The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Ingrid R Vetter - One of the best experts on this subject based on the ideXlab platform.
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crystallization and preliminary X Ray Analysis of human rcc1 the regulator of chromosome condensation
Acta Crystallographica Section D-biological Crystallography, 1999Co-Authors: Louis Renault, Nicolas Nassar, Michel Roth, Alfred Wittinghofer, Ingrid R VetterAbstract:RCC1, the regulator of chromosome condensation, is the guanine nucleotide-eXchange factor (GEF) of the GTP-binding protein Ran. Its GEF activity on Ran makes it a key element in nucleo-cytoplasmic transport and cell-cycle regulation. Crystals of human RCC1 suitable for X-Ray Analysis have been obtained using the seeding technique in hanging drops with sodium citrate as a precipitant. The crystals diffract to 1.7 A at 100 K and belong to the space group P1, with unit-cell parameters a = 49.5, b = 84.3, c = 84.9 A, α = 113.0, β = 103.9,γ = 103.3°. The Matthews parameter (Vm) and the self-rotation function are consistent with three molecules in the unit cell, which is confirmed by the averaged single isomorphous replacement (SIR) electron-density map.
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crystallization and preliminary X Ray Analysis of human rcc1 the regulator of chromosome condensation
Acta Crystallographica Section D-biological Crystallography, 1999Co-Authors: Louis Renault, Nicolas Nassar, Michel Roth, Alfred Wittinghofer, Ingrid R VetterAbstract:RCC1, the regulator of chromosome condensation, is the guanine nucleotide-eXchange factor (GEF) of the GTP-binding protein Ran. Its GEF activity on Ran makes it a key element in nucleo-cytoplasmic transport and cell-cycle regulation. Crystals of human RCC1 suitable for X-Ray Analysis have been obtained using the seeding technique in hanging drops with sodium citrate as a precipitant. The crystals diffract to 1.7 A at 100 K and belong to the space group P1, with unit-cell parameters a = 49.5, b = 84.3, c = 84.9 A, α = 113.0, β = 103.9,γ = 103.3°. The Matthews parameter (Vm) and the self-rotation function are consistent with three molecules in the unit cell, which is confirmed by the averaged single isomorphous replacement (SIR) electron-density map.
Andrew R Liddle - One of the best experts on this subject based on the ideXlab platform.
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the Xmm cluster survey X Ray Analysis methodology
Monthly Notices of the Royal Astronomical Society, 2011Co-Authors: E J Lloyddavies, Nicola Mehrtens, Kathy A Romer, Matt Hilton, Mark Hosmer, M Davidson, Kivanc Sabirli, R G Mann, Andrew R LiddleAbstract:The XMM Cluster Survey (XCS) is a serendipitous search for galaXy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-Ray scaling relations. In this paper we describe the data processing methodology applied to the 5776 XMM observations used to construct the current XCS source catalogue. A total of 3675 > 4σ cluster candidates with >50 background-subtracted X-Ray counts are eXtracted from a total non-overlapping area suitable for cluster searching of 410 deg2. Of these, 993 candidates are detected with >300 background-subtracted X-Ray photon counts, and we demonstrate that robust temperature measurements can be obtained down to this count limit. We describe in detail the automated pipelines used to perform the spectral and surface brightness fitting for these candidates, as well as to estimate redshifts from the X-Ray data alone. A total of 587 (122) X-Ray temperatures to a typical accuracy of <40 (<10) per cent have been measured to date. We also present the methodology adopted for determining the selection function of the survey, and show that the eXtended source detection algorithm is robust to a range of cluster morphologies by inserting mock clusters derived from hydrodynamical simulations into real XMMimages. These tests show that the simple isothermal β-profiles is sufficient to capture the essential details of the cluster population detected in the archival XMM observations. The redshift follow-up of the XCS cluster sample is presented in a companion paper, together with a first data release of 503 optically confirmed clusters.
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the Xmm cluster survey X Ray Analysis methodology
arXiv: Cosmology and Nongalactic Astrophysics, 2010Co-Authors: E J Lloyddavies, Nicola Mehrtens, Kathy A Romer, Matt Hilton, Mark Hosmer, M Davidson, Kivanc Sabirli, R G Mann, Andrew R LiddleAbstract:The XMM Cluster Survey (XCS) is a serendipitous search for galaXy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-Ray scaling relations. In this paper we describe the data processing methodology applied to the 5,776 XMM observations used to construct the current XCS source catalogue. A total of 3,675 > 4-sigma cluster candidates with > 50 background-subtracted X-Ray counts are eXtracted from a total non-overlapping area suitable for cluster searching of 410 deg^2. Of these, 993 candidates are detected with > 300 background-subtracted X-Ray photon counts, and we demonstrate that robust temperature measurements can be obtained down to this count limit. We describe in detail the automated pipelines used to perform the spectral and surface brightness fitting for these candidates, as well as to estimate redshifts from the X-Ray data alone. A total of 587 (122) X-Ray temperatures to a typical accuracy of < 40 (< 10) per cent have been measured to date. We also present the methodology adopted for determining the selection function of the survey, and show that the eXtended source detection algorithm is robust to a range of cluster morphologies by inserting mock clusters derived from hydrodynamical simulations into real XMM images. These tests show that the simple isothermal beta-profiles is sufficient to capture the essential details of the cluster population detected in the archival XMM observations. The redshift follow-up of the XCS cluster sample is presented in a companion paper, together with a first data release of 503 optically-confirmed clusters.
Matt Hilton - One of the best experts on this subject based on the ideXlab platform.
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the Xmm cluster survey X Ray Analysis methodology
Monthly Notices of the Royal Astronomical Society, 2011Co-Authors: E J Lloyddavies, Nicola Mehrtens, Kathy A Romer, Matt Hilton, Mark Hosmer, M Davidson, Kivanc Sabirli, R G Mann, Andrew R LiddleAbstract:The XMM Cluster Survey (XCS) is a serendipitous search for galaXy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-Ray scaling relations. In this paper we describe the data processing methodology applied to the 5776 XMM observations used to construct the current XCS source catalogue. A total of 3675 > 4σ cluster candidates with >50 background-subtracted X-Ray counts are eXtracted from a total non-overlapping area suitable for cluster searching of 410 deg2. Of these, 993 candidates are detected with >300 background-subtracted X-Ray photon counts, and we demonstrate that robust temperature measurements can be obtained down to this count limit. We describe in detail the automated pipelines used to perform the spectral and surface brightness fitting for these candidates, as well as to estimate redshifts from the X-Ray data alone. A total of 587 (122) X-Ray temperatures to a typical accuracy of <40 (<10) per cent have been measured to date. We also present the methodology adopted for determining the selection function of the survey, and show that the eXtended source detection algorithm is robust to a range of cluster morphologies by inserting mock clusters derived from hydrodynamical simulations into real XMMimages. These tests show that the simple isothermal β-profiles is sufficient to capture the essential details of the cluster population detected in the archival XMM observations. The redshift follow-up of the XCS cluster sample is presented in a companion paper, together with a first data release of 503 optically confirmed clusters.
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the Xmm cluster survey X Ray Analysis methodology
arXiv: Cosmology and Nongalactic Astrophysics, 2010Co-Authors: E J Lloyddavies, Nicola Mehrtens, Kathy A Romer, Matt Hilton, Mark Hosmer, M Davidson, Kivanc Sabirli, R G Mann, Andrew R LiddleAbstract:The XMM Cluster Survey (XCS) is a serendipitous search for galaXy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-Ray scaling relations. In this paper we describe the data processing methodology applied to the 5,776 XMM observations used to construct the current XCS source catalogue. A total of 3,675 > 4-sigma cluster candidates with > 50 background-subtracted X-Ray counts are eXtracted from a total non-overlapping area suitable for cluster searching of 410 deg^2. Of these, 993 candidates are detected with > 300 background-subtracted X-Ray photon counts, and we demonstrate that robust temperature measurements can be obtained down to this count limit. We describe in detail the automated pipelines used to perform the spectral and surface brightness fitting for these candidates, as well as to estimate redshifts from the X-Ray data alone. A total of 587 (122) X-Ray temperatures to a typical accuracy of < 40 (< 10) per cent have been measured to date. We also present the methodology adopted for determining the selection function of the survey, and show that the eXtended source detection algorithm is robust to a range of cluster morphologies by inserting mock clusters derived from hydrodynamical simulations into real XMM images. These tests show that the simple isothermal beta-profiles is sufficient to capture the essential details of the cluster population detected in the archival XMM observations. The redshift follow-up of the XCS cluster sample is presented in a companion paper, together with a first data release of 503 optically-confirmed clusters.
Louis Renault - One of the best experts on this subject based on the ideXlab platform.
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crystallization and preliminary X Ray Analysis of human rcc1 the regulator of chromosome condensation
Acta Crystallographica Section D-biological Crystallography, 1999Co-Authors: Louis Renault, Nicolas Nassar, Michel Roth, Alfred Wittinghofer, Ingrid R VetterAbstract:RCC1, the regulator of chromosome condensation, is the guanine nucleotide-eXchange factor (GEF) of the GTP-binding protein Ran. Its GEF activity on Ran makes it a key element in nucleo-cytoplasmic transport and cell-cycle regulation. Crystals of human RCC1 suitable for X-Ray Analysis have been obtained using the seeding technique in hanging drops with sodium citrate as a precipitant. The crystals diffract to 1.7 A at 100 K and belong to the space group P1, with unit-cell parameters a = 49.5, b = 84.3, c = 84.9 A, α = 113.0, β = 103.9,γ = 103.3°. The Matthews parameter (Vm) and the self-rotation function are consistent with three molecules in the unit cell, which is confirmed by the averaged single isomorphous replacement (SIR) electron-density map.
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crystallization and preliminary X Ray Analysis of human rcc1 the regulator of chromosome condensation
Acta Crystallographica Section D-biological Crystallography, 1999Co-Authors: Louis Renault, Nicolas Nassar, Michel Roth, Alfred Wittinghofer, Ingrid R VetterAbstract:RCC1, the regulator of chromosome condensation, is the guanine nucleotide-eXchange factor (GEF) of the GTP-binding protein Ran. Its GEF activity on Ran makes it a key element in nucleo-cytoplasmic transport and cell-cycle regulation. Crystals of human RCC1 suitable for X-Ray Analysis have been obtained using the seeding technique in hanging drops with sodium citrate as a precipitant. The crystals diffract to 1.7 A at 100 K and belong to the space group P1, with unit-cell parameters a = 49.5, b = 84.3, c = 84.9 A, α = 113.0, β = 103.9,γ = 103.3°. The Matthews parameter (Vm) and the self-rotation function are consistent with three molecules in the unit cell, which is confirmed by the averaged single isomorphous replacement (SIR) electron-density map.
Carlo Prati - One of the best experts on this subject based on the ideXlab platform.
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environmental scanning electron microscopy connected with energy dispersive X Ray Analysis and raman techniques to study proroot mineral trioXide aggregate and calcium silicate cements in wet conditions and in real time
Journal of Endodontics, 2010Co-Authors: Maria Giovanna Gandolfi, Kirsten Van Landuyt, Paola Taddei, Enrico Modena, Bart Van Meerbeek, Carlo PratiAbstract:Introduction: Pro Root mineral trioXide aggregate (MTA) and calcium silicate cements are able to set in a moist environment. The aim of the study was to eXamine the surface structure and composition of a cement paste under wet conditions and in real time during setting by environmental scanning electron microscopy connected with energy dispersive X-Ray Analysis (ESEM-EDX) and micro-Raman techniques. Methods: White Pro Root MTA and eXperimental white tetrasilicate cement (wTC) and wTC containing bismuth oXide (wTC-Bi) were studied. Cement disks were analyzed 10 minutes after powder-liquid miXing (freshly prepared samples) and after immersion in Dulbecco phosphate-buffered saline at 37 degrees C for 24 hours (24-hour-aged samples). Results: Freshly prepared wet cements at ESEM-EDX eXposed an irregular surface (displaying calcium, silicon, aluminum, chlorine refleXes, and bismuth traces in MTA and wTC-Bi) with needle-like and cubic-heXagonal shaped crystals. Aggregates of spheroidal Ca-P-rich crystals (spherulites) appeared on the surface of 24-hour-aged samples. The starting unhydrated powders displayed the typical Raman bands of Portland cement components: alite, belite, and calcium sulfate (only as anhydrite in MTA and as both anhydrite and gypsum in wTC and wTC-Bi). MTA powder showed higher amount of calcium carbonate and lower quantities of anhydrite and higher crystallinity of the silicate component, leading to a slower hydration reaction. Products/markers of hydration reactions were present on fresh samples; ettringite formed on the surface of all the cements; calcium hydroXide (portlandite) was detected only on the surface of wTC, but no conclusion can be drawn on wTC-Bi and MTA because of the interference of bismuth oXide. Calcium phosphate and calcite/aragonite bands were detected on all 24-hour-aged cements; portlandite was no longer detected on wTC. Conclusions: ESEM and micro-Raman are powerful and suitable techniques to investigate endodontic calcium silicate hydrated cements in real time and in their humid state without inducing artifacts by sample preparation. The formation of apatite spherulites on calcium silicate cements might have clinical relevance. (J Endod 2010;36:851-857)
