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Статті в журналах з теми "Sites de contacts membranaires"
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Böckler, Stefan, and Benedikt Westermann. "ER-mitochondria contacts as sites of mitophagosome formation." Autophagy 10, no. 7 (May 15, 2014): 1346–47. http://dx.doi.org/10.4161/auto.28981.
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Ng, Amanda Yunn Ee, Annabel Qi En Ng, and Dan Zhang. "ER-PM Contacts Restrict Exocytic Sites for Polarized Morphogenesis." Current Biology 28, no. 1 (January 2018): 146–53. http://dx.doi.org/10.1016/j.cub.2017.11.055.
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Chandiwana, S. K., and M. E. J. Woolhouse. "Heterogeneities in water contact patterns and the epidemiology of schistosoma haematobium." Parasitology 103, no. 3 (December 1991): 363–70. http://dx.doi.org/10.1017/s0031182000059874.
Повний текст джерелаАнотація:
Variations in the amount of water contact made by individuals and in the amount of water contact made at different sites may have significant impacts on patterns of human schistosome infection. Previous studies have reported variations in the rate of water contact and differences in the sites used between age/sex classes, but there is limited information on variations in individual water contact behaviour. In this paper we report and analyse observations of essentially all water contacts made over a two week period by all individuals in a rural community in eastern Zimbabwe. The mean rate of water contact was 0.43 contacts/person/day. These data were over-dispersed, ranging from zero to 3.3 contacts/person/day; 90% of contacts were made by only 37% of the population. Contact rates were related to age (highest in 8 to 10-year-olds) but not sex, with substantial variation unaccounted for by these variables. Age and sex classes differed in types of water-related activities and the time of day of contact. A greater diversity of sites was used by children than by adults and by males than by females. Individual contact rates were correlated with intensities of infection, although the risk of infection per contact was estimated to be highest in 2 to 4-year-old children and higher for males than females. Five contact sites were used during the study period, with more than 50% of contacts occurring at just 2 sites. Different age and sex classes used different sites and there were additional site-related differences in types of activity and the time of day of use. The implications of these water contact patterns for schistosome epidemiology are discussed. In particular the results provide strong quantitative support for control programmes aimed at heavily used sites (e.g. focal mollusciciding) or at the minority of individuals making most water contacts (e.g. targeted chemotherapy).
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Fernández-Busnadiego, Rubén, Yasunori Saheki, and Pietro De Camilli. "Three-dimensional architecture of extended synaptotagmin-mediated endoplasmic reticulum–plasma membrane contact sites." Proceedings of the National Academy of Sciences 112, no. 16 (March 18, 2015): E2004—E2013. http://dx.doi.org/10.1073/pnas.1503191112.
Повний текст джерелаАнотація:
The close apposition between the endoplasmic reticulum (ER) and the plasma membrane (PM) plays important roles in Ca2+ homeostasis, signaling, and lipid metabolism. The extended synaptotagmins (E-Syts; tricalbins in yeast) are ER-anchored proteins that mediate the tethering of the ER to the PM and are thought to mediate lipid transfer between the two membranes. E-Syt cytoplasmic domains comprise a synaptotagmin-like mitochondrial-lipid–binding protein (SMP) domain followed by five C2 domains in E-Syt1 and three C2 domains in E-Syt2/3. Here, we used cryo-electron tomography to study the 3D architecture of E-Syt–mediated ER–PM contacts at molecular resolution. In vitrified frozen-hydrated mammalian cells overexpressing individual E-Syts, in which E-Syt–dependent contacts were by far the predominant contacts, ER–PM distance (19–22 nm) correlated with the amino acid length of the cytosolic region of E-Syts (i.e., the number of C2 domains). Elevation of cytosolic Ca2+ shortened the ER–PM distance at E-Syt1–dependent contacts sites. E-Syt–mediated contacts displayed a characteristic electron-dense layer between the ER and the PM. These features were strikingly different from those observed in cells exposed to conditions that induce contacts mediated by the stromal interaction molecule 1 (STIM1) and the Ca2+ channel Orai1 as well as store operated Ca2+ entry. In these cells the gap between the ER and the PM was spanned by filamentous structures perpendicular to the membranes. Our results define specific ultrastructural features of E-Syt–dependent ER–PM contacts and reveal their structural plasticity, which may impact on the cross-talk between the ER and the PM and the functions of E-Syts in lipid transport between the two bilayers.
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Veerasamy, N., and W. A. Labuschagne. "Ascertaining Trust Indicators in Social Networking Sites." International Journal of Cyber Warfare and Terrorism 3, no. 2 (April 2013): 22–37. http://dx.doi.org/10.4018/ijcwt.2013040102.
Повний текст джерелаАнотація:
The use of social network sites has exploded with its multitude of functions which include posting pictures, interests, activities and establishing contacts. However, users may be unaware of the lurking dangers of threats originating from Social Networking Sites (SNS) which include malware or fake profiles. This paper investigates the indicators to arouse suspicion that a social networking account is invalid with a specific focus on Facebook as an illustrative example. The results from a survey on users’ opinions on social networks, is presented in the paper. This helps reveal some of the trust indicators that leads users to ascertaining whether a social networking profile is valid or not. Finally, indicators of potentially deceptive agents and profiles are given as a guideline to help users decide whether they should proceed with interaction with certain contacts.
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O'Reilly, Andrias O., Bhupinder P. S. Khambay, Martin S. Williamson, Linda M. Field, B. A. WAllace, and T. G. Emyr Davies. "Modelling insecticide-binding sites in the voltage-gated sodium channel." Biochemical Journal 396, no. 2 (May 15, 2006): 255–63. http://dx.doi.org/10.1042/bj20051925.
Повний текст джерелаАнотація:
A homology model of the housefly voltage-gated sodium channel was developed to predict the location of binding sites for the insecticides fenvalerate, a synthetic pyrethroid, and DDT an early generation organochlorine. The model successfully addresses the state-dependent affinity of pyrethroid insecticides, their mechanism of action and the role of mutations in the channel that are known to confer insecticide resistance. The sodium channel was modelled in an open conformation with the insecticide-binding site located in a hydrophobic cavity delimited by the domain II S4-S5 linker and the IIS5 and IIIS6 helices. The binding cavity is predicted to be accessible to the lipid bilayer and therefore to lipid-soluble insecticides. The binding of insecticides and the consequent formation of binding contacts across different channel elements could stabilize the channel when in an open state, which is consistent with the prolonged sodium tail currents induced by pyrethroids and DDT. In the closed state, the predicted alternative positioning of the domain II S4-S5 linker would result in disruption of pyrethroid-binding contacts, consistent with the observation that pyrethroids have their highest affinity for the open channel. The model also predicts a key role for the IIS5 and IIIS6 helices in insecticide binding. Some of the residues on the helices that form the putative binding contacts are not conserved between arthropod and non-arthropod species, which is consistent with their contribution to insecticide species selectivity. Additional binding contacts on the II S4-S5 linker can explain the higher potency of pyrethroid insecticides compared with DDT.
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Bloch, R. J. "Clusters of neural cell adhesion molecule at sites of cell-cell contact." Journal of Cell Biology 116, no. 2 (January 15, 1992): 449–63. http://dx.doi.org/10.1083/jcb.116.2.449.
Повний текст джерелаАнотація:
I have examined the distribution of neural cell adhesion molecule (N-CAM) in cultured C2 myogenic cells and other cell lines to determine if N-CAM accumulates at sites of cell-cell contact. C2 cells growing in log phase display large clusters of neural cell adhesion molecule where they contact each other. These clusters are remarkably stable, do not form at cell-substrate contacts, and appear not to be enriched in a number of other cytoskeletal, membrane, or extracellular proteins. Thus, N-CAM clusters form preferentially in response to cell-cell contact and are specifically enriched in N-CAM. As C2 cultures mature and differentiate, clusters persist at contacts between aligning myoblasts and between myotubes, consistent with a role in myogenesis. N-CAM is also enriched at cell-cell contacts in cultures of PC12, NRK, and CHO cells. These cells have significant amounts of N-CAM as detected on immunoblots. Clusters are not seen in L929 cells, which do not have detectable amounts of N-CAM. Coculture of these cells with C2 cells results in the clustering of N-CAM at heterologous contacts between C2 cells and NRK, CHO, or PC12 cells, but not between C2 cells and L929 cells. These results suggest that N-CAM specifically accumulates where N-CAM-bearing cells contact one another. Clustering of N-CAM may be an important step in strengthening intercellular adhesion.
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Singer, I. I., S. Scott, D. W. Kawka, D. M. Kazazis, J. Gailit, and E. Ruoslahti. "Cell surface distribution of fibronectin and vitronectin receptors depends on substrate composition and extracellular matrix accumulation." Journal of Cell Biology 106, no. 6 (June 1, 1988): 2171–82. http://dx.doi.org/10.1083/jcb.106.6.2171.
Повний текст джерелаАнотація:
We used antibodies against the alpha subunits of the human fibronectin receptor (FNR) and vitronectin receptor (VNR) to localize simultaneously FNR and VNR at major substrate adhesion sites of fibroblasts and melanoma cells with double-label immunofluorescence microscopy. In early (2-6-h) serum-containing cultures, both FNR and VNR coaccumulated in focal contacts detected by interference reflection microscopy. Under higher resolution immunoscanning electron microscopy, FNR and VNR were also observed to be distributed randomly on the dorsal cell surface. As fibronectin-containing extracellular matrix fibers accumulated beneath the cells at 24 h, FNR became concentrated at contacts with these fibers and was no longer detected at focal contacts. VNR was not observed at matrix contacts but remained strikingly localized in focal contacts of the 24-h cells. Since focal contacts represent the sites of strongest cell-to-substrate adhesion, these results suggest that FNR and VNR together play critical roles in the maintenance of stable contacts between the cell and its substrate. In addition, the accumulation of FNR at extracellular matrix contacts implies that this receptor might also function in the process of cellular migration along fibronectin-containing matrix cables. To define the factors governing accumulation of FNR and VNR at focal contacts, fibroblasts in serum-free media were plated on substrates coated with purified ligands. Fibronectin-coated surfaces fostered accumulation of FNR but not VNR at focal contacts. On vitronectin-coated surfaces, or substrata derivatized with a tridecapeptide containing the cell attachment sequence Arg-Gly-Asp, both FNR and VNR became concentrated at focal contacts. These observations suggest that the availability of ligand is critical to the accumulation of FNR and VNR at focal contacts, and that FNR might also recognize substrate-bound vitronectin.
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Rinnerthaler, G., B. Geiger, and J. V. Small. "Contact formation during fibroblast locomotion: involvement of membrane ruffles and microtubules." Journal of Cell Biology 106, no. 3 (March 1, 1988): 747–60. http://dx.doi.org/10.1083/jcb.106.3.747.
Повний текст джерелаАнотація:
We have correlated the motility of the leading edge of fibroblasts, monitored by phase-contrast cinematography, with the relative distributions of several cytoskeletal elements (vinculin, tubulin, and actin) as well as with the contact patterns determined by interference reflection microscopy. This analysis has revealed the involvement of both ruffles and microspikes, as well as microtubules in the initiation of focal contact formation. Nascent vinculin sites within the leading edge or at its base, taken as primordial cell-substrate contacts, were invariably colocalized with sites that showed a history of transient, prolonged, or cyclic ruffling activity. Extended microspike structures, often preceded the formation of ruffles. Immunofluorescent labeling indicated that some of these primordial contacts were in close apposition to the ends of microtubules that penetrated into the leading edge. By fluorescence and electron microscopy short bundles of actin filaments found at the base of the leading edge were identified as presumptive, primordial contacts. It is concluded that ruffles and microspikes, either independently or in combination, initiate and mark the sites for future contact. Plaque proteins then accumulate (within 10-30 s) at the contract site and, beneath ruffles, induce localized bundling of actin filaments. We propose that all primordial contacts support traction for leading edge protrusion but that only some persist long enough to nucleate stress fiber assembly. Microtubules are postulated as the elements that select, stabilize, and potentiate the formation of these latter, long-lived contacts.
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Wong, Louise H., and Tim P. Levine. "Lipid transfer proteins do their thing anchored at membrane contact sites… but what is their thing?" Biochemical Society Transactions 44, no. 2 (April 11, 2016): 517–27. http://dx.doi.org/10.1042/bst20150275.
Повний текст джерелаАнотація:
Membrane contact sites are structures where two organelles come close together to regulate flow of material and information between them. One type of inter-organelle communication is lipid exchange, which must occur for membrane maintenance and in response to environmental and cellular stimuli. Soluble lipid transfer proteins have been extensively studied, but additional families of transfer proteins have been identified that are anchored into membranes by transmembrane helices so that they cannot diffuse through the cytosol to deliver lipids. If such proteins target membrane contact sites they may be major players in lipid metabolism. The eukaryotic family of so-called Lipid transfer proteins Anchored at Membrane contact sites (LAMs) all contain both a sterol-specific lipid transfer domain in the StARkin superfamily (related to StART/Bet_v1), and one or more transmembrane helices anchoring them in the endoplasmic reticulum (ER), making them interesting subjects for study in relation to sterol metabolism. They target a variety of membrane contact sites, including newly described contacts between organelles that were already known to make contact by other means. Lam1–4p target punctate ER–plasma membrane contacts. Lam5p and Lam6p target multiple contacts including a new category: vacuolar non-NVJ cytoplasmic ER (VancE) contacts. These developments confirm previous observations on tubular lipid-binding proteins (TULIPs) that established the importance of membrane anchored proteins for lipid traffic. However, the question remaining to be solved is the most difficult of all: are LAMs transporters, or alternately are they regulators that affect traffic more indirectly?
Дисертації з теми "Sites de contacts membranaires"
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Jemaiel, Aymen. "Etude du trafic membranaire vésiculaire et non-vésiculaire chez la levure." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112348/document.
Повний текст джерелаАнотація:
Les cellules eucaryotes sont caractérisées par le cloisonnement des organelles par des membranes. La communication entre les différents compartiments cellulaires est assurée par deux voies de transport : le transport vésiculaire et transport non-vésiculaire. Le transport vésiculaire permet à la fois le trafic des protéines et des lipides d'un compartiment à un autre, alors que le transport non-vésiculaire permet uniquement le trafic des lipides. En effet, les lipides jouent un rôle essentiel dans l'organisation cellulaire. Au cours de ma thèse, je me suis intéressé au rôle des lipides dans le trafic intracellulaire, en utilisant la levure comme organisme modèle. Dans une première partie de ma thèse, j'ai étudié les hélices amphipathiques qui permettent le ciblage des protéines vers des compartiments cellulaires spécifiques. Dans une étude précédente, réalisé au laboratoire a montré que ces hélices amphipathiques interagissaient directement avec les lipides membranaires, ce qui permet un adressage spécifique des protéines en fonction des environnements lipidiques dans la cellule. Deux hélices amphipatiques ont fait l’objet de cette étude : le motif ALPS qui cible les vésicules de la voie sécrétoire précoce, et alpha-synucléine qui reconnaît et fixe les vésicules du compartiment trans-Golgi-membrane plasmique. Dans cette première partie de la thèse j’ai cherché à identifier des motifs similaires à celui d’alpha-synucléine dans les protéines de levure, et de déterminer leurs rôles dans la cellule. Dans une seconde partie de ma thèse, en collaboration avec le laboratoire du Dr Thierry Galli, j'ai étudié de nouveaux composants impliqués dans le métabolisme lipidique aux sites de contact entre le réticulum endoplasmique et la membrane plasmique. Les sites de contact membranaires sont des régions de proches appositions (de l'ordre de 10 à 30 nm) entre deux membranes, généralement entre la membrane du réticulum endoplasmique (RE) et une autre organelle. Ce sont principalement des sites de transfert des lipides et d'ions. Maja Petkovic dans le laboratoire de Thierry Galli a fait la découverte que la protéine SNARE du RE, Sec22, interagit avec une syntaxine (Stx1) de la membrane plasmique dans les neurones, ce qui permet un nouveau mécanisme de contact entre ces deux membranes. J’ai donc essayé de voir si ce mécanisme est conservé chez la levure. Les résultats que j'ai obtenus ont confirmé que la levure Sec22 est capable d'interagir avec une protéine SNARE SSO1 localisée à la membrane plasmatique et homologue de Stx1. J'ai trouvé par co-immunoprecipitation que Sec22 et SSO1 deux interagissent avec les protéines de transfert des lipides localisées aux sites de contact. L'utilisation d'une sonde spécifique au Phosphatidylinositol-4 phosphate (PI4P), nous a permis de montrer que Sec22 est impliquée dans la régulation du niveau de PI4P à la membrane plasmique. Pour disséquer les deux fonctions de Sec22, dans la voie sécrétoire et aux sites de contact, nous avons utilisé l'approche des suppresseurs multicopies dans la levure. Parmi les suppresseurs identifiés, nous avons trouvé le Sfh1, une protéine qui a un rôle potentiel dans le transfert des lipides. Ces résultats confirment bien ceux obtenus par l’équipe de Thierry Galli, montrant que Sec22 a un nouveau rôle aux sites de contact entre le RE et la membrane plasmique et suggèrent que ce complexe SNARE pourrait être impliqué dans transfert de lipides chez la levureEukaryotic cells are characterized by their internal membrane compartmentalization, with the various specialized organelles of the cell bounded by lipid membranes. Communication between different cellular compartments occurs via two transport pathways: vesicular transport and non-vesicular transport. Vesicular transport carries both proteins and lipids from one compartment to another in cells, whereas non-vesicular transport carries only lipids. An emerging idea is the important role that lipids play in cellular organization. Lipid binding amphipathic helices such as the ALPS (amphipathic lipid packing sensor) motif are targeted to membranes of a specific lipid composition, and hence act to transfer information encoded in membrane lipids to the vesicle trafficking machinery. The lipid composition of the membranes of different organelles is therefore of great importance. One mechanism that cells use to maintain the distinct lipid compositions of organelles is lipid transport, which occurs preferentially at membrane contact sites (MCS). MCS are regions of close appositions, on the order of 10 to 30 nm, between two membranes, generally between the membrane of the endoplasmic reticulum (ER) and another organelle. In my thesis, I addressed two aspects of how lipids and their transport function in intracellular trafficking, using yeast as a model system. First, I studied amphipathic motifs that mediate targeting of proteins to specific compartments in cells. Lipid binding amphipathic helices were shown in a previous study in the laboratory to mediate specific targeting to distinct lipid environments via direct protein-lipid interactions, both in vitro and in cells. One of these, the ALPS motif, targets vesicles of the early secretory pathway. The other, alpha-synuclein, targets vesicles travelling between the late Golgi, the plasma membrane and endosomes. I studied new potential alpha-synuclein-like motifs in yeast proteins, and their roles in cells. In a second project, in collaboration with the laboratory of Dr. Thierry Galli, I studied new compenents involved in lipid metabolism at contact sites between the endoplasmic reticulum and the plasma membrane. Maja Petkovic in the laboratory of Thierry Galli made the important discovery that the ER-localized SNARE protein Sec22 interacts with a plasma membrane syntaxin in neurons, thus providing a novel mechanism for mediating close contact between these two membranes. I addressed the question of whether this mechanism is conserved in yeast. The results I obtained confirmed that yeast Sec22 is able to interact with a SNARE protein localized to the plasma membrane, Sso1. I found by co-immunoprecitation that Sec22 and Sso1 both interact with lipid transfer proteins localized to ER-plasma membrane contact sites. Using a specific probe for phosphatidylinositol-4 phosphate (PI4P), we showed that Sec22 was involved in regulating the level of PI4P at the plasma membrane. These results extend to yeast those obtained by Maja Petkovic, Thierry Galli and colleauges showing that Sec22 has a novel role at ER-plasma membrane contact sites, and suggest that this SNARE complex might be implicated in lipid transfer at these sites in yeast
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Di, Mattia Thomas. "Identification et caractérisation de la protéine MOSPD2, un bâtisseur de sites de contact membranaire impliquant le réticulum endoplasmique." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAJ043.
Повний текст джерелаАнотація:
Les sites de contact membranaire (SCM) sont des régions subcellulaires où deux organites sont physiquement connectés. Ces micro-domaines, moléculairement définis par des interactions protéine-protéine et/ou protéine-membrane, sont impliqués dans la dynamique des organites et la communication inter-organites. Le champ disciplinaire des SCM s’enrichit constamment grâce à la découverte de nouveaux acteurs moléculaires impliqués dans l'attachement des organites entre eux. Dans ce contexte de recherche, nous avons identifié un nouvel acteur impliqué dans la formation de SCM, appelé MOSPD2 (motile sperm domain-containing protein 2). Cette protéine est ancrée dans la membrane du réticulum endoplasmique (RE) ; elle peut interagir grâce à son domaine MSP avec d’autres protéines (associées à d’autres organites cellulaires) dont la caractéristique commune est de posséder un court motif protéique nommé FFAT. Par ces interactions, MOSPD2 permet l’établissement de SCM entre le RE et les endosomes, les mitochondries et l’appareil de Golgi. Ces résultats montrent une nouvelle façon de piéger des organites dans le grand filet cytoplasmique qu’est le REMembrane contact sites (MCS) are specific subcellular regions where two organelles are physically connected. Such micro-domains - molecularly defined by protein-protein and/or protein membrane interactions - are involved in organelle dynamic and inter-organelle communication. The field of MCS is constantly expanding thanks to the discovery of new molecular actors involved in organelle tethering. In this context of research, we identified MOSPD2 (motile sperm domain-containing protein 2) as a new factor involved in the formation of MCS. The MOSPD2 protein is anchored to the membrane of the endoplasmic reticulum (ER); it is able to interact thanks to its MSP domain with other organelle-associated proteins which common feature is to have a short protein motif called FFAT. By binding with its protein partners, MOSPD2 establishes MCS between the ER and endosomes, mitochondria and the Golgi apparatus. These results show how a large net covering the entire cytoplasm made by the ER can trap a large variety of cellular organelles
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Gallo, Alessandra. "Role of non-vesicular secretion in neuronal development." Thesis, Université de Paris (2019-....), 2019. https://theses.md.univ-paris-diderot.fr/GALLO_Alessandra_va.pdf.
Повний текст джерелаАнотація:
La croissance des neurites au cours du développement neuronal nécessite une expansion de la membrane plasmique (MP) via l’insertion de nouveaux lipides et protéines. Cet événement se produit à la suite de la fusion des vésicules de sécrétion avec la MP. Cependant, plusieurs études ont montré que le transfert non-vésiculaire de lipides au niveau des sites de contact entre le réticulum endoplasmique (RE) et la MP joue aussi un rôle dans la croissance des cellules. Des membres de la famille de synaptotagmines étendues (E-Syts) ont été identifiés comme protéines de transfert des lipides dépendantes du Ca2+ au niveau des jonctions RE-MP.Nous avons découvert qu’un nouveau complexe SNARE aux sites de contact RE-MP, composé par Sec22b et Stx1, est impliqué dans la croissance des neurites bien qu’il soit incapable de favoriser la fusion membranaire. Cependant, la manière dont ce complexe participe à l’extension des neurites reste à élucider. Chez la levure, Sec22 interagit avec les protéines de transfert des lipides de la famille OSH, enrichis aux sites de contact RE-MP.Sur la base de ces observations, notre hypothèse est que le transfert non-vésiculaire de lipides induit par E-Syts au niveau des jonctions RE-MP contenant Sec22b pourrait contribuer à la croissance neuronale. L’objectif de ma thèse était d’explorer cette hypothèse. Nous montrons que Sec22b interagit avec E-Syt2 et Stx1 dans les cellules PC12 et avec E-Syt2, E-Syt3 et Stx3 dans les cellules HeLa. L’interaction Sec22b/E-Syt2 dépend du domaine Longin de Sec22b. La surexpression des E-Syts stabilise l’association Sec22b/Stx1, alors que l’inactivation des E-Syts provoque l’effet inverse. La surexpression de E-Syt2 de type sauvage, mais pas des mutants incapables de transférer les lipides ou non fixés au RE, augmentent la formation de filopodes axonaux et la ramification de neurites dans les neurones en développement. Cet effet est inhibé par une neurotoxine clostridiale clivant Stx1, par l’expression du domaine Sec22b Longin et par un mutant Sec22b ayant une extension entre les domaines SNARE et transmembranaire.En conclusion, mes résultats soutiennent l’idée que les sites de contact Sec22b/Stx1 contribuent à l’expansion de la MP via une interaction avec des protéines de transfert de phospholipides comme E-SytsThe growth of neurites during neuronal development requires a massive increase of surface area via the insertion of new proteins and lipids. This event occurs through the fusion of secretory vesicles with the plasma membrane (PM), the final step of the secretory pathway. Recently, non-vesicular transfer of lipids at contacts between endoplasmic reticulum (ER) and PM was shown to contribute to membrane expansion. Members of the ER-integral membrane protein Extended-Synaptotagmin (E-Syt) family have been identified as Ca2+-dependent lipid transfer proteins at ER-PM contact sites, and shown to transfer glycerophospholipids via their lipid binding domains. The laboratory previously found that a novel ER-PM SNARE complex, composed of the ER-resident Sec22b and the neuronal plasmalemmal Stx1, is involved in neurite growth despite being unable to mediate membrane fusion. However, how this complex participates to neurite extension remained to be elucidated. In yeast, Sec22 interacts with lipid transfer proteins of the OSH family, enriched at the ER- PM contacts, supporting a role for Sec22b-populated ER- PM junctions in non-vesicular lipid transport between these bilayers. Based on these observations, our starting hypothesis was that E-Syts-mediated non-vesicular lipid transfer at Sec22b-populated ER-PM contacts, might contribute to neurite growth. The goal of my PhD was to explore this hypothesis with two specific questions: 1-What are the partners of Sec22b complexes which might be involved in the unconventional mechanisms of membrane expansion? 2-What is the mechanism whereby the non-fusogenic SNARE Sec22b/Stx1 complex acts in neuronal development?Here we show that Sec22b interacts with E-Syt2 and Stx1 in PC12 cells and with E-Syt2, E-Syt3 and Stx3 in HeLa cells. Overexpression of E-Syt2 stabilized Sec22b-Stx3 association, whereas silencing of E-Syt2 had the opposite effect. Overexpression of E-Syt2 full length, but not the mutant forms which are unable to transfer lipids or attach to the ER, increased the formation of filopodia particularly in the growing axon. Finally, this effect was inhibited by a clostridial neurotoxin cleaving Stx1, by the expression of Sec22b Longin domain and a by a Sec22b mutant with extended linker between SNARE and transmembrane domains.In conclusion, these results support the hypothesis that Sec22b/Stx1 junctions may contribute to membrane expansion via an interaction with phospholipid transfer proteins like E-Syts
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Petit, Jules. "Membrane Tethering in Plant Intercellular Communication : Structure-Function of Multiple C2 domains and Transmembrane Region Proteins (MCTP) at Plasmodesmata ER-PM Membrane Contact Site." Thesis, Bordeaux, 2022. https://tel.archives-ouvertes.fr/tel-03789611.
Повний текст джерелаАнотація:
La multicellularité chez les plantes repose sur une communication intercellulaire qui permette le transfert d'informations à travers l'entièreté de l'organisme. Chez les plantes terrestres, la route principale de ces “conversations cellulaires” est assurée par les plasmodesmes (PD), des canaux nanoscopiques qui traversent la paroi pecto-cellulosique. En effet, ces pores sont impliqués dans la circulation d'une très grande variété de molécules, comme des facteurs de transcription, de l'ARN, des hormones et des métabolites et ceci à tous les stades de la vie végétale, permettant réponses et adaptations à l'environnement. Les PD sont particuliers dans le sens où ils forment une continuité du réticulum endoplasmic (RE), de la membrane plasmique (MP) et du cytoplasme entre les cellules adjacentes. Leur architecture est singulière et consiste en un filament de RE, appelé desmotubule, entouré d'un tube de MP qui, lui, longe la paroi. Les PD sont actuellement décrits comme des sites de contact membranaire, du fait du fort accolement des membranes du RE et de la MP (2 à 10 nm) et de la présence de protéines de jonction qui connectent les deux organelles. Dans la présente étude, nous décrivons au niveau structural et fonctionnel plusieurs membres de la famille des MCTPs (protéine avec de multiples domaines C2 et une région transmembranaire) comme protéines assurant la jonction du RE et de la MP dans les PD. Nous démontrons que ces protéines possèdent les caractéristiques moléculaires nécessaires à l'interaction transitoire avec les lipides anioniques de la MP, via leurs domaines C2, ainsi qu'à l'induction de courbure membranaire au RE, via la région transmembranaire qui agit comme un domaine homologue aux protéines réticulons. Ces données nous ont permis de corréler la fonction des MCTPs à l'architecture et la biogenèse des PD et de réfléchir au rôle du RE à l'intérieur des PD. En conclusion, ce travail a fourni des résultats originaux qui placent les MCTPs comme des protéines centrales dans l'établissement de la structure fine des PD et des fonctions qui y sont associéesPlant multicellularity relies on intercellular communication in order to transmit information from cell to cell and throughout the entire plant body. In land plants, the major line for such cellular conversations is through plasmodesmata (PD) pores, which are nanoscopic membranous tunnels spanning the pecto-cellulosic cell wall. These pores are indeed involved in the transfer of a wide variety of molecules such as transcription factors, RNAs, hormones and metabolites during all stages of plant life, adaptation and responses to their environment. PD are singular amongst other types of intercellular junctions as they provide a direct continuity of the endoplasmic reticulum (ER), the plasma membrane (PM) and the cytosol between neighboring cells. Their architectural organization can be summarized as followed: a thin strand of constricted ER, called desmotubule, is encased in a tube of PM lining the cell wall. PD are seen as a specialized ER-PM membrane contact sites from the very close apposition (2 to 10 nm) of the ER and PM membranes and the presence of tethering elements bridging the two organelles. In this study, we describe the structural organization and function of several members of the MCTP (Multiple C2 domains and Transmembrane region Protein) family which act as ER-PM tethering elements at PD. We show that these proteins possess molecular features capable of transient interaction with anionic lipids of the PM, through their C2 domains, as well as ER membrane shaping, through their transmembrane region which presents homology to a reticulon domain. We further correlate MCTP function with PD architecture and biogenesis, and investigate on the role of the ER inside PD. Altogether, this work provides original data placing MCTPs as core PD proteins that appear to be crucial in the establishment of PD ultrastructure and associated functions
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Nicolas, William. "Understanding plasmodesmata membrane organization and the control of cell-to-cell connectivity in plants." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0213.
Повний текст джерелаАнотація:
La communication intercellulaire est essentielle pour le développement et la survie d'organismes multicellulaires. Dans le règne végétale, une des voies privilégiée pour la communication intercellulaire est la voie symplastique qui implique des canaux aux dimensions nanométriques connectant les cellules entre elles, leur permettant d'échanger directement photo-assimilats, miARN, protéines, oligoéléments etc. Observés pour la première fois en 1880 par le botaniste autrichien Eduard Tangl (Tangl 1880; Kohler & Carr 2006), ils ont longtemps été considérés comme de simples trous perméables permettant la diffusion de matériel cellulaire (Lee & Lu 2011; Oparka & Roberts 2001). Etant donné leurs taille nanoscopique, ce n'est que dans les années 1960, avec la démocratisation de la Microscopie Électronique en Transmission (MET) qui permet d'atteindre , que les premiers modèles ultrastructuraux sont établis (Lopez-Saez 1965; Robards 1970). Ils font état d'un canal d'environ 30 à 40 nm de diamètre avec un élément central cylindrique traversant le pore, appelé le desmotubule, connecté au Réticulum Endoplasmique des deux cellules (Figure 1 of our review Tilsner et al. 2016). Dans les années 1980 notre compréhension des plasmodesmes a quelque peu évolué et nous savons maintenant que ces structures ne sont pas de simples trous mais des structures membranaires très spécialisées et régulées (Lucas & Lee 2004; Faulkner & Maule 2011; Furuta et al. 2012). Le modèle ultrastructural actuel découle de la congrégation d'études ultrastructurale, physiologiques et pharmacologiques plus ou moins anciennes dépeignant une structure morphologiquement très souple et changeant de conformation au cours du développement. Les plasmodesmes peuvent réguler leur ouverture/fermeture par la constriction de leurs extrémités grâce à l'accumulation entre la membrane plasmique et la paroi végétale d'un polymère de sucre, la callose qui va pousser la membrane plasmique contre le desmotubule et en obstruer les entrées. Cette modulation permettrait majoritairement de réguler les flux intercellulaires qui impliquent les plasmodesmes. Cependant nos connaissances sur les remaniements membranaires prenant place durant le développement des plasmodesmes et sur la régulation de leur perméabilité sont encore imparfaites.La microscopie électronique en transmission, malgré l'ancienneté de la technique, est l'une des plus résolutive, largement utilisée en biologie. Avec l'amélioration des techniques de préservation d'échantillons, notamment les cryo- méthodes, elle permet d'atteindre à l'heure actuelle des résolutions inférieures à 5 nm en condition contrastée et inclus en résine et peut descendre en dessous du nanomètre pour la cryo-microscopie. Ce potentiel permet aisément l'étude des sous-compartiments cellulaires de l'ordre du µm tel que mitochondries, chloroplastes, noyaux etc. (Frey et al. 2002) mais permet également l'étude ultrastructurale précise de structures de l'ordre de la dizaine de nm (Beck et al. 2007; Al-Amoudi et al. 2007).En revanche, dans son utilisation classique, la microscopie électronique ne permet pas d'accéder à la troisième dimension de l'espace, rendant difficile l'interprétation de structure à l'architecture quelque peu compliquée. En effet, les images produites ne sont que des projections en deux dimensions d'objets en trois dimensions. Cela a mené au développement de la tomographie électronique en transmission (Crowther et al. 1970), méthode basée sur un concept mathématiques formulé par Johann Radon au XIXe siècle. Ce n'est que dans les années 2000 que la tomographie électronique a pris un essor significatif grâce au couplage avec des méthodes d'automatisation informatiquesPlasmodesmata were first observed by Austrian botanist Eduard Tangl in 1880. He devoted himself to studying the anatomy and cytology of plants and his greatest discovery, of course, was the observation and first characterization of plasmodesmata (Tangl 1880, 1884 and 1885). Despite not having access to their ultrastructure, he observed thin striations (see front page engraving) between cotyledon cells of Strychnos nuxvomica and in the endosperm of seeds and described them as being conductive ducts. Already at the time, he was evoking the idea that these strands "unite them [the cells] to an entity of higher order", in other words formulating the first definition of a symplastic domain. lt is only in 1901 that Strasburger finally names these canals "plasmodesmata". His discovery led to a radical change in our conception of the plant entity and brought in new concepts such as the symplasm (Munch 1930) and transmembrane fluxes between cells, which are now being tackled with great interest by numerous research teams around the globe.Because of their size, plasmodesmata ultrastructure was not accessible until the advent of electron microscopy and they were long thought to be simple holes connecting plant cells one-another with no specific regulation. lt is only with the advent of electron microscopy and chemical fixation that botanists started to gain interest in this structure again. And even with these methods allowing the observation of structures down to several nanometers in size, there are still debates on the nature of the canal, its constituents and physiology (Lopez-Saez J. 1965, Robards A. 1970, Ding et al. 1992, Tilney et al. 1991, Overall and Gunning 1982, Schulz et al. 1995).Nowadays, with the advent of modern cryopreservation and three-dimensional electron tomography methods, great improvements are to be done in the understanding of the ultrastructure and physiology of these mysterious canals. More particularly by understanding the link between the membranous rearrangements taking place in these pores and the molecular transit regulation.My work has led us to view plasmodesmata as specialised Membrane Contact Sites (MCS). Hence, by analogy with MCS found in mammals, yeast and plants, this work embraces an original angle on the speculation of the composition and role of the desmotubule-plasma-membrane tethering complex. The work produced during my thesis allowed me to contribute to the publication of one review and two articles, which will constitute the introduction and two main sub-sections of the results chapter, respectively. The introductory review has been published in 2016 in Annual Review of Plant Biology. The first one is still under reviewing at Nature Plant and the other has been published in The Plant Cell journal in April 2015
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Jamecna, Denisa. "Une région intrinsèquement désordonnée dans OSBP contrôle la géometrie et la dynamique du site de contact membranaire." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4229/document.
Повний текст джерелаАнотація:
La protéine OSBP est un transporteur de lipides qui régule la distribution cellulaire du cholestérol. OSBP comprend un domaine PH, deux séquences « coiled coil », un motif FFAT (deux phénylalanines dans un environement acide), et un domaine de liaison de lipides (ORD) à son extrémité C-terminale. Le domaine PH interagit avec le PI(4)P et la petite protéine G Arf1-GTP au niveau du Golgi, alors que le motif FFAT interagit avec la protéine VAP-A, résidente du réticulum endoplasmique (RE). En liant simultanément tous ces déterminants, OSBP stabilise des sites de contact membranaire entre RE et Golgi, permettant ainsi un contre-échange cholestérol / PI(4)P par l'ORD. OSBP contient également une longue séquence N-terminale d’environ 80 aa, intrinsèquement désordonnée, composée principalement de glycine, proline et d'alanine. Nous démontrons que la présence de ce N-terminus désordonné augmente le rayon de Stoke de OSBP tronquée du domaine ORD, et limite sa densité d’association sur la membrane portant le PI(4)P. La protéine dépourvue du N terminus favorise l'agrégation symétrique des liposomes PI(4)P (mimant la membrane du Golgi) par les deux domaines PH du dimère OSBP, alors que la présence de la séquence désordonnée empêche cette association symétrique. De même, nous observons que la distribution d’OSBP sur la membrane de vésicules unilamellaires géantes (GUV) varie selon la présence ou l'absence du N-terminus. En présence de la séquence désordonnée, la protéine est répartie de manière homogène sur toute la surface du GUV, alors que la protéine sans N-terminal a tendance à s'accumuler à l'interface entre deux GUV de type Golgi. Cette accumulation locale ralentit fortement la mobilité de la protéine à l’interface. Un effet similaire du N-terminal sur la dynamique des protéines est observé lorsque l’association de membranes de type ER et Golgi est assuré par des protéines monomériques (dépourvue du coiled coil) en présence de Vap-A. Les résultats de nos expériences in vitro ont été confirmés en cellules vivantes, où la séquence intrinsèquement désordonnée contrôle le recrutement d’OSBP sur les membranes Golgiennes, sa mobilité et sa dynamique d’activité au cours des cycles de transfert de lipides. La plupart des protéines de la famille d’OSBP contiennent des séquences N-terminales de faible complexité, suggérant un mécanisme général de régulationOxysterol binding protein (OSBP) is a lipid transfer protein that regulates cholesterol distribution in cell membranes. OSBP consists of a pleckstrin homology (PH) domain, two coiled-coils, a “two phenylalanines in acidic tract” (FFAT) motif and a C-terminal lipid binding OSBP-Related Domain (ORD). The PH domain recognizes PI(4)P and small G protein Arf1-GTP at the Golgi, whereas the FFAT motif interacts with the ER-resident protein VAP-A. By binding all these determinants simultaneously, OSBP creates membrane contact sites between ER and Golgi, allowing the counter-transport of cholesterol and PI(4)P by the ORD. OSBP also contains an intrinsically disordered ~80 aa long N-terminal sequence, composed mostly of glycine, proline and alanine. We demonstrate that the presence of disordered N-terminus increases the Stoke’s radius of OSBP truncated proteins and limits their density and saturation level on PI(4)P-containing membrane. The N-terminus also prevents the two PH domains of OSBP dimer to symmetrically tether two PI(4)P-containing (Golgi-like) liposomes, whereas protein lacking the disordered sequence promotes symmetrical liposome aggregation. Similarly, we observe a difference in OSBP membrane distribution on tethered giant unilamellar vesicles (GUVs), based on the presence/absence of N-terminus. Protein with disordered sequence is homogeneously distributed all over the GUV surface, whereas protein without N-terminus tends to accumulate at the interface between two PI(4)P-containing GUVs. This protein accumulation leads to local overcrowding, which is reflected by slow in-plane diffusion. The effect of N-terminus is also manifested in monomeric OSBPderived proteins that tether ER-like and Golgi-like membranes in the presence of VAP-A. Findings from our in vitro experiments are confirmed in living cells, where N-terminus controls the recruitment of OSBP on Golgi membranes, its motility and the on-and-off dynamics during lipid transfer cycles. Most OSBP-related proteins contain low complexity N-terminal sequences, suggesting a general effect
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Wilhelm, Léa. "Etude du rôle de STARD3 dans le transport du cholestérol." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAJ048/document.
Повний текст джерелаАнотація:
STARD3 est une protéine endosomale de la famille START (Steroidogenic Acute Regulatory (StAR) Related lipid Transfer), qui lie le cholestérol. STARD3 module l’organisation de la cellule en formant des sites de contact membranaire entre les endosomes et le réticulum endoplasmique (RE). Le lien entre les sites de contact membranaire et le transport du cholestérol n’était pas compris. Dans ce travail, nous montrons que STARD3 en interagissant avec les protéines VAPs (VAMP–Associated Proteins) bâtit une machine moléculaire autonome qui transporte le cholestérol au niveau des contacts RE–endosomes. Ce transport permet la formation de membranes internes dans les endosomes et est potentiellement impliqué dans le fonctionnement de ces organites. De plus, nous avons étudié la fonction de STARD3 dans la maladie Niemann Pick type C, qui est caractérisée par une anomalie du transport de cholestérol dans les endosomesSTARD3 is an endosomal sterol-binding protein which belongs to the START protein family. Remarkably, STARD3 modulates the cellular organization by creating membrane contact sites between the endoplasmic reticulum (ER) and endosomes. The link between ER-endosome contact sites and cholesterol transport was not understood. In this work, we showed that STARD3 and its ER–resident partner, VAMP–associated protein (VAP), assemble into a machine that allows a highly efficient transport of cholesterol within ER–endosome contacts. This cholesterol transport provides building blocks for endosome inner membranes formation, and is probably involved in endosome dynamics. Furthermore, we studied STARD3 function in Niemann Pick type C disease, a condition characterized by an impairment of endosomal cholesterol export
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Mahlberg, Florence. "Les Sites membranaires de liaison spécifiques des HDL caractérisation du ligand, aspects fonctionnels /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37607558r.
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Mahlberg, Florence. "Les sites membranaires de liaison specifiques des hdl : caracterisation du ligand, aspects fonctionnels." Paris 7, 1987. http://www.theses.fr/1987PA077223.
Повний текст джерелаАнотація:
Les lipoproteines de haute densite (hdl) jouent un role protecteur contre l'atherosclerose, en partie en captant le cholesterol des tissus peripheriques, est ensuite catabolise dans le foie ou dans les tissus steroidrogenes. L'existence de sites membranaire de liaison specifique des hdl, distincts des recepteurs apob/e et apoe, pourraient etre impliques dans les echanges de cholesterol entre hdl et les tissus hepatiques et peripheriques. Ces sites ne sont pas regules, et leur intervention au niveau des tissus peripheriques dans l'efflux du cholesterol cellulaire en presence de hdl n'est pas limitante
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Abou, Zeid Nancy. "Régulation de la paxilline, un composant majeur des contacts focaux, pendant la migration cellulaire." Paris 6, 2006. http://www.theses.fr/2006PA066228.
Повний текст джерелаАнотація:
Lors de la migration cellulaire nécessite, les contacts focaux, points d'ancrage des cellules à la matrice extracellulaire, constituent des sites particulièrement remaniés. La paxilline en est un des composants protéiques essentiels. Ce travail de thèse a porté sur l’étude de la dégradation de la paxilline pendant la migration cellulaire et de la régulation de ce phénomène par phosphorylation. Nous nous sommes plus particulièrement intéressés aux sérines 188/190, les deux résidus principalement phosphorylés en réponse à l’adhésion cellulaire mais dont la fonction restait à découvrir. Nous avons pu montrer que la paxilline est dégradée par la voie protéasomale et que, lorsque les cellules migrent, la dégradation de la paxilline est retardée. De plus, ce retard de dégradation requiert la phosphorylation des sérines 188/190. Nous avons également pu montrer que la phosphorylation des sérines 188/190 régule l’étalement, la migration cellulaire, et la dynamique des protrusions membranaires.
Книги з теми "Sites de contacts membranaires"
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Kann, Laura. Sexual identity, sex of sexual contacts, and health-risk behaviors among students in grades 9-12: Youth Risk Behavior Surveillance, selected sites, United States, 2001-2009. Atlanta, GA: U.S. Dept. of Health and Human Services, Centers for Disease Control and Prevention, 2011.
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2
Mirrington, Alexander. Transformations of Identity and Society in Anglo-Saxon Essex. NL Amsterdam: Amsterdam University Press, 2019. http://dx.doi.org/10.5117/9789462980341.
Повний текст джерелаАнотація:
Transformations of Identity and Society in Anglo-Saxon Essex: A Case Study of an Early Medieval North Atlantic Community presents the results of a comprehensive archaeological study of early medieval Essex (c.AD 400-1066). This region provides an important case study for examining coastal societies of north-western Europe. Drawing on a wealth of new data, the author demonstrates the profound influence of maritime contacts on changing expressions of cultural affiliation. It is argued that this Continental orientation reflects Essex’s longterm engagement with the emergent, dynamic North Sea network. The wide chronological focus and inclusive dataset enables long-term socio-economic continuity and transformation to be revealed. These include major new insights into the construction of group identity in Essex between the 5th and 11th centuries and the identification of several previously unknown sites of exchange. The presentation also includes the first full archaeological study of Essex under ‘Viking’ rule.
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Geoffrey, Knott, ed. Computing sites: UK company sites, systems and contacts. London: VNU Business Publications, 2003.
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May, Michael W. Personality Marketing: Targeting, Creativity and Performance Basics for Traditional, Owned, and Social Media plus Video Sites and Personal Contacts. Supertext, 2015.
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Jablonka, Peter. Troy in Regional and International Context. Edited by Gregory McMahon and Sharon Steadman. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780195376142.013.0032.
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This article presents an overview of Troy's place in the larger Aegean/Anatolian world, highlighting the continued important role this settlement played over three millennia. From the point of view of archaeology, Hisarlık–Troy ranks high among important sites of the Anatolian and Aegean Bronze Age. Both its Early and Late Bronze Age architecture, the treasures as well as ceramics and other finds reflecting long-distance contacts, the size of the site, its layout comprising a fortified stronghold surrounded by a larger, outlying settlement, and its strategic position clearly show that Troy served as the center of the surrounding region.
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Wesson, Cameron B. America in 1492. Edited by Frederick E. Hoxie. Oxford University Press, 2016. http://dx.doi.org/10.1093/oxfordhb/9780199858897.013.1.
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This chapter examines the nature of Native American societies immediately prior to the advent of sustained contacts with Europeans in the late fifteenth century. Touching on the broad issues of social organization, politics, trade, religion, and identity, the chapter provides a general framework for understanding the uniqueness of indigenous Native American cultures. The precontact Native cultures of North America were far more diverse and complex than any of the theories archaeologists have previously devised to understand them. In addition to the knowledge gained from ever new archaeological investigations of precontact sites in North America, there is ample evidence that an emphasis on scholarly engagement with descendant communities holds the potential to reveal even more about pre- and postcontact Native American experiences.
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Champion, Timothy. Britain before the Romans. Edited by Martin Millett, Louise Revell, and Alison Moore. Oxford University Press, 2015. http://dx.doi.org/10.1093/oxfordhb/9780199697731.013.010.
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Much of Britain saw significant changes in the later part of the first millennium bc, particularly in the south-east. Widespread but regionally varied changes in settlement organization resulted in the emergence of new types of sites, some of which have been termed oppida. Changes included the reappearance of gold, the adoption of wheel-turned pottery, new styles of clothes fastening, and cremation burial from Late La Tène Gaul. The burial tradition included a small number of richly furnished burials. Imports of Roman origin were transmitted through Gaulish intermediaries. After Caesar’s expeditions to Britain, the influence of Rome was much more marked and imports increased. Contacts between Britain and Rome may have included formal recognition of some rulers as client kings. Evidence suggests a limited knowledge of literacy and Latin, but the cultural significance of many Roman objects is often unclear.
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Heiner, Prof, Bielefeldt, Ghanea Nazila, Dr, and Wiener Michael, Dr. Part 1 Freedom of Religion or Belief, 1.3.9 Communicate with Individuals and Communities on Religious Matters at the National and International Level. Oxford University Press, 2016. http://dx.doi.org/10.1093/law/9780198703983.003.0014.
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This chapter focuses on issues concerning the right to communicate on religious matters at the national and international level. Such communications not only encompass transmitting and receiving verbal or written religious messages, but also personal contacts, processions, and pilgrimages. At the domestic level, processions or parades may provoke violent clashes and public order problems, often leading the State authorities to ban or restrict such processions. Meanwhile, at the international level, religious communities and their pilgrimage sites are usually not confined to the territory of only one State, which naturally leads to the need for international communications and pilgrimages. This situation illustrates the overlap of the right to communicate in matters of religion also with the rights to disseminate publications and to teach a religion or belief. Issues of interpretation include the questions whether communications are also covered by this freedom if they are made for proselytizing purposes or if they involve transfrontier travels in order to attend a religious meeting or undertake a pilgrimage.
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Bartie, Susan, and David Sandomierski, eds. American Legal Education Abroad. NYU Press, 2021. http://dx.doi.org/10.18574/nyu/9781479803583.001.0001.
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Throughout the twentieth century, elite US law schools have been presented as sites of power, admiration, influence and envy. Robert Stevens, in the opening of his seminal 1983 work Law School, suggested that foreign lawyers looked wistfully at elite US law schools. At a time when US political institutions—and even law schools—seem to have lost much of their former global luster, this book investigates whether in reality the elite US models ever proved so attractive to foreigners. Collectively the contributions cast doubt on traditional narratives that point toward the globalization or homogenization of legal education. They challenge the idea that many educators beyond the United States believed that the adoption of American models would lead to better legal education and scholarship, better legal systems, better lawyers, and better governance. And they illuminate the cultural and political significance of attempts to transplant US models. The book consists of historical examinations of American contacts within legal education in fourteen countries: China, Japan, Israel, the Philippines, Nigeria, Kenya, Ghana, France, Brazil, Sweden, Estonia, England, Australia, and Canada. And it includes critical commentary from two leading American law professors, along with a founding chapter from Bruce Kimball, the leading historian of Harvard Law School.
Частини книг з теми "Sites de contacts membranaires"
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Varfolomeyev, S. D., and A. J. Yaropolov. "Electric “Contacts” between Conductors and Protein Active Sites." In From Neural Networks and Biomolecular Engineering to Bioelectronics, 121–33. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4899-1088-2_12.
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Codina, Ferran, Aurora Martin, and Gabriel de Prado. "Les imitations de céramique coloniale des sites ibériques d’Ullastret (Catalogne)." In Contacts et acculturations en Méditerranée occidentale, 377–84. Publications du Centre Camille Jullian, 2015. http://dx.doi.org/10.4000/books.pccj.5011.
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Zammar, Nisrine. "Social Network Sites." In Social Influences on Information and Communication Technology Innovations, 107–16. IGI Global, 2012. http://dx.doi.org/10.4018/978-1-4666-1559-5.ch007.
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This article examines the role of actors in a Social Network Sites and also the triggers and challenges they represent to social networking between today’s communities and businesses. A Social Network Sites is the product of the evolution of social liaisons and the emergence of online communities of people who are interested in exploring the concerns and activities of others. A social network is the assembly of direct or indirect contacts; a network is the product of interactions with the actors (individuals, families, enterprises, etc.) enabled by means of the structural design of web 2.0. Social Network Sites bring people together to interact through chat rooms, and share personal information and ideas around any topics via personal homepage publishing tools. This article is intended to be a trigger to deeply and more intensely explore potential roles of actor-network theory in the Social Network Sites context, in today’s and tomorrow’s world.
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Jeter, Marvin D., Robert J. Scott, and John H. House. "Possible Cahokian Contacts in Eastern and Southeastern Arkansas." In Cahokia in Context, 185–204. University Press of Florida, 2020. http://dx.doi.org/10.5744/florida/9781683400820.003.0008.
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Most discussions of Cahokian “contact” and “influence” in the Lower Mississippi Valley have focused on a “horizon” around 1200 AD and sites east of the Mississippi River; another site was documented recently in northeastern Louisiana. Here, we present additional westerly evidence from sites in eastern and southeastern Arkansas that have produced: Missouri Flint Clay figurines; flakes resembling Burlington and Crescent Quarry cherts; hoes, polished “hoe chips,” and other items made of Mill Creek chert; plus a few Cahokia-style chunkey stones and a Cahokia arrow point, but as yet no Cahokian ceramics. These items tend to cluster at and near three mound sites, in contexts around 1200 AD, with hints of a southward time trend. Unlike the few “elite” or sacred figurines found in mounds, most other items are utilitarian and may have been recirculated (rather than chiefly-redistributed) via “trade fairs” at mound centers, to commoners from the hinterlands.
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Nunez-Zabaleta, Aitziber, Elena Olabarri, and Sergio Monge-Benito. "Getting New Business Contacts in Foreign Markets through Social Networking Sites." In Analyzing the Strategic Role of Social Networking in Firm Growth and Productivity, 334–51. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0559-4.ch018.
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Being able to find information, people and expertise helps business to grow and remain competitive. Professional networking using the web 2.0 is providing entry opportunities into international markets, allowing professional workers to interact with both workers and companies in markets worldwide. For that reason our research seeks identify the Social Networking Sites (SNSs) used with business purposes by professional workers, as well as to test the importance given by workers of the Basque Country region in Spain, to the use of social networks, particularly SNSs, to find new professionals around the world and help the workers network. Business Networking is a valuable way to expand knowledge, learn from the success of others, attain new clients and tell others about the business.
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"Information Sources: Private Foundation and Government Web Sites, and Study Section Contacts." In Research Proposals, 297–310. Elsevier, 2002. http://dx.doi.org/10.1016/b978-012524733-7/50030-8.
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"Les Contacts Entre la Cote Sud de la Baltique et Rome a L’epoque de Neron." In Les Sites archéologiques en Crimée et au Caucase durant l'Antiquité tardive et le haut Moyen-Age, 29–35. BRILL, 2000. http://dx.doi.org/10.1163/9789004502628_006.
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Fant, Clyde E., and Mitchell G. Reddish. "Miletus." In A Guide to Biblical Sites in Greece and Turkey. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195139174.003.0038.
Повний текст джерелаАнотація:
Originally famed for its philosophers of nature, Miletus became one of the great cities of commerce of the ancient world. Its four harbors and strategic location on the west coast of Asia Minor gave the city unique advantages as a vital port in both peace and war. Yet these factors also were the cause of repeated periods of invasion and destruction. Eventually Miletus ceased to be a major player in world affairs, not because of the fortunes of war, but because of the slower but deadlier effects of the gentle Meander River, which silted its harbors and created malaria-ridden marshes. Miletus is easily reached from Izmir by taking E87 south to Selçuk, then proceeding on highway 525 through Söke to Akköy, then north through Balat to the site of Miletus. Today it is difficult to imagine that Miletus once was situated on a narrow peninsula and boasted of four harbors, three on the west and one on the east. Due to the continual silting effects of the Meander River, the ruins of Miletus now are situated in a broad plain some 5 miles from the sea. The island of Lade, where the Persian armada burned and destroyed the Ionian fleet in 494 B.C.E., was once to the west of the coast of Miletus. Now it is merely a hill 4 miles west of Miletus. A Mycenaean colony that had cultural contacts with Crete and Greece existed in this location from 1400 B.C.E. Greeks settled in the area by at least the 10th century B.C.E. The city prospered and grew wealthy from its colonies on the Mediterranean, the Black Sea, and even in Egypt. It was one of the first cities in the ancient world to mint coins. Soon Miletus became the most important of the twelve cities of the region of Ionia. The city came under Persian control in 546 B.C.E. and later opposed them in the Battle of Lade, but the result was the loss of their fleet and the complete destruction of their city in 494 B.C.E. Herodotus, in fact, said that Miletus was reduced to slavery. Subsequently, Ephesus surpassed Miletus as the first city of the region.
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Coverdill, James E., and William Finlay. "Evolution or Revolution?" In High Tech and High Touch. Cornell University Press, 2017. http://dx.doi.org/10.7591/cornell/9781501702808.003.0005.
Повний текст джерелаАнотація:
This chapter considers how information technology and social media have shaped headhunting. It develops in three sections, the first focusing on how social media such as LinkedIn have made it easier to source candidates, the second showing that these sites are far more valuable for extensive search (finding prospects) than for intensive search (turning prospects into candidates), and third discussing new technologies, such as electronic portals and online marketplaces, that seek to centralize and rationalize contacts between headhunters and clients. The chapter argues that portals and marketplaces distance headhunters from hiring managers and discourage thorough candidate searches; it suggests that practices designed to promote efficiency in recruiting may actually undermine effective recruiting
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Townsend, Peter. "Small anomalies and long-range consequences." In The Power of Imperfections, 191–202. Oxford University Press, 2022. http://dx.doi.org/10.1093/oso/9780192857477.003.0012.
Повний текст джерелаАнотація:
Even with children’s building blocks one can make an intuitive first guess at the structure of localized imperfections. However, experimentally designing, identifying, characterizing and controlling them is far more difficult. One reason is that many defect sites have extremely long-range consequences and, in these cases, intuition is hard. Nevertheless, the need to do this and predicting the potential benefits are significant. Long-range effects uses are not just for semiconductors, but apply equally to radiation dosimetry, archaeological dating, information storage, plus chemical and biological reactivity. One can gain intuition by considering human interactions and how our lives are defined, not just by immediate contacts, but by political, social, legislative and factors that control the flow of goods and information across the globe.
Тези доповідей конференцій з теми "Sites de contacts membranaires"
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Li, Sheng, Ahmet Kahraman, and Mark Klein. "A Fatigue Model for Spur Gear Contacts Operating Under Mixed Elastohydrodynamic Lubrication Conditions." In ASME 2011 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/detc2011-47287.
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This paper presents a model to predict the crack formation fatigue lives of spur gear contacts operating under mixed lubrication conditions where surface roughnesses introduce intermittent metal-to-metal contacts and severe stress concentrations. The proposed model consists of several submodels including (i) a gear load distribution model to determine the normal tooth force distribution along the tooth profile, incorporating any profile modifications and manufacturing deviations, (ii) a mixed elastohydrodynamic lubrication model customized to handle transient contact conditions of gears, (iii) a stress formulation that assumes the plane strain condition to compute the transient elastic stress fields on and below the tooth surface induced by the mixed lubrication surface pressure and shear stress distributions, and (iv) a multi-axial fatigue model to predict the crack nucleation life distribution. The proposed spur gear fatigue model is used to simulate the contacts of gear pairs having different surface roughness amplitudes. The predictions are compared to the measured gear fatigue Stress-Life data for each surface condition to assess the model accuracy in predicting the crack nucleation fatigue lives as well as the location of the critical failure sites.
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Kobeleva, L. "International contacts of the Andronov (Fedorovo) and aboriginal populations of forest-steppe Baraba through the evidence of the burial rite." In Archaeological sites of Southern Siberia and Central Asia: from the appearance of the first herders to the epoch of the establishment of state formations. Institute for the History of Material Culture of the Russian Academy of Sciences, 2021. http://dx.doi.org/10.31600/978-5-907298-16-3.78-80.
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Hijikata-Okunomiya, A., S. Okamoto, R. Kikumoto, and Y. Tamao. "STEREOGEOMETRY OP THE ACTIVE SITES OF SERINE ENZYMES GATHERED FROM SYNTHETIC THROMBIN-INHIBITORS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644606.
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MD-805 is a potent thrombin-inhibitor having the structure of tri-pods; Arg skeletone, N-terminal side and C-terminal side. MD-805 showed weaker inhibitory activity to other enzymes than thrombin. In this report, to gather more detailed informations about the structural features of serine enzymes concerning the specificity, we experimentally examined the structure-activity relationship (SAR) of a number of arginine derivatives including MD-805 and theoretically generated a MD-805-trypsin complex model using the results of X-ray crystallography of MD-805 and BPTI-trypsin complex by calculation in principle to minimize van der Waals contacts, and thus we discussed to interpret SAR from the molecular level. SAR of C-terminal side of arginine derivatives was obtained with the inhibitory activity to trypsin, plasmin, and glandular kallikrein and compared with the previous results of thrombin, the followings being indicated: (1) The hydrophobic binding pocket (HBP), which was reported by us to be at least partly similar in stereogeometry between trypsin and thrombin, had the depth corresponded to the length of ethylpiperidine, (2) concerning the site (termed the P site) next to HBP, there were large differences in stereogeometry between trypsin and thrombin; the P site of trypsin could accept propyl and phenyl group attached to 4-position of piperidine, while that of thrombin was unable to accept them and (3) the P sites of plasmin and glandular kallikrein resembled that of trypsin in being able to accept phenyl group. MD-805-trypsin complex model supported the reasonable understanding that the stereogeometrical similarity in HBP between thrombin and trypsin was attributable to the high homology in amino acid sequences in Ser-195 loop and that the dissimilarity in the P sites between thrombin and the others was attributable to 9 amino acids insertion found only in thrombin (Loop B). Furthermore, many dansylarginine derivatives showed very strong inhibition for pseudocholinesterase, however, SAR for C-terminal side of these derivatives revealed the similarity and dissimilarity in HBP and the P site between pseudocholinesterase and the proteases described above.
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Widener, E., S. Tatti, P. Schani, S. Crown, B. Dunnigan, J. Moss, C. M. Chan та ін. "Burn-in Failure Analysis of 0.5μm 1MB SRAM: Barrier Glue Layer Cracks and Tungsten Plug “Worm Holes”". У ISTFA 1996. ASM International, 1996. http://dx.doi.org/10.31399/asm.cp.istfa1996p0159.
Повний текст джерелаАнотація:
Abstract A new 0.5 um 1 Megabit SRAM which employed a double metal, triple poly CMOS process with Tungsten plug metal to poly /silicon contacts was introduced. During burn-in of this product, high currents, apparently due to electrical overstress, were experienced. Electrical analysis showed abnormal supply current characteristics at high voltages. Failure analysis identified the sites of the high currents of the bum-in rejects and discovered cracks in the glue layer prior to Tungsten deposition as the root cause of the failure. The glue layer cracks allowed a reaction with the poly/silicon, causing opens at the bottom of contacts. These floating nodes caused high currents and often latch-up during burn-in. Designed experiments in the wafer fab identified an improved glue layer process, which has been implemented. The new process shows improvement in burn in performance as well as outgoing product quality.
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Wilkerson, Patrick W., Andrzej J. Przekwas, and Chung-Lung Chen. "Multiphysics Design and Analysis Simulations for Power Electronic Device Wirebonds." In ASME 2003 International Electronic Packaging Technical Conference and Exhibition. ASMEDC, 2003. http://dx.doi.org/10.1115/ipack2003-35170.
Повний текст джерелаАнотація:
Multiscale multiphysics simulations were performed to analyze wirebonds for power electronic devices. Modern power-electronic devices can be subjected to extreme electrical and thermal conditions. Fully coupled electro-thermo-mechanical simulations were performed utilizing CFDRC’s CFD-ACE+ multiphysics simulation software and scripting capabilities. Use of such integrated multiscale multiphysics simulation and design tools in the design process can cut cost, shorten product development cycle time, and result in optimal designs. The parametrically designed multiscale multiphysics simulations performed allowed for a streamlined parametric analysis of the electrical, thermal, and mechanical effects on the wirebond geometry, bonding sites and power electronic device geometry. Multiscale analysis allowed for full device thermo-mechanical analysis as well as detailed analysis of wirebond structures. The multiscale simulations were parametrically scripted allowing for parametric simulations of the device and wirebond geometry as well as all other simulation variables. Analysis of heat dissipation from heat generated in the power-electronic device and through Joule heating were analyzed. The multiphysics analysis allowed for investigation of the location and magnitude of stress concentrations in the wirebond and device. These stress concentrations are not only investigated for the deformed wirebond itself, but additionally at the wirebond bonding sites and contacts. Changes in the wirebond geometry and bonding geometry, easily changed through the parametrically designed simulation scripts, allows for investigation of various wirebond geometries and operating conditions.
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Hunziker, E. B., P. W. Straub, and A. Haeberli. "AN INTERLOCKING SINGLE-STRAND MODEL FOR FIBRIN POLYMERIZATION." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643315.
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The early stages of fibrin polymerization were investigated by rotatory shadowing and electron microscopy. Individual molecules within initial oligomers were found to be unaligned and contacted neighbouring molecules by single E + D and D + E contacts, suggesting an intermediate phase of activation (des A-fibrin). The interacting molecular domains were separated by a distance of 2 to 3 nm, indicating that (both or at least one) binding sites are located on protruding segments of the polypeptide chains. Upon completion of fibrin activation (des AA-fibrin), molecules within the early oligomers aligned to form single-stranded polymers,o these being characterized by repeating trinodular units of 230 A in length. Based upon these findings, a new interlocking single-stranded model for fibrin polymerization was designed and tested. The model is consistent with previous experimental data on fibrin polymerization such as that obtained by X-ray diffraction and negative staining. Moreover, early branching and lateral association phenomena are easily explained.
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Kodali, Satish, Chen Zhe, and Chong Khiam Oh. "Nanoprobe Characterization of Soft SRAM bit Fails in Advanced Technologies." In ISTFA 2019. ASM International, 2019. http://dx.doi.org/10.31399/asm.cp.istfa2019p0273.
Повний текст джерелаАнотація:
Abstract Nanoprobing is one of the key characterization techniques for soft defect localization in SRAM. DC transistor performance metrics could be used to identify the root cause of the fail mode. One such case report where nanoprobing was applied to a wafer impacted by significant SRAM yield loss is presented in this paper where standard FIB cross-section on hard fail sites and top down delayered inspection did not reveal any obvious defects. The authors performed nanoprobing DC characterization measurements followed by capacitance-voltage (CV) measurements. Two probe CV measurement was then performed between the gate and drain of the device with source and bulk floating. The authors identified valuable process marginality at the gate to lightly doped drain overlap region. Physical characterization on an inline split wafer identified residual deposits on the BL contacts potentially blocking the implant. Enhanced cleans for resist removal was implemented as a fix for the fail mode.
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Reznikov, Lev. "Integrated Eco-Thermal Management for Aerospace." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-82865.
Повний текст джерелаАнотація:
Thermal Management System developed for aerospace carriers (missile, aircraft, space station), bounds processes of generation and dissipation, transfer and conversion of power, refrigeration, and of bio-metabolism related substances. Local ecosystem of the carrier combines technological and biological subsystems, interacting with internal and outer spaces. The conceptual IETM System performs recovery of waste thermal energy, generation of “free” refrigeration, and recovery of byproducts into safe coolants (ammonia - water). Thermal Management solutions include novel technologies of intensification of the heat transfer and of conversion of the waste resources into refrigeration for extension of cooling capabilities for high heat radars, lasers and microwave generators. The IETM includes Vacuum-Evaporative Refrigeration (VER) utilizing “free natural” vacuum and waste heat-activated refrigeration circuits. VER generates ~1000 Btu of “free” cold per pound of wastewater or ammonia. The introduced high performance microstructure of compound electrohydrodynamic (EHD) boundary microsystems intensifies nucleate boiling, preventing dryout. The coils of the microwires adjoin to the boiling surface and form precision microstructure of heat sink with microchannels between the coils and the surface. The microcavities form the active bubbling nucleation sites along the spiral zones of contacts of the microwires and basic surfaces. The fins-microelectrodes develop additional heat transfer surface and evenly distributed spiral zones of the nucleation sites. Like fibers of a fine wick, the electric forces in EHD capillary structures of the microelectrodes retain the liquid and push out generated vapor bubbles from the surface. Good manufacturability and performance of novel MEMS are based on well-developed materials and common winding technology “borrowed” from electrotechnical industry. Conversion of waste resources into refrigeration and EHD activation of boiling allow meeting strong limitations in weight, reliability and consumption of energy. These conceptual approaches provide diversities in refrigeration capabilities for IETM.
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Chen, Kuo Hsiung, Chih-Chung Chang, and Jian Chan Lin. "Failure Localization by Using a Novel Backside Passive Voltage Contrast Methodology." In ISTFA 2011. ASM International, 2011. http://dx.doi.org/10.31399/asm.cp.istfa2011p0396.
Повний текст джерелаАнотація:
Abstract Contact resistance from wafer acceptance test (WAT) data is one of the critical parameter to significantly affect fabrication process. While WAT data shows open/short fail, high resistance fail and leakage fail in contact chain structure, the first job in failure analysis (FA) field is to localize failure site. For example, High resistance failure and leakage failure sites can be localized by Infrared Ray Optical Beam Induced Resistance Change (IR-OBIRCH) detection. Most of open failure modes could be isolated by front side passive voltage contrast (PVC) technique. However, there is still a limitation to this technique while contacts are still connected to substrate in metal-1/contact/active chain structure. Active Voltage Contrast (AVC) [1, 2] is a good method to overcome this problem, but the major concern is how to mark the failure location in SEM based probing system. In this paper, we provide a novel backside passive voltage contrast method to improve the failure analysis technique. By thinning down silicon substrate to the active area, a new contact chain from active area is created. Therefore, novel backside PVC is applied to locate the failed site.
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Abrate, Serge, Jefferson F. Lindsey, Alan Weston, Jon Rivers, and William Dill. "Advanced Technological Pre-College Education Program in Composite Manufacturing." In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0636.
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Abstract This article describes a National Science Foundation sponsored project to promote technological education with a focus on composites manufacturing. This project has four components: (1)the promotion of careers in Technology to students in grades 7–11; (2) summer camps for students grades 7–11; (3) short courses for high school teachers; (4) developing new courses at the undergraduate level. For each component of the project, a rationale, detailed content, delivery methods, and assessment methods will be discussed. Experience indicates a need to reach secondary school students to make them aware of careers in Technology and related educational opportunities at two-year and four-year institutions and to present a positive and attractive image of the field. Our efforts are directed towards students in grades 7–11. To reach a maximum of students in a large geographic area using several approaches: 1. Presentations using distance learning facilities that allow interactive audio/video presentations at different sites. Faculty members on campus can communicate with six or more sites simultaneously and present computer-based materials, videos, and conduct live demonstrations. 2. School visits. Many schools do not have access to site for interactive video presentations. 3. A web site developed for the project contains regularly updated information about the project, information about composite materials, and the field of technology. Interested parties can register for various programs by filling out the appropriate forms on the web. 4. Special events such as National Engineers Week and Open House Days are used to establish personal contacts. This paper describes how the presentations are delivered, their contents, and how effective they are in promoting a positive image of technology. Another important component of this project is that each institution offers summer camps for students in grades 7–11 and short courses for high school teachers. Each of these activities concentrate on one specific technical area and offer both a general view of that area and how it can lead to rewarding careers in industry, and direct hands-on experiences.
Звіти організацій з теми "Sites de contacts membranaires"
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Sprague, Joshua, David Kushner, James Grunden, Jamie McClain, Benjamin Grime, and Cullen Molitor. Channel Islands National Park Kelp Forest Monitoring Program: Annual report 2014. National Park Service, August 2022. http://dx.doi.org/10.36967/2293855.
Повний текст джерелаАнотація:
Channel Islands National Park (CHIS) has conducted long-term ecological monitoring of the kelp forests around San Miguel, Santa Rosa, Santa Cruz, Anacapa and Santa Barbara Islands since 1982. The original permanent transects were established at 16 sites between 1981 and 1986 with the first sampling beginning in 1982, this being the 33rd year of monitoring. An additional site, Miracle Mile, was established at San Miguel Island in 2001 by a commercial fisherman with assistance from the park. Miracle Mile was partially monitored from 2002 to 2004, and then fully monitored (using all KFM protocols) since 2005. In 2005, 16 additional permanent sites were established to collect baseline data from inside and adjacent to four marine reserves that were established in 2003. Sampling results from all 33 sites mentioned above are included in this report. Funding for the Kelp Forest Monitoring Program (KFM) in 2014 was provided by the National Park Service (NPS). The 2014 monitoring efforts utilized 49 days of vessel time to conduct 1,040 dives for a total of 1,059 hours of bottom time. Population dynamics of a select list of 71 “indicator species” (consisting of taxa or categories of algae, fish, and invertebrates) were measured at the 33 permanent sites. In addition, population dynamics were measured for all additional species of fish observed at the sites during the roving diver fish count. Survey techniques follow the CHIS Kelp Forest Monitoring Protocol Handbook (Davis et al. 1997) and an update to the sampling protocol handbook currently being developed (Kushner and Sprague, in progress). The techniques utilize SCUBA and surface-supplied-air to conduct the following monitoring protocols: 1 m2 quadrats, 5 m2 quadrats, band transects, random point contacts, fish transects, roving diver fish counts, video transects, size frequency measurements, and artificial recruitment modules. Hourly temperature data were collected using remote temperature loggers at 32 sites, the exception being Miracle Mile where there is no temperature logger installed. This annual report contains a brief description of each site including any notable observations or anomalies, a summary of methods used, and monitoring results for 2014. All the data collected during 2014 can be found in the appendices and in an Excel workbook on the NPS Integrated Resource Management Applications (IRMA) portal. In the 2013 annual report (Sprague et al. 2020) several changes were made to the appendices. Previously, annual report density and percent cover data tables only included the current year’s data. Now, density and percent cover data are presented in graphical format and include all years of available monitoring data. Roving diver fish count (RDFC), fish size frequency, natural habitat size frequency, and Artificial Recruitment Module (ARM) size frequency data are now stored on IRMA at https://irma.nps.gov/DataStore/Reference/Profile/2259651. The temperature data graphs in Appendix L include the same graphs that were used in past reports, but include additional violin plot sections that compare monthly means from the current year to past years. In addition to the changes listed above, the layout of the discussion section was reordered by species instead of by site. The status of kelp forests differed among the five park islands. This is a result of a combination of factors including but not limited to, oceanography, biogeography and associated differences in species abundance and composition, as well as sport and commercial fishing pressure. All 33 permanent sites were established in areas that had or were historically known to have had kelp forests in the past. In 2014, 15 of the 33 sites monitored were characterized as developing kelp forest, kelp forest or mature kelp forest. In addition, three sites were in a state of transition. Two sites were part kelp forest and part dominated by Strongylocentrotus purpuratus...
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Greinert, Jens. Mine Monitoring in the German Baltic Sea 2020; Dumped munition monitoring AL548, 03rd – 16th November 2020, Kiel (Germany) – Kiel (Germany) „MineMoni-II 2020“. GEOMAR Helmholtz Centre for Ocean Research Kiel, 2021. http://dx.doi.org/10.3289/cr_al548.
Повний текст джерелаАнотація:
ALKOR cruise AL548 took place as part of the EMFF (European Maritime and Fisheries Fund)-funded project BASTA (Boost Applied munition detection through Smart data inTegration and AI workflows; https://www.basta-munition.eu) and as continuation of the munition monitoring started within the BMBF-funded project UDEMM (Environmental Monitoring for the Delaboration of Munition in the Sea; https://udemm.geomar.de/). In October 2018, a first cruise (POS530 MineMoni2018) was conducted, to gather data for a broad baseline study in the German Baltic Sea. Results show a moderate contamination level on regional and coastal scale, but indicate higher levels for specific local areas. Within UDEMM, expertise was developed to detect, exactly locate and monitor munition (e.g. torpedoes, sea mines, ground mines) on the seafloor using optical and hydroacoustic means. In addition, chemical analyses of dissolved contaminants in the water and sediments was performed. Data acquired during this cruise are used in BASTA, which aims for enhanced munition detection via AUV-based artificial intelligence applied on multi-sensor datasets. At the same time, the project ExPloTect (Ex-situ, near-real-time exPlosive compound deTection in seawater) (also EMFF-funded) addresses the need for an innovative approach to detect explosive compounds in seawater. A prototype system was used and successfully tested for the first time during this cruise. The main focus was placed onto the two already known dumpsites Kolberger Heide and Lübeck Bight. Additionally, new areas Falshöft (Schleswig-Holstein) and Cadet Channel, Trollegrund and Großklützhöved (Mecklenburg-Vorpommern) were explored. In each area high-resolution multibeam mapping was performed and contact lists, indicating potential munition objects were produced on board. AUV surveys were conducted to ground-truth possible contacts via detailed photograph and magnetometer mapping. This was complemented with towed video (TV)-CTD profiles. The transits to and between those sites were planned along former constraint routes during WWII. These routes were main targets of the British Air Force and mines and bombs can be expected along these ways. During transits water samples were taken with on a CTD- (conductivity, temperature, depth) rosette-mounted Niskin bottles in regular distances, in order to obtain a comprehensive understanding munition compounds (inter alia trinitrotoluene (TNT)) measurements across the German Baltic Sea.