Research on mobile-assisted language learning (MALL) has revealed that high rates of attrition among users can undermine the potential benefits of this learning method. To explore this issue, we surveyed 3,670 adult MALL users based on the Unified Theory of Acceptance and Use of Technology (UTAUT) and also conducted an in-depth analysis of their historical app usage data. The results of hierarchical k-means cluster analysis and recurrent event survival analysis revealed three major findings. First, three distinct profiles of learners were characterized by different MALL acceptance and engagement experiences. Second, those with greater MALL acceptance displayed more intense, frequent, and durable app usage (behavioral engagement). Lastly, high levels of MALL acceptance were associated with more frequent pauses in app usage but also (a) longer active usage, (b) shorter breaks before returning to the app, and, ultimately, (c) fewer dropouts. We argue that persistence is a multidimensional process involving cyclical phases of engagement, disengagement, dormancy, and reengagement, with each aspect, like intensity, frequency, and duration, building up cumulatively over time. Implications for promoting persistent MALL engagement are discussed.

We obtain asymptotic formulas for the number of matrices in the congruence subgroup

$$\begin{align*}\Gamma_0(Q) = \left\{ A\in\operatorname{SL}_2({\mathbb Z}):~c \equiv 0 \quad\pmod Q\right\}, \end{align*}$$

Contemplating how the familiar trope of the “bad Black mother” is used to surveil, punish, and scorn Black maternal subjects this article considers how good motherhood is at once aspirational and coercive for Black mothers who are disciplined by the ever looming threat of badness and the unattainable promise of goodness. Stretching contemporary Black feminist analyses of how Black maternal revolt against anti-Black logics can be witnessed through forms of mortal sacrifice that secure future Black life, this article troubles ideals of sacrifice through an auto-ethnographic reading of maternal death as a respite from the continuous labors of goodness for the subject that tires under the relentless force of racism and its anticipations of bad Black motherhood. Badness is then explored, through personal narrative, as a form of affective resistance against the drudgery of willing towards goodness as the maternal refuses to discipline their discontent.

Tropical drylands are characterized by extreme environmental conditions that, coupled with anthropogenic habitat degradation, can limit the occurrence of native species. Species that are most sensitive to these pressures may be prone to disappear in the context of climate change. In this study, we evaluated the influence of environmental and anthropogenic variables on the occurrence of large mammals and birds at the Tatacoa Desert, an arid region in central Colombia. We tested the relationship between the magnitude of the species’ responses to environmental, human-related variables and to body mass, and percentage of carnivory. Overall, we found a positive association between forest cover and the occupancy of the largest mammals (> 8kg), negative associations between solar radiation and human footprint with individual species occupancy, and a positive association of species occupancy with distance to touristic sites. Our results suggest that the largest and/or more carnivore species may be affected positively by forest cover and negatively by intense solar radiation highlighting the consequences of the increasing process of desertification on large mammals and birds at the upper Magdalena River basin of Colombia under the current scenario of global climate change.

Divisorial stability of a polarised variety is a stronger – but conjecturally equivalent – variant of uniform K-stability introduced by Boucksom–Jonsson. Whereas uniform K-stability is defined in terms of test configurations, divisorial stability is defined in terms of convex combinations of divisorial valuations on the variety.

We consider the behaviour of divisorial stability under finite group actions and prove that equivariant divisorial stability of a polarised variety is equivalent to log divisorial stability of its quotient. We use this and an interpolation technique to give a general construction of equivariantly divisorially stable polarised varieties.

Pi-d2, which encodes a potential serine-threonine receptor-like kinase (RLK) membrane-spanning protein consisting of 825 amino acids, confers resistance to Magnaporthe oryzae strain ZB15 via an unidentified recognition mechanism. In this study, the Pid2 alleles of 303 rice (O. sativa) varieties from China's Yunnan region were amplified and sequenced in order to produce 24 haplotypes and 16 translation variants. Six of twenty-four alleles possessing the resistant site at the 441st amino acid were chosen for evaluating blast resistance by transforming into the blast-vulnerable rice variety Nipponbare. After being infected with 11 strains of M. oryzae, all transgenic lines exhibited resistance to ZB-15, whereas resistance to other strains varied. Notably, Pi-d2_H23 and Pi-d2_H24 exhibited resistance to all M. oryzae strains tested, indicating that these two alleles may have a broader resistance spectrum to M. oryzae. Alignment of these alleles’ amino acid sequences revealed that the differences in blast resistance spectra were primarily related to the amino acids present in the PAN domain at position 363 (valine/alanine). These findings suggested that the two extracellular signal recognition domains of PI-D2, B-lectin and PAN, may play a role in the identification of M. oryzae effectors. The present results provide insight into the mechanism of interaction between RLKs and M. oryzae.

In this paper we test how much party labels influence vote choices between candidates when voters have access to realistically distributed information about candidate positions and demographics. We do not seek to adjudicate a long-running debate about the role of party labels, but present some nuances on the two archetypal theoretical views on vote choices. We use data from the Representative Audit of Britain (RAB) and the British Elections Study (BES) to generate electoral match-ups between randomly selected Conservative versus Labour candidates, with only half of respondents seeing party labels in addition to candidates’ positions and demographics. For our experiment fielded in October 2021, we find negligible to moderate effects of party labels on vote choices. Our results suggest the information on candidate positions and party labels largely act as substitutes for one another, with only modest changes when party labels are made explicit.

The high-pressure behaviour of inderborite [ideally CaMg[B3O3(OH)5]2(H2O)4⋅2H2O, space group C2/c with a ≈ 12.14, b ≈ 7.43, c ≈ 19.23 Å and β ≈ 90.3° at room conditions] has been studied by two in situ single-crystal synchrotron X-ray diffraction experiments up to ~10 GPa, using He as pressure-transmitting fluid. Between 8.11(5) and 8.80(5) GPa, inderborite undergoes a first-order phase transition to its high-pressure polymorph, inderborite-II (with a ≈ 11.37, b ≈ 6.96, c ≈ 17.67 Å, β ≈ 96.8° and ΔV ≈ 7.0%, space group unknown). The isothermal bulk modulus (KV0 = β−1P0,T0, where βP0,T0 is the volume compressibility coefficient) of inderborite was found to be KV0 = 41(1) GPa. The destructive nature of the phase transition prevented any structure resolution of inderborite-II or even the continuation of the experiments at pressures higher than 10.10(5) GPa. In the pressure range 0–8.11(5) GPa, the compressional anisotropy of inderborite, indicated by the ratio between the principal components of the Eulerian finite unit-strain ellipsoid, is ɛ1:ɛ2:ɛ3 = 1.4:1.05:1. The deformation mechanisms at the atomic scale in inderborite are here described. Our findings support the hypothesis of a quasi-linear correlation between the total H2O content and P-stability range in hydrated borates, as the pressure at which inderborite undergoes the phase transition falls in line with most of the hydrate borates studied at high-pressure so far.

This article argues for a more diverse approach to the appearance of enslaved persons in Greek historiography through an analysis of the Persian navy's battlefield tour of Thermopylae in Book 8 of Herodotus’ Histories. Previous approaches to slavery in Greek historiography have rightly commented on the cultural awkwardness to Greek authors of slaves’ extensive involvement in ancient warfare. However, this is only one aspect of how slaves featured in historiographical narrative. Herodotus continually problematizes the methods of enquiry and many characters within his work engage in enquiry-like activities. Book 8 itself is no different, with much of the action involving errors in human perception. The appearance of helots amongst the heroic dead at Thermopylae is intended both as a narrative reveal, since their presence has not previously been known to the reader, and as a comment on the contestation of Greek identity, which is framed at the start of Book 8 with a series of direct addresses to different groups of Greeks, all of whom take a different approach to their participation in the Persian Wars. Hence what appears to be an incidental detail can in fact be understood in the wider, thematic context of the Histories and especially that of the books concerning the Persian Wars.

The Ethiopian core collection of the USDA-Agriculture Research Service, National Plant Germplasm System (NPGS) includes 376 accessions and a genomic characterization that revealed 151,210 single nucleotide polymorphisms. This collection, however, lacks phenotypic characterization for several important agriculture traits. A total of 330 accessions from this NPGS Ethiopian core set were evaluated for grain mould resistance response across four tropical environments. Most of the accessions in the NPGS Ethiopian collection showed susceptibility to grain mould based on the low emergence rate and high seed deterioration observed in the seeds. The population structure of the collection was not related to grain mould resistance response suggesting this germplasm originated in regions with low disease pressure. The analysis identified two accessions with high emergence (PI 457867 and PI 454221) and three (PI 455036, PI 455213 and PI 330821) with low seed degradation. Genome-wide association analysis found genomic regions in chromosome 1, 3 and 8 associated with the observed grain mould resistance variation. Candidate gene analysis within these three loci identified diseases resistance genes involved in pathogen recognition and signalling cascades of the plant immunity system. These five NPGS Ethiopian accessions are candidates for use in a pre-breeding germplasm programme to develop improved germplasm with grain mould resistance.

Path planning for the unmanned aerial vehicle (UAV) is to assist in finding the proper path, serving as a critical role in the intelligence of a UAV. In this paper, a path planning for UAV in three-dimensional environment (3D) based on enhanced gravitational search algorithm (EGSA) is put forward, taking the path length, yaw angle, pitch angle, and flight altitude as considerations of the path. Considering EGSA is easy to fall into local optimum and convergence insufficiency, two factors that are the memory of current optimal and random disturbance with chaotic levy flight are adopted during the update of particle velocity, improving the balance between exploration and exploitation for EGSA through different time-varying characteristics. With the identical cost function, EGSA is compared with seven peer algorithms, such as moth flame optimization algorithm, gravitational search algorithm, and five variants of gravitational search algorithm. The experimental results demonstrate that EGSA is superior to the seven comparison algorithms on CEC 2020 benchmark functions and the path planning method based on EGSA is more valuable than the other seven methods in diverse environments.

We report a case of a residual aortopulmonary window where a new Konar-MF occluder device was used to close the defect. This device has a low profile and conforms to the anatomy of aortopulmonary window very nicely without unnecessary protrusion on either side. This report highlights the advantage of Konar-MF occluder device for closure of such defects.