Traced monoidal categories model processes that can feed their outputs back to their own inputs, abstracting iteration. The category of finite-dimensional Hilbert spaces with the direct sum tensor is not traced. But surprisingly, in 2014, Bartha showed that the monoidal subcategory of isometries is traced. The same holds for coisometries, unitary maps, and contractions. This suggests the possibility of feeding outputs of quantum processes back to their own inputs, analogous to iteration. In this paper, we show that Bartha’s result is not specifically tied to Hilbert spaces, but works in any dagger additive category with Moore–Penrose pseudoinverses (a natural dagger-categorical generalization of inverses).

This article examines the institutional evolution and professionalization of the state police in Prague during the final decades of the Habsburg monarchy, arguing that the transformation of the Prague State Police between 1893 and 1910 represents a proactive effort in modern state-building. Drawing on reports from the Prague Police Directorate and the Bohemian Governor’s Office, it analyzes how recurring episodes of mass violence—specifically the unrest of the early 1890s, the riots of December 1897, and the nationalist disturbances of 1908—exposed the structural vulnerabilities of a security apparatus designed for routine policing rather than mass politics.

The article highlights a significant shift in administrative strategy: the movement away from a reliance on military intervention, which was increasingly viewed by civil authorities as a “double defeat” that undermined the legitimacy of the constitutional state. Instead, police directors such as Georg Dörfl and Karel Křikava successfully advocated for a robust, civilian-controlled force characterized by increased manpower, modernized equipment, and the establishment of a dedicated reserve for professional training. By 1910, the Prague Guard had largely expanded, reflecting a fundamental reconceptualization of urban order where protest was accepted as an unavoidable feature of political life to be contained by professional civilian forces rather than crushed by the army.

We study the classical relationship between a firm’s investment and q, for which an unobserved persistent shock is an important factor in the investment decision. In our setting, besides the potential measurement problem of q, controlling for the unobserved shock becomes a new challenge. We develop an estimation method that addresses both econometric issues given timing and information set assumptions. Using 16,256 unique public firms in the United States from 1975 to 2021, we find that q remains a significant factor of investment even after controlling for the unobserved shock and measurement error.

Prenatally diagnosed cardiac mass in a newborn caused cardiac tamponade. Cardiac MRI and histopathology confirmed a rare right ventricular mesenchymal hamartoma, previously reported only in the left ventricle.

An automorphism of the free group $F_n$ is called pure symmetric if it sends each generator to a conjugate of itself. The group $\mathrm {PSAut}_n$ of all pure symmetric automorphisms and its quotient $\mathrm {PSOut}_n$ by the group of inner automorphisms are called the McCool groups. In this article, we prove that every BNSR-invariant $\Sigma ^m$ of a McCool group is either dense or empty in the character sphere, and we characterize precisely when each situation occurs. Our techniques involve understanding higher generation properties of abelian subgroups of McCool groups, coming from the McCullough–Miller space. We also investigate further properties of the second invariant $\Sigma ^2$ for McCool groups using a general criterion due to Meinert for a character to lie in $\Sigma ^2$.

While the late Llandovery brachiopod faunas of South China are well documented, they are known almost exclusively from shallow-water settings. Here, we present a detailed study of a brachiopod fauna from the Ningqiang Formation (early to middle Telychian) at the Bifengguan section in Sichuan Province, South China. Quantitative analyses, including non-metric multidimensional scaling (NMDS) and network analysis, reveal three successive brachiopod associations. Significantly, the basal Aegiria–Epitomyonia association was characterized by the abundance of the deep-water indicator Epitomyonia. This represents the first definitive record of a deep-water (BA4) community within the Telychian Xiushan Fauna, which was previously thought to be restricted to shallower environments. This basal association is succeeded by the Aegiria–Megaspinochonetes and Fardenia–Striispirifer associations, and this complete succession indicates a shallowing-upward environmental trend from a BA4 to an upper BA3 setting. We interpret this shallowing trend as a response to regional uplift. The initial existence of this deep-water association was likely facilitated by the unique paleogeographical position of the locality, which likely provided a stable habitat for this deep-water community. This study expands the known ecological range of the Xiushan Fauna and underscores the critical role of local paleogeography in shaping benthic community structures during the early Silurian.

This commentary is part of a series of responses to Michele Goodwin’s 2025 LSA presidential address.

In this editorial, three technological laggards reflect on the potential promises and pitfalls of artificial intelligence in psychiatry, as explored in recent BJPsych publications. We argue that the rapid changes driven by artificial intelligence are revealing underlying vulnerabilities within our profession. More importantly, we believe these shifts pose a fundamental challenge to our specialty: can we, as psychiatrists, evolve beyond mere intelligence to practice with genuine wisdom?

Jabłonowski [‘On biquandle-based invariant of immersed surface-links, Yoshikawa oriented fifth move, and ribbon 2-knots’, Preprint, 2025, arXiv:2505.14724] proved that the knot quandles of Suciu’s n-knots, which share isomorphic knot groups, are mutually nonisomorphic, and Yasuda [‘Knot quandles distinguish Suciu’s ribbon knots’, Preprint, 2025, arXiv:2508.15129] later gave a different proof. We present yet another proof of this result by analysing the conjugacy classes of certain automorphisms of the free group of rank two.

In unstructured environments, Delta robots face challenges in achieving high vision-guided grasping precision due to dynamic lighting conditions and workpiece diversity. This paper designs an integrated solution that combines RGB-D multimodal learning with an enhanced Mask R-CNN framework. Initially, a dual-stream ResNet50-FPN backbone network is designed to achieve cross-modal adaptive alignment via hierarchical feature fusion. Subsequently, a depth-guided attention module is incorporated to bolster robustness against material ambiguity and reflective interference. Moreover, a dynamic depth estimation algorithm is employed to significantly improve target localization accuracy and stability. Finally, real-time trajectory tracking is realized by integrating PD control with Jacobian mapping. Experimental results validate the efficacy of the proposed method, offering an efficient and reliable approach for industrial robotic applications.