Quantitative Shape-Classification of Misfitting Precipitates during Cubic to Tetragonal Transformations: Phase-Field Simulations and Experiments

The effectiveness of the mechanism of precipitation strengthening in metallic alloys de-pends on the shapes of the precipitates. Two different material systems are considered: tetragonal γ′′ precipitates in Ni-based alloys and tetragonal θ′ precipitates in Al-Cu-alloys. The shape formation and evolution of the tetragonally misfitting precipitates was investigated by means of experiments and phase-field simulations. We employed the method of invariant moments for the consistent shape quantification of precipitates obtained from the simulation as well as those obtained from the experiment. Two well-defined shape-quantities are proposed: (i) a generalized measure for the particles aspect ratio and (ii) the normalized λ2, as a measure for shape deviations from an ideal ellipse of the given aspect ratio. Considering the size dependence of the aspect ratio of γ′′ precipitates, we find good agreement between the simulation results and the experiment. Further, the precipitates’ in-plane shape is defined as the central 2D cut through the 3D particle in a plane normal to the tetragonal c-axes of the precipitate. The experimentally observed in-plane shapes of γ′′-precipitates can be quantitatively reproduced by the phase-field model. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

RARITAN FORMATION (UPPER CRETACEOUS), LONG ISLAND, NEW YORK: SEDIMENTOLOGICAL AND GEOCHEMICAL ASSESSMENT

The lithology of the Upper Cretaceous Raritan Formation (RF) consists of two members: an upper clay member (Raritan clay) and a lower unit, the Lloyd Sand Member. RF is unconformably overlain by upper Pleistocene glacial deposits. The RF consists of stratified white, light- to dark-gray, and red beds and lenses of clay, silt, and sand; lignite and pyrite are common. Variegated, thin to thickly-bedded Lloyd sandstone (LS) is considered to be one of the extensive regional aquifers in Long Island and interpreted to be nearshore, fluvio-deltaic deposit. Proximity to fluvial axes and active deltaic lobes plays an important role in sequence thickness and maintaining an overall architecture of deltaic sandbodies. Presumably large amounts of deltaically derived sand are reworked by wave action and redistributed by longshore currents. LS is generally identified as containing clayey lenses, pyrite and hematitic, highly micaceous reddish silty sandstone. Its upper surface lies about 400 feet below sea level in northwest Huntington and at Orient, and over 1,500 feet below sea level at western Fire Island. The exposed unit is about 30 m thick in Caumsett State Park, Long Island. Preliminary geochemical investigations using ICP-MS (Inductively coupled plasma mass spectrometry), Ultra Trace Aqua Regia ICP-MS, and routine petrography on selected samples (both outcrop and subsurface) revealed a distinctive geochemical signature associated with RF units (Raritan Clay and Lloyd Sandstone). Clay unit known as Raritan Clay contains 60-42% silica, 27-15% alumina, 7% iron-oxide, and 3% K2O, whereas LS is found to be dominantly silica rich (97%) and remarkably poor in alumina, iron-oxide, and K2O. RF clayey unit also showed LOI to be 7-40%. Field exposure of RF clay resembles a kaolinitic-illitic type of high plasticity. Selected trace elements were identified and include Zr, Cu, Ti, Rb, La, Ba, Sr, Ce, Cr, Y, and Zn. Clayey units in RF were found to contain significantly higher proportion of Cu (80-30 ppm), Rb (35-15 ppm), Ba (80-40 ppm), Ce (105 ppm), Cr (60-20 ppm), Y (30 ppm) and Zn (200-40 ppm), compared to LS. Distinctive geochemical variations between the RF clay and LS point to variable provenance, diagenetic pathways, and depositional environments. Further investigations will proceed to differentiate subunits within the LS and RF clayey unit

Superposition of Weyl solutions: The equilibrium forces

Solutions to the Einstein equation that represent the superposition of static isolated bodies with axially symmetry are presented. The equations nonlinearity yields singular structures (strut and membranes) to equilibrate the bodies. The force on the strut like singularities is computed for a variety of situations. The superposition of a ring and a particle is studied in some detailComment: 31 pages, 7 figures, psbox macro. Submitted to Classical and Quantum Gravit

Hasbara 2.0: Israel’s Public Diplomacy in the Digital Age

The Internet has been a counter-public space for Palestinian liberation politics for over a decade, and digital technologies have become an increasingly important tool for solidarity groups across the world. However, the Israeli state and Zionist supporters worldwide are harnessing the same technologies and platforms to mobilize technology primarily to increase pro-Israel sentiments. The aims of this article are to examine hasbara [Israeli public diplomacy] through an exploration of similar diplomacy programmes; to illustrate how social media have affected the basic algorithms of hasbara; and to probe the assertions of hasbara in the light of pro-Palestinian solidarity. Through a study of public diplomacy, this article critically analyzes hasbara as a site of contestation and a method that is hampered by contradictions. On the one hand, there has been a massive growth in hasbara in recent years—indicated by the increase in funding for it and by its professionalized and centralized character; and on the other hand, hasbara has attracted sharp critiques in Israel for its reputed failures. To understand this contradiction, hasbara must be placed within the context of Israel’s settler-colonialism, which sets the state apart from other ‘post-conflict’ states. This article reviews the methods utilized in hasbara, as well as their readjustment in the context of recent wars. Events in 2014 illustrate that hasbara actually destabilizes Israel’s diplomacy. Online journalism and the suppression of solidarity for Palestine together stimulate more criticism and, in turn, help to shift public opinion. Paradoxically, therefore, adjustments (‘hasbara 2.0’) have underlined the image of Israel as a colonial power engaged in violent occupation

Changes in global and thalamic brain connectivity in LSD-induced altered states of consciousness are attributable to the 5-HT2A receptor

Background:Lysergic acid diethylamide (LSD) has agonist activity at various serotonin (5-HT) and dopamine receptors. Despite the therapeutic and scientific interest in LSD, specific receptor contributions to its neurobiological effects remain unknown. Methods: We therefore conducted a double-blind, randomized, counterbalanced, cross-over study (ClinicalTrials.gov, NCT02451072) during which 24 healthy human participants received either (i) placebo+placebo, (ii) placebo+LSD (100 µg po), or (iii) Ketanserin, a selective 5-HT receptor antagonist,+LSD. We quantified resting-state functional connectivity via a data-driven global brain connectivity method and compared it to cortical gene expression maps. Findings: LSD reduced associative, but concurrently increased sensory-somatomotor brain-wide and thalamic connectivity. Ketanserin fully blocked the subjective and neural LSD effects. Whole-brain spatial patterns of LSD effects matched 5-HT receptor cortical gene expression in humans. Conclusion: Together, these results strongly implicate the 5-HT receptor in LSD's neuropharmacology. This study therefore pinpoints the critical role of 5-HT in LSD's mechanism, which informs its neurobiology and guides rational development of psychedelic-based therapeutics. Funding: Swiss National Science Foundation (SNSF, P2ZHP1_161626, KHP), the Swiss Neuromatrix Foundation (2015 - 0103, FXV), the Usona Institute (2015 - 2056, FXV), the NIH (R01MH112746, JDM; DP5OD012109, AA; R01MH108590, AA), the NIAA ( P50AA012870-16, AA & JHK), the NARSAD Independent Investigator Grant (AA), the Yale CTSA grant (UL1TR000142 Pilot Award, AA), and the Slovenian Research Agency (ARRS J7-6829 & ARRS J7-8275, GR)

Corporate governance and financial constraints on strategic turnarounds

The paper extends the Robbins and Pearce (1992) two-stage turnaround response model to include governance factors. In addition to the retrenchment and recovery, the paper proposes the addition of a realignment stage, referring specifically to the re-alignment of expectations of principal and agent groups. The realignment stage imposes a threshold that must be crossed before the retrenchment and hence recovery stage can be entered. Crossing this threshold is problematic to the extent that the interests of governance-stakeholder groups diverge in a crisis situation. The severity of the crisis impacts on the bases of strategy contingent asset valuation leading to the fragmentation of stakeholder interests. In some cases the consequence may be that management are prevented from carrying out turnarounds by governance constraints. The paper uses a case study to illustrate these dynamics, and like the Robbins and Pearce study, it focuses on the textile industry. A longitudinal approach is used to show the impact of the removal of governance constraints. The empirical evidence suggests that such financial constraints become less serious to the extent that there is a functioning market for corporate control. Building on governance research and turnaround literature, the paper also outlines the general case necessary and sufficient conditions for successful turnarounds

Arginase impairs hypoxic pulmonary vasoconstriction in murine endotoxemia

Background: Hypoxic pulmonary vasoconstriction (HPV) optimizes the match between ventilation and perfusion in the lung by reducing blood flow to poorly ventilated regions. Sepsis and endotoxemia impair HPV. We previously showed that nitric oxide synthase 2 (NOS2) is required, but not sufficient, for the effect of endotoxin on HPV. The aim of the current study was to identify additional factors that might contribute to the impairment of HPV during endotoxemia. Methods: Gene expression profiling was determined using pulmonary tissues from NOS2-deficient (NOS2−/−) and wild-type mice subjected to endotoxin or saline challenge (control). HPV was accessed as the percentage increase in left pulmonary vascular resistance (LPVR) in response to left main bronchus occlusion (LMBO) in wild-type mice. Results: Among the 22,690 genes analyzed, endotoxin induced a greater than three-fold increase in 59 and 154 genes in the lungs of wild-type and NOS2−/− mice, respectively. Of all the genes induced by endotoxin in wild-type mice, arginase 1 (Arg1) showed the greatest increase (16.3-fold compared to saline treated wild-type mice). In contrast, endotoxin did not increase expression of Arg1 in NOS2−/− mice. There was no difference in the endotoxin-induced expression of Arg2 between wild-type and NOS2-deficient mice. We investigated the role of arginase in HPV by treating the mice with normal saline or the arginase inhibitor Nω-hydroxy-nor-L-arginine (norNOHA). In control mice (in the absence of endotoxin) treated with normal saline, HPV was intact as determined by profound LMBO-induced increase in LPVR (121 ± 22% from baseline). During endotoxemia and treatment with normal saline, HPV was impaired compared to normal saline treated control mice (33 ± 9% vs. 121 ± 22%, P < 0.05). HPV was restored in endotoxin-exposed mice after treatment with the arginase inhibitor norNOHA as shown by the comparison to endotoxemic mice treated with normal saline (113 ± 29% vs, 33 ± 9%, P < 0.05) and to control mice treated with normal saline (113 ± 29% vs, 121 ± 22%, P = 0.97). Conclusions: The results of this study suggest that endotoxemia induces Arg1 and that arginase contributes to the endotoxin-induced impairment of HPV in mice