Differentiating induced versus spontaneous subduction initiation using thermomechanical models and metamorphic soles

AbstractDespite the critical role of subduction in plate tectonics, the dynamics of its initiation remains unclear. High-temperature low-pressure metamorphic soles are vestiges of subduction initiation, providing records of the pressure and temperature conditions along the subducting slab surface during subduction initiation that can possibly differentiate the two end-member subduction initiation modes: spontaneous and induced. Here, using numerical models, we show that the slab surface temperature reaches 800–900 °C at ~1 GPa over a wide range of parameter values for spontaneous subduction initiation whereas for induced subduction initiation, such conditions can be reached only if the age of the overriding plate is <5 Ma. These modeling results indicate that spontaneous subduction initiation would be more favorable for creating high-temperature conditions. However, the synthesis of our modeling results and geological observations indicate that the majority of the metamorphic soles likely formed during induced subduction initiation that involved a young overriding plate.

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Development of cancer metabolism as a therapeutic target: new pathways, patient studies, stratification and combination therapy

British Journal of Cancer ◽

10.1038/s41416-019-0666-4 ◽

2019 ◽

Vol 122 (1) ◽

pp. 1-3 ◽

Cited By ~ 4

Author(s):

Adrian L. Harris

Keyword(s):

Metabolic Pathways ◽

Trial Design ◽

Cancer Metabolism ◽

Aerobic Glycolysis ◽

Critical Role ◽

Therapeutic Approaches ◽

Preclinical Models ◽

Wide Range ◽

Patient Studies

AbstractCancer metabolism has undergone a resurgence in the last decade, 70 years after Warburg described aerobic glycolysis as a feature of cancer cells. A wide range of techniques have elucidated the complexity and heterogeneity in preclinical models and clinical studies. What emerges are the large differences between tissues, tumour types and intratumour heterogeneity. However, synergies with inhibition of metabolic pathways have been found for many drugs and therapeutic approaches, and a critical role of window studies and translational trial design is key to success.

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Wildlife management and the debate on the ethics of animal use. II. A challenge for the animal protection movement.

Pacific Conservation Biology ◽

10.1071/pc120081 ◽

2012 ◽

Vol 18 (2) ◽

pp. 81 ◽

Cited By ~ 9

Author(s):

Daniel Lunney

Keyword(s):

Wildlife Management ◽

Critical Role ◽

Animal Liberation ◽

Ethical Imperative ◽

Animal Protection ◽

Wide Range ◽

Animal Use

How people coexist and interact with animals has become an intensely debated issue in recent times, particularly with the rise of the animal protection movement following the publication of Peter Singer’s book Animal Liberation in 1975. This paper discusses some shortcomings of the philosophical positions taken in this complex debate. Singer has helped put animals on a new footing as a group that cannot morally be ignored, but his focus is mainly on individual, familiar animals that are used or abused by humans. The argument of this paper is that the ethics of managing wildlife hinges on a broader view of animals, and their contexts, than is apparent from Singer’s text. Wildlife managers aim to conserve populations of a wide range of species, and their habitats, but some mechanisms for achieving these aims, such as research and the control of invasive animals, are frequently opposed by elements of the animal protection movement. We need to adapt our attitude to animals, particularly wildlife, away from the traditional legacy of a few familiar species to embrace an ethic that is more ecological and relevant to Australian contexts. The case argued here has been to see the critical role of context — geographical, ecological, historical, relational — as a basis for a degree of reconciliation between conservation-oriented wildlife managers and the rising interest in the ethics of animal use. There is much to be gained for zoologists, wildlife managers and conservation biologists by framing key elements of their case in ethical arguments. Conversely, the challenge for those in the animal protection movement is to expand their philosophical ideas to include the ethical imperative of the conservation of populations of wildlife.

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The role of Edge-Driven Convection in the generation of volcanism I: a 2D systematic study

10.5194/se-2020-120 ◽

2020 ◽

Author(s):

Antonio Manjón-Cabeza Córdoba ◽

Maxim Ballmer

Keyword(s):

Numerical Models ◽

High Volume ◽

Oceanic Lithosphere ◽

Companion Paper ◽

Small Scale ◽

Continental Lithosphere ◽

Transient Phenomenon ◽

Mantle Viscosity ◽

Wide Range

Abstract. The origin of intraplate volcanism is not explained by the plate tectonic theory, and several models have been put forward for explanation. One of these models involves Edge-Driven Convection (EDC), in which cold and thick continental lithosphere is juxtaposed to warm and thin oceanic lithosphere to trigger convective instability. To test whether EDC can produce long-lived high-volume magmatism, we run numerical models of EDC for a wide range of mantle properties and edge (i.e., the oceanic-continental transition) geometries. We find that the most important parameters that govern EDC are the rheological paramaters mantle viscosity η0 and activation energy Ea. However, even the maximum melting volumes found in our models are insufficient to account for island-building volcanism on old seafloor, such as at the Canary Islands and Cape Verde. Also, beneath old seafloor, localized EDC-related melting commonly transitions into widespread melting due to small-scale sublithospheric convection, inconsistent with the distribution of volcanism at these volcanic chains. In turn, EDC is a good candidate to sustain the formation of small seamounts on young seafloor, as it is a highly transient phenomenon that occurs in all our models soon after initiation. In a companion paper, we investigate the implications of interaction of EDC with mantle-plume activity.

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The role of edge-driven convection in the generation of volcanism – Part 1: A 2D systematic study

Solid Earth ◽

10.5194/se-12-613-2021 ◽

2021 ◽

Vol 12 (3) ◽

pp. 613-632

Author(s):

Antonio Manjón-Cabeza Córdoba ◽

Maxim D. Ballmer

Keyword(s):

Numerical Models ◽

High Volume ◽

Oceanic Lithosphere ◽

Companion Paper ◽

Rheological Parameters ◽

Small Scale ◽

Transient Phenomenon ◽

Mantle Viscosity ◽

Wide Range

Abstract. The origin of intraplate volcanism is not explained by plate tectonic theory, and several models have been put forward for explanation. One of these models involves edge-driven convection (EDC), in which cold and thick continental lithosphere is juxtaposed with warm and thin oceanic lithosphere to trigger convective instability. To test whether EDC can produce long-lived high-volume magmatism, we run numerical models of EDC for a wide range of mantle properties and edge (i.e., the oceanic–continental transition) geometries. We find that the most important parameters that govern EDC are the rheological parameters mantle viscosity η0 and activation energy Ea. However, even the maximum melting volumes predicted by our most extreme cases are insufficient to account for island-building volcanism on old seafloor, such as at the Canary Islands and Cabo Verde. Also, beneath old seafloor, localized EDC-related melting commonly transitions into widespread melting due to small-scale sublithospheric convection, inconsistent with the distribution of volcanism at these volcano chains. In turn, EDC is a good candidate to sustain the formation of small seamounts on young seafloor, as it is a highly transient phenomenon that occurs in all our models soon after initiation. In a companion paper, we investigate the implications of interaction of EDC with mantle plume activity (Manjón-Cabeza Córdoba and Ballmer, 2021).

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Molecular-scale investigation of the oxidation behavior of chromia-forming alloys in high-temperature CO2

npj Materials Degradation ◽

10.1038/s41529-021-00194-1 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Richard P. Oleksak ◽

Rafik Addou ◽

Bharat Gwalani ◽

John P. Baltrus ◽

Tao Liu ◽

...

Keyword(s):

High Temperature ◽

Power Systems ◽

High Purity ◽

Photoelectron Spectroscopy ◽

Ambient Pressure ◽

Critical Role ◽

Atomic Scale ◽

Atomic Diffusion ◽

Carbon Transport

AbstractCurrent and future power systems require chromia-forming alloys compatible with high-temperature CO2. Important questions concerning the mechanisms of oxidation and carburization remain unanswered. Herein we shed light onto these processes by studying the very initial stages of oxidation of Fe22Cr and Fe22Ni22Cr model alloys. Ambient-pressure X-ray photoelectron spectroscopy enabled in situ analysis of the oxidizing surface under 1 mbar of flowing CO2 at temperatures up to 530 °C, while postexposure analyses revealed the structure and composition of the oxidized surface at the near-atomic scale. We found that gas purity played a critical role in the kinetics of the reaction, where high purity CO2 promoted the deposition of carbon and the selective oxidation of Cr. In contrast, no carbon deposition occurred in low purity CO2 and Fe oxidation ensued, thus highlighting the critical role of impurities in defining the early oxidation pathway of the alloy. The Cr-rich oxide formed on Fe22Cr in high purity CO2 was both thicker and more permeable to carbon compared to that formed on Fe22Ni22Cr, where carbon transport appeared to occur by atomic diffusion through the oxide. Alternatively, the Fe-rich oxide formed in low purity CO2 suggested carbon transport by molecular CO2.

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LSD1, a double-edged sword, confers dynamic chromatin regulation but commonly promotes aberrant cell growth

F1000Research ◽

10.12688/f1000research.12169.1 ◽

2017 ◽

Vol 6 ◽

pp. 2016 ◽

Cited By ~ 13

Author(s):

Meghan M Kozub ◽

Ryan M Carr ◽

Gwen L Lomberk ◽

Martin E Fernandez-Zapico

Keyword(s):

Gene Expression ◽

Chromatin Remodeling ◽

Cellular Differentiation ◽

Critical Role ◽

Histone Demethylase ◽

Epigenetic Changes ◽

Lysine Specific Demethylase ◽

Wide Range ◽

Histone Modifying Enzymes

Histone-modifying enzymes play a critical role in chromatin remodeling and are essential for influencing several genome processes such as gene expression and DNA repair, replication, and recombination. The discovery of lysine-specific demethylase 1 (LSD1), the first identified histone demethylase, dramatically revolutionized research in the field of epigenetics. LSD1 plays a pivotal role in a wide range of biological operations, including development, cellular differentiation, embryonic pluripotency, and disease (for example, cancer). This mini-review focuses on the role of LSD1 in chromatin regulatory complexes, its involvement in epigenetic changes throughout development, and its importance in physiological and pathological processes.

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What Neuroscientific Studies Tell Us about Inhibition of Return

Vision ◽

10.3390/vision3040058 ◽

2019 ◽

Vol 3 (4) ◽

pp. 58 ◽

Cited By ~ 2

Author(s):

Jason Satel ◽

Nicholas R. Wilson ◽

Raymond M. Klein

Keyword(s):

Inhibition Of Return ◽

Brain Activity ◽

Critical Role ◽

Direct Methods ◽

Brain Structures ◽

Developmental Studies ◽

Unit Recording ◽

Wide Range ◽

Lesion Studies

An inhibitory aftermath of orienting, inhibition of return (IOR), has intrigued scholars since its discovery about 40 years ago. Since then, the phenomenon has been subjected to a wide range of neuroscientific methods and the results of these are reviewed in this paper. These include direct manipulations of brain structures (which occur naturally in brain damage and disease or experimentally as in TMS and lesion studies) and measurements of brain activity (in humans using EEG and fMRI and in animals using single unit recording). A variety of less direct methods (e.g., computational modeling, developmental studies, etc.) have also been used. The findings from this wide range of methods support the critical role of subcortical and cortical oculomotor pathways in the generation and nature of IOR.

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