Hadean zircon formed due to hydrated ultramafic protocrust melting

Hadean zircons, from the Jack Hills (Western Australia) and other localities, are currently the only window into the earliest terrestrial felsic crust, the formation of which remains enigmatic. Based upon new experimental results, generation of such early crust has been hypothesized to involve the partial melting of hydrated peridotite interacting with basaltic melt at low pressure (<10 km), but it has yet to be demonstrated that such liquids can indeed crystallize zircons comparable to Jack Hills zircon. We used thermodynamic and geochemical modeling to test this hypothesis. The predicted zircon saturation temperatures of <750 °C, together with the model zircon Th, U, Nb, Hf, Y, and rare earth element (REE) contents at 700 °C, δ18OVSMOW (Vienna standard mean ocean water) signatures, and co-crystallizing mineral assemblage were compared to those of the Jack Hills zircon. This comparison was favorable with respect to crystallization temperature, most trace-element contents, and mineral inclusions in zircon. The discrepancy in δ18OVSMOW signatures may be explained by hotter conditions of Hadean protocrust hydration. Our work supports the idea that felsic magma generation at shallow depths involving a primordial weathered ultramafic protocrust and local basaltic intrusions is indeed a viable mechanism for the formation of felsic crust on early Earth.

Detection of Security Attacks in Industrial IoT Networks: A Blockchain and Machine Learning Approach

Internet of Things (IoT) networks have been integrated into industrial infrastructure schemes, positioning themselves as devices that communicate highly classified information for the most critical companies of world nations. Currently, and in order to look for alternatives to mitigate this risk, solutions based on Blockchain algorithms and Machine Learning techniques have been implemented separately with the aim of mitigating potential threats in IIoT networks. In this paper, we sought to integrate the previous solutions to create an integral protection mechanism for IoT device networks, which would allow the identification of threats, activate secure information transfer mechanisms, and it would be adapted to the computational capabilities of industrial IoT. The proposed solution achieved the proposed objectives and is presented as a viable mechanism for detecting and containing intruders in an IoT network. In some cases, it overcomes traditional detection mechanisms such as an IDS.

EXPRESS: Temporal grouping effects in verbal and musical short-term memory: Is serial order representation domain-general?

The question of the domain-general versus domain-specific nature of the serial order mechanisms involved in short-term memory is currently under debate. The present study aimed at addressing this question through the study of temporal grouping effects in short-term memory tasks with musical material, a domain which has received little interest so far. The goal was to determine whether positional coding—currently the best account of grouping effect in verbal short-term memory—represents a viable mechanism to explain grouping effects in the musical domain. In a first experiment, non-musicians performed serial reconstruction of 6-tone sequences, where half of the sequences was grouped by groups of three items and the other half presented at a regular pace. The overall data pattern suggests that temporal grouping exerts on tone sequences reconstruction the same effects as in the verbal domain, except for ordering errors which were not characterized by the typical increase of interpositions. This pattern has been replicated in two additional experiments with verbal material, using the same grouping structure as in the musical experiment. The findings support that verbal and musical short-term memory domains are characterized by similar temporal grouping effects for the recall of 6-item lists grouped by three, but it also suggests the existence of boundary condition to observe an increase of interposition errors predicted by positional theories.

Plate Tectonics

This chapter illustrates the most significant revolution in the understanding of the Earth discovered in the last 75 years, plate tectonics. The theory of plate tectonics is the second overarching precept of the field of geology (after the geologic time scale). Plate tectonics and its history as a theory are traced in this chapter. Early explorers and others had noticed the apparent fit in the shapes of the continents, but these ideas were not explicitly stated until Alfred Wegener detailed his evidence for the drift of the continents, though he had no viable mechanism on how the drift would have occurred. World War II technology, including sonar and radar, allowed scientists to understand the ocean floor. Rather than a flat, featureless plain, they found a vast undersea mountain range known as the mid-oceanic ridge that wraps around the world like seams on a baseball. Harry Hess proposed a new mechanism for continental drift through mantle convection cells, causing seafloor spreading. These ideas were confirmed by magnetic surveys and subsequent research, leading to the theory of plate tectonics. A final section looks at the maturation of the theory as geologists continue to learn more details about the movement and intricacies of the tectonic plates.

Implementation of a mHealth solution to remotely monitor patients on a cardiac surgical waiting list: service evaluation

Background The emergence of COVID-19 resulted in postponement of nonemergent surgical procedures for cardiac patients in London. mHealth represented a potentially viable mechanism for highlighting deteriorating patients on the lengthened cardiac surgical waiting lists. Objective To evaluate the deployment of a digital health solution to support continuous triaging of patients on a cardiac surgical waiting list. Method An NHS trust utilized an app-based mHealth solution (Huma Therapeutics) to help gather vital information on patients awaiting cardiac surgery (valvular and coronary surgery). Patients at a tertiary cardiac center on a waiting list for elective surgery were given the option to be monitored remotely via a mobile app until their date of surgery. Patients were asked to enter their symptoms once a week. The clinical team monitored this information remotely, prompting intervention for those patients who needed it. Results Five hundred and twenty-five patients were on boarded onto the app. Of the 525 patients using the solution, 51 (9.71%) were identified as at risk of deteriorating based on data captured via the remote patient monitoring platform and subsequently escalated to their respective consultant. 81.7% of patients input at least one symptom after they were on boarded on the platform. Discussion Although not a generalizable study, this change in practice clearly demonstrates the feasibility and potential benefit digital remote patient monitoring can have in triaging large surgical wait lists, ensuring those that need care urgently receive it. We recommend further study into the potential beneficial outcomes from preoperative cardiac mHealth solutions.

Integration of banks and insurance companies activities in Ukraine

The article reveals the essence of modern bancassurance and new challenges and prospects for its development in Ukraine. The definition of “bancassurance” is theoretically substantiated and the general financial and economic characteristics of Ukrainian banks is given. The normative indicators of commercial institutions are analyzed along with the main risks affecting banking and insurance activities, the possibility of their leveling are determined. The study provides theoretical and practical information on the process of banks capital of and insurance companies merging, financial and economic analysis of JSC PrivatBank – one of the largest banks in modern Ukraine, and the assessment of the financial stability of its insurance partners. The insurance Ukrainian market study concerning the detection of possible prospects for cooperation with the studied bank was done. The calculations suggest that PrivatBank can cooperate with the leading insurance companies, such as AXA Insurance and Providna recommended as new partners. It is established that bancassurance technologies have a significant place at the current stage of development of the domestic financial market. Using a large customer base and a wide network of branches and outlets, banking experts expect that revenues from the sale of insurance products in 2021 may amount to 15% of total bank revenues, as the volume of bank insurance in JSC CB PrivatBank is growing quite rapidly. The activity of banks in market conditions is subject to its general laws, and therefore requires the development of a viable mechanism for managing financial activities, aimed at increasing the competitiveness of banks. Thus, the ability of bank managers to determine the degree of financial stability of their bank as well as that of the competing banks and counterparties is essential in making decisions. Therefore, the search for ways to optimize the financial condition of the bank is one of the principles of further rapid development of the banking system in Ukraine.

To BAN or Not to BAN: Bayesian Attention Networks for Reliable Hate Speech Detection

Hate speech is an important problem in the management of user-generated content. To remove offensive content or ban misbehaving users, content moderators need reliable hate speech detectors. Recently, deep neural networks based on the transformer architecture, such as the (multilingual) BERT model, have achieved superior performance in many natural language classification tasks, including hate speech detection. So far, these methods have not been able to quantify their output in terms of reliability. We propose a Bayesian method using Monte Carlo dropout within the attention layers of the transformer models to provide well-calibrated reliability estimates. We evaluate and visualize the results of the proposed approach on hate speech detection problems in several languages. Additionally, we test whether affective dimensions can enhance the information extracted by the BERT model in hate speech classification. Our experiments show that Monte Carlo dropout provides a viable mechanism for reliability estimation in transformer networks. Used within the BERT model, it offers state-of-the-art classification performance and can detect less trusted predictions.

Stabilization of S3O4 at High Pressure-Implications for the Sulfur Excess Paradox

The geological conundrum of “sulfur excess” refers to the finding that predicted amounts of sulfur, in the form of SO2, discharged in volcanic eruptions much exceeds the sulfur available for degassing from the erupted magma. Exploring the source of the excess sulfur has been the subject of considerable interest. Here, from a systematic computational investigation of sulfur oxygen compounds under pressure, a hitherto unknown S3O4 compound containing a mixture of sulfur oxidation states +II and +IV emerges and is predicted to be stabilized above a pressure of 79 GPa. We predict that S3O4 can be produced via multiple redox reactions involving subducted S bearing minerals (e.g., sulfates and sulfides) at high pressure and temperature conditions relevant to the deep lower mantle, and conversely be decomposed into SO2 and S at shallow depths of Earth. Therefore, S3O4 can be considered as a key intermediate compound to promote the decomposition of sulfates to release SO2, which offers an alternative source of the excess sulfur released during explosive eruptions. These findings provide a possible resolution to the geological paradox of “excess sulfur degassing” and a viable mechanism for understanding of S exchange between Earth’s surface and the lower mantle for the deep sulfur cycle.

Tidal disruption events in the first billion years of a galaxy

ABSTRACT Accretion of stars on massive black holes (MBHs) can feed MBHs and generate tidal disruption events (TDEs). We introduce a new physically motivated model to self-consistently treat TDEs in cosmological simulations, and apply it to the assembly of a galaxy with final mass $3\times 10^{10}\, \mathrm{M}_{\odot }$ at z = 6. This galaxy exhibits a TDE rate of $\sim 10^{-5}\, \mathrm{yr}^{-1}$, consistent with local observations but already in place when the Universe was one billion year old. A fraction of the disrupted stars participate in the growth of MBHs, dominating it until the MBH reaches mass $\sim 5 \times 10^5 \, \mathrm{M}_{\odot }$, but their contribution then becomes negligible compared to gas. TDEs could be a viable mechanism to grow light MBH seeds, but fewer TDEs are expected when the MBH becomes sufficiently massive to reach the luminosity of, and be detected as, an active galactic nucleus. Galaxy mergers bring multiple MBHs in the galaxy, resulting in an enhancement of the global TDE rate in the galaxy by ∼1 order of magnitude during $100\, \mathrm{Myr}$ around mergers. This enhancement is not on the central MBH, but caused by the presence of MBHs in the infalling galaxies. This is the first self-consistent study of TDEs in a cosmological environment and highlights that accretion of stars and TDEs are a natural process occurring in a Milky Way-mass galaxy at early cosmic times.

Gravitational production of vector dark matter

A model of vector dark matter that communicates with the Standard Model only through gravitational interactions has been investigated. It has been shown in detail how does the canonical quantization of the vector field in varying FLRW geometry implies a tachyonic enhancement of some of its momentum modes. Approximate solutions of the mode equation have been found and verified against exact numerical ones. De Sitter geometry has been assumed during inflation while after inflation a non-standard cosmological era of reheating with a generic equation of state has been adopted which is followed by the radiation-dominated universe. It has been shown that the spectrum of dark vectors produced gravitationally is centered around a characteristic comoving momentum k⋆ that is determined in terms of the mass of the vector mX, the Hubble parameter during in- flation HI, the equation of state parameter w and the efficiency of reheating γ. Regions in the parameter space consistent with the observed dark matter relic abundance have been determined, justifying the gravitational production as a viable mechanism for vector dark matter. The results obtained in this paper are applicable within various possible models of inflation/reheating with non-standard cosmology parametrized effectively by the corresponding equation of state and efficiency of reheating.