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Pydrofoil: accelerating Sail-based instruction set simulators
No full textWe present Pydrofoil, a multi-stage compiler that generates instruction set simulators (ISSs) from processor instruction set architectures (ISAs) expressed in the high-level, verification-oriented ISA specification language Sail. Pydrofoil shows a > 230x speedup over the C-based ISS generated by Sail on our benchmarks, and is based on the following insights. (i) An ISS is effectively an interpreter loop, and tracing just-in-time (JIT) compilers have proven effective at accelerating those, albeit mostly for dynamically typed languages. (ii) ISS workloads are highly atypical, dominated by intensive bit manipulation operations. Conventional compiler optimisations for general-purpose programming languages have limited impact for speeding up such workloads. We develop suitable domain-specific optimisations. (iii) Neither tracing JIT compilers, nor ahead-of-time (AOT) compilation alone, even with domain-specific optimisations, suffice for the generation of performant ISSs. Pydrofoil therefore implements a hybrid approach, pairing an AOT compiler with a tracing JIT built on the meta-tracing PyPy framework. AOT and JIT use domain-specific optimisations. Our benchmarks demonstrate that combining AOT and JIT compilers provides significantly greater performance gains than using either compiler alone
From landlocked to landlinked, on its own terms:connectivity and mega-projects in Turkmenistan
No full textThis article examines the concept of the mega-project as a lens through which to explore the connectivity strategies of Turkmenistan, a Central Asian republic often portrayed as remote and isolated. Despite its landlocked geography and a cautious foreign policy grounded in permanent neutrality, Turkmenistan has launched a series of large-scale infrastructural initiatives aimed at enhancing its integration into global networks. While the country lacks the geopolitical leverage of other post-Soviet states such as Azerbaijan or Kazakhstan, Turkmenistan has pursued a tous azimuts strategy, seeking to capitalize on all available economic opportunities. Ashgabat foreign policy is closely tied to the imperative of exporting natural gas, the cornerstone of its national economy. Surrounded by landlocked or unstable neighbors, and competing with regional energy powers like Iran and Russia, the country is compelled to explore new routes and markets. In recent years, Turkmenistan has initiated several ambitious projects—some completed, others still in the planning stage—demonstrating a clear intention to overcome structural constraints through infrastructure-led development
A sociocultural analysis of teacher language assessment literacy (LAL) development: Stories from a novice Vietnamese EFL teacher
No full textGuided by sociocultural theory, this single-case narrative inquiry views language assessment literacy development as a process of language assessment concept formation and examines how a teacher’s language assessment concepts were formed, what sociocultural elements mediated those concept formations, and how the focal teacher emotionally experienced those concept formations. To fulfill these aims, approximately 15 hours of audio and video data were collected from a novice Vietnamese teacher of English as a foreign language via interviews, classroom observations, and verbal reports. The data were transformed into narrative vignettes which were then subject to directed content analysis guided by sociocultural theory’s notions of concept and perezhivanie. The study found that teacher assessment concept formation was a long, complex, and ongoing process involving various sociocultural mediators. Notably, the mediation of sociocultural factors was not direct but refracted through the participant’s evolving perezhivanie. Furthermore, empirical concepts derived from the focal teacher’s practical assessment experiences played a more significant role than scientific concepts originating from formal instruction and academic literature. Finally, the study has demonstrated the role of emotions in mediating assessment concept formations. Drawing on these findings, the study argues that language teacher education programs need to integrate best language assessment practices, leverage student teachers’ empirical experiences, and utilize teacher educators’ responsive mediation to support teacher language assessment literacy development
SAM-AMP lyases in type III CRISPR defence
No full textType III CRISPR systems detect non-self RNA and activate the enzymatic Cas10 subunit, which generates nucleotide second messengers for activation of ancillary effectors. Although most signal via cyclic oligoadenylate, an alternative class of signalling molecule SAM-AMP, formed by conjugating ATP and S-adenosylmethionine, was described recently. SAM-AMP activates a trans-membrane effector of the CorA magnesium transporter family to provide anti-phage defence. Intriguingly, immunity also requires SAM-AMP degradation by means of a specialized CRISPR-encoded NrN family phosphodiesterase in Bacteroides fragilis. In Clostridium botulinum, the nrn gene is replaced by a gene encoding a SAM-AMP lyase. Here, we investigate the structure and activity of C. botulinum SAM-AMP lyase, which can substitute for the nrn gene to provide CorA-mediated immunity in Escherichia coli. The structure of SAM-AMP lyase bound to its reaction product 5′-methylthioadenosine-AMP reveals key details of substrate binding and turnover by this PII superfamily protein. Bioinformatic analysis revealed a phage-encoded SAM-AMP lyase that degrades SAM-AMP efficiently in vitro, consistent with an anti-CRISPR function
Hoops, loops and eyewitness reliability:a history of biologically impossible aquatic monsters
No full textHere we outline the history of serpentiform aquatic monster reports and images that contain a zoological impossibility: the presence of loops or arches of the body above the water in a vertically flexing animal body. Images of such serpentiform animals have been common ever since the sixteenth century yet the actual proportion of such eyewitness reports, especially at Loch Ness, has until recently been extremely low, far lower than the proportion of hooped imagery in art portraying the Loch Ness Monster. As the biological impossibility of such arched animals is not widely known, yet the images of such monsters both historically and contemporaneously are extremely common, this allows a test of contemporary eyewitness testimony. Few reports mention vertical arches in freshwater or marine contexts. This low proportion suggests cultural background has not influenced the content of aquatic monster reports, in contrast to previous work in the field. This insight supports the contention that the majority of eyewitness reports are actually based on some underlying physical reality, even if not representing an actual encounter with an unknown species
Identifying key questions and leverage points for plant health in the natural environment
No full textThere is good evidence of the considerable risks to plant health from non-native plant pests in the natural environment (semi-natural habitats). In addition, stakeholders often lack awareness of these risks and may not always implement appropriate biosecurity measures. The challenge is how to implement actions that improve behaviours around plant biosecurity given the limited resources available and under-recognition of this issue within the natural environment and conservation sector. This project used systems thinking to identify leverage points where changes in behaviour, attitudes or processes could improve biosecurity and hence plant health in the natural environment. Systems thinking is a way of framing the complex interactions between people, organisations, processes and policies. Leverage points are places within these complex systems where intervention can cause transformative change. Through a workshop, key leverage points were identified at project, organisational, and systemic levels. Recommendations include the identification by Scottish Government of a responsible organisation for plant health in the natural environment, integrating biosecurity into conservation best practices, and including it in grant schemes for habitat restoration. Other key actions involve mainstreaming biosecurity within government policies, improving plant health monitoring, and balancing biosecurity with biodiversity goals
Critical pedagogies to engage heart, hand and head in education for sustainable development
No full textThe personal and professional lives of our graduates can have a significant impact on the sustainability challenges the world is facing. The ways in which teaching and learning occur will influence the competencies developed and the potential for transformative learning. Critical pedagogical approaches that empower students to analyse and confront social, economic and political injustices lend themselves to Education for Sustainable Development (ESD). However, pragmatic concerns around class size, educator confidence and other issues may constrain possible approaches. The competencies – the knowledge, skills, attributes and values – that graduates develop through their studies can help them contribute to a more sustainable future, supporting their ways of thinking, ways of practising and ways of being. In this chapter, we examine and exemplify pedagogical approaches designed to support students from any discipline to develop the key sustainability competencies. We examine the learning and teaching approaches that can be effective at engaging heart, hands and head. Relational, compassionate and eco-pedagogies can support educators to deepen ESD in inclusive, exciting and transformative ways
Sustainability research, teaching and practice:towards transdisciplinary knowledge co-production in universities
No full textUniversities have a role to play in sustainability transitions, partly through producing, exchanging and implementing knowledge. Knowledge is generated and exchanged through Education for Sustainable Development (ESD) – teaching and learning that supports graduates in gaining knowledge, skills and specific and generic sustainability competencies – but also by undertaking sustainability research, by reflecting on operational aspects and by engaging with local communities and other stakeholders in practice. Research, teaching and practice overlap and influence each other as interlinking arenas of academic activity. Sustainability research covers topics of relevance to understanding sustainability challenges and their solutions using sustainability research attributes, such as transdisciplinary and co-production approaches. ESD can be enhanced through sustainability research led teaching, but ESD can also support teaching-led research. Teaching undergraduate and postgraduate learners the principles and practices of sustainability research is challenging but necessary to prepare future generations of academics. The sustainability of research is also a growing consideration, along with an impact. The connections between sustainability research, sustainability research-led teaching and teaching-led sustainability comprise a relatively unexplored, rich area of possibility in the field of ESD and in support of whole institution change for sustainability