Royal Society Open Science最新文献

Two simple models-vaulting over stiff legs and rebounding over compliant legs-are employed to describe the mechanics of legged locomotion. It is agreed that compliant legs are necessary for describing running, and that leg compliance is also present during walking. Stiff legs continue to be employed to model walking under the assumption that the compliance of the leg during walking is low enough to be considered stiff. Here we study gait choice and walk-to-run transition in a biped with compliance and show that the principles underlying gait choice and transition are completely different from stiff legs. Two findings underpin our conclusions: First, at the same speed, step length and stance duration, multiple gaits that differ in the number of times the leg expands and contracts during a single stance are possible. Among them, humans and other animals choose the (normal) gait with M-shaped vertical ground reaction forces (vGRF) not just because of energy considerations but also constraints from forces. Second, the transition from walking to running occurs because of three factors: vGRF minimum at mid-stance characteristic of normal walking, synchronization of horizontal and vertical motions during single support, and velocity redirection during the double support. The insight above required an analytical approximation of the double spring-loaded pendulum (DSLIP) model describing the intricate oscillatory dynamics that relate single and double support phases. Additionally, we also examined DSLIP as a quantitative model for locomotion and conclude that DSLIP speed range is limited. However, insights gleaned from the analytical treatment of DSLIP are general and will inform the construction of more accurate models of walking.

Land systems are the nexus of many global sustainability and justice challenges. Here we present eight guiding principles (P1-8) for improved land system policies following the heuristic stages of a policy cycle. The principles are as follows: embrace recognitional justice (P1), be politically strategic (P2), consider multiple policy goals (P3), address systemic issues (P4), take an integrative scope (P5), foster co-development (P6), adopt clear and monitorable targets (P7) and integrate diagnostic and adaptive capacities (P8). We then explore how well policies align with these principles in two globally relevant cases (land-based climate mitigation and biodiversity-friendly agriculture). In both cases, we find that when policies align poorly with the principles at the agenda-setting stage, there is further misalignment at the policy formulation stage. In the instances when recognitional justice is embraced at the onset, policies subsequently integrate more diverse goals and co-development, but they insufficiently consider political strategy and struggle to handle system complexity. Nonetheless, we identify promising policy mixes that provide benefits to multiple actors, integrate multiple goals, take an integrative scope and have strong monitoring and adaptation, aligning well with multiple principles. Further investigation of these principles could reveal promising policy pathways for land systems.

Mixed molecular and isotopic signals are readily encountered in organic residue analysis (ORA) of archaeological ceramics, which can impact our ability to identify the contents/use of the vessel. One reason for these mixed signals that is rarely considered is the mixture of organic products used to coat vessels and the organic products that were later contained in the ceramic vessel. Here, we apply a multifaceted ORA approach to experimental cooking vessels that were coated with a range of organic products during post-firing treatment and then used to cook a variety of organic contents. Our results show that the visibility of the coating agent or cooking commodity varies depending on the type of extraction or analytical method applied. We show that it is important to use a combination of extraction methods (acidified methanol and solvent extraction) and that both molecular and isotopic data must be considered. For the first time, we have also shown that thermal transformation markers could reflect the post-firing coating as opposed to cooking. We call on ORA specialists to carefully consider the impact of post-firing coating before interpreting residues from archaeological ceramics and to implement a multifaceted ORA approach to aid their detection.

Canopy kelp are foundational species in coastal ecosystems and host diverse bacterial communities. Here, we test the association between bull kelp (Nereocystis luetkeana) host traits, blade-associated bacterial taxa and seawater environmental features across nine sites spanning more than 200 km in Washington state. Traits related to kelp fitness, environmental features and microbial community structure differed geographically. Kelp carbon fixation and tissue nitrogen content were greater at outer coast locales, compared with more inland locales in central and south Puget Sound. Geographic differences in carbon fixation rates, tissue nitrogen and bulb diameter were positively correlated with seawater nutrients and negatively correlated with sea surface temperature. Bacterial taxa showed differentiation among sites, and blade-associated bacterial densities were higher at the outer coast site compared with the most inland site. Yet, 11 bacterial genera were present in at least 80% of the samples; these taxa probably serve as core members of the N. luetkeana microbiome and show both positive and negative correlations with host health and environmental features. We show that there are strong interrelationships between kelp traits, seawater features and bacterial community composition with implications for the health of this highly productive foundational species in coastal ecosystems.

Vector-borne diseases (VBDs) pose significant global health threats, particularly in tropical and subtropical regions. Remote sensing (RS) and geospatial technologies offer valuable tools for monitoring environmental changes and predicting disease transmission patterns, thereby supporting proactive public health interventions. This study reviews the application of RS and geospatial methods in the prediction, monitoring and control of VBDs. A systematic approach was employed to analyse existing literature, focusing on RS platforms such as Landsat, MODIS and Sentinel-2, alongside geographical information systems and machine learning models used for predictive modelling. The review reveals that these technologies play a crucial role in identifying environmental drivers of disease dynamics, including temperature, precipitation and land-use changes. However, challenges remain in terms of data resolution, model generalizability and the integration of socio-economic factors into predictive frameworks. The integration of early warning systems and participatory surveillance is highlighted as a promising avenue for improving disease forecasting. The study emphasizes the need for enhanced data accessibility, cross-sector collaboration and the inclusion of socio-economic variables in future research to improve the scalability and accuracy of disease prediction models.

The gut microbiome influences host behaviour through the gut-brain axis (GBA), a bidirectional network of signalling pathways. Although the GBA has been well studied in humans and other mammals, its role in shaping individual behavioural variation in fish remains largely unexplored. In this study, standardized behavioural tests were conducted on 67 juvenile gilthead seabream (Sparus aurata), consisting of 30 wild and 37 reared individuals, across five major behavioural axes-boldness, aggressiveness, sociability, activity and exploration-to determine their behavioural types using linear mixed models. High levels of repeatability of behaviour and consistent behavioural types were observed along the five studied axes. Gut samples from contrasting behavioural types were analysed for diversity, composition and structure using 16S rRNA sequencing. Statistically significant correlations and differences were found between wild and reared groups in both behavioural types and gut microbiome characteristics. These findings provide novel evidence of associations between behavioural types and the gut microbiome in juvenile marine fish, suggesting that gut microbiome may play a role in modulating fish behaviour. While this relationship could involve GBA interactions, further research is needed to confirm such mechanisms. This work could have translational significance for understanding survival, recruitment and life-history evolution in the early life stages of wild fish, as well as improving conservation management of species in both aquaculture and their natural habitats.

An active approach to fault tolerance, the combined processes of fault detection, diagnosis and recovery, is essential for long-term autonomy in robots-particularly multi-robot systems and swarms. Previous efforts have primarily focused on spontaneously occurring electromechanical failures in the sensors and actuators of a minority subpopulation of robots. While the systems that enable this function are valuable, they have not yet considered that many failures arise from gradual wear and tear with continued operation, and that this may be more challenging to detect than sudden step changes in performance. This article presents the artificial antibody population dynamics (AAPD) model-an immune-inspired model for the detection and diagnosis of gradual degradation in robot swarms. The AAPD model is demonstrated to reliably detect and diagnose gradual degradation, as well as spontaneous changes in performance, among swarms of robots of varying sizes while remaining tolerant of normally behaving robots. The AAPD model is distributed, offers supervised and unsupervised configurations and demonstrates promising scalable properties. Deploying the AAPD model on a swarm of foraging robots undergoing gradual degradation enables the swarm to operate on average at between 70 and 97% of its performance in perfect conditions and is able to prevent instances of robots failing in the field during experiments in most of the cases tested.

Meta-analyses are powerful tools to synthesize the literature in several fields of study, including ecology and evolution. However, it remains uncertain whether ecologists and evolutionary biologists fully comprehend meta-analyses' findings or effectively apply them when citing these studies in their own research. Here, we first discuss key meta-analytical concepts and provide a guide to researchers in ecology and evolution on how to harness meta-analyses' insights. For instance, we clarify the meaning of effect sizes and heterogeneity to improve understanding of meta-analyses' quantitative findings. In addition, we analysed articles published in 2023 in ecology and evolution to investigate how frequently and in what context meta-analyses were cited. We found that approximately 21% of articles cited at least one meta-analysis, and that the relative number of citations of meta-analyses (0.62% of all citations analysed) was greater than the publication frequency of meta-analytical articles (0.44% of all articles). Most importantly, we found that while the direction of mean effect sizes from cited meta-analyses was often mentioned, the magnitude of effect sizes and the limitations of the data analysed were frequently overlooked. These findings underscore the need for improved citation practices of meta-analyses in ecological and evolutionary research, which our recommendations seek to promote.

The ADP-ribosyltransferase tankyrase (with two paralogues, TNKS and TNKS2) plays pivotal roles in diverse cellular processes that encompass signal transduction, including Wnt/β-catenin, Hippo and toll-like receptor (TLR) signalling, mitotic spindle assembly, glucose homeostasis and telomere maintenance, among many other functions. Tankyrase recruits its effectors (substrates and binders) via a degenerate tankyrase-binding motif (TBM) and exerts its activities by subsequent substrate ADP-ribosylation and/or scaffolding. Variants of the TBM, found in diverse proteins, engage the ankyrin repeat cluster (ARC) domains of tankyrase. Yet, whether effector recruitment to tankyrase can be regulated has remained unknown. In this study, we propose that phosphorylation at position eight of the TBM enhances the affinity of effectors for the ARC domains of tankyrase. Using isolated TBM peptides, we demonstrate that phosphorylation of serine, but not tyrosine, strengthens ARC binding by up to an order of magnitude. Interrogation of proteome-wide phosphorylation data reveals that phosphorylation at position eight in the TBM is enriched in proteins that support centrosome function/localization. Our findings suggest that TBM phosphorylation may serve as an effector-specific mechanism for tankyrase recruitment/retention, providing an additional layer of regulation to control tankyrase.

The novel coumarin derivatives (2a-2j) were synthesized via the Mannich reaction and evaluated for anti-cancer, antimicrobial and antioxidant activities. Compound (2d) exhibited the most potent cytotoxicity against MCF-7 breast cancer cells (IC₅₀ = 2.54 ± 0.12 µM), surpassing camptothecin. Compound (2b) showed strong activity against HeLa cervical cancer cells (IC₅₀ = 5.23 ± 0.12 µM), while compound (2a) demonstrated notable effects on HepG2 liver cancer cells (IC₅₀ = 8.57 ± 0.42 µM). All three compounds displayed low toxicity toward normal LLCPK1 kidney cells, with IC₅₀ values exceeding 94 µM. Antimicrobial assays revealed that compounds (2a) and (2f) effectively inhibited Bacillus subtilis, with minimum inhibitory concentration values of 25 and 75 µM, respectively. Compound (2i) showed the strongest antioxidant effect (SC₅₀ = 7.36 ± 0.18 µM), comparable to Trolox (SC₅₀ = 6.12 ± 0.15 µM). Molecular docking indicated that compound (2d) (pose 232) binds tightly to the 1T8I enzyme (ΔG = -9.92 kcal mol^-1, K_i = 0.01 µM), forming key interactions with Arg 488 and Lys 532. Molecular dynamics simulations confirmed the complex's stability in aqueous solution over 90 ns.