Holocene-Neogene volcanism in northeastern Australia: chronology and eruption history

Quaternary and late Neogene volcanism is widespread in northeastern Australia, producing at least 397 eruptions covering more than 20,000 km2, including at least 20 flows over 50 km long. Despite this abundance of young volcanism, before this study numerous eruptions had tentative ages or were undated, and the area requires a comprehensive evaluation of eruption patterns through time. To help address these issues we applied multi-collector ARGUS-V 40Ar/39Ar geochronology to determine the age of four of the younger extensive flows: Undara (160 km long, 189 ± 4/4 ka; 2σ, with full analytical/external uncertainties), Murronga (40 km long, 153 ± 5/5 ka), Toomba (120 km long, 21 ± 3/3 ka), and Kinrara (55 km long, 7 ± 2/2 ka). Verbal traditions of the Gugu Badhun Aboriginal people contain features that may potentially describe the eruption of Kinrara. If the traditions do record this eruption, they would have been passed down for 230 ± 70 generations – a period of time exceeding the earliest written historical records. To further examine north Queensland volcanism through time we compiled a database of 337 ages, including 179 previously unpublished K-Ar and radiocarbon results. The compiled ages demonstrate that volcanic activity has occurred without major time breaks since at least 9 Ma. The greatest frequency of eruptions occurred in the last 2 Ma, with an average recurrence interval of <10–22 ka between eruptions. Activity was at times likely more frequent than these calculations indicate, as the geochronologic dataset is incomplete, with undated eruptions, and intraplate volcanism is often episodic. The duration, frequency, and youthfulness of activity indicate that north Queensland volcanism should be considered as potentially still active, and there are now two confirmed areas of Holocene volcanism in eastern Australia – one at each end of the continent. More broadly, our data provides another example of 40Ar/39Ar geochronology applied to Holocene and latest Pleistocene mafic eruptions, further demonstrating that this method has the ability to examine eruptions and hazards at the youngest volcanoes on Earth

Using single-cell technologies to map the human immune system - implications for nephrology.

Advances in single-cell technologies are transforming our understanding of cellular identity. For instance, the application of single-cell RNA sequencing and mass cytometry technologies to the study of immune cell populations in blood, secondary lymphoid organs and the renal tract is helping researchers to map the complex immune landscape within the kidney, define cell ontogeny and understand the relationship of kidney-resident immune cells with their circulating counterparts. These studies also provide insights into the interactions of immune cell populations with neighbouring epithelial and endothelial cells in health, and across a range of kidney diseases and cancer. These data have translational potential and will aid the identification of drug targets and enable better prediction of off-target effects. The application of single-cell technologies to clinical renal biopsy samples, or even cells within urine, will improve diagnostic accuracy and assist with personalized prognostication for patients with various kidney diseases. A comparison of immune cell types in peripheral blood and secondary lymphoid organs in healthy individuals and in patients with systemic autoimmune diseases that affect the kidney will also help to unravel the mechanisms that underpin the breakdown in self-tolerance and propagation of autoimmune responses. Together, these immune cell atlases have the potential to transform nephrology

Structural transitions, octahedral rotations, and electronic properties of A3A_3Ni2_2O7_7 rare-earth nickelates under high pressure

Motivated by the recent observation of superconductivity with $T_c \sim 80$ K in pressurized La3Ni2O7 [Nature 621, 493 (2023)], we explore the structural and electronic properties in A3Ni2O7 bilayer nickelates (A=La-Lu, Y, Sc) as a function of hydrostatic pressure (0-150 GPa) from first principles including a Coulomb repulsion term. At $\sim 20$ GPa, we observe an orthorhombic-to-tetragonal transition in La$_3$Ni$_2$O$_7$ at variance with recent x-ray diffraction data, which points to so-far unresolved complexities at the onset of superconductivity, e.g., charge doping by variations in the oxygen stoichiometry. We compile a structural phase diagram with particular emphasis on the $b/a$ ratio, octahedral anisotropy, and octahedral rotations. Intriguingly, chemical and external pressure emerge as two distinct and counteracting control parameters. We find unexpected correlations between $T_c$ and the in-plane Ni-O-Ni bond angles for La$_3$Ni$_2$O$_7$. Moreover, two novel structural phases with significant $c^+$ octahedral rotations and in-plane bond disproportionations are uncovered for A=Nd-Lu, Y, Sc that exhibit a surprising pressure-driven electronic reconstruction in the Ni $e_g$ manifold. By disentangling the involvement of basal versus apical oxygen states at the Fermi surface, we identify Tb$_3$Ni$_2$O$_7$ as an interesting candidate for superconductivity at ambient pressure. These results suggest a profound tunability of the structural and electronic phases in this novel materials class and are key for a fundamental understanding of the superconductivity mechanism.Comment: 12 pages, 5 figure

Privilege and Marginality: How Group Identification and Personality Predict Rightâ and Leftâ Wing Political Activism

In two studies, we examine how different processes might underlie the political mobilization of individuals with marginalized versus privileged identities for leftâ wing activism (LWA) versus rightâ wing activism (RWA). In the first study, with a sample of 244 midlife women, we tested the hypotheses that endorsement of system justification beliefs and social identities were direct predictors of political activism, and that system justification beliefs moderated the mobilization of social identities for activism on both the left and the right. We found that system justification predicted RWA only among those who felt close to privileged groups; the parallel reverse effect did not hold for LWA, though rejection of systemâ justifying beliefs was an important direct predictor. In Study 2, we replicated many of these findings with a sample of 113 college students. In addition, we tested and confirmed the hypothesis that LWA is predicted by openness to experience and is unrelated to RWA, but not that openness plays a stronger role among those with marginalized identities. These two studies together support our overall hypothesis that different personality processes are involved with political mobilization of privileged and marginalized individuals on the right and the left.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141967/1/asap12132_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141967/2/asap12132.pd

Impact demagnetization of the Martian crust: Current knowledge and future directions

The paleomagnetism of the Martian crust has important implications for the history of the dynamo, the intensity of the ancient magnetic field, and the composition of the crust. Modification of crustal magnetization by impact cratering is evident from the observed lack of a measurable crustal field (at spacecraft altitude) within the youngest large impact basins (e.g., Hellas, Argyre and Isidis). It is hoped that comparisons of the magnetic intensity over impact structures, forward modeling of subsurface magnetization, and experimental results of pressure-induced demagnetization of rocks and minerals will provide constraints on the primary magnetic mineralogy in the Martian crust. Such an effort requires: (i) accurate knowledge of the spatial distribution of the shock pressures around impact basins, (ii) crustal magnetic intensity maps of adequate resolution over impact structures, and (iii) determination of demagnetization properties for individual rocks and minerals under compression. In this work, we evaluate the current understanding of these three conditions and compile the available experimental pressure demagnetization data on samples bearing (titano-) magnetite, (titano-) hematite, and pyrrhotite. We find that all samples demagnetize substantially at pressures of a few GPa and that the available data support significant modification of the crustal magnetic field from both large and small impact events. However, the amount of demagnetization with applied pressure does not vary significantly among the possible carrier phases. Therefore, the presence of individual mineral phases on Mars cannot be determined from azimuthally averaged demagnetization profiles over impact basins at present. The identification of magnetic mineralogy on Mars will require more data on pressure demagnetization of thermoremanent magnetization and forward modeling of the crustal field subject to a range of plausible initial field and demagnetization patterns.United States. National Aeronautics and Space Administration (NNG04GD17G)United States. National Aeronautics and Space Administration (NNX07AQ69G)United States. National Aeronautics and Space Administration (NNX06AD14G

Structural insights into the calcium-dependent interaction between calbindin-D28K and caspase-3

AbstractThe regulation of apoptosis involves a complicated cascade requiring numerous protein interactions including the pro-apoptotic executioner protein caspase-3 and the anti-apoptotic calcium-binding protein calbindin-D28K. Using isothermal titration calorimetry, we show that calbindin-D28K binds caspase-3 in a Ca2+-dependent fashion. Molecular docking and conformational sampling studies of the Ca2+-loaded capase-3/calbindin-D28K interaction were performed in order to isolate potentially crucial intermolecular contacts. Residues in the active site loops of caspase-3 and EF-hands 1 and 2 of calbindin-D28K were shown to be critical to the interaction. Based on these studies, a model is proposed to help understand how calbindin-D28K may deactivate caspase-3 upon binding.Structured summary of protein interactionsCalbindin-D28K and Caspase-3 bind by isothermal titration calorimetry (View interaction

The average laboratory samples a population of 7,300 Amazon Mechanical Turk workers

Using capture-recapture analysis we estimate the effective size of the active Amazon Mechanical Turk (MTurk) population that a typical laboratory can access to be about 7,300 workers. We also estimate that the time taken for half of the workers to leave the MTurk pool and be replaced is about 7 months. Each laboratory has its own population pool which overlaps, often extensively, with the hundreds of other laboratories using MTurk. Our estimate is based on a sample of 114,460 completed sessions from 33,408 unique participants and 689 sessions across seven laboratories in the US, Europe, and Australia from January 2012 to March 2015

Ethanol-induced Modulation of Hepatocellular Extracellular Signal-regulated Kinase-1/2 Activity via 4-Hydroxynonenal

Modulation of the extracellular signal-regulated kinases (ERK-1/2), a signaling pathway directly associated with cell proliferation, survival, and homeostasis, has been implicated in several pathologies, including alcoholic liver disease. However, the underlying mechanism of ethanol-induced ERK-1/2 modulation remains unknown. This investigation explored the effects of ethanol-associated oxidative stress on constitutive hepatic ERK-1/2 activity and assessed the contribution of the lipid peroxidation product 4-hydroxynonenal (4-HNE) to the observations made in vivo. Constitutive ERK-1/2 phosphorylation was suppressed in hepatocytes isolated from rats chronically consuming ethanol for 45 days. This observation was associated with an increase in 4-HNE-ERK monomer adduct concentration and a hepatic cellular and lobular redistribution of ERK-1/2 that correlated with 4-HNE-protein adduct accumulation. Chronic ethanol consumption was also associated with a decrease in hepatocyte nuclear ELK-1 phosphorylation, independent of changes in total nuclear ELK-1 protein. Primary hepatocytes treated with concentrations of 4-HNE consistent with those occurring during oxidative stress displayed a concentration-dependent decrease in constitutive ERK-1/2 phosphorylation, activity, and nuclear localization that negatively correlated with 4-HNE-ERK-1/2 monomer adduct accumulation. These data paralleled the decreased phosphorylation of the downstream kinase ELK-1. Molar ratios of purified ERK-2 to 4-HNE consistent with pathologic ratios found in vivo resulted in protein monomer-adduct formation across a range of concentrations. Collectively, these data demonstrate a novel association between ethanol-induced lipid peroxidation and the inhibition of constitutive ERK-1/2, and suggest an inhibitory mechanism mediated by the lipid peroxidation product 4-hydroxynonenal

Polls and elections: Is Loyalty a Powerful Thing? Republican Senate Campaign Strategy and Trump Coattails in the 2016 Election

Presidential candidates provide a boost to their congressional candidate counterparts, in which congressional candidates should ride the proverbial coattails into office (Campbell and Sumners 1990; Stewart 1989). The 2016 election, however, provides an instance in which the presidential coattails were less than desirable. In this article, we argue that state politics determines the optimal strategy for how candidates should position themselves vis‐à‐vis a controversial presidential candidate. Based on our findings, voters rewarded candidates at varying levels for distancing themselves from then candidate Trump. Specifically, the disloyal strategy, in which candidates completely disavowed Trump, worked best in swing states and among Democrats, liberals, and Clinton voters. The ambiguous strategy, in which candidates took an unclear position on Trump, was less effective, but still received gains in appeal among independents and liberals