scholarly journals Dendrimers Terminated with Dichlorotriazine Groups Provide a Route to Compositional Diversity

2013 ◽  
Vol 15 (15) ◽  
pp. 3808-3811 ◽  
Author(s):  
Subrata Patra ◽  
Brittany Kozura ◽  
Adela Y.-T. Huang ◽  
Alan E. Enciso ◽  
Xiankai Sun ◽  
...  
Keyword(s):  
Compositional Diversity

Beyond compositional diversity: Examining the campus climate experiences of Asian American and Pacific Islander students.

2018 ◽  
Vol 11 (4) ◽  
pp. 484-501 ◽  
Author(s):  
Mike Hoa Nguyen ◽  
Jason Chan ◽  
Bach Mai Dolly Nguyen ◽  
Robert T. Teranishi
Keyword(s):  
Asian American ◽  
Campus Climate ◽  
Pacific Islander ◽  
Compositional Diversity

scholarly journals Compositional Diversity among Blackcurrant (Ribes nigrum) Cultivars Originating from European Countries

2019 ◽  
Vol 67 (19) ◽  
pp. 5621-5633 ◽  
Author(s):  
Ye Tian ◽  
Oskar Laaksonen ◽  
Heta Haikonen ◽  
Anita Vanag ◽  
Huma Ejaz ◽  
...  
Keyword(s):  
European Countries ◽  
Ribes Nigrum ◽  
Compositional Diversity

Abstract 260: Knockout of Apolipoprotein A-II Has Dramatic Effects on High-Density Lipoprotein Subspecies Distribution

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Scott M Gordon ◽  
Catherine A Reardon ◽  
Godfrey S Getz ◽  
W S Davidson
Keyword(s):  
Gel Filtration ◽  
Density Lipoprotein ◽  
High Density ◽  
Paraoxonase 1 ◽  
High Density Lipoproteins ◽  
Ionization Mass ◽  
Associated Proteins ◽  
Compositional Diversity ◽  
The Impact ◽  
Modest Effect

High density lipoproteins (HDL) are a highly heterogeneous population of particles composed of various lipids and proteins. They have been demonstrated to possess a diverse variety of functional properties which are thought to contribute to protection against cardiovascular disease (CVD). Proteomics studies have identified up to 75 different proteins which can associate with HDL. The basis for the compositional diversity of HDL is not known but a better understanding will yield important information about its broad functional diversity. To investigate the impact of common HDL apolipoproteins on the distribution of other apolipoproteins, we have begun to systematically fractionate plasma from various HDL apolipoprotein KO mice. Plasma from apoA-I, apoA-IV and apoA-II global KO mice was applied to gel filtration chromatography to distinguish HDL size populations. HDL particles sequestered by a phospholipid binding resin were proteomically analyzed by electrospray ionization mass spectrometry. By comparing elution volume shifts (i.e. particle size variations) for each HDL protein between WT controls and the KO models, we assessed the impact of the deleted protein on HDL size distributions. Ablation of apoA-I, while decreasing total HDL phospholipid by 70%, had a surprisingly small impact on the distribution of the majority of other HDL associated proteins - affecting only 9 of them. Genetic apoA-IV ablation had a similar modest effect shifting a distinct subset of 9 proteins. However, loss of apoA-II, in addition to causing a similar 70% reduction in overall HDL phospholipids, affected the size distribution of some 45 HDL proteins (including several complement proteins and paraoxonase-1). These data suggest that apoA-I, while associated with the majority of HDL phospholipid, may actually interact with relatively few of the lower abundance proteins known to be associated with HDL. ApoA-II on the other hand, may interact with many of these, perhaps acting as a docking site or adaptor molecule.

Compositional in situ analysis of dusty material stemming from Saturn’s main rings

2021 ◽  
Author(s):  
Simon Linti ◽  
Jon Hillier ◽  
Christian Fischer ◽  
Hsiang-Wen Hsu ◽  
Mario Trieloff ◽  
...  
Keyword(s):  
Interstellar Dust ◽  
Impact Ionization ◽  
Source Region ◽  
Relative Sensitivity ◽  
Cosmic Dust ◽  
Dust Grains ◽  
Element Ratios ◽  
Sensitivity Factors ◽  
Compositional Diversity

<p>During the final mission phase, the Cassini spacecraft travelled through the gap between Saturn and its innermost D ring. One goal of these highly inclined orbits was sampling the dust population, mostly made of impact ejecta from the main rings, in the vicinity of the planet. These in situ measurements were primarily carried out by the Cosmic Dust Analyzer (CDA) onboard the spacecraft, which provided time-of-flight mass spectra of individual ice and dust grains, mostly between about 10 and 50 nm in size. Here we present an update on the composition of the silicate dust fraction stemming from Saturn’s main rings, which makes up about 30 % of the observed particles with water ice being the remaining fraction [1].</p> <p>Elemental analysis of the silicate spectra was performed using an updated deconvolution method, based on a technique originally applied to the interpretation of CDA interstellar dust measurements [2]. Neighboring spectral peaks due to mineral-forming ions such as Mg<sup>+</sup>, Al<sup>+</sup> and Si<sup>+</sup> are often unresolvable, because of CDA’s relatively low (m/dm = 20–50) mass resolution [3]. Therefore, application of a deconvolution technique is required to disentangle the peak interferences and derive valuable compositional information. The robustness of the applied method has been tested and optimized through comparison with an independent automated fit algorithm. In order to calculate elemental abundances within the particles, the derived ion abundances were combined with experimentally-determined relative sensitivity factors (RSFs) [4]. To provide context to the measured element ratios, we compared them with a variety of space-relevant materials. We find an overlap with chondritic material for Mg/Si and Fe/Mg ratios. The observed range within the element ratios, however, indicates the contribution of a variety of minerals such as olivine, plagioclase or pyroxenes. Although our results agree with realistic mineral compositions, the calculated abundances of Al<sup>+</sup> ions are still relatively uncertain and can be seen as an upper limit.</p> <p>Additionally, we present the results of a dynamical model, which allow us to derive the likely source region within the main rings of individually detected silicate grains. We find the C and B rings to be the most likely sources of the vast majority of grains with the D ring being only a minor source. Currently an analysis of compositional diversity between the different ring segments is under way.</p> <p> </p> <p><strong>References</strong></p> <p>[1] H.-W. Hsu et al. (2018) In situ collection of dust grains falling from Saturn’s rings into its atmosphere. Science 362.</p> <p>[2] N. Altobelli et al. (2016) Flux and composition of interstellar dust at Saturn from Cassini’s Cosmic Dust Analyzer. Science 352, 312–318.</p> <p>[3] R. Srama et al. (2004) The Cassini Cosmic Dust Analyzer. Space Science Reviews 114, 465–518.</p> <p>[4] K. Fiege et al. (2014) Calibration of relative sensitivity factors for impact ionization detectors with high-velocity silicate microparticles. Icarus 241, 336–345.</p>

scholarly journals The Compositional Diversity of Low-Mass Exoplanets

2019 ◽  
Vol 47 (1) ◽  
pp. 141-171 ◽  
Author(s):  
Daniel Jontof-Hutter
Keyword(s):  
Bulk Composition ◽  
Diverse Range ◽  
Kepler Mission ◽  
Low Mass ◽  
Orbital Periods ◽  
Gaseous Atmospheres ◽  
The Masses ◽  
Compositional Diversity ◽  
Rocky Planets ◽  
Observational Techniques

Low-mass planets have an extraordinarily diverse range of bulk compositions, from primarily rocky worlds to those with deep gaseous atmospheres. As techniques for measuring the masses of exoplanets advance the field toward the regime of rocky planets, from ultrashort orbital periods to Venus-like distances, we identify the bounds on planet compositions, where sizes and incident fluxes inform bulk planet properties. In some cases, the precision of measurement of planet masses and sizes is approaching the theoretical uncertainties in planet models. An emerging picture explains aspects of the diversity of low-mass planets, although some problems remain: Do extreme low-density, low-mass planets challenge models of atmospheric mass loss? Are planet sizes strictly separated by bulk composition? Why do some stellar characterizations differ between observational techniques? With the Transiting Exoplanet Survey Satellite ( TESS) mission, low-mass exoplanets around the nearest stars will soon be discovered and characterized with unprecedented precision, permitting more detailed planetary modeling and atmospheric characterization of low-mass exoplanets than ever before. ▪ Following the Kepler mission, studies of exoplanetary compositions have entered the terrestrial regime. ▪ Low-mass planets have an extraordinary range of compositions, from Earth-like mixtures of rock and metal to mostly tenuous gas. ▪ The TESS mission will discover low-mass planets that can be studied in more detail than ever before.

scholarly journals Phytoplankton in extreme environments: importance and consequences of habitat permanency

Hydrobiologia ◽  
2020 ◽  
Vol 848 (1) ◽  
pp. 157-176 ◽  
Author(s):  
Judit Padisák ◽  
Luigi Naselli-Flores
Keyword(s):  
Extreme Environments ◽  
Single Species ◽  
Physiological Adaptation ◽  
Low Light ◽  
High Metal Content ◽  
Top Predators ◽  
Physiological Adaptations ◽  
Characteristic Species ◽  
Compositional Diversity ◽  
Harsh Conditions

AbstractThere is hardly any sunshine exposed surface on this Earth, be it water or terrain, which would not support some biota. Still, many habitats offer harsh conditions requiring specialized physiological adaptations to survive. These environments are referred to as extremes; often inhabited by extremophilic organisms. In this review, characteristic species and assemblage properties of phytoplankton inhabiting extreme environments (especially lakes and pools where planktic life is potentially possible and independently of their origin) in terms of alkalinity, acidity, DOC, salinity, temperature, light and mixing regime will be outlined. Lakes characterized by more than a single extreme are common (e.g. saline + alkaline; acidic + high DOC + high metal content + low light). At the edge of extremes (e.g. pH of 1; salinity over ~ 100–150 g l−1) single species with appropriate physiological adaptation are selected and the phytoplankton is often dominated by a single species (monodominant) setting compositional diversity to zero. Under less extreme conditions permanent equilibria may persist; in many cases over several years in contrast to „average” lakes where equilibria are rare and ephemeral. Food webs depending on „extreme phytoplankton” are often atypical for example because the microbial loop is of prior importance or because birds are top predators.

scholarly journals The extended lipid panel assay: a clinically-deployed high-throughput nuclear magnetic resonance method for the simultaneous measurement of lipids and Apolipoprotein B

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Erwin Garcia ◽  
Dennis W. Bennett ◽  
Margery A. Connelly ◽  
Elias J. Jeyarajah ◽  
Franklin C. Warf ◽  
...  
Keyword(s):  
Decision Making ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Throughput ◽  
Apolipoprotein B ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Lipid Panel ◽  
Compositional Diversity ◽  
Nuclear Magnetic

Abstract Background Standard lipid panel assays employing chemical/enzymatic methods measure total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C), from which are calculated estimates of low-density lipoprotein cholesterol (LDL-C). These lipid measures are used universally to guide management of atherosclerotic cardiovascular disease risk. Apolipoprotein B (apoB) is generally acknowledged to be superior to LDL-C for lipid-lowering therapeutic decision-making, but apoB immunoassays are performed relatively infrequently due to the added analytic cost. The aim of this study was to develop and validate the performance of a rapid, high-throughput, reagent-less assay producing an “Extended Lipid Panel” (ELP) that includes apoB, using the Vantera® nuclear magnetic resonance (NMR) analyzer platform already deployed clinically for lipoprotein particle and other testing. Methods Partial least squares regression models, using as input a defined region of proton NMR spectra of plasma or serum, were created to simultaneously quantify TC, TG, HDL-C, and apoB. Large training sets (n > ~ 1000) of patient sera analyzed independently for lipids and apoB by chemical methods were employed to ensure prediction models reflect the wide lipid compositional diversity of the population. The analytical performance of the NMR ELP assay was comprehensively evaluated. Results Excellent agreement was demonstrated between chemically-measured and ELP assay values of TC, TG, HDL-C and apoB with correlation coefficients ranging from 0.980 to 0.997. Within-run precision studies measured using low, medium, and high level serum pools gave coefficients of variation for the 4 analytes ranging from 1.0 to 3.8% for the low, 1.0 to 1.7% for the medium, and 0.9 to 1.3% for the high pools. Corresponding values for within-lab precision over 20 days were 1.4 to 3.6%, 1.2 to 2.3%, and 1.0 to 1.9%, respectively. Independent testing at three sites over 5 days produced highly consistent assay results. No major interference was observed from 38 endogenous or exogenous substances tested. Conclusions Extensive assay performance evaluations validate that the NMR ELP assay is efficient, robust, and substantially equivalent to standard chemistry assays for the clinical measurement of lipids and apoB. Routine reporting of apoB alongside standard lipid measures could facilitate more widespread utilization of apoB for clinical decision-making.

scholarly journals The main pulse of the Siberian Traps expanded in size and composition

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
L. E. Augland ◽  
V. V. Ryabov ◽  
V. A. Vernikovsky ◽  
S. Planke ◽  
A. G. Polozov ◽  
...  
Keyword(s):  
Volcanic Activity ◽  
Volcanic Rocks ◽  
West Siberia ◽  
Main Pulse ◽  
Environmental Consequences ◽  
Siberian Traps ◽  
Minimum Age ◽  
Area North ◽  
Permian Mass Extinction ◽  
Compositional Diversity

AbstractEmplacement of large volumes of (sub)volcanic rocks during the main pulse of the Siberian Traps occurred within <1 m.y., coinciding with the end-Permian mass extinction. Volcanics from outside the main Siberian Traps, e.g. Taimyr and West Siberia, have since long been correlated, but existing geochronological data cannot resolve at a precision better than ~5 m.y. whether (sub)volcanic activity in these areas actually occurred during the main pulse or later. We report the first high precision U-Pb zircon geochronology from two alkaline ultramafic-felsic layered intrusive complexes from Taimyr, showing synchronicity between these and the main Siberian Traps (sub)volcanic pulse, and the presence of a second Dinerian-Smithian pulse. This is the first documentation of felsic intrusive magmatism occurring during the main pulse, testifying to the Siberian Trap’s compositional diversity. Furthermore, the intrusions cut basal basalts of the Taimyr lava stratigraphy hence providing a minimum age of these basalts of 251.64 ± 0.11 Ma. Synchronicity of (sub)volcanic activity between Taimyr and the Siberian Traps imply that the total area of the Siberian Traps main pulse should include a ~300 000 km2 area north of Norilsk. The vast aerial extent of the (sub)volcanic activity during the Siberian Traps main pulse may explain the severe environmental consequences.

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