Sample records for luids lutu ehk
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1988-04-01
search Library /Reprint Deor.: renc Dept of Iimunology, Wasington, DC 20307-5100 Washington, DC: 20�-5100, Ba NAVE OF FNING, SPONSORING an )::Z C- S VBOL...released~~O into)int cultures \\luids wauheeigy na clox Mooc ~es hr ncaly ifeced 4(1 i) ith11 V- (pate IND20A~. second J~pas- sage)~ ~ ~ ~ ~ ~~~~~(l intill
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ERIC Educational Resources Information Center
Cohen, Arlene, Ed.
2006-01-01
This publication follows the tradition of publishing selected papers from PIALA annual conferences, however, for the first time, two PIALA conferences (PIALA 2004 and PIALA 2005) are published in one volume, containing papers from both events. Both conferences featured papers by local Micronesian and Pacific Islands experts, as well as presenters…
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Many-Body Effects on Optical Carrier Cooling in Intrinsic Semiconductors at Low Lattice Temperatures
2008-07-11
Fg, 78.40.Fy, 78.55.Cr I . INTRODUCTION It is well known that the optical properties of an atomic vapor are essentially determined by the properties...equal temperatures in the papers by Rupper et al.12 and by Sheik- Bahae et al.13 for both carriers and phonons cannot be applied to quasiequilibrium...2 + i 0 − 2e2 2 0 b 0 dk k2 rvck 21 − fek − fhk Eek + Ehk + i 02 − Eek + Ehk2 , 4 where 0 is the homogeneous
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Meléndez-Hernández, Mayra Gisela; Barrios, María Luisa Labra; Orozco, Esther; Luna-Arias, Juan Pedro
2008-12-23
Entamoeba histolytica is a professional phagocytic cell where the vacuolar ATPase plays a key role. This enzyme is a multisubunit complex that regulates pH in many subcellular compartments, even in those that are not measurably acidic. It participates in a wide variety of cellular processes such as endocytosis, intracellular transport and membrane fusion. The presence of a vacuolar type H+-ATPase in E. histolytica trophozoites has been inferred previously from inhibition assays of its activity, the isolation of the Ehvma1 and Ehvma3 genes, and by proteomic analysis of purified phagosomes. We report the isolation and characterization of the Ehvma2 gene, which encodes for the subunit B of the vacuolar ATPase. This polypeptide is a 55.3 kDa highly conserved protein with 34 to 80% identity to orthologous proteins from other species. Particularly, in silico studies showed that EhV-ATPase subunit B displays 78% identity and 90% similarity to its Dictyostelium ortholog. A 462 bp DNA fragment of the Ehvma2 gene was expressed in bacteria and recombinant polypeptide was used to raise mouse polyclonal antibodies. EhV-ATPase subunit B antibodies detected a 55 kDa band in whole cell extracts and in an enriched fraction of DNA-containing organelles named EhkOs. The V-ATPase subunit B was located by immunofluorescence and confocal microscopy in many vesicles, in phagosomes, plasma membrane and in EhkOs. We also identified the genes encoding for the majority of the V-ATPase subunits in the E. histolytica genome, and proposed a putative model for this proton pump. We have isolated the Ehvma2 gene which encodes for the V-ATPase subunit B from the E. histolytica clone A. This gene has a 154 bp intron and encodes for a highly conserved polypeptide. Specific antibodies localized EhV-ATPase subunit B in many vesicles, phagosomes, plasma membrane and in EhkOs. Most of the orthologous genes encoding for the EhV-ATPase subunits were found in the E. histolytica genome, indicating the conserved nature of V-ATPase in this parasite.
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VizieR Online Data Catalog: Extinction map towards the Galactic bulge (Chen+, 2013)
NASA Astrophysics Data System (ADS)
Chen, B.; Schultheis, M.; Jiang, B.; Gonzalez, O. A.; Robin, A. C.; Rejkuba, M.; Minniti, D.
2012-11-01
We combine the observations with the Besancon model of the Galaxy to investigate the variations of extinction along different lines of sight towards the inner Galactic bulge as a function of distance. The full results are listed in Table 1 and Table 2. These results will be also added into the BEAM calculator webpage (http://mill.astro.puc.cl/BEAM/calculator.php). For each position we give the E(J-Ks), E(H-Ks) as well as the corresponding sigma for each distance bin starting from 1 to 10kpc. (2 data files).
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A high-resolution geochronological and geochemical study on Aegean carbonate deposits, SW Turkey
NASA Astrophysics Data System (ADS)
Ünal-İmer, Ezgi; Uysal, I. Tonguç; Işık, Veysel; Zhao, Jian-Xin; Shulmeister, James
2014-05-01
Vein and breccia carbonates precipitated in highly fractured/faulted carbonate bedrock were investigated using high-resolution U-series geochronology, as well as through microstructural and geochemical studies including Sr-O-C isotope and REE element analyses. The study area (Kumlubük and Amos vein systems), located south of the town of Marmaris in SW Turkey, is a part of an active large-scale extensional system. Field studies show that the calcite veins generally occur sub-vertically and strike mostly NW and EW, in agreement with the regional N-S extensional stress regime. Microscopic observations indicate that the calcite veins formed through crack-seal mechanism, typically accompanied/initiated by intensive hydraulic fracturing of wall-rock evidenced by the presence of widespread breccia deposits. Vein textures are dominated by elongated, fibrous, and blocky calcites. Successive fracturing and layering of calcite with sharp contacts are traceable along the fluid inclusion bands occurring parallel to the wall rock boundary. In particular, inclusion trails aligned perpendicular to the wall-rock and calcite crystal elongation give information about the vein dilation (crack opening) vector and growth direction. High-resolution U-series dating (11-272 ka BP) and geochemical compositions of the vein and breccia samples were used to investigate the long-term behaviour as well as the general identity of the CO2-bearing fluids within deformed crust. The seismic nature of calcite veining is further assessed by stable isotopic ratio (δ18O and δ13C) plots against vein depths (distance from the wall-rock). The average δ18OPDBvalue for Kumlubük veins is -3.79o, while Amos has an average value of -4.05o. Similarly, average carbon isotope ratio (-8.30o) of the Kumlubük veins is slightly higher than that is observed for the Amos veins (-9.66o). Isotopic compositions are interpreted to reflect cyclic (or episodic) CO2 variations. This suggests the presence of several fluid sources and mechanisms (e.g. luid-rock interaction) indicating the significance of pressure and temperature controls on the evolution of the CO2-bearing fluid system. Sr-isotope ratios (87Sr/86Sr: 0.7082-0.7085) in combination with REE compositions are used to trace fluid sources. REE data of the veins from both regions show typical seawater signatures with distinct negative Ce and positive Y anomalies, which corresponds well with the REE composition of the host limestone. While majority of the samples show similar PAAS-normalised REE variations, some of the veins further display positive Eu anomalies, which could be indicative of contribution from a deeply derived, hot, and reduced fluid component.
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Near-infrared reddening of extra-galactic giant molecular clouds in a face-on geometry
NASA Astrophysics Data System (ADS)
Kainulainen, J.; Juvela, M.; Alves, J.
2008-04-01
Aims: We describe the near-infrared reddening signature of giant molecular clouds (GMCs) in external galaxies. In particular, we examine the EJ-H and EH-K color excesses and the effective extinction law observed in discrete GMC regions. We also study the effect of the relative scale height of the GMC distribution to the color excesses, and to the observed mass function of GMCs when the masses are derived using color excess as a linear estimator of mass. Methods: We performed Monte Carlo radiative transfer simulations with 3D models of stellar radiation and clumpy dust distributions, resembling a face-on geometry. The scattered light is included in the models, and near-infrared color maps were calculated from the simulated data. We performed the simulations with different scale heights of GMCs and compared the color excesses and attenuation of light in different geometries. We extracted GMCs from the simulated color maps and compared the mass functions to the input mass functions. Results: The effective near-infrared reddening law, i.e. the ratio EJ-H/EH-K, has a value close to unity in GMC regions. The ratio depends significantly on the relative scale height of GMCs, ξ, and for ξ values 0.1...0.75, we find the typical ratios of 0.6...1.1. The effective extinction law turns out to be very flat in GMC regions. We find the ratios of apparent extinctions of AH^a/AKa = 1.35...1.55 and AJ^a/AHa = 1.15. The effect of the scattered flux on the effective reddening law, as well as on the effective extinction law, is significant. Regarding the GMC mass function, we find no correlation between the input and observed slopes of the mass functions. Instead, the observed slope reflects the parameter ξ and the dynamical range of the mass function. As the observed slope depends on the geometric parameters, which are not known, it is not possible to constrain the slope of the mass function using this technique. We estimate that only a fraction of 10...20% of the total mass of GMCs is recovered, if the observed color excess values are transformed to masses using the Galactic reddening law. In the case of individual clouds, the fraction can vary between ~0...50%.
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Serpentinite Carbonation in the Pollino Massif (southern Italy) for CO2 Sequestration
NASA Astrophysics Data System (ADS)
Carmela Dichicco, Maria; Mongelli, Giovanni; Paternoster, Michele; Rizzo, Giovanna
2015-04-01
Anthropogenic gas emissions are projected to change future climates with potentially nontrivial impacts (Keller et al., 2008 and references therein) and the impacts of the increased CO2 concentration are, among others, the greenhouse effect, the acidification of the surface of the ocean and the fertilization of ecosystems (e.g. Huijgen and Comans, 2003). Geologic Sequestration into subsurface rock formations for long-term storage is part of a process frequently referred to as "carbon capture and storage" or CCS. A major strategy for the in situ geological sequestration of CO2 involves the reaction of CO2 with Mg-silicates, especially in the form of serpentinites, which are rocks: i) relatively abundant and widely distributed in the Earth's crust, and ii) thermodynamically convenient for the formation of Mg-carbonates (e.g., Brown et al., 2011). In nature, carbonate minerals can form during serpentinization or during hydrothermal carbonation and weathering of serpentinites whereas industrial mineral carbonation processes are commonly represented by the reaction of olivine or serpentine with CO2 to form magnesite + quartz ± H2O (Power et al., 2013). Mineral carbonation occurs naturally in the subsurface as a result of fluid-rock interactions within serpentinite, which occur during serpentinization and carbonate alteration. In situ carbonation aims to promote these reactions by injecting CO2 into porous, subsurface geological formations, such as serpentinite-hosted aquifers. In the northern sector of the Pollino Massif (southern Italy) extensively occur serpentinites (Sansone et. al., 2012) and serpentinite-hosted aquifers (Margiotta et al., 2012); both serpentinites and serpentinite-hosted aquifers are the subject of a comprehensive project devoted to their possible use for in situ geological sequestration of CO2. The serpentinites derived from a lherzolitic and subordinately harzburgitic mantle, and are within tectonic slices in association with metadolerite dykes and medium to high-grade metamorphic rocks. Primary mantle minerals are olivine, clinopyroxene, orthopyroxene, and spinel whereas serpentine, magnetite, chlorite, and amphibole are pseudomorphic minerals. Olivine is replaced by serpentine forming a mesh texture and orthopyroxene is mostly altered to bastite. Water chemistry indicates serpentinites interact with meteoric water producing a Mg-HCO3 type water in a system open to CO2. Brown Jr., G.E., Calas, G., (2011) - Environmental mineralogy - understanding element behavior in ecosystems. Comptes Rendus Geoscience 343, 90-112. Huijgen W.JJ., and Comans R.N.J., (2003) - Carbon dioxide sequestrationby mineral carbonation. Report Number ECN-C-03-016, Energy research Centre of the Netherlands (ECN), Petten, the Netherlands. Keller PJ, Schmidt AD, Wittbrodt J, Stelzer EHK. (2008) - Reconstruction of zebrafish early embryonic development by scanned light sheet microscopy. Science 322: 1065-1069. Margiotta, S., Mongelli, G., Summa, V., Paternoster, M., Fiore S. (2012) - Trace element distribution and Cr(VI) speciation in Ca-HCO3 and Mg-HCO3 spring waters from the northern sector of the Pollino massif, southern Italy. Journal of Geochemical Exploration. Power I.M., Wilson S.A., Dipple G.M. (2013) - Serpentinite Carbonation for CO2 Sequestration. Elements, 9, 115-121. Sansone M.T.C., Prosser G., Rizzo G., Tartarotti P. (2012) - Spinel-peridotites of the Frido Unit ophiolites: evidence for oceanic evolution. Periodico di Mineralogia. 81, 35-59. 10.2451/2012PM0003