In this article, we study the pressure at infinity of potentials defined over countable Markov shifts. We establish an upper semi-continuity result concerning the limiting behaviour of the pressure of invariant probability measures, where the escape of mass is controlled by the pressure at infinity. As a consequence, we establish criteria for the existence of equilibrium states and maximizing measures for uniformly continuous potentials. Additionally, we study the pressure at infinity of suspension flows defined over countable Markov shifts and prove an upper semi-continuity result for the pressure map.

This article considers British early nineteenth century attempts to reclaim Sagar Island, at the southwestern extremity of the Bengal delta, by clearing the island of jungle and settling and cultivating it—a project led first by colonial authorities at Calcutta and then by a joint-stock company established for the purpose, the Sagar Island Society. It considers the motivations behind the reclamation attempts, what they involved, and why they failed. The consequences – economic, human, and ecological—of the reclamation attempts are examined. The article reconstructs the almost entirely unknown history of events on Sagar Island from 1810 to 1833 through extensive new archival research and the study of rarely consulted publications from the period, before exploring their implications. In doing so, it sheds new light on the nature of British colonial capitalism and the environmental impact of British colonial interventions in South Asia, contributing to our understanding of the economic and environmental history of colonial Bengal and of the wider British imperial world. The article contends that events on Sagar Island offer a cautionary lesson about public and private initiatives to extend the frontiers of revenue extraction, and about the hubris of human efforts to ‘improve’ natural environments through large-scale projects of transformation. New insights are offered into the collusion between government and capital in British Bengal between the East India Company charter acts of 1813 and 1833, and into the colonial and capitalist origins of the Anthropocene.

Survivorship among individuals with CHD has expanded, bringing more pregnancies into routine care. In this issue, a single-centre retrospective case–control study (162 CHD deliveries vs 321 controls) reports higher composite maternal cardiac events (8.6 vs 3.4%; risk ratio 2.5, 95% CI 1.2–5.4), greater use of operative or assisted delivery, and an approximately doubled length of stay. Modified WHO class correlates with length of stay but not with discrete cardiac events; maternal age independently predicts cardiac events; rates of pre-eclampsia are lower in CHD. These findings support first-trimester cardio-obstetric triage, standardised delivery bundles, and capacity planning that uses risk class to anticipate monitoring needs, with routine 6–12-week postpartum review. Limitations include selection, era differences, and modest sample size. Overall, anticipatory planning and disciplined intrapartum decision-making remain key to safe, resource-aware care for pregnant women with CHD.

This study presents a comprehensive systematic analysis of a cold-water brachiopod fauna from the upper Cisuralian (lower Permian) Kharnuden Formation, exposed at the Hovsugol section in southeastern Mongolia. Taxonomic investigation identifies 40 species belonging to 28 genera, including three newly described taxa: Paramarginifera pentagona n. sp., Linoproductus planiconvexus n. sp., and Jilinmartinia hovsugolensis n. sp. Biostratigraphic evidence tentatively indicates a Kungurian age, with possible extension down into the Artinskian. The assemblage likely originated along the southern margin of the Siberian Craton, within the Paleo-Asian Ocean (PAO). The fauna exhibits strong biogeographic affinities with contemporaneous faunas from the Beishan orogenic belt (northwestern China), Inner Mongolia, South Primorye (Russia), and selected Japanese terranes, yet differs significantly from assemblages in Transbaikal and central-northeastern Mongolia. These contrasts support the presence of the Sino-Mongolian Seaway—a transitional marine corridor within the closing PAO. The fauna is characterized by elements of the northern Boreal biogeographic realm, with a dominance of cold-adapted and endemic taxa and a complete absence of paleotropical elements. Associated paleoecological indicators suggest the influence of cool-temperate conditions at a relatively high-latitude paleogeographic position as well as geographic isolation. This paleobiogeographic pattern sheds light on the responses of Permian marine ecosystems to plate convergence, latitudinal climate gradients, and oceanic current reorganization during the final stages of the PAO closure.

UUID: http://zoobank.org/67bcfb84-2b08-46a7-a117-d86b79837c75

A computable topological presentation of a space is given by an effective list of a countable basis of non-empty open sets so that the intersection of the basic sets is uniformly effectively enumerable. We show that every countably-based $T_0$-space has a computable topological presentation, and that, conversely, every (formal) computable topological presentation represents some Polish space. In the compact case, we give a computable uniform list of computable topological presentations such that every compact Polish space is represented by exactly one presentation from the list. Note that none of these results assume that the Polish (or $T_0$) spaces are effective. Quite surprisingly, the effectively compact topological presentations turn out to be rather well behaved. Not only do such presentations allow one to construct a $\Delta ^0_2$ (complete) metric compatible with the topology, but also, under a mild extra condition, they can be turned into a computably compact Polish presentation of the space.

With the rapid development of artificial intelligence technology, robotics, as its core branch, has attracted extensive attention from researchers. This paper designs and develops a robotic arm learning system based on multi-source sensor information fusion, which investigates the autonomous learning capability of robotic arms by closely integrating deep reinforcement learning (DRL) as the core framework for skill acquisition. By incorporating imitation learning as a source of expert prior and leveraging DRL’s intrinsic ability for policy optimization through environmental exploration, the proposed system achieves both rapid learning and robust generalization. Specifically, we introduce the gradient penalty mechanism from Wasserstein generative adversarial networks (WGANs), a technique that improves the stability of adversarial training by penalizing gradients that deviate from a specified norm. This mechanism is incorporated into the soft actor-critic (SAC) algorithm, a widely used off-policy DRL method known for its sample efficiency and robust performance in continuous control tasks. The resulting SAC-GP (SAC-gradient penalty) algorithm benefits from both SAC’s stable policy learning and WGAN’s improved training regularization, leading to superior convergence speed and system stability. Furthermore, this paper proposes a hybrid learning framework by combining generative adversarial imitation learning (GAIL) with SAC-GP, enabling the agent to benefit from both demonstration-based policy initialization and continuous self-improvement via reinforcement learning. Finally, a door-opening experiment is designed to verify the learning and execution capabilities of the system in both virtual and real environments. Experimental results demonstrate that the proposed learning system possesses excellent learning and motion execution abilities in practical applications. This achievement not only provides new insights for research in robot learning but also lays a solid foundation for the future development of robotic technology.