Oracle Computability and Turing Reducibility in the Calculus of Inductive Constructions

We develop synthetic notions of oracle computability and Turing reducibility in the Calculus of Inductive Constructions (CIC), the constructive type theory underlying the Coq proof assistant. As usual in synthetic approaches, we employ a definition of oracle computations based on meta-level functions rather than object-level models of computation, relying on the fact that in constructive systems such as CIC all definable functions are computable by construction. Such an approach lends itself well to machine-checked proofs, which we carry out in Coq. There is a tension in finding a good synthetic rendering of the higher-order notion of oracle computability. On the one hand, it has to be informative enough to prove central results, ensuring that all notions are faithfully captured. On the other hand, it has to be restricted enough to benefit from axioms for synthetic computability, which usually concern first-order objects. Drawing inspiration from a definition by Andrej Bauer based on continuous functions in the effective topos, we use a notion of sequential continuity to characterise valid oracle computations. As main technical results, we show that Turing reducibility forms an upper semilattice, transports decidability, and is strictly more expressive than truth-table reducibility, and prove that whenever both a predicate $p$ and its complement are semi-decidable relative to an oracle $q$, then $p$ Turing-reduces to $q$

On the importance of risk knowledge for an end-to-end tsunami early warning system

Warning systems commonly use information provided by networks of sensors able to monitor and detect impending disasters, aggregate and condense these information to provide reliable information to a decision maker whether to warn or not, disseminates the warning message and provide this information to people at risk. Ultimate aim is to enable those in danger to make decisions (e.g. initiate protective actions for buildings) and to take action to safe their lives. This involves very complex issues when considering all four elements of early warning systems (UNISDR-PPEW), namely (1) risk knowledge, (2) monitoring and warning service, (3) dissemination and communication, (4) response capability with the ultimate aim to gain as much time as possible to empower individuals and communities to act in an appropriate manner to reduce injury, loss of life, damage to property and the environment and loss of livelihoods. Commonly most warning systems feature strengths and main attention on the technical/structural dimension (monitoring & warning service, dissemination tools) with weaknesses and less attention on social/cultural dimension (e.g. human response capabilities, defined warning chain to and knowing what to do by the people). Also, the use of risk knowledge in early warning most often is treated in a theoretical manner (knowing that it is somehow important), yet less in an operational, practical sense. Risk assessments and risk maps help to motivate people, prioritise early warning system needs and guide preparations for response and disaster prevention activities. Beyond this risk knowledge can be seen as a tie between national level early warning and community level reaction schemes. This presentation focuses on results, key findings and lessons-learnt related to tsunami risk assessment in the context of early warning within the GITEWS (German-Indonesian Tsunami Early Warning) project. Here a novel methodology reflecting risk information needs in the early warning context has been worked out. The generated results contribute significantly in the fields of (1) warning decision and warning levels, (2) warning dissemination and warning message content, (3) early warning chain planning, (4) increasing response capabilities and protective systems, (5) emergency relief and (6) enhancing communities’ awareness and preparedness towards tsunami threats. Additionally examples will be given on the potentials of an operational use of risk information in early warning systems as first experiences exist for the tsunami early warning center in Jakarta, Indonesia. Beside this the importance of linking national level early warning information with tsunami risk information available at the local level (e.g. linking warning message information on expected intensity with respective tsunami hazard zone maps at community level for effective evacuation) will be demonstrated through experiences gained in three pilot areas in Indonesia. The presentation seeks to provide new insights on benefits using risk information in early warning and will provide further evidence that practical use of risk information is an important and indispensable component of end-to-end early warning

Generating tsunami risk knowledge at community level as a base for planning and implementation of risk reduction strategies

More than 4 million Indonesians live in tsunami-prone areas along the southern and western coasts of Sumatra, Java and Bali. Although there now exists a Tsunami Early Warning Center in Jakarta, installed after the devastating 2004 tsunami, it is essential to develop tsunami risk knowledge within exposed communities as a basis for tsunami disaster management. Communities need to implement risk reduction strategies to mitigate potential consequences. The major aims of this paper are to present a risk assessment methodology which (1) identifies areas of high tsunami risk in terms of potential loss of life, (2) bridges the gaps between research and practical application, and (3) can be implemented at community level. High risk areas have a high need of action to improve people’s response capabilities towards a disaster and thus to reduce the risk. The methodology developed here is based on a GIS approach and combines hazard probability, hazard intensity, population density and people’s response capability to assess the risk. Within the framework of the GITEWS (German-Indonesian Tsunami Early Warning System) project, the methodology was applied to three pilot areas; one of which is southern Bali. Bali’s tourism is concentrated for a great part in the communities of Kuta, Legian and Seminyak. Here alone, about 20,000 people live in high and very high tsunami risk areas. The development of risk reduction strategies is therefore of significant interest. A risk map produced for the study area in Bali can be used for local planning activities and the development of risk reduction strategies

Light-Enabled Deracemization of Cyclopropanes by Al-Salen Photocatalysis

Privileged chiral catalysts continue to transform the reactivity landscape, but achieving parity in excited state paradigms remains a frontier in contemporary synthesis. Whilst the interception of photogenerated intermediates by ground state cycles has partially addressed this challenge, single, chiral photocatalysts that simultaneously regulate reactivity and selectivity remain conspicuously scarce. Existing strategies leverage precision donor-acceptor recognition motifs to orchestrate enantioinduction. Expanding the latitude of this emerging branch of photocatalysis to incorporate simple, ubiquitous recognition units would be highly enabling but requires a suite of privileged photocatalysts. Motivated by the well-defined photo-physical properties of chiral Al-salen complexes, the efficiency of this privileged catalyst has been investigated and validated in the highly enantioselective deracemization of cyclopropyl ketones (up to 98:2 e.r.)

A Coq Library for Mechanised First-Order Logic

International audienceWe report about an ongoing collaborative effort to consolidate several Coq developments concerning metamathematical results in first-order logic [1, 2, 11, 10, 8, 7, 6, 15, 12] into a single library. We first describe the framework regarding the representation of syntax, deduction systems, and semantics as well as its instantiation to axiom systems and tools for user-friendly interaction. Next, we summarise the included results mostly connected to completeness, undecidability, and incompleteness. Finally, we conclude by reporting on challenges experienced and anticipated during the integration. The current status of the project can be tracked in a public fork of the Coq Library of Undecidability Proofs [3]. Framework In principle, we follow ideas and suggestions present in various approaches [14, 9, 5, 4, 13] to the representation of first-order logic in CIC. Over the span of our initial projects we tried out several variants and found the final framework to be most suitable. Notably, a previous version used the Autosubst 2 tool [16] to generate the syntax, which we decided to avoid in later versions due to its use of function extensionality. The final framework, however, still follows the same design principles for binding and substitution. The syntax is represented by inductive types for terms t : T and formulas ϕ : F depending on signatures of function symbols f and relation symbols P as well as a collection of binary connectives 2 and quantifiers ∇

Tsunami risk assessment for local communities in Indonesia to provide information for early warning and disaster management

Decision makers at the community level need detailed information on tsunami risk in their area. Knowledge on potential hazard impact, exposed elements such as people, critical facilities and lifelines, coping capacity and recovery is crucial to plan precautionary measures to mitigate potential impacts of tsunamis on society and the environment. In this study a community level risk assessment methodology is presented. Thereby the risk assessment encompasses and discloses weaknesses within the components exposure, susceptibility, response and recovery potential at the community level. This means that detailed information is generated on dynamic exposure factors (e.g. day and night distribution of exposed people, location and properties of critical facilities), people ability to respond and evacuate potential damage on the built environment, local emergency response capability and local ability for rehabilitation and recovery. To quantify these risk components detailed surveys have been conducted to collect the necessary information. Based on these data on socio-economic household properties, critical facilities locations, building damage potential, potential vertical and horizontal evacuation areas and their properties an in-depth risk assessment has been conducted. The study presents first results of studies which have been performed in several pilot areas in Indonesia. They are based on common developed methodologies at the community level. The results and products can be used for tsunami disaster adaptation and mitigation planning, but also to improve people and institutional preparedness and awareness. General guidelines on how to conduct the assessment are being developed and shall be incorporated into community level disaster management strategies

DPPN-Root and DPPN-shoot: Plant phenotyping infrastructure as an instrumental tool in the assessment of plant performance in the frame of crop breeding for resource use efficiency

The controlled conditions phenotyping infrastructure of the DPPN-Jülich node provides established facilities for experimental research, while being under continuous development and expansion. Besides excellent phenotyping platform hardware and software, and in-house developed data analysis pipelines, experience in good phenotyping practices, including the collection and management of metadata on plants and their environment, and making the best use of platforms in regard to the biological question being addressed, is a major driver for both public and private sector research to access the phenotyping infrastructure also in the form of bilateral cooperative projects. The plant species grown in the platforms include a wide range of model and crop species, for which phenotypic traits on growth, development and physiological behaviour are quantitatively measured. Automated and high-throughput trait assessment at both the shoot and root system, and the organ level is complemented with the measurement of shoot and root biomass, transpiration and photosynthesis, and individual organ growth and morphology, to provide a comprehensive evaluation of the plant phenotype with respect to the imposed environmental conditions.The DPPN-Jülich node has put its infrastructure into practice by providing much-needed capacity for solving pertinent research questions related to plant performance in breeding strategies for resource-limited environments. In the case of wheat, the effect of domestication on the phenotypic diversity of the germplasm was investigated under contrasting nitrogen conditions (Gioia et al. 2015), whereas its water use strategies under control and drought conditions were determined and compared between landraces and modern cultivars (Nakhforoosh et al. 2016). Shoot and root system responses to drought were characterized at the seedling stage of development in maize hybrids with known drought tolerance states under field conditions in an attempt to determine seedling stage traits relevant for early screening for drought tolerance (Avramova et al. 2016). These examples of access in the form of bilateral cooperative projects that have led to peer-reviewed scientific publications therefore demonstrate the importance of plant phenotyping infrastructure and know-how.LiteratureGioia T., Nagel K.A., Beleggia R. et al. (2015). The impact of domestication on the phenotypic architecture of durum wheat under contrasting nitrogen fertilisation. Journal of Experimental Botany 66, 5519-5530. Avramova V., Nagel K.A., AbdElgawad H., Bustos D., DuPlessis M., Fiorani F., Beemster G.T.S. (2016) Screening for drought tolerance of maize hybrids by multi-scale analysis of root and shoot traits at the seedling stage. Journal of Experimental Botany 67, 2453-2466. Nakhforoosh A., Bodewein T., Fiorani F., Gernot Bodner (2016). Identification of water use strategies at early growth stages in durum wheat from shoot phenotyping and physiological measurements. Frontiers in Plant Science 7, 1155