Pulsar timing arrays (PTAs) are Galactic-scale nanohertz-frequency gravitational wave (GW) detectors. Recently, several PTAs have found evidence for the presence of GWs in their datasets, but none of them have achieved a community-defined definitive (> 5σ) detection. Here, we identify limiting noise sources for PTAs and quantify their impact on sensitivity to GWs under different observing and noise modelling strategies. First, we search for intrinsic pulse jitter in a sample of 89 millisecond pulsars (MSPs) observed by the MeerKAT Pulsar Timing Array and obtain new jitter measurements for 20 MSPs. We then forecast jitter noise in pulsars for the future SKA-Mid telescope, finding that the timing precision of many of the best-timed MSPs would be dominated by jitter noise. We then consider dispersion measure variations from the interstellar medium and find that their effects are best mitigated by modelling them as a stationary Gaussian process with a power-law spectrum. Improving upon the established hasasia code for PTA sensitivity analysis, we assess the timing potential of the lower frequency UHF-band (544–1088 MHz) of MeerKAT and find a potential increase in GW background sensitivity by ≈ 8%, relative to observing at L-band. We show that this improvement relies on assumptions on the propagation through the interstellar medium, and highlight that if observing frequency-dependent propagation effects, such as scattering noise, are present, where noise is not completely correlated across observing frequency, then the improvement is significantly diminished. Using the multi-frequency receivers and sub-arraying flexibility of MeerKAT, we find that focussed, high-cadence observations of the best MSPs can enhance the sensitivity of the array for both the continuous GWs and stochastic GW background. These results highlight the role of MeerKAT and the MPTA in the context of international GW search efforts.

A seminal result of Komlós, Sárközy, and Szemerédi states that any $n$-vertex graph $G$ with minimum degree at least $(1/2+\alpha )n$ contains every $n$-vertex tree $T$ of bounded degree. Recently, Pham, Sah, Sawhney, and Simkin extended this result to show that such graphs $G$ in fact support an optimally spread distribution on copies of a given $T$, which implies, using the recent breakthroughs on the Kahn-Kalai conjecture, the robustness result that $T$ is a subgraph of sparse random subgraphs of $G$ as well. Pham, Sah, Sawhney, and Simkin construct their optimally spread distribution by following closely the original proof of the Komlós-Sárközy-Szemerédi theorem which uses the blow-up lemma and the Szemerédi regularity lemma. We give an alternative, regularity-free construction that instead uses the Komlós-Sárközy-Szemerédi theorem (which has a regularity-free proof due to Kathapurkar and Montgomery) as a black box. Our proof is based on the simple and general insight that, if $G$ has linear minimum degree, almost all constant-sized subgraphs of $G$ inherit the same minimum degree condition that $G$ has.

In a retrospective cohort of 6363 neonates admitted to three NICUs, there was no reduction in Staphylococcus aureus acquisition when comparing pre- and post-pandemic incidence rates. While additional infection prevention practices introduced during the pandemic helped prevent SARS-CoV-2 transmission, these practices may not have reduced S. aureus transmission to infants.

We explore how honesty-humility and the other HEXACO personality traits relate to citizens’ nascent ambition and their recruitment to run for office. We extend previous work on virtue-related personality traits and political recruitment in two important ways: we go beyond North America and conduct a five-country cross-national study with nationally representative samples. More importantly, going beyond individual-level differences in nascent ambition, we also address how honesty-humility predicts the likelihood of being asked to and actually running for office. Based on data from Canada, Denmark, Israel, the Netherlands, and Switzerland, we demonstrate that citizens with lower levels of honesty-humility are more likely to have considered running, to deem themselves qualified to run, to have been asked to run, and to actually have run for a political office. From a ‘virtue ethics’ perspective, this is highly concerning: low honesty-humility predisposes individuals to engage in unethical behavior and decision-making. We discuss implications for the quality of political representation.

We analyze the extent to which the prospects for economic development may relate to the environmental damages associated with economic activities. We consider an economic growth framework in which production activities generate polluting emissions which in turn negatively affect production capabilities, and publicly-funded abatement is pursued to mitigate such effects. Since the time preference is endogenously related to capital, abatement affects the size of the discount factor through its implications on capital accumulation. We show that the elasticity of environmental damages affects the optimal tax rate and thus the abatement level, which in turn determines whether the economy will end up in a stagnation or growth regime. This suggests that the cross-country heterogeneity in environmental damages may explain the different development patterns experienced by industrialized and developing economies. Our results are robust to the presence of productive public spending and two alternative forms of capital (clean and dirty capital).

This paper presents a novel robust control method for a hip-assist exoskeleton robot’s joint module, addressing dynamic performance under variable loads. The proposed approach integrates traditional PID control with robust, model-based strategies, utilizing the system’s dynamic model and a Lyapunov-based robust controller to handle uncertainties. This method not only enhances traditional PID control but also offers practical advantages in implementation. Theoretical analysis confirms the system’s uniform boundedness and ultimate boundedness. A Matlab prototype was developed for simulation, demonstrating the control scheme’s feasibility and effectiveness. Numerical simulations show that the proposed fractional-order hybrid PD (FHPD) controller significantly reduces tracking error by 58.70% compared to the traditional PID controller, 55.41% compared to the MPD controller, and 32.32% compared to ADRC, highlighting its superior tracking performance and stability.

The end of the nineteenth century saw the emergence of nationalism as the primary ideological underpinning of Australian identity, defining the broader Australian people as a culturally British, Protestant community. Such developments drew strength from key events of the early twentieth century, such as Australian federation and the Great War. Although historians have conceded that Irish Australians could adhere to the cultural tenets of Anglo-Australia, they have overlooked the extent to which Irish-Australian Catholics, especially those from the middle class, adopted Britishness as an integral part of their ethno-religious identity. Middle-class Catholic individuals, families and groups negotiated the extent of their Irishness to suit their needs within economic, social and cultural spaces dominated by Australia’s Protestant majority. This article argues that the expression of Britishness was an intrinsic part of Catholics’ middle-class ambitions, as they sought to rectify their implicit ‘otherness’ in an Australia committed to a myth of national unity on non-Irish, and non-Catholic, terms.

Although studies had suggested that monosodium glutamate (MSG) may serve as a salt substitute in processed foods, its market impact remains unclear. This study was aimed to: (1) identify MSG in ingredient lists, (2) compare sodium levels in products with and without MSG, (3) examine the association between MSG and other umami enhancers, and (4) assess manufacturers’ adherence to the Food Regulation 1985 for MSG declaration. An observational cross-sectional market survey was conducted during the Movement Control Order (June to September 2021) on 1076 processed foods from selected Malaysian hypermarkets, that were located within 10 km of the researcher’s residence to ensure accessibility amid the COVID-19 pandemic movement restrictions. Additionally, online platforms were used to supplement any missing data. Nutritional and ingredient information were collected from packaging, and foods were classified by using the FAO/WHO Food Standards CODEX Alimentarius. Over half (50.8%) of the surveyed products contained MSG. Results found that MSG-containing products had a significantly higher sodium levels (2812.2 ± 5191.4 mg/100 g) than those without (1372.2 ± 1541.4 mg/100 g) (p < 0.001). Additionally, 14.4% of MSG-free products were labelled as ‘No Added MSG’, while products with MSG were more likely to contain other umami enhancers (p < 0.001). Compliance with MSG declaration regulations was 61%. In conclusion, MSG was present in half of the surveyed products. MSG-containing products were more likely to have higher sodium content and include other flavour enhancers. Future research should analyse the actual MSG as well as sodium content and explore alternative sodium reduction strategies.

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.

Ensuring seed viability over decades is a central challenge in ex situ conservation of plant genetic resources. Standard germination tests, while effective, are destructive and fail to detect early molecular damage that precedes viability loss. RNA integrity has emerged as a promising biomarker due to the inherent vulnerability of mRNA to oxidative degradation in the dry state. In this study, we identified and validated seed-stored mRNAs in common bean (Phaseolus vulgaris), a major crop species extensively represented in global germplasm collections, and investigated transcript degradation patterns in seeds conserved for up to 30 years. Using a comparative genomics approach, we identified 107 P. vulgaris orthologs of long-lived rice mRNAs, many encoding proteins involved in RNA stabilization, oxidoreductase activity, and primary metabolism. Thirty transcripts were validated by RT-qPCR, and the integrity of nine was assessed using paired primers targeting 5′ and 3′ regions. Degradation followed a consistent 5′→3′ pattern, particularly in longer transcripts, and correlated strongly with germination power. Predictive performance varied across transcripts: PSMA4, SMP1, and TRA2 consistently showed strong correlations with viability, whereas others were less informative. The ΔΔCq metric improved resolution by detecting degradation asymmetry. Samples included a genetically diverse panel of conserved, regenerated, and artificially aged accessions, enhancing applicability to real-world genebank conditions. Artificial aging intensified degradation signatures and mirrored patterns observed in naturally aged seeds. Altogether, our results indicate transcript integrity as a molecular biomarker for seed viability, supporting the development of robust molecular tools to inform decision-making and regeneration planning in long-term germplasm conservation.

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.

We investigate the angular dynamics of a single spheroidal particle with large particle-to-fluid density ratio in simple shear flows, focusing on the influence of the fluid-inertial torque induced by slip velocity. A linear stability analysis is performed to examine how the fluid-inertial torque, viscous shear torque and particle inertia affect the various stable rotation modes, including logrolling, tumbling and aligning modes. As particle inertia increases, bistable or tristable rotation modes emerge depending on initial conditions. For prolate spheroids, three distinct stable-mode regimes are identified, i.e. logrolling, tumbling and tumbling–logrolling (TL). The presence of these modes depends on particle shape and inertia. For oblate spheroids, when the Stokes number is small, we observe monostable modes (logrolling, tumbling and aligning) and bistable modes (TL, aligning–logrolling) varying with different factors. As Stokes number increases, the tristable mode (aligning–tumbling–logrolling) of oblate spheroids appears. These results of the stability analysis further highlight the intricate and significant effect of fluid-inertial torque compared with the results in the absence of fluid-inertial torque. When we apply fluid-inertial torque to the point-particle model, we reproduce the stable rotation modes observed in particle-resolved simulations, which validates the present stability analysis.

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.