Operational rules for sustainable sediment management of dam cascades: Application to Mekong hydropower dams in Lao PDR

Hydropower plants have proven to generate electricity reliably and predictably, store water to meet water demands during dry periods, improve navigability and reduce flood risk. The reservoirs of these hydropower plants face ongoing sedimentation, negatively effecting the electricity generation, water storage volume, navigability and flood risk. Obtaining an equilibrium of the in- and outgoing sediment flux reduces these negative effects.The incentive for this report is the planned run-of-river hydropower dam cascade in the main stream Mekong river in Lao PDR. The Mekong river is characterised by the distinct low and high flow seasons and a unique ecosystem. At the location of the planned cascade, the river is located between mountains and the river bed consists of bedrock with alluvial bed forms at the banks and between rock outcrops.Long, narrow and relatively shallow reservoirs are created due to the construction of the planned dams in the main stream Mekong. Flushing operations have proven to be an effective method to recover reservoir volume from rivers with a high season flow with long, narrow and shallow reservoirs. The Mekong river in Lao PDR has all those properties.This report attempts to determine operational rules for a run-of-river hydropower dam cascade to increase the sediment flux by flushing operations at the dams, whilst still maximizing the electricity generation. To do so, two steps are taken. Firstly, a set of experiments on the Mekong river and flushing events at a dam is performed in a Delft3D-FM software with the Real Time Control module. The output of these experiments are used as input for a bucket model with volume conservation to test different operational rules.Using the Delft3D-FM software with the Real Time Control module, a one-dimensional representation of the Mekong river is made. This model is used for two purposes. First, the reduction of the sediment flux is determined by comparing the sediment flux during a representative year for the situation pre-dam and post-dam construction. Secondly, this model is used to test the influence of the draw down rate, water level set point and duration of flushing operations on the cumulative sediment flux through a dam for four different discharges. The results of the flushing experiments will then be used as input for the second step of the research, the bucket model.Different simulations are performed using operational rules with different threshold discharges for initiating flushing events, different draw down rates and different frequencies of flushing a reservoir. Using random sampling the influence of these three variables is tested. Additionally, two predetermined strategies are tested and compared to the operational rules tested using random sampling. In the first strategy the dams in the cascade are flushing progressively from the most upstream dam towards the downstream dam. The second operational strategy flushes the reservoirs progressively starting from the downstream dam towards the most upstream dam.Obtaining free flowing conditions during a flushing event increases the sediment flux significantly compared to flushing events that do not reach free flowing conditions, especially for lower discharges. Increasing the draw down rate proves to have limited influence on the sediment flux further upstream in the reservoir, while the flood wave released at the dam increases. Extending the duration of free flowing conditions after draw down proves to be an effective method to increase the sediment flux at the lowest reducing in electricity generation. Performing a flushing event with 48 hours at free flowing conditions during the flood season increases the yearly cumulative sediment flux on average by a factor three. The cumulative electricity generation is reduced by just 2.5 %. Extending the duration of the free flowing conditions in a flushing event increases the sediment flux per lost GWh electricity generation.Current operational rules at the planned cascade in the main stream Mekong do not consider flushing at all. It is recommended to include flushing events in the operational rules which are initiated if the discharge is above the design discharge of the turbines and below extreme discharges to increase the sediment flux and minimize electricity generation loss.Civil Engineering | Hydraulic Engineerin

Leducq Transatlantic Network of Excellence to Cure Phospholamban-Induced Cardiomyopathy (CURE-PLaN)

The deletion of Arginine 14 of the phosholamban gene (PLN p.R14del) is associated with the pathogenesis of an inherited form of cardiomyopathy with prominent arrhythmias. Patients carrying the PLN R14del mutation are at risk of developing dilated cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy. Although the genetic etiology is well defined, the molecular mechanism underlying the pathogenesis of PLN R14del-cardiomyopathy is unknown. Our CURE PLaN network, funded by the Foundation Leducq, will bring together leading scientists, clinicians, and patients to elucidate the genotype-phenotype relationships in R14del cardiomyopathy with the ultimate goal of developing innovative disease-specific therapeutic modalities. With the generous support of the Leducq Foundation, our Transatlantic Network of Excellence consortium to cure Phospholamban (PLN)-induced cardiomyopathy (CURE-PLaN) unites 6 leading centers to address the current challenges associated with arrhythmogenic right ventricular cardiomyopathy/dilated cardiomyopathy (DCM) with an initial focus on PLN and development of effective treatments. The Network is led by Evangelia (Litsa) Kranias (University of Cincinnati) in the United States and Pieter A. Doevendans (Netherlands Heart Institute/UMC Utrecht NL) in Europe. The other US project leaders are Kevin Costa (Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York) and Mark Mercola and Ioannis Karakikes (Stanford University), who are focusing on induced pluripotent stem cell (iPSC)-based disease models, tissue engineering, gene therapy, and drug discovery. On the European side, the project leaders are Despina Sanoudou (Biomedical Research Foundation of the Academy of Athens) analyzing the PLN interactome and Stephan Lehnart (University of Gottingen) addressing the subcellular and disrupted protein interactions affected in PLN-mutant cardiomyocytes. Other key members within the Netherlands Heart Institute are Peter van Tintelen on PLN genetics, Folkert Asselbergs on epigenetics and Rudolf de Boer on clinical trials. We are also privileged to get support from Arthur Wilde (University of Amsterdam), Sakthivel Sadayappan (University of Cincinnati), and Roger Hajjar (Phospholamban Foundation), who have had a long-standing interest in cardiac physiology and pathophysiology with emphasis on underlying pathways and potential therapeutic targets. The consortium is also fortunate to embrace a patient advocate, Pieter Glijnis, incorporating the voice of the patients to research in every step. Our goal is to build and share a platform of patient data coupled with in vitro and in vivo models to promote scientific discovery and advance novel treatments. Phospholamban is a small phosphoprotein in the cardiac sarcoplasmic reticulum, and it is the major regulator of SERCA2a activity and calcium (Ca)-cycling. Chronic inhibition of SERCA2a by PLN has been implicated in the aberrant Ca-cycling of failing hearts. Studies in HF models have shown that decreasing PLN activity may rescue cardiac remodeling and dysfunction. Several human PLN mutations, leading to inhibition of Ca-uptake into the sarcoplasmic reticulum, are linked to inherited DCM

Will our cardiomyopathy patients accept gene therapy?

Novel techniques such as gene therapy are becoming available in an attempt to cure inherited diseases. Before these new therapies can be offered to patients, we need to be aware of potential reservations or objections, not only from patients and their surroundings but also from the public. In addition, legal issues and costs need attention before curative gene therapy can be applied in the clinic. As this therapeutic approach is closer to becoming a reality, now is the right time to start the debate

Enabling the IT industry to specify and evaluate user-oriented quality

Until recently, the IT community has focused most of its attention on the software development process, particularly managing its improvement. However, this emphasis provides no guarantee for the ‘fitness-for-use" quality of the final software products as experienced by the actual users. While recent European pr~jects and standardisation efforts have addressed software product quality, this has primarily been from a "technical" point of view. Manufacturers of software wish to demonstrate ‘fitness-for-use" quality, preferably by means of generally accepted standards. They want to reduce the "time-to-market" and the number of releases. This can be done by taking the user needs into account efftctively, at an early stage of development. The time has come to bridge these gaps as a response to the actual user needs for software product quality

Enabling the IT industry to specify and evaluate user-oriented quality

Until recently, the IT community has focused most of its attention on the software development process, particularly managing its improvement. However, this emphasis provides no guarantee for the ‘fitness-for-use" quality of the final software products as experienced by the actual users. While recent European pr~jects and standardisation efforts have addressed software product quality, this has primarily been from a "technical" point of view. Manufacturers of software wish to demonstrate ‘fitness-for-use" quality, preferably by means of generally accepted standards. They want to reduce the "time-to-market" and the number of releases. This can be done by taking the user needs into account efftctively, at an early stage of development. The time has come to bridge these gaps as a response to the actual user needs for software product quality