We define a new class of plane billiards – the “pensive billiard” – in which the billiard ball travels along the boundary for some distance depending on the incidence angle before reflecting, while preserving the billiard rule of equality of the angles of incidence and reflection. This generalizes so-called “puck billiards” proposed by M. Bialy, as well as a “vortex billiard,” that is, the motion of a point vortex dipole in two-dimensional hydrodynamics on domains with boundary. We prove the variational origin and invariance of a symplectic structure for pensive billiards, as well as study their properties including conditions for a twist map, the existence of periodic orbits, etc. We also demonstrate the appearance of both the golden and silver ratios in the corresponding hydrodynamical vortex setting. Finally, we introduce and describe basic properties of pensive outer billiards.

We establish a polynomial ergodic theorem for actions of the affine group of a countable field K. As an application, we deduce—via a variant of Furstenberg’s correspondence principle—that for fields of characteristic zero, any ‘large’ set $E\subset K$ contains ‘many’ patterns of the form $\{p(u)+v,uv\}$, for every non-constant polynomial $p(x)\in K[x]$. Our methods are flexible enough that they allow us to recover analogous density results in the setting of finite fields and, with the aid of a finitistic variant of Bergelson’s ‘colouring trick’, show that for $r\in \mathbb N$ fixed, any r-colouring of a large enough finite field will contain monochromatic patterns of the form $\{u,p(u)+v,uv\}$. In a different direction, we obtain a double ergodic theorem for actions of the affine group of a countable field. An adaptation of the argument for affine actions of finite fields leads to a generalization of a theorem of Shkredov. Finally, to highlight the utility of the aforementioned finitistic ‘colouring trick’, we provide a conditional, elementary generalization of Green and Sanders’ $\{u,v,u+v,uv\}$ theorem.

Skilled and impaired language users can fail to understand sentences with noncanonical thematic role ordering. To advance understanding of the cause of the difficulty, we compared noncanonically ordered, object-experiencer-verb (OE) sentences to canonical agentive sentences in otherwise comparable syntactic structures. However, the field has neglected to consider that OE thematic roles may be altered by the comprehender’s interpretation; the aim of the investigation reported here was to address this research gap. We collected participants’ thematic role interpretations for sentences while measuring incremental processing speed as they read the sentences in a self-paced reading paradigm. Fluent English speakers rated the intent of the subjects of OE and agentive active sentences and of the objects of OE and agentive passive sentences. Consistently high ratings of intent identified a cluster containing agentives and an OE eventive subtype with an agent. In contrast, a spread of ratings in a second cluster suggested labile interpretation for a second OE subtype. Splitting the labile group at its active and passive mean, we compared reading time of OE and agentive sentences with a higher-intent, agent interpretation with OE sentences with a low-intent causer/theme interpretation. Whether active or passive, canonicity as determined by the relative prominence ordering of the rated role compared to the necessary OE experiencer or agentive theme, accounted for reading speed at the verb, second noun, and prepositional phrase. We propose that the results support an agent > experiencer > (causer)/theme thematic role hierarchy, suggesting refinements to event structure theory and little v/CAUS morphology.

The global use of antimicrobial chemicals drastically increased during and after the COVID-19 pandemic owing to heightened awareness of personal and surface hygiene needs. Disinfectants, especially chlorine-based disinfectants (CBDs), were extensively used for surface and equipment decontamination in the domestic, industrial, veterinary and healthcare sectors during the heights of the pandemic. The increased use of disinfectants has resulted in their increased discharge into municipal wastewater systems and surface waters. Our Perspective article considers the One Health challenges associated with the increased discharge of disinfectants into wastewater. One Health is a collaborative approach that ensures the well-being of people, animals and the environment. Wastewater is a common endpoint to the many interactions between people, animals and their environment. The potential One Health challenges and knowledge gaps associated with the constant discharge of low but sublethal concentrations of CBDs into wastewater are discussed. The data gaps point to the risks associated with the unregulated use of CBDs and need for their judicial use.

This study investigates the gut microbiota of newly emerged adult females and males of five economically important Anastrepha species (Tephritidae) – A. ludens, A. obliqua, A. serpentina, A. striata, and A. fraterculus – by analyzing 16S rRNA amplicon sequences from 36 samples collected from ecologically relevant fruit hosts and locations in Mexico. We chose to concentrate only on newly emerged adults to identify bacteria that females could potentially transmit vertically to progeny via oviposition, a topic that remains poorly studied. Results revealed that Proteobacteria dominated the microbiota in all species, but substantial variation was observed in genus-level composition. Differentially abundant genera included Enterobacter, Gluconobacter, Tatumella, Providencia, Ochrobactrum, Siccibacter, Sphingobacterium, and Sphingobium. Significant differences in alpha diversity were observed between species, particularly between A. obliqua and A. striata, and between A. obliqua and A. serpentina based on the Shannon index. Anastrepha ludens, A. obliqua, and A. striata males exhibited higher species richness than females, although these differences were not statistically significant within individual species likely due to limited sample size. Interestingly, across all species, significant differences in microbiota composition were observed between males and females. Our findings suggest that morphological, physiological (i.e., metamorphosis) and ecological factors, such as possible gut structural differences and host fruit preferences, may influence the composition of the gut microbiota, potentially affecting the ecological adaptability and pest behavior of these flies.

We introduce a new family of coalescent mean-field interacting particle systems by producing a pinning property that acts over a chosen sequence of multiple time segments. Throughout their evolution, these stochastic particles converge in time (i.e. get pinned) to their random ensemble average at the termination point of any one of the given time segments, only to burst back into life and repeat the underlying principle of convergence in each of the successive time segments, until they are fully exhausted. Although the architecture is represented by a system of piecewise stochastic differential equations, we prove that the conditions generating the pinning property enable every particle to preserve their continuity over their entire lifetime almost surely. As the number of particles in the system increases asymptotically, the system decouples into mutually independent diffusions, which, albeit displaying progressively uncorrelated behaviour, still close in on, and recouple at, a deterministic value at each termination point. Finally, we provide additional analytics including a universality statement for our framework, a study of what we call adjourned coalescent mean-field interacting particles, a set of results on commutativity of double limits, and a proposal of what we call covariance waves.

In this study, we investigate the chemical enrichment and structural evolution of the isolated elliptical relic galaxy Mrk1216 through X-ray observations. As a red-nugget relic, Mrk1216 provides a rare window into the early Universe, owing to its minimal interaction with the surrounding environment. Using data from the XMM-Newton telescope, we model the X-ray emission of its interstellar medium to derive radial temperature and abundance profiles. We find that the central region exhibits an elevated [Mg/Fe] ratio compared to typical early-type galaxies, consistent with a brief but intense star formation episode during its early assembly – a hallmark of relic systems. The nearly flat SNIa ratio profile ($R_{Ia} \sim 0.17$) extending to $\sim0.42R_{500}$ supports an early-enrichment scenario. These results highlight the importance of relic galaxies as benchmarks for studying early galaxy evolution and chemical enrichment. Future high-resolution missions and more advanced theoretical models incorporating more realistic initial mass functions are needed to fully assess their implications.

Field experiments were conducted near Beresford and South Shore, South Dakota, in 2023 and 2024, to determine weed control and soybean yield with 2,4-D and glufosinate applied individually, together, and sequentially. Herbicides were sequentially applied 12 d after an initial application. 2,4-D + glufosinate additively controlled and reduced the height of all tested weed species. Sequential applications resulted in greater control of common lambsquarters, waterhemp, redroot pigweed, and velvetleaf compared with 2,4-D or glufosinate applied alone, or 2,4-D + glufosinate applied in a mixture. The order in which herbicides were sequentially applied did not influence broadleaf weed control. Yellow foxtail control was greater with sequential applications of glufosinate. Soybean yield at Beresford was similar across all treatments. Yields were generally greater at South Shore with sequential herbicide applications when glufosinate was initially applied. The experiment results suggest that weed control and soybean yield are greater with 2,4-D + glufosinate or sequential application treatments that include 2,4-D and glufosinate.

In this article, I center substantial improvement in subnational democracy in the U.S. states as an object of inquiry and seek to explain it. I theorize that strong unions, high Democratic Party control of state government, an especially liberal Democratic Party, a large population of people of color, and a particularly liberal public mood may each contribute to substantial improvement in democratic quality. Using Coincidence Analysis (CNA), a configurational causal method, I assess the evidence for my hypotheses. The CNA identifies three alternative paths to substantial improvement in electoral democracy in the states. The results of my analysis highlight that substantial improvement in electoral democracy is the product of political struggle centrally involving unions and the Democratic Party.

Few village-born social movements have influenced international relations as much as the campaign against Myitsone Dam in Burma (Myanmar). This village-born resistance led in 2011 to the suspension of a major Burmese and Chinese infrastructure project. This suspension became a symbol of democratization in Burma and a much-discussed setback of Chinese development-investment abroad. However, research literature on the Myitsone Dam has tended to conflate the local rural resistance with the broader ethnic Kachin and Burmese anti-dam movements. In contrast, this study focuses specifically on the local villages directly affected by the project, exploring their diverse stories and responses to the mega-project. Combining diverse published sources with ethnographic fieldwork and interviews done since 2010, it tells a story of repression, resistance, social divisions, and complex relations with outsiders. This is a two-part article series. This article here – Part 1 – examines what occurred before the mega-project’s suspension. It tells the Myitsone Dam’s rural story from its earliest days until the mega-project’s fall: from 2002 to 2011. This story begins with the unexpected arrival of Japanese visitors and traces the village struggles up to the project’s dramatic downfall.

Existing guidelines on overviews of reviews and umbrella reviews recommend an assessment of the certainty of evidence, but provide limited guidance on ‘how to’ apply the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to such a complex evidence synthesis. We share our experience of developing a ‘general principles’ approach to applying GRADE to a complex overview of reviews. The approach was developed in an iterative and exploratory manner during the planning and conduct of an overview of reviews of a novel molecular imaging technique for the staging of prostate cancer, involving a formal review by a group of 11 methodologists/health services researchers. This approach was developed during the evidence synthesis process, piloted, and then applied to our ongoing overview of reviews. A ‘general principles’ approach of applying the domains of GRADE to an overview of reviews and arriving at an overall summary judgement for each outcome is presented. Our approach details additional factors to consider, including addressing both the primary study risk of bias as assessed by the included reviews and the risk of bias of the systematic reviews themselves, as well as the statistical heterogeneity observed in meta-analyses conducted within the included reviews. Our approach distilled key principles from the relevant GRADE guidelines and allowed us to apply GRADE to a complex body of evidence in a consistent and transparent way. The approach taken and the methods used to develop our approach may inform researchers working on overviews of reviews, umbrella reviews, or future methodological guidelines.

We report detection and analysis of the largest ever low-frequency sample of Crab giant pulses (GPs) detected in frequency band 200–231.25 MHz. In total, about $\sim$95 000 GPs were detected, which, to our knowledge is the largest low-frequency sample of Crab GPs presented in the literature. The observations were performed between 2024-12-14 and 2025-03-31 with the Engineering Development Array 2, a prototype station of the low-frequency Square Kilometre Array telescope. The fluence distribution of GPs in the entire sample is very well characterised with a single power law N(F) $\propto$ F$^\alpha$, where $\alpha =-3.17\pm0.02$ for all GPs, and $\alpha_{MP} =$ $-3.13\pm0.02$ and $\alpha_{IP} =-3.59\pm0.06$ for GPs at the phases of the main pulse and low-frequency interpulse, respectively. We do not observe flattening of the fluence distribution at the higher fluences. Although the index of the power law fluence distribution remained approximately constant over the observing period, the normalisation of the distribution was strongly anti-correlated (coefficient $\approx -0.9$) with the scatter broadening time. The timescale ($\sim$ weeks) of these variations indicates that intrinsic GP emission was modulated by the refractive scintillation as the signals propagated through the Crab Nebula and ISM. As a result, the measured fluence distribution was augmented for lower ($\tau \approx$ 2 ms) and diminished for higher ($\tau \approx$ 5 ms) scatter broadening time $\tau$ causing the GP detection rate to vary between 3 000 and 100 per hour, respectively (the correlation coefficient $\approx -0.9$). Furthermore, for the first time at low frequencies we observe indications of positive correlation (correlation coefficient $\approx$0.7) between the scatter broadening time ($\tau$) and dispersion measure. Our modelling favours the screen size $\sim10^{-5}$ pc with mean electron density $\sim 400\textit{e}^{-}$cm$^{-3}$ located within 100 pc from the pulsar (Crab Nebula or Perseus arm of the Milky Way galaxy). The observed frequency scaling of the scattering broadening time $\beta \approx -3.6\pm0.1$ (where $\tau \propto \nu^{\beta}$) is in agreement with the previous measurements. The observed maximum spectral luminosities $\sim 10^{25}$ erg/Hz/s approach those of the weakest pulses from some repeating fast radio bursts (FRBs). However, the distribution of pulse arrival times is consistent with a purely random Poisson process, and we do not find evidence of clustering. Overall, our results agree with the current views that GPs from extra-galactic Crab-like pulsars can be responsible for some very weak repeating FRBs, but cannot explain the entire FRB population. Finally, these results demonstrate an enormous transient science potential of individual SKA-Low stations, which can be unlocked by milli-second all-sky imaging.

Medication Use Evaluations (MUEs) are structured quality improvement tools used to optimize medication use within healthcare systems. MUEs can explore safety concerns, high costs, or inappropriate use associated with any medication, among other factors. This can offer a valuable opportunity for Antimicrobial Stewardship Programs (ASPs) to promote stewardship goals, which often overlap with these concerns for specific antimicrobials. MUEs can also provide an avenue to promote interdisciplinary collaboration with targeted groups relevant to the ASP’s goals as well as an opportunity to give trainees ownership of system-facing stewardship projects. Stewardship pharmacists may often have experience with leading this process as part of their training, but MUEs represent a gap in training for physicians. Here we provide guidance on how stewardship physicians can engage in the MUE process, from identifying relevant topics to interpreting findings and supporting implementation efforts, allowing them to contribute effectively even without prior MUE experience.