Sample records for talin head domain

  1. The Talin Head Domain Reinforces Integrin-Mediated Adhesion by Promoting Adhesion Complex Stability and Clustering

    PubMed Central

    Ellis, Stephanie J.; Lostchuck, Emily; Goult, Benjamin T.; Bouaouina, Mohamed; Fairchild, Michael J.; López-Ceballos, Pablo; Calderwood, David A.; Tanentzapf, Guy

    2014-01-01

    Talin serves an essential function during integrin-mediated adhesion in linking integrins to actin via the intracellular adhesion complex. In addition, the N-terminal head domain of talin regulates the affinity of integrins for their ECM-ligands, a process known as inside-out activation. We previously showed that in Drosophila, mutating the integrin binding site in the talin head domain resulted in weakened adhesion to the ECM. Intriguingly, subsequent studies showed that canonical inside-out activation of integrin might not take place in flies. Consistent with this, a mutation in talin that specifically blocks its ability to activate mammalian integrins does not significantly impinge on talin function during fly development. Here, we describe results suggesting that the talin head domain reinforces and stabilizes the integrin adhesion complex by promoting integrin clustering distinct from its ability to support inside-out activation. Specifically, we show that an allele of talin containing a mutation that disrupts intramolecular interactions within the talin head attenuates the assembly and reinforcement of the integrin adhesion complex. Importantly, we provide evidence that this mutation blocks integrin clustering in vivo. We propose that the talin head domain is essential for regulating integrin avidity in Drosophila and that this is crucial for integrin-mediated adhesion during animal development. PMID:25393120

  2. Structure of a double ubiquitin-like domain in the talin head: a role in integrin activation

    PubMed Central

    Goult, Benjamin T; Bouaouina, Mohamed; Elliott, Paul R; Bate, Neil; Patel, Bipin; Gingras, Alexandre R; Grossmann, J Günter; Roberts, Gordon C K; Calderwood, David A; Critchley, David R; Barsukov, Igor L

    2010-01-01

    Talin is a 270-kDa protein that activates integrins and couples them to cytoskeletal actin. Talin contains an N-terminal FERM domain comprised of F1, F2 and F3 domains, but it is atypical in that F1 contains a large insert and is preceded by an extra domain F0. Although F3 contains the binding site for β-integrin tails, F0 and F1 are also required for activation of β1-integrins. Here, we report the solution structures of F0, F1 and of the F0F1 double domain. Both F0 and F1 have ubiquitin-like folds joined in a novel fixed orientation by an extensive charged interface. The F1 insert forms a loop with helical propensity, and basic residues predicted to reside on one surface of the helix are required for binding to acidic phospholipids and for talin-mediated activation of β1-integrins. This and the fact that basic residues on F2 and F3 are also essential for integrin activation suggest that extensive interactions between the talin FERM domain and acidic membrane phospholipids are required to orientate the FERM domain such that it can activate integrins. PMID:20150896

  3. The effect of intact talin and talin tail fragment on actin filament dynamics and structure depends on pH and ionic strength.

    PubMed

    Goldmann, W H; Hess, D; Isenberg, G

    1999-03-01

    We employed quasi-elastic light scattering and electron microscopy to investigate the influence of intact talin and talin tail fragment on actin filament dynamics and network structure. Using these methods, we confirm previous reports that intact talin induces cross-linking as well as filament shortening on actin networks. We now show that the effect of intact talin as well as talin tail fragment on actin networks is controlled by pH and ionic strength. At pH 7.5, actin filament dynamics in the presence of intact talin and talin tail fragment are characterized by a rapid decay of the dynamic structure factor and by a square root power law for the stretched exponential decay which is in contrast with the theory for pure actin solutions. At pH 6 and low ionic strength, intact talin cross-links actin filaments more tightly than talin tail fragment. Talin head fragment showed no effect on actin networks, indicating that the actin binding sites reside probably exclusively within the tail domain.

  4. The mechanical response of talin

    NASA Astrophysics Data System (ADS)

    Yao, Mingxi; Goult, Benjamin T.; Klapholz, Benjamin; Hu, Xian; Toseland, Christopher P.; Guo, Yingjian; Cong, Peiwen; Sheetz, Michael P.; Yan, Jie

    2016-07-01

    Talin, a force-bearing cytoplasmic adapter essential for integrin-mediated cell adhesion, links the actin cytoskeleton to integrin-based cell-extracellular matrix adhesions at the plasma membrane. Its C-terminal rod domain, which contains 13 helical bundles, plays important roles in mechanosensing during cell adhesion and spreading. However, how the structural stability and transition kinetics of the 13 helical bundles of talin are utilized in the diverse talin-dependent mechanosensing processes remains poorly understood. Here we report the force-dependent unfolding and refolding kinetics of all talin rod domains. Using experimentally determined kinetics parameters, we determined the dynamics of force fluctuation during stretching of talin under physiologically relevant pulling speeds and experimentally measured extension fluctuation trajectories. Our results reveal that force-dependent stochastic unfolding and refolding of talin rod domains make talin a very effective force buffer that sets a physiological force range of only a few pNs in the talin-mediated force transmission pathway.

  5. Identification of a repeated domain within mammalian alpha-synemin that interacts directly with talin.

    PubMed

    Sun, Ning; Critchley, David R; Paulin, Denise; Li, Zhenlin; Robson, Richard M

    2008-05-01

    The type VI intermediate filament (IF) protein synemin is a unique member of the IF protein superfamily. Synemin associates with the major type III IF protein desmin forming heteropolymeric intermediate filaments (IFs) within developed mammalian striated muscle cells. These IFs encircle and link all adjacent myofibrils together at their Z-lines, as well as link the Z-lines of the peripheral layer of cellular myofibrils to the costameres located periodically along and subjacent to the sarcolemma. Costameres are multi-protein assemblies enriched in the cytoskeletal proteins vinculin, alpha-actinin, and talin. We report herein a direct interaction of human alpha-synemin with the cytoskeletal protein talin by protein-protein interaction assays. The 312 amino acid insert (SNTIII) present only within alpha-synemin binds to the rod domain of talin in vitro and co-localizes with talin at focal adhesion sites within mammalian muscle cells. Confocal microscopy studies showed that synemin co-localizes with talin within the costameres of human skeletal muscle cells. Analysis of the primary sequences of human alpha- and beta-synemins revealed that SNTIII is composed of seven tandem repeats, each containing a specific Ser/Thr-X-Arg-His/Gln (S/T-X-R-H/Q) motif. Our results suggest human alpha-synemin plays an essential role in linking the heteropolymeric IFs to adherens-type junctions, such as the costameres within mammalian striated muscle cells, via its interaction with talin, thereby helping provide mechanical integration for the muscle cell cytoskeleton.

  6. Talin-dependent integrin activation is required for fibrin clot retraction by platelets

    PubMed Central

    Haling, Jacob R.; Monkley, Susan J.; Critchley, David R.

    2011-01-01

    Talin functions both as a regulator of integrin affinity and as an important mechanical link between integrins and the cytoskeleton. Using genetic deletion of talin, we show for the first time that the capacity of talin to activate integrins is required for fibrin clot retraction by platelets. To further dissect which talin functions are required for this process, we tested clot retraction in platelets expressing a talin1(L325R) mutant that binds to integrins, but exhibits impaired integrin activation ascribable to disruption of the interaction between talin and the membrane-proximal region (MPR) in the β-integrin cytoplasmic domain. Talin-deficient and talin1(L325R) platelets were defective in retracting fibrin clots. However, the defect in clot retraction in talin1(L325R) platelets, but not talin-deficient platelets, was rescued by extrinsically activating integrins with manganese, thereby proving that integrin activation is required and showing that talin1(L325R) can form functional links to the actin cytoskeleton. PMID:20971947

  7. Intrasteric inhibition mediates the interaction of the I/LWEQ module proteins Talin1, Talin2, Hip1, and Hip12 with actin.

    PubMed

    Senetar, Melissa A; Foster, Stanley J; McCann, Richard O

    2004-12-14

    The I/LWEQ module superfamily is a class of actin-binding proteins that contains a conserved C-terminal actin-binding element known as the I/LWEQ module. I/LWEQ module proteins include the metazoan talins, the cellular slime mold talin homologues TalA and TalB, fungal Sla2p, and the metazoan Sla2 homologues Hip1 and Hip12 (Hip1R). These proteins possess a similar modular organization that includes an I/LWEQ module at their C-termini and either a FERM domain or an ENTH domain at their N-termini. As a result of this modular organization, I/LWEQ module proteins may serve as linkers between cellular compartments, such as the plasma membrane and the endocytic machinery, and the actin cytoskeleton. Previous studies have shown that I/LWEQ module proteins bind to F-actin. In this report, we have determined the affinity of the I/LWEQ module proteins Talin1, Talin2, huntingtin interacting protein-1 (Hip1), and the Hip1-related protein (Hip1R/Hip12) for F-actin and identified a conserved structural element that interferes with the actin binding capacity of these proteins. Our data support the hypothesis that the actin-binding determinants in native talin and other I/LWEQ module proteins are cryptic and indicate that the actin binding capacities of Talin1, Talin2, Hip1, and Hip12 are regulated by intrasteric occlusion of primary actin-binding determinants within the I/LWEQ module. We have also found that the I/LWEQ module contains a dimerization motif and stabilizes actin filaments against depolymerization. This activity may contribute to the function of talin in cell adhesion and the roles of Hip1, Hip12 (Hip1R), and Sla2p in endocytosis.

  8. WAVE2 Regulates High-Affinity Integrin Binding by Recruiting Vinculin and Talin to the Immunological Synapse▿

    PubMed Central

    Nolz, Jeffrey C.; Medeiros, Ricardo B.; Mitchell, Jason S.; Zhu, Peimin; Freedman, Bruce D.; Shimizu, Yoji; Billadeau, Daniel D.

    2007-01-01

    T-cell-receptor (TCR)-mediated integrin activation is required for T-cell-antigen-presenting cell conjugation and adhesion to extracellular matrix components. While it has been demonstrated that the actin cytoskeleton and its regulators play an essential role in this process, no mechanism has been established which directly links TCR-induced actin polymerization to the activation of integrins. Here, we demonstrate that TCR stimulation results in WAVE2-ARP2/3-dependent F-actin nucleation and the formation of a complex containing WAVE2, ARP2/3, vinculin, and talin. The verprolin-connecting-acidic (VCA) domain of WAVE2 mediates the formation of the ARP2/3-vinculin-talin signaling complex and talin recruitment to the immunological synapse (IS). Interestingly, although vinculin is not required for F-actin or integrin accumulation at the IS, it is required for the recruitment of talin. In addition, RNA interference of either WAVE2 or vinculin inhibits activation-dependent induction of high-affinity integrin binding to VCAM-1. Overall, these findings demonstrate a mechanism in which signals from the TCR produce WAVE2-ARP2/3-mediated de novo actin polymerization, leading to integrin clustering and high-affinity binding through the recruitment of vinculin and talin. PMID:17591693

  9. WAVE2 regulates high-affinity integrin binding by recruiting vinculin and talin to the immunological synapse.

    PubMed

    Nolz, Jeffrey C; Medeiros, Ricardo B; Mitchell, Jason S; Zhu, Peimin; Freedman, Bruce D; Shimizu, Yoji; Billadeau, Daniel D

    2007-09-01

    T-cell-receptor (TCR)-mediated integrin activation is required for T-cell-antigen-presenting cell conjugation and adhesion to extracellular matrix components. While it has been demonstrated that the actin cytoskeleton and its regulators play an essential role in this process, no mechanism has been established which directly links TCR-induced actin polymerization to the activation of integrins. Here, we demonstrate that TCR stimulation results in WAVE2-ARP2/3-dependent F-actin nucleation and the formation of a complex containing WAVE2, ARP2/3, vinculin, and talin. The verprolin-connecting-acidic (VCA) domain of WAVE2 mediates the formation of the ARP2/3-vinculin-talin signaling complex and talin recruitment to the immunological synapse (IS). Interestingly, although vinculin is not required for F-actin or integrin accumulation at the IS, it is required for the recruitment of talin. In addition, RNA interference of either WAVE2 or vinculin inhibits activation-dependent induction of high-affinity integrin binding to VCAM-1. Overall, these findings demonstrate a mechanism in which signals from the TCR produce WAVE2-ARP2/3-mediated de novo actin polymerization, leading to integrin clustering and high-affinity binding through the recruitment of vinculin and talin.

  10. Talin determines the nanoscale architecture of focal adhesions.

    PubMed

    Liu, Jaron; Wang, Yilin; Goh, Wah Ing; Goh, Honzhen; Baird, Michelle A; Ruehland, Svenja; Teo, Shijia; Bate, Neil; Critchley, David R; Davidson, Michael W; Kanchanawong, Pakorn

    2015-09-01

    Insight into how molecular machines perform their biological functions depends on knowledge of the spatial organization of the components, their connectivity, geometry, and organizational hierarchy. However, these parameters are difficult to determine in multicomponent assemblies such as integrin-based focal adhesions (FAs). We have previously applied 3D superresolution fluorescence microscopy to probe the spatial organization of major FA components, observing a nanoscale stratification of proteins between integrins and the actin cytoskeleton. Here we combine superresolution imaging techniques with a protein engineering approach to investigate how such nanoscale architecture arises. We demonstrate that talin plays a key structural role in regulating the nanoscale architecture of FAs, akin to a molecular ruler. Talin diagonally spans the FA core, with its N terminus at the membrane and C terminus demarcating the FA/stress fiber interface. In contrast, vinculin is found to be dispensable for specification of FA nanoscale architecture. Recombinant analogs of talin with modified lengths recapitulated its polarized orientation but altered the FA/stress fiber interface in a linear manner, consistent with its modular structure, and implicating the integrin-talin-actin complex as the primary mechanical linkage in FAs. Talin was found to be ∼97 nm in length and oriented at ∼15° relative to the plasma membrane. Our results identify talin as the primary determinant of FA nanoscale organization and suggest how multiple cellular forces may be integrated at adhesion sites.

  11. Podocyte-associated talin1 is critical for glomerular filtration barrier maintenance

    PubMed Central

    Tian, Xuefei; Kim, Jin Ju; Monkley, Susan M.; Gotoh, Nanami; Nandez, Ramiro; Soda, Keita; Inoue, Kazunori; Balkin, Daniel M.; Hassan, Hossam; Son, Sung Hyun; Lee, Yashang; Moeckel, Gilbert; Calderwood, David A.; Holzman, Lawrence B.; Critchley, David R.; Zent, Roy; Reiser, Jochen; Ishibe, Shuta

    2014-01-01

    Podocytes are specialized actin-rich epithelial cells that line the kidney glomerular filtration barrier. The interface between the podocyte and the glomerular basement membrane requires integrins, and defects in either α3 or β1 integrin, or the α3β1 ligand laminin result in nephrotic syndrome in murine models. The large cytoskeletal protein talin1 is not only pivotal for integrin activation, but also directly links integrins to the actin cytoskeleton. Here, we found that mice lacking talin1 specifically in podocytes display severe proteinuria, foot process effacement, and kidney failure. Loss of talin1 in podocytes caused only a modest reduction in β1 integrin activation, podocyte cell adhesion, and cell spreading; however, the actin cytoskeleton of podocytes was profoundly altered by the loss of talin1. Evaluation of murine models of glomerular injury and patients with nephrotic syndrome revealed that calpain-induced talin1 cleavage in podocytes might promote pathogenesis of nephrotic syndrome. Furthermore, pharmacologic inhibition of calpain activity following glomerular injury substantially reduced talin1 cleavage, albuminuria, and foot process effacement. Collectively, these findings indicate that podocyte talin1 is critical for maintaining the integrity of the glomerular filtration barrier and provide insight into the pathogenesis of nephrotic syndrome. PMID:24531545

  12. How Force Might Activate Talin's Vinculin Binding Sites: SMD Reveals a Structural Mechanism

    PubMed Central

    Hytönen, Vesa P; Vogel, Viola

    2008-01-01

    Upon cell adhesion, talin physically couples the cytoskeleton via integrins to the extracellular matrix, and subsequent vinculin recruitment is enhanced by locally applied tensile force. Since the vinculin binding (VB) sites are buried in the talin rod under equilibrium conditions, the structural mechanism of how vinculin binding to talin is force-activated remains unknown. Taken together with experimental data, a biphasic vinculin binding model, as derived from steered molecular dynamics, provides high resolution structural insights how tensile mechanical force applied to the talin rod fragment (residues 486–889 constituting helices H1–H12) might activate the VB sites. Fragmentation of the rod into three helix subbundles is prerequisite to the sequential exposure of VB helices to water. Finally, unfolding of a VB helix into a completely stretched polypeptide might inhibit further binding of vinculin. The first events in fracturing the H1–H12 rods of talin1 and talin2 in subbundles are similar. The proposed force-activated α-helix swapping mechanism by which vinculin binding sites in talin rods are exposed works distinctly different from that of other force-activated bonds, including catch bonds. PMID:18282082

  13. Mechanical unfolding reveals stable 3-helix intermediates in talin and α-catenin

    PubMed Central

    2018-01-01

    Mechanical stability is a key feature in the regulation of structural scaffolding proteins and their functions. Despite the abundance of α-helical structures among the human proteome and their undisputed importance in health and disease, the fundamental principles of their behavior under mechanical load are poorly understood. Talin and α-catenin are two key molecules in focal adhesions and adherens junctions, respectively. In this study, we used a combination of atomistic steered molecular dynamics (SMD) simulations, polyprotein engineering, and single-molecule atomic force microscopy (smAFM) to investigate unfolding of these proteins. SMD simulations revealed that talin rod α-helix bundles as well as α-catenin α-helix domains unfold through stable 3-helix intermediates. While the 5-helix bundles were found to be mechanically stable, a second stable conformation corresponding to the 3-helix state was revealed. Mechanically weaker 4-helix bundles easily unfolded into a stable 3-helix conformation. The results of smAFM experiments were in agreement with the findings of the computational simulations. The disulfide clamp mutants, designed to protect the stable state, support the 3-helix intermediate model in both experimental and computational setups. As a result, multiple discrete unfolding intermediate states in the talin and α-catenin unfolding pathway were discovered. Better understanding of the mechanical unfolding mechanism of α-helix proteins is a key step towards comprehensive models describing the mechanoregulation of proteins. PMID:29698481

  14. Talin does not associate exclusively with alpha 2b beta 3 integrin in activated human platelets.

    PubMed

    Escolar, G; Diaz-Ricart, M; White, J G

    1995-05-01

    Talin is a high-molecular-weight protein that may stabilize connections between cytoplasmic actin and the submembrane portion of glycoprotein IIb-IIIa (GPIIb-IIIa) (alpha 2b beta 3 integrin) in thrombin-stimulated human platelets. Using morphologic and electrophoretic techniques, we have examined the association of talin with the cytoskeleton of platelets activated by thrombin in the presence of fibrinogen-coated gold particles (Fgn/Au). Ultrastructural studies confirmed the presence of Fgn/Au firmly bound to the outside membranes of detergent-extracted platelets. Immunoblots of protein bands showed GPIIIa, but not talin, associated with cytoskeletons of activated platelets. Immunogold cytochemical techniques were performed on ultrathin cryosections of whole platelets to localize talin at the ultrastructural level. Studies were performed on normal platelets and platelets defective in GPIIb-IIIa (Glanzmann's thrombasthenia) and GPIb (Bernard-Soulier syndrome). Talin was randomly distributed in the cytoplasm of resting platelets. Activation resulted in binding of Fgn/Au to the surface membrane and redistribution of talin to the submembrane region. However, no definitive colocalization between the two markers was noted. Activated thrombasthenic platelets failed to bind Fgn/Au, but talin was localized to the submembrane location. After activation, talin was confined to the submembrane zone of Bernard-Soulier syndrome platelets. No definitive colocalization was observed between large clusters of Fgn/Au-occupied receptors and talin distributed in the submembrane region. GPIb and GPIIb-IIIa are not necessary for talin to localize in the submembrane region of activated cells. Talin does not redistribute exclusively with GPIIb-IIIa, and it may stabilize connections with other glycoproteins.

  15. Cell Adhesion-dependent Serine 85 Phosphorylation of Paxillin Modulates Focal Adhesion Formation and Haptotactic Migration via Association with the C-terminal Tail Domain of Talin*

    PubMed Central

    Kwak, Tae Kyoung; Lee, Mi-Sook; Ryu, Jihye; Choi, Yoon-Ju; Kang, Minkyung; Jeong, Doyoung; Lee, Jung Weon

    2012-01-01

    Integrin-mediated adhesion to extracellular matrix proteins is dynamically regulated during morphological changes and cell migration. Upon cell adhesion, protein-protein interactions among molecules at focal adhesions (FAs) play major roles in the regulation of cell morphogenesis and migration. Although tyrosine phosphorylation of paxillin is critically involved in adhesion-mediated signaling, the significance of paxillin phosphorylation at Ser-85 and the mechanism by which it regulates cell migration remain unclear. In this study, we examined how Ser-85 phosphorylation of paxillin affects FA formation and cell migration. We found that paxillin phosphorylation at Ser-85 occurred during HeLa cell adhesion to collagen I and was concomitant with tyrosine phosphorylation of both focal adhesion kinase and talin. However, the non-phosphorylatable S85A mutant of paxillin impaired cell spreading, FA turnover, and migration toward collagen I but not toward serum. Furthermore, whereas the (presumably indirect) interaction between paxillin and the C-terminal tail of talin led to dynamic FAs at the cell boundary, S85A paxillin did not bind talin and caused stabilized FAs in the central region of cells. Together, these observations suggest that cell adhesion-dependent Ser-85 phosphorylation of paxillin is important for its interaction with talin and regulation of dynamic FAs and cell migration. PMID:22761432

  16. In vivo quantitative analysis of Talin turnover in response to force

    PubMed Central

    Hákonardóttir, Guðlaug Katrín; López-Ceballos, Pablo; Herrera-Reyes, Alejandra Donají; Das, Raibatak; Coombs, Daniel; Tanentzapf, Guy

    2015-01-01

    Cell adhesion to the extracellular matrix (ECM) allows cells to form and maintain three-dimensional tissue architecture. Cell–ECM adhesions are stabilized upon exposure to mechanical force. In this study, we used quantitative imaging and mathematical modeling to gain mechanistic insight into how integrin-based adhesions respond to increased and decreased mechanical forces. A critical means of regulating integrin-based adhesion is provided by modulating the turnover of integrin and its adhesion complex (integrin adhesion complex [IAC]). The turnover of the IAC component Talin, a known mechanosensor, was analyzed using fluorescence recovery after photobleaching. Experiments were carried out in live, intact flies in genetic backgrounds that increased or decreased the force applied on sites of adhesion. This analysis showed that when force is elevated, the rate of assembly of new adhesions increases such that cell–ECM adhesion is stabilized. Moreover, under conditions of decreased force, the overall rate of turnover, but not the proportion of adhesion complex components undergoing turnover, increases. Using point mutations, we identify the key functional domains of Talin that mediate its response to force. Finally, by fitting a mathematical model to the data, we uncover the mechanisms that mediate the stabilization of ECM-based adhesion during development. PMID:26446844

  17. Tiam1 interaction with the PAR complex promotes talin-mediated Rac1 activation during polarized cell migration

    PubMed Central

    Wang, Shujie; Watanabe, Takashi; Matsuzawa, Kenji; Katsumi, Akira; Kakeno, Mai; Matsui, Toshinori; Ye, Feng; Sato, Kazuhide; Murase, Kiyoko; Sugiyama, Ikuko; Kimura, Kazushi; Mizoguchi, Akira; Ginsberg, Mark H.; Collard, John G.

    2012-01-01

    Migrating cells acquire front-rear polarity with a leading edge and a trailing tail for directional movement. The Rac exchange factor Tiam1 participates in polarized cell migration with the PAR complex of PAR3, PAR6, and atypical protein kinase C. However, it remains largely unknown how Tiam1 is regulated and contributes to the establishment of polarity in migrating cells. We show here that Tiam1 interacts directly with talin, which binds and activates integrins to mediate their signaling. Tiam1 accumulated at adhesions in a manner dependent on talin and the PAR complex. The interactions of talin with Tiam1 and the PAR complex were required for adhesion-induced Rac1 activation, cell spreading, and migration toward integrin substrates. Furthermore, Tiam1 acted with talin to regulate adhesion turnover. Thus, we propose that Tiam1, with the PAR complex, binds to integrins through talin and, together with the PAR complex, thereby regulates Rac1 activity and adhesion turnover for polarized migration. PMID:23071154

  18. Calpain-Mediated Proteolysis of Talin and FAK Regulates Adhesion Dynamics Necessary for Axon Guidance

    PubMed Central

    Kerstein, Patrick C.; Patel, Kevin M.

    2017-01-01

    Guidance of axons to their proper synaptic target sites requires spatially and temporally precise modulation of biochemical signals within growth cones. Ionic calcium (Ca2+) is an essential signal for axon guidance that mediates opposing effects on growth cone motility. The diverse effects of Ca2+ arise from the precise localization of Ca2+ signals into microdomains containing specific Ca2+ effectors. For example, differences in the mechanical and chemical composition of the underlying substrata elicit local Ca2+ signals within growth cone filopodia that regulate axon guidance through activation of the protease calpain. However, how calpain regulates growth cone motility remains unclear. Here, we identify the adhesion proteins talin and focal adhesion kinase (FAK) as proteolytic targets of calpain in Xenopus laevis spinal cord neurons both in vivo and in vitro. Inhibition of calpain increases the localization of endogenous adhesion signaling to growth cone filopodia. Using live cell microscopy and specific calpain-resistant point-mutants of talin (L432G) and FAK (V744G), we find that calpain inhibits paxillin-based adhesion assembly through cleavage of talin and FAK, and adhesion disassembly through cleavage of FAK. Blocking calpain cleavage of talin and FAK inhibits repulsive turning from focal uncaging of Ca2+ within filopodia. In addition, blocking calpain cleavage of talin and FAK in vivo promotes Rohon–Beard peripheral axon extension into the skin. These data demonstrate that filopodial Ca2+ signals regulate axon outgrowth and guidance through calpain regulation of adhesion dynamics through specific cleavage of talin and FAK. SIGNIFICANCE STATEMENT The proper formation of neuronal networks requires accurate guidance of axons and dendrites during development by motile structures known as growth cones. Understanding the intracellular signaling mechanisms that govern growth cone motility will clarify how the nervous system develops and regenerates, and may

  19. ADAP interactions with talin and kindlin promote platelet integrin αIIbβ3 activation and stable fibrinogen binding

    PubMed Central

    Kang, Jian; Kahner, Bryan; Ye, Feng; Ginsberg, Mark H.; Shattil, Sanford J.

    2014-01-01

    ADAP is a hematopoietic-restricted adapter protein that promotes integrin activation and is a carrier for other adapter proteins, Src kinase–associated phosphoprotein 1 (SKAP1) and SKAP2. In T lymphocytes, SKAP1 is the ADAP-associated molecule that activates integrins through direct linkages with Rap1 effectors (regulator of cell adhesion and polarization enriched in lymphoid tissues; Rap1-interacting adapter molecule). ADAP also promotes integrin αIIbβ3 activation in platelets, which lack SKAP1, suggesting an ADAP integrin–regulatory pathway different from those in lymphocytes. Here we characterized a novel association between ADAP and 2 essential integrin-β cytoplasmic tail-binding proteins involved in αIIbβ3 activation, talin and kindlin-3. Glutathione S-transferase pull-downs identified distinct regions in ADAP necessary for association with kindlin or talin. ADAP was physically proximal to talin and kindlin-3 in human platelets, as assessed biochemically, and by immunofluorescence microscopy and proximity ligation. Relative to wild-type mouse platelets, ADAP-deficient platelets exhibited reduced co-localization of talin with αIIbβ3, and reduced irreversible fibrinogen binding in response to a protease activated receptor 4 (PAR4) thrombin receptor agonist. When ADAP was heterologously expressed in Chinese hamster ovary cells co-expressing αIIbβ3, talin, PAR1, and kindlin-3, it associated with an αIIbβ3/talin complex and enabled kindlin-3 to promote agonist-dependent ligand binding to αIIbβ3. Thus, ADAP uniquely promotes activation of and irreversible fibrinogen binding to platelet αIIbβ3 through interactions with talin and kindlin-3. PMID:24523237

  20. Membrane-Induced Structural Rearrangement and Identification of a Novel Membrane Anchor in Talin F2F3

    PubMed Central

    Arcario, Mark J.; Tajkhorshid, Emad

    2014-01-01

    Experimental challenges associated with characterization of the membrane-bound form of talin have prevented us from understanding the molecular mechanism of its membrane-dependent integrin activation. Here, utilizing what we believe to be a novel membrane mimetic model, we present a reproducible model of membrane-bound talin observed across multiple independent simulations. We characterize both local and global membrane-induced structural transitions that successfully reconcile discrepancies between biochemical and structural studies and provide insight into how talin might modulate integrin function. Membrane binding of talin, captured in unbiased simulations, proceeds through three distinct steps: initial electrostatic recruitment of the F2 subdomain to anionic lipids via several basic residues; insertion of an initially buried, conserved hydrophobic anchor into the membrane; and association of the F3 subdomain with the membrane surface through a large, interdomain conformational change. These latter two steps, to our knowledge, have not been observed or described previously. Electrostatic analysis shows talin F2F3 to be highly polarized, with a highly positive underside, which we attribute to the initial electrostatic recruitment, and a negative top face, which can help orient the protein optimally with respect to the membrane, thereby reducing the number of unproductive membrane collision events. PMID:25418091

  1. Expression changes and novel interaction partners of talin 1 in effector cells of autoimmune uveitis.

    PubMed

    Degroote, Roxane L; Hauck, Stefanie M; Treutlein, Gudrun; Amann, Barbara; Fröhlich, Kristina J H; Kremmer, Elisabeth; Merl, Juliane; Stangassinger, Manfred; Ueffing, Marius; Deeg, Cornelia A

    2013-12-06

    Autoimmune uveitis is characterized by crossing of blood-retinal barrier (BRB) by autoaggressive immune cells. Equine recurrent uveitis (ERU) is a valuable spontaneous model for autoimmune uveitis and analyses of differentially expressed proteins in ERU unraveled changed protein clusters in target tissues and immune system. Healthy eyes are devoid of leukocytes. In ERU, however, leukocytes enter the inner eye and subsequently destroy it. Molecular mechanisms enabling cell migration through BRB still remain elusive. Previously, we detected decreased talin 1 expression in blood-derived granulocytes of ERU cases, linking the innate immune system to ERU. Because changes in leukocyte protein expression pattern may play a role in pathological abnormalities leading to migration ability, we aimed at identifying interactors of talin 1 in leukocytes with immunoprecipitation, followed by LC-MS/MS for candidate identification. This enabled us to identify CD90 (Thy1) as novel interactor of talin 1 besides several other interactors. In blood-derived granulocytes from healthy individuals, CD90 was highly abundant and significantly reduced in ERU, especially in effector cells. Connection between talin 1 and CD90 and their expression differences in inflammation is an interesting novel finding allowing deeper insight into immune response of innate immune system and granulocyte migration ability in this organ-specific autoimmune disease.

  2. PO-12 - The key role of talin-1 in cancer cell extravasation dissected through human vascularized 3D microfluidic model.

    PubMed

    Gilardi, M; Bersini, S; Calleja, A Boussomier; Kamm, R D; Vanoni, M; Moretti, M

    2016-04-01

    Metastases are responsible for more than 90% of cancer related mortality. The hematogenous metastatic invasion is a complex process in which the endothelium plays a key role. Extravasation is a dynamic process involving remodeling and change in cell shape and in cytoskeleton whereby a series of strongly dependent interactions between CTCs and endothelium occurs [1]. Talins are proteins regulating focal adhesions and cytoskeleton remodeling. Talin-1 seems to be involved in the aggressiveness, motility, survival and invadopodia formation of cancer cells throughout the entire metastatic cascade [2], being up-regulated in breast cancer cells and mutated in sarcomas. Understand the implication of talin-1 in extravasation could facilitate the design of new therapies and finally fight cancer. We hypothesized that Talin-1 could be specifically involved in extravasation driving each of its steps. We developed a human 3D microfluidic model that enables the study of human cancer cell extravasation within a perfusable human microvascularized organ specific environment[3]. For the study of extravasation we applied microfluidic approach through the development of a microfluidic device in which endothelial cells and fibroblasts generated a 3D human functional vascular networks. Microvessel characterization was performed with immunofluorescence and permeability assays. We knocked-down talin-1 in triple negative breast cancer cell line MDA-MB231 and metastatic fibro-sarcoma cell line HT1080 with SiRNA and verified by Western-blot. Cancer cells were then perfused in the vessels and extravasation monitored through confocal imaging. We developed a human vascularized 3D microfluidic device with human perfusable capillary-like structures embedded in fibrin matrix, characterized by mature endothelium markers and physiological permeability (1.5±0.76)×10(-6) cm/s. We focused on the role of Talin-1 in adhesion to endothelium, trans-endothelial migration (TEM) and early invasion. Adhesion

  3. Integrin {alpha}{beta}1, {alpha}{sub v}{beta}, {alpha}{sub 6}{beta} effectors p130Cas, Src and talin regulate carcinoma invasion and chemoresistance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sansing, Hope A.; Sarkeshik, Ali; Yates, John R.

    2011-03-11

    Research highlights: {yields} Proteomics of clustered integrin {alpha}{beta}1, {alpha}{sub v}{beta}, {alpha}{sub 6}{beta} receptors in oral carcinoma. {yields} p130Cas, Dek, Src and talin regulate oral carcinoma invasion. {yields} p130Cas, talin, Src and zyxin regulate oral carcinoma resistance to cisplatin. -- Abstract: Ligand engagement by integrins induces receptor clustering and formation of complexes at the integrin cytoplasmic face that controls cell signaling and cytoskeletal dynamics critical for adhesion-dependent processes. This study searches for a subset of integrin effectors that coordinates both tumor cell invasion and resistance to the chemotherapeutic drug cisplatin in oral carcinomas. Candidate integrin effectors were identified in a proteomicsmore » screen of proteins recruited to clustered integrin {alpha}{beta}1, {alpha}{sub v}{beta} or {alpha}{sub 6}{beta} receptors in oral carcinomas. Proteins with diverse functions including microtubule and actin binding proteins, and factors involved in trafficking, transcription and translation were identified in oral carcinoma integrin complexes. Knockdown of effectors in the oral carcinoma HN12 cells revealed that p130Cas, Dek, Src and talin were required for invasion through Matrigel. Disruption of talin or p130Cas by RNA interference increased resistance to cisplatin, whereas targeting Dek, Src or zyxin reduced HN12 resistance to cisplatin. Analysis of the spreading of HN12 cells on collagen I and laminin I revealed that a decrease in p130Cas or talin expression inhibited spreading on both matrices. Interestingly, a reduction in zyxin expression enhanced spreading on laminin I and inhibited spreading on collagen I. Reduction of Dek, Src, talin or zyxin expression reduced HN12 proliferation by 30%. Proliferation was not affected by a reduction in p130Cas expression. We conclude that p130Cas, Src and talin function in both oral carcinoma invasion and resistance to cisplatin.« less

  4. The influenza virus neuraminidase protein transmembrane and head domains have coevolved.

    PubMed

    da Silva, Diogo V; Nordholm, Johan; Dou, Dan; Wang, Hao; Rossman, Jeremy S; Daniels, Robert

    2015-01-15

    Transmembrane domains (TMDs) from single-spanning membrane proteins are commonly viewed as membrane anchors for functional domains. Influenza virus neuraminidase (NA) exemplifies this concept, as it retains enzymatic function upon proteolytic release from the membrane. However, the subtype 1 NA TMDs have become increasingly more polar in human strains since 1918, which suggests that selection pressure exists on this domain. Here, we investigated the N1 TMD-head domain relationship by exchanging a prototypical "old" TMD (1933) with a "recent" (2009), more polar TMD and an engineered hydrophobic TMD. Each exchange altered the TMD association, decreased the NA folding efficiency, and significantly reduced viral budding and replication at 37°C compared to at 33°C, at which NA folds more efficiently. Passaging the chimera viruses at 37°C restored the NA folding efficiency, viral budding, and infectivity by selecting for NA TMD mutations that correspond with their polar or hydrophobic assembly properties. These results demonstrate that single-spanning membrane protein TMDs can influence distal domain folding, as well as membrane-related processes, and suggest the NA TMD in H1N1 viruses has become more polar to maintain compatibility with the evolving enzymatic head domain. The neuraminidase (NA) protein from influenza A viruses (IAVs) functions to promote viral release and is one of the major surface antigens. The receptor-destroying activity in NA resides in the distal head domain that is linked to the viral membrane by an N-terminal hydrophobic transmembrane domain (TMD). Over the last century, the subtype 1 NA TMDs (N1) in human H1N1 viruses have become increasingly more polar, and the head domains have changed to alter their antigenicity. Here, we provide the first evidence that an "old" N1 head domain from 1933 is incompatible with a "recent" (2009), more polar N1 TMD sequence and that, during viral replication, the head domain drives the selection of TMD

  5. Nitric oxide inhibits calpain-mediated proteolysis of talin in skeletal muscle cells

    NASA Technical Reports Server (NTRS)

    Koh, T. J.; Tidball, J. G.

    2000-01-01

    We tested the hypothesis that nitric oxide can inhibit cytoskeletal breakdown in skeletal muscle cells by inhibiting calpain cleavage of talin. The nitric oxide donor sodium nitroprusside prevented many of the effects of calcium ionophore on C(2)C(12) muscle cells, including preventing talin proteolysis and release into the cytosol and reducing loss of vinculin, cell detachment, and loss of cellular protein. These results indicate that nitric oxide inhibition of calpain protected the cells from ionophore-induced proteolysis. Calpain inhibitor I and a cell-permeable calpastatin peptide also protected the cells from proteolysis, confirming that ionophore-induced proteolysis was primarily calpain mediated. The activity of m-calpain in a casein zymogram was inhibited by sodium nitroprusside, and this inhibition was reversed by dithiothreitol. Previous incubation with the active site-targeted calpain inhibitor I prevented most of the sodium nitroprusside-induced inhibition of m-calpain activity. These data suggest that nitric oxide inhibited m-calpain activity via S-nitrosylation of the active site cysteine. The results of this study indicate that nitric oxide produced endogenously by skeletal muscle and other cell types has the potential to inhibit m-calpain activity and cytoskeletal proteolysis.

  6. Bartonella henselae engages inside-out and outside-in signaling by integrin β1 and talin1 during invasome-mediated bacterial uptake.

    PubMed

    Truttmann, Matthias C; Misselwitz, Benjamin; Huser, Sonja; Hardt, Wolf-Dietrich; Critchley, David R; Dehio, Christoph

    2011-11-01

    The VirB/D4 type IV secretion system (T4SS) of the bacterial pathogen Bartonella henselae (Bhe) translocates seven effector proteins (BepA-BepG) into human cells that subvert host cellular functions. Two redundant pathways dependent on BepG or the combination of BepC and BepF trigger the formation of a bacterial uptake structure termed the invasome. Invasome formation is a multi-step process consisting of bacterial adherence, effector translocation, aggregation of bacteria on the cell surface and engulfment, and eventually, complete internalization of the bacterial aggregate occurs in an F-actin-dependent manner. In the present study, we show that Bhe-triggered invasome formation depends on integrin-β1-mediated signaling cascades that enable assembly of the F-actin invasome structure. We demonstrate that Bhe interacts with integrin β1 in a fibronectin- and VirB/D4 T4SS-independent manner and that activated integrin β1 is essential for both effector translocation and the actin rearrangements leading to invasome formation. Furthermore, we show that talin1, but not talin2, is required for inside-out activation of integrin β1 during invasome formation. Finally, integrin-β1-mediated outside-in signaling by FAK, Src, paxillin and vinculin is necessary for invasome formation. This is the first example of a bacterial entry process that fully exploits the bi-directional signaling capacity of integrin receptors in a talin1-specific manner.

  7. Emergence and subsequent functional specialization of kindlins during evolution of cell adhesiveness

    PubMed Central

    Meller, Julia; Rogozin, Igor B.; Poliakov, Eugenia; Meller, Nahum; Bedanov-Pack, Mark; Plow, Edward F.; Qin, Jun; Podrez, Eugene A.; Byzova, Tatiana V.

    2015-01-01

    Kindlins are integrin-interacting proteins essential for integrin-mediated cell adhesiveness. In this study, we focused on the evolutionary origin and functional specialization of kindlins as a part of the evolutionary adaptation of cell adhesive machinery. Database searches revealed that many members of the integrin machinery (including talin and integrins) existed before kindlin emergence in evolution. Among the analyzed species, all metazoan lineages—but none of the premetazoans—had at least one kindlin-encoding gene, whereas talin was present in several premetazoan lineages. Kindlin appears to originate from a duplication of the sequence encoding the N-terminal fragment of talin (the talin head domain) with a subsequent insertion of the PH domain of separate origin. Sequence analysis identified a member of the actin filament–associated protein 1 (AFAP1) superfamily as the most likely origin of the kindlin PH domain. The functional divergence between kindlin paralogues was assessed using the sequence swap (chimera) approach. Comparison of kindlin 2 (K2)/kindlin 3 (K3) chimeras revealed that the F2 subdomain, in particular its C-terminal part, is crucial for the differential functional properties of K2 and K3. The presence of this segment enables K2 but not K3 to localize to focal adhesions. Sequence analysis of the C-terminal part of the F2 subdomain of K3 suggests that insertion of a variable glycine-rich sequence in vertebrates contributed to the loss of constitutive K3 targeting to focal adhesions. Thus emergence and subsequent functional specialization of kindlins allowed multicellular organisms to develop additional tissue-specific adaptations of cell adhesiveness. PMID:25540429

  8. Domain decomposition and matching for time-domain analysis of motions of ships advancing in head sea

    NASA Astrophysics Data System (ADS)

    Tang, Kai; Zhu, Ren-chuan; Miao, Guo-ping; Fan, Ju

    2014-08-01

    A domain decomposition and matching method in the time-domain is outlined for simulating the motions of ships advancing in waves. The flow field is decomposed into inner and outer domains by an imaginary control surface, and the Rankine source method is applied to the inner domain while the transient Green function method is used in the outer domain. Two initial boundary value problems are matched on the control surface. The corresponding numerical codes are developed, and the added masses, wave exciting forces and ship motions advancing in head sea for Series 60 ship and S175 containership, are presented and verified. A good agreement has been obtained when the numerical results are compared with the experimental data and other references. It shows that the present method is more efficient because of the panel discretization only in the inner domain during the numerical calculation, and good numerical stability is proved to avoid divergence problem regarding ships with flare.

  9. Domain wall assisted GMR head with spin-Hall effect

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Arun, R., E-mail: arunbdu@gmail.com; Sabareesan, P., E-mail: sendtosabari@gmail.com; Daniel, M., E-mail: danielcnld@gmail.com

    2016-05-06

    We theoretically study the dynamics of a field induced domain wall in the Py/Pt bi-layer structure in the presence of spin-Hall effect (SHE) by solving the Landau-Lifshitz-Gilbert (LLG) equation along with the adiabatic, nonadiabatic and SHE spin-transfer torques (STTs). It is observed that a weak magnetic field moves the domain wall with high velocity in the presence of SHE and the direction of the velocity is changed by changing the direction of the weak field. The numerical results show that the magnetization of the ferromagnetic layer can be reversed quickly through domain wall motion by changing the direction of amore » weak external field in the presence of SHE while the direction of current is fixed. The SHE reduces the magnetization reversal time of 1000 nm length strip by 14.7 ns. This study is extended to model a domain wall based GMR (Giant Magnetoresistance) read head with SHE.« less

  10. Human adenovirus serotypes 3 and 5 bind to two different cellular receptors via the fiber head domain.

    PubMed Central

    Stevenson, S C; Rollence, M; White, B; Weaver, L; McClelland, A

    1995-01-01

    The adenovirus fiber protein is responsible for attachment of the virion to cell surface receptors. The identity of the cellular receptor which mediates binding is unknown, although there is evidence suggesting that two distinct adenovirus receptors interact with the group C (adenovirus type 5 [Ad5]) and the group B (Ad3) adenoviruses. In order to define the determinants of adenovirus receptor specificity, we have carried out a series of competition binding experiments using recombinant native fiber polypeptides from Ad5 and Ad3 and chimeric fiber proteins in which the head domains of Ad5 and Ad3 were exchanged. Specific binding of fiber to HeLa cell receptors was assessed with radiolabeled protein synthesized in vitro, and by competition analysis with baculovirus-expressed fiber protein. Fiber produced in vitro was found as both monomer and trimer, but only the assembled trimers had receptor binding activity. Competition data support the conclusion that Ad5 and Ad3 interact with different cellular receptors. The Ad5 receptor distribution on several cell lines was assessed with a fiber binding flow cytometric assay. HeLa cells were found to express high levels of receptor, while CHO and human diploid fibroblasts did not. A chimeric fiber containing the Ad5 fiber head domain blocked the binding of Ad5 fiber but not Ad3 fiber. Similarly, a chimeric fiber containing the Ad3 fiber head blocked the binding of labeled Ad3 fiber but not Ad5 fiber. In addition, the isolated Ad3 fiber head domain competed effectively with labeled Ad3 fiber for binding to HeLa cell receptors. These results demonstrate that the determinants of receptor binding are located in the head domain of the fiber and that the isolated head domain is capable of trimerization and binding to cellular receptors. Our results also show that it is possible to change the receptor specificity of the fiber protein by manipulation of sequences contained in the head domain. Modification or replacement of the fiber

  11. The conformation of myosin head domains in rigor muscle determined by X-ray interference.

    PubMed

    Reconditi, M; Koubassova, N; Linari, M; Dobbie, I; Narayanan, T; Diat, O; Piazzesi, G; Lombardi, V; Irving, M

    2003-08-01

    In the absence of adenosine triphosphate, the head domains of myosin cross-bridges in muscle bind to actin filaments in a rigor conformation that is expected to mimic that following the working stroke during active contraction. We used x-ray interference between the two head arrays in opposite halves of each myosin filament to determine the rigor head conformation in single fibers from frog skeletal muscle. During isometric contraction (force T(0)), the interference effect splits the M3 x-ray reflection from the axial repeat of the heads into two peaks with relative intensity (higher angle/lower angle peak) 0.76. In demembranated fibers in rigor at low force (<0.05 T(0)), the relative intensity was 4.0, showing that the center of mass of the heads had moved 4.5 nm closer to the midpoint of the myosin filament. When rigor fibers were stretched, increasing the force to 0.55 T(0), the heads' center of mass moved back by 1.1-1.6 nm. These motions can be explained by tilting of the light chain domain of the head so that the mean angle between the Cys(707)-Lys(843) vector and the filament axis increases by approximately 36 degrees between isometric contraction and low-force rigor, and decreases by 7-10 degrees when the rigor fiber is stretched to 0.55 T(0).

  12. Thrombospondin Type-1 Repeat Domain-Containing Proteins Are Strongly Expressed in the Head Region of Hydra.

    PubMed

    Hamaguchi-Hamada, Kayoko; Kurumata-Shigeto, Mami; Minobe, Sumiko; Fukuoka, Nozomi; Sato, Manami; Matsufuji, Miyuki; Koizumi, Osamu; Hamada, Shun

    2016-01-01

    The head region of Hydra, the hypostome, is a key body part for developmental control and the nervous system. We herein examined genes specifically expressed in the head region of Hydra oligactis using suppression subtractive hybridization (SSH) cloning. A total of 1414 subtracted clones were sequenced and found to be derived from at least 540 different genes by BLASTN analyses. Approximately 25% of the subtracted clones had sequences encoding thrombospondin type-1 repeat (TSR) domains, and were derived from 17 genes. We identified 11 TSR domain-containing genes among the top 36 genes that were the most frequently detected in our SSH library. Whole-mount in situ hybridization analyses confirmed that at least 13 out of 17 TSR domain-containing genes were expressed in the hypostome of Hydra oligactis. The prominent expression of TSR domain-containing genes suggests that these genes play significant roles in the hypostome of Hydra oligactis.

  13. Thrombospondin Type-1 Repeat Domain-Containing Proteins Are Strongly Expressed in the Head Region of Hydra

    PubMed Central

    Hamaguchi-Hamada, Kayoko; Kurumata-Shigeto, Mami; Minobe, Sumiko; Fukuoka, Nozomi; Sato, Manami; Matsufuji, Miyuki; Koizumi, Osamu; Hamada, Shun

    2016-01-01

    The head region of Hydra, the hypostome, is a key body part for developmental control and the nervous system. We herein examined genes specifically expressed in the head region of Hydra oligactis using suppression subtractive hybridization (SSH) cloning. A total of 1414 subtracted clones were sequenced and found to be derived from at least 540 different genes by BLASTN analyses. Approximately 25% of the subtracted clones had sequences encoding thrombospondin type-1 repeat (TSR) domains, and were derived from 17 genes. We identified 11 TSR domain-containing genes among the top 36 genes that were the most frequently detected in our SSH library. Whole-mount in situ hybridization analyses confirmed that at least 13 out of 17 TSR domain-containing genes were expressed in the hypostome of Hydra oligactis. The prominent expression of TSR domain-containing genes suggests that these genes play significant roles in the hypostome of Hydra oligactis. PMID:27043211

  14. The bilaterian head patterning gene six3/6 controls aboral domain development in a cnidarian.

    PubMed

    Sinigaglia, Chiara; Busengdal, Henriette; Leclère, Lucas; Technau, Ulrich; Rentzsch, Fabian

    2013-01-01

    The origin of the bilaterian head is a fundamental question for the evolution of animal body plans. The head of bilaterians develops at the anterior end of their primary body axis and is the site where the brain is located. Cnidarians, the sister group to bilaterians, lack brain-like structures and it is not clear whether the oral, the aboral, or none of the ends of the cnidarian primary body axis corresponds to the anterior domain of bilaterians. In order to understand the evolutionary origin of head development, we analysed the function of conserved genetic regulators of bilaterian anterior development in the sea anemone Nematostella vectensis. We show that orthologs of the bilaterian anterior developmental genes six3/6, foxQ2, and irx have dynamic expression patterns in the aboral region of Nematostella. Functional analyses reveal that NvSix3/6 acts upstream of NvFoxQ2a as a key regulator of the development of a broad aboral territory in Nematostella. NvSix3/6 initiates an autoregulatory feedback loop involving positive and negative regulators of FGF signalling, which subsequently results in the downregulation of NvSix3/6 and NvFoxQ2a in a small domain at the aboral pole, from which the apical organ develops. We show that signalling by NvFGFa1 is specifically required for the development of the apical organ, whereas NvSix3/6 has an earlier and broader function in the specification of the aboral territory. Our functional and gene expression data suggest that the head-forming region of bilaterians is derived from the aboral domain of the cnidarian-bilaterian ancestor.

  15. The Bilaterian Head Patterning Gene six3/6 Controls Aboral Domain Development in a Cnidarian

    PubMed Central

    Sinigaglia, Chiara; Busengdal, Henriette; Leclère, Lucas; Technau, Ulrich; Rentzsch, Fabian

    2013-01-01

    The origin of the bilaterian head is a fundamental question for the evolution of animal body plans. The head of bilaterians develops at the anterior end of their primary body axis and is the site where the brain is located. Cnidarians, the sister group to bilaterians, lack brain-like structures and it is not clear whether the oral, the aboral, or none of the ends of the cnidarian primary body axis corresponds to the anterior domain of bilaterians. In order to understand the evolutionary origin of head development, we analysed the function of conserved genetic regulators of bilaterian anterior development in the sea anemone Nematostella vectensis. We show that orthologs of the bilaterian anterior developmental genes six3/6, foxQ2, and irx have dynamic expression patterns in the aboral region of Nematostella. Functional analyses reveal that NvSix3/6 acts upstream of NvFoxQ2a as a key regulator of the development of a broad aboral territory in Nematostella. NvSix3/6 initiates an autoregulatory feedback loop involving positive and negative regulators of FGF signalling, which subsequently results in the downregulation of NvSix3/6 and NvFoxQ2a in a small domain at the aboral pole, from which the apical organ develops. We show that signalling by NvFGFa1 is specifically required for the development of the apical organ, whereas NvSix3/6 has an earlier and broader function in the specification of the aboral territory. Our functional and gene expression data suggest that the head-forming region of bilaterians is derived from the aboral domain of the cnidarian-bilaterian ancestor. PMID:23483856

  16. Regulatory coiled-coil domains promote head-to-head assemblies of AAA+ chaperones essential for tunable activity control.

    PubMed

    Carroni, Marta; Franke, Kamila B; Maurer, Michael; Jäger, Jasmin; Hantke, Ingo; Gloge, Felix; Linder, Daniela; Gremer, Sebastian; Turgay, Kürşad; Bukau, Bernd; Mogk, Axel

    2017-11-22

    Ring-forming AAA+ chaperones exert ATP-fueled substrate unfolding by threading through a central pore. This activity is potentially harmful requiring mechanisms for tight repression and substrate-specific activation. The AAA+ chaperone ClpC with the peptidase ClpP forms a bacterial protease essential to virulence and stress resistance. The adaptor MecA activates ClpC by targeting substrates and stimulating ClpC ATPase activity. We show how ClpC is repressed in its ground state by determining ClpC cryo-EM structures with and without MecA. ClpC forms large two-helical assemblies that associate via head-to-head contacts between coiled-coil middle domains (MDs). MecA converts this resting state to an active planar ring structure by binding to MD interaction sites. Loss of ClpC repression in MD mutants causes constitutive activation and severe cellular toxicity. These findings unravel an unexpected regulatory concept executed by coiled-coil MDs to tightly control AAA+ chaperone activity.

  17. Ubiquitination of the Dishevelled DIX domain blocks its head-to-tail polymerization

    PubMed Central

    Madrzak, Julia; Fiedler, Marc; Johnson, Christopher M.; Ewan, Richard; Knebel, Axel; Bienz, Mariann; Chin, Jason W.

    2015-01-01

    Dishevelled relays Wnt signals from the plasma membrane to different cytoplasmic effectors. Its signalling activity depends on its DIX domain, which undergoes head-to-tail polymerization to assemble signalosomes. The DIX domain is ubiquitinated in vivo at multiple lysines, which can be antagonized by various deubiquitinases (DUBs) including the CYLD tumour suppressor that attenuates Wnt signalling. Here, we generate milligram quantities of pure human Dvl2 DIX domain mono-ubiquitinated at two lysines (K54 and K58) by genetically encoded orthogonal protection with activated ligation (GOPAL), to investigate their effect on DIX polymerization. We show that the ubiquitination of DIX at K54 blocks its polymerization in solution, whereas DIX58-Ub remains oligomerization-competent. DUB profiling identified 28 DUBs that cleave DIX-ubiquitin conjugates, half of which prefer, or are specific for, DIX54-Ub, including Cezanne and CYLD. These DUBs thus have the potential to promote Dvl polymerization and signalosome formation, rather than antagonize it as previously thought for CYLD. PMID:25907794

  18. Comparison of a layered slab and an atlas head model for Monte Carlo fitting of time-domain near-infrared spectroscopy data of the adult head

    PubMed Central

    Selb, Juliette; Ogden, Tyler M.; Dubb, Jay; Fang, Qianqian; Boas, David A.

    2014-01-01

    Abstract. Near-infrared spectroscopy (NIRS) estimations of the adult brain baseline optical properties based on a homogeneous model of the head are known to introduce significant contamination from extracerebral layers. More complex models have been proposed and occasionally applied to in vivo data, but their performances have never been characterized on realistic head structures. Here we implement a flexible fitting routine of time-domain NIRS data using graphics processing unit based Monte Carlo simulations. We compare the results for two different geometries: a two-layer slab with variable thickness of the first layer and a template atlas head registered to the subject’s head surface. We characterize the performance of the Monte Carlo approaches for fitting the optical properties from simulated time-resolved data of the adult head. We show that both geometries provide better results than the commonly used homogeneous model, and we quantify the improvement in terms of accuracy, linearity, and cross-talk from extracerebral layers. PMID:24407503

  19. Extra-domain B in oncofetal fibronectin structurally promotes fibrillar head-to-tail dimerization of extracellular matrix protein.

    PubMed

    Schiefner, André; Gebauer, Michaela; Skerra, Arne

    2012-05-18

    The type III extra-domain B (ED-B) is specifically spliced into fibronectin (Fn) during embryogenesis and neoangiogenesis, including many cancers. The x-ray structure of the recombinant four-domain fragment Fn(III)7B89 reveals a tightly associated, extended head-to-tail dimer, which is stabilized via pair-wise shape and charge complementarity. A tendency toward ED-B-dependent dimer formation in solution was supported by size exclusion chromatography and analytical ultracentrifugation. When amending the model with the known three-dimensional structure of the Fn(III)10 domain, its RGD loop as well as the adhesion synergy region in Fn(III)9-10 become displayed on the same face of the dimer; this should allow simultaneous binding of at least two integrins and, thus, receptor clustering on the cell surface and intracellular signaling. Insertion of ED-B appears to stabilize overall head-to-tail dimerization of two separate Fn chains, which, together with alternating homodimer formation via disulfide bridges at the C-terminal Fn tail, should lead to the known macromolecular fibril formation.

  20. The role of the proline-rich domain of Ssdp1 in the modular architecture of the vertebrate head organizer

    PubMed Central

    Enkhmandakh, Badam; Makeyev, Alexandr V.; Bayarsaihan, Dashzeveg

    2006-01-01

    Lim1, Ssdp1, and Ldb1 proteins are components of the Ldb1-associated transcriptional complex, which is important in the head-organizing activity during early mouse development. Depletion of each individual protein alone causes a headless phenotype. To explore in more detail the modular architecture of the complex, we have generated two different gene-trapped mouse lines that express truncated forms of Ssdp1. Embryos derived from the gene-trapped line that encodes a truncated Ssdp1 lacking the proline-rich sequence exhibit a lethal abnormal head-development phenotype, resembling mouse embryos deficient for Lim1, Ssdp1, or Otx2 genes. Embryos derived from the second gene-trapped line, in which most of the proline-rich domain of Ssdp1 is retained, did not show abnormalities in head development. Our data demonstrate that components of the Ldb1-dependent module can be subdivided further into discrete functional domains and that the proline-rich stretch of Ssdp1 is critical for embryonic head development. Furthermore, phylogenetic comparisons revealed that in Caenorhabditis elegans, a similar proline-rich sequence is absent in Ssdp but present in Ldb1. We conclude that although the overall architecture of the Ldb1-dependent module has been preserved, the genetic specification of its individual components has diversified during evolution, without compromising the function of the module. PMID:16864769

  1. The role of the proline-rich domain of Ssdp1 in the modular architecture of the vertebrate head organizer.

    PubMed

    Enkhmandakh, Badam; Makeyev, Alexandr V; Bayarsaihan, Dashzeveg

    2006-08-01

    Lim1, Ssdp1, and Ldb1 proteins are components of the Ldb1-associated transcriptional complex, which is important in the head-organizing activity during early mouse development. Depletion of each individual protein alone causes a headless phenotype. To explore in more detail the modular architecture of the complex, we have generated two different gene-trapped mouse lines that express truncated forms of Ssdp1. Embryos derived from the gene-trapped line that encodes a truncated Ssdp1 lacking the proline-rich sequence exhibit a lethal abnormal head-development phenotype, resembling mouse embryos deficient for Lim1, Ssdp1, or Otx2 genes. Embryos derived from the second gene-trapped line, in which most of the proline-rich domain of Ssdp1 is retained, did not show abnormalities in head development. Our data demonstrate that components of the Ldb1-dependent module can be subdivided further into discrete functional domains and that the proline-rich stretch of Ssdp1 is critical for embryonic head development. Furthermore, phylogenetic comparisons revealed that in Caenorhabditis elegans, a similar proline-rich sequence is absent in Ssdp but present in Ldb1. We conclude that although the overall architecture of the Ldb1-dependent module has been preserved, the genetic specification of its individual components has diversified during evolution, without compromising the function of the module.

  2. Structural and Functional Characterization of the Kindlin-1 Pleckstrin Homology Domain*

    PubMed Central

    Yates, Luke A.; Lumb, Craig N.; Brahme, Nina N.; Zalyte, Ruta; Bird, Louise E.; De Colibus, Luigi; Owens, Raymond J.; Calderwood, David A.; Sansom, Mark S. P.; Gilbert, Robert J. C.

    2012-01-01

    Inside-out activation of integrins is mediated via the binding of talin and kindlin to integrin β-subunit cytoplasmic tails. The kindlin FERM domain is interrupted by a pleckstrin homology (PH) domain within its F2 subdomain. Here, we present data confirming the importance of the kindlin-1 PH domain for integrin activation and its x-ray crystal structure at a resolution of 2.1 Å revealing a C-terminal second α-helix integral to the domain but found only in the kindlin protein family. An isoform-specific salt bridge occludes the canonical phosphoinositide binding site, but molecular dynamics simulations display transient switching to an alternative open conformer. Molecular docking reveals that the opening of the pocket would enable potential ligands to bind within it. Although lipid overlay assays suggested the PH domain binds inositol monophosphates, surface plasmon resonance demonstrated weak affinities for inositol 3,4,5-triphosphate (Ins(3,4,5)P3; KD ∼100 μm) and no monophosphate binding. Removing the salt bridge by site-directed mutagenesis increases the PH domain affinity for Ins(3,4,5)P3 as measured by surface plasmon resonance and enables it to bind PtdIns(3,5)P2 on a dot-blot. Structural comparison with other PH domains suggests that the phosphate binding pocket in the kindlin-1 PH domain is more occluded than in kindlins-2 and -3 due to its salt bridge. In addition, the apparent affinity for Ins(3,4,5)P3 is affected by the presence of PO4 ions in the buffer. We suggest the physiological ligand of the kindlin-1 PH domain is most likely not an inositol phosphate but another phosphorylated species. PMID:23132860

  3. Effects of head geometry simplifications on acoustic radiation of vowel sounds based on time-domain finite-element simulations.

    PubMed

    Arnela, Marc; Guasch, Oriol; Alías, Francesc

    2013-10-01

    One of the key effects to model in voice production is that of acoustic radiation of sound waves emanating from the mouth. The use of three-dimensional numerical simulations allows to naturally account for it, as well as to consider all geometrical head details, by extending the computational domain out of the vocal tract. Despite this advantage, many approximations to the head geometry are often performed for simplicity and impedance load models are still used as well to reduce the computational cost. In this work, the impact of some of these simplifications on radiation effects is examined for vowel production in the frequency range 0-10 kHz, by means of comparison with radiation from a realistic head. As a result, recommendations are given on their validity depending on whether high frequency energy (above 5 kHz) should be taken into account or not.

  4. Altered expression of talin 1 in peripheral immune cells points to a significant role of the innate immune system in spontaneous autoimmune uveitis.

    PubMed

    Degroote, Roxane L; Hauck, Stefanie M; Kremmer, Elisabeth; Amann, Barbara; Ueffing, Marius; Deeg, Cornelia A

    2012-07-19

    The molecular mechanism which enables activated immune cells to cross the blood-retinal barrier in spontaneous autoimmune uveitis is yet to be unraveled. Equine recurrent uveitis is the only spontaneous animal model allowing us to investigate the autoimmune mediated transformation of leukocytes in the course of this sight threatening disease. Hypothesizing that peripheral blood immune cells change their protein expression pattern in spontaneous autoimmune uveitis, we used DIGE to detect proteins with altered abundance comparing peripheral immune cells of healthy and ERU diseased horses. Among others, we found a significant downregulation of talin 1 in peripheral blood granulocytes of ERU specimen, pointing to changes in β integrin activation and indicating a significant role of the innate immune system in spontaneous autoimmune diseases. Copyright © 2012. Published by Elsevier B.V.

  5. Curvature-induced domain wall pinning

    NASA Astrophysics Data System (ADS)

    Yershov, Kostiantyn V.; Kravchuk, Volodymyr P.; Sheka, Denis D.; Gaididei, Yuri

    2015-09-01

    It is shown that a local bend of a nanowire is a source of pinning potential for a transversal head-to-head (tail-to-tail) domain wall. Eigenfrequency of the domain wall free oscillations at the pinning potential and the effective friction are determined as functions of the curvature and domain wall width. The pinning potential originates from the effective curvature-induced Dzyaloshinsky-like term in the exchange energy. The theoretical results are verified by means of micromagnetic simulations for the case of parabolic shape of the wire bend.

  6. Structure of a Burkholderia pseudomallei Trimeric Autotransporter Adhesin Head

    PubMed Central

    Edwards, Thomas E.; Phan, Isabelle; Abendroth, Jan; Dieterich, Shellie H.; Masoudi, Amir; Guo, Wenjin; Hewitt, Stephen N.; Kelley, Angela; Leibly, David; Brittnacher, Mitch J.; Staker, Bart L.; Miller, Samuel I.; Van Voorhis, Wesley C.; Myler, Peter J.; Stewart, Lance J.

    2010-01-01

    Background Pathogenic bacteria adhere to the host cell surface using a family of outer membrane proteins called Trimeric Autotransporter Adhesins (TAAs). Although TAAs are highly divergent in sequence and domain structure, they are all conceptually comprised of a C-terminal membrane anchoring domain and an N-terminal passenger domain. Passenger domains consist of a secretion sequence, a head region that facilitates binding to the host cell surface, and a stalk region. Methodology/Principal Findings Pathogenic species of Burkholderia contain an overabundance of TAAs, some of which have been shown to elicit an immune response in the host. To understand the structural basis for host cell adhesion, we solved a 1.35 Å resolution crystal structure of a BpaA TAA head domain from Burkholderia pseudomallei, the pathogen that causes melioidosis. The structure reveals a novel fold of an intricately intertwined trimer. The BpaA head is composed of structural elements that have been observed in other TAA head structures as well as several elements of previously unknown structure predicted from low sequence homology between TAAs. These elements are typically up to 40 amino acids long and are not domains, but rather modular structural elements that may be duplicated or omitted through evolution, creating molecular diversity among TAAs. Conclusions/Significance The modular nature of BpaA, as demonstrated by its head domain crystal structure, and of TAAs in general provides insights into evolution of pathogen-host adhesion and may provide an avenue for diagnostics. PMID:20862217

  7. Cocrystal structure of the ICAP1 PTB domain in complex with a KRIT1 peptide

    PubMed Central

    Liu, Weizhi; Boggon, Titus J.

    2013-01-01

    Integrin cytoplasmic domain-associated protein-1 (ICAP1) is a suppressor of integrin activation and directly binds to the cytoplasmic tail of β1 integrins; its binding suppresses integrin activation by competition with talin. Krev/Rap1 interaction trapped-1 (KRIT1) releases ICAP1 suppression of integrin activation by sequestering ICAP1 away from integrin cytoplasmic tails. Here, the cocrystal structure of the PTB domain of ICAP1 in complex with a 29-­amino-acid fragment (residues 170–198) of KRIT1 is presented to 1.7 Å resolution [the resolution at which 〈I/σ(I)〉 = 2.9 was 1.83 Å]. In previous studies, the structure of ICAP1 with integrin β1 was determined to 3.0 Å resolution and that of ICAP1 with the N-terminal portion of KRIT1 (residues 1–­198) was determined to 2.54 Å resolution; therefore, this study provides the highest resolution structure yet of ICAP1 and allows further detailed analysis of the interaction of ICAP1 with its minimal binding region in KRIT1. PMID:23695561

  8. DIPA-family coiled-coils bind conserved isoform-specific head domain of p120-catenin family: potential roles in hydrocephalus and heterotopia.

    PubMed

    Markham, Nicholas O; Doll, Caleb A; Dohn, Michael R; Miller, Rachel K; Yu, Huapeng; Coffey, Robert J; McCrea, Pierre D; Gamse, Joshua T; Reynolds, Albert B

    2014-09-01

    p120-catenin (p120) modulates adherens junction (AJ) dynamics by controlling the stability of classical cadherins. Among all p120 isoforms, p120-3A and p120-1A are the most prevalent. Both stabilize cadherins, but p120-3A is preferred in epithelia, whereas p120-1A takes precedence in neurons, fibroblasts, and macrophages. During epithelial-to-mesenchymal transition, E- to N-cadherin switching coincides with p120-3A to -1A alternative splicing. These isoforms differ by a 101-amino acid "head domain" comprising the p120-1A N-terminus. Although its exact role is unknown, the head domain likely mediates developmental and cancer-associated events linked to p120-1A expression (e.g., motility, invasion, metastasis). Here we identified delta-interacting protein A (DIPA) as the first head domain-specific binding partner and candidate mediator of isoform 1A activity. DIPA colocalizes with AJs in a p120-1A- but not 3A-dependent manner. Moreover, all DIPA family members (Ccdc85a, Ccdc85b/DIPA, and Ccdc85c) interact reciprocally with p120 family members (p120, δ-catenin, p0071, and ARVCF), suggesting significant functional overlap. During zebrafish neural tube development, both knockdown and overexpression of DIPA phenocopy N-cadherin mutations, an effect bearing functional ties to a reported mouse hydrocephalus phenotype associated with Ccdc85c. These studies identify a novel, highly conserved interaction between two protein families that may participate either individually or collectively in N-cadherin-mediated development. © 2014 Markham et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  9. Blocking neutrophil integrin activation prevents ischemia-reperfusion injury.

    PubMed

    Yago, Tadayuki; Petrich, Brian G; Zhang, Nan; Liu, Zhenghui; Shao, Bojing; Ginsberg, Mark H; McEver, Rodger P

    2015-07-27

    Neutrophil recruitment, mediated by β2 integrins, combats pyogenic infections but also plays a key role in ischemia-reperfusion injury and other inflammatory disorders. Talin induces allosteric rearrangements in integrins that increase affinity for ligands (activation). Talin also links integrins to actin and other proteins that enable formation of adhesions. Structural studies have identified a talin1 mutant (L325R) that perturbs activation without impairing talin's capacity to link integrins to actin and other proteins. Here, we found that mice engineered to express only talin1(L325R) in myeloid cells were protected from renal ischemia-reperfusion injury. Dissection of neutrophil function in vitro and in vivo revealed that talin1(L325R) neutrophils had markedly impaired chemokine-induced, β2 integrin-mediated arrest, spreading, and migration. Surprisingly, talin1(L325R) neutrophils exhibited normal selectin-induced, β2 integrin-mediated slow rolling, in sharp contrast to the defective slow rolling of neutrophils lacking talin1 or expressing a talin1 mutant (W359A) that blocks talin interaction with integrins. These studies reveal the importance of talin-mediated activation of integrins for renal ischemia-reperfusion injury. They further show that neutrophil arrest requires talin recruitment to and activation of integrins. However, although neutrophil slow rolling requires talin recruitment to integrins, talin-mediated integrin activation is dispensable. © 2015 Yago et al.

  10. Magnetic domain wall gratings for magnetization reversal tuning and confined dynamic mode localization.

    PubMed

    Trützschler, Julia; Sentosun, Kadir; Mozooni, Babak; Mattheis, Roland; McCord, Jeffrey

    2016-08-04

    High density magnetic domain wall gratings are imprinted in ferromagnetic-antiferromagnetic thin films by local ion irradiation by which alternating head-to-tail-to-head-to-tail and head-to-head-to-tail-to-tail spatially overlapping domain wall networks are formed. Unique magnetic domain processes result from the interaction of anchored domain walls. Non-linear magnetization response is introduced by the laterally distributed magnetic anisotropy phases. The locally varying magnetic charge distribution gives rise to localized and guided magnetization spin-wave modes directly constrained by the narrow domain wall cores. The exchange coupled multiphase material structure leads to unprecedented static and locally modified dynamic magnetic material properties.

  11. Magnetic domain wall gratings for magnetization reversal tuning and confined dynamic mode localization

    NASA Astrophysics Data System (ADS)

    Trützschler, Julia; Sentosun, Kadir; Mozooni, Babak; Mattheis, Roland; McCord, Jeffrey

    2016-08-01

    High density magnetic domain wall gratings are imprinted in ferromagnetic-antiferromagnetic thin films by local ion irradiation by which alternating head-to-tail-to-head-to-tail and head-to-head-to-tail-to-tail spatially overlapping domain wall networks are formed. Unique magnetic domain processes result from the interaction of anchored domain walls. Non-linear magnetization response is introduced by the laterally distributed magnetic anisotropy phases. The locally varying magnetic charge distribution gives rise to localized and guided magnetization spin-wave modes directly constrained by the narrow domain wall cores. The exchange coupled multiphase material structure leads to unprecedented static and locally modified dynamic magnetic material properties.

  12. Structure of the Head of the Bartonella Adhesin BadA

    PubMed Central

    Szczesny, Pawel; Linke, Dirk; Ursinus, Astrid; Bär, Kerstin; Schwarz, Heinz; Riess, Tanja M.; Kempf, Volkhard A. J.; Lupas, Andrei N.; Martin, Jörg; Zeth, Kornelius

    2008-01-01

    Trimeric autotransporter adhesins (TAAs) are a major class of proteins by which pathogenic proteobacteria adhere to their hosts. Prominent examples include Yersinia YadA, Haemophilus Hia and Hsf, Moraxella UspA1 and A2, and Neisseria NadA. TAAs also occur in symbiotic and environmental species and presumably represent a general solution to the problem of adhesion in proteobacteria. The general structure of TAAs follows a head-stalk-anchor architecture, where the heads are the primary mediators of attachment and autoagglutination. In the major adhesin of Bartonella henselae, BadA, the head consists of three domains, the N-terminal of which shows strong sequence similarity to the head of Yersinia YadA. The two other domains were not recognizably similar to any protein of known structure. We therefore determined their crystal structure to a resolution of 1.1 Å. Both domains are β-prisms, the N-terminal one formed by interleaved, five-stranded β-meanders parallel to the trimer axis and the C-terminal one by five-stranded β-meanders orthogonal to the axis. Despite the absence of statistically significant sequence similarity, the two domains are structurally similar to domains from Haemophilus Hia, albeit in permuted order. Thus, the BadA head appears to be a chimera of domains seen in two other TAAs, YadA and Hia, highlighting the combinatorial evolutionary strategy taken by pathogens. PMID:18688279

  13. Blocking neutrophil integrin activation prevents ischemia–reperfusion injury

    PubMed Central

    Yago, Tadayuki; Petrich, Brian G.; Zhang, Nan; Liu, Zhenghui; Shao, Bojing; Ginsberg, Mark H.

    2015-01-01

    Neutrophil recruitment, mediated by β2 integrins, combats pyogenic infections but also plays a key role in ischemia–reperfusion injury and other inflammatory disorders. Talin induces allosteric rearrangements in integrins that increase affinity for ligands (activation). Talin also links integrins to actin and other proteins that enable formation of adhesions. Structural studies have identified a talin1 mutant (L325R) that perturbs activation without impairing talin’s capacity to link integrins to actin and other proteins. Here, we found that mice engineered to express only talin1(L325R) in myeloid cells were protected from renal ischemia–reperfusion injury. Dissection of neutrophil function in vitro and in vivo revealed that talin1(L325R) neutrophils had markedly impaired chemokine-induced, β2 integrin–mediated arrest, spreading, and migration. Surprisingly, talin1(L325R) neutrophils exhibited normal selectin-induced, β2 integrin–mediated slow rolling, in sharp contrast to the defective slow rolling of neutrophils lacking talin1 or expressing a talin1 mutant (W359A) that blocks talin interaction with integrins. These studies reveal the importance of talin-mediated activation of integrins for renal ischemia–reperfusion injury. They further show that neutrophil arrest requires talin recruitment to and activation of integrins. However, although neutrophil slow rolling requires talin recruitment to integrins, talin-mediated integrin activation is dispensable. PMID:26169939

  14. Excitations of interface pinned domain walls in constrained geometries

    NASA Astrophysics Data System (ADS)

    Martins, S. M. S. B.; Oliveira, L. L.; Rebouças, G. O. G.; Dantas, Ana L.; Carriço, A. S.

    2018-05-01

    We report a theoretical investigation of the equilibrium pattern and the spectra of head-to-head and Neel domain walls of flat Fe and Py stripes, exchange coupled with a vicinal antiferromagnetic substrate. We show that the domain wall excitation spectrum is tunable by the strength of the interface field. Furthermore, strong interface coupling favors localized wall excitations.

  15. Head and neck cancer-specific quality of life: instrument validation.

    PubMed

    Terrell, J E; Nanavati, K A; Esclamado, R M; Bishop, J K; Bradford, C R; Wolf, G T

    1997-10-01

    The disfigurement and dysfunction associated with head and neck cancer affect emotional well-being and some of the most basic functions of life. Most cancer-specific quality-of-life assessments give a single composite score for head and neck cancer-related quality of life. To develop and evaluate an improved multidimensional instrument to assess head and neck cancer-related functional status and well-being. The item selection process included literature review, interviews with health care workers, and patient surveys. A survey with 37 disease-specific questions and the SF-12 survey were administered to 253 patients in 3 large medical centers. Factor analysis was performed to identify disease-specific domains. Domain scores were calculated as the standardized score of the component items. These domains were assessed for construct validity based on clinical hypotheses and test-retest reliability. Four relevant domains were identified: Eating (6 items), Communication (4 items), Pain (4 items), and Emotion (6 items). Each had an internal consistency (Cronbach alpha value) of greater than 0.80. Construct validity was demonstrated by moderate correlations with the SF-12 Physical and Mental component scores (r=0.43-0.60). Test-retest reliability for each domain demonstrated strong reliability between the 2 time points. Correlations were strong for each individual question, ranging from 0.53 to 0.93. Construct validity testing demonstrated that the direction of differences for each domain were as hypothesized. The Head and Neck Quality of Life questionnaire is a promising multidimensional tool with which to assess head and neck cancer-specific quality of life.

  16. Quantal concept of T-cell activation: adhesion domains as immunological synapses

    NASA Astrophysics Data System (ADS)

    Sackmann, Erich

    2011-06-01

    Adhesion micro-domains (ADs) formed during encounters of lymphocytes with antigen-presenting cells (APC) mediate the genetic expression of quanta of cytokines interleukin-2 (IL-2). The IL-2-induced activation of IL-2 receptors promotes the stepwise progression of the T-cells through the cell cycle, hence their name, immunological synapses. The ADs form short-lived reaction centres controlling the recruitment of activators of the biochemical pathway (the kinases Lck and ZAP) while preventing the access of inhibitors (phosphatase CD45) through steric repulsion forces. CD45 acts as the generator of adhesion domains and, through its role as a spacer protein, also as the promoter of the reaction. In a second phase of T-cell-APC encounters, long-lived global reaction spaces (called supramolecular activation complexes (SMAC)) form by talin-mediated binding of the T-cell integrin (LFA-1) to the counter-receptor ICAM-1, resulting in the formation of ring-like tight adhesion zones (peripheral SMAC). The ADs move to the centre of the intercellular adhesion zone forming the central SMAC, which serve in the recycling of the AD. We propose that cell stimulation is triggered by integrating the effect evoked by the short-lived adhesion domains. Similar global reaction platforms are formed by killer cells to destruct APC. We present a testable mechanical model showing that global reaction spaces (SMAC or dome-like contacts between cytotoxic cells and APC) form by self-organization through delayed activation of the integrin-binding affinity and stabilization of the adhesion zones by F-actin recruitment. The mechanical stability and the polarization of the adhering T-cells are mediated by microtubule-actin cross-talk.

  17. Head Start Impact Study. Final Report

    ERIC Educational Resources Information Center

    Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Shapiro, Gary; Broene, Pam; Jenkins, Frank; Fletcher, Philip; Quinn, Liz; Friedman, Janet; Ciarico, Janet; Rohacek, Monica; Adams, Gina; Spier, Elizabeth

    2010-01-01

    This report addresses the following four questions by reporting on the impacts of Head Start on children and families during the children's preschool, kindergarten, and 1st grade years: (1) What difference does Head Start make to key outcomes of development and learning (and in particular, the multiple domains of school readiness) for low-income…

  18. The Integrin Receptor in Biologically Relevant Bilayers: Insights from Molecular Dynamics Simulations.

    PubMed

    Kalli, Antreas C; Rog, Tomasz; Vattulainen, Ilpo; Campbell, Iain D; Sansom, Mark S P

    2017-08-01

    Integrins are heterodimeric (αβ) cell surface receptors that are potential therapeutic targets for a number of diseases. Despite the existence of structural data for all parts of integrins, the structure of the complete integrin receptor is still not available. We have used available structural data to construct a model of the complete integrin receptor in complex with talin F2-F3 domain. It has been shown that the interactions of integrins with their lipid environment are crucial for their function but details of the integrin/lipid interactions remain elusive. In this study an integrin/talin complex was inserted in biologically relevant bilayers that resemble the cell plasma membrane containing zwitterionic and charged phospholipids, cholesterol and sphingolipids to study the dynamics of the integrin receptor and its effect on bilayer structure and dynamics. The results of this study demonstrate the dynamic nature of the integrin receptor and suggest that the presence of the integrin receptor alters the lipid organization between the two leaflets of the bilayer. In particular, our results suggest elevated density of cholesterol and of phosphatidylserine lipids around the integrin/talin complex and a slowing down of lipids in an annulus of ~30 Å around the protein due to interactions between the lipids and the integrin/talin F2-F3 complex. This may in part regulate the interactions of integrins with other related proteins or integrin clustering thus facilitating signal transduction across cell membranes.

  19. D120 and K152 within the PH Domain of T Cell Adapter SKAP55 Regulate Plasma Membrane Targeting of SKAP55 and LFA-1 Affinity Modulation in Human T Lymphocytes

    PubMed Central

    Witte, Amelie; Meineke, Bernhard; Sticht, Jana; Philipsen, Lars; Kuropka, Benno; Müller, Andreas J.; Freund, Christian

    2017-01-01

    ABSTRACT The β2-integrin lymphocyte function-associated antigen 1 (LFA-1) is needed for the T cell receptor (TCR)-induced activation of LFA-1 to promote T cell adhesion and interaction with antigen-presenting cells (APCs). LFA-1-mediated cell-cell interactions are critical for proper T cell differentiation and proliferation. The Src kinase-associated phosphoprotein of 55 kDa (SKAP55) is a key regulator of TCR-mediated LFA-1 signaling (inside-out/outside-in signaling). To gain an understanding of how SKAP55 controls TCR-mediated LFA-1 activation, we assessed the functional role of its pleckstrin homology (PH) domain. We identified two critical amino acid residues within the PH domain of SKAP55, aspartic acid 120 (D120) and lysine 152 (K152). D120 facilitates the retention of SKAP55 in the cytoplasm of nonstimulated T cells, while K152 promotes SKAP55 membrane recruitment via actin binding upon TCR triggering. Importantly, the K152-dependent interaction of the PH domain with actin promotes the binding of talin to LFA-1, thus facilitating LFA-1 activation. These data suggest that K152 and D120 within the PH domain of SKAP55 regulate plasma membrane targeting and TCR-mediated activation of LFA-1. PMID:28052935

  20. Mutation of the myosin converter domain alters cross-bridge elasticity

    PubMed Central

    Köhler, Jan; Winkler, Gerhard; Schulte, Imke; Scholz, Tim; McKenna, William; Brenner, Bernhard; Kraft, Theresia

    2002-01-01

    Elastic distortion of a structural element of the actomyosin complex is fundamental to the ability of myosin to generate motile forces. An elastic element allows strain to develop within the actomyosin complex (cross-bridge) before movement. Relief of this strain then drives filament sliding, or more generally, movement of a cargo. Even with the known crystal structure of the myosin head, however, the structural element of the actomyosin complex in which elastic distortion occurs remained unclear. To assign functional relevance to various structural elements of the myosin head, e.g., to identify the elastic element within the cross-bridge, we studied mechanical properties of muscle fibers from patients with familial hypertrophic cardiomyopathy with point mutations in the head domain of the β-myosin heavy chain. We found that the Arg-719 → Trp (Arg719Trp) mutation, which is located in the converter domain of the myosin head fragment, causes an increase in force generation and fiber stiffness under isometric conditions by 48–59%. Under rigor and relaxing conditions, fiber stiffness was 45–47% higher than in control fibers. Yet, kinetics of active cross-bridge cycling were unchanged. These findings, especially the increase in fiber stiffness under rigor conditions, indicate that cross-bridges with the Arg719Trp mutation are more resistant to elastic distortion. The data presented here strongly suggest that the converter domain that forms the junction between the catalytic and the light-chain-binding domain of the myosin head is not only essential for elastic distortion of the cross-bridge, but that the main elastic distortion may even occur within the converter domain itself. PMID:11904418

  1. 3-D segmentation of retinal blood vessels in spectral-domain OCT volumes of the optic nerve head

    NASA Astrophysics Data System (ADS)

    Lee, Kyungmoo; Abràmoff, Michael D.; Niemeijer, Meindert; Garvin, Mona K.; Sonka, Milan

    2010-03-01

    Segmentation of retinal blood vessels can provide important information for detecting and tracking retinal vascular diseases including diabetic retinopathy, arterial hypertension, arteriosclerosis and retinopathy of prematurity (ROP). Many studies on 2-D segmentation of retinal blood vessels from a variety of medical images have been performed. However, 3-D segmentation of retinal blood vessels from spectral-domain optical coherence tomography (OCT) volumes, which is capable of providing geometrically accurate vessel models, to the best of our knowledge, has not been previously studied. The purpose of this study is to develop and evaluate a method that can automatically detect 3-D retinal blood vessels from spectral-domain OCT scans centered on the optic nerve head (ONH). The proposed method utilized a fast multiscale 3-D graph search to segment retinal surfaces as well as a triangular mesh-based 3-D graph search to detect retinal blood vessels. An experiment on 30 ONH-centered OCT scans (15 right eye scans and 15 left eye scans) from 15 subjects was performed, and the mean unsigned error in 3-D of the computer segmentations compared with the independent standard obtained from a retinal specialist was 3.4 +/- 2.5 voxels (0.10 +/- 0.07 mm).

  2. Direct observation of charged domain walls in hybrid improper ferroelectric (Ca,Sr)3Ti2O7

    NASA Astrophysics Data System (ADS)

    Kurushima, Kousuke; Yoshimoto, Wataru; Ishii, Yui; Cheong, Sang-Wook; Mori, Shigeo

    2017-10-01

    We investigated ferroelectric (FE) domain wall structures including “charged domain walls” of hybrid improper FE (Ca,Sr)3Ti2O7 at the subatomic resolution by dark-field transmission electron microscopy (TEM) and high-resolution state-of-the-art aberration-corrected high-angle annular-dark-field (HAADF) scanning transmission electron microscopy (STEM). Dark-field TEM and high-resolution HAADF-STEM images obtained in the FE phase of single crystals of Ca2.46Sr0.54Ti2O7 revealed the formation of abundant charged domain walls with the head-to-head and tail-to-tail configurations in the FE domain structure, in addition to the FE 180° domain structure. The charged domain walls with the head-to-head and tail-to-tail FE polarizations exist stably and can be characterized as the unique double arc-type displacement of Ca/Sr ions in a unit cell without charge accumulation.

  3. Linking the Heart and the Head: Humanism and Professionalism in Medical Education and Practice.

    PubMed

    Montgomery, Lynda; Loue, Sana; Stange, Kurt C

    2017-05-01

    This paper articulates a practical interpretive framework for understanding humanism in medicine through the lens of how it is taught and learned. Beginning with a search for key tensions and relevant insights in the literature on humanism in health professions education, we synthesized a conceptual model designed to foster reflection and action to realize humanistic principles in medical education and practice. The resulting model centers on the interaction between the heart and the head. The heart represents the emotive domains of empathy, compassion, and connectedness. The head represents the cognitive domains of knowledge, attitudes, and beliefs. The cognitive domains often are associated with professionalism, and the emotive domains with humanism, but it is the connection between the two that is vital to humanistic education and practice. The connection between the heart and the head is nurtured by critical reflection and conscious awareness. Four provinces of experience nurture humanism: (1) personal reflection, (2) action, (3) system support, and (4) collective reflection. These domains represent potential levers for developing humanism. Critical reflection and conscious awareness between the heart and head through personal reflection, individual and collective behavior, and supportive systems has potential to foster humanistic development toward healing and health.

  4. Resonant tunneling across a ferroelectric domain wall

    NASA Astrophysics Data System (ADS)

    Li, M.; Tao, L. L.; Velev, J. P.; Tsymbal, E. Y.

    2018-04-01

    Motivated by recent experimental observations, we explore electron transport properties of a ferroelectric tunnel junction (FTJ) with an embedded head-to-head ferroelectric domain wall, using first-principles density-functional theory calculations. We consider a FTJ with L a0.5S r0.5Mn O3 electrodes separated by a BaTi O3 barrier layer and show that an in-plane charged domain wall in the ferroelectric BaTi O3 can be induced by polar interfaces. The resulting V -shaped electrostatic potential profile across the BaTi O3 layer creates a quantum well and leads to the formation of a two-dimensional electron gas, which stabilizes the domain wall. The confined electronic states in the barrier are responsible for resonant tunneling as is evident from our quantum-transport calculations. We find that the resonant tunneling is an orbital selective process, which leads to sharp spikes in the momentum- and energy-resolved transmission spectra. Our results indicate that domain walls embedded in FTJs can be used to control the electron transport.

  5. The Rickettsia Surface Cell Antigen 4 Applies Mimicry to Bind to and Activate Vinculin*

    PubMed Central

    Park, HaJeung; Lee, Jun Hyuck; Gouin, Edith; Cossart, Pascale; Izard, Tina

    2011-01-01

    Pathogenic Rickettsia species cause high morbidity and mortality, especially R. prowazekii, the causative agent of typhus. Like many intracellular pathogens, Rickettsia exploit the cytoskeleton to enter and spread within the host cell. Here we report that the cell surface antigen sca4 of Rickettsia co-localizes with vinculin in cells at sites of focal adhesions in sca4-transfected cells and that sca4 binds to and activates vinculin through two vinculin binding sites (VBSs) that are conserved across all Rickettsia. Remarkably, this occurs through molecular mimicry of the vinculin-talin interaction that is also seen with the IpaA invasin of the intracellular pathogen Shigella, where binding of these VBSs to the vinculin seven-helix bundle head domain (Vh1) displaces intramolecular interactions with the vinculin tail domain that normally clamp vinculin in an inactive state. Finally, the vinculin·sca4-VBS crystal structures reveal that vinculin adopts a new conformation when bound to the C-terminal VBS of sca4. Collectively, our data define the mechanism by which sca4 activates vinculin and interacts with the actin cytoskeleton, and they suggest important roles for vinculin in Rickettsia pathogenesis. PMID:21841197

  6. Core competencies to prevent and control chronic diseases of Tambol Health Centers' head in Thailand.

    PubMed

    Leerapan, Prasit; Kengganpanich, Tharadol; Sompopcharoen, Malinee

    2012-06-01

    To assess the core competencies to prevent and control chronic diseases of the head of Tambol Health Centers (THC) in Thailand. This cross-sectional survey research was carried out with 2,049 heads of THC from the total population of 9,985. The samples were selected randomly from all provinces of every region. The data were collected through mail questionnaires and the reliability values of the three competency domains questionnaire were found to be between 0.75-0.93. Data analysis was done by computing frequency, percentage, arithmetic mean, Independent's t-test and One-way ANOVA. The total core competency values of prevention and control of diabetes and hypertension of the THC heads were found at the high and moderate level (3.0% and 78.7%) respectively The similar finding was found in the competency domains in regard to "personal attribution", "intellectual capacity" while 8.0 percent and 46.2 percent of the respondents had the high and moderate level of "work skill" domain respectively. In addition, the differences of competency domains were found in accordance with the regions where the THC located, ability to develop a plan for disease prevention and readiness for changing behaviors of the risk groups. But the personal attributions with regard to gender age, family's economic status, and the location of the THC were not found to affect every competency domain. Except for the intellectual capacity domain found that the male THC heads had the higher level than the females and work skill domain of those THC heads working in the municipal areas had the higher level than those who worked outside the municipal areas. Core competencies of the heads of THC in chronic disease prevention and control were found at the "somewhat good" level except for the work skill domain which needed to be developed. Thus, the Ministry of Public Health should establish a specific policy and strategy on human resource development by using core competencies on chronic disease prevention

  7. Spin-wave-driven high-speed domain-wall motions in soft magnetic nanotubes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Jaehak; Yoo, Myoung-Woo; Kim, Sang-Koog, E-mail: sangkoog@snu.ac.kr

    We report on a micromagnetic simulation study of interactions between propagating spin waves and a head-to-head domain wall in geometrically confined magnetic nanotubes. We found that incident spin waves of specific frequencies can lead to sufficiently high-speed (on the order of a few hundreds of m/s or higher) domain-wall motions in the same direction as that of the incident spin-waves. The domain-wall motions and their speed vary remarkably with the frequency and the amplitude of the incident spin-waves. High-speed domain-wall motions originate from the transfer torque of spin waves' linear momentum to the domain wall, through the partial or completemore » reflection of the incident spin waves from the domain wall. This work provides a fundamental understanding of the interaction of the spin waves with a domain wall in the magnetic nanotubes as well as a route to all-magnetic control of domain-wall motions in the magnetic nanoelements.« less

  8. The Pleckstrin Homology Domain of Phospholipase Cβ Transmits Enzymatic Activation through Modulation of Membrane - Domain Orientation§

    PubMed Central

    Drin, Guillaume; Douguet, Dominique; Scarlata, Suzanne

    2008-01-01

    Phospholipase C-beta (PLCβ) enzymes are activated by Gαq and Gβγ subunits and catalyze the hydrolysis of the minor membrane lipid phosphatidylinositol 4,5 bisphosphate (PI(4,5)P2). Activation of PLCβ2 by Gβγ subunits has been shown to be conferred through its N-terminal pleckstrin homology (PH) domain although the underlying mechanism is unclear. Also unclear are observations that the extent of Gβγ activation differs on different membrane surfaces. In this study, we have identified a unique region of the PH domain of PLCβ2 domain (residues 71-88) which, when added to the enzyme as a peptide, causes enzyme activation similar to Gβγ subunits. This PH domain segment interacts strongly with membranes composed of lipid mixtures but not those containing lipids with electrically neutral zwitterionic head groups. Moreso, addition of this segment perturbs interaction of the catalytic domain, but not the PH domain, with membrane surfaces. We monitored the orientation of the PH and catalytic domains of PLC by intermolecular fluorescence resonance energy transfer (FRET) using the Gβγ activatable mutant, PLCβ2/δ1(C193S). We find an increase in FRET with binding to membranes with mixed lipids but not to those containing only lipids with electrically neutral head groups. These results suggest that enzymatic activation can be conferred through optimal association of the PHβ71-88 region to specific membrane surfaces. These studies allow us to understand the basis of variations of Gβγ activation on different membrane surfaces. PMID:16669615

  9. Coordinated Mechanosensitivity of Membrane Rafts and Focal Adhesions

    PubMed Central

    Fuentes, Daniela E.; Butler, Peter J.

    2013-01-01

    Endothelial cells sense mechanical forces of blood flow through mechanisms that involve focal adhesions (FAs). The mechanosensitive pathways that originate from FA-associated integrin activation may involve membrane rafts, small cholesterol- and sphigolipid-rich domains that are either immobilized, by virtue of their attachment to the cytoskeleton, or highly mobile in the plane of the plasma membrane. In this study, we fluorescently labeled non-mobile and mobile populations of GM1, a ganglioside associated with lipid rafts, and transfected cells with the red fluorescent protein-(RFP-) talin, an indicator of integrin activation at FAs, in order to determine the kinetics and sequential order of raft and talin mechanosensitivity. Cells were imaged under confocal microscopy during mechanical manipulation of a FA induced by a fibronectin (FN)-functionalized nanoelectrode with feedback control of position. First, FA deformation led to long range deformation of immobile rafts followed by active recoil of a subpopulation of displaced rafts. Second, initial adhesion between the FN-probe and the cell induced rapid accumulation of GM1 at the probe site with a time constant of 1.7 s. Talin accumulated approximately 20 s later with a time constant of 0.6 s. Third, a 1 μm deformation of the FA lead to immediate (0.3 s) increase in GM1 fluorescence and a later (6 s) increase in talin. Fourth, long term deformation of FAs led to continual GM1 accumulation at the probe site that was reversed upon removal of the deformation. These results demonstrate that rafts are directly mechanosensitive and that raft mobility may enable the earliest events related to FA mechanosensing and reinforcement upon force application. PMID:23487555

  10. Structural Basis for Toughness and Flexibility in the C-terminal Passenger Domain of an Acinetobacter Trimeric Autotransporter Adhesin*

    PubMed Central

    Koiwai, Kotaro; Hartmann, Marcus D.; Linke, Dirk; Lupas, Andrei N.; Hori, Katsutoshi

    2016-01-01

    Trimeric autotransporter adhesins (TAAs) on the cell surface of Gram-negative pathogens mediate bacterial adhesion to host cells and extracellular matrix proteins. However, AtaA, a TAA in the nonpathogenic Acinetobacter sp. strain Tol 5, shows nonspecific high adhesiveness to abiotic material surfaces as well as to biotic surfaces. It consists of a passenger domain secreted by the C-terminal transmembrane anchor domain (TM), and the passenger domain contains an N-terminal head, N-terminal stalk, C-terminal head (Chead), and C-terminal stalk (Cstalk). The Chead-Cstalk-TM fragment, which is conserved in many Acinetobacter TAAs, has by itself the head-stalk-anchor architecture of a complete TAA. Here, we show the crystal structure of the Chead-Cstalk fragment, AtaA_C-terminal passenger domain (CPSD), providing the first view of several conserved TAA domains. The YadA-like head (Ylhead) of the fragment is capped by a unique structure (headCap), composed of three β-hairpins and a connector motif; it also contains a head insert motif (HIM1) before its last inner β-strand. The headCap, Ylhead, and HIM1 integrally form a stable Chead structure. Some of the major domains of the CPSD fragment are inherently flexible and provide bending sites for the fiber between segments whose toughness is ensured by topological chain exchange and hydrophobic core formation inside the trimer. Thus, although adherence assays using in-frame deletion mutants revealed that the characteristic adhesive sites of AtaA reside in its N-terminal part, the flexibility and toughness of the CPSD part provide the resilience that enables the adhesive properties of the full-length fiber across a wide range of conditions. PMID:26698633

  11. Superimposition, symbology, visual attention, and the head-up display

    NASA Technical Reports Server (NTRS)

    Martin-Emerson, R.; Wickens, C. D.

    1997-01-01

    In two experiments we examined a number of related factors postulated to influence head-up display (HUD) performance. We addressed the benefit of reduced scanning and the cost of increasing the number of elements in the visual field by comparing a superimposed HUD with an identical display in a head-down position in varying visibility conditions. We explored the extent to which the characteristics of HUD symbology support a division of attention by contrasting conformal symbology (which links elements of the display image to elements of the far domain) with traditional instrument landing system (ILS) symbology. Together the two experiments provide strong evidence that minimizing scanning between flight instruments and the far domain contributes substantially to the observed HUD performance advantage. Experiment 1 provides little evidence for a performance cost attributable to visual clutter. In Experiment 2 the pattern of differences in lateral tracking error between conformal and traditional ILS symbology supports the hypothesis that, to the extent that the symbology forms an object with the far domain, attention may be divided between the superimposed image and its counterpart in the far domain.

  12. Molecular mechanics of 30S subunit head rotation.

    PubMed

    Mohan, Srividya; Donohue, John Paul; Noller, Harry F

    2014-09-16

    During ribosomal translocation, a process central to the elongation phase of protein synthesis, movement of mRNA and tRNAs requires large-scale rotation of the head domain of the small (30S) subunit of the ribosome. It has generally been accepted that the head rotates by pivoting around the neck helix (h28) of 16S rRNA, its sole covalent connection to the body domain. Surprisingly, we observe that the calculated axis of rotation does not coincide with the neck. Instead, comparative structure analysis across 55 ribosome structures shows that 30S head movement results from flexing at two hinge points lying within conserved elements of 16S rRNA. Hinge 1, although located within the neck, moves by straightening of the kinked helix h28 at the point of contact with the mRNA. Hinge 2 lies within a three-way helix junction that extends to the body through a second, noncovalent connection; its movement results from flexing between helices h34 and h35 in a plane orthogonal to the movement of hinge 1. Concerted movement at these two hinges accounts for the observed magnitudes of head rotation. Our findings also explain the mode of action of spectinomycin, an antibiotic that blocks translocation by binding to hinge 2.

  13. Molecular mechanics of 30S subunit head rotation

    PubMed Central

    Mohan, Srividya; Donohue, John Paul; Noller, Harry F.

    2014-01-01

    During ribosomal translocation, a process central to the elongation phase of protein synthesis, movement of mRNA and tRNAs requires large-scale rotation of the head domain of the small (30S) subunit of the ribosome. It has generally been accepted that the head rotates by pivoting around the neck helix (h28) of 16S rRNA, its sole covalent connection to the body domain. Surprisingly, we observe that the calculated axis of rotation does not coincide with the neck. Instead, comparative structure analysis across 55 ribosome structures shows that 30S head movement results from flexing at two hinge points lying within conserved elements of 16S rRNA. Hinge 1, although located within the neck, moves by straightening of the kinked helix h28 at the point of contact with the mRNA. Hinge 2 lies within a three-way helix junction that extends to the body through a second, noncovalent connection; its movement results from flexing between helices h34 and h35 in a plane orthogonal to the movement of hinge 1. Concerted movement at these two hinges accounts for the observed magnitudes of head rotation. Our findings also explain the mode of action of spectinomycin, an antibiotic that blocks translocation by binding to hinge 2. PMID:25187561

  14. Head-up tilt and hyperventilation produce similar changes in cerebral oxygenation and blood volume: an observational comparison study using frequency-domain near-infrared spectroscopy

    PubMed Central

    Mantulin, William W.; Alexander, Brenton S.; Cerussi, Albert E.; Tromberg, Bruce J.; Yu, Zhaoxia; Laning, Kathleen; Kain, Zeev N.; Cannesson, Maxime; Gelb, Adrian W.

    2012-01-01

    Purpose During anesthesia, maneuvers which cause the least disturbance of cerebral oxygenation with the greatest decrease in intracranial pressure would be most beneficial to patients with intracranial hypertension. Both head-up tilt (HUT) and hyperventilation are used to decrease brain bulk, and both may be associated with decreases in cerebral oxygenation. In this observational study, our null hypothesis was that the impact of HUT and hyperventilation on cerebral tissue oxygen saturation (SctO2) and cerebral blood volume (CBV) are comparable. Methods Surgical patients without neurological disease were anesthetized with propofol-remifentanil. Before the start of surgery, frequency-domain near-infrared spectroscopy was used to measure SctO2 and CBV at the supine position, at the 30° head-up and head-down positions, as well as during hypoventilation and hyperventilation. Results Thirty-three patients were studied. Both HUT and hyperventilation induced small decreases in SctO2 [3.5 (2.6)%; P <0.001 and 3.0 (1.8)%; P <0.001, respectively] and in CBV [0.05 (0.07) mL·100 g−1; P <0.001 and 0.06 (0.05) mL·100 g−1; P <0.001, respectively]. There were no differences between HUT to 30° and hyperventilation to an end-tidal carbon dioxide (ETCO2) of 25 mmHg (from 45 mmHg) in both SctO2 (P = 0.3) and CBV (P = 0.4). Discussion The small but statistically significant decreases in both SctO2 and CBV caused by HUT and hyperventilation are comparable. There was no correlation between the decreases in SctO2 and CBV and the decreases in blood pressure and cardiac output during head-up and head-down tilts. However, the decreases in both SctO2 and CBV correlate with the decreases in ETCO2 during ventilation adjustment. PMID:22234820

  15. Head-up tilt and hyperventilation produce similar changes in cerebral oxygenation and blood volume: an observational comparison study using frequency-domain near-infrared spectroscopy.

    PubMed

    Meng, Lingzhong; Mantulin, William W; Alexander, Brenton S; Cerussi, Albert E; Tromberg, Bruce J; Yu, Zhaoxia; Laning, Kathleen; Kain, Zeev N; Cannesson, Maxime; Gelb, Adrian W

    2012-04-01

    During anesthesia, maneuvers which cause the least disturbance of cerebral oxygenation with the greatest decrease in intracranial pressure would be most beneficial to patients with intracranial hypertension. Both head-up tilt (HUT) and hyperventilation are used to decrease brain bulk, and both may be associated with decreases in cerebral oxygenation. In this observational study, our null hypothesis was that the impact of HUT and hyperventilation on cerebral tissue oxygen saturation (SctO2) and cerebral blood volume (CBV) are comparable. Surgical patients without neurological disease were anesthetized with propofol-remifentanil. Before the start of surgery, frequency-domain near-infrared spectroscopy was used to measure SctO2 and CBV at the supine position, at the 30° head-up and head-down positions, as well as during hypoventilation and hyperventilation. Thirty-three patients were studied. Both HUT and hyperventilation induced small decreases in SctO2 [3.5 (2.6)%; P < 0.001 and 3.0 (1.8)%; P < 0.001, respectively] and in CBV [0.05 (0.07) mL x 100 g(-1); P < 0.001 and 0.06 (0.05) mL x 100 g(-1); P < 0.001, respectively]. There were no differences between HUT to 30° and hyperventilation to an end-tidal carbon dioxide (ETCO2) of 25 mmHg (from 45 mmHg) in both SctO2 (P = 0.3) and CBV (P = 0.4). The small but statistically significant decreases in both SctO2 and CBV caused by HUT and hyperventilation are comparable. There was no correlation between the decreases in SctO2 and CBV and the decreases in blood pressure and cardiac output during head-up and head-down tilts. However, the decreases in both SctO2 and CBV correlate with the decreases in ETCO2 during ventilation adjustment.

  16. Evaluating Computer-Generated Domain-Oriented Vocabularies.

    ERIC Educational Resources Information Center

    Damerau, Fred J.

    1990-01-01

    Discusses methods for automatically compiling domain-oriented vocabularies in natural language systems and describes techniques for evaluating the quality of the resulting word lists. A study is described that used subject headings from Grolier's Encyclopedia and the United Press International newswire, and filters for removing high frequency…

  17. Single molecule FRET observation of kinesin-1’s head-tail interaction on microtubule

    PubMed Central

    Aoki, Takahiro; Tomishige, Michio; Ariga, Takayuki

    2013-01-01

    Kinesin-1 (conventional kinesin) is a molecular motor that transports various cargo such as endoplasmic reticulum and mitochondria in cells. Its two head domains walk along microtubule by hydrolyzing ATP, while the tail domains at the end of the long stalk bind to the cargo. When a kinesin is not carrying cargo, its motility and ATPase activity is inhibited by direct interactions between the tail and head. However, the mechanism of this tail regulation is not well understood. Here, we apply single molecule fluorescence resonance energy transfer (smFRET) to observe this interaction in stalk-truncated kinesin. We found that kinesin with two tails forms a folding conformation and dissociates from microtubules, whereas kinesin with one tail remains bound to the micro-tubule and is immobile even in the presence of ATP. We further investigated the head-tail interaction as well as head-head coordination on the microtubule at various nucleotide conditions. From these results, we propose a two-step inhibition model for kinesin motility. PMID:27493553

  18. The Effects of Head Start Health Services: Report of the Head Start Health Evaluation. Volume I and II.

    ERIC Educational Resources Information Center

    Fosburg, Linda B.; And Others

    In 1977, a longitudinal study was initiated to assess the effectiveness of health services provided by Head Start. The study provided for 10 domains: pediatric health examinations, health history recordings, dental evaluation, anthropometric assessment, diet and nutrition assessment, and hematology evaluations, as well as for developmental,…

  19. Force-activatable coating enables high-resolution cellular force imaging directly on regular cell culture surfaces.

    PubMed

    Sarkar, Anwesha; Zhao, Yuanchang; Wang, Yongliang; Wang, Xuefeng

    2018-06-25

    Integrin-transmitted cellular forces are crucial mechanical signals regulating a vast range of cell functions. Although various methods have been developed to visualize and quantify cellular forces at the cell-matrix interface, a method with high performance and low technical barrier is still in demand. Here we developed a force-activatable coating (FAC), which can be simply coated on regular cell culture apparatus' surfaces by physical adsorption, and turn these surfaces to force reporting platforms that enable cellular force mapping directly by fluorescence imaging. The FAC molecule consists of an adhesive domain for surface coating and a force-reporting domain which can be activated to fluoresce by integrin molecular tension. The tension threshold required for FAC activation is tunable in 10-60 piconewton (pN), allowing the selective imaging of cellular force contributed by integrin tension at different force levels. We tested the performance of two FACs with tension thresholds of 12 and 54 pN (nominal values), respectively, on both glass and polystyrene surfaces. Cellular forces were successfully mapped by fluorescence imaging on all the surfaces. FAC-coated surfaces also enable co-imaging of cellular forces and cell structures in both live cells and immunostained cells, therefore opening a new avenue for the study of the interplay of force and structure. We demonstrated the co-imaging of integrin tension and talin clustering in live cells, and concluded that talin clustering always occurs before the generation of integrin tension above 54 pN, reinforcing the notion that talin is an important adaptor protein for integrin tension transmission. Overall, FAC provides a highly convenient approach that is accessible to general biological laboratories for the study of cellular forces with high sensitivity and resolution, thus holding the potential to greatly boost the research of cell mechanobiology.

  20. Do the Effects of Head Start Vary by Parental Preacademic Stimulation?

    ERIC Educational Resources Information Center

    Miller, Elizabeth B.; Farkas, George; Vandell, Deborah Lowe; Duncan, Greg J.

    2014-01-01

    Data from the Head Start Impact Study (N = 3,185, age = 3-4 years) were used to determine whether 1 year of Head Start differentially benefited children from homes with high, middle, and low levels of parental preacademic stimulation on three academic outcome domains--early math, early literacy, and receptive vocabulary. Results from residualized…

  1. Structural mapping of the coiled-coil domain of a bacterial condensin and comparative analyses across all domains of life suggest conserved features of SMC proteins.

    PubMed

    Waldman, Vincent M; Stanage, Tyler H; Mims, Alexandra; Norden, Ian S; Oakley, Martha G

    2015-06-01

    The structural maintenance of chromosomes (SMC) proteins form the cores of multisubunit complexes that are required for the segregation and global organization of chromosomes in all domains of life. These proteins share a common domain structure in which N- and C- terminal regions pack against one another to form a globular ATPase domain. This "head" domain is connected to a central, globular, "hinge" or dimerization domain by a long, antiparallel coiled coil. To date, most efforts for structural characterization of SMC proteins have focused on the globular domains. Recently, however, we developed a method to map interstrand interactions in the 50-nm coiled-coil domain of MukB, the divergent SMC protein found in γ-proteobacteria. Here, we apply that technique to map the structure of the Bacillus subtilis SMC (BsSMC) coiled-coil domain. We find that, in contrast to the relatively complicated coiled-coil domain of MukB, the BsSMC domain is nearly continuous, with only two detectable coiled-coil interruptions. Near the middle of the domain is a break in coiled-coil structure in which there are three more residues on the C-terminal strand than on the N-terminal strand. Close to the head domain, there is a second break with a significantly longer insertion on the same strand. These results provide an experience base that allows an informed interpretation of the output of coiled-coil prediction algorithms for this family of proteins. A comparison of such predictions suggests that these coiled-coil deviations are highly conserved across SMC types in a wide variety of organisms, including humans. © 2015 Wiley Periodicals, Inc.

  2. Edge-closed laminated structures for thin-film heads

    NASA Astrophysics Data System (ADS)

    Herman, D. A.; Argyle, B. E.; Lee, H.-P.; Trouilloud, P. O.; Petek, B.

    1991-04-01

    Magnetic film laminations containing nonmagnetic spacers have been explored with the hope of eliminating domain walls to diminish Barkhausen instabilities. Such laminates have limitations however, which originate in their ``edge-curling walls'' (ECWs).1 We have developed a new structure, free of ECWs, in which flux closure at opposing edges occurs via edge-shorting material added to circulate the easy-axis flux of the flat layers. We show experimentally with Kerr-effect imaging that (1) this edge-closed laminated (ECL) structure can support an (ECW-free) ``easy-axis'' (EA) magnetic state under conditions as modeled recently by Slonczewski,2 and (2) that this EA state is quite robust in the face of imperfect structure fabrication. This is, if the imperfections are not too severe, the resultant states depart minimally from the pure EA state and conduct hard-axis-driven flux nearly as well. Flat-film ECL elements in diamond, stripe, and recording-head-yoke shapes, plus experimental heads with ECL top yokes, were fabricated. Our domain images verify some key predictions from Slonczewski's static equilibrium modeling; additional results taken in applied magnetic fields extend the micromagnetic understanding. The sketch shows a typical domain pattem for a yoke-shaped element. The most stable state in the open portion of the yoke is the single domain shown. This remanent pattern was stable in the face of (slowly varying) external fields up to the 150 Oe that could be applied. The pole tip region contained a few 180° walls as indicated. On close inspection, these walls were seen to end in vestigial, nontouching, closure domains as predicted by the model when only partial flux closure occurs via the edge shorting material. The wall spacing in the tip varied somewhat following saturation-demagnetization cycles. The dynamic stability of this EA state was investigated in the experimental heads having ECL top yokes. The pseudodynamic LAMOM technique3 was applied using ``write

  3. The Fusion Protein Specificity of the Parainfluenza Virus Hemagglutinin-Neuraminidase Protein Is Not Solely Defined by the Primary Structure of Its Stalk Domain

    PubMed Central

    Ito, Morihiro; Ohtsuka, Junpei; Hara, Kenichiro; Komada, Hiroshi; Nishio, Machiko; Nosaka, Tetsuya

    2015-01-01

    ABSTRACT Virus-specific interaction between the attachment protein (HN) and the fusion protein (F) is prerequisite for the induction of membrane fusion by parainfluenza viruses. This HN-F interaction presumably is mediated by particular amino acids in the HN stalk domain and those in the F head domain. We found in the present study, however, that a simian virus 41 (SV41) F-specific chimeric HPIV2 HN protein, SCA, whose cytoplasmic, transmembrane, and stalk domains were derived from the SV41 HN protein, could not induce cell-cell fusion of BHK-21 cells when coexpressed with an SV41 HN-specific chimeric PIV5 F protein, no. 36. Similarly, a headless form of the SV41 HN protein failed to induce fusion with chimera no. 36, whereas it was able to induce fusion with the SV41 F protein. Interestingly, replacement of 13 amino acids of the SCA head domain, which are located at or around the dimer interface of the head domain, with SV41 HN counterparts resulted in a chimeric HN protein, SCA-RII, which induced fusion with chimera no. 36 but not with the SV41 F protein. More interestingly, retroreplacement of 11 out of the 13 amino acids of SCA-RII with the SCA counterparts resulted in another chimeric HN protein, IM18, which induced fusion either with chimera no. 36 or with the SV41 F protein, similar to the SV41 HN protein. Thus, we conclude that the F protein specificity of the HN protein that is observed in the fusion event is not solely defined by the primary structure of the HN stalk domain. IMPORTANCE It is appreciated that the HN head domain initially conceals the HN stalk domain but exposes it after the head domain has bound to the receptors, which allows particular amino acids in the stalk domain to interact with the F protein and trigger it to induce fusion. However, other regulatory roles of the HN head domain in the fusion event have been ill defined. We have shown in the current study that removal of the head domain or amino acid substitutions in a particular

  4. Identification of globular mechanochemical heads of kinesin.

    PubMed

    Scholey, J M; Heuser, J; Yang, J T; Goldstein, L S

    1989-03-23

    Kinesin is a mechanoenzyme which uses energy liberated from ATP hydrolysis to transport particles towards the 'plus ends' of microtubules. The enzyme consists of two polypeptide heavy chains of relative molecular mass (Mr) approximately 110,000-140,000 (110K-140K) plus copurifying light chains; these polypeptides are arranged in a structure consisting of two globular heads attached to a fibrous stalk which terminates in a 'feathered' tail. Here we report that a function-disrupting monoclonal antikinesin, which binds to the 45K fragment of the kinesin heavy chain, recognizes an epitope located towards the N-terminal end of the heavy chain, and decorates the two globular heads lying at one end of the intact molecules (one antibody per head). The results show that the two heavy chains of native kinesin are arranged in parallel, and that the 45K fragments, which display nucleotide-sensitive interactions with microtubules, represent mechanochemical 'heads' located at the N-terminal regions of the heavy chains. Thus, it is likely that the kinesin heads are analogous to the subfragment-1 domains of myosin.

  5. Dynamic and kinematic strategies for head movement control

    NASA Technical Reports Server (NTRS)

    Peterson, B. W.; Choi, H.; Hain, T.; Keshner, E.; Peng, G. C.

    2001-01-01

    This paper describes our analysis of the complex head-neck system using a combination of experimental and modeling approaches. Dynamical analysis of head movements and EMG activation elicited by perturbation of trunk position has examined functional contributions of biomechanically and neurally generated forces in lumped systems with greatly simplified kinematics. This has revealed that visual and voluntary control of neck muscles and the dynamic and static vestibulocollic and cervicocollic reflexes preferentially govern head-neck system state in different frequency domains. It also documents redundant control, which allows the system to compensate for lesions and creates a potential for substantial variability within and between subjects. Kinematic studies have indicated the existence of reciprocal and co-contraction strategies for voluntary force generation, of a vestibulocollic strategy for stabilizing the head during body perturbations and of at least two strategies for voluntary head tracking. Each strategy appears to be executed by a specific muscle synergy that is presumably optimized to efficiently meet the demands of the task.

  6. Electron microscopic evidence for the myosin head lever arm mechanism in hydrated myosin filaments using the gas environmental chamber

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Minoda, Hiroki; CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012; Okabe, Tatsuhiro

    2011-02-25

    Research highlights: {yields} We succeeded in recording structural changes of hydrated myosin cross-bridges. {yields} We succeeded in position-marking the cross-bridges with site-directed antibodies. {yields} We recorded cross-bridge movement at different regions in individual cross-bridge. {yields} The movement was smallest at the cross-bridge-subfragment two boundary. {yields} The results provide evidence for the cross-bridge lever arm mechanism. -- Abstract: Muscle contraction results from an attachment-detachment cycle between the myosin heads extending from myosin filaments and the sites on actin filaments. The myosin head first attaches to actin together with the products of ATP hydrolysis, performs a power stroke associated with release ofmore » hydrolysis products, and detaches from actin upon binding with new ATP. The detached myosin head then hydrolyses ATP, and performs a recovery stroke to restore its initial position. The strokes have been suggested to result from rotation of the lever arm domain around the converter domain, while the catalytic domain remains rigid. To ascertain the validity of the lever arm hypothesis in muscle, we recorded ATP-induced movement at different regions within individual myosin heads in hydrated myosin filaments, using the gas environmental chamber attached to the electron microscope. The myosin head were position-marked with gold particles using three different site-directed antibodies. The amplitude of ATP-induced movement at the actin binding site in the catalytic domain was similar to that at the boundary between the catalytic and converter domains, but was definitely larger than that at the regulatory light chain in the lever arm domain. These results are consistent with the myosin head lever arm mechanism in muscle contraction if some assumptions are made.« less

  7. Do the Effects of Head Start Vary by Parental Preacademic Stimulation?

    PubMed Central

    Miller, Elizabeth B.; Farkas, George; Vandell, Deborah Lowe; Duncan, Greg J.

    2014-01-01

    Data from the Head Start Impact Study (N=3,185, age = 3–4 years) were used to determine whether one year of Head Start differentially benefited children from homes with high, middle, and low levels of parental preacademic stimulation on three academic outcome domains – early math, early literacy, and receptive vocabulary. Results from residualized growth models showed positive impacts of random assignment to Head Start on all three outcomes, and positive associations between parental preacademic stimulation and academic performance. Two moderated effects were also found. Head Start boosted early math skills the most for children receiving low parental preacademic stimulation. Effects of Head Start on early literacy skills were largest for children receiving moderate levels of parental preacademic stimulation. Implications for Head Start are discussed. PMID:24597729

  8. Essential role for SUN5 in anchoring sperm head to the tail

    PubMed Central

    Wang, Lina; Ouyang, Ying-Chun; Dong, Ming-Zhe; Liu, Chao; Zhao, Haichao; Cui, Xiuhong; Ma, Dongyuan; Zhang, Zhiguo; Yang, Xiaoyu; Guo, Yueshuai; Liu, Feng; Yuan, Li

    2017-01-01

    SUN (Sad1 and UNC84 domain containing)-domain proteins are reported to reside on the nuclear membrane playing distinct roles in nuclear dynamics. SUN5 is a new member of the SUN family, with little knowledge regarding its function. Here, we generated Sun5−/− mice and found that male mice were infertile. Most Sun5-null spermatozoa displayed a globozoospermia-like phenotype but they were actually acephalic spermatozoa. Additional studies revealed that SUN5 was located in the neck of the spermatozoa, anchoring sperm head to the tail, and without functional SUN5 the sperm head to tail coupling apparatus was detached from nucleus during spermatid elongation. Finally, we found that healthy heterozygous offspring could be obtained via intracytoplasmic injection of Sun5-mutated sperm heads for both male mice and patients. Our studies reveal the essential role of SUN5 in anchoring sperm head to the tail and provide a promising way to treat this kind of acephalic spermatozoa-associated male infertility. PMID:28945193

  9. A joint estimation detection of Glaucoma progression in 3D spectral domain optical coherence tomography optic nerve head images

    NASA Astrophysics Data System (ADS)

    Belghith, Akram; Bowd, Christopher; Weinreb, Robert N.; Zangwill, Linda M.

    2014-03-01

    Glaucoma is an ocular disease characterized by distinctive changes in the optic nerve head (ONH) and visual field. Glaucoma can strike without symptoms and causes blindness if it remains without treatment. Therefore, early disease detection is important so that treatment can be initiated and blindness prevented. In this context, important advances in technology for non-invasive imaging of the eye have been made providing quantitative tools to measure structural changes in ONH topography, an essential element for glaucoma detection and monitoring. 3D spectral domain optical coherence tomography (SD-OCT), an optical imaging technique, has been commonly used to discriminate glaucomatous from healthy subjects. In this paper, we present a new framework for detection of glaucoma progression using 3D SD-OCT images. In contrast to previous works that the retinal nerve fiber layer (RNFL) thickness measurement provided by commercially available spectral-domain optical coherence tomograph, we consider the whole 3D volume for change detection. To integrate a priori knowledge and in particular the spatial voxel dependency in the change detection map, we propose the use of the Markov Random Field to handle a such dependency. To accommodate the presence of false positive detection, the estimated change detection map is then used to classify a 3D SDOCT image into the "non-progressing" and "progressing" glaucoma classes, based on a fuzzy logic classifier. We compared the diagnostic performance of the proposed framework to existing methods of progression detection.

  10. A joint estimation detection of Glaucoma progression in 3D spectral domain optical coherence tomography optic nerve head images.

    PubMed

    Belghith, Akram; Bowd, Christopher; Weinreb, Robert N; Zangwill, Linda M

    2014-03-18

    Glaucoma is an ocular disease characterized by distinctive changes in the optic nerve head (ONH) and visual field. Glaucoma can strike without symptoms and causes blindness if it remains without treatment. Therefore, early disease detection is important so that treatment can be initiated and blindness prevented. In this context, important advances in technology for non-invasive imaging of the eye have been made providing quantitative tools to measure structural changes in ONH topography, an essential element for glaucoma detection and monitoring. 3D spectral domain optical coherence tomography (SD-OCT), an optical imaging technique, has been commonly used to discriminate glaucomatous from healthy subjects. In this paper, we present a new framework for detection of glaucoma progression using 3D SD-OCT images. In contrast to previous works that the retinal nerve fiber layer (RNFL) thickness measurement provided by commercially available spectral-domain optical coherence tomograph, we consider the whole 3D volume for change detection. To integrate a priori knowledge and in particular the spatial voxel dependency in the change detection map, we propose the use of the Markov Random Field to handle a such dependency. To accommodate the presence of false positive detection, the estimated change detection map is then used to classify a 3D SDOCT image into the "non-progressing" and "progressing" glaucoma classes, based on a fuzzy logic classifier. We compared the diagnostic performance of the proposed framework to existing methods of progression detection.

  11. Assistant Teachers in Head Start Classrooms: Comparing to and Working with Lead Teachers

    ERIC Educational Resources Information Center

    Curby, Timothy W.; Boyer, Caroline; Edwards, Taylor; Chavez, Catharine

    2012-01-01

    Research Findings: The purpose of the present study is to examine the degree to which assistant and lead teachers work together in Head Start classrooms in 3 domains: emotional support, classroom organization, and instructional support. Pairs of lead and assistant teachers from 14 Head Start classrooms were simultaneously observed for 1 morning to…

  12. Homeotic genes and the arthropod head: Expression patterns of the labial, proboscipedia, and Deformed genes in crustaceans and insects

    PubMed Central

    Abzhanov, Arhat; Kaufman, Thomas C.

    1999-01-01

    cDNA fragments of the homologues of the Drosophila head homeotic genes labial (lab), proboscipedia (pb), and Deformed (Dfd) have been isolated from the crustacean Porcellio scaber. Because the accumulation domains of the head homeotic complex (Hox) genes had not been previously reported for crustaceans, we studied the expression patterns of these genes in P. scaber embryos by using in situ hybridization. The P. scaber lab homologue is expressed in the developing second antennal segment and its appendages. This expression domain in crustaceans and in the homologous intercalary segment of insects suggests that the lab gene specified this metamere in the last common ancestor of these two groups. The expression domain of the P. scaber pb gene is in the posterior part of the second antennal segment. This domain, in contrast to that in insects, is colinear with the domains of other head genes in P. scaber, and it differs from the insect pb gene expression domain in the posterior mouthparts, suggesting that the insect and crustacean patterns evolved independently from a broader ancestral domain similar to that found in modern chelicerates. P. scaber Dfd is expressed in the mandibular segment and paragnaths (a pair of ventral mouthpart structures associated with the stomodeum) and differs from insects, where expression is in the mandibular and maxillary segments. Thus, like pb, Dfd shows a divergent Hox gene deployment. We conclude that homologous structures of the mandibulate head display striking differences in their underlying developmental programs related to Hox gene expression. PMID:10468590

  13. Yeast eIF4B binds to the head of the 40S ribosomal subunit and promotes mRNA recruitment through its N-terminal and internal repeat domains.

    PubMed

    Walker, Sarah E; Zhou, Fujun; Mitchell, Sarah F; Larson, Victoria S; Valasek, Leos; Hinnebusch, Alan G; Lorsch, Jon R

    2013-02-01

    Eukaryotic translation initiation factor (eIF)4B stimulates recruitment of mRNA to the 43S ribosomal pre-initiation complex (PIC). Yeast eIF4B (yeIF4B), shown previously to bind single-stranded (ss) RNA, consists of an N-terminal domain (NTD), predicted to be unstructured in solution; an RNA-recognition motif (RRM); an unusual domain comprised of seven imperfect repeats of 26 amino acids; and a C-terminal domain. Although the mechanism of yeIF4B action has remained obscure, most models have suggested central roles for its RRM and ssRNA-binding activity. We have dissected the functions of yeIF4B's domains and show that the RRM and its ssRNA-binding activity are dispensable in vitro and in vivo. Instead, our data indicate that the 7-repeats and NTD are the most critical domains, which mediate binding of yeIF4B to the head of the 40S ribosomal subunit via interaction with Rps20. This interaction induces structural changes in the ribosome's mRNA entry channel that could facilitate mRNA loading. We also show that yeIF4B strongly promotes productive interaction of eIF4A with the 43S•mRNA PIC in a manner required for efficient mRNA recruitment.

  14. Yeast eIF4B binds to the head of the 40S ribosomal subunit and promotes mRNA recruitment through its N-terminal and internal repeat domains

    PubMed Central

    Walker, Sarah E.; Zhou, Fujun; Mitchell, Sarah F.; Larson, Victoria S.; Valasek, Leos; Hinnebusch, Alan G.; Lorsch, Jon R.

    2013-01-01

    Eukaryotic translation initiation factor (eIF)4B stimulates recruitment of mRNA to the 43S ribosomal pre-initiation complex (PIC). Yeast eIF4B (yeIF4B), shown previously to bind single-stranded (ss) RNA, consists of an N-terminal domain (NTD), predicted to be unstructured in solution; an RNA-recognition motif (RRM); an unusual domain comprised of seven imperfect repeats of 26 amino acids; and a C-terminal domain. Although the mechanism of yeIF4B action has remained obscure, most models have suggested central roles for its RRM and ssRNA-binding activity. We have dissected the functions of yeIF4B’s domains and show that the RRM and its ssRNA-binding activity are dispensable in vitro and in vivo. Instead, our data indicate that the 7-repeats and NTD are the most critical domains, which mediate binding of yeIF4B to the head of the 40S ribosomal subunit via interaction with Rps20. This interaction induces structural changes in the ribosome’s mRNA entry channel that could facilitate mRNA loading. We also show that yeIF4B strongly promotes productive interaction of eIF4A with the 43S•mRNA PIC in a manner required for efficient mRNA recruitment. PMID:23236192

  15. Mental Health and Head Start: Teaching Adaptive Skills.

    ERIC Educational Resources Information Center

    Forness, Steven R.; Serna, Loretta A.; Kavale, Kenneth A.; Nielsen, Elizabeth

    1998-01-01

    Describes the use of a self-determination curriculum for mental-health intervention and primary prevention for Head Start children. The curriculum addresses critical adaptive-skills domains, including social skills, self-evaluation, self-direction, networking or friendship, collaboration or support seeking, problem solving and decision making, and…

  16. Realistic numerical modelling of human head tissue exposure to electromagnetic waves from cellular phones

    NASA Astrophysics Data System (ADS)

    Scarella, Gilles; Clatz, Olivier; Lanteri, Stéphane; Beaume, Grégory; Oudot, Steve; Pons, Jean-Philippe; Piperno, Sergo; Joly, Patrick; Wiart, Joe

    2006-06-01

    The ever-rising diffusion of cellular phones has brought about an increased concern for the possible consequences of electromagnetic radiation on human health. Possible thermal effects have been investigated, via experimentation or simulation, by several research projects in the last decade. Concerning numerical modeling, the power absorption in a user's head is generally computed using discretized models built from clinical MRI data. The vast majority of such numerical studies have been conducted using Finite Differences Time Domain methods, although strong limitations of their accuracy are due to heterogeneity, poor definition of the detailed structures of head tissues (staircasing effects), etc. In order to propose numerical modeling using Finite Element or Discontinuous Galerkin Time Domain methods, reliable automated tools for the unstructured discretization of human heads are also needed. Results presented in this article aim at filling the gap between human head MRI images and the accurate numerical modeling of wave propagation in biological tissues and its thermal effects. To cite this article: G. Scarella et al., C. R. Physique 7 (2006).

  17. Sensitivity Analysis of Hydraulic Head to Locations of Model Boundaries

    DOE PAGES

    Lu, Zhiming

    2018-01-30

    Sensitivity analysis is an important component of many model activities in hydrology. Numerous studies have been conducted in calculating various sensitivities. Most of these sensitivity analysis focus on the sensitivity of state variables (e.g. hydraulic head) to parameters representing medium properties such as hydraulic conductivity or prescribed values such as constant head or flux at boundaries, while few studies address the sensitivity of the state variables to some shape parameters or design parameters that control the model domain. Instead, these shape parameters are typically assumed to be known in the model. In this study, based on the flow equation, wemore » derive the equation (and its associated initial and boundary conditions) for sensitivity of hydraulic head to shape parameters using continuous sensitivity equation (CSE) approach. These sensitivity equations can be solved numerically in general or analytically in some simplified cases. Finally, the approach has been demonstrated through two examples and the results are compared favorably to those from analytical solutions or numerical finite difference methods with perturbed model domains, while numerical shortcomings of the finite difference method are avoided.« less

  18. Sensitivity Analysis of Hydraulic Head to Locations of Model Boundaries

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lu, Zhiming

    Sensitivity analysis is an important component of many model activities in hydrology. Numerous studies have been conducted in calculating various sensitivities. Most of these sensitivity analysis focus on the sensitivity of state variables (e.g. hydraulic head) to parameters representing medium properties such as hydraulic conductivity or prescribed values such as constant head or flux at boundaries, while few studies address the sensitivity of the state variables to some shape parameters or design parameters that control the model domain. Instead, these shape parameters are typically assumed to be known in the model. In this study, based on the flow equation, wemore » derive the equation (and its associated initial and boundary conditions) for sensitivity of hydraulic head to shape parameters using continuous sensitivity equation (CSE) approach. These sensitivity equations can be solved numerically in general or analytically in some simplified cases. Finally, the approach has been demonstrated through two examples and the results are compared favorably to those from analytical solutions or numerical finite difference methods with perturbed model domains, while numerical shortcomings of the finite difference method are avoided.« less

  19. Selecting soluble/foldable protein domains through single-gene or genomic ORF filtering: structure of the head domain of Burkholderia pseudomallei antigen BPSL2063.

    PubMed

    Gourlay, Louise J; Peano, Clelia; Deantonio, Cecilia; Perletti, Lucia; Pietrelli, Alessandro; Villa, Riccardo; Matterazzo, Elena; Lassaux, Patricia; Santoro, Claudio; Puccio, Simone; Sblattero, Daniele; Bolognesi, Martino

    2015-11-01

    The 1.8 Å resolution crystal structure of a conserved domain of the potential Burkholderia pseudomallei antigen and trimeric autotransporter BPSL2063 is presented as a structural vaccinology target for melioidosis vaccine development. Since BPSL2063 (1090 amino acids) hosts only one conserved domain, and the expression/purification of the full-length protein proved to be problematic, a domain-filtering library was generated using β-lactamase as a reporter gene to select further BPSL2063 domains. As a result, two domains (D1 and D2) were identified and produced in soluble form in Escherichia coli. Furthermore, as a general tool, a genomic open reading frame-filtering library from the B. pseudomallei genome was also constructed to facilitate the selection of domain boundaries from the entire ORFeome. Such an approach allowed the selection of three potential protein antigens that were also produced in soluble form. The results imply the further development of ORF-filtering methods as a tool in protein-based research to improve the selection and production of soluble proteins or domains for downstream applications such as X-ray crystallography.

  20. Tensin stabilizes integrin adhesive contacts in Drosophila.

    PubMed

    Torgler, Catherine N; Narasimha, Maithreyi; Knox, Andrea L; Zervas, Christos G; Vernon, Matthew C; Brown, Nicholas H

    2004-03-01

    We report the functional characterization of the Drosophila ortholog of tensin, a protein implicated in linking integrins to the cytoskeleton and signaling pathways. A tensin null was generated and is viable with wing blisters, a phenotype characteristic of loss of integrin adhesion. In tensin mutants, mechanical abrasion is required during wing expansion to cause wing blisters, suggesting that tensin strengthens integrin adhesion. The localization of tensin requires integrins, talin, and integrin-linked kinase. The N-terminal domain and C-terminal PTB domain of tensin provide essential recruitment signals. The intervening SH2 domain is not localized on its own. We suggest a model where tensin is recruited to sites of integrin adhesion via its PTB and N-terminal domains, localizing the SH2 domain so that it can interact with phosphotyrosine-containing proteins, which stabilize the integrin link to the cytoskeleton.

  1. Metamerism in cephalochordates and the problem of the vertebrate head.

    PubMed

    Onai, Takayuki; Adachi, Noritaka; Kuratani, Shigeru

    2017-01-01

    The vertebrate head characteristically exhibits a complex pattern with sense organs, brain, paired eyes and jaw muscles, and the brain case is not found in other chordates. How the extant vertebrate head has evolved remains enigmatic. Historically, there have been two conflicting views on the origin of the vertebrate head, segmental and non-segmental views. According to the segmentalists, the vertebrate head is organized as a metameric structure composed of segments equivalent to those in the trunk; a metamere in the vertebrate head was assumed to consist of a somite, a branchial arch and a set of cranial nerves, considering that the head evolved from rostral segments of amphioxus-like ancestral vertebrates. Non-segmentalists, however, considered that the vertebrate head was not segmental. In that case, the ancestral state of the vertebrate head may be non-segmented, and rostral segments in amphioxus might have been secondarily gained, or extant vertebrates might have evolved through radical modifications of amphioxus-like ancestral vertebrate head. Comparative studies of mesodermal development in amphioxus and vertebrate gastrula embryos have revealed that mesodermal gene expressions become segregated into two domains anteroposteriorly to specify the head mesoderm and trunk mesoderm only in vertebrates; in this segregation, key genes such as delta and hairy, involved in segment formation, are expressed in the trunk mesoderm, but not in the head mesoderm, strongly suggesting that the head mesoderm of extant vertebrates is not segmented. Taken together, the above finding possibly adds a new insight into the origin of the vertebrate head; the vertebrate head mesoderm would have evolved through an anteroposterior polarization of the paraxial mesoderm if the ancestral vertebrate had been amphioxus-like.

  2. Heading and head injuries in soccer.

    PubMed

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  3. Asymptotic analysis of the narrow escape problem in dendritic spine shaped domain: three dimensions

    NASA Astrophysics Data System (ADS)

    Li, Xiaofei; Lee, Hyundae; Wang, Yuliang

    2017-08-01

    This paper deals with the three-dimensional narrow escape problem in a dendritic spine shaped domain, which is composed of a relatively big head and a thin neck. The narrow escape problem is to compute the mean first passage time of Brownian particles traveling from inside the head to the end of the neck. The original model is to solve a mixed Dirichlet-Neumann boundary value problem for the Poisson equation in the composite domain, and is computationally challenging. In this paper we seek to transfer the original problem to a mixed Robin-Neumann boundary value problem by dropping the thin neck part, and rigorously derive the asymptotic expansion of the mean first passage time with high order terms. This study is a nontrivial three-dimensional generalization of the work in Li (2014 J. Phys. A: Math. Theor. 47 505202), where a two-dimensional analogue domain is considered.

  4. Head-Up Displays and Attention Capture

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III; Risser, Matthew

    2004-01-01

    The primary role of head-up displays (HUDs) is to provide primary flight, navigation, and guidance information to the pilot in a forward field-of-view on a head-up transparent screen. Therefore, this theoretically allows for optimal control of an aircraft through the simultaneous scanning of both instrument data and the out-the-window scene. However, despite significant aviation safety benefits afforded by HUDs, a number of accidents have shown that their use does not come without costs. The human factors community has identified significant issues related to the pilot distribution of near and far domain attentional resources because of the compellingness of symbology elements on the HUD; a concern termed, attention or cognitive capture. The paper describes the phenomena of attention capture and presents a selected survey of the literature on the etiology and potential prescriptions.

  5. Does Head Start differentially benefit children with risks targeted by the program’s service model?☆

    PubMed Central

    Miller, Elizabeth B.; Farkas, George; Duncan, Greg J.

    2015-01-01

    Data from the Head Start Impact Study (N = 3540) were used to test for differential benefits of Head Start after one program year and after kindergarten on pre-academic and behavior outcomes for children at risk in the domains targeted by the program’s comprehensive services. Although random assignment to Head Start produced positive treatment main effects on children’s pre-academic skills and behavior problems, residualized growth models showed that random assignment to Head Start did not differentially benefit the pre-academic skills of children with risk factors targeted by the Head Start service model. The models showed detrimental impacts of Head Start for maternal-reported behavior problems of high-risk children, but slightly more positive impacts for teacher-reported behavior. Policy implications for Head Start are discussed. PMID:26379369

  6. Quality of life scores predict survival among patients with head and neck cancer.

    PubMed

    Karvonen-Gutierrez, Carrie A; Ronis, David L; Fowler, Karen E; Terrell, Jeffrey E; Gruber, Stephen B; Duffy, Sonia A

    2008-06-01

    The purpose of this study was to examine whether quality of life (QOL) scores predict survival among patients with head and neck cancer, controlling for demographic, health behavior, and clinical variables. A self-administered questionnaire was given to 495 patients being treated for head and neck cancer while they were waiting to be seen for a clinic appointment. Data collected from the survey included demographics, health behaviors, and QOL as measured by Short Form-36 (SF-36) physical and mental component scores and the Head and Neck QOL scores. Clinical measures were collected by chart abstraction. Kaplan-Meier plots and univariate and multivariate Cox proportional hazards models were used to determine the association between QOL scores and survival time. After controlling for age, time since diagnosis, marital status, education, tumor site and stage, comorbidities, and smoking, the SF-36 physical component score and three of the four Head and Neck QOL scales (pain, eating, and speech domains) were associated with survival. Controlling for the same variables, the SF-36 mental component score and the emotional domain of the Head and Neck QOL were not associated with survival. QOL instruments may be valuable screening tools to identify patients who are at high risk for poor survival. Those with low QOL scores could be followed more closely, with the potential to identify recurrence earlier and perform salvage treatments, thereby possibly improving survival for this group of patients.

  7. Actomyosin-dependent formation of the mechanosensitive talin–vinculin complex reinforces actin anchoring

    PubMed Central

    Ciobanasu, Corina; Faivre, Bruno; Le Clainche, Christophe

    2014-01-01

    The force generated by the actomyosin cytoskeleton controls focal adhesion dynamics during cell migration. This process is thought to involve the mechanical unfolding of talin to expose cryptic vinculin-binding sites. However, the ability of the actomyosin cytoskeleton to directly control the formation of a talin–vinculin complex and the resulting activity of the complex are not known. Here we develop a microscopy assay with pure proteins in which the self-assembly of actomyosin cables controls the association of vinculin to a talin-micropatterned surface in a reversible manner. Quantifications indicate that talin refolding is limited by vinculin dissociation and modulated by the actomyosin network stability. Finally, we show that the activation of vinculin by stretched talin induces a positive feedback that reinforces the actin–talin–vinculin association. This in vitro reconstitution reveals the mechanism by which a key molecular switch senses and controls the connection between adhesion complexes and the actomyosin cytoskeleton. PMID:24452080

  8. Stochastic analysis of three-dimensional flow in a bounded domain

    USGS Publications Warehouse

    Naff, R.L.; Vecchia, A.V.

    1986-01-01

    A commonly accepted first-order approximation of the equation for steady state flow in a fully saturated spatially random medium has the form of Poisson's equation. This form allows for the advantageous use of Green's functions to solve for the random output (hydraulic heads) in terms of a convolution over the random input (the logarithm of hydraulic conductivity). A solution for steady state three- dimensional flow in an aquifer bounded above and below is presented; consideration of these boundaries is made possible by use of Green's functions to solve Poisson's equation. Within the bounded domain the medium hydraulic conductivity is assumed to be a second-order stationary random process as represented by a simple three-dimensional covariance function. Upper and lower boundaries are taken to be no-flow boundaries; the mean flow vector lies entirely in the horizontal dimensions. The resulting hydraulic head covariance function exhibits nonstationary effects resulting from the imposition of boundary conditions. Comparisons are made with existing infinite domain solutions.

  9. Influenza Virus Vaccine Based on the Conserved Hemagglutinin Stalk Domain

    PubMed Central

    Steel, John; Lowen, Anice C.; Wang, Taia T.; Yondola, Mark; Gao, Qinshan; Haye, Kester; García-Sastre, Adolfo; Palese, Peter

    2010-01-01

    ABSTRACT Although highly effective in the general population when well matched to circulating influenza virus strains, current influenza vaccines are limited in their utility due to the narrow breadth of protection they provide. The strain specificity of vaccines presently in use mirrors the exquisite specificity of the neutralizing antibodies that they induce, that is, antibodies which bind to the highly variable globular head domain of hemagglutinin (HA). Herein, we describe the construction of a novel immunogen comprising the conserved influenza HA stalk domain and lacking the globular head. Vaccination of mice with this headless HA construct elicited immune sera with broader reactivity than those obtained from mice immunized with a full-length HA. Furthermore, the headless HA vaccine provided full protection against death and partial protection against disease following lethal viral challenge. Our results suggest that the response induced by headless HA vaccines is sufficiently potent to warrant their further development toward a universal influenza virus vaccine. PMID:20689752

  10. Magnetic force microscopy study on wide adjacent track erasure in perpendicular magnetic write heads

    NASA Astrophysics Data System (ADS)

    Ruksasakchai, P.; Saengkaew, K.; Cheowanish, I.; Damrongsak, B.

    2017-09-01

    We used a phase-contrast magnetic force microscopy (MFM) to observe and analyze the failure of magnetic write heads due to the WATEr problem, which limits the off-track performance. During MFM imaging, the magnetic write head was energized by a DC current. The induced out-of-plane magnetic field was then detected by scanning a MFM probe across the surface of the magnetic write head. MFM images were then mapped with WATEr measured results from a spin stand method. Results showed that WATEr effect can be generated by several factors, i.e. the structure of magnetic domains and walls from material discontinuities and the magnetic field leakage at different locations on magnetic write heads. Understanding WATEr mechanisms is useful for design and process development engineers.

  11. The gap gene giant of Rhodnius prolixus is maternally expressed and required for proper head and abdomen formation.

    PubMed

    Lavore, Andrés; Pagola, Lucía; Esponda-Behrens, Natalia; Rivera-Pomar, Rolando

    2012-01-01

    The segmentation process in insects depends on a hierarchical cascade of gene activity. The first effectors downstream of the maternal activation are the gap genes, which divide the embryo in broad fields. We discovered a sequence corresponding to the leucine-zipper domain of the orthologue of the gene giant (Rp-gt) in traces from the genome of Rhodnius prolixus, a hemipteran with intermediate germ-band development. We cloned the Rp-gt gene from a normalized cDNA library and characterized its expression and function. Bioinformatic analysis of 12.5 kbp of genomic sequence containing the Rp-gt transcriptional unit shows a cluster of bona fide regulatory binding sites, which is similar in location and structure to the predicted posterior expression domain of the Drosophila orthologue. Rp-gt is expressed in ovaries and maternally supplied in the early embryo. The maternal contribution forms a gradient of scattered patches of mRNA in the preblastoderm embryo. Zygotic Rp-gt is expressed in two domains that after germ band extension are restricted to the head and the posterior growth zone. Parental RNAi shows that Rp-gt is required for proper head and abdomen formation. The head lacks mandibulary and maxillary appendages and shows reduced clypeus-labrum, while the abdomen lacks anterior segments. We conclude that Rp-gt is a gap gene on the head and abdomen and, in addition, has a function in patterning the anterior head capsule suggesting that the function of gt in hemipterans is more similar to dipterans than expected. Copyright © 2011. Published by Elsevier Inc.

  12. Formation of highly stable chimeric trimers by fusion of an adenovirus fiber shaft fragment with the foldon domain of bacteriophage t4 fibritin.

    PubMed

    Papanikolopoulou, Katerina; Forge, Vincent; Goeltz, Pierrette; Mitraki, Anna

    2004-03-05

    The folding of beta-structured, fibrous proteins is a largely unexplored area. A class of such proteins is used by viruses as adhesins, and recent studies revealed novel beta-structured motifs for them. We have been studying the folding and assembly of adenovirus fibers that consist of a globular C-terminal domain, a central fibrous shaft, and an N-terminal part that attaches to the viral capsid. The globular C-terminal, or "head" domain, has been postulated to be necessary for the trimerization of the fiber and might act as a registration signal that directs its correct folding and assembly. In this work, we replaced the head of the fiber by the trimerization domain of the bacteriophage T4 fibritin, termed "foldon." Two chimeric proteins, comprising the foldon domain connected at the C-terminal end of four fiber shaft repeats with or without the use of a natural linker sequence, fold into highly stable, SDS-resistant trimers. The structural signatures of the chimeric proteins as seen by CD and infrared spectroscopy are reported. The results suggest that the foldon domain can successfully replace the fiber head domain in ensuring correct trimerization of the shaft sequences. Biological implications and implications for engineering highly stable, beta-structured nanorods are discussed.

  13. Women Secondary Head Teachers in England: Where Are They Now?

    ERIC Educational Resources Information Center

    Fuller, Kay

    2017-01-01

    The underrepresentation of women in secondary school headship in England and elsewhere is an early and longstanding theme in the women and gender in educational leadership literature. The purpose of this article is to report findings from a statistical survey of secondary school head teachers across England. Data available in the public domain on…

  14. Processivity of the Kinesin-2 KIF3A Results from Rear Head Gating and Not Front Head Gating*

    PubMed Central

    Chen, Geng-Yuan; Arginteanu, David F. J.; Hancock, William O.

    2015-01-01

    The kinesin-2 family motor KIF3A/B works together with dynein to bidirectionally transport intraflagellar particles, melanosomes, and neuronal vesicles. Compared with kinesin-1, kinesin-2 is less processive, and its processivity is more sensitive to load, suggesting that processivity may be controlled by different gating mechanisms. We used stopped-flow and steady-state kinetics experiments, along with single-molecule and multimotor assays to characterize the entire kinetic cycle of a KIF3A homodimer that exhibits motility similar to that of full-length KIF3A/B. Upon first encounter with a microtubule, the motor rapidly exchanges both mADP and mATP. When adenosine 5′-[(β,γ)-imido]triphosphate was used to entrap the motor in a two-head-bound state, exchange kinetics were unchanged, indicating that rearward strain in the two-head-bound state does not alter nucleotide binding to the front head. A similar lack of front head gating was found when intramolecular strain was enhanced by shortening the neck linker domain from 17 to 14 residues. In single-molecule assays in ADP, the motor dissociates at 2.1 s−1, 20-fold slower than the stepping rate, demonstrating the presence of rear head gating. In microtubule pelleting assays, the KDMt is similar in ADP and ATP. The data and accompanying simulations suggest that, rather than KIF3A processivity resulting from strain-dependent regulation of nucleotide binding (front head gating), the motor spends a significant fraction of its hydrolysis cycle in a low affinity state but dissociates only slowly from this state. This work provides a mechanism to explain differences in the load-dependent properties of kinesin-1 and kinesin-2. PMID:25657001

  15. The N terminus of SKAP55 enables T cell adhesion to TCR and integrin ligands via distinct mechanisms

    PubMed Central

    Ophir, Michael J.; Liu, Beiyun C.

    2013-01-01

    The T cell receptor (TCR) triggers the assembly of “SLP-76 microclusters,” which mediate signals required for T cell activation. In addition to regulating integrin activation, we show that Src kinase–associated phosphoprotein of 55 kD (SKAP55) is required for microcluster persistence and movement, junctional stabilization, and integrin-independent adhesion via the TCR. These functions require the dimerization of SKAP55 and its interaction with the adaptor adhesion and degranulation-promoting adaptor protein (ADAP). A “tandem dimer” containing two ADAP-binding SKAP55 Src homology 3 (SH3) domains stabilized SLP-76 microclusters and promoted T cell adhesion via the TCR, but could not support adhesion to integrin ligands. Finally, the SKAP55 dimerization motif (DM) enabled the coimmunoprecipitation of the Rap1-dependent integrin regulator Rap1-GTP–interacting adaptor molecule (RIAM), the recruitment of talin into TCR-induced adhesive junctions, and “inside-out” signaling to β1 integrins. Our data indicate that SKAP55 dimers stabilize SLP-76 microclusters, couple SLP-76 to the force-generating systems responsible for microcluster movement, and enable adhesion via the TCR by mechanisms independent of RIAM, talin, and β1 integrins. PMID:24368808

  16. Selectins and chemokines use shared and distinct signals to activate β2 integrins in neutrophils

    PubMed Central

    Yago, Tadayuki; Zhang, Nan; Zhao, Liang; Abrams, Charles S.

    2018-01-01

    Rolling neutrophils receive signals while engaging P- and E-selectin and chemokines on inflamed endothelium. Selectin signaling activates β2 integrins to slow rolling velocities. Chemokine signaling activates β2 integrins to cause arrest. Despite extensive study, key aspects of these signaling cascades remain unresolved. Using complementary in vitro and in vivo assays, we found that selectin and chemokine signals in neutrophils triggered Rap1a-dependent and phosphatidylinositol-4-phosphate 5-kinase γ (PIP5Kγ90)–dependent pathways that induce integrin-dependent slow rolling and arrest. Interruption of both pathways, but not either pathway alone, blocked talin-1 recruitment to and activation of integrins. An isoform of PIP5Kγ90 lacking the talin-binding domain (PIP5Kγ87) could not activate integrins. Chemokines, but not selectins, used phosphatidylinositol-4,5-bisphosphate 3-kinase γ (PI3Kγ) in cooperation with Rap1a to mediate integrin-dependent slow rolling (at low chemokine concentrations), as well as arrest (at high chemokine concentrations). High levels of chemokines activated β2 integrins without selectin signals. When chemokines were limiting, they synergized with selectins to activate β2 integrins. PMID:29592875

  17. Selectins and chemokines use shared and distinct signals to activate β2 integrins in neutrophils.

    PubMed

    Yago, Tadayuki; Zhang, Nan; Zhao, Liang; Abrams, Charles S; McEver, Rodger P

    2018-04-10

    Rolling neutrophils receive signals while engaging P- and E-selectin and chemokines on inflamed endothelium. Selectin signaling activates β2 integrins to slow rolling velocities. Chemokine signaling activates β2 integrins to cause arrest. Despite extensive study, key aspects of these signaling cascades remain unresolved. Using complementary in vitro and in vivo assays, we found that selectin and chemokine signals in neutrophils triggered Rap1a-dependent and phosphatidylinositol-4-phosphate 5-kinase γ (PIP5Kγ90)-dependent pathways that induce integrin-dependent slow rolling and arrest. Interruption of both pathways, but not either pathway alone, blocked talin-1 recruitment to and activation of integrins. An isoform of PIP5Kγ90 lacking the talin-binding domain (PIP5Kγ87) could not activate integrins. Chemokines, but not selectins, used phosphatidylinositol-4,5-bisphosphate 3-kinase γ (PI3Kγ) in cooperation with Rap1a to mediate integrin-dependent slow rolling (at low chemokine concentrations), as well as arrest (at high chemokine concentrations). High levels of chemokines activated β2 integrins without selectin signals. When chemokines were limiting, they synergized with selectins to activate β2 integrins. © 2018 by The American Society of Hematology.

  18. In vitro characterization of the RS motif in N-terminal head domain of goldfish germinal vesicle lamin B3 necessary for phosphorylation of the p34cdc2 target serine by SRPK1☆

    PubMed Central

    Yamaguchi, Akihiko; Iwatani, Miho; Ogawa, Mariko; Kitano, Hajime; Matsuyama, Michiya

    2013-01-01

    The nuclear envelopes surrounding the oocyte germinal vesicles of lower vertebrates (fish and frog) are supported by the lamina, which consists of the protein lamin B3 encoded by a gene found also in birds but lost in the lineage leading to mammals. Like other members of the lamin family, goldfish lamin B3 (gfLB3) contains two putative consensus phosphoacceptor p34cdc2 sites (Ser-28 and Ser-398) for the M-phase kinase to regulate lamin polymerization on the N- and C-terminal regions flanking a central rod domain. Partial phosphorylation of gfLB3 occurs on Ser-28 in the N-terminal head domain in immature oocytes prior to germinal vesicle breakdown, which suggests continual rearrangement of lamins by a novel lamin kinase in fish oocytes. We applied the expression-screening method to isolate lamin kinases by using phosphorylation site Ser-28-specific monoclonal antibody and a vector encoding substrate peptides from a goldfish ovarian cDNA library. As a result, SRPK1 was screened as a prominent lamin kinase candidate. The gfLB3 has a short stretch of the RS repeats (9-SRASTVRSSRRS-20) upstream of the Ser-28, within the N-terminal head. This stretch of repeats is conserved among fish lamin B3 but is not found in other lamins. In vitro phosphorylation studies and GST-pull down assay revealed that SRPK1 bound to the region of sequential RS repeats (9–20) with affinity and recruited serine into the active site by a grab-and-pull manner. These results indicate SRPK1 may phosphorylate the p34cdc2 site in the N-terminal head of GV-lamin B3 at the RS motifs, which have the general property of aggregation. PMID:23772390

  19. System and method for manipulating domain pinning and reversal in ferromagnetic materials

    DOEpatents

    Silevitch, Daniel M.; Rosenbaum, Thomas F.; Aeppli, Gabriel

    2013-10-15

    A method for manipulating domain pinning and reversal in a ferromagnetic material comprises applying an external magnetic field to a uniaxial ferromagnetic material comprising a plurality of magnetic domains, where each domain has an easy axis oriented along a predetermined direction. The external magnetic field is applied transverse to the predetermined direction and at a predetermined temperature. The strength of the magnetic field is varied at the predetermined temperature, thereby isothermally regulating pinning of the domains. A magnetic storage device for controlling domain dynamics includes a magnetic hard disk comprising a uniaxial ferromagnetic material, a magnetic recording head including a first magnet, and a second magnet. The ferromagnetic material includes a plurality of magnetic domains each having an easy axis oriented along a predetermined direction. The second magnet is positioned adjacent to the magnetic hard disk and is configured to apply a magnetic field transverse to the predetermined direction.

  20. Crystallization of the C-terminal head domain of the avian adenovirus CELO long fibre

    PubMed Central

    Guardado Calvo, Pablo; Llamas-Saiz, Antonio L.; Langlois, Patrick; van Raaij, Mark J.

    2006-01-01

    Avian adenovirus CELO contains two different fibres: fibre 1, the long fibre, and fibre 2, the short fibre. The short fibre is responsible for binding to an unknown avian receptor and is essential for infection of birds. The long fibre is not essential, but is known to bind the coxsackievirus and adenovirus receptor protein. Both trimeric fibres are attached to the same penton base, of which each icosahedral virus contains 12 copies. The short fibre extends straight outwards, while the long fibre emerges at an angle. The carboxy-terminal amino acids 579–793 of the avian adenovirus long fibre have been expressed with an amino-terminal hexahistidine tag and the expressed trimeric protein has been purified by nickel-affinity chromatography and crystallized. Crystals were grown at low pH using PEG 10 000 as precipitant and belonged to space group C2. The crystals diffracted rotating-anode Cu Kα radiation to at least 1.9 Å resolution and a complete data set was collected from a single crystal to 2.2 Å resolution. Unit-cell parameters were a = 216.5, b = 59.2, c = 57.5 Å, β = 101.3°, suggesting one trimer per asymmetric unit and a solvent content of 46%. The long fibre head does not have significant sequence homology to any other protein of known structure and molecular-replacement attempts with known fibre-head structures were unsuccessful. However, a map calculated using SIRAS phasing shows a clear trimer with a shape similar to known adenovirus fibre-head structures. Structure solution is in progress. PMID:16682773

  1. Electromagnetic absorption in the head of adults and children due to mobile phone operation close to the head.

    PubMed

    de Salles, Alvaro A; Bulla, Giovani; Rodriguez, Claudio E Fernández

    2006-01-01

    The Specific Absorption Rate (SAR) produced by mobile phones in the head of adults and children is simulated using an algorithm based on the Finite Difference Time Domain (FDTD) method. Realistic models of the child and adult head are used. The electromagnetic parameters are fitted to these models. Comparison also are made with the SAR calculated in the children model when using adult human electromagnetic parameters values. Microstrip (or patch) antennas and quarter wavelength monopole antennas are used in the simulations. The frequencies used to feed the antennas are 1850 MHz and 850 MHz. The SAR results are compared with the available international recommendations. It is shown that under similar conditions, the 1g-SAR calculated for children is higher than that for the adults. When using the 10-year old child model, SAR values higher than 60% than those for adults are obtained.

  2. Shoulder and neck morbidity in quality of life after surgery for head and neck cancer.

    PubMed

    van Wilgen, C P; Dijkstra, P U; van der Laan, B F A M; Plukker, J Th; Roodenburg, J L N

    2004-10-01

    Quality of life has become a major issue in determining the outcome of treatment in head and neck surgery with curative intent. The aim of our study was to determine which factors in the postoperative care, especially shoulder and neck morbidity, are related to quality of life and how these outcomes compared between patients who had undergone surgery and a control group. We analyzed physical symptoms, psychological symptoms, and social and functional well-being at least 1 year after surgery and evaluated the differences in quality of life between patients who had undergone head and neck surgery and a control group. Depression scores contributed significantly to all domains of quality of life. Reduced shoulder abduction, shoulder pain, and neck pain are related to several domains of quality of life. The patient group scored significantly worse for social functioning and limitations from physical problems but scored significantly better for bodily pain and health changes. Depression and shoulder and neck morbidity are important factors in quality of life for patients who have undergone surgery for head and neck cancer. (c) 2004 Wiley Periodicals, Inc.

  3. Early Head Start and African American Families: Impacts and Mechanisms of Child Outcomes

    ERIC Educational Resources Information Center

    Harden, Brenda Jones; Sandstrom, Heather; Chazan-Cohen, Rachel

    2012-01-01

    Persistent disparities exist between African American children and their European American counterparts across developmental domains. Early childhood intervention may serve to promote more positive outcomes among African American children. The current study examined whether and how the Early Head Start (EHS) program benefited African American…

  4. Unfurling of the band 4.1, ezrin, radixin, moesin (FERM) domain of the merlin tumor suppressor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yogesha, S.D.; Sharff, Andrew J.; Giovannini, Marco

    The merlin-1 tumor suppressor is encoded by the Neurofibromatosis-2 (Nf2) gene and loss-of-function Nf2 mutations lead to nervous system tumors in man and to several tumor types in mice. Merlin is an ERM (ezrin, radixin, moesin) family cytoskeletal protein that interacts with other ERM proteins and with components of cell-cell adherens junctions (AJs). Merlin stabilizes the links of AJs to the actin cytoskeleton. Thus, its loss destabilizes AJs, promoting cell migration and invasion, which in Nf2{sup +/-} mice leads to highly metastatic tumors. Paradoxically, the 'closed' conformation of merlin-1, where its N-terminal four-point-one, ezrin, radixin, moesin (FERM) domain binds tomore » its C-terminal tail domain, directs its tumor suppressor functions. Here we report the crystal structure of the human merlin-1 head domain when crystallized in the presence of its tail domain. Remarkably, unlike other ERM head-tail interactions, this structure suggests that binding of the tail provokes dimerization and dynamic movement and unfurling of the F2 motif of the FERM domain. We conclude the 'closed' tumor suppressor conformer of merlin-1 is in fact an 'open' dimer whose functions are disabled by Nf2 mutations that disrupt this architecture.« less

  5. Modulation of WNT signaling activity is key to the formation of the embryonic head.

    PubMed

    Fossat, Nicolas; Jones, Vanessa; Garcia-Garcia, Maria J; Tam, Patrick P L

    2012-01-01

    The formation of the embryonic head begins with the assembly of the progenitor tissues of the brain, the head and face primordia and the foregut that are derived from the primary germ layers during gastrulation. Specification of the anterior-posterior polarity of major body parts and the morphogenesis of the head and brain specifically is driven by inductive signals including those mediated by BMP, Nodal, FGF and WNT. A critical role of β-catenin dependent WNT signalling activity for head morphogenesis has been revealed through the analysis of the phenotypic impact of loss of function mutation of an antagonist: DKK1, a transcriptional repressor: GSC; and the outcome of interaction of Dkk1 with genes coding three components of the canonical signalling pathway: the ligand WNT3, the co-receptor LRP6 and the transcriptional co-factor, β-catenin. The findings highlight the requirement of a stringent control of the timing, domain and level of canonical WNT signalling activity for the formation of the embryonic head.

  6. Longitudinal Detection of Optic Nerve Head Changes by Spectral Domain Optical Coherence Tomography in Early Experimental Glaucoma

    PubMed Central

    He, Lin; Yang, Hongli; Gardiner, Stuart K.; Williams, Galen; Hardin, Christy; Strouthidis, Nicholas G.; Fortune, Brad; Burgoyne, Claude F.

    2014-01-01

    Purpose. We determined if the detection of spectral-domain optical coherence tomography (SDOCT) optic nerve head (ONH) change precedes the detection of confocal scanning laser tomography (CSLT) ONH surface, SDOCT retinal nerve fiber layer (RNFL), scanning laser perimetry (SLP), and multifocal electroretinography (mfERG) change in eight experimental glaucoma (EG) eyes. Methods. Both eyes from eight monkeys were tested at least three times at baseline, and then every 2 weeks following laser-induced chronic unilateral IOP elevation. Event and trend-based definitions of onset in the control and EG eyes for 11 SDOCT neural and connective tissue, CSLT surface, SDOCT RNFL, SLP, and mfERG parameters were explored. The frequency and timing of onset for each parameter were compared using a logrank test. Results. Maximum post-laser IOP was 18 to 42 mm Hg in the EG eyes and 12 to 20 mm Hg in the control eyes. For event- and trend-based analyses, onsets were achieved earliest and most frequently within the ONH neural and connective tissues using SDOCT, and at the ONH surface using CSLT. SDOCT ONH neural and connective tissue parameter change preceded or coincided with CSLT ONH surface change in most EG eyes. The SDOCT and SLP measures of RNFL thickness, and mfERG measures of visual function demonstrated similar onset rates, but occurred later than SDOCT ONH and CSLT surface change, and in fewer eyes. Conclusions. SDOCT ONH change detection commonly precedes or coincides with CSLT ONH surface change detection, and consistently precedes RNFLT, SLP, and mfERG change detection in monkey experimental glaucoma. PMID:24255047

  7. A new head phantom with realistic shape and spatially varying skull resistivity distribution.

    PubMed

    Li, Jian-Bo; Tang, Chi; Dai, Meng; Liu, Geng; Shi, Xue-Tao; Yang, Bin; Xu, Can-Hua; Fu, Feng; You, Fu-Sheng; Tang, Meng-Xing; Dong, Xiu-Zhen

    2014-02-01

    Brain electrical impedance tomography (EIT) is an emerging method for monitoring brain injuries. To effectively evaluate brain EIT systems and reconstruction algorithms, we have developed a novel head phantom that features realistic anatomy and spatially varying skull resistivity. The head phantom was created with three layers, representing scalp, skull, and brain tissues. The fabrication process entailed 3-D printing of the anatomical geometry for mold creation followed by casting to ensure high geometrical precision and accuracy of the resistivity distribution. We evaluated the accuracy and stability of the phantom. Results showed that the head phantom achieved high geometric accuracy, accurate skull resistivity values, and good stability over time and in the frequency domain. Experimental impedance reconstructions performed using the head phantom and computer simulations were found to be consistent for the same perturbation object. In conclusion, this new phantom could provide a more accurate test platform for brain EIT research.

  8. Myosin binding protein C positioned to play a key role in regulation of muscle contraction: structure and interactions of domain C1.

    PubMed

    Ababou, Abdessamad; Rostkova, Elena; Mistry, Shreena; Le Masurier, Clare; Gautel, Mathias; Pfuhl, Mark

    2008-12-19

    Myosin binding protein C (MyBP-C) is a thick filament protein involved in the regulation of muscle contraction. Mutations in the gene for MyBP-C are the second most frequent cause of hypertrophic cardiomyopathy. MyBP-C binds to myosin with two binding sites, one at its C-terminus and another at its N-terminus. The N-terminal binding site, consisting of immunoglobulin domains C1 and C2 connected by a flexible linker, interacts with the S2 segment of myosin in a phosphorylation-regulated manner. It is assumed that the function of MyBP-C is to act as a tether that fixes the S1 heads in a resting position and that phosphorylation releases the S1 heads into an active state. Here, we report the structure and binding properties of domain C1. Using a combination of site-directed mutagenesis and NMR interaction experiments, we identified the binding site of domain C1 in the immediate vicinity of the S1-S2 hinge, very close to the light chains. In addition, we identified a zinc binding site on domain C1 in close proximity to the S2 binding site. Its zinc binding affinity (K(d) of approximately 10-20 microM) might not be sufficient for a physiological effect. However, the familial hypertrophic cardiomyopathy-related mutation of one of the zinc ligands, glutamine 210 to histidine, will significantly increase the binding affinity, suggesting that this mutation may affect S2 binding. The close proximity of the C1 binding site to the hinge, the light chains and the S1 heads also provides an explanation for recent observations that (a) shorter fragments of MyBP-C unable to act as a tether still have an effect on the actomyosin ATPase and (b) as to why the myosin head positions in phosphorylated wild-type mice and MyBP-C knockout mice are so different: Domain C1 bound to the S1-S2 hinge is able to manipulate S1 head positions, thus influencing force generation without tether. The potentially extensive extra interactions of C1 are expected to keep it in place, while phosphorylation

  9. Myosin Binding Protein C Positioned to Play a Key Role in Regulation of Muscle Contraction: Structure and Interactions of Domain C1

    PubMed Central

    Ababou, Abdessamad; Rostkova, Elena; Mistry, Shreena; Masurier, Clare Le; Gautel, Mathias; Pfuhl, Mark

    2008-01-01

    Myosin binding protein C (MyBP-C) is a thick filament protein involved in the regulation of muscle contraction. Mutations in the gene for MyBP-C are the second most frequent cause of hypertrophic cardiomyopathy. MyBP-C binds to myosin with two binding sites, one at its C-terminus and another at its N-terminus. The N-terminal binding site, consisting of immunoglobulin domains C1 and C2 connected by a flexible linker, interacts with the S2 segment of myosin in a phosphorylation-regulated manner. It is assumed that the function of MyBP-C is to act as a tether that fixes the S1 heads in a resting position and that phosphorylation releases the S1 heads into an active state. Here, we report the structure and binding properties of domain C1. Using a combination of site-directed mutagenesis and NMR interaction experiments, we identified the binding site of domain C1 in the immediate vicinity of the S1–S2 hinge, very close to the light chains. In addition, we identified a zinc binding site on domain C1 in close proximity to the S2 binding site. Its zinc binding affinity (Kd of approximately 10–20 μM) might not be sufficient for a physiological effect. However, the familial hypertrophic cardiomyopathy-related mutation of one of the zinc ligands, glutamine 210 to histidine, will significantly increase the binding affinity, suggesting that this mutation may affect S2 binding. The close proximity of the C1 binding site to the hinge, the light chains and the S1 heads also provides an explanation for recent observations that (a) shorter fragments of MyBP-C unable to act as a tether still have an effect on the actomyosin ATPase and (b) as to why the myosin head positions in phosphorylated wild-type mice and MyBP-C knockout mice are so different: Domain C1 bound to the S1–S2 hinge is able to manipulate S1 head positions, thus influencing force generation without tether. The potentially extensive extra interactions of C1 are expected to keep it in place, while

  10. Tx/Rx Head Coil Induces Less RF Transmit-Related Heating than Body Coil in Conductive Metallic Objects Outside the Active Area of the Head Coil

    PubMed Central

    Nagy, Zoltan; Oliver-Taylor, Aaron; Kuehne, Andre; Goluch, Sigrun; Weiskopf, Nikolaus

    2017-01-01

    The transmit–receive (Tx/Rx) birdcage head coil is often used for excitation instead of the body coil because of the presumably lower risk of heating in and around conductive implants. However, this common practice has not been systematically tested. To investigate whether the Tx/Rx birdcage head coil produces less heating than the body coil when scanning individuals with implants, we used a 3T clinical scanner and made temperature measurements around a straight 15 cm conductor using either the Tx/Rx body or the head coil for excitation. Additionally, the transmitted fields of a Tx/Rx head coil were measured both in air and in gel using a resonant and a non-resonant B field probes as well as a non-resonant E field probe. Simulations using a finite-difference time domain solver were compared with the experimental findings. When the body coil was used for excitation, we observed heating around the 15 cm wire at various anatomical locations (both within and outside of the active volume of the head coil). Outside its active area, no such heating was observed while using the Tx/Rx head coil for excitation. The E and B fields of the Tx/Rx birdcage head coil extended well-beyond the physical dimensions of the coil. In air, the fields were monotonically decreasing, while in gel they were more complex with local maxima at the end of the ASTM phantom. These experimental findings were line with the simulations. While caution must always be exercised when scanning individuals with metallic implants, these findings support the use of the Tx/Rx birdcage head coil in place of the body coil at 3T in order to reduce the risk of heating in and around conductive implants that are remote from the head coil. PMID:28184184

  11. Prevalence and nature of survivorship needs in patients with head and neck cancer.

    PubMed

    Giuliani, Meredith; McQuestion, Maurene; Jones, Jennifer; Papadakos, Janet; Le, Lisa W; Alkazaz, Nour; Cheng, Terry; Waldron, John; Catton, Pamela; Ringash, Jolie

    2016-07-01

    The purpose of this study was to determine the number, type, and predictors of patients with head and neck cancer unmet survivorship needs. This study accrued patients with head and neck cancer at any time point in their survivorship course, and they completed a survey, including demographic information and the Cancer Survivors' Unmet Needs Measure (CaSUN). The median age of the 158 participants was 64 years. Ninety-six patients (61%) reported at least one unmet need on the CaSUN and 6 patients had a very high number of needs between 31 and 35. The mean number of unmet needs was 5.8 ± 8.9. Comprehensive Cancer Care was the most common domain of unmet need (n = 69; 45%). Younger age, earlier survivorship phase, and worse quality of life were associated with increased survivorship unmet needs on multivariable analysis. A high proportion of patients with head and neck cancer have unmet needs. These data can guide the development of head and neck survivorship programs. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1097-1103, 2016. © 2016 Wiley Periodicals, Inc.

  12. CT-detected intracranial hemorrhage among patients with head injury in Lagos, Nigeria.

    PubMed

    Eze, Cletus Uche; Abonyi, Livinus Chibuzo; Olowoyeye, Omodele; Njoku, Jerome; Ohagwu, Christopher; Babalola, Sherifat

    2013-01-01

    To evaluate the computed tomography (CT) findings of intracranial hemorrhage among patients with head trauma in Lagos, Nigeria. In this retrospective, cross-sectional study, a convenience sample of 500 patients with head trauma who had diagnostic cranial CT scans was selected. All the radiological reports and CT scans of patients with head trauma were retrieved in the hospitals selected as study sites. The reports were sorted into 2 groups - normal findings and intracranial bleeding. The reports of intracranial bleeding were sorted again into different classes of intracranial bleeding as identified by the radiologist who reported it. All data were analyzed using the Epi Info public domain software package. The chi-square test was used to measure the statistical significance of study results at P < .05. Most of the study subjects (68%) were men. Traffic accidents accounted for 44% of all the head traumas found in the study, and 58% of the head traumas resulted in intracranial bleeding. Among the hemorrhages found, 37% were intracerebral, 25% were subdural, 16% were intraventricular, 15% were subarachnoid, and 7% were epidural. Intracranial hemorrhage was a common consequence of acute head trauma sustained from traffic accidents in the population studied, with intracerebral hemorrhage being the most prevalent type. Traffic accidents are the main cause of acute head trauma in Lagos, Nigeria. The use of CT for early diagnosis of intracranial hemorrhage appears justifiable.

  13. Dropped head congenital muscular dystrophy caused by de novo mutations in LMNA.

    PubMed

    Karaoglu, Pakize; Quizon, Nicolas; Pergande, Matthias; Wang, Haicui; Polat, Ayşe Ipek; Ersen, Ayca; Özer, Erdener; Willkomm, Lena; Hiz Kurul, Semra; Heredia, Raúl; Yis, Uluç; Selcen, Duygu; Çirak, Sebahattin

    2017-04-01

    Dropped head syndrome is an easily recognizable clinical presentation of Lamin A/C-related congenital muscular dystrophy. Patients usually present in the first year of life with profound neck muscle weakness, dropped head, and elevated serum creatine kinase. Two patients exhibited head drop during infancy although they were able to sit independently. Later they developed progressive axial and limb-girdle weakness. Creatine kinase levels were elevated and muscle biopsies of both patients showed severe dystrophic changes. The distinctive clinical hallmark of the dropped head led us to the diagnosis of Lamin A/C-related congenital muscular dystrophy, with a pathogenic de novo mutation p.Glu31del in the head domain of the Lamin A/C gene in both patients. Remarkably, one patient also had a central involvement with white matter changes on brain magnetic resonance imaging. Lamin A/C-related dropped-head syndrome is a rapidly progressive congenital muscular dystrophy and may lead to loss of ambulation, respiratory insufficiency, and cardiac complications. Thus, the genetic diagnosis of dropped-head syndrome as L-CMD and the implicated clinical care protocols are of vital importance for these patients. This disease may be underdiagnosed, as only a few genetically confirmed cases have been reported. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  14. Structure-transfection activity relationships in a series of novel cationic lipids with heterocyclic head-groups.

    PubMed

    Ivanova, Ekaterina A; Maslov, Mikhail A; Kabilova, Tatyana O; Puchkov, Pavel A; Alekseeva, Anna S; Boldyrev, Ivan A; Vlassov, Valentin V; Serebrennikova, Galina A; Morozova, Nina G; Zenkova, Marina A

    2013-11-07

    Cationic liposomes are promising candidates for the delivery of various therapeutic nucleic acids. Here, we report a convenient synthesis of carbamate-type cationic lipids with various hydrophobic domains (tetradecanol, dialkylglycerol, cholesterol) and positively charged head-groups (pyridinium, N-methylimidazolium, N-methylmorpholinium) and data on the structure-transfection activity relationships. It was found that single-chain lipids possess high surface activity, which correlates with high cytotoxicity due to their ability to disrupt the cellular membrane by combined hydrophobic and electrostatic interactions. Liposomes containing these lipids also display high cytotoxicity with respect to all cell lines. Irrespective of chemical structures, all cationic lipids form liposomes with similar sizes and surface potentials. The characteristics of complexes composed of cationic liposomes and nucleic acids depend mostly on the type of nucleic acid and P/N ratios. In the case of oligodeoxyribonucleotide delivery, the transfection activity depends on the type of cationic head-group regardless of the type of hydrophobic domain: all types of cationic liposomes mediate efficient oligonucleotide transfer into 80-90% of the eukaryotic cells, and liposomes based on lipids with N-methylmorpholinium cationic head-group display the highest transfection activity. In the case of plasmid DNA and siRNA, the type of hydrophobic domain determines the transfection activity: liposomes composed of cholesterol-based lipids were the most efficient in DNA transfer, while liposomes containing glycerol-based lipids exhibited reasonable activity in siRNA delivery under serum-free conditions.

  15. Active head rotations and eye-head coordination

    NASA Technical Reports Server (NTRS)

    Zangemeister, W. H.; Stark, L.

    1981-01-01

    It is pointed out that head movements play an important role in gaze. The interaction between eye and head movements involves both their shared role in directing gaze and the compensatory vestibular ocular reflex. The dynamics of head trajectories are discussed, taking into account the use of parameterization to obtain the peak velocity, peak accelerations, the times of these extrema, and the duration of the movement. Attention is given to the main sequence, neck muscle EMG and details of the head-movement trajectory, types of head model accelerations, the latency of eye and head movement in coordinated gaze, gaze latency as a function of various factors, and coordinated gaze types. Clinical examples of gaze-plane analysis are considered along with the instantaneous change of compensatory eye movement (CEM) gain, and aspects of variability.

  16. Free fibula flap: assessment of quality of life of patients with head and neck cancer who have had defects reconstructed.

    PubMed

    Zhang, Xu; Li, Meng-Jie; Fang, Qi-Gen; Li, Zhen-Ning; Li, Wen-Lu; Sun, Chang-Fu

    2013-11-01

    This study investigated the quality of life (QoL) of patients with head and neck cancer undergoing immediate reconstruction of the mandible with free fibula flap. From March 2006 to January 2011, the QoL of 42 patients was assessed using the Medical Outcomes Study Short Form 36 and the University of Washington QoL (version 4) questionnaires. The assessments were performed at least 24 months after surgery. A total of 31 of the 42 questionnaires (73.8%) were returned. The length of harvested fibula varied from 17.5 to 26.1 cm. In the Short Form 36, the lowest-scoring domain was vitality, whereas the highest scores occurred in physical role. According to the University of Washington QoL, the key domains affected by surgery are chewing, speech, and appearance. The domain of pain has the best score. There was a significant effect on the QoL of patients with head and neck cancer with resections of the mandible who had undergone free fibula flap reconstruction. Data from this study may provide useful information for physicians and patients, which may be of value during discussion of treatment modalities for head and neck cancers.

  17. Barriers and Facilitators to Implementing the HEADS-ED: A Rapid Screening Tool for Pediatric Patients in Emergency Departments.

    PubMed

    MacWilliams, Kate; Curran, Janet; Racek, Jakub; Cloutier, Paula; Cappelli, Mario

    2017-12-01

    This study sought to identify barriers and facilitators to the implementation of the HEADS-ED, a screening tool appropriate for use in the emergency department (ED) that facilitates standardized assessments, discharge planning, charting, and linking pediatric mental health patients to appropriate community resources. A qualitative theory-based design was used to identify barriers and facilitators to implementing the HEADS-ED tool. Focus groups were conducted with participants recruited from 6 different ED settings across 2 provinces (Ontario and Nova Scotia). The Theoretical Domains Framework was used as a conceptual framework to guide data collection and to identify themes from focus group discussions. The following themes spanning 12 domains were identified as reflective of participants' beliefs about the barriers and facilitators to implementing the HEADS-ED tool: knowledge, skills, beliefs about capabilities, social professional role and identity, optimism, beliefs about consequences, reinforcement, environmental context and resources, social influences, emotion, behavioral regulation and memory, and attention and decision process. The HEADS-ED has the potential to address the need for better discharge planning, complete charting, and standardized assessments for the increasing population of pediatric mental health patients who present to EDs. This study has identified potential barriers and facilitators, which should be considered when developing an implementation plan for adopting the HEADS-ED tool into practice within EDs.

  18. Trapping and Injecting Single Domain Walls in Magnetic Wire by Local Fields

    NASA Astrophysics Data System (ADS)

    Vázquez, Manuel; Basheed, G. A.; Infante, Germán; Del Real, Rafael P.

    2012-01-01

    A single domain wall (DW) moves at linearly increasing velocity under an increasing homogeneous drive magnetic field. Present experiments show that the DW is braked and finally trapped at a given position when an additional antiparallel local magnetic field is applied. That position and its velocity are further controlled by suitable tuning of the local field. In turn, the parallel local field of small amplitude does not significantly affect the effective wall speed at long distance, although it generates tail-to-tail and head-to-head pairs of walls moving along opposite directions when that field is strong enough.

  19. The science of shrinking human heads: tribal warfare and revenge among the South American Jivaro-Shuar.

    PubMed

    Jandial, Rahul; Hughes, Samuel A; Aryan, Henry E; Marshall, Lawrence F; Levy, Michael L

    2004-11-01

    THE PRACTICE OF "head-shrinking" has been the proper domain not of Africa but rather of the denizens of South America. Specifically, in the post-Columbian period, it has been most famously the practice of a tribe of indigenous people commonly called the Jivaro or Jivaro-Shuar. The evidence suggests that the Jivaro-Shuar are merely the last group to retain a custom widespread in northwestern South America. In both ceramic and textile art of the pre-Columbian residents of Peru, the motif of trophy heads smaller than normal life-size heads commonly recurs; the motif is seen even in surviving carvings in stone and shell. Moreover, although not true shrunken heads, trophy heads found in late pre-Columbian and even post-Columbian graves of the region demonstrate techniques of display very similar to those used by the Jivaro-Shuar, at least some of which are best understood in the context of head-shrinking. Regardless, the Jivaro-Shuar and their practices provide an illustrative counterexample to popular myth regarding the culture and science of the shrinking of human heads.

  20. An RNA Domain Imparts Specificity and Selectivity to a Viral DNA Packaging Motor

    PubMed Central

    Zhao, Wei; Jardine, Paul J.

    2015-01-01

    ABSTRACT During assembly, double-stranded DNA viruses, including bacteriophages and herpesviruses, utilize a powerful molecular motor to package their genomic DNA into a preformed viral capsid. An integral component of the packaging motor in the Bacillus subtilis bacteriophage ϕ29 is a viral genome-encoded pentameric ring of RNA (prohead RNA [pRNA]). pRNA is a 174-base transcript comprised of two domains, domains I and II. Early studies initially isolated a 120-base form (domain I only) that retains high biological activity in vitro; hence, no function could be assigned to domain II. Here we define a role for this domain in the packaging process. DNA packaging using restriction digests of ϕ29 DNA showed that motors with the 174-base pRNA supported the correct polarity of DNA packaging, selectively packaging the DNA left end. In contrast, motors containing the 120-base pRNA had compromised specificity, packaging both left- and right-end fragments. The presence of domain II also provides selectivity in competition assays with genomes from related phages. Furthermore, motors with the 174-base pRNA were restrictive, in that they packaged only one DNA fragment into the head, whereas motors with the 120-base pRNA packaged several fragments into the head, indicating multiple initiation events. These results show that domain II imparts specificity and stringency to the motor during the packaging initiation events that precede DNA translocation. Heteromeric rings of pRNA demonstrated that one or two copies of domain II were sufficient to impart this selectivity/stringency. Although ϕ29 differs from other double-stranded DNA phages in having an RNA motor component, the function provided by pRNA is carried on the motor protein components in other phages. IMPORTANCE During virus assembly, genome packaging involves the delivery of newly synthesized viral nucleic acid into a protein shell. In the double-stranded DNA phages and herpesviruses, this is accomplished by a powerful

  1. An RNA Domain Imparts Specificity and Selectivity to a Viral DNA Packaging Motor.

    PubMed

    Zhao, Wei; Jardine, Paul J; Grimes, Shelley

    2015-12-01

    During assembly, double-stranded DNA viruses, including bacteriophages and herpesviruses, utilize a powerful molecular motor to package their genomic DNA into a preformed viral capsid. An integral component of the packaging motor in the Bacillus subtilis bacteriophage ϕ29 is a viral genome-encoded pentameric ring of RNA (prohead RNA [pRNA]). pRNA is a 174-base transcript comprised of two domains, domains I and II. Early studies initially isolated a 120-base form (domain I only) that retains high biological activity in vitro; hence, no function could be assigned to domain II. Here we define a role for this domain in the packaging process. DNA packaging using restriction digests of ϕ29 DNA showed that motors with the 174-base pRNA supported the correct polarity of DNA packaging, selectively packaging the DNA left end. In contrast, motors containing the 120-base pRNA had compromised specificity, packaging both left- and right-end fragments. The presence of domain II also provides selectivity in competition assays with genomes from related phages. Furthermore, motors with the 174-base pRNA were restrictive, in that they packaged only one DNA fragment into the head, whereas motors with the 120-base pRNA packaged several fragments into the head, indicating multiple initiation events. These results show that domain II imparts specificity and stringency to the motor during the packaging initiation events that precede DNA translocation. Heteromeric rings of pRNA demonstrated that one or two copies of domain II were sufficient to impart this selectivity/stringency. Although ϕ29 differs from other double-stranded DNA phages in having an RNA motor component, the function provided by pRNA is carried on the motor protein components in other phages. During virus assembly, genome packaging involves the delivery of newly synthesized viral nucleic acid into a protein shell. In the double-stranded DNA phages and herpesviruses, this is accomplished by a powerful molecular motor

  2. Formation of the Embryonic Head in the Mouse: Attributes of a Gene Regulatory Network.

    PubMed

    Tam, Patrick P L; Fossat, Nicolas; Wilkie, Emilie; Loebel, David A F; Ip, Chi Kin; Ramialison, Mirana

    2016-01-01

    The embryonic head is the first major body part to be constructed during embryogenesis. The allocation and the assembly of the progenitor tissues, which start at gastrulation, are accompanied by the spatiotemporal activity of transcription factors and signaling pathways that drives lineage specification, germ layer formation, and cell/tissue movement. The morphogenesis, regionalization, and patterning of the brain and craniofacial structures rely on the function of LIM-domain, homeodomain, and basic helix-loop-helix transcription factors. These factors constitute the central nodes of a gene regulatory network (GRN) which encompasses and intersects with signaling pathways involved with head formation. It is predicted that the functional output of this "head GRN" impacts on cellular function and cell-cell interactions that are essential for lineage differentiation and tissue modeling, which are key processes underpinning the formation of the head. © 2016 Elsevier Inc. All rights reserved.

  3. Flexibility of the Head-Stalk Linker Domain of Paramyxovirus HN Glycoprotein Is Essential for Triggering Virus Fusion.

    PubMed

    Adu-Gyamfi, Emmanuel; Kim, Lori S; Jardetzky, Theodore S; Lamb, Robert A

    2016-10-15

    The Paramyxoviridae comprise a large family of enveloped, negative-sense, single-stranded RNA viruses with significant economic and public health implications. For nearly all paramyxoviruses, infection is initiated by fusion of the viral and host cell plasma membranes in a pH-independent fashion. Fusion is orchestrated by the receptor binding protein hemagglutinin-neuraminidase (HN; also called H or G depending on the virus type) protein and a fusion (F) protein, the latter undergoing a major refolding process to merge the two membranes. Mechanistic details regarding the coupling of receptor binding to F activation are not fully understood. Here, we have identified the flexible loop region connecting the bulky enzymatically active head and the four-helix bundle stalk to be essential for fusion promotion. Proline substitution in this region of HN of parainfluenza virus 5 (PIV5) and Newcastle disease virus HN abolishes cell-cell fusion, whereas HN retains receptor binding and neuraminidase activity. By using reverse genetics, we engineered recombinant PIV5-EGFP viruses with mutations in the head-stalk linker region of HN. Mutations in this region abolished virus recovery and infectivity. In sum, our data suggest that the loop region acts as a "hinge" around which the bulky head of HN swings to-and-fro to facilitate timely HN-mediate F-triggering, a notion consistent with the stalk-mediated activation model of paramyxovirus fusion. Paramyxovirus fusion with the host cell plasma membrane is essential for virus infection. Membrane fusion is orchestrated via interaction of the receptor binding protein (HN, H, or G) with the viral fusion glycoprotein (F). Two distinct models have been suggested to describe the mechanism of fusion: these include "the clamp" and the "provocateur" model of activation. By using biochemical and reverse genetics tools, we have obtained strong evidence in favor of the HN stalk-mediated activation of paramyxovirus fusion. Specifically, our data

  4. Flexibility of the Head-Stalk Linker Domain of Paramyxovirus HN Glycoprotein Is Essential for Triggering Virus Fusion

    PubMed Central

    Adu-Gyamfi, Emmanuel; Kim, Lori S.; Jardetzky, Theodore S.

    2016-01-01

    ABSTRACT The Paramyxoviridae comprise a large family of enveloped, negative-sense, single-stranded RNA viruses with significant economic and public health implications. For nearly all paramyxoviruses, infection is initiated by fusion of the viral and host cell plasma membranes in a pH-independent fashion. Fusion is orchestrated by the receptor binding protein hemagglutinin-neuraminidase (HN; also called H or G depending on the virus type) protein and a fusion (F) protein, the latter undergoing a major refolding process to merge the two membranes. Mechanistic details regarding the coupling of receptor binding to F activation are not fully understood. Here, we have identified the flexible loop region connecting the bulky enzymatically active head and the four-helix bundle stalk to be essential for fusion promotion. Proline substitution in this region of HN of parainfluenza virus 5 (PIV5) and Newcastle disease virus HN abolishes cell-cell fusion, whereas HN retains receptor binding and neuraminidase activity. By using reverse genetics, we engineered recombinant PIV5-EGFP viruses with mutations in the head-stalk linker region of HN. Mutations in this region abolished virus recovery and infectivity. In sum, our data suggest that the loop region acts as a “hinge” around which the bulky head of HN swings to-and-fro to facilitate timely HN-mediate F-triggering, a notion consistent with the stalk-mediated activation model of paramyxovirus fusion. IMPORTANCE Paramyxovirus fusion with the host cell plasma membrane is essential for virus infection. Membrane fusion is orchestrated via interaction of the receptor binding protein (HN, H, or G) with the viral fusion glycoprotein (F). Two distinct models have been suggested to describe the mechanism of fusion: these include “the clamp” and the “provocateur” model of activation. By using biochemical and reverse genetics tools, we have obtained strong evidence in favor of the HN stalk-mediated activation of paramyxovirus

  5. Convergent Evolution of Head Crests in Two Domesticated Columbids Is Associated with Different Missense Mutations in EphB2

    PubMed Central

    Vickrey, Anna I.; Domyan, Eric T.; Horvath, Martin P.; Shapiro, Michael D.

    2015-01-01

    Head crests are important display structures in wild bird species and are also common in domesticated lineages. Many breeds of domestic rock pigeon (Columba livia) have crests of reversed occipital feathers, and this recessive trait is associated with a nonsynonymous coding mutation in the intracellular kinase domain of EphB2 (Ephrin receptor B2). The domestic ringneck dove (Streptopelia risoria) also has a recessive crested morph with reversed occipital feathers, and interspecific crosses between crested doves and pigeons produce crested offspring, suggesting a similar genetic basis for this trait in both species. We therefore investigated EphB2 as a candidate for the head crest phenotype of ringneck doves and identified a nonsynonymous coding mutation in the intracellular kinase domain that is significantly associated with the crested morph. This mutation is over 100 amino acid positions away from the crest mutation found in rock pigeons, yet both mutations are predicted to negatively affect the function of ATP-binding pocket. Furthermore, bacterial toxicity assays suggest that “crest” mutations in both species severely impact kinase activity. We conclude that head crests are associated with different mutations in the same functional domain of the same gene in two different columbid species, thereby representing striking evolutionary convergence in morphology and molecules. PMID:26104009

  6. Head lice

    MedlinePlus

    Pediculosis capitis - head lice ... Head lice infect hair on the head. Tiny eggs on the hair look like flakes of dandruff . However, ... flaking off the scalp, they stay in place. Head lice can live up to 30 days on a ...

  7. Structure of the extracellular domains of the human interleukin-6 receptor α-chain

    PubMed Central

    Varghese, J. N.; Moritz, R. L.; Lou, M.-Z.; van Donkelaar, A.; Ji, H.; Ivancic, N.; Branson, K. M.; Hall, N. E.; Simpson, R. J.

    2002-01-01

    Dysregulated production of IL-6 and its receptor (IL-6R) are implicated in the pathogenesis of multiple myeloma, autoimmune diseases and prostate cancer. The IL-6R complex comprises two molecules each of IL-6, IL-6R, and the signaling molecule, gp130. Here, we report the x-ray structure (2.4 Å) of the IL-6R ectodomains. The N-terminal strand of the Ig-like domain (D1) is disulfide-bonded to domain D2, and domains D2 and D3, the cytokine-binding domain, are structurally similar to known cytokine-binding domains. The head-to-tail packing of two closely associated IL-6R molecules observed in the crystal may be representative of the configuration of the physiological dimer of IL-6R and provides new insight into the architecture of the IL-6R complex. PMID:12461182

  8. Head Lice

    MedlinePlus

    What are head lice? Head lice are tiny insects that live on people's heads. Adult lice are about the size of sesame seeds. The eggs, called ... often at the neckline and behind the ears. Head lice are parasites, and they need to feed on ...

  9. Definite differences between in vitro actin-myosin sliding and muscle contraction as revealed using antibodies to myosin head.

    PubMed

    Sugi, Haruo; Chaen, Shigeru; Kobayashi, Takakazu; Abe, Takahiro; Kimura, Kazushige; Saeki, Yasutake; Ohnuki, Yoshiki; Miyakawa, Takuya; Tanokura, Masaru; Sugiura, Seiryo

    2014-01-01

    Muscle contraction results from attachment-detachment cycles between myosin heads extending from myosin filaments and actin filaments. It is generally believed that a myosin head first attaches to actin, undergoes conformational changes to produce force and motion in muscle, and then detaches from actin. Despite extensive studies, the molecular mechanism of myosin head conformational changes still remains to be a matter for debate and speculation. The myosin head consists of catalytic (CAD), converter (CVD) and lever arm (LD) domains. To give information about the role of these domains in the myosin head performance, we have examined the effect of three site-directed antibodies to the myosin head on in vitro ATP-dependent actin-myosin sliding and Ca2+-activated contraction of muscle fibers. Antibody 1, attaching to junctional peptide between 50K and 20K heavy chain segments in the CAD, exhibited appreciable effects neither on in vitro actin-myosin sliding nor muscle fiber contraction. Since antibody 1 covers actin-binding sites of the CAD, one interpretation of this result is that rigor actin-myosin linkage is absent or at most a transient intermediate in physiological actin-myosin cycling. Antibody 2, attaching to reactive lysine residue in the CVD, showed a marked inhibitory effect on in vitro actin-myosin sliding without changing actin-activated myosin head (S1) ATPase activity, while it showed no appreciable effect on muscle contraction. Antibody 3, attaching to two peptides of regulatory light chains in the LD, had no significant effect on in vitro actin-myosin sliding, while it reduced force development in muscle fibers without changing MgATPase activity. The above definite differences in the effect of antibodies 2 and 3 between in vitro actin-myosin sliding and muscle contraction can be explained by difference in experimental conditions; in the former, myosin heads are randomly oriented on a glass surface, while in the latter myosin heads are regularly

  10. Definite Differences between In Vitro Actin-Myosin Sliding and Muscle Contraction as Revealed Using Antibodies to Myosin Head

    PubMed Central

    Sugi, Haruo; Chaen, Shigeru; Kobayashi, Takakazu; Abe, Takahiro; Kimura, Kazushige; Saeki, Yasutake; Ohnuki, Yoshiki; Miyakawa, Takuya; Tanokura, Masaru; Sugiura, Seiryo

    2014-01-01

    Muscle contraction results from attachment-detachment cycles between myosin heads extending from myosin filaments and actin filaments. It is generally believed that a myosin head first attaches to actin, undergoes conformational changes to produce force and motion in muscle, and then detaches from actin. Despite extensive studies, the molecular mechanism of myosin head conformational changes still remains to be a matter for debate and speculation. The myosin head consists of catalytic (CAD), converter (CVD) and lever arm (LD) domains. To give information about the role of these domains in the myosin head performance, we have examined the effect of three site-directed antibodies to the myosin head on in vitro ATP-dependent actin-myosin sliding and Ca2+-activated contraction of muscle fibers. Antibody 1, attaching to junctional peptide between 50K and 20K heavy chain segments in the CAD, exhibited appreciable effects neither on in vitro actin-myosin sliding nor muscle fiber contraction. Since antibody 1 covers actin-binding sites of the CAD, one interpretation of this result is that rigor actin-myosin linkage is absent or at most a transient intermediate in physiological actin-myosin cycling. Antibody 2, attaching to reactive lysine residue in the CVD, showed a marked inhibitory effect on in vitro actin-myosin sliding without changing actin-activated myosin head (S1) ATPase activity, while it showed no appreciable effect on muscle contraction. Antibody 3, attaching to two peptides of regulatory light chains in the LD, had no significant effect on in vitro actin-myosin sliding, while it reduced force development in muscle fibers without changing MgATPase activity. The above definite differences in the effect of antibodies 2 and 3 between in vitro actin-myosin sliding and muscle contraction can be explained by difference in experimental conditions; in the former, myosin heads are randomly oriented on a glass surface, while in the latter myosin heads are regularly

  11. A value framework in head and neck cancer care.

    PubMed

    de Souza, Jonas A; Seiwert, Tanguy Y

    2014-01-01

    The care of head and neck squamous cell carcinoma has greatly evolved over the past 30 years. From single modality to a multidisciplinary care, there has also been a concurrent increase in treatment intensity, resulting, at many times, in more zealous regimens that patients must endure. In this article, we apply Porter's value model as a framework to balance survival, toxicities, cost, and trade-offs from a patient's perspective in head and neck cancer. This model defines value as the health outcome per dollar achieved. Domains and outcomes that are important to patients, including not only survival or short-term quality of life, but also functional outcomes, recovery, sustainability of recovery, and the lasting consequences of therapy are included in this framework. Other outcomes that are seldom measured in head and neck cancer, such as work disability and financial toxicities, are also included and further discussed. Within this value model and based on evidence, we further discuss de-escalation of care, intensity-modulated radiation therapy, newer surgical methods, and enhancements in the process of care as potential approaches to add value for patients. Finally, we argue that knowing the patient's preferences is essential in the value discussion, as the attribute that will ultimately provide the most value to the individual patient with head and neck cancer.

  12. Investigation of relationship between social capital and quality of life in female headed families

    PubMed Central

    Rimaz, Shahnaz; Dastoorpoor, Maryam; Vesali, Samira; Saiepour, Narges; Nedjat, Saharnaz; Sadeghi, Masoumeh; Merghati Khoei, Effat

    2015-01-01

    Background: Although most studies on female-headed families focus on women's access to social support, the associations between social capital and quality of life in these families are unclear in many societies (such as Iran). This study aimed to determine the associations between social capital and quality of life in Iranian female headed families. Methods: This cross-sectional study was performed on 152 female-headed households supported by Tehran Municipality, district 9 from April 2011 to July 2012. Convenience sampling was employed. Data were collected using demographic questionnaire, the Iranian version of World Health Organization Quality of Life, and the Word Bank Social Capital. Descriptive and multiple regression methods were used to analyze the data. Results: The mean±SD age of participants was 50.8±13.8 years. Findings revealed that in quality of life, the domains of environment health and social relation received the lowest (9.87 ± 2.41) and the highest (12.61 ±3.43) scores respectively; and with respect to social capital, membership in groups and social trust had the least (19.61 ± 17.11) and the most (51.04 ± 17.37) scores, respectively. The multiple regression model revealed a significant positive association between total score of the quality of life and the total score for the social capital (p< 0.001). Conclusion: Findings suggest that quality of life of female-headed families and social capital domains are strongly related. This means that by improving the social capital, women’s life can also be improved. PMID:26793661

  13. Firing properties of rat lateral mammillary single units: head direction, head pitch, and angular head velocity.

    PubMed

    Stackman, R W; Taube, J S

    1998-11-01

    Many neurons in the rat anterodorsal thalamus (ADN) and postsubiculum (PoS) fire selectively when the rat points its head in a specific direction in the horizontal plane, independent of the animal's location and ongoing behavior. The lateral mammillary nuclei (LMN) are interconnected with both the ADN and PoS and, therefore, are in a pivotal position to influence ADN/PoS neurophysiology. To further understand how the head direction (HD) cell signal is generated, we recorded single neurons from the LMN of freely moving rats. The majority of cells discharged as a function of one of three types of spatial correlates: (1) directional heading, (2) head pitch, or (3) angular head velocity (AHV). LMN HD cells exhibited higher peak firing rates and greater range of directional firing than that of ADN and PoS HD cells. LMN HD cells were modulated by angular head velocity, turning direction, and anticipated the rat's future HD by a greater amount of time (approximately 95 msec) than that previously reported for ADN HD cells (approximately 25 msec). Most head pitch cells discharged when the rostrocaudal axis of the rat's head was orthogonal to the horizontal plane. Head pitch cell firing was independent of the rat's location, directional heading, and its body orientation (i.e., the cell discharged whenever the rat pointed its head up, whether standing on all four limbs or rearing). AHV cells were categorized as fast or slow AHV cells depending on whether their firing rate increased or decreased in proportion to angular head velocity. These data demonstrate that LMN neurons code direction and angular motion of the head in both horizontal and vertical planes and support the hypothesis that the LMN play an important role in processing both egocentric and allocentric spatial information.

  14. Spin valves with spin-engineered domain-biasing scheme

    NASA Astrophysics Data System (ADS)

    Lu, Z. Q.; Pan, G.

    2003-06-01

    Synthetic spin-filter spin valves with spin-engineered biasing scheme "sub/Ta/NiFe/IrMn/NiFe/NOL/Cu1/CoFe/Cu2/CoFe/Ru/CoFe/IrMn/Ta" were developed. In the structure, the orthogonal magnetic configuration for biasing and pinning field was obtained by one-step magnetic annealing process by means of spin flop, which eliminated the need for two antiferromagnetic materials with distinctively different blocking temperatures and two-step magnetic annealing as in conventional exchange biasing scheme. The longitudinal domain biasing of spin valves was achieved by using interlayer coupling field through Cu1 spacer. By adjusting the thickness of the Cu1 layer, the interlayer coupling biasing field can provide domain stabilization and was sufficiently strong to constrain the magnetization in coherent rotation. This can prevent Barkhausen noises associated with magnetization reversal. We report here a proof of concept study of such a domain-biasing scheme, which has its important technological applications in nanoscale spin valve and magnetic tunneling junction read heads and other spintronic devices.

  15. A Professional Development Program to Improve Math Skills among Preschool Children in Head Start

    ERIC Educational Resources Information Center

    Brendefur, Jonathan; Strother, Sam; Thiede, Keith; Lane, Cristianne; Surges-Prokop, Mary Jo

    2013-01-01

    The purpose of this study was to examine the effects on four-year-olds' knowledge of mathematics by introducing professional development and center-based mathematics activities around four mathematical domains to early educators' teaching in Head Start programs. Because of the need to provide necessary mathematical experiences to young children to…

  16. Parallel Solver for Diffuse Optical Tomography on Realistic Head Models With Scattering and Clear Regions.

    PubMed

    Placati, Silvio; Guermandi, Marco; Samore, Andrea; Scarselli, Eleonora Franchi; Guerrieri, Roberto

    2016-09-01

    Diffuse optical tomography is an imaging technique, based on evaluation of how light propagates within the human head to obtain the functional information about the brain. Precision in reconstructing such an optical properties map is highly affected by the accuracy of the light propagation model implemented, which needs to take into account the presence of clear and scattering tissues. We present a numerical solver based on the radiosity-diffusion model, integrating the anatomical information provided by a structural MRI. The solver is designed to run on parallel heterogeneous platforms based on multiple GPUs and CPUs. We demonstrate how the solver provides a 7 times speed-up over an isotropic-scattered parallel Monte Carlo engine based on a radiative transport equation for a domain composed of 2 million voxels, along with a significant improvement in accuracy. The speed-up greatly increases for larger domains, allowing us to compute the light distribution of a full human head ( ≈ 3 million voxels) in 116 s for the platform used.

  17. Comparisons of Computed Mobile Phone Induced SAR in the SAM Phantom to That in Anatomically Correct Models of the Human Head

    PubMed Central

    Beard, Brian B.; Kainz, Wolfgang; Onishi, Teruo; Iyama, Takahiro; Watanabe, Soichi; Fujiwara, Osamu; Wang, Jianqing; Bit-Babik, Giorgi; Faraone, Antonio; Wiart, Joe; Christ, Andreas; Kuster, Niels; Lee, Ae-Kyoung; Kroeze, Hugo; Siegbahn, Martin; Keshvari, Jafar; Abrishamkar, Houman; Simon, Winfried; Manteuffel, Dirk; Nikoloski, Neviana

    2018-01-01

    The specific absorption rates (SAR) determined computationally in the specific anthropomorphic mannequin (SAM) and anatomically correct models of the human head when exposed to a mobile phone model are compared as part of a study organized by IEEE Standards Coordinating Committee 34, SubCommittee 2, and Working Group 2, and carried out by an international task force comprising 14 government, academic, and industrial research institutions. The detailed study protocol defined the computational head and mobile phone models. The participants used different finite-difference time-domain software and independently positioned the mobile phone and head models in accordance with the protocol. The results show that when the pinna SAR is calculated separately from the head SAR, SAM produced a higher SAR in the head than the anatomically correct head models. Also the larger (adult) head produced a statistically significant higher peak SAR for both the 1- and 10-g averages than did the smaller (child) head for all conditions of frequency and position. PMID:29515260

  18. Comparisons of Computed Mobile Phone Induced SAR in the SAM Phantom to That in Anatomically Correct Models of the Human Head.

    PubMed

    Beard, Brian B; Kainz, Wolfgang; Onishi, Teruo; Iyama, Takahiro; Watanabe, Soichi; Fujiwara, Osamu; Wang, Jianqing; Bit-Babik, Giorgi; Faraone, Antonio; Wiart, Joe; Christ, Andreas; Kuster, Niels; Lee, Ae-Kyoung; Kroeze, Hugo; Siegbahn, Martin; Keshvari, Jafar; Abrishamkar, Houman; Simon, Winfried; Manteuffel, Dirk; Nikoloski, Neviana

    2006-06-05

    The specific absorption rates (SAR) determined computationally in the specific anthropomorphic mannequin (SAM) and anatomically correct models of the human head when exposed to a mobile phone model are compared as part of a study organized by IEEE Standards Coordinating Committee 34, SubCommittee 2, and Working Group 2, and carried out by an international task force comprising 14 government, academic, and industrial research institutions. The detailed study protocol defined the computational head and mobile phone models. The participants used different finite-difference time-domain software and independently positioned the mobile phone and head models in accordance with the protocol. The results show that when the pinna SAR is calculated separately from the head SAR, SAM produced a higher SAR in the head than the anatomically correct head models. Also the larger (adult) head produced a statistically significant higher peak SAR for both the 1- and 10-g averages than did the smaller (child) head for all conditions of frequency and position.

  19. Head circumference

    MedlinePlus

    ... a child's head circumference. Normal ranges for a child's sex and age (weeks, months), based on values that experts have obtained for normal growth rates of infants' and children's heads. Measurement of the head circumference is an ...

  20. Associations between neighbourhood support and financial burden with unmet needs of head and neck cancer survivors.

    PubMed

    O'Brien, Katie M; Timmons, Aileen; Butow, Phyllis; Gooberman-Hill, Rachael; O'Sullivan, Eleanor; Balfe, Myles; Sharp, Linda

    2017-02-01

    To assess the unmet needs of head and neck cancer survivors and investigate associated factors. In particular, to explore whether social support (family/friends and neighbours) and financial burden are associated with unmet needs of head and neck cancer (HNC) survivors. This was a cross-sectional study of HNC survivors, with 583 respondents included in the analysis. Information was collected on unmet supportive care needs as measured by the Supportive Care Needs Survey (SCNS-SF34). Poisson regression with robust standard errors was used to examine factors associated with having one or more needs in each of the five domains (physical; psychological; sexuality; patient care and support; and health system and information). The mean age of respondents was 62.9years (standard deviation 11.3years) and one third of respondents were female. The top ten unmet needs was composed exclusively of items from the physical and psychological domains. Financial strain due to cancer and finding it difficult to obtain practical help from a neighbour were both associated with unmet needs in each of the five domains, in the adjusted analyses. Whilst in each domain, a minority of respondents have unmet needs, approximately half of respondents reported at least one unmet need, with the commonest unmet needs in the psychological domain. Providing services to people with these needs should be a priority for healthcare providers. We suggest that studies, which identify risk factors for unmet needs, could be used to develop screening tools or aid in the targeting of support. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Clinical predictors of quality of life in patients with head and neck cancer.

    PubMed

    Terrell, Jeffrey E; Ronis, David L; Fowler, Karen E; Bradford, Carol R; Chepeha, Douglas B; Prince, Mark E; Teknos, Theodoros N; Wolf, Gregory T; Duffy, Sonia A

    2004-04-01

    To identify clinical predictors of quality of life (QoL) in a head and neck cancer patient population. A convenience sample of 570 patients with upper aerodigestive tract cancers were surveyed at a tertiary care oncology clinic and Veterans Affairs otolaryngology clinic. A self-administered health survey was constructed to collect demographic, health, smoking, alcohol, depression symptom, and QoL information. Tumor site and tumor stage, clinical, and treatment data were abstracted from the patient medical records. Quality of life was assessed using the Medical Outcomes Study Short-Form 36-Item Health Survey (SF-36) and the Head and Neck QoL (HNQoL) instrument. Of the 570 eligible respondents, the presence of a feeding tube had the most negative impact on QoL, with significant decrements in 6 of the 8 SF-36 scales and all 4 HNQoL scales (P<.01). In descending order of severity, medical comorbid conditions, presence of a tracheotomy tube, chemotherapy, and neck dissection were also associated with significant (P<.05) decrements in QoL domains. Patients who took the survey more than 1 year after diagnosis had improved QoL in 7 of 12 domains. Hospital site, age, education level, sex, race, and marital status were also significant predictors of QoL. There are at least 13 demographic and clinical characteristics that are significant predictors of QoL in patients with head and neck cancer, which should be considered when treating patients and conducting QoL studies in the future.

  2. Feasibility and implementation of a literature information management system for human papillomavirus in head and neck cancers with imaging.

    PubMed

    Wu, Dee H; Matthiesen, Chance L; Alleman, Anthony M; Fournier, Aaron L; Gunter, Tyler C

    2014-01-01

    This work examines the feasibility and implementation of information service-orientated architecture (ISOA) on an emergent literature domain of human papillomavirus, head and neck cancer, and imaging. From this work, we examine the impact of cancer informatics and generate a full set of summarizing clinical pearls. Additionally, we describe how such an ISOA creates potential benefits in informatics education, enhancing utility for creating enduring digital content in this clinical domain.

  3. The Globular Tail Domain of Myosin-5a Functions as a Dimer in Regulating the Motor Activity.

    PubMed

    Zhang, Wen-Bo; Yao, Lin-Lin; Li, Xiang-Dong

    2016-06-24

    Myosin-5a contains two heavy chains, which are dimerized via the coiled-coil regions. Thus, myosin-5a comprises two heads and two globular tail domains (GTDs). The GTD is the inhibitory domain that binds to the head and inhibits its motor function. Although the two-headed structure is essential for the processive movement of myosin-5a along actin filaments, little is known about the role of GTD dimerization. Here, we investigated the effect of GTD dimerization on its inhibitory activity. We found that the potent inhibitory activity of the GTD is dependent on its dimerization by the preceding coiled-coil regions, indicating synergistic interactions between the two GTDs and the two heads of myosin-5a. Moreover, we found that alanine mutations of the two conserved basic residues at N-terminal extension of the GTD not only weaken the inhibitory activity of the GTD but also enhance the activation of myosin-5a by its cargo-binding protein melanophilin (Mlph). These results are consistent with the GTD forming a head to head dimer, in which the N-terminal extension of the GTD interacts with the Mlph-binding site in the counterpart GTD. The Mlph-binding site at the GTD-GTD interface must be exposed prior to the binding of Mlph. We therefore propose that the inhibited Myo5a is equilibrated between the folded state, in which the Mlph-binding site is buried, and the preactivated state, in which the Mlph-binding site is exposed, and that Mlph is able to bind to the Myo5a in preactivated state and activates its motor function. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Influence of corneal power on circumpapillary retinal nerve fiber layer and optic nerve head measurements by spectral-domain optical coherence tomography.

    PubMed

    Hirasawa, Kazunori; Shoji, Nobuyuki

    2017-01-01

    To evaluate the influence of corneal power on circumpapillary retinal nerve fiber layer (cpRNFL) and optic nerve head (ONH) measurements by spectral-domain optical coherence tomography (SD-OCT). Twenty-five eyes of 25 healthy participants (mean age 23.6±3.6y) were imaged by SD-OCT using horizontal raster scans. Disposable soft contact lenses of different powers (from -11 to +5 diopters including 0 diopter) were worn to induce 2-diopter changes in corneal power. Differences in the cpRNFL and ONH measurements per diopter of change in corneal power were analyzed. As corneal power increased by 1 diopter, total and quadrant cpRNFL thicknesses, except for the nasal sector, decreased by --0.19 to -0.32 µm ( P <0.01). Furthermore, the disc, cup, and rim areas decreased by -0.017, -0.007, and -0.015 mm 2 , respectively ( P <0.001); the cup and rim volumes decreased by -0.0013 and -0.006 mm 3 , respectively ( P <0.01); and the vertical and horizontal disc diameters decreased by -0.006 and -0.007 mm, respectively ( P <0.001). For more precise OCT imaging, the ocular magnification should be corrected by considering both the axial length and corneal power. However, the effect of corneal power changes on cpRNFL thickness and ONH topography are small when compare with those of the axial length.

  5. Head lice.

    PubMed

    Devore, Cynthia D; Schutze, Gordon E

    2015-05-01

    Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2010 clinical report on head lice was published by the American Academy of Pediatrics, newer medications have been approved for the treatment of head lice. This revised clinical report clarifies current diagnosis and treatment protocols and provides guidance for the management of children with head lice in the school setting. Copyright © 2015 by the American Academy of Pediatrics.

  6. Regulation of adhesion behavior of murine macrophage using supported lipid membranes displaying tunable mannose domains

    NASA Astrophysics Data System (ADS)

    Kaindl, T.; Oelke, J.; Pasc, A.; Kaufmann, S.; Konovalov, O. V.; Funari, S. S.; Engel, U.; Wixforth, A.; Tanaka, M.

    2010-07-01

    Highly uniform, strongly correlated domains of synthetically designed lipids can be incorporated into supported lipid membranes. The systematic characterization of membranes displaying a variety of domains revealed that the equilibrium size of domains significantly depends on the length of fluorocarbon chains, which can be quantitatively interpreted within the framework of an equivalent dipole model. A mono-dispersive, narrow size distribution of the domains enables us to treat the inter-domain correlations as two-dimensional colloidal crystallization and calculate the potentials of mean force. The obtained results demonstrated that both size and inter-domain correlation can precisely be controlled by the molecular structures. By coupling α-D-mannose to lipid head groups, we studied the adhesion behavior of the murine macrophage (J774A.1) on supported membranes. Specific adhesion and spreading of macrophages showed a clear dependence on the density of functional lipids. The obtained results suggest that such synthetic lipid domains can be used as a defined platform to study how cells sense the size and distribution of functional molecules during adhesion and spreading.

  7. Rate and extent of pH decline affect proteolysis of cytoskeletal proteins and water-holding capacity in pork.

    PubMed

    Bee, Giuseppe; Anderson, Abbey L; Lonergan, Steven M; Huff-Lonergan, Elisabeth

    2007-06-01

    The objective of this study was to determine the extent to which early postmortem (PM) pH decline influences proteolysis of the intermediate filament protein desmin, the costameric proteins vinculin and talin and autolysis of μ-calpain in the longissimus muscle (LM) of pigs from two genetic lines. Based on the LM 3h pH (H=3h pH of LM>6.0; L=3h pH of LM pH<5.7) PM, 10 carcasses per line and pH group were selected. The average 3h pH within pH group was 6.23 (H) and 5.44 (L). The LM samples were collected 24, 48, 72, and 120h PM and percent drip loss was measured after 1, 2, and 4d of storage. Samples collected at 24, 48, 72, and 120h PM were used to monitor desmin, vinculin, and talin degradation and samples collected at 24h PM were used to determine the extent of μ-calpain autolysis by immunoblotting. Higher (P<0.01) pH values at 45min, 6h, and 24h PM and lower (P<0.01) drip losses after 1, 2, and 4d of storage were recorded in the H-compared to the L-group. Abundance of the 76kDa μ-calpain autolysis product was greater (P<0.01), proteolysis of talin at all measured time points and proteolysis of desmin after 24 and 48h PM was greater (P⩽0.03) in the H-group than in the L-group. The current findings indicate activation rate of μ-calpain may be associated with proteolysis of desmin and talin and could play a role in the development of drip loss. The rate of early PM pH decline can partly explain the variation of desmin and talin degradation by affecting the activation of μ-calpain.

  8. Usability study of the EduMod eLearning Program for contouring nodal stations of the head and neck.

    PubMed

    Deraniyagala, Rohan; Amdur, Robert J; Boyer, Arthur L; Kaylor, Scott

    2015-01-01

    A major strategy for improving radiation oncology education and competence evaluation is to develop eLearning programs that reproduce the real work environment. A valuable measure of the quality of an eLearning program is "usability," which is a multidimensional endpoint defined from the end user's perspective. The gold standard for measuring usability is the Software Usability Measurement Inventory (SUMI). The purpose of this study is to use the SUMI to measure usability of an eLearning course that uses innovative software to teach and test contouring of nodal stations of the head and neck. This is a prospective institutional review board-approved study in which all participants gave written informed consent. The study population was radiation oncology residents from 8 different programs across the United States. The subjects had to pass all sections of the same 2 eLearning modules and then complete the SUMI usability evaluation instrument. We reached the accrual goal of 25 participants. Usability results for the EduMod eLearning course, "Nodal Stations of the Head and Neck," were compared with a large database of scores of other major software programs. Results were evaluated in 5 domains: Affect, Helpfulness, Control, Learnability, and Global Usability. In all 5 domains, usability scores for the study modules were higher than the database mean and statistically superior in 4 domains. This is the first study to evaluate usability of an eLearning program related to radiation oncology. Usability of 2 representative modules related to contouring nodal stations of the head and neck was highly favorable, with scores that were superior to the industry standard in multiple domains. These results support the continued development of this type of eLearning program for teaching and testing radiation oncology technical skills. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  9. Neck Strength Imbalance Correlates With Increased Head Acceleration in Soccer Heading

    PubMed Central

    Dezman, Zachary D.W.; Ledet, Eric H.; Kerr, Hamish A.

    2013-01-01

    Background: Soccer heading is using the head to directly contact the ball, often to advance the ball down the field or score. It is a skill fundamental to the game, yet it has come under scrutiny. Repeated subclinical effects of heading may compound over time, resulting in neurologic deficits. Greater head accelerations are linked to brain injury. Developing an understanding of how the neck muscles help stabilize and reduce head acceleration during impact may help prevent brain injury. Hypothesis: Neck strength imbalance correlates to increasing head acceleration during impact while heading a soccer ball. Study Design: Observational laboratory investigation. Methods: Sixteen Division I and II collegiate soccer players headed a ball in a controlled indoor laboratory setting while player motions were recorded by a 14-camera Vicon MX motion capture system. Neck flexor and extensor strength of each player was measured using a spring-type clinical dynamometer. Results: Players were served soccer balls by hand at a mean velocity of 4.29 m/s (±0.74 m/s). Players returned the ball to the server using a heading maneuver at a mean velocity of 5.48 m/s (±1.18 m/s). Mean neck strength difference was positively correlated with angular head acceleration (rho = 0.497; P = 0.05), with a trend toward significance for linear head acceleration (rho = 0.485; P = 0.057). Conclusion: This study suggests that symmetrical strength in neck flexors and extensors reduces head acceleration experienced during low-velocity heading in experienced collegiate players. Clinical Relevance: Balanced neck strength may reduce head acceleration cumulative subclinical injury. Since neck strength is a measureable and amenable strength training intervention, this may represent a modifiable intrinsic risk factor for injury. PMID:24459547

  10. Gender differences in head-neck segment dynamic stabilization during head acceleration.

    PubMed

    Tierney, Ryan T; Sitler, Michael R; Swanik, C Buz; Swanik, Kathleen A; Higgins, Michael; Torg, Joseph

    2005-02-01

    Recent epidemiological research has revealed that gender differences exist in concussion incidence but no study has investigated why females may be at greater risk of concussion. Our purpose was to determine whether gender differences existed in head-neck segment kinematic and neuromuscular control variables responses to an external force application with and without neck muscle preactivation. Forty (20 females and 20 males) physically active volunteers participated in the study. The independent variables were gender, force application (known vs unknown), and force direction (forced flexion vs forced extension). The dependent variables were kinematic and EMG variables, head-neck segment stiffness, and head-neck segment flexor and extensor isometric strength. Statistical analyses consisted of multiple multivariate and univariate analyses of variance, follow-up univariate analyses of variance, and t-tests (P < or = 0.05). Gender differences existed in head-neck segment dynamic stabilization during head angular acceleration. Females exhibited significantly greater head-neck segment peak angular acceleration (50%) and displacement (39%) than males despite initiating muscle activity significantly earlier (SCM only) and using a greater percentage of their maximum head-neck segment muscle activity (79% peak activity and 117% muscle activity area). The head-neck segment angular acceleration differences may be because females exhibited significantly less isometric strength (49%), neck girth (30%), and head mass (43%), resulting in lower levels of head-neck segment stiffness (29%). For our subject demographic, the results revealed gender differences in head-neck segment dynamic stabilization during head acceleration in response to an external force application. Females exhibited significantly greater head-neck segment peak angular acceleration and displacement than males despite initiating muscle activity earlier (SCM only) and using a greater percentage of their maximum

  11. Structural insights into SAM domain-mediated tankyrase oligomerization.

    PubMed

    DaRosa, Paul A; Ovchinnikov, Sergey; Xu, Wenqing; Klevit, Rachel E

    2016-09-01

    Tankyrase 1 (TNKS1; a.k.a. ARTD5) and tankyrase 2 (TNKS2; a.k.a ARTD6) are highly homologous poly(ADP-ribose) polymerases (PARPs) that function in a wide variety of cellular processes including Wnt signaling, Src signaling, Akt signaling, Glut4 vesicle translocation, telomere length regulation, and centriole and spindle pole maturation. Tankyrase proteins include a sterile alpha motif (SAM) domain that undergoes oligomerization in vitro and in vivo. However, the SAM domains of TNKS1 and TNKS2 have not been structurally characterized and the mode of oligomerization is not yet defined. Here we model the SAM domain-mediated oligomerization of tankyrase. The structural model, supported by mutagenesis and NMR analysis, demonstrates a helical, homotypic head-to-tail polymer that facilitates TNKS self-association. Furthermore, we show that TNKS1 and TNKS2 can form (TNKS1 SAM-TNKS2 SAM) hetero-oligomeric structures mediated by their SAM domains. Though wild-type tankyrase proteins have very low solubility, model-based mutations of the SAM oligomerization interface residues allowed us to obtain soluble TNKS proteins. These structural insights will be invaluable for the functional and biophysical characterization of TNKS1/2, including the role of TNKS oligomerization in protein poly(ADP-ribosyl)ation (PARylation) and PARylation-dependent ubiquitylation. © 2016 The Protein Society.

  12. Control of Smc Coiled Coil Architecture by the ATPase Heads Facilitates Targeting to Chromosomal ParB/parS and Release onto Flanking DNA

    PubMed Central

    Minnen, Anita; Bürmann, Frank; Wilhelm, Larissa; Anchimiuk, Anna; Diebold-Durand, Marie-Laure; Gruber, Stephan

    2016-01-01

    Summary Smc/ScpAB promotes chromosome segregation in prokaryotes, presumably by compacting and resolving nascent sister chromosomes. The underlying mechanisms, however, are poorly understood. Here, we investigate the role of the Smc ATPase activity in the recruitment of Smc/ScpAB to the Bacillus subtilis chromosome. We demonstrate that targeting of Smc/ScpAB to ParB/parS loading sites is strictly dependent on engagement of Smc head domains and relies on an open organization of the Smc coiled coils. We find that dimerization of the Smc hinge domain stabilizes closed Smc rods and hinders head engagement as well as chromosomal targeting. Conversely, the ScpAB sub-complex promotes head engagement and Smc rod opening and thereby facilitates recruitment of Smc to parS sites. Upon ATP hydrolysis, Smc/ScpAB is released from loading sites and relocates within the chromosome—presumably through translocation along DNA double helices. Our findings define an intermediate state in the process of chromosome organization by Smc. PMID:26904953

  13. Convergent Evolution of Head Crests in Two Domesticated Columbids Is Associated with Different Missense Mutations in EphB2.

    PubMed

    Vickrey, Anna I; Domyan, Eric T; Horvath, Martin P; Shapiro, Michael D

    2015-10-01

    Head crests are important display structures in wild bird species and are also common in domesticated lineages. Many breeds of domestic rock pigeon (Columba livia) have crests of reversed occipital feathers, and this recessive trait is associated with a nonsynonymous coding mutation in the intracellular kinase domain of EphB2 (Ephrin receptor B2). The domestic ringneck dove (Streptopelia risoria) also has a recessive crested morph with reversed occipital feathers, and interspecific crosses between crested doves and pigeons produce crested offspring, suggesting a similar genetic basis for this trait in both species. We therefore investigated EphB2 as a candidate for the head crest phenotype of ringneck doves and identified a nonsynonymous coding mutation in the intracellular kinase domain that is significantly associated with the crested morph. This mutation is over 100 amino acid positions away from the crest mutation found in rock pigeons, yet both mutations are predicted to negatively affect the function of ATP-binding pocket. Furthermore, bacterial toxicity assays suggest that "crest" mutations in both species severely impact kinase activity. We conclude that head crests are associated with different mutations in the same functional domain of the same gene in two different columbid species, thereby representing striking evolutionary convergence in morphology and molecules. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Head Lice (For Parents)

    MedlinePlus

    ... Videos for Educators Search English Español First Aid: Head Lice KidsHealth / For Parents / First Aid: Head Lice Print A head louse is a tiny, wingless ... Prevention! You can help protect your kids from head lice by teaching them to: avoid head-to-head ...

  15. An evaluation of flight path formats head-up and head-down

    NASA Technical Reports Server (NTRS)

    Sexton, George A.; Moody, Laura E.; Evans, Joanne; Williams, Kenneth E.

    1988-01-01

    Flight path primary flight display formats were incorporated on head-up and head-down electronic displays and integrated into an Advanced Concepts Flight Simulator. Objective and subjective data were collected while ten airline pilots evaluated the formats by flying an approach and landing task under various ceiling, visibility and wind conditions. Deviations from referenced/commanded airspeed, horizontal track, vertical track and touchdown point were smaller using the head-up display (HUD) format than the head-down display (HDD) format, but not significantly smaller. Subjectively, the pilots overwhelmingly preferred (1) flight path formats over attitude formats used in current aircraft, and (2) the head-up presentation over the head-down, primarily because it eliminated the head-down to head-up transition during low visibility landing approaches. This report describes the simulator, the flight displays, the format evaluation, and the results of the objective and subjective data.

  16. Development of the scanning system to detect the concentration of oxy- and deoxy-hemoglobin by tracking the head

    NASA Astrophysics Data System (ADS)

    Ko, Woo Seok; Darwish, Naser; Gratton, Enrico; Kim, Soo Hyun

    2005-04-01

    We measure the concentration of oxy-, deoxy- and total hemoglobin by using the frequency-domain, near-infrared spectroscopy(NIRS) scanner. It is a non-invasive instrument that can provide real-time measurements of the changes in concentration. It can provide a diagnostic tool for the study of the brain in infants and children. However, it is difficult to apply it to the baby's head because of the contact of the probe on the soft baby's head. Therefore, we suggest the NIRS scanning system that can track the baby' head movement and detect NIRS parameters on the same position of the head. This system has three key components. The vision system performs the pattern matching for tracking the head by using the normalized cross correlation method with the target as a cross-line on the head during the diagnostic experiment. We can use the change of the position of the baby's head to re-target the light by the scanning system that uses four laser sources, a wavelength selector, and an x-y scanner. The detector system analyzes the resulting signal from the head using the diffusion model. Therefore, NIRS scanning system can provide a diagnostic tool to measure the changes of the NIRS parameters for the study of the baby's brain.

  17. Molecular insights into the binding of phosphoinositides to the TH domain region of TIPE proteins.

    PubMed

    Antony, Priya; Baby, Bincy; Vijayan, Ranjit

    2016-11-01

    Phosphatidylinositols and their phosphorylated derivatives, phosphoinositides, play a central role in regulating diverse cellular functions. These phospholipids have been shown to interact with the hydrophobic TH domain of the tumor necrosis factor (TNF)-α-induced protein 8 (TIPE) family of proteins. However, the precise mechanism of interaction of these lipids is unclear. Here we report the binding mode and interactions of these phospholipids in the TH domain, as elucidated using molecular docking and simulations. Results indicate that phosphoinositides bind to the TH domain in a similar way by inserting their lipid tails in the hydrophobic cavity. The exposed head group is stabilized by interactions with critical positively charged residues on the surface of these proteins. Further MD simulations confirmed the dynamic stability of these lipids in the TH domain. This computational analysis thus provides insight into the binding mode of phospholipids in the TH domain of the TIPE family of proteins. Graphical abstract A phosphoinositide (phosphatidylinositol 4-phosphate; PtdIns4P) docked to TIPE2.

  18. Domain wall structure and interactions in 50 nm wide Cobalt nanowires

    NASA Astrophysics Data System (ADS)

    Tu, Kun-Hua; Ojha, Shuchi; Ross, Caroline A.

    2018-05-01

    Arrays of cobalt nanowires with widths of 50 nm, thickness of 5 and 20 nm and periodicity of 70 nm were fabricated by pattern transfer from a self-assembled block copolymer film. Transverse domain walls (DWs) were imaged by magnetic force microscopy, indicating repulsive interactions between DWs of the same sign in the 20 nm thick wires. Micromagnetic simulations were used to identify the interactions in the six distinct cases of a pair of transverse DWs in adjacent wires, considering all the possible combinations of head-to-head and tail-to-tail DWs and the orientation of the core magnetization. The boundary between repulsive and attractive DW interactions is mapped out for wires as a function of thickness, width and interwire spacing.

  19. Subdivision of arthropod cap-n-collar expression domains is restricted to Mandibulata

    PubMed Central

    2014-01-01

    Background The monophyly of Mandibulata - the division of arthropods uniting pancrustaceans and myriapods - is consistent with several morphological characters, such as the presence of sensory appendages called antennae and the eponymous biting appendage, the mandible. Functional studies have demonstrated that the patterning of the mandible requires the activity of the Hox gene Deformed and the transcription factor cap-n-collar (cnc) in at least two holometabolous insects: the fruit fly Drosophila melanogaster and the beetle Tribolium castaneum. Expression patterns of cnc from two non-holometabolous insects and a millipede have suggested conservation of the labral and mandibular domains within Mandibulata. However, the activity of cnc is unknown in crustaceans and chelicerates, precluding understanding of a complete scenario for the evolution of patterning of this appendage within arthropods. To redress these lacunae, here we investigate the gene expression of the ortholog of cnc in Parhyale hawaiensis, a malacostracan crustacean, and two chelicerates: the harvestman Phalangium opilio, and the scorpion Centruroides sculpturatus. Results In the crustacean P. hawaiensis, the segmental expression of Ph-cnc is the same as that reported previously in hexapods and myriapods, with two distinct head domains in the labrum and the mandibular segment. In contrast, Po-cnc and Cs-cnc expression is not enriched in the labrum of either chelicerate, but instead is expressed at comparable levels in all appendages. In further contrast to mandibulate orthologs, the expression domain of Po-cnc posterior to the labrum is not confined within the expression domain of Po-Dfd. Conclusions Expression data from two chelicerate outgroup taxa suggest that the signature two-domain head expression pattern of cnc evolved at the base of Mandibulata. The observation of the archetypal labral and mandibular segment domains in a crustacean exemplar supports the synapomorphic nature of mandibulate cnc

  20. Oxime ether lipids containing hydroxylated head groups are more superior siRNA delivery agents than their nonhydroxylated counterparts.

    PubMed

    Gupta, Kshitij; Mattingly, Stephanie J; Knipp, Ralph J; Afonin, Kirill A; Viard, Mathias; Bergman, Joseph T; Stepler, Marissa; Nantz, Michael H; Puri, Anu; Shapiro, Bruce A

    2015-01-01

    To evaluate the structure-activity relationship of oxime ether lipids (OELs) containing modifications in the hydrophobic domains (chain length, degree of unsaturation) and hydrophilic head groups (polar domain hydroxyl groups) toward complex formation with siRNA molecules and siRNA delivery efficiency of resulting complexes to a human breast cancer cell line (MDA-MB-231). Ability of lipoplex formation between oxime ether lipids with nucleic acids were examined using biophysical techniques. The potential of OELs to deliver nucleic acids and silence green fluorescent protein (GFP) gene was analyzed using MDA-MB-231 and MDA-MB-231/GFP cells, respectively. Introduction of hydroxyl groups to the polar domain of the OELs and unsaturation into the hydrophobic domain favor higher transfection and gene silencing in a cell culture system.

  1. Putative suppressing effect of IgG Fc-conjugated haemagglutinin (HA) stalk of influenza virus H7N9 on the neutralizing immunogenicity of Fc-conjugated HA head: implication for rational design of HA-based influenza vaccines.

    PubMed

    He, B; Xia, S; Yu, F; Fu, Y; Li, W; Wang, Q; Lu, L; Jiang, S

    2016-02-01

    The emergence of influenza A H7N9 in infection has posed a great threat to public health globally. Poor immunogenicity of H7N9 haemagglutinin (HA) is a major obstacle to the development of an effective H7N9 vaccine. Here, we found that the vaccine containing the H7HA head conjugated with IgG Fc (Hd-Fc) induced strong neutralizing antibody responses and protection against H7N9 infection, whilst the Fc-conjugated H7HA stalk (St-Fc)-based vaccine could not induce neutralizing antibodies, although the St-Fc-immunized mice were partially protected. The vaccines containing the full-length extracellular domain of HA conjugated with Fc and the mixture of Hd-Fc plus St-Fc induced significantly lower neutralizing antibody and haemagglutination inhibition titres than the Hd-Fc-based vaccine. These results suggest that the St-Fc may have inhibitory effects on the neutralizing immunogenicity of Hd-Fc. Therefore, the neutralizing domain(s), such as the receptor-binding domain, in the HA head should be kept and the non-neutralizing domain(s) in the HA stalk with the ability to potentially suppress the neutralizing immunogenicity of HA head should be removed from Fc-conjugated HA-based influenza vaccines to increase the neutralizing antibody response.

  2. Quality of life in head and neck cancer survivors: a cross-sectional survey.

    PubMed

    Chaukar, Devendra A; Walvekar, Rohan R; Das, Ashok K; Deshpande, Mandar S; Pai, Prathamesh S; Chaturvedi, Pankaj; Kakade, Anagha; D'Cruz, Anil K

    2009-01-01

    Head and neck cancer (HNC) survivors have substantial psychological distress in addition to treatment-related side effects. This study examines the long-term quality of life (QOL) of HNC survivors in a busy tertiary care center. A prospective, cross-sectional survey was conducted studying 212 HNC survivors 1 year after completion of their treatment at a tertiary cancer center. Quality of life assessments were performed using the 2 standardized health-related QOL questionnaires: The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 and The Quality of Life Questionnaire Head and Neck Cancer Module. The overall global QOL rating for the study cohort was satisfactory. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 scores showed that the domains where most patients faired poorly included financial difficulties (54%), appetite loss (36%), fatigue (33%), and cough (30%). The Quality of Life Questionnaire Head and Neck Cancer Module scale identified the domains with poor scores to be dry mouth (64%), dental problems (42%), sticky saliva (40%), cough (39%), and problems with mouth opening (32%). Patients with early-stage tumors and those treated with surgery alone had significantly better QOL scores when compared with advanced stage tumors and patients receiving either radiation alone or multimodality treatment, respectively. Quality of life questionnaires provide a medium for patients to effectively communicate with their physician in a busy tertiary care facility and provide an insight into the physical, psychological, and social problems affecting our patients which can then direct future interventions.

  3. Three-dimensional digital mapping of the optic nerve head cupping in glaucoma

    NASA Astrophysics Data System (ADS)

    Mitra, Sunanda; Ramirez, Manuel; Morales, Jose

    1992-08-01

    Visualization of the optic nerve head cupping is clinically achieved by stereoscopic viewing of a fundus image pair of the suspected eye. A novel algorithm for three-dimensional digital surface representation of the optic nerve head, using fusion of stereo depth map with a linearly stretched intensity image of a stereo fundus image pair, is presented. Prior to depth map acquisition, a number of preprocessing tasks including feature extraction, registration by cepstral analysis, and correction for intensity variations are performed. The depth map is obtained by using a coarse to fine strategy for obtaining disparities between corresponding areas. The required matching techniques to obtain the translational differences in every step, uses cepstral analysis and correlation-like scanning technique in the spatial domain for the finest details. The quantitative and precise representation of the optic nerve head surface topography following this algorithm is not computationally intensive and should provide more useful information than just qualitative stereoscopic viewing of the fundus as one of the diagnostic criteria for diagnosis of glaucoma.

  4. Bottom head assembly

    DOEpatents

    Fife, A.B.

    1998-09-01

    A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs.

  5. The Myosin IXb Motor Activity Targets the Myosin IXb RhoGAP Domain as Cargo to Sites of Actin Polymerization

    PubMed Central

    van den Boom, Frank; Düssmann, Heiko; Uhlenbrock, Katharina; Abouhamed, Marouan

    2007-01-01

    Myosin IXb (Myo9b) is a single-headed processive myosin that exhibits Rho GTPase-activating protein (RhoGAP) activity in its tail region. Using live cell imaging, we determined that Myo9b is recruited to extending lamellipodia, ruffles, and filopodia, the regions of active actin polymerization. A functional motor domain was both necessary and sufficient for targeting Myo9b to these regions. The head domains of class IX myosins comprise a large insertion in loop2. Deletion of the large Myo9b head loop 2 insertion abrogated the enrichment in extending lamellipodia and ruffles, but enhanced significantly the enrichment at the tips of filopodia and retraction fibers. The enrichment in the tips of filopodia and retraction fibers depended on four lysine residues C-terminal to the loop 2 insertion and the tail region. Fluorescence recovery after photobleaching and photoactivation experiments in lamellipodia revealed that the dynamics of Myo9b was comparable to that of actin. The exchange rates depended on the Myo9b motor region and motor activity, and they were also dependent on the turnover of F-actin. These results demonstrate that Myo9b functions as a motorized RhoGAP molecule in regions of actin polymerization and identify Myo9b head sequences important for in vivo motor properties. PMID:17314409

  6. Reduced head-neck offset in nontraumatic osteonecrosis of the femoral head.

    PubMed

    Fraitzl, Christian R; Kappe, Thomas; Brugger, Annina; Billich, Christian; Reichel, Heiko

    2013-08-01

    Risk factors for nontraumatic osteonecrosis of the femoral head have in common that they trigger intravascular coagulation and thus lead to devascularization of the femoral head. In part of the patients, however, no risk factors seem to be evident. Mechanical reasons contributing to nontraumatic osteonecrosis have not been discussed so far. We hypothesized that recurrent traumatization of the vessels supplying the femoral head by a cam-type mechanism as in femoroacetabular impingement could add to intravascular coagulation. We, therefore, asked whether structural abnormalities at the femoral head-neck junction indicative of such a mechanism could be observed in radiographs of patients with osteonecrosis of the femoral head. The preoperative anteroposterior and lateral radiographs of 77 patients who underwent surgery because of osteonecrosis of the femoral head were retrospectively screened for a reduced head-neck offset by measuring the α-angle. For comparison, the α-angle was measured on anteroposterior and lateral radiographs of 339 control subjects without evident underlying hip pathology. The mean α-angle was 62.8° (SD 18.7°) for anteroposterior and 67.6° (SD 13.2°) for lateral radiographs in patients with nontraumatic osteonecrosis of the femoral head, whereas in control subjects, the mean α-angle was 47.2° (SD 9.6°) (p < 0.0001) and 47.6° (SD 10.3°) (p < 0.0001), respectively. A reduced head-neck offset in patients with nontraumatic osteonecrosis of the femoral head may act as a mechanical (co-)factor in developing osteonecrosis of the femoral head.

  7. Functional outcomes from a head-to-head, randomized, double-blind trial of lisdexamfetamine dimesylate and atomoxetine in children and adolescents with attention-deficit/hyperactivity disorder and an inadequate response to methylphenidate.

    PubMed

    Nagy, Peter; Häge, Alexander; Coghill, David R; Caballero, Beatriz; Adeyi, Ben; Anderson, Colleen S; Sikirica, Vanja; Cardo, Esther

    2016-02-01

    Attention-deficit/hyperactivity disorder (ADHD) is associated with functional impairments in multiple domains of patients' lives. A secondary objective of this randomized, active-controlled, head-to-head, double-blind, dose-optimized clinical trial was to compare the effects of lisdexamfetamine dimesylate (LDX) and atomoxetine (ATX) on functional impairment in children and adolescents with ADHD. Patients aged 6-17 years with an ADHD Rating Scale IV total score ≥ 28 and an inadequate response to methylphenidate treatment (judged by investigators) were randomized (1:1) to once-daily LDX or ATX for 9 weeks. Parents/guardians completed the Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P) at baseline and at week 9 or early termination. p values were nominal and not corrected for multiple comparisons. Of 267 randomized patients, 200 completed the study (LDX 99, ATX 101). At baseline, mean WFIRS-P total score in the LDX group was 0.95 [standard deviation (SD) 0.474; 95% confidence interval (CI) 0.87, 1.03] and in the ATX group was 0.91 (0.513; 0.82, 1.00). Scores in all WFIRS-P domains improved from baseline to endpoint in both groups, with least-squares mean changes in total score of -0.35 (95% CI -0.42, -0.29) for LDX and -0.27 (-0.33, -0.20) for ATX. The difference between LDX and ATX was statistically significant (p < 0.05) for the Learning and School (effect size of LDX vs ATX, 0.43) and Social Activities (0.34) domains and for total score (0.27). Both treatments reduced functional impairment in children and adolescents with ADHD; LDX was statistically significantly more effective than ATX in two of six domains and in total score.

  8. Cingulin Contains Globular and Coiled-Coil Domains and Interacts with Zo-1, Zo-2, Zo-3, and Myosin

    PubMed Central

    Cordenonsi, Michelangelo; D'Atri, Fabio; Hammar, Eva; Parry, David A.D.; Kendrick-Jones, John; Shore, David; Citi, Sandra

    1999-01-01

    We characterized the sequence and protein interactions of cingulin, an M r 140–160-kD phosphoprotein localized on the cytoplasmic surface of epithelial tight junctions (TJ). The derived amino acid sequence of a full-length Xenopus laevis cingulin cDNA shows globular head (residues 1–439) and tail (1,326–1,368) domains and a central α-helical rod domain (440–1,325). Sequence analysis, electron microscopy, and pull-down assays indicate that the cingulin rod is responsible for the formation of coiled-coil parallel dimers, which can further aggregate through intermolecular interactions. Pull-down assays from epithelial, insect cell, and reticulocyte lysates show that an NH2-terminal fragment of cingulin (1–378) interacts in vitro with ZO-1 (K d ∼5 nM), ZO-2, ZO-3, myosin, and AF-6, but not with symplekin, and a COOH-terminal fragment (377–1,368) interacts with myosin and ZO-3. ZO-1 and ZO-2 immunoprecipitates contain cingulin, suggesting in vivo interactions. Full-length cingulin, but not NH2-terminal and COOH-terminal fragments, colocalizes with endogenous cingulin in transfected MDCK cells, indicating that sequences within both head and rod domains are required for TJ localization. We propose that cingulin is a functionally important component of TJ, linking the submembrane plaque domain of TJ to the actomyosin cytoskeleton. PMID:10613913

  9. Recent and Long-Term Soccer Heading Exposure Is Differentially Associated With Neuropsychological Function in Amateur Players.

    PubMed

    Levitch, Cara F; Zimmerman, Molly E; Lubin, Naomi; Kim, Namhee; Lipton, Richard B; Stewart, Walter F; Kim, Mimi; Lipton, Michael L

    2018-02-01

    The present study examined the relative contribution of recent or long-term heading to neuropsychological function in amateur adult soccer players. Soccer players completed a baseline questionnaire (HeadCount-12m) to ascertain heading during the prior 12 months (long-term heading, LTH) and an online questionnaire (HeadCount-2w) every 3 months to ascertain heading during the prior 2 weeks (recent heading, RH). Cogstate, a battery of six neuropsychological tests, was administered to assess neuropsychological function. Generalized estimating equations were used to test if LTH or RH was associated with neuropsychological function while accounting for the role of recognized concussion. A total of 311 soccer players completed 630 HeadCount-2w. Participants had an average age of 26 years. Participants headed the ball a median of 611 times/year (mean=1,384.03) and 9.50 times/2 weeks (mean=34.17). High levels of RH were significantly associated with reduced performance on a task of psychomotor speed (p=.02), while high levels of LTH were significantly associated with poorer performance on tasks of verbal learning (p=.03) and verbal memory (p=.04). Significantly better attention (p=.02) was detectable at moderately high levels of RH, but not at the highest level of RH. One hundred and seven (34.4%) participants reported a lifetime history of concussion, but this was not related to neuropsychological function and did not modify the association of RH or LTH with neuropsychological function. High levels of both RH and LTH were associated with poorer neuropsychological function, but on different domains. The clinical manifestations following repetitive exposure to heading could change with chronicity of exposure. (JINS, 2018, 24, 147-155).

  10. What are Head Cavities? - A History of Studies on Vertebrate Head Segmentation.

    PubMed

    Kuratani, Shigeru; Adachi, Noritaka

    2016-06-01

    Motivated by the discovery of segmental epithelial coeloms, or "head cavities," in elasmobranch embryos toward the end of the 19th century, the debate over the presence of mesodermal segments in the vertebrate head became a central problem in comparative embryology. The classical segmental view assumed only one type of metamerism in the vertebrate head, in which each metamere was thought to contain one head somite and one pharyngeal arch, innervated by a set of cranial nerves serially homologous to dorsal and ventral roots of spinal nerves. The non-segmental view, on the other hand, rejected the somite-like properties of head cavities. A series of small mesodermal cysts in early Torpedo embryos, which were thought to represent true somite homologs, provided a third possible view on the nature of the vertebrate head. Recent molecular developmental data have shed new light on the vertebrate head problem, explaining that head mesoderm evolved, not by the modification of rostral somites of an amphioxus-like ancestor, but through the polarization of unspecified paraxial mesoderm into head mesoderm anteriorly and trunk somites posteriorly.

  11. Head circumference (image)

    MedlinePlus

    Head circumference is a measurement of the circumference of the child's head at its largest area, above the eyebrows and ears and around the back of the head. During routine check-ups, the distance is ...

  12. Identification of a Region in the Stalk Domain of the Nipah Virus Receptor Binding Protein That Is Critical for Fusion Activation

    PubMed Central

    Talekar, Aparna; DeVito, Ilaria; Salah, Zuhair; Palmer, Samantha G.; Chattopadhyay, Anasuya; Rose, John K.; Xu, Rui; Wilson, Ian A.; Moscona, Anne

    2013-01-01

    Paramyxoviruses, including the emerging lethal human Nipah virus (NiV) and the avian Newcastle disease virus (NDV), enter host cells through fusion of the viral and target cell membranes. For paramyxoviruses, membrane fusion is the result of the concerted action of two viral envelope glycoproteins: a receptor binding protein and a fusion protein (F). The NiV receptor binding protein (G) attaches to ephrin B2 or B3 on host cells, whereas the corresponding hemagglutinin-neuraminidase (HN) attachment protein of NDV interacts with sialic acid moieties on target cells through two regions of its globular domain. Receptor-bound G or HN via its stalk domain triggers F to undergo the conformational changes that render it competent to mediate fusion of the viral and cellular membranes. We show that chimeric proteins containing the NDV HN receptor binding regions and the NiV G stalk domain require a specific sequence at the connection between the head and the stalk to activate NiV F for fusion. Our findings are consistent with a general mechanism of paramyxovirus fusion activation in which the stalk domain of the receptor binding protein is responsible for F activation and a specific connecting region between the receptor binding globular head and the fusion-activating stalk domain is required for transmitting the fusion signal. PMID:23903846

  13. Oxime ether lipids containing hydroxylated head groups are more superior siRNA delivery agents than their nonhydroxylated counterparts

    PubMed Central

    Gupta, Kshitij; Mattingly, Stephanie J; Knipp, Ralph J; Afonin, Kirill A; Viard, Mathias; Bergman, Joseph T; Stepler, Marissa; Nantz, Michael H; Puri, Anu; Shapiro, Bruce A

    2015-01-01

    Aim: To evaluate the structure–activity relationship of oxime ether lipids (OELs) containing modifications in the hydrophobic domains (chain length, degree of unsaturation) and hydrophilic head groups (polar domain hydroxyl groups) toward complex formation with siRNA molecules and siRNA delivery efficiency of resulting complexes to a human breast cancer cell line (MDA-MB-231). Materials & methods: Ability of lipoplex formation between oxime ether lipids with nucleic acids were examined using biophysical techniques. The potential of OELs to deliver nucleic acids and silence green fluorescent protein (GFP) gene was analyzed using MDA-MB-231 and MDA-MB-231/GFP cells, respectively. Results & conclusion: Introduction of hydroxyl groups to the polar domain of the OELs and unsaturation into the hydrophobic domain favor higher transfection and gene silencing in a cell culture system. PMID:26107486

  14. Heading in football. Part 3: Effect of ball properties on head response

    PubMed Central

    Shewchenko, N; Withnall, C; Keown, M; Gittens, R; Dvorak, J

    2005-01-01

    Objectives: Head impacts from footballs are an essential part of the game but have been implicated in mild and acute neuropsychological impairment. Ball characteristics have been noted in literature to affect the impact response of the head; however, the biomechanics are not well understood. The present study determined whether ball mass, pressure, and construction characteristics help reduce head and neck can impact response. Methods: Head responses under ball impact (6–7 m/s) were measured with a biofidelic numerical human model and controlled human subject trials (n = 3). Three ball masses and four ball pressures were investigated for frontal heading. Further, the effect of ball construction in wet/dry conditions was studied with the numerical model. The dynamic ball characteristics were determined experimentally. Head linear and angular accelerations were measured and compared with injury assessment functions comprising peak values and head impact power. Neck responses were assessed with the numerical model. Results: Ball mass reductions up to 35% resulted in decreased head responses up to 23–35% for the numerical and subject trials. Similar decreases in neck axial and shear responses were observed. Ball pressure reductions of 50% resulted in head and neck response reductions up to 10–31% for the subject trials and numerical model. Head response reductions up to 15% were observed between different ball constructions. The wet condition generally resulted in greater head and neck responses of up to 20%. Conclusion: Ball mass, pressure, and construction can reduce the impact severity to the head and neck. It is foreseeable that the benefits can be extended to players of all ages and skill levels. PMID:16046354

  15. Head MRI

    MedlinePlus

    ... the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head ... the test, tell your provider if you have: Brain aneurysm clips An artificial heart valves Heart defibrillator ...

  16. A residue located at the junction of the head and stalk regions of measles virus fusion protein regulates membrane fusion by controlling conformational stability.

    PubMed

    Satoh, Yuto; Yonemori, Saeka; Hirose, Mitsuhiro; Shogaki, Hiroko; Wakimoto, Hiroshi; Kitagawa, Yoshinori; Gotoh, Bin; Shirai, Tsuyoshi; Takahashi, Ken-Ichi; Itoh, Masae

    2017-02-01

    The fusion (F) protein of measles virus performs refolding from the thermodynamically metastable prefusion form to the highly stable postfusion form via an activated unstable intermediate stage, to induce membrane fusion. Some amino acids involved in the fusion regulation cluster in the heptad repeat B (HR-B) domain of the stalk region, among which substitution of residue 465 by various amino acids revealed that fusion activity correlates well with its side chain length from the Cα (P<0.01) and van der Waals volume (P<0.001), except for Phe, Tyr, Trp, Pro and His carrying ring structures. Directed towards the head region, longer side chains of the non-ring-type 465 residues penetrate more deeply into the head region and may disturb the hydrophobic interaction between the stalk and head regions and cause destabilization of the molecule by lowering the energy barrier for refolding, which conferred the F protein enhanced fusion activity. Contrarily, the side chain of ring-type 465 residues turned away from the head region, resulting in not only no contact with the head region but also extensive coverage of the HR-B surface, which may prevent the dissociation of the HR-B bundle for initiation of membrane fusion and suppress fusion activity. Located in the HR-B domain just at the junction between the head and stalk regions, amino acid 465 is endowed with a possible ability to either destabilize or stabilize the F protein depending on its molecular volume and the direction of the side chain, regulating fusion activity of measles virus F protein.

  17. Heading-vector navigation based on head-direction cells and path integration.

    PubMed

    Kubie, John L; Fenton, André A

    2009-05-01

    Insect navigation is guided by heading vectors that are computed by path integration. Mammalian navigation models, on the other hand, are typically based on map-like place representations provided by hippocampal place cells. Such models compute optimal routes as a continuous series of locations that connect the current location to a goal. We propose a "heading-vector" model in which head-direction cells or their derivatives serve both as key elements in constructing the optimal route and as the straight-line guidance during route execution. The model is based on a memory structure termed the "shortcut matrix," which is constructed during the initial exploration of an environment when a set of shortcut vectors between sequential pairs of visited waypoint locations is stored. A mechanism is proposed for calculating and storing these vectors that relies on a hypothesized cell type termed an "accumulating head-direction cell." Following exploration, shortcut vectors connecting all pairs of waypoint locations are computed by vector arithmetic and stored in the shortcut matrix. On re-entry, when local view or place representations query the shortcut matrix with a current waypoint and goal, a shortcut trajectory is retrieved. Since the trajectory direction is in head-direction compass coordinates, navigation is accomplished by tracking the firing of head-direction cells that are tuned to the heading angle. Section 1 of the manuscript describes the properties of accumulating head-direction cells. It then shows how accumulating head-direction cells can store local vectors and perform vector arithmetic to perform path-integration-based homing. Section 2 describes the construction and use of the shortcut matrix for computing direct paths between any pair of locations that have been registered in the shortcut matrix. In the discussion, we analyze the advantages of heading-based navigation over map-based navigation. Finally, we survey behavioral evidence that nonhippocampal

  18. Usability engineering: domain analysis activities for augmented-reality systems

    NASA Astrophysics Data System (ADS)

    Gabbard, Joseph; Swan, J. E., II; Hix, Deborah; Lanzagorta, Marco O.; Livingston, Mark; Brown, Dennis B.; Julier, Simon J.

    2002-05-01

    This paper discusses our usability engineering process for the Battlefield Augmented Reality System (BARS). Usability engineering is a structured, iterative, stepwise development process. Like the related disciplines of software and systems engineering, usability engineering is a combination of management principals and techniques, formal and semi- formal evaluation techniques, and computerized tools. BARS is an outdoor augmented reality system that displays heads- up battlefield intelligence information to a dismounted warrior. The paper discusses our general usability engineering process. We originally developed the process in the context of virtual reality applications, but in this work we are adapting the procedures to an augmented reality system. The focus of this paper is our work on domain analysis, the first activity of the usability engineering process. We describe our plans for and our progress to date on our domain analysis for BARS. We give results in terms of a specific urban battlefield use case we have designed.

  19. Conformational dynamics and ligand binding in the multi-domain protein PDC109.

    PubMed

    Kim, Hyun Jin; Choi, Moo Young; Kim, Hyung J; Llinás, Miguel

    2010-02-18

    PDC109 is a modular multi-domain protein with two fibronectin type II (Fn2) repeats joined by a linker. It plays a major role in bull sperm binding to the oviductal epithelium through its interactions with phosphorylcholines (PhCs), a head group of sperm cell membrane lipids. The crystal structure of the PDC109-PhC complex shows that each PhC binds to the corresponding Fn2 domain, while the two domains are on the same face of the protein. Long timescale explicit solvent molecular dynamics (MD) simulations of PDC109, in the presence and absence of PhC, suggest that PhC binding strongly correlates with the relative orientation of choline-phospholipid binding sites of the two Fn2 domains; unless the two domains tightly bind PhCs, they tend to change their relative orientation by deforming the flexible linker. The effective PDC109-PhC association constant of 28 M(-1), estimated from their potential of mean force is consistent with the experimental result. Principal component analysis of the long timescale MD simulations was compared to the significantly less expensive normal mode analysis of minimized structures. The comparison indicates that difference between relative domain motions of PDC109 with bound and unbound PhC is captured by the first principal component in the principal component analysis as well as the three lowest normal modes in the normal mode analysis. The present study illustrates the use of detailed MD simulations to clarify the energetics of specific ligand-domain interactions revealed by a static crystallographic model, as well as their influence on relative domain motions in a multi-domain protein.

  20. Electron holography study of magnetization behavior in the writer pole of a perpendicular magnetic recording head by a 1 MV transmission electron microscope.

    PubMed

    Hirata, Kei; Ishida, Yoichi; Akashi, Tetsuya; Shindo, Daisuke; Tonomura, Akira

    2012-01-01

    The magnetic domain structure of the writer poles of perpendicular magnetic recording heads was studied using electron holography. Although the domain structure of a 100-nm-thick writer pole could be observed with a 300 kV transmission electron microscope, that of the 250-nm-thick writer pole could not be analyzed due to the limited transmission capability of the instrument. On the other hand, the detailed domain structure of the 250-nm-thick writer pole was successfully analyzed by a 1 MV electron microscope using its high transmission capability. The thickness and material dependency of the domain structure of a writer pole were discussed.

  1. Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications.

    PubMed

    Sugi, Haruo; Chaen, Shigeru; Akimoto, Tsuyoshi

    2018-05-04

    The most straightforward way to get information on the performance of individual myosin heads producing muscle contraction may be to record their movement, coupled with ATP hydrolysis, electron-microscopically using the gas environmental chamber (EC). The EC enables us to visualize and record ATP-induced myosin head movement in hydrated skeletal muscle myosin filaments. When actin filaments are absent, myosin heads fluctuate around a definite neutral position, so that their time-averaged mean position remains unchanged. On application of ATP, myosin heads are found to move away from, but not towards, the bare region, indicating that myosin heads perform a recovery stroke (average amplitude, 6 nm). After exhaustion of ATP, myosin heads return to their neutral position. In the actin⁻myosin filament mixture, myosin heads form rigor actin myosin linkages, and on application of ATP, they perform a power stroke by stretching adjacent elastic structures because of a limited amount of applied ATP ≤ 10 µM. The average amplitude of the power stroke is 3.3 nm and 2.5 nm at the distal and the proximal regions of the myosin head catalytic domain (CAD), respectively. The power stroke amplitude increases appreciably at low ionic strength, which is known to enhance Ca 2+ -activated force in muscle. In both the power and recovery strokes, myosin heads return to their neutral position after exhaustion of ATP.

  2. Ceramic Heads Decrease Metal Release Caused by Head-taper Fretting and Corrosion.

    PubMed

    Kocagoz, Sevi B; Underwood, Richard J; MacDonald, Daniel W; Gilbert, Jeremy L; Kurtz, Steven M

    2016-04-01

    Metal release resulting from taper fretting and corrosion is a clinical concern, because wear and corrosion products may stimulate adverse local tissue reactions. Unimodular hip arthroplasties have a conical taper between the femoral head (head bore taper) and the femoral stem (stem cone taper). The use of ceramic heads has been suggested as a way of reducing the generation of wear and corrosion products from the head bore/stem cone taper junction. A previous semiquantitative study found that ceramic heads had less visual evidence of fretting-corrosion damage compared with CoCr heads; but, to our knowledge, no studies have quantified the volumetric material loss from the head bore and stem cone tapers of a matched cohort of ceramic and metal heads. We asked: (1) Do ceramic heads result in less volume of material loss at the head-stem junction compared with CoCr heads; (2) do stem cone tapers have less volumetric material loss compared with CoCr head bore tapers; (3) do visual fretting-corrosion scores correlate with volumetric material loss; and (4) are device, patient, or intraoperative factors associated with volumetric material loss? A quantitative method was developed to estimate volumetric material loss from the head and stem taper in previously matched cohorts of 50 ceramic and 50 CoCr head-stem pairs retrieved during revision surgery for causes not related to adverse reactions to metal particles. The cohorts were matched according to (1) implantation time, (2) stem flexural rigidity, and (3) lateral offset. Fretting corrosion was assessed visually using a previously published four-point, semiquantitative scoring system. The volumetric loss was measured using a precision roundness machine. Using 24 equally spaced axial traces, the volumetric loss was estimated using a linear least squares fit to interpolate the as-manufactured surfaces. The results of this analysis were considered in the context of device (taper angle clearance, head size, head offset

  3. Heading in the right direction? An innovative approach toward proper patient head positioning

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grush, William H.; Steffen, Gary A

    2002-12-31

    An in-house-manufactured modification of the standard A-F foam rubber head-neck supports (aka. Timo Supports) was designed to eliminate clinical setup problems with head immobilization and instability during treatment, thus providing for a more comfortable head rest for the patient. The custom design of this head holder seeks to eliminate superior-to-inferior shift, and minimize the lateral right-to-left rotational movement of the head when coupled with an AquaPlast casting system. By focusing attention to the seating of the occipital portion of the head and contour of the patient's neck, the aforementioned problems of movement were addressed, while adhering to the interests ofmore » patient comfort in this modified head support system.« less

  4. Pivoting-Head Wrench

    NASA Technical Reports Server (NTRS)

    Bradley, Glen L.

    1993-01-01

    Wrench ends pivot so it can be used to loosen or tighten nuts or bolts in confined spaces. One end equipped with open-end socket; other end, with double-hexagon socket. Heads pivot on pins. Pins fit tightly so heads do not flop; friction on pins sufficient to hold heads in positions until rotated intentionally.

  5. Chromaticity effects on head-tail instabilities for broadband impedance using two particle model, Vlasov analysis, and simulations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chin, Yong Ho; Chao, Alexander Wu; Blaskiewicz, Michael M.

    Effects of the chromaticity on head-tail instabilities for broadband impedances are comprehensively studied, using the two particle model, the Vlasov analysis and computer simulations. We show both in the two particle model and the Vlasov analysis with the trapezoidal (semiconstant) wake model that we can derive universal contour plots for the growth factor as a function of the two dimensionless parameters: the wakefield strength, Υ, and the difference of the betatron phase advances between the head and the tail, χ. They reveal how the chromaticity affects strong head-tail instabilities and excites head-tail instabilities. We also apply the LEP (Large Electron-Positronmore » Collider) broadband resonator model to the Vlasov approach and find that the results are in very good agreement with those of the trapezoidal wake model. The theoretical findings are also reinforced by the simulation results. In conclusion, the trapezoidal wake model turns out to be a very useful tool since it significantly simplifies the time domain analysis and provides well-behaved impedance at the same time.« less

  6. Chromaticity effects on head-tail instabilities for broadband impedance using two particle model, Vlasov analysis, and simulations

    DOE PAGES

    Chin, Yong Ho; Chao, Alexander Wu; Blaskiewicz, Michael M.; ...

    2017-07-28

    Effects of the chromaticity on head-tail instabilities for broadband impedances are comprehensively studied, using the two particle model, the Vlasov analysis and computer simulations. We show both in the two particle model and the Vlasov analysis with the trapezoidal (semiconstant) wake model that we can derive universal contour plots for the growth factor as a function of the two dimensionless parameters: the wakefield strength, Υ, and the difference of the betatron phase advances between the head and the tail, χ. They reveal how the chromaticity affects strong head-tail instabilities and excites head-tail instabilities. We also apply the LEP (Large Electron-Positronmore » Collider) broadband resonator model to the Vlasov approach and find that the results are in very good agreement with those of the trapezoidal wake model. The theoretical findings are also reinforced by the simulation results. In conclusion, the trapezoidal wake model turns out to be a very useful tool since it significantly simplifies the time domain analysis and provides well-behaved impedance at the same time.« less

  7. Electroporation-Induced Cell Modifications Detected with THz Time-Domain Spectroscopy

    NASA Astrophysics Data System (ADS)

    Romeo, Stefania; Vernier, P. Thomas; Zeni, Olga

    2018-04-01

    Electroporation (electropermeabilization) increases the electrical conductivity of biological cell membranes and lowers transport barriers for normally impermeant materials. Molecular simulations suggest that electroporation begins with the reorganization of water and lipid head group dipoles in the phospholipid bilayer interface, driven by an externally applied electric field, and the evolution of the resulting defects into water-filled, lipid pores. The interior of the electroporated membrane thus contains water, which should provide a signature for detection of the electropermeabilized state. In this feasibility study, we use THz time-domain spectroscopy, a powerful tool for investigating biomolecular systems and their interactions with water, to detect electroporation in human cells subjected to permeabilizing pulsed electric fields (PEFs). The time-domain response of electroporated human monocytes was acquired with a commercial THz, time-domain spectrometer. For each sample, frequency spectra were calculated, and the absorption coefficient and refractive index were extracted in the frequency range between 0.2 and 1.5 THz. This analysis reveals a higher absorption of THz radiation by PEF-exposed cells, with respect to sham-exposed ones, consistent with the intrusion of water into the cell through the permeabilized membrane that is presumed to be associated with electroporation.

  8. Inositol Pentakisphosphate Isomers Bind PH Domains with Varying Specificity and Inhibit Phosphoinositide Interactions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    S Jackson; S Al-Saigh; C Schultz

    2011-12-31

    PH domains represent one of the most common domains in the human proteome. These domains are recognized as important mediators of protein-phosphoinositide and protein-protein interactions. Phosphoinositides are lipid components of the membrane that function as signaling molecules by targeting proteins to their sites of action. Phosphoinositide based signaling pathways govern a diverse range of important cellular processes including membrane remodeling, differentiation, proliferation and survival. Myo-Inositol phosphates are soluble signaling molecules that are structurally similar to the head groups of phosphoinositides. These molecules have been proposed to function, at least in part, by regulating PH domain-phosphoinositide interactions. Given the structural similaritymore » of inositol phosphates we were interested in examining the specificity of PH domains towards the family of myo-inositol pentakisphosphate isomers. In work reported here we demonstrate that the C-terminal PH domain of pleckstrin possesses the specificity required to discriminate between different myo-inositol pentakisphosphate isomers. The structural basis for this specificity was determined using high-resolution crystal structures. Moreover, we show that while the PH domain of Grp1 does not possess this high degree of specificity, the PH domain of protein kinase B does. These results demonstrate that some PH domains possess enough specificity to discriminate between myo-inositol pentakisphosphate isomers allowing for these molecules to differentially regulate interactions with phosphoinositides. Furthermore, this work contributes to the growing body of evidence supporting myo-inositol phosphates as regulators of important PH domain-phosphoinositide interactions. Finally, in addition to expanding our knowledge of cellular signaling, these results provide a basis for developing tools to probe biological pathway.« less

  9. Eye and head motion during head turns in spaceflight

    NASA Technical Reports Server (NTRS)

    Thornton, William E.; Uri, John J.; Moore, Thomas P.; Pool, Sam L.

    1988-01-01

    Eye-head motion was studied pre-, in- and postflight during single voluntary head turns. A transient increase in vestibulo-ocular reflex (VOR) gain occurred early in the flight, but later trended toward normal. This increased gain was produced by a relative increase in eye counterrotation velocity. Asymmetries in gain with right and left turns also occurred, caused by asymmetries in eye counterrotation velocities. These findings were remarkably similar to those from Soviet primate studies using gaze fixation targets, except the human study trended more rapidly toward normal. These findings differ substantially from those measuring VOR gain by head oscillation, in which no significant changes were found inflight. No visual disturbances were noted in either test condition or in normal activities. These head turn studies are the only ones to date documenting any functional change in VOR in weightlessness.

  10. Phosphoinositide Signaling Regulates the Exocyst Complex and Polarized Integrin Trafficking in Directionally Migrating Cells

    PubMed Central

    Thapa, Narendra; Sun, Yue; Schramp, Mark; Choi, Suyoung; Ling, Kun; Anderson, Richard A

    2011-01-01

    Summary Polarized delivery of signaling and adhesion molecules to the leading edge is required for directional migration of cells. Here, we describe a role for the PIP2 synthesizing enzyme, PIPKIγi2, in regulation of exocyst complex control of cell polarity and polarized integrin trafficking during migration. Loss of PIPKIγi2 impaired directional migration, formation of cell polarity, and integrin trafficking to the leading edge. Upon initiation of directional migration PIPKIγi2 via PIP2 generation controls the integration of the exocyst complex into an integrin-containing trafficking compartment(s) that requires the talin-binding ability of PIPKIγi2, and talin for integrin recruitment to the leading edge. A PIP2 requirement is further emphasized by inhibition of PIPKIγi2-regulated directional migration by an Exo70 mutant deficient in PIP2 binding. These results reveal how phosphoinositide generation orchestrates polarized trafficking of integrin in coordination with talin that links integrins to the actin cytoskeleton, processes that are required for directional migration. PMID:22264730

  11. Effects of head tilt on visual field testing with a head-mounted perimeter imo

    PubMed Central

    Matsumoto, Chota; Nomoto, Hiroki; Numata, Takuya; Eura, Mariko; Yamashita, Marika; Hashimoto, Shigeki; Okuyama, Sachiko; Kimura, Shinji; Yamanaka, Kenzo; Chiba, Yasutaka; Aihara, Makoto; Shimomura, Yoshikazu

    2017-01-01

    Purpose A newly developed head-mounted perimeter termed “imo” enables visual field (VF) testing without a fixed head position. Because the positional relationship between the subject’s head and the imo is fixed, the effects of head position changes on the test results are small compared with those obtained using a stationary perimeter. However, only ocular counter-roll (OCR) induced by head tilt might affect VF testing. To quantitatively reveal the effects of head tilt and OCR on the VF test results, we investigated the associations among the head-tilt angle, OCR amplitude and VF testing results. Subjects and methods For 20 healthy subjects, we binocularly recorded static OCR (s-OCR) while tilting the subject’s head at an arbitrary angle ranging from 0° to 60° rightward or leftward in 10° increments. By monitoring iris patterns, we evaluated the s-OCR amplitude. We also performed blind spot detection while tilting the subject’s head by an arbitrary angle ranging from 0° to 50° rightward or leftward in 10° increments to calculate the angle by which the blind spot rotates because of head tilt. Results The association between s-OCR amplitude and head-tilt angle showed a sinusoidal relationship. In blind spot detection, the blind spot rotated to the opposite direction of the head tilt, and the association between the rotation angle of the blind spot and the head-tilt angle also showed a sinusoidal relationship. The rotation angle of the blind spot was strongly correlated with the s-OCR amplitude (R2≥0.94, p<0.0001). A head tilt greater than 20° with imo causes interference between adjacent test areas. Conclusions Both the s-OCR amplitude and the rotation angle of the blind spot were correlated with the head-tilt angle by sinusoidal regression. The rotated VF was correlated with the s-OCR amplitude. During perimetry using imo, the change in the subject’s head tilt should be limited to 20°. PMID:28945777

  12. Correlation between swallowing-related quality of life and videofluoroscopy after head and neck cancer treatment.

    PubMed

    Andrade, Margareth Souza; Gonçalves, Aline Nogueira; Guedes, Renata Lígia Vieira; Barcelos, Camila Barbosa; Slobodticov, Luciana Dall'Agnol Siqueira; Lopes, Simone Aparecida Claudino; Francisco, Ana Lúcia Noronha; Angelis, Elisabete Carrara de

    2017-03-09

    The use of symptom-specific questionnaires on head and neck cancer (HNC), together with objective swallowing measures, can be sensitive to changes in quality of life (QoL) resulting from dysphagia, but this tool is not broadly used as a complement to clinical evaluations. To analyze the correlation between the M. D. Anderson Dysphagia Inventory (MDADI) questionnaire and videofluoroscopy (VF) in patients treated for head and neck cancer. This is a retrospective study with review of clinical data, VF and MDADI results. The study sample was composed of adult patients (>18 y.o.) treated for tumors at the oral cavity, oropharynx, hypopharynx, and larynx, regardless of treatment type. For the VF examination, swallowing of 5 and 20 ml of nectar-thick liquids were considered. The Mann-Whitney nonparametric test was applied to evaluate the correlations between the MDADI and VF. Thirty-nine patients, mostly men (87.18%), with mean age of 61 years participated in the study. Most patients (16) presented oral cavity tumors (41.03%). Twenty-two patients were in advanced clinical stage (IV). Surgery was the most prevalent treatment (41.03%). Approximately half of the participants (20) received oral feeding. The total mean (TM) on the MDADI was 63.36. Comparison between VF and MDADI data showed significant correlation between TM, emotional domain (ED), and physical domain (PD) with penetration during the swallowing of 5 ml. Penetration and aspiration with 20 ml determined worse QoL on the global (p=0.018 and p=0.0053), emotional (p=0.0012 and p=0.027) and physical (p=0.0002 and p=0.0051) domains, and TM (p=0.0023 and p=0.0299), respectively. The presence of stasis did not determine worse QoL. Patients treated for HNC who presented penetration/aspiration showed worse QoL on the emotional and physical domains of the MDADI.

  13. Optic Nerve Head Development in Healthy Infants and Children Using Handheld Spectral-Domain Optical Coherence Tomography.

    PubMed

    Patel, Aarti; Purohit, Ravi; Lee, Helena; Sheth, Viral; Maconachie, Gail; Papageorgiou, Eleni; McLean, Rebecca J; Gottlob, Irene; Proudlock, Frank A

    2016-10-01

    To determine feasibility of optic nerve head (ONH) imaging and to characterize ONH development in full-term infants without sedation using handheld spectral-domain optical coherence tomography (SD OCT). Prospective cross-sectional study. Three hundred fifty-two children aged between 1 day and 13 years. All participants were imaged using handheld SD OCT without sedation during a single scan session. The percentage of successful scans was calculated. Interexaminer reproducibility and differences between right and left eyes were assessed using intraclass correlation coefficients (ICCs). Images were analyzed using ImageJ software. The developmental trajectories over time for ONH parameters were calculated using fractional polynomial modelling. Disc and cup diameter (expressed as distance in micrometers and visual angle in degrees), cup depth, Bruch's membrane opening-minimum rim width (BMO-MRW), retinal thickness, and retinal nerve fiber layer (RNFL; 1700 μm and 6° from the disc center). On average, 70% of participants were imaged successfully. Interexaminer reliability was excellent (ICC, >0.89) for diametric and retinal thickness parameters. Right and left eyes were similar for diametric measurements (ICC, >0.79), but more variable for nasal BMO-MRW, RNFL, and retinal thickness. The mean disc and cup diameter increase by 30% and 40%, respectively, between birth and 13 years of age when expressed as a distance measure, but remained constant (at 5°-5.5° and 2°, respectively) when expressed as a visual angle with reference to the eye nodal point. The peripapillary temporal RNFL demonstrated a marked initial decrease of nearly 35% between birth and approximately 18 months of age. This was followed by a slow increase up to 12 years of age when measured at 1700 μm from the disc center, although there was little change when measured at 6° from the disc center. We demonstrated feasibility of handheld SD OCT imaging of the ONH in full-term infants and children without

  14. Understanding Overuse of Computed Tomography for Minor Head Injury in the Emergency Department: A Triangulated Qualitative Study.

    PubMed

    Melnick, Edward R; Shafer, Katherine; Rodulfo, Nayeli; Shi, Joyce; Hess, Erik P; Wears, Robert L; Qureshi, Rija A; Post, Lori A

    2015-12-01

    Overuse of computed tomography (CT) for minor head injury continues despite developed and rigorously validated clinical decision rules like the Canadian CT Head Rule (CCHR). Adherence to this sensitive and specific rule could decrease the number of CT scans performed in minor head injury by 35%. But in practice, the CCHR has failed to reduce testing, despite its accurate performance. The objective was to identify nonclinical, human factors that promote or inhibit the appropriate use of CT in patients presenting to the emergency department (ED) with minor head injury. This was a qualitative study in three phases, each with interview guides developed by a multidisciplinary team. Subjects were recruited from patients treated and released with minor head injuries and providers in an urban academic ED and a satellite community ED. Focus groups of patients (four groups, 22 subjects total) and providers (three groups, 22 subjects total) were conducted until thematic saturation was reached. The findings from the focus groups were triangulated with a cognitive task analysis, including direct observation in the ED (>150 hours), and individual semistructured interviews using the critical decision method with four senior physician subject matter experts. These experts are recognized by their peers for their skill in safely minimizing testing while maintaining patient safety and engagement. Focus groups and interviews were audio recorded and notes were taken by two independent note takers. Notes were entered into ATLAS.ti and analyzed using the constant comparative method of grounded theory, an iterative coding process to determine themes. Data were double-coded and examined for discrepancies to establish consensus. Five core domains emerged from the analysis: establishing trust, anxiety (patient and provider), constraints related to ED practice, the influence of others, and patient expectations. Key themes within these domains included patient engagement, provider confidence

  15. The point spread function of the human head and its implications for transcranial current stimulation

    NASA Astrophysics Data System (ADS)

    Dmochowski, Jacek P.; Bikson, Marom; Parra, Lucas C.

    2012-10-01

    Rational development of transcranial current stimulation (tCS) requires solving the ‘forward problem’: the computation of the electric field distribution in the head resulting from the application of scalp currents. Derivation of forward models has represented a major effort in brain stimulation research, with model complexity ranging from spherical shells to individualized head models based on magnetic resonance imagery. Despite such effort, an easily accessible benchmark head model is greatly needed when individualized modeling is either undesired (to observe general population trends as opposed to individual differences) or unfeasible. Here, we derive a closed-form linear system which relates the applied current to the induced electric potential. It is shown that in the spherical harmonic (Fourier) domain, a simple scalar multiplication relates the current density on the scalp to the electric potential in the brain. Equivalently, the current density in the head follows as the spherical convolution between the scalp current distribution and the point spread function of the head, which we derive. Thus, if one knows the spherical harmonic representation of the scalp current (i.e. the electrode locations and current intensity to be employed), one can easily compute the resulting electric field at any point inside the head. Conversely, one may also readily determine the scalp current distribution required to generate an arbitrary electric field in the brain (the ‘backward problem’ in tCS). We demonstrate the simplicity and utility of the model with a series of characteristic curves which sweep across a variety of stimulation parameters: electrode size, depth of stimulation, head size and anode-cathode separation. Finally, theoretically optimal montages for targeting an infinitesimal point in the brain are shown.

  16. Two heads are better than one: crystal structure of the insect derived double domain Kazal inhibitor rhodniin in complex with thrombin.

    PubMed

    van de Locht, A; Lamba, D; Bauer, M; Huber, R; Friedrich, T; Kröger, B; Höffken, W; Bode, W

    1995-11-01

    Rhodniin is a highly specific inhibitor of thrombin isolated from the assassin bug Rhodnius prolixus. The 2.6 Angstrum crystal structure of the non-covalent complex between recombinant rhodniin and bovine alpha-thrombin reveals that the two Kazal-type domains of rhodniin bind to different sites of thrombin. The amino-terminal domain binds in a substrate-like manner to the narrow active-site cleft of thrombin; the imidazole group of the P1 His residue extends into the S1 pocket to form favourable hydrogen/ionic bonds with Asp189 at its bottom, and additionally with Glu192 at its entrance. The carboxy-terminal domain, whose distorted reactive-site loop cannot adopt the canonical conformation, docks to the fibrinogen recognition exosite via extensive electrostatic interactions. The rather acidic polypeptide linking the two domains is displaced from the thrombin surface, with none of its residues involved in direct salt bridges with thrombin. The tight (Ki = 2 x 10(-13) M) binding of rhodniin to thrombin is the result of the sum of steric and charge complementarity of the amino-terminal domain towards the active-site cleft, and of the electrostatic interactions between the carboxy-terminal domain and the exosite.

  17. Human brain factor 1, a new member of the fork head gene family

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Murphy, D.B.; Wiese, S.; Burfeind, P.

    1994-06-01

    Analysis of cDNA clones that cross-hybridized with the fork head domain of the rat HNF-3 gene family revealed 10 cDNAs from human fetal brain and human testis cDNA libraries containing this highly conserved DNA-binding domain. Three of these cDNAs (HFK1, HFK2, and HFK3) were further analyzed. The cDNA HFK1 has a length of 2557 nucleotides and shows strong homology at the nucleotide level (91.2%) to brain factor 1 (BF-1) from rat. The HFK1 cDNA codes for a putative 476 amino acid protein. The homology to BF-1 from rat in the coding region at the amino acid level is 87.5%. Themore » fork head homologous region includes 111 amino acids starting at amino acid 160 and has a 97.5% homology to BF-1. Southern hybridization revealed that HFK1 is highly conserved among mammalian species and possibly birds. Northern analysis with total RNA from human tissues and poly(A)-rich RNA from mouse revealed a 3.2-kb transcript that is present in human and mouse fetal brain and in adult mouse brain. In situ hybridization with sections of mouse embryo and human fetal brain reveals that HFK1 expression is restricted to the neuronal cells in the telencepthalon, with strong expression being observed in the developing dentate gyrus and hippocampus. HFK1 was chromosomally localized by in situ hybridization to 14q12. The cDNA clones HFK2 and HFK3 were analyzed by restriction analysis and sequencing. HFK2 and HFK3 were found to be closely related but different from HFK1. Therefore, it would appear that HFK1, HFK2, HFK3, and BF-1 form a new fork head related subfamily. 33 refs., 6 figs.« less

  18. Supra-domains: evolutionary units larger than single protein domains.

    PubMed

    Vogel, Christine; Berzuini, Carlo; Bashton, Matthew; Gough, Julian; Teichmann, Sarah A

    2004-02-20

    Domains are the evolutionary units that comprise proteins, and most proteins are built from more than one domain. Domains can be shuffled by recombination to create proteins with new arrangements of domains. Using structural domain assignments, we examined the combinations of domains in the proteins of 131 completely sequenced organisms. We found two-domain and three-domain combinations that recur in different protein contexts with different partner domains. The domains within these combinations have a particular functional and spatial relationship. These units are larger than individual domains and we term them "supra-domains". Amongst the supra-domains, we identified some 1400 (1203 two-domain and 166 three-domain) combinations that are statistically significantly over-represented relative to the occurrence and versatility of the individual component domains. Over one-third of all structurally assigned multi-domain proteins contain these over-represented supra-domains. This means that investigation of the structural and functional relationships of the domains forming these popular combinations would be particularly useful for an understanding of multi-domain protein function and evolution as well as for genome annotation. These and other supra-domains were analysed for their versatility, duplication, their distribution across the three kingdoms of life and their functional classes. By examining the three-dimensional structures of several examples of supra-domains in different biological processes, we identify two basic types of spatial relationships between the component domains: the combined function of the two domains is such that either the geometry of the two domains is crucial and there is a tight constraint on the interface, or the precise orientation of the domains is less important and they are spatially separate. Frequently, the role of the supra-domain becomes clear only once the three-dimensional structure is known. Since this is the case for only a

  19. Atomic structure of the vimentin central α-helical domain and its implications for intermediate filament assembly.

    PubMed

    Chernyatina, Anastasia A; Nicolet, Stefan; Aebi, Ueli; Herrmann, Harald; Strelkov, Sergei V

    2012-08-21

    Together with actin filaments and microtubules, intermediate filaments (IFs) are the basic cytoskeletal components of metazoan cells. Over 80 human diseases have been linked to mutations in various IF proteins to date. However, the filament structure is far from being resolved at the atomic level, which hampers rational understanding of IF pathologies. The elementary building block of all IF proteins is a dimer consisting of an α-helical coiled-coil (CC) "rod" domain flanked by the flexible head and tail domains. Here we present three crystal structures of overlapping human vimentin fragments that comprise the first half of its rod domain. Given the previously solved fragments, a nearly complete atomic structure of the vimentin rod has become available. It consists of three α-helical segments (coils 1A, 1B, and 2) interconnected by linkers (L1 and L12). Most of the CC structure has a left-handed twist with heptad repeats, but both coil 1B and coil 2 also exhibit untwisted, parallel stretches with hendecad repeats. In the crystal structure, linker L1 was found to be α-helical without being involved in the CC formation. The available data allow us to construct an atomic model of the antiparallel tetramer representing the second level of vimentin assembly. Although the presence of the nonhelical head domains is essential for proper tetramer stabilization, the precise alignment of the dimers forming the tetramer appears to depend on the complementarity of their surface charge distribution patterns, while the structural plasticity of linker L1 and coil 1A plays a role in the subsequent IF assembly process.

  20. Spectral domain polarization-sensitive optical coherence tomography at 850 nm

    NASA Astrophysics Data System (ADS)

    Cense, Barry; Chen, Teresa C.; Mujat, Mircea; Joo, Chulmin; Akkin, Taner; Park, B. H.; Pierce, Mark C.; Yun, Andy; Bouma, Brett E.; Tearney, Guillermo J.; de Boer, Johannes F.

    2005-04-01

    Spectral-Domain Polarization-Sensitive Optical Coherence Tomography (SD-PS-OCT) is a technique developed to measure the thickness and birefringence of the nerve fiber layer in vivo as a tool for the early diagnosis of glaucoma. A clinical SD-PS-OCT system was developed and scans were made around the optic nerve head (ONH) using ten concentric circles of increasing diameter. One healthy volunteer was imaged. Retinal nerve fiber layer thickness and birefringence information was extracted from the data. Polarization-sensitive OCT images were acquired at video rate (29 frames per second (fps), 1000 A-lines / frame) and at 7 fps (1000 A-lines / frame). The last setting improved the signal to noise ratio by approximately 6 dB. Birefringence measurements on the healthy volunteer gave similar results as earlier reported values that were obtained with a time-domain setup. The measurement time was reduced from more than a minute to less than a second.

  1. Probing muscle myosin motor action: x-ray (m3 and m6) interference measurements report motor domain not lever arm movement.

    PubMed

    Knupp, Carlo; Offer, Gerald; Ranatunga, K W; Squire, John M

    2009-07-10

    The key question in understanding how force and movement are produced in muscle concerns the nature of the cyclic interaction of myosin molecules with actin filaments. The lever arm of the globular head of each myosin molecule is thought in some way to swing axially on the actin-attached motor domain, thus propelling the actin filament past the myosin filament. Recent X-ray diffraction studies of vertebrate muscle, especially those involving the analysis of interference effects between myosin head arrays in the two halves of the thick filaments, have been claimed to prove that the lever arm moves at the same time as the sliding of actin and myosin filaments in response to muscle length or force steps. It was suggested that the sliding of myosin and actin filaments, the level of force produced and the lever arm angle are all directly coupled and that other models of lever arm movement will not fit the X-ray data. Here, we show that, in addition to interference across the A-band, which must be occurring, the observed meridional M3 and M6 X-ray intensity changes can all be explained very well by the changing diffraction effects during filament sliding caused by heads stereospecifically attached to actin moving axially relative to a population of detached or non-stereospecifically attached heads that remain fixed in position relative to the myosin filament backbone. Crucially, and contrary to previous interpretations, the X-ray interference results provide little direct information about the position of the myosin head lever arm; they are, in fact, reporting relative motor domain movements. The implications of the new interpretation are briefly assessed.

  2. Prioritisation of associations between protein domains and complex diseases using domain-domain interaction networks.

    PubMed

    Wang, W; Zhang, W; Jiang, R; Luan, Y

    2010-05-01

    It is of vital importance to find genetic variants that underlie human complex diseases and locate genes that are responsible for these diseases. Since proteins are typically composed of several structural domains, it is reasonable to assume that harmful genetic variants may alter structures of protein domains, affect functions of proteins and eventually cause disorders. With this understanding, the authors explore the possibility of recovering associations between protein domains and complex diseases. The authors define associations between protein domains and disease families on the basis of associations between non-synonymous single nucleotide polymorphisms (nsSNPs) and complex diseases, similarities between diseases, and relations between proteins and domains. Based on a domain-domain interaction network, the authors propose a 'guilt-by-proximity' principle to rank candidate domains according to their average distance to a set of seed domains in the domain-domain interaction network. The authors validate the method through large-scale cross-validation experiments on simulated linkage intervals, random controls and the whole genome. Results show that areas under receiver operating characteristic curves (AUC scores) can be as high as 77.90%, and the mean rank ratios can be as low as 21.82%. The authors further offer a freely accessible web interface for a genome-wide landscape of associations between domains and disease families.

  3. Longitudinal Change Detected by Spectral Domain Optical Coherence Tomography in the Optic Nerve Head and Peripapillary Retina in Experimental Glaucoma

    PubMed Central

    Strouthidis, Nicholas G.; Fortune, Brad; Yang, Hongli; Sigal, Ian A.

    2011-01-01

    Purpose. To investigate whether longitudinal changes deep within the optic nerve head (ONH) are detectable by spectral domain optical coherence tomography (SDOCT) in experimental glaucoma (EG) and whether these changes are detectable at the onset of Heidelberg Retina Tomography (HRT; Heidelberg Engineering, Heidelberg, Germany)–defined surface topography depression. Methods. Longitudinal SDOCT imaging (Spectralis; Heidelberg Engineering) was performed in both eyes of nine rhesus macaques every 1 to 3 weeks. One eye of each underwent trabecular laser-induced IOP elevation. Four masked operators delineated internal limiting membrane (ILM), retinal nerve fiber layer (RNFL), Bruch's membrane/retinal pigment epithelium (BM/RPE), neural canal opening (NCO), and anterior lamina cribrosa surface (ALCS) by using custom software. Longitudinal changes were assessed and compared between the EG and control (nonlasered) eyes at the onset of HRT-detected surface depression (follow-up 1; [FU1]) and at the most recent image (follow-up 2; [FU2]). Results. Mean IOP in EG eyes was 7.1 to 24.6 mm Hg at FU1 and 13.5 to 31.9 mm Hg at FU2. In control eyes, the mean IOP was 7.2 to 12.6 mm Hg (FU1) and 8.9 to 16.0 mm Hg (FU2). At FU1, neuroretinal rim decreased and ALCS depth increased significantly (paired t-test, P < 0.01); no change in RNFL thickness was detected. At FU2, however, significant prelaminar tissue thinning, posterior displacement of NCO, and RNFL thinning were observed. Conclusions. Longitudinal SDOCT imaging can detect deep ONH changes in EG eyes, the earliest of which are present at the onset of HRT-detected ONH surface height depression. These parameters represent realistic targets for SDOCT detection of glaucomatous progression in human subjects. PMID:21217108

  4. Adapted head- and eye-movement responses to added-head inertia

    NASA Technical Reports Server (NTRS)

    Gauthier, G. M.; Martin, B. J.; Stark, L. W.

    1986-01-01

    Adaptation to inertia added to the head was studied in men by mounting masses on a rigidly attached helmet until two- to ten-fold increases of inertia were produced, while an overhead suspension compensated for the weights. The observed changes in the eye and head movement coordination included increased head movement latencies, as well as changes in the eye movement amplitude, and later stabilizing alternate contractions of the neck muscles. Oscillopsia, or continual displacement or instability of the visual world, which is a symptom of a breakdown of space constancy, was prominent and consistent in the perceptual reports of the subjects. Although adaptation resulting from adding inertia to the head occurred much faster than that induced by adding prisms or lenses, it has similar perceptual and motor components that may be objectively studied in detail.

  5. Head Lice.

    PubMed

    Meister, Laura; Ochsendorf, Falk

    2016-11-11

    Conflicting information about the proper treatment of head lice has given rise to uncertainty among patients and treating personnel. For example, the reported efficacy of permethrin fell from 97% in the 1990s to 30% in 2010. Review of the literature based on a selective search of PubMed. In Germany, outbreaks of head lice mainly occur among 5- to 13-year-olds returning to school after the summer vacation. Nymphs hatch from eggs after an average of 8 days and become sexually mature lice over the ensuing 9 days. The main route of transmission is direct head-to-head contact; transmission via inanimate objects is of no relevance. Symptoms arise 4-6 weeks after an initial infestation; many affected persons have no symptoms at all. Wet combing is the most sensitive method of establishing the diagnosis and monitoring treatment. Resistance to neurotoxic pediculocidal drugs is increasing around the world. Dimethicones are the treatment of choice, with 97% efficacy. Outbreaks must be managed with the synchronous treatment of all infested persons to break the chain of infestation. If the agent used is not ovicidal, the treatment must be repeated in 8-10 days and sometimes in a further 7 days as well. Outbreaks of head lice can be successfully terminated by synchronous treatment with ovicidal dimethicones.

  6. A Head and Neck Simulator for Radiology and Radiotherapy

    NASA Astrophysics Data System (ADS)

    Thompson, Larissa; Campos, Tarcísio P. R.

    2013-06-01

    Phantoms are suitable tools to simulate body tissues and organs in radiology and radiation therapy. This study presents the development of a physical head and neck phantom and its radiological response for simulating brain pathology. The following features on the phantom are addressed and compared to human data: mass density, chemical composition, anatomical shape, computerized tomography images and Hounsfield Units. Mass attenuation and kerma coefficients of the synthetic phantom and normal tissues, as well as their deviations, were also investigated. Radiological experiments were performed, including brain tumors and subarachnoid hemorrhage simulations. Computerized tomography images of such pathologies in phantom and human were obtained. The anthropometric dimensions of the phantom present anatomical conformation similar to a human head and neck. Elemental weight percentages of the equivalent tissues match the human ones. Hounsfield Unit values of the main developed structures are presented, approaching human data. Kerma and mass attenuation coefficients spectra from human and phantom are presented, demonstrating smaller deviations in the radiological X-ray spectral domain. In conclusion, the phantom presented suitable normal and pathological radiological responses relative to those observed in humans. It may improve radiological protocols and education in medical imaging.

  7. Grandparent Headed Families and Head Start: Developing Effective Services.

    ERIC Educational Resources Information Center

    Dannison, Linda L.; Smith, Andrea B.

    Numerous challenges face the growing number of grandparent-headed households, including isolation from friends and social supports, and difficulties in caring for grandchildren exhibiting multiple needs. This paper describes a pilot program in which a university and a large county-wide Head Start program formed a partnership to focus on serving…

  8. Hydra multiple head star sensor and its in-flight self-calibration of optical heads alignment

    NASA Astrophysics Data System (ADS)

    Majewski, L.; Blarre, L.; Perrimon, N.; Kocher, Y.; Martinez, P. E.; Dussy, S.

    2017-11-01

    HYDRA is EADS SODERN new product line of APS-based autonomous star trackers. The baseline is a multiple head sensor made of three separated optical heads and one electronic unit. Actually the concept which was chosen offers more than three single-head star trackers working independently. Since HYDRA merges all fields of view the result is a more accurate, more robust and completely autonomous multiple-head sensor, releasing the AOCS from the need to manage the outputs of independent single-head star trackers. Specific to the multiple head architecture and the underlying data fusion, is the calibration of the relative alignments between the sensor optical heads. The performance of the sensor is related to its estimation of such alignments. HYDRA design is first reminded in this paper along with simplification it can bring at system level (AOCS). Then self-calibration of optical heads alignment is highlighted through descriptions and simulation results, thus demonstrating the performances of a key part of HYDRA multiple-head concept.

  9. Evolutionarily conserved structural and functional roles of the FYVE domain.

    PubMed

    Hayakawa, Akira; Hayes, Susan; Leonard, Deborah; Lambright, David; Corvera, Silvia

    2007-01-01

    The FYVE domain is an approx. 80 amino acid motif that binds to the phosphoinositide PtdIns3P with high specificity and affinity. It is present in 38 predicted gene products within the human genome, but only in 12-13 in Caenorhabditis elegans and Drosophila melanogaster. Eight of these are highly conserved in all three organisms, and they include proteins that have not been characterized in any species. One of these, WDFY2, appears to play an important role in early endocytosis and was revealed in a RNAi (RNA interference) screen in C. elegans. Interestingly, some proteins contain FYVE-like domains in C. elegans and D. melanogaster, but have lost this domain during evolution. One of these is the homologue of Rabatin-5, a protein that, in mammalian cells, binds both Rab5 and Rabex-5, a guanine-nucleotide exchange factor for Rab5. Thus the Rabatin-5 homologue suggests that mechanisms to link PtdIns3P and Rab5 activation developed in evolution. In mammalian cells, these mechanisms are apparent in the existence of proteins that bind PtdIns3P and Rab GTPases, such as EEA1, Rabenosyn-5 and Rabip4'. Despite the comparable ability to bind to PtdIns3P in vitro, FYVE domains display widely variable abilities to interact with endosomes in intact cells. This variation is due to three distinct properties of FYVE domains conferred by residues that are not involved in PtdIns3P head group recognition: These properties are: (i) the propensity to oligomerize, (ii) the ability to insert into the membrane bilayer, and (iii) differing electrostatic interactions with the bilayer surface. The different binding properties are likely to regulate the extent and duration of the interaction of specific FYVE domain-containing proteins with early endosomes, and thereby their biological function.

  10. The randomized controlled trial of Head Start REDI: Sustained effects on developmental trajectories of social-emotional functioning.

    PubMed

    Nix, Robert L; Bierman, Karen L; Heinrichs, Brenda S; Gest, Scott D; Welsh, Janet A; Domitrovich, Celene E

    2016-04-01

    This study assessed the sustained effects of Head Start REDI (Research-based, Developmentally Informed), a randomized controlled preschool preventive intervention, on children's developmental trajectories of social-emotional functioning into elementary school. Twenty-five Head Start centers with 44 classrooms were randomly assigned to deliver Head Start REDI or Head Start as usual. Head Start REDI featured an integrated language-emergent literacy and social-emotional skills curriculum and enhanced support for positive teaching practices. The 356 4-year-old children (54% girls; 25% African American; 17% Latino; 70% living in poverty) in those centers and classrooms were followed for 5 years (from preschool through third grade; 91% retention rate). Each year, teachers rated multiple domains of social-emotional functioning. Person-oriented latent class growth models were used to identify the different developmental trajectories of social-emotional functioning that children followed. Tests of proportions revealed that children who had been in the Head Start REDI intervention were statistically significantly more likely than children in the control condition to follow the most optimal developmental trajectories of social competence, aggressive-oppositional behavior, learning engagement, attention problems, student-teacher closeness, and peer rejection (odds ratio = 1.60-1.93). These findings suggest that enriching Head Start with evidence-based curriculum components and teaching practices can have long-lasting benefits for children's social-emotional functioning. These findings elucidate how high-quality preschool experiences promote core competencies that are critical to the school success of children living in poverty. (c) 2016 APA, all rights reserved).

  11. Enhanced CAR T cell therapy: A novel approach for head and neck cancers.

    PubMed

    Wang, Songlin; Zhu, Zhao

    2018-05-05

    Head and neck cancer that presents in locally advanced stages often results in a bad prognosis with an increased recurrence rate even after curative resections. Radiation therapy is then applied, with multiple side effects, as adjuvant regional therapy. Because of the high rate of recurrence and mortality, new therapies are needed for patients suffering from head and neck malignant tumors.CAR (chimeric antigen receptor) T cell therapy, which was first devised about 25 years ago, causes the killing or apoptosis of target tumor cells through inducing the secretion of cytokines and granzymes by T cells (Cheadle et al., 2014). CARs are comprised of three canonical domains for antigen recognition, T cell activation, and co-stimulation, and are synthetic receptors that reprogram immune cells for therapeutic treatment of multiple tumors (Sadelain, 2017). This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. Structural interactions between lipids, water and S1-S4 voltage-sensing domains

    PubMed Central

    Krepkiy, Dmitriy; Gawrisch, Klaus; Swartz, Kenton J.

    2012-01-01

    Membrane proteins serve crucial signaling and transport functions, yet relatively little is known about their structures in membrane environments or how lipids interact with these proteins. For voltage-activated ion channels, X-ray structures suggest that the mobile voltage-sensing S4 helix would be exposed to the membrane, and functional studies reveal that lipid modification can profoundly alter channel activity. Here we use solid-state NMR to investigate structural interactions of lipids and water with S1-S4 voltage-sensing domains, and to explore whether lipids influence the structure of the protein. Our results demonstrate that S1-S4 domains exhibit extensive interactions with lipids, and that these domains are heavily hydrated when embedded in a membrane. We also find evidence for preferential interactions of anionic lipids with S1-S4 domains, and that these interactions have lifetimes on the timescale of 10−3s. Arg residues within S1-S4 domains are well-hydrated and are positioned in close proximity to lipids, exhibiting local interactions with both lipid head groups and acyl chains. Comparative studies with a positively charged lipid lacking a phosphodiester group reveal that this lipid modification has only modest effects on the structure and hydration of S1-S4 domains. Taken together, our results demonstrate that Arg residues in S1-S4 voltage-sensing domains reside in close proximity to the hydrophobic interior of the membrane, yet are well-hydrated, a requirement for carrying charge and driving protein motions in response to changes in membrane voltage. PMID:22858867

  13. The head-mounted microscope.

    PubMed

    Chen, Ting; Dailey, Seth H; Naze, Sawyer A; Jiang, Jack J

    2012-04-01

    Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300 mm to 700 mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

  14. Multiple-interactions among EMILIN1 and EMILIN2 N- and C-terminal domains.

    PubMed

    Bot, Simonetta; Andreuzzi, Eva; Capuano, Alessandra; Schiavinato, Alvise; Colombatti, Alfonso; Doliana, Roberto

    2015-01-01

    EMILIN1 and EMILIN2 belong to a family of extracellular matrix glycoproteins characterized by the N-terminal cysteine-rich EMI domain, a long segment with high probabilty for coiled-coil structure formation and a C-terminal gC1q domain. To study EMILIN1 and EMILIN2 interaction and assembly we have applied qualitative and quantitative two hybrid systems using constructs corresponding to the gC1q and EMI domains. The identified interactions were further confirmed in yeast extracts of co-transfected cells followed by co-immunoprecipitation. The data indicated that gC1q domains are able to self-interact as well as to interact one each other and with the EMI domains, but no self interactions were detected between the EMI domains. Furthermore EMILINs interactions were studied in 293-EBNA cells co-transfected with full lenght EMILIN1 and EMILIN2 constructs. Specific antibodies were able to co-immunoprecipitate EMILINs, indicating that also full-lenght proteins can give rise to non-covalent homo- and hetero-multimers even if reduced and alkylated before mixing. Immunofluorescence analysis on mouse cell cultures and tissues sections with specific antibodies showed co-distribution of EMILIN1 and EMILIN2. Thus, we can hypothesize that EMILINs multimers are formed by head-to-tail interaction between C-terminal and N-terminal domains of EMILIN1 and/or EMILIN2 but also by tail-to-tail interaction between gC1q domains. These multiple interactions may regulate homo-typic and/or hetero-typic linear and eventually lateral branching assemblies of EMILIN1 and EMILIN2 in tissues. Copyright © 2014. Published by Elsevier B.V.

  15. Heading Frequency Is More Strongly Related to Cognitive Performance Than Unintentional Head Impacts in Amateur Soccer Players.

    PubMed

    Stewart, Walter F; Kim, Namhee; Ifrah, Chloe; Sliwinski, Martin; Zimmerman, Molly E; Kim, Mimi; Lipton, Richard B; Lipton, Michael L

    2018-01-01

    Compared to heading, unintentional head impacts (e.g., elbow to head, head to head, head to goalpost) in soccer are more strongly related to risk of moderate to very severe Central Nervous System (CNS) symptoms. But, most head impacts associated with CNS symptoms that occur in soccer are mild and are more strongly related to heading. We tested for a differential relation of heading and unintentional head impacts with neuropsychological (NP) test performance. Active adult amateur soccer players were recruited in New York City and the surrounding areas for this repeated measures longitudinal study of individuals who were enrolled if they had 5+ years of soccer play and were active playing soccer 6+ months/year. All participants completed a baseline validated questionnaire ("HeadCount-2w"), reporting 2-week recall of soccer activity, heading and unintentional head impacts. In addition, participants also completed NP tests of verbal learning, verbal memory, psychomotor speed, attention, and working memory. Most participants also completed one or more identical follow-up protocols (i.e., HeadCount-2w and NP tests) at 3- to 6-month intervals over a 2-year period. Repeated measures General Estimating Equations (GEE) linear models were used to determine if variation in NP tests at each visit was related to variation in either heading or unintentional head impacts in the 2-week period before testing. 308 players (78% male) completed 741 HeadCount-2w. Mean (median) heading/2-weeks was 50 (17) for men and 26 (7) for women. Heading was significantly associated with poorer performance on psychomotor speed ( p  < 0.001) and attention ( p  = 0.02) tasks and was borderline significant with poorer performance on the working memory ( p  = 0.06) task. Unintentional head impacts were not significantly associated with any NP test. Results did not differ after excluding 22 HeadCount-2w with reported concussive or borderline concussive symptoms. Poorer NP test performance was

  16. Axis of Eye Rotation Changes with Head-Pitch Orientation during Head Impulses about Earth-Vertical

    PubMed Central

    Schubert, Michael C.; Clendaniel, Richard A.; Carey, John P.; Della Santina, Charles C.; Minor, Lloyd B.; Zee, David S.

    2006-01-01

    The goal of this study was to assess how the axis of head rotation, Listing's law, and eye position influence the axis of eye rotation during brief, rapid head rotations. We specifically asked how the axis of eye rotation during the initial angular vestibuloocular reflex (VOR) changed when the pitch orientation of the head relative to Earth-vertical was varied, but the initial position of the eye in the orbit and the orientation of Listing's plane with respect to the head were fixed. We measured three-dimensional eye and head rotation axes in eight normal humans using the search coil technique during head-and-trunk (whole-body) and head-on-trunk (head-only) “impulses” about an Earth-vertical axis. The head was initially oriented at one of five pitch angles (30° nose down, 15° nose down, 0°, 15° nose up, 30° nose up). The fixation target was always aligned with the nasooccipital axis. Whole-body impulses were passive, unpredictable, manual, rotations with peak-amplitude of ∼20°, peak-velocity of ∼80°/s, and peak-acceleration of ∼1000°/s2. Head-only impulses were also passive, unpredictable, manual, rotations with peak-amplitude of ∼20°, peak-velocity of ∼150°/s, and peak-acceleration of ∼3000°/s2. During whole-body impulses, the axis of eye rotation tilted in the same direction, and by an amount proportional (0.51 ± 0.09), to the starting pitch head orientation (P < 0.05). This proportionality constant decreased slightly to 0.39 ± 0.08 (P < 0.05) during head-only impulses. Using the head-only impulse data, with the head pitched up, we showed that only 50% of the tilt in the axis of eye rotation could be predicted from vectorial summation of the gains (eye velocity/head velocity) obtained for rotations about the pure yaw and roll head axes. Thus, even when the orientation of Listing's plane and eye position in the orbit are fixed, the axis of eye rotation during the VOR reflects a compromise between the requirements of Listing's law and a

  17. Glaucoma diagnostic capacity of optic nerve head haemoglobin measures compared with spectral domain OCT and HRT III confocal tomography.

    PubMed

    Mendez-Hernandez, Carmen; Rodriguez-Uña, Ignacio; Gonzalez-de-la Rosa, Manuel; Arribas-Pardo, Paula; Garcia-Feijoo, Julian

    2016-11-01

    The computer program laguna onhe determines optic nerve head haemoglobin (ONH Hb) on retinal photographs based on detecting colour differences. This study compares the diagnostic capacity of Laguna ONhE with that of spectral domain optical coherence tomography (OCT) and confocal tomography (HRT III). In a prospective, observational, cross-sectional study, glaucomatous (n = 66) and healthy (n = 52) eyes were examined by Spectralis OCT, HRT III and Laguna ONhE. The following Laguna ONhE variables were determined: ONH Hb across the vertical disc diameter (8&20 Hb), estimated cup-disc ratio (C/D) and the glaucoma discriminant function (GDF), which combines the slope of Hb amount with the mean in 8&20 Hb. The three diagnostic methods were compared by calculating areas under ROC curves (AUCs). Correlations between variables were assessed through Spearman's rho coefficient. Areas under ROC curves (AUCs) were 0.785 (95% CI: 0.700-0.863) for GDF, 0.807 (95% CI: 0.730-0.883) for OCT retinal nerve fibre layer thickness (OCT-RNFL) and 0.714 (95% CI: 0.618-0.810) and 0.721 (95% CI: 0.628-0.815) for the HRT III variable GPS (glaucoma probability score) and vertical C/D ratio, respectively. Glaucoma discriminant function (GDF) was correlated with OCT-RNFL (0.587, p 0.001; 0.507, p 0.045; and -0.119, p 0.713 for mild, moderate and advanced glaucoma, respectively), mostly so with inferior OCT-RNFL (0.622; p < 0.001). Glaucoma discriminant function (GDF)-HRT III correlations were lower (rim area 0.471, p < 0.0001; rim/disc area 0.426, p < 0.0001; vertical C/D -0.413, p < 0.0001; GPS -0.408, p < 0.0001; rim volume 0.341, p < 0.0001). Similar diagnostic power was observed for Laguna ONhE, Spectralis OCT and HRT III. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  18. Increased head circumference

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003305.htm Increased head circumference To use the sharing features on this page, please enable JavaScript. Increased head circumference is when the measured distance around the widest ...

  19. Three-dimensional Optical Coherence Tomography Imaging and Treatment of Glaucomatous Optic Nerve Head Defects Associated with Schisis-like Maculopathy

    PubMed Central

    Öztaş, Zafer; Menteş, Jale; Ateş, Halil; Nalçacı, Serhad

    2017-01-01

    We present the three-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) findings of schisis-like maculopathy associated with structural changes of the optic nerve (ON) head as well as the treatment outcomes of a case of advanced glaucoma. In addition to ophthalmological examination, B-scan and 3D-SD-OCT images of the ON head, peripapillary retina, and the macula were obtained. The B-scan images only detected typical retinoschisis findings. However, the 3D-SD-OCT images of the ON head revealed defects of various sizes, shapes, and depths at the outer wall of the prelaminar and laminar regions of the ON canal. The 3D images were able to establish that these defects were both adjacent to and interconnected with the retinal layers. The patient successfully received 3D-SD-OCT-guided thermal laser treatment that is used in congenital optic disc pits complicated with macular schisis. In brief, 3D-SD-OCT is very useful for demonstrating the ON head defects that can lead to schisis-like maculopathy in cases of advanced glaucoma. PMID:28405489

  20. Missouri: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Missouri's Early Head Start/Child Care Partnership Project expands access to Early Head Start (EHS) services for children birth to age 3 by developing partnerships between federal Head Start, EHS contractors, and child care providers. Head Start and EHS contractors that participate in the initiative provide services through community child care…

  1. Autoinhibition of a calmodulin-dependent calcium pump involves a structure in the stalk that connects the transmembrane domain to the ATPase catalytic domain

    NASA Technical Reports Server (NTRS)

    Curran, A. C.; Hwang, I.; Corbin, J.; Martinez, S.; Rayle, D.; Sze, H.; Harper, J. F.; Evans, M. L. (Principal Investigator)

    2000-01-01

    The regulation of Ca(2+)-pumps is important for controlling [Ca(2+)] in the cytosol and organelles of all eukaryotes. Here, we report a genetic strategy to identify residues that function in autoinhibition of a novel calmodulin-activated Ca(2+)-pump with an N-terminal regulatory domain (isoform ACA2 from Arabidopsis). Mutant pumps with constitutive activity were identified by complementation of a yeast (K616) deficient in two Ca(2+)-pumps. Fifteen mutations were found that disrupted a segment of the N-terminal autoinhibitor located between Lys(23) and Arg(54). Three mutations (E167K, D219N, and E341K) were found associated with the stalk that connects the ATPase catalytic domain (head) and with the transmembrane domain. Enzyme assays indicated that the stalk mutations resulted in calmodulin-independent activity, with V(max), K(mATP), and K(mCa(2+)) similar to that of a pump in which the N-terminal autoinhibitor had been deleted. A highly conservative substitution at Asp(219) (D219E) still produced a deregulated pump, indicating that the autoinhibitory structure in the stalk is highly sensitive to perturbation. In plasma membrane H(+)-ATPases from yeast and plants, similarly positioned mutations resulted in hyperactive pumps. Together, these results suggest that a structural feature of the stalk is of general importance in regulating diverse P-type ATPases.

  2. Ice hockey shoulder pad design and the effect on head response during shoulder-to-head impacts.

    PubMed

    Richards, Darrin; Ivarsson, B Johan; Scher, Irving; Hoover, Ryan; Rodowicz, Kathleen; Cripton, Peter

    2016-11-01

    Ice hockey body checks involving direct shoulder-to-head contact frequently result in head injury. In the current study, we examined the effect of shoulder pad style on the likelihood of head injury from a shoulder-to-head check. Shoulder-to-head body checks were simulated by swinging a modified Hybrid-III anthropomorphic test device (ATD) with and without shoulder pads into a stationary Hybrid-III ATD at 21 km/h. Tests were conducted with three different styles of shoulder pads (traditional, integrated and tethered) and without shoulder pads for the purpose of control. Head response kinematics for the stationary ATD were measured. Compared to the case of no shoulder pads, the three different pad styles significantly (p < 0.05) reduced peak resultant linear head accelerations of the stationary ATD by 35-56%. The integrated shoulder pads reduced linear head accelerations by an additional 18-21% beyond the other two styles of shoulder pads. The data presented here suggest that shoulder pads can be designed to help protect the head of the struck player in a shoulder-to-head check.

  3. Assessment of the effectiveness of head only and back-of-the-head electrical stunning of chickens

    PubMed Central

    Gibson, T. J.; Taylor, A. H.; Gregory, N. G.

    2016-01-01

    Abstract The study assesses the effectiveness of reversible head-only and back-of-the-head electrical stunning of chickens using 130–950 mA per bird at 50 Hz AC.Three trials were conducted to compare both stunning systems: (a) behavioural assessment of return of consciousness, (b) insensibility to thermal pain, and (c) assessment of return of brain activity with visually evoked potentials (VEPs).Assessment of behaviour suggested that the period of unconsciousness following head-only electrical stunning was shorter in hens compared to broilers.Stunning across the back-of-the-head delayed the time to return of brainstem function compared to stunning with standard head-only electrodes. Additionally, back-of-the-head stunning produced a more prolonged period of electroanalgesia compared to head-only.Based on examination of return of brain function with VEPs in hens, back-of-the-head stunning produced a shorter-lasting stun than standard head-only. However, even for standard head-only, the stun was notably shorter than previously reported. In some birds, brain function had returned within 9 s after the end of stunning.The results suggest that some birds may recover consciousness prior to or during the neck cut. Based on these findings, back-of-the-head stunning and standard head-only stunning of hens should not be recommended without further development. PMID:27023411

  4. Head Start Facilities Manual.

    ERIC Educational Resources Information Center

    Research Assessment Management, Inc., Silver Spring, MD.

    A quality Head Start facility should provide a physical environment responsive both to the needs of the children and families served and to the needs of staff, volunteers, and community agencies that share space with Head Start. This manual is a tool for Head Start grantees and delegate agencies for assessing existing facilities, making…

  5. Fostering High-Quality Teaching with an Enriched Curriculum and Professional Development Support: The Head Start REDI Program

    PubMed Central

    Domitrovich, Celene E.; Gest, Scott D.; Gill, Sukhdeep; Bierman, Karen L.; Welsh, Janet; Jones, Damon

    2017-01-01

    This randomized controlled trial tested whether teaching quality in Head Start classrooms could be improved with the addition of evidence-based curriculum components targeting emergent language/literacy and social-emotional development and the provision of associated professional development support. Participants were lead and assistant teachers in 44 Head Start classrooms. Teachers received 4 days of workshop training along with weekly in-class support from a mentor teacher. End-of-year observations indicated that, compared to the control group, intervention teachers talked with children more frequently and in more cognitively complex ways, established a more positive classroom climate, and used more preventive behavior management strategies. Results supported the conclusion that enriched curriculum components and professional development support can produce improvements in multiple domains of teaching quality. PMID:29081534

  6. Long single [alpha]-helical tail domains bridge the gap between structure and function of myosin VI

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Spink, Benjamin J.; Sivaramakrishnan, Sivaraj; Lipfert, Jan

    2008-09-29

    Myosin VI has challenged the lever arm hypothesis of myosin movement because of its ability to take {approx}36-nm steps along actin with a canonical lever arm that seems to be too short to allow such large steps. Here we demonstrate that the large step of dimeric myosin VI is primarily made possible by a medial tail in each monomer that forms a rare single {alpha}-helix of {approx}10 nm, which is anchored to the calmodulin-bound IQ domain by a globular proximal tail. With the medial tail contributing to the {approx}36-nm step, rather than dimerizing as previously proposed, we show that themore » cargo binding domain is the dimerization interface. Furthermore, the cargo binding domain seems to be folded back in the presence of the catalytic head, constituting a potential regulatory mechanism that inhibits dimerization.« less

  7. Head CT scan

    MedlinePlus

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... conditions: Birth (congenital) defect of the head or brain Brain infection Brain tumor Buildup of fluid inside ...

  8. Information Technology Governance Domains in Hospitals: A Case Study in Iran

    PubMed Central

    Shahi, Mehraban; Sadoughi, Farahnaz; Ahmadi, Maryam

    2015-01-01

    IT governance is a set of organizational structures ensuring decision-making rights and responsibilities with regard to the organization’s IT assets. This qualitative study was carried out to identify the IT governance domains in teaching hospitals affiliated to Iran University of Medical Sciences. There were 10 heads of IT departments and 10 hospital directors. Semi structured interviews used for data collection. To analyze the data content analysis was applied. All the interviewees (100%) believed that decisions upon hospital software needs could be made in a decentralized fashion by the IT department of the university. Most of the interviewees (90%) believed that there were policies for logistics and maintenance of networks, purchase and maintenance, standards and general policies in the direction of the policies of the ministry of health and medical education. About 80% of the interviewees believed that the current emphasis of the hospital’s IT unit and the hospital management for outsourcing of services were in the format of specialized contracts and under supervision of the university Statistic and IT department. A hospital strategic committee is an official organizational group consisting of hospital executives, heads of IT and multiple functional areas and business units in a hospital. In this committee, “the head of hospital” acts as the director of IT activities and ensures that IT strategies are alignment with the hospital business strategies. PMID:25948446

  9. Information technology governance domains in hospitals: a case study in Iran.

    PubMed

    Shahi, Mehraban; Sadoughi, Farahnaz; Ahmadi, Maryam

    2014-11-30

    IT governance is a set of organizational structures ensuring decision-making rights and responsibilities with regard to the organization's IT assets. This qualitative study was carried out to identify the IT governance domains in teaching hospitals affiliated to Iran University of Medical Sciences. There were 10 heads of IT departments and 10 hospital directors. Semi structured interviews used for data collection. To analyze the data content analysis was applied. All the interviewees (100%) believed that decisions upon hospital software needs could be made in a decentralized fashion by the IT department of the university. Most of the interviewees (90%) believed that there were policies for logistics and maintenance of networks, purchase and maintenance, standards and general policies in the direction of the policies of the ministry of health and medical education. About 80% of the interviewees believed that the current emphasis of the hospital's IT unit and the hospital management for outsourcing of services were in the format of specialized contracts and under supervision of the university Statistic and IT department. A hospital strategic committee is an official organizational group consisting of hospital executives, heads of IT and multiple functional areas and business units in a hospital. In this committee, "the head of hospital" acts as the director of IT activities and ensures that IT strategies are alignment with the hospital business strategies.

  10. Hillslope to fluvial process domain transitions in headwater catchments

    NASA Astrophysics Data System (ADS)

    Williams, Karen Mary

    mapped channel heads and hollows and spatial regions of process transitions. Subreaches of arguably alluvial channel conditions were also identified in power spectra. However, extrinsic forcing limits ability to detect a clear transition from colluvial to fully alluvial conditions. Headwater catchments present a mosaic of process domains, in large determined by local structure and lithology. However, process domain transitions appear detectable and statistically, though not deterministically, predictable, irrespective of setting.

  11. Family Connections: Helping Early Head Start/Head Start Staff and Parents Address Mental Health Challenges

    ERIC Educational Resources Information Center

    Beardslee, William R.; Avery, Mary Watson; Ayoub, Catherine; Watts, Caroline L.

    2009-01-01

    Early Head Start/Head Start teachers and staff encounter parents who have wrestled with depression and other adversities every day. This article describes an innovative program of trainings for and consultation to Early Head Start/Head Start staff to help them effectively deal with mental heath challenges faced by parents and children. The program…

  12. Conformational and functional analysis of the C-terminal globular head of the reovirus cell attachment protein.

    PubMed

    Duncan, R; Horne, D; Strong, J E; Leone, G; Pon, R T; Yeung, M C; Lee, P W

    1991-06-01

    We have been investigating structure-function relationships in the reovirus cell attachment protein sigma 1 using various deletion mutants and protease analysis. In the present study, a series of deletion mutants were constructed which lacked 90, 44, 30, 12, or 4 amino acids from the C-terminus of the 455-amino acid-long reovirus type 3 (T3) sigma 1 protein. The full-length and truncated sigma 1 proteins were expressed in an in vitro transcription/translation system and assayed for L cell binding activity. It was found that the removal of as few as four amino acids from the C-terminus drastically affected the cell binding function of the sigma 1 protein. The C-terminal-truncated proteins were further characterized using trypsin, chymotrypsin, and monoclonal and polyclonal antibodies. Our results indicated that the C-terminal portions of the mutant proteins were misfolded, leading to a loss in cell binding function. The N-terminal fibrous tail of the proteins was unaffected by the deletions as was sigma 1 oligomerization, further illustrating the discrete structural and functional roles of the N- and C-terminal domains of sigma 1. In an attempt to identify smaller, functional peptides, full-length sigma 1 expressed in vitro was digested with trypsin and subsequently with chymotrypsin under various conditions. The results clearly demonstrated the highly stable nature of the C-terminal globular head of sigma 1, even when separated from the N-terminal fibrous tail. We concluded that: (1) the C-terminal globular head of sigma 1 exists as a compact, protease-resistant oligomeric structure; (2) an intact C-terminus is required for proper head folding and generation of the conformationally dependent cell binding domain.

  13. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly. 572.192 Section 572.192... Test Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

  14. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly. 572.192 Section 572.192... Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180-1000...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

  15. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly. 572.192 Section 572.192... Test Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

  16. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly. 572.192 Section 572.192... Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180-1000...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

  17. 49 CFR 572.192 - Head assembly.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.192 Section 572.192... Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180-1000...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

  18. An objective frequency domain method for subsurface characterisation using Earth and atmospheric tides

    NASA Astrophysics Data System (ADS)

    Cuthbert, M. O.; Acworth, I. R.; Halloran, L. J. S.; Rau, G. C.; Bernadi, T. L.

    2017-12-01

    It has long been recognised that hydraulic properties can be derived from the response of piezometric heads to tidal loadings. However, there is a degree of subjectivity in existing graphical approaches most commonly used to calculate barometric efficiency leading to uncertainties in derived values of compressible storage. Here we demonstrate a novel approach to remove these uncertainties by objectively deriving the barometric efficiency from groundwater hydraulic head responses using a frequency domain method. We take advantage of the presence of worldwide and ubiquitous atmospheric tide fluctuations which occur at 2 cycles per day (cpd). First we use a Fourier transform to calculate the amplitudes of the 2 cpd signals from co-located atmospheric pressure and hydraulic head time series measurements. Next we show how the Earth tide response at the same frequency can be quantified and removed so that this effect does not interfere with the calculation of the barometric efficiency. Finally, the ratio of the amplitude of the response at 2 cpd of hydraulic head to atmospheric pressure is used to quantify the barometric efficiency. This new method allows an objective quantification using `passive' in situ monitoring rather than resorting to aquifer pumping or laboratory tests. The minimum data requirements are 15 days duration of 6-hourly hydraulic head and atmospheric pressure measurements, and modelled Earth tide records which are readily conducted using freely available software. The new approach allows for a rapid and cost-effective alternative to traditional methods of estimating aquifer compressible storage properties without the subjectivity of existing approaches, and will be of importance to improving the spatial coverage of subsurface characterisation for groundwater resource evaluation and land subsidence assessment.

  19. A programmable DNA origami nanospring that reveals force-induced adjacent binding of myosin VI heads

    PubMed Central

    Iwaki, M.; Wickham, S. F.; Ikezaki, K.; Yanagida, T.; Shih, W. M.

    2016-01-01

    Mechanosensitive biological nanomachines such as motor proteins and ion channels regulate diverse cellular behaviour. Combined optical trapping with single-molecule fluorescence imaging provides a powerful methodology to clearly characterize the mechanoresponse, structural dynamics and stability of such nanomachines. However, this system requires complicated experimental geometry, preparation and optics, and is limited by low data-acquisition efficiency. Here we develop a programmable DNA origami nanospring that overcomes these issues. We apply our nanospring to human myosin VI, a mechanosensory motor protein, and demonstrate nanometre-precision single-molecule fluorescence imaging of the individual motor domains (heads) under force. We observe force-induced transitions of myosin VI heads from non-adjacent to adjacent binding, which correspond to adapted roles for low-load and high-load transport, respectively. Our technique extends single-molecule studies under force and clarifies the effect of force on biological processes. PMID:27941751

  20. A programmable DNA origami nanospring that reveals force-induced adjacent binding of myosin VI heads.

    PubMed

    Iwaki, M; Wickham, S F; Ikezaki, K; Yanagida, T; Shih, W M

    2016-12-12

    Mechanosensitive biological nanomachines such as motor proteins and ion channels regulate diverse cellular behaviour. Combined optical trapping with single-molecule fluorescence imaging provides a powerful methodology to clearly characterize the mechanoresponse, structural dynamics and stability of such nanomachines. However, this system requires complicated experimental geometry, preparation and optics, and is limited by low data-acquisition efficiency. Here we develop a programmable DNA origami nanospring that overcomes these issues. We apply our nanospring to human myosin VI, a mechanosensory motor protein, and demonstrate nanometre-precision single-molecule fluorescence imaging of the individual motor domains (heads) under force. We observe force-induced transitions of myosin VI heads from non-adjacent to adjacent binding, which correspond to adapted roles for low-load and high-load transport, respectively. Our technique extends single-molecule studies under force and clarifies the effect of force on biological processes.

  1. Structural determinants of phosphoinositide selectivity in splice variants of Grp1 family PH domains

    PubMed Central

    Cronin, Thomas C; DiNitto, Jonathan P; Czech, Michael P; Lambright, David G

    2004-01-01

    The pleckstrin homology (PH) domains of the homologous proteins Grp1 (general receptor for phosphoinositides), ARNO (Arf nucleotide binding site opener), and Cytohesin-1 bind phosphatidylinositol (PtdIns) 3,4,5-trisphosphate with unusually high selectivity. Remarkably, splice variants that differ only by the insertion of a single glycine residue in the β1/β2 loop exhibit dual specificity for PtdIns(3,4,5)P3 and PtdIns(4,5)P2. The structural basis for this dramatic specificity switch is not apparent from the known modes of phosphoinositide recognition. Here, we report crystal structures for dual specificity variants of the Grp1 and ARNO PH domains in either the unliganded form or in complex with the head groups of PtdIns(4,5)P2 and PtdIns(3,4,5)P3. Loss of contacts with the β1/β2 loop with no significant change in head group orientation accounts for the significant decrease in PtdIns(3,4,5)P3 affinity observed for the dual specificity variants. Conversely, a small increase rather than decrease in affinity for PtdIns(4,5)P2 is explained by a novel binding mode, in which the glycine insertion alleviates unfavorable interactions with the β1/β2 loop. These observations are supported by a systematic mutational analysis of the determinants of phosphoinositide recognition. PMID:15359279

  2. American Head and Neck Society

    MedlinePlus

    American Head & Neck Society Mission Statement: Advance Education, Research, and Quality of Care for the head and neck oncology patient. American Head & Neck Society | AHNS The mission of the AHNS is ...

  3. Site-directed spin labeling reveals a conformational switch in the phosphorylation domain of smooth muscle myosin.

    PubMed

    Nelson, Wendy D; Blakely, Sarah E; Nesmelov, Yuri E; Thomas, David D

    2005-03-15

    We have used site-directed spin labeling and EPR spectroscopy to detect structural changes within the regulatory light chain (RLC) of smooth muscle myosin upon phosphorylation. Smooth muscle contraction is activated by phosphorylation of S19 on RLC, but the structural basis of this process is unknown. There is no crystal structure containing a phosphorylated RLC, and there is no crystal structure for the N-terminal region of any RLC. Therefore, we have prepared single-Cys mutations throughout RLC, exchanged each mutant onto smooth muscle heavy meromyosin, verified normal regulatory function, and used EPR to determine dynamics and solvent accessibility at each site. A survey of spin-label sites throughout the RLC revealed that only the N-terminal region (first 24 aa) shows a significant change in dynamics upon phosphorylation, with most of the first 17 residues showing an increase in rotational amplitude. Therefore, we focused on this N-terminal region. Additional structural information was obtained from the pattern of oxygen accessibility along the sequence. In the absence of phosphorylation, little or no periodicity was observed, suggesting a lack of secondary structural order in this region. However, phosphorylation induced a strong helical pattern (3.6-residue periodicity) in the first 17 residues, while increasing accessibility throughout the first 24 residues. We have identified a domain within RLC, the N-terminal phosphorylation domain, in which phosphorylation increases helical order, internal dynamics, and accessibility. These results support a model in which this disorder-to-order transition within the phosphorylation domain results in decreased head-head interactions, activating myosin in smooth muscle.

  4. Vomiting--is this a good indication for CT head scans in patients with minor head injury?

    PubMed

    Bainbridge, J; Khirwadkar, H; Hourihan, M D

    2012-02-01

    The National Institute for Health and Clinical Excellence head injury guidelines advise CT imaging within 1 h if there is more than one episode of vomiting post-head injury in adults and three or more episodes in children. Since the guideline publication, studies have found that, following head injury, vomiting alone is associated with an abnormal CT head scan in 13-45% of cases. CT head scan requests referred from the emergency department between 1 May 2009 and 30 April 2010 were retrospectively reviewed. Patients with vomiting as the sole indication for an "immediate" CT head scan performed within 1 h were included in the study. Reports produced by experienced neuroradiologists were reviewed and the detection of significant head injury was noted. There were 1264 CT head scans performed during our study period. 151 (124 adults, 27 children) were indicated owing to vomiting following head injury. 5 of the 124 adult scans and 1 of the 27 paediatric scans showed an abnormal finding, giving positive predictive values (PPV) of 4% and 3.7%, respectively. None of these patients required either acute or delayed neurosurgical intervention. In our experience, vomiting alone has a PPV of 4% for significant head injury in adults. However, none of these injuries were serious enough to warrant acute or delayed intervention. Given these findings, vomiting following head injury is a reasonable indication for a CT head scan; however, as none of the patients required acute intervention, we suggest that these scans do not usually need to be performed within 1 h of request.

  5. Domain atrophy creates rare cases of functional partial protein domains.

    PubMed

    Prakash, Ananth; Bateman, Alex

    2015-04-30

    Protein domains display a range of structural diversity, with numerous additions and deletions of secondary structural elements between related domains. We have observed a small number of cases of surprising large-scale deletions of core elements of structural domains. We propose a new concept called domain atrophy, where protein domains lose a significant number of core structural elements. Here, we implement a new pipeline to systematically identify new cases of domain atrophy across all known protein sequences. The output of this pipeline was carefully checked by hand, which filtered out partial domain instances that were unlikely to represent true domain atrophy due to misannotations or un-annotated sequence fragments. We identify 75 cases of domain atrophy, of which eight cases are found in a three-dimensional protein structure and 67 cases have been inferred based on mapping to a known homologous structure. Domains with structural variations include ancient folds such as the TIM-barrel and Rossmann folds. Most of these domains are observed to show structural loss that does not affect their functional sites. Our analysis has significantly increased the known cases of domain atrophy. We discuss specific instances of domain atrophy and see that there has often been a compensatory mechanism that helps to maintain the stability of the partial domain. Our study indicates that although domain atrophy is an extremely rare phenomenon, protein domains under certain circumstances can tolerate extreme mutations giving rise to partial, but functional, domains.

  6. CT Perfusion of the Head

    MedlinePlus

    ... News Physician Resources Professions Site Index A-Z CT Perfusion of the Head Computed tomography (CT) perfusion ... of CT Perfusion of the Head? What is CT Perfusion of the Head? Computed tomography (CT) perfusion ...

  7. Assessment of parental tooth-brushing following instruction with single-headed and triple-headed toothbrushes.

    PubMed

    Telishevesky, Yoel S; Levin, Liran; Ashkenazi, Malka

    2012-01-01

    The purpose of this study was to evaluate the effect of toothbrush design on the ability of parents to effectively brush their children's teeth. Parents of children (mean age=5.1±0.75 years old) from 4 kindergarten schools were randomly assigned to receive instruction in brushing their children's teeth using a manual single-headed toothbrush (2 schools) or a triple-headed toothbrush (2 schools). The parents' ability to brush their children's teeth was evaluated according to a novel toothbrush performing skill index (Ashkenazi Index), based on 2 criteria: (1) placement of the toothbrush on each tooth segment to be brushed ("reach"); and (2) completion of enough strokes on each segment ("stay"). One month after instruction, tooth-brushing ability was re-evaluated and plaque index of the children's teeth was assessed. One month after instruction, parents using the triple-headed toothbrush received significantly higher scores on the tooth-brushing performance index (~86%), than did those in the single-headed group (~61%; P=.001). The plaque index was significantly higher in the single-headed group (0.97±0.38) vs the triple-headed group (0.72±0.29; P<.01). The tooth-brushing performance index correlated negatively with the plaque index (P<.01). A triple-headed toothbrush promotes more consistent tooth-brushing by parents than does a single-headed toothbrush.

  8. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

  9. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

  10. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

  11. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

  12. 49 CFR 572.112 - Head assembly.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

  13. Exploiting domain information for Word Sense Disambiguation of medical documents.

    PubMed

    Stevenson, Mark; Agirre, Eneko; Soroa, Aitor

    2012-01-01

    Current techniques for knowledge-based Word Sense Disambiguation (WSD) of ambiguous biomedical terms rely on relations in the Unified Medical Language System Metathesaurus but do not take into account the domain of the target documents. The authors' goal is to improve these methods by using information about the topic of the document in which the ambiguous term appears. The authors proposed and implemented several methods to extract lists of key terms associated with Medical Subject Heading terms. These key terms are used to represent the document topic in a knowledge-based WSD system. They are applied both alone and in combination with local context. A standard measure of accuracy was calculated over the set of target words in the widely used National Library of Medicine WSD dataset. The authors report a significant improvement when combining those key terms with local context, showing that domain information improves the results of a WSD system based on the Unified Medical Language System Metathesaurus alone. The best results were obtained using key terms obtained by relevance feedback and weighted by inverse document frequency.

  14. Systematic evaluation of a time-domain Monte Carlo fitting routine to estimate the adult brain optical properties

    NASA Astrophysics Data System (ADS)

    Selb, Juliette; Ogden, Tyler M.; Dubb, Jay; Fang, Qianqian; Boas, David A.

    2013-03-01

    Time-domain near-infrared spectroscopy (TD-NIRS) offers the ability to measure the absolute baseline optical properties of a tissue. Specifically, for brain imaging, the robust assessment of cerebral blood volume and oxygenation based on measurement of cerebral hemoglobin concentrations is essential for reliable cross-sectional and longitudinal studies. In adult heads, these baseline measurements are complicated by the presence of thick extra-cerebral tissue (scalp, skull, CSF). A simple semi-infinite homogeneous model of the head has proven to have limited use because of the large errors it introduces in the recovered brain absorption. Analytical solutions for layered media have shown improved performance on Monte-Carlo simulated data and layered phantom experiments, but their validity on real adult head data has never been demonstrated. With the advance of fast Monte Carlo approaches based on GPU computation, numerical methods to solve the radiative transfer equation become viable alternatives to analytical solutions of the diffusion equation. Monte Carlo approaches provide the additional advantage to be adaptable to any geometry, in particular more realistic head models. The goals of the present study were twofold: (1) to implement a fast and flexible Monte Carlo-based fitting routine to retrieve the brain optical properties; (2) to characterize the performances of this fitting method on realistic adult head data. We generated time-resolved data at various locations over the head, and fitted them with different models of light propagation: the homogeneous analytical model, and Monte Carlo simulations for three head models: a two-layer slab, the true subject's anatomy, and that of a generic atlas head. We found that the homogeneous model introduced a median 20 to 25% error on the recovered brain absorption, with large variations over the range of true optical properties. The two-layer slab model only improved moderately the results over the homogeneous one. On

  15. Analysis of two colliding fractionally damped spherical shells in modelling blunt human head impacts

    NASA Astrophysics Data System (ADS)

    Rossikhin, Yury A.; Shitikova, Marina V.

    2013-06-01

    The collision of two elastic or viscoelastic spherical shells is investigated as a model for the dynamic response of a human head impacted by another head or by some spherical object. Determination of the impact force that is actually being transmitted to bone will require the model for the shock interaction of the impactor and human head. This model is indended to be used in simulating crash scenarios in frontal impacts, and provide an effective tool to estimate the severity of effect on the human head and to estimate brain injury risks. The model developed here suggests that after the moment of impact quasi-longitudinal and quasi-transverse shock waves are generated, which then propagate along the spherical shells. The solution behind the wave fronts is constructed with the help of the theory of discontinuities. It is assumed that the viscoelastic features of the shells are exhibited only in the contact domain, while the remaining parts retain their elastic properties. In this case, the contact spot is assumed to be a plane disk with constant radius, and the viscoelastic features of the shells are described by the fractional derivative standard linear solid model. In the case under consideration, the governing differential equations are solved analytically by the Laplace transform technique. It is shown that the fractional parameter of the fractional derivative model plays very important role, since its variation allows one to take into account the age-related changes in the mechanical properties of bone.

  16. Exploding head syndrome.

    PubMed

    Sharpless, Brian A

    2014-12-01

    Exploding head syndrome is characterized by the perception of abrupt, loud noises when going to sleep or waking up. They are usually painless, but associated with fear and distress. In spite of the fact that its characteristic symptomatology was first described approximately 150 y ago, exploding head syndrome has received relatively little empirical and clinical attention. Therefore, a comprehensive review of the scientific literature using Medline, PsycINFO, Google Scholar, and PubMed was undertaken. After first discussing the history, prevalence, and associated features, the available polysomnography data and five main etiological theories for exploding head syndrome are summarized. None of these theories has yet reached dominance in the field. Next, the various methods used to assess and treat exploding head syndrome are discussed, as well as the limited outcome data. Finally, recommendations for future measure construction, treatment options, and differential diagnosis are provided. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Countermanding eye-head gaze shifts in humans: marching orders are delivered to the head first.

    PubMed

    Corneil, Brian D; Elsley, James K

    2005-07-01

    The countermanding task requires subjects to cancel a planned movement on appearance of a stop signal, providing insights into response generation and suppression. Here, we studied human eye-head gaze shifts in a countermanding task with targets located beyond the horizontal oculomotor range. Consistent with head-restrained saccadic countermanding studies, the proportion of gaze shifts on stop trials increased the longer the stop signal was delayed after target presentation, and gaze shift stop-signal reaction times (SSRTs: a derived statistic measuring how long it takes to cancel a movement) averaged approximately 120 ms across seven subjects. We also observed a marked proportion of trials (13% of all stop trials) during which gaze remained stable but the head moved toward the target. Such head movements were more common at intermediate stop signal delays. We never observed the converse sequence wherein gaze moved while the head remained stable. SSRTs for head movements averaged approximately 190 ms or approximately 70-75 ms longer than gaze SSRTs. Although our findings are inconsistent with a single race to threshold as proposed for controlling saccadic eye movements, movement parameters on stop trials attested to interactions consistent with a race model architecture. To explain our data, we tested two extensions to the saccadic race model. The first assumed that gaze shifts and head movements are controlled by parallel but independent races. The second model assumed that gaze shifts and head movements are controlled by a single race, preceded by terminal ballistic intervals not under inhibitory control, and that the head-movement branch is activated at a lower threshold. Although simulations of both models produced acceptable fits to the empirical data, we favor the second alternative as it is more parsimonious with recent findings in the oculomotor system. Using the second model, estimates for gaze and head ballistic intervals were approximately 25 and 90 ms

  18. Dysphagia after nonsurgical head and neck cancer treatment: patients' perspectives.

    PubMed

    Wilson, Janet A; Carding, Paul N; Patterson, Joanne M

    2011-11-01

    Assess patients' perspectives on the severity, time course, and relative importance of swallowing deficit before and after (chemo)radiotherapy for head and neck cancer. Before-and-after cohort study. Head and neck cancer UK multidisciplinary clinic. A total of 167 patients with a primary cancer, mostly laryngopharyngeal, completed the MD Anderson Dysphagia Index (MDADI) and the University of Washington Quality of Life Questionnaire (UWQOL) before treatment and at 3, 6, and 12 months. Pretreatment swallowing, age, gender, and tumor site and stage were assessed. Statistical methods used were Mann-Whitney, analysis of variance, and logistic regression. There was a sharp deterioration in swallowing on average by 18%, from before treatment to 3 months post treatment (mean difference in MDADI score = 14.5; P < .001). Treatment schedule, pretreatment score, and age accounted for 37% of the variance in 3-month posttreatment MDADI scores. There was then little improvement from 3 to 12 months. Patients treated with only 50-Gy radiotherapy reported significantly less dysphagia at 1 year than patients receiving higher doses or combined chemoradiation (P < .001). Swallowing was the most commonly prioritized of the 12 UWQOL domains both before and after therapy. The MDADI and UWQOL scores were strongly correlated: ρ > 0.69. Swallowing is a top priority before and after treatment for the vast majority of patients with head and neck cancer. Swallowing deteriorates significantly posttreatment (P < .001). Treatment intensity, younger age, and lower pretreatment scores predict long-term dysphagia. After chemoradiation, there is little improvement from 3 to 12 months.

  19. Transforming properties of the Huntingtin interacting protein 1/ platelet-derived growth factor beta receptor fusion protein.

    PubMed

    Ross, T S; Gilliland, D G

    1999-08-06

    We have previously reported that the Huntingtin interacting protein 1 (HIP1) gene is fused to the platelet-derived growth factor beta receptor (PDGFbetaR) gene in a patient with chronic myelomonocytic leukemia. We now show that HIP1/PDGFbetaR oligomerizes, is constitutively tyrosine-phosphorylated, and transforms the murine hematopoietic cell line, Ba/F3, to interleukin-3-independent growth. A kinase-inactive mutant is neither tyrosine-phosphorylated nor able to transform Ba/F3 cells. Oligomerization and kinase activation required the 55-amino acid carboxyl-terminal TALIN homology region but not the leucine zipper domain. Tyrosine phosphorylation of a 130-kDa protein and STAT5 correlates with transformation in cells expressing HIP1/PDGFbetaR and related mutants. A deletion mutant fusion protein that contains only the TALIN homology region of HIP1 fused to PDGFbetaR is incapable of transforming Ba/F3 cells and does not tyrosine-phosphorylate p130 or STAT5, although it is itself constitutively tyrosine-phosphorylated. We have also analyzed cells expressing Tyr --> Phe mutants of HIP1/PDGFbetaR in the known PDGFbetaR SH2 docking sites and report that none of these sites are necessary for STAT5 activation, p130 phosphorylation, or Ba/F3 transformation. The correlation of factor-independent growth of hematopoietic cells with p130 and STAT5 phosphorylation/activation in both the HIP1/PDGFbetaR Tyr --> Phe and deletion mutational variants suggests that both STAT5 and p130 are important for transformation mediated by HIP1/PDGFbetaR.

  20. Coiled-coil domain containing 42 (Ccdc42) is necessary for proper sperm development and male fertility in the mouse.

    PubMed

    Pasek, Raymond C; Malarkey, Erik; Berbari, Nicolas F; Sharma, Neeraj; Kesterson, Robert A; Tres, Laura L; Kierszenbaum, Abraham L; Yoder, Bradley K

    2016-04-15

    Spermiogenesis is the differentiation of spermatids into motile sperm consisting of a head and a tail. The head harbors a condensed elongated nucleus partially covered by the acrosome-acroplaxome complex. Defects in the acrosome-acroplaxome complex are associated with abnormalities in sperm head shaping. The head-tail coupling apparatus (HTCA), a complex structure consisting of two cylindrical microtubule-based centrioles and associated components, connects the tail or flagellum to the sperm head. Defects in the development of the HTCA cause sperm decapitation and disrupt sperm motility, two major contributors to male infertility. Here, we provide data indicating that mutations in the gene Coiled-coil domain containing 42 (Ccdc42) is associated with malformation of the mouse sperm flagella. In contrast to many other flagella and motile cilia genes, Ccdc42 expression is only observed in the brain and developing sperm. Male mice homozygous for a loss-of-function Ccdc42 allele (Ccdc42(KO)) display defects in the number and location of the HTCA, lack flagellated sperm, and are sterile. The testes enriched expression of Ccdc42 and lack of other phenotypes in mutant mice make it an ideal candidate for screening cases of azoospermia in humans. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Structure of the Fibrillin-1 N-Terminal Domains Suggests that Heparan Sulfate Regulates the Early Stages of Microfibril Assembly

    PubMed Central

    Yadin, David A.; Robertson, Ian B.; McNaught-Davis, Joanne; Evans, Paul; Stoddart, David; Handford, Penny A.; Jensen, Sacha A.; Redfield, Christina

    2013-01-01

    Summary The human extracellular matrix glycoprotein fibrillin-1 is the primary component of the 10- to 12-nm-diameter microfibrils, which perform key structural and regulatory roles in connective tissues. Relatively little is known about the molecular mechanisms of fibrillin assembly into microfibrils. Studies using recombinant fibrillin fragments indicate that an interaction between the N- and C-terminal regions drives head-to-tail assembly. Here, we present the structure of a fibrillin N-terminal fragment comprising the fibrillin unique N-terminal (FUN) and the first three epidermal growth factor (EGF)-like domains (FUN-EGF3). Two rod-like domain pairs are separated by a short, flexible linker between the EGF1 and EGF2 domains. We also show that the binding site for the C-terminal region spans multiple domains and overlaps with a heparin interaction site. These data suggest that heparan sulfate may sequester fibrillin at the cell surface via FUN-EGF3 prior to aggregation of the C terminus, thereby regulating microfibril assembly. PMID:24035709

  2. Deletion of the Tail Domain of the Kinesin-5 Cin8 Affects Its Directionality*

    PubMed Central

    Düselder, André; Fridman, Vladimir; Thiede, Christina; Wiesbaum, Alice; Goldstein, Alina; Klopfenstein, Dieter R.; Zaitseva, Olga; Janson, Marcel E.; Gheber, Larisa; Schmidt, Christoph F.

    2015-01-01

    The bipolar kinesin-5 motors are one of the major players that govern mitotic spindle dynamics. Their bipolar structure enables them to cross-link and slide apart antiparallel microtubules (MTs) emanating from the opposing spindle poles. The budding yeast kinesin-5 Cin8 was shown to switch from fast minus-end- to slow plus-end-directed motility upon binding between antiparallel MTs. This unexpected finding revealed a new dimension of cellular control of transport, the mechanism of which is unknown. Here we have examined the role of the C-terminal tail domain of Cin8 in regulating directionality. We first constructed a stable dimeric Cin8/kinesin-1 chimera (Cin8Kin), consisting of head and neck linker of Cin8 fused to the stalk of kinesin-1. As a single dimeric motor, Cin8Kin switched frequently between plus and minus directionality along single MTs, demonstrating that the Cin8 head domains are inherently bidirectional, but control over directionality was lost. We next examined the activity of a tetrameric Cin8 lacking only the tail domains (Cin8Δtail). In contrast to wild-type Cin8, the motility of single molecules of Cin8Δtail in high ionic strength was slow and bidirectional, with almost no directionality switches. Cin8Δtail showed only a weak ability to cross-link MTs in vitro. In vivo, Cin8Δtail exhibited bias toward the plus-end of the MTs and was unable to support viability of cells as the sole kinesin-5 motor. We conclude that the tail of Cin8 is not necessary for bidirectional processive motion, but is controlling the switch between plus- and minus-end-directed motility. PMID:25991727

  3. Structured Post-IQ Domain Governs Selectivity of Myosin X for Fascin-Actin Bundles*

    PubMed Central

    Nagy, Stanislav; Rock, Ronald S.

    2010-01-01

    Without guidance cues, cytoskeletal motors would traffic components to the wrong destination with disastrous consequences for the cell. Recently, we identified a motor protein, myosin X, that identifies bundled actin filaments for transport. These bundles direct myosin X to a unique destination, the tips of cellular filopodia. Because the structural and kinetic features that drive bundle selection are unknown, we employed a domain-swapping approach with the nonselective myosin V to identify the selectivity module of myosin X. We found a surprising role of the myosin X tail region (post-IQ) in supporting long runs on bundles. Moreover, the myosin X head is adapted for initiating processive runs on bundles. We found that the tail is structured and biases the orientation of the two myosin X heads because a targeted insertion that introduces flexibility in the tail abolishes selectivity. Together, these results suggest how myosin motors may manage to read cellular addresses. PMID:20538587

  4. Rate of Hanger Reflex Occurrence: Unexpected Head Rotation on Fronto-temporal Head Compression

    PubMed Central

    ASAHI, Takashi; SATO, Michi; KAJIMOTO, Hiroyuki; KOH, Masaki; KASHIWAZAKI, Daina; KURODA, Satoshi

    When the head is encircled with a wire clothes hanger and the unilateral fronto-temporal region is compressed, the head rotates unexpectedly. As the mechanism is unclear, however, we have temporarily named this phenomenon as the “hanger reflex.” We previously reported a case wherein this phenomenon was applied to treat cervical dystonia. Because little is known about this phenomenon, we determined how often this phenomenon is observed in healthy subjects. Study participants were 120 healthy Japanese adults (60 men and 60 women) aged 19–65 years. A wire clothes hanger was applied to each subject’s head. The longer side of the hanger was attached over the volunteer’s fronto-temporal regions on both sides of the head in succession (i.e., two applications per volunteer). We evaluated whether the subjects felt the sensation of head rotation by using a questionnaire. The sensation of head rotation was observed in 95.8% of subjects. There were five non-responders (4.2%). In 85.4% of the trials, head rotation was observed in the direction that coincided with the side compressed by the hanger. There were no differences in responses between genders. The incident rate of the hanger reflex was remarkably high and most likely represents a prevalent phenomenon in humans. The mechanism underlying the reflex remains unknown. Further research should be performed to elucidate the underlying causes of the hanger reflex, which represents a potential treatment for cervical dystonia. PMID:26119894

  5. Intercontinental Multi-Domain Monitoring for LHC with perfSONAR

    NASA Astrophysics Data System (ADS)

    Vicinanza, D.

    2012-12-01

    The Large Hadron Collider (LHC) is currently running at CERN in Geneva, Switzerland. Physicists are using LHC to recreate the conditions just after the Big Bang, by colliding two beams of particles and heavy ions head-on at very high energy. The project is generating more than 15 TB of raw data per year, plus 10 TB of “event summary data”. This data is sent out from CERN to eleven Tier 1 research centres in Europe, Asia, and North America using a multi-gigabits Optical Private Network (OPN), the LHCOPN. Tier 1 sites are then connected to 100+ academic and research institutions in the world (the Tier 2s) through a Multipoint to Multipoint network, the LHC Open Network Environment (LHCONE). Network monitoring on such complex network architecture to ensure robust and reliable operation is of crucial importance. The chosen approach for monitoring the OPN and ONE is based on the perfSONAR framework, which is designed for multi-domain monitoring environments. perfSONAR (www.perfsonar.net) is an infrastructure for performance monitoring data exchange between networks, making it easier to solve performance problems occurring between network measurement points interconnected through several network domains.

  6. Effects of Head Rotation and Head Tilt on Pharyngeal Pressure Events Using High Resolution Manometry.

    PubMed

    Kim, Cheol Ki; Ryu, Ju Seok; Song, Sun Hong; Koo, Jung Hoi; Lee, Kyung Duck; Park, Hee Sun; Oh, Yoongul; Min, Kyunghoon

    2015-06-01

    To observe changes in pharyngeal pressure during the swallowing process according to postures in normal individuals using high-resolution manometry (HRM). Ten healthy volunteers drank 5 mL of water twice while sitting in a neutral posture. Thereafter, they drank the same amount of water twice in the head rotation and head tilting postures. The pressure and time during the deglutition process for each posture were measured with HRM. The data obtained for these two postures were compared with those obtained from the neutral posture. The maximum pressure, area, rise time, and duration in velopharynx (VP) and tongue base (TB) were not affected by changes in posture. In comparison, the maximum pressure and the pre-upper esophageal sphincter (UES) maximum pressure of the lower pharynx in the counter-catheter head rotation posture were lower than those in the neutral posture. The lower pharynx pressure in the catheter head tilting posture was higher than that in the counter-catheter head tilting. The changes in the VP peak and epiglottis, VP and TB peaks, and the VP onset and post-UES time intervals were significant in head tilting and head rotation toward the catheter postures, as compared with neutral posture. The pharyngeal pressure and time parameter analysis using HRM determined the availability of head rotation as a compensatory technique for safe swallowing. Tilting the head smoothes the progress of food by increasing the pressure in the pharynx.

  7. Effects of Head Rotation and Head Tilt on Pharyngeal Pressure Events Using High Resolution Manometry

    PubMed Central

    Kim, Cheol Ki; Song, Sun Hong; Koo, Jung Hoi; Lee, Kyung Duck; Park, Hee Sun; Oh, Yoongul; Min, Kyunghoon

    2015-01-01

    Objective To observe changes in pharyngeal pressure during the swallowing process according to postures in normal individuals using high-resolution manometry (HRM). Methods Ten healthy volunteers drank 5 mL of water twice while sitting in a neutral posture. Thereafter, they drank the same amount of water twice in the head rotation and head tilting postures. The pressure and time during the deglutition process for each posture were measured with HRM. The data obtained for these two postures were compared with those obtained from the neutral posture. Results The maximum pressure, area, rise time, and duration in velopharynx (VP) and tongue base (TB) were not affected by changes in posture. In comparison, the maximum pressure and the pre-upper esophageal sphincter (UES) maximum pressure of the lower pharynx in the counter-catheter head rotation posture were lower than those in the neutral posture. The lower pharynx pressure in the catheter head tilting posture was higher than that in the counter-catheter head tilting. The changes in the VP peak and epiglottis, VP and TB peaks, and the VP onset and post-UES time intervals were significant in head tilting and head rotation toward the catheter postures, as compared with neutral posture. Conclusion The pharyngeal pressure and time parameter analysis using HRM determined the availability of head rotation as a compensatory technique for safe swallowing. Tilting the head smoothes the progress of food by increasing the pressure in the pharynx. PMID:26161349

  8. A qualitative systematic review of head-to-head randomized controlled trials of oral analgesics in neuropathic pain

    PubMed Central

    Watson, C Peter N; Gilron, Ian; Sawynok, Jana

    2010-01-01

    BACKGROUND: Neuropathic pain (NP) encompasses many difficult-to-treat disorders. There are few head-to-head, comparative, randomized controlled trials (RCTs) of drugs for NP in different analgesic categories, or of different drugs within a category, despite many placebo-controlled RCTs for individual agents. Well-designed head-to-head comparative trials are an effective way to determine the relative efficacy and safety of a new drug. OBJECTIVE: To perform a systematic review of head-to-head RCTs of oral analgesics in NP. METHODS: A systematic review of RCTs involving NP patients was performed, of which head-to-head comparative trials were selected. Reference lists from published systematic reviews were searched. These studies were rated according to the Jadad scale for quality. RESULTS AND CONCLUSIONS: Twenty-seven such trials were identified. Seventeen were comparisons of different analgesics, and 10 were of different drugs within an analgesic class. Important information was obtained about the relative efficacy and safety of drugs in different categories and within a category. Some significant differences between active treatments were reported. Trial inadequacies were identified. More and improved head-to-head RCTs are needed to inform clinical choices. PMID:20577657

  9. Head elevation and lateral head rotation effect on facemask ventilation efficiency: Randomized crossover trials.

    PubMed

    Matsunami, Sayuri; Komasawa, Nobuyasu; Konishi, Yuki; Minami, Toshiaki

    2017-11-01

    We performed two prospective randomized crossover trials to evaluate the effect of head elevation or lateral head rotation to facemask ventilation volume. In the first trial, facemask ventilation was performed with a 12-cm high pillow (HP) and 4-cm low pillow (LP) in 20 female patients who were scheduled to undergo general anesthesia. In the second trial, facemask ventilation was performed with and without lateral head rotation in another 20 female patients. Ventilation volume was measured in a pressure-controlled ventilation (PCV) manner at 10, 15, and 20 cmH 2 O inspiratory pressures. In the first trial evaluating head elevation effect, facemask ventilation volume was significantly higher with a HP than with a LP at 15 and 20 cmH 2 O inspiratory pressure (15 cmH 2 O: HP median 540 [ IQR 480-605] mL, LP 460 [400-520] mL, P=0.006, 20 cmH 2 O: HP 705 [650-800] mL, LP 560 [520-677] mL, P<0.001). In the second trial, lateral head rotation did not significantly increase facemask ventilation volume at all inspiratory pressure. Head elevation increased facemask ventilation volume in normal airway patients, while lateral head rotation did not. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Numerical assessment of the performance of a scalp-implantable antenna: effects of head anatomy and dielectric parameters.

    PubMed

    Kiourti, Asimina; Nikita, Konstantina S

    2013-04-01

    We numerically assess the effects of head properties (anatomy and dielectric parameters) on the performance of a scalp-implantable antenna for telemetry in the Medical Implant Communications Service band (402.0-405.0 MHz). Safety issues and performance (resonance, radiation) are analyzed for an experimentally validated implantable antenna (volume of 203.6 mm(3) ), considering five head models (3- and 5-layer spherical, 6-, 10-, and 13-tissue anatomical) and seven scenarios (variations ± 20% in the reference permittivity and conductivity values). Simulations are carried out at 403.5 MHz using the finite-difference time-domain method. Anatomy of the head model around the implantation site is found to mainly affect antenna performance, whereas overall tissue anatomy and dielectric parameters are less significant. Compared to the reference dielectric parameter scenario within the 3-layer spherical head, maximum variations of -19.9%, +3.7%, -55.1%, and -39.2% are computed in the maximum allowable net input power imposed by the IEEE Std C95.1-1999 and Std C95.1-2005 safety guidelines, return loss, and maximum far-field gain, respectively. Compliance with the recent IEEE Std C95.1-2005 is found to be almost insensitive to head properties, in contrast with IEEE Std C95.1-1999. Taking tissue property uncertainties into account is highlighted as crucial for implantable antenna design and performance assessment. Bioelectromagnetics 34:167-179, 2013. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.

  11. Anatomic fit of six different radial head plates: comparison of precontoured low-profile radial head plates.

    PubMed

    Burkhart, Klaus Josef; Nowak, Tobias E; Kim, Yoon-Joo; Rommens, Pol M; Müller, Lars P

    2011-04-01

    Bulky implants may lead to symptomatic soft tissue irritation after open reduction and internal fixation of radial head and neck fractures. The purpose of our study was to compare the anatomic fit of precontoured radial head plates. We stripped 22 embalmed human cadaveric radiuses of soft tissues. We investigated 6 radial head plates: (1) the Medartis radial head buttress plate (MBP), (2) the Medartis radial head rim plate (MRP), (3) the Synthes radial neck plate (SNP), (4) the Synthes radial head plate (SHP), (5) the Acumed radial head plate (AHP), and (6) the Wright radial head plate (WHP). Each plate was applied to each radial head at the place of best fit within the safe zone. We tested 4 parameters of anatomic fit: (1) plate-to-bone distance, (2) plate contact judged by 3 different observers, (3) pin-subchondral zone distance, and (4) plate-to-bone contact after adjustment of the plates. The MBP and MRP showed the lowest profile by objective measurements, the SNP and AHP had a moderate profile, and the SHP and WHP demonstrated the bulkiest profile. The subjective assessments also demonstrated the best fit for the MBP, a good fit for the SNP, a moderate fit for the MRP and AHP, and a poor fit for the SHP and WHP. The MBP, MRP, and AHP could always provide pin-subchondral zone contact, unlike the SHP, SNP, and WHP. After bending, significant improvement of plate-to-bone distance could only be seen for the MBP, MRP, and WHP. The ranking among plates remained the same except for the WHP, which showed a significantly lower plate-to-bone distance than the SHP. Currently available radial head implants are heterogeneous. The MBP and MRP showed the lowest profile and best anatomic fit. Owing to the complex radial head anatomy, to date there is no one radial head plate that perfectly fits all radial heads. Conformance of existing plates to the radial head and neck is not perfect. Careful plate selection and modification, when necessary, may minimize interference of this

  12. Socioeconomic status and quality of life in patients with locally advanced head and neck cancer.

    PubMed

    Tribius, S; Meyer, M S; Pflug, C; Hanken, H; Busch, C-J; Krüll, A; Petersen, C; Bergelt, C

    2018-05-07

    Socioeconomic aspects play an important role in health care. Patients with locally advanced head and neck cancer (LAHNC) experience detrimental effects on their quality of life (QoL). This prospective study examines QoL differences between patients with different socioeconomic status (SES) after intensity-modulated radiation therapy (IMRT). In all, 161 patients were questioned at the end of IMRT and at 12 and 24 months follow-up using the questionnaires of the European Organization for Research and Treatment of Cancer (EORTC) QLQ-30 and QLQ-HN35. Patients' QoL 2 years after IMRT was compared to a population reference sample and QoL of patients from lower, middle, and higher social class 2 years after IMRT was analyzed by ANCOVA using baseline QoL (end of radiation treatment) as a covariate. Patients with high SES report worse QoL at the end of IMRT in the domains global health status (-15.2; p = 0.005), role function (-23.8; p = 0.002), and social function (-19.4; p = 0.023) compared to patients with middle and low SES. QoL improved during the first 12 and 24 months. However, 2 years after IMRT, middle and low SES patients report lower QoL in the domains global health status, physical function, and role function, and report a higher general (fatigue, pain, dyspnea) and head and neck cancer-specific symptom burden (pain, swallowing, senses, speech, social eating, opening mouth, and felt ill) than patients with high SES. After IMRT for LAHNC, patients with high SES report worse QoL compared to patients with middle or low SES. There is a marked improvement within the first 24 months in many domains. However, the magnitude of improvement in patients with middle or low SES is significantly smaller compared to patients with high SES.

  13. Assessment of specific energy absorption rate (SAR) in the head from a TETRA handset.

    PubMed

    Dimbylow, Peter; Khalid, Mohammed; Mann, Simon

    2003-12-07

    Finite-difference time-domain (FDTD) calculations of the specific energy absorption rate (SAR) from a representative TETRA handset have been performed in an anatomically realistic model of the head. TETRA (Terrestrial Trunked Radio) is a modern digital private mobile radio system designed to meet the requirements of professional users, such as the police and fire brigade. The current frequency allocations in the UK are 380-385 MHz and 390-395 MHz for the public sector network. A comprehensive set of calculations of SAR in the head was performed for positions of the handset in front of the face and at both sides of the head. The representative TETRA handset considered. operating at 1 W in normal use, will show compliance with both the ICNIRP occupational and public exposure restrictions. The handset with a monopole antenna operating at 3 W in normal use will show compliance with both the ICNIRP occupational and public exposure restrictions. The handset with a helical antenna operating at 3 W in normal use will show compliance with the ICNIRP occupational exposure restriction but will be over the public exposure restriction by up to approximately 50% if kept in the position of maximum SAR for 6 min continuously.

  14. Mapping flexible protein domains at subnanometer resolution with the atomic force microscope.

    PubMed

    Müller, D J; Fotiadis, D; Engel, A

    1998-06-23

    The mapping of flexible protein domains with the atomic force microscope is reviewed. Examples discussed are the bacteriorhodopsin from Halobacterium salinarum, the head-tail-connector from phage phi29, and the hexagonally packed intermediate layer from Deinococcus radiodurans which all were recorded in physiological buffer solution. All three proteins undergo reversible structural changes that are reflected in standard deviation maps calculated from aligned topographs of individual protein complexes. Depending on the lateral resolution (up to 0.8 nm) flexible surface regions can ultimately be correlated with individual polypeptide loops. In addition, multivariate statistical classification revealed the major conformations of the protein surface.

  15. Second Primary Head and Neck Cancers After Non-Head and Neck Primary Cancers.

    PubMed

    Schlieve, Thomas; Heidel, R Eric; Carlson, Eric R

    2016-12-01

    The purpose of the present study was to determine the rate of second primary head and neck cancer development among patients with a primary cancer diagnosed outside the head and neck region, to present the clinical characteristics of this population, and to determine whether any variables are associated with survival. We designed a case series based on a sample of patients diagnosed with head and neck cancer who had previously been diagnosed with cancer located outside the head and neck region. The primary predictor variable was a diagnosis of cancer outside the head and neck region. The primary outcome variable was the diagnosis of a second cancer in the head and neck region. χ 2  Goodness-of-fit tests were used to test for differences between the observed and expected rates. A total of 19,406 cancers were diagnosed at the University of Tennessee Cancer Institute during the study period from July 1, 2004 to June 30, 2014. The rate of second primary head and neck cancer among patients with a non-head and neck primary cancer was 0.2%. These 40 cancers occurred among a total of 849 head and neck squamous cell carcinoma (HNSCC) cases (5%) diagnosed during the study period. The most common location for a second primary HNSCC was the gingiva (27.5%), followed by the oral tongue (17.5%). Significantly more gingival cancers were diagnosed than expected (P < .001) and significantly fewer tongue cancers than expected (P = .01). The most common primary cancer was prostate (27.5%), followed by breast (25%). The median survival was 28.5 months after the second primary diagnosis. A nonsignificant effect was found for age (P = .30), tobacco use (P = .12), gender (P = .60), TNM stage (P = .29), and treatment protocol (P = .96) on survival. The development of a second primary HNSCC in a population of patients with non-head and neck primary cancers is associated with decreased overall survival. The most common presentation of a second primary HNSCC in our study was in

  16. Vestibular Dysfunction after Subconcussive Head Impact

    PubMed Central

    Ma, Lei; Kawata, Keisuke; Tierney, Ryan; Jeka, John J.

    2017-01-01

    Abstract Current thinking views mild head impact (i.e., subconcussion) as an underrecognized phenomenon that has the ability to cause significant current and future detrimental neurological effects. Repeated mild impacts to the head, however, often display no observable behavioral deficits based on standard clinical tests, which may lack sensitivity. The current study investigates the effects of subconcussive impacts from soccer heading with innovative measures of vestibular function and walking stability in a pre- 0–2 h, post- 24 h post-heading repeated measures design. The heading group (n = 10) executed 10 headers with soccer balls projected at a velocity of 25 mph (11.2 m/sec) over 10 min. Subjects were evaluated 24 h before, immediately after, and 24 h after soccer heading with: the modified Balance Error Scoring System (mBESS); a walking stability task with visual feedback of trunk movement; and galvanic vestibular stimulation (GVS) while standing with eyes closed on foam. A control group (n = 10) followed the same protocol with no heading. The results showed significant decrease in trunk angle, leg angle gain, and center of mass gain relative to GVS for the heading group compared with controls. Medial-lateral trunk orientation displacement and velocity during treadmill walking increased immediately after mild head impact for the heading group compared with controls. Controls showed an improvement in mBESS scores over time, indicating a learning effect, which was not observed with the heading group. These results suggest that mild head impact leads to a transient dysfunction in vestibular processing, which deters walking stability during task performance. PMID:26885560

  17. Vestibular Dysfunction after Subconcussive Head Impact.

    PubMed

    Hwang, Sungjae; Ma, Lei; Kawata, Keisuke; Tierney, Ryan; Jeka, John J

    2017-01-01

    Current thinking views mild head impact (i.e., subconcussion) as an underrecognized phenomenon that has the ability to cause significant current and future detrimental neurological effects. Repeated mild impacts to the head, however, often display no observable behavioral deficits based on standard clinical tests, which may lack sensitivity. The current study investigates the effects of subconcussive impacts from soccer heading with innovative measures of vestibular function and walking stability in a pre- 0-2 h, post- 24 h post-heading repeated measures design. The heading group (n = 10) executed 10 headers with soccer balls projected at a velocity of 25 mph (11.2 m/sec) over 10 min. Subjects were evaluated 24 h before, immediately after, and 24 h after soccer heading with: the modified Balance Error Scoring System (mBESS); a walking stability task with visual feedback of trunk movement; and galvanic vestibular stimulation (GVS) while standing with eyes closed on foam. A control group (n = 10) followed the same protocol with no heading. The results showed significant decrease in trunk angle, leg angle gain, and center of mass gain relative to GVS for the heading group compared with controls. Medial-lateral trunk orientation displacement and velocity during treadmill walking increased immediately after mild head impact for the heading group compared with controls. Controls showed an improvement in mBESS scores over time, indicating a learning effect, which was not observed with the heading group. These results suggest that mild head impact leads to a transient dysfunction in vestibular processing, which deters walking stability during task performance.

  18. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly. 572.182 Section 572.182... Test Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the..., the head assembly shall meet performance requirements specified in paragraph (c) of this section. (b...

  19. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.182 Section 572.182... Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the head... assembly shall meet performance requirements specified in paragraph (c) of this section. (b) Test procedure...

  20. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly. 572.182 Section 572.182... Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the head... assembly shall meet performance requirements specified in paragraph (c) of this section. (b) Test procedure...

  1. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly. 572.182 Section 572.182... Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the head... assembly shall meet performance requirements specified in paragraph (c) of this section. (b) Test procedure...

  2. 49 CFR 572.182 - Head assembly.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly. 572.182 Section 572.182... Test Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the..., the head assembly shall meet performance requirements specified in paragraph (c) of this section. (b...

  3. Ship heading and velocity analysis by wake detection in SAR images

    NASA Astrophysics Data System (ADS)

    Graziano, Maria Daniela; D'Errico, Marco; Rufino, Giancarlo

    2016-11-01

    With the aim of ship-route estimation, a wake detection method is developed and applied to COSMO/SkyMed and TerraSAR-X Stripmap SAR images over the Gulf of Naples, Italy. In order to mitigate the intrinsic limitations of the threshold logic, the algorithm identifies the wake features according to the hydrodynamic theory. A post-detection validation phase is performed to classify the features as real wake structures by means of merit indexes defined in the intensity domain. After wake reconstruction, ship heading is evaluated on the basis of turbulent wake direction and ship velocity is estimated by both techniques of azimuth shift and Kelvin pattern wavelength. The method is tested over 34 ship wakes identified by visual inspection in both HH and VV images at different incidence angles. For all wakes, no missed detections are reported and at least the turbulent and one narrow-V wakes are correctly identified, with ship heading successfully estimated. Also, the azimuth shift method is applied to estimate velocity for the 10 ships having route with sufficient angular separation from the satellite ground track. In one case ship velocity is successfully estimated with both methods, showing agreement within 14%.

  4. Mortality prediction of head Abbreviated Injury Score and Glasgow Coma Scale: analysis of 7,764 head injuries.

    PubMed

    Demetriades, Demetrios; Kuncir, Eric; Murray, James; Velmahos, George C; Rhee, Peter; Chan, Linda

    2004-08-01

    We assessed the prognostic value and limitations of Glasgow Coma Scale (GCS) and head Abbreviated Injury Score (AIS) and correlated head AIS with GCS. We studied 7,764 patients with head injuries. Bivariate analysis was performed to examine the relationship of GCS, head AIS, age, gender, and mechanism of injury with mortality. Stepwise logistic regression analysis was used to identify the independent risk factors associated with mortality. The overall mortality in the group of head injury patients with no other major extracranial injuries and no hypotension on admission was 9.3%. Logistic regression analysis identified head AIS, GCS, age, and mechanism of injury as significant independent risk factors of death. The prognostic value of GCS and head AIS was significantly affected by the mechanism of injury and the age of the patient. Patients with similar GCS or head AIS but different mechanisms of injury or ages had significantly different outcomes. The adjusted odds ratio of death in penetrating trauma was 5.2 (3.9, 7.0), p < 0.0001, and in the age group > or = 55 years the adjusted odds ratio was 3.4 (2.6, 4.6), p < 0.0001. There was no correlation between head AIS and GCS (correlation coefficient -0.31). Mechanism of injury and age have a major effect in the predictive value of GCS and head AIS. There is no good correlation between GCS and head AIS.

  5. Head growth and neurocognitive outcomes.

    PubMed

    Wright, Charlotte M; Emond, Alan

    2015-06-01

    There is a lack of evidence on the value of head circumference (HC) as a screening measure. We aimed to describe the incidence of head centile shifting and the relationship between extremes of head size and later neurodevelopmental problems in the Avon Longitudinal Study of Parents and Children. HC was measured routinely at 2, 9, and 18 or 24 months and by researchers at ages 4, 8, 12, and 18 months. IQ according to the Wechsler Intelligence Scale for Children was measured in research clinics at age 8 for all. Neurocognitive disorders (NCDs) were identified from chart review. There were 10 851 children with ≥2 head measurements. At each age, 2% to 3% of children had scores that were < -2 or >2 SDs below or above the mean, but for most children this was only found at 1 age. More than 15% of children showed centile shifts, but less than one-third of these were sustained at subsequent measurements. Only 0.5% showed a sustained shift beyond the normal range. Children with consistently small heads were up to 7 times more likely to have an NCD, but 85% of children with small heads had no NCDs, and 93% of children with NCDs had head SD scores within the normal range. Centile shifts within the normal range occur commonly and seem mainly to reflect measurement error. This finding makes robust assessment of the head trajectory difficult and may result in many children being investigated unnecessarily. Extreme head size is neither specific nor sensitive for detecting NCDs, suggesting that routine measurement of HC is unhelpful. Copyright © 2015 by the American Academy of Pediatrics.

  6. AIDA: ab initio domain assembly for automated multi-domain protein structure prediction and domain–domain interaction prediction

    PubMed Central

    Xu, Dong; Jaroszewski, Lukasz; Li, Zhanwen; Godzik, Adam

    2015-01-01

    Motivation: Most proteins consist of multiple domains, independent structural and evolutionary units that are often reshuffled in genomic rearrangements to form new protein architectures. Template-based modeling methods can often detect homologous templates for individual domains, but templates that could be used to model the entire query protein are often not available. Results: We have developed a fast docking algorithm ab initio domain assembly (AIDA) for assembling multi-domain protein structures, guided by the ab initio folding potential. This approach can be extended to discontinuous domains (i.e. domains with ‘inserted’ domains). When tested on experimentally solved structures of multi-domain proteins, the relative domain positions were accurately found among top 5000 models in 86% of cases. AIDA server can use domain assignments provided by the user or predict them from the provided sequence. The latter approach is particularly useful for automated protein structure prediction servers. The blind test consisting of 95 CASP10 targets shows that domain boundaries could be successfully determined for 97% of targets. Availability and implementation: The AIDA package as well as the benchmark sets used here are available for download at http://ffas.burnham.org/AIDA/. Contact: adam@sanfordburnham.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25701568

  7. TES is a novel focal adhesion protein with a role in cell spreading.

    PubMed

    Coutts, Amanda S; MacKenzie, Elaine; Griffith, Elen; Black, Donald M

    2003-03-01

    Previously, we identified TES as a novel candidate tumour suppressor gene that mapped to human chromosome 7q31.1. In this report we demonstrate that the TES protein is localised at focal adhesions, actin stress fibres and areas of cell-cell contact. TES has three C-terminal LIM domains that appear to be important for focal adhesion targeting. Additionally, the N-terminal region is important for targeting TES to actin stress fibres. Yeast two-hybrid and biochemical analyses yielded interactions with several focal adhesion and/or cytoskeletal proteins including mena, zyxin and talin. The fact that TES localises to regions of cell adhesion suggests that it functions in events related to cell motility and adhesion. In support of this, we demonstrate that fibroblasts stably overexpressing TES have an increased ability to spread on fibronectin.

  8. The Habc Domain of the SNARE Vam3 Interacts with the HOPS Tethering Complex to Facilitate Vacuole Fusion*

    PubMed Central

    Lürick, Anna; Kuhlee, Anne; Bröcker, Cornelia; Kümmel, Daniel; Raunser, Stefan; Ungermann, Christian

    2015-01-01

    Membrane fusion at vacuoles requires a consecutive action of the HOPS tethering complex, which is recruited by the Rab GTPase Ypt7, and vacuolar SNAREs to drive membrane fusion. It is assumed that the Sec1/Munc18-like Vps33 within the HOPS complex is largely responsible for SNARE chaperoning. Here, we present direct evidence for HOPS binding to SNAREs and the Habc domain of the Vam3 SNARE protein, which may explain its function during fusion. We show that HOPS interacts strongly with the Vam3 Habc domain, assembled Q-SNAREs, and the R-SNARE Ykt6, but not the Q-SNARE Vti1 or the Vam3 SNARE domain. Electron microscopy combined with Nanogold labeling reveals that the binding sites for vacuolar SNAREs and the Habc domain are located in the large head of the HOPS complex, where Vps16 and Vps33 have been identified before. Competition experiments suggest that HOPS bound to the Habc domain can still interact with assembled Q-SNAREs, whereas Q-SNARE binding prevents recognition of the Habc domain. In agreement, membranes carrying Vam3ΔHabc fuse poorly unless an excess of HOPS is provided. These data suggest that the Habc domain of Vam3 facilitates the assembly of the HOPS/SNARE machinery at fusion sites and thus supports efficient membrane fusion. PMID:25564619

  9. Design of a frequency domain instrument for simultaneous optical tomography and magnetic resonance imaging of small animals

    NASA Astrophysics Data System (ADS)

    Masciotti, James M.; Rahim, Shaheed; Grover, Jarrett; Hielscher, Andreas H.

    2007-02-01

    We present a design for frequency domain instrument that allows for simultaneous gathering of magnetic resonance and diffuse optical tomographic imaging data. This small animal imaging system combines the high anatomical resolution of magnetic resonance imaging (MRI) with the high temporal resolution and physiological information provided by diffuse optical tomography (DOT). The DOT hardware comprises laser diodes and an intensified CCD camera, which are modulated up to 1 GHz by radio frequency (RF) signal generators. An optical imaging head is designed to fit inside the 4 cm inner diameter of a 9.4 T MRI system. Graded index fibers are used to transfer light between the optical hardware and the imaging head within the RF coil. Fiducial markers are integrated into the imaging head to allow the determination of the positions of the source and detector fibers on the MR images and to permit co-registration of MR and optical tomographic images. Detector fibers are arranged compactly and focused through a camera lens onto the photocathode of the intensified CCD camera.

  10. Inferring Domain-Domain Interactions from Protein-Protein Interactions with Formal Concept Analysis

    PubMed Central

    Khor, Susan

    2014-01-01

    Identifying reliable domain-domain interactions will increase our ability to predict novel protein-protein interactions, to unravel interactions in protein complexes, and thus gain more information about the function and behavior of genes. One of the challenges of identifying reliable domain-domain interactions is domain promiscuity. Promiscuous domains are domains that can occur in many domain architectures and are therefore found in many proteins. This becomes a problem for a method where the score of a domain-pair is the ratio between observed and expected frequencies because the protein-protein interaction network is sparse. As such, many protein-pairs will be non-interacting and domain-pairs with promiscuous domains will be penalized. This domain promiscuity challenge to the problem of inferring reliable domain-domain interactions from protein-protein interactions has been recognized, and a number of work-arounds have been proposed. This paper reports on an application of Formal Concept Analysis to this problem. It is found that the relationship between formal concepts provides a natural way for rare domains to elevate the rank of promiscuous domain-pairs and enrich highly ranked domain-pairs with reliable domain-domain interactions. This piggybacking of promiscuous domain-pairs onto less promiscuous domain-pairs is possible only with concept lattices whose attribute-labels are not reduced and is enhanced by the presence of proteins that comprise both promiscuous and rare domains. PMID:24586450

  11. Minnesota: Early Head Start Initiatiive

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Minnesota provides supplemental state funding to existing federal Head Start and Early Head Start (EHS) grantees to increase their capacity to serve additional infants, toddlers, and pregnant women. The initiative was started in 1997 when the state legislature earmarked $1 million of the general state Head Start supplemental funds for children…

  12. Spectral Domain Optical Coherence Tomography in Glaucoma: Qualitative and Quantitative Analysis of the Optic Nerve Head and Retinal Nerve Fiber Layer (An AOS Thesis)

    PubMed Central

    Chen, Teresa C.

    2009-01-01

    Purpose: To demonstrate that video-rate spectral domain optical coherence tomography (SDOCT) can qualitatively and quantitatively evaluate optic nerve head (ONH) and retinal nerve fiber layer (RNFL) glaucomatous structural changes. To correlate quantitative SDOCT parameters with disc photography and visual fields. Methods: SDOCT images from 4 glaucoma eyes (4 patients) with varying stages of open-angle glaucoma (ie, early, moderate, late) were qualitatively contrasted with 2 age-matched normal eyes (2 patients). Of 61 other consecutive patients recruited in an institutional setting, 53 eyes (33 patients) met inclusion/exclusion criteria for quantitative studies. Images were obtained using two experimental SDOCT systems, one utilizing a superluminescent diode and the other a titanium:sapphire laser source, with axial resolutions of about 6 μm and 3 μm, respectively. Results: Classic glaucomatous ONH and RNFL structural changes were seen in SDOCT images. An SDOCT reference plane 139 μm above the retinal pigment epithelium yielded cup-disc ratios that best correlated with masked physician disc photography cup-disc ratio assessments. The minimum distance band, a novel SDOCT neuroretinal rim parameter, showed good correlation with physician cup-disc ratio assessments, visual field mean deviation, and pattern standard deviation (P values range, .0003–.024). RNFL and retinal thickness maps correlated well with disc photography and visual field testing. Conclusions: To our knowledge, this thesis presents the first comprehensive qualitative and quantitative evaluation of SDOCT images of the ONH and RNFL in glaucoma. This pilot study provides basis for developing more automated quantitative SDOCT-specific glaucoma algorithms needed for future prospective multicenter national trials. PMID:20126502

  13. The influence of corneal astigmatism on retinal nerve fiber layer thickness and optic nerve head parameter measurements by spectral-domain optical coherence tomography.

    PubMed

    Liu, Lin; Zou, Jun; Huang, Hui; Yang, Jian-guo; Chen, Shao-rong

    2012-05-23

    To evaluate the influence of corneal astigmatism (CA) on retinal nerve fiber layer (RNFL) thickness and optic nerve head(ONH) parameters measured with spectral-domain optical coherence tomography (OCT) in high myopes patients before refractive surgery. Seventy eyes of 35 consecutive refractive surgery candidates were included in this study. The mean age of the subjects was 26.42 ± 6.95 years, the average CA was -1.17 diopters (D; SD 0.64; range -0.2 to-3.3D), All subjects in this study were WTR CA. 34 eyes were in the normal CA group with a mean CA was -0.67 ± 0.28D, 36 eyes were in the high CA group with an average CA of -1.65 ± 0.49D. All subjects underwent ophthalmic examination and imaging with the Cirrus HD OCT. No significant difference was noted in the average cup-to-disk ratio, vertical cup-to-disk ratio and cup volume (all P values > 0.05). Compared with the normal CA group, the high CA group had a larger disc area and rim area, thinner RNFL thickness in the temporal quadrant, and the superotemporal and inferotemporal peaks were farther to the temporal horizon (All P values < 0.05). There were no significant differences between the two groups in global average RNFL thickness, as well as superior, nasal and inferior quadrant RNFL thickness (all P values > 0.05). The degree of with-the-rule CA should be considered when interpreting ONH parameters and peripapillary RNFL thickness measured by the Cirrus HD OCT. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1148475676881895.

  14. Quality of Life in Swallowing Disorders after Nonsurgical Treatment for Head and Neck Cancer

    PubMed Central

    Silveira, Marta Halina; Dedivitis, Rogerio A.; Queija, Débora Santos; Nascimento, Paulo César

    2014-01-01

    Introduction Radiotherapy or chemoradiotherapy can result in severe swallowing disorders with potential risk for aspiration and can negatively impact the patient's quality of life (QOL). Objective To assess swallowing-related QOL in patients who underwent radiotherapy/chemoradiotherapy for head and neck cancer. Methods We interviewed 110 patients (85 men and 25 women) who had undergone exclusive radiotherapy (25.5%) or concomitant chemoradiotherapy (74.5%) from 6 to 12 months before the study. The Quality of Life in Swallowing Disorders (SWAL-QOL) questionnaire was employed to evaluate dysphagia-related QOL. Results The QOL was reduced in all domains for all patients. The scores were worse among men. There was a relationship between oral cavity as the primary cancer site and the fatigue domain and also between advanced cancer stage and the impact of food selection, communication, and social function domains. Chemoradiotherapy association, the presence of nasogastric tube and tracheotomy, and the persistence of alcoholism and smoking had also a negative effect on the QOL. Conclusions According to the SWAL-QOL questionnaire, the dysphagia-related impact on QOL was observed 6 to 12 months after the treatment ended. PMID:25992151

  15. The effect of long and short head biceps loading on glenohumeral joint rotational range of motion and humeral head position.

    PubMed

    McGarry, Michelle H; Nguyen, Michael L; Quigley, Ryan J; Hanypsiak, Bryan; Gupta, Ranjan; Lee, Thay Q

    2016-06-01

    To evaluate the effect of loading the long and short heads of the biceps on glenohumeral range of motion and humeral head position. Eight cadaveric shoulders were tested in 60° abduction in the scapula and coronal plane. Muscle loading was applied based on cross-sectional area ratios. The short and long head of the biceps were loaded individually followed by combined loading. Range of motion was measured with 2.2 Nm torque, and the humeral head apex position was measured using a MicroScribe. A paired t test with Bonferroni correction was used for statistics. Long head loading decreased internal rotation in both the scapular (17.9 %) and coronal planes (5.7 %) and external rotation in the scapular plane (2.6 %) (P < 0.04). With only short head loading, maximum internal rotation was significantly increased in the scapular and coronal plane. Long head and short head loading shifted the humeral head apex posteriorly in maximum internal rotation in both planes with the long head shift being significantly greater than the short head. Long head loading also shifted the humeral apex inferiorly in internal rotation and inferiorly posteriorly in neutral rotation in the scapular plane. With the long head unloaded, there was a significant superior shift with short head loading in both planes. Loading the long head of the biceps had a much greater effect on glenohumeral range of motion and humeral head shift than the short head of the biceps; however, in the absence of long head loading, with the short head loaded, maximum internal rotation increases and the humeral head shifts superiorly, which may contribute to impingement following tenodesis of the long head of the biceps. These small changes in rotational range of motion and humeral head position with biceps tenodesis may not lead to pathologic conditions in low-demand patients; however, in throwers, biceps tenodesis may lead to increased contact pressures in late-cocking and deceleration that will likely translate

  16. Brush head composition, wear profile, and cleaning efficacy: an assessment of three electric brush heads using in vitro methods.

    PubMed

    Kaiser, Eva; Meyners, Michael; Markgraf, Dirk; Stoerkel, Ulrich; von Koppenfels, Roxana; Adam, Ralf; Soukup, Martin; Wehrbein, Heinrich; Erbe, Christina

    2014-01-01

    The objective of this research was to evaluate a current store brand (SB) brush head for composition/physical characteristics, Wear Index (WI), and cleaning efficacy versus the previous SB brush head refill design (SB control) and the Oral-B Precision Clean brush head (positive control, PC). This research consisted of three parts: 1) Analytical analysis using Fourier Transform Infrared (FT-IR) spectrometry to evaluate the chemical composition of the current SB brush head bristles relative to the SB control. In addition, physical parameters such as bristle count and diameter were determined. 2) Wear Index (WI) investigation to determine the Wear Index scores of in vitro-aged brush heads at four weeks (one month) and 13 weeks (three months) by a trained investigator. To "age" the brush heads, a robot system was used as a new alternative in vitro method to simulate aging by consumer use. 3) Robot testing to determine the cleaning performance of in vitro-aged brush heads, comparing one month-aged current SB brush heads with the SB control (one and three months-aged) and the PC brush heads (three months-aged) in a standardized fashion. 1) FT-IR analysis revealed that the chemical composition of the current and control SB refill brush heads is identical. In terms of physical parameters, the current SB brush head has 12% more bristles and a slightly oval brush head compared to the round brush head of the SB control. 2) Wear Index analysis showed there was no difference in the one month-aged current SB brush head versus the one month-aged SB control (1.67 vs. 1.50, p = 0.65) or versus the three months-aged PC brush head (1.67 vs. 1.50, p = 0.65). The one month-aged current SB brush head demonstrated statistically significantly less wear than the three months-aged SB control (1.67 vs. 2.67, p = 0.01). 3) Analysis of cleaning efficacy shows that the one month-aged current SB brush head had improved cleaning performance over the one month-aged SB control brush head (p < 0

  17. Biomechanical investigation of head impacts in football

    PubMed Central

    Withnall, C; Shewchenko, N; Gittens, R; Dvorak, J

    2005-01-01

    Objectives: This study sought to measure the head accelerations induced from upper extremity to head and head to head impact during the game of football and relate this to the risk of mild traumatic brain injury using the Head Impact Power (HIP) index. Furthermore, measurement of upper neck forces and torques will indicate the potential for serious neck injury. More stringent rules or punitive sanctions may be warranted for intentional impact by the upper extremity or head during game play. Methods: Game video of 62 cases of head impact (38% caused by the upper extremity and 30% by the head of the opposing player) was provided by F-MARC. Video analysis revealed the typical impact configurations and representative impact speeds. Upper extremity impacts of elbow strike and lateral hand strike were re-enacted in the laboratory by five volunteer football players striking an instrumented Hybrid III pedestrian model crash test manikin. Head to head impacts were re-enacted using two instrumented test manikins. Results: Elbow to head impacts (1.7–4.6 m/s) and lateral hand strikes (5.2–9.3 m/s) resulted in low risk of concussion (<5%) and severe neck injury (<5%). Head to head impacts (1.5–3.0 m/s) resulted in high concussion risk (up to 67%) but low risk of severe neck injury (<5%). Conclusion: The laboratory simulations suggest little risk of concussion based on head accelerations and maximum HIP. There is no biomechanical justification for harsher penalties in this regard. However, deliberate use of the head to impact another player's head poses a high risk of concussion, and justifies a harsher position by regulatory bodies. In either case the risk of serious neck injury is very low. PMID:16046356

  18. Adjustment of saccade characteristics during head movements.

    NASA Technical Reports Server (NTRS)

    Morasso, P.; Bizzi, E.; Dichgans, J.

    1973-01-01

    Saccade characteristics have been studied during coordinated eye-head movements in monkeys. Amplitude, duration, and peak velocity of saccades with head turning were compared with saccades executed while the head was artificially restrained. The results indicate that the saccade characteristics are modulated as a function of head movement, hence the gaze movement (eye+head) exactly matches saccades with head fixed. Saccade modulation is achieved by way of negative vestibulo-ocular feedback. The neck proprioceptors, because of their longer latency, are effective only if the head starts moving prior to the onset of saccade. It is concluded that saccades make with head turning are not 'ballistic' movements because their trajectory is not entirely predetermined by a central command.

  19. Is Heading in Youth Soccer Dangerous Play?

    PubMed

    O'Kane, John W

    2016-01-01

    Soccer is among the most popular youth sports with over 3 million youth players registered in the U.S. Soccer is unique in that players intentionally use their head to strike the ball, leading to concerns that heading could cause acute or chronic brain injury, especially in the immature brains of children. Pub Med search without date restriction was conducted in November 2014 and August 2015 using the terms soccer and concussion, heading and concussion, and youth soccer and concussion. 310 articles were identified and reviewed for applicable content specifically relating to youth athletes, heading, and/or acute or chronic brain injury from soccer. Soccer is a low-risk sport for catastrophic head injury, but concussions are relatively common and heading often plays a role. At all levels of play, concussions are more likely to occur in the act of heading than with other facets of the game. While concussion from heading the ball without other contact to the head appears rare in adult players, some data suggests children are more susceptible to concussion from heading primarily in game situations. Contributing factors include biomechanical forces, less developed technique, and the immature brain's susceptibility to injury. There is no evidence that heading in youth soccer causes any permanent brain injury and there is limited evidence that heading in youth soccer can cause concussion. A reasonable approach based on U.S. Youth Soccer recommendations is to teach heading after age 10 in controlled settings, and heading in games should be delayed until skill acquisition and physical maturity allow the youth player to head correctly with confidence.

  20. Head injury - first aid

    MedlinePlus

    ... medlineplus.gov/ency/article/000028.htm Head injury - first aid To use the sharing features on this page, ... a concussion can range from mild to severe. First Aid Learning to recognize a serious head injury and ...

  1. The domain organization of the bacterial intermediate filament-like protein crescentin is important for assembly and function

    PubMed Central

    Cabeen, Matthew T; Herrmann, Harald; Jacobs-Wagner, Christine

    2011-01-01

    Crescentin is a bacterial filament-forming protein that exhibits domain organization features found in metazoan intermediate filament (IF) proteins. Structure-function studies of eukaryotic IFs have been hindered by a lack of simple genetic systems and easily quantifiable phenotypes. Here we exploit the characteristic localization of the crescentin structure along the inner curvature of Caulobacter crescentus cells and the loss of cell curvature associated with impaired crescentin function to analyze the importance of the domain organization of crescentin. By combining biochemistry and ultrastructural analysis in vitro with cellular localization and functional studies, we show that crescentin requires its distinctive domain organization, and furthermore that different structural elements have distinct structural and functional contributions. The head domain can be functionally subdivided into two subdomains; the first (amino-terminal) is required for function but not assembly, while the second is necessary for structure assembly. The rod domain is similarly required for structure assembly, and the linker L1 appears important to prevent runaway assembly into nonfunctional aggregates. The data also suggest that the stutter and the tail domain have critical functional roles in stabilizing crescentin structures against disassembly by monovalent cations in the cytoplasm. This study suggests that the IF-like behavior of crescentin is a consequence of its domain organization, implying that the IF protein layout is an adaptable cytoskeletal motif, much like the actin and tubulin folds, that is broadly exploited for various functions throughout life from bacteria to humans. © 2011 Wiley-Liss, Inc. PMID:21360832

  2. Cybersickness Onset With Reflexive Head Movements During Land and Shipboard Head-Mounted Display Flight Simulation

    DTIC Science & Technology

    2010-09-09

    provoked a predictable OKCR coronal head tilt (p < 0.001) whenever aircraft angle of bank (AOB) increased (Fig. 2). With 90º of simulated AOB, land... head pitch were –3.3 ± 3.8 to 6.8 ± 5.9 on land, and –4.0º ± 5.6 to 7.6º ± 9.7 at sea (Fig. 3). 7 Combined Coronal OKCR ( Head Tilt ) Data for...Land OKCR Figure 2: Coronal OKCR ( head tilt ) vs. angle of bank, during both land based and shipboard HMD/VR flight simulation. Combined

  3. Predicting domain-domain interaction based on domain profiles with feature selection and support vector machines

    PubMed Central

    2010-01-01

    Background Protein-protein interaction (PPI) plays essential roles in cellular functions. The cost, time and other limitations associated with the current experimental methods have motivated the development of computational methods for predicting PPIs. As protein interactions generally occur via domains instead of the whole molecules, predicting domain-domain interaction (DDI) is an important step toward PPI prediction. Computational methods developed so far have utilized information from various sources at different levels, from primary sequences, to molecular structures, to evolutionary profiles. Results In this paper, we propose a computational method to predict DDI using support vector machines (SVMs), based on domains represented as interaction profile hidden Markov models (ipHMM) where interacting residues in domains are explicitly modeled according to the three dimensional structural information available at the Protein Data Bank (PDB). Features about the domains are extracted first as the Fisher scores derived from the ipHMM and then selected using singular value decomposition (SVD). Domain pairs are represented by concatenating their selected feature vectors, and classified by a support vector machine trained on these feature vectors. The method is tested by leave-one-out cross validation experiments with a set of interacting protein pairs adopted from the 3DID database. The prediction accuracy has shown significant improvement as compared to InterPreTS (Interaction Prediction through Tertiary Structure), an existing method for PPI prediction that also uses the sequences and complexes of known 3D structure. Conclusions We show that domain-domain interaction prediction can be significantly enhanced by exploiting information inherent in the domain profiles via feature selection based on Fisher scores, singular value decomposition and supervised learning based on support vector machines. Datasets and source code are freely available on the web at http

  4. Shivering heat production and core cooling during head-in and head-out immersion in 17 degrees C water.

    PubMed

    Pretorius, Thea; Cahill, Farrell; Kocay, Sheila; Giesbrecht, Gordon G

    2008-05-01

    Many cold-water scenarios cause the head to be partially or fully immersed (e.g., ship wreck survival, scuba diving, cold-water adventure swim racing, cold-water drowning, etc.). However, the specific effects of head cold exposure are minimally understood. This study isolated the effect of whole-head submersion in cold water on surface heat loss and body core cooling when the protective shivering mechanism was intact. Eight healthy men were studied in 17 degrees C water under four conditions: the body was either insulated or exposed, with the head either out of the water or completely submersed under the water within each insulated/exposed subcondition. Submersion of the head (7% of the body surface area) in the body-exposed condition increased total heat loss by 11% (P < 0.05). After 45 min, head-submersion increased core cooling by 343% in the body-insulated subcondition (head-out: 0.13 +/- 0.2 degree C, head-in: 0.47 +/- 0.3 degree C; P < 0.05) and by 56% in the body-exposed subcondition (head-out: 0.40 +/- 0.3 degree C and head-in: 0.73 +/- 0.6 degree C; P < 0.05). In both body-exposed and body-insulated subconditions, head submersion increased the rate of core cooling disproportionally more than the relative increase in total heat loss. This exaggerated core-cooling effect is consistent with a head cooling induced reduction of the thermal core, which could be stimulated by cooling of thermosensitive and/or trigeminal receptors in the scalp, neck, and face. These cooling effects of head submersion are not prevented by shivering heat production.

  5. Effects of head-down bed rest on complex heart rate variability: Response to LBNP testing

    NASA Technical Reports Server (NTRS)

    Goldberger, Ary L.; Mietus, Joseph E.; Rigney, David R.; Wood, Margie L.; Fortney, Suzanne M.

    1994-01-01

    Head-down bed rest is used to model physiological changes during spaceflight. We postulated that bed rest would decrease the degree of complex physiological heart rate variability. We analyzed continuous heart rate data from digitized Holter recordings in eight healthy female volunteers (age 28-34 yr) who underwent a 13-day 6 deg head-down bed rest study with serial lower body negative pressure (LBNP) trials. Heart rate variability was measured on a 4-min data sets using conventional time and frequency domain measures as well as with a new measure of signal 'complexity' (approximate entropy). Data were obtained pre-bed rest (control), during bed rest (day 4 and day 9 or 11), and 2 days post-bed rest (recovery). Tolerance to LBNP was significantly reduced on both bed rest days vs. pre-bed rest. Heart rate variability was assessed at peak LBNP. Heart rate approximate entropy was significantly decreased at day 4 and day 9 or 11, returning toward normal during recovery. Heart rate standard deviation and the ratio of high- to low-power frequency did not change significantly. We conclude that short-term bed rest is associated with a decrease in the complex variability of heart rate during LBNP testing in healthy young adult women. Measurement of heart rate complexity, using a method derived from nonlinear dynamics ('chaos theory'), may provide a sensitive marker of this loss of physiological variability, complementing conventional time and frequency domain statistical measures.

  6. Maryland Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Since 2000, Maryland has provided state supplemental funds to Head Start and Early Head Start (EHS) programs to improve access. Local EHS programs may use funds, through child care partnerships, to extend the EHS day or year. Maryland's approach to building on EHS includes: (1) Increase the capacity of existing Head Start and EHS programs to…

  7. Pigeons (C. livia) Follow Their Head during Turning Flight: Head Stabilization Underlies the Visual Control of Flight.

    PubMed

    Ros, Ivo G; Biewener, Andrew A

    2017-01-01

    Similar flight control principles operate across insect and vertebrate fliers. These principles indicate that robust solutions have evolved to meet complex behavioral challenges. Following from studies of visual and cervical feedback control of flight in insects, we investigate the role of head stabilization in providing feedback cues for controlling turning flight in pigeons. Based on previous observations that the eyes of pigeons remain at relatively fixed orientations within the head during flight, we test potential sensory control inputs derived from head and body movements during 90° aerial turns. We observe that periods of angular head stabilization alternate with rapid head repositioning movements (head saccades), and confirm that control of head motion is decoupled from aerodynamic and inertial forces acting on the bird's continuously rotating body during turning flapping flight. Visual cues inferred from head saccades correlate with changes in flight trajectory; whereas the magnitude of neck bending predicts angular changes in body position. The control of head motion to stabilize a pigeon's gaze may therefore facilitate extraction of important motion cues, in addition to offering mechanisms for controlling body and wing movements. Strong similarities between the sensory flight control of birds and insects may also inspire novel designs of robust controllers for human-engineered autonomous aerial vehicles.

  8. Pigeons (C. livia) Follow Their Head during Turning Flight: Head Stabilization Underlies the Visual Control of Flight

    PubMed Central

    Ros, Ivo G.; Biewener, Andrew A.

    2017-01-01

    Similar flight control principles operate across insect and vertebrate fliers. These principles indicate that robust solutions have evolved to meet complex behavioral challenges. Following from studies of visual and cervical feedback control of flight in insects, we investigate the role of head stabilization in providing feedback cues for controlling turning flight in pigeons. Based on previous observations that the eyes of pigeons remain at relatively fixed orientations within the head during flight, we test potential sensory control inputs derived from head and body movements during 90° aerial turns. We observe that periods of angular head stabilization alternate with rapid head repositioning movements (head saccades), and confirm that control of head motion is decoupled from aerodynamic and inertial forces acting on the bird's continuously rotating body during turning flapping flight. Visual cues inferred from head saccades correlate with changes in flight trajectory; whereas the magnitude of neck bending predicts angular changes in body position. The control of head motion to stabilize a pigeon's gaze may therefore facilitate extraction of important motion cues, in addition to offering mechanisms for controlling body and wing movements. Strong similarities between the sensory flight control of birds and insects may also inspire novel designs of robust controllers for human-engineered autonomous aerial vehicles. PMID:29249929

  9. Quality of life after parotid-sparing IMRT for head-and-neck cancer: a prospective longitudinal study.

    PubMed

    Lin, Alexander; Kim, Hyungjin M; Terrell, Jeffrey E; Dawson, Laura A; Ship, Jonathan A; Eisbruch, Avraham

    2003-09-01

    Parotid-sparing intensity-modulated radiotherapy (IMRT) for head-and-neck cancer reduces xerostomia compared with standard RT. To assess potential improvements in broader aspects of quality of life (QOL), we initiated a study of patient-reported QOL and its predictors after IMRT. This was a prospective longitudinal study of head-and-neck cancer patients receiving multisegmental static IMRT. Patients were given a validated xerostomia questionnaire (XQ), and a validated head-and-neck cancer-related QOL questionnaire consisting of four multi-item domains: Eating, Communication, Pain, and Emotion. The Eating domain contains one question (total of six) asking directly about xerostomia. In both questionnaires, higher scores denote worse symptoms or QOL. The questionnaires and measurements of salivary output from the major glands were completed before RT started (pre-RT) and at 3, 6, and 12 months after RT. The association between the QOL scores and patient-, tumor-, and therapy-related factors was assessed using the random effects model. Thirty-six patients participating in the study completed the questionnaires through 12 months. The XQ scores worsened significantly at 3 months compared with the pre-RT scores, but later they improved gradually through 12 months (p = 0.003), in parallel with an increase in the salivary output from the spared salivary glands. The QOL summary scores were stable between the baseline (pre-RT) and 3 months after RT scores. Patients receiving postoperative RT (whose pre-RT questionnaires were taken a few weeks after surgery) tended to have improved scores after RT, reflecting the subsidence of acute postoperative sequelae, compared with a tendency toward worsened scores in patients receiving definitive RT. After 3 months, statistically significant improvement was noted in the summary QOL scores for all patients, through 12 months after RT (p = 0.01). The salivary flow rates, tumor doses, mean oral cavity dose, age, gender, sites or stages of

  10. Head and Neck Cancer

    MedlinePlus

    Head and neck cancer includes cancers of the mouth, nose, sinuses, salivary glands, throat, and lymph nodes in the ... swallowing A change or hoarseness in the voice Head and neck cancers are twice as common in men. Using ...

  11. Stereotactic Body Radiotherapy for Head and Neck Tumors

    ClinicalTrials.gov

    2016-04-18

    Squamous Cell Carcinoma of the Head and Neck; Nasopharyngeal Carcinoma; Salivary Gland Cancer; Head and Neck Sarcoma; Paraganglioma of Head and Neck; Chordoma of Head and Neck; Chondrosarcoma of Head and Neck; Angiofibroma of Head and Neck

  12. Head tilt during driving.

    PubMed

    Zikovitz, D C; Harris, L R

    1999-05-01

    In order to distinguish between the use of visual and gravito-inertial force reference frames, the head tilt of drivers and passengers were measured as they went around corners at various speeds. The visual curvature of the corners were thus dissociated from the magnitude of the centripetal forces (0.30-0.77 g). Drivers' head tilts were highly correlated with the visually-available estimate of the curvature of the road (r2=0.86) but not with the centripetal force (r2<0.1). Passengers' head tilts were inversely correlated with the lateral forces (r2=0.3-0.7) and seem to reflect a passive sway. The strong correlation of the tilt of drivers' heads with a visual aspect of the road ahead, supports the use of a predominantly visual reference frame for the driving task.

  13. Head Lice - Multiple Languages

    MedlinePlus

    ... Are Here: Home → Multiple Languages → All Health Topics → Head Lice URL of this page: https://medlineplus.gov/languages/ ... V W XYZ List of All Topics All Head Lice - Multiple Languages To use the sharing features on ...

  14. Quality Disparities in Child Care for At-Risk Children: Comparing Head Start and Non-Head Start Settings

    PubMed Central

    Hillemeier, Marianne M.; Morgan, Paul L.; Farkas, George; Maczuga, Steven A.

    2012-01-01

    The study objectives are to describe child care type and quality experienced by developmentally at-risk children, examine quality differences between Head Start and non-Head Start settings, and identify factors associated with receiving higher-quality child care. Data are analyzed from the Early Childhood Longitudinal Survey, Birth Cohort, a prospective study of a nationally representative sample of US children born in 2001. The sample consisted of 7,500 children who were assessed at 48 months of age. The outcome of interest is child care quality, measured by the Early Childhood Environmental Rating Scale (center care) and the Family Day Care Rating Scale (family day care). Results of descriptive and multivariate regression analyses are presented. Less than one-third of poor children were in Head Start. Child care quality was higher in Head Start centers than other centers, particularly among poor children (4.75 vs. 4.28, p < 0.001), Hispanics (4.90 vs. 4.45, p < 0.001), and whites (4.89 vs. 4.51, p < 0.001). African Americans experienced the lowest quality care in both Head Start and non-Head Start centers. Quality disadvantage was associated with Head Start family care settings, especially for low birthweight children (2.04 in Head Start vs. 3.58 in non-Head Start, p < 0.001). Lower family day care quality was associated with less maternal education and African American and Hispanic ethnicity. Center-based Head Start provides higher quality child care for at-risk children, and expansion of these services will likely facilitate school readiness in these populations. Quality disadvantages in Head Start family day care settings are worrisome and warrant investigation. PMID:22392601

  15. Head Circumference and Height in Autism

    PubMed Central

    Lainhart, Janet E.; Bigler, Erin D.; Bocian, Maureen; Coon, Hilary; Dinh, Elena; Dawson, Geraldine; Deutsch, Curtis K.; Dunn, Michelle; Estes, Annette; Tager-Flusberg, Helen; Folstein, Susan; Hepburn, Susan; Hyman, Susan; McMahon, William; Minshew, Nancy; Munson, Jeff; Osann, Kathy; Ozonoff, Sally; Rodier, Patricia; Rogers, Sally; Sigman, Marian; Spence, M. Anne; Stodgell, Christopher J.; Volkmar, Fred

    2016-01-01

    Data from 10 sites of the NICHD/NIDCD Collaborative Programs of Excellence in Autism were combined to study the distribution of head circumference and relationship to demographic and clinical variables. Three hundred thirty-eight probands with autism-spectrum disorder (ASD) including 208 probands with autism were studied along with 147 parents, 149 siblings, and typically developing controls. ASDs were diagnosed, and head circumference and clinical variables measured in a standardized manner across all sites. All subjects with autism met ADI-R, ADOS-G, DSM-IV, and ICD-10 criteria. The results show the distribution of standardized head circumference in autism is normal in shape, and the mean, variance, and rate of macrocephaly but not microcephaly are increased. Head circumference tends to be large relative to height in autism. No site, gender, age, SES, verbal, or non-verbal IQ effects were present in the autism sample. In addition to autism itself, standardized height and average parental head circumference were the most important factors predicting head circumference in individuals with autism. Mean standardized head circumference and rates of macrocephaly were similar in probands with autism and their parents. Increased head circumference was associated with a higher (more severe) ADI-R social algorithm score. Macrocephaly is associated with delayed onset of language. Although mean head circumference and rates of macrocephaly are increased in autism, a high degree of variability is present, underscoring the complex clinical heterogeneity of the disorder. The wide distribution of head circumference in autism has major implications for genetic, neuroimaging, and other neurobiological research. PMID:17022081

  16. Dynamics of chiral domain wall under the spin-orbit torques in heavy metal/ferromagnet bilayers with in-plane anisotropy

    NASA Astrophysics Data System (ADS)

    Yan, Han; He, Peng-Bin; Cai, Meng-Qiu; Li, Zai-Dong

    2017-11-01

    The dynamics of domain wall driven by the spin-orbit torques is theoretically studied in the heavy metal/ferromagnet bilayer with Dzyaloshinskii-Moriya interaction (DMI) and in-plane magnetic anisotropy. Based on the Walker profile, we infer that DMI has a selectivity for the chirality of head-to-head (tail-to-tail) static wall. By analyzing the dynamic equations obtained from the collective coordinates methods, we find that there exists a switching or a hysteresis of the polarity of wall in the low-current regime. In the presence of DMI, the wall can keep sustained propagation which velocity saturates for high current and is proportional to the strength of DMI. Furthermore, the DMI makes the adjacent walls possess the same chirality and move in the same direction.

  17. Inadequate reporting of concomitant drug treatment in cardiovascular interventional head-to-head trials.

    PubMed

    Mahfoud, Felix; Böhm, Michael; Baumhäkel, Magnus

    2012-04-01

    Optimal revascularization strategy is still under debate in patients with coronary artery disease, particularly due to the results of the Synergy Between Percutaneous Coronary Intervention With TAXUS and Cardiac Surgery (SYNTAX) trial. Although medical prevention has been clearly shown to be beneficial in coronary artery disease, it has been suggested that patients were significantly undertreated with evidence-based medications for cardiovascular protection. The purpose of the study was to evaluate concomitant medical treatment in cardiovascular interventional head-to-head trials comparing coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). A systematic search of the literature regarding documentation and reports of medical treatment in cardiovascular interventional head-to-head trials with more than 500 patients comparing CABG and PCI was performed. Systematic research of the literature identified 2106 articles of potential interest. After review and selection, only 3 trials reported on medical treatment. Baseline medication was reported in the RITA (Randomized Intervention Treatment of Angina), CABRI (Coronary Angioplasty versus Bypass Revascularisation Investigation), and SYNTAX trials, and follow-up data were provided by the CABRI and SYNTAX 3-year trials only. Poor reporting of medical treatment at discharge might reflect an underestimation of secondary prevention in patients undergoing cardiac surgery or interventional procedures in head-to-head interventional trials. Thus, discussion of optimal revascularization procedure has to remain open, even in terms of concomitant medical treatment of patients. © 2012 Wiley Periodicals, Inc.

  18. Promoting Children's Social-Emotional Skills in Preschool Can Enhance Academic and Behavioral Functioning in Kindergarten: Findings from Head Start REDI

    PubMed Central

    Nix, Robert L.; Bierman, Karen L.; Domitrovich, Celene E.; Gill, Sukhdeep

    2013-01-01

    This study examined processes of change associated with the positive preschool and kindergarten outcomes of children who received the Head Start REDI intervention, compared to “usual practice” Head Start. In a large-scale randomized-controlled trial (N = 356 children, 42% African American or Latino, all from low-income families), this study tests the logic model that improving preschool social-emotional skills (e.g., emotion understanding, social problem solving, and positive social behavior) as well as language/emergent literacy skills will promote cross-domain academic and behavioral adjustment after children transition into kindergarten. Validating this logic model, the present study finds that intervention effects on three important kindergarten outcomes (e.g., reading achievement, learning engagement, and positive social behavior) were mediated by preschool gains in the proximal social-emotional and language/emergent literacy skills targeted by the REDI intervention. Importantly, preschool gains in social-emotional skills made unique contributions to kindergarten outcomes in reading achievement and learning engagement, even after accounting for the concurrent preschool gains in vocabulary and emergent literacy skills. These findings highlight the importance of fostering at-risk children's social-emotional skills during preschool as a means of promoting school readiness. The REDI (Research-Based, Developmentally-Informed) enrichment intervention was designed to complement and strengthen the impact of existing Head Start programs in the dual domains of language/emergent literacy skills and social-emotional competencies. REDI was one of several projects funded by the Interagency School Readiness Consortium, a partnership of four federal agencies (the National Institute of Child Health and Human Development, the Administration for Children and Families, the Assistant Secretary for Planning and Evaluation in the Department of Health and Human Services, and the

  19. Exploiting domain information for Word Sense Disambiguation of medical documents

    PubMed Central

    Agirre, Eneko; Soroa, Aitor

    2011-01-01

    Objective Current techniques for knowledge-based Word Sense Disambiguation (WSD) of ambiguous biomedical terms rely on relations in the Unified Medical Language System Metathesaurus but do not take into account the domain of the target documents. The authors' goal is to improve these methods by using information about the topic of the document in which the ambiguous term appears. Design The authors proposed and implemented several methods to extract lists of key terms associated with Medical Subject Heading terms. These key terms are used to represent the document topic in a knowledge-based WSD system. They are applied both alone and in combination with local context. Measurements A standard measure of accuracy was calculated over the set of target words in the widely used National Library of Medicine WSD dataset. Results and discussion The authors report a significant improvement when combining those key terms with local context, showing that domain information improves the results of a WSD system based on the Unified Medical Language System Metathesaurus alone. The best results were obtained using key terms obtained by relevance feedback and weighted by inverse document frequency. PMID:21900701

  20. [Duodenum-preserving total pancreatic head resection and pancreatic head resection with segmental duodenostomy].

    PubMed

    Takada, Tadahiro; Yasuda, Hideki; Nagashima, Ikuo; Amano, Hodaka; Yoshiada, Masahiro; Toyota, Naoyuki

    2003-06-01

    A duodenum-preserving pancreatic head resection (DPPHR) was first reported by Beger et al. in 1980. However, its application has been limited to chronic pancreatitis because of it is a subtotal pancreatic head resection. In 1990, we reported duodenum-preserving total pancreatic head resection (DPTPHR) in 26 cases. This opened the way for total pancreatic head resection, expanding the application of this approach to tumorigenic morbidities such as intraductal papillary mucinous tumor (IMPT), other benign tumors, and small pancreatic cancers. On the other hand, Nakao et al. reported pancreatic head resection with segmental duodenectomy (PHRSD) as an alternative pylorus-preserving pancreatoduodenectomy technique in 24 cases. Hirata et al. also reported this technique as a new pylorus-preserving pancreatoduodenostomy with increased vessel preservation. When performing DPTPHR, the surgeon should ensure adequate duodenal blood supply. Avoidance of duodenal ischemia is very important in this operation, and thus it is necessary to maintain blood flow in the posterior pancreatoduodenal artery and to preserve the mesoduodenal vessels. Postoperative pancreatic functional tests reveal that DPTPHR is superior to PPPD, including PHSRD, because the entire duodenum and duodenal integrity is very important for postoperative pancreatic function.

  1. Validation and calibration of HeadCount, a self-report measure for quantifying heading exposure in soccer players.

    PubMed

    Catenaccio, E; Caccese, J; Wakschlag, N; Fleysher, R; Kim, N; Kim, M; Buckley, T A; Stewart, W F; Lipton, R B; Kaminski, T; Lipton, M L

    2016-01-01

    The long-term effects of repetitive head impacts due to heading are an area of increasing concern, and exposure must be accurately measured; however, the validity of self-report of cumulative soccer heading is not known. In order to validate HeadCount, a 2-week recall questionnaire, the number of player-reported headers was compared to the number of headers observed by trained raters for a men's and a women's collegiate soccer teams during an entire season of competitive play using Spearman's correlations and intraclass correlation coefficients (ICCs), and calibrated using a generalized estimating equation. The average Spearman's rho was 0.85 for men and 0.79 for women. The average ICC was 0.75 in men and 0.38 in women. The calibration analysis demonstrated that men tend to report heading accurately while women tend to overestimate. HeadCount is a valid instrument for tracking heading behaviour, but may have to be calibrated in women.

  2. Merkel cell carcinoma of the head and neck: poorer prognosis than non-head and neck sites.

    PubMed

    Morand, G B; Madana, J; Da Silva, S D; Hier, M P; Mlynarek, A M; Black, M J

    2016-04-01

    Merkel cell carcinoma is a rare, aggressive neurocutaneous malignancy. This study investigated whether patients with Merkel cell carcinoma in the head and neck had poorer outcomes than patients with Merkel cell carcinoma located elsewhere. A retrospective study was performed of patients with Merkel cell carcinoma treated at the Jewish General Hospital in Montréal, Canada, from 1993 to 2013. Associations between clinicopathological characteristics and disease-free and disease-specific survival rates were examined according to the Kaplan-Meier method. Twenty-seven patients were identified. Although basic clinicopathological characteristics and treatments were similar between head and neck and non-head and neck Merkel cell carcinoma groups, disease-free and disease-specific survival rates were significantly lower in the head and neck Merkel cell carcinoma group (log-rank test; p = 0.043 and p = 0.001, respectively). Mortality was mainly due to distant metastasis. Patients with head and neck Merkel cell carcinoma had poorer survival rates than patients with non-head and neck Merkel cell carcinoma in our study. The tendency to obtain close margins, a less predictable metastatic pattern, and/or intrinsic tumour factors related to the head and neck may explain this discrepancy.

  3. Head Rotation Movement Times.

    PubMed

    Hoffmann, Errol R; Chan, Alan H S; Heung, P T

    2017-09-01

    The aim of this study was to measure head rotation movement times in a Fitts' paradigm and to investigate the transition region from ballistic movements to visually controlled movements as the task index of difficulty (ID) increases. For head rotation, there are gaps in the knowledge of the effects of movement amplitude and task difficulty around the critical transition region from ballistic movements to visually controlled movements. Under the conditions of 11 ID values (from 1.0 to 6.0) and five movement amplitudes (20° to 60°), participants performed a head rotation task, and movement times were measured. Both the movement amplitude and task difficulty have effects on movement times at low IDs, but movement times are dependent only on ID at higher ID values. Movement times of participants are higher than for arm/hand movements, for both ballistic and visually controlled movements. The information-processing rate of head rotational movements, at high ID values, is about half that of arm movements. As an input mode, head rotations are not as efficient as the arm system either in ability to use rapid ballistic movements or in the rate at which information may be processed. The data of this study add to those in the review of Hoffmann for the critical IDs of different body motions. The data also allow design for the best arrangement of display that is under the design constraints of limited display area and difficulty of head-controlled movements in a data-inputting task.

  4. Effects of dwell time of excitation waveform on meniscus movements for a tubular piezoelectric print-head: experiments and model

    NASA Astrophysics Data System (ADS)

    Chang, Jiaqing; Liu, Yaxin; Huang, Bo

    2017-07-01

    In inkjet applications, it is normal to search for an optimal drive waveform when dispensing a fresh fluid or adjusting a newly fabricated print-head. To test trial waveforms with different dwell times, a camera and a strobe light were used to image the protruding or retracting liquid tongues without ejecting any droplets. An edge detection method was used to calculate the lengths of the liquid tongues to draw the meniscus movement curves. The meniscus movement is determined by the time-domain response of the acoustic pressure at the nozzle of the print-head. Starting at the inverse piezoelectric effect, a mathematical model which considers the liquid viscosity in acoustic propagation is constructed to study the acoustic pressure response at the nozzle of the print-head. The liquid viscosity retards the propagation speed and dampens the harmonic amplitude. The pressure response, which is the combined effect of the acoustic pressures generated during the rising time and the falling time and after their propagations and reflections, explains the meniscus movements well. Finally, the optimal dwell time for droplet ejections is discussed.

  5. Same but not alike: Structure, flexibility and energetics of domains in multi-domain proteins are influenced by the presence of other domains

    PubMed Central

    Vishwanath, Sneha

    2018-01-01

    The majority of the proteins encoded in the genomes of eukaryotes contain more than one domain. Reasons for high prevalence of multi-domain proteins in various organisms have been attributed to higher stability and functional and folding advantages over single-domain proteins. Despite these advantages, many proteins are composed of only one domain while their homologous domains are part of multi-domain proteins. In the study presented here, differences in the properties of protein domains in single-domain and multi-domain systems and their influence on functions are discussed. We studied 20 pairs of identical protein domains, which were crystallized in two forms (a) tethered to other proteins domains and (b) tethered to fewer protein domains than (a) or not tethered to any protein domain. Results suggest that tethering of domains in multi-domain proteins influences the structural, dynamic and energetic properties of the constituent protein domains. 50% of the protein domain pairs show significant structural deviations while 90% of the protein domain pairs show differences in dynamics and 12% of the residues show differences in the energetics. To gain further insights on the influence of tethering on the function of the domains, 4 pairs of homologous protein domains, where one of them is a full-length single-domain protein and the other protein domain is a part of a multi-domain protein, were studied. Analyses showed that identical and structurally equivalent functional residues show differential dynamics in homologous protein domains; though comparable dynamics between in-silico generated chimera protein and multi-domain proteins were observed. From these observations, the differences observed in the functions of homologous proteins could be attributed to the presence of tethered domain. Overall, we conclude that tethered domains in multi-domain proteins not only provide stability or folding advantages but also influence pathways resulting in differences in

  6. Same but not alike: Structure, flexibility and energetics of domains in multi-domain proteins are influenced by the presence of other domains.

    PubMed

    Vishwanath, Sneha; de Brevern, Alexandre G; Srinivasan, Narayanaswamy

    2018-02-01

    The majority of the proteins encoded in the genomes of eukaryotes contain more than one domain. Reasons for high prevalence of multi-domain proteins in various organisms have been attributed to higher stability and functional and folding advantages over single-domain proteins. Despite these advantages, many proteins are composed of only one domain while their homologous domains are part of multi-domain proteins. In the study presented here, differences in the properties of protein domains in single-domain and multi-domain systems and their influence on functions are discussed. We studied 20 pairs of identical protein domains, which were crystallized in two forms (a) tethered to other proteins domains and (b) tethered to fewer protein domains than (a) or not tethered to any protein domain. Results suggest that tethering of domains in multi-domain proteins influences the structural, dynamic and energetic properties of the constituent protein domains. 50% of the protein domain pairs show significant structural deviations while 90% of the protein domain pairs show differences in dynamics and 12% of the residues show differences in the energetics. To gain further insights on the influence of tethering on the function of the domains, 4 pairs of homologous protein domains, where one of them is a full-length single-domain protein and the other protein domain is a part of a multi-domain protein, were studied. Analyses showed that identical and structurally equivalent functional residues show differential dynamics in homologous protein domains; though comparable dynamics between in-silico generated chimera protein and multi-domain proteins were observed. From these observations, the differences observed in the functions of homologous proteins could be attributed to the presence of tethered domain. Overall, we conclude that tethered domains in multi-domain proteins not only provide stability or folding advantages but also influence pathways resulting in differences in

  7. Maneuvering impact boring head

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zollinger, W.T.; Reutzel, E.W.

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure. 8 figs.

  8. Maneuvering impact boring head

    DOEpatents

    Zollinger, W.T.; Reutzel, E.W.

    1998-08-18

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure. 8 figs.

  9. Maneuvering impact boring head

    DOEpatents

    Zollinger, W. Thor; Reutzel, Edward W.

    1998-01-01

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

  10. The PYRIN domain: A member of the death domain-fold superfamily

    PubMed Central

    Fairbrother, Wayne J.; Gordon, Nathaniel C.; Humke, Eric W.; O'Rourke, Karen M.; Starovasnik, Melissa A.; Yin, Jian-Ping; Dixit, Vishva M.

    2001-01-01

    PYRIN domains were identified recently as putative protein–protein interaction domains at the N-termini of several proteins thought to function in apoptotic and inflammatory signaling pathways. The ∼95 residue PYRIN domains have no statistically significant sequence homology to proteins with known three-dimensional structure. Using secondary structure prediction and potential-based fold recognition methods, however, the PYRIN domain is predicted to be a member of the six-helix bundle death domain-fold superfamily that includes death domains (DDs), death effector domains (DEDs), and caspase recruitment domains (CARDs). Members of the death domain-fold superfamily are well established mediators of protein–protein interactions found in many proteins involved in apoptosis and inflammation, indicating further that the PYRIN domains serve a similar function. An homology model of the PYRIN domain of CARD7/DEFCAP/NAC/NALP1, a member of the Apaf-1/Ced-4 family of proteins, was constructed using the three-dimensional structures of the FADD and p75 neurotrophin receptor DDs, and of the Apaf-1 and caspase-9 CARDs, as templates. Validation of the model using a variety of computational techniques indicates that the fold prediction is consistent with the sequence. Comparison of a circular dichroism spectrum of the PYRIN domain of CARD7/DEFCAP/NAC/NALP1 with spectra of several proteins known to adopt the death domain-fold provides experimental support for the structure prediction. PMID:11514682

  11. Ultrahigh-Speed Optical Coherence Tomography for Three-Dimensional and En Face Imaging of the Retina and Optic Nerve Head

    PubMed Central

    Srinivasan, Vivek J.; Adler, Desmond C.; Chen, Yueli; Gorczynska, Iwona; Huber, Robert; Duker, Jay S.; Schuman, Joel S.; Fujimoto, James G.

    2009-01-01

    Purpose To demonstrate ultrahigh-speed optical coherence tomography (OCT) imaging of the retina and optic nerve head at 249,000 axial scans per second and a wavelength of 1060 nm. To investigate methods for visualization of the retina, choroid, and optic nerve using high-density sampling enabled by improved imaging speed. Methods A swept-source OCT retinal imaging system operating at a speed of 249,000 axial scans per second was developed. Imaging of the retina, choroid, and optic nerve were performed. Display methods such as speckle reduction, slicing along arbitrary planes, en face visualization of reflectance from specific retinal layers, and image compounding were investigated. Results High-definition and three-dimensional (3D) imaging of the normal retina and optic nerve head were performed. Increased light penetration at 1060 nm enabled improved visualization of the choroid, lamina cribrosa, and sclera. OCT fundus images and 3D visualizations were generated with higher pixel density and less motion artifacts than standard spectral/Fourier domain OCT. En face images enabled visualization of the porous structure of the lamina cribrosa, nerve fiber layer, choroid, photoreceptors, RPE, and capillaries of the inner retina. Conclusions Ultrahigh-speed OCT imaging of the retina and optic nerve head at 249,000 axial scans per second is possible. The improvement of ∼5 to 10× in imaging speed over commercial spectral/Fourier domain OCT technology enables higher density raster scan protocols and improved performance of en face visualization methods. The combination of the longer wavelength and ultrahigh imaging speed enables excellent visualization of the choroid, sclera, and lamina cribrosa. PMID:18658089

  12. Neural correlates of conflict between gestures and words: A domain-specific role for a temporal-parietal complex.

    PubMed

    Noah, J Adam; Dravida, Swethasri; Zhang, Xian; Yahil, Shaul; Hirsch, Joy

    2017-01-01

    The interpretation of social cues is a fundamental function of human social behavior, and resolution of inconsistencies between spoken and gestural cues plays an important role in successful interactions. To gain insight into these underlying neural processes, we compared neural responses in a traditional color/word conflict task and to a gesture/word conflict task to test hypotheses of domain-general and domain-specific conflict resolution. In the gesture task, recorded spoken words ("yes" and "no") were presented simultaneously with video recordings of actors performing one of the following affirmative or negative gestures: thumbs up, thumbs down, head nodding (up and down), or head shaking (side-to-side), thereby generating congruent and incongruent communication stimuli between gesture and words. Participants identified the communicative intent of the gestures as either positive or negative. In the color task, participants were presented the words "red" and "green" in either red or green font and were asked to identify the color of the letters. We observed a classic "Stroop" behavioral interference effect, with participants showing increased response time for incongruent trials relative to congruent ones for both the gesture and color tasks. Hemodynamic signals acquired using functional near-infrared spectroscopy (fNIRS) were increased in the right dorsolateral prefrontal cortex (DLPFC) for incongruent trials relative to congruent trials for both tasks consistent with a common, domain-general mechanism for detecting conflict. However, activity in the left DLPFC and frontal eye fields and the right temporal-parietal junction (TPJ), superior temporal gyrus (STG), supramarginal gyrus (SMG), and primary and auditory association cortices was greater for the gesture task than the color task. Thus, in addition to domain-general conflict processing mechanisms, as suggested by common engagement of right DLPFC, socially specialized neural modules localized to the left

  13. Head-up and head-down displays integration in automobiles

    NASA Astrophysics Data System (ADS)

    Betancur, J. Alejandro; Osorio-Gómez, Gilberto; Agudelo, J. David

    2014-06-01

    In automotive industry, the dashboard has been ergonomically developed in order to keep the driver focused on the horizon while driving, but the possibility to access external electronic devices constraints the driver to turn away his face, generating dangerous situations in spite of the short periods of time. Therefore, this work explores the integration of Head-Up Displays and Head-Down Displays in automobiles, proposing configurations that give to drivers the facility to driving focused. In this way, some of the main ergonomic comments about those configurations are proposed; and also, some technical comments regarding the implemented arrangements are given.

  14. Mutation of domain III and domain VI in L gene conserved domain of Nipah virus

    NASA Astrophysics Data System (ADS)

    Jalani, Siti Aishah; Ibrahim, Nazlina

    2016-11-01

    Nipah virus (NiV) is the etiologic agent responsible for the respiratory illness and causes fatal encephalitis in human. NiV L protein subunit is thought to be responsible for the majority of enzymatic activities involved in viral transcription and replication. The L protein which is the viral RNA dependent RNA polymerase has high sequence homology among negative sense RNA viruses. In negative stranded RNA viruses, based on sequence alignment six conserved domain (domain I-IV) have been determined. Each domain is separated on variable regions that suggest the structure to consist concatenated functional domain. To directly address the roles of domains III and VI, site-directed mutations were constructed by the substitution of bases at sequences 2497, 2500, 5528 and 5532. Each mutated L gene can be used in future studies to test the ability for expression on in vitro translation.

  15. HEAD MOVEMENT DURING WALKING IN THE CAT

    PubMed Central

    ZUBAIR, HUMZA N.; BELOOZEROVA, IRINA N.; SUN, HAI; MARLINSKI, VLADIMIR

    2016-01-01

    Knowledge of how the head moves during locomotion is essential for understanding how locomotion is controlled by sensory systems of the head. We have analyzed head movements of the cat walking along a straight flat pathway in the darkness and light. We found that cats' head left-right translations, and roll and yaw rotations oscillated once per stride, while fore-aft and vertical translations, and pitch rotations oscillated twice. The head reached its highest vertical positions during second half of each forelimb swing, following maxima of the shoulder/trunk by 20–90°. Nose-up rotation followed head upward translation by another 40–90° delay. The peak-to-peak amplitude of vertical translation was ~1.5 cm and amplitude of pitch rotation was ~3°. Amplitudes of lateral translation and roll rotation were ~1 cm and 1.5–3°, respectively. Overall, cats' heads were neutral in roll and 10–30° nose-down, maintaining horizontal semicircular canals and utriculi within 10° of the earth horizontal. The head longitudinal velocity was 0.5–1 m/s, maximal upward and downward linear velocities were ~0.05 and ~0.1 m/s, respectively, and maximal lateral velocity was ~0.05 m/s. Maximal velocities of head pitch rotation were 20–50 °/s. During walking in light, cats stood 0.3–0.5 cm taller and held their head 0.5–2 cm higher than in darkness. Forward acceleration was 25–100% higher and peak-to-peak amplitude of head pitch oscillations was ~20 °/s larger. We concluded that, during walking, the head of the cat is held actively. Reflexes appear to play only a partial role in determining head movement, and vision might further diminish their role. PMID:27339731

  16. Head movement during walking in the cat.

    PubMed

    Zubair, Humza N; Beloozerova, Irina N; Sun, Hai; Marlinski, Vladimir

    2016-09-22

    Knowledge of how the head moves during locomotion is essential for understanding how locomotion is controlled by sensory systems of the head. We have analyzed head movements of the cat walking along a straight flat pathway in the darkness and light. We found that cats' head left-right translations, and roll and yaw rotations oscillated once per stride, while fore-aft and vertical translations, and pitch rotations oscillated twice. The head reached its highest vertical positions during second half of each forelimb swing, following maxima of the shoulder/trunk by 20-90°. Nose-up rotation followed head upward translation by another 40-90° delay. The peak-to-peak amplitude of vertical translation was ∼1.5cm and amplitude of pitch rotation was ∼3°. Amplitudes of lateral translation and roll rotation were ∼1cm and 1.5-3°, respectively. Overall, cats' heads were neutral in roll and 10-30° nose-down, maintaining horizontal semicircular canals and utriculi within 10° of the earth horizontal. The head longitudinal velocity was 0.5-1m/s, maximal upward and downward linear velocities were ∼0.05 and ∼0.1m/s, respectively, and maximal lateral velocity was ∼0.05m/s. Maximal velocities of head pitch rotation were 20-50°/s. During walking in light, cats stood 0.3-0.5cm taller and held their head 0.5-2cm higher than in darkness. Forward acceleration was 25-100% higher and peak-to-peak amplitude of head pitch oscillations was ∼20°/s larger. We concluded that, during walking, the head of the cat is held actively. Reflexes appear to play only a partial role in determining head movement, and vision might further diminish their role. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. The influence of corneal astigmatism on retinal nerve fiber layer thickness and optic nerve head parameter measurements by spectral-domain optical coherence tomography

    PubMed Central

    2012-01-01

    Background To evaluate the influence of corneal astigmatism (CA) on retinal nerve fiber layer (RNFL) thickness and optic nerve head(ONH) parameters measured with spectral-domain optical coherence tomography (OCT) in high myopes patients before refractive surgery. Methods Seventy eyes of 35 consecutive refractive surgery candidates were included in this study. The mean age of the subjects was 26.42 ± 6.95 years, the average CA was −1.17 diopters (D; SD 0.64; range −0.2 to-3.3D), All subjects in this study were WTR CA. 34 eyes were in the normal CA group with a mean CA was −0.67 ± 0.28D, 36 eyes were in the high CA group with an average CA of −1.65 ± 0.49D. All subjects underwent ophthalmic examination and imaging with the Cirrus HD OCT. Results No significant difference was noted in the average cup-to-disk ratio, vertical cup-to-disk ratio and cup volume (all P values > 0.05). Compared with the normal CA group, the high CA group had a larger disc area and rim area, thinner RNFL thickness in the temporal quadrant, and the superotemporal and inferotemporal peaks were farther to the temporal horizon (All P values < 0.05). There were no significant differences between the two groups in global average RNFL thickness, as well as superior, nasal and inferior quadrant RNFL thickness (all P values > 0.05). Conclusions The degree of with-the-rule CA should be considered when interpreting ONH parameters and peripapillary RNFL thickness measured by the Cirrus HD OCT. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1148475676881895 PMID:22621341

  18. International Federation of Head Neck Oncology Society 5(th) World Congress/American Head Neck Society 2014 update.

    PubMed

    Sharma, Shilpi; Chaukar, Devendra A

    2014-07-01

    Head neck cancer is an important health problem with high morbidity and mortality. Early detection and adequate treatment improve prognosis significantly. Thus creating awareness among clinicians is an important step toward control of head neck cancer and reducing its overall burden. We here provide an update on the International Federation of Head Neck Oncology Society/American Head Neck Society 2014 held between July 26, 2014 and July 30, 2014 in New York.

  19. The perception of heading during eye movements

    NASA Technical Reports Server (NTRS)

    Royden, Constance S.; Banks, Martin S.; Crowell, James A.

    1992-01-01

    Warren and Hannon (1988, 1990), while studying the perception of heading during eye movements, concluded that people do not require extraretinal information to judge heading with eye/head movements present. Here, heading judgments are examined at higher, more typical eye movement velocities than the extremely slow tracking eye movements used by Warren and Hannon. It is found that people require extraretinal information about eye position to perceive heading accurately under many viewing conditions.

  20. Visual perception of axes of head rotation

    PubMed Central

    Arnoldussen, D. M.; Goossens, J.; van den Berg, A. V.

    2013-01-01

    Registration of ego-motion is important to accurately navigate through space. Movements of the head and eye relative to space are registered through the vestibular system and optical flow, respectively. Here, we address three questions concerning the visual registration of self-rotation. (1) Eye-in-head movements provide a link between the motion signals received by sensors in the moving eye and sensors in the moving head. How are these signals combined into an ego-rotation percept? We combined optic flow of simulated forward and rotational motion of the eye with different levels of eye-in-head rotation for a stationary head. We dissociated simulated gaze rotation and head rotation by different levels of eye-in-head pursuit. We found that perceived rotation matches simulated head- not gaze-rotation. This rejects a model for perceived self-rotation that relies on the rotation of the gaze line. Rather, eye-in-head signals serve to transform the optic flow's rotation information, that specifies rotation of the scene relative to the eye, into a rotation relative to the head. This suggests that transformed visual self-rotation signals may combine with vestibular signals. (2) Do transformed visual self-rotation signals reflect the arrangement of the semi-circular canals (SCC)? Previously, we found sub-regions within MST and V6+ that respond to the speed of the simulated head rotation. Here, we re-analyzed those Blood oxygenated level-dependent (BOLD) signals for the presence of a spatial dissociation related to the axes of visually simulated head rotation, such as have been found in sub-cortical regions of various animals. Contrary, we found a rather uniform BOLD response to simulated rotation along the three SCC axes. (3) We investigated if subject's sensitivity to the direction of the head rotation axis shows SCC axes specifcity. We found that sensitivity to head rotation is rather uniformly distributed, suggesting that in human cortex, visuo-vestibular integration is

  1. Mechanisms of head injuries in elite football

    PubMed Central

    Andersen, T; Arnason, A; Engebretsen, L; Bahr, R

    2004-01-01

    Objectives: The aim of this study was to describe, using video analysis, the mechanisms of head injuries and of incidents with a high risk of head injury in elite football. Methods: Videotapes and injury information were collected prospectively for 313 of the 409 matches played in the Norwegian (2000 season) and Icelandic (1999 and 2000 season) professional leagues. Video recordings of incidents where a player appeared to be hit in the head and the match was consequently interrupted by the referee were analysed and cross referenced with reports of acute time loss injuries from the team medical staff. Results: The video analysis revealed 192 incidents (18.8 per 1000 player hours). Of the 297 acute injuries reported, 17 (6%) were head injuries, which corresponds to an incidence of 1.7 per 1000 player hours (concussion incidence 0.5 per 1000 player hours). The most common playing action was a heading duel with 112 cases (58%). The body part that hit the injured player's head was the elbow/arm/hand in 79 cases (41%), the head in 62 cases (32%), and the foot in 25 cases (13%). In 67 of the elbow/arm/hand impacts, the upper arm of the player causing the incident was at or above shoulder level, and the arm use was considered to be active in 61 incidents (77%) and intentional in 16 incidents (20%). Conclusions: This study suggests that video analysis provides detailed information about the mechanisms for head injuries in football. The most frequent injury mechanism was elbow to head contact, followed by head to head contact in heading duels. In the majority of the elbow to head incidents, the elbow was used actively at or above shoulder level, and stricter rule enforcement or even changes in the laws of the game concerning elbow use should perhaps be considered, in order to reduce the risk of head injury. PMID:15562161

  2. The Randomized-Controlled Trial of Head Start REDI: Sustained Effects on Developmental Trajectories of Social-Emotional Functioning

    PubMed Central

    Nix, Robert L.; Bierman, Karen L.; Heinrichs, Brenda S.; Gest, Scott D.; Welsh, Janet A.; Domitrovich, Celene E.

    2015-01-01

    Objective This study assessed the sustained effects of Head Start REDI (Research-based, Developmentally-Informed), a randomized-controlled preschool preventive intervention, on children’s developmental trajectories of social-emotional functioning into elementary school. Method Twenty-five Head Start centers with 44 classrooms were randomly assigned to deliver Head Start REDI, which featured an integrated language-emergent literacy and social-emotional skills curriculum and enhanced support for positive teaching practices, or Head Start “as usual.” The 356 4-year old children (54% girls; 25% African American; 17% Latino; 70% living in poverty) in those centers and classrooms were followed for five years (from preschool through third grade; 91% retention rate). Each year teachers rated multiple domains of social-emotional functioning. Person-oriented latent class growth models were used to identify the different developmental trajectories of social-emotional functioning that children followed. Results Tests of proportions revealed that children who had been in the Head Start REDI intervention were statistically significantly more likely than children in the control condition to exhibit the most optimal developmental trajectories of social competence, aggressive-oppositional behavior, learning engagement, attention problems, student-teacher closeness, and peer rejection (odds ratios = 1.60 – 1.93). Conclusions These findings suggest that enriching Head Start with evidence-based curriculum components and teaching practices can have long-lasting benefits for children’s social-emotional functioning. These findings elucidate how high-quality preschool experiences promote core competencies that are critical to the school success of children living in poverty. Public health significance statement When children participated in the enriched preschool program Head Start REDI, they were more likely to follow optimal developmental trajectories of social

  3. Combustor with non-circular head end

    DOEpatents

    Kim, Won -Wook; McMahan, Kevin Weston

    2015-09-29

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a head end with a non-circular configuration, a number of fuel nozzles positioned about the head end, and a transition piece extending downstream of the head end.

  4. Domain wall nanoelectronics

    NASA Astrophysics Data System (ADS)

    Catalan, G.; Seidel, J.; Ramesh, R.; Scott, J. F.

    2012-01-01

    Domains in ferroelectrics were considered to be well understood by the middle of the last century: They were generally rectilinear, and their walls were Ising-like. Their simplicity stood in stark contrast to the more complex Bloch walls or Néel walls in magnets. Only within the past decade and with the introduction of atomic-resolution studies via transmission electron microscopy, electron holography, and atomic force microscopy with polarization sensitivity has their real complexity been revealed. Additional phenomena appear in recent studies, especially of magnetoelectric materials, where functional properties inside domain walls are being directly measured. In this paper these studies are reviewed, focusing attention on ferroelectrics and multiferroics but making comparisons where possible with magnetic domains and domain walls. An important part of this review will concern device applications, with the spotlight on a new paradigm of ferroic devices where the domain walls, rather than the domains, are the active element. Here magnetic wall microelectronics is already in full swing, owing largely to the work of Cowburn and of Parkin and their colleagues. These devices exploit the high domain wall mobilities in magnets and their resulting high velocities, which can be supersonic, as shown by Kreines’ and co-workers 30 years ago. By comparison, nanoelectronic devices employing ferroelectric domain walls often have slower domain wall speeds, but may exploit their smaller size as well as their different functional properties. These include domain wall conductivity (metallic or even superconducting in bulk insulating or semiconducting oxides) and the fact that domain walls can be ferromagnetic while the surrounding domains are not.

  5. Head Start Policy Manual 70.2: The Parents = El Papel de los Padres en Head Start.

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

    Noting that the gains made by children must be understood and supported by the family and community, Head Start gives parents and other family members many opportunities to develop an appreciation of the young child's needs and how to meet those needs. Successful parental involvement enters into every aspect of Head Start; therefore, Head Start…

  6. Training Head Start Coordinators for Workplace Preparedness. NCCU Head Start Monograph, October 1995.

    ERIC Educational Resources Information Center

    North Carolina Central Univ., Durham.

    This monograph summarizes results from academic capstone activities of graduate students and faculty advisors regarding issues consistent with Head Start national priorities and practice needs. The following theses are summarized: (1) "Multicultural Education in Head Start Programs in North Carolina" (S.K. Gant); (2) "The Impact of…

  7. Prevalence of seizures in cats after head trauma.

    PubMed

    Grohmann, Kristina S; Schmidt, Martin J; Moritz, Andreas; Kramer, Martin

    2012-12-01

    To determine the prevalence of seizures in cats after head trauma. Retrospective cross-sectional study. 52 cats with head trauma. Information was obtained from medical records of cats with head trauma and via telephone interviews of owners at least 2 years after cats had head trauma. Severity of head trauma in cats was classified with the modified Glasgow coma scale (mGCS), and the association between scores and development of seizures was determined. 9 cats had moderate head trauma (mGCS score, 9 to 14), and 43 cats had mild head trauma (mGCS score, 15 to 18). None of the cats developed seizures during the follow-up period (≥ 2 years after head injury). The calculated 95% confidence interval for prevalence of seizures in cats after head injury was 0% to 5.6%. There was no significant relationship between severity of head trauma and the risk of seizures in cats. Results indicated the probability that cats with mild to moderate head trauma would develop posttraumatic seizures was low. However, clinicians should monitor cats with a history of head trauma for development of secondary epilepsy.

  8. Boxing-related head injuries.

    PubMed

    Jayarao, Mayur; Chin, Lawrence S; Cantu, Robert C

    2010-10-01

    Fatalities in boxing are most often due to traumatic brain injury that occurs in the ring. In the past 30 years, significant improvements in ringside and medical equipment, safety, and regulations have resulted in a dramatic reduction in the fatality rate. Nonetheless, the rate of boxing-related head injuries, particularly concussions, remains unknown, due in large part to its variability in clinical presentation. Furthermore, the significance of repeat concussions sustained when boxing is just now being understood. In this article, we identify the clinical manifestations, pathophysiology, and management of boxing-related head injuries, and discuss preventive strategies to reduce head injuries sustained by boxers.

  9. Prototype flaking head smooths surfaces left by headrig or edger chipping heads

    Treesearch

    P. Koch

    1976-01-01

    Flaking heads arranged to follow headrig and edger chipper heads would smooth machined surfaces and produce high-value flakes of near optimum dimensions for structural flakeboard. In the proposed concept, eight knives are closely grouped in a 45-degree helix on a cutterhead tipped at 45-degree angle to the direction of workpiece feed. Each knife is set out in cutting...

  10. Tackler’s head position relative to the ball carrier is highly correlated with head and neck injuries in rugby

    PubMed Central

    Hasegawa, Yoshinori; Shiota, Yuki; Ota, Chihiro; Yoneda, Takeshi; Tahara, Shigeyuki; Maki, Nobukazu; Matsuura, Takahiro; Sekiguchi, Masahiro; Itoigawa, Yoshiaki; Tateishi, Tomohiko; Kaneko, Kazuo

    2018-01-01

    Objectives To characterise the tackler’s head position during one-on-one tackling in rugby and to determine the incidence of head, neck and shoulder injuries through analysis of game videos, injury records and a questionnaire completed by the tacklers themselves. Methods We randomly selected 28 game videos featuring two university teams in competitions held in 2015 and 2016. Tackles were categorised according to tackler’s head position. The ‘pre-contact phase’ was defined; its duration and the number of steps taken by the ball carrier prior to a tackle were evaluated. Results In total, 3970 tackles, including 317 (8.0%) with the tackler’s head incorrectly positioned (ie, in front of the ball carrier) were examined. Thirty-two head, neck or shoulder injuries occurred for an injury incidence of 0.8% (32/3970). The incidence of injury in tackles with incorrect head positioning was 69.4/1000 tackles; the injury incidence with correct head positioning (ie, behind or to one side of the ball carrier) was 2.7/1000 tackles. Concussions, neck injuries, ‘stingers’ and nasal fractures occurred significantly more often during tackles with incorrect head positioning than during tackles with correct head positioning. Significantly fewer steps were taken before tackles with incorrect head positioning that resulted in injury than before tackles that did not result in injury. Conclusion Tackling with incorrect head position relative to the ball carrier resulted in a significantly higher incidence of concussions, neck injuries, stingers and nasal fractures than tackling with correct head position. Tackles with shorter duration and distance before contact resulted in more injuries. PMID:29162618

  11. Perspectives about family meals from single-headed and dual-headed households: a qualitative analysis.

    PubMed

    Berge, Jerica M; Hoppmann, Caroline; Hanson, Carrie; Neumark-Sztainer, Dianne

    2013-12-01

    Cross-sectional and longitudinal research has shown that family meals are protective for adolescent healthful eating behaviors. However, little is known about what parents think of these findings and whether parents from single- vs dual-headed households have differing perspectives about the findings. In addition, parents' perspectives regarding barriers to applying the findings on family meals in their own homes and suggestions for more widespread adoption of the findings are unknown. The current study aimed to identify single- and dual-headed household parents' perspectives regarding the research findings on family meals, barriers to applying the findings in their own homes, and suggestions for helping families have more family meals. The current qualitative study included 59 parents who participated in substudy of two linked multilevel studies-EAT 2010 (Eating and Activity in Teens) and Families and Eating and Activity in Teens (F-EAT). Parents (91.5% female) were racially/ethnically and socioeconomically diverse. Data were analyzed using a grounded theory approach. Results from the current study suggest that parents from both single- and dual-headed households have similar perspectives regarding why family meals are protective for healthful eating habits for adolescents (eg, provides structure/routine, opportunities for communication, connection), but provide similar and different reasons for barriers to family meals (eg, single-headed=cost vs dual-headed=lack of creativity) and ideas and suggestions for how to increase the frequency of family meals (eg, single-headed=give fewer options vs dual-headed=include children in the meal preparation). Findings can help inform public health intervention researchers and providers who work with adolescents and their families to understand how to approach discussions regarding reasons for having family meals, barriers to carrying out family meals, and ways to increase family meals depending on family structure. Copyright

  12. Perspectives about Family Meals from Single-Headed and Dual-Headed Households: A Qualitative Analysis

    PubMed Central

    Berge, Jerica M.; Hoppmann, Caroline; Hanson, Carrie; Neumark-Sztainer, Dianne

    2013-01-01

    Cross-sectional and longitudinal research has shown that family meals are protective for adolescent healthful eating behaviors. However, little is known about what parents think of these findings and whether parents from single- versus dual-headed households have differing perspectives about the findings. Additionally, parents’ perspectives regarding barriers to applying the findings on family meals in their own homes and suggestions for more wide-spread adoption of the findings are unknown. The current study aimed to identify single- and dual-headed household parents’ perspectives regarding the research findings on family meals, barriers to applying the findings in their own homes and suggestions for helping families have more family meals. The current qualitative study included 59 parents who participated in sub-study of two linked multi-level studies—EAT 2010 (Eating and Activity in Teens) and Families and Eating and Activity in Teens (F-EAT). Parents (91.5% female) were racially/ethnically and socio-economically diverse. Data were analyzed using a grounded theory approach. Results from the current study suggest that parents from both single- and dual-headed households have similar perspectives regarding why family meals are protective for healthful eating habits for adolescents (e.g., provides structure/routine, opportunities for communication, connection), but provide similar and different reasons for barriers to family meals (e.g., single-headed=cost vs. dual-headed=lack of creativity) and ideas and suggestions for how to increase the frequency of family meals (e.g., single-headed=give fewer options vs. dual-headed=include children in the meal preparation). Findings may help inform public health intervention researchers and providers who work with adolescents and their families to understand how to approach discussions regarding reasons for having family meals, barriers to carrying out family meals and ways to increase family meals depending on family

  13. Matching the oculomotor drive during head-restrained and head-unrestrained gaze shifts in monkey.

    PubMed

    Bechara, Bernard P; Gandhi, Neeraj J

    2010-08-01

    High-frequency burst neurons in the pons provide the eye velocity command (equivalently, the primary oculomotor drive) to the abducens nucleus for generation of the horizontal component of both head-restrained (HR) and head-unrestrained (HU) gaze shifts. We sought to characterize how gaze and its eye-in-head component differ when an "identical" oculomotor drive is used to produce HR and HU movements. To address this objective, the activities of pontine burst neurons were recorded during horizontal HR and HU gaze shifts. The burst profile recorded on each HU trial was compared with the burst waveform of every HR trial obtained for the same neuron. The oculomotor drive was assumed to be comparable for the pair yielding the lowest root-mean-squared error. For matched pairs of HR and HU trials, the peak eye-in-head velocity was substantially smaller in the HU condition, and the reduction was usually greater than the peak head velocity of the HU trial. A time-varying attenuation index, defined as the difference in HR and HU eye velocity waveforms divided by head velocity [alpha = (H(hr) - E(hu))/H] was computed. The index was variable at the onset of the gaze shift, but it settled at values several times greater than 1. The index then decreased gradually during the movement and stabilized at 1 around the end of gaze shift. These results imply that substantial attenuation in eye velocity occurs, at least partially, downstream of the burst neurons. We speculate on the potential roles of burst-tonic neurons in the neural integrator and various cell types in the vestibular nuclei in mediating the attenuation in eye velocity in the presence of head movements.

  14. Zero torque gear head wrench

    NASA Technical Reports Server (NTRS)

    Mcdougal, A. R.; Norman, R. M. (Inventor)

    1976-01-01

    A gear head wrench particularly suited for use in applying torque to bolts without transferring torsional stress to bolt-receiving structures is introduced. The wrench is characterized by a coupling including a socket, for connecting a bolt head with a torque multiplying gear train, provided within a housing having an annulus concentrically related to the socket and adapted to be coupled with a spacer interposed between the bolt head and the juxtaposed surface of the bolt-receiving structure for applying a balancing counter-torque to the spacer as torque is applied to the bolt head whereby the bolt-receiving structure is substantially isolated from torsional stress. As a result of the foregoing, the operator of the wrench is substantially isolated from any forces which may be imposed.

  15. Mutations in type 3 reovirus that determine binding to sialic acid are contained in the fibrous tail domain of viral attachment protein sigma1.

    PubMed

    Chappell, J D; Gunn, V L; Wetzel, J D; Baer, G S; Dermody, T S

    1997-03-01

    The reovirus attachment protein, sigma1, determines numerous aspects of reovirus-induced disease, including viral virulence, pathways of spread, and tropism for certain types of cells in the central nervous system. The sigma1 protein projects from the virion surface and consists of two distinct morphologic domains, a virion-distal globular domain known as the head and an elongated fibrous domain, termed the tail, which is anchored into the virion capsid. To better understand structure-function relationships of sigma1 protein, we conducted experiments to identify sequences in sigma1 important for viral binding to sialic acid, a component of the receptor for type 3 reovirus. Three serotype 3 reovirus strains incapable of binding sialylated receptors were adapted to growth in murine erythroleukemia (MEL) cells, in which sialic acid is essential for reovirus infectivity. MEL-adapted (MA) mutant viruses isolated by serial passage in MEL cells acquired the capacity to bind sialic acid-containing receptors and demonstrated a dependence on sialic acid for infection of MEL cells. Analysis of reassortant viruses isolated from crosses of an MA mutant virus and a reovirus strain that does not bind sialic acid indicated that the sigma1 protein is solely responsible for efficient growth of MA mutant viruses in MEL cells. The deduced sigma1 amino acid sequences of the MA mutant viruses revealed that each strain contains a substitution within a short region of sequence in the sigma1 tail predicted to form beta-sheet. These studies identify specific sequences that determine the capacity of reovirus to bind sialylated receptors and suggest a location for a sialic acid-binding domain. Furthermore, the results support a model in which type 3 sigma1 protein contains discrete receptor binding domains, one in the head and another in the tail that binds sialic acid.

  16. Domain Engineering

    NASA Astrophysics Data System (ADS)

    Bjørner, Dines

    Before software can be designed we must know its requirements. Before requirements can be expressed we must understand the domain. So it follows, from our dogma, that we must first establish precise descriptions of domains; then, from such descriptions, “derive” at least domain and interface requirements; and from those and machine requirements design the software, or, more generally, the computing systems.

  17. 29 CFR 1620.21 - Head of household.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Head of household. 1620.21 Section 1620.21 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE EQUAL PAY ACT § 1620.21 Head of household. Since a “head of household” or “head of family” status bears no relationship to the...

  18. Visualizing domain wall and reverse domain superconductivity.

    PubMed

    Iavarone, M; Moore, S A; Fedor, J; Ciocys, S T; Karapetrov, G; Pearson, J; Novosad, V; Bader, S D

    2014-08-28

    In magnetically coupled, planar ferromagnet-superconductor (F/S) hybrid structures, magnetic domain walls can be used to spatially confine the superconductivity. In contrast to a superconductor in a uniform applied magnetic field, the nucleation of the superconducting order parameter in F/S structures is governed by the inhomogeneous magnetic field distribution. The interplay between the superconductivity localized at the domain walls and far from the walls leads to effects such as re-entrant superconductivity and reverse domain superconductivity with the critical temperature depending upon the location. Here we use scanning tunnelling spectroscopy to directly image the nucleation of superconductivity at the domain wall in F/S structures realized with Co-Pd multilayers and Pb thin films. Our results demonstrate that such F/S structures are attractive model systems that offer the possibility to control the strength and the location of the superconducting nucleus by applying an external magnetic field, potentially useful to guide vortices for computing application.

  19. Visualizing domain wall and reverse domain superconductivity

    PubMed Central

    Iavarone, M.; Moore, S. A.; Fedor, J.; Ciocys, S. T.; Karapetrov, G.; Pearson, J.; Novosad, V.; Bader, S. D.

    2014-01-01

    In magnetically coupled, planar ferromagnet-superconductor (F/S) hybrid structures, magnetic domain walls can be used to spatially confine the superconductivity. In contrast to a superconductor in a uniform applied magnetic field, the nucleation of the superconducting order parameter in F/S structures is governed by the inhomogeneous magnetic field distribution. The interplay between the superconductivity localized at the domain walls and far from the walls leads to effects such as re-entrant superconductivity and reverse domain superconductivity with the critical temperature depending upon the location. Here we use scanning tunnelling spectroscopy to directly image the nucleation of superconductivity at the domain wall in F/S structures realized with Co-Pd multilayers and Pb thin films. Our results demonstrate that such F/S structures are attractive model systems that offer the possibility to control the strength and the location of the superconducting nucleus by applying an external magnetic field, potentially useful to guide vortices for computing application. PMID:25164004

  20. Analysis of SAR distribution in human head of antenna used in wireless power transform based on magnetic resonance.

    PubMed

    Gong, Feixiang; Wei, Zhiqiang; Cong, Yanping; Chi, Haokun; Yin, Bo; Sun, Mingui

    2017-07-20

    In this paper, a novel wireless power transfer antenna system was designed for human head implantable devices. The antenna system used the structure of three plates and four coils and operated at low frequencies to transfer power via near field. In order to verify the electromagnetic radiation safety on the human head, the electromagnetic intensity and specific absorption rate (SAR) were studied by finite-difference-time-domain (FDTD) method. A three-layer model of human head including skin, bone and brain tissues was constructed. The transmitting and receiving antenna were set outside and inside the model. The local and average SAR were simulated at the resonance frequency of 18.67 MHz in two situations, in one scenario both transmitting and receiving coil worked, while in the other scenario only the transmitting coil worked. The results showed that the maximum of 10 g SAR average value of human thoracic were 0.142 W/kg and 0.148 W/kg, respectively, both were lower than the international safety standards for human body of the ICNIRP and FCC, which verified the safety of the human body in wireless power transmission based on magnetic coupling resonance.

  1. Study of the influence of the laterality of mobile phone use on the SAR induced in two head models

    NASA Astrophysics Data System (ADS)

    Ghanmi, Amal; Varsier, Nadège; Hadjem, Abdelhamid; Conil, Emmanuelle; Picon, Odile; Wiart, Joe

    2013-05-01

    The objective of this paper is to investigate and to analyse the influence of the laterality of mobile phone use on the exposure of the brain to radio-frequencies (RF) and electromagnetic fields (EMF) from different mobile phone models using the finite-difference time-domain (FDTD) method. The study focuses on the comparison of the specific absorption rate (SAR) induced on the right and left sides of two numerical adult and child head models. The heads are exposed by both phone models operating in GSM frequency bands for both ipsilateral and contralateral configurations. A slight SAR difference between the two sides of the heads is noted. The results show that the variation between the left and the right sides is more important at 1800 MHz for an ipsilateral use. Indeed, at this frequency, the variation can even reach 20% for the SAR10g and the SAR1g induced in the head and in the brain, respectively. Moreover, the average SAR induced by the mobile phone in the half hemisphere of the brain in ipsilateral exposure is higher than in contralateral exposure. Owing to the superficial character of energy deposition at 1800 MHz, this difference in the SAR induced for the ipsilateral and contralateral usages is more significant at 1800 MHz than at 900 MHz. The results have shown that depending on the phantom head models, the SAR distribution in the brain can vary because of differences in anatomical proportions and in the geometry of the head models. The induced SAR in child head and in sub-regions of the brain is significantly higher (up to 30%) compared to the adult head. This paper confirms also that the shape/design of the mobile and the location of the antenna can have a large influence at high frequency on the exposure of the brain, particularly on the SAR distribution and on the distinguished brain regions.

  2. 21 CFR 868.1930 - Stethoscope head.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food... DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification. A stethoscope head is a weighted chest piece used during anesthesia to listen to a patient's heart, breath, and...

  3. 29 CFR 1926.100 - Head protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Head protection. 1926.100 Section 1926.100 Labor... § 1926.100 Head protection. (a) Employees working in areas where there is a possible danger of head... protected by protective helmets. (b) Helmets for the protection of employees against impact and penetration...

  4. Domain Specific vs Domain General: Implications for Dynamic Assessment

    ERIC Educational Resources Information Center

    Kaniel, Shlomo

    2010-01-01

    The article responds to the need for evidence-based dynamic assessment. The article is divided into two sections: In Part 1 we examine the scientific answer to the question of how far human mental activities and capabilities are domain general (DG) / domain specific (DS). A highly complex answer emerges from the literature review of domains such…

  5. Electro-optic voltage sensor head

    DOEpatents

    Crawford, T.M.; Davidson, J.R.; Woods, G.K.

    1999-08-17

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers. 6 figs.

  6. Electro-optic voltage sensor head

    DOEpatents

    Crawford, Thomas M.; Davidson, James R.; Woods, Gregory K.

    1999-01-01

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers.

  7. Head Start on Science Preliminary Findings.

    ERIC Educational Resources Information Center

    Ritz, William C.; Von Blum, Ruth

    For many Head Start teachers and staff, the word "science" conjures up uncomfortable feelings and memories. The purpose of this project--a collaborative effort of California State University, Long Beach and the Head Start Program of Long Beach Unified School District (LBUSD)--was to prepare Head Start staff to become more capable,…

  8. Development of the head and trunk mesoderm in the dogfish, Scyliorhinus torazame: II. Comparison of gene expression between the head mesoderm and somites with reference to the origin of the vertebrate head.

    PubMed

    Adachi, Noritaka; Takechi, Masaki; Hirai, Tamami; Kuratani, Shigeru

    2012-01-01

    The vertebrate mesoderm differs distinctly between the head and trunk, and the evolutionary origin of the head mesoderm remains enigmatic. Although the presence of somite-like segmentation in the head mesoderm of model animals is generally denied at molecular developmental levels, the appearance of head cavities in elasmobranch embryos has not been explained, and the possibility that they may represent vestigial head somites once present in an amphioxus-like ancestor has not been ruled out entirely. To examine whether the head cavities in the shark embryo exhibit any molecular signatures reminiscent of trunk somites, we isolated several developmentally key genes, including Pax1, Pax3, Pax7, Pax9, Myf5, Sonic hedgehog, and Patched2, which are involved in myogenic and chondrogenic differentiation in somites, and Pitx2, Tbx1, and Engrailed2, which are related to the patterning of the head mesoderm, from an elasmobranch species, Scyliorhinus torazame. Observation of the expression patterns of these genes revealed that most were expressed in patterns that resembled those found in amniote embryos. In addition, the head cavities did not exhibit an overt similarity to somites; that is, the similarity was no greater than that of the unsegmented head mesoderm in other vertebrates. Moreover, the shark head mesoderm showed an amniote-like somatic/visceral distinction according to the expression of Pitx2, Tbx1, and Engrailed2. We conclude that the head cavities do not represent a manifestation of ancestral head somites; rather, they are more likely to represent a derived trait obtained in the lineage of gnathostomes. © 2012 Wiley Periodicals, Inc.

  9. The Video Head Impulse Test.

    PubMed

    Halmagyi, G M; Chen, Luke; MacDougall, Hamish G; Weber, Konrad P; McGarvie, Leigh A; Curthoys, Ian S

    2017-01-01

    In 1988, we introduced impulsive testing of semicircular canal (SCC) function measured with scleral search coils and showed that it could accurately and reliably detect impaired function even of a single lateral canal. Later we showed that it was also possible to test individual vertical canal function in peripheral and also in central vestibular disorders and proposed a physiological mechanism for why this might be so. For the next 20 years, between 1988 and 2008, impulsive testing of individual SCC function could only be accurately done by a few aficionados with the time and money to support scleral search-coil systems-an expensive, complicated and cumbersome, semi-invasive technique that never made the transition from the research lab to the dizzy clinic. Then, in 2009 and 2013, we introduced a video method of testing function of each of the six canals individually. Since 2009, the method has been taken up by most dizzy clinics around the world, with now close to 100 refereed articles in PubMed. In many dizzy clinics around the world, video Head Impulse Testing has supplanted caloric testing as the initial and in some cases the final test of choice in patients with suspected vestibular disorders. Here, we consider seven current, interesting, and controversial aspects of video Head Impulse Testing: (1) introduction to the test; (2) the progress from the head impulse protocol (HIMPs) to the new variant-suppression head impulse protocol (SHIMPs); (3) the physiological basis for head impulse testing; (4) practical aspects and potential pitfalls of video head impulse testing; (5) problems of vestibulo-ocular reflex gain calculations; (6) head impulse testing in central vestibular disorders; and (7) to stay right up-to-date-new clinical disease patterns emerging from video head impulse testing. With thanks and appreciation we dedicate this article to our friend, colleague, and mentor, Dr Bernard Cohen of Mount Sinai Medical School, New York, who since his first

  10. The Two Faces of Secondary Headship: Women Deputy Head Teachers' Perceptions of the Secondary Head Teacher Role

    ERIC Educational Resources Information Center

    Guihen, Laura

    2017-01-01

    Men continue to outnumber women at the secondary head teacher level. This article reports on some of the preliminary findings of a larger study exploring the ways in which women deputy head teachers, as potential aspirants to headship, perceive the secondary head teacher role. Using an Interpretative Phenomenological Analysis methodology,…

  11. Three-dimensional templating arthroplasty of the humeral head.

    PubMed

    Cho, Sung Won; Jharia, Trambak K; Moon, Young Lae; Sim, Sung Woo; Shin, Dong Sun; Bigliani, Louis U

    2013-10-01

    No anatomical study has been conducted over Asian population to design humeral head prosthesis for the population concerned. This study was done to evaluate the accuracy of commercially available humeral head prosthetic designs, in replicating the humeral head anatomy. CT scan data of 48 patients were taken and their 3D CAD models were generated. Then, humeral head prosthetic design of a BF shoulder system produced by a standardized, commercially available company (Zimmer) was used for templating shoulder arthroplasty and the humeral head size having the perfect fit was assessed. These data were compared with the available data in the literature. All the humeral heads were perfectly matched by one of the sizes available. The average head size was 48.5 mm and the average head thickness was 23.5 mm. The results matched reasonably well with the available data in the literature. The humeral head anatomy can be recreated reasonably well by the commercially available humeral head prosthetic designs and sizes. Their dimensions are similar to that of the published literature.

  12. Covariance analysis for evaluating head trackers

    NASA Astrophysics Data System (ADS)

    Kang, Donghoon

    2017-10-01

    Existing methods for evaluating the performance of head trackers usually rely on publicly available face databases, which contain facial images and the ground truths of their corresponding head orientations. However, most of the existing publicly available face databases are constructed by assuming that a frontal head orientation can be determined by compelling the person under examination to look straight ahead at the camera on the first video frame. Since nobody can accurately direct one's head toward the camera, this assumption may be unrealistic. Rather than obtaining estimation errors, we present a method for computing the covariance of estimation error rotations to evaluate the reliability of head trackers. As an uncertainty measure of estimators, the Schatten 2-norm of a square root of error covariance (or the algebraic average of relative error angles) can be used. The merit of the proposed method is that it does not disturb the person under examination by asking him to direct his head toward certain directions. Experimental results using real data validate the usefulness of our method.

  13. 49 CFR 572.82 - Head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.82 Head. The head consists of the assembly shown in drawing LP 1049/A and conforms to each of the applicable drawings listed...

  14. Head-first impact with head protrusion causes noncontiguous injuries of the cadaveric cervical spine.

    PubMed

    Ivancic, Paul C

    2012-09-01

    To simulate horizontally aligned head-first impacts with initial head protrusion using a human cadaveric neck model and to determine biomechanical responses, injuries, and injury severity. Head-first impacts with initial head protrusion were simulated at 2.4 m/s using a human cadaver neck model (n = 10) mounted horizontally to a torso-equivalent mass on a sled and carrying a surrogate head. Macroscopic neck injuries were determined, and ligamentous injuries were quantified using fluoroscopy and visual inspection after the impacts. Representative time-history responses for injured specimens were determined during impact using load cell data and analyses of high-speed video. Biomechanics research laboratory. Cervical spines of 10 human cadavers. Injury severity at the middle and lower cervical spine was statistically compared using a 2-sample t test (P < 0.05). Neck buckling consisted of hyperflexion at C6/7 and C7/T1 and hyperextension at superior spinal levels. Noncontiguous neck injuries included forward dislocation at C7/T1, spinous process fracture and compression-extension injuries at the middle cervical spine, and atlas and odontoid fractures. Ligamentous injury severity at C7/T1 was significantly greater than at the middle cervical spine. Distinct injury mechanisms were observed throughout the neck, consisting of extension-compression and posterior shear at the upper and middle cervical spine and flexion-compression and anterior shear at C6/7 and C7/T1. Our experimental results highlight the importance of clinical awareness of potential noncontiguous cervical spine injuries due to head-first sports impacts.

  15. A numerical solution to define channel heads and hillslope parameters from digital topography of glacially conditioned catchments

    NASA Astrophysics Data System (ADS)

    Salcher, Bernhard; Baumann, Sebastian; Kober, Florian; Robl, Jörg; Heiniger, Lukas

    2016-04-01

    The analysis of the slope-area relationship in bedrock streams is a common way for discriminating the channel from the hillslope domain and associated landscape processes. Spatial variations of these domains are important indicators of landscape change. In fluvial catchments, this relationship is a function of contributing drainage area, channel slope and the threshold drainage area for fluvial erosion. The resulting pattern is related to climate, tectonic and underlying bedrock. These factors may become secondary in catchments affected by glacial erosion, as it is the case in many mid- to high-latitude mountain belts. The perturbation (i.e. the destruction) of an initial steady state fluvial bedrock morphology (where uplift is balanced by surface lowering rates) will tend to become successively larger if the repeated action of glacial processes exceeds the potential of fluvial readjustment during deglaciated periods. Topographic change is associated with a decrease and fragmentation of the channel network and an extension of the hillslope domain. In case of glacially conditioned catchments discrimination of the two domains remains problematic and a discrimination inconsistent. A definition is therefore highly needed considering that (i) a spatial shift in the domains affect the process and rate of erosion and (ii) topographic classifications of alpine catchments often base on channel and hillslope parameters (i.e.channel or hillslope relief). Here we propose a novel numerical approach to topographically define channel heads from digital topography in glacially conditioned mountain range catchments in order to discriminate the channel from the hillslope domain. We analyzed the topography of the southern European Central Alps, a region which (i) has been glaciated multiple times during the Quaternary, shows (ii) little lithological variations, is (iii) home of very low erodible rocks and is (iv) known as a region were tectonic processes have largely ceased. The

  16. Prediction value of the Canadian CT head rule and the New Orleans criteria for positive head CT scan and acute neurosurgical procedures in minor head trauma: a multicenter external validation study.

    PubMed

    Bouida, Wahid; Marghli, Soudani; Souissi, Sami; Ksibi, Hichem; Methammem, Mehdi; Haguiga, Habib; Khedher, Sonia; Boubaker, Hamdi; Beltaief, Kaouthar; Grissa, Mohamed Habib; Trimech, Mohamed Naceur; Kerkeni, Wiem; Chebili, Nawfel; Halila, Imen; Rejeb, Imen; Boukef, Riadh; Rekik, Noureddine; Bouhaja, Bechir; Letaief, Mondher; Nouira, Semir

    2013-05-01

    The New Orleans Criteria and the Canadian CT Head Rule have been developed to decrease the number of normal computed tomography (CT) results in mild head injury. We compare the performance of both decision rules for identifying patients with intracranial traumatic lesions and those who require an urgent neurosurgical intervention after mild head injury. This was an observational cohort study performed between 2008 and 2011 on patients with mild head injury who were aged 10 years or older. We collected prospectively clinical head CT scan findings and outcome. Primary outcome was need for neurosurgical intervention, defined as either death or craniotomy, or the need of intubation within 15 days of the traumatic event. Secondary outcome was the presence of traumatic lesions on head CT scan. New Orleans Criteria and Canadian CT Head Rule decision rules were compared by using sensitivity specifications and positive and negative predictive value. We enrolled 1,582 patients. Neurosurgical intervention was performed in 34 patients (2.1%) and positive CT findings were demonstrated in 218 patients (13.8%). Sensitivity and specificity for need for neurosurgical intervention were 100% (95% confidence interval [CI] 90% to 100%) and 60% (95% CI 44% to 76%) for the Canadian CT Head Rule and 82% (95% CI 69% to 95%) and 26% (95% CI 24% to 28%) for the New Orleans Criteria. Negative predictive values for the above-mentioned clinical decision rules were 100% and 99% and positive values were 5% and 2%, respectively, for the Canadian CT Head Rule and New Orleans Criteria. Sensitivity and specificity for clinical significant head CT findings were 95% (95% CI 92% to 98%) and 65% (95% CI 62% to 68%) for the Canadian CT Head Rule and 86% (95% CI 81% to 91%) and 28% (95% CI 26% to 30%) for the New Orleans Criteria. A similar trend of results was found in the subgroup of patients with a Glasgow Coma Scale score of 15. For patients with mild head injury, the Canadian CT Head Rule had higher

  17. Head Lice: Prevention and Control

    MedlinePlus

    ... and General Public. Contact Us Parasites Home Prevention & Control Language: English (US) Español (Spanish) Recommend on Facebook ... that can be taken to help prevent and control the spread of head lice: Avoid head-to- ...

  18. Gas cushion control of OVJP print head position

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Forrest, Stephen R

    An OVJP apparatus and method for applying organic vapor or other flowable material to a substrate using a printing head mechanism in which the print head spacing from the substrate is controllable using a cushion of air or other gas applied between the print head and substrate. The print head is mounted for translational movement towards and away from the substrate and is biased toward the substrate by springs or other means. A gas cushion feed assembly supplies a gas under pressure between the print head and substrate which opposes the biasing of the print head toward the substrate somore » as to form a space between the print head and substrate. By controlling the pressure of gas supplied, the print head separation from the substrate can be precisely controlled.« less

  19. Acrylic Resin Molding Based Head Fixation Technique in Rodents.

    PubMed

    Roh, Mootaek; Lee, Kyungmin; Jang, Il-Sung; Suk, Kyoungho; Lee, Maan-Gee

    2016-01-12

    Head fixation is a technique of immobilizing animal's head by attaching a head-post on the skull for rigid clamping. Traditional head fixation requires surgical attachment of metallic frames on the skull. The attached frames are then clamped to a stationary platform resulting in immobilization of the head. However, metallic frames for head fixation have been technically difficult to design and implement in general laboratory environment. In this study, we provide a novel head fixation method. Using a custom-made head fixation bar, head mounter is constructed during implantation surgery. After the application of acrylic resin for affixing implants such as electrodes and cannula on the skull, additional resins applied on top of that to build a mold matching to the port of the fixation bar. The molded head mounter serves as a guide rails, investigators conveniently fixate the animal's head by inserting the head mounter into the port of the fixation bar. This method could be easily applicable if implantation surgery using dental acrylics is necessary and might be useful for laboratories that cannot easily fabricate CNC machined metal head-posts.

  20. Head circumference in young children with autism: the impact of different head circumference charts.

    PubMed

    Morhardt, Duncan R; Barrow, William; Jaworski, Margie; Accardo, Pasquale J

    2014-03-01

    The hypothesis that the presence of macrocephaly might vary with the specific growth chart used was tested by using the Nellahus, CDC, and recent Rollins et al revision head circumference charts to plot the head circumferences of 253 children with neurodevelopmental disorders and with ages between 12 to 36 months; of these children, 59 had a diagnosis of autism spectrum disorder. The CDC and Rollins et al head circumference charts identified more cases of macrocephaly and fewer cases of microcephaly than did the older Nellhaus chart but did not significantly differ in their identification of macrocephaly in children with autism.

  1. Head patterning and Hox gene expression in an onychophoran and its implications for the arthropod head problem.

    PubMed

    Eriksson, Bo Joakim; Tait, Noel N; Budd, Graham E; Janssen, Ralf; Akam, Michael

    2010-09-01

    The arthropod head problem has puzzled zoologists for more than a century. The head of adult arthropods is a complex structure resulting from the modification, fusion and migration of an uncertain number of segments. In contrast, onychophorans, which are the probable sister group to the arthropods, have a rather simple head comprising three segments that are well defined during development, and give rise to the adult head with three pairs of appendages specialised for sensory and food capture/manipulative purposes. Based on the expression pattern of the anterior Hox genes labial, proboscipedia, Hox3 and Deformed, we show that the third of these onychophoran segments, bearing the slime papillae, can be correlated to the tritocerebrum, the most anterior Hox-expressing arthropod segment. This implies that both the onychophoran antennae and jaws are derived from a more anterior, Hox-free region corresponding to the proto and deutocerebrum of arthropods. Our data provide molecular support for the proposal that the onychophoran head possesses a well-developed appendage that corresponds to the anterior, apparently appendage-less region of the arthropod head.

  2. Domain-to-domain coupling in voltage-sensing phosphatase.

    PubMed

    Sakata, Souhei; Matsuda, Makoto; Kawanabe, Akira; Okamura, Yasushi

    2017-01-01

    Voltage-sensing phosphatase (VSP) consists of a transmembrane voltage sensor and a cytoplasmic enzyme region. The enzyme region contains the phosphatase and C2 domains, is structurally similar to the tumor suppressor phosphatase PTEN, and catalyzes the dephosphorylation of phosphoinositides. The transmembrane voltage sensor is connected to the phosphatase through a short linker region, and phosphatase activity is induced upon membrane depolarization. Although the detailed molecular characteristics of the voltage sensor domain and the enzyme region have been revealed, little is known how these two regions are coupled. In addition, it is important to know whether mechanism for coupling between the voltage sensor domain and downstream effector function is shared among other voltage sensor domain-containing proteins. Recent studies in which specific amino acid sites were genetically labeled using a fluorescent unnatural amino acid have enabled detection of the local structural changes in the cytoplasmic region of Ciona intestinalis VSP that occur with a change in membrane potential. The results of those studies provide novel insight into how the enzyme activity of the cytoplasmic region of VSP is regulated by the voltage sensor domain.

  3. Domain-to-domain coupling in voltage-sensing phosphatase

    PubMed Central

    Sakata, Souhei; Matsuda, Makoto; Kawanabe, Akira; Okamura, Yasushi

    2017-01-01

    Voltage-sensing phosphatase (VSP) consists of a transmembrane voltage sensor and a cytoplasmic enzyme region. The enzyme region contains the phosphatase and C2 domains, is structurally similar to the tumor suppressor phosphatase PTEN, and catalyzes the dephosphorylation of phosphoinositides. The transmembrane voltage sensor is connected to the phosphatase through a short linker region, and phosphatase activity is induced upon membrane depolarization. Although the detailed molecular characteristics of the voltage sensor domain and the enzyme region have been revealed, little is known how these two regions are coupled. In addition, it is important to know whether mechanism for coupling between the voltage sensor domain and downstream effector function is shared among other voltage sensor domain-containing proteins. Recent studies in which specific amino acid sites were genetically labeled using a fluorescent unnatural amino acid have enabled detection of the local structural changes in the cytoplasmic region of Ciona intestinalis VSP that occur with a change in membrane potential. The results of those studies provide novel insight into how the enzyme activity of the cytoplasmic region of VSP is regulated by the voltage sensor domain. PMID:28744425

  4. Head-Neck Biomechanics in Simulated Rear Impact

    PubMed Central

    Yoganandan, Narayan; Pintar, Frank A.; Cusick, Joseph F.; Kleinberger, Michael

    1998-01-01

    The first objective of this study is to present an overview of the human cadaver studies aimed to determine the biomechanics of the head-neck in a simulated rear crash. The need for kinematic studies to better understand the mechanisms of load transfer to the human head-neck complex is emphasized. Based on this need, a methodology is developed to delineate the dynamic kinematics of the human head-neck complex. Intact human cadaver head-neck complexes were subjected to postero-anterior impact using a mini-sled pendulum device. The integrity of the soft tissues including the musculature and skin were maintained. The kinematic data were recorded using high-speed photography coupled with retroreflective targets placed at various regions of the human head-neck complex. The overall and segmental kinematics of the entire head-neck complex, and the localized facet joint motions were determined. During the initial stages of loading, a transient decoupling of the head occurred with respect to the neck exhibiting a lag of the cranium. The upper cervical spine-head undergoes local flexion concomitant with a lag of the head while the lower cervical spinal column is in local extension. This establishes a reverse curvature to the cervical head-neck complex. With continued loading, head motion ensues and approximately at the end of the loading phase, the entire head-neck complex is under the extension mode with a single curvature. In contrast, the lower cervical spine facet joint kinematics show varying compression and sliding. While both the anterior and posterior-most regions of the facet joint slide, the posterior-most region (mean: 2.84 mm) of the joint compresses more than the anterior-most (mean: 2.02 mm) region. These varying kinematics at the ends of the facet joint result in a pinching mechanism. These biomechanical kinematic findings may be correlated to the presence of headaches and neck pain (Lord, Bogduk et al. 1992; Barnsley, Lord et al. 1995), based on the unique

  5. Skyrmion domain wall collision and domain wall-gated skyrmion logic

    NASA Astrophysics Data System (ADS)

    Xing, Xiangjun; Pong, Philip W. T.; Zhou, Yan

    2016-08-01

    Skyrmions and domain walls are significant spin textures of great technological relevance to magnetic memory and logic applications, where they can be used as carriers of information. The unique topology of skyrmions makes them display emergent dynamical properties as compared with domain walls. Some studies have demonstrated that the two topologically inequivalent magnetic objects could be interconverted by using cleverly designed geometric structures. Here, we numerically address the skyrmion domain wall collision in a magnetic racetrack by introducing relative motion between the two objects based on a specially designed junction. An electric current serves as the driving force that moves a skyrmion toward a trapped domain wall pair. We see different types of collision dynamics depending on the driving parameters. Most importantly, the modulation of skyrmion transport using domain walls is realized in this system, allowing a set of domain wall-gated logical NOT, NAND, and NOR gates to be constructed. This work provides a skyrmion-based spin-logic architecture that is fully compatible with racetrack memories.

  6. MIT domain of Vps4 is a Ca2+-dependent phosphoinositide-binding domain.

    PubMed

    Iwaya, Naoko; Takasu, Hirotoshi; Goda, Natsuko; Shirakawa, Masahiro; Tanaka, Toshiki; Hamada, Daizo; Hiroaki, Hidekazu

    2013-05-01

    The microtubule interacting and trafficking (MIT) domain is a small protein module that is conserved in proteins of diverged function, such as Vps4, spastin and sorting nexin 15 (SNX15). The molecular function of the MIT domain is protein-protein interaction, in which the domain recognizes peptides containing MIT-interacting motifs. Recently, we identified an evolutionarily related domain, 'variant' MIT domain at the N-terminal region of the microtubule severing enzyme katanin p60. We found that the domain was responsible for binding to microtubules and Ca(2+). Here, we have examined whether the authentic MIT domains also bind Ca(2+). We found that the loop between the first and second α-helices of the MIT domain binds a Ca(2+) ion. Furthermore, the MIT domains derived from Vps4b and SNX15a showed phosphoinositide-binding activities in a Ca(2+)-dependent manner. We propose that the MIT domain is a novel membrane-associating domain involved in endosomal trafficking.

  7. Cutting Head for Ultrasonic Lithotripsy

    NASA Technical Reports Server (NTRS)

    Angulo, E. D.; Goodfriend, R.

    1987-01-01

    Kidney stones lodged in urinary tract disintegrated with increased safety and efficiency by cutting head attached to end of vibrated wire probe. Aligns probe with stone and enables probe to vibrate long enough to disintegrate stone. Design of cutting head reduces risk of metal-fatigue-induced breakage of probe tip leaving metal fragments in urinary tract. Teeth of cutting head both seat and fragment kidney stone, while extension of collar into catheter lessens mechanical strain in probe wire, increasing probe life and lessening danger of in situ probe breakage.

  8. 49 CFR 572.6 - Head.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... nose when the midsagittal plane is vertical. (2) Drop the head from the specified height by means that... drawings subtended by number SA 150 M010. (b) When the head is dropped from a height of 10 inches in...

  9. 49 CFR 572.6 - Head.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... nose when the midsagittal plane is vertical. (2) Drop the head from the specified height by means that... drawings subtended by number SA 150 M010. (b) When the head is dropped from a height of 10 inches in...

  10. 49 CFR 572.6 - Head.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... nose when the midsagittal plane is vertical. (2) Drop the head from the specified height by means that... drawings subtended by number SA 150 M010. (b) When the head is dropped from a height of 10 inches in...

  11. Resource development in otolaryngology-head and neck surgery: an analysis on patient education resource development.

    PubMed

    Goldfarb, Jeremy; Gupta, Vishaal; Sampson, Heather; Chiodo, Albino

    2014-01-01

    There is a need for educational tools in the consenting process of otolaryngology-head and neck procedures. A development strategy for the creation of educational tools in otolaryngology-head and neck surgery, particularly pamphlets on the peri-operative period in an adenotonsillectomy, is described. A participatory design approach, which engages key stakeholders in the development of an educational tool, is used. Pamphlets were created through a review of traditional and grey literature and then reviewed by a community expert in the field. The pamphlets were then reviewed by an interdisciplinary team including educational experts, and finally by less vulnerable members of the target population. Questionnaires evaluating the pamphlets' content, layout, style, and general qualitative features were included. The pamphlets yielded high ratings across all domains regardless of patient population. General feedback was provided by a non-vulnerable patient population and final pamphlets were drafted. By using a participatory design model, the pamphlets are written at an appropriate educational level to incorporate a broad audience. Furthermore, this methodology can be used in future resource development of educational tools.

  12. Resource development in otolaryngology-head and neck surgery: an analysis on patient education resource development

    PubMed Central

    2014-01-01

    Background There is a need for educational tools in the consenting process of otolaryngology-head and neck procedures. A development strategy for the creation of educational tools in otolaryngology-head and neck surgery, particularly pamphlets on the peri-operative period in an adenotonsillectomy, is described. Methods A participatory design approach, which engages key stakeholders in the development of an educational tool, is used. Pamphlets were created through a review of traditional and grey literature and then reviewed by a community expert in the field. The pamphlets were then reviewed by an interdisciplinary team including educational experts, and finally by less vulnerable members of the target population. Questionnaires evaluating the pamphlets’ content, layout, style, and general qualitative features were included. Results The pamphlets yielded high ratings across all domains regardless of patient population. General feedback was provided by a non-vulnerable patient population and final pamphlets were drafted. Conclusions By using a participatory design model, the pamphlets are written at an appropriate educational level to incorporate a broad audience. Furthermore, this methodology can be used in future resource development of educational tools. PMID:25022351

  13. Kinematics of the human mandible for different head postures.

    PubMed

    Visscher, C M; Huddleston Slater, J J; Lobbezoo, F; Naeije, M

    2000-04-01

    The influence of head posture on movement paths of the incisal point (IP) and of the mandibular condyles during free open-close movements was studied. Ten persons, without craniomandibular or cervical spine disorders, participated in the study. Open close mandibular movements were recorded with the head in five postures, viz., natural head posture, forward head posture, military posture, and lateroflexion to the right and to the left side, using the Oral Kinesiologic Analysis System (OKAS-3D). This study showed that in a military head posture, the opening movement path of the incisal point is shifted anteriorly relative to the path in a natural head posture. In a forward head posture, the movement path is shifted posteriorly whereas during lateroflexion, it deviates to the side the head has moved to. Moreover, the intra-articular distance in the temporomandibular joint during closing is smaller with the head in military posture and greater in forward head posture, as compared to the natural head posture. During lateroflexion, the intra-articular distance on the ipsilateral side is smaller. The influence of head posture upon the kinematics of the mandible is probably a manifestation of differences in mandibular loading in the different head postures.

  14. Trithorax Group Protein Oryza sativa Trithorax1 Controls Flowering Time in Rice via Interaction with Early heading date31[W][OPEN

    PubMed Central

    Choi, Sang Chul; Lee, Shinyoung; Kim, Sung-Ryul; Lee, Yang-Seok; Liu, Chunyan; Cao, Xiaofeng; An, Gynheung

    2014-01-01

    Trithorax group proteins are chromatin-remodeling factors that activate target gene expression by antagonistically functioning against the Polycomb group. In Arabidopsis (Arabidopsis thaliana), Arabidopsis Trithorax protein1 (ATX1) regulates flowering time and floral organ identity. Here, we observed that suppression of Oryza sativa Trithorax1 (OsTrx1), an ortholog of ATX1, delayed flowering time in rice (Oryza sativa). Because the delay occurred only under long-day conditions, we evaluated the flowering signal pathways that specifically function under long-day conditions. Among them, the OsMADS50 and Heading date1 pathways were not affected by the mutation. However, the Grain number, plant height, and heading date7 (Ghd7) pathway was altered in ostrx1. Transcript levels of OsGI, phytochrome genes, and Early heading date3 (Ehd3), which function upstream of Ghd7, were unchanged in the mutant. Because Trx group proteins form a complex with other proteins to modify the chromatin structure of target genes, we investigated whether OsTrx1 interacts with a previously identified protein that functions upstream of Ghd7. We demonstrated that the plant homeodomain motif of OsTrx1 binds to native histone H3 from the calf thymus and that OsTrx1 binds to Ehd3 through the region between the plant homeodomain and SET domains. Finally, we showed that the SET domain at the C-terminal end of OsTrx1 has histone H3 methyltransferase activity when incubated with oligonucleosomes. Our results suggest that OsTrx1 plays an important role in regulating flowering time in rice by modulating chromatin structure. PMID:24420930

  15. The use of health related quality of life data to produce information sheets for patients with head and neck cancer.

    PubMed

    Rogers, S N; Hogg, E S; Cheung, W K A; Lai, L K L; Jassal, P; Lowe, D

    2015-07-01

    Health related quality of life information gives patients and carers an indication of how they will be affected following treatment. Such knowledge can promote realistic expectations and help patients come to terms with their outcome. The aim of this paper is to describe the background development of patient information sheets produced at our unit. The data were compiled using a common head and neck cancer specific quality of life questionnaire (University of Washington Quality of Life [UW-QOL]). There are 12 domains comprising activity, appearance, anxiety, chewing, mood, pain, recreation, saliva, shoulder, speech, swallowing and taste. The data were collected over 19 years at our unit and focus on follow-up records at around 2 years as this gives a good indication of health related quality of life in survivorship. UW-QOL questionnaires were available from 1,511 patients treated following primary diagnosis of head and neck cancer, and there were 24 subgroups based on cancer site, stage and treatment. There were 2 other subgroups: 132 having transoral laser resection and 176 having laryngectomy. The patient and carer research forum helped to design the information sheets, which display overall quality of life, percentages with 'good' outcome and 'significant problem' by domain, and the most important domains. Three examples are included in this paper: early stage oral cancer treated by surgery alone, early laryngeal cancer treated by surgery alone, and late stage oropharyngeal cancer treated by surgery and postoperative radiotherapy. All 26 subgroup information sheets are available in booklet form and on the internet. How the surgical community best utilises this type of resource needs further research.

  16. Learning toward practical head pose estimation

    NASA Astrophysics Data System (ADS)

    Sang, Gaoli; He, Feixiang; Zhu, Rong; Xuan, Shibin

    2017-08-01

    Head pose is useful information for many face-related tasks, such as face recognition, behavior analysis, human-computer interfaces, etc. Existing head pose estimation methods usually assume that the face images have been well aligned or that sufficient and precise training data are available. In practical applications, however, these assumptions are very likely to be invalid. This paper first investigates the impact of the failure of these assumptions, i.e., misalignment of face images, uncertainty and undersampling of training data, on head pose estimation accuracy of state-of-the-art methods. A learning-based approach is then designed to enhance the robustness of head pose estimation to these factors. To cope with misalignment, instead of using hand-crafted features, it seeks suitable features by learning from a set of training data with a deep convolutional neural network (DCNN), such that the training data can be best classified into the correct head pose categories. To handle uncertainty and undersampling, it employs multivariate labeling distributions (MLDs) with dense sampling intervals to represent the head pose attributes of face images. The correlation between the features and the dense MLD representations of face images is approximated by a maximum entropy model, whose parameters are optimized on the given training data. To estimate the head pose of a face image, its MLD representation is first computed according to the model based on the features extracted from the image by the trained DCNN, and its head pose is then assumed to be the one corresponding to the peak in its MLD. Evaluation experiments on the Pointing'04, FacePix, Multi-PIE, and CASIA-PEAL databases prove the effectiveness and efficiency of the proposed method.

  17. Head lice: the feelings people have.

    PubMed

    Parison, Julie C; Speare, Richard; Canyon, Deon V

    2013-02-01

    Head lice are a source of amusement for outsiders and an embarrassing nuisance to those who have to deal with them. Our study collected the emotions experienced by people dealing with head lice. An area with extremely sparse literature, our purpose is to inform the development of more effective programs to control head lice. We asked "what were your feelings upon discovery of head lice?" as part of a study exploring the experience of those treating head lice. A short questionnaire was available via the authors' head lice information internet site. A total of 294 eligible responses were collected over several months and analyzed, supported by QSR N6. The predominantly female (90 · 9%) respondents were residents of Australia (56 · 1%), USA (20 · 4%), Canada (7 · 2%), or UK (4 · 4%), and working full-time (43·0%) or part-time (34 · 2%). Reactions and feelings fell into three categories: strong (n = 320; 79% of all stated emotions), mediocre (n = 56; 20%), and neutral (n = 29; 9 · 8%). There were no positive emotions. The significant negative reaction was expected. The range of feeling expressed demonstrates the stigma held for these ectoparasites within western market economies. This contrasts with conceptions of head lice in traditional societies. The negative social effects of this perception create more problematic issues than the infection itself; these include quarantine, overtreatment, and a potentially negative psychological impact. Head lice control strategies and programs that address these negative emotional reactions may prove more effective than current biomedical focus. © 2013 The International Society of Dermatology.

  18. Head and neck cancer in South Asia: Macroeconomic consequences and the role of the head and neck surgeon.

    PubMed

    Alkire, Blake C; Bergmark, Regan W; Chambers, Kyle; Lin, Derrick T; Deschler, Daniel G; Cheney, Mack L; Meara, John G

    2016-08-01

    Head and neck cancer constitutes a substantial portion of the burden of disease in South Asia, and there is an undersupply of surgical capacity in this region. The purpose of this study was to estimate the economic welfare losses due to head and neck cancer in India, Pakistan, and Bangladesh in 2010. We used publicly available estimates of head and neck cancer morbidity and mortality along with a concept termed the value of a statistical life to estimate economic welfare losses in the aforementioned countries in 2010. Economic losses because of head and neck cancer in India, Pakistan, and Bangladesh totaled $16.9 billion (2010 US dollars [USD]), equivalent to 0.26% of the region's economic output. Bangladesh, the poorest country, experienced the greatest proportional losses. The economic consequences of head and neck cancer in South Asia are significant, and building surgical capacity is essential to begin to address this burden. © 2016 Wiley Periodicals, Inc. Head Neck 38:1242-1247, 2016. © 2016 Wiley Periodicals, Inc.

  19. Nano-oxide-layer specular spin valve heads with synthetic pinned layer: Head performance and reliability

    NASA Astrophysics Data System (ADS)

    Hasegawa, N.; Koike, F.; Ikarashi, K.; Ishizone, M.; Kawamura, M.; Nakazawa, Y.; Takahashi, A.; Tomita, H.; Iwasaki, H.; Sahashi, M.

    2002-05-01

    To implement the specular nano-oxide-layer (NOL) spin valve (SV) heads for use in practical applications, it is key to simultaneously achieve a good specular effect of the NOL inserted in the synthetic ferrimagnet pinned layer (i.e., high magnetoresistance MR performance) and a strong pinning field through the NOL. By using CoFe+X as a substance to be subjected to oxidation, we obtained the NOL specular SV films simultaneously achieving a high MR ratio of 17%-18% and a high pinning field of 1100-1500 Oe. Narrow track (0.12 μm) heads were fabricated and they showed a high sensitivity of 10 mV/μm. Several reliability tests were done both at the sheet film level and the actual head level. The oxygen inside NOL was found to be stable up to 350 °C, and pinned layer magnetization canting after orthogonal field annealing was found to be almost the same as today's non-NOL SV films. An electrostatic discharge test and accelerated lifetime test were also performed and NOL specular heads were demonstrated to have almost the same robustness as today's non-NOL heads.

  20. Head and Neck Cancer: Symptoms and Signs

    MedlinePlus

    ... and Neck Cancer: Symptoms and Signs Request Permissions Head and Neck Cancer: Symptoms and Signs Approved by the Cancer. ... f t k e P Types of Cancer Head and Neck Cancer Guide Cancer.Net Guide Head and Neck ...

  1. Marshall Space Flight Center head development program

    NASA Technical Reports Server (NTRS)

    Harrer, Jim

    1994-01-01

    This report summarizes the results of the candidate head evaluation for the new long-life magnetic head per the SOW of Contract No. NAS8-39407, MSFC Head Development Program. The original program plans were to test a candidate head, fabricate a new head, then qualify the new head. These activities were scheduled to be carried out between March 1993 and March 1994. The program was halted after the evaluation of the candidate head by NAS8-39407 Amendment No. 4. MSFC has provided and authorized the use the MARS-2000 SRB QUAL Recorder PN 10400-0677-801 - Serial Number 200004 (Datatape PN 591000 - Serial Number 1004), Reproduce Amplifier Module (RAM) Datatape PN 533040 - Serial Number 2006, associated cables, and magnetic tape on special SRB/DFI tapered reels to Datatape for this program. All the testing that has been done for the candidate head evaluation was done at Datatape's facility in Pasadena,CA. The testing was performed in a Class 100,000 particle counts clean room at ambient temperature, except for the thermal testing which was conducted in a different area at Datatape. The Performance Verification Test Procedure PVT-11004-4 (PVT) and Acceptance Test Procedure ATP-11004-09 (ATP) procedures were used when tests were conducted on the recorder.

  2. Predicting detection performance with model observers: Fourier domain or spatial domain?

    PubMed

    Chen, Baiyu; Yu, Lifeng; Leng, Shuai; Kofler, James; Favazza, Christopher; Vrieze, Thomas; McCollough, Cynthia

    2016-02-27

    The use of Fourier domain model observer is challenged by iterative reconstruction (IR), because IR algorithms are nonlinear and IR images have noise texture different from that of FBP. A modified Fourier domain model observer, which incorporates nonlinear noise and resolution properties, has been proposed for IR and needs to be validated with human detection performance. On the other hand, the spatial domain model observer is theoretically applicable to IR, but more computationally intensive than the Fourier domain method. The purpose of this study is to compare the modified Fourier domain model observer to the spatial domain model observer with both FBP and IR images, using human detection performance as the gold standard. A phantom with inserts of various low contrast levels and sizes was repeatedly scanned 100 times on a third-generation, dual-source CT scanner at 5 dose levels and reconstructed using FBP and IR algorithms. The human detection performance of the inserts was measured via a 2-alternative-forced-choice (2AFC) test. In addition, two model observer performances were calculated, including a Fourier domain non-prewhitening model observer and a spatial domain channelized Hotelling observer. The performance of these two mode observers was compared in terms of how well they correlated with human observer performance. Our results demonstrated that the spatial domain model observer correlated well with human observers across various dose levels, object contrast levels, and object sizes. The Fourier domain observer correlated well with human observers using FBP images, but overestimated the detection performance using IR images.

  3. Predicting detection performance with model observers: Fourier domain or spatial domain?

    PubMed Central

    Chen, Baiyu; Yu, Lifeng; Leng, Shuai; Kofler, James; Favazza, Christopher; Vrieze, Thomas; McCollough, Cynthia

    2016-01-01

    The use of Fourier domain model observer is challenged by iterative reconstruction (IR), because IR algorithms are nonlinear and IR images have noise texture different from that of FBP. A modified Fourier domain model observer, which incorporates nonlinear noise and resolution properties, has been proposed for IR and needs to be validated with human detection performance. On the other hand, the spatial domain model observer is theoretically applicable to IR, but more computationally intensive than the Fourier domain method. The purpose of this study is to compare the modified Fourier domain model observer to the spatial domain model observer with both FBP and IR images, using human detection performance as the gold standard. A phantom with inserts of various low contrast levels and sizes was repeatedly scanned 100 times on a third-generation, dual-source CT scanner at 5 dose levels and reconstructed using FBP and IR algorithms. The human detection performance of the inserts was measured via a 2-alternative-forced-choice (2AFC) test. In addition, two model observer performances were calculated, including a Fourier domain non-prewhitening model observer and a spatial domain channelized Hotelling observer. The performance of these two mode observers was compared in terms of how well they correlated with human observer performance. Our results demonstrated that the spatial domain model observer correlated well with human observers across various dose levels, object contrast levels, and object sizes. The Fourier domain observer correlated well with human observers using FBP images, but overestimated the detection performance using IR images. PMID:27239086

  4. Domain-General and Domain-Specific Strategies for the Assessment of Distress Intolerance

    PubMed Central

    McHugh, R. Kathryn; Otto, Michael W.

    2011-01-01

    Recent research has provided evidence that distress intolerance—the perceived inability to tolerate distressing states—varies based on the domain of distress (e.g., pain, anxiety). Although domain-specific assessment strategies may provide information targeted to specific disorders or maladaptive behaviors, domain-general measures have the potential to facilitate comparisons across studies, disorders, and populations. The current study evaluated the utilization of self-report measures of distress intolerance as domain-general measures by examining their association with indices of behavioral avoidance and substance craving. Two groups of participants (N = 55) were recruited including a substance-dependent group and a comparison group equated based on the presence of an affective disorder. Results provided support for the validity of domain-general measures for assessing distress intolerance across varied domains. The importance of both domain-general and domain-specific measurement of distress intolerance is discussed. PMID:21823763

  5. The Video Head Impulse Test

    PubMed Central

    Halmagyi, G. M.; Chen, Luke; MacDougall, Hamish G.; Weber, Konrad P.; McGarvie, Leigh A.; Curthoys, Ian S.

    2017-01-01

    In 1988, we introduced impulsive testing of semicircular canal (SCC) function measured with scleral search coils and showed that it could accurately and reliably detect impaired function even of a single lateral canal. Later we showed that it was also possible to test individual vertical canal function in peripheral and also in central vestibular disorders and proposed a physiological mechanism for why this might be so. For the next 20 years, between 1988 and 2008, impulsive testing of individual SCC function could only be accurately done by a few aficionados with the time and money to support scleral search-coil systems—an expensive, complicated and cumbersome, semi-invasive technique that never made the transition from the research lab to the dizzy clinic. Then, in 2009 and 2013, we introduced a video method of testing function of each of the six canals individually. Since 2009, the method has been taken up by most dizzy clinics around the world, with now close to 100 refereed articles in PubMed. In many dizzy clinics around the world, video Head Impulse Testing has supplanted caloric testing as the initial and in some cases the final test of choice in patients with suspected vestibular disorders. Here, we consider seven current, interesting, and controversial aspects of video Head Impulse Testing: (1) introduction to the test; (2) the progress from the head impulse protocol (HIMPs) to the new variant—suppression head impulse protocol (SHIMPs); (3) the physiological basis for head impulse testing; (4) practical aspects and potential pitfalls of video head impulse testing; (5) problems of vestibulo-ocular reflex gain calculations; (6) head impulse testing in central vestibular disorders; and (7) to stay right up-to-date—new clinical disease patterns emerging from video head impulse testing. With thanks and appreciation we dedicate this article to our friend, colleague, and mentor, Dr Bernard Cohen of Mount Sinai Medical School, New York, who since his

  6. The exploding head syndrome.

    PubMed

    Green, M W

    2001-06-01

    This article reviews the features of an uncommon malady termed "the exploding head syndrome." Sufferers describe terrorizing attacks of a painless explosion within their head. Attacks tend to occur at the onset of sleep. The etiology of attacks is unknown, although they are considered to be benign. Treatment with clomipramine has been suggested, although most sufferers require only reassurance that the spells are benign in nature.

  7. Integrated head package for top mounted nuclear instrumentation

    DOEpatents

    Malandra, Louis J.; Hornak, Leonard P.; Meuschke, Robert E.

    1993-01-01

    A nuclear reactor such as a pressurized water reactor has an integrated head package providing structural support and increasing shielding leading toward the vessel head. A reactor vessel head engages the reactor vessel, and a control rod guide mechanism over the vessel head raises and lowers control rods in certain of the thimble tubes, traversing penetrations in the reactor vessel head, and being coupled to the control rods. An instrumentation tube structure includes instrumentation tubes with sensors movable into certain thimble tubes disposed in the fuel assemblies. Couplings for the sensors also traverse penetrations in the reactor vessel head. A shroud is attached over the reactor vessel head and encloses the control rod guide mechanism and at least a portion of the instrumentation tubes when retracted. The shroud forms a structural element of sufficient strength to support the vessel head, the control rod guide mechanism and the instrumentation tube structure, and includes radiation shielding material for limiting passage of radiation from retracted instrumentation tubes. The shroud is thicker at the bottom adjacent the vessel head, where the more irradiated lower ends of retracted sensors reside. The vessel head, shroud and contents thus can be removed from the reactor as a unit and rested safely and securely on a support.

  8. Eye-Pursuit and Reafferent Head Movement Signals Carried by Pursuit Neurons in the Caudal Part of the Frontal Eye Fields during Head-Free Pursuit

    PubMed Central

    Kasahara, Satoshi; Akao, Teppei; Kurkin, Sergei; Peterson, Barry W.

    2009-01-01

    Eye and head movements are coordinated during head-free pursuit. To examine whether pursuit neurons in frontal eye fields (FEF) carry gaze-pursuit commands that drive both eye-pursuit and head-pursuit, monkeys whose heads were free to rotate about a vertical axis were trained to pursue a juice feeder with their head and a target with their eyes. Initially the feeder and target moved synchronously with the same visual angle. FEF neurons responding to this gaze-pursuit were tested for eye-pursuit of target motion while the feeder was stationary and for head-pursuit while the target was stationary. The majority of pursuit neurons exhibited modulation during head-pursuit, but their preferred directions during eye-pursuit and head-pursuit were different. Although peak modulation occurred during head movements, the onset of discharge usually was not aligned with the head movement onset. The minority of neurons whose discharge onset was so aligned discharged after the head movement onset. These results do not support the idea that the head-pursuit–related modulation reflects head-pursuit commands. Furthermore, modulation similar to that during head-pursuit was obtained by passive head rotation on stationary trunk. Our results suggest that FEF pursuit neurons issue gaze or eye movement commands during gaze-pursuit and that the head-pursuit–related modulation primarily reflects reafferent signals resulting from head movements. PMID:18483002

  9. Probabilistic description of infant head kinematics in abusive head trauma.

    PubMed

    Lintern, T O; Nash, M P; Kelly, P; Bloomfield, F H; Taberner, A J; Nielsen, P M F

    2017-12-01

    Abusive head trauma (AHT) is a potentially fatal result of child abuse, but the mechanisms by which injury occur are often unclear. To investigate the contention that shaking alone can elicit the injuries observed, effective computational models are necessary. The aim of this study was to develop a probabilistic model describing infant head kinematics in AHT. A deterministic model incorporating an infant's mechanical properties, subjected to different shaking motions, was developed in OpenSim. A Monte Carlo analysis was used to simulate the range of infant kinematics produced as a result of varying both the mechanical properties and the type of shaking motions. By excluding physically unrealistic shaking motions, worst-case shaking scenarios were simulated and compared to existing injury criteria for a newborn, a 4.5 month-old, and a 12 month-old infant. In none of the three cases were head kinematics observed to exceed previously-estimated subdural haemorrhage injury thresholds. The results of this study provide no biomechanical evidence to demonstrate how shaking by a human alone can cause the injuries observed in AHT, suggesting either that additional factors, such as impact, are required, or that the current estimates of injury thresholds are incorrect.

  10. Heading Tuning in Macaque Area V6.

    PubMed

    Fan, Reuben H; Liu, Sheng; DeAngelis, Gregory C; Angelaki, Dora E

    2015-12-16

    Cortical areas, such as the dorsal subdivision of the medial superior temporal area (MSTd) and the ventral intraparietal area (VIP), have been shown to integrate visual and vestibular self-motion signals. Area V6 is interconnected with areas MSTd and VIP, allowing for the possibility that V6 also integrates visual and vestibular self-motion cues. An alternative hypothesis in the literature is that V6 does not use these sensory signals to compute heading but instead discounts self-motion signals to represent object motion. However, the responses of V6 neurons to visual and vestibular self-motion cues have never been studied, thus leaving the functional roles of V6 unclear. We used a virtual reality system to examine the 3D heading tuning of macaque V6 neurons in response to optic flow and inertial motion stimuli. We found that the majority of V6 neurons are selective for heading defined by optic flow. However, unlike areas MSTd and VIP, V6 neurons are almost universally unresponsive to inertial motion in the absence of optic flow. We also explored the spatial reference frames of heading signals in V6 by measuring heading tuning for different eye positions, and we found that the visual heading tuning of most V6 cells was eye-centered. Similar to areas MSTd and VIP, the population of V6 neurons was best able to discriminate small variations in heading around forward and backward headings. Our findings support the idea that V6 is involved primarily in processing visual motion signals and does not appear to play a role in visual-vestibular integration for self-motion perception. To understand how we successfully navigate our world, it is important to understand which parts of the brain process cues used to perceive our direction of self-motion (i.e., heading). Cortical area V6 has been implicated in heading computations based on human neuroimaging data, but direct measurements of heading selectivity in individual V6 neurons have been lacking. We provide the first

  11. Migration from full-head mask to "open-face" mask for immobilization of patients with head and neck cancer.

    PubMed

    Li, Guang; Lovelock, D Michael; Mechalakos, James; Rao, Shyam; Della-Biancia, Cesar; Amols, Howard; Lee, Nancy

    2013-09-06

    To provide an alternative device for immobilization of the head while easing claustrophobia and improving comfort, an "open-face" thermoplastic mask was evaluated using video-based optical surface imaging (OSI) and kilovoltage (kV) X-ray radiography. A three-point thermoplastic head mask with a precut opening and reinforced strips was developed. After molding, it provided sufficient visible facial area as the region of interest for OSI. Using real-time OSI, the head motion of ten volunteers in the new mask was evaluated during mask locking and 15minutes lying on the treatment couch. Using a nose mark with reference to room lasers, forced head movement in open-face and full-head masks (with a nose hole) was compared. Five patients with claustrophobia were immobilized with open-face masks, set up using OSI and kV, and treated in 121 fractions, in which 61 fractions were monitored during treatment using real-time OSI. With the open-face mask, head motion was found to be 1.0 ± 0.6 mm and 0.4° ± 0.2° in volunteers during the experiment, and 0.8 ± 0.3 mm and 0.4° ± 0.2° in patients during treatment. These agree with patient motion calculated from pre-/post-treatment OSI and kV data using different anatomical landmarks. In volunteers, the head shift induced by mask-locking was 2.3 ± 1.7 mm and 1.8° ± 0.6°, and the range of forced movements in the open-face and full-head masks were found to be similar. Most (80%) of the volunteers preferred the open-face mask to the full-head mask, while claustrophobic patients could only tolerate the open-face mask. The open-face mask is characterized for its immobilization capability and can immobilize patients sufficiently (< 2 mm) during radiotherapy. It provides a clinical solution to the immobilization of patients with head and neck (HN) cancer undergoing radiotherapy, and is particularly beneficial for claustrophobic patients. This new open-face mask is readily adopted in radiotherapy clinic as a superior alternative

  12. 49 CFR 572.6 - Head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head. 572.6 Section 572.6 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 50th Percentile Male § 572.6 Head. (a) The...

  13. 49 CFR 572.6 - Head.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Head. 572.6 Section 572.6 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 50th Percentile Male § 572.6 Head. (a) The...

  14. Contribution of trimeric autotransporter C-terminal domains of oligomeric coiled-coil adhesin (Oca) family members YadA, UspA1, EibA, and Hia to translocation of the YadA passenger domain and virulence of Yersinia enterocolitica.

    PubMed

    Ackermann, Nikolaus; Tiller, Maximilian; Anding, Gisela; Roggenkamp, Andreas; Heesemann, Jürgen

    2008-07-01

    The Oca family is a novel class of autotransporter-adhesins with highest structural similarity in their C-terminal transmembrane region, which supposedly builds a beta-barrel pore in the outer membrane (OM). The prototype of the Oca family is YadA, an adhesin of Yersinia enterocolitica and Yersinia pseudotuberculosis. YadA forms a homotrimeric lollipop-like structure on the bacterial surface. The C-terminal regions of three YadA monomers form a barrel in the OM and translocate the trimeric N-terminal passenger domain, consisting of stalk, neck, and head region to the exterior. To elucidate the structural and functional role of the C-terminal translocator domain (TLD) and to assess its promiscuous capability with respect to transport of related passenger domains, we constructed chimeric YadA proteins, which consist of the N-terminal YadA passenger domain and C-terminal TLDs of Oca family members UspA1 (Moraxella catarrhalis), EibA (Escherichia coli), and Hia (Haemophilus influenzae). These constructs were expressed in Y. enterocolitica and compared for OM localization, surface exposure, oligomerization, adhesion properties, serum resistance, and mouse virulence. We demonstrate that all chimeric YadA proteins translocated the YadA passenger domain across the OM. Y. enterocolitica strains producing YadA chimeras or wild-type YadA showed comparable binding to collagen and epithelial cells. However, strains producing YadA chimeras were attenuated in serum resistance and mouse virulence. These results demonstrate for the first time that TLDs of Oca proteins of different origin are efficient translocators of the YadA passenger domain and that the cognate TLD of YadA is essential for bacterial survival in human serum and mouse virulence.

  15. Topiramate Responsive Exploding Head Syndrome

    PubMed Central

    Palikh, Gaurang M.; Vaughn, Bradley V.

    2010-01-01

    Exploding head syndrome is a rare phenomenon but can be a significant disruption to quality of life. We describe a 39-year-old female with symptoms of a loud bang and buzz at sleep onset for 3 years. EEG monitoring confirmed these events occurred in transition from stage 1 sleep. This patient reported improvement in intensity of events with topiramate medication. Based on these results, topiramate may be an alternative method to reduce the intensity of events in exploding head syndrome. Citation: Palikh GM; Vaughn BV. Topiramate responsive exploding head syndrome. J Clin Sleep Med 2010;6(4):382-383. PMID:20726288

  16. Thermoregulatory response to intraoperative head-down tilt.

    PubMed

    Nakajima, Yasufumi; Mizobe, Toshiki; Matsukawa, Takashi; Sessler, Daniel I; Kitamura, Yoshihiro; Tanaka, Yoshifumi

    2002-01-01

    Thermoregulation interacts with cardiovascular regulation within the central nervous system. We therefore evaluated the effects of head-down tilt on intraoperative thermal and cardiovascular regulation. Thirty-two patients undergoing lower-abdominal surgery were randomly assigned to the 1) supine, 2) 15 degrees -20 degrees head-down tilt, 3) leg-up, or 4) combination of leg-up and head-down tilt position. Core temperature and forearm minus fingertip skin-temperature gradients (an index of peripheral vasoconstriction) were monitored for 3 h after the induction of combined general and lumbar epidural anesthesia. We also determined cardiac output and central-venous and esophageal pressures. Neither right atrial transmural pressure nor cardiac index was altered in the Head-Down Tilt group, but both increased significantly in the Leg-Up groups. The vasoconstriction threshold was reduced in both leg-up positions but was not significantly decreased by head-down tilt. Final core temperatures were 35.2 degrees C +/- 0.2 degrees C (mean +/- SEM) in the Supine group, 35.0 degrees C +/- 0.2 degrees C in the Head-Down Tilt group, 34.2 degrees C +/- 0.2 degrees C in the Leg-Up group (P < 0.05 compared with supine), and 34.3 degrees C +/- 0.2 degrees C when leg-up and head-down tilt were combined (P < 0.05 compared with supine). These results confirm that elevating the legs increases right atrial transmural pressure, reduces the vasoconstriction threshold, and aggravates intraoperative hypothermia. Surprisingly, maintaining a head-down tilt did not increase right atrial pressure. Intraoperative hypothermia is exaggerated when patients are maintained in the leg-up position because the vasoconstriction threshold is reduced. However, head-down tilt (Trendelenburg position) does not reduce the vasoconstriction threshold or aggravate hypothermia. The head-down tilt position thus does not require special perioperative thermal precautions or management unless the leg-up position is used

  17. Head-Impact-Measurement Devices: A Systematic Review.

    PubMed

    O'Connor, Kathryn L; Rowson, Steven; Duma, Stefan M; Broglio, Steven P

    2017-03-01

    With an estimated 3.8 million sport- and recreation-related concussions occurring annually, targeted prevention and diagnostic methods are needed. Biomechanical analysis of head impacts may provide quantitative information that can inform both prevention and diagnostic strategies. To assess available head-impact devices and their clinical utility. We performed a systematic search of the electronic database PubMed for peer-reviewed publications, using the following phrases: accelerometer and concussion, head impact telemetry, head impacts and concussion and sensor, head impacts and sensor, impact sensor and concussion, linear acceleration and concussion, rotational acceleration and concussion, and xpatch concussion. In addition to the literature review, a Google search for head impact monitor and concussion monitor yielded 15 more devices. Included studies were performed in vivo, used commercially available devices, and focused on sport-related concussion. One author reviewed the title and abstract of each study for inclusion and exclusion criteria and then reviewed each full-text article to confirm inclusion criteria. Controversial articles were reviewed by all authors to reach consensus. In total, 61 peer-reviewed articles involving 4 head-impact devices were included. Participants in boxing, football, ice hockey, soccer, or snow sports ranged in age from 6 to 24 years; 18% (n = 11) of the studies included female athletes. The Head Impact Telemetry System was the most widely used device (n = 53). Fourteen additional commercially available devices were presented. Measurements collected by impact monitors provided real-time data to estimate player exposure but did not have the requisite sensitivity to concussion. Proper interpretation of previously reported head-impact kinematics across age, sport, and position may inform future research and enable staff clinicians working on the sidelines to monitor athletes. However, head-impact-monitoring systems have limited

  18. Narrow-headed garter snake (Thamnophis rufipunctatus)

    USGS Publications Warehouse

    Nowak, Erika M.

    2006-01-01

    The narrow-headed garter snake is a harmless, nonvenomous snake that is distinguished by its elongated, triangular-shaped head and the red or dark spots on its olive to tan body. Today, the narrow-headed garter snake is a species of special concern in the United States because of its decline over much of its historic range. Arizona's Oak Creek has historically contained the largest population of narrow-headed garter snakes in the United States. The U.S. Geological Survey (USGS) and the Arizona Game and Fish Department jointly funded research by USGS scientists in Oak Creek to shed light on the factors causing declining population numbers. The research resulted in better understanding of the snake's habitat needs, winter and summer range, and dietary habits. Based on the research findings, the U.S. Forest Service has developed recommendations that visitors and local residents can adopt to help slow the decline of the narrow-headed garter snake in Oak Creek.

  19. Spatiotopic coding during dynamic head tilt

    PubMed Central

    Turi, Marco; Burr, David C.

    2016-01-01

    Humans maintain a stable representation of the visual world effortlessly, despite constant movements of the eyes, head, and body, across multiple planes. Whereas visual stability in the face of saccadic eye movements has been intensely researched, fewer studies have investigated retinal image transformations induced by head movements, especially in the frontal plane. Unlike head rotations in the horizontal and sagittal planes, tilting the head in the frontal plane is only partially counteracted by torsional eye movements and consequently induces a distortion of the retinal image to which we seem to be completely oblivious. One possible mechanism aiding perceptual stability is an active reconstruction of a spatiotopic map of the visual world, anchored in allocentric coordinates. To explore this possibility, we measured the positional motion aftereffect (PMAE; the apparent change in position after adaptation to motion) with head tilts of ∼42° between adaptation and test (to dissociate retinal from allocentric coordinates). The aftereffect was shown to have both a retinotopic and spatiotopic component. When tested with unpatterned Gaussian blobs rather than sinusoidal grating stimuli, the retinotopic component was greatly reduced, whereas the spatiotopic component remained. The results suggest that perceptual stability may be maintained at least partially through mechanisms involving spatiotopic coding. NEW & NOTEWORTHY Given that spatiotopic coding could play a key role in maintaining visual stability, we look for evidence of spatiotopic coding after retinal image transformations caused by head tilt. To this end, we measure the strength of the positional motion aftereffect (PMAE; previously shown to be largely spatiotopic after saccades) after large head tilts. We find that, as with eye movements, the spatial selectivity of the PMAE has a large spatiotopic component after head rotation. PMID:27903636

  20. Head Injuries

    MedlinePlus

    ... before. Often, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...

  1. A new principle technic for the transformation from frequency domain to time domain

    NASA Astrophysics Data System (ADS)

    Gao, Ben-Qing

    2017-03-01

    A principle technic for the transformation from frequency domain to time domain is presented. Firstly, a special type of frequency domain transcendental equation is obtained for an expected frequency domain parameter which is a rational or irrational fraction expression. Secondly, the inverse Laplace transformation is performed. When the two time-domain factors corresponding to the two frequency domain factors at two sides of frequency domain transcendental equation are known quantities, a time domain transcendental equation is reached. At last, the expected time domain parameter corresponding to the expected frequency domain parameter can be solved by the inverse convolution process. Proceeding from rational or irrational fraction expression, all solving process is provided. In the meantime, the property of time domain sequence is analyzed and the strategy for choosing the parameter values is described. Numerical examples are presented to verify the proposed theory and technic. Except for rational or irrational fraction expressions, examples of complex relative permittivity of water and plasma are used as verification method. The principle method proposed in the paper can easily solve problems which are difficult to be solved by Laplace transformation.

  2. Stress Domain Effects in French Phonology and Phonological Development.

    PubMed

    Rose, Yvan; Dos Santos, Christophe

    In this paper, we discuss two distinct data sets. The first relates to the so-called allophonic process of closed-syllable laxing in Québec French, which targets final (stressed) vowels even though these vowels are arguably syllabified in open syllables in lexical representations. The second is found in the forms produced by a first language learner of European French, who displays an asymmetry in her production of CVC versus CVCV target (adult) forms. The former display full preservation (with concomitant manner harmony) of both consonants. The latter undergoes deletion of the initial syllable if the consonants are not manner-harmonic in the input. We argue that both patterns can be explained through a phonological process of prosodic strengthening targeting the head of the prosodic domain which, in the contexts described above, yields the incorporation of final consonants into the coda of the stressed syllable.

  3. Head-up transition behavior of pilots with and without head-up display in simulated low-visibility approaches

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Fischer, E.; Price, T. A.

    1980-01-01

    To quantify head-up transition behavior with and without a flightpath type head-up display, eight rated B-727 pilots each flew 31 manual and coupled approaches in a simulator with B-727 dynamics and collimated model board external scene. Data were also obtained on the roll played by the head-up display in the coupled-to-manual transition. Various wind shears, low visibilities, and ceilings were tested along with unexpected misalignment between the runway and head-up display symbology. The symbolic format used was a conformal scene. Every pilot except one stayed head-up, flying with the display after descending below the ceiling. Without the display and as altitude decreased, the number of lookups from the instrument panel decreased and the duration of each one increased. No large differences in mean number or duration of transitions up or down were found during the head-up display runs comparing the no-misalignment with the lateral instrument landing system offset misalignment runs. The head-up display led to fewer transitions after the pilot made a decision to land or execute a missed approach. Without the display, pilots generally waited until they had descended below the ceiling to look outside the first time, but with it several pilots looked down at their panel at relatively high altitudes (if they looked down at all). Manual takeover of control was rapid and smooth both with and without the display which permitted smoother engine power changes.

  4. A Logic for Inclusion of Administrative Domains and Administrators in Multi-domain Authorization

    NASA Astrophysics Data System (ADS)

    Iranmanesh, Zeinab; Amini, Morteza; Jalili, Rasool

    Authorization policies for an administrative domain or a composition of multiple domains in multi-domain environments are determined by either one administrator or multiple administrators' cooperation. Several logic-based models for multi-domain environments' authorization have been proposed; however, they have not considered administrators and administrative domains in policies' representation. In this paper, we propose the syntax, proof theory, and semantics of a logic for multi-domain authorization policies including administrators and administrative domains. Considering administrators in policies provides the possibility of presenting composite administration having applicability in many collaborative applications. Indeed, administrators and administrative domains stated in policies can be used in authorization. The presented logic is based on modal logic and utilizes two calculi named the calculus of administrative domains and the calculus of administrators. It is also proved that the logic is sound. A case study is presented signifying the logic application in practical projects.

  5. Head and Neck Cancer: An Overview

    PubMed Central

    Stepnick, David; Gilpin, David

    2010-01-01

    Ablative surgery for malignancies of the upper aerodigestive tract is the most common reason why the reconstructive surgeon is called upon to reconstruct adult head and neck defects. An understanding of the pathophysiology and treatment of head and neck malignancy is vital to the reconstructive surgeon so that restoration of both form and function can be achieved. It is important to understand the behavior of cancers of each head and neck subsite, as staging and ultimately the treatment of tumors from each subsite is different. Historically, the standard treatment of head and neck cancer was surgery and/or primary radiation therapy with surgical salvage for failure. Beginning in the 1980s, advances in chemotherapy and concurrent delivery with radiation offered new options to standard surgical therapy. Over the past two decades, the concept of organ preservation using chemotherapy together with radiation therapy has been definitively established. Yet, even with the strides made over these two decades with chemoradiation, surgical treatment of head and neck cancer and reconstruction thereof will be an important treatment option for the foreseeable future. Therefore, the relationship between the extirpative and reconstructive surgeon is vital, and a clear understanding of the biology and behavior of head and neck malignancy is crucial to successful patient outcomes. PMID:22550431

  6. Structure of the Three N-Terminal Immunoglobulin Domains of the Highly Immunogenic Outer Capsid Protein from a T4-Like Bacteriophage

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fokine, Andrei; Islam, Mohammad Z.; Zhang, Zhihong

    2011-09-16

    The head of bacteriophage T4 is decorated with 155 copies of the highly antigenic outer capsid protein (Hoc). One Hoc molecule binds near the center of each hexameric capsomer. Hoc is dispensable for capsid assembly and has been used to display pathogenic antigens on the surface of T4. Here we report the crystal structure of a protein containing the first three of four domains of Hoc from bacteriophage RB49, a close relative of T4. The structure shows an approximately linear arrangement of the protein domains. Each of these domains has an immunoglobulin-like fold, frequently found in cell attachment molecules. Inmore » addition, we report biochemical data suggesting that Hoc can bind to Escherichia coli, supporting the hypothesis that Hoc could attach the phage capsids to bacterial surfaces and perhaps also to other organisms. The capacity for such reversible adhesion probably provides survival advantages to the bacteriophage.« less

  7. Allicat magnetoresistive head design and performance

    NASA Astrophysics Data System (ADS)

    Hannon, David; Krounbi, Mohamed; Christner, Jodie

    1994-03-01

    The general design features of the magnetoresistive (MR) merged head are described and compared to the earlier MR piggy-back head called Corsair. Examples of static, magnetic, and error rate testing are given. Dual track profiles show the read-narrow feature of the MR head. Stability of the signal with write disturbance shows the effectiveness of the hard-bias longitudinal biasing. Error rate versus off-track position indicates the robustness of the file design.

  8. Reconstituting protein interaction networks using parameter-dependent domain-domain interactions

    PubMed Central

    2013-01-01

    Background We can describe protein-protein interactions (PPIs) as sets of distinct domain-domain interactions (DDIs) that mediate the physical interactions between proteins. Experimental data confirm that DDIs are more consistent than their corresponding PPIs, lending support to the notion that analyses of DDIs may improve our understanding of PPIs and lead to further insights into cellular function, disease, and evolution. However, currently available experimental DDI data cover only a small fraction of all existing PPIs and, in the absence of structural data, determining which particular DDI mediates any given PPI is a challenge. Results We present two contributions to the field of domain interaction analysis. First, we introduce a novel computational strategy to merge domain annotation data from multiple databases. We show that when we merged yeast domain annotations from six annotation databases we increased the average number of domains per protein from 1.05 to 2.44, bringing it closer to the estimated average value of 3. Second, we introduce a novel computational method, parameter-dependent DDI selection (PADDS), which, given a set of PPIs, extracts a small set of domain pairs that can reconstruct the original set of protein interactions, while attempting to minimize false positives. Based on a set of PPIs from multiple organisms, our method extracted 27% more experimentally detected DDIs than existing computational approaches. Conclusions We have provided a method to merge domain annotation data from multiple sources, ensuring large and consistent domain annotation for any given organism. Moreover, we provided a method to extract a small set of DDIs from the underlying set of PPIs and we showed that, in contrast to existing approaches, our method was not biased towards DDIs with low or high occurrence counts. Finally, we used these two methods to highlight the influence of the underlying annotation density on the characteristics of extracted DDIs. Although

  9. Head Injuries

    MedlinePlus

    ... won't stop crying complains of head and neck pain (younger or nonverbal children may be more fussy) ... vision pupils of unequal size weakness or paralysis neck pain or stiffness seizure If your child is unconscious: ...

  10. Sliding of microtubules by a team of dynein motors: Understanding the effect of spatial distribution of motor tails and mutual exclusion of motor heads on microtubules

    NASA Astrophysics Data System (ADS)

    Singh, Hanumant Pratap; Takshak, Anjneya; Mall, Utkarsh; Kunwar, Ambarish

    2016-06-01

    Molecular motors are natural nanomachines that use the free energy released from ATP hydrolysis to generate mechanical forces. Cytoplasmic dynein motors often work collectively as a team to drive important processes such as axonal growth, proplatelet formation and mitosis, as forces generated by single motors are insufficient. A large team of dynein motors is used to slide cytoskeletal microtubules with respect to one another during the process of proplatelet formation and axonal growth. These motors attach to a cargo microtubule via their tail domains, undergo the process of detachment and reattachment of their head domains on another track microtubule, while sliding the cargo microtubule along the track. Traditional continuum/mean-field approaches used in the past are not ideal for studying the sliding mechanism of microtubules, as they ignore spatial and temporal fluctuations due to different possible distributions of motor tails on cargo filament, as well as binding/unbinding of motors from their track. Therefore, these models cannot be used to address important questions such as how the distribution of motor tails on microtubules, or how the mutual exclusion of motor heads on microtubule tracks affects the sliding velocity of cargo microtubule. To answer these, here we use a computational stochastic model where we model each dynein motor explicitly. In our model, we use both random as well as uniform distributions of dynein motors on cargo microtubule, as well as mutual exclusion of motors on microtubule tracks. We find that sliding velocities are least affected by the distribution of motor tails on microtubules, whereas they are greatly affected by mutual exclusion of motor heads on microtubule tracks. We also find that sliding velocity depends on the length of cargo microtubule if mutual exclusion among motor heads is considered.

  11. Nanomedicines for Inflammatory Arthritis: Head-To-Head Comparison of Glucocorticoid-Containing Polymers, Micelles and Liposomes

    PubMed Central

    Crielaard, Bart J.; Dusad, Anand; Lele, Subodh M.; Rijcken, Cristianne J. F.; Metselaar, Josbert M; Kostková, Hana; Etrych, Tomáš; Ulbrich, Karel; Kiessling, Fabian; Mikuls, Ted R.; Hennink, Wim E.; Storm, Gert; Lammers, Twan; Wang, Dong

    2014-01-01

    As an emerging research direction, nanomedicine has been increasingly utilized to treat inflammatory diseases. In this head-to-head comparison study, four established nanomedicine formulations of dexamethasone, including liposomes (L-Dex), core-crosslinked micelles (M-Dex), slow releasing polymeric prodrugs (P-Dex-slow) and fast releasing polymeric prodrugs (P-Dex-fast), were evaluated in an adjuvant-induced arthritis rat model with an equivalent dose treatment design. It was found that after a single i.v. injection, the formulations with the slower drug release kinetics (i.e. M-Dex and P-Dex-slow) maintained longer duration of therapeutic activity than those with relatively faster drug release kinetics, resulting in better joint protection. This finding will be instructional in the future development and optimization of nanomedicines for the clinical management of rheumatoid arthritis. The outcome of this study also illustrates the value of such head-to-head comparison studies in translational nanomedicine research. PMID:24341611

  12. PREFACE: Domain wall dynamics in nanostructures Domain wall dynamics in nanostructures

    NASA Astrophysics Data System (ADS)

    Marrows, C. H.; Meier, G.

    2012-01-01

    Domain structures in magnetic materials are ubiquitous and have been studied for decades. The walls that separate them are topological defects in the magnetic order parameter and have a wide variety of complex forms. In general, their investigation is difficult in bulk materials since only the domain structure on the surface of a specimen is visible. Cutting the sample to reveal the interior causes a rearrangement of the domains into a new form. As with many other areas of magnetism, the study of domain wall physics has been revitalised by the advent of nanotechnology. The ability to fabricate nanoscale structures has permitted the formation of simplified and controlled domain patterns; the development of advanced microscopy methods has permitted them to be imaged and then modelled; subjecting them to ultrashort field and current pulses has permitted their dynamics to be explored. The latest results from all of these advances are described in this special issue. Not only has this led to results of great scientific beauty, but also to concepts of great applicability to future information technologies. In this issue the reader will find the latest results for these domain wall dynamics and the high-speed processes of topological structures such as domain walls and magnetic vortices. These dynamics can be driven by the application of magnetic fields, or by flowing currents through spintronic devices using the novel physics of spin-transfer torque. This complexity has been studied using a wide variety of experimental techniques at the edge of the spatial and temporal resolution currently available, and can be described using sophisticated analytical theory and computational modelling. As a result, the dynamics can be engineered to give rise to finely controlled memory and logic devices with new functionality. Moreover, the field is moving to study not only the conventional transition metal ferromagnets, but also complex heterostructures, novel magnets and even other

  13. Rat Cardiovascular Responses to Whole Body Suspension: Head-down and Non-Head-Down Tilt

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.; Steffen, Joseph M.; Dombrowski, Judy

    1992-01-01

    The rat whole body suspension technique mimics responses seen during exposure to microgravity and was evaluated as a model for cardiovascular responses with two series of experiments. In one series, changes were monitored in chronically catheterized rats during 7 days of Head-Down Tilt (HDT) or Non-Head-Down Tilt (N-HDT) and after several hours of recovery. Elevations of mean arterial (MAP), systolic, and diastolic pressures of approx. 20 % (P less than 0.05) in HDT rats began as early as day 1 and were maintained for the duration of suspension. Pulse pressures were relatively unaffected, but heart rates were elevated approx. 10 %. During postsuspension (2-7 h), most cardiovascular parameters returned to presuspension levels. N-HDT rats exhibited elevations chiefly on days 3 and 7. In the second series, blood pressure was monitored in 1- and 3-day HDT and N-HDT rats to evaluate responses to rapid head-up tilt. MAP, systolic and diastolic pressures, and HR were elevated (P less than 0.05) in HDT and N-HDT rats during head-up tilt after 1 day of suspension, while pulse pressures remained un changed. HDT rats exhibited elevated pretilt MAP and failed to respond to rapid head-up tilt with further increase of MAP on day 3, indicating some degree of deconditioning. The whole body suspended rat may be useful as a model to better understand responses of rats exposed to microgravity.

  14. Vacuum compatible miniature CCD camera head

    DOEpatents

    Conder, Alan D.

    2000-01-01

    A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

  15. Head Rotation Detection in Marmoset Monkeys

    NASA Astrophysics Data System (ADS)

    Simhadri, Sravanthi

    Head movement is known to have the benefit of improving the accuracy of sound localization for humans and animals. Marmoset is a small bodied New World monkey species and it has become an emerging model for studying the auditory functions. This thesis aims to detect the horizontal and vertical rotation of head movement in marmoset monkeys. Experiments were conducted in a sound-attenuated acoustic chamber. Head movement of marmoset monkey was studied under various auditory and visual stimulation conditions. With increasing complexity, these conditions are (1) idle, (2) sound-alone, (3) sound and visual signals, and (4) alert signal by opening and closing of the chamber door. All of these conditions were tested with either house light on or off. Infra-red camera with a frame rate of 90 Hz was used to capture of the head movement of monkeys. To assist the signal detection, two circular markers were attached to the top of monkey head. The data analysis used an image-based marker detection scheme. Images were processed using the Computation Vision Toolbox in Matlab. The markers and their positions were detected using blob detection techniques. Based on the frame-by-frame information of marker positions, the angular position, velocity and acceleration were extracted in horizontal and vertical planes. Adaptive Otsu Thresholding, Kalman filtering and bound setting for marker properties were used to overcome a number of challenges encountered during this analysis, such as finding image segmentation threshold, continuously tracking markers during large head movement, and false alarm detection. The results show that the blob detection method together with Kalman filtering yielded better performances than other image based techniques like optical flow and SURF features .The median of the maximal head turn in the horizontal plane was in the range of 20 to 70 degrees and the median of the maximal velocity in horizontal plane was in the range of a few hundreds of degrees per

  16. Quantifying Head Impacts in Collegiate Lacrosse.

    PubMed

    Reynolds, Bryson B; Patrie, James; Henry, Erich J; Goodkin, Howard P; Broshek, Donna K; Wintermark, Max; Druzgal, T Jason

    2016-11-01

    Concussion and repetitive head impact in sports has increased interest and concern for clinicians, scientists, and athletes. Lacrosse is the fastest growing sport in the United States, but the burden of head impact in lacrosse is unknown. The goal of this pilot study was to quantify head impact associated with practicing and playing collegiate lacrosse while subjects were fitted with wearable accelerometers. Descriptive epidemiology study. In a single year, a collegiate cohort of 14 women's and 15 men's lacrosse players wore mastoid-patch accelerometers to measure the frequency and severity of head impacts during official practices and games. Average impact severity, mean number of impacts, and cumulative acceleration were evaluated, stratified by sport and event type. Men's and women's collegiate lacrosse players did not significantly differ in the number of head impacts received during games (11.5 for men vs 9.2 for women) or practices (3.1 vs 3.1). Men's lacrosse players had significantly higher average head acceleration per impact during games compared with women (21.1g vs 14.7g) but not during practices (21.3g vs 18.1g). For both men and women, more impacts occurred during games than during practices (men, 11.5 vs 3.1; women, 9.2 vs 3.1), but impact severity did not significantly differ between events for either sport (men, 21.1g vs 21.3g; women, 14.7g vs 18.1g). The study data suggest a higher impact burden during games compared with practices, but this effect is driven by the quantity rather than severity of impacts. In contrast, sex-based effects in impact burden are driven by average impact severity rather than quantity. Data collected from larger multisite trials and/or different age groups could be used to inform ongoing debates, including headgear and practice regulations, that might appreciably affect the burden of head impacts in lacrosse. While most head impacts do not result in a clinical diagnosis of concussion, evidence indicates that

  17. Kansas: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Kansas Early Head Start (KEHS) provides comprehensive services following federal Head Start Program Performance Standards for pregnant women and eligible families with children from birth to age 4. KEHS was implemented in 1998 using Child Care and Development Block Grant (CCDBG) quality set-aside dollars augmented by a transfer of federal…

  18. 46 CFR 76.23-25 - Sprinkler heads.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

  19. 46 CFR 76.23-25 - Sprinkler heads.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

  20. 46 CFR 76.23-25 - Sprinkler heads.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

  1. 46 CFR 76.23-25 - Sprinkler heads.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

  2. 46 CFR 76.23-25 - Sprinkler heads.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

  3. Head position of helicopter pilots during slalom maneuvers.

    PubMed

    Temme, Leonard A; Still, David L

    2007-01-01

    Pilots typically tilt their heads when executing coordinated banking turns, a phenomenon commonly attributed to the putative opto-kinetic cervical reflex (OKCR). The OKCR is usually described as a reflex, primarily driven by stimuli in the visual periphery, and is important to a pilot's spatial orientation by providing a relatively stabilized horizontal frame of reference. The present paper presents an alternative hypothesis for the observed head tilting seen in pilots. An archived data set, originally collected for other purposes, contained the head turn, pitch, and tilt of 4 helicopter pilots recorded at 10 Hz as the pilots executed 42 slalom maneuvers in an AH Mk 7 Lynx helicopter under visual flight conditions. The analytic method was a correlational analysis of head turn, pitch, and tilt. As expected, pilots routinely tilted their heads during the slaloms in a fashion typically attributed to the OKCR. Correlations among head turn, tilt, and pitch showed that when the helicopter turned left, the head, presumably to look into the turn, turned left and also pitched up and tilted right. Similarly, when the helicopter turned right, the head, presumably to look into the turn, turned right, pitched up, and tilted left. The head tilting usually attributed to a neuromuscular reflex driven by visual stimuli may be a biomechanical consequence of the head posture pilots assume when they simply look where they are going, eliminating the need to postulate the existence of a novel neuromuscular reflex.

  4. Statistical image-domain multimaterial decomposition for dual-energy CT.

    PubMed

    Xue, Yi; Ruan, Ruoshui; Hu, Xiuhua; Kuang, Yu; Wang, Jing; Long, Yong; Niu, Tianye

    2017-03-01

    Dual-energy CT (DECT) enhances tissue characterization because of its basis material decomposition capability. In addition to conventional two-material decomposition from DECT measurements, multimaterial decomposition (MMD) is required in many clinical applications. To solve the ill-posed problem of reconstructing multi-material images from dual-energy measurements, additional constraints are incorporated into the formulation, including volume and mass conservation and the assumptions that there are at most three materials in each pixel and various material types among pixels. The recently proposed flexible image-domain MMD method decomposes pixels sequentially into multiple basis materials using a direct inversion scheme which leads to magnified noise in the material images. In this paper, we propose a statistical image-domain MMD method for DECT to suppress the noise. The proposed method applies penalized weighted least-square (PWLS) reconstruction with a negative log-likelihood term and edge-preserving regularization for each material. The statistical weight is determined by a data-based method accounting for the noise variance of high- and low-energy CT images. We apply the optimization transfer principles to design a serial of pixel-wise separable quadratic surrogates (PWSQS) functions which monotonically decrease the cost function. The separability in each pixel enables the simultaneous update of all pixels. The proposed method is evaluated on a digital phantom, Catphan©600 phantom and three patients (pelvis, head, and thigh). We also implement the direct inversion and low-pass filtration methods for a comparison purpose. Compared with the direct inversion method, the proposed method reduces noise standard deviation (STD) in soft tissue by 95.35% in the digital phantom study, by 88.01% in the Catphan©600 phantom study, by 92.45% in the pelvis patient study, by 60.21% in the head patient study, and by 81.22% in the thigh patient study, respectively. The

  5. Interplay between the spin transfer and spin orbit torques on domain walls at the 5d/3d-alloy interfaces

    NASA Astrophysics Data System (ADS)

    Kalitsov, Alan; Okatov, Sergey; Zarzhitsky, Pavel; Chshiev, Mairbek; Velev, Julian; Butler, William; Mryasov, Oleg

    2014-03-01

    The manipulations of domain wall (DW) in thin ferromagnetic layers by current and the spin-orbit coupling (SOC) have attracted significant interest. We report two band model calculations of the spin torque (ST) and the spin current (SC) at 5d/3d interfaces with head-to-head, Bloch and Neel DWs. These calculations are based on the non-equilibrium Green Function formalism and the tight binding Hamiltonian including the s-d exchange interactions and the Rashba SOC parameterized on the basis of ab-initio calculations for Fe/W, FeCo/Ta and Co/Pt interfaces. We find that SOC significantly modifies the ST and violates relations between the spin transfer torque and the divergence of the spin current. This work was supported in part by a Semiconductor Research Corporation program, sponsored by MARCO and DARPA.

  6. Further Research on Heading in Text

    DTIC Science & Technology

    1989-12-28

    statement headings with low-ability children 10 5.0 Summary of the experiments 11 6.0 Concluding remarks 13 7.0 Acknowledgements 16 8.0 References 17... colour -coded headings as retrieval devices in electronic text, as well as the efficacy of ’running heads’. These, and other implications of research on...The following topics are discussed: * the time spent watching television " the people’s favourite programmes * attitudes to the BBC * attitudes to ITV

  7. Head-to-head randomized trials are mostly industry sponsored and almost always favor the industry sponsor.

    PubMed

    Flacco, Maria Elena; Manzoli, Lamberto; Boccia, Stefania; Capasso, Lorenzo; Aleksovska, Katina; Rosso, Annalisa; Scaioli, Giacomo; De Vito, Corrado; Siliquini, Roberta; Villari, Paolo; Ioannidis, John P A

    2015-07-01

    To map the current status of head-to-head comparative randomized evidence and to assess whether funding may impact on trial design and results. From a 50% random sample of the randomized controlled trials (RCTs) published in journals indexed in PubMed during 2011, we selected the trials with ≥ 100 participants, evaluating the efficacy and safety of drugs, biologics, and medical devices through a head-to-head comparison. We analyzed 319 trials. Overall, 238,386 of the 289,718 randomized subjects (82.3%) were included in the 182 trials funded by companies. Of the 182 industry-sponsored trials, only 23 had two industry sponsors and only three involved truly antagonistic comparisons. Industry-sponsored trials were larger, more commonly registered, used more frequently noninferiority/equivalence designs, had higher citation impact, and were more likely to have "favorable" results (superiority or noninferiority/equivalence for the experimental treatment) than nonindustry-sponsored trials. Industry funding [odds ratio (OR) 2.8; 95% confidence interval (CI): 1.6, 4.7] and noninferiority/equivalence designs (OR 3.2; 95% CI: 1.5, 6.6), but not sample size, were strongly associated with "favorable" findings. Fifty-five of the 57 (96.5%) industry-funded noninferiority/equivalence trials got desirable "favorable" results. The literature of head-to-head RCTs is dominated by the industry. Industry-sponsored comparative assessments systematically yield favorable results for the sponsors, even more so when noninferiority designs are involved. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Coordinates of Human Visual and Inertial Heading Perception.

    PubMed

    Crane, Benjamin Thomas

    2015-01-01

    Heading estimation involves both inertial and visual cues. Inertial motion is sensed by the labyrinth, somatic sensation by the body, and optic flow by the retina. Because the eye and head are mobile these stimuli are sensed relative to different reference frames and it remains unclear if a perception occurs in a common reference frame. Recent neurophysiologic evidence has suggested the reference frames remain separate even at higher levels of processing but has not addressed the resulting perception. Seven human subjects experienced a 2s, 16 cm/s translation and/or a visual stimulus corresponding with this translation. For each condition 72 stimuli (360° in 5° increments) were delivered in random order. After each stimulus the subject identified the perceived heading using a mechanical dial. Some trial blocks included interleaved conditions in which the influence of ±28° of gaze and/or head position were examined. The observations were fit using a two degree-of-freedom population vector decoder (PVD) model which considered the relative sensitivity to lateral motion and coordinate system offset. For visual stimuli gaze shifts caused shifts in perceived head estimates in the direction opposite the gaze shift in all subjects. These perceptual shifts averaged 13 ± 2° for eye only gaze shifts and 17 ± 2° for eye-head gaze shifts. This finding indicates visual headings are biased towards retina coordinates. Similar gaze and head direction shifts prior to inertial headings had no significant influence on heading direction. Thus inertial headings are perceived in body-centered coordinates. Combined visual and inertial stimuli yielded intermediate results.

  9. Coordinates of Human Visual and Inertial Heading Perception

    PubMed Central

    Crane, Benjamin Thomas

    2015-01-01

    Heading estimation involves both inertial and visual cues. Inertial motion is sensed by the labyrinth, somatic sensation by the body, and optic flow by the retina. Because the eye and head are mobile these stimuli are sensed relative to different reference frames and it remains unclear if a perception occurs in a common reference frame. Recent neurophysiologic evidence has suggested the reference frames remain separate even at higher levels of processing but has not addressed the resulting perception. Seven human subjects experienced a 2s, 16 cm/s translation and/or a visual stimulus corresponding with this translation. For each condition 72 stimuli (360° in 5° increments) were delivered in random order. After each stimulus the subject identified the perceived heading using a mechanical dial. Some trial blocks included interleaved conditions in which the influence of ±28° of gaze and/or head position were examined. The observations were fit using a two degree-of-freedom population vector decoder (PVD) model which considered the relative sensitivity to lateral motion and coordinate system offset. For visual stimuli gaze shifts caused shifts in perceived head estimates in the direction opposite the gaze shift in all subjects. These perceptual shifts averaged 13 ± 2° for eye only gaze shifts and 17 ± 2° for eye-head gaze shifts. This finding indicates visual headings are biased towards retina coordinates. Similar gaze and head direction shifts prior to inertial headings had no significant influence on heading direction. Thus inertial headings are perceived in body-centered coordinates. Combined visual and inertial stimuli yielded intermediate results. PMID:26267865

  10. Femoral head asymmetry and coxa magna: anatomic study.

    PubMed

    Young, Ernest Y; Gebhart, Jeremy J; Bajwa, Navkirat; Cooperman, Daniel R; Ahn, Nicholas U

    2014-06-01

    Coxa magna, the asymmetrical circumferential enlargement of the femoral head, is an important sequela of pediatric disorders such as Legg-Calvé-Perthes disease. Definitions vary because of lack of controls and a scarcity of research on the distribution of the femoral head asymmetry. This study aims at defining the normal distribution of asymmetry between the left and the right femoral head and neck in the population and how demographics affect these properties. The study also looked at the distribution of side dominance (left or right). This study measured 230 paired femurs from individuals (20 to 40 y old) distributed for sex and ethnicity. The height and weight of the individuals were also recorded. The femoral head diameter and minimal femoral neck diameter in the anteroposterior view were measured on each paired femurs. The absolute and percent differences were determined to define asymmetry. Most of the population fell within 3% of asymmetry for the femoral head and 4% for the femoral neck. The maximum head percent asymmetry was 7.4%. Absolute difference in millimeters to percent asymmetry showed a ratio of 2:1 for the femoral head and 3:1 for the femoral neck. African Americans showed greater femoral head symmetry and a bias toward left-sided femoral head and neck enlargement when compared with their white counterparts. There was a high degree of symmetry between the left and right femoral heads and necks, which supports definitions found in the literature that define coxa magna above 10%. This study defines asymmetry in the femoral head in the normal population, which will help to define a quantitative definition of coxa magna.

  11. Separated matter and antimatter domains with vanishing domain walls

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dolgov, A.D.; Godunov, S.I.; Rudenko, A.S.

    2015-10-01

    We present a model of spontaneous (or dynamical) C and CP violation where it is possible to generate domains of matter and antimatter separated by cosmologically large distances. Such C(CP) violation existed only in the early universe and later it disappeared with the only trace of generated baryonic and/or antibaryonic domains. So the problem of domain walls in this model does not exist. These features are achieved through a postulated form of interaction between inflaton and a new scalar field, realizing short time C(CP) violation.

  12. Head flexion angle while using a smartphone.

    PubMed

    Lee, Sojeong; Kang, Hwayeong; Shin, Gwanseob

    2015-01-01

    Repetitive or prolonged head flexion posture while using a smartphone is known as one of risk factors for pain symptoms in the neck. To quantitatively assess the amount and range of head flexion of smartphone users, head forward flexion angle was measured from 18 participants when they were conducing three common smartphone tasks (text messaging, web browsing, video watching) while sitting and standing in a laboratory setting. It was found that participants maintained head flexion of 33-45° (50th percentile angle) from vertical when using the smartphone. The head flexion angle was significantly larger (p < 0.05) for text messaging than for the other tasks, and significantly larger while sitting than while standing. Study results suggest that text messaging, which is one of the most frequently used app categories of smartphone, could be a main contributing factor to the occurrence of neck pain of heavy smartphone users. Practitioner Summary: In this laboratory study, the severity of head flexion of smartphone users was quantitatively evaluated when conducting text messaging, web browsing and video watching while sitting and standing. Study results indicate that text messaging while sitting caused the largest head flexion than that of other task conditions.

  13. Uterine molecular changes for non-invasive embryonic attachment in the marsupials Macropus eugenii (Macropodidae) and Trichosurus vulpecula (Phalangeridae).

    PubMed

    Laird, Melanie K; Dargan, Jessica R; Paterson, Lillian; Murphy, Christopher R; McAllan, Bronwyn M; Shaw, Geoff; Renfree, Marilyn B; Thompson, Michael B

    2017-10-01

    Pregnancy in mammals requires remodeling of the uterus to become receptive to the implanting embryo. Remarkably similar morphological changes to the uterine epithelium occur in both eutherian and marsupial mammals, irrespective of placental type. Nevertheless, molecular differences in uterine remodeling indicate that the marsupial uterus employs maternal defences, including molecular reinforcement of the uterine epithelium, to regulate embryonic invasion. Non-invasive (epitheliochorial) embryonic attachment in marsupials likely evolved secondarily from invasive attachment, so uterine defences in these species may prevent embryonic invasion. We tested this hypothesis by identifying localization patterns of Talin, a key basal anchoring molecule, in the uterine epithelium during pregnancy in the tammar wallaby (Macropus eugenii; Macropodidae) and the brush tail possum (Trichosurus vulpecula; Phalangeridae). Embryonic attachment is non-invasive in both species, yet Talin undergoes a clear distributional change during pregnancy in M. eugenii, including recruitment to the base of the uterine epithelium just before attachment, that closely resembles that of invasive implantation in the marsupial species Sminthopsis crassicaudata. Basal localization occurs throughout pregnancy in T. vulpecula, although, as for M. eugenii, this pattern is most specific prior to attachment. Such molecular reinforcement of the uterine epithelium for non-invasive embryonic attachment in marsupials supports the hypothesis that less-invasive and non-invasive embryonic attachment in marsupials may have evolved via accrual of maternal defences. Recruitment of basal molecules, including Talin, to the uterine epithelium may have played a key role in this transition. © 2017 Wiley Periodicals, Inc.

  14. 49 CFR 179.200-8 - Tank heads.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Tank heads. 179.200-8 Section 179.200-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-8 Tank heads. (a) All external tank heads...

  15. 49 CFR 179.100-8 - Tank heads.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Tank heads. 179.100-8 Section 179.100-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-8 Tank heads. (a) The tank head shape...

  16. 49 CFR 179.200-8 - Tank heads.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Tank heads. 179.200-8 Section 179.200-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-8 Tank heads. (a) All external tank heads...

  17. Head-Impact–Measurement Devices: A Systematic Review

    PubMed Central

    O'Connor, Kathryn L.; Rowson, Steven; Duma, Stefan M.; Broglio, Steven P.

    2017-01-01

    Context: With an estimated 3.8 million sport- and recreation-related concussions occurring annually, targeted prevention and diagnostic methods are needed. Biomechanical analysis of head impacts may provide quantitative information that can inform both prevention and diagnostic strategies. Objective: To assess available head-impact devices and their clinical utility. Data Sources: We performed a systematic search of the electronic database PubMed for peer-reviewed publications, using the following phrases: accelerometer and concussion, head impact telemetry, head impacts and concussion and sensor, head impacts and sensor, impact sensor and concussion, linear acceleration and concussion, rotational acceleration and concussion, and xpatch concussion. In addition to the literature review, a Google search for head impact monitor and concussion monitor yielded 15 more devices. Study Selection: Included studies were performed in vivo, used commercially available devices, and focused on sport-related concussion. Data Extraction: One author reviewed the title and abstract of each study for inclusion and exclusion criteria and then reviewed each full-text article to confirm inclusion criteria. Controversial articles were reviewed by all authors to reach consensus. Data Synthesis: In total, 61 peer-reviewed articles involving 4 head-impact devices were included. Participants in boxing, football, ice hockey, soccer, or snow sports ranged in age from 6 to 24 years; 18% (n = 11) of the studies included female athletes. The Head Impact Telemetry System was the most widely used device (n = 53). Fourteen additional commercially available devices were presented. Conclusions: Measurements collected by impact monitors provided real-time data to estimate player exposure but did not have the requisite sensitivity to concussion. Proper interpretation of previously reported head-impact kinematics across age, sport, and position may inform future research and enable staff clinicians

  18. Kinematics of a Head-Neck Model Simulating Whiplash

    ERIC Educational Resources Information Center

    Colicchia, Giuseppe; Zollman, Dean; Wiesner, Hartmut; Sen, Ahmet Ilhan

    2008-01-01

    A whiplash event is a relative motion between the head and torso that occurs in rear-end automobile collisions. In particular, the large inertia of the head results in a horizontal translation relative to the thorax. This paper describes a simulation of the motion of the head and neck during a rear-end (whiplash) collision. A head-neck model that…

  19. Nebraska: Early Head Start Initiative

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Since 1999, Nebraska's Early Head Start Infant/Toddler Quality Initiative has supported Early Head Start (EHS) and community child care partnerships to improve the quality and professionalism of infant and toddler care. EHS programs apply to receive funding to establish partnerships with center-based or home-based child care.The initiative has…

  20. Vision Screening For Head Starters.

    ERIC Educational Resources Information Center

    Foley, Celia

    To determine which children in the Head Start program may have vision problems, Head Start teachers and staff do vision "screening." This booklet demonstrates how to do the screening using the Snellen "E Chart." Trouble signs that the test administrator should be aware of are listed, and vision scores are explained simply.…

  1. The Effects of Head Start Health Services: Executive Summary of the Head Start Health Evaluation.

    ERIC Educational Resources Information Center

    Fosburg, Linda B.; And Others

    This report summarizes findings of an evaluation of Head Start health services. Chapter one presents an overview of the background of the evaluation project. Chapter two highlights findings for the major evaluation questions. These questions focus specifically on children's health status prior to entry into Head Start, health services subsequently…

  2. 49 CFR 179.220-8 - Tank heads.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Tank heads. 179.220-8 Section 179.220-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-8 Tank heads. (a) Tank heads of the inner...

  3. 49 CFR 179.220-8 - Tank heads.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Tank heads. 179.220-8 Section 179.220-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-8 Tank heads. (a) Tank heads of the inner...

  4. Head Start of North Dakota, 1999-2000.

    ERIC Educational Resources Information Center

    North Dakota Dept. of Human Services, Bismark. Div. of Children and Family Services.

    The Head Start program, a comprehensive child development program designed to increase the social competence of children in low-income families and children with disabilities and to improve their chances of school success, has been in North Dakota since 1965. This report describes the objectives of the Head Start and Early Head Start programs, the…

  5. Internationalized Domain Names.

    ERIC Educational Resources Information Center

    Wielansky, Marc D.

    2002-01-01

    Reports on an investigation of what may appear at first to be an arcane topic--the internationalization of domain names on the Internet. Concludes that expanding domain names internationally poses challenges to the inherent open structure of the Internet; to its ease of use for those accustomed to Latin-alphabet-only domain names; and to corporate…

  6. Engineering of head-mounted projective displays.

    PubMed

    Hua, H; Girardot, A; Gao, C; Rolland, J P

    2000-08-01

    Head-mounted projective displays (HMPD's) are a novel type of head-mounted display. A HMPD consists of a miniature projection lens mounted upon the user's head and retroreflective sheeting material placed strategically in the environment. First, the imaging concept of a HMPD is reviewed and its potential advantages and disadvantages are discussed. The design and a bench prototype implementation are then presented. Finally, the effects of retroreflective materials on the imaging properties and the optical properties of HMPD's are comprehensively investigated.

  7. Head stabilisation in fast running lizards.

    PubMed

    Goyens, Jana; Aerts, Peter

    2018-04-01

    The cyclic patterns of terrestrial animal locomotion are frequently perturbed in natural environments. The terrain can be complex or inclined, the substrate can move unexpectedly and animals can misjudge situations. Loosing stability due to perturbations increases the probability of capture by predators and decreases the chance of successful prey capture and winning intraspecific battles. When controlled corrective actions are necessary to negotiate perturbations, animals rely on their exteroceptive and proprioceptive senses to monitor the environment and their own body movements. The vestibular system in the inner ear perceives linear and angular accelerations. This information enables gaze stabilisation and the creation of a stable, world-bound reference frame for the integration of the information of other senses. During locomotion, both functions are known to be facilitated by head stabilisation in several animals with an erect posture. Animals with a sprawled body posture, however, undergo very large body undulations while running. Using high speed video recordings, we tested whether they nevertheless stabilise their head during running, and how this is influenced by perturbations. We found that running Acanthodactylus boskianus lizards strongly stabilise their head yaw rotations when running on a flat, straight runway: the head rotation amplitude is only 4.76±0.99°, while the adjacent trunk part rotates over 27.0±3.8°. Lateral head translations are not stabilised (average amplitude of 7.4±2.0mm). When the lizards are experimentally perturbed by a large and unexpected lateral substrate movement, lateral translations of both the head and the body decrease (on average by 1.52±0.81mm). At the same time, the rotations of the head and trunk also decrease (on average by 1.62°±7.21°). These results show that head stabilisation intensifies because of the perturbation, which emphasises the importance of vestibular perception and balance in these fast and

  8. Does the hair influence heat extraction from the head during head cooling under heat stress?

    PubMed Central

    SHIN, Sora; PARK, Joonhee; LEE, Joo-Young

    2015-01-01

    The purpose of this study was to investigate the effects of head hair on thermoregulatory responses when cooling the head under heat stress. Eight young males participated in six experimental conditions: normal hair (100–130 mm length) and cropped hair (5 mm length) with three water inlet temperatures of 10, 15, and 20°C. The head and neck of subjects were cooled by a liquid perfused hood while immersing legs at 42°C water for 60 min in a sitting position at the air temperature of 28°C with 30% RH. The results showed that heat removal from the normal hair condition was not significantly different from the cropped hair condition. Rectal and mean skin temperatures, and sweat rate showed no significant differences between the normal and cropped hair conditions. Heat extraction from the head was significantly greater in 10°C than in 15 or 20°C cooling (p<0.05) for both normal and cropped hair, whereas subjects preferred the 15°C more than the 10 or 20°C cooling regimen. These results indicate that the selection of effective cooling temperature is more crucial than the length of workers’ hair during head cooling under heat stress, and such selection should be under the consideration of subjective perceptions with physiological responses. PMID:26165361

  9. Non-Linear Harmonic flow simulations of a High-Head Francis Turbine test case

    NASA Astrophysics Data System (ADS)

    Lestriez, R.; Amet, E.; Tartinville, B.; Hirsch, C.

    2016-11-01

    This work investigates the use of the non-linear harmonic (NLH) method for a high- head Francis turbine, the Francis99 workshop test case. The NLH method relies on a Fourier decomposition of the unsteady flow components in harmonics of Blade Passing Frequencies (BPF), which are the fundamentals of the periodic disturbances generated by the adjacent blade rows. The unsteady flow solution is obtained by marching in pseudo-time to a steady-state solution of the transport equations associated with the time-mean, the BPFs and their harmonics. Thanks to this transposition into frequency domain, meshing only one blade channel is sufficient, like for a steady flow simulation. Notable benefits in terms of computing costs and engineering time can therefore be obtained compared to classical time marching approach using sliding grid techniques. The method has been applied for three operating points of the Francis99 workshop high-head Francis turbine. Steady and NLH flow simulations have been carried out for these configurations. Impact of the grid size and near-wall refinement is analysed on all operating points for steady simulations and for Best Efficiency Point (BEP) for NLH simulations. Then, NLH results for a selected grid size are compared for the three different operating points, reproducing the tendencies observed in the experiment.

  10. Comparison of frequency-domain and time-domain rotorcraft vibration control methods

    NASA Technical Reports Server (NTRS)

    Gupta, N. K.

    1984-01-01

    Active control of rotor-induced vibration in rotorcraft has received significant attention recently. Two classes of techniques have been proposed. The more developed approach works with harmonic analysis of measured time histories and is called the frequency-domain approach. The more recent approach computes the control input directly using the measured time history data and is called the time-domain approach. The report summarizes the results of a theoretical investigation to compare the two approaches. Five specific areas were addressed: (1) techniques to derive models needed for control design (system identification methods), (2) robustness with respect to errors, (3) transient response, (4) susceptibility to noise, and (5) implementation difficulties. The system identification methods are more difficult for the time-domain models. The time-domain approach is more robust (e.g., has higher gain and phase margins) than the frequency-domain approach. It might thus be possible to avoid doing real-time system identification in the time-domain approach by storing models at a number of flight conditions. The most significant error source is the variation in open-loop vibrations caused by pilot inputs, maneuvers or gusts. The implementation requirements are similar except that the time-domain approach can be much simpler to implement if real-time system identification were not necessary.

  11. Head Lice

    MedlinePlus

    ... the-counter shampoos and lotions containing pyrethrin (one brand name: Rid) or permethrin (brand name: Nix) are commonly used to treat head ... hand or by using a special comb (one brand name: LiceMeister comb) to remove them. Comb through ...

  12. Heads Up to High School Sports

    MedlinePlus

    ... submit" value="Submit" /> HEADS UP to School Sports Recommend on Facebook Tweet Share Compartir To help ... organizations, developed the HEADS UP: Concussion in School Sports initiative and materials. Specific Concussion Information for... Coaches ...

  13. Interview with Joe F. Head

    ERIC Educational Resources Information Center

    West, Kim

    2008-01-01

    This article presents an interview with Joe F. Head, Dean of University Admissions and Enrollment Services at Kennesaw State University (KSU) in Georgia, who has more than 35 years of experience in admissions and enrollment services. After completing an M.Ed. in higher education at Georgia Southern University, Head immediately landed a position as…

  14. The Start of Head Start

    ERIC Educational Resources Information Center

    Neugebauer, Roger

    2010-01-01

    The creation of the Head Start program occurred at break-neck speed with many dramatic turns and many colorful players. No one tells the story better than Edward Zigler in "Head Start: The Inside Story of America's Most Successful Educational Experiment"--a detailed and personal, behind the scenes look at the program's inception. From this…

  15. Interfacial Partitioning of a Loop Hinge Residue Contributes to Diacylglycerol Affinity of Conserved Region 1 Domains*

    PubMed Central

    Stewart, Mikaela D.; Cole, Taylor R.; Igumenova, Tatyana I.

    2014-01-01

    Conventional and novel isoenzymes of PKC are activated by the membrane-embedded second messenger diacylglycerol (DAG) through its interactions with the C1 regulatory domain. The affinity of C1 domains to DAG varies considerably among PKCs. To gain insight into the origin of differential DAG affinities, we conducted high-resolution NMR studies of C1B domain from PKCδ (C1Bδ) and its W252Y variant. The W252Y mutation was previously shown to render C1Bδ less responsive to DAG (Dries, D. R., Gallegos, L. L., and Newton, A. C. (2007) A single residue in the C1 domain sensitizes novel protein kinase C isoforms to cellular diacylglycerol production. J. Biol. Chem. 282, 826–830) and thereby emulate the behavior of C1B domains from conventional PKCs that have a conserved Tyr at the equivalent position. Our data revealed that W252Y mutation did not perturb the conformation of C1Bδ in solution but significantly reduced its propensity to partition into a membrane-mimicking environment in the absence of DAG. Using detergent micelles doped with a paramagnetic lipid, we determined that both the residue identity at position 252 and complexation with diacylglycerol influence the geometry of C1Bδ-micelle interactions. In addition, we identified the C-terminal helix α1 of C1Bδ as an interaction site with the head groups of phosphatidylserine, a known activator of PKCδ. Taken together, our studies (i) reveal the identities of C1Bδ residues involved in interactions with membrane-mimicking environment, DAG, and phosphatidylserine, as well as the affinities associated with each event and (ii) suggest that the initial ligand-independent membrane recruitment of C1B domains, which is greatly facilitated by the interfacial partitioning of Trp-252, is responsible, at least in part, for the differential DAG affinities. PMID:25124034

  16. Health Coordination Manual. Head Start Health Services.

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

    Part 1 of this manual on coordinating health care services for Head Start children provides an overview of what Head Start health staff should do to meet the medical, mental health, nutritional, and/or dental needs of Head Start children, staff, and family members. Offering examples, lists, action steps, and charts for clarification, part 2…

  17. Can imaginary head tilt shorten postrotatory nystagmus?

    PubMed

    Gianna-Poulin, C C; Voelker, C C; Erickson, B; Black, F O

    2001-08-01

    In healthy subjects, head tilt upon cessation of a constant-velocity yaw head rotation shortens the duration of postrotatory nystagmus. The presumed mechanism for this effect is that the velocity storage of horizontal semicircular canal inputs is being discharged by otolith organ inputs which signal a constant yaw head position when the head longitudinal axis is no longer earth-vertical. In the present study, normal subjects were rotated head upright in the dark on a vertical-axis rotational chair at 60 degrees/s for 75 s and were required to perform a specific task as soon as the chair stopped. Horizontal position of the right eye was recorded with an infra-red video camera. The average eye velocity (AEV) was measured over a 30-s interval following chair acceleration/deceleration. The ratios (postrotatory AEV/perrotatory AEV) were 1.1 (SD 0.112) when subjects (N=10) kept their head erect, 0.414 (SD 0.083) when subjects tilted their head forward, 1.003 (SD 0.108) when subjects imagined watching a TV show, 1.012 (SD 0.074) when subjects imagined looking at a painting on a wall, and 0.995 (SD 0.074) when subjects imagined floating in a prone position on a lake. Thus, while actual head tilt reduced postrotatory nystagmus, the imagination tasks did not have a statistically significant effect on postrotatory nystagmus. Therefore, velocity storage does not appear to be under the influence of cortical neural signals when subjects imagine that they are floating in a prone orientation.

  18. Measurement of flow inside a vacuum cleaner head

    NASA Astrophysics Data System (ADS)

    Iguchi, Ryotaro; Ban, Hisataka; Sakakibara, Jun

    2017-11-01

    Vacuum cleaner head with rotating brushes is widely used as a home appliance. Although it efficiently collects dusts from the floor, flow field of the air and motion of the dust inside the head have not been fully investigated. In this study, we performed 3D-PIV (particle tracking velocimetry) measurement of velocity field inside the head. Water was used as working fluid, which allows a use of fluorescent particle to reduce unwanted reflection from the brushes and inner surface of the head. Mean velocity field and turbulence statistics in the head with and without the brush will be presented.

  19. [Head injuries in the Bible].

    PubMed

    Feinsod, M

    1995-12-15

    3 cases of head injury are described in the Bible: the death of Sisera by the hand of Jael (Judges 4: 21; 5: 25); the skull fractures of Avimelech incurred at the tower of Tevetz, (Judges, 9: 53, 54); and the slaying of Goliath by David, (Samuel I 17: 49-51). The various attempts to understand the mechanisms of these head injuries using philology, knowledge of the art of biblical warfare and modern medical considerations are reviewed. We try to identify the site of the mortal blow to Sisera's head, to understand why Avimelech asked to be killed, and to decide whether the giant from Gath was a rugged warrior or just an endocrinological cripple.

  20. 49 CFR 572.83 - Head-neck.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 9-Month Old Child § 572.83 Head-neck. The head-neck assembly shown in drawing 1049/A consists of parts specified as items 1 through 16 and...