What is the Nature of EUV Waves? First STEREO 3D Observations and Comparison with Theoretical Models

One of the major discoveries of the Extreme ultraviolet Imaging Telescope (EIT) on SOHO were intensity enhancements propagating over a large fraction of the solar surface. The physical origin(s) of the so-called `EIT' waves is still strongly debated. They are considered to be either wave (primarily fast-mode MHD waves) or non-wave (pseudo-wave) interpretations. The difficulty in understanding the nature of EUV waves lies with the limitations of the EIT observations which have been used almost exclusively for their study. Their limitations are largely overcome by the SECCHI/EUVI observations on-board the STEREO mission. The EUVI telescopes provide high cadence, simultaneous multi-temperature coverage, and two well-separated viewpoints. We present here the first detailed analysis of an EUV wave observed by the EUVI disk imagers on December 07, 2007 when the STEREO spacecraft separation was $\approx 45^\circ$. Both a small flare and a CME were associated with the wave cadence, and single temperature and viewpoint coverage. These limitations are largely overcome by the SECCHI/EUVI observations on-board the STEREO mission. The EUVI telescopes provide high cadence, simultaneous multi-temperature coverage, and two well-separated viewpoints. Our findings give significant support for a fast-mode interpretation of EUV waves and indicate that they are probably triggered by the rapid expansion of the loops associated with the CME.Comment: Solar Physics, 2009, Special STEREO Issue, in pres

Impact of nationwide enhanced implementation of best practices in pancreatic cancer care (PACAP-1):a multicenter stepped-wedge cluster randomized controlled trial

Background: Pancreatic cancer has a very poor prognosis. Best practices for the use of chemotherapy, enzyme replacement therapy, and biliary drainage have been identified but their implementation in daily clinical practice is often suboptimal. We hypothesized that a nationwide program to enhance implementation of these best practices in pancreatic cancer care would improve survival and quality of life. Methods/design: PACAP-1 is a nationwide multicenter stepped-wedge cluster randomized controlled superiority trial. In a per-center stepwise and randomized manner, best practices in pancreatic cancer care regarding the use of (neo)adjuvant and palliative chemotherapy, pancreatic enzyme replacement therapy, and metal biliary stents are implemented in all 17 Dutch pancreatic centers and their regional referral networks during a 6-week initiation period. Per pancreatic center, one multidisciplinary team functions as reference for the other centers in the network. Key best practices were identified from the literature, 3 years of data from existing nationwide registries within the Dutch Pancreatic Cancer Project (PACAP), and national expert meetings. The best practices follow the Dutch guideline on pancreatic cancer and the current state of the literature, and can be executed within daily clinical practice. The implementation process includes monitoring, return visits, and provider feedback in combination with education and reminders. Patient outcomes and compliance are monitored within the PACAP registries. Primary outcome is 1-year overall survival (for all disease stages). Secondary outcomes include quality of life, 3- and 5-year overall survival, and guideline compliance. An improvement of 10% in 1-year overall survival is considered clinically relevant. A 25-month study duration was chosen, which provides 80% statistical power for a mortality reduction of 10.0% in the 17 pancreatic cancer centers, with a required sample size of 2142 patients, corresponding to a 6.6% mortality reduction and 4769 patients nationwide. Discussion: The PACAP-1 trial is designed to evaluate whether a nationwide program for enhanced implementation of best practices in pancreatic cancer care can improve 1-year overall survival and quality of life. Trial registration: ClinicalTrials.gov, NCT03513705. Trial opened for accrual on 22th May 2018

Long-term yield of pancreatic cancer surveillance in high-risk individuals

Objective We aimed to determine the long-term yield of pancreatic cancer surveillance in hereditary predisposed high-risk individuals. Design From 2006 to 2019, we prospectively enrolled asymptomatic individuals with an estimated 10% or greater lifetime risk of pancreatic ductal adenocarcinoma (PDAC) after obligatory evaluation by a clinical geneticist and genetic testing, and subjected them to annual surveillance with both endoscopic ultrasonography (EUS) and MRI/cholangiopancreatography (MRI/MRCP) at each visit. Results 366 individuals (201 mutation-negative familial pancreatic cancer (FPC) kindreds and 165 PDAC susceptibility gene mutation carriers; mean age 54 years, SD 9.9) were followed for 63 months on average (SD 43.2). Ten individuals developed PDAC, of which four presented with a symptomatic interval carcinoma and six underwent resection. The cumulative PDAC incidence was 9.3% in the mutation carriers and 0% in the FPC kindreds (p<0.001). Median PDAC survival was 18 months (range 1-32). Surgery was performed in 17 individuals (4.6%), whose pathology revealed 6 PDACs (3 T1N0M0), 7 low-grade precursor lesions, 2 neuroendocrine tumours <2 cm, 1 autoimmune pancreatitis and in 1 individual no abnormality. There was no surgery-related mortality. EUS detected more solid lesions than MRI/MRCP (100% vs 22%, p<0.001), but less cystic lesions (42% vs 83%, p<0.001). Conclusion The diagnostic yield of PDAC was substantial in established high-risk mutation carriers, but non-existent in the mutation-negative proven FPC kindreds. Nevertheless, timely identification of resectable lesions proved challenging despite the concurrent use of two imaging modalities, with EUS outperforming MRI/MRCP. Overall, surveillance by imaging yields suboptimal results with a clear need for more sensitive diagnostic markers, including biomarkers

Impact of nationwide enhanced implementation of best practices in pancreatic cancer care (PACAP-1): A multicenter stepped-wedge cluster randomized controlled trial

Background: Pancreatic cancer has a very poor prognosis. Best practices for the use of chemotherapy, enzyme replacement therapy, and biliary drainage have been identified but their implementation in daily clinical practice is often suboptimal. We hypothesized that a nationwide program to enhance implementation of these best practices in pancreatic cancer care would improve survival and quality of life. Methods/design: PACAP-1 is a nationwide multicenter stepped-wedge cluster randomized controlled superiority trial. In a per-center stepwise and randomized manner, best practices in pancreatic cancer care regarding the use of (neo)adjuvant and palliative chemotherapy, pancreatic enzyme replacement therapy, and metal biliary stents are implemented in all 17 Dutch pancreatic centers and their regional referral networks during a 6-week initiation period. Per pancreatic center, one multidisciplinary team functions as reference for the other centers in the network. Key best practices were identified from the literature, 3 years of data from existing nationwide registries within the Dutch Pancreatic Cancer Project (PACAP), and national expert meetings. The best practices follow the Dutch guideline on pancreatic cancer and the current state of the literature, and can be executed within daily clinical practice. The implementation process includes monitoring, return visits, and provider feedback in combination with education and reminders. Patient outcomes and compliance are monitored within the PACAP registries. Primary outcome is 1-year overall survival (for all disease stages). Secondary outcomes include quality of life, 3- and 5-year overall survival, and guideline compliance. An improvement of 10% in 1-year overall survival is considered clinically relevant. A 25-month study duration was chosen, which provides 80% statistical power for a mortality reduction of 10.0% in the 17 pancreatic cancer centers, with a required sample size of 2142 patients, corresponding to a 6.6% mortality reduction and 4769 patients nationwide. Discussion: The PACAP-1 trial is designed to evaluate whether a nationwide program for enhanced implementation of best practices in pancreatic cancer care can improve 1-year overall survival and quality of life. Trial registration: ClinicalTrials.gov, NCT03513705. Trial opened for accrual on 22th May 2018

Characterization of metals for Cochlear Implants

The need for Cochlear Implants (CI's) with improved functionality and quality requires new techniques to be used to manufacture the electrode array. Titanium nitride (TiN) is one of the contenders for use as metal in the future CI's, but its characteristics need to be verified, measured and tested. A metal should comply to certain requirements like the ability to deliver enough charge to the nerve ending in the saline environment of the cochlea. TiN is able to withstand a high current density (2.8 mA µm2 ), while aluminium failed due to electromigration; even when coated with TiN. The resistance of a 10mm long and 5µm wide track decreases from 1.08 . 10^4? to 6.9. 10^2? when a combination of Al and TiN is made. This solves the reasonably high resistance of TiN. The self-heating and the change in resistance due to temperature changes (TCR) are measured, because the amount of dissipated heat should stay as low as possible. TiN has a low TCR, 5.9 . 10^-4. Furthermore, the metal must not dissolve in the environment, which can be checked by a (cyclic) voltammetry and by endurance tests. TiN was able to withstand the harsh tests. The improved functionality and quality asks for the addition of transistors to the electrode array. Furthermore, this thesis shows that it is possible to create working npn, NMOS and PMOS transistors with TiN using only 5 masks.Electronic InstrumentationMicroelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc

Evaluating Risk Management Strategies for Third Party Payment Networks

Like most consumers, you probably take the payment process when checking out at your favorite webshop, for granted. Regardless of which payment method you select, chances are big that the schemes of one of the few players within the payment industry - i.e. MasterCard or Visa - are used. We refer to this part of the industry as the card network. In order to create more competition for the card network, the European Commission is working on Payment Service Directive II (PSDII) which introduces the third party payment (TPP) network. Although there seems to be quite some potential for the TPP network, challenges are present. The new TPP network is less mature than the established card network that has dominated the payment industry for decades. Whereas one of the main challenges in the card network is the cost effective management of chargebacks, a similar challenge is present in the TPP network. Practice has shown that merchants that make use of payment methods in the TPP network are confronted with reversed payments - i.e. the TPP has provided an authorization, however no settlement has been received. We refer to these transactions as non-payments. There is a lack of knowledge about the reasons of the occurrence of the non-payments. In our research we have aimed to understand how big the financial risk of the occurrence of non-payments is and what could be strategies a payment service provider (PSP) can use to manage this risk. With our research, we have made four contributions. First, we described the payment process as it is organized in the TPP network and contrasted it with the card network. Second, we identified patterns in transaction data from the TPP network, that let us distinguish payments from non-payments. Third, we designed and evaluated risk management strategies that can be used to manage the non-payment risk. And fourth, we compared the merchant's transaction costs in the card and TPP networks to verify if the TPP network can become a cost competitor of the card network. The results of our research show that the TPP network is a cost competitor of the card network when considering the merchant's transaction costs.Economics of CybersecurityTechnology, Policy and Managemen