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The SAURON project – XVIII. The integrated UV–line‐strength relations of early‐type galaxies
Bureau, Martin,Jeong, Hyunjin,Yi, Sukyoung K.,Schawinski, Kevin,Houghton, Ryan C. W.,Davies, Roger L.,Bacon, Roland,Cappellari, Michele,de Zeeuw, P. Tim,Emsellem, Eric,Falcó,n‐,Barroso, Je Blackwell Publishing Ltd 2011 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.414 No.3
<P><B>ABSTRACT</B></P><P>Using far‐ultraviolet (FUV) and near‐ultraviolet (NUV) photometry from guest investigator programmes on the <I>Galaxy Evolution Explorer</I> (<I>GALEX</I>) satellite, optical photometry from the MDM Observatory and optical integral‐field spectroscopy from SAURON, we explore the UV–line‐strength relations of the 48 nearby early‐type galaxies in the SAURON sample. Identical apertures are used for all quantities, avoiding aperture mismatch. We show that galaxies with purely old stellar populations show well‐defined correlations of the integrated FUV −<I>V</I> and FUV − NUV colours with the integrated Mg <I>b</I> and Hβ absorption line‐strength indices, strongest for FUV − NUV. Correlations with the NUV −<I>V</I> colour, Fe5015 index and stellar velocity dispersion σ are much weaker. These correlations put stringent constraints on the origin of the UV‐upturn phenomenon in early‐type galaxies and highlight its dependence on age and metallicity. In particular, despite recent debate, we recover the negative correlation between FUV −<I>V</I> colour and Mg line strength originally publicized by Burstein et al., which we refer to as the ‘Burstein relation’, suggesting a positive dependence of the UV upturn on metallicity. We argue that the scatter in the correlations is real and present mild evidence that a strong UV excess is preferentially present in slow‐rotating galaxies. We also demonstrate that most outliers in the correlations are galaxies with current or recent star formation, some at very low levels. We believe that this sensitivity to weak star formation, afforded by the deep and varied data available for the SAURON sample, explains why our results are occasionally at odds with other recent but shallower surveys. This is supported by the analysis of a large, carefully crafted sample of more distant early‐type galaxies from the Sloan Digital Sky Survey (SDSS), more easily comparable with current and future large surveys.</P>
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A redshifted codon-optimized firefly luciferase is a sensitive reporter for bioluminescence imaging
Caysa, Henrike,Jacob, Roland,Muther, Nadine,Branchini, Bruce,Messerle, Martin,Soling, Ariane Korean Society of Photoscience 2009 Photochemical & photobiological sciences Vol.8 No.1
Bioluminescence imaging has evolved as a powerful tool for monitoring biological processes in vivo. As transmission efficiency of light through tissue increases greatly for wavelengths above 600 nm we examined whether a redshifted codon-optimized firefly luciferase (${\lambda}_{max}$ = 615 nm) could be successfully employed as a sensitive reporter in mammalian cells. To this end, unmodified codon-optimized luciferase (${\lambda}_{max}$ = 557 nm) as well as the red-emitting S284T mutant luciferase were expressed simultaneously in human glioma cells in vitro as well as in quadriceps muscles of mice in vivo. We show here that activity of the redshifted enzyme in human glioma cell culture approached approximately one-fourth of that seen with the unmodified enzyme. In contrast, light emission by the red-emitting luciferase in vivo was generally more efficient than that produced by its unmodified counterpart, most likely due to reduced absorption of red light by tissue. The mean ratio of light emission produced by the redshifted luciferase to that of the unmodified enzyme in vivo was~3. Application of this new redshifted luciferase together with other optical reporters may be of considerable importance to biological research as it allows for imaging of deeper tissues as well as simultaneous monitoring of two molecular events in vitro and in vivo if appropriate filter sets are employed.
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Xiaojun Feng,Enyuan Wang,Jérôme Ganne,Roland Martin,Mark Jessell 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.3
High-grade (amphibolite–granulite facies) tectono-metamorphic domains in the Sefwi terrane of Ghana are separated from adjacent lower-grade (greenschist facies) greenstone belts by two main shear zones. The high-grade rocks presumably exhumed along the sinistral shear zones during the D2 ENE-WSW transtension (~2073 Ma). To better understand the role boundary conditions and the spatial relationship of faults play in the exhumation of partially molten lower crust in the Sefwi terrane, ten 3D thermomechanical models have been constructed. The results show that the normal component of velocity boundary conditions mainly controls the exhumation (8–10 km) of the lower crust along pre-existing faults, while the exhumation in the relay zones between faults is controlled by the obliquity between the applied extensional velocity vector and the vertical wall on which it is applied. The strike of the exhumation belt made of partially molten lower crust rocks in the relay zone is sub-orthogonal to the horizontal maximum stretching axis. The isostatic compensation from low-density upper mantle to overlying crust (thinning) is higher under transtension than under extension. The lower crust exhumation influenced by inherited shear zones (ductile) can be used to better understand the loci of the high-grade rocks in the Sefwi terrane. We suggest that the Kukuom-Juaboso domain composed of amphibolite–migmatite facies rocks probably resulted from the concentration of partially molten rocks in the relay zone between the Ketesso and Kenyase shear zones during the D2 ENE-WSW transtension. The two shear zones probably underwent two main stages for growth and maturation from the D1 to D2 phases. The regional exhumation of the high-grade rocks in the Sefwi terrane probably occurred within < 5 Ma.
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In-vitro performance and fracture strength of thin monolithic zirconia crowns
Paul Weigl,Anna Sander,Yanyun Wu,Roland Felber,Hans-Christoph Lauer,Martin Rosentritt 대한치과보철학회 2018 The Journal of Advanced Prosthodontics Vol.10 No.2
PURPOSE. All-ceramic restorations required extensive tooth preparation. The purpose of this in vitro study was to investigate a minimally invasive preparation and thickness of monolithic zirconia crowns, which would provide sufficient mechanical endurance and strength. MATERIALS AND METHODS. Crowns with thickness of 0.2 mm (group 0.2, n=32) or of 0.5 mm (group 0.5, n=32) were milled from zirconia and fixed with resin-based adhesives (groups 0.2A, 0.5A) or zinc phosphate cements (groups 0.2C, 0.5C). Half of the samples in each subgroup (n=8) underwent thermal cycling and mechanical loading (TCML)(TC: 5°C and 55°C, 2×3,000 cycles, 2 min/cycle; ML: 50 N, 1.2×106 cycles), while the other samples were stored in water (37°C/24 h). Survival rates were compared (Kaplan-Maier). The specimens surviving TCML were loaded to fracture and the maximal fracture force was determined (ANOVA; Bonferroni; α=.05). The fracture mode was analyzed. RESULTS. In both 0.5 groups, all crowns survived TCML, and the comparison of fracture strength among crowns with and without TCML showed no significant difference (P=.628). Four crowns in group 0.2A and all of the crowns in group 0.2C failed during TCML. The fracture strength after 24 hours of the cemented 0.2 mm-thick crowns was significantly lower than that of adhesive bonded crowns. All cemented crowns provided fracture in the crown, while about 80% of the adhesively bonded crowns fractured through crown and die. CONCLUSION. 0.5 mm thick monolithic crowns possessed sufficient strength to endure physiologic performance, regardless of the type of cementation. Fracture strength of the 0.2 mm cemented crowns was too low for clinical application.
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Jeong, Hyunjin,Yi, Sukyoung K.,Bureau, Martin,Davies, Roger L.,Falcó,n-Barroso, Jesú,s,van de Ven, Glenn,Peletier, Reynier F.,Bacon, Roland,Cappellari, Michele,de Zeeuw, Tim,Emsellem, Eric Blackwell Publishing Ltd 2009 Monthly notices of the Royal Astronomical Society Vol.398 No.4
<P>ABSTRACT</P><P>We present <I>Galaxy Evolution Explorer</I> far-ultraviolet (FUV) and near-ultraviolet (NUV) imaging of 34 nearby early-type galaxies from the SAURON representative sample of 48 E/S0 galaxies, all of which have ground-based optical imaging from the MDM Observatory. The surface brightness profiles of nine galaxies (≈26 per cent) show regions with blue UV−optical colours suggesting RSF. Five of these (≈15 per cent) show blue integrated UV–optical colours that set them aside in the NUV integrated colour–magnitude relation. These are objects with either exceptionally intense and localized NUV fluxes or blue UV−optical colours throughout. They also have other properties confirming they have had RSF, in particular Hβ absorption higher than expected for a quiescent population and a higher CO detection rate. This suggests that residual star formation is more common in early-type galaxies than we are used to believe. NUV blue galaxies are generally drawn from the lower stellar velocity dispersion (σ<SUB>e</SUB> < 200 km s<SUP>−1</SUP>) and thus lower dynamical mass part of the sample. We have also constructed the first UV Fundamental Planes and show that NUV blue galaxies bias the slopes and increase the scatters. If they are eliminated, the fits get closer to expectations from the virial theorem. Although our analysis is based on a limited sample, it seems that a dominant fraction of the tilt and scatter of the UV Fundamental Planes is due to the presence of young stars in preferentially low-mass early-type galaxies. Interestingly, the UV–optical radial colour profiles reveal a variety of behaviours, with many galaxies showing signs of RSF, a central UV-upturn phenomenon, smooth but large-scale age and metallicity gradients and in many cases a combination of these. In addition, FUV−NUV and FUV−<I>V</I> colours even bluer than those normally associated with UV-upturn galaxies are observed at the centre of some quiescent galaxies. Four out of the five UV-upturn galaxies are slow rotators. These objects should thus pose interesting challenges to stellar evolutionary models of the UV upturn.</P>
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The SAURON project – XXI. The spatially resolved UV–line strength relations of early‐type galaxies
Jeong, Hyunjin,Yi, Sukyoung K.,Bureau, Martin,Davies, Roger L.,Bacon, Roland,Cappellari, Michele,de Zeeuw, P. Tim,Emsellem, Eric,Falcó,n‐,Barroso, Jesú,s,Krajnović,, Davor,Kunts Blackwell Publishing Ltd 2012 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.423 No.2
<P><B>ABSTRACT</B></P><P>The unexpected rising flux of early‐type galaxies at decreasing ultraviolet (UV) wavelengths is a long‐standing mystery. One important observational constraint is the correlation between UV–optical colours and Mg<SUB>2</SUB> line strengths found by Burstein et al. The simplest interpretation of this phenomenon is that the UV strength is related to the Mg line strength. Under this assumption, we expect galaxies with larger Mg gradients to have larger UV colour gradients. By combining UV imaging from <I>GALEX</I>, optical imaging from MDM and SAURON integral‐field spectroscopy, we investigate the spatially resolved relationships between UV colours and stellar population properties of 34 early‐type galaxies from the SAURON survey sample. We find that galaxies with old stellar populations show tight correlations between the far‐UV (FUV) colours (FUV −<I>V</I> and FUV − NUV) and the Mg <I>b</I> index, Hβ index and metallicity [<I>Z</I>/H]. The equivalent correlations for the Fe5015 index, α‐enhancement [α/Fe] and age are present but weaker. We have also derived logarithmic internal radial colour, <I>measured</I> line strength and <I>derived</I> stellar population gradients for each galaxy and again found a strong dependence of the FUV −<I>V</I> and FUV − NUV colour gradients on both the Mg <I>b</I> line strength and the metallicity gradients for galaxies with old stellar populations. In particular, global gradients of Mg <I>b</I> and [<I>Z</I>/H] with respect to the UV colour [e.g. Δ(Mg <I>b</I>)/Δ(FUV − NUV) and Δ[<I>Z</I>/H]/Δ(FUV − NUV)] across galaxies are consistent with their local gradients within galaxies, suggesting that the global correlations also hold locally. From a simple model based on multiband colour fits of UV upturn and UV‐weak galaxies, we have identified a plausible range of parameters that reproduces the observed radial colour profiles. In these models, the centres of elliptical galaxies, where the UV flux is strong, are enhanced in metals by roughly 60 per cent compared to UV‐weak regions.</P>
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Structural engineering of nanoporous anodic aluminium oxide by pulse anodization of aluminium.
Lee, Woo,Schwirn, Kathrin,Steinhart, Martin,Pippel, Eckhard,Scholz, Roland,Gö,sele, Ulrich Nature Pub. Group 2008 Nature nanotechnology Vol.3 No.4
<P>Nanoporous anodic aluminium oxide has traditionally been made in one of two ways: mild anodization or hard anodization. The first method produces self-ordered pore structures, but it is slow and only works for a narrow range of processing conditions; the second method, which is widely used in the aluminium industry, is faster, but it produces films with disordered pore structures. Here we report a novel approach termed 'pulse anodization' that combines the advantages of the mild and hard anodization processes. By designing the pulse sequences it is possible to control both the composition and pore structure of the anodic aluminium oxide films while maintaining high throughput. We use pulse anodization to delaminate a single as-prepared anodic film into a stack of well-defined nanoporous alumina membrane sheets, and also to fabricate novel three-dimensional nanostructures.</P>
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