“Does the tail wag the dog? The effect of credit default swaps on credit risk”

Credit default swaps (CDS) are derivative contracts that are widely used as tools for credit risk management. However, in recent years, concerns have been raised about whether CDS trading itself affects the credit risk of the reference entities. We use a unique, comprehensive sample covering CDS trading of 901 North American corporate issuers, between June 1997 and April 2009, to address this question. We find that the probability of both a credit rating downgrade and bankruptcy increase, with large economic magnitudes, after the inception of CDS trading. This finding is robust to controlling for the endogeneity of CDS trading. Beyond the CDS introduction effect, we show that firms with relatively larger amounts of CDS contracts outstanding, and those with relatively more “no restructuring” contracts than other types of CDS contracts covering restructuring, are more adversely affected by CDS trading. Moreover, the number of creditors increases after CDS trading begins, exacerbating creditor coordination failure for the resolution of financial distress

Asymmetric short-term adaptation of the vertical vestibulo-ocular reflex in humans

Anatomical and electrophysiological studies have demonstrated up-down asymmetries in vertical ocular motor pathways. We investigated whether these asymmetries extend to the capacity for short-term adaptation of the vertical vestibulo-ocular reflex (VVOR) in humans. Specifically, we asked whether smooth pursuit signals are sufficient to asymmetrically adapt the VVOR. Healthy human subjects (N=8), positioned 90° left-ear-down and fixating with their eyes upon a small laser dot (diameter: 0.1°) projected on a sphere (distance: 1.4m) were trained toward low VVOR gain for 30min with symmetric and asymmetric visual VVOR cancellation paradigms, while being oscillated (0.2Hz, ±20°) on a motorized turntable about the interaural earth-vertical axis. During asymmetric VVOR cancellation, the target was head-fixed in either the pitch-up or pitch-down half-cycles of oscillation (=trained direction) and space-fixed during the other half-cycles (=untrained direction). During symmetric VVOR cancellation, the target was head-fixed throughout the oscillations. Before and after adaptation, the pitch-up and pitch-down VOR gains were assessed during turntable oscillation in complete darkness. Before adaptation, average gains of pitch-up (0.75±0.15 SD) and pitch-down (0.79±0.19 SD) VOR were not significantly different (paired t test: P>0.05). On an average, relative gain reductions induced by selective pitch-up (pitch-up VOR: 32%; pitch-down VOR: 21%) and pitch-down (pitch-up VOR: 18%; pitch-down VOR: 30%) VOR cancellation were significantly (P<0.05) larger in the trained than in the untrained direction. Symmetric visual VVOR cancellation led to a significantly (P<0.01) larger relative gain reduction of the pitch-down (41%) than the pitch-up (33%) VOR. None of the paradigms led to significant changes of phase or offset. We conclude that, in human subjects, the smooth pursuit system is capable to asymmetrically decrease the gain of the VVOR equally well in both the upward and downward direction. The unexpected asymmetric decrease of the VVOR gain after symmetric visual cancellation may be related to the directional preferences of vertical gaze-velocity sensitive Purkinje cells in the flocculus for the downward directio

Head-Shaking Nystagmus Depends on Gravity

In acute unilateral peripheral vestibular deficit, horizontal spontaneous nystagmus (SN) increases when patients lie on their affected ear. This phenomenon indicates an ipsilesional reduction of otolith function that normally suppresses asymmetric semicircular canal signals. We asked whether head-shaking nystagmus (HSN) in patients with chronic unilateral vestibular deficit following vestibular neuritis is influenced by gravity in the same way as SN in acute patients. Using a three-dimensional (3-D) turntable, patients (N = 7) were placed in different whole-body positions along the roll plane and oscillated (1Hz, ±10°) about their head-fixed vertical axis. Eye movements were recorded with 3-D magnetic search coils. HSN was modulated by gravity: When patients lay on their affected ear, slow-phase eye velocity significantly increased upon head shaking and consisted of a horizontal drift toward the affected ear (average: 1.2°/s ±0.5 SD), which was added to the gravity-independent and directionally nonspecific SN. In conclusion, HSN in patients with chronic unilateral peripheral vestibular deficit is best elicited when they are lying on their affected ear. This suggests a gravity-dependent mechanism similar to the one observed for SN in acute patients, i.e., an asymmetric suppression of vestibular nystagmus by the unilaterally impaired otolith organ

"Man will ja Leute fit machen für das System." Eine qualitativ-empirische Rekonstruktion des Rollenselbstverständnisses von Job Coachs in der Schweiz

This qualitative study grants a first overview to what Job Coachs in a working environment understand as ‘Job Coaching’. This is done with a theoretical approach to the data trying to find a definition of Job Coaching. It becomes apparent, that Job Coaching only exists in the context of occupational and educational integration. Often welfare, unemployment benefits and disability pension are involved; therefore Job Coaching turns into a public sanction. Building on this outcome, the self-concept of Job Coachs is reviewed and developed in the context of the conflicting situations they act in. The conflicting situations express in the contradictory goals Job Coachs have, but also in the incoherency between the own values and the institutional implementation. Depending on the situation and audience, Job Coachs see themselves in the role of experts, trainers or lawyers relating to the Coachee. This demands high role flexibility. In conclusion, the results are discussed in a social context and the implications for practice, education, training and research.Diese qualitative Studie liefert einen ersten Überblick zu dem, was Job Coachs in der Praxis unter ‚Job Coaching‘ verstehen und nimmt mittels theoretischer Herangehensweise an das Datenmaterial eine Definitionsannäherung vor. Es zeigt sich, dass Job Coaching ausschliesslich im arbeits- und ausbildungsintegrativen Kontext auftritt. In vielen Fällen sind die sozialen Sicherungssysteme der Sozialhilfe, Arbeitslosen- und Invalidenversicherung involviert, wodurch das Job Coaching eine mehrheitlich staatliche Massnahme bildet. Daran anknüpfend wird das Rollenselbstverständnis von Job Coachs beleuchtet und im Kontext der oft widersprüchlichen Situationen, in denen sich die befragten Job Coachs befinden, entwickelt. Diese kommen in widersprüchlichen Zielsetzungen zum Ausdruck, aber gleichsam auch der Unvereinbarkeit mit der eigenen Werthaltung oder institutionellen Ausgestaltungen. Job Coachs sehen sich je nach Situation und Zielgruppe in einer Experten-, Trainier- oder Anwaltsrolle gegenüber ihren Coachee. Dies verlangt ihnen eine hohe Rollenflexibilität ab. Job Coaching wird in diesen Kontexten diskutiert und eingebettet. Abschliessend werden die Resultate zusammengefasst und Job Coaching in einen gesellschaftlichen Kontext eingebettet. Die Schlussfolgerungen werden für die Praxis, Lehre und Weiterbildung sowie die Forschung festgehalten.This qualitative study grants a first overview to what Job Coachs in a working environment understand as ‘Job Coaching’. This is done with a theoretical approach to the data trying to find a definition of Job Coaching. It becomes apparent, that Job Coaching only exists in the context of occupational and educational integration. Often welfare, unemployment benefits and disability pension are involved; therefore Job Coaching turns into a public sanction. Building on this outcome, the self-concept of Job Coachs is reviewed and developed in the context of the conflicting situations they act in. The conflicting situations express in the contradictory goals Job Coachs have, but also in the incoherency between the own values and the institutional implementation. Depending on the situation and audience, Job Coachs see themselves in the role of experts, trainers or lawyers relating to the Coachee. This demands high role flexibility. In conclusion, the results are discussed in a social context and the implications for practice, education, training and research

A model-based theory on the origin of downbeat nystagmus

The pathomechanism of downbeat nystagmus (DBN), an ocular motor sign typical for vestibulo-cerebellar lesions, remains unclear. Previous hypotheses conjectured various deficits such as an imbalance of central vertical vestibular or smooth pursuit pathways to be causative for the generation of spontaneous upward drift. However, none of the previous theories explains the full range of ocular motor deficits associated with DBN, i.e., impaired vertical smooth pursuit (SP), gaze evoked nystagmus, and gravity dependence of the upward drift. We propose a new hypothesis, which explains the ocular motor signs of DBN by damage of the inhibitory vertical gaze-velocity sensitive Purkinje cells (PCs) in the cerebellar flocculus (FL). These PCs show spontaneous activity and a physiological asymmetry in that most of them exhibit downward on-directions. Accordingly, a loss of vertical floccular PCs will lead to disinhibition of their brainstem target neurons and, consequently, to spontaneous upward drift, i.e., DBN. Since the FL is involved in generation and control of SP and gaze holding, a single lesion, e.g., damage to vertical floccular PCs, may also explain the associated ocular motor deficits. To test our hypothesis, we developed a computational model of vertical eye movements based on known ocular motor anatomy and physiology, which illustrates how cortical, cerebellar, and brainstem regions interact to generate the range of vertical eye movements seen in healthy subjects. Model simulation of the effect of extensive loss of floccular PCs resulted in ocular motor features typically associated with cerebellar DBN: (1) spontaneous upward drift due to decreased spontaneous PC activity, (2) gaze evoked nystagmus corresponding to failure of the cerebellar loop supporting neural integrator function, (3) asymmetric vertical SP deficit due to low gain and asymmetric attenuation of PC firing, and (4) gravity-dependence of DBN caused by an interaction of otolith-ocular pathways with impaired neural integrator functio

Does the Tail Wag the Dog? The Effect of Credit Default Swaps on Credit Risk

Concerns have been raised, especially since the global financial crisis, about whether trading in credit default swaps (CDS) increases the credit risk of the reference entities. This study examines this issue by quantifying the impact of CDS trading on the credit risk of firms. We use a unique, comprehensive sample covering 901 CDS introductions on North American corporate issuers between June 1997 and April 2009 to address this question. We present evidence that the probability of a credit downgrade and of bankruptcy both increase after the inception of CDS trading. The effect is robust to controlling for the endogeneity of CDS introduction, i.e., the possibility that firms selected for CDS trading are more likely to suffer a subsequent deterioration in creditworthiness. We show that the CDS-protected lenders&rsquo; reluctance to restructure is the most likely cause of the increase in credit risk. We present evidence that firms with relatively large amounts of CDS contracts outstanding, and those with &ldquo;No Restructuring&rdquo; contracts, are more likely to be adversely affected by CDS trading. We also document that CDS trading increases the level of participation of bank lenders to the firm. Our findings are broadly consistent with the predictions of the &ldquo;empty creditor&rdquo; model of Bolton and Oehmke (2011)

Agent-based dynamics in disaggregated growth models

This paper presents an agent-based model of disaggregated economic systems with endogenous growth features named Lagon GeneriC. This model is thought to represent a proof of concept that dynamically complete and highly disaggregated agent-based models allow to model economies as complex dynamical systems. It is used here for "theory generation", investigating the extension to a framework with capital accumulation of Gintis results on the dynamics of general equilibrium.Agent-based models, economic growth.

Hypertrophy of the Inferior Olivary Nucleus Impacts Perception of Gravity

Interruption of the dentato-olivary projections, interconnecting the dentate nucleus (DN) and the contralateral inferior olivary nucleus (ION), is predicted to interfere with the DN’ role in estimating direction of gravity. In a patient with pendular nystagmus due to hypertrophy of the ION secondary to predominantly right-sided ponto-mesencephalic hemorrhage, perceived vertical shifted from clockwise to counter-clockwise deviations within 4 months. We hypothesize that synchronized oscillations of ION neurons induce a loss of inhibitory control, leading to hyperactivity of the contralateral DN and, as a result, to perceived vertical roll–tilt to the side of the over-active DN

Medienkompetenz - Tipps zum sicheren Umgang mit digitalen Medien : für Eltern und alle, die mit Kids zu tun haben

Jugend und Medien. Nationales Programm zur Förderung von Medienkompetenzen. http://www.jugendundmedien.c

Biotic homogenisation and differentiation as directional change in beta diversity: synthesising driver–response relationships to develop conceptualmodels across ecosystems

Biotic homogenisation is defined as decreasing dissimilarity among ecological assemblages sampled within a given spatial area over time. Biotic differentiation, in turn, is defined as increasing dissimilarity over time. Overall, changes in the spatial dissimilarities among assemblages (termed ‘beta diversity’) is an increasingly recognised feature of broader biodiversity change in the Anthropocene. Empirical evidence of biotic homogenisation and biotic differentiation remains scattered across different ecosystems. Most meta-analyses quantify the prevalence and direction of change in beta diversity, rather than attempting to identify underlying ecological drivers of such changes. By conceptualising the mechanisms that contribute to decreasing or increasing dissimilarity in the composition of ecological assemblages across space, environmental managers and conservation practitioners can make informed decisions about what interventions may be required to sustain biodiversity and can predict potential biodiversity outcomes of future disturbances. We systematically reviewed and synthesised published empirical evidence for ecological drivers of biotic homogenisation and differentiation across terrestrial, marine, and freshwater realms to derive conceptual models that explain changes in spatial beta diversity. We pursued five key themes in our review: (i) temporal environmental change; (ii) disturbance regime; (iii) connectivity alteration and species redistribution; (iv) habitat change; and (v) biotic and trophic interactions. Our first conceptual model highlights how biotic homogenisation and differentiation can occur as a function of changes in local (alpha) diversity or regional (gamma) diversity, independently of species invasions and losses due to changes in species occurrence among assemblages. Second, the direction and magnitude of change in beta diversity depends on the interaction between spatial variation (patchiness) and temporal variation (synchronicity) of disturbance events. Third, in the context of connectivity and species redistribution, divergent beta diversity outcomes occur as different species have different dispersal characteristics, and the magnitude of beta diversity change associated with species invasions also depends strongly on alpha and gamma diversity prior to species invasion. Fourth, beta diversity is positively linked with spatial environmental variability, such that biotic homogenisation and differentiation occur when environmental heterogeneity decreases or increases, respectively. Fifth, species interactions can influence beta diversity via habitat modification, disease, consumption (trophic dynamics), competition, and by altering ecosystem productivity. Our synthesis highlights the multitude of mechanisms that cause assemblages to be more or less spatially similar in composition (taxonomically, functionally, phylogenetically) through time. We consider that future studies should aim to enhance our collective understanding of ecological systems by clarifying the underlying mechanisms driving homogenisation or differentiation, rather than focusing only on reporting the prevalence and direction of change in beta diversity, per se. biodiversity, beta diversity, biotic homogenisation, biotic differentiation, species assemblage, turnoverpublishedVersio