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Movement trajectories reflect active information acquisition by an echolocating porpoise in a target discrimination task
Get PDFFunding: This work was supported by Office of Naval Research Multidisciplinary University Research Initiatives Program Grant Nos. N00014-18-1\u20132069, N00014-20-1\u20102709, and N00014-23-12065. M.L., K.B., and P.T.M. were supported in part by a Carlsberg Foundation Semper Ardens grant SensAction when contributing to the writing of the manuscript.Voluntary movements of echolocating animals with respect to targets in natural foraging or laboratory target discrimination tasks have long been interpreted as a closed-loop sensorimotor feedback driven by information in previously received echoes. However, what can we infer about sensorimotor integration and auditory information-gathering from animal movement trajectories? In this work, we use unsupervised clustering to analyze the movement trajectories of a free-swimming, echolocating harbor porpoise trained to select a sphere against prolate spheroids of varying aspect ratios presented at different angles, and show that the animal's discrimination performance and overall trajectory can be explained by task difficulty based on the similarity of target echo spectra received during its initial approach. The porpoise continued to evaluate its target selection via incoming echoes throughout the trials, and reversed its decision at very close ranges in a subset of trials. In more challenging scenarios, the animal engaged in prolonged, focused ensonification of a single target, sometimes via buzzes, which we interpret as an evidence accumulation process toward decision making. Our findings highlight movement, in addition to acoustic emissions, as a key behavioral readout in the active information acquisition process embodied in echolocation.Peer reviewe
Inequality trends in general health among young people across the 2001, 2011, and 2021 UK censuses
Get PDFFunding: This study is part of the PhD project KM is undertaking at the University of St Andrews as a member of staff. Therefore, there was no specific funding associated with completing this study. JI is supported by the Medical Research Council (MC_UU_00022/1) and the Scottish Government Health and Social Care Directorate (SHPSU16).Background Evidence on health inequalities among young people is patchy compared to that among adults and younger children. This study examined the association between self-rated general health and a family’s socioeconomic position among 10–24 year olds. Methods We utilised 2001, 2011 and 2021 census microdata from England and Wales, and 2001 and 2011 data from Scotland. Descriptive methods were used to determine differences in general health status by sociodemographic variables, and logistic regression analysis to calculate the odds of reporting poor health according to the National Statistics Socio-economic Classification (NS-SEC) of the household reference person (HRP). Logistic regression models controlled for the effects of age, gender, household-level deprivation of education and housing, and UK region. Results We observed the same socioeconomic patterning of health over the period of twenty years. All occupational groups had higher rates of poor health compared to the least disadvantaged group of young people. Compared to young people from households where the HRP belonged to the managerial or professional NS-SEC group, all other groups, except those self-employed in 2001, had greater odds of reporting poor health. The odds were highest among young people from households where the HRP had never worked or was long-term unemployed: 2.7 times in 2001, 3.1 times in 2011 and 3.6 times in 2021 (p<0.001). Conclusions We observed a similar social gradient of self-reported poor health across the 2001, 2011 and 2021 census datasets; as disadvantage increased, the share of young people with fair or poor health increasedPeer reviewe
Evidence to support integrating feedback best practice for computer-based assessment in pharmacology education
Get PDFFeedback is the most powerful driver of learning, but it can afford variable effects depending on the method used. The design of feedback for computer-based assessment—now increasingly prevalent in higher education—remains relatively underexplored, particularly for pharmacology education. The growing momentum of curricular evolution in pharmacology education presents a timely opportunity to appraise and improve feedback practices in computer-based assessment within the discipline. While there is extensive literature which outlines the principles of effective feedback, there is not a universal model we can apply with consistently positive outcomes. This review explores how empirical evidence can inform the development of effective feedback for use in computer-based assessment. Drawing on findings from multiple meta-analyses and primary research exploring elements of feedback design from across disciplines, this review confirms that elaborate feedback is more effective than corrective feedback alone. However, to support students to develop metacognitive skills for life-long learning, feedback should be tailored to the characteristics of the learner with dialogic support necessary to optimize impact. It is also clear that a key prognostic indicator of successful feedback for performance and satisfaction is clear links to goals and standards. This review argues for feedback for computer-based assessment to go beyond that which is efficient. Instead, it should be constructively aligned with clear goals, and be learner-centred and dialogic to ensure we support the development of reflective and capable graduates of pharmacology education.Peer reviewe
Phase transitions in nonreciprocal driven-dissipative condensates
Get PDFFunding: his work was supported by the Air Force Office of Scientific Research MURI program under Grant No. FA9550-19-1-0399, the Simons Foundation through a Simons Investigator award (Grant No. 669487), and was completed in part with resources provided by the University of Chicago’s Research Computing Center. R. H. was supported by a Grant in Aid for Scientific Research (B) (General) (No. 25K00935), for Transformative Research Areas (No. 25H01364), and for Research Activity Start-up from JSPS in Japan (No. 23K19034). C. W. was partially supported by NSF-MPS-PHY Grant No. 2207383. This research benefited from Physics Frontier Center for Living Systems funded by the National Science Foundation (PHY- 2317138).We investigate the influence of boundaries and spatial nonreciprocity on nonequilibrium driven-dissipative phase transitions. We focus on a one-dimensional lattice of nonlinear bosons described by a Lindblad master equation, where the interplay between coherent and incoherent dynamics generates nonreciprocal interactions between sites. Using a mean-field approach, we analyze the phase diagram under both periodic and open boundary conditions. For periodic boundaries, the system always forms a condensate at nonzero momentum and frequency, resulting in a time-dependent traveling wave pattern. In contrast, open boundaries reveal a far richer phase diagram, featuring multiple static and dynamical phases, as well as exotic phase transitions, including the spontaneous breaking of particle-hole symmetry associated with a critical exceptional point and phases with distinct bulk and edge behavior. Our model does not require postselection and is experimentally realizable in platforms such as superconducting circuits.Peer reviewe
A phosphoramidate modification of FUDR, NUC-3373, causes DNA damage and DAMPs release from colorectal cancer cells, potentiating lymphocyte-induced cell death
Get PDFFunding: This research was funded in part by NuCana plc.The funder provided support in the form of salaries for authors OR, ME, JB, & DJH and also provided some laboratory costs but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide with 5-FU still the primary chemotherapeutic of choice. With the increasing use of immunotherapies, much research is focused on the ability to make tumours more immunogenic, thereby rationalising combination with immunotherapy. Here we investigate whether NUC-3373, a phosphoramidate transformation of 5-fluorodeoxyuridine (FUDR), enhances immunogenicity in CRC cell lines and facilitates lymphocyte mediated cell death in vitro. At sub IC50 doses NUC-3373 upregulates damage associate molecular patterns (DAMPs) in both HCT116 and SW480 cells and increases surface expression of MHCII and PD-L1. Pre-treatment with NUC-3373 and subsequent coculture with NK-92 MI natural killer cells caused an increase in LAMP1 expression (degranulation), production of IFN-γ, and NK-mediated cytotoxicity compared to vehicle controls. Cocultures with patient-derived PBMCs with heterologous CRC cells pre-treated with NUC-3373 demonstrated increased cell death compared to both vehicle controls and monocultures of CRC cells exposed to NUC-3373. Lastly, the PD-1 immune checkpoint inhibitor nivolumab showed synergistic activity when HCT116 cells were pre-treated with NUC-3373. To conclude, we show that NUC-3373 can modulate immune signaling and may therefore facilitate immune mediated tumour cell death in vitro.Peer reviewe
Grid cell distortion is associated with increased distance estimation error in polarised environments
Get PDFGrid cells within the medial entorhinal cortex (MEC) exhibit a regular hexagonal pattern of firing fields which has been hypothesised to provide a universal spatial metric supporting spatial memory and navigation. This could be used to support a cognitive map, our internal representation of external space and consistent with this, disruption of the MEC impairs spatial memory and place cell anchoring to external visual cues. However, the highly regular and repetitive nature of the firing fields in grid cells is also ideally suited to support path integration. Indeed, genetic silencing of stellate cells in MEC, results in impaired distance estimation, supporting the MEC’s role in path integration. However, few studies have examined the role of grid cell firing during active navigation. Several studies have reported that manipulation of environmental cues, recent experience and reward location distort the grid signal, but most relevant here is that the grid signal distorts in polarising environments, such as trapezoids. If grid cells support distance estimation and path integration, then disruption of the grid regularity such as those seen in polarised environments should impair these processes. Here we report that both rats and humans have impaired distance estimation in polarised environments. Grid regularity was again reported to be distorted in polarised environments, and this was correlated with impaired distance estimation in rats. Grid regularity was also distorted by recent experience. These findings are consistent with grid cells supporting distance estimation in navigation.Peer reviewe
Fate of poor man's Majoranas in the long Kitaev chain limit
Get PDFFunding: This work was supported as a part of NCCR SPIN, a National Centre of Competence in Research, funded by the Swiss National Science Foundation (Grant No. 225153). This project received funding from the European Union's Horizon 2020 research and innovation program (ERC Starting Grant, Grant Agreement No. 757725). H.F.L. acknowledges support by the Georg H. Endress Foundation.A minimal Kitaev chain, consisting of two quantum dots connected via a superconductor, can host highly localized near-zero-energy states, known as poor man's Majoranas (PMMs). These states have been proposed as promising candidates to study Majorana bound states (MBSs) in a highly tunable setup. However, it is unclear whether and how PMMs observed in real systems are actually connected to the topological phase of the full Kitaev chain. Here, we study PMMs using a microscopic model and show that, in the long chain limit, not all PMMs are related to topological states. Rather, in long chains, some PMMs evolve into trivial highly localized low-energy states. We provide an explanation for the occurrence of these states and show that there is no clear conductance signature that is able to distinguish PMMs that evolve into true topological states from PMMs that evolve into trivial states.Peer reviewe
Wall-crossing from Lagrangian cobordisms
Get PDFFunding: This work was partially supported by NSF grants DMS-1406274 and DMS-1344991, Simons Foundation grant 385573, Simons Collaboration on Homological Mirror Symmetry, EPSRC grant EP/N03189X/1, Classification, computation and construction: new methods in geometry, and ERC grant 850713.Biran and Cornea showed that monotone Lagrangian cobordisms give an equivalence of objects in the Fukaya category. However, there are currently no known nontrivial examples of monotone Lagrangian cobordisms with two ends. We look at an extension of their theory to the pearly model of Lagrangian Floer cohomology and unobstructed Lagrangian cobordisms. In particular, we examine the suspension cobordism of a Hamiltonian isotopy and the Haug mutation cobordism between mutant Lagrangian surfaces. In both cases we show that these Lagrangian cobordisms can be unobstructed by a bounding cochain, and additionally induce an A∞ homomorphism between the Floer cohomology of the ends. This gives a first example of a two-ended Lagrangian cobordism giving a nontrivial equivalence of Lagrangian Floer cohomology. A brief computation is also included which shows that the incorporation of a bounding cochain from this equivalence accounts for the “instanton-corrections” considered by Auroux (2007), Pascaleff and Tonkonog (2020) and Rizell, Ekholm and Tonkonog (2022) for the wall-crossing formula between Chekanov and product tori in ℂ2 \ {z1z2 = 1}. We additionally prove some auxiliary results that may be of independent interest. These include a weakly filtered version of the Whitehead theorem for A∞ algebras and an extension of Charest and Woodward’s stabilizing divisor model of Lagrangian Floer cohomology to Lagrangian cobordisms.Peer reviewe
The adaptive role of bark in the diet of Budongo chimpanzees (Pan troglodytes schweinfurthii)
Get PDFThe authors would like to thank the Royal Zoological Society of Scotland which provides core funding that keeps the station operational, and Uganda Wildlife Authority and Uganda National Council for Science and Technology for granting permission to work in the country. EF was funded by Keble College, Oxford, the Clarendon Fund, the British Institute of Eastern Africa, and the Explorers Club. CH and GB received funding from the European Union's 8th Framework Programme, Horizon 2020, under grant agreement no. 802719.The ingestion of bark has been observed across the animal kingdom and is well documented in free-ranging chimpanzees. Thus far, the best-supported hypothesis for the adaptive function of this behavior is the fallback food hypothesis, which asserts that chimpanzees consume bark and cambium when preferred foods are scarce. However, alternative explanations exist, including the essential nutrient and mineral hypothesis, the self-medication hypothesis, and the stressed-tree hypothesis. We tested whether the fallback food hypothesis can explain bark-feeding across two communities of Eastern chimpanzees (Pan troglodytes schweinfurthii) in the Budongo Forest, Uganda. We used 13 years of the site’s long-term behavioral data, 5 years of food availability data, and 8 months of direct and indirect observations. We also conducted eight 400-m line transects to collect data on the distribution of tree species across community home ranges. We employed several analyses, including Pearson correlation tests, qualitative comparisons of descriptive data and heat maps, and interpretation of behavioral anecdotes. We found varying patterns of bark-feeding seasonality across tree species, with bark-feeding on several species showing no correlation with food scarcity. We also identified differences in the amounts of bark targeted between tree species and report anecdotal evidence of chimpanzees prioritizing bark over high-value foods. Lastly, we found that bark-feeding on certain species disproportionally occurs far from community core areas, despite relative abundance of these species within the home range. As a result, we argue that the fallback food hypothesis cannot explain bark-feeding across all tree species. Instead, we present supporting evidence for several alternative hypotheses, including self-medication, thereby challenging the widely accepted function of this behavior.Peer reviewe
Collective action under repressive conditions: : integration of individual, group, and structural level research, recommendations, and reflections
Get PDFFunding: Open access funding enabled and organized by Projekt DEAL.Social scientific research from different traditions on collective action under repressive conditions is fragmented across different levels of analysis. The current paper takes a first step toward remedying this fragmentation by reviewing research findings on repression and collective action and organizing them into a multilevel framework. We describe the impact of repression on antecedents of collective action at the (a) individual level (including grievances, emotions, efficacy beliefs, politicized identity, and individual differences), (b) group level (including community cohesion and norms), and (c) structural level (including political opportunities and socioecological conditions). We then present an integrative summary reflecting on the broad patterns we observed in the literature. We conclude with policy implications of this work, suggesting recommendations for activists to overcome repression, for authorities to foster pluralist political participation while maintaining stability, and for researchers to further advance knowledge on repression and collective action.Peer reviewe
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