Spectral diffusion of single semiconductor nanocrystals: the influence of the dielectric environment

We have explored the influence of different matrices on the emission line shape of individual homogeneously coated CdSe/CdS/ZnS nanocrystals. The results obtained corroborate previous observations of a correlation between blinking events and spectral diffusion but in addition we have found that the extent of spectral diffusion is almost independent of the dielectric environment of the NC. Additionally, we report the observation of a correlation between the line width and emission energy which is not expected to occur in the spherical - symmetric NCs employed in this work. The implications of these results are discussed.Comment: 3 pages, 3 figure

Facts and fiction in hip fracture treatment

As the number of hip fracture patients has increased dramatically over the years, the need for high quality, multidisciplinary and patient centred fracture treatment continues to grow. The first aim of this thesis is to provide better understanding of fracture patterns and classification in hip fractures. Secondly, we investigated what fracture, patient or surgeons' characteristics may lead to improvement of hip fracture care? In Chapters 2 to 6 increased insight in the fracture anatomy was intended and the reliability of the most frequently used classifications for proximal femur fractures were studied. Rotational instability appears to play a significant role in fixation failure. In Chapter 7 the amount of rotational instability in hip fractures, related to type of fracture and modern implants was studied with the use of radiostereometric analysis (RSA). Chapter 8 presents the results of a retrospective cohort study concerning the pre- and post-operative radiographic fracture characteristics in relation to patient age and the occurrence of reoperation. The surgeons' intra-operative estimations of the femoral anteversion angle during placement of a hemi-arthroplasty for femoral neck fractures was studied in Chapter 9 and in Chapter 10 a systematic review regarding the treatment dilemmas in non-displaced femoral neck fracture is described.Grants: Part of thesis was funded by a grant of the Anna Fonds|NOREF. Printing of this thesis has been financially supported by: Nederlandse Vereniging voor Traumachirurgie, Raad van Bestuur Medisch Centrum Haaglanden-Bronovo, Stiching Extra-Curriculaire Activiteiten Haagse Chirurgen, Traumacentrum West, ChipSoftUBL - phd migration 201

Mycobacterium canettii, the smooth variant of M. tuberculosis, isolated from a Swiss patient exposed in Africa.

An exceptionally smooth and glossy morphotype of Mycobacterium tuberculosis complex was isolated from a 56-year-old Swiss patient with mesenteric tuberculosis. Direct 16S rRNA sequence analysis of the hypervariable signature gene regions revealed a 100% homology to the specific M. tuberculosis complex sequence. Spoligotyping and restriction fragment length polymorphism analyses using the insertion sequences IS6110 and IS1081 and the polymorphic GC-rich sequence as additional genetic markers identified the isolate as the novel taxon M. canettii. Like a Somali child with a similar case, this patient probably contracted the infection in Africa, which raises questions about the geographic distribution of M. canettii

Redoxpotentiaal en residente darmflora van de muis

In dit proefschrift wordt, in hoofdstuk I, een overzicht gegeven van de milieukenmerken die de samenstelling van de residente darmflora bepalen, Vanuit ecologisch standpunt gezien is de redoxpotentiaal één van de belangrijkste van deze factoren. De lage redoxpotentiaal in het coecum van conventionele dieren is ervoor verantwoordelijk dat de residente flora uit facultatief anaerobe en strikt anaerobe micro-organismen bestaat. De darmflora zelf houdt de redoxpotentiaal op een laag niveau, hetgeen blijkt uit het feit dat de potentiaal in het coecum van kiemvrije muizen ongeveer 200 mV hoger is dan in het coecum van conventionele dieren. In hoeverre de hoge redoxpotentiaal in het coecum van kiemvrije muizen bepalend is voor het al dan niet koloniseren van strikt anaerobe darmbacteriën en hoe de redoxpotentiaal verandert onder invloed van de nesteling van deze micro-organismen wordt in dit onderzoek bestudeer

Likelihood-Based Inference for Discretely Observed Birth-Death-Shift Processes, with Applications to Evolution of Mobile Genetic Elements

Continuous-time birth-death-shift (BDS) processes are frequently used in stochastic modeling, with many applications in ecology and epidemiology. In particular, such processes can model evolutionary dynamics of transposable elements - important genetic markers in molecular epidemiology. Estimation of the effects of individual covariates on the birth, death, and shift rates of the process can be accomplished by analyzing patient data, but inferring these rates in a discretely and unevenly observed setting presents computational challenges. We propose a mutli-type branching process approximation to BDS processes and develop a corresponding expectation maximization (EM) algorithm, where we use spectral techniques to reduce calculation of expected sufficient statistics to low dimensional integration. These techniques yield an efficient and robust optimization routine for inferring the rates of the BDS process, and apply more broadly to multi-type branching processes where rates can depend on many covariates. After rigorously testing our methodology in simulation studies, we apply our method to study intrapatient time evolution of IS6110 transposable element, a frequently used element during estimation of epidemiological clusters of Mycobacterium tuberculosis infections.Comment: 31 pages, 7 figures, 1 tabl