GRO.publications
Not a member yet
137257 research outputs found
Sort by
Simulation of proglacial forefield morphodynamics and their implications for the filtering of subglacial sediment export following glacier retreat
No full textAbstract Proglacial forefields are geomorphologically active zones with rivers that may buffer sediment connectivity between glaciers and downstream regions. To date, there are few studies of the magnitude of this process and the role of system‐internal perturbations, such as meltwater discharge rates, subglacial sediment supply and changing valley topography (e.g. valley slope, lateral accommodation space) following glacier retreat. Here, we use a physically‐based morphodynamic model, calibrated using continuous field‐collected data, to investigate the geomorphic response of these fluvial systems to varying topographical, sedimentological and hydrological boundary conditions. Results confirm the central role of the supply to transport capacity ratio in determining both proglacial stream geomorphic response and downstream sediment delivery rates, particularly for bedload particles; while suspended sediment transport is less affected by morphodynamic processes. Simulations also showed that the filtering effect is influenced by the lateral accommodation space and valley bottom slope. These observations not only suggest that the filtering varies between geomorphological settings, but also that the form of a valley (width, slope), as it is revealed following glacier retreat, will also impact filtering. These findings are important for understanding the future evolution of the longitudinal sediment connectivity in deglaciating catchments, in light of likely peak water and peak sediment. In the near‐future, the evolution of the proglacial margin filtering will have repercussion for the supply of sediment towards downstream regions, for the management of hydropower plants and for aquatic ecosystems.Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung https://doi.org/10.13039/50110000171
Improved GVHD-free relapse-free survival when rATG/ATLG is used in allo-HCT from matched sibling donors - an EBMT registry study by the Transplant Complications Working Party
No full textChandlerian growth in a ‘taboo market’? The American deathcare industry since the early 20th century
No full textFrölicher–Nijenhuis geometry and integrable matrix PDE systems
No full textAbstract Given two tensor fields of type (1, 1) on a smooth n -dimensional manifold M , such that all their Frölicher–Nijenhuis brackets vanish, the algebra of differential forms on M becomes a bi-differential graded algebra. As a consequence, there are systems of PDEs associated with it, which arise as the integrability condition of a system of linear equations and possess a binary Darboux transformation to generate exact solutions. We recover chiral models and potential forms of the self-dual Yang–Mills equations, as well as corresponding generalizations to higher than four dimensions, and obtain new integrable non-autonomous nonlinear matrix PDEs
Robert Shea Terrell. A Nation Fermented: Beer, Bavaria, and the Making of Modern Germany.
No full textEfficient Estimation in Extreme Value Regression Models of Hedge Funds Tail risks
No full textAbstract Extreme value regression offers a convenient framework to assess the effect of market variables on hedge funds tail risks, proxied by the tail index of the cross-section of hedge funds returns. However, its major limitation lies in the need to select a threshold below which data are discarded, leading to significant estimation inefficiencies. In this article, our main contribution consists in introducing a method to estimate simultaneously the tail index and the threshold parameter from the entire sample at hand, improving estimation efficiency. To do so, we extend the tail regression model to non-tail observations with an auxiliary splicing density, enabling the threshold to be internally determined without truncating the data. We then apply an artificial censoring mechanism to decrease specification issues at the estimation stage. Empirically, we investigate the determinants of hedge funds tail risks over time, and find a significant link with funding liquidity indicators. We also find that our tail risk measure has a significant predictive ability for the returns of around 25% of the funds. In addition, sorting funds along a tail risk sensitivity measure, we are able to discriminate between high- and low-alpha funds under some asset pricing models
Tracing stellar rotation in young massive LMC clusters
No full textABSTRACT We present a detailed analysis of stellar rotation along the main sequences of NGC 1866 and NGC 1856, two young (200–300 Myr) massive clusters in the Large Magellanic Cloud, using MUSE integral field spectroscopy. Differences in stellar rotation have been proposed as an explanation for the extended main sequence turn-offs and split main sequences in these clusters. In agreement with this idea, we find strong links between the photometric colours of the cluster stars and their projected rotation velocities, . While stars blueward of the split main sequences are characterized by a range of relatively low spins, those with redder colours are fast rotators. Following a statistical correction for inclination, we measure mean equatorial velocities for the red main-sequence stars in both clusters of km s, corresponding to 70–80 per cent of the critical values predicted for such stars by current stellar models. We discuss these findings in the context of the different scenarios proposed to explain the stellar rotation distributions of young massive clusters. We further investigate whether the high rotation rates provide a natural explanation for the high fractions of Be stars we observe in both clusters, peaking at 50 per cent at the turn-off. We argue that if of the critical rotation rate is high enough to trigger the formation of a decretion disc, most upper main sequence stars in the clusters are expected to become Be stars before leaving the main sequence
Post-traumatic stress disorder and REM-sleep behavior disorder: exploring genetic associations and causal links
No full textAbstract Objective To explore potential genetic and/or causal associations between Post-Traumatic Stress Disorder and neurodegeneration-related isolated/idiopathic rapid-eye-movement sleep behavior disorder. Methods We conducted polygenic risk score, genetic correlation, and Mendelian randomization analyses using the latest genome-wide association studies summary statistics and individual genotyping data. Next, a blinded observer examined dopamine transporter imaging binding status—a marker of neurodegeneration—in patients with isolated/idiopathic rapid-eye movement sleep behavior disorder, with (N = 6) and without Post-Traumatic Stress Disorder (N = 32). Results Polygenic risk scores for Post-Traumatic Stress Disorder were associated with isolated/idiopathic rapid-eye-movement sleep behavior disorder, with each standard deviation increase linked to 14.7% higher odds (odds ratio = 1.15, 95% confidence interval: 1.04 to 1.26, p = 0.005). However, genetic correlation was weak, and Mendelian randomization did not support a potential causal relationship. The proportion of individuals with abnormal dopamine transporter imaging binding status was significantly higher in the Post-Traumatic Stress Disorder group compared to those without the disorder (p=0.01, X 2 = 6.62). Interpretation Polygenic risk scores analysis identified an association between Post-Traumatic Stress Disorder and neurodegeneration-related isolated/idiopathic rapid-eye-movement sleep behavior disorder, consistent with the result from the small exploratory substudy. The lack of strong genetic correlation or causation may reflect limited sample size. Further research with larger and more diverse cohorts is crucial to clarify the genetic, biological and physiological mechanisms underlying this association
The role of CEO integrity in M&A decision‐making
No full textAbstract Research Summary While the influence of CEO characteristics on M&A decisions has long spurred researchers’ interest, little attention has been devoted to the ramifications of CEO integrity—the adherence to generally accepted norms and standards. We investigate how CEO integrity influences different stages of the M&A decision process. Specifically, we argue that while CEO integrity reduces self‐serving behavior, it may also become a golden cage that constrains CEOs’ latitude of action. Accordingly, we find that CEO integrity decreases the probability of Type I errors (errors of commission) but increases the probability of Type II errors (errors of omission) in M&A decision‐making. We contribute to theory development by putting forward CEO integrity as an important personality construct for upper echelons research to build on and extend further. Managerial Summary This paper examines how CEO integrity influences M&A decision‐making, providing key insights for corporate strategy. Analyzing data from S&P 1500 firms (2006‐2021), we find that CEOs with higher integrity are less likely to engage in frequent or large‐scale M&As, particularly avoiding cross‐border deals due to higher uncertainty and potential risks. High‐integrity CEOs also tend to pay lower acquisition premiums and take longer to complete deals, reflecting a cautious and thorough approach. While CEO integrity helps protect firms from costly mistakes it may also lead to missed growth opportunities, indicating a trade‐off between stakeholder considerations and strategic risk‐taking. Boards may need to tailor governance frameworks to optimize the balance between the benefits and constraints of CEO integrity