Disease management for chronic skin cancer

Worldwide non-melanoma skin cancer (NMSC) is a rapidly rising problem. In this thesis we show that an enormous gap exists between the official first primary figures available at cancer registries and the actual burden in a dermatology practice. NMSC needs to be regarded as a chronic disease and should be managed with help of a disease management system, as we describe in this thesis. A disease management system that organises health care for one well-documented health care problem uses a systematic approach. This includes prevention, education, multidisciplinary care, information technology, and management. We performed studies on innovations in the treatment and treatment processes of chronic skin cancer patients. Treatments that can be performed by the patients themselves, outside the hospital will reduce the workload at the clinic. The use of imiquimod 5% cream as a pre-treatment of Mohs’ micrographic surgery resulted in a more effective and efficient treatment. We demonstrated a more efficient treatment process with help of a one-stop-shop treatment for basal cell carcinomas. This resulted in a high patient satisfaction as well. Finally, we created a NMSC detection model and showed that dermatology nurses can contribute in diagnosing NMSC

New electron source concept for single-shot sub-100 fs electron diffraction in the 100 keV range

We present a method for producing sub-100 fs electron bunches that are suitable for single-shot ultrafast electron diffraction experiments in the 100 keV energy range. A combination of analytical results and state-of-the-art numerical simulations show that it is possible to create 100 keV, 0.1 pC, 20 fs electron bunches with a spotsize smaller than 500 micron and a transverse coherence length of 3 nm, using established technologies in a table-top set-up. The system operates in the space-charge dominated regime to produce energy-correlated bunches that are recompressed by established radio-frequency techniques. With this approach we overcome the Coulomb expansion of the bunch, providing an entirely new ultrafast electron diffraction source concept

Detecting multivariate interactions in spatial point patterns with Gibbs models and variable selection

We propose a method for detecting significant interactions in very large multivariate spatial point patterns. This methodology develops high dimensional data understanding in the point process setting. The method is based on modelling the patterns using a flexible Gibbs point process model to directly characterise point-to-point interactions at different spatial scales. By using the Gibbs framework significant interactions can also be captured at small scales. Subsequently, the Gibbs point process is fitted using a pseudo-likelihood approximation, and we select significant interactions automatically using the group lasso penalty with this likelihood approximation. Thus we estimate the multivariate interactions stably even in this setting. We demonstrate the feasibility of the method with a simulation study and show its power by applying it to a large and complex rainforest plant population data set of 83 species

Compression of sub-relativistic space-charge-dominated electron bunches for single-shot femtosecond electron diffraction

We demonstrate compression of 95 keV, space-charge-dominated electron bunches to sub-100 fs durations. These bunches have sufficient charge (200 fC) and are of sufficient quality to capture a diffraction pattern with a single shot, which we demonstrate by a diffraction experiment on a polycrystalline gold foil. Compression is realized by means of velocity bunching as a result of a velocity chirp, induced by the oscillatory longitudinal electric field of a 3 GHz radio-frequency cavity. The arrival time jitter is measured to be 80 fs