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

Extended stereotactic brain biopsy in suspected primary central nervous system angiitis: good diagnostic accuracy and high safety

OBJECTIVE To evaluate the diagnostic accuracy and safety of extended stereotactic brain biopsy (ESBB) in a single center cohort with suspected primary angiitis of the central nervous system (PACNS). METHODS A standardized stereotactic biopsy targeting MRI-positive lesions and collecting samples from the meninges and the cortex as well as from the white matter was performed in 23 patients with clinically suspected PACNS between 2010 and 2017. The relationship between biopsy yield and clinical characteristics, cerebrospinal fluid parameters, MR-imaging, time point of biopsy and exact localization of biopsy as well as number of tissue samples were examined. RESULTS PACNS was confirmed in 7 of 23 patients (30.4%). Alternative diagnoses were identified in 7 patients (30%). A shorter time period between the onset or worsening of symptoms (p = 0.018) and ESBB significantly increased the diagnostic yield. We observed only minor and transient postoperative complications in 3 patients (13.0%). ESBB led to a direct change of the therapeutic regime in 13 of 23 patients (56.5%). Careful neuropathological analysis furthermore revealed that cortical samples were crucial in obtaining a diagnosis. CONCLUSION ESBB is a safe approach with good feasibility, even in critically ill patients, and high diagnostic accuracy in patients with suspected PACNS changing future therapies in 13 of 23 patients (56.5%). Early biopsy after symptom onset/worsening is crucial and (sub)acute MRI-lesions should be targeted with a particular need for biopsy samples from the cortical layer