1,112 research outputs found

    Early-Modern Magnetism: Uncovering New Textual Links between Leonardo Garzoni SJ (1543–1592), Paolo Sarpi OSM (1552–1623), Giambattista Della Porta (1535–1615), and the Accademia dei Lincei

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    William Gilbert’s work, De magnete (1600), often is referred to as the first monographic study on magnetism in the early-modern period. Recently, however, it has been argued that the Jesuit, Leonardo Garzoni, wrote an experimental study on the subject twenty years earlier and that his research influenced particularly the work of Giambattista Della Porta and Paolo Sarpi,two important protagonists in the history of studies in magnetism. However, to date, Garzoni’s authorship of an anonymous treatise in manuscript, located at the Biblioteca Ambrosiana in Milan, and taken to bear witness to his research, has been based only on circumstantial evidence. This article outlines the identification of two further manuscript copies of this treatise, which have not been studied so far. It shall be argued that the evidence contained in these manuscripts corroborates the assumption that Garzoni indeed is the author of the work that was transmitted anonymously. Moreover, it can be shown that the work was completed and prepared for print later on. These findings also allow us to argue more conclusively that Paolo Sarpi knew Garzoni’s work and passed it to Giambattista Della Porta, who bequethed his copy to the Accademia dei Lincei and thereby made it available to some of the academy’s most important members, Nicolas Claude Fabri de Peiresc and Cassiano Dal Pozzo. Finally, the dynamics of this textual transmission provide insights into how scholars approached the study of ‘magnetism’ in the early-modern period

    Localized ultraviolet laser microbeam irradiation of early Drosophila embryos: Fate maps based on location and frequency of adult defects

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    Drosophila embryos were locally irradiated with a 257-nm laser microbeam during blastoderm and germ band stages. Depending on stage and beam diameter (10–30 ÎŒm), from 0 to 45 nuclei were exposed to the uv radiation. The doses used, 5 or 10 erg, did not eliminate nuclei or cells at once, but up to 50% of the adult survivors from irradiated eggs carried defects in the thorax. These were scored with reference to the imaginal discs from which the affected structures derive. For each thoracic disc a “target center” was calculated as the weighted mean value of all beam locations affecting the respective adult derivatives. The target centers for the germ band stage map within the respective germ band segments. The pattern of target centers for the blastoderm stage is comparable to the thoracic region of published fate maps, and the distances between adjacent leg centers (approximately three cell diameters) agree with recent evidence based on mosaic flies. We discuss the question whether the target centers mark the position of the respective disc progenitor cells at the stages of irradiation and conclude that these positions are rendered rather correctly at least with reference to the longitudinal egg axis

    Recognizable Graph Languages for Checking Invariants

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    We generalize the order-theoretic variant of the Myhill-Nerode theorem to graph languages, and characterize the recognizable graph languages as the class of languages for which the Myhill-Nerode quasi order is a well quasi order. In the second part of the paper we restrict our attention to graphs of bounded interface size, and use Myhill-Nerode quasi orders to verify that, for such bounded graphs, a recognizable graph property is an invariant of a graph transformation system. A recognizable graph property is a recognizable graph language, given as an automaton functor. Finally, we present an algorithm to approximate the Myhill-Nerode ordering

    Taylor-Couette turbulence at radius ratio η=0.5\eta=0.5: scaling, flow structures and plumes

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    Using high-resolution particle image velocimetry we measure velocity profiles, the wind Reynolds number and characteristics of turbulent plumes in Taylor-Couette flow for a radius ratio of 0.5 and Taylor number of up to 6.2⋅1096.2\cdot10^9. The extracted angular velocity profiles follow a log-law more closely than the azimuthal velocity profiles due to the strong curvature of this η=0.5\eta=0.5 setup. The scaling of the wind Reynolds number with the Taylor number agrees with the theoretically predicted 3/7-scaling for the classical turbulent regime, which is much more pronounced than for the well-explored η=0.71\eta=0.71 case, for which the ultimate regime sets in at much lower Ta. By measuring at varying axial positions, roll structures are found for counter-rotation while no clear coherent structures are seen for pure inner cylinder rotation. In addition, turbulent plumes coming from the inner and outer cylinder are investigated. For pure inner cylinder rotation, the plumes in the radial velocity move away from the inner cylinder, while the plumes in the azimuthal velocity mainly move away from the outer cylinder. For counter-rotation, the mean radial flow in the roll structures strongly affects the direction and intensity of the turbulent plumes. Furthermore, it is experimentally confirmed that in regions where plumes are emitted, boundary layer profiles with a logarithmic signature are created

    A Simulation Tool Chain for Investigating Future V2X-based Automotive E/E Architectures

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    Due to the evermore rising number of functions, current E/E architectures are more and more a vulnerable source for faults and a barrier to innovation. This situation is aggravated by the integration of new technologies like Vehicle-to-X Communication (V2XC) which form the basis for a large number of future services and applications. At the same time, this “opening” of the E/E architecture to the outside world increases potential for non-deterministic disturbances. In order to overcome the limitations of current E/E architectures, application of new design principles and methodologies is necessary. Platform-based design (PBD) is a promising solution for the development of safety-critical functions, to increase reliability and to reduce development cost. Within this context, we propose a novel extensible tool chain that targets the facilitation of exploration, validation and verification of future V2X-based automotive E/E architectures. The tool chain supports composition of heterogeneous domain-specific models by integrating a heterogeneous modeling tool with a simulation middleware and serves as starting point for the investigation of PBD concepts in the V2X context. We believe that the tool chain can support modeling and validation of future V2X-based E/E architectures. In the final paper, we will evaluate the proposed approach by means of a case study regarding validation capabilities as well as execution performance

    Treewidth, Pathwidth and Cospan Decompositions

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    We will revisit the categorical notion of cospan decompositions of graphs and compare it to the well-known notions of path decomposition and tree decomposition from graph theory. More specifically, we will define several types of cospan decompositions with appropriate width measures and show that these width measures coincide with pathwidth and treewidth. Such graph decompositions of small width are used to efficiently decide graph properties, for instance via graph automata

    A climate service for ecologists: sharing pre-processed EURO-CORDEX regional climate scenario data using the eLTER information system

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    eLTER was a “Horizon 2020” project with the aim of advancing the development of long-term ecosystem research infrastructure in Europe. This paper describes how eLTER Information System infrastructure has been expanded by a climate service data product providing access to specifically pre-processed regional climate change scenario data from a state-of-the-art regional climate model ensemble of the Coordinated Regional Downscaling Experiment (CORDEX) for 702 registered ecological research sites across Europe. This tailored, expandable, easily accessible dataset follows FAIR principles and allows researchers to describe the climate at these sites, explore future projections for different climate change scenarios and make regional climate change assessments and impact studies. The data for each site are available for download from the EUDAT collaborative data infrastructure B2SHARE service and can be easily accessed and visualised through the Dynamic Ecological Information Management System – Site and Dataset Registry (DEIMS-SDR), a web-based information management system which shares detailed information and metadata on ecological research sites around the globe. This paper describes these data and how they can be accessed by users through the extended eLTER Information System architecture. The data and supporting information are available from B2SHARE. Each individual site (702 sites are available) dataset has its own DOI. To aid data discovery, a persistent B2SHARE lookup table has been created which matches the DOIs of the individual B2SHARE record with each DEIMS site ID. This lookup table is available at https://doi.org/10.23728/b2share.bf41278d91b445bda4505d5b1eaac26c (eLTER EURO-CORDEX Climate Service, 2020)

    Activation of Rac-1 and RhoA contributes to podocyte injury in chronic kidney disease

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    Rho-family GTPases like RhoA and Rac-1 are potent regulators of cellular signaling that control gene expression, migration and inflammation. Activation of Rho-GTPases has been linked to podocyte dysfunction, a feature of chronic kidney diseases (CKD). We investigated the effect of Rac-1 and Rho kinase (ROCK) inhibition on progressive renal failure in mice and studied the underlying mechanisms in podocytes. SV129 mice were subjected to 5/6-nephrectomy which resulted in arterial hypertension and albuminuria. Subgroups of animals were treated with the Rac-1 inhibitor EHT1846, the ROCK inhibitor SAR407899 and the ACE inhibitor Ramipril. Only Ramipril reduced hypertension. In contrast, all inhibitors markedly attenuated albumin excretion as well as glomerular and tubulo-interstitial damage. The combination of SAR407899 and Ramipril was more effective in preventing albuminuria than Ramipril alone. To study the involved mechanisms, podocytes were cultured from SV129 mice and exposed to static stretch in the Flexcell device. This activated RhoA and Rac-1 and led via TGFÎČ to apoptosis and a switch of the cells into a more mesenchymal phenotype, as evident from loss of WT-1 and nephrin and induction of α-SMA and fibronectin expression. Rac-1 and ROCK inhibition as well as blockade of TGFÎČ dramatically attenuated all these responses. This suggests that Rac-1 and RhoA are mediators of podocyte dysfunction in CKD. Inhibition of Rho-GTPases may be a novel approach for the treatment of CKD
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