Discovery of a Double Radio Relic in ZwCl1447.2+2619: A Rare Testbed for Shock-acceleration Models with a Peculiar Surface-brightness Ratio

We report a discovery of a double radio relic in the cluster merger ZwCl1447.2+2619 (z = 0.376) with uGMRT observations at 420 MHz and 700 MHz. The linear sizes of the northern and southern relics are ∼0.3 Mpc and ∼1.2 Mpc, respectively, which is consistent with the theoretical expectation that a larger relic is produced in the less massive subcluster side. However, ZwCl1447.2+2619 is unlike other known double radio relic systems, where the larger relics are much more luminous by several factors. In this merger, the higher surface brightness of the smaller northern relic makes its total radio luminosity comparable to that of the much larger southern relic. The surface brightness ratio ∼0.1 between the two radio relics differs significantly from the relation observed in other double radio relic systems. From our radio spectral analysis, we find that both relics signify similar weak shocks with Mach numbers of 2.9 ± 0.8 and 2.0 ± 0.7 for the northern and southern relics, respectively. Moreover, the northern relic is connected to a discrete radio source with an optical counterpart, which indicates the possible presence of cosmic-ray injection and reacceleration. Therefore, we propose that this atypical surface brightness ratio can be explained with the particle acceleration efficiency precipitously dropping in the weak shock regime and/or with reacceleration of fossil cosmic rays. Our multi-wavelength analysis and numerical simulation suggest that ZwCl1447.2+2619 is a postmerger, which has experienced a near head-on collision ∼0.7 Gyr ago.

UV Absorption by Silicate Cloud Precursors in Ultra-hot Jupiter WASP-178b

Aerosols have been found to be nearly ubiquitous in substellar atmospheres. Evidence for the composition and conditions whereby these aerosols form remains limited (Cushing et al. 2006, Saumon & Marley 2008, Burningham 2021). Theoretical models and observations of muted spectral features suggest that silicate clouds play an important role in exoplanets between at least 950 and 2,100 K (Gao et al. 2020). However, some giant planets are thought to be hot enough to avoid condensation of even the most refractory elements (Lothringer et al. 2018, Kitzmann et al. 2018). Here, we present the near-UV transmission spectrum of an ultra-hot Jupiter WASP-178b (~2,450 K), that exhibits significant NUV absorption indicating the presence of gaseous refractory elements in the middle atmosphere. This short-wavelength absorption is among the largest spectral features ever observed in an exoplanet in terms of atmospheric scale heights. Bayesian retrievals indicate the broadband UV feature on WASP-178b is caused by refractory elements including silicon and magnesium bearing species, which are the precursors to condensate clouds at lower temperatures. Silicon in particular has not been detected in exoplanets before, but the presence of SiO in WASP-178b is consistent with theoretical expectation as the dominant Si-bearing species at high temperatures. These observations allow us to re-interpret previous observations of HAT-P-41b and WASP-121b to suggest that silicate cloud formation begins on exoplanets with equilibrium temperatures between 1,950 and 2,350 K.

Response of precipitation extremes to warming: what have we learned from theory and idealized cloud-resolving simulations, and what remains to be learned?

<p><span>In this work, we review recent important advances in our understanding of the response of precipitation extremes to warming from theory and from idealized cloud-resolving simulations. A theoretical scaling for precipitation extremes has been proposed and refined in the past decades, allowing to address separately the contributions from the thermodynamics, the dynamics and the microphysics. Theoretical constraints, as well as remaining uncertainties, associated with each of these three contributions to precipitation extremes, will be discussed. Notably, although to leading order precipitation extremes seem to follow the thermodynamic theoretical expectation in idealized simulations, considerable uncertainty remains regarding the response of the dynamics and of the microphysics to warming, and considerable departure from this theoretical expectation is found in observations and in more realistic simulations. We also emphasize key outstanding questions, in particular the response of mesoscale convective organization to warming. Observations suggest that extreme rainfall often comes from organized system in very moist environments. Improved understanding of the physical processes behind convective organization is needed in order to achieve accurate extreme rainfall prediction in our current, and in a warming climate. </span></p>

Self-regulation and Self-identity Changes among Iranian EFL Learners

The present study aims to investigate the probable association between self-regulated strategies and self-identity changes among Iranian EFL learners. To achieve this purpose, 80 EFL students were selected according to convenience sampling from different language institutes in Mashhad. They were requested to complete the ' Motivated Strategies for Learning Questionnaires' (MSLQ) and 'Self-identity Changes' questionnaires. The findings yielded via correlation supported the theoretical expectation of a linkage between self-regulation and self-identity changes. The result revealed that there is a significant relationship between teachers' self-regulation high scores and self-confidence changes. Subsequent data from step-wise regression indicated that among sub-components of self-regulation, regulation, efficacy, and intrinsic value are the best predictors of learners' self-confidence changes. The conclusions and implications of the research are further discussed with reference to earlier finding.

An Algorithm of Tracking and Controlling Network Attack Node based on Adaptive Neural Networks

In order to obtain certain and comprehensive information for formulating network attack strategy, a complex network attack method is proposed in this paper. The attackers’ income, loss, cost and encountered risk in network attack are analyzed and index system is established to evaluate attack effect of network node with dynamic Bayesian network. This method can overcome defects of static evaluation which is relied on single index of network topology. Simulation experiment shows that this method combines more nodes and observation during the attack. It can avoid the gap between actual attack effect and theoretical expectation when attack is implemented by relying on static evaluation. In the meanwhile, it is more accurate in attack precision and of high attack efficiency

Persons as Effect Sizes

Traditional indices of effect size are designed to answer questions about average group differences, associations between variables, and relative risk. For many researchers, an additional, important question is, “How many people in my study behaved or responded in a manner consistent with theoretical expectation?” We show how the answer to this question can be computed and reported as a straightforward percentage for a wide variety of study designs. This percentage essentially treats persons as an effect size, and it can easily be understood by scientists, professionals, and laypersons alike. For instance, imagine that in addition to d or η2, a researcher reports that 80% of participants matched theoretical expectation. No statistical training is required to understand the basic meaning of this percentage. By analyzing recently published studies, we show how computing this percentage can reveal novel patterns within data that provide insights for extending and developing the theory under investigation.

Testing gravity using galaxy-galaxy lensing and clustering amplitudes in KiDS-1000, BOSS, and 2dFLenS

The physics of gravity on cosmological scales affects both the rate of assembly of large-scale structure and the gravitational lensing of background light through this cosmic web. By comparing the amplitude of these different observational signatures, we can construct tests that can distinguish general relativity from its potential modifications. We used the latest weak gravitational lensing dataset from the Kilo-Degree Survey, KiDS-1000, in conjunction with overlapping galaxy spectroscopic redshift surveys, BOSS and 2dFLenS, to perform the most precise existing amplitude-ratio test. We measured the associated EG statistic with 15 − 20% errors in five Δz = 0.1 tomographic redshift bins in the range 0.2 < z < 0.7 on projected scales up to 100 h−1 Mpc. The scale-independence and redshift-dependence of these measurements are consistent with the theoretical expectation of general relativity in a Universe with matter density Ωm = 0.27 ± 0.04. We demonstrate that our results are robust against different analysis choices, including schemes for correcting the effects of source photometric redshift errors, and we compare the performance of angular and projected galaxy-galaxy lensing statistics.

Naval Power and Effects of Third-Party Trade on Conflict

This study argues that the effect of third-party trade on dyadic conflicts is conditional on the naval power of both the potential conflict initiator and its target state. This conditional effect occurs mainly because naval power allows trade-integrated initiators to reduce their trade dependence on a given trade partner and its allies more easily. At the same time, the target’s naval power increases the costs that conflict inflict on the initiator’s trade. As maritime trade accounts for about 80 percent of world trade volume, naval capability has an important effect on combatant states’ ability to substitute trading partners during a conflict and to mitigate trade-related costs, thereby affecting the relationship between third-party trade and conflict. The findings of our statistical analyses support our theoretical expectation that the pacifying effect of third-party trade diminishes as the initiator’s naval power increases, yet increases as the naval power of the potential target increases.

Defending core values: Human rights and the extradition of fugitives

Are states willing to overlook human rights violations to reap the fruits of international cooperation? Existing research suggests that this is often the case: security, diplomatic, or commercial gains may trump human rights abuse by partners. We argue, however, that criminal-justice cooperation might be obstructed when it undermines core values of individual freedoms and human rights, since the breach of these values exposes the cooperating state to domestic political resistance and backlash. To test our argument, we examine extradition: a critical tool for enforcing criminal laws across borders, but one that potentially threatens the rights of surrendered persons, who could face physical abuse, unfair trial, or excessive punishment by the foreign legal system. We find support for our theoretical expectation through statistical analysis of the surrender of fugitives within the European Union as well as surrenders to the United States: greater respect for human rights correlates with the surrender of fewer persons. A case study of Britain confirms that human rights concerns may affect the willingness to extradite. Our findings have important implications for debates on the relationship between human rights and foreign policy as well as the fight against transnational crime.

MALAYSIAN AUDIENCES REACTION OF NEWS FRAME SETTING TOWARDS LGBT ISSUES

The trending and increasing openness of news reporting has caused the media industry to shift and increasingly report news that was once considered taboo to the mass audiences. The high acceptance and rate of feedback from the readers boost the rate of coverage on taboo issues. Lesbian, Gay, Bisexual, and Transgender or commonly known as LGBT is an issue that is gaining traction on online news portals. Therefore, the main aim of this conceptual article is to discuss the effects of news presentation regarding this issue using the framing theory from three main aspects which are (i) cognitive (ii) response (attitude) and (iii) behavior (acceptance or rejection). This study can be used to shape a theoretical expectation of LGBT issues that are being presented by an online news portal today.