We show that previous results from epistemic network models showing the benefits of decreased connectivity in epistemic networks are not robust across changes in parameter values. Our findings motivate discussion about whether and how such models can inform real-world epistemic communities. As we argue, only robust results from epistemic network models should be used to generate advice for the real-world, and, in particular, decreasing connectivity is a robustly poor recommendation.

In this paper, we examine the relationship between general relativity and the theory of Einstein algebras. We show that according to a formal criterion for theoretical equivalence recently proposed by Halvorson and Weatherall, the two are equivalent theories.

A classic result in the foundations of Yang-Mills theory, due to J. W. Barrett ["Holonomy and Path Structures in General Relativity and Yang-Mills Theory." Int. J. Th. Phys. 30, ], establishes that given a "generalized" holonomy map from the space of piece-wise smooth, closed curves based at some point of a manifold to a Lie group, there exists a principal bundle with that group as structure group and a principal connection on that bundle such that the holonomy map corresponds to (...) the holonomies of that connection. Barrett also provided one sense in which this "recovery theorem" yields a unique bundle, up to isomorphism. Here we show that something stronger is true: with an appropriate definition of isomorphism between generalized holonomy maps, there is an equivalence of categories between the category whose objects are generalized holonomy maps on a smooth, connected manifold and whose arrows are holonomy isomorphisms, and the category whose objects are principal connections on principal bundles over a smooth, connected manifold. This result clarifies, and somewhat improves upon, the sense of "unique recovery" in Barrett's theorems; it also makes precise a sense in which there is no loss of structure involved in moving from a principal bundle formulation of Yang-Mills theory to a holonomy, or "loop", formulation. (shrink)

La pandemia de la COVID-19 evidencia posibilidades, límites y nuevos desafíos para la ciencia abierta. En este artículo se presentan los resultados de una investigación que tuvo como objetivo contribuir a la comprensión del papel de la ciencia ciudadana, una de las vertientes de la ciencia abierta, en el abordaje de los problemas plantados por la pandemia. Para ello, se llevó a cabo una revisión de literatura especializada y se acometió la identificación y la categorización de estas iniciativas ciudadanas en (...) Brasil durante el periodo del brote de COVID-19. Los resultados de esta investigación muestran un aprendizaje mutuo entre los abordajes de la ciencia ciudadana y las acciones participativas para reducir los riesgos de desastres. Este aprendizaje, por un lado, fortalece el papel de la producción ciudadana de datos, información y conocimiento relevante para la prevención, resiliencia y gestión de estos riesgos; y, por otro lado, dilata el alcance de la ciencia ciudadana para afrontar situaciones de emergencia y desastre, al tiempo que refuerza el carácter situado de este enfoque. [pt] A pandemia da COVID-19 evidencia possibilidades, limites e novos desafios à abertura da ciência. Neste artigo, apresentam-se resultados de pesquisa que objetivou contribuir para o entendimento do papel da ciência cidadã, uma das vertentes da ciência aberta, para lidar com as questões postas pela pandemia. Além de revisão da literatura, o estudo envolveu a identificação e a categorização de iniciativas cidadãs dessa natureza, no Brasil, durante o período de eclosão da COVID-19. Observa-se o aprendizado mútuo entre as abordagens da ciência cidadã e as ações participativas para redução de riscos de desastre. De um lado, fortalece o papel da produção cidadã de dados, informações e conhecimentos relevantes à prevenção, resiliência e gestão desses riscos; e, de outro, alarga o escopo da ciência cidadã para o enfrentamento de situações de emergência e desastre, ao mesmo tempo em que reforça o caráter situado dessa abordagem. (shrink)

Reactive oxygen species (ROS) are highly reactive molecules produced in cells. So far, they have mostly been connected to diseases and pathological conditions. More recent results revealed a somewhat unexpected role of ROS in control of developmental processes. In this review, we elaborate on ROS in development, focussing on their connection to epithelial tissue morphogenesis. After briefly summarising unique characteristics of epithelial cells, we present some characteristic features of ROS species, their production and targets, with a focus on proteins important (...) for epithelial development and function. Finally, we provide examples of regulation of epithelial morphogenesis by ROS, and also of developmental genes that regulate the overall redox status. We conclude by discussing future avenues of research that will further elucidate ROS regulation in epithelial development. (shrink)

Hobbes and Rousseau relied heavily upon the time-worn metaphor of the body politic to describe and explain their respective political visions. But while Rousseau’s use of the metaphor is largely ac...

The principle of homophily says that people associate with other groups of people who are mostly like themselves. Many online communities are structured around groups of socially similar individuals. On Twitter, however, people are exposed to multiple, diverse points of view through the public timeline. The authors captured 30,000 tweets about the shooting of George Tiller, a late-term abortion doctor, and the subsequent conversations among pro-life and pro-choice advocates. They found that replies between like-minded individuals strengthen group identity, whereas replies (...) between different-minded individuals reinforce in-group and out-group affiliation. Their results show that people are exposed to broader viewpoints than they were before but are limited in their ability to engage in meaningful discussion. They conclude with implications for different kinds of social participation on Twitter more generally. (shrink)

To make sense of large data sets, we often look for patterns in how data points are “shaped” in the space of possible measurement outcomes. The emerging field of topological data analysis offers a toolkit for formalizing the process of identifying such shapes. This article aims to discover why and how the resulting analysis should be understood as reflecting significant features of the systems that generated the data. I argue that a particular feature of TDA—its functoriality—is what enables TDA to (...) translate visual intuitions about structure in data into precise, computationally tractable descriptions of real-world systems. (shrink)

In this age of “free-sex”, gurus, Hare-Krishna chanters and transcendental meditation teachers J. Кrisimamurti stands almost alone as a non-guru of outstanding grandeur. His lecture tours in major centers of the world remind one of the historical Buddha who reversed the Upanishadic tradition of teaching in a forest hermitage to a select few by travelling on foot from village to village in North-Eastern India to carry his message of love, compassion and understanding to the masses regardless of caste, color or (...) sex. But historical comparisons are never complete. Whereas the Buddha used the local dialect, adapted his message to the intellectual level of his audience and made free use of stories and parables, Krishna-multi lectures in the English language in his intense analytic style to rapt audiences without any such aid. No wonder the Buddha's appeal and impact historically has been infinitely wider than that of Krishnamurti. And yet, both eschewed dogma, tradition and metaphysical subtleties, and deliberately refused to offer any sugar-coated pills and panaceas for overcoming the pervasive human condition of suffering. They endeavoured to make people “see” and “understand” the human condition in an act of total awareness so as to take them to the very brink of that “creative emptiness”, ultimate freedom and radical change which alone is conducive to the attainment of transcendent peace. In other words, the doctrine of Krishnamurti as that of the Buddha is not for the weak and effeminate who need “crutches” of all kinds but for those who have the courage to help themselves by an act of understanding the way things are without being entangled in theories and conceptual puzzles. It is the intention of this paper to analyze, understand and critically evaluate Krishamurti's concepts of self, action and freedom. (shrink)

Using results from evolutionary game theory, we analyze the conditions under which guilt can provide individual fitness benefits to actors, and so evolve. In particular, we focus on the individual benefits of guilty apology. We find that guilty apology is more likely to evolve in cases where actors interact repeatedly over long periods of time, where the costs of apology are low or moderate, and where guilt is hard to fake.

Poets are "the institutors of laws, and the founders of civil society, and the inventors of the arts of life, and the teachers who draw into a certain ...

This manuscript is intended as a technical supplement to Rosenstock and O'Connor. Calculations are presented for the expected return for strategic players of an iterated prisoner's dilemma which includes guilt-prone grim trigger players, who apologize when they accidentally defect, as well as fake apologizers who in fact act as defectors. See Rosenstock and O'Connor for a discussion of how the results presented here can be interpreted, using ESS analysis and exploring basins of attraction under the replicator dynamics, to help understand (...) the conditions under which guilt can evolve. I hope for this note to both make it easier for others to understand and build on those results, and to demonstrate how expected returns can be calculated for various strategies in various games. (shrink)

Berichte zur Wissenschaftsgeschichte, EarlyView.

Mothers use online resources frequently to obtain information on pregnancy, birth, and parenting. Yet, second-time mothers may have different concerns than first-time mothers given they have a newborn infant and another child at home. The current study conducted an on-line textual analysis of the posts of second-time mothers during pregnancy and the first months postpartum on the BabyCenter LLC website, one of the largest online parenting communities. Latent Dirichlet Allocation analysis on roughly 16,000 posts to BabyCenter birth clubs in 2017 (...) by approximately 4,000 users revealed second-time mothers relied on the online support of the BabyCenter community to share and discuss topics of pregnancy, birth, and child rearing. Second-time mothers also raised questions about preparing their firstborn children for a new baby sibling, how they would care for two children, whether they would love the second one as much as the first, and how the second child would change family dynamics. Future research needs to recognize that second-time mothers may have distinct concerns surrounding the birth of their second baby, and antenatal education and parenting classes may need to be modified to be more inclusive of these women’s needs and perspectives. Online parenting communities offer avenues to support women as they make the transition from one child to two and may provide targeted opportunities to disseminate evidence-based practices that can assist these women and their children. (shrink)

Comparative study on the fundamentals of Advaita Vedanta and Mādhyamika Buddhism.