293 research outputs found

    Untersuchungen zur NIRS-Methodenentwicklung fĂŒr Kartoffeln aus dem Organischen Landbau unter BerĂŒcksichtigung von Jahrgangs- und SorteneinflĂŒssen

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    Im Rahmen einer nahinfrarot-spektrometrischen (NIRS) Methodenentwicklung fĂŒr sechs Kartoffelinhaltsstoffe (Trockenmasse, StĂ€rke, Rohprotein, Glucose, Fructose und Saccharose) wurde ein vorhandenes Kalibrationskollektiv (ca. 220 Proben aus drei Erntejahren und vier Sorten) mit ca. 200 Proben dreier neuer Erntejahre und einer neuen Sorte erweitert. Dabei konnte die bisherige Methodenleistung mit den untersuchten multivariaten Auswertungsmodellen (globale Modified Partial Least Squares Regression, Einzelprobenkalibration LOCAL und Ridge Regression) auch weiterhin erreicht werden. Als einen wesentlichen Einfluss auf die genannte Methodenleistung wurde eine inhomogene Verteilung der Spektrenpunkte im mehrfaktoriellen Raum ermittelt. Dabei wurden je nach Kartoffelsorte oder Erntejahr individuelle RĂ€ume innerhalb der Gesamtverteilung der Spektrenpunkte erkennbar. Dies erklĂ€rt auch, warum “kalibrationsfremde” Proben unter den gegebenen Bedingungen nur eingeschrĂ€nkt vorhergesagt werden können. Aus Untersuchungen mit der Ridge Regression wurde u.a. deutlich, dass eine Erweiterung der Spektren- und Inhaltsstoffmatrix mit nichtlinearen Termen keine Vorteile fĂŒr die Vorhersage der geprĂŒften Kartoffelproben bietet. Dennoch erreichten 30 % aller Vergleiche mit der Ridge Regression gegenĂŒber den beiden anderen Regressionsmodellen signifikant bessere Vorhersagen (alpha = 0,05), wĂ€hrend die ĂŒbrigen Ergebnisse der Ridge Regression keine Unterschiede zeigten. Sowohl fĂŒr die Proben der “kalibrationsfremden” Erntejahre als auch fĂŒr die der Sorten wurden mit der Ridge Regression gerade dann verbesserte SchĂ€tzwerte vorhergesagt, wenn mit den beiden anderen Verfahren unbefriedigende Ergebnisse erhalten wurden. WĂ€hrend der Lagerung konnten qualitĂ€tsrelevante VerĂ€nderungen in den Kartoffelknollen anhand der NIRS-SchĂ€tzwerte varianzanalytisch abgesichert werden. Damit kann die entwickelte NIRS-Methode fĂŒr entsprechende qualitĂ€tsorientierte Entscheidungen genutzt werden

    Investigating subclasses of abstract dialectical frameworks

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    Dialectical frameworks (ADFs) are generalizations of Dung argumentation frameworks where arbitrary relationships among arguments can be formalized. This additional expressibility comes with the price of higher computational complexity, thus an understanding of potentially easier subclasses is essential. Compared to Dung argumentation frameworks, where several subclasses such as acyclic and symmetric frameworks are well understood, there has been no in-depth analysis for ADFs in such direction yet (with the notable exception of bipolar ADFs). In this work, we introduce certain subclasses of ADFs and investigate their properties. In particular, we show that for acyclic ADFs, the different semantics coincide. On the other hand, we show that the concept of symmetry is less powerful for ADFs and further restrictions are required to achieve results that are similar to the known ones for Dung's frameworks. A particular such subclass (support-free symmetric ADFs) turns out to be closely related to argumentation frameworks with collective attacks (SETAFs); we investigate this relation in detail and obtain as a by-product that even for SETAFs symmetry is less powerful than for AFs. We also discuss the role of odd-length cycles in the subclasses we have introduced. Finally, we analyse the expressiveness of the ADF subclasses we introduce in terms of signatures

    Metal-to-Metal Distance Modulated Au(I)/Ru(II) Cyclophanyl Complexes : Cooperative Effects in Photoredox Catalysis

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    The modular synthesis of Au(I)/Ru(II) decorated mono- and heterobimetallic complexes with pi-conjugated [2.2]paracyclophane is described. [2.2]Paracyclophane serves as a rigid spacer which holds the metal centers in precise spatial orientations and allows metal-to-metal distance modulation. A broad set of architectural arrangements of pseudo -geminal, -ortho, -meta, and -para substitution patterns were employed. Metal-to-metal distance modulation of Au(I)/Ru(II) heterobimetallic complexes and the innate transannular pi-communication of the cyclophanyl scaffold provides a promising platform for the investigations of structure-activity relationship and cooperative effects. The Au(I)/Ru(II) heterobimetallic cyclophanyl complexes are stable, easily accessible, and exhibit promising catalytic activity in the visible-light promoted arylative Meyer-Schuster rearrangement.Peer reviewe

    Transport lattice models of heat transport in skin with spatially heterogeneous, temperature-dependent perfusion

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    BACKGROUND: Investigation of bioheat transfer problems requires the evaluation of temporal and spatial distributions of temperature. This class of problems has been traditionally addressed using the Pennes bioheat equation. Transport of heat by conduction, and by temperature-dependent, spatially heterogeneous blood perfusion is modeled here using a transport lattice approach. METHODS: We represent heat transport processes by using a lattice that represents the Pennes bioheat equation in perfused tissues, and diffusion in nonperfused regions. The three layer skin model has a nonperfused viable epidermis, and deeper regions of dermis and subcutaneous tissue with perfusion that is constant or temperature-dependent. Two cases are considered: (1) surface contact heating and (2) spatially distributed heating. The model is relevant to the prediction of the transient and steady state temperature rise for different methods of power deposition within the skin. Accumulated thermal damage is estimated by using an Arrhenius type rate equation at locations where viable tissue temperature exceeds 42°C. Prediction of spatial temperature distributions is also illustrated with a two-dimensional model of skin created from a histological image. RESULTS: The transport lattice approach was validated by comparison with an analytical solution for a slab with homogeneous thermal properties and spatially distributed uniform sink held at constant temperatures at the ends. For typical transcutaneous blood gas sensing conditions the estimated damage is small, even with prolonged skin contact to a 45°C surface. Spatial heterogeneity in skin thermal properties leads to a non-uniform temperature distribution during a 10 GHz electromagnetic field exposure. A realistic two-dimensional model of the skin shows that tissue heterogeneity does not lead to a significant local temperature increase when heated by a hot wire tip. CONCLUSIONS: The heat transport system model of the skin was solved by exploiting the mathematical analogy between local thermal models and local electrical (charge transport) models, thereby allowing robust, circuit simulation software to obtain solutions to Kirchhoff's laws for the system model. Transport lattices allow systematic introduction of realistic geometry and spatially heterogeneous heat transport mechanisms. Local representations for both simple, passive functions and more complex local models can be easily and intuitively included into the system model of a tissue

    EMIL: Extracting Meaning from Inconsistent Language

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    Developments in formal and computational theories of argumentation reason with inconsistency. Developments in Computational Linguistics extract arguments from large textual corpora. Both developments head in the direction of automated processing and reasoning with inconsistent, linguistic knowledge so as to explain and justify arguments in a humanly accessible form. Yet, there is a gap between the coarse-grained, semi-structured knowledge-bases of computational theories of argumentation and fine-grained, highly-structured inferences from knowledge-bases derived from natural language. We identify several subproblems which must be addressed in order to bridge the gap. We provide a direct semantics for argumentation. It has attractive properties in terms of expressivity and complexity, enables reasoning by cases, and can be more highly structured. For language processing, we work with an existing controlled natural language (CNL), which interfaces with our computational theory of argumentation; the tool processes natural language input, translates them into a form for automated inference engines, outputs argument extensions, then generates natural language statements. The key novel adaptation incorporates the defeasible expression ‘it is usual that’. This is an important, albeit incremental, step to incorporate linguistic expressions of defeasibility. Overall, the novel contribution of the paper is an integrated, end-to-end argumentation system which bridges between automated defeasible reasoning and a natural language interface. Specific novel contributions are the theory of ‘direct semantics’, motivations for our theory, results with respect to the direct semantics, an implementation, experimental results, the tie between the formalisation and the CNL, the introduction into a CNL of a natural language expression of defeasibility, and an ‘engineering’ approach to fine-grained argument analysis

    Observation of the solid-state photo-CIDNP effect in entire cells of cyanobacteria Synechocystis

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    Cyanobacteria are widely used as model organism of oxygenic photosynthesis due to being the simplest photosynthetic organisms containing both photosystem I and II (PSI and PSII). Photochemically induced dynamic nuclear polarization (photo-CIDNP) 13C magic-angle spinning (MAS) NMR is a powerful tool in understanding the photosynthesis machinery down to atomic level. Combined with selective isotope enrichment this technique has now opened the door to study primary charge separation in whole living cells. Here, we present the first photo-CIDNP observed in whole cells of the cyanobacterium Synechocystis

    Auxin controls gravitropic setpoint angle in higher plant lateral branches.

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    Lateral branches in higher plants are often maintained at specific angles with respect to gravity, a quantity known as the gravitropic setpoint angle (GSA) [1]. Despite the importance of GSA control as a fundamental determinant of plant form, the mechanisms underlying gravity-dependent angled growth are not known. Here we address the central questions of how stable isotropic growth of a branch at a nonvertical angle is maintained and of how the value of that angle is set. We show that nonvertical lateral root and shoot branches are distinguished from the primary axis by the existence of an auxin-dependent antigravitropic offset mechanism that operates in tension with gravitropic response to generate angled isotropic growth. Further, we show that the GSA of lateral roots and shoots is dependent upon the magnitude of the antigravitropic offset component. Finally, we show that auxin specifies GSA values dynamically throughout development by regulating the magnitude of the antigravitropic offset component via TIR1/AFB-Aux/IAA-ARF-dependent auxin signaling within the gravity-sensing cells of the root and shoot. The involvement of auxin in controlling GSA is yet another example of auxin's remarkable capacity to self-organize in development [2] and provides a conceptual framework for understanding the specification of GSA throughout nature

    Pulmonary Hypertension in Adults with Congenital Heart Disease: Real-World Data from the International COMPERA-CHD Registry

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    Introduction: Pulmonary hypertension (PH) is a common complication in patients with congenital heart disease (CHD), aggravating the natural, post-operative, or post-interventional course of the underlying anomaly. The various CHDs differ substantially in characteristics, functionality, and clinical outcomes among each other and compared with other diseases with pulmonary hypertension. Objective: To describe current management strategies and outcomes for adults with PH in relation to different types of CHD based on real-world data. Methods and results: COMPERA (Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension) is a prospective, international PH registry comprising, at the time of data analysis, >8200 patients with various forms of PH. Here, we analyzed a subgroup of 680 patients with PH due to CHD, who were included between 2007 and 2018 in 49 specialized centers for PH and/or CHD located in 11 European countries. At enrollment, the patients’ median age was 44 years (67% female), and patients had either pre-tricuspid shunts, post-tricuspid shunts, complex CHD, congenital left heart or aortic disease, or miscellaneous other types of CHD. Upon inclusion, targeted therapies for pulmonary arterial hypertension (PAH) included endothelin receptor antagonists, PDE-5 inhibitors, prostacyclin analogues, and soluble guanylate cyclase stimulators. Eighty patients with Eisenmenger syndrome were treatment-naïve. While at inclusion the primary PAH treatment for the cohort was monotherapy (70% of patients), with 30% of the patients on combination therapy, after a median observation time of 45.3 months, the number of patients on combination therapy had increased significantly, to 50%. The use of oral anticoagulants or antiplatelets was dependent on the underlying diagnosis or comorbidities. In the entire COMPERA-CHD cohort, after follow-up and receiving targeted PAH therapy (n = 511), 91 patients died over the course of a 5-year follow up. The 5-year Kaplan–Meier survival estimate for CHD associated PH was significantly better than that for idiopathic PAH (76% vs. 54%; p < 0.001). Within the CHD associated PH group, survival estimates differed particularly depending on the underlying diagnosis and treatment status. Conclusions: In COMPERA-CHD, the overall survival of patients with CHD associated PH was dependent on the underlying diagnosis and treatment status, but was significantly better as than that for idiopathic PAH. Nevertheless, overall survival of patients with PAH due to CHD was still markedly reduced compared with survival of patients with other types of CHD, despite an increasing number of patients on PAH-targeted combination therapy
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