Textural, geochemical, and isotopic data from silicified rocks and associated chemical sedimentary rocks in the ~ 2.7 Ga Abitibi greenstone belt, Canada: Insight into the role of silicification

2020 ◽  
Vol 351 ◽  
pp. 105946
Author(s):  
Latisha A. Brengman ◽  
Christopher M. Fedo ◽  
Martin J. Whitehouse ◽  
Iffat Jabeen ◽  
Neil R. Banerjee
1987 ◽  
Vol 24 (9) ◽  
pp. 1916-1919 ◽  
Author(s):  
J. Kalliokoski

A belt of Archean quartzose metasedimentary gneisses with minor mafic volcanic rocks (the Pontiac Group) lies south of the Blake River and older Archean mafic volcanic rocks of the Abitibi Greenstone Belt, and is separated from them by the Larder Lake – Cadillac Break. To the west of the Pontiac Group, on strike, is the Archean Larder Lake Group of turbidite conglomerate, argillite, limestone, and iron formation with abundant mafic flows and intrusions. These strata also lie south of the Larder Lake – Cadillac Break and south of the Blake River and older Archean mafic volcanic rocks. The western contact between the Pontiac and Larder Lake groups is covered by a narrow north–south strip of Proterozoic Cobalt sedimentary rocks. On the basis of gravity work that compares the Bouguer gravity anomaly gradient across the Cadillac Break with that across the west margin of the Pontiac Group, it is proposed that the Larder Lake and Pontiac groups are separated by a north–south fault and that the Pontiac Group represents a lithologically distinct uplifted block. The Pontiac block may be an Archean terrane.


1992 ◽  
Vol 67 (01) ◽  
pp. 111-116 ◽  
Author(s):  
Marcel Levi ◽  
Jan Paul de Boer ◽  
Dorina Roem ◽  
Jan Wouter ten Cate ◽  
C Erik Hack

SummaryInfusion of desamino-d-arginine vasopressin (DDAVP) results in an increase in plasma plasminogen activator activity. Whether this increase results in the generation of plasmin in vivo has never been established.A novel sensitive radioimmunoassay (RIA) for the measurement of the complex between plasmin and its main inhibitor α2 antiplasmin (PAP complex) was developed using monoclonal antibodies preferentially reacting with complexed and inactivated α2-antiplasmin and monoclonal antibodies against plasmin. The assay was validated in healthy volunteers and in patients with an activated fibrinolytic system.Infusion of DDAVP in a randomized placebo controlled crossover study resulted in all volunteers in a 6.6-fold increase in PAP complex, which was maximal between 15 and 30 min after the start of the infusion. Hereafter, plasma levels of PAP complex decreased with an apparent half-life of disappearance of about 120 min. Infusion of DDAVP did not induce generation of thrombin, as measured by plasma levels of prothrombin fragment F1+2 and thrombin-antithrombin III (TAT) complex.We conclude that the increase in plasminogen activator activity upon the infusion of DDAVP results in the in vivo generation of plasmin, in the absence of coagulation activation. Studying the DDAVP induced increase in PAP complex of patients with thromboembolic disease and a defective plasminogen activator response upon DDAVP may provide more insight into the role of the fibrinolytic system in the pathogenesis of thrombosis.


2019 ◽  
Vol 58 (2) ◽  
pp. 249-259
Author(s):  
Joseph Acquisto

This essay examines a polemic between two Baudelaire critics of the 1930s, Jean Cassou and Benjamin Fondane, which centered on the relationship of poetry to progressive politics and metaphysics. I argue that a return to Baudelaire's poetry can yield insight into what seems like an impasse in Cassou and Fondane. Baudelaire provides the possibility of realigning metaphysics and politics so that poetry has the potential to become the space in which we can begin to think the two of them together, as opposed to seeing them in unresolvable tension. Or rather, the tension that Baudelaire animates between the two allows us a new way of thinking about the role of esthetics in moments of political crisis. We can in some ways see Baudelaire as responding, avant la lettre, to two of his early twentieth-century readers who correctly perceived his work as the space that breathes a new urgency into the questions of how modern poetry relates to the world from which it springs and in which it intervenes.


Letonica ◽  
2020 ◽  
Author(s):  
Māra Grudule

The article gives insight into a specific component of the work of Baltic enlightener Gotthard Friedrich Stender (1714–1796) that has heretofore been almost unexplored — the transfer of German musical traditions to the Latvian cultural space. Even though there are no sources that claim that Stender was a composer himself, and none of his books contain musical notation, the texts that had been translated by Stender and published in the collections “Jaunas ziņģes” (New popular songs, 1774) and “Ziņģu lustes” (The Joy of singing, 1785, 1789) were meant for singing and, possibly, also for solo-singing with the accompaniment of some musical instrument. This is suggested, first, by how the form of the translation corresponds to the original’s form; second, by the directions, oftentimes attached to the text, that indicate the melody; and third, by the genres of the German originals cantata and song. Stender translated several compositions into Latvian including the text of the religious cantata “Der Tod Jesu” (The Death of Jesus, 1755) by composer Karl Heinrich Graun (1754–1759); songs by various composers that were widely known in German society; as well as a collection of songs by the composer Johann Gottlieb Naumann (1741–1801) that, in its original form, was published together with notation and was intended for solo-singing (female vocals) with the accompaniment of a piano. This article reveals the context of German musical life in the second half of the 18th century and explains the role of music as an instrument of education in Baltic-German and Latvian societies.


Author(s):  
James Marlatt

ABSTRACT Many people may not be aware of the extent of Kurt Kyser's collaboration with mineral exploration companies through applied research and the development of innovative exploration technologies, starting at the University of Saskatchewan and continuing through the Queen's Facility for Isotope Research. Applied collaborative, geoscientific, industry-academia research and development programs can yield technological innovations that can improve the mineral exploration discovery rates of economic mineral deposits. Alliances between exploration geoscientists and geoscientific researchers can benefit both parties, contributing to the pure and applied geoscientific knowledge base and the development of innovations in mineral exploration technology. Through a collaboration that spanned over three decades, we gained insight into the potential for economic uranium deposits around the world in Canada, Australia, USA, Finland, Russia, Gabon, Namibia, Botswana, South Africa, and Guyana. Kurt, his research team, postdoctoral fellows, and students developed technological innovations related to holistic basin analysis for economic mineral potential, isotopes in mineral exploration, and biogeochemical exploration, among others. In this paper, the business of mineral exploration is briefly described, and some examples of industry-academic collaboration innovations brought forward through Kurt's research are identified. Kurt was a masterful and capable knowledge broker, which is a key criterion for bringing new technologies to application—a grand, curious, credible, patient, and attentive communicator—whether talking about science, business, or life and with first ministers, senior technocrats, peers, board members, first nation peoples, exploration geologists, investors, students, citizens, or friends.


2021 ◽  
pp. 003329412097663
Author(s):  
Cristina Trentini ◽  
Renata Tambelli ◽  
Silvia Maiorani ◽  
Marco Lauriola

Empathy refers to the capacity to experience emotions similar to those observed or imagined in another person, with the full knowledge that the other person is the source of these emotions. Awareness of one's own emotional states is a prerequisite for self-other differentiation to develop. This study investigated gender differences in empathy during adolescence and tested whether emotional self-awareness explained these differences. Two-hundred-eleven adolescents (108 girls and 103 boys) between 14 and 19 years completed the Interpersonal Reactivity Index (IRI) and the Toronto Alexithymia Scale (TAS-20) to assess empathy and emotional self-awareness, respectively. Overall, girls obtained higher scores than boys on IRI subscales like emotional concern, personal distress, and fantasy. Regarding emotional self-awareness, we found gender differences in TAS-20 scores, with girls reporting greater difficulty identifying feelings and less externally oriented thinking than boys. Difficulty identifying feelings explained the greatest personal distress experienced by girls. Lower externally oriented thinking accounted for girls’ greater emotional concern and fantasy. These findings offer an insight into the role of emotional self-awareness–which is essential for self-other differentiation–as an account for gender differences in empathic abilities during adolescence. In girls, difficulty identifying feelings can impair the ability to differentiate between ones’ and others’ emotions, leading them to experience self-focused and aversive responses when confronted with others’ suffering. Conversely, in boys, externally oriented thinking can mitigate personal distress when faced with others’ discomfort.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 962
Author(s):  
Maciej Jerzy Bernacki ◽  
Anna Rusaczonek ◽  
Weronika Czarnocka ◽  
Stanisław Karpiński

Salicylic acid (SA) is well known hormonal molecule involved in cell death regulation. In response to a broad range of environmental factors (e.g., high light, UV, pathogens attack), plants accumulate SA, which participates in cell death induction and spread in some foliar cells. LESION SIMULATING DISEASE 1 (LSD1) is one of the best-known cell death regulators in Arabidopsis thaliana. The lsd1 mutant, lacking functional LSD1 protein, accumulates SA and is conditionally susceptible to many biotic and abiotic stresses. In order to get more insight into the role of LSD1-dependent regulation of SA accumulation during cell death, we crossed the lsd1 with the sid2 mutant, caring mutation in ISOCHORISMATE SYNTHASE 1(ICS1) gene and having deregulated SA synthesis, and with plants expressing the bacterial nahG gene and thus decomposing SA to catechol. In response to UV A+B irradiation, the lsd1 mutant exhibited clear cell death phenotype, which was reversed in lsd1/sid2 and lsd1/NahG plants. The expression of PR-genes and the H2O2 content in UV-treated lsd1 were significantly higher when compared with the wild type. In contrast, lsd1/sid2 and lsd1/NahG plants demonstrated comparability with the wild-type level of PR-genes expression and H2O2. Our results demonstrate that SA accumulation is crucial for triggering cell death in lsd1, while the reduction of excessive SA accumulation may lead to a greater tolerance toward abiotic stress.


Organics ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 38-49
Author(s):  
Lakhdar Benhamed ◽  
Sidi Mohamed Mekelleche ◽  
Wafaa Benchouk

Experimentally, a reversal of chemoselectivity has been observed in catalyzed Diels–Alder reactions of α,β-unsaturated aldehydes (e.g., (2E)-but-2-enal) and ketones (e.g., 2-hexen-4-one) with cyclopentadiene. Indeed, using the triflimidic Brønsted acid Tf2NH as catalyst, the reaction gave a Diels–Alder adduct derived from α,β-unsaturated ketone as a major product. On the other hand, the use of tris(pentafluorophenyl)borane B(C6F5)3 bulky Lewis acid as catalyst gave mainly the cycloadduct of α,β-unsaturated aldehyde as a major product. Our aim in the present work is to put in evidence the role of the catalyst in the reversal of the chemoselectivity of the catalyzed Diels–Alder reactions of (2E)-but-2-enal and 2-Hexen-4-one with cyclopentadiene. The calculations were performed at the ωB97XD/6-311G(d,p) level of theory and the solvent effects of dichloromethane were taken into account using the PCM solvation model. The obtained results are in good agreement with experimental outcomes.


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