Formation of atoll garnets from the aureole of the Ardara pluton, Co. Donegal, Ireland

1974 ◽  
Vol 39 (308) ◽  
pp. 878-888 ◽  
Author(s):  
J. A. T. Smellie
Keyword(s):  
Temperature Increase ◽  
Marked Decrease ◽  
Thermal Metamorphism ◽  
The Core ◽  
Data Support ◽  
Microprobe Data ◽  
Extreme Edge ◽  
Textural Evidence

SummaryA detailed petrographic and microprobe study was carried out on atoll-shaped garnets from the aureole of the Ardara pluton, in which regionally metamorphosed rocks have been affected by thermal metamorphism. Textural evidence showed that the atoll garnets are formed by replacement mainly by biotite, some plagioclase, quartz, and opaques, and may proceed from the garnet interior towards the margins, or from the margins into the core. Core replacement occurs mainly in those garnets enclosed by quartz or quartz-rich matrix.Microprobe analyses are presented of garnets in different stages of atoll formation. Compositional profiles at the garnet margins show abnormal (reversed) zoning with increase in MnO and Fe2O32, marked decrease of CaO, and decrease of MgO towards the extreme edge. With decreasing width of the atoll rims, there is generally an increase in MnO and to a lesser extent Fe2O3, a decrease in CaO; MgO is variable. The microprobe data support the textural observations and a model for atoll formation involving prograde resorption (i.e. garnet replacement during temperature increase) is presented.

Feldspars from Adamant pluton, British Columbia

1969 ◽  
Vol 6 (5) ◽  
pp. 1199-1209 ◽  
Author(s):  
Peter E. Fox ◽  
John M. Moore Jr.
Keyword(s):  
British Columbia ◽  
Distribution Coefficient ◽  
Structural State ◽  
Regional Metamorphism ◽  
Approach To Equilibrium ◽  
The Core ◽  
Igneous Origin ◽  
Quartz Monzonite ◽  
Textural Evidence ◽  
Alkali Feldspars

Adamant pluton is a zoned body of igneous origin, with a core of pyroxene monzonite transitional outward to hornblende quartz monzonite and biotite-hornblende granodiorite. On chemical and textural evidence, the lithologic zoning resulted from reaction with introduced water and oxygen during regional metamorphism to upper amphibolite facies. Feldspars in the monzonite are orthoclase and andesine of intermediate structural state. During transformation of the pluton, systematic changes in the feldspars comprised: (1) ordering of alkali feldspars toward intermediate microcline, with increase of 2V, decrease of Na and Ca content, and appearance of grid twins; (2) ordering and increase in Na content of plagioclase. The most ordered feldspars, with highest Na distribution coefficient, are found in peripheral granodiorite and in pegmatite cutting the quartz monzonite. The feldspar data support the model proposed for the evolution of the pluton, indicating approach to equilibrium in the peripheral rocks at lower temperatures than that attendant to the formation of the core.

Mobility of Uranium, Thorium and Lanthanides Around the Bangombe Natural Reactor (Gabon)

1994 ◽  
Vol 353 ◽  
Author(s):  
R. Bros ◽  
F. Gauthier-Lafaye ◽  
P. Larque ◽  
J. Samuel ◽  
P. Stille
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Clay Minerals ◽  
Nuclear Reactor ◽  
Black Shales ◽  
Weathering Profile ◽  
The Core ◽  
Reducing Conditions ◽  
Isotopic Studies ◽  
Textural Evidence

AbstractNew mineralogical and isotopic studies were carried out on samples from the Bangombé natural nuclear reactor. This reactor is located at shallow depth in the weathering profile and has been subjected to severe supergene alteration. Textural evidence indicates partial dissolution of uraninite in the Bangombé ore related to precipitation of Fe-Ti oxi-hydroxides and clay minerals (kaolinite and metahalloysite). As a consequence of the alteration of the uraninite, uranium and f issiogenic rare earth elements were released in the clayey border of the reactor, whereas radiogenic 232Th remained confined in the close vicinity of the core. A retention effect is also evidenced, under reducing conditions, in the black shales located above the reactor.

scholarly journals Mapping of AF1 transactivation domains in duplicated rainbow trout glucocorticoid receptors

2010 ◽  
Vol 45 (6) ◽  
pp. 391-404 ◽  
Author(s):  
Armin Sturm ◽  
James E Bron ◽  
Darren M Green ◽  
Nic R Bury
Keyword(s):  
Amino Acids ◽  
Rainbow Trout ◽  
Glucocorticoid Receptors ◽  
Marked Decrease ◽  
Binding Activity ◽  
Wild Type ◽  
Sequence Alignments ◽  
The Core ◽  
Terminal Domain ◽  
Transactivation Domains

The glucocorticoid receptor (GR) is a ligand-dependent transcription factor mediating the genomic effects of glucocorticoids. Two activation functions (AFs) are present in the GR. While the N-terminal AF1 is ligand independent, the C-terminal AF2 overlaps with the ligand-binding domain and is ligand dependent. In this study, we have mapped AF1 in duplicated rainbow trout GRs, called rtGR1 and rtGR2, showing a limited homology (24.5%) in the N-terminal domain. Ablation of this domain from rtGR1 or rtGR2 resulted in a marked decrease (>97%) in maximal hormone-dependent transactivation, but did not affect dexamethasone-binding activity or expression levels. This suggested that, similar to the situation in the human GR (hGR), AF1 is the main AF in the trout GRs. Sequence alignments with hGR suggested a localisation of AF1 to residues 70–230 of rtGR1 and 1–119 of rtGR2. These assignments were generally confirmed in the transactivation experiments with rtGR1- and rtGR2-derived mutants showing partial deletions of their N-terminal domains. In dexamethsone-treated cells (10−7 M, 2 h), the subcellular distribution of rtGR1 and rtGR2 mutants lacking the entire N-terminal domain, as well that of an rtGR1 mutant lacking the most N-terminal 234 amino acids, was similar to that of the corresponding wild-type GRs, suggesting that the disruption of transactivation activity was not caused by impairment of nuclear access of the mutants. Bioinformatic analyses predicted the presence of potential helical segments in the core of AF1 of rtGR1 and rtGR2, and further revealed that AF1 in rtGR1, rtGR2, and hGR shares a motif composed of hydrophobic and acidic amino acids.

scholarly journals Mineral chemistry of tantalate species new in the Borborema Pegmatitic Province, Northeast Brazil

2005 ◽  
Vol 77 (1) ◽  
pp. 169-182 ◽  
Author(s):  
Hartmut Beurlen ◽  
Dwight R. Soares ◽  
Rainer Thomas ◽  
Lucila E. Prado-Borges ◽  
Cláudio de Castro
Keyword(s):  
Mineral Chemistry ◽  
Northeast Brazil ◽  
Small Areas ◽  
The Core ◽  
Reverse Trend ◽  
Geochemical Indicators ◽  
Microprobe Data ◽  
Normal Trend

Tantalate samples, supposedly of the columbite group, were collected in the Borborema Pegmatitic Province, aiming to test the Mn/(Mn+Fe) and Ta/(Ta+Nb) ratios as geochemical indicators of pegmatite fractionation. Surprisingly, preliminary microprobe data allowed recognizing some species, so far unknown in the Province, namely titanian ixiolite, fersmite, brannerite, strüverite, natrobistantite, plumbo- and stibiomicrolite, plumboand uranpyrochlore. The identification of these exotic tantalates with unusual composition, in addition to its distribution in several pegmatites, far from the classical Alto do Giz and Seridozinho pegmatites, indicate that the elevated degree of fractionation is not restricted to these two occurrences but may be reached in other pegmatite areas of the Province. It indicates also that this degree of fractionation may be very variable between pegmatites in small areas. The zoning patterns observed in the titanian ixiolite, with Ti and Nb enrichment at the borders at expense of Ta enriched in the core, are also quite unusual and reverse in comparison with the normal trend of progressive Ta and Mn enrichment in tantalates with the degree of fractionation. A similar "reverse" trend was observed in titanian wodginite of petalite/pollucite bearing pegmatites of the Separation Rapids Province in Ontario, Canada.

V.—The Petrology of Byne Hill, Ayrshire

1968 ◽  
Vol 68 (5) ◽  
pp. 105-122 ◽  
Author(s):  
T. W. Bloxam
Keyword(s):  
Fractional Crystallization ◽  
Quartz Diorite ◽  
Igneous Rocks ◽  
Rock Series ◽  
The Core ◽  
Lower Ordovician ◽  
Textural Evidence

SynopsisByne Hill, two miles south of Girvan, Ayrshire, is composed of Lower Ordovician igneous rocks which form partof the Girvan-Ballantrae igneous series. Byne Hill consists of serpentinized harzburgite, gabbro, diorite and trondhjemite which probably form a N.E.–S.W. elongated dome with trondhjemite occupying the core. There are transitional passages from gabbro into dioritic gabbro, diorite, quartz diorite and trondhjemite with no sharp contacts, and gabbroidal minerals and textures persist into the marginal hornblendic phases of the trondhjemite. The mineralogical changes are mainly progressive amphibolization and albitization of the gabbro accompanied by increases in SiO2 and Na2O. Geochemical culminations of FeO, MnO and P2O5 occur in the intermediate dioritic gabbro and diorites. Comparing the intermediate rocks with similar rock series from other areas suggests that mineralogical and chemical criteria do not always distinguish intermediate rocks of metasomatic origin from those produced by fractional crystallization. On Byne Hill the textural evidence suggests that the intermediate rocks are hybrids produced by reaction between crystalline gabbro and silicic sodium-rich solutions related to the trondhjemite, although there is evidence that the trondhjemite is itself metasomatic in origin. Serpentinization and rodingitization of the Byne Hill gabbro at contacts with serpentinite are described, and it is concluded that the gabbro was emplaced into the ultrabasic rocks prior to their serpentinization.

scholarly journals Phylogeny of Maleae (Rosaceae) Based on Multiple Chloroplast Regions: Implications to Genera Circumscription

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jiahui Sun ◽  
Shuo Shi ◽  
Jinlu Li ◽  
Jing Yu ◽  
Ling Wang ◽  
...  
Keyword(s):  
Molecular Phylogeny ◽  
Phylogenetic Relationships ◽  
Chloroplast Gene ◽  
Generic Level ◽  
Taxonomic Treatment ◽  
The Core ◽  
Data Support ◽  
Basal Clade ◽  
Gene Data

Maleae consists of economically and ecologically important plants. However, there are considerable disputes on generic circumscription due to the lack of a reliable phylogeny at generic level. In this study, molecular phylogeny of 35 generally accepted genera in Maleae is established using 15 chloroplast regions. Gillenia is the most basal clade of Maleae, followed by Kageneckia + Lindleya, Vauquelinia, and a typical radiation clade, the core Maleae, suggesting that the proposal of four subtribes is reasonable. In the core Maleae including 31 genera, chloroplast gene data support that the four Malus-related genera should better be merged into one genus and the six Sorbus-related genera would be classified into two genera, whereas all Photinia-related genera should be accepted as distinct genera. Although the phylogenetic relationships among the genera in Maleae are much clearer than before, it is still premature to make a formal taxonomic treatment for these genera.

scholarly journals Structure of the C1r–C1s interaction of the C1 complex of complement activation

2018 ◽  
Vol 115 (4) ◽  
pp. 768-773 ◽  
Author(s):  
Jamal O. M. Almitairi ◽  
Umakhanth Venkatraman Girija ◽  
Christopher M. Furze ◽  
Xanthe Simpson-Gray ◽  
Farah Badakshi ◽  
...  
Keyword(s):  
Complex Formation ◽  
Complement Activation ◽  
Recent Model ◽  
Classical Pathway ◽  
Apoptotic Cells ◽  
Multiprotein Complex ◽  
The Core ◽  
Catalytic Domains ◽  
Data Support ◽  
Terminal Domains

The multiprotein complex C1 initiates the classical pathway of complement activation on binding to antibody–antigen complexes, pathogen surfaces, apoptotic cells, and polyanionic structures. It is formed from the recognition subcomponent C1q and a tetramer of proteases C1r2C1s2 as a Ca2+-dependent complex. Here we have determined the structure of a complex between the CUB1-EGF-CUB2 fragments of C1r and C1s to reveal the C1r–C1s interaction that forms the core of C1. Both fragments are L-shaped and interlock to form a compact antiparallel heterodimer with a Ca2+ from each subcomponent at the interface. Contacts, involving all three domains of each protease, are more extensive than those of C1r or C1s homodimers, explaining why heterocomplexes form preferentially. The available structural and biophysical data support a model of C1r2C1s2 in which two C1r-C1s dimers are linked via the catalytic domains of C1r. They are incompatible with a recent model in which the N-terminal domains of C1r and C1s form a fixed tetramer. On binding to C1q, the proteases become more compact, with the C1r-C1s dimers at the center and the six collagenous stems of C1q arranged around the perimeter. Activation is likely driven by separation of the C1r-C1s dimer pairs when C1q binds to a surface. Considerable flexibility in C1s likely facilitates C1 complex formation, activation of C1s by C1r, and binding and activation of downstream substrates C4 and C4b-bound C2 to initiate the reaction cascade.

scholarly journals Phosphorylation of the selective autophagy receptor TAX1BP1 by canonical and noncanonical IκB kinases promotes its lysosomal localization and clearance of MAVS aggregates

2021 ◽  
Author(s):  
Young Bong Choi ◽  
Jiawen Zhang ◽  
Mai Tram Vo ◽  
Jesse White ◽  
Chaoxia He ◽  
...  
Keyword(s):  
Virus Infection ◽  
Rna Virus ◽  
Critical Role ◽  
Selective Autophagy ◽  
The Core ◽  
Data Support ◽  
Iκb Kinase

TAX1BP1 is a selective autophagy receptor which inhibits NF-κB and RIG-I-like receptor (RLR) signaling to prevent excessive inflammation and maintain homeostasis. Selective autophagy receptors such as p62/SQSTM1 and OPTN are phosphorylated by the noncanonical IκB kinase TBK1 to stimulate their selective autophagy function. However, it is unknown if TAX1BP1 is regulated by TBK1 or other kinases under basal conditions or during RNA virus infection. Here, we found that the noncanonical IκB kinases TBK1 and IKKi phosphorylate TAX1BP1 to regulate its basal turnover, whereas the canonical IκB kinase IKKα and the core autophagy factor ATG9 play essential roles in RNA virus-mediated TAX1BP1 autophagosomal degradation. TAX1BP1 phosphorylation by canonical and noncanonical IκB kinases promotes its localization to lysosomes resulting in its degradation. Furthermore, TAX1BP1 plays a critical role in the clearance of MAVS aggregates, and phosphorylation of TAX1BP1 augments its MAVS aggrephagy function. Together, our data support a model whereby IκB kinases license TAX1BP1 selective autophagy function to inhibit MAVS and RLR signaling.

What face familiarity feelings say about the lateralization of specific entities within the core system

2019 ◽  
Vol 42 ◽  
Author(s):  
Guido Gainotti
Keyword(s):  
Temporal Lobe ◽  
Memory System ◽  
Core System ◽  
The Core ◽  
Memory Traces ◽  
Specific Memory ◽  
Target Article ◽  
Temporal Structures ◽  
The Right

Abstract The target article carefully describes the memory system, centered on the temporal lobe that builds specific memory traces. It does not, however, mention the laterality effects that exist within this system. This commentary briefly surveys evidence showing that clear asymmetries exist within the temporal lobe structures subserving the core system and that the right temporal structures mainly underpin face familiarity feelings.

A scanning electron microscopic study on dissolving process of cholesterol gallstones by chenodeoxycholic acid (CDCA)

1978 ◽  
Vol 36 (2) ◽  
pp. 522-523
Author(s):  
T. Kanetaka ◽  
M. Cho ◽  
S. Kawamura ◽  
T. Sado ◽  
K. Hara
Keyword(s):  
Electron Microscope ◽  
Chenodeoxycholic Acid ◽  
Outer Surface ◽  
Electron Microscopic ◽  
Cholesterol Gallstones ◽  
The Core ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Acceleration Voltage ◽  
Scanning Electron

The authors have investigated the dissolution process of human cholesterol gallstones using a scanning electron microscope(SEM). This study was carried out by comparing control gallstones incubated in beagle bile with gallstones obtained from patients who were treated with chenodeoxycholic acid(CDCA).The cholesterol gallstones for this study were obtained from 14 patients. Three control patients were treated without CDCA and eleven patients were treated with CDCA 300-600 mg/day for periods ranging from four to twenty five months. It was confirmed through chemical analysis that these gallstones contained more than 80% cholesterol in both the outer surface and the core.The specimen were obtained from the outer surface and the core of the gallstones. Each specimen was attached to alminum sheet and coated with carbon to 100Å thickness. The SEM observation was made by Hitachi S-550 with 20 kV acceleration voltage and with 60-20, 000X magnification.

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