Let $G = K \rtimes \langle t \rangle $ be a finitely generated group where K is abelian and $\langle t\rangle$ is the infinite cyclic group. Let R be a finite symmetric subset of K such that $S = \{ (r,1),(0,t^{\pm 1}) \mid r \in R \}$ is a generating set of G. We prove that the spherical conjugacy ratio, and hence the conjugacy ratio, of G with respect to S is 0 unless G is virtually abelian, confirming a conjecture of Ciobanu, Cox and Martino in this case. We also show that the Baumslag–Solitar group $\mathrm{BS}(1,k)$, $k\geq 2$, has a one-sided Følner sequence F such that the conjugacy ratio with respect to F is non-zero, even though $\mathrm{BS}(1,k)$ is not virtually abelian. This is in contrast to two-sided Følner sequences, where Tointon showed that the conjugacy ratio with respect to a two-sided Følner sequence is positive if and only if the group is virtually abelian.

Time-varying flow separation on an accelerating prolate spheroid has been studied at various angles of incidence. Instantaneous pressure and scanning stereoscopic particle image velocimetry were used to shed light on the evolution of cross-flow structures for the Reynolds number ($Re$) range of $1.0\times 10^6\leq Re \leq 1.5\times 10^6$. The movement of separation lines is examined for various model accelerations to investigate on the interplay between acceleration and flow separation. The results demonstrate that for axial accelerations, the streamwise pressure distribution in the rear part of the prolate spheroid switches from an adverse to a favourable pressure gradient. At the same time, the circumferential adverse pressure gradient present during steady motion vanishes during said accelerations. In contrast, both streamwise and circumferential adverse pressure gradients strengthen when the model is axially decelerated. These dynamic pressure distributions influence the location of the separation line, which in turn moves closer to the model meridian during accelerations while moving outwards during decelerations. The streamwise vorticity distribution and the streamwise circulation both show how the separation-line position impacts the vortex formation. A high-vorticity region near the model surface is established during acceleration. In contrast, a decelerating model leads to transport of high-vorticity fluid into the outer area of the cross-flow separation. We further assess the memory effects following the near-impulsive velocity changes. The cross-flow retains the memory of moving separation lines shortly after the acceleration. However, the separation recovers quickly to a steady state.

We study a retirement savings plan with a default contribution rate of 12 percent of income, which is much higher than previously studied defaults. Twenty-five percent of employees had not opted out of this default 12 months after hire; a literature review finds that the corresponding fraction in plans with lower defaults is approximately one-half. Because only contributions above 12 percent were matched by the employer, 12 percent was likely to be a suboptimal contribution rate for employees. Employees who remained at the 12 percent default contribution rate had average income that was approximately one-third lower than would be predicted from the relationship between salaries and contribution rates among employees who were not at 12 percent. Defaults may influence low-income employees more strongly in part because these employees face higher psychological barriers to active decision making.

The Rhynchonellida is a major group of brachiopods that survived the “big five” mass extinctions and flourished after the Permian/Triassic (P/Tr) crisis. However, phylogenetic and character evolution in the Rhynchonellida across the P/Tr transition is poorly understood. In view of the widespread homoplasy across this order, we employ a tip-dated Bayesian analysis to reconstruct phylogenetic relationships for late Permian–Triassic rhynchonellides. The same data were also analyzed using three other methods: undated Bayesian, equal-weighting, and implied-weighting parsimony. Compared with trees generated by other methods, those constructed by tip-dating best account for the homoplasy in this group and are closer to previous assumptions on the evolution of this order. Based on the analyses of multiple trees, the major increase in lineage richness occurred in the Early and early Middle Triassic. Also, richness in the Anisian almost reached the highest level seen in the Triassic. According to fossil records, a pronounced reduction in shell size and in the development of ornamentation occurred after the P/Tr extinction, which is largely due to the loss of large and highly sculptured genera and the diversification of small-sized and weakly ornamented genera. Ancestral-state estimation of shell size and development of ornamentation, coupled with comparisons of other characters, indicate that the Early–Middle Triassic mature “small-sized taxa” may have characters displayed by juveniles of their ancestors. This suggests that for these genera, paedomorphosis was possibly a strategy to survive and diversify in the harsh environment after the P/Tr extinction.

The Order Spiriferinida spanning the latest Ordovician to Early Jurassic is a small group of brachiopods overshadowed by other taxon-rich clades during the Paleozoic. It diversified significantly after the end-Permian extinction and became one of the four major clades of Triassic brachiopods. However, the phylogeny and recovery dynamics of this clade during the Triassic still remain unknown. Here, we present a higher-level parsimony-based phylogenetic analysis of Mesozoic spiriferinids to reveal their evolutionary relationships. Ecologically related characters are analyzed to indicate the variances in ecomorphospace occupation and disparity of spiriferinids through the Permian–Triassic (P-Tr) transition. For comparison with potential competitors of the spiriferinids, the pre-extinction spiriferids are also included in the analysis. Phylogenetic trees demonstrate that about half of the Mesozoic families appeared during the Anisian, indicating the greatest phylogenetic diversification at that time. Triassic spiriferinids reoccupied a large part of the ecomorphospace released by its competitor spiriferids during the end-Permian extinction; they also fully exploited the cyrtiniform region and developed novel lifestyles. Ecomorphologic disparity of the spiriferinids dropped greatly in the Early Triassic, but it rebounded rapidly and reached the level attained by the pre-extinction spiriferids in the Late Triassic. The replacement in ecomorphospace occupation between spiriferids and spiriferinids during the P-Tr transition clearly indicates that the empty ecomorphospace released by the extinction of Permian spiriferids was one of the important drivers for the diversification of the Triassic spiriferinids. The Spiriferinida took over the empty ecomorphospace and had the opportunity to flourish.

The present study is, to our knowledge, the first self-paced reading experiment to investigate the effects of syntactic violation and semantic ambiguity on processing English modal auxiliaries. Forty undergraduate students, native speakers of English, took part in the study and read 36 target sentences, each containing a modal verb in context. Two of the most frequent English modals, can and may, were used in three distinct categories of modal expression: agent-oriented/ability, epistemic possibility, and speaker-oriented/permission. The two modal auxiliaries were manipulated such that they were either congruent or incongruent with the context, or in the case of permission felicitous or infelicitous relative to the context. We found that incongruent modal use in an agent-oriented context resulted in a reading penalty that was observed in a spillover on the segments following the modal and the lexical verb. Incongruent modal use to express epistemic possibility significantly affected reading times immediately after the modal auxiliary, and also spilt over to the following segments. Reading times in sentences expressing speaker-oriented modality were not affected by inconsistency in the use of the modal verb unmarked for formality in a formal context. The substantive and methodological implications of findings are discussed.

Plasmonic nanostructures possess broadly tunable optical properties with catalytically active surfaces. They offer new opportunities for achieving efficient solar-to-chemical energy conversion. Plasmonic metal–semiconductor heterostructures have attracted heightened interest due to their capability of generating energetic hot electrons that can be collected to facilitate chemical reactions. In this article, we present a detailed survey of recent examples of plasmonic metal–semiconductor heterostructures for hot-electron-driven photochemistry, including plasmonic metal–oxide, plasmonic metal–two-dimensional materials, and plasmonic metal–metal–organic frameworks. We conclude with a discussion on the remaining challenges in the field and an outlook regarding future opportunities for designing high-performance plasmonic metal–semiconductor heterostructures for photochemistry.

Type 2 diabetes (T2D) is a chronic disease that disproportionately affects Indigenous Australians. We have previously reported the localization of a novel T2D locus by linkage analysis to chromosome 2q24 in a large admixed Indigenous Australian pedigree (Busfield et al. (2002). American Journal of Human Genetics, 70, 349–357). Here we describe fine mapping of this region in this pedigree, with the identification of SNPs showing strong association with T2D: rs3845724 (diabetes p = 7 × 10−4), rs4668106 (diabetes p = 9 × 10−4) and rs529002 (plasma glucose p = 3 × 10−4). These associations were successfully replicated in an independent collection of Indigenous Australian T2D cases and controls. These SNPs all lie within the gene encoding ceramide synthase 6 (CERS6) and thus may regulate ceramide synthesis.

We have investigated the effects of crystal structure and size of Li[Ni1/3Co1/3Mn1/3]O2 (L333) cathodes on the performance of lithium-ion batteries. Cation ordering and particle sizes were determined as a function of annealing temperature with subsequent electrochemical performance monitored by cyclic voltammetry (CV) and charge–discharge testing. With increasing annealing temperature, L333 exhibits a greater cation ordering, which subsequently benefitted cell performance. However, higher annealing temperatures yielded larger crystal sizes, which resulted in a decrease in high rate discharge capacity and a significant capacity fade. This is attributed to an increase in lattice parameter and volume expansion during cycling, with the largest crystal sizes displaying the most significant structural changes due to the lower strain accommodation.

The poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) based ferroelectric and relaxor materials have been proved to be good electrocaloric (EC) materials. To further enhance the EC effect in ferroelectric relaxor terpolymer poly(vinylidene fluoride–trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)), composites such as polymer-polymer blends and nanocomposites filled with inorganic nanoparticles are fabricated and investigated. It is found that the addition of small amount of filler (such as P(VDF-TrFE) or nano-ZrO2) can increase terpolymer’s crystallinity and enhance its relaxor behavior through interface couplings. The increased crystallinity and enhanced relaxor behavior together result in enhanced electrocaloric effect. The results demonstrate the promise of composite approaches in tailoring and enhancing ECE in the relaxor terpolymers.