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Live-cell RNA imaging with the inactivated endonuclease Csy4 enables new insights into plant virus transport through plasmodesmata
No full textPlant-infecting viruses spread through their hosts by transporting their infectious genomes through intercellular nano-channels called plasmodesmata. This process is mediated by virus-encoded movement proteins. Whilst the sub-cellular localisations of movement proteins have been intensively studied, live-cell RNA imaging systems have so far not been able to detect viral genomes inside the plasmodesmata. Here, we describe a highly sensitive RNA live-cell reporter based on an enzymatically inactive form of the small bacterial endonuclease Csy4, which binds to its cognate stem-loop with picomolar affinity. This system allows imaging of plant viral RNA genomes inside plasmodesmata and shows that potato virus X RNA remains accessible within the channels and is therefore not fully encapsidated during movement. We also combine Csy4-based RNA-imaging with interspecies movement complementation to show that an unrelated movement protein from tobacco mosaic virus can recruit potato virus X replication complexes adjacent to plasmodesmata. Therefore, recruitment of potato virus X replicase is mediated non-specifically, likely by indirect coupling of movement proteins and viral replicase via the viral RNA or co-compartmentalisation, potentially contributing to transport specificity. Lastly, we show that a 'self-tracking' virus can express the Csy4-based reporter during the progress of infection. However, expression of the RNA-binding protein in cis interferes with viral movement by an unidentified mechanism when cognate stem-loops are present in the viral RNA.</p
Visualizing war in Euripides’ <i>Suppliant Women</i>:fog, clarity, and multiple perspectives
No full textThis chapter moves beyond recent recognitions of the instability and hybridity of Euripides’ Suppliant Women in order to highlight a central tension which informs the play and yet has received little critical attention to-date. On the one hand, this tragedy contains plenty of explicit acknowledgement that war is fundamentally confused, chaotic, uncertain and unpredictable. Allied to that recognition is the view that war creates painful sufferings and stark losses which are hard to make sense of, and which cannot be ameliorated by consolatory appeals to just causes or to glory. On the other hand, Suppliant Women contains many voices and perspectives which do indeed visualise war as an activity full of order, purpose and positive meaning. The play develops and juxtaposes multiple perspectives concerning war around this central tension. These diverse ‘visualisations’ constitute the play's depth and richness as serious drama for a mass audience in a war-making city-state
Pausanias' haptic geography:bodies and landscapes in the Periegesis
No full textPausanias has often been represented, by the standards of modern travel writing, as an author who is reticent about describing his personal experiences. There have been some important attempts to reassert the experiential nature of his account, but there is still a tendency to understate the importance of bodies and bodiliness for his text. Repeatedly Pausanias offers us images of mythical and historical bodies immersed in the landscapes he passes through. Every so often, interspersed with those passages, we come across moments where the land is equated with a human body. My aim is to explore the function of those passages within Pausanias’ text. I argue that they imply a conception of antiquarian travel as a surprisingly corporeal enterprise, in the sense that Pausanias appeals repeatedly to the reader’s haptic imagination. I further argue that these passages play an important role in articulating Pausanias’ distinctive vision of the continuing but always elusive presence of the past in the landscapes of Roman Greece. Pausanias has a powerful sense of the permeability between human bodies and the environment and, intertwined with that theme, often articulated through it, an awareness of the permeability between the past and the present
Imagination, mereotopology, and topic expansion
No full textIn the topic-sensitive theory of the logic of imagination due to Berto (2018a), the topic of the imaginative output must be contained within the imaginative input. That is, imaginative episodes can never expand what they are about. We argue, with Badura (2021), that this constraint is implausible from a psychological point of view, and it wrongly predicts the falsehood of true reports of imagination. Thus the constraint should be relaxed; but how? A number of direct approaches to relaxing the controversial content-inclusion constraint are explored in this paper. The core idea is to consider adding an expansion operator to the mereology of topics. The logic that results depends on the formal constraints placed on topic expansion, the choice of which are subject to philosophical dispute. The first semantics we explore is a topological approach using a closure operator, and we show that the resulting logic is the same as Berto’s own system. The second approach uses an inclusive and monotone increasing operator, and we give a sound and complete axiomatisation for its logic. The third approach uses an inclusive and additive operator, and we show that the associated logic is strictly weaker than the previous two systems, and additivity is not definable in the language. The latter result suggests that involved techniques or a more expressive language is required for a complete axiomatization of the system, which is left as an open question. All three systems are simple tweaks on Berto’s system in that the language remains propositional, and the underlying theory of topics is unchanged
Innovating assessment for education for sustainable development
No full textAssessments comprise a major aspect of the learning experience in Education for Sustainable Development (ESD), especially for students. Assessment links to pedagogy, discipline and student progression, supporting learning, upholding standards and preparing learners for graduate roles. Design principles for ESD assessment include future thinking, experiential, collaborative, interdisciplinary, authentic and creative assessment forms. Assessments can be integrated with active learning and flipped classroom approaches. Both formative and summative assessments support learning, with an emphasis on innovation. Many types of assessments are relevant for ESD, including field trips and authentic real-world engagement. Assessments can enable students to work individually or in groups, support active reflective learning, strengthen self-awareness competencies, demand accountability and require students to defend their work in response to questions from different perspectives. Dissertations can be excellent forms of deeper research-based learning, address external sustainability needs, and generate collective celebration of mutual learning. The breadth of assessment can also stimulate interest in sustainable development in students, sometimes shifting their career direction, and can deliver employability and entrepreneurship attributes. There is still a place for the critical essay, but this chapter seeks disruption of traditional assessment approaches and supports wider stakeholder-led assessment approaches befitting the complexities and rewards of ESD
Monitoring and evaluating education for sustainable development:co-creating quality learning experiences and outcomes
No full textEducation for sustainable development (ESD) in a higher education institution is a journey for individuals, departments and the whole institution. Monitoring and evaluation are important to help map and navigate this journey. The first step is to discuss the destination. Once the goals are agreed, there can be a mutual exploration of the meaning and purpose of ESD in a particular context. Indicators are important to allow measurement of baseline and progress. However, it is important that the travellers are kept nourished through knowledge exchange, sharing of good practice and inspiring resources. At regular milestones, it is important to pause and reflect on the journey so far. Perhaps the direction of travel needs to be adjusted, additional team members added to the expedition, or different resources found. Celebration of success is valuable. The journey is as important as the destination, and there are always new paths to travel. Monitoring and evaluation should thus not be seen merely as a closed, constrained process, but rather as a means of navigation that enables dialogue, partnership and exploration of new knowledge and practice horizons through ESD
Zeitflechten
No full textEine Sammlung zusammenhängender Gedichte, die Momente aus verschiedenen Epochen der Geschichte zusammenführt, Zeitgeflechte, die zu einem lebendigen Motivteppich verwoben sind. Eine Übung in den vielfältigen Dimensionen der Zeit und eine Hommage an die schwachen Stimmen der Geschichtezeitflechten erhielt den Staatspreis für Lyrik in Zypern
Time-dependent nonlinear gravity–capillary surface waves with viscous dissipation and wind forcing
No full textWe develop a time-dependent conformal method to study the effect of viscosity on steep surface waves. When the effect of surface tension is included, numerical solutions are found that contain highly oscillatory parasitic capillary ripples. These small-amplitude ripples are associated with the high curvature at the crest of the underlying viscous-gravity wave, and display asymmetry about the wave crest. Previous inviscid studies of steep surface waves have calculated intricate bifurcation structures that appear for small surface tension. We show numerically that viscosity suppresses these. While the discrete solution branches still appear, they collapse to form a single smooth branch in the limit of small surface tension. These solutions are shown to be temporally stable, both to small superharmonic perturbations in a linear stability analysis, and to some larger amplitude perturbations in different initial-value problems. Our work provides a convenient method for the numerical computation and analysis of water waves with viscosity, without evaluating the free-boundary problem for the full Navier–Stokes equations, which becomes increasingly challenging at larger Reynolds numbers
Culture and conservation in baleen whales
No full textCulture, defined as information or behaviours shared within a population and acquired from conspecifics through social learning, acts as a second inheritance system which has important implications for species' ecology and evolution. Understanding the influence of social learning and culture in animals' lives is essential to planning and predicting outcomes of conservation actions. Culture plays a key role in cetaceans’ lives, and some of the best evidence for social learning has come from baleen whales (Mysticetes). The Convention on the Conservation of Migratory Species of Wild Animals (CMS), an international treaty operating under the United Nations Environment Programme (UNEP), has recently integrated animal culture into their conservation initiatives. An essential first step in such a conservation framework is to identify key indicators of social learning in well-studied species, which could be applied to other more elusive species. Here, as part of the UNEP CMS Expert Group on Animal Culture and Social Complexity, we first evaluate key evidence for social learning and culture in baleen whales through several case studies. We then suggest key indicators by behavioural context to assist in identifying potential cases of social learning in more elusive species generating a practical guide for future conservation assessment and management.This article is part of the theme issue ‘Animal culture: conservation in a changing world’
A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS
No full textContext. The discovery and characterization of mini-Neptunes hold a potentially crucial impact on planetary formation and evolution theories. Estimating their orbital parameters and atmospheric properties would provide valuable hints to improve formation and atmospheric models.Aims. We present the discovery of two mini-Neptunes near a 2:1 orbital resonance configuration orbiting the K0 star TOI-1803. We describe in detail their orbital architecture and suggest some possible formation and evolution scenarios.Methods. Using CHEOPS, TESS, and HARPS-N datasets, we estimated the radius and the mass of both planets. We used a multidimensional Gaussian process with a quasi-periodic kernel to disentangle the planetary components from the stellar activity in the HARPS-N dataset. We performed dynamical modeling to explain the orbital configuration and performed planetary formation and evolution simulations. For the least dense planet, we assumed different atmospheric compositions and defined possible atmospheric scenarios with simulated JWST observations.Results. TOI-1803 b and TOI-1803 c have orbital periods of ∼6.3 and ∼12.9 days, respectively, residing in close proximity to a 2:1 orbital resonance. Ground-based photometric follow-up observations have revealed significant transit timing variations (TTV) with an amplitude of ∼10 min and ∼40 min, respectively, for planets b and -c. With the masses computed from the radial velocities dataset, we obtained a density of (0.39 ± 0.10) ρ⊕ and (0.076 ± 0.038) ρ⊕ for planets b and -c, respectively. TOI-1803 c is among the least dense mini-Neptunes currently known, and due to its inflated atmosphere, it is a suitable target for transmission spectroscopy with JWST. With NIRSpec observations, we could understand whether the planet has kept its primary atmosphere or not, which would constrain our formation models.Conclusions. We report the discovery of two mini-Neptunes close to a 2:1 orbital resonance. The detection of significant TTVs from ground-based photometry opens scenarios for a more precise mass determination. TOI-1803 c is one of the least dense mini-Neptunes known so far, and it is of great interest among the scientific community since it could constrain current formation scenarios. JWST observations could give us valuable insights to characterize this interesting system