Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Symbolic Verification of Communication Protocols with Infinite State Spaces Using QDDs

peer reviewedWe study the verification of properties of communication protocols modeled by a finite set of finite-state machines that communicate by exchanging messages via unbounded FIFO queues. It is well-known that most interesting verification problems, such as deadlock detection, are undecidable for this class of systems. However, in practice, these verification problems may very well turn out to be decidable for a subclass containing most "real" protocols. Motivated by this optimistic (and, we claim, realistic) observation, we present an algorithm that may construct a finite and exact representation of the state space of a communication protocol, even if this state space is infinite. Our algorithm performs a loop-first search in the state space of the protocol being analyzed. A loop-first search is a search technique that attempts to explore first the results of successive executions of loops in the protocol description (code). A new data structure named Queue-content Decision Diagram (QDD) is introduced for representing (possibly infinite) sets of queue-contents. Operations for manipulating QDDs during a loop-first search are presented. A loop-first search using QDDs has been implemented, and experiments on several existing communication protocols with infinite state spaces have been performed. For these examples, our tool completed its search, and produced a finite symbolic representation for these infinite state spaces