Swarthmore College

Urban areas are characterised by the presence of sensory pollutants, such as anthropogenic noise and artificial light at night (ALAN). Animals can quickly adapt to novel environmental conditions by adjusting their behaviour, which is proximately regulated by endocrine systems. While endocrine responses to sensory pollution have been widely reported, this has not often been linked to changes in behaviour, hampering the understanding of adaptiveness of endocrine responses. Our aim was, therefore, to investigate the effects of urbanisation, specifically urban noise and light pollution, on hormone levels in male urban and forest túngara frogs (Engystomops pustulosus), a species with reported population divergence in behaviour in response to urbanisation. We quantified testosterone and corticosterone release rates in the field and in the lab before and after exposure to urban noise and/or light. We show that urban and forest frogs differ in their endocrine phenotypes under field as well as lab conditions. Moreover, in urban frogs exposure to urban noise and light led, respectively, to an increase in testosterone and decrease in corticosterone, whereas in forest frogs sensory pollutants did not elicit any endo-crine response. Our results show that urbanisation, specifically noise and light pollution, can modulate hormone levels in urban and forest populations differentially. The observed endocrine responses are consistent with the observed behavioural changes in urban frogs, providing a proximate explanation for the presumably adaptive behavioural changes in response to urbanisation.

Rumination predicts wellbeing and is a core construct in the cognitive vulnerabilities to depression literature. Traditional measures of depressive rumination (e.g., Ruminative Responses Subscale, RRS; Treynor et al., 2003) rarely include items capturing thoughts about problems or events, even though these thoughts are in measures of related constructs (e.g., co-rumination, post-event processing). We created the Rumination on Problems Questionnaire (RPQ) for use on its own and with the RRS to capture rumination about problems and to align with measures of other ruminative and repetitive thinking processes. Our cross-sectional study of 927 undergraduates revealed the RPQ had a single factor, good internal reliability, convergent and discriminant validity, and significantly predicted depression, anxiety, and stress controlling for the RRS and co-rumination. Researchers and clinicians interested in rumination or cognitive vulnerabilities may wish to include the RPQ in their assessments. Measuring and addressing problem-focused rumination may be an important transdiagnostic treatment and prevention goal.

We apply the Berglund–Hübsch transpose rule from BHK mirror symmetry to show that to an n-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n-1$$\end{document}-dimensional Calabi–Yau orbifold in weighted projective space defined by an invertible polynomial, we can associate four (possibly) distinct Sasaki manifolds of dimension 2n+1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$2n+1$$\end{document} which are n-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n-1$$\end{document}-connected and admit a metric of positive Ricci curvature. We apply this theorem to show that for a given K3 orbifold, there exist four seven-dimensional Sasakian manifolds of positive Ricci curvature, two of which are actually Sasaki–Einstein.

The City of Philadelphia, like many American cities, grapples with challenges that have distinctly “behavioral” components. Starting in 2016, city leadership in the mayor’s office partnered with local academics working in the behavioral sciences to form the Philadelphia Behavioral Science Initiative (PBSI). This chapter tells the story of PBSI, focusing on how it was formed as a true collaboration between academia and government, how it works in practice, and what the future holds for the initiative. Along the way, we focus on projects that have and have not been successful and discuss lessons learned for others hoping to emulate this model of applied behavioral science in large American cities.

The dissolution of anthropogenic carbon dioxide (CO 2 ) in seawater has altered its carbonate chemistry in the process of ocean acidification (OA). OA affects the viability of marine species. In particular, calcifying organisms and their early planktonic larval stages are considered vulnerable. These organisms often utilize energy reserves for metabolism rather than growth and calcification as supported by bulk RNA‐sequencing (RNA‐seq) experiments. Yet, transcriptomic profiling of a bulk sample reflects the average gene expression of the population, neglecting the variations between individuals, which forms the basis for natural selection. Here, we used single‐embryo RNA‐seq on larval sea urchin Heliocidaris crassispina , which is a commercially and ecologically valuable species in East Asia, to document gene expression changes to OA at an individual and family level. Three paternal half‐sibs groups were fertilized and exposed to 3 pH conditions (ambient pH 8.0, 7.7 and 7.4) for 12 h prior to sequencing and oxygen consumption assay. The resulting transcriptomic profile of all embryos can be distinguished into four clusters, with differences in gene expressions that govern biomineralization, cell differentiation and patterning, as well as metabolism. While these responses were influenced by pH conditions, the male identities also had an effect. Specifically, a regression model and goodness of fit tests indicated a significant interaction between sire and pH on the probability of embryo membership in different clusters of gene expression. The single‐embryo RNA‐seq approach is promising in climate stressor research because not only does it highlight potential impacts before phenotypic changes were observed, but it also highlights variations between individuals and lineages, thus enabling a better determination of evolutionary potential.

This year marks the 75th anniversary of what the UN itself understands to be its first peacekeeping operation. It is therefore an appropriate time to reflect on the track record of UN peacekeeping in its efforts to try to maintain and realize peace and security. Moreover, this milestone invites us to ponder what lies ahead in the realm of peacekeeping. For this reason, this forum article brings together both academics and UN officials to assess the achievements and challenges of UN peacekeeping over the past 75 years. Through a dialogue among peacekeeping scholars and practitioners, we hope to identify current trends and developments in UN peacekeeping, as well as explore priorities for the future to improve the effectiveness of peacekeeping operations in terms of achieving their mandate objectives, such as maintaining peace, protecting civilians, promoting human rights, and facilitating reconciliation. This forum article is structured into six thematic sections, each shedding light on various aspects of UN peacekeeping: (1) foundational principles of UN peacekeeping - namely, consent, impartiality, and the (non-)use of force; (2) protection of civilians; (3) the primacy of politics; (4) early warning; (5) cooperation with regional organizations; and (6) the changing geopolitical landscape in which UN peacekeeping operates.

Social media platform affordances allow users to interact with content and with each other in diverse ways. For example, on Twitter ¹ , users can like, reply, retweet, or quote another tweet. Though it’s clear that these different features allow various types of interactions, open questions remain about how these different affordances shape the conversations. We examine how two similar, but distinct conversational features on Twitter — specifically reply vs. quote — are used differently. Focusing on the polarized discourse around Robert Mueller’s congressional testimony in July 2019, we look at how these features are employed in conversations between politically aligned and opposed accounts. We use a mixed methods approach, employing grounded qualitative analysis to identify the different conversational and framing strategies salient in that discourse and then quantitatively analyzing how those techniques differed across the different features and political alignments. Our research (1) demonstrates that the quote feature is more often used to broadcast and reply is more often used to reframe the conversation; (2) identifies the different framing strategies that emerge through the use of these features when engaging with politically aligned vs. opposed accounts; (3) discusses how reply and quote features may be re-designed to reduce the adversarial tone of polarized conversations on Twitter-like platforms.

Taboo topics in deaf communities include the usual ones found in spoken languages, as well as ones particular to deaf experiences, both in how deaf people relate to hearing people and how deaf people interact with other deaf people. Attention to these topics can help linguists understand better the consequences of field method choices and lead them to adopt better ones. Taboo expressions in American Sign Language are innovative regarding the linguistic structures they play with. This creativity is evident across the grammar in non-taboo expressions, but seems to revel in profane ones. When it comes to the syntax, however, certain types of structures occur in taboo expressions that are all but absent elsewhere, showing grammatical possibilities that might have gone unnoticed without attention to taboo. Taboo expressions are innovative, as well, in how they respond to changing culture, where lexical items that are incoherent with community sensibilities are 'corrected'.

The authors share an online collaborative problem-solving activity that integrates support for students’ developing conceptual understanding, focused engagement, and positive feelings of agency and identity.

Bad feelings—feelings like anger, envy, spite, and contempt—are widely seen as obstacles to a good life. You’re supposed to do your best not to feel them or to get over them as quickly as you can, otherwise they’ll take over and turn you into a monster. Dancing with the Devil: Why Bad Feelings Make Life Good argues that we don’t have to battle our negative emotions or “channel” them into something productive. Bad feelings are expressions of the attachment you have for yourself and your life. You experience negative emotions because your life matters to you. Bad feelings aren’t obstacles to a good life; they are part of what makes life meaningful.

More than half the world’s population live in violent settings, such as civil wars, communal conflicts, cities plagued by gang violence, and entire areas governed by criminal organizations. Living exposed to diverse forms of violence, individuals and communities have found innovative—and sometimes counterintuitive—ways to protect themselves and others. This volume aims to establish the study of civilian agency and its protective dimension across various violent settings as a systematic and unified field of research. It brings together researchers spanning several social science disciplines to study civilian protective agency in different violent settings, including civil war, genocide, communal violence, and organized crime, and in various geographical locations, from Syria to Mozambique, Sri Lanka to Mexico, Iraq to Colombia, and Western Europe. The volume offers conceptual foundations, new theoretical insights, and detailed empirics that advance our understanding of civilian protective agency and its impacts on the dynamics of violence, harm reduction, and local peacebuilding. In doing so, it lays the groundwork for future research on the topic that is comparable, tractable, and cumulative.

Given a flag variety \({{\,\textrm{Fl}\,}}(n;r_1, \dots , r_\rho )\), there is natural ring morphism from the symmetric polynomial ring in \(r_1\) variables to the quantum cohomology of the flag variety. In this paper, we show that for a large class of partitions \(\lambda \), the image of \(s_\lambda \) under the ring homomorphism is a Schubert class which is described by partitioning \(\lambda \) into a quantum hook (or q-hook) and a tuple of smaller partitions. We use this result to show that the Plücker coordinate mirror of the flag variety describes quantum cohomology relations. This gives new insight into the structure of this superpotential, and the relation between superpotentials of flag varieties and those of Grassmannians (where the superpotential was introduced by Marsh–Rietsch).