Littérature scientifique sur le sujet « Hook domain »
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Articles de revues sur le sujet "Hook domain"
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Xu, Lai, Mathew E. Sowa, Jing Chen, Xue Li, Steven P. Gygi et J. Wade Harper. « An FTS/Hook/p107FHIP Complex Interacts with and Promotes Endosomal Clustering by the Homotypic Vacuolar Protein Sorting Complex ». Molecular Biology of the Cell 19, no 12 (décembre 2008) : 5059–71. http://dx.doi.org/10.1091/mbc.e08-05-0473.
Texte intégralRésumé :
Fused Toes (FTS) is a member of a small group of inactive variant E2 ubiquitin-conjugating enzyme domain-containing proteins of unknown function. Through proteomic analysis of FTS complexes purified from human embryonic kidney 293T cells, we identified a new multiprotein complex, the FHF complex, containing FTS, members of the microtubule-binding Hook family of coiled-coil proteins (Hook1, Hook2, and Hook3), and a previously uncharacterized 107-kDa protein, FTS and Hook Interacting Protein (FHIP). FTS associated with a conserved C-terminal motif in Hook proteins in the yeast two-hybrid system and in tissue culture cells, and Hook proteins were found to form homo- and heterodimers. The ∼500-kDa FHF complex contained all three Hook proteins, and small interfering RNA depletion experiments suggest that Hook proteins can interact interchangeably within this complex. Hook proteins as well as FTS interact with members of both the class B and class C components of the homotypic vesicular protein sorting (HOPS) complex. Depletion of FTS by RNA interference affects both the trafficking of epidermal growth factor from early-to-late endosome/lysosomes and the efficiency by which overexpression of the HOPS component Vps18 promotes clustering of lysosomal-associated membrane protein 1-positive endosome/lysosomes. These data suggest that the FTS/Hook/FHIP complex functions to promote vesicle trafficking and/or fusion via the HOPS complex.
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Schroeder, Courtney M., et Ronald D. Vale. « Assembly and activation of dynein–dynactin by the cargo adaptor protein Hook3 ». Journal of Cell Biology 214, no 3 (1 août 2016) : 309–18. http://dx.doi.org/10.1083/jcb.201604002.
Texte intégralRésumé :
Metazoan cytoplasmic dynein moves processively along microtubules with the aid of dynactin and an adaptor protein that joins dynein and dynactin into a stable ternary complex. Here, we examined how Hook3, a cargo adaptor involved in Golgi and endosome transport, forms a motile dynein–dynactin complex. We show that the conserved Hook domain interacts directly with the dynein light intermediate chain 1 (LIC1). By solving the crystal structure of the Hook domain and using structure-based mutagenesis, we identify two conserved surface residues that are each critical for LIC1 binding. Hook proteins with mutations in these residues fail to form a stable dynein–dynactin complex, revealing a crucial role for LIC1 in this interaction. We also identify a region of Hook3 specifically required for an allosteric activation of processive motility. Our work reveals the structural details of Hook3’s interaction with dynein and offers insight into how cargo adaptors form processive dynein–dynactin motor complexes.
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Zhang, Jun, Rongde Qiu, Herbert N. Arst, Miguel A. Peñalva et Xin Xiang. « HookA is a novel dynein–early endosome linker critical for cargo movement in vivo ». Journal of Cell Biology 204, no 6 (17 mars 2014) : 1009–26. http://dx.doi.org/10.1083/jcb.201308009.
Texte intégralRésumé :
Cytoplasmic dynein transports membranous cargoes along microtubules, but the mechanism of dynein–cargo interaction is unclear. From a genetic screen, we identified a homologue of human Hook proteins, HookA, as a factor required for dynein-mediated early endosome movement in the filamentous fungus Aspergillus nidulans. HookA contains a putative N-terminal microtubule-binding domain followed by coiled-coil domains and a C-terminal cargo-binding domain, an organization reminiscent of cytoplasmic linker proteins. HookA–early endosome interaction occurs independently of dynein–early endosome interaction and requires the C-terminal domain. Importantly, HookA interacts with dynein and dynactin independently of HookA–early endosome interaction but dependent on the N-terminal part of HookA. Both dynein and the p25 subunit of dynactin are required for the interaction between HookA and dynein–dynactin, and loss of HookA significantly weakens dynein–early endosome interaction, causing a virtually complete absence of early endosome movement. Thus, HookA is a novel linker important for dynein–early endosome interaction in vivo.
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Park, Cheon-Gyu, Yongsoo Park et Byung-Chang Suh. « The HOOK region of voltage-gated Ca2+ channel β subunits senses and transmits PIP2 signals to the gate ». Journal of General Physiology 149, no 2 (13 janvier 2017) : 261–76. http://dx.doi.org/10.1085/jgp.201611677.
Texte intégralRésumé :
The β subunit of voltage-gated Ca2+ (CaV) channels plays an important role in regulating gating of the α1 pore-forming subunit and its regulation by phosphatidylinositol 4,5-bisphosphate (PIP2). Subcellular localization of the CaV β subunit is critical for this effect; N-terminal–dependent membrane targeting of the β subunit slows inactivation and decreases PIP2 sensitivity. Here, we provide evidence that the HOOK region of the β subunit plays an important role in the regulation of CaV biophysics. Based on amino acid composition, we broadly divide the HOOK region into three domains: S (polyserine), A (polyacidic), and B (polybasic). We show that a β subunit containing only its A domain in the HOOK region increases inactivation kinetics and channel inhibition by PIP2 depletion, whereas a β subunit with only a B domain decreases these responses. When both the A and B domains are deleted, or when the entire HOOK region is deleted, the responses are elevated. Using a peptide-to-liposome binding assay and confocal microscopy, we find that the B domain of the HOOK region directly interacts with anionic phospholipids via polybasic and two hydrophobic Phe residues. The β2c-short subunit, which lacks an A domain and contains fewer basic amino acids and no Phe residues in the B domain, neither associates with phospholipids nor affects channel gating dynamically. Together, our data suggest that the flexible HOOK region of the β subunit acts as an important regulator of CaV channel gating via dynamic electrostatic and hydrophobic interaction with the plasma membrane.
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Shen, Yuanying, Chongwen Yu et Jianping Yang. « A study on fiber motion in the drafting zone and hook removal ». Textile Research Journal 90, no 11-12 (22 novembre 2019) : 1277–90. http://dx.doi.org/10.1177/0040517519889557.
Texte intégralRésumé :
In this study, the hook removal of four types of hooks during the drafting process has been investigated, and the theory of fiber straightening was further improved by analyzing the relationship between fiber length, fiber straightness, draft ratio, and the fiber accelerated point. Simultaneously, a time domain model was used to simulate the dynamic drafting process based on the straightening analysis, which provided an approach to capture the dynamic motion of different types of fibers and hook removal in the drafting zone. The model is validated by a previous study and experimental work, with the result that the output fiber straightness is both in a good agreement with those calculated by classical theories and experimental data. The straightening effect of the drafting process on four types of hooks under the same drafting conditions is compared. It is shown that the drafting effect on different types of hooked fibers is varied, with the clumped fiber removed preferentially followed by both end hooks or the trailing hook, whereas the leading hook is the most difficult to remove.
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Horváth, Péter, Takayuki Kato, Tomoko Miyata et Keiichi Namba. « Structure of Salmonella Flagellar Hook Reveals Intermolecular Domain Interactions for the Universal Joint Function ». Biomolecules 9, no 9 (9 septembre 2019) : 462. http://dx.doi.org/10.3390/biom9090462.
Texte intégralRésumé :
The bacterial flagellum is a motility organelle consisting of a rotary motor and a long helical filament as a propeller. The flagellar hook is a flexible universal joint that transmits motor torque to the filament in its various orientations that change dynamically between swimming and tumbling of the cell upon switching the motor rotation for chemotaxis. Although the structures of the hook and hook protein FlgE from different bacterial species have been studied, the structure of Salmonella hook, which has been studied most over the years, has not been solved at a high enough resolution to allow building an atomic model of entire FlgE for understanding the mechanisms of self-assembly, stability and the universal joint function. Here we report the structure of Salmonella polyhook at 4.1 Å resolution by electron cryomicroscopy and helical image analysis. The density map clearly revealed folding of the entire FlgE chain forming the three domains D0, D1 and D2 and allowed us to build an atomic model. The model includes domain Dc with a long β-hairpin structure that connects domains D0 and D1 and contributes to the structural stability of the hook while allowing the flexible bending of the hook as a molecular universal joint.
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Cayuela, María L., Montserrat Elías-Arnanz, Marcos Peñalver-Mellado, S. Padmanabhan et Francisco J. Murillo. « The Stigmatella aurantiaca Homolog of Myxococcus xanthus High-Mobility-Group A-Type Transcription Factor CarD : Insights into the Functional Modules of CarD and Their Distribution in Bacteria ». Journal of Bacteriology 185, no 12 (15 juin 2003) : 3527–37. http://dx.doi.org/10.1128/jb.185.12.3527-3537.2003.
Texte intégralRésumé :
ABSTRACT Transcriptional factor CarD is the only reported prokaryotic analog of eukaryotic high-mobility-group A (HMGA) proteins, in that it has contiguous acidic and AT hook DNA-binding segments and multifunctional roles in Myxococcus xanthus carotenogenesis and fruiting body formation. HMGA proteins are small, randomly structured, nonhistone, nuclear architectural factors that remodel DNA and chromatin structure. Here we report on a second AT hook protein, CarDSa, that is very similar to CarD and that occurs in the bacterium Stigmatella aurantiaca. CarDSa has a C-terminal HMGA-like domain with three AT hooks and a highly acidic adjacent region with one predicted casein kinase II (CKII) phosphorylation site, compared to the four AT hooks and five CKII sites in CarD. Both proteins have a nearly identical 180-residue N-terminal segment that is absent in HMGA proteins. In vitro, CarDSa exhibits the specific minor-groove binding to appropriately spaced AT-rich DNA that is characteristic of CarD or HMGA proteins, and it is also phosphorylated by CKII. In vivo, CarDSa or a variant without the single CKII phosphorylation site can replace CarD in M. xanthus carotenogenesis and fruiting body formation. These two cellular processes absolutely require that the highly conserved N-terminal domain be present. Thus, three AT hooks are sufficient, the N-terminal domain is essential, and phosphorylation in the acidic region by a CKII-type kinase can be dispensed with for CarD function in M. xanthus carotenogenesis and fruiting body development. Whereas a number of hypothetical proteins homologous to the N-terminal region occur in a diverse array of bacterial species, eukaryotic HMGA-type domains appear to be confined primarily to myxobacteria.
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Krämer, H., et M. Phistry. « Mutations in the Drosophila hook gene inhibit endocytosis of the boss transmembrane ligand into multivesicular bodies. » Journal of Cell Biology 133, no 6 (15 juin 1996) : 1205–15. http://dx.doi.org/10.1083/jcb.133.6.1205.
Texte intégralRésumé :
Transmembrane ligands can be internalized across cell boundaries into receptor-expressing cells. In the developing Drosophila eye imaginal disc, the bride of sevenless transmembrane protein (boss) is expressed on the surface of R8 cells. After internalization into neighboring R7 cells, the boss protein accumulates in multivesicular bodies. In a search for genes that affect this cell-type-specific pattern of boss endocytosis, we found that mutations in the hook gene inhibit the accumulation of boss in multivesicular bodies of R7 cells. In addition, hook flies exhibit pleiotropic phenotypes including abnormal bristle morphology and eye degeneration. The wild-type-pattern of boss endocytosis was restored in hook mutants by a genomic rescue fragment containing the hook gene or by a hook cDNA expressed in R7 cells under control of a sevenless (sev) enhancer. The hook gene encodes a novel cytoplasmic protein of 679 amino acids with a central coiled-coil domain of some 200 amino acids. Truncated, epitope-tagged hook proteins coimmunoprecipitated the full-length protein, indicating dimerization mediated by the coiled-coil domain. The hook protein localizes to vesicular structures that are part of the endocytic compartment. The requirement of the hook protein in R7 cells for the accumulation of boss protein in multivesicular bodies, and the localization of the hook protein to endocytic vesicles indicate that the hook gene encodes a novel component of the endocytic compartment that plays an important role in the endocytosis of transmembrane ligands or their transport to multivesicular bodies.
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Ciampi, Raffaele, Thomas J. Giordano, Kathryn Wikenheiser-Brokamp, Ronald J. Koenig et Yuri E. Nikiforov. « HOOK3-RET : a novel type of RET/PTC rearrangement in papillary thyroid carcinoma ». Endocrine-Related Cancer 14, no 2 (juin 2007) : 445–52. http://dx.doi.org/10.1677/erc-07-0039.
Texte intégralRésumé :
Chromosomal rearrangements of the RET proto-oncogene (RET/PTC) are the common feature of papillary thyroid carcinoma (PTC). In this study, we report the identification, cloning, and functional characterization of a novel type of RET/PTC rearrangement that results from the fusion of the 3′-portion of RET coding for the tyrosine kinase (TK) domain of the receptor to the 5′-portion of the Homo sapiens hook homolog 3 (HOOK3) gene. The novel fusion was identified in a case of PTC that revealed a gene expression signature characteristic of RET/PTC on DNA microarray analysis, but was negative for the most common types of RET rearrangement. A fusion product between exon 11 of HOOK3 and exon 12 of RET gene was identified by 5′RACE, and the presence of chimeric HOOK3-RET protein of 88 kDa was detected by western blot analysis with an anti-RET antibody. The protein is predicted to contain a portion of the coiled-coil domains of HOOK3 and the intact TK domain of RET. Expression of the HOOK3-RET cDNA in NIH3T3 cells resulted in the formation of transformed foci and in tumor formation after injection into nude mice, confirming the oncogenic nature of HOOK3-RET.
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Laumer, I. B., T. Bugnyar, S. A. Reber et A. M. I. Auersperg. « Can hook-bending be let off the hook ? Bending/unbending of pliant tools by cockatoos ». Proceedings of the Royal Society B : Biological Sciences 284, no 1862 (6 septembre 2017) : 20171026. http://dx.doi.org/10.1098/rspb.2017.1026.
Texte intégralRésumé :
The spontaneous crafting of hook-tools from bendable material to lift a basket out of a vertical tube in corvids has widely been used as one of the prime examples of animal tool innovation. However, it was recently suggested that the animals' solution was hardly innovative but strongly influenced by predispositions from habitual tool use and nest building. We tested Goffin's cockatoo, which is neither a specialized tool user nor a nest builder, on a similar task set-up. Three birds individually learned to bend hook tools from straight wire to retrieve food from vertical tubes and four subjects unbent wire to retrieve food from horizontal tubes. Pre-experience with ready-made hooks had some effect but was not necessary for success. Our results indicate that the ability to represent and manufacture tools according to a current need does not require genetically hardwired behavioural routines, but can indeed arise innovatively from domain general cognitive processing.
Thèses sur le sujet "Hook domain"
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RENNA, CRISTINA. « BIOCHEMICAL INSIGHTS INTO THE PROTEIN NUMA AND ITS BINDING PARTNERS BETWEEN MITOTIC SPINDLE AND NUCLEAR COMPARTMENTS ». Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/884397.
Texte intégralRésumé :
During my PhD program I worked on two Nuclear Mitotic Apparatus (NuMA)-related projects. The first one centred on the biochemical and structural characterization of the NuMA-dynein mitotic interaction and was published last year on Structure. The second project focused on the study of the largely unknown role of NuMA in the nucleus during interphase. Regarding this part, I got interesting details on the NuMA-53BP1 (p53-binding protein 1) interaction in the context of liquid-liquid phase separation (LLPS).
In multicellular organisms, the proper organization of the mitotic spindle is essential for accurate cell division, tissue development and homeostasis. In vertebrate cells, the protein NuMA is a master regulator of mitotic spindle functions, implicated in spindle assembly and orientation, working together with the high molecular weight dynein-dynactin microtubule-motor complex. The domain structure of NuMA consists of an N-terminal globular domain, a central extended coiled-coil, and an unstructured C-terminal cargo-binding region. Whether NuMA is a dynein-dynactin activating adaptor is still not known. On these premises, the first part of my PhD project focused on the characterization of the NuMA-dynein binding interface, which I performed in collaboration with other members of the group. The crystal structure of the N-terminal head of NuMA (NuMA_1-153) revealed that it folds into a hook domain, a conserved feature of the Hook-family dynein-dynactin adaptors interacting directly with the Light Intermediate Chain (LIC) subunit of dynein. Pulldown assays performed with purified proteins indicated a direct interaction between NuMA_1-705 and LIC and identified four conserved residues in the NuMA hook domain that are crucial for LIC binding. Interestingly, sequence alignment between NuMA and known CC1-box containing dynein-dynactin adaptors revealed the existence of a CC1-box-like motif in the NuMA N-terminal coiled-coil domain (NuMA_365-376) that we demonstrated to be also implicated in contacting LIC. Thus, our studies identified two sites on NuMA’ N-terminus required for the interaction with a conserved hydrophobic helix in LIC1 C-terminus. Spindle positioning assays in human HeLa cells showed that these newly identified dynein-binding interfaces of NuMA are essential for correct mitotic progression. Collectively, these results support the notion that NuMA acts as a mitotic dynein-dynactin adaptor, forming complexes with similar topology to what observed for other known hook and CC1-box containing adaptors.
In vertebrate cells, NuMA accumulates in the nucleus during interphase and contributes to the DNA damage response (DDR), negatively regulating the 53BP1 double strand break (DSB) repair function. The second part of my PhD project focused on the characterization of the NuMA-53BP1 binding interface. By co-immunoprecipitation (co-IP) experiments in human HEK293T nuclear extracts with anti-NuMA antibodies, I confirmed that endogenous NuMA interacts with 53BP1, and that this interaction is decreased upon DNA damage induction. Interestingly, analytical size-exclusion chromatography (SEC) experiments with purified fragments revealed that the C-terminus of 53BP1 (53BP1_1484-1972) interacts directly with the C-terminus of NuMA (NuMA_1821-2115). These are two intrinsically disordered domains, common to proteins that undergo LLPS, a mechanism conferring spatial and temporal regulation to biological processes. Since 53BP1 forms DNA damage foci, which are LLPS condensates promoted by its C-terminal disordered region, I tested whether also NuMA is involved in this mechanism. Interestingly, I found that NuMA_1821-2115 forms liquid droplets in vitro at 20 uM and physiological salt concentrations, promoted by electrostatic and polar interactions. By co-IP experiments in HEK293T nuclear extracts, I also detected an interaction of NuMA with the MT nucleator TPX2. Since TPX2 counteracts the 53BP1 DSB repair function during replication stress and undergoes LLPS, I hypothesized that NuMA could work with TPX2 in regulating the DDR by forming dynamic LLPS condensates. Surprisingly, by co-IP experiments, an interaction between NuMA and 53BP1 was also scored during mitosis, where 53BP1 is known to be part of the centrosome surveillance pathway, another condensate-associated regulatory process.
Further studies are required to uncover the molecular basis and the functional role of the NuMA interaction with 53BP1 both in the DDR and in the centrosome surveillance pathway.
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Amdouni, Saber. « Numerical analysis of some saddle point formulation with X-FEM type approximation on cracked or fictitious domains ». Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0007/document.
Texte intégralRésumé :
Ce mémoire de thèse à été réalisée dans le cadre d'une collaboration scientifique avec "La Manufacture Française des Pneumatiques Michelin". Il porte sur l'analyse mathématique et numérique de la convergence et de la stabilité de formulations mixtes ou hybrides de problèmes d'optimisation sous contrainte avec la méthode des multiplicateurs de Lagrange et dans le cadre de la méthode éléments finis étendus (XFEM). Tout d'abord, nous essayons de démontrer la stabilité de la discrétisation X-FEM pour le problème d'élasticité linéaire incompressible en statique. Le deuxième axe, qui représente le contenu principal de la thèse est dédié à l'étude de certaines méthodes de multiplicateur de Lagrange stabilisées. La particularité de ces méthodes est que la stabilité du multiplicateur est assurée par l'ajout de termes supplémentaires dans la formulation faible. Dans ce contexte, nous commençons par l'étude de la méthode de stabilisation de Barbosa-Hughes appliquée au problème de contact unilatéral sans frottement avec XFEM cut-off. Ensuite, nous construisons une nouvelle méthode basée sur des techniques de projections locales pour stabiliser un problème de Dirichlet dans le cadre de X-FEM et une approche de type domaine fictif. Nous faisons aussi une étude comparative entre la stabilisation avec la technique de projection locale et la stabilisation de Barbosa-Hughes. Enfin, nous appliquons cette nouvelle méthode de stabilisation aux problèmes de contact unilatéral en élastostatique avec frottement de Tresca dans le cadre de X-FEMThis Ph.D. thesis was done in collaboration with "La Manufacture Française des Pneumatiques Michelin". It concerns the mathematical and numerical analysis of convergence and stability of mixed or hybrid formulation of constrained optimization problem with Lagrange multiplier method in the framework of the eXtended Finite Element Method (XFEM). First we try to prove the stability of the X-FEM discretization for incompressible elastostatic problem by ensured a LBB condition. The second axis, which present the main content of the thesis, is dedicated to the use of some stabilized Lagrange multiplier methods. The particularity of these stabilized methods is that the stability of the multiplier is provided by adding supplementary terms in the weak formulation. In this context, we study the Barbosa-Hughes stabilization technique applied to the frictionless unilateral contact problem with XFEM-cut-off. Then we present a new consistent method based on local projections for the stabilization of a Dirichlet condition in the framework of extended finite element method with a fictitious domain approach. Moreover we make comparative study between the local projection stabilization and the Barbosa-Hughes stabilization. Finally we use the local projection stabilization to approximate the two-dimensional linear elastostatics unilateral contact problem with Tresca frictional in the framework of the eXtended Finite Element Method X-FEM
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Berraki, Madjid. « Étude théorique et modélisation d'une source piézoélectrique enterrée unidirectionnelle pour applications sismiques ». Lille 1, 2004. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2004/50376-2004-Berraki.pdf.
Texte intégralRésumé :
Un problème commun de l'acquisition en sismique 4D et de l'imagerie des zones de piémont, est celui de la reproductibilité du signal source. En effet, d'une part, le principe du monitoring est de déceler des variations infimes au niveau du réservoir via des comparaisons de données sismiques ; d'autre part, l'imagerie des zones au relief chaotique requiert un signal peu perturbé. Aujourd'hui, les sources sismiques classiques, posées en surface, n'assurent pas cette reproductibilité. En premier lieu, il est impossible d'assurer à chaque acquisition un repositionnement de la source (camion vibrateur) au même endroit. De plus, au voisinage de la surface du sol, il existe une zone d'une dizaine de mètres d'épaisseur, appelée la zone altérée (Weathered Zone en anglais notée WZ), constituée d'un milieu dont les propriétés mécaniques varient avec les conditions climatiques. Ainsi, un signal émis par la source traversant cette zone peut être modifié par des variations climatiques ; il n'est donc pas reproductibleL'évolution des enregistrements effectués au niveau des récepteurs n'est pas attribuable uniquement aux variations dans le réservoir. La solution proposée dans cette thèse est la conception une source enterrée unidirectionnelle. La première partie expose un principe de source unidirectionnelle. Il s'agit de la combinaison, en milieu infini et en champ lointain, de forces ponctuelles dont les amplitudes complexes sont ajustées. La seconde partie décrit le rayonnement de la source unidirectionnelle idéale en milieu réel. Le modèle développé repose sur la détermination de la fonction de Green du milieu semi-infini, soit par méthode de Cagniard De Hoop (demi-espace), soit par méthode Réflectivité/DWN (milieu semi-infini stratifié). Un transducteur piézoélectrique unidirectionnel enterré, est modélisé dans la troisième partie. Le code éléments finis ATILA est utilisé pour modéliser la source piézoélectrique. Le milieu extérieur est représenté par sa matrice d'impédance, calculée soit par méthode itérative (demi-espace), soit par le code éléments de frontière MISSAXI (milieu semi-infini stratifié)
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Rakotondrandisa, Aina. « Modélisation et simulation numérique de matériaux à changement de phase ». Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR051/document.
Texte intégralRésumé :
Nous développons dans ce travail de thèse un outil de simulation numérique pour les matériaux à changement de phase (MCP), en tenant compte du phénomène de convection naturelle dans la phase liquide, pour des configurations en deux et trois dimensions. Les équations de Navier-Stokes incompressible avec le modèle de Boussinesq pour la prise en compte des forces de flottabilité liées aux effets thermiques, couplées avec une formulation de l’équation d’énergie suivant la méthode d’enthalpie, sont résolues par une méthode d’éléments finis adaptatifs. Une approche mono-domaine, consistant à résoudre les mêmes systèmes d’équations dans les phases solide et liquide, est utilisée. La vitesse est ramenée à zéro dans la phase solide, en introduisant un terme de pénalisation dans l’équation de quantité de mouvement, suivant le modèle de Carman-Kozeny, consistant à freiner la vitesse à travers un milieu poreux. Une discrétisation spatiale des équations utilisant des éléments finis de Taylor-Hood, éléments finis P2 pour la vitesse et éléments finis P1 pour la pression, est appliquée, avec un schéma d’intégration en temps implicite d’ordre deux (GEAR). Le système d’équations non-linéaires est résolu par un algorithme de Newton. Les méthodes numériques sont implémentées avec le logiciel libre FreeFem++ (www.freefem.org), disponible pour tout système d’exploitation. Les programmes sont distribués sous forme de logiciel libre, sous la forme d’une forme de toolbox simple d’utilisation, permettant à l’utilisateur de rajouter d’autres configurations numériques pour des problèmes avecchangement de phase. Nous présentons dans ce manuscrit des cas de validation du code de calcul, en simulant des cas tests bien connus, présentés par ordre de difficulté croissant : convection naturelle de l’air, fusion d’un MCP, le cycle complet fusion-solidification, chauffage par le bas d’un MCP, et enfin, la solidification de l’eauIn this thesis we develop a numerical simulation tool for computing two and three-dimensional liquid-solid phase-change systems involving natural convection. It consists of solving the incompressible Navier-Stokes equations with Boussinesq approximation for thermal effects combined with an enthalpy-porosity method for the phase-change modeling, using a finite elements method with mesh adaptivity. A single-domain approach is applied by solving the same set of equations over the whole domain. A Carman-Kozeny-type penalty term is added to the momentum equation to bring to zero the velocity in the solid phase through an artificial mushy region. Model equations are discretized using Galerkin triangular finite elements. Piecewise quadratic (P2) finite-elements are used for the velocity and piecewise linear (P1) for the pressure. The coupled system of equations is integrated in time using a second-order Gear scheme. Non-linearities are treated implicitly and the resulting discrete equations are solved using a Newton algorithm. The numerical method is implemented with the finite elements software FreeFem++ (www.freefem.org), available for all existing operating systems. The programs are written and distributed as an easy-to-use open-source toolbox, allowing the user to code new numerical algorithms for similar problems with phase-change. We present several validations, by simulating classical benchmark cases of increasing difficulty: natural convection of air, melting of a phase-change material, a melting-solidification cycle, a basal melting of a phase-change material, and finally, a water freezing case
Livres sur le sujet "Hook domain"
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Somin, Ilya. Robin Hood in reverse : The case against taking private property for economic development. Washington, D.C : Cato Institute, 2005.
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Longenbaugh, Nicholas, et Maria Polinsky. Experimental Approaches to Ergative Languages. Sous la direction de Jessica Coon, Diane Massam et Lisa Demena Travis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780198739371.013.29.
Texte intégralRésumé :
This chapter summarizes major results in the domain of experimental approaches to ergativity, focusing on three major topics. First, it discusses studies that explore the competition between accusative and ergative alignment, where researchers have attempted to derive the typological preference for accusative alignment from processing- and learnability based constraints. Next, it examines studies concerning the interrelated issues of long-distance dependencies and agreement. The unique dissociation of case and argument-hood in ergative languages has afforded researchers new means of testing conclusions regarding the privileged grammatical status of subject, the relative import and function of case and agreement in the grammar, and the origins of constraints on extraction in ergative languages and beyond. Given that linguists have only recently begun to conduct experimental research on ergative languages, we conclude by suggesting areas for future research where ergativity might provide genuine insights rather than just replicate existing studies of accusative languages.
Chapitres de livres sur le sujet "Hook domain"
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Cummings, Christopher L., Kaitlin M. Volk, Anna A. Ulanova, Do Thuy Uyen Ha Lam et Pei Rou Ng. « Emerging Biosecurity Threats and Responses : A Review of Published and Gray Literature ». Dans NATO Science for Peace and Security Series C : Environmental Security, 13–36. Dordrecht : Springer Netherlands, 2021. http://dx.doi.org/10.1007/978-94-024-2086-9_2.
Texte intégralRésumé :
AbstractThe field of biotechnology has been rigorously researched and applied to many facets of everyday life. Biotechnology is defined as the process of modifying an organism or a biological system for an intended purpose. Biotechnology applications range from agricultural crop selection to pharmaceutical and genetic processes (Bauer and Gaskell 2002). The definition, however, is evolving with recent scientific advancements. Until World War II, biotechnology was primarily siloed in agricultural biology and chemical engineering. The results of this era included disease-resistant crops, pesticides, and other pest-controlling tools (Verma et al. 2011). After WWII, biotechnology began to shift domains when advanced research on human genetics and DNA started. In 1984, the Human Genome Project (HGP) was formerly proposed, which initiated the pursuit to decode the human genome by the private and academic sectors. The legacy of the project gave rise to ancillary advancements in data sharing and open-source software, and solidified the prominence of “big science;” solidifying capital-intensive large-scale private-public research initiatives that were once primarily under the purview of government-funded programs (Hood and Rowen 2013). After the HGP, the biotechnology industry boomed as a result of dramatic cost reduction to DNA sequencing processes. In 2019 the industry was globally estimated to be worth $449.06 billion and is projected to increase in value (Polaris 2020).
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Kratzer, Angelika. « Chasing Hook : Quantified Indicative Conditionals ». Dans Conditionals, Paradox, and Probability, 40–57. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198712732.003.0004.
Texte intégralRésumé :
The chapter looks at indicative conditionals embedded under quantifiers, with a special emphasis on ‘one-case’ conditionals as in No query was answered if it came from a doubtful address. It agrees with earlier assessments that a complete conditional (with antecedent and consequent) is embedded under a quantifier in those constructions, but then proceeds to create a dilemma by showing that we can’t always find the right interpretation for that conditional. Contrary to earlier assessments, Stalnaker’s conditional won’t always do. The chapter concludes that the embedded conditional in the sentence above is a material implication, but the if-clause also plays a pragmatic role in restricting the domain of the embedding quantifier. That an appeal to pragmatics should be necessary at all goes with Edgington’s verdict that ‘we do not have a satisfactory general account of sentences with conditional constituents’.
Actes de conférences sur le sujet "Hook domain"
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Ko, Josephine, Maria Lung, Shiu-Yeung Lam, Lvwen Ning, Annie Chai, Lisa Lei et Sheyne Choi. « RAD50 loss of function variants in the zinc hook domain associated with higher risk of familial esophageal squamous cell carcinoma ». Dans The 1st International Electronic Conference on Cancers : Exploiting Cancer Vulnerability by Targeting the DNA Damage Response. Basel, Switzerland : MDPI, 2021. http://dx.doi.org/10.3390/iecc2021-09203.
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Ireland, J., G. Macfarlane et Y. Drobyshevski. « Investigation Into the Sensitivity of the Dynamic Hook Load During Subsea Deployment of a Suction Can ». Dans ASME 2007 26th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2007. http://dx.doi.org/10.1115/omae2007-29244.
Texte intégralRésumé :
Suction cans are commonly used as foundations of fixed offshore structures, subsea equipment, and anchors of mooring lines. During the offshore installation phase, when a suction can is submerged, it attracts large heave added mass, which may be an order of magnitude higher than the mass of the can in air. Due to motions of an installation vessel the dynamic hook load may significantly exceed the submerged weight of the can. The dynamic hook load must be accurately predicted, as it governs selection of the vessel, lifting gear and rigging, and defines the allowable installation sea state. The objective of this paper is to examine the sensitivity of the dynamic hook load to hydrodynamic properties of the suction can, in particular its heave added mass and damping. This research is motivated by the lack of data on such properties, which are usually estimated by simplified methods with some engineering judgement and assumptions. A single degree of freedom system is considered and the frequency domain spectral analysis is used, which employs the stochastic linearization of the nonlinear damping component. The added mass and damping of a 6-meter diameter suction can of dimensions typical for Australian North West Shelf developments have been determined by testing a 1:10 model in the 4.1 m deep basin of the Australian Maritime College. Free decay tests were conducted at several frequencies and the added mass, linear and nonlinear damping components determined. The effect of open hatches on the hydrodynamic properties was examined by fitting the model with hatches of various diameters, with up to 4.8% of the relative area open. Results of the tests demonstrate that the added mass and damping are higher, when compared with estimates based on empirical data for non-oscillatory flow. Within the Keulegan-Carpenter number range of 0.1–1.0, open hatches impact significantly on the added mass and produce additional damping, which is found to be linear with the heave velocity. Results of the tests and their interpretation are discussed. Sensitivity analysis shows that if the model test results are used in the dynamic lift analysis for an installation vessel and sea states considered, the predicted hook load is generally less than its values obtained by using simplified estimates. In particular, the increase in linear damping due to open hatches is responsible for up to 20% reduction in the dynamic hook load, with 2.4% of the relative top area open.
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Kanotra, Rahul, Mohamed Aboumalwa, Chellakat Joe-Joe, Sajith Nair et Vijoy Koottungal. « Dynamics of Heavy Deck Lift-Off From Transportation Barge ». Dans ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83458.
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The size of present day offshore topsides are growing rapidly, with large capacity, complex modules being transported and lifted offshore. This increase in size results in offshore lift weights which are near crane capacity of HLVs (heavy lift vessels). The offshore installation operation involves lift-off of heavy modules from a transportation barge moored perpendicular to the stern of the HLV. Previous experiences with lift analyses indicate that most significant hook load occurs while the module is being lifted off the transportation barge. This can be attributed to the fact that the crane vessel, topside and the transportation barge are all dynamically coupled together and during the “lift-off” condition the module experiences upward and downward impulsive forces from the transportation barge, which in turn increase the apparent weight of the module and hence the hook loads. This paper studies the dynamics of heavy deck lift-off from the transportation barge, when the sea fastening from the module has been removed and all three bodies (transportation barge, HLV and Module) are mechanically coupled through slings, lashings and fenders. The effect of various crane line pretensions, wave, current and wind has been investigated and the resulting DAFs (dynamic amplification factors) of the hook loads have been compared. The effect of wind and current on the lift operation has also been investigated. The “lift in air” case has been studied and compared with the “lift off” case. Multi Operational Structural Engineering Simulator (MOSES) has been used to carry out 3D time domain analysis of lift off and lift in air cases. McDermott’s HLV, 300 class transport barge and a topside weight of 1,500MT have been analyzed for the study.
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Duquesnay, Jillian, Jason Baldwin et James Wesley Rains. « Docking and Undocking Considerations for Floatover Analyses and Operations ». Dans ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-11340.
Texte intégralRésumé :
An alternative to lifted installation of topsides by a derrick barge is installation of single, integrated offshore platform topsides by floatover method. Floatover installation reduces hook-up and commissioning, which results in overall schedule and cost savings. Numerous papers were written recently to describe many aspects of the floatover operations. Nature of the floatover is such that it requires detailed engineering analyses, numerical simulations, model testing, and planning to evaluate all phases of the operation [Ref 5], [Ref 6]. Proper analysis of floatover requires numerical simulations using time-domain methodology to evaluate the system non-linearities inherent in the floatover hardware, fendering, mooring lines. Normally, weight transfer stages are given a high profile however it is found that the docking and undocking stages are equally as important. These sensitive stages of the floatover operation occur when the barge is entering the jacket slot prior to the floatover and exiting the jacket slot afterwards. The operation is sensitive to the prevailing weather and the number of simulations to make sure the operations can be performed safely is significant. Results of the docking and undocking analyses usually determine the weather standby and thus workability. This paper will address the docking and undocking stages of floatover for a barge that does not have its own propulsion. The paper shall include a concurrent investigation on effects of weather criteria. Stiffness of the hardware, mating lines/cross lines, mooring lines and the effect they have on the system will be discussed.
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Al Gharbi, Salem, Abdulaziz Al-Majed, Abdulazeez Abdulraheem, Shirish Patil et Salaheldin Elkatatny. « Using Data-Mining CRISP-DM Methodology to Predict Drilling Troubles in Real-Time ». Dans IADC/SPE Asia Pacific Drilling Technology Conference. SPE, 2021. http://dx.doi.org/10.2118/201026-ms.
Texte intégralRésumé :
Abstract Drilling is considered one of the most challenging and costly operations in the oil and gas industry. Several initiatives were applied to reduce the cost and increase the effectiveness of drilling operations. One of the frequent difficulties that faces these operations is unexpected drilling troubles that take place and stops the operation, resulting in losing a lot of time and money, and could lead to safety issues culminating in a fatality situation. For that, the industry is in continues efforts to prevent drilling troubles. Part of these efforts is utilizing the artificial intelligence (AI) technologies to identify troubles in advance and prevent them before maturing to a serious situation. Multiple approaches were tried; however, errors and significant deviation were observed when comparing the prediction results to the actual drilling data. This could be due to the improper design of the artificial intelligent technology or inappropriate data processing. Therefore, searching for dynamic and adequate artificial intelligent technology and encapsulated data processing model is very essential. This paper presents an effective data-mining methodology to determine the most efficient artificial intelligent technology and the applicable data processing techniques, to identify the early symptoms of drilling troubles in real-time. This methodology is CRISP-DM that stands for Cross Industry Standard Process for Data Mining. This methodology consists of the following phases: Business Understanding, Data Understanding, Data Preparation, Modeling, Evaluation and Deployment. During these phases, multiple data-quality techniques were applied to improve the reliability of the real-time data. The developed model presented a significant improvement in identifying the drilling troubles in advance, compared to the current practice. Parameters such as hook-load and bit-depth, were studied. Actual data from several oil fields were used to develop and validate this smart model. This model provided the drilling engineers and operation crew with bigger window to mitigate the situation and resolve it, prevent the occurrence of several drilling troubles, result in big time and cost savings. In addition to the time and cost savings, CRISP-DM provided the artificial intelligent experts and the drilling domain experts with a framework to exchange knowledge and sharply increase the synergy between the two domains, which lead to a common and clear understanding, and long-term successful drilling and AI teams collaboration. The novelty of this paper is the introduction of data-mining CRIPS methodology for the first time in the prediction of drilling troubles. It enabled the development of a successful artificial intelligence model that outperformed other drilling troubles prediction practices.
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Gharbi, Salem, Abdul Azeez Al Majed, Abdulazeez Abdulraheem, Shirish Patil et Salaheldin Elkatatny. « Using Data-Mining Crisp-DM Methodology to Predict Drilling Troubles In Real-time ». Dans SPE Conference at Oman Petroleum & Energy Show. SPE, 2022. http://dx.doi.org/10.2118/200105-ms.
Texte intégralRésumé :
Abstract Drilling is considered one of the most challenging and costly operations in the oil and gas industry. Several initiatives were applied to reduce the cost and increase the effectiveness of drilling operations. One of the frequent difficulties that faces these operations is unexpected drilling troubles that take place and stops the operation, resulting in losing a lot of time and money, and could lead to safety issues culminating in a fatality situation. For that, the industry is in continues efforts to prevent drilling troubles. Part of these efforts is utilizing the artificial intelligence (AI) technologies to identify troubles in advance and prevent them before maturing to a serious situation. Multiple approaches were tried in the past. However, errors and significant deviations were observed when comparing the prediction results to the actual drilling data. This could be due to improper design of the artificial intelligent technology or inappropriate data processing. Therefore, searching for dynamic and adequate artificial intelligent technology and encapsulated data processing model is very essential. This paper presents an effective data-mining methodology to determine the most efficient artificial intelligent technology and the applicable data processing techniques, to identify the early symptoms of drilling troubles in real-time. This methodology is CRISP-DM that stands for Cross Industry Standard Process for Data Mining. This methodology consists of the following phases: Business Understanding, Data Understanding, Data Preparation, Modeling, Evaluation and Deployment. During these phases, multiple data-quality techniques were applied to improve the reliability of the real-time data. The developed model presented a significant improvement in identifying the drilling troubles in advance, compared to the current practice. Parameters such as hook-load and bit-depth, were studied. Actual data from several oil fields were used to develop and validate this smart model. This model provided the drilling engineers and operation crew with bigger window to mitigate the situation and resolve it, prevent the occurrence of several drilling troubles. In addition to significant time and cost savings, CRISP-DM provided the artificial intelligent experts and the drilling domain experts with a framework to exchange knowledge and increase the synergy between the two domains significantly, leading to a common and clear understanding, and long-term successful drilling and AI teams collaboration. The novelty of this paper is the introduction of data-mining CRISP methodology for the first time in the prediction of drilling troubles. It enabled the development of a successful artificial intelligence model that outperformed other models in predicting drilling troubles.
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Vu Khac, Kien, Yang Zhang, Xiaofang Deng et Zhibin Yang. « Monohull Dynamics During Heavy Lift ». Dans ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-23068.
Texte intégralRésumé :
The dynamics of offshore heavy lift remains complex due to the interaction between the monohull construction vessel and the lifting object under the challenging environmental loads. This system becomes even more difficult to judge by common sense as the lifting weight offshore is usually above the motion reference point (the center of flotation of vessel), which makes the coupled system more unstable than the vessel without the lifting weight. This study proposes an analytical formula using the double pendulum, based on the Euler-Lagrangian equations, to explore the insight of the heavy lift dynamics. The effect of initial lifting condition is investigated to explain different possible outcomes for lifting similar weights. A range of vessel stiffness (GM), lifting heights and weights are considered in the parametric study for a better understanding of the coupled dynamic behaviour. While such analytical model is convenient for the understanding of the system mechanism, it is difficult to capture the effect from the wave loading. Therefore numerical models are used for this purpose. A comparison between the analytical model and the numerical model, performed in the frequency domain, evaluates the quality of ship motion response analysis performed by the numerical model. Results of these works will be useful in development of offshore crane curves for heavy lift offshore. Apart from the theoretical formulation, several real time ship instrumentation records including the ship motion and the crane hook load have been collected and investigated in this paper. The offshore instrumentation records provide a valuable benchmark to calibrate the numerical model or to accumulate “experience” for future projects. Challenges in such process are depicted and possible solutions are discussed. To make the comparison a fair “apple to apple”, the major difficulty arises from the “unknown” environment itself, where wave is not always measured and operation relies heavily on weather forecast and “experience”. There are also limitations in offshore measurement itself. Possibility of using the ship motion as the indicator is explored for decision making (to lift or not to lift). The paper develops a practical approach for obtaining reasonable numerical results in the engineering office and investigates scientifically sound interpretation of the ship motion time history onboard towards a safe offshore heavy lift.
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Niehof, J., H. H. J. M. Janssen, W. H. A. Schilders, W. Schoenmaker, D. Ioan, G. Ciuprina et W. Pflanzl. « Domain Decomposition via Electromagnetic Hooks for the Modeling of Complete RF blocks ». Dans 2008 IEEE Workshop on Signal Propagation on Interconnects (SPI). IEEE, 2008. http://dx.doi.org/10.1109/spi.2008.4558351.
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Chaitanya, Krishna, et Sajith B. Nair. « Design of Leg Mating Unit for Float-Over Installation of Decks ». Dans ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-10707.
Texte intégralRésumé :
The Leg Mating Unit (LMU) is a critical component in ensuring safe method of installing topsides of offshore oil and gas platforms by the float-over method. Traditionally, topsides are lifted onto the substructure (e.g. jacket) using heavy lift crane vessels. However, the ‘lift’ method of installation is constrained by the availability of a limited number of heavy lift vessels in the region, with high day rates. As an alternative to modular installation with light crane vessels, float-over installation enables installation of a single pre-commissioned integrated deck, minimizing offshore hook-up time and cost. Further, float-over method is particularly suited to shallow water depth locations, remote locations (with no access to crane vessels). In a float-over installation, the deck is transported on a cargo barge to the pre-installed substructure location. The barge is guided into the jacket slot and positioned so that the stabbing cone on each leg is aligned with the corresponding jacket leg. The barge is then ballasted down (aided by the falling tide) so that the topside load is transferred from the barge to the jacket. Once the load is transferred and sufficient clearance is achieved between the deck structure and barge support structure, the barge is withdrawn from the slot. The transfer of load is the crucial step of a float-over installation and should occur in a controlled manner under the dynamic influence of environmental forces. This smooth load transfer is achieved using LMU’s. LMU’s are customized leg and deck mating units, used to dampen the impact loads generated during the mating process. They consist of steel structures with elastomer elements and are designed to perform three primary functions, absorb shocks, limit hammering onto the structures and provide defined stiffness between deck and sub-structure. The objective of this paper is to outline the design philosophy of a LMU and address the behavior of the LMU under the combination of vertical and horizontal loads during the mating process. The paper also recommends guidelines on the selection of elastomer stiffness based on load-displacement relationship. The LMU is analysed in ABAQUS, a commercially available finite element (FE) analysis package considering a non-linear time-domain analysis. The results from the FE analysis are compared with the qualification tests for the elastomer and LMU assembly performed on-site to establish correlation.
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Yang, Rui, Jiandao Yang, Zeying Peng, Liqun Shi, Aping He, Hong Yang, Daiwei Zhou, Jun Li, Zhigang Li et Xin Yan. « Numerical Investigations on the Aerodynamic Performance of Last Stage – Exhaust Hood for Steam Turbines ». Dans ASME 2011 Power Conference collocated with JSME ICOPE 2011. ASMEDC, 2011. http://dx.doi.org/10.1115/power2011-55344.
Texte intégralRésumé :
The aerodynamic performance and internal flow characteristics of the last stage and exhaust hood for steam turbines is numerically investigated using the Reynolds-Averaged Navier-Stokes (RANS) solutions based on the commercial CFD software ANSYS CFX. The full last stage including 66 stator blades and 64 rotor blades coupling with the exhaust hood is selected as the computational domain. The aerodynamic performance of last stage and static pressure recovery coefficient of exhaust hood at five different working conditions is conducted. The interaction between the last stage and exhaust hood is considered in this work. The effects of the non-uniform aerodynamic parameters along the rotor blade span on the static pressure recovery coefficient of the non-symmetric geometry of the exhaust hood are studied. The numerical results show that the efficiency of the last stage has the similar values ranges from 89.8% to 92.6% at different working conditions. In addition, the similar static pressure recovery coefficient of the exhaust hood was observed at five working conditions. The excellent aerodynamic performance of the exhaust hood was illustrated in this work.