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Alternative expression of message passing on networks
Get PDFMessage passing techniques on networks encompasses a family of related methods that can be employed to ascertain many important properties of a network. It is widely considered to be the state of the art formulation for networked systems and advances in this method have a wide impact across multiple literatures. One property that message passing can yield is the size of the largest connected component in the network following bond percolation. In this paper, we introduce an alternative method of finding this value that differs from the standard approach. Like the canonical approach, our method is exact on trees and an approximation on arbitrary graphs. We show that our method lends itself to the description of a variety of generalisations of bond percolation such as sequential percolation and non-binary percolation and can yield information about the local environment of a node in percolation equilibrium that the traditional approach cannot.Peer reviewe
Monitoring AGNs with Hβ Asymmetry : V. long-term variation and evolution of the broad Hβ emission-line profiles
No full textFunding: This research is supported by the National Key R&D Program of China (2023YFA1607903 and 2021YFA1600404); by NSFC-11991051, -11991054, -12273041, -12022301, -12333003; by the Key Research Program of Frontier Sciences, CAS, grant QYZDJ-SSW-SLH007, and by the China Manned Space Project under grant No. CMS-CSST-2021-A06. L.C.H. was supported by the National Key R&D Program of China (2022YFF0503401), the National Science Foundation of China (11991052, 12233001), and the China Manned Space Project (CMS-CSST-2021-A04, CMS-CSST-2021-A06). T.E.Z. was funded by the Wyoming NASA Space Grant Consortium, NASA grant No. 80NSSC20M0113.The physical origins of the diverse emission-line asymmetries observed in the spectra of active galactic nuclei (AGNs) are not completely understood. Monitoring the temporal variations of line profiles offers a promising approach to investigating the underlying physics. In this study, we present an analysis of the broad Hβ emission line profiles of eight AGNs observed from 2016–2023 May as part of the reverberation mapping campaign titled "Monitoring AGNs with Hβ Asymmetry," utilizing data obtained from the Wyoming Infrared Observatory 2.3 m telescope. We measure the temporal variations of line asymmetry, width, and central velocity shift for the eight objects. Our findings reveal that the variation in asymmetry is positively correlated with Hβ flux in five of the eight objects, while the remaining objects exhibit negative or complex correlations. Furthermore, we observe anticorrelations between line width and Hβ flux for most objects, indicating the presence of the "breathing" phenomenon in their Hβ emission lines. In contrast, two objects demonstrate an "anti-breathing" phenomenon or complex behavior. We discuss the physical origins of the temporal variations in line profiles and propose the possibility of decomposing the variations in Hβ asymmetry and width into components: one that corresponds to short-term variations in Hβ flux and another that reflects long-term variations in continuum light curves, perhaps driven by radiation pressure.Peer reviewe
Adverse drug reactions, particularly liver disorders, drive interruptions in anti‐tuberculosis treatment : a retrospective cohort study
Get PDFFunding: Medical Research Council. Grant Number: MR/N013166/1.Aims: Adverse drug reactions (ADRs) are a key driver of missed doses of anti‐tuberculosis (TB) therapy. We aimed to determine the relative burden of ADR‐driven missed doses, the missed dose patterns associated with ADRs, and the association between specific ADRs and missed doses. Methods: In this retrospective cohort study, adults (≥18 years) who began the standard 6‐month drug‐sensitive anti‐TB regimen in an outpatient facility in Riga, Latvia (May 2015–September 2022) and missed at least one dose of treatment were included. Data were collected from medical records and observed therapy records. Missed doses were subdivided into early discontinuation or sporadically missed. Descriptive analyses and lasagne plots were used. Results: Across 174 patients, 54 (31.0%, CI: 24.2–37.9%) missed doses due to ADRs. Of 31 320 doses, 4217 (13.5%, CI: 13.1–13.9%) were missed, 20.9% (880/4217, CI: 19.6–22.1%) were due to ADRs. Eighteen (10.3%) of the 174 patients discontinued treatment early, two of which (11.1%) were due to ADRs. Doses missed due to ADRs caused longer yet less frequent periods of sporadic missed doses: 56.4% (479/849) of sporadic missed doses were 1 day in length vs. only 9.1% (7/77) for ADR‐related ones. Hepatobiliary disorders were the leading ADR group causing missed doses. Hepatobiliary ADRs caused long median durations of missed doses (median 15.0, CI: 13.0–22.0). Conclusion: Our study underscores the importance of ADRs as a cause of missed doses of treatment, particularly hepatobiliary disorders. Regimens that are less prone to ADRs and strong healthcare system support structures for patients with ADRs are required to minimize missed doses, reducing unfavourable outcomes.Peer reviewe
The evolutionary ecology of sibling cannibalism in the wild
No full textSibling cannibalism is common amongst animals. Whilst the role relatedness plays in this behaviour has been well studied due to the strong ties between cannibalism and evolutionary theory, we lack enough knowledge of the ecology underlying this behaviour to properly explain its evolution. In this thesis I explore the evolutionary ecology of sibling cannibalism, placing emphasis on integrating ecology into tests of cannibalism and the role of Hamilton’s Rule. I explore inter- and intraspecific variation in cannibalism in four species of lygaeid seed bug in the laboratory, showing that developmental stage is a crucial determinant of cannibalism levels within this group, with cannibalism also being shaped by prior experience of conspecifics in Spilostethus pandurus. Field studies of cannibalism are rare but important if we are to properly understand the ecology of this behaviour. I therefore examine the
predictions of Hamilton’s Rule in hatchlings of the seed bugs Lygaeus creticus and S. pandurus in both the laboratory and the field. The predictions of Hamilton’s Rule were able to explain the lack of kin avoidance, with cannibalism providing a major survival benefit.
Furthermore, I found that the preference shown by L. creticus for conspecific eggs (over heterospecific S. pandurus eggs) was flexible and shaped by post-hatching experience. Whilst patterns of cannibalism were generally similar across the laboratory and field, the unusual preference for kin and reduced consumption of heterospecific L. creticus eggs shown by S. pandurus in the laboratory suggest evolved responses due to the differing ecologies of lab rearing and life in the wild. Considering ecology alongside evolutionary theory provides important contextualisation, improving our understanding of the evolution of sibling cannibalism. As such, the study of sibling cannibalism provides opportunities for more detailed tests of evolutionary theory in behavioural ecology
The role of vision science in understanding animal camouflage
Get PDFAnimal camouflage in the natural world has been studied for over a century, with early research often relying on descriptive accounts of patterning as perceived by human observers. Recent advances, however, have leveraged a deeper understanding of visual processing across a wide range of predators. In this review, we examine literature illustrating how insights from vision science have enriched research on camouflage. We focus on three primary areas: colour and pattern processing, motion processing, and the perception of shape and depth. We discuss findings from vision research that show how animals seeking to remain undetected optimise their camouflage to deter adversaries. We also explore how predator visual systems have evolved to break that camouflage. Lastly, we highlight gaps where vision science has yet to be applied to research on camouflage, with the hope of encouraging further interdisciplinary work.Peer reviewe
Psychological processes underlying normative transformation and social change
Get PDFFunding: This research was supported by the Chilean National Foundation for Scientific and Technological Development (ANID/FONDECYT grant number 1201788), the Center for Social Conflict and Cohesion Studies (ANID/FONDAP grant number 15130009) and the Interdisciplinary Center for Intercultural and Indigenous Studies (ANID/FONDAP grant number 15110006).There have been widespread social changes in the past decade, including changes in gender norms, increases in political polarization and populism, and noticeable shifts toward sustainability. In this Review, we analyze the psychological processes that drive social change, considering factors at the group and individual levels of analysis. We center our analysis around the concept of social norms—socially shared views of what is common or desirable—and argue that the processes that trigger social change often begin when there is a substantive tension between norms within society. Normative tension can occur vertically between norms at the societal level and the norms that emerge at the group level, or between individuals’ normative preferences and the norms of their groups. Normative tension can also occur horizontally between the norms that different groups have regarding their values, preferences, behaviors. We explain how normative tension mobilizes individuals to engage in collective action and how conflicting social norms are contested at the group level. We also highlight individual differences that predispose people to challenge or defend existing social norms. Together, our Review highlights the complex interactions between societal, group and individual-level variables in societal transformations.Peer reviewe
A very readily prepared ligand for rhodium catalysed propene hydroformylation
Get PDFFunding: The authors thank the Eastman Chemical Company for funding.In the search for an easy-to-make ligand that would enable Rh catalyzed hydroformylation of propene to favor the branched aldehydes, iso-butanal, bis-phosphonites and bis-phosphoramidites were designed. Catalysts derived from bis-phosphonites gave the desired low n:iso ratios, but were unstable to hydrolysis. A bis-phosphoramidite ligand (EasyDiPhos) that can be made in just one synthetic step has been discovered that enables Rh-catalyzed hydroformylations to proceed with unusually low n:iso ratios. They were also found to have significant stability to moisture, air, and to relatively high temperatures during hydroformylation conditions. The latter was studied using a combination of high pressure infra-red (HPIR) spectroscopy and NMR analysis of the catalyst resting state after 1 week under relevant conditions. Propene hydroformylation with n:iso ratios well below 1 was carried out and with turnover numbers around 1000 mol/mol in 1 hour reaction time. One of the ligands, whilst not being the most iso-selective example, had a partially flexible n:iso ratio depending on temperature and pressure. Two Pt(II) complexes were prepared and their X-ray crystal structures determined. The most iso-selective catalyst was examined at low temperature (prioritizing iso-selectivity over rates) in hydroformylation of some other terminal alkenes with significant branched selectivity.Peer reviewe
Using Kgen to generate cross-verified apparent equilibrium constants (K∗’s) for palaeoseawater carbonate chemistry
Get PDFFunding: Horizon Europe European Research Council. Grant Number: 805246.Quantification of palaeo pH and palaeo CO2 from marine proxies requires the use of apparent equilibrium constants (K∗’s). The K∗’s required to calculate seawater carbonate chemistry are described by empirically determined calibrations, and for palaeoseawater these calibrations must be adjusted to account for changes in seawater composition. There are a number of possible calibrations that can be used to calculate K∗’s, and each software package for calculating carbonate chemistry separately implements these K∗ calibrations, which are manually verified against previous implementations. Palaeo applications typically only implement a single calibration for each K∗, but have additional complexity from the need to adjust each calibration for changing seawater composition through time. The fragmented approach to K∗ calculation can result in unintended and difficult to resolve discrepancies between outputs calculated by different pieces of software. We present “Kgen,” a synchronised collection of three pieces of software to consistently calculate palaeoseawater K∗’s in Python, R, and Matlab. Kgen provides a simple, and nearly identical interface in each language. Through use of a Continuous Integration/Continuous Delivery (CI/CD) pipeline, Kgen guarantees consistent outputs between languages by automatically cross-checking results from all three implementations. Unifying the approach to K∗ calculation in this way provides an extensible platform for verifiable K∗ generation for palaeoseawater, which can be integrated into existing carbon speciation calculators to improve the consistency of results.Peer reviewe
Chimpanzees rationally revise their beliefs
Get PDFFunding: Jan Engelmann and Emily Sanford were supported by a grant from the Leakey Foundation, and Hanna Schleihauf by an Audacity Grant from the Leibniz ScienceCampus Primate Cognition.The selective revision of beliefs in light of new evidence has been considered one of the hallmarks of human-level rationality. However, tests of this ability in other species are lacking. We examined whether and how chimpanzees (Pan troglodytes) update their initial belief about the location of a reward in response to conflicting evidence. Chimpanzees responded to counter-evidence in ways predicted by a formal model of rational belief revision: they remained committed to their initial belief when the evidence supporting the alternative belief was weaker, but they revised their initial belief when the supporting evidence was stronger. Results suggest that this pattern of belief revision was guided by the explicit representation and weighing of evidence. Taken together, these findings indicate that chimpanzees metacognitively evaluate conflicting pieces of evidence within a reflective process.Peer reviewe
Initiation and evolution of an epicontinental shelf-slope margin in an actively contracting deep-water basin : the Eocene Aínsa Basin, southern Pyrenees (Spain)
No full textFunding: This work was undertaken as part of the first author's PhD studentship and was funded by the Natural Environment Research Council (NERC) Centre for Doctoral Training (CDT) programme.The shelf-slope margin is a geomorphic zone with a change in gradient between subaqueous shelves and slopes, which extends towards the submarine basin-floor. It is important because it partitions distinct sedimentary and biogenic processes between the shallow and deep-water realms. The initiation of a shelf-slope profile from pre-existing conditions, and the evolution of shelf margins in space and time has been the focus of numerous studies, particularly from seismic data sets on passive margins, although markedly less-so from active tectonic settings. This study documents the initiation and evolution of a shelf-slope margin in the well-studied Eocene Aínsa Basin (Spanish Pyrenees) through the segmentation of a mixed carbonate-siliciclastic ramp via contractional tectonics and differential subsidence. The basinward propagation of a series of thrusts through the ramp allowed the maintenance of shallow-water, predominantly carbonate sedimentation on their uplifted hanging wall anticlines. Conversely, the deepened foot wall synclines became muddy slope environments, and their axes became the main loci of siliciclastic turbidity current bypass and deposition. The deflection of turbidity currents around uplifted areas towards the synclinal lows allowed for the continuation of carbonate production at the bathymetric highs, which kept pace with subsidence. The interface between shallow- and deep-water sedimentation (i.e. the shelf-slope margin) was an erosional and composite submarine scarp surface generated by several phases of large-scale mass wasting of the aggrading shelf carbonates, and healing by onlap of slope turbidites against the scarp. Continued thrust propagation and basin deepening led to the progressive headward degradation of the surfaces, resulting in an apparent retrogradation of the shelf-slope margin and onlapping slope deposits. This model for the tectonically controlled conversion of a submarine ramp into a shelf-slope profile contrasts with conventional models that consider shelf-slope margins to be inherently progradational after initiation. This study also challenges the notion that large-scale degradational surfaces and thick successions of submarine landslides are inherently diagnostic of canyons and their fill.Peer reviewe
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