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ROMERO, SERGIO A. "Producao e caracterizacao de filmes finos de SmCo." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10915.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Derkaoui, Souad. "Effet de Cu et Zr sur les caractéristiques métallurgiques et magnétiques des alliages à base de SmCo et SmCo pour aimants permanents." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37604469d.
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Hedges, Samuel Carter. "Odd-triplet superconductivity in SmCo/Py exchange spring based Josephson junctions." Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1598639.
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Exchange spring based superconducting heterostructures and Josephson junctions are studied to search for evidence of odd-triplet superconductivity. Cooper pairs from a superconductor can leak into a nonhomogeneous ferromagnet a much greater distance than they leak into a homogeneous ferromagnet. This is a result of a conversion of the superconducting condensate at the superconductor-nonhomogeneous ferromagnet interface from the singlet and triplet states to the odd-triplet state. The odd-triplet state is insensitive to the exchange field of the ferromagnet.
To generate the nonhomogeneous magnetic region, an exchange spring is used. The exchange spring consists of coupled hard and soft magnetic layers that are used to produce a nonhomogeneous magnetization. The system studied consists of superconducting Niobium (Nb) and a Samarium-Cobalt/Permalloy (SmCo/Py) exchange spring.
Initial samples of Niobium had a critical temperature lower than that obtainable in our laboratory (< 1.8 K). Preliminary work was done to find the cause of the suppressed critical temperature of Nb and to increase it. This work resulted in obtaining Niobium thin films with critical temperatures as high as 6 K.
Indirect evidence of the odd-triplet component is searched for by looking at the critical temperature of superconductor/exchange spring bi-layers. As the nonhomogeneity of the magnetization is increased, it is expected that the critical temperature will decrease as the condensate leaks further into the exchange spring. In Nb/Py/SmCo systems, this behavior was observed, along with a modulation in the resistance that is attributed to the anisotropic magnetoresistance of the permalloy layer. A decrease in the critical temperature with increasing nonhomogeneity of the exchange spring was also observed in Nb/SmCo/Py layers, provided the SmCo layer is not too thick.
Direct evidence of the odd-triplet component is searched for by looking at the modulation of the critical current through exchange spring based Josephson junctions as exchange spring magnetization becomes more nonhomogeneous. As the nonhomogeneity of the magnetization increases, the critical current through the junction should increase as well. Fabrication of Josephson junctions with exchange spring interlayers was performed at Oak Ridge National Laboratory, and the procedure is presented here. The critical current through these junctions was observed to increase with increasing nonhomogeneity of the exchange spring magnetization, although more tests are needed to verify this is due to the odd-triplet component of the superconducting condensate.
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Qadeer, Muhammad Irfan. "SmCo for polymer bonded magnets : Corrosion, silanization, rheological, mechanical and magnetic properties." Doctoral thesis, KTH, Keramteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-106809.
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This thesis presents the study of organofunctional alkoxysilane coatings to prevent high temperature oxidation of Sm-Co powders. Sm-Co are important permanent magnetic alloys, owing to their high Curie temperature and large values of magnetocrystalline anisotropy. They possess stable magnetic properties in the temperature range -40 to 120 °C which makes them very attractive candidates for automobile’s electric motors. However, the environmental conditions for such applications are a sum of high temperatures, humidity, fuels and salts which provide perfect breeding ground for corrosion. In this study we report the high temperature oxidation resistance of Sm2Co17 powders coated with four common commercially available organofunctional silanes; (3-aminopropyl)trimethoxysilane (APTMS), (3-aminopropyl)triethoxysilane (APTES), methyltrimethoxysilane (MTMS) and (3-glycidyloxypropyl)trimethoxysilane (GPTMS). The as received powder was a multimodal mixture of many sizes and shapes which represented a typical ball milling product. The thermal analyses of the powders suggested that the powders without surface coatings had profound affinity towards oxidation. The thermal properties of sieved uncoated powders revealed that the small powders were more susceptible to oxidation than the large powders due to their large specific surface area. The isothermal properties of coated powders revealed that the powders coated with silanes had at least 10 times higher resistance to oxidation as compared to uncoated powders heated at 400 °C for 10 h. The non-isothermal tests conducted from room temperature to 500 °C also revealed that the uncoated powders gained 6 times more mass as compared to the powders coated with an ideal (MTMS) silane. The microstructural analysis of the uncoated powders heated from 400 °C to 550 °C revealed diffusion of oxygen, instable intermetallic phases which resulted in a redistribution of alloying elements, precipitation of alloying elements and formation of a featureless shell (approximately 20 µm in thickness) that surrounded the unreacted core. The coated powders on the other hand showed homogenous distribution of alloying elements, stable intermetallic phases and limited the shell thickness (1 µm). The thermo-magnetic properties of Sm-Co powders showed that the thermal instability also affected the magnetic properties adversely. It was found that the magnetic properties were deteriorated with a decrease in powder size. The energy dispersive spectroscopic (EDS) analyses showed that the small powders contained higher oxygen content than the large powders. Moreover XRD analysis also revealed that the small powders contain higher residual strains and smaller crystallite size which can play their role in deteriorating magnetic properties. It was found that surface modification by silanization improve the thermo-magnetic properties by effectively shielding the powder surfaces from surface oxidation. The rheological properties Sm-Co/PA12 composites revealed that the viscosity of the composites was increased with decreasing powder size due to the presence of rough surfaces and sharp corners in small powders. The rheological properties of the melts containing coated powders revealed that the silane layer acted as a lubricant and decreased the melt viscosity. It was found that coating the powders with silanes not only improve the rheological properties but also improve the other physical properties such as glass transition temperature the loss modulus by modifying the interfacial layer between the polymer matrix (PA12) and the powder. It results in a decrease in viscosity, a broadening of the glass transition temperature and a change in the damping properties of the composites. The dynamic mechanical properties of Sm-Co/PA12 composites showed that the storage modulus was increased with decreasing powder size. The results were expected as the rough surfaces act as local welding points between the powder and the polymer matrix. It was found that the surface modification improve the storage modulus. It is assumed that the silanes modify the interfacial properties which not only resulted in increasing the storage modulus but also broadened the glass transition temperature, Tg and damping, tanδ peaks. From the thermogravimetric, microstructural, rheological and magnetic analyses it can be concluded that the silanes are the effective coatings in preventing high temperature oxidation, stabilizing microstructure, enhancing mechanical properties, and improving rheological and magnetic properties.QC 20121205
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Roos, Andreas. "Growth and characterization of advanced layered thin film structures : Amorphous SmCo thin film alloys." Thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-177674.
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This report describes the growth and characterization of thin amorphous samarium-cobalt alloy films. The samarium-cobalt alloy was grown by DC magnetron sputtering in the presence of an external magnetic field parallel to the thin film. The external magnetic field induces a uniaxial in-plane magnetic anisotropy in the samarium-cobalt alloy. The thin films were characterized with x-ray scattering, and the magnetic anisotropy was characterized with the magneto optic Kerr effect. The measurements showed a uniaxial in-plane magnetic anisotropy in the samarium-cobalt alloy films. It is not clear how amorphous the samples really are, but there are indications of crystalline and amorphous areas in the alloys.
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Chouarbi, Katia. "Micromoulage de films épais de Sm-Co." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00912904.
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Cette étude a été motivée par les nombreux avantages du procédé de micromoulage, qui couple la croissance électrolytique et la localisation du film avec un moule en résine épaisse. Ce procédé permet en effet la réalisation de micro-objets, dont les dimensions sont uniquement dépendantes de la résolution des techniques de lithographie employées pour définir les moules en résine. Le micromoulage permet donc de réaliser des microstructures métalliques et est compatible avec la technologie MEMS. Nous avons mis en évidence l'influence de différents paramètres expérimentaux dans le cadre de l'étude de la croissance électrolytique du samarium-cobalt en solution aqueuse dans une cellule de Hull. Cette étude nous a permis de déterminer plusieurs points de fonctionnement conduisant à des teneurs en samarium et des épaisseurs élevées : jusqu'à 50 % de samarium et plusieurs microns d'épaisseur. En outre, un certain nombre d'hypothèse ont été émises, qui lient le procédé d'élaboration et le mécanisme de croissance. Nous avons aussi réussi a montré qu'il est possible de réaliser des micromotifs de plusieurs microns d'épaisseur contenant un rapport Sm/(Sm+Co) relativement élevé (10 %) et une faible contamination en oxygène (8 %).
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Schmidt, Frank. "Die Bedeutung der Segregations- und Oxidationsneigung Seltener Erden für die Einstellung hartmagnetischer intermetallischer Phasen in SmCo-basierten Nanopartikeln." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-234251.
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Aufgrund der sehr hohen magnetokristallinen Anisotropiekonstante eignet sich besonders die Phase SmCo5 für zukünftige Festplattenmedien mit hoher Speicherdichte. Durch die starke Oxidationsneigung und die gegebene chemischen Ähnlichkeit anderer Seltenen Erden ist es eine Herausforderung hartmagnetische SmCo-basierte Nanopartikel mittels Inertgaskondensation herzustellen. Zudem bestimmt die Oberflächenenergie maßgeblich die Eigenschaften von Nanopartikeln, sodass ein Element mit einer geringen solchen energetisch bevorzugt die Oberfläche bildet.
Diese Arbeit zeigt auf, wie die sauerstoffbasierte Oxidation und die unterschiedlichen Oberflächenenergien der legierungsbildenden Elemente die Struktur, die Morphologie und die chemische Verteilung der Elemente innerhalb der Nanopartikel beeinflussen und so die Legierungsbildung einer hartmagnetischen Sm(Pr)Co-Phase steuern. Mithilfe von aberrationskorrigierter, hochauflösender Transmissionselektronenmikroskopie in Verbindung mit Elektronenenergieverlustspektroskopie werden Morphologie, Elementverteilung und Struktur von unterschiedlich hergestellten Sm(Pr)Co-Nanopartikeln untersucht und analysiert. Die auftretende Segregation der Seltenen Erden an die Oberfläche der Nanopartikel wird zum einen auf eine sauerstoffinduzierte, zum anderen auf eine intrinsische Segregation, also eine durch unterschiedliche Oberflächenenergien der legierungsbildenden Elementen hervorgerufene Segregation zurückgeführt. Anhand eines entwickelten geometrischen Modells wird zwischen den beiden Ursachen der Segregation unterschieden. Das Verständnis um die kausalen Zusammenhänge der Segregation lässt den Schritt zur Herstellung hartmagnetischer intermetallischer SmCo-basierter Nanopartikel zu. Hierzu werden speziell Nanopartikelagglomerate geformt und optisch in einem Lichtofen erhitzt, sodass die Primärpartikel in den Agglomeraten versintern und schließlich das resultierende sphärische Partikel kristallisiert. HRTEM-Aufnahmen und Elektronenbeugung bestätigen die erfolgreiche Herstellung von SmCo5- und Sm2Co17-basierten Nanopartikeln. Die Koerzitivfeldstärke dieser Partikelensembles beträgt 1,8T und einem Maximum in der Schaltfeldverteilung bei 3,6T. Die magnetischen Eigenschaften spiegeln die analysierten strukturellen, morphologischen und chemischen Eigenschaften der Nanopartikel wider.
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Conlon, Jay S. "Upgrading the Magneto-optical Kerr Effect Apparatus to Determine Polar Component of Magnetization in Py/SmCo/Si Thin Films." Thesis, California State University, Long Beach, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10786227.
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In this study, magneto-optical Kerr effect (MOKE) is measured on magnetic thin-film samples composed of permalloy (Py) and samarium-cobalt (SmCo) on a silicon substrate with 102 A of Py, but varying thicknesses of SmCo (344 to 1146 A ). This is done to see the effects of SmCo layer thickness on the magnetic switching of top Py layer. A new optical element, a photoelastic modulator (PEM), is introduced to the existing MOKE system and allows for the measurement of the Kerr ellipticity of the samples. Longitudinal and polar components of magnetization were analyzed from Kerr ellipticity hysteresis loop. It is shown that the coercivity values of the samples obtained from Kerr signal in this research stayed similar. However, the magnetic switching behavior shows a correlation to sample thickness. These results show that the magnetic switching behavior of the top Py layer is directly affected by varying SmCo layer thickness and this clearly shows up in Kerr rotation and Kerr ellipticity hysteresis loops.
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Walther, Arnaud. "Développement de couches magnétiques dures pour MEMS : application à un microswitch magnétique bistable." Phd thesis, Université Joseph Fourier (Grenoble), 2007. http://tel.archives-ouvertes.fr/tel-00348109.
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Le but de ce travail de thèse est de réaliser un microswitch magnétique bistable à base d'aimants permanents. De nouveaux designs de tels microswitch ont été dessinés afin d'obtenir à la fois des forces de contact plus élevés et des courants de commutation plus faibles que les systèmes semblables existants déjà. Des logiciels de simulations magnétiques ont été utilisés afin d'évaluer le comportement statique et dynamique de ces micro relais. Des couches épaisses (>1 µm) de matériaux magnétiques durs hautes performances (NdFeB, SmCo) ont été déposées par pulvérisation cathodique triode. Cette technique de pulvérisation permet d'avoir des vitesses de dépôt élevées sur de grandes surfaces. Les conditions de dépôt et de traitements thermiques de ces couches ont été étudiés afin d'obtenir de grandes coercivités, de grandes rémanences et des textures particulières. Enfin, des briques de base technologiques ont été développées afin d'intégrer ces films magnétiques dans un process de microtechnologie et de réaliser finalement de nouveaux microsystèmes magnétiques. Ce travail est inclus dans le projet ANR Nanomag2 dont le but final est de fabriquer des micro-relais RF pour des applications spatiales.
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Walther, Arnaud. "Développement de couches magnétiques dures pour MEMS : application à un microswitch magnétique bistable." Phd thesis, Grenoble 1, 2007. http://www.theses.fr/2007GRE10110.
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Le but de ce travail de thèse est de réaliser un microswitch magnétique bistable à base d'aimants permanents. De nouveaux designs de tels microswitch ont été dessinés afin d'obtenir à la fois des forces de contact plus élevés et des courants de commutation plus faibles que les systèmes semblables existants déjà. Des logiciels de simulations magnétiques ont été utilisés afin d'évaluer le comportement statique et dynamique de c~s micro relais. Des couches épaisses (> 1 /lm) de matériaux magnétiques durs hautes performances (NdFeB, SmCo) ont été déposées par pulvérisation cathodique triode. Cette technique de pulvérisation permet d'avoir des vitesses de dépôt élevées sur de grandes surfaces. Les conditions de dépôt et de traitements thermiques de ces couches ont été étudiés afin d'obtenir de grandes coercivités, de grandes rémanences et des textures particulières. Enfin, des briques de base technologiques ont été développées afin d'intégrer ces films magnétiques dans un process de microtechnologie et de réaliser fmalement de nouveaux microsystèmes magnétiques. Ce travail est inclus dans le projet ANR Nanomag2 dont le but final est de fabriquer des micro-relais RF pour des applications spatialesThe aim of this PhD thesis is to realize a bistable microswitch using integrated magnets. New designs of such microswitches have been drawn in order to obtain both higher contact forces and lower commutation currents compared to such existing systems. Magnetic simulation softwares have been used to assess static and dynamic behaviour of the micro-switches. Then thick films (> 1 /lm) of high performance hard magnetic materials (NdFeB, SmCo) have been deposited with triode sputtering, which enables high deposition rates on large areas. Conditions of sputtering and heat treatments were studied to get high coercivities, high remanences and special textures. Basic technological steps have been developed to integrate these magnetic films into a micro-technological process in order to finally realize new magnetic micro-systems. This work was part of the project Nanomag2 whose final goal is to fabricate a RF-microswitch for spatial applications
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Lam, Wing See. "THE ISOLATION AND CHARACTERIZATION OF ARABIDOPSIS AtSMC1 AND AtSMC3." Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1092170063.
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Laugsch, Magdalena, Jochen Seebach, Hans Schnittler, and Rolf Jessberger. "Imbalance of SMC1 and SMC3 Cohesins Causes Specific and Distinct Effects." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-127228.
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SMC1 and SMC3 form a high-affinity heterodimer, which provides an open backbone of the cohesin ring, to be closed by a kleisin protein. RNAi mediated knock-down of either one heterodimer partner, SMC1 or SMC3, is expected to cause very similar if not identical phenotypes. However, we observed highly distinct, protein-specific phenotypes. Upon knock-down of human SMC1, much of SMC3 remains stable, accumulates in the cytoplasm and does not associate with other cohesin proteins. Most of the excess nuclear SMC3 is highly mobile and not or only weakly chromosome-associated. In contrast, human SMC3 knock-down rendered SMC1 instable without cytoplasmic accumulation. As observed by differential protein extraction and in FRAP experiments the remaining SMC1 or SMC3 proteins in the respective SMC1 or SMC3 knock-down experiments constituted a cohesin pool, which is associated with chromatin with highest affinity, likely the least expendable. Expression of bovine EGFP-SMC1 or mouse EGFP-SMC3 in human cells under conditions of human SMC1 or SMC3 knock-down rescued the respective phenotypes, but in untreated cells over-expressed exogenous SMC proteins mis-localized. Paucity of either one of the SMC proteins causes RAD21 degradation. These results argue for great caution in interpreting SMC1 and SMC3 RNAi or over-expression experiments. Under challenged conditions these two proteins unexpectedly behave differently, which may have biological consequences for regulation of cohesin-associated functions and for human cohesin pathologies.
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Laugsch, Magdalena, Jochen Seebach, Hans Schnittler, and Rolf Jessberger. "Imbalance of SMC1 and SMC3 Cohesins Causes Specific and Distinct Effects." Public Library of Science, 2013. https://tud.qucosa.de/id/qucosa%3A27288.
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SMC1 and SMC3 form a high-affinity heterodimer, which provides an open backbone of the cohesin ring, to be closed by a kleisin protein. RNAi mediated knock-down of either one heterodimer partner, SMC1 or SMC3, is expected to cause very similar if not identical phenotypes. However, we observed highly distinct, protein-specific phenotypes. Upon knock-down of human SMC1, much of SMC3 remains stable, accumulates in the cytoplasm and does not associate with other cohesin proteins. Most of the excess nuclear SMC3 is highly mobile and not or only weakly chromosome-associated. In contrast, human SMC3 knock-down rendered SMC1 instable without cytoplasmic accumulation. As observed by differential protein extraction and in FRAP experiments the remaining SMC1 or SMC3 proteins in the respective SMC1 or SMC3 knock-down experiments constituted a cohesin pool, which is associated with chromatin with highest affinity, likely the least expendable. Expression of bovine EGFP-SMC1 or mouse EGFP-SMC3 in human cells under conditions of human SMC1 or SMC3 knock-down rescued the respective phenotypes, but in untreated cells over-expressed exogenous SMC proteins mis-localized. Paucity of either one of the SMC proteins causes RAD21 degradation. These results argue for great caution in interpreting SMC1 and SMC3 RNAi or over-expression experiments. Under challenged conditions these two proteins unexpectedly behave differently, which may have biological consequences for regulation of cohesin-associated functions and for human cohesin pathologies.
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Ullal, Pranav. "Functional study of the Smc5/Smc6 complex through analysis of novel interactors." Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511891.
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Tingström, Victor. "Sequential parameter and state learning in continuous time stochastic volatility models using the SMC² algorithm." Thesis, KTH, Matematisk statistik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-177104.
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In this Master’s thesis, joint sequential inference of both parameters and states of stochastic volatility models is carried out using the SMC2 algorithm found in SMC2: an efficient algorithm for sequential analysis of state-space models, Nicolas Chopin, Pierre E. Jacob, Omiros Papaspiliopoulos. The models under study are the continuous time s.v. models (i) Heston, (ii) Bates, and (iii) SVCJ, where inference is based on options prices. It is found that the SMC2 performs well for the simpler models (i) and (ii), wheras filtering in (iii) performs worse. Furthermore, it is found that the FFT option price evaluation is the most computationally demanding step, and it is suggested to explore other avenues of computation, such as GPGPU-based computing.I denna Masteruppsats estimeras sekventiellt parametrar och tillstånd i stokastiska volatilitetsmodeller nyttjandes SMC2 -algoritmen som återfinns i [1]. Modellerna som studeras är de kontinuerliga s.v.-modellerna (i) Heston, (ii) Bates och (iii) SVCJ, där inferens baseras på optionspriser. Vi finner att SMC2 presterar bra resultat för de enklare modellerna (i) och (ii) emedan filtrering för (iii) presterar sämre. Vi finner ytterligare att det beräkningsmässigt tyngsta steget är optionsprissättning nyttjandes FFT, därför föreslås det att undersöka andra beräkningssätt, såsom GPGPU-beräkning
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James, Rosalina Dee. "Cohesin proteins SMC1 and SMC3 : roles in aneuploidy and in meiotic chromosome dynamics /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/6333.
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Schmidt, Frank [Verfasser], Ludwig [Akademischer Betreuer] Schultz, Ludwig [Gutachter] Schultz, and Oliver [Gutachter] Gutfleisch. "Die Bedeutung der Segregations- und Oxidationsneigung Seltener Erden für die Einstellung hartmagnetischer intermetallischer Phasen in SmCo-basierten Nanopartikeln / Frank Schmidt ; Gutachter: Ludwig Schultz, Oliver Gutfleisch ; Betreuer: Ludwig Schultz." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://d-nb.info/1156851467/34.
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Schmidt, Frank [Verfasser], Ludwig [Akademischer Betreuer] Schultz, Ludwig Gutachter] Schultz, and Oliver [Gutachter] [Gutfleisch. "Die Bedeutung der Segregations- und Oxidationsneigung Seltener Erden für die Einstellung hartmagnetischer intermetallischer Phasen in SmCo-basierten Nanopartikeln / Frank Schmidt ; Gutachter: Ludwig Schultz, Oliver Gutfleisch ; Betreuer: Ludwig Schultz." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-234251.
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Schmidt, Frank [Verfasser], Ludwig Akademischer Betreuer] Schultz, Ludwig [Gutachter] Schultz, and Oliver [Gutachter] [Gutfleisch. "Die Bedeutung der Segregations- und Oxidationsneigung Seltener Erden für die Einstellung hartmagnetischer intermetallischer Phasen in SmCo-basierten Nanopartikeln / Frank Schmidt ; Gutachter: Ludwig Schultz, Oliver Gutfleisch ; Betreuer: Ludwig Schultz." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://d-nb.info/1156851467/34.
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Esteras, Bejar Miguel. "Development of methods for the study of the role of the Smc5-Smc6 complex in DNA stability." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/11072.
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The Structural Maintenance of Chromosomes (SMC) proteins play a number of crucial roles in the metabolism of chromosomes. The Smc5-Smc6 complex is the least well understood of the complexes formed by SMC proteins. Hitherto, the Smc5-Smc6 complex has been linked to protein post-translational modification by sumoylation and restart of collapsed replication forks by homologous recombination between sister chromatids (SCR). However, a detailed characterization of the roles of the Smc5-Smc6 complex is missing. The objective of this study is to characterize the function of the Smc5-Smc6 complex in DNA repair by SCR, and to identify sumoylation substrates of MMS21, a E3-sumoligase subunit of the Smc5-Smc6 complex. Recent studies suggest that DNA single-strand nicks are transformed to doublestrand breaks in a replication-dependent manner, and this triggers SCR. I developed an assay for the activation of SCR based on the expression of a site-specific nickase. Unfortunately, a stable site-specific nick was observed in only 30% of the population. This percentage was insufficient for the study of the molecular role of the Smc5-Smc6 complex during SCR. However, this assay could be used to confirm and further characterize the activation of SCR upon replication-induced DNA damage. To study the role of sumoylation within the Smc5-Smc6 activity, I have developed a proteome-wide approach for the in vivo identification of sumoylation-sites by mass spectrometry. This technique can be used for the identification of MMS21 substrates and for the mapping of their sumo-acceptor lysines. The mapping of sumo-acceptor sites allows the generation of sumo-specific mutant proteins that can be used to study the function of sumoylation. More than 360 sumo-acceptor lysines, belonging to 245 different proteins, were identified. In vivo sumoylation at these lysines was verified by MS-independent methods. In addition, I developed a SILAC-based mass spectrometry assay for the quantitative study of site-specific sumoylation.
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Kurfűrst, Jiří. "Optimalizace stroje s permanentními magnety na rotoru pomocí umělé inteligence." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-233585.
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The dissertation thesis deal with the design and the optimization of the permanent magnet synchronous machine (SMPM) based on the artificial intelligence. The main target is to apply potential optimization methods on the design procedure of the machine and evaluate the effectiveness of optimization and the optimization usefulness. In general, the optimization of the material properties (NdFeB or SmCo), the efficiency maximization with given nominal input parameters, the cogging torque elimination are proposed. Moreover, the magnet shape optimization, shape of the air gap and the shape of slots were also performed. The well known Genetic algorithm and Self-Organizing migrating algorithm produced in Czech were presented and applied on the particular optimization issues. The basic principles (iterations) and definitions (penalty function and cost function) of proposed algorithms are demonstrated on the examples. The results of the vibration generator optimization (VG) with given power 7mW (0.1g acceleration) and the results of the SMPM 1,1kW (6 krpm) optimization are practically evaluated in the collaboration with industry. Proposed methods are useful for the optimization of PM machines and they are further theoretically applied on the low speed machine (10 krpm) optimization and high speed machine (120 krpm) optimization.
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Wendhausen, Paulo Antonio Pereira. "Tecnologia de produção de imãs SmCo5." reponame:Repositório Institucional da UFSC, 1990. https://repositorio.ufsc.br/xmlui/handle/123456789/157650.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro TecnologicoMade available in DSpace on 2016-01-08T16:49:33Z (GMT). No. of bitstreams: 1 79101.pdf: 5471139 bytes, checksum: 99a9fdf6bb704c8cde1ada908776f365 (MD5) Previous issue date: 1990
Estudou-se o processo de obtenção de ímãs de SmCo5. O processo como um todo compreendeu as seguintes etapas: 1) produção da liga base de SmCo5 por processo de redução-difusão (R-D); 2) moagem da liga base; 3) ajuste da composição através da adição de uma liga de Sm2Co7 (obtida por fusão); 4) compactação do pó sob campo magnético; 5) sinterização e tratamento térmico dos ímãs. Os ímãs foram caracterizados através de análise química, microestrutural e de propriedades magnéticas. A composição química foi avaliada em termos de samário, cobalto, cálcio, e oxigênio, utilizando-se espectroscopia de energia dispersiva, fluorescência de raio-x e redução carbotérmica. Para análise microestrutural utilizaram-se técnicas de microscopia ótica e eletrônica (MEV) e as propriedades magnéticas, como a remanência e a coercitividade, foram avaliadas em magnetômetro de amostra vibrante. Empregando-se condições de tempo e temperatura de 4 horas e 1150oC e excesso de cálcio de 40% foi possível obter altos rendimentos combinados com um grau de desintegralibilidade satisfatório da liga. A liga base, com a composição química e composição de fases desejadas, foi obtida empregando-se um excesso da Sm2Co3 de 15%. A obtenção de uma microestrutura adequada à obtenção de boas propriedades magnéticas foi possível sinterizando-se ligas com teores de samário metálico em torno de 35% a 1100oC durante 1 hora.
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Salazar, Betancourt Luis Fernando. "Modélisation de la compression de SMCs haute-performance." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM079.
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Ce travail porte sur la simulation numérique et la modélisation du comportement thermo-mécanique des matériaux composites renforcés par des fibres. Spécifiquement les matériaux SMC (Sheet Moulding Compound) sont utilisés dans le processus de moulage par compression pour construire des pièces automobiles de haute performance. Ce travail est divisé en quatre chapitres, décrivant tout d’abord un modèle thermo-mécanique entièrement couplé pour les matériaux SMC standards et innovants à haute concentration en fibres (> 25% en volume). Le SMC est traité comme un mélange incompressible de fibre et de résine complété éventuellement par une phase de porosité compressible. Son anisotropie est modélisée au moyen de tenseurs structurels. La cinétique de réaction et de consolidation de la pièce est également modélisée et étudiée. Les données expérimentales mécaniques et thermiques enregistrées sur des échantillons de matériaux SMC sont comparées au modèle et à la solution numérique fournie par ce travail. D’un point de vue numérique, nous utilisons la méthode des domaines immergées o`u chaque phase est distinguée par une fonction distance signée. Nous décrivons le procédé de moulage par compression en proposant une résolution compressible anisotrope unifiée capable de décrire la transition compressible / incompressible du matériau SMC sous déformation. Cela permet de décrire la réponse mécanique du SMC et de prédire localement la consolidation (durcissement) de la pièce le long du cycle thermiqueThis work deals with the numerical simulation and modeling of thermomechanical analysis of fiber reinforcedcomposites materials. Specifically for SMC (Sheet Molding Compound) materials that are used in compression molding processes to build automotive high performance parts. The work is divided into fourchapters, firstly describing a fully coupled thermo-mechanical model for standard SMC materials and for innovative SMC with high fiber concentration (> 25% in volume). The SMC is treated as an incompressible mixtureof fibers and paste complemented by a compressible porosity phase. Its anisotropy is modeled by means of structural tensors. Kinetic of reaction and consolidation of the part is also modeled and studied. Mechanicaland thermal experimental data recorded on samples of SMC materials are compared to the model and numerical solution provided in this work. A numerical framework, we use the immersed boundary method and the level set method. We describe the compression molding process by proposing an unified anisotropic compressible resolution able to describe the transition between compressible/ incompressible of SMC materials under deformation. We are able to describe the mechanical response of the SMC and to predict locally the consolidation (curing) of thepart throughout the thermal cycle
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Menolfi, D. "ESSENTIAL POSTREPLICATIVE FUNCTIONS OF THE SMC5/6 COMPLEX." Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/264411.
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The structural maintenance of chromosomes (SMC) complex Smc5/6 is based on a heterodimer of two SMC subunits, Smc5 and Smc6, and six non-Smc element subunits, Nse1-6, all of which are essential for cell viability in most organisms. Smc5/6 safeguards genome integrity via different mechanisms, including stabilization of stalled replication forks, resolution of recombination intermediates, and maintenance of nucleolar integrity. However, the essential functions of Smc5/6 remain elusive. The aim of the present work was to understand when in the cell cycle the crucial functions of Smc5/6 are manifested and to identify them. Through the use of cell cycle regulated alleles, which enabled the restriction of various Smc5/6 subunits expression to either S or G2/M phases of the cell cycle, we uncovered that the essential roles are executed postreplicatively in G2/M. By further genetic screens, molecular approaches and genome-wide studies, we identified three chromosome topology and recombination-related processes that are crucially sensitive to low amounts of Smc5/6 specifically in G2/M. First, Smc5/6 plays a topological role affecting the formation and/or the resolution of Rad5-Mms2-Ubc13 chromatin structures that are later engaged by Sgs1-Top3-Rmi1. Second, Smc5/6 facilitates an epigenetic pathway that ensures silencing of specific loci, such as repetitive DNA regions, thereby preventing unrestrained recombination. Third, Smc5/6 has an anti-fragility function, facilitating replication through natural pausing elements and site-specific replication fork barriers and preventing their breakage in mitosis during chromosome segregation.
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Buermann, Frank. "Architecture of SMC-kleisin complexes." Diss., Ludwig-Maximilians-Universität München, 2015. http://nbn-resolving.de/urn:nbn:de:bvb:19-183573.
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In all cellular systems, the transmission of bulk genetic information during proliferation occurs in the form of chromosomes. The segregation of these entities upon cell division is of pivotal importance for all forms of life. Structural maintenance of chromosomes (SMC)-kleisin complexes are ubiquitous and essential factors that ensure proper organisation and segregation of the genetic material. Aim of this work was to elucidate evolutionary conserved features in the architecture of SMC-kleisin complexes, and to probe these features for functional relevance. We find that two major architectural themes have been constrained by evolution: (I) SMC-kleisin complexes form asymmetric assemblies with a ring-like topology, whereby a kleisin monomer bridges two different binding sites on a SMC dimer, (II) SMC-kleisin complexes form rod-like structures, whereby the SMC proteins of a given dimer are closely juxtaposed in a well-defined manner. Based on these findings, we propose that SMC-kleisin complexes from all domains of life act by a unifying mechanism.Die universellen Träger genetischer Information bei der Vermehrung zellulären Lebens sind die Chromosomen. Die Segregation dieser Einheiten während der Zellteilung ist für alle Organismen unabdingbar. Structural Maintenance of Chromosomes (SMC)-Kleisin-Komplexe sind universelle und essentielle Faktoren, welche die korrekte Organisation und Segregation des Erbmaterials sicherstellen. Ziel dieser Arbeit war es, evolutionär konservierte Erscheinungsmerkmale von SMC-Kleisin-Komplexen aufzudecken, und diese Merkmale auf funktionelle Relevanz zu testen. Wir haben zwei evolutionär invariante Leitmotive der Architektur von SMC-Kleisin-Komplexen identifiziert: (I) SMC-Kleisin-Komplexe haben eine asymmetrische Konfiguration, in der ein Kleisin-Monomer zwei unterschiedliche Bindungsstellen eines SMC-Dimers miteinander verbindet, (II) SMC-Kleisin-Komplexe bilden stäbchenförmige Strukturen, in denen die SMC-Proteine eines Dimers in einer wohl definierten Art eng aneinander liegen. Basierend auf diesen Resultaten schlagen wir vor, dass sämtliche SMC-Kleisin-Komplexe aus allen phylogenetischen Domänen einen gemeinsamen Funktionsmechanismus haben.
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Knust, Tobias [Verfasser], and Peter [Akademischer Betreuer] Graumann. "Regulation of SMC by associate proteins and ATP = Regulation von SMC durch assoziierte Proteine und ATP." Freiburg : Universität, 2011. http://d-nb.info/112345888X/34.
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Ibars, Esteve Eva Irene. "Molecular analysis of Smc5/6-dependent sumoylation and ubiquitination." Doctoral thesis, Universitat de Lleida, 2021. http://hdl.handle.net/10803/671461.
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Les cèl·lules eucariotes dediquen grans esforços per mantenir la integritat del seu genoma. Els complexos SMC (Structural Maintenance of Chromosomes), que inclouen la cohesina, la condensina i el complex Smc5/6, coordinen múltiples activitats cromosòmiques que protegeixen el nostre genoma. Particularment, el complex Smc5/6 té un paper clau en la reparació de l’ADN per recombinació homòloga, l’estabilització de les forquilles de replicació i la resolució de les cromàtides germanes, i és el membre més desconegut de la família SMC. A diferència de la cohesina i la condensina, conté dos dominis de tipus RING: un en la subunitat Nse1, amb potencial activitat ubiqüitina lligasa, i l’altre en la subunitat Nse2, que regula la transferència de SUMO a les proteïnes substrat.
Nse2 s’uneix al coiled-coil de Smc5 a través del seu domini essencial N-terminal, mentre que la seva meitat C-terminal, que codifica per el domini SUMO lligasa, és prescindible per a la supervivència cel·lular. Malgrat això, la sumoilació de diferents subunitats dels SMC i d’altres dianes cromosòmiques depenent de Nse2 controla diverses vies biològiques directament implicades en el manteniment de la integritat genòmica. Tot i això, els processos que regulen la seva activitat SUMO E3 lligasa segueixen sent poc coneguts. En aquest estudi, es descriu un nou mecanisme mitjançant el qual la interacció entre un sensor carregat positivament en el braç de Smc5 i l’ADN estimula l’activitat SUMO E3 lligasa de Nse2. A més a més, hem realitzat un detallat anàlisi funcional de les diferents característiques estructurals presents al domini C-terminal de Nse2 en llevat. Aquesta caracterització revela que l’hèlix alfa C-terminal, que s’ha associat amb un desordre genètic rar, té una funció estructural important i afecta directament a l’estabilitat de Nse2. D’altra banda, hem identificat dues regions que incrementen la sumoilació in vitro. Sorprenentment, els nostres resultats també mostren que mutacions puntuals en residus conservats que coordinen l’àtom de zinc no afecten a la sumoilació in vivo de Smc5.
L’altra subunitat del complex Smc5/6 amb un domini RING, Nse1, s’ha descrit que promou funcions de reparació de l’ADN i que manté l’estabilitat del genoma. Tot i això, fins al moment, no s’han descrit dianes per la seva activitat E3 lligasa. Aquí, fem servir proteòmica quantitativa sense marcatge per tal de comparar l’ubiquitinoma de cèl·lules wild type o mutants en el RING de Nse1. Particularment, la subunitat més gran de l’ARN POL I, Rpa190, està menys ubiquitinada en les cèl·lules nse1 mutants. Rpa190 es modifica durant la transcripció activa, i els mutants no-ubiquitinables rpa190-KR són sensibles a inhibidors de l’elongació transcripcional i són resistents a la degradació proteasomal regulada per BMH-21.
En conjunt, aquests resultats proporcionen noves dades sobre la regulació i les dianes de les activitats SUMO i ubiquitina lligasa dependents de Smc5/6, que són una part crucial dels mecanismes usats pel complex Smc5/6 per tal de preservar la integritat del genoma.Las células eucariotas dedican grades esfuerzos para mantener la integridad de su genoma. Los complejos SMC (Structural Maintenance of Chromosomes) que incluyen la cohesina, la condensina y el complejo Smc5/6, coordinan múltiples actividades cromosómicas que protegen nuestro genoma. Particularmente, el complejo Smc5/6 tiene un papel crucial en la reparación del ADN por recombinación homóloga, la estabilización de las horquillas de replicación y la resolución de cromátidas hermanas, y es el miembro más desconocido de la familia SMC. A diferencia de la cohesina o la condensina, tiene dos dominios de tipo RING: uno en la subunidad Nse1, con potencial actividad ubiquitina ligasa, y el otro en la subunidad Nse2, del que se ha descrito que regula la transferencia de SUMO a las proteínas sustrato. Nse2 se une al coiled-coil de Smc5 a través de su dominio esencial N-terminal, mientras que su mitad C-terminal, que codifica por el dominio SUMO ligasa, es prescindible para la supervivencia celular. Aun así, la sumoilación de diferentes subunidades SMC y otras dianas cromosómicas dependiente de Nse2 controla varias vías biológicas directamente implicadas en el mantenimiento de la integridad genómica. Sin embargo, los procesos que regulan su actividad E3 ligasa siguen siendo poco conocidos. En este estudio, describimos un nuevo mecanismo mediante el cual la interacción entre un sensor cargado positivamente en el brazo de Smc5 y el ADN estimula la actividad SUMO E3 ligasa de Nse2. Además, hemos realizado un detallado análisis funcional de las diferentes características estructurales presentes en el dominio C-terminal de Nse2 en levadura. Esta caracterización revela que la hélice alfa C-terminal, que se ha asociado con un desorden genético raro, tiene una importante función estructural y afecta directamente la estabilidad de Nse2. Además, hemos identificado dos regiones que incrementan la sumoilación in vitro. Sorprendentemente, nuestros resultados también muestran que las mutaciones puntuales en residuos conservados que coordinan el átomo de zinc no afectan a la sumoilación in vivo de Smc5. La otra subunidad del complejo Smc5/6 con un dominio RING, Nse1, se ha descrito que promueve funciones de reparación del ADN y que mantiene la estabilidad del genoma. Sin embargo, hasta la fecha, no se han descrito dianas para su actividad ubiquitina-E3 ligasa. Aquí, usamos proteómica cuantitativa sin marcaje para comparar el ubiquitinoma de células wild type y mutantes en el RING de Nse1. Particularmente, la subunidad mayor de la ARN POL I, Rpa190, está menos ubiquitinada en el células nse1 mutantes. Rpa190 se modifica durante la transcripción activa, y los mutantes no-ubiquitinables rpa190-KR son sensibles a inhibidores de elongación transcripcional y son resistentes a la degradación proteasomal mediada por BMH-21. En conjunto, estos resultados proporcionan nuevos datos en la regulación y las dianas de las actividades SUMO y ubiquitina ligasa dependientes de Smc5/6, que son una parte crucial de los mecanismos usados por el complejo Smc5/6 para preservar la integridad del genoma.
Eukaryotic cells devote large efforts to maintain the integrity of their genome. The Structural Maintenance of Chromosomes (SMC) complexes, which include cohesin, condensin and Smc5/6, coordinate multiple chromosomal activities that safeguard our genome. Particularly, the Smc5/6 complex plays crucial roles in DNA repair by homologous recombination, replication fork stability and sister chromatid resolution, and it is the most unknown member of the SMC family. Unlike cohesin and condensin, it contains two RING-type domains: one in the Nse1 subunit, with potential ubiquitin ligase activity, and the other in the Nse2 subunit, which has been shown to mediate the transfer of SUMO to substrate proteins. Nse2 binds to the Smc5 coiled-coil through its essential N-terminal domain, whereas its C-terminal half, coding for the SUMO ligase domain, is dispensable for cell survival. Despite this, Nse2-dependent sumoylation of SMC complexes and other chromosomal targets has been reported to control several biological pathways directly involved in genome integrity. However, the processes that regulate its E3 ligase activity remain poorly understood. In this study, we describe a novel mechanism by which the interaction between a positively-charged patch in the coiled-coil of Smc5 and DNA stimulates the Nse2 SUMO E3 ligase activity. In addition, we have performed a detailed functional analysis of the different structural features present in the C-terminal domain of Nse2 in yeast. This characterization reveals that the last C-terminal alpha-helix, which has been related to a rare genetic disorder, has an important structural function and directly affects Nse2 stability. In addition, we have identified two regions that enhance sumoylation in vitro. To our surprise, our results also show that mutations in conserved residues coordinating the zinc ion do not impair Smc5-sumoylation in vivo. The other RING-type subunit of the Smc5/6 complex, Nse1, has also been described to promote DNA repair functions and to maintain genome stability. However, no targets for its ubiquitin-E3 ligase activity have been identified until now. Here, we use label-free quantitative proteomics to compare the ubiquitinome of wild type and nse1 RING mutant cells. Particularly, the largest subunit of the RNA POL I, Rpa190, is less ubiquitinated in nse1 mutant cells. Rpa190 is modified during active transcription, and non-ubiquitinable rpa190-KR cells are sensitive to transcriptional elongation inhibitors and are resistant to BMH-21-mediated proteasomal degradation. Overall, these results provide novel information on the regulation and targets of the Smc5/6-dependent SUMO and ubiquitin ligase activities, which are a critical part of the mechanisms used by the Smc5/6 complex to preserve the integrity of the genome.
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Newcombe, Sonya. "The role of the Smc5/6 complex in meiosis." Thesis, University of Sussex, 2017. http://sro.sussex.ac.uk/id/eprint/69253/.
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Cobbe, Neville Richard. "Phylogenetic and functional analysis of SMC4 in Drosophila melanogaster." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/11994.
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Sexton, David James. "Investigating the functional role of SMOC-1 in zebrafish." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/22907.
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True anophthalmia is the most severe congenital eye malformation. With absence of the eye, optic nerve, chiasm and optic tracts. Identifying the genes that cause genetic true anophthalmia should improve our understanding of the critical processes required for development of the eye. Recessive loss-of-function mutations in SMOC1 have been identified as the cause of Ophthalmo-acromelic syndrome (OAS), a multisystem disorder which has true anophthalmia as a prominent feature with characteristic limb and facial malformations. In order to establish the function of SMOC1 in development I used the zebrafish as a model organism to support a link between SMOC-1 and BMP signalling. As a first step I characterised the genomic structure of zebrafish smoc1 gene. I was able to correct an error in the zebrafish genome (Zv8) that annotated zsmoc1 as two fragmented and rearranged orthologous loci. However, using RTPCR I could show that there is in fact a single intact zsmoc1 transcript. In addition, I was able to identify an un-annotated 5’ coding exon using 5' RACE which showed that the full open reading frame includes a signalling peptide. RT-PCR was also used to identify several novel zsmoc1 splice isoforms. To explore the link between zsmoc1 and bmp signalling I used injection of antisense morpholino oligonucleotide and capped mRNA to examine the effects of loss-of-function and overexpression respectively of smoc1 and genes functioning in the bmp signalling pathway. The resulting embryos were analysed using morphometric analysis (Kishimoto scale), a quantitative assay of dorsalisation/ventralisation and live imaging of reporter transgenic fish. I developed a quantitative RT-PCR assay for expression of dorsal (otx2 and runx3) and ventral (eve1 and gata2) marker genes. I established a reliable system for live imaging of zebrafish development between 8 hpf and 24 hpf. By combining this system with fluorescent transgenic reporters marking the eye field (rx3:gfp reporter) and BMP-signaling (BRE:gfp reporter) I was able to accurately quantitate the effect of smoc1 depletion on eye size and SMAD1/5/8 signalling in the eye. These results support the predictions from the Drosophila homologue Pent that zsmoc1 functions as an antagonist of bmp signalling. Finally, I describe my attempt to produce a zebrafish model for OAS using genome editing technology. I designed, produced and validated transcription activator like effectors nucleases (TALENs) targeted to the zsmoc1 open reading frame using the Voytas Goldengate method. I designed and optimised a novel strategy to demonstrate targeted cutting activity for in vitro validation. Following injections of the in vitro validated TALEN into zebrafish embryos I used Ion Torrent sequencing to assess the in vivo activity of the engineered TALEN pairs. Unfortunately these TALENs were not able to cut the targeted locus in vivo.
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Ďuriš, Martin. "Řízení modelu linky SMC MAP 205." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232001.
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The thesis deal with a model of electronically controlled assembly minicell MAP-205 based on pneumatic drives and its debugging. Assembly minicell simulates assembling and disassembling of simple four item assembly. Minicell is controlled by Phoenix Contact ILC 150ETH programmable logic controller. The minicell control program is composed of several subroutines/subprograms providing various functionalities to assembly minicell. There is integrated HMI created in Control Web application too. It allows to display actual status of each component and to control each drive in manual mode. Communication between HMI based on PC and PLC controller is supported by Bluetooth module and OPC server.
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O'Donohue, Daniel J. "First-term retention of enlisted Selected Marine Corps (SMCR) Reservists." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23233.
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This thesis examines factors that influence a male, first-term enlisted reservist's decision to remain in the Selected Marine Corps Reserve (SMCR). Specifically, the logistic regression model was used to determine the relative impact of bio-demographic and both pecuniary and nonpecuniary job factors on retention. Models were developed for both nonprior (NPS) and prior active service (PS) reservists. The database was a combination of the responses of participants in the 1986 Reserve Components Surveys and their personnel records from the Reserve Components Common Personnel Data System. The thesis concludes with reserve policy implications and recommendations for further research. Important findings of this thesis were: Reserve income has a statistically significant and positive impact on SMCR retention. Civilian income was not found to be a factor. Educational benefits, civilian job-related training, and retirement benefits were found to be significant factors in retaining prior service reservists. Keywords: Marine corps personnel, Job training, Personnel retention, Theses
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Fran?a, George Sand Le?o Ara?jo de. "Estudo s?smico no a?ude Tucunduba, Senador S?, CE." Universidade Federal do Rio Grande do Norte, 1999. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18772.
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Previous issue date: 1999-07-12Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The Tucunduba Dam, is west of Fortaleza, Cear? State. The seismic monitoring of the area, with an analogical station and seven digital stations, had beginning on June 11, 1997. The digital stations, operated from June to November 1997. The data collected in the period of digital monitoring was analyzed for determination of hypocenters, focal mechanisms, and shear-wave anisotropy analysis. For determination of hypocenters, it was possible to find an active zone of nearly 1 km in length, with depth between 4.5 and 5.2 km. A 60AZ/88SE fault plane was determined using the least-squares method and hypocenters of a selected set of 16 earthquakes recorded. Focal mechanisms were determined, in the composite fault plane solution, a strike-slip fault, trending nearly E-W, was found. Single fault plane solutions were obteined to some earthquakes presented mean values of 65 (azimuth), and 80 (dip). Shear-wave anisotropy was found in the data. Polarization directions and travel time delays, between S spliting waves, were determined. It was not possible to obtain any conclusion on the cause of the observed anisotropy. It is not clear if there is correlation between seismicity and mapped faults in the area, although the directions obtained starting from the hipocentros and focal mechanism are they are consistent with directions, observed in the area, photo, topographic and fractures directions observed in the area
o A?ude Tucunduba est? localizado no munic?pio de Senador S?, a aproximadamente 290 km a oeste de Fortaleza - CE. O monitorarnento s?smico da regi?o, por meio de urna rede sismogr?fica local, teve in?cio em 11 de junho de 1997, logo ap?s a ocorr?ncia de um evento com magnitude 3,2 mb, no dia 09 de junho de 1997. O monitorarnento foi realizado com uma esta??o anal?gica (utilizada na determina??o da magnitude com a dura??o e na contagem do n?mero de eventos por dia), e sete esta??es digitais. As esta??es digitais, com tr?s componentes cada, operaram no per?odo de junho a novembro de 1997. Neste trabalho foram analisados os dados coletados pelas esta??es digitais objetivando a determina??o de hipocentros, mecanismos focais e an?lise de anisotropia s?smica. Na determina??o hipocentral utilizou-se o programa HYPO71, com o modelo de semiespa?o, de par?metros iguais a 5,95, para a velocidade da onda P, e 1,69, para a raz?o Entre as velocidades das ondas P e S. Dessa forma, foi poss?vel detectar urna zona ativa, de aproximadamente 1 km de extens?o e profundidade variando de 4,5 a 5,2 km. Com um conjunto de 16 sismos, registrados na mesmas seis esta??es, foi determinado um plano de falha a partir dos hipocentros, pelo m?todo dos m?nimos quadrados, obtendo-se os valores de 60? para o azimute e 88? para o mergulho. A determina??o de mecanismos focais foi feita de duas formas distintas, utilizando-se os programas FPFIT e FOCMEC. Na solu??o do mecanismo composto (FPFIT), encontrou-se uma falha de dire??o aproximadamente E-W (265? para o azimute, 88? para o mergulho), transcorrente, sinistral, com componente normal.Foram determinados v?rios mecanismos individuais (FOCMEC), tendo-se obtido um valor m?dio de 65? para o azimute e 80? para o mergulho. Estimativas preliminares do esfor?o horizontal m?ximo, a partir da dire??o do eixo P, n?o s?o concordantes com valores anteriormente obtidos para sismos ao sul do A?ude Tucunduba. Na regi?o tamb?m foi feito um estudo de anisotropia, onde se verificou a presen?a de anisotropia na propaga??o da onda S, possibilitando a obten??o das dire??es de polariza??es e dos tempos de atraso entre as ondas S divididas, para duas esta??es. A dificuldade de se ter uma boa estimativa para o esfor?o horizontal m?ximo, na regi?o, impossibilitou qualquer conclus?o sobre a causa da anisotropia observada. N?o se pode concluir, de forma clara, que a atividade s?smica possa estar associada diretamente a falhas mapeadas na regi?o. As dire??es do plano de falha pelo ajuste por m?nimos quadrados, FPFIT e FOCMEC (valor m?dio) est?o no intervalo de NE e EW. Estes valores s?o consistentes com as dire??es de fotolineamentos, lineamentos topogr?ficos, positivos e negativos, e de fraturas secas, observadas na regi?o.
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Oldenbo, Magnus. "Mechanical behaviour of SMC composites and structures /." Luleå, 2002. http://epubl.luth.se/1402-1757/2002/06/index.html.
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Hartmann, Paulo Airton. "Feuerbach e o ate?smo antropol?gico." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2012. http://tede2.pucrs.br/tede2/handle/tede/2904.
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Previous issue date: 2012-08-29Feuerbach answer the question: Where and how the religion arises? The man, endowed of intelligence and consciousness, is able to think as individuals and as species. As an individual perceives limited. As a species finds its essence. His essence and all its potentials and wishes, he projects this to out of himself and call this of God. Feuerbach, with his atheism, wants repay to man the dignity lost and shows that theology is, on reality, an anthropology. Finally is made the critique of Feuerbach s critique
Feuerbach responde ? pergunta: de onde e como surge a religi?o? O homem, dotado de intelig?ncia e consci?ncia, ? capaz de pensar-se como indiv?duo e como esp?cie. Como indiv?duo percebe-se limitado. Como esp?cie descobre a sua ess?ncia. Sua ess?ncia e todas as suas potencialidades e desejos ele as projeta para fora de si e as chama Deus. Feuerbach, com seu ate?smo, quer restituir ao homem a dignidade perdida e demonstrar que a teologia ?, na verdade, uma antropologia. Por fim faz-se a cr?tica da cr?tica de Feuerbach
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Cabrera, Carlos Andres Cuenca. "Ductile failure prediction using phenomenological fracture model for steels: calibration, validation and application." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3135/tde-27082018-075853/.
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The present thesis shows the analysis, calibration, and application of the stress modified criticai strain criterion to predict ductile failure for an A285 steel. To obtain the mechanical behavior of the material, experimental tests were carried out by implementation of 5 different types of geometries: smooth round bar, notched round bar (R=1 , 2, 3 mm), and, deep and shallow cracked SE(B) specimens. Then, for the calibration process of the mechanical properties finite element models were generated, using 30 solid elements with 8 nodes (C308), matching the geometry and the properties of the tested specimens. To calibrate the elastoplastic behavior was used the experimental and numerical response obtained from the smooth and notched round bar specimens; and, for the damage calibration was used the responses obtained from both deep and shallow crack SE(B) specimens. Once the mechanical properties were calibrated, then there were obtained the SMSC criterion factors represented by the equation ..... and, the damage condition which is represented by the displacement at failure (.......) and exponential factor (....). This calibrated model was able to recover the SE(B) experimental responses that validate the use of the characterized material in a complex structure. Then, the fully characterized material was applied in two pipelines which have externai initial circumferential elliptical crack; being the first one pipe with shallow crack and the second one with deep crack. Finally, both pipes were submitted to tension loads to predict the ductile damage behavior, obtaining the necessary load to the crack start growing, and the evolution of the failure.A presente dissertação apresenta o processo de análise, calibração e aplicação das propriedades mecânicas, incluindo o comportamento elastoplástico e de dano, para o aço A285, utilizando o critério \"Stress modified criticai strain\" (SMCS). Para obter o comportamento mecânico do material, testes experimentais foram realizados com a implementação de 5 tipos diferentes de geometrias: barra cilíndrica sem entalhe, barra cilíndrica com entalhe (R = 1, 2, 3 mm) e corpos de prova SE(B) com trinca inicial profunda e rasa. Para o processo de calibração das propriedades mecânicas foram gerados modelos de elementos finitos, utilizando elementos sólidos 30 com 8 nós (C3D8), que representam de forma adequada a geometria e as propriedades dos corpos de prova testados. Para calibrar o comportamento elastoplástico e iniciação do dano, utilizou-se a resposta experimental e numérica obtida para as amostras de barra cilíndrica com e sem entalhe; e, para a calibração da evolução do dano, foram utilizadas as respostas obtidas para os espécimes SEB de trincas profundas e rasa. Este modelo calibrado foi capaz de recuperar as respostas experimentais dos corpos de prova SE(B), o que valida o uso do material caracterizado em uma estrutura complexa. Uma vez calibradas as propriedades mecânicas, foram obtidos os fatores do critério SMSC representados pela equação ....... , e, a condição de dano que é representada pelo deslocamento na falha .... e o fator de amolecimento exponencial .... . Depois, o material totalmente caracterizado foi aplicado em dois dutos que possuem trinca elíptica circunferencial inicial externa; sendo o primeiro tubo com trinca superficial e o segundo com trinca profunda. Finalmente, ambos os tubos foram submetidos a cargas de tensão para prever o comportamento do dano dúctil, obtendo a carga necessária para o início do crescimento da trinca e a evolução da falha.
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BOATENG, KINGSLEY A. "STUDIES ON ARABIDOPSIS PROTEINS REQUIRED FOR THE ESTABLISHMENT AND RELEASE OF SISTER CHROMATID COHESION." Miami University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=miami1185209243.
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Farmer, Sarah Elizabeth. "The role of the Smc5/6 complex in budding yeast meiosis." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445168.
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Kirk, Jacob Daniel. "Understanding the roles of the Smc5/6 complex on meiotic recombination." Thesis, University of Sussex, 2017. http://sro.sussex.ac.uk/id/eprint/68211/.
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During meiotic cell division, the formation of chiasmata is required for the segregation of homologous chromosomes. This involves the formation of a programmed series of double strand breaks and repair by homologous recombination to form crossovers within the chromosomes. This process is highly regulated to ensure the timely formation of interhomolog linkages, which are normally repressed by the mitotic repair pathways. A protein complex of particular interest here is Smc5/6, which is closely related to two complexes with a fundamental role controlling chromosome structure (cohesin and condensin). In the absence of the Smc5/6 complex, cells are unable to separate their chromosomes efficiently during meiosis, resulting in a ‘cut phenotype'; this is thought to be due to major aberrations in the formation and resolution of joint molecule intermediates throughout meiotic prophase. Here, I characterize the aberration in the formation of recombination intermediates in smc5/6-depleted cells in order to infer functions of the Smc5/6 complex in regulating recombination intermediates. Using the well-characterised DNA double strand break hotspot HIS4LEU2, I show that depletion of the Smc5/6 complex rescues joint molecule formation in a zmm repair pathway mutant. To understand the timing of Smc5/6 complex function during strand invasion, I analyse the genetic interactions between two recA orthologues and cohesin, all of which promote the orderly formation of recombination events between homologous chromosomes. Collectively, the findings suggest that the Smc5/6 complex stabilizes early recombination intermediates between homologous DNA substrates thereby imposing an interhomolog repair fate. I analyse the formation of repair intermediates in the absence of cohesin, and demonstrate that the role of the Smc5/6 complex in interhomolog repair bias is independent of the presence of cohesin, which is normally considered a fundamental factor in the establishment of repair bias.
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Tesfamariam, Berhane Ghebreslasie. "Assessing the sustainability of Saving and Micro-Credit Programme (SMCP), Eritrea." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/1963.
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Ferreira, Rita Marisa Nogueira. "Terameprocol effect in the proliferation and apoptosis of SMCs in PAH." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10867.
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Mestrado em Bioquímica ClínicaA hipertensão arterial pulmonar (HAP) é uma doença rara e letal, caracterizada pela remodelação da vasculatura pulmonar, devido a uma proliferação celular excessiva e diminuição da apoptose. Estas alterações levam ao aumento da resistência e pressão arterial pulmonares, culminando em insuficiência cardíaca direita. O tratamento atual é limitado, não oferecendo uma cura e, portanto, é necessária mais investigação para encontrar novos alvos terapêuticos. Neste contexto, a via da survivina, uma molécula que inibe a apoptose e promove a proliferação e cujos níveis estão aumentados na HAP, parece promissora. O objetivo deste trabalho foi avaliar o efeito do terameprocol, um antagonista da survivina, na proliferação e apoptose de células musculares lisas na HAP. Foi utilizado o modelo experimental de HAP induzida por monocrotalina (MCT). Ratos Wistar foram injetados com MCT (60 mg/kg, sc) para a indução da doença e, após 21 dias foram sacrificados, o coração e os pulmões foram removidos e a artéria pulmonar do lobo superior esquerdo foi dissecada. A adventícia e íntima foram removidas da artéria e as células musculares lisas da média foram isoladas através de um método enzimático. Foi realizada uma cultura primária de células musculares lisas que foram tratadas com diferentes concentrações de terameprocol. Em seguida, foram realizados ensaios para avaliar a apoptose (TUNEL) e proliferação (BrdU e exclusão por trypan blue) das células musculares lisas. Os resultados mostraram que o terameprocol inibe a proliferação e induz a apoptose das células musculares lisas da artéria pulmonar de ratos com HAP induzida pela MCT, sugerindo que a via da survivina pode constituir um novo alvo terapêutico a ser investigado na HAP.
Pulmonary arterial hypertension (PAH) is a rare and lethal disease, characterized by remodeling of the pulmonary vasculature due to excessive cellular proliferation and decreased apoptosis. These alterations lead to increased pulmonary arterial resistance and pressure, culminating in right heart failure. The current treatment is limited, not affording a cure and thus, more research is needed to find new therapeutic targets. In this context, targeting survivin, a molecule that inhibits apoptosis and promotes proliferation and reported to be increased in PAH, seems promising. The aim of this work was to evaluate the effect of terameprocol, an antagonist of survivin, in the proliferation and apoptosis of smooth muscle cells in PAH. We used the experimental model of PAH induced by monocrotaline (MCT). Wistar rats were injected with MCT (60 mg/kg, sc) to induce the disease and after 21 days, they were euthanized, their heart and lungs were removed and the pulmonary artery from the left upper lobe was dissected. The adventitia and intima were removed from the artery and the smooth muscle cells from the media were isolated through an enzymatic method. The resultant primary cultures of smooth muscle cells were treated with different concentrations of terameprocol. Then, assays were performed to evaluate smooth muscle cell apoptosis (TUNEL assay) and proliferation (BrdU and trypan blue exclusion assays). The results showed that terameprocol inhibits proliferation and promotes apoptosis of pulmonary artery smooth muscle cells from rats with MCT-induced PAH, suggesting that survivin pathway can be seen as a new therapeutic target to be explored in PAH.
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Pattanaporkratana, Apichart. "Textures and interactions between vortices in the two-dimensional XY field of freely suspended SmC and SmC* liquid crystal films." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3273732.
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Theodore, George. "Regulation of SMC/MUC4 Expression in the Airway." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/364.
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MUC4 is a heterodimeric mucin glycoprotein expressed in the epithelia of tissues. Previous studies in our laboratory demonstrated that MUC4 protein expression is regulated by exogenous growth factors and that MUC4 is found in complex with the receptor tyrosine kinase ErbB2. MUC4 protein expression in airway epithelia was evaluated using molecular biology techniques. The impact of the protein on ErbB2 activation was evaluated post mechanical wounding of airway epithelia, and upon MUC4 RNA silencing. MUC4 levels were increased with exposure to the differentiating agent retinoic acid and decreased upon exposure to epidermal growth factor, a proliferative agent. In the absence of MUC4, ErbB2 phosphorylation was diminished. These results support the hypothesis that MUC4 expression is enhanced during differentiation of epithelia. Furthermore these findings provide evidence for an additional level of ErbB regulation in airway injury and subsequent epithelial wound healing.
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Odenberger, Torbjörn. "Compression Moulding of SMC, Visualisation and Inverse Modelling." Licentiate thesis, Luleå, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-16860.
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Before presenting the Sheet Moulding Compound (SMC) process, which is the primarily focus of this work, a literature survey is carried out to deal with fibre reinforced polymer composites in general. Then the first part of this work is presented and is primarily focused on experimental visualisation of the flow during mould closure of SMC. Circular plates are manufactured with industry scale equipment at close to production conditions. Special attention is given to the advancing flow front, for which the full complexity is captured by means of continuous high resolution close-up monitoring. From the experimental visualisation of the flow front, three phases are defined, namely squish, flow, and boiling. During the initial phase, squish, outer layers do not remain outer layers, the actual flow is very complex and air is likely to be entrapped. The governing process parameters during this phase are mould temperature, mould closing speed and amount of preheating in the mould. During the second phase, flow, the flow is stable and seemingly viscous. During the last phase, boiling, bubbles are observed in the low pressure region at the flow front, favouring the void content both internally and on the surface. Based on a chemical analysis including mass spectrometry and thermogravimetry, the gas is probably styrene. In the second part it is investigated if an inverse modelling approach by proportional regularisation can be applied to mimic the pressure distribution during compression moulding of SMC. The process is simulated with Computational Fluid Dynamics and the mastered parameter, the viscosity of the SMC, is allowed to vary as a function of time. A grid refinement study of two ways to model the process and for three fictitious pressure scenarios yields that the suggested approach work very well and that the numerical errors can be minimised as desired. Finally a validation process is carried out showing that to get quantitative agreements of the whole pressure field more advanced viscosity models must be used. In order to verify the inverse modelling system have to important errors are studied. Firstly the error between calculated and experimental pressure, secondly the discretisation error due to solving the problem for many small volumes. Both have to be minimized and the later is studied with Richardson's extrapolation. The conclusions are that the initial guess is very important for predictions in the beginning of the simulation.Godkänd; 2005; 20070108 (haneit)
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Odenberger, Torbjörn. "Compression moulding of SMC, visualisation and inverse modelling /." Luleå : Luleå University of Technology, 2005. http://epubl.luth.se/1402-1757/2005/34.
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Moghraby, Jeelan Salah. "Analysis of the human Spr18 SMC-like protein." Thesis, University of Sussex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368280.
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Ribeiro, Susana Abreu. "Structural and functional mapping of the vertebrate centromere." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4653.
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Mitosis is the shortest phase of the cell cycle but visually the most outstanding. The key goal of mitosis is to accurately drive chromosome segregation. On one hand, DNA has to be condensed into characteristically shaped chromosomes. On the other hand, a very specialized structure needs to be built to conduct segregation, the mitotic spindle which is composed of microtubules organized into an antiparallel array between the two poles. The interaction between microtubules and chromosomes occurs at the kinetochore, a macromolecular complex assembled in mitosis at the centromere. The centromere/kinetochore monitors proper spindle microtubule attachment to each of the chromosomes, aligning them at the metaphase plate and also ensuring that chromosome segregation happens in perfect synchrony. Although centromeres are present in all eukaryotes, their basic structure and chromatin folding are still poorly understood. One of the aims of my work was to understand the function of the condensin complex specifically at the centromere during mitosis. Condensin I and II are pentameric protein complexes that are among the most abundant components of mitotic chromosomes. I have shown that condensin is important to confer stiffness to the innercentromeric chromatin once spindle microtubules interact with kinetochores in metaphase. Labile inner-centromeric regions delay mitotic progression by altering microtubule-kinetochore attachments and/or dynamics with a consequent increase in levels of Mad2 checkpoint protein bound to kinetochores. In the absence of condensin, kinetochores perform prominent “excursions” toward the poles trailing behind a thin thread of chromatin. These excursions are reversible suggesting that the centromeric chromatin behaves like an elastic polymer. During these excursions I noticed that only the inner centromeric chromatin was subjected to reversible deformations while the kinetochores (inner and outer plates) remained mostly unaltered. This suggested that the centromeric chromatin part of the inner kinetochore plate was organised differently from the subjacent chromatin. I went on to investigate how the centromeric chromatin is organised within the inner kinetochore domain. Super-resolution analyses of artificially unfolded centromeric chromatin revealed novel details of the vertebrate inner kinetochore domain. All together, the data allowed me to propose a new model for the centromeric chromatin folding: CENP-A domains are interspersed with H3 domains arranged in a linear segment that forms planar sinusoidal waves distributed in several layers. Both CENP-A and H3 arrays face the external surface, building a platform for CCAN proteins. CENP-C binds to more internal CENP-A blocks thereby crosslinking the layers. This organization of the chromatin explains the localisation and similar compliant behaviour that CENP-A and CENP-C showed when kinetochores come under tension. Other kinetochore proteins (the KMN complex) assemble in mitosis on top of the CCAN and bind microtubules. KMN binding may confer an extra degree of stability to the kinetochore by crosslinking CENP-C either directly or indirectly. My work and the testable model that I have developed for kinetochore organization provide a fundamental advance in our understanding of this specialized chromosomal substructure.
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Irmisch, Anja. "Investigating the role of the Smc5/6 complex when replication folks stall." Thesis, University of Sussex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494937.
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Structural maintenance of chromosome (Smc) complexes have key functions in chromosome formation and segregation. Eukaryotes possess three essential Smc complexes: cohesin (Smc 1/3) which facilitates sister chromatid cohesion, condensin (Smc2/4), which facilitates chromosome condensation and segregation and Smc5/6, the less well-understood third complex. The Smc5/6 heterodimer interacts with the non-Smc proteins Nse1 to Nse6 to form a functional complex, implicated in DNA repair by homologous recombination (HR) and the segregation of repetitive DNA such as ribosomal DNA repeats. Hypomorphic complex mutants are HR defective and loss of Smc5/6 complex functions results in global chromosome fragmentation and missegregation.
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Whitwood, Jennifer. "Using mating-type switching to investigate Smc5/6 function in Schizosaccharomyces pombe." Thesis, University of Sussex, 2014. http://sro.sussex.ac.uk/id/eprint/48308/.
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The essential Smc5/6 complex is structurally related to cohesin and condensin. It is required for homologous recombination (HR), rDNA stability and telomere maintenance. In Schizosaccharomyces pombe, two hypomorphic smc6 mutants, smc6-X and smc6-74, haven been shown to be deficient in HR-dependent processing of collapsed replication forks. Collapsed replication forks can generate single-ended DNA double strand breaks (se-DSB) which require HR to restore replication. In this study the requirement for Smc5/6 at a site-specific se-DSB at the mating-type locus and in the mating-type switch process were analysed. In S.pombe mating-type switching occurs over two S phases; in the first S phase replication fork stalling at mat1 leads to an imprint, which is converted to an se-DSB during the next S phase. This initiates the copying of the donor cassette using HR. In the absences of donors the sister chromatid is used for repair. Mating-type switching analysis showed that snc6-74 had a defect in switching dependent on the genotype of the smc6-74 parent. Both smc6 mutants had reduced viability in the absence of donors, consistent with a defect in HR repair of an se-DSB. analysis in an inducible system (Holmes et al., 2005) showed that in response to a se-DSB Rad52 foci appeared with wild type kinetics but the smc6 mutants delayed entry into mitosis for approximately 2hrs, dependent on the DNA damage checkpoint kinase Chk1. In order to test whether this delay facilitated rescue by a converging replication fork a novel inducible converged fork (cf) DSB system was developed. The cf-DSB required HR and the RecQ helicase Rqh1 for repair but did not require Mus81. The converging fork rescued smc6-74 but not smc6-X showing Smc5/6 to be required for repair of both types of replication-associated DSBs.
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McGregor, Grant Alexander. "Investigation into the role of the SMC5/6 complex in human cells." Thesis, University of Sussex, 2017. http://sro.sussex.ac.uk/id/eprint/67537/.
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The Structural Maintenance of Chromosome (SMC) family of proteins are required to regulate almost all aspects of chromosome biology and are critical for genomic stability. The SMC5/6 complex, a member of this family, is composed of two SMC heterodimers and six additional Non-SMC Elements 1-6. The components of SMC5/6 possess activities including ATPases, ubiquitin and SUMO ligases. SMC5/6 is required in homologous recombination and for accurate chromosome segregation. Loss of SMC5/6 is lethal in yeasts, embryonic lethal in mice and mutations in NSMCE2 leads to primordial dwarfism and insulin resistance. This thesis focuses on a mutation in NSMCE3, found in American and Dutch families, that results in a novel chromosomal breakage syndrome characterized by fatal pulmonary disease. Another focus is the development, execution and validation of a microscopy based synthetic sick/lethal screen using cells with knockdown of NSMCE4a. Studies of SMC5/6 in yeasts predict that compromising SMC5/6 function would lead to a dependence on other DNA repair pathways. The results combined with patient data confirm that SMC5/6 is important in the absence of repair by non-homologous end joining and is particularly important under conditions of replication stress.