6,230 research outputs found

    Public versus private debt: confidentiality, control, and product markets

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    The authors examine a firm's choice between public and private debt in a model where the firm's financing source affects its product market behavior. Two effects are examined. When frims' risk-taking decisions are strategic substitutes, debt financing leads to excessively risky product market strategies (as in Brander and Lewis' (1986) Cournot oligopoly with debt). Lender control through restrictive covenants--which is characteristic of private debt--can commit the firm to reduce aggressiveness in product markets and increase expected profits. This is the monitoring effect. On the other hand, private debt reduces the amount of public information about a firm that becomes available to its competitors. This is the confidentiality effect. When firms' risk-taking decisions are strategic substitutes, firms prefer to precommit to communicate idiosyncratic private information about costs or demand. By choosing public debt, a firm is able to precommit to communicate private information. The choice between public and private debt depends on the relative weights of the monitoring and confidentiality effects.Corporations - Finance ; Debt

    Highly Active Chiral Ruthenium Catalysts for Asymmetric Ring-Closing Olefin Metathesis

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    The synthesis of olefin metathesis catalysts containing chiral, monodentate N-heterocyclic carbenes and their application to asymmetric ring-closing metathesis (ARCM) are reported. These catalysts retain the high levels of reactivity found in the related achiral variants (1a and 1b). Using the parent chiral catalysts 2a and 2b and derivatives that contain steric bulk in the meta positions of the N-bound aryl rings (catalysts 3−5), five- through seven-membered rings were formed in up to 92% ee. The addition of sodium iodide to catalysts 2a−4a (to form 2b−4b in situ) caused a dramatic increase in enantioselectivity for many substrates. Catalyst 5a, which gave high enantiomeric excesses for certain substrates without the addition of NaI, could be used in loadings of ≀1 mol %. Mechanistic explanations for the large sodium iodide effect as well as possible mechanistic pathways leading to the observed products are discussed

    Why my photos look sideways or upside down? Detecting Canonical Orientation of Images using Convolutional Neural Networks

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    Image orientation detection requires high-level scene understanding. Humans use object recognition and contextual scene information to correctly orient images. In literature, the problem of image orientation detection is mostly confronted by using low-level vision features, while some approaches incorporate few easily detectable semantic cues to gain minor improvements. The vast amount of semantic content in images makes orientation detection challenging, and therefore there is a large semantic gap between existing methods and human behavior. Also, existing methods in literature report highly discrepant detection rates, which is mainly due to large differences in datasets and limited variety of test images used for evaluation. In this work, for the first time, we leverage the power of deep learning and adapt pre-trained convolutional neural networks using largest training dataset to-date for the image orientation detection task. An extensive evaluation of our model on different public datasets shows that it remarkably generalizes to correctly orient a large set of unconstrained images; it also significantly outperforms the state-of-the-art and achieves accuracy very close to that of humans

    Quantum description of spherical spins

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    The spherical model for spins describes ferromagnetic phase transitions well, but it fails at low temperatures. A quantum version of the spherical model is proposed. It does not induce qualitative changes near the phase transition. However, it produces a physical low temperature behavior. The entropy is non-negative. Model parameters can be adapted to the description of real quantum spins. Several applications are discussed. Zero-temperature quantum phase transitions are analyzed for a ferromagnet and a spin glass in a transversal field. Their crossover exponents are presented.Comment: 4 pages postscript. Revised version, to appear in Phys. Rev. Let

    How much do we really lose?—Yield losses in the proximity of natural landscape elements in agricultural landscapes

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    Natural landscape elements (NLEs) in agricultural landscapes contribute to biodiversity and ecosystem services, but are also regarded as an obstacle for large‐scale agricultural production. However, the effects of NLEs on crop yield have rarely been measured. Here, we investigated how different bordering structures, such as agricultural roads, field‐to‐field borders, forests, hedgerows, and kettle holes, influence agricultural yields. We hypothesized that (a) yield values at field borders differ from mid‐field yields and that (b) the extent of this change in yields depends on the bordering structure. We measured winter wheat yields along transects with log‐scaled distances from the border into the agricultural field within two intensively managed agricultural landscapes in Germany (2014 near Göttingen, and 2015–2017 in the Uckermark). We observed a yield loss adjacent to every investigated bordering structure of 11%–38% in comparison with mid‐field yields. However, depending on the bordering structure, this yield loss disappeared at different distances. While the proximity of kettle holes did not affect yields more than neighboring agricultural fields, woody landscape elements had strong effects on winter wheat yields. Notably, 95% of mid‐field yields could already be reached at a distance of 11.3 m from a kettle hole and at a distance of 17.8 m from hedgerows as well as forest borders. Our findings suggest that yield losses are especially relevant directly adjacent to woody landscape elements, but not adjacent to in‐field water bodies. This highlights the potential to simultaneously counteract yield losses close to the field border and enhance biodiversity by combining different NLEs in agricultural landscapes such as creating strips of extensive grassland vegetation between woody landscape elements and agricultural fields. In conclusion, our results can be used to quantify ecocompensations to find optimal solutions for the delivery of productive and regulative ecosystem services in heterogeneous agricultural landscapes
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