the Handelsblatt example

In the last years, Handelsblatt has published several rankings of business economists from German, Swiss and Austrian research institutions based on their journal publication output. These rankings have a strong influence on the academic profession. We scrutinize the Handelsblatt methodology by examining the effect the rankings’ underlying algorithms and assumptions have on the scores and ranks of individual researchers. In doing so, we clarify how robust the result is with respect to these internal parameters. Since the parameters used by Handelsblatt are not scientifically substantiated but defined ad hoc, this question is of great importance. For each parameter variation, we provide several robustness measures for both the Handelsblatt life’s work ranking and the Handelsblatt recent research performance ranking. E.g., if one applies a weighting scheme that lays more emphasis on first tier journal publications such that the weight of a particular category is always double of the weight of the next lower category, rank correlations based on all researchers in both personal rankings exceed 80 %. However, if one solely considers the top 25 performing researchers rank correlations fall below 50 and 20 % of researchers even drop out of this top group. Further research as well as the discussion in the academic community should clarify whether these correlations verify the robustness of the ranking or manifest the opposite

the Handelsblatt example

In the last years, Handelsblatt has published several rankings of business economists from German, Swiss and Austrian research institutions based on their journal publication output. These rankings have a strong influence on the academic profession. We scrutinize the Handelsblatt methodology by examining the effect the rankings’ underlying algorithms and assumptions have on the scores and ranks of individual researchers. In doing so, we clarify how robust the result is with respect to these internal parameters. Since the parameters used by Handelsblatt are not scientifically substantiated but defined ad hoc, this question is of great importance. For each parameter variation, we provide several robustness measures for both the Handelsblatt life’s work ranking and the Handelsblatt recent research performance ranking. E.g., if one applies a weighting scheme that lays more emphasis on first tier journal publications such that the weight of a particular category is always double of the weight of the next lower category, rank correlations based on all researchers in both personal rankings exceed 80 %. However, if one solely considers the top 25 performing researchers rank correlations fall below 50 and 20 % of researchers even drop out of this top group. Further research as well as the discussion in the academic community should clarify whether these correlations verify the robustness of the ranking or manifest the opposite

Divergent interest rates in the theory of financial markets

We extend models of financial markets by incorporating divergent risk-free interest rates for borrowing and deposits. Divergent interest rates create arbitrage opportunities if each market participant is allowed both to borrow and lend money. In our model, we circumvent such arbitrage opportunities by allowing only one institution to act as a bank (granting risk-free credits and financial investments). The surplus of this bank has to be redistributed to the market participants. Assuming only one risky asset we show that – while not necessarily unique – an equilibrium always exists. We investigate the relation to a financial markets equilibrium based on a unique interest rate being intuitively determined as a (weighted) average from borrowing and deposit rate. We provide proof that this unique interest rate approximately generates correct asset prices only if every investor trades, the bank's proceeds are distributed equally among investors and the number of investors is rather large. Otherwise severe mispricings may result

Some remarks on the debate on ‘WACC is not quite right

Miller (2009a) opened a debate in this journal on the correct determination of weighted average costs of capital (WACC). So far Bade (2009), Pierru (2009a), Lobe (2009) as well as Keef, Khaled, and Roush (2012) have contributed to this debate. Even though they discuss the same, rather simple valuation problem, the dispute cannot be considered resolved. Whilst they agree that Miller erroneously assumed constant leverage ratios, the center of discussion is now placed on the question whether or not cost of capital is constant over time when leverage changes and interest paid is not tax deductible. In particular, Keef et al. (2012) demand time-invariant WACC and criticize Bade (2009) and Pierru (2009a) for allowing WACC to change over time. The aim of this paper is twofold. Firstly, we show that the arguments of Keef et al. (2012) are flawed and their criticism of Bade (2009) and Pierru (2009a) is thus unfounded. Keef et al. (2012) are wrong to ignore that not only financial risk but also operational risk can change over time. Secondly, we provide evidence that cost of capital can also be dependent on the future state of nature. So far this fact has been neglected by all contributors to this debate and becomes obvious only if state-dependent cash flow realizations, not only their expected values, are considered as well

Bemerkungen zu Kapitalkostendefinitionen: Zugleich eine Kritik an Meitner/Streitferdt (2011)

--

Kurzumtriebsplantagen im Flächen- und Streifenanbau: Erfassung von Wachstumsparametern sowie faunistische und floristische Untersuchungen in Praxisanlagen

Auf Kurzumtriebsplantagen in drei unterschiedlichen Regionen wurden Untersuchungen zur Biodiversität, zur Entwicklung der Bestände und zur Wirkung auf angrenzende Ackerfrüchte durchgeführt. Einer der wichtigsten Effekte von Flächen und Streifen mit schnellwachsenden Baumarten ist der Erosionsschutz. Die Vorteile für die Biodiversität lassen sich durch eine Mindestflächengröße, gestaffelte Bewirtschaftung und zusätzliche Grün- und Blühstreifen noch verstärken. Feldstreifen sind einer flächigen Nutzung vorzuziehen. Ein Einfluss der Feldstreifen auf die angrenzende Feldfrucht konnte nicht nachgewiesen werden. Die Veröffentlichung richtet sich vor allem an Bewirtschafter und Planer von Kurzumtriebsplantagen und Agroforstsystemen

Opportunistic osteoporosis screening in multi-detector CT images via local classification of textures.

Our study proposed an automatic pipeline for opportunistic osteoporosis screening using 3D texture features and regional vBMD using multi-detector CT images. A combination of different local and global texture features outperformed the global vBMD and showed high discriminative power to identify patients with vertebral fractures. INTRODUCTION Many patients at risk for osteoporosis undergo computed tomography (CT) scans, usable for opportunistic (non-dedicated) screening. We compared the performance of global volumetric bone mineral density (vBMD) with a random forest classifier based on regional vBMD and 3D texture features to separate patients with and without osteoporotic fractures. METHODS In total, 154 patients (mean age 64 ± 8.5, male; n = 103) were included in this retrospective single-center analysis, who underwent contrast-enhanced CT for other reasons than osteoporosis screening. Patients were dichotomized regarding prevalent vertebral osteoporotic fractures (noFX, n = 101; FX, n = 53). Vertebral bodies were automatically segmented, and trabecular vBMD was calculated with a dedicated phantom. For 3D texture analysis, we extracted gray-level co-occurrence matrix Haralick features (HAR), histogram of gradients (HoG), local binary patterns (LBP), and wavelets (WL). Fractured vertebrae were excluded for texture-feature and vBMD data extraction. The performance to identify patients with prevalent osteoporotic vertebral fractures was evaluated in a fourfold cross-validation. RESULTS The random forest classifier showed a high discriminatory power (AUC = 0.88). Parameters of all vertebral levels significantly contributed to this classification. Importantly, the AUC of the proposed algorithm was significantly higher than that of volumetric global BMD alone (AUC = 0.64). CONCLUSION The presented classifier combining 3D texture features and regional vBMD including the complete thoracolumbar spine showed high discriminatory power to identify patients with vertebral fractures and had a better diagnostic performance than vBMD alone

FDG PET/CT to detect bone marrow involvement in the initial staging of patients with aggressive non-Hodgkin lymphoma: results from the prospective, multicenter PETAL and OPTIMAL>60 trials

Purpose Fluorine-18 fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG PET/CT) is the standard for staging aggressive non-Hodgkin lymphoma (NHL). Limited data from prospective studies is available to determine whether initial staging by FDG PET/CT provides treatment-relevant information of bone marrow (BM) involvement (BMI) and thus could spare BM biopsy (BMB). Methods Patients from PETAL (NCT00554164) and OPTIMAL>60 (NCT01478542) with aggressive B-cell NHL initially staged by FDG PET/CT and BMB were included in this pooled analysis. The reference standard to confirm BMI included a positive BMB and/or FDG PET/CT confirmed by targeted biopsy, complementary imaging (CT or magnetic resonance imaging), or concurrent disappearance of focal FDG-avid BM lesions with other lymphoma manifestations during immunochemotherapy. Results Among 930 patients, BMI was detected by BMB in 85 (prevalence 9%) and by FDG PET/CT in 185 (20%) cases, for a total of 221 cases (24%). All 185 PET-positive cases were true positive, and 709 of 745 PET-negative cases were true negative. For BMB and FDG PET/CT, sensitivity was 38% (95% confidence interval [CI]: 32–45%) and 84% (CI: 78–88%), specificity 100% (CI: 99–100%) and 100% (CI: 99–100%), positive predictive value 100% (CI: 96–100%) and 100% (CI: 98–100%), and negative predictive value 84% (CI: 81–86%) and 95% (CI: 93–97%), respectively. In all of the 36 PET-negative cases with confirmed BMI patients had other adverse factors according to IPI that precluded a change of standard treatment. Thus, the BMB would not have influenced the patient management. Conclusion In patients with aggressive B-cell NHL, routine BMB provides no critical staging information compared to FDG PET/CT and could therefore be omitted. Trial registration NCT00554164 and NCT0147854

Converting habits of antibiotic use for respiratory tract infections in German primary care – study protocol of the cluster-randomized controlled CHANGE-3 trial

Background: The overuse of antibiotics is a major cause for the worldwide rise of antibiotic resistance. Although it is well known that acute respiratory tract infections (ARTI) are mainly caused by viruses and are often self limiting, antibiotics are too frequently prescribed in primary care. CHANGE-3 examines whether a complex intervention focusing on improving communication and provision of prescribing feedback reduces antibiotic use in patients suffering from ARTI. Methods/design: The CHANGE-3 trial is a cluster-randomized controlled trial nested within a web-based public campaign conducted in two regions in Germany. A total of 114 medical practices will be included. Practices randomized to the intervention will receive a practice-specific antibiotic-prescription feedback and an educational outreach visit. During the visit the whole practice team will receive an introduction to e-learning modules addressing patient-centered communication on antibiotics. Furthermore, the practices will receive tablet PCs with information on antibiotics and the treatment of ARTI to be presented to patients. Practices randomized to the control will provide care as usual. The primary outcome measure is the antibiotic prescribing rate for patients with a history of ARTI. Data collected before the intervention, during the intervention and after the intervention will be compared. The use of narrow- vs. broad-spectrum antibiotics will be analyzed as a secondary outcome. A process evaluation is also part of the trial. Discussion: This study should contribute to the growing body of research on reducing antibiotic prescription. Trial registration: ISRCTN, ISRCTN15061174. Registered retrospectively on 13 July 2018

Genomic basis of a social polymorphism in a halictid bee

Item does not contain fulltex