Anforderung an die Führung in Projekten : welcher Führungsstil ist der geeignetste?

Die vorliegende Arbeit beschäftigt sich mit der Frage, welche Anforderungen an die Führung in Projekten gestellt werden. Sie gibt einen Überblick, welcher Führungsstil sich am besten für die Leitung eines Projekts eignet. Die Meinungen internationaler Management-Experten unterscheiden sich hierbei in vielerlei Hinsicht. Das Hauptziel ist es nun, zu prüfen, mit welchem Führungsstil ein spezielles Projekt bzw. ein Projekterfolg abgesichert werden kann. Deshalb wird geprüft, wie sich der jeweilige Führungsstil auf das Ergebnis eines Projekts auswirken kann. Weiters soll festgehalten werden, wie es möglich wird, trotz Restriktionen ein Projekt erfolgreich und nutzbringend abzuschließen. Abschließend werden die Unterschiede zu der Führungim Unternehmen aufgezeigt sowie Handlungsempfehlungen für die betriebliche Projektpraxis erarbeitet

Calibration Strategies Designed For Long Term Sediment Transport Modelling

The presented work deals with the calibration of a 2D numerical model for the simulation of long term bed load transport. A settled basin along an alpine stream was used as a case study. The focus is to parameterise the used multi fractional transport model such that a dynamically balanced behavior regarding erosion and deposition is reached. The used 2D hydrodynamic model utilizes a multi-fraction multi-layer approach to simulate morphological changes and bed load transport. The mass balancing is performed between three layers: a top mixing layer, an intermediate subsurface layer and a bottom layer. Using this approach bears computational limitations in calibration. Due to the high computational demands, the type of calibration strategy is not only crucial for the result, but as well for the time required for calibration. Brute force methods such as Monte Carlo type methods may require a too large number of model runs. All here tested calibration strategies used multiple model runs utilising the parameterization and/or results from previous run. One concept was to reset to initial bed elevations after each run, allowing the resorting process to convert to stable conditions. As an alternative or in combination, the roughness was adapted, based on resulting nodal grading curves, from the previous run. Since the adaptations are a spatial process, the whole model domain is subdivided in homogeneous sections regarding hydraulics and morphological behaviour. For a faster optimization, the adaptation of the parameters is made section wise. Additionally, a systematic variation was done, considering results from previous runs and the interaction between sections. The used approach can be considered as similar to evolutionary type calibration approaches, but using analytical links instead of random parameter changes

Extension And Testing Of A 2D Hydrodynamic Model For Direct Rainfall Runoff Simulation

While the simulation of flood risks originating from the overtopping of river banks is well covered within continuously evaluated programs to improve flood protection measures, flash flooding is not. Flash floods are triggered by short, local thunderstorm cells with high precipitation intensities. Small catchments have short response times and flow paths and convective thunder cells may result in potential flooding of endangered settlements. Assessing local flooding and pathways of flood requires a detailed hydraulic simulation of the surface runoff. Hydrological models usually do not incorporate surface runoff at this detailedness but rather empirical equations are applied for runoff detention. In return 2D hydrodynamic models usually do not allow distributed rainfall as input nor are any types of soil/surface interaction implemented as in hydrological models. Considering several cases of local flash flooding during the last years the issue emerged for practical reasons but as well as research topics to closing the model gap between distributed rainfall and distributed runoff formation. Therefore, a 2D hydrodynamic model, depth-averaged flow equations using the finite volume discretization, was extended to accept direct rainfall enabling to simulate the associated runoff formation. The model itself is used as numerical engine, rainfall is introduced via the modification of waterlevels at fixed time intervals. The paper not only deals with the general application of the software, but intends to test the numerical stability and reliability of simulation results. The performed tests are made using different artificial as well as measured rainfall series as input. Key parameters of the simulation such as losses, roughness or time intervals for water level manipulations are tested regarding their impact on the stability

Reliability Of Simulated Discharges For Different Gauge Locations In A Semi Distributed Rainfall Runoff Model

In terms of flood forecasting in alpine environments, predictions at different gauges as well as sites with exposed infrastructure within the catchment are required. The used semi-distributed hydrological model HQsim combines runoff formation and surface runoff routines with an implemented channel routing for river reaches. This allows the estimation of discharges at selected channel segments. As a case study a large alpine catchment with a size of 890 km² is used. The uncertainty in the discharge prediction is investigated at three discharge gauges located along the main river. The basis of our experimental set-up are 15,000 samples describing the prior parameter distribution obtained by means of a Latin Hypercube sampling. Out of this, we calculated a Generalized Likelihood Uncertainty Estimation (GLUE) for the flood discharge at each gauging station. As informal likelihood a combination of different Nash Sutcliffe Efficiencies (NSE) is used covering summer season as well as flood periods containing peak discharges. Based on the behavioral parameter settings for each individual gauge, the model prediction distribution and their means for the remaining gauging stations are computed and analyzed

Clinical improvement of Long-COVID is associated with reduction in autoantibodies, lipids, and inflammation following therapeutic apheresis

In the aftermath of the COVID-19 pandemic, we are witnessing an unprecedented wave of post-infectious complications. Most prominently, millions of patients with Long-Covid complain about chronic fatigue and severe post-exertional malaise. Therapeutic apheresis has been suggested as an efficient treatment option for alleviating and mitigating symptoms in this desperate group of patients. However, little is known about the mechanisms and biomarkers correlating with treatment outcomes. Here, we have analyzed in different cohorts of Long-Covid patients specific biomarkers before and after therapeutic apheresis. In patients that reported a significant improvement following two cycles of therapeutic apheresis, there was a significant reduction in neurotransmitter autoantibodies, lipids, and inflammatory markers. Furthermore, we observed a 70% reduction in fibrinogen, and following apheresis, erythrocyte rouleaux formation and fibrin fibers largely disappeared as demonstrated by dark field microscopy. This is the first study demonstrating a pattern of specific biomarkers with clinical symptoms in this patient group. It may therefore form the basis for a more objective monitoring and a clinical score for the treatment of Long-Covid and other postinfectious syndromes

Hacia un cambio en el paradigma del manejo y modelación de sistemas de drenaje urbano en países en desarrollo

En países en vía de desarrollo, la falta de infraestructura de saneamiento básico y el número creciente de habitantes en sus centros urbanos han venido aumentando las demandas sobre los recursos hídricos disponibles. En el contexto de Bogotá (Colombia), este artículo emplea un marco de modelación integrada y presenta una revisión de estudios que han buscado una mejora en el manejo de los sistemas de drenaje urbano. Es sabido que hay una necesidad de evaluar estos sistemas como una única entidad cuando se busca propender por el control de la contaminación, su manejo y operación óptima. Esta visión holística ofrece la oportunidad de estudiar las interacciones entre los sub-sistemas y el impacto de la totalidad del sistema en la calidad del agua de los cuerpos receptores

Loss of Trex1 in Dendritic Cells Is Sufficient To Trigger Systemic Autoimmunity

Defects of the intracellular enzyme 3' repair exonuclease 1 (Trex1) cause the rare autoimmune condition Aicardi-Goutières syndrome and are associated with systemic lupus erythematosus. Trex1(-/-) mice develop type I IFN-driven autoimmunity, resulting from activation of the cytoplasmic DNA sensor cyclic GMP-AMP synthase by a nucleic acid substrate of Trex1 that remains unknown. To identify cell types responsible for initiation of autoimmunity, we generated conditional Trex1 knockout mice. Loss of Trex1 in dendritic cells was sufficient to cause IFN release and autoimmunity, whereas Trex1-deficient keratinocytes and microglia produced IFN but did not induce inflammation. In contrast, B cells, cardiomyocytes, neurons, and astrocytes did not show any detectable response to the inactivation of Trex1. Thus, individual cell types differentially respond to the loss of Trex1, and Trex1 expression in dendritic cells is essential to prevent breakdown of self-tolerance ensuing from aberrant detection of endogenous DNA

Absence of Type I Interferon Autoantibodies or Significant Interferon Signature Alterations in Adults With Post-COVID-19 Syndrome

Genetic defects in the interferon (IFN) system or neutralizing autoantibodies against type I IFNs contribute to severe COVID-19. Such autoantibodies were proposed to affect post-COVID-19 syndrome (PCS), possibly causing persistent fatigue for >12 weeks after confirmed SARS-CoV-2 infection. In the current study, we investigated 128 patients with PCS, 21 survivors of severe COVID-19, and 38 individuals who were asymptomatic. We checked for autoantibodies against IFN-α, IFN-β, and IFN-ω. Few patients with PCS had autoantibodies against IFNs but with no neutralizing activity, indicating a limited role of type I IFNs in PCS pathogenesis. In a subset consisting of 28 patients with PCS, we evaluated IFN-stimulated gene activity and showed that it did not correlate with fatigue. In conclusion, impairment of the type I IFN system is unlikely responsible for adult PCS