the reduction of As(V) might be more easily processed than the methylation. These results will help to understanding the mechanisms of As detoxification and its future application in bioremediation.

  1. Flatband Engineering of Mobility Edges

    OpenAIRE

    Danieli, Carlo; Bodyfelt, Joshua D.; Flach, Sergej

    2015-01-01

    Properly modulated flatband lattices have a divergent density of states at the flatband energy. Quasiperiodic modulations are known to host a metal insulator transition already in one space dimension. Their embedding into flatband geometries consequently allows for a precise engineering and fine tuning of mobility edges. We obtain analytic expressions for singular mobility edges for two flatband lattice examples. In particular, we engineer cases with arbitrarily small energy separations of mo...

  2. Edge instabilities of topological superconductors

    Science.gov (United States)

    Hofmann, Johannes S.; Assaad, Fakher F.; Schnyder, Andreas P.

    2016-05-01

    Nodal topological superconductors display zero-energy Majorana flat bands at generic edges. The flatness of these edge bands, which is protected by time-reversal and translation symmetry, gives rise to an extensive ground-state degeneracy. Therefore, even arbitrarily weak interactions lead to an instability of the flat-band edge states towards time-reversal and translation-symmetry-broken phases, which lift the ground-state degeneracy. We examine the instabilities of the flat-band edge states of dx y-wave superconductors by performing a mean-field analysis in the Majorana basis of the edge states. The leading instabilities are Majorana mass terms, which correspond to coherent superpositions of particle-particle and particle-hole channels in the fermionic language. We find that attractive interactions induce three different mass terms. One is a coherent superposition of imaginary s -wave pairing and current order, and another combines a charge-density-wave and finite-momentum singlet pairing. Repulsive interactions, on the other hand, lead to ferromagnetism together with spin-triplet pairing at the edge. Our quantum Monte Carlo simulations confirm these findings and demonstrate that these instabilities occur even in the presence of strong quantum fluctuations. We discuss the implications of our results for experiments on cuprate high-temperature superconductors.

  3. Planar Maps in 4 bits/edge

    OpenAIRE

    Curtis, Fred

    2001-01-01

    Existing planar map encodings neglect maps with loops. The presented scheme encodes any connected planar map in 4 bits/edge. Encoding and decoding time is O(edges). Implicit face/edge/vertex orderings and canonical encodings are discussed.

  4. Orientation Relationships between Ferrite and Cementite by Edge-to-edge Matching Principle

    Institute of Scientific and Technical Information of China (English)

    Ning Zhong; Xiaodong Wang; Zhenghong Guo; Yonghua Rong

    2011-01-01

    The crystallographic features of pearlite were investigated by experiments and edge-to-edge matching principle. Two new orientation relationships between ferrite and cementite were determinated by selected area electron diffraction and then explained by our modified edge-to-edge matching method. The consistence of the experimental results with theoretical prediction confirms the practicability of the modified edge-to-edge matching model.

  5. Computation of Edge-Edge-Edge Events Based on Conicoid Theory for 3-D Object Recognition

    Institute of Scientific and Technical Information of China (English)

    WU Chenye; MA Huimin

    2009-01-01

    The availability of a good viewpoint space partition is crucial in three dimensional (3-D) object rec-ognition on the approach of aspect graph. There are two important events depicted by the aspect graph ap-proach, edge-edge-edge (EEE) events and edge-vertex (EV) events. This paper presents an algorithm to compute EEE events by characteristic analysis based on conicoid theory, in contrast to current algorithms that focus too much on EV events and often overlook the importance of EEE events. Also, the paper provides a standard flowchart for the viewpoint space partitioning based on aspect graph theory that makes it suitable for perspective models. The partitioning result best demonstrates the algorithm's efficiency with more valu-able viewpoints found with the help of EEE events, which can definitely help to achieve high recognition rate for 3-D object recognition.

  6. Improved bound on facial parity edge coloring

    OpenAIRE

    Lužar, Borut; Škrekovski, Riste

    2013-01-01

    A facial parity edge coloring of a 2-edge connected plane graph is an edge coloring where no two consecutive edges of a facial walk of any face receive the same color. Additionally, for every face f and every color c either no edge or an odd number of edges incident to f are colored by c. Czap, Jendrol', Kardo\\v{s} and Sotak showed that every 2-edge connected plane graph admits a facial parity edge coloring with at most 20 colors. We improve this bound to 16 colors.

  7. Decay patterns of edge states at reconstructed armchair graphene edges

    Science.gov (United States)

    Park, Changwon; Ihm, Jisoon; Kim, Gunn

    Density functional theory calculations are used to investigate the electronic structures of localized states at reconstructed armchair graphene edges. We consider graphene nanoribbons with two different edge types and obtain the energy band structures and charge densities of the edge states. By examining the imaginary part of the wave vector in the forbidden energy region, we reveal the decay behavior of the wave functions in graphene. The complex band structures of graphene in the armchair and zigzag directions are presented in the first-principles framework. G.K. acknowledges the support of the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education (Grant No. 2013R1A1A2009131) and the Priority Research Center Program (Grant No. 2010-0020207).

  8. Actin based processes that could determine the cytoplasmic architecture of plant cells

    NARCIS (Netherlands)

    Honing, van der H.S.; Emons, A.M.C.; Ketelaar, M.J.

    2007-01-01

    Actin polymerisation can generate forces that are necessary for cell movement, such as the propulsion of a class of bacteria, including Listeria, and the protrusion of migrating animal cells. Force generation by the actin cytoskeleton in plant cells has not been studied. One process in plant cells t

  9. On the edge: haptic discrimination of edge sharpness.

    Directory of Open Access Journals (Sweden)

    Andy L Skinner

    Full Text Available The increasing ubiquity of haptic displays (e.g., smart phones and tablets necessitates a better understanding of the perceptual capabilities of the human haptic system. Haptic displays will soon be capable of locally deforming to create simple 3D shapes. This study investigated the sensitivity of our haptic system to a fundamental component of shapes: edges. A novel set of eight high quality shape stimuli with test edges that varied in sharpness were fabricated in a 3D printer. In a two alternative, forced choice task, blindfolded participants were presented with two of these shapes side by side (one the reference, the other selected randomly from the remaining set of seven and after actively exploring the test edge of each shape with the tip of their index finger, reported which shape had the sharper edge. We used a model selection approach to fit optimal psychometric functions to performance data, and from these obtained just noticeable differences and Weber fractions. In Experiment 1, participants performed the task with four different references. With sharpness defined as the angle at which one surface meets the horizontal plane, the four JNDs closely followed Weber's Law, giving a Weber fraction of 0.11. Comparisons to previously reported Weber fractions from other haptic manipulations (e.g. amplitude of vibration suggests we are sufficiently sensitive to changes in edge sharpness for this to be of potential utility in the design of future haptic displays. In Experiment 2, two groups of participants performed the task with a single reference but different exploration strategies; one was limited to a single touch, the other unconstrained and free to explore as they wished. As predicted, the JND in the free exploration condition was lower than that in the single touch condition, indicating exploration strategy affects sensitivity to edge sharpness.

  10. Edge-injective and edge-surjective vertex labellings

    DEFF Research Database (Denmark)

    Brandt, Stephan; Rautenbach, D.; Regen, F.;

    2010-01-01

    For a graph G = (V, E) we consider vertex-k-labellings f : V → {1,2, ,k} for which the induced edge weighting w : E → {2, 3,., 2k} with w(uv) = f(u) + f(v) is injective or surjective or both. We study the relation between these labellings and the number theoretic notions of an additive basis and a...... recent conjecture of Ivančo and Jendroł concerning edge-irregular total labellings for graphs that are sparse enough. © 2010 Societ y for Industrial and Applied Mathematics....

  11. Edges and Corners With Shearlets.

    Science.gov (United States)

    Duval-Poo, Miguel A; Odone, Francesca; De Vito, Ernesto

    2015-11-01

    Shearlets are a relatively new and very effective multi-scale framework for signal analysis. Contrary to the traditional wavelets, shearlets are capable to efficiently capture the anisotropic information in multivariate problem classes. Therefore, shearlets can be seen as the valid choice for multi-scale analysis and detection of directional sensitive visual features like edges and corners. In this paper, we start by reviewing the main properties of shearlets that are important for edge and corner detection. Then, we study algorithms for multi-scale edge and corner detection based on the shearlet representation. We provide an extensive experimental assessment on benchmark data sets which empirically confirms the potential of shearlets feature detection. PMID:26353351

  12. Edge Double-Critical Graphs

    Directory of Open Access Journals (Sweden)

    John J. Lattanzio

    2010-01-01

    Full Text Available Problem statement: The vertex double-critical conjecture that the only vertex double-critical graph is the complete graph has remained unresolved for over forty years. The edge analogue of this conjecture has been proved. Approach: It was observed that if the chromatic number decreases by two upon the removal of a 2-matching, then the 2-matching comprises four vertices which determine an induced subgraph isomorphic to the complete graph on four vertices. This observation was generalized to t-matchings. Results: In this note, it has been shown that the only edge double-critical graph is the complete graph. Conclusion/Recommendations: An alternate proof that the only edge double-critical graph is the complete graph has been obtained. Moreover, the result has been obtained independently.

  13. Continued Growth on Graphene Edges

    Science.gov (United States)

    Luo, Zhengtang

    Previously, we have shown that the large-size single crystal graphene can be obtained by suppressing the nucleation density during Chemical Vapor Deposition (CVD) growth. Here we demonstrate that the graphene single crystal can be amplified by a continued growth method. In this process, we used a mild oxidation step after the first-growth, which lead to the observed fromation of oxides at the vicinity of graphene edges, which allows the graphene growth at seed edges due to reduced activation energy. Consequently, we successful grown a secondary single-crystal graphene structures with the same lattice structure, orientation on the graphene edges. This amplification method would enable the production of graphene electronics with controlled properties.

  14. All-graphene edge contacts

    DEFF Research Database (Denmark)

    Jacobsen, Kåre Wedel; Falkenberg, Jesper Toft; Papior, Nick Rübner;

    2016-01-01

    Using ab-initio methods we investigate the possibility of three-terminalgraphene "T-junction" devices and show that these all-graphene edge contactsare energetically feasible when the 1D interface itself is free from foreignatoms. We examine the energetics of various junction structures as a...... therange of 1-10 kΩμm which is comparable to the best contact resistance reportedfor edge-contacted graphene-metal contacts. We conclude that conductingall-carbon T-junctions should be feasible....

  15. The knife-edge chamber

    International Nuclear Information System (INIS)

    In this paper the design for a new technology for particle track detectors is described. Using standard IC fabrication techniques, a pattern of microscopic knife edges and field-shaping electrodes can be fabricated on a silicon substrate. The knife-edge chamber uniquely offers attractive performance for the track chambers required for SSC detectors, for which no present technology is yet satisfactory. Its features include: excellent radiation hardness (10 Mrad), excellent spatial resolution (∼20 μm), short drift time (20 ns), and large pulse height (1 mV)

  16. Geometric phase at graphene edge

    OpenAIRE

    Choi, Sang-Jun; Park, Sunghun; Sim, H. -S.

    2014-01-01

    We study the scattering phase shift of Dirac fermions at graphene edge. We find that when a plane wave of a Dirac fermion is reflected at an edge of graphene, its reflection phase is shifted by the geometric phase resulting from the change of the pseudospin of the Dirac fermion in the reflection. The geometric phase is the Pancharatnam-Berry phase that equals the half of the solid angle on Bloch sphere determined by the propagation direction of the incident wave and also by the orientation an...

  17. Direct laser writing of nanorough cell microbarriers on anatase/Si and graphite/Si.

    Science.gov (United States)

    Xiang, Y C; Martínez-Martínez, R M; Torres-Costa, V; Agulló-Rueda, F; García-Ruiz, J P; Manso-Silván, M

    2016-09-01

    The formation of hierarchical structures consisting of microstripe barriers decorated with nanorough ablated materials prepared by direct laser writing is described. Linear features of circa 25μm width and 12μm height are achieved on amorphous and crystalline titania and graphitic carbon films deposited on silicon. Ablated protrusions build up barriers decorated by nanoscale Si-film reconstructions, as indicated by EDX maps and micro-Raman spectroscopy. Wettability tests show a dramatic change in water contact angle, which leads to almost full wetting after irradiation, irrespective of the original film composition. Fluorescence microscopy images of human mesenchymal stem cells cultured on 1D and 2D structures demonstrate the short term biocompatibility of the ablated surfaces. It is shown that cells adhere, extend and polarize on feature edges, independently of the type of surface, thus suggesting that the created nanoroughness is at the origin of the antifouling behavior. In particular, irradiated anatase and graphite surfaces demonstrate an increased performance of crystalline films for the creation of cell guiding and trapping devices. The results suggest that such laser processing of films may serve as a time-and-cost-efficient method for the design of few-cells analytical surfaces. PMID:27207033

  18. Edge shape and comfort of rigid lenses.

    Science.gov (United States)

    La Hood, D

    1988-08-01

    One of the main factors determining the comfort of a rigid contact lens is the shape of the edge. The comfort of four different contact lens edge shapes was assessed with four unadapted subjects in a randomized masked trial. Lenses with well rounded anterior edge profiles were found to be significantly more comfortable than lenses with square anterior edges. There was no significant difference in subjective comfort between a rounded and square posterior edge profile. The results suggest that the interaction of the edge with the eyelid is more important in determining comfort than edge effects on the cornea, when lenses are fitted according to a corneal alignment philosophy. PMID:3177585

  19. The effect of undulating leading-edge modifications on NACA 0021 airfoil characteristics

    Science.gov (United States)

    Rostamzadeh, N.; Kelso, R. M.; Dally, B. B.; Hansen, K. L.

    2013-11-01

    In spite of its mammoth physical size, the humpback whale's manoeuvrability in hunting has captured the attention of biologists as well as fluid mechanists. It has now been established that the protrusions on the leading-edges of the humpback's pectoral flippers, known as tubercles, account for this species' agility and manoeuvrability. In the present work, Prandtl's nonlinear lifting-line theory was employed to propose a hypothesis that the favourable traits observed in the performance of tubercled lifting bodies are not exclusive to this form of leading-edge configuration. Accordingly, a novel alternative to tubercles was introduced and incorporated into the design of four airfoils that underwent wind tunnel force and pressure measurement tests in the transitional flow regime. In addition, a Computation Fluid Dynamics study was performed using the Shear Stress Transport transitional model in the context of unsteady Reynolds-Averaged Navier-Stokes at several attack angles. The results from the numerical investigation are in reasonable agreement with those of the experiments, and suggest the presence of features that are also observed in flows over tubercled foils, most notably a distinct pair of streamwise vortices for each wavelength of the tubercle-like feature.

  20. Design and Simulation of Canny Edge Detection

    OpenAIRE

    D Narayana Reddy*; Vaijanath V.Yerigeri; Harish Sanu

    2014-01-01

    Edge is one of the prominent features in the image processing applications. The edge detection algorithm is carried out by using different methods. Canny edge algorithm is one of the well known edge detection algorithm. In proposed design, the canny edge detection algorithm is designed in verilog and simulated using the MATLAB and Modelsim. The input image is converted to text/pixel values using MATLAB and is stored in a new text file. Verilog with test bench program is used to as...

  1. Color Image Interpolation using Optimal Edge Detector

    OpenAIRE

    R. Jansi; Asnath Victy Phamila; Amutha, R.

    2013-01-01

    This paper proposes an efficient image interpolation algorithm using optimal edge detector. The proposed interpolation algorithm is done in two steps. In the first step, the missing pixels with diagonal neighbors are interpolated and in the second step, the missing pixels with axial neighbors are interpolated. In both the steps classification of edge and smooth pixels is performed using canny edge detector. For the pixels classified as edge pixels, the direction of the edge is found using var...

  2. At the edge of intonation

    DEFF Research Database (Denmark)

    Niebuhr, Oliver

    2012-01-01

    The paper is concerned with the 'edge of intonation' in a twofold sense. It focuses on utterance-final F0 movements and crosses the traditional segment-prosody divide by investigating the interplay of F0 and voiceless fricatives in speech production. An experiment was performed for German with fo...

  3. Edge classification for color constancy

    NARCIS (Netherlands)

    A. Gijsenij; T. Gevers; J. van de Weijer

    2008-01-01

    The goal of color constancy is to measure image colors despite differences in the color of the light source. Traditionally, the computational method of obtaining this ability is by using pixel values only. Recently, methods using edges instead of pixel values have been proposed. However, different e

  4. The Problem of the Edge.

    Science.gov (United States)

    Faatz, Judith A.

    1998-01-01

    Describes a field study in a local ecosystem which allows high school students to investigate the edge effect, where a meadow and a forest meet. Students measure soil moisture content, soil temperature, air temperature, relative humidity, wind intensity, and illumination level. Teachers can help students apply their findings to understand problems…

  5. Vertices of degree k in edge-minimal, k-edge-connected graphs

    OpenAIRE

    Kingsford, Carl; Marçais, Guillaume

    2009-01-01

    Halin showed that every edge minimal, k-vertex connected graph has a vertex of degree k. In this note, we prove the analogue to Halin's theorem for edge-minimal, k-edge-connected graphs. We show there are two vertices of degree k in every edge-minimal, k-edge-connected graph.

  6. Development of edge effects around experimental ecosystem hotspots is affected by edge density and matrix type

    Science.gov (United States)

    Ecological edge effects are sensitive to landscape context. In particular, edge effects can be altered by matrix type and by the presence of other nearby edges. We experimentally altered patch configurations in an African savanna to determine how edge density and matrix type influence edge effect de...

  7. High glucose-mediated oxidative stress impairs cell migration.

    Directory of Open Access Journals (Sweden)

    Marcelo L Lamers

    Full Text Available Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we evaluate the hypothesis that high glucose concentrations inhibit cell migration. Using CHO.K1 cells, NIH-3T3 fibroblasts, mouse embryonic fibroblasts and primary skin fibroblasts from control and diabetic rats cultured in 5 mM D-glucose (low glucose, LG, 25 mM D-glucose (high glucose, HG or 25 mM L-glucose medium (osmotic control--OC, we analyzed the migration speed, protrusion stability, cell polarity, adhesion maturation and the activity of the small Rho GTPase Rac1. We also analyzed the effects of reactive oxygen species by incubating cells with the antioxidant N-Acetyl-Cysteine (NAC. We observed that HG conditions inhibited cell migration when compared to LG or OC. This inhibition resulted from impaired cell polarity, protrusion destabilization and inhibition of adhesion maturation. Conversely, Rac1 activity, which promotes protrusion and blocks adhesion maturation, was increased in HG conditions, thus providing a mechanistic basis for the HG phenotype. Most of the HG effects were partially or completely rescued by treatment with NAC. These findings demonstrate that HG impairs cell migration due to an increase in oxidative stress that causes polarity loss, deficient adhesion and protrusion. These alterations arise, in large part, from increased Rac1 activity and may contribute to the poor wound healing observed in diabetic patients.

  8. Cell invasion through basement membrane

    OpenAIRE

    Morrissey, Meghan A; Hagedorn, Elliott J.; Sherwood, David R.

    2013-01-01

    Cell invasion through basement membrane is an essential part of normal development and physiology, and occurs during the pathological progression of human inflammatory diseases and cancer. F-actin-rich membrane protrusions, called invadopodia, have been hypothesized to be the “drill bits” of invasive cells, mediating invasion through the dense, highly cross-linked basement membrane matrix. Though studied in vitro for over 30 y, invadopodia function in vivo has remained elusive. We have recent...

  9. The nanostructure of myoendothelial junctions contributes to signal rectification between endothelial and vascular smooth muscle cells

    DEFF Research Database (Denmark)

    Brasen, Jens Christian; Jacobsen, Jens Christian Brings; von Holstein-Rathlou, Niels-Henrik

    2012-01-01

    can easily drive a concentration change in the head of the myoendothelial protrusion. Subsequently the signal can be amplified in the head, and activate the entire cell. In contrast, a signal in the cell from which the myoendothelial junction originates will be attenuated and delayed in the neck...... region as it travels into the head of the myoendothelial junction and the neighboring cell....

  10. Edge detection based on directional space

    Institute of Scientific and Technical Information of China (English)

    YUAN Wei-qi; LI De-sheng

    2006-01-01

    A new method for edge detection based on directional space is proposed.The principle is that:firstly,the directional differential space is set up in which the ridge edge pixels and valley edge pixels are abstracted with the help of the method of logical judgments along the direction of differential function,forming a directional roof edge map;secondly,step edge pixels are abstracted between the neighboring directional ridge edge and directional valley edge along the direction of differential function;finally,the ridge edge map,valley edge map and step edge map gained along different directions are combined into corresponding ridge edge map,valley edge map and step edge map.This method is different from classical algorithms in which the gray differential values of the mutual vertical direction are combined into one gradient value.The experiment of edge detection is made for the images of nature scenery,human body and accumulative raw material,whose result is compared with the one of classical algorithms and showing the robustness of the proposed method.

  11. Rac function is crucial for cell migration but is not required for spreading and focal adhesion formation

    DEFF Research Database (Denmark)

    Steffen, Anika; Ladwein, Markus; Dimchev, Georgi A;

    2013-01-01

    Cell migration is commonly accompanied by protrusion of membrane ruffles and lamellipodia. In two-dimensional migration, protrusion of these thin sheets of cytoplasm is considered relevant to both exploration of new space and initiation of nascent adhesion to the substratum. Lamellipodium formation...... restored by expression of either Rac subfamily member, but not by Cdc42 or RhoG. Cells deficient in Rac showed strong reduction in wound closure and random cell migration and a notable loss of sensitivity to a chemotactic gradient. Despite these defects, Rac-deficient cells were able to spread, formed...... deficiency increased the mobility of different components in focal adhesions, potentially explaining how Rac - although not essential - can contribute to focal adhesion assembly. Together, our data demonstrate that Rac signaling is essential for lamellipodium protrusion and for efficient cell migration, but...

  12. Edge ambipolar potential in toroidal fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Spizzo, G., E-mail: gianluca.spizzo@igi.cnr.it; Vianello, N.; Agostini, M.; Puiatti, M. E.; Scarin, P.; Spolaore, M.; Terranova, D. [Consorzio RFX, Euratom-ENEA Association and Istituto Gas Ionizzati del CNR, Corso Stati Uniti, 4 35127 Padova (Italy); White, R. B. [Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543 (United States); Abdullaev, S. S.; Schmitz, O. [Institut für Energieforschung-Plasmaphysik, Association EURATOM-FZJ, Jülich (Germany); Cavazzana, R. [Consorzio RFX, Euratom-ENEA Association, Corso Stati Uniti, 4 35127 Padova (Italy); Ciaccio, G. [Dipartimento di Fisica, Università degli studi di Padova, Padova (Italy)

    2014-05-15

    A series of issues with toroidally confined fusion plasmas are related to the generation of 3D flow patterns by means of edge magnetic islands, embedded in a chaotic field and interacting with the wall. These issues include the Greenwald limit in Tokamaks and reversed-field pinches, the collisionality window for ELM mitigation with the resonant magnetic perturbations (RMPs) in Tokamaks, and edge islands interacting with the bootstrap current in stellarators. Measurements of the 2D map of the edge electric field E{sup r}(r=a,θ,ϕ) in the RFX reversed-field pinch show that E{sup r} has the same helicity of the magnetic islands generated by a m/n perturbation: in fact, defining the helical angle u=mθ−nϕ+ωt, maps show a sinusoidal dependence as a function of u, E{sup r}=E{sup ~r}sin u. The associated E × B flow displays a huge convective cell with v(a)≠0 which, in RFX and near the Greenwald limit, determines a stagnation point for density and a reversal of the sign of E{sup r}. From a theoretical point of view, the question is how a perturbed toroidal flux of symmetry m/n gives rise to an ambipolar potential Φ=Φ{sup ~}sin u. On the basis of a model developed with the guiding center code ORBIT and applied to RFX and the TEXTOR tokamak, we will show that the presence of an m/n perturbation in any kind of device breaks the toroidal symmetry with a drift proportional to the gyroradius ρ, thus larger for ions (ρ{sub i} ≫ ρ{sub e}). Immediately, an ambipolar potential arises to balance the drifts, with the same symmetry as the original perturbation.

  13. Edge-on thick discs

    Science.gov (United States)

    Kasparova, A.; Katkov, I.; Chilingarian, I.; Silchenko, O.; Moiseev, A.; Borisov, S.

    2016-06-01

    Although thick stellar discs are detected in nearly all edge-on disc galaxies, their formation scenarios still remain a matter of debate. Due to observational difficulties, there is a lack of information about their stellar populations. Using the Russian 6-m telescope BTA we collected deep spectra of thick discs in three edge-on early-type disc galaxies located in different environments: NGC4111 in a dense group, NGC4710 in the Virgo cluster, and NGC5422 in a sparse group. We see intermediate age (4 ‑ 5 Gyr) metal rich ([Fe/H] ~ ‑0.2 ‑ 0.0 dex) stellar populations in NGC4111 and NGC4710. On the other hand, NGC5422 does not harbour young stars, its only disc is thick and old (10 Gyr) and its α-element abundance suggests a long formation epoch implying its formation at high redshift. Our results prove the diversity of thick disc formation scenarios.

  14. EDGE-ORIENTED HEXAGONAL ELEMENTS

    Institute of Scientific and Technical Information of China (English)

    Chao Yang; Jiachang Sun

    2007-01-01

    In this paper, two new nonconforming hexagonal elements are presented, which are based on the trilinear function space Q(3)1 and are edge-oriented, analogical to the case of the rotated Q1 quadrilateral element. A priori error estimates are given to show that the new elements achieve first-order accuracy in the energy norm and second-order accuracy in the L2 norm. This theoretical result is confirmed by the numerical tests.

  15. Edge effects and delamination failures

    Science.gov (United States)

    Herakovich, C. T.

    1989-01-01

    The fundamental relationship between the morphology of a composite laminate and the resulting free edge effects is explored and related to delamination failures. Cross-ply, angle-ply, and quasi-isotropic laminates are discussed in detail. It is shown that the local mismatch in elastic properties of adjacent layers and the global stacking sequence of a laminate both have a significant influence on the interlaminar stresses and delamination failures.

  16. Molecular dynamics simulation of an edge dislocation slipping on a cubic plane of Ni3Al

    International Nuclear Information System (INIS)

    The motion mechanism of an edge dislocation on a cubic plane of Ni3Al is studied in periodic simulation cells subjected to applied shear stress. The simulation results show that the motion of the edge dislocation is controlled by the complex Lomer–Cottrell lock mechanism. Using this locking–unlocking mechanism, we have given a perfect explanation to the very jerky motion of the edge dislocation, which has been experimentally observed for about 20 years

  17. Edge-driven microplate kinematics

    Science.gov (United States)

    Schouten, Hans; Klitgord, Kim D.; Gallo, David G.

    1993-01-01

    It is known from plate tectonic reconstructions that oceanic microplates undergo rapid rotation about a vertical axis and that the instantaneous rotation axes describing the microplate's motion relative to the bounding major plates are frequently located close to its margins with those plates, close to the tips of propagating rifts. We propose a class of edge-driven block models to illustrate how slip across the microplate margins, block rotation, and propagation of rifting may be related to the relative motion of the plates on either side. An important feature of these edge-driven models is that the instantaneous rotation axes are always located on the margins between block and two bounding plates. According to those models the pseudofaults or traces of disrupted seafloor resulting from the propagation of rifting between microplate and major plates may be used independently to approximately trace the continuous kinematic evolution of the microplate back in time. Pseudofault geometries and matching rotations of the Easter microplate show that for most of its 5 m.y. history, block rotation could be driven by the drag of the Nazca and Pacific plates on the microplate's edges rather than by a shear flow of mantle underneath.

  18. Leading Edge Device Aerodynamic Optimization

    Directory of Open Access Journals (Sweden)

    Marius Gabriel COJOCARU

    2015-12-01

    Full Text Available Leading edge devices are conventionally used as aerodynamic devices that enhance performances during landing and in some cases during takeoff. The need to increase the efficiency of the aircrafts has brought the idea of maintaining as much as possible a laminar flow over the wings. This is possible only when the leading edge of the wings is free from contamination, therefore using the leading edge devices with the additional role of shielding during takeoff. Such a device based on the Krueger flap design is aerodynamically analyzed and optimized. The optimization comprises three steps: first, the positioning of the flap such that the shielding criterion is kept, second, the analysis of the flap size and third, the optimization of the flap shape. The first step is subject of a gradient based optimization process of the position described by two parameters, the position along the line and the deflection angle. For the third step the Adjoint method is used to gain insight on the shape of the Krueger flap that will extend the most the stall limit. All these steps have been numerically performed using Ansys Fluent and the results are presented for the optimized shape in comparison with the baseline configuration.

  19. Nonreference Medical Image Edge Map Measure

    Directory of Open Access Journals (Sweden)

    Karen Panetta

    2014-01-01

    Full Text Available Edge detection is a key step in medical image processing. It is widely used to extract features, perform segmentation, and further assist in diagnosis. A poor quality edge map can result in false alarms and misses in cancer detection algorithms. Therefore, it is necessary to have a reliable edge measure to assist in selecting the optimal edge map. Existing reference based edge measures require a ground truth edge map to evaluate the similarity between the generated edge map and the ground truth. However, the ground truth images are not available for medical images. Therefore, a nonreference edge measure is ideal for medical image processing applications. In this paper, a nonreference reconstruction based edge map evaluation (NREM is proposed. The theoretical basis is that a good edge map keeps the structure and details of the original image thus would yield a good reconstructed image. The NREM is based on comparing the similarity between the reconstructed image with the original image using this concept. The edge measure is used for selecting the optimal edge detection algorithm and optimal parameters for the algorithm. Experimental results show that the quantitative evaluations given by the edge measure have good correlations with human visual analysis.

  20. Fascin Rigidity and L-plastin Flexibility Cooperate in Cancer Cell Invadopodia and Filopodia.

    Science.gov (United States)

    Van Audenhove, Isabel; Denert, Majken; Boucherie, Ciska; Pieters, Leen; Cornelissen, Maria; Gettemans, Jan

    2016-04-22

    Invadopodia and filopodia are dynamic, actin-based protrusions contributing to cancer cell migration, invasion, and metastasis. The force of actin bundles is essential for their protrusive activity. The bundling protein fascin is known to play a role in both invadopodia and filopodia. As it is more and more acknowledged that functionally related proteins cooperate, it is unlikely that only fascin bundles actin in these protrusions. Another interesting candidate is L-plastin, normally expressed in hematopoietic cells, but considered a common marker of many cancer types. We identified L-plastin as a new component of invadopodia, where it contributes to degradation and invasiveness. By means of specific, high-affinity nanobodies inhibiting bundling of fascin or L-plastin, we further unraveled their cooperative mode of action. We show that the bundlers cannot compensate for each other due to strikingly different bundling characteristics: L-plastin bundles are much thinner and less tightly packed. Composite bundles adopt an intermediate phenotype, with fascin delivering the rigidity and strength for protrusive force and structural stability, whereas L-plastin accounts for the flexibility needed for elongation. Consistent with this, elevated L-plastin expression promotes elongation and reduces protrusion density in cells with relatively lower L-plastin than fascin levels. PMID:26945069

  1. Effect of shear stress on the expression of growth factors in endothelial cells around stent edge%切应力对支架边缘内皮细胞生长因子表达的影响

    Institute of Scientific and Technical Information of China (English)

    王安才; 李利芳; 张步春; 白玲

    2007-01-01

    增生的原因之一.%BACKGROUND:Alterations in secondary hemodynamics around the stent edge can be caused by stent planted. Is there different effect of shear stress on platelet growth factors-A, B (PDGF-A, B) and basic fibroblast growth factor (bFGF) of endothelial cells around stent edge after stent planted?OBJECTIVE: To explore the effect of shear stress on growth factors of endothelial cells around stent edge.DESIGN: Observational comparative study.SETTING: Department of Cardiology, Yijishan Hospital, Wannan Medical College; Laboratory of Biomechanics (National Laboratory), Medical College of Shanghai Jiao Tong University.MATERIALS: The experiment was carried out in the Laboratory of Biomechanics, Medical College of Shanghai Jiaotong University from April to October 2006. The main reagents were detailed as follows: trypsin (Hyclon Company); M-199 medium (Gibco BRL Company); fetal bovine serum (Hangzhou Sijiqing Bioengineering Material Institute); aFGF, Heparin and Hepes (Sigma Company); thymide, Ⅷ factor monoclonal antibody (Rabbit anti-human),biotinylated horse anti-rabbit IgG and propidium lodide (Sigma Company); neonate belly band (Delivery Room of Shanghai the Fifth People's Hospital); trizol (Invitrogene Company); reverse transcription polymerase chain reaction (RT-PCR) kit (Fermentas Company); penicillin/streptomycin (AB/M), objective gene primer (Shanghai Bioengineering Company).METHODS: Traditional parallel-plate streaming cavity was modified into rectangular and gradient shear stress models;while static group was established at the same time. Two shear stress groups were subjected to 11.37 dyne/cm2 and 5.66-14.38 dyne/cm2 shear stress, respectively for 3 hours, 6 hours and 12 hours.MAIN OUTCOME MEASURES: The expressions of PDGF-A, B and bFGF mRNA of human umbilical endothelial cells (HUVECs) were measured by RT-PCR at different time points.RESULTS: Compared with static group, the maximal expression of PDGF-A, B and bFGF mRNA was reached peak at 3 hours in gradient shear stress group and this

  2. Edge plasma studies on the CASTOR tokamak

    International Nuclear Information System (INIS)

    as a formation of convective cells around the biased flux tube. In the edge plasma, the biasing causes a clear and reproducible transition to improved confinement, along with the formation of an edge transport barrier which is characterized by (i) a steepening of the time-averaged density gradient (ii) a reduction in recycling (iii) a substantial improvement of the global particle confinement. A creation of a strongly sheared radial electric field within the transport barrier is followed by an abrupt collapse of the potential and density gradients. The observed radial propagation of density structures and fast spikes of electron temperature immediately following the collapse indicate the ejection of hot dense plasma towards the wall. This process repeats with a frequency of about 10 kHz throughout the full biasing phase of the discharge. The diagnostic set allows us to verify that radial the momentum balance equation is respected during the collapse of the transport barrier. (author)

  3. Environmental Dataset Gateway (EDG) REST Interface

    Data.gov (United States)

    U.S. Environmental Protection Agency — Use the Environmental Dataset Gateway (EDG) to find and access EPA's environmental resources. Many options are available for easily reusing EDG content in other...

  4. A Fuzzy Set Approach for Edge Detection

    Directory of Open Access Journals (Sweden)

    Pushpajit A. Khaire

    2012-12-01

    Full Text Available Image segmentation is one of the most studied problems in image analysis, computer vision, pattern recognition etc. Edge detection is a discontinuity based approach used for image segmentation. In this paper, an edge detection using fuzzy set is proposed, where an image is considered as a fuzzy set and pixels are taken as elements of fuzzy set. The fuzzy approach converts the color image to a partially segmented image; finally an edge detector is convolved over the partially segmented image to obtain an edged image. The approach is implemented using MATLAB 7.11. (R2010b. For qualitative and quantitative comparison, BSD (Berkeley Segmentation Database images are used for experimentation. Performance parameters used are PSNR (dB and Performance ratio (PR of true to false edges. It has been shown that the proposed approach performs better than Canny’s edge detection algorithm under almost all scenarios. The proposed approach reduces false edge detection and double edges.

  5. Chemistry at the Edge of Graphene.

    Science.gov (United States)

    Bellunato, Amedeo; Arjmandi Tash, Hadi; Cesa, Yanina; Schneider, Grégory F

    2016-03-16

    The selective functionalization of graphene edges is driven by the chemical reactivity of its carbon atoms. The chemical reactivity of an edge, as an interruption of the honeycomb lattice of graphene, differs from the relative inertness of the basal plane. In fact, the unsaturation of the pz orbitals and the break of the π conjugation on an edge increase the energy of the electrons at the edge sites, leading to specific chemical reactivity and electronic properties. Given the relevance of the chemistry at the edges in many aspects of graphene, the present Review investigates the processes and mechanisms that drive the chemical functionalization of graphene at the edges. Emphasis is given to the selective chemical functionalization of graphene edges from theoretical and experimental perspectives, with a particular focus on the characterization tools available to investigate the chemistry of graphene at the edge. PMID:26693841

  6. Evaluation of edge detectors using avarage risk

    NARCIS (Netherlands)

    Spreeuwers, L.J.; Heijden, van der F.

    1992-01-01

    A new method for evaluation of edge detectors, based on the average risk of a decision, is discussed. The average risk is a performance measure well-known in Bayesian decision theory. Since edge detection can be regarded as a compound decision making process, the performance of an edge detector is

  7. Edge and coupled core-edge transport modelling in tokamaks

    International Nuclear Information System (INIS)

    Recent advances in the theory and modelling of tokamak edge, scrape-off-layer (SOL) and divertor plasmas are described. The effects of the poloidal ExB drift on inner/outer divertor-plate asymmetries within a 1D analysis are shown to be in good agreement with experimental trends; above a critical v ExB, the model predicts transitions to supersonic SOL flow at the inboard midplane. 2D simulations show the importance of ExB flow in the private-flux region and of ∇ B-drifts. A theory of rough plasma-facing surfaces is given, predicting modifications to the SOL plasma. The parametric dependence of detached-plasma states in slab geometry has been explored; with sufficient pumping, the location of the ionization front can be controlled; otherwise only fronts near the plate or the X-point are stable. Studies with a more accurate Monte-Carlo neutrals model and a detailed non-LTE radiation-transport code indicate various effects are important for quantitative modelling. Detailed simulations of the DIII-D core and edge are presented; impurity and plasma flow are discussed and shown to be well modelled with UEDGE. (author)

  8. K-edge densitometer (KED)

    Energy Technology Data Exchange (ETDEWEB)

    Sprinkle, J.K.; Hansen, W.J.

    1993-02-11

    In 1979, a K-edge densitometer (KED) was installed by the Safeguards Assay group from Los Alamos National Laboratory in the PNC reprocessing plant at Tokai-mura, Japan. It uses an active nondestructive assay technique, KED, to measure the plutonium concentration of the product solution. The measurement uncertainty of an assay depends on the count time chosen, but can be 0.5% or better. The computer hardware and software were upgraded in 1992. This manual describes the operation of the instrument, with an emphasis on the user interface to the software.

  9. Instant Adobe Edge Inspect starter

    CERN Document Server

    Khan, Joseph

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. This easy-to-understand Starter guide will get you up to speed with Adobe Edge Inspect quickly and with little effort.This book is for frontend web developers and designers who are developing and testing web applications targeted for mobile browsers. It's assumed that you have a basic understanding of creating web applications using HTML, CSS, and JavaScript, as well as being familiar with running web pages from local HTTP servers. Readers are a

  10. Anterior approach on protrusion of intervertebral disc and early rehabilitation training after operation%颈椎间盘突出症的前路手术与术后早期康复训练

    Institute of Scientific and Technical Information of China (English)

    方军; 高克海; 李华壮; 褚俊良

    2002-01-01

    Backgroud: The main causes of protrusion of cervical intervertebral disc are degenerations such as osteophymas on degenerated protruded intervertebral disc and vertebral body anterior to vertebral canal. Decompression via cervical anterior approach and fusion of implanted bone are effective methods. And it is very important for surgical effect and functional restoration to make sufficient preoperative preparation and consummate postoperative rehabilitation.

  11. Combination of physical therapies on 80 cases of protrusion of lumbar intervertebral discs%不同物理疗法组合治疗腰椎间盘突出症80例

    Institute of Scientific and Technical Information of China (English)

    贾继娥; 张晓莉

    2003-01-01

    @@ BACKGROUND: Therapy of protrusion of lumbar intervertebral discs includes drugs, operation, compared with other two methods, physical therapy is safe, high effective and economical. Physical therapy included ultrashort wave, computer middle-frequency electrical therapy, warm magnet therapy, combination of these 3 methods needs a further explore.

  12. 老年性腰椎间盘突出症的诊断及早期康复体会%Experience of diagnosis and early rehabilitation of senile protrusion of lumbar intervertebral disc

    Institute of Scientific and Technical Information of China (English)

    赫明堂; 刁庆勋

    2003-01-01

    @@ INTRODUCTION Senile protrusion of lumbar intervertebral disc has many difference compared with the middle-aged and younger at etiology, pathological change, symptom, sign, image change, diagnosis and treatment, which character is: no traumatic history, long disease course, untypical symptom and sign, many complications, bad body quantity and complicated treatment.

  13. Edge impact modeling on stiffened composite structures

    OpenAIRE

    Ostré, Benjamin; Bouvet, Christophe; Minot, Clément; Aboissière, Jacky

    2015-01-01

    Finite Element Analysis of low velocity/low energy edge impact has been carried out on carbon fiber reinforced plastic structure. Edge impact experimental results were then compared to the numerical ‘‘Discrete Ply Model’’ in order to simulate the edge impact damage. This edge impact model is inspired to out-of-plan impact model on a laminate plate with addition of new friction and crushing behaviors. From a qualitative and quantitative point of view, this edge impact model reveals a relati...

  14. Image edge detection based on beamlet transform

    Institute of Scientific and Technical Information of China (English)

    Li Jing; Huang Peikang; Wang Xiaohu; Pan Xudong

    2009-01-01

    Combining beamlet transform with steerable filters, a new edge detection method based on line gra-dient is proposed. Compared with operators based on point local properties, the edge-detection results with this method achieve higher SNR and position accuracy, and are quite helpful for image registration, object identification, etc. Some edge-detection experiments on optical and SAR images that demonstrate the significant improvement over classical edge operators are also presented. Moreover, the template matching result based on edge information of optical reference image and SAR image also proves the validity of this method.

  15. Topological edge states of bound photon pairs

    CERN Document Server

    Gorlach, Maxim A

    2016-01-01

    We predict the existence of interaction-driven edge states of bound two-photon quasiparticles in a dimer periodic array of nonlinear optical cavities. Energy spectrum of photon pairs is dramatically richer than in the noninteracting case or in a simple lattice, featuring collapse and revival of multiple edge and bulk modes as well as edge states in continuum. Despite the unexpected breakdown of the Zak phase technique and the edge mixing of internal and center-of-mass motion we link the edge state existence to the two-photon quantum walk graph connectivity, thus uncovering the topological nature of the many-body problem in complex lattices.

  16. Edge states in Open Antiferromagnetic Heisenberg Chains

    OpenAIRE

    Qin, Shaojin; Ng, Tai-Kai; Su, Zhao-Bin

    1995-01-01

    In this letter we report our results in investigating edge effects of open antiferromagnetic Heisenberg spin chains with spin magnitudes $S=1/2, 1,3/2,2$ using the density-matrix renormalization group (DMRG) method initiated by White. For integer spin chains, we find that edge states with spin magnitude $S_{edge}=S/2$ exist, in agreement with Valence-Bond-Solid model picture. For half-integer spin chains, we find that no edge states exist for $S=1/2$ spin chain, but edge state exists in $S=3/...

  17. Hydroxyl induced edge magnetism and metallicity in armchair MoS2 nanoribbons

    Science.gov (United States)

    Cheng, Xue-Mei; Wang, Xue-Feng; Liu, Yu-Sheng; Dong, Yao-Jun; Xu, Long

    2016-03-01

    Based on ab initio density functional theory, we demonstrate systematically how nonmagnetic semiconductor armchair MoS2 nanoribbons (AMoS2NRs) become magnetic or/and metallic when being edge-passivated by OH groups. Both the Mo and S edge atoms of an AMoS2NR can adsorb OH groups but an S atom can catch one OH group only when each of its neighbor Mo atoms has already been passivated by two. The AMoS2NR becomes edge magnetic in low passivation density and edge conductive in high density. In the case of uniform edge passivation, one or both of the edges usually become metallic and nonmagnetic if the number i of OH groups per primitive cell satisfies 1≤slant inanoribbon becomes magnetic semiconductor. For i=8 the nanoribbon become nonmagnetic semiconductor again.

  18. Edge plasma in snowflake divertor

    International Nuclear Information System (INIS)

    The snowflake divertor (Ryutov 2007, Phys. Plasmas 14, 064502) uses a 2nd order null of the poloidal magnetic field instead of the 1st order null used in the standard divertor. This leads to a number of interesting geometric properties such as stronger fanning of the poloidal flux, stronger magnetic shear in the edge region, larger radiating volume, and larger connection length in the scrape-off layer. These can potentially lead to new ways for alleviating heat loads on the divertor target plates. Discussion of properties of snowflake is presented, along with results of numerical modeling. Divertor leg volume is larger in snowflake than in the standard x-point configuration, which leads to larger fraction of radiated power in the divertor. This allows the snowflake to transition to a strongly detached plasma regime more easily than for the standard x-point. Besides, stronger shearing of the magnetic field in snowflake may be beneficial for controlling magneto-hydrodynamic instabilities in the edge (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Quantum Manifestations of Graphene Edge Stress and Edge Instability: A First-Principles Study

    OpenAIRE

    Huang, Bing; Liu,Miao; Su, Ninghai; Wu, Jian; Duan, Wenhui; Gu, Bing-Lin; LIU Feng

    2010-01-01

    We have performed first-principles calculations of graphene edge stresses, which display two interesting quantum manifestations absent from the classical interpretation: the armchair edge stress oscillates with a nanoribbon width, and the zigzag edge stress is noticeably reduced by spin polarization. Such quantum stress effects in turn manifest in mechanical edge twisting and warping instability, showing features not captured by empirical potentials or continuum theory. Edge adsorption of H a...

  20. Ca L2,3-edge XANES and Sr K-edge EXAFS study of hydroxyapatite and fossil bone apatite

    Science.gov (United States)

    Zougrou, I. M.; Katsikini, M.; Brzhezinskaya, M.; Pinakidou, F.; Papadopoulou, L.; Tsoukala, E.; Paloura, E. C.

    2016-08-01

    Upon burial, the organic and inorganic components of hard tissues such as bone, teeth, and tusks are subjected to various alterations as a result of interactions with the chemical milieu of soil, groundwater, and presence of microorganisms. In this study, simulation of the Ca L 2,3-edge X-ray absorption near edge structure (XANES) spectrum of hydroxyapatite, using the CTM4XAS code, reveals that the different symmetry of the two nonequivalent Ca(1) and Ca(2) sites in the unit cell gives rise to specific spectral features. Moreover, Ca L 2,3-edge XANES spectroscopy is applied in order to assess variations in fossil bone apatite crystallinity due to heavy bacterial alteration and catastrophic mineral dissolution, compared to well-preserved fossil apatite, fresh bone, and geologic apatite reference samples. Fossilization-induced chemical alterations are investigated by means of Ca L 2,3-edge XANES and scanning electron microscopy (SEM) and are related to histological evaluation using optical microscopy images. Finally, the variations in the bonding environment of Sr and its preference for substitution in the Ca(1) or Ca(2) sites upon increasing the Sr/Ca ratio is assessed by Sr K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy.

  1. Imaging edges of nanostructured graphene

    DEFF Research Database (Denmark)

    Kling, Jens; Cagliani, Alberto; Booth, T. J.;

    Graphene, as the forefather of 2D-materials, attracts much attention due to its extraordinary properties like transparency, flexibility and outstanding high conductivity, together with a thickness of only one atom. However, graphene also possesses no band gap, which makes it unsuitable for many...... electronic applications like transistors. It has been shown theoretically that by nanostructuring pristine graphene, e.g. with regular holes, the electronic properties can be tuned and a band gap introduced. The size, distance and edge termination of these “defects” influence the adaptability....... Such nanostructuring can be done experimentally, but especially characterization at atomic level is a huge challenge. High-resolution TEM (HRTEM) is used to characterize the atomic structure of graphene. We optimized the imaging conditions used for the FEI Titan ETEM. To reduce the knock-on damage of the carbon atoms...

  2. Compact K-edge densitometer

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory has designed, built, and is currently testing a compact K-edge densitometer for use by International Atomic Energy Agency (IAEA) inspectors. The unit, which can easily be moved from one location to another within a facility, is positioned outside a glovebox with the body of the instrument inserted into the glove. A fixture inside the glovebox fits around the body and positions a sample holder. A hand-held high-purity germanium detector powered by a battery pack and a Davidson portable multichannel analyzer (MCA) is used to measure the transmission through plutonium nitrate solutions at E/sub Y/ = 121.1 and 122.2 keV. The Davidson MCA is programmed to lead the user through the measurement procedure and perform all the data analyses. The instrument is currently installed at the Safeguards Analytical Laboratory, where IAEA personnel are evaluating its accuracy, ease of operation, and safety. 5 references, 5 figures, 5 tables

  3. Composite superconducting transition edge bolometer

    International Nuclear Information System (INIS)

    A composite far-infrared bolometer has been constructed that uses an aluminum film at the superconducting transition temperature of 1.3 K as the temperature-sensitive element. The film is evaporated on one edge of a 4 x 4-mm sapphire substrate, which is coated on the reverse side with an absorbing film of bismuth. The best bolometer has an electrical NEP of (1.7 +- 0.1) x 10-15 W Hz-1/2 at 2 Hz, and a specific detectivity D* of (1.1 +- 0.1) x 1014 cm W-1 Hz1/2. This measured electrical NEP is within a factor 2 of the fundamental thermal noise limit

  4. Bound on m-restricted Edge Connectivity

    Institute of Scientific and Technical Information of China (English)

    Jian-ping Ou; Fu-ji Zhang

    2003-01-01

    An m-restricted edge cut is an edge cut that separates a connected graph into a disconnected one with no components having order less than m. m-restricted edge connectivity λm is the cardinality of a minimum m-restricted edge cut. Let G be a connected k-regular graph of order at least 2m that contains m-restricted edge cuts and X be a subgraph of G. Let( )(X) denote the number of edges with one end in X and the other not in X and ξm = min{( )(X): X is a connected vertex-induced subgraph of order m}. It is proved in this paper that if G has girth at least m/2 + 2, then λm ≤ξm. The upper bound of λm is sharp.

  5. Novel wavelet synthesis for edge detection

    International Nuclear Information System (INIS)

    This paper presents a novel wavelet synthesis approach based on scale multiplication of concordant detail bands coefficients of dyadic wavelet transform that highlights edge structure and suppresses noise in an image. The algorithm works on default threshold values for image denoising. However, to achieve optimality of edge detection, image decomposition level through wavelet transform is not unique and depends upon image resolution along with its structural parameters. Scale controls the significance of edges to be shown. High resolution images with thick edges support high level decomposition and vice versa. The paper presents a novel edge detection paradigm in which innovative wavelet synthesis of detail bands based on nearest neighborhood interpolation and wavelet scale correlation is conceived such that the reconstructed image fabricates its edge map. (author)

  6. Object detection using categorised 3D edges

    DEFF Research Database (Denmark)

    Kiforenko, Lilita; Buch, Anders Glent; Bodenhagen, Leon; Krüger, Norbert

    2015-01-01

    is made possible by the explicit use of edge categories in the feature descriptor. We quantitatively compare our approach with the state-of-the-art template based Linemod method, which also provides an effective way of dealing with texture-less objects, tests were performed on our own object dataset......In this paper we present an object detection method that uses edge categorisation in combination with a local multi-modal histogram descriptor, all based on RGB-D data. Our target application is robust detection and pose estimation of known objects. We propose to apply a recently introduced edge...... categorisation algorithm for describing objects in terms of its different edge types. Relying on edge information allow our system to deal with objects with little or no texture or surface variation. We show that edge categorisation improves matching performance due to the higher level of discrimination, which...

  7. Mechanical tension drives cell membrane fusion

    OpenAIRE

    Kim, Ji Hoon; Ren, Yixin; Ng, Win Pin; Li, Shuo; Son, Sungmin; Kee, Yee-Seir; Zhang, Shiliang; Zhang, Guofeng; Fletcher, Daniel A.; Robinson, Douglas N.; Chen, Elizabeth H.

    2015-01-01

    Membrane fusion is an energy-consuming process that requires tight juxtaposition of two lipid bilayers. Little is known about how cells overcome energy barriers to bring their membranes together for fusion. Previously, we have shown that cell-cell fusion is an asymmetric process in which an “attacking” cell drills finger-like protrusions into the “receiving” cell to promote cell fusion. Here we show that the receiving cell mounts a Myosin II (MyoII)-mediated mechanosensory response to its inv...

  8. Edge Detection for Pattern Recognition: A Survey

    OpenAIRE

    James, Alex Pappachen

    2016-01-01

    This review provides an overview of the literature on the edge detection methods for pattern recognition that inspire from the understanding of human vision. We note that edge detection is one of the most fundamental process within the low level vision and provides the basis for the higher level visual intelligence in primates. The recognition of the patterns within the images relate closely to the spatiotemporal processes of edge formations, and its implementation needs a crossdisciplanry ap...

  9. Selective Electroless Silver Deposition on Graphene Edges

    DEFF Research Database (Denmark)

    Durhuus, D.; Larsen, M. V.; Andryieuski, Andrei;

    2015-01-01

    We demonstrate a method of electroless selective silver deposition on graphene edges or between graphene islands without covering the surface of graphene. Modifications of the deposition recipe allow for decoration of graphene edges with silver nanoparticles or filling holes in damaged graphene...... on silica substrate and thus potentially restoring electric connectivity with minimal influence on the overall graphene electrical and optical properties. The presented technique could find applications in graphene based transparent conductors as well as selective edge functionalization and can be extended...

  10. Edge and line detection of complicated and blurred objects

    OpenAIRE

    Haugsdal, Kari

    2010-01-01

    This report deals with edge and line detection in pictures with complicated and/or blurred objects. It explores the alternatives available, in edge detection, edge linking and object recognition. Choice of methods are the Canny edge detection and Local edge search processing combined with regional edge search processing in the form of polygon approximation.

  11. Fuel cell electrode interconnect contact material encapsulation and method

    Energy Technology Data Exchange (ETDEWEB)

    Derose, Anthony J.; Haltiner, Jr., Karl J.; Gudyka, Russell A.; Bonadies, Joseph V.; Silvis, Thomas W.

    2016-05-31

    A fuel cell stack includes a plurality of fuel cell cassettes each including a fuel cell with an anode and a cathode. Each fuel cell cassette also includes an electrode interconnect adjacent to the anode or the cathode for providing electrical communication between an adjacent fuel cell cassette and the anode or the cathode. The interconnect includes a plurality of electrode interconnect protrusions defining a flow passage along the anode or the cathode for communicating oxidant or fuel to the anode or the cathode. An electrically conductive material is disposed between at least one of the electrode interconnect protrusions and the anode or the cathode in order to provide a stable electrical contact between the electrode interconnect and the anode or cathode. An encapsulating arrangement segregates the electrically conductive material from the flow passage thereby, preventing volatilization of the electrically conductive material in use of the fuel cell stack.

  12. A new fuzzy edge detection algorithm

    Institute of Scientific and Technical Information of China (English)

    SunWei; XiaLiangzheng

    2003-01-01

    Based upon the maximum entropy theorem of information theory, a novel fuzzy approach for edge detection is presented. Firsdy, a definition of fuzzy partition entropy is proposed after introducing the concepts of fuzzy probability and fuzzy partition. The relation of the probability partition and the fuzzy c-partition of the image gradient are used in the algorithm. Secondly, based on the conditional probabilities and the fuzzy partition, the optimal thresholding is searched adaptively through the maximum fuzzy entropy principle, and then the edge image is obtained. Lastly, an edge-enhancing procedure is executed on the edge image. The experimental results show that the proposed approach performs well.

  13. An edge index for topological insulators

    Science.gov (United States)

    Prodan, Emil

    2009-03-01

    Topological insulators display dissipationless currents flowing at the edges of the samples. These currents are associated to chiral edge modes, whose existence is intrinsically linked to the topology of the electronic states of the bulk. The edge modes can be easily investigated when the edges are smooth and have a periodicity, but as soon as the periodicity is absent, the problem becomes un-traceable by purely theoretical means. In my talk I will exemplify the use of non-commutative calculus to explore the properties, especially the stability of the edge modes. For example, using such techniques one can give a fairly elementary proof that the edge modes in Chern insulators survive even for a rough (random) edge. Similarly, for the Spin-Hall effect, one can define an observable and its associated current whose conductance remains quantized during various deformations of the Hamiltonian system. It turns out that in all cases, the edge conductance is given by the index of a Fredholm operator, which provides a new topological invariant linked directly to the edge rather than the bulk.

  14. IMAGE ANALYSIS BASED ON EDGE DETECTION TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    纳瑟; 刘重庆

    2002-01-01

    A method that incorporates edge detection technique, Markov Random field (MRF), watershed segmentation and merging techniques was presented for performing image segmentation and edge detection tasks. It first applies edge detection technique to obtain a Difference In Strength (DIS) map. An initial segmented result is obtained based on K-means clustering technique and the minimum distance. Then the region process is modeled by MRF to obtain an image that contains different intensity regions. The gradient values are calculated and then the watershed technique is used. DIS calculation is used for each pixel to define all the edges (weak or strong) in the image. The DIS map is obtained. This help as priority knowledge to know the possibility of the region segmentation by the next step (MRF), which gives an image that has all the edges and regions information. In MRF model,gray level l, at pixel location i, in an image X, depends on the gray levels of neighboring pixels. The segmentation results are improved by using watershed algorithm. After all pixels of the segmented regions are processed, a map of primitive region with edges is generated. The edge map is obtained using a merge process based on averaged intensity mean values. A common edge detectors that work on (MRF) segmented image are used and the results are compared. The segmentation and edge detection result is one closed boundary per actual region in the image.

  15. Visible imaging of edge turbulence in NSTX

    International Nuclear Information System (INIS)

    Edge plasma turbulence in tokamaks and stellarators is believed to cause the radical heat and particle flux across the separatrix and into the scrape-off-layers of these devices. This paper describes initial measurements of 2-D space-time structure of the edge density turbulence made using a visible imaging diagnostic in the National Spherical Torus Experiment (NSTX). The structure of the edge turbulence is most clearly visible using a method of gas puff imaging to locally illuminate the edge density turbulence

  16. Edges and Switches, Tunnels and Bridges

    CERN Document Server

    Eppstein, David; Mumford, Elena; Speckmann, Bettina

    2007-01-01

    Edge casing is a well-known method to improve the readability of drawings of non-planar graphs. A cased drawing orders the edges of each edge crossing and interrupts the lower edge in an appropriate neighborhood of the crossing. Certain orders will lead to a more readable drawing than others. We formulate several optimization criteria that try to capture the concept of a "good" cased drawing. Further, we address the algorithmic question of how to turn a given drawing into an optimal cased drawing. For many of the resulting optimization problems, we either find polynomial time algorithms or NP-hardness results.

  17. Edges and Switches, Tunnels and Bridges

    OpenAIRE

    Eppstein, D; Kreveld, van, MJ Marc; Mumford, E Elena; Speckmann, B Bettina

    2007-01-01

    Edge casing is a well-known method to improve the readability of drawings of non-planar graphs. A cased drawing orders the edges of each edge crossing and interrupts the lower edge in an appropriate neighborhood of the crossing. Certain orders will lead to a more readable drawing than others. We formulate several optimization criteria that try to capture the concept of a "good" cased drawing. Further, we address the algorithmic question of how to turn a given drawing into an optimal cased dra...

  18. A Gravitational Edge Detection for Multispectral Images

    Directory of Open Access Journals (Sweden)

    Genyun Sun

    2013-07-01

    Full Text Available Gravitational edge detection is one of the new edge detection algorithms that is based on the law of gravity. This algorithm assumes that each image pixel is a celestial body with a mass represented by its grayscale intensity and their interactions are based on the Newtonian laws of gravity. In this article, a multispectral version of the algorithm is introduced. The method uses gravitational techniques in combination with metric tensor to detect edges of multispectral images including color images. To evaluate the performances of the proposed algorithm, several experiments are performed. The experimental results confirm the efficiency of the multispectral gravitational edge detection.  

  19. KIF20A-Mediated RNA Granule Transport System Promotes the Invasiveness of Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Keisuke Taniuchi

    2014-12-01

    Full Text Available Pancreatic cancers are aggressive because they are highly invasive and highly metastatic; moreover, effective treatments for aggressive pancreatic cancers are lacking. Here, we report that the motor kinesin protein KIF20A promoted the motility and invasiveness of pancreatic cancer cells through transporting the RNA-binding protein IGF2BP3 and IGF2BP3-bound transcripts toward cell protrusions along microtubules. We previously reported that IGF2BP3 and its target transcripts are assembled into cytoplasmic stress granules of pancreatic cancer cells, and that IGF2BP3 promotes the motility and invasiveness of pancreatic cancer cells through regulation of localized translation of IGF2BP3-bound transcripts in cell protrusions. We show that knockdown of KIF20A inhibited accumulation of IGF2BP3-containing stress granules in cell protrusions and suppressed local protein expression from specific IGF2BP3-bound transcripts, ARF6 and ARHGEF4, in the protrusions. Our results provide insight into the link between regulation of KIF20A-mediated trafficking of IGF2BP3-containing stress granules and modulation of the motility and invasiveness in pancreatic cancers.

  20. A numerical investigation into the effects of Reynolds number on the flow mechanism induced by a tubercled leading edge

    Science.gov (United States)

    Rostamzadeh, Nikan; Kelso, Richard M.; Dally, Bassam

    2016-05-01

    Leading-edge modifications based on designs inspired by the protrusions on the pectoral flippers of the humpback whale (tubercles) have been the subject of research for the past decade primarily due to their flow control potential in ameliorating stall characteristics. Previous studies have demonstrated that, in the transitional flow regime, full-span wings with tubercled leading edges outperform unmodified wings at high attack angles. The flow mechanism associated with such enhanced loading traits is, however, still being investigated. Also, the performance of full-span tubercled wings in the turbulent regime is largely unexplored. The present study aims to investigate Reynolds number effects on the flow mechanism induced by a full-span tubercled wing with the NACA-0021 cross-sectional profile in the transitional and near-turbulent regimes using computational fluid dynamics. The analysis of the flow field suggests that, with the exception of a few different flow features, the same underlying flow mechanism, involving the presence of transverse and streamwise vorticity, is at play in both cases. With regard to lift-generation characteristics, the numerical simulation results indicate that in contrast to the transitional flow regime, where the unmodified NACA-0021 undergoes a sudden loss of lift, in the turbulent regime, the baseline foil experiences gradual stall and produces more lift than the tubercled foil. This observation highlights the importance of considerations regarding the Reynolds number effects and the stall characteristics of the baseline foil, in the industrial applications of tubercled lifting bodies.

  1. Edge mode spectroscopy and imaging for film edge properties in magnetic nanostructures

    Science.gov (United States)

    McMichael, Robert

    2014-03-01

    Lithography is an act of violence. Often, films are almost entirely obliterated by patterning, leaving only nanostructures behind with film edges that have borne the brunt of the damage, edges that carry with them the scars of energetic ion bombardment, reactive ions, liftoff and exposure to ambient conditions. In this talk, I will present a variation on ferromagnetic resonance force microscopy that can provide insight into the magnetic properties of film edges in magnetic nanostructures. The method relies on the non-uniformity of the magnetic field in patterned-film nanostructures that are magnetized in-plane, specifically, the low-field regions that form near where the magnetization is directed normal to the edge. In these regions, localized precession forms as trapped spin wave modes, and the resonance condition of these modes serves as an indicator of the edge properties. I will present modeling and measurements on a 500 nm diameter, 25 nm thick Permalloy disk to illustrate the method. Micromagnetic modeling of this disk predicts a main mode that is nearly uniform across the sample and three localized edge modes with higher resonance fields. The spectra measured with various tip positions and mode imaging are consistent with the modeling results. In addition to a strong center mode, three distinct edge modes are observed when the tip is near the disk edge. For a symmetric disk, the modeling predicts that the edge mode resonances are identical on the two opposite edges. However, the measured edge mode resonances on opposite edges of the disk are detected at different resonance fields, suggesting inhomogeneity of the edge properties. By rotating the applied field, we control the position of the localized edge mode along the edge of the disk and confirm that the edge mode resonance field has a strong angular dependence, showing that edge mode properties can vary significantly in a nominally circular disk.

  2. On the theory of cell migration: durotaxis and chemotaxis

    OpenAIRE

    Diego Íñiguez, Javier

    2013-01-01

    Cell migration is a fundamental element in a variety of physiological and pathological processes. Alteration of its regulatory mechanisms leads to loss of adhesion and increased motility, critical steps in the initial stages of metastasis. Consequently, cell migration has become the focus of intensive experimental and theoretical studies; however the understanding many of its mechanisms remains elusive. Cell migration is the result of a periodic sequence of protrusion, adhesion remodeling and...

  3. Introduction: Centering on the Edge

    Directory of Open Access Journals (Sweden)

    Anne Dalke

    2007-01-01

    Full Text Available [First two paragraphs][T]here is growing resistance to embracing interdisciplinarity, in part because we are simply tired of hearing about it and in part because, in practice, it often requires attending the meetings of more than one department. Few are willing to concede that the reason we now need it so desperately stems from the mismatch between how we structured knowledge decades ago to create departments and how we organize it today. (Tartar, 2005, p. B2 As the international academic enterprise settles into the first decade of the twenty-first century, the future of our work is in flux. Academic specializations established a century ago no longer adequately reflect the growing points of human thought, and the opening of higher education to wider populations of students has challenged the relevance of traditional disciplines for future lives and careers. In this context, teachers and scholars have been rethinking the academic enterprise and the functions it serves for their students; new centers are being organized around what was once thought to mark the edge of knowledge-making. At Bryn Mawr College in the USA, where many of the contributors of this special issue teach, the Center for Science in Society has been an important locus for such restructuring.

  4. Yukawa Unification on the Edge

    CERN Document Server

    Poh, Zijie

    2015-01-01

    In this paper we analyze Yukawa unification in a three family SO(10) SUSY GUT. We perform a global $\\chi^2$ analysis and show that SUSY effects do not decouple even though the universal scalar mass parameter at the GUT scale, $m_{16}$, is found to lie between 15 and 30 TeV with the best fit given for $m_{16} \\approx 25$ TeV. Note, SUSY effects don't decouple since stops and bottoms have mass of order 5 TeV, due to RG running from $M_{GUT}$. The model has many testable predictions. Gauginos are the lightest sparticles and the light Higgs boson is very much Standard Model-like. The model is consistent with flavor and CP observables with the $BR(\\mu \\to e\\gamma)$ close to the experimental upper bound. With such a large value of $m_{16}$ we clearly cannot be considered "natural" SUSY nor are we "Split" SUSY. We are thus in the region in between or "SUSY on the Edge."

  5. Reduction in Edge-Ringing in Aberrated Images of Coherent Edge Objects by Multishaded Aperture

    OpenAIRE

    Venkanna Mekala; Karuna Sagar Dasari

    2014-01-01

    The images of a straight edge in coherent illumination produced by an optical system with circular aperture and apodized with multiple filters have been studied. The most common problem encountered in the coherent-imaging techniques is the edge-ringing. To minimize the edge-ringing, multishaded aperture method has been proposed. Image intensity distribution curves are drawn and edge-ringing values are evaluated. The results are compared to that of the airy case with the use of single, double ...

  6. Edge Detection with Sub-pixel Accuracy Based on Approximation of Edge with Erf Function

    OpenAIRE

    M. Hagara; P. Kulla

    2011-01-01

    Edge detection is an often used procedure in digital image processing. For some practical applications is desirable to detect edges with sub-pixel accuracy. In this paper we present edge detection method for 1-D images based on approximation of real image function with Erf function. This method is verified by simulations and experiments for various numbers of samples of simulated and real images. Results of simulations and experiments are also used to compare proposed edge detection scheme wi...

  7. Manoeuvring along the edge of breathlessness

    DEFF Research Database (Denmark)

    Jellington, Maria Omel; Overgaard, Dorthe; Sørensen, Erik Elgaard

    2016-01-01

    . Third, hermeneutical principles were used as all data were interpreted from the viewpoint of each theme. Results Three themes were identified: Manoeuvring along the edge; Dyspnoea within the pattern; and Dyspnoea outside the pattern. They were encompassed by the main finding: Manoeuvring along the edge...

  8. Annotated Bibliography of EDGE2D Use

    International Nuclear Information System (INIS)

    This annotated bibliography is intended to help EDGE2D users, and particularly new users, find existing published literature that has used EDGE2D. Our idea is that a person can find existing studies which may relate to his intended use, as well as gain ideas about other possible applications by scanning the attached tables

  9. Comprehensive Infrared Image Edge detection Algorithm

    Directory of Open Access Journals (Sweden)

    Abhishek Gudipalli

    2012-10-01

    Full Text Available Edge detection is one of the most powerful image analysis tools for enhancing and detecting edges. Indeed, identifying and localizing edges are a low level task in a variety of applications such as 3-D reconstruction, shape recognition, image compression, enhancement, and restoration. This paper introduces a new algorithm for detecting edges based on color space models. In this RGB image is taken as an input image and transforming the RGB image to color models such as YUV, YCbCr and XYZ. The edges have been detected for each component in color models separately and compared with the original image of that particular model. In order to measure the quality assessment between images, SSIM (Structural Similarity Index Method and VIF (Visual Information Fidelity has been calculated. The results have shown that XYZ color model is having high SSIM value and VIF value. In the previous papers, edge detection based on RGB color model has low SSIM and VIF values. So by converting the images into different color models shows a significant improvement in detection of edges. Keywords: Edge detection, Color models, SSIM, VIF.

  10. Breaking graph symmetries by edge colourings

    OpenAIRE

    Lehner, Florian

    2016-01-01

    The distinguishing index $D'(G)$ of a graph $G$ is the least number of colours needed in an edge colouring which is not preserved by any non-trivial automorphism. Broere and Pil\\'sniak conjectured that if every non-trivial automorphism of a countable graph $G$ moves infinitely many edges, then $D'(G) \\leq 2$. We prove this conjecture.

  11. Annotated Bibliography of EDGE2D Use

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Strachan and G. Corrigan

    2005-06-24

    This annotated bibliography is intended to help EDGE2D users, and particularly new users, find existing published literature that has used EDGE2D. Our idea is that a person can find existing studies which may relate to his intended use, as well as gain ideas about other possible applications by scanning the attached tables.

  12. On edge graceful labelings of disjoint unions of $2r$-regular edge graceful graphs

    OpenAIRE

    Riskin, Adrian; Weidman, Georgia

    2006-01-01

    We prove that if $G$ is a $2r$-regular edge graceful $(p,q)$ graph with $(r,kp)=1$ then $kG$ is edge graceful for odd $k$. We also prove that for certain specific classes of $2r$-regular edge graceful graphs it is possible to drop the requirement that $(r,kp)=1$

  13. More results on oscillating edge-flames

    International Nuclear Information System (INIS)

    We examine a simple model of a side-anchored non-premixed edge-flame in order to gain insights into the oscillations that are sometimes observed in microgravity candle burning, flame-spread over liquids, etc. Previous results describe the role played by the Lewis number of the fuel, and the Damkoehler number, and here we examine both the effects of an on-edge and off-edge convective flow, and the effects of a heat sink. The on-edge flow and the heat sink tend to destabilize and the off-edge flow tends to stabilize, results consistent with our hypothesis regarding the genesis of the oscillations. (c) 2000 American Institute of Physics

  14. Magnetism of zigzag edge phosphorene nanoribbons

    International Nuclear Information System (INIS)

    We have investigated, by means of ab initio calculations, the electronic and magnetic structures of zigzag edge phosphorene nanoribbons (ZPNRs) with various widths. The stable magnetic state was found in pristine ZPNRs by allowing the systems to be spin-polarized. The ground state of pristine ZPNRs prefers ferromagnetic order in the same edge but antiferromagnetic order between two opposite edges. The magnetism arises from the dangling bond states as well as edge localized π-orbital states. The presence of a dangling bond is crucial to the formation of the magnetism of ZPNRs. The hydrogenated ZPNRs get nonmagnetic semiconductors with a direct band gap. While, the O-saturated ZPNRs show magnetic ground states due to the weak P-O bond in the ribbon plane between the pz-orbitals of the edge O and P atoms.

  15. Cascading Edge Failures: A Dynamic Network Process

    CERN Document Server

    Zhang, June

    2016-01-01

    This paper considers the dynamics of edges in a network. The Dynamic Bond Percolation (DBP) process models, through stochastic local rules, the dependence of an edge $(a,b)$ in a network on the states of its neighboring edges. Unlike previous models, DBP does not assume statistical independence between different edges. In applications, this means for example that failures of transmission lines in a power grid are not statistically independent, or alternatively, relationships between individuals (dyads) can lead to changes in other dyads in a social network. We consider the time evolution of the probability distribution of the network state, the collective states of all the edges (bonds), and show that it converges to a stationary distribution. We use this distribution to study the emergence of global behaviors like consensus (i.e., catastrophic failure or full recovery of the entire grid) or coexistence (i.e., some failed and some operating substructures in the grid). In particular, we show that, depending on...

  16. Edge exchangeable models for network data

    CERN Document Server

    Crane, Harry

    2016-01-01

    Exchangeable models for vertex labeled graphs cannot replicate the large sample behaviors of sparsity and power law degree distributions observed in many network datasets. Out of this mathematical impossibility emerges the question of how network data can be modeled in a way that reflects known empirical behaviors and respects basic statistical principles. We address this question by observing that edges, not vertices, act as the statistical units in most network datasets, making a theory of edge labeled networks more natural for most applications. Within this context we introduce the new invariance principle of {\\em edge exchangeability}, which unlike its vertex exchangeable counterpart can produce networks with sparse and/or power law structure. We characterize the class of all edge exchangeable network models and identify a particular two parameter family of models with suitable theoretical properties for statistical inference. We discuss issues of estimation from edge exchangeable models and compare our a...

  17. A synthesis for exactly 3-edge-connected graphs

    OpenAIRE

    Kingsford, Carl; Marçais, Guillaume

    2009-01-01

    A multigraph is exactly k-edge-connected if there are exactly k edge-disjoint paths between any pair of vertices. We characterize the class of exactly 3-edge-connected graphs, giving a synthesis involving two operations by which every exactly 3-edge-connected multigraph can be generated. Slightly modified syntheses give the planar exactly 3-edge-connected graphs and the exactly 3-edge-connected graphs with the fewest possible edges.

  18. Edge Detection with Sub-pixel Accuracy Based on Approximation of Edge with Erf Function

    Directory of Open Access Journals (Sweden)

    M. Hagara

    2011-06-01

    Full Text Available Edge detection is an often used procedure in digital image processing. For some practical applications is desirable to detect edges with sub-pixel accuracy. In this paper we present edge detection method for 1-D images based on approximation of real image function with Erf function. This method is verified by simulations and experiments for various numbers of samples of simulated and real images. Results of simulations and experiments are also used to compare proposed edge detection scheme with two often used moment-based edge detectors with sub-pixel precision.

  19. Elastically Deformable Side-Edge Link for Trailing-Edge Flap Aeroacoustic Noise Reduction

    Science.gov (United States)

    Khorrami, Mehdi R. (Inventor); Lockard, David P. (Inventor); Moore, James B. (Inventor); Su, Ji (Inventor); Turner, Travis L. (Inventor); Lin, John C. (Inventor); Taminger, Karen M. (Inventor); Kahng, Seun K. (Inventor); Verden, Scott A. (Inventor)

    2014-01-01

    A system is provided for reducing aeroacoustic noise generated by an aircraft having wings equipped with trailing-edge flaps. The system includes a plurality of elastically deformable structures. Each structure is coupled to and along one of the side edges of one of the trailing-edge flaps, and is coupled to a portion of one of the wings that is adjacent to the one of the side edges. The structures elastically deform when the trailing-edge flaps are deployed away from the wings.

  20. Edge states in a honeycomb lattice: effects of anisotropic hopping and mixed edges

    OpenAIRE

    Dahal, Hari P.; Hu, Zi-Xiang; Sinitsyn, N. A.; YANG Kun; Balatsky, A. V.

    2009-01-01

    We study the edge states in graphene in the presence of a magnetic field perpendicular to the plane of the lattice. Most of the works done so far discuss the edge states in either zigzag or armchair edge graphene considering an isotropic electron hopping. In practice, graphene can have mixture of armchair and zigzag edges and the electron hopping can be anisotropic, which is the subject of this article. We predict that the mixed edges smear the enhanced local density of states (LDOS) at E=0 o...

  1. Modeling the ICRF-edge interaction in H-modes

    International Nuclear Information System (INIS)

    The understanding of the ICRF-edge plasma interaction has increased greatly in recent years. One important result has been the virtual elimination of ICRF-specific impurities during ICRF heating on JET. It has been shown that impurity release from ICRF antennas is an effect of rf sheaths. An rf-sheath model gives good agreement with JET impurity influx data and suggests a practical prescription for reducing impurities to negligible levels. Another important development, made possible by the reduction in impurities, was the achievement of H-modes induced by ICRF heating alone under conditions in which rf sheaths were expected to be robust (monopole phasing) and to be negligible (dipole phasing). It was found that the quality, duration and termination mechanism of the H-mode was different in the two cases. In this paper, the authors describe simulation results and experimental data which provide a possible explanation for the unique properties of the monopole ICRF H-mode. The simulation shows that the rf sheaths near the antenna drive large convective cells, which penetrate the SOL and cause enhanced edge transport. The edge convection is a good candidate to explain the reduction in quality of the highly-sheared, poloidally uniform H-mode transport barrier, and the resulting flattening of the SOL density and temperature profiles may explain the longer duration and the absence of a radiative collapse for the monopole H-mode. An analysis of JET data shows the existence of phasing-dependent ICRF-enhanced edge transport in agreement with the theoretical model. The 2D simulation results are discussed and compared with the available experimental data. This work suggest that ICRF antennas in monopole or FWCD phasing provide another practical means of biasing the edge plasma to control the global confinement, central density and impurity accumulation in H-mode operation

  2. The Hidden K-edge Signal in K-edge Imaging

    CERN Document Server

    Bateman, Christopher J; de Ruiter, Niels J A; Butler, Anthony P; Butler, Philip H; Renaud, Peter F

    2015-01-01

    K-edge imaging is commonly used for viewing contrast pharmaceuticals in a variety of multi-energy x-ray imaging techniques, ranging from dual-energy and spectral computed tomography to fluoroscopy. When looking for the K-edge signal of a specific contrast, by taking measurements either side of the K-edge, it is found that the K-edge is not always observable for low concentrations. We have also observed that the ability to see the K-edge is unit dependent - a K-edge that is not observable in computed tomography (CT) reconstructed linear attenuation units can often be made visible by converting to Hounsfield units. This paper presents an investigation of this K-edge hiding phenomenon. We conclude that if a multi-energy x-ray measurement of any K-edge material contains a signal of any other material, then there will be a positive concentration of that K-edge material below which its K-edge cannot be observed without extracting the K-edge signal through means of basis decomposition. Mathematical descriptions of t...

  3. One isoform of Arg/Abl2 tyrosine kinase is nuclear and the other seven cytosolic isoforms differently modulate cell morphology, motility and the cytoskeleton

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, Cristina; Torsello, Barbara; Di Stefano, Vitalba; Zipeto, Maria A.; Facchetti, Rita; Bombelli, Silvia; Perego, Roberto A., E-mail: roberto.perego@unimib.it

    2013-08-01

    The non-receptor tyrosine kinase Abelson related gene (Arg/Abl2) regulates cell migration and morphogenesis by modulating the cytoskeleton. Arg promotes actin-based cell protrusions and spreading, and inhibits cell migration by attenuating stress fiber formation and contractility via activation of the RhoA inhibitor, p190RhoGAP, and by regulating focal adhesion dynamics also via CrkII phosphorylation. Eight full-length Arg isoforms with different N- and C-termini are endogenously expressed in human cells. In this paper, the eight Arg isoforms, subcloned in the pFLAG-CMV2 vector, were transfected in COS-7 cells in order to study their subcellular distribution and role in cell morphology, migration and cytoskeletal modulation. The transfected 1BSCTS Arg isoform has a nuclear distribution and phosphorylates CrkII in the nucleus, whilst the other isoforms are detected in the cytoplasm. The 1BLCTL, 1BSCTL, 1ASCTS isoforms were able to significantly decrease stress fibers, induce cell shrinkage and filopodia-like protrusions with a significant increase in p190RhoGAP phosphorylation. In contrast, 1ALCTL, 1ALCTS, 1ASCTL and 1BLCTS isoforms do not significantly decrease stress fibers and induce the formation of retraction tail-like protrusions. The 1BLCTL and 1ALCTL isoforms have different effects on cell migration and focal adhesions. All these data may open new perspectives to study the mechanisms of cell invasiveness. -Highlights: • Each of the eight Arg isoforms was transfected in COS-7 cells. • Only the 1BSCTS Arg isoform has a nuclear distribution in transfected cells. • The cytoplasmic isoforms and F-actin colocalize cortically and in cell protrusions. • Arg isoforms differently phosphorylate p190RhoGAP and CrkII. • Arg isoforms differently modulate stress fibers, cell protrusions and motility.

  4. Background Modelling Using Edge-Segment Distributions

    Directory of Open Access Journals (Sweden)

    Jaemyun Kim

    2013-02-01

    Full Text Available We propose an edge‐segment‐based statistical background modelling algorithm to detect the moving edges for the detection of moving objects using a static camera. Traditional pixel intensity‐based background modelling algorithms face difficulties in dynamic environments since they cannot handle sudden changes in illumination. They also bring out ghosts when a sudden change occurs in the scene. To cope with this issue, intensity and noise robust edge‐based features have emerged. However, existing edge‐pixel‐based methods suffer from scattered moving edge pixels since they cannot utilize the shape. Moreover, traditional segment‐ based methods cannot handle edge shape variations and miss moving edges when they come close to the background edges. Unlike traditional approaches, our proposed method builds the background model from ordinary training frames that may contain moving objects. Furthermore, it does not leave any ghosts behind. Moreover, our method uses an automatic threshold for every background edge distribution for matching. This makes our approach robust to illumination change, camera movement and background motion. Experiments show that our method outperforms others and can detect moving edges efficiently despite the above mentioned difficulties.

  5. Auditing to the cutting edge

    Energy Technology Data Exchange (ETDEWEB)

    Good, L.; Wirdzek, P.

    1999-07-01

    Equipment? System? Building? Campus? Neighborhood? Community? Region? What is to be audited and what needs to be corrected? Can the energy management professional decide, or should the customer? Over the last few decades, energy professionals have been evaluating energy use in order to balance clients' expenditures with acceptable levels of service. Traditionally, professional expertise and creativity have been limited more by budget than any other single element. Today, energy and the environment are tightly intertwined. In the future, effective energy management may not be possible without considering the relationships between them. Conversely, environmental protection cannot be achieved without considering energy production, distribution, and use. To this end, two powerful federal organizations, the US Environmental Protection Agency (EPA) and the US Department of Energy (DOE), have been engaged in defining the interrelationships of these areas and fashioning national energy policies aimed at awakening Americans to these facts. Environmental demands are becoming a factor in efficiency equations. Energy management professionals should prepare a response. They will face demands for cutting-edge audits that reach further than giving utility power just a trim in the energy barber shop. Survival in the business of energy management will require a broader perspective. One need only look to current advertisements by national and international corporations which praise the environmental benefits of their products and even their places of business as cleaner than their competitors'. For the energy management professional then, energy diversity and source versus site considerations are opportunities to be identified in the audit process, in addition to replacement of inefficient equipment. The country is rich with technology choices, with documented experience, and with the knowledge to create systems that can mine deep savings. True, some have niche

  6. Edge- and Node-Disjoint Paths in P Systems

    Directory of Open Access Journals (Sweden)

    Michael J. Dinneen

    2010-10-01

    Full Text Available In this paper, we continue our development of algorithms used for topological network discovery. We present native P system versions of two fundamental problems in graph theory: finding the maximum number of edge- and node-disjoint paths between a source node and target node. We start from the standard depth-first-search maximum flow algorithms, but our approach is totally distributed, when initially no structural information is available and each P system cell has to even learn its immediate neighbors. For the node-disjoint version, our P system rules are designed to enforce node weight capacities (of one, in addition to edge capacities (of one, which are not readily available in the standard network flow algorithms.

  7. Incoherent synchrotron emission of laser-driven plasma edge

    Energy Technology Data Exchange (ETDEWEB)

    Serebryakov, D. A., E-mail: dmserebr@gmail.com; Nerush, E. N.; Kostyukov, I. Yu. [Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod 603950 (Russian Federation); Nizhny Novgorod State University, 23 Gagarin Avenue, Nizhny Novgorod 603950 (Russian Federation)

    2015-12-15

    When a relativistically intense linearly polarized laser pulse is incident on an overdense plasma, a dense electron layer is formed on the plasma edge which relativistic motion results in high harmonic generation, ion acceleration, and incoherent synchrotron emission of gamma-photons. Here we present a self-consistent analytical model that describes the edge motion and apply it to the problem of incoherent synchrotron emission by ultrarelativistic plasma electrons. The model takes into account both coherent radiation reaction from high harmonics and incoherent radiation reaction in the Landau–Lifshitz form. The analytical results are in agreement with 3D particle-in-cell simulations in a certain parameter region that corresponds to the relativistic electronic spring interaction regime.

  8. Differential Search Algorithm Based Edge Detection

    Science.gov (United States)

    Gunen, M. A.; Civicioglu, P.; Beşdok, E.

    2016-06-01

    In this paper, a new method has been presented for the extraction of edge information by using Differential Search Optimization Algorithm. The proposed method is based on using a new heuristic image thresholding method for edge detection. The success of the proposed method has been examined on fusion of two remote sensed images. The applicability of the proposed method on edge detection and image fusion problems have been analysed in detail and the empirical results exposed that the proposed method is useful for solving the mentioned problems.

  9. Edge of Chaos and Genesis of Turbulence

    CERN Document Server

    Chian, Abraham C -L; Rempel, Erico

    2013-01-01

    The edge of chaos is analyzed in a spatially extended system, modeled by the regularized long-wave equation, prior to the transition to permanent spatiotemporal chaos. In the presence of coexisting attractors, a chaotic saddle is born at the basin boundary due to a smooth-fractal metamorphosis. As a control parameter is varied, the chaotic transient evolves to well-developed transient turbulence via a cascade of fractal-fractal metamorphoses. The edge state responsible for the edge of chaos and the genesis of turbulence is an unstable travelling wave in the laboratory frame, corresponding to a saddle point lying at the basin boundary in the Fourier space.

  10. Adobe Edge Animate CC for dummies

    CERN Document Server

    Rohde, Michael

    2013-01-01

    The easy way to build HTML5 mobile and web apps using Adobe's new Edge Animate CC Edge Animate CC is an approachable WYSIWYG alternative for leveraging the power of languages like HTML5, CSS3, and JavaScript to design and develop for the web and mobile devices, even if you have no programming experience. Written by Michael Rohde, the book calls on this seasoned web developer's wealth of experience using Edge Animate CC, and a companion website includes all code from the book to help you apply what you learn as you go. Features an easy-to-use interface, with a propert

  11. Image Edge Extraction via Fuzzy Reasoning

    Science.gov (United States)

    Dominquez, Jesus A. (Inventor); Klinko, Steve (Inventor)

    2008-01-01

    A computer-based technique for detecting edges in gray level digital images employs fuzzy reasoning to analyze whether each pixel in an image is likely on an edge. The image is analyzed on a pixel-by-pixel basis by analyzing gradient levels of pixels in a square window surrounding the pixel being analyzed. An edge path passing through the pixel having the greatest intensity gradient is used as input to a fuzzy membership function, which employs fuzzy singletons and inference rules to assigns a new gray level value to the pixel that is related to the pixel's edginess degree.

  12. Edge transport barriers in magnetic fusion plasmas

    International Nuclear Information System (INIS)

    The present level of understanding of the physics of the formation and sustainment of edge transport barriers in magnetically confined fusion plasmas is presented. The formation of edge transport barriers is studied through evolution of mechanisms which can suppress plasma turbulence and so reduce turbulent driven transport, such as E x B flow shear stabilization of turbulence. Comparisons of theoretical studies with experimental results are described including investigations of zonal flows, which are considered important for saturation and self-regulation of turbulence and turbulence-driven transport. Processes that affect the dynamics and spatial structure of the edge barrier are described with emphasis on the width of the transport barrier. (authors)

  13. Flat-band engineering of mobility edges

    Science.gov (United States)

    Danieli, Carlo; Bodyfelt, Joshua D.; Flach, Sergej

    2015-06-01

    Properly modulated flat-band lattices have a divergent density of states at the flat-band energy. Quasiperiodic modulations are known to host a metal-insulator transition already in one space dimension. Their embedding into flat-band geometries consequently allows for a precise engineering and fine tuning of mobility edges. We obtain analytic expressions for singular mobility edges for two flat-band lattice examples. In particular, we engineer cases with arbitrarily small energy separations of mobility edge, zeroes, and divergencies.

  14. Edge-Disjoint Fibonacci Trees in Hypercube

    Directory of Open Access Journals (Sweden)

    Indhumathi Raman

    2014-01-01

    Full Text Available The Fibonacci tree is a rooted binary tree whose number of vertices admit a recursive definition similar to the Fibonacci numbers. In this paper, we prove that a hypercube of dimension h admits two edge-disjoint Fibonacci trees of height h, two edge-disjoint Fibonacci trees of height h-2, two edge-disjoint Fibonacci trees of height h-4 and so on, as subgraphs. The result shows that an algorithm with Fibonacci trees as underlying data structure can be implemented concurrently on a hypercube network with no communication latency.

  15. Edge-Matching Problems with Rotations

    DEFF Research Database (Denmark)

    Ebbesen, Martin; Fischer, Paul; Witt, Carsten

    2011-01-01

    Edge-matching problems, also called puzzles, are abstractions of placement problems with neighborhood conditions. Pieces with colored edges have to be placed on a board such that adjacent edges have the same color. The problem has gained interest recently with the (now terminated) Eternity II...... far. We show that some problems have polynomial time algorithms while others are NP-complete. Especially we show that allowing rotations in one-row puzzles makes the problem NP-hard. We moreover show that many commonly considered puzzles can be emulated by simple puzzles with quadratic pieces, so that...

  16. Actin based processes that could determine the cytoplasmic architecture of plant cells

    OpenAIRE

    Honing; Emons, A.M.C.; Ketelaar, M.J.

    2007-01-01

    Actin polymerisation can generate forces that are necessary for cell movement, such as the propulsion of a class of bacteria, including Listeria, and the protrusion of migrating animal cells. Force generation by the actin cytoskeleton in plant cells has not been studied. One process in plant cells that is likely to depend on actin-based force generation is the organisation of the cytoplasm. We compare the function of actin binding proteins of three well-studied mammalian models that depend on...

  17. XMCD under pressure at the Fe K edge on the energy dispersive beamline of the ESRF

    OpenAIRE

    Mathon, Olivier; Baudelet, Francois; Itié, Jean-Paul; Pasternak, Sébastien; Polian, Alain; Pascarelli, Sakura

    2004-01-01

    The present paper demonstrates the feasibility of X-ray Absorption Spectroscopy (XAS) and X-ray Magnetic Circular Dichroism (XMCD) at high pressure at the Fe-K edge on the ID24 energy dispersive beamline of the ESRF. In 3d transition metals, performing experiments at the hard X-ray K-edge rather than at the magnetically interesting soft X-ray L-edges represents, the only way to access the high pressure regime obtainable with Diamond Anvil Cells. The simultaneous availability of a local struct...

  18. Experimental observation of bulk and edge transport in photonic Lieb lattices

    CERN Document Server

    Guzman-Silva, D; Bandres, M A; Rechtsman, M C; Weimann, S; Nolte, S; Segev, M; Szameit, A; Vicencio, R A

    2014-01-01

    We analyze the transport of light in the bulk and at the edge of photonic Lieb lattices, whose unique feature is the existence of a flat band representing stationary states in the middle of the band structure that can form localized bulk states. We find that transport in bulk Lieb lattices is significantly affected by the particular excitation site within the unit cell, due to overlap with the flat band states. Additionally, we demonstrate the existence of new edge states in anisotropic Lieb lattices. These states arise due to a virtual defect at the lattice edges and are not described by the standard tight-binding model.

  19. Conservative interpolation of edge and face data on n dimensional structured grids using differential forms

    Science.gov (United States)

    Pletzer, Alexander; Fillmore, David

    2015-12-01

    Interpolation methods for edge and face centered data are described, which preserve line and area integrals under regridding. These interpolation methods complement the multilinear nodal and conservative interpolation methods, which are widely used in climate data processing and other areas. The presented interpolation schemes ensure that curl-free and divergence-free fields remain so after regridding. These edge and face conservative interpolation methods are suitable for general curvilinear structured grids, including those with singular points (poles). Support for masked (invalid) regions is implicitly provided by attaching (partial) line/surface integral field values to cell edges/faces.

  20. MR imaging of clear cell carcinoma of the ovary

    International Nuclear Information System (INIS)

    Magnetic resonance imaging findings are reported for 12 pathologically proven lesions of clear cell carcinoma (CCC) of the ovary in 11 women (mean age 50 years). T1- and T2-weighted MR images were obtained in all patients, and gadolinium-enhanced MR images were obtained in 9. The mean diameter of the tumors was 13 cm. Seven patients presented with stage-I tumors. All 12 lesions consisted of cystic masses with solid protrusions occurring in 10 and solid masses in 2. The cysts were unilocular in 9 lesions and multilocular in 1. In four lesions, the cysts displayed with high intensity on T1-weighted images. Round solid protrusions were identified in 8 lesions. In 5 lesions, the number of protrusions was only a few. The solid portions of 5 masses had slightly high-intensity regions on T1-weighted images. The number of patients with ascites was three. Magnetic resonance imaging of CCC usually shows a unilocular large cyst with solid protrusions, which are often round and few in number. Such MR imaging findings suggest malignant tumor but are not specific. (orig.)

  1. Impact of edge electric fields on particle transport and dynamics in tokamaks

    International Nuclear Information System (INIS)

    Three aspects of tokamak edge physics are addressed. Role of radial electric field and poloidal rotation at the L-H transition is investigated with the Monte Carlo code ASCOT. Ripple ions and their use in measuring edge electric field are studied. Generation of fast electrons and hot spots in the lower hybrid grill region by the RF electric field is investigated with particle-in-cell simulations. (author)

  2. Ergodic divertor impact on Tore Supra edge

    International Nuclear Information System (INIS)

    The present ergodic divertor experiments in Tore Supra have been devoted to benchmarking the operational regimes of the apparatus. Two major effects are reported: on the one hand, strong changes occur in the ergodized boundary layer (up to 20% of the minor radius), and on the other hand, the central plasma and especially the confinement is not directly affected, i.e. the observed modifications are induced by edge effects. The basic trends, which are recorded are a decrease of both the edge electronic temperature and the edge density gradient while the radiated power is increased at the very edge of the ergodic region. The latter feature is in agreement with the impurity line emission characterized by an increase of the peripheral lines with a strong decrease of the central lines. (orig.)

  3. Strain imaging by Bragg edge neutron transmission

    CERN Document Server

    Santisteban, J R; Fitzpatrick, M E; Steuwer, A; Withers, P J; Daymond, M R; Johnson, M W; Rhodes, N; Schooneveld, E M

    2002-01-01

    The Bragg edges appearing in the transmitted time-of-flight spectra of polycrystalline materials have been recorded using a two-dimensional array of detectors. Subsequent analysis has enabled maps of the elastic strain to be produced.

  4. Fast Edge-Searching and Related Problems

    Science.gov (United States)

    Yang, Boting

    Given a graph G = (V,E) in which a fugitive hides on vertices or along edges, graph searching problems are usually to find the minimum number of searchers required to capture the fugitive. In this paper, we consider the problem of finding the minimum number of steps to capture the fugitive. We introduce the fast edge-searching problem in the edge search model, which is the problem of finding the minimum number of steps (called the fast edge-search time) to capture the fugitive. We establish relations between the fast edge-search time and the fast search number. While the family of graphs whose fast search number is at most k is not minor-closed for any positive integer k ≥ 2, we show that the family of graphs whose fast edge-search time is at most k is minor-closed. We establish relations between the fast (edge-)searching and the node searching. These relations allow us to transform the problem of computing node search numbers to the problem of computing fast edge-search time or fast search numbers. Using these relations, we prove that the problem of deciding, given a graph G and an integer k, whether the fast (edge-)search number of G is less than or equal to k is NP-complete; and it remains NP-complete for Eulerian graphs. We also prove that the problem of determining whether the fast (edge-)search number of G is a half of the number of odd vertices in G is NP-complete; and it remains NP-complete for planar graphs with maximum degree 4. We present a linear time approximation algorithm for the fast edge-search time that always delivers solutions of at most (1+|V|-1/|E|+1) times the optimal value. This algorithm also gives us a tight upper bound on the fast search number of the graph. We also show a lower bound on the fast search number using the minimum degree and the number of odd vertices.

  5. Edge and core dynamics in harness

    International Nuclear Information System (INIS)

    Resistive kink oscillations in tokamak plasmas are usually treated as core localized events, yet there there are several mechanisms by which they may interact with the edge dynamics. This suggests that we may regulate edge oscillatory behaviour, or ELMs, by harnessing the natural or contrived sawtooth period and amplitude. In this work I investigate core-edge oscillatory entrainment through direct propagation of heat pulses, inductive coupling, and global higher order resonance effects. In the core of auxiliary heated tokamak plasmas the ineluctable rhythm of slow buildup and rapid conversion of potential energy governs electron and heat radial transport. The growth phase of the sawtooth is accompanied by significant reconnection, then during the collapse the temperature and density in the core fall dramatically. There is evidence from experiments in reversed field pinch devices that ensuing energy fluxes can affect flow shear and confinement at the edge. The basis for this study is the dynamical (BDS) model for edge plasma behavior that was derived from electrostatic resistive MHD equations. The BDS model reflects the major qualitative features of edge dynamics that have been observed, such as L-H transitions and associated ELMs, hysteresis, and spontaneous reversal of poloidal shear flow. Under poorly dissipative conditions the transient behavior of the model can exhibit period-doubling, blue-sky, homoclinic, and other exotic bifurcations. Thus we might ask questions such as: Is it possible to mode-lock the edge dynamics to the core sawteeth? Can we induce, or prevent, a change in direction of shear flow? What about MHD effects? Is core-edge communication one way or is there some feedback? In the simplest prototype for coupled core-edge dynamics I model the sawtooth crash as a periodic power input to the edge potential energy reservoir. This is effected by coupling the BDS model to the dynamical system u = u(1 - u2 - x2) - ωsx, x = x(1-u2 -x2) + ωsu, which has

  6. Magnetic quantum dots and magnetic edge states

    International Nuclear Information System (INIS)

    Starting with defining the magnetic edge state in a magnetic quantum dot, which becomes quite popular nowadays conjunction with a possible candidate for a high density memory device or spintronic materials, various magnetic nano-quantum structures are reviewed in detail. We study the magnetic edge states of the two dimensional electron gas in strong perpendicular magnetic fields. We find that magnetic edge states are formed along the boundary of the magnetic dot, which is formed by a nonuniform distribution of magnetic fields. These magnetic edge states circulate either clockwise or counterclockwise, depending on the number of missing flux quanta, and exhibit quite different properties, as compared to the conventional ones which are induced by electrostatic confinements in the quantum Hall system. We also find that a close relation between the quantum mechanical eigenstates and the classical trajectories in the magnetic dot. When a magnetic dot is located inside a quantum wire, the edge-channel scattering mechanism by the magnetic quantum dot is very different from that by electrostatic dots. Here, the magnetic dot is formed by two different magnetic fields inside and outside the dot. We study the ballistic edge-channel transport and magnetic edge states in this situation. When the inner field is parallel to the outer one, the two-terminal conductance is quantized and shows the features of a transmission barrier and a resonator. On the other hand, when the inner field is reversed, the conductance is not quantized and all channels can be completely reflected in some energy ranges. The difference between the above two cases results from the distinct magnetic confinements. We also describe successfully the edge states of magnetic quantum rings and others in detail

  7. Refining Nodes and Edges of State Machines

    OpenAIRE

    Hallerstede, Stefan; Snook, Colin

    2011-01-01

    State machines are hierarchical automata that are widely used to structure complex behavioural specifications. We develop two notions of refinement of state machines, node refinement and edge refinement. We compare the two notions by means of examples and argue that, by adopting simple conventions, they can be combined into one method of refinement. In the combined method, node refinement can be used to develop architectural aspects of a model and edge refinement to develop algorithmic aspect...

  8. Edge direction and the structure of networks

    OpenAIRE

    Foster, Jacob G.; Foster, David V.; Grassberger, Peter; Paczuski, Maya

    2009-01-01

    Directed networks are ubiquitous and are necessary to represent complex systems with asymmetric interactions---from food webs to the World Wide Web. Despite the importance of edge direction for detecting local and community structure, it has been disregarded in studying a basic type of global diversity in networks: the tendency of nodes with similar numbers of edges to connect. This tendency, called assortativity, affects crucial structural and dynamic properties of real-world networks, such ...

  9. Directed Percolation with a Wall or Edge

    OpenAIRE

    Frojdh, Per; Howard, Martin; Lauritsen, Kent B.

    1997-01-01

    We examine the effects of introducing a wall or edge into a directed percolation process. Scaling ansatzes are presented for the density and survival probability of a cluster in these geometries, and we make the connection to surface critical phenomena and field theory. The results of previous numerical work for a wall can thus be interpreted in terms of surface exponents satisfying scaling relations generalising those for ordinary directed percolation. New exponents for edge directed percola...

  10. Image Edge Detection Based on Oscillation

    Institute of Scientific and Technical Information of China (English)

    FAN Hong; WANG Zhi-jie

    2005-01-01

    A new method for image edge detection based on a pulse neural network is proposed in this paper. The network is locally connected. The external input of each neuron of the network is gray value of the corresponding pixel. The synchrony of the neuron and its neighbors is detected by detection neurons. The edge of the image can be read off at minima of the total activity of the detection neurons.

  11. The perceptual contrast of impossible shadow edges

    OpenAIRE

    Soranzo, Alessandro; Galmonte, Alessandra; Agostini, Tiziano

    2009-01-01

    Luminance ratios along shadow edges remain the same even when they cross reflectance borders. According to Gilchrist (1988, Perception & Psychophysics 43 415 ^ 424) this so-called ratio-invariance property is a crucial factor in the perception of shadows. However, Soranzo and Agostini (2004, Perception 33 1359 ^ 1368) suggested that in some conditions (named `impossible shadows'), a luminance pattern might still be perceived as a shadow even if the ratio-invariance property along its edge ...

  12. Face analysis using curve edge maps

    OpenAIRE

    Deboeverie, Francis; Veelaert, Peter; Philips, Wilfried

    2011-01-01

    This paper proposes an automatic and real-time system for face analysis, usable in visual communication applications. In this approach, faces are represented with Curve Edge Maps, which are collections of polynomial segments with a convex region. The segments are extracted from edge pixels using an adaptive incremental linear-time fitting algorithm, which is based on constructive polynomial fitting. The face analysis system considers face tracking, face recognition and facial feature detectio...

  13. Acoustic metamaterial for subwavelength edge detection

    OpenAIRE

    Molerón, Miguel; Daraio, Chiara

    2015-01-01

    Metamaterials have demonstrated the possibility to produce super-resolved images by restoring propagative and evanescent waves. However, for efficient information transfer, for example, in compressed sensing, it is often desirable to visualize only the fast spatial variations of the wave field (carried by evanescent waves), as the one created by edges or small details. Image processing edge detection algorithms perform such operation, but they add time and complexity to the ima...

  14. Integrated core-edge-divertor modeling studies

    International Nuclear Information System (INIS)

    An integrated calculation model for simulating the interaction of physics phenomena taking place in the plasma core, in the plasma edge and in the SOL and divertor of tokamaks has been developed and applied to study such interactions. The model synthesises a combination of numerical calculations (1) the power and particle balances for the core plasma, using empirical confinement scaling laws and taking into account radiation losses (2), the particle, momentum and power balances in the SOL and divertor, taking into account the effects of radiation and recycling neutrals, (3) the transport of feeling and recycling neutrals, explicitly representing divertor and pumping geometry, and (4) edge pedestal gradient scale lengths and widths, evaluation of theoretical predictions (5) confinement degradation due to thermal instabilities in the edge pedestals, (6) detachment and divertor MARFE onset, (7) core MARFE onsets leading to a H-L transition, and (8) radiative collapse leading to a disruption and evaluation of empirical fits (9) power thresholds for the L-H and H-L transitions and (10) the width of the edge pedestals. The various components of the calculation model are coupled and must be iterated to a self-consistent convergence. The model was developed over several years for the purpose of interpreting various edge phenomena observed in DIII-D experiments and thereby, to some extent, has been benchmarked against experiment. Because the model treats the interactions of various phenomena in the core, edge and divertor, yet is computationally efficient, it lends itself to the investigation of the effects of different choices of various edge plasma operating conditions on overall divertor and core plasma performance. Studies of the effect of feeling location and rate, divertor geometry, plasma shape, pumping and over 'edge parameters' on core plasma properties (line average density, confinement, density limit, etc.) have been performed for DIII-D model problems. A

  15. FACIAL EXPRESSION RECOGNITION BASED ON EDGE DETECTION

    OpenAIRE

    Chen, Xiaoming; Cheng, Wushan

    2015-01-01

    Relational Over the last two decades, the advances in computer vision and pattern recognition power have opened the door to new opportunity of automatic facial expression recognition system[1]. This paper use Canny edge detection method for facial expression recognition. Image color space transformation in the first place and then to identify and locate human face .Next pick up the edge of eyes and mouth's features extraction. Last we judge the facial expressions after compared wi...

  16. CRN2 enhances the invasiveness of glioblastoma cells

    OpenAIRE

    Ziemann, Anja; Hess, Simon; Bhuwania, Ridhirama; Linder, Stefan; Kloppenburg, Peter; Noegel, Angelika A; Clemen, Christoph S.

    2013-01-01

    Background Movement of tumor cells involves dynamic remodeling of the actin cytoskeleton, which is regulated by actin binding proteins, such as CRN2 (synonyms: coronin 1C, coronin 3). In vitro, CRN2 participates in secretion, matrix degradation, protrusion formation, and cell migration. Furthermore, expression of CRN2 correlates with the malignant phenotype of human diffuse gliomas. CRN2's effects on actin polymerization and F-actin bundling are abolished by protein kinase 2 (CK2) dependent p...

  17. EDGE SENSING DEMOSAICING USING ADAPTIVE WEIGHTED INTERPOLATION

    Directory of Open Access Journals (Sweden)

    Dev R. Newlin

    2013-01-01

    Full Text Available Demosaicing is a process of obtaining a full color image by interpolating the missing colors of an image captured from a digital still and video cameras that use a single-sensor array.The edges are not handled properly in the existing demosaicking methods. This study provides an effective demosaicing algorithm applying an adaptive weighted-edge interpolation to handle green pixels. Due to the introduction of adaptive threshold based on the high frequency information for the classification of edges and textures, the interpolation of edges is performed excellently. Adaptive weights depending on spatial and spectral correlation are assigned for interpolation on both edges and smooth region. A refinement scheme based on enhanced effective color interpolation is used to improve the red and blue interpolation to obtain better quality image. As compared with the latest demosaicing algorithms, the proposed algorithm produces the best average demosaicing performance both objectively and subjectively. This approach handles the edges in a proper way and reconstructs the color image with best peak signal to noise ratio.

  18. Understanding the dynamics of fractional edge states with composite fermions

    OpenAIRE

    Chklovskii, Dmitri B.; Halperin, Bertrand I.

    1996-01-01

    Fractional edge states can be viewed as integer edge states of composite fermions. We exploit this to discuss the conductance of the fractional quantized Hall states and the velocity of edge magnetoplasmons.

  19. Edge-Fault-Tolerant Edge-Bipancyclicity of Bubble-Sort Graphs

    Institute of Scientific and Technical Information of China (English)

    Xin Ping XU; Min XU; Jin JING

    2012-01-01

    The bubble-sort graph Bn is a bipartite graph.Kikuchi and Araki [Edge-bipancyclicity and edge-fault-tolerant bipancyclicity of bubble-sort graphs.Information Processing Letters,100,52-59 (2006)] have proved that Bn is edge-bipancyclic for n ≥ 5 and Bn - F is bipancyclic when n ≥ 4and |F| ≤ n - 3.In this paper,we improve this result by showing that for any edge set F of Bn with |F| ≤ n - 3,every edge of Bn - F lies on a cycle of every even length from 6 to n! for n ≥ 5 and every edge of Bn - F lies on a cycle of every even length from 8 to n! for n =4.

  20. A Shearlets-based Edge Identification Algorithem for Infrared Image

    OpenAIRE

    Rui-bin ZOU; Cai-cheng SHI

    2013-01-01

    A shearlets-based edge identification algorithem for infrared image is proposed. The algorithem demonstrates the performance of edge detection based on shearlets, combines with the edge hysteresis thresholding, designs steps of edge detection, which is proper to use in infrared images.Simultaneously, with the advantage of edge geometric features provided by the shearlets, infrared image were extracted the direction information of edge of Infrared image, and classified. In computer simulations...

  1. Image edge detection based on adaptive weighted morphology

    Institute of Scientific and Technical Information of China (English)

    Lihui Jiang; Yanying Guo

    2007-01-01

    A novel morphological edge detector based on adaptive weighted morphological operators is presented. It judges image edge and direction by adaptive weighted morphological structuring elements (SEs). If the edge direction exists, a big weight factor in SE is put; if it does not exist, a small weight factor in SE is put. Thus we can achieve an intensified edge detector. Experimental results prove that the new operator's performance dominates those of classical operators for images in edge detection, and obtains superbly detail edges.

  2. Edge State and Intrinsic Hole Doping in Bilayer Phosphorene

    OpenAIRE

    Osada, Toshihito

    2014-01-01

    Using a simple LCAO model by Harrison, we have qualitatively studied the edge state of bilayer phosphorene, which is a unit structure of the layered crystal of black phosphorus. This model successfully reproduces the isolated edge state in the bulk gap in monolayer phosphorene. In bilayer phosphorene, however, it shows that edge states are almost buried in the valence band and there is no isolated midgap edge state at the zigzag edge. Since the buried edge state works as acceptor, holes are d...

  3. Losing your edge: climate change and the conservation value of range‐edge populations

    OpenAIRE

    Evan M. Rehm; Olivas, Paulo; Stroud, James; Feeley, Kenneth J.

    2015-01-01

    Abstract Populations occurring at species' range edges can be locally adapted to unique environmental conditions. From a species' perspective, range‐edge environments generally have higher severity and frequency of extreme climatic events relative to the range core. Under future climates, extreme climatic events are predicted to become increasingly important in defining species' distributions. Therefore, range‐edge genotypes that are better adapted to extreme climates relative to core populat...

  4. Distance to edges, edge contrast and landscape fragmentation: interactions affecting farmland birds arounf forest plantations

    OpenAIRE

    Fabião, António; Reino, Luís; Osborne, Patrick E.; Beja, Pedro; Morgado, Rui; Rotenberry, John T

    2009-01-01

    Afforestation often causes direct habitat losses for farmland birds of conservation concern, but it is uncertain whether negative effects also extend significantly into adjacent open land. Information is thus required on how these species react to wooded edges, and how their responses are affected by edge and landscape characteristics. These issues were examined in Mediterranean arable farmland, using bird counts at 0, 100, 200, 300 and >300 m from oak, pine and eucalyptus edge...

  5. Flap-edge aeroacoustic measurements and predictions

    Science.gov (United States)

    Brooks, Thomas F.; Humphreys, William M.

    2003-03-01

    An aeroacoustic model test has been conducted to investigate the mechanisms of sound generation on high-lift wing configurations. This paper presents an analysis of flap side-edge noise, which is often the most dominant source. A model of a main element wing section with a half-span flap was tested at low speeds of up to a Mach number of 0.17, corresponding to a wing chord Reynolds number of approximately 1.7 million. Results are presented for flat (or blunt), flanged, and round flap-edge geometries, with and without boundary-layer tripping, deployed at both moderate and high flap angles. The acoustic database is obtained from a small aperture directional array (SADA) of microphones, which was constructed to electronically steer to different regions of the model and to obtain farfield noise spectra and directivity from these regions. The basic flap-edge aerodynamics is established by static surface pressure data, as well as by computational fluid dynamics (CFD) calculations and simplified edge flow analyses. Distributions of unsteady pressure sensors over the flap allow the noise source regions to be defined and quantified via cross-spectral diagnostics using the SADA output. It is found that shear layer instability and related pressure scatter is the primary noise mechanism. For the flat edge flap, two noise prediction methods based on unsteady-surface-pressure measurements are evaluated and compared to measured noise. One is a new causality spectral approach developed here. The other is a new application of an edge-noise scatter prediction method. The good comparisons for both approaches suggest that the prediction models capture much of the physics. Areas of disagreement appear to reveal when the assumed edge noise mechanism does not fully define the noise production. For the different edge conditions, extensive spectra and directivity are presented. The complexity of the directivity results demonstrate the strong role of edge source geometry and frequency in

  6. Plasma-materials interactions and edge-plasma physics research

    International Nuclear Information System (INIS)

    This report discusses the: Pisces Program; Pisces Facilities; Pisces Experiments: Materials and Surface Physics; Pisces Experiments: Edge Plasma Physics; and, Theoretical Analysis: Edge Plasma Behavior

  7. Hopfield neural network and its applications on image edge detection

    Institute of Scientific and Technical Information of China (English)

    Yonghong Zhang(张永宏); Dejin Hu(胡德金); Kai Zhang(张凯); Junjie Xu(徐俊杰)

    2004-01-01

    A method of image edge detection using the Hopfield neural network (HNN) is proposed in this paper.The image edge parameters are introduced in detail, and the energy function of HNN is given based on the edge parameters. Tests on the image edge detection show that images detected by the proposed method have good edge closeness and true edge, at the same time it has good anti-noise performance. The image edge detection using HNN is better than that obtained by some other edge detection operators.

  8. Losing your edge: climate change and the conservation value of range-edge populations.

    Science.gov (United States)

    Rehm, Evan M; Olivas, Paulo; Stroud, James; Feeley, Kenneth J

    2015-10-01

    Populations occurring at species' range edges can be locally adapted to unique environmental conditions. From a species' perspective, range-edge environments generally have higher severity and frequency of extreme climatic events relative to the range core. Under future climates, extreme climatic events are predicted to become increasingly important in defining species' distributions. Therefore, range-edge genotypes that are better adapted to extreme climates relative to core populations may be essential to species' persistence during periods of rapid climate change. We use relatively simple conceptual models to highlight the importance of locally adapted range-edge populations (leading and trailing edges) for determining the ability of species to persist under future climates. Using trees as an example, we show how locally adapted populations at species' range edges may expand under future climate change and become more common relative to range-core populations. We also highlight how large-scale habitat destruction occurring in some geographic areas where many species range edge converge, such as biome boundaries and ecotones (e.g., the arc of deforestation along the rainforest-cerrado ecotone in the southern Amazonia), can have major implications for global biodiversity. As climate changes, range-edge populations will play key roles in helping species to maintain or expand their geographic distributions. The loss of these locally adapted range-edge populations through anthropogenic disturbance is therefore hypothesized to reduce the ability of species to persist in the face of rapid future climate change. PMID:26664681

  9. Edge localized modes control by resonant magnetic perturbations

    International Nuclear Information System (INIS)

    The present work is dedicated to one of the most promising methods of control of the ELMs (Edge Localized Modes), based on a system of coils producing Resonant Magnetic Perturbations (RMPs). Our main objectives are, on the one hand, to improve the physical understanding of the mechanisms at play, and on the other hand to propose a concrete design of ELMs control coils for ITER. In order to calculate and analyze the magnetic perturbations produced by a given set of coils, we have developed the ERGOS code. The first ERGOS calculation was for the DIII-D ELMs control coils, the I-coils. It showed that they produce magnetic islands chains which overlap at the edge of the plasma, resulting in the ergodization of the magnetic field. We have then used ERGOS for the modelling of the experiments on ELMs control using the error field correction coils at JET and MAST. In the case of JET, we have shown the existence of a correlation between the mitigation of the ELMs and the ergodization of the magnetic field at the edge, in agreement with the DIII-D result. In order to design the ELMs control coils for ITER we have used ERGOS intensively, taking the case of the DIII-D I-coils as a reference. Three candidate designs came out, which we presented at the ITER Design Review, in 2007. Recently, the ITER management decided to provide a budget for building ELMs control coils, the design of which remains to be chosen between two of the three options that we proposed. Finally, in order to understand better the non-linear magnetohydrodynamics phenomena taking place in ELMs control by RMPs, we performed numerical simulations, in particular with the JOREK code for a DIII-D case. The simulations reveal the existence of convection cells induced at the edge by the magnetic perturbations, and the possible screening of the RMPs in presence of rotation

  10. Partnership for Edge Physics Simulation (EPSI)

    Energy Technology Data Exchange (ETDEWEB)

    Schroder, Peter [California Inst. of Technology, Pasadena, CA (United States)

    2015-02-11

    We propose to develop advanced simulation codes, based upon an extreme parallelism, first principles kinetic approach, to address the challenges associated with the edge region of magnetically confined plasmas. This work is relevant to both existing magnetic fusion facilities and essential for next-generation burning plasma experiments, such as ITER where success is critically dependent upon H-mode operation achieving an edge pedestal of sufficient height for good core plasma performance without producing deleterious large scale edge localized instabilities. The plasma edge presents a well-known set of multi-physics, multi-scale problems involving complex 3D magnetic geometry. Perhaps the greatest computational challenge is the lack of scale separation – temporal scales for drift waves, Alfven waves, ELM dynamics for example have strong overlap. Similar overlap occurs on the spatial scales for the ion poloidal gyro-radius, drift wave and pedestal width. The traditional approach of separating fusion problems into weakly interacting spatial or temporal domains clearly breaks down in the edge. A full kinetic model (full-f model) must be solved to understand and predict the edge physics including non-equilibrium thermodynamic issues arising from the magnetic topology (the open field lines producing a spatially sensitive velocity hole), plasma wall interactions, neutral and atomic physics. The plan here is to model these phenomena within a comprehensive first principles set of equations without the need for the insurmountable multiple-codes coupling issues by building on the XGC1 code developed under the SciDAC Proto-FSP Center for Plasma Edge Simulation (CPES). This proposal includes the critical participants in the XGC1 development. We propose enhancing the capability of XGC1 by including all the important turbulence physics contained in kinetic ion and electron electromagnetic dynamics, by extending the PIC technology to incorporate several positive features found

  11. Flap Edge Aeroacoustic Measurements and Predictions

    Science.gov (United States)

    Brooks, Thomas F.; Humphreys, William M., Jr.

    2000-01-01

    An aeroacoustic model test has been conducted to investigate the mechanisms of sound generation on high-lift wing configurations. This paper presents an analysis of flap side-edge noise, which is often the most dominant source. A model of a main element wing section with a half-span flap was tested at low speeds of up to a Mach number of 0.17, corresponding to a wing chord Reynolds number of approximately 1.7 million. Results are presented for flat (or blunt), flanged, and round flap-edge geometries, with and without boundary-layer tripping, deployed at both moderate and high flap angles. The acoustic database is obtained from a Small Aperture Directional Array (SADA) of microphones, which was constructed to electronically steer to different regions of the model and to obtain farfield noise spectra and directivity from these regions. The basic flap-edge aerodynamics is established by static surface pressure data, as well as by Computational Fluid Dynamics (CFD) calculations and simplified edge flow analyses. Distributions of unsteady pressure sensors over the flap allow the noise source regions to be defined and quantified via cross-spectral diagnostics using the SADA output. It is found that shear layer instability and related pressure scatter is the primary noise mechanism. For the flat edge flap, two noise prediction methods based on unsteady surface pressure measurements are evaluated and compared to measured noise. One is a new causality spectral approach developed here. The other is a new application of an edge-noise scatter prediction method. The good comparisons for both approaches suggest that much of the physics is captured by the prediction models. Areas of disagreement appear to reveal when the assumed edge noise mechanism does not fully define the noise production. For the different edge conditions, extensive spectra and directivity are presented. Significantly, for each edge configuration, the spectra for different flow speeds, flap angles, and

  12. Image enhancement based on edge boosting algorithm

    Science.gov (United States)

    Ngernplubpla, Jaturon; Chitsobhuk, Orachat

    2015-12-01

    In this paper, a technique for image enhancement based on proposed edge boosting algorithm to reconstruct high quality image from a single low resolution image is described. The difficulty in single-image super-resolution is that the generic image priors resided in the low resolution input image may not be sufficient to generate the effective solutions. In order to achieve a success in super-resolution reconstruction, efficient prior knowledge should be estimated. The statistics of gradient priors in terms of priority map based on separable gradient estimation, maximum likelihood edge estimation, and local variance are introduced. The proposed edge boosting algorithm takes advantages of these gradient statistics to select the appropriate enhancement weights. The larger weights are applied to the higher frequency details while the low frequency details are smoothed. From the experimental results, the significant performance improvement quantitatively and perceptually is illustrated. It can be seen that the proposed edge boosting algorithm demonstrates high quality results with fewer artifacts, sharper edges, superior texture areas, and finer detail with low noise.

  13. Trailing edge modifications for flatback airfoils.

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, Daniel L. (University of California, Davis, CA); van Dam, C.P. (University of California, Davis, CA); Berg, Dale E.

    2008-03-01

    The adoption of blunt trailing edge airfoils (also called flatback airfoils) for the inboard region of large wind turbine blades has been proposed. Blunt trailing edge airfoils would not only provide a number of structural benefits, such as increased structural volume and ease of fabrication and handling, but they have also been found to improve the lift characteristics of thick airfoils. Therefore, the incorporation of blunt trailing edge airfoils would allow blade designers to more freely address the structural demands without having to sacrifice aerodynamic performance. These airfoils do have the disadvantage of generating high levels of drag as a result of the low-pressure steady or periodic flow in the near-wake of the blunt trailing edge. Although for rotors, the drag penalty appears secondary to the lift enhancement produced by the blunt trailing edge, high drag levels are of concern in terms of the negative effect on the torque and power generated by the rotor. Hence, devices are sought that mitigate the drag of these airfoils. This report summarizes the literature on bluff body vortex shedding and bluff body drag reduction devices and proposes four devices for further study in the wind tunnel.

  14. Edge states of zigzag bilayer graphite nanoribbons

    Science.gov (United States)

    Rhim, Jun-Won; Moon, Kyungsun

    2008-09-01

    The electronic structures of zigzag bilayer graphite nanoribbons (Z-BGNRs) with various ribbon widths N are studied within the tight binding approximation. Neglecting the inter-layer hopping amplitude γ4, which is an order of magnitude smaller than the other inter-layer hopping parameters, there exist two fixed Fermi points ± k* independent of the ribbon width with a peculiar energy dispersion near k* as ɛ(k)~ ± (k-k*)N. By investigating the edge states of Z-BGNRs, we notice that the trigonal warping of the bilayer graphene sheets is reflected in the edge state structure. With the inclusion of γ4, the above two Fermi points are not fixed but drift toward the vicinity of the Dirac point with increasing width N, as shown by the finite scaling method, and the peculiar dispersions change to parabolic ones. The edge magnetism of Z-BGNRs is also examined by solving the half-filled Hubbard Hamiltonian for the ribbon using the Hartree-Fock approximation. We have shown that within the same side of the edges, the edge spins are aligned ferromagnetically for the experimentally relevant set of parameters.

  15. Edge states of zigzag bilayer graphite nanoribbons

    Energy Technology Data Exchange (ETDEWEB)

    Rhim, Jun-Won; Moon, Kyungsun [Department of Physics and Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of)], E-mail: kmoon@yonsei.ac.kr

    2008-09-10

    The electronic structures of zigzag bilayer graphite nanoribbons (Z-BGNRs) with various ribbon widths N are studied within the tight binding approximation. Neglecting the inter-layer hopping amplitude {gamma}{sub 4}, which is an order of magnitude smaller than the other inter-layer hopping parameters, there exist two fixed Fermi points {+-} k{sup *} independent of the ribbon width with a peculiar energy dispersion near k{sup *} as {epsilon}(k){approx} {+-} (k-k{sup *}){sup N}. By investigating the edge states of Z-BGNRs, we notice that the trigonal warping of the bilayer graphene sheets is reflected in the edge state structure. With the inclusion of {gamma}{sub 4}, the above two Fermi points are not fixed but drift toward the vicinity of the Dirac point with increasing width N, as shown by the finite scaling method, and the peculiar dispersions change to parabolic ones. The edge magnetism of Z-BGNRs is also examined by solving the half-filled Hubbard Hamiltonian for the ribbon using the Hartree-Fock approximation. We have shown that within the same side of the edges, the edge spins are aligned ferromagnetically for the experimentally relevant set of parameters.

  16. Control of cell behavior on PTFE surface using ion beam irradiation

    International Nuclear Information System (INIS)

    A polytetrafluoroethylene (PTFE) surface is smooth and biologically inert, so that cells cannot attach to it. Ion beam irradiation of the PTFE surface forms micropores and a melted layer, and the surface is finally covered with a large number of small protrusions. Recently, we found that cells could adhere to this irradiated PTFE surface and spread over the surface. Because of their peculiar attachment behavior, these surfaces can be used as biological tools. However, the factors regulating cell adhesion are still unclear, although some new functional groups formed by irradiation seem to contribute to this adhesion. To control cell behavior on PTFE surfaces, we must determine the effects of the outermost irradiated surface on cell adhesion. In this study, we removed the thin melted surface layer by postirradiation annealing and investigated cell behavior on the surface. On the surface irradiated with 3 x 1016 ions/cm2, cells spread only on the remaining parts of the melted layer. From these results, it is clear that the melted layer had a capacity for cell attachment. When the surface covered with protrusions was irradiated with a fluence of 1 x 1017 ions/cm2, the distribution of cells changed after the annealing process from 'sheet shaped' into multicellular aggregates with diameters of around 50 μm. These results indicate that we can control cell behavior on PTFE surfaces covered with protrusions using irradiation and subsequent annealing. Multicellular spheroids can be fabricated for tissue engineering using this surface.

  17. The GIT–PIX complexes regulate the chemotactic response of rat basophilic leukaemia cells

    OpenAIRE

    Gavina, Manuela; Za, Lorena; Molteni, Raffaella; Pardi, Ruggero; Curtis, Ivan de

    2010-01-01

    Background information. Cell motility entails the reorganization of the cytoskeleton and membrane trafficking for effective protrusion. The GIT–PIX protein complexes are involved in the regulation of cell motility and adhesion and in the endocytic traffic of members of the family of G-protein-coupled receptors. We have investigated the function of the endogenous GIT complexes in the regulation of cell motility stimulated by fMLP (formyl-Met-Leu-Phe) peptide, in a rat basophilic leukaemia RBL-...

  18. Spanwise visualization of the flow around a three-dimensional foil with leading edge protuberances

    Science.gov (United States)

    Stanway, M. J.; Techet, A. H.

    2006-11-01

    Studies of model humpback whale fins have shown that leading edge protuberances, or tubercles, can lead to delayed stall and increased lift at higher angles of attack, compared to foils with geometrically smooth leading edges. Such enhanced performance characteristics could prove highly useful in underwater vehicles such as gliders or long range AUVs (autonomous underwater vehicles). In this work, Particle Imaging Velocimetry (PIV) is performed on two static wings in a water tunnel over a range of angles of attack. These three- dimensional, finite-aspect ratio wings are modeled after a humpback whale flipper and are identical in shape, tapered from root to tip, except for the leading edge. In one of the foils the leading edge is smooth, whereas in the other, regularly spaced leading edge bumps are machined to simulate the whale’s fin tubercles. Results from these PIV tests reveal distinct cells where coherent flow structures are destroyed as a result of the leading edge perturbations. Tests are performed at Reynolds numbers Re ˜ O(10^5), based on chordlength, in a recirculating water tunnel. An inline six-axis load cell is mounted to measure the forces on the foil over a range of static pitch angles. It is hypothesized that this spanwise breakup of coherent vortical structures is responsible for the delayed angle of stall. These quantitative experiments complement exiting qualitative studies with two dimensional foils.

  19. Listeria monocytogenes exploits efferocytosis to promote cell-to-cell spread.

    Science.gov (United States)

    Czuczman, Mark A; Fattouh, Ramzi; van Rijn, Jorik M; Canadien, Veronica; Osborne, Suzanne; Muise, Aleixo M; Kuchroo, Vijay K; Higgins, Darren E; Brumell, John H

    2014-05-01

    Efferocytosis, the process by which dying or dead cells are removed by phagocytosis, has an important role in development, tissue homeostasis and innate immunity. Efferocytosis is mediated, in part, by receptors that bind to exofacial phosphatidylserine (PS) on cells or cellular debris after loss of plasma membrane asymmetry. Here we show that a bacterial pathogen, Listeria monocytogenes, can exploit efferocytosis to promote cell-to-cell spread during infection. These bacteria can escape the phagosome in host cells by using the pore-forming toxin listeriolysin O (LLO) and two phospholipase C enzymes. Expression of the cell surface protein ActA allows L. monocytogenes to activate host actin regulatory factors and undergo actin-based motility in the cytosol, eventually leading to formation of actin-rich protrusions at the cell surface. Here we show that protrusion formation is associated with plasma membrane damage due to LLO's pore-forming activity. LLO also promotes the release of bacteria-containing protrusions from the host cell, generating membrane-derived vesicles with exofacial PS. The PS-binding receptor TIM-4 (encoded by the Timd4 gene) contributes to efficient cell-to-cell spread by L. monocytogenes in macrophages in vitro and growth of these bacteria is impaired in Timd4(-/-) mice. Thus, L. monocytogenes promotes its dissemination in a host by exploiting efferocytosis. Our results indicate that PS-targeted therapeutics may be useful in the fight against infections by L. monocytogenes and other bacteria that use similar strategies of cell-to-cell spread during infection. PMID:24739967

  20. Localized Edge Vibrations and Edge Reconstruction by Joule Heating in Graphene Nanostructures

    DEFF Research Database (Denmark)

    Engelund, Mads; Fürst, Joachim Alexander; Jauho, Antti-Pekka;

    2010-01-01

    Control of the edge topology of graphene nanostructures is critical to graphene-based electronics. A means of producing atomically smooth zigzag edges using electronic current has recently been demonstrated in experiments [Jia et al., Science 323, 1701 (2009)]. We develop a microscopic theory for...

  1. Study of airfoil trailing edge bluntness noise

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Shen, Wen Zhong; Sørensen, Jens Nørkær

    This paper deals with airfoil trailing edge noise with special focus on airfoils with blunt trailing edges. Two methods are employed to calculate airfoil noise: The flow/acoustic splitting method and the semi-empirical method. The flow/acoustic splitting method is derived from compressible Navier......-Stokes equations. It provides us possibilities to study details about noise generation mechanism. The formulation of the semi-empirical model is based on acoustic analogy and then curve-fitted with experimental data. Due to its high efficiency, such empirical relation is used for purpose of low noise airfoil...... design or optimization. Calculations from both methods are compared with exist experiments. The airfoil blunt noise is found as a function of trailing edge bluntness, Reynolds number, angle of attack, etc....

  2. Black phosphorus edges: a polarized Raman study

    Science.gov (United States)

    Ribeiro, H.; Villegas, C.; Bahamon, D.; Castro Neto, A.; de Souza, E.; Rocha, A.; Pimenta, M.; de Matos, C.

    Black phosphorus (BP) has been recently exfoliated down to few-layer thicknesses revealing numerous interesting features such as a tunable direct bandgap. Ever since, demonstrations of BP electronic devices have bloomed, as well as studies of the electric, optical, mechanical and thermal properties of its bulk and few-layer forms. However, the edges of BP crystals have, so far, been poorly characterized, even though the terminations of layered crystals are known to possess a range of interesting properties. In this work, the edges of exfoliated BP flakes are characterized by polarized confocal Raman spectroscopy. We will present experimental Raman spectra at zigzag and armchair edges, as well as density functional theory calculations that explain the peculiarities of the experimental data. Fapesp, INCT/Nanocarbono, Fapemig, CNPq, MackPesquisa, Grid-Unesp, CENAPAD-SP, and NRF.

  3. Predictability of the Arctic sea ice edge

    Science.gov (United States)

    Goessling, H. F.; Tietsche, S.; Day, J. J.; Hawkins, E.; Jung, T.

    2016-02-01

    Skillful sea ice forecasts from days to years ahead are becoming increasingly important for the operation and planning of human activities in the Arctic. Here we analyze the potential predictability of the Arctic sea ice edge in six climate models. We introduce the integrated ice-edge error (IIEE), a user-relevant verification metric defined as the area where the forecast and the "truth" disagree on the ice concentration being above or below 15%. The IIEE lends itself to decomposition into an absolute extent error, corresponding to the common sea ice extent error, and a misplacement error. We find that the often-neglected misplacement error makes up more than half of the climatological IIEE. In idealized forecast ensembles initialized on 1 July, the IIEE grows faster than the absolute extent error. This means that the Arctic sea ice edge is less predictable than sea ice extent, particularly in September, with implications for the potential skill of end-user relevant forecasts.

  4. Controllable edge feature sharpening for dental applications.

    Science.gov (United States)

    Fan, Ran; Jin, Xiaogang

    2014-01-01

    This paper presents a new approach to sharpen blurred edge features in scanned tooth preparation surfaces generated by structured-light scanners. It aims to efficiently enhance the edge features so that the embedded feature lines can be easily identified in dental CAD systems, and to avoid unnatural oversharpening geometry. We first separate the feature regions using graph-cut segmentation, which does not require a user-defined threshold. Then, we filter the face normal vectors to propagate the geometry from the smooth region to the feature region. In order to control the degree of the sharpness, we propose a feature distance measure which is based on normal tensor voting. Finally, the vertex positions are updated according to the modified face normal vectors. We have applied the approach to scanned tooth preparation models. The results show that the blurred edge features are enhanced without unnatural oversharpening geometry. PMID:24741376

  5. Exploring topological edge states in photonic quasicrystals

    CERN Document Server

    Baboux, F; Lemaître, A; Gomez, C; Galopin, E; Gratiet, L Le; Sagnes, I; Amo, A; Bloch, J; Akkermans, E

    2016-01-01

    We experimentally investigate the topological properties of quasiperiodic chains using cavity polaritons confined in a potential following the Fibonacci sequence. Edge states forming in the gaps of a fractal energy spectrum are imaged both in real and momentum space. These edge states periodically traverse the gaps when varying a structural degree of freedom $\\phi$ of the Fibonacci sequence. The period and direction of the traverses are directly related to the Chern numbers assigned to each gap by the gap-labeling theorem. Additionally, we show that the Chern numbers determine the spatial symmetry properties of the edge states. These results highlight the potential of cavity polaritons to emulate nontrivial topological properties in a controlled environment.

  6. Acoustic metamaterial for subwavelength edge detection

    Science.gov (United States)

    Molerón, Miguel; Daraio, Chiara

    2015-08-01

    Metamaterials have demonstrated the possibility to produce super-resolved images by restoring propagative and evanescent waves. However, for efficient information transfer, for example, in compressed sensing, it is often desirable to visualize only the fast spatial variations of the wave field (carried by evanescent waves), as the one created by edges or small details. Image processing edge detection algorithms perform such operation, but they add time and complexity to the imaging process. Here we present an acoustic metamaterial that transmits only components of the acoustic field that are approximately equal to or smaller than the operating wavelength. The metamaterial converts evanescent waves into propagative waves exciting trapped resonances, and it uses periodicity to attenuate the propagative components. This approach achieves resolutions ~5 times smaller than the operating wavelength and makes it possible to visualize independently edges aligned along different directions.

  7. Mesh Simplification Using the Edge Attributes

    Directory of Open Access Journals (Sweden)

    Il Dong Yun

    2002-10-01

    Full Text Available This paper presents a novel technique for simplifying a triangulated surface at different levels of resolution. While most existing algorithms, based on iterative vertex decimation, employ the distance for error metric, the proposed algorithm utilizes an edge criterion for removing a vertex. An interior angle of a vertex is defined as the maximum value of all possible angles formed by combinations of edges connected to a vertex. Since the surface curvature examined with the interior angle provides more information for decision of vertex removal than the conventional distance measure, the proposed algorithm can approximate the surface with less computation. The height of a triangle, which is formed by the pair of edges, is also used for an additional constraint. The computational complexity can thus be greatly alleviated to logarithmic scale from the exponential scale required for the conventional algorithms, while yielding the comparable error level.

  8. AUTOMATED EDGE DETECTION USING CONVOLUTIONAL NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    Mohamed A. El-Sayed

    2013-11-01

    Full Text Available The edge detection on the images is so important for image processing. It is used in a various fields of applications ranging from real-time video surveillance and traffic management to medical imaging applications. Currently, there is not a single edge detector that has both efficiency and reliability. Traditional differential filter-based algorithms have the advantage of theoretical strictness, but require excessive post-processing. Proposed CNN technique is used to realize edge detection task it takes the advantage of momentum features extraction, it can process any input image of any size with no more training required, the results are very promising when compared to both classical methods and other ANN based methods

  9. Edge effects in composites by moire interferometry

    Science.gov (United States)

    Czarnek, R.; Post, D.; Herakovich, C.

    1983-01-01

    The very high sensitivity of moire interferometry has permitted the present edge effect experiments to be conducted at a low average stress and strain level, assuring linear and elastic behavior in the composite material samples tested. Sensitivity corresponding to 2450 line/mm moire was achieved with a 0.408 micron/fringe. Simultaneous observations of the specimen face and edge displacement fields showed good fringe definition despite the 1-mm thickness of the specimens and the high gradients, and it is noted that the use of a carrier pattern and optical filtering was effective in even these conditions. Edge effects and dramatic displacement gradients were confirmed in angle-ply composite laminates.

  10. Free edge effects in laminated composites

    Science.gov (United States)

    Herakovich, C. T.

    1989-01-01

    The fundamental mechanics of free-edge effects in laminated fiber-reinforced composites is examined, reviewing the results of recent experimental and analytical investigations. The derivation of the governing equations for the basic problem is outlined, including the equilibrium and mismatch conditions and the elasticity formulation, and experimental data on axial displacement and shear strain in angle-ply laminates are summarized. Numerical predictions of free-edge deformation and interlaminar and through-thickness stress distributions are presented for cross-ply, angle-ply, and quasi-isotropic laminates, and the mechanisms of edge damage and failure in angle-ply laminates are briefly characterized. Extensive diagrams, drawings, graphs, and photographs are provided.

  11. Clinical Study of Micro-implant Treatment for Dental Arch Protrusion%微型种植体支抗治疗上牙弓前突的临床研究

    Institute of Scientific and Technical Information of China (English)

    张俊峰

    2011-01-01

    目的:研究微型种植体作为强支抗解决上牙弓前突的有效性.方法:选择严重上牙弓前突的患者12例,减数拔除上颌双侧第一前磨牙,种植体植入上颌第一磨牙和第二前磨之间膜龈结合处,以滑动法整体内收6颗上前牙.通过X线头颅定位侧位片的测量方法,观察切牙和磨牙的位置变化.结果:牙弓突度均得到明显改善,治疗后上颌切牙切端水平内收7.49 mm,上切牙牙轴平均减少12.46°,上颌第一磨牙平均前移0.32 mm.上颌切牙治疗前后差异有统计学意义(P<0.05),上颌磨牙近中位移治疗前后差异无统计学意义.全部病例均获得理想的侧貌改变,前牙覆(牙合)覆盖正常,建立上下磨牙的中性关系和良好的尖窝锁结关系.结论:微型种植体作为强支抗解决上牙弓前凸效果显著.%Objective: To study the effectiveness of micro - implant as a strong anchorage for dental arch protrusion. Methods: 12 patients of severe protrusion of the upper arch, were extracted the bilateral maxillary first premo-lar. Implant placed between the maxillary first molar and second premolar. X-ray skull lateral film was used to observe changes in the position of incisors and molars. Results: Arch protrusion were significantly changed after treatment. The cut ends of the maxillary incisors backed 7. 49 mm, the shaft reduced average 12. 46 °, the average forward of maxillary first molars was 0. 32 mm. Maxillary incisors before and after treatment was statistically significant (P<0. 05). The displacement of maxillary molar was not significant different before and after treatment. All patients got a good profile changes, a neutral relationship between the upper and lower molar and a good sharp junction between the lock nest. Conclusion: Micro-implant as a strong anchorage significant change the dental arch protrusion.

  12. Finding Well-Balanced Pairs of Edge-Disjoint Trees in Edge-Weighted Graphs

    DEFF Research Database (Denmark)

    Bang-Jensen, Jørgen; Goncalves, Daniel; Gørtz, Inge Li

    2007-01-01

    the elements in Y (or equivalently, minimize the maximum of the two sums). In this paper we study the following generalization of the partition problem: given an edge-weighted graph G containing two edge-disjoint spanning trees. Find a pair of edge-disjoint spanning trees such that the maximum weight...... of these two trees is as small as possible. In the case when G is precisely the union of two trees this problem may be seen as a generalization of the partition problem in which we have added a graph structure to the numbers (through the edges) and the extra restriction that only the sets X and Y...... value of an optimal solution. We also show that the approach above may sometimes exclude all the optimal solutions. Both the partition problem and its generalization to the problem above on edge-disjoint spanning trees are special cases of the problem of finding, in a weighted matroid with two disjoint...

  13. The Role of T Helper (TH)17 Cells as a Double-Edged Sword in the Interplay of Infection and Autoimmunity with a Focus on Xenobiotic-Induced Immunomodulation

    OpenAIRE

    Hemdan, Nasr Y.A.; Abu El-Saad, Ahmed M.; Ulrich Sack

    2013-01-01

    Extensive research in recent years suggests that exposure to xenobiotic stimuli plays a critical role in autoimmunity induction and severity and that the resulting response would be exacerbated in individuals with an infection-aroused immune system. In this context, heavy metals constitute a prominent category of xenobiotic substances, known to alter divergent immune cell responses in accidentally and occupationally exposed individuals, thereby increasing the susceptibility to autoimmunity an...

  14. AliEn - EDG Interoperability in ALICE

    OpenAIRE

    Bagnasco, S.; Barbera, R.(Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN, Catania, Italy); Buncic, P.; Carminati, F.; Cerello, P.(Sezione INFN, Turin, Italy); Saiz, P.

    2003-01-01

    AliEn (ALICE Environment) is a GRID-like system for large scale job submission and distributed data management developed and used in the context of ALICE, the CERN LHC heavy-ion experiment. With the aim of exploiting upcoming Grid resources to run AliEn-managed jobs and store the produced data, the problem of AliEn-EDG interoperability was addressed and an in-terface was designed. One or more EDG (European Data Grid) User Interface machines run the AliEn software suite (Cluster Monitor, Stora...

  15. Refining Nodes and Edges of State Machines

    DEFF Research Database (Denmark)

    Hallerstede, Stefan; Snook, Colin

    2011-01-01

    State machines are hierarchical automata that are widely used to structure complex behavioural specifications. We develop two notions of refinement of state machines, node refinement and edge refinement. We compare the two notions by means of examples and argue that, by adopting simple conventions......, they can be combined into one method of refinement. In the combined method, node refinement can be used to develop architectural aspects of a model and edge refinement to develop algorithmic aspects. The two notions of refinement are grounded in previous work. Event-B is used as the foundation for our...

  16. Active-edge planar radiation sensors

    OpenAIRE

    Kenney, C. J.; Segal, J.D.; Westbrook, E.; Parker, Sherwood; Hasi, J.; Da Via, C.; Watts, S.; Morse, J

    2006-01-01

    Many systems in medicine, biology, high-energy physics, and astrophysics require large area radiation sensors. In most of these applications, minimizing the amount of dead area or dead material is crucial. We have developed a new type of silicon radiation sensor in which the device is active to within a few microns of the mechanical edge. Their perimeter is made by a plasma etcher rather than a diamond saw. Their edges can be defined and also passivated by growing, in an intermediate step, a ...

  17. Edge detection techniques for iris recognition system

    International Nuclear Information System (INIS)

    Nowadays security and authentication are the major parts of our daily life. Iris is one of the most reliable organ or part of human body which can be used for identification and authentication purpose. To develop an iris authentication algorithm for personal identification, this paper examines two edge detection techniques for iris recognition system. Between the Sobel and the Canny edge detection techniques, the experimental result shows that the Canny's technique has better ability to detect points in a digital image where image gray level changes even at slow rate

  18. Edge detection techniques for iris recognition system

    Science.gov (United States)

    Tania, U. T.; Motakabber, S. M. A.; Ibrahimy, M. I.

    2013-12-01

    Nowadays security and authentication are the major parts of our daily life. Iris is one of the most reliable organ or part of human body which can be used for identification and authentication purpose. To develop an iris authentication algorithm for personal identification, this paper examines two edge detection techniques for iris recognition system. Between the Sobel and the Canny edge detection techniques, the experimental result shows that the Canny's technique has better ability to detect points in a digital image where image gray level changes even at slow rate.

  19. Particle Size Estimation Based on Edge Density

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-xing

    2005-01-01

    Given image sequences of closely packed particles, the underlying aim is to estimate diameters without explicit segmentation. In a way, this is similar to the task of counting objects without directly counting them. Such calculations may, for example, be useful fast estimation of particle size in different application areas. The topic is that of estimating average size (=average diameter) of packed particles, from formulas involving edge density, and the edges from moment-based thresholding are used. An average shape factor is involved in the calculations, obtained for some frames from crude partial segmentation. Measurement results from about 80 frames have been analyzed.

  20. Active-edge planar radiation sensors

    International Nuclear Information System (INIS)

    Many systems in medicine, biology, high-energy physics, and astrophysics require large area radiation sensors. In most of these applications, minimizing the amount of dead area or dead material is crucial. We have developed a new type of silicon radiation sensor in which the device is active to within a few microns of the mechanical edge. Their perimeter is made by a plasma etcher rather than a diamond saw. Their edges can be defined and also passivated by growing, in an intermediate step, a field oxide on the side surfaces. In this paper, the basic architecture and results from a synchrotron beam test are presented

  1. Group edge choosability of planar graphs without adjacent short cycles

    OpenAIRE

    Xin ZHANG; Liu, Guizhen

    2011-01-01

    In this paper, we aim to introduce the group version of edge coloring and list edge coloring, and prove that all 2-degenerate graphs along with some planar graphs without adjacent short cycles is group $(\\Delta(G)+1)$-edge-choosable while some planar graphs with large girth and maximum degree is group $\\Delta(G)$-edge-choosable.

  2. Optimization of K-edge imaging with spectral CT

    OpenAIRE

    He, Peng; Wei, Biao; Cong, Wenxiang; Wang, Ge

    2012-01-01

    Purpose: Spectral/multienergy CT has the potential to distinguish different materials by K-edge characteristics. K-edge imaging involves the two energy bins on both sides of a K-edge. The authors propose a K-edge imaging optimization model to determine these two energy bins.

  3. Natural domains for edge-degenerate differential operators

    OpenAIRE

    Seiler, Jörg

    2010-01-01

    We study cone differential operators on the half-axis and edge-degenerate differential operators on a half-space. We construct subspaces of edge Sobolev spaces that can be considered as natural domains for edge-degenerate operators and indicate how they can be used in the study of boundary problems for edge-degenerate operators.

  4. Tilings of the Sphere by Edge Congruent Pentagons

    OpenAIRE

    Cheuk, Ka Yue; Cheung, Ho Man; Yan, Min

    2013-01-01

    We study edge-to-edge tilings of the sphere by edge congruent pentagons, under the assumption that there are tiles with all vertices having degree 3. We develop the technique of neighborhood tilings and apply the technique to completely classify edge congruent earth map tilings.

  5. Physics-based edge evaluation for improved color constancy

    NARCIS (Netherlands)

    A. Gijsenij; T. Gevers; J. van de Weijer

    2009-01-01

    Edge-based color constancy makes use of image derivatives to estimate the illuminant. However, different edge types exist in real-world images such as shadow, geometry, material and highlight edges. These different edge types may have a distinctive influence on the performance of the illuminant esti

  6. A Note on Edge Guards in Art Galleries

    CERN Document Server

    Nandakumar, R

    2011-01-01

    We examine the Art Gallery Problem with Edge Guards. We present a heuristic algorithm to arrange edge guards to guard only the inward side of the walls of any N-vertex simple polygonal gallery using at most roof (N/4) edge guards - a weakened version of Toussaint's conjecture on the number of edge guards that can guard an entire simple polygon

  7. Interplay between phosphoinositide lipids and calcium signals at the leading edge of chemotaxing ameboid cells☆

    OpenAIRE

    Falke, Joseph J.; Ziemba, Brian P

    2014-01-01

    The chemotactic migration of eukaryotic ameboid cells up concentration gradients is among the most advanced forms of cellular behavior. Chemotaxis is controlled by a complex network of signaling proteins bound to specific lipids on the cytoplasmic surface of the plasma membrane at the front of the cell, or the leading edge. The central lipid players in this leading edge signaling pathway include the phosphoinositides PI(4,5)P2 (PIP2) and PI(3,4,5)P3 (PIP3), both of which play multiple roles. ...

  8. Restricted Edge Connectivity of BinaryUndirected Kautz Graphs

    Institute of Scientific and Technical Information of China (English)

    OUJian-ping

    2004-01-01

    A restricted edge cut is an edge cut of a connected graph whose removal resultsin a disconnected graph without isolated vertices. The size of a minimum restricted edge cutof a graph G is called its restricted edge connectivity, and is denoted by λ′(G). Let ξ(G) bethe minimum edge degree of graph G. It is known that λ′(G) ≤ξ(G) if G contains restrictededge cuts. Graph G is called maximal restricted edge connected if the equality holds in thethe preceding inequality. In this paper, undirected Kautz graph UK(2, n) is proved to bemaximal restricted edge connected if n ≥ 2.

  9. Edge Cut Domination, Irredundance, and Independence in Graphs

    OpenAIRE

    Fenstermacher, Todd; Hedetniemi, Stephen; Laskar, Renu

    2016-01-01

    An edge dominating set $F$ of a graph $G=(V,E)$ is an \\textit{edge cut dominating set} if the subgraph $\\langle V,G-F \\rangle$ is disconnected. The \\textit{edge cut domination number} $\\gamma_{ct}(G)$ of $G$ is the minimum cardinality of an edge cut dominating set of $G.$ In this paper we study the edge cut domination number and investigate its relationships with other parameters of graphs. We also introduce the properties edge cut irredundance and edge cut independence.

  10. Outlier Edge Detection Using Random Graph Generation Models and Applications

    CERN Document Server

    Zhang, Honglei; Gabbouj, Moncef

    2016-01-01

    Outliers are samples that are generated by different mechanisms from other normal data samples. Graphs, in particular social network graphs, may contain nodes and edges that are made by scammers, malicious programs or mistakenly by normal users. Detecting outlier nodes and edges is important for data mining and graph analytics. However, previous research in the field has merely focused on detecting outlier nodes. In this article, we study the properties of edges and propose outlier edge detection algorithms using two random graph generation models. We found that the edge-ego-network, which can be defined as the induced graph that contains two end nodes of an edge, their neighboring nodes and the edges that link these nodes, contains critical information to detect outlier edges. We evaluated the proposed algorithms by injecting outlier edges into some real-world graph data. Experiment results show that the proposed algorithms can effectively detect outlier edges. In particular, the algorithm based on the Prefe...

  11. Feature fusion method for edge detection of color images

    Institute of Scientific and Technical Information of China (English)

    Ma Yu; Gu Xiaodong; Wang Yuanyuan

    2009-01-01

    A novel feature fusion method is proposed for the edge detection of color images. Except for the typical features used in edge detection, the color contrast similarity and the orientation consistency are also selected as the features. The four features are combined together as a parameter to detect the edges of color images. Experimental results show that the method can inhibit noisy edges and facilitate the detection for weak edges. It has a better performance than conventional methods in noisy environments.

  12. Emergent Properties of Patch Shapes Affect Edge Permeability to Animals

    OpenAIRE

    Nams, Vilis O.

    2011-01-01

    Animal travel between habitat patches affects populations, communities and ecosystems. There are three levels of organization of edge properties, and each of these can affect animals. At the lowest level are the different habitats on each side of an edge, then there is the edge itself, and finally, at the highest level of organization, is the geometry or structure of the edge. This study used computer simulations to (1) find out whether effects of edge shapes on animal behavior can arise as e...

  13. The edge engineering of topological Bi(111) bilayer

    OpenAIRE

    Li, Xiao; Liu, Hai-Wen; Jiang, Hua; Wang, Fa; Feng, Ji

    2014-01-01

    A topological insulator is a novel quantum state, characterized by symmetry-protected non-trivial edge/surface states. Our first-principle simulations show the significant effects of the chemical decoration on edge states of topological Bi(111) bilayer nanoribbon, which remove the trivial edge state and recover the Dirac linear dispersion of topological edge state. By comparing the edge states with and without chemical decoration, the Bi(111) bilayer nanoribbon offers a simple system for asse...

  14. Tiling Problem: Convex Pentagons for Edge-to-Edge Monohedral Tiling and Convex Polygons for Aperiodic Tiling

    OpenAIRE

    Sugimoto, Teruhisa

    2015-01-01

    We show that convex pentagons that can generate edge-to-edge monohedral tilings of the plane can be classified into exactly eight types. Using these results, it is also proved that no single convex polygon can be an aperiodic prototile without matching conditions other than "edge-to-edge."

  15. Protrusio acetabuli in sickle-cell anemia

    International Nuclear Information System (INIS)

    Of 155 adults with sickle-cell anemia (SS, SC), radiographs of the pelvis or hip demonstrated protrusio acetabuli on at least one side in 14 (3 men and 11 women), as indicated by projection of the acetabular line medial to the ilio-ischial line. All 14 patients had bone changes attributable to sickle-cell anemia, including marrow hyperplasia and osteonecrosis; however, the severity of femoral or acetabular osteonecrosis did not appear directly related to the protrusion. The authors conclude that sickle-cell anemia can predispose to development of protrusio acetabuli

  16. The role of T helper (TH)17 cells as a double-edged sword in the interplay of infection and autoimmunity with a focus on xenobiotic-induced immunomodulation.

    Science.gov (United States)

    Hemdan, Nasr Y A; Abu El-Saad, Ahmed M; Sack, Ulrich

    2013-01-01

    Extensive research in recent years suggests that exposure to xenobiotic stimuli plays a critical role in autoimmunity induction and severity and that the resulting response would be exacerbated in individuals with an infection-aroused immune system. In this context, heavy metals constitute a prominent category of xenobiotic substances, known to alter divergent immune cell responses in accidentally and occupationally exposed individuals, thereby increasing the susceptibility to autoimmunity and cancer, especially when accompanied by inflammation-triggered persistent sensitization. This perception is learned from experimental models of infection and epidemiologic studies and clearly underscores the interplay of exposure to such immunomodulatory elements with pre- or postexposure infectious events. Further, the TH17 cell subset, known to be associated with a growing list of autoimmune manifestations, may be the "superstar" at the interface of xenobiotic exposure and autoimmunity. In this review, the most recently established links to this nomination are short-listed to create a framework to better understand new insights into TH17's contributions to autoimmunity. PMID:24151516

  17. The Role of T Helper (TH17 Cells as a Double-Edged Sword in the Interplay of Infection and Autoimmunity with a Focus on Xenobiotic-Induced Immunomodulation

    Directory of Open Access Journals (Sweden)

    Nasr Y. A. Hemdan

    2013-01-01

    Full Text Available Extensive research in recent years suggests that exposure to xenobiotic stimuli plays a critical role in autoimmunity induction and severity and that the resulting response would be exacerbated in individuals with an infection-aroused immune system. In this context, heavy metals constitute a prominent category of xenobiotic substances, known to alter divergent immune cell responses in accidentally and occupationally exposed individuals, thereby increasing the susceptibility to autoimmunity and cancer, especially when accompanied by inflammation-triggered persistent sensitization. This perception is learned from experimental models of infection and epidemiologic studies and clearly underscores the interplay of exposure to such immunomodulatory elements with pre- or postexposure infectious events. Further, the TH17 cell subset, known to be associated with a growing list of autoimmune manifestations, may be the “superstar” at the interface of xenobiotic exposure and autoimmunity. In this review, the most recently established links to this nomination are short-listed to create a framework to better understand new insights into TH17’s contributions to autoimmunity.

  18. Edge maps: Representing flow with bounded error

    KAUST Repository

    Bhatia, Harsh

    2011-03-01

    Robust analysis of vector fields has been established as an important tool for deriving insights from the complex systems these fields model. Many analysis techniques rely on computing streamlines, a task often hampered by numerical instabilities. Approaches that ignore the resulting errors can lead to inconsistencies that may produce unreliable visualizations and ultimately prevent in-depth analysis. We propose a new representation for vector fields on surfaces that replaces numerical integration through triangles with linear maps defined on its boundary. This representation, called edge maps, is equivalent to computing all possible streamlines at a user defined error threshold. In spite of this error, all the streamlines computed using edge maps will be pairwise disjoint. Furthermore, our representation stores the error explicitly, and thus can be used to produce more informative visualizations. Given a piecewise-linear interpolated vector field, a recent result [15] shows that there are only 23 possible map classes for a triangle, permitting a concise description of flow behaviors. This work describes the details of computing edge maps, provides techniques to quantify and refine edge map error, and gives qualitative and visual comparisons to more traditional techniques. © 2011 IEEE.

  19. Superconducting Metallic Glass Transition-Edge-Sensors

    Science.gov (United States)

    Hays, Charles C. (Inventor)

    2013-01-01

    A superconducting metallic glass transition-edge sensor (MGTES) and a method for fabricating the MGTES are provided. A single-layer superconducting amorphous metal alloy is deposited on a substrate. The single-layer superconducting amorphous metal alloy is an absorber for the MGTES and is electrically connected to a circuit configured for readout and biasing to sense electromagnetic radiation.

  20. Nonlocal edge state transport in topological insulators

    Science.gov (United States)

    Protogenov, Alexander P.; Verbus, Valery A.; Chulkov, Evgueni V.

    2013-11-01

    We use the N-terminal scheme for studying the edge-state transport in two-dimensional topological insulators. We find the universal nonlocal response in the ballistic transport approach. This macroscopic exhibition of the topological order offers different areas for applications.

  1. On the edge between tradition and innovation

    DEFF Research Database (Denmark)

    Marchetti, Emanuela; Nandhakumar, Joe

    2011-01-01

    investigate also how external pressure from a network, apparently supporting innovation, may instead create a conflicting system of values, compromising the emergence of a negotiation space and hindering the innovation process. Our study suggests that museum innovation is still unsettled, on the edge between...

  2. Reading Edge. What Works Clearinghouse Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2012

    2012-01-01

    "Reading Edge" is a middle school literacy program that emphasizes cooperative learning, goal setting, feedback, classroom management techniques, and the use of metacognitive strategy, whereby students assess their own skills and learn to apply new ones. The program is a component of the "Success for All"[superscript 2] ("SFA")[R] whole-school…

  3. Universality in edge-source diffusion dynamics

    DEFF Research Database (Denmark)

    Mortensen, Asger; Okkels, Fridolin; Bruus, Henrik

    2006-01-01

    We show that in edge-source diffusion dynamics the integrated concentration N(t) has a universal dependence with a characteristic time scale tau=(A/P)(2)pi/(4D), where D is the diffusion constant while A and P are the cross-sectional area and perimeter of the domain, respectively. For the short...

  4. Students at the Edge of Space

    Science.gov (United States)

    Kennon, Tillman; Roberts, Ed; Fuller, Teresa

    2008-01-01

    Space travel, even low Earth orbit, is probably several years away for most of us; however, students and teachers can research the edge of space by participating in the BalloonSat program. BalloonSat is an offshoot of the Space Grant Consortium's very successful RocketSat program. The Arkansas BalloonSat program consists of teacher-initiated…

  5. Social Justice as a Pedagogy of Edge

    Science.gov (United States)

    Sonu, Debbie J.

    2010-01-01

    In this article, the author discusses social justice as a "pedagogy of edge." She argues that educators hold the privilege to begin reframing the dialogue on social justice as a relation of all subjects and to dredge from within the meanings drawn and practices made in honor of justice. This may require a shift away from social justice as a…

  6. Time-resonant tokamak plasma edge instabilities?

    NARCIS (Netherlands)

    Webster, A. J.; Dendy, R. O.; Calderon, F. A.; Chapman, S. C.; Delabie, E.; Dodt, D.; Felton, R.; Todd, T. N.; Maviglia, F.; Morris, J.; Riccardo, V.; Alper, B.; Brezinsek, S.; Coad, P.; Likonen, J.; Rubel, M.; JET-EFDA Contributors,

    2014-01-01

    For a two week period during the Joint European Torus 2012 experimental campaign, the same high confinement plasma was repeated 151 times. The dataset was analysed to produce a probability density function (pdf) for the waiting times between edge-localized plasma instabilities (ELMs). The result was

  7. Anomalous transport in the tokamak edge

    International Nuclear Information System (INIS)

    The tokamak edge has been studied with arrays of Langmuir and magnetic probes on the DITE and COMPASS-C devices. Measurements of plasma parameters such as density, temperature and radial magnetic field were taken in order to elucidate the character, effect on transport and origin of edge fluctuations. The tokamak edge is a strongly-turbulent environment, with large electrostatic fluctuation levels and broad spectra. The observations, including direct correlation measurements, are consistent with a picture in which the observed magnetic field fluctuations are driven by the perturbations in electrostatic parameters. The propagation characteristics of the turbulence, investigated using digital spectral techniques, appear to be dominated by the variation of the radial electric field, both in limiter and divertor plasmas. A shear layer is formed, associated in each case with the last closed flux surface. In the shear layer, the electrostatic wavenumber spectra are significantly broader. The predictions of a drift wave model (DDGDT) and of a family of models evolving from the rippling mode (RGDT group), are compared with experimental results. RGDT, augmented by impurity radiation effects, is shown to be the most reasonable candidate to explain the nature of the edge turbulence, only failing in its estimate of the wavenumber range. (Author)

  8. Edge Plasma Fluctuations Measurements In Fusion Experiments

    Czech Academy of Sciences Publication Activity Database

    Schrittwieser, R.; Ionita, C.; Balan, P.; Varandas, C. A. F.; Figueiredo, H. F. C.; Silva, C.; Stöckel, Jan; Adámek, Jiří; Hron, Martin; Tichý, M.; Hidalgo, C.; Pedrosa, M. A.; Calderon, E.; Martines, E.; Van Oost, G.; Rasmussen, J.J.; Naulin, V.

    Bled : -, 2005, -. [Nuclear Energy for New Europe 2005. Bled (SI), 05.09.2005-08.09.2005] Institutional research plan: CEZ:AV0Z20430508 Keywords : tokamak * edge plasma * plasma potential * fluctuations * turbulence Subject RIV: BL - Plasma and Gas Discharge Physics

  9. A note on electromagnetic edge modes

    CERN Document Server

    Zuo, Fen

    2016-01-01

    We give an intuitive identification for the electromagnetic edge modes as virtual spinon and vison excitations in quantum spin liquids. As an example, we show how such an identification may reconcile the discrepancy on the logarithmic coefficient of the entanglement entropy on a sphere.

  10. Zone edge effects with variable rate irrigation

    Science.gov (United States)

    Variable rate irrigation (VRI) systems may offer solutions to enhance water use efficiency by addressing variability within a field. However, the design of VRI systems should be considered to maximize application uniformity within sprinkler zones, while minimizing edge effects between such zones alo...

  11. Impurity transport in plasma edge turbulence

    OpenAIRE

    Naulin, Volker; Priego Wood, Martin; Juul Rasmussen, Jens

    2004-01-01

    The turbulent transport of minority species/impurities is investigated in 2D drift-wave turbulence as well as in 3D toroidal drift-Alfven edge turbulence. The full effects of perpendicular and -- in 3D -- parallel advection are kept for the impurity species. Anomalous pinch effects are recovered and explained in terms of Turbulent EquiPartition (TEP)

  12. Edge control in CNC polishing, paper 2: simulation and validation of tool influence functions on edges.

    Science.gov (United States)

    Li, Hongyu; Walker, David; Yu, Guoyu; Sayle, Andrew; Messelink, Wilhelmus; Evans, Rob; Beaucamp, Anthony

    2013-01-14

    Edge mis-figure is regarded as one of the most difficult technical issues for manufacturing the segments of extremely large telescopes, which can dominate key aspects of performance. A novel edge-control technique has been developed, based on 'Precessions' polishing technique and for which accurate and stable edge tool influence functions (TIFs) are crucial. In the first paper in this series [D. Walker Opt. Express 20, 19787-19798 (2012)], multiple parameters were experimentally optimized using an extended set of experiments. The first purpose of this new work is to 'short circuit' this procedure through modeling. This also gives the prospect of optimizing local (as distinct from global) polishing for edge mis-figure, now under separate development. This paper presents a model that can predict edge TIFs based on surface-speed profiles and pressure distributions over the polishing spot at the edge of the part, the latter calculated by finite element analysis and verified by direct force measurement. This paper also presents a hybrid-measurement method for edge TIFs to verify the simulation results. Experimental and simulation results show good agreement. PMID:23388930

  13. Tangential 2-D Edge Imaging for GPI and Edge/Impurity Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Ricardo Maqueda; Dr. Fred M. Levinton

    2011-12-23

    Nova Photonics, Inc. has a collaborative effort at the National Spherical Torus Experiment (NSTX). This collaboration, based on fast imaging of visible phenomena, has provided key insights on edge turbulence, intermittency, and edge phenomena such as edge localized modes (ELMs) and multi-faceted axisymmetric radiation from the edge (MARFE). Studies have been performed in all these areas. The edge turbulence/intermittency studies make use of the Gas Puff Imaging diagnostic developed by the Principal Investigator (Ricardo Maqueda) together with colleagues from PPPL. This effort is part of the International Tokamak Physics Activity (ITPA) edge, scrape-off layer and divertor group joint activity (DSOL-15: Inter-machine comparison of blob characteristics). The edge turbulence/blob study has been extended from the current location near the midplane of the device to the lower divertor region of NSTX. The goal of this effort was to study turbulence born blobs in the vicinity of the X-point region and their circuit closure on divertor sheaths or high density regions in the divertor. In the area of ELMs and MARFEs we have studied and characterized the mode structure and evolution of the ELM types observed in NSTX, as well as the study of the observed interaction between MARFEs and ELMs. This interaction could have substantial implications for future devices where radiative divertor regions are required to maintain detachment from the divertor plasma facing components.

  14. Má oclusão de Classe I com biprotrusão e ausência dos primeiros molares inferiores Angle Class I malocclusion with bimaxillary dental protrusion and missing mandibular first molars

    Directory of Open Access Journals (Sweden)

    Aldino Puppin Filho

    2011-12-01

    Full Text Available O presente relato de caso descreve o tratamento ortodôntico de uma paciente de 24 anos de idade, portadora de má oclusão de Classe I de Angle, com protrusão dos incisivos superiores e inferiores, além de perda recente dos primeiros molares inferiores. O tratamento idealizado envolveu a exodontia dos primeiros pré-molares superiores, aliada ao fechamento dos espaços presentes na arcada inferior. O resultado obtido demonstra a necessidade de planos de tratamento individualizados e a importância dos conceitos biomecânicos para movimentar adequadamente os dentes. Esse caso clínico foi apresentado à Diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO, representando a categoria livre escolha, como parte dos requisitos para obtenção do título de Diplomado pelo BBO.This case report describes the orthodontic treatment of a 24-year-old patient presenting with Angle Class I malocclusion, bimaxillary dental protrusion and recent loss of mandibular molars. Treatment involved extraction of the maxillary first premolars and closing of mandibular first molar spaces. Treatment outcomes demonstrate the need for individualized treatment planning and highlight the key role played by biomechanical concepts in achieving proper orthodontic tooth movement. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO as representative of the free choice category in partial fulfillment of the requirements for obtaining the BBO Diploma.

  15. Morphological types of epithelial-mesenchymal cell contacts in odontogenesis.

    OpenAIRE

    Burgess, A M; Katchburian, E

    1982-01-01

    During early stages of odontogenesis, differentiating ameloblasts form cytoplasmic processes which penetrate deeply into developing uncalcified dentine. Some of these cytoplasmic protrusions form close approximations or contacts with odontoblast processes. The contacts are of a variety of morphological types, but their membranes never fuse or form any known type of cell junction. The present results, together with those derived from other studies, suggest that the approximations or contacts m...

  16. Interplay between edge magnetic topology, pressure profile and blobs in the edge of RFX-mod

    International Nuclear Information System (INIS)

    The observation of the periodic pressure profile time oscillations in the edge region (0.93 p suggests a sort of regulation of the turbulent spatial scale, where Lp sets the radial dimension of the blobs. Moreover, the spatial scale regulation is confirmed by observing a linear scaling between the energy injection scale and the toroidal dimension of the edge coherent structures. On the other hand, the link between ∇Pe and turbulence level does not hold locally: the edge fluctuation level is higher in the toroidal region of lower edge pressure gradient. Hence if coherent structures are generated locally in the region of strongest ∇Pe, they flow and accumulate where ∇Pe is lower. (paper)

  17. EDGE2D modelling of edge profiles obtained in JET diagnostic optimized configuration

    Energy Technology Data Exchange (ETDEWEB)

    Kallenbach, A [MPI fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Andrew, Y [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Beurskens, M [FOM-Rijnhuizen, Ass. Euratom-FOM, TEC (Netherlands); Corrigan, G [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Eich, T [MPI fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Jachmich, S [ERM, Brussels (Belgium); Kempenaars, M [FOM-Rijnhuizen, Ass. Euratom-FOM, TEC (Netherlands); Korotkov, A [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Loarte, A [EFDA Close Support Unit, Garching (Germany); Matthews, G [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Monier-Garbet, P [CEA Cadarache (France); Saibene, G [EFDA Close Support Unit, Garching (Germany); Spence, J [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Suttrop, W [MPI fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)

    2004-03-01

    Nine type-I ELMy H-mode discharges in diagnostic optimized configuration in JET are analysed with the EDGE2D/NIMBUS package. EDGE2D solves the fluid equations for the conservation of particles, momentum and energy for hydrogenic and impurity ions, while neutrals are followed with the two-dimensional Monte Carlo module NIMBUS. Using external boundary conditions from the experiment, the perpendicular heat conductivities {chi}{sub i,e} and the particle transport coefficients D, v are varied until good agreement between code result and measured data is obtained. A step-like ansatz is used for the edge transport parameters for the outer core region, the edge transport barrier and the outer scrape-off layer. The time-dependent effect of edge localized modes on the edge profiles is simulated with an ad hoc ELM model based on the repetitive increase of the transport coefficients {chi}{sub i,e} and D. The values of the transport coefficients are matched to experimental data mapped to the outer midplane, in the course of which radial shifts of experimental profiles of the order of 1 cm caused by the accuracy limit of the equilibrium reconstruction are taken into account. Simulated divertor profiles obtained from the upstream transport ansatz and the experimental boundary conditions agree with measurements, except a small region localized at the separatrix strike points which is supposed to be affected by direct ion losses. The integrated analysis using EDGE2D modelling, although still limited by the marginal spatial resolution of individual diagnostics, allows the characterization of profiles in the edge/pedestal region and supplies additional information on the separatrix position. The steep density gradient zone inside the separatrix shrinks compared to the electron temperature with increasing density, indicating the effect of the neutral penetration depth becoming shorter than the region of reduced transport.

  18. Urbanization Impacts on Mammals across Urban-Forest Edges and a Predictive Model of Edge Effects

    OpenAIRE

    Nélida R Villaseñor; Driscoll, Don A.; Martín A H Escobar; Philip Gibbons; Lindenmayer, David B

    2014-01-01

    With accelerating rates of urbanization worldwide, a better understanding of ecological processes at the wildland-urban interface is critical to conserve biodiversity. We explored the effects of high and low-density housing developments on forest-dwelling mammals. Based on habitat characteristics, we expected a gradual decline in species abundance across forest-urban edges and an increased decline rate in higher contrast edges. We surveyed arboreal mammals in sites of high and low housing den...

  19. 后路脊椎镜治疗腰椎间盘突出症与术后早期功能锻炼的相关性%Correlation of early functional exercises after the operation with vertebrascope in route of retreat to treat lumbar disc protrusion

    Institute of Scientific and Technical Information of China (English)

    吕原; 姚建祥; 张宁; 张庆彬; 赵立新; 朱卉敏; 于振声

    2002-01-01

    Objective To observe therapeutic effect in the near future of the operation of vertebrascope in route of retreat to treat lumbar disc protrusion and complications.Method According to symptoms,signs,myelography and CTM results to determine protrusion interspace and side type,applied the operation of vertebrascope in route of retreat to treat lumbar disc protrusion and perform functional exercises.Results 86 patients were followed up,and within these patients,58 appeared excellent (67% ),25 appeared good (29% ), 2 appeared not bad (2% ),and 1 appeared bad(1% ).Conclusion The technology has many advantages, such as little wound, little hemorrhage, little pain and fast restoration,which provide advantageous conditions for early functional exercises after operation.

  20. Approximating the Edge Length of 2-Edge Connected Planar Geometric Graphs on a Set of Points

    CERN Document Server

    Dobrev, Stefan; Krizanc, Danny; Morales-Ponce, Oscar; Stacho, Ladislav

    2011-01-01

    Given a set $P$ of $n$ points in the plane, we solve the problems of constructing a geometric planar graph spanning $P$ 1) of minimum degree 2, and 2) which is 2-edge connected, respectively, and has max edge length bounded by a factor of 2 times the optimal; we also show that the factor 2 is best possible given appropriate connectivity conditions on the set $P$, respectively. First, we construct in $O(n\\log{n})$ time a geometric planar graph of minimum degree 2 and max edge length bounded by 2 times the optimal. This is then used to construct in $O(n\\log n)$ time a 2-edge connected geometric planar graph spanning $P$ with max edge length bounded by $\\sqrt{5}$ times the optimal, assuming that the set $P$ forms a connected Unit Disk Graph. Second, we prove that 2 times the optimal is always sufficient if the set of points forms a 2 edge connected Unit Disk Graph and give an algorithm that runs in $O(n^2)$ time. We also show that for $k \\in O(\\sqrt{n})$, there exists a set $P$ of $n$ points in the plane such th...

  1. Edge-to-edge matching - a new approach to the morphology and crystallography of precipitates

    International Nuclear Information System (INIS)

    An entirely new approach is taken to understanding the morphology and crystallography of partially coherent precipitates formed by diffusional processes 'edge-to-edge matching'. This approach is based on the simple, well founded result put forward by Shiflet and Van der Merwe [Metallurgical and Materials Transactions A. 25A (1994) 1895] - namely that minimisation of interfacial energy results when rows of atoms match across the interface. The geometric conditions necessary to achieve this atom row matching are shown to be possible for a variety of lattice parameters in the fcc/bcc system provided there is edge-to-edge matching of planes containing these rows in each of the two phases. This new model does not rely on physical assumptions of dubious validity, such as the existence of a long-range correspondence. It also differs from the existing models in that it does not need to include the particular orientation relationship as part of the input data. Instead it is capable of predicting the orientation relationship from first principles. The development of the concepts behind edge-to-edge matching are described for the fcc/bcc system, predictions of orientation relationships and habit planes are made for a variety of different precipitates and shown to be in extremely good agreement with reported experimental results

  2. Independent component analysis of edge information for face recognition

    CERN Document Server

    Karande, Kailash Jagannath

    2013-01-01

    The book presents research work on face recognition using edge information as features for face recognition with ICA algorithms. The independent components are extracted from edge information. These independent components are used with classifiers to match the facial images for recognition purpose. In their study, authors have explored Canny and LOG edge detectors as standard edge detection methods. Oriented Laplacian of Gaussian (OLOG) method is explored to extract the edge information with different orientations of Laplacian pyramid. Multiscale wavelet model for edge detection is also propos

  3. Edge Detection in Satellite Image Using Cellular Neural Network

    Directory of Open Access Journals (Sweden)

    Osama Basil Gazi

    2014-10-01

    Full Text Available The present paper proposes a novel approach for edge detection in satellite images based on cellular neural networks. CNN based edge detector in used conjunction with image enhancement and noise removal techniques, in order to deliver accurate edge detection results, compared with state of the art approaches. Thus, considering the obtained results, a comparison with optimal Canny edge detector is performed. The proposed image processing chain deliver more details regarding edges than canny edge detector. The proposed method aims to preserve salient information, due to its importance in all satellite image processing applications.

  4. Edge Solitons in Nonlinear Photonic Topological Insulators

    CERN Document Server

    Leykam, Daniel

    2016-01-01

    We show theoretically that a photonic topological insulator can support edge solitons that are strongly self-localized and propagate unidirectionally along the lattice edge. The photonic topological insulator consists of a Floquet lattice of coupled helical waveguides, in a medium with local Kerr nonlinearity. The soliton behavior is strongly affected by the topological phase of the linear lattice. The topologically nontrivial phase gives a continuous family of solitons, while the topologically trivial phase gives an embedded soliton that occurs at a single power, and arises from a self-induced local nonlinear shift in the inter-site coupling. The solitons can be used for nonlinear switching and logical operations, functionalities that have not yet been explored in topological photonics. We demonstrate using solitons to perform selective filtering via propagation through a narrow channel, and using soliton collisions for optical switching.

  5. Edge-disjoint Hamiltonian cycles in hypertournaments

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2006-01-01

    We introduce a method for reducing k-tournament problems, for k >= 3, to ordinary tournaments, that is, 2-tournaments. It is applied to show that a k-tournament on n >= k + 1 + 24d vertices (when k >= 4) or on n >= 30d + 2 vertices (when k = 3) has d edge-disjoint Hamiltonian cycles if and only if...... it is d-edge-connected. Ironically, this is proved by ordinary tournament arguments although it only holds for k >= 3. We also characterizatize the pancyclic k-tournaments, a problem posed by Gutin and Yeo.(Our characterization is slightly incomplete in that we prove it only for n large compared to k...

  6. Electronic quantum teleportation in Hall edge channels

    CERN Document Server

    Buscemi, Fabrizio; Bertoni, Andrea

    2011-01-01

    We present a proposal for the quantum teleportation of electrons in an edge channel setup operating in the quantum Hall regime. Three qubits are used, each defined by the occupancy of a couple of edge channels connected to source and drains leads providing electrical control of initialization and readouts. Our scheme consists of two concatenated two-particle Hanbury Brown-Twiss (HBT) interferometers [Nederet al.}, Nature, 448, 333 (2007)] and, in analogy with quantum optics implementations, can be realized by means of linear quantum gates only, without relying on inter-electron Coulomb interaction. We show how the coincident detection of two carriers in couples of drains allows teleportation with a 50% success rate.

  7. Nonlinear dynamics in the Tokamak edge

    International Nuclear Information System (INIS)

    The nonlinear character of the Tokamak edge results from a unique combination of parameters, leading to a wide dynamical range for most processes. The energetically consistent gyrokinetic equilibrium is emphasised. Edge turbulence computed gyrokinetically exhibits energetic contact to mesoscale MHD and does not follow linear scaling. Gyrofluid studies show self consistent profiles, currents and flows which are kicked out of equilibrium to varying degree. L-mode turbulence and ELM crash phenomenology are both examples of energetic contact between turbulence and MHD, with opposite causality. The overall equilibrium is a statistical saturation rather than a state to which the plasma dissipatively converges (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. GSGG edge cladding development: Final technical report

    International Nuclear Information System (INIS)

    The objectives of this project have been: (1) Investigate the possibility of chemical etching of GSGG crystal slabs to obtain increased strength. (2) Design and construct a simplified mold assembly for casting cladding glass to the edges of crystal slabs of different dimensions. (3) Conduct casting experiments to evaluate the redesigned mold assembly and to determine stresses as function of thermal expansion coefficient of cladding glass. (4) Clad larger sizes of GGG slabs as they become available. These tasks have been achieved. Chemical etching of GSGG slabs does not appear possible with any other acid than H3PO4 at temperatures above 3000C. A mold assembly has been constructed which allowed casting cladding glass around the edges of the largest GGG slabs available (10 x 20 x 160 mm) without causing breakage through the annealing step

  9. Iris Localization Based on Edge Searching Strategies

    Institute of Scientific and Technical Information of China (English)

    Wang Yong; Han Jiuqiang

    2005-01-01

    An iris localization scheme based on edge searching strategies is presented. First, the edge detection operator Laplacian-ofGaussian (LoG) is used to iris original image to search its inner boundary. Then, a circle detection operator is introduced to locate the outer boundary and its center, which is invariant of translation, rotation and scale. Finally, the method of curve fitting is developed in localization of eyelid. The performance of the proposed method is tested with 756 iris images from 108 different classes in CASIA Iris Database and compared with the conventional Hough transform method. The experimental results show that without loss of localization accuracy, the proposed iris localization algorithm is apparently faster than Hough transform.

  10. Absence of many-body mobility edges

    Science.gov (United States)

    De Roeck, Wojciech; Huveneers, Francois; Müller, Markus; Schiulaz, Mauro

    2016-01-01

    Localization transitions as a function of temperature require a many-body mobility edge in energy, separating localized from ergodic states. We argue that this scenario is inconsistent because local fluctuations into the ergodic phase within the supposedly localized phase can serve as mobile bubbles that induce global delocalization. Such fluctuations inevitably appear with a low but finite density anywhere in any typical state. We conclude that the only possibility for many-body localization to occur is lattice models that are localized at all energies. Building on a close analogy with a model of assisted two-particle hopping, where interactions induce delocalization, we argue why hot bubbles are mobile and do not localize upon diluting their energy. Numerical tests of our scenario show that previously reported mobility edges cannot be distinguished from finite-size effects.

  11. Multi-scale Regions from Edge Fragments

    DEFF Research Database (Denmark)

    Kazmi, Wajahat; Andersen, Hans Jørgen

    2014-01-01

    In this article we introduce a novel method for detecting multi-scale salient regions around edges using a graph based image compression algorithm. Images are recursively decomposed into triangles arranged into a binary tree using linear interpolation. The entropy of any local region of the image...... is inherent in the areas of the triangles and tree depth. We introduce twin leaves as nodes whose sibling share the same characteristics. Triangles corresponding to the twin leaves are filtered out from the binary tree. Graph connectivity is exploited to get clusters of triangles followed by ellipse...... fitting to estimate regions. Salient regions are thus formed as stable regions around edges. Tree hierarchy is then used to generate multi-scale regions. We evaluate our detector by performing image retrieval tests on our building database which shows that combined with Spin Images (Lazebnik et al., 2003...

  12. On thermal edge effects in composite laminates

    Science.gov (United States)

    Herakovich, C. T.

    1976-01-01

    Results are presented for a finite-element investigation of the combined influence of edge effects due to mechanical and thermal mismatch in composite laminates with free edges. Laminates of unidirectional boron/epoxy symmetrically bonded to sheets of aluminum and titanium were studied. It is shown that interlaminar thermal stresses may be more significant than the interlaminar stresses due to loading only. In addition, the stresses due to thermal mismatch may be of the same sign as those due to Poisson's mismatch or they may be of opposite sign depending upon material properties, stacking sequence, and direction of loading. The paper concludes with a brief discussion of thermal stresses in all-composite laminates.

  13. Stress and efficiency studies in edge-defined film-fed growth

    Science.gov (United States)

    Kalejs, J.

    1986-01-01

    The progress was reviewed for stress and efficiency studies of edge-defined film-fed growth (EFG) material. Effort was concentrated on the definition of condiitions that will reduce stress, on quantifying dislocation electrical activity and limits on solar cell efficiency, and on studying the effects of dopants on EFG characteristics.

  14. Edge effects on water droplet condensation

    OpenAIRE

    Medici, Marie-Gabrielle; Mongruel, Anne; Royon, Laurent; Beysens, Daniel

    2014-01-01

    International audience In this study is investigated the effect of geometrical or thermal discontinuities on the growth of water droplets condensing on a cooled substrate. Edges, corners, cooled/non cooled boundaries can have a strong effect on the vapor concentration profile and mass diffusion around the drops. In comparison to growth in a pattern where droplets have to compete to catch vapor, which results in a linear water concentration profile directed perpendicularly to the substrate,...

  15. Combining geometric edge detectors for feature detection

    OpenAIRE

    Heyvaert, Michaël; Van Hamme, David; Coppens, Jonas; Veelaert, Peter

    2010-01-01

    We propose a novel framework for the analysis and modeling of discrete edge filters, based on the notion of signed rays. This framework will allow us to easily deduce the geometric and localization properties of a family of first-order filters, and use this information to design custom filter banks for specific applications. As an example, a set of angle-selective corner detectors is constructed for the detection of buildings in video sequences. This clearly illustrates the merit of the theor...

  16. Community Detection Using Multilayer Edge Mixture Model

    OpenAIRE

    Zhang, Han; Wang, Chang-Dong; Lai, Jian-Huang; PHILIP S. YU

    2016-01-01

    A wide range of complex systems can be modeled as networks with corresponding constraints on the edges and nodes, which have been extensively studied in recent years. Nowadays, with the progress of information technology, systems that contain the information collected from multiple perspectives have been generated. The conventional models designed for single perspective networks fail to depict the diverse topological properties of such systems, so multilayer network models aiming at describin...

  17. Edge plasma studies on the CASTOR tokamak

    Czech Academy of Sciences Publication Activity Database

    Hron, Martin; Peleman, P.; Spolaore, M.; Martines, E.; Hronová-Bilyková, Olena; Dejarnac, Renaud; Devynck, P.; Brotánková, Jana; Sentkerestiová, Jana; Ďuran, Ivan; Gunn, J.; Stöckel, Jan; Van Oost, G.; Adámek, Jiří; van de Peppel, L.; Štěpán, Michal

    Krakow : Euratom - IPPLM Association, 2006 - (Zagorski, R.), - [IEA Large Tokamak IA Workshop on Edge Transport in Fusion plasmas. Kraków (PL), 11.09.2006-13.09.2006] Institutional research plan: CEZ:AV0Z20430508 Keywords : tokamak * plasma * scrape-off layer * turbulence * interchange instability Subject RIV: BL - Plasma and Gas Discharge Physics http://www.etfp2006.ifpilm.waw.pl/presentations.html

  18. Edge Localized Mode Control in TCV

    OpenAIRE

    Rossel, Jonathan

    2012-01-01

    The Tokamak concept, based on magnetic confinement of a hydrogen plasma, is one of today's most promising paths to energy production by nuclear fusion. The experimental scenarios leading to the largest fusion rate are based on a high confinement plasma regime, the H-mode, in which the energy and particle confinement are enhanced by a transport barrier located at the plasma edge and forming a pedestal in the plasma pressure profile. In standard axisymm...

  19. Multiscale Edge Detection in the Corona

    OpenAIRE

    Young, C. Alex; Gallagher, Peter T.

    2008-01-01

    Coronal Mass Ejections (CMEs) are challenging objects to detect using automated techniques, due to their high velocity and diffuse, irregular morphology. A necessary step to automating the detection process is to first remove the subjectivity introduced by the observer used in the current, standard, CME detection and tracking method. Here we describe and demonstrate a multiscale edge detection technique that addresses this step and could serve as one part of an automated CME detection system....

  20. Resistive MHD in tokamak edge regions

    International Nuclear Information System (INIS)

    Several results on resistive MHD in tokamak edge regions, relevant to the H-mode transition, are presented: quasilinear drift tearing modes as an H-mode trigger; stabilization of drift tearing modes by sheared poloidal rotation; and the effect of sheared rotation on electrostatic drift resistive ballooning modes. Quasilinear drift tearing modes have a critical Δ'∼Te3/BT2, which might give a threshold similar to the observed scaling. The quasilinear regime is valid for island widths as large as the tearing layer width, which can be about 1-3 cm, for typical edge parameters. Cross field thermal conductivity has an essential role in maintaining quasilinear islands. Stabilization of the modes might trigger the H-mode, if destruction of magnetic surfaces around the separatrix increases edge transport, and shorts out a radial electric field. Because drift effects do not persist in the nonlinear regime, drift stabilization does not work for larger islands. Sheared rotation is an effective stabilization mechanism in both quasilinear and nonlinear regimes of the drift tearing mode. In the quasilinear regime, velocity shear increases the critical Δ'. The required velocity gradient to stabilize a nonlinear island is large, but experimental parameters appear adequate to provide stabilization. Sheared rotation also has a stabilizing effect on electrostatic resistive ballooning modes. Only the drift resistive ballooning mode survives above a critical edge Te. The linear growth rate of these modes is slowed by sheared rotation, when the poloidal velocity gradient exceeds the drift frequency. A resonance can occur when v'θ = ω*, giving a growth rate proportional to η1/2. For shorter wavelengths, the growth rate is not affected by the rotation