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Showing papers by "University of Konstanz published in 2018"


Journal ArticleDOI
Marlee A. Tucker1, Katrin Böhning-Gaese1, William F. Fagan2, John M. Fryxell3, Bram Van Moorter, Susan C. Alberts4, Abdullahi H. Ali, Andrew M. Allen5, Andrew M. Allen6, Nina Attias7, Tal Avgar8, Hattie L. A. Bartlam-Brooks9, Buuveibaatar Bayarbaatar10, Jerrold L. Belant11, Alessandra Bertassoni12, Dean E. Beyer13, Laura R. Bidner14, Floris M. van Beest15, Stephen Blake16, Stephen Blake10, Niels Blaum17, Chloe Bracis1, Danielle D. Brown18, P J Nico de Bruyn19, Francesca Cagnacci20, Francesca Cagnacci21, Justin M. Calabrese22, Justin M. Calabrese2, Constança Camilo-Alves23, Simon Chamaillé-Jammes24, André Chiaradia25, André Chiaradia26, Sarah C. Davidson27, Sarah C. Davidson16, Todd E. Dennis28, Stephen DeStefano29, Duane R. Diefenbach30, Iain Douglas-Hamilton31, Iain Douglas-Hamilton32, Julian Fennessy, Claudia Fichtel33, Wolfgang Fiedler16, Christina Fischer34, Ilya R. Fischhoff35, Christen H. Fleming2, Christen H. Fleming22, Adam T. Ford36, Susanne A. Fritz1, Benedikt Gehr37, Jacob R. Goheen38, Eliezer Gurarie39, Eliezer Gurarie2, Mark Hebblewhite40, Marco Heurich41, Marco Heurich42, A. J. Mark Hewison43, Christian Hof, Edward Hurme2, Lynne A. Isbell14, René Janssen, Florian Jeltsch17, Petra Kaczensky44, Adam Kane45, Peter M. Kappeler33, Matthew J. Kauffman38, Roland Kays46, Roland Kays47, Duncan M. Kimuyu48, Flávia Koch33, Flávia Koch49, Bart Kranstauber37, Scott D. LaPoint50, Scott D. LaPoint16, Peter Leimgruber22, John D. C. Linnell, Pascual López-López51, A. Catherine Markham52, Jenny Mattisson, Emília Patrícia Medici53, Ugo Mellone54, Evelyn H. Merrill8, Guilherme Miranda de Mourão55, Ronaldo Gonçalves Morato, Nicolas Morellet43, Thomas A. Morrison56, Samuel L. Díaz-Muñoz57, Samuel L. Díaz-Muñoz14, Atle Mysterud58, Dejid Nandintsetseg1, Ran Nathan59, Aidin Niamir, John Odden, Robert B. O'Hara60, Luiz Gustavo R. Oliveira-Santos7, Kirk A. Olson10, Bruce D. Patterson61, Rogério Cunha de Paula, Luca Pedrotti, Björn Reineking62, Björn Reineking63, Martin Rimmler, Tracey L. Rogers64, Christer Moe Rolandsen, Christopher S. Rosenberry65, Daniel I. Rubenstein66, Kamran Safi67, Kamran Safi16, Sonia Saïd, Nir Sapir68, Hall Sawyer, Niels Martin Schmidt15, Nuria Selva69, Agnieszka Sergiel69, Enkhtuvshin Shiilegdamba10, João P. Silva70, João P. Silva71, João P. Silva72, Navinder J. Singh5, Erling Johan Solberg, Orr Spiegel14, Olav Strand, Siva R. Sundaresan, Wiebke Ullmann17, Ulrich Voigt44, Jake Wall32, David W. Wattles29, Martin Wikelski16, Martin Wikelski67, Christopher C. Wilmers73, John W. Wilson74, George Wittemyer75, George Wittemyer32, Filip Zięba, Tomasz Zwijacz-Kozica, Thomas Mueller22, Thomas Mueller1 
Goethe University Frankfurt1, University of Maryland, College Park2, University of Guelph3, Duke University4, Swedish University of Agricultural Sciences5, Radboud University Nijmegen6, Federal University of Mato Grosso do Sul7, University of Alberta8, Royal Veterinary College9, Wildlife Conservation Society10, Mississippi State University11, Sao Paulo State University12, Michigan Department of Natural Resources13, University of California, Davis14, Aarhus University15, Max Planck Society16, University of Potsdam17, Middle Tennessee State University18, Mammal Research Institute19, Harvard University20, Edmund Mach Foundation21, Smithsonian Conservation Biology Institute22, University of Évora23, University of Montpellier24, Parks Victoria25, Monash University26, Ohio State University27, Fiji National University28, University of Massachusetts Amherst29, United States Geological Survey30, University of Oxford31, Save the Elephants32, German Primate Center33, Technische Universität München34, Institute of Ecosystem Studies35, University of British Columbia36, University of Zurich37, University of Wyoming38, University of Washington39, University of Montana40, University of Freiburg41, Bavarian Forest National Park42, University of Toulouse43, University of Veterinary Medicine Vienna44, University College Cork45, North Carolina Museum of Natural Sciences46, North Carolina State University47, Karatina University48, University of Lethbridge49, Lamont–Doherty Earth Observatory50, University of Valencia51, Stony Brook University52, International Union for Conservation of Nature and Natural Resources53, University of Alicante54, Empresa Brasileira de Pesquisa Agropecuária55, University of Glasgow56, New York University57, University of Oslo58, Hebrew University of Jerusalem59, Norwegian University of Science and Technology60, Field Museum of Natural History61, University of Grenoble62, University of Bayreuth63, University of New South Wales64, Pennsylvania Game Commission65, Princeton University66, University of Konstanz67, University of Haifa68, Polish Academy of Sciences69, University of Lisbon70, Instituto Superior de Agronomia71, University of Porto72, University of California, Santa Cruz73, University of Pretoria74, Colorado State University75
26 Jan 2018-Science
TL;DR: Using a unique GPS-tracking database of 803 individuals across 57 species, it is found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in area with a low human footprint.
Abstract: Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission.

719 citations


Journal ArticleDOI
TL;DR: This work shows how content-aware image restoration based on deep learning extends the range of biological phenomena observable by microscopy by bypassing the trade-offs between imaging speed, resolution, and maximal light exposure that limit fluorescence imaging to enable discovery.
Abstract: Fluorescence microscopy is a key driver of discoveries in the life sciences, with observable phenomena being limited by the optics of the microscope, the chemistry of the fluorophores, and the maximum photon exposure tolerated by the sample. These limits necessitate trade-offs between imaging speed, spatial resolution, light exposure, and imaging depth. In this work we show how content-aware image restoration based on deep learning extends the range of biological phenomena observable by microscopy. We demonstrate on eight concrete examples how microscopy images can be restored even if 60-fold fewer photons are used during acquisition, how near isotropic resolution can be achieved with up to tenfold under-sampling along the axial direction, and how tubular and granular structures smaller than the diffraction limit can be resolved at 20-times-higher frame rates compared to state-of-the-art methods. All developed image restoration methods are freely available as open source software in Python, FIJI, and KNIME. Content-aware image restoration (CARE) uses deep learning to improve microscopy images. CARE bypasses the trade-offs between imaging speed, resolution, and maximal light exposure that limit fluorescence imaging to enable discovery.

694 citations


Journal ArticleDOI
TL;DR: In this article, the authors describe the main ideas, recent developments and progress in a broad spectrum of research investigating ML and AI in the quantum domain, and discuss the fundamental issue of quantum generalizations of learning and AI concepts.
Abstract: Quantum information technologies, on the one hand, and intelligent learning systems, on the other, are both emergent technologies that are likely to have a transformative impact on our society in the future. The respective underlying fields of basic research-quantum information versus machine learning (ML) and artificial intelligence (AI)-have their own specific questions and challenges, which have hitherto been investigated largely independently. However, in a growing body of recent work, researchers have been probing the question of the extent to which these fields can indeed learn and benefit from each other. Quantum ML explores the interaction between quantum computing and ML, investigating how results and techniques from one field can be used to solve the problems of the other. Recently we have witnessed significant breakthroughs in both directions of influence. For instance, quantum computing is finding a vital application in providing speed-ups for ML problems, critical in our 'big data' world. Conversely, ML already permeates many cutting-edge technologies and may become instrumental in advanced quantum technologies. Aside from quantum speed-up in data analysis, or classical ML optimization used in quantum experiments, quantum enhancements have also been (theoretically) demonstrated for interactive learning tasks, highlighting the potential of quantum-enhanced learning agents. Finally, works exploring the use of AI for the very design of quantum experiments and for performing parts of genuine research autonomously, have reported their first successes. Beyond the topics of mutual enhancement-exploring what ML/AI can do for quantum physics and vice versa-researchers have also broached the fundamental issue of quantum generalizations of learning and AI concepts. This deals with questions of the very meaning of learning and intelligence in a world that is fully described by quantum mechanics. In this review, we describe the main ideas, recent developments and progress in a broad spectrum of research investigating ML and AI in the quantum domain.

684 citations


Journal ArticleDOI
26 Jan 2018-Science
TL;DR: An efficient resonantly driven CNOT gate for electron spins in silicon is demonstrated and used to create an entangled quantum state called the Bell state with 78% fidelity, which enables multi-qubit algorithms in silicon.
Abstract: Single-qubit rotations and two-qubit CNOT operations are crucial ingredients for universal quantum computing. Although high-fidelity single-qubit operations have been achieved using the electron spin degree of freedom, realizing a robust CNOT gate has been challenging because of rapid nuclear spin dephasing and charge noise. We demonstrate an efficient resonantly driven CNOT gate for electron spins in silicon. Our platform achieves single-qubit rotations with fidelities greater than 99%, as verified by randomized benchmarking. Gate control of the exchange coupling allows a quantum CNOT gate to be implemented with resonant driving in ~200 nanoseconds. We used the CNOT gate to generate a Bell state with 78% fidelity (corrected for errors in state preparation and measurement). Our quantum dot device architecture enables multi-qubit algorithms in silicon.

569 citations


Journal ArticleDOI
14 Feb 2018-Nature
TL;DR: Strong coupling between a single spin in silicon and a single microwave-frequency photon, with spin–photon coupling rates of more than 10 megahertz is demonstrated, which opens up a direct path to entangling single spins using microwave- frequencies.
Abstract: Electron spins in silicon quantum dots are attractive systems for quantum computing owing to their long coherence times and the promise of rapid scaling of the number of dots in a system using semiconductor fabrication techniques. Although nearest-neighbour exchange coupling of two spins has been demonstrated, the interaction of spins via microwave-frequency photons could enable long-distance spin–spin coupling and connections between arbitrary pairs of qubits (‘all-to-all’ connectivity) in a spin-based quantum processor. Realizing coherent spin–photon coupling is challenging because of the small magnetic-dipole moment of a single spin, which limits magnetic-dipole coupling rates to less than 1 kilohertz. Here we demonstrate strong coupling between a single spin in silicon and a single microwave-frequency photon, with spin–photon coupling rates of more than 10 megahertz. The mechanism that enables the coherent spin–photon interactions is based on spin–charge hybridization in the presence of a magnetic-field gradient. In addition to spin–photon coupling, we demonstrate coherent control and dispersive readout of a single spin. These results open up a direct path to entangling single spins using microwave-frequency photons. A single spin in silicon is strongly coupled to a microwave-frequency photon and coherent single-spin dynamics are observed using circuit quantum electrodynamics. Solid-state spins are promising qubits for quantum information processing thanks to their long coherence times, but harnessing spin–spin interactions is still a challenge. Spin–spin coupling is currently based on the exchange interaction and the weaker dipole–dipole interaction. Strong spin–photon coupling, achieved through coherent spin–photon interactions, could enable long-distance spin entanglement mediated by microwave photons. Here, Jason Petta and colleagues demonstrate a spin–photon interface where a single electron spin in a silicon double quantum dot is strongly coupled to a photon trapped in a microwave cavity. The technique, which relies on spin–charge hybridization in the presence of an inhomogeneous magnetic field, generates spin–photon coupling rates that ensure the coherence of the interface. The authors demonstrate all-electric control of the spin–photon coupling, as well as coherent manipulation of the spin state and dispersive readout of the single electron spin. These results suggest that a spin-based quantum processor might be one step closer.

414 citations


Journal ArticleDOI
TL;DR: Using a global database of the first regional records of alien species covering the years 1500–2005, a surprisingly high proportion of species in recent records that have never been recorded as alien before are detected.
Abstract: Our ability to predict the identity of future invasive alien species is largely based upon knowledge of prior invasion history Emerging alien species—those never encountered as aliens before—therefore pose a significant challenge to biosecurity interventions worldwide Understanding their temporal trends, origins, and the drivers of their spread is pivotal to improving prevention and risk assessment tools Here, we use a database of 45,984 first records of 16,019 established alien species to investigate the temporal dynamics of occurrences of emerging alien species worldwide Even after many centuries of invasions the rate of emergence of new alien species is still high: One-quarter of first records during 2000–2005 were of species that had not been previously recorded anywhere as alien, though with large variation across taxa Model results show that the high proportion of emerging alien species cannot be solely explained by increases in well-known drivers such as the amount of imported commodities from historically important source regions Instead, these dynamics reflect the incorporation of new regions into the pool of potential alien species, likely as a consequence of expanding trade networks and environmental change This process compensates for the depletion of the historically important source species pool through successive invasions We estimate that 1–16% of all species on Earth, depending on the taxonomic group, qualify as potential alien species These results suggest that there remains a high proportion of emerging alien species we have yet to encounter, with future impacts that are difficult to predict

382 citations


Journal ArticleDOI
TL;DR: An autonomous learning model is presented which learns to design complex photonic quantum experiments that produce high-dimensional entangled multiphoton states, which are of high interest in modern quantum experiments and improves the efficiency of their realization.
Abstract: How useful can machine learning be in a quantum laboratory? Here we raise the question of the potential of intelligent machines in the context of scientific research. A major motivation for the present work is the unknown reachability of various entanglement classes in quantum experiments. We investigate this question by using the projective simulation model, a physics-oriented approach to artificial intelligence. In our approach, the projective simulation system is challenged to design complex photonic quantum experiments that produce high-dimensional entangled multiphoton states, which are of high interest in modern quantum experiments. The artificial intelligence system learns to create a variety of entangled states and improves the efficiency of their realization. In the process, the system autonomously (re)discovers experimental techniques which are only now becoming standard in modern quantum optical experiments—a trait which was not explicitly demanded from the system but emerged through the process of learning. Such features highlight the possibility that machines could have a significantly more creative role in future research.

298 citations


Posted ContentDOI
23 Jan 2018-bioRxiv
TL;DR: This work shows how deep learning enables biological observations beyond the physical limitations of microscopes, and illustrates how microscopy images can be restored even if 60-fold fewer photons are used during acquisition.
Abstract: Fluorescence microscopy is a key driver of discoveries in the life-sciences, with observable phenomena being limited by the optics of the microscope, the chemistry of the fluorophores, and the maximum photon exposure tolerated by the sample. These limits necessitate trade-offs between imaging speed, spatial resolution, light exposure, and imaging depth. In this work we show how deep learning enables biological observations beyond the physical limitations of microscopes. On seven concrete examples we illustrate how microscopy images can be restored even if 60-fold fewer photons are used during acquisition, how isotropic resolution can be achieved even with a 10-fold under-sampling along the axial direction, and how diffraction-limited structures can be resolved at 20-times higher frame-rates compared to state-of-the-art methods. All developed image restoration methods are freely available as open source software.

254 citations


Journal ArticleDOI
TL;DR: The authors integrate research on child simultaneous bilingual (2L1) acquisition more directly into the heritage language acquisition literature and offer an epistemological discussion related to incomplete acquisition, highlighting the descriptive and theoretical inaccuracy of the term.
Abstract: This paper integrates research on child simultaneous bilingual (2L1) acquisition more directly into the heritage language (HL) acquisition literature. The 2L1 literature mostly focuses on development in childhood, whereas heritage speakers (HSs) are often tested at an endstate in adulthood. However, insights from child 2L1 acquisition must be considered in HL acquisition theorizing precisely because many HSs are the adult outcomes of child 2L1 acquisition. Data from 2L1 acquisition raises serious questions for the construct of incomplete acquisition, a term broadly used in HL acquisition studies to describe almost any difference HSs display from baseline controls (usually monolinguals). We offer an epistemological discussion related to incomplete acquisition, highlighting the descriptive and theoretical inaccuracy of the term. We focus our discussion on two of several possible causal factors that contribute to variable competence outcomes in adult HSs, input (e.g., Sorace, 2004; Rothman, 2007; Pascual y Cabo & Rothman, 2012) and formal instruction (e.g., Kupisch, 2013; Kupisch et al., 2014) in the HL. We conclude by offering alternative terminology for HS outcomes.

234 citations


Journal ArticleDOI
TL;DR: An overview of the historical, contemporary and potential future roles of ornamental horticulture in plant invasions is provided, showing that currently at least 75% and 93% of the global naturalised alien flora is grown in domestic and botanical gardens, respectively.
Abstract: The number of alien plants escaping from cultivation into native ecosystems is increasing steadily. We provide an overview of the historical, contemporary and potential future roles of ornamental horticulture in plant invasions. We show that currently at least 75% and 93% of the global naturalised alien flora is grown in domestic and botanical gardens, respectively. Species grown in gardens also have a larger naturalised range than those that are not. After the Middle Ages, particularly in the 18th and 19th centuries, a global trade network in plants emerged. Since then, cultivated alien species also started to appear in the wild more frequently than non-cultivated aliens globally, particularly during the 19th century. Horticulture still plays a prominent role in current plant introduction, and the monetary value of live-plant imports in different parts of the world is steadily increasing. Historically, botanical gardens – an important component of horticulture – played a major role in displaying, cultivating and distributing new plant discoveries. While the role of botanical gardens in the horticultural supply chain has declined, they are still a significant link, with one-third of institutions involved in retail-plant sales and horticultural research. However, botanical gardens have also become more dependent on commercial nurseries as plant sources, particularly in North America. Plants selected for ornamental purposes are not a random selection of the global flora, and some of the plant characteristics promoted through horticulture, such as fast growth, also promote invasion. Efforts to breed non-invasive plant cultivars are still rare. Socio-economical, technological, and environmental changes will lead to novel patterns of plant introductions and invasion opportunities for the species that are already cultivated. We describe the role that horticulture could play in mediating these changes. We identify current research challenges, and call for more research efforts on the past and current role of horticulture in plant invasions. This is required to develop science-based regulatory frameworks to prevent further plant invasions.

222 citations


Journal ArticleDOI
19 Jan 2018-PLOS ONE
TL;DR: Findings suggest that for adults, convincing evidence supports a relationship between PA and socioeconomic status (SES), especially in relation to leisure time (positive relationship) and occupational PA (negative relationship).
Abstract: Background To date, the scientific literature on socioeconomic correlates and determinants of physical activity behaviours has been dispersed throughout a number of systematic reviews, often focusing on one factor (eg education or parental income) in one specific age group (eg pre-school children or adults) The aim of this umbrella review is to provide a comprehensive and systematic overview of the scientific literature from previously conducted research by summarising and synthesising the importance and strength of the evidence related to socioeconomic correlates and determinants of PA behaviours across the life course Methods Medline, Embase, ISI Web of Science, Scopus and SPORTDiscus were searched for systematic literature reviews and meta-analyses of observational studies investigating the association between socioeconomic determinants of PA and PA itself (from January 2004 to September 2017) Data extraction evaluated the importance of determinants, strength of evidence, and methodological quality of the selected papers The full protocol is available from PROSPERO (PROSPERO2014:CRD42015010616) Results Nineteen reviews were included Moderate methodological quality emerged For adults, convincing evidence supports a relationship between PA and socioeconomic status (SES), especially in relation to leisure time (positive relationship) and occupational PA (negative relationship) Conversely, no association between PA and SES or parental SES was found for pre-school, school-aged children and adolescents Conclusions Available evidence on the socioeconomic determinants of PA behaviour across the life course is probable (shows fairly consistent associations) at best While some evidence is available for adults, less was available for youth This is mainly due to a limited quantity of primary studies, weak research designs and lack of accuracy in the PA and SES assessment methods employed Further PA domain specific studies using longitudinal design and clear measures of SES and PA assessment are required

Journal ArticleDOI
TL;DR: A chemical hazard database via natural language processing of dossiers submitted to the European Chemical Agency with approximately 10 000 chemicals was created, identifying repeat OECD guideline tests to establish reproducibility of acute oral and dermal toxicity, eye and skin irritation, mutagenicity and skin sensitization.

Journal ArticleDOI
TL;DR: In this article, the authors present a preclinical and clinical action plan for the repurposing of PARP inhibitors for non-oncological indications, such as acute ischaemic stroke, traumatic brain injury, septic shock, acute pancreatitis, severe asthma and severe acute lung injury.
Abstract: The recent clinical availability of the PARP inhibitor olaparib (Lynparza) opens the door for potential therapeutic repurposing for non-oncological indications. Considering (a) the preclinical efficacy data with PARP inhibitors in non-oncological diseases and (b) the risk-benefit ratio of treating patients with a compound that inhibits an enzyme that has physiological roles in the regulation of DNA repair, we have selected indications, where (a) the severity of the disease is high, (b) the available therapeutic options are limited, and (c) the duration of PARP inhibitor administration could be short, to provide first-line options for therapeutic repurposing. These indications are as follows: acute ischaemic stroke; traumatic brain injury; septic shock; acute pancreatitis; and severe asthma and severe acute lung injury. In addition, chronic, devastating diseases, where alternative therapeutic options cannot halt disease development (e.g. Parkinson's disease, progressive multiple sclerosis or severe fibrotic diseases), should also be considered. We present a preclinical and clinical action plan for the repurposing of PARP inhibitors. This article is part of a themed section on Inventing New Therapies Without Reinventing the Wheel: The Power of Drug Repurposing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.2/issuetoc.

Journal ArticleDOI
TL;DR: This review discusses how adhesion proteins and the T cell receptor act as mechanosensors to translate mechanical contexts into signaling events and how cell tension could bring a significant contribution to the regulation of T cell signaling and function.
Abstract: T cell migration from blood to, and within lymphoid organs and tissue, as well as, T cell activation rely on complex biochemical signaling events. But T cell migration and activation also take place in distinct mechanical environments and lead to drastic morphological changes and reorganization of the acto-myosin cytoskeleton. In this review we discuss how adhesion proteins and the T cell receptor act as mechanosensors to translate these mechanical contexts into signaling events. We further discuss how cell tension could bring a significant contribution to the regulation of T cell signaling and function.

Journal ArticleDOI
TL;DR: The deep phylogenetic structure of the Lake Tanganyika radiation is disentangled using anchored phylogenomics and hybridization at its base is uncovered, as well as early in the haplochromine radiation, suggesting that hybridization might have facilitated these speciation bursts.
Abstract: Lake Tanganyika is the oldest and phenotypically most diverse of the three East African cichlid fish adaptive radiations. It is also the cradle for the younger parallel haplochromine cichlid radiations in Lakes Malawi and Victoria. Despite its evolutionary significance, the relationships among the main Lake Tanganyika lineages remained unresolved, as did the general timescale of cichlid evolution. Here, we disentangle the deep phylogenetic structure of the Lake Tanganyika radiation using anchored phylogenomics and uncover hybridization at its base, as well as early in the haplochromine radiation. This suggests that hybridization might have facilitated these speciation bursts. Time-calibrated trees support that the radiation of Tanganyika cichlids coincided with lake formation and that Gondwanan vicariance concurred with the earliest splits in the cichlid family tree. Genes linked to key innovations show signals of introgression or positive selection following colonization of lake habitats and species’ dietary adaptations are revealed as major drivers of colour vision evolution. These findings shed light onto the processes shaping the evolution of adaptive radiations. Lake Tanganyika’s cichlid radiation is the main source of East African cichlid diversity. Irisarri et al. resolve its phylogenetic backbone using anchored phylogenomics and identify trans-lineage hybridization prior to major speciation bursts and adaptive loci underlying ecological innovations.

Journal ArticleDOI
13 Apr 2018-Toxins
TL;DR: Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota, and a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability.
Abstract: Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.


Journal ArticleDOI
TL;DR: Suggestions are made on how DNT NAMs may be assembled into an integrated approach to testing and assessment (IATA), and a vision is presented on how further NAM development may be guided by knowledge of signaling pathways necessary for brain development, DNT pathophysiology, and relevant adverse outcome pathways (AOP).
Abstract: Multiple non-animal-based test methods have never been formally validated. In order to use such new approach methods (NAMs) in a regulatory context, criteria to define their readiness are necessary. The field of developmental neurotoxicity (DNT) testing is used to exemplify the application of readiness criteria. The costs and number of untested chemicals are overwhelming for in vivo DNT testing. Thus, there is a need for inexpensive, high-throughput NAMs, to obtain initial information on potential hazards, and to allow prioritization for further testing. A background on the regulatory and scientific status of DNT testing is provided showing different types of test readiness levels, depending on the intended use of data from NAMs. Readiness criteria, compiled during a stakeholder workshop, uniting scientists from academia, industry and regulatory authorities are presented. An important step beyond the listing of criteria, was the suggestion for a preliminary scoring scheme. On this basis a (semi)-quantitative analysis process was assembled on test readiness of 17 NAMs with respect to various uses (e.g. prioritization/screening, risk assessment). The scoring results suggest that several assays are currently at high readiness levels. Therefore, suggestions are made on how DNT NAMs may be assembled into an integrated approach to testing and assessment (IATA). In parallel, the testing state in these assays was compiled for more than 1000 compounds. Finally, a vision is presented on how further NAM development may be guided by knowledge of signaling pathways necessary for brain development, DNT pathophysiology, and relevant adverse outcome pathways (AOP).

Journal ArticleDOI
TL;DR: A review of the state of the art of alien plant research with emphasis on conceptual advances and knowledge gains on general patterns and drivers, biotic interactions, and evolution is given in this paper.
Abstract: We review the state of the art of alien plant research with emphasis on conceptual advances and knowledge gains on general patterns and drivers, biotic interactions, and evolution. Major advances i...

Journal ArticleDOI
TL;DR: A new set of 750 colored pictures of concrete concepts, MultiPic, constitutes a new valuable tool for cognitive scientists investigating language, visual perception, memory and/or attention in monolingual or multilingual populations.
Abstract: Numerous studies in psychology, cognitive neuroscience and psycholinguistics have used pictures of objects as stimulus materials. Currently, authors engaged in cross-linguistic work or wishing to run parallel studies at multiple sites where different languages are spoken must rely on rather small sets of black-and-white or colored line drawings. These sets are increasingly experienced as being too limited. Therefore, we constructed a new set of 750 colored pictures of concrete concepts. This set, MultiPic, constitutes a new valuable tool for cognitive scientists investigating language, visual perception, memory and/or attention in monolingual or multilingual populations. Importantly, the MultiPic databank has been normed in six different European languages (British English, Spanish, French, Dutch, Italian and German). All stimuli and norms are freely available at http://www.bcbl.eu/databases/multipic

Journal ArticleDOI
TL;DR: In this paper, a set of classification criteria that are widely applicable across taxa and realms and offer guidance on their use in practice is provided. But the criteria focus on acknowledging the role of assessment uncertainty, incorporating time since introduction, considering infraspecific taxonomic ranks, and differentiating between alien species whose survival depends on explicit human assistance from those that survive without such assistance.
Abstract: Human activities such as the transport of species to new regions and modifications of the environment are increasingly reshaping the distribution of biota. Accordingly, developing robust, repeatable, and consistent definitions of alien species that serve scientific and policy purposes has become of prime importance. We provide a set of classification criteria that are widely applicable across taxa and realms and offer guidance on their use in practice. The criteria focus on (a) acknowledging the role of assessment uncertainty, (b) incorporating time since introduction, (c) considering infraspecific taxonomic ranks, and (d) differentiating between alien species whose survival depends on explicit human assistance from those that survive without such assistance. Furthermore, we make recommendations for reducing assessment uncertainty, suggest thresholds for species assessment, and develop an assessment scheme. We illustrate the application of the assessment criteria with case studies. Finally, the implications for alien species management, policy, and research are discussed.

Journal ArticleDOI
TL;DR: This survey attempts to report, categorize and unify the diverse understandings and aims to establish a common vocabulary that will enable a wide audience to understand their differences and subtleties.
Abstract: The visualization community has developed to date many intuitions and understandings of how to judge the quality of views in visualizing data. The computation of a visualization's quality and usefulness ranges from measuring clutter and overlap, up to the existence and perception of specific (visual) patterns. This survey attempts to report, categorize and unify the diverse understandings and aims to establish a common vocabulary that will enable a wide audience to understand their differences and subtleties. For this purpose, we present a commonly applicable quality metric formalization that should detail and relate all constituting parts of a quality metric. We organize our corpus of reviewed research papers along the data types established in the information visualization community: multi‐ and high‐dimensional, relational, sequential, geospatial and text data. For each data type, we select the visualization subdomains in which quality metrics are an active research field and report their findings, reason on the underlying concepts, describe goals and outline the constraints and requirements. One central goal of this survey is to provide guidance on future research opportunities for the field and outline how different visualization communities could benefit from each other by applying or transferring knowledge to their respective subdomain. Additionally, we aim to motivate the visualization community to compare computed measures to the perception of humans.

Journal ArticleDOI
TL;DR: A novel type of oyster-inspired organic-inorganic adhesive based on a biomineralized polyelectrolyte hydrogel is reported, which consists of polyacrylic acid physically cross-linked by very small amorphous calcium carbonate nanoparticles (<3 nm).
Abstract: Underwater adhesion is crucial to many marine life forms living a sedentary lifestyle. Amongst them, mussel adhesion has been mostly studied, which inspires numerous investigations of 3,4-dihydroxyphenylalanine (DOPA)-based organic adhesives. In contrast, reef-building oysters represent another important “inorganic” strategy of marine molluscs for adhesion by generating biomineralized organic–inorganic adhesives, which is still rarely studied and no synthetic analogues have ever been reported so far. Here, a novel type of oyster-inspired organic–inorganic adhesive based on a biomineralized polyelectrolyte hydrogel is reported, which consists of polyacrylic acid physically cross-linked by very small amorphous calcium carbonate nanoparticles (<3 nm). The mineral-enhanced polyelectrolyte hydrogel adhesive is shown to be injectable, reusable, and optically clear upon curing in air. Moreover, comparable adhesion performance to DOPA-based adhesives is found for the hydrogel adhesive in both dry and wet conditio...

Journal ArticleDOI
TL;DR: This work experimentally and numerically demonstrates how variations of a density-dependent particle response affect their self-organisation using a suspension of light-activated active particles whose motility is individually controlled by an external feedback-loop, realised by a particle detection algorithm and a scanning laser system.
Abstract: Many microorganisms regulate their behaviour according to the density of neighbours. Such quorum sensing is important for the communication and organisation within bacterial populations. In contrast to living systems, where quorum sensing is determined by biochemical processes, the behaviour of synthetic active particles can be controlled by external fields. Accordingly they allow to investigate how variations of a density-dependent particle response affect their self-organisation. Here we experimentally and numerically demonstrate this concept using a suspension of light-activated active particles whose motility is individually controlled by an external feedback-loop, realised by a particle detection algorithm and a scanning laser system. Depending on how the particles’ motility varies with the density of neighbours, the system self-organises into aggregates with different size, density and shape. Since the individual particles’ response to their environment is almost freely programmable, this allows for detailed insights on how communication between motile particles affects their collective properties. Bacteria communicate and organize via quorum sensing which is determined by biochemical processes. Here the authors aim to reproduce this behaviour in a system of synthetic active particles whose motion is induced by an external beam which is in turn controlled by a feedback-loop which mimics quorum sensing.

Journal ArticleDOI
26 Oct 2018-Science
TL;DR: How a single gene affects the convergent evolution of a complex color pattern is unveiled, finding that regulatory changes of the gene agouti-related peptide 2 (agrp2) act as molecular switches controlling this evolutionarily labile phenotype.
Abstract: The color patterns of African cichlid fishes provide notable examples of phenotypic convergence. Across the more than 1200 East African rift lake species, melanic horizontal stripes have evolved numerous times. We discovered that regulatory changes of the gene agouti-related peptide 2 (agrp2) act as molecular switches controlling this evolutionarily labile phenotype. Reduced agrp2 expression is convergently associated with the presence of stripe patterns across species flocks. However, cis-regulatory mutations are not predictive of stripes across radiations, suggesting independent regulatory mechanisms. Genetic mapping confirms the link between the agrp2 locus and stripe patterns. The crucial role of agrp2 is further supported by a CRISPR-Cas9 knockout that reconstitutes stripes in a nonstriped cichlid. Thus, we unveil how a single gene affects the convergent evolution of a complex color pattern.

Journal ArticleDOI
TL;DR: This work proposes a visual analytics system that tightly integrates team sport video recordings with abstract visualization of underlying trajectory data, and applies appropriate computer vision techniques to extract trajectory data from video input.
Abstract: Analysts in professional team sport regularly perform analysis to gain strategic and tactical insights into player and team behavior. Goals of team sport analysis regularly include identification of weaknesses of opposing teams, or assessing performance and improvement potential of a coached team. Current analysis workflows are typically based on the analysis of team videos. Also, analysts can rely on techniques from Information Visualization, to depict e.g., player or ball trajectories. However, video analysis is typically a time-consuming process, where the analyst needs to memorize and annotate scenes. In contrast, visualization typically relies on an abstract data model, often using abstract visual mappings, and is not directly linked to the observed movement context anymore. We propose a visual analytics system that tightly integrates team sport video recordings with abstract visualization of underlying trajectory data. We apply appropriate computer vision techniques to extract trajectory data from video input. Furthermore, we apply advanced trajectory and movement analysis techniques to derive relevant team sport analytic measures for region, event and player analysis in the case of soccer analysis. Our system seamlessly integrates video and visualization modalities, enabling analysts to draw on the advantages of both analysis forms. Several expert studies conducted with team sport analysts indicate the effectiveness of our integrated approach.

Journal ArticleDOI
TL;DR: This work reports direct experimental observations of Peltier cooling in molecular junctions by integrating conducting-probe atomic force microscopy with custom-fabricated picowatt-resolution calorimetric microdevices, which enables the unified characterization of electrical, thermoelectric and energy dissipation characteristics of Molecular junctions.
Abstract: The study of thermoelectricity in molecular junctions is of fundamental interest for the development of various technologies including cooling (refrigeration) and heat-to-electricity conversion 1-4 . Recent experimental progress in probing the thermopower (Seebeck effect) of molecular junctions 5-9 has enabled studies of the relationship between thermoelectricity and molecular structure 10,11 . However, observations of Peltier cooling in molecular junctions-a critical step for establishing molecular-based refrigeration-have remained inaccessible. Here, we report direct experimental observations of Peltier cooling in molecular junctions. By integrating conducting-probe atomic force microscopy 12,13 with custom-fabricated picowatt-resolution calorimetric microdevices, we created an experimental platform that enables the unified characterization of electrical, thermoelectric and energy dissipation characteristics of molecular junctions. Using this platform, we studied gold junctions with prototypical molecules (Au-biphenyl-4,4'-dithiol-Au, Au-terphenyl-4,4''-dithiol-Au and Au-4,4'-bipyridine-Au) and revealed the relationship between heating or cooling and charge transmission characteristics. Our experimental conclusions are supported by self-energy-corrected density functional theory calculations. We expect these advances to stimulate studies of both thermal and thermoelectric transport in molecular junctions where the possibility of extraordinarily efficient energy conversion has been theoretically predicted 2-4,14 .

Journal ArticleDOI
TL;DR: It is found that the ratio of interactions to individuals required to infer reliable hierarchies is surprisingly low, but depends on the steepness of the hierarchy and the method used, and two easy procedures to measure uncertainty and steepness in the inferred hierarchy are suggested.
Abstract: Many animal social structures are organized hierarchically, with some individuals monopolizing resources. Dominance hierarchies have received great attention from behavioural and evolutionary ecologists. There are many methods for inferring hierarchies from social interactions. Yet, there are no clear guidelines about how many observed dominance interactions (i.e. sampling effort) are necessary for inferring reliable dominance hierarchies, nor are there any established tools for quantifying their uncertainty. We simulate interactions (winners and losers) in scenarios of varying steepness (the probability that a dominant defeats a subordinate based on their difference in rank). Using these data, we (1) quantify how the number of interactions recorded and the steepness of the hierarchy affect the performance of five methods for inferring hierarchies, (2) propose an amendment that improves the performance of a popular method, and (3) suggest two easy procedures to measure uncertainty and steepness in the inferred hierarchy. We find that the ratio of interactions to individuals required to infer reliable hierarchies is surprisingly low, but depends on the steepness of the hierarchy and the method used. We show that David's score and our novel randomized Elo-rating are the best methods when hierarchies are not extremely steep, where the original Elo-rating, the I&SI and the recently described ADAGIO perform less well. In addition, we show that two simple methods can be used to estimate uncertainty at the individual and group level, and that the randomized Elo-rating repeatability provides researchers with a standardized measure valid for comparing the steepness of different hierarchies. We provide several worked examples to guide researchers interested in studying dominance hierarchies. Methods for inferring dominance hierarchies are relatively robust. We recommend that a ratio of observed interactions to individuals of at least 10 (for steep hierarchies), and ideally 20 serves as a good benchmark. Our simple procedures for estimating uncertainty in the observed data will facilitate evaluating whether sufficient data have been collected, while plotting the shape of the hierarchy will provide new insights into the social structure of the study organism.

Proceedings ArticleDOI
19 Apr 2018
TL;DR: The results of group-based, expert walkthroughs show that ART can facilitate immersion in the data, a fluid analysis process, and collaboration, and a set of guidelines are provided to foster the development of immersive technologies as tools for the collaborative analysis of multidimensional data.
Abstract: Immersive technologies such as augmented reality devices are opening up a new design space for the visual analysis of data. This paper studies the potential of an augmented reality environment for the purpose of collaborative analysis of multidimensional, abstract data. We present ART, a collaborative analysis tool to visualize multidimensional data in augmented reality using an interactive, 3D parallel coordinates visualization. The visualization is anchored to a touch-sensitive tabletop, benefiting from well-established interaction techniques. The results of group-based, expert walkthroughs show that ART can facilitate immersion in the data, a fluid analysis process, and collaboration. Based on the results, we provide a set of guidelines and discuss future research areas to foster the development of immersive technologies as tools for the collaborative analysis of multidimensional data.

Journal ArticleDOI
TL;DR: In this paper, the authors used quantitative data extracted from contests posted to Challenge.gov and qualitative interviews with thirty-six public managers in fourteen federal departments to discover and analyze intra-, inter, and extra-organizational factors that drive or hinder the implementation of OI in the public sector.
Abstract: Online Open Innovation (OI) platforms like Challenge.gov are used to post public sector problem statements, collect and evaluate ideas submitted by citizens with the goal to increase government innovation. Using quantitative data extracted from contests posted to Challenge.gov and qualitative interviews with thirty-six public managers in fourteen federal departments contribute to the discovery and analysis of intra-, inter, and extra-organizational factors that drive or hinder the implementation of OI in the public sector. The analysis shows that system-inherent barriers hinder public sector organizations to adopt this procedural and technological innovation. However, when the mandate of the innovation policy aligns with the mission of the organization, it opens opportunities for change in innovation acquisition and standard operating procedures.