A macro-financial analysis of the corporate bond market. National Bank of Belgium, Working Paper No. 360

We assess the contribution of economic and financial factors in the determination of euro area corporate bond spreads over the period 2001-2015. The proposed multi-market, no-arbitrage affine term structure model is based on the methodology proposed by Dewachter, Iania, Lyrio, and Perea (2015). We model jointly the ‘risk-free curve’, measured by overnight index swap (OIS) rates, and the corporate yield curves for two rating classes (A and BBB). The model includes four spanned and six unspanned factors. We find that, in general, both economic (real activity and inflation) and financial factors (proxying risk aversion, flight to liquidity and general financial market stress) play a significant role in the determination of the spanned factors and hence in the dynamics of the risk-free yield curve and corporate bond spreads. Across the risk-free OIS curve, macroeconomic and financial factors are each responsible on average for explaining 30 and 65 percent of yield variation, respectively. For A-and BBB-rated corporate debt, the selected financial variables explain on average 50 percent of the variation in corporate spreads during the last decade

Bundeswehrreform: Probleme der Finanzierung

"Seit Veröffentlichung der vom Verteidigungsminister erarbeiteten "Eckpfeiler" zur Bundeswehrreform und ihrer Billigung durch das Kabinett am 14. Juni 2000 ist die Finanzierbarkeit des Konzepts wiederholt bezweifelt oder bestritten worden. Tatsächlich ergibt schon eine Analyse unter optimistischen Annahmen, daß die Kosten die verfügbaren Mittel im Jahr 2006 (geplanter Abschluß der Umstrukturierung) mindestens um 2,2 Mrd. DM übersteigen dürften. So llte dieser Befund zutreffen, kann die vorgesehene Streitkräftestruktur nicht verwirklicht werden." (Autorenreferat

Bundeswehrreform: Schwachpunkt Krisenfähigkeit

"In der Debatte über die Bundeswehrreform dominiert die Kritik, das vom Verteidigungsminister vorgelegte Konzept sei nicht finanzierbar. Darüber hinaus ist auf einen weiteren bedenklichen Schwachpunkt hinzuweisen: Die Krisenfähigkeit bleibt unzureichend, weil der vorgesehene Umfang der kurzfristig verfügbaren und deshalb allein krisen(reaktions)fähigen Komponente der Einsatzkräfte zu knapp bemessen scheint und zudem nicht realisierbar sein dürfte. Sollte der Befund zutreffen, verfehlt die Reform einen wesen tlichen verteidigungspolitischen Zweck." (Autorenreferat

THE IMPLEMENTATION OF AN INTEGRATED PEST MANAGEMENT PROGRAM IN A MARYLAND PUBLIC SCHOOL SYSTEM

As part of the implementation of an Integrated Pest Management program in a public school system, an inventory of woody plants was created for 12 schools and key plants and key pests in the landscape were identified. In addition, the use of alternative tactics was examined for the control of insect and weed problems. The cost and efficacy of hand removal of bagworms (<em>Thyridopteryx ephemeraeformis</em>) from Leyland cypress (X <em>Cupressocyparis leylandii</em>) was compared to chemical treatment. Both treatments were effective, but handpicking was more costly. The efficacy and costs of the natural product based herbicides glufosinate, pelargonic acid, and acetic acid were compared to glyphosate for weed control in hardscape areas. The natural alternatives were effective, but at a higher cost. An alternative management program that eliminated the use of preemergent herbicides for weed control on athletic fields was also studied. The alternative program did not yield satisfactory results

Welche Bundeswehr für den neuen Auftrag? Die Freiwilligenarmee ist die bessere Lösung

'Den neuen verteidigungspolitischen Richtlinien zufolge dienen die deutschen Streitkräfte nicht mehr der Abwehr konventioneller Aggression, sondern internationaler Risikovorsorge einschließlich des Kampfes gegen den Terrorismus. Zur Umsetzung dieser bedeutendsten verteidigungspolitischen Neuorientierung seit Aufstellung der Bundeswehr ist es erforderlich, die überholte Verteidigungsarmee in eine moderne Krisen-Interventionsarmee umzugliedern. Wichtigste Voraussetzung ist eine entschiedene Steigerung der personellen und materiellen Einsatzleistungsfähigkeit. In der Studie werden Optionen aufgabengerechter Streitkräfte im Jahr 2010 bewertet. Eine Schlüsselfrage ist die nach der am besten geeigneten Wehrform. Gegenstand der Untersuchung ist deshalb die Bundeswehr ohne Wehrpflicht sowie mit allgemeiner Wehrpflicht und Auswahlwehrdienst gemäß Vorschlag der Weizsäcker-Kommission. Aus der Abwägung der militärischen, juristischen, gesellschaftspolitischen und finanziellen Befunde ergeben sich keine überzeugenden Argumente für die Wehrpflicht, wohl aber gewichtige Gründe gegen ihre Beibehaltung: Nicht zuletzt ist die Freiwilligenarmee die kostengünstigste der untersuchten Optionen und bei deutlich höherer Einsatzleistungsfähigkeit sogar kostengünstiger als die Bundeswehr heute. So ist der Bundesregierung die Umwandlung der Bundeswehr in eine Freiwilligenarmee zu empfehlen. Darüber hinaus wird vorgeschlagen, zur Sicherstellung des Bedarfs an Zeit- und Berufssoldaten eine neue Laufbahn für Kurzzeitsoldaten vorzusehen, Erst- und Weiterverpflichtungsprämien wieder einzuführen und die individuelle Verwendungsdauer in Auslandseinsätzen zu reduzieren.' (Autorenreferat

Clonal Progression during the T Cell-Dependent B Cell Antibody Response Depends on the Immunoglobulin DH Gene Segment Repertoire

The diversity of the third complementarity determining region of the IgH chain is constrained by natural selection of immunoglobulin diversity (D(H)) sequence. To test the functional significance of this constraint in the context of thymus-dependent (TD) immune responses, we immunized BALB/c mice with WT or altered D(H) sequence with 2-phenyloxazolone-coupled chicken serum albumin (phOx-CSA). We chose this antigen because studies of the humoral immune response to the hapten phOx were instrumental in the development of the current theoretical framework on which our understanding of the forces driving TD responses is based. To allow direct comparison, we used the classic approach of generating monoclonal Ab (mAb) from various stages of the immune response to phOx to assess the effect of changing the sequence of the D(H) on clonal expansion, class switching, and affinity maturation, which are hallmarks of TD responses. Compared to WT, TD-induced humoral IgM as well as IgG antibody production in the D-altered ΔD-DμFS and ΔD-iD strains were significantly reduced. An increased prevalence of IgM-producing hybridomas from late primary, secondary, and tertiary memory responses suggested either impaired class switch recombination (CSR) or impaired clonal expansion of class switched B cells with phOx reactivity. Neither of the D-altered strains demonstrated the restriction in the V(H)/V(L) repertoire, the elimination of V(H)1 family-encoded antibodies, the focusing of the distribution of CDR-H3 lengths, or the selection for the normally dominant Ox1 clonotype, which all are hallmarks of the anti-phOx response in WT mice. These changes in clonal selection and expansion, as well as CSR indicate that the genetic constitution of the D(H) locus, which has been selected by evolution, can strongly influence the functional outcome of a TD humoral response

Comparing adaptive and fixed bandwidth-based kernel density estimates in spatial cancer epidemiology

Background: Monitoring spatial disease risk (e.g. identifying risk areas) is of great relevance in public health research, especially in cancer epidemiology. A common strategy uses case-control studies and estimates a spatial relative risk function (sRRF) via kernel density estimation (KDE). This study was set up to evaluate the sRRF estimation methods, comparing fixed with adaptive bandwidth-based KDE, and how they were able to detect ‘risk areas’ with case data from a population-based cancer registry. Methods: The sRRF were estimated within a defined area, using locational information on incident cancer cases and on a spatial sample of controls, drawn from a high-resolution population grid recognized as underestimating the resident population in urban centers. The spatial extensions of these areas with underestimated resident population were quantified with population reference data and used in this study as ‘true risk areas’. Sensitivity and specificity analyses were conducted by spatial overlay of the ‘true risk areas’ and the significant (α=.05) p-contour lines obtained from the sRRF. Results: We observed that the fixed bandwidth-based sRRF was distinguished by a conservative behavior in identifying these urban ‘risk areas’, that is, a reduced sensitivity but increased specificity due to oversmoothing as compared to the adaptive risk estimator. In contrast, the latter appeared more competitive through variance stabilization, resulting in a higher sensitivity, while the specificity was equal as compared to the fixed risk estimator. Halving the originally determined bandwidths led to a simultaneous improvement of sensitivity and specificity of the adaptive sRRF, while the specificity was reduced for the fixed estimator. Conclusion: The fixed risk estimator contrasts with an oversmoothing tendency in urban areas, while overestimating the risk in rural areas. The use of an adaptive bandwidth regime attenuated this pattern, but led in general to a higher false positive rate, because, in our study design, the majority of true risk areas were located in urban areas. However, there is a strong need for further optimizing the bandwidth selection methods, especially for the adaptive sRRF.<br

Detecting cancer clusters in a regional population with local cluster tests and Bayesian smoothing methods: a simulation study

Background: There is a rising public and political demand for prospective cancer cluster monitoring. But there is little empirical evidence on the performance of established cluster detection tests under conditions of small and heterogeneous sample sizes and varying spatial scales, such as are the case for most existing population-based cancer registries. Therefore this simulation study aims to evaluate different cluster detection methods, implemented in the open soure environment R, in their ability to identify clusters of lung cancer using real-life data from an epidemiological cancer registry in Germany. Methods: Risk surfaces were constructed with two different spatial cluster types, representing a relative risk of RR = 2.0 or of RR = 4.0, in relation to the overall background incidence of lung cancer, separately for men and women. Lung cancer cases were sampled from this risk surface as geocodes using an inhomogeneous Poisson process. The realisations of the cancer cases were analysed within small spatial (census tracts, N = 1983) and within aggregated large spatial scales (communities, N = 78). Subsequently, they were submitted to the cluster detection methods. The test accuracy for cluster location was determined in terms of detection rates (DR), false-positive (FP) rates and positive predictive values. The Bayesian smoothing models were evaluated using ROC curves. Results: With moderate risk increase (RR = 2.0), local cluster tests showed better DR (for both spatial aggregation scales > 0.90) and lower FP rates (both < 0.05) than the Bayesian smoothing methods. When the cluster RR was raised four-fold, the local cluster tests showed better DR with lower FPs only for the small spatial scale. At a large spatial scale, the Bayesian smoothing methods, especially those implementing a spatial neighbourhood, showed a substantially lower FP rate than the cluster tests. However, the risk increases at this scale were mostly diluted by data aggregation. Conclusion: High resolution spatial scales seem more appropriate as data base for cancer cluster testing and monitoring than the commonly used aggregated scales. We suggest the development of a two-stage approach that combines methods with high detection rates as a first-line screening with methods of higher predictive ability at the second stage.<br