The Dehn quandle of a closed orientable surface is the set of isotopy classes of nonseparating simple closed curves with a natural quandle structure arising from Dehn twists. In this paper, we consider the finiteness of some canonical quotients of these quandles. For a surface of positive genus, we give a precise description of the 2-quandle of its Dehn quandle. Further, with some exceptions for genus more than 2, we determine all values of n for which the n-quandle of its Dehn quandle is finite. The result can be thought of as the Dehn quandle analogue of a similar result of Hoste and Shanahan for link quandles [‘Links with finite n-quandles’, Algebr. Geom. Topol. 17(5) (2017), 2807–2823]. We also compute the size of the smallest nontrivial quandle quotient of the Dehn quandle of a surface. Along the way, we prove that the involutory quotient of an Artin quandle is precisely the corresponding Coxeter quandle, and also determine the smallest nontrivial quotient of a braid quandle.

The history of mining education in late Qing China has received relatively little attention in scholarly literature. Through the lens of institutionalising global mining knowledge, this article addresses the following questions: How did the demand for expertise within the framework of mining bureaucracy evolve under the impact of Western imperialism? How did mining education enter scholarly discourse and become eventually institutionalised in the late Qing China? Drawing on evidence from the collections of Sheng Xuanhuai's archive series, it investigates two previously overlooked ‘failures’ of Sheng's mining-related enterprises, namely his earliest mining practices in Hubei in the 1870s and his proposal for establishing a mining school in Shandong in 1888–89. It then reconnects these efforts with the histories of Western learning, late Qing mining bureaucracy, the monetary crisis of that era, and the global recruitment of engineers despite a pronounced distrust of foreign expertise. It argues that these seemingly discrete efforts or ‘failures’ in fact paved the way for initiating China's first engineering university as well as other mining colleges in around 1895 and eventually led to the rise of engineering education before the entire educational system was transformed in China.

This article aims at raising awareness about the intersection of populism and bioethics. It argues that illiberal forms of populism may have negative consequences on the evolution of bioethics as a discipline and on its practical objectives. It identifies at least seven potential negative effects: (1) The rise of populist leaders fosters “epistemological populism,” devaluing the expert and scientific perspectives on which bioethics is usually based, potentially steering policies away from evidence-based foundations. (2) The impact of “moral populism” is evident in legislative prioritization of the “morality of common people,” often solicited through popular consultations on issues like abortion, drug legalization, or LGBT issues. (3) Populist distrust in autonomous governmental agencies and advisory bodies, including national bioethics commissions, can compromise expert advice, challenging both their authority and decisions. (4) Populists may erode transparency by undermining institutions responsible for it, hindering access to vital information for bioethical research. (5) “Medical populism” creates adversarial dynamics, prompting politicians to make simplistic healthcare policy decisions based on political rather than informed criteria, adversely affecting vulnerable populations. (6) Radical-right populist parties’ “welfare chauvinism” may shape healthcare policies, impacting service access and resource allocation, disproportionately affecting vulnerable groups such as migrants, but indirectly affecting the rest of the population. (7) Nationalist sentiments associated with populism may obstruct international collaborations, posing challenges for global bioethics that seeks to address ethical concerns beyond national borders. In summary, these dynamics raise significant bioethical concerns encompassing evidence-based decision-making, transparency, healthcare equity, and global collaboration. How bioethicists may respond to these challenges is discussed.

This study employs annual reports, time-series statistics, and internal training records of the colonial-era Korean Government Railways (KGR) to conduct a quantitative analysis of its labour management practices. It addresses the colonial characteristics associated with Japanese techno-imperialism beyond ethnic discrimination, revealing a dual-pronged labour strategy that adopted a Japanese government employee system to manage middle- and upper-level personnel and directly recruited on-site workers for the lower echelons. This deviates from the low rates of local employment in Western colonies, particularly self-governing British territories or integrated French territories. In contrast, KGR's employment practices demonstrated economic and ethnic inequalities. It predominantly made Koreans on-site labourers, whereas Japanese not only held similar roles, but also occupied upper- and middle-management positions. Worker mobility, particularly among Japanese employees, grew following the outbreak of war between Japan and the USA, leading to the mass external recruitment of Koreans and the expansion of internal education to alleviate labour shortages. Nevertheless, preferential treatment toward Japanese individuals, which had been in relative decline for promotion, wages, and admission rates to training schools, ultimately persisted. Understanding KGR's employment structure shows how colonisation mediated Korea's modernisation and imposed technical limitations on the management of local labour. National technological decolonisation thus required Koreans to further introduce external technologies after the end of Japan's imperial reign.

Daniel Laqua's Activism across Borders since 1870 is an impressive contribution to scholarly research on transnational activism. It provides a detailed and innovative study of the connections but also the divisions between individuals, groups, and organizations. Laqua's approach and analysis interrogate the connectedness, transience, ambivalence, and marginality of transnational activism. He explores the complex relationship of campaigners, campaigns, and causes that crossed national boundaries, building a rich analysis of these interactions.

This contribution engages with Activism across Borders with a particular emphasis on women, workers, and women workers. This perspective offers an analysis at the intersection of women's history and labour history. Among the themes considered are: campaigns that forged partnerships and amplified voices; women's transnational activism and national borders; and the divisions and differences among activists campaigning to improve working conditions.

The aim of this paper is to inform a sociological jurisprudence of the implied duty in the contract of employment of mutual trust and confidence. Present analyses of the emerging term have been doctrinal in nature. Such scholarship contributes a normative internal perspective to what can be understood as the jurisprudential project of guarding and maintaining law as a practice of regulation. This paper seeks to generate knowledge that will allow for an extension of the jurisprudential analysis to take into account how mutual trust and confidence may manifest in contemporary conditions of work. This is achieved by, first, presenting original sociological data of the employment relation in a work context likely to demonstrate practices that resonate with features of mutual trust and confidence – that of early-stage digital technology startups – and, secondly, contrasting this empirical account with doctrinal conceptions of the term. Findings unsettle the dominant jurisprudential account of mutual trust and confidence as positively contributing to the social goal of labour law as operating to counter the power of capital.

We propose a new approach to the semiparametric analysis of panel data binary choice models with fixed effects and dynamics (lagged dependent variables). The model under consideration has the same random utility framework as in Honoré and Kyriazidou (2000, Econometrica 68, 839–874). We demonstrate that, with additional serial dependence conditions on the process of deterministic utility and tail restrictions on the error distribution, the (point) identification of the model can proceed in two steps, and requires matching only the value of an index function of explanatory variables over time, rather than the value of each explanatory variable. Our identification method motivates an easily implementable, two-step maximum score (2SMS) procedure – producing estimators whose rates of convergence, in contrast to Honoré and Kyriazidou’s (2000, Econometrica 68, 839–874) methods, are independent of the model dimension. We then analyze the asymptotic properties of the 2SMS procedure and propose bootstrap-based distributional approximations for inference. Evidence from Monte Carlo simulations indicates that our procedure performs satisfactorily in finite samples.

We construct a new family of quintic non-Pólya fields with large Pólya groups. We show that the Pólya number of such a field never exceeds five times the size of its Pólya group. Finally, we show that these non-Pólya fields are nonmonogenic of field index one.

During an ecological study with a near-endangered anuran in Brazil, the Schmidt’s Spinythumb frog, Crossodactylus schmidti Gallardo, 1961, we were given a chance to analyze the gastrointestinal tract of a few individuals for parasites. In this paper, we describe a new species of an allocreadiid trematode of the genus Creptotrema Travassos, Artigas & Pereira, 1928, which possesses a unique trait among allocreadiids (i.e., a bivalve shell-like muscular structure at the opening of the ventral sucker); the new species represents the fourth species of allocreadiid trematode parasitizing amphibians. Besides, the new species is distinguished from other congeners by the combination of characters such as the body size, ventral sucker size, cirrus-sac size, and by having small eggs. DNA sequences through the 28S rDNA and COI mtDNA further corroborated the distinction of the new species. Phylogenetic analyses placed the newly generated sequences in a monophyletic clade together with all other sequenced species of Creptotrema. Genetic divergences between the new species and other Creptotrema spp. varied from 2.0 to 4.2% for 28S rDNA, and 15.1 to 16.8% for COI mtDNA, providing robust validation for the recognition of the new species. Even though allocreadiids are mainly parasites of freshwater fishes, our results confirm anurans as hosts of trematodes of this family. Additionally, we propose the reallocation of Auriculostoma ocloya Liquin, Gilardoni, Cremonte, Saravia, Cristóbal & Davies, 2022 to the genus Creptotrema. This study increases the known diversity of allocreadiids and contributes to our understanding of their evolutionary relationships, host–parasite relationships, and biogeographic history.

This essay engages with Daniel Laqua's book Activism across Borders since 1870: Causes, Campaigns and Conflicts in and beyond Europe (London, 2023) from the perspective of a historian of both humanitarianism and youth. This short reflection therefore focuses primarily on the book's engagement with the topic of humanitarianism, before discussing an understated, albeit important, cross-cutting theme of the book: the significance of youth in transnational activism. It highlights a number of features of Laqua's book, for instance the merits of adopting a broad chronological approach. At the same time, the essay also uses the space to present a number of reflections on activism, from questions about the generational appeal of particular causes to the way in which particular figures might spark activism. It ends with some thoughts about the source base used to write such histories of activism.

A positive even number is said to be a Maillet number if it can be written as the difference between two primes, and a Kronecker number if it can be written in infinitely many ways as the difference between two primes. It is believed that all even numbers are Kronecker numbers. We study the division and multiplication of Kronecker numbers and show that these numbers are rather abundant. We prove that there is a computable constant k and a set D consisting of at most 720 computable Maillet numbers such that, for any integer n, $kn$ can be expressed as a product of a Kronecker number and a Maillet number in D. We also prove that every positive rational number can be written as a ratio of two Kronecker numbers.

Although many return migrants had planned to go back to their country of origin, other return migrants who had originally planned to pursue the immigrant dream––the idea that one can have a better life by migrating—eventually change their mind and return to their society of origin. Just as the identity of individuals must adjust to the loss of a relationship, job, or membership of a group, many formerly aspiring immigrants give up on immigrating. I analyze data from oral history interviews and social media narratives of 121 Chinese ex-immigrants from 16 different countries. I show how disappointments, the language barrier, cultural alienation, racial-ethnic discrimination, intersectional-gender issues, barriers to upward socioeconomic mobility, and/or restrictive immigration policies interact with each other to constitute ex-immigrant subjectivity. This article highlights why immigration is a far less certain process than many perceive it to be, contributing to the broader sociological literature on how in different and similar ways processes of abandoning important social endeavors, like a romantic partnership, political party, or religious faith, transform subjectivities and social identities in other domains of social life.

Between 1881 and 1914, Hungarian governments established at least 36 agricultural colonies in today’s territory of Romania (nine new villages and 25 neighborhoods attached to existing ones). After 1894, a separate government fund was created for land purchases and the venture was entrusted to a Department of Colonization within the Ministry of Agriculture. This article gives an archival-based account of the political, financial, agricultural, and logistical aspects of the settlement program and compares it with its better-researched Prussian model. Investigating it as a series of interactions between settlers, the dedicated government agency, local potentates, and the surrounding population, it identifies structural impediments to the endeavor. Although there was a broad unity across political parties behind the idea of conquering new territories for the ethnic nation, the settlement program rested on a fragile consensus within the elite. Its expansion after 1900 was mainly due to Minister Ignác Darányi, whereas the steps of other high officials give nuances to Hungarian nationalities policies. When Prime Minister István Tisza dropped the program on the eve of the First World War, it was already in a state of hibernation because the governing party had realized that the settlers posed a political liability for them.

We study a variant of the color-avoiding percolation model introduced by Krause et al., namely we investigate the color-avoiding bond percolation setup on (not necessarily properly) edge-colored Erdős–Rényi random graphs. We say that two vertices are color-avoiding connected in an edge-colored graph if, after the removal of the edges of any color, they are in the same component in the remaining graph. The color-avoiding connected components of an edge-colored graph are maximal sets of vertices such that any two of them are color-avoiding connected. We consider the fraction of vertices contained in color-avoiding connected components of a given size, as well as the fraction of vertices contained in the giant color-avoidin g connected component. It is known that these quantities converge, and the limits can be expressed in terms of probabilities associated to edge-colored branching process trees. We provide explicit formulas for the limit of the fraction of vertices contained in the giant color-avoiding connected component, and we give a simpler asymptotic expression for it in the barely supercritical regime. In addition, in the two-colored case we also provide explicit formulas for the limit of the fraction of vertices contained in color-avoiding connected components of a given size.