20 research outputs found
Die Bedeutung der Periodenerfolgsrechnung für die Investitionssteuerung : der Fall ungleicher Zeitpräferenzen
Der internen Unternehmensrechnung werden im allgemeinen zwei Funktionen zugeschrieben (Ewert/Wagenhofer (1997), S. 6): Sie soll einerseits Informationen für Planungszwecke bereitstellen, andererseits der Verhaltenssteuerung von Entscheidungsträgern in hierarchischen, dezentralen Organisationen dienen. In der jüngeren Vergangenheit ist die Verhaltenssteuerungsfunktion zunehmend in das Blickfeld theoretischer und praktischer Überlegungen gerückt. Gleichzeitig läßt sich eine verstärkte Marktwertorientierung deutscher Unternehmen in der Unternehmenspolitik wie auch in der internen Unternehmensrechnung beobachten. Die betriebswirtschaftliche Literatur hat darauf mit einer wachsenden Zahl von Beiträgen reagiert, die die Marktwertorientierung der internen Unternehmensrechnung vor dem Hintergrund ihrer Verhaltenssteuerungsfunktion diskutieren.1) Das Interesse dieses Beitrags gilt der Rolle der Periodenerfolgsrechnung als Teil der internen Unternehmensrechnung bei der marktwertorientierten Steuerung von Investitionsentscheidungen über Periodenerfolgsbeteiligungen. Zentrale Bedeutung kommt hierbei dem Residualgewinnkonzept aufgrund seiner Kompatibilität mit dem Marktwertkriterium (vgl. Abschnitt 5.1) zu. Dieses Konzept hat in der Praxis unter dem Namen Economic Value Added zunehmend an Popularität - insbesondere auch als Grundlage für Erfolgsbeteiligungen (vgl. z.B. Stewart (1991), Ehrbar (1998), O'Hanlon/Peasnell (1998) ) - gewonnen. Gezeigt werden soll, welche Vorteile die Periodisierung von Cash Flows im Rahmen einer Periodenerfolgsrechnung auf der Basis des Residualgewinnkonzepts gegenüber einer unbelassenen Cash Flow-Rechnung bei der Steuerung von Investitionsentscheidungen über finanzielle Anreizsysteme bietet. Betrachtet wird eine einfache bilaterale Principal-Agent-Beziehung: Eine delegierende Instanz (Prinzipal) beauftragt einen Entscheidungsträger (Agenten) mit Investitionsentscheidungen und versucht, dessen Investitionsverhalten über eine „Erfolgsbeteiligung“ in ihrem Sinne auf das Ziel der Maximierung des Barwertes aller Cash Flows gerichtet zu beeinflussen. Die Rolle des internen Rechnungswesens ist dabei auf die Bereitstellung der Bemessungsgrundlage für die Erfolgsbeteiligung beschränkt. Es wird gezeigt, daß die Periodisierung von Cash Flows und die Zugrundelegung periodisierter Größen bei der Investitionssteuerung zu besseren Lösungen des Steuerungsproblems des Prinzipals führt als eine reine Cash Flow- Beteiligung. ...This paper considers the role of accrual accounting in providing investment incentives. In a simple multiperiod principal-agent-framework, it is assumed that the agent is wealth constrained and that he discounts future cash flows at a higher discount rate than the principal. The principal designs a linear performance fee based on either cash flows or residual income. Conditions are analyzed under which accrual accounting improves the solution to the principal's problem in comparison with a cash flow based performance fee. The role of accounting lies in (i) improving cash flow-sharing between principal and agent over time and (ii) improving investment incentives. It is shown that the potential sources of conflict which are considered generally lead to „traditional“ accounting rules
Non-equilibrium Superconductivity and Quasiparticle Dynamics studied by Photo Induced Activation of Mm-Wave Absorption (PIAMA)
We present a study of non-equilibrium superconductivity in DyBa2Cu3O7-d using
photo induced activation of mm-wave absorption (PIAMA). We monitor the time
evolution of the thin film transmissivity at 5 cm-1 subject to pulsed infrared
radiation. In addition to a positive bolometric signal we observe a second,
faster, decay with a sign opposite to the bolometric signal for T>40 K. We
attribute this to the unusual properties of quasi-particles residing near the
nodes of an unconventional superconductor, resulting in a strong enhancement of
the recombination time.Comment: 4 pages, REVTeX, Submitted to Phys. Rev. Letter
The interlayer cohesive energy of graphite from thermal desorption of polyaromatic hydrocarbons
We have studied the interaction of polyaromatic hydrocarbons (PAHs) with the
basal plane of graphite using thermal desorption spectroscopy. Desorption
kinetics of benzene, naphthalene, coronene and ovalene at sub-monolayer
coverages yield activation energies of 0.50 eV, 0.85 eV, 1.40 eV and 2.1 eV,
respectively. Benzene and naphthalene follow simple first order desorption
kinetics while coronene and ovalene exhibit fractional order kinetics owing to
the stability of 2-D adsorbate islands up to the desorption temperature.
Pre-exponential frequency factors are found to be in the range
- as obtained from both Falconer--Madix (isothermal
desorption) analysis and Antoine's fit to vapour pressure data. The resulting
binding energy per carbon atom of the PAH is 5 meV and can be identified
with the interlayer cohesive energy of graphite. The resulting cleavage energy
of graphite is ~meV/atom which is considerably larger than previously
reported experimental values.Comment: 8 pages, 4 figures, 2 table
Social Transfer of Pathogenic Fungus Promotes Active Immunisation in Ant Colonies
Social contact with fungus-exposed ants leads to pathogen transfer to healthy nest-mates, causing low-level infections. These micro-infections promote pathogen-specific immune gene expression and protective immunization of nest-mates
A model-constrained Monte Carlo method for blind arterial input function estimation in dynamic contrast-enhanced MRI: II. In vivo
A model-constrained Monte Carlo method for blind arterial input function estimation in dynamic contrast-enhanced MRI: I. Simulations
Improved evaluation of antivascular cancer therapy using constrained tracer-kinetic modeling for multi-agent dynamic contrast-enhanced MRI
Dynamic contrast-enhanced MRI (DCE-MRI) is a promising technique for assessing the response of tumor vasculature to anti-vascular therapies. Multi-agent DCE-MRI employs a combination of low and high molecular weight contrast agents, which potentially improves the accuracy of estimation of tumor hemodynamic and vascular permeability parameters. In this study, we employed multi-agent DCE-MRI to assess changes in tumor hemodynamics and vascular permeability after vascular-disrupting therapy. Multi-agent DCE-MRI (sequential injection of G5 dendrimer, G2 dendrimer, and Gd-DOTA) was performed in tumor-bearing mice before, 2 h and 24 h after treatment with vascular disrupting agent DMXAA or placebo. Constrained DCE-MRI gamma capillary transit time modeling was employed to estimate flow F, blood volume fraction vb, mean capillary transit time tc, bolus arrival time td, extracellular extravascular fraction ve, vascular heterogeneity index α-1 (all identical between agents) and extraction fraction E (reflective of permeability) and transfer constant Ktrans (both agent-specific) in perfused pixels. F, vb, and α-1 decreased at both time points after DMXAA, while tc increased. E (G2 and G5) showed an initial increase after which both parameters restored. Ktrans (G2 and Gd-DOTA) decreased at both time points after treatment. In the control, placebo-treated animals, only F, tc, and Ktrans Gd-DOTA showed significant changes. Histological perfused tumor fraction was significantly lower in DMXAA-treated versus control animals. Our results show how multi-agent tracer-kinetic modeling can accurately determine the effects of vascular-disrupting therapy, by separating simultaneous changes in tumor hemodynamics and vascular permeabilit
Cediranib/SC68896 treatment reduces tumor mean vessel density and increases mean lumen area.
<p><b>A)</b> Representative histological tumor sections with CD31 vascular staining (brown) and hematoxylin nuclear counter stain (blue) from the four treatment groups. Microvessel examples are marked by arrows. <b>B)</b> MVD quantified from multiple CD31 stained sections for the four treatment groups, indicating a significantly lower level for cediranib/SC68896 versus untreated (p<0.05). <b>C)</b> Mean lumen areas are indicated for the various treatment groups, with that for cediranib/SC68896 indicating a significantly higher level than untreated (p<0.05).</p
Cediranib/SC68896 treatment reduces tumor K<sup>trans</sup> and rCBF.
<p><b>A)</b> K<sup>trans</sup> (min<sup>−1</sup>) maps obtained from representative tumors from each treatment group during the final week of MRI evaluation; <b>B)</b> rCBF parametric maps (non-brain regions masked) from the same tumors as in A (CBF color scale is relative: contralateral hues set to ~unity).</p
Cediranib/SC68896 treatment slows tumor growth and increases mouse survival.
<p><b>A)</b> Representative T<sub>2</sub> weighted coronal mouse brain MR images obtained at 7 days after tumor growth initiation for the four treatment groups. <b>B)</b> Tumor growth curves are shown for the four treatment groups, in tumor volume versus time after tumor growth initiation. Curves are indicated for time points corresponding to ≥3 surviving mice, *: p<0.05 versus untreated. <b>C)</b> Mean exponential growth rate constants are shown for the four treatment groups, *: p<0.05 versus untreated. <b>D)</b> Kaplan-Meier survival curves for the four treatment groups (in days from tumor growth initiation), *: p<0.01 versus untreated.</p