26 research outputs found
Local Termination: theory and practice
The characterisation of termination using well-founded monotone algebras has
been a milestone on the way to automated termination techniques, of which we
have seen an extensive development over the past years. Both the semantic
characterisation and most known termination methods are concerned with global
termination, uniformly of all the terms of a term rewriting system (TRS). In
this paper we consider local termination, of specific sets of terms within a
given TRS. The principal goal of this paper is generalising the semantic
characterisation of global termination to local termination. This is made
possible by admitting the well-founded monotone algebras to be partial. We also
extend our approach to local relative termination. The interest in local
termination naturally arises in program verification, where one is probably
interested only in sensible inputs, or just wants to characterise the set of
inputs for which a program terminates. Local termination will be also be of
interest when dealing with a specific class of terms within a TRS that is known
to be non-terminating, such as combinatory logic (CL) or a TRS encoding
recursive program schemes or Turing machines. We show how some of the
well-known techniques for proving global termination, such as stepwise removal
of rewrite rules and semantic labelling, can be adapted to the local case. We
also describe transformations reducing local to global termination problems.
The resulting techniques for proving local termination have in some cases
already been automated. One of our applications concerns the characterisation
of the terminating S-terms in CL as regular language. Previously this language
had already been found via a tedious analysis of the reduction behaviour of
S-terms. These findings have now been vindicated by a fully automated and
verified proof
Intra-annual variability of biological, chemical and physical parameters at the Senghor seamount Cruise No. MSM61 18.02.2017 – 27.02.2017, Mindelo (Cabo Verde) – Las Palmas (Spain)
The main goal of cruise MSM61 was to install an autonomous multidisciplinary observatory at the summit of Senghor Seamount off the Cape Verdean archipelago. A suite of different mobile and moored instrument platforms equipped with physical, biological and biogeochemical instruments was deployed during the cruise in order to investigate spatio-temporal variability of physical and biogeochemical conditions and how these affect the local ecosystem at this openocean seamount. The research program further included hydrographic work, biological and biogeochemical sampling as well as video transects in the meso- and bathypelagic zones both at Senghor Seamount and at the Cape Verde Ocean Observatory (CVOO)
Thoracic Electrical Impedance Tomography—The 2022 Veterinary Consensus Statement
Electrical impedance tomography (EIT) is a non-invasive real-time non-ionising imaging modality that has many applications. Since the first recorded use in 1978, the technology has become more widely used especially in human adult and neonatal critical care monitoring. Recently, there has been an increase in research on thoracic EIT in veterinary medicine. Real-time imaging of the thorax allows evaluation of ventilation distribution in anesthetised and conscious animals. As the technology becomes recognised in the veterinary community there is a need to standardize approaches to data collection, analysis, interpretation and nomenclature, ensuring comparison and repeatability between researchers and studies. A group of nineteen veterinarians and two biomedical engineers experienced in veterinary EIT were consulted and contributed to the preparation of this statement. The aim of this consensus is to provide an introduction to this imaging modality, to highlight clinical relevance and to include recommendations on how to effectively use thoracic EIT in veterinary species. Based on this, the consensus statement aims to address the need for a streamlined approach to veterinary thoracic EIT and includes: an introduction to the use of EIT in veterinary species, the technical background to creation of the functional images, a consensus from all contributing authors on the practical application and use of the technology, descriptions and interpretation of current available variables including appropriate statistical analysis, nomenclature recommended for consistency and future developments in thoracic EIT. The information provided in this consensus statement may benefit researchers and clinicians working within the field of veterinary thoracic EIT. We endeavor to inform future users of the benefits of this imaging modality and provide opportunities to further explore applications of this technology with regards to perfusion imaging and pathology diagnosis
Evolving and sustaining ocean best practices and standards for the next decade
The oceans play a key role in global issues such as climate change, food security, and human health. Given their vast dimensions and internal complexity, efficient monitoring and predicting of the planet’s ocean must be a collaborative effort of both regional and global scale. A first and foremost requirement for such collaborative ocean observing is the need to follow well-defined and reproducible methods across activities: from strategies for structuring observing systems, sensor deployment and usage, and the generation of data and information products, to ethical and governance aspects when executing ocean observing. To meet the urgent, planet-wide challenges we face, methods across all aspects of ocean observing should be broadly adopted by the ocean community and, where appropriate, should evolve into “Ocean Best Practices.” While many groups have created best practices, they are scattered across the Web or buried in local repositories and many have yet to be digitized. To reduce this fragmentation, we introduce a new open access, permanent, digital repository of best practices documentation (oceanbestpractices.org) that is part of the Ocean Best Practices System (OBPS). The new OBPS provides an opportunity space for the centralized and coordinated improvement of ocean observing methods. The OBPS repository employs user-friendly software to significantly improve discovery and access to methods. The software includes advanced semantic technologies for search capabilities to enhance repository operations. In addition to the repository, the OBPS also includes a peer reviewed journal research topic, a forum for community discussion and a training activity for use of best practices. Together, these components serve to realize a core objective of the OBPS, which is to enable the ocean community to create superior methods for every activity in ocean observing from research to operations to applications that are agreed upon and broadly adopted across communities. Using selected ocean observing examples, we show how the OBPS supports this objective. This paper lays out a future vision of ocean best practices and how OBPS will contribute to improving ocean observing in the decade to come
A transcriptome-based classifier to identify developmental toxicants by stem cell testing: design, validation and optimization for histone deacetylase inhibitors
Human embryonic stem cell-derived test systems for developmental neurotoxicity: a transcriptomics approach
Dance of the Starlings
In this birdwatching paper our binoculars are focused upon a particular bird from Smullyan’s enchanted forest of combinatory birds (Smullyan in To Mock a Mockingbird, and other logic puzzles. Alfred A. Knopf, New York, 1985), to wit the Starling. In the feathers of
λ
-calculus this bird has the plumage
λ
abc. ac(bc). This term is usually named S, reminiscent of its inventor Schönfinkel and also the combinatory ornithologist Smullyan. The combinator S is important for a variety of reasons. First, it is part of the {S,K}-basis for Combinatory Logic (CL). Second, there are several interesting questions and observations around S, mostly referring to termination and word problems. Our paper collects known facts, but poses in addition several new questions. For some of these we provide solutions, but several tough open questions remain